xref: /openbmc/linux/arch/x86/Kconfig (revision 113094f7)
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_SPECIAL
74	select ARCH_HAS_REFCOUNT
75	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
76	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
77	select ARCH_HAS_SET_MEMORY
78	select ARCH_HAS_SET_DIRECT_MAP
79	select ARCH_HAS_STRICT_KERNEL_RWX
80	select ARCH_HAS_STRICT_MODULE_RWX
81	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
82	select ARCH_HAS_UBSAN_SANITIZE_ALL
83	select ARCH_HAS_ZONE_DEVICE		if X86_64
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_WANTS_THP_SWAP		if X86_64
98	select BUILDTIME_EXTABLE_SORT
99	select CLKEVT_I8253
100	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
101	select CLOCKSOURCE_WATCHDOG
102	select DCACHE_WORD_ACCESS
103	select EDAC_ATOMIC_SCRUB
104	select EDAC_SUPPORT
105	select GENERIC_CLOCKEVENTS
106	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
107	select GENERIC_CLOCKEVENTS_MIN_ADJUST
108	select GENERIC_CMOS_UPDATE
109	select GENERIC_CPU_AUTOPROBE
110	select GENERIC_CPU_VULNERABILITIES
111	select GENERIC_EARLY_IOREMAP
112	select GENERIC_FIND_FIRST_BIT
113	select GENERIC_IOMAP
114	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
115	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
116	select GENERIC_IRQ_MIGRATION		if SMP
117	select GENERIC_IRQ_PROBE
118	select GENERIC_IRQ_RESERVATION_MODE
119	select GENERIC_IRQ_SHOW
120	select GENERIC_PENDING_IRQ		if SMP
121	select GENERIC_SMP_IDLE_THREAD
122	select GENERIC_STRNCPY_FROM_USER
123	select GENERIC_STRNLEN_USER
124	select GENERIC_TIME_VSYSCALL
125	select GENERIC_GETTIMEOFDAY
126	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
127	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
128	select HAVE_ACPI_APEI			if ACPI
129	select HAVE_ACPI_APEI_NMI		if ACPI
130	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
131	select HAVE_ARCH_AUDITSYSCALL
132	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
133	select HAVE_ARCH_JUMP_LABEL
134	select HAVE_ARCH_JUMP_LABEL_RELATIVE
135	select HAVE_ARCH_KASAN			if X86_64
136	select HAVE_ARCH_KGDB
137	select HAVE_ARCH_MMAP_RND_BITS		if MMU
138	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
139	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
140	select HAVE_ARCH_PREL32_RELOCATIONS
141	select HAVE_ARCH_SECCOMP_FILTER
142	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
143	select HAVE_ARCH_STACKLEAK
144	select HAVE_ARCH_TRACEHOOK
145	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
146	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
147	select HAVE_ARCH_VMAP_STACK		if X86_64
148	select HAVE_ARCH_WITHIN_STACK_FRAMES
149	select HAVE_CMPXCHG_DOUBLE
150	select HAVE_CMPXCHG_LOCAL
151	select HAVE_CONTEXT_TRACKING		if X86_64
152	select HAVE_COPY_THREAD_TLS
153	select HAVE_C_RECORDMCOUNT
154	select HAVE_DEBUG_KMEMLEAK
155	select HAVE_DMA_CONTIGUOUS
156	select HAVE_DYNAMIC_FTRACE
157	select HAVE_DYNAMIC_FTRACE_WITH_REGS
158	select HAVE_EBPF_JIT
159	select HAVE_EFFICIENT_UNALIGNED_ACCESS
160	select HAVE_EISA
161	select HAVE_EXIT_THREAD
162	select HAVE_FAST_GUP
163	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
164	select HAVE_FTRACE_MCOUNT_RECORD
165	select HAVE_FUNCTION_GRAPH_TRACER
166	select HAVE_FUNCTION_TRACER
167	select HAVE_GCC_PLUGINS
168	select HAVE_HW_BREAKPOINT
169	select HAVE_IDE
170	select HAVE_IOREMAP_PROT
171	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
172	select HAVE_IRQ_TIME_ACCOUNTING
173	select HAVE_KERNEL_BZIP2
174	select HAVE_KERNEL_GZIP
175	select HAVE_KERNEL_LZ4
176	select HAVE_KERNEL_LZMA
177	select HAVE_KERNEL_LZO
178	select HAVE_KERNEL_XZ
179	select HAVE_KPROBES
180	select HAVE_KPROBES_ON_FTRACE
181	select HAVE_FUNCTION_ERROR_INJECTION
182	select HAVE_KRETPROBES
183	select HAVE_KVM
184	select HAVE_LIVEPATCH			if X86_64
185	select HAVE_MEMBLOCK_NODE_MAP
186	select HAVE_MIXED_BREAKPOINTS_REGS
187	select HAVE_MOD_ARCH_SPECIFIC
188	select HAVE_MOVE_PMD
189	select HAVE_NMI
190	select HAVE_OPROFILE
191	select HAVE_OPTPROBES
192	select HAVE_PCSPKR_PLATFORM
193	select HAVE_PERF_EVENTS
194	select HAVE_PERF_EVENTS_NMI
195	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
196	select HAVE_PCI
197	select HAVE_PERF_REGS
198	select HAVE_PERF_USER_STACK_DUMP
199	select HAVE_RCU_TABLE_FREE		if PARAVIRT
200	select HAVE_REGS_AND_STACK_ACCESS_API
201	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
202	select HAVE_FUNCTION_ARG_ACCESS_API
203	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
204	select HAVE_STACK_VALIDATION		if X86_64
205	select HAVE_RSEQ
206	select HAVE_SYSCALL_TRACEPOINTS
207	select HAVE_UNSTABLE_SCHED_CLOCK
208	select HAVE_USER_RETURN_NOTIFIER
209	select HAVE_GENERIC_VDSO
210	select HOTPLUG_SMT			if SMP
211	select IRQ_FORCED_THREADING
212	select NEED_SG_DMA_LENGTH
213	select PCI_DOMAINS			if PCI
214	select PCI_LOCKLESS_CONFIG		if PCI
215	select PERF_EVENTS
216	select RTC_LIB
217	select RTC_MC146818_LIB
218	select SPARSE_IRQ
219	select SRCU
220	select SYSCTL_EXCEPTION_TRACE
221	select THREAD_INFO_IN_TASK
222	select USER_STACKTRACE_SUPPORT
223	select VIRT_TO_BUS
224	select X86_FEATURE_NAMES		if PROC_FS
225	select PROC_PID_ARCH_STATUS		if PROC_FS
226
227config INSTRUCTION_DECODER
228	def_bool y
229	depends on KPROBES || PERF_EVENTS || UPROBES
230
231config OUTPUT_FORMAT
232	string
233	default "elf32-i386" if X86_32
234	default "elf64-x86-64" if X86_64
235
236config ARCH_DEFCONFIG
237	string
238	default "arch/x86/configs/i386_defconfig" if X86_32
239	default "arch/x86/configs/x86_64_defconfig" if X86_64
240
241config LOCKDEP_SUPPORT
242	def_bool y
243
244config STACKTRACE_SUPPORT
245	def_bool y
246
247config MMU
248	def_bool y
249
250config ARCH_MMAP_RND_BITS_MIN
251	default 28 if 64BIT
252	default 8
253
254config ARCH_MMAP_RND_BITS_MAX
255	default 32 if 64BIT
256	default 16
257
258config ARCH_MMAP_RND_COMPAT_BITS_MIN
259	default 8
260
261config ARCH_MMAP_RND_COMPAT_BITS_MAX
262	default 16
263
264config SBUS
265	bool
266
267config GENERIC_ISA_DMA
268	def_bool y
269	depends on ISA_DMA_API
270
271config GENERIC_BUG
272	def_bool y
273	depends on BUG
274	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
275
276config GENERIC_BUG_RELATIVE_POINTERS
277	bool
278
279config ARCH_MAY_HAVE_PC_FDC
280	def_bool y
281	depends on ISA_DMA_API
282
283config GENERIC_CALIBRATE_DELAY
284	def_bool y
285
286config ARCH_HAS_CPU_RELAX
287	def_bool y
288
289config ARCH_HAS_CACHE_LINE_SIZE
290	def_bool y
291
292config ARCH_HAS_FILTER_PGPROT
293	def_bool y
294
295config HAVE_SETUP_PER_CPU_AREA
296	def_bool y
297
298config NEED_PER_CPU_EMBED_FIRST_CHUNK
299	def_bool y
300
301config NEED_PER_CPU_PAGE_FIRST_CHUNK
302	def_bool y
303
304config ARCH_HIBERNATION_POSSIBLE
305	def_bool y
306
307config ARCH_SUSPEND_POSSIBLE
308	def_bool y
309
310config ARCH_WANT_HUGE_PMD_SHARE
311	def_bool y
312
313config ARCH_WANT_GENERAL_HUGETLB
314	def_bool y
315
316config ZONE_DMA32
317	def_bool y if X86_64
318
319config AUDIT_ARCH
320	def_bool y if X86_64
321
322config ARCH_SUPPORTS_DEBUG_PAGEALLOC
323	def_bool y
324
325config KASAN_SHADOW_OFFSET
326	hex
327	depends on KASAN
328	default 0xdffffc0000000000
329
330config HAVE_INTEL_TXT
331	def_bool y
332	depends on INTEL_IOMMU && ACPI
333
334config X86_32_SMP
335	def_bool y
336	depends on X86_32 && SMP
337
338config X86_64_SMP
339	def_bool y
340	depends on X86_64 && SMP
341
342config X86_32_LAZY_GS
343	def_bool y
344	depends on X86_32 && !STACKPROTECTOR
345
346config ARCH_SUPPORTS_UPROBES
347	def_bool y
348
349config FIX_EARLYCON_MEM
350	def_bool y
351
352config DYNAMIC_PHYSICAL_MASK
353	bool
354
355config PGTABLE_LEVELS
356	int
357	default 5 if X86_5LEVEL
358	default 4 if X86_64
359	default 3 if X86_PAE
360	default 2
361
362config CC_HAS_SANE_STACKPROTECTOR
363	bool
364	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
365	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
366	help
367	   We have to make sure stack protector is unconditionally disabled if
368	   the compiler produces broken code.
369
370menu "Processor type and features"
371
372config ZONE_DMA
373	bool "DMA memory allocation support" if EXPERT
374	default y
375	help
376	  DMA memory allocation support allows devices with less than 32-bit
377	  addressing to allocate within the first 16MB of address space.
378	  Disable if no such devices will be used.
379
380	  If unsure, say Y.
381
382config SMP
383	bool "Symmetric multi-processing support"
384	---help---
385	  This enables support for systems with more than one CPU. If you have
386	  a system with only one CPU, say N. If you have a system with more
387	  than one CPU, say Y.
388
389	  If you say N here, the kernel will run on uni- and multiprocessor
390	  machines, but will use only one CPU of a multiprocessor machine. If
391	  you say Y here, the kernel will run on many, but not all,
392	  uniprocessor machines. On a uniprocessor machine, the kernel
393	  will run faster if you say N here.
394
395	  Note that if you say Y here and choose architecture "586" or
396	  "Pentium" under "Processor family", the kernel will not work on 486
397	  architectures. Similarly, multiprocessor kernels for the "PPro"
398	  architecture may not work on all Pentium based boards.
399
400	  People using multiprocessor machines who say Y here should also say
401	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
402	  Management" code will be disabled if you say Y here.
403
404	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
405	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
406	  <http://www.tldp.org/docs.html#howto>.
407
408	  If you don't know what to do here, say N.
409
410config X86_FEATURE_NAMES
411	bool "Processor feature human-readable names" if EMBEDDED
412	default y
413	---help---
414	  This option compiles in a table of x86 feature bits and corresponding
415	  names.  This is required to support /proc/cpuinfo and a few kernel
416	  messages.  You can disable this to save space, at the expense of
417	  making those few kernel messages show numeric feature bits instead.
418
419	  If in doubt, say Y.
420
421config X86_X2APIC
422	bool "Support x2apic"
423	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
424	---help---
425	  This enables x2apic support on CPUs that have this feature.
426
427	  This allows 32-bit apic IDs (so it can support very large systems),
428	  and accesses the local apic via MSRs not via mmio.
429
430	  If you don't know what to do here, say N.
431
432config X86_MPPARSE
433	bool "Enable MPS table" if ACPI || SFI
434	default y
435	depends on X86_LOCAL_APIC
436	---help---
437	  For old smp systems that do not have proper acpi support. Newer systems
438	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
439
440config GOLDFISH
441       def_bool y
442       depends on X86_GOLDFISH
443
444config RETPOLINE
445	bool "Avoid speculative indirect branches in kernel"
446	default y
447	select STACK_VALIDATION if HAVE_STACK_VALIDATION
448	help
449	  Compile kernel with the retpoline compiler options to guard against
450	  kernel-to-user data leaks by avoiding speculative indirect
451	  branches. Requires a compiler with -mindirect-branch=thunk-extern
452	  support for full protection. The kernel may run slower.
453
454config X86_CPU_RESCTRL
455	bool "x86 CPU resource control support"
456	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
457	select KERNFS
458	help
459	  Enable x86 CPU resource control support.
460
461	  Provide support for the allocation and monitoring of system resources
462	  usage by the CPU.
463
464	  Intel calls this Intel Resource Director Technology
465	  (Intel(R) RDT). More information about RDT can be found in the
466	  Intel x86 Architecture Software Developer Manual.
467
468	  AMD calls this AMD Platform Quality of Service (AMD QoS).
469	  More information about AMD QoS can be found in the AMD64 Technology
470	  Platform Quality of Service Extensions manual.
471
472	  Say N if unsure.
473
474if X86_32
475config X86_BIGSMP
476	bool "Support for big SMP systems with more than 8 CPUs"
477	depends on SMP
478	---help---
479	  This option is needed for the systems that have more than 8 CPUs
480
481config X86_EXTENDED_PLATFORM
482	bool "Support for extended (non-PC) x86 platforms"
483	default y
484	---help---
485	  If you disable this option then the kernel will only support
486	  standard PC platforms. (which covers the vast majority of
487	  systems out there.)
488
489	  If you enable this option then you'll be able to select support
490	  for the following (non-PC) 32 bit x86 platforms:
491		Goldfish (Android emulator)
492		AMD Elan
493		RDC R-321x SoC
494		SGI 320/540 (Visual Workstation)
495		STA2X11-based (e.g. Northville)
496		Moorestown MID devices
497
498	  If you have one of these systems, or if you want to build a
499	  generic distribution kernel, say Y here - otherwise say N.
500endif
501
502if X86_64
503config X86_EXTENDED_PLATFORM
504	bool "Support for extended (non-PC) x86 platforms"
505	default y
506	---help---
507	  If you disable this option then the kernel will only support
508	  standard PC platforms. (which covers the vast majority of
509	  systems out there.)
510
511	  If you enable this option then you'll be able to select support
512	  for the following (non-PC) 64 bit x86 platforms:
513		Numascale NumaChip
514		ScaleMP vSMP
515		SGI Ultraviolet
516
517	  If you have one of these systems, or if you want to build a
518	  generic distribution kernel, say Y here - otherwise say N.
519endif
520# This is an alphabetically sorted list of 64 bit extended platforms
521# Please maintain the alphabetic order if and when there are additions
522config X86_NUMACHIP
523	bool "Numascale NumaChip"
524	depends on X86_64
525	depends on X86_EXTENDED_PLATFORM
526	depends on NUMA
527	depends on SMP
528	depends on X86_X2APIC
529	depends on PCI_MMCONFIG
530	---help---
531	  Adds support for Numascale NumaChip large-SMP systems. Needed to
532	  enable more than ~168 cores.
533	  If you don't have one of these, you should say N here.
534
535config X86_VSMP
536	bool "ScaleMP vSMP"
537	select HYPERVISOR_GUEST
538	select PARAVIRT
539	depends on X86_64 && PCI
540	depends on X86_EXTENDED_PLATFORM
541	depends on SMP
542	---help---
543	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
544	  supposed to run on these EM64T-based machines.  Only choose this option
545	  if you have one of these machines.
546
547config X86_UV
548	bool "SGI Ultraviolet"
549	depends on X86_64
550	depends on X86_EXTENDED_PLATFORM
551	depends on NUMA
552	depends on EFI
553	depends on X86_X2APIC
554	depends on PCI
555	---help---
556	  This option is needed in order to support SGI Ultraviolet systems.
557	  If you don't have one of these, you should say N here.
558
559# Following is an alphabetically sorted list of 32 bit extended platforms
560# Please maintain the alphabetic order if and when there are additions
561
562config X86_GOLDFISH
563       bool "Goldfish (Virtual Platform)"
564       depends on X86_EXTENDED_PLATFORM
565       ---help---
566	 Enable support for the Goldfish virtual platform used primarily
567	 for Android development. Unless you are building for the Android
568	 Goldfish emulator say N here.
569
570config X86_INTEL_CE
571	bool "CE4100 TV platform"
572	depends on PCI
573	depends on PCI_GODIRECT
574	depends on X86_IO_APIC
575	depends on X86_32
576	depends on X86_EXTENDED_PLATFORM
577	select X86_REBOOTFIXUPS
578	select OF
579	select OF_EARLY_FLATTREE
580	---help---
581	  Select for the Intel CE media processor (CE4100) SOC.
582	  This option compiles in support for the CE4100 SOC for settop
583	  boxes and media devices.
584
585config X86_INTEL_MID
586	bool "Intel MID platform support"
587	depends on X86_EXTENDED_PLATFORM
588	depends on X86_PLATFORM_DEVICES
589	depends on PCI
590	depends on X86_64 || (PCI_GOANY && X86_32)
591	depends on X86_IO_APIC
592	select SFI
593	select I2C
594	select DW_APB_TIMER
595	select APB_TIMER
596	select INTEL_SCU_IPC
597	select MFD_INTEL_MSIC
598	---help---
599	  Select to build a kernel capable of supporting Intel MID (Mobile
600	  Internet Device) platform systems which do not have the PCI legacy
601	  interfaces. If you are building for a PC class system say N here.
602
603	  Intel MID platforms are based on an Intel processor and chipset which
604	  consume less power than most of the x86 derivatives.
605
606config X86_INTEL_QUARK
607	bool "Intel Quark platform support"
608	depends on X86_32
609	depends on X86_EXTENDED_PLATFORM
610	depends on X86_PLATFORM_DEVICES
611	depends on X86_TSC
612	depends on PCI
613	depends on PCI_GOANY
614	depends on X86_IO_APIC
615	select IOSF_MBI
616	select INTEL_IMR
617	select COMMON_CLK
618	---help---
619	  Select to include support for Quark X1000 SoC.
620	  Say Y here if you have a Quark based system such as the Arduino
621	  compatible Intel Galileo.
622
623config X86_INTEL_LPSS
624	bool "Intel Low Power Subsystem Support"
625	depends on X86 && ACPI && PCI
626	select COMMON_CLK
627	select PINCTRL
628	select IOSF_MBI
629	---help---
630	  Select to build support for Intel Low Power Subsystem such as
631	  found on Intel Lynxpoint PCH. Selecting this option enables
632	  things like clock tree (common clock framework) and pincontrol
633	  which are needed by the LPSS peripheral drivers.
634
635config X86_AMD_PLATFORM_DEVICE
636	bool "AMD ACPI2Platform devices support"
637	depends on ACPI
638	select COMMON_CLK
639	select PINCTRL
640	---help---
641	  Select to interpret AMD specific ACPI device to platform device
642	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
643	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
644	  implemented under PINCTRL subsystem.
645
646config IOSF_MBI
647	tristate "Intel SoC IOSF Sideband support for SoC platforms"
648	depends on PCI
649	---help---
650	  This option enables sideband register access support for Intel SoC
651	  platforms. On these platforms the IOSF sideband is used in lieu of
652	  MSR's for some register accesses, mostly but not limited to thermal
653	  and power. Drivers may query the availability of this device to
654	  determine if they need the sideband in order to work on these
655	  platforms. The sideband is available on the following SoC products.
656	  This list is not meant to be exclusive.
657	   - BayTrail
658	   - Braswell
659	   - Quark
660
661	  You should say Y if you are running a kernel on one of these SoC's.
662
663config IOSF_MBI_DEBUG
664	bool "Enable IOSF sideband access through debugfs"
665	depends on IOSF_MBI && DEBUG_FS
666	---help---
667	  Select this option to expose the IOSF sideband access registers (MCR,
668	  MDR, MCRX) through debugfs to write and read register information from
669	  different units on the SoC. This is most useful for obtaining device
670	  state information for debug and analysis. As this is a general access
671	  mechanism, users of this option would have specific knowledge of the
672	  device they want to access.
673
674	  If you don't require the option or are in doubt, say N.
675
676config X86_RDC321X
677	bool "RDC R-321x SoC"
678	depends on X86_32
679	depends on X86_EXTENDED_PLATFORM
680	select M486
681	select X86_REBOOTFIXUPS
682	---help---
683	  This option is needed for RDC R-321x system-on-chip, also known
684	  as R-8610-(G).
685	  If you don't have one of these chips, you should say N here.
686
687config X86_32_NON_STANDARD
688	bool "Support non-standard 32-bit SMP architectures"
689	depends on X86_32 && SMP
690	depends on X86_EXTENDED_PLATFORM
691	---help---
692	  This option compiles in the bigsmp and STA2X11 default
693	  subarchitectures.  It is intended for a generic binary
694	  kernel. If you select them all, kernel will probe it one by
695	  one and will fallback to default.
696
697# Alphabetically sorted list of Non standard 32 bit platforms
698
699config X86_SUPPORTS_MEMORY_FAILURE
700	def_bool y
701	# MCE code calls memory_failure():
702	depends on X86_MCE
703	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
704	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
705	depends on X86_64 || !SPARSEMEM
706	select ARCH_SUPPORTS_MEMORY_FAILURE
707
708config STA2X11
709	bool "STA2X11 Companion Chip Support"
710	depends on X86_32_NON_STANDARD && PCI
711	select ARCH_HAS_PHYS_TO_DMA
712	select SWIOTLB
713	select MFD_STA2X11
714	select GPIOLIB
715	---help---
716	  This adds support for boards based on the STA2X11 IO-Hub,
717	  a.k.a. "ConneXt". The chip is used in place of the standard
718	  PC chipset, so all "standard" peripherals are missing. If this
719	  option is selected the kernel will still be able to boot on
720	  standard PC machines.
721
722config X86_32_IRIS
723	tristate "Eurobraille/Iris poweroff module"
724	depends on X86_32
725	---help---
726	  The Iris machines from EuroBraille do not have APM or ACPI support
727	  to shut themselves down properly.  A special I/O sequence is
728	  needed to do so, which is what this module does at
729	  kernel shutdown.
730
731	  This is only for Iris machines from EuroBraille.
732
733	  If unused, say N.
734
735config SCHED_OMIT_FRAME_POINTER
736	def_bool y
737	prompt "Single-depth WCHAN output"
738	depends on X86
739	---help---
740	  Calculate simpler /proc/<PID>/wchan values. If this option
741	  is disabled then wchan values will recurse back to the
742	  caller function. This provides more accurate wchan values,
743	  at the expense of slightly more scheduling overhead.
744
745	  If in doubt, say "Y".
746
747menuconfig HYPERVISOR_GUEST
748	bool "Linux guest support"
749	---help---
750	  Say Y here to enable options for running Linux under various hyper-
751	  visors. This option enables basic hypervisor detection and platform
752	  setup.
753
754	  If you say N, all options in this submenu will be skipped and
755	  disabled, and Linux guest support won't be built in.
756
757if HYPERVISOR_GUEST
758
759config PARAVIRT
760	bool "Enable paravirtualization code"
761	---help---
762	  This changes the kernel so it can modify itself when it is run
763	  under a hypervisor, potentially improving performance significantly
764	  over full virtualization.  However, when run without a hypervisor
765	  the kernel is theoretically slower and slightly larger.
766
767config PARAVIRT_XXL
768	bool
769
770config PARAVIRT_DEBUG
771	bool "paravirt-ops debugging"
772	depends on PARAVIRT && DEBUG_KERNEL
773	---help---
774	  Enable to debug paravirt_ops internals.  Specifically, BUG if
775	  a paravirt_op is missing when it is called.
776
777config PARAVIRT_SPINLOCKS
778	bool "Paravirtualization layer for spinlocks"
779	depends on PARAVIRT && SMP
780	---help---
781	  Paravirtualized spinlocks allow a pvops backend to replace the
782	  spinlock implementation with something virtualization-friendly
783	  (for example, block the virtual CPU rather than spinning).
784
785	  It has a minimal impact on native kernels and gives a nice performance
786	  benefit on paravirtualized KVM / Xen kernels.
787
788	  If you are unsure how to answer this question, answer Y.
789
790config X86_HV_CALLBACK_VECTOR
791	def_bool n
792
793source "arch/x86/xen/Kconfig"
794
795config KVM_GUEST
796	bool "KVM Guest support (including kvmclock)"
797	depends on PARAVIRT
798	select PARAVIRT_CLOCK
799	default y
800	---help---
801	  This option enables various optimizations for running under the KVM
802	  hypervisor. It includes a paravirtualized clock, so that instead
803	  of relying on a PIT (or probably other) emulation by the
804	  underlying device model, the host provides the guest with
805	  timing infrastructure such as time of day, and system time
806
807config PVH
808	bool "Support for running PVH guests"
809	---help---
810	  This option enables the PVH entry point for guest virtual machines
811	  as specified in the x86/HVM direct boot ABI.
812
813config KVM_DEBUG_FS
814	bool "Enable debug information for KVM Guests in debugfs"
815	depends on KVM_GUEST && DEBUG_FS
816	---help---
817	  This option enables collection of various statistics for KVM guest.
818	  Statistics are displayed in debugfs filesystem. Enabling this option
819	  may incur significant overhead.
820
821config PARAVIRT_TIME_ACCOUNTING
822	bool "Paravirtual steal time accounting"
823	depends on PARAVIRT
824	---help---
825	  Select this option to enable fine granularity task steal time
826	  accounting. Time spent executing other tasks in parallel with
827	  the current vCPU is discounted from the vCPU power. To account for
828	  that, there can be a small performance impact.
829
830	  If in doubt, say N here.
831
832config PARAVIRT_CLOCK
833	bool
834
835config JAILHOUSE_GUEST
836	bool "Jailhouse non-root cell support"
837	depends on X86_64 && PCI
838	select X86_PM_TIMER
839	---help---
840	  This option allows to run Linux as guest in a Jailhouse non-root
841	  cell. You can leave this option disabled if you only want to start
842	  Jailhouse and run Linux afterwards in the root cell.
843
844config ACRN_GUEST
845	bool "ACRN Guest support"
846	depends on X86_64
847	select X86_HV_CALLBACK_VECTOR
848	help
849	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
850	  a flexible, lightweight reference open-source hypervisor, built with
851	  real-time and safety-criticality in mind. It is built for embedded
852	  IOT with small footprint and real-time features. More details can be
853	  found in https://projectacrn.org/.
854
855endif #HYPERVISOR_GUEST
856
857source "arch/x86/Kconfig.cpu"
858
859config HPET_TIMER
860	def_bool X86_64
861	prompt "HPET Timer Support" if X86_32
862	---help---
863	  Use the IA-PC HPET (High Precision Event Timer) to manage
864	  time in preference to the PIT and RTC, if a HPET is
865	  present.
866	  HPET is the next generation timer replacing legacy 8254s.
867	  The HPET provides a stable time base on SMP
868	  systems, unlike the TSC, but it is more expensive to access,
869	  as it is off-chip.  The interface used is documented
870	  in the HPET spec, revision 1.
871
872	  You can safely choose Y here.  However, HPET will only be
873	  activated if the platform and the BIOS support this feature.
874	  Otherwise the 8254 will be used for timing services.
875
876	  Choose N to continue using the legacy 8254 timer.
877
878config HPET_EMULATE_RTC
879	def_bool y
880	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
881
882config APB_TIMER
883       def_bool y if X86_INTEL_MID
884       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
885       select DW_APB_TIMER
886       depends on X86_INTEL_MID && SFI
887       help
888         APB timer is the replacement for 8254, HPET on X86 MID platforms.
889         The APBT provides a stable time base on SMP
890         systems, unlike the TSC, but it is more expensive to access,
891         as it is off-chip. APB timers are always running regardless of CPU
892         C states, they are used as per CPU clockevent device when possible.
893
894# Mark as expert because too many people got it wrong.
895# The code disables itself when not needed.
896config DMI
897	default y
898	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
899	bool "Enable DMI scanning" if EXPERT
900	---help---
901	  Enabled scanning of DMI to identify machine quirks. Say Y
902	  here unless you have verified that your setup is not
903	  affected by entries in the DMI blacklist. Required by PNP
904	  BIOS code.
905
906config GART_IOMMU
907	bool "Old AMD GART IOMMU support"
908	select IOMMU_HELPER
909	select SWIOTLB
910	depends on X86_64 && PCI && AMD_NB
911	---help---
912	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
913	  GART based hardware IOMMUs.
914
915	  The GART supports full DMA access for devices with 32-bit access
916	  limitations, on systems with more than 3 GB. This is usually needed
917	  for USB, sound, many IDE/SATA chipsets and some other devices.
918
919	  Newer systems typically have a modern AMD IOMMU, supported via
920	  the CONFIG_AMD_IOMMU=y config option.
921
922	  In normal configurations this driver is only active when needed:
923	  there's more than 3 GB of memory and the system contains a
924	  32-bit limited device.
925
926	  If unsure, say Y.
927
928config CALGARY_IOMMU
929	bool "IBM Calgary IOMMU support"
930	select IOMMU_HELPER
931	select SWIOTLB
932	depends on X86_64 && PCI
933	---help---
934	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
935	  systems. Needed to run systems with more than 3GB of memory
936	  properly with 32-bit PCI devices that do not support DAC
937	  (Double Address Cycle). Calgary also supports bus level
938	  isolation, where all DMAs pass through the IOMMU.  This
939	  prevents them from going anywhere except their intended
940	  destination. This catches hard-to-find kernel bugs and
941	  mis-behaving drivers and devices that do not use the DMA-API
942	  properly to set up their DMA buffers.  The IOMMU can be
943	  turned off at boot time with the iommu=off parameter.
944	  Normally the kernel will make the right choice by itself.
945	  If unsure, say Y.
946
947config CALGARY_IOMMU_ENABLED_BY_DEFAULT
948	def_bool y
949	prompt "Should Calgary be enabled by default?"
950	depends on CALGARY_IOMMU
951	---help---
952	  Should Calgary be enabled by default? if you choose 'y', Calgary
953	  will be used (if it exists). If you choose 'n', Calgary will not be
954	  used even if it exists. If you choose 'n' and would like to use
955	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
956	  If unsure, say Y.
957
958config MAXSMP
959	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
960	depends on X86_64 && SMP && DEBUG_KERNEL
961	select CPUMASK_OFFSTACK
962	---help---
963	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
964	  If unsure, say N.
965
966#
967# The maximum number of CPUs supported:
968#
969# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
970# and which can be configured interactively in the
971# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
972#
973# The ranges are different on 32-bit and 64-bit kernels, depending on
974# hardware capabilities and scalability features of the kernel.
975#
976# ( If MAXSMP is enabled we just use the highest possible value and disable
977#   interactive configuration. )
978#
979
980config NR_CPUS_RANGE_BEGIN
981	int
982	default NR_CPUS_RANGE_END if MAXSMP
983	default    1 if !SMP
984	default    2
985
986config NR_CPUS_RANGE_END
987	int
988	depends on X86_32
989	default   64 if  SMP &&  X86_BIGSMP
990	default    8 if  SMP && !X86_BIGSMP
991	default    1 if !SMP
992
993config NR_CPUS_RANGE_END
994	int
995	depends on X86_64
996	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
997	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
998	default    1 if !SMP
999
1000config NR_CPUS_DEFAULT
1001	int
1002	depends on X86_32
1003	default   32 if  X86_BIGSMP
1004	default    8 if  SMP
1005	default    1 if !SMP
1006
1007config NR_CPUS_DEFAULT
1008	int
1009	depends on X86_64
1010	default 8192 if  MAXSMP
1011	default   64 if  SMP
1012	default    1 if !SMP
1013
1014config NR_CPUS
1015	int "Maximum number of CPUs" if SMP && !MAXSMP
1016	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1017	default NR_CPUS_DEFAULT
1018	---help---
1019	  This allows you to specify the maximum number of CPUs which this
1020	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1021	  supported value is 8192, otherwise the maximum value is 512.  The
1022	  minimum value which makes sense is 2.
1023
1024	  This is purely to save memory: each supported CPU adds about 8KB
1025	  to the kernel image.
1026
1027config SCHED_SMT
1028	def_bool y if SMP
1029
1030config SCHED_MC
1031	def_bool y
1032	prompt "Multi-core scheduler support"
1033	depends on SMP
1034	---help---
1035	  Multi-core scheduler support improves the CPU scheduler's decision
1036	  making when dealing with multi-core CPU chips at a cost of slightly
1037	  increased overhead in some places. If unsure say N here.
1038
1039config SCHED_MC_PRIO
1040	bool "CPU core priorities scheduler support"
1041	depends on SCHED_MC && CPU_SUP_INTEL
1042	select X86_INTEL_PSTATE
1043	select CPU_FREQ
1044	default y
1045	---help---
1046	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1047	  core ordering determined at manufacturing time, which allows
1048	  certain cores to reach higher turbo frequencies (when running
1049	  single threaded workloads) than others.
1050
1051	  Enabling this kernel feature teaches the scheduler about
1052	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1053	  scheduler's CPU selection logic accordingly, so that higher
1054	  overall system performance can be achieved.
1055
1056	  This feature will have no effect on CPUs without this feature.
1057
1058	  If unsure say Y here.
1059
1060config UP_LATE_INIT
1061       def_bool y
1062       depends on !SMP && X86_LOCAL_APIC
1063
1064config X86_UP_APIC
1065	bool "Local APIC support on uniprocessors" if !PCI_MSI
1066	default PCI_MSI
1067	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1068	---help---
1069	  A local APIC (Advanced Programmable Interrupt Controller) is an
1070	  integrated interrupt controller in the CPU. If you have a single-CPU
1071	  system which has a processor with a local APIC, you can say Y here to
1072	  enable and use it. If you say Y here even though your machine doesn't
1073	  have a local APIC, then the kernel will still run with no slowdown at
1074	  all. The local APIC supports CPU-generated self-interrupts (timer,
1075	  performance counters), and the NMI watchdog which detects hard
1076	  lockups.
1077
1078config X86_UP_IOAPIC
1079	bool "IO-APIC support on uniprocessors"
1080	depends on X86_UP_APIC
1081	---help---
1082	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1083	  SMP-capable replacement for PC-style interrupt controllers. Most
1084	  SMP systems and many recent uniprocessor systems have one.
1085
1086	  If you have a single-CPU system with an IO-APIC, you can say Y here
1087	  to use it. If you say Y here even though your machine doesn't have
1088	  an IO-APIC, then the kernel will still run with no slowdown at all.
1089
1090config X86_LOCAL_APIC
1091	def_bool y
1092	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1093	select IRQ_DOMAIN_HIERARCHY
1094	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1095
1096config X86_IO_APIC
1097	def_bool y
1098	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1099
1100config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1101	bool "Reroute for broken boot IRQs"
1102	depends on X86_IO_APIC
1103	---help---
1104	  This option enables a workaround that fixes a source of
1105	  spurious interrupts. This is recommended when threaded
1106	  interrupt handling is used on systems where the generation of
1107	  superfluous "boot interrupts" cannot be disabled.
1108
1109	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1110	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1111	  kernel does during interrupt handling). On chipsets where this
1112	  boot IRQ generation cannot be disabled, this workaround keeps
1113	  the original IRQ line masked so that only the equivalent "boot
1114	  IRQ" is delivered to the CPUs. The workaround also tells the
1115	  kernel to set up the IRQ handler on the boot IRQ line. In this
1116	  way only one interrupt is delivered to the kernel. Otherwise
1117	  the spurious second interrupt may cause the kernel to bring
1118	  down (vital) interrupt lines.
1119
1120	  Only affects "broken" chipsets. Interrupt sharing may be
1121	  increased on these systems.
1122
1123config X86_MCE
1124	bool "Machine Check / overheating reporting"
1125	select GENERIC_ALLOCATOR
1126	default y
1127	---help---
1128	  Machine Check support allows the processor to notify the
1129	  kernel if it detects a problem (e.g. overheating, data corruption).
1130	  The action the kernel takes depends on the severity of the problem,
1131	  ranging from warning messages to halting the machine.
1132
1133config X86_MCELOG_LEGACY
1134	bool "Support for deprecated /dev/mcelog character device"
1135	depends on X86_MCE
1136	---help---
1137	  Enable support for /dev/mcelog which is needed by the old mcelog
1138	  userspace logging daemon. Consider switching to the new generation
1139	  rasdaemon solution.
1140
1141config X86_MCE_INTEL
1142	def_bool y
1143	prompt "Intel MCE features"
1144	depends on X86_MCE && X86_LOCAL_APIC
1145	---help---
1146	   Additional support for intel specific MCE features such as
1147	   the thermal monitor.
1148
1149config X86_MCE_AMD
1150	def_bool y
1151	prompt "AMD MCE features"
1152	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1153	---help---
1154	   Additional support for AMD specific MCE features such as
1155	   the DRAM Error Threshold.
1156
1157config X86_ANCIENT_MCE
1158	bool "Support for old Pentium 5 / WinChip machine checks"
1159	depends on X86_32 && X86_MCE
1160	---help---
1161	  Include support for machine check handling on old Pentium 5 or WinChip
1162	  systems. These typically need to be enabled explicitly on the command
1163	  line.
1164
1165config X86_MCE_THRESHOLD
1166	depends on X86_MCE_AMD || X86_MCE_INTEL
1167	def_bool y
1168
1169config X86_MCE_INJECT
1170	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1171	tristate "Machine check injector support"
1172	---help---
1173	  Provide support for injecting machine checks for testing purposes.
1174	  If you don't know what a machine check is and you don't do kernel
1175	  QA it is safe to say n.
1176
1177config X86_THERMAL_VECTOR
1178	def_bool y
1179	depends on X86_MCE_INTEL
1180
1181source "arch/x86/events/Kconfig"
1182
1183config X86_LEGACY_VM86
1184	bool "Legacy VM86 support"
1185	depends on X86_32
1186	---help---
1187	  This option allows user programs to put the CPU into V8086
1188	  mode, which is an 80286-era approximation of 16-bit real mode.
1189
1190	  Some very old versions of X and/or vbetool require this option
1191	  for user mode setting.  Similarly, DOSEMU will use it if
1192	  available to accelerate real mode DOS programs.  However, any
1193	  recent version of DOSEMU, X, or vbetool should be fully
1194	  functional even without kernel VM86 support, as they will all
1195	  fall back to software emulation. Nevertheless, if you are using
1196	  a 16-bit DOS program where 16-bit performance matters, vm86
1197	  mode might be faster than emulation and you might want to
1198	  enable this option.
1199
1200	  Note that any app that works on a 64-bit kernel is unlikely to
1201	  need this option, as 64-bit kernels don't, and can't, support
1202	  V8086 mode. This option is also unrelated to 16-bit protected
1203	  mode and is not needed to run most 16-bit programs under Wine.
1204
1205	  Enabling this option increases the complexity of the kernel
1206	  and slows down exception handling a tiny bit.
1207
1208	  If unsure, say N here.
1209
1210config VM86
1211       bool
1212       default X86_LEGACY_VM86
1213
1214config X86_16BIT
1215	bool "Enable support for 16-bit segments" if EXPERT
1216	default y
1217	depends on MODIFY_LDT_SYSCALL
1218	---help---
1219	  This option is required by programs like Wine to run 16-bit
1220	  protected mode legacy code on x86 processors.  Disabling
1221	  this option saves about 300 bytes on i386, or around 6K text
1222	  plus 16K runtime memory on x86-64,
1223
1224config X86_ESPFIX32
1225	def_bool y
1226	depends on X86_16BIT && X86_32
1227
1228config X86_ESPFIX64
1229	def_bool y
1230	depends on X86_16BIT && X86_64
1231
1232config X86_VSYSCALL_EMULATION
1233       bool "Enable vsyscall emulation" if EXPERT
1234       default y
1235       depends on X86_64
1236       ---help---
1237	 This enables emulation of the legacy vsyscall page.  Disabling
1238	 it is roughly equivalent to booting with vsyscall=none, except
1239	 that it will also disable the helpful warning if a program
1240	 tries to use a vsyscall.  With this option set to N, offending
1241	 programs will just segfault, citing addresses of the form
1242	 0xffffffffff600?00.
1243
1244	 This option is required by many programs built before 2013, and
1245	 care should be used even with newer programs if set to N.
1246
1247	 Disabling this option saves about 7K of kernel size and
1248	 possibly 4K of additional runtime pagetable memory.
1249
1250config TOSHIBA
1251	tristate "Toshiba Laptop support"
1252	depends on X86_32
1253	---help---
1254	  This adds a driver to safely access the System Management Mode of
1255	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256	  not work on models with a Phoenix BIOS. The System Management Mode
1257	  is used to set the BIOS and power saving options on Toshiba portables.
1258
1259	  For information on utilities to make use of this driver see the
1260	  Toshiba Linux utilities web site at:
1261	  <http://www.buzzard.org.uk/toshiba/>.
1262
1263	  Say Y if you intend to run this kernel on a Toshiba portable.
1264	  Say N otherwise.
1265
1266config I8K
1267	tristate "Dell i8k legacy laptop support"
1268	select HWMON
1269	select SENSORS_DELL_SMM
1270	---help---
1271	  This option enables legacy /proc/i8k userspace interface in hwmon
1272	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273	  temperature and allows controlling fan speeds of Dell laptops via
1274	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275	  it reports also power and hotkey status. For fan speed control is
1276	  needed userspace package i8kutils.
1277
1278	  Say Y if you intend to run this kernel on old Dell laptops or want to
1279	  use userspace package i8kutils.
1280	  Say N otherwise.
1281
1282config X86_REBOOTFIXUPS
1283	bool "Enable X86 board specific fixups for reboot"
1284	depends on X86_32
1285	---help---
1286	  This enables chipset and/or board specific fixups to be done
1287	  in order to get reboot to work correctly. This is only needed on
1288	  some combinations of hardware and BIOS. The symptom, for which
1289	  this config is intended, is when reboot ends with a stalled/hung
1290	  system.
1291
1292	  Currently, the only fixup is for the Geode machines using
1293	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1294
1295	  Say Y if you want to enable the fixup. Currently, it's safe to
1296	  enable this option even if you don't need it.
1297	  Say N otherwise.
1298
1299config MICROCODE
1300	bool "CPU microcode loading support"
1301	default y
1302	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1303	select FW_LOADER
1304	---help---
1305	  If you say Y here, you will be able to update the microcode on
1306	  Intel and AMD processors. The Intel support is for the IA32 family,
1307	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1308	  AMD support is for families 0x10 and later. You will obviously need
1309	  the actual microcode binary data itself which is not shipped with
1310	  the Linux kernel.
1311
1312	  The preferred method to load microcode from a detached initrd is described
1313	  in Documentation/x86/microcode.rst. For that you need to enable
1314	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1315	  initrd for microcode blobs.
1316
1317	  In addition, you can build the microcode into the kernel. For that you
1318	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1319	  config option.
1320
1321config MICROCODE_INTEL
1322	bool "Intel microcode loading support"
1323	depends on MICROCODE
1324	default MICROCODE
1325	select FW_LOADER
1326	---help---
1327	  This options enables microcode patch loading support for Intel
1328	  processors.
1329
1330	  For the current Intel microcode data package go to
1331	  <https://downloadcenter.intel.com> and search for
1332	  'Linux Processor Microcode Data File'.
1333
1334config MICROCODE_AMD
1335	bool "AMD microcode loading support"
1336	depends on MICROCODE
1337	select FW_LOADER
1338	---help---
1339	  If you select this option, microcode patch loading support for AMD
1340	  processors will be enabled.
1341
1342config MICROCODE_OLD_INTERFACE
1343	bool "Ancient loading interface (DEPRECATED)"
1344	default n
1345	depends on MICROCODE
1346	---help---
1347	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1348	  which was used by userspace tools like iucode_tool and microcode.ctl.
1349	  It is inadequate because it runs too late to be able to properly
1350	  load microcode on a machine and it needs special tools. Instead, you
1351	  should've switched to the early loading method with the initrd or
1352	  builtin microcode by now: Documentation/x86/microcode.rst
1353
1354config X86_MSR
1355	tristate "/dev/cpu/*/msr - Model-specific register support"
1356	---help---
1357	  This device gives privileged processes access to the x86
1358	  Model-Specific Registers (MSRs).  It is a character device with
1359	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360	  MSR accesses are directed to a specific CPU on multi-processor
1361	  systems.
1362
1363config X86_CPUID
1364	tristate "/dev/cpu/*/cpuid - CPU information support"
1365	---help---
1366	  This device gives processes access to the x86 CPUID instruction to
1367	  be executed on a specific processor.  It is a character device
1368	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369	  /dev/cpu/31/cpuid.
1370
1371choice
1372	prompt "High Memory Support"
1373	default HIGHMEM4G
1374	depends on X86_32
1375
1376config NOHIGHMEM
1377	bool "off"
1378	---help---
1379	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380	  However, the address space of 32-bit x86 processors is only 4
1381	  Gigabytes large. That means that, if you have a large amount of
1382	  physical memory, not all of it can be "permanently mapped" by the
1383	  kernel. The physical memory that's not permanently mapped is called
1384	  "high memory".
1385
1386	  If you are compiling a kernel which will never run on a machine with
1387	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1388	  choice and suitable for most users). This will result in a "3GB/1GB"
1389	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1390	  space and the remaining part of the 4GB virtual memory space is used
1391	  by the kernel to permanently map as much physical memory as
1392	  possible.
1393
1394	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1395	  answer "4GB" here.
1396
1397	  If more than 4 Gigabytes is used then answer "64GB" here. This
1398	  selection turns Intel PAE (Physical Address Extension) mode on.
1399	  PAE implements 3-level paging on IA32 processors. PAE is fully
1400	  supported by Linux, PAE mode is implemented on all recent Intel
1401	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402	  then the kernel will not boot on CPUs that don't support PAE!
1403
1404	  The actual amount of total physical memory will either be
1405	  auto detected or can be forced by using a kernel command line option
1406	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1407	  your boot loader (lilo or loadlin) about how to pass options to the
1408	  kernel at boot time.)
1409
1410	  If unsure, say "off".
1411
1412config HIGHMEM4G
1413	bool "4GB"
1414	---help---
1415	  Select this if you have a 32-bit processor and between 1 and 4
1416	  gigabytes of physical RAM.
1417
1418config HIGHMEM64G
1419	bool "64GB"
1420	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1421	select X86_PAE
1422	---help---
1423	  Select this if you have a 32-bit processor and more than 4
1424	  gigabytes of physical RAM.
1425
1426endchoice
1427
1428choice
1429	prompt "Memory split" if EXPERT
1430	default VMSPLIT_3G
1431	depends on X86_32
1432	---help---
1433	  Select the desired split between kernel and user memory.
1434
1435	  If the address range available to the kernel is less than the
1436	  physical memory installed, the remaining memory will be available
1437	  as "high memory". Accessing high memory is a little more costly
1438	  than low memory, as it needs to be mapped into the kernel first.
1439	  Note that increasing the kernel address space limits the range
1440	  available to user programs, making the address space there
1441	  tighter.  Selecting anything other than the default 3G/1G split
1442	  will also likely make your kernel incompatible with binary-only
1443	  kernel modules.
1444
1445	  If you are not absolutely sure what you are doing, leave this
1446	  option alone!
1447
1448	config VMSPLIT_3G
1449		bool "3G/1G user/kernel split"
1450	config VMSPLIT_3G_OPT
1451		depends on !X86_PAE
1452		bool "3G/1G user/kernel split (for full 1G low memory)"
1453	config VMSPLIT_2G
1454		bool "2G/2G user/kernel split"
1455	config VMSPLIT_2G_OPT
1456		depends on !X86_PAE
1457		bool "2G/2G user/kernel split (for full 2G low memory)"
1458	config VMSPLIT_1G
1459		bool "1G/3G user/kernel split"
1460endchoice
1461
1462config PAGE_OFFSET
1463	hex
1464	default 0xB0000000 if VMSPLIT_3G_OPT
1465	default 0x80000000 if VMSPLIT_2G
1466	default 0x78000000 if VMSPLIT_2G_OPT
1467	default 0x40000000 if VMSPLIT_1G
1468	default 0xC0000000
1469	depends on X86_32
1470
1471config HIGHMEM
1472	def_bool y
1473	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1474
1475config X86_PAE
1476	bool "PAE (Physical Address Extension) Support"
1477	depends on X86_32 && !HIGHMEM4G
1478	select PHYS_ADDR_T_64BIT
1479	select SWIOTLB
1480	---help---
1481	  PAE is required for NX support, and furthermore enables
1482	  larger swapspace support for non-overcommit purposes. It
1483	  has the cost of more pagetable lookup overhead, and also
1484	  consumes more pagetable space per process.
1485
1486config X86_5LEVEL
1487	bool "Enable 5-level page tables support"
1488	select DYNAMIC_MEMORY_LAYOUT
1489	select SPARSEMEM_VMEMMAP
1490	depends on X86_64
1491	---help---
1492	  5-level paging enables access to larger address space:
1493	  upto 128 PiB of virtual address space and 4 PiB of
1494	  physical address space.
1495
1496	  It will be supported by future Intel CPUs.
1497
1498	  A kernel with the option enabled can be booted on machines that
1499	  support 4- or 5-level paging.
1500
1501	  See Documentation/x86/x86_64/5level-paging.rst for more
1502	  information.
1503
1504	  Say N if unsure.
1505
1506config X86_DIRECT_GBPAGES
1507	def_bool y
1508	depends on X86_64 && !DEBUG_PAGEALLOC
1509	---help---
1510	  Certain kernel features effectively disable kernel
1511	  linear 1 GB mappings (even if the CPU otherwise
1512	  supports them), so don't confuse the user by printing
1513	  that we have them enabled.
1514
1515config X86_CPA_STATISTICS
1516	bool "Enable statistic for Change Page Attribute"
1517	depends on DEBUG_FS
1518	---help---
1519	  Expose statistics about the Change Page Attribute mechanims, which
1520	  helps to determine the effectiveness of preserving large and huge
1521	  page mappings when mapping protections are changed.
1522
1523config ARCH_HAS_MEM_ENCRYPT
1524	def_bool y
1525
1526config AMD_MEM_ENCRYPT
1527	bool "AMD Secure Memory Encryption (SME) support"
1528	depends on X86_64 && CPU_SUP_AMD
1529	select DYNAMIC_PHYSICAL_MASK
1530	select ARCH_USE_MEMREMAP_PROT
1531	---help---
1532	  Say yes to enable support for the encryption of system memory.
1533	  This requires an AMD processor that supports Secure Memory
1534	  Encryption (SME).
1535
1536config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1537	bool "Activate AMD Secure Memory Encryption (SME) by default"
1538	default y
1539	depends on AMD_MEM_ENCRYPT
1540	---help---
1541	  Say yes to have system memory encrypted by default if running on
1542	  an AMD processor that supports Secure Memory Encryption (SME).
1543
1544	  If set to Y, then the encryption of system memory can be
1545	  deactivated with the mem_encrypt=off command line option.
1546
1547	  If set to N, then the encryption of system memory can be
1548	  activated with the mem_encrypt=on command line option.
1549
1550# Common NUMA Features
1551config NUMA
1552	bool "Numa Memory Allocation and Scheduler Support"
1553	depends on SMP
1554	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1555	default y if X86_BIGSMP
1556	---help---
1557	  Enable NUMA (Non Uniform Memory Access) support.
1558
1559	  The kernel will try to allocate memory used by a CPU on the
1560	  local memory controller of the CPU and add some more
1561	  NUMA awareness to the kernel.
1562
1563	  For 64-bit this is recommended if the system is Intel Core i7
1564	  (or later), AMD Opteron, or EM64T NUMA.
1565
1566	  For 32-bit this is only needed if you boot a 32-bit
1567	  kernel on a 64-bit NUMA platform.
1568
1569	  Otherwise, you should say N.
1570
1571config AMD_NUMA
1572	def_bool y
1573	prompt "Old style AMD Opteron NUMA detection"
1574	depends on X86_64 && NUMA && PCI
1575	---help---
1576	  Enable AMD NUMA node topology detection.  You should say Y here if
1577	  you have a multi processor AMD system. This uses an old method to
1578	  read the NUMA configuration directly from the builtin Northbridge
1579	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1580	  which also takes priority if both are compiled in.
1581
1582config X86_64_ACPI_NUMA
1583	def_bool y
1584	prompt "ACPI NUMA detection"
1585	depends on X86_64 && NUMA && ACPI && PCI
1586	select ACPI_NUMA
1587	---help---
1588	  Enable ACPI SRAT based node topology detection.
1589
1590# Some NUMA nodes have memory ranges that span
1591# other nodes.  Even though a pfn is valid and
1592# between a node's start and end pfns, it may not
1593# reside on that node.  See memmap_init_zone()
1594# for details.
1595config NODES_SPAN_OTHER_NODES
1596	def_bool y
1597	depends on X86_64_ACPI_NUMA
1598
1599config NUMA_EMU
1600	bool "NUMA emulation"
1601	depends on NUMA
1602	---help---
1603	  Enable NUMA emulation. A flat machine will be split
1604	  into virtual nodes when booted with "numa=fake=N", where N is the
1605	  number of nodes. This is only useful for debugging.
1606
1607config NODES_SHIFT
1608	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1609	range 1 10
1610	default "10" if MAXSMP
1611	default "6" if X86_64
1612	default "3"
1613	depends on NEED_MULTIPLE_NODES
1614	---help---
1615	  Specify the maximum number of NUMA Nodes available on the target
1616	  system.  Increases memory reserved to accommodate various tables.
1617
1618config ARCH_HAVE_MEMORY_PRESENT
1619	def_bool y
1620	depends on X86_32 && DISCONTIGMEM
1621
1622config ARCH_FLATMEM_ENABLE
1623	def_bool y
1624	depends on X86_32 && !NUMA
1625
1626config ARCH_DISCONTIGMEM_ENABLE
1627	def_bool n
1628	depends on NUMA && X86_32
1629	depends on BROKEN
1630
1631config ARCH_SPARSEMEM_ENABLE
1632	def_bool y
1633	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1634	select SPARSEMEM_STATIC if X86_32
1635	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1636
1637config ARCH_SPARSEMEM_DEFAULT
1638	def_bool X86_64 || (NUMA && X86_32)
1639
1640config ARCH_SELECT_MEMORY_MODEL
1641	def_bool y
1642	depends on ARCH_SPARSEMEM_ENABLE
1643
1644config ARCH_MEMORY_PROBE
1645	bool "Enable sysfs memory/probe interface"
1646	depends on X86_64 && MEMORY_HOTPLUG
1647	help
1648	  This option enables a sysfs memory/probe interface for testing.
1649	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1650	  If you are unsure how to answer this question, answer N.
1651
1652config ARCH_PROC_KCORE_TEXT
1653	def_bool y
1654	depends on X86_64 && PROC_KCORE
1655
1656config ILLEGAL_POINTER_VALUE
1657       hex
1658       default 0 if X86_32
1659       default 0xdead000000000000 if X86_64
1660
1661config X86_PMEM_LEGACY_DEVICE
1662	bool
1663
1664config X86_PMEM_LEGACY
1665	tristate "Support non-standard NVDIMMs and ADR protected memory"
1666	depends on PHYS_ADDR_T_64BIT
1667	depends on BLK_DEV
1668	select X86_PMEM_LEGACY_DEVICE
1669	select LIBNVDIMM
1670	help
1671	  Treat memory marked using the non-standard e820 type of 12 as used
1672	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1673	  The kernel will offer these regions to the 'pmem' driver so
1674	  they can be used for persistent storage.
1675
1676	  Say Y if unsure.
1677
1678config HIGHPTE
1679	bool "Allocate 3rd-level pagetables from highmem"
1680	depends on HIGHMEM
1681	---help---
1682	  The VM uses one page table entry for each page of physical memory.
1683	  For systems with a lot of RAM, this can be wasteful of precious
1684	  low memory.  Setting this option will put user-space page table
1685	  entries in high memory.
1686
1687config X86_CHECK_BIOS_CORRUPTION
1688	bool "Check for low memory corruption"
1689	---help---
1690	  Periodically check for memory corruption in low memory, which
1691	  is suspected to be caused by BIOS.  Even when enabled in the
1692	  configuration, it is disabled at runtime.  Enable it by
1693	  setting "memory_corruption_check=1" on the kernel command
1694	  line.  By default it scans the low 64k of memory every 60
1695	  seconds; see the memory_corruption_check_size and
1696	  memory_corruption_check_period parameters in
1697	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1698
1699	  When enabled with the default parameters, this option has
1700	  almost no overhead, as it reserves a relatively small amount
1701	  of memory and scans it infrequently.  It both detects corruption
1702	  and prevents it from affecting the running system.
1703
1704	  It is, however, intended as a diagnostic tool; if repeatable
1705	  BIOS-originated corruption always affects the same memory,
1706	  you can use memmap= to prevent the kernel from using that
1707	  memory.
1708
1709config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1710	bool "Set the default setting of memory_corruption_check"
1711	depends on X86_CHECK_BIOS_CORRUPTION
1712	default y
1713	---help---
1714	  Set whether the default state of memory_corruption_check is
1715	  on or off.
1716
1717config X86_RESERVE_LOW
1718	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1719	default 64
1720	range 4 640
1721	---help---
1722	  Specify the amount of low memory to reserve for the BIOS.
1723
1724	  The first page contains BIOS data structures that the kernel
1725	  must not use, so that page must always be reserved.
1726
1727	  By default we reserve the first 64K of physical RAM, as a
1728	  number of BIOSes are known to corrupt that memory range
1729	  during events such as suspend/resume or monitor cable
1730	  insertion, so it must not be used by the kernel.
1731
1732	  You can set this to 4 if you are absolutely sure that you
1733	  trust the BIOS to get all its memory reservations and usages
1734	  right.  If you know your BIOS have problems beyond the
1735	  default 64K area, you can set this to 640 to avoid using the
1736	  entire low memory range.
1737
1738	  If you have doubts about the BIOS (e.g. suspend/resume does
1739	  not work or there's kernel crashes after certain hardware
1740	  hotplug events) then you might want to enable
1741	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1742	  typical corruption patterns.
1743
1744	  Leave this to the default value of 64 if you are unsure.
1745
1746config MATH_EMULATION
1747	bool
1748	depends on MODIFY_LDT_SYSCALL
1749	prompt "Math emulation" if X86_32
1750	---help---
1751	  Linux can emulate a math coprocessor (used for floating point
1752	  operations) if you don't have one. 486DX and Pentium processors have
1753	  a math coprocessor built in, 486SX and 386 do not, unless you added
1754	  a 487DX or 387, respectively. (The messages during boot time can
1755	  give you some hints here ["man dmesg"].) Everyone needs either a
1756	  coprocessor or this emulation.
1757
1758	  If you don't have a math coprocessor, you need to say Y here; if you
1759	  say Y here even though you have a coprocessor, the coprocessor will
1760	  be used nevertheless. (This behavior can be changed with the kernel
1761	  command line option "no387", which comes handy if your coprocessor
1762	  is broken. Try "man bootparam" or see the documentation of your boot
1763	  loader (lilo or loadlin) about how to pass options to the kernel at
1764	  boot time.) This means that it is a good idea to say Y here if you
1765	  intend to use this kernel on different machines.
1766
1767	  More information about the internals of the Linux math coprocessor
1768	  emulation can be found in <file:arch/x86/math-emu/README>.
1769
1770	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1771	  kernel, it won't hurt.
1772
1773config MTRR
1774	def_bool y
1775	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1776	---help---
1777	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1778	  the Memory Type Range Registers (MTRRs) may be used to control
1779	  processor access to memory ranges. This is most useful if you have
1780	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1781	  allows bus write transfers to be combined into a larger transfer
1782	  before bursting over the PCI/AGP bus. This can increase performance
1783	  of image write operations 2.5 times or more. Saying Y here creates a
1784	  /proc/mtrr file which may be used to manipulate your processor's
1785	  MTRRs. Typically the X server should use this.
1786
1787	  This code has a reasonably generic interface so that similar
1788	  control registers on other processors can be easily supported
1789	  as well:
1790
1791	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1792	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1793	  these, the ARRs are used to emulate the MTRRs.
1794	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1795	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1796	  write-combining. All of these processors are supported by this code
1797	  and it makes sense to say Y here if you have one of them.
1798
1799	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1800	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1801	  can lead to all sorts of problems, so it's good to say Y here.
1802
1803	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1804	  just add about 9 KB to your kernel.
1805
1806	  See <file:Documentation/x86/mtrr.rst> for more information.
1807
1808config MTRR_SANITIZER
1809	def_bool y
1810	prompt "MTRR cleanup support"
1811	depends on MTRR
1812	---help---
1813	  Convert MTRR layout from continuous to discrete, so X drivers can
1814	  add writeback entries.
1815
1816	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1817	  The largest mtrr entry size for a continuous block can be set with
1818	  mtrr_chunk_size.
1819
1820	  If unsure, say Y.
1821
1822config MTRR_SANITIZER_ENABLE_DEFAULT
1823	int "MTRR cleanup enable value (0-1)"
1824	range 0 1
1825	default "0"
1826	depends on MTRR_SANITIZER
1827	---help---
1828	  Enable mtrr cleanup default value
1829
1830config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1831	int "MTRR cleanup spare reg num (0-7)"
1832	range 0 7
1833	default "1"
1834	depends on MTRR_SANITIZER
1835	---help---
1836	  mtrr cleanup spare entries default, it can be changed via
1837	  mtrr_spare_reg_nr=N on the kernel command line.
1838
1839config X86_PAT
1840	def_bool y
1841	prompt "x86 PAT support" if EXPERT
1842	depends on MTRR
1843	---help---
1844	  Use PAT attributes to setup page level cache control.
1845
1846	  PATs are the modern equivalents of MTRRs and are much more
1847	  flexible than MTRRs.
1848
1849	  Say N here if you see bootup problems (boot crash, boot hang,
1850	  spontaneous reboots) or a non-working video driver.
1851
1852	  If unsure, say Y.
1853
1854config ARCH_USES_PG_UNCACHED
1855	def_bool y
1856	depends on X86_PAT
1857
1858config ARCH_RANDOM
1859	def_bool y
1860	prompt "x86 architectural random number generator" if EXPERT
1861	---help---
1862	  Enable the x86 architectural RDRAND instruction
1863	  (Intel Bull Mountain technology) to generate random numbers.
1864	  If supported, this is a high bandwidth, cryptographically
1865	  secure hardware random number generator.
1866
1867config X86_SMAP
1868	def_bool y
1869	prompt "Supervisor Mode Access Prevention" if EXPERT
1870	---help---
1871	  Supervisor Mode Access Prevention (SMAP) is a security
1872	  feature in newer Intel processors.  There is a small
1873	  performance cost if this enabled and turned on; there is
1874	  also a small increase in the kernel size if this is enabled.
1875
1876	  If unsure, say Y.
1877
1878config X86_INTEL_UMIP
1879	def_bool y
1880	depends on CPU_SUP_INTEL
1881	prompt "Intel User Mode Instruction Prevention" if EXPERT
1882	---help---
1883	  The User Mode Instruction Prevention (UMIP) is a security
1884	  feature in newer Intel processors. If enabled, a general
1885	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1886	  or STR instructions are executed in user mode. These instructions
1887	  unnecessarily expose information about the hardware state.
1888
1889	  The vast majority of applications do not use these instructions.
1890	  For the very few that do, software emulation is provided in
1891	  specific cases in protected and virtual-8086 modes. Emulated
1892	  results are dummy.
1893
1894config X86_INTEL_MPX
1895	prompt "Intel MPX (Memory Protection Extensions)"
1896	def_bool n
1897	# Note: only available in 64-bit mode due to VMA flags shortage
1898	depends on CPU_SUP_INTEL && X86_64
1899	select ARCH_USES_HIGH_VMA_FLAGS
1900	---help---
1901	  MPX provides hardware features that can be used in
1902	  conjunction with compiler-instrumented code to check
1903	  memory references.  It is designed to detect buffer
1904	  overflow or underflow bugs.
1905
1906	  This option enables running applications which are
1907	  instrumented or otherwise use MPX.  It does not use MPX
1908	  itself inside the kernel or to protect the kernel
1909	  against bad memory references.
1910
1911	  Enabling this option will make the kernel larger:
1912	  ~8k of kernel text and 36 bytes of data on a 64-bit
1913	  defconfig.  It adds a long to the 'mm_struct' which
1914	  will increase the kernel memory overhead of each
1915	  process and adds some branches to paths used during
1916	  exec() and munmap().
1917
1918	  For details, see Documentation/x86/intel_mpx.rst
1919
1920	  If unsure, say N.
1921
1922config X86_INTEL_MEMORY_PROTECTION_KEYS
1923	prompt "Intel Memory Protection Keys"
1924	def_bool y
1925	# Note: only available in 64-bit mode
1926	depends on CPU_SUP_INTEL && X86_64
1927	select ARCH_USES_HIGH_VMA_FLAGS
1928	select ARCH_HAS_PKEYS
1929	---help---
1930	  Memory Protection Keys provides a mechanism for enforcing
1931	  page-based protections, but without requiring modification of the
1932	  page tables when an application changes protection domains.
1933
1934	  For details, see Documentation/core-api/protection-keys.rst
1935
1936	  If unsure, say y.
1937
1938config EFI
1939	bool "EFI runtime service support"
1940	depends on ACPI
1941	select UCS2_STRING
1942	select EFI_RUNTIME_WRAPPERS
1943	---help---
1944	  This enables the kernel to use EFI runtime services that are
1945	  available (such as the EFI variable services).
1946
1947	  This option is only useful on systems that have EFI firmware.
1948	  In addition, you should use the latest ELILO loader available
1949	  at <http://elilo.sourceforge.net> in order to take advantage
1950	  of EFI runtime services. However, even with this option, the
1951	  resultant kernel should continue to boot on existing non-EFI
1952	  platforms.
1953
1954config EFI_STUB
1955       bool "EFI stub support"
1956       depends on EFI && !X86_USE_3DNOW
1957       select RELOCATABLE
1958       ---help---
1959          This kernel feature allows a bzImage to be loaded directly
1960	  by EFI firmware without the use of a bootloader.
1961
1962	  See Documentation/admin-guide/efi-stub.rst for more information.
1963
1964config EFI_MIXED
1965	bool "EFI mixed-mode support"
1966	depends on EFI_STUB && X86_64
1967	---help---
1968	   Enabling this feature allows a 64-bit kernel to be booted
1969	   on a 32-bit firmware, provided that your CPU supports 64-bit
1970	   mode.
1971
1972	   Note that it is not possible to boot a mixed-mode enabled
1973	   kernel via the EFI boot stub - a bootloader that supports
1974	   the EFI handover protocol must be used.
1975
1976	   If unsure, say N.
1977
1978config SECCOMP
1979	def_bool y
1980	prompt "Enable seccomp to safely compute untrusted bytecode"
1981	---help---
1982	  This kernel feature is useful for number crunching applications
1983	  that may need to compute untrusted bytecode during their
1984	  execution. By using pipes or other transports made available to
1985	  the process as file descriptors supporting the read/write
1986	  syscalls, it's possible to isolate those applications in
1987	  their own address space using seccomp. Once seccomp is
1988	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1989	  and the task is only allowed to execute a few safe syscalls
1990	  defined by each seccomp mode.
1991
1992	  If unsure, say Y. Only embedded should say N here.
1993
1994source "kernel/Kconfig.hz"
1995
1996config KEXEC
1997	bool "kexec system call"
1998	select KEXEC_CORE
1999	---help---
2000	  kexec is a system call that implements the ability to shutdown your
2001	  current kernel, and to start another kernel.  It is like a reboot
2002	  but it is independent of the system firmware.   And like a reboot
2003	  you can start any kernel with it, not just Linux.
2004
2005	  The name comes from the similarity to the exec system call.
2006
2007	  It is an ongoing process to be certain the hardware in a machine
2008	  is properly shutdown, so do not be surprised if this code does not
2009	  initially work for you.  As of this writing the exact hardware
2010	  interface is strongly in flux, so no good recommendation can be
2011	  made.
2012
2013config KEXEC_FILE
2014	bool "kexec file based system call"
2015	select KEXEC_CORE
2016	select BUILD_BIN2C
2017	depends on X86_64
2018	depends on CRYPTO=y
2019	depends on CRYPTO_SHA256=y
2020	---help---
2021	  This is new version of kexec system call. This system call is
2022	  file based and takes file descriptors as system call argument
2023	  for kernel and initramfs as opposed to list of segments as
2024	  accepted by previous system call.
2025
2026config ARCH_HAS_KEXEC_PURGATORY
2027	def_bool KEXEC_FILE
2028
2029config KEXEC_VERIFY_SIG
2030	bool "Verify kernel signature during kexec_file_load() syscall"
2031	depends on KEXEC_FILE
2032	---help---
2033	  This option makes kernel signature verification mandatory for
2034	  the kexec_file_load() syscall.
2035
2036	  In addition to that option, you need to enable signature
2037	  verification for the corresponding kernel image type being
2038	  loaded in order for this to work.
2039
2040config KEXEC_BZIMAGE_VERIFY_SIG
2041	bool "Enable bzImage signature verification support"
2042	depends on KEXEC_VERIFY_SIG
2043	depends on SIGNED_PE_FILE_VERIFICATION
2044	select SYSTEM_TRUSTED_KEYRING
2045	---help---
2046	  Enable bzImage signature verification support.
2047
2048config CRASH_DUMP
2049	bool "kernel crash dumps"
2050	depends on X86_64 || (X86_32 && HIGHMEM)
2051	---help---
2052	  Generate crash dump after being started by kexec.
2053	  This should be normally only set in special crash dump kernels
2054	  which are loaded in the main kernel with kexec-tools into
2055	  a specially reserved region and then later executed after
2056	  a crash by kdump/kexec. The crash dump kernel must be compiled
2057	  to a memory address not used by the main kernel or BIOS using
2058	  PHYSICAL_START, or it must be built as a relocatable image
2059	  (CONFIG_RELOCATABLE=y).
2060	  For more details see Documentation/admin-guide/kdump/kdump.rst
2061
2062config KEXEC_JUMP
2063	bool "kexec jump"
2064	depends on KEXEC && HIBERNATION
2065	---help---
2066	  Jump between original kernel and kexeced kernel and invoke
2067	  code in physical address mode via KEXEC
2068
2069config PHYSICAL_START
2070	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2071	default "0x1000000"
2072	---help---
2073	  This gives the physical address where the kernel is loaded.
2074
2075	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2076	  bzImage will decompress itself to above physical address and
2077	  run from there. Otherwise, bzImage will run from the address where
2078	  it has been loaded by the boot loader and will ignore above physical
2079	  address.
2080
2081	  In normal kdump cases one does not have to set/change this option
2082	  as now bzImage can be compiled as a completely relocatable image
2083	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2084	  address. This option is mainly useful for the folks who don't want
2085	  to use a bzImage for capturing the crash dump and want to use a
2086	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2087	  to be specifically compiled to run from a specific memory area
2088	  (normally a reserved region) and this option comes handy.
2089
2090	  So if you are using bzImage for capturing the crash dump,
2091	  leave the value here unchanged to 0x1000000 and set
2092	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2093	  for capturing the crash dump change this value to start of
2094	  the reserved region.  In other words, it can be set based on
2095	  the "X" value as specified in the "crashkernel=YM@XM"
2096	  command line boot parameter passed to the panic-ed
2097	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2098	  for more details about crash dumps.
2099
2100	  Usage of bzImage for capturing the crash dump is recommended as
2101	  one does not have to build two kernels. Same kernel can be used
2102	  as production kernel and capture kernel. Above option should have
2103	  gone away after relocatable bzImage support is introduced. But it
2104	  is present because there are users out there who continue to use
2105	  vmlinux for dump capture. This option should go away down the
2106	  line.
2107
2108	  Don't change this unless you know what you are doing.
2109
2110config RELOCATABLE
2111	bool "Build a relocatable kernel"
2112	default y
2113	---help---
2114	  This builds a kernel image that retains relocation information
2115	  so it can be loaded someplace besides the default 1MB.
2116	  The relocations tend to make the kernel binary about 10% larger,
2117	  but are discarded at runtime.
2118
2119	  One use is for the kexec on panic case where the recovery kernel
2120	  must live at a different physical address than the primary
2121	  kernel.
2122
2123	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2124	  it has been loaded at and the compile time physical address
2125	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2126
2127config RANDOMIZE_BASE
2128	bool "Randomize the address of the kernel image (KASLR)"
2129	depends on RELOCATABLE
2130	default y
2131	---help---
2132	  In support of Kernel Address Space Layout Randomization (KASLR),
2133	  this randomizes the physical address at which the kernel image
2134	  is decompressed and the virtual address where the kernel
2135	  image is mapped, as a security feature that deters exploit
2136	  attempts relying on knowledge of the location of kernel
2137	  code internals.
2138
2139	  On 64-bit, the kernel physical and virtual addresses are
2140	  randomized separately. The physical address will be anywhere
2141	  between 16MB and the top of physical memory (up to 64TB). The
2142	  virtual address will be randomized from 16MB up to 1GB (9 bits
2143	  of entropy). Note that this also reduces the memory space
2144	  available to kernel modules from 1.5GB to 1GB.
2145
2146	  On 32-bit, the kernel physical and virtual addresses are
2147	  randomized together. They will be randomized from 16MB up to
2148	  512MB (8 bits of entropy).
2149
2150	  Entropy is generated using the RDRAND instruction if it is
2151	  supported. If RDTSC is supported, its value is mixed into
2152	  the entropy pool as well. If neither RDRAND nor RDTSC are
2153	  supported, then entropy is read from the i8254 timer. The
2154	  usable entropy is limited by the kernel being built using
2155	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2156	  minimum of 2MB. As a result, only 10 bits of entropy are
2157	  theoretically possible, but the implementations are further
2158	  limited due to memory layouts.
2159
2160	  If unsure, say Y.
2161
2162# Relocation on x86 needs some additional build support
2163config X86_NEED_RELOCS
2164	def_bool y
2165	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2166
2167config PHYSICAL_ALIGN
2168	hex "Alignment value to which kernel should be aligned"
2169	default "0x200000"
2170	range 0x2000 0x1000000 if X86_32
2171	range 0x200000 0x1000000 if X86_64
2172	---help---
2173	  This value puts the alignment restrictions on physical address
2174	  where kernel is loaded and run from. Kernel is compiled for an
2175	  address which meets above alignment restriction.
2176
2177	  If bootloader loads the kernel at a non-aligned address and
2178	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2179	  address aligned to above value and run from there.
2180
2181	  If bootloader loads the kernel at a non-aligned address and
2182	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2183	  load address and decompress itself to the address it has been
2184	  compiled for and run from there. The address for which kernel is
2185	  compiled already meets above alignment restrictions. Hence the
2186	  end result is that kernel runs from a physical address meeting
2187	  above alignment restrictions.
2188
2189	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2190	  this value must be a multiple of 0x200000.
2191
2192	  Don't change this unless you know what you are doing.
2193
2194config DYNAMIC_MEMORY_LAYOUT
2195	bool
2196	---help---
2197	  This option makes base addresses of vmalloc and vmemmap as well as
2198	  __PAGE_OFFSET movable during boot.
2199
2200config RANDOMIZE_MEMORY
2201	bool "Randomize the kernel memory sections"
2202	depends on X86_64
2203	depends on RANDOMIZE_BASE
2204	select DYNAMIC_MEMORY_LAYOUT
2205	default RANDOMIZE_BASE
2206	---help---
2207	   Randomizes the base virtual address of kernel memory sections
2208	   (physical memory mapping, vmalloc & vmemmap). This security feature
2209	   makes exploits relying on predictable memory locations less reliable.
2210
2211	   The order of allocations remains unchanged. Entropy is generated in
2212	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2213	   configuration have in average 30,000 different possible virtual
2214	   addresses for each memory section.
2215
2216	   If unsure, say Y.
2217
2218config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2219	hex "Physical memory mapping padding" if EXPERT
2220	depends on RANDOMIZE_MEMORY
2221	default "0xa" if MEMORY_HOTPLUG
2222	default "0x0"
2223	range 0x1 0x40 if MEMORY_HOTPLUG
2224	range 0x0 0x40
2225	---help---
2226	   Define the padding in terabytes added to the existing physical
2227	   memory size during kernel memory randomization. It is useful
2228	   for memory hotplug support but reduces the entropy available for
2229	   address randomization.
2230
2231	   If unsure, leave at the default value.
2232
2233config HOTPLUG_CPU
2234	def_bool y
2235	depends on SMP
2236
2237config BOOTPARAM_HOTPLUG_CPU0
2238	bool "Set default setting of cpu0_hotpluggable"
2239	depends on HOTPLUG_CPU
2240	---help---
2241	  Set whether default state of cpu0_hotpluggable is on or off.
2242
2243	  Say Y here to enable CPU0 hotplug by default. If this switch
2244	  is turned on, there is no need to give cpu0_hotplug kernel
2245	  parameter and the CPU0 hotplug feature is enabled by default.
2246
2247	  Please note: there are two known CPU0 dependencies if you want
2248	  to enable the CPU0 hotplug feature either by this switch or by
2249	  cpu0_hotplug kernel parameter.
2250
2251	  First, resume from hibernate or suspend always starts from CPU0.
2252	  So hibernate and suspend are prevented if CPU0 is offline.
2253
2254	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2255	  offline if any interrupt can not migrate out of CPU0. There may
2256	  be other CPU0 dependencies.
2257
2258	  Please make sure the dependencies are under your control before
2259	  you enable this feature.
2260
2261	  Say N if you don't want to enable CPU0 hotplug feature by default.
2262	  You still can enable the CPU0 hotplug feature at boot by kernel
2263	  parameter cpu0_hotplug.
2264
2265config DEBUG_HOTPLUG_CPU0
2266	def_bool n
2267	prompt "Debug CPU0 hotplug"
2268	depends on HOTPLUG_CPU
2269	---help---
2270	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2271	  soon as possible and boots up userspace with CPU0 offlined. User
2272	  can online CPU0 back after boot time.
2273
2274	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2275	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2276	  compilation or giving cpu0_hotplug kernel parameter at boot.
2277
2278	  If unsure, say N.
2279
2280config COMPAT_VDSO
2281	def_bool n
2282	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2283	depends on COMPAT_32
2284	---help---
2285	  Certain buggy versions of glibc will crash if they are
2286	  presented with a 32-bit vDSO that is not mapped at the address
2287	  indicated in its segment table.
2288
2289	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2290	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2291	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2292	  the only released version with the bug, but OpenSUSE 9
2293	  contains a buggy "glibc 2.3.2".
2294
2295	  The symptom of the bug is that everything crashes on startup, saying:
2296	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2297
2298	  Saying Y here changes the default value of the vdso32 boot
2299	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2300	  This works around the glibc bug but hurts performance.
2301
2302	  If unsure, say N: if you are compiling your own kernel, you
2303	  are unlikely to be using a buggy version of glibc.
2304
2305choice
2306	prompt "vsyscall table for legacy applications"
2307	depends on X86_64
2308	default LEGACY_VSYSCALL_XONLY
2309	help
2310	  Legacy user code that does not know how to find the vDSO expects
2311	  to be able to issue three syscalls by calling fixed addresses in
2312	  kernel space. Since this location is not randomized with ASLR,
2313	  it can be used to assist security vulnerability exploitation.
2314
2315	  This setting can be changed at boot time via the kernel command
2316	  line parameter vsyscall=[emulate|xonly|none].
2317
2318	  On a system with recent enough glibc (2.14 or newer) and no
2319	  static binaries, you can say None without a performance penalty
2320	  to improve security.
2321
2322	  If unsure, select "Emulate execution only".
2323
2324	config LEGACY_VSYSCALL_EMULATE
2325		bool "Full emulation"
2326		help
2327		  The kernel traps and emulates calls into the fixed vsyscall
2328		  address mapping. This makes the mapping non-executable, but
2329		  it still contains readable known contents, which could be
2330		  used in certain rare security vulnerability exploits. This
2331		  configuration is recommended when using legacy userspace
2332		  that still uses vsyscalls along with legacy binary
2333		  instrumentation tools that require code to be readable.
2334
2335		  An example of this type of legacy userspace is running
2336		  Pin on an old binary that still uses vsyscalls.
2337
2338	config LEGACY_VSYSCALL_XONLY
2339		bool "Emulate execution only"
2340		help
2341		  The kernel traps and emulates calls into the fixed vsyscall
2342		  address mapping and does not allow reads.  This
2343		  configuration is recommended when userspace might use the
2344		  legacy vsyscall area but support for legacy binary
2345		  instrumentation of legacy code is not needed.  It mitigates
2346		  certain uses of the vsyscall area as an ASLR-bypassing
2347		  buffer.
2348
2349	config LEGACY_VSYSCALL_NONE
2350		bool "None"
2351		help
2352		  There will be no vsyscall mapping at all. This will
2353		  eliminate any risk of ASLR bypass due to the vsyscall
2354		  fixed address mapping. Attempts to use the vsyscalls
2355		  will be reported to dmesg, so that either old or
2356		  malicious userspace programs can be identified.
2357
2358endchoice
2359
2360config CMDLINE_BOOL
2361	bool "Built-in kernel command line"
2362	---help---
2363	  Allow for specifying boot arguments to the kernel at
2364	  build time.  On some systems (e.g. embedded ones), it is
2365	  necessary or convenient to provide some or all of the
2366	  kernel boot arguments with the kernel itself (that is,
2367	  to not rely on the boot loader to provide them.)
2368
2369	  To compile command line arguments into the kernel,
2370	  set this option to 'Y', then fill in the
2371	  boot arguments in CONFIG_CMDLINE.
2372
2373	  Systems with fully functional boot loaders (i.e. non-embedded)
2374	  should leave this option set to 'N'.
2375
2376config CMDLINE
2377	string "Built-in kernel command string"
2378	depends on CMDLINE_BOOL
2379	default ""
2380	---help---
2381	  Enter arguments here that should be compiled into the kernel
2382	  image and used at boot time.  If the boot loader provides a
2383	  command line at boot time, it is appended to this string to
2384	  form the full kernel command line, when the system boots.
2385
2386	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2387	  change this behavior.
2388
2389	  In most cases, the command line (whether built-in or provided
2390	  by the boot loader) should specify the device for the root
2391	  file system.
2392
2393config CMDLINE_OVERRIDE
2394	bool "Built-in command line overrides boot loader arguments"
2395	depends on CMDLINE_BOOL
2396	---help---
2397	  Set this option to 'Y' to have the kernel ignore the boot loader
2398	  command line, and use ONLY the built-in command line.
2399
2400	  This is used to work around broken boot loaders.  This should
2401	  be set to 'N' under normal conditions.
2402
2403config MODIFY_LDT_SYSCALL
2404	bool "Enable the LDT (local descriptor table)" if EXPERT
2405	default y
2406	---help---
2407	  Linux can allow user programs to install a per-process x86
2408	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2409	  call.  This is required to run 16-bit or segmented code such as
2410	  DOSEMU or some Wine programs.  It is also used by some very old
2411	  threading libraries.
2412
2413	  Enabling this feature adds a small amount of overhead to
2414	  context switches and increases the low-level kernel attack
2415	  surface.  Disabling it removes the modify_ldt(2) system call.
2416
2417	  Saying 'N' here may make sense for embedded or server kernels.
2418
2419source "kernel/livepatch/Kconfig"
2420
2421endmenu
2422
2423config ARCH_HAS_ADD_PAGES
2424	def_bool y
2425	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2426
2427config ARCH_ENABLE_MEMORY_HOTPLUG
2428	def_bool y
2429	depends on X86_64 || (X86_32 && HIGHMEM)
2430
2431config ARCH_ENABLE_MEMORY_HOTREMOVE
2432	def_bool y
2433	depends on MEMORY_HOTPLUG
2434
2435config USE_PERCPU_NUMA_NODE_ID
2436	def_bool y
2437	depends on NUMA
2438
2439config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2440	def_bool y
2441	depends on X86_64 || X86_PAE
2442
2443config ARCH_ENABLE_HUGEPAGE_MIGRATION
2444	def_bool y
2445	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2446
2447config ARCH_ENABLE_THP_MIGRATION
2448	def_bool y
2449	depends on X86_64 && TRANSPARENT_HUGEPAGE
2450
2451menu "Power management and ACPI options"
2452
2453config ARCH_HIBERNATION_HEADER
2454	def_bool y
2455	depends on HIBERNATION
2456
2457source "kernel/power/Kconfig"
2458
2459source "drivers/acpi/Kconfig"
2460
2461source "drivers/sfi/Kconfig"
2462
2463config X86_APM_BOOT
2464	def_bool y
2465	depends on APM
2466
2467menuconfig APM
2468	tristate "APM (Advanced Power Management) BIOS support"
2469	depends on X86_32 && PM_SLEEP
2470	---help---
2471	  APM is a BIOS specification for saving power using several different
2472	  techniques. This is mostly useful for battery powered laptops with
2473	  APM compliant BIOSes. If you say Y here, the system time will be
2474	  reset after a RESUME operation, the /proc/apm device will provide
2475	  battery status information, and user-space programs will receive
2476	  notification of APM "events" (e.g. battery status change).
2477
2478	  If you select "Y" here, you can disable actual use of the APM
2479	  BIOS by passing the "apm=off" option to the kernel at boot time.
2480
2481	  Note that the APM support is almost completely disabled for
2482	  machines with more than one CPU.
2483
2484	  In order to use APM, you will need supporting software. For location
2485	  and more information, read <file:Documentation/power/apm-acpi.txt>
2486	  and the Battery Powered Linux mini-HOWTO, available from
2487	  <http://www.tldp.org/docs.html#howto>.
2488
2489	  This driver does not spin down disk drives (see the hdparm(8)
2490	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2491	  VESA-compliant "green" monitors.
2492
2493	  This driver does not support the TI 4000M TravelMate and the ACER
2494	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2495	  desktop machines also don't have compliant BIOSes, and this driver
2496	  may cause those machines to panic during the boot phase.
2497
2498	  Generally, if you don't have a battery in your machine, there isn't
2499	  much point in using this driver and you should say N. If you get
2500	  random kernel OOPSes or reboots that don't seem to be related to
2501	  anything, try disabling/enabling this option (or disabling/enabling
2502	  APM in your BIOS).
2503
2504	  Some other things you should try when experiencing seemingly random,
2505	  "weird" problems:
2506
2507	  1) make sure that you have enough swap space and that it is
2508	  enabled.
2509	  2) pass the "no-hlt" option to the kernel
2510	  3) switch on floating point emulation in the kernel and pass
2511	  the "no387" option to the kernel
2512	  4) pass the "floppy=nodma" option to the kernel
2513	  5) pass the "mem=4M" option to the kernel (thereby disabling
2514	  all but the first 4 MB of RAM)
2515	  6) make sure that the CPU is not over clocked.
2516	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2517	  8) disable the cache from your BIOS settings
2518	  9) install a fan for the video card or exchange video RAM
2519	  10) install a better fan for the CPU
2520	  11) exchange RAM chips
2521	  12) exchange the motherboard.
2522
2523	  To compile this driver as a module, choose M here: the
2524	  module will be called apm.
2525
2526if APM
2527
2528config APM_IGNORE_USER_SUSPEND
2529	bool "Ignore USER SUSPEND"
2530	---help---
2531	  This option will ignore USER SUSPEND requests. On machines with a
2532	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2533	  series notebooks, it is necessary to say Y because of a BIOS bug.
2534
2535config APM_DO_ENABLE
2536	bool "Enable PM at boot time"
2537	---help---
2538	  Enable APM features at boot time. From page 36 of the APM BIOS
2539	  specification: "When disabled, the APM BIOS does not automatically
2540	  power manage devices, enter the Standby State, enter the Suspend
2541	  State, or take power saving steps in response to CPU Idle calls."
2542	  This driver will make CPU Idle calls when Linux is idle (unless this
2543	  feature is turned off -- see "Do CPU IDLE calls", below). This
2544	  should always save battery power, but more complicated APM features
2545	  will be dependent on your BIOS implementation. You may need to turn
2546	  this option off if your computer hangs at boot time when using APM
2547	  support, or if it beeps continuously instead of suspending. Turn
2548	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2549	  T400CDT. This is off by default since most machines do fine without
2550	  this feature.
2551
2552config APM_CPU_IDLE
2553	depends on CPU_IDLE
2554	bool "Make CPU Idle calls when idle"
2555	---help---
2556	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2557	  On some machines, this can activate improved power savings, such as
2558	  a slowed CPU clock rate, when the machine is idle. These idle calls
2559	  are made after the idle loop has run for some length of time (e.g.,
2560	  333 mS). On some machines, this will cause a hang at boot time or
2561	  whenever the CPU becomes idle. (On machines with more than one CPU,
2562	  this option does nothing.)
2563
2564config APM_DISPLAY_BLANK
2565	bool "Enable console blanking using APM"
2566	---help---
2567	  Enable console blanking using the APM. Some laptops can use this to
2568	  turn off the LCD backlight when the screen blanker of the Linux
2569	  virtual console blanks the screen. Note that this is only used by
2570	  the virtual console screen blanker, and won't turn off the backlight
2571	  when using the X Window system. This also doesn't have anything to
2572	  do with your VESA-compliant power-saving monitor. Further, this
2573	  option doesn't work for all laptops -- it might not turn off your
2574	  backlight at all, or it might print a lot of errors to the console,
2575	  especially if you are using gpm.
2576
2577config APM_ALLOW_INTS
2578	bool "Allow interrupts during APM BIOS calls"
2579	---help---
2580	  Normally we disable external interrupts while we are making calls to
2581	  the APM BIOS as a measure to lessen the effects of a badly behaving
2582	  BIOS implementation.  The BIOS should reenable interrupts if it
2583	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2584	  many of the newer IBM Thinkpads.  If you experience hangs when you
2585	  suspend, try setting this to Y.  Otherwise, say N.
2586
2587endif # APM
2588
2589source "drivers/cpufreq/Kconfig"
2590
2591source "drivers/cpuidle/Kconfig"
2592
2593source "drivers/idle/Kconfig"
2594
2595endmenu
2596
2597
2598menu "Bus options (PCI etc.)"
2599
2600choice
2601	prompt "PCI access mode"
2602	depends on X86_32 && PCI
2603	default PCI_GOANY
2604	---help---
2605	  On PCI systems, the BIOS can be used to detect the PCI devices and
2606	  determine their configuration. However, some old PCI motherboards
2607	  have BIOS bugs and may crash if this is done. Also, some embedded
2608	  PCI-based systems don't have any BIOS at all. Linux can also try to
2609	  detect the PCI hardware directly without using the BIOS.
2610
2611	  With this option, you can specify how Linux should detect the
2612	  PCI devices. If you choose "BIOS", the BIOS will be used,
2613	  if you choose "Direct", the BIOS won't be used, and if you
2614	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2615	  If you choose "Any", the kernel will try MMCONFIG, then the
2616	  direct access method and falls back to the BIOS if that doesn't
2617	  work. If unsure, go with the default, which is "Any".
2618
2619config PCI_GOBIOS
2620	bool "BIOS"
2621
2622config PCI_GOMMCONFIG
2623	bool "MMConfig"
2624
2625config PCI_GODIRECT
2626	bool "Direct"
2627
2628config PCI_GOOLPC
2629	bool "OLPC XO-1"
2630	depends on OLPC
2631
2632config PCI_GOANY
2633	bool "Any"
2634
2635endchoice
2636
2637config PCI_BIOS
2638	def_bool y
2639	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2640
2641# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2642config PCI_DIRECT
2643	def_bool y
2644	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2645
2646config PCI_MMCONFIG
2647	bool "Support mmconfig PCI config space access" if X86_64
2648	default y
2649	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2650	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2651
2652config PCI_OLPC
2653	def_bool y
2654	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2655
2656config PCI_XEN
2657	def_bool y
2658	depends on PCI && XEN
2659	select SWIOTLB_XEN
2660
2661config MMCONF_FAM10H
2662	def_bool y
2663	depends on X86_64 && PCI_MMCONFIG && ACPI
2664
2665config PCI_CNB20LE_QUIRK
2666	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2667	depends on PCI
2668	help
2669	  Read the PCI windows out of the CNB20LE host bridge. This allows
2670	  PCI hotplug to work on systems with the CNB20LE chipset which do
2671	  not have ACPI.
2672
2673	  There's no public spec for this chipset, and this functionality
2674	  is known to be incomplete.
2675
2676	  You should say N unless you know you need this.
2677
2678config ISA_BUS
2679	bool "ISA bus support on modern systems" if EXPERT
2680	help
2681	  Expose ISA bus device drivers and options available for selection and
2682	  configuration. Enable this option if your target machine has an ISA
2683	  bus. ISA is an older system, displaced by PCI and newer bus
2684	  architectures -- if your target machine is modern, it probably does
2685	  not have an ISA bus.
2686
2687	  If unsure, say N.
2688
2689# x86_64 have no ISA slots, but can have ISA-style DMA.
2690config ISA_DMA_API
2691	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2692	default y
2693	help
2694	  Enables ISA-style DMA support for devices requiring such controllers.
2695	  If unsure, say Y.
2696
2697if X86_32
2698
2699config ISA
2700	bool "ISA support"
2701	---help---
2702	  Find out whether you have ISA slots on your motherboard.  ISA is the
2703	  name of a bus system, i.e. the way the CPU talks to the other stuff
2704	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2705	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2706	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2707
2708config SCx200
2709	tristate "NatSemi SCx200 support"
2710	---help---
2711	  This provides basic support for National Semiconductor's
2712	  (now AMD's) Geode processors.  The driver probes for the
2713	  PCI-IDs of several on-chip devices, so its a good dependency
2714	  for other scx200_* drivers.
2715
2716	  If compiled as a module, the driver is named scx200.
2717
2718config SCx200HR_TIMER
2719	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2720	depends on SCx200
2721	default y
2722	---help---
2723	  This driver provides a clocksource built upon the on-chip
2724	  27MHz high-resolution timer.  Its also a workaround for
2725	  NSC Geode SC-1100's buggy TSC, which loses time when the
2726	  processor goes idle (as is done by the scheduler).  The
2727	  other workaround is idle=poll boot option.
2728
2729config OLPC
2730	bool "One Laptop Per Child support"
2731	depends on !X86_PAE
2732	select GPIOLIB
2733	select OF
2734	select OF_PROMTREE
2735	select IRQ_DOMAIN
2736	select OLPC_EC
2737	---help---
2738	  Add support for detecting the unique features of the OLPC
2739	  XO hardware.
2740
2741config OLPC_XO1_PM
2742	bool "OLPC XO-1 Power Management"
2743	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2744	---help---
2745	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2746
2747config OLPC_XO1_RTC
2748	bool "OLPC XO-1 Real Time Clock"
2749	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2750	---help---
2751	  Add support for the XO-1 real time clock, which can be used as a
2752	  programmable wakeup source.
2753
2754config OLPC_XO1_SCI
2755	bool "OLPC XO-1 SCI extras"
2756	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2757	depends on INPUT=y
2758	select POWER_SUPPLY
2759	---help---
2760	  Add support for SCI-based features of the OLPC XO-1 laptop:
2761	   - EC-driven system wakeups
2762	   - Power button
2763	   - Ebook switch
2764	   - Lid switch
2765	   - AC adapter status updates
2766	   - Battery status updates
2767
2768config OLPC_XO15_SCI
2769	bool "OLPC XO-1.5 SCI extras"
2770	depends on OLPC && ACPI
2771	select POWER_SUPPLY
2772	---help---
2773	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2774	   - EC-driven system wakeups
2775	   - AC adapter status updates
2776	   - Battery status updates
2777
2778config ALIX
2779	bool "PCEngines ALIX System Support (LED setup)"
2780	select GPIOLIB
2781	---help---
2782	  This option enables system support for the PCEngines ALIX.
2783	  At present this just sets up LEDs for GPIO control on
2784	  ALIX2/3/6 boards.  However, other system specific setup should
2785	  get added here.
2786
2787	  Note: You must still enable the drivers for GPIO and LED support
2788	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2789
2790	  Note: You have to set alix.force=1 for boards with Award BIOS.
2791
2792config NET5501
2793	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2794	select GPIOLIB
2795	---help---
2796	  This option enables system support for the Soekris Engineering net5501.
2797
2798config GEOS
2799	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2800	select GPIOLIB
2801	depends on DMI
2802	---help---
2803	  This option enables system support for the Traverse Technologies GEOS.
2804
2805config TS5500
2806	bool "Technologic Systems TS-5500 platform support"
2807	depends on MELAN
2808	select CHECK_SIGNATURE
2809	select NEW_LEDS
2810	select LEDS_CLASS
2811	---help---
2812	  This option enables system support for the Technologic Systems TS-5500.
2813
2814endif # X86_32
2815
2816config AMD_NB
2817	def_bool y
2818	depends on CPU_SUP_AMD && PCI
2819
2820config X86_SYSFB
2821	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2822	help
2823	  Firmwares often provide initial graphics framebuffers so the BIOS,
2824	  bootloader or kernel can show basic video-output during boot for
2825	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2826	  Extensions and EFI-framebuffers for this, which are mostly limited
2827	  to x86.
2828	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2829	  framebuffers so the new generic system-framebuffer drivers can be
2830	  used on x86. If the framebuffer is not compatible with the generic
2831	  modes, it is advertised as fallback platform framebuffer so legacy
2832	  drivers like efifb, vesafb and uvesafb can pick it up.
2833	  If this option is not selected, all system framebuffers are always
2834	  marked as fallback platform framebuffers as usual.
2835
2836	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2837	  not be able to pick up generic system framebuffers if this option
2838	  is selected. You are highly encouraged to enable simplefb as
2839	  replacement if you select this option. simplefb can correctly deal
2840	  with generic system framebuffers. But you should still keep vesafb
2841	  and others enabled as fallback if a system framebuffer is
2842	  incompatible with simplefb.
2843
2844	  If unsure, say Y.
2845
2846endmenu
2847
2848
2849menu "Binary Emulations"
2850
2851config IA32_EMULATION
2852	bool "IA32 Emulation"
2853	depends on X86_64
2854	select ARCH_WANT_OLD_COMPAT_IPC
2855	select BINFMT_ELF
2856	select COMPAT_BINFMT_ELF
2857	select COMPAT_OLD_SIGACTION
2858	---help---
2859	  Include code to run legacy 32-bit programs under a
2860	  64-bit kernel. You should likely turn this on, unless you're
2861	  100% sure that you don't have any 32-bit programs left.
2862
2863config IA32_AOUT
2864	tristate "IA32 a.out support"
2865	depends on IA32_EMULATION
2866	depends on BROKEN
2867	---help---
2868	  Support old a.out binaries in the 32bit emulation.
2869
2870config X86_X32
2871	bool "x32 ABI for 64-bit mode"
2872	depends on X86_64
2873	---help---
2874	  Include code to run binaries for the x32 native 32-bit ABI
2875	  for 64-bit processors.  An x32 process gets access to the
2876	  full 64-bit register file and wide data path while leaving
2877	  pointers at 32 bits for smaller memory footprint.
2878
2879	  You will need a recent binutils (2.22 or later) with
2880	  elf32_x86_64 support enabled to compile a kernel with this
2881	  option set.
2882
2883config COMPAT_32
2884	def_bool y
2885	depends on IA32_EMULATION || X86_32
2886	select HAVE_UID16
2887	select OLD_SIGSUSPEND3
2888
2889config COMPAT
2890	def_bool y
2891	depends on IA32_EMULATION || X86_X32
2892
2893if COMPAT
2894config COMPAT_FOR_U64_ALIGNMENT
2895	def_bool y
2896
2897config SYSVIPC_COMPAT
2898	def_bool y
2899	depends on SYSVIPC
2900endif
2901
2902endmenu
2903
2904
2905config HAVE_ATOMIC_IOMAP
2906	def_bool y
2907	depends on X86_32
2908
2909config X86_DEV_DMA_OPS
2910	bool
2911
2912source "drivers/firmware/Kconfig"
2913
2914source "arch/x86/kvm/Kconfig"
2915