xref: /openbmc/linux/arch/x86/Kconfig (revision feac8c8b)
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 X86_DEV_DMA_OPS
32
33#
34# Arch settings
35#
36# ( Note that options that are marked 'if X86_64' could in principle be
37#   ported to 32-bit as well. )
38#
39config X86
40	def_bool y
41	#
42	# Note: keep this list sorted alphabetically
43	#
44	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
45	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
46	select ANON_INODES
47	select ARCH_CLOCKSOURCE_DATA
48	select ARCH_DISCARD_MEMBLOCK
49	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
50	select ARCH_HAS_DEBUG_VIRTUAL
51	select ARCH_HAS_DEVMEM_IS_ALLOWED
52	select ARCH_HAS_ELF_RANDOMIZE
53	select ARCH_HAS_FAST_MULTIPLIER
54	select ARCH_HAS_FORTIFY_SOURCE
55	select ARCH_HAS_GCOV_PROFILE_ALL
56	select ARCH_HAS_KCOV			if X86_64
57	select ARCH_HAS_PHYS_TO_DMA
58	select ARCH_HAS_MEMBARRIER_SYNC_CORE
59	select ARCH_HAS_PMEM_API		if X86_64
60	select ARCH_HAS_REFCOUNT
61	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
62	select ARCH_HAS_SET_MEMORY
63	select ARCH_HAS_SG_CHAIN
64	select ARCH_HAS_STRICT_KERNEL_RWX
65	select ARCH_HAS_STRICT_MODULE_RWX
66	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
67	select ARCH_HAS_UBSAN_SANITIZE_ALL
68	select ARCH_HAS_ZONE_DEVICE		if X86_64
69	select ARCH_HAVE_NMI_SAFE_CMPXCHG
70	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
71	select ARCH_MIGHT_HAVE_PC_PARPORT
72	select ARCH_MIGHT_HAVE_PC_SERIO
73	select ARCH_SUPPORTS_ATOMIC_RMW
74	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
75	select ARCH_USE_BUILTIN_BSWAP
76	select ARCH_USE_QUEUED_RWLOCKS
77	select ARCH_USE_QUEUED_SPINLOCKS
78	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
79	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
80	select ARCH_WANTS_THP_SWAP		if X86_64
81	select BUILDTIME_EXTABLE_SORT
82	select CLKEVT_I8253
83	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
84	select CLOCKSOURCE_WATCHDOG
85	select DCACHE_WORD_ACCESS
86	select EDAC_ATOMIC_SCRUB
87	select EDAC_SUPPORT
88	select GENERIC_CLOCKEVENTS
89	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
90	select GENERIC_CLOCKEVENTS_MIN_ADJUST
91	select GENERIC_CMOS_UPDATE
92	select GENERIC_CPU_AUTOPROBE
93	select GENERIC_CPU_VULNERABILITIES
94	select GENERIC_EARLY_IOREMAP
95	select GENERIC_FIND_FIRST_BIT
96	select GENERIC_IOMAP
97	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
98	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
99	select GENERIC_IRQ_MIGRATION		if SMP
100	select GENERIC_IRQ_PROBE
101	select GENERIC_IRQ_RESERVATION_MODE
102	select GENERIC_IRQ_SHOW
103	select GENERIC_PENDING_IRQ		if SMP
104	select GENERIC_SMP_IDLE_THREAD
105	select GENERIC_STRNCPY_FROM_USER
106	select GENERIC_STRNLEN_USER
107	select GENERIC_TIME_VSYSCALL
108	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
109	select HAVE_ACPI_APEI			if ACPI
110	select HAVE_ACPI_APEI_NMI		if ACPI
111	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
112	select HAVE_ARCH_AUDITSYSCALL
113	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
114	select HAVE_ARCH_JUMP_LABEL
115	select HAVE_ARCH_KASAN			if X86_64
116	select HAVE_ARCH_KGDB
117	select HAVE_ARCH_MMAP_RND_BITS		if MMU
118	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
119	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
120	select HAVE_ARCH_SECCOMP_FILTER
121	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
122	select HAVE_ARCH_TRACEHOOK
123	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
124	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
125	select HAVE_ARCH_VMAP_STACK		if X86_64
126	select HAVE_ARCH_WITHIN_STACK_FRAMES
127	select HAVE_CC_STACKPROTECTOR
128	select HAVE_CMPXCHG_DOUBLE
129	select HAVE_CMPXCHG_LOCAL
130	select HAVE_CONTEXT_TRACKING		if X86_64
131	select HAVE_COPY_THREAD_TLS
132	select HAVE_C_RECORDMCOUNT
133	select HAVE_DEBUG_KMEMLEAK
134	select HAVE_DEBUG_STACKOVERFLOW
135	select HAVE_DMA_API_DEBUG
136	select HAVE_DMA_CONTIGUOUS
137	select HAVE_DYNAMIC_FTRACE
138	select HAVE_DYNAMIC_FTRACE_WITH_REGS
139	select HAVE_EBPF_JIT			if X86_64
140	select HAVE_EFFICIENT_UNALIGNED_ACCESS
141	select HAVE_EXIT_THREAD
142	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
143	select HAVE_FTRACE_MCOUNT_RECORD
144	select HAVE_FUNCTION_GRAPH_TRACER
145	select HAVE_FUNCTION_TRACER
146	select HAVE_GCC_PLUGINS
147	select HAVE_HW_BREAKPOINT
148	select HAVE_IDE
149	select HAVE_IOREMAP_PROT
150	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
151	select HAVE_IRQ_TIME_ACCOUNTING
152	select HAVE_KERNEL_BZIP2
153	select HAVE_KERNEL_GZIP
154	select HAVE_KERNEL_LZ4
155	select HAVE_KERNEL_LZMA
156	select HAVE_KERNEL_LZO
157	select HAVE_KERNEL_XZ
158	select HAVE_KPROBES
159	select HAVE_KPROBES_ON_FTRACE
160	select HAVE_FUNCTION_ERROR_INJECTION
161	select HAVE_KRETPROBES
162	select HAVE_KVM
163	select HAVE_LIVEPATCH			if X86_64
164	select HAVE_MEMBLOCK
165	select HAVE_MEMBLOCK_NODE_MAP
166	select HAVE_MIXED_BREAKPOINTS_REGS
167	select HAVE_MOD_ARCH_SPECIFIC
168	select HAVE_NMI
169	select HAVE_OPROFILE
170	select HAVE_OPTPROBES
171	select HAVE_PCSPKR_PLATFORM
172	select HAVE_PERF_EVENTS
173	select HAVE_PERF_EVENTS_NMI
174	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
175	select HAVE_PERF_REGS
176	select HAVE_PERF_USER_STACK_DUMP
177	select HAVE_RCU_TABLE_FREE
178	select HAVE_REGS_AND_STACK_ACCESS_API
179	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
180	select HAVE_STACK_VALIDATION		if X86_64
181	select HAVE_SYSCALL_TRACEPOINTS
182	select HAVE_UNSTABLE_SCHED_CLOCK
183	select HAVE_USER_RETURN_NOTIFIER
184	select IRQ_FORCED_THREADING
185	select PCI_LOCKLESS_CONFIG
186	select PERF_EVENTS
187	select RTC_LIB
188	select RTC_MC146818_LIB
189	select SPARSE_IRQ
190	select SRCU
191	select SYSCTL_EXCEPTION_TRACE
192	select THREAD_INFO_IN_TASK
193	select USER_STACKTRACE_SUPPORT
194	select VIRT_TO_BUS
195	select X86_FEATURE_NAMES		if PROC_FS
196
197config INSTRUCTION_DECODER
198	def_bool y
199	depends on KPROBES || PERF_EVENTS || UPROBES
200
201config OUTPUT_FORMAT
202	string
203	default "elf32-i386" if X86_32
204	default "elf64-x86-64" if X86_64
205
206config ARCH_DEFCONFIG
207	string
208	default "arch/x86/configs/i386_defconfig" if X86_32
209	default "arch/x86/configs/x86_64_defconfig" if X86_64
210
211config LOCKDEP_SUPPORT
212	def_bool y
213
214config STACKTRACE_SUPPORT
215	def_bool y
216
217config MMU
218	def_bool y
219
220config ARCH_MMAP_RND_BITS_MIN
221	default 28 if 64BIT
222	default 8
223
224config ARCH_MMAP_RND_BITS_MAX
225	default 32 if 64BIT
226	default 16
227
228config ARCH_MMAP_RND_COMPAT_BITS_MIN
229	default 8
230
231config ARCH_MMAP_RND_COMPAT_BITS_MAX
232	default 16
233
234config SBUS
235	bool
236
237config NEED_DMA_MAP_STATE
238	def_bool y
239	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
240
241config NEED_SG_DMA_LENGTH
242	def_bool y
243
244config GENERIC_ISA_DMA
245	def_bool y
246	depends on ISA_DMA_API
247
248config GENERIC_BUG
249	def_bool y
250	depends on BUG
251	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
252
253config GENERIC_BUG_RELATIVE_POINTERS
254	bool
255
256config GENERIC_HWEIGHT
257	def_bool y
258
259config ARCH_MAY_HAVE_PC_FDC
260	def_bool y
261	depends on ISA_DMA_API
262
263config RWSEM_XCHGADD_ALGORITHM
264	def_bool y
265
266config GENERIC_CALIBRATE_DELAY
267	def_bool y
268
269config ARCH_HAS_CPU_RELAX
270	def_bool y
271
272config ARCH_HAS_CACHE_LINE_SIZE
273	def_bool y
274
275config HAVE_SETUP_PER_CPU_AREA
276	def_bool y
277
278config NEED_PER_CPU_EMBED_FIRST_CHUNK
279	def_bool y
280
281config NEED_PER_CPU_PAGE_FIRST_CHUNK
282	def_bool y
283
284config ARCH_HIBERNATION_POSSIBLE
285	def_bool y
286
287config ARCH_SUSPEND_POSSIBLE
288	def_bool y
289
290config ARCH_WANT_HUGE_PMD_SHARE
291	def_bool y
292
293config ARCH_WANT_GENERAL_HUGETLB
294	def_bool y
295
296config ZONE_DMA32
297	def_bool y if X86_64
298
299config AUDIT_ARCH
300	def_bool y if X86_64
301
302config ARCH_SUPPORTS_OPTIMIZED_INLINING
303	def_bool y
304
305config ARCH_SUPPORTS_DEBUG_PAGEALLOC
306	def_bool y
307
308config KASAN_SHADOW_OFFSET
309	hex
310	depends on KASAN
311	default 0xdffffc0000000000
312
313config HAVE_INTEL_TXT
314	def_bool y
315	depends on INTEL_IOMMU && ACPI
316
317config X86_32_SMP
318	def_bool y
319	depends on X86_32 && SMP
320
321config X86_64_SMP
322	def_bool y
323	depends on X86_64 && SMP
324
325config X86_32_LAZY_GS
326	def_bool y
327	depends on X86_32 && CC_STACKPROTECTOR_NONE
328
329config ARCH_SUPPORTS_UPROBES
330	def_bool y
331
332config FIX_EARLYCON_MEM
333	def_bool y
334
335config PGTABLE_LEVELS
336	int
337	default 5 if X86_5LEVEL
338	default 4 if X86_64
339	default 3 if X86_PAE
340	default 2
341
342source "init/Kconfig"
343source "kernel/Kconfig.freezer"
344
345menu "Processor type and features"
346
347config ZONE_DMA
348	bool "DMA memory allocation support" if EXPERT
349	default y
350	help
351	  DMA memory allocation support allows devices with less than 32-bit
352	  addressing to allocate within the first 16MB of address space.
353	  Disable if no such devices will be used.
354
355	  If unsure, say Y.
356
357config SMP
358	bool "Symmetric multi-processing support"
359	---help---
360	  This enables support for systems with more than one CPU. If you have
361	  a system with only one CPU, say N. If you have a system with more
362	  than one CPU, say Y.
363
364	  If you say N here, the kernel will run on uni- and multiprocessor
365	  machines, but will use only one CPU of a multiprocessor machine. If
366	  you say Y here, the kernel will run on many, but not all,
367	  uniprocessor machines. On a uniprocessor machine, the kernel
368	  will run faster if you say N here.
369
370	  Note that if you say Y here and choose architecture "586" or
371	  "Pentium" under "Processor family", the kernel will not work on 486
372	  architectures. Similarly, multiprocessor kernels for the "PPro"
373	  architecture may not work on all Pentium based boards.
374
375	  People using multiprocessor machines who say Y here should also say
376	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
377	  Management" code will be disabled if you say Y here.
378
379	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
380	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
381	  <http://www.tldp.org/docs.html#howto>.
382
383	  If you don't know what to do here, say N.
384
385config X86_FEATURE_NAMES
386	bool "Processor feature human-readable names" if EMBEDDED
387	default y
388	---help---
389	  This option compiles in a table of x86 feature bits and corresponding
390	  names.  This is required to support /proc/cpuinfo and a few kernel
391	  messages.  You can disable this to save space, at the expense of
392	  making those few kernel messages show numeric feature bits instead.
393
394	  If in doubt, say Y.
395
396config X86_FAST_FEATURE_TESTS
397	bool "Fast CPU feature tests" if EMBEDDED
398	default y
399	---help---
400	  Some fast-paths in the kernel depend on the capabilities of the CPU.
401	  Say Y here for the kernel to patch in the appropriate code at runtime
402	  based on the capabilities of the CPU. The infrastructure for patching
403	  code at runtime takes up some additional space; space-constrained
404	  embedded systems may wish to say N here to produce smaller, slightly
405	  slower code.
406
407config X86_X2APIC
408	bool "Support x2apic"
409	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
410	---help---
411	  This enables x2apic support on CPUs that have this feature.
412
413	  This allows 32-bit apic IDs (so it can support very large systems),
414	  and accesses the local apic via MSRs not via mmio.
415
416	  If you don't know what to do here, say N.
417
418config X86_MPPARSE
419	bool "Enable MPS table" if ACPI || SFI
420	default y
421	depends on X86_LOCAL_APIC
422	---help---
423	  For old smp systems that do not have proper acpi support. Newer systems
424	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
425
426config GOLDFISH
427       def_bool y
428       depends on X86_GOLDFISH
429
430config RETPOLINE
431	bool "Avoid speculative indirect branches in kernel"
432	default y
433	select STACK_VALIDATION if HAVE_STACK_VALIDATION
434	help
435	  Compile kernel with the retpoline compiler options to guard against
436	  kernel-to-user data leaks by avoiding speculative indirect
437	  branches. Requires a compiler with -mindirect-branch=thunk-extern
438	  support for full protection. The kernel may run slower.
439
440	  Without compiler support, at least indirect branches in assembler
441	  code are eliminated. Since this includes the syscall entry path,
442	  it is not entirely pointless.
443
444config INTEL_RDT
445	bool "Intel Resource Director Technology support"
446	default n
447	depends on X86 && CPU_SUP_INTEL
448	select KERNFS
449	help
450	  Select to enable resource allocation and monitoring which are
451	  sub-features of Intel Resource Director Technology(RDT). More
452	  information about RDT can be found in the Intel x86
453	  Architecture Software Developer Manual.
454
455	  Say N if unsure.
456
457if X86_32
458config X86_BIGSMP
459	bool "Support for big SMP systems with more than 8 CPUs"
460	depends on SMP
461	---help---
462	  This option is needed for the systems that have more than 8 CPUs
463
464config X86_EXTENDED_PLATFORM
465	bool "Support for extended (non-PC) x86 platforms"
466	default y
467	---help---
468	  If you disable this option then the kernel will only support
469	  standard PC platforms. (which covers the vast majority of
470	  systems out there.)
471
472	  If you enable this option then you'll be able to select support
473	  for the following (non-PC) 32 bit x86 platforms:
474		Goldfish (Android emulator)
475		AMD Elan
476		RDC R-321x SoC
477		SGI 320/540 (Visual Workstation)
478		STA2X11-based (e.g. Northville)
479		Moorestown MID devices
480
481	  If you have one of these systems, or if you want to build a
482	  generic distribution kernel, say Y here - otherwise say N.
483endif
484
485if X86_64
486config X86_EXTENDED_PLATFORM
487	bool "Support for extended (non-PC) x86 platforms"
488	default y
489	---help---
490	  If you disable this option then the kernel will only support
491	  standard PC platforms. (which covers the vast majority of
492	  systems out there.)
493
494	  If you enable this option then you'll be able to select support
495	  for the following (non-PC) 64 bit x86 platforms:
496		Numascale NumaChip
497		ScaleMP vSMP
498		SGI Ultraviolet
499
500	  If you have one of these systems, or if you want to build a
501	  generic distribution kernel, say Y here - otherwise say N.
502endif
503# This is an alphabetically sorted list of 64 bit extended platforms
504# Please maintain the alphabetic order if and when there are additions
505config X86_NUMACHIP
506	bool "Numascale NumaChip"
507	depends on X86_64
508	depends on X86_EXTENDED_PLATFORM
509	depends on NUMA
510	depends on SMP
511	depends on X86_X2APIC
512	depends on PCI_MMCONFIG
513	---help---
514	  Adds support for Numascale NumaChip large-SMP systems. Needed to
515	  enable more than ~168 cores.
516	  If you don't have one of these, you should say N here.
517
518config X86_VSMP
519	bool "ScaleMP vSMP"
520	select HYPERVISOR_GUEST
521	select PARAVIRT
522	depends on X86_64 && PCI
523	depends on X86_EXTENDED_PLATFORM
524	depends on SMP
525	---help---
526	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
527	  supposed to run on these EM64T-based machines.  Only choose this option
528	  if you have one of these machines.
529
530config X86_UV
531	bool "SGI Ultraviolet"
532	depends on X86_64
533	depends on X86_EXTENDED_PLATFORM
534	depends on NUMA
535	depends on EFI
536	depends on X86_X2APIC
537	depends on PCI
538	---help---
539	  This option is needed in order to support SGI Ultraviolet systems.
540	  If you don't have one of these, you should say N here.
541
542# Following is an alphabetically sorted list of 32 bit extended platforms
543# Please maintain the alphabetic order if and when there are additions
544
545config X86_GOLDFISH
546       bool "Goldfish (Virtual Platform)"
547       depends on X86_EXTENDED_PLATFORM
548       ---help---
549	 Enable support for the Goldfish virtual platform used primarily
550	 for Android development. Unless you are building for the Android
551	 Goldfish emulator say N here.
552
553config X86_INTEL_CE
554	bool "CE4100 TV platform"
555	depends on PCI
556	depends on PCI_GODIRECT
557	depends on X86_IO_APIC
558	depends on X86_32
559	depends on X86_EXTENDED_PLATFORM
560	select X86_REBOOTFIXUPS
561	select OF
562	select OF_EARLY_FLATTREE
563	---help---
564	  Select for the Intel CE media processor (CE4100) SOC.
565	  This option compiles in support for the CE4100 SOC for settop
566	  boxes and media devices.
567
568config X86_INTEL_MID
569	bool "Intel MID platform support"
570	depends on X86_EXTENDED_PLATFORM
571	depends on X86_PLATFORM_DEVICES
572	depends on PCI
573	depends on X86_64 || (PCI_GOANY && X86_32)
574	depends on X86_IO_APIC
575	select SFI
576	select I2C
577	select DW_APB_TIMER
578	select APB_TIMER
579	select INTEL_SCU_IPC
580	select MFD_INTEL_MSIC
581	---help---
582	  Select to build a kernel capable of supporting Intel MID (Mobile
583	  Internet Device) platform systems which do not have the PCI legacy
584	  interfaces. If you are building for a PC class system say N here.
585
586	  Intel MID platforms are based on an Intel processor and chipset which
587	  consume less power than most of the x86 derivatives.
588
589config X86_INTEL_QUARK
590	bool "Intel Quark platform support"
591	depends on X86_32
592	depends on X86_EXTENDED_PLATFORM
593	depends on X86_PLATFORM_DEVICES
594	depends on X86_TSC
595	depends on PCI
596	depends on PCI_GOANY
597	depends on X86_IO_APIC
598	select IOSF_MBI
599	select INTEL_IMR
600	select COMMON_CLK
601	---help---
602	  Select to include support for Quark X1000 SoC.
603	  Say Y here if you have a Quark based system such as the Arduino
604	  compatible Intel Galileo.
605
606config X86_INTEL_LPSS
607	bool "Intel Low Power Subsystem Support"
608	depends on X86 && ACPI
609	select COMMON_CLK
610	select PINCTRL
611	select IOSF_MBI
612	---help---
613	  Select to build support for Intel Low Power Subsystem such as
614	  found on Intel Lynxpoint PCH. Selecting this option enables
615	  things like clock tree (common clock framework) and pincontrol
616	  which are needed by the LPSS peripheral drivers.
617
618config X86_AMD_PLATFORM_DEVICE
619	bool "AMD ACPI2Platform devices support"
620	depends on ACPI
621	select COMMON_CLK
622	select PINCTRL
623	---help---
624	  Select to interpret AMD specific ACPI device to platform device
625	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
626	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
627	  implemented under PINCTRL subsystem.
628
629config IOSF_MBI
630	tristate "Intel SoC IOSF Sideband support for SoC platforms"
631	depends on PCI
632	---help---
633	  This option enables sideband register access support for Intel SoC
634	  platforms. On these platforms the IOSF sideband is used in lieu of
635	  MSR's for some register accesses, mostly but not limited to thermal
636	  and power. Drivers may query the availability of this device to
637	  determine if they need the sideband in order to work on these
638	  platforms. The sideband is available on the following SoC products.
639	  This list is not meant to be exclusive.
640	   - BayTrail
641	   - Braswell
642	   - Quark
643
644	  You should say Y if you are running a kernel on one of these SoC's.
645
646config IOSF_MBI_DEBUG
647	bool "Enable IOSF sideband access through debugfs"
648	depends on IOSF_MBI && DEBUG_FS
649	---help---
650	  Select this option to expose the IOSF sideband access registers (MCR,
651	  MDR, MCRX) through debugfs to write and read register information from
652	  different units on the SoC. This is most useful for obtaining device
653	  state information for debug and analysis. As this is a general access
654	  mechanism, users of this option would have specific knowledge of the
655	  device they want to access.
656
657	  If you don't require the option or are in doubt, say N.
658
659config X86_RDC321X
660	bool "RDC R-321x SoC"
661	depends on X86_32
662	depends on X86_EXTENDED_PLATFORM
663	select M486
664	select X86_REBOOTFIXUPS
665	---help---
666	  This option is needed for RDC R-321x system-on-chip, also known
667	  as R-8610-(G).
668	  If you don't have one of these chips, you should say N here.
669
670config X86_32_NON_STANDARD
671	bool "Support non-standard 32-bit SMP architectures"
672	depends on X86_32 && SMP
673	depends on X86_EXTENDED_PLATFORM
674	---help---
675	  This option compiles in the bigsmp and STA2X11 default
676	  subarchitectures.  It is intended for a generic binary
677	  kernel. If you select them all, kernel will probe it one by
678	  one and will fallback to default.
679
680# Alphabetically sorted list of Non standard 32 bit platforms
681
682config X86_SUPPORTS_MEMORY_FAILURE
683	def_bool y
684	# MCE code calls memory_failure():
685	depends on X86_MCE
686	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
687	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
688	depends on X86_64 || !SPARSEMEM
689	select ARCH_SUPPORTS_MEMORY_FAILURE
690
691config STA2X11
692	bool "STA2X11 Companion Chip Support"
693	depends on X86_32_NON_STANDARD && PCI
694	select X86_DEV_DMA_OPS
695	select X86_DMA_REMAP
696	select SWIOTLB
697	select MFD_STA2X11
698	select GPIOLIB
699	default n
700	---help---
701	  This adds support for boards based on the STA2X11 IO-Hub,
702	  a.k.a. "ConneXt". The chip is used in place of the standard
703	  PC chipset, so all "standard" peripherals are missing. If this
704	  option is selected the kernel will still be able to boot on
705	  standard PC machines.
706
707config X86_32_IRIS
708	tristate "Eurobraille/Iris poweroff module"
709	depends on X86_32
710	---help---
711	  The Iris machines from EuroBraille do not have APM or ACPI support
712	  to shut themselves down properly.  A special I/O sequence is
713	  needed to do so, which is what this module does at
714	  kernel shutdown.
715
716	  This is only for Iris machines from EuroBraille.
717
718	  If unused, say N.
719
720config SCHED_OMIT_FRAME_POINTER
721	def_bool y
722	prompt "Single-depth WCHAN output"
723	depends on X86
724	---help---
725	  Calculate simpler /proc/<PID>/wchan values. If this option
726	  is disabled then wchan values will recurse back to the
727	  caller function. This provides more accurate wchan values,
728	  at the expense of slightly more scheduling overhead.
729
730	  If in doubt, say "Y".
731
732menuconfig HYPERVISOR_GUEST
733	bool "Linux guest support"
734	---help---
735	  Say Y here to enable options for running Linux under various hyper-
736	  visors. This option enables basic hypervisor detection and platform
737	  setup.
738
739	  If you say N, all options in this submenu will be skipped and
740	  disabled, and Linux guest support won't be built in.
741
742if HYPERVISOR_GUEST
743
744config PARAVIRT
745	bool "Enable paravirtualization code"
746	---help---
747	  This changes the kernel so it can modify itself when it is run
748	  under a hypervisor, potentially improving performance significantly
749	  over full virtualization.  However, when run without a hypervisor
750	  the kernel is theoretically slower and slightly larger.
751
752config PARAVIRT_DEBUG
753	bool "paravirt-ops debugging"
754	depends on PARAVIRT && DEBUG_KERNEL
755	---help---
756	  Enable to debug paravirt_ops internals.  Specifically, BUG if
757	  a paravirt_op is missing when it is called.
758
759config PARAVIRT_SPINLOCKS
760	bool "Paravirtualization layer for spinlocks"
761	depends on PARAVIRT && SMP
762	---help---
763	  Paravirtualized spinlocks allow a pvops backend to replace the
764	  spinlock implementation with something virtualization-friendly
765	  (for example, block the virtual CPU rather than spinning).
766
767	  It has a minimal impact on native kernels and gives a nice performance
768	  benefit on paravirtualized KVM / Xen kernels.
769
770	  If you are unsure how to answer this question, answer Y.
771
772config QUEUED_LOCK_STAT
773	bool "Paravirt queued spinlock statistics"
774	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
775	---help---
776	  Enable the collection of statistical data on the slowpath
777	  behavior of paravirtualized queued spinlocks and report
778	  them on debugfs.
779
780source "arch/x86/xen/Kconfig"
781
782config KVM_GUEST
783	bool "KVM Guest support (including kvmclock)"
784	depends on PARAVIRT
785	select PARAVIRT_CLOCK
786	default y
787	---help---
788	  This option enables various optimizations for running under the KVM
789	  hypervisor. It includes a paravirtualized clock, so that instead
790	  of relying on a PIT (or probably other) emulation by the
791	  underlying device model, the host provides the guest with
792	  timing infrastructure such as time of day, and system time
793
794config KVM_DEBUG_FS
795	bool "Enable debug information for KVM Guests in debugfs"
796	depends on KVM_GUEST && DEBUG_FS
797	default n
798	---help---
799	  This option enables collection of various statistics for KVM guest.
800	  Statistics are displayed in debugfs filesystem. Enabling this option
801	  may incur significant overhead.
802
803config PARAVIRT_TIME_ACCOUNTING
804	bool "Paravirtual steal time accounting"
805	depends on PARAVIRT
806	default n
807	---help---
808	  Select this option to enable fine granularity task steal time
809	  accounting. Time spent executing other tasks in parallel with
810	  the current vCPU is discounted from the vCPU power. To account for
811	  that, there can be a small performance impact.
812
813	  If in doubt, say N here.
814
815config PARAVIRT_CLOCK
816	bool
817
818config JAILHOUSE_GUEST
819	bool "Jailhouse non-root cell support"
820	depends on X86_64 && PCI
821	select X86_PM_TIMER
822	---help---
823	  This option allows to run Linux as guest in a Jailhouse non-root
824	  cell. You can leave this option disabled if you only want to start
825	  Jailhouse and run Linux afterwards in the root cell.
826
827endif #HYPERVISOR_GUEST
828
829config NO_BOOTMEM
830	def_bool y
831
832source "arch/x86/Kconfig.cpu"
833
834config HPET_TIMER
835	def_bool X86_64
836	prompt "HPET Timer Support" if X86_32
837	---help---
838	  Use the IA-PC HPET (High Precision Event Timer) to manage
839	  time in preference to the PIT and RTC, if a HPET is
840	  present.
841	  HPET is the next generation timer replacing legacy 8254s.
842	  The HPET provides a stable time base on SMP
843	  systems, unlike the TSC, but it is more expensive to access,
844	  as it is off-chip.  The interface used is documented
845	  in the HPET spec, revision 1.
846
847	  You can safely choose Y here.  However, HPET will only be
848	  activated if the platform and the BIOS support this feature.
849	  Otherwise the 8254 will be used for timing services.
850
851	  Choose N to continue using the legacy 8254 timer.
852
853config HPET_EMULATE_RTC
854	def_bool y
855	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
856
857config APB_TIMER
858       def_bool y if X86_INTEL_MID
859       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
860       select DW_APB_TIMER
861       depends on X86_INTEL_MID && SFI
862       help
863         APB timer is the replacement for 8254, HPET on X86 MID platforms.
864         The APBT provides a stable time base on SMP
865         systems, unlike the TSC, but it is more expensive to access,
866         as it is off-chip. APB timers are always running regardless of CPU
867         C states, they are used as per CPU clockevent device when possible.
868
869# Mark as expert because too many people got it wrong.
870# The code disables itself when not needed.
871config DMI
872	default y
873	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
874	bool "Enable DMI scanning" if EXPERT
875	---help---
876	  Enabled scanning of DMI to identify machine quirks. Say Y
877	  here unless you have verified that your setup is not
878	  affected by entries in the DMI blacklist. Required by PNP
879	  BIOS code.
880
881config GART_IOMMU
882	bool "Old AMD GART IOMMU support"
883	select SWIOTLB
884	depends on X86_64 && PCI && AMD_NB
885	---help---
886	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
887	  GART based hardware IOMMUs.
888
889	  The GART supports full DMA access for devices with 32-bit access
890	  limitations, on systems with more than 3 GB. This is usually needed
891	  for USB, sound, many IDE/SATA chipsets and some other devices.
892
893	  Newer systems typically have a modern AMD IOMMU, supported via
894	  the CONFIG_AMD_IOMMU=y config option.
895
896	  In normal configurations this driver is only active when needed:
897	  there's more than 3 GB of memory and the system contains a
898	  32-bit limited device.
899
900	  If unsure, say Y.
901
902config CALGARY_IOMMU
903	bool "IBM Calgary IOMMU support"
904	select SWIOTLB
905	depends on X86_64 && PCI
906	---help---
907	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
908	  systems. Needed to run systems with more than 3GB of memory
909	  properly with 32-bit PCI devices that do not support DAC
910	  (Double Address Cycle). Calgary also supports bus level
911	  isolation, where all DMAs pass through the IOMMU.  This
912	  prevents them from going anywhere except their intended
913	  destination. This catches hard-to-find kernel bugs and
914	  mis-behaving drivers and devices that do not use the DMA-API
915	  properly to set up their DMA buffers.  The IOMMU can be
916	  turned off at boot time with the iommu=off parameter.
917	  Normally the kernel will make the right choice by itself.
918	  If unsure, say Y.
919
920config CALGARY_IOMMU_ENABLED_BY_DEFAULT
921	def_bool y
922	prompt "Should Calgary be enabled by default?"
923	depends on CALGARY_IOMMU
924	---help---
925	  Should Calgary be enabled by default? if you choose 'y', Calgary
926	  will be used (if it exists). If you choose 'n', Calgary will not be
927	  used even if it exists. If you choose 'n' and would like to use
928	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
929	  If unsure, say Y.
930
931# need this always selected by IOMMU for the VIA workaround
932config SWIOTLB
933	def_bool y if X86_64
934	---help---
935	  Support for software bounce buffers used on x86-64 systems
936	  which don't have a hardware IOMMU. Using this PCI devices
937	  which can only access 32-bits of memory can be used on systems
938	  with more than 3 GB of memory.
939	  If unsure, say Y.
940
941config IOMMU_HELPER
942	def_bool y
943	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
944
945config MAXSMP
946	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
947	depends on X86_64 && SMP && DEBUG_KERNEL
948	select CPUMASK_OFFSTACK
949	---help---
950	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
951	  If unsure, say N.
952
953#
954# The maximum number of CPUs supported:
955#
956# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
957# and which can be configured interactively in the
958# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
959#
960# The ranges are different on 32-bit and 64-bit kernels, depending on
961# hardware capabilities and scalability features of the kernel.
962#
963# ( If MAXSMP is enabled we just use the highest possible value and disable
964#   interactive configuration. )
965#
966
967config NR_CPUS_RANGE_BEGIN
968	int
969	default NR_CPUS_RANGE_END if MAXSMP
970	default    1 if !SMP
971	default    2
972
973config NR_CPUS_RANGE_END
974	int
975	depends on X86_32
976	default   64 if  SMP &&  X86_BIGSMP
977	default    8 if  SMP && !X86_BIGSMP
978	default    1 if !SMP
979
980config NR_CPUS_RANGE_END
981	int
982	depends on X86_64
983	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
984	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
985	default    1 if !SMP
986
987config NR_CPUS_DEFAULT
988	int
989	depends on X86_32
990	default   32 if  X86_BIGSMP
991	default    8 if  SMP
992	default    1 if !SMP
993
994config NR_CPUS_DEFAULT
995	int
996	depends on X86_64
997	default 8192 if  MAXSMP
998	default   64 if  SMP
999	default    1 if !SMP
1000
1001config NR_CPUS
1002	int "Maximum number of CPUs" if SMP && !MAXSMP
1003	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1004	default NR_CPUS_DEFAULT
1005	---help---
1006	  This allows you to specify the maximum number of CPUs which this
1007	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1008	  supported value is 8192, otherwise the maximum value is 512.  The
1009	  minimum value which makes sense is 2.
1010
1011	  This is purely to save memory: each supported CPU adds about 8KB
1012	  to the kernel image.
1013
1014config SCHED_SMT
1015	bool "SMT (Hyperthreading) scheduler support"
1016	depends on SMP
1017	---help---
1018	  SMT scheduler support improves the CPU scheduler's decision making
1019	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1020	  cost of slightly increased overhead in some places. If unsure say
1021	  N here.
1022
1023config SCHED_MC
1024	def_bool y
1025	prompt "Multi-core scheduler support"
1026	depends on SMP
1027	---help---
1028	  Multi-core scheduler support improves the CPU scheduler's decision
1029	  making when dealing with multi-core CPU chips at a cost of slightly
1030	  increased overhead in some places. If unsure say N here.
1031
1032config SCHED_MC_PRIO
1033	bool "CPU core priorities scheduler support"
1034	depends on SCHED_MC && CPU_SUP_INTEL
1035	select X86_INTEL_PSTATE
1036	select CPU_FREQ
1037	default y
1038	---help---
1039	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1040	  core ordering determined at manufacturing time, which allows
1041	  certain cores to reach higher turbo frequencies (when running
1042	  single threaded workloads) than others.
1043
1044	  Enabling this kernel feature teaches the scheduler about
1045	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1046	  scheduler's CPU selection logic accordingly, so that higher
1047	  overall system performance can be achieved.
1048
1049	  This feature will have no effect on CPUs without this feature.
1050
1051	  If unsure say Y here.
1052
1053source "kernel/Kconfig.preempt"
1054
1055config UP_LATE_INIT
1056       def_bool y
1057       depends on !SMP && X86_LOCAL_APIC
1058
1059config X86_UP_APIC
1060	bool "Local APIC support on uniprocessors" if !PCI_MSI
1061	default PCI_MSI
1062	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1063	---help---
1064	  A local APIC (Advanced Programmable Interrupt Controller) is an
1065	  integrated interrupt controller in the CPU. If you have a single-CPU
1066	  system which has a processor with a local APIC, you can say Y here to
1067	  enable and use it. If you say Y here even though your machine doesn't
1068	  have a local APIC, then the kernel will still run with no slowdown at
1069	  all. The local APIC supports CPU-generated self-interrupts (timer,
1070	  performance counters), and the NMI watchdog which detects hard
1071	  lockups.
1072
1073config X86_UP_IOAPIC
1074	bool "IO-APIC support on uniprocessors"
1075	depends on X86_UP_APIC
1076	---help---
1077	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1078	  SMP-capable replacement for PC-style interrupt controllers. Most
1079	  SMP systems and many recent uniprocessor systems have one.
1080
1081	  If you have a single-CPU system with an IO-APIC, you can say Y here
1082	  to use it. If you say Y here even though your machine doesn't have
1083	  an IO-APIC, then the kernel will still run with no slowdown at all.
1084
1085config X86_LOCAL_APIC
1086	def_bool y
1087	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1088	select IRQ_DOMAIN_HIERARCHY
1089	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1090
1091config X86_IO_APIC
1092	def_bool y
1093	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1094
1095config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1096	bool "Reroute for broken boot IRQs"
1097	depends on X86_IO_APIC
1098	---help---
1099	  This option enables a workaround that fixes a source of
1100	  spurious interrupts. This is recommended when threaded
1101	  interrupt handling is used on systems where the generation of
1102	  superfluous "boot interrupts" cannot be disabled.
1103
1104	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1105	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1106	  kernel does during interrupt handling). On chipsets where this
1107	  boot IRQ generation cannot be disabled, this workaround keeps
1108	  the original IRQ line masked so that only the equivalent "boot
1109	  IRQ" is delivered to the CPUs. The workaround also tells the
1110	  kernel to set up the IRQ handler on the boot IRQ line. In this
1111	  way only one interrupt is delivered to the kernel. Otherwise
1112	  the spurious second interrupt may cause the kernel to bring
1113	  down (vital) interrupt lines.
1114
1115	  Only affects "broken" chipsets. Interrupt sharing may be
1116	  increased on these systems.
1117
1118config X86_MCE
1119	bool "Machine Check / overheating reporting"
1120	select GENERIC_ALLOCATOR
1121	default y
1122	---help---
1123	  Machine Check support allows the processor to notify the
1124	  kernel if it detects a problem (e.g. overheating, data corruption).
1125	  The action the kernel takes depends on the severity of the problem,
1126	  ranging from warning messages to halting the machine.
1127
1128config X86_MCELOG_LEGACY
1129	bool "Support for deprecated /dev/mcelog character device"
1130	depends on X86_MCE
1131	---help---
1132	  Enable support for /dev/mcelog which is needed by the old mcelog
1133	  userspace logging daemon. Consider switching to the new generation
1134	  rasdaemon solution.
1135
1136config X86_MCE_INTEL
1137	def_bool y
1138	prompt "Intel MCE features"
1139	depends on X86_MCE && X86_LOCAL_APIC
1140	---help---
1141	   Additional support for intel specific MCE features such as
1142	   the thermal monitor.
1143
1144config X86_MCE_AMD
1145	def_bool y
1146	prompt "AMD MCE features"
1147	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1148	---help---
1149	   Additional support for AMD specific MCE features such as
1150	   the DRAM Error Threshold.
1151
1152config X86_ANCIENT_MCE
1153	bool "Support for old Pentium 5 / WinChip machine checks"
1154	depends on X86_32 && X86_MCE
1155	---help---
1156	  Include support for machine check handling on old Pentium 5 or WinChip
1157	  systems. These typically need to be enabled explicitly on the command
1158	  line.
1159
1160config X86_MCE_THRESHOLD
1161	depends on X86_MCE_AMD || X86_MCE_INTEL
1162	def_bool y
1163
1164config X86_MCE_INJECT
1165	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1166	tristate "Machine check injector support"
1167	---help---
1168	  Provide support for injecting machine checks for testing purposes.
1169	  If you don't know what a machine check is and you don't do kernel
1170	  QA it is safe to say n.
1171
1172config X86_THERMAL_VECTOR
1173	def_bool y
1174	depends on X86_MCE_INTEL
1175
1176source "arch/x86/events/Kconfig"
1177
1178config X86_LEGACY_VM86
1179	bool "Legacy VM86 support"
1180	default n
1181	depends on X86_32
1182	---help---
1183	  This option allows user programs to put the CPU into V8086
1184	  mode, which is an 80286-era approximation of 16-bit real mode.
1185
1186	  Some very old versions of X and/or vbetool require this option
1187	  for user mode setting.  Similarly, DOSEMU will use it if
1188	  available to accelerate real mode DOS programs.  However, any
1189	  recent version of DOSEMU, X, or vbetool should be fully
1190	  functional even without kernel VM86 support, as they will all
1191	  fall back to software emulation. Nevertheless, if you are using
1192	  a 16-bit DOS program where 16-bit performance matters, vm86
1193	  mode might be faster than emulation and you might want to
1194	  enable this option.
1195
1196	  Note that any app that works on a 64-bit kernel is unlikely to
1197	  need this option, as 64-bit kernels don't, and can't, support
1198	  V8086 mode. This option is also unrelated to 16-bit protected
1199	  mode and is not needed to run most 16-bit programs under Wine.
1200
1201	  Enabling this option increases the complexity of the kernel
1202	  and slows down exception handling a tiny bit.
1203
1204	  If unsure, say N here.
1205
1206config VM86
1207       bool
1208       default X86_LEGACY_VM86
1209
1210config X86_16BIT
1211	bool "Enable support for 16-bit segments" if EXPERT
1212	default y
1213	depends on MODIFY_LDT_SYSCALL
1214	---help---
1215	  This option is required by programs like Wine to run 16-bit
1216	  protected mode legacy code on x86 processors.  Disabling
1217	  this option saves about 300 bytes on i386, or around 6K text
1218	  plus 16K runtime memory on x86-64,
1219
1220config X86_ESPFIX32
1221	def_bool y
1222	depends on X86_16BIT && X86_32
1223
1224config X86_ESPFIX64
1225	def_bool y
1226	depends on X86_16BIT && X86_64
1227
1228config X86_VSYSCALL_EMULATION
1229       bool "Enable vsyscall emulation" if EXPERT
1230       default y
1231       depends on X86_64
1232       ---help---
1233	 This enables emulation of the legacy vsyscall page.  Disabling
1234	 it is roughly equivalent to booting with vsyscall=none, except
1235	 that it will also disable the helpful warning if a program
1236	 tries to use a vsyscall.  With this option set to N, offending
1237	 programs will just segfault, citing addresses of the form
1238	 0xffffffffff600?00.
1239
1240	 This option is required by many programs built before 2013, and
1241	 care should be used even with newer programs if set to N.
1242
1243	 Disabling this option saves about 7K of kernel size and
1244	 possibly 4K of additional runtime pagetable memory.
1245
1246config TOSHIBA
1247	tristate "Toshiba Laptop support"
1248	depends on X86_32
1249	---help---
1250	  This adds a driver to safely access the System Management Mode of
1251	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252	  not work on models with a Phoenix BIOS. The System Management Mode
1253	  is used to set the BIOS and power saving options on Toshiba portables.
1254
1255	  For information on utilities to make use of this driver see the
1256	  Toshiba Linux utilities web site at:
1257	  <http://www.buzzard.org.uk/toshiba/>.
1258
1259	  Say Y if you intend to run this kernel on a Toshiba portable.
1260	  Say N otherwise.
1261
1262config I8K
1263	tristate "Dell i8k legacy laptop support"
1264	select HWMON
1265	select SENSORS_DELL_SMM
1266	---help---
1267	  This option enables legacy /proc/i8k userspace interface in hwmon
1268	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269	  temperature and allows controlling fan speeds of Dell laptops via
1270	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271	  it reports also power and hotkey status. For fan speed control is
1272	  needed userspace package i8kutils.
1273
1274	  Say Y if you intend to run this kernel on old Dell laptops or want to
1275	  use userspace package i8kutils.
1276	  Say N otherwise.
1277
1278config X86_REBOOTFIXUPS
1279	bool "Enable X86 board specific fixups for reboot"
1280	depends on X86_32
1281	---help---
1282	  This enables chipset and/or board specific fixups to be done
1283	  in order to get reboot to work correctly. This is only needed on
1284	  some combinations of hardware and BIOS. The symptom, for which
1285	  this config is intended, is when reboot ends with a stalled/hung
1286	  system.
1287
1288	  Currently, the only fixup is for the Geode machines using
1289	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1290
1291	  Say Y if you want to enable the fixup. Currently, it's safe to
1292	  enable this option even if you don't need it.
1293	  Say N otherwise.
1294
1295config MICROCODE
1296	bool "CPU microcode loading support"
1297	default y
1298	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1299	select FW_LOADER
1300	---help---
1301	  If you say Y here, you will be able to update the microcode on
1302	  Intel and AMD processors. The Intel support is for the IA32 family,
1303	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1304	  AMD support is for families 0x10 and later. You will obviously need
1305	  the actual microcode binary data itself which is not shipped with
1306	  the Linux kernel.
1307
1308	  The preferred method to load microcode from a detached initrd is described
1309	  in Documentation/x86/early-microcode.txt. For that you need to enable
1310	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1311	  initrd for microcode blobs.
1312
1313	  In addition, you can build the microcode into the kernel. For that you
1314	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1315	  config option.
1316
1317config MICROCODE_INTEL
1318	bool "Intel microcode loading support"
1319	depends on MICROCODE
1320	default MICROCODE
1321	select FW_LOADER
1322	---help---
1323	  This options enables microcode patch loading support for Intel
1324	  processors.
1325
1326	  For the current Intel microcode data package go to
1327	  <https://downloadcenter.intel.com> and search for
1328	  'Linux Processor Microcode Data File'.
1329
1330config MICROCODE_AMD
1331	bool "AMD microcode loading support"
1332	depends on MICROCODE
1333	select FW_LOADER
1334	---help---
1335	  If you select this option, microcode patch loading support for AMD
1336	  processors will be enabled.
1337
1338config MICROCODE_OLD_INTERFACE
1339	def_bool y
1340	depends on MICROCODE
1341
1342config X86_MSR
1343	tristate "/dev/cpu/*/msr - Model-specific register support"
1344	---help---
1345	  This device gives privileged processes access to the x86
1346	  Model-Specific Registers (MSRs).  It is a character device with
1347	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1348	  MSR accesses are directed to a specific CPU on multi-processor
1349	  systems.
1350
1351config X86_CPUID
1352	tristate "/dev/cpu/*/cpuid - CPU information support"
1353	---help---
1354	  This device gives processes access to the x86 CPUID instruction to
1355	  be executed on a specific processor.  It is a character device
1356	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1357	  /dev/cpu/31/cpuid.
1358
1359choice
1360	prompt "High Memory Support"
1361	default HIGHMEM4G
1362	depends on X86_32
1363
1364config NOHIGHMEM
1365	bool "off"
1366	---help---
1367	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1368	  However, the address space of 32-bit x86 processors is only 4
1369	  Gigabytes large. That means that, if you have a large amount of
1370	  physical memory, not all of it can be "permanently mapped" by the
1371	  kernel. The physical memory that's not permanently mapped is called
1372	  "high memory".
1373
1374	  If you are compiling a kernel which will never run on a machine with
1375	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1376	  choice and suitable for most users). This will result in a "3GB/1GB"
1377	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1378	  space and the remaining part of the 4GB virtual memory space is used
1379	  by the kernel to permanently map as much physical memory as
1380	  possible.
1381
1382	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1383	  answer "4GB" here.
1384
1385	  If more than 4 Gigabytes is used then answer "64GB" here. This
1386	  selection turns Intel PAE (Physical Address Extension) mode on.
1387	  PAE implements 3-level paging on IA32 processors. PAE is fully
1388	  supported by Linux, PAE mode is implemented on all recent Intel
1389	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1390	  then the kernel will not boot on CPUs that don't support PAE!
1391
1392	  The actual amount of total physical memory will either be
1393	  auto detected or can be forced by using a kernel command line option
1394	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1395	  your boot loader (lilo or loadlin) about how to pass options to the
1396	  kernel at boot time.)
1397
1398	  If unsure, say "off".
1399
1400config HIGHMEM4G
1401	bool "4GB"
1402	---help---
1403	  Select this if you have a 32-bit processor and between 1 and 4
1404	  gigabytes of physical RAM.
1405
1406config HIGHMEM64G
1407	bool "64GB"
1408	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1409	select X86_PAE
1410	---help---
1411	  Select this if you have a 32-bit processor and more than 4
1412	  gigabytes of physical RAM.
1413
1414endchoice
1415
1416choice
1417	prompt "Memory split" if EXPERT
1418	default VMSPLIT_3G
1419	depends on X86_32
1420	---help---
1421	  Select the desired split between kernel and user memory.
1422
1423	  If the address range available to the kernel is less than the
1424	  physical memory installed, the remaining memory will be available
1425	  as "high memory". Accessing high memory is a little more costly
1426	  than low memory, as it needs to be mapped into the kernel first.
1427	  Note that increasing the kernel address space limits the range
1428	  available to user programs, making the address space there
1429	  tighter.  Selecting anything other than the default 3G/1G split
1430	  will also likely make your kernel incompatible with binary-only
1431	  kernel modules.
1432
1433	  If you are not absolutely sure what you are doing, leave this
1434	  option alone!
1435
1436	config VMSPLIT_3G
1437		bool "3G/1G user/kernel split"
1438	config VMSPLIT_3G_OPT
1439		depends on !X86_PAE
1440		bool "3G/1G user/kernel split (for full 1G low memory)"
1441	config VMSPLIT_2G
1442		bool "2G/2G user/kernel split"
1443	config VMSPLIT_2G_OPT
1444		depends on !X86_PAE
1445		bool "2G/2G user/kernel split (for full 2G low memory)"
1446	config VMSPLIT_1G
1447		bool "1G/3G user/kernel split"
1448endchoice
1449
1450config PAGE_OFFSET
1451	hex
1452	default 0xB0000000 if VMSPLIT_3G_OPT
1453	default 0x80000000 if VMSPLIT_2G
1454	default 0x78000000 if VMSPLIT_2G_OPT
1455	default 0x40000000 if VMSPLIT_1G
1456	default 0xC0000000
1457	depends on X86_32
1458
1459config HIGHMEM
1460	def_bool y
1461	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1462
1463config X86_PAE
1464	bool "PAE (Physical Address Extension) Support"
1465	depends on X86_32 && !HIGHMEM4G
1466	select SWIOTLB
1467	---help---
1468	  PAE is required for NX support, and furthermore enables
1469	  larger swapspace support for non-overcommit purposes. It
1470	  has the cost of more pagetable lookup overhead, and also
1471	  consumes more pagetable space per process.
1472
1473config X86_5LEVEL
1474	bool "Enable 5-level page tables support"
1475	depends on X86_64
1476	---help---
1477	  5-level paging enables access to larger address space:
1478	  upto 128 PiB of virtual address space and 4 PiB of
1479	  physical address space.
1480
1481	  It will be supported by future Intel CPUs.
1482
1483	  Note: a kernel with this option enabled can only be booted
1484	  on machines that support the feature.
1485
1486	  See Documentation/x86/x86_64/5level-paging.txt for more
1487	  information.
1488
1489	  Say N if unsure.
1490
1491config ARCH_PHYS_ADDR_T_64BIT
1492	def_bool y
1493	depends on X86_64 || X86_PAE
1494
1495config ARCH_DMA_ADDR_T_64BIT
1496	def_bool y
1497	depends on X86_64 || HIGHMEM64G
1498
1499config X86_DIRECT_GBPAGES
1500	def_bool y
1501	depends on X86_64 && !DEBUG_PAGEALLOC
1502	---help---
1503	  Certain kernel features effectively disable kernel
1504	  linear 1 GB mappings (even if the CPU otherwise
1505	  supports them), so don't confuse the user by printing
1506	  that we have them enabled.
1507
1508config ARCH_HAS_MEM_ENCRYPT
1509	def_bool y
1510
1511config AMD_MEM_ENCRYPT
1512	bool "AMD Secure Memory Encryption (SME) support"
1513	depends on X86_64 && CPU_SUP_AMD
1514	---help---
1515	  Say yes to enable support for the encryption of system memory.
1516	  This requires an AMD processor that supports Secure Memory
1517	  Encryption (SME).
1518
1519config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1520	bool "Activate AMD Secure Memory Encryption (SME) by default"
1521	default y
1522	depends on AMD_MEM_ENCRYPT
1523	---help---
1524	  Say yes to have system memory encrypted by default if running on
1525	  an AMD processor that supports Secure Memory Encryption (SME).
1526
1527	  If set to Y, then the encryption of system memory can be
1528	  deactivated with the mem_encrypt=off command line option.
1529
1530	  If set to N, then the encryption of system memory can be
1531	  activated with the mem_encrypt=on command line option.
1532
1533config ARCH_USE_MEMREMAP_PROT
1534	def_bool y
1535	depends on AMD_MEM_ENCRYPT
1536
1537# Common NUMA Features
1538config NUMA
1539	bool "Numa Memory Allocation and Scheduler Support"
1540	depends on SMP
1541	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1542	default y if X86_BIGSMP
1543	---help---
1544	  Enable NUMA (Non Uniform Memory Access) support.
1545
1546	  The kernel will try to allocate memory used by a CPU on the
1547	  local memory controller of the CPU and add some more
1548	  NUMA awareness to the kernel.
1549
1550	  For 64-bit this is recommended if the system is Intel Core i7
1551	  (or later), AMD Opteron, or EM64T NUMA.
1552
1553	  For 32-bit this is only needed if you boot a 32-bit
1554	  kernel on a 64-bit NUMA platform.
1555
1556	  Otherwise, you should say N.
1557
1558config AMD_NUMA
1559	def_bool y
1560	prompt "Old style AMD Opteron NUMA detection"
1561	depends on X86_64 && NUMA && PCI
1562	---help---
1563	  Enable AMD NUMA node topology detection.  You should say Y here if
1564	  you have a multi processor AMD system. This uses an old method to
1565	  read the NUMA configuration directly from the builtin Northbridge
1566	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1567	  which also takes priority if both are compiled in.
1568
1569config X86_64_ACPI_NUMA
1570	def_bool y
1571	prompt "ACPI NUMA detection"
1572	depends on X86_64 && NUMA && ACPI && PCI
1573	select ACPI_NUMA
1574	---help---
1575	  Enable ACPI SRAT based node topology detection.
1576
1577# Some NUMA nodes have memory ranges that span
1578# other nodes.  Even though a pfn is valid and
1579# between a node's start and end pfns, it may not
1580# reside on that node.  See memmap_init_zone()
1581# for details.
1582config NODES_SPAN_OTHER_NODES
1583	def_bool y
1584	depends on X86_64_ACPI_NUMA
1585
1586config NUMA_EMU
1587	bool "NUMA emulation"
1588	depends on NUMA
1589	---help---
1590	  Enable NUMA emulation. A flat machine will be split
1591	  into virtual nodes when booted with "numa=fake=N", where N is the
1592	  number of nodes. This is only useful for debugging.
1593
1594config NODES_SHIFT
1595	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1596	range 1 10
1597	default "10" if MAXSMP
1598	default "6" if X86_64
1599	default "3"
1600	depends on NEED_MULTIPLE_NODES
1601	---help---
1602	  Specify the maximum number of NUMA Nodes available on the target
1603	  system.  Increases memory reserved to accommodate various tables.
1604
1605config ARCH_HAVE_MEMORY_PRESENT
1606	def_bool y
1607	depends on X86_32 && DISCONTIGMEM
1608
1609config NEED_NODE_MEMMAP_SIZE
1610	def_bool y
1611	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1612
1613config ARCH_FLATMEM_ENABLE
1614	def_bool y
1615	depends on X86_32 && !NUMA
1616
1617config ARCH_DISCONTIGMEM_ENABLE
1618	def_bool y
1619	depends on NUMA && X86_32
1620
1621config ARCH_DISCONTIGMEM_DEFAULT
1622	def_bool y
1623	depends on NUMA && X86_32
1624
1625config ARCH_SPARSEMEM_ENABLE
1626	def_bool y
1627	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1628	select SPARSEMEM_STATIC if X86_32
1629	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1630
1631config ARCH_SPARSEMEM_DEFAULT
1632	def_bool y
1633	depends on X86_64
1634
1635config ARCH_SELECT_MEMORY_MODEL
1636	def_bool y
1637	depends on ARCH_SPARSEMEM_ENABLE
1638
1639config ARCH_MEMORY_PROBE
1640	bool "Enable sysfs memory/probe interface"
1641	depends on X86_64 && MEMORY_HOTPLUG
1642	help
1643	  This option enables a sysfs memory/probe interface for testing.
1644	  See Documentation/memory-hotplug.txt for more information.
1645	  If you are unsure how to answer this question, answer N.
1646
1647config ARCH_PROC_KCORE_TEXT
1648	def_bool y
1649	depends on X86_64 && PROC_KCORE
1650
1651config ILLEGAL_POINTER_VALUE
1652       hex
1653       default 0 if X86_32
1654       default 0xdead000000000000 if X86_64
1655
1656source "mm/Kconfig"
1657
1658config X86_PMEM_LEGACY_DEVICE
1659	bool
1660
1661config X86_PMEM_LEGACY
1662	tristate "Support non-standard NVDIMMs and ADR protected memory"
1663	depends on PHYS_ADDR_T_64BIT
1664	depends on BLK_DEV
1665	select X86_PMEM_LEGACY_DEVICE
1666	select LIBNVDIMM
1667	help
1668	  Treat memory marked using the non-standard e820 type of 12 as used
1669	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1670	  The kernel will offer these regions to the 'pmem' driver so
1671	  they can be used for persistent storage.
1672
1673	  Say Y if unsure.
1674
1675config HIGHPTE
1676	bool "Allocate 3rd-level pagetables from highmem"
1677	depends on HIGHMEM
1678	---help---
1679	  The VM uses one page table entry for each page of physical memory.
1680	  For systems with a lot of RAM, this can be wasteful of precious
1681	  low memory.  Setting this option will put user-space page table
1682	  entries in high memory.
1683
1684config X86_CHECK_BIOS_CORRUPTION
1685	bool "Check for low memory corruption"
1686	---help---
1687	  Periodically check for memory corruption in low memory, which
1688	  is suspected to be caused by BIOS.  Even when enabled in the
1689	  configuration, it is disabled at runtime.  Enable it by
1690	  setting "memory_corruption_check=1" on the kernel command
1691	  line.  By default it scans the low 64k of memory every 60
1692	  seconds; see the memory_corruption_check_size and
1693	  memory_corruption_check_period parameters in
1694	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1695
1696	  When enabled with the default parameters, this option has
1697	  almost no overhead, as it reserves a relatively small amount
1698	  of memory and scans it infrequently.  It both detects corruption
1699	  and prevents it from affecting the running system.
1700
1701	  It is, however, intended as a diagnostic tool; if repeatable
1702	  BIOS-originated corruption always affects the same memory,
1703	  you can use memmap= to prevent the kernel from using that
1704	  memory.
1705
1706config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1707	bool "Set the default setting of memory_corruption_check"
1708	depends on X86_CHECK_BIOS_CORRUPTION
1709	default y
1710	---help---
1711	  Set whether the default state of memory_corruption_check is
1712	  on or off.
1713
1714config X86_RESERVE_LOW
1715	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1716	default 64
1717	range 4 640
1718	---help---
1719	  Specify the amount of low memory to reserve for the BIOS.
1720
1721	  The first page contains BIOS data structures that the kernel
1722	  must not use, so that page must always be reserved.
1723
1724	  By default we reserve the first 64K of physical RAM, as a
1725	  number of BIOSes are known to corrupt that memory range
1726	  during events such as suspend/resume or monitor cable
1727	  insertion, so it must not be used by the kernel.
1728
1729	  You can set this to 4 if you are absolutely sure that you
1730	  trust the BIOS to get all its memory reservations and usages
1731	  right.  If you know your BIOS have problems beyond the
1732	  default 64K area, you can set this to 640 to avoid using the
1733	  entire low memory range.
1734
1735	  If you have doubts about the BIOS (e.g. suspend/resume does
1736	  not work or there's kernel crashes after certain hardware
1737	  hotplug events) then you might want to enable
1738	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1739	  typical corruption patterns.
1740
1741	  Leave this to the default value of 64 if you are unsure.
1742
1743config MATH_EMULATION
1744	bool
1745	depends on MODIFY_LDT_SYSCALL
1746	prompt "Math emulation" if X86_32
1747	---help---
1748	  Linux can emulate a math coprocessor (used for floating point
1749	  operations) if you don't have one. 486DX and Pentium processors have
1750	  a math coprocessor built in, 486SX and 386 do not, unless you added
1751	  a 487DX or 387, respectively. (The messages during boot time can
1752	  give you some hints here ["man dmesg"].) Everyone needs either a
1753	  coprocessor or this emulation.
1754
1755	  If you don't have a math coprocessor, you need to say Y here; if you
1756	  say Y here even though you have a coprocessor, the coprocessor will
1757	  be used nevertheless. (This behavior can be changed with the kernel
1758	  command line option "no387", which comes handy if your coprocessor
1759	  is broken. Try "man bootparam" or see the documentation of your boot
1760	  loader (lilo or loadlin) about how to pass options to the kernel at
1761	  boot time.) This means that it is a good idea to say Y here if you
1762	  intend to use this kernel on different machines.
1763
1764	  More information about the internals of the Linux math coprocessor
1765	  emulation can be found in <file:arch/x86/math-emu/README>.
1766
1767	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1768	  kernel, it won't hurt.
1769
1770config MTRR
1771	def_bool y
1772	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1773	---help---
1774	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1775	  the Memory Type Range Registers (MTRRs) may be used to control
1776	  processor access to memory ranges. This is most useful if you have
1777	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1778	  allows bus write transfers to be combined into a larger transfer
1779	  before bursting over the PCI/AGP bus. This can increase performance
1780	  of image write operations 2.5 times or more. Saying Y here creates a
1781	  /proc/mtrr file which may be used to manipulate your processor's
1782	  MTRRs. Typically the X server should use this.
1783
1784	  This code has a reasonably generic interface so that similar
1785	  control registers on other processors can be easily supported
1786	  as well:
1787
1788	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1789	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1790	  these, the ARRs are used to emulate the MTRRs.
1791	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1792	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1793	  write-combining. All of these processors are supported by this code
1794	  and it makes sense to say Y here if you have one of them.
1795
1796	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1797	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1798	  can lead to all sorts of problems, so it's good to say Y here.
1799
1800	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1801	  just add about 9 KB to your kernel.
1802
1803	  See <file:Documentation/x86/mtrr.txt> for more information.
1804
1805config MTRR_SANITIZER
1806	def_bool y
1807	prompt "MTRR cleanup support"
1808	depends on MTRR
1809	---help---
1810	  Convert MTRR layout from continuous to discrete, so X drivers can
1811	  add writeback entries.
1812
1813	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1814	  The largest mtrr entry size for a continuous block can be set with
1815	  mtrr_chunk_size.
1816
1817	  If unsure, say Y.
1818
1819config MTRR_SANITIZER_ENABLE_DEFAULT
1820	int "MTRR cleanup enable value (0-1)"
1821	range 0 1
1822	default "0"
1823	depends on MTRR_SANITIZER
1824	---help---
1825	  Enable mtrr cleanup default value
1826
1827config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1828	int "MTRR cleanup spare reg num (0-7)"
1829	range 0 7
1830	default "1"
1831	depends on MTRR_SANITIZER
1832	---help---
1833	  mtrr cleanup spare entries default, it can be changed via
1834	  mtrr_spare_reg_nr=N on the kernel command line.
1835
1836config X86_PAT
1837	def_bool y
1838	prompt "x86 PAT support" if EXPERT
1839	depends on MTRR
1840	---help---
1841	  Use PAT attributes to setup page level cache control.
1842
1843	  PATs are the modern equivalents of MTRRs and are much more
1844	  flexible than MTRRs.
1845
1846	  Say N here if you see bootup problems (boot crash, boot hang,
1847	  spontaneous reboots) or a non-working video driver.
1848
1849	  If unsure, say Y.
1850
1851config ARCH_USES_PG_UNCACHED
1852	def_bool y
1853	depends on X86_PAT
1854
1855config ARCH_RANDOM
1856	def_bool y
1857	prompt "x86 architectural random number generator" if EXPERT
1858	---help---
1859	  Enable the x86 architectural RDRAND instruction
1860	  (Intel Bull Mountain technology) to generate random numbers.
1861	  If supported, this is a high bandwidth, cryptographically
1862	  secure hardware random number generator.
1863
1864config X86_SMAP
1865	def_bool y
1866	prompt "Supervisor Mode Access Prevention" if EXPERT
1867	---help---
1868	  Supervisor Mode Access Prevention (SMAP) is a security
1869	  feature in newer Intel processors.  There is a small
1870	  performance cost if this enabled and turned on; there is
1871	  also a small increase in the kernel size if this is enabled.
1872
1873	  If unsure, say Y.
1874
1875config X86_INTEL_UMIP
1876	def_bool y
1877	depends on CPU_SUP_INTEL
1878	prompt "Intel User Mode Instruction Prevention" if EXPERT
1879	---help---
1880	  The User Mode Instruction Prevention (UMIP) is a security
1881	  feature in newer Intel processors. If enabled, a general
1882	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1883	  or STR instructions are executed in user mode. These instructions
1884	  unnecessarily expose information about the hardware state.
1885
1886	  The vast majority of applications do not use these instructions.
1887	  For the very few that do, software emulation is provided in
1888	  specific cases in protected and virtual-8086 modes. Emulated
1889	  results are dummy.
1890
1891config X86_INTEL_MPX
1892	prompt "Intel MPX (Memory Protection Extensions)"
1893	def_bool n
1894	# Note: only available in 64-bit mode due to VMA flags shortage
1895	depends on CPU_SUP_INTEL && X86_64
1896	select ARCH_USES_HIGH_VMA_FLAGS
1897	---help---
1898	  MPX provides hardware features that can be used in
1899	  conjunction with compiler-instrumented code to check
1900	  memory references.  It is designed to detect buffer
1901	  overflow or underflow bugs.
1902
1903	  This option enables running applications which are
1904	  instrumented or otherwise use MPX.  It does not use MPX
1905	  itself inside the kernel or to protect the kernel
1906	  against bad memory references.
1907
1908	  Enabling this option will make the kernel larger:
1909	  ~8k of kernel text and 36 bytes of data on a 64-bit
1910	  defconfig.  It adds a long to the 'mm_struct' which
1911	  will increase the kernel memory overhead of each
1912	  process and adds some branches to paths used during
1913	  exec() and munmap().
1914
1915	  For details, see Documentation/x86/intel_mpx.txt
1916
1917	  If unsure, say N.
1918
1919config X86_INTEL_MEMORY_PROTECTION_KEYS
1920	prompt "Intel Memory Protection Keys"
1921	def_bool y
1922	# Note: only available in 64-bit mode
1923	depends on CPU_SUP_INTEL && X86_64
1924	select ARCH_USES_HIGH_VMA_FLAGS
1925	select ARCH_HAS_PKEYS
1926	---help---
1927	  Memory Protection Keys provides a mechanism for enforcing
1928	  page-based protections, but without requiring modification of the
1929	  page tables when an application changes protection domains.
1930
1931	  For details, see Documentation/x86/protection-keys.txt
1932
1933	  If unsure, say y.
1934
1935config EFI
1936	bool "EFI runtime service support"
1937	depends on ACPI
1938	select UCS2_STRING
1939	select EFI_RUNTIME_WRAPPERS
1940	---help---
1941	  This enables the kernel to use EFI runtime services that are
1942	  available (such as the EFI variable services).
1943
1944	  This option is only useful on systems that have EFI firmware.
1945	  In addition, you should use the latest ELILO loader available
1946	  at <http://elilo.sourceforge.net> in order to take advantage
1947	  of EFI runtime services. However, even with this option, the
1948	  resultant kernel should continue to boot on existing non-EFI
1949	  platforms.
1950
1951config EFI_STUB
1952       bool "EFI stub support"
1953       depends on EFI && !X86_USE_3DNOW
1954       select RELOCATABLE
1955       ---help---
1956          This kernel feature allows a bzImage to be loaded directly
1957	  by EFI firmware without the use of a bootloader.
1958
1959	  See Documentation/efi-stub.txt for more information.
1960
1961config EFI_MIXED
1962	bool "EFI mixed-mode support"
1963	depends on EFI_STUB && X86_64
1964	---help---
1965	   Enabling this feature allows a 64-bit kernel to be booted
1966	   on a 32-bit firmware, provided that your CPU supports 64-bit
1967	   mode.
1968
1969	   Note that it is not possible to boot a mixed-mode enabled
1970	   kernel via the EFI boot stub - a bootloader that supports
1971	   the EFI handover protocol must be used.
1972
1973	   If unsure, say N.
1974
1975config SECCOMP
1976	def_bool y
1977	prompt "Enable seccomp to safely compute untrusted bytecode"
1978	---help---
1979	  This kernel feature is useful for number crunching applications
1980	  that may need to compute untrusted bytecode during their
1981	  execution. By using pipes or other transports made available to
1982	  the process as file descriptors supporting the read/write
1983	  syscalls, it's possible to isolate those applications in
1984	  their own address space using seccomp. Once seccomp is
1985	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1986	  and the task is only allowed to execute a few safe syscalls
1987	  defined by each seccomp mode.
1988
1989	  If unsure, say Y. Only embedded should say N here.
1990
1991source kernel/Kconfig.hz
1992
1993config KEXEC
1994	bool "kexec system call"
1995	select KEXEC_CORE
1996	---help---
1997	  kexec is a system call that implements the ability to shutdown your
1998	  current kernel, and to start another kernel.  It is like a reboot
1999	  but it is independent of the system firmware.   And like a reboot
2000	  you can start any kernel with it, not just Linux.
2001
2002	  The name comes from the similarity to the exec system call.
2003
2004	  It is an ongoing process to be certain the hardware in a machine
2005	  is properly shutdown, so do not be surprised if this code does not
2006	  initially work for you.  As of this writing the exact hardware
2007	  interface is strongly in flux, so no good recommendation can be
2008	  made.
2009
2010config KEXEC_FILE
2011	bool "kexec file based system call"
2012	select KEXEC_CORE
2013	select BUILD_BIN2C
2014	depends on X86_64
2015	depends on CRYPTO=y
2016	depends on CRYPTO_SHA256=y
2017	---help---
2018	  This is new version of kexec system call. This system call is
2019	  file based and takes file descriptors as system call argument
2020	  for kernel and initramfs as opposed to list of segments as
2021	  accepted by previous system call.
2022
2023config KEXEC_VERIFY_SIG
2024	bool "Verify kernel signature during kexec_file_load() syscall"
2025	depends on KEXEC_FILE
2026	---help---
2027	  This option makes kernel signature verification mandatory for
2028	  the kexec_file_load() syscall.
2029
2030	  In addition to that option, you need to enable signature
2031	  verification for the corresponding kernel image type being
2032	  loaded in order for this to work.
2033
2034config KEXEC_BZIMAGE_VERIFY_SIG
2035	bool "Enable bzImage signature verification support"
2036	depends on KEXEC_VERIFY_SIG
2037	depends on SIGNED_PE_FILE_VERIFICATION
2038	select SYSTEM_TRUSTED_KEYRING
2039	---help---
2040	  Enable bzImage signature verification support.
2041
2042config CRASH_DUMP
2043	bool "kernel crash dumps"
2044	depends on X86_64 || (X86_32 && HIGHMEM)
2045	---help---
2046	  Generate crash dump after being started by kexec.
2047	  This should be normally only set in special crash dump kernels
2048	  which are loaded in the main kernel with kexec-tools into
2049	  a specially reserved region and then later executed after
2050	  a crash by kdump/kexec. The crash dump kernel must be compiled
2051	  to a memory address not used by the main kernel or BIOS using
2052	  PHYSICAL_START, or it must be built as a relocatable image
2053	  (CONFIG_RELOCATABLE=y).
2054	  For more details see Documentation/kdump/kdump.txt
2055
2056config KEXEC_JUMP
2057	bool "kexec jump"
2058	depends on KEXEC && HIBERNATION
2059	---help---
2060	  Jump between original kernel and kexeced kernel and invoke
2061	  code in physical address mode via KEXEC
2062
2063config PHYSICAL_START
2064	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2065	default "0x1000000"
2066	---help---
2067	  This gives the physical address where the kernel is loaded.
2068
2069	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2070	  bzImage will decompress itself to above physical address and
2071	  run from there. Otherwise, bzImage will run from the address where
2072	  it has been loaded by the boot loader and will ignore above physical
2073	  address.
2074
2075	  In normal kdump cases one does not have to set/change this option
2076	  as now bzImage can be compiled as a completely relocatable image
2077	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2078	  address. This option is mainly useful for the folks who don't want
2079	  to use a bzImage for capturing the crash dump and want to use a
2080	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2081	  to be specifically compiled to run from a specific memory area
2082	  (normally a reserved region) and this option comes handy.
2083
2084	  So if you are using bzImage for capturing the crash dump,
2085	  leave the value here unchanged to 0x1000000 and set
2086	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2087	  for capturing the crash dump change this value to start of
2088	  the reserved region.  In other words, it can be set based on
2089	  the "X" value as specified in the "crashkernel=YM@XM"
2090	  command line boot parameter passed to the panic-ed
2091	  kernel. Please take a look at Documentation/kdump/kdump.txt
2092	  for more details about crash dumps.
2093
2094	  Usage of bzImage for capturing the crash dump is recommended as
2095	  one does not have to build two kernels. Same kernel can be used
2096	  as production kernel and capture kernel. Above option should have
2097	  gone away after relocatable bzImage support is introduced. But it
2098	  is present because there are users out there who continue to use
2099	  vmlinux for dump capture. This option should go away down the
2100	  line.
2101
2102	  Don't change this unless you know what you are doing.
2103
2104config RELOCATABLE
2105	bool "Build a relocatable kernel"
2106	default y
2107	---help---
2108	  This builds a kernel image that retains relocation information
2109	  so it can be loaded someplace besides the default 1MB.
2110	  The relocations tend to make the kernel binary about 10% larger,
2111	  but are discarded at runtime.
2112
2113	  One use is for the kexec on panic case where the recovery kernel
2114	  must live at a different physical address than the primary
2115	  kernel.
2116
2117	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2118	  it has been loaded at and the compile time physical address
2119	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2120
2121config RANDOMIZE_BASE
2122	bool "Randomize the address of the kernel image (KASLR)"
2123	depends on RELOCATABLE
2124	default y
2125	---help---
2126	  In support of Kernel Address Space Layout Randomization (KASLR),
2127	  this randomizes the physical address at which the kernel image
2128	  is decompressed and the virtual address where the kernel
2129	  image is mapped, as a security feature that deters exploit
2130	  attempts relying on knowledge of the location of kernel
2131	  code internals.
2132
2133	  On 64-bit, the kernel physical and virtual addresses are
2134	  randomized separately. The physical address will be anywhere
2135	  between 16MB and the top of physical memory (up to 64TB). The
2136	  virtual address will be randomized from 16MB up to 1GB (9 bits
2137	  of entropy). Note that this also reduces the memory space
2138	  available to kernel modules from 1.5GB to 1GB.
2139
2140	  On 32-bit, the kernel physical and virtual addresses are
2141	  randomized together. They will be randomized from 16MB up to
2142	  512MB (8 bits of entropy).
2143
2144	  Entropy is generated using the RDRAND instruction if it is
2145	  supported. If RDTSC is supported, its value is mixed into
2146	  the entropy pool as well. If neither RDRAND nor RDTSC are
2147	  supported, then entropy is read from the i8254 timer. The
2148	  usable entropy is limited by the kernel being built using
2149	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2150	  minimum of 2MB. As a result, only 10 bits of entropy are
2151	  theoretically possible, but the implementations are further
2152	  limited due to memory layouts.
2153
2154	  If unsure, say Y.
2155
2156# Relocation on x86 needs some additional build support
2157config X86_NEED_RELOCS
2158	def_bool y
2159	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2160
2161config PHYSICAL_ALIGN
2162	hex "Alignment value to which kernel should be aligned"
2163	default "0x200000"
2164	range 0x2000 0x1000000 if X86_32
2165	range 0x200000 0x1000000 if X86_64
2166	---help---
2167	  This value puts the alignment restrictions on physical address
2168	  where kernel is loaded and run from. Kernel is compiled for an
2169	  address which meets above alignment restriction.
2170
2171	  If bootloader loads the kernel at a non-aligned address and
2172	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2173	  address aligned to above value and run from there.
2174
2175	  If bootloader loads the kernel at a non-aligned address and
2176	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2177	  load address and decompress itself to the address it has been
2178	  compiled for and run from there. The address for which kernel is
2179	  compiled already meets above alignment restrictions. Hence the
2180	  end result is that kernel runs from a physical address meeting
2181	  above alignment restrictions.
2182
2183	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2184	  this value must be a multiple of 0x200000.
2185
2186	  Don't change this unless you know what you are doing.
2187
2188config RANDOMIZE_MEMORY
2189	bool "Randomize the kernel memory sections"
2190	depends on X86_64
2191	depends on RANDOMIZE_BASE
2192	default RANDOMIZE_BASE
2193	---help---
2194	   Randomizes the base virtual address of kernel memory sections
2195	   (physical memory mapping, vmalloc & vmemmap). This security feature
2196	   makes exploits relying on predictable memory locations less reliable.
2197
2198	   The order of allocations remains unchanged. Entropy is generated in
2199	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2200	   configuration have in average 30,000 different possible virtual
2201	   addresses for each memory section.
2202
2203	   If unsure, say Y.
2204
2205config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2206	hex "Physical memory mapping padding" if EXPERT
2207	depends on RANDOMIZE_MEMORY
2208	default "0xa" if MEMORY_HOTPLUG
2209	default "0x0"
2210	range 0x1 0x40 if MEMORY_HOTPLUG
2211	range 0x0 0x40
2212	---help---
2213	   Define the padding in terabytes added to the existing physical
2214	   memory size during kernel memory randomization. It is useful
2215	   for memory hotplug support but reduces the entropy available for
2216	   address randomization.
2217
2218	   If unsure, leave at the default value.
2219
2220config HOTPLUG_CPU
2221	bool "Support for hot-pluggable CPUs"
2222	depends on SMP
2223	---help---
2224	  Say Y here to allow turning CPUs off and on. CPUs can be
2225	  controlled through /sys/devices/system/cpu.
2226	  ( Note: power management support will enable this option
2227	    automatically on SMP systems. )
2228	  Say N if you want to disable CPU hotplug.
2229
2230config BOOTPARAM_HOTPLUG_CPU0
2231	bool "Set default setting of cpu0_hotpluggable"
2232	default n
2233	depends on HOTPLUG_CPU
2234	---help---
2235	  Set whether default state of cpu0_hotpluggable is on or off.
2236
2237	  Say Y here to enable CPU0 hotplug by default. If this switch
2238	  is turned on, there is no need to give cpu0_hotplug kernel
2239	  parameter and the CPU0 hotplug feature is enabled by default.
2240
2241	  Please note: there are two known CPU0 dependencies if you want
2242	  to enable the CPU0 hotplug feature either by this switch or by
2243	  cpu0_hotplug kernel parameter.
2244
2245	  First, resume from hibernate or suspend always starts from CPU0.
2246	  So hibernate and suspend are prevented if CPU0 is offline.
2247
2248	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2249	  offline if any interrupt can not migrate out of CPU0. There may
2250	  be other CPU0 dependencies.
2251
2252	  Please make sure the dependencies are under your control before
2253	  you enable this feature.
2254
2255	  Say N if you don't want to enable CPU0 hotplug feature by default.
2256	  You still can enable the CPU0 hotplug feature at boot by kernel
2257	  parameter cpu0_hotplug.
2258
2259config DEBUG_HOTPLUG_CPU0
2260	def_bool n
2261	prompt "Debug CPU0 hotplug"
2262	depends on HOTPLUG_CPU
2263	---help---
2264	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2265	  soon as possible and boots up userspace with CPU0 offlined. User
2266	  can online CPU0 back after boot time.
2267
2268	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2269	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2270	  compilation or giving cpu0_hotplug kernel parameter at boot.
2271
2272	  If unsure, say N.
2273
2274config COMPAT_VDSO
2275	def_bool n
2276	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2277	depends on COMPAT_32
2278	---help---
2279	  Certain buggy versions of glibc will crash if they are
2280	  presented with a 32-bit vDSO that is not mapped at the address
2281	  indicated in its segment table.
2282
2283	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2284	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2285	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2286	  the only released version with the bug, but OpenSUSE 9
2287	  contains a buggy "glibc 2.3.2".
2288
2289	  The symptom of the bug is that everything crashes on startup, saying:
2290	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2291
2292	  Saying Y here changes the default value of the vdso32 boot
2293	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2294	  This works around the glibc bug but hurts performance.
2295
2296	  If unsure, say N: if you are compiling your own kernel, you
2297	  are unlikely to be using a buggy version of glibc.
2298
2299choice
2300	prompt "vsyscall table for legacy applications"
2301	depends on X86_64
2302	default LEGACY_VSYSCALL_EMULATE
2303	help
2304	  Legacy user code that does not know how to find the vDSO expects
2305	  to be able to issue three syscalls by calling fixed addresses in
2306	  kernel space. Since this location is not randomized with ASLR,
2307	  it can be used to assist security vulnerability exploitation.
2308
2309	  This setting can be changed at boot time via the kernel command
2310	  line parameter vsyscall=[native|emulate|none].
2311
2312	  On a system with recent enough glibc (2.14 or newer) and no
2313	  static binaries, you can say None without a performance penalty
2314	  to improve security.
2315
2316	  If unsure, select "Emulate".
2317
2318	config LEGACY_VSYSCALL_NATIVE
2319		bool "Native"
2320		help
2321		  Actual executable code is located in the fixed vsyscall
2322		  address mapping, implementing time() efficiently. Since
2323		  this makes the mapping executable, it can be used during
2324		  security vulnerability exploitation (traditionally as
2325		  ROP gadgets). This configuration is not recommended.
2326
2327	config LEGACY_VSYSCALL_EMULATE
2328		bool "Emulate"
2329		help
2330		  The kernel traps and emulates calls into the fixed
2331		  vsyscall address mapping. This makes the mapping
2332		  non-executable, but it still contains known contents,
2333		  which could be used in certain rare security vulnerability
2334		  exploits. This configuration is recommended when userspace
2335		  still uses the vsyscall area.
2336
2337	config LEGACY_VSYSCALL_NONE
2338		bool "None"
2339		help
2340		  There will be no vsyscall mapping at all. This will
2341		  eliminate any risk of ASLR bypass due to the vsyscall
2342		  fixed address mapping. Attempts to use the vsyscalls
2343		  will be reported to dmesg, so that either old or
2344		  malicious userspace programs can be identified.
2345
2346endchoice
2347
2348config CMDLINE_BOOL
2349	bool "Built-in kernel command line"
2350	---help---
2351	  Allow for specifying boot arguments to the kernel at
2352	  build time.  On some systems (e.g. embedded ones), it is
2353	  necessary or convenient to provide some or all of the
2354	  kernel boot arguments with the kernel itself (that is,
2355	  to not rely on the boot loader to provide them.)
2356
2357	  To compile command line arguments into the kernel,
2358	  set this option to 'Y', then fill in the
2359	  boot arguments in CONFIG_CMDLINE.
2360
2361	  Systems with fully functional boot loaders (i.e. non-embedded)
2362	  should leave this option set to 'N'.
2363
2364config CMDLINE
2365	string "Built-in kernel command string"
2366	depends on CMDLINE_BOOL
2367	default ""
2368	---help---
2369	  Enter arguments here that should be compiled into the kernel
2370	  image and used at boot time.  If the boot loader provides a
2371	  command line at boot time, it is appended to this string to
2372	  form the full kernel command line, when the system boots.
2373
2374	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2375	  change this behavior.
2376
2377	  In most cases, the command line (whether built-in or provided
2378	  by the boot loader) should specify the device for the root
2379	  file system.
2380
2381config CMDLINE_OVERRIDE
2382	bool "Built-in command line overrides boot loader arguments"
2383	depends on CMDLINE_BOOL
2384	---help---
2385	  Set this option to 'Y' to have the kernel ignore the boot loader
2386	  command line, and use ONLY the built-in command line.
2387
2388	  This is used to work around broken boot loaders.  This should
2389	  be set to 'N' under normal conditions.
2390
2391config MODIFY_LDT_SYSCALL
2392	bool "Enable the LDT (local descriptor table)" if EXPERT
2393	default y
2394	---help---
2395	  Linux can allow user programs to install a per-process x86
2396	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2397	  call.  This is required to run 16-bit or segmented code such as
2398	  DOSEMU or some Wine programs.  It is also used by some very old
2399	  threading libraries.
2400
2401	  Enabling this feature adds a small amount of overhead to
2402	  context switches and increases the low-level kernel attack
2403	  surface.  Disabling it removes the modify_ldt(2) system call.
2404
2405	  Saying 'N' here may make sense for embedded or server kernels.
2406
2407source "kernel/livepatch/Kconfig"
2408
2409endmenu
2410
2411config ARCH_HAS_ADD_PAGES
2412	def_bool y
2413	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2414
2415config ARCH_ENABLE_MEMORY_HOTPLUG
2416	def_bool y
2417	depends on X86_64 || (X86_32 && HIGHMEM)
2418
2419config ARCH_ENABLE_MEMORY_HOTREMOVE
2420	def_bool y
2421	depends on MEMORY_HOTPLUG
2422
2423config USE_PERCPU_NUMA_NODE_ID
2424	def_bool y
2425	depends on NUMA
2426
2427config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2428	def_bool y
2429	depends on X86_64 || X86_PAE
2430
2431config ARCH_ENABLE_HUGEPAGE_MIGRATION
2432	def_bool y
2433	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2434
2435config ARCH_ENABLE_THP_MIGRATION
2436	def_bool y
2437	depends on X86_64 && TRANSPARENT_HUGEPAGE
2438
2439menu "Power management and ACPI options"
2440
2441config ARCH_HIBERNATION_HEADER
2442	def_bool y
2443	depends on X86_64 && HIBERNATION
2444
2445source "kernel/power/Kconfig"
2446
2447source "drivers/acpi/Kconfig"
2448
2449source "drivers/sfi/Kconfig"
2450
2451config X86_APM_BOOT
2452	def_bool y
2453	depends on APM
2454
2455menuconfig APM
2456	tristate "APM (Advanced Power Management) BIOS support"
2457	depends on X86_32 && PM_SLEEP
2458	---help---
2459	  APM is a BIOS specification for saving power using several different
2460	  techniques. This is mostly useful for battery powered laptops with
2461	  APM compliant BIOSes. If you say Y here, the system time will be
2462	  reset after a RESUME operation, the /proc/apm device will provide
2463	  battery status information, and user-space programs will receive
2464	  notification of APM "events" (e.g. battery status change).
2465
2466	  If you select "Y" here, you can disable actual use of the APM
2467	  BIOS by passing the "apm=off" option to the kernel at boot time.
2468
2469	  Note that the APM support is almost completely disabled for
2470	  machines with more than one CPU.
2471
2472	  In order to use APM, you will need supporting software. For location
2473	  and more information, read <file:Documentation/power/apm-acpi.txt>
2474	  and the Battery Powered Linux mini-HOWTO, available from
2475	  <http://www.tldp.org/docs.html#howto>.
2476
2477	  This driver does not spin down disk drives (see the hdparm(8)
2478	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2479	  VESA-compliant "green" monitors.
2480
2481	  This driver does not support the TI 4000M TravelMate and the ACER
2482	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2483	  desktop machines also don't have compliant BIOSes, and this driver
2484	  may cause those machines to panic during the boot phase.
2485
2486	  Generally, if you don't have a battery in your machine, there isn't
2487	  much point in using this driver and you should say N. If you get
2488	  random kernel OOPSes or reboots that don't seem to be related to
2489	  anything, try disabling/enabling this option (or disabling/enabling
2490	  APM in your BIOS).
2491
2492	  Some other things you should try when experiencing seemingly random,
2493	  "weird" problems:
2494
2495	  1) make sure that you have enough swap space and that it is
2496	  enabled.
2497	  2) pass the "no-hlt" option to the kernel
2498	  3) switch on floating point emulation in the kernel and pass
2499	  the "no387" option to the kernel
2500	  4) pass the "floppy=nodma" option to the kernel
2501	  5) pass the "mem=4M" option to the kernel (thereby disabling
2502	  all but the first 4 MB of RAM)
2503	  6) make sure that the CPU is not over clocked.
2504	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2505	  8) disable the cache from your BIOS settings
2506	  9) install a fan for the video card or exchange video RAM
2507	  10) install a better fan for the CPU
2508	  11) exchange RAM chips
2509	  12) exchange the motherboard.
2510
2511	  To compile this driver as a module, choose M here: the
2512	  module will be called apm.
2513
2514if APM
2515
2516config APM_IGNORE_USER_SUSPEND
2517	bool "Ignore USER SUSPEND"
2518	---help---
2519	  This option will ignore USER SUSPEND requests. On machines with a
2520	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2521	  series notebooks, it is necessary to say Y because of a BIOS bug.
2522
2523config APM_DO_ENABLE
2524	bool "Enable PM at boot time"
2525	---help---
2526	  Enable APM features at boot time. From page 36 of the APM BIOS
2527	  specification: "When disabled, the APM BIOS does not automatically
2528	  power manage devices, enter the Standby State, enter the Suspend
2529	  State, or take power saving steps in response to CPU Idle calls."
2530	  This driver will make CPU Idle calls when Linux is idle (unless this
2531	  feature is turned off -- see "Do CPU IDLE calls", below). This
2532	  should always save battery power, but more complicated APM features
2533	  will be dependent on your BIOS implementation. You may need to turn
2534	  this option off if your computer hangs at boot time when using APM
2535	  support, or if it beeps continuously instead of suspending. Turn
2536	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2537	  T400CDT. This is off by default since most machines do fine without
2538	  this feature.
2539
2540config APM_CPU_IDLE
2541	depends on CPU_IDLE
2542	bool "Make CPU Idle calls when idle"
2543	---help---
2544	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2545	  On some machines, this can activate improved power savings, such as
2546	  a slowed CPU clock rate, when the machine is idle. These idle calls
2547	  are made after the idle loop has run for some length of time (e.g.,
2548	  333 mS). On some machines, this will cause a hang at boot time or
2549	  whenever the CPU becomes idle. (On machines with more than one CPU,
2550	  this option does nothing.)
2551
2552config APM_DISPLAY_BLANK
2553	bool "Enable console blanking using APM"
2554	---help---
2555	  Enable console blanking using the APM. Some laptops can use this to
2556	  turn off the LCD backlight when the screen blanker of the Linux
2557	  virtual console blanks the screen. Note that this is only used by
2558	  the virtual console screen blanker, and won't turn off the backlight
2559	  when using the X Window system. This also doesn't have anything to
2560	  do with your VESA-compliant power-saving monitor. Further, this
2561	  option doesn't work for all laptops -- it might not turn off your
2562	  backlight at all, or it might print a lot of errors to the console,
2563	  especially if you are using gpm.
2564
2565config APM_ALLOW_INTS
2566	bool "Allow interrupts during APM BIOS calls"
2567	---help---
2568	  Normally we disable external interrupts while we are making calls to
2569	  the APM BIOS as a measure to lessen the effects of a badly behaving
2570	  BIOS implementation.  The BIOS should reenable interrupts if it
2571	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2572	  many of the newer IBM Thinkpads.  If you experience hangs when you
2573	  suspend, try setting this to Y.  Otherwise, say N.
2574
2575endif # APM
2576
2577source "drivers/cpufreq/Kconfig"
2578
2579source "drivers/cpuidle/Kconfig"
2580
2581source "drivers/idle/Kconfig"
2582
2583endmenu
2584
2585
2586menu "Bus options (PCI etc.)"
2587
2588config PCI
2589	bool "PCI support"
2590	default y
2591	---help---
2592	  Find out whether you have a PCI motherboard. PCI is the name of a
2593	  bus system, i.e. the way the CPU talks to the other stuff inside
2594	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2595	  VESA. If you have PCI, say Y, otherwise N.
2596
2597choice
2598	prompt "PCI access mode"
2599	depends on X86_32 && PCI
2600	default PCI_GOANY
2601	---help---
2602	  On PCI systems, the BIOS can be used to detect the PCI devices and
2603	  determine their configuration. However, some old PCI motherboards
2604	  have BIOS bugs and may crash if this is done. Also, some embedded
2605	  PCI-based systems don't have any BIOS at all. Linux can also try to
2606	  detect the PCI hardware directly without using the BIOS.
2607
2608	  With this option, you can specify how Linux should detect the
2609	  PCI devices. If you choose "BIOS", the BIOS will be used,
2610	  if you choose "Direct", the BIOS won't be used, and if you
2611	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2612	  If you choose "Any", the kernel will try MMCONFIG, then the
2613	  direct access method and falls back to the BIOS if that doesn't
2614	  work. If unsure, go with the default, which is "Any".
2615
2616config PCI_GOBIOS
2617	bool "BIOS"
2618
2619config PCI_GOMMCONFIG
2620	bool "MMConfig"
2621
2622config PCI_GODIRECT
2623	bool "Direct"
2624
2625config PCI_GOOLPC
2626	bool "OLPC XO-1"
2627	depends on OLPC
2628
2629config PCI_GOANY
2630	bool "Any"
2631
2632endchoice
2633
2634config PCI_BIOS
2635	def_bool y
2636	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2637
2638# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2639config PCI_DIRECT
2640	def_bool y
2641	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2642
2643config PCI_MMCONFIG
2644	def_bool y
2645	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2646
2647config PCI_OLPC
2648	def_bool y
2649	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2650
2651config PCI_XEN
2652	def_bool y
2653	depends on PCI && XEN
2654	select SWIOTLB_XEN
2655
2656config PCI_DOMAINS
2657	def_bool y
2658	depends on PCI
2659
2660config PCI_MMCONFIG
2661	bool "Support mmconfig PCI config space access"
2662	depends on X86_64 && PCI && ACPI
2663
2664config PCI_CNB20LE_QUIRK
2665	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2666	depends on PCI
2667	help
2668	  Read the PCI windows out of the CNB20LE host bridge. This allows
2669	  PCI hotplug to work on systems with the CNB20LE chipset which do
2670	  not have ACPI.
2671
2672	  There's no public spec for this chipset, and this functionality
2673	  is known to be incomplete.
2674
2675	  You should say N unless you know you need this.
2676
2677source "drivers/pci/Kconfig"
2678
2679config ISA_BUS
2680	bool "ISA-style bus support on modern systems" if EXPERT
2681	select ISA_BUS_API
2682	help
2683	  Enables ISA-style drivers on modern systems. This is necessary to
2684	  support PC/104 devices on X86_64 platforms.
2685
2686	  If unsure, say N.
2687
2688# x86_64 have no ISA slots, but can have ISA-style DMA.
2689config ISA_DMA_API
2690	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2691	default y
2692	help
2693	  Enables ISA-style DMA support for devices requiring such controllers.
2694	  If unsure, say Y.
2695
2696if X86_32
2697
2698config ISA
2699	bool "ISA support"
2700	---help---
2701	  Find out whether you have ISA slots on your motherboard.  ISA is the
2702	  name of a bus system, i.e. the way the CPU talks to the other stuff
2703	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2704	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2705	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2706
2707config EISA
2708	bool "EISA support"
2709	depends on ISA
2710	---help---
2711	  The Extended Industry Standard Architecture (EISA) bus was
2712	  developed as an open alternative to the IBM MicroChannel bus.
2713
2714	  The EISA bus provided some of the features of the IBM MicroChannel
2715	  bus while maintaining backward compatibility with cards made for
2716	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2717	  1995 when it was made obsolete by the PCI bus.
2718
2719	  Say Y here if you are building a kernel for an EISA-based machine.
2720
2721	  Otherwise, say N.
2722
2723source "drivers/eisa/Kconfig"
2724
2725config SCx200
2726	tristate "NatSemi SCx200 support"
2727	---help---
2728	  This provides basic support for National Semiconductor's
2729	  (now AMD's) Geode processors.  The driver probes for the
2730	  PCI-IDs of several on-chip devices, so its a good dependency
2731	  for other scx200_* drivers.
2732
2733	  If compiled as a module, the driver is named scx200.
2734
2735config SCx200HR_TIMER
2736	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2737	depends on SCx200
2738	default y
2739	---help---
2740	  This driver provides a clocksource built upon the on-chip
2741	  27MHz high-resolution timer.  Its also a workaround for
2742	  NSC Geode SC-1100's buggy TSC, which loses time when the
2743	  processor goes idle (as is done by the scheduler).  The
2744	  other workaround is idle=poll boot option.
2745
2746config OLPC
2747	bool "One Laptop Per Child support"
2748	depends on !X86_PAE
2749	select GPIOLIB
2750	select OF
2751	select OF_PROMTREE
2752	select IRQ_DOMAIN
2753	---help---
2754	  Add support for detecting the unique features of the OLPC
2755	  XO hardware.
2756
2757config OLPC_XO1_PM
2758	bool "OLPC XO-1 Power Management"
2759	depends on OLPC && MFD_CS5535 && PM_SLEEP
2760	select MFD_CORE
2761	---help---
2762	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2763
2764config OLPC_XO1_RTC
2765	bool "OLPC XO-1 Real Time Clock"
2766	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2767	---help---
2768	  Add support for the XO-1 real time clock, which can be used as a
2769	  programmable wakeup source.
2770
2771config OLPC_XO1_SCI
2772	bool "OLPC XO-1 SCI extras"
2773	depends on OLPC && OLPC_XO1_PM
2774	depends on INPUT=y
2775	select POWER_SUPPLY
2776	select GPIO_CS5535
2777	select MFD_CORE
2778	---help---
2779	  Add support for SCI-based features of the OLPC XO-1 laptop:
2780	   - EC-driven system wakeups
2781	   - Power button
2782	   - Ebook switch
2783	   - Lid switch
2784	   - AC adapter status updates
2785	   - Battery status updates
2786
2787config OLPC_XO15_SCI
2788	bool "OLPC XO-1.5 SCI extras"
2789	depends on OLPC && ACPI
2790	select POWER_SUPPLY
2791	---help---
2792	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2793	   - EC-driven system wakeups
2794	   - AC adapter status updates
2795	   - Battery status updates
2796
2797config ALIX
2798	bool "PCEngines ALIX System Support (LED setup)"
2799	select GPIOLIB
2800	---help---
2801	  This option enables system support for the PCEngines ALIX.
2802	  At present this just sets up LEDs for GPIO control on
2803	  ALIX2/3/6 boards.  However, other system specific setup should
2804	  get added here.
2805
2806	  Note: You must still enable the drivers for GPIO and LED support
2807	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2808
2809	  Note: You have to set alix.force=1 for boards with Award BIOS.
2810
2811config NET5501
2812	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2813	select GPIOLIB
2814	---help---
2815	  This option enables system support for the Soekris Engineering net5501.
2816
2817config GEOS
2818	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2819	select GPIOLIB
2820	depends on DMI
2821	---help---
2822	  This option enables system support for the Traverse Technologies GEOS.
2823
2824config TS5500
2825	bool "Technologic Systems TS-5500 platform support"
2826	depends on MELAN
2827	select CHECK_SIGNATURE
2828	select NEW_LEDS
2829	select LEDS_CLASS
2830	---help---
2831	  This option enables system support for the Technologic Systems TS-5500.
2832
2833endif # X86_32
2834
2835config AMD_NB
2836	def_bool y
2837	depends on CPU_SUP_AMD && PCI
2838
2839source "drivers/pcmcia/Kconfig"
2840
2841config RAPIDIO
2842	tristate "RapidIO support"
2843	depends on PCI
2844	default n
2845	help
2846	  If enabled this option will include drivers and the core
2847	  infrastructure code to support RapidIO interconnect devices.
2848
2849source "drivers/rapidio/Kconfig"
2850
2851config X86_SYSFB
2852	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2853	help
2854	  Firmwares often provide initial graphics framebuffers so the BIOS,
2855	  bootloader or kernel can show basic video-output during boot for
2856	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2857	  Extensions and EFI-framebuffers for this, which are mostly limited
2858	  to x86.
2859	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2860	  framebuffers so the new generic system-framebuffer drivers can be
2861	  used on x86. If the framebuffer is not compatible with the generic
2862	  modes, it is adverticed as fallback platform framebuffer so legacy
2863	  drivers like efifb, vesafb and uvesafb can pick it up.
2864	  If this option is not selected, all system framebuffers are always
2865	  marked as fallback platform framebuffers as usual.
2866
2867	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2868	  not be able to pick up generic system framebuffers if this option
2869	  is selected. You are highly encouraged to enable simplefb as
2870	  replacement if you select this option. simplefb can correctly deal
2871	  with generic system framebuffers. But you should still keep vesafb
2872	  and others enabled as fallback if a system framebuffer is
2873	  incompatible with simplefb.
2874
2875	  If unsure, say Y.
2876
2877endmenu
2878
2879
2880menu "Executable file formats / Emulations"
2881
2882source "fs/Kconfig.binfmt"
2883
2884config IA32_EMULATION
2885	bool "IA32 Emulation"
2886	depends on X86_64
2887	select ARCH_WANT_OLD_COMPAT_IPC
2888	select BINFMT_ELF
2889	select COMPAT_BINFMT_ELF
2890	select COMPAT_OLD_SIGACTION
2891	---help---
2892	  Include code to run legacy 32-bit programs under a
2893	  64-bit kernel. You should likely turn this on, unless you're
2894	  100% sure that you don't have any 32-bit programs left.
2895
2896config IA32_AOUT
2897	tristate "IA32 a.out support"
2898	depends on IA32_EMULATION
2899	---help---
2900	  Support old a.out binaries in the 32bit emulation.
2901
2902config X86_X32
2903	bool "x32 ABI for 64-bit mode"
2904	depends on X86_64
2905	---help---
2906	  Include code to run binaries for the x32 native 32-bit ABI
2907	  for 64-bit processors.  An x32 process gets access to the
2908	  full 64-bit register file and wide data path while leaving
2909	  pointers at 32 bits for smaller memory footprint.
2910
2911	  You will need a recent binutils (2.22 or later) with
2912	  elf32_x86_64 support enabled to compile a kernel with this
2913	  option set.
2914
2915config COMPAT_32
2916	def_bool y
2917	depends on IA32_EMULATION || X86_32
2918	select HAVE_UID16
2919	select OLD_SIGSUSPEND3
2920
2921config COMPAT
2922	def_bool y
2923	depends on IA32_EMULATION || X86_X32
2924
2925if COMPAT
2926config COMPAT_FOR_U64_ALIGNMENT
2927	def_bool y
2928
2929config SYSVIPC_COMPAT
2930	def_bool y
2931	depends on SYSVIPC
2932endif
2933
2934endmenu
2935
2936
2937config HAVE_ATOMIC_IOMAP
2938	def_bool y
2939	depends on X86_32
2940
2941config X86_DEV_DMA_OPS
2942	bool
2943	depends on X86_64 || STA2X11
2944
2945config X86_DMA_REMAP
2946	bool
2947	depends on STA2X11
2948
2949config HAVE_GENERIC_GUP
2950	def_bool y
2951
2952source "net/Kconfig"
2953
2954source "drivers/Kconfig"
2955
2956source "drivers/firmware/Kconfig"
2957
2958source "fs/Kconfig"
2959
2960source "arch/x86/Kconfig.debug"
2961
2962source "security/Kconfig"
2963
2964source "crypto/Kconfig"
2965
2966source "arch/x86/kvm/Kconfig"
2967
2968source "lib/Kconfig"
2969