xref: /openbmc/linux/arch/x86/Kconfig (revision 752beb5e)
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
21config X86_64
22	def_bool y
23	depends on 64BIT
24	# Options that are inherently 64-bit kernel only:
25	select ARCH_HAS_GIGANTIC_PAGE
26	select ARCH_SUPPORTS_INT128
27	select ARCH_USE_CMPXCHG_LOCKREF
28	select HAVE_ARCH_SOFT_DIRTY
29	select MODULES_USE_ELF_RELA
30	select NEED_DMA_MAP_STATE
31	select SWIOTLB
32	select ARCH_HAS_SYSCALL_WRAPPER
33
34#
35# Arch settings
36#
37# ( Note that options that are marked 'if X86_64' could in principle be
38#   ported to 32-bit as well. )
39#
40config X86
41	def_bool y
42	#
43	# Note: keep this list sorted alphabetically
44	#
45	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
46	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
47	select ARCH_32BIT_OFF_T			if X86_32
48	select ARCH_CLOCKSOURCE_DATA
49	select ARCH_CLOCKSOURCE_INIT
50	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
51	select ARCH_HAS_DEBUG_VIRTUAL
52	select ARCH_HAS_DEVMEM_IS_ALLOWED
53	select ARCH_HAS_ELF_RANDOMIZE
54	select ARCH_HAS_FAST_MULTIPLIER
55	select ARCH_HAS_FILTER_PGPROT
56	select ARCH_HAS_FORTIFY_SOURCE
57	select ARCH_HAS_GCOV_PROFILE_ALL
58	select ARCH_HAS_KCOV			if X86_64
59	select ARCH_HAS_MEMBARRIER_SYNC_CORE
60	select ARCH_HAS_PMEM_API		if X86_64
61	select ARCH_HAS_PTE_SPECIAL
62	select ARCH_HAS_REFCOUNT
63	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
64	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
65	select ARCH_HAS_SET_MEMORY
66	select ARCH_HAS_SET_DIRECT_MAP
67	select ARCH_HAS_STRICT_KERNEL_RWX
68	select ARCH_HAS_STRICT_MODULE_RWX
69	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
70	select ARCH_HAS_UBSAN_SANITIZE_ALL
71	select ARCH_HAS_ZONE_DEVICE		if X86_64
72	select ARCH_HAVE_NMI_SAFE_CMPXCHG
73	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
74	select ARCH_MIGHT_HAVE_PC_PARPORT
75	select ARCH_MIGHT_HAVE_PC_SERIO
76	select ARCH_STACKWALK
77	select ARCH_SUPPORTS_ACPI
78	select ARCH_SUPPORTS_ATOMIC_RMW
79	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
80	select ARCH_USE_BUILTIN_BSWAP
81	select ARCH_USE_QUEUED_RWLOCKS
82	select ARCH_USE_QUEUED_SPINLOCKS
83	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
84	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
85	select ARCH_WANTS_THP_SWAP		if X86_64
86	select BUILDTIME_EXTABLE_SORT
87	select CLKEVT_I8253
88	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
89	select CLOCKSOURCE_WATCHDOG
90	select DCACHE_WORD_ACCESS
91	select EDAC_ATOMIC_SCRUB
92	select EDAC_SUPPORT
93	select GENERIC_CLOCKEVENTS
94	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
95	select GENERIC_CLOCKEVENTS_MIN_ADJUST
96	select GENERIC_CMOS_UPDATE
97	select GENERIC_CPU_AUTOPROBE
98	select GENERIC_CPU_VULNERABILITIES
99	select GENERIC_EARLY_IOREMAP
100	select GENERIC_FIND_FIRST_BIT
101	select GENERIC_IOMAP
102	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
103	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
104	select GENERIC_IRQ_MIGRATION		if SMP
105	select GENERIC_IRQ_PROBE
106	select GENERIC_IRQ_RESERVATION_MODE
107	select GENERIC_IRQ_SHOW
108	select GENERIC_PENDING_IRQ		if SMP
109	select GENERIC_SMP_IDLE_THREAD
110	select GENERIC_STRNCPY_FROM_USER
111	select GENERIC_STRNLEN_USER
112	select GENERIC_TIME_VSYSCALL
113	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
114	select HAVE_ACPI_APEI			if ACPI
115	select HAVE_ACPI_APEI_NMI		if ACPI
116	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
117	select HAVE_ARCH_AUDITSYSCALL
118	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
119	select HAVE_ARCH_JUMP_LABEL
120	select HAVE_ARCH_JUMP_LABEL_RELATIVE
121	select HAVE_ARCH_KASAN			if X86_64
122	select HAVE_ARCH_KGDB
123	select HAVE_ARCH_MMAP_RND_BITS		if MMU
124	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
125	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
126	select HAVE_ARCH_PREL32_RELOCATIONS
127	select HAVE_ARCH_SECCOMP_FILTER
128	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
129	select HAVE_ARCH_STACKLEAK
130	select HAVE_ARCH_TRACEHOOK
131	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
132	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
133	select HAVE_ARCH_VMAP_STACK		if X86_64
134	select HAVE_ARCH_WITHIN_STACK_FRAMES
135	select HAVE_CMPXCHG_DOUBLE
136	select HAVE_CMPXCHG_LOCAL
137	select HAVE_CONTEXT_TRACKING		if X86_64
138	select HAVE_COPY_THREAD_TLS
139	select HAVE_C_RECORDMCOUNT
140	select HAVE_DEBUG_KMEMLEAK
141	select HAVE_DMA_CONTIGUOUS
142	select HAVE_DYNAMIC_FTRACE
143	select HAVE_DYNAMIC_FTRACE_WITH_REGS
144	select HAVE_EBPF_JIT
145	select HAVE_EFFICIENT_UNALIGNED_ACCESS
146	select HAVE_EISA
147	select HAVE_EXIT_THREAD
148	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
149	select HAVE_FTRACE_MCOUNT_RECORD
150	select HAVE_FUNCTION_GRAPH_TRACER
151	select HAVE_FUNCTION_TRACER
152	select HAVE_GCC_PLUGINS
153	select HAVE_HW_BREAKPOINT
154	select HAVE_IDE
155	select HAVE_IOREMAP_PROT
156	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
157	select HAVE_IRQ_TIME_ACCOUNTING
158	select HAVE_KERNEL_BZIP2
159	select HAVE_KERNEL_GZIP
160	select HAVE_KERNEL_LZ4
161	select HAVE_KERNEL_LZMA
162	select HAVE_KERNEL_LZO
163	select HAVE_KERNEL_XZ
164	select HAVE_KPROBES
165	select HAVE_KPROBES_ON_FTRACE
166	select HAVE_FUNCTION_ERROR_INJECTION
167	select HAVE_KRETPROBES
168	select HAVE_KVM
169	select HAVE_LIVEPATCH			if X86_64
170	select HAVE_MEMBLOCK_NODE_MAP
171	select HAVE_MIXED_BREAKPOINTS_REGS
172	select HAVE_MOD_ARCH_SPECIFIC
173	select HAVE_MOVE_PMD
174	select HAVE_NMI
175	select HAVE_OPROFILE
176	select HAVE_OPTPROBES
177	select HAVE_PCSPKR_PLATFORM
178	select HAVE_PERF_EVENTS
179	select HAVE_PERF_EVENTS_NMI
180	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
181	select HAVE_PCI
182	select HAVE_PERF_REGS
183	select HAVE_PERF_USER_STACK_DUMP
184	select HAVE_RCU_TABLE_FREE		if PARAVIRT
185	select HAVE_REGS_AND_STACK_ACCESS_API
186	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
187	select HAVE_FUNCTION_ARG_ACCESS_API
188	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
189	select HAVE_STACK_VALIDATION		if X86_64
190	select HAVE_RSEQ
191	select HAVE_SYSCALL_TRACEPOINTS
192	select HAVE_UNSTABLE_SCHED_CLOCK
193	select HAVE_USER_RETURN_NOTIFIER
194	select HOTPLUG_SMT			if SMP
195	select IRQ_FORCED_THREADING
196	select NEED_SG_DMA_LENGTH
197	select PCI_DOMAINS			if PCI
198	select PCI_LOCKLESS_CONFIG		if PCI
199	select PERF_EVENTS
200	select RTC_LIB
201	select RTC_MC146818_LIB
202	select SPARSE_IRQ
203	select SRCU
204	select SYSCTL_EXCEPTION_TRACE
205	select THREAD_INFO_IN_TASK
206	select USER_STACKTRACE_SUPPORT
207	select VIRT_TO_BUS
208	select X86_FEATURE_NAMES		if PROC_FS
209
210config INSTRUCTION_DECODER
211	def_bool y
212	depends on KPROBES || PERF_EVENTS || UPROBES
213
214config OUTPUT_FORMAT
215	string
216	default "elf32-i386" if X86_32
217	default "elf64-x86-64" if X86_64
218
219config ARCH_DEFCONFIG
220	string
221	default "arch/x86/configs/i386_defconfig" if X86_32
222	default "arch/x86/configs/x86_64_defconfig" if X86_64
223
224config LOCKDEP_SUPPORT
225	def_bool y
226
227config STACKTRACE_SUPPORT
228	def_bool y
229
230config MMU
231	def_bool y
232
233config ARCH_MMAP_RND_BITS_MIN
234	default 28 if 64BIT
235	default 8
236
237config ARCH_MMAP_RND_BITS_MAX
238	default 32 if 64BIT
239	default 16
240
241config ARCH_MMAP_RND_COMPAT_BITS_MIN
242	default 8
243
244config ARCH_MMAP_RND_COMPAT_BITS_MAX
245	default 16
246
247config SBUS
248	bool
249
250config GENERIC_ISA_DMA
251	def_bool y
252	depends on ISA_DMA_API
253
254config GENERIC_BUG
255	def_bool y
256	depends on BUG
257	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
258
259config GENERIC_BUG_RELATIVE_POINTERS
260	bool
261
262config GENERIC_HWEIGHT
263	def_bool y
264
265config ARCH_MAY_HAVE_PC_FDC
266	def_bool y
267	depends on ISA_DMA_API
268
269config GENERIC_CALIBRATE_DELAY
270	def_bool y
271
272config ARCH_HAS_CPU_RELAX
273	def_bool y
274
275config ARCH_HAS_CACHE_LINE_SIZE
276	def_bool y
277
278config ARCH_HAS_FILTER_PGPROT
279	def_bool y
280
281config HAVE_SETUP_PER_CPU_AREA
282	def_bool y
283
284config NEED_PER_CPU_EMBED_FIRST_CHUNK
285	def_bool y
286
287config NEED_PER_CPU_PAGE_FIRST_CHUNK
288	def_bool y
289
290config ARCH_HIBERNATION_POSSIBLE
291	def_bool y
292
293config ARCH_SUSPEND_POSSIBLE
294	def_bool y
295
296config ARCH_WANT_HUGE_PMD_SHARE
297	def_bool y
298
299config ARCH_WANT_GENERAL_HUGETLB
300	def_bool y
301
302config ZONE_DMA32
303	def_bool y if X86_64
304
305config AUDIT_ARCH
306	def_bool y if X86_64
307
308config ARCH_SUPPORTS_OPTIMIZED_INLINING
309	def_bool y
310
311config ARCH_SUPPORTS_DEBUG_PAGEALLOC
312	def_bool y
313
314config KASAN_SHADOW_OFFSET
315	hex
316	depends on KASAN
317	default 0xdffffc0000000000
318
319config HAVE_INTEL_TXT
320	def_bool y
321	depends on INTEL_IOMMU && ACPI
322
323config X86_32_SMP
324	def_bool y
325	depends on X86_32 && SMP
326
327config X86_64_SMP
328	def_bool y
329	depends on X86_64 && SMP
330
331config X86_32_LAZY_GS
332	def_bool y
333	depends on X86_32 && !STACKPROTECTOR
334
335config ARCH_SUPPORTS_UPROBES
336	def_bool y
337
338config FIX_EARLYCON_MEM
339	def_bool y
340
341config DYNAMIC_PHYSICAL_MASK
342	bool
343
344config PGTABLE_LEVELS
345	int
346	default 5 if X86_5LEVEL
347	default 4 if X86_64
348	default 3 if X86_PAE
349	default 2
350
351config CC_HAS_SANE_STACKPROTECTOR
352	bool
353	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
354	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
355	help
356	   We have to make sure stack protector is unconditionally disabled if
357	   the compiler produces broken code.
358
359menu "Processor type and features"
360
361config ZONE_DMA
362	bool "DMA memory allocation support" if EXPERT
363	default y
364	help
365	  DMA memory allocation support allows devices with less than 32-bit
366	  addressing to allocate within the first 16MB of address space.
367	  Disable if no such devices will be used.
368
369	  If unsure, say Y.
370
371config SMP
372	bool "Symmetric multi-processing support"
373	---help---
374	  This enables support for systems with more than one CPU. If you have
375	  a system with only one CPU, say N. If you have a system with more
376	  than one CPU, say Y.
377
378	  If you say N here, the kernel will run on uni- and multiprocessor
379	  machines, but will use only one CPU of a multiprocessor machine. If
380	  you say Y here, the kernel will run on many, but not all,
381	  uniprocessor machines. On a uniprocessor machine, the kernel
382	  will run faster if you say N here.
383
384	  Note that if you say Y here and choose architecture "586" or
385	  "Pentium" under "Processor family", the kernel will not work on 486
386	  architectures. Similarly, multiprocessor kernels for the "PPro"
387	  architecture may not work on all Pentium based boards.
388
389	  People using multiprocessor machines who say Y here should also say
390	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
391	  Management" code will be disabled if you say Y here.
392
393	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
394	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
395	  <http://www.tldp.org/docs.html#howto>.
396
397	  If you don't know what to do here, say N.
398
399config X86_FEATURE_NAMES
400	bool "Processor feature human-readable names" if EMBEDDED
401	default y
402	---help---
403	  This option compiles in a table of x86 feature bits and corresponding
404	  names.  This is required to support /proc/cpuinfo and a few kernel
405	  messages.  You can disable this to save space, at the expense of
406	  making those few kernel messages show numeric feature bits instead.
407
408	  If in doubt, say Y.
409
410config X86_X2APIC
411	bool "Support x2apic"
412	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
413	---help---
414	  This enables x2apic support on CPUs that have this feature.
415
416	  This allows 32-bit apic IDs (so it can support very large systems),
417	  and accesses the local apic via MSRs not via mmio.
418
419	  If you don't know what to do here, say N.
420
421config X86_MPPARSE
422	bool "Enable MPS table" if ACPI || SFI
423	default y
424	depends on X86_LOCAL_APIC
425	---help---
426	  For old smp systems that do not have proper acpi support. Newer systems
427	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
428
429config GOLDFISH
430       def_bool y
431       depends on X86_GOLDFISH
432
433config RETPOLINE
434	bool "Avoid speculative indirect branches in kernel"
435	default y
436	select STACK_VALIDATION if HAVE_STACK_VALIDATION
437	help
438	  Compile kernel with the retpoline compiler options to guard against
439	  kernel-to-user data leaks by avoiding speculative indirect
440	  branches. Requires a compiler with -mindirect-branch=thunk-extern
441	  support for full protection. The kernel may run slower.
442
443config X86_CPU_RESCTRL
444	bool "x86 CPU resource control support"
445	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
446	select KERNFS
447	help
448	  Enable x86 CPU resource control support.
449
450	  Provide support for the allocation and monitoring of system resources
451	  usage by the CPU.
452
453	  Intel calls this Intel Resource Director Technology
454	  (Intel(R) RDT). More information about RDT can be found in the
455	  Intel x86 Architecture Software Developer Manual.
456
457	  AMD calls this AMD Platform Quality of Service (AMD QoS).
458	  More information about AMD QoS can be found in the AMD64 Technology
459	  Platform Quality of Service Extensions manual.
460
461	  Say N if unsure.
462
463if X86_32
464config X86_BIGSMP
465	bool "Support for big SMP systems with more than 8 CPUs"
466	depends on SMP
467	---help---
468	  This option is needed for the systems that have more than 8 CPUs
469
470config X86_EXTENDED_PLATFORM
471	bool "Support for extended (non-PC) x86 platforms"
472	default y
473	---help---
474	  If you disable this option then the kernel will only support
475	  standard PC platforms. (which covers the vast majority of
476	  systems out there.)
477
478	  If you enable this option then you'll be able to select support
479	  for the following (non-PC) 32 bit x86 platforms:
480		Goldfish (Android emulator)
481		AMD Elan
482		RDC R-321x SoC
483		SGI 320/540 (Visual Workstation)
484		STA2X11-based (e.g. Northville)
485		Moorestown MID devices
486
487	  If you have one of these systems, or if you want to build a
488	  generic distribution kernel, say Y here - otherwise say N.
489endif
490
491if X86_64
492config X86_EXTENDED_PLATFORM
493	bool "Support for extended (non-PC) x86 platforms"
494	default y
495	---help---
496	  If you disable this option then the kernel will only support
497	  standard PC platforms. (which covers the vast majority of
498	  systems out there.)
499
500	  If you enable this option then you'll be able to select support
501	  for the following (non-PC) 64 bit x86 platforms:
502		Numascale NumaChip
503		ScaleMP vSMP
504		SGI Ultraviolet
505
506	  If you have one of these systems, or if you want to build a
507	  generic distribution kernel, say Y here - otherwise say N.
508endif
509# This is an alphabetically sorted list of 64 bit extended platforms
510# Please maintain the alphabetic order if and when there are additions
511config X86_NUMACHIP
512	bool "Numascale NumaChip"
513	depends on X86_64
514	depends on X86_EXTENDED_PLATFORM
515	depends on NUMA
516	depends on SMP
517	depends on X86_X2APIC
518	depends on PCI_MMCONFIG
519	---help---
520	  Adds support for Numascale NumaChip large-SMP systems. Needed to
521	  enable more than ~168 cores.
522	  If you don't have one of these, you should say N here.
523
524config X86_VSMP
525	bool "ScaleMP vSMP"
526	select HYPERVISOR_GUEST
527	select PARAVIRT
528	depends on X86_64 && PCI
529	depends on X86_EXTENDED_PLATFORM
530	depends on SMP
531	---help---
532	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
533	  supposed to run on these EM64T-based machines.  Only choose this option
534	  if you have one of these machines.
535
536config X86_UV
537	bool "SGI Ultraviolet"
538	depends on X86_64
539	depends on X86_EXTENDED_PLATFORM
540	depends on NUMA
541	depends on EFI
542	depends on X86_X2APIC
543	depends on PCI
544	---help---
545	  This option is needed in order to support SGI Ultraviolet systems.
546	  If you don't have one of these, you should say N here.
547
548# Following is an alphabetically sorted list of 32 bit extended platforms
549# Please maintain the alphabetic order if and when there are additions
550
551config X86_GOLDFISH
552       bool "Goldfish (Virtual Platform)"
553       depends on X86_EXTENDED_PLATFORM
554       ---help---
555	 Enable support for the Goldfish virtual platform used primarily
556	 for Android development. Unless you are building for the Android
557	 Goldfish emulator say N here.
558
559config X86_INTEL_CE
560	bool "CE4100 TV platform"
561	depends on PCI
562	depends on PCI_GODIRECT
563	depends on X86_IO_APIC
564	depends on X86_32
565	depends on X86_EXTENDED_PLATFORM
566	select X86_REBOOTFIXUPS
567	select OF
568	select OF_EARLY_FLATTREE
569	---help---
570	  Select for the Intel CE media processor (CE4100) SOC.
571	  This option compiles in support for the CE4100 SOC for settop
572	  boxes and media devices.
573
574config X86_INTEL_MID
575	bool "Intel MID platform support"
576	depends on X86_EXTENDED_PLATFORM
577	depends on X86_PLATFORM_DEVICES
578	depends on PCI
579	depends on X86_64 || (PCI_GOANY && X86_32)
580	depends on X86_IO_APIC
581	select SFI
582	select I2C
583	select DW_APB_TIMER
584	select APB_TIMER
585	select INTEL_SCU_IPC
586	select MFD_INTEL_MSIC
587	---help---
588	  Select to build a kernel capable of supporting Intel MID (Mobile
589	  Internet Device) platform systems which do not have the PCI legacy
590	  interfaces. If you are building for a PC class system say N here.
591
592	  Intel MID platforms are based on an Intel processor and chipset which
593	  consume less power than most of the x86 derivatives.
594
595config X86_INTEL_QUARK
596	bool "Intel Quark platform support"
597	depends on X86_32
598	depends on X86_EXTENDED_PLATFORM
599	depends on X86_PLATFORM_DEVICES
600	depends on X86_TSC
601	depends on PCI
602	depends on PCI_GOANY
603	depends on X86_IO_APIC
604	select IOSF_MBI
605	select INTEL_IMR
606	select COMMON_CLK
607	---help---
608	  Select to include support for Quark X1000 SoC.
609	  Say Y here if you have a Quark based system such as the Arduino
610	  compatible Intel Galileo.
611
612config X86_INTEL_LPSS
613	bool "Intel Low Power Subsystem Support"
614	depends on X86 && ACPI && PCI
615	select COMMON_CLK
616	select PINCTRL
617	select IOSF_MBI
618	---help---
619	  Select to build support for Intel Low Power Subsystem such as
620	  found on Intel Lynxpoint PCH. Selecting this option enables
621	  things like clock tree (common clock framework) and pincontrol
622	  which are needed by the LPSS peripheral drivers.
623
624config X86_AMD_PLATFORM_DEVICE
625	bool "AMD ACPI2Platform devices support"
626	depends on ACPI
627	select COMMON_CLK
628	select PINCTRL
629	---help---
630	  Select to interpret AMD specific ACPI device to platform device
631	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
632	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
633	  implemented under PINCTRL subsystem.
634
635config IOSF_MBI
636	tristate "Intel SoC IOSF Sideband support for SoC platforms"
637	depends on PCI
638	---help---
639	  This option enables sideband register access support for Intel SoC
640	  platforms. On these platforms the IOSF sideband is used in lieu of
641	  MSR's for some register accesses, mostly but not limited to thermal
642	  and power. Drivers may query the availability of this device to
643	  determine if they need the sideband in order to work on these
644	  platforms. The sideband is available on the following SoC products.
645	  This list is not meant to be exclusive.
646	   - BayTrail
647	   - Braswell
648	   - Quark
649
650	  You should say Y if you are running a kernel on one of these SoC's.
651
652config IOSF_MBI_DEBUG
653	bool "Enable IOSF sideband access through debugfs"
654	depends on IOSF_MBI && DEBUG_FS
655	---help---
656	  Select this option to expose the IOSF sideband access registers (MCR,
657	  MDR, MCRX) through debugfs to write and read register information from
658	  different units on the SoC. This is most useful for obtaining device
659	  state information for debug and analysis. As this is a general access
660	  mechanism, users of this option would have specific knowledge of the
661	  device they want to access.
662
663	  If you don't require the option or are in doubt, say N.
664
665config X86_RDC321X
666	bool "RDC R-321x SoC"
667	depends on X86_32
668	depends on X86_EXTENDED_PLATFORM
669	select M486
670	select X86_REBOOTFIXUPS
671	---help---
672	  This option is needed for RDC R-321x system-on-chip, also known
673	  as R-8610-(G).
674	  If you don't have one of these chips, you should say N here.
675
676config X86_32_NON_STANDARD
677	bool "Support non-standard 32-bit SMP architectures"
678	depends on X86_32 && SMP
679	depends on X86_EXTENDED_PLATFORM
680	---help---
681	  This option compiles in the bigsmp and STA2X11 default
682	  subarchitectures.  It is intended for a generic binary
683	  kernel. If you select them all, kernel will probe it one by
684	  one and will fallback to default.
685
686# Alphabetically sorted list of Non standard 32 bit platforms
687
688config X86_SUPPORTS_MEMORY_FAILURE
689	def_bool y
690	# MCE code calls memory_failure():
691	depends on X86_MCE
692	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
693	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
694	depends on X86_64 || !SPARSEMEM
695	select ARCH_SUPPORTS_MEMORY_FAILURE
696
697config STA2X11
698	bool "STA2X11 Companion Chip Support"
699	depends on X86_32_NON_STANDARD && PCI
700	select ARCH_HAS_PHYS_TO_DMA
701	select SWIOTLB
702	select MFD_STA2X11
703	select GPIOLIB
704	---help---
705	  This adds support for boards based on the STA2X11 IO-Hub,
706	  a.k.a. "ConneXt". The chip is used in place of the standard
707	  PC chipset, so all "standard" peripherals are missing. If this
708	  option is selected the kernel will still be able to boot on
709	  standard PC machines.
710
711config X86_32_IRIS
712	tristate "Eurobraille/Iris poweroff module"
713	depends on X86_32
714	---help---
715	  The Iris machines from EuroBraille do not have APM or ACPI support
716	  to shut themselves down properly.  A special I/O sequence is
717	  needed to do so, which is what this module does at
718	  kernel shutdown.
719
720	  This is only for Iris machines from EuroBraille.
721
722	  If unused, say N.
723
724config SCHED_OMIT_FRAME_POINTER
725	def_bool y
726	prompt "Single-depth WCHAN output"
727	depends on X86
728	---help---
729	  Calculate simpler /proc/<PID>/wchan values. If this option
730	  is disabled then wchan values will recurse back to the
731	  caller function. This provides more accurate wchan values,
732	  at the expense of slightly more scheduling overhead.
733
734	  If in doubt, say "Y".
735
736menuconfig HYPERVISOR_GUEST
737	bool "Linux guest support"
738	---help---
739	  Say Y here to enable options for running Linux under various hyper-
740	  visors. This option enables basic hypervisor detection and platform
741	  setup.
742
743	  If you say N, all options in this submenu will be skipped and
744	  disabled, and Linux guest support won't be built in.
745
746if HYPERVISOR_GUEST
747
748config PARAVIRT
749	bool "Enable paravirtualization code"
750	---help---
751	  This changes the kernel so it can modify itself when it is run
752	  under a hypervisor, potentially improving performance significantly
753	  over full virtualization.  However, when run without a hypervisor
754	  the kernel is theoretically slower and slightly larger.
755
756config PARAVIRT_XXL
757	bool
758
759config PARAVIRT_DEBUG
760	bool "paravirt-ops debugging"
761	depends on PARAVIRT && DEBUG_KERNEL
762	---help---
763	  Enable to debug paravirt_ops internals.  Specifically, BUG if
764	  a paravirt_op is missing when it is called.
765
766config PARAVIRT_SPINLOCKS
767	bool "Paravirtualization layer for spinlocks"
768	depends on PARAVIRT && SMP
769	---help---
770	  Paravirtualized spinlocks allow a pvops backend to replace the
771	  spinlock implementation with something virtualization-friendly
772	  (for example, block the virtual CPU rather than spinning).
773
774	  It has a minimal impact on native kernels and gives a nice performance
775	  benefit on paravirtualized KVM / Xen kernels.
776
777	  If you are unsure how to answer this question, answer Y.
778
779source "arch/x86/xen/Kconfig"
780
781config KVM_GUEST
782	bool "KVM Guest support (including kvmclock)"
783	depends on PARAVIRT
784	select PARAVIRT_CLOCK
785	default y
786	---help---
787	  This option enables various optimizations for running under the KVM
788	  hypervisor. It includes a paravirtualized clock, so that instead
789	  of relying on a PIT (or probably other) emulation by the
790	  underlying device model, the host provides the guest with
791	  timing infrastructure such as time of day, and system time
792
793config PVH
794	bool "Support for running PVH guests"
795	---help---
796	  This option enables the PVH entry point for guest virtual machines
797	  as specified in the x86/HVM direct boot ABI.
798
799config KVM_DEBUG_FS
800	bool "Enable debug information for KVM Guests in debugfs"
801	depends on KVM_GUEST && DEBUG_FS
802	---help---
803	  This option enables collection of various statistics for KVM guest.
804	  Statistics are displayed in debugfs filesystem. Enabling this option
805	  may incur significant overhead.
806
807config PARAVIRT_TIME_ACCOUNTING
808	bool "Paravirtual steal time accounting"
809	depends on PARAVIRT
810	---help---
811	  Select this option to enable fine granularity task steal time
812	  accounting. Time spent executing other tasks in parallel with
813	  the current vCPU is discounted from the vCPU power. To account for
814	  that, there can be a small performance impact.
815
816	  If in doubt, say N here.
817
818config PARAVIRT_CLOCK
819	bool
820
821config JAILHOUSE_GUEST
822	bool "Jailhouse non-root cell support"
823	depends on X86_64 && PCI
824	select X86_PM_TIMER
825	---help---
826	  This option allows to run Linux as guest in a Jailhouse non-root
827	  cell. You can leave this option disabled if you only want to start
828	  Jailhouse and run Linux afterwards in the root cell.
829
830endif #HYPERVISOR_GUEST
831
832source "arch/x86/Kconfig.cpu"
833
834config HPET_TIMER
835	def_bool X86_64
836	prompt "HPET Timer Support" if X86_32
837	---help---
838	  Use the IA-PC HPET (High Precision Event Timer) to manage
839	  time in preference to the PIT and RTC, if a HPET is
840	  present.
841	  HPET is the next generation timer replacing legacy 8254s.
842	  The HPET provides a stable time base on SMP
843	  systems, unlike the TSC, but it is more expensive to access,
844	  as it is off-chip.  The interface used is documented
845	  in the HPET spec, revision 1.
846
847	  You can safely choose Y here.  However, HPET will only be
848	  activated if the platform and the BIOS support this feature.
849	  Otherwise the 8254 will be used for timing services.
850
851	  Choose N to continue using the legacy 8254 timer.
852
853config HPET_EMULATE_RTC
854	def_bool y
855	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
856
857config APB_TIMER
858       def_bool y if X86_INTEL_MID
859       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
860       select DW_APB_TIMER
861       depends on X86_INTEL_MID && SFI
862       help
863         APB timer is the replacement for 8254, HPET on X86 MID platforms.
864         The APBT provides a stable time base on SMP
865         systems, unlike the TSC, but it is more expensive to access,
866         as it is off-chip. APB timers are always running regardless of CPU
867         C states, they are used as per CPU clockevent device when possible.
868
869# Mark as expert because too many people got it wrong.
870# The code disables itself when not needed.
871config DMI
872	default y
873	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
874	bool "Enable DMI scanning" if EXPERT
875	---help---
876	  Enabled scanning of DMI to identify machine quirks. Say Y
877	  here unless you have verified that your setup is not
878	  affected by entries in the DMI blacklist. Required by PNP
879	  BIOS code.
880
881config GART_IOMMU
882	bool "Old AMD GART IOMMU support"
883	select IOMMU_HELPER
884	select SWIOTLB
885	depends on X86_64 && PCI && AMD_NB
886	---help---
887	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
888	  GART based hardware IOMMUs.
889
890	  The GART supports full DMA access for devices with 32-bit access
891	  limitations, on systems with more than 3 GB. This is usually needed
892	  for USB, sound, many IDE/SATA chipsets and some other devices.
893
894	  Newer systems typically have a modern AMD IOMMU, supported via
895	  the CONFIG_AMD_IOMMU=y config option.
896
897	  In normal configurations this driver is only active when needed:
898	  there's more than 3 GB of memory and the system contains a
899	  32-bit limited device.
900
901	  If unsure, say Y.
902
903config CALGARY_IOMMU
904	bool "IBM Calgary IOMMU support"
905	select IOMMU_HELPER
906	select SWIOTLB
907	depends on X86_64 && PCI
908	---help---
909	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
910	  systems. Needed to run systems with more than 3GB of memory
911	  properly with 32-bit PCI devices that do not support DAC
912	  (Double Address Cycle). Calgary also supports bus level
913	  isolation, where all DMAs pass through the IOMMU.  This
914	  prevents them from going anywhere except their intended
915	  destination. This catches hard-to-find kernel bugs and
916	  mis-behaving drivers and devices that do not use the DMA-API
917	  properly to set up their DMA buffers.  The IOMMU can be
918	  turned off at boot time with the iommu=off parameter.
919	  Normally the kernel will make the right choice by itself.
920	  If unsure, say Y.
921
922config CALGARY_IOMMU_ENABLED_BY_DEFAULT
923	def_bool y
924	prompt "Should Calgary be enabled by default?"
925	depends on CALGARY_IOMMU
926	---help---
927	  Should Calgary be enabled by default? if you choose 'y', Calgary
928	  will be used (if it exists). If you choose 'n', Calgary will not be
929	  used even if it exists. If you choose 'n' and would like to use
930	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
931	  If unsure, say Y.
932
933config MAXSMP
934	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
935	depends on X86_64 && SMP && DEBUG_KERNEL
936	select CPUMASK_OFFSTACK
937	---help---
938	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
939	  If unsure, say N.
940
941#
942# The maximum number of CPUs supported:
943#
944# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
945# and which can be configured interactively in the
946# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
947#
948# The ranges are different on 32-bit and 64-bit kernels, depending on
949# hardware capabilities and scalability features of the kernel.
950#
951# ( If MAXSMP is enabled we just use the highest possible value and disable
952#   interactive configuration. )
953#
954
955config NR_CPUS_RANGE_BEGIN
956	int
957	default NR_CPUS_RANGE_END if MAXSMP
958	default    1 if !SMP
959	default    2
960
961config NR_CPUS_RANGE_END
962	int
963	depends on X86_32
964	default   64 if  SMP &&  X86_BIGSMP
965	default    8 if  SMP && !X86_BIGSMP
966	default    1 if !SMP
967
968config NR_CPUS_RANGE_END
969	int
970	depends on X86_64
971	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
972	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
973	default    1 if !SMP
974
975config NR_CPUS_DEFAULT
976	int
977	depends on X86_32
978	default   32 if  X86_BIGSMP
979	default    8 if  SMP
980	default    1 if !SMP
981
982config NR_CPUS_DEFAULT
983	int
984	depends on X86_64
985	default 8192 if  MAXSMP
986	default   64 if  SMP
987	default    1 if !SMP
988
989config NR_CPUS
990	int "Maximum number of CPUs" if SMP && !MAXSMP
991	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
992	default NR_CPUS_DEFAULT
993	---help---
994	  This allows you to specify the maximum number of CPUs which this
995	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
996	  supported value is 8192, otherwise the maximum value is 512.  The
997	  minimum value which makes sense is 2.
998
999	  This is purely to save memory: each supported CPU adds about 8KB
1000	  to the kernel image.
1001
1002config SCHED_SMT
1003	def_bool y if SMP
1004
1005config SCHED_MC
1006	def_bool y
1007	prompt "Multi-core scheduler support"
1008	depends on SMP
1009	---help---
1010	  Multi-core scheduler support improves the CPU scheduler's decision
1011	  making when dealing with multi-core CPU chips at a cost of slightly
1012	  increased overhead in some places. If unsure say N here.
1013
1014config SCHED_MC_PRIO
1015	bool "CPU core priorities scheduler support"
1016	depends on SCHED_MC && CPU_SUP_INTEL
1017	select X86_INTEL_PSTATE
1018	select CPU_FREQ
1019	default y
1020	---help---
1021	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1022	  core ordering determined at manufacturing time, which allows
1023	  certain cores to reach higher turbo frequencies (when running
1024	  single threaded workloads) than others.
1025
1026	  Enabling this kernel feature teaches the scheduler about
1027	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1028	  scheduler's CPU selection logic accordingly, so that higher
1029	  overall system performance can be achieved.
1030
1031	  This feature will have no effect on CPUs without this feature.
1032
1033	  If unsure say Y here.
1034
1035config UP_LATE_INIT
1036       def_bool y
1037       depends on !SMP && X86_LOCAL_APIC
1038
1039config X86_UP_APIC
1040	bool "Local APIC support on uniprocessors" if !PCI_MSI
1041	default PCI_MSI
1042	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1043	---help---
1044	  A local APIC (Advanced Programmable Interrupt Controller) is an
1045	  integrated interrupt controller in the CPU. If you have a single-CPU
1046	  system which has a processor with a local APIC, you can say Y here to
1047	  enable and use it. If you say Y here even though your machine doesn't
1048	  have a local APIC, then the kernel will still run with no slowdown at
1049	  all. The local APIC supports CPU-generated self-interrupts (timer,
1050	  performance counters), and the NMI watchdog which detects hard
1051	  lockups.
1052
1053config X86_UP_IOAPIC
1054	bool "IO-APIC support on uniprocessors"
1055	depends on X86_UP_APIC
1056	---help---
1057	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1058	  SMP-capable replacement for PC-style interrupt controllers. Most
1059	  SMP systems and many recent uniprocessor systems have one.
1060
1061	  If you have a single-CPU system with an IO-APIC, you can say Y here
1062	  to use it. If you say Y here even though your machine doesn't have
1063	  an IO-APIC, then the kernel will still run with no slowdown at all.
1064
1065config X86_LOCAL_APIC
1066	def_bool y
1067	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1068	select IRQ_DOMAIN_HIERARCHY
1069	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1070
1071config X86_IO_APIC
1072	def_bool y
1073	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1074
1075config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1076	bool "Reroute for broken boot IRQs"
1077	depends on X86_IO_APIC
1078	---help---
1079	  This option enables a workaround that fixes a source of
1080	  spurious interrupts. This is recommended when threaded
1081	  interrupt handling is used on systems where the generation of
1082	  superfluous "boot interrupts" cannot be disabled.
1083
1084	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1085	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1086	  kernel does during interrupt handling). On chipsets where this
1087	  boot IRQ generation cannot be disabled, this workaround keeps
1088	  the original IRQ line masked so that only the equivalent "boot
1089	  IRQ" is delivered to the CPUs. The workaround also tells the
1090	  kernel to set up the IRQ handler on the boot IRQ line. In this
1091	  way only one interrupt is delivered to the kernel. Otherwise
1092	  the spurious second interrupt may cause the kernel to bring
1093	  down (vital) interrupt lines.
1094
1095	  Only affects "broken" chipsets. Interrupt sharing may be
1096	  increased on these systems.
1097
1098config X86_MCE
1099	bool "Machine Check / overheating reporting"
1100	select GENERIC_ALLOCATOR
1101	default y
1102	---help---
1103	  Machine Check support allows the processor to notify the
1104	  kernel if it detects a problem (e.g. overheating, data corruption).
1105	  The action the kernel takes depends on the severity of the problem,
1106	  ranging from warning messages to halting the machine.
1107
1108config X86_MCELOG_LEGACY
1109	bool "Support for deprecated /dev/mcelog character device"
1110	depends on X86_MCE
1111	---help---
1112	  Enable support for /dev/mcelog which is needed by the old mcelog
1113	  userspace logging daemon. Consider switching to the new generation
1114	  rasdaemon solution.
1115
1116config X86_MCE_INTEL
1117	def_bool y
1118	prompt "Intel MCE features"
1119	depends on X86_MCE && X86_LOCAL_APIC
1120	---help---
1121	   Additional support for intel specific MCE features such as
1122	   the thermal monitor.
1123
1124config X86_MCE_AMD
1125	def_bool y
1126	prompt "AMD MCE features"
1127	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1128	---help---
1129	   Additional support for AMD specific MCE features such as
1130	   the DRAM Error Threshold.
1131
1132config X86_ANCIENT_MCE
1133	bool "Support for old Pentium 5 / WinChip machine checks"
1134	depends on X86_32 && X86_MCE
1135	---help---
1136	  Include support for machine check handling on old Pentium 5 or WinChip
1137	  systems. These typically need to be enabled explicitly on the command
1138	  line.
1139
1140config X86_MCE_THRESHOLD
1141	depends on X86_MCE_AMD || X86_MCE_INTEL
1142	def_bool y
1143
1144config X86_MCE_INJECT
1145	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1146	tristate "Machine check injector support"
1147	---help---
1148	  Provide support for injecting machine checks for testing purposes.
1149	  If you don't know what a machine check is and you don't do kernel
1150	  QA it is safe to say n.
1151
1152config X86_THERMAL_VECTOR
1153	def_bool y
1154	depends on X86_MCE_INTEL
1155
1156source "arch/x86/events/Kconfig"
1157
1158config X86_LEGACY_VM86
1159	bool "Legacy VM86 support"
1160	depends on X86_32
1161	---help---
1162	  This option allows user programs to put the CPU into V8086
1163	  mode, which is an 80286-era approximation of 16-bit real mode.
1164
1165	  Some very old versions of X and/or vbetool require this option
1166	  for user mode setting.  Similarly, DOSEMU will use it if
1167	  available to accelerate real mode DOS programs.  However, any
1168	  recent version of DOSEMU, X, or vbetool should be fully
1169	  functional even without kernel VM86 support, as they will all
1170	  fall back to software emulation. Nevertheless, if you are using
1171	  a 16-bit DOS program where 16-bit performance matters, vm86
1172	  mode might be faster than emulation and you might want to
1173	  enable this option.
1174
1175	  Note that any app that works on a 64-bit kernel is unlikely to
1176	  need this option, as 64-bit kernels don't, and can't, support
1177	  V8086 mode. This option is also unrelated to 16-bit protected
1178	  mode and is not needed to run most 16-bit programs under Wine.
1179
1180	  Enabling this option increases the complexity of the kernel
1181	  and slows down exception handling a tiny bit.
1182
1183	  If unsure, say N here.
1184
1185config VM86
1186       bool
1187       default X86_LEGACY_VM86
1188
1189config X86_16BIT
1190	bool "Enable support for 16-bit segments" if EXPERT
1191	default y
1192	depends on MODIFY_LDT_SYSCALL
1193	---help---
1194	  This option is required by programs like Wine to run 16-bit
1195	  protected mode legacy code on x86 processors.  Disabling
1196	  this option saves about 300 bytes on i386, or around 6K text
1197	  plus 16K runtime memory on x86-64,
1198
1199config X86_ESPFIX32
1200	def_bool y
1201	depends on X86_16BIT && X86_32
1202
1203config X86_ESPFIX64
1204	def_bool y
1205	depends on X86_16BIT && X86_64
1206
1207config X86_VSYSCALL_EMULATION
1208       bool "Enable vsyscall emulation" if EXPERT
1209       default y
1210       depends on X86_64
1211       ---help---
1212	 This enables emulation of the legacy vsyscall page.  Disabling
1213	 it is roughly equivalent to booting with vsyscall=none, except
1214	 that it will also disable the helpful warning if a program
1215	 tries to use a vsyscall.  With this option set to N, offending
1216	 programs will just segfault, citing addresses of the form
1217	 0xffffffffff600?00.
1218
1219	 This option is required by many programs built before 2013, and
1220	 care should be used even with newer programs if set to N.
1221
1222	 Disabling this option saves about 7K of kernel size and
1223	 possibly 4K of additional runtime pagetable memory.
1224
1225config TOSHIBA
1226	tristate "Toshiba Laptop support"
1227	depends on X86_32
1228	---help---
1229	  This adds a driver to safely access the System Management Mode of
1230	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1231	  not work on models with a Phoenix BIOS. The System Management Mode
1232	  is used to set the BIOS and power saving options on Toshiba portables.
1233
1234	  For information on utilities to make use of this driver see the
1235	  Toshiba Linux utilities web site at:
1236	  <http://www.buzzard.org.uk/toshiba/>.
1237
1238	  Say Y if you intend to run this kernel on a Toshiba portable.
1239	  Say N otherwise.
1240
1241config I8K
1242	tristate "Dell i8k legacy laptop support"
1243	select HWMON
1244	select SENSORS_DELL_SMM
1245	---help---
1246	  This option enables legacy /proc/i8k userspace interface in hwmon
1247	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1248	  temperature and allows controlling fan speeds of Dell laptops via
1249	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1250	  it reports also power and hotkey status. For fan speed control is
1251	  needed userspace package i8kutils.
1252
1253	  Say Y if you intend to run this kernel on old Dell laptops or want to
1254	  use userspace package i8kutils.
1255	  Say N otherwise.
1256
1257config X86_REBOOTFIXUPS
1258	bool "Enable X86 board specific fixups for reboot"
1259	depends on X86_32
1260	---help---
1261	  This enables chipset and/or board specific fixups to be done
1262	  in order to get reboot to work correctly. This is only needed on
1263	  some combinations of hardware and BIOS. The symptom, for which
1264	  this config is intended, is when reboot ends with a stalled/hung
1265	  system.
1266
1267	  Currently, the only fixup is for the Geode machines using
1268	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1269
1270	  Say Y if you want to enable the fixup. Currently, it's safe to
1271	  enable this option even if you don't need it.
1272	  Say N otherwise.
1273
1274config MICROCODE
1275	bool "CPU microcode loading support"
1276	default y
1277	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1278	select FW_LOADER
1279	---help---
1280	  If you say Y here, you will be able to update the microcode on
1281	  Intel and AMD processors. The Intel support is for the IA32 family,
1282	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1283	  AMD support is for families 0x10 and later. You will obviously need
1284	  the actual microcode binary data itself which is not shipped with
1285	  the Linux kernel.
1286
1287	  The preferred method to load microcode from a detached initrd is described
1288	  in Documentation/x86/microcode.txt. For that you need to enable
1289	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1290	  initrd for microcode blobs.
1291
1292	  In addition, you can build the microcode into the kernel. For that you
1293	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1294	  config option.
1295
1296config MICROCODE_INTEL
1297	bool "Intel microcode loading support"
1298	depends on MICROCODE
1299	default MICROCODE
1300	select FW_LOADER
1301	---help---
1302	  This options enables microcode patch loading support for Intel
1303	  processors.
1304
1305	  For the current Intel microcode data package go to
1306	  <https://downloadcenter.intel.com> and search for
1307	  'Linux Processor Microcode Data File'.
1308
1309config MICROCODE_AMD
1310	bool "AMD microcode loading support"
1311	depends on MICROCODE
1312	select FW_LOADER
1313	---help---
1314	  If you select this option, microcode patch loading support for AMD
1315	  processors will be enabled.
1316
1317config MICROCODE_OLD_INTERFACE
1318	bool "Ancient loading interface (DEPRECATED)"
1319	default n
1320	depends on MICROCODE
1321	---help---
1322	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1323	  which was used by userspace tools like iucode_tool and microcode.ctl.
1324	  It is inadequate because it runs too late to be able to properly
1325	  load microcode on a machine and it needs special tools. Instead, you
1326	  should've switched to the early loading method with the initrd or
1327	  builtin microcode by now: Documentation/x86/microcode.txt
1328
1329config X86_MSR
1330	tristate "/dev/cpu/*/msr - Model-specific register support"
1331	---help---
1332	  This device gives privileged processes access to the x86
1333	  Model-Specific Registers (MSRs).  It is a character device with
1334	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1335	  MSR accesses are directed to a specific CPU on multi-processor
1336	  systems.
1337
1338config X86_CPUID
1339	tristate "/dev/cpu/*/cpuid - CPU information support"
1340	---help---
1341	  This device gives processes access to the x86 CPUID instruction to
1342	  be executed on a specific processor.  It is a character device
1343	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1344	  /dev/cpu/31/cpuid.
1345
1346choice
1347	prompt "High Memory Support"
1348	default HIGHMEM4G
1349	depends on X86_32
1350
1351config NOHIGHMEM
1352	bool "off"
1353	---help---
1354	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1355	  However, the address space of 32-bit x86 processors is only 4
1356	  Gigabytes large. That means that, if you have a large amount of
1357	  physical memory, not all of it can be "permanently mapped" by the
1358	  kernel. The physical memory that's not permanently mapped is called
1359	  "high memory".
1360
1361	  If you are compiling a kernel which will never run on a machine with
1362	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1363	  choice and suitable for most users). This will result in a "3GB/1GB"
1364	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1365	  space and the remaining part of the 4GB virtual memory space is used
1366	  by the kernel to permanently map as much physical memory as
1367	  possible.
1368
1369	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1370	  answer "4GB" here.
1371
1372	  If more than 4 Gigabytes is used then answer "64GB" here. This
1373	  selection turns Intel PAE (Physical Address Extension) mode on.
1374	  PAE implements 3-level paging on IA32 processors. PAE is fully
1375	  supported by Linux, PAE mode is implemented on all recent Intel
1376	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1377	  then the kernel will not boot on CPUs that don't support PAE!
1378
1379	  The actual amount of total physical memory will either be
1380	  auto detected or can be forced by using a kernel command line option
1381	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1382	  your boot loader (lilo or loadlin) about how to pass options to the
1383	  kernel at boot time.)
1384
1385	  If unsure, say "off".
1386
1387config HIGHMEM4G
1388	bool "4GB"
1389	---help---
1390	  Select this if you have a 32-bit processor and between 1 and 4
1391	  gigabytes of physical RAM.
1392
1393config HIGHMEM64G
1394	bool "64GB"
1395	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1396	select X86_PAE
1397	---help---
1398	  Select this if you have a 32-bit processor and more than 4
1399	  gigabytes of physical RAM.
1400
1401endchoice
1402
1403choice
1404	prompt "Memory split" if EXPERT
1405	default VMSPLIT_3G
1406	depends on X86_32
1407	---help---
1408	  Select the desired split between kernel and user memory.
1409
1410	  If the address range available to the kernel is less than the
1411	  physical memory installed, the remaining memory will be available
1412	  as "high memory". Accessing high memory is a little more costly
1413	  than low memory, as it needs to be mapped into the kernel first.
1414	  Note that increasing the kernel address space limits the range
1415	  available to user programs, making the address space there
1416	  tighter.  Selecting anything other than the default 3G/1G split
1417	  will also likely make your kernel incompatible with binary-only
1418	  kernel modules.
1419
1420	  If you are not absolutely sure what you are doing, leave this
1421	  option alone!
1422
1423	config VMSPLIT_3G
1424		bool "3G/1G user/kernel split"
1425	config VMSPLIT_3G_OPT
1426		depends on !X86_PAE
1427		bool "3G/1G user/kernel split (for full 1G low memory)"
1428	config VMSPLIT_2G
1429		bool "2G/2G user/kernel split"
1430	config VMSPLIT_2G_OPT
1431		depends on !X86_PAE
1432		bool "2G/2G user/kernel split (for full 2G low memory)"
1433	config VMSPLIT_1G
1434		bool "1G/3G user/kernel split"
1435endchoice
1436
1437config PAGE_OFFSET
1438	hex
1439	default 0xB0000000 if VMSPLIT_3G_OPT
1440	default 0x80000000 if VMSPLIT_2G
1441	default 0x78000000 if VMSPLIT_2G_OPT
1442	default 0x40000000 if VMSPLIT_1G
1443	default 0xC0000000
1444	depends on X86_32
1445
1446config HIGHMEM
1447	def_bool y
1448	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1449
1450config X86_PAE
1451	bool "PAE (Physical Address Extension) Support"
1452	depends on X86_32 && !HIGHMEM4G
1453	select PHYS_ADDR_T_64BIT
1454	select SWIOTLB
1455	---help---
1456	  PAE is required for NX support, and furthermore enables
1457	  larger swapspace support for non-overcommit purposes. It
1458	  has the cost of more pagetable lookup overhead, and also
1459	  consumes more pagetable space per process.
1460
1461config X86_5LEVEL
1462	bool "Enable 5-level page tables support"
1463	select DYNAMIC_MEMORY_LAYOUT
1464	select SPARSEMEM_VMEMMAP
1465	depends on X86_64
1466	---help---
1467	  5-level paging enables access to larger address space:
1468	  upto 128 PiB of virtual address space and 4 PiB of
1469	  physical address space.
1470
1471	  It will be supported by future Intel CPUs.
1472
1473	  A kernel with the option enabled can be booted on machines that
1474	  support 4- or 5-level paging.
1475
1476	  See Documentation/x86/x86_64/5level-paging.txt for more
1477	  information.
1478
1479	  Say N if unsure.
1480
1481config X86_DIRECT_GBPAGES
1482	def_bool y
1483	depends on X86_64 && !DEBUG_PAGEALLOC
1484	---help---
1485	  Certain kernel features effectively disable kernel
1486	  linear 1 GB mappings (even if the CPU otherwise
1487	  supports them), so don't confuse the user by printing
1488	  that we have them enabled.
1489
1490config X86_CPA_STATISTICS
1491	bool "Enable statistic for Change Page Attribute"
1492	depends on DEBUG_FS
1493	---help---
1494	  Expose statistics about the Change Page Attribute mechanims, which
1495	  helps to determine the effectiveness of preserving large and huge
1496	  page mappings when mapping protections are changed.
1497
1498config ARCH_HAS_MEM_ENCRYPT
1499	def_bool y
1500
1501config AMD_MEM_ENCRYPT
1502	bool "AMD Secure Memory Encryption (SME) support"
1503	depends on X86_64 && CPU_SUP_AMD
1504	select DYNAMIC_PHYSICAL_MASK
1505	select ARCH_USE_MEMREMAP_PROT
1506	---help---
1507	  Say yes to enable support for the encryption of system memory.
1508	  This requires an AMD processor that supports Secure Memory
1509	  Encryption (SME).
1510
1511config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1512	bool "Activate AMD Secure Memory Encryption (SME) by default"
1513	default y
1514	depends on AMD_MEM_ENCRYPT
1515	---help---
1516	  Say yes to have system memory encrypted by default if running on
1517	  an AMD processor that supports Secure Memory Encryption (SME).
1518
1519	  If set to Y, then the encryption of system memory can be
1520	  deactivated with the mem_encrypt=off command line option.
1521
1522	  If set to N, then the encryption of system memory can be
1523	  activated with the mem_encrypt=on command line option.
1524
1525# Common NUMA Features
1526config NUMA
1527	bool "Numa Memory Allocation and Scheduler Support"
1528	depends on SMP
1529	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1530	default y if X86_BIGSMP
1531	---help---
1532	  Enable NUMA (Non Uniform Memory Access) support.
1533
1534	  The kernel will try to allocate memory used by a CPU on the
1535	  local memory controller of the CPU and add some more
1536	  NUMA awareness to the kernel.
1537
1538	  For 64-bit this is recommended if the system is Intel Core i7
1539	  (or later), AMD Opteron, or EM64T NUMA.
1540
1541	  For 32-bit this is only needed if you boot a 32-bit
1542	  kernel on a 64-bit NUMA platform.
1543
1544	  Otherwise, you should say N.
1545
1546config AMD_NUMA
1547	def_bool y
1548	prompt "Old style AMD Opteron NUMA detection"
1549	depends on X86_64 && NUMA && PCI
1550	---help---
1551	  Enable AMD NUMA node topology detection.  You should say Y here if
1552	  you have a multi processor AMD system. This uses an old method to
1553	  read the NUMA configuration directly from the builtin Northbridge
1554	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1555	  which also takes priority if both are compiled in.
1556
1557config X86_64_ACPI_NUMA
1558	def_bool y
1559	prompt "ACPI NUMA detection"
1560	depends on X86_64 && NUMA && ACPI && PCI
1561	select ACPI_NUMA
1562	---help---
1563	  Enable ACPI SRAT based node topology detection.
1564
1565# Some NUMA nodes have memory ranges that span
1566# other nodes.  Even though a pfn is valid and
1567# between a node's start and end pfns, it may not
1568# reside on that node.  See memmap_init_zone()
1569# for details.
1570config NODES_SPAN_OTHER_NODES
1571	def_bool y
1572	depends on X86_64_ACPI_NUMA
1573
1574config NUMA_EMU
1575	bool "NUMA emulation"
1576	depends on NUMA
1577	---help---
1578	  Enable NUMA emulation. A flat machine will be split
1579	  into virtual nodes when booted with "numa=fake=N", where N is the
1580	  number of nodes. This is only useful for debugging.
1581
1582config NODES_SHIFT
1583	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1584	range 1 10
1585	default "10" if MAXSMP
1586	default "6" if X86_64
1587	default "3"
1588	depends on NEED_MULTIPLE_NODES
1589	---help---
1590	  Specify the maximum number of NUMA Nodes available on the target
1591	  system.  Increases memory reserved to accommodate various tables.
1592
1593config ARCH_HAVE_MEMORY_PRESENT
1594	def_bool y
1595	depends on X86_32 && DISCONTIGMEM
1596
1597config ARCH_FLATMEM_ENABLE
1598	def_bool y
1599	depends on X86_32 && !NUMA
1600
1601config ARCH_DISCONTIGMEM_ENABLE
1602	def_bool n
1603	depends on NUMA && X86_32
1604	depends on BROKEN
1605
1606config ARCH_SPARSEMEM_ENABLE
1607	def_bool y
1608	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1609	select SPARSEMEM_STATIC if X86_32
1610	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1611
1612config ARCH_SPARSEMEM_DEFAULT
1613	def_bool X86_64 || (NUMA && X86_32)
1614
1615config ARCH_SELECT_MEMORY_MODEL
1616	def_bool y
1617	depends on ARCH_SPARSEMEM_ENABLE
1618
1619config ARCH_MEMORY_PROBE
1620	bool "Enable sysfs memory/probe interface"
1621	depends on X86_64 && MEMORY_HOTPLUG
1622	help
1623	  This option enables a sysfs memory/probe interface for testing.
1624	  See Documentation/memory-hotplug.txt for more information.
1625	  If you are unsure how to answer this question, answer N.
1626
1627config ARCH_PROC_KCORE_TEXT
1628	def_bool y
1629	depends on X86_64 && PROC_KCORE
1630
1631config ILLEGAL_POINTER_VALUE
1632       hex
1633       default 0 if X86_32
1634       default 0xdead000000000000 if X86_64
1635
1636config X86_PMEM_LEGACY_DEVICE
1637	bool
1638
1639config X86_PMEM_LEGACY
1640	tristate "Support non-standard NVDIMMs and ADR protected memory"
1641	depends on PHYS_ADDR_T_64BIT
1642	depends on BLK_DEV
1643	select X86_PMEM_LEGACY_DEVICE
1644	select LIBNVDIMM
1645	help
1646	  Treat memory marked using the non-standard e820 type of 12 as used
1647	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1648	  The kernel will offer these regions to the 'pmem' driver so
1649	  they can be used for persistent storage.
1650
1651	  Say Y if unsure.
1652
1653config HIGHPTE
1654	bool "Allocate 3rd-level pagetables from highmem"
1655	depends on HIGHMEM
1656	---help---
1657	  The VM uses one page table entry for each page of physical memory.
1658	  For systems with a lot of RAM, this can be wasteful of precious
1659	  low memory.  Setting this option will put user-space page table
1660	  entries in high memory.
1661
1662config X86_CHECK_BIOS_CORRUPTION
1663	bool "Check for low memory corruption"
1664	---help---
1665	  Periodically check for memory corruption in low memory, which
1666	  is suspected to be caused by BIOS.  Even when enabled in the
1667	  configuration, it is disabled at runtime.  Enable it by
1668	  setting "memory_corruption_check=1" on the kernel command
1669	  line.  By default it scans the low 64k of memory every 60
1670	  seconds; see the memory_corruption_check_size and
1671	  memory_corruption_check_period parameters in
1672	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1673
1674	  When enabled with the default parameters, this option has
1675	  almost no overhead, as it reserves a relatively small amount
1676	  of memory and scans it infrequently.  It both detects corruption
1677	  and prevents it from affecting the running system.
1678
1679	  It is, however, intended as a diagnostic tool; if repeatable
1680	  BIOS-originated corruption always affects the same memory,
1681	  you can use memmap= to prevent the kernel from using that
1682	  memory.
1683
1684config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1685	bool "Set the default setting of memory_corruption_check"
1686	depends on X86_CHECK_BIOS_CORRUPTION
1687	default y
1688	---help---
1689	  Set whether the default state of memory_corruption_check is
1690	  on or off.
1691
1692config X86_RESERVE_LOW
1693	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1694	default 64
1695	range 4 640
1696	---help---
1697	  Specify the amount of low memory to reserve for the BIOS.
1698
1699	  The first page contains BIOS data structures that the kernel
1700	  must not use, so that page must always be reserved.
1701
1702	  By default we reserve the first 64K of physical RAM, as a
1703	  number of BIOSes are known to corrupt that memory range
1704	  during events such as suspend/resume or monitor cable
1705	  insertion, so it must not be used by the kernel.
1706
1707	  You can set this to 4 if you are absolutely sure that you
1708	  trust the BIOS to get all its memory reservations and usages
1709	  right.  If you know your BIOS have problems beyond the
1710	  default 64K area, you can set this to 640 to avoid using the
1711	  entire low memory range.
1712
1713	  If you have doubts about the BIOS (e.g. suspend/resume does
1714	  not work or there's kernel crashes after certain hardware
1715	  hotplug events) then you might want to enable
1716	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1717	  typical corruption patterns.
1718
1719	  Leave this to the default value of 64 if you are unsure.
1720
1721config MATH_EMULATION
1722	bool
1723	depends on MODIFY_LDT_SYSCALL
1724	prompt "Math emulation" if X86_32
1725	---help---
1726	  Linux can emulate a math coprocessor (used for floating point
1727	  operations) if you don't have one. 486DX and Pentium processors have
1728	  a math coprocessor built in, 486SX and 386 do not, unless you added
1729	  a 487DX or 387, respectively. (The messages during boot time can
1730	  give you some hints here ["man dmesg"].) Everyone needs either a
1731	  coprocessor or this emulation.
1732
1733	  If you don't have a math coprocessor, you need to say Y here; if you
1734	  say Y here even though you have a coprocessor, the coprocessor will
1735	  be used nevertheless. (This behavior can be changed with the kernel
1736	  command line option "no387", which comes handy if your coprocessor
1737	  is broken. Try "man bootparam" or see the documentation of your boot
1738	  loader (lilo or loadlin) about how to pass options to the kernel at
1739	  boot time.) This means that it is a good idea to say Y here if you
1740	  intend to use this kernel on different machines.
1741
1742	  More information about the internals of the Linux math coprocessor
1743	  emulation can be found in <file:arch/x86/math-emu/README>.
1744
1745	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1746	  kernel, it won't hurt.
1747
1748config MTRR
1749	def_bool y
1750	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1751	---help---
1752	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1753	  the Memory Type Range Registers (MTRRs) may be used to control
1754	  processor access to memory ranges. This is most useful if you have
1755	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1756	  allows bus write transfers to be combined into a larger transfer
1757	  before bursting over the PCI/AGP bus. This can increase performance
1758	  of image write operations 2.5 times or more. Saying Y here creates a
1759	  /proc/mtrr file which may be used to manipulate your processor's
1760	  MTRRs. Typically the X server should use this.
1761
1762	  This code has a reasonably generic interface so that similar
1763	  control registers on other processors can be easily supported
1764	  as well:
1765
1766	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1767	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1768	  these, the ARRs are used to emulate the MTRRs.
1769	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1770	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1771	  write-combining. All of these processors are supported by this code
1772	  and it makes sense to say Y here if you have one of them.
1773
1774	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1775	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1776	  can lead to all sorts of problems, so it's good to say Y here.
1777
1778	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1779	  just add about 9 KB to your kernel.
1780
1781	  See <file:Documentation/x86/mtrr.txt> for more information.
1782
1783config MTRR_SANITIZER
1784	def_bool y
1785	prompt "MTRR cleanup support"
1786	depends on MTRR
1787	---help---
1788	  Convert MTRR layout from continuous to discrete, so X drivers can
1789	  add writeback entries.
1790
1791	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1792	  The largest mtrr entry size for a continuous block can be set with
1793	  mtrr_chunk_size.
1794
1795	  If unsure, say Y.
1796
1797config MTRR_SANITIZER_ENABLE_DEFAULT
1798	int "MTRR cleanup enable value (0-1)"
1799	range 0 1
1800	default "0"
1801	depends on MTRR_SANITIZER
1802	---help---
1803	  Enable mtrr cleanup default value
1804
1805config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1806	int "MTRR cleanup spare reg num (0-7)"
1807	range 0 7
1808	default "1"
1809	depends on MTRR_SANITIZER
1810	---help---
1811	  mtrr cleanup spare entries default, it can be changed via
1812	  mtrr_spare_reg_nr=N on the kernel command line.
1813
1814config X86_PAT
1815	def_bool y
1816	prompt "x86 PAT support" if EXPERT
1817	depends on MTRR
1818	---help---
1819	  Use PAT attributes to setup page level cache control.
1820
1821	  PATs are the modern equivalents of MTRRs and are much more
1822	  flexible than MTRRs.
1823
1824	  Say N here if you see bootup problems (boot crash, boot hang,
1825	  spontaneous reboots) or a non-working video driver.
1826
1827	  If unsure, say Y.
1828
1829config ARCH_USES_PG_UNCACHED
1830	def_bool y
1831	depends on X86_PAT
1832
1833config ARCH_RANDOM
1834	def_bool y
1835	prompt "x86 architectural random number generator" if EXPERT
1836	---help---
1837	  Enable the x86 architectural RDRAND instruction
1838	  (Intel Bull Mountain technology) to generate random numbers.
1839	  If supported, this is a high bandwidth, cryptographically
1840	  secure hardware random number generator.
1841
1842config X86_SMAP
1843	def_bool y
1844	prompt "Supervisor Mode Access Prevention" if EXPERT
1845	---help---
1846	  Supervisor Mode Access Prevention (SMAP) is a security
1847	  feature in newer Intel processors.  There is a small
1848	  performance cost if this enabled and turned on; there is
1849	  also a small increase in the kernel size if this is enabled.
1850
1851	  If unsure, say Y.
1852
1853config X86_INTEL_UMIP
1854	def_bool y
1855	depends on CPU_SUP_INTEL
1856	prompt "Intel User Mode Instruction Prevention" if EXPERT
1857	---help---
1858	  The User Mode Instruction Prevention (UMIP) is a security
1859	  feature in newer Intel processors. If enabled, a general
1860	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1861	  or STR instructions are executed in user mode. These instructions
1862	  unnecessarily expose information about the hardware state.
1863
1864	  The vast majority of applications do not use these instructions.
1865	  For the very few that do, software emulation is provided in
1866	  specific cases in protected and virtual-8086 modes. Emulated
1867	  results are dummy.
1868
1869config X86_INTEL_MPX
1870	prompt "Intel MPX (Memory Protection Extensions)"
1871	def_bool n
1872	# Note: only available in 64-bit mode due to VMA flags shortage
1873	depends on CPU_SUP_INTEL && X86_64
1874	select ARCH_USES_HIGH_VMA_FLAGS
1875	---help---
1876	  MPX provides hardware features that can be used in
1877	  conjunction with compiler-instrumented code to check
1878	  memory references.  It is designed to detect buffer
1879	  overflow or underflow bugs.
1880
1881	  This option enables running applications which are
1882	  instrumented or otherwise use MPX.  It does not use MPX
1883	  itself inside the kernel or to protect the kernel
1884	  against bad memory references.
1885
1886	  Enabling this option will make the kernel larger:
1887	  ~8k of kernel text and 36 bytes of data on a 64-bit
1888	  defconfig.  It adds a long to the 'mm_struct' which
1889	  will increase the kernel memory overhead of each
1890	  process and adds some branches to paths used during
1891	  exec() and munmap().
1892
1893	  For details, see Documentation/x86/intel_mpx.txt
1894
1895	  If unsure, say N.
1896
1897config X86_INTEL_MEMORY_PROTECTION_KEYS
1898	prompt "Intel Memory Protection Keys"
1899	def_bool y
1900	# Note: only available in 64-bit mode
1901	depends on CPU_SUP_INTEL && X86_64
1902	select ARCH_USES_HIGH_VMA_FLAGS
1903	select ARCH_HAS_PKEYS
1904	---help---
1905	  Memory Protection Keys provides a mechanism for enforcing
1906	  page-based protections, but without requiring modification of the
1907	  page tables when an application changes protection domains.
1908
1909	  For details, see Documentation/x86/protection-keys.txt
1910
1911	  If unsure, say y.
1912
1913config EFI
1914	bool "EFI runtime service support"
1915	depends on ACPI
1916	select UCS2_STRING
1917	select EFI_RUNTIME_WRAPPERS
1918	---help---
1919	  This enables the kernel to use EFI runtime services that are
1920	  available (such as the EFI variable services).
1921
1922	  This option is only useful on systems that have EFI firmware.
1923	  In addition, you should use the latest ELILO loader available
1924	  at <http://elilo.sourceforge.net> in order to take advantage
1925	  of EFI runtime services. However, even with this option, the
1926	  resultant kernel should continue to boot on existing non-EFI
1927	  platforms.
1928
1929config EFI_STUB
1930       bool "EFI stub support"
1931       depends on EFI && !X86_USE_3DNOW
1932       select RELOCATABLE
1933       ---help---
1934          This kernel feature allows a bzImage to be loaded directly
1935	  by EFI firmware without the use of a bootloader.
1936
1937	  See Documentation/efi-stub.txt for more information.
1938
1939config EFI_MIXED
1940	bool "EFI mixed-mode support"
1941	depends on EFI_STUB && X86_64
1942	---help---
1943	   Enabling this feature allows a 64-bit kernel to be booted
1944	   on a 32-bit firmware, provided that your CPU supports 64-bit
1945	   mode.
1946
1947	   Note that it is not possible to boot a mixed-mode enabled
1948	   kernel via the EFI boot stub - a bootloader that supports
1949	   the EFI handover protocol must be used.
1950
1951	   If unsure, say N.
1952
1953config SECCOMP
1954	def_bool y
1955	prompt "Enable seccomp to safely compute untrusted bytecode"
1956	---help---
1957	  This kernel feature is useful for number crunching applications
1958	  that may need to compute untrusted bytecode during their
1959	  execution. By using pipes or other transports made available to
1960	  the process as file descriptors supporting the read/write
1961	  syscalls, it's possible to isolate those applications in
1962	  their own address space using seccomp. Once seccomp is
1963	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1964	  and the task is only allowed to execute a few safe syscalls
1965	  defined by each seccomp mode.
1966
1967	  If unsure, say Y. Only embedded should say N here.
1968
1969source "kernel/Kconfig.hz"
1970
1971config KEXEC
1972	bool "kexec system call"
1973	select KEXEC_CORE
1974	---help---
1975	  kexec is a system call that implements the ability to shutdown your
1976	  current kernel, and to start another kernel.  It is like a reboot
1977	  but it is independent of the system firmware.   And like a reboot
1978	  you can start any kernel with it, not just Linux.
1979
1980	  The name comes from the similarity to the exec system call.
1981
1982	  It is an ongoing process to be certain the hardware in a machine
1983	  is properly shutdown, so do not be surprised if this code does not
1984	  initially work for you.  As of this writing the exact hardware
1985	  interface is strongly in flux, so no good recommendation can be
1986	  made.
1987
1988config KEXEC_FILE
1989	bool "kexec file based system call"
1990	select KEXEC_CORE
1991	select BUILD_BIN2C
1992	depends on X86_64
1993	depends on CRYPTO=y
1994	depends on CRYPTO_SHA256=y
1995	---help---
1996	  This is new version of kexec system call. This system call is
1997	  file based and takes file descriptors as system call argument
1998	  for kernel and initramfs as opposed to list of segments as
1999	  accepted by previous system call.
2000
2001config ARCH_HAS_KEXEC_PURGATORY
2002	def_bool KEXEC_FILE
2003
2004config KEXEC_VERIFY_SIG
2005	bool "Verify kernel signature during kexec_file_load() syscall"
2006	depends on KEXEC_FILE
2007	---help---
2008	  This option makes kernel signature verification mandatory for
2009	  the kexec_file_load() syscall.
2010
2011	  In addition to that option, you need to enable signature
2012	  verification for the corresponding kernel image type being
2013	  loaded in order for this to work.
2014
2015config KEXEC_BZIMAGE_VERIFY_SIG
2016	bool "Enable bzImage signature verification support"
2017	depends on KEXEC_VERIFY_SIG
2018	depends on SIGNED_PE_FILE_VERIFICATION
2019	select SYSTEM_TRUSTED_KEYRING
2020	---help---
2021	  Enable bzImage signature verification support.
2022
2023config CRASH_DUMP
2024	bool "kernel crash dumps"
2025	depends on X86_64 || (X86_32 && HIGHMEM)
2026	---help---
2027	  Generate crash dump after being started by kexec.
2028	  This should be normally only set in special crash dump kernels
2029	  which are loaded in the main kernel with kexec-tools into
2030	  a specially reserved region and then later executed after
2031	  a crash by kdump/kexec. The crash dump kernel must be compiled
2032	  to a memory address not used by the main kernel or BIOS using
2033	  PHYSICAL_START, or it must be built as a relocatable image
2034	  (CONFIG_RELOCATABLE=y).
2035	  For more details see Documentation/kdump/kdump.txt
2036
2037config KEXEC_JUMP
2038	bool "kexec jump"
2039	depends on KEXEC && HIBERNATION
2040	---help---
2041	  Jump between original kernel and kexeced kernel and invoke
2042	  code in physical address mode via KEXEC
2043
2044config PHYSICAL_START
2045	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2046	default "0x1000000"
2047	---help---
2048	  This gives the physical address where the kernel is loaded.
2049
2050	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2051	  bzImage will decompress itself to above physical address and
2052	  run from there. Otherwise, bzImage will run from the address where
2053	  it has been loaded by the boot loader and will ignore above physical
2054	  address.
2055
2056	  In normal kdump cases one does not have to set/change this option
2057	  as now bzImage can be compiled as a completely relocatable image
2058	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2059	  address. This option is mainly useful for the folks who don't want
2060	  to use a bzImage for capturing the crash dump and want to use a
2061	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2062	  to be specifically compiled to run from a specific memory area
2063	  (normally a reserved region) and this option comes handy.
2064
2065	  So if you are using bzImage for capturing the crash dump,
2066	  leave the value here unchanged to 0x1000000 and set
2067	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2068	  for capturing the crash dump change this value to start of
2069	  the reserved region.  In other words, it can be set based on
2070	  the "X" value as specified in the "crashkernel=YM@XM"
2071	  command line boot parameter passed to the panic-ed
2072	  kernel. Please take a look at Documentation/kdump/kdump.txt
2073	  for more details about crash dumps.
2074
2075	  Usage of bzImage for capturing the crash dump is recommended as
2076	  one does not have to build two kernels. Same kernel can be used
2077	  as production kernel and capture kernel. Above option should have
2078	  gone away after relocatable bzImage support is introduced. But it
2079	  is present because there are users out there who continue to use
2080	  vmlinux for dump capture. This option should go away down the
2081	  line.
2082
2083	  Don't change this unless you know what you are doing.
2084
2085config RELOCATABLE
2086	bool "Build a relocatable kernel"
2087	default y
2088	---help---
2089	  This builds a kernel image that retains relocation information
2090	  so it can be loaded someplace besides the default 1MB.
2091	  The relocations tend to make the kernel binary about 10% larger,
2092	  but are discarded at runtime.
2093
2094	  One use is for the kexec on panic case where the recovery kernel
2095	  must live at a different physical address than the primary
2096	  kernel.
2097
2098	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2099	  it has been loaded at and the compile time physical address
2100	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2101
2102config RANDOMIZE_BASE
2103	bool "Randomize the address of the kernel image (KASLR)"
2104	depends on RELOCATABLE
2105	default y
2106	---help---
2107	  In support of Kernel Address Space Layout Randomization (KASLR),
2108	  this randomizes the physical address at which the kernel image
2109	  is decompressed and the virtual address where the kernel
2110	  image is mapped, as a security feature that deters exploit
2111	  attempts relying on knowledge of the location of kernel
2112	  code internals.
2113
2114	  On 64-bit, the kernel physical and virtual addresses are
2115	  randomized separately. The physical address will be anywhere
2116	  between 16MB and the top of physical memory (up to 64TB). The
2117	  virtual address will be randomized from 16MB up to 1GB (9 bits
2118	  of entropy). Note that this also reduces the memory space
2119	  available to kernel modules from 1.5GB to 1GB.
2120
2121	  On 32-bit, the kernel physical and virtual addresses are
2122	  randomized together. They will be randomized from 16MB up to
2123	  512MB (8 bits of entropy).
2124
2125	  Entropy is generated using the RDRAND instruction if it is
2126	  supported. If RDTSC is supported, its value is mixed into
2127	  the entropy pool as well. If neither RDRAND nor RDTSC are
2128	  supported, then entropy is read from the i8254 timer. The
2129	  usable entropy is limited by the kernel being built using
2130	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2131	  minimum of 2MB. As a result, only 10 bits of entropy are
2132	  theoretically possible, but the implementations are further
2133	  limited due to memory layouts.
2134
2135	  If unsure, say Y.
2136
2137# Relocation on x86 needs some additional build support
2138config X86_NEED_RELOCS
2139	def_bool y
2140	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2141
2142config PHYSICAL_ALIGN
2143	hex "Alignment value to which kernel should be aligned"
2144	default "0x200000"
2145	range 0x2000 0x1000000 if X86_32
2146	range 0x200000 0x1000000 if X86_64
2147	---help---
2148	  This value puts the alignment restrictions on physical address
2149	  where kernel is loaded and run from. Kernel is compiled for an
2150	  address which meets above alignment restriction.
2151
2152	  If bootloader loads the kernel at a non-aligned address and
2153	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2154	  address aligned to above value and run from there.
2155
2156	  If bootloader loads the kernel at a non-aligned address and
2157	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2158	  load address and decompress itself to the address it has been
2159	  compiled for and run from there. The address for which kernel is
2160	  compiled already meets above alignment restrictions. Hence the
2161	  end result is that kernel runs from a physical address meeting
2162	  above alignment restrictions.
2163
2164	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2165	  this value must be a multiple of 0x200000.
2166
2167	  Don't change this unless you know what you are doing.
2168
2169config DYNAMIC_MEMORY_LAYOUT
2170	bool
2171	---help---
2172	  This option makes base addresses of vmalloc and vmemmap as well as
2173	  __PAGE_OFFSET movable during boot.
2174
2175config RANDOMIZE_MEMORY
2176	bool "Randomize the kernel memory sections"
2177	depends on X86_64
2178	depends on RANDOMIZE_BASE
2179	select DYNAMIC_MEMORY_LAYOUT
2180	default RANDOMIZE_BASE
2181	---help---
2182	   Randomizes the base virtual address of kernel memory sections
2183	   (physical memory mapping, vmalloc & vmemmap). This security feature
2184	   makes exploits relying on predictable memory locations less reliable.
2185
2186	   The order of allocations remains unchanged. Entropy is generated in
2187	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2188	   configuration have in average 30,000 different possible virtual
2189	   addresses for each memory section.
2190
2191	   If unsure, say Y.
2192
2193config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2194	hex "Physical memory mapping padding" if EXPERT
2195	depends on RANDOMIZE_MEMORY
2196	default "0xa" if MEMORY_HOTPLUG
2197	default "0x0"
2198	range 0x1 0x40 if MEMORY_HOTPLUG
2199	range 0x0 0x40
2200	---help---
2201	   Define the padding in terabytes added to the existing physical
2202	   memory size during kernel memory randomization. It is useful
2203	   for memory hotplug support but reduces the entropy available for
2204	   address randomization.
2205
2206	   If unsure, leave at the default value.
2207
2208config HOTPLUG_CPU
2209	def_bool y
2210	depends on SMP
2211
2212config BOOTPARAM_HOTPLUG_CPU0
2213	bool "Set default setting of cpu0_hotpluggable"
2214	depends on HOTPLUG_CPU
2215	---help---
2216	  Set whether default state of cpu0_hotpluggable is on or off.
2217
2218	  Say Y here to enable CPU0 hotplug by default. If this switch
2219	  is turned on, there is no need to give cpu0_hotplug kernel
2220	  parameter and the CPU0 hotplug feature is enabled by default.
2221
2222	  Please note: there are two known CPU0 dependencies if you want
2223	  to enable the CPU0 hotplug feature either by this switch or by
2224	  cpu0_hotplug kernel parameter.
2225
2226	  First, resume from hibernate or suspend always starts from CPU0.
2227	  So hibernate and suspend are prevented if CPU0 is offline.
2228
2229	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2230	  offline if any interrupt can not migrate out of CPU0. There may
2231	  be other CPU0 dependencies.
2232
2233	  Please make sure the dependencies are under your control before
2234	  you enable this feature.
2235
2236	  Say N if you don't want to enable CPU0 hotplug feature by default.
2237	  You still can enable the CPU0 hotplug feature at boot by kernel
2238	  parameter cpu0_hotplug.
2239
2240config DEBUG_HOTPLUG_CPU0
2241	def_bool n
2242	prompt "Debug CPU0 hotplug"
2243	depends on HOTPLUG_CPU
2244	---help---
2245	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2246	  soon as possible and boots up userspace with CPU0 offlined. User
2247	  can online CPU0 back after boot time.
2248
2249	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2250	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2251	  compilation or giving cpu0_hotplug kernel parameter at boot.
2252
2253	  If unsure, say N.
2254
2255config COMPAT_VDSO
2256	def_bool n
2257	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2258	depends on COMPAT_32
2259	---help---
2260	  Certain buggy versions of glibc will crash if they are
2261	  presented with a 32-bit vDSO that is not mapped at the address
2262	  indicated in its segment table.
2263
2264	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2265	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2266	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2267	  the only released version with the bug, but OpenSUSE 9
2268	  contains a buggy "glibc 2.3.2".
2269
2270	  The symptom of the bug is that everything crashes on startup, saying:
2271	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2272
2273	  Saying Y here changes the default value of the vdso32 boot
2274	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2275	  This works around the glibc bug but hurts performance.
2276
2277	  If unsure, say N: if you are compiling your own kernel, you
2278	  are unlikely to be using a buggy version of glibc.
2279
2280choice
2281	prompt "vsyscall table for legacy applications"
2282	depends on X86_64
2283	default LEGACY_VSYSCALL_EMULATE
2284	help
2285	  Legacy user code that does not know how to find the vDSO expects
2286	  to be able to issue three syscalls by calling fixed addresses in
2287	  kernel space. Since this location is not randomized with ASLR,
2288	  it can be used to assist security vulnerability exploitation.
2289
2290	  This setting can be changed at boot time via the kernel command
2291	  line parameter vsyscall=[emulate|none].
2292
2293	  On a system with recent enough glibc (2.14 or newer) and no
2294	  static binaries, you can say None without a performance penalty
2295	  to improve security.
2296
2297	  If unsure, select "Emulate".
2298
2299	config LEGACY_VSYSCALL_EMULATE
2300		bool "Emulate"
2301		help
2302		  The kernel traps and emulates calls into the fixed
2303		  vsyscall address mapping. This makes the mapping
2304		  non-executable, but it still contains known contents,
2305		  which could be used in certain rare security vulnerability
2306		  exploits. This configuration is recommended when userspace
2307		  still uses the vsyscall area.
2308
2309	config LEGACY_VSYSCALL_NONE
2310		bool "None"
2311		help
2312		  There will be no vsyscall mapping at all. This will
2313		  eliminate any risk of ASLR bypass due to the vsyscall
2314		  fixed address mapping. Attempts to use the vsyscalls
2315		  will be reported to dmesg, so that either old or
2316		  malicious userspace programs can be identified.
2317
2318endchoice
2319
2320config CMDLINE_BOOL
2321	bool "Built-in kernel command line"
2322	---help---
2323	  Allow for specifying boot arguments to the kernel at
2324	  build time.  On some systems (e.g. embedded ones), it is
2325	  necessary or convenient to provide some or all of the
2326	  kernel boot arguments with the kernel itself (that is,
2327	  to not rely on the boot loader to provide them.)
2328
2329	  To compile command line arguments into the kernel,
2330	  set this option to 'Y', then fill in the
2331	  boot arguments in CONFIG_CMDLINE.
2332
2333	  Systems with fully functional boot loaders (i.e. non-embedded)
2334	  should leave this option set to 'N'.
2335
2336config CMDLINE
2337	string "Built-in kernel command string"
2338	depends on CMDLINE_BOOL
2339	default ""
2340	---help---
2341	  Enter arguments here that should be compiled into the kernel
2342	  image and used at boot time.  If the boot loader provides a
2343	  command line at boot time, it is appended to this string to
2344	  form the full kernel command line, when the system boots.
2345
2346	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2347	  change this behavior.
2348
2349	  In most cases, the command line (whether built-in or provided
2350	  by the boot loader) should specify the device for the root
2351	  file system.
2352
2353config CMDLINE_OVERRIDE
2354	bool "Built-in command line overrides boot loader arguments"
2355	depends on CMDLINE_BOOL
2356	---help---
2357	  Set this option to 'Y' to have the kernel ignore the boot loader
2358	  command line, and use ONLY the built-in command line.
2359
2360	  This is used to work around broken boot loaders.  This should
2361	  be set to 'N' under normal conditions.
2362
2363config MODIFY_LDT_SYSCALL
2364	bool "Enable the LDT (local descriptor table)" if EXPERT
2365	default y
2366	---help---
2367	  Linux can allow user programs to install a per-process x86
2368	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2369	  call.  This is required to run 16-bit or segmented code such as
2370	  DOSEMU or some Wine programs.  It is also used by some very old
2371	  threading libraries.
2372
2373	  Enabling this feature adds a small amount of overhead to
2374	  context switches and increases the low-level kernel attack
2375	  surface.  Disabling it removes the modify_ldt(2) system call.
2376
2377	  Saying 'N' here may make sense for embedded or server kernels.
2378
2379source "kernel/livepatch/Kconfig"
2380
2381endmenu
2382
2383config ARCH_HAS_ADD_PAGES
2384	def_bool y
2385	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2386
2387config ARCH_ENABLE_MEMORY_HOTPLUG
2388	def_bool y
2389	depends on X86_64 || (X86_32 && HIGHMEM)
2390
2391config ARCH_ENABLE_MEMORY_HOTREMOVE
2392	def_bool y
2393	depends on MEMORY_HOTPLUG
2394
2395config USE_PERCPU_NUMA_NODE_ID
2396	def_bool y
2397	depends on NUMA
2398
2399config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2400	def_bool y
2401	depends on X86_64 || X86_PAE
2402
2403config ARCH_ENABLE_HUGEPAGE_MIGRATION
2404	def_bool y
2405	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2406
2407config ARCH_ENABLE_THP_MIGRATION
2408	def_bool y
2409	depends on X86_64 && TRANSPARENT_HUGEPAGE
2410
2411menu "Power management and ACPI options"
2412
2413config ARCH_HIBERNATION_HEADER
2414	def_bool y
2415	depends on HIBERNATION
2416
2417source "kernel/power/Kconfig"
2418
2419source "drivers/acpi/Kconfig"
2420
2421source "drivers/sfi/Kconfig"
2422
2423config X86_APM_BOOT
2424	def_bool y
2425	depends on APM
2426
2427menuconfig APM
2428	tristate "APM (Advanced Power Management) BIOS support"
2429	depends on X86_32 && PM_SLEEP
2430	---help---
2431	  APM is a BIOS specification for saving power using several different
2432	  techniques. This is mostly useful for battery powered laptops with
2433	  APM compliant BIOSes. If you say Y here, the system time will be
2434	  reset after a RESUME operation, the /proc/apm device will provide
2435	  battery status information, and user-space programs will receive
2436	  notification of APM "events" (e.g. battery status change).
2437
2438	  If you select "Y" here, you can disable actual use of the APM
2439	  BIOS by passing the "apm=off" option to the kernel at boot time.
2440
2441	  Note that the APM support is almost completely disabled for
2442	  machines with more than one CPU.
2443
2444	  In order to use APM, you will need supporting software. For location
2445	  and more information, read <file:Documentation/power/apm-acpi.txt>
2446	  and the Battery Powered Linux mini-HOWTO, available from
2447	  <http://www.tldp.org/docs.html#howto>.
2448
2449	  This driver does not spin down disk drives (see the hdparm(8)
2450	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2451	  VESA-compliant "green" monitors.
2452
2453	  This driver does not support the TI 4000M TravelMate and the ACER
2454	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2455	  desktop machines also don't have compliant BIOSes, and this driver
2456	  may cause those machines to panic during the boot phase.
2457
2458	  Generally, if you don't have a battery in your machine, there isn't
2459	  much point in using this driver and you should say N. If you get
2460	  random kernel OOPSes or reboots that don't seem to be related to
2461	  anything, try disabling/enabling this option (or disabling/enabling
2462	  APM in your BIOS).
2463
2464	  Some other things you should try when experiencing seemingly random,
2465	  "weird" problems:
2466
2467	  1) make sure that you have enough swap space and that it is
2468	  enabled.
2469	  2) pass the "no-hlt" option to the kernel
2470	  3) switch on floating point emulation in the kernel and pass
2471	  the "no387" option to the kernel
2472	  4) pass the "floppy=nodma" option to the kernel
2473	  5) pass the "mem=4M" option to the kernel (thereby disabling
2474	  all but the first 4 MB of RAM)
2475	  6) make sure that the CPU is not over clocked.
2476	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2477	  8) disable the cache from your BIOS settings
2478	  9) install a fan for the video card or exchange video RAM
2479	  10) install a better fan for the CPU
2480	  11) exchange RAM chips
2481	  12) exchange the motherboard.
2482
2483	  To compile this driver as a module, choose M here: the
2484	  module will be called apm.
2485
2486if APM
2487
2488config APM_IGNORE_USER_SUSPEND
2489	bool "Ignore USER SUSPEND"
2490	---help---
2491	  This option will ignore USER SUSPEND requests. On machines with a
2492	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2493	  series notebooks, it is necessary to say Y because of a BIOS bug.
2494
2495config APM_DO_ENABLE
2496	bool "Enable PM at boot time"
2497	---help---
2498	  Enable APM features at boot time. From page 36 of the APM BIOS
2499	  specification: "When disabled, the APM BIOS does not automatically
2500	  power manage devices, enter the Standby State, enter the Suspend
2501	  State, or take power saving steps in response to CPU Idle calls."
2502	  This driver will make CPU Idle calls when Linux is idle (unless this
2503	  feature is turned off -- see "Do CPU IDLE calls", below). This
2504	  should always save battery power, but more complicated APM features
2505	  will be dependent on your BIOS implementation. You may need to turn
2506	  this option off if your computer hangs at boot time when using APM
2507	  support, or if it beeps continuously instead of suspending. Turn
2508	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2509	  T400CDT. This is off by default since most machines do fine without
2510	  this feature.
2511
2512config APM_CPU_IDLE
2513	depends on CPU_IDLE
2514	bool "Make CPU Idle calls when idle"
2515	---help---
2516	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2517	  On some machines, this can activate improved power savings, such as
2518	  a slowed CPU clock rate, when the machine is idle. These idle calls
2519	  are made after the idle loop has run for some length of time (e.g.,
2520	  333 mS). On some machines, this will cause a hang at boot time or
2521	  whenever the CPU becomes idle. (On machines with more than one CPU,
2522	  this option does nothing.)
2523
2524config APM_DISPLAY_BLANK
2525	bool "Enable console blanking using APM"
2526	---help---
2527	  Enable console blanking using the APM. Some laptops can use this to
2528	  turn off the LCD backlight when the screen blanker of the Linux
2529	  virtual console blanks the screen. Note that this is only used by
2530	  the virtual console screen blanker, and won't turn off the backlight
2531	  when using the X Window system. This also doesn't have anything to
2532	  do with your VESA-compliant power-saving monitor. Further, this
2533	  option doesn't work for all laptops -- it might not turn off your
2534	  backlight at all, or it might print a lot of errors to the console,
2535	  especially if you are using gpm.
2536
2537config APM_ALLOW_INTS
2538	bool "Allow interrupts during APM BIOS calls"
2539	---help---
2540	  Normally we disable external interrupts while we are making calls to
2541	  the APM BIOS as a measure to lessen the effects of a badly behaving
2542	  BIOS implementation.  The BIOS should reenable interrupts if it
2543	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2544	  many of the newer IBM Thinkpads.  If you experience hangs when you
2545	  suspend, try setting this to Y.  Otherwise, say N.
2546
2547endif # APM
2548
2549source "drivers/cpufreq/Kconfig"
2550
2551source "drivers/cpuidle/Kconfig"
2552
2553source "drivers/idle/Kconfig"
2554
2555endmenu
2556
2557
2558menu "Bus options (PCI etc.)"
2559
2560choice
2561	prompt "PCI access mode"
2562	depends on X86_32 && PCI
2563	default PCI_GOANY
2564	---help---
2565	  On PCI systems, the BIOS can be used to detect the PCI devices and
2566	  determine their configuration. However, some old PCI motherboards
2567	  have BIOS bugs and may crash if this is done. Also, some embedded
2568	  PCI-based systems don't have any BIOS at all. Linux can also try to
2569	  detect the PCI hardware directly without using the BIOS.
2570
2571	  With this option, you can specify how Linux should detect the
2572	  PCI devices. If you choose "BIOS", the BIOS will be used,
2573	  if you choose "Direct", the BIOS won't be used, and if you
2574	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2575	  If you choose "Any", the kernel will try MMCONFIG, then the
2576	  direct access method and falls back to the BIOS if that doesn't
2577	  work. If unsure, go with the default, which is "Any".
2578
2579config PCI_GOBIOS
2580	bool "BIOS"
2581
2582config PCI_GOMMCONFIG
2583	bool "MMConfig"
2584
2585config PCI_GODIRECT
2586	bool "Direct"
2587
2588config PCI_GOOLPC
2589	bool "OLPC XO-1"
2590	depends on OLPC
2591
2592config PCI_GOANY
2593	bool "Any"
2594
2595endchoice
2596
2597config PCI_BIOS
2598	def_bool y
2599	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2600
2601# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2602config PCI_DIRECT
2603	def_bool y
2604	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2605
2606config PCI_MMCONFIG
2607	bool "Support mmconfig PCI config space access" if X86_64
2608	default y
2609	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2610	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2611
2612config PCI_OLPC
2613	def_bool y
2614	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2615
2616config PCI_XEN
2617	def_bool y
2618	depends on PCI && XEN
2619	select SWIOTLB_XEN
2620
2621config MMCONF_FAM10H
2622	def_bool y
2623	depends on X86_64 && PCI_MMCONFIG && ACPI
2624
2625config PCI_CNB20LE_QUIRK
2626	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2627	depends on PCI
2628	help
2629	  Read the PCI windows out of the CNB20LE host bridge. This allows
2630	  PCI hotplug to work on systems with the CNB20LE chipset which do
2631	  not have ACPI.
2632
2633	  There's no public spec for this chipset, and this functionality
2634	  is known to be incomplete.
2635
2636	  You should say N unless you know you need this.
2637
2638config ISA_BUS
2639	bool "ISA bus support on modern systems" if EXPERT
2640	help
2641	  Expose ISA bus device drivers and options available for selection and
2642	  configuration. Enable this option if your target machine has an ISA
2643	  bus. ISA is an older system, displaced by PCI and newer bus
2644	  architectures -- if your target machine is modern, it probably does
2645	  not have an ISA bus.
2646
2647	  If unsure, say N.
2648
2649# x86_64 have no ISA slots, but can have ISA-style DMA.
2650config ISA_DMA_API
2651	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2652	default y
2653	help
2654	  Enables ISA-style DMA support for devices requiring such controllers.
2655	  If unsure, say Y.
2656
2657if X86_32
2658
2659config ISA
2660	bool "ISA support"
2661	---help---
2662	  Find out whether you have ISA slots on your motherboard.  ISA is the
2663	  name of a bus system, i.e. the way the CPU talks to the other stuff
2664	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2665	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2666	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2667
2668config SCx200
2669	tristate "NatSemi SCx200 support"
2670	---help---
2671	  This provides basic support for National Semiconductor's
2672	  (now AMD's) Geode processors.  The driver probes for the
2673	  PCI-IDs of several on-chip devices, so its a good dependency
2674	  for other scx200_* drivers.
2675
2676	  If compiled as a module, the driver is named scx200.
2677
2678config SCx200HR_TIMER
2679	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2680	depends on SCx200
2681	default y
2682	---help---
2683	  This driver provides a clocksource built upon the on-chip
2684	  27MHz high-resolution timer.  Its also a workaround for
2685	  NSC Geode SC-1100's buggy TSC, which loses time when the
2686	  processor goes idle (as is done by the scheduler).  The
2687	  other workaround is idle=poll boot option.
2688
2689config OLPC
2690	bool "One Laptop Per Child support"
2691	depends on !X86_PAE
2692	select GPIOLIB
2693	select OF
2694	select OF_PROMTREE
2695	select IRQ_DOMAIN
2696	---help---
2697	  Add support for detecting the unique features of the OLPC
2698	  XO hardware.
2699
2700config OLPC_XO1_PM
2701	bool "OLPC XO-1 Power Management"
2702	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2703	---help---
2704	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2705
2706config OLPC_XO1_RTC
2707	bool "OLPC XO-1 Real Time Clock"
2708	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2709	---help---
2710	  Add support for the XO-1 real time clock, which can be used as a
2711	  programmable wakeup source.
2712
2713config OLPC_XO1_SCI
2714	bool "OLPC XO-1 SCI extras"
2715	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2716	depends on INPUT=y
2717	select POWER_SUPPLY
2718	---help---
2719	  Add support for SCI-based features of the OLPC XO-1 laptop:
2720	   - EC-driven system wakeups
2721	   - Power button
2722	   - Ebook switch
2723	   - Lid switch
2724	   - AC adapter status updates
2725	   - Battery status updates
2726
2727config OLPC_XO15_SCI
2728	bool "OLPC XO-1.5 SCI extras"
2729	depends on OLPC && ACPI
2730	select POWER_SUPPLY
2731	---help---
2732	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2733	   - EC-driven system wakeups
2734	   - AC adapter status updates
2735	   - Battery status updates
2736
2737config ALIX
2738	bool "PCEngines ALIX System Support (LED setup)"
2739	select GPIOLIB
2740	---help---
2741	  This option enables system support for the PCEngines ALIX.
2742	  At present this just sets up LEDs for GPIO control on
2743	  ALIX2/3/6 boards.  However, other system specific setup should
2744	  get added here.
2745
2746	  Note: You must still enable the drivers for GPIO and LED support
2747	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2748
2749	  Note: You have to set alix.force=1 for boards with Award BIOS.
2750
2751config NET5501
2752	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2753	select GPIOLIB
2754	---help---
2755	  This option enables system support for the Soekris Engineering net5501.
2756
2757config GEOS
2758	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2759	select GPIOLIB
2760	depends on DMI
2761	---help---
2762	  This option enables system support for the Traverse Technologies GEOS.
2763
2764config TS5500
2765	bool "Technologic Systems TS-5500 platform support"
2766	depends on MELAN
2767	select CHECK_SIGNATURE
2768	select NEW_LEDS
2769	select LEDS_CLASS
2770	---help---
2771	  This option enables system support for the Technologic Systems TS-5500.
2772
2773endif # X86_32
2774
2775config AMD_NB
2776	def_bool y
2777	depends on CPU_SUP_AMD && PCI
2778
2779config X86_SYSFB
2780	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2781	help
2782	  Firmwares often provide initial graphics framebuffers so the BIOS,
2783	  bootloader or kernel can show basic video-output during boot for
2784	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2785	  Extensions and EFI-framebuffers for this, which are mostly limited
2786	  to x86.
2787	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2788	  framebuffers so the new generic system-framebuffer drivers can be
2789	  used on x86. If the framebuffer is not compatible with the generic
2790	  modes, it is advertised as fallback platform framebuffer so legacy
2791	  drivers like efifb, vesafb and uvesafb can pick it up.
2792	  If this option is not selected, all system framebuffers are always
2793	  marked as fallback platform framebuffers as usual.
2794
2795	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2796	  not be able to pick up generic system framebuffers if this option
2797	  is selected. You are highly encouraged to enable simplefb as
2798	  replacement if you select this option. simplefb can correctly deal
2799	  with generic system framebuffers. But you should still keep vesafb
2800	  and others enabled as fallback if a system framebuffer is
2801	  incompatible with simplefb.
2802
2803	  If unsure, say Y.
2804
2805endmenu
2806
2807
2808menu "Binary Emulations"
2809
2810config IA32_EMULATION
2811	bool "IA32 Emulation"
2812	depends on X86_64
2813	select ARCH_WANT_OLD_COMPAT_IPC
2814	select BINFMT_ELF
2815	select COMPAT_BINFMT_ELF
2816	select COMPAT_OLD_SIGACTION
2817	---help---
2818	  Include code to run legacy 32-bit programs under a
2819	  64-bit kernel. You should likely turn this on, unless you're
2820	  100% sure that you don't have any 32-bit programs left.
2821
2822config IA32_AOUT
2823	tristate "IA32 a.out support"
2824	depends on IA32_EMULATION
2825	depends on BROKEN
2826	---help---
2827	  Support old a.out binaries in the 32bit emulation.
2828
2829config X86_X32
2830	bool "x32 ABI for 64-bit mode"
2831	depends on X86_64
2832	---help---
2833	  Include code to run binaries for the x32 native 32-bit ABI
2834	  for 64-bit processors.  An x32 process gets access to the
2835	  full 64-bit register file and wide data path while leaving
2836	  pointers at 32 bits for smaller memory footprint.
2837
2838	  You will need a recent binutils (2.22 or later) with
2839	  elf32_x86_64 support enabled to compile a kernel with this
2840	  option set.
2841
2842config COMPAT_32
2843	def_bool y
2844	depends on IA32_EMULATION || X86_32
2845	select HAVE_UID16
2846	select OLD_SIGSUSPEND3
2847
2848config COMPAT
2849	def_bool y
2850	depends on IA32_EMULATION || X86_X32
2851
2852if COMPAT
2853config COMPAT_FOR_U64_ALIGNMENT
2854	def_bool y
2855
2856config SYSVIPC_COMPAT
2857	def_bool y
2858	depends on SYSVIPC
2859endif
2860
2861endmenu
2862
2863
2864config HAVE_ATOMIC_IOMAP
2865	def_bool y
2866	depends on X86_32
2867
2868config X86_DEV_DMA_OPS
2869	bool
2870
2871config HAVE_GENERIC_GUP
2872	def_bool y
2873
2874source "drivers/firmware/Kconfig"
2875
2876source "arch/x86/kvm/Kconfig"
2877