xref: /openbmc/linux/arch/x86/Kconfig (revision 78beef62)
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	select ARCH_CPUIDLE_HALTPOLL
798	default y
799	---help---
800	  This option enables various optimizations for running under the KVM
801	  hypervisor. It includes a paravirtualized clock, so that instead
802	  of relying on a PIT (or probably other) emulation by the
803	  underlying device model, the host provides the guest with
804	  timing infrastructure such as time of day, and system time
805
806config ARCH_CPUIDLE_HALTPOLL
807        def_bool n
808        prompt "Disable host haltpoll when loading haltpoll driver"
809        help
810	  If virtualized under KVM, disable host haltpoll.
811
812config PVH
813	bool "Support for running PVH guests"
814	---help---
815	  This option enables the PVH entry point for guest virtual machines
816	  as specified in the x86/HVM direct boot ABI.
817
818config KVM_DEBUG_FS
819	bool "Enable debug information for KVM Guests in debugfs"
820	depends on KVM_GUEST && DEBUG_FS
821	---help---
822	  This option enables collection of various statistics for KVM guest.
823	  Statistics are displayed in debugfs filesystem. Enabling this option
824	  may incur significant overhead.
825
826config PARAVIRT_TIME_ACCOUNTING
827	bool "Paravirtual steal time accounting"
828	depends on PARAVIRT
829	---help---
830	  Select this option to enable fine granularity task steal time
831	  accounting. Time spent executing other tasks in parallel with
832	  the current vCPU is discounted from the vCPU power. To account for
833	  that, there can be a small performance impact.
834
835	  If in doubt, say N here.
836
837config PARAVIRT_CLOCK
838	bool
839
840config JAILHOUSE_GUEST
841	bool "Jailhouse non-root cell support"
842	depends on X86_64 && PCI
843	select X86_PM_TIMER
844	---help---
845	  This option allows to run Linux as guest in a Jailhouse non-root
846	  cell. You can leave this option disabled if you only want to start
847	  Jailhouse and run Linux afterwards in the root cell.
848
849config ACRN_GUEST
850	bool "ACRN Guest support"
851	depends on X86_64
852	select X86_HV_CALLBACK_VECTOR
853	help
854	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
855	  a flexible, lightweight reference open-source hypervisor, built with
856	  real-time and safety-criticality in mind. It is built for embedded
857	  IOT with small footprint and real-time features. More details can be
858	  found in https://projectacrn.org/.
859
860endif #HYPERVISOR_GUEST
861
862source "arch/x86/Kconfig.cpu"
863
864config HPET_TIMER
865	def_bool X86_64
866	prompt "HPET Timer Support" if X86_32
867	---help---
868	  Use the IA-PC HPET (High Precision Event Timer) to manage
869	  time in preference to the PIT and RTC, if a HPET is
870	  present.
871	  HPET is the next generation timer replacing legacy 8254s.
872	  The HPET provides a stable time base on SMP
873	  systems, unlike the TSC, but it is more expensive to access,
874	  as it is off-chip.  The interface used is documented
875	  in the HPET spec, revision 1.
876
877	  You can safely choose Y here.  However, HPET will only be
878	  activated if the platform and the BIOS support this feature.
879	  Otherwise the 8254 will be used for timing services.
880
881	  Choose N to continue using the legacy 8254 timer.
882
883config HPET_EMULATE_RTC
884	def_bool y
885	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
886
887config APB_TIMER
888       def_bool y if X86_INTEL_MID
889       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
890       select DW_APB_TIMER
891       depends on X86_INTEL_MID && SFI
892       help
893         APB timer is the replacement for 8254, HPET on X86 MID platforms.
894         The APBT provides a stable time base on SMP
895         systems, unlike the TSC, but it is more expensive to access,
896         as it is off-chip. APB timers are always running regardless of CPU
897         C states, they are used as per CPU clockevent device when possible.
898
899# Mark as expert because too many people got it wrong.
900# The code disables itself when not needed.
901config DMI
902	default y
903	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
904	bool "Enable DMI scanning" if EXPERT
905	---help---
906	  Enabled scanning of DMI to identify machine quirks. Say Y
907	  here unless you have verified that your setup is not
908	  affected by entries in the DMI blacklist. Required by PNP
909	  BIOS code.
910
911config GART_IOMMU
912	bool "Old AMD GART IOMMU support"
913	select IOMMU_HELPER
914	select SWIOTLB
915	depends on X86_64 && PCI && AMD_NB
916	---help---
917	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
918	  GART based hardware IOMMUs.
919
920	  The GART supports full DMA access for devices with 32-bit access
921	  limitations, on systems with more than 3 GB. This is usually needed
922	  for USB, sound, many IDE/SATA chipsets and some other devices.
923
924	  Newer systems typically have a modern AMD IOMMU, supported via
925	  the CONFIG_AMD_IOMMU=y config option.
926
927	  In normal configurations this driver is only active when needed:
928	  there's more than 3 GB of memory and the system contains a
929	  32-bit limited device.
930
931	  If unsure, say Y.
932
933config CALGARY_IOMMU
934	bool "IBM Calgary IOMMU support"
935	select IOMMU_HELPER
936	select SWIOTLB
937	depends on X86_64 && PCI
938	---help---
939	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
940	  systems. Needed to run systems with more than 3GB of memory
941	  properly with 32-bit PCI devices that do not support DAC
942	  (Double Address Cycle). Calgary also supports bus level
943	  isolation, where all DMAs pass through the IOMMU.  This
944	  prevents them from going anywhere except their intended
945	  destination. This catches hard-to-find kernel bugs and
946	  mis-behaving drivers and devices that do not use the DMA-API
947	  properly to set up their DMA buffers.  The IOMMU can be
948	  turned off at boot time with the iommu=off parameter.
949	  Normally the kernel will make the right choice by itself.
950	  If unsure, say Y.
951
952config CALGARY_IOMMU_ENABLED_BY_DEFAULT
953	def_bool y
954	prompt "Should Calgary be enabled by default?"
955	depends on CALGARY_IOMMU
956	---help---
957	  Should Calgary be enabled by default? if you choose 'y', Calgary
958	  will be used (if it exists). If you choose 'n', Calgary will not be
959	  used even if it exists. If you choose 'n' and would like to use
960	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
961	  If unsure, say Y.
962
963config MAXSMP
964	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
965	depends on X86_64 && SMP && DEBUG_KERNEL
966	select CPUMASK_OFFSTACK
967	---help---
968	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
969	  If unsure, say N.
970
971#
972# The maximum number of CPUs supported:
973#
974# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
975# and which can be configured interactively in the
976# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
977#
978# The ranges are different on 32-bit and 64-bit kernels, depending on
979# hardware capabilities and scalability features of the kernel.
980#
981# ( If MAXSMP is enabled we just use the highest possible value and disable
982#   interactive configuration. )
983#
984
985config NR_CPUS_RANGE_BEGIN
986	int
987	default NR_CPUS_RANGE_END if MAXSMP
988	default    1 if !SMP
989	default    2
990
991config NR_CPUS_RANGE_END
992	int
993	depends on X86_32
994	default   64 if  SMP &&  X86_BIGSMP
995	default    8 if  SMP && !X86_BIGSMP
996	default    1 if !SMP
997
998config NR_CPUS_RANGE_END
999	int
1000	depends on X86_64
1001	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
1002	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
1003	default    1 if !SMP
1004
1005config NR_CPUS_DEFAULT
1006	int
1007	depends on X86_32
1008	default   32 if  X86_BIGSMP
1009	default    8 if  SMP
1010	default    1 if !SMP
1011
1012config NR_CPUS_DEFAULT
1013	int
1014	depends on X86_64
1015	default 8192 if  MAXSMP
1016	default   64 if  SMP
1017	default    1 if !SMP
1018
1019config NR_CPUS
1020	int "Maximum number of CPUs" if SMP && !MAXSMP
1021	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1022	default NR_CPUS_DEFAULT
1023	---help---
1024	  This allows you to specify the maximum number of CPUs which this
1025	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1026	  supported value is 8192, otherwise the maximum value is 512.  The
1027	  minimum value which makes sense is 2.
1028
1029	  This is purely to save memory: each supported CPU adds about 8KB
1030	  to the kernel image.
1031
1032config SCHED_SMT
1033	def_bool y if SMP
1034
1035config SCHED_MC
1036	def_bool y
1037	prompt "Multi-core scheduler support"
1038	depends on SMP
1039	---help---
1040	  Multi-core scheduler support improves the CPU scheduler's decision
1041	  making when dealing with multi-core CPU chips at a cost of slightly
1042	  increased overhead in some places. If unsure say N here.
1043
1044config SCHED_MC_PRIO
1045	bool "CPU core priorities scheduler support"
1046	depends on SCHED_MC && CPU_SUP_INTEL
1047	select X86_INTEL_PSTATE
1048	select CPU_FREQ
1049	default y
1050	---help---
1051	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1052	  core ordering determined at manufacturing time, which allows
1053	  certain cores to reach higher turbo frequencies (when running
1054	  single threaded workloads) than others.
1055
1056	  Enabling this kernel feature teaches the scheduler about
1057	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1058	  scheduler's CPU selection logic accordingly, so that higher
1059	  overall system performance can be achieved.
1060
1061	  This feature will have no effect on CPUs without this feature.
1062
1063	  If unsure say Y here.
1064
1065config UP_LATE_INIT
1066       def_bool y
1067       depends on !SMP && X86_LOCAL_APIC
1068
1069config X86_UP_APIC
1070	bool "Local APIC support on uniprocessors" if !PCI_MSI
1071	default PCI_MSI
1072	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1073	---help---
1074	  A local APIC (Advanced Programmable Interrupt Controller) is an
1075	  integrated interrupt controller in the CPU. If you have a single-CPU
1076	  system which has a processor with a local APIC, you can say Y here to
1077	  enable and use it. If you say Y here even though your machine doesn't
1078	  have a local APIC, then the kernel will still run with no slowdown at
1079	  all. The local APIC supports CPU-generated self-interrupts (timer,
1080	  performance counters), and the NMI watchdog which detects hard
1081	  lockups.
1082
1083config X86_UP_IOAPIC
1084	bool "IO-APIC support on uniprocessors"
1085	depends on X86_UP_APIC
1086	---help---
1087	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1088	  SMP-capable replacement for PC-style interrupt controllers. Most
1089	  SMP systems and many recent uniprocessor systems have one.
1090
1091	  If you have a single-CPU system with an IO-APIC, you can say Y here
1092	  to use it. If you say Y here even though your machine doesn't have
1093	  an IO-APIC, then the kernel will still run with no slowdown at all.
1094
1095config X86_LOCAL_APIC
1096	def_bool y
1097	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1098	select IRQ_DOMAIN_HIERARCHY
1099	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1100
1101config X86_IO_APIC
1102	def_bool y
1103	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1104
1105config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1106	bool "Reroute for broken boot IRQs"
1107	depends on X86_IO_APIC
1108	---help---
1109	  This option enables a workaround that fixes a source of
1110	  spurious interrupts. This is recommended when threaded
1111	  interrupt handling is used on systems where the generation of
1112	  superfluous "boot interrupts" cannot be disabled.
1113
1114	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1115	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1116	  kernel does during interrupt handling). On chipsets where this
1117	  boot IRQ generation cannot be disabled, this workaround keeps
1118	  the original IRQ line masked so that only the equivalent "boot
1119	  IRQ" is delivered to the CPUs. The workaround also tells the
1120	  kernel to set up the IRQ handler on the boot IRQ line. In this
1121	  way only one interrupt is delivered to the kernel. Otherwise
1122	  the spurious second interrupt may cause the kernel to bring
1123	  down (vital) interrupt lines.
1124
1125	  Only affects "broken" chipsets. Interrupt sharing may be
1126	  increased on these systems.
1127
1128config X86_MCE
1129	bool "Machine Check / overheating reporting"
1130	select GENERIC_ALLOCATOR
1131	default y
1132	---help---
1133	  Machine Check support allows the processor to notify the
1134	  kernel if it detects a problem (e.g. overheating, data corruption).
1135	  The action the kernel takes depends on the severity of the problem,
1136	  ranging from warning messages to halting the machine.
1137
1138config X86_MCELOG_LEGACY
1139	bool "Support for deprecated /dev/mcelog character device"
1140	depends on X86_MCE
1141	---help---
1142	  Enable support for /dev/mcelog which is needed by the old mcelog
1143	  userspace logging daemon. Consider switching to the new generation
1144	  rasdaemon solution.
1145
1146config X86_MCE_INTEL
1147	def_bool y
1148	prompt "Intel MCE features"
1149	depends on X86_MCE && X86_LOCAL_APIC
1150	---help---
1151	   Additional support for intel specific MCE features such as
1152	   the thermal monitor.
1153
1154config X86_MCE_AMD
1155	def_bool y
1156	prompt "AMD MCE features"
1157	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1158	---help---
1159	   Additional support for AMD specific MCE features such as
1160	   the DRAM Error Threshold.
1161
1162config X86_ANCIENT_MCE
1163	bool "Support for old Pentium 5 / WinChip machine checks"
1164	depends on X86_32 && X86_MCE
1165	---help---
1166	  Include support for machine check handling on old Pentium 5 or WinChip
1167	  systems. These typically need to be enabled explicitly on the command
1168	  line.
1169
1170config X86_MCE_THRESHOLD
1171	depends on X86_MCE_AMD || X86_MCE_INTEL
1172	def_bool y
1173
1174config X86_MCE_INJECT
1175	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1176	tristate "Machine check injector support"
1177	---help---
1178	  Provide support for injecting machine checks for testing purposes.
1179	  If you don't know what a machine check is and you don't do kernel
1180	  QA it is safe to say n.
1181
1182config X86_THERMAL_VECTOR
1183	def_bool y
1184	depends on X86_MCE_INTEL
1185
1186source "arch/x86/events/Kconfig"
1187
1188config X86_LEGACY_VM86
1189	bool "Legacy VM86 support"
1190	depends on X86_32
1191	---help---
1192	  This option allows user programs to put the CPU into V8086
1193	  mode, which is an 80286-era approximation of 16-bit real mode.
1194
1195	  Some very old versions of X and/or vbetool require this option
1196	  for user mode setting.  Similarly, DOSEMU will use it if
1197	  available to accelerate real mode DOS programs.  However, any
1198	  recent version of DOSEMU, X, or vbetool should be fully
1199	  functional even without kernel VM86 support, as they will all
1200	  fall back to software emulation. Nevertheless, if you are using
1201	  a 16-bit DOS program where 16-bit performance matters, vm86
1202	  mode might be faster than emulation and you might want to
1203	  enable this option.
1204
1205	  Note that any app that works on a 64-bit kernel is unlikely to
1206	  need this option, as 64-bit kernels don't, and can't, support
1207	  V8086 mode. This option is also unrelated to 16-bit protected
1208	  mode and is not needed to run most 16-bit programs under Wine.
1209
1210	  Enabling this option increases the complexity of the kernel
1211	  and slows down exception handling a tiny bit.
1212
1213	  If unsure, say N here.
1214
1215config VM86
1216       bool
1217       default X86_LEGACY_VM86
1218
1219config X86_16BIT
1220	bool "Enable support for 16-bit segments" if EXPERT
1221	default y
1222	depends on MODIFY_LDT_SYSCALL
1223	---help---
1224	  This option is required by programs like Wine to run 16-bit
1225	  protected mode legacy code on x86 processors.  Disabling
1226	  this option saves about 300 bytes on i386, or around 6K text
1227	  plus 16K runtime memory on x86-64,
1228
1229config X86_ESPFIX32
1230	def_bool y
1231	depends on X86_16BIT && X86_32
1232
1233config X86_ESPFIX64
1234	def_bool y
1235	depends on X86_16BIT && X86_64
1236
1237config X86_VSYSCALL_EMULATION
1238       bool "Enable vsyscall emulation" if EXPERT
1239       default y
1240       depends on X86_64
1241       ---help---
1242	 This enables emulation of the legacy vsyscall page.  Disabling
1243	 it is roughly equivalent to booting with vsyscall=none, except
1244	 that it will also disable the helpful warning if a program
1245	 tries to use a vsyscall.  With this option set to N, offending
1246	 programs will just segfault, citing addresses of the form
1247	 0xffffffffff600?00.
1248
1249	 This option is required by many programs built before 2013, and
1250	 care should be used even with newer programs if set to N.
1251
1252	 Disabling this option saves about 7K of kernel size and
1253	 possibly 4K of additional runtime pagetable memory.
1254
1255config TOSHIBA
1256	tristate "Toshiba Laptop support"
1257	depends on X86_32
1258	---help---
1259	  This adds a driver to safely access the System Management Mode of
1260	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1261	  not work on models with a Phoenix BIOS. The System Management Mode
1262	  is used to set the BIOS and power saving options on Toshiba portables.
1263
1264	  For information on utilities to make use of this driver see the
1265	  Toshiba Linux utilities web site at:
1266	  <http://www.buzzard.org.uk/toshiba/>.
1267
1268	  Say Y if you intend to run this kernel on a Toshiba portable.
1269	  Say N otherwise.
1270
1271config I8K
1272	tristate "Dell i8k legacy laptop support"
1273	select HWMON
1274	select SENSORS_DELL_SMM
1275	---help---
1276	  This option enables legacy /proc/i8k userspace interface in hwmon
1277	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1278	  temperature and allows controlling fan speeds of Dell laptops via
1279	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1280	  it reports also power and hotkey status. For fan speed control is
1281	  needed userspace package i8kutils.
1282
1283	  Say Y if you intend to run this kernel on old Dell laptops or want to
1284	  use userspace package i8kutils.
1285	  Say N otherwise.
1286
1287config X86_REBOOTFIXUPS
1288	bool "Enable X86 board specific fixups for reboot"
1289	depends on X86_32
1290	---help---
1291	  This enables chipset and/or board specific fixups to be done
1292	  in order to get reboot to work correctly. This is only needed on
1293	  some combinations of hardware and BIOS. The symptom, for which
1294	  this config is intended, is when reboot ends with a stalled/hung
1295	  system.
1296
1297	  Currently, the only fixup is for the Geode machines using
1298	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1299
1300	  Say Y if you want to enable the fixup. Currently, it's safe to
1301	  enable this option even if you don't need it.
1302	  Say N otherwise.
1303
1304config MICROCODE
1305	bool "CPU microcode loading support"
1306	default y
1307	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1308	select FW_LOADER
1309	---help---
1310	  If you say Y here, you will be able to update the microcode on
1311	  Intel and AMD processors. The Intel support is for the IA32 family,
1312	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1313	  AMD support is for families 0x10 and later. You will obviously need
1314	  the actual microcode binary data itself which is not shipped with
1315	  the Linux kernel.
1316
1317	  The preferred method to load microcode from a detached initrd is described
1318	  in Documentation/x86/microcode.rst. For that you need to enable
1319	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1320	  initrd for microcode blobs.
1321
1322	  In addition, you can build the microcode into the kernel. For that you
1323	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1324	  config option.
1325
1326config MICROCODE_INTEL
1327	bool "Intel microcode loading support"
1328	depends on MICROCODE
1329	default MICROCODE
1330	select FW_LOADER
1331	---help---
1332	  This options enables microcode patch loading support for Intel
1333	  processors.
1334
1335	  For the current Intel microcode data package go to
1336	  <https://downloadcenter.intel.com> and search for
1337	  'Linux Processor Microcode Data File'.
1338
1339config MICROCODE_AMD
1340	bool "AMD microcode loading support"
1341	depends on MICROCODE
1342	select FW_LOADER
1343	---help---
1344	  If you select this option, microcode patch loading support for AMD
1345	  processors will be enabled.
1346
1347config MICROCODE_OLD_INTERFACE
1348	bool "Ancient loading interface (DEPRECATED)"
1349	default n
1350	depends on MICROCODE
1351	---help---
1352	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1353	  which was used by userspace tools like iucode_tool and microcode.ctl.
1354	  It is inadequate because it runs too late to be able to properly
1355	  load microcode on a machine and it needs special tools. Instead, you
1356	  should've switched to the early loading method with the initrd or
1357	  builtin microcode by now: Documentation/x86/microcode.rst
1358
1359config X86_MSR
1360	tristate "/dev/cpu/*/msr - Model-specific register support"
1361	---help---
1362	  This device gives privileged processes access to the x86
1363	  Model-Specific Registers (MSRs).  It is a character device with
1364	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1365	  MSR accesses are directed to a specific CPU on multi-processor
1366	  systems.
1367
1368config X86_CPUID
1369	tristate "/dev/cpu/*/cpuid - CPU information support"
1370	---help---
1371	  This device gives processes access to the x86 CPUID instruction to
1372	  be executed on a specific processor.  It is a character device
1373	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1374	  /dev/cpu/31/cpuid.
1375
1376choice
1377	prompt "High Memory Support"
1378	default HIGHMEM4G
1379	depends on X86_32
1380
1381config NOHIGHMEM
1382	bool "off"
1383	---help---
1384	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1385	  However, the address space of 32-bit x86 processors is only 4
1386	  Gigabytes large. That means that, if you have a large amount of
1387	  physical memory, not all of it can be "permanently mapped" by the
1388	  kernel. The physical memory that's not permanently mapped is called
1389	  "high memory".
1390
1391	  If you are compiling a kernel which will never run on a machine with
1392	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1393	  choice and suitable for most users). This will result in a "3GB/1GB"
1394	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1395	  space and the remaining part of the 4GB virtual memory space is used
1396	  by the kernel to permanently map as much physical memory as
1397	  possible.
1398
1399	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1400	  answer "4GB" here.
1401
1402	  If more than 4 Gigabytes is used then answer "64GB" here. This
1403	  selection turns Intel PAE (Physical Address Extension) mode on.
1404	  PAE implements 3-level paging on IA32 processors. PAE is fully
1405	  supported by Linux, PAE mode is implemented on all recent Intel
1406	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1407	  then the kernel will not boot on CPUs that don't support PAE!
1408
1409	  The actual amount of total physical memory will either be
1410	  auto detected or can be forced by using a kernel command line option
1411	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1412	  your boot loader (lilo or loadlin) about how to pass options to the
1413	  kernel at boot time.)
1414
1415	  If unsure, say "off".
1416
1417config HIGHMEM4G
1418	bool "4GB"
1419	---help---
1420	  Select this if you have a 32-bit processor and between 1 and 4
1421	  gigabytes of physical RAM.
1422
1423config HIGHMEM64G
1424	bool "64GB"
1425	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1426	select X86_PAE
1427	---help---
1428	  Select this if you have a 32-bit processor and more than 4
1429	  gigabytes of physical RAM.
1430
1431endchoice
1432
1433choice
1434	prompt "Memory split" if EXPERT
1435	default VMSPLIT_3G
1436	depends on X86_32
1437	---help---
1438	  Select the desired split between kernel and user memory.
1439
1440	  If the address range available to the kernel is less than the
1441	  physical memory installed, the remaining memory will be available
1442	  as "high memory". Accessing high memory is a little more costly
1443	  than low memory, as it needs to be mapped into the kernel first.
1444	  Note that increasing the kernel address space limits the range
1445	  available to user programs, making the address space there
1446	  tighter.  Selecting anything other than the default 3G/1G split
1447	  will also likely make your kernel incompatible with binary-only
1448	  kernel modules.
1449
1450	  If you are not absolutely sure what you are doing, leave this
1451	  option alone!
1452
1453	config VMSPLIT_3G
1454		bool "3G/1G user/kernel split"
1455	config VMSPLIT_3G_OPT
1456		depends on !X86_PAE
1457		bool "3G/1G user/kernel split (for full 1G low memory)"
1458	config VMSPLIT_2G
1459		bool "2G/2G user/kernel split"
1460	config VMSPLIT_2G_OPT
1461		depends on !X86_PAE
1462		bool "2G/2G user/kernel split (for full 2G low memory)"
1463	config VMSPLIT_1G
1464		bool "1G/3G user/kernel split"
1465endchoice
1466
1467config PAGE_OFFSET
1468	hex
1469	default 0xB0000000 if VMSPLIT_3G_OPT
1470	default 0x80000000 if VMSPLIT_2G
1471	default 0x78000000 if VMSPLIT_2G_OPT
1472	default 0x40000000 if VMSPLIT_1G
1473	default 0xC0000000
1474	depends on X86_32
1475
1476config HIGHMEM
1477	def_bool y
1478	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1479
1480config X86_PAE
1481	bool "PAE (Physical Address Extension) Support"
1482	depends on X86_32 && !HIGHMEM4G
1483	select PHYS_ADDR_T_64BIT
1484	select SWIOTLB
1485	---help---
1486	  PAE is required for NX support, and furthermore enables
1487	  larger swapspace support for non-overcommit purposes. It
1488	  has the cost of more pagetable lookup overhead, and also
1489	  consumes more pagetable space per process.
1490
1491config X86_5LEVEL
1492	bool "Enable 5-level page tables support"
1493	select DYNAMIC_MEMORY_LAYOUT
1494	select SPARSEMEM_VMEMMAP
1495	depends on X86_64
1496	---help---
1497	  5-level paging enables access to larger address space:
1498	  upto 128 PiB of virtual address space and 4 PiB of
1499	  physical address space.
1500
1501	  It will be supported by future Intel CPUs.
1502
1503	  A kernel with the option enabled can be booted on machines that
1504	  support 4- or 5-level paging.
1505
1506	  See Documentation/x86/x86_64/5level-paging.rst for more
1507	  information.
1508
1509	  Say N if unsure.
1510
1511config X86_DIRECT_GBPAGES
1512	def_bool y
1513	depends on X86_64
1514	---help---
1515	  Certain kernel features effectively disable kernel
1516	  linear 1 GB mappings (even if the CPU otherwise
1517	  supports them), so don't confuse the user by printing
1518	  that we have them enabled.
1519
1520config X86_CPA_STATISTICS
1521	bool "Enable statistic for Change Page Attribute"
1522	depends on DEBUG_FS
1523	---help---
1524	  Expose statistics about the Change Page Attribute mechanims, which
1525	  helps to determine the effectiveness of preserving large and huge
1526	  page mappings when mapping protections are changed.
1527
1528config ARCH_HAS_MEM_ENCRYPT
1529	def_bool y
1530
1531config AMD_MEM_ENCRYPT
1532	bool "AMD Secure Memory Encryption (SME) support"
1533	depends on X86_64 && CPU_SUP_AMD
1534	select DYNAMIC_PHYSICAL_MASK
1535	select ARCH_USE_MEMREMAP_PROT
1536	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1537	---help---
1538	  Say yes to enable support for the encryption of system memory.
1539	  This requires an AMD processor that supports Secure Memory
1540	  Encryption (SME).
1541
1542config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1543	bool "Activate AMD Secure Memory Encryption (SME) by default"
1544	default y
1545	depends on AMD_MEM_ENCRYPT
1546	---help---
1547	  Say yes to have system memory encrypted by default if running on
1548	  an AMD processor that supports Secure Memory Encryption (SME).
1549
1550	  If set to Y, then the encryption of system memory can be
1551	  deactivated with the mem_encrypt=off command line option.
1552
1553	  If set to N, then the encryption of system memory can be
1554	  activated with the mem_encrypt=on command line option.
1555
1556# Common NUMA Features
1557config NUMA
1558	bool "Numa Memory Allocation and Scheduler Support"
1559	depends on SMP
1560	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1561	default y if X86_BIGSMP
1562	---help---
1563	  Enable NUMA (Non Uniform Memory Access) support.
1564
1565	  The kernel will try to allocate memory used by a CPU on the
1566	  local memory controller of the CPU and add some more
1567	  NUMA awareness to the kernel.
1568
1569	  For 64-bit this is recommended if the system is Intel Core i7
1570	  (or later), AMD Opteron, or EM64T NUMA.
1571
1572	  For 32-bit this is only needed if you boot a 32-bit
1573	  kernel on a 64-bit NUMA platform.
1574
1575	  Otherwise, you should say N.
1576
1577config AMD_NUMA
1578	def_bool y
1579	prompt "Old style AMD Opteron NUMA detection"
1580	depends on X86_64 && NUMA && PCI
1581	---help---
1582	  Enable AMD NUMA node topology detection.  You should say Y here if
1583	  you have a multi processor AMD system. This uses an old method to
1584	  read the NUMA configuration directly from the builtin Northbridge
1585	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1586	  which also takes priority if both are compiled in.
1587
1588config X86_64_ACPI_NUMA
1589	def_bool y
1590	prompt "ACPI NUMA detection"
1591	depends on X86_64 && NUMA && ACPI && PCI
1592	select ACPI_NUMA
1593	---help---
1594	  Enable ACPI SRAT based node topology detection.
1595
1596# Some NUMA nodes have memory ranges that span
1597# other nodes.  Even though a pfn is valid and
1598# between a node's start and end pfns, it may not
1599# reside on that node.  See memmap_init_zone()
1600# for details.
1601config NODES_SPAN_OTHER_NODES
1602	def_bool y
1603	depends on X86_64_ACPI_NUMA
1604
1605config NUMA_EMU
1606	bool "NUMA emulation"
1607	depends on NUMA
1608	---help---
1609	  Enable NUMA emulation. A flat machine will be split
1610	  into virtual nodes when booted with "numa=fake=N", where N is the
1611	  number of nodes. This is only useful for debugging.
1612
1613config NODES_SHIFT
1614	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1615	range 1 10
1616	default "10" if MAXSMP
1617	default "6" if X86_64
1618	default "3"
1619	depends on NEED_MULTIPLE_NODES
1620	---help---
1621	  Specify the maximum number of NUMA Nodes available on the target
1622	  system.  Increases memory reserved to accommodate various tables.
1623
1624config ARCH_HAVE_MEMORY_PRESENT
1625	def_bool y
1626	depends on X86_32 && DISCONTIGMEM
1627
1628config ARCH_FLATMEM_ENABLE
1629	def_bool y
1630	depends on X86_32 && !NUMA
1631
1632config ARCH_DISCONTIGMEM_ENABLE
1633	def_bool n
1634	depends on NUMA && X86_32
1635	depends on BROKEN
1636
1637config ARCH_SPARSEMEM_ENABLE
1638	def_bool y
1639	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1640	select SPARSEMEM_STATIC if X86_32
1641	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1642
1643config ARCH_SPARSEMEM_DEFAULT
1644	def_bool X86_64 || (NUMA && X86_32)
1645
1646config ARCH_SELECT_MEMORY_MODEL
1647	def_bool y
1648	depends on ARCH_SPARSEMEM_ENABLE
1649
1650config ARCH_MEMORY_PROBE
1651	bool "Enable sysfs memory/probe interface"
1652	depends on X86_64 && MEMORY_HOTPLUG
1653	help
1654	  This option enables a sysfs memory/probe interface for testing.
1655	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1656	  If you are unsure how to answer this question, answer N.
1657
1658config ARCH_PROC_KCORE_TEXT
1659	def_bool y
1660	depends on X86_64 && PROC_KCORE
1661
1662config ILLEGAL_POINTER_VALUE
1663       hex
1664       default 0 if X86_32
1665       default 0xdead000000000000 if X86_64
1666
1667config X86_PMEM_LEGACY_DEVICE
1668	bool
1669
1670config X86_PMEM_LEGACY
1671	tristate "Support non-standard NVDIMMs and ADR protected memory"
1672	depends on PHYS_ADDR_T_64BIT
1673	depends on BLK_DEV
1674	select X86_PMEM_LEGACY_DEVICE
1675	select LIBNVDIMM
1676	help
1677	  Treat memory marked using the non-standard e820 type of 12 as used
1678	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1679	  The kernel will offer these regions to the 'pmem' driver so
1680	  they can be used for persistent storage.
1681
1682	  Say Y if unsure.
1683
1684config HIGHPTE
1685	bool "Allocate 3rd-level pagetables from highmem"
1686	depends on HIGHMEM
1687	---help---
1688	  The VM uses one page table entry for each page of physical memory.
1689	  For systems with a lot of RAM, this can be wasteful of precious
1690	  low memory.  Setting this option will put user-space page table
1691	  entries in high memory.
1692
1693config X86_CHECK_BIOS_CORRUPTION
1694	bool "Check for low memory corruption"
1695	---help---
1696	  Periodically check for memory corruption in low memory, which
1697	  is suspected to be caused by BIOS.  Even when enabled in the
1698	  configuration, it is disabled at runtime.  Enable it by
1699	  setting "memory_corruption_check=1" on the kernel command
1700	  line.  By default it scans the low 64k of memory every 60
1701	  seconds; see the memory_corruption_check_size and
1702	  memory_corruption_check_period parameters in
1703	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1704
1705	  When enabled with the default parameters, this option has
1706	  almost no overhead, as it reserves a relatively small amount
1707	  of memory and scans it infrequently.  It both detects corruption
1708	  and prevents it from affecting the running system.
1709
1710	  It is, however, intended as a diagnostic tool; if repeatable
1711	  BIOS-originated corruption always affects the same memory,
1712	  you can use memmap= to prevent the kernel from using that
1713	  memory.
1714
1715config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1716	bool "Set the default setting of memory_corruption_check"
1717	depends on X86_CHECK_BIOS_CORRUPTION
1718	default y
1719	---help---
1720	  Set whether the default state of memory_corruption_check is
1721	  on or off.
1722
1723config X86_RESERVE_LOW
1724	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1725	default 64
1726	range 4 640
1727	---help---
1728	  Specify the amount of low memory to reserve for the BIOS.
1729
1730	  The first page contains BIOS data structures that the kernel
1731	  must not use, so that page must always be reserved.
1732
1733	  By default we reserve the first 64K of physical RAM, as a
1734	  number of BIOSes are known to corrupt that memory range
1735	  during events such as suspend/resume or monitor cable
1736	  insertion, so it must not be used by the kernel.
1737
1738	  You can set this to 4 if you are absolutely sure that you
1739	  trust the BIOS to get all its memory reservations and usages
1740	  right.  If you know your BIOS have problems beyond the
1741	  default 64K area, you can set this to 640 to avoid using the
1742	  entire low memory range.
1743
1744	  If you have doubts about the BIOS (e.g. suspend/resume does
1745	  not work or there's kernel crashes after certain hardware
1746	  hotplug events) then you might want to enable
1747	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1748	  typical corruption patterns.
1749
1750	  Leave this to the default value of 64 if you are unsure.
1751
1752config MATH_EMULATION
1753	bool
1754	depends on MODIFY_LDT_SYSCALL
1755	prompt "Math emulation" if X86_32
1756	---help---
1757	  Linux can emulate a math coprocessor (used for floating point
1758	  operations) if you don't have one. 486DX and Pentium processors have
1759	  a math coprocessor built in, 486SX and 386 do not, unless you added
1760	  a 487DX or 387, respectively. (The messages during boot time can
1761	  give you some hints here ["man dmesg"].) Everyone needs either a
1762	  coprocessor or this emulation.
1763
1764	  If you don't have a math coprocessor, you need to say Y here; if you
1765	  say Y here even though you have a coprocessor, the coprocessor will
1766	  be used nevertheless. (This behavior can be changed with the kernel
1767	  command line option "no387", which comes handy if your coprocessor
1768	  is broken. Try "man bootparam" or see the documentation of your boot
1769	  loader (lilo or loadlin) about how to pass options to the kernel at
1770	  boot time.) This means that it is a good idea to say Y here if you
1771	  intend to use this kernel on different machines.
1772
1773	  More information about the internals of the Linux math coprocessor
1774	  emulation can be found in <file:arch/x86/math-emu/README>.
1775
1776	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1777	  kernel, it won't hurt.
1778
1779config MTRR
1780	def_bool y
1781	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1782	---help---
1783	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1784	  the Memory Type Range Registers (MTRRs) may be used to control
1785	  processor access to memory ranges. This is most useful if you have
1786	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1787	  allows bus write transfers to be combined into a larger transfer
1788	  before bursting over the PCI/AGP bus. This can increase performance
1789	  of image write operations 2.5 times or more. Saying Y here creates a
1790	  /proc/mtrr file which may be used to manipulate your processor's
1791	  MTRRs. Typically the X server should use this.
1792
1793	  This code has a reasonably generic interface so that similar
1794	  control registers on other processors can be easily supported
1795	  as well:
1796
1797	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1798	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1799	  these, the ARRs are used to emulate the MTRRs.
1800	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1801	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1802	  write-combining. All of these processors are supported by this code
1803	  and it makes sense to say Y here if you have one of them.
1804
1805	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1806	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1807	  can lead to all sorts of problems, so it's good to say Y here.
1808
1809	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1810	  just add about 9 KB to your kernel.
1811
1812	  See <file:Documentation/x86/mtrr.rst> for more information.
1813
1814config MTRR_SANITIZER
1815	def_bool y
1816	prompt "MTRR cleanup support"
1817	depends on MTRR
1818	---help---
1819	  Convert MTRR layout from continuous to discrete, so X drivers can
1820	  add writeback entries.
1821
1822	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1823	  The largest mtrr entry size for a continuous block can be set with
1824	  mtrr_chunk_size.
1825
1826	  If unsure, say Y.
1827
1828config MTRR_SANITIZER_ENABLE_DEFAULT
1829	int "MTRR cleanup enable value (0-1)"
1830	range 0 1
1831	default "0"
1832	depends on MTRR_SANITIZER
1833	---help---
1834	  Enable mtrr cleanup default value
1835
1836config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1837	int "MTRR cleanup spare reg num (0-7)"
1838	range 0 7
1839	default "1"
1840	depends on MTRR_SANITIZER
1841	---help---
1842	  mtrr cleanup spare entries default, it can be changed via
1843	  mtrr_spare_reg_nr=N on the kernel command line.
1844
1845config X86_PAT
1846	def_bool y
1847	prompt "x86 PAT support" if EXPERT
1848	depends on MTRR
1849	---help---
1850	  Use PAT attributes to setup page level cache control.
1851
1852	  PATs are the modern equivalents of MTRRs and are much more
1853	  flexible than MTRRs.
1854
1855	  Say N here if you see bootup problems (boot crash, boot hang,
1856	  spontaneous reboots) or a non-working video driver.
1857
1858	  If unsure, say Y.
1859
1860config ARCH_USES_PG_UNCACHED
1861	def_bool y
1862	depends on X86_PAT
1863
1864config ARCH_RANDOM
1865	def_bool y
1866	prompt "x86 architectural random number generator" if EXPERT
1867	---help---
1868	  Enable the x86 architectural RDRAND instruction
1869	  (Intel Bull Mountain technology) to generate random numbers.
1870	  If supported, this is a high bandwidth, cryptographically
1871	  secure hardware random number generator.
1872
1873config X86_SMAP
1874	def_bool y
1875	prompt "Supervisor Mode Access Prevention" if EXPERT
1876	---help---
1877	  Supervisor Mode Access Prevention (SMAP) is a security
1878	  feature in newer Intel processors.  There is a small
1879	  performance cost if this enabled and turned on; there is
1880	  also a small increase in the kernel size if this is enabled.
1881
1882	  If unsure, say Y.
1883
1884config X86_INTEL_UMIP
1885	def_bool y
1886	depends on CPU_SUP_INTEL
1887	prompt "Intel User Mode Instruction Prevention" if EXPERT
1888	---help---
1889	  The User Mode Instruction Prevention (UMIP) is a security
1890	  feature in newer Intel processors. If enabled, a general
1891	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1892	  or STR instructions are executed in user mode. These instructions
1893	  unnecessarily expose information about the hardware state.
1894
1895	  The vast majority of applications do not use these instructions.
1896	  For the very few that do, software emulation is provided in
1897	  specific cases in protected and virtual-8086 modes. Emulated
1898	  results are dummy.
1899
1900config X86_INTEL_MPX
1901	prompt "Intel MPX (Memory Protection Extensions)"
1902	def_bool n
1903	# Note: only available in 64-bit mode due to VMA flags shortage
1904	depends on CPU_SUP_INTEL && X86_64
1905	select ARCH_USES_HIGH_VMA_FLAGS
1906	---help---
1907	  MPX provides hardware features that can be used in
1908	  conjunction with compiler-instrumented code to check
1909	  memory references.  It is designed to detect buffer
1910	  overflow or underflow bugs.
1911
1912	  This option enables running applications which are
1913	  instrumented or otherwise use MPX.  It does not use MPX
1914	  itself inside the kernel or to protect the kernel
1915	  against bad memory references.
1916
1917	  Enabling this option will make the kernel larger:
1918	  ~8k of kernel text and 36 bytes of data on a 64-bit
1919	  defconfig.  It adds a long to the 'mm_struct' which
1920	  will increase the kernel memory overhead of each
1921	  process and adds some branches to paths used during
1922	  exec() and munmap().
1923
1924	  For details, see Documentation/x86/intel_mpx.rst
1925
1926	  If unsure, say N.
1927
1928config X86_INTEL_MEMORY_PROTECTION_KEYS
1929	prompt "Intel Memory Protection Keys"
1930	def_bool y
1931	# Note: only available in 64-bit mode
1932	depends on CPU_SUP_INTEL && X86_64
1933	select ARCH_USES_HIGH_VMA_FLAGS
1934	select ARCH_HAS_PKEYS
1935	---help---
1936	  Memory Protection Keys provides a mechanism for enforcing
1937	  page-based protections, but without requiring modification of the
1938	  page tables when an application changes protection domains.
1939
1940	  For details, see Documentation/core-api/protection-keys.rst
1941
1942	  If unsure, say y.
1943
1944config EFI
1945	bool "EFI runtime service support"
1946	depends on ACPI
1947	select UCS2_STRING
1948	select EFI_RUNTIME_WRAPPERS
1949	---help---
1950	  This enables the kernel to use EFI runtime services that are
1951	  available (such as the EFI variable services).
1952
1953	  This option is only useful on systems that have EFI firmware.
1954	  In addition, you should use the latest ELILO loader available
1955	  at <http://elilo.sourceforge.net> in order to take advantage
1956	  of EFI runtime services. However, even with this option, the
1957	  resultant kernel should continue to boot on existing non-EFI
1958	  platforms.
1959
1960config EFI_STUB
1961       bool "EFI stub support"
1962       depends on EFI && !X86_USE_3DNOW
1963       select RELOCATABLE
1964       ---help---
1965          This kernel feature allows a bzImage to be loaded directly
1966	  by EFI firmware without the use of a bootloader.
1967
1968	  See Documentation/admin-guide/efi-stub.rst for more information.
1969
1970config EFI_MIXED
1971	bool "EFI mixed-mode support"
1972	depends on EFI_STUB && X86_64
1973	---help---
1974	   Enabling this feature allows a 64-bit kernel to be booted
1975	   on a 32-bit firmware, provided that your CPU supports 64-bit
1976	   mode.
1977
1978	   Note that it is not possible to boot a mixed-mode enabled
1979	   kernel via the EFI boot stub - a bootloader that supports
1980	   the EFI handover protocol must be used.
1981
1982	   If unsure, say N.
1983
1984config SECCOMP
1985	def_bool y
1986	prompt "Enable seccomp to safely compute untrusted bytecode"
1987	---help---
1988	  This kernel feature is useful for number crunching applications
1989	  that may need to compute untrusted bytecode during their
1990	  execution. By using pipes or other transports made available to
1991	  the process as file descriptors supporting the read/write
1992	  syscalls, it's possible to isolate those applications in
1993	  their own address space using seccomp. Once seccomp is
1994	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1995	  and the task is only allowed to execute a few safe syscalls
1996	  defined by each seccomp mode.
1997
1998	  If unsure, say Y. Only embedded should say N here.
1999
2000source "kernel/Kconfig.hz"
2001
2002config KEXEC
2003	bool "kexec system call"
2004	select KEXEC_CORE
2005	---help---
2006	  kexec is a system call that implements the ability to shutdown your
2007	  current kernel, and to start another kernel.  It is like a reboot
2008	  but it is independent of the system firmware.   And like a reboot
2009	  you can start any kernel with it, not just Linux.
2010
2011	  The name comes from the similarity to the exec system call.
2012
2013	  It is an ongoing process to be certain the hardware in a machine
2014	  is properly shutdown, so do not be surprised if this code does not
2015	  initially work for you.  As of this writing the exact hardware
2016	  interface is strongly in flux, so no good recommendation can be
2017	  made.
2018
2019config KEXEC_FILE
2020	bool "kexec file based system call"
2021	select KEXEC_CORE
2022	select BUILD_BIN2C
2023	depends on X86_64
2024	depends on CRYPTO=y
2025	depends on CRYPTO_SHA256=y
2026	---help---
2027	  This is new version of kexec system call. This system call is
2028	  file based and takes file descriptors as system call argument
2029	  for kernel and initramfs as opposed to list of segments as
2030	  accepted by previous system call.
2031
2032config ARCH_HAS_KEXEC_PURGATORY
2033	def_bool KEXEC_FILE
2034
2035config KEXEC_VERIFY_SIG
2036	bool "Verify kernel signature during kexec_file_load() syscall"
2037	depends on KEXEC_FILE
2038	---help---
2039	  This option makes kernel signature verification mandatory for
2040	  the kexec_file_load() syscall.
2041
2042	  In addition to that option, you need to enable signature
2043	  verification for the corresponding kernel image type being
2044	  loaded in order for this to work.
2045
2046config KEXEC_BZIMAGE_VERIFY_SIG
2047	bool "Enable bzImage signature verification support"
2048	depends on KEXEC_VERIFY_SIG
2049	depends on SIGNED_PE_FILE_VERIFICATION
2050	select SYSTEM_TRUSTED_KEYRING
2051	---help---
2052	  Enable bzImage signature verification support.
2053
2054config CRASH_DUMP
2055	bool "kernel crash dumps"
2056	depends on X86_64 || (X86_32 && HIGHMEM)
2057	---help---
2058	  Generate crash dump after being started by kexec.
2059	  This should be normally only set in special crash dump kernels
2060	  which are loaded in the main kernel with kexec-tools into
2061	  a specially reserved region and then later executed after
2062	  a crash by kdump/kexec. The crash dump kernel must be compiled
2063	  to a memory address not used by the main kernel or BIOS using
2064	  PHYSICAL_START, or it must be built as a relocatable image
2065	  (CONFIG_RELOCATABLE=y).
2066	  For more details see Documentation/admin-guide/kdump/kdump.rst
2067
2068config KEXEC_JUMP
2069	bool "kexec jump"
2070	depends on KEXEC && HIBERNATION
2071	---help---
2072	  Jump between original kernel and kexeced kernel and invoke
2073	  code in physical address mode via KEXEC
2074
2075config PHYSICAL_START
2076	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2077	default "0x1000000"
2078	---help---
2079	  This gives the physical address where the kernel is loaded.
2080
2081	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2082	  bzImage will decompress itself to above physical address and
2083	  run from there. Otherwise, bzImage will run from the address where
2084	  it has been loaded by the boot loader and will ignore above physical
2085	  address.
2086
2087	  In normal kdump cases one does not have to set/change this option
2088	  as now bzImage can be compiled as a completely relocatable image
2089	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2090	  address. This option is mainly useful for the folks who don't want
2091	  to use a bzImage for capturing the crash dump and want to use a
2092	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2093	  to be specifically compiled to run from a specific memory area
2094	  (normally a reserved region) and this option comes handy.
2095
2096	  So if you are using bzImage for capturing the crash dump,
2097	  leave the value here unchanged to 0x1000000 and set
2098	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2099	  for capturing the crash dump change this value to start of
2100	  the reserved region.  In other words, it can be set based on
2101	  the "X" value as specified in the "crashkernel=YM@XM"
2102	  command line boot parameter passed to the panic-ed
2103	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2104	  for more details about crash dumps.
2105
2106	  Usage of bzImage for capturing the crash dump is recommended as
2107	  one does not have to build two kernels. Same kernel can be used
2108	  as production kernel and capture kernel. Above option should have
2109	  gone away after relocatable bzImage support is introduced. But it
2110	  is present because there are users out there who continue to use
2111	  vmlinux for dump capture. This option should go away down the
2112	  line.
2113
2114	  Don't change this unless you know what you are doing.
2115
2116config RELOCATABLE
2117	bool "Build a relocatable kernel"
2118	default y
2119	---help---
2120	  This builds a kernel image that retains relocation information
2121	  so it can be loaded someplace besides the default 1MB.
2122	  The relocations tend to make the kernel binary about 10% larger,
2123	  but are discarded at runtime.
2124
2125	  One use is for the kexec on panic case where the recovery kernel
2126	  must live at a different physical address than the primary
2127	  kernel.
2128
2129	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2130	  it has been loaded at and the compile time physical address
2131	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2132
2133config RANDOMIZE_BASE
2134	bool "Randomize the address of the kernel image (KASLR)"
2135	depends on RELOCATABLE
2136	default y
2137	---help---
2138	  In support of Kernel Address Space Layout Randomization (KASLR),
2139	  this randomizes the physical address at which the kernel image
2140	  is decompressed and the virtual address where the kernel
2141	  image is mapped, as a security feature that deters exploit
2142	  attempts relying on knowledge of the location of kernel
2143	  code internals.
2144
2145	  On 64-bit, the kernel physical and virtual addresses are
2146	  randomized separately. The physical address will be anywhere
2147	  between 16MB and the top of physical memory (up to 64TB). The
2148	  virtual address will be randomized from 16MB up to 1GB (9 bits
2149	  of entropy). Note that this also reduces the memory space
2150	  available to kernel modules from 1.5GB to 1GB.
2151
2152	  On 32-bit, the kernel physical and virtual addresses are
2153	  randomized together. They will be randomized from 16MB up to
2154	  512MB (8 bits of entropy).
2155
2156	  Entropy is generated using the RDRAND instruction if it is
2157	  supported. If RDTSC is supported, its value is mixed into
2158	  the entropy pool as well. If neither RDRAND nor RDTSC are
2159	  supported, then entropy is read from the i8254 timer. The
2160	  usable entropy is limited by the kernel being built using
2161	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2162	  minimum of 2MB. As a result, only 10 bits of entropy are
2163	  theoretically possible, but the implementations are further
2164	  limited due to memory layouts.
2165
2166	  If unsure, say Y.
2167
2168# Relocation on x86 needs some additional build support
2169config X86_NEED_RELOCS
2170	def_bool y
2171	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2172
2173config PHYSICAL_ALIGN
2174	hex "Alignment value to which kernel should be aligned"
2175	default "0x200000"
2176	range 0x2000 0x1000000 if X86_32
2177	range 0x200000 0x1000000 if X86_64
2178	---help---
2179	  This value puts the alignment restrictions on physical address
2180	  where kernel is loaded and run from. Kernel is compiled for an
2181	  address which meets above alignment restriction.
2182
2183	  If bootloader loads the kernel at a non-aligned address and
2184	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2185	  address aligned to above value and run from there.
2186
2187	  If bootloader loads the kernel at a non-aligned address and
2188	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2189	  load address and decompress itself to the address it has been
2190	  compiled for and run from there. The address for which kernel is
2191	  compiled already meets above alignment restrictions. Hence the
2192	  end result is that kernel runs from a physical address meeting
2193	  above alignment restrictions.
2194
2195	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2196	  this value must be a multiple of 0x200000.
2197
2198	  Don't change this unless you know what you are doing.
2199
2200config DYNAMIC_MEMORY_LAYOUT
2201	bool
2202	---help---
2203	  This option makes base addresses of vmalloc and vmemmap as well as
2204	  __PAGE_OFFSET movable during boot.
2205
2206config RANDOMIZE_MEMORY
2207	bool "Randomize the kernel memory sections"
2208	depends on X86_64
2209	depends on RANDOMIZE_BASE
2210	select DYNAMIC_MEMORY_LAYOUT
2211	default RANDOMIZE_BASE
2212	---help---
2213	   Randomizes the base virtual address of kernel memory sections
2214	   (physical memory mapping, vmalloc & vmemmap). This security feature
2215	   makes exploits relying on predictable memory locations less reliable.
2216
2217	   The order of allocations remains unchanged. Entropy is generated in
2218	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2219	   configuration have in average 30,000 different possible virtual
2220	   addresses for each memory section.
2221
2222	   If unsure, say Y.
2223
2224config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2225	hex "Physical memory mapping padding" if EXPERT
2226	depends on RANDOMIZE_MEMORY
2227	default "0xa" if MEMORY_HOTPLUG
2228	default "0x0"
2229	range 0x1 0x40 if MEMORY_HOTPLUG
2230	range 0x0 0x40
2231	---help---
2232	   Define the padding in terabytes added to the existing physical
2233	   memory size during kernel memory randomization. It is useful
2234	   for memory hotplug support but reduces the entropy available for
2235	   address randomization.
2236
2237	   If unsure, leave at the default value.
2238
2239config HOTPLUG_CPU
2240	def_bool y
2241	depends on SMP
2242
2243config BOOTPARAM_HOTPLUG_CPU0
2244	bool "Set default setting of cpu0_hotpluggable"
2245	depends on HOTPLUG_CPU
2246	---help---
2247	  Set whether default state of cpu0_hotpluggable is on or off.
2248
2249	  Say Y here to enable CPU0 hotplug by default. If this switch
2250	  is turned on, there is no need to give cpu0_hotplug kernel
2251	  parameter and the CPU0 hotplug feature is enabled by default.
2252
2253	  Please note: there are two known CPU0 dependencies if you want
2254	  to enable the CPU0 hotplug feature either by this switch or by
2255	  cpu0_hotplug kernel parameter.
2256
2257	  First, resume from hibernate or suspend always starts from CPU0.
2258	  So hibernate and suspend are prevented if CPU0 is offline.
2259
2260	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2261	  offline if any interrupt can not migrate out of CPU0. There may
2262	  be other CPU0 dependencies.
2263
2264	  Please make sure the dependencies are under your control before
2265	  you enable this feature.
2266
2267	  Say N if you don't want to enable CPU0 hotplug feature by default.
2268	  You still can enable the CPU0 hotplug feature at boot by kernel
2269	  parameter cpu0_hotplug.
2270
2271config DEBUG_HOTPLUG_CPU0
2272	def_bool n
2273	prompt "Debug CPU0 hotplug"
2274	depends on HOTPLUG_CPU
2275	---help---
2276	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2277	  soon as possible and boots up userspace with CPU0 offlined. User
2278	  can online CPU0 back after boot time.
2279
2280	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2281	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2282	  compilation or giving cpu0_hotplug kernel parameter at boot.
2283
2284	  If unsure, say N.
2285
2286config COMPAT_VDSO
2287	def_bool n
2288	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2289	depends on COMPAT_32
2290	---help---
2291	  Certain buggy versions of glibc will crash if they are
2292	  presented with a 32-bit vDSO that is not mapped at the address
2293	  indicated in its segment table.
2294
2295	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2296	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2297	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2298	  the only released version with the bug, but OpenSUSE 9
2299	  contains a buggy "glibc 2.3.2".
2300
2301	  The symptom of the bug is that everything crashes on startup, saying:
2302	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2303
2304	  Saying Y here changes the default value of the vdso32 boot
2305	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2306	  This works around the glibc bug but hurts performance.
2307
2308	  If unsure, say N: if you are compiling your own kernel, you
2309	  are unlikely to be using a buggy version of glibc.
2310
2311choice
2312	prompt "vsyscall table for legacy applications"
2313	depends on X86_64
2314	default LEGACY_VSYSCALL_XONLY
2315	help
2316	  Legacy user code that does not know how to find the vDSO expects
2317	  to be able to issue three syscalls by calling fixed addresses in
2318	  kernel space. Since this location is not randomized with ASLR,
2319	  it can be used to assist security vulnerability exploitation.
2320
2321	  This setting can be changed at boot time via the kernel command
2322	  line parameter vsyscall=[emulate|xonly|none].
2323
2324	  On a system with recent enough glibc (2.14 or newer) and no
2325	  static binaries, you can say None without a performance penalty
2326	  to improve security.
2327
2328	  If unsure, select "Emulate execution only".
2329
2330	config LEGACY_VSYSCALL_EMULATE
2331		bool "Full emulation"
2332		help
2333		  The kernel traps and emulates calls into the fixed vsyscall
2334		  address mapping. This makes the mapping non-executable, but
2335		  it still contains readable known contents, which could be
2336		  used in certain rare security vulnerability exploits. This
2337		  configuration is recommended when using legacy userspace
2338		  that still uses vsyscalls along with legacy binary
2339		  instrumentation tools that require code to be readable.
2340
2341		  An example of this type of legacy userspace is running
2342		  Pin on an old binary that still uses vsyscalls.
2343
2344	config LEGACY_VSYSCALL_XONLY
2345		bool "Emulate execution only"
2346		help
2347		  The kernel traps and emulates calls into the fixed vsyscall
2348		  address mapping and does not allow reads.  This
2349		  configuration is recommended when userspace might use the
2350		  legacy vsyscall area but support for legacy binary
2351		  instrumentation of legacy code is not needed.  It mitigates
2352		  certain uses of the vsyscall area as an ASLR-bypassing
2353		  buffer.
2354
2355	config LEGACY_VSYSCALL_NONE
2356		bool "None"
2357		help
2358		  There will be no vsyscall mapping at all. This will
2359		  eliminate any risk of ASLR bypass due to the vsyscall
2360		  fixed address mapping. Attempts to use the vsyscalls
2361		  will be reported to dmesg, so that either old or
2362		  malicious userspace programs can be identified.
2363
2364endchoice
2365
2366config CMDLINE_BOOL
2367	bool "Built-in kernel command line"
2368	---help---
2369	  Allow for specifying boot arguments to the kernel at
2370	  build time.  On some systems (e.g. embedded ones), it is
2371	  necessary or convenient to provide some or all of the
2372	  kernel boot arguments with the kernel itself (that is,
2373	  to not rely on the boot loader to provide them.)
2374
2375	  To compile command line arguments into the kernel,
2376	  set this option to 'Y', then fill in the
2377	  boot arguments in CONFIG_CMDLINE.
2378
2379	  Systems with fully functional boot loaders (i.e. non-embedded)
2380	  should leave this option set to 'N'.
2381
2382config CMDLINE
2383	string "Built-in kernel command string"
2384	depends on CMDLINE_BOOL
2385	default ""
2386	---help---
2387	  Enter arguments here that should be compiled into the kernel
2388	  image and used at boot time.  If the boot loader provides a
2389	  command line at boot time, it is appended to this string to
2390	  form the full kernel command line, when the system boots.
2391
2392	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2393	  change this behavior.
2394
2395	  In most cases, the command line (whether built-in or provided
2396	  by the boot loader) should specify the device for the root
2397	  file system.
2398
2399config CMDLINE_OVERRIDE
2400	bool "Built-in command line overrides boot loader arguments"
2401	depends on CMDLINE_BOOL
2402	---help---
2403	  Set this option to 'Y' to have the kernel ignore the boot loader
2404	  command line, and use ONLY the built-in command line.
2405
2406	  This is used to work around broken boot loaders.  This should
2407	  be set to 'N' under normal conditions.
2408
2409config MODIFY_LDT_SYSCALL
2410	bool "Enable the LDT (local descriptor table)" if EXPERT
2411	default y
2412	---help---
2413	  Linux can allow user programs to install a per-process x86
2414	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2415	  call.  This is required to run 16-bit or segmented code such as
2416	  DOSEMU or some Wine programs.  It is also used by some very old
2417	  threading libraries.
2418
2419	  Enabling this feature adds a small amount of overhead to
2420	  context switches and increases the low-level kernel attack
2421	  surface.  Disabling it removes the modify_ldt(2) system call.
2422
2423	  Saying 'N' here may make sense for embedded or server kernels.
2424
2425source "kernel/livepatch/Kconfig"
2426
2427endmenu
2428
2429config ARCH_HAS_ADD_PAGES
2430	def_bool y
2431	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2432
2433config ARCH_ENABLE_MEMORY_HOTPLUG
2434	def_bool y
2435	depends on X86_64 || (X86_32 && HIGHMEM)
2436
2437config ARCH_ENABLE_MEMORY_HOTREMOVE
2438	def_bool y
2439	depends on MEMORY_HOTPLUG
2440
2441config USE_PERCPU_NUMA_NODE_ID
2442	def_bool y
2443	depends on NUMA
2444
2445config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2446	def_bool y
2447	depends on X86_64 || X86_PAE
2448
2449config ARCH_ENABLE_HUGEPAGE_MIGRATION
2450	def_bool y
2451	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2452
2453config ARCH_ENABLE_THP_MIGRATION
2454	def_bool y
2455	depends on X86_64 && TRANSPARENT_HUGEPAGE
2456
2457menu "Power management and ACPI options"
2458
2459config ARCH_HIBERNATION_HEADER
2460	def_bool y
2461	depends on HIBERNATION
2462
2463source "kernel/power/Kconfig"
2464
2465source "drivers/acpi/Kconfig"
2466
2467source "drivers/sfi/Kconfig"
2468
2469config X86_APM_BOOT
2470	def_bool y
2471	depends on APM
2472
2473menuconfig APM
2474	tristate "APM (Advanced Power Management) BIOS support"
2475	depends on X86_32 && PM_SLEEP
2476	---help---
2477	  APM is a BIOS specification for saving power using several different
2478	  techniques. This is mostly useful for battery powered laptops with
2479	  APM compliant BIOSes. If you say Y here, the system time will be
2480	  reset after a RESUME operation, the /proc/apm device will provide
2481	  battery status information, and user-space programs will receive
2482	  notification of APM "events" (e.g. battery status change).
2483
2484	  If you select "Y" here, you can disable actual use of the APM
2485	  BIOS by passing the "apm=off" option to the kernel at boot time.
2486
2487	  Note that the APM support is almost completely disabled for
2488	  machines with more than one CPU.
2489
2490	  In order to use APM, you will need supporting software. For location
2491	  and more information, read <file:Documentation/power/apm-acpi.rst>
2492	  and the Battery Powered Linux mini-HOWTO, available from
2493	  <http://www.tldp.org/docs.html#howto>.
2494
2495	  This driver does not spin down disk drives (see the hdparm(8)
2496	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2497	  VESA-compliant "green" monitors.
2498
2499	  This driver does not support the TI 4000M TravelMate and the ACER
2500	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2501	  desktop machines also don't have compliant BIOSes, and this driver
2502	  may cause those machines to panic during the boot phase.
2503
2504	  Generally, if you don't have a battery in your machine, there isn't
2505	  much point in using this driver and you should say N. If you get
2506	  random kernel OOPSes or reboots that don't seem to be related to
2507	  anything, try disabling/enabling this option (or disabling/enabling
2508	  APM in your BIOS).
2509
2510	  Some other things you should try when experiencing seemingly random,
2511	  "weird" problems:
2512
2513	  1) make sure that you have enough swap space and that it is
2514	  enabled.
2515	  2) pass the "no-hlt" option to the kernel
2516	  3) switch on floating point emulation in the kernel and pass
2517	  the "no387" option to the kernel
2518	  4) pass the "floppy=nodma" option to the kernel
2519	  5) pass the "mem=4M" option to the kernel (thereby disabling
2520	  all but the first 4 MB of RAM)
2521	  6) make sure that the CPU is not over clocked.
2522	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2523	  8) disable the cache from your BIOS settings
2524	  9) install a fan for the video card or exchange video RAM
2525	  10) install a better fan for the CPU
2526	  11) exchange RAM chips
2527	  12) exchange the motherboard.
2528
2529	  To compile this driver as a module, choose M here: the
2530	  module will be called apm.
2531
2532if APM
2533
2534config APM_IGNORE_USER_SUSPEND
2535	bool "Ignore USER SUSPEND"
2536	---help---
2537	  This option will ignore USER SUSPEND requests. On machines with a
2538	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2539	  series notebooks, it is necessary to say Y because of a BIOS bug.
2540
2541config APM_DO_ENABLE
2542	bool "Enable PM at boot time"
2543	---help---
2544	  Enable APM features at boot time. From page 36 of the APM BIOS
2545	  specification: "When disabled, the APM BIOS does not automatically
2546	  power manage devices, enter the Standby State, enter the Suspend
2547	  State, or take power saving steps in response to CPU Idle calls."
2548	  This driver will make CPU Idle calls when Linux is idle (unless this
2549	  feature is turned off -- see "Do CPU IDLE calls", below). This
2550	  should always save battery power, but more complicated APM features
2551	  will be dependent on your BIOS implementation. You may need to turn
2552	  this option off if your computer hangs at boot time when using APM
2553	  support, or if it beeps continuously instead of suspending. Turn
2554	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2555	  T400CDT. This is off by default since most machines do fine without
2556	  this feature.
2557
2558config APM_CPU_IDLE
2559	depends on CPU_IDLE
2560	bool "Make CPU Idle calls when idle"
2561	---help---
2562	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2563	  On some machines, this can activate improved power savings, such as
2564	  a slowed CPU clock rate, when the machine is idle. These idle calls
2565	  are made after the idle loop has run for some length of time (e.g.,
2566	  333 mS). On some machines, this will cause a hang at boot time or
2567	  whenever the CPU becomes idle. (On machines with more than one CPU,
2568	  this option does nothing.)
2569
2570config APM_DISPLAY_BLANK
2571	bool "Enable console blanking using APM"
2572	---help---
2573	  Enable console blanking using the APM. Some laptops can use this to
2574	  turn off the LCD backlight when the screen blanker of the Linux
2575	  virtual console blanks the screen. Note that this is only used by
2576	  the virtual console screen blanker, and won't turn off the backlight
2577	  when using the X Window system. This also doesn't have anything to
2578	  do with your VESA-compliant power-saving monitor. Further, this
2579	  option doesn't work for all laptops -- it might not turn off your
2580	  backlight at all, or it might print a lot of errors to the console,
2581	  especially if you are using gpm.
2582
2583config APM_ALLOW_INTS
2584	bool "Allow interrupts during APM BIOS calls"
2585	---help---
2586	  Normally we disable external interrupts while we are making calls to
2587	  the APM BIOS as a measure to lessen the effects of a badly behaving
2588	  BIOS implementation.  The BIOS should reenable interrupts if it
2589	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2590	  many of the newer IBM Thinkpads.  If you experience hangs when you
2591	  suspend, try setting this to Y.  Otherwise, say N.
2592
2593endif # APM
2594
2595source "drivers/cpufreq/Kconfig"
2596
2597source "drivers/cpuidle/Kconfig"
2598
2599source "drivers/idle/Kconfig"
2600
2601endmenu
2602
2603
2604menu "Bus options (PCI etc.)"
2605
2606choice
2607	prompt "PCI access mode"
2608	depends on X86_32 && PCI
2609	default PCI_GOANY
2610	---help---
2611	  On PCI systems, the BIOS can be used to detect the PCI devices and
2612	  determine their configuration. However, some old PCI motherboards
2613	  have BIOS bugs and may crash if this is done. Also, some embedded
2614	  PCI-based systems don't have any BIOS at all. Linux can also try to
2615	  detect the PCI hardware directly without using the BIOS.
2616
2617	  With this option, you can specify how Linux should detect the
2618	  PCI devices. If you choose "BIOS", the BIOS will be used,
2619	  if you choose "Direct", the BIOS won't be used, and if you
2620	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2621	  If you choose "Any", the kernel will try MMCONFIG, then the
2622	  direct access method and falls back to the BIOS if that doesn't
2623	  work. If unsure, go with the default, which is "Any".
2624
2625config PCI_GOBIOS
2626	bool "BIOS"
2627
2628config PCI_GOMMCONFIG
2629	bool "MMConfig"
2630
2631config PCI_GODIRECT
2632	bool "Direct"
2633
2634config PCI_GOOLPC
2635	bool "OLPC XO-1"
2636	depends on OLPC
2637
2638config PCI_GOANY
2639	bool "Any"
2640
2641endchoice
2642
2643config PCI_BIOS
2644	def_bool y
2645	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2646
2647# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2648config PCI_DIRECT
2649	def_bool y
2650	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2651
2652config PCI_MMCONFIG
2653	bool "Support mmconfig PCI config space access" if X86_64
2654	default y
2655	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2656	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2657
2658config PCI_OLPC
2659	def_bool y
2660	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2661
2662config PCI_XEN
2663	def_bool y
2664	depends on PCI && XEN
2665	select SWIOTLB_XEN
2666
2667config MMCONF_FAM10H
2668	def_bool y
2669	depends on X86_64 && PCI_MMCONFIG && ACPI
2670
2671config PCI_CNB20LE_QUIRK
2672	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2673	depends on PCI
2674	help
2675	  Read the PCI windows out of the CNB20LE host bridge. This allows
2676	  PCI hotplug to work on systems with the CNB20LE chipset which do
2677	  not have ACPI.
2678
2679	  There's no public spec for this chipset, and this functionality
2680	  is known to be incomplete.
2681
2682	  You should say N unless you know you need this.
2683
2684config ISA_BUS
2685	bool "ISA bus support on modern systems" if EXPERT
2686	help
2687	  Expose ISA bus device drivers and options available for selection and
2688	  configuration. Enable this option if your target machine has an ISA
2689	  bus. ISA is an older system, displaced by PCI and newer bus
2690	  architectures -- if your target machine is modern, it probably does
2691	  not have an ISA bus.
2692
2693	  If unsure, say N.
2694
2695# x86_64 have no ISA slots, but can have ISA-style DMA.
2696config ISA_DMA_API
2697	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2698	default y
2699	help
2700	  Enables ISA-style DMA support for devices requiring such controllers.
2701	  If unsure, say Y.
2702
2703if X86_32
2704
2705config ISA
2706	bool "ISA support"
2707	---help---
2708	  Find out whether you have ISA slots on your motherboard.  ISA is the
2709	  name of a bus system, i.e. the way the CPU talks to the other stuff
2710	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2711	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2712	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2713
2714config SCx200
2715	tristate "NatSemi SCx200 support"
2716	---help---
2717	  This provides basic support for National Semiconductor's
2718	  (now AMD's) Geode processors.  The driver probes for the
2719	  PCI-IDs of several on-chip devices, so its a good dependency
2720	  for other scx200_* drivers.
2721
2722	  If compiled as a module, the driver is named scx200.
2723
2724config SCx200HR_TIMER
2725	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2726	depends on SCx200
2727	default y
2728	---help---
2729	  This driver provides a clocksource built upon the on-chip
2730	  27MHz high-resolution timer.  Its also a workaround for
2731	  NSC Geode SC-1100's buggy TSC, which loses time when the
2732	  processor goes idle (as is done by the scheduler).  The
2733	  other workaround is idle=poll boot option.
2734
2735config OLPC
2736	bool "One Laptop Per Child support"
2737	depends on !X86_PAE
2738	select GPIOLIB
2739	select OF
2740	select OF_PROMTREE
2741	select IRQ_DOMAIN
2742	select OLPC_EC
2743	---help---
2744	  Add support for detecting the unique features of the OLPC
2745	  XO hardware.
2746
2747config OLPC_XO1_PM
2748	bool "OLPC XO-1 Power Management"
2749	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2750	---help---
2751	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2752
2753config OLPC_XO1_RTC
2754	bool "OLPC XO-1 Real Time Clock"
2755	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2756	---help---
2757	  Add support for the XO-1 real time clock, which can be used as a
2758	  programmable wakeup source.
2759
2760config OLPC_XO1_SCI
2761	bool "OLPC XO-1 SCI extras"
2762	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2763	depends on INPUT=y
2764	select POWER_SUPPLY
2765	---help---
2766	  Add support for SCI-based features of the OLPC XO-1 laptop:
2767	   - EC-driven system wakeups
2768	   - Power button
2769	   - Ebook switch
2770	   - Lid switch
2771	   - AC adapter status updates
2772	   - Battery status updates
2773
2774config OLPC_XO15_SCI
2775	bool "OLPC XO-1.5 SCI extras"
2776	depends on OLPC && ACPI
2777	select POWER_SUPPLY
2778	---help---
2779	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2780	   - EC-driven system wakeups
2781	   - AC adapter status updates
2782	   - Battery status updates
2783
2784config ALIX
2785	bool "PCEngines ALIX System Support (LED setup)"
2786	select GPIOLIB
2787	---help---
2788	  This option enables system support for the PCEngines ALIX.
2789	  At present this just sets up LEDs for GPIO control on
2790	  ALIX2/3/6 boards.  However, other system specific setup should
2791	  get added here.
2792
2793	  Note: You must still enable the drivers for GPIO and LED support
2794	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2795
2796	  Note: You have to set alix.force=1 for boards with Award BIOS.
2797
2798config NET5501
2799	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2800	select GPIOLIB
2801	---help---
2802	  This option enables system support for the Soekris Engineering net5501.
2803
2804config GEOS
2805	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2806	select GPIOLIB
2807	depends on DMI
2808	---help---
2809	  This option enables system support for the Traverse Technologies GEOS.
2810
2811config TS5500
2812	bool "Technologic Systems TS-5500 platform support"
2813	depends on MELAN
2814	select CHECK_SIGNATURE
2815	select NEW_LEDS
2816	select LEDS_CLASS
2817	---help---
2818	  This option enables system support for the Technologic Systems TS-5500.
2819
2820endif # X86_32
2821
2822config AMD_NB
2823	def_bool y
2824	depends on CPU_SUP_AMD && PCI
2825
2826config X86_SYSFB
2827	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2828	help
2829	  Firmwares often provide initial graphics framebuffers so the BIOS,
2830	  bootloader or kernel can show basic video-output during boot for
2831	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2832	  Extensions and EFI-framebuffers for this, which are mostly limited
2833	  to x86.
2834	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2835	  framebuffers so the new generic system-framebuffer drivers can be
2836	  used on x86. If the framebuffer is not compatible with the generic
2837	  modes, it is advertised as fallback platform framebuffer so legacy
2838	  drivers like efifb, vesafb and uvesafb can pick it up.
2839	  If this option is not selected, all system framebuffers are always
2840	  marked as fallback platform framebuffers as usual.
2841
2842	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2843	  not be able to pick up generic system framebuffers if this option
2844	  is selected. You are highly encouraged to enable simplefb as
2845	  replacement if you select this option. simplefb can correctly deal
2846	  with generic system framebuffers. But you should still keep vesafb
2847	  and others enabled as fallback if a system framebuffer is
2848	  incompatible with simplefb.
2849
2850	  If unsure, say Y.
2851
2852endmenu
2853
2854
2855menu "Binary Emulations"
2856
2857config IA32_EMULATION
2858	bool "IA32 Emulation"
2859	depends on X86_64
2860	select ARCH_WANT_OLD_COMPAT_IPC
2861	select BINFMT_ELF
2862	select COMPAT_BINFMT_ELF
2863	select COMPAT_OLD_SIGACTION
2864	---help---
2865	  Include code to run legacy 32-bit programs under a
2866	  64-bit kernel. You should likely turn this on, unless you're
2867	  100% sure that you don't have any 32-bit programs left.
2868
2869config IA32_AOUT
2870	tristate "IA32 a.out support"
2871	depends on IA32_EMULATION
2872	depends on BROKEN
2873	---help---
2874	  Support old a.out binaries in the 32bit emulation.
2875
2876config X86_X32
2877	bool "x32 ABI for 64-bit mode"
2878	depends on X86_64
2879	---help---
2880	  Include code to run binaries for the x32 native 32-bit ABI
2881	  for 64-bit processors.  An x32 process gets access to the
2882	  full 64-bit register file and wide data path while leaving
2883	  pointers at 32 bits for smaller memory footprint.
2884
2885	  You will need a recent binutils (2.22 or later) with
2886	  elf32_x86_64 support enabled to compile a kernel with this
2887	  option set.
2888
2889config COMPAT_32
2890	def_bool y
2891	depends on IA32_EMULATION || X86_32
2892	select HAVE_UID16
2893	select OLD_SIGSUSPEND3
2894
2895config COMPAT
2896	def_bool y
2897	depends on IA32_EMULATION || X86_X32
2898
2899if COMPAT
2900config COMPAT_FOR_U64_ALIGNMENT
2901	def_bool y
2902
2903config SYSVIPC_COMPAT
2904	def_bool y
2905	depends on SYSVIPC
2906endif
2907
2908endmenu
2909
2910
2911config HAVE_ATOMIC_IOMAP
2912	def_bool y
2913	depends on X86_32
2914
2915config X86_DEV_DMA_OPS
2916	bool
2917
2918source "drivers/firmware/Kconfig"
2919
2920source "arch/x86/kvm/Kconfig"
2921