xref: /linux/arch/x86/Kconfig (revision c6ed444fd6fffaaf2e3857d926ed18bf3df81e8e)
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_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select X86_DEV_DMA_OPS
34	select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40#   ported to 32-bit as well. )
41#
42config X86
43	def_bool y
44	#
45	# Note: keep this list sorted alphabetically
46	#
47	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
48	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
49	select ANON_INODES
50	select ARCH_CLOCKSOURCE_DATA
51	select ARCH_DISCARD_MEMBLOCK
52	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53	select ARCH_HAS_DEBUG_VIRTUAL
54	select ARCH_HAS_DEVMEM_IS_ALLOWED
55	select ARCH_HAS_ELF_RANDOMIZE
56	select ARCH_HAS_FAST_MULTIPLIER
57	select ARCH_HAS_FILTER_PGPROT
58	select ARCH_HAS_FORTIFY_SOURCE
59	select ARCH_HAS_GCOV_PROFILE_ALL
60	select ARCH_HAS_KCOV			if X86_64
61	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62	select ARCH_HAS_PMEM_API		if X86_64
63	select ARCH_HAS_PTE_SPECIAL
64	select ARCH_HAS_REFCOUNT
65	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
66	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
67	select ARCH_HAS_SET_MEMORY
68	select ARCH_HAS_SG_CHAIN
69	select ARCH_HAS_STRICT_KERNEL_RWX
70	select ARCH_HAS_STRICT_MODULE_RWX
71	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
72	select ARCH_HAS_UBSAN_SANITIZE_ALL
73	select ARCH_HAS_ZONE_DEVICE		if X86_64
74	select ARCH_HAVE_NMI_SAFE_CMPXCHG
75	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
76	select ARCH_MIGHT_HAVE_PC_PARPORT
77	select ARCH_MIGHT_HAVE_PC_SERIO
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 DMA_DIRECT_OPS
92	select EDAC_ATOMIC_SCRUB
93	select EDAC_SUPPORT
94	select GENERIC_CLOCKEVENTS
95	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
96	select GENERIC_CLOCKEVENTS_MIN_ADJUST
97	select GENERIC_CMOS_UPDATE
98	select GENERIC_CPU_AUTOPROBE
99	select GENERIC_CPU_VULNERABILITIES
100	select GENERIC_EARLY_IOREMAP
101	select GENERIC_FIND_FIRST_BIT
102	select GENERIC_IOMAP
103	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
104	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
105	select GENERIC_IRQ_MIGRATION		if SMP
106	select GENERIC_IRQ_PROBE
107	select GENERIC_IRQ_RESERVATION_MODE
108	select GENERIC_IRQ_SHOW
109	select GENERIC_PENDING_IRQ		if SMP
110	select GENERIC_SMP_IDLE_THREAD
111	select GENERIC_STRNCPY_FROM_USER
112	select GENERIC_STRNLEN_USER
113	select GENERIC_TIME_VSYSCALL
114	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
115	select HAVE_ACPI_APEI			if ACPI
116	select HAVE_ACPI_APEI_NMI		if ACPI
117	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
118	select HAVE_ARCH_AUDITSYSCALL
119	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
120	select HAVE_ARCH_JUMP_LABEL
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_SECCOMP_FILTER
127	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
128	select HAVE_ARCH_TRACEHOOK
129	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
130	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
131	select HAVE_ARCH_VMAP_STACK		if X86_64
132	select HAVE_ARCH_WITHIN_STACK_FRAMES
133	select HAVE_CMPXCHG_DOUBLE
134	select HAVE_CMPXCHG_LOCAL
135	select HAVE_CONTEXT_TRACKING		if X86_64
136	select HAVE_COPY_THREAD_TLS
137	select HAVE_C_RECORDMCOUNT
138	select HAVE_DEBUG_KMEMLEAK
139	select HAVE_DEBUG_STACKOVERFLOW
140	select HAVE_DMA_CONTIGUOUS
141	select HAVE_DYNAMIC_FTRACE
142	select HAVE_DYNAMIC_FTRACE_WITH_REGS
143	select HAVE_EBPF_JIT
144	select HAVE_EFFICIENT_UNALIGNED_ACCESS
145	select HAVE_EXIT_THREAD
146	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
147	select HAVE_FTRACE_MCOUNT_RECORD
148	select HAVE_FUNCTION_GRAPH_TRACER
149	select HAVE_FUNCTION_TRACER
150	select HAVE_GCC_PLUGINS
151	select HAVE_HW_BREAKPOINT
152	select HAVE_IDE
153	select HAVE_IOREMAP_PROT
154	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
155	select HAVE_IRQ_TIME_ACCOUNTING
156	select HAVE_KERNEL_BZIP2
157	select HAVE_KERNEL_GZIP
158	select HAVE_KERNEL_LZ4
159	select HAVE_KERNEL_LZMA
160	select HAVE_KERNEL_LZO
161	select HAVE_KERNEL_XZ
162	select HAVE_KPROBES
163	select HAVE_KPROBES_ON_FTRACE
164	select HAVE_FUNCTION_ERROR_INJECTION
165	select HAVE_KRETPROBES
166	select HAVE_KVM
167	select HAVE_LIVEPATCH			if X86_64
168	select HAVE_MEMBLOCK
169	select HAVE_MEMBLOCK_NODE_MAP
170	select HAVE_MIXED_BREAKPOINTS_REGS
171	select HAVE_MOD_ARCH_SPECIFIC
172	select HAVE_NMI
173	select HAVE_OPROFILE
174	select HAVE_OPTPROBES
175	select HAVE_PCSPKR_PLATFORM
176	select HAVE_PERF_EVENTS
177	select HAVE_PERF_EVENTS_NMI
178	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
179	select HAVE_PERF_REGS
180	select HAVE_PERF_USER_STACK_DUMP
181	select HAVE_RCU_TABLE_FREE
182	select HAVE_REGS_AND_STACK_ACCESS_API
183	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
184	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
185	select HAVE_STACK_VALIDATION		if X86_64
186	select HAVE_RSEQ
187	select HAVE_SYSCALL_TRACEPOINTS
188	select HAVE_UNSTABLE_SCHED_CLOCK
189	select HAVE_USER_RETURN_NOTIFIER
190	select HOTPLUG_SMT			if SMP
191	select IRQ_FORCED_THREADING
192	select NEED_SG_DMA_LENGTH
193	select PCI_LOCKLESS_CONFIG
194	select PERF_EVENTS
195	select RTC_LIB
196	select RTC_MC146818_LIB
197	select SPARSE_IRQ
198	select SRCU
199	select SYSCTL_EXCEPTION_TRACE
200	select THREAD_INFO_IN_TASK
201	select USER_STACKTRACE_SUPPORT
202	select VIRT_TO_BUS
203	select X86_FEATURE_NAMES		if PROC_FS
204
205config INSTRUCTION_DECODER
206	def_bool y
207	depends on KPROBES || PERF_EVENTS || UPROBES
208
209config OUTPUT_FORMAT
210	string
211	default "elf32-i386" if X86_32
212	default "elf64-x86-64" if X86_64
213
214config ARCH_DEFCONFIG
215	string
216	default "arch/x86/configs/i386_defconfig" if X86_32
217	default "arch/x86/configs/x86_64_defconfig" if X86_64
218
219config LOCKDEP_SUPPORT
220	def_bool y
221
222config STACKTRACE_SUPPORT
223	def_bool y
224
225config MMU
226	def_bool y
227
228config ARCH_MMAP_RND_BITS_MIN
229	default 28 if 64BIT
230	default 8
231
232config ARCH_MMAP_RND_BITS_MAX
233	default 32 if 64BIT
234	default 16
235
236config ARCH_MMAP_RND_COMPAT_BITS_MIN
237	default 8
238
239config ARCH_MMAP_RND_COMPAT_BITS_MAX
240	default 16
241
242config SBUS
243	bool
244
245config GENERIC_ISA_DMA
246	def_bool y
247	depends on ISA_DMA_API
248
249config GENERIC_BUG
250	def_bool y
251	depends on BUG
252	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
253
254config GENERIC_BUG_RELATIVE_POINTERS
255	bool
256
257config GENERIC_HWEIGHT
258	def_bool y
259
260config ARCH_MAY_HAVE_PC_FDC
261	def_bool y
262	depends on ISA_DMA_API
263
264config RWSEM_XCHGADD_ALGORITHM
265	def_bool y
266
267config GENERIC_CALIBRATE_DELAY
268	def_bool y
269
270config ARCH_HAS_CPU_RELAX
271	def_bool y
272
273config ARCH_HAS_CACHE_LINE_SIZE
274	def_bool y
275
276config ARCH_HAS_FILTER_PGPROT
277	def_bool y
278
279config HAVE_SETUP_PER_CPU_AREA
280	def_bool y
281
282config NEED_PER_CPU_EMBED_FIRST_CHUNK
283	def_bool y
284
285config NEED_PER_CPU_PAGE_FIRST_CHUNK
286	def_bool y
287
288config ARCH_HIBERNATION_POSSIBLE
289	def_bool y
290
291config ARCH_SUSPEND_POSSIBLE
292	def_bool y
293
294config ARCH_WANT_HUGE_PMD_SHARE
295	def_bool y
296
297config ARCH_WANT_GENERAL_HUGETLB
298	def_bool y
299
300config ZONE_DMA32
301	def_bool y if X86_64
302
303config AUDIT_ARCH
304	def_bool y if X86_64
305
306config ARCH_SUPPORTS_OPTIMIZED_INLINING
307	def_bool y
308
309config ARCH_SUPPORTS_DEBUG_PAGEALLOC
310	def_bool y
311
312config KASAN_SHADOW_OFFSET
313	hex
314	depends on KASAN
315	default 0xdffffc0000000000
316
317config HAVE_INTEL_TXT
318	def_bool y
319	depends on INTEL_IOMMU && ACPI
320
321config X86_32_SMP
322	def_bool y
323	depends on X86_32 && SMP
324
325config X86_64_SMP
326	def_bool y
327	depends on X86_64 && SMP
328
329config X86_32_LAZY_GS
330	def_bool y
331	depends on X86_32 && !STACKPROTECTOR
332
333config ARCH_SUPPORTS_UPROBES
334	def_bool y
335
336config FIX_EARLYCON_MEM
337	def_bool y
338
339config DYNAMIC_PHYSICAL_MASK
340	bool
341
342config PGTABLE_LEVELS
343	int
344	default 5 if X86_5LEVEL
345	default 4 if X86_64
346	default 3 if X86_PAE
347	default 2
348
349source "init/Kconfig"
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
359source "kernel/Kconfig.freezer"
360
361menu "Processor type and features"
362
363config ZONE_DMA
364	bool "DMA memory allocation support" if EXPERT
365	default y
366	help
367	  DMA memory allocation support allows devices with less than 32-bit
368	  addressing to allocate within the first 16MB of address space.
369	  Disable if no such devices will be used.
370
371	  If unsure, say Y.
372
373config SMP
374	bool "Symmetric multi-processing support"
375	---help---
376	  This enables support for systems with more than one CPU. If you have
377	  a system with only one CPU, say N. If you have a system with more
378	  than one CPU, say Y.
379
380	  If you say N here, the kernel will run on uni- and multiprocessor
381	  machines, but will use only one CPU of a multiprocessor machine. If
382	  you say Y here, the kernel will run on many, but not all,
383	  uniprocessor machines. On a uniprocessor machine, the kernel
384	  will run faster if you say N here.
385
386	  Note that if you say Y here and choose architecture "586" or
387	  "Pentium" under "Processor family", the kernel will not work on 486
388	  architectures. Similarly, multiprocessor kernels for the "PPro"
389	  architecture may not work on all Pentium based boards.
390
391	  People using multiprocessor machines who say Y here should also say
392	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
393	  Management" code will be disabled if you say Y here.
394
395	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
396	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
397	  <http://www.tldp.org/docs.html#howto>.
398
399	  If you don't know what to do here, say N.
400
401config X86_FEATURE_NAMES
402	bool "Processor feature human-readable names" if EMBEDDED
403	default y
404	---help---
405	  This option compiles in a table of x86 feature bits and corresponding
406	  names.  This is required to support /proc/cpuinfo and a few kernel
407	  messages.  You can disable this to save space, at the expense of
408	  making those few kernel messages show numeric feature bits instead.
409
410	  If in doubt, say Y.
411
412config X86_X2APIC
413	bool "Support x2apic"
414	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
415	---help---
416	  This enables x2apic support on CPUs that have this feature.
417
418	  This allows 32-bit apic IDs (so it can support very large systems),
419	  and accesses the local apic via MSRs not via mmio.
420
421	  If you don't know what to do here, say N.
422
423config X86_MPPARSE
424	bool "Enable MPS table" if ACPI || SFI
425	default y
426	depends on X86_LOCAL_APIC
427	---help---
428	  For old smp systems that do not have proper acpi support. Newer systems
429	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
430
431config GOLDFISH
432       def_bool y
433       depends on X86_GOLDFISH
434
435config RETPOLINE
436	bool "Avoid speculative indirect branches in kernel"
437	default y
438	select STACK_VALIDATION if HAVE_STACK_VALIDATION
439	help
440	  Compile kernel with the retpoline compiler options to guard against
441	  kernel-to-user data leaks by avoiding speculative indirect
442	  branches. Requires a compiler with -mindirect-branch=thunk-extern
443	  support for full protection. The kernel may run slower.
444
445	  Without compiler support, at least indirect branches in assembler
446	  code are eliminated. Since this includes the syscall entry path,
447	  it is not entirely pointless.
448
449config INTEL_RDT
450	bool "Intel Resource Director Technology support"
451	default n
452	depends on X86 && CPU_SUP_INTEL
453	select KERNFS
454	help
455	  Select to enable resource allocation and monitoring which are
456	  sub-features of Intel Resource Director Technology(RDT). More
457	  information about RDT can be found in the Intel x86
458	  Architecture Software Developer Manual.
459
460	  Say N if unsure.
461
462if X86_32
463config X86_BIGSMP
464	bool "Support for big SMP systems with more than 8 CPUs"
465	depends on SMP
466	---help---
467	  This option is needed for the systems that have more than 8 CPUs
468
469config X86_EXTENDED_PLATFORM
470	bool "Support for extended (non-PC) x86 platforms"
471	default y
472	---help---
473	  If you disable this option then the kernel will only support
474	  standard PC platforms. (which covers the vast majority of
475	  systems out there.)
476
477	  If you enable this option then you'll be able to select support
478	  for the following (non-PC) 32 bit x86 platforms:
479		Goldfish (Android emulator)
480		AMD Elan
481		RDC R-321x SoC
482		SGI 320/540 (Visual Workstation)
483		STA2X11-based (e.g. Northville)
484		Moorestown MID devices
485
486	  If you have one of these systems, or if you want to build a
487	  generic distribution kernel, say Y here - otherwise say N.
488endif
489
490if X86_64
491config X86_EXTENDED_PLATFORM
492	bool "Support for extended (non-PC) x86 platforms"
493	default y
494	---help---
495	  If you disable this option then the kernel will only support
496	  standard PC platforms. (which covers the vast majority of
497	  systems out there.)
498
499	  If you enable this option then you'll be able to select support
500	  for the following (non-PC) 64 bit x86 platforms:
501		Numascale NumaChip
502		ScaleMP vSMP
503		SGI Ultraviolet
504
505	  If you have one of these systems, or if you want to build a
506	  generic distribution kernel, say Y here - otherwise say N.
507endif
508# This is an alphabetically sorted list of 64 bit extended platforms
509# Please maintain the alphabetic order if and when there are additions
510config X86_NUMACHIP
511	bool "Numascale NumaChip"
512	depends on X86_64
513	depends on X86_EXTENDED_PLATFORM
514	depends on NUMA
515	depends on SMP
516	depends on X86_X2APIC
517	depends on PCI_MMCONFIG
518	---help---
519	  Adds support for Numascale NumaChip large-SMP systems. Needed to
520	  enable more than ~168 cores.
521	  If you don't have one of these, you should say N here.
522
523config X86_VSMP
524	bool "ScaleMP vSMP"
525	select HYPERVISOR_GUEST
526	select PARAVIRT
527	depends on X86_64 && PCI
528	depends on X86_EXTENDED_PLATFORM
529	depends on SMP
530	---help---
531	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
532	  supposed to run on these EM64T-based machines.  Only choose this option
533	  if you have one of these machines.
534
535config X86_UV
536	bool "SGI Ultraviolet"
537	depends on X86_64
538	depends on X86_EXTENDED_PLATFORM
539	depends on NUMA
540	depends on EFI
541	depends on X86_X2APIC
542	depends on PCI
543	---help---
544	  This option is needed in order to support SGI Ultraviolet systems.
545	  If you don't have one of these, you should say N here.
546
547# Following is an alphabetically sorted list of 32 bit extended platforms
548# Please maintain the alphabetic order if and when there are additions
549
550config X86_GOLDFISH
551       bool "Goldfish (Virtual Platform)"
552       depends on X86_EXTENDED_PLATFORM
553       ---help---
554	 Enable support for the Goldfish virtual platform used primarily
555	 for Android development. Unless you are building for the Android
556	 Goldfish emulator say N here.
557
558config X86_INTEL_CE
559	bool "CE4100 TV platform"
560	depends on PCI
561	depends on PCI_GODIRECT
562	depends on X86_IO_APIC
563	depends on X86_32
564	depends on X86_EXTENDED_PLATFORM
565	select X86_REBOOTFIXUPS
566	select OF
567	select OF_EARLY_FLATTREE
568	---help---
569	  Select for the Intel CE media processor (CE4100) SOC.
570	  This option compiles in support for the CE4100 SOC for settop
571	  boxes and media devices.
572
573config X86_INTEL_MID
574	bool "Intel MID platform support"
575	depends on X86_EXTENDED_PLATFORM
576	depends on X86_PLATFORM_DEVICES
577	depends on PCI
578	depends on X86_64 || (PCI_GOANY && X86_32)
579	depends on X86_IO_APIC
580	select SFI
581	select I2C
582	select DW_APB_TIMER
583	select APB_TIMER
584	select INTEL_SCU_IPC
585	select MFD_INTEL_MSIC
586	---help---
587	  Select to build a kernel capable of supporting Intel MID (Mobile
588	  Internet Device) platform systems which do not have the PCI legacy
589	  interfaces. If you are building for a PC class system say N here.
590
591	  Intel MID platforms are based on an Intel processor and chipset which
592	  consume less power than most of the x86 derivatives.
593
594config X86_INTEL_QUARK
595	bool "Intel Quark platform support"
596	depends on X86_32
597	depends on X86_EXTENDED_PLATFORM
598	depends on X86_PLATFORM_DEVICES
599	depends on X86_TSC
600	depends on PCI
601	depends on PCI_GOANY
602	depends on X86_IO_APIC
603	select IOSF_MBI
604	select INTEL_IMR
605	select COMMON_CLK
606	---help---
607	  Select to include support for Quark X1000 SoC.
608	  Say Y here if you have a Quark based system such as the Arduino
609	  compatible Intel Galileo.
610
611config X86_INTEL_LPSS
612	bool "Intel Low Power Subsystem Support"
613	depends on X86 && ACPI
614	select COMMON_CLK
615	select PINCTRL
616	select IOSF_MBI
617	---help---
618	  Select to build support for Intel Low Power Subsystem such as
619	  found on Intel Lynxpoint PCH. Selecting this option enables
620	  things like clock tree (common clock framework) and pincontrol
621	  which are needed by the LPSS peripheral drivers.
622
623config X86_AMD_PLATFORM_DEVICE
624	bool "AMD ACPI2Platform devices support"
625	depends on ACPI
626	select COMMON_CLK
627	select PINCTRL
628	---help---
629	  Select to interpret AMD specific ACPI device to platform device
630	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
631	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
632	  implemented under PINCTRL subsystem.
633
634config IOSF_MBI
635	tristate "Intel SoC IOSF Sideband support for SoC platforms"
636	depends on PCI
637	---help---
638	  This option enables sideband register access support for Intel SoC
639	  platforms. On these platforms the IOSF sideband is used in lieu of
640	  MSR's for some register accesses, mostly but not limited to thermal
641	  and power. Drivers may query the availability of this device to
642	  determine if they need the sideband in order to work on these
643	  platforms. The sideband is available on the following SoC products.
644	  This list is not meant to be exclusive.
645	   - BayTrail
646	   - Braswell
647	   - Quark
648
649	  You should say Y if you are running a kernel on one of these SoC's.
650
651config IOSF_MBI_DEBUG
652	bool "Enable IOSF sideband access through debugfs"
653	depends on IOSF_MBI && DEBUG_FS
654	---help---
655	  Select this option to expose the IOSF sideband access registers (MCR,
656	  MDR, MCRX) through debugfs to write and read register information from
657	  different units on the SoC. This is most useful for obtaining device
658	  state information for debug and analysis. As this is a general access
659	  mechanism, users of this option would have specific knowledge of the
660	  device they want to access.
661
662	  If you don't require the option or are in doubt, say N.
663
664config X86_RDC321X
665	bool "RDC R-321x SoC"
666	depends on X86_32
667	depends on X86_EXTENDED_PLATFORM
668	select M486
669	select X86_REBOOTFIXUPS
670	---help---
671	  This option is needed for RDC R-321x system-on-chip, also known
672	  as R-8610-(G).
673	  If you don't have one of these chips, you should say N here.
674
675config X86_32_NON_STANDARD
676	bool "Support non-standard 32-bit SMP architectures"
677	depends on X86_32 && SMP
678	depends on X86_EXTENDED_PLATFORM
679	---help---
680	  This option compiles in the bigsmp and STA2X11 default
681	  subarchitectures.  It is intended for a generic binary
682	  kernel. If you select them all, kernel will probe it one by
683	  one and will fallback to default.
684
685# Alphabetically sorted list of Non standard 32 bit platforms
686
687config X86_SUPPORTS_MEMORY_FAILURE
688	def_bool y
689	# MCE code calls memory_failure():
690	depends on X86_MCE
691	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
692	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
693	depends on X86_64 || !SPARSEMEM
694	select ARCH_SUPPORTS_MEMORY_FAILURE
695
696config STA2X11
697	bool "STA2X11 Companion Chip Support"
698	depends on X86_32_NON_STANDARD && PCI
699	select ARCH_HAS_PHYS_TO_DMA
700	select X86_DEV_DMA_OPS
701	select X86_DMA_REMAP
702	select SWIOTLB
703	select MFD_STA2X11
704	select GPIOLIB
705	default n
706	---help---
707	  This adds support for boards based on the STA2X11 IO-Hub,
708	  a.k.a. "ConneXt". The chip is used in place of the standard
709	  PC chipset, so all "standard" peripherals are missing. If this
710	  option is selected the kernel will still be able to boot on
711	  standard PC machines.
712
713config X86_32_IRIS
714	tristate "Eurobraille/Iris poweroff module"
715	depends on X86_32
716	---help---
717	  The Iris machines from EuroBraille do not have APM or ACPI support
718	  to shut themselves down properly.  A special I/O sequence is
719	  needed to do so, which is what this module does at
720	  kernel shutdown.
721
722	  This is only for Iris machines from EuroBraille.
723
724	  If unused, say N.
725
726config SCHED_OMIT_FRAME_POINTER
727	def_bool y
728	prompt "Single-depth WCHAN output"
729	depends on X86
730	---help---
731	  Calculate simpler /proc/<PID>/wchan values. If this option
732	  is disabled then wchan values will recurse back to the
733	  caller function. This provides more accurate wchan values,
734	  at the expense of slightly more scheduling overhead.
735
736	  If in doubt, say "Y".
737
738menuconfig HYPERVISOR_GUEST
739	bool "Linux guest support"
740	---help---
741	  Say Y here to enable options for running Linux under various hyper-
742	  visors. This option enables basic hypervisor detection and platform
743	  setup.
744
745	  If you say N, all options in this submenu will be skipped and
746	  disabled, and Linux guest support won't be built in.
747
748if HYPERVISOR_GUEST
749
750config PARAVIRT
751	bool "Enable paravirtualization code"
752	---help---
753	  This changes the kernel so it can modify itself when it is run
754	  under a hypervisor, potentially improving performance significantly
755	  over full virtualization.  However, when run without a hypervisor
756	  the kernel is theoretically slower and slightly larger.
757
758config PARAVIRT_DEBUG
759	bool "paravirt-ops debugging"
760	depends on PARAVIRT && DEBUG_KERNEL
761	---help---
762	  Enable to debug paravirt_ops internals.  Specifically, BUG if
763	  a paravirt_op is missing when it is called.
764
765config PARAVIRT_SPINLOCKS
766	bool "Paravirtualization layer for spinlocks"
767	depends on PARAVIRT && SMP
768	---help---
769	  Paravirtualized spinlocks allow a pvops backend to replace the
770	  spinlock implementation with something virtualization-friendly
771	  (for example, block the virtual CPU rather than spinning).
772
773	  It has a minimal impact on native kernels and gives a nice performance
774	  benefit on paravirtualized KVM / Xen kernels.
775
776	  If you are unsure how to answer this question, answer Y.
777
778config QUEUED_LOCK_STAT
779	bool "Paravirt queued spinlock statistics"
780	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
781	---help---
782	  Enable the collection of statistical data on the slowpath
783	  behavior of paravirtualized queued spinlocks and report
784	  them on debugfs.
785
786source "arch/x86/xen/Kconfig"
787
788config KVM_GUEST
789	bool "KVM Guest support (including kvmclock)"
790	depends on PARAVIRT
791	select PARAVIRT_CLOCK
792	default y
793	---help---
794	  This option enables various optimizations for running under the KVM
795	  hypervisor. It includes a paravirtualized clock, so that instead
796	  of relying on a PIT (or probably other) emulation by the
797	  underlying device model, the host provides the guest with
798	  timing infrastructure such as time of day, and system time
799
800config KVM_DEBUG_FS
801	bool "Enable debug information for KVM Guests in debugfs"
802	depends on KVM_GUEST && DEBUG_FS
803	default n
804	---help---
805	  This option enables collection of various statistics for KVM guest.
806	  Statistics are displayed in debugfs filesystem. Enabling this option
807	  may incur significant overhead.
808
809config PARAVIRT_TIME_ACCOUNTING
810	bool "Paravirtual steal time accounting"
811	depends on PARAVIRT
812	default n
813	---help---
814	  Select this option to enable fine granularity task steal time
815	  accounting. Time spent executing other tasks in parallel with
816	  the current vCPU is discounted from the vCPU power. To account for
817	  that, there can be a small performance impact.
818
819	  If in doubt, say N here.
820
821config PARAVIRT_CLOCK
822	bool
823
824config JAILHOUSE_GUEST
825	bool "Jailhouse non-root cell support"
826	depends on X86_64 && PCI
827	select X86_PM_TIMER
828	---help---
829	  This option allows to run Linux as guest in a Jailhouse non-root
830	  cell. You can leave this option disabled if you only want to start
831	  Jailhouse and run Linux afterwards in the root cell.
832
833endif #HYPERVISOR_GUEST
834
835config NO_BOOTMEM
836	def_bool y
837
838source "arch/x86/Kconfig.cpu"
839
840config HPET_TIMER
841	def_bool X86_64
842	prompt "HPET Timer Support" if X86_32
843	---help---
844	  Use the IA-PC HPET (High Precision Event Timer) to manage
845	  time in preference to the PIT and RTC, if a HPET is
846	  present.
847	  HPET is the next generation timer replacing legacy 8254s.
848	  The HPET provides a stable time base on SMP
849	  systems, unlike the TSC, but it is more expensive to access,
850	  as it is off-chip.  The interface used is documented
851	  in the HPET spec, revision 1.
852
853	  You can safely choose Y here.  However, HPET will only be
854	  activated if the platform and the BIOS support this feature.
855	  Otherwise the 8254 will be used for timing services.
856
857	  Choose N to continue using the legacy 8254 timer.
858
859config HPET_EMULATE_RTC
860	def_bool y
861	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
862
863config APB_TIMER
864       def_bool y if X86_INTEL_MID
865       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
866       select DW_APB_TIMER
867       depends on X86_INTEL_MID && SFI
868       help
869         APB timer is the replacement for 8254, HPET on X86 MID platforms.
870         The APBT provides a stable time base on SMP
871         systems, unlike the TSC, but it is more expensive to access,
872         as it is off-chip. APB timers are always running regardless of CPU
873         C states, they are used as per CPU clockevent device when possible.
874
875# Mark as expert because too many people got it wrong.
876# The code disables itself when not needed.
877config DMI
878	default y
879	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
880	bool "Enable DMI scanning" if EXPERT
881	---help---
882	  Enabled scanning of DMI to identify machine quirks. Say Y
883	  here unless you have verified that your setup is not
884	  affected by entries in the DMI blacklist. Required by PNP
885	  BIOS code.
886
887config GART_IOMMU
888	bool "Old AMD GART IOMMU support"
889	select IOMMU_HELPER
890	select SWIOTLB
891	depends on X86_64 && PCI && AMD_NB
892	---help---
893	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
894	  GART based hardware IOMMUs.
895
896	  The GART supports full DMA access for devices with 32-bit access
897	  limitations, on systems with more than 3 GB. This is usually needed
898	  for USB, sound, many IDE/SATA chipsets and some other devices.
899
900	  Newer systems typically have a modern AMD IOMMU, supported via
901	  the CONFIG_AMD_IOMMU=y config option.
902
903	  In normal configurations this driver is only active when needed:
904	  there's more than 3 GB of memory and the system contains a
905	  32-bit limited device.
906
907	  If unsure, say Y.
908
909config CALGARY_IOMMU
910	bool "IBM Calgary IOMMU support"
911	select IOMMU_HELPER
912	select SWIOTLB
913	depends on X86_64 && PCI
914	---help---
915	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
916	  systems. Needed to run systems with more than 3GB of memory
917	  properly with 32-bit PCI devices that do not support DAC
918	  (Double Address Cycle). Calgary also supports bus level
919	  isolation, where all DMAs pass through the IOMMU.  This
920	  prevents them from going anywhere except their intended
921	  destination. This catches hard-to-find kernel bugs and
922	  mis-behaving drivers and devices that do not use the DMA-API
923	  properly to set up their DMA buffers.  The IOMMU can be
924	  turned off at boot time with the iommu=off parameter.
925	  Normally the kernel will make the right choice by itself.
926	  If unsure, say Y.
927
928config CALGARY_IOMMU_ENABLED_BY_DEFAULT
929	def_bool y
930	prompt "Should Calgary be enabled by default?"
931	depends on CALGARY_IOMMU
932	---help---
933	  Should Calgary be enabled by default? if you choose 'y', Calgary
934	  will be used (if it exists). If you choose 'n', Calgary will not be
935	  used even if it exists. If you choose 'n' and would like to use
936	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
937	  If unsure, say Y.
938
939config MAXSMP
940	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
941	depends on X86_64 && SMP && DEBUG_KERNEL
942	select CPUMASK_OFFSTACK
943	---help---
944	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
945	  If unsure, say N.
946
947#
948# The maximum number of CPUs supported:
949#
950# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951# and which can be configured interactively in the
952# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953#
954# The ranges are different on 32-bit and 64-bit kernels, depending on
955# hardware capabilities and scalability features of the kernel.
956#
957# ( If MAXSMP is enabled we just use the highest possible value and disable
958#   interactive configuration. )
959#
960
961config NR_CPUS_RANGE_BEGIN
962	int
963	default NR_CPUS_RANGE_END if MAXSMP
964	default    1 if !SMP
965	default    2
966
967config NR_CPUS_RANGE_END
968	int
969	depends on X86_32
970	default   64 if  SMP &&  X86_BIGSMP
971	default    8 if  SMP && !X86_BIGSMP
972	default    1 if !SMP
973
974config NR_CPUS_RANGE_END
975	int
976	depends on X86_64
977	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
978	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
979	default    1 if !SMP
980
981config NR_CPUS_DEFAULT
982	int
983	depends on X86_32
984	default   32 if  X86_BIGSMP
985	default    8 if  SMP
986	default    1 if !SMP
987
988config NR_CPUS_DEFAULT
989	int
990	depends on X86_64
991	default 8192 if  MAXSMP
992	default   64 if  SMP
993	default    1 if !SMP
994
995config NR_CPUS
996	int "Maximum number of CPUs" if SMP && !MAXSMP
997	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998	default NR_CPUS_DEFAULT
999	---help---
1000	  This allows you to specify the maximum number of CPUs which this
1001	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1002	  supported value is 8192, otherwise the maximum value is 512.  The
1003	  minimum value which makes sense is 2.
1004
1005	  This is purely to save memory: each supported CPU adds about 8KB
1006	  to the kernel image.
1007
1008config SCHED_SMT
1009	bool "SMT (Hyperthreading) scheduler support"
1010	depends on SMP
1011	---help---
1012	  SMT scheduler support improves the CPU scheduler's decision making
1013	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1014	  cost of slightly increased overhead in some places. If unsure say
1015	  N here.
1016
1017config SCHED_MC
1018	def_bool y
1019	prompt "Multi-core scheduler support"
1020	depends on SMP
1021	---help---
1022	  Multi-core scheduler support improves the CPU scheduler's decision
1023	  making when dealing with multi-core CPU chips at a cost of slightly
1024	  increased overhead in some places. If unsure say N here.
1025
1026config SCHED_MC_PRIO
1027	bool "CPU core priorities scheduler support"
1028	depends on SCHED_MC && CPU_SUP_INTEL
1029	select X86_INTEL_PSTATE
1030	select CPU_FREQ
1031	default y
1032	---help---
1033	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1034	  core ordering determined at manufacturing time, which allows
1035	  certain cores to reach higher turbo frequencies (when running
1036	  single threaded workloads) than others.
1037
1038	  Enabling this kernel feature teaches the scheduler about
1039	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1040	  scheduler's CPU selection logic accordingly, so that higher
1041	  overall system performance can be achieved.
1042
1043	  This feature will have no effect on CPUs without this feature.
1044
1045	  If unsure say Y here.
1046
1047source "kernel/Kconfig.preempt"
1048
1049config UP_LATE_INIT
1050       def_bool y
1051       depends on !SMP && X86_LOCAL_APIC
1052
1053config X86_UP_APIC
1054	bool "Local APIC support on uniprocessors" if !PCI_MSI
1055	default PCI_MSI
1056	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1057	---help---
1058	  A local APIC (Advanced Programmable Interrupt Controller) is an
1059	  integrated interrupt controller in the CPU. If you have a single-CPU
1060	  system which has a processor with a local APIC, you can say Y here to
1061	  enable and use it. If you say Y here even though your machine doesn't
1062	  have a local APIC, then the kernel will still run with no slowdown at
1063	  all. The local APIC supports CPU-generated self-interrupts (timer,
1064	  performance counters), and the NMI watchdog which detects hard
1065	  lockups.
1066
1067config X86_UP_IOAPIC
1068	bool "IO-APIC support on uniprocessors"
1069	depends on X86_UP_APIC
1070	---help---
1071	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1072	  SMP-capable replacement for PC-style interrupt controllers. Most
1073	  SMP systems and many recent uniprocessor systems have one.
1074
1075	  If you have a single-CPU system with an IO-APIC, you can say Y here
1076	  to use it. If you say Y here even though your machine doesn't have
1077	  an IO-APIC, then the kernel will still run with no slowdown at all.
1078
1079config X86_LOCAL_APIC
1080	def_bool y
1081	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1082	select IRQ_DOMAIN_HIERARCHY
1083	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1084
1085config X86_IO_APIC
1086	def_bool y
1087	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1088
1089config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1090	bool "Reroute for broken boot IRQs"
1091	depends on X86_IO_APIC
1092	---help---
1093	  This option enables a workaround that fixes a source of
1094	  spurious interrupts. This is recommended when threaded
1095	  interrupt handling is used on systems where the generation of
1096	  superfluous "boot interrupts" cannot be disabled.
1097
1098	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1099	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1100	  kernel does during interrupt handling). On chipsets where this
1101	  boot IRQ generation cannot be disabled, this workaround keeps
1102	  the original IRQ line masked so that only the equivalent "boot
1103	  IRQ" is delivered to the CPUs. The workaround also tells the
1104	  kernel to set up the IRQ handler on the boot IRQ line. In this
1105	  way only one interrupt is delivered to the kernel. Otherwise
1106	  the spurious second interrupt may cause the kernel to bring
1107	  down (vital) interrupt lines.
1108
1109	  Only affects "broken" chipsets. Interrupt sharing may be
1110	  increased on these systems.
1111
1112config X86_MCE
1113	bool "Machine Check / overheating reporting"
1114	select GENERIC_ALLOCATOR
1115	default y
1116	---help---
1117	  Machine Check support allows the processor to notify the
1118	  kernel if it detects a problem (e.g. overheating, data corruption).
1119	  The action the kernel takes depends on the severity of the problem,
1120	  ranging from warning messages to halting the machine.
1121
1122config X86_MCELOG_LEGACY
1123	bool "Support for deprecated /dev/mcelog character device"
1124	depends on X86_MCE
1125	---help---
1126	  Enable support for /dev/mcelog which is needed by the old mcelog
1127	  userspace logging daemon. Consider switching to the new generation
1128	  rasdaemon solution.
1129
1130config X86_MCE_INTEL
1131	def_bool y
1132	prompt "Intel MCE features"
1133	depends on X86_MCE && X86_LOCAL_APIC
1134	---help---
1135	   Additional support for intel specific MCE features such as
1136	   the thermal monitor.
1137
1138config X86_MCE_AMD
1139	def_bool y
1140	prompt "AMD MCE features"
1141	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1142	---help---
1143	   Additional support for AMD specific MCE features such as
1144	   the DRAM Error Threshold.
1145
1146config X86_ANCIENT_MCE
1147	bool "Support for old Pentium 5 / WinChip machine checks"
1148	depends on X86_32 && X86_MCE
1149	---help---
1150	  Include support for machine check handling on old Pentium 5 or WinChip
1151	  systems. These typically need to be enabled explicitly on the command
1152	  line.
1153
1154config X86_MCE_THRESHOLD
1155	depends on X86_MCE_AMD || X86_MCE_INTEL
1156	def_bool y
1157
1158config X86_MCE_INJECT
1159	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1160	tristate "Machine check injector support"
1161	---help---
1162	  Provide support for injecting machine checks for testing purposes.
1163	  If you don't know what a machine check is and you don't do kernel
1164	  QA it is safe to say n.
1165
1166config X86_THERMAL_VECTOR
1167	def_bool y
1168	depends on X86_MCE_INTEL
1169
1170source "arch/x86/events/Kconfig"
1171
1172config X86_LEGACY_VM86
1173	bool "Legacy VM86 support"
1174	default n
1175	depends on X86_32
1176	---help---
1177	  This option allows user programs to put the CPU into V8086
1178	  mode, which is an 80286-era approximation of 16-bit real mode.
1179
1180	  Some very old versions of X and/or vbetool require this option
1181	  for user mode setting.  Similarly, DOSEMU will use it if
1182	  available to accelerate real mode DOS programs.  However, any
1183	  recent version of DOSEMU, X, or vbetool should be fully
1184	  functional even without kernel VM86 support, as they will all
1185	  fall back to software emulation. Nevertheless, if you are using
1186	  a 16-bit DOS program where 16-bit performance matters, vm86
1187	  mode might be faster than emulation and you might want to
1188	  enable this option.
1189
1190	  Note that any app that works on a 64-bit kernel is unlikely to
1191	  need this option, as 64-bit kernels don't, and can't, support
1192	  V8086 mode. This option is also unrelated to 16-bit protected
1193	  mode and is not needed to run most 16-bit programs under Wine.
1194
1195	  Enabling this option increases the complexity of the kernel
1196	  and slows down exception handling a tiny bit.
1197
1198	  If unsure, say N here.
1199
1200config VM86
1201       bool
1202       default X86_LEGACY_VM86
1203
1204config X86_16BIT
1205	bool "Enable support for 16-bit segments" if EXPERT
1206	default y
1207	depends on MODIFY_LDT_SYSCALL
1208	---help---
1209	  This option is required by programs like Wine to run 16-bit
1210	  protected mode legacy code on x86 processors.  Disabling
1211	  this option saves about 300 bytes on i386, or around 6K text
1212	  plus 16K runtime memory on x86-64,
1213
1214config X86_ESPFIX32
1215	def_bool y
1216	depends on X86_16BIT && X86_32
1217
1218config X86_ESPFIX64
1219	def_bool y
1220	depends on X86_16BIT && X86_64
1221
1222config X86_VSYSCALL_EMULATION
1223       bool "Enable vsyscall emulation" if EXPERT
1224       default y
1225       depends on X86_64
1226       ---help---
1227	 This enables emulation of the legacy vsyscall page.  Disabling
1228	 it is roughly equivalent to booting with vsyscall=none, except
1229	 that it will also disable the helpful warning if a program
1230	 tries to use a vsyscall.  With this option set to N, offending
1231	 programs will just segfault, citing addresses of the form
1232	 0xffffffffff600?00.
1233
1234	 This option is required by many programs built before 2013, and
1235	 care should be used even with newer programs if set to N.
1236
1237	 Disabling this option saves about 7K of kernel size and
1238	 possibly 4K of additional runtime pagetable memory.
1239
1240config TOSHIBA
1241	tristate "Toshiba Laptop support"
1242	depends on X86_32
1243	---help---
1244	  This adds a driver to safely access the System Management Mode of
1245	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1246	  not work on models with a Phoenix BIOS. The System Management Mode
1247	  is used to set the BIOS and power saving options on Toshiba portables.
1248
1249	  For information on utilities to make use of this driver see the
1250	  Toshiba Linux utilities web site at:
1251	  <http://www.buzzard.org.uk/toshiba/>.
1252
1253	  Say Y if you intend to run this kernel on a Toshiba portable.
1254	  Say N otherwise.
1255
1256config I8K
1257	tristate "Dell i8k legacy laptop support"
1258	select HWMON
1259	select SENSORS_DELL_SMM
1260	---help---
1261	  This option enables legacy /proc/i8k userspace interface in hwmon
1262	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1263	  temperature and allows controlling fan speeds of Dell laptops via
1264	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1265	  it reports also power and hotkey status. For fan speed control is
1266	  needed userspace package i8kutils.
1267
1268	  Say Y if you intend to run this kernel on old Dell laptops or want to
1269	  use userspace package i8kutils.
1270	  Say N otherwise.
1271
1272config X86_REBOOTFIXUPS
1273	bool "Enable X86 board specific fixups for reboot"
1274	depends on X86_32
1275	---help---
1276	  This enables chipset and/or board specific fixups to be done
1277	  in order to get reboot to work correctly. This is only needed on
1278	  some combinations of hardware and BIOS. The symptom, for which
1279	  this config is intended, is when reboot ends with a stalled/hung
1280	  system.
1281
1282	  Currently, the only fixup is for the Geode machines using
1283	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1284
1285	  Say Y if you want to enable the fixup. Currently, it's safe to
1286	  enable this option even if you don't need it.
1287	  Say N otherwise.
1288
1289config MICROCODE
1290	bool "CPU microcode loading support"
1291	default y
1292	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1293	select FW_LOADER
1294	---help---
1295	  If you say Y here, you will be able to update the microcode on
1296	  Intel and AMD processors. The Intel support is for the IA32 family,
1297	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1298	  AMD support is for families 0x10 and later. You will obviously need
1299	  the actual microcode binary data itself which is not shipped with
1300	  the Linux kernel.
1301
1302	  The preferred method to load microcode from a detached initrd is described
1303	  in Documentation/x86/microcode.txt. For that you need to enable
1304	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1305	  initrd for microcode blobs.
1306
1307	  In addition, you can build the microcode into the kernel. For that you
1308	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1309	  config option.
1310
1311config MICROCODE_INTEL
1312	bool "Intel microcode loading support"
1313	depends on MICROCODE
1314	default MICROCODE
1315	select FW_LOADER
1316	---help---
1317	  This options enables microcode patch loading support for Intel
1318	  processors.
1319
1320	  For the current Intel microcode data package go to
1321	  <https://downloadcenter.intel.com> and search for
1322	  'Linux Processor Microcode Data File'.
1323
1324config MICROCODE_AMD
1325	bool "AMD microcode loading support"
1326	depends on MICROCODE
1327	select FW_LOADER
1328	---help---
1329	  If you select this option, microcode patch loading support for AMD
1330	  processors will be enabled.
1331
1332config MICROCODE_OLD_INTERFACE
1333	def_bool y
1334	depends on MICROCODE
1335
1336config X86_MSR
1337	tristate "/dev/cpu/*/msr - Model-specific register support"
1338	---help---
1339	  This device gives privileged processes access to the x86
1340	  Model-Specific Registers (MSRs).  It is a character device with
1341	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1342	  MSR accesses are directed to a specific CPU on multi-processor
1343	  systems.
1344
1345config X86_CPUID
1346	tristate "/dev/cpu/*/cpuid - CPU information support"
1347	---help---
1348	  This device gives processes access to the x86 CPUID instruction to
1349	  be executed on a specific processor.  It is a character device
1350	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1351	  /dev/cpu/31/cpuid.
1352
1353choice
1354	prompt "High Memory Support"
1355	default HIGHMEM4G
1356	depends on X86_32
1357
1358config NOHIGHMEM
1359	bool "off"
1360	---help---
1361	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1362	  However, the address space of 32-bit x86 processors is only 4
1363	  Gigabytes large. That means that, if you have a large amount of
1364	  physical memory, not all of it can be "permanently mapped" by the
1365	  kernel. The physical memory that's not permanently mapped is called
1366	  "high memory".
1367
1368	  If you are compiling a kernel which will never run on a machine with
1369	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1370	  choice and suitable for most users). This will result in a "3GB/1GB"
1371	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1372	  space and the remaining part of the 4GB virtual memory space is used
1373	  by the kernel to permanently map as much physical memory as
1374	  possible.
1375
1376	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1377	  answer "4GB" here.
1378
1379	  If more than 4 Gigabytes is used then answer "64GB" here. This
1380	  selection turns Intel PAE (Physical Address Extension) mode on.
1381	  PAE implements 3-level paging on IA32 processors. PAE is fully
1382	  supported by Linux, PAE mode is implemented on all recent Intel
1383	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1384	  then the kernel will not boot on CPUs that don't support PAE!
1385
1386	  The actual amount of total physical memory will either be
1387	  auto detected or can be forced by using a kernel command line option
1388	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1389	  your boot loader (lilo or loadlin) about how to pass options to the
1390	  kernel at boot time.)
1391
1392	  If unsure, say "off".
1393
1394config HIGHMEM4G
1395	bool "4GB"
1396	---help---
1397	  Select this if you have a 32-bit processor and between 1 and 4
1398	  gigabytes of physical RAM.
1399
1400config HIGHMEM64G
1401	bool "64GB"
1402	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1403	select X86_PAE
1404	---help---
1405	  Select this if you have a 32-bit processor and more than 4
1406	  gigabytes of physical RAM.
1407
1408endchoice
1409
1410choice
1411	prompt "Memory split" if EXPERT
1412	default VMSPLIT_3G
1413	depends on X86_32
1414	---help---
1415	  Select the desired split between kernel and user memory.
1416
1417	  If the address range available to the kernel is less than the
1418	  physical memory installed, the remaining memory will be available
1419	  as "high memory". Accessing high memory is a little more costly
1420	  than low memory, as it needs to be mapped into the kernel first.
1421	  Note that increasing the kernel address space limits the range
1422	  available to user programs, making the address space there
1423	  tighter.  Selecting anything other than the default 3G/1G split
1424	  will also likely make your kernel incompatible with binary-only
1425	  kernel modules.
1426
1427	  If you are not absolutely sure what you are doing, leave this
1428	  option alone!
1429
1430	config VMSPLIT_3G
1431		bool "3G/1G user/kernel split"
1432	config VMSPLIT_3G_OPT
1433		depends on !X86_PAE
1434		bool "3G/1G user/kernel split (for full 1G low memory)"
1435	config VMSPLIT_2G
1436		bool "2G/2G user/kernel split"
1437	config VMSPLIT_2G_OPT
1438		depends on !X86_PAE
1439		bool "2G/2G user/kernel split (for full 2G low memory)"
1440	config VMSPLIT_1G
1441		bool "1G/3G user/kernel split"
1442endchoice
1443
1444config PAGE_OFFSET
1445	hex
1446	default 0xB0000000 if VMSPLIT_3G_OPT
1447	default 0x80000000 if VMSPLIT_2G
1448	default 0x78000000 if VMSPLIT_2G_OPT
1449	default 0x40000000 if VMSPLIT_1G
1450	default 0xC0000000
1451	depends on X86_32
1452
1453config HIGHMEM
1454	def_bool y
1455	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1456
1457config X86_PAE
1458	bool "PAE (Physical Address Extension) Support"
1459	depends on X86_32 && !HIGHMEM4G
1460	select PHYS_ADDR_T_64BIT
1461	select SWIOTLB
1462	---help---
1463	  PAE is required for NX support, and furthermore enables
1464	  larger swapspace support for non-overcommit purposes. It
1465	  has the cost of more pagetable lookup overhead, and also
1466	  consumes more pagetable space per process.
1467
1468config X86_5LEVEL
1469	bool "Enable 5-level page tables support"
1470	select DYNAMIC_MEMORY_LAYOUT
1471	select SPARSEMEM_VMEMMAP
1472	depends on X86_64
1473	---help---
1474	  5-level paging enables access to larger address space:
1475	  upto 128 PiB of virtual address space and 4 PiB of
1476	  physical address space.
1477
1478	  It will be supported by future Intel CPUs.
1479
1480	  A kernel with the option enabled can be booted on machines that
1481	  support 4- or 5-level paging.
1482
1483	  See Documentation/x86/x86_64/5level-paging.txt for more
1484	  information.
1485
1486	  Say N if unsure.
1487
1488config X86_DIRECT_GBPAGES
1489	def_bool y
1490	depends on X86_64 && !DEBUG_PAGEALLOC
1491	---help---
1492	  Certain kernel features effectively disable kernel
1493	  linear 1 GB mappings (even if the CPU otherwise
1494	  supports them), so don't confuse the user by printing
1495	  that we have them enabled.
1496
1497config ARCH_HAS_MEM_ENCRYPT
1498	def_bool y
1499
1500config AMD_MEM_ENCRYPT
1501	bool "AMD Secure Memory Encryption (SME) support"
1502	depends on X86_64 && CPU_SUP_AMD
1503	select DYNAMIC_PHYSICAL_MASK
1504	---help---
1505	  Say yes to enable support for the encryption of system memory.
1506	  This requires an AMD processor that supports Secure Memory
1507	  Encryption (SME).
1508
1509config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1510	bool "Activate AMD Secure Memory Encryption (SME) by default"
1511	default y
1512	depends on AMD_MEM_ENCRYPT
1513	---help---
1514	  Say yes to have system memory encrypted by default if running on
1515	  an AMD processor that supports Secure Memory Encryption (SME).
1516
1517	  If set to Y, then the encryption of system memory can be
1518	  deactivated with the mem_encrypt=off command line option.
1519
1520	  If set to N, then the encryption of system memory can be
1521	  activated with the mem_encrypt=on command line option.
1522
1523config ARCH_USE_MEMREMAP_PROT
1524	def_bool y
1525	depends on AMD_MEM_ENCRYPT
1526
1527# Common NUMA Features
1528config NUMA
1529	bool "Numa Memory Allocation and Scheduler Support"
1530	depends on SMP
1531	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1532	default y if X86_BIGSMP
1533	---help---
1534	  Enable NUMA (Non Uniform Memory Access) support.
1535
1536	  The kernel will try to allocate memory used by a CPU on the
1537	  local memory controller of the CPU and add some more
1538	  NUMA awareness to the kernel.
1539
1540	  For 64-bit this is recommended if the system is Intel Core i7
1541	  (or later), AMD Opteron, or EM64T NUMA.
1542
1543	  For 32-bit this is only needed if you boot a 32-bit
1544	  kernel on a 64-bit NUMA platform.
1545
1546	  Otherwise, you should say N.
1547
1548config AMD_NUMA
1549	def_bool y
1550	prompt "Old style AMD Opteron NUMA detection"
1551	depends on X86_64 && NUMA && PCI
1552	---help---
1553	  Enable AMD NUMA node topology detection.  You should say Y here if
1554	  you have a multi processor AMD system. This uses an old method to
1555	  read the NUMA configuration directly from the builtin Northbridge
1556	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1557	  which also takes priority if both are compiled in.
1558
1559config X86_64_ACPI_NUMA
1560	def_bool y
1561	prompt "ACPI NUMA detection"
1562	depends on X86_64 && NUMA && ACPI && PCI
1563	select ACPI_NUMA
1564	---help---
1565	  Enable ACPI SRAT based node topology detection.
1566
1567# Some NUMA nodes have memory ranges that span
1568# other nodes.  Even though a pfn is valid and
1569# between a node's start and end pfns, it may not
1570# reside on that node.  See memmap_init_zone()
1571# for details.
1572config NODES_SPAN_OTHER_NODES
1573	def_bool y
1574	depends on X86_64_ACPI_NUMA
1575
1576config NUMA_EMU
1577	bool "NUMA emulation"
1578	depends on NUMA
1579	---help---
1580	  Enable NUMA emulation. A flat machine will be split
1581	  into virtual nodes when booted with "numa=fake=N", where N is the
1582	  number of nodes. This is only useful for debugging.
1583
1584config NODES_SHIFT
1585	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1586	range 1 10
1587	default "10" if MAXSMP
1588	default "6" if X86_64
1589	default "3"
1590	depends on NEED_MULTIPLE_NODES
1591	---help---
1592	  Specify the maximum number of NUMA Nodes available on the target
1593	  system.  Increases memory reserved to accommodate various tables.
1594
1595config ARCH_HAVE_MEMORY_PRESENT
1596	def_bool y
1597	depends on X86_32 && DISCONTIGMEM
1598
1599config ARCH_FLATMEM_ENABLE
1600	def_bool y
1601	depends on X86_32 && !NUMA
1602
1603config ARCH_DISCONTIGMEM_ENABLE
1604	def_bool y
1605	depends on NUMA && X86_32
1606
1607config ARCH_DISCONTIGMEM_DEFAULT
1608	def_bool y
1609	depends on NUMA && X86_32
1610
1611config ARCH_SPARSEMEM_ENABLE
1612	def_bool y
1613	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1614	select SPARSEMEM_STATIC if X86_32
1615	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1616
1617config ARCH_SPARSEMEM_DEFAULT
1618	def_bool y
1619	depends on X86_64
1620
1621config ARCH_SELECT_MEMORY_MODEL
1622	def_bool y
1623	depends on ARCH_SPARSEMEM_ENABLE
1624
1625config ARCH_MEMORY_PROBE
1626	bool "Enable sysfs memory/probe interface"
1627	depends on X86_64 && MEMORY_HOTPLUG
1628	help
1629	  This option enables a sysfs memory/probe interface for testing.
1630	  See Documentation/memory-hotplug.txt for more information.
1631	  If you are unsure how to answer this question, answer N.
1632
1633config ARCH_PROC_KCORE_TEXT
1634	def_bool y
1635	depends on X86_64 && PROC_KCORE
1636
1637config ILLEGAL_POINTER_VALUE
1638       hex
1639       default 0 if X86_32
1640       default 0xdead000000000000 if X86_64
1641
1642source "mm/Kconfig"
1643
1644config X86_PMEM_LEGACY_DEVICE
1645	bool
1646
1647config X86_PMEM_LEGACY
1648	tristate "Support non-standard NVDIMMs and ADR protected memory"
1649	depends on PHYS_ADDR_T_64BIT
1650	depends on BLK_DEV
1651	select X86_PMEM_LEGACY_DEVICE
1652	select LIBNVDIMM
1653	help
1654	  Treat memory marked using the non-standard e820 type of 12 as used
1655	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1656	  The kernel will offer these regions to the 'pmem' driver so
1657	  they can be used for persistent storage.
1658
1659	  Say Y if unsure.
1660
1661config HIGHPTE
1662	bool "Allocate 3rd-level pagetables from highmem"
1663	depends on HIGHMEM
1664	---help---
1665	  The VM uses one page table entry for each page of physical memory.
1666	  For systems with a lot of RAM, this can be wasteful of precious
1667	  low memory.  Setting this option will put user-space page table
1668	  entries in high memory.
1669
1670config X86_CHECK_BIOS_CORRUPTION
1671	bool "Check for low memory corruption"
1672	---help---
1673	  Periodically check for memory corruption in low memory, which
1674	  is suspected to be caused by BIOS.  Even when enabled in the
1675	  configuration, it is disabled at runtime.  Enable it by
1676	  setting "memory_corruption_check=1" on the kernel command
1677	  line.  By default it scans the low 64k of memory every 60
1678	  seconds; see the memory_corruption_check_size and
1679	  memory_corruption_check_period parameters in
1680	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1681
1682	  When enabled with the default parameters, this option has
1683	  almost no overhead, as it reserves a relatively small amount
1684	  of memory and scans it infrequently.  It both detects corruption
1685	  and prevents it from affecting the running system.
1686
1687	  It is, however, intended as a diagnostic tool; if repeatable
1688	  BIOS-originated corruption always affects the same memory,
1689	  you can use memmap= to prevent the kernel from using that
1690	  memory.
1691
1692config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1693	bool "Set the default setting of memory_corruption_check"
1694	depends on X86_CHECK_BIOS_CORRUPTION
1695	default y
1696	---help---
1697	  Set whether the default state of memory_corruption_check is
1698	  on or off.
1699
1700config X86_RESERVE_LOW
1701	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1702	default 64
1703	range 4 640
1704	---help---
1705	  Specify the amount of low memory to reserve for the BIOS.
1706
1707	  The first page contains BIOS data structures that the kernel
1708	  must not use, so that page must always be reserved.
1709
1710	  By default we reserve the first 64K of physical RAM, as a
1711	  number of BIOSes are known to corrupt that memory range
1712	  during events such as suspend/resume or monitor cable
1713	  insertion, so it must not be used by the kernel.
1714
1715	  You can set this to 4 if you are absolutely sure that you
1716	  trust the BIOS to get all its memory reservations and usages
1717	  right.  If you know your BIOS have problems beyond the
1718	  default 64K area, you can set this to 640 to avoid using the
1719	  entire low memory range.
1720
1721	  If you have doubts about the BIOS (e.g. suspend/resume does
1722	  not work or there's kernel crashes after certain hardware
1723	  hotplug events) then you might want to enable
1724	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1725	  typical corruption patterns.
1726
1727	  Leave this to the default value of 64 if you are unsure.
1728
1729config MATH_EMULATION
1730	bool
1731	depends on MODIFY_LDT_SYSCALL
1732	prompt "Math emulation" if X86_32
1733	---help---
1734	  Linux can emulate a math coprocessor (used for floating point
1735	  operations) if you don't have one. 486DX and Pentium processors have
1736	  a math coprocessor built in, 486SX and 386 do not, unless you added
1737	  a 487DX or 387, respectively. (The messages during boot time can
1738	  give you some hints here ["man dmesg"].) Everyone needs either a
1739	  coprocessor or this emulation.
1740
1741	  If you don't have a math coprocessor, you need to say Y here; if you
1742	  say Y here even though you have a coprocessor, the coprocessor will
1743	  be used nevertheless. (This behavior can be changed with the kernel
1744	  command line option "no387", which comes handy if your coprocessor
1745	  is broken. Try "man bootparam" or see the documentation of your boot
1746	  loader (lilo or loadlin) about how to pass options to the kernel at
1747	  boot time.) This means that it is a good idea to say Y here if you
1748	  intend to use this kernel on different machines.
1749
1750	  More information about the internals of the Linux math coprocessor
1751	  emulation can be found in <file:arch/x86/math-emu/README>.
1752
1753	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1754	  kernel, it won't hurt.
1755
1756config MTRR
1757	def_bool y
1758	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1759	---help---
1760	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1761	  the Memory Type Range Registers (MTRRs) may be used to control
1762	  processor access to memory ranges. This is most useful if you have
1763	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1764	  allows bus write transfers to be combined into a larger transfer
1765	  before bursting over the PCI/AGP bus. This can increase performance
1766	  of image write operations 2.5 times or more. Saying Y here creates a
1767	  /proc/mtrr file which may be used to manipulate your processor's
1768	  MTRRs. Typically the X server should use this.
1769
1770	  This code has a reasonably generic interface so that similar
1771	  control registers on other processors can be easily supported
1772	  as well:
1773
1774	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1775	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1776	  these, the ARRs are used to emulate the MTRRs.
1777	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1778	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1779	  write-combining. All of these processors are supported by this code
1780	  and it makes sense to say Y here if you have one of them.
1781
1782	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1783	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1784	  can lead to all sorts of problems, so it's good to say Y here.
1785
1786	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1787	  just add about 9 KB to your kernel.
1788
1789	  See <file:Documentation/x86/mtrr.txt> for more information.
1790
1791config MTRR_SANITIZER
1792	def_bool y
1793	prompt "MTRR cleanup support"
1794	depends on MTRR
1795	---help---
1796	  Convert MTRR layout from continuous to discrete, so X drivers can
1797	  add writeback entries.
1798
1799	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1800	  The largest mtrr entry size for a continuous block can be set with
1801	  mtrr_chunk_size.
1802
1803	  If unsure, say Y.
1804
1805config MTRR_SANITIZER_ENABLE_DEFAULT
1806	int "MTRR cleanup enable value (0-1)"
1807	range 0 1
1808	default "0"
1809	depends on MTRR_SANITIZER
1810	---help---
1811	  Enable mtrr cleanup default value
1812
1813config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1814	int "MTRR cleanup spare reg num (0-7)"
1815	range 0 7
1816	default "1"
1817	depends on MTRR_SANITIZER
1818	---help---
1819	  mtrr cleanup spare entries default, it can be changed via
1820	  mtrr_spare_reg_nr=N on the kernel command line.
1821
1822config X86_PAT
1823	def_bool y
1824	prompt "x86 PAT support" if EXPERT
1825	depends on MTRR
1826	---help---
1827	  Use PAT attributes to setup page level cache control.
1828
1829	  PATs are the modern equivalents of MTRRs and are much more
1830	  flexible than MTRRs.
1831
1832	  Say N here if you see bootup problems (boot crash, boot hang,
1833	  spontaneous reboots) or a non-working video driver.
1834
1835	  If unsure, say Y.
1836
1837config ARCH_USES_PG_UNCACHED
1838	def_bool y
1839	depends on X86_PAT
1840
1841config ARCH_RANDOM
1842	def_bool y
1843	prompt "x86 architectural random number generator" if EXPERT
1844	---help---
1845	  Enable the x86 architectural RDRAND instruction
1846	  (Intel Bull Mountain technology) to generate random numbers.
1847	  If supported, this is a high bandwidth, cryptographically
1848	  secure hardware random number generator.
1849
1850config X86_SMAP
1851	def_bool y
1852	prompt "Supervisor Mode Access Prevention" if EXPERT
1853	---help---
1854	  Supervisor Mode Access Prevention (SMAP) is a security
1855	  feature in newer Intel processors.  There is a small
1856	  performance cost if this enabled and turned on; there is
1857	  also a small increase in the kernel size if this is enabled.
1858
1859	  If unsure, say Y.
1860
1861config X86_INTEL_UMIP
1862	def_bool y
1863	depends on CPU_SUP_INTEL
1864	prompt "Intel User Mode Instruction Prevention" if EXPERT
1865	---help---
1866	  The User Mode Instruction Prevention (UMIP) is a security
1867	  feature in newer Intel processors. If enabled, a general
1868	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1869	  or STR instructions are executed in user mode. These instructions
1870	  unnecessarily expose information about the hardware state.
1871
1872	  The vast majority of applications do not use these instructions.
1873	  For the very few that do, software emulation is provided in
1874	  specific cases in protected and virtual-8086 modes. Emulated
1875	  results are dummy.
1876
1877config X86_INTEL_MPX
1878	prompt "Intel MPX (Memory Protection Extensions)"
1879	def_bool n
1880	# Note: only available in 64-bit mode due to VMA flags shortage
1881	depends on CPU_SUP_INTEL && X86_64
1882	select ARCH_USES_HIGH_VMA_FLAGS
1883	---help---
1884	  MPX provides hardware features that can be used in
1885	  conjunction with compiler-instrumented code to check
1886	  memory references.  It is designed to detect buffer
1887	  overflow or underflow bugs.
1888
1889	  This option enables running applications which are
1890	  instrumented or otherwise use MPX.  It does not use MPX
1891	  itself inside the kernel or to protect the kernel
1892	  against bad memory references.
1893
1894	  Enabling this option will make the kernel larger:
1895	  ~8k of kernel text and 36 bytes of data on a 64-bit
1896	  defconfig.  It adds a long to the 'mm_struct' which
1897	  will increase the kernel memory overhead of each
1898	  process and adds some branches to paths used during
1899	  exec() and munmap().
1900
1901	  For details, see Documentation/x86/intel_mpx.txt
1902
1903	  If unsure, say N.
1904
1905config X86_INTEL_MEMORY_PROTECTION_KEYS
1906	prompt "Intel Memory Protection Keys"
1907	def_bool y
1908	# Note: only available in 64-bit mode
1909	depends on CPU_SUP_INTEL && X86_64
1910	select ARCH_USES_HIGH_VMA_FLAGS
1911	select ARCH_HAS_PKEYS
1912	---help---
1913	  Memory Protection Keys provides a mechanism for enforcing
1914	  page-based protections, but without requiring modification of the
1915	  page tables when an application changes protection domains.
1916
1917	  For details, see Documentation/x86/protection-keys.txt
1918
1919	  If unsure, say y.
1920
1921config EFI
1922	bool "EFI runtime service support"
1923	depends on ACPI
1924	select UCS2_STRING
1925	select EFI_RUNTIME_WRAPPERS
1926	---help---
1927	  This enables the kernel to use EFI runtime services that are
1928	  available (such as the EFI variable services).
1929
1930	  This option is only useful on systems that have EFI firmware.
1931	  In addition, you should use the latest ELILO loader available
1932	  at <http://elilo.sourceforge.net> in order to take advantage
1933	  of EFI runtime services. However, even with this option, the
1934	  resultant kernel should continue to boot on existing non-EFI
1935	  platforms.
1936
1937config EFI_STUB
1938       bool "EFI stub support"
1939       depends on EFI && !X86_USE_3DNOW
1940       select RELOCATABLE
1941       ---help---
1942          This kernel feature allows a bzImage to be loaded directly
1943	  by EFI firmware without the use of a bootloader.
1944
1945	  See Documentation/efi-stub.txt for more information.
1946
1947config EFI_MIXED
1948	bool "EFI mixed-mode support"
1949	depends on EFI_STUB && X86_64
1950	---help---
1951	   Enabling this feature allows a 64-bit kernel to be booted
1952	   on a 32-bit firmware, provided that your CPU supports 64-bit
1953	   mode.
1954
1955	   Note that it is not possible to boot a mixed-mode enabled
1956	   kernel via the EFI boot stub - a bootloader that supports
1957	   the EFI handover protocol must be used.
1958
1959	   If unsure, say N.
1960
1961config SECCOMP
1962	def_bool y
1963	prompt "Enable seccomp to safely compute untrusted bytecode"
1964	---help---
1965	  This kernel feature is useful for number crunching applications
1966	  that may need to compute untrusted bytecode during their
1967	  execution. By using pipes or other transports made available to
1968	  the process as file descriptors supporting the read/write
1969	  syscalls, it's possible to isolate those applications in
1970	  their own address space using seccomp. Once seccomp is
1971	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1972	  and the task is only allowed to execute a few safe syscalls
1973	  defined by each seccomp mode.
1974
1975	  If unsure, say Y. Only embedded should say N here.
1976
1977source kernel/Kconfig.hz
1978
1979config KEXEC
1980	bool "kexec system call"
1981	select KEXEC_CORE
1982	---help---
1983	  kexec is a system call that implements the ability to shutdown your
1984	  current kernel, and to start another kernel.  It is like a reboot
1985	  but it is independent of the system firmware.   And like a reboot
1986	  you can start any kernel with it, not just Linux.
1987
1988	  The name comes from the similarity to the exec system call.
1989
1990	  It is an ongoing process to be certain the hardware in a machine
1991	  is properly shutdown, so do not be surprised if this code does not
1992	  initially work for you.  As of this writing the exact hardware
1993	  interface is strongly in flux, so no good recommendation can be
1994	  made.
1995
1996config KEXEC_FILE
1997	bool "kexec file based system call"
1998	select KEXEC_CORE
1999	select BUILD_BIN2C
2000	depends on X86_64
2001	depends on CRYPTO=y
2002	depends on CRYPTO_SHA256=y
2003	---help---
2004	  This is new version of kexec system call. This system call is
2005	  file based and takes file descriptors as system call argument
2006	  for kernel and initramfs as opposed to list of segments as
2007	  accepted by previous system call.
2008
2009config ARCH_HAS_KEXEC_PURGATORY
2010	def_bool KEXEC_FILE
2011
2012config KEXEC_VERIFY_SIG
2013	bool "Verify kernel signature during kexec_file_load() syscall"
2014	depends on KEXEC_FILE
2015	---help---
2016	  This option makes kernel signature verification mandatory for
2017	  the kexec_file_load() syscall.
2018
2019	  In addition to that option, you need to enable signature
2020	  verification for the corresponding kernel image type being
2021	  loaded in order for this to work.
2022
2023config KEXEC_BZIMAGE_VERIFY_SIG
2024	bool "Enable bzImage signature verification support"
2025	depends on KEXEC_VERIFY_SIG
2026	depends on SIGNED_PE_FILE_VERIFICATION
2027	select SYSTEM_TRUSTED_KEYRING
2028	---help---
2029	  Enable bzImage signature verification support.
2030
2031config CRASH_DUMP
2032	bool "kernel crash dumps"
2033	depends on X86_64 || (X86_32 && HIGHMEM)
2034	---help---
2035	  Generate crash dump after being started by kexec.
2036	  This should be normally only set in special crash dump kernels
2037	  which are loaded in the main kernel with kexec-tools into
2038	  a specially reserved region and then later executed after
2039	  a crash by kdump/kexec. The crash dump kernel must be compiled
2040	  to a memory address not used by the main kernel or BIOS using
2041	  PHYSICAL_START, or it must be built as a relocatable image
2042	  (CONFIG_RELOCATABLE=y).
2043	  For more details see Documentation/kdump/kdump.txt
2044
2045config KEXEC_JUMP
2046	bool "kexec jump"
2047	depends on KEXEC && HIBERNATION
2048	---help---
2049	  Jump between original kernel and kexeced kernel and invoke
2050	  code in physical address mode via KEXEC
2051
2052config PHYSICAL_START
2053	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2054	default "0x1000000"
2055	---help---
2056	  This gives the physical address where the kernel is loaded.
2057
2058	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2059	  bzImage will decompress itself to above physical address and
2060	  run from there. Otherwise, bzImage will run from the address where
2061	  it has been loaded by the boot loader and will ignore above physical
2062	  address.
2063
2064	  In normal kdump cases one does not have to set/change this option
2065	  as now bzImage can be compiled as a completely relocatable image
2066	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2067	  address. This option is mainly useful for the folks who don't want
2068	  to use a bzImage for capturing the crash dump and want to use a
2069	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2070	  to be specifically compiled to run from a specific memory area
2071	  (normally a reserved region) and this option comes handy.
2072
2073	  So if you are using bzImage for capturing the crash dump,
2074	  leave the value here unchanged to 0x1000000 and set
2075	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2076	  for capturing the crash dump change this value to start of
2077	  the reserved region.  In other words, it can be set based on
2078	  the "X" value as specified in the "crashkernel=YM@XM"
2079	  command line boot parameter passed to the panic-ed
2080	  kernel. Please take a look at Documentation/kdump/kdump.txt
2081	  for more details about crash dumps.
2082
2083	  Usage of bzImage for capturing the crash dump is recommended as
2084	  one does not have to build two kernels. Same kernel can be used
2085	  as production kernel and capture kernel. Above option should have
2086	  gone away after relocatable bzImage support is introduced. But it
2087	  is present because there are users out there who continue to use
2088	  vmlinux for dump capture. This option should go away down the
2089	  line.
2090
2091	  Don't change this unless you know what you are doing.
2092
2093config RELOCATABLE
2094	bool "Build a relocatable kernel"
2095	default y
2096	---help---
2097	  This builds a kernel image that retains relocation information
2098	  so it can be loaded someplace besides the default 1MB.
2099	  The relocations tend to make the kernel binary about 10% larger,
2100	  but are discarded at runtime.
2101
2102	  One use is for the kexec on panic case where the recovery kernel
2103	  must live at a different physical address than the primary
2104	  kernel.
2105
2106	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2107	  it has been loaded at and the compile time physical address
2108	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2109
2110config RANDOMIZE_BASE
2111	bool "Randomize the address of the kernel image (KASLR)"
2112	depends on RELOCATABLE
2113	default y
2114	---help---
2115	  In support of Kernel Address Space Layout Randomization (KASLR),
2116	  this randomizes the physical address at which the kernel image
2117	  is decompressed and the virtual address where the kernel
2118	  image is mapped, as a security feature that deters exploit
2119	  attempts relying on knowledge of the location of kernel
2120	  code internals.
2121
2122	  On 64-bit, the kernel physical and virtual addresses are
2123	  randomized separately. The physical address will be anywhere
2124	  between 16MB and the top of physical memory (up to 64TB). The
2125	  virtual address will be randomized from 16MB up to 1GB (9 bits
2126	  of entropy). Note that this also reduces the memory space
2127	  available to kernel modules from 1.5GB to 1GB.
2128
2129	  On 32-bit, the kernel physical and virtual addresses are
2130	  randomized together. They will be randomized from 16MB up to
2131	  512MB (8 bits of entropy).
2132
2133	  Entropy is generated using the RDRAND instruction if it is
2134	  supported. If RDTSC is supported, its value is mixed into
2135	  the entropy pool as well. If neither RDRAND nor RDTSC are
2136	  supported, then entropy is read from the i8254 timer. The
2137	  usable entropy is limited by the kernel being built using
2138	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2139	  minimum of 2MB. As a result, only 10 bits of entropy are
2140	  theoretically possible, but the implementations are further
2141	  limited due to memory layouts.
2142
2143	  If unsure, say Y.
2144
2145# Relocation on x86 needs some additional build support
2146config X86_NEED_RELOCS
2147	def_bool y
2148	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2149
2150config PHYSICAL_ALIGN
2151	hex "Alignment value to which kernel should be aligned"
2152	default "0x200000"
2153	range 0x2000 0x1000000 if X86_32
2154	range 0x200000 0x1000000 if X86_64
2155	---help---
2156	  This value puts the alignment restrictions on physical address
2157	  where kernel is loaded and run from. Kernel is compiled for an
2158	  address which meets above alignment restriction.
2159
2160	  If bootloader loads the kernel at a non-aligned address and
2161	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2162	  address aligned to above value and run from there.
2163
2164	  If bootloader loads the kernel at a non-aligned address and
2165	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2166	  load address and decompress itself to the address it has been
2167	  compiled for and run from there. The address for which kernel is
2168	  compiled already meets above alignment restrictions. Hence the
2169	  end result is that kernel runs from a physical address meeting
2170	  above alignment restrictions.
2171
2172	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2173	  this value must be a multiple of 0x200000.
2174
2175	  Don't change this unless you know what you are doing.
2176
2177config DYNAMIC_MEMORY_LAYOUT
2178	bool
2179	---help---
2180	  This option makes base addresses of vmalloc and vmemmap as well as
2181	  __PAGE_OFFSET movable during boot.
2182
2183config RANDOMIZE_MEMORY
2184	bool "Randomize the kernel memory sections"
2185	depends on X86_64
2186	depends on RANDOMIZE_BASE
2187	select DYNAMIC_MEMORY_LAYOUT
2188	default RANDOMIZE_BASE
2189	---help---
2190	   Randomizes the base virtual address of kernel memory sections
2191	   (physical memory mapping, vmalloc & vmemmap). This security feature
2192	   makes exploits relying on predictable memory locations less reliable.
2193
2194	   The order of allocations remains unchanged. Entropy is generated in
2195	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2196	   configuration have in average 30,000 different possible virtual
2197	   addresses for each memory section.
2198
2199	   If unsure, say Y.
2200
2201config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2202	hex "Physical memory mapping padding" if EXPERT
2203	depends on RANDOMIZE_MEMORY
2204	default "0xa" if MEMORY_HOTPLUG
2205	default "0x0"
2206	range 0x1 0x40 if MEMORY_HOTPLUG
2207	range 0x0 0x40
2208	---help---
2209	   Define the padding in terabytes added to the existing physical
2210	   memory size during kernel memory randomization. It is useful
2211	   for memory hotplug support but reduces the entropy available for
2212	   address randomization.
2213
2214	   If unsure, leave at the default value.
2215
2216config HOTPLUG_CPU
2217	bool "Support for hot-pluggable CPUs"
2218	depends on SMP
2219	---help---
2220	  Say Y here to allow turning CPUs off and on. CPUs can be
2221	  controlled through /sys/devices/system/cpu.
2222	  ( Note: power management support will enable this option
2223	    automatically on SMP systems. )
2224	  Say N if you want to disable CPU hotplug.
2225
2226config BOOTPARAM_HOTPLUG_CPU0
2227	bool "Set default setting of cpu0_hotpluggable"
2228	default n
2229	depends on HOTPLUG_CPU
2230	---help---
2231	  Set whether default state of cpu0_hotpluggable is on or off.
2232
2233	  Say Y here to enable CPU0 hotplug by default. If this switch
2234	  is turned on, there is no need to give cpu0_hotplug kernel
2235	  parameter and the CPU0 hotplug feature is enabled by default.
2236
2237	  Please note: there are two known CPU0 dependencies if you want
2238	  to enable the CPU0 hotplug feature either by this switch or by
2239	  cpu0_hotplug kernel parameter.
2240
2241	  First, resume from hibernate or suspend always starts from CPU0.
2242	  So hibernate and suspend are prevented if CPU0 is offline.
2243
2244	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2245	  offline if any interrupt can not migrate out of CPU0. There may
2246	  be other CPU0 dependencies.
2247
2248	  Please make sure the dependencies are under your control before
2249	  you enable this feature.
2250
2251	  Say N if you don't want to enable CPU0 hotplug feature by default.
2252	  You still can enable the CPU0 hotplug feature at boot by kernel
2253	  parameter cpu0_hotplug.
2254
2255config DEBUG_HOTPLUG_CPU0
2256	def_bool n
2257	prompt "Debug CPU0 hotplug"
2258	depends on HOTPLUG_CPU
2259	---help---
2260	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2261	  soon as possible and boots up userspace with CPU0 offlined. User
2262	  can online CPU0 back after boot time.
2263
2264	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2265	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2266	  compilation or giving cpu0_hotplug kernel parameter at boot.
2267
2268	  If unsure, say N.
2269
2270config COMPAT_VDSO
2271	def_bool n
2272	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2273	depends on COMPAT_32
2274	---help---
2275	  Certain buggy versions of glibc will crash if they are
2276	  presented with a 32-bit vDSO that is not mapped at the address
2277	  indicated in its segment table.
2278
2279	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2280	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2281	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2282	  the only released version with the bug, but OpenSUSE 9
2283	  contains a buggy "glibc 2.3.2".
2284
2285	  The symptom of the bug is that everything crashes on startup, saying:
2286	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2287
2288	  Saying Y here changes the default value of the vdso32 boot
2289	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2290	  This works around the glibc bug but hurts performance.
2291
2292	  If unsure, say N: if you are compiling your own kernel, you
2293	  are unlikely to be using a buggy version of glibc.
2294
2295choice
2296	prompt "vsyscall table for legacy applications"
2297	depends on X86_64
2298	default LEGACY_VSYSCALL_EMULATE
2299	help
2300	  Legacy user code that does not know how to find the vDSO expects
2301	  to be able to issue three syscalls by calling fixed addresses in
2302	  kernel space. Since this location is not randomized with ASLR,
2303	  it can be used to assist security vulnerability exploitation.
2304
2305	  This setting can be changed at boot time via the kernel command
2306	  line parameter vsyscall=[emulate|none].
2307
2308	  On a system with recent enough glibc (2.14 or newer) and no
2309	  static binaries, you can say None without a performance penalty
2310	  to improve security.
2311
2312	  If unsure, select "Emulate".
2313
2314	config LEGACY_VSYSCALL_EMULATE
2315		bool "Emulate"
2316		help
2317		  The kernel traps and emulates calls into the fixed
2318		  vsyscall address mapping. This makes the mapping
2319		  non-executable, but it still contains known contents,
2320		  which could be used in certain rare security vulnerability
2321		  exploits. This configuration is recommended when userspace
2322		  still uses the vsyscall area.
2323
2324	config LEGACY_VSYSCALL_NONE
2325		bool "None"
2326		help
2327		  There will be no vsyscall mapping at all. This will
2328		  eliminate any risk of ASLR bypass due to the vsyscall
2329		  fixed address mapping. Attempts to use the vsyscalls
2330		  will be reported to dmesg, so that either old or
2331		  malicious userspace programs can be identified.
2332
2333endchoice
2334
2335config CMDLINE_BOOL
2336	bool "Built-in kernel command line"
2337	---help---
2338	  Allow for specifying boot arguments to the kernel at
2339	  build time.  On some systems (e.g. embedded ones), it is
2340	  necessary or convenient to provide some or all of the
2341	  kernel boot arguments with the kernel itself (that is,
2342	  to not rely on the boot loader to provide them.)
2343
2344	  To compile command line arguments into the kernel,
2345	  set this option to 'Y', then fill in the
2346	  boot arguments in CONFIG_CMDLINE.
2347
2348	  Systems with fully functional boot loaders (i.e. non-embedded)
2349	  should leave this option set to 'N'.
2350
2351config CMDLINE
2352	string "Built-in kernel command string"
2353	depends on CMDLINE_BOOL
2354	default ""
2355	---help---
2356	  Enter arguments here that should be compiled into the kernel
2357	  image and used at boot time.  If the boot loader provides a
2358	  command line at boot time, it is appended to this string to
2359	  form the full kernel command line, when the system boots.
2360
2361	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2362	  change this behavior.
2363
2364	  In most cases, the command line (whether built-in or provided
2365	  by the boot loader) should specify the device for the root
2366	  file system.
2367
2368config CMDLINE_OVERRIDE
2369	bool "Built-in command line overrides boot loader arguments"
2370	depends on CMDLINE_BOOL
2371	---help---
2372	  Set this option to 'Y' to have the kernel ignore the boot loader
2373	  command line, and use ONLY the built-in command line.
2374
2375	  This is used to work around broken boot loaders.  This should
2376	  be set to 'N' under normal conditions.
2377
2378config MODIFY_LDT_SYSCALL
2379	bool "Enable the LDT (local descriptor table)" if EXPERT
2380	default y
2381	---help---
2382	  Linux can allow user programs to install a per-process x86
2383	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2384	  call.  This is required to run 16-bit or segmented code such as
2385	  DOSEMU or some Wine programs.  It is also used by some very old
2386	  threading libraries.
2387
2388	  Enabling this feature adds a small amount of overhead to
2389	  context switches and increases the low-level kernel attack
2390	  surface.  Disabling it removes the modify_ldt(2) system call.
2391
2392	  Saying 'N' here may make sense for embedded or server kernels.
2393
2394source "kernel/livepatch/Kconfig"
2395
2396endmenu
2397
2398config ARCH_HAS_ADD_PAGES
2399	def_bool y
2400	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2401
2402config ARCH_ENABLE_MEMORY_HOTPLUG
2403	def_bool y
2404	depends on X86_64 || (X86_32 && HIGHMEM)
2405
2406config ARCH_ENABLE_MEMORY_HOTREMOVE
2407	def_bool y
2408	depends on MEMORY_HOTPLUG
2409
2410config USE_PERCPU_NUMA_NODE_ID
2411	def_bool y
2412	depends on NUMA
2413
2414config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2415	def_bool y
2416	depends on X86_64 || X86_PAE
2417
2418config ARCH_ENABLE_HUGEPAGE_MIGRATION
2419	def_bool y
2420	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2421
2422config ARCH_ENABLE_THP_MIGRATION
2423	def_bool y
2424	depends on X86_64 && TRANSPARENT_HUGEPAGE
2425
2426menu "Power management and ACPI options"
2427
2428config ARCH_HIBERNATION_HEADER
2429	def_bool y
2430	depends on X86_64 && HIBERNATION
2431
2432source "kernel/power/Kconfig"
2433
2434source "drivers/acpi/Kconfig"
2435
2436source "drivers/sfi/Kconfig"
2437
2438config X86_APM_BOOT
2439	def_bool y
2440	depends on APM
2441
2442menuconfig APM
2443	tristate "APM (Advanced Power Management) BIOS support"
2444	depends on X86_32 && PM_SLEEP
2445	---help---
2446	  APM is a BIOS specification for saving power using several different
2447	  techniques. This is mostly useful for battery powered laptops with
2448	  APM compliant BIOSes. If you say Y here, the system time will be
2449	  reset after a RESUME operation, the /proc/apm device will provide
2450	  battery status information, and user-space programs will receive
2451	  notification of APM "events" (e.g. battery status change).
2452
2453	  If you select "Y" here, you can disable actual use of the APM
2454	  BIOS by passing the "apm=off" option to the kernel at boot time.
2455
2456	  Note that the APM support is almost completely disabled for
2457	  machines with more than one CPU.
2458
2459	  In order to use APM, you will need supporting software. For location
2460	  and more information, read <file:Documentation/power/apm-acpi.txt>
2461	  and the Battery Powered Linux mini-HOWTO, available from
2462	  <http://www.tldp.org/docs.html#howto>.
2463
2464	  This driver does not spin down disk drives (see the hdparm(8)
2465	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2466	  VESA-compliant "green" monitors.
2467
2468	  This driver does not support the TI 4000M TravelMate and the ACER
2469	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2470	  desktop machines also don't have compliant BIOSes, and this driver
2471	  may cause those machines to panic during the boot phase.
2472
2473	  Generally, if you don't have a battery in your machine, there isn't
2474	  much point in using this driver and you should say N. If you get
2475	  random kernel OOPSes or reboots that don't seem to be related to
2476	  anything, try disabling/enabling this option (or disabling/enabling
2477	  APM in your BIOS).
2478
2479	  Some other things you should try when experiencing seemingly random,
2480	  "weird" problems:
2481
2482	  1) make sure that you have enough swap space and that it is
2483	  enabled.
2484	  2) pass the "no-hlt" option to the kernel
2485	  3) switch on floating point emulation in the kernel and pass
2486	  the "no387" option to the kernel
2487	  4) pass the "floppy=nodma" option to the kernel
2488	  5) pass the "mem=4M" option to the kernel (thereby disabling
2489	  all but the first 4 MB of RAM)
2490	  6) make sure that the CPU is not over clocked.
2491	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2492	  8) disable the cache from your BIOS settings
2493	  9) install a fan for the video card or exchange video RAM
2494	  10) install a better fan for the CPU
2495	  11) exchange RAM chips
2496	  12) exchange the motherboard.
2497
2498	  To compile this driver as a module, choose M here: the
2499	  module will be called apm.
2500
2501if APM
2502
2503config APM_IGNORE_USER_SUSPEND
2504	bool "Ignore USER SUSPEND"
2505	---help---
2506	  This option will ignore USER SUSPEND requests. On machines with a
2507	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2508	  series notebooks, it is necessary to say Y because of a BIOS bug.
2509
2510config APM_DO_ENABLE
2511	bool "Enable PM at boot time"
2512	---help---
2513	  Enable APM features at boot time. From page 36 of the APM BIOS
2514	  specification: "When disabled, the APM BIOS does not automatically
2515	  power manage devices, enter the Standby State, enter the Suspend
2516	  State, or take power saving steps in response to CPU Idle calls."
2517	  This driver will make CPU Idle calls when Linux is idle (unless this
2518	  feature is turned off -- see "Do CPU IDLE calls", below). This
2519	  should always save battery power, but more complicated APM features
2520	  will be dependent on your BIOS implementation. You may need to turn
2521	  this option off if your computer hangs at boot time when using APM
2522	  support, or if it beeps continuously instead of suspending. Turn
2523	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2524	  T400CDT. This is off by default since most machines do fine without
2525	  this feature.
2526
2527config APM_CPU_IDLE
2528	depends on CPU_IDLE
2529	bool "Make CPU Idle calls when idle"
2530	---help---
2531	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2532	  On some machines, this can activate improved power savings, such as
2533	  a slowed CPU clock rate, when the machine is idle. These idle calls
2534	  are made after the idle loop has run for some length of time (e.g.,
2535	  333 mS). On some machines, this will cause a hang at boot time or
2536	  whenever the CPU becomes idle. (On machines with more than one CPU,
2537	  this option does nothing.)
2538
2539config APM_DISPLAY_BLANK
2540	bool "Enable console blanking using APM"
2541	---help---
2542	  Enable console blanking using the APM. Some laptops can use this to
2543	  turn off the LCD backlight when the screen blanker of the Linux
2544	  virtual console blanks the screen. Note that this is only used by
2545	  the virtual console screen blanker, and won't turn off the backlight
2546	  when using the X Window system. This also doesn't have anything to
2547	  do with your VESA-compliant power-saving monitor. Further, this
2548	  option doesn't work for all laptops -- it might not turn off your
2549	  backlight at all, or it might print a lot of errors to the console,
2550	  especially if you are using gpm.
2551
2552config APM_ALLOW_INTS
2553	bool "Allow interrupts during APM BIOS calls"
2554	---help---
2555	  Normally we disable external interrupts while we are making calls to
2556	  the APM BIOS as a measure to lessen the effects of a badly behaving
2557	  BIOS implementation.  The BIOS should reenable interrupts if it
2558	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2559	  many of the newer IBM Thinkpads.  If you experience hangs when you
2560	  suspend, try setting this to Y.  Otherwise, say N.
2561
2562endif # APM
2563
2564source "drivers/cpufreq/Kconfig"
2565
2566source "drivers/cpuidle/Kconfig"
2567
2568source "drivers/idle/Kconfig"
2569
2570endmenu
2571
2572
2573menu "Bus options (PCI etc.)"
2574
2575config PCI
2576	bool "PCI support"
2577	default y
2578	---help---
2579	  Find out whether you have a PCI motherboard. PCI is the name of a
2580	  bus system, i.e. the way the CPU talks to the other stuff inside
2581	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2582	  VESA. If you have PCI, say Y, otherwise N.
2583
2584choice
2585	prompt "PCI access mode"
2586	depends on X86_32 && PCI
2587	default PCI_GOANY
2588	---help---
2589	  On PCI systems, the BIOS can be used to detect the PCI devices and
2590	  determine their configuration. However, some old PCI motherboards
2591	  have BIOS bugs and may crash if this is done. Also, some embedded
2592	  PCI-based systems don't have any BIOS at all. Linux can also try to
2593	  detect the PCI hardware directly without using the BIOS.
2594
2595	  With this option, you can specify how Linux should detect the
2596	  PCI devices. If you choose "BIOS", the BIOS will be used,
2597	  if you choose "Direct", the BIOS won't be used, and if you
2598	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2599	  If you choose "Any", the kernel will try MMCONFIG, then the
2600	  direct access method and falls back to the BIOS if that doesn't
2601	  work. If unsure, go with the default, which is "Any".
2602
2603config PCI_GOBIOS
2604	bool "BIOS"
2605
2606config PCI_GOMMCONFIG
2607	bool "MMConfig"
2608
2609config PCI_GODIRECT
2610	bool "Direct"
2611
2612config PCI_GOOLPC
2613	bool "OLPC XO-1"
2614	depends on OLPC
2615
2616config PCI_GOANY
2617	bool "Any"
2618
2619endchoice
2620
2621config PCI_BIOS
2622	def_bool y
2623	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2624
2625# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2626config PCI_DIRECT
2627	def_bool y
2628	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2629
2630config PCI_MMCONFIG
2631	bool "Support mmconfig PCI config space access" if X86_64
2632	default y
2633	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2634	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2635
2636config PCI_OLPC
2637	def_bool y
2638	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2639
2640config PCI_XEN
2641	def_bool y
2642	depends on PCI && XEN
2643	select SWIOTLB_XEN
2644
2645config PCI_DOMAINS
2646	def_bool y
2647	depends on PCI
2648
2649config MMCONF_FAM10H
2650	def_bool y
2651	depends on X86_64 && PCI_MMCONFIG && ACPI
2652
2653config PCI_CNB20LE_QUIRK
2654	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2655	depends on PCI
2656	help
2657	  Read the PCI windows out of the CNB20LE host bridge. This allows
2658	  PCI hotplug to work on systems with the CNB20LE chipset which do
2659	  not have ACPI.
2660
2661	  There's no public spec for this chipset, and this functionality
2662	  is known to be incomplete.
2663
2664	  You should say N unless you know you need this.
2665
2666source "drivers/pci/Kconfig"
2667
2668config ISA_BUS
2669	bool "ISA bus support on modern systems" if EXPERT
2670	help
2671	  Expose ISA bus device drivers and options available for selection and
2672	  configuration. Enable this option if your target machine has an ISA
2673	  bus. ISA is an older system, displaced by PCI and newer bus
2674	  architectures -- if your target machine is modern, it probably does
2675	  not have an ISA bus.
2676
2677	  If unsure, say N.
2678
2679# x86_64 have no ISA slots, but can have ISA-style DMA.
2680config ISA_DMA_API
2681	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2682	default y
2683	help
2684	  Enables ISA-style DMA support for devices requiring such controllers.
2685	  If unsure, say Y.
2686
2687if X86_32
2688
2689config ISA
2690	bool "ISA support"
2691	---help---
2692	  Find out whether you have ISA slots on your motherboard.  ISA is the
2693	  name of a bus system, i.e. the way the CPU talks to the other stuff
2694	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2695	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2696	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2697
2698config EISA
2699	bool "EISA support"
2700	depends on ISA
2701	---help---
2702	  The Extended Industry Standard Architecture (EISA) bus was
2703	  developed as an open alternative to the IBM MicroChannel bus.
2704
2705	  The EISA bus provided some of the features of the IBM MicroChannel
2706	  bus while maintaining backward compatibility with cards made for
2707	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2708	  1995 when it was made obsolete by the PCI bus.
2709
2710	  Say Y here if you are building a kernel for an EISA-based machine.
2711
2712	  Otherwise, say N.
2713
2714source "drivers/eisa/Kconfig"
2715
2716config SCx200
2717	tristate "NatSemi SCx200 support"
2718	---help---
2719	  This provides basic support for National Semiconductor's
2720	  (now AMD's) Geode processors.  The driver probes for the
2721	  PCI-IDs of several on-chip devices, so its a good dependency
2722	  for other scx200_* drivers.
2723
2724	  If compiled as a module, the driver is named scx200.
2725
2726config SCx200HR_TIMER
2727	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2728	depends on SCx200
2729	default y
2730	---help---
2731	  This driver provides a clocksource built upon the on-chip
2732	  27MHz high-resolution timer.  Its also a workaround for
2733	  NSC Geode SC-1100's buggy TSC, which loses time when the
2734	  processor goes idle (as is done by the scheduler).  The
2735	  other workaround is idle=poll boot option.
2736
2737config OLPC
2738	bool "One Laptop Per Child support"
2739	depends on !X86_PAE
2740	select GPIOLIB
2741	select OF
2742	select OF_PROMTREE
2743	select IRQ_DOMAIN
2744	---help---
2745	  Add support for detecting the unique features of the OLPC
2746	  XO hardware.
2747
2748config OLPC_XO1_PM
2749	bool "OLPC XO-1 Power Management"
2750	depends on OLPC && MFD_CS5535 && PM_SLEEP
2751	select MFD_CORE
2752	---help---
2753	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2754
2755config OLPC_XO1_RTC
2756	bool "OLPC XO-1 Real Time Clock"
2757	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2758	---help---
2759	  Add support for the XO-1 real time clock, which can be used as a
2760	  programmable wakeup source.
2761
2762config OLPC_XO1_SCI
2763	bool "OLPC XO-1 SCI extras"
2764	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2765	depends on INPUT=y
2766	select POWER_SUPPLY
2767	---help---
2768	  Add support for SCI-based features of the OLPC XO-1 laptop:
2769	   - EC-driven system wakeups
2770	   - Power button
2771	   - Ebook switch
2772	   - Lid switch
2773	   - AC adapter status updates
2774	   - Battery status updates
2775
2776config OLPC_XO15_SCI
2777	bool "OLPC XO-1.5 SCI extras"
2778	depends on OLPC && ACPI
2779	select POWER_SUPPLY
2780	---help---
2781	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2782	   - EC-driven system wakeups
2783	   - AC adapter status updates
2784	   - Battery status updates
2785
2786config ALIX
2787	bool "PCEngines ALIX System Support (LED setup)"
2788	select GPIOLIB
2789	---help---
2790	  This option enables system support for the PCEngines ALIX.
2791	  At present this just sets up LEDs for GPIO control on
2792	  ALIX2/3/6 boards.  However, other system specific setup should
2793	  get added here.
2794
2795	  Note: You must still enable the drivers for GPIO and LED support
2796	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2797
2798	  Note: You have to set alix.force=1 for boards with Award BIOS.
2799
2800config NET5501
2801	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2802	select GPIOLIB
2803	---help---
2804	  This option enables system support for the Soekris Engineering net5501.
2805
2806config GEOS
2807	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2808	select GPIOLIB
2809	depends on DMI
2810	---help---
2811	  This option enables system support for the Traverse Technologies GEOS.
2812
2813config TS5500
2814	bool "Technologic Systems TS-5500 platform support"
2815	depends on MELAN
2816	select CHECK_SIGNATURE
2817	select NEW_LEDS
2818	select LEDS_CLASS
2819	---help---
2820	  This option enables system support for the Technologic Systems TS-5500.
2821
2822endif # X86_32
2823
2824config AMD_NB
2825	def_bool y
2826	depends on CPU_SUP_AMD && PCI
2827
2828source "drivers/pcmcia/Kconfig"
2829
2830config RAPIDIO
2831	tristate "RapidIO support"
2832	depends on PCI
2833	default n
2834	help
2835	  If enabled this option will include drivers and the core
2836	  infrastructure code to support RapidIO interconnect devices.
2837
2838source "drivers/rapidio/Kconfig"
2839
2840config X86_SYSFB
2841	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2842	help
2843	  Firmwares often provide initial graphics framebuffers so the BIOS,
2844	  bootloader or kernel can show basic video-output during boot for
2845	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2846	  Extensions and EFI-framebuffers for this, which are mostly limited
2847	  to x86.
2848	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2849	  framebuffers so the new generic system-framebuffer drivers can be
2850	  used on x86. If the framebuffer is not compatible with the generic
2851	  modes, it is adverticed as fallback platform framebuffer so legacy
2852	  drivers like efifb, vesafb and uvesafb can pick it up.
2853	  If this option is not selected, all system framebuffers are always
2854	  marked as fallback platform framebuffers as usual.
2855
2856	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2857	  not be able to pick up generic system framebuffers if this option
2858	  is selected. You are highly encouraged to enable simplefb as
2859	  replacement if you select this option. simplefb can correctly deal
2860	  with generic system framebuffers. But you should still keep vesafb
2861	  and others enabled as fallback if a system framebuffer is
2862	  incompatible with simplefb.
2863
2864	  If unsure, say Y.
2865
2866endmenu
2867
2868
2869menu "Executable file formats / Emulations"
2870
2871source "fs/Kconfig.binfmt"
2872
2873config IA32_EMULATION
2874	bool "IA32 Emulation"
2875	depends on X86_64
2876	select ARCH_WANT_OLD_COMPAT_IPC
2877	select BINFMT_ELF
2878	select COMPAT_BINFMT_ELF
2879	select COMPAT_OLD_SIGACTION
2880	---help---
2881	  Include code to run legacy 32-bit programs under a
2882	  64-bit kernel. You should likely turn this on, unless you're
2883	  100% sure that you don't have any 32-bit programs left.
2884
2885config IA32_AOUT
2886	tristate "IA32 a.out support"
2887	depends on IA32_EMULATION
2888	---help---
2889	  Support old a.out binaries in the 32bit emulation.
2890
2891config X86_X32
2892	bool "x32 ABI for 64-bit mode"
2893	depends on X86_64
2894	---help---
2895	  Include code to run binaries for the x32 native 32-bit ABI
2896	  for 64-bit processors.  An x32 process gets access to the
2897	  full 64-bit register file and wide data path while leaving
2898	  pointers at 32 bits for smaller memory footprint.
2899
2900	  You will need a recent binutils (2.22 or later) with
2901	  elf32_x86_64 support enabled to compile a kernel with this
2902	  option set.
2903
2904config COMPAT_32
2905	def_bool y
2906	depends on IA32_EMULATION || X86_32
2907	select HAVE_UID16
2908	select OLD_SIGSUSPEND3
2909
2910config COMPAT
2911	def_bool y
2912	depends on IA32_EMULATION || X86_X32
2913
2914if COMPAT
2915config COMPAT_FOR_U64_ALIGNMENT
2916	def_bool y
2917
2918config SYSVIPC_COMPAT
2919	def_bool y
2920	depends on SYSVIPC
2921endif
2922
2923endmenu
2924
2925
2926config HAVE_ATOMIC_IOMAP
2927	def_bool y
2928	depends on X86_32
2929
2930config X86_DEV_DMA_OPS
2931	bool
2932	depends on X86_64 || STA2X11
2933
2934config X86_DMA_REMAP
2935	bool
2936	depends on STA2X11
2937
2938config HAVE_GENERIC_GUP
2939	def_bool y
2940
2941source "net/Kconfig"
2942
2943source "drivers/Kconfig"
2944
2945source "drivers/firmware/Kconfig"
2946
2947source "fs/Kconfig"
2948
2949source "arch/x86/Kconfig.debug"
2950
2951source "security/Kconfig"
2952
2953source "crypto/Kconfig"
2954
2955source "arch/x86/kvm/Kconfig"
2956
2957source "lib/Kconfig"
2958