xref: /linux/arch/x86/Kconfig (revision 4510bffb4d0246cdcc1f14c7367c026b807a862d)
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
796974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
80957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
81bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
820c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
840ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
873010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
880aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
89ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
90d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
91d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
92ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
94ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
96c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
97e10cd4b0SChristoph Hellwig	select ARCH_HAS_VM_GET_PAGE_PROT
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
12447010c04SMuchun Song	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
12559612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12638d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
127b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12810916706SShile Zhang	select BUILDTIME_TABLE_SORT
1296471b825SIngo Molnar	select CLKEVT_I8253
1306471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1316471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1326471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1333aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13445471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13545471cd9SLinus Torvalds	select EDAC_SUPPORT
1366471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1376471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1386471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1396471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
14061dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1416471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14227d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1436471b825SIngo Molnar	select GENERIC_IOMAP
144c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1450fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
146ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1476471b825SIngo Molnar	select GENERIC_IRQ_PROBE
148c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1496471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1506471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1512ae27137SSteven Price	select GENERIC_PTDUMP
1526471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1536471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1547ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
155550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15639656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15717e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1587edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1596471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1606471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1616471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1626471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1636471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
164eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1656471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
166b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
167d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1680609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1691dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1706471b825SIngo Molnar	select HAVE_ARCH_KGDB
1719e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1729e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1731b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
174271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1756471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
176f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
177afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1786471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1796471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
180a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
181b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1827677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
183e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
184fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
185c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1862ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1876471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1886471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1896471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
190d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1916471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
19203f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
1934ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
1946471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1959c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
196677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19706aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19802a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
199562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
200c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
201503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
20203f5781bSWang YanQing	select HAVE_EBPF_JIT
20358340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2046630a8e5SChristoph Hellwig	select HAVE_EISA
2055f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20667a929e0SChristoph Hellwig	select HAVE_FAST_GUP
207644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2086471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2094a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2106471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2116b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2120067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2136471b825SIngo Molnar	select HAVE_IOREMAP_PROT
214624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2156471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2164ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2176471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2186471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2196471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2206471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2216471b825SIngo Molnar	select HAVE_KERNEL_LZO
2226471b825SIngo Molnar	select HAVE_KERNEL_XZ
223fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2246471b825SIngo Molnar	select HAVE_KPROBES
2256471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
226540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2276471b825SIngo Molnar	select HAVE_KRETPROBES
228f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2296471b825SIngo Molnar	select HAVE_KVM
2306471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2310102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
232ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2339f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
234be37c98dSKalesh Singh	select HAVE_MOVE_PUD
23522102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
23642a0bb3fSPetr Mladek	select HAVE_NMI
237489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
23803f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2396471b825SIngo Molnar	select HAVE_OPTPROBES
2406471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2416471b825SIngo Molnar	select HAVE_PERF_EVENTS
242c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
24392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
244eb01d42aSChristoph Hellwig	select HAVE_PCI
245c5e63197SJiri Olsa	select HAVE_PERF_REGS
246c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
247ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
24800998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2496471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
25003f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2513c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2527ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
253cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
254d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
25503f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
256e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
25703f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
25899cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
259d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2606471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2615f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2626471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2637c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2647ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
26505736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
266c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2677ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2687ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
26986596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2702eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
271625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2726471b825SIngo Molnar	select PERF_EVENTS
2733195ef59SPrarit Bhargava	select RTC_LIB
274d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2756471b825SIngo Molnar	select SPARSE_IRQ
27683fe27eaSPranith Kumar	select SRCU
2776471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
27815f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2794aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
280*4510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
2816471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2826471b825SIngo Molnar	select VIRT_TO_BUS
2833b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2846471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2850c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
28650468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
2879e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2887d8330a5SBalbir Singh
289ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2903120e25eSJan Beulich	def_bool y
2913120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
292ba7e4d13SIngo Molnar
29351b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
29451b26adaSLinus Torvalds	string
29551b26adaSLinus Torvalds	default "elf32-i386" if X86_32
29651b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
29751b26adaSLinus Torvalds
2988d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2993c2362e6SHarvey Harrison	def_bool y
3008d5fffb9SSam Ravnborg
3018d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3023c2362e6SHarvey Harrison	def_bool y
3038d5fffb9SSam Ravnborg
3048d5fffb9SSam Ravnborgconfig MMU
3053c2362e6SHarvey Harrison	def_bool y
3068d5fffb9SSam Ravnborg
3079e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3089e08f57dSDaniel Cashman	default 28 if 64BIT
3099e08f57dSDaniel Cashman	default 8
3109e08f57dSDaniel Cashman
3119e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3129e08f57dSDaniel Cashman	default 32 if 64BIT
3139e08f57dSDaniel Cashman	default 16
3149e08f57dSDaniel Cashman
3159e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3169e08f57dSDaniel Cashman	default 8
3179e08f57dSDaniel Cashman
3189e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3199e08f57dSDaniel Cashman	default 16
3209e08f57dSDaniel Cashman
3218d5fffb9SSam Ravnborgconfig SBUS
3228d5fffb9SSam Ravnborg	bool
3238d5fffb9SSam Ravnborg
3248d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3253120e25eSJan Beulich	def_bool y
3263120e25eSJan Beulich	depends on ISA_DMA_API
3278d5fffb9SSam Ravnborg
3288d5fffb9SSam Ravnborgconfig GENERIC_BUG
3293c2362e6SHarvey Harrison	def_bool y
3308d5fffb9SSam Ravnborg	depends on BUG
331b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
332b93a531eSJan Beulich
333b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
334b93a531eSJan Beulich	bool
3358d5fffb9SSam Ravnborg
3368d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3373120e25eSJan Beulich	def_bool y
3383120e25eSJan Beulich	depends on ISA_DMA_API
3398d5fffb9SSam Ravnborg
3401032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3411032c0baSSam Ravnborg	def_bool y
3421032c0baSSam Ravnborg
3439a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3449a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3458d5fffb9SSam Ravnborg
346801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
347801e4062SJohannes Berg	def_bool y
348801e4062SJohannes Berg
349d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
350d7109fe3SAndy Shevchenko	int
351d7109fe3SAndy Shevchenko	default 1024 if X86_64
352d7109fe3SAndy Shevchenko	default 512
353d7109fe3SAndy Shevchenko
354f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
355f4cb5700SJohannes Berg	def_bool y
356f4cb5700SJohannes Berg
3578d5fffb9SSam Ravnborgconfig AUDIT_ARCH
358e0fd24a3SJan Beulich	def_bool y if X86_64
3598d5fffb9SSam Ravnborg
360d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
361d6f2d75aSAndrey Ryabinin	hex
362d6f2d75aSAndrey Ryabinin	depends on KASAN
363d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
364d6f2d75aSAndrey Ryabinin
36569575d38SShane Wangconfig HAVE_INTEL_TXT
36669575d38SShane Wang	def_bool y
3676ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
36869575d38SShane Wang
3696b0c3d44SSam Ravnborgconfig X86_32_SMP
3706b0c3d44SSam Ravnborg	def_bool y
3716b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3726b0c3d44SSam Ravnborg
3736b0c3d44SSam Ravnborgconfig X86_64_SMP
3746b0c3d44SSam Ravnborg	def_bool y
3756b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3766b0c3d44SSam Ravnborg
3772b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3782b144498SSrikar Dronamraju	def_bool y
3792b144498SSrikar Dronamraju
380d20642f0SRob Herringconfig FIX_EARLYCON_MEM
381d20642f0SRob Herring	def_bool y
382d20642f0SRob Herring
38394d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
38494d49eb3SKirill A. Shutemov	bool
38594d49eb3SKirill A. Shutemov
38698233368SKirill A. Shutemovconfig PGTABLE_LEVELS
38798233368SKirill A. Shutemov	int
38877ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
38998233368SKirill A. Shutemov	default 4 if X86_64
39098233368SKirill A. Shutemov	default 3 if X86_PAE
39198233368SKirill A. Shutemov	default 2
39298233368SKirill A. Shutemov
3932a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
3942a61f474SMasahiro Yamada	bool
3952a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
3962a61f474SMasahiro Yamada	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
3972a61f474SMasahiro Yamada	help
3982a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
3993fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4003fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4012a61f474SMasahiro Yamada
402506f1d07SSam Ravnborgmenu "Processor type and features"
403506f1d07SSam Ravnborg
404506f1d07SSam Ravnborgconfig SMP
405506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
406a7f7f624SMasahiro Yamada	help
407506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4084a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4094a474157SRobert Graffham	  than one CPU, say Y.
410506f1d07SSam Ravnborg
4114a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
412506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
413506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4144a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
415506f1d07SSam Ravnborg	  will run faster if you say N here.
416506f1d07SSam Ravnborg
417506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
418506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
419506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
420506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
421506f1d07SSam Ravnborg
422506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
423506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
424506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
425506f1d07SSam Ravnborg
426cb1aaebeSMauro Carvalho Chehab	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
4274f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
428506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
429506f1d07SSam Ravnborg
430506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
431506f1d07SSam Ravnborg
4329def39beSJosh Triplettconfig X86_FEATURE_NAMES
4339def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4349def39beSJosh Triplett	default y
435a7f7f624SMasahiro Yamada	help
4369def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4379def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4389def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4399def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4409def39beSJosh Triplett
4419def39beSJosh Triplett	  If in doubt, say Y.
4429def39beSJosh Triplett
44306cd9a7dSYinghai Luconfig X86_X2APIC
44406cd9a7dSYinghai Lu	bool "Support x2apic"
44519e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
446a7f7f624SMasahiro Yamada	help
44706cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
44806cd9a7dSYinghai Lu
44906cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
45006cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
45106cd9a7dSYinghai Lu
45206cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
45306cd9a7dSYinghai Lu
4546695c85bSYinghai Luconfig X86_MPPARSE
4554590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4567a527688SJan Beulich	default y
4575ab74722SIngo Molnar	depends on X86_LOCAL_APIC
458a7f7f624SMasahiro Yamada	help
4596695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4606695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4616695c85bSYinghai Lu
462ddd70cf9SJun Nakajimaconfig GOLDFISH
463ddd70cf9SJun Nakajima	def_bool y
464ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
465ddd70cf9SJun Nakajima
46676b04384SDavid Woodhouseconfig RETPOLINE
46776b04384SDavid Woodhouse	bool "Avoid speculative indirect branches in kernel"
46803f16cd0SJosh Poimboeuf	select OBJTOOL if HAVE_OBJTOOL
46976b04384SDavid Woodhouse	default y
47076b04384SDavid Woodhouse	help
47176b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
47276b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
47376b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
47476b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
47576b04384SDavid Woodhouse
476e463a09aSPeter Zijlstraconfig CC_HAS_SLS
477e463a09aSPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
478e463a09aSPeter Zijlstra
479e463a09aSPeter Zijlstraconfig SLS
480e463a09aSPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
481e463a09aSPeter Zijlstra	depends on CC_HAS_SLS && X86_64
48203f16cd0SJosh Poimboeuf	select OBJTOOL if HAVE_OBJTOOL
483e463a09aSPeter Zijlstra	default n
484e463a09aSPeter Zijlstra	help
485e463a09aSPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
486e463a09aSPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
487e463a09aSPeter Zijlstra	  larger.
488e463a09aSPeter Zijlstra
489e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
490e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4916fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
49259fe5a77SThomas Gleixner	select KERNFS
493e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
49478e99b4aSFenghua Yu	help
495e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4966fe07ce3SBabu Moger
4976fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4986fe07ce3SBabu Moger	  usage by the CPU.
4996fe07ce3SBabu Moger
5006fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
5016fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
5026fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
5036fe07ce3SBabu Moger
5046fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
5056fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
5066fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50778e99b4aSFenghua Yu
50878e99b4aSFenghua Yu	  Say N if unsure.
50978e99b4aSFenghua Yu
5108425091fSRavikiran G Thirumalaiif X86_32
511a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
512a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
513a0d0bb4dSRandy Dunlap	depends on SMP
514a7f7f624SMasahiro Yamada	help
515e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
516a0d0bb4dSRandy Dunlap
517c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
518c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
519c5c606d9SRavikiran G Thirumalai	default y
520a7f7f624SMasahiro Yamada	help
52106ac8346SIngo Molnar	  If you disable this option then the kernel will only support
52206ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
52306ac8346SIngo Molnar	  systems out there.)
52406ac8346SIngo Molnar
5258425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5268425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
527cb7b8023SBen Hutchings		Goldfish (Android emulator)
5288425091fSRavikiran G Thirumalai		AMD Elan
5298425091fSRavikiran G Thirumalai		RDC R-321x SoC
5308425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
53183125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5323f4110a4SThomas Gleixner		Moorestown MID devices
53306ac8346SIngo Molnar
53406ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
53506ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
536758cd94aSJuerg Haefligerendif # X86_32
53706ac8346SIngo Molnar
5388425091fSRavikiran G Thirumalaiif X86_64
5398425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5408425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5418425091fSRavikiran G Thirumalai	default y
542a7f7f624SMasahiro Yamada	help
5438425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5448425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5458425091fSRavikiran G Thirumalai	  systems out there.)
5468425091fSRavikiran G Thirumalai
5478425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5488425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54944b111b5SSteffen Persvold		Numascale NumaChip
5508425091fSRavikiran G Thirumalai		ScaleMP vSMP
5518425091fSRavikiran G Thirumalai		SGI Ultraviolet
5528425091fSRavikiran G Thirumalai
5538425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5548425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
555758cd94aSJuerg Haefligerendif # X86_64
556c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
557c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55844b111b5SSteffen Persvoldconfig X86_NUMACHIP
55944b111b5SSteffen Persvold	bool "Numascale NumaChip"
56044b111b5SSteffen Persvold	depends on X86_64
56144b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
56244b111b5SSteffen Persvold	depends on NUMA
56344b111b5SSteffen Persvold	depends on SMP
56444b111b5SSteffen Persvold	depends on X86_X2APIC
565f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
566a7f7f624SMasahiro Yamada	help
56744b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56844b111b5SSteffen Persvold	  enable more than ~168 cores.
56944b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
57003b48632SNick Piggin
5716a48565eSIngo Molnarconfig X86_VSMP
572c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5736276a074SBorislav Petkov	select HYPERVISOR_GUEST
5746a48565eSIngo Molnar	select PARAVIRT
5756a48565eSIngo Molnar	depends on X86_64 && PCI
576c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
577ead91d4bSShai Fultheim	depends on SMP
578a7f7f624SMasahiro Yamada	help
5796a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5806a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5816a48565eSIngo Molnar	  if you have one of these machines.
5826a48565eSIngo Molnar
583c5c606d9SRavikiran G Thirumalaiconfig X86_UV
584c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
585c5c606d9SRavikiran G Thirumalai	depends on X86_64
586c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58754c28d29SJack Steiner	depends on NUMA
5881ecb4ae5SAndrew Morton	depends on EFI
589c2209ea5SIngo Molnar	depends on KEXEC_CORE
5909d6c26e7SSuresh Siddha	depends on X86_X2APIC
5911222e564SIngo Molnar	depends on PCI
592a7f7f624SMasahiro Yamada	help
593c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
594c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
595c5c606d9SRavikiran G Thirumalai
596c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
597c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
598506f1d07SSam Ravnborg
599ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
600ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
601cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
602a7f7f624SMasahiro Yamada	help
603ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
604ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
605ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
606ddd70cf9SJun Nakajima
607c751e17bSThomas Gleixnerconfig X86_INTEL_CE
608c751e17bSThomas Gleixner	bool "CE4100 TV platform"
609c751e17bSThomas Gleixner	depends on PCI
610c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6116084a6e2SJiang Liu	depends on X86_IO_APIC
612c751e17bSThomas Gleixner	depends on X86_32
613c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
61437bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
615da6b737bSSebastian Andrzej Siewior	select OF
616da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
617a7f7f624SMasahiro Yamada	help
618c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
619c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
620c751e17bSThomas Gleixner	  boxes and media devices.
621c751e17bSThomas Gleixner
6224cb9b00fSDavid Cohenconfig X86_INTEL_MID
62343605ef1SAlan Cox	bool "Intel MID platform support"
62443605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
625edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6261ea7c673SAlan Cox	depends on PCI
6273fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6281ea7c673SAlan Cox	depends on X86_IO_APIC
6294cb9b00fSDavid Cohen	select I2C
6307c9c3a1eSAlan Cox	select DW_APB_TIMER
63154b34aa0SMika Westerberg	select INTEL_SCU_PCI
632a7f7f624SMasahiro Yamada	help
6334cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6344cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6354cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6361ea7c673SAlan Cox
6374cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6384cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63943605ef1SAlan Cox
6408bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6418bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6428bbc2a13SBryan O'Donoghue	depends on X86_32
6438bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6448bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6458bbc2a13SBryan O'Donoghue	depends on X86_TSC
6468bbc2a13SBryan O'Donoghue	depends on PCI
6478bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6488bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6498bbc2a13SBryan O'Donoghue	select IOSF_MBI
6508bbc2a13SBryan O'Donoghue	select INTEL_IMR
6519ab6eb51SAndy Shevchenko	select COMMON_CLK
652a7f7f624SMasahiro Yamada	help
6538bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6548bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6558bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6568bbc2a13SBryan O'Donoghue
6573d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6583d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6595962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6603d48aab1SMika Westerberg	select COMMON_CLK
6610f531431SMathias Nyman	select PINCTRL
662eebb3e8dSAndy Shevchenko	select IOSF_MBI
663a7f7f624SMasahiro Yamada	help
6643d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6653d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6660f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6670f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6683d48aab1SMika Westerberg
66992082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
67092082a88SKen Xue	bool "AMD ACPI2Platform devices support"
67192082a88SKen Xue	depends on ACPI
67292082a88SKen Xue	select COMMON_CLK
67392082a88SKen Xue	select PINCTRL
674a7f7f624SMasahiro Yamada	help
67592082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
67692082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67792082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67892082a88SKen Xue	  implemented under PINCTRL subsystem.
67992082a88SKen Xue
680ced3ce76SDavid E. Boxconfig IOSF_MBI
681ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
682ced3ce76SDavid E. Box	depends on PCI
683a7f7f624SMasahiro Yamada	help
684ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
685ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
686ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
687ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
688ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
689ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
690ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
691ced3ce76SDavid E. Box	   - BayTrail
692ced3ce76SDavid E. Box	   - Braswell
693ced3ce76SDavid E. Box	   - Quark
694ced3ce76SDavid E. Box
695ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
696ced3ce76SDavid E. Box
697ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
698ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
699ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
700a7f7f624SMasahiro Yamada	help
701ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
702ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
703ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
704ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
705ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
706ed2226bdSDavid E. Box	  device they want to access.
707ed2226bdSDavid E. Box
708ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
709ed2226bdSDavid E. Box
710c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
711c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
712506f1d07SSam Ravnborg	depends on X86_32
713c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
714c5c606d9SRavikiran G Thirumalai	select M486
715c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
716a7f7f624SMasahiro Yamada	help
717c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
718c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
719c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
720c5c606d9SRavikiran G Thirumalai
721e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7229c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7239c398017SIngo Molnar	depends on X86_32 && SMP
724c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
725a7f7f624SMasahiro Yamada	help
726b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
727b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
728b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
729b5660ba7SH. Peter Anvin	  one and will fallback to default.
730d49c4288SYinghai Lu
731c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
732d49c4288SYinghai Lu
733d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7346fc108a0SJan Beulich	def_bool y
735d949f36fSLinus Torvalds	# MCE code calls memory_failure():
736d949f36fSLinus Torvalds	depends on X86_MCE
737d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
738d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
739d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
740d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
741d949f36fSLinus Torvalds
74283125a3aSAlessandro Rubiniconfig STA2X11
74383125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
74483125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
74583125a3aSAlessandro Rubini	select SWIOTLB
74683125a3aSAlessandro Rubini	select MFD_STA2X11
7470145071bSLinus Walleij	select GPIOLIB
748a7f7f624SMasahiro Yamada	help
74983125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
75083125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
75183125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
75283125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
75383125a3aSAlessandro Rubini	  standard PC machines.
75483125a3aSAlessandro Rubini
75582148d1dSShérabconfig X86_32_IRIS
75682148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75782148d1dSShérab	depends on X86_32
758a7f7f624SMasahiro Yamada	help
75982148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
76082148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
76182148d1dSShérab	  needed to do so, which is what this module does at
76282148d1dSShérab	  kernel shutdown.
76382148d1dSShérab
76482148d1dSShérab	  This is only for Iris machines from EuroBraille.
76582148d1dSShérab
76682148d1dSShérab	  If unused, say N.
76782148d1dSShérab
768ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7693c2362e6SHarvey Harrison	def_bool y
7703c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
771a87d0914SKen Chen	depends on X86
772a7f7f624SMasahiro Yamada	help
773506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
774506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
775506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
776506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
777506f1d07SSam Ravnborg
778506f1d07SSam Ravnborg	  If in doubt, say "Y".
779506f1d07SSam Ravnborg
7806276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7816276a074SBorislav Petkov	bool "Linux guest support"
782a7f7f624SMasahiro Yamada	help
7836276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7846276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7856276a074SBorislav Petkov	  setup.
786506f1d07SSam Ravnborg
7876276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7886276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
789506f1d07SSam Ravnborg
7906276a074SBorislav Petkovif HYPERVISOR_GUEST
791506f1d07SSam Ravnborg
792e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
793e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
794a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
795a7f7f624SMasahiro Yamada	help
796e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
797e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
798e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
799e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
800e61bd94aSEduardo Pereira Habkost
801c00a280aSJuergen Grossconfig PARAVIRT_XXL
802c00a280aSJuergen Gross	bool
803c00a280aSJuergen Gross
8046276a074SBorislav Petkovconfig PARAVIRT_DEBUG
8056276a074SBorislav Petkov	bool "paravirt-ops debugging"
8066276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
807a7f7f624SMasahiro Yamada	help
8086276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8096276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8106276a074SBorislav Petkov
811b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
812b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8136ea30386SKees Cook	depends on PARAVIRT && SMP
814a7f7f624SMasahiro Yamada	help
815b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
816b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
817b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
818b4ecc126SJeremy Fitzhardinge
8194c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8204c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
821b4ecc126SJeremy Fitzhardinge
8224c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
823b4ecc126SJeremy Fitzhardinge
824ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
825ecca2502SZhao Yakui	def_bool n
826ecca2502SZhao Yakui
8276276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8286276a074SBorislav Petkov
8296276a074SBorislav Petkovconfig KVM_GUEST
8306276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8316276a074SBorislav Petkov	depends on PARAVIRT
8326276a074SBorislav Petkov	select PARAVIRT_CLOCK
833a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
834b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8356276a074SBorislav Petkov	default y
836a7f7f624SMasahiro Yamada	help
8376276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8386276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8396276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8406276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8416276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8426276a074SBorislav Petkov
843a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
844a1c4423bSMarcelo Tosatti	def_bool n
845a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
846a1c4423bSMarcelo Tosatti	help
847a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
848a1c4423bSMarcelo Tosatti
8497733607fSMaran Wilsonconfig PVH
8507733607fSMaran Wilson	bool "Support for running PVH guests"
851a7f7f624SMasahiro Yamada	help
8527733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8537733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8547733607fSMaran Wilson
8556276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8566276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8576276a074SBorislav Petkov	depends on PARAVIRT
858a7f7f624SMasahiro Yamada	help
8596276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8606276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8616276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8626276a074SBorislav Petkov	  that, there can be a small performance impact.
8636276a074SBorislav Petkov
8646276a074SBorislav Petkov	  If in doubt, say N here.
8656276a074SBorislav Petkov
8667af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8677af192c9SGerd Hoffmann	bool
8687af192c9SGerd Hoffmann
8694a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8704a362601SJan Kiszka	bool "Jailhouse non-root cell support"
871abde587bSArnd Bergmann	depends on X86_64 && PCI
87287e65d05SJan Kiszka	select X86_PM_TIMER
873a7f7f624SMasahiro Yamada	help
8744a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8754a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8764a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8774a362601SJan Kiszka
878ec7972c9SZhao Yakuiconfig ACRN_GUEST
879ec7972c9SZhao Yakui	bool "ACRN Guest support"
880ec7972c9SZhao Yakui	depends on X86_64
881498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
882ec7972c9SZhao Yakui	help
883ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
884ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
885ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
886ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
887ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
888ec7972c9SZhao Yakui
88959bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
89059bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
89159bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
89259bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
89341394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
894968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
89577a512e3SSean Christopherson	select X86_MCE
89659bd54a8SKuppuswamy Sathyanarayanan	help
89759bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
89859bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
89959bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
90059bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
90159bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
90259bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
90359bd54a8SKuppuswamy Sathyanarayanan
9046276a074SBorislav Petkovendif # HYPERVISOR_GUEST
90597349135SJeremy Fitzhardinge
906506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
907506f1d07SSam Ravnborg
908506f1d07SSam Ravnborgconfig HPET_TIMER
9093c2362e6SHarvey Harrison	def_bool X86_64
910506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
911a7f7f624SMasahiro Yamada	help
912506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
913506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
914506f1d07SSam Ravnborg	  present.
915506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
916506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
917506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9184e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9194e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
920506f1d07SSam Ravnborg
921506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
922506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
923506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
924506f1d07SSam Ravnborg
925506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
926506f1d07SSam Ravnborg
927506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9283c2362e6SHarvey Harrison	def_bool y
9293228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
930506f1d07SSam Ravnborg
9316a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
932506f1d07SSam Ravnborg# The code disables itself when not needed.
9337ae9392cSThomas Petazzoniconfig DMI
9347ae9392cSThomas Petazzoni	default y
935cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9366a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
937a7f7f624SMasahiro Yamada	help
9387ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9397ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9407ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9417ae9392cSThomas Petazzoni	  BIOS code.
9427ae9392cSThomas Petazzoni
943506f1d07SSam Ravnborgconfig GART_IOMMU
94438901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9452f9237d4SChristoph Hellwig	select DMA_OPS
946a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
947506f1d07SSam Ravnborg	select SWIOTLB
94823ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
949a7f7f624SMasahiro Yamada	help
950ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
951ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
952ced3c42cSIngo Molnar
953ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
954ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
955ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
956ced3c42cSIngo Molnar
957ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
958ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
959ced3c42cSIngo Molnar
960ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
961ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
962ced3c42cSIngo Molnar	  32-bit limited device.
963ced3c42cSIngo Molnar
964ced3c42cSIngo Molnar	  If unsure, say Y.
965506f1d07SSam Ravnborg
9668b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9678b766b0fSMichal Suchanek	bool
9688b766b0fSMichal Suchanek	help
9698b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9708b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9718b766b0fSMichal Suchanek
9721184dc2fSMike Travisconfig MAXSMP
973ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9746ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
97536f5101aSMike Travis	select CPUMASK_OFFSTACK
976a7f7f624SMasahiro Yamada	help
977ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9781184dc2fSMike Travis	  If unsure, say N.
979506f1d07SSam Ravnborg
980aec6487eSIngo Molnar#
981aec6487eSIngo Molnar# The maximum number of CPUs supported:
982aec6487eSIngo Molnar#
983aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
984aec6487eSIngo Molnar# and which can be configured interactively in the
985aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
986aec6487eSIngo Molnar#
987aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
988aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
989aec6487eSIngo Molnar#
990aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
991aec6487eSIngo Molnar#   interactive configuration. )
992aec6487eSIngo Molnar#
993a0d0bb4dSRandy Dunlap
994aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
995a0d0bb4dSRandy Dunlap	int
996aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
997a0d0bb4dSRandy Dunlap	default    1 if !SMP
998a0d0bb4dSRandy Dunlap	default    2
999a0d0bb4dSRandy Dunlap
1000aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1001a0d0bb4dSRandy Dunlap	int
1002a0d0bb4dSRandy Dunlap	depends on X86_32
1003aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
1004aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
1005a0d0bb4dSRandy Dunlap	default    1 if !SMP
1006a0d0bb4dSRandy Dunlap
1007aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1008a0d0bb4dSRandy Dunlap	int
1009a0d0bb4dSRandy Dunlap	depends on X86_64
10101edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10111edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1012a0d0bb4dSRandy Dunlap	default    1 if !SMP
1013aec6487eSIngo Molnar
1014aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1015aec6487eSIngo Molnar	int
1016aec6487eSIngo Molnar	depends on X86_32
1017aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1018aec6487eSIngo Molnar	default    8 if  SMP
1019aec6487eSIngo Molnar	default    1 if !SMP
1020aec6487eSIngo Molnar
1021aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1022aec6487eSIngo Molnar	int
1023aec6487eSIngo Molnar	depends on X86_64
1024a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1025a0d0bb4dSRandy Dunlap	default   64 if  SMP
1026aec6487eSIngo Molnar	default    1 if !SMP
1027a0d0bb4dSRandy Dunlap
1028506f1d07SSam Ravnborgconfig NR_CPUS
102936f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1030aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1031aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1032a7f7f624SMasahiro Yamada	help
1033506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1034bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1035cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1036506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1037506f1d07SSam Ravnborg
1038aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1039aec6487eSIngo Molnar	  to the kernel image.
1040506f1d07SSam Ravnborg
104166558b73STim Chenconfig SCHED_CLUSTER
104266558b73STim Chen	bool "Cluster scheduler support"
104366558b73STim Chen	depends on SMP
104466558b73STim Chen	default y
104566558b73STim Chen	help
104666558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
104766558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
104866558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
104966558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
105066558b73STim Chen	  busses.
105166558b73STim Chen
1052506f1d07SSam Ravnborgconfig SCHED_SMT
1053dbe73364SThomas Gleixner	def_bool y if SMP
1054506f1d07SSam Ravnborg
1055506f1d07SSam Ravnborgconfig SCHED_MC
10563c2362e6SHarvey Harrison	def_bool y
10573c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1058c8e56d20SBorislav Petkov	depends on SMP
1059a7f7f624SMasahiro Yamada	help
1060506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1061506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1062506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1063506f1d07SSam Ravnborg
1064de966cf4STim Chenconfig SCHED_MC_PRIO
1065de966cf4STim Chen	bool "CPU core priorities scheduler support"
10660a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10670a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10680a21fc12SIngo Molnar	select CPU_FREQ
1069de966cf4STim Chen	default y
1070a7f7f624SMasahiro Yamada	help
1071de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1072de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1073de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1074de966cf4STim Chen	  single threaded workloads) than others.
1075de966cf4STim Chen
1076de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1077de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1078de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1079de966cf4STim Chen	  overall system performance can be achieved.
1080de966cf4STim Chen
1081de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1082de966cf4STim Chen
1083de966cf4STim Chen	  If unsure say Y here.
10845e76b2abSTim Chen
108530b8b006SThomas Gleixnerconfig UP_LATE_INIT
108630b8b006SThomas Gleixner	def_bool y
1087ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
108830b8b006SThomas Gleixner
1089506f1d07SSam Ravnborgconfig X86_UP_APIC
109050849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
109150849eefSJan Beulich	default PCI_MSI
109238a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1093a7f7f624SMasahiro Yamada	help
1094506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1095506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1096506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1097506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1098506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1099506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1100506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1101506f1d07SSam Ravnborg	  lockups.
1102506f1d07SSam Ravnborg
1103506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1104506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1105506f1d07SSam Ravnborg	depends on X86_UP_APIC
1106a7f7f624SMasahiro Yamada	help
1107506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1108506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1109506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1110506f1d07SSam Ravnborg
1111506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1112506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1113506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1114506f1d07SSam Ravnborg
1115506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11163c2362e6SHarvey Harrison	def_bool y
11170dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1118b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
111952f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1120506f1d07SSam Ravnborg
1121506f1d07SSam Ravnborgconfig X86_IO_APIC
1122b1da1e71SJan Beulich	def_bool y
1123b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1124506f1d07SSam Ravnborg
112541b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
112641b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
112741b9eb26SStefan Assmann	depends on X86_IO_APIC
1128a7f7f624SMasahiro Yamada	help
112941b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
113041b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
113141b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
113241b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
113341b9eb26SStefan Assmann
113441b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
113541b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
113641b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
113741b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
113841b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
113941b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
114041b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
114141b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
114241b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
114341b9eb26SStefan Assmann	  down (vital) interrupt lines.
114441b9eb26SStefan Assmann
114541b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
114641b9eb26SStefan Assmann	  increased on these systems.
114741b9eb26SStefan Assmann
1148506f1d07SSam Ravnborgconfig X86_MCE
1149bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1150648ed940SChen, Gong	select GENERIC_ALLOCATOR
1151e57dbaf7SBorislav Petkov	default y
1152a7f7f624SMasahiro Yamada	help
1153bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1154bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1155506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1156bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11574efc0670SAndi Kleen
11585de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11595de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11605de97c9fSTony Luck	depends on X86_MCE
1161a7f7f624SMasahiro Yamada	help
11625de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11635de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11645de97c9fSTony Luck	  rasdaemon solution.
11655de97c9fSTony Luck
1166506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11673c2362e6SHarvey Harrison	def_bool y
11683c2362e6SHarvey Harrison	prompt "Intel MCE features"
1169c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1170a7f7f624SMasahiro Yamada	help
1171506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1172506f1d07SSam Ravnborg	  the thermal monitor.
1173506f1d07SSam Ravnborg
1174506f1d07SSam Ravnborgconfig X86_MCE_AMD
11753c2362e6SHarvey Harrison	def_bool y
11763c2362e6SHarvey Harrison	prompt "AMD MCE features"
1177f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1178a7f7f624SMasahiro Yamada	help
1179506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1180506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1181506f1d07SSam Ravnborg
11824efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11836fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1184c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1185a7f7f624SMasahiro Yamada	help
11864efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11875065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11884efc0670SAndi Kleen	  line.
11894efc0670SAndi Kleen
1190b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1191b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11926fc108a0SJan Beulich	def_bool y
1193b2762686SAndi Kleen
1194ea149b36SAndi Kleenconfig X86_MCE_INJECT
1195bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1196ea149b36SAndi Kleen	tristate "Machine check injector support"
1197a7f7f624SMasahiro Yamada	help
1198ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1199ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1200ea149b36SAndi Kleen	  QA it is safe to say n.
1201ea149b36SAndi Kleen
120207dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1203e633c65aSKan Liang
12045aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
12051e642812SIngo Molnar	bool "Legacy VM86 support"
1206506f1d07SSam Ravnborg	depends on X86_32
1207a7f7f624SMasahiro Yamada	help
12085aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12095aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12105aef51c3SAndy Lutomirski
12115aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12125aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12135aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12145aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12155aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12161e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12171e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12181e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12191e642812SIngo Molnar	  enable this option.
12205aef51c3SAndy Lutomirski
12211e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12221e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12231e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12241e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12255aef51c3SAndy Lutomirski
12261e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12271e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12285aef51c3SAndy Lutomirski
12291e642812SIngo Molnar	  If unsure, say N here.
12305aef51c3SAndy Lutomirski
12315aef51c3SAndy Lutomirskiconfig VM86
12325aef51c3SAndy Lutomirski	bool
12335aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
123434273f41SH. Peter Anvin
123534273f41SH. Peter Anvinconfig X86_16BIT
123634273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
123734273f41SH. Peter Anvin	default y
1238a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1239a7f7f624SMasahiro Yamada	help
124034273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
124134273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
124234273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
124334273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
124434273f41SH. Peter Anvin
124534273f41SH. Peter Anvinconfig X86_ESPFIX32
124634273f41SH. Peter Anvin	def_bool y
124734273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1248506f1d07SSam Ravnborg
1249197725deSH. Peter Anvinconfig X86_ESPFIX64
1250197725deSH. Peter Anvin	def_bool y
125134273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1252506f1d07SSam Ravnborg
12531ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12541ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12551ad83c85SAndy Lutomirski	default y
12561ad83c85SAndy Lutomirski	depends on X86_64
1257a7f7f624SMasahiro Yamada	help
12581ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12591ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12601ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12611ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12621ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12631ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12641ad83c85SAndy Lutomirski
12651ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12661ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12671ad83c85SAndy Lutomirski
12681ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12691ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12701ad83c85SAndy Lutomirski
1271111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1272111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1273a24ca997SThomas Gleixner	default y
1274a7f7f624SMasahiro Yamada	help
1275111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1276111e7b15SThomas Gleixner	  for legacy applications.
1277111e7b15SThomas Gleixner
1278c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1279c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1280c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1281c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1282c8137aceSThomas Gleixner	  modules.
1283c8137aceSThomas Gleixner
1284c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1285c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1286a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1287a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1288c8137aceSThomas Gleixner
1289506f1d07SSam Ravnborgconfig TOSHIBA
1290506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1291506f1d07SSam Ravnborg	depends on X86_32
1292a7f7f624SMasahiro Yamada	help
1293506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1294506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1295506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1296506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1297506f1d07SSam Ravnborg
1298506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1299506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1300506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1301506f1d07SSam Ravnborg
1302506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1303506f1d07SSam Ravnborg	  Say N otherwise.
1304506f1d07SSam Ravnborg
1305506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13069ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13079ba16087SJan Beulich	depends on X86_32
1308a7f7f624SMasahiro Yamada	help
1309506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1310506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1311506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1312506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1313506f1d07SSam Ravnborg	  system.
1314506f1d07SSam Ravnborg
1315506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13165e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1317506f1d07SSam Ravnborg
1318506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1319506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1320506f1d07SSam Ravnborg	  Say N otherwise.
1321506f1d07SSam Ravnborg
1322506f1d07SSam Ravnborgconfig MICROCODE
13239a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13249a2bc335SBorislav Petkov	default y
132580030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1326a7f7f624SMasahiro Yamada	help
1327506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13285f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13295f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13305f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13315f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13325f9c01aaSBorislav Petkov	  the Linux kernel.
1333506f1d07SSam Ravnborg
13345f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1335cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13365f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13375f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1338506f1d07SSam Ravnborg
1339c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1340c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1341c508c46eSBenjamin Gilbert	  config option.
1342506f1d07SSam Ravnborg
13438d86f390SPeter Orubaconfig MICROCODE_INTEL
1344e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13459c55d99eSBorislav Petkov	depends on CPU_SUP_INTEL && MICROCODE
13468d86f390SPeter Oruba	default MICROCODE
1347a7f7f624SMasahiro Yamada	help
13488d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13498d86f390SPeter Oruba	  processors.
13508d86f390SPeter Oruba
1351b8989db9SAlan	  For the current Intel microcode data package go to
1352b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1353b8989db9SAlan	  'Linux Processor Microcode Data File'.
13548d86f390SPeter Oruba
135580cc9f10SPeter Orubaconfig MICROCODE_AMD
1356e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
13579c55d99eSBorislav Petkov	depends on CPU_SUP_AMD && MICROCODE
1358a7f7f624SMasahiro Yamada	help
135980cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
136080cc9f10SPeter Oruba	  processors will be enabled.
136180cc9f10SPeter Oruba
1362a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1363a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1364c02f48e0SBorislav Petkov	default n
1365506f1d07SSam Ravnborg	depends on MICROCODE
1366a7f7f624SMasahiro Yamada	help
1367a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1368a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1369a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1370a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
1371a77a94f8SBorislav Petkov	  use this at your own risk. Late loading taints the kernel too.
1372506f1d07SSam Ravnborg
1373506f1d07SSam Ravnborgconfig X86_MSR
1374506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1375a7f7f624SMasahiro Yamada	help
1376506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1377506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1378506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1379506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1380506f1d07SSam Ravnborg	  systems.
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborgconfig X86_CPUID
1383506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1384a7f7f624SMasahiro Yamada	help
1385506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1386506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1387506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1388506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborgchoice
1391506f1d07SSam Ravnborg	prompt "High Memory Support"
13926fc108a0SJan Beulich	default HIGHMEM4G
1393506f1d07SSam Ravnborg	depends on X86_32
1394506f1d07SSam Ravnborg
1395506f1d07SSam Ravnborgconfig NOHIGHMEM
1396506f1d07SSam Ravnborg	bool "off"
1397a7f7f624SMasahiro Yamada	help
1398506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1399506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1400506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1401506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1402506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1403506f1d07SSam Ravnborg	  "high memory".
1404506f1d07SSam Ravnborg
1405506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1406506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1407506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1408506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1409506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1410506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1411506f1d07SSam Ravnborg	  possible.
1412506f1d07SSam Ravnborg
1413506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1414506f1d07SSam Ravnborg	  answer "4GB" here.
1415506f1d07SSam Ravnborg
1416506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1417506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1418506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1419506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1420506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1421506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1424506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1425506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1426506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1427506f1d07SSam Ravnborg	  kernel at boot time.)
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborg	  If unsure, say "off".
1430506f1d07SSam Ravnborg
1431506f1d07SSam Ravnborgconfig HIGHMEM4G
1432506f1d07SSam Ravnborg	bool "4GB"
1433a7f7f624SMasahiro Yamada	help
1434506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1435506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1436506f1d07SSam Ravnborg
1437506f1d07SSam Ravnborgconfig HIGHMEM64G
1438506f1d07SSam Ravnborg	bool "64GB"
1439225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1440506f1d07SSam Ravnborg	select X86_PAE
1441a7f7f624SMasahiro Yamada	help
1442506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1443506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1444506f1d07SSam Ravnborg
1445506f1d07SSam Ravnborgendchoice
1446506f1d07SSam Ravnborg
1447506f1d07SSam Ravnborgchoice
14486a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1449506f1d07SSam Ravnborg	default VMSPLIT_3G
1450506f1d07SSam Ravnborg	depends on X86_32
1451a7f7f624SMasahiro Yamada	help
1452506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1453506f1d07SSam Ravnborg
1454506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1455506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1456506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1457506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1458506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1459506f1d07SSam Ravnborg	  available to user programs, making the address space there
1460506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1461506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1462506f1d07SSam Ravnborg	  kernel modules.
1463506f1d07SSam Ravnborg
1464506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1465506f1d07SSam Ravnborg	  option alone!
1466506f1d07SSam Ravnborg
1467506f1d07SSam Ravnborg	config VMSPLIT_3G
1468506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1469506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1470506f1d07SSam Ravnborg		depends on !X86_PAE
1471506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1472506f1d07SSam Ravnborg	config VMSPLIT_2G
1473506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1474506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1475506f1d07SSam Ravnborg		depends on !X86_PAE
1476506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1477506f1d07SSam Ravnborg	config VMSPLIT_1G
1478506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1479506f1d07SSam Ravnborgendchoice
1480506f1d07SSam Ravnborg
1481506f1d07SSam Ravnborgconfig PAGE_OFFSET
1482506f1d07SSam Ravnborg	hex
1483506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1484506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1485506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1486506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1487506f1d07SSam Ravnborg	default 0xC0000000
1488506f1d07SSam Ravnborg	depends on X86_32
1489506f1d07SSam Ravnborg
1490506f1d07SSam Ravnborgconfig HIGHMEM
14913c2362e6SHarvey Harrison	def_bool y
1492506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1493506f1d07SSam Ravnborg
1494506f1d07SSam Ravnborgconfig X86_PAE
14959ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1496506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1497d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14989d99c712SChristian Melki	select SWIOTLB
1499a7f7f624SMasahiro Yamada	help
1500506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1501506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1502506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1503506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1504506f1d07SSam Ravnborg
150577ef56e4SKirill A. Shutemovconfig X86_5LEVEL
150677ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
150718ec1eafSKirill A. Shutemov	default y
1508eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1509162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
151077ef56e4SKirill A. Shutemov	depends on X86_64
1511a7f7f624SMasahiro Yamada	help
151277ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
151377ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
151477ef56e4SKirill A. Shutemov	  physical address space.
151577ef56e4SKirill A. Shutemov
151677ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
151777ef56e4SKirill A. Shutemov
15186657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15196657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
152077ef56e4SKirill A. Shutemov
1521cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
152277ef56e4SKirill A. Shutemov	  information.
152377ef56e4SKirill A. Shutemov
152477ef56e4SKirill A. Shutemov	  Say N if unsure.
152577ef56e4SKirill A. Shutemov
152610971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1527e5008abeSLuis R. Rodriguez	def_bool y
15282e1da13fSVlastimil Babka	depends on X86_64
1529a7f7f624SMasahiro Yamada	help
153010971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
153110971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
153210971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
153310971ab2SIngo Molnar	  that we have them enabled.
15349e899816SNick Piggin
15355c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15365c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15375c280cf6SThomas Gleixner	depends on DEBUG_FS
1538a7f7f624SMasahiro Yamada	help
1539b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1540a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15415c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15425c280cf6SThomas Gleixner
154320f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
154420f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
154520f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
154620f07a04SKirill A. Shutemov	def_bool n
154720f07a04SKirill A. Shutemov
15487744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15497744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15507744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
155182fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1552ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1553597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1554aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
155520f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1556a7f7f624SMasahiro Yamada	help
15577744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15587744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15597744ccdbSTom Lendacky	  Encryption (SME).
15607744ccdbSTom Lendacky
15617744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15627744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15637744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1564a7f7f624SMasahiro Yamada	help
15657744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15667744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15677744ccdbSTom Lendacky
15687744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15697744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15707744ccdbSTom Lendacky
15717744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15727744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15737744ccdbSTom Lendacky
1574506f1d07SSam Ravnborg# Common NUMA Features
1575506f1d07SSam Ravnborgconfig NUMA
1576e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1577506f1d07SSam Ravnborg	depends on SMP
1578b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1579b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15807ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1581a7f7f624SMasahiro Yamada	help
1582e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1583fd51b2d7SKOSAKI Motohiro
1584506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1585506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1586506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1587506f1d07SSam Ravnborg
1588c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1589fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1590fd51b2d7SKOSAKI Motohiro
1591b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15927cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1593fd51b2d7SKOSAKI Motohiro
1594fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1595506f1d07SSam Ravnborg
1596eec1d4faSHans Rosenfeldconfig AMD_NUMA
15973c2362e6SHarvey Harrison	def_bool y
15983c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15995da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1600a7f7f624SMasahiro Yamada	help
1601eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1602eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1603eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1604eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1605eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1606506f1d07SSam Ravnborg
1607506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
16083c2362e6SHarvey Harrison	def_bool y
16093c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1610506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1611506f1d07SSam Ravnborg	select ACPI_NUMA
1612a7f7f624SMasahiro Yamada	help
1613506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1614506f1d07SSam Ravnborg
1615506f1d07SSam Ravnborgconfig NUMA_EMU
1616506f1d07SSam Ravnborg	bool "NUMA emulation"
16171b7e03efSTejun Heo	depends on NUMA
1618a7f7f624SMasahiro Yamada	help
1619506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1620506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1621506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1622506f1d07SSam Ravnborg
1623506f1d07SSam Ravnborgconfig NODES_SHIFT
1624d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
162551591e31SDavid Rientjes	range 1 10
162651591e31SDavid Rientjes	default "10" if MAXSMP
1627506f1d07SSam Ravnborg	default "6" if X86_64
1628506f1d07SSam Ravnborg	default "3"
1629a9ee6cf5SMike Rapoport	depends on NUMA
1630a7f7f624SMasahiro Yamada	help
16311184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1632692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1633506f1d07SSam Ravnborg
1634506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1635506f1d07SSam Ravnborg	def_bool y
16363b16651fSTejun Heo	depends on X86_32 && !NUMA
1637506f1d07SSam Ravnborg
1638506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1639506f1d07SSam Ravnborg	def_bool y
16406ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1641506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1642506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1643506f1d07SSam Ravnborg
16443b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16456ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16463b16651fSTejun Heo
1647506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1648506f1d07SSam Ravnborg	def_bool y
16494eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1650506f1d07SSam Ravnborg
1651506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1652a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16535c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1654a0842b70SToshi Kani	help
1655a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1656cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1657a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1658506f1d07SSam Ravnborg
16593b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16603b16651fSTejun Heo	def_bool y
16613b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16623b16651fSTejun Heo
1663a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1664a29815a3SAvi Kivity	hex
1665a29815a3SAvi Kivity	default 0 if X86_32
1666a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1667a29815a3SAvi Kivity
16687a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16697a67832cSDan Williams	bool
16707a67832cSDan Williams
1671ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16727a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16739f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16749f53f9faSDan Williams	depends on BLK_DEV
16757a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16767b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16779f53f9faSDan Williams	select LIBNVDIMM
1678ec776ef6SChristoph Hellwig	help
1679ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1680ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1681ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1682ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1683ec776ef6SChristoph Hellwig
1684ec776ef6SChristoph Hellwig	  Say Y if unsure.
1685ec776ef6SChristoph Hellwig
1686506f1d07SSam Ravnborgconfig HIGHPTE
1687506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16886fc108a0SJan Beulich	depends on HIGHMEM
1689a7f7f624SMasahiro Yamada	help
1690506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1691506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1692506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1693506f1d07SSam Ravnborg	  entries in high memory.
1694506f1d07SSam Ravnborg
16959f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16969f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1697a7f7f624SMasahiro Yamada	help
16989f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16999f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
17009f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
17019f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
17029f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
17039f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
17049f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
17058c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
17069f077871SJeremy Fitzhardinge
17079f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17089f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17099f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17109f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17119f077871SJeremy Fitzhardinge
17129f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17139f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17149f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17159f077871SJeremy Fitzhardinge	  memory.
17169f077871SJeremy Fitzhardinge
1717c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1718c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1719c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1720c885df50SJeremy Fitzhardinge	default y
1721a7f7f624SMasahiro Yamada	help
1722c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1723c885df50SJeremy Fitzhardinge	  on or off.
1724c885df50SJeremy Fitzhardinge
1725506f1d07SSam Ravnborgconfig MATH_EMULATION
1726506f1d07SSam Ravnborg	bool
1727a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
172887d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1729a7f7f624SMasahiro Yamada	help
1730506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1731506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1732506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1733506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1734506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1735506f1d07SSam Ravnborg	  coprocessor or this emulation.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1738506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1739506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1740506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1741506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1742506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1743506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1744506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1745506f1d07SSam Ravnborg
1746506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1747506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1748506f1d07SSam Ravnborg
1749506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1750506f1d07SSam Ravnborg	  kernel, it won't hurt.
1751506f1d07SSam Ravnborg
1752506f1d07SSam Ravnborgconfig MTRR
17536fc108a0SJan Beulich	def_bool y
17546a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1755a7f7f624SMasahiro Yamada	help
1756506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1757506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1758506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1759506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1760506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1761506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1762506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1763506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1764506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1765506f1d07SSam Ravnborg
1766506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1767506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1768506f1d07SSam Ravnborg	  as well:
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1771506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1772506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1773506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1774506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1775506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1776506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1777506f1d07SSam Ravnborg
1778506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1779506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1780506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1781506f1d07SSam Ravnborg
1782506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1783506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1784506f1d07SSam Ravnborg
1785cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1786506f1d07SSam Ravnborg
178795ffa243SYinghai Luconfig MTRR_SANITIZER
17882ffb3501SYinghai Lu	def_bool y
178995ffa243SYinghai Lu	prompt "MTRR cleanup support"
179095ffa243SYinghai Lu	depends on MTRR
1791a7f7f624SMasahiro Yamada	help
1792aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1793aba3728cSThomas Gleixner	  add writeback entries.
179495ffa243SYinghai Lu
1795aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1796692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1797aba3728cSThomas Gleixner	  mtrr_chunk_size.
179895ffa243SYinghai Lu
17992ffb3501SYinghai Lu	  If unsure, say Y.
180095ffa243SYinghai Lu
180195ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1802f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1803f5098d62SYinghai Lu	range 0 1
1804f5098d62SYinghai Lu	default "0"
180595ffa243SYinghai Lu	depends on MTRR_SANITIZER
1806a7f7f624SMasahiro Yamada	help
1807f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180895ffa243SYinghai Lu
180912031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
181012031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
181112031a62SYinghai Lu	range 0 7
181212031a62SYinghai Lu	default "1"
181312031a62SYinghai Lu	depends on MTRR_SANITIZER
1814a7f7f624SMasahiro Yamada	help
181512031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1816aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
181712031a62SYinghai Lu
18182e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18196fc108a0SJan Beulich	def_bool y
18206a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18212a8a2719SIngo Molnar	depends on MTRR
1822a7f7f624SMasahiro Yamada	help
18232e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1824042b78e4SVenki Pallipadi
18252e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18262e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18272e5d9c85Svenkatesh.pallipadi@intel.com
18282e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1829042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18302e5d9c85Svenkatesh.pallipadi@intel.com
18312e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18322e5d9c85Svenkatesh.pallipadi@intel.com
183346cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
183446cf98cdSVenkatesh Pallipadi	def_bool y
183546cf98cdSVenkatesh Pallipadi	depends on X86_PAT
183646cf98cdSVenkatesh Pallipadi
1837628c6246SH. Peter Anvinconfig ARCH_RANDOM
1838628c6246SH. Peter Anvin	def_bool y
1839628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1840a7f7f624SMasahiro Yamada	help
1841628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1842628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1843628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1844628c6246SH. Peter Anvin	  secure hardware random number generator.
1845628c6246SH. Peter Anvin
1846b971880fSBabu Mogerconfig X86_UMIP
1847796ebc81SRicardo Neri	def_bool y
1848b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1849a7f7f624SMasahiro Yamada	help
1850b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1851b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1852b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1853b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1854b971880fSBabu Moger	  information about the hardware state.
1855796ebc81SRicardo Neri
1856796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1857796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1858796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1859796ebc81SRicardo Neri	  results are dummy.
1860aa35f896SRicardo Neri
1861156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1862156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1863156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1864156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1865262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1866262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1867156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1868262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1869156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1870156ff4a5SPeter Zijlstra
1871156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1872156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
1873156ff4a5SPeter Zijlstra	bool
187403f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1875f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1876f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
187703f16cd0SJosh Poimboeuf	select OBJTOOL
1878156ff4a5SPeter Zijlstra	help
1879156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1880156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1881156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1882156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1883156ff4a5SPeter Zijlstra	  code with them to make this happen.
1884156ff4a5SPeter Zijlstra
1885ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18864cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1887ed53a0d9SPeter Zijlstra
1888ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1889ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1890ed53a0d9SPeter Zijlstra	  kernel image.
1891ed53a0d9SPeter Zijlstra
189235e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
189338f3e775SBabu Moger	prompt "Memory Protection Keys"
189435e97790SDave Hansen	def_bool y
1895284244a9SDave Hansen	# Note: only available in 64-bit mode
189638f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
189752c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
189852c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1899a7f7f624SMasahiro Yamada	help
1900284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1901284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1902284244a9SDave Hansen	  page tables when an application changes protection domains.
1903284244a9SDave Hansen
19041eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1905284244a9SDave Hansen
1906284244a9SDave Hansen	  If unsure, say y.
190735e97790SDave Hansen
1908db616173SMichal Hockochoice
1909db616173SMichal Hocko	prompt "TSX enable mode"
1910db616173SMichal Hocko	depends on CPU_SUP_INTEL
1911db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1912db616173SMichal Hocko	help
1913db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1914db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1915db616173SMichal Hocko	  can lead to a noticeable performance boost.
1916db616173SMichal Hocko
1917db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1918db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1919db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1920db616173SMichal Hocko
1921db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1922db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1923db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1924db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1925db616173SMichal Hocko	  for the particular machine.
1926db616173SMichal Hocko
1927db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1928db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1929db616173SMichal Hocko	  details.
1930db616173SMichal Hocko
1931db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1932db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1933db616173SMichal Hocko	  relevant.
1934db616173SMichal Hocko
1935db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1936db616173SMichal Hocko	bool "off"
1937db616173SMichal Hocko	help
1938db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1939db616173SMichal Hocko
1940db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1941db616173SMichal Hocko	bool "on"
1942db616173SMichal Hocko	help
1943db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1944db616173SMichal Hocko	  line parameter.
1945db616173SMichal Hocko
1946db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1947db616173SMichal Hocko	bool "auto"
1948db616173SMichal Hocko	help
1949db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1950db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1951db616173SMichal Hockoendchoice
1952db616173SMichal Hocko
1953e7e05452SSean Christophersonconfig X86_SGX
1954e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1955e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1956e7e05452SSean Christopherson	depends on CRYPTO=y
1957e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1958e7e05452SSean Christopherson	select SRCU
1959e7e05452SSean Christopherson	select MMU_NOTIFIER
1960901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
196140e0e784STony Luck	select XARRAY_MULTI
1962e7e05452SSean Christopherson	help
1963e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1964e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1965e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1966e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1967e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1968e7e05452SSean Christopherson	  hardware.
1969e7e05452SSean Christopherson
1970e7e05452SSean Christopherson	  If unsure, say N.
1971e7e05452SSean Christopherson
1972506f1d07SSam Ravnborgconfig EFI
19739ba16087SJan Beulich	bool "EFI runtime service support"
19745b83683fSHuang, Ying	depends on ACPI
1975f6ce5002SSergey Vlasov	select UCS2_STRING
1976022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19771ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1978a7f7f624SMasahiro Yamada	help
19798b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1980506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1981506f1d07SSam Ravnborg
19828b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19838b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19848b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19858b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19868b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19878b2cb7a8SHuang, Ying	  platforms.
1988506f1d07SSam Ravnborg
1989291f3632SMatt Flemingconfig EFI_STUB
1990291f3632SMatt Fleming	bool "EFI stub support"
1991c6dbd3e5SPeter Zijlstra	depends on EFI
19928f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19937b2a583aSMatt Fleming	select RELOCATABLE
1994a7f7f624SMasahiro Yamada	help
1995291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1996291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1997291f3632SMatt Fleming
19984f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19990c759662SMatt Fleming
20007d453eeeSMatt Flemingconfig EFI_MIXED
20017d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20027d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
2003a7f7f624SMasahiro Yamada	help
20047d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
20057d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
20067d453eeeSMatt Fleming	  mode.
20077d453eeeSMatt Fleming
20087d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
20097d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
20107d453eeeSMatt Fleming	  the EFI handover protocol must be used.
20117d453eeeSMatt Fleming
20127d453eeeSMatt Fleming	  If unsure, say N.
20137d453eeeSMatt Fleming
20148636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2015506f1d07SSam Ravnborg
2016506f1d07SSam Ravnborgconfig KEXEC
2017506f1d07SSam Ravnborg	bool "kexec system call"
20182965faa5SDave Young	select KEXEC_CORE
2019a7f7f624SMasahiro Yamada	help
2020506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2021506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2022506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2023506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2024506f1d07SSam Ravnborg
2025506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2026506f1d07SSam Ravnborg
2027506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2028506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2029bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2030bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2031bf220695SGeert Uytterhoeven	  made.
2032506f1d07SSam Ravnborg
203374ca317cSVivek Goyalconfig KEXEC_FILE
203474ca317cSVivek Goyal	bool "kexec file based system call"
20352965faa5SDave Young	select KEXEC_CORE
203674ca317cSVivek Goyal	select BUILD_BIN2C
203774ca317cSVivek Goyal	depends on X86_64
203874ca317cSVivek Goyal	depends on CRYPTO=y
203974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2040a7f7f624SMasahiro Yamada	help
204174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
204274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
204374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
204474ca317cSVivek Goyal	  accepted by previous system call.
204574ca317cSVivek Goyal
2046b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2047b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2048b799a09fSAKASHI Takahiro
204999d5cadfSJiri Bohacconfig KEXEC_SIG
20508e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
205174ca317cSVivek Goyal	depends on KEXEC_FILE
2052a7f7f624SMasahiro Yamada	help
205399d5cadfSJiri Bohac
205499d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
205599d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
205699d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
205799d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
205899d5cadfSJiri Bohac
205999d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
206099d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
206199d5cadfSJiri Bohac	  loaded in order for this to work.
206299d5cadfSJiri Bohac
206399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
206499d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
206599d5cadfSJiri Bohac	depends on KEXEC_SIG
2066a7f7f624SMasahiro Yamada	help
20678e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2068d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20698e7d8381SVivek Goyal
20708e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20718e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
207299d5cadfSJiri Bohac	depends on KEXEC_SIG
20738e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20748e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2075a7f7f624SMasahiro Yamada	help
20768e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20778e7d8381SVivek Goyal
2078506f1d07SSam Ravnborgconfig CRASH_DUMP
207904b69447SPavel Machek	bool "kernel crash dumps"
2080506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2081a7f7f624SMasahiro Yamada	help
2082506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2083506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2084506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2085506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2086506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2087506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2088506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2089506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2090330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2091506f1d07SSam Ravnborg
20923ab83521SHuang Yingconfig KEXEC_JUMP
20936ea30386SKees Cook	bool "kexec jump"
2094fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2095a7f7f624SMasahiro Yamada	help
209689081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
209789081d17SHuang Ying	  code in physical address mode via KEXEC
20983ab83521SHuang Ying
2099506f1d07SSam Ravnborgconfig PHYSICAL_START
21006a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2101ceefccc9SH. Peter Anvin	default "0x1000000"
2102a7f7f624SMasahiro Yamada	help
2103506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2104506f1d07SSam Ravnborg
2105506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2106506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2107506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2108506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2109506f1d07SSam Ravnborg	  address.
2110506f1d07SSam Ravnborg
2111506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2112506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2113506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2114506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2115506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2116506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2117506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2118506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2119506f1d07SSam Ravnborg
2120ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2121ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2122ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2123ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2124ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2125ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2126ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2127330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2128ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2129506f1d07SSam Ravnborg
2130506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2131506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2132506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2133506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2134506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2135506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2136506f1d07SSam Ravnborg	  line.
2137506f1d07SSam Ravnborg
2138506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2139506f1d07SSam Ravnborg
2140506f1d07SSam Ravnborgconfig RELOCATABLE
214126717808SH. Peter Anvin	bool "Build a relocatable kernel"
214226717808SH. Peter Anvin	default y
2143a7f7f624SMasahiro Yamada	help
2144506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2145506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2146506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2147506f1d07SSam Ravnborg	  but are discarded at runtime.
2148506f1d07SSam Ravnborg
2149506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2150506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2151506f1d07SSam Ravnborg	  kernel.
2152506f1d07SSam Ravnborg
2153506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2154506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21558ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2156506f1d07SSam Ravnborg
21578ab3820fSKees Cookconfig RANDOMIZE_BASE
2158e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21598ab3820fSKees Cook	depends on RELOCATABLE
21606807c846SIngo Molnar	default y
2161a7f7f624SMasahiro Yamada	help
2162e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2163e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2164e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2165e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2166e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2167e8581e3dSBaoquan He	  code internals.
2168e8581e3dSBaoquan He
2169ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2170ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2171ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2172ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2173ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2174ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2175ed9f007eSKees Cook
2176ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2177ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2178ed9f007eSKees Cook	  512MB (8 bits of entropy).
21798ab3820fSKees Cook
2180a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2181e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2182e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2183ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2184ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2185ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2186ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2187ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2188ed9f007eSKees Cook	  limited due to memory layouts.
2189e8581e3dSBaoquan He
21906807c846SIngo Molnar	  If unsure, say Y.
2191da2b6fb9SKees Cook
21928ab3820fSKees Cook# Relocation on x86 needs some additional build support
2193845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2194845adf72SH. Peter Anvin	def_bool y
21958ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2196845adf72SH. Peter Anvin
2197506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2198a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21998ab3820fSKees Cook	default "0x200000"
2200a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2201a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2202a7f7f624SMasahiro Yamada	help
2203506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2204506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2205506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2206506f1d07SSam Ravnborg
2207506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2208506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2209506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2210506f1d07SSam Ravnborg
2211506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2212506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2213506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2214506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2215506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2216506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2217506f1d07SSam Ravnborg	  above alignment restrictions.
2218506f1d07SSam Ravnborg
2219a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2220a0215061SKees Cook	  this value must be a multiple of 0x200000.
2221a0215061SKees Cook
2222506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2223506f1d07SSam Ravnborg
2224eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2225eedb92abSKirill A. Shutemov	bool
2226a7f7f624SMasahiro Yamada	help
2227eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2228eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2229eedb92abSKirill A. Shutemov
22300483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22310483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22320483e1faSThomas Garnier	depends on X86_64
22330483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2234eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22350483e1faSThomas Garnier	default RANDOMIZE_BASE
2236a7f7f624SMasahiro Yamada	help
22370483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22380483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22390483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22400483e1faSThomas Garnier
22410483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22420483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22430483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22440483e1faSThomas Garnier	  addresses for each memory section.
22450483e1faSThomas Garnier
22466807c846SIngo Molnar	  If unsure, say Y.
22470483e1faSThomas Garnier
224890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
224990397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
225090397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
225190397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
225290397a41SThomas Garnier	default "0x0"
225390397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
225490397a41SThomas Garnier	range 0x0 0x40
2255a7f7f624SMasahiro Yamada	help
225690397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
225790397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
225890397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
225990397a41SThomas Garnier	  address randomization.
226090397a41SThomas Garnier
226190397a41SThomas Garnier	  If unsure, leave at the default value.
226290397a41SThomas Garnier
2263506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2264bebd024eSThomas Gleixner	def_bool y
226540b31360SStephen Rothwell	depends on SMP
2266506f1d07SSam Ravnborg
226780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
226880aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22692c922cd0SKees Cook	depends on HOTPLUG_CPU
2270a7f7f624SMasahiro Yamada	help
227180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
227280aa1dffSFenghua Yu
227380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
227480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
227580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
227680aa1dffSFenghua Yu
227780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
227880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
227980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
228080aa1dffSFenghua Yu
228180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
228280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
228380aa1dffSFenghua Yu
228480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
228580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
228680aa1dffSFenghua Yu	  be other CPU0 dependencies.
228780aa1dffSFenghua Yu
228880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
228980aa1dffSFenghua Yu	  you enable this feature.
229080aa1dffSFenghua Yu
229180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
229280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
229380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
229480aa1dffSFenghua Yu
2295a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2296a71c8bc5SFenghua Yu	def_bool n
2297a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22982c922cd0SKees Cook	depends on HOTPLUG_CPU
2299a7f7f624SMasahiro Yamada	help
2300a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2301a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2302a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2303a71c8bc5SFenghua Yu
2304a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2305a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2306a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2307a71c8bc5SFenghua Yu
2308a71c8bc5SFenghua Yu	  If unsure, say N.
2309a71c8bc5SFenghua Yu
2310506f1d07SSam Ravnborgconfig COMPAT_VDSO
2311b0b49f26SAndy Lutomirski	def_bool n
2312b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2313953fee1dSIngo Molnar	depends on COMPAT_32
2314a7f7f624SMasahiro Yamada	help
2315b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2316b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2317b0b49f26SAndy Lutomirski	  indicated in its segment table.
2318e84446deSRandy Dunlap
2319b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2320b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2321b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2322b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2323b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2324506f1d07SSam Ravnborg
2325b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2326b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2327b0b49f26SAndy Lutomirski
2328b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2329b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2330b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2331b0b49f26SAndy Lutomirski
2332b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2333b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2334506f1d07SSam Ravnborg
23353dc33bd3SKees Cookchoice
23363dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23373dc33bd3SKees Cook	depends on X86_64
2338625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23393dc33bd3SKees Cook	help
23403dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23413dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23423dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23433dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23443dc33bd3SKees Cook
23453dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2346bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2347bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2348bf00745eSAndy Lutomirski	  line.
23493dc33bd3SKees Cook
23503dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23513dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23523dc33bd3SKees Cook	  to improve security.
23533dc33bd3SKees Cook
2354bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23553dc33bd3SKees Cook
2356bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2357bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2358bd49e16eSAndy Lutomirski		help
2359bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2360bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2361bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2362bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2363bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2364bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2365bd49e16eSAndy Lutomirski		  buffer.
23663dc33bd3SKees Cook
23673dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23683dc33bd3SKees Cook		bool "None"
23693dc33bd3SKees Cook		help
23703dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23713dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23723dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23733dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23743dc33bd3SKees Cook		  malicious userspace programs can be identified.
23753dc33bd3SKees Cook
23763dc33bd3SKees Cookendchoice
23773dc33bd3SKees Cook
2378516cbf37STim Birdconfig CMDLINE_BOOL
2379516cbf37STim Bird	bool "Built-in kernel command line"
2380a7f7f624SMasahiro Yamada	help
2381516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2382516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2383516cbf37STim Bird	  necessary or convenient to provide some or all of the
2384516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2385516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2386516cbf37STim Bird
2387516cbf37STim Bird	  To compile command line arguments into the kernel,
2388516cbf37STim Bird	  set this option to 'Y', then fill in the
238969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2390516cbf37STim Bird
2391516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2392516cbf37STim Bird	  should leave this option set to 'N'.
2393516cbf37STim Bird
2394516cbf37STim Birdconfig CMDLINE
2395516cbf37STim Bird	string "Built-in kernel command string"
2396516cbf37STim Bird	depends on CMDLINE_BOOL
2397516cbf37STim Bird	default ""
2398a7f7f624SMasahiro Yamada	help
2399516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2400516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2401516cbf37STim Bird	  command line at boot time, it is appended to this string to
2402516cbf37STim Bird	  form the full kernel command line, when the system boots.
2403516cbf37STim Bird
2404516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2405516cbf37STim Bird	  change this behavior.
2406516cbf37STim Bird
2407516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2408516cbf37STim Bird	  by the boot loader) should specify the device for the root
2409516cbf37STim Bird	  file system.
2410516cbf37STim Bird
2411516cbf37STim Birdconfig CMDLINE_OVERRIDE
2412516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2413645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2414a7f7f624SMasahiro Yamada	help
2415516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2416516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2417516cbf37STim Bird
2418516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2419516cbf37STim Bird	  be set to 'N' under normal conditions.
2420516cbf37STim Bird
2421a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2422a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2423a5b9e5a2SAndy Lutomirski	default y
2424a7f7f624SMasahiro Yamada	help
2425a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2426a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2427a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2428a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2429a5b9e5a2SAndy Lutomirski	  threading libraries.
2430a5b9e5a2SAndy Lutomirski
2431a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2432a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2433a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2434a5b9e5a2SAndy Lutomirski
2435a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2436a5b9e5a2SAndy Lutomirski
24373aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24383aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24393aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24403aac3ebeSThomas Gleixner	help
24413aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24423aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24433aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24443aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24453aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24463aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24473aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24483aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24493aac3ebeSThomas Gleixner	  never get a signal delivered.
24503aac3ebeSThomas Gleixner
24513aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24523aac3ebeSThomas Gleixner
2453b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2454b700e7f0SSeth Jennings
2455506f1d07SSam Ravnborgendmenu
2456506f1d07SSam Ravnborg
24573072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24583072e413SMichal Hocko	def_bool y
24595c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24603072e413SMichal Hocko
2461f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2462f91ef222SOscar Salvador	def_bool y
2463f91ef222SOscar Salvador
2464da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2465e279b6c1SSam Ravnborg
2466e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24673c2362e6SHarvey Harrison	def_bool y
246844556530SZhimin Gu	depends on HIBERNATION
2469e279b6c1SSam Ravnborg
2470e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2471e279b6c1SSam Ravnborg
2472e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2473e279b6c1SSam Ravnborg
2474a6b68076SAndi Kleenconfig X86_APM_BOOT
24756fc108a0SJan Beulich	def_bool y
2476282e5aabSPaul Bolle	depends on APM
2477a6b68076SAndi Kleen
2478e279b6c1SSam Ravnborgmenuconfig APM
2479e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2480efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2481a7f7f624SMasahiro Yamada	help
2482e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2483e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2484e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2485e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2486e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2487e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2490e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2491e279b6c1SSam Ravnborg
2492e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2493e279b6c1SSam Ravnborg	  machines with more than one CPU.
2494e279b6c1SSam Ravnborg
2495e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2496151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24972dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2498e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2499e279b6c1SSam Ravnborg
2500e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2501e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2502e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2503e279b6c1SSam Ravnborg
2504e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2505e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2506e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2507e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2508e279b6c1SSam Ravnborg
2509e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2510e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2511e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2512e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2513e279b6c1SSam Ravnborg	  APM in your BIOS).
2514e279b6c1SSam Ravnborg
2515e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2516e279b6c1SSam Ravnborg	  "weird" problems:
2517e279b6c1SSam Ravnborg
2518e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2519e279b6c1SSam Ravnborg	  enabled.
2520e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2521e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2522e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2523e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2524e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2525e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2526e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2527e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2528e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2529e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2530e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2531e279b6c1SSam Ravnborg	  11) exchange RAM chips
2532e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2533e279b6c1SSam Ravnborg
2534e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2535e279b6c1SSam Ravnborg	  module will be called apm.
2536e279b6c1SSam Ravnborg
2537e279b6c1SSam Ravnborgif APM
2538e279b6c1SSam Ravnborg
2539e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2540e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2541a7f7f624SMasahiro Yamada	help
2542e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2543e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2544e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2545e279b6c1SSam Ravnborg
2546e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2547e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2548a7f7f624SMasahiro Yamada	help
2549e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2550e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2551e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2552e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2553e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2554e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2555e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2556e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2557e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2558e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2559e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2560e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2561e279b6c1SSam Ravnborg	  this feature.
2562e279b6c1SSam Ravnborg
2563e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2564dd8af076SLen Brown	depends on CPU_IDLE
2565e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2566a7f7f624SMasahiro Yamada	help
2567e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2568e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2569e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2570e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2571e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2572e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2573e279b6c1SSam Ravnborg	  this option does nothing.)
2574e279b6c1SSam Ravnborg
2575e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2576e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2577a7f7f624SMasahiro Yamada	help
2578e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2579e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2580e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2581e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2582e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2583e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2584e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2585e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2586e279b6c1SSam Ravnborg	  especially if you are using gpm.
2587e279b6c1SSam Ravnborg
2588e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2589e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2590a7f7f624SMasahiro Yamada	help
2591e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2592e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2593e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2594e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2595e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2596e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2597e279b6c1SSam Ravnborg
2598e279b6c1SSam Ravnborgendif # APM
2599e279b6c1SSam Ravnborg
2600bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2601e279b6c1SSam Ravnborg
2602e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2603e279b6c1SSam Ravnborg
260427471fdbSAndy Henroidsource "drivers/idle/Kconfig"
260527471fdbSAndy Henroid
2606e279b6c1SSam Ravnborgendmenu
2607e279b6c1SSam Ravnborg
2608e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2609e279b6c1SSam Ravnborg
2610e279b6c1SSam Ravnborgchoice
2611e279b6c1SSam Ravnborg	prompt "PCI access mode"
2612efefa6f6SIngo Molnar	depends on X86_32 && PCI
2613e279b6c1SSam Ravnborg	default PCI_GOANY
2614a7f7f624SMasahiro Yamada	help
2615e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2616e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2617e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2618e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2619e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2622e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2623e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2624e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2625e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2626e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2627e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2628e279b6c1SSam Ravnborg
2629e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2630e279b6c1SSam Ravnborg	bool "BIOS"
2631e279b6c1SSam Ravnborg
2632e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2633e279b6c1SSam Ravnborg	bool "MMConfig"
2634e279b6c1SSam Ravnborg
2635e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2636e279b6c1SSam Ravnborg	bool "Direct"
2637e279b6c1SSam Ravnborg
26383ef0e1f8SAndres Salomonconfig PCI_GOOLPC
263976fb6570SDaniel Drake	bool "OLPC XO-1"
26403ef0e1f8SAndres Salomon	depends on OLPC
26413ef0e1f8SAndres Salomon
26422bdd1b03SAndres Salomonconfig PCI_GOANY
26432bdd1b03SAndres Salomon	bool "Any"
26442bdd1b03SAndres Salomon
2645e279b6c1SSam Ravnborgendchoice
2646e279b6c1SSam Ravnborg
2647e279b6c1SSam Ravnborgconfig PCI_BIOS
26483c2362e6SHarvey Harrison	def_bool y
2649efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2650e279b6c1SSam Ravnborg
2651e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2652e279b6c1SSam Ravnborgconfig PCI_DIRECT
26533c2362e6SHarvey Harrison	def_bool y
26540aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2655e279b6c1SSam Ravnborg
2656e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2657b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2658b45c9f36SJan Kiszka	default y
26594590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2660b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2661e279b6c1SSam Ravnborg
26623ef0e1f8SAndres Salomonconfig PCI_OLPC
26632bdd1b03SAndres Salomon	def_bool y
26642bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26653ef0e1f8SAndres Salomon
2666b5401a96SAlex Nixonconfig PCI_XEN
2667b5401a96SAlex Nixon	def_bool y
2668b5401a96SAlex Nixon	depends on PCI && XEN
2669b5401a96SAlex Nixon
26708364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26718364e1f8SJan Kiszka	def_bool y
26728364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2673e279b6c1SSam Ravnborg
26743f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26756a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26766ea30386SKees Cook	depends on PCI
26773f6ea84aSIra W. Snyder	help
26783f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26793f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26803f6ea84aSIra W. Snyder	  not have ACPI.
26813f6ea84aSIra W. Snyder
268264a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
268364a5fed6SBjorn Helgaas	  is known to be incomplete.
268464a5fed6SBjorn Helgaas
268564a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
268664a5fed6SBjorn Helgaas
26873a495511SWilliam Breathitt Grayconfig ISA_BUS
268817a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26893a495511SWilliam Breathitt Gray	help
269017a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
269117a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
269217a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
269317a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
269417a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26953a495511SWilliam Breathitt Gray
26963a495511SWilliam Breathitt Gray	  If unsure, say N.
26973a495511SWilliam Breathitt Gray
26981c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2699e279b6c1SSam Ravnborgconfig ISA_DMA_API
27001c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
27011c00f016SDavid Rientjes	default y
27021c00f016SDavid Rientjes	help
27031c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
27041c00f016SDavid Rientjes	  If unsure, say Y.
2705e279b6c1SSam Ravnborg
270651e68d05SLinus Torvaldsif X86_32
270751e68d05SLinus Torvalds
2708e279b6c1SSam Ravnborgconfig ISA
2709e279b6c1SSam Ravnborg	bool "ISA support"
2710a7f7f624SMasahiro Yamada	help
2711e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2712e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2713e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2714e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2715e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2716e279b6c1SSam Ravnborg
2717e279b6c1SSam Ravnborgconfig SCx200
2718e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2719a7f7f624SMasahiro Yamada	help
2720e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2721e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2722e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2723e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2724e279b6c1SSam Ravnborg
2725e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2726e279b6c1SSam Ravnborg
2727e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2728e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2729592913ecSJohn Stultz	depends on SCx200
2730e279b6c1SSam Ravnborg	default y
2731a7f7f624SMasahiro Yamada	help
2732e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2733e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2734e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2735e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2736e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2737e279b6c1SSam Ravnborg
27383ef0e1f8SAndres Salomonconfig OLPC
27393ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
274054008979SThomas Gleixner	depends on !X86_PAE
27413c554946SAndres Salomon	select GPIOLIB
2742dc3119e7SThomas Gleixner	select OF
274345bb1674SDaniel Drake	select OF_PROMTREE
2744b4e51854SGrant Likely	select IRQ_DOMAIN
27450c3d931bSLubomir Rintel	select OLPC_EC
2746a7f7f624SMasahiro Yamada	help
27473ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27483ef0e1f8SAndres Salomon	  XO hardware.
27493ef0e1f8SAndres Salomon
2750a3128588SDaniel Drakeconfig OLPC_XO1_PM
2751a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2752fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2753a7f7f624SMasahiro Yamada	help
275497c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2755bf1ebf00SDaniel Drake
2756cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2757cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2758cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2759a7f7f624SMasahiro Yamada	help
2760cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2761cfee9597SDaniel Drake	  programmable wakeup source.
2762cfee9597SDaniel Drake
27637feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27647feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
276592e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2766ed8e47feSRandy Dunlap	depends on INPUT=y
2767d8d01a63SDaniel Drake	select POWER_SUPPLY
2768a7f7f624SMasahiro Yamada	help
27697feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27707bc74b3dSDaniel Drake	   - EC-driven system wakeups
27717feda8e9SDaniel Drake	   - Power button
27727bc74b3dSDaniel Drake	   - Ebook switch
27732cf2baeaSDaniel Drake	   - Lid switch
2774e1040ac6SDaniel Drake	   - AC adapter status updates
2775e1040ac6SDaniel Drake	   - Battery status updates
27767feda8e9SDaniel Drake
2777a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2778a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2779d8d01a63SDaniel Drake	depends on OLPC && ACPI
2780d8d01a63SDaniel Drake	select POWER_SUPPLY
2781a7f7f624SMasahiro Yamada	help
2782a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2783a0f30f59SDaniel Drake	   - EC-driven system wakeups
2784a0f30f59SDaniel Drake	   - AC adapter status updates
2785a0f30f59SDaniel Drake	   - Battery status updates
2786e279b6c1SSam Ravnborg
2787d4f3e350SEd Wildgooseconfig ALIX
2788d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2789d4f3e350SEd Wildgoose	select GPIOLIB
2790a7f7f624SMasahiro Yamada	help
2791d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2792d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2793d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2794d4f3e350SEd Wildgoose	  get added here.
2795d4f3e350SEd Wildgoose
2796d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2797d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2798d4f3e350SEd Wildgoose
2799d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2800d4f3e350SEd Wildgoose
2801da4e3302SPhilip Prindevilleconfig NET5501
2802da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2803da4e3302SPhilip Prindeville	select GPIOLIB
2804a7f7f624SMasahiro Yamada	help
2805da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2806da4e3302SPhilip Prindeville
28073197059aSPhilip A. Prindevilleconfig GEOS
28083197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
28093197059aSPhilip A. Prindeville	select GPIOLIB
28103197059aSPhilip A. Prindeville	depends on DMI
2811a7f7f624SMasahiro Yamada	help
28123197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
28133197059aSPhilip A. Prindeville
28147d029125SVivien Didelotconfig TS5500
28157d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28167d029125SVivien Didelot	depends on MELAN
28177d029125SVivien Didelot	select CHECK_SIGNATURE
28187d029125SVivien Didelot	select NEW_LEDS
28197d029125SVivien Didelot	select LEDS_CLASS
2820a7f7f624SMasahiro Yamada	help
28217d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28227d029125SVivien Didelot
2823e279b6c1SSam Ravnborgendif # X86_32
2824e279b6c1SSam Ravnborg
282523ac4ae8SAndreas Herrmannconfig AMD_NB
2826e279b6c1SSam Ravnborg	def_bool y
28270e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2828e279b6c1SSam Ravnborg
2829e279b6c1SSam Ravnborgendmenu
2830e279b6c1SSam Ravnborg
28311572497cSChristoph Hellwigmenu "Binary Emulations"
2832e279b6c1SSam Ravnborg
2833e279b6c1SSam Ravnborgconfig IA32_EMULATION
2834e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2835e279b6c1SSam Ravnborg	depends on X86_64
283639f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2837d1603990SRandy Dunlap	select BINFMT_ELF
283839f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2839a7f7f624SMasahiro Yamada	help
28405fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28415fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28425fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2843e279b6c1SSam Ravnborg
284483a44a4fSMasahiro Yamadaconfig X86_X32_ABI
28456ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28469b54050bSBrian Gerst	depends on X86_64
2847aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2848aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
2849aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
2850aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
2851aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2852a7f7f624SMasahiro Yamada	help
28535fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28545fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28555fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28565fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28575fd92e65SH. J. Lu
2858953fee1dSIngo Molnarconfig COMPAT_32
2859953fee1dSIngo Molnar	def_bool y
2860953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2861953fee1dSIngo Molnar	select HAVE_UID16
2862953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2863953fee1dSIngo Molnar
2864e279b6c1SSam Ravnborgconfig COMPAT
28653c2362e6SHarvey Harrison	def_bool y
286683a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
2867e279b6c1SSam Ravnborg
2868e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28693120e25eSJan Beulich	def_bool y
2870a9251280SLinus Torvalds	depends on COMPAT
2871ee009e4aSDavid Howells
2872e279b6c1SSam Ravnborgendmenu
2873e279b6c1SSam Ravnborg
2874e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2875e5beae16SKeith Packard	def_bool y
2876e5beae16SKeith Packard	depends on X86_32
2877e5beae16SKeith Packard
2878edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28795e8ebd84SJason A. Donenfeld
28805e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2881