xref: /linux/arch/x86/Kconfig (revision d7109fe3a0991a0f7b4ac099b78c908e3b619787)
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
122b5f06f64SBalbir 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_IOREMAP_PROT
207624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2086471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2096471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2106471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2116471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2126471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2136471b825SIngo Molnar	select HAVE_KERNEL_LZO
2146471b825SIngo Molnar	select HAVE_KERNEL_XZ
215fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2166471b825SIngo Molnar	select HAVE_KPROBES
2176471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
218540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2196471b825SIngo Molnar	select HAVE_KRETPROBES
2206471b825SIngo Molnar	select HAVE_KVM
2216471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2220102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
223ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2249f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
225be37c98dSKalesh Singh	select HAVE_MOVE_PUD
22642a0bb3fSPetr Mladek	select HAVE_NMI
2276471b825SIngo Molnar	select HAVE_OPTPROBES
2286471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2296471b825SIngo Molnar	select HAVE_PERF_EVENTS
230c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23192e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
232eb01d42aSChristoph Hellwig	select HAVE_PCI
233c5e63197SJiri Olsa	select HAVE_PERF_REGS
234c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
235ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
23600998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2376471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2386415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2393c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
240cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
241d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
242c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
243e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2441e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2456ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
246d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2476471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2486471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2497c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2507ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25105736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
252c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
25386596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2542eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
255625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2566471b825SIngo Molnar	select PERF_EVENTS
2573195ef59SPrarit Bhargava	select RTC_LIB
258d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2596471b825SIngo Molnar	select SPARSE_IRQ
26083fe27eaSPranith Kumar	select SRCU
2611e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2626471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26315f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2646471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2656471b825SIngo Molnar	select VIRT_TO_BUS
2663b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2676471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2680c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2699e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2707d8330a5SBalbir Singh
271ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2723120e25eSJan Beulich	def_bool y
2733120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
274ba7e4d13SIngo Molnar
27551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
27651b26adaSLinus Torvalds	string
27751b26adaSLinus Torvalds	default "elf32-i386" if X86_32
27851b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
27951b26adaSLinus Torvalds
2808d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2813c2362e6SHarvey Harrison	def_bool y
2828d5fffb9SSam Ravnborg
2838d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2843c2362e6SHarvey Harrison	def_bool y
2858d5fffb9SSam Ravnborg
2868d5fffb9SSam Ravnborgconfig MMU
2873c2362e6SHarvey Harrison	def_bool y
2888d5fffb9SSam Ravnborg
2899e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2909e08f57dSDaniel Cashman	default 28 if 64BIT
2919e08f57dSDaniel Cashman	default 8
2929e08f57dSDaniel Cashman
2939e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2949e08f57dSDaniel Cashman	default 32 if 64BIT
2959e08f57dSDaniel Cashman	default 16
2969e08f57dSDaniel Cashman
2979e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
2989e08f57dSDaniel Cashman	default 8
2999e08f57dSDaniel Cashman
3009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3019e08f57dSDaniel Cashman	default 16
3029e08f57dSDaniel Cashman
3038d5fffb9SSam Ravnborgconfig SBUS
3048d5fffb9SSam Ravnborg	bool
3058d5fffb9SSam Ravnborg
3068d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3073120e25eSJan Beulich	def_bool y
3083120e25eSJan Beulich	depends on ISA_DMA_API
3098d5fffb9SSam Ravnborg
3108d5fffb9SSam Ravnborgconfig GENERIC_BUG
3113c2362e6SHarvey Harrison	def_bool y
3128d5fffb9SSam Ravnborg	depends on BUG
313b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
314b93a531eSJan Beulich
315b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
316b93a531eSJan Beulich	bool
3178d5fffb9SSam Ravnborg
3188d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3193120e25eSJan Beulich	def_bool y
3203120e25eSJan Beulich	depends on ISA_DMA_API
3218d5fffb9SSam Ravnborg
3221032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3231032c0baSSam Ravnborg	def_bool y
3241032c0baSSam Ravnborg
3259a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3269a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3278d5fffb9SSam Ravnborg
328316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
329316d097cSDave Hansen	def_bool y
330316d097cSDave Hansen
331dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
33289c9c4c5SBrian Gerst	def_bool y
333b32ef636Stravis@sgi.com
33408fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
33508fc4580STejun Heo	def_bool y
33608fc4580STejun Heo
33708fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
33811124411STejun Heo	def_bool y
33911124411STejun Heo
340801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
341801e4062SJohannes Berg	def_bool y
342801e4062SJohannes Berg
343*d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
344*d7109fe3SAndy Shevchenko	int
345*d7109fe3SAndy Shevchenko	default 1024 if X86_64
346*d7109fe3SAndy Shevchenko	default 512
347*d7109fe3SAndy Shevchenko
348f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
349f4cb5700SJohannes Berg	def_bool y
350f4cb5700SJohannes Berg
35153313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
35253313b2cSSteve Capper	def_bool y
35353313b2cSSteve Capper
3548d5fffb9SSam Ravnborgconfig AUDIT_ARCH
355e0fd24a3SJan Beulich	def_bool y if X86_64
3568d5fffb9SSam Ravnborg
357d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
358d6f2d75aSAndrey Ryabinin	hex
359d6f2d75aSAndrey Ryabinin	depends on KASAN
360d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
361d6f2d75aSAndrey Ryabinin
36269575d38SShane Wangconfig HAVE_INTEL_TXT
36369575d38SShane Wang	def_bool y
3646ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36569575d38SShane Wang
3666b0c3d44SSam Ravnborgconfig X86_32_SMP
3676b0c3d44SSam Ravnborg	def_bool y
3686b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3696b0c3d44SSam Ravnborg
3706b0c3d44SSam Ravnborgconfig X86_64_SMP
3716b0c3d44SSam Ravnborg	def_bool y
3726b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3736b0c3d44SSam Ravnborg
3742b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3752b144498SSrikar Dronamraju	def_bool y
3762b144498SSrikar Dronamraju
377d20642f0SRob Herringconfig FIX_EARLYCON_MEM
378d20642f0SRob Herring	def_bool y
379d20642f0SRob Herring
38094d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
38194d49eb3SKirill A. Shutemov	bool
38294d49eb3SKirill A. Shutemov
38398233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38498233368SKirill A. Shutemov	int
38577ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38698233368SKirill A. Shutemov	default 4 if X86_64
38798233368SKirill A. Shutemov	default 3 if X86_PAE
38898233368SKirill A. Shutemov	default 2
38998233368SKirill A. Shutemov
3902a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3912a61f474SMasahiro Yamada	bool
3922a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3932a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3942a61f474SMasahiro Yamada	help
3952a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3963fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3973fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3982a61f474SMasahiro Yamada
399506f1d07SSam Ravnborgmenu "Processor type and features"
400506f1d07SSam Ravnborg
401506f1d07SSam Ravnborgconfig SMP
402506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
403a7f7f624SMasahiro Yamada	help
404506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4054a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4064a474157SRobert Graffham	  than one CPU, say Y.
407506f1d07SSam Ravnborg
4084a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
409506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
410506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4114a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
412506f1d07SSam Ravnborg	  will run faster if you say N here.
413506f1d07SSam Ravnborg
414506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
415506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
416506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
417506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
418506f1d07SSam Ravnborg
419506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
420506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
421506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
422506f1d07SSam Ravnborg
423cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4244f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
425506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
426506f1d07SSam Ravnborg
427506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
428506f1d07SSam Ravnborg
4299def39beSJosh Triplettconfig X86_FEATURE_NAMES
4309def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4319def39beSJosh Triplett	default y
432a7f7f624SMasahiro Yamada	help
4339def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4349def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4359def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4369def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4379def39beSJosh Triplett
4389def39beSJosh Triplett	  If in doubt, say Y.
4399def39beSJosh Triplett
44006cd9a7dSYinghai Luconfig X86_X2APIC
44106cd9a7dSYinghai Lu	bool "Support x2apic"
44219e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
443a7f7f624SMasahiro Yamada	help
44406cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44506cd9a7dSYinghai Lu
44606cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44706cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44806cd9a7dSYinghai Lu
44906cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
45006cd9a7dSYinghai Lu
4516695c85bSYinghai Luconfig X86_MPPARSE
4524590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4537a527688SJan Beulich	default y
4545ab74722SIngo Molnar	depends on X86_LOCAL_APIC
455a7f7f624SMasahiro Yamada	help
4566695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4576695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4586695c85bSYinghai Lu
459ddd70cf9SJun Nakajimaconfig GOLDFISH
460ddd70cf9SJun Nakajima	def_bool y
461ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
462ddd70cf9SJun Nakajima
46376b04384SDavid Woodhouseconfig RETPOLINE
46476b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46576b04384SDavid Woodhouse	default y
46676b04384SDavid Woodhouse	help
46776b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46876b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46976b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
47076b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
47176b04384SDavid Woodhouse
472e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
473e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4746fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
47559fe5a77SThomas Gleixner	select KERNFS
476e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
47778e99b4aSFenghua Yu	help
478e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4796fe07ce3SBabu Moger
4806fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4816fe07ce3SBabu Moger	  usage by the CPU.
4826fe07ce3SBabu Moger
4836fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4846fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4856fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4866fe07ce3SBabu Moger
4876fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4886fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4896fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49078e99b4aSFenghua Yu
49178e99b4aSFenghua Yu	  Say N if unsure.
49278e99b4aSFenghua Yu
4938425091fSRavikiran G Thirumalaiif X86_32
494a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
495a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
496a0d0bb4dSRandy Dunlap	depends on SMP
497a7f7f624SMasahiro Yamada	help
498e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
499a0d0bb4dSRandy Dunlap
500c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
501c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
502c5c606d9SRavikiran G Thirumalai	default y
503a7f7f624SMasahiro Yamada	help
50406ac8346SIngo Molnar	  If you disable this option then the kernel will only support
50506ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
50606ac8346SIngo Molnar	  systems out there.)
50706ac8346SIngo Molnar
5088425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5098425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
510cb7b8023SBen Hutchings		Goldfish (Android emulator)
5118425091fSRavikiran G Thirumalai		AMD Elan
5128425091fSRavikiran G Thirumalai		RDC R-321x SoC
5138425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
51483125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5153f4110a4SThomas Gleixner		Moorestown MID devices
51606ac8346SIngo Molnar
51706ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
51806ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5198425091fSRavikiran G Thirumalaiendif
52006ac8346SIngo Molnar
5218425091fSRavikiran G Thirumalaiif X86_64
5228425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5238425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5248425091fSRavikiran G Thirumalai	default y
525a7f7f624SMasahiro Yamada	help
5268425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5278425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5288425091fSRavikiran G Thirumalai	  systems out there.)
5298425091fSRavikiran G Thirumalai
5308425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5318425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
53244b111b5SSteffen Persvold		Numascale NumaChip
5338425091fSRavikiran G Thirumalai		ScaleMP vSMP
5348425091fSRavikiran G Thirumalai		SGI Ultraviolet
5358425091fSRavikiran G Thirumalai
5368425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5378425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5388425091fSRavikiran G Thirumalaiendif
539c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
540c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
54144b111b5SSteffen Persvoldconfig X86_NUMACHIP
54244b111b5SSteffen Persvold	bool "Numascale NumaChip"
54344b111b5SSteffen Persvold	depends on X86_64
54444b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
54544b111b5SSteffen Persvold	depends on NUMA
54644b111b5SSteffen Persvold	depends on SMP
54744b111b5SSteffen Persvold	depends on X86_X2APIC
548f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
549a7f7f624SMasahiro Yamada	help
55044b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
55144b111b5SSteffen Persvold	  enable more than ~168 cores.
55244b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
55303b48632SNick Piggin
5546a48565eSIngo Molnarconfig X86_VSMP
555c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5566276a074SBorislav Petkov	select HYPERVISOR_GUEST
5576a48565eSIngo Molnar	select PARAVIRT
5586a48565eSIngo Molnar	depends on X86_64 && PCI
559c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
560ead91d4bSShai Fultheim	depends on SMP
561a7f7f624SMasahiro Yamada	help
5626a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5636a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5646a48565eSIngo Molnar	  if you have one of these machines.
5656a48565eSIngo Molnar
566c5c606d9SRavikiran G Thirumalaiconfig X86_UV
567c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
568c5c606d9SRavikiran G Thirumalai	depends on X86_64
569c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
57054c28d29SJack Steiner	depends on NUMA
5711ecb4ae5SAndrew Morton	depends on EFI
572c2209ea5SIngo Molnar	depends on KEXEC_CORE
5739d6c26e7SSuresh Siddha	depends on X86_X2APIC
5741222e564SIngo Molnar	depends on PCI
575a7f7f624SMasahiro Yamada	help
576c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
577c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
578c5c606d9SRavikiran G Thirumalai
579c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
580c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
581506f1d07SSam Ravnborg
582ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
583ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
584cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
585a7f7f624SMasahiro Yamada	help
586ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
587ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
588ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
589ddd70cf9SJun Nakajima
590c751e17bSThomas Gleixnerconfig X86_INTEL_CE
591c751e17bSThomas Gleixner	bool "CE4100 TV platform"
592c751e17bSThomas Gleixner	depends on PCI
593c751e17bSThomas Gleixner	depends on PCI_GODIRECT
5946084a6e2SJiang Liu	depends on X86_IO_APIC
595c751e17bSThomas Gleixner	depends on X86_32
596c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
59737bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
598da6b737bSSebastian Andrzej Siewior	select OF
599da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
600a7f7f624SMasahiro Yamada	help
601c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
602c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
603c751e17bSThomas Gleixner	  boxes and media devices.
604c751e17bSThomas Gleixner
6054cb9b00fSDavid Cohenconfig X86_INTEL_MID
60643605ef1SAlan Cox	bool "Intel MID platform support"
60743605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
608edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6091ea7c673SAlan Cox	depends on PCI
6103fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6111ea7c673SAlan Cox	depends on X86_IO_APIC
6124cb9b00fSDavid Cohen	select I2C
6137c9c3a1eSAlan Cox	select DW_APB_TIMER
6141ea7c673SAlan Cox	select APB_TIMER
61554b34aa0SMika Westerberg	select INTEL_SCU_PCI
61615a713dfSMika Westerberg	select MFD_INTEL_MSIC
617a7f7f624SMasahiro Yamada	help
6184cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6194cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6204cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6211ea7c673SAlan Cox
6224cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6234cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
62443605ef1SAlan Cox
6258bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6268bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6278bbc2a13SBryan O'Donoghue	depends on X86_32
6288bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6298bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6308bbc2a13SBryan O'Donoghue	depends on X86_TSC
6318bbc2a13SBryan O'Donoghue	depends on PCI
6328bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6338bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6348bbc2a13SBryan O'Donoghue	select IOSF_MBI
6358bbc2a13SBryan O'Donoghue	select INTEL_IMR
6369ab6eb51SAndy Shevchenko	select COMMON_CLK
637a7f7f624SMasahiro Yamada	help
6388bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6398bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6408bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6418bbc2a13SBryan O'Donoghue
6423d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6433d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6445962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6453d48aab1SMika Westerberg	select COMMON_CLK
6460f531431SMathias Nyman	select PINCTRL
647eebb3e8dSAndy Shevchenko	select IOSF_MBI
648a7f7f624SMasahiro Yamada	help
6493d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6503d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6510f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6520f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6533d48aab1SMika Westerberg
65492082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
65592082a88SKen Xue	bool "AMD ACPI2Platform devices support"
65692082a88SKen Xue	depends on ACPI
65792082a88SKen Xue	select COMMON_CLK
65892082a88SKen Xue	select PINCTRL
659a7f7f624SMasahiro Yamada	help
66092082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66192082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
66292082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
66392082a88SKen Xue	  implemented under PINCTRL subsystem.
66492082a88SKen Xue
665ced3ce76SDavid E. Boxconfig IOSF_MBI
666ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
667ced3ce76SDavid E. Box	depends on PCI
668a7f7f624SMasahiro Yamada	help
669ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
670ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
671ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
672ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
673ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
674ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
675ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
676ced3ce76SDavid E. Box	   - BayTrail
677ced3ce76SDavid E. Box	   - Braswell
678ced3ce76SDavid E. Box	   - Quark
679ced3ce76SDavid E. Box
680ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
681ced3ce76SDavid E. Box
682ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
683ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
684ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
685a7f7f624SMasahiro Yamada	help
686ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
687ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
688ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
689ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
690ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
691ed2226bdSDavid E. Box	  device they want to access.
692ed2226bdSDavid E. Box
693ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
694ed2226bdSDavid E. Box
695c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
696c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
697506f1d07SSam Ravnborg	depends on X86_32
698c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
699c5c606d9SRavikiran G Thirumalai	select M486
700c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
701a7f7f624SMasahiro Yamada	help
702c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
703c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
704c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
705c5c606d9SRavikiran G Thirumalai
706e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7079c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7089c398017SIngo Molnar	depends on X86_32 && SMP
709c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
710a7f7f624SMasahiro Yamada	help
711b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
712b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
713b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
714b5660ba7SH. Peter Anvin	  one and will fallback to default.
715d49c4288SYinghai Lu
716c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
717d49c4288SYinghai Lu
718d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7196fc108a0SJan Beulich	def_bool y
720d949f36fSLinus Torvalds	# MCE code calls memory_failure():
721d949f36fSLinus Torvalds	depends on X86_MCE
722d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
723d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
724d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
725d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
726d949f36fSLinus Torvalds
72783125a3aSAlessandro Rubiniconfig STA2X11
72883125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
72983125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73083125a3aSAlessandro Rubini	select SWIOTLB
73183125a3aSAlessandro Rubini	select MFD_STA2X11
7320145071bSLinus Walleij	select GPIOLIB
733a7f7f624SMasahiro Yamada	help
73483125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
73583125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
73683125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
73783125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
73883125a3aSAlessandro Rubini	  standard PC machines.
73983125a3aSAlessandro Rubini
74082148d1dSShérabconfig X86_32_IRIS
74182148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
74282148d1dSShérab	depends on X86_32
743a7f7f624SMasahiro Yamada	help
74482148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
74582148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
74682148d1dSShérab	  needed to do so, which is what this module does at
74782148d1dSShérab	  kernel shutdown.
74882148d1dSShérab
74982148d1dSShérab	  This is only for Iris machines from EuroBraille.
75082148d1dSShérab
75182148d1dSShérab	  If unused, say N.
75282148d1dSShérab
753ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7543c2362e6SHarvey Harrison	def_bool y
7553c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
756a87d0914SKen Chen	depends on X86
757a7f7f624SMasahiro Yamada	help
758506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
759506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
760506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
761506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
762506f1d07SSam Ravnborg
763506f1d07SSam Ravnborg	  If in doubt, say "Y".
764506f1d07SSam Ravnborg
7656276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7666276a074SBorislav Petkov	bool "Linux guest support"
767a7f7f624SMasahiro Yamada	help
7686276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7696276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7706276a074SBorislav Petkov	  setup.
771506f1d07SSam Ravnborg
7726276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7736276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
774506f1d07SSam Ravnborg
7756276a074SBorislav Petkovif HYPERVISOR_GUEST
776506f1d07SSam Ravnborg
777e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
778e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
779a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
780a7f7f624SMasahiro Yamada	help
781e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
782e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
783e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
784e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
785e61bd94aSEduardo Pereira Habkost
786c00a280aSJuergen Grossconfig PARAVIRT_XXL
787c00a280aSJuergen Gross	bool
788c00a280aSJuergen Gross
7896276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7906276a074SBorislav Petkov	bool "paravirt-ops debugging"
7916276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
792a7f7f624SMasahiro Yamada	help
7936276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
7946276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
7956276a074SBorislav Petkov
796b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
797b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
7986ea30386SKees Cook	depends on PARAVIRT && SMP
799a7f7f624SMasahiro Yamada	help
800b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
801b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
802b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
803b4ecc126SJeremy Fitzhardinge
8044c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8054c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
806b4ecc126SJeremy Fitzhardinge
8074c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
808b4ecc126SJeremy Fitzhardinge
809ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
810ecca2502SZhao Yakui	def_bool n
811ecca2502SZhao Yakui
8126276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8136276a074SBorislav Petkov
8146276a074SBorislav Petkovconfig KVM_GUEST
8156276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8166276a074SBorislav Petkov	depends on PARAVIRT
8176276a074SBorislav Petkov	select PARAVIRT_CLOCK
818a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
819b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8206276a074SBorislav Petkov	default y
821a7f7f624SMasahiro Yamada	help
8226276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8236276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8246276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8256276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8266276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8276276a074SBorislav Petkov
828a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
829a1c4423bSMarcelo Tosatti	def_bool n
830a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
831a1c4423bSMarcelo Tosatti	help
832a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
833a1c4423bSMarcelo Tosatti
8347733607fSMaran Wilsonconfig PVH
8357733607fSMaran Wilson	bool "Support for running PVH guests"
836a7f7f624SMasahiro Yamada	help
8377733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8387733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8397733607fSMaran Wilson
8406276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8416276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8426276a074SBorislav Petkov	depends on PARAVIRT
843a7f7f624SMasahiro Yamada	help
8446276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8456276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8466276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8476276a074SBorislav Petkov	  that, there can be a small performance impact.
8486276a074SBorislav Petkov
8496276a074SBorislav Petkov	  If in doubt, say N here.
8506276a074SBorislav Petkov
8517af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8527af192c9SGerd Hoffmann	bool
8537af192c9SGerd Hoffmann
8544a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8554a362601SJan Kiszka	bool "Jailhouse non-root cell support"
856abde587bSArnd Bergmann	depends on X86_64 && PCI
85787e65d05SJan Kiszka	select X86_PM_TIMER
858a7f7f624SMasahiro Yamada	help
8594a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8604a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8614a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8624a362601SJan Kiszka
863ec7972c9SZhao Yakuiconfig ACRN_GUEST
864ec7972c9SZhao Yakui	bool "ACRN Guest support"
865ec7972c9SZhao Yakui	depends on X86_64
866498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
867ec7972c9SZhao Yakui	help
868ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
869ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
870ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
871ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
872ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
873ec7972c9SZhao Yakui
8746276a074SBorislav Petkovendif #HYPERVISOR_GUEST
87597349135SJeremy Fitzhardinge
876506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
877506f1d07SSam Ravnborg
878506f1d07SSam Ravnborgconfig HPET_TIMER
8793c2362e6SHarvey Harrison	def_bool X86_64
880506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
881a7f7f624SMasahiro Yamada	help
882506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
883506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
884506f1d07SSam Ravnborg	  present.
885506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
886506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
887506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
8884e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
8894e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
890506f1d07SSam Ravnborg
891506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
892506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
893506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
894506f1d07SSam Ravnborg
895506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
896506f1d07SSam Ravnborg
897506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
8983c2362e6SHarvey Harrison	def_bool y
8993228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
900506f1d07SSam Ravnborg
9016a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
902506f1d07SSam Ravnborg# The code disables itself when not needed.
9037ae9392cSThomas Petazzoniconfig DMI
9047ae9392cSThomas Petazzoni	default y
905cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9066a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
907a7f7f624SMasahiro Yamada	help
9087ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9097ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9107ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9117ae9392cSThomas Petazzoni	  BIOS code.
9127ae9392cSThomas Petazzoni
913506f1d07SSam Ravnborgconfig GART_IOMMU
91438901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9152f9237d4SChristoph Hellwig	select DMA_OPS
916a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
917506f1d07SSam Ravnborg	select SWIOTLB
91823ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
919a7f7f624SMasahiro Yamada	help
920ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
922ced3c42cSIngo Molnar
923ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
924ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
925ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
926ced3c42cSIngo Molnar
927ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
928ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
929ced3c42cSIngo Molnar
930ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
931ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
932ced3c42cSIngo Molnar	  32-bit limited device.
933ced3c42cSIngo Molnar
934ced3c42cSIngo Molnar	  If unsure, say Y.
935506f1d07SSam Ravnborg
9361184dc2fSMike Travisconfig MAXSMP
937ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9386ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
93936f5101aSMike Travis	select CPUMASK_OFFSTACK
940a7f7f624SMasahiro Yamada	help
941ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9421184dc2fSMike Travis	  If unsure, say N.
943506f1d07SSam Ravnborg
944aec6487eSIngo Molnar#
945aec6487eSIngo Molnar# The maximum number of CPUs supported:
946aec6487eSIngo Molnar#
947aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948aec6487eSIngo Molnar# and which can be configured interactively in the
949aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950aec6487eSIngo Molnar#
951aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
952aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
953aec6487eSIngo Molnar#
954aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
955aec6487eSIngo Molnar#   interactive configuration. )
956aec6487eSIngo Molnar#
957a0d0bb4dSRandy Dunlap
958aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
959a0d0bb4dSRandy Dunlap	int
960aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
961a0d0bb4dSRandy Dunlap	default    1 if !SMP
962a0d0bb4dSRandy Dunlap	default    2
963a0d0bb4dSRandy Dunlap
964aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
965a0d0bb4dSRandy Dunlap	int
966a0d0bb4dSRandy Dunlap	depends on X86_32
967aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
968aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
969a0d0bb4dSRandy Dunlap	default    1 if !SMP
970a0d0bb4dSRandy Dunlap
971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
972a0d0bb4dSRandy Dunlap	int
973a0d0bb4dSRandy Dunlap	depends on X86_64
9741edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9751edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
976a0d0bb4dSRandy Dunlap	default    1 if !SMP
977aec6487eSIngo Molnar
978aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
979aec6487eSIngo Molnar	int
980aec6487eSIngo Molnar	depends on X86_32
981aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
982aec6487eSIngo Molnar	default    8 if  SMP
983aec6487eSIngo Molnar	default    1 if !SMP
984aec6487eSIngo Molnar
985aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
986aec6487eSIngo Molnar	int
987aec6487eSIngo Molnar	depends on X86_64
988a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
989a0d0bb4dSRandy Dunlap	default   64 if  SMP
990aec6487eSIngo Molnar	default    1 if !SMP
991a0d0bb4dSRandy Dunlap
992506f1d07SSam Ravnborgconfig NR_CPUS
99336f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
994aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
996a7f7f624SMasahiro Yamada	help
997506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
998bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
999cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1000506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1001506f1d07SSam Ravnborg
1002aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1003aec6487eSIngo Molnar	  to the kernel image.
1004506f1d07SSam Ravnborg
1005506f1d07SSam Ravnborgconfig SCHED_SMT
1006dbe73364SThomas Gleixner	def_bool y if SMP
1007506f1d07SSam Ravnborg
1008506f1d07SSam Ravnborgconfig SCHED_MC
10093c2362e6SHarvey Harrison	def_bool y
10103c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1011c8e56d20SBorislav Petkov	depends on SMP
1012a7f7f624SMasahiro Yamada	help
1013506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1014506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1015506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1016506f1d07SSam Ravnborg
1017de966cf4STim Chenconfig SCHED_MC_PRIO
1018de966cf4STim Chen	bool "CPU core priorities scheduler support"
10190a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10200a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10210a21fc12SIngo Molnar	select CPU_FREQ
1022de966cf4STim Chen	default y
1023a7f7f624SMasahiro Yamada	help
1024de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1026de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1027de966cf4STim Chen	  single threaded workloads) than others.
1028de966cf4STim Chen
1029de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1030de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1032de966cf4STim Chen	  overall system performance can be achieved.
1033de966cf4STim Chen
1034de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1035de966cf4STim Chen
1036de966cf4STim Chen	  If unsure say Y here.
10375e76b2abSTim Chen
103830b8b006SThomas Gleixnerconfig UP_LATE_INIT
103930b8b006SThomas Gleixner	def_bool y
1040ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
104130b8b006SThomas Gleixner
1042506f1d07SSam Ravnborgconfig X86_UP_APIC
104350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
104450849eefSJan Beulich	default PCI_MSI
104538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1046a7f7f624SMasahiro Yamada	help
1047506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1048506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1049506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1050506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1051506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1052506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1053506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1054506f1d07SSam Ravnborg	  lockups.
1055506f1d07SSam Ravnborg
1056506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1057506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1058506f1d07SSam Ravnborg	depends on X86_UP_APIC
1059a7f7f624SMasahiro Yamada	help
1060506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1062506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1063506f1d07SSam Ravnborg
1064506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1065506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1066506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1067506f1d07SSam Ravnborg
1068506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10693c2362e6SHarvey Harrison	def_bool y
10700dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1071b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
107252f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1073506f1d07SSam Ravnborg
1074506f1d07SSam Ravnborgconfig X86_IO_APIC
1075b1da1e71SJan Beulich	def_bool y
1076b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1077506f1d07SSam Ravnborg
107841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
107941b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
108041b9eb26SStefan Assmann	depends on X86_IO_APIC
1081a7f7f624SMasahiro Yamada	help
108241b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
108341b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
108441b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
108541b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
108641b9eb26SStefan Assmann
108741b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
108841b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
108941b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
109041b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
109141b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
109241b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
109341b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
109441b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
109541b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
109641b9eb26SStefan Assmann	  down (vital) interrupt lines.
109741b9eb26SStefan Assmann
109841b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
109941b9eb26SStefan Assmann	  increased on these systems.
110041b9eb26SStefan Assmann
1101506f1d07SSam Ravnborgconfig X86_MCE
1102bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1103648ed940SChen, Gong	select GENERIC_ALLOCATOR
1104e57dbaf7SBorislav Petkov	default y
1105a7f7f624SMasahiro Yamada	help
1106bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1107bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1108506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1109bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11104efc0670SAndi Kleen
11115de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11125de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11135de97c9fSTony Luck	depends on X86_MCE
1114a7f7f624SMasahiro Yamada	help
11155de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11165de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11175de97c9fSTony Luck	  rasdaemon solution.
11185de97c9fSTony Luck
1119506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11203c2362e6SHarvey Harrison	def_bool y
11213c2362e6SHarvey Harrison	prompt "Intel MCE features"
1122c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1123a7f7f624SMasahiro Yamada	help
1124506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1125506f1d07SSam Ravnborg	   the thermal monitor.
1126506f1d07SSam Ravnborg
1127506f1d07SSam Ravnborgconfig X86_MCE_AMD
11283c2362e6SHarvey Harrison	def_bool y
11293c2362e6SHarvey Harrison	prompt "AMD MCE features"
1130f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1131a7f7f624SMasahiro Yamada	help
1132506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1133506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1134506f1d07SSam Ravnborg
11354efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11366fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1137c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1138a7f7f624SMasahiro Yamada	help
11394efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11405065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11414efc0670SAndi Kleen	  line.
11424efc0670SAndi Kleen
1143b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1144b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11456fc108a0SJan Beulich	def_bool y
1146b2762686SAndi Kleen
1147ea149b36SAndi Kleenconfig X86_MCE_INJECT
1148bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1149ea149b36SAndi Kleen	tristate "Machine check injector support"
1150a7f7f624SMasahiro Yamada	help
1151ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1152ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1153ea149b36SAndi Kleen	  QA it is safe to say n.
1154ea149b36SAndi Kleen
115507dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1156e633c65aSKan Liang
11575aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11581e642812SIngo Molnar	bool "Legacy VM86 support"
1159506f1d07SSam Ravnborg	depends on X86_32
1160a7f7f624SMasahiro Yamada	help
11615aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11625aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11635aef51c3SAndy Lutomirski
11645aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11655aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11665aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11675aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11685aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11691e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11701e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11711e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11721e642812SIngo Molnar	  enable this option.
11735aef51c3SAndy Lutomirski
11741e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11751e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
11761e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
11771e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
11785aef51c3SAndy Lutomirski
11791e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
11801e642812SIngo Molnar	  and slows down exception handling a tiny bit.
11815aef51c3SAndy Lutomirski
11821e642812SIngo Molnar	  If unsure, say N here.
11835aef51c3SAndy Lutomirski
11845aef51c3SAndy Lutomirskiconfig VM86
11855aef51c3SAndy Lutomirski	bool
11865aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
118734273f41SH. Peter Anvin
118834273f41SH. Peter Anvinconfig X86_16BIT
118934273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
119034273f41SH. Peter Anvin	default y
1191a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1192a7f7f624SMasahiro Yamada	help
119334273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
119434273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
119534273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
119634273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
119734273f41SH. Peter Anvin
119834273f41SH. Peter Anvinconfig X86_ESPFIX32
119934273f41SH. Peter Anvin	def_bool y
120034273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1201506f1d07SSam Ravnborg
1202197725deSH. Peter Anvinconfig X86_ESPFIX64
1203197725deSH. Peter Anvin	def_bool y
120434273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1205506f1d07SSam Ravnborg
12061ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12071ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12081ad83c85SAndy Lutomirski	default y
12091ad83c85SAndy Lutomirski	depends on X86_64
1210a7f7f624SMasahiro Yamada	help
12111ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12121ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12131ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12141ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12151ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12161ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12171ad83c85SAndy Lutomirski
12181ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12191ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12201ad83c85SAndy Lutomirski
12211ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12221ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12231ad83c85SAndy Lutomirski
1224111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1225111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1226a24ca997SThomas Gleixner	default y
1227a7f7f624SMasahiro Yamada	help
1228111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1229111e7b15SThomas Gleixner	  for legacy applications.
1230111e7b15SThomas Gleixner
1231c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1232c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1233c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1234c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1235c8137aceSThomas Gleixner	  modules.
1236c8137aceSThomas Gleixner
1237c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1238c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1239a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1240a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1241c8137aceSThomas Gleixner
1242506f1d07SSam Ravnborgconfig TOSHIBA
1243506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1244506f1d07SSam Ravnborg	depends on X86_32
1245a7f7f624SMasahiro Yamada	help
1246506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1247506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1249506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1250506f1d07SSam Ravnborg
1251506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1252506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1253506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1254506f1d07SSam Ravnborg
1255506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1256506f1d07SSam Ravnborg	  Say N otherwise.
1257506f1d07SSam Ravnborg
1258506f1d07SSam Ravnborgconfig I8K
1259039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1260949a9d70SJean Delvare	select HWMON
1261039ae585SPali Rohár	select SENSORS_DELL_SMM
1262a7f7f624SMasahiro Yamada	help
1263039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1264039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1266039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1268039ae585SPali Rohár	  needed userspace package i8kutils.
1269506f1d07SSam Ravnborg
1270039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1271039ae585SPali Rohár	  use userspace package i8kutils.
1272506f1d07SSam Ravnborg	  Say N otherwise.
1273506f1d07SSam Ravnborg
1274506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12759ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12769ba16087SJan Beulich	depends on X86_32
1277a7f7f624SMasahiro Yamada	help
1278506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1279506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1280506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1281506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1282506f1d07SSam Ravnborg	  system.
1283506f1d07SSam Ravnborg
1284506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12855e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1286506f1d07SSam Ravnborg
1287506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1288506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1289506f1d07SSam Ravnborg	  Say N otherwise.
1290506f1d07SSam Ravnborg
1291506f1d07SSam Ravnborgconfig MICROCODE
12929a2bc335SBorislav Petkov	bool "CPU microcode loading support"
12939a2bc335SBorislav Petkov	default y
129480030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1295a7f7f624SMasahiro Yamada	help
1296506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
12975f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
12985f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
12995f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13005f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13015f9c01aaSBorislav Petkov	  the Linux kernel.
1302506f1d07SSam Ravnborg
13035f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1304cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13055f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13065f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1307506f1d07SSam Ravnborg
1308c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1309c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1310c508c46eSBenjamin Gilbert	  config option.
1311506f1d07SSam Ravnborg
13128d86f390SPeter Orubaconfig MICROCODE_INTEL
1313e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13148d86f390SPeter Oruba	depends on MICROCODE
13158d86f390SPeter Oruba	default MICROCODE
1316a7f7f624SMasahiro Yamada	help
13178d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13188d86f390SPeter Oruba	  processors.
13198d86f390SPeter Oruba
1320b8989db9SAlan	  For the current Intel microcode data package go to
1321b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1322b8989db9SAlan	  'Linux Processor Microcode Data File'.
13238d86f390SPeter Oruba
132480cc9f10SPeter Orubaconfig MICROCODE_AMD
1325e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
132680cc9f10SPeter Oruba	depends on MICROCODE
1327a7f7f624SMasahiro Yamada	help
132880cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
132980cc9f10SPeter Oruba	  processors will be enabled.
133080cc9f10SPeter Oruba
1331506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1332c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1333c02f48e0SBorislav Petkov	default n
1334506f1d07SSam Ravnborg	depends on MICROCODE
1335a7f7f624SMasahiro Yamada	help
1336c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1337c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1338c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1339c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1340c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1341cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1342506f1d07SSam Ravnborg
1343506f1d07SSam Ravnborgconfig X86_MSR
1344506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1345a7f7f624SMasahiro Yamada	help
1346506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1347506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1348506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1349506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1350506f1d07SSam Ravnborg	  systems.
1351506f1d07SSam Ravnborg
1352506f1d07SSam Ravnborgconfig X86_CPUID
1353506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1354a7f7f624SMasahiro Yamada	help
1355506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1356506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1357506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1358506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1359506f1d07SSam Ravnborg
1360506f1d07SSam Ravnborgchoice
1361506f1d07SSam Ravnborg	prompt "High Memory Support"
13626fc108a0SJan Beulich	default HIGHMEM4G
1363506f1d07SSam Ravnborg	depends on X86_32
1364506f1d07SSam Ravnborg
1365506f1d07SSam Ravnborgconfig NOHIGHMEM
1366506f1d07SSam Ravnborg	bool "off"
1367a7f7f624SMasahiro Yamada	help
1368506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1369506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1370506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1371506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1372506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1373506f1d07SSam Ravnborg	  "high memory".
1374506f1d07SSam Ravnborg
1375506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1376506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1377506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1378506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1379506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1380506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1381506f1d07SSam Ravnborg	  possible.
1382506f1d07SSam Ravnborg
1383506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1384506f1d07SSam Ravnborg	  answer "4GB" here.
1385506f1d07SSam Ravnborg
1386506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1387506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1388506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1389506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1390506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1391506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1392506f1d07SSam Ravnborg
1393506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1394506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1395506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1396506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1397506f1d07SSam Ravnborg	  kernel at boot time.)
1398506f1d07SSam Ravnborg
1399506f1d07SSam Ravnborg	  If unsure, say "off".
1400506f1d07SSam Ravnborg
1401506f1d07SSam Ravnborgconfig HIGHMEM4G
1402506f1d07SSam Ravnborg	bool "4GB"
1403a7f7f624SMasahiro Yamada	help
1404506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1405506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborgconfig HIGHMEM64G
1408506f1d07SSam Ravnborg	bool "64GB"
14090ef3439cSMaciej W. Rozycki	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1410506f1d07SSam Ravnborg	select X86_PAE
1411a7f7f624SMasahiro Yamada	help
1412506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1413506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgendchoice
1416506f1d07SSam Ravnborg
1417506f1d07SSam Ravnborgchoice
14186a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1419506f1d07SSam Ravnborg	default VMSPLIT_3G
1420506f1d07SSam Ravnborg	depends on X86_32
1421a7f7f624SMasahiro Yamada	help
1422506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1425506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1426506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1427506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1428506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1429506f1d07SSam Ravnborg	  available to user programs, making the address space there
1430506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1431506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1432506f1d07SSam Ravnborg	  kernel modules.
1433506f1d07SSam Ravnborg
1434506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1435506f1d07SSam Ravnborg	  option alone!
1436506f1d07SSam Ravnborg
1437506f1d07SSam Ravnborg	config VMSPLIT_3G
1438506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1439506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1440506f1d07SSam Ravnborg		depends on !X86_PAE
1441506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1442506f1d07SSam Ravnborg	config VMSPLIT_2G
1443506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1444506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1445506f1d07SSam Ravnborg		depends on !X86_PAE
1446506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1447506f1d07SSam Ravnborg	config VMSPLIT_1G
1448506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1449506f1d07SSam Ravnborgendchoice
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborgconfig PAGE_OFFSET
1452506f1d07SSam Ravnborg	hex
1453506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1454506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1455506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1456506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1457506f1d07SSam Ravnborg	default 0xC0000000
1458506f1d07SSam Ravnborg	depends on X86_32
1459506f1d07SSam Ravnborg
1460506f1d07SSam Ravnborgconfig HIGHMEM
14613c2362e6SHarvey Harrison	def_bool y
1462506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1463506f1d07SSam Ravnborg
1464506f1d07SSam Ravnborgconfig X86_PAE
14659ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1466506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1467d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14689d99c712SChristian Melki	select SWIOTLB
1469a7f7f624SMasahiro Yamada	help
1470506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1471506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1472506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1473506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1474506f1d07SSam Ravnborg
147577ef56e4SKirill A. Shutemovconfig X86_5LEVEL
147677ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
147718ec1eafSKirill A. Shutemov	default y
1478eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1479162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
148077ef56e4SKirill A. Shutemov	depends on X86_64
1481a7f7f624SMasahiro Yamada	help
148277ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
148377ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
148477ef56e4SKirill A. Shutemov	  physical address space.
148577ef56e4SKirill A. Shutemov
148677ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
148777ef56e4SKirill A. Shutemov
14886657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
14896657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
149077ef56e4SKirill A. Shutemov
1491cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
149277ef56e4SKirill A. Shutemov	  information.
149377ef56e4SKirill A. Shutemov
149477ef56e4SKirill A. Shutemov	  Say N if unsure.
149577ef56e4SKirill A. Shutemov
149610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1497e5008abeSLuis R. Rodriguez	def_bool y
14982e1da13fSVlastimil Babka	depends on X86_64
1499a7f7f624SMasahiro Yamada	help
150010971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
150110971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
150210971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
150310971ab2SIngo Molnar	  that we have them enabled.
15049e899816SNick Piggin
15055c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15065c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15075c280cf6SThomas Gleixner	depends on DEBUG_FS
1508a7f7f624SMasahiro Yamada	help
1509b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1510a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15115c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15125c280cf6SThomas Gleixner
15137744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15147744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15157744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
151682fef0adSDavid Rientjes	select DMA_COHERENT_POOL
151794d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1518ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15199087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1520597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
152122916417STom Lendacky	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1522a7f7f624SMasahiro Yamada	help
15237744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15247744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15257744ccdbSTom Lendacky	  Encryption (SME).
15267744ccdbSTom Lendacky
15277744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15287744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15297744ccdbSTom Lendacky	default y
15307744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1531a7f7f624SMasahiro Yamada	help
15327744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15337744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15347744ccdbSTom Lendacky
15357744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15367744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15377744ccdbSTom Lendacky
15387744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15397744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15407744ccdbSTom Lendacky
1541506f1d07SSam Ravnborg# Common NUMA Features
1542506f1d07SSam Ravnborgconfig NUMA
1543e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1544506f1d07SSam Ravnborg	depends on SMP
1545b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1546b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1547a7f7f624SMasahiro Yamada	help
1548e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1549fd51b2d7SKOSAKI Motohiro
1550506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1551506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1552506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1553506f1d07SSam Ravnborg
1554c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1555fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1556fd51b2d7SKOSAKI Motohiro
1557b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15587cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1559fd51b2d7SKOSAKI Motohiro
1560fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1561506f1d07SSam Ravnborg
1562eec1d4faSHans Rosenfeldconfig AMD_NUMA
15633c2362e6SHarvey Harrison	def_bool y
15643c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15655da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1566a7f7f624SMasahiro Yamada	help
1567eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1568eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1569eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1570eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1571eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1572506f1d07SSam Ravnborg
1573506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15743c2362e6SHarvey Harrison	def_bool y
15753c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1576506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1577506f1d07SSam Ravnborg	select ACPI_NUMA
1578a7f7f624SMasahiro Yamada	help
1579506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1580506f1d07SSam Ravnborg
1581506f1d07SSam Ravnborgconfig NUMA_EMU
1582506f1d07SSam Ravnborg	bool "NUMA emulation"
15831b7e03efSTejun Heo	depends on NUMA
1584a7f7f624SMasahiro Yamada	help
1585506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1586506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1587506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1588506f1d07SSam Ravnborg
1589506f1d07SSam Ravnborgconfig NODES_SHIFT
1590d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
159151591e31SDavid Rientjes	range 1 10
159251591e31SDavid Rientjes	default "10" if MAXSMP
1593506f1d07SSam Ravnborg	default "6" if X86_64
1594506f1d07SSam Ravnborg	default "3"
1595a9ee6cf5SMike Rapoport	depends on NUMA
1596a7f7f624SMasahiro Yamada	help
15971184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1598692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1601506f1d07SSam Ravnborg	def_bool y
16023b16651fSTejun Heo	depends on X86_32 && !NUMA
1603506f1d07SSam Ravnborg
1604506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1605506f1d07SSam Ravnborg	def_bool y
16066ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1607506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1608506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1609506f1d07SSam Ravnborg
16103b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16116ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16123b16651fSTejun Heo
1613506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1614506f1d07SSam Ravnborg	def_bool y
1615b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1616506f1d07SSam Ravnborg
1617506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1618a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16193120e25eSJan Beulich	depends on X86_64 && MEMORY_HOTPLUG
1620a0842b70SToshi Kani	help
1621a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1622cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1623a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1624506f1d07SSam Ravnborg
16253b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16263b16651fSTejun Heo	def_bool y
16273b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16283b16651fSTejun Heo
1629a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1630a29815a3SAvi Kivity	hex
1631a29815a3SAvi Kivity	default 0 if X86_32
1632a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1633a29815a3SAvi Kivity
16347a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16357a67832cSDan Williams	bool
16367a67832cSDan Williams
1637ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16387a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16399f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16409f53f9faSDan Williams	depends on BLK_DEV
16417a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16427b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16439f53f9faSDan Williams	select LIBNVDIMM
1644ec776ef6SChristoph Hellwig	help
1645ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1646ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1647ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1648ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1649ec776ef6SChristoph Hellwig
1650ec776ef6SChristoph Hellwig	  Say Y if unsure.
1651ec776ef6SChristoph Hellwig
1652506f1d07SSam Ravnborgconfig HIGHPTE
1653506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16546fc108a0SJan Beulich	depends on HIGHMEM
1655a7f7f624SMasahiro Yamada	help
1656506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1657506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1658506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1659506f1d07SSam Ravnborg	  entries in high memory.
1660506f1d07SSam Ravnborg
16619f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16629f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1663a7f7f624SMasahiro Yamada	help
16649f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16659f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16669f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16679f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16689f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16699f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16709f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16718c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16729f077871SJeremy Fitzhardinge
16739f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16749f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16759f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16769f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16779f077871SJeremy Fitzhardinge
16789f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16799f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16809f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
16819f077871SJeremy Fitzhardinge	  memory.
16829f077871SJeremy Fitzhardinge
1683c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1684c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1685c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1686c885df50SJeremy Fitzhardinge	default y
1687a7f7f624SMasahiro Yamada	help
1688c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1689c885df50SJeremy Fitzhardinge	  on or off.
1690c885df50SJeremy Fitzhardinge
1691506f1d07SSam Ravnborgconfig MATH_EMULATION
1692506f1d07SSam Ravnborg	bool
1693a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
169487d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1695a7f7f624SMasahiro Yamada	help
1696506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1697506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1698506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1699506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1700506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1701506f1d07SSam Ravnborg	  coprocessor or this emulation.
1702506f1d07SSam Ravnborg
1703506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1704506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1705506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1706506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1707506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1708506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1709506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1710506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1711506f1d07SSam Ravnborg
1712506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1713506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1714506f1d07SSam Ravnborg
1715506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1716506f1d07SSam Ravnborg	  kernel, it won't hurt.
1717506f1d07SSam Ravnborg
1718506f1d07SSam Ravnborgconfig MTRR
17196fc108a0SJan Beulich	def_bool y
17206a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1721a7f7f624SMasahiro Yamada	help
1722506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1723506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1724506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1725506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1726506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1727506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1728506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1729506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1730506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1731506f1d07SSam Ravnborg
1732506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1733506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1734506f1d07SSam Ravnborg	  as well:
1735506f1d07SSam Ravnborg
1736506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1737506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1738506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1739506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1740506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1741506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1742506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1745506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1746506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1747506f1d07SSam Ravnborg
1748506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1749506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1750506f1d07SSam Ravnborg
1751cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1752506f1d07SSam Ravnborg
175395ffa243SYinghai Luconfig MTRR_SANITIZER
17542ffb3501SYinghai Lu	def_bool y
175595ffa243SYinghai Lu	prompt "MTRR cleanup support"
175695ffa243SYinghai Lu	depends on MTRR
1757a7f7f624SMasahiro Yamada	help
1758aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1759aba3728cSThomas Gleixner	  add writeback entries.
176095ffa243SYinghai Lu
1761aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1762692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1763aba3728cSThomas Gleixner	  mtrr_chunk_size.
176495ffa243SYinghai Lu
17652ffb3501SYinghai Lu	  If unsure, say Y.
176695ffa243SYinghai Lu
176795ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1768f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1769f5098d62SYinghai Lu	range 0 1
1770f5098d62SYinghai Lu	default "0"
177195ffa243SYinghai Lu	depends on MTRR_SANITIZER
1772a7f7f624SMasahiro Yamada	help
1773f5098d62SYinghai Lu	  Enable mtrr cleanup default value
177495ffa243SYinghai Lu
177512031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
177612031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
177712031a62SYinghai Lu	range 0 7
177812031a62SYinghai Lu	default "1"
177912031a62SYinghai Lu	depends on MTRR_SANITIZER
1780a7f7f624SMasahiro Yamada	help
178112031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1782aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
178312031a62SYinghai Lu
17842e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
17856fc108a0SJan Beulich	def_bool y
17866a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
17872a8a2719SIngo Molnar	depends on MTRR
1788a7f7f624SMasahiro Yamada	help
17892e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1790042b78e4SVenki Pallipadi
17912e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
17922e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
17932e5d9c85Svenkatesh.pallipadi@intel.com
17942e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1795042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
17962e5d9c85Svenkatesh.pallipadi@intel.com
17972e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
17982e5d9c85Svenkatesh.pallipadi@intel.com
179946cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
180046cf98cdSVenkatesh Pallipadi	def_bool y
180146cf98cdSVenkatesh Pallipadi	depends on X86_PAT
180246cf98cdSVenkatesh Pallipadi
1803628c6246SH. Peter Anvinconfig ARCH_RANDOM
1804628c6246SH. Peter Anvin	def_bool y
1805628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1806a7f7f624SMasahiro Yamada	help
1807628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1808628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1809628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1810628c6246SH. Peter Anvin	  secure hardware random number generator.
1811628c6246SH. Peter Anvin
181251ae4a2dSH. Peter Anvinconfig X86_SMAP
181351ae4a2dSH. Peter Anvin	def_bool y
181451ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1815a7f7f624SMasahiro Yamada	help
181651ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
181751ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
181851ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
181951ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
182051ae4a2dSH. Peter Anvin
182151ae4a2dSH. Peter Anvin	  If unsure, say Y.
182251ae4a2dSH. Peter Anvin
1823b971880fSBabu Mogerconfig X86_UMIP
1824796ebc81SRicardo Neri	def_bool y
1825b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1826a7f7f624SMasahiro Yamada	help
1827b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1828b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1829b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1830b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1831b971880fSBabu Moger	  information about the hardware state.
1832796ebc81SRicardo Neri
1833796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1834796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1835796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1836796ebc81SRicardo Neri	  results are dummy.
1837aa35f896SRicardo Neri
183835e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
183938f3e775SBabu Moger	prompt "Memory Protection Keys"
184035e97790SDave Hansen	def_bool y
1841284244a9SDave Hansen	# Note: only available in 64-bit mode
184238f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
184352c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
184452c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1845a7f7f624SMasahiro Yamada	help
1846284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1847284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1848284244a9SDave Hansen	  page tables when an application changes protection domains.
1849284244a9SDave Hansen
18501eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1851284244a9SDave Hansen
1852284244a9SDave Hansen	  If unsure, say y.
185335e97790SDave Hansen
1854db616173SMichal Hockochoice
1855db616173SMichal Hocko	prompt "TSX enable mode"
1856db616173SMichal Hocko	depends on CPU_SUP_INTEL
1857db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1858db616173SMichal Hocko	help
1859db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1860db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1861db616173SMichal Hocko	  can lead to a noticeable performance boost.
1862db616173SMichal Hocko
1863db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1864db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1865db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1866db616173SMichal Hocko
1867db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1868db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1869db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1870db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1871db616173SMichal Hocko	  for the particular machine.
1872db616173SMichal Hocko
1873db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1874db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1875db616173SMichal Hocko	  details.
1876db616173SMichal Hocko
1877db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1878db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1879db616173SMichal Hocko	  relevant.
1880db616173SMichal Hocko
1881db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1882db616173SMichal Hocko	bool "off"
1883db616173SMichal Hocko	help
1884db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1885db616173SMichal Hocko
1886db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1887db616173SMichal Hocko	bool "on"
1888db616173SMichal Hocko	help
1889db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1890db616173SMichal Hocko	  line parameter.
1891db616173SMichal Hocko
1892db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1893db616173SMichal Hocko	bool "auto"
1894db616173SMichal Hocko	help
1895db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1896db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1897db616173SMichal Hockoendchoice
1898db616173SMichal Hocko
1899e7e05452SSean Christophersonconfig X86_SGX
1900e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1901e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1902e7e05452SSean Christopherson	depends on CRYPTO=y
1903e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1904e7e05452SSean Christopherson	select SRCU
1905e7e05452SSean Christopherson	select MMU_NOTIFIER
1906901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
1907e7e05452SSean Christopherson	help
1908e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1909e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1910e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1911e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1912e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1913e7e05452SSean Christopherson	  hardware.
1914e7e05452SSean Christopherson
1915e7e05452SSean Christopherson	  If unsure, say N.
1916e7e05452SSean Christopherson
1917506f1d07SSam Ravnborgconfig EFI
19189ba16087SJan Beulich	bool "EFI runtime service support"
19195b83683fSHuang, Ying	depends on ACPI
1920f6ce5002SSergey Vlasov	select UCS2_STRING
1921022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1922a7f7f624SMasahiro Yamada	help
19238b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1924506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1925506f1d07SSam Ravnborg
19268b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19278b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19288b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19298b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19308b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19318b2cb7a8SHuang, Ying	  platforms.
1932506f1d07SSam Ravnborg
1933291f3632SMatt Flemingconfig EFI_STUB
1934291f3632SMatt Fleming	bool "EFI stub support"
1935b16d8c23SMatt Fleming	depends on EFI && !X86_USE_3DNOW
19368f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19377b2a583aSMatt Fleming	select RELOCATABLE
1938a7f7f624SMasahiro Yamada	help
1939291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1940291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1941291f3632SMatt Fleming
19424f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19430c759662SMatt Fleming
19447d453eeeSMatt Flemingconfig EFI_MIXED
19457d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19467d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1947a7f7f624SMasahiro Yamada	help
19487d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19497d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19507d453eeeSMatt Fleming	   mode.
19517d453eeeSMatt Fleming
19527d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19537d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19547d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19557d453eeeSMatt Fleming
19567d453eeeSMatt Fleming	   If unsure, say N.
19577d453eeeSMatt Fleming
19588636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1959506f1d07SSam Ravnborg
1960506f1d07SSam Ravnborgconfig KEXEC
1961506f1d07SSam Ravnborg	bool "kexec system call"
19622965faa5SDave Young	select KEXEC_CORE
1963a7f7f624SMasahiro Yamada	help
1964506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1965506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1966506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1967506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1968506f1d07SSam Ravnborg
1969506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1970506f1d07SSam Ravnborg
1971506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1972506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1973bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1974bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
1975bf220695SGeert Uytterhoeven	  made.
1976506f1d07SSam Ravnborg
197774ca317cSVivek Goyalconfig KEXEC_FILE
197874ca317cSVivek Goyal	bool "kexec file based system call"
19792965faa5SDave Young	select KEXEC_CORE
198074ca317cSVivek Goyal	select BUILD_BIN2C
198174ca317cSVivek Goyal	depends on X86_64
198274ca317cSVivek Goyal	depends on CRYPTO=y
198374ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
1984a7f7f624SMasahiro Yamada	help
198574ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
198674ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
198774ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
198874ca317cSVivek Goyal	  accepted by previous system call.
198974ca317cSVivek Goyal
1990b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
1991b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
1992b799a09fSAKASHI Takahiro
199399d5cadfSJiri Bohacconfig KEXEC_SIG
19948e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
199574ca317cSVivek Goyal	depends on KEXEC_FILE
1996a7f7f624SMasahiro Yamada	help
199799d5cadfSJiri Bohac
199899d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
199999d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
200099d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
200199d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
200299d5cadfSJiri Bohac
200399d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
200499d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
200599d5cadfSJiri Bohac	  loaded in order for this to work.
200699d5cadfSJiri Bohac
200799d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
200899d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
200999d5cadfSJiri Bohac	depends on KEXEC_SIG
2010a7f7f624SMasahiro Yamada	help
20118e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2012d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20138e7d8381SVivek Goyal
20148e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20158e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
201699d5cadfSJiri Bohac	depends on KEXEC_SIG
20178e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20188e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2019a7f7f624SMasahiro Yamada	help
20208e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20218e7d8381SVivek Goyal
2022506f1d07SSam Ravnborgconfig CRASH_DUMP
202304b69447SPavel Machek	bool "kernel crash dumps"
2024506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2025a7f7f624SMasahiro Yamada	help
2026506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2027506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2028506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2029506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2030506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2031506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2032506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2033506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2034330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2035506f1d07SSam Ravnborg
20363ab83521SHuang Yingconfig KEXEC_JUMP
20376ea30386SKees Cook	bool "kexec jump"
2038fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2039a7f7f624SMasahiro Yamada	help
204089081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
204189081d17SHuang Ying	  code in physical address mode via KEXEC
20423ab83521SHuang Ying
2043506f1d07SSam Ravnborgconfig PHYSICAL_START
20446a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2045ceefccc9SH. Peter Anvin	default "0x1000000"
2046a7f7f624SMasahiro Yamada	help
2047506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2048506f1d07SSam Ravnborg
2049506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2050506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2051506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2052506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2053506f1d07SSam Ravnborg	  address.
2054506f1d07SSam Ravnborg
2055506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2056506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2057506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2058506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2059506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2060506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2061506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2062506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2063506f1d07SSam Ravnborg
2064ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2065ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2066ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2067ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2068ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2069ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2070ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2071330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2072ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2073506f1d07SSam Ravnborg
2074506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2075506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2076506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2077506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2078506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2079506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2080506f1d07SSam Ravnborg	  line.
2081506f1d07SSam Ravnborg
2082506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2083506f1d07SSam Ravnborg
2084506f1d07SSam Ravnborgconfig RELOCATABLE
208526717808SH. Peter Anvin	bool "Build a relocatable kernel"
208626717808SH. Peter Anvin	default y
2087a7f7f624SMasahiro Yamada	help
2088506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2089506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2090506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2091506f1d07SSam Ravnborg	  but are discarded at runtime.
2092506f1d07SSam Ravnborg
2093506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2094506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2095506f1d07SSam Ravnborg	  kernel.
2096506f1d07SSam Ravnborg
2097506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2098506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
20998ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2100506f1d07SSam Ravnborg
21018ab3820fSKees Cookconfig RANDOMIZE_BASE
2102e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21038ab3820fSKees Cook	depends on RELOCATABLE
21046807c846SIngo Molnar	default y
2105a7f7f624SMasahiro Yamada	help
2106e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2107e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2108e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2109e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2110e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2111e8581e3dSBaoquan He	  code internals.
2112e8581e3dSBaoquan He
2113ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2114ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2115ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2116ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2117ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2118ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2119ed9f007eSKees Cook
2120ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2121ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2122ed9f007eSKees Cook	  512MB (8 bits of entropy).
21238ab3820fSKees Cook
2124a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2125e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2126e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2127ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2128ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2129ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2130ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2131ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2132ed9f007eSKees Cook	  limited due to memory layouts.
2133e8581e3dSBaoquan He
21346807c846SIngo Molnar	  If unsure, say Y.
2135da2b6fb9SKees Cook
21368ab3820fSKees Cook# Relocation on x86 needs some additional build support
2137845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2138845adf72SH. Peter Anvin	def_bool y
21398ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2140845adf72SH. Peter Anvin
2141506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2142a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21438ab3820fSKees Cook	default "0x200000"
2144a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2145a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2146a7f7f624SMasahiro Yamada	help
2147506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2148506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2149506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2150506f1d07SSam Ravnborg
2151506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2152506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2153506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2154506f1d07SSam Ravnborg
2155506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2156506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2157506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2158506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2159506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2160506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2161506f1d07SSam Ravnborg	  above alignment restrictions.
2162506f1d07SSam Ravnborg
2163a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2164a0215061SKees Cook	  this value must be a multiple of 0x200000.
2165a0215061SKees Cook
2166506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2167506f1d07SSam Ravnborg
2168eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2169eedb92abSKirill A. Shutemov	bool
2170a7f7f624SMasahiro Yamada	help
2171eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2172eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2173eedb92abSKirill A. Shutemov
21740483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
21750483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
21760483e1faSThomas Garnier	depends on X86_64
21770483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2178eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
21790483e1faSThomas Garnier	default RANDOMIZE_BASE
2180a7f7f624SMasahiro Yamada	help
21810483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
21820483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
21830483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
21840483e1faSThomas Garnier
21850483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
21860483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
21870483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
21880483e1faSThomas Garnier	   addresses for each memory section.
21890483e1faSThomas Garnier
21906807c846SIngo Molnar	   If unsure, say Y.
21910483e1faSThomas Garnier
219290397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
219390397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
219490397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
219590397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
219690397a41SThomas Garnier	default "0x0"
219790397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
219890397a41SThomas Garnier	range 0x0 0x40
2199a7f7f624SMasahiro Yamada	help
220090397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
220190397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
220290397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
220390397a41SThomas Garnier	   address randomization.
220490397a41SThomas Garnier
220590397a41SThomas Garnier	   If unsure, leave at the default value.
220690397a41SThomas Garnier
2207506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2208bebd024eSThomas Gleixner	def_bool y
220940b31360SStephen Rothwell	depends on SMP
2210506f1d07SSam Ravnborg
221180aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
221280aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22132c922cd0SKees Cook	depends on HOTPLUG_CPU
2214a7f7f624SMasahiro Yamada	help
221580aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
221680aa1dffSFenghua Yu
221780aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
221880aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
221980aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
222080aa1dffSFenghua Yu
222180aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
222280aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
222380aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
222480aa1dffSFenghua Yu
222580aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
222680aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
222780aa1dffSFenghua Yu
222880aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
222980aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
223080aa1dffSFenghua Yu	  be other CPU0 dependencies.
223180aa1dffSFenghua Yu
223280aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
223380aa1dffSFenghua Yu	  you enable this feature.
223480aa1dffSFenghua Yu
223580aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
223680aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
223780aa1dffSFenghua Yu	  parameter cpu0_hotplug.
223880aa1dffSFenghua Yu
2239a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2240a71c8bc5SFenghua Yu	def_bool n
2241a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22422c922cd0SKees Cook	depends on HOTPLUG_CPU
2243a7f7f624SMasahiro Yamada	help
2244a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2245a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2246a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2247a71c8bc5SFenghua Yu
2248a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2249a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2250a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2251a71c8bc5SFenghua Yu
2252a71c8bc5SFenghua Yu	  If unsure, say N.
2253a71c8bc5SFenghua Yu
2254506f1d07SSam Ravnborgconfig COMPAT_VDSO
2255b0b49f26SAndy Lutomirski	def_bool n
2256b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2257953fee1dSIngo Molnar	depends on COMPAT_32
2258a7f7f624SMasahiro Yamada	help
2259b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2260b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2261b0b49f26SAndy Lutomirski	  indicated in its segment table.
2262e84446deSRandy Dunlap
2263b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2264b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2265b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2266b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2267b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2268506f1d07SSam Ravnborg
2269b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2270b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2271b0b49f26SAndy Lutomirski
2272b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2273b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2274b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2275b0b49f26SAndy Lutomirski
2276b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2277b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2278506f1d07SSam Ravnborg
22793dc33bd3SKees Cookchoice
22803dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
22813dc33bd3SKees Cook	depends on X86_64
2282625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
22833dc33bd3SKees Cook	help
22843dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
22853dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
22863dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
22873dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
22883dc33bd3SKees Cook
22893dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2290bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
22913dc33bd3SKees Cook
22923dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
22933dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
22943dc33bd3SKees Cook	  to improve security.
22953dc33bd3SKees Cook
2296bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
22973dc33bd3SKees Cook
22983dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2299bd49e16eSAndy Lutomirski		bool "Full emulation"
23003dc33bd3SKees Cook		help
2301bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2302bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2303bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2304bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2305bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2306bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2307bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2308bd49e16eSAndy Lutomirski
2309bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2310bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2311bd49e16eSAndy Lutomirski
2312bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2313bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2314bd49e16eSAndy Lutomirski		help
2315bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2316bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2317bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2318bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2319bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2320bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2321bd49e16eSAndy Lutomirski		  buffer.
23223dc33bd3SKees Cook
23233dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23243dc33bd3SKees Cook		bool "None"
23253dc33bd3SKees Cook		help
23263dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23273dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23283dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23293dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23303dc33bd3SKees Cook		  malicious userspace programs can be identified.
23313dc33bd3SKees Cook
23323dc33bd3SKees Cookendchoice
23333dc33bd3SKees Cook
2334516cbf37STim Birdconfig CMDLINE_BOOL
2335516cbf37STim Bird	bool "Built-in kernel command line"
2336a7f7f624SMasahiro Yamada	help
2337516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2338516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2339516cbf37STim Bird	  necessary or convenient to provide some or all of the
2340516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2341516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2342516cbf37STim Bird
2343516cbf37STim Bird	  To compile command line arguments into the kernel,
2344516cbf37STim Bird	  set this option to 'Y', then fill in the
234569711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2346516cbf37STim Bird
2347516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2348516cbf37STim Bird	  should leave this option set to 'N'.
2349516cbf37STim Bird
2350516cbf37STim Birdconfig CMDLINE
2351516cbf37STim Bird	string "Built-in kernel command string"
2352516cbf37STim Bird	depends on CMDLINE_BOOL
2353516cbf37STim Bird	default ""
2354a7f7f624SMasahiro Yamada	help
2355516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2356516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2357516cbf37STim Bird	  command line at boot time, it is appended to this string to
2358516cbf37STim Bird	  form the full kernel command line, when the system boots.
2359516cbf37STim Bird
2360516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2361516cbf37STim Bird	  change this behavior.
2362516cbf37STim Bird
2363516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2364516cbf37STim Bird	  by the boot loader) should specify the device for the root
2365516cbf37STim Bird	  file system.
2366516cbf37STim Bird
2367516cbf37STim Birdconfig CMDLINE_OVERRIDE
2368516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2369645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2370a7f7f624SMasahiro Yamada	help
2371516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2372516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2373516cbf37STim Bird
2374516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2375516cbf37STim Bird	  be set to 'N' under normal conditions.
2376516cbf37STim Bird
2377a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2378a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2379a5b9e5a2SAndy Lutomirski	default y
2380a7f7f624SMasahiro Yamada	help
2381a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2382a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2383a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2384a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2385a5b9e5a2SAndy Lutomirski	  threading libraries.
2386a5b9e5a2SAndy Lutomirski
2387a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2388a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2389a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2390a5b9e5a2SAndy Lutomirski
2391a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2392a5b9e5a2SAndy Lutomirski
2393b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2394b700e7f0SSeth Jennings
2395506f1d07SSam Ravnborgendmenu
2396506f1d07SSam Ravnborg
23973072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
23983072e413SMichal Hocko	def_bool y
23993072e413SMichal Hocko	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
24003072e413SMichal Hocko
2401f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2402f91ef222SOscar Salvador	def_bool y
2403f91ef222SOscar Salvador
2404e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2405645a7919STejun Heo	def_bool y
2406e534c7c5SLee Schermerhorn	depends on NUMA
2407e534c7c5SLee Schermerhorn
2408da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2409e279b6c1SSam Ravnborg
2410e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24113c2362e6SHarvey Harrison	def_bool y
241244556530SZhimin Gu	depends on HIBERNATION
2413e279b6c1SSam Ravnborg
2414e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2415e279b6c1SSam Ravnborg
2416e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2417e279b6c1SSam Ravnborg
2418a6b68076SAndi Kleenconfig X86_APM_BOOT
24196fc108a0SJan Beulich	def_bool y
2420282e5aabSPaul Bolle	depends on APM
2421a6b68076SAndi Kleen
2422e279b6c1SSam Ravnborgmenuconfig APM
2423e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2424efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2425a7f7f624SMasahiro Yamada	help
2426e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2427e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2428e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2429e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2430e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2431e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2432e279b6c1SSam Ravnborg
2433e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2434e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2435e279b6c1SSam Ravnborg
2436e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2437e279b6c1SSam Ravnborg	  machines with more than one CPU.
2438e279b6c1SSam Ravnborg
2439e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2440151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24412dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2442e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2443e279b6c1SSam Ravnborg
2444e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2445e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2446e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2447e279b6c1SSam Ravnborg
2448e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2449e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2450e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2451e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2452e279b6c1SSam Ravnborg
2453e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2454e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2455e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2456e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2457e279b6c1SSam Ravnborg	  APM in your BIOS).
2458e279b6c1SSam Ravnborg
2459e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2460e279b6c1SSam Ravnborg	  "weird" problems:
2461e279b6c1SSam Ravnborg
2462e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2463e279b6c1SSam Ravnborg	  enabled.
2464e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2465e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2466e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2467e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2468e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2469e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2470e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2471e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2472e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2473e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2474e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2475e279b6c1SSam Ravnborg	  11) exchange RAM chips
2476e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2477e279b6c1SSam Ravnborg
2478e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2479e279b6c1SSam Ravnborg	  module will be called apm.
2480e279b6c1SSam Ravnborg
2481e279b6c1SSam Ravnborgif APM
2482e279b6c1SSam Ravnborg
2483e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2484e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2485a7f7f624SMasahiro Yamada	help
2486e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2487e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2488e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2489e279b6c1SSam Ravnborg
2490e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2491e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2492a7f7f624SMasahiro Yamada	help
2493e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2494e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2495e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2496e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2497e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2498e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2499e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2500e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2501e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2502e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2503e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2504e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2505e279b6c1SSam Ravnborg	  this feature.
2506e279b6c1SSam Ravnborg
2507e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2508dd8af076SLen Brown	depends on CPU_IDLE
2509e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2510a7f7f624SMasahiro Yamada	help
2511e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2512e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2513e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2514e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2515e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2516e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2517e279b6c1SSam Ravnborg	  this option does nothing.)
2518e279b6c1SSam Ravnborg
2519e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2520e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2521a7f7f624SMasahiro Yamada	help
2522e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2523e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2524e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2525e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2526e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2527e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2528e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2529e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2530e279b6c1SSam Ravnborg	  especially if you are using gpm.
2531e279b6c1SSam Ravnborg
2532e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2533e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2534a7f7f624SMasahiro Yamada	help
2535e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2536e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2537e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2538e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2539e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2540e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2541e279b6c1SSam Ravnborg
2542e279b6c1SSam Ravnborgendif # APM
2543e279b6c1SSam Ravnborg
2544bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2547e279b6c1SSam Ravnborg
254827471fdbSAndy Henroidsource "drivers/idle/Kconfig"
254927471fdbSAndy Henroid
2550e279b6c1SSam Ravnborgendmenu
2551e279b6c1SSam Ravnborg
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2554e279b6c1SSam Ravnborg
2555e279b6c1SSam Ravnborgchoice
2556e279b6c1SSam Ravnborg	prompt "PCI access mode"
2557efefa6f6SIngo Molnar	depends on X86_32 && PCI
2558e279b6c1SSam Ravnborg	default PCI_GOANY
2559a7f7f624SMasahiro Yamada	help
2560e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2561e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2562e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2563e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2564e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2565e279b6c1SSam Ravnborg
2566e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2567e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2568e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2569e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2570e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2571e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2572e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2573e279b6c1SSam Ravnborg
2574e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2575e279b6c1SSam Ravnborg	bool "BIOS"
2576e279b6c1SSam Ravnborg
2577e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2578e279b6c1SSam Ravnborg	bool "MMConfig"
2579e279b6c1SSam Ravnborg
2580e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2581e279b6c1SSam Ravnborg	bool "Direct"
2582e279b6c1SSam Ravnborg
25833ef0e1f8SAndres Salomonconfig PCI_GOOLPC
258476fb6570SDaniel Drake	bool "OLPC XO-1"
25853ef0e1f8SAndres Salomon	depends on OLPC
25863ef0e1f8SAndres Salomon
25872bdd1b03SAndres Salomonconfig PCI_GOANY
25882bdd1b03SAndres Salomon	bool "Any"
25892bdd1b03SAndres Salomon
2590e279b6c1SSam Ravnborgendchoice
2591e279b6c1SSam Ravnborg
2592e279b6c1SSam Ravnborgconfig PCI_BIOS
25933c2362e6SHarvey Harrison	def_bool y
2594efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2595e279b6c1SSam Ravnborg
2596e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2597e279b6c1SSam Ravnborgconfig PCI_DIRECT
25983c2362e6SHarvey Harrison	def_bool y
25990aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2600e279b6c1SSam Ravnborg
2601e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2602b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2603b45c9f36SJan Kiszka	default y
26044590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2605b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2606e279b6c1SSam Ravnborg
26073ef0e1f8SAndres Salomonconfig PCI_OLPC
26082bdd1b03SAndres Salomon	def_bool y
26092bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26103ef0e1f8SAndres Salomon
2611b5401a96SAlex Nixonconfig PCI_XEN
2612b5401a96SAlex Nixon	def_bool y
2613b5401a96SAlex Nixon	depends on PCI && XEN
2614b5401a96SAlex Nixon	select SWIOTLB_XEN
2615b5401a96SAlex Nixon
26168364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26178364e1f8SJan Kiszka	def_bool y
26188364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2619e279b6c1SSam Ravnborg
26203f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26216a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26226ea30386SKees Cook	depends on PCI
26233f6ea84aSIra W. Snyder	help
26243f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26253f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26263f6ea84aSIra W. Snyder	  not have ACPI.
26273f6ea84aSIra W. Snyder
262864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
262964a5fed6SBjorn Helgaas	  is known to be incomplete.
263064a5fed6SBjorn Helgaas
263164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
263264a5fed6SBjorn Helgaas
26333a495511SWilliam Breathitt Grayconfig ISA_BUS
263417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26353a495511SWilliam Breathitt Gray	help
263617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
263717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
263817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
263917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
264017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26413a495511SWilliam Breathitt Gray
26423a495511SWilliam Breathitt Gray	  If unsure, say N.
26433a495511SWilliam Breathitt Gray
26441c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2645e279b6c1SSam Ravnborgconfig ISA_DMA_API
26461c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26471c00f016SDavid Rientjes	default y
26481c00f016SDavid Rientjes	help
26491c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26501c00f016SDavid Rientjes	  If unsure, say Y.
2651e279b6c1SSam Ravnborg
265251e68d05SLinus Torvaldsif X86_32
265351e68d05SLinus Torvalds
2654e279b6c1SSam Ravnborgconfig ISA
2655e279b6c1SSam Ravnborg	bool "ISA support"
2656a7f7f624SMasahiro Yamada	help
2657e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2658e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2659e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2660e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2661e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2662e279b6c1SSam Ravnborg
2663e279b6c1SSam Ravnborgconfig SCx200
2664e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2665a7f7f624SMasahiro Yamada	help
2666e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2667e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2668e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2669e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2670e279b6c1SSam Ravnborg
2671e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2672e279b6c1SSam Ravnborg
2673e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2674e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2675592913ecSJohn Stultz	depends on SCx200
2676e279b6c1SSam Ravnborg	default y
2677a7f7f624SMasahiro Yamada	help
2678e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2679e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2680e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2681e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2682e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2683e279b6c1SSam Ravnborg
26843ef0e1f8SAndres Salomonconfig OLPC
26853ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
268654008979SThomas Gleixner	depends on !X86_PAE
26873c554946SAndres Salomon	select GPIOLIB
2688dc3119e7SThomas Gleixner	select OF
268945bb1674SDaniel Drake	select OF_PROMTREE
2690b4e51854SGrant Likely	select IRQ_DOMAIN
26910c3d931bSLubomir Rintel	select OLPC_EC
2692a7f7f624SMasahiro Yamada	help
26933ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
26943ef0e1f8SAndres Salomon	  XO hardware.
26953ef0e1f8SAndres Salomon
2696a3128588SDaniel Drakeconfig OLPC_XO1_PM
2697a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2698fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2699a7f7f624SMasahiro Yamada	help
270097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2701bf1ebf00SDaniel Drake
2702cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2703cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2704cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2705a7f7f624SMasahiro Yamada	help
2706cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2707cfee9597SDaniel Drake	  programmable wakeup source.
2708cfee9597SDaniel Drake
27097feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27107feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
271192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2712ed8e47feSRandy Dunlap	depends on INPUT=y
2713d8d01a63SDaniel Drake	select POWER_SUPPLY
2714a7f7f624SMasahiro Yamada	help
27157feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27167bc74b3dSDaniel Drake	   - EC-driven system wakeups
27177feda8e9SDaniel Drake	   - Power button
27187bc74b3dSDaniel Drake	   - Ebook switch
27192cf2baeaSDaniel Drake	   - Lid switch
2720e1040ac6SDaniel Drake	   - AC adapter status updates
2721e1040ac6SDaniel Drake	   - Battery status updates
27227feda8e9SDaniel Drake
2723a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2724a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2725d8d01a63SDaniel Drake	depends on OLPC && ACPI
2726d8d01a63SDaniel Drake	select POWER_SUPPLY
2727a7f7f624SMasahiro Yamada	help
2728a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2729a0f30f59SDaniel Drake	   - EC-driven system wakeups
2730a0f30f59SDaniel Drake	   - AC adapter status updates
2731a0f30f59SDaniel Drake	   - Battery status updates
2732e279b6c1SSam Ravnborg
2733d4f3e350SEd Wildgooseconfig ALIX
2734d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2735d4f3e350SEd Wildgoose	select GPIOLIB
2736a7f7f624SMasahiro Yamada	help
2737d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2738d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2739d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2740d4f3e350SEd Wildgoose	  get added here.
2741d4f3e350SEd Wildgoose
2742d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2743d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2744d4f3e350SEd Wildgoose
2745d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2746d4f3e350SEd Wildgoose
2747da4e3302SPhilip Prindevilleconfig NET5501
2748da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2749da4e3302SPhilip Prindeville	select GPIOLIB
2750a7f7f624SMasahiro Yamada	help
2751da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2752da4e3302SPhilip Prindeville
27533197059aSPhilip A. Prindevilleconfig GEOS
27543197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27553197059aSPhilip A. Prindeville	select GPIOLIB
27563197059aSPhilip A. Prindeville	depends on DMI
2757a7f7f624SMasahiro Yamada	help
27583197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27593197059aSPhilip A. Prindeville
27607d029125SVivien Didelotconfig TS5500
27617d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
27627d029125SVivien Didelot	depends on MELAN
27637d029125SVivien Didelot	select CHECK_SIGNATURE
27647d029125SVivien Didelot	select NEW_LEDS
27657d029125SVivien Didelot	select LEDS_CLASS
2766a7f7f624SMasahiro Yamada	help
27677d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
27687d029125SVivien Didelot
2769e279b6c1SSam Ravnborgendif # X86_32
2770e279b6c1SSam Ravnborg
277123ac4ae8SAndreas Herrmannconfig AMD_NB
2772e279b6c1SSam Ravnborg	def_bool y
27730e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2774e279b6c1SSam Ravnborg
2775e3263ab3SDavid Herrmannconfig X86_SYSFB
2776e3263ab3SDavid Herrmann	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2777e3263ab3SDavid Herrmann	help
2778e3263ab3SDavid Herrmann	  Firmwares often provide initial graphics framebuffers so the BIOS,
2779e3263ab3SDavid Herrmann	  bootloader or kernel can show basic video-output during boot for
2780e3263ab3SDavid Herrmann	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2781e3263ab3SDavid Herrmann	  Extensions and EFI-framebuffers for this, which are mostly limited
2782e3263ab3SDavid Herrmann	  to x86.
2783e3263ab3SDavid Herrmann	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2784e3263ab3SDavid Herrmann	  framebuffers so the new generic system-framebuffer drivers can be
2785e3263ab3SDavid Herrmann	  used on x86. If the framebuffer is not compatible with the generic
2786e3a5dc08SNikolas Nyby	  modes, it is advertised as fallback platform framebuffer so legacy
2787e3263ab3SDavid Herrmann	  drivers like efifb, vesafb and uvesafb can pick it up.
2788e3263ab3SDavid Herrmann	  If this option is not selected, all system framebuffers are always
2789e3263ab3SDavid Herrmann	  marked as fallback platform framebuffers as usual.
2790e3263ab3SDavid Herrmann
2791e3263ab3SDavid Herrmann	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2792e3263ab3SDavid Herrmann	  not be able to pick up generic system framebuffers if this option
2793e3263ab3SDavid Herrmann	  is selected. You are highly encouraged to enable simplefb as
2794e3263ab3SDavid Herrmann	  replacement if you select this option. simplefb can correctly deal
2795e3263ab3SDavid Herrmann	  with generic system framebuffers. But you should still keep vesafb
2796e3263ab3SDavid Herrmann	  and others enabled as fallback if a system framebuffer is
2797e3263ab3SDavid Herrmann	  incompatible with simplefb.
2798e3263ab3SDavid Herrmann
2799e3263ab3SDavid Herrmann	  If unsure, say Y.
2800e3263ab3SDavid Herrmann
2801e279b6c1SSam Ravnborgendmenu
2802e279b6c1SSam Ravnborg
2803e279b6c1SSam Ravnborg
28041572497cSChristoph Hellwigmenu "Binary Emulations"
2805e279b6c1SSam Ravnborg
2806e279b6c1SSam Ravnborgconfig IA32_EMULATION
2807e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2808e279b6c1SSam Ravnborg	depends on X86_64
280939f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2810d1603990SRandy Dunlap	select BINFMT_ELF
281139f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2812a7f7f624SMasahiro Yamada	help
28135fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28145fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28155fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2816e279b6c1SSam Ravnborg
2817e279b6c1SSam Ravnborgconfig IA32_AOUT
2818e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28196b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2820eac61655SBorislav Petkov	depends on BROKEN
2821a7f7f624SMasahiro Yamada	help
2822e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2823e279b6c1SSam Ravnborg
28240bf62763SH. Peter Anvinconfig X86_X32
28256ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28269b54050bSBrian Gerst	depends on X86_64
2827a7f7f624SMasahiro Yamada	help
28285fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28295fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28305fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28315fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28325fd92e65SH. J. Lu
28335fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28345fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28355fd92e65SH. J. Lu	  option set.
28365fd92e65SH. J. Lu
2837953fee1dSIngo Molnarconfig COMPAT_32
2838953fee1dSIngo Molnar	def_bool y
2839953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2840953fee1dSIngo Molnar	select HAVE_UID16
2841953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2842953fee1dSIngo Molnar
2843e279b6c1SSam Ravnborgconfig COMPAT
28443c2362e6SHarvey Harrison	def_bool y
28450bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2846e279b6c1SSam Ravnborg
28473120e25eSJan Beulichif COMPAT
2848e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28493120e25eSJan Beulich	def_bool y
2850e279b6c1SSam Ravnborg
2851e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28523c2362e6SHarvey Harrison	def_bool y
28533120e25eSJan Beulich	depends on SYSVIPC
28543120e25eSJan Beulichendif
2855ee009e4aSDavid Howells
2856e279b6c1SSam Ravnborgendmenu
2857e279b6c1SSam Ravnborg
2858e279b6c1SSam Ravnborg
2859e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2860e5beae16SKeith Packard	def_bool y
2861e5beae16SKeith Packard	depends on X86_32
2862e5beae16SKeith Packard
2863e279b6c1SSam Ravnborgsource "drivers/firmware/Kconfig"
2864e279b6c1SSam Ravnborg
2865edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28665e8ebd84SJason A. Donenfeld
28675e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2868