xref: /linux/arch/x86/Kconfig (revision 59bd54a84d15e9335de5b8abe7b3b9713a36b99b)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
722792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
73fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
74399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7521266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
76b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
776471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7872d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
79316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
806974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
81957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
82bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
830c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8410bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
850ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
86c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8717596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
883010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
890aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
90ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
91d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
92d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
94ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
95ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9625c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
97c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
987e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9963703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1006471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1016471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10277fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1035e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1043599fe12SThomas Gleixner	select ARCH_STACKWALK
1052c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1066471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1075d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
108d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1096471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11014df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
111583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
112583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1136471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
114dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1156471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1166471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1172ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
118ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11981c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
120c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12151c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
12207431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1233876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12459612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12538d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
126b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12710916706SShile Zhang	select BUILDTIME_TABLE_SORT
1286471b825SIngo Molnar	select CLKEVT_I8253
1296471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1306471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1316471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1323aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13345471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13445471cd9SLinus Torvalds	select EDAC_SUPPORT
1356471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1366471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1376471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1386471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
13961dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1406471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14127d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1426471b825SIngo Molnar	select GENERIC_IOMAP
143c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1440fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
145ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1466471b825SIngo Molnar	select GENERIC_IRQ_PROBE
147c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1486471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1496471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1502ae27137SSteven Price	select GENERIC_PTDUMP
1516471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1526471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1537ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
154550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15539656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15617e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1577edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1586471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1596471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1606471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1616471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1626471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
163eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1646471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
165b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
166d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1670609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1681dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1696471b825SIngo Molnar	select HAVE_ARCH_KGDB
1709e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1719e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1721b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
173271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1746471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
175f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
176afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1776471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1786471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
179a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
180b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1817677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
182e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
183fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
184c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1852ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1866471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1876471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1886471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
189d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1906471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1916dafca97SSami Tolvanen	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
1924ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1936471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1949c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
195677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19606aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19702a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
198562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
199c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
200503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
20103f5781bSWang YanQing	select HAVE_EBPF_JIT
20258340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2036630a8e5SChristoph Hellwig	select HAVE_EISA
2045f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20567a929e0SChristoph Hellwig	select HAVE_FAST_GUP
206644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2076471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2084a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2096471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2106b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2110067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2126471b825SIngo Molnar	select HAVE_IOREMAP_PROT
213624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2146471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2156471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2166471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2176471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2186471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2196471b825SIngo Molnar	select HAVE_KERNEL_LZO
2206471b825SIngo Molnar	select HAVE_KERNEL_XZ
221fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2226471b825SIngo Molnar	select HAVE_KPROBES
2236471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
224540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2256471b825SIngo Molnar	select HAVE_KRETPROBES
226f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2276471b825SIngo Molnar	select HAVE_KVM
2286471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2290102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
230ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2319f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
232be37c98dSKalesh Singh	select HAVE_MOVE_PUD
23342a0bb3fSPetr Mladek	select HAVE_NMI
2346471b825SIngo Molnar	select HAVE_OPTPROBES
2356471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2366471b825SIngo Molnar	select HAVE_PERF_EVENTS
237c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23892e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
239eb01d42aSChristoph Hellwig	select HAVE_PCI
240c5e63197SJiri Olsa	select HAVE_PERF_REGS
241c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
242ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
24300998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2446471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2456415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2463c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2477ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
248cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
249d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
250c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
251e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2521e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
25399cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
254d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2556471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2566471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2577c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2587ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25905736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
260c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2617ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2627ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
26386596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2642eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
265625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2666471b825SIngo Molnar	select PERF_EVENTS
2673195ef59SPrarit Bhargava	select RTC_LIB
268d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2696471b825SIngo Molnar	select SPARSE_IRQ
27083fe27eaSPranith Kumar	select SRCU
2711e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2726471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
27315f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2744aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2756471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2766471b825SIngo Molnar	select VIRT_TO_BUS
2773b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2786471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2790c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
28050468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2819e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2827d8330a5SBalbir Singh
283ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2843120e25eSJan Beulich	def_bool y
2853120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
286ba7e4d13SIngo Molnar
28751b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
28851b26adaSLinus Torvalds	string
28951b26adaSLinus Torvalds	default "elf32-i386" if X86_32
29051b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
29151b26adaSLinus Torvalds
2928d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2933c2362e6SHarvey Harrison	def_bool y
2948d5fffb9SSam Ravnborg
2958d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2963c2362e6SHarvey Harrison	def_bool y
2978d5fffb9SSam Ravnborg
2988d5fffb9SSam Ravnborgconfig MMU
2993c2362e6SHarvey Harrison	def_bool y
3008d5fffb9SSam Ravnborg
3019e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3029e08f57dSDaniel Cashman	default 28 if 64BIT
3039e08f57dSDaniel Cashman	default 8
3049e08f57dSDaniel Cashman
3059e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3069e08f57dSDaniel Cashman	default 32 if 64BIT
3079e08f57dSDaniel Cashman	default 16
3089e08f57dSDaniel Cashman
3099e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3109e08f57dSDaniel Cashman	default 8
3119e08f57dSDaniel Cashman
3129e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3139e08f57dSDaniel Cashman	default 16
3149e08f57dSDaniel Cashman
3158d5fffb9SSam Ravnborgconfig SBUS
3168d5fffb9SSam Ravnborg	bool
3178d5fffb9SSam Ravnborg
3188d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3193120e25eSJan Beulich	def_bool y
3203120e25eSJan Beulich	depends on ISA_DMA_API
3218d5fffb9SSam Ravnborg
3228d5fffb9SSam Ravnborgconfig GENERIC_BUG
3233c2362e6SHarvey Harrison	def_bool y
3248d5fffb9SSam Ravnborg	depends on BUG
325b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
326b93a531eSJan Beulich
327b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
328b93a531eSJan Beulich	bool
3298d5fffb9SSam Ravnborg
3308d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3313120e25eSJan Beulich	def_bool y
3323120e25eSJan Beulich	depends on ISA_DMA_API
3338d5fffb9SSam Ravnborg
3341032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3351032c0baSSam Ravnborg	def_bool y
3361032c0baSSam Ravnborg
3379a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3389a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3398d5fffb9SSam Ravnborg
340801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
341801e4062SJohannes Berg	def_bool y
342801e4062SJohannes Berg
343d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
344d7109fe3SAndy Shevchenko	int
345d7109fe3SAndy Shevchenko	default 1024 if X86_64
346d7109fe3SAndy Shevchenko	default 512
347d7109fe3SAndy Shevchenko
348f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
349f4cb5700SJohannes Berg	def_bool y
350f4cb5700SJohannes Berg
3518d5fffb9SSam Ravnborgconfig AUDIT_ARCH
352e0fd24a3SJan Beulich	def_bool y if X86_64
3538d5fffb9SSam Ravnborg
354d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
355d6f2d75aSAndrey Ryabinin	hex
356d6f2d75aSAndrey Ryabinin	depends on KASAN
357d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
358d6f2d75aSAndrey Ryabinin
35969575d38SShane Wangconfig HAVE_INTEL_TXT
36069575d38SShane Wang	def_bool y
3616ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36269575d38SShane Wang
3636b0c3d44SSam Ravnborgconfig X86_32_SMP
3646b0c3d44SSam Ravnborg	def_bool y
3656b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3666b0c3d44SSam Ravnborg
3676b0c3d44SSam Ravnborgconfig X86_64_SMP
3686b0c3d44SSam Ravnborg	def_bool y
3696b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3706b0c3d44SSam Ravnborg
3712b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3722b144498SSrikar Dronamraju	def_bool y
3732b144498SSrikar Dronamraju
374d20642f0SRob Herringconfig FIX_EARLYCON_MEM
375d20642f0SRob Herring	def_bool y
376d20642f0SRob Herring
37794d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
37894d49eb3SKirill A. Shutemov	bool
37994d49eb3SKirill A. Shutemov
38098233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38198233368SKirill A. Shutemov	int
38277ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38398233368SKirill A. Shutemov	default 4 if X86_64
38498233368SKirill A. Shutemov	default 3 if X86_PAE
38598233368SKirill A. Shutemov	default 2
38698233368SKirill A. Shutemov
3872a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3882a61f474SMasahiro Yamada	bool
3892a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3902a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3912a61f474SMasahiro Yamada	help
3922a61f474SMasahiro Yamada	   We have to make sure stack protector is unconditionally disabled if
3933fb0fdb3SAndy Lutomirski	   the compiler produces broken code or if it does not let us control
3943fb0fdb3SAndy Lutomirski	   the segment on 32-bit kernels.
3952a61f474SMasahiro Yamada
396506f1d07SSam Ravnborgmenu "Processor type and features"
397506f1d07SSam Ravnborg
398506f1d07SSam Ravnborgconfig SMP
399506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
400a7f7f624SMasahiro Yamada	help
401506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4024a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4034a474157SRobert Graffham	  than one CPU, say Y.
404506f1d07SSam Ravnborg
4054a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
406506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
407506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4084a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
409506f1d07SSam Ravnborg	  will run faster if you say N here.
410506f1d07SSam Ravnborg
411506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
412506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
413506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
414506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
415506f1d07SSam Ravnborg
416506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
417506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
418506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
419506f1d07SSam Ravnborg
420cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4214f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
422506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
423506f1d07SSam Ravnborg
424506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
425506f1d07SSam Ravnborg
4269def39beSJosh Triplettconfig X86_FEATURE_NAMES
4279def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4289def39beSJosh Triplett	default y
429a7f7f624SMasahiro Yamada	help
4309def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4319def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4329def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4339def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4349def39beSJosh Triplett
4359def39beSJosh Triplett	  If in doubt, say Y.
4369def39beSJosh Triplett
43706cd9a7dSYinghai Luconfig X86_X2APIC
43806cd9a7dSYinghai Lu	bool "Support x2apic"
43919e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
440a7f7f624SMasahiro Yamada	help
44106cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44206cd9a7dSYinghai Lu
44306cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
44406cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
44506cd9a7dSYinghai Lu
44606cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
44706cd9a7dSYinghai Lu
4486695c85bSYinghai Luconfig X86_MPPARSE
4494590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4507a527688SJan Beulich	default y
4515ab74722SIngo Molnar	depends on X86_LOCAL_APIC
452a7f7f624SMasahiro Yamada	help
4536695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4546695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4556695c85bSYinghai Lu
456ddd70cf9SJun Nakajimaconfig GOLDFISH
457ddd70cf9SJun Nakajima	def_bool y
458ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
459ddd70cf9SJun Nakajima
46076b04384SDavid Woodhouseconfig RETPOLINE
46176b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46276b04384SDavid Woodhouse	default y
46376b04384SDavid Woodhouse	help
46476b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
46576b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
46676b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
46776b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
46876b04384SDavid Woodhouse
469e463a09aSPeter Zijlstraconfig CC_HAS_SLS
470e463a09aSPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
471e463a09aSPeter Zijlstra
472e463a09aSPeter Zijlstraconfig SLS
473e463a09aSPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
474e463a09aSPeter Zijlstra	depends on CC_HAS_SLS && X86_64
475e463a09aSPeter Zijlstra	default n
476e463a09aSPeter Zijlstra	help
477e463a09aSPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
478e463a09aSPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
479e463a09aSPeter Zijlstra	  larger.
480e463a09aSPeter Zijlstra
481e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
482e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4836fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48459fe5a77SThomas Gleixner	select KERNFS
485e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48678e99b4aSFenghua Yu	help
487e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4886fe07ce3SBabu Moger
4896fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4906fe07ce3SBabu Moger	  usage by the CPU.
4916fe07ce3SBabu Moger
4926fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4936fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4946fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4956fe07ce3SBabu Moger
4966fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4976fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4986fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
49978e99b4aSFenghua Yu
50078e99b4aSFenghua Yu	  Say N if unsure.
50178e99b4aSFenghua Yu
5028425091fSRavikiran G Thirumalaiif X86_32
503a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
504a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
505a0d0bb4dSRandy Dunlap	depends on SMP
506a7f7f624SMasahiro Yamada	help
507e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
508a0d0bb4dSRandy Dunlap
509c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
510c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
511c5c606d9SRavikiran G Thirumalai	default y
512a7f7f624SMasahiro Yamada	help
51306ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51406ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51506ac8346SIngo Molnar	  systems out there.)
51606ac8346SIngo Molnar
5178425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5188425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
519cb7b8023SBen Hutchings		Goldfish (Android emulator)
5208425091fSRavikiran G Thirumalai		AMD Elan
5218425091fSRavikiran G Thirumalai		RDC R-321x SoC
5228425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52383125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5243f4110a4SThomas Gleixner		Moorestown MID devices
52506ac8346SIngo Molnar
52606ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52706ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5288425091fSRavikiran G Thirumalaiendif
52906ac8346SIngo Molnar
5308425091fSRavikiran G Thirumalaiif X86_64
5318425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5328425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5338425091fSRavikiran G Thirumalai	default y
534a7f7f624SMasahiro Yamada	help
5358425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5368425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5378425091fSRavikiran G Thirumalai	  systems out there.)
5388425091fSRavikiran G Thirumalai
5398425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5408425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54144b111b5SSteffen Persvold		Numascale NumaChip
5428425091fSRavikiran G Thirumalai		ScaleMP vSMP
5438425091fSRavikiran G Thirumalai		SGI Ultraviolet
5448425091fSRavikiran G Thirumalai
5458425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5468425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5478425091fSRavikiran G Thirumalaiendif
548c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
549c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55044b111b5SSteffen Persvoldconfig X86_NUMACHIP
55144b111b5SSteffen Persvold	bool "Numascale NumaChip"
55244b111b5SSteffen Persvold	depends on X86_64
55344b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55444b111b5SSteffen Persvold	depends on NUMA
55544b111b5SSteffen Persvold	depends on SMP
55644b111b5SSteffen Persvold	depends on X86_X2APIC
557f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
558a7f7f624SMasahiro Yamada	help
55944b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56044b111b5SSteffen Persvold	  enable more than ~168 cores.
56144b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56203b48632SNick Piggin
5636a48565eSIngo Molnarconfig X86_VSMP
564c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5656276a074SBorislav Petkov	select HYPERVISOR_GUEST
5666a48565eSIngo Molnar	select PARAVIRT
5676a48565eSIngo Molnar	depends on X86_64 && PCI
568c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
569ead91d4bSShai Fultheim	depends on SMP
570a7f7f624SMasahiro Yamada	help
5716a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5726a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5736a48565eSIngo Molnar	  if you have one of these machines.
5746a48565eSIngo Molnar
575c5c606d9SRavikiran G Thirumalaiconfig X86_UV
576c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
577c5c606d9SRavikiran G Thirumalai	depends on X86_64
578c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
57954c28d29SJack Steiner	depends on NUMA
5801ecb4ae5SAndrew Morton	depends on EFI
581c2209ea5SIngo Molnar	depends on KEXEC_CORE
5829d6c26e7SSuresh Siddha	depends on X86_X2APIC
5831222e564SIngo Molnar	depends on PCI
584a7f7f624SMasahiro Yamada	help
585c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
586c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
587c5c606d9SRavikiran G Thirumalai
588c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
589c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
590506f1d07SSam Ravnborg
591ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
592ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
593cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
594a7f7f624SMasahiro Yamada	help
595ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
596ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
597ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
598ddd70cf9SJun Nakajima
599c751e17bSThomas Gleixnerconfig X86_INTEL_CE
600c751e17bSThomas Gleixner	bool "CE4100 TV platform"
601c751e17bSThomas Gleixner	depends on PCI
602c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6036084a6e2SJiang Liu	depends on X86_IO_APIC
604c751e17bSThomas Gleixner	depends on X86_32
605c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60637bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
607da6b737bSSebastian Andrzej Siewior	select OF
608da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
609a7f7f624SMasahiro Yamada	help
610c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
611c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
612c751e17bSThomas Gleixner	  boxes and media devices.
613c751e17bSThomas Gleixner
6144cb9b00fSDavid Cohenconfig X86_INTEL_MID
61543605ef1SAlan Cox	bool "Intel MID platform support"
61643605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
617edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6181ea7c673SAlan Cox	depends on PCI
6193fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6201ea7c673SAlan Cox	depends on X86_IO_APIC
6214cb9b00fSDavid Cohen	select I2C
6227c9c3a1eSAlan Cox	select DW_APB_TIMER
62354b34aa0SMika Westerberg	select INTEL_SCU_PCI
624a7f7f624SMasahiro Yamada	help
6254cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6264cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6274cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6281ea7c673SAlan Cox
6294cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6304cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63143605ef1SAlan Cox
6328bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6338bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6348bbc2a13SBryan O'Donoghue	depends on X86_32
6358bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6368bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6378bbc2a13SBryan O'Donoghue	depends on X86_TSC
6388bbc2a13SBryan O'Donoghue	depends on PCI
6398bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6408bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6418bbc2a13SBryan O'Donoghue	select IOSF_MBI
6428bbc2a13SBryan O'Donoghue	select INTEL_IMR
6439ab6eb51SAndy Shevchenko	select COMMON_CLK
644a7f7f624SMasahiro Yamada	help
6458bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6468bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6478bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6488bbc2a13SBryan O'Donoghue
6493d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6503d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6515962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6523d48aab1SMika Westerberg	select COMMON_CLK
6530f531431SMathias Nyman	select PINCTRL
654eebb3e8dSAndy Shevchenko	select IOSF_MBI
655a7f7f624SMasahiro Yamada	help
6563d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6573d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6580f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6590f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6603d48aab1SMika Westerberg
66192082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66292082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66392082a88SKen Xue	depends on ACPI
66492082a88SKen Xue	select COMMON_CLK
66592082a88SKen Xue	select PINCTRL
666a7f7f624SMasahiro Yamada	help
66792082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66892082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
66992082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67092082a88SKen Xue	  implemented under PINCTRL subsystem.
67192082a88SKen Xue
672ced3ce76SDavid E. Boxconfig IOSF_MBI
673ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
674ced3ce76SDavid E. Box	depends on PCI
675a7f7f624SMasahiro Yamada	help
676ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
677ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
678ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
679ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
680ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
681ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
682ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
683ced3ce76SDavid E. Box	   - BayTrail
684ced3ce76SDavid E. Box	   - Braswell
685ced3ce76SDavid E. Box	   - Quark
686ced3ce76SDavid E. Box
687ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
688ced3ce76SDavid E. Box
689ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
690ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
691ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
692a7f7f624SMasahiro Yamada	help
693ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
694ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
695ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
696ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
697ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
698ed2226bdSDavid E. Box	  device they want to access.
699ed2226bdSDavid E. Box
700ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
701ed2226bdSDavid E. Box
702c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
703c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
704506f1d07SSam Ravnborg	depends on X86_32
705c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
706c5c606d9SRavikiran G Thirumalai	select M486
707c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
708a7f7f624SMasahiro Yamada	help
709c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
710c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
711c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
712c5c606d9SRavikiran G Thirumalai
713e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7149c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7159c398017SIngo Molnar	depends on X86_32 && SMP
716c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
717a7f7f624SMasahiro Yamada	help
718b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
719b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
720b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
721b5660ba7SH. Peter Anvin	  one and will fallback to default.
722d49c4288SYinghai Lu
723c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
724d49c4288SYinghai Lu
725d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7266fc108a0SJan Beulich	def_bool y
727d949f36fSLinus Torvalds	# MCE code calls memory_failure():
728d949f36fSLinus Torvalds	depends on X86_MCE
729d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
730d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
731d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
732d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
733d949f36fSLinus Torvalds
73483125a3aSAlessandro Rubiniconfig STA2X11
73583125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73683125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73783125a3aSAlessandro Rubini	select SWIOTLB
73883125a3aSAlessandro Rubini	select MFD_STA2X11
7390145071bSLinus Walleij	select GPIOLIB
740a7f7f624SMasahiro Yamada	help
74183125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74283125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74383125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74483125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74583125a3aSAlessandro Rubini	  standard PC machines.
74683125a3aSAlessandro Rubini
74782148d1dSShérabconfig X86_32_IRIS
74882148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
74982148d1dSShérab	depends on X86_32
750a7f7f624SMasahiro Yamada	help
75182148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75282148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75382148d1dSShérab	  needed to do so, which is what this module does at
75482148d1dSShérab	  kernel shutdown.
75582148d1dSShérab
75682148d1dSShérab	  This is only for Iris machines from EuroBraille.
75782148d1dSShérab
75882148d1dSShérab	  If unused, say N.
75982148d1dSShérab
760ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7613c2362e6SHarvey Harrison	def_bool y
7623c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
763a87d0914SKen Chen	depends on X86
764a7f7f624SMasahiro Yamada	help
765506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
766506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
767506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
768506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
769506f1d07SSam Ravnborg
770506f1d07SSam Ravnborg	  If in doubt, say "Y".
771506f1d07SSam Ravnborg
7726276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7736276a074SBorislav Petkov	bool "Linux guest support"
774a7f7f624SMasahiro Yamada	help
7756276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7766276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7776276a074SBorislav Petkov	  setup.
778506f1d07SSam Ravnborg
7796276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7806276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
781506f1d07SSam Ravnborg
7826276a074SBorislav Petkovif HYPERVISOR_GUEST
783506f1d07SSam Ravnborg
784e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
785e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
786a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
787a7f7f624SMasahiro Yamada	help
788e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
789e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
790e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
791e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
792e61bd94aSEduardo Pereira Habkost
793c00a280aSJuergen Grossconfig PARAVIRT_XXL
794c00a280aSJuergen Gross	bool
795c00a280aSJuergen Gross
7966276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7976276a074SBorislav Petkov	bool "paravirt-ops debugging"
7986276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
799a7f7f624SMasahiro Yamada	help
8006276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8016276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8026276a074SBorislav Petkov
803b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
804b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8056ea30386SKees Cook	depends on PARAVIRT && SMP
806a7f7f624SMasahiro Yamada	help
807b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
808b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
809b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
810b4ecc126SJeremy Fitzhardinge
8114c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8124c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
813b4ecc126SJeremy Fitzhardinge
8144c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
815b4ecc126SJeremy Fitzhardinge
816ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
817ecca2502SZhao Yakui	def_bool n
818ecca2502SZhao Yakui
8196276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8206276a074SBorislav Petkov
8216276a074SBorislav Petkovconfig KVM_GUEST
8226276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8236276a074SBorislav Petkov	depends on PARAVIRT
8246276a074SBorislav Petkov	select PARAVIRT_CLOCK
825a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
826b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8276276a074SBorislav Petkov	default y
828a7f7f624SMasahiro Yamada	help
8296276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8306276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8316276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8326276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8336276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8346276a074SBorislav Petkov
835a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
836a1c4423bSMarcelo Tosatti	def_bool n
837a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
838a1c4423bSMarcelo Tosatti	help
839a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
840a1c4423bSMarcelo Tosatti
8417733607fSMaran Wilsonconfig PVH
8427733607fSMaran Wilson	bool "Support for running PVH guests"
843a7f7f624SMasahiro Yamada	help
8447733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8457733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8467733607fSMaran Wilson
8476276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8486276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8496276a074SBorislav Petkov	depends on PARAVIRT
850a7f7f624SMasahiro Yamada	help
8516276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8526276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8536276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8546276a074SBorislav Petkov	  that, there can be a small performance impact.
8556276a074SBorislav Petkov
8566276a074SBorislav Petkov	  If in doubt, say N here.
8576276a074SBorislav Petkov
8587af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8597af192c9SGerd Hoffmann	bool
8607af192c9SGerd Hoffmann
8614a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8624a362601SJan Kiszka	bool "Jailhouse non-root cell support"
863abde587bSArnd Bergmann	depends on X86_64 && PCI
86487e65d05SJan Kiszka	select X86_PM_TIMER
865a7f7f624SMasahiro Yamada	help
8664a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8674a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8684a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8694a362601SJan Kiszka
870ec7972c9SZhao Yakuiconfig ACRN_GUEST
871ec7972c9SZhao Yakui	bool "ACRN Guest support"
872ec7972c9SZhao Yakui	depends on X86_64
873498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
874ec7972c9SZhao Yakui	help
875ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
876ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
877ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
878ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
879ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
880ec7972c9SZhao Yakui
881*59bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
882*59bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
883*59bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
884*59bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
885*59bd54a8SKuppuswamy Sathyanarayanan	help
886*59bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
887*59bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
888*59bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
889*59bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
890*59bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
891*59bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
892*59bd54a8SKuppuswamy Sathyanarayanan
8936276a074SBorislav Petkovendif #HYPERVISOR_GUEST
89497349135SJeremy Fitzhardinge
895506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
896506f1d07SSam Ravnborg
897506f1d07SSam Ravnborgconfig HPET_TIMER
8983c2362e6SHarvey Harrison	def_bool X86_64
899506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
900a7f7f624SMasahiro Yamada	help
901506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
902506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
903506f1d07SSam Ravnborg	  present.
904506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
905506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
906506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9074e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9084e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
909506f1d07SSam Ravnborg
910506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
911506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
912506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
913506f1d07SSam Ravnborg
914506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
915506f1d07SSam Ravnborg
916506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9173c2362e6SHarvey Harrison	def_bool y
9183228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
919506f1d07SSam Ravnborg
9206a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
921506f1d07SSam Ravnborg# The code disables itself when not needed.
9227ae9392cSThomas Petazzoniconfig DMI
9237ae9392cSThomas Petazzoni	default y
924cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9256a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
926a7f7f624SMasahiro Yamada	help
9277ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9287ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9297ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9307ae9392cSThomas Petazzoni	  BIOS code.
9317ae9392cSThomas Petazzoni
932506f1d07SSam Ravnborgconfig GART_IOMMU
93338901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9342f9237d4SChristoph Hellwig	select DMA_OPS
935a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
936506f1d07SSam Ravnborg	select SWIOTLB
93723ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
938a7f7f624SMasahiro Yamada	help
939ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
940ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
941ced3c42cSIngo Molnar
942ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
943ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
944ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
945ced3c42cSIngo Molnar
946ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
947ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
948ced3c42cSIngo Molnar
949ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
950ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
951ced3c42cSIngo Molnar	  32-bit limited device.
952ced3c42cSIngo Molnar
953ced3c42cSIngo Molnar	  If unsure, say Y.
954506f1d07SSam Ravnborg
9551184dc2fSMike Travisconfig MAXSMP
956ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9576ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95836f5101aSMike Travis	select CPUMASK_OFFSTACK
959a7f7f624SMasahiro Yamada	help
960ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9611184dc2fSMike Travis	  If unsure, say N.
962506f1d07SSam Ravnborg
963aec6487eSIngo Molnar#
964aec6487eSIngo Molnar# The maximum number of CPUs supported:
965aec6487eSIngo Molnar#
966aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
967aec6487eSIngo Molnar# and which can be configured interactively in the
968aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
969aec6487eSIngo Molnar#
970aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
971aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
972aec6487eSIngo Molnar#
973aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
974aec6487eSIngo Molnar#   interactive configuration. )
975aec6487eSIngo Molnar#
976a0d0bb4dSRandy Dunlap
977aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
978a0d0bb4dSRandy Dunlap	int
979aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
980a0d0bb4dSRandy Dunlap	default    1 if !SMP
981a0d0bb4dSRandy Dunlap	default    2
982a0d0bb4dSRandy Dunlap
983aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
984a0d0bb4dSRandy Dunlap	int
985a0d0bb4dSRandy Dunlap	depends on X86_32
986aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
987aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
988a0d0bb4dSRandy Dunlap	default    1 if !SMP
989a0d0bb4dSRandy Dunlap
990aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
991a0d0bb4dSRandy Dunlap	int
992a0d0bb4dSRandy Dunlap	depends on X86_64
9931edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9941edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
995a0d0bb4dSRandy Dunlap	default    1 if !SMP
996aec6487eSIngo Molnar
997aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
998aec6487eSIngo Molnar	int
999aec6487eSIngo Molnar	depends on X86_32
1000aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1001aec6487eSIngo Molnar	default    8 if  SMP
1002aec6487eSIngo Molnar	default    1 if !SMP
1003aec6487eSIngo Molnar
1004aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1005aec6487eSIngo Molnar	int
1006aec6487eSIngo Molnar	depends on X86_64
1007a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1008a0d0bb4dSRandy Dunlap	default   64 if  SMP
1009aec6487eSIngo Molnar	default    1 if !SMP
1010a0d0bb4dSRandy Dunlap
1011506f1d07SSam Ravnborgconfig NR_CPUS
101236f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1013aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1014aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1015a7f7f624SMasahiro Yamada	help
1016506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1017bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1018cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1019506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1020506f1d07SSam Ravnborg
1021aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1022aec6487eSIngo Molnar	  to the kernel image.
1023506f1d07SSam Ravnborg
102466558b73STim Chenconfig SCHED_CLUSTER
102566558b73STim Chen	bool "Cluster scheduler support"
102666558b73STim Chen	depends on SMP
102766558b73STim Chen	default y
102866558b73STim Chen	help
102966558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
103066558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
103166558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
103266558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
103366558b73STim Chen	  busses.
103466558b73STim Chen
1035506f1d07SSam Ravnborgconfig SCHED_SMT
1036dbe73364SThomas Gleixner	def_bool y if SMP
1037506f1d07SSam Ravnborg
1038506f1d07SSam Ravnborgconfig SCHED_MC
10393c2362e6SHarvey Harrison	def_bool y
10403c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1041c8e56d20SBorislav Petkov	depends on SMP
1042a7f7f624SMasahiro Yamada	help
1043506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1044506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1045506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1046506f1d07SSam Ravnborg
1047de966cf4STim Chenconfig SCHED_MC_PRIO
1048de966cf4STim Chen	bool "CPU core priorities scheduler support"
10490a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10500a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10510a21fc12SIngo Molnar	select CPU_FREQ
1052de966cf4STim Chen	default y
1053a7f7f624SMasahiro Yamada	help
1054de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1055de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1056de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1057de966cf4STim Chen	  single threaded workloads) than others.
1058de966cf4STim Chen
1059de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1060de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1061de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1062de966cf4STim Chen	  overall system performance can be achieved.
1063de966cf4STim Chen
1064de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1065de966cf4STim Chen
1066de966cf4STim Chen	  If unsure say Y here.
10675e76b2abSTim Chen
106830b8b006SThomas Gleixnerconfig UP_LATE_INIT
106930b8b006SThomas Gleixner	def_bool y
1070ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
107130b8b006SThomas Gleixner
1072506f1d07SSam Ravnborgconfig X86_UP_APIC
107350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
107450849eefSJan Beulich	default PCI_MSI
107538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1076a7f7f624SMasahiro Yamada	help
1077506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1078506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1079506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1080506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1081506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1082506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1083506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1084506f1d07SSam Ravnborg	  lockups.
1085506f1d07SSam Ravnborg
1086506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1087506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1088506f1d07SSam Ravnborg	depends on X86_UP_APIC
1089a7f7f624SMasahiro Yamada	help
1090506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1091506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1092506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1093506f1d07SSam Ravnborg
1094506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1095506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1096506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1097506f1d07SSam Ravnborg
1098506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10993c2362e6SHarvey Harrison	def_bool y
11000dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1101b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
110252f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1103506f1d07SSam Ravnborg
1104506f1d07SSam Ravnborgconfig X86_IO_APIC
1105b1da1e71SJan Beulich	def_bool y
1106b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1107506f1d07SSam Ravnborg
110841b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
110941b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
111041b9eb26SStefan Assmann	depends on X86_IO_APIC
1111a7f7f624SMasahiro Yamada	help
111241b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
111341b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
111441b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
111541b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
111641b9eb26SStefan Assmann
111741b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
111841b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
111941b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
112041b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
112141b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
112241b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
112341b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
112441b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
112541b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
112641b9eb26SStefan Assmann	  down (vital) interrupt lines.
112741b9eb26SStefan Assmann
112841b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
112941b9eb26SStefan Assmann	  increased on these systems.
113041b9eb26SStefan Assmann
1131506f1d07SSam Ravnborgconfig X86_MCE
1132bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1133648ed940SChen, Gong	select GENERIC_ALLOCATOR
1134e57dbaf7SBorislav Petkov	default y
1135a7f7f624SMasahiro Yamada	help
1136bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1137bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1138506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1139bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11404efc0670SAndi Kleen
11415de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11425de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11435de97c9fSTony Luck	depends on X86_MCE
1144a7f7f624SMasahiro Yamada	help
11455de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11465de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11475de97c9fSTony Luck	  rasdaemon solution.
11485de97c9fSTony Luck
1149506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11503c2362e6SHarvey Harrison	def_bool y
11513c2362e6SHarvey Harrison	prompt "Intel MCE features"
1152c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1153a7f7f624SMasahiro Yamada	help
1154506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1155506f1d07SSam Ravnborg	   the thermal monitor.
1156506f1d07SSam Ravnborg
1157506f1d07SSam Ravnborgconfig X86_MCE_AMD
11583c2362e6SHarvey Harrison	def_bool y
11593c2362e6SHarvey Harrison	prompt "AMD MCE features"
1160f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1161a7f7f624SMasahiro Yamada	help
1162506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1163506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1164506f1d07SSam Ravnborg
11654efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11666fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1167c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1168a7f7f624SMasahiro Yamada	help
11694efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11705065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11714efc0670SAndi Kleen	  line.
11724efc0670SAndi Kleen
1173b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1174b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11756fc108a0SJan Beulich	def_bool y
1176b2762686SAndi Kleen
1177ea149b36SAndi Kleenconfig X86_MCE_INJECT
1178bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1179ea149b36SAndi Kleen	tristate "Machine check injector support"
1180a7f7f624SMasahiro Yamada	help
1181ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1182ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1183ea149b36SAndi Kleen	  QA it is safe to say n.
1184ea149b36SAndi Kleen
118507dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1186e633c65aSKan Liang
11875aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11881e642812SIngo Molnar	bool "Legacy VM86 support"
1189506f1d07SSam Ravnborg	depends on X86_32
1190a7f7f624SMasahiro Yamada	help
11915aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11925aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11935aef51c3SAndy Lutomirski
11945aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11955aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11965aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11975aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11985aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11991e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12001e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12011e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12021e642812SIngo Molnar	  enable this option.
12035aef51c3SAndy Lutomirski
12041e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12051e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12061e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12071e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12085aef51c3SAndy Lutomirski
12091e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12101e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12115aef51c3SAndy Lutomirski
12121e642812SIngo Molnar	  If unsure, say N here.
12135aef51c3SAndy Lutomirski
12145aef51c3SAndy Lutomirskiconfig VM86
12155aef51c3SAndy Lutomirski	bool
12165aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
121734273f41SH. Peter Anvin
121834273f41SH. Peter Anvinconfig X86_16BIT
121934273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
122034273f41SH. Peter Anvin	default y
1221a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1222a7f7f624SMasahiro Yamada	help
122334273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
122434273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
122534273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
122634273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122734273f41SH. Peter Anvin
122834273f41SH. Peter Anvinconfig X86_ESPFIX32
122934273f41SH. Peter Anvin	def_bool y
123034273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1231506f1d07SSam Ravnborg
1232197725deSH. Peter Anvinconfig X86_ESPFIX64
1233197725deSH. Peter Anvin	def_bool y
123434273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1235506f1d07SSam Ravnborg
12361ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12371ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12381ad83c85SAndy Lutomirski	default y
12391ad83c85SAndy Lutomirski	depends on X86_64
1240a7f7f624SMasahiro Yamada	help
12411ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12421ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12431ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12441ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12451ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12461ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12471ad83c85SAndy Lutomirski
12481ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12491ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12501ad83c85SAndy Lutomirski
12511ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12521ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12531ad83c85SAndy Lutomirski
1254111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1255111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1256a24ca997SThomas Gleixner	default y
1257a7f7f624SMasahiro Yamada	help
1258111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1259111e7b15SThomas Gleixner	  for legacy applications.
1260111e7b15SThomas Gleixner
1261c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1262c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1263c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1264c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1265c8137aceSThomas Gleixner	  modules.
1266c8137aceSThomas Gleixner
1267c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1268c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1269a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1270a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1271c8137aceSThomas Gleixner
1272506f1d07SSam Ravnborgconfig TOSHIBA
1273506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1274506f1d07SSam Ravnborg	depends on X86_32
1275a7f7f624SMasahiro Yamada	help
1276506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1277506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1278506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1279506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1280506f1d07SSam Ravnborg
1281506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1282506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1283506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1284506f1d07SSam Ravnborg
1285506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1286506f1d07SSam Ravnborg	  Say N otherwise.
1287506f1d07SSam Ravnborg
1288506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12899ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12909ba16087SJan Beulich	depends on X86_32
1291a7f7f624SMasahiro Yamada	help
1292506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1293506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1294506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1295506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1296506f1d07SSam Ravnborg	  system.
1297506f1d07SSam Ravnborg
1298506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
12995e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1300506f1d07SSam Ravnborg
1301506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1302506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1303506f1d07SSam Ravnborg	  Say N otherwise.
1304506f1d07SSam Ravnborg
1305506f1d07SSam Ravnborgconfig MICROCODE
13069a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13079a2bc335SBorislav Petkov	default y
130880030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1309a7f7f624SMasahiro Yamada	help
1310506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13115f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13125f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13135f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13145f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13155f9c01aaSBorislav Petkov	  the Linux kernel.
1316506f1d07SSam Ravnborg
13175f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1318cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13195f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13205f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1321506f1d07SSam Ravnborg
1322c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1323c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1324c508c46eSBenjamin Gilbert	  config option.
1325506f1d07SSam Ravnborg
13268d86f390SPeter Orubaconfig MICROCODE_INTEL
1327e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13288d86f390SPeter Oruba	depends on MICROCODE
13298d86f390SPeter Oruba	default MICROCODE
1330a7f7f624SMasahiro Yamada	help
13318d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13328d86f390SPeter Oruba	  processors.
13338d86f390SPeter Oruba
1334b8989db9SAlan	  For the current Intel microcode data package go to
1335b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1336b8989db9SAlan	  'Linux Processor Microcode Data File'.
13378d86f390SPeter Oruba
133880cc9f10SPeter Orubaconfig MICROCODE_AMD
1339e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
134080cc9f10SPeter Oruba	depends on MICROCODE
1341a7f7f624SMasahiro Yamada	help
134280cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
134380cc9f10SPeter Oruba	  processors will be enabled.
134480cc9f10SPeter Oruba
1345506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1346c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1347c02f48e0SBorislav Petkov	default n
1348506f1d07SSam Ravnborg	depends on MICROCODE
1349a7f7f624SMasahiro Yamada	help
1350c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1351c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1352c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1353c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1354c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1355cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1356506f1d07SSam Ravnborg
1357506f1d07SSam Ravnborgconfig X86_MSR
1358506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1359a7f7f624SMasahiro Yamada	help
1360506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1361506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1362506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1363506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1364506f1d07SSam Ravnborg	  systems.
1365506f1d07SSam Ravnborg
1366506f1d07SSam Ravnborgconfig X86_CPUID
1367506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1368a7f7f624SMasahiro Yamada	help
1369506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1370506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1371506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1372506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgchoice
1375506f1d07SSam Ravnborg	prompt "High Memory Support"
13766fc108a0SJan Beulich	default HIGHMEM4G
1377506f1d07SSam Ravnborg	depends on X86_32
1378506f1d07SSam Ravnborg
1379506f1d07SSam Ravnborgconfig NOHIGHMEM
1380506f1d07SSam Ravnborg	bool "off"
1381a7f7f624SMasahiro Yamada	help
1382506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1383506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1384506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1385506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1386506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1387506f1d07SSam Ravnborg	  "high memory".
1388506f1d07SSam Ravnborg
1389506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1390506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1391506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1392506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1393506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1394506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1395506f1d07SSam Ravnborg	  possible.
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1398506f1d07SSam Ravnborg	  answer "4GB" here.
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1401506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1402506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1403506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1404506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1405506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1406506f1d07SSam Ravnborg
1407506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1408506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1409506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1410506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1411506f1d07SSam Ravnborg	  kernel at boot time.)
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If unsure, say "off".
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborgconfig HIGHMEM4G
1416506f1d07SSam Ravnborg	bool "4GB"
1417a7f7f624SMasahiro Yamada	help
1418506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1419506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborgconfig HIGHMEM64G
1422506f1d07SSam Ravnborg	bool "64GB"
1423225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1424506f1d07SSam Ravnborg	select X86_PAE
1425a7f7f624SMasahiro Yamada	help
1426506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1427506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgendchoice
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborgchoice
14326a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1433506f1d07SSam Ravnborg	default VMSPLIT_3G
1434506f1d07SSam Ravnborg	depends on X86_32
1435a7f7f624SMasahiro Yamada	help
1436506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1437506f1d07SSam Ravnborg
1438506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1439506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1440506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1441506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1442506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1443506f1d07SSam Ravnborg	  available to user programs, making the address space there
1444506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1445506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1446506f1d07SSam Ravnborg	  kernel modules.
1447506f1d07SSam Ravnborg
1448506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1449506f1d07SSam Ravnborg	  option alone!
1450506f1d07SSam Ravnborg
1451506f1d07SSam Ravnborg	config VMSPLIT_3G
1452506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1453506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1454506f1d07SSam Ravnborg		depends on !X86_PAE
1455506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1456506f1d07SSam Ravnborg	config VMSPLIT_2G
1457506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1458506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1459506f1d07SSam Ravnborg		depends on !X86_PAE
1460506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1461506f1d07SSam Ravnborg	config VMSPLIT_1G
1462506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1463506f1d07SSam Ravnborgendchoice
1464506f1d07SSam Ravnborg
1465506f1d07SSam Ravnborgconfig PAGE_OFFSET
1466506f1d07SSam Ravnborg	hex
1467506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1468506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1469506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1470506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1471506f1d07SSam Ravnborg	default 0xC0000000
1472506f1d07SSam Ravnborg	depends on X86_32
1473506f1d07SSam Ravnborg
1474506f1d07SSam Ravnborgconfig HIGHMEM
14753c2362e6SHarvey Harrison	def_bool y
1476506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1477506f1d07SSam Ravnborg
1478506f1d07SSam Ravnborgconfig X86_PAE
14799ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1480506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1481d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14829d99c712SChristian Melki	select SWIOTLB
1483a7f7f624SMasahiro Yamada	help
1484506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1485506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1486506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1487506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1488506f1d07SSam Ravnborg
148977ef56e4SKirill A. Shutemovconfig X86_5LEVEL
149077ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
149118ec1eafSKirill A. Shutemov	default y
1492eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1493162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
149477ef56e4SKirill A. Shutemov	depends on X86_64
1495a7f7f624SMasahiro Yamada	help
149677ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
149777ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
149877ef56e4SKirill A. Shutemov	  physical address space.
149977ef56e4SKirill A. Shutemov
150077ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
150177ef56e4SKirill A. Shutemov
15026657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15036657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
150477ef56e4SKirill A. Shutemov
1505cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
150677ef56e4SKirill A. Shutemov	  information.
150777ef56e4SKirill A. Shutemov
150877ef56e4SKirill A. Shutemov	  Say N if unsure.
150977ef56e4SKirill A. Shutemov
151010971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1511e5008abeSLuis R. Rodriguez	def_bool y
15122e1da13fSVlastimil Babka	depends on X86_64
1513a7f7f624SMasahiro Yamada	help
151410971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
151510971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
151610971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
151710971ab2SIngo Molnar	  that we have them enabled.
15189e899816SNick Piggin
15195c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15205c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15215c280cf6SThomas Gleixner	depends on DEBUG_FS
1522a7f7f624SMasahiro Yamada	help
1523b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1524a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15255c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15265c280cf6SThomas Gleixner
152720f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
152820f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
152920f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
153020f07a04SKirill A. Shutemov	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
153120f07a04SKirill A. Shutemov	def_bool n
153220f07a04SKirill A. Shutemov
15337744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15347744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15357744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
153682fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1537ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1538597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1539aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
154020f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1541a7f7f624SMasahiro Yamada	help
15427744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15437744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15447744ccdbSTom Lendacky	  Encryption (SME).
15457744ccdbSTom Lendacky
15467744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15477744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15487744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1549a7f7f624SMasahiro Yamada	help
15507744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15517744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15527744ccdbSTom Lendacky
15537744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15547744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15557744ccdbSTom Lendacky
15567744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15577744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15587744ccdbSTom Lendacky
1559506f1d07SSam Ravnborg# Common NUMA Features
1560506f1d07SSam Ravnborgconfig NUMA
1561e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1562506f1d07SSam Ravnborg	depends on SMP
1563b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1564b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15657ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1566a7f7f624SMasahiro Yamada	help
1567e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1568fd51b2d7SKOSAKI Motohiro
1569506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1570506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1571506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1572506f1d07SSam Ravnborg
1573c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1574fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1575fd51b2d7SKOSAKI Motohiro
1576b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15777cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1578fd51b2d7SKOSAKI Motohiro
1579fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1580506f1d07SSam Ravnborg
1581eec1d4faSHans Rosenfeldconfig AMD_NUMA
15823c2362e6SHarvey Harrison	def_bool y
15833c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15845da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1585a7f7f624SMasahiro Yamada	help
1586eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1587eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1588eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1589eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1590eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1591506f1d07SSam Ravnborg
1592506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15933c2362e6SHarvey Harrison	def_bool y
15943c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1595506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1596506f1d07SSam Ravnborg	select ACPI_NUMA
1597a7f7f624SMasahiro Yamada	help
1598506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1599506f1d07SSam Ravnborg
1600506f1d07SSam Ravnborgconfig NUMA_EMU
1601506f1d07SSam Ravnborg	bool "NUMA emulation"
16021b7e03efSTejun Heo	depends on NUMA
1603a7f7f624SMasahiro Yamada	help
1604506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1605506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1606506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1607506f1d07SSam Ravnborg
1608506f1d07SSam Ravnborgconfig NODES_SHIFT
1609d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
161051591e31SDavid Rientjes	range 1 10
161151591e31SDavid Rientjes	default "10" if MAXSMP
1612506f1d07SSam Ravnborg	default "6" if X86_64
1613506f1d07SSam Ravnborg	default "3"
1614a9ee6cf5SMike Rapoport	depends on NUMA
1615a7f7f624SMasahiro Yamada	help
16161184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1617692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1618506f1d07SSam Ravnborg
1619506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1620506f1d07SSam Ravnborg	def_bool y
16213b16651fSTejun Heo	depends on X86_32 && !NUMA
1622506f1d07SSam Ravnborg
1623506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1624506f1d07SSam Ravnborg	def_bool y
16256ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1626506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1627506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1628506f1d07SSam Ravnborg
16293b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16306ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16313b16651fSTejun Heo
1632506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1633506f1d07SSam Ravnborg	def_bool y
16344eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1635506f1d07SSam Ravnborg
1636506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1637a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16385c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1639a0842b70SToshi Kani	help
1640a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1641cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1642a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1643506f1d07SSam Ravnborg
16443b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16453b16651fSTejun Heo	def_bool y
16463b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16473b16651fSTejun Heo
1648a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1649a29815a3SAvi Kivity	hex
1650a29815a3SAvi Kivity	default 0 if X86_32
1651a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1652a29815a3SAvi Kivity
16537a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16547a67832cSDan Williams	bool
16557a67832cSDan Williams
1656ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16577a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16589f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16599f53f9faSDan Williams	depends on BLK_DEV
16607a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16617b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16629f53f9faSDan Williams	select LIBNVDIMM
1663ec776ef6SChristoph Hellwig	help
1664ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1665ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1666ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1667ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1668ec776ef6SChristoph Hellwig
1669ec776ef6SChristoph Hellwig	  Say Y if unsure.
1670ec776ef6SChristoph Hellwig
1671506f1d07SSam Ravnborgconfig HIGHPTE
1672506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16736fc108a0SJan Beulich	depends on HIGHMEM
1674a7f7f624SMasahiro Yamada	help
1675506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1676506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1677506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1678506f1d07SSam Ravnborg	  entries in high memory.
1679506f1d07SSam Ravnborg
16809f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16819f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1682a7f7f624SMasahiro Yamada	help
16839f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16849f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16859f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16869f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16879f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16889f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16899f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16908c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16919f077871SJeremy Fitzhardinge
16929f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16939f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
16949f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
16959f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
16969f077871SJeremy Fitzhardinge
16979f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
16989f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
16999f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17009f077871SJeremy Fitzhardinge	  memory.
17019f077871SJeremy Fitzhardinge
1702c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1703c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1704c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1705c885df50SJeremy Fitzhardinge	default y
1706a7f7f624SMasahiro Yamada	help
1707c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1708c885df50SJeremy Fitzhardinge	  on or off.
1709c885df50SJeremy Fitzhardinge
1710506f1d07SSam Ravnborgconfig MATH_EMULATION
1711506f1d07SSam Ravnborg	bool
1712a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
171387d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1714a7f7f624SMasahiro Yamada	help
1715506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1716506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1717506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1718506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1719506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1720506f1d07SSam Ravnborg	  coprocessor or this emulation.
1721506f1d07SSam Ravnborg
1722506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1723506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1724506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1725506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1726506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1727506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1728506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1729506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1730506f1d07SSam Ravnborg
1731506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1732506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1733506f1d07SSam Ravnborg
1734506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1735506f1d07SSam Ravnborg	  kernel, it won't hurt.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborgconfig MTRR
17386fc108a0SJan Beulich	def_bool y
17396a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1740a7f7f624SMasahiro Yamada	help
1741506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1742506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1743506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1744506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1745506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1746506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1747506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1748506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1749506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1750506f1d07SSam Ravnborg
1751506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1752506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1753506f1d07SSam Ravnborg	  as well:
1754506f1d07SSam Ravnborg
1755506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1756506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1757506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1758506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1759506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1760506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1761506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1762506f1d07SSam Ravnborg
1763506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1764506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1765506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1766506f1d07SSam Ravnborg
1767506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1768506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1769506f1d07SSam Ravnborg
1770cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1771506f1d07SSam Ravnborg
177295ffa243SYinghai Luconfig MTRR_SANITIZER
17732ffb3501SYinghai Lu	def_bool y
177495ffa243SYinghai Lu	prompt "MTRR cleanup support"
177595ffa243SYinghai Lu	depends on MTRR
1776a7f7f624SMasahiro Yamada	help
1777aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1778aba3728cSThomas Gleixner	  add writeback entries.
177995ffa243SYinghai Lu
1780aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1781692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1782aba3728cSThomas Gleixner	  mtrr_chunk_size.
178395ffa243SYinghai Lu
17842ffb3501SYinghai Lu	  If unsure, say Y.
178595ffa243SYinghai Lu
178695ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1787f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1788f5098d62SYinghai Lu	range 0 1
1789f5098d62SYinghai Lu	default "0"
179095ffa243SYinghai Lu	depends on MTRR_SANITIZER
1791a7f7f624SMasahiro Yamada	help
1792f5098d62SYinghai Lu	  Enable mtrr cleanup default value
179395ffa243SYinghai Lu
179412031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
179512031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
179612031a62SYinghai Lu	range 0 7
179712031a62SYinghai Lu	default "1"
179812031a62SYinghai Lu	depends on MTRR_SANITIZER
1799a7f7f624SMasahiro Yamada	help
180012031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1801aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180212031a62SYinghai Lu
18032e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18046fc108a0SJan Beulich	def_bool y
18056a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18062a8a2719SIngo Molnar	depends on MTRR
1807a7f7f624SMasahiro Yamada	help
18082e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1809042b78e4SVenki Pallipadi
18102e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18112e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18122e5d9c85Svenkatesh.pallipadi@intel.com
18132e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1814042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18152e5d9c85Svenkatesh.pallipadi@intel.com
18162e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18172e5d9c85Svenkatesh.pallipadi@intel.com
181846cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
181946cf98cdSVenkatesh Pallipadi	def_bool y
182046cf98cdSVenkatesh Pallipadi	depends on X86_PAT
182146cf98cdSVenkatesh Pallipadi
1822628c6246SH. Peter Anvinconfig ARCH_RANDOM
1823628c6246SH. Peter Anvin	def_bool y
1824628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1825a7f7f624SMasahiro Yamada	help
1826628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1827628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1828628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1829628c6246SH. Peter Anvin	  secure hardware random number generator.
1830628c6246SH. Peter Anvin
183151ae4a2dSH. Peter Anvinconfig X86_SMAP
183251ae4a2dSH. Peter Anvin	def_bool y
183351ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1834a7f7f624SMasahiro Yamada	help
183551ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
183651ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
183751ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
183851ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
183951ae4a2dSH. Peter Anvin
184051ae4a2dSH. Peter Anvin	  If unsure, say Y.
184151ae4a2dSH. Peter Anvin
1842b971880fSBabu Mogerconfig X86_UMIP
1843796ebc81SRicardo Neri	def_bool y
1844b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1845a7f7f624SMasahiro Yamada	help
1846b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1847b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1848b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1849b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1850b971880fSBabu Moger	  information about the hardware state.
1851796ebc81SRicardo Neri
1852796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1853796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1854796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1855796ebc81SRicardo Neri	  results are dummy.
1856aa35f896SRicardo Neri
1857156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1858156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1859156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1860156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1861262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1862262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1863156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1864262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1865156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1866156ff4a5SPeter Zijlstra
1867156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1868156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
1869156ff4a5SPeter Zijlstra	bool
1870ed53a0d9SPeter Zijlstra	depends on X86_64 && CC_HAS_IBT && STACK_VALIDATION
1871f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1872f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1873156ff4a5SPeter Zijlstra	help
1874156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1875156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1876156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1877156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1878156ff4a5SPeter Zijlstra	  code with them to make this happen.
1879156ff4a5SPeter Zijlstra
1880ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
1881ed53a0d9SPeter Zijlstra	  are not indirect call targets, avoiding them ever becomming one.
1882ed53a0d9SPeter Zijlstra
1883ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1884ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1885ed53a0d9SPeter Zijlstra	  kernel image.
1886ed53a0d9SPeter Zijlstra
188735e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
188838f3e775SBabu Moger	prompt "Memory Protection Keys"
188935e97790SDave Hansen	def_bool y
1890284244a9SDave Hansen	# Note: only available in 64-bit mode
189138f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
189252c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
189352c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1894a7f7f624SMasahiro Yamada	help
1895284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1896284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1897284244a9SDave Hansen	  page tables when an application changes protection domains.
1898284244a9SDave Hansen
18991eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1900284244a9SDave Hansen
1901284244a9SDave Hansen	  If unsure, say y.
190235e97790SDave Hansen
1903db616173SMichal Hockochoice
1904db616173SMichal Hocko	prompt "TSX enable mode"
1905db616173SMichal Hocko	depends on CPU_SUP_INTEL
1906db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1907db616173SMichal Hocko	help
1908db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1909db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1910db616173SMichal Hocko	  can lead to a noticeable performance boost.
1911db616173SMichal Hocko
1912db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1913db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1914db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1915db616173SMichal Hocko
1916db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1917db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1918db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1919db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1920db616173SMichal Hocko	  for the particular machine.
1921db616173SMichal Hocko
1922db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1923db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1924db616173SMichal Hocko	  details.
1925db616173SMichal Hocko
1926db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1927db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1928db616173SMichal Hocko	  relevant.
1929db616173SMichal Hocko
1930db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1931db616173SMichal Hocko	bool "off"
1932db616173SMichal Hocko	help
1933db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1934db616173SMichal Hocko
1935db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1936db616173SMichal Hocko	bool "on"
1937db616173SMichal Hocko	help
1938db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1939db616173SMichal Hocko	  line parameter.
1940db616173SMichal Hocko
1941db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1942db616173SMichal Hocko	bool "auto"
1943db616173SMichal Hocko	help
1944db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1945db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1946db616173SMichal Hockoendchoice
1947db616173SMichal Hocko
1948e7e05452SSean Christophersonconfig X86_SGX
1949e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1950e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1951e7e05452SSean Christopherson	depends on CRYPTO=y
1952e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1953e7e05452SSean Christopherson	select SRCU
1954e7e05452SSean Christopherson	select MMU_NOTIFIER
1955901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
195640e0e784STony Luck	select XARRAY_MULTI
1957e7e05452SSean Christopherson	help
1958e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1959e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1960e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1961e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1962e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1963e7e05452SSean Christopherson	  hardware.
1964e7e05452SSean Christopherson
1965e7e05452SSean Christopherson	  If unsure, say N.
1966e7e05452SSean Christopherson
1967506f1d07SSam Ravnborgconfig EFI
19689ba16087SJan Beulich	bool "EFI runtime service support"
19695b83683fSHuang, Ying	depends on ACPI
1970f6ce5002SSergey Vlasov	select UCS2_STRING
1971022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19721ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1973a7f7f624SMasahiro Yamada	help
19748b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1975506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1976506f1d07SSam Ravnborg
19778b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19788b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19798b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19808b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19818b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19828b2cb7a8SHuang, Ying	  platforms.
1983506f1d07SSam Ravnborg
1984291f3632SMatt Flemingconfig EFI_STUB
1985291f3632SMatt Fleming	bool "EFI stub support"
1986c6dbd3e5SPeter Zijlstra	depends on EFI
19878f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19887b2a583aSMatt Fleming	select RELOCATABLE
1989a7f7f624SMasahiro Yamada	help
1990291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1991291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1992291f3632SMatt Fleming
19934f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19940c759662SMatt Fleming
19957d453eeeSMatt Flemingconfig EFI_MIXED
19967d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19977d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1998a7f7f624SMasahiro Yamada	help
19997d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
20007d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
20017d453eeeSMatt Fleming	   mode.
20027d453eeeSMatt Fleming
20037d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
20047d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
20057d453eeeSMatt Fleming	   the EFI handover protocol must be used.
20067d453eeeSMatt Fleming
20077d453eeeSMatt Fleming	   If unsure, say N.
20087d453eeeSMatt Fleming
20098636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2010506f1d07SSam Ravnborg
2011506f1d07SSam Ravnborgconfig KEXEC
2012506f1d07SSam Ravnborg	bool "kexec system call"
20132965faa5SDave Young	select KEXEC_CORE
2014a7f7f624SMasahiro Yamada	help
2015506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2016506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2017506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2018506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2019506f1d07SSam Ravnborg
2020506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2021506f1d07SSam Ravnborg
2022506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2023506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2024bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2025bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2026bf220695SGeert Uytterhoeven	  made.
2027506f1d07SSam Ravnborg
202874ca317cSVivek Goyalconfig KEXEC_FILE
202974ca317cSVivek Goyal	bool "kexec file based system call"
20302965faa5SDave Young	select KEXEC_CORE
203174ca317cSVivek Goyal	select BUILD_BIN2C
203274ca317cSVivek Goyal	depends on X86_64
203374ca317cSVivek Goyal	depends on CRYPTO=y
203474ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2035a7f7f624SMasahiro Yamada	help
203674ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
203774ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
203874ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
203974ca317cSVivek Goyal	  accepted by previous system call.
204074ca317cSVivek Goyal
2041b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2042b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2043b799a09fSAKASHI Takahiro
204499d5cadfSJiri Bohacconfig KEXEC_SIG
20458e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
204674ca317cSVivek Goyal	depends on KEXEC_FILE
2047a7f7f624SMasahiro Yamada	help
204899d5cadfSJiri Bohac
204999d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
205099d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
205199d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
205299d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
205399d5cadfSJiri Bohac
205499d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
205599d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
205699d5cadfSJiri Bohac	  loaded in order for this to work.
205799d5cadfSJiri Bohac
205899d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
205999d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
206099d5cadfSJiri Bohac	depends on KEXEC_SIG
2061a7f7f624SMasahiro Yamada	help
20628e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2063d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20648e7d8381SVivek Goyal
20658e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20668e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
206799d5cadfSJiri Bohac	depends on KEXEC_SIG
20688e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20698e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2070a7f7f624SMasahiro Yamada	help
20718e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20728e7d8381SVivek Goyal
2073506f1d07SSam Ravnborgconfig CRASH_DUMP
207404b69447SPavel Machek	bool "kernel crash dumps"
2075506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2076a7f7f624SMasahiro Yamada	help
2077506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2078506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2079506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2080506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2081506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2082506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2083506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2084506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2085330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2086506f1d07SSam Ravnborg
20873ab83521SHuang Yingconfig KEXEC_JUMP
20886ea30386SKees Cook	bool "kexec jump"
2089fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2090a7f7f624SMasahiro Yamada	help
209189081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
209289081d17SHuang Ying	  code in physical address mode via KEXEC
20933ab83521SHuang Ying
2094506f1d07SSam Ravnborgconfig PHYSICAL_START
20956a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2096ceefccc9SH. Peter Anvin	default "0x1000000"
2097a7f7f624SMasahiro Yamada	help
2098506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2099506f1d07SSam Ravnborg
2100506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2101506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2102506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2103506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2104506f1d07SSam Ravnborg	  address.
2105506f1d07SSam Ravnborg
2106506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2107506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2108506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2109506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2110506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2111506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2112506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2113506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2114506f1d07SSam Ravnborg
2115ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2116ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2117ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2118ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2119ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2120ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2121ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2122330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2123ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2124506f1d07SSam Ravnborg
2125506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2126506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2127506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2128506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2129506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2130506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2131506f1d07SSam Ravnborg	  line.
2132506f1d07SSam Ravnborg
2133506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2134506f1d07SSam Ravnborg
2135506f1d07SSam Ravnborgconfig RELOCATABLE
213626717808SH. Peter Anvin	bool "Build a relocatable kernel"
213726717808SH. Peter Anvin	default y
2138a7f7f624SMasahiro Yamada	help
2139506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2140506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2141506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2142506f1d07SSam Ravnborg	  but are discarded at runtime.
2143506f1d07SSam Ravnborg
2144506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2145506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2146506f1d07SSam Ravnborg	  kernel.
2147506f1d07SSam Ravnborg
2148506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2149506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21508ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2151506f1d07SSam Ravnborg
21528ab3820fSKees Cookconfig RANDOMIZE_BASE
2153e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21548ab3820fSKees Cook	depends on RELOCATABLE
21556807c846SIngo Molnar	default y
2156a7f7f624SMasahiro Yamada	help
2157e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2158e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2159e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2160e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2161e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2162e8581e3dSBaoquan He	  code internals.
2163e8581e3dSBaoquan He
2164ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2165ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2166ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2167ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2168ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2169ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2170ed9f007eSKees Cook
2171ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2172ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2173ed9f007eSKees Cook	  512MB (8 bits of entropy).
21748ab3820fSKees Cook
2175a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2176e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2177e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2178ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2179ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2180ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2181ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2182ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2183ed9f007eSKees Cook	  limited due to memory layouts.
2184e8581e3dSBaoquan He
21856807c846SIngo Molnar	  If unsure, say Y.
2186da2b6fb9SKees Cook
21878ab3820fSKees Cook# Relocation on x86 needs some additional build support
2188845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2189845adf72SH. Peter Anvin	def_bool y
21908ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2191845adf72SH. Peter Anvin
2192506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2193a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21948ab3820fSKees Cook	default "0x200000"
2195a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2196a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2197a7f7f624SMasahiro Yamada	help
2198506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2199506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2200506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2201506f1d07SSam Ravnborg
2202506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2203506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2204506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2205506f1d07SSam Ravnborg
2206506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2207506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2208506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2209506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2210506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2211506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2212506f1d07SSam Ravnborg	  above alignment restrictions.
2213506f1d07SSam Ravnborg
2214a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2215a0215061SKees Cook	  this value must be a multiple of 0x200000.
2216a0215061SKees Cook
2217506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2218506f1d07SSam Ravnborg
2219eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2220eedb92abSKirill A. Shutemov	bool
2221a7f7f624SMasahiro Yamada	help
2222eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2223eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2224eedb92abSKirill A. Shutemov
22250483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22260483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22270483e1faSThomas Garnier	depends on X86_64
22280483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2229eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22300483e1faSThomas Garnier	default RANDOMIZE_BASE
2231a7f7f624SMasahiro Yamada	help
22320483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22330483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22340483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22350483e1faSThomas Garnier
22360483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22370483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22380483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22390483e1faSThomas Garnier	   addresses for each memory section.
22400483e1faSThomas Garnier
22416807c846SIngo Molnar	   If unsure, say Y.
22420483e1faSThomas Garnier
224390397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
224490397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
224590397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
224690397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
224790397a41SThomas Garnier	default "0x0"
224890397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
224990397a41SThomas Garnier	range 0x0 0x40
2250a7f7f624SMasahiro Yamada	help
225190397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
225290397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
225390397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
225490397a41SThomas Garnier	   address randomization.
225590397a41SThomas Garnier
225690397a41SThomas Garnier	   If unsure, leave at the default value.
225790397a41SThomas Garnier
2258506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2259bebd024eSThomas Gleixner	def_bool y
226040b31360SStephen Rothwell	depends on SMP
2261506f1d07SSam Ravnborg
226280aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
226380aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22642c922cd0SKees Cook	depends on HOTPLUG_CPU
2265a7f7f624SMasahiro Yamada	help
226680aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
226780aa1dffSFenghua Yu
226880aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
226980aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
227080aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
227180aa1dffSFenghua Yu
227280aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
227380aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
227480aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
227580aa1dffSFenghua Yu
227680aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
227780aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
227880aa1dffSFenghua Yu
227980aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
228080aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
228180aa1dffSFenghua Yu	  be other CPU0 dependencies.
228280aa1dffSFenghua Yu
228380aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
228480aa1dffSFenghua Yu	  you enable this feature.
228580aa1dffSFenghua Yu
228680aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
228780aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
228880aa1dffSFenghua Yu	  parameter cpu0_hotplug.
228980aa1dffSFenghua Yu
2290a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2291a71c8bc5SFenghua Yu	def_bool n
2292a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22932c922cd0SKees Cook	depends on HOTPLUG_CPU
2294a7f7f624SMasahiro Yamada	help
2295a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2296a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2297a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2298a71c8bc5SFenghua Yu
2299a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2300a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2301a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2302a71c8bc5SFenghua Yu
2303a71c8bc5SFenghua Yu	  If unsure, say N.
2304a71c8bc5SFenghua Yu
2305506f1d07SSam Ravnborgconfig COMPAT_VDSO
2306b0b49f26SAndy Lutomirski	def_bool n
2307b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2308953fee1dSIngo Molnar	depends on COMPAT_32
2309a7f7f624SMasahiro Yamada	help
2310b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2311b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2312b0b49f26SAndy Lutomirski	  indicated in its segment table.
2313e84446deSRandy Dunlap
2314b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2315b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2316b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2317b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2318b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2319506f1d07SSam Ravnborg
2320b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2321b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2322b0b49f26SAndy Lutomirski
2323b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2324b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2325b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2326b0b49f26SAndy Lutomirski
2327b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2328b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2329506f1d07SSam Ravnborg
23303dc33bd3SKees Cookchoice
23313dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23323dc33bd3SKees Cook	depends on X86_64
2333625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23343dc33bd3SKees Cook	help
23353dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23363dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23373dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23383dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23393dc33bd3SKees Cook
23403dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2341bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23423dc33bd3SKees Cook
23433dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23443dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23453dc33bd3SKees Cook	  to improve security.
23463dc33bd3SKees Cook
2347bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23483dc33bd3SKees Cook
23493dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2350bd49e16eSAndy Lutomirski		bool "Full emulation"
23513dc33bd3SKees Cook		help
2352bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2353bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2354bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2355bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2356bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2357bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2358bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2359bd49e16eSAndy Lutomirski
2360bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2361bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2362bd49e16eSAndy Lutomirski
2363bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2364bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2365bd49e16eSAndy Lutomirski		help
2366bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2367bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2368bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2369bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2370bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2371bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2372bd49e16eSAndy Lutomirski		  buffer.
23733dc33bd3SKees Cook
23743dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23753dc33bd3SKees Cook		bool "None"
23763dc33bd3SKees Cook		help
23773dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23783dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23793dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23803dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23813dc33bd3SKees Cook		  malicious userspace programs can be identified.
23823dc33bd3SKees Cook
23833dc33bd3SKees Cookendchoice
23843dc33bd3SKees Cook
2385516cbf37STim Birdconfig CMDLINE_BOOL
2386516cbf37STim Bird	bool "Built-in kernel command line"
2387a7f7f624SMasahiro Yamada	help
2388516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2389516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2390516cbf37STim Bird	  necessary or convenient to provide some or all of the
2391516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2392516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2393516cbf37STim Bird
2394516cbf37STim Bird	  To compile command line arguments into the kernel,
2395516cbf37STim Bird	  set this option to 'Y', then fill in the
239669711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2397516cbf37STim Bird
2398516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2399516cbf37STim Bird	  should leave this option set to 'N'.
2400516cbf37STim Bird
2401516cbf37STim Birdconfig CMDLINE
2402516cbf37STim Bird	string "Built-in kernel command string"
2403516cbf37STim Bird	depends on CMDLINE_BOOL
2404516cbf37STim Bird	default ""
2405a7f7f624SMasahiro Yamada	help
2406516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2407516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2408516cbf37STim Bird	  command line at boot time, it is appended to this string to
2409516cbf37STim Bird	  form the full kernel command line, when the system boots.
2410516cbf37STim Bird
2411516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2412516cbf37STim Bird	  change this behavior.
2413516cbf37STim Bird
2414516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2415516cbf37STim Bird	  by the boot loader) should specify the device for the root
2416516cbf37STim Bird	  file system.
2417516cbf37STim Bird
2418516cbf37STim Birdconfig CMDLINE_OVERRIDE
2419516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2420645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2421a7f7f624SMasahiro Yamada	help
2422516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2423516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2424516cbf37STim Bird
2425516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2426516cbf37STim Bird	  be set to 'N' under normal conditions.
2427516cbf37STim Bird
2428a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2429a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2430a5b9e5a2SAndy Lutomirski	default y
2431a7f7f624SMasahiro Yamada	help
2432a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2433a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2434a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2435a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2436a5b9e5a2SAndy Lutomirski	  threading libraries.
2437a5b9e5a2SAndy Lutomirski
2438a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2439a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2440a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2441a5b9e5a2SAndy Lutomirski
2442a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2443a5b9e5a2SAndy Lutomirski
24443aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24453aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24463aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24473aac3ebeSThomas Gleixner	help
24483aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24493aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24503aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24513aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24523aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24533aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24543aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24553aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24563aac3ebeSThomas Gleixner	  never get a signal delivered.
24573aac3ebeSThomas Gleixner
24583aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24593aac3ebeSThomas Gleixner
2460b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2461b700e7f0SSeth Jennings
2462506f1d07SSam Ravnborgendmenu
2463506f1d07SSam Ravnborg
24643072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24653072e413SMichal Hocko	def_bool y
24665c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24673072e413SMichal Hocko
2468f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2469f91ef222SOscar Salvador	def_bool y
2470f91ef222SOscar Salvador
2471da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2472e279b6c1SSam Ravnborg
2473e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24743c2362e6SHarvey Harrison	def_bool y
247544556530SZhimin Gu	depends on HIBERNATION
2476e279b6c1SSam Ravnborg
2477e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2478e279b6c1SSam Ravnborg
2479e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2480e279b6c1SSam Ravnborg
2481a6b68076SAndi Kleenconfig X86_APM_BOOT
24826fc108a0SJan Beulich	def_bool y
2483282e5aabSPaul Bolle	depends on APM
2484a6b68076SAndi Kleen
2485e279b6c1SSam Ravnborgmenuconfig APM
2486e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2487efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2488a7f7f624SMasahiro Yamada	help
2489e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2490e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2491e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2492e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2493e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2494e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2495e279b6c1SSam Ravnborg
2496e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2497e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2498e279b6c1SSam Ravnborg
2499e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2500e279b6c1SSam Ravnborg	  machines with more than one CPU.
2501e279b6c1SSam Ravnborg
2502e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2503151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
25042dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2505e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2506e279b6c1SSam Ravnborg
2507e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2508e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2509e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2510e279b6c1SSam Ravnborg
2511e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2512e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2513e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2514e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2515e279b6c1SSam Ravnborg
2516e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2517e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2518e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2519e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2520e279b6c1SSam Ravnborg	  APM in your BIOS).
2521e279b6c1SSam Ravnborg
2522e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2523e279b6c1SSam Ravnborg	  "weird" problems:
2524e279b6c1SSam Ravnborg
2525e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2526e279b6c1SSam Ravnborg	  enabled.
2527e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2528e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2529e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2530e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2531e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2532e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2533e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2534e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2535e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2536e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2537e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2538e279b6c1SSam Ravnborg	  11) exchange RAM chips
2539e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2540e279b6c1SSam Ravnborg
2541e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2542e279b6c1SSam Ravnborg	  module will be called apm.
2543e279b6c1SSam Ravnborg
2544e279b6c1SSam Ravnborgif APM
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2547e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2548a7f7f624SMasahiro Yamada	help
2549e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2550e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2551e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2552e279b6c1SSam Ravnborg
2553e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2554e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2555a7f7f624SMasahiro Yamada	help
2556e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2557e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2558e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2559e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2560e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2561e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2562e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2563e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2564e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2565e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2566e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2567e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2568e279b6c1SSam Ravnborg	  this feature.
2569e279b6c1SSam Ravnborg
2570e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2571dd8af076SLen Brown	depends on CPU_IDLE
2572e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2573a7f7f624SMasahiro Yamada	help
2574e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2575e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2576e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2577e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2578e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2579e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2580e279b6c1SSam Ravnborg	  this option does nothing.)
2581e279b6c1SSam Ravnborg
2582e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2583e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2584a7f7f624SMasahiro Yamada	help
2585e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2586e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2587e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2588e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2589e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2590e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2591e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2592e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2593e279b6c1SSam Ravnborg	  especially if you are using gpm.
2594e279b6c1SSam Ravnborg
2595e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2596e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2597a7f7f624SMasahiro Yamada	help
2598e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2599e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2600e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2601e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2602e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2603e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2604e279b6c1SSam Ravnborg
2605e279b6c1SSam Ravnborgendif # APM
2606e279b6c1SSam Ravnborg
2607bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2608e279b6c1SSam Ravnborg
2609e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2610e279b6c1SSam Ravnborg
261127471fdbSAndy Henroidsource "drivers/idle/Kconfig"
261227471fdbSAndy Henroid
2613e279b6c1SSam Ravnborgendmenu
2614e279b6c1SSam Ravnborg
2615e279b6c1SSam Ravnborg
2616e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2617e279b6c1SSam Ravnborg
2618e279b6c1SSam Ravnborgchoice
2619e279b6c1SSam Ravnborg	prompt "PCI access mode"
2620efefa6f6SIngo Molnar	depends on X86_32 && PCI
2621e279b6c1SSam Ravnborg	default PCI_GOANY
2622a7f7f624SMasahiro Yamada	help
2623e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2624e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2625e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2626e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2627e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2628e279b6c1SSam Ravnborg
2629e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2630e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2631e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2632e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2633e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2634e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2635e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2636e279b6c1SSam Ravnborg
2637e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2638e279b6c1SSam Ravnborg	bool "BIOS"
2639e279b6c1SSam Ravnborg
2640e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2641e279b6c1SSam Ravnborg	bool "MMConfig"
2642e279b6c1SSam Ravnborg
2643e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2644e279b6c1SSam Ravnborg	bool "Direct"
2645e279b6c1SSam Ravnborg
26463ef0e1f8SAndres Salomonconfig PCI_GOOLPC
264776fb6570SDaniel Drake	bool "OLPC XO-1"
26483ef0e1f8SAndres Salomon	depends on OLPC
26493ef0e1f8SAndres Salomon
26502bdd1b03SAndres Salomonconfig PCI_GOANY
26512bdd1b03SAndres Salomon	bool "Any"
26522bdd1b03SAndres Salomon
2653e279b6c1SSam Ravnborgendchoice
2654e279b6c1SSam Ravnborg
2655e279b6c1SSam Ravnborgconfig PCI_BIOS
26563c2362e6SHarvey Harrison	def_bool y
2657efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2658e279b6c1SSam Ravnborg
2659e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2660e279b6c1SSam Ravnborgconfig PCI_DIRECT
26613c2362e6SHarvey Harrison	def_bool y
26620aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2663e279b6c1SSam Ravnborg
2664e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2665b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2666b45c9f36SJan Kiszka	default y
26674590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2668b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2669e279b6c1SSam Ravnborg
26703ef0e1f8SAndres Salomonconfig PCI_OLPC
26712bdd1b03SAndres Salomon	def_bool y
26722bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26733ef0e1f8SAndres Salomon
2674b5401a96SAlex Nixonconfig PCI_XEN
2675b5401a96SAlex Nixon	def_bool y
2676b5401a96SAlex Nixon	depends on PCI && XEN
2677b5401a96SAlex Nixon
26788364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26798364e1f8SJan Kiszka	def_bool y
26808364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2681e279b6c1SSam Ravnborg
26823f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26836a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26846ea30386SKees Cook	depends on PCI
26853f6ea84aSIra W. Snyder	help
26863f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26873f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26883f6ea84aSIra W. Snyder	  not have ACPI.
26893f6ea84aSIra W. Snyder
269064a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
269164a5fed6SBjorn Helgaas	  is known to be incomplete.
269264a5fed6SBjorn Helgaas
269364a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
269464a5fed6SBjorn Helgaas
26953a495511SWilliam Breathitt Grayconfig ISA_BUS
269617a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26973a495511SWilliam Breathitt Gray	help
269817a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
269917a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
270017a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
270117a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
270217a2a129SWilliam Breathitt Gray	  not have an ISA bus.
27033a495511SWilliam Breathitt Gray
27043a495511SWilliam Breathitt Gray	  If unsure, say N.
27053a495511SWilliam Breathitt Gray
27061c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2707e279b6c1SSam Ravnborgconfig ISA_DMA_API
27081c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27091c00f016SDavid Rientjes	default y
27101c00f016SDavid Rientjes	help
27111c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27121c00f016SDavid Rientjes	  If unsure, say Y.
2713e279b6c1SSam Ravnborg
271451e68d05SLinus Torvaldsif X86_32
271551e68d05SLinus Torvalds
2716e279b6c1SSam Ravnborgconfig ISA
2717e279b6c1SSam Ravnborg	bool "ISA support"
2718a7f7f624SMasahiro Yamada	help
2719e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2720e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2721e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2722e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2723e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2724e279b6c1SSam Ravnborg
2725e279b6c1SSam Ravnborgconfig SCx200
2726e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2727a7f7f624SMasahiro Yamada	help
2728e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2729e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2730e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2731e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2732e279b6c1SSam Ravnborg
2733e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2734e279b6c1SSam Ravnborg
2735e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2736e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2737592913ecSJohn Stultz	depends on SCx200
2738e279b6c1SSam Ravnborg	default y
2739a7f7f624SMasahiro Yamada	help
2740e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2741e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2742e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2743e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2744e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2745e279b6c1SSam Ravnborg
27463ef0e1f8SAndres Salomonconfig OLPC
27473ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274854008979SThomas Gleixner	depends on !X86_PAE
27493c554946SAndres Salomon	select GPIOLIB
2750dc3119e7SThomas Gleixner	select OF
275145bb1674SDaniel Drake	select OF_PROMTREE
2752b4e51854SGrant Likely	select IRQ_DOMAIN
27530c3d931bSLubomir Rintel	select OLPC_EC
2754a7f7f624SMasahiro Yamada	help
27553ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27563ef0e1f8SAndres Salomon	  XO hardware.
27573ef0e1f8SAndres Salomon
2758a3128588SDaniel Drakeconfig OLPC_XO1_PM
2759a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2760fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2761a7f7f624SMasahiro Yamada	help
276297c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2763bf1ebf00SDaniel Drake
2764cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2765cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2766cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2767a7f7f624SMasahiro Yamada	help
2768cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2769cfee9597SDaniel Drake	  programmable wakeup source.
2770cfee9597SDaniel Drake
27717feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27727feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
277392e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2774ed8e47feSRandy Dunlap	depends on INPUT=y
2775d8d01a63SDaniel Drake	select POWER_SUPPLY
2776a7f7f624SMasahiro Yamada	help
27777feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27787bc74b3dSDaniel Drake	   - EC-driven system wakeups
27797feda8e9SDaniel Drake	   - Power button
27807bc74b3dSDaniel Drake	   - Ebook switch
27812cf2baeaSDaniel Drake	   - Lid switch
2782e1040ac6SDaniel Drake	   - AC adapter status updates
2783e1040ac6SDaniel Drake	   - Battery status updates
27847feda8e9SDaniel Drake
2785a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2786a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2787d8d01a63SDaniel Drake	depends on OLPC && ACPI
2788d8d01a63SDaniel Drake	select POWER_SUPPLY
2789a7f7f624SMasahiro Yamada	help
2790a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2791a0f30f59SDaniel Drake	   - EC-driven system wakeups
2792a0f30f59SDaniel Drake	   - AC adapter status updates
2793a0f30f59SDaniel Drake	   - Battery status updates
2794e279b6c1SSam Ravnborg
2795d4f3e350SEd Wildgooseconfig ALIX
2796d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2797d4f3e350SEd Wildgoose	select GPIOLIB
2798a7f7f624SMasahiro Yamada	help
2799d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2800d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2801d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2802d4f3e350SEd Wildgoose	  get added here.
2803d4f3e350SEd Wildgoose
2804d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2805d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2806d4f3e350SEd Wildgoose
2807d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2808d4f3e350SEd Wildgoose
2809da4e3302SPhilip Prindevilleconfig NET5501
2810da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2811da4e3302SPhilip Prindeville	select GPIOLIB
2812a7f7f624SMasahiro Yamada	help
2813da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2814da4e3302SPhilip Prindeville
28153197059aSPhilip A. Prindevilleconfig GEOS
28163197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28173197059aSPhilip A. Prindeville	select GPIOLIB
28183197059aSPhilip A. Prindeville	depends on DMI
2819a7f7f624SMasahiro Yamada	help
28203197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28213197059aSPhilip A. Prindeville
28227d029125SVivien Didelotconfig TS5500
28237d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28247d029125SVivien Didelot	depends on MELAN
28257d029125SVivien Didelot	select CHECK_SIGNATURE
28267d029125SVivien Didelot	select NEW_LEDS
28277d029125SVivien Didelot	select LEDS_CLASS
2828a7f7f624SMasahiro Yamada	help
28297d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28307d029125SVivien Didelot
2831e279b6c1SSam Ravnborgendif # X86_32
2832e279b6c1SSam Ravnborg
283323ac4ae8SAndreas Herrmannconfig AMD_NB
2834e279b6c1SSam Ravnborg	def_bool y
28350e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2836e279b6c1SSam Ravnborg
2837e279b6c1SSam Ravnborgendmenu
2838e279b6c1SSam Ravnborg
2839e279b6c1SSam Ravnborg
28401572497cSChristoph Hellwigmenu "Binary Emulations"
2841e279b6c1SSam Ravnborg
2842e279b6c1SSam Ravnborgconfig IA32_EMULATION
2843e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2844e279b6c1SSam Ravnborg	depends on X86_64
284539f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2846d1603990SRandy Dunlap	select BINFMT_ELF
284739f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2848a7f7f624SMasahiro Yamada	help
28495fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28505fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28515fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2852e279b6c1SSam Ravnborg
2853e279b6c1SSam Ravnborgconfig IA32_AOUT
2854e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28556b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2856eac61655SBorislav Petkov	depends on BROKEN
2857a7f7f624SMasahiro Yamada	help
2858e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2859e279b6c1SSam Ravnborg
286083a44a4fSMasahiro Yamadaconfig X86_X32_ABI
28616ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28629b54050bSBrian Gerst	depends on X86_64
2863aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2864aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
2865aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
2866aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
2867aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2868a7f7f624SMasahiro Yamada	help
28695fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28705fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28715fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28725fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28735fd92e65SH. J. Lu
2874953fee1dSIngo Molnarconfig COMPAT_32
2875953fee1dSIngo Molnar	def_bool y
2876953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2877953fee1dSIngo Molnar	select HAVE_UID16
2878953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2879953fee1dSIngo Molnar
2880e279b6c1SSam Ravnborgconfig COMPAT
28813c2362e6SHarvey Harrison	def_bool y
288283a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
2883e279b6c1SSam Ravnborg
28843120e25eSJan Beulichif COMPAT
2885e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28863120e25eSJan Beulich	def_bool y
2887e279b6c1SSam Ravnborg
2888e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28893c2362e6SHarvey Harrison	def_bool y
28903120e25eSJan Beulich	depends on SYSVIPC
28913120e25eSJan Beulichendif
2892ee009e4aSDavid Howells
2893e279b6c1SSam Ravnborgendmenu
2894e279b6c1SSam Ravnborg
2895e279b6c1SSam Ravnborg
2896e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2897e5beae16SKeith Packard	def_bool y
2898e5beae16SKeith Packard	depends on X86_32
2899e5beae16SKeith Packard
2900edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
29015e8ebd84SJason A. Donenfeld
29025e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2903