xref: /linux/arch/x86/Kconfig (revision 7ecd19cfdfcbb625cc059dfa5b267d2436732c1c)
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
196503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	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
242*7ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
243cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
244d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
245c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
246e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2471e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2486ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
249d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2506471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2516471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2527c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2537ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25405736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
255c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
256*7ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
257*7ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
25886596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2592eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
260625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2616471b825SIngo Molnar	select PERF_EVENTS
2623195ef59SPrarit Bhargava	select RTC_LIB
263d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2646471b825SIngo Molnar	select SPARSE_IRQ
26583fe27eaSPranith Kumar	select SRCU
2661e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2676471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26815f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2694aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2706471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2716471b825SIngo Molnar	select VIRT_TO_BUS
2723b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2736471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2740c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2759e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2767d8330a5SBalbir Singh
277ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2783120e25eSJan Beulich	def_bool y
2793120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
280ba7e4d13SIngo Molnar
28151b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
28251b26adaSLinus Torvalds	string
28351b26adaSLinus Torvalds	default "elf32-i386" if X86_32
28451b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
28551b26adaSLinus Torvalds
2868d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2873c2362e6SHarvey Harrison	def_bool y
2888d5fffb9SSam Ravnborg
2898d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2903c2362e6SHarvey Harrison	def_bool y
2918d5fffb9SSam Ravnborg
2928d5fffb9SSam Ravnborgconfig MMU
2933c2362e6SHarvey Harrison	def_bool y
2948d5fffb9SSam Ravnborg
2959e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2969e08f57dSDaniel Cashman	default 28 if 64BIT
2979e08f57dSDaniel Cashman	default 8
2989e08f57dSDaniel Cashman
2999e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3009e08f57dSDaniel Cashman	default 32 if 64BIT
3019e08f57dSDaniel Cashman	default 16
3029e08f57dSDaniel Cashman
3039e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3049e08f57dSDaniel Cashman	default 8
3059e08f57dSDaniel Cashman
3069e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3079e08f57dSDaniel Cashman	default 16
3089e08f57dSDaniel Cashman
3098d5fffb9SSam Ravnborgconfig SBUS
3108d5fffb9SSam Ravnborg	bool
3118d5fffb9SSam Ravnborg
3128d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3133120e25eSJan Beulich	def_bool y
3143120e25eSJan Beulich	depends on ISA_DMA_API
3158d5fffb9SSam Ravnborg
3168d5fffb9SSam Ravnborgconfig GENERIC_BUG
3173c2362e6SHarvey Harrison	def_bool y
3188d5fffb9SSam Ravnborg	depends on BUG
319b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
320b93a531eSJan Beulich
321b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
322b93a531eSJan Beulich	bool
3238d5fffb9SSam Ravnborg
3248d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3253120e25eSJan Beulich	def_bool y
3263120e25eSJan Beulich	depends on ISA_DMA_API
3278d5fffb9SSam Ravnborg
3281032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3291032c0baSSam Ravnborg	def_bool y
3301032c0baSSam Ravnborg
3319a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3329a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3338d5fffb9SSam Ravnborg
334316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
335316d097cSDave Hansen	def_bool y
336316d097cSDave Hansen
337801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
338801e4062SJohannes Berg	def_bool y
339801e4062SJohannes Berg
340d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
341d7109fe3SAndy Shevchenko	int
342d7109fe3SAndy Shevchenko	default 1024 if X86_64
343d7109fe3SAndy Shevchenko	default 512
344d7109fe3SAndy Shevchenko
345f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
346f4cb5700SJohannes Berg	def_bool y
347f4cb5700SJohannes Berg
34853313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
34953313b2cSSteve Capper	def_bool y
35053313b2cSSteve Capper
3518d5fffb9SSam Ravnborgconfig AUDIT_ARCH
352e0fd24a3SJan Beulich	def_bool y if X86_64
3538d5fffb9SSam Ravnborg
354d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
355d6f2d75aSAndrey Ryabinin	hex
356d6f2d75aSAndrey Ryabinin	depends on KASAN
357d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
358d6f2d75aSAndrey Ryabinin
35969575d38SShane Wangconfig HAVE_INTEL_TXT
36069575d38SShane Wang	def_bool y
3616ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36269575d38SShane Wang
3636b0c3d44SSam Ravnborgconfig X86_32_SMP
3646b0c3d44SSam Ravnborg	def_bool y
3656b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3666b0c3d44SSam Ravnborg
3676b0c3d44SSam Ravnborgconfig X86_64_SMP
3686b0c3d44SSam Ravnborg	def_bool y
3696b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3706b0c3d44SSam Ravnborg
3712b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3722b144498SSrikar Dronamraju	def_bool y
3732b144498SSrikar Dronamraju
374d20642f0SRob Herringconfig FIX_EARLYCON_MEM
375d20642f0SRob Herring	def_bool y
376d20642f0SRob Herring
37794d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
37894d49eb3SKirill A. Shutemov	bool
37994d49eb3SKirill A. Shutemov
38098233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38198233368SKirill A. Shutemov	int
38277ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38398233368SKirill A. Shutemov	default 4 if X86_64
38498233368SKirill A. Shutemov	default 3 if X86_PAE
38598233368SKirill A. Shutemov	default 2
38698233368SKirill A. Shutemov
3872a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3882a61f474SMasahiro Yamada	bool
3892a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3902a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3912a61f474SMasahiro Yamada	help
3922a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3933fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3943fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3952a61f474SMasahiro Yamada
396506f1d07SSam Ravnborgmenu "Processor type and features"
397506f1d07SSam Ravnborg
398506f1d07SSam Ravnborgconfig SMP
399506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
400a7f7f624SMasahiro Yamada	help
401506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4024a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4034a474157SRobert Graffham	  than one CPU, say Y.
404506f1d07SSam Ravnborg
4054a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
406506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
407506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4084a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
409506f1d07SSam Ravnborg	  will run faster if you say N here.
410506f1d07SSam Ravnborg
411506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
412506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
413506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
414506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
415506f1d07SSam Ravnborg
416506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
417506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
418506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
419506f1d07SSam Ravnborg
420cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4214f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
422506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
423506f1d07SSam Ravnborg
424506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
425506f1d07SSam Ravnborg
4269def39beSJosh Triplettconfig X86_FEATURE_NAMES
4279def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4289def39beSJosh Triplett	default y
429a7f7f624SMasahiro Yamada	help
4309def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4319def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4329def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4339def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4349def39beSJosh Triplett
4359def39beSJosh Triplett	  If in doubt, say Y.
4369def39beSJosh Triplett
43706cd9a7dSYinghai Luconfig X86_X2APIC
43806cd9a7dSYinghai Lu	bool "Support x2apic"
43919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
440a7f7f624SMasahiro Yamada	help
44106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44206cd9a7dSYinghai Lu
44306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44506cd9a7dSYinghai Lu
44606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44706cd9a7dSYinghai Lu
4486695c85bSYinghai Luconfig X86_MPPARSE
4494590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4507a527688SJan Beulich	default y
4515ab74722SIngo Molnar	depends on X86_LOCAL_APIC
452a7f7f624SMasahiro Yamada	help
4536695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4546695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4556695c85bSYinghai Lu
456ddd70cf9SJun Nakajimaconfig GOLDFISH
457ddd70cf9SJun Nakajima	def_bool y
458ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
459ddd70cf9SJun Nakajima
46076b04384SDavid Woodhouseconfig RETPOLINE
46176b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46276b04384SDavid Woodhouse	default y
46376b04384SDavid Woodhouse	help
46476b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46576b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46676b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46776b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46876b04384SDavid Woodhouse
469e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
470e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4716fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47259fe5a77SThomas Gleixner	select KERNFS
473e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47478e99b4aSFenghua Yu	help
475e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4766fe07ce3SBabu Moger
4776fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4786fe07ce3SBabu Moger	  usage by the CPU.
4796fe07ce3SBabu Moger
4806fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4816fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4826fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4836fe07ce3SBabu Moger
4846fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4856fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4866fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48778e99b4aSFenghua Yu
48878e99b4aSFenghua Yu	  Say N if unsure.
48978e99b4aSFenghua Yu
4908425091fSRavikiran G Thirumalaiif X86_32
491a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
492a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
493a0d0bb4dSRandy Dunlap	depends on SMP
494a7f7f624SMasahiro Yamada	help
495e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
496a0d0bb4dSRandy Dunlap
497c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
498c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
499c5c606d9SRavikiran G Thirumalai	default y
500a7f7f624SMasahiro Yamada	help
50106ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50206ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50306ac8346SIngo Molnar	  systems out there.)
50406ac8346SIngo Molnar
5058425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5068425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
507cb7b8023SBen Hutchings		Goldfish (Android emulator)
5088425091fSRavikiran G Thirumalai		AMD Elan
5098425091fSRavikiran G Thirumalai		RDC R-321x SoC
5108425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51183125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5123f4110a4SThomas Gleixner		Moorestown MID devices
51306ac8346SIngo Molnar
51406ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51506ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5168425091fSRavikiran G Thirumalaiendif
51706ac8346SIngo Molnar
5188425091fSRavikiran G Thirumalaiif X86_64
5198425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5208425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5218425091fSRavikiran G Thirumalai	default y
522a7f7f624SMasahiro Yamada	help
5238425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5248425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5258425091fSRavikiran G Thirumalai	  systems out there.)
5268425091fSRavikiran G Thirumalai
5278425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5288425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52944b111b5SSteffen Persvold		Numascale NumaChip
5308425091fSRavikiran G Thirumalai		ScaleMP vSMP
5318425091fSRavikiran G Thirumalai		SGI Ultraviolet
5328425091fSRavikiran G Thirumalai
5338425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5348425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5358425091fSRavikiran G Thirumalaiendif
536c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
537c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53844b111b5SSteffen Persvoldconfig X86_NUMACHIP
53944b111b5SSteffen Persvold	bool "Numascale NumaChip"
54044b111b5SSteffen Persvold	depends on X86_64
54144b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54244b111b5SSteffen Persvold	depends on NUMA
54344b111b5SSteffen Persvold	depends on SMP
54444b111b5SSteffen Persvold	depends on X86_X2APIC
545f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
546a7f7f624SMasahiro Yamada	help
54744b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54844b111b5SSteffen Persvold	  enable more than ~168 cores.
54944b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
55003b48632SNick Piggin
5516a48565eSIngo Molnarconfig X86_VSMP
552c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5536276a074SBorislav Petkov	select HYPERVISOR_GUEST
5546a48565eSIngo Molnar	select PARAVIRT
5556a48565eSIngo Molnar	depends on X86_64 && PCI
556c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
557ead91d4bSShai Fultheim	depends on SMP
558a7f7f624SMasahiro Yamada	help
5596a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5606a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5616a48565eSIngo Molnar	  if you have one of these machines.
5626a48565eSIngo Molnar
563c5c606d9SRavikiran G Thirumalaiconfig X86_UV
564c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
565c5c606d9SRavikiran G Thirumalai	depends on X86_64
566c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56754c28d29SJack Steiner	depends on NUMA
5681ecb4ae5SAndrew Morton	depends on EFI
569c2209ea5SIngo Molnar	depends on KEXEC_CORE
5709d6c26e7SSuresh Siddha	depends on X86_X2APIC
5711222e564SIngo Molnar	depends on PCI
572a7f7f624SMasahiro Yamada	help
573c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
574c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
575c5c606d9SRavikiran G Thirumalai
576c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
577c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
578506f1d07SSam Ravnborg
579ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
580ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
581cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
582a7f7f624SMasahiro Yamada	help
583ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
584ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
585ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
586ddd70cf9SJun Nakajima
587c751e17bSThomas Gleixnerconfig X86_INTEL_CE
588c751e17bSThomas Gleixner	bool "CE4100 TV platform"
589c751e17bSThomas Gleixner	depends on PCI
590c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5916084a6e2SJiang Liu	depends on X86_IO_APIC
592c751e17bSThomas Gleixner	depends on X86_32
593c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59437bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
595da6b737bSSebastian Andrzej Siewior	select OF
596da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
597a7f7f624SMasahiro Yamada	help
598c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
599c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
600c751e17bSThomas Gleixner	  boxes and media devices.
601c751e17bSThomas Gleixner
6024cb9b00fSDavid Cohenconfig X86_INTEL_MID
60343605ef1SAlan Cox	bool "Intel MID platform support"
60443605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
605edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6061ea7c673SAlan Cox	depends on PCI
6073fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6081ea7c673SAlan Cox	depends on X86_IO_APIC
6094cb9b00fSDavid Cohen	select I2C
6107c9c3a1eSAlan Cox	select DW_APB_TIMER
61154b34aa0SMika Westerberg	select INTEL_SCU_PCI
612a7f7f624SMasahiro Yamada	help
6134cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6144cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6154cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6161ea7c673SAlan Cox
6174cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6184cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
61943605ef1SAlan Cox
6208bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6218bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6228bbc2a13SBryan O'Donoghue	depends on X86_32
6238bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6248bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6258bbc2a13SBryan O'Donoghue	depends on X86_TSC
6268bbc2a13SBryan O'Donoghue	depends on PCI
6278bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6288bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6298bbc2a13SBryan O'Donoghue	select IOSF_MBI
6308bbc2a13SBryan O'Donoghue	select INTEL_IMR
6319ab6eb51SAndy Shevchenko	select COMMON_CLK
632a7f7f624SMasahiro Yamada	help
6338bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6348bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6358bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6368bbc2a13SBryan O'Donoghue
6373d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6383d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6395962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6403d48aab1SMika Westerberg	select COMMON_CLK
6410f531431SMathias Nyman	select PINCTRL
642eebb3e8dSAndy Shevchenko	select IOSF_MBI
643a7f7f624SMasahiro Yamada	help
6443d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6453d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6460f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6470f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6483d48aab1SMika Westerberg
64992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65192082a88SKen Xue	depends on ACPI
65292082a88SKen Xue	select COMMON_CLK
65392082a88SKen Xue	select PINCTRL
654a7f7f624SMasahiro Yamada	help
65592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65892082a88SKen Xue	  implemented under PINCTRL subsystem.
65992082a88SKen Xue
660ced3ce76SDavid E. Boxconfig IOSF_MBI
661ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
662ced3ce76SDavid E. Box	depends on PCI
663a7f7f624SMasahiro Yamada	help
664ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
665ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
666ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
667ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
668ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
669ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
670ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
671ced3ce76SDavid E. Box	   - BayTrail
672ced3ce76SDavid E. Box	   - Braswell
673ced3ce76SDavid E. Box	   - Quark
674ced3ce76SDavid E. Box
675ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
676ced3ce76SDavid E. Box
677ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
678ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
679ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
680a7f7f624SMasahiro Yamada	help
681ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
682ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
683ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
684ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
685ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
686ed2226bdSDavid E. Box	  device they want to access.
687ed2226bdSDavid E. Box
688ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
689ed2226bdSDavid E. Box
690c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
691c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
692506f1d07SSam Ravnborg	depends on X86_32
693c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
694c5c606d9SRavikiran G Thirumalai	select M486
695c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
696a7f7f624SMasahiro Yamada	help
697c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
698c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
699c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
700c5c606d9SRavikiran G Thirumalai
701e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7029c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7039c398017SIngo Molnar	depends on X86_32 && SMP
704c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
705a7f7f624SMasahiro Yamada	help
706b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
707b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
708b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
709b5660ba7SH. Peter Anvin	  one and will fallback to default.
710d49c4288SYinghai Lu
711c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
712d49c4288SYinghai Lu
713d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7146fc108a0SJan Beulich	def_bool y
715d949f36fSLinus Torvalds	# MCE code calls memory_failure():
716d949f36fSLinus Torvalds	depends on X86_MCE
717d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
718d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
719d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
720d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
721d949f36fSLinus Torvalds
72283125a3aSAlessandro Rubiniconfig STA2X11
72383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72583125a3aSAlessandro Rubini	select SWIOTLB
72683125a3aSAlessandro Rubini	select MFD_STA2X11
7270145071bSLinus Walleij	select GPIOLIB
728a7f7f624SMasahiro Yamada	help
72983125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73083125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73183125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73283125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73383125a3aSAlessandro Rubini	  standard PC machines.
73483125a3aSAlessandro Rubini
73582148d1dSShérabconfig X86_32_IRIS
73682148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73782148d1dSShérab	depends on X86_32
738a7f7f624SMasahiro Yamada	help
73982148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74082148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74182148d1dSShérab	  needed to do so, which is what this module does at
74282148d1dSShérab	  kernel shutdown.
74382148d1dSShérab
74482148d1dSShérab	  This is only for Iris machines from EuroBraille.
74582148d1dSShérab
74682148d1dSShérab	  If unused, say N.
74782148d1dSShérab
748ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7493c2362e6SHarvey Harrison	def_bool y
7503c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
751a87d0914SKen Chen	depends on X86
752a7f7f624SMasahiro Yamada	help
753506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
754506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
755506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
756506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
757506f1d07SSam Ravnborg
758506f1d07SSam Ravnborg	  If in doubt, say "Y".
759506f1d07SSam Ravnborg
7606276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7616276a074SBorislav Petkov	bool "Linux guest support"
762a7f7f624SMasahiro Yamada	help
7636276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7646276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7656276a074SBorislav Petkov	  setup.
766506f1d07SSam Ravnborg
7676276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7686276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
769506f1d07SSam Ravnborg
7706276a074SBorislav Petkovif HYPERVISOR_GUEST
771506f1d07SSam Ravnborg
772e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
773e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
774a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
775a7f7f624SMasahiro Yamada	help
776e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
777e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
778e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
779e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
780e61bd94aSEduardo Pereira Habkost
781c00a280aSJuergen Grossconfig PARAVIRT_XXL
782c00a280aSJuergen Gross	bool
783c00a280aSJuergen Gross
7846276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7856276a074SBorislav Petkov	bool "paravirt-ops debugging"
7866276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
787a7f7f624SMasahiro Yamada	help
7886276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7896276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7906276a074SBorislav Petkov
791b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
792b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7936ea30386SKees Cook	depends on PARAVIRT && SMP
794a7f7f624SMasahiro Yamada	help
795b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
796b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
797b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
798b4ecc126SJeremy Fitzhardinge
7994c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8004c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
801b4ecc126SJeremy Fitzhardinge
8024c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
803b4ecc126SJeremy Fitzhardinge
804ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
805ecca2502SZhao Yakui	def_bool n
806ecca2502SZhao Yakui
8076276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8086276a074SBorislav Petkov
8096276a074SBorislav Petkovconfig KVM_GUEST
8106276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8116276a074SBorislav Petkov	depends on PARAVIRT
8126276a074SBorislav Petkov	select PARAVIRT_CLOCK
813a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
814b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8156276a074SBorislav Petkov	default y
816a7f7f624SMasahiro Yamada	help
8176276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8186276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8196276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8206276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8216276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8226276a074SBorislav Petkov
823a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
824a1c4423bSMarcelo Tosatti	def_bool n
825a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
826a1c4423bSMarcelo Tosatti	help
827a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
828a1c4423bSMarcelo Tosatti
8297733607fSMaran Wilsonconfig PVH
8307733607fSMaran Wilson	bool "Support for running PVH guests"
831a7f7f624SMasahiro Yamada	help
8327733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8337733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8347733607fSMaran Wilson
8356276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8366276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8376276a074SBorislav Petkov	depends on PARAVIRT
838a7f7f624SMasahiro Yamada	help
8396276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8406276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8416276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8426276a074SBorislav Petkov	  that, there can be a small performance impact.
8436276a074SBorislav Petkov
8446276a074SBorislav Petkov	  If in doubt, say N here.
8456276a074SBorislav Petkov
8467af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8477af192c9SGerd Hoffmann	bool
8487af192c9SGerd Hoffmann
8494a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8504a362601SJan Kiszka	bool "Jailhouse non-root cell support"
851abde587bSArnd Bergmann	depends on X86_64 && PCI
85287e65d05SJan Kiszka	select X86_PM_TIMER
853a7f7f624SMasahiro Yamada	help
8544a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8554a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8564a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8574a362601SJan Kiszka
858ec7972c9SZhao Yakuiconfig ACRN_GUEST
859ec7972c9SZhao Yakui	bool "ACRN Guest support"
860ec7972c9SZhao Yakui	depends on X86_64
861498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
862ec7972c9SZhao Yakui	help
863ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
864ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
865ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
866ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
867ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
868ec7972c9SZhao Yakui
8696276a074SBorislav Petkovendif #HYPERVISOR_GUEST
87097349135SJeremy Fitzhardinge
871506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
872506f1d07SSam Ravnborg
873506f1d07SSam Ravnborgconfig HPET_TIMER
8743c2362e6SHarvey Harrison	def_bool X86_64
875506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
876a7f7f624SMasahiro Yamada	help
877506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
878506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
879506f1d07SSam Ravnborg	  present.
880506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
881506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
882506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8834e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8844e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
885506f1d07SSam Ravnborg
886506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
887506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
888506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
889506f1d07SSam Ravnborg
890506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
891506f1d07SSam Ravnborg
892506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8933c2362e6SHarvey Harrison	def_bool y
8943228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
895506f1d07SSam Ravnborg
8966a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
897506f1d07SSam Ravnborg# The code disables itself when not needed.
8987ae9392cSThomas Petazzoniconfig DMI
8997ae9392cSThomas Petazzoni	default y
900cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9016a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
902a7f7f624SMasahiro Yamada	help
9037ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9047ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9057ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9067ae9392cSThomas Petazzoni	  BIOS code.
9077ae9392cSThomas Petazzoni
908506f1d07SSam Ravnborgconfig GART_IOMMU
90938901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9102f9237d4SChristoph Hellwig	select DMA_OPS
911a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
912506f1d07SSam Ravnborg	select SWIOTLB
91323ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
914a7f7f624SMasahiro Yamada	help
915ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
916ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
917ced3c42cSIngo Molnar
918ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
919ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
920ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
921ced3c42cSIngo Molnar
922ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
923ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
924ced3c42cSIngo Molnar
925ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
926ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
927ced3c42cSIngo Molnar	  32-bit limited device.
928ced3c42cSIngo Molnar
929ced3c42cSIngo Molnar	  If unsure, say Y.
930506f1d07SSam Ravnborg
9311184dc2fSMike Travisconfig MAXSMP
932ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9336ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93436f5101aSMike Travis	select CPUMASK_OFFSTACK
935a7f7f624SMasahiro Yamada	help
936ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9371184dc2fSMike Travis	  If unsure, say N.
938506f1d07SSam Ravnborg
939aec6487eSIngo Molnar#
940aec6487eSIngo Molnar# The maximum number of CPUs supported:
941aec6487eSIngo Molnar#
942aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
943aec6487eSIngo Molnar# and which can be configured interactively in the
944aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
945aec6487eSIngo Molnar#
946aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
947aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
948aec6487eSIngo Molnar#
949aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
950aec6487eSIngo Molnar#   interactive configuration. )
951aec6487eSIngo Molnar#
952a0d0bb4dSRandy Dunlap
953aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
954a0d0bb4dSRandy Dunlap	int
955aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
956a0d0bb4dSRandy Dunlap	default    1 if !SMP
957a0d0bb4dSRandy Dunlap	default    2
958a0d0bb4dSRandy Dunlap
959aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
960a0d0bb4dSRandy Dunlap	int
961a0d0bb4dSRandy Dunlap	depends on X86_32
962aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
963aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
964a0d0bb4dSRandy Dunlap	default    1 if !SMP
965a0d0bb4dSRandy Dunlap
966aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
967a0d0bb4dSRandy Dunlap	int
968a0d0bb4dSRandy Dunlap	depends on X86_64
9691edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9701edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
971a0d0bb4dSRandy Dunlap	default    1 if !SMP
972aec6487eSIngo Molnar
973aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
974aec6487eSIngo Molnar	int
975aec6487eSIngo Molnar	depends on X86_32
976aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
977aec6487eSIngo Molnar	default    8 if  SMP
978aec6487eSIngo Molnar	default    1 if !SMP
979aec6487eSIngo Molnar
980aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
981aec6487eSIngo Molnar	int
982aec6487eSIngo Molnar	depends on X86_64
983a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
984a0d0bb4dSRandy Dunlap	default   64 if  SMP
985aec6487eSIngo Molnar	default    1 if !SMP
986a0d0bb4dSRandy Dunlap
987506f1d07SSam Ravnborgconfig NR_CPUS
98836f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
989aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
990aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
991a7f7f624SMasahiro Yamada	help
992506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
993bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
994cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
995506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
996506f1d07SSam Ravnborg
997aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
998aec6487eSIngo Molnar	  to the kernel image.
999506f1d07SSam Ravnborg
100066558b73STim Chenconfig SCHED_CLUSTER
100166558b73STim Chen	bool "Cluster scheduler support"
100266558b73STim Chen	depends on SMP
100366558b73STim Chen	default y
100466558b73STim Chen	help
100566558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
100666558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
100766558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
100866558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
100966558b73STim Chen	  busses.
101066558b73STim Chen
1011506f1d07SSam Ravnborgconfig SCHED_SMT
1012dbe73364SThomas Gleixner	def_bool y if SMP
1013506f1d07SSam Ravnborg
1014506f1d07SSam Ravnborgconfig SCHED_MC
10153c2362e6SHarvey Harrison	def_bool y
10163c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1017c8e56d20SBorislav Petkov	depends on SMP
1018a7f7f624SMasahiro Yamada	help
1019506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1020506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1021506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1022506f1d07SSam Ravnborg
1023de966cf4STim Chenconfig SCHED_MC_PRIO
1024de966cf4STim Chen	bool "CPU core priorities scheduler support"
10250a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10260a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10270a21fc12SIngo Molnar	select CPU_FREQ
1028de966cf4STim Chen	default y
1029a7f7f624SMasahiro Yamada	help
1030de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1031de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1032de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1033de966cf4STim Chen	  single threaded workloads) than others.
1034de966cf4STim Chen
1035de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1036de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1037de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1038de966cf4STim Chen	  overall system performance can be achieved.
1039de966cf4STim Chen
1040de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1041de966cf4STim Chen
1042de966cf4STim Chen	  If unsure say Y here.
10435e76b2abSTim Chen
104430b8b006SThomas Gleixnerconfig UP_LATE_INIT
104530b8b006SThomas Gleixner	def_bool y
1046ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104730b8b006SThomas Gleixner
1048506f1d07SSam Ravnborgconfig X86_UP_APIC
104950849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
105050849eefSJan Beulich	default PCI_MSI
105138a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1052a7f7f624SMasahiro Yamada	help
1053506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1054506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1055506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1056506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1057506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1058506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1059506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1060506f1d07SSam Ravnborg	  lockups.
1061506f1d07SSam Ravnborg
1062506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1063506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1064506f1d07SSam Ravnborg	depends on X86_UP_APIC
1065a7f7f624SMasahiro Yamada	help
1066506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1067506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1068506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1069506f1d07SSam Ravnborg
1070506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1071506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1072506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10753c2362e6SHarvey Harrison	def_bool y
10760dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1077b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107852f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1079506f1d07SSam Ravnborg
1080506f1d07SSam Ravnborgconfig X86_IO_APIC
1081b1da1e71SJan Beulich	def_bool y
1082b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1083506f1d07SSam Ravnborg
108441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
108541b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108641b9eb26SStefan Assmann	depends on X86_IO_APIC
1087a7f7f624SMasahiro Yamada	help
108841b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108941b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
109041b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
109141b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
109241b9eb26SStefan Assmann
109341b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
109441b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
109541b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109641b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109741b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109841b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109941b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
110041b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
110141b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
110241b9eb26SStefan Assmann	  down (vital) interrupt lines.
110341b9eb26SStefan Assmann
110441b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
110541b9eb26SStefan Assmann	  increased on these systems.
110641b9eb26SStefan Assmann
1107506f1d07SSam Ravnborgconfig X86_MCE
1108bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1109648ed940SChen, Gong	select GENERIC_ALLOCATOR
1110e57dbaf7SBorislav Petkov	default y
1111a7f7f624SMasahiro Yamada	help
1112bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1113bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1114506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1115bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11164efc0670SAndi Kleen
11175de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11185de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11195de97c9fSTony Luck	depends on X86_MCE
1120a7f7f624SMasahiro Yamada	help
11215de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11225de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11235de97c9fSTony Luck	  rasdaemon solution.
11245de97c9fSTony Luck
1125506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11263c2362e6SHarvey Harrison	def_bool y
11273c2362e6SHarvey Harrison	prompt "Intel MCE features"
1128c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1129a7f7f624SMasahiro Yamada	help
1130506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1131506f1d07SSam Ravnborg	   the thermal monitor.
1132506f1d07SSam Ravnborg
1133506f1d07SSam Ravnborgconfig X86_MCE_AMD
11343c2362e6SHarvey Harrison	def_bool y
11353c2362e6SHarvey Harrison	prompt "AMD MCE features"
1136f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1137a7f7f624SMasahiro Yamada	help
1138506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1139506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1140506f1d07SSam Ravnborg
11414efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11426fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1143c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1144a7f7f624SMasahiro Yamada	help
11454efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11465065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11474efc0670SAndi Kleen	  line.
11484efc0670SAndi Kleen
1149b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1150b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11516fc108a0SJan Beulich	def_bool y
1152b2762686SAndi Kleen
1153ea149b36SAndi Kleenconfig X86_MCE_INJECT
1154bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1155ea149b36SAndi Kleen	tristate "Machine check injector support"
1156a7f7f624SMasahiro Yamada	help
1157ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1158ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1159ea149b36SAndi Kleen	  QA it is safe to say n.
1160ea149b36SAndi Kleen
116107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1162e633c65aSKan Liang
11635aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11641e642812SIngo Molnar	bool "Legacy VM86 support"
1165506f1d07SSam Ravnborg	depends on X86_32
1166a7f7f624SMasahiro Yamada	help
11675aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11685aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11695aef51c3SAndy Lutomirski
11705aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11715aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11725aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11735aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11745aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11751e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11761e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11771e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11781e642812SIngo Molnar	  enable this option.
11795aef51c3SAndy Lutomirski
11801e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11811e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11821e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11831e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11845aef51c3SAndy Lutomirski
11851e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11861e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11875aef51c3SAndy Lutomirski
11881e642812SIngo Molnar	  If unsure, say N here.
11895aef51c3SAndy Lutomirski
11905aef51c3SAndy Lutomirskiconfig VM86
11915aef51c3SAndy Lutomirski	bool
11925aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
119334273f41SH. Peter Anvin
119434273f41SH. Peter Anvinconfig X86_16BIT
119534273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119634273f41SH. Peter Anvin	default y
1197a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1198a7f7f624SMasahiro Yamada	help
119934273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
120034273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
120134273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
120234273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
120334273f41SH. Peter Anvin
120434273f41SH. Peter Anvinconfig X86_ESPFIX32
120534273f41SH. Peter Anvin	def_bool y
120634273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1207506f1d07SSam Ravnborg
1208197725deSH. Peter Anvinconfig X86_ESPFIX64
1209197725deSH. Peter Anvin	def_bool y
121034273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1211506f1d07SSam Ravnborg
12121ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12131ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12141ad83c85SAndy Lutomirski	default y
12151ad83c85SAndy Lutomirski	depends on X86_64
1216a7f7f624SMasahiro Yamada	help
12171ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12181ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12191ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12201ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12211ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12221ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12231ad83c85SAndy Lutomirski
12241ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12251ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12261ad83c85SAndy Lutomirski
12271ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12281ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12291ad83c85SAndy Lutomirski
1230111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1231111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1232a24ca997SThomas Gleixner	default y
1233a7f7f624SMasahiro Yamada	help
1234111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1235111e7b15SThomas Gleixner	  for legacy applications.
1236111e7b15SThomas Gleixner
1237c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1238c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1239c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1240c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1241c8137aceSThomas Gleixner	  modules.
1242c8137aceSThomas Gleixner
1243c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1244c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1245a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1246a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1247c8137aceSThomas Gleixner
1248506f1d07SSam Ravnborgconfig TOSHIBA
1249506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1250506f1d07SSam Ravnborg	depends on X86_32
1251a7f7f624SMasahiro Yamada	help
1252506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1253506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1255506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1256506f1d07SSam Ravnborg
1257506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1258506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1259506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1260506f1d07SSam Ravnborg
1261506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1262506f1d07SSam Ravnborg	  Say N otherwise.
1263506f1d07SSam Ravnborg
1264506f1d07SSam Ravnborgconfig I8K
1265039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1266ef775a0eSRandy Dunlap	depends on HWMON
1267ef775a0eSRandy Dunlap	depends on PROC_FS
1268039ae585SPali Rohár	select SENSORS_DELL_SMM
1269a7f7f624SMasahiro Yamada	help
1270039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1271039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1272039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1273039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1274039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1275039ae585SPali Rohár	  needed userspace package i8kutils.
1276506f1d07SSam Ravnborg
1277039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1278039ae585SPali Rohár	  use userspace package i8kutils.
1279506f1d07SSam Ravnborg	  Say N otherwise.
1280506f1d07SSam Ravnborg
1281506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12829ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12839ba16087SJan Beulich	depends on X86_32
1284a7f7f624SMasahiro Yamada	help
1285506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1286506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1287506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1288506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1289506f1d07SSam Ravnborg	  system.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12925e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1293506f1d07SSam Ravnborg
1294506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1295506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1296506f1d07SSam Ravnborg	  Say N otherwise.
1297506f1d07SSam Ravnborg
1298506f1d07SSam Ravnborgconfig MICROCODE
12999a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13009a2bc335SBorislav Petkov	default y
130180030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1302a7f7f624SMasahiro Yamada	help
1303506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13045f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13055f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13065f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13075f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13085f9c01aaSBorislav Petkov	  the Linux kernel.
1309506f1d07SSam Ravnborg
13105f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1311cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13125f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13135f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1314506f1d07SSam Ravnborg
1315c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1316c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1317c508c46eSBenjamin Gilbert	  config option.
1318506f1d07SSam Ravnborg
13198d86f390SPeter Orubaconfig MICROCODE_INTEL
1320e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13218d86f390SPeter Oruba	depends on MICROCODE
13228d86f390SPeter Oruba	default MICROCODE
1323a7f7f624SMasahiro Yamada	help
13248d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13258d86f390SPeter Oruba	  processors.
13268d86f390SPeter Oruba
1327b8989db9SAlan	  For the current Intel microcode data package go to
1328b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1329b8989db9SAlan	  'Linux Processor Microcode Data File'.
13308d86f390SPeter Oruba
133180cc9f10SPeter Orubaconfig MICROCODE_AMD
1332e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
133380cc9f10SPeter Oruba	depends on MICROCODE
1334a7f7f624SMasahiro Yamada	help
133580cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
133680cc9f10SPeter Oruba	  processors will be enabled.
133780cc9f10SPeter Oruba
1338506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1339c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1340c02f48e0SBorislav Petkov	default n
1341506f1d07SSam Ravnborg	depends on MICROCODE
1342a7f7f624SMasahiro Yamada	help
1343c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1344c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1345c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1346c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1347c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1348cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1349506f1d07SSam Ravnborg
1350506f1d07SSam Ravnborgconfig X86_MSR
1351506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1352a7f7f624SMasahiro Yamada	help
1353506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1354506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1355506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1356506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1357506f1d07SSam Ravnborg	  systems.
1358506f1d07SSam Ravnborg
1359506f1d07SSam Ravnborgconfig X86_CPUID
1360506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1361a7f7f624SMasahiro Yamada	help
1362506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1363506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1364506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1365506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1366506f1d07SSam Ravnborg
1367506f1d07SSam Ravnborgchoice
1368506f1d07SSam Ravnborg	prompt "High Memory Support"
13696fc108a0SJan Beulich	default HIGHMEM4G
1370506f1d07SSam Ravnborg	depends on X86_32
1371506f1d07SSam Ravnborg
1372506f1d07SSam Ravnborgconfig NOHIGHMEM
1373506f1d07SSam Ravnborg	bool "off"
1374a7f7f624SMasahiro Yamada	help
1375506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1376506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1377506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1378506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1379506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1380506f1d07SSam Ravnborg	  "high memory".
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1383506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1384506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1385506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1386506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1387506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1388506f1d07SSam Ravnborg	  possible.
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1391506f1d07SSam Ravnborg	  answer "4GB" here.
1392506f1d07SSam Ravnborg
1393506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1394506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1395506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1396506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1397506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1398506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1401506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1402506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1403506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1404506f1d07SSam Ravnborg	  kernel at boot time.)
1405506f1d07SSam Ravnborg
1406506f1d07SSam Ravnborg	  If unsure, say "off".
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborgconfig HIGHMEM4G
1409506f1d07SSam Ravnborg	bool "4GB"
1410a7f7f624SMasahiro Yamada	help
1411506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1412506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1413506f1d07SSam Ravnborg
1414506f1d07SSam Ravnborgconfig HIGHMEM64G
1415506f1d07SSam Ravnborg	bool "64GB"
1416225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1417506f1d07SSam Ravnborg	select X86_PAE
1418a7f7f624SMasahiro Yamada	help
1419506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1420506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1421506f1d07SSam Ravnborg
1422506f1d07SSam Ravnborgendchoice
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborgchoice
14256a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1426506f1d07SSam Ravnborg	default VMSPLIT_3G
1427506f1d07SSam Ravnborg	depends on X86_32
1428a7f7f624SMasahiro Yamada	help
1429506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1432506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1433506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1434506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1435506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1436506f1d07SSam Ravnborg	  available to user programs, making the address space there
1437506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1438506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1439506f1d07SSam Ravnborg	  kernel modules.
1440506f1d07SSam Ravnborg
1441506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1442506f1d07SSam Ravnborg	  option alone!
1443506f1d07SSam Ravnborg
1444506f1d07SSam Ravnborg	config VMSPLIT_3G
1445506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1446506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1447506f1d07SSam Ravnborg		depends on !X86_PAE
1448506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1449506f1d07SSam Ravnborg	config VMSPLIT_2G
1450506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1451506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1452506f1d07SSam Ravnborg		depends on !X86_PAE
1453506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1454506f1d07SSam Ravnborg	config VMSPLIT_1G
1455506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1456506f1d07SSam Ravnborgendchoice
1457506f1d07SSam Ravnborg
1458506f1d07SSam Ravnborgconfig PAGE_OFFSET
1459506f1d07SSam Ravnborg	hex
1460506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1461506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1462506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1463506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1464506f1d07SSam Ravnborg	default 0xC0000000
1465506f1d07SSam Ravnborg	depends on X86_32
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborgconfig HIGHMEM
14683c2362e6SHarvey Harrison	def_bool y
1469506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1470506f1d07SSam Ravnborg
1471506f1d07SSam Ravnborgconfig X86_PAE
14729ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1473506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1474d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14759d99c712SChristian Melki	select SWIOTLB
1476a7f7f624SMasahiro Yamada	help
1477506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1478506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1479506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1480506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1481506f1d07SSam Ravnborg
148277ef56e4SKirill A. Shutemovconfig X86_5LEVEL
148377ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
148418ec1eafSKirill A. Shutemov	default y
1485eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1486162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148777ef56e4SKirill A. Shutemov	depends on X86_64
1488a7f7f624SMasahiro Yamada	help
148977ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149077ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149177ef56e4SKirill A. Shutemov	  physical address space.
149277ef56e4SKirill A. Shutemov
149377ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
149477ef56e4SKirill A. Shutemov
14956657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14966657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149777ef56e4SKirill A. Shutemov
1498cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149977ef56e4SKirill A. Shutemov	  information.
150077ef56e4SKirill A. Shutemov
150177ef56e4SKirill A. Shutemov	  Say N if unsure.
150277ef56e4SKirill A. Shutemov
150310971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1504e5008abeSLuis R. Rodriguez	def_bool y
15052e1da13fSVlastimil Babka	depends on X86_64
1506a7f7f624SMasahiro Yamada	help
150710971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150810971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150910971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151010971ab2SIngo Molnar	  that we have them enabled.
15119e899816SNick Piggin
15125c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15135c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15145c280cf6SThomas Gleixner	depends on DEBUG_FS
1515a7f7f624SMasahiro Yamada	help
1516b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1517a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15185c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15195c280cf6SThomas Gleixner
15207744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15217744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15227744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
152382fef0adSDavid Rientjes	select DMA_COHERENT_POOL
152494d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1525ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15269087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1527597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
152822916417STom Lendacky	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1529aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
1530a7f7f624SMasahiro Yamada	help
15317744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15327744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15337744ccdbSTom Lendacky	  Encryption (SME).
15347744ccdbSTom Lendacky
15357744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15367744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15377744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1538a7f7f624SMasahiro Yamada	help
15397744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15407744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15417744ccdbSTom Lendacky
15427744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15437744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15447744ccdbSTom Lendacky
15457744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15467744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15477744ccdbSTom Lendacky
1548506f1d07SSam Ravnborg# Common NUMA Features
1549506f1d07SSam Ravnborgconfig NUMA
1550e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1551506f1d07SSam Ravnborg	depends on SMP
1552b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1554*7ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1555a7f7f624SMasahiro Yamada	help
1556e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1557fd51b2d7SKOSAKI Motohiro
1558506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1559506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1560506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1561506f1d07SSam Ravnborg
1562c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1563fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1564fd51b2d7SKOSAKI Motohiro
1565b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15667cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1567fd51b2d7SKOSAKI Motohiro
1568fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1569506f1d07SSam Ravnborg
1570eec1d4faSHans Rosenfeldconfig AMD_NUMA
15713c2362e6SHarvey Harrison	def_bool y
15723c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15735da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1574a7f7f624SMasahiro Yamada	help
1575eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1576eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1577eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1578eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1579eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1580506f1d07SSam Ravnborg
1581506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15823c2362e6SHarvey Harrison	def_bool y
15833c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1584506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1585506f1d07SSam Ravnborg	select ACPI_NUMA
1586a7f7f624SMasahiro Yamada	help
1587506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1588506f1d07SSam Ravnborg
1589506f1d07SSam Ravnborgconfig NUMA_EMU
1590506f1d07SSam Ravnborg	bool "NUMA emulation"
15911b7e03efSTejun Heo	depends on NUMA
1592a7f7f624SMasahiro Yamada	help
1593506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1594506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1595506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1596506f1d07SSam Ravnborg
1597506f1d07SSam Ravnborgconfig NODES_SHIFT
1598d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159951591e31SDavid Rientjes	range 1 10
160051591e31SDavid Rientjes	default "10" if MAXSMP
1601506f1d07SSam Ravnborg	default "6" if X86_64
1602506f1d07SSam Ravnborg	default "3"
1603a9ee6cf5SMike Rapoport	depends on NUMA
1604a7f7f624SMasahiro Yamada	help
16051184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1606692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1609506f1d07SSam Ravnborg	def_bool y
16103b16651fSTejun Heo	depends on X86_32 && !NUMA
1611506f1d07SSam Ravnborg
1612506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1613506f1d07SSam Ravnborg	def_bool y
16146ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1615506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1616506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1617506f1d07SSam Ravnborg
16183b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16196ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16203b16651fSTejun Heo
1621506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1622506f1d07SSam Ravnborg	def_bool y
1623b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1624506f1d07SSam Ravnborg
1625506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1626a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16275c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1628a0842b70SToshi Kani	help
1629a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1630cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1631a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1632506f1d07SSam Ravnborg
16333b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16343b16651fSTejun Heo	def_bool y
16353b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16363b16651fSTejun Heo
1637a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1638a29815a3SAvi Kivity	hex
1639a29815a3SAvi Kivity	default 0 if X86_32
1640a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1641a29815a3SAvi Kivity
16427a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16437a67832cSDan Williams	bool
16447a67832cSDan Williams
1645ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16467a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16479f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16489f53f9faSDan Williams	depends on BLK_DEV
16497a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16507b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16519f53f9faSDan Williams	select LIBNVDIMM
1652ec776ef6SChristoph Hellwig	help
1653ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1654ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1655ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1656ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1657ec776ef6SChristoph Hellwig
1658ec776ef6SChristoph Hellwig	  Say Y if unsure.
1659ec776ef6SChristoph Hellwig
1660506f1d07SSam Ravnborgconfig HIGHPTE
1661506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16626fc108a0SJan Beulich	depends on HIGHMEM
1663a7f7f624SMasahiro Yamada	help
1664506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1665506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1666506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1667506f1d07SSam Ravnborg	  entries in high memory.
1668506f1d07SSam Ravnborg
16699f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16709f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1671a7f7f624SMasahiro Yamada	help
16729f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16739f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16749f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16759f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16769f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16779f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16789f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16798c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16809f077871SJeremy Fitzhardinge
16819f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16829f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16839f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16849f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16859f077871SJeremy Fitzhardinge
16869f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16879f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16889f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16899f077871SJeremy Fitzhardinge	  memory.
16909f077871SJeremy Fitzhardinge
1691c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1692c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1693c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1694c885df50SJeremy Fitzhardinge	default y
1695a7f7f624SMasahiro Yamada	help
1696c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1697c885df50SJeremy Fitzhardinge	  on or off.
1698c885df50SJeremy Fitzhardinge
1699506f1d07SSam Ravnborgconfig MATH_EMULATION
1700506f1d07SSam Ravnborg	bool
1701a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
170287d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1703a7f7f624SMasahiro Yamada	help
1704506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1705506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1706506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1707506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1708506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1709506f1d07SSam Ravnborg	  coprocessor or this emulation.
1710506f1d07SSam Ravnborg
1711506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1712506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1713506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1714506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1715506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1716506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1717506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1718506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1719506f1d07SSam Ravnborg
1720506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1721506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1722506f1d07SSam Ravnborg
1723506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1724506f1d07SSam Ravnborg	  kernel, it won't hurt.
1725506f1d07SSam Ravnborg
1726506f1d07SSam Ravnborgconfig MTRR
17276fc108a0SJan Beulich	def_bool y
17286a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1729a7f7f624SMasahiro Yamada	help
1730506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1731506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1732506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1733506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1734506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1735506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1736506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1737506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1738506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1741506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1742506f1d07SSam Ravnborg	  as well:
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1745506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1746506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1747506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1748506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1749506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1750506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1753506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1754506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1755506f1d07SSam Ravnborg
1756506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1757506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1758506f1d07SSam Ravnborg
1759cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1760506f1d07SSam Ravnborg
176195ffa243SYinghai Luconfig MTRR_SANITIZER
17622ffb3501SYinghai Lu	def_bool y
176395ffa243SYinghai Lu	prompt "MTRR cleanup support"
176495ffa243SYinghai Lu	depends on MTRR
1765a7f7f624SMasahiro Yamada	help
1766aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1767aba3728cSThomas Gleixner	  add writeback entries.
176895ffa243SYinghai Lu
1769aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1770692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1771aba3728cSThomas Gleixner	  mtrr_chunk_size.
177295ffa243SYinghai Lu
17732ffb3501SYinghai Lu	  If unsure, say Y.
177495ffa243SYinghai Lu
177595ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1776f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1777f5098d62SYinghai Lu	range 0 1
1778f5098d62SYinghai Lu	default "0"
177995ffa243SYinghai Lu	depends on MTRR_SANITIZER
1780a7f7f624SMasahiro Yamada	help
1781f5098d62SYinghai Lu	  Enable mtrr cleanup default value
178295ffa243SYinghai Lu
178312031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
178412031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
178512031a62SYinghai Lu	range 0 7
178612031a62SYinghai Lu	default "1"
178712031a62SYinghai Lu	depends on MTRR_SANITIZER
1788a7f7f624SMasahiro Yamada	help
178912031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1790aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
179112031a62SYinghai Lu
17922e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17936fc108a0SJan Beulich	def_bool y
17946a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17952a8a2719SIngo Molnar	depends on MTRR
1796a7f7f624SMasahiro Yamada	help
17972e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1798042b78e4SVenki Pallipadi
17992e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18002e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18012e5d9c85Svenkatesh.pallipadi@intel.com
18022e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1803042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18042e5d9c85Svenkatesh.pallipadi@intel.com
18052e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18062e5d9c85Svenkatesh.pallipadi@intel.com
180746cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
180846cf98cdSVenkatesh Pallipadi	def_bool y
180946cf98cdSVenkatesh Pallipadi	depends on X86_PAT
181046cf98cdSVenkatesh Pallipadi
1811628c6246SH. Peter Anvinconfig ARCH_RANDOM
1812628c6246SH. Peter Anvin	def_bool y
1813628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1814a7f7f624SMasahiro Yamada	help
1815628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1816628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1817628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1818628c6246SH. Peter Anvin	  secure hardware random number generator.
1819628c6246SH. Peter Anvin
182051ae4a2dSH. Peter Anvinconfig X86_SMAP
182151ae4a2dSH. Peter Anvin	def_bool y
182251ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1823a7f7f624SMasahiro Yamada	help
182451ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
182551ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
182651ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
182751ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
182851ae4a2dSH. Peter Anvin
182951ae4a2dSH. Peter Anvin	  If unsure, say Y.
183051ae4a2dSH. Peter Anvin
1831b971880fSBabu Mogerconfig X86_UMIP
1832796ebc81SRicardo Neri	def_bool y
1833b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1834a7f7f624SMasahiro Yamada	help
1835b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1836b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1837b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1838b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1839b971880fSBabu Moger	  information about the hardware state.
1840796ebc81SRicardo Neri
1841796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1842796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1843796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1844796ebc81SRicardo Neri	  results are dummy.
1845aa35f896SRicardo Neri
184635e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
184738f3e775SBabu Moger	prompt "Memory Protection Keys"
184835e97790SDave Hansen	def_bool y
1849284244a9SDave Hansen	# Note: only available in 64-bit mode
185038f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
185152c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
185252c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1853a7f7f624SMasahiro Yamada	help
1854284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1855284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1856284244a9SDave Hansen	  page tables when an application changes protection domains.
1857284244a9SDave Hansen
18581eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1859284244a9SDave Hansen
1860284244a9SDave Hansen	  If unsure, say y.
186135e97790SDave Hansen
1862db616173SMichal Hockochoice
1863db616173SMichal Hocko	prompt "TSX enable mode"
1864db616173SMichal Hocko	depends on CPU_SUP_INTEL
1865db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1866db616173SMichal Hocko	help
1867db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1868db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1869db616173SMichal Hocko	  can lead to a noticeable performance boost.
1870db616173SMichal Hocko
1871db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1872db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1873db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1874db616173SMichal Hocko
1875db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1876db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1877db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1878db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1879db616173SMichal Hocko	  for the particular machine.
1880db616173SMichal Hocko
1881db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1882db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1883db616173SMichal Hocko	  details.
1884db616173SMichal Hocko
1885db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1886db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1887db616173SMichal Hocko	  relevant.
1888db616173SMichal Hocko
1889db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1890db616173SMichal Hocko	bool "off"
1891db616173SMichal Hocko	help
1892db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1893db616173SMichal Hocko
1894db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1895db616173SMichal Hocko	bool "on"
1896db616173SMichal Hocko	help
1897db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1898db616173SMichal Hocko	  line parameter.
1899db616173SMichal Hocko
1900db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1901db616173SMichal Hocko	bool "auto"
1902db616173SMichal Hocko	help
1903db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1904db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1905db616173SMichal Hockoendchoice
1906db616173SMichal Hocko
1907e7e05452SSean Christophersonconfig X86_SGX
1908e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1909e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1910e7e05452SSean Christopherson	depends on CRYPTO=y
1911e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1912e7e05452SSean Christopherson	select SRCU
1913e7e05452SSean Christopherson	select MMU_NOTIFIER
1914901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
1915e7e05452SSean Christopherson	help
1916e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1917e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1918e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1919e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1920e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1921e7e05452SSean Christopherson	  hardware.
1922e7e05452SSean Christopherson
1923e7e05452SSean Christopherson	  If unsure, say N.
1924e7e05452SSean Christopherson
1925506f1d07SSam Ravnborgconfig EFI
19269ba16087SJan Beulich	bool "EFI runtime service support"
19275b83683fSHuang, Ying	depends on ACPI
1928f6ce5002SSergey Vlasov	select UCS2_STRING
1929022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19301ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1931a7f7f624SMasahiro Yamada	help
19328b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1933506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1934506f1d07SSam Ravnborg
19358b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19368b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19378b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19388b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19398b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19408b2cb7a8SHuang, Ying	  platforms.
1941506f1d07SSam Ravnborg
1942291f3632SMatt Flemingconfig EFI_STUB
1943291f3632SMatt Fleming	bool "EFI stub support"
1944b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19458f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19467b2a583aSMatt Fleming	select RELOCATABLE
1947a7f7f624SMasahiro Yamada	help
1948291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1949291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1950291f3632SMatt Fleming
19514f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19520c759662SMatt Fleming
19537d453eeeSMatt Flemingconfig EFI_MIXED
19547d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19557d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1956a7f7f624SMasahiro Yamada	help
19577d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19587d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19597d453eeeSMatt Fleming	   mode.
19607d453eeeSMatt Fleming
19617d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19627d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19637d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19647d453eeeSMatt Fleming
19657d453eeeSMatt Fleming	   If unsure, say N.
19667d453eeeSMatt Fleming
19678636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1968506f1d07SSam Ravnborg
1969506f1d07SSam Ravnborgconfig KEXEC
1970506f1d07SSam Ravnborg	bool "kexec system call"
19712965faa5SDave Young	select KEXEC_CORE
1972a7f7f624SMasahiro Yamada	help
1973506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1974506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1975506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1976506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1977506f1d07SSam Ravnborg
1978506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1979506f1d07SSam Ravnborg
1980506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1981506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1982bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1983bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1984bf220695SGeert Uytterhoeven	  made.
1985506f1d07SSam Ravnborg
198674ca317cSVivek Goyalconfig KEXEC_FILE
198774ca317cSVivek Goyal	bool "kexec file based system call"
19882965faa5SDave Young	select KEXEC_CORE
198974ca317cSVivek Goyal	select BUILD_BIN2C
199074ca317cSVivek Goyal	depends on X86_64
199174ca317cSVivek Goyal	depends on CRYPTO=y
199274ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
1993a7f7f624SMasahiro Yamada	help
199474ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
199574ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
199674ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
199774ca317cSVivek Goyal	  accepted by previous system call.
199874ca317cSVivek Goyal
1999b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2000b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2001b799a09fSAKASHI Takahiro
200299d5cadfSJiri Bohacconfig KEXEC_SIG
20038e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
200474ca317cSVivek Goyal	depends on KEXEC_FILE
2005a7f7f624SMasahiro Yamada	help
200699d5cadfSJiri Bohac
200799d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
200899d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
200999d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
201099d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
201199d5cadfSJiri Bohac
201299d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
201399d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
201499d5cadfSJiri Bohac	  loaded in order for this to work.
201599d5cadfSJiri Bohac
201699d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
201799d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
201899d5cadfSJiri Bohac	depends on KEXEC_SIG
2019a7f7f624SMasahiro Yamada	help
20208e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2021d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20228e7d8381SVivek Goyal
20238e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20248e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
202599d5cadfSJiri Bohac	depends on KEXEC_SIG
20268e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20278e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2028a7f7f624SMasahiro Yamada	help
20298e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20308e7d8381SVivek Goyal
2031506f1d07SSam Ravnborgconfig CRASH_DUMP
203204b69447SPavel Machek	bool "kernel crash dumps"
2033506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2034a7f7f624SMasahiro Yamada	help
2035506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2036506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2037506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2038506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2039506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2040506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2041506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2042506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2043330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2044506f1d07SSam Ravnborg
20453ab83521SHuang Yingconfig KEXEC_JUMP
20466ea30386SKees Cook	bool "kexec jump"
2047fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2048a7f7f624SMasahiro Yamada	help
204989081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
205089081d17SHuang Ying	  code in physical address mode via KEXEC
20513ab83521SHuang Ying
2052506f1d07SSam Ravnborgconfig PHYSICAL_START
20536a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2054ceefccc9SH. Peter Anvin	default "0x1000000"
2055a7f7f624SMasahiro Yamada	help
2056506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2057506f1d07SSam Ravnborg
2058506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2059506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2060506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2061506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2062506f1d07SSam Ravnborg	  address.
2063506f1d07SSam Ravnborg
2064506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2065506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2066506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2067506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2068506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2069506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2070506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2071506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2072506f1d07SSam Ravnborg
2073ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2074ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2075ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2076ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2077ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2078ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2079ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2080330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2081ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2082506f1d07SSam Ravnborg
2083506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2084506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2085506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2086506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2087506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2088506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2089506f1d07SSam Ravnborg	  line.
2090506f1d07SSam Ravnborg
2091506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2092506f1d07SSam Ravnborg
2093506f1d07SSam Ravnborgconfig RELOCATABLE
209426717808SH. Peter Anvin	bool "Build a relocatable kernel"
209526717808SH. Peter Anvin	default y
2096a7f7f624SMasahiro Yamada	help
2097506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2098506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2099506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2100506f1d07SSam Ravnborg	  but are discarded at runtime.
2101506f1d07SSam Ravnborg
2102506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2103506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2104506f1d07SSam Ravnborg	  kernel.
2105506f1d07SSam Ravnborg
2106506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2107506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21088ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2109506f1d07SSam Ravnborg
21108ab3820fSKees Cookconfig RANDOMIZE_BASE
2111e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21128ab3820fSKees Cook	depends on RELOCATABLE
21136807c846SIngo Molnar	default y
2114a7f7f624SMasahiro Yamada	help
2115e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2116e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2117e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2118e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2119e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2120e8581e3dSBaoquan He	  code internals.
2121e8581e3dSBaoquan He
2122ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2123ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2124ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2125ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2126ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2127ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2128ed9f007eSKees Cook
2129ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2130ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2131ed9f007eSKees Cook	  512MB (8 bits of entropy).
21328ab3820fSKees Cook
2133a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2134e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2135e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2136ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2137ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2138ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2139ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2140ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2141ed9f007eSKees Cook	  limited due to memory layouts.
2142e8581e3dSBaoquan He
21436807c846SIngo Molnar	  If unsure, say Y.
2144da2b6fb9SKees Cook
21458ab3820fSKees Cook# Relocation on x86 needs some additional build support
2146845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2147845adf72SH. Peter Anvin	def_bool y
21488ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2149845adf72SH. Peter Anvin
2150506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2151a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21528ab3820fSKees Cook	default "0x200000"
2153a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2154a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2155a7f7f624SMasahiro Yamada	help
2156506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2157506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2158506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2159506f1d07SSam Ravnborg
2160506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2161506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2162506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2163506f1d07SSam Ravnborg
2164506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2165506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2166506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2167506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2168506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2169506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2170506f1d07SSam Ravnborg	  above alignment restrictions.
2171506f1d07SSam Ravnborg
2172a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2173a0215061SKees Cook	  this value must be a multiple of 0x200000.
2174a0215061SKees Cook
2175506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2176506f1d07SSam Ravnborg
2177eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2178eedb92abSKirill A. Shutemov	bool
2179a7f7f624SMasahiro Yamada	help
2180eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2181eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2182eedb92abSKirill A. Shutemov
21830483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21840483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21850483e1faSThomas Garnier	depends on X86_64
21860483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2187eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21880483e1faSThomas Garnier	default RANDOMIZE_BASE
2189a7f7f624SMasahiro Yamada	help
21900483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21910483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21920483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21930483e1faSThomas Garnier
21940483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21950483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21960483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21970483e1faSThomas Garnier	   addresses for each memory section.
21980483e1faSThomas Garnier
21996807c846SIngo Molnar	   If unsure, say Y.
22000483e1faSThomas Garnier
220190397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
220290397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
220390397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
220490397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
220590397a41SThomas Garnier	default "0x0"
220690397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
220790397a41SThomas Garnier	range 0x0 0x40
2208a7f7f624SMasahiro Yamada	help
220990397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
221090397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
221190397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
221290397a41SThomas Garnier	   address randomization.
221390397a41SThomas Garnier
221490397a41SThomas Garnier	   If unsure, leave at the default value.
221590397a41SThomas Garnier
2216506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2217bebd024eSThomas Gleixner	def_bool y
221840b31360SStephen Rothwell	depends on SMP
2219506f1d07SSam Ravnborg
222080aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
222180aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22222c922cd0SKees Cook	depends on HOTPLUG_CPU
2223a7f7f624SMasahiro Yamada	help
222480aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
222580aa1dffSFenghua Yu
222680aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
222780aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
222880aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
222980aa1dffSFenghua Yu
223080aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
223180aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
223280aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
223380aa1dffSFenghua Yu
223480aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
223580aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
223680aa1dffSFenghua Yu
223780aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
223880aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
223980aa1dffSFenghua Yu	  be other CPU0 dependencies.
224080aa1dffSFenghua Yu
224180aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
224280aa1dffSFenghua Yu	  you enable this feature.
224380aa1dffSFenghua Yu
224480aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
224580aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
224680aa1dffSFenghua Yu	  parameter cpu0_hotplug.
224780aa1dffSFenghua Yu
2248a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2249a71c8bc5SFenghua Yu	def_bool n
2250a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22512c922cd0SKees Cook	depends on HOTPLUG_CPU
2252a7f7f624SMasahiro Yamada	help
2253a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2254a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2255a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2256a71c8bc5SFenghua Yu
2257a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2258a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2259a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2260a71c8bc5SFenghua Yu
2261a71c8bc5SFenghua Yu	  If unsure, say N.
2262a71c8bc5SFenghua Yu
2263506f1d07SSam Ravnborgconfig COMPAT_VDSO
2264b0b49f26SAndy Lutomirski	def_bool n
2265b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2266953fee1dSIngo Molnar	depends on COMPAT_32
2267a7f7f624SMasahiro Yamada	help
2268b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2269b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2270b0b49f26SAndy Lutomirski	  indicated in its segment table.
2271e84446deSRandy Dunlap
2272b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2273b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2274b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2275b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2276b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2277506f1d07SSam Ravnborg
2278b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2279b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2280b0b49f26SAndy Lutomirski
2281b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2282b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2283b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2284b0b49f26SAndy Lutomirski
2285b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2286b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2287506f1d07SSam Ravnborg
22883dc33bd3SKees Cookchoice
22893dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22903dc33bd3SKees Cook	depends on X86_64
2291625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
22923dc33bd3SKees Cook	help
22933dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22943dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22953dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22963dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22973dc33bd3SKees Cook
22983dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2299bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23003dc33bd3SKees Cook
23013dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23023dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23033dc33bd3SKees Cook	  to improve security.
23043dc33bd3SKees Cook
2305bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23063dc33bd3SKees Cook
23073dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2308bd49e16eSAndy Lutomirski		bool "Full emulation"
23093dc33bd3SKees Cook		help
2310bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2311bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2312bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2313bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2314bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2315bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2316bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2317bd49e16eSAndy Lutomirski
2318bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2319bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2320bd49e16eSAndy Lutomirski
2321bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2322bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2323bd49e16eSAndy Lutomirski		help
2324bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2325bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2326bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2327bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2328bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2329bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2330bd49e16eSAndy Lutomirski		  buffer.
23313dc33bd3SKees Cook
23323dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23333dc33bd3SKees Cook		bool "None"
23343dc33bd3SKees Cook		help
23353dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23363dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23373dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23383dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23393dc33bd3SKees Cook		  malicious userspace programs can be identified.
23403dc33bd3SKees Cook
23413dc33bd3SKees Cookendchoice
23423dc33bd3SKees Cook
2343516cbf37STim Birdconfig CMDLINE_BOOL
2344516cbf37STim Bird	bool "Built-in kernel command line"
2345a7f7f624SMasahiro Yamada	help
2346516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2347516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2348516cbf37STim Bird	  necessary or convenient to provide some or all of the
2349516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2350516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2351516cbf37STim Bird
2352516cbf37STim Bird	  To compile command line arguments into the kernel,
2353516cbf37STim Bird	  set this option to 'Y', then fill in the
235469711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2355516cbf37STim Bird
2356516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2357516cbf37STim Bird	  should leave this option set to 'N'.
2358516cbf37STim Bird
2359516cbf37STim Birdconfig CMDLINE
2360516cbf37STim Bird	string "Built-in kernel command string"
2361516cbf37STim Bird	depends on CMDLINE_BOOL
2362516cbf37STim Bird	default ""
2363a7f7f624SMasahiro Yamada	help
2364516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2365516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2366516cbf37STim Bird	  command line at boot time, it is appended to this string to
2367516cbf37STim Bird	  form the full kernel command line, when the system boots.
2368516cbf37STim Bird
2369516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2370516cbf37STim Bird	  change this behavior.
2371516cbf37STim Bird
2372516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2373516cbf37STim Bird	  by the boot loader) should specify the device for the root
2374516cbf37STim Bird	  file system.
2375516cbf37STim Bird
2376516cbf37STim Birdconfig CMDLINE_OVERRIDE
2377516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2378645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2379a7f7f624SMasahiro Yamada	help
2380516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2381516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2382516cbf37STim Bird
2383516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2384516cbf37STim Bird	  be set to 'N' under normal conditions.
2385516cbf37STim Bird
2386a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2387a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2388a5b9e5a2SAndy Lutomirski	default y
2389a7f7f624SMasahiro Yamada	help
2390a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2391a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2392a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2393a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2394a5b9e5a2SAndy Lutomirski	  threading libraries.
2395a5b9e5a2SAndy Lutomirski
2396a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2397a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2398a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2399a5b9e5a2SAndy Lutomirski
2400a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2401a5b9e5a2SAndy Lutomirski
24023aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24033aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24043aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24053aac3ebeSThomas Gleixner	help
24063aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24073aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24083aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24093aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24103aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24113aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24123aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24133aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24143aac3ebeSThomas Gleixner	  never get a signal delivered.
24153aac3ebeSThomas Gleixner
24163aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24173aac3ebeSThomas Gleixner
2418b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2419b700e7f0SSeth Jennings
2420506f1d07SSam Ravnborgendmenu
2421506f1d07SSam Ravnborg
24223072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24233072e413SMichal Hocko	def_bool y
24245c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24253072e413SMichal Hocko
2426f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2427f91ef222SOscar Salvador	def_bool y
2428f91ef222SOscar Salvador
2429da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2430e279b6c1SSam Ravnborg
2431e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24323c2362e6SHarvey Harrison	def_bool y
243344556530SZhimin Gu	depends on HIBERNATION
2434e279b6c1SSam Ravnborg
2435e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2436e279b6c1SSam Ravnborg
2437e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2438e279b6c1SSam Ravnborg
2439a6b68076SAndi Kleenconfig X86_APM_BOOT
24406fc108a0SJan Beulich	def_bool y
2441282e5aabSPaul Bolle	depends on APM
2442a6b68076SAndi Kleen
2443e279b6c1SSam Ravnborgmenuconfig APM
2444e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2445efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2446a7f7f624SMasahiro Yamada	help
2447e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2448e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2449e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2450e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2451e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2452e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2453e279b6c1SSam Ravnborg
2454e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2455e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2456e279b6c1SSam Ravnborg
2457e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2458e279b6c1SSam Ravnborg	  machines with more than one CPU.
2459e279b6c1SSam Ravnborg
2460e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2461151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24622dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2463e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2464e279b6c1SSam Ravnborg
2465e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2466e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2467e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2468e279b6c1SSam Ravnborg
2469e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2470e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2471e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2472e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2473e279b6c1SSam Ravnborg
2474e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2475e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2476e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2477e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2478e279b6c1SSam Ravnborg	  APM in your BIOS).
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2481e279b6c1SSam Ravnborg	  "weird" problems:
2482e279b6c1SSam Ravnborg
2483e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2484e279b6c1SSam Ravnborg	  enabled.
2485e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2486e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2487e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2488e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2489e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2490e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2491e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2492e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2493e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2494e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2495e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2496e279b6c1SSam Ravnborg	  11) exchange RAM chips
2497e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2500e279b6c1SSam Ravnborg	  module will be called apm.
2501e279b6c1SSam Ravnborg
2502e279b6c1SSam Ravnborgif APM
2503e279b6c1SSam Ravnborg
2504e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2505e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2506a7f7f624SMasahiro Yamada	help
2507e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2508e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2509e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2510e279b6c1SSam Ravnborg
2511e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2512e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2513a7f7f624SMasahiro Yamada	help
2514e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2515e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2516e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2517e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2518e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2519e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2520e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2521e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2522e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2523e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2524e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2525e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2526e279b6c1SSam Ravnborg	  this feature.
2527e279b6c1SSam Ravnborg
2528e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2529dd8af076SLen Brown	depends on CPU_IDLE
2530e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2531a7f7f624SMasahiro Yamada	help
2532e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2533e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2534e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2535e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2536e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2537e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2538e279b6c1SSam Ravnborg	  this option does nothing.)
2539e279b6c1SSam Ravnborg
2540e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2541e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2542a7f7f624SMasahiro Yamada	help
2543e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2544e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2545e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2546e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2547e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2548e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2549e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2550e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2551e279b6c1SSam Ravnborg	  especially if you are using gpm.
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2554e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2555a7f7f624SMasahiro Yamada	help
2556e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2557e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2558e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2559e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2560e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2561e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2562e279b6c1SSam Ravnborg
2563e279b6c1SSam Ravnborgendif # APM
2564e279b6c1SSam Ravnborg
2565bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2566e279b6c1SSam Ravnborg
2567e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2568e279b6c1SSam Ravnborg
256927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
257027471fdbSAndy Henroid
2571e279b6c1SSam Ravnborgendmenu
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2575e279b6c1SSam Ravnborg
2576e279b6c1SSam Ravnborgchoice
2577e279b6c1SSam Ravnborg	prompt "PCI access mode"
2578efefa6f6SIngo Molnar	depends on X86_32 && PCI
2579e279b6c1SSam Ravnborg	default PCI_GOANY
2580a7f7f624SMasahiro Yamada	help
2581e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2582e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2583e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2584e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2585e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2588e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2589e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2590e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2591e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2592e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2593e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2594e279b6c1SSam Ravnborg
2595e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2596e279b6c1SSam Ravnborg	bool "BIOS"
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2599e279b6c1SSam Ravnborg	bool "MMConfig"
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2602e279b6c1SSam Ravnborg	bool "Direct"
2603e279b6c1SSam Ravnborg
26043ef0e1f8SAndres Salomonconfig PCI_GOOLPC
260576fb6570SDaniel Drake	bool "OLPC XO-1"
26063ef0e1f8SAndres Salomon	depends on OLPC
26073ef0e1f8SAndres Salomon
26082bdd1b03SAndres Salomonconfig PCI_GOANY
26092bdd1b03SAndres Salomon	bool "Any"
26102bdd1b03SAndres Salomon
2611e279b6c1SSam Ravnborgendchoice
2612e279b6c1SSam Ravnborg
2613e279b6c1SSam Ravnborgconfig PCI_BIOS
26143c2362e6SHarvey Harrison	def_bool y
2615efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2616e279b6c1SSam Ravnborg
2617e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2618e279b6c1SSam Ravnborgconfig PCI_DIRECT
26193c2362e6SHarvey Harrison	def_bool y
26200aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2621e279b6c1SSam Ravnborg
2622e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2623b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2624b45c9f36SJan Kiszka	default y
26254590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2626b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2627e279b6c1SSam Ravnborg
26283ef0e1f8SAndres Salomonconfig PCI_OLPC
26292bdd1b03SAndres Salomon	def_bool y
26302bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26313ef0e1f8SAndres Salomon
2632b5401a96SAlex Nixonconfig PCI_XEN
2633b5401a96SAlex Nixon	def_bool y
2634b5401a96SAlex Nixon	depends on PCI && XEN
2635b5401a96SAlex Nixon
26368364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26378364e1f8SJan Kiszka	def_bool y
26388364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2639e279b6c1SSam Ravnborg
26403f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26416a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26426ea30386SKees Cook	depends on PCI
26433f6ea84aSIra W. Snyder	help
26443f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26453f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26463f6ea84aSIra W. Snyder	  not have ACPI.
26473f6ea84aSIra W. Snyder
264864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
264964a5fed6SBjorn Helgaas	  is known to be incomplete.
265064a5fed6SBjorn Helgaas
265164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
265264a5fed6SBjorn Helgaas
26533a495511SWilliam Breathitt Grayconfig ISA_BUS
265417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26553a495511SWilliam Breathitt Gray	help
265617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
265717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
265817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
265917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
266017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26613a495511SWilliam Breathitt Gray
26623a495511SWilliam Breathitt Gray	  If unsure, say N.
26633a495511SWilliam Breathitt Gray
26641c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2665e279b6c1SSam Ravnborgconfig ISA_DMA_API
26661c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26671c00f016SDavid Rientjes	default y
26681c00f016SDavid Rientjes	help
26691c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26701c00f016SDavid Rientjes	  If unsure, say Y.
2671e279b6c1SSam Ravnborg
267251e68d05SLinus Torvaldsif X86_32
267351e68d05SLinus Torvalds
2674e279b6c1SSam Ravnborgconfig ISA
2675e279b6c1SSam Ravnborg	bool "ISA support"
2676a7f7f624SMasahiro Yamada	help
2677e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2678e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2679e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2680e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2681e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2682e279b6c1SSam Ravnborg
2683e279b6c1SSam Ravnborgconfig SCx200
2684e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2685a7f7f624SMasahiro Yamada	help
2686e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2687e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2688e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2689e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2690e279b6c1SSam Ravnborg
2691e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2692e279b6c1SSam Ravnborg
2693e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2694e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2695592913ecSJohn Stultz	depends on SCx200
2696e279b6c1SSam Ravnborg	default y
2697a7f7f624SMasahiro Yamada	help
2698e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2699e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2700e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2701e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2702e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2703e279b6c1SSam Ravnborg
27043ef0e1f8SAndres Salomonconfig OLPC
27053ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
270654008979SThomas Gleixner	depends on !X86_PAE
27073c554946SAndres Salomon	select GPIOLIB
2708dc3119e7SThomas Gleixner	select OF
270945bb1674SDaniel Drake	select OF_PROMTREE
2710b4e51854SGrant Likely	select IRQ_DOMAIN
27110c3d931bSLubomir Rintel	select OLPC_EC
2712a7f7f624SMasahiro Yamada	help
27133ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27143ef0e1f8SAndres Salomon	  XO hardware.
27153ef0e1f8SAndres Salomon
2716a3128588SDaniel Drakeconfig OLPC_XO1_PM
2717a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2718fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2719a7f7f624SMasahiro Yamada	help
272097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2721bf1ebf00SDaniel Drake
2722cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2723cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2724cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2725a7f7f624SMasahiro Yamada	help
2726cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2727cfee9597SDaniel Drake	  programmable wakeup source.
2728cfee9597SDaniel Drake
27297feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27307feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
273192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2732ed8e47feSRandy Dunlap	depends on INPUT=y
2733d8d01a63SDaniel Drake	select POWER_SUPPLY
2734a7f7f624SMasahiro Yamada	help
27357feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27367bc74b3dSDaniel Drake	   - EC-driven system wakeups
27377feda8e9SDaniel Drake	   - Power button
27387bc74b3dSDaniel Drake	   - Ebook switch
27392cf2baeaSDaniel Drake	   - Lid switch
2740e1040ac6SDaniel Drake	   - AC adapter status updates
2741e1040ac6SDaniel Drake	   - Battery status updates
27427feda8e9SDaniel Drake
2743a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2744a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2745d8d01a63SDaniel Drake	depends on OLPC && ACPI
2746d8d01a63SDaniel Drake	select POWER_SUPPLY
2747a7f7f624SMasahiro Yamada	help
2748a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2749a0f30f59SDaniel Drake	   - EC-driven system wakeups
2750a0f30f59SDaniel Drake	   - AC adapter status updates
2751a0f30f59SDaniel Drake	   - Battery status updates
2752e279b6c1SSam Ravnborg
2753d4f3e350SEd Wildgooseconfig ALIX
2754d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2755d4f3e350SEd Wildgoose	select GPIOLIB
2756a7f7f624SMasahiro Yamada	help
2757d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2758d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2759d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2760d4f3e350SEd Wildgoose	  get added here.
2761d4f3e350SEd Wildgoose
2762d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2763d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2764d4f3e350SEd Wildgoose
2765d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2766d4f3e350SEd Wildgoose
2767da4e3302SPhilip Prindevilleconfig NET5501
2768da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2769da4e3302SPhilip Prindeville	select GPIOLIB
2770a7f7f624SMasahiro Yamada	help
2771da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2772da4e3302SPhilip Prindeville
27733197059aSPhilip A. Prindevilleconfig GEOS
27743197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27753197059aSPhilip A. Prindeville	select GPIOLIB
27763197059aSPhilip A. Prindeville	depends on DMI
2777a7f7f624SMasahiro Yamada	help
27783197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27793197059aSPhilip A. Prindeville
27807d029125SVivien Didelotconfig TS5500
27817d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27827d029125SVivien Didelot	depends on MELAN
27837d029125SVivien Didelot	select CHECK_SIGNATURE
27847d029125SVivien Didelot	select NEW_LEDS
27857d029125SVivien Didelot	select LEDS_CLASS
2786a7f7f624SMasahiro Yamada	help
27877d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27887d029125SVivien Didelot
2789e279b6c1SSam Ravnborgendif # X86_32
2790e279b6c1SSam Ravnborg
279123ac4ae8SAndreas Herrmannconfig AMD_NB
2792e279b6c1SSam Ravnborg	def_bool y
27930e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2794e279b6c1SSam Ravnborg
2795e279b6c1SSam Ravnborgendmenu
2796e279b6c1SSam Ravnborg
2797e279b6c1SSam Ravnborg
27981572497cSChristoph Hellwigmenu "Binary Emulations"
2799e279b6c1SSam Ravnborg
2800e279b6c1SSam Ravnborgconfig IA32_EMULATION
2801e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2802e279b6c1SSam Ravnborg	depends on X86_64
280339f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2804d1603990SRandy Dunlap	select BINFMT_ELF
280539f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2806a7f7f624SMasahiro Yamada	help
28075fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28085fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28095fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2810e279b6c1SSam Ravnborg
2811e279b6c1SSam Ravnborgconfig IA32_AOUT
2812e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28136b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2814eac61655SBorislav Petkov	depends on BROKEN
2815a7f7f624SMasahiro Yamada	help
2816e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2817e279b6c1SSam Ravnborg
28180bf62763SH. Peter Anvinconfig X86_X32
28196ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28209b54050bSBrian Gerst	depends on X86_64
2821a7f7f624SMasahiro Yamada	help
28225fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28235fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28245fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28255fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28265fd92e65SH. J. Lu
28275fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28285fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28295fd92e65SH. J. Lu	  option set.
28305fd92e65SH. J. Lu
2831953fee1dSIngo Molnarconfig COMPAT_32
2832953fee1dSIngo Molnar	def_bool y
2833953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2834953fee1dSIngo Molnar	select HAVE_UID16
2835953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2836953fee1dSIngo Molnar
2837e279b6c1SSam Ravnborgconfig COMPAT
28383c2362e6SHarvey Harrison	def_bool y
28390bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2840e279b6c1SSam Ravnborg
28413120e25eSJan Beulichif COMPAT
2842e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28433120e25eSJan Beulich	def_bool y
2844e279b6c1SSam Ravnborg
2845e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28463c2362e6SHarvey Harrison	def_bool y
28473120e25eSJan Beulich	depends on SYSVIPC
28483120e25eSJan Beulichendif
2849ee009e4aSDavid Howells
2850e279b6c1SSam Ravnborgendmenu
2851e279b6c1SSam Ravnborg
2852e279b6c1SSam Ravnborg
2853e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2854e5beae16SKeith Packard	def_bool y
2855e5beae16SKeith Packard	depends on X86_32
2856e5beae16SKeith Packard
2857edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28585e8ebd84SJason A. Donenfeld
28595e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2860