xref: /linux/arch/x86/Kconfig (revision c6dbd3e5e69cf3ca47a3864115d4cbdd44619243)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	 We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	 in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	 generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	 only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
72fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
73399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7421266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
75b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
766471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7772d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
78316d097cSDave Hansen	select ARCH_HAS_FILTER_PGPROT
796974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
80957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
810f1441b4SPeter Zijlstra	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
820c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8310bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
840ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8617596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
873010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
880aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
89ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
90d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
91d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
92ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
93ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
94ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9525c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
96c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
977e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
9863703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
996471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1006471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10177fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1025e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1033599fe12SThomas Gleixner	select ARCH_STACKWALK
1042c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1056471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1065d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
1076471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
10814df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
109583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
110583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1116471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
112dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1136471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1146471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1152ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
116ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
11781c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
118c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
11951c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
1203876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12159612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
12238d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
123b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
12410916706SShile Zhang	select BUILDTIME_TABLE_SORT
1256471b825SIngo Molnar	select CLKEVT_I8253
1266471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1276471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1286471b825SIngo Molnar	select DCACHE_WORD_ACCESS
1293aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
13045471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
13145471cd9SLinus Torvalds	select EDAC_SUPPORT
1326471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1336471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1346471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1356471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
13661dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1376471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
13827d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1396471b825SIngo Molnar	select GENERIC_FIND_FIRST_BIT
1406471b825SIngo Molnar	select GENERIC_IOMAP
141c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1420fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
143ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1446471b825SIngo Molnar	select GENERIC_IRQ_PROBE
145c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1466471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1476471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1482ae27137SSteven Price	select GENERIC_PTDUMP
1496471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1506471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1517ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
152550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
15339656e83SChristoph Hellwig	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
15417e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1557edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1566471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1576471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1586471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1596471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1606471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
1616471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
162b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
163d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1640609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1651dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1666471b825SIngo Molnar	select HAVE_ARCH_KGDB
1679e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1689e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1691b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
170271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1716471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
172f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
173afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1746471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1756471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
176a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
177b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1787677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
179e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
180fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
181c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1822ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1836471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1846471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
1856471b825SIngo Molnar	select HAVE_CONTEXT_TRACKING		if X86_64
186d1f250e2SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
1876471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
1886dafca97SSami Tolvanen	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
1896471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
1909c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
191677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
19206aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
19302a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
194562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
195c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
196503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
19703f5781bSWang YanQing	select HAVE_EBPF_JIT
19858340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
1996630a8e5SChristoph Hellwig	select HAVE_EISA
2005f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
20167a929e0SChristoph Hellwig	select HAVE_FAST_GUP
202644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2036471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2044a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2056471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2066b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2070067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2086471b825SIngo Molnar	select HAVE_IOREMAP_PROT
209624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2106471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2116471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2126471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2136471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2146471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2156471b825SIngo Molnar	select HAVE_KERNEL_LZO
2166471b825SIngo Molnar	select HAVE_KERNEL_XZ
217fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2186471b825SIngo Molnar	select HAVE_KPROBES
2196471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
220540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2216471b825SIngo Molnar	select HAVE_KRETPROBES
2226471b825SIngo Molnar	select HAVE_KVM
2236471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2240102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
225ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2269f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
227be37c98dSKalesh Singh	select HAVE_MOVE_PUD
22842a0bb3fSPetr Mladek	select HAVE_NMI
2296471b825SIngo Molnar	select HAVE_OPTPROBES
2306471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2316471b825SIngo Molnar	select HAVE_PERF_EVENTS
232c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
23392e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
234eb01d42aSChristoph Hellwig	select HAVE_PCI
235c5e63197SJiri Olsa	select HAVE_PERF_REGS
236c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
237ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
23800998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2396471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
2406415b38bSJiri Slaby	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
2413c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
242cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
243d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
244c763ea26SIngo Molnar	select HAVE_STACK_VALIDATION		if X86_64
245e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
2461e7e4788SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
2476ef869e0SMichal Hocko	select HAVE_PREEMPT_DYNAMIC
248d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
2496471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2506471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2517c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2527ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
25305736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
254c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
25586596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2562eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
257625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2586471b825SIngo Molnar	select PERF_EVENTS
2593195ef59SPrarit Bhargava	select RTC_LIB
260d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2616471b825SIngo Molnar	select SPARSE_IRQ
26283fe27eaSPranith Kumar	select SRCU
2631e7e4788SJosh Poimboeuf	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
2646471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
26515f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2664aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2676471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2686471b825SIngo Molnar	select VIRT_TO_BUS
2693b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2706471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2710c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
2729e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
2737d8330a5SBalbir Singh
274ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
2753120e25eSJan Beulich	def_bool y
2763120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
277ba7e4d13SIngo Molnar
27851b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
27951b26adaSLinus Torvalds	string
28051b26adaSLinus Torvalds	default "elf32-i386" if X86_32
28151b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
28251b26adaSLinus Torvalds
2838d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
2843c2362e6SHarvey Harrison	def_bool y
2858d5fffb9SSam Ravnborg
2868d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
2873c2362e6SHarvey Harrison	def_bool y
2888d5fffb9SSam Ravnborg
2898d5fffb9SSam Ravnborgconfig MMU
2903c2362e6SHarvey Harrison	def_bool y
2918d5fffb9SSam Ravnborg
2929e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
2939e08f57dSDaniel Cashman	default 28 if 64BIT
2949e08f57dSDaniel Cashman	default 8
2959e08f57dSDaniel Cashman
2969e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
2979e08f57dSDaniel Cashman	default 32 if 64BIT
2989e08f57dSDaniel Cashman	default 16
2999e08f57dSDaniel Cashman
3009e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3019e08f57dSDaniel Cashman	default 8
3029e08f57dSDaniel Cashman
3039e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3049e08f57dSDaniel Cashman	default 16
3059e08f57dSDaniel Cashman
3068d5fffb9SSam Ravnborgconfig SBUS
3078d5fffb9SSam Ravnborg	bool
3088d5fffb9SSam Ravnborg
3098d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3103120e25eSJan Beulich	def_bool y
3113120e25eSJan Beulich	depends on ISA_DMA_API
3128d5fffb9SSam Ravnborg
3138d5fffb9SSam Ravnborgconfig GENERIC_BUG
3143c2362e6SHarvey Harrison	def_bool y
3158d5fffb9SSam Ravnborg	depends on BUG
316b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
317b93a531eSJan Beulich
318b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
319b93a531eSJan Beulich	bool
3208d5fffb9SSam Ravnborg
3218d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3223120e25eSJan Beulich	def_bool y
3233120e25eSJan Beulich	depends on ISA_DMA_API
3248d5fffb9SSam Ravnborg
3251032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3261032c0baSSam Ravnborg	def_bool y
3271032c0baSSam Ravnborg
3289a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3299a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3308d5fffb9SSam Ravnborg
331316d097cSDave Hansenconfig ARCH_HAS_FILTER_PGPROT
332316d097cSDave Hansen	def_bool y
333316d097cSDave Hansen
334dd5af90aSMike Travisconfig HAVE_SETUP_PER_CPU_AREA
33589c9c4c5SBrian Gerst	def_bool y
336b32ef636Stravis@sgi.com
33708fc4580STejun Heoconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
33808fc4580STejun Heo	def_bool y
33908fc4580STejun Heo
34008fc4580STejun Heoconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
34111124411STejun Heo	def_bool y
34211124411STejun Heo
343801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
344801e4062SJohannes Berg	def_bool y
345801e4062SJohannes Berg
346d7109fe3SAndy Shevchenkoconfig ARCH_NR_GPIO
347d7109fe3SAndy Shevchenko	int
348d7109fe3SAndy Shevchenko	default 1024 if X86_64
349d7109fe3SAndy Shevchenko	default 512
350d7109fe3SAndy Shevchenko
351f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
352f4cb5700SJohannes Berg	def_bool y
353f4cb5700SJohannes Berg
35453313b2cSSteve Capperconfig ARCH_WANT_GENERAL_HUGETLB
35553313b2cSSteve Capper	def_bool y
35653313b2cSSteve Capper
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"
46876b04384SDavid Woodhouse	default y
46976b04384SDavid Woodhouse	help
47076b04384SDavid Woodhouse	  Compile kernel with the retpoline compiler options to guard against
47176b04384SDavid Woodhouse	  kernel-to-user data leaks by avoiding speculative indirect
47276b04384SDavid Woodhouse	  branches. Requires a compiler with -mindirect-branch=thunk-extern
47376b04384SDavid Woodhouse	  support for full protection. The kernel may run slower.
47476b04384SDavid Woodhouse
475e463a09aSPeter Zijlstraconfig CC_HAS_SLS
476e463a09aSPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
477e463a09aSPeter Zijlstra
478e463a09aSPeter Zijlstraconfig SLS
479e463a09aSPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
480e463a09aSPeter Zijlstra	depends on CC_HAS_SLS && X86_64
481e463a09aSPeter Zijlstra	default n
482e463a09aSPeter Zijlstra	help
483e463a09aSPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
484e463a09aSPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
485e463a09aSPeter Zijlstra	  larger.
486e463a09aSPeter Zijlstra
487e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
488e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4896fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
49059fe5a77SThomas Gleixner	select KERNFS
491e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
49278e99b4aSFenghua Yu	help
493e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4946fe07ce3SBabu Moger
4956fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4966fe07ce3SBabu Moger	  usage by the CPU.
4976fe07ce3SBabu Moger
4986fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4996fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
5006fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
5016fe07ce3SBabu Moger
5026fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
5036fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
5046fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50578e99b4aSFenghua Yu
50678e99b4aSFenghua Yu	  Say N if unsure.
50778e99b4aSFenghua Yu
5088425091fSRavikiran G Thirumalaiif X86_32
509a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
510a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
511a0d0bb4dSRandy Dunlap	depends on SMP
512a7f7f624SMasahiro Yamada	help
513e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
514a0d0bb4dSRandy Dunlap
515c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
516c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
517c5c606d9SRavikiran G Thirumalai	default y
518a7f7f624SMasahiro Yamada	help
51906ac8346SIngo Molnar	  If you disable this option then the kernel will only support
52006ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
52106ac8346SIngo Molnar	  systems out there.)
52206ac8346SIngo Molnar
5238425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5248425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
525cb7b8023SBen Hutchings		Goldfish (Android emulator)
5268425091fSRavikiran G Thirumalai		AMD Elan
5278425091fSRavikiran G Thirumalai		RDC R-321x SoC
5288425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52983125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5303f4110a4SThomas Gleixner		Moorestown MID devices
53106ac8346SIngo Molnar
53206ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
53306ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
5348425091fSRavikiran G Thirumalaiendif
53506ac8346SIngo Molnar
5368425091fSRavikiran G Thirumalaiif X86_64
5378425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5388425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5398425091fSRavikiran G Thirumalai	default y
540a7f7f624SMasahiro Yamada	help
5418425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5428425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5438425091fSRavikiran G Thirumalai	  systems out there.)
5448425091fSRavikiran G Thirumalai
5458425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5468425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54744b111b5SSteffen Persvold		Numascale NumaChip
5488425091fSRavikiran G Thirumalai		ScaleMP vSMP
5498425091fSRavikiran G Thirumalai		SGI Ultraviolet
5508425091fSRavikiran G Thirumalai
5518425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5528425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
5538425091fSRavikiran G Thirumalaiendif
554c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
555c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55644b111b5SSteffen Persvoldconfig X86_NUMACHIP
55744b111b5SSteffen Persvold	bool "Numascale NumaChip"
55844b111b5SSteffen Persvold	depends on X86_64
55944b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
56044b111b5SSteffen Persvold	depends on NUMA
56144b111b5SSteffen Persvold	depends on SMP
56244b111b5SSteffen Persvold	depends on X86_X2APIC
563f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
564a7f7f624SMasahiro Yamada	help
56544b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56644b111b5SSteffen Persvold	  enable more than ~168 cores.
56744b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56803b48632SNick Piggin
5696a48565eSIngo Molnarconfig X86_VSMP
570c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5716276a074SBorislav Petkov	select HYPERVISOR_GUEST
5726a48565eSIngo Molnar	select PARAVIRT
5736a48565eSIngo Molnar	depends on X86_64 && PCI
574c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
575ead91d4bSShai Fultheim	depends on SMP
576a7f7f624SMasahiro Yamada	help
5776a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5786a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5796a48565eSIngo Molnar	  if you have one of these machines.
5806a48565eSIngo Molnar
581c5c606d9SRavikiran G Thirumalaiconfig X86_UV
582c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
583c5c606d9SRavikiran G Thirumalai	depends on X86_64
584c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58554c28d29SJack Steiner	depends on NUMA
5861ecb4ae5SAndrew Morton	depends on EFI
587c2209ea5SIngo Molnar	depends on KEXEC_CORE
5889d6c26e7SSuresh Siddha	depends on X86_X2APIC
5891222e564SIngo Molnar	depends on PCI
590a7f7f624SMasahiro Yamada	help
591c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
592c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
593c5c606d9SRavikiran G Thirumalai
594c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
595c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
596506f1d07SSam Ravnborg
597ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
598ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
599cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
600a7f7f624SMasahiro Yamada	help
601ddd70cf9SJun Nakajima	 Enable support for the Goldfish virtual platform used primarily
602ddd70cf9SJun Nakajima	 for Android development. Unless you are building for the Android
603ddd70cf9SJun Nakajima	 Goldfish emulator say N here.
604ddd70cf9SJun Nakajima
605c751e17bSThomas Gleixnerconfig X86_INTEL_CE
606c751e17bSThomas Gleixner	bool "CE4100 TV platform"
607c751e17bSThomas Gleixner	depends on PCI
608c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6096084a6e2SJiang Liu	depends on X86_IO_APIC
610c751e17bSThomas Gleixner	depends on X86_32
611c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
61237bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
613da6b737bSSebastian Andrzej Siewior	select OF
614da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
615a7f7f624SMasahiro Yamada	help
616c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
617c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
618c751e17bSThomas Gleixner	  boxes and media devices.
619c751e17bSThomas Gleixner
6204cb9b00fSDavid Cohenconfig X86_INTEL_MID
62143605ef1SAlan Cox	bool "Intel MID platform support"
62243605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
623edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6241ea7c673SAlan Cox	depends on PCI
6253fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6261ea7c673SAlan Cox	depends on X86_IO_APIC
6274cb9b00fSDavid Cohen	select I2C
6287c9c3a1eSAlan Cox	select DW_APB_TIMER
62954b34aa0SMika Westerberg	select INTEL_SCU_PCI
630a7f7f624SMasahiro Yamada	help
6314cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6324cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6334cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6341ea7c673SAlan Cox
6354cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6364cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63743605ef1SAlan Cox
6388bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6398bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6408bbc2a13SBryan O'Donoghue	depends on X86_32
6418bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6428bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6438bbc2a13SBryan O'Donoghue	depends on X86_TSC
6448bbc2a13SBryan O'Donoghue	depends on PCI
6458bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6468bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6478bbc2a13SBryan O'Donoghue	select IOSF_MBI
6488bbc2a13SBryan O'Donoghue	select INTEL_IMR
6499ab6eb51SAndy Shevchenko	select COMMON_CLK
650a7f7f624SMasahiro Yamada	help
6518bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6528bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6538bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6548bbc2a13SBryan O'Donoghue
6553d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6563d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6575962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6583d48aab1SMika Westerberg	select COMMON_CLK
6590f531431SMathias Nyman	select PINCTRL
660eebb3e8dSAndy Shevchenko	select IOSF_MBI
661a7f7f624SMasahiro Yamada	help
6623d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6633d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6640f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6650f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6663d48aab1SMika Westerberg
66792082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66892082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66992082a88SKen Xue	depends on ACPI
67092082a88SKen Xue	select COMMON_CLK
67192082a88SKen Xue	select PINCTRL
672a7f7f624SMasahiro Yamada	help
67392082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
67492082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67592082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67692082a88SKen Xue	  implemented under PINCTRL subsystem.
67792082a88SKen Xue
678ced3ce76SDavid E. Boxconfig IOSF_MBI
679ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
680ced3ce76SDavid E. Box	depends on PCI
681a7f7f624SMasahiro Yamada	help
682ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
683ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
684ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
685ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
686ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
687ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
688ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
689ced3ce76SDavid E. Box	   - BayTrail
690ced3ce76SDavid E. Box	   - Braswell
691ced3ce76SDavid E. Box	   - Quark
692ced3ce76SDavid E. Box
693ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
694ced3ce76SDavid E. Box
695ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
696ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
697ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
698a7f7f624SMasahiro Yamada	help
699ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
700ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
701ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
702ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
703ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
704ed2226bdSDavid E. Box	  device they want to access.
705ed2226bdSDavid E. Box
706ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
707ed2226bdSDavid E. Box
708c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
709c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
710506f1d07SSam Ravnborg	depends on X86_32
711c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
712c5c606d9SRavikiran G Thirumalai	select M486
713c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
714a7f7f624SMasahiro Yamada	help
715c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
716c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
717c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
718c5c606d9SRavikiran G Thirumalai
719e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7209c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7219c398017SIngo Molnar	depends on X86_32 && SMP
722c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
723a7f7f624SMasahiro Yamada	help
724b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
725b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
726b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
727b5660ba7SH. Peter Anvin	  one and will fallback to default.
728d49c4288SYinghai Lu
729c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
730d49c4288SYinghai Lu
731d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7326fc108a0SJan Beulich	def_bool y
733d949f36fSLinus Torvalds	# MCE code calls memory_failure():
734d949f36fSLinus Torvalds	depends on X86_MCE
735d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
736d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
737d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
738d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
739d949f36fSLinus Torvalds
74083125a3aSAlessandro Rubiniconfig STA2X11
74183125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
74283125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
74383125a3aSAlessandro Rubini	select SWIOTLB
74483125a3aSAlessandro Rubini	select MFD_STA2X11
7450145071bSLinus Walleij	select GPIOLIB
746a7f7f624SMasahiro Yamada	help
74783125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74883125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74983125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
75083125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
75183125a3aSAlessandro Rubini	  standard PC machines.
75283125a3aSAlessandro Rubini
75382148d1dSShérabconfig X86_32_IRIS
75482148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75582148d1dSShérab	depends on X86_32
756a7f7f624SMasahiro Yamada	help
75782148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75882148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75982148d1dSShérab	  needed to do so, which is what this module does at
76082148d1dSShérab	  kernel shutdown.
76182148d1dSShérab
76282148d1dSShérab	  This is only for Iris machines from EuroBraille.
76382148d1dSShérab
76482148d1dSShérab	  If unused, say N.
76582148d1dSShérab
766ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7673c2362e6SHarvey Harrison	def_bool y
7683c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
769a87d0914SKen Chen	depends on X86
770a7f7f624SMasahiro Yamada	help
771506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
772506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
773506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
774506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
775506f1d07SSam Ravnborg
776506f1d07SSam Ravnborg	  If in doubt, say "Y".
777506f1d07SSam Ravnborg
7786276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7796276a074SBorislav Petkov	bool "Linux guest support"
780a7f7f624SMasahiro Yamada	help
7816276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7826276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7836276a074SBorislav Petkov	  setup.
784506f1d07SSam Ravnborg
7856276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7866276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
787506f1d07SSam Ravnborg
7886276a074SBorislav Petkovif HYPERVISOR_GUEST
789506f1d07SSam Ravnborg
790e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
791e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
792a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
793a7f7f624SMasahiro Yamada	help
794e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
795e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
796e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
797e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
798e61bd94aSEduardo Pereira Habkost
799c00a280aSJuergen Grossconfig PARAVIRT_XXL
800c00a280aSJuergen Gross	bool
801c00a280aSJuergen Gross
8026276a074SBorislav Petkovconfig PARAVIRT_DEBUG
8036276a074SBorislav Petkov	bool "paravirt-ops debugging"
8046276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
805a7f7f624SMasahiro Yamada	help
8066276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8076276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8086276a074SBorislav Petkov
809b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
810b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8116ea30386SKees Cook	depends on PARAVIRT && SMP
812a7f7f624SMasahiro Yamada	help
813b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
814b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
815b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
816b4ecc126SJeremy Fitzhardinge
8174c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8184c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
819b4ecc126SJeremy Fitzhardinge
8204c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
821b4ecc126SJeremy Fitzhardinge
822ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
823ecca2502SZhao Yakui	def_bool n
824ecca2502SZhao Yakui
8256276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8266276a074SBorislav Petkov
8276276a074SBorislav Petkovconfig KVM_GUEST
8286276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8296276a074SBorislav Petkov	depends on PARAVIRT
8306276a074SBorislav Petkov	select PARAVIRT_CLOCK
831a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
832b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8336276a074SBorislav Petkov	default y
834a7f7f624SMasahiro Yamada	help
8356276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8366276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8376276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8386276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8396276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8406276a074SBorislav Petkov
841a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
842a1c4423bSMarcelo Tosatti	def_bool n
843a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
844a1c4423bSMarcelo Tosatti	help
845a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
846a1c4423bSMarcelo Tosatti
8477733607fSMaran Wilsonconfig PVH
8487733607fSMaran Wilson	bool "Support for running PVH guests"
849a7f7f624SMasahiro Yamada	help
8507733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8517733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8527733607fSMaran Wilson
8536276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8546276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8556276a074SBorislav Petkov	depends on PARAVIRT
856a7f7f624SMasahiro Yamada	help
8576276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8586276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8596276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8606276a074SBorislav Petkov	  that, there can be a small performance impact.
8616276a074SBorislav Petkov
8626276a074SBorislav Petkov	  If in doubt, say N here.
8636276a074SBorislav Petkov
8647af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8657af192c9SGerd Hoffmann	bool
8667af192c9SGerd Hoffmann
8674a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8684a362601SJan Kiszka	bool "Jailhouse non-root cell support"
869abde587bSArnd Bergmann	depends on X86_64 && PCI
87087e65d05SJan Kiszka	select X86_PM_TIMER
871a7f7f624SMasahiro Yamada	help
8724a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8734a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8744a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8754a362601SJan Kiszka
876ec7972c9SZhao Yakuiconfig ACRN_GUEST
877ec7972c9SZhao Yakui	bool "ACRN Guest support"
878ec7972c9SZhao Yakui	depends on X86_64
879498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
880ec7972c9SZhao Yakui	help
881ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
882ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
883ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
884ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
885ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
886ec7972c9SZhao Yakui
8876276a074SBorislav Petkovendif #HYPERVISOR_GUEST
88897349135SJeremy Fitzhardinge
889506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
890506f1d07SSam Ravnborg
891506f1d07SSam Ravnborgconfig HPET_TIMER
8923c2362e6SHarvey Harrison	def_bool X86_64
893506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
894a7f7f624SMasahiro Yamada	help
895506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
896506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
897506f1d07SSam Ravnborg	  present.
898506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
899506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
900506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9014e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9024e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
903506f1d07SSam Ravnborg
904506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
905506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
906506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
907506f1d07SSam Ravnborg
908506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
909506f1d07SSam Ravnborg
910506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9113c2362e6SHarvey Harrison	def_bool y
9123228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
913506f1d07SSam Ravnborg
9146a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
915506f1d07SSam Ravnborg# The code disables itself when not needed.
9167ae9392cSThomas Petazzoniconfig DMI
9177ae9392cSThomas Petazzoni	default y
918cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9196a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
920a7f7f624SMasahiro Yamada	help
9217ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9227ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9237ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9247ae9392cSThomas Petazzoni	  BIOS code.
9257ae9392cSThomas Petazzoni
926506f1d07SSam Ravnborgconfig GART_IOMMU
92738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9282f9237d4SChristoph Hellwig	select DMA_OPS
929a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
930506f1d07SSam Ravnborg	select SWIOTLB
93123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
932a7f7f624SMasahiro Yamada	help
933ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
934ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
935ced3c42cSIngo Molnar
936ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
937ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
938ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
939ced3c42cSIngo Molnar
940ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
941ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
942ced3c42cSIngo Molnar
943ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
944ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
945ced3c42cSIngo Molnar	  32-bit limited device.
946ced3c42cSIngo Molnar
947ced3c42cSIngo Molnar	  If unsure, say Y.
948506f1d07SSam Ravnborg
9491184dc2fSMike Travisconfig MAXSMP
950ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9516ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
95236f5101aSMike Travis	select CPUMASK_OFFSTACK
953a7f7f624SMasahiro Yamada	help
954ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9551184dc2fSMike Travis	  If unsure, say N.
956506f1d07SSam Ravnborg
957aec6487eSIngo Molnar#
958aec6487eSIngo Molnar# The maximum number of CPUs supported:
959aec6487eSIngo Molnar#
960aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
961aec6487eSIngo Molnar# and which can be configured interactively in the
962aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
963aec6487eSIngo Molnar#
964aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
965aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
966aec6487eSIngo Molnar#
967aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
968aec6487eSIngo Molnar#   interactive configuration. )
969aec6487eSIngo Molnar#
970a0d0bb4dSRandy Dunlap
971aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
972a0d0bb4dSRandy Dunlap	int
973aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
974a0d0bb4dSRandy Dunlap	default    1 if !SMP
975a0d0bb4dSRandy Dunlap	default    2
976a0d0bb4dSRandy Dunlap
977aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
978a0d0bb4dSRandy Dunlap	int
979a0d0bb4dSRandy Dunlap	depends on X86_32
980aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
981aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
982a0d0bb4dSRandy Dunlap	default    1 if !SMP
983a0d0bb4dSRandy Dunlap
984aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
985a0d0bb4dSRandy Dunlap	int
986a0d0bb4dSRandy Dunlap	depends on X86_64
9871edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
9881edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
989a0d0bb4dSRandy Dunlap	default    1 if !SMP
990aec6487eSIngo Molnar
991aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
992aec6487eSIngo Molnar	int
993aec6487eSIngo Molnar	depends on X86_32
994aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
995aec6487eSIngo Molnar	default    8 if  SMP
996aec6487eSIngo Molnar	default    1 if !SMP
997aec6487eSIngo Molnar
998aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
999aec6487eSIngo Molnar	int
1000aec6487eSIngo Molnar	depends on X86_64
1001a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1002a0d0bb4dSRandy Dunlap	default   64 if  SMP
1003aec6487eSIngo Molnar	default    1 if !SMP
1004a0d0bb4dSRandy Dunlap
1005506f1d07SSam Ravnborgconfig NR_CPUS
100636f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1007aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1008aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1009a7f7f624SMasahiro Yamada	help
1010506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1011bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1012cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1013506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1014506f1d07SSam Ravnborg
1015aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1016aec6487eSIngo Molnar	  to the kernel image.
1017506f1d07SSam Ravnborg
101866558b73STim Chenconfig SCHED_CLUSTER
101966558b73STim Chen	bool "Cluster scheduler support"
102066558b73STim Chen	depends on SMP
102166558b73STim Chen	default y
102266558b73STim Chen	help
102366558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
102466558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
102566558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
102666558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
102766558b73STim Chen	  busses.
102866558b73STim Chen
1029506f1d07SSam Ravnborgconfig SCHED_SMT
1030dbe73364SThomas Gleixner	def_bool y if SMP
1031506f1d07SSam Ravnborg
1032506f1d07SSam Ravnborgconfig SCHED_MC
10333c2362e6SHarvey Harrison	def_bool y
10343c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1035c8e56d20SBorislav Petkov	depends on SMP
1036a7f7f624SMasahiro Yamada	help
1037506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1038506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1039506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1040506f1d07SSam Ravnborg
1041de966cf4STim Chenconfig SCHED_MC_PRIO
1042de966cf4STim Chen	bool "CPU core priorities scheduler support"
10430a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10440a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10450a21fc12SIngo Molnar	select CPU_FREQ
1046de966cf4STim Chen	default y
1047a7f7f624SMasahiro Yamada	help
1048de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1049de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1050de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1051de966cf4STim Chen	  single threaded workloads) than others.
1052de966cf4STim Chen
1053de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1054de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1055de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1056de966cf4STim Chen	  overall system performance can be achieved.
1057de966cf4STim Chen
1058de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1059de966cf4STim Chen
1060de966cf4STim Chen	  If unsure say Y here.
10615e76b2abSTim Chen
106230b8b006SThomas Gleixnerconfig UP_LATE_INIT
106330b8b006SThomas Gleixner	def_bool y
1064ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
106530b8b006SThomas Gleixner
1066506f1d07SSam Ravnborgconfig X86_UP_APIC
106750849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
106850849eefSJan Beulich	default PCI_MSI
106938a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1070a7f7f624SMasahiro Yamada	help
1071506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1072506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1073506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1074506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1075506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1076506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1077506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1078506f1d07SSam Ravnborg	  lockups.
1079506f1d07SSam Ravnborg
1080506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1081506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1082506f1d07SSam Ravnborg	depends on X86_UP_APIC
1083a7f7f624SMasahiro Yamada	help
1084506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1085506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1086506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1087506f1d07SSam Ravnborg
1088506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1089506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1090506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1091506f1d07SSam Ravnborg
1092506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
10933c2362e6SHarvey Harrison	def_bool y
10940dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1095b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
109652f518a3SJiang Liu	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1097506f1d07SSam Ravnborg
1098506f1d07SSam Ravnborgconfig X86_IO_APIC
1099b1da1e71SJan Beulich	def_bool y
1100b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1101506f1d07SSam Ravnborg
110241b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
110341b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
110441b9eb26SStefan Assmann	depends on X86_IO_APIC
1105a7f7f624SMasahiro Yamada	help
110641b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
110741b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
110841b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
110941b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
111041b9eb26SStefan Assmann
111141b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
111241b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
111341b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
111441b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
111541b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
111641b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
111741b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
111841b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
111941b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
112041b9eb26SStefan Assmann	  down (vital) interrupt lines.
112141b9eb26SStefan Assmann
112241b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
112341b9eb26SStefan Assmann	  increased on these systems.
112441b9eb26SStefan Assmann
1125506f1d07SSam Ravnborgconfig X86_MCE
1126bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1127648ed940SChen, Gong	select GENERIC_ALLOCATOR
1128e57dbaf7SBorislav Petkov	default y
1129a7f7f624SMasahiro Yamada	help
1130bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1131bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1132506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1133bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11344efc0670SAndi Kleen
11355de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11365de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11375de97c9fSTony Luck	depends on X86_MCE
1138a7f7f624SMasahiro Yamada	help
11395de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11405de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11415de97c9fSTony Luck	  rasdaemon solution.
11425de97c9fSTony Luck
1143506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11443c2362e6SHarvey Harrison	def_bool y
11453c2362e6SHarvey Harrison	prompt "Intel MCE features"
1146c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1147a7f7f624SMasahiro Yamada	help
1148506f1d07SSam Ravnborg	   Additional support for intel specific MCE features such as
1149506f1d07SSam Ravnborg	   the thermal monitor.
1150506f1d07SSam Ravnborg
1151506f1d07SSam Ravnborgconfig X86_MCE_AMD
11523c2362e6SHarvey Harrison	def_bool y
11533c2362e6SHarvey Harrison	prompt "AMD MCE features"
1154f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1155a7f7f624SMasahiro Yamada	help
1156506f1d07SSam Ravnborg	   Additional support for AMD specific MCE features such as
1157506f1d07SSam Ravnborg	   the DRAM Error Threshold.
1158506f1d07SSam Ravnborg
11594efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11606fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1161c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1162a7f7f624SMasahiro Yamada	help
11634efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11645065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11654efc0670SAndi Kleen	  line.
11664efc0670SAndi Kleen
1167b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1168b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11696fc108a0SJan Beulich	def_bool y
1170b2762686SAndi Kleen
1171ea149b36SAndi Kleenconfig X86_MCE_INJECT
1172bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1173ea149b36SAndi Kleen	tristate "Machine check injector support"
1174a7f7f624SMasahiro Yamada	help
1175ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1176ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1177ea149b36SAndi Kleen	  QA it is safe to say n.
1178ea149b36SAndi Kleen
117907dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1180e633c65aSKan Liang
11815aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11821e642812SIngo Molnar	bool "Legacy VM86 support"
1183506f1d07SSam Ravnborg	depends on X86_32
1184a7f7f624SMasahiro Yamada	help
11855aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
11865aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
11875aef51c3SAndy Lutomirski
11885aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
11895aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
11905aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
11915aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
11925aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
11931e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
11941e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
11951e642812SIngo Molnar	  mode might be faster than emulation and you might want to
11961e642812SIngo Molnar	  enable this option.
11975aef51c3SAndy Lutomirski
11981e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
11991e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12001e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12011e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12025aef51c3SAndy Lutomirski
12031e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12041e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12055aef51c3SAndy Lutomirski
12061e642812SIngo Molnar	  If unsure, say N here.
12075aef51c3SAndy Lutomirski
12085aef51c3SAndy Lutomirskiconfig VM86
12095aef51c3SAndy Lutomirski	bool
12105aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
121134273f41SH. Peter Anvin
121234273f41SH. Peter Anvinconfig X86_16BIT
121334273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
121434273f41SH. Peter Anvin	default y
1215a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1216a7f7f624SMasahiro Yamada	help
121734273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
121834273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
121934273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
122034273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
122134273f41SH. Peter Anvin
122234273f41SH. Peter Anvinconfig X86_ESPFIX32
122334273f41SH. Peter Anvin	def_bool y
122434273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1225506f1d07SSam Ravnborg
1226197725deSH. Peter Anvinconfig X86_ESPFIX64
1227197725deSH. Peter Anvin	def_bool y
122834273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1229506f1d07SSam Ravnborg
12301ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12311ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12321ad83c85SAndy Lutomirski	default y
12331ad83c85SAndy Lutomirski	depends on X86_64
1234a7f7f624SMasahiro Yamada	help
12351ad83c85SAndy Lutomirski	 This enables emulation of the legacy vsyscall page.  Disabling
12361ad83c85SAndy Lutomirski	 it is roughly equivalent to booting with vsyscall=none, except
12371ad83c85SAndy Lutomirski	 that it will also disable the helpful warning if a program
12381ad83c85SAndy Lutomirski	 tries to use a vsyscall.  With this option set to N, offending
12391ad83c85SAndy Lutomirski	 programs will just segfault, citing addresses of the form
12401ad83c85SAndy Lutomirski	 0xffffffffff600?00.
12411ad83c85SAndy Lutomirski
12421ad83c85SAndy Lutomirski	 This option is required by many programs built before 2013, and
12431ad83c85SAndy Lutomirski	 care should be used even with newer programs if set to N.
12441ad83c85SAndy Lutomirski
12451ad83c85SAndy Lutomirski	 Disabling this option saves about 7K of kernel size and
12461ad83c85SAndy Lutomirski	 possibly 4K of additional runtime pagetable memory.
12471ad83c85SAndy Lutomirski
1248111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1249111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1250a24ca997SThomas Gleixner	default y
1251a7f7f624SMasahiro Yamada	help
1252111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1253111e7b15SThomas Gleixner	  for legacy applications.
1254111e7b15SThomas Gleixner
1255c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1256c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1257c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1258c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1259c8137aceSThomas Gleixner	  modules.
1260c8137aceSThomas Gleixner
1261c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1262c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1263a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1264a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1265c8137aceSThomas Gleixner
1266506f1d07SSam Ravnborgconfig TOSHIBA
1267506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1268506f1d07SSam Ravnborg	depends on X86_32
1269a7f7f624SMasahiro Yamada	help
1270506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1271506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1272506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1273506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1274506f1d07SSam Ravnborg
1275506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1276506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1277506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1278506f1d07SSam Ravnborg
1279506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1280506f1d07SSam Ravnborg	  Say N otherwise.
1281506f1d07SSam Ravnborg
1282506f1d07SSam Ravnborgconfig I8K
1283039ae585SPali Rohár	tristate "Dell i8k legacy laptop support"
1284ef775a0eSRandy Dunlap	depends on HWMON
1285ef775a0eSRandy Dunlap	depends on PROC_FS
1286039ae585SPali Rohár	select SENSORS_DELL_SMM
1287a7f7f624SMasahiro Yamada	help
1288039ae585SPali Rohár	  This option enables legacy /proc/i8k userspace interface in hwmon
1289039ae585SPali Rohár	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1290039ae585SPali Rohár	  temperature and allows controlling fan speeds of Dell laptops via
1291039ae585SPali Rohár	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1292039ae585SPali Rohár	  it reports also power and hotkey status. For fan speed control is
1293039ae585SPali Rohár	  needed userspace package i8kutils.
1294506f1d07SSam Ravnborg
1295039ae585SPali Rohár	  Say Y if you intend to run this kernel on old Dell laptops or want to
1296039ae585SPali Rohár	  use userspace package i8kutils.
1297506f1d07SSam Ravnborg	  Say N otherwise.
1298506f1d07SSam Ravnborg
1299506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
13009ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
13019ba16087SJan Beulich	depends on X86_32
1302a7f7f624SMasahiro Yamada	help
1303506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1304506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1305506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1306506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1307506f1d07SSam Ravnborg	  system.
1308506f1d07SSam Ravnborg
1309506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13105e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1311506f1d07SSam Ravnborg
1312506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1313506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1314506f1d07SSam Ravnborg	  Say N otherwise.
1315506f1d07SSam Ravnborg
1316506f1d07SSam Ravnborgconfig MICROCODE
13179a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13189a2bc335SBorislav Petkov	default y
131980030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1320a7f7f624SMasahiro Yamada	help
1321506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13225f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13235f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13245f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13255f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13265f9c01aaSBorislav Petkov	  the Linux kernel.
1327506f1d07SSam Ravnborg
13285f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1329cb1aaebeSMauro Carvalho Chehab	  in Documentation/x86/microcode.rst. For that you need to enable
13305f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13315f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1332506f1d07SSam Ravnborg
1333c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1334c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1335c508c46eSBenjamin Gilbert	  config option.
1336506f1d07SSam Ravnborg
13378d86f390SPeter Orubaconfig MICROCODE_INTEL
1338e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13398d86f390SPeter Oruba	depends on MICROCODE
13408d86f390SPeter Oruba	default MICROCODE
1341a7f7f624SMasahiro Yamada	help
13428d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13438d86f390SPeter Oruba	  processors.
13448d86f390SPeter Oruba
1345b8989db9SAlan	  For the current Intel microcode data package go to
1346b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1347b8989db9SAlan	  'Linux Processor Microcode Data File'.
13488d86f390SPeter Oruba
134980cc9f10SPeter Orubaconfig MICROCODE_AMD
1350e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
135180cc9f10SPeter Oruba	depends on MICROCODE
1352a7f7f624SMasahiro Yamada	help
135380cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
135480cc9f10SPeter Oruba	  processors will be enabled.
135580cc9f10SPeter Oruba
1356506f1d07SSam Ravnborgconfig MICROCODE_OLD_INTERFACE
1357c02f48e0SBorislav Petkov	bool "Ancient loading interface (DEPRECATED)"
1358c02f48e0SBorislav Petkov	default n
1359506f1d07SSam Ravnborg	depends on MICROCODE
1360a7f7f624SMasahiro Yamada	help
1361c02f48e0SBorislav Petkov	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1362c02f48e0SBorislav Petkov	  which was used by userspace tools like iucode_tool and microcode.ctl.
1363c02f48e0SBorislav Petkov	  It is inadequate because it runs too late to be able to properly
1364c02f48e0SBorislav Petkov	  load microcode on a machine and it needs special tools. Instead, you
1365c02f48e0SBorislav Petkov	  should've switched to the early loading method with the initrd or
1366cb1aaebeSMauro Carvalho Chehab	  builtin microcode by now: Documentation/x86/microcode.rst
1367506f1d07SSam Ravnborg
1368506f1d07SSam Ravnborgconfig X86_MSR
1369506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1370a7f7f624SMasahiro Yamada	help
1371506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1372506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1373506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1374506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1375506f1d07SSam Ravnborg	  systems.
1376506f1d07SSam Ravnborg
1377506f1d07SSam Ravnborgconfig X86_CPUID
1378506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1379a7f7f624SMasahiro Yamada	help
1380506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1381506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1382506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1383506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1384506f1d07SSam Ravnborg
1385506f1d07SSam Ravnborgchoice
1386506f1d07SSam Ravnborg	prompt "High Memory Support"
13876fc108a0SJan Beulich	default HIGHMEM4G
1388506f1d07SSam Ravnborg	depends on X86_32
1389506f1d07SSam Ravnborg
1390506f1d07SSam Ravnborgconfig NOHIGHMEM
1391506f1d07SSam Ravnborg	bool "off"
1392a7f7f624SMasahiro Yamada	help
1393506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1394506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1395506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1396506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1397506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1398506f1d07SSam Ravnborg	  "high memory".
1399506f1d07SSam Ravnborg
1400506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1401506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1402506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1403506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1404506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1405506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1406506f1d07SSam Ravnborg	  possible.
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1409506f1d07SSam Ravnborg	  answer "4GB" here.
1410506f1d07SSam Ravnborg
1411506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1412506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1413506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1414506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1415506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1416506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1417506f1d07SSam Ravnborg
1418506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1419506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1420506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1421506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1422506f1d07SSam Ravnborg	  kernel at boot time.)
1423506f1d07SSam Ravnborg
1424506f1d07SSam Ravnborg	  If unsure, say "off".
1425506f1d07SSam Ravnborg
1426506f1d07SSam Ravnborgconfig HIGHMEM4G
1427506f1d07SSam Ravnborg	bool "4GB"
1428a7f7f624SMasahiro Yamada	help
1429506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1430506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1431506f1d07SSam Ravnborg
1432506f1d07SSam Ravnborgconfig HIGHMEM64G
1433506f1d07SSam Ravnborg	bool "64GB"
1434225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1435506f1d07SSam Ravnborg	select X86_PAE
1436a7f7f624SMasahiro Yamada	help
1437506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1438506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1439506f1d07SSam Ravnborg
1440506f1d07SSam Ravnborgendchoice
1441506f1d07SSam Ravnborg
1442506f1d07SSam Ravnborgchoice
14436a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1444506f1d07SSam Ravnborg	default VMSPLIT_3G
1445506f1d07SSam Ravnborg	depends on X86_32
1446a7f7f624SMasahiro Yamada	help
1447506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1448506f1d07SSam Ravnborg
1449506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1450506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1451506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1452506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1453506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1454506f1d07SSam Ravnborg	  available to user programs, making the address space there
1455506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1456506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1457506f1d07SSam Ravnborg	  kernel modules.
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1460506f1d07SSam Ravnborg	  option alone!
1461506f1d07SSam Ravnborg
1462506f1d07SSam Ravnborg	config VMSPLIT_3G
1463506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1464506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1465506f1d07SSam Ravnborg		depends on !X86_PAE
1466506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1467506f1d07SSam Ravnborg	config VMSPLIT_2G
1468506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1469506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1470506f1d07SSam Ravnborg		depends on !X86_PAE
1471506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1472506f1d07SSam Ravnborg	config VMSPLIT_1G
1473506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1474506f1d07SSam Ravnborgendchoice
1475506f1d07SSam Ravnborg
1476506f1d07SSam Ravnborgconfig PAGE_OFFSET
1477506f1d07SSam Ravnborg	hex
1478506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1479506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1480506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1481506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1482506f1d07SSam Ravnborg	default 0xC0000000
1483506f1d07SSam Ravnborg	depends on X86_32
1484506f1d07SSam Ravnborg
1485506f1d07SSam Ravnborgconfig HIGHMEM
14863c2362e6SHarvey Harrison	def_bool y
1487506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1488506f1d07SSam Ravnborg
1489506f1d07SSam Ravnborgconfig X86_PAE
14909ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1491506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1492d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14939d99c712SChristian Melki	select SWIOTLB
1494a7f7f624SMasahiro Yamada	help
1495506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1496506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1497506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1498506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1499506f1d07SSam Ravnborg
150077ef56e4SKirill A. Shutemovconfig X86_5LEVEL
150177ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
150218ec1eafSKirill A. Shutemov	default y
1503eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1504162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
150577ef56e4SKirill A. Shutemov	depends on X86_64
1506a7f7f624SMasahiro Yamada	help
150777ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
150877ef56e4SKirill A. Shutemov	  upto 128 PiB of virtual address space and 4 PiB of
150977ef56e4SKirill A. Shutemov	  physical address space.
151077ef56e4SKirill A. Shutemov
151177ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
151277ef56e4SKirill A. Shutemov
15136657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15146657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
151577ef56e4SKirill A. Shutemov
1516cb1aaebeSMauro Carvalho Chehab	  See Documentation/x86/x86_64/5level-paging.rst for more
151777ef56e4SKirill A. Shutemov	  information.
151877ef56e4SKirill A. Shutemov
151977ef56e4SKirill A. Shutemov	  Say N if unsure.
152077ef56e4SKirill A. Shutemov
152110971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1522e5008abeSLuis R. Rodriguez	def_bool y
15232e1da13fSVlastimil Babka	depends on X86_64
1524a7f7f624SMasahiro Yamada	help
152510971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
152610971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
152710971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
152810971ab2SIngo Molnar	  that we have them enabled.
15299e899816SNick Piggin
15305c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15315c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15325c280cf6SThomas Gleixner	depends on DEBUG_FS
1533a7f7f624SMasahiro Yamada	help
1534b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1535a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15365c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15375c280cf6SThomas Gleixner
15387744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15397744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15407744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
154182fef0adSDavid Rientjes	select DMA_COHERENT_POOL
154294d49eb3SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
1543ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
15449087c375STom Lendacky	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1545597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
154622916417STom Lendacky	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1547aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
1548a7f7f624SMasahiro Yamada	help
15497744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15507744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15517744ccdbSTom Lendacky	  Encryption (SME).
15527744ccdbSTom Lendacky
15537744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15547744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15557744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1556a7f7f624SMasahiro Yamada	help
15577744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15587744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15597744ccdbSTom Lendacky
15607744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15617744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15627744ccdbSTom Lendacky
15637744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15647744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15657744ccdbSTom Lendacky
1566506f1d07SSam Ravnborg# Common NUMA Features
1567506f1d07SSam Ravnborgconfig NUMA
1568e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1569506f1d07SSam Ravnborg	depends on SMP
1570b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1571b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
1572a7f7f624SMasahiro Yamada	help
1573e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1574fd51b2d7SKOSAKI Motohiro
1575506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1576506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1577506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1578506f1d07SSam Ravnborg
1579c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1580fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1581fd51b2d7SKOSAKI Motohiro
1582b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15837cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1584fd51b2d7SKOSAKI Motohiro
1585fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1586506f1d07SSam Ravnborg
1587eec1d4faSHans Rosenfeldconfig AMD_NUMA
15883c2362e6SHarvey Harrison	def_bool y
15893c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15905da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1591a7f7f624SMasahiro Yamada	help
1592eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1593eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1594eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1595eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1596eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1597506f1d07SSam Ravnborg
1598506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
15993c2362e6SHarvey Harrison	def_bool y
16003c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1601506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1602506f1d07SSam Ravnborg	select ACPI_NUMA
1603a7f7f624SMasahiro Yamada	help
1604506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1605506f1d07SSam Ravnborg
1606506f1d07SSam Ravnborgconfig NUMA_EMU
1607506f1d07SSam Ravnborg	bool "NUMA emulation"
16081b7e03efSTejun Heo	depends on NUMA
1609a7f7f624SMasahiro Yamada	help
1610506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1611506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1612506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1613506f1d07SSam Ravnborg
1614506f1d07SSam Ravnborgconfig NODES_SHIFT
1615d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
161651591e31SDavid Rientjes	range 1 10
161751591e31SDavid Rientjes	default "10" if MAXSMP
1618506f1d07SSam Ravnborg	default "6" if X86_64
1619506f1d07SSam Ravnborg	default "3"
1620a9ee6cf5SMike Rapoport	depends on NUMA
1621a7f7f624SMasahiro Yamada	help
16221184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1623692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1624506f1d07SSam Ravnborg
1625506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1626506f1d07SSam Ravnborg	def_bool y
16273b16651fSTejun Heo	depends on X86_32 && !NUMA
1628506f1d07SSam Ravnborg
1629506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1630506f1d07SSam Ravnborg	def_bool y
16316ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1632506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1633506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1634506f1d07SSam Ravnborg
16353b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16366ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16373b16651fSTejun Heo
1638506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1639506f1d07SSam Ravnborg	def_bool y
1640b263295dSChristoph Lameter	depends on ARCH_SPARSEMEM_ENABLE
1641506f1d07SSam Ravnborg
1642506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1643a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16445c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1645a0842b70SToshi Kani	help
1646a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1647cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1648a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1649506f1d07SSam Ravnborg
16503b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16513b16651fSTejun Heo	def_bool y
16523b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16533b16651fSTejun Heo
1654a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1655a29815a3SAvi Kivity	hex
1656a29815a3SAvi Kivity	default 0 if X86_32
1657a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1658a29815a3SAvi Kivity
16597a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16607a67832cSDan Williams	bool
16617a67832cSDan Williams
1662ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16637a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16649f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16659f53f9faSDan Williams	depends on BLK_DEV
16667a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16677b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16689f53f9faSDan Williams	select LIBNVDIMM
1669ec776ef6SChristoph Hellwig	help
1670ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1671ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1672ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1673ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1674ec776ef6SChristoph Hellwig
1675ec776ef6SChristoph Hellwig	  Say Y if unsure.
1676ec776ef6SChristoph Hellwig
1677506f1d07SSam Ravnborgconfig HIGHPTE
1678506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16796fc108a0SJan Beulich	depends on HIGHMEM
1680a7f7f624SMasahiro Yamada	help
1681506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1682506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1683506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1684506f1d07SSam Ravnborg	  entries in high memory.
1685506f1d07SSam Ravnborg
16869f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16879f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1688a7f7f624SMasahiro Yamada	help
16899f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16909f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16919f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16929f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16939f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16949f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16959f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16968c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16979f077871SJeremy Fitzhardinge
16989f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
16999f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17009f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17019f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17029f077871SJeremy Fitzhardinge
17039f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17049f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17059f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17069f077871SJeremy Fitzhardinge	  memory.
17079f077871SJeremy Fitzhardinge
1708c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1709c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1710c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1711c885df50SJeremy Fitzhardinge	default y
1712a7f7f624SMasahiro Yamada	help
1713c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1714c885df50SJeremy Fitzhardinge	  on or off.
1715c885df50SJeremy Fitzhardinge
1716506f1d07SSam Ravnborgconfig MATH_EMULATION
1717506f1d07SSam Ravnborg	bool
1718a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
171987d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1720a7f7f624SMasahiro Yamada	help
1721506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1722506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1723506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1724506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1725506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1726506f1d07SSam Ravnborg	  coprocessor or this emulation.
1727506f1d07SSam Ravnborg
1728506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1729506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1730506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1731506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1732506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1733506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1734506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1735506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1736506f1d07SSam Ravnborg
1737506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1738506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1739506f1d07SSam Ravnborg
1740506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1741506f1d07SSam Ravnborg	  kernel, it won't hurt.
1742506f1d07SSam Ravnborg
1743506f1d07SSam Ravnborgconfig MTRR
17446fc108a0SJan Beulich	def_bool y
17456a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1746a7f7f624SMasahiro Yamada	help
1747506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1748506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1749506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1750506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1751506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1752506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1753506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1754506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1755506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1756506f1d07SSam Ravnborg
1757506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1758506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1759506f1d07SSam Ravnborg	  as well:
1760506f1d07SSam Ravnborg
1761506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1762506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1763506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1764506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1765506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1766506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1767506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1768506f1d07SSam Ravnborg
1769506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1770506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1771506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1772506f1d07SSam Ravnborg
1773506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1774506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1775506f1d07SSam Ravnborg
1776cb1aaebeSMauro Carvalho Chehab	  See <file:Documentation/x86/mtrr.rst> for more information.
1777506f1d07SSam Ravnborg
177895ffa243SYinghai Luconfig MTRR_SANITIZER
17792ffb3501SYinghai Lu	def_bool y
178095ffa243SYinghai Lu	prompt "MTRR cleanup support"
178195ffa243SYinghai Lu	depends on MTRR
1782a7f7f624SMasahiro Yamada	help
1783aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1784aba3728cSThomas Gleixner	  add writeback entries.
178595ffa243SYinghai Lu
1786aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1787692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1788aba3728cSThomas Gleixner	  mtrr_chunk_size.
178995ffa243SYinghai Lu
17902ffb3501SYinghai Lu	  If unsure, say Y.
179195ffa243SYinghai Lu
179295ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1793f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1794f5098d62SYinghai Lu	range 0 1
1795f5098d62SYinghai Lu	default "0"
179695ffa243SYinghai Lu	depends on MTRR_SANITIZER
1797a7f7f624SMasahiro Yamada	help
1798f5098d62SYinghai Lu	  Enable mtrr cleanup default value
179995ffa243SYinghai Lu
180012031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180112031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180212031a62SYinghai Lu	range 0 7
180312031a62SYinghai Lu	default "1"
180412031a62SYinghai Lu	depends on MTRR_SANITIZER
1805a7f7f624SMasahiro Yamada	help
180612031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1807aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180812031a62SYinghai Lu
18092e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18106fc108a0SJan Beulich	def_bool y
18116a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18122a8a2719SIngo Molnar	depends on MTRR
1813a7f7f624SMasahiro Yamada	help
18142e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1815042b78e4SVenki Pallipadi
18162e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18172e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18182e5d9c85Svenkatesh.pallipadi@intel.com
18192e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1820042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18212e5d9c85Svenkatesh.pallipadi@intel.com
18222e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18232e5d9c85Svenkatesh.pallipadi@intel.com
182446cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
182546cf98cdSVenkatesh Pallipadi	def_bool y
182646cf98cdSVenkatesh Pallipadi	depends on X86_PAT
182746cf98cdSVenkatesh Pallipadi
1828628c6246SH. Peter Anvinconfig ARCH_RANDOM
1829628c6246SH. Peter Anvin	def_bool y
1830628c6246SH. Peter Anvin	prompt "x86 architectural random number generator" if EXPERT
1831a7f7f624SMasahiro Yamada	help
1832628c6246SH. Peter Anvin	  Enable the x86 architectural RDRAND instruction
1833628c6246SH. Peter Anvin	  (Intel Bull Mountain technology) to generate random numbers.
1834628c6246SH. Peter Anvin	  If supported, this is a high bandwidth, cryptographically
1835628c6246SH. Peter Anvin	  secure hardware random number generator.
1836628c6246SH. Peter Anvin
183751ae4a2dSH. Peter Anvinconfig X86_SMAP
183851ae4a2dSH. Peter Anvin	def_bool y
183951ae4a2dSH. Peter Anvin	prompt "Supervisor Mode Access Prevention" if EXPERT
1840a7f7f624SMasahiro Yamada	help
184151ae4a2dSH. Peter Anvin	  Supervisor Mode Access Prevention (SMAP) is a security
184251ae4a2dSH. Peter Anvin	  feature in newer Intel processors.  There is a small
184351ae4a2dSH. Peter Anvin	  performance cost if this enabled and turned on; there is
184451ae4a2dSH. Peter Anvin	  also a small increase in the kernel size if this is enabled.
184551ae4a2dSH. Peter Anvin
184651ae4a2dSH. Peter Anvin	  If unsure, say Y.
184751ae4a2dSH. Peter Anvin
1848b971880fSBabu Mogerconfig X86_UMIP
1849796ebc81SRicardo Neri	def_bool y
1850b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1851a7f7f624SMasahiro Yamada	help
1852b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1853b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1854b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1855b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1856b971880fSBabu Moger	  information about the hardware state.
1857796ebc81SRicardo Neri
1858796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1859796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1860796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1861796ebc81SRicardo Neri	  results are dummy.
1862aa35f896SRicardo Neri
186335e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
186438f3e775SBabu Moger	prompt "Memory Protection Keys"
186535e97790SDave Hansen	def_bool y
1866284244a9SDave Hansen	# Note: only available in 64-bit mode
186738f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
186852c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
186952c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1870a7f7f624SMasahiro Yamada	help
1871284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1872284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1873284244a9SDave Hansen	  page tables when an application changes protection domains.
1874284244a9SDave Hansen
18751eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1876284244a9SDave Hansen
1877284244a9SDave Hansen	  If unsure, say y.
187835e97790SDave Hansen
1879db616173SMichal Hockochoice
1880db616173SMichal Hocko	prompt "TSX enable mode"
1881db616173SMichal Hocko	depends on CPU_SUP_INTEL
1882db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1883db616173SMichal Hocko	help
1884db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1885db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1886db616173SMichal Hocko	  can lead to a noticeable performance boost.
1887db616173SMichal Hocko
1888db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1889db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1890db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1891db616173SMichal Hocko
1892db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1893db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1894db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1895db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1896db616173SMichal Hocko	  for the particular machine.
1897db616173SMichal Hocko
1898db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1899db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1900db616173SMichal Hocko	  details.
1901db616173SMichal Hocko
1902db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1903db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1904db616173SMichal Hocko	  relevant.
1905db616173SMichal Hocko
1906db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1907db616173SMichal Hocko	bool "off"
1908db616173SMichal Hocko	help
1909db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1910db616173SMichal Hocko
1911db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1912db616173SMichal Hocko	bool "on"
1913db616173SMichal Hocko	help
1914db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1915db616173SMichal Hocko	  line parameter.
1916db616173SMichal Hocko
1917db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1918db616173SMichal Hocko	bool "auto"
1919db616173SMichal Hocko	help
1920db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1921db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1922db616173SMichal Hockoendchoice
1923db616173SMichal Hocko
1924e7e05452SSean Christophersonconfig X86_SGX
1925e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1926e7e05452SSean Christopherson	depends on X86_64 && CPU_SUP_INTEL
1927e7e05452SSean Christopherson	depends on CRYPTO=y
1928e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1929e7e05452SSean Christopherson	select SRCU
1930e7e05452SSean Christopherson	select MMU_NOTIFIER
1931901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
1932e7e05452SSean Christopherson	help
1933e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1934e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1935e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1936e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1937e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1938e7e05452SSean Christopherson	  hardware.
1939e7e05452SSean Christopherson
1940e7e05452SSean Christopherson	  If unsure, say N.
1941e7e05452SSean Christopherson
1942506f1d07SSam Ravnborgconfig EFI
19439ba16087SJan Beulich	bool "EFI runtime service support"
19445b83683fSHuang, Ying	depends on ACPI
1945f6ce5002SSergey Vlasov	select UCS2_STRING
1946022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
1947a7f7f624SMasahiro Yamada	help
19488b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1949506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1950506f1d07SSam Ravnborg
19518b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19528b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19538b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19548b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19558b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19568b2cb7a8SHuang, Ying	  platforms.
1957506f1d07SSam Ravnborg
1958291f3632SMatt Flemingconfig EFI_STUB
1959291f3632SMatt Fleming	bool "EFI stub support"
1960*c6dbd3e5SPeter Zijlstra	depends on EFI
19618f24f8c2SArd Biesheuvel	depends on $(cc-option,-mabi=ms) || X86_32
19627b2a583aSMatt Fleming	select RELOCATABLE
1963a7f7f624SMasahiro Yamada	help
1964291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1965291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1966291f3632SMatt Fleming
19674f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19680c759662SMatt Fleming
19697d453eeeSMatt Flemingconfig EFI_MIXED
19707d453eeeSMatt Fleming	bool "EFI mixed-mode support"
19717d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
1972a7f7f624SMasahiro Yamada	help
19737d453eeeSMatt Fleming	   Enabling this feature allows a 64-bit kernel to be booted
19747d453eeeSMatt Fleming	   on a 32-bit firmware, provided that your CPU supports 64-bit
19757d453eeeSMatt Fleming	   mode.
19767d453eeeSMatt Fleming
19777d453eeeSMatt Fleming	   Note that it is not possible to boot a mixed-mode enabled
19787d453eeeSMatt Fleming	   kernel via the EFI boot stub - a bootloader that supports
19797d453eeeSMatt Fleming	   the EFI handover protocol must be used.
19807d453eeeSMatt Fleming
19817d453eeeSMatt Fleming	   If unsure, say N.
19827d453eeeSMatt Fleming
19838636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
1984506f1d07SSam Ravnborg
1985506f1d07SSam Ravnborgconfig KEXEC
1986506f1d07SSam Ravnborg	bool "kexec system call"
19872965faa5SDave Young	select KEXEC_CORE
1988a7f7f624SMasahiro Yamada	help
1989506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
1990506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
1991506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
1992506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
1993506f1d07SSam Ravnborg
1994506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
1995506f1d07SSam Ravnborg
1996506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
1997506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
1998bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
1999bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2000bf220695SGeert Uytterhoeven	  made.
2001506f1d07SSam Ravnborg
200274ca317cSVivek Goyalconfig KEXEC_FILE
200374ca317cSVivek Goyal	bool "kexec file based system call"
20042965faa5SDave Young	select KEXEC_CORE
200574ca317cSVivek Goyal	select BUILD_BIN2C
200674ca317cSVivek Goyal	depends on X86_64
200774ca317cSVivek Goyal	depends on CRYPTO=y
200874ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2009a7f7f624SMasahiro Yamada	help
201074ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
201174ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
201274ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
201374ca317cSVivek Goyal	  accepted by previous system call.
201474ca317cSVivek Goyal
2015b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2016b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2017b799a09fSAKASHI Takahiro
201899d5cadfSJiri Bohacconfig KEXEC_SIG
20198e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
202074ca317cSVivek Goyal	depends on KEXEC_FILE
2021a7f7f624SMasahiro Yamada	help
202299d5cadfSJiri Bohac
202399d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
202499d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
202599d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
202699d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
202799d5cadfSJiri Bohac
202899d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
202999d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
203099d5cadfSJiri Bohac	  loaded in order for this to work.
203199d5cadfSJiri Bohac
203299d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
203399d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
203499d5cadfSJiri Bohac	depends on KEXEC_SIG
2035a7f7f624SMasahiro Yamada	help
20368e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2037d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20388e7d8381SVivek Goyal
20398e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
20408e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
204199d5cadfSJiri Bohac	depends on KEXEC_SIG
20428e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
20438e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2044a7f7f624SMasahiro Yamada	help
20458e7d8381SVivek Goyal	  Enable bzImage signature verification support.
20468e7d8381SVivek Goyal
2047506f1d07SSam Ravnborgconfig CRASH_DUMP
204804b69447SPavel Machek	bool "kernel crash dumps"
2049506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2050a7f7f624SMasahiro Yamada	help
2051506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2052506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2053506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2054506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2055506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2056506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2057506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2058506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2059330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2060506f1d07SSam Ravnborg
20613ab83521SHuang Yingconfig KEXEC_JUMP
20626ea30386SKees Cook	bool "kexec jump"
2063fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2064a7f7f624SMasahiro Yamada	help
206589081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
206689081d17SHuang Ying	  code in physical address mode via KEXEC
20673ab83521SHuang Ying
2068506f1d07SSam Ravnborgconfig PHYSICAL_START
20696a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2070ceefccc9SH. Peter Anvin	default "0x1000000"
2071a7f7f624SMasahiro Yamada	help
2072506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2073506f1d07SSam Ravnborg
2074506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2075506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2076506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2077506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2078506f1d07SSam Ravnborg	  address.
2079506f1d07SSam Ravnborg
2080506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2081506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2082506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2083506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2084506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2085506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2086506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2087506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2088506f1d07SSam Ravnborg
2089ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2090ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2091ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2092ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2093ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2094ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2095ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2096330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2097ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2098506f1d07SSam Ravnborg
2099506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2100506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2101506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2102506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2103506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2104506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2105506f1d07SSam Ravnborg	  line.
2106506f1d07SSam Ravnborg
2107506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2108506f1d07SSam Ravnborg
2109506f1d07SSam Ravnborgconfig RELOCATABLE
211026717808SH. Peter Anvin	bool "Build a relocatable kernel"
211126717808SH. Peter Anvin	default y
2112a7f7f624SMasahiro Yamada	help
2113506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2114506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2115506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2116506f1d07SSam Ravnborg	  but are discarded at runtime.
2117506f1d07SSam Ravnborg
2118506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2119506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2120506f1d07SSam Ravnborg	  kernel.
2121506f1d07SSam Ravnborg
2122506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2123506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21248ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2125506f1d07SSam Ravnborg
21268ab3820fSKees Cookconfig RANDOMIZE_BASE
2127e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21288ab3820fSKees Cook	depends on RELOCATABLE
21296807c846SIngo Molnar	default y
2130a7f7f624SMasahiro Yamada	help
2131e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2132e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2133e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2134e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2135e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2136e8581e3dSBaoquan He	  code internals.
2137e8581e3dSBaoquan He
2138ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2139ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2140ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2141ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2142ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2143ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2144ed9f007eSKees Cook
2145ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2146ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2147ed9f007eSKees Cook	  512MB (8 bits of entropy).
21488ab3820fSKees Cook
2149a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2150e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2151e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2152ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2153ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2154ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2155ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2156ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2157ed9f007eSKees Cook	  limited due to memory layouts.
2158e8581e3dSBaoquan He
21596807c846SIngo Molnar	  If unsure, say Y.
2160da2b6fb9SKees Cook
21618ab3820fSKees Cook# Relocation on x86 needs some additional build support
2162845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2163845adf72SH. Peter Anvin	def_bool y
21648ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2165845adf72SH. Peter Anvin
2166506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2167a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
21688ab3820fSKees Cook	default "0x200000"
2169a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2170a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2171a7f7f624SMasahiro Yamada	help
2172506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2173506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2174506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2175506f1d07SSam Ravnborg
2176506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2177506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2178506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2179506f1d07SSam Ravnborg
2180506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2181506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2182506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2183506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2184506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2185506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2186506f1d07SSam Ravnborg	  above alignment restrictions.
2187506f1d07SSam Ravnborg
2188a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2189a0215061SKees Cook	  this value must be a multiple of 0x200000.
2190a0215061SKees Cook
2191506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2192506f1d07SSam Ravnborg
2193eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2194eedb92abSKirill A. Shutemov	bool
2195a7f7f624SMasahiro Yamada	help
2196eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2197eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2198eedb92abSKirill A. Shutemov
21990483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22000483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22010483e1faSThomas Garnier	depends on X86_64
22020483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2203eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22040483e1faSThomas Garnier	default RANDOMIZE_BASE
2205a7f7f624SMasahiro Yamada	help
22060483e1faSThomas Garnier	   Randomizes the base virtual address of kernel memory sections
22070483e1faSThomas Garnier	   (physical memory mapping, vmalloc & vmemmap). This security feature
22080483e1faSThomas Garnier	   makes exploits relying on predictable memory locations less reliable.
22090483e1faSThomas Garnier
22100483e1faSThomas Garnier	   The order of allocations remains unchanged. Entropy is generated in
22110483e1faSThomas Garnier	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
22120483e1faSThomas Garnier	   configuration have in average 30,000 different possible virtual
22130483e1faSThomas Garnier	   addresses for each memory section.
22140483e1faSThomas Garnier
22156807c846SIngo Molnar	   If unsure, say Y.
22160483e1faSThomas Garnier
221790397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
221890397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
221990397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
222090397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
222190397a41SThomas Garnier	default "0x0"
222290397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
222390397a41SThomas Garnier	range 0x0 0x40
2224a7f7f624SMasahiro Yamada	help
222590397a41SThomas Garnier	   Define the padding in terabytes added to the existing physical
222690397a41SThomas Garnier	   memory size during kernel memory randomization. It is useful
222790397a41SThomas Garnier	   for memory hotplug support but reduces the entropy available for
222890397a41SThomas Garnier	   address randomization.
222990397a41SThomas Garnier
223090397a41SThomas Garnier	   If unsure, leave at the default value.
223190397a41SThomas Garnier
2232506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2233bebd024eSThomas Gleixner	def_bool y
223440b31360SStephen Rothwell	depends on SMP
2235506f1d07SSam Ravnborg
223680aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
223780aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22382c922cd0SKees Cook	depends on HOTPLUG_CPU
2239a7f7f624SMasahiro Yamada	help
224080aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
224180aa1dffSFenghua Yu
224280aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
224380aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
224480aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
224580aa1dffSFenghua Yu
224680aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
224780aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
224880aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
224980aa1dffSFenghua Yu
225080aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
225180aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
225280aa1dffSFenghua Yu
225380aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
225480aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
225580aa1dffSFenghua Yu	  be other CPU0 dependencies.
225680aa1dffSFenghua Yu
225780aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
225880aa1dffSFenghua Yu	  you enable this feature.
225980aa1dffSFenghua Yu
226080aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
226180aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
226280aa1dffSFenghua Yu	  parameter cpu0_hotplug.
226380aa1dffSFenghua Yu
2264a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2265a71c8bc5SFenghua Yu	def_bool n
2266a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
22672c922cd0SKees Cook	depends on HOTPLUG_CPU
2268a7f7f624SMasahiro Yamada	help
2269a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2270a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2271a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2272a71c8bc5SFenghua Yu
2273a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2274a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2275a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2276a71c8bc5SFenghua Yu
2277a71c8bc5SFenghua Yu	  If unsure, say N.
2278a71c8bc5SFenghua Yu
2279506f1d07SSam Ravnborgconfig COMPAT_VDSO
2280b0b49f26SAndy Lutomirski	def_bool n
2281b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2282953fee1dSIngo Molnar	depends on COMPAT_32
2283a7f7f624SMasahiro Yamada	help
2284b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2285b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2286b0b49f26SAndy Lutomirski	  indicated in its segment table.
2287e84446deSRandy Dunlap
2288b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2289b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2290b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2291b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2292b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2293506f1d07SSam Ravnborg
2294b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2295b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2296b0b49f26SAndy Lutomirski
2297b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2298b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2299b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2300b0b49f26SAndy Lutomirski
2301b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2302b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2303506f1d07SSam Ravnborg
23043dc33bd3SKees Cookchoice
23053dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23063dc33bd3SKees Cook	depends on X86_64
2307625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23083dc33bd3SKees Cook	help
23093dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23103dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23113dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23123dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23133dc33bd3SKees Cook
23143dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2315bd49e16eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].
23163dc33bd3SKees Cook
23173dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23183dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23193dc33bd3SKees Cook	  to improve security.
23203dc33bd3SKees Cook
2321bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23223dc33bd3SKees Cook
23233dc33bd3SKees Cook	config LEGACY_VSYSCALL_EMULATE
2324bd49e16eSAndy Lutomirski		bool "Full emulation"
23253dc33bd3SKees Cook		help
2326bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2327bd49e16eSAndy Lutomirski		  address mapping. This makes the mapping non-executable, but
2328bd49e16eSAndy Lutomirski		  it still contains readable known contents, which could be
2329bd49e16eSAndy Lutomirski		  used in certain rare security vulnerability exploits. This
2330bd49e16eSAndy Lutomirski		  configuration is recommended when using legacy userspace
2331bd49e16eSAndy Lutomirski		  that still uses vsyscalls along with legacy binary
2332bd49e16eSAndy Lutomirski		  instrumentation tools that require code to be readable.
2333bd49e16eSAndy Lutomirski
2334bd49e16eSAndy Lutomirski		  An example of this type of legacy userspace is running
2335bd49e16eSAndy Lutomirski		  Pin on an old binary that still uses vsyscalls.
2336bd49e16eSAndy Lutomirski
2337bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2338bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2339bd49e16eSAndy Lutomirski		help
2340bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2341bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2342bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2343bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2344bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2345bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2346bd49e16eSAndy Lutomirski		  buffer.
23473dc33bd3SKees Cook
23483dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23493dc33bd3SKees Cook		bool "None"
23503dc33bd3SKees Cook		help
23513dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
23523dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
23533dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
23543dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
23553dc33bd3SKees Cook		  malicious userspace programs can be identified.
23563dc33bd3SKees Cook
23573dc33bd3SKees Cookendchoice
23583dc33bd3SKees Cook
2359516cbf37STim Birdconfig CMDLINE_BOOL
2360516cbf37STim Bird	bool "Built-in kernel command line"
2361a7f7f624SMasahiro Yamada	help
2362516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2363516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2364516cbf37STim Bird	  necessary or convenient to provide some or all of the
2365516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2366516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2367516cbf37STim Bird
2368516cbf37STim Bird	  To compile command line arguments into the kernel,
2369516cbf37STim Bird	  set this option to 'Y', then fill in the
237069711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2371516cbf37STim Bird
2372516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2373516cbf37STim Bird	  should leave this option set to 'N'.
2374516cbf37STim Bird
2375516cbf37STim Birdconfig CMDLINE
2376516cbf37STim Bird	string "Built-in kernel command string"
2377516cbf37STim Bird	depends on CMDLINE_BOOL
2378516cbf37STim Bird	default ""
2379a7f7f624SMasahiro Yamada	help
2380516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2381516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2382516cbf37STim Bird	  command line at boot time, it is appended to this string to
2383516cbf37STim Bird	  form the full kernel command line, when the system boots.
2384516cbf37STim Bird
2385516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2386516cbf37STim Bird	  change this behavior.
2387516cbf37STim Bird
2388516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2389516cbf37STim Bird	  by the boot loader) should specify the device for the root
2390516cbf37STim Bird	  file system.
2391516cbf37STim Bird
2392516cbf37STim Birdconfig CMDLINE_OVERRIDE
2393516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2394645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2395a7f7f624SMasahiro Yamada	help
2396516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2397516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2398516cbf37STim Bird
2399516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2400516cbf37STim Bird	  be set to 'N' under normal conditions.
2401516cbf37STim Bird
2402a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2403a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2404a5b9e5a2SAndy Lutomirski	default y
2405a7f7f624SMasahiro Yamada	help
2406a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2407a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2408a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2409a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2410a5b9e5a2SAndy Lutomirski	  threading libraries.
2411a5b9e5a2SAndy Lutomirski
2412a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2413a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2414a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2415a5b9e5a2SAndy Lutomirski
2416a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2417a5b9e5a2SAndy Lutomirski
24183aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24193aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24203aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24213aac3ebeSThomas Gleixner	help
24223aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24233aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24243aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24253aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24263aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24273aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24283aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24293aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24303aac3ebeSThomas Gleixner	  never get a signal delivered.
24313aac3ebeSThomas Gleixner
24323aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24333aac3ebeSThomas Gleixner
2434b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2435b700e7f0SSeth Jennings
2436506f1d07SSam Ravnborgendmenu
2437506f1d07SSam Ravnborg
24383072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
24393072e413SMichal Hocko	def_bool y
24405c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
24413072e413SMichal Hocko
2442f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2443f91ef222SOscar Salvador	def_bool y
2444f91ef222SOscar Salvador
2445e534c7c5SLee Schermerhornconfig USE_PERCPU_NUMA_NODE_ID
2446645a7919STejun Heo	def_bool y
2447e534c7c5SLee Schermerhorn	depends on NUMA
2448e534c7c5SLee Schermerhorn
2449da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2450e279b6c1SSam Ravnborg
2451e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
24523c2362e6SHarvey Harrison	def_bool y
245344556530SZhimin Gu	depends on HIBERNATION
2454e279b6c1SSam Ravnborg
2455e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2456e279b6c1SSam Ravnborg
2457e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2458e279b6c1SSam Ravnborg
2459a6b68076SAndi Kleenconfig X86_APM_BOOT
24606fc108a0SJan Beulich	def_bool y
2461282e5aabSPaul Bolle	depends on APM
2462a6b68076SAndi Kleen
2463e279b6c1SSam Ravnborgmenuconfig APM
2464e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2465efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2466a7f7f624SMasahiro Yamada	help
2467e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2468e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2469e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2470e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2471e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2472e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2473e279b6c1SSam Ravnborg
2474e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2475e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2476e279b6c1SSam Ravnborg
2477e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2478e279b6c1SSam Ravnborg	  machines with more than one CPU.
2479e279b6c1SSam Ravnborg
2480e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2481151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
24822dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2483e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2484e279b6c1SSam Ravnborg
2485e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2486e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2487e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2488e279b6c1SSam Ravnborg
2489e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2490e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2491e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2492e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2493e279b6c1SSam Ravnborg
2494e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2495e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2496e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2497e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2498e279b6c1SSam Ravnborg	  APM in your BIOS).
2499e279b6c1SSam Ravnborg
2500e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2501e279b6c1SSam Ravnborg	  "weird" problems:
2502e279b6c1SSam Ravnborg
2503e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2504e279b6c1SSam Ravnborg	  enabled.
2505e279b6c1SSam Ravnborg	  2) pass the "no-hlt" option to the kernel
2506e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2507e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2508e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2509e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2510e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2511e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2512e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2513e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2514e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2515e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2516e279b6c1SSam Ravnborg	  11) exchange RAM chips
2517e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2518e279b6c1SSam Ravnborg
2519e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2520e279b6c1SSam Ravnborg	  module will be called apm.
2521e279b6c1SSam Ravnborg
2522e279b6c1SSam Ravnborgif APM
2523e279b6c1SSam Ravnborg
2524e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2525e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2526a7f7f624SMasahiro Yamada	help
2527e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2528e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2529e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2530e279b6c1SSam Ravnborg
2531e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2532e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2533a7f7f624SMasahiro Yamada	help
2534e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2535e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2536e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2537e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2538e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2539e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2540e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2541e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2542e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2543e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2544e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2545e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2546e279b6c1SSam Ravnborg	  this feature.
2547e279b6c1SSam Ravnborg
2548e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2549dd8af076SLen Brown	depends on CPU_IDLE
2550e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2551a7f7f624SMasahiro Yamada	help
2552e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2553e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2554e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2555e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2556e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2557e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2558e279b6c1SSam Ravnborg	  this option does nothing.)
2559e279b6c1SSam Ravnborg
2560e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2561e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2562a7f7f624SMasahiro Yamada	help
2563e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2564e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2565e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2566e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2567e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2568e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2569e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2570e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2571e279b6c1SSam Ravnborg	  especially if you are using gpm.
2572e279b6c1SSam Ravnborg
2573e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2574e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2575a7f7f624SMasahiro Yamada	help
2576e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2577e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2578e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2579e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2580e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2581e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2582e279b6c1SSam Ravnborg
2583e279b6c1SSam Ravnborgendif # APM
2584e279b6c1SSam Ravnborg
2585bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2586e279b6c1SSam Ravnborg
2587e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2588e279b6c1SSam Ravnborg
258927471fdbSAndy Henroidsource "drivers/idle/Kconfig"
259027471fdbSAndy Henroid
2591e279b6c1SSam Ravnborgendmenu
2592e279b6c1SSam Ravnborg
2593e279b6c1SSam Ravnborg
2594e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2595e279b6c1SSam Ravnborg
2596e279b6c1SSam Ravnborgchoice
2597e279b6c1SSam Ravnborg	prompt "PCI access mode"
2598efefa6f6SIngo Molnar	depends on X86_32 && PCI
2599e279b6c1SSam Ravnborg	default PCI_GOANY
2600a7f7f624SMasahiro Yamada	help
2601e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2602e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2603e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2604e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2605e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2606e279b6c1SSam Ravnborg
2607e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2608e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2609e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2610e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2611e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2612e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2613e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2614e279b6c1SSam Ravnborg
2615e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2616e279b6c1SSam Ravnborg	bool "BIOS"
2617e279b6c1SSam Ravnborg
2618e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2619e279b6c1SSam Ravnborg	bool "MMConfig"
2620e279b6c1SSam Ravnborg
2621e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2622e279b6c1SSam Ravnborg	bool "Direct"
2623e279b6c1SSam Ravnborg
26243ef0e1f8SAndres Salomonconfig PCI_GOOLPC
262576fb6570SDaniel Drake	bool "OLPC XO-1"
26263ef0e1f8SAndres Salomon	depends on OLPC
26273ef0e1f8SAndres Salomon
26282bdd1b03SAndres Salomonconfig PCI_GOANY
26292bdd1b03SAndres Salomon	bool "Any"
26302bdd1b03SAndres Salomon
2631e279b6c1SSam Ravnborgendchoice
2632e279b6c1SSam Ravnborg
2633e279b6c1SSam Ravnborgconfig PCI_BIOS
26343c2362e6SHarvey Harrison	def_bool y
2635efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2636e279b6c1SSam Ravnborg
2637e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2638e279b6c1SSam Ravnborgconfig PCI_DIRECT
26393c2362e6SHarvey Harrison	def_bool y
26400aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2641e279b6c1SSam Ravnborg
2642e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2643b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2644b45c9f36SJan Kiszka	default y
26454590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2646b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2647e279b6c1SSam Ravnborg
26483ef0e1f8SAndres Salomonconfig PCI_OLPC
26492bdd1b03SAndres Salomon	def_bool y
26502bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
26513ef0e1f8SAndres Salomon
2652b5401a96SAlex Nixonconfig PCI_XEN
2653b5401a96SAlex Nixon	def_bool y
2654b5401a96SAlex Nixon	depends on PCI && XEN
2655b5401a96SAlex Nixon
26568364e1f8SJan Kiszkaconfig MMCONF_FAM10H
26578364e1f8SJan Kiszka	def_bool y
26588364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2659e279b6c1SSam Ravnborg
26603f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
26616a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
26626ea30386SKees Cook	depends on PCI
26633f6ea84aSIra W. Snyder	help
26643f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
26653f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
26663f6ea84aSIra W. Snyder	  not have ACPI.
26673f6ea84aSIra W. Snyder
266864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
266964a5fed6SBjorn Helgaas	  is known to be incomplete.
267064a5fed6SBjorn Helgaas
267164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
267264a5fed6SBjorn Helgaas
26733a495511SWilliam Breathitt Grayconfig ISA_BUS
267417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
26753a495511SWilliam Breathitt Gray	help
267617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
267717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
267817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
267917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
268017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
26813a495511SWilliam Breathitt Gray
26823a495511SWilliam Breathitt Gray	  If unsure, say N.
26833a495511SWilliam Breathitt Gray
26841c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2685e279b6c1SSam Ravnborgconfig ISA_DMA_API
26861c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
26871c00f016SDavid Rientjes	default y
26881c00f016SDavid Rientjes	help
26891c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
26901c00f016SDavid Rientjes	  If unsure, say Y.
2691e279b6c1SSam Ravnborg
269251e68d05SLinus Torvaldsif X86_32
269351e68d05SLinus Torvalds
2694e279b6c1SSam Ravnborgconfig ISA
2695e279b6c1SSam Ravnborg	bool "ISA support"
2696a7f7f624SMasahiro Yamada	help
2697e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2698e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2699e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2700e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2701e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2702e279b6c1SSam Ravnborg
2703e279b6c1SSam Ravnborgconfig SCx200
2704e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2705a7f7f624SMasahiro Yamada	help
2706e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2707e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2708e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2709e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2710e279b6c1SSam Ravnborg
2711e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2712e279b6c1SSam Ravnborg
2713e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2714e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2715592913ecSJohn Stultz	depends on SCx200
2716e279b6c1SSam Ravnborg	default y
2717a7f7f624SMasahiro Yamada	help
2718e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2719e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2720e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2721e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2722e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2723e279b6c1SSam Ravnborg
27243ef0e1f8SAndres Salomonconfig OLPC
27253ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
272654008979SThomas Gleixner	depends on !X86_PAE
27273c554946SAndres Salomon	select GPIOLIB
2728dc3119e7SThomas Gleixner	select OF
272945bb1674SDaniel Drake	select OF_PROMTREE
2730b4e51854SGrant Likely	select IRQ_DOMAIN
27310c3d931bSLubomir Rintel	select OLPC_EC
2732a7f7f624SMasahiro Yamada	help
27333ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
27343ef0e1f8SAndres Salomon	  XO hardware.
27353ef0e1f8SAndres Salomon
2736a3128588SDaniel Drakeconfig OLPC_XO1_PM
2737a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2738fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2739a7f7f624SMasahiro Yamada	help
274097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2741bf1ebf00SDaniel Drake
2742cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2743cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2744cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2745a7f7f624SMasahiro Yamada	help
2746cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2747cfee9597SDaniel Drake	  programmable wakeup source.
2748cfee9597SDaniel Drake
27497feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
27507feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
275192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2752ed8e47feSRandy Dunlap	depends on INPUT=y
2753d8d01a63SDaniel Drake	select POWER_SUPPLY
2754a7f7f624SMasahiro Yamada	help
27557feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
27567bc74b3dSDaniel Drake	   - EC-driven system wakeups
27577feda8e9SDaniel Drake	   - Power button
27587bc74b3dSDaniel Drake	   - Ebook switch
27592cf2baeaSDaniel Drake	   - Lid switch
2760e1040ac6SDaniel Drake	   - AC adapter status updates
2761e1040ac6SDaniel Drake	   - Battery status updates
27627feda8e9SDaniel Drake
2763a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2764a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2765d8d01a63SDaniel Drake	depends on OLPC && ACPI
2766d8d01a63SDaniel Drake	select POWER_SUPPLY
2767a7f7f624SMasahiro Yamada	help
2768a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2769a0f30f59SDaniel Drake	   - EC-driven system wakeups
2770a0f30f59SDaniel Drake	   - AC adapter status updates
2771a0f30f59SDaniel Drake	   - Battery status updates
2772e279b6c1SSam Ravnborg
2773d4f3e350SEd Wildgooseconfig ALIX
2774d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2775d4f3e350SEd Wildgoose	select GPIOLIB
2776a7f7f624SMasahiro Yamada	help
2777d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2778d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2779d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2780d4f3e350SEd Wildgoose	  get added here.
2781d4f3e350SEd Wildgoose
2782d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2783d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2784d4f3e350SEd Wildgoose
2785d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2786d4f3e350SEd Wildgoose
2787da4e3302SPhilip Prindevilleconfig NET5501
2788da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2789da4e3302SPhilip Prindeville	select GPIOLIB
2790a7f7f624SMasahiro Yamada	help
2791da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2792da4e3302SPhilip Prindeville
27933197059aSPhilip A. Prindevilleconfig GEOS
27943197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
27953197059aSPhilip A. Prindeville	select GPIOLIB
27963197059aSPhilip A. Prindeville	depends on DMI
2797a7f7f624SMasahiro Yamada	help
27983197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
27993197059aSPhilip A. Prindeville
28007d029125SVivien Didelotconfig TS5500
28017d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
28027d029125SVivien Didelot	depends on MELAN
28037d029125SVivien Didelot	select CHECK_SIGNATURE
28047d029125SVivien Didelot	select NEW_LEDS
28057d029125SVivien Didelot	select LEDS_CLASS
2806a7f7f624SMasahiro Yamada	help
28077d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
28087d029125SVivien Didelot
2809e279b6c1SSam Ravnborgendif # X86_32
2810e279b6c1SSam Ravnborg
281123ac4ae8SAndreas Herrmannconfig AMD_NB
2812e279b6c1SSam Ravnborg	def_bool y
28130e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
2814e279b6c1SSam Ravnborg
2815e279b6c1SSam Ravnborgendmenu
2816e279b6c1SSam Ravnborg
2817e279b6c1SSam Ravnborg
28181572497cSChristoph Hellwigmenu "Binary Emulations"
2819e279b6c1SSam Ravnborg
2820e279b6c1SSam Ravnborgconfig IA32_EMULATION
2821e279b6c1SSam Ravnborg	bool "IA32 Emulation"
2822e279b6c1SSam Ravnborg	depends on X86_64
282339f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
2824d1603990SRandy Dunlap	select BINFMT_ELF
282539f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
2826a7f7f624SMasahiro Yamada	help
28275fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
28285fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
28295fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
2830e279b6c1SSam Ravnborg
2831e279b6c1SSam Ravnborgconfig IA32_AOUT
2832e279b6c1SSam Ravnborg	tristate "IA32 a.out support"
28336b213e1bSDavid Woodhouse	depends on IA32_EMULATION
2834eac61655SBorislav Petkov	depends on BROKEN
2835a7f7f624SMasahiro Yamada	help
2836e279b6c1SSam Ravnborg	  Support old a.out binaries in the 32bit emulation.
2837e279b6c1SSam Ravnborg
28380bf62763SH. Peter Anvinconfig X86_X32
28396ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
28409b54050bSBrian Gerst	depends on X86_64
2841a7f7f624SMasahiro Yamada	help
28425fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
28435fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
28445fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
28455fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
28465fd92e65SH. J. Lu
28475fd92e65SH. J. Lu	  You will need a recent binutils (2.22 or later) with
28485fd92e65SH. J. Lu	  elf32_x86_64 support enabled to compile a kernel with this
28495fd92e65SH. J. Lu	  option set.
28505fd92e65SH. J. Lu
2851953fee1dSIngo Molnarconfig COMPAT_32
2852953fee1dSIngo Molnar	def_bool y
2853953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
2854953fee1dSIngo Molnar	select HAVE_UID16
2855953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
2856953fee1dSIngo Molnar
2857e279b6c1SSam Ravnborgconfig COMPAT
28583c2362e6SHarvey Harrison	def_bool y
28590bf62763SH. Peter Anvin	depends on IA32_EMULATION || X86_X32
2860e279b6c1SSam Ravnborg
28613120e25eSJan Beulichif COMPAT
2862e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
28633120e25eSJan Beulich	def_bool y
2864e279b6c1SSam Ravnborg
2865e279b6c1SSam Ravnborgconfig SYSVIPC_COMPAT
28663c2362e6SHarvey Harrison	def_bool y
28673120e25eSJan Beulich	depends on SYSVIPC
28683120e25eSJan Beulichendif
2869ee009e4aSDavid Howells
2870e279b6c1SSam Ravnborgendmenu
2871e279b6c1SSam Ravnborg
2872e279b6c1SSam Ravnborg
2873e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
2874e5beae16SKeith Packard	def_bool y
2875e5beae16SKeith Packard	depends on X86_32
2876e5beae16SKeith Packard
2877edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
28785e8ebd84SJason A. Donenfeld
28795e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
2880