xref: /openbmc/linux/arch/x86/Kconfig (revision b593bce5)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_DEBUG_STACKOVERFLOW
18	select MODULES_USE_ELF_REL
19	select OLD_SIGACTION
20	select GENERIC_VDSO_32
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select ARCH_HAS_SYSCALL_WRAPPER
34
35config FORCE_DYNAMIC_FTRACE
36	def_bool y
37	depends on X86_32
38	depends on FUNCTION_TRACER
39	select DYNAMIC_FTRACE
40	help
41	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42	 in order to test the non static function tracing in the
43	 generic code, as other architectures still use it. But we
44	 only need to keep it around for x86_64. No need to keep it
45	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46#
47# Arch settings
48#
49# ( Note that options that are marked 'if X86_64' could in principle be
50#   ported to 32-bit as well. )
51#
52config X86
53	def_bool y
54	#
55	# Note: keep this list sorted alphabetically
56	#
57	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
58	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59	select ARCH_32BIT_OFF_T			if X86_32
60	select ARCH_CLOCKSOURCE_DATA
61	select ARCH_CLOCKSOURCE_INIT
62	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63	select ARCH_HAS_DEBUG_VIRTUAL
64	select ARCH_HAS_DEVMEM_IS_ALLOWED
65	select ARCH_HAS_ELF_RANDOMIZE
66	select ARCH_HAS_FAST_MULTIPLIER
67	select ARCH_HAS_FILTER_PGPROT
68	select ARCH_HAS_FORTIFY_SOURCE
69	select ARCH_HAS_GCOV_PROFILE_ALL
70	select ARCH_HAS_KCOV			if X86_64
71	select ARCH_HAS_MEMBARRIER_SYNC_CORE
72	select ARCH_HAS_PMEM_API		if X86_64
73	select ARCH_HAS_PTE_DEVMAP		if X86_64
74	select ARCH_HAS_PTE_SPECIAL
75	select ARCH_HAS_REFCOUNT
76	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
77	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
78	select ARCH_HAS_SET_MEMORY
79	select ARCH_HAS_SET_DIRECT_MAP
80	select ARCH_HAS_STRICT_KERNEL_RWX
81	select ARCH_HAS_STRICT_MODULE_RWX
82	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
83	select ARCH_HAS_UBSAN_SANITIZE_ALL
84	select ARCH_HAVE_NMI_SAFE_CMPXCHG
85	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
86	select ARCH_MIGHT_HAVE_PC_PARPORT
87	select ARCH_MIGHT_HAVE_PC_SERIO
88	select ARCH_STACKWALK
89	select ARCH_SUPPORTS_ACPI
90	select ARCH_SUPPORTS_ATOMIC_RMW
91	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
92	select ARCH_USE_BUILTIN_BSWAP
93	select ARCH_USE_QUEUED_RWLOCKS
94	select ARCH_USE_QUEUED_SPINLOCKS
95	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
96	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
97	select ARCH_WANT_HUGE_PMD_SHARE
98	select ARCH_WANTS_THP_SWAP		if X86_64
99	select BUILDTIME_EXTABLE_SORT
100	select CLKEVT_I8253
101	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
102	select CLOCKSOURCE_WATCHDOG
103	select DCACHE_WORD_ACCESS
104	select EDAC_ATOMIC_SCRUB
105	select EDAC_SUPPORT
106	select GENERIC_CLOCKEVENTS
107	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
108	select GENERIC_CLOCKEVENTS_MIN_ADJUST
109	select GENERIC_CMOS_UPDATE
110	select GENERIC_CPU_AUTOPROBE
111	select GENERIC_CPU_VULNERABILITIES
112	select GENERIC_EARLY_IOREMAP
113	select GENERIC_FIND_FIRST_BIT
114	select GENERIC_IOMAP
115	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
116	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
117	select GENERIC_IRQ_MIGRATION		if SMP
118	select GENERIC_IRQ_PROBE
119	select GENERIC_IRQ_RESERVATION_MODE
120	select GENERIC_IRQ_SHOW
121	select GENERIC_PENDING_IRQ		if SMP
122	select GENERIC_SMP_IDLE_THREAD
123	select GENERIC_STRNCPY_FROM_USER
124	select GENERIC_STRNLEN_USER
125	select GENERIC_TIME_VSYSCALL
126	select GENERIC_GETTIMEOFDAY
127	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
128	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
129	select HAVE_ACPI_APEI			if ACPI
130	select HAVE_ACPI_APEI_NMI		if ACPI
131	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
132	select HAVE_ARCH_AUDITSYSCALL
133	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
134	select HAVE_ARCH_JUMP_LABEL
135	select HAVE_ARCH_JUMP_LABEL_RELATIVE
136	select HAVE_ARCH_KASAN			if X86_64
137	select HAVE_ARCH_KGDB
138	select HAVE_ARCH_MMAP_RND_BITS		if MMU
139	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
140	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
141	select HAVE_ARCH_PREL32_RELOCATIONS
142	select HAVE_ARCH_SECCOMP_FILTER
143	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
144	select HAVE_ARCH_STACKLEAK
145	select HAVE_ARCH_TRACEHOOK
146	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
147	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
148	select HAVE_ARCH_VMAP_STACK		if X86_64
149	select HAVE_ARCH_WITHIN_STACK_FRAMES
150	select HAVE_CMPXCHG_DOUBLE
151	select HAVE_CMPXCHG_LOCAL
152	select HAVE_CONTEXT_TRACKING		if X86_64
153	select HAVE_COPY_THREAD_TLS
154	select HAVE_C_RECORDMCOUNT
155	select HAVE_DEBUG_KMEMLEAK
156	select HAVE_DMA_CONTIGUOUS
157	select HAVE_DYNAMIC_FTRACE
158	select HAVE_DYNAMIC_FTRACE_WITH_REGS
159	select HAVE_EBPF_JIT
160	select HAVE_EFFICIENT_UNALIGNED_ACCESS
161	select HAVE_EISA
162	select HAVE_EXIT_THREAD
163	select HAVE_FAST_GUP
164	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
165	select HAVE_FTRACE_MCOUNT_RECORD
166	select HAVE_FUNCTION_GRAPH_TRACER
167	select HAVE_FUNCTION_TRACER
168	select HAVE_GCC_PLUGINS
169	select HAVE_HW_BREAKPOINT
170	select HAVE_IDE
171	select HAVE_IOREMAP_PROT
172	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
173	select HAVE_IRQ_TIME_ACCOUNTING
174	select HAVE_KERNEL_BZIP2
175	select HAVE_KERNEL_GZIP
176	select HAVE_KERNEL_LZ4
177	select HAVE_KERNEL_LZMA
178	select HAVE_KERNEL_LZO
179	select HAVE_KERNEL_XZ
180	select HAVE_KPROBES
181	select HAVE_KPROBES_ON_FTRACE
182	select HAVE_FUNCTION_ERROR_INJECTION
183	select HAVE_KRETPROBES
184	select HAVE_KVM
185	select HAVE_LIVEPATCH			if X86_64
186	select HAVE_MEMBLOCK_NODE_MAP
187	select HAVE_MIXED_BREAKPOINTS_REGS
188	select HAVE_MOD_ARCH_SPECIFIC
189	select HAVE_MOVE_PMD
190	select HAVE_NMI
191	select HAVE_OPROFILE
192	select HAVE_OPTPROBES
193	select HAVE_PCSPKR_PLATFORM
194	select HAVE_PERF_EVENTS
195	select HAVE_PERF_EVENTS_NMI
196	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
197	select HAVE_PCI
198	select HAVE_PERF_REGS
199	select HAVE_PERF_USER_STACK_DUMP
200	select HAVE_RCU_TABLE_FREE		if PARAVIRT
201	select HAVE_REGS_AND_STACK_ACCESS_API
202	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
203	select HAVE_FUNCTION_ARG_ACCESS_API
204	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
205	select HAVE_STACK_VALIDATION		if X86_64
206	select HAVE_RSEQ
207	select HAVE_SYSCALL_TRACEPOINTS
208	select HAVE_UNSTABLE_SCHED_CLOCK
209	select HAVE_USER_RETURN_NOTIFIER
210	select HAVE_GENERIC_VDSO
211	select HOTPLUG_SMT			if SMP
212	select IRQ_FORCED_THREADING
213	select NEED_SG_DMA_LENGTH
214	select PCI_DOMAINS			if PCI
215	select PCI_LOCKLESS_CONFIG		if PCI
216	select PERF_EVENTS
217	select RTC_LIB
218	select RTC_MC146818_LIB
219	select SPARSE_IRQ
220	select SRCU
221	select SYSCTL_EXCEPTION_TRACE
222	select THREAD_INFO_IN_TASK
223	select USER_STACKTRACE_SUPPORT
224	select VIRT_TO_BUS
225	select X86_FEATURE_NAMES		if PROC_FS
226	select PROC_PID_ARCH_STATUS		if PROC_FS
227
228config INSTRUCTION_DECODER
229	def_bool y
230	depends on KPROBES || PERF_EVENTS || UPROBES
231
232config OUTPUT_FORMAT
233	string
234	default "elf32-i386" if X86_32
235	default "elf64-x86-64" if X86_64
236
237config ARCH_DEFCONFIG
238	string
239	default "arch/x86/configs/i386_defconfig" if X86_32
240	default "arch/x86/configs/x86_64_defconfig" if X86_64
241
242config LOCKDEP_SUPPORT
243	def_bool y
244
245config STACKTRACE_SUPPORT
246	def_bool y
247
248config MMU
249	def_bool y
250
251config ARCH_MMAP_RND_BITS_MIN
252	default 28 if 64BIT
253	default 8
254
255config ARCH_MMAP_RND_BITS_MAX
256	default 32 if 64BIT
257	default 16
258
259config ARCH_MMAP_RND_COMPAT_BITS_MIN
260	default 8
261
262config ARCH_MMAP_RND_COMPAT_BITS_MAX
263	default 16
264
265config SBUS
266	bool
267
268config GENERIC_ISA_DMA
269	def_bool y
270	depends on ISA_DMA_API
271
272config GENERIC_BUG
273	def_bool y
274	depends on BUG
275	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
276
277config GENERIC_BUG_RELATIVE_POINTERS
278	bool
279
280config ARCH_MAY_HAVE_PC_FDC
281	def_bool y
282	depends on ISA_DMA_API
283
284config GENERIC_CALIBRATE_DELAY
285	def_bool y
286
287config ARCH_HAS_CPU_RELAX
288	def_bool y
289
290config ARCH_HAS_CACHE_LINE_SIZE
291	def_bool y
292
293config ARCH_HAS_FILTER_PGPROT
294	def_bool y
295
296config HAVE_SETUP_PER_CPU_AREA
297	def_bool y
298
299config NEED_PER_CPU_EMBED_FIRST_CHUNK
300	def_bool y
301
302config NEED_PER_CPU_PAGE_FIRST_CHUNK
303	def_bool y
304
305config ARCH_HIBERNATION_POSSIBLE
306	def_bool y
307
308config ARCH_SUSPEND_POSSIBLE
309	def_bool y
310
311config ARCH_WANT_GENERAL_HUGETLB
312	def_bool y
313
314config ZONE_DMA32
315	def_bool y if X86_64
316
317config AUDIT_ARCH
318	def_bool y if X86_64
319
320config ARCH_SUPPORTS_DEBUG_PAGEALLOC
321	def_bool y
322
323config KASAN_SHADOW_OFFSET
324	hex
325	depends on KASAN
326	default 0xdffffc0000000000
327
328config HAVE_INTEL_TXT
329	def_bool y
330	depends on INTEL_IOMMU && ACPI
331
332config X86_32_SMP
333	def_bool y
334	depends on X86_32 && SMP
335
336config X86_64_SMP
337	def_bool y
338	depends on X86_64 && SMP
339
340config X86_32_LAZY_GS
341	def_bool y
342	depends on X86_32 && !STACKPROTECTOR
343
344config ARCH_SUPPORTS_UPROBES
345	def_bool y
346
347config FIX_EARLYCON_MEM
348	def_bool y
349
350config DYNAMIC_PHYSICAL_MASK
351	bool
352
353config PGTABLE_LEVELS
354	int
355	default 5 if X86_5LEVEL
356	default 4 if X86_64
357	default 3 if X86_PAE
358	default 2
359
360config CC_HAS_SANE_STACKPROTECTOR
361	bool
362	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
363	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
364	help
365	   We have to make sure stack protector is unconditionally disabled if
366	   the compiler produces broken code.
367
368menu "Processor type and features"
369
370config ZONE_DMA
371	bool "DMA memory allocation support" if EXPERT
372	default y
373	help
374	  DMA memory allocation support allows devices with less than 32-bit
375	  addressing to allocate within the first 16MB of address space.
376	  Disable if no such devices will be used.
377
378	  If unsure, say Y.
379
380config SMP
381	bool "Symmetric multi-processing support"
382	---help---
383	  This enables support for systems with more than one CPU. If you have
384	  a system with only one CPU, say N. If you have a system with more
385	  than one CPU, say Y.
386
387	  If you say N here, the kernel will run on uni- and multiprocessor
388	  machines, but will use only one CPU of a multiprocessor machine. If
389	  you say Y here, the kernel will run on many, but not all,
390	  uniprocessor machines. On a uniprocessor machine, the kernel
391	  will run faster if you say N here.
392
393	  Note that if you say Y here and choose architecture "586" or
394	  "Pentium" under "Processor family", the kernel will not work on 486
395	  architectures. Similarly, multiprocessor kernels for the "PPro"
396	  architecture may not work on all Pentium based boards.
397
398	  People using multiprocessor machines who say Y here should also say
399	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
400	  Management" code will be disabled if you say Y here.
401
402	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
403	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
404	  <http://www.tldp.org/docs.html#howto>.
405
406	  If you don't know what to do here, say N.
407
408config X86_FEATURE_NAMES
409	bool "Processor feature human-readable names" if EMBEDDED
410	default y
411	---help---
412	  This option compiles in a table of x86 feature bits and corresponding
413	  names.  This is required to support /proc/cpuinfo and a few kernel
414	  messages.  You can disable this to save space, at the expense of
415	  making those few kernel messages show numeric feature bits instead.
416
417	  If in doubt, say Y.
418
419config X86_X2APIC
420	bool "Support x2apic"
421	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
422	---help---
423	  This enables x2apic support on CPUs that have this feature.
424
425	  This allows 32-bit apic IDs (so it can support very large systems),
426	  and accesses the local apic via MSRs not via mmio.
427
428	  If you don't know what to do here, say N.
429
430config X86_MPPARSE
431	bool "Enable MPS table" if ACPI || SFI
432	default y
433	depends on X86_LOCAL_APIC
434	---help---
435	  For old smp systems that do not have proper acpi support. Newer systems
436	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
437
438config GOLDFISH
439       def_bool y
440       depends on X86_GOLDFISH
441
442config RETPOLINE
443	bool "Avoid speculative indirect branches in kernel"
444	default y
445	select STACK_VALIDATION if HAVE_STACK_VALIDATION
446	help
447	  Compile kernel with the retpoline compiler options to guard against
448	  kernel-to-user data leaks by avoiding speculative indirect
449	  branches. Requires a compiler with -mindirect-branch=thunk-extern
450	  support for full protection. The kernel may run slower.
451
452config X86_CPU_RESCTRL
453	bool "x86 CPU resource control support"
454	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
455	select KERNFS
456	help
457	  Enable x86 CPU resource control support.
458
459	  Provide support for the allocation and monitoring of system resources
460	  usage by the CPU.
461
462	  Intel calls this Intel Resource Director Technology
463	  (Intel(R) RDT). More information about RDT can be found in the
464	  Intel x86 Architecture Software Developer Manual.
465
466	  AMD calls this AMD Platform Quality of Service (AMD QoS).
467	  More information about AMD QoS can be found in the AMD64 Technology
468	  Platform Quality of Service Extensions manual.
469
470	  Say N if unsure.
471
472if X86_32
473config X86_BIGSMP
474	bool "Support for big SMP systems with more than 8 CPUs"
475	depends on SMP
476	---help---
477	  This option is needed for the systems that have more than 8 CPUs
478
479config X86_EXTENDED_PLATFORM
480	bool "Support for extended (non-PC) x86 platforms"
481	default y
482	---help---
483	  If you disable this option then the kernel will only support
484	  standard PC platforms. (which covers the vast majority of
485	  systems out there.)
486
487	  If you enable this option then you'll be able to select support
488	  for the following (non-PC) 32 bit x86 platforms:
489		Goldfish (Android emulator)
490		AMD Elan
491		RDC R-321x SoC
492		SGI 320/540 (Visual Workstation)
493		STA2X11-based (e.g. Northville)
494		Moorestown MID devices
495
496	  If you have one of these systems, or if you want to build a
497	  generic distribution kernel, say Y here - otherwise say N.
498endif
499
500if X86_64
501config X86_EXTENDED_PLATFORM
502	bool "Support for extended (non-PC) x86 platforms"
503	default y
504	---help---
505	  If you disable this option then the kernel will only support
506	  standard PC platforms. (which covers the vast majority of
507	  systems out there.)
508
509	  If you enable this option then you'll be able to select support
510	  for the following (non-PC) 64 bit x86 platforms:
511		Numascale NumaChip
512		ScaleMP vSMP
513		SGI Ultraviolet
514
515	  If you have one of these systems, or if you want to build a
516	  generic distribution kernel, say Y here - otherwise say N.
517endif
518# This is an alphabetically sorted list of 64 bit extended platforms
519# Please maintain the alphabetic order if and when there are additions
520config X86_NUMACHIP
521	bool "Numascale NumaChip"
522	depends on X86_64
523	depends on X86_EXTENDED_PLATFORM
524	depends on NUMA
525	depends on SMP
526	depends on X86_X2APIC
527	depends on PCI_MMCONFIG
528	---help---
529	  Adds support for Numascale NumaChip large-SMP systems. Needed to
530	  enable more than ~168 cores.
531	  If you don't have one of these, you should say N here.
532
533config X86_VSMP
534	bool "ScaleMP vSMP"
535	select HYPERVISOR_GUEST
536	select PARAVIRT
537	depends on X86_64 && PCI
538	depends on X86_EXTENDED_PLATFORM
539	depends on SMP
540	---help---
541	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
542	  supposed to run on these EM64T-based machines.  Only choose this option
543	  if you have one of these machines.
544
545config X86_UV
546	bool "SGI Ultraviolet"
547	depends on X86_64
548	depends on X86_EXTENDED_PLATFORM
549	depends on NUMA
550	depends on EFI
551	depends on X86_X2APIC
552	depends on PCI
553	---help---
554	  This option is needed in order to support SGI Ultraviolet systems.
555	  If you don't have one of these, you should say N here.
556
557# Following is an alphabetically sorted list of 32 bit extended platforms
558# Please maintain the alphabetic order if and when there are additions
559
560config X86_GOLDFISH
561       bool "Goldfish (Virtual Platform)"
562       depends on X86_EXTENDED_PLATFORM
563       ---help---
564	 Enable support for the Goldfish virtual platform used primarily
565	 for Android development. Unless you are building for the Android
566	 Goldfish emulator say N here.
567
568config X86_INTEL_CE
569	bool "CE4100 TV platform"
570	depends on PCI
571	depends on PCI_GODIRECT
572	depends on X86_IO_APIC
573	depends on X86_32
574	depends on X86_EXTENDED_PLATFORM
575	select X86_REBOOTFIXUPS
576	select OF
577	select OF_EARLY_FLATTREE
578	---help---
579	  Select for the Intel CE media processor (CE4100) SOC.
580	  This option compiles in support for the CE4100 SOC for settop
581	  boxes and media devices.
582
583config X86_INTEL_MID
584	bool "Intel MID platform support"
585	depends on X86_EXTENDED_PLATFORM
586	depends on X86_PLATFORM_DEVICES
587	depends on PCI
588	depends on X86_64 || (PCI_GOANY && X86_32)
589	depends on X86_IO_APIC
590	select SFI
591	select I2C
592	select DW_APB_TIMER
593	select APB_TIMER
594	select INTEL_SCU_IPC
595	select MFD_INTEL_MSIC
596	---help---
597	  Select to build a kernel capable of supporting Intel MID (Mobile
598	  Internet Device) platform systems which do not have the PCI legacy
599	  interfaces. If you are building for a PC class system say N here.
600
601	  Intel MID platforms are based on an Intel processor and chipset which
602	  consume less power than most of the x86 derivatives.
603
604config X86_INTEL_QUARK
605	bool "Intel Quark platform support"
606	depends on X86_32
607	depends on X86_EXTENDED_PLATFORM
608	depends on X86_PLATFORM_DEVICES
609	depends on X86_TSC
610	depends on PCI
611	depends on PCI_GOANY
612	depends on X86_IO_APIC
613	select IOSF_MBI
614	select INTEL_IMR
615	select COMMON_CLK
616	---help---
617	  Select to include support for Quark X1000 SoC.
618	  Say Y here if you have a Quark based system such as the Arduino
619	  compatible Intel Galileo.
620
621config X86_INTEL_LPSS
622	bool "Intel Low Power Subsystem Support"
623	depends on X86 && ACPI && PCI
624	select COMMON_CLK
625	select PINCTRL
626	select IOSF_MBI
627	---help---
628	  Select to build support for Intel Low Power Subsystem such as
629	  found on Intel Lynxpoint PCH. Selecting this option enables
630	  things like clock tree (common clock framework) and pincontrol
631	  which are needed by the LPSS peripheral drivers.
632
633config X86_AMD_PLATFORM_DEVICE
634	bool "AMD ACPI2Platform devices support"
635	depends on ACPI
636	select COMMON_CLK
637	select PINCTRL
638	---help---
639	  Select to interpret AMD specific ACPI device to platform device
640	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
641	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
642	  implemented under PINCTRL subsystem.
643
644config IOSF_MBI
645	tristate "Intel SoC IOSF Sideband support for SoC platforms"
646	depends on PCI
647	---help---
648	  This option enables sideband register access support for Intel SoC
649	  platforms. On these platforms the IOSF sideband is used in lieu of
650	  MSR's for some register accesses, mostly but not limited to thermal
651	  and power. Drivers may query the availability of this device to
652	  determine if they need the sideband in order to work on these
653	  platforms. The sideband is available on the following SoC products.
654	  This list is not meant to be exclusive.
655	   - BayTrail
656	   - Braswell
657	   - Quark
658
659	  You should say Y if you are running a kernel on one of these SoC's.
660
661config IOSF_MBI_DEBUG
662	bool "Enable IOSF sideband access through debugfs"
663	depends on IOSF_MBI && DEBUG_FS
664	---help---
665	  Select this option to expose the IOSF sideband access registers (MCR,
666	  MDR, MCRX) through debugfs to write and read register information from
667	  different units on the SoC. This is most useful for obtaining device
668	  state information for debug and analysis. As this is a general access
669	  mechanism, users of this option would have specific knowledge of the
670	  device they want to access.
671
672	  If you don't require the option or are in doubt, say N.
673
674config X86_RDC321X
675	bool "RDC R-321x SoC"
676	depends on X86_32
677	depends on X86_EXTENDED_PLATFORM
678	select M486
679	select X86_REBOOTFIXUPS
680	---help---
681	  This option is needed for RDC R-321x system-on-chip, also known
682	  as R-8610-(G).
683	  If you don't have one of these chips, you should say N here.
684
685config X86_32_NON_STANDARD
686	bool "Support non-standard 32-bit SMP architectures"
687	depends on X86_32 && SMP
688	depends on X86_EXTENDED_PLATFORM
689	---help---
690	  This option compiles in the bigsmp and STA2X11 default
691	  subarchitectures.  It is intended for a generic binary
692	  kernel. If you select them all, kernel will probe it one by
693	  one and will fallback to default.
694
695# Alphabetically sorted list of Non standard 32 bit platforms
696
697config X86_SUPPORTS_MEMORY_FAILURE
698	def_bool y
699	# MCE code calls memory_failure():
700	depends on X86_MCE
701	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
702	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
703	depends on X86_64 || !SPARSEMEM
704	select ARCH_SUPPORTS_MEMORY_FAILURE
705
706config STA2X11
707	bool "STA2X11 Companion Chip Support"
708	depends on X86_32_NON_STANDARD && PCI
709	select ARCH_HAS_PHYS_TO_DMA
710	select SWIOTLB
711	select MFD_STA2X11
712	select GPIOLIB
713	---help---
714	  This adds support for boards based on the STA2X11 IO-Hub,
715	  a.k.a. "ConneXt". The chip is used in place of the standard
716	  PC chipset, so all "standard" peripherals are missing. If this
717	  option is selected the kernel will still be able to boot on
718	  standard PC machines.
719
720config X86_32_IRIS
721	tristate "Eurobraille/Iris poweroff module"
722	depends on X86_32
723	---help---
724	  The Iris machines from EuroBraille do not have APM or ACPI support
725	  to shut themselves down properly.  A special I/O sequence is
726	  needed to do so, which is what this module does at
727	  kernel shutdown.
728
729	  This is only for Iris machines from EuroBraille.
730
731	  If unused, say N.
732
733config SCHED_OMIT_FRAME_POINTER
734	def_bool y
735	prompt "Single-depth WCHAN output"
736	depends on X86
737	---help---
738	  Calculate simpler /proc/<PID>/wchan values. If this option
739	  is disabled then wchan values will recurse back to the
740	  caller function. This provides more accurate wchan values,
741	  at the expense of slightly more scheduling overhead.
742
743	  If in doubt, say "Y".
744
745menuconfig HYPERVISOR_GUEST
746	bool "Linux guest support"
747	---help---
748	  Say Y here to enable options for running Linux under various hyper-
749	  visors. This option enables basic hypervisor detection and platform
750	  setup.
751
752	  If you say N, all options in this submenu will be skipped and
753	  disabled, and Linux guest support won't be built in.
754
755if HYPERVISOR_GUEST
756
757config PARAVIRT
758	bool "Enable paravirtualization code"
759	---help---
760	  This changes the kernel so it can modify itself when it is run
761	  under a hypervisor, potentially improving performance significantly
762	  over full virtualization.  However, when run without a hypervisor
763	  the kernel is theoretically slower and slightly larger.
764
765config PARAVIRT_XXL
766	bool
767
768config PARAVIRT_DEBUG
769	bool "paravirt-ops debugging"
770	depends on PARAVIRT && DEBUG_KERNEL
771	---help---
772	  Enable to debug paravirt_ops internals.  Specifically, BUG if
773	  a paravirt_op is missing when it is called.
774
775config PARAVIRT_SPINLOCKS
776	bool "Paravirtualization layer for spinlocks"
777	depends on PARAVIRT && SMP
778	---help---
779	  Paravirtualized spinlocks allow a pvops backend to replace the
780	  spinlock implementation with something virtualization-friendly
781	  (for example, block the virtual CPU rather than spinning).
782
783	  It has a minimal impact on native kernels and gives a nice performance
784	  benefit on paravirtualized KVM / Xen kernels.
785
786	  If you are unsure how to answer this question, answer Y.
787
788config X86_HV_CALLBACK_VECTOR
789	def_bool n
790
791source "arch/x86/xen/Kconfig"
792
793config KVM_GUEST
794	bool "KVM Guest support (including kvmclock)"
795	depends on PARAVIRT
796	select PARAVIRT_CLOCK
797	default y
798	---help---
799	  This option enables various optimizations for running under the KVM
800	  hypervisor. It includes a paravirtualized clock, so that instead
801	  of relying on a PIT (or probably other) emulation by the
802	  underlying device model, the host provides the guest with
803	  timing infrastructure such as time of day, and system time
804
805config PVH
806	bool "Support for running PVH guests"
807	---help---
808	  This option enables the PVH entry point for guest virtual machines
809	  as specified in the x86/HVM direct boot ABI.
810
811config KVM_DEBUG_FS
812	bool "Enable debug information for KVM Guests in debugfs"
813	depends on KVM_GUEST && DEBUG_FS
814	---help---
815	  This option enables collection of various statistics for KVM guest.
816	  Statistics are displayed in debugfs filesystem. Enabling this option
817	  may incur significant overhead.
818
819config PARAVIRT_TIME_ACCOUNTING
820	bool "Paravirtual steal time accounting"
821	depends on PARAVIRT
822	---help---
823	  Select this option to enable fine granularity task steal time
824	  accounting. Time spent executing other tasks in parallel with
825	  the current vCPU is discounted from the vCPU power. To account for
826	  that, there can be a small performance impact.
827
828	  If in doubt, say N here.
829
830config PARAVIRT_CLOCK
831	bool
832
833config JAILHOUSE_GUEST
834	bool "Jailhouse non-root cell support"
835	depends on X86_64 && PCI
836	select X86_PM_TIMER
837	---help---
838	  This option allows to run Linux as guest in a Jailhouse non-root
839	  cell. You can leave this option disabled if you only want to start
840	  Jailhouse and run Linux afterwards in the root cell.
841
842config ACRN_GUEST
843	bool "ACRN Guest support"
844	depends on X86_64
845	select X86_HV_CALLBACK_VECTOR
846	help
847	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
848	  a flexible, lightweight reference open-source hypervisor, built with
849	  real-time and safety-criticality in mind. It is built for embedded
850	  IOT with small footprint and real-time features. More details can be
851	  found in https://projectacrn.org/.
852
853endif #HYPERVISOR_GUEST
854
855source "arch/x86/Kconfig.cpu"
856
857config HPET_TIMER
858	def_bool X86_64
859	prompt "HPET Timer Support" if X86_32
860	---help---
861	  Use the IA-PC HPET (High Precision Event Timer) to manage
862	  time in preference to the PIT and RTC, if a HPET is
863	  present.
864	  HPET is the next generation timer replacing legacy 8254s.
865	  The HPET provides a stable time base on SMP
866	  systems, unlike the TSC, but it is more expensive to access,
867	  as it is off-chip.  The interface used is documented
868	  in the HPET spec, revision 1.
869
870	  You can safely choose Y here.  However, HPET will only be
871	  activated if the platform and the BIOS support this feature.
872	  Otherwise the 8254 will be used for timing services.
873
874	  Choose N to continue using the legacy 8254 timer.
875
876config HPET_EMULATE_RTC
877	def_bool y
878	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
879
880config APB_TIMER
881       def_bool y if X86_INTEL_MID
882       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
883       select DW_APB_TIMER
884       depends on X86_INTEL_MID && SFI
885       help
886         APB timer is the replacement for 8254, HPET on X86 MID platforms.
887         The APBT provides a stable time base on SMP
888         systems, unlike the TSC, but it is more expensive to access,
889         as it is off-chip. APB timers are always running regardless of CPU
890         C states, they are used as per CPU clockevent device when possible.
891
892# Mark as expert because too many people got it wrong.
893# The code disables itself when not needed.
894config DMI
895	default y
896	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
897	bool "Enable DMI scanning" if EXPERT
898	---help---
899	  Enabled scanning of DMI to identify machine quirks. Say Y
900	  here unless you have verified that your setup is not
901	  affected by entries in the DMI blacklist. Required by PNP
902	  BIOS code.
903
904config GART_IOMMU
905	bool "Old AMD GART IOMMU support"
906	select IOMMU_HELPER
907	select SWIOTLB
908	depends on X86_64 && PCI && AMD_NB
909	---help---
910	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
911	  GART based hardware IOMMUs.
912
913	  The GART supports full DMA access for devices with 32-bit access
914	  limitations, on systems with more than 3 GB. This is usually needed
915	  for USB, sound, many IDE/SATA chipsets and some other devices.
916
917	  Newer systems typically have a modern AMD IOMMU, supported via
918	  the CONFIG_AMD_IOMMU=y config option.
919
920	  In normal configurations this driver is only active when needed:
921	  there's more than 3 GB of memory and the system contains a
922	  32-bit limited device.
923
924	  If unsure, say Y.
925
926config CALGARY_IOMMU
927	bool "IBM Calgary IOMMU support"
928	select IOMMU_HELPER
929	select SWIOTLB
930	depends on X86_64 && PCI
931	---help---
932	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
933	  systems. Needed to run systems with more than 3GB of memory
934	  properly with 32-bit PCI devices that do not support DAC
935	  (Double Address Cycle). Calgary also supports bus level
936	  isolation, where all DMAs pass through the IOMMU.  This
937	  prevents them from going anywhere except their intended
938	  destination. This catches hard-to-find kernel bugs and
939	  mis-behaving drivers and devices that do not use the DMA-API
940	  properly to set up their DMA buffers.  The IOMMU can be
941	  turned off at boot time with the iommu=off parameter.
942	  Normally the kernel will make the right choice by itself.
943	  If unsure, say Y.
944
945config CALGARY_IOMMU_ENABLED_BY_DEFAULT
946	def_bool y
947	prompt "Should Calgary be enabled by default?"
948	depends on CALGARY_IOMMU
949	---help---
950	  Should Calgary be enabled by default? if you choose 'y', Calgary
951	  will be used (if it exists). If you choose 'n', Calgary will not be
952	  used even if it exists. If you choose 'n' and would like to use
953	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
954	  If unsure, say Y.
955
956config MAXSMP
957	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
958	depends on X86_64 && SMP && DEBUG_KERNEL
959	select CPUMASK_OFFSTACK
960	---help---
961	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
962	  If unsure, say N.
963
964#
965# The maximum number of CPUs supported:
966#
967# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
968# and which can be configured interactively in the
969# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
970#
971# The ranges are different on 32-bit and 64-bit kernels, depending on
972# hardware capabilities and scalability features of the kernel.
973#
974# ( If MAXSMP is enabled we just use the highest possible value and disable
975#   interactive configuration. )
976#
977
978config NR_CPUS_RANGE_BEGIN
979	int
980	default NR_CPUS_RANGE_END if MAXSMP
981	default    1 if !SMP
982	default    2
983
984config NR_CPUS_RANGE_END
985	int
986	depends on X86_32
987	default   64 if  SMP &&  X86_BIGSMP
988	default    8 if  SMP && !X86_BIGSMP
989	default    1 if !SMP
990
991config NR_CPUS_RANGE_END
992	int
993	depends on X86_64
994	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
995	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
996	default    1 if !SMP
997
998config NR_CPUS_DEFAULT
999	int
1000	depends on X86_32
1001	default   32 if  X86_BIGSMP
1002	default    8 if  SMP
1003	default    1 if !SMP
1004
1005config NR_CPUS_DEFAULT
1006	int
1007	depends on X86_64
1008	default 8192 if  MAXSMP
1009	default   64 if  SMP
1010	default    1 if !SMP
1011
1012config NR_CPUS
1013	int "Maximum number of CPUs" if SMP && !MAXSMP
1014	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1015	default NR_CPUS_DEFAULT
1016	---help---
1017	  This allows you to specify the maximum number of CPUs which this
1018	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1019	  supported value is 8192, otherwise the maximum value is 512.  The
1020	  minimum value which makes sense is 2.
1021
1022	  This is purely to save memory: each supported CPU adds about 8KB
1023	  to the kernel image.
1024
1025config SCHED_SMT
1026	def_bool y if SMP
1027
1028config SCHED_MC
1029	def_bool y
1030	prompt "Multi-core scheduler support"
1031	depends on SMP
1032	---help---
1033	  Multi-core scheduler support improves the CPU scheduler's decision
1034	  making when dealing with multi-core CPU chips at a cost of slightly
1035	  increased overhead in some places. If unsure say N here.
1036
1037config SCHED_MC_PRIO
1038	bool "CPU core priorities scheduler support"
1039	depends on SCHED_MC && CPU_SUP_INTEL
1040	select X86_INTEL_PSTATE
1041	select CPU_FREQ
1042	default y
1043	---help---
1044	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1045	  core ordering determined at manufacturing time, which allows
1046	  certain cores to reach higher turbo frequencies (when running
1047	  single threaded workloads) than others.
1048
1049	  Enabling this kernel feature teaches the scheduler about
1050	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1051	  scheduler's CPU selection logic accordingly, so that higher
1052	  overall system performance can be achieved.
1053
1054	  This feature will have no effect on CPUs without this feature.
1055
1056	  If unsure say Y here.
1057
1058config UP_LATE_INIT
1059       def_bool y
1060       depends on !SMP && X86_LOCAL_APIC
1061
1062config X86_UP_APIC
1063	bool "Local APIC support on uniprocessors" if !PCI_MSI
1064	default PCI_MSI
1065	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1066	---help---
1067	  A local APIC (Advanced Programmable Interrupt Controller) is an
1068	  integrated interrupt controller in the CPU. If you have a single-CPU
1069	  system which has a processor with a local APIC, you can say Y here to
1070	  enable and use it. If you say Y here even though your machine doesn't
1071	  have a local APIC, then the kernel will still run with no slowdown at
1072	  all. The local APIC supports CPU-generated self-interrupts (timer,
1073	  performance counters), and the NMI watchdog which detects hard
1074	  lockups.
1075
1076config X86_UP_IOAPIC
1077	bool "IO-APIC support on uniprocessors"
1078	depends on X86_UP_APIC
1079	---help---
1080	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1081	  SMP-capable replacement for PC-style interrupt controllers. Most
1082	  SMP systems and many recent uniprocessor systems have one.
1083
1084	  If you have a single-CPU system with an IO-APIC, you can say Y here
1085	  to use it. If you say Y here even though your machine doesn't have
1086	  an IO-APIC, then the kernel will still run with no slowdown at all.
1087
1088config X86_LOCAL_APIC
1089	def_bool y
1090	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1091	select IRQ_DOMAIN_HIERARCHY
1092	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1093
1094config X86_IO_APIC
1095	def_bool y
1096	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1097
1098config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1099	bool "Reroute for broken boot IRQs"
1100	depends on X86_IO_APIC
1101	---help---
1102	  This option enables a workaround that fixes a source of
1103	  spurious interrupts. This is recommended when threaded
1104	  interrupt handling is used on systems where the generation of
1105	  superfluous "boot interrupts" cannot be disabled.
1106
1107	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1108	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1109	  kernel does during interrupt handling). On chipsets where this
1110	  boot IRQ generation cannot be disabled, this workaround keeps
1111	  the original IRQ line masked so that only the equivalent "boot
1112	  IRQ" is delivered to the CPUs. The workaround also tells the
1113	  kernel to set up the IRQ handler on the boot IRQ line. In this
1114	  way only one interrupt is delivered to the kernel. Otherwise
1115	  the spurious second interrupt may cause the kernel to bring
1116	  down (vital) interrupt lines.
1117
1118	  Only affects "broken" chipsets. Interrupt sharing may be
1119	  increased on these systems.
1120
1121config X86_MCE
1122	bool "Machine Check / overheating reporting"
1123	select GENERIC_ALLOCATOR
1124	default y
1125	---help---
1126	  Machine Check support allows the processor to notify the
1127	  kernel if it detects a problem (e.g. overheating, data corruption).
1128	  The action the kernel takes depends on the severity of the problem,
1129	  ranging from warning messages to halting the machine.
1130
1131config X86_MCELOG_LEGACY
1132	bool "Support for deprecated /dev/mcelog character device"
1133	depends on X86_MCE
1134	---help---
1135	  Enable support for /dev/mcelog which is needed by the old mcelog
1136	  userspace logging daemon. Consider switching to the new generation
1137	  rasdaemon solution.
1138
1139config X86_MCE_INTEL
1140	def_bool y
1141	prompt "Intel MCE features"
1142	depends on X86_MCE && X86_LOCAL_APIC
1143	---help---
1144	   Additional support for intel specific MCE features such as
1145	   the thermal monitor.
1146
1147config X86_MCE_AMD
1148	def_bool y
1149	prompt "AMD MCE features"
1150	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1151	---help---
1152	   Additional support for AMD specific MCE features such as
1153	   the DRAM Error Threshold.
1154
1155config X86_ANCIENT_MCE
1156	bool "Support for old Pentium 5 / WinChip machine checks"
1157	depends on X86_32 && X86_MCE
1158	---help---
1159	  Include support for machine check handling on old Pentium 5 or WinChip
1160	  systems. These typically need to be enabled explicitly on the command
1161	  line.
1162
1163config X86_MCE_THRESHOLD
1164	depends on X86_MCE_AMD || X86_MCE_INTEL
1165	def_bool y
1166
1167config X86_MCE_INJECT
1168	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1169	tristate "Machine check injector support"
1170	---help---
1171	  Provide support for injecting machine checks for testing purposes.
1172	  If you don't know what a machine check is and you don't do kernel
1173	  QA it is safe to say n.
1174
1175config X86_THERMAL_VECTOR
1176	def_bool y
1177	depends on X86_MCE_INTEL
1178
1179source "arch/x86/events/Kconfig"
1180
1181config X86_LEGACY_VM86
1182	bool "Legacy VM86 support"
1183	depends on X86_32
1184	---help---
1185	  This option allows user programs to put the CPU into V8086
1186	  mode, which is an 80286-era approximation of 16-bit real mode.
1187
1188	  Some very old versions of X and/or vbetool require this option
1189	  for user mode setting.  Similarly, DOSEMU will use it if
1190	  available to accelerate real mode DOS programs.  However, any
1191	  recent version of DOSEMU, X, or vbetool should be fully
1192	  functional even without kernel VM86 support, as they will all
1193	  fall back to software emulation. Nevertheless, if you are using
1194	  a 16-bit DOS program where 16-bit performance matters, vm86
1195	  mode might be faster than emulation and you might want to
1196	  enable this option.
1197
1198	  Note that any app that works on a 64-bit kernel is unlikely to
1199	  need this option, as 64-bit kernels don't, and can't, support
1200	  V8086 mode. This option is also unrelated to 16-bit protected
1201	  mode and is not needed to run most 16-bit programs under Wine.
1202
1203	  Enabling this option increases the complexity of the kernel
1204	  and slows down exception handling a tiny bit.
1205
1206	  If unsure, say N here.
1207
1208config VM86
1209       bool
1210       default X86_LEGACY_VM86
1211
1212config X86_16BIT
1213	bool "Enable support for 16-bit segments" if EXPERT
1214	default y
1215	depends on MODIFY_LDT_SYSCALL
1216	---help---
1217	  This option is required by programs like Wine to run 16-bit
1218	  protected mode legacy code on x86 processors.  Disabling
1219	  this option saves about 300 bytes on i386, or around 6K text
1220	  plus 16K runtime memory on x86-64,
1221
1222config X86_ESPFIX32
1223	def_bool y
1224	depends on X86_16BIT && X86_32
1225
1226config X86_ESPFIX64
1227	def_bool y
1228	depends on X86_16BIT && X86_64
1229
1230config X86_VSYSCALL_EMULATION
1231       bool "Enable vsyscall emulation" if EXPERT
1232       default y
1233       depends on X86_64
1234       ---help---
1235	 This enables emulation of the legacy vsyscall page.  Disabling
1236	 it is roughly equivalent to booting with vsyscall=none, except
1237	 that it will also disable the helpful warning if a program
1238	 tries to use a vsyscall.  With this option set to N, offending
1239	 programs will just segfault, citing addresses of the form
1240	 0xffffffffff600?00.
1241
1242	 This option is required by many programs built before 2013, and
1243	 care should be used even with newer programs if set to N.
1244
1245	 Disabling this option saves about 7K of kernel size and
1246	 possibly 4K of additional runtime pagetable memory.
1247
1248config TOSHIBA
1249	tristate "Toshiba Laptop support"
1250	depends on X86_32
1251	---help---
1252	  This adds a driver to safely access the System Management Mode of
1253	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254	  not work on models with a Phoenix BIOS. The System Management Mode
1255	  is used to set the BIOS and power saving options on Toshiba portables.
1256
1257	  For information on utilities to make use of this driver see the
1258	  Toshiba Linux utilities web site at:
1259	  <http://www.buzzard.org.uk/toshiba/>.
1260
1261	  Say Y if you intend to run this kernel on a Toshiba portable.
1262	  Say N otherwise.
1263
1264config I8K
1265	tristate "Dell i8k legacy laptop support"
1266	select HWMON
1267	select SENSORS_DELL_SMM
1268	---help---
1269	  This option enables legacy /proc/i8k userspace interface in hwmon
1270	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1271	  temperature and allows controlling fan speeds of Dell laptops via
1272	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1273	  it reports also power and hotkey status. For fan speed control is
1274	  needed userspace package i8kutils.
1275
1276	  Say Y if you intend to run this kernel on old Dell laptops or want to
1277	  use userspace package i8kutils.
1278	  Say N otherwise.
1279
1280config X86_REBOOTFIXUPS
1281	bool "Enable X86 board specific fixups for reboot"
1282	depends on X86_32
1283	---help---
1284	  This enables chipset and/or board specific fixups to be done
1285	  in order to get reboot to work correctly. This is only needed on
1286	  some combinations of hardware and BIOS. The symptom, for which
1287	  this config is intended, is when reboot ends with a stalled/hung
1288	  system.
1289
1290	  Currently, the only fixup is for the Geode machines using
1291	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1292
1293	  Say Y if you want to enable the fixup. Currently, it's safe to
1294	  enable this option even if you don't need it.
1295	  Say N otherwise.
1296
1297config MICROCODE
1298	bool "CPU microcode loading support"
1299	default y
1300	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1301	select FW_LOADER
1302	---help---
1303	  If you say Y here, you will be able to update the microcode on
1304	  Intel and AMD processors. The Intel support is for the IA32 family,
1305	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1306	  AMD support is for families 0x10 and later. You will obviously need
1307	  the actual microcode binary data itself which is not shipped with
1308	  the Linux kernel.
1309
1310	  The preferred method to load microcode from a detached initrd is described
1311	  in Documentation/x86/microcode.rst. For that you need to enable
1312	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1313	  initrd for microcode blobs.
1314
1315	  In addition, you can build the microcode into the kernel. For that you
1316	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1317	  config option.
1318
1319config MICROCODE_INTEL
1320	bool "Intel microcode loading support"
1321	depends on MICROCODE
1322	default MICROCODE
1323	select FW_LOADER
1324	---help---
1325	  This options enables microcode patch loading support for Intel
1326	  processors.
1327
1328	  For the current Intel microcode data package go to
1329	  <https://downloadcenter.intel.com> and search for
1330	  'Linux Processor Microcode Data File'.
1331
1332config MICROCODE_AMD
1333	bool "AMD microcode loading support"
1334	depends on MICROCODE
1335	select FW_LOADER
1336	---help---
1337	  If you select this option, microcode patch loading support for AMD
1338	  processors will be enabled.
1339
1340config MICROCODE_OLD_INTERFACE
1341	bool "Ancient loading interface (DEPRECATED)"
1342	default n
1343	depends on MICROCODE
1344	---help---
1345	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1346	  which was used by userspace tools like iucode_tool and microcode.ctl.
1347	  It is inadequate because it runs too late to be able to properly
1348	  load microcode on a machine and it needs special tools. Instead, you
1349	  should've switched to the early loading method with the initrd or
1350	  builtin microcode by now: Documentation/x86/microcode.rst
1351
1352config X86_MSR
1353	tristate "/dev/cpu/*/msr - Model-specific register support"
1354	---help---
1355	  This device gives privileged processes access to the x86
1356	  Model-Specific Registers (MSRs).  It is a character device with
1357	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358	  MSR accesses are directed to a specific CPU on multi-processor
1359	  systems.
1360
1361config X86_CPUID
1362	tristate "/dev/cpu/*/cpuid - CPU information support"
1363	---help---
1364	  This device gives processes access to the x86 CPUID instruction to
1365	  be executed on a specific processor.  It is a character device
1366	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367	  /dev/cpu/31/cpuid.
1368
1369choice
1370	prompt "High Memory Support"
1371	default HIGHMEM4G
1372	depends on X86_32
1373
1374config NOHIGHMEM
1375	bool "off"
1376	---help---
1377	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378	  However, the address space of 32-bit x86 processors is only 4
1379	  Gigabytes large. That means that, if you have a large amount of
1380	  physical memory, not all of it can be "permanently mapped" by the
1381	  kernel. The physical memory that's not permanently mapped is called
1382	  "high memory".
1383
1384	  If you are compiling a kernel which will never run on a machine with
1385	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1386	  choice and suitable for most users). This will result in a "3GB/1GB"
1387	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1388	  space and the remaining part of the 4GB virtual memory space is used
1389	  by the kernel to permanently map as much physical memory as
1390	  possible.
1391
1392	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1393	  answer "4GB" here.
1394
1395	  If more than 4 Gigabytes is used then answer "64GB" here. This
1396	  selection turns Intel PAE (Physical Address Extension) mode on.
1397	  PAE implements 3-level paging on IA32 processors. PAE is fully
1398	  supported by Linux, PAE mode is implemented on all recent Intel
1399	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400	  then the kernel will not boot on CPUs that don't support PAE!
1401
1402	  The actual amount of total physical memory will either be
1403	  auto detected or can be forced by using a kernel command line option
1404	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1405	  your boot loader (lilo or loadlin) about how to pass options to the
1406	  kernel at boot time.)
1407
1408	  If unsure, say "off".
1409
1410config HIGHMEM4G
1411	bool "4GB"
1412	---help---
1413	  Select this if you have a 32-bit processor and between 1 and 4
1414	  gigabytes of physical RAM.
1415
1416config HIGHMEM64G
1417	bool "64GB"
1418	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1419	select X86_PAE
1420	---help---
1421	  Select this if you have a 32-bit processor and more than 4
1422	  gigabytes of physical RAM.
1423
1424endchoice
1425
1426choice
1427	prompt "Memory split" if EXPERT
1428	default VMSPLIT_3G
1429	depends on X86_32
1430	---help---
1431	  Select the desired split between kernel and user memory.
1432
1433	  If the address range available to the kernel is less than the
1434	  physical memory installed, the remaining memory will be available
1435	  as "high memory". Accessing high memory is a little more costly
1436	  than low memory, as it needs to be mapped into the kernel first.
1437	  Note that increasing the kernel address space limits the range
1438	  available to user programs, making the address space there
1439	  tighter.  Selecting anything other than the default 3G/1G split
1440	  will also likely make your kernel incompatible with binary-only
1441	  kernel modules.
1442
1443	  If you are not absolutely sure what you are doing, leave this
1444	  option alone!
1445
1446	config VMSPLIT_3G
1447		bool "3G/1G user/kernel split"
1448	config VMSPLIT_3G_OPT
1449		depends on !X86_PAE
1450		bool "3G/1G user/kernel split (for full 1G low memory)"
1451	config VMSPLIT_2G
1452		bool "2G/2G user/kernel split"
1453	config VMSPLIT_2G_OPT
1454		depends on !X86_PAE
1455		bool "2G/2G user/kernel split (for full 2G low memory)"
1456	config VMSPLIT_1G
1457		bool "1G/3G user/kernel split"
1458endchoice
1459
1460config PAGE_OFFSET
1461	hex
1462	default 0xB0000000 if VMSPLIT_3G_OPT
1463	default 0x80000000 if VMSPLIT_2G
1464	default 0x78000000 if VMSPLIT_2G_OPT
1465	default 0x40000000 if VMSPLIT_1G
1466	default 0xC0000000
1467	depends on X86_32
1468
1469config HIGHMEM
1470	def_bool y
1471	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1472
1473config X86_PAE
1474	bool "PAE (Physical Address Extension) Support"
1475	depends on X86_32 && !HIGHMEM4G
1476	select PHYS_ADDR_T_64BIT
1477	select SWIOTLB
1478	---help---
1479	  PAE is required for NX support, and furthermore enables
1480	  larger swapspace support for non-overcommit purposes. It
1481	  has the cost of more pagetable lookup overhead, and also
1482	  consumes more pagetable space per process.
1483
1484config X86_5LEVEL
1485	bool "Enable 5-level page tables support"
1486	select DYNAMIC_MEMORY_LAYOUT
1487	select SPARSEMEM_VMEMMAP
1488	depends on X86_64
1489	---help---
1490	  5-level paging enables access to larger address space:
1491	  upto 128 PiB of virtual address space and 4 PiB of
1492	  physical address space.
1493
1494	  It will be supported by future Intel CPUs.
1495
1496	  A kernel with the option enabled can be booted on machines that
1497	  support 4- or 5-level paging.
1498
1499	  See Documentation/x86/x86_64/5level-paging.rst for more
1500	  information.
1501
1502	  Say N if unsure.
1503
1504config X86_DIRECT_GBPAGES
1505	def_bool y
1506	depends on X86_64 && !DEBUG_PAGEALLOC
1507	---help---
1508	  Certain kernel features effectively disable kernel
1509	  linear 1 GB mappings (even if the CPU otherwise
1510	  supports them), so don't confuse the user by printing
1511	  that we have them enabled.
1512
1513config X86_CPA_STATISTICS
1514	bool "Enable statistic for Change Page Attribute"
1515	depends on DEBUG_FS
1516	---help---
1517	  Expose statistics about the Change Page Attribute mechanims, which
1518	  helps to determine the effectiveness of preserving large and huge
1519	  page mappings when mapping protections are changed.
1520
1521config ARCH_HAS_MEM_ENCRYPT
1522	def_bool y
1523
1524config AMD_MEM_ENCRYPT
1525	bool "AMD Secure Memory Encryption (SME) support"
1526	depends on X86_64 && CPU_SUP_AMD
1527	select DYNAMIC_PHYSICAL_MASK
1528	select ARCH_USE_MEMREMAP_PROT
1529	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1530	---help---
1531	  Say yes to enable support for the encryption of system memory.
1532	  This requires an AMD processor that supports Secure Memory
1533	  Encryption (SME).
1534
1535config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1536	bool "Activate AMD Secure Memory Encryption (SME) by default"
1537	default y
1538	depends on AMD_MEM_ENCRYPT
1539	---help---
1540	  Say yes to have system memory encrypted by default if running on
1541	  an AMD processor that supports Secure Memory Encryption (SME).
1542
1543	  If set to Y, then the encryption of system memory can be
1544	  deactivated with the mem_encrypt=off command line option.
1545
1546	  If set to N, then the encryption of system memory can be
1547	  activated with the mem_encrypt=on command line option.
1548
1549# Common NUMA Features
1550config NUMA
1551	bool "Numa Memory Allocation and Scheduler Support"
1552	depends on SMP
1553	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554	default y if X86_BIGSMP
1555	---help---
1556	  Enable NUMA (Non Uniform Memory Access) support.
1557
1558	  The kernel will try to allocate memory used by a CPU on the
1559	  local memory controller of the CPU and add some more
1560	  NUMA awareness to the kernel.
1561
1562	  For 64-bit this is recommended if the system is Intel Core i7
1563	  (or later), AMD Opteron, or EM64T NUMA.
1564
1565	  For 32-bit this is only needed if you boot a 32-bit
1566	  kernel on a 64-bit NUMA platform.
1567
1568	  Otherwise, you should say N.
1569
1570config AMD_NUMA
1571	def_bool y
1572	prompt "Old style AMD Opteron NUMA detection"
1573	depends on X86_64 && NUMA && PCI
1574	---help---
1575	  Enable AMD NUMA node topology detection.  You should say Y here if
1576	  you have a multi processor AMD system. This uses an old method to
1577	  read the NUMA configuration directly from the builtin Northbridge
1578	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1579	  which also takes priority if both are compiled in.
1580
1581config X86_64_ACPI_NUMA
1582	def_bool y
1583	prompt "ACPI NUMA detection"
1584	depends on X86_64 && NUMA && ACPI && PCI
1585	select ACPI_NUMA
1586	---help---
1587	  Enable ACPI SRAT based node topology detection.
1588
1589# Some NUMA nodes have memory ranges that span
1590# other nodes.  Even though a pfn is valid and
1591# between a node's start and end pfns, it may not
1592# reside on that node.  See memmap_init_zone()
1593# for details.
1594config NODES_SPAN_OTHER_NODES
1595	def_bool y
1596	depends on X86_64_ACPI_NUMA
1597
1598config NUMA_EMU
1599	bool "NUMA emulation"
1600	depends on NUMA
1601	---help---
1602	  Enable NUMA emulation. A flat machine will be split
1603	  into virtual nodes when booted with "numa=fake=N", where N is the
1604	  number of nodes. This is only useful for debugging.
1605
1606config NODES_SHIFT
1607	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1608	range 1 10
1609	default "10" if MAXSMP
1610	default "6" if X86_64
1611	default "3"
1612	depends on NEED_MULTIPLE_NODES
1613	---help---
1614	  Specify the maximum number of NUMA Nodes available on the target
1615	  system.  Increases memory reserved to accommodate various tables.
1616
1617config ARCH_HAVE_MEMORY_PRESENT
1618	def_bool y
1619	depends on X86_32 && DISCONTIGMEM
1620
1621config ARCH_FLATMEM_ENABLE
1622	def_bool y
1623	depends on X86_32 && !NUMA
1624
1625config ARCH_DISCONTIGMEM_ENABLE
1626	def_bool n
1627	depends on NUMA && X86_32
1628	depends on BROKEN
1629
1630config ARCH_SPARSEMEM_ENABLE
1631	def_bool y
1632	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1633	select SPARSEMEM_STATIC if X86_32
1634	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1635
1636config ARCH_SPARSEMEM_DEFAULT
1637	def_bool X86_64 || (NUMA && X86_32)
1638
1639config ARCH_SELECT_MEMORY_MODEL
1640	def_bool y
1641	depends on ARCH_SPARSEMEM_ENABLE
1642
1643config ARCH_MEMORY_PROBE
1644	bool "Enable sysfs memory/probe interface"
1645	depends on X86_64 && MEMORY_HOTPLUG
1646	help
1647	  This option enables a sysfs memory/probe interface for testing.
1648	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1649	  If you are unsure how to answer this question, answer N.
1650
1651config ARCH_PROC_KCORE_TEXT
1652	def_bool y
1653	depends on X86_64 && PROC_KCORE
1654
1655config ILLEGAL_POINTER_VALUE
1656       hex
1657       default 0 if X86_32
1658       default 0xdead000000000000 if X86_64
1659
1660config X86_PMEM_LEGACY_DEVICE
1661	bool
1662
1663config X86_PMEM_LEGACY
1664	tristate "Support non-standard NVDIMMs and ADR protected memory"
1665	depends on PHYS_ADDR_T_64BIT
1666	depends on BLK_DEV
1667	select X86_PMEM_LEGACY_DEVICE
1668	select LIBNVDIMM
1669	help
1670	  Treat memory marked using the non-standard e820 type of 12 as used
1671	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1672	  The kernel will offer these regions to the 'pmem' driver so
1673	  they can be used for persistent storage.
1674
1675	  Say Y if unsure.
1676
1677config HIGHPTE
1678	bool "Allocate 3rd-level pagetables from highmem"
1679	depends on HIGHMEM
1680	---help---
1681	  The VM uses one page table entry for each page of physical memory.
1682	  For systems with a lot of RAM, this can be wasteful of precious
1683	  low memory.  Setting this option will put user-space page table
1684	  entries in high memory.
1685
1686config X86_CHECK_BIOS_CORRUPTION
1687	bool "Check for low memory corruption"
1688	---help---
1689	  Periodically check for memory corruption in low memory, which
1690	  is suspected to be caused by BIOS.  Even when enabled in the
1691	  configuration, it is disabled at runtime.  Enable it by
1692	  setting "memory_corruption_check=1" on the kernel command
1693	  line.  By default it scans the low 64k of memory every 60
1694	  seconds; see the memory_corruption_check_size and
1695	  memory_corruption_check_period parameters in
1696	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1697
1698	  When enabled with the default parameters, this option has
1699	  almost no overhead, as it reserves a relatively small amount
1700	  of memory and scans it infrequently.  It both detects corruption
1701	  and prevents it from affecting the running system.
1702
1703	  It is, however, intended as a diagnostic tool; if repeatable
1704	  BIOS-originated corruption always affects the same memory,
1705	  you can use memmap= to prevent the kernel from using that
1706	  memory.
1707
1708config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1709	bool "Set the default setting of memory_corruption_check"
1710	depends on X86_CHECK_BIOS_CORRUPTION
1711	default y
1712	---help---
1713	  Set whether the default state of memory_corruption_check is
1714	  on or off.
1715
1716config X86_RESERVE_LOW
1717	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1718	default 64
1719	range 4 640
1720	---help---
1721	  Specify the amount of low memory to reserve for the BIOS.
1722
1723	  The first page contains BIOS data structures that the kernel
1724	  must not use, so that page must always be reserved.
1725
1726	  By default we reserve the first 64K of physical RAM, as a
1727	  number of BIOSes are known to corrupt that memory range
1728	  during events such as suspend/resume or monitor cable
1729	  insertion, so it must not be used by the kernel.
1730
1731	  You can set this to 4 if you are absolutely sure that you
1732	  trust the BIOS to get all its memory reservations and usages
1733	  right.  If you know your BIOS have problems beyond the
1734	  default 64K area, you can set this to 640 to avoid using the
1735	  entire low memory range.
1736
1737	  If you have doubts about the BIOS (e.g. suspend/resume does
1738	  not work or there's kernel crashes after certain hardware
1739	  hotplug events) then you might want to enable
1740	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1741	  typical corruption patterns.
1742
1743	  Leave this to the default value of 64 if you are unsure.
1744
1745config MATH_EMULATION
1746	bool
1747	depends on MODIFY_LDT_SYSCALL
1748	prompt "Math emulation" if X86_32
1749	---help---
1750	  Linux can emulate a math coprocessor (used for floating point
1751	  operations) if you don't have one. 486DX and Pentium processors have
1752	  a math coprocessor built in, 486SX and 386 do not, unless you added
1753	  a 487DX or 387, respectively. (The messages during boot time can
1754	  give you some hints here ["man dmesg"].) Everyone needs either a
1755	  coprocessor or this emulation.
1756
1757	  If you don't have a math coprocessor, you need to say Y here; if you
1758	  say Y here even though you have a coprocessor, the coprocessor will
1759	  be used nevertheless. (This behavior can be changed with the kernel
1760	  command line option "no387", which comes handy if your coprocessor
1761	  is broken. Try "man bootparam" or see the documentation of your boot
1762	  loader (lilo or loadlin) about how to pass options to the kernel at
1763	  boot time.) This means that it is a good idea to say Y here if you
1764	  intend to use this kernel on different machines.
1765
1766	  More information about the internals of the Linux math coprocessor
1767	  emulation can be found in <file:arch/x86/math-emu/README>.
1768
1769	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1770	  kernel, it won't hurt.
1771
1772config MTRR
1773	def_bool y
1774	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1775	---help---
1776	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1777	  the Memory Type Range Registers (MTRRs) may be used to control
1778	  processor access to memory ranges. This is most useful if you have
1779	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1780	  allows bus write transfers to be combined into a larger transfer
1781	  before bursting over the PCI/AGP bus. This can increase performance
1782	  of image write operations 2.5 times or more. Saying Y here creates a
1783	  /proc/mtrr file which may be used to manipulate your processor's
1784	  MTRRs. Typically the X server should use this.
1785
1786	  This code has a reasonably generic interface so that similar
1787	  control registers on other processors can be easily supported
1788	  as well:
1789
1790	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1791	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1792	  these, the ARRs are used to emulate the MTRRs.
1793	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1794	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1795	  write-combining. All of these processors are supported by this code
1796	  and it makes sense to say Y here if you have one of them.
1797
1798	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1799	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1800	  can lead to all sorts of problems, so it's good to say Y here.
1801
1802	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1803	  just add about 9 KB to your kernel.
1804
1805	  See <file:Documentation/x86/mtrr.rst> for more information.
1806
1807config MTRR_SANITIZER
1808	def_bool y
1809	prompt "MTRR cleanup support"
1810	depends on MTRR
1811	---help---
1812	  Convert MTRR layout from continuous to discrete, so X drivers can
1813	  add writeback entries.
1814
1815	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1816	  The largest mtrr entry size for a continuous block can be set with
1817	  mtrr_chunk_size.
1818
1819	  If unsure, say Y.
1820
1821config MTRR_SANITIZER_ENABLE_DEFAULT
1822	int "MTRR cleanup enable value (0-1)"
1823	range 0 1
1824	default "0"
1825	depends on MTRR_SANITIZER
1826	---help---
1827	  Enable mtrr cleanup default value
1828
1829config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1830	int "MTRR cleanup spare reg num (0-7)"
1831	range 0 7
1832	default "1"
1833	depends on MTRR_SANITIZER
1834	---help---
1835	  mtrr cleanup spare entries default, it can be changed via
1836	  mtrr_spare_reg_nr=N on the kernel command line.
1837
1838config X86_PAT
1839	def_bool y
1840	prompt "x86 PAT support" if EXPERT
1841	depends on MTRR
1842	---help---
1843	  Use PAT attributes to setup page level cache control.
1844
1845	  PATs are the modern equivalents of MTRRs and are much more
1846	  flexible than MTRRs.
1847
1848	  Say N here if you see bootup problems (boot crash, boot hang,
1849	  spontaneous reboots) or a non-working video driver.
1850
1851	  If unsure, say Y.
1852
1853config ARCH_USES_PG_UNCACHED
1854	def_bool y
1855	depends on X86_PAT
1856
1857config ARCH_RANDOM
1858	def_bool y
1859	prompt "x86 architectural random number generator" if EXPERT
1860	---help---
1861	  Enable the x86 architectural RDRAND instruction
1862	  (Intel Bull Mountain technology) to generate random numbers.
1863	  If supported, this is a high bandwidth, cryptographically
1864	  secure hardware random number generator.
1865
1866config X86_SMAP
1867	def_bool y
1868	prompt "Supervisor Mode Access Prevention" if EXPERT
1869	---help---
1870	  Supervisor Mode Access Prevention (SMAP) is a security
1871	  feature in newer Intel processors.  There is a small
1872	  performance cost if this enabled and turned on; there is
1873	  also a small increase in the kernel size if this is enabled.
1874
1875	  If unsure, say Y.
1876
1877config X86_INTEL_UMIP
1878	def_bool y
1879	depends on CPU_SUP_INTEL
1880	prompt "Intel User Mode Instruction Prevention" if EXPERT
1881	---help---
1882	  The User Mode Instruction Prevention (UMIP) is a security
1883	  feature in newer Intel processors. If enabled, a general
1884	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1885	  or STR instructions are executed in user mode. These instructions
1886	  unnecessarily expose information about the hardware state.
1887
1888	  The vast majority of applications do not use these instructions.
1889	  For the very few that do, software emulation is provided in
1890	  specific cases in protected and virtual-8086 modes. Emulated
1891	  results are dummy.
1892
1893config X86_INTEL_MPX
1894	prompt "Intel MPX (Memory Protection Extensions)"
1895	def_bool n
1896	# Note: only available in 64-bit mode due to VMA flags shortage
1897	depends on CPU_SUP_INTEL && X86_64
1898	select ARCH_USES_HIGH_VMA_FLAGS
1899	---help---
1900	  MPX provides hardware features that can be used in
1901	  conjunction with compiler-instrumented code to check
1902	  memory references.  It is designed to detect buffer
1903	  overflow or underflow bugs.
1904
1905	  This option enables running applications which are
1906	  instrumented or otherwise use MPX.  It does not use MPX
1907	  itself inside the kernel or to protect the kernel
1908	  against bad memory references.
1909
1910	  Enabling this option will make the kernel larger:
1911	  ~8k of kernel text and 36 bytes of data on a 64-bit
1912	  defconfig.  It adds a long to the 'mm_struct' which
1913	  will increase the kernel memory overhead of each
1914	  process and adds some branches to paths used during
1915	  exec() and munmap().
1916
1917	  For details, see Documentation/x86/intel_mpx.rst
1918
1919	  If unsure, say N.
1920
1921config X86_INTEL_MEMORY_PROTECTION_KEYS
1922	prompt "Intel Memory Protection Keys"
1923	def_bool y
1924	# Note: only available in 64-bit mode
1925	depends on CPU_SUP_INTEL && X86_64
1926	select ARCH_USES_HIGH_VMA_FLAGS
1927	select ARCH_HAS_PKEYS
1928	---help---
1929	  Memory Protection Keys provides a mechanism for enforcing
1930	  page-based protections, but without requiring modification of the
1931	  page tables when an application changes protection domains.
1932
1933	  For details, see Documentation/core-api/protection-keys.rst
1934
1935	  If unsure, say y.
1936
1937config EFI
1938	bool "EFI runtime service support"
1939	depends on ACPI
1940	select UCS2_STRING
1941	select EFI_RUNTIME_WRAPPERS
1942	---help---
1943	  This enables the kernel to use EFI runtime services that are
1944	  available (such as the EFI variable services).
1945
1946	  This option is only useful on systems that have EFI firmware.
1947	  In addition, you should use the latest ELILO loader available
1948	  at <http://elilo.sourceforge.net> in order to take advantage
1949	  of EFI runtime services. However, even with this option, the
1950	  resultant kernel should continue to boot on existing non-EFI
1951	  platforms.
1952
1953config EFI_STUB
1954       bool "EFI stub support"
1955       depends on EFI && !X86_USE_3DNOW
1956       select RELOCATABLE
1957       ---help---
1958          This kernel feature allows a bzImage to be loaded directly
1959	  by EFI firmware without the use of a bootloader.
1960
1961	  See Documentation/admin-guide/efi-stub.rst for more information.
1962
1963config EFI_MIXED
1964	bool "EFI mixed-mode support"
1965	depends on EFI_STUB && X86_64
1966	---help---
1967	   Enabling this feature allows a 64-bit kernel to be booted
1968	   on a 32-bit firmware, provided that your CPU supports 64-bit
1969	   mode.
1970
1971	   Note that it is not possible to boot a mixed-mode enabled
1972	   kernel via the EFI boot stub - a bootloader that supports
1973	   the EFI handover protocol must be used.
1974
1975	   If unsure, say N.
1976
1977config SECCOMP
1978	def_bool y
1979	prompt "Enable seccomp to safely compute untrusted bytecode"
1980	---help---
1981	  This kernel feature is useful for number crunching applications
1982	  that may need to compute untrusted bytecode during their
1983	  execution. By using pipes or other transports made available to
1984	  the process as file descriptors supporting the read/write
1985	  syscalls, it's possible to isolate those applications in
1986	  their own address space using seccomp. Once seccomp is
1987	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1988	  and the task is only allowed to execute a few safe syscalls
1989	  defined by each seccomp mode.
1990
1991	  If unsure, say Y. Only embedded should say N here.
1992
1993source "kernel/Kconfig.hz"
1994
1995config KEXEC
1996	bool "kexec system call"
1997	select KEXEC_CORE
1998	---help---
1999	  kexec is a system call that implements the ability to shutdown your
2000	  current kernel, and to start another kernel.  It is like a reboot
2001	  but it is independent of the system firmware.   And like a reboot
2002	  you can start any kernel with it, not just Linux.
2003
2004	  The name comes from the similarity to the exec system call.
2005
2006	  It is an ongoing process to be certain the hardware in a machine
2007	  is properly shutdown, so do not be surprised if this code does not
2008	  initially work for you.  As of this writing the exact hardware
2009	  interface is strongly in flux, so no good recommendation can be
2010	  made.
2011
2012config KEXEC_FILE
2013	bool "kexec file based system call"
2014	select KEXEC_CORE
2015	select BUILD_BIN2C
2016	depends on X86_64
2017	depends on CRYPTO=y
2018	depends on CRYPTO_SHA256=y
2019	---help---
2020	  This is new version of kexec system call. This system call is
2021	  file based and takes file descriptors as system call argument
2022	  for kernel and initramfs as opposed to list of segments as
2023	  accepted by previous system call.
2024
2025config ARCH_HAS_KEXEC_PURGATORY
2026	def_bool KEXEC_FILE
2027
2028config KEXEC_VERIFY_SIG
2029	bool "Verify kernel signature during kexec_file_load() syscall"
2030	depends on KEXEC_FILE
2031	---help---
2032	  This option makes kernel signature verification mandatory for
2033	  the kexec_file_load() syscall.
2034
2035	  In addition to that option, you need to enable signature
2036	  verification for the corresponding kernel image type being
2037	  loaded in order for this to work.
2038
2039config KEXEC_BZIMAGE_VERIFY_SIG
2040	bool "Enable bzImage signature verification support"
2041	depends on KEXEC_VERIFY_SIG
2042	depends on SIGNED_PE_FILE_VERIFICATION
2043	select SYSTEM_TRUSTED_KEYRING
2044	---help---
2045	  Enable bzImage signature verification support.
2046
2047config CRASH_DUMP
2048	bool "kernel crash dumps"
2049	depends on X86_64 || (X86_32 && HIGHMEM)
2050	---help---
2051	  Generate crash dump after being started by kexec.
2052	  This should be normally only set in special crash dump kernels
2053	  which are loaded in the main kernel with kexec-tools into
2054	  a specially reserved region and then later executed after
2055	  a crash by kdump/kexec. The crash dump kernel must be compiled
2056	  to a memory address not used by the main kernel or BIOS using
2057	  PHYSICAL_START, or it must be built as a relocatable image
2058	  (CONFIG_RELOCATABLE=y).
2059	  For more details see Documentation/admin-guide/kdump/kdump.rst
2060
2061config KEXEC_JUMP
2062	bool "kexec jump"
2063	depends on KEXEC && HIBERNATION
2064	---help---
2065	  Jump between original kernel and kexeced kernel and invoke
2066	  code in physical address mode via KEXEC
2067
2068config PHYSICAL_START
2069	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2070	default "0x1000000"
2071	---help---
2072	  This gives the physical address where the kernel is loaded.
2073
2074	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2075	  bzImage will decompress itself to above physical address and
2076	  run from there. Otherwise, bzImage will run from the address where
2077	  it has been loaded by the boot loader and will ignore above physical
2078	  address.
2079
2080	  In normal kdump cases one does not have to set/change this option
2081	  as now bzImage can be compiled as a completely relocatable image
2082	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2083	  address. This option is mainly useful for the folks who don't want
2084	  to use a bzImage for capturing the crash dump and want to use a
2085	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2086	  to be specifically compiled to run from a specific memory area
2087	  (normally a reserved region) and this option comes handy.
2088
2089	  So if you are using bzImage for capturing the crash dump,
2090	  leave the value here unchanged to 0x1000000 and set
2091	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2092	  for capturing the crash dump change this value to start of
2093	  the reserved region.  In other words, it can be set based on
2094	  the "X" value as specified in the "crashkernel=YM@XM"
2095	  command line boot parameter passed to the panic-ed
2096	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2097	  for more details about crash dumps.
2098
2099	  Usage of bzImage for capturing the crash dump is recommended as
2100	  one does not have to build two kernels. Same kernel can be used
2101	  as production kernel and capture kernel. Above option should have
2102	  gone away after relocatable bzImage support is introduced. But it
2103	  is present because there are users out there who continue to use
2104	  vmlinux for dump capture. This option should go away down the
2105	  line.
2106
2107	  Don't change this unless you know what you are doing.
2108
2109config RELOCATABLE
2110	bool "Build a relocatable kernel"
2111	default y
2112	---help---
2113	  This builds a kernel image that retains relocation information
2114	  so it can be loaded someplace besides the default 1MB.
2115	  The relocations tend to make the kernel binary about 10% larger,
2116	  but are discarded at runtime.
2117
2118	  One use is for the kexec on panic case where the recovery kernel
2119	  must live at a different physical address than the primary
2120	  kernel.
2121
2122	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2123	  it has been loaded at and the compile time physical address
2124	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2125
2126config RANDOMIZE_BASE
2127	bool "Randomize the address of the kernel image (KASLR)"
2128	depends on RELOCATABLE
2129	default y
2130	---help---
2131	  In support of Kernel Address Space Layout Randomization (KASLR),
2132	  this randomizes the physical address at which the kernel image
2133	  is decompressed and the virtual address where the kernel
2134	  image is mapped, as a security feature that deters exploit
2135	  attempts relying on knowledge of the location of kernel
2136	  code internals.
2137
2138	  On 64-bit, the kernel physical and virtual addresses are
2139	  randomized separately. The physical address will be anywhere
2140	  between 16MB and the top of physical memory (up to 64TB). The
2141	  virtual address will be randomized from 16MB up to 1GB (9 bits
2142	  of entropy). Note that this also reduces the memory space
2143	  available to kernel modules from 1.5GB to 1GB.
2144
2145	  On 32-bit, the kernel physical and virtual addresses are
2146	  randomized together. They will be randomized from 16MB up to
2147	  512MB (8 bits of entropy).
2148
2149	  Entropy is generated using the RDRAND instruction if it is
2150	  supported. If RDTSC is supported, its value is mixed into
2151	  the entropy pool as well. If neither RDRAND nor RDTSC are
2152	  supported, then entropy is read from the i8254 timer. The
2153	  usable entropy is limited by the kernel being built using
2154	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2155	  minimum of 2MB. As a result, only 10 bits of entropy are
2156	  theoretically possible, but the implementations are further
2157	  limited due to memory layouts.
2158
2159	  If unsure, say Y.
2160
2161# Relocation on x86 needs some additional build support
2162config X86_NEED_RELOCS
2163	def_bool y
2164	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2165
2166config PHYSICAL_ALIGN
2167	hex "Alignment value to which kernel should be aligned"
2168	default "0x200000"
2169	range 0x2000 0x1000000 if X86_32
2170	range 0x200000 0x1000000 if X86_64
2171	---help---
2172	  This value puts the alignment restrictions on physical address
2173	  where kernel is loaded and run from. Kernel is compiled for an
2174	  address which meets above alignment restriction.
2175
2176	  If bootloader loads the kernel at a non-aligned address and
2177	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2178	  address aligned to above value and run from there.
2179
2180	  If bootloader loads the kernel at a non-aligned address and
2181	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2182	  load address and decompress itself to the address it has been
2183	  compiled for and run from there. The address for which kernel is
2184	  compiled already meets above alignment restrictions. Hence the
2185	  end result is that kernel runs from a physical address meeting
2186	  above alignment restrictions.
2187
2188	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2189	  this value must be a multiple of 0x200000.
2190
2191	  Don't change this unless you know what you are doing.
2192
2193config DYNAMIC_MEMORY_LAYOUT
2194	bool
2195	---help---
2196	  This option makes base addresses of vmalloc and vmemmap as well as
2197	  __PAGE_OFFSET movable during boot.
2198
2199config RANDOMIZE_MEMORY
2200	bool "Randomize the kernel memory sections"
2201	depends on X86_64
2202	depends on RANDOMIZE_BASE
2203	select DYNAMIC_MEMORY_LAYOUT
2204	default RANDOMIZE_BASE
2205	---help---
2206	   Randomizes the base virtual address of kernel memory sections
2207	   (physical memory mapping, vmalloc & vmemmap). This security feature
2208	   makes exploits relying on predictable memory locations less reliable.
2209
2210	   The order of allocations remains unchanged. Entropy is generated in
2211	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2212	   configuration have in average 30,000 different possible virtual
2213	   addresses for each memory section.
2214
2215	   If unsure, say Y.
2216
2217config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2218	hex "Physical memory mapping padding" if EXPERT
2219	depends on RANDOMIZE_MEMORY
2220	default "0xa" if MEMORY_HOTPLUG
2221	default "0x0"
2222	range 0x1 0x40 if MEMORY_HOTPLUG
2223	range 0x0 0x40
2224	---help---
2225	   Define the padding in terabytes added to the existing physical
2226	   memory size during kernel memory randomization. It is useful
2227	   for memory hotplug support but reduces the entropy available for
2228	   address randomization.
2229
2230	   If unsure, leave at the default value.
2231
2232config HOTPLUG_CPU
2233	def_bool y
2234	depends on SMP
2235
2236config BOOTPARAM_HOTPLUG_CPU0
2237	bool "Set default setting of cpu0_hotpluggable"
2238	depends on HOTPLUG_CPU
2239	---help---
2240	  Set whether default state of cpu0_hotpluggable is on or off.
2241
2242	  Say Y here to enable CPU0 hotplug by default. If this switch
2243	  is turned on, there is no need to give cpu0_hotplug kernel
2244	  parameter and the CPU0 hotplug feature is enabled by default.
2245
2246	  Please note: there are two known CPU0 dependencies if you want
2247	  to enable the CPU0 hotplug feature either by this switch or by
2248	  cpu0_hotplug kernel parameter.
2249
2250	  First, resume from hibernate or suspend always starts from CPU0.
2251	  So hibernate and suspend are prevented if CPU0 is offline.
2252
2253	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2254	  offline if any interrupt can not migrate out of CPU0. There may
2255	  be other CPU0 dependencies.
2256
2257	  Please make sure the dependencies are under your control before
2258	  you enable this feature.
2259
2260	  Say N if you don't want to enable CPU0 hotplug feature by default.
2261	  You still can enable the CPU0 hotplug feature at boot by kernel
2262	  parameter cpu0_hotplug.
2263
2264config DEBUG_HOTPLUG_CPU0
2265	def_bool n
2266	prompt "Debug CPU0 hotplug"
2267	depends on HOTPLUG_CPU
2268	---help---
2269	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2270	  soon as possible and boots up userspace with CPU0 offlined. User
2271	  can online CPU0 back after boot time.
2272
2273	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2274	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2275	  compilation or giving cpu0_hotplug kernel parameter at boot.
2276
2277	  If unsure, say N.
2278
2279config COMPAT_VDSO
2280	def_bool n
2281	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2282	depends on COMPAT_32
2283	---help---
2284	  Certain buggy versions of glibc will crash if they are
2285	  presented with a 32-bit vDSO that is not mapped at the address
2286	  indicated in its segment table.
2287
2288	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2289	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2290	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2291	  the only released version with the bug, but OpenSUSE 9
2292	  contains a buggy "glibc 2.3.2".
2293
2294	  The symptom of the bug is that everything crashes on startup, saying:
2295	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2296
2297	  Saying Y here changes the default value of the vdso32 boot
2298	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2299	  This works around the glibc bug but hurts performance.
2300
2301	  If unsure, say N: if you are compiling your own kernel, you
2302	  are unlikely to be using a buggy version of glibc.
2303
2304choice
2305	prompt "vsyscall table for legacy applications"
2306	depends on X86_64
2307	default LEGACY_VSYSCALL_XONLY
2308	help
2309	  Legacy user code that does not know how to find the vDSO expects
2310	  to be able to issue three syscalls by calling fixed addresses in
2311	  kernel space. Since this location is not randomized with ASLR,
2312	  it can be used to assist security vulnerability exploitation.
2313
2314	  This setting can be changed at boot time via the kernel command
2315	  line parameter vsyscall=[emulate|xonly|none].
2316
2317	  On a system with recent enough glibc (2.14 or newer) and no
2318	  static binaries, you can say None without a performance penalty
2319	  to improve security.
2320
2321	  If unsure, select "Emulate execution only".
2322
2323	config LEGACY_VSYSCALL_EMULATE
2324		bool "Full emulation"
2325		help
2326		  The kernel traps and emulates calls into the fixed vsyscall
2327		  address mapping. This makes the mapping non-executable, but
2328		  it still contains readable known contents, which could be
2329		  used in certain rare security vulnerability exploits. This
2330		  configuration is recommended when using legacy userspace
2331		  that still uses vsyscalls along with legacy binary
2332		  instrumentation tools that require code to be readable.
2333
2334		  An example of this type of legacy userspace is running
2335		  Pin on an old binary that still uses vsyscalls.
2336
2337	config LEGACY_VSYSCALL_XONLY
2338		bool "Emulate execution only"
2339		help
2340		  The kernel traps and emulates calls into the fixed vsyscall
2341		  address mapping and does not allow reads.  This
2342		  configuration is recommended when userspace might use the
2343		  legacy vsyscall area but support for legacy binary
2344		  instrumentation of legacy code is not needed.  It mitigates
2345		  certain uses of the vsyscall area as an ASLR-bypassing
2346		  buffer.
2347
2348	config LEGACY_VSYSCALL_NONE
2349		bool "None"
2350		help
2351		  There will be no vsyscall mapping at all. This will
2352		  eliminate any risk of ASLR bypass due to the vsyscall
2353		  fixed address mapping. Attempts to use the vsyscalls
2354		  will be reported to dmesg, so that either old or
2355		  malicious userspace programs can be identified.
2356
2357endchoice
2358
2359config CMDLINE_BOOL
2360	bool "Built-in kernel command line"
2361	---help---
2362	  Allow for specifying boot arguments to the kernel at
2363	  build time.  On some systems (e.g. embedded ones), it is
2364	  necessary or convenient to provide some or all of the
2365	  kernel boot arguments with the kernel itself (that is,
2366	  to not rely on the boot loader to provide them.)
2367
2368	  To compile command line arguments into the kernel,
2369	  set this option to 'Y', then fill in the
2370	  boot arguments in CONFIG_CMDLINE.
2371
2372	  Systems with fully functional boot loaders (i.e. non-embedded)
2373	  should leave this option set to 'N'.
2374
2375config CMDLINE
2376	string "Built-in kernel command string"
2377	depends on CMDLINE_BOOL
2378	default ""
2379	---help---
2380	  Enter arguments here that should be compiled into the kernel
2381	  image and used at boot time.  If the boot loader provides a
2382	  command line at boot time, it is appended to this string to
2383	  form the full kernel command line, when the system boots.
2384
2385	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2386	  change this behavior.
2387
2388	  In most cases, the command line (whether built-in or provided
2389	  by the boot loader) should specify the device for the root
2390	  file system.
2391
2392config CMDLINE_OVERRIDE
2393	bool "Built-in command line overrides boot loader arguments"
2394	depends on CMDLINE_BOOL
2395	---help---
2396	  Set this option to 'Y' to have the kernel ignore the boot loader
2397	  command line, and use ONLY the built-in command line.
2398
2399	  This is used to work around broken boot loaders.  This should
2400	  be set to 'N' under normal conditions.
2401
2402config MODIFY_LDT_SYSCALL
2403	bool "Enable the LDT (local descriptor table)" if EXPERT
2404	default y
2405	---help---
2406	  Linux can allow user programs to install a per-process x86
2407	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2408	  call.  This is required to run 16-bit or segmented code such as
2409	  DOSEMU or some Wine programs.  It is also used by some very old
2410	  threading libraries.
2411
2412	  Enabling this feature adds a small amount of overhead to
2413	  context switches and increases the low-level kernel attack
2414	  surface.  Disabling it removes the modify_ldt(2) system call.
2415
2416	  Saying 'N' here may make sense for embedded or server kernels.
2417
2418source "kernel/livepatch/Kconfig"
2419
2420endmenu
2421
2422config ARCH_HAS_ADD_PAGES
2423	def_bool y
2424	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2425
2426config ARCH_ENABLE_MEMORY_HOTPLUG
2427	def_bool y
2428	depends on X86_64 || (X86_32 && HIGHMEM)
2429
2430config ARCH_ENABLE_MEMORY_HOTREMOVE
2431	def_bool y
2432	depends on MEMORY_HOTPLUG
2433
2434config USE_PERCPU_NUMA_NODE_ID
2435	def_bool y
2436	depends on NUMA
2437
2438config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2439	def_bool y
2440	depends on X86_64 || X86_PAE
2441
2442config ARCH_ENABLE_HUGEPAGE_MIGRATION
2443	def_bool y
2444	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2445
2446config ARCH_ENABLE_THP_MIGRATION
2447	def_bool y
2448	depends on X86_64 && TRANSPARENT_HUGEPAGE
2449
2450menu "Power management and ACPI options"
2451
2452config ARCH_HIBERNATION_HEADER
2453	def_bool y
2454	depends on HIBERNATION
2455
2456source "kernel/power/Kconfig"
2457
2458source "drivers/acpi/Kconfig"
2459
2460source "drivers/sfi/Kconfig"
2461
2462config X86_APM_BOOT
2463	def_bool y
2464	depends on APM
2465
2466menuconfig APM
2467	tristate "APM (Advanced Power Management) BIOS support"
2468	depends on X86_32 && PM_SLEEP
2469	---help---
2470	  APM is a BIOS specification for saving power using several different
2471	  techniques. This is mostly useful for battery powered laptops with
2472	  APM compliant BIOSes. If you say Y here, the system time will be
2473	  reset after a RESUME operation, the /proc/apm device will provide
2474	  battery status information, and user-space programs will receive
2475	  notification of APM "events" (e.g. battery status change).
2476
2477	  If you select "Y" here, you can disable actual use of the APM
2478	  BIOS by passing the "apm=off" option to the kernel at boot time.
2479
2480	  Note that the APM support is almost completely disabled for
2481	  machines with more than one CPU.
2482
2483	  In order to use APM, you will need supporting software. For location
2484	  and more information, read <file:Documentation/power/apm-acpi.rst>
2485	  and the Battery Powered Linux mini-HOWTO, available from
2486	  <http://www.tldp.org/docs.html#howto>.
2487
2488	  This driver does not spin down disk drives (see the hdparm(8)
2489	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2490	  VESA-compliant "green" monitors.
2491
2492	  This driver does not support the TI 4000M TravelMate and the ACER
2493	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2494	  desktop machines also don't have compliant BIOSes, and this driver
2495	  may cause those machines to panic during the boot phase.
2496
2497	  Generally, if you don't have a battery in your machine, there isn't
2498	  much point in using this driver and you should say N. If you get
2499	  random kernel OOPSes or reboots that don't seem to be related to
2500	  anything, try disabling/enabling this option (or disabling/enabling
2501	  APM in your BIOS).
2502
2503	  Some other things you should try when experiencing seemingly random,
2504	  "weird" problems:
2505
2506	  1) make sure that you have enough swap space and that it is
2507	  enabled.
2508	  2) pass the "no-hlt" option to the kernel
2509	  3) switch on floating point emulation in the kernel and pass
2510	  the "no387" option to the kernel
2511	  4) pass the "floppy=nodma" option to the kernel
2512	  5) pass the "mem=4M" option to the kernel (thereby disabling
2513	  all but the first 4 MB of RAM)
2514	  6) make sure that the CPU is not over clocked.
2515	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2516	  8) disable the cache from your BIOS settings
2517	  9) install a fan for the video card or exchange video RAM
2518	  10) install a better fan for the CPU
2519	  11) exchange RAM chips
2520	  12) exchange the motherboard.
2521
2522	  To compile this driver as a module, choose M here: the
2523	  module will be called apm.
2524
2525if APM
2526
2527config APM_IGNORE_USER_SUSPEND
2528	bool "Ignore USER SUSPEND"
2529	---help---
2530	  This option will ignore USER SUSPEND requests. On machines with a
2531	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2532	  series notebooks, it is necessary to say Y because of a BIOS bug.
2533
2534config APM_DO_ENABLE
2535	bool "Enable PM at boot time"
2536	---help---
2537	  Enable APM features at boot time. From page 36 of the APM BIOS
2538	  specification: "When disabled, the APM BIOS does not automatically
2539	  power manage devices, enter the Standby State, enter the Suspend
2540	  State, or take power saving steps in response to CPU Idle calls."
2541	  This driver will make CPU Idle calls when Linux is idle (unless this
2542	  feature is turned off -- see "Do CPU IDLE calls", below). This
2543	  should always save battery power, but more complicated APM features
2544	  will be dependent on your BIOS implementation. You may need to turn
2545	  this option off if your computer hangs at boot time when using APM
2546	  support, or if it beeps continuously instead of suspending. Turn
2547	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2548	  T400CDT. This is off by default since most machines do fine without
2549	  this feature.
2550
2551config APM_CPU_IDLE
2552	depends on CPU_IDLE
2553	bool "Make CPU Idle calls when idle"
2554	---help---
2555	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2556	  On some machines, this can activate improved power savings, such as
2557	  a slowed CPU clock rate, when the machine is idle. These idle calls
2558	  are made after the idle loop has run for some length of time (e.g.,
2559	  333 mS). On some machines, this will cause a hang at boot time or
2560	  whenever the CPU becomes idle. (On machines with more than one CPU,
2561	  this option does nothing.)
2562
2563config APM_DISPLAY_BLANK
2564	bool "Enable console blanking using APM"
2565	---help---
2566	  Enable console blanking using the APM. Some laptops can use this to
2567	  turn off the LCD backlight when the screen blanker of the Linux
2568	  virtual console blanks the screen. Note that this is only used by
2569	  the virtual console screen blanker, and won't turn off the backlight
2570	  when using the X Window system. This also doesn't have anything to
2571	  do with your VESA-compliant power-saving monitor. Further, this
2572	  option doesn't work for all laptops -- it might not turn off your
2573	  backlight at all, or it might print a lot of errors to the console,
2574	  especially if you are using gpm.
2575
2576config APM_ALLOW_INTS
2577	bool "Allow interrupts during APM BIOS calls"
2578	---help---
2579	  Normally we disable external interrupts while we are making calls to
2580	  the APM BIOS as a measure to lessen the effects of a badly behaving
2581	  BIOS implementation.  The BIOS should reenable interrupts if it
2582	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2583	  many of the newer IBM Thinkpads.  If you experience hangs when you
2584	  suspend, try setting this to Y.  Otherwise, say N.
2585
2586endif # APM
2587
2588source "drivers/cpufreq/Kconfig"
2589
2590source "drivers/cpuidle/Kconfig"
2591
2592source "drivers/idle/Kconfig"
2593
2594endmenu
2595
2596
2597menu "Bus options (PCI etc.)"
2598
2599choice
2600	prompt "PCI access mode"
2601	depends on X86_32 && PCI
2602	default PCI_GOANY
2603	---help---
2604	  On PCI systems, the BIOS can be used to detect the PCI devices and
2605	  determine their configuration. However, some old PCI motherboards
2606	  have BIOS bugs and may crash if this is done. Also, some embedded
2607	  PCI-based systems don't have any BIOS at all. Linux can also try to
2608	  detect the PCI hardware directly without using the BIOS.
2609
2610	  With this option, you can specify how Linux should detect the
2611	  PCI devices. If you choose "BIOS", the BIOS will be used,
2612	  if you choose "Direct", the BIOS won't be used, and if you
2613	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2614	  If you choose "Any", the kernel will try MMCONFIG, then the
2615	  direct access method and falls back to the BIOS if that doesn't
2616	  work. If unsure, go with the default, which is "Any".
2617
2618config PCI_GOBIOS
2619	bool "BIOS"
2620
2621config PCI_GOMMCONFIG
2622	bool "MMConfig"
2623
2624config PCI_GODIRECT
2625	bool "Direct"
2626
2627config PCI_GOOLPC
2628	bool "OLPC XO-1"
2629	depends on OLPC
2630
2631config PCI_GOANY
2632	bool "Any"
2633
2634endchoice
2635
2636config PCI_BIOS
2637	def_bool y
2638	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2639
2640# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2641config PCI_DIRECT
2642	def_bool y
2643	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2644
2645config PCI_MMCONFIG
2646	bool "Support mmconfig PCI config space access" if X86_64
2647	default y
2648	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2649	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2650
2651config PCI_OLPC
2652	def_bool y
2653	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2654
2655config PCI_XEN
2656	def_bool y
2657	depends on PCI && XEN
2658	select SWIOTLB_XEN
2659
2660config MMCONF_FAM10H
2661	def_bool y
2662	depends on X86_64 && PCI_MMCONFIG && ACPI
2663
2664config PCI_CNB20LE_QUIRK
2665	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2666	depends on PCI
2667	help
2668	  Read the PCI windows out of the CNB20LE host bridge. This allows
2669	  PCI hotplug to work on systems with the CNB20LE chipset which do
2670	  not have ACPI.
2671
2672	  There's no public spec for this chipset, and this functionality
2673	  is known to be incomplete.
2674
2675	  You should say N unless you know you need this.
2676
2677config ISA_BUS
2678	bool "ISA bus support on modern systems" if EXPERT
2679	help
2680	  Expose ISA bus device drivers and options available for selection and
2681	  configuration. Enable this option if your target machine has an ISA
2682	  bus. ISA is an older system, displaced by PCI and newer bus
2683	  architectures -- if your target machine is modern, it probably does
2684	  not have an ISA bus.
2685
2686	  If unsure, say N.
2687
2688# x86_64 have no ISA slots, but can have ISA-style DMA.
2689config ISA_DMA_API
2690	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2691	default y
2692	help
2693	  Enables ISA-style DMA support for devices requiring such controllers.
2694	  If unsure, say Y.
2695
2696if X86_32
2697
2698config ISA
2699	bool "ISA support"
2700	---help---
2701	  Find out whether you have ISA slots on your motherboard.  ISA is the
2702	  name of a bus system, i.e. the way the CPU talks to the other stuff
2703	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2704	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2705	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2706
2707config SCx200
2708	tristate "NatSemi SCx200 support"
2709	---help---
2710	  This provides basic support for National Semiconductor's
2711	  (now AMD's) Geode processors.  The driver probes for the
2712	  PCI-IDs of several on-chip devices, so its a good dependency
2713	  for other scx200_* drivers.
2714
2715	  If compiled as a module, the driver is named scx200.
2716
2717config SCx200HR_TIMER
2718	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2719	depends on SCx200
2720	default y
2721	---help---
2722	  This driver provides a clocksource built upon the on-chip
2723	  27MHz high-resolution timer.  Its also a workaround for
2724	  NSC Geode SC-1100's buggy TSC, which loses time when the
2725	  processor goes idle (as is done by the scheduler).  The
2726	  other workaround is idle=poll boot option.
2727
2728config OLPC
2729	bool "One Laptop Per Child support"
2730	depends on !X86_PAE
2731	select GPIOLIB
2732	select OF
2733	select OF_PROMTREE
2734	select IRQ_DOMAIN
2735	select OLPC_EC
2736	---help---
2737	  Add support for detecting the unique features of the OLPC
2738	  XO hardware.
2739
2740config OLPC_XO1_PM
2741	bool "OLPC XO-1 Power Management"
2742	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2743	---help---
2744	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2745
2746config OLPC_XO1_RTC
2747	bool "OLPC XO-1 Real Time Clock"
2748	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2749	---help---
2750	  Add support for the XO-1 real time clock, which can be used as a
2751	  programmable wakeup source.
2752
2753config OLPC_XO1_SCI
2754	bool "OLPC XO-1 SCI extras"
2755	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2756	depends on INPUT=y
2757	select POWER_SUPPLY
2758	---help---
2759	  Add support for SCI-based features of the OLPC XO-1 laptop:
2760	   - EC-driven system wakeups
2761	   - Power button
2762	   - Ebook switch
2763	   - Lid switch
2764	   - AC adapter status updates
2765	   - Battery status updates
2766
2767config OLPC_XO15_SCI
2768	bool "OLPC XO-1.5 SCI extras"
2769	depends on OLPC && ACPI
2770	select POWER_SUPPLY
2771	---help---
2772	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2773	   - EC-driven system wakeups
2774	   - AC adapter status updates
2775	   - Battery status updates
2776
2777config ALIX
2778	bool "PCEngines ALIX System Support (LED setup)"
2779	select GPIOLIB
2780	---help---
2781	  This option enables system support for the PCEngines ALIX.
2782	  At present this just sets up LEDs for GPIO control on
2783	  ALIX2/3/6 boards.  However, other system specific setup should
2784	  get added here.
2785
2786	  Note: You must still enable the drivers for GPIO and LED support
2787	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2788
2789	  Note: You have to set alix.force=1 for boards with Award BIOS.
2790
2791config NET5501
2792	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2793	select GPIOLIB
2794	---help---
2795	  This option enables system support for the Soekris Engineering net5501.
2796
2797config GEOS
2798	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2799	select GPIOLIB
2800	depends on DMI
2801	---help---
2802	  This option enables system support for the Traverse Technologies GEOS.
2803
2804config TS5500
2805	bool "Technologic Systems TS-5500 platform support"
2806	depends on MELAN
2807	select CHECK_SIGNATURE
2808	select NEW_LEDS
2809	select LEDS_CLASS
2810	---help---
2811	  This option enables system support for the Technologic Systems TS-5500.
2812
2813endif # X86_32
2814
2815config AMD_NB
2816	def_bool y
2817	depends on CPU_SUP_AMD && PCI
2818
2819config X86_SYSFB
2820	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2821	help
2822	  Firmwares often provide initial graphics framebuffers so the BIOS,
2823	  bootloader or kernel can show basic video-output during boot for
2824	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2825	  Extensions and EFI-framebuffers for this, which are mostly limited
2826	  to x86.
2827	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2828	  framebuffers so the new generic system-framebuffer drivers can be
2829	  used on x86. If the framebuffer is not compatible with the generic
2830	  modes, it is advertised as fallback platform framebuffer so legacy
2831	  drivers like efifb, vesafb and uvesafb can pick it up.
2832	  If this option is not selected, all system framebuffers are always
2833	  marked as fallback platform framebuffers as usual.
2834
2835	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2836	  not be able to pick up generic system framebuffers if this option
2837	  is selected. You are highly encouraged to enable simplefb as
2838	  replacement if you select this option. simplefb can correctly deal
2839	  with generic system framebuffers. But you should still keep vesafb
2840	  and others enabled as fallback if a system framebuffer is
2841	  incompatible with simplefb.
2842
2843	  If unsure, say Y.
2844
2845endmenu
2846
2847
2848menu "Binary Emulations"
2849
2850config IA32_EMULATION
2851	bool "IA32 Emulation"
2852	depends on X86_64
2853	select ARCH_WANT_OLD_COMPAT_IPC
2854	select BINFMT_ELF
2855	select COMPAT_BINFMT_ELF
2856	select COMPAT_OLD_SIGACTION
2857	---help---
2858	  Include code to run legacy 32-bit programs under a
2859	  64-bit kernel. You should likely turn this on, unless you're
2860	  100% sure that you don't have any 32-bit programs left.
2861
2862config IA32_AOUT
2863	tristate "IA32 a.out support"
2864	depends on IA32_EMULATION
2865	depends on BROKEN
2866	---help---
2867	  Support old a.out binaries in the 32bit emulation.
2868
2869config X86_X32
2870	bool "x32 ABI for 64-bit mode"
2871	depends on X86_64
2872	---help---
2873	  Include code to run binaries for the x32 native 32-bit ABI
2874	  for 64-bit processors.  An x32 process gets access to the
2875	  full 64-bit register file and wide data path while leaving
2876	  pointers at 32 bits for smaller memory footprint.
2877
2878	  You will need a recent binutils (2.22 or later) with
2879	  elf32_x86_64 support enabled to compile a kernel with this
2880	  option set.
2881
2882config COMPAT_32
2883	def_bool y
2884	depends on IA32_EMULATION || X86_32
2885	select HAVE_UID16
2886	select OLD_SIGSUSPEND3
2887
2888config COMPAT
2889	def_bool y
2890	depends on IA32_EMULATION || X86_X32
2891
2892if COMPAT
2893config COMPAT_FOR_U64_ALIGNMENT
2894	def_bool y
2895
2896config SYSVIPC_COMPAT
2897	def_bool y
2898	depends on SYSVIPC
2899endif
2900
2901endmenu
2902
2903
2904config HAVE_ATOMIC_IOMAP
2905	def_bool y
2906	depends on X86_32
2907
2908config X86_DEV_DMA_OPS
2909	bool
2910
2911source "drivers/firmware/Kconfig"
2912
2913source "arch/x86/kvm/Kconfig"
2914