xref: /linux/arch/x86/Kconfig (revision b5f06f64e269f9820cd5ad9e9a98afa6c8914b7a)
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
641e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
6591024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
6691024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
67cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
681e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
6991dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
70c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
71fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
72399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7321266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
74b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
756471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7672d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
77316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
786974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
79957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
800f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
810c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8210bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
830ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
84c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8517596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
863010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
870aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
88ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
89d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
90d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
91ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
92ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
93ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9425c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
95c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
967e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9763703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
986471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
996471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10077fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1015e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1023599fe12SThomas Gleixner	select ARCH_STACKWALK
1032c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1046471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1055d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
1066471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
10714df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
108583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
109583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1106471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
111dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1126471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1136471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1142ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
115ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11681c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
117c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
11851c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
1193876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12059612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12138d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
122*b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12310916706SShile Zhang	select BUILDTIME_TABLE_SORT
1246471b825SIngo Molnar	select CLKEVT_I8253
1256471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1266471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1276471b825SIngo Molnar	select DCACHE_WORD_ACCESS
12845471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
12945471cd9SLinus Torvalds	select EDAC_SUPPORT
1306471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1316471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1326471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1336471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
13461dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1356471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
13627d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1376471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1386471b825SIngo Molnar	select GENERIC_IOMAP
139c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1400fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
141ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1426471b825SIngo Molnar	select GENERIC_IRQ_PROBE
143c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1446471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1456471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1462ae27137SSteven Price	select GENERIC_PTDUMP
1476471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1486471b825SIngo Molnar	select GENERIC_STRNCPY_FROM_USER
1496471b825SIngo Molnar	select GENERIC_STRNLEN_USER
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
19503f5781bSWang YanQing	select HAVE_EBPF_JIT
19658340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1976630a8e5SChristoph Hellwig	select HAVE_EISA
1985f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
19967a929e0SChristoph Hellwig	select HAVE_FAST_GUP
200644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2016471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2026471b825SIngo Molnar	select HAVE_FUNCTION_GRAPH_TRACER
2036471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2046b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2050067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2066471b825SIngo Molnar	select HAVE_IDE
2076471b825SIngo Molnar	select HAVE_IOREMAP_PROT
208624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2096471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2106471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2116471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2126471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2136471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2146471b825SIngo Molnar	select HAVE_KERNEL_LZO
2156471b825SIngo Molnar	select HAVE_KERNEL_XZ
216fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2176471b825SIngo Molnar	select HAVE_KPROBES
2186471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
219540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2206471b825SIngo Molnar	select HAVE_KRETPROBES
2216471b825SIngo Molnar	select HAVE_KVM
2226471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2230102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
224ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2259f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
226be37c98dSKalesh Singh	select HAVE_MOVE_PUD
22742a0bb3fSPetr Mladek	select HAVE_NMI
2286471b825SIngo Molnar	select HAVE_OPTPROBES
2296471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2306471b825SIngo Molnar	select HAVE_PERF_EVENTS
231c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23292e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
233eb01d42aSChristoph Hellwig	select HAVE_PCI
234c5e63197SJiri Olsa	select HAVE_PERF_REGS
235c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
236ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
23700998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2386471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2396415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2403c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
241cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
242d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
243c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
244e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2451e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2466ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
247d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2486471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2496471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2507c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2517ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25205736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
253c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
25486596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2552eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
256625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2576471b825SIngo Molnar	select PERF_EVENTS
2583195ef59SPrarit Bhargava	select RTC_LIB
259d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2606471b825SIngo Molnar	select SPARSE_IRQ
26183fe27eaSPranith Kumar	select SRCU
2621e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2636471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26415f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2656471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2666471b825SIngo Molnar	select VIRT_TO_BUS
2673b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2686471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2690c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2709e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2717d8330a5SBalbir Singh
272ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2733120e25eSJan Beulich	def_bool y
2743120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
275ba7e4d13SIngo Molnar
27651b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
27751b26adaSLinus Torvalds	string
27851b26adaSLinus Torvalds	default "elf32-i386" if X86_32
27951b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
28051b26adaSLinus Torvalds
2818d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2823c2362e6SHarvey Harrison	def_bool y
2838d5fffb9SSam Ravnborg
2848d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2853c2362e6SHarvey Harrison	def_bool y
2868d5fffb9SSam Ravnborg
2878d5fffb9SSam Ravnborgconfig MMU
2883c2362e6SHarvey Harrison	def_bool y
2898d5fffb9SSam Ravnborg
2909e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2919e08f57dSDaniel Cashman	default 28 if 64BIT
2929e08f57dSDaniel Cashman	default 8
2939e08f57dSDaniel Cashman
2949e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2959e08f57dSDaniel Cashman	default 32 if 64BIT
2969e08f57dSDaniel Cashman	default 16
2979e08f57dSDaniel Cashman
2989e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2999e08f57dSDaniel Cashman	default 8
3009e08f57dSDaniel Cashman
3019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3029e08f57dSDaniel Cashman	default 16
3039e08f57dSDaniel Cashman
3048d5fffb9SSam Ravnborgconfig SBUS
3058d5fffb9SSam Ravnborg	bool
3068d5fffb9SSam Ravnborg
3078d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3083120e25eSJan Beulich	def_bool y
3093120e25eSJan Beulich	depends on ISA_DMA_API
3108d5fffb9SSam Ravnborg
3118d5fffb9SSam Ravnborgconfig GENERIC_BUG
3123c2362e6SHarvey Harrison	def_bool y
3138d5fffb9SSam Ravnborg	depends on BUG
314b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
315b93a531eSJan Beulich
316b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
317b93a531eSJan Beulich	bool
3188d5fffb9SSam Ravnborg
3198d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3203120e25eSJan Beulich	def_bool y
3213120e25eSJan Beulich	depends on ISA_DMA_API
3228d5fffb9SSam Ravnborg
3231032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3241032c0baSSam Ravnborg	def_bool y
3251032c0baSSam Ravnborg
3269a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3279a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3288d5fffb9SSam Ravnborg
329316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
330316d097cSDave Hansen	def_bool y
331316d097cSDave Hansen
332dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
33389c9c4c5SBrian Gerst	def_bool y
334b32ef636Stravis@sgi.com
33508fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
33608fc4580STejun Heo	def_bool y
33708fc4580STejun Heo
33808fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
33911124411STejun Heo	def_bool y
34011124411STejun Heo
341801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
342801e4062SJohannes Berg	def_bool y
343801e4062SJohannes Berg
344f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
345f4cb5700SJohannes Berg	def_bool y
346f4cb5700SJohannes Berg
34753313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
34853313b2cSSteve Capper	def_bool y
34953313b2cSSteve Capper
3508d5fffb9SSam Ravnborgconfig AUDIT_ARCH
351e0fd24a3SJan Beulich	def_bool y if X86_64
3528d5fffb9SSam Ravnborg
353d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
354d6f2d75aSAndrey Ryabinin	hex
355d6f2d75aSAndrey Ryabinin	depends on KASAN
356d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
357d6f2d75aSAndrey Ryabinin
35869575d38SShane Wangconfig HAVE_INTEL_TXT
35969575d38SShane Wang	def_bool y
3606ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36169575d38SShane Wang
3626b0c3d44SSam Ravnborgconfig X86_32_SMP
3636b0c3d44SSam Ravnborg	def_bool y
3646b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3656b0c3d44SSam Ravnborg
3666b0c3d44SSam Ravnborgconfig X86_64_SMP
3676b0c3d44SSam Ravnborg	def_bool y
3686b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3696b0c3d44SSam Ravnborg
3702b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3712b144498SSrikar Dronamraju	def_bool y
3722b144498SSrikar Dronamraju
373d20642f0SRob Herringconfig FIX_EARLYCON_MEM
374d20642f0SRob Herring	def_bool y
375d20642f0SRob Herring
37694d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
37794d49eb3SKirill A. Shutemov	bool
37894d49eb3SKirill A. Shutemov
37998233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38098233368SKirill A. Shutemov	int
38177ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38298233368SKirill A. Shutemov	default 4 if X86_64
38398233368SKirill A. Shutemov	default 3 if X86_PAE
38498233368SKirill A. Shutemov	default 2
38598233368SKirill A. Shutemov
3862a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3872a61f474SMasahiro Yamada	bool
3882a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3892a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3902a61f474SMasahiro Yamada	help
3912a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3923fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3933fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3942a61f474SMasahiro Yamada
395506f1d07SSam Ravnborgmenu "Processor type and features"
396506f1d07SSam Ravnborg
397506f1d07SSam Ravnborgconfig SMP
398506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
399a7f7f624SMasahiro Yamada	help
400506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4014a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4024a474157SRobert Graffham	  than one CPU, say Y.
403506f1d07SSam Ravnborg
4044a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
405506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
406506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4074a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
408506f1d07SSam Ravnborg	  will run faster if you say N here.
409506f1d07SSam Ravnborg
410506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
411506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
412506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
413506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
414506f1d07SSam Ravnborg
415506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
416506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
417506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
418506f1d07SSam Ravnborg
419cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4204f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
421506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
422506f1d07SSam Ravnborg
423506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
424506f1d07SSam Ravnborg
4259def39beSJosh Triplettconfig X86_FEATURE_NAMES
4269def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4279def39beSJosh Triplett	default y
428a7f7f624SMasahiro Yamada	help
4299def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4309def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4319def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4329def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4339def39beSJosh Triplett
4349def39beSJosh Triplett	  If in doubt, say Y.
4359def39beSJosh Triplett
43606cd9a7dSYinghai Luconfig X86_X2APIC
43706cd9a7dSYinghai Lu	bool "Support x2apic"
43819e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
439a7f7f624SMasahiro Yamada	help
44006cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44106cd9a7dSYinghai Lu
44206cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44306cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44406cd9a7dSYinghai Lu
44506cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44606cd9a7dSYinghai Lu
4476695c85bSYinghai Luconfig X86_MPPARSE
4484590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4497a527688SJan Beulich	default y
4505ab74722SIngo Molnar	depends on X86_LOCAL_APIC
451a7f7f624SMasahiro Yamada	help
4526695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4536695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4546695c85bSYinghai Lu
455ddd70cf9SJun Nakajimaconfig GOLDFISH
456ddd70cf9SJun Nakajima	def_bool y
457ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
458ddd70cf9SJun Nakajima
45976b04384SDavid Woodhouseconfig RETPOLINE
46076b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46176b04384SDavid Woodhouse	default y
46276b04384SDavid Woodhouse	help
46376b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46476b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46576b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46676b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46776b04384SDavid Woodhouse
468e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
469e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4706fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47159fe5a77SThomas Gleixner	select KERNFS
472e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47378e99b4aSFenghua Yu	help
474e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4756fe07ce3SBabu Moger
4766fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4776fe07ce3SBabu Moger	  usage by the CPU.
4786fe07ce3SBabu Moger
4796fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4806fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4816fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4826fe07ce3SBabu Moger
4836fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4846fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4856fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
48678e99b4aSFenghua Yu
48778e99b4aSFenghua Yu	  Say N if unsure.
48878e99b4aSFenghua Yu
4898425091fSRavikiran G Thirumalaiif X86_32
490a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
491a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
492a0d0bb4dSRandy Dunlap	depends on SMP
493a7f7f624SMasahiro Yamada	help
494e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
495a0d0bb4dSRandy Dunlap
496c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
497c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
498c5c606d9SRavikiran G Thirumalai	default y
499a7f7f624SMasahiro Yamada	help
50006ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50106ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50206ac8346SIngo Molnar	  systems out there.)
50306ac8346SIngo Molnar
5048425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5058425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
506cb7b8023SBen Hutchings		Goldfish (Android emulator)
5078425091fSRavikiran G Thirumalai		AMD Elan
5088425091fSRavikiran G Thirumalai		RDC R-321x SoC
5098425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51083125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5113f4110a4SThomas Gleixner		Moorestown MID devices
51206ac8346SIngo Molnar
51306ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51406ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5158425091fSRavikiran G Thirumalaiendif
51606ac8346SIngo Molnar
5178425091fSRavikiran G Thirumalaiif X86_64
5188425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5198425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5208425091fSRavikiran G Thirumalai	default y
521a7f7f624SMasahiro Yamada	help
5228425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5238425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5248425091fSRavikiran G Thirumalai	  systems out there.)
5258425091fSRavikiran G Thirumalai
5268425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5278425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
52844b111b5SSteffen Persvold		Numascale NumaChip
5298425091fSRavikiran G Thirumalai		ScaleMP vSMP
5308425091fSRavikiran G Thirumalai		SGI Ultraviolet
5318425091fSRavikiran G Thirumalai
5328425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5338425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5348425091fSRavikiran G Thirumalaiendif
535c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
536c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
53744b111b5SSteffen Persvoldconfig X86_NUMACHIP
53844b111b5SSteffen Persvold	bool "Numascale NumaChip"
53944b111b5SSteffen Persvold	depends on X86_64
54044b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54144b111b5SSteffen Persvold	depends on NUMA
54244b111b5SSteffen Persvold	depends on SMP
54344b111b5SSteffen Persvold	depends on X86_X2APIC
544f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
545a7f7f624SMasahiro Yamada	help
54644b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
54744b111b5SSteffen Persvold	  enable more than ~168 cores.
54844b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
54903b48632SNick Piggin
5506a48565eSIngo Molnarconfig X86_VSMP
551c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5526276a074SBorislav Petkov	select HYPERVISOR_GUEST
5536a48565eSIngo Molnar	select PARAVIRT
5546a48565eSIngo Molnar	depends on X86_64 && PCI
555c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
556ead91d4bSShai Fultheim	depends on SMP
557a7f7f624SMasahiro Yamada	help
5586a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5596a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5606a48565eSIngo Molnar	  if you have one of these machines.
5616a48565eSIngo Molnar
562c5c606d9SRavikiran G Thirumalaiconfig X86_UV
563c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
564c5c606d9SRavikiran G Thirumalai	depends on X86_64
565c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
56654c28d29SJack Steiner	depends on NUMA
5671ecb4ae5SAndrew Morton	depends on EFI
568c2209ea5SIngo Molnar	depends on KEXEC_CORE
5699d6c26e7SSuresh Siddha	depends on X86_X2APIC
5701222e564SIngo Molnar	depends on PCI
571a7f7f624SMasahiro Yamada	help
572c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
573c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
574c5c606d9SRavikiran G Thirumalai
575c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
576c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
577506f1d07SSam Ravnborg
578ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
579ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
580cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
581a7f7f624SMasahiro Yamada	help
582ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
583ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
584ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
585ddd70cf9SJun Nakajima
586c751e17bSThomas Gleixnerconfig X86_INTEL_CE
587c751e17bSThomas Gleixner	bool "CE4100 TV platform"
588c751e17bSThomas Gleixner	depends on PCI
589c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5906084a6e2SJiang Liu	depends on X86_IO_APIC
591c751e17bSThomas Gleixner	depends on X86_32
592c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59337bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
594da6b737bSSebastian Andrzej Siewior	select OF
595da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
596a7f7f624SMasahiro Yamada	help
597c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
598c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
599c751e17bSThomas Gleixner	  boxes and media devices.
600c751e17bSThomas Gleixner
6014cb9b00fSDavid Cohenconfig X86_INTEL_MID
60243605ef1SAlan Cox	bool "Intel MID platform support"
60343605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
604edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6051ea7c673SAlan Cox	depends on PCI
6063fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6071ea7c673SAlan Cox	depends on X86_IO_APIC
6084cb9b00fSDavid Cohen	select I2C
6097c9c3a1eSAlan Cox	select DW_APB_TIMER
6101ea7c673SAlan Cox	select APB_TIMER
61154b34aa0SMika Westerberg	select INTEL_SCU_PCI
61215a713dfSMika Westerberg	select MFD_INTEL_MSIC
613a7f7f624SMasahiro Yamada	help
6144cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6154cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6164cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6171ea7c673SAlan Cox
6184cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6194cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62043605ef1SAlan Cox
6218bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6228bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6238bbc2a13SBryan O'Donoghue	depends on X86_32
6248bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6258bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6268bbc2a13SBryan O'Donoghue	depends on X86_TSC
6278bbc2a13SBryan O'Donoghue	depends on PCI
6288bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6298bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6308bbc2a13SBryan O'Donoghue	select IOSF_MBI
6318bbc2a13SBryan O'Donoghue	select INTEL_IMR
6329ab6eb51SAndy Shevchenko	select COMMON_CLK
633a7f7f624SMasahiro Yamada	help
6348bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6358bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6368bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6378bbc2a13SBryan O'Donoghue
6383d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6393d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6405962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6413d48aab1SMika Westerberg	select COMMON_CLK
6420f531431SMathias Nyman	select PINCTRL
643eebb3e8dSAndy Shevchenko	select IOSF_MBI
644a7f7f624SMasahiro Yamada	help
6453d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6463d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6470f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6480f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6493d48aab1SMika Westerberg
65092082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65192082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65292082a88SKen Xue	depends on ACPI
65392082a88SKen Xue	select COMMON_CLK
65492082a88SKen Xue	select PINCTRL
655a7f7f624SMasahiro Yamada	help
65692082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
65792082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
65892082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
65992082a88SKen Xue	  implemented under PINCTRL subsystem.
66092082a88SKen Xue
661ced3ce76SDavid E. Boxconfig IOSF_MBI
662ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
663ced3ce76SDavid E. Box	depends on PCI
664a7f7f624SMasahiro Yamada	help
665ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
666ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
667ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
668ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
669ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
670ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
671ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
672ced3ce76SDavid E. Box	   - BayTrail
673ced3ce76SDavid E. Box	   - Braswell
674ced3ce76SDavid E. Box	   - Quark
675ced3ce76SDavid E. Box
676ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
677ced3ce76SDavid E. Box
678ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
679ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
680ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
681a7f7f624SMasahiro Yamada	help
682ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
683ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
684ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
685ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
686ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
687ed2226bdSDavid E. Box	  device they want to access.
688ed2226bdSDavid E. Box
689ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
690ed2226bdSDavid E. Box
691c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
692c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
693506f1d07SSam Ravnborg	depends on X86_32
694c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
695c5c606d9SRavikiran G Thirumalai	select M486
696c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
697a7f7f624SMasahiro Yamada	help
698c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
699c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
700c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
701c5c606d9SRavikiran G Thirumalai
702e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7039c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7049c398017SIngo Molnar	depends on X86_32 && SMP
705c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
706a7f7f624SMasahiro Yamada	help
707b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
708b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
709b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
710b5660ba7SH. Peter Anvin	  one and will fallback to default.
711d49c4288SYinghai Lu
712c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
713d49c4288SYinghai Lu
714d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7156fc108a0SJan Beulich	def_bool y
716d949f36fSLinus Torvalds	# MCE code calls memory_failure():
717d949f36fSLinus Torvalds	depends on X86_MCE
718d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
719d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
720d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
721d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
722d949f36fSLinus Torvalds
72383125a3aSAlessandro Rubiniconfig STA2X11
72483125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72583125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
72683125a3aSAlessandro Rubini	select SWIOTLB
72783125a3aSAlessandro Rubini	select MFD_STA2X11
7280145071bSLinus Walleij	select GPIOLIB
729a7f7f624SMasahiro Yamada	help
73083125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73183125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73283125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73383125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73483125a3aSAlessandro Rubini	  standard PC machines.
73583125a3aSAlessandro Rubini
73682148d1dSShérabconfig X86_32_IRIS
73782148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
73882148d1dSShérab	depends on X86_32
739a7f7f624SMasahiro Yamada	help
74082148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74182148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74282148d1dSShérab	  needed to do so, which is what this module does at
74382148d1dSShérab	  kernel shutdown.
74482148d1dSShérab
74582148d1dSShérab	  This is only for Iris machines from EuroBraille.
74682148d1dSShérab
74782148d1dSShérab	  If unused, say N.
74882148d1dSShérab
749ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7503c2362e6SHarvey Harrison	def_bool y
7513c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
752a87d0914SKen Chen	depends on X86
753a7f7f624SMasahiro Yamada	help
754506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
755506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
756506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
757506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
758506f1d07SSam Ravnborg
759506f1d07SSam Ravnborg	  If in doubt, say "Y".
760506f1d07SSam Ravnborg
7616276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7626276a074SBorislav Petkov	bool "Linux guest support"
763a7f7f624SMasahiro Yamada	help
7646276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7656276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7666276a074SBorislav Petkov	  setup.
767506f1d07SSam Ravnborg
7686276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7696276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
770506f1d07SSam Ravnborg
7716276a074SBorislav Petkovif HYPERVISOR_GUEST
772506f1d07SSam Ravnborg
773e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
774e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
775a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
776a7f7f624SMasahiro Yamada	help
777e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
778e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
779e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
780e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
781e61bd94aSEduardo Pereira Habkost
782c00a280aSJuergen Grossconfig PARAVIRT_XXL
783c00a280aSJuergen Gross	bool
784c00a280aSJuergen Gross
7856276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7866276a074SBorislav Petkov	bool "paravirt-ops debugging"
7876276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
788a7f7f624SMasahiro Yamada	help
7896276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7906276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7916276a074SBorislav Petkov
792b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
793b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7946ea30386SKees Cook	depends on PARAVIRT && SMP
795a7f7f624SMasahiro Yamada	help
796b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
797b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
798b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
799b4ecc126SJeremy Fitzhardinge
8004c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8014c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
802b4ecc126SJeremy Fitzhardinge
8034c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
804b4ecc126SJeremy Fitzhardinge
805ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
806ecca2502SZhao Yakui	def_bool n
807ecca2502SZhao Yakui
8086276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8096276a074SBorislav Petkov
8106276a074SBorislav Petkovconfig KVM_GUEST
8116276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8126276a074SBorislav Petkov	depends on PARAVIRT
8136276a074SBorislav Petkov	select PARAVIRT_CLOCK
814a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
815b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8166276a074SBorislav Petkov	default y
817a7f7f624SMasahiro Yamada	help
8186276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8196276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8206276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8216276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8226276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8236276a074SBorislav Petkov
824a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
825a1c4423bSMarcelo Tosatti	def_bool n
826a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
827a1c4423bSMarcelo Tosatti	help
828a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
829a1c4423bSMarcelo Tosatti
8307733607fSMaran Wilsonconfig PVH
8317733607fSMaran Wilson	bool "Support for running PVH guests"
832a7f7f624SMasahiro Yamada	help
8337733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8347733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8357733607fSMaran Wilson
8366276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8376276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8386276a074SBorislav Petkov	depends on PARAVIRT
839a7f7f624SMasahiro Yamada	help
8406276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8416276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8426276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8436276a074SBorislav Petkov	  that, there can be a small performance impact.
8446276a074SBorislav Petkov
8456276a074SBorislav Petkov	  If in doubt, say N here.
8466276a074SBorislav Petkov
8477af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8487af192c9SGerd Hoffmann	bool
8497af192c9SGerd Hoffmann
8504a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8514a362601SJan Kiszka	bool "Jailhouse non-root cell support"
852abde587bSArnd Bergmann	depends on X86_64 && PCI
85387e65d05SJan Kiszka	select X86_PM_TIMER
854a7f7f624SMasahiro Yamada	help
8554a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8564a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8574a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8584a362601SJan Kiszka
859ec7972c9SZhao Yakuiconfig ACRN_GUEST
860ec7972c9SZhao Yakui	bool "ACRN Guest support"
861ec7972c9SZhao Yakui	depends on X86_64
862498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
863ec7972c9SZhao Yakui	help
864ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
865ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
866ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
867ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
868ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
869ec7972c9SZhao Yakui
8706276a074SBorislav Petkovendif #HYPERVISOR_GUEST
87197349135SJeremy Fitzhardinge
872506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
873506f1d07SSam Ravnborg
874506f1d07SSam Ravnborgconfig HPET_TIMER
8753c2362e6SHarvey Harrison	def_bool X86_64
876506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
877a7f7f624SMasahiro Yamada	help
878506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
879506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
880506f1d07SSam Ravnborg	  present.
881506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
882506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
883506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8844e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8854e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
886506f1d07SSam Ravnborg
887506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
888506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
889506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
890506f1d07SSam Ravnborg
891506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
892506f1d07SSam Ravnborg
893506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8943c2362e6SHarvey Harrison	def_bool y
8953228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
896506f1d07SSam Ravnborg
8976a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
898506f1d07SSam Ravnborg# The code disables itself when not needed.
8997ae9392cSThomas Petazzoniconfig DMI
9007ae9392cSThomas Petazzoni	default y
901cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9026a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
903a7f7f624SMasahiro Yamada	help
9047ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9057ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9067ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9077ae9392cSThomas Petazzoni	  BIOS code.
9087ae9392cSThomas Petazzoni
909506f1d07SSam Ravnborgconfig GART_IOMMU
91038901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9112f9237d4SChristoph Hellwig	select DMA_OPS
912a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
913506f1d07SSam Ravnborg	select SWIOTLB
91423ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
915a7f7f624SMasahiro Yamada	help
916ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
917ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
918ced3c42cSIngo Molnar
919ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
920ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
921ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
924ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
925ced3c42cSIngo Molnar
926ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
927ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
928ced3c42cSIngo Molnar	  32-bit limited device.
929ced3c42cSIngo Molnar
930ced3c42cSIngo Molnar	  If unsure, say Y.
931506f1d07SSam Ravnborg
9321184dc2fSMike Travisconfig MAXSMP
933ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9346ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93536f5101aSMike Travis	select CPUMASK_OFFSTACK
936a7f7f624SMasahiro Yamada	help
937ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9381184dc2fSMike Travis	  If unsure, say N.
939506f1d07SSam Ravnborg
940aec6487eSIngo Molnar#
941aec6487eSIngo Molnar# The maximum number of CPUs supported:
942aec6487eSIngo Molnar#
943aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
944aec6487eSIngo Molnar# and which can be configured interactively in the
945aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
948aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
949aec6487eSIngo Molnar#
950aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
951aec6487eSIngo Molnar#   interactive configuration. )
952aec6487eSIngo Molnar#
953a0d0bb4dSRandy Dunlap
954aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
955a0d0bb4dSRandy Dunlap	int
956aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
957a0d0bb4dSRandy Dunlap	default    1 if !SMP
958a0d0bb4dSRandy Dunlap	default    2
959a0d0bb4dSRandy Dunlap
960aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
961a0d0bb4dSRandy Dunlap	int
962a0d0bb4dSRandy Dunlap	depends on X86_32
963aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
964aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
965a0d0bb4dSRandy Dunlap	default    1 if !SMP
966a0d0bb4dSRandy Dunlap
967aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
968a0d0bb4dSRandy Dunlap	int
969a0d0bb4dSRandy Dunlap	depends on X86_64
9701edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9711edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
972a0d0bb4dSRandy Dunlap	default    1 if !SMP
973aec6487eSIngo Molnar
974aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
975aec6487eSIngo Molnar	int
976aec6487eSIngo Molnar	depends on X86_32
977aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
978aec6487eSIngo Molnar	default    8 if  SMP
979aec6487eSIngo Molnar	default    1 if !SMP
980aec6487eSIngo Molnar
981aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
982aec6487eSIngo Molnar	int
983aec6487eSIngo Molnar	depends on X86_64
984a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
985a0d0bb4dSRandy Dunlap	default   64 if  SMP
986aec6487eSIngo Molnar	default    1 if !SMP
987a0d0bb4dSRandy Dunlap
988506f1d07SSam Ravnborgconfig NR_CPUS
98936f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
990aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
991aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
992a7f7f624SMasahiro Yamada	help
993506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
994bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
995cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
996506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
997506f1d07SSam Ravnborg
998aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
999aec6487eSIngo Molnar	  to the kernel image.
1000506f1d07SSam Ravnborg
1001506f1d07SSam Ravnborgconfig SCHED_SMT
1002dbe73364SThomas Gleixner	def_bool y if SMP
1003506f1d07SSam Ravnborg
1004506f1d07SSam Ravnborgconfig SCHED_MC
10053c2362e6SHarvey Harrison	def_bool y
10063c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1007c8e56d20SBorislav Petkov	depends on SMP
1008a7f7f624SMasahiro Yamada	help
1009506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1010506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1011506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1012506f1d07SSam Ravnborg
1013de966cf4STim Chenconfig SCHED_MC_PRIO
1014de966cf4STim Chen	bool "CPU core priorities scheduler support"
10150a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10160a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10170a21fc12SIngo Molnar	select CPU_FREQ
1018de966cf4STim Chen	default y
1019a7f7f624SMasahiro Yamada	help
1020de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1021de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1022de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1023de966cf4STim Chen	  single threaded workloads) than others.
1024de966cf4STim Chen
1025de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1026de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1027de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1028de966cf4STim Chen	  overall system performance can be achieved.
1029de966cf4STim Chen
1030de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1031de966cf4STim Chen
1032de966cf4STim Chen	  If unsure say Y here.
10335e76b2abSTim Chen
103430b8b006SThomas Gleixnerconfig UP_LATE_INIT
103530b8b006SThomas Gleixner	def_bool y
1036ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
103730b8b006SThomas Gleixner
1038506f1d07SSam Ravnborgconfig X86_UP_APIC
103950849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104050849eefSJan Beulich	default PCI_MSI
104138a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1042a7f7f624SMasahiro Yamada	help
1043506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1044506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1045506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1046506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1047506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1048506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1049506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1050506f1d07SSam Ravnborg	  lockups.
1051506f1d07SSam Ravnborg
1052506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1053506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1054506f1d07SSam Ravnborg	depends on X86_UP_APIC
1055a7f7f624SMasahiro Yamada	help
1056506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1057506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1058506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1059506f1d07SSam Ravnborg
1060506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1061506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1062506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10653c2362e6SHarvey Harrison	def_bool y
10660dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1067b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
106852f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1069506f1d07SSam Ravnborg
1070506f1d07SSam Ravnborgconfig X86_IO_APIC
1071b1da1e71SJan Beulich	def_bool y
1072b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1073506f1d07SSam Ravnborg
107441b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107541b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
107641b9eb26SStefan Assmann	depends on X86_IO_APIC
1077a7f7f624SMasahiro Yamada	help
107841b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
107941b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108041b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108141b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108241b9eb26SStefan Assmann
108341b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108441b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108541b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
108641b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
108741b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
108841b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
108941b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109041b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109141b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109241b9eb26SStefan Assmann	  down (vital) interrupt lines.
109341b9eb26SStefan Assmann
109441b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109541b9eb26SStefan Assmann	  increased on these systems.
109641b9eb26SStefan Assmann
1097506f1d07SSam Ravnborgconfig X86_MCE
1098bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1099648ed940SChen, Gong	select GENERIC_ALLOCATOR
1100e57dbaf7SBorislav Petkov	default y
1101a7f7f624SMasahiro Yamada	help
1102bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1103bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1104506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1105bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11064efc0670SAndi Kleen
11075de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11085de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11095de97c9fSTony Luck	depends on X86_MCE
1110a7f7f624SMasahiro Yamada	help
11115de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11125de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11135de97c9fSTony Luck	  rasdaemon solution.
11145de97c9fSTony Luck
1115506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11163c2362e6SHarvey Harrison	def_bool y
11173c2362e6SHarvey Harrison	prompt "Intel MCE features"
1118c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1119a7f7f624SMasahiro Yamada	help
1120506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1121506f1d07SSam Ravnborg	   the thermal monitor.
1122506f1d07SSam Ravnborg
1123506f1d07SSam Ravnborgconfig X86_MCE_AMD
11243c2362e6SHarvey Harrison	def_bool y
11253c2362e6SHarvey Harrison	prompt "AMD MCE features"
1126f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1127a7f7f624SMasahiro Yamada	help
1128506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1129506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1130506f1d07SSam Ravnborg
11314efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11326fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1133c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1134a7f7f624SMasahiro Yamada	help
11354efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11365065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11374efc0670SAndi Kleen	  line.
11384efc0670SAndi Kleen
1139b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1140b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11416fc108a0SJan Beulich	def_bool y
1142b2762686SAndi Kleen
1143ea149b36SAndi Kleenconfig X86_MCE_INJECT
1144bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1145ea149b36SAndi Kleen	tristate "Machine check injector support"
1146a7f7f624SMasahiro Yamada	help
1147ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1148ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1149ea149b36SAndi Kleen	  QA it is safe to say n.
1150ea149b36SAndi Kleen
115107dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1152e633c65aSKan Liang
11535aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11541e642812SIngo Molnar	bool "Legacy VM86 support"
1155506f1d07SSam Ravnborg	depends on X86_32
1156a7f7f624SMasahiro Yamada	help
11575aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11585aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11595aef51c3SAndy Lutomirski
11605aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11615aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11625aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11635aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11645aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11651e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11661e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11671e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11681e642812SIngo Molnar	  enable this option.
11695aef51c3SAndy Lutomirski
11701e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11711e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11721e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11731e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11745aef51c3SAndy Lutomirski
11751e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11761e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11775aef51c3SAndy Lutomirski
11781e642812SIngo Molnar	  If unsure, say N here.
11795aef51c3SAndy Lutomirski
11805aef51c3SAndy Lutomirskiconfig VM86
11815aef51c3SAndy Lutomirski	bool
11825aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
118334273f41SH. Peter Anvin
118434273f41SH. Peter Anvinconfig X86_16BIT
118534273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
118634273f41SH. Peter Anvin	default y
1187a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1188a7f7f624SMasahiro Yamada	help
118934273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119034273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119134273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
119234273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
119334273f41SH. Peter Anvin
119434273f41SH. Peter Anvinconfig X86_ESPFIX32
119534273f41SH. Peter Anvin	def_bool y
119634273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1197506f1d07SSam Ravnborg
1198197725deSH. Peter Anvinconfig X86_ESPFIX64
1199197725deSH. Peter Anvin	def_bool y
120034273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1201506f1d07SSam Ravnborg
12021ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12031ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12041ad83c85SAndy Lutomirski	default y
12051ad83c85SAndy Lutomirski	depends on X86_64
1206a7f7f624SMasahiro Yamada	help
12071ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12081ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12091ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12101ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12111ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12121ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12131ad83c85SAndy Lutomirski
12141ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12151ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12161ad83c85SAndy Lutomirski
12171ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12181ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12191ad83c85SAndy Lutomirski
1220111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1221111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1222a24ca997SThomas Gleixner	default y
1223a7f7f624SMasahiro Yamada	help
1224111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1225111e7b15SThomas Gleixner	  for legacy applications.
1226111e7b15SThomas Gleixner
1227c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1228c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1229c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1230c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1231c8137aceSThomas Gleixner	  modules.
1232c8137aceSThomas Gleixner
1233c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1234c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1235a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1236a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1237c8137aceSThomas Gleixner
1238506f1d07SSam Ravnborgconfig TOSHIBA
1239506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1240506f1d07SSam Ravnborg	depends on X86_32
1241a7f7f624SMasahiro Yamada	help
1242506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1243506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1244506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1245506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1246506f1d07SSam Ravnborg
1247506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1248506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1249506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1250506f1d07SSam Ravnborg
1251506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1252506f1d07SSam Ravnborg	  Say N otherwise.
1253506f1d07SSam Ravnborg
1254506f1d07SSam Ravnborgconfig I8K
1255039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1256949a9d70SJean Delvare	select HWMON
1257039ae585SPali Rohár	select SENSORS_DELL_SMM
1258a7f7f624SMasahiro Yamada	help
1259039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1260039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1261039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1262039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1263039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1264039ae585SPali Rohár	  needed userspace package i8kutils.
1265506f1d07SSam Ravnborg
1266039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1267039ae585SPali Rohár	  use userspace package i8kutils.
1268506f1d07SSam Ravnborg	  Say N otherwise.
1269506f1d07SSam Ravnborg
1270506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12719ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12729ba16087SJan Beulich	depends on X86_32
1273a7f7f624SMasahiro Yamada	help
1274506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1275506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1276506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1277506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1278506f1d07SSam Ravnborg	  system.
1279506f1d07SSam Ravnborg
1280506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12815e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1282506f1d07SSam Ravnborg
1283506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1284506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1285506f1d07SSam Ravnborg	  Say N otherwise.
1286506f1d07SSam Ravnborg
1287506f1d07SSam Ravnborgconfig MICROCODE
12889a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12899a2bc335SBorislav Petkov	default y
129080030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1291a7f7f624SMasahiro Yamada	help
1292506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12935f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12945f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12955f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
12965f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
12975f9c01aaSBorislav Petkov	  the Linux kernel.
1298506f1d07SSam Ravnborg
12995f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1300cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13015f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13025f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1303506f1d07SSam Ravnborg
1304c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1305c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1306c508c46eSBenjamin Gilbert	  config option.
1307506f1d07SSam Ravnborg
13088d86f390SPeter Orubaconfig MICROCODE_INTEL
1309e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13108d86f390SPeter Oruba	depends on MICROCODE
13118d86f390SPeter Oruba	default MICROCODE
1312a7f7f624SMasahiro Yamada	help
13138d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13148d86f390SPeter Oruba	  processors.
13158d86f390SPeter Oruba
1316b8989db9SAlan	  For the current Intel microcode data package go to
1317b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1318b8989db9SAlan	  'Linux Processor Microcode Data File'.
13198d86f390SPeter Oruba
132080cc9f10SPeter Orubaconfig MICROCODE_AMD
1321e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132280cc9f10SPeter Oruba	depends on MICROCODE
1323a7f7f624SMasahiro Yamada	help
132480cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
132580cc9f10SPeter Oruba	  processors will be enabled.
132680cc9f10SPeter Oruba
1327506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1328c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1329c02f48e0SBorislav Petkov	default n
1330506f1d07SSam Ravnborg	depends on MICROCODE
1331a7f7f624SMasahiro Yamada	help
1332c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1333c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1334c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1335c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1336c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1337cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1338506f1d07SSam Ravnborg
1339506f1d07SSam Ravnborgconfig X86_MSR
1340506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1341a7f7f624SMasahiro Yamada	help
1342506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1343506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1344506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1345506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1346506f1d07SSam Ravnborg	  systems.
1347506f1d07SSam Ravnborg
1348506f1d07SSam Ravnborgconfig X86_CPUID
1349506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1350a7f7f624SMasahiro Yamada	help
1351506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1352506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1353506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1354506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1355506f1d07SSam Ravnborg
1356506f1d07SSam Ravnborgchoice
1357506f1d07SSam Ravnborg	prompt "High Memory Support"
13586fc108a0SJan Beulich	default HIGHMEM4G
1359506f1d07SSam Ravnborg	depends on X86_32
1360506f1d07SSam Ravnborg
1361506f1d07SSam Ravnborgconfig NOHIGHMEM
1362506f1d07SSam Ravnborg	bool "off"
1363a7f7f624SMasahiro Yamada	help
1364506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1365506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1366506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1367506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1368506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1369506f1d07SSam Ravnborg	  "high memory".
1370506f1d07SSam Ravnborg
1371506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1372506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1373506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1374506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1375506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1376506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1377506f1d07SSam Ravnborg	  possible.
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1380506f1d07SSam Ravnborg	  answer "4GB" here.
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1383506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1384506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1385506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1386506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1387506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1388506f1d07SSam Ravnborg
1389506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1390506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1391506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1392506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1393506f1d07SSam Ravnborg	  kernel at boot time.)
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborg	  If unsure, say "off".
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborgconfig HIGHMEM4G
1398506f1d07SSam Ravnborg	bool "4GB"
1399a7f7f624SMasahiro Yamada	help
1400506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1401506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1402506f1d07SSam Ravnborg
1403506f1d07SSam Ravnborgconfig HIGHMEM64G
1404506f1d07SSam Ravnborg	bool "64GB"
14050ef3439cSMaciej W. Rozycki	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1406506f1d07SSam Ravnborg	select X86_PAE
1407a7f7f624SMasahiro Yamada	help
1408506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1409506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborgendchoice
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborgchoice
14146a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1415506f1d07SSam Ravnborg	default VMSPLIT_3G
1416506f1d07SSam Ravnborg	depends on X86_32
1417a7f7f624SMasahiro Yamada	help
1418506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1419506f1d07SSam Ravnborg
1420506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1421506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1422506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1423506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1424506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1425506f1d07SSam Ravnborg	  available to user programs, making the address space there
1426506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1427506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1428506f1d07SSam Ravnborg	  kernel modules.
1429506f1d07SSam Ravnborg
1430506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1431506f1d07SSam Ravnborg	  option alone!
1432506f1d07SSam Ravnborg
1433506f1d07SSam Ravnborg	config VMSPLIT_3G
1434506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1435506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1436506f1d07SSam Ravnborg		depends on !X86_PAE
1437506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1438506f1d07SSam Ravnborg	config VMSPLIT_2G
1439506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1440506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1441506f1d07SSam Ravnborg		depends on !X86_PAE
1442506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1443506f1d07SSam Ravnborg	config VMSPLIT_1G
1444506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1445506f1d07SSam Ravnborgendchoice
1446506f1d07SSam Ravnborg
1447506f1d07SSam Ravnborgconfig PAGE_OFFSET
1448506f1d07SSam Ravnborg	hex
1449506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1450506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1451506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1452506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1453506f1d07SSam Ravnborg	default 0xC0000000
1454506f1d07SSam Ravnborg	depends on X86_32
1455506f1d07SSam Ravnborg
1456506f1d07SSam Ravnborgconfig HIGHMEM
14573c2362e6SHarvey Harrison	def_bool y
1458506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1459506f1d07SSam Ravnborg
1460506f1d07SSam Ravnborgconfig X86_PAE
14619ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1462506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1463d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14649d99c712SChristian Melki	select SWIOTLB
1465a7f7f624SMasahiro Yamada	help
1466506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1467506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1468506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1469506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1470506f1d07SSam Ravnborg
147177ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147277ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
147318ec1eafSKirill A. Shutemov	default y
1474eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1475162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
147677ef56e4SKirill A. Shutemov	depends on X86_64
1477a7f7f624SMasahiro Yamada	help
147877ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
147977ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148077ef56e4SKirill A. Shutemov	  physical address space.
148177ef56e4SKirill A. Shutemov
148277ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
148377ef56e4SKirill A. Shutemov
14846657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14856657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
148677ef56e4SKirill A. Shutemov
1487cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
148877ef56e4SKirill A. Shutemov	  information.
148977ef56e4SKirill A. Shutemov
149077ef56e4SKirill A. Shutemov	  Say N if unsure.
149177ef56e4SKirill A. Shutemov
149210971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1493e5008abeSLuis R. Rodriguez	def_bool y
14942e1da13fSVlastimil Babka	depends on X86_64
1495a7f7f624SMasahiro Yamada	help
149610971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
149710971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
149810971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
149910971ab2SIngo Molnar	  that we have them enabled.
15009e899816SNick Piggin
15015c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15025c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15035c280cf6SThomas Gleixner	depends on DEBUG_FS
1504a7f7f624SMasahiro Yamada	help
1505b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1506a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15075c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15085c280cf6SThomas Gleixner
15097744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15107744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15117744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
151282fef0adSDavid Rientjes	select DMA_COHERENT_POOL
151394d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1514ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15159087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1516597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
151722916417STom Lendacky	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1518a7f7f624SMasahiro Yamada	help
15197744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15207744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15217744ccdbSTom Lendacky	  Encryption (SME).
15227744ccdbSTom Lendacky
15237744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15247744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15257744ccdbSTom Lendacky	default y
15267744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1527a7f7f624SMasahiro Yamada	help
15287744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15297744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15307744ccdbSTom Lendacky
15317744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15327744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15337744ccdbSTom Lendacky
15347744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15357744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15367744ccdbSTom Lendacky
1537506f1d07SSam Ravnborg# Common NUMA Features
1538506f1d07SSam Ravnborgconfig NUMA
1539e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1540506f1d07SSam Ravnborg	depends on SMP
1541b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1542b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1543a7f7f624SMasahiro Yamada	help
1544e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1545fd51b2d7SKOSAKI Motohiro
1546506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1547506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1548506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1549506f1d07SSam Ravnborg
1550c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1551fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1552fd51b2d7SKOSAKI Motohiro
1553b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15547cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1555fd51b2d7SKOSAKI Motohiro
1556fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1557506f1d07SSam Ravnborg
1558eec1d4faSHans Rosenfeldconfig AMD_NUMA
15593c2362e6SHarvey Harrison	def_bool y
15603c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15615da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1562a7f7f624SMasahiro Yamada	help
1563eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1564eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1565eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1566eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1567eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1568506f1d07SSam Ravnborg
1569506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15703c2362e6SHarvey Harrison	def_bool y
15713c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1572506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1573506f1d07SSam Ravnborg	select ACPI_NUMA
1574a7f7f624SMasahiro Yamada	help
1575506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1576506f1d07SSam Ravnborg
1577506f1d07SSam Ravnborgconfig NUMA_EMU
1578506f1d07SSam Ravnborg	bool "NUMA emulation"
15791b7e03efSTejun Heo	depends on NUMA
1580a7f7f624SMasahiro Yamada	help
1581506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1582506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1583506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1584506f1d07SSam Ravnborg
1585506f1d07SSam Ravnborgconfig NODES_SHIFT
1586d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
158751591e31SDavid Rientjes	range 1 10
158851591e31SDavid Rientjes	default "10" if MAXSMP
1589506f1d07SSam Ravnborg	default "6" if X86_64
1590506f1d07SSam Ravnborg	default "3"
1591a9ee6cf5SMike Rapoport	depends on NUMA
1592a7f7f624SMasahiro Yamada	help
15931184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1594692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1595506f1d07SSam Ravnborg
1596506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1597506f1d07SSam Ravnborg	def_bool y
15983b16651fSTejun Heo	depends on X86_32 && !NUMA
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1601506f1d07SSam Ravnborg	def_bool y
16026ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1603506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1604506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1605506f1d07SSam Ravnborg
16063b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16076ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16083b16651fSTejun Heo
1609506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1610506f1d07SSam Ravnborg	def_bool y
1611b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1612506f1d07SSam Ravnborg
1613506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1614a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16153120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1616a0842b70SToshi Kani	help
1617a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1618cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1619a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1620506f1d07SSam Ravnborg
16213b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16223b16651fSTejun Heo	def_bool y
16233b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16243b16651fSTejun Heo
1625a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1626a29815a3SAvi Kivity	hex
1627a29815a3SAvi Kivity	default 0 if X86_32
1628a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1629a29815a3SAvi Kivity
16307a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16317a67832cSDan Williams	bool
16327a67832cSDan Williams
1633ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16347a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16359f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16369f53f9faSDan Williams	depends on BLK_DEV
16377a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16387b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16399f53f9faSDan Williams	select LIBNVDIMM
1640ec776ef6SChristoph Hellwig	help
1641ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1642ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1643ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1644ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1645ec776ef6SChristoph Hellwig
1646ec776ef6SChristoph Hellwig	  Say Y if unsure.
1647ec776ef6SChristoph Hellwig
1648506f1d07SSam Ravnborgconfig HIGHPTE
1649506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16506fc108a0SJan Beulich	depends on HIGHMEM
1651a7f7f624SMasahiro Yamada	help
1652506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1653506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1654506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1655506f1d07SSam Ravnborg	  entries in high memory.
1656506f1d07SSam Ravnborg
16579f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16589f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1659a7f7f624SMasahiro Yamada	help
16609f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16619f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16629f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16639f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16649f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16659f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16669f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16678c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16689f077871SJeremy Fitzhardinge
16699f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16709f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16719f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16729f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16739f077871SJeremy Fitzhardinge
16749f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16759f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16769f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16779f077871SJeremy Fitzhardinge	  memory.
16789f077871SJeremy Fitzhardinge
1679c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1680c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1681c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1682c885df50SJeremy Fitzhardinge	default y
1683a7f7f624SMasahiro Yamada	help
1684c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1685c885df50SJeremy Fitzhardinge	  on or off.
1686c885df50SJeremy Fitzhardinge
1687506f1d07SSam Ravnborgconfig MATH_EMULATION
1688506f1d07SSam Ravnborg	bool
1689a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
169087d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1691a7f7f624SMasahiro Yamada	help
1692506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1693506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1694506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1695506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1696506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1697506f1d07SSam Ravnborg	  coprocessor or this emulation.
1698506f1d07SSam Ravnborg
1699506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1700506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1701506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1702506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1703506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1704506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1705506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1706506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1707506f1d07SSam Ravnborg
1708506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1709506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1710506f1d07SSam Ravnborg
1711506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1712506f1d07SSam Ravnborg	  kernel, it won't hurt.
1713506f1d07SSam Ravnborg
1714506f1d07SSam Ravnborgconfig MTRR
17156fc108a0SJan Beulich	def_bool y
17166a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1717a7f7f624SMasahiro Yamada	help
1718506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1719506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1720506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1721506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1722506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1723506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1724506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1725506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1726506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1729506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1730506f1d07SSam Ravnborg	  as well:
1731506f1d07SSam Ravnborg
1732506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1733506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1734506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1735506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1736506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1737506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1738506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1741506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1742506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1745506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1746506f1d07SSam Ravnborg
1747cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1748506f1d07SSam Ravnborg
174995ffa243SYinghai Luconfig MTRR_SANITIZER
17502ffb3501SYinghai Lu	def_bool y
175195ffa243SYinghai Lu	prompt "MTRR cleanup support"
175295ffa243SYinghai Lu	depends on MTRR
1753a7f7f624SMasahiro Yamada	help
1754aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1755aba3728cSThomas Gleixner	  add writeback entries.
175695ffa243SYinghai Lu
1757aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1758692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1759aba3728cSThomas Gleixner	  mtrr_chunk_size.
176095ffa243SYinghai Lu
17612ffb3501SYinghai Lu	  If unsure, say Y.
176295ffa243SYinghai Lu
176395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1764f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1765f5098d62SYinghai Lu	range 0 1
1766f5098d62SYinghai Lu	default "0"
176795ffa243SYinghai Lu	depends on MTRR_SANITIZER
1768a7f7f624SMasahiro Yamada	help
1769f5098d62SYinghai Lu	  Enable mtrr cleanup default value
177095ffa243SYinghai Lu
177112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
177212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
177312031a62SYinghai Lu	range 0 7
177412031a62SYinghai Lu	default "1"
177512031a62SYinghai Lu	depends on MTRR_SANITIZER
1776a7f7f624SMasahiro Yamada	help
177712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1778aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
177912031a62SYinghai Lu
17802e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17816fc108a0SJan Beulich	def_bool y
17826a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17832a8a2719SIngo Molnar	depends on MTRR
1784a7f7f624SMasahiro Yamada	help
17852e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1786042b78e4SVenki Pallipadi
17872e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
17882e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
17892e5d9c85Svenkatesh.pallipadi@intel.com
17902e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1791042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
17922e5d9c85Svenkatesh.pallipadi@intel.com
17932e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
17942e5d9c85Svenkatesh.pallipadi@intel.com
179546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
179646cf98cdSVenkatesh Pallipadi	def_bool y
179746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
179846cf98cdSVenkatesh Pallipadi
1799628c6246SH. Peter Anvinconfig ARCH_RANDOM
1800628c6246SH. Peter Anvin	def_bool y
1801628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1802a7f7f624SMasahiro Yamada	help
1803628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1804628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1805628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1806628c6246SH. Peter Anvin	  secure hardware random number generator.
1807628c6246SH. Peter Anvin
180851ae4a2dSH. Peter Anvinconfig X86_SMAP
180951ae4a2dSH. Peter Anvin	def_bool y
181051ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1811a7f7f624SMasahiro Yamada	help
181251ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
181351ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
181451ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
181551ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
181651ae4a2dSH. Peter Anvin
181751ae4a2dSH. Peter Anvin	  If unsure, say Y.
181851ae4a2dSH. Peter Anvin
1819b971880fSBabu Mogerconfig X86_UMIP
1820796ebc81SRicardo Neri	def_bool y
1821b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1822a7f7f624SMasahiro Yamada	help
1823b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1824b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1825b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1826b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1827b971880fSBabu Moger	  information about the hardware state.
1828796ebc81SRicardo Neri
1829796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1830796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1831796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1832796ebc81SRicardo Neri	  results are dummy.
1833aa35f896SRicardo Neri
183435e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
183538f3e775SBabu Moger	prompt "Memory Protection Keys"
183635e97790SDave Hansen	def_bool y
1837284244a9SDave Hansen	# Note: only available in 64-bit mode
183838f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
183952c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
184052c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1841a7f7f624SMasahiro Yamada	help
1842284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1843284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1844284244a9SDave Hansen	  page tables when an application changes protection domains.
1845284244a9SDave Hansen
18461eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1847284244a9SDave Hansen
1848284244a9SDave Hansen	  If unsure, say y.
184935e97790SDave Hansen
1850db616173SMichal Hockochoice
1851db616173SMichal Hocko	prompt "TSX enable mode"
1852db616173SMichal Hocko	depends on CPU_SUP_INTEL
1853db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1854db616173SMichal Hocko	help
1855db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1856db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1857db616173SMichal Hocko	  can lead to a noticeable performance boost.
1858db616173SMichal Hocko
1859db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1860db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1861db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1862db616173SMichal Hocko
1863db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1864db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1865db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1866db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1867db616173SMichal Hocko	  for the particular machine.
1868db616173SMichal Hocko
1869db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1870db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1871db616173SMichal Hocko	  details.
1872db616173SMichal Hocko
1873db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1874db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1875db616173SMichal Hocko	  relevant.
1876db616173SMichal Hocko
1877db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1878db616173SMichal Hocko	bool "off"
1879db616173SMichal Hocko	help
1880db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1881db616173SMichal Hocko
1882db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1883db616173SMichal Hocko	bool "on"
1884db616173SMichal Hocko	help
1885db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1886db616173SMichal Hocko	  line parameter.
1887db616173SMichal Hocko
1888db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1889db616173SMichal Hocko	bool "auto"
1890db616173SMichal Hocko	help
1891db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1892db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1893db616173SMichal Hockoendchoice
1894db616173SMichal Hocko
1895e7e05452SSean Christophersonconfig X86_SGX
1896e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1897e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1898e7e05452SSean Christopherson	depends on CRYPTO=y
1899e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1900e7e05452SSean Christopherson	select SRCU
1901e7e05452SSean Christopherson	select MMU_NOTIFIER
1902901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
1903e7e05452SSean Christopherson	help
1904e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1905e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1906e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1907e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1908e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1909e7e05452SSean Christopherson	  hardware.
1910e7e05452SSean Christopherson
1911e7e05452SSean Christopherson	  If unsure, say N.
1912e7e05452SSean Christopherson
1913506f1d07SSam Ravnborgconfig EFI
19149ba16087SJan Beulich	bool "EFI runtime service support"
19155b83683fSHuang, Ying	depends on ACPI
1916f6ce5002SSergey Vlasov	select UCS2_STRING
1917022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1918a7f7f624SMasahiro Yamada	help
19198b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1920506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1921506f1d07SSam Ravnborg
19228b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19238b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19248b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19258b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19268b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19278b2cb7a8SHuang, Ying	  platforms.
1928506f1d07SSam Ravnborg
1929291f3632SMatt Flemingconfig EFI_STUB
1930291f3632SMatt Fleming	bool "EFI stub support"
1931b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19328f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19337b2a583aSMatt Fleming	select RELOCATABLE
1934a7f7f624SMasahiro Yamada	help
1935291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1936291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1937291f3632SMatt Fleming
19384f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19390c759662SMatt Fleming
19407d453eeeSMatt Flemingconfig EFI_MIXED
19417d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19427d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1943a7f7f624SMasahiro Yamada	help
19447d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19457d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19467d453eeeSMatt Fleming	   mode.
19477d453eeeSMatt Fleming
19487d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19497d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19507d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19517d453eeeSMatt Fleming
19527d453eeeSMatt Fleming	   If unsure, say N.
19537d453eeeSMatt Fleming
19548636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1955506f1d07SSam Ravnborg
1956506f1d07SSam Ravnborgconfig KEXEC
1957506f1d07SSam Ravnborg	bool "kexec system call"
19582965faa5SDave Young	select KEXEC_CORE
1959a7f7f624SMasahiro Yamada	help
1960506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1961506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1962506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1963506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1964506f1d07SSam Ravnborg
1965506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1966506f1d07SSam Ravnborg
1967506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1968506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1969bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1970bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1971bf220695SGeert Uytterhoeven	  made.
1972506f1d07SSam Ravnborg
197374ca317cSVivek Goyalconfig KEXEC_FILE
197474ca317cSVivek Goyal	bool "kexec file based system call"
19752965faa5SDave Young	select KEXEC_CORE
197674ca317cSVivek Goyal	select BUILD_BIN2C
197774ca317cSVivek Goyal	depends on X86_64
197874ca317cSVivek Goyal	depends on CRYPTO=y
197974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
1980a7f7f624SMasahiro Yamada	help
198174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
198274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
198374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
198474ca317cSVivek Goyal	  accepted by previous system call.
198574ca317cSVivek Goyal
1986b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
1987b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
1988b799a09fSAKASHI Takahiro
198999d5cadfSJiri Bohacconfig KEXEC_SIG
19908e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
199174ca317cSVivek Goyal	depends on KEXEC_FILE
1992a7f7f624SMasahiro Yamada	help
199399d5cadfSJiri Bohac
199499d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
199599d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
199699d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
199799d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
199899d5cadfSJiri Bohac
199999d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
200099d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
200199d5cadfSJiri Bohac	  loaded in order for this to work.
200299d5cadfSJiri Bohac
200399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
200499d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
200599d5cadfSJiri Bohac	depends on KEXEC_SIG
2006a7f7f624SMasahiro Yamada	help
20078e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2008d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20098e7d8381SVivek Goyal
20108e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20118e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
201299d5cadfSJiri Bohac	depends on KEXEC_SIG
20138e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20148e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2015a7f7f624SMasahiro Yamada	help
20168e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20178e7d8381SVivek Goyal
2018506f1d07SSam Ravnborgconfig CRASH_DUMP
201904b69447SPavel Machek	bool "kernel crash dumps"
2020506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2021a7f7f624SMasahiro Yamada	help
2022506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2023506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2024506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2025506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2026506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2027506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2028506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2029506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2030330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2031506f1d07SSam Ravnborg
20323ab83521SHuang Yingconfig KEXEC_JUMP
20336ea30386SKees Cook	bool "kexec jump"
2034fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2035a7f7f624SMasahiro Yamada	help
203689081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
203789081d17SHuang Ying	  code in physical address mode via KEXEC
20383ab83521SHuang Ying
2039506f1d07SSam Ravnborgconfig PHYSICAL_START
20406a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2041ceefccc9SH. Peter Anvin	default "0x1000000"
2042a7f7f624SMasahiro Yamada	help
2043506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2044506f1d07SSam Ravnborg
2045506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2046506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2047506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2048506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2049506f1d07SSam Ravnborg	  address.
2050506f1d07SSam Ravnborg
2051506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2052506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2053506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2054506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2055506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2056506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2057506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2058506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2059506f1d07SSam Ravnborg
2060ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2061ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2062ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2063ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2064ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2065ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2066ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2067330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2068ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2069506f1d07SSam Ravnborg
2070506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2071506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2072506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2073506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2074506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2075506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2076506f1d07SSam Ravnborg	  line.
2077506f1d07SSam Ravnborg
2078506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2079506f1d07SSam Ravnborg
2080506f1d07SSam Ravnborgconfig RELOCATABLE
208126717808SH. Peter Anvin	bool "Build a relocatable kernel"
208226717808SH. Peter Anvin	default y
2083a7f7f624SMasahiro Yamada	help
2084506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2085506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2086506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2087506f1d07SSam Ravnborg	  but are discarded at runtime.
2088506f1d07SSam Ravnborg
2089506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2090506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2091506f1d07SSam Ravnborg	  kernel.
2092506f1d07SSam Ravnborg
2093506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2094506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
20958ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2096506f1d07SSam Ravnborg
20978ab3820fSKees Cookconfig RANDOMIZE_BASE
2098e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
20998ab3820fSKees Cook	depends on RELOCATABLE
21006807c846SIngo Molnar	default y
2101a7f7f624SMasahiro Yamada	help
2102e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2103e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2104e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2105e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2106e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2107e8581e3dSBaoquan He	  code internals.
2108e8581e3dSBaoquan He
2109ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2110ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2111ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2112ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2113ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2114ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2115ed9f007eSKees Cook
2116ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2117ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2118ed9f007eSKees Cook	  512MB (8 bits of entropy).
21198ab3820fSKees Cook
2120a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2121e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2122e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2123ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2124ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2125ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2126ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2127ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2128ed9f007eSKees Cook	  limited due to memory layouts.
2129e8581e3dSBaoquan He
21306807c846SIngo Molnar	  If unsure, say Y.
2131da2b6fb9SKees Cook
21328ab3820fSKees Cook# Relocation on x86 needs some additional build support
2133845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2134845adf72SH. Peter Anvin	def_bool y
21358ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2136845adf72SH. Peter Anvin
2137506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2138a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21398ab3820fSKees Cook	default "0x200000"
2140a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2141a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2142a7f7f624SMasahiro Yamada	help
2143506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2144506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2145506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2146506f1d07SSam Ravnborg
2147506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2148506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2149506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2150506f1d07SSam Ravnborg
2151506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2152506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2153506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2154506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2155506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2156506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2157506f1d07SSam Ravnborg	  above alignment restrictions.
2158506f1d07SSam Ravnborg
2159a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2160a0215061SKees Cook	  this value must be a multiple of 0x200000.
2161a0215061SKees Cook
2162506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2163506f1d07SSam Ravnborg
2164eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2165eedb92abSKirill A. Shutemov	bool
2166a7f7f624SMasahiro Yamada	help
2167eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2168eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2169eedb92abSKirill A. Shutemov
21700483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21710483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21720483e1faSThomas Garnier	depends on X86_64
21730483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2174eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21750483e1faSThomas Garnier	default RANDOMIZE_BASE
2176a7f7f624SMasahiro Yamada	help
21770483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21780483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21790483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21800483e1faSThomas Garnier
21810483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21820483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21830483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21840483e1faSThomas Garnier	   addresses for each memory section.
21850483e1faSThomas Garnier
21866807c846SIngo Molnar	   If unsure, say Y.
21870483e1faSThomas Garnier
218890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
218990397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
219090397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
219190397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
219290397a41SThomas Garnier	default "0x0"
219390397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
219490397a41SThomas Garnier	range 0x0 0x40
2195a7f7f624SMasahiro Yamada	help
219690397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
219790397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
219890397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
219990397a41SThomas Garnier	   address randomization.
220090397a41SThomas Garnier
220190397a41SThomas Garnier	   If unsure, leave at the default value.
220290397a41SThomas Garnier
2203506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2204bebd024eSThomas Gleixner	def_bool y
220540b31360SStephen Rothwell	depends on SMP
2206506f1d07SSam Ravnborg
220780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
220880aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22092c922cd0SKees Cook	depends on HOTPLUG_CPU
2210a7f7f624SMasahiro Yamada	help
221180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
221280aa1dffSFenghua Yu
221380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
221480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
221580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
221680aa1dffSFenghua Yu
221780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
221880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
221980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
222080aa1dffSFenghua Yu
222180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
222280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
222380aa1dffSFenghua Yu
222480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
222580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
222680aa1dffSFenghua Yu	  be other CPU0 dependencies.
222780aa1dffSFenghua Yu
222880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
222980aa1dffSFenghua Yu	  you enable this feature.
223080aa1dffSFenghua Yu
223180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
223280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
223380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
223480aa1dffSFenghua Yu
2235a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2236a71c8bc5SFenghua Yu	def_bool n
2237a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22382c922cd0SKees Cook	depends on HOTPLUG_CPU
2239a7f7f624SMasahiro Yamada	help
2240a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2241a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2242a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2243a71c8bc5SFenghua Yu
2244a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2245a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2246a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2247a71c8bc5SFenghua Yu
2248a71c8bc5SFenghua Yu	  If unsure, say N.
2249a71c8bc5SFenghua Yu
2250506f1d07SSam Ravnborgconfig COMPAT_VDSO
2251b0b49f26SAndy Lutomirski	def_bool n
2252b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2253953fee1dSIngo Molnar	depends on COMPAT_32
2254a7f7f624SMasahiro Yamada	help
2255b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2256b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2257b0b49f26SAndy Lutomirski	  indicated in its segment table.
2258e84446deSRandy Dunlap
2259b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2260b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2261b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2262b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2263b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2264506f1d07SSam Ravnborg
2265b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2266b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2267b0b49f26SAndy Lutomirski
2268b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2269b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2270b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2271b0b49f26SAndy Lutomirski
2272b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2273b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2274506f1d07SSam Ravnborg
22753dc33bd3SKees Cookchoice
22763dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22773dc33bd3SKees Cook	depends on X86_64
2278625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
22793dc33bd3SKees Cook	help
22803dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22813dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22823dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22833dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22843dc33bd3SKees Cook
22853dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2286bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
22873dc33bd3SKees Cook
22883dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22893dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22903dc33bd3SKees Cook	  to improve security.
22913dc33bd3SKees Cook
2292bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
22933dc33bd3SKees Cook
22943dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2295bd49e16eSAndy Lutomirski		bool "Full emulation"
22963dc33bd3SKees Cook		help
2297bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2298bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2299bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2300bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2301bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2302bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2303bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2304bd49e16eSAndy Lutomirski
2305bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2306bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2307bd49e16eSAndy Lutomirski
2308bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2309bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2310bd49e16eSAndy Lutomirski		help
2311bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2312bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2313bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2314bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2315bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2316bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2317bd49e16eSAndy Lutomirski		  buffer.
23183dc33bd3SKees Cook
23193dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23203dc33bd3SKees Cook		bool "None"
23213dc33bd3SKees Cook		help
23223dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23233dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23243dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23253dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23263dc33bd3SKees Cook		  malicious userspace programs can be identified.
23273dc33bd3SKees Cook
23283dc33bd3SKees Cookendchoice
23293dc33bd3SKees Cook
2330516cbf37STim Birdconfig CMDLINE_BOOL
2331516cbf37STim Bird	bool "Built-in kernel command line"
2332a7f7f624SMasahiro Yamada	help
2333516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2334516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2335516cbf37STim Bird	  necessary or convenient to provide some or all of the
2336516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2337516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2338516cbf37STim Bird
2339516cbf37STim Bird	  To compile command line arguments into the kernel,
2340516cbf37STim Bird	  set this option to 'Y', then fill in the
234169711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2342516cbf37STim Bird
2343516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2344516cbf37STim Bird	  should leave this option set to 'N'.
2345516cbf37STim Bird
2346516cbf37STim Birdconfig CMDLINE
2347516cbf37STim Bird	string "Built-in kernel command string"
2348516cbf37STim Bird	depends on CMDLINE_BOOL
2349516cbf37STim Bird	default ""
2350a7f7f624SMasahiro Yamada	help
2351516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2352516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2353516cbf37STim Bird	  command line at boot time, it is appended to this string to
2354516cbf37STim Bird	  form the full kernel command line, when the system boots.
2355516cbf37STim Bird
2356516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2357516cbf37STim Bird	  change this behavior.
2358516cbf37STim Bird
2359516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2360516cbf37STim Bird	  by the boot loader) should specify the device for the root
2361516cbf37STim Bird	  file system.
2362516cbf37STim Bird
2363516cbf37STim Birdconfig CMDLINE_OVERRIDE
2364516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2365645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2366a7f7f624SMasahiro Yamada	help
2367516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2368516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2369516cbf37STim Bird
2370516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2371516cbf37STim Bird	  be set to 'N' under normal conditions.
2372516cbf37STim Bird
2373a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2374a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2375a5b9e5a2SAndy Lutomirski	default y
2376a7f7f624SMasahiro Yamada	help
2377a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2378a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2379a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2380a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2381a5b9e5a2SAndy Lutomirski	  threading libraries.
2382a5b9e5a2SAndy Lutomirski
2383a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2384a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2385a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2386a5b9e5a2SAndy Lutomirski
2387a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2388a5b9e5a2SAndy Lutomirski
2389b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2390b700e7f0SSeth Jennings
2391506f1d07SSam Ravnborgendmenu
2392506f1d07SSam Ravnborg
23933072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23943072e413SMichal Hocko	def_bool y
23953072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
23963072e413SMichal Hocko
2397f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2398f91ef222SOscar Salvador	def_bool y
2399f91ef222SOscar Salvador
2400e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2401645a7919STejun Heo	def_bool y
2402e534c7c5SLee Schermerhorn	depends on NUMA
2403e534c7c5SLee Schermerhorn
2404da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2405e279b6c1SSam Ravnborg
2406e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24073c2362e6SHarvey Harrison	def_bool y
240844556530SZhimin Gu	depends on HIBERNATION
2409e279b6c1SSam Ravnborg
2410e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2411e279b6c1SSam Ravnborg
2412e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2413e279b6c1SSam Ravnborg
2414a6b68076SAndi Kleenconfig X86_APM_BOOT
24156fc108a0SJan Beulich	def_bool y
2416282e5aabSPaul Bolle	depends on APM
2417a6b68076SAndi Kleen
2418e279b6c1SSam Ravnborgmenuconfig APM
2419e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2420efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2421a7f7f624SMasahiro Yamada	help
2422e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2423e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2424e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2425e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2426e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2427e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2428e279b6c1SSam Ravnborg
2429e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2430e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2431e279b6c1SSam Ravnborg
2432e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2433e279b6c1SSam Ravnborg	  machines with more than one CPU.
2434e279b6c1SSam Ravnborg
2435e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2436151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24372dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2438e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2439e279b6c1SSam Ravnborg
2440e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2441e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2442e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2443e279b6c1SSam Ravnborg
2444e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2445e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2446e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2447e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2448e279b6c1SSam Ravnborg
2449e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2450e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2451e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2452e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2453e279b6c1SSam Ravnborg	  APM in your BIOS).
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2456e279b6c1SSam Ravnborg	  "weird" problems:
2457e279b6c1SSam Ravnborg
2458e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2459e279b6c1SSam Ravnborg	  enabled.
2460e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2461e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2462e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2463e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2464e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2465e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2466e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2467e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2468e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2469e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2470e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2471e279b6c1SSam Ravnborg	  11) exchange RAM chips
2472e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2473e279b6c1SSam Ravnborg
2474e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2475e279b6c1SSam Ravnborg	  module will be called apm.
2476e279b6c1SSam Ravnborg
2477e279b6c1SSam Ravnborgif APM
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2480e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2481a7f7f624SMasahiro Yamada	help
2482e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2483e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2484e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2485e279b6c1SSam Ravnborg
2486e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2487e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2488a7f7f624SMasahiro Yamada	help
2489e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2490e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2491e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2492e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2493e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2494e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2495e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2496e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2497e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2498e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2499e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2500e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2501e279b6c1SSam Ravnborg	  this feature.
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2504dd8af076SLen Brown	depends on CPU_IDLE
2505e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2506a7f7f624SMasahiro Yamada	help
2507e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2508e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2509e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2510e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2511e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2512e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2513e279b6c1SSam Ravnborg	  this option does nothing.)
2514e279b6c1SSam Ravnborg
2515e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2516e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2517a7f7f624SMasahiro Yamada	help
2518e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2519e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2520e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2521e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2522e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2523e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2524e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2525e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2526e279b6c1SSam Ravnborg	  especially if you are using gpm.
2527e279b6c1SSam Ravnborg
2528e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2529e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2530a7f7f624SMasahiro Yamada	help
2531e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2532e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2533e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2534e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2535e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2536e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2537e279b6c1SSam Ravnborg
2538e279b6c1SSam Ravnborgendif # APM
2539e279b6c1SSam Ravnborg
2540bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2541e279b6c1SSam Ravnborg
2542e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2543e279b6c1SSam Ravnborg
254427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
254527471fdbSAndy Henroid
2546e279b6c1SSam Ravnborgendmenu
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborg
2549e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2550e279b6c1SSam Ravnborg
2551e279b6c1SSam Ravnborgchoice
2552e279b6c1SSam Ravnborg	prompt "PCI access mode"
2553efefa6f6SIngo Molnar	depends on X86_32 && PCI
2554e279b6c1SSam Ravnborg	default PCI_GOANY
2555a7f7f624SMasahiro Yamada	help
2556e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2557e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2558e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2559e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2560e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2561e279b6c1SSam Ravnborg
2562e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2563e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2564e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2565e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2566e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2567e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2568e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2569e279b6c1SSam Ravnborg
2570e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2571e279b6c1SSam Ravnborg	bool "BIOS"
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2574e279b6c1SSam Ravnborg	bool "MMConfig"
2575e279b6c1SSam Ravnborg
2576e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2577e279b6c1SSam Ravnborg	bool "Direct"
2578e279b6c1SSam Ravnborg
25793ef0e1f8SAndres Salomonconfig PCI_GOOLPC
258076fb6570SDaniel Drake	bool "OLPC XO-1"
25813ef0e1f8SAndres Salomon	depends on OLPC
25823ef0e1f8SAndres Salomon
25832bdd1b03SAndres Salomonconfig PCI_GOANY
25842bdd1b03SAndres Salomon	bool "Any"
25852bdd1b03SAndres Salomon
2586e279b6c1SSam Ravnborgendchoice
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgconfig PCI_BIOS
25893c2362e6SHarvey Harrison	def_bool y
2590efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2593e279b6c1SSam Ravnborgconfig PCI_DIRECT
25943c2362e6SHarvey Harrison	def_bool y
25950aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2596e279b6c1SSam Ravnborg
2597e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2598b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2599b45c9f36SJan Kiszka	default y
26004590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2601b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2602e279b6c1SSam Ravnborg
26033ef0e1f8SAndres Salomonconfig PCI_OLPC
26042bdd1b03SAndres Salomon	def_bool y
26052bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26063ef0e1f8SAndres Salomon
2607b5401a96SAlex Nixonconfig PCI_XEN
2608b5401a96SAlex Nixon	def_bool y
2609b5401a96SAlex Nixon	depends on PCI && XEN
2610b5401a96SAlex Nixon	select SWIOTLB_XEN
2611b5401a96SAlex Nixon
26128364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26138364e1f8SJan Kiszka	def_bool y
26148364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2615e279b6c1SSam Ravnborg
26163f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26176a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26186ea30386SKees Cook	depends on PCI
26193f6ea84aSIra W. Snyder	help
26203f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26213f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26223f6ea84aSIra W. Snyder	  not have ACPI.
26233f6ea84aSIra W. Snyder
262464a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
262564a5fed6SBjorn Helgaas	  is known to be incomplete.
262664a5fed6SBjorn Helgaas
262764a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
262864a5fed6SBjorn Helgaas
26293a495511SWilliam Breathitt Grayconfig ISA_BUS
263017a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26313a495511SWilliam Breathitt Gray	help
263217a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
263317a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
263417a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
263517a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
263617a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26373a495511SWilliam Breathitt Gray
26383a495511SWilliam Breathitt Gray	  If unsure, say N.
26393a495511SWilliam Breathitt Gray
26401c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2641e279b6c1SSam Ravnborgconfig ISA_DMA_API
26421c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26431c00f016SDavid Rientjes	default y
26441c00f016SDavid Rientjes	help
26451c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26461c00f016SDavid Rientjes	  If unsure, say Y.
2647e279b6c1SSam Ravnborg
264851e68d05SLinus Torvaldsif X86_32
264951e68d05SLinus Torvalds
2650e279b6c1SSam Ravnborgconfig ISA
2651e279b6c1SSam Ravnborg	bool "ISA support"
2652a7f7f624SMasahiro Yamada	help
2653e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2654e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2655e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2656e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2657e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2658e279b6c1SSam Ravnborg
2659e279b6c1SSam Ravnborgconfig SCx200
2660e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2661a7f7f624SMasahiro Yamada	help
2662e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2663e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2664e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2665e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2666e279b6c1SSam Ravnborg
2667e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2668e279b6c1SSam Ravnborg
2669e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2670e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2671592913ecSJohn Stultz	depends on SCx200
2672e279b6c1SSam Ravnborg	default y
2673a7f7f624SMasahiro Yamada	help
2674e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2675e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2676e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2677e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2678e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2679e279b6c1SSam Ravnborg
26803ef0e1f8SAndres Salomonconfig OLPC
26813ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
268254008979SThomas Gleixner	depends on !X86_PAE
26833c554946SAndres Salomon	select GPIOLIB
2684dc3119e7SThomas Gleixner	select OF
268545bb1674SDaniel Drake	select OF_PROMTREE
2686b4e51854SGrant Likely	select IRQ_DOMAIN
26870c3d931bSLubomir Rintel	select OLPC_EC
2688a7f7f624SMasahiro Yamada	help
26893ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
26903ef0e1f8SAndres Salomon	  XO hardware.
26913ef0e1f8SAndres Salomon
2692a3128588SDaniel Drakeconfig OLPC_XO1_PM
2693a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2694fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2695a7f7f624SMasahiro Yamada	help
269697c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2697bf1ebf00SDaniel Drake
2698cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2699cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2700cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2701a7f7f624SMasahiro Yamada	help
2702cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2703cfee9597SDaniel Drake	  programmable wakeup source.
2704cfee9597SDaniel Drake
27057feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27067feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
270792e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2708ed8e47feSRandy Dunlap	depends on INPUT=y
2709d8d01a63SDaniel Drake	select POWER_SUPPLY
2710a7f7f624SMasahiro Yamada	help
27117feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27127bc74b3dSDaniel Drake	   - EC-driven system wakeups
27137feda8e9SDaniel Drake	   - Power button
27147bc74b3dSDaniel Drake	   - Ebook switch
27152cf2baeaSDaniel Drake	   - Lid switch
2716e1040ac6SDaniel Drake	   - AC adapter status updates
2717e1040ac6SDaniel Drake	   - Battery status updates
27187feda8e9SDaniel Drake
2719a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2720a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2721d8d01a63SDaniel Drake	depends on OLPC && ACPI
2722d8d01a63SDaniel Drake	select POWER_SUPPLY
2723a7f7f624SMasahiro Yamada	help
2724a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2725a0f30f59SDaniel Drake	   - EC-driven system wakeups
2726a0f30f59SDaniel Drake	   - AC adapter status updates
2727a0f30f59SDaniel Drake	   - Battery status updates
2728e279b6c1SSam Ravnborg
2729d4f3e350SEd Wildgooseconfig ALIX
2730d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2731d4f3e350SEd Wildgoose	select GPIOLIB
2732a7f7f624SMasahiro Yamada	help
2733d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2734d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2735d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2736d4f3e350SEd Wildgoose	  get added here.
2737d4f3e350SEd Wildgoose
2738d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2739d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2740d4f3e350SEd Wildgoose
2741d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2742d4f3e350SEd Wildgoose
2743da4e3302SPhilip Prindevilleconfig NET5501
2744da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2745da4e3302SPhilip Prindeville	select GPIOLIB
2746a7f7f624SMasahiro Yamada	help
2747da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2748da4e3302SPhilip Prindeville
27493197059aSPhilip A. Prindevilleconfig GEOS
27503197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27513197059aSPhilip A. Prindeville	select GPIOLIB
27523197059aSPhilip A. Prindeville	depends on DMI
2753a7f7f624SMasahiro Yamada	help
27543197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27553197059aSPhilip A. Prindeville
27567d029125SVivien Didelotconfig TS5500
27577d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27587d029125SVivien Didelot	depends on MELAN
27597d029125SVivien Didelot	select CHECK_SIGNATURE
27607d029125SVivien Didelot	select NEW_LEDS
27617d029125SVivien Didelot	select LEDS_CLASS
2762a7f7f624SMasahiro Yamada	help
27637d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27647d029125SVivien Didelot
2765e279b6c1SSam Ravnborgendif # X86_32
2766e279b6c1SSam Ravnborg
276723ac4ae8SAndreas Herrmannconfig AMD_NB
2768e279b6c1SSam Ravnborg	def_bool y
27690e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2770e279b6c1SSam Ravnborg
2771e3263ab3SDavid Herrmannconfig X86_SYSFB
2772e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2773e3263ab3SDavid Herrmann	help
2774e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2775e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2776e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2777e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2778e3263ab3SDavid Herrmann	  to x86.
2779e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2780e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2781e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2782e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2783e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2784e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2785e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2786e3263ab3SDavid Herrmann
2787e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2788e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2789e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2790e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2791e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2792e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2793e3263ab3SDavid Herrmann	  incompatible with simplefb.
2794e3263ab3SDavid Herrmann
2795e3263ab3SDavid Herrmann	  If unsure, say Y.
2796e3263ab3SDavid Herrmann
2797e279b6c1SSam Ravnborgendmenu
2798e279b6c1SSam Ravnborg
2799e279b6c1SSam Ravnborg
28001572497cSChristoph Hellwigmenu "Binary Emulations"
2801e279b6c1SSam Ravnborg
2802e279b6c1SSam Ravnborgconfig IA32_EMULATION
2803e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2804e279b6c1SSam Ravnborg	depends on X86_64
280539f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2806d1603990SRandy Dunlap	select BINFMT_ELF
280739f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2808a7f7f624SMasahiro Yamada	help
28095fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28105fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28115fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2812e279b6c1SSam Ravnborg
2813e279b6c1SSam Ravnborgconfig IA32_AOUT
2814e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28156b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2816eac61655SBorislav Petkov	depends on BROKEN
2817a7f7f624SMasahiro Yamada	help
2818e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2819e279b6c1SSam Ravnborg
28200bf62763SH. Peter Anvinconfig X86_X32
28216ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28229b54050bSBrian Gerst	depends on X86_64
2823a7f7f624SMasahiro Yamada	help
28245fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28255fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28265fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28275fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28285fd92e65SH. J. Lu
28295fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28305fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28315fd92e65SH. J. Lu	  option set.
28325fd92e65SH. J. Lu
2833953fee1dSIngo Molnarconfig COMPAT_32
2834953fee1dSIngo Molnar	def_bool y
2835953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2836953fee1dSIngo Molnar	select HAVE_UID16
2837953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2838953fee1dSIngo Molnar
2839e279b6c1SSam Ravnborgconfig COMPAT
28403c2362e6SHarvey Harrison	def_bool y
28410bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2842e279b6c1SSam Ravnborg
28433120e25eSJan Beulichif COMPAT
2844e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28453120e25eSJan Beulich	def_bool y
2846e279b6c1SSam Ravnborg
2847e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28483c2362e6SHarvey Harrison	def_bool y
28493120e25eSJan Beulich	depends on SYSVIPC
28503120e25eSJan Beulichendif
2851ee009e4aSDavid Howells
2852e279b6c1SSam Ravnborgendmenu
2853e279b6c1SSam Ravnborg
2854e279b6c1SSam Ravnborg
2855e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2856e5beae16SKeith Packard	def_bool y
2857e5beae16SKeith Packard	depends on X86_32
2858e5beae16SKeith Packard
2859e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2860e279b6c1SSam Ravnborg
2861edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28625e8ebd84SJason A. Donenfeld
28635e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2864