xref: /openbmc/linux/arch/x86/Kconfig (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
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_MEMBARRIER_SYNC_CORE
58	select ARCH_HAS_PMEM_API		if X86_64
59	select ARCH_HAS_REFCOUNT
60	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
61	select ARCH_HAS_SET_MEMORY
62	select ARCH_HAS_SG_CHAIN
63	select ARCH_HAS_STRICT_KERNEL_RWX
64	select ARCH_HAS_STRICT_MODULE_RWX
65	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
66	select ARCH_HAS_UBSAN_SANITIZE_ALL
67	select ARCH_HAS_ZONE_DEVICE		if X86_64
68	select ARCH_HAVE_NMI_SAFE_CMPXCHG
69	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
70	select ARCH_MIGHT_HAVE_PC_PARPORT
71	select ARCH_MIGHT_HAVE_PC_SERIO
72	select ARCH_SUPPORTS_ATOMIC_RMW
73	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
74	select ARCH_USE_BUILTIN_BSWAP
75	select ARCH_USE_QUEUED_RWLOCKS
76	select ARCH_USE_QUEUED_SPINLOCKS
77	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
78	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
79	select ARCH_WANTS_THP_SWAP		if X86_64
80	select BUILDTIME_EXTABLE_SORT
81	select CLKEVT_I8253
82	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
83	select CLOCKSOURCE_WATCHDOG
84	select DCACHE_WORD_ACCESS
85	select DMA_DIRECT_OPS
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_X2APIC
397	bool "Support x2apic"
398	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
399	---help---
400	  This enables x2apic support on CPUs that have this feature.
401
402	  This allows 32-bit apic IDs (so it can support very large systems),
403	  and accesses the local apic via MSRs not via mmio.
404
405	  If you don't know what to do here, say N.
406
407config X86_MPPARSE
408	bool "Enable MPS table" if ACPI || SFI
409	default y
410	depends on X86_LOCAL_APIC
411	---help---
412	  For old smp systems that do not have proper acpi support. Newer systems
413	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
414
415config GOLDFISH
416       def_bool y
417       depends on X86_GOLDFISH
418
419config RETPOLINE
420	bool "Avoid speculative indirect branches in kernel"
421	default y
422	select STACK_VALIDATION if HAVE_STACK_VALIDATION
423	help
424	  Compile kernel with the retpoline compiler options to guard against
425	  kernel-to-user data leaks by avoiding speculative indirect
426	  branches. Requires a compiler with -mindirect-branch=thunk-extern
427	  support for full protection. The kernel may run slower.
428
429	  Without compiler support, at least indirect branches in assembler
430	  code are eliminated. Since this includes the syscall entry path,
431	  it is not entirely pointless.
432
433config INTEL_RDT
434	bool "Intel Resource Director Technology support"
435	default n
436	depends on X86 && CPU_SUP_INTEL
437	select KERNFS
438	help
439	  Select to enable resource allocation and monitoring which are
440	  sub-features of Intel Resource Director Technology(RDT). More
441	  information about RDT can be found in the Intel x86
442	  Architecture Software Developer Manual.
443
444	  Say N if unsure.
445
446if X86_32
447config X86_BIGSMP
448	bool "Support for big SMP systems with more than 8 CPUs"
449	depends on SMP
450	---help---
451	  This option is needed for the systems that have more than 8 CPUs
452
453config X86_EXTENDED_PLATFORM
454	bool "Support for extended (non-PC) x86 platforms"
455	default y
456	---help---
457	  If you disable this option then the kernel will only support
458	  standard PC platforms. (which covers the vast majority of
459	  systems out there.)
460
461	  If you enable this option then you'll be able to select support
462	  for the following (non-PC) 32 bit x86 platforms:
463		Goldfish (Android emulator)
464		AMD Elan
465		RDC R-321x SoC
466		SGI 320/540 (Visual Workstation)
467		STA2X11-based (e.g. Northville)
468		Moorestown MID devices
469
470	  If you have one of these systems, or if you want to build a
471	  generic distribution kernel, say Y here - otherwise say N.
472endif
473
474if X86_64
475config X86_EXTENDED_PLATFORM
476	bool "Support for extended (non-PC) x86 platforms"
477	default y
478	---help---
479	  If you disable this option then the kernel will only support
480	  standard PC platforms. (which covers the vast majority of
481	  systems out there.)
482
483	  If you enable this option then you'll be able to select support
484	  for the following (non-PC) 64 bit x86 platforms:
485		Numascale NumaChip
486		ScaleMP vSMP
487		SGI Ultraviolet
488
489	  If you have one of these systems, or if you want to build a
490	  generic distribution kernel, say Y here - otherwise say N.
491endif
492# This is an alphabetically sorted list of 64 bit extended platforms
493# Please maintain the alphabetic order if and when there are additions
494config X86_NUMACHIP
495	bool "Numascale NumaChip"
496	depends on X86_64
497	depends on X86_EXTENDED_PLATFORM
498	depends on NUMA
499	depends on SMP
500	depends on X86_X2APIC
501	depends on PCI_MMCONFIG
502	---help---
503	  Adds support for Numascale NumaChip large-SMP systems. Needed to
504	  enable more than ~168 cores.
505	  If you don't have one of these, you should say N here.
506
507config X86_VSMP
508	bool "ScaleMP vSMP"
509	select HYPERVISOR_GUEST
510	select PARAVIRT
511	depends on X86_64 && PCI
512	depends on X86_EXTENDED_PLATFORM
513	depends on SMP
514	---help---
515	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
516	  supposed to run on these EM64T-based machines.  Only choose this option
517	  if you have one of these machines.
518
519config X86_UV
520	bool "SGI Ultraviolet"
521	depends on X86_64
522	depends on X86_EXTENDED_PLATFORM
523	depends on NUMA
524	depends on EFI
525	depends on X86_X2APIC
526	depends on PCI
527	---help---
528	  This option is needed in order to support SGI Ultraviolet systems.
529	  If you don't have one of these, you should say N here.
530
531# Following is an alphabetically sorted list of 32 bit extended platforms
532# Please maintain the alphabetic order if and when there are additions
533
534config X86_GOLDFISH
535       bool "Goldfish (Virtual Platform)"
536       depends on X86_EXTENDED_PLATFORM
537       ---help---
538	 Enable support for the Goldfish virtual platform used primarily
539	 for Android development. Unless you are building for the Android
540	 Goldfish emulator say N here.
541
542config X86_INTEL_CE
543	bool "CE4100 TV platform"
544	depends on PCI
545	depends on PCI_GODIRECT
546	depends on X86_IO_APIC
547	depends on X86_32
548	depends on X86_EXTENDED_PLATFORM
549	select X86_REBOOTFIXUPS
550	select OF
551	select OF_EARLY_FLATTREE
552	---help---
553	  Select for the Intel CE media processor (CE4100) SOC.
554	  This option compiles in support for the CE4100 SOC for settop
555	  boxes and media devices.
556
557config X86_INTEL_MID
558	bool "Intel MID platform support"
559	depends on X86_EXTENDED_PLATFORM
560	depends on X86_PLATFORM_DEVICES
561	depends on PCI
562	depends on X86_64 || (PCI_GOANY && X86_32)
563	depends on X86_IO_APIC
564	select SFI
565	select I2C
566	select DW_APB_TIMER
567	select APB_TIMER
568	select INTEL_SCU_IPC
569	select MFD_INTEL_MSIC
570	---help---
571	  Select to build a kernel capable of supporting Intel MID (Mobile
572	  Internet Device) platform systems which do not have the PCI legacy
573	  interfaces. If you are building for a PC class system say N here.
574
575	  Intel MID platforms are based on an Intel processor and chipset which
576	  consume less power than most of the x86 derivatives.
577
578config X86_INTEL_QUARK
579	bool "Intel Quark platform support"
580	depends on X86_32
581	depends on X86_EXTENDED_PLATFORM
582	depends on X86_PLATFORM_DEVICES
583	depends on X86_TSC
584	depends on PCI
585	depends on PCI_GOANY
586	depends on X86_IO_APIC
587	select IOSF_MBI
588	select INTEL_IMR
589	select COMMON_CLK
590	---help---
591	  Select to include support for Quark X1000 SoC.
592	  Say Y here if you have a Quark based system such as the Arduino
593	  compatible Intel Galileo.
594
595config X86_INTEL_LPSS
596	bool "Intel Low Power Subsystem Support"
597	depends on X86 && ACPI
598	select COMMON_CLK
599	select PINCTRL
600	select IOSF_MBI
601	---help---
602	  Select to build support for Intel Low Power Subsystem such as
603	  found on Intel Lynxpoint PCH. Selecting this option enables
604	  things like clock tree (common clock framework) and pincontrol
605	  which are needed by the LPSS peripheral drivers.
606
607config X86_AMD_PLATFORM_DEVICE
608	bool "AMD ACPI2Platform devices support"
609	depends on ACPI
610	select COMMON_CLK
611	select PINCTRL
612	---help---
613	  Select to interpret AMD specific ACPI device to platform device
614	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
615	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
616	  implemented under PINCTRL subsystem.
617
618config IOSF_MBI
619	tristate "Intel SoC IOSF Sideband support for SoC platforms"
620	depends on PCI
621	---help---
622	  This option enables sideband register access support for Intel SoC
623	  platforms. On these platforms the IOSF sideband is used in lieu of
624	  MSR's for some register accesses, mostly but not limited to thermal
625	  and power. Drivers may query the availability of this device to
626	  determine if they need the sideband in order to work on these
627	  platforms. The sideband is available on the following SoC products.
628	  This list is not meant to be exclusive.
629	   - BayTrail
630	   - Braswell
631	   - Quark
632
633	  You should say Y if you are running a kernel on one of these SoC's.
634
635config IOSF_MBI_DEBUG
636	bool "Enable IOSF sideband access through debugfs"
637	depends on IOSF_MBI && DEBUG_FS
638	---help---
639	  Select this option to expose the IOSF sideband access registers (MCR,
640	  MDR, MCRX) through debugfs to write and read register information from
641	  different units on the SoC. This is most useful for obtaining device
642	  state information for debug and analysis. As this is a general access
643	  mechanism, users of this option would have specific knowledge of the
644	  device they want to access.
645
646	  If you don't require the option or are in doubt, say N.
647
648config X86_RDC321X
649	bool "RDC R-321x SoC"
650	depends on X86_32
651	depends on X86_EXTENDED_PLATFORM
652	select M486
653	select X86_REBOOTFIXUPS
654	---help---
655	  This option is needed for RDC R-321x system-on-chip, also known
656	  as R-8610-(G).
657	  If you don't have one of these chips, you should say N here.
658
659config X86_32_NON_STANDARD
660	bool "Support non-standard 32-bit SMP architectures"
661	depends on X86_32 && SMP
662	depends on X86_EXTENDED_PLATFORM
663	---help---
664	  This option compiles in the bigsmp and STA2X11 default
665	  subarchitectures.  It is intended for a generic binary
666	  kernel. If you select them all, kernel will probe it one by
667	  one and will fallback to default.
668
669# Alphabetically sorted list of Non standard 32 bit platforms
670
671config X86_SUPPORTS_MEMORY_FAILURE
672	def_bool y
673	# MCE code calls memory_failure():
674	depends on X86_MCE
675	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
676	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
677	depends on X86_64 || !SPARSEMEM
678	select ARCH_SUPPORTS_MEMORY_FAILURE
679
680config STA2X11
681	bool "STA2X11 Companion Chip Support"
682	depends on X86_32_NON_STANDARD && PCI
683	select ARCH_HAS_PHYS_TO_DMA
684	select X86_DEV_DMA_OPS
685	select X86_DMA_REMAP
686	select SWIOTLB
687	select MFD_STA2X11
688	select GPIOLIB
689	default n
690	---help---
691	  This adds support for boards based on the STA2X11 IO-Hub,
692	  a.k.a. "ConneXt". The chip is used in place of the standard
693	  PC chipset, so all "standard" peripherals are missing. If this
694	  option is selected the kernel will still be able to boot on
695	  standard PC machines.
696
697config X86_32_IRIS
698	tristate "Eurobraille/Iris poweroff module"
699	depends on X86_32
700	---help---
701	  The Iris machines from EuroBraille do not have APM or ACPI support
702	  to shut themselves down properly.  A special I/O sequence is
703	  needed to do so, which is what this module does at
704	  kernel shutdown.
705
706	  This is only for Iris machines from EuroBraille.
707
708	  If unused, say N.
709
710config SCHED_OMIT_FRAME_POINTER
711	def_bool y
712	prompt "Single-depth WCHAN output"
713	depends on X86
714	---help---
715	  Calculate simpler /proc/<PID>/wchan values. If this option
716	  is disabled then wchan values will recurse back to the
717	  caller function. This provides more accurate wchan values,
718	  at the expense of slightly more scheduling overhead.
719
720	  If in doubt, say "Y".
721
722menuconfig HYPERVISOR_GUEST
723	bool "Linux guest support"
724	---help---
725	  Say Y here to enable options for running Linux under various hyper-
726	  visors. This option enables basic hypervisor detection and platform
727	  setup.
728
729	  If you say N, all options in this submenu will be skipped and
730	  disabled, and Linux guest support won't be built in.
731
732if HYPERVISOR_GUEST
733
734config PARAVIRT
735	bool "Enable paravirtualization code"
736	---help---
737	  This changes the kernel so it can modify itself when it is run
738	  under a hypervisor, potentially improving performance significantly
739	  over full virtualization.  However, when run without a hypervisor
740	  the kernel is theoretically slower and slightly larger.
741
742config PARAVIRT_DEBUG
743	bool "paravirt-ops debugging"
744	depends on PARAVIRT && DEBUG_KERNEL
745	---help---
746	  Enable to debug paravirt_ops internals.  Specifically, BUG if
747	  a paravirt_op is missing when it is called.
748
749config PARAVIRT_SPINLOCKS
750	bool "Paravirtualization layer for spinlocks"
751	depends on PARAVIRT && SMP
752	---help---
753	  Paravirtualized spinlocks allow a pvops backend to replace the
754	  spinlock implementation with something virtualization-friendly
755	  (for example, block the virtual CPU rather than spinning).
756
757	  It has a minimal impact on native kernels and gives a nice performance
758	  benefit on paravirtualized KVM / Xen kernels.
759
760	  If you are unsure how to answer this question, answer Y.
761
762config QUEUED_LOCK_STAT
763	bool "Paravirt queued spinlock statistics"
764	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
765	---help---
766	  Enable the collection of statistical data on the slowpath
767	  behavior of paravirtualized queued spinlocks and report
768	  them on debugfs.
769
770source "arch/x86/xen/Kconfig"
771
772config KVM_GUEST
773	bool "KVM Guest support (including kvmclock)"
774	depends on PARAVIRT
775	select PARAVIRT_CLOCK
776	default y
777	---help---
778	  This option enables various optimizations for running under the KVM
779	  hypervisor. It includes a paravirtualized clock, so that instead
780	  of relying on a PIT (or probably other) emulation by the
781	  underlying device model, the host provides the guest with
782	  timing infrastructure such as time of day, and system time
783
784config KVM_DEBUG_FS
785	bool "Enable debug information for KVM Guests in debugfs"
786	depends on KVM_GUEST && DEBUG_FS
787	default n
788	---help---
789	  This option enables collection of various statistics for KVM guest.
790	  Statistics are displayed in debugfs filesystem. Enabling this option
791	  may incur significant overhead.
792
793config PARAVIRT_TIME_ACCOUNTING
794	bool "Paravirtual steal time accounting"
795	depends on PARAVIRT
796	default n
797	---help---
798	  Select this option to enable fine granularity task steal time
799	  accounting. Time spent executing other tasks in parallel with
800	  the current vCPU is discounted from the vCPU power. To account for
801	  that, there can be a small performance impact.
802
803	  If in doubt, say N here.
804
805config PARAVIRT_CLOCK
806	bool
807
808config JAILHOUSE_GUEST
809	bool "Jailhouse non-root cell support"
810	depends on X86_64 && PCI
811	select X86_PM_TIMER
812	---help---
813	  This option allows to run Linux as guest in a Jailhouse non-root
814	  cell. You can leave this option disabled if you only want to start
815	  Jailhouse and run Linux afterwards in the root cell.
816
817endif #HYPERVISOR_GUEST
818
819config NO_BOOTMEM
820	def_bool y
821
822source "arch/x86/Kconfig.cpu"
823
824config HPET_TIMER
825	def_bool X86_64
826	prompt "HPET Timer Support" if X86_32
827	---help---
828	  Use the IA-PC HPET (High Precision Event Timer) to manage
829	  time in preference to the PIT and RTC, if a HPET is
830	  present.
831	  HPET is the next generation timer replacing legacy 8254s.
832	  The HPET provides a stable time base on SMP
833	  systems, unlike the TSC, but it is more expensive to access,
834	  as it is off-chip.  The interface used is documented
835	  in the HPET spec, revision 1.
836
837	  You can safely choose Y here.  However, HPET will only be
838	  activated if the platform and the BIOS support this feature.
839	  Otherwise the 8254 will be used for timing services.
840
841	  Choose N to continue using the legacy 8254 timer.
842
843config HPET_EMULATE_RTC
844	def_bool y
845	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
846
847config APB_TIMER
848       def_bool y if X86_INTEL_MID
849       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
850       select DW_APB_TIMER
851       depends on X86_INTEL_MID && SFI
852       help
853         APB timer is the replacement for 8254, HPET on X86 MID platforms.
854         The APBT provides a stable time base on SMP
855         systems, unlike the TSC, but it is more expensive to access,
856         as it is off-chip. APB timers are always running regardless of CPU
857         C states, they are used as per CPU clockevent device when possible.
858
859# Mark as expert because too many people got it wrong.
860# The code disables itself when not needed.
861config DMI
862	default y
863	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
864	bool "Enable DMI scanning" if EXPERT
865	---help---
866	  Enabled scanning of DMI to identify machine quirks. Say Y
867	  here unless you have verified that your setup is not
868	  affected by entries in the DMI blacklist. Required by PNP
869	  BIOS code.
870
871config GART_IOMMU
872	bool "Old AMD GART IOMMU support"
873	select SWIOTLB
874	depends on X86_64 && PCI && AMD_NB
875	---help---
876	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
877	  GART based hardware IOMMUs.
878
879	  The GART supports full DMA access for devices with 32-bit access
880	  limitations, on systems with more than 3 GB. This is usually needed
881	  for USB, sound, many IDE/SATA chipsets and some other devices.
882
883	  Newer systems typically have a modern AMD IOMMU, supported via
884	  the CONFIG_AMD_IOMMU=y config option.
885
886	  In normal configurations this driver is only active when needed:
887	  there's more than 3 GB of memory and the system contains a
888	  32-bit limited device.
889
890	  If unsure, say Y.
891
892config CALGARY_IOMMU
893	bool "IBM Calgary IOMMU support"
894	select SWIOTLB
895	depends on X86_64 && PCI
896	---help---
897	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
898	  systems. Needed to run systems with more than 3GB of memory
899	  properly with 32-bit PCI devices that do not support DAC
900	  (Double Address Cycle). Calgary also supports bus level
901	  isolation, where all DMAs pass through the IOMMU.  This
902	  prevents them from going anywhere except their intended
903	  destination. This catches hard-to-find kernel bugs and
904	  mis-behaving drivers and devices that do not use the DMA-API
905	  properly to set up their DMA buffers.  The IOMMU can be
906	  turned off at boot time with the iommu=off parameter.
907	  Normally the kernel will make the right choice by itself.
908	  If unsure, say Y.
909
910config CALGARY_IOMMU_ENABLED_BY_DEFAULT
911	def_bool y
912	prompt "Should Calgary be enabled by default?"
913	depends on CALGARY_IOMMU
914	---help---
915	  Should Calgary be enabled by default? if you choose 'y', Calgary
916	  will be used (if it exists). If you choose 'n', Calgary will not be
917	  used even if it exists. If you choose 'n' and would like to use
918	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
919	  If unsure, say Y.
920
921# need this always selected by IOMMU for the VIA workaround
922config SWIOTLB
923	def_bool y if X86_64
924	---help---
925	  Support for software bounce buffers used on x86-64 systems
926	  which don't have a hardware IOMMU. Using this PCI devices
927	  which can only access 32-bits of memory can be used on systems
928	  with more than 3 GB of memory.
929	  If unsure, say Y.
930
931config IOMMU_HELPER
932	def_bool y
933	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
934
935config MAXSMP
936	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
937	depends on X86_64 && SMP && DEBUG_KERNEL
938	select CPUMASK_OFFSTACK
939	---help---
940	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
941	  If unsure, say N.
942
943#
944# The maximum number of CPUs supported:
945#
946# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
947# and which can be configured interactively in the
948# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
949#
950# The ranges are different on 32-bit and 64-bit kernels, depending on
951# hardware capabilities and scalability features of the kernel.
952#
953# ( If MAXSMP is enabled we just use the highest possible value and disable
954#   interactive configuration. )
955#
956
957config NR_CPUS_RANGE_BEGIN
958	int
959	default NR_CPUS_RANGE_END if MAXSMP
960	default    1 if !SMP
961	default    2
962
963config NR_CPUS_RANGE_END
964	int
965	depends on X86_32
966	default   64 if  SMP &&  X86_BIGSMP
967	default    8 if  SMP && !X86_BIGSMP
968	default    1 if !SMP
969
970config NR_CPUS_RANGE_END
971	int
972	depends on X86_64
973	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
974	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
975	default    1 if !SMP
976
977config NR_CPUS_DEFAULT
978	int
979	depends on X86_32
980	default   32 if  X86_BIGSMP
981	default    8 if  SMP
982	default    1 if !SMP
983
984config NR_CPUS_DEFAULT
985	int
986	depends on X86_64
987	default 8192 if  MAXSMP
988	default   64 if  SMP
989	default    1 if !SMP
990
991config NR_CPUS
992	int "Maximum number of CPUs" if SMP && !MAXSMP
993	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
994	default NR_CPUS_DEFAULT
995	---help---
996	  This allows you to specify the maximum number of CPUs which this
997	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
998	  supported value is 8192, otherwise the maximum value is 512.  The
999	  minimum value which makes sense is 2.
1000
1001	  This is purely to save memory: each supported CPU adds about 8KB
1002	  to the kernel image.
1003
1004config SCHED_SMT
1005	bool "SMT (Hyperthreading) scheduler support"
1006	depends on SMP
1007	---help---
1008	  SMT scheduler support improves the CPU scheduler's decision making
1009	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1010	  cost of slightly increased overhead in some places. If unsure say
1011	  N here.
1012
1013config SCHED_MC
1014	def_bool y
1015	prompt "Multi-core scheduler support"
1016	depends on SMP
1017	---help---
1018	  Multi-core scheduler support improves the CPU scheduler's decision
1019	  making when dealing with multi-core CPU chips at a cost of slightly
1020	  increased overhead in some places. If unsure say N here.
1021
1022config SCHED_MC_PRIO
1023	bool "CPU core priorities scheduler support"
1024	depends on SCHED_MC && CPU_SUP_INTEL
1025	select X86_INTEL_PSTATE
1026	select CPU_FREQ
1027	default y
1028	---help---
1029	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1030	  core ordering determined at manufacturing time, which allows
1031	  certain cores to reach higher turbo frequencies (when running
1032	  single threaded workloads) than others.
1033
1034	  Enabling this kernel feature teaches the scheduler about
1035	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1036	  scheduler's CPU selection logic accordingly, so that higher
1037	  overall system performance can be achieved.
1038
1039	  This feature will have no effect on CPUs without this feature.
1040
1041	  If unsure say Y here.
1042
1043source "kernel/Kconfig.preempt"
1044
1045config UP_LATE_INIT
1046       def_bool y
1047       depends on !SMP && X86_LOCAL_APIC
1048
1049config X86_UP_APIC
1050	bool "Local APIC support on uniprocessors" if !PCI_MSI
1051	default PCI_MSI
1052	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1053	---help---
1054	  A local APIC (Advanced Programmable Interrupt Controller) is an
1055	  integrated interrupt controller in the CPU. If you have a single-CPU
1056	  system which has a processor with a local APIC, you can say Y here to
1057	  enable and use it. If you say Y here even though your machine doesn't
1058	  have a local APIC, then the kernel will still run with no slowdown at
1059	  all. The local APIC supports CPU-generated self-interrupts (timer,
1060	  performance counters), and the NMI watchdog which detects hard
1061	  lockups.
1062
1063config X86_UP_IOAPIC
1064	bool "IO-APIC support on uniprocessors"
1065	depends on X86_UP_APIC
1066	---help---
1067	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1068	  SMP-capable replacement for PC-style interrupt controllers. Most
1069	  SMP systems and many recent uniprocessor systems have one.
1070
1071	  If you have a single-CPU system with an IO-APIC, you can say Y here
1072	  to use it. If you say Y here even though your machine doesn't have
1073	  an IO-APIC, then the kernel will still run with no slowdown at all.
1074
1075config X86_LOCAL_APIC
1076	def_bool y
1077	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1078	select IRQ_DOMAIN_HIERARCHY
1079	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1080
1081config X86_IO_APIC
1082	def_bool y
1083	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1084
1085config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1086	bool "Reroute for broken boot IRQs"
1087	depends on X86_IO_APIC
1088	---help---
1089	  This option enables a workaround that fixes a source of
1090	  spurious interrupts. This is recommended when threaded
1091	  interrupt handling is used on systems where the generation of
1092	  superfluous "boot interrupts" cannot be disabled.
1093
1094	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1095	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1096	  kernel does during interrupt handling). On chipsets where this
1097	  boot IRQ generation cannot be disabled, this workaround keeps
1098	  the original IRQ line masked so that only the equivalent "boot
1099	  IRQ" is delivered to the CPUs. The workaround also tells the
1100	  kernel to set up the IRQ handler on the boot IRQ line. In this
1101	  way only one interrupt is delivered to the kernel. Otherwise
1102	  the spurious second interrupt may cause the kernel to bring
1103	  down (vital) interrupt lines.
1104
1105	  Only affects "broken" chipsets. Interrupt sharing may be
1106	  increased on these systems.
1107
1108config X86_MCE
1109	bool "Machine Check / overheating reporting"
1110	select GENERIC_ALLOCATOR
1111	default y
1112	---help---
1113	  Machine Check support allows the processor to notify the
1114	  kernel if it detects a problem (e.g. overheating, data corruption).
1115	  The action the kernel takes depends on the severity of the problem,
1116	  ranging from warning messages to halting the machine.
1117
1118config X86_MCELOG_LEGACY
1119	bool "Support for deprecated /dev/mcelog character device"
1120	depends on X86_MCE
1121	---help---
1122	  Enable support for /dev/mcelog which is needed by the old mcelog
1123	  userspace logging daemon. Consider switching to the new generation
1124	  rasdaemon solution.
1125
1126config X86_MCE_INTEL
1127	def_bool y
1128	prompt "Intel MCE features"
1129	depends on X86_MCE && X86_LOCAL_APIC
1130	---help---
1131	   Additional support for intel specific MCE features such as
1132	   the thermal monitor.
1133
1134config X86_MCE_AMD
1135	def_bool y
1136	prompt "AMD MCE features"
1137	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1138	---help---
1139	   Additional support for AMD specific MCE features such as
1140	   the DRAM Error Threshold.
1141
1142config X86_ANCIENT_MCE
1143	bool "Support for old Pentium 5 / WinChip machine checks"
1144	depends on X86_32 && X86_MCE
1145	---help---
1146	  Include support for machine check handling on old Pentium 5 or WinChip
1147	  systems. These typically need to be enabled explicitly on the command
1148	  line.
1149
1150config X86_MCE_THRESHOLD
1151	depends on X86_MCE_AMD || X86_MCE_INTEL
1152	def_bool y
1153
1154config X86_MCE_INJECT
1155	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1156	tristate "Machine check injector support"
1157	---help---
1158	  Provide support for injecting machine checks for testing purposes.
1159	  If you don't know what a machine check is and you don't do kernel
1160	  QA it is safe to say n.
1161
1162config X86_THERMAL_VECTOR
1163	def_bool y
1164	depends on X86_MCE_INTEL
1165
1166source "arch/x86/events/Kconfig"
1167
1168config X86_LEGACY_VM86
1169	bool "Legacy VM86 support"
1170	default n
1171	depends on X86_32
1172	---help---
1173	  This option allows user programs to put the CPU into V8086
1174	  mode, which is an 80286-era approximation of 16-bit real mode.
1175
1176	  Some very old versions of X and/or vbetool require this option
1177	  for user mode setting.  Similarly, DOSEMU will use it if
1178	  available to accelerate real mode DOS programs.  However, any
1179	  recent version of DOSEMU, X, or vbetool should be fully
1180	  functional even without kernel VM86 support, as they will all
1181	  fall back to software emulation. Nevertheless, if you are using
1182	  a 16-bit DOS program where 16-bit performance matters, vm86
1183	  mode might be faster than emulation and you might want to
1184	  enable this option.
1185
1186	  Note that any app that works on a 64-bit kernel is unlikely to
1187	  need this option, as 64-bit kernels don't, and can't, support
1188	  V8086 mode. This option is also unrelated to 16-bit protected
1189	  mode and is not needed to run most 16-bit programs under Wine.
1190
1191	  Enabling this option increases the complexity of the kernel
1192	  and slows down exception handling a tiny bit.
1193
1194	  If unsure, say N here.
1195
1196config VM86
1197       bool
1198       default X86_LEGACY_VM86
1199
1200config X86_16BIT
1201	bool "Enable support for 16-bit segments" if EXPERT
1202	default y
1203	depends on MODIFY_LDT_SYSCALL
1204	---help---
1205	  This option is required by programs like Wine to run 16-bit
1206	  protected mode legacy code on x86 processors.  Disabling
1207	  this option saves about 300 bytes on i386, or around 6K text
1208	  plus 16K runtime memory on x86-64,
1209
1210config X86_ESPFIX32
1211	def_bool y
1212	depends on X86_16BIT && X86_32
1213
1214config X86_ESPFIX64
1215	def_bool y
1216	depends on X86_16BIT && X86_64
1217
1218config X86_VSYSCALL_EMULATION
1219       bool "Enable vsyscall emulation" if EXPERT
1220       default y
1221       depends on X86_64
1222       ---help---
1223	 This enables emulation of the legacy vsyscall page.  Disabling
1224	 it is roughly equivalent to booting with vsyscall=none, except
1225	 that it will also disable the helpful warning if a program
1226	 tries to use a vsyscall.  With this option set to N, offending
1227	 programs will just segfault, citing addresses of the form
1228	 0xffffffffff600?00.
1229
1230	 This option is required by many programs built before 2013, and
1231	 care should be used even with newer programs if set to N.
1232
1233	 Disabling this option saves about 7K of kernel size and
1234	 possibly 4K of additional runtime pagetable memory.
1235
1236config TOSHIBA
1237	tristate "Toshiba Laptop support"
1238	depends on X86_32
1239	---help---
1240	  This adds a driver to safely access the System Management Mode of
1241	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1242	  not work on models with a Phoenix BIOS. The System Management Mode
1243	  is used to set the BIOS and power saving options on Toshiba portables.
1244
1245	  For information on utilities to make use of this driver see the
1246	  Toshiba Linux utilities web site at:
1247	  <http://www.buzzard.org.uk/toshiba/>.
1248
1249	  Say Y if you intend to run this kernel on a Toshiba portable.
1250	  Say N otherwise.
1251
1252config I8K
1253	tristate "Dell i8k legacy laptop support"
1254	select HWMON
1255	select SENSORS_DELL_SMM
1256	---help---
1257	  This option enables legacy /proc/i8k userspace interface in hwmon
1258	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1259	  temperature and allows controlling fan speeds of Dell laptops via
1260	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1261	  it reports also power and hotkey status. For fan speed control is
1262	  needed userspace package i8kutils.
1263
1264	  Say Y if you intend to run this kernel on old Dell laptops or want to
1265	  use userspace package i8kutils.
1266	  Say N otherwise.
1267
1268config X86_REBOOTFIXUPS
1269	bool "Enable X86 board specific fixups for reboot"
1270	depends on X86_32
1271	---help---
1272	  This enables chipset and/or board specific fixups to be done
1273	  in order to get reboot to work correctly. This is only needed on
1274	  some combinations of hardware and BIOS. The symptom, for which
1275	  this config is intended, is when reboot ends with a stalled/hung
1276	  system.
1277
1278	  Currently, the only fixup is for the Geode machines using
1279	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1280
1281	  Say Y if you want to enable the fixup. Currently, it's safe to
1282	  enable this option even if you don't need it.
1283	  Say N otherwise.
1284
1285config MICROCODE
1286	bool "CPU microcode loading support"
1287	default y
1288	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1289	select FW_LOADER
1290	---help---
1291	  If you say Y here, you will be able to update the microcode on
1292	  Intel and AMD processors. The Intel support is for the IA32 family,
1293	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1294	  AMD support is for families 0x10 and later. You will obviously need
1295	  the actual microcode binary data itself which is not shipped with
1296	  the Linux kernel.
1297
1298	  The preferred method to load microcode from a detached initrd is described
1299	  in Documentation/x86/microcode.txt. For that you need to enable
1300	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1301	  initrd for microcode blobs.
1302
1303	  In addition, you can build the microcode into the kernel. For that you
1304	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1305	  config option.
1306
1307config MICROCODE_INTEL
1308	bool "Intel microcode loading support"
1309	depends on MICROCODE
1310	default MICROCODE
1311	select FW_LOADER
1312	---help---
1313	  This options enables microcode patch loading support for Intel
1314	  processors.
1315
1316	  For the current Intel microcode data package go to
1317	  <https://downloadcenter.intel.com> and search for
1318	  'Linux Processor Microcode Data File'.
1319
1320config MICROCODE_AMD
1321	bool "AMD microcode loading support"
1322	depends on MICROCODE
1323	select FW_LOADER
1324	---help---
1325	  If you select this option, microcode patch loading support for AMD
1326	  processors will be enabled.
1327
1328config MICROCODE_OLD_INTERFACE
1329	def_bool y
1330	depends on MICROCODE
1331
1332config X86_MSR
1333	tristate "/dev/cpu/*/msr - Model-specific register support"
1334	---help---
1335	  This device gives privileged processes access to the x86
1336	  Model-Specific Registers (MSRs).  It is a character device with
1337	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1338	  MSR accesses are directed to a specific CPU on multi-processor
1339	  systems.
1340
1341config X86_CPUID
1342	tristate "/dev/cpu/*/cpuid - CPU information support"
1343	---help---
1344	  This device gives processes access to the x86 CPUID instruction to
1345	  be executed on a specific processor.  It is a character device
1346	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1347	  /dev/cpu/31/cpuid.
1348
1349choice
1350	prompt "High Memory Support"
1351	default HIGHMEM4G
1352	depends on X86_32
1353
1354config NOHIGHMEM
1355	bool "off"
1356	---help---
1357	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1358	  However, the address space of 32-bit x86 processors is only 4
1359	  Gigabytes large. That means that, if you have a large amount of
1360	  physical memory, not all of it can be "permanently mapped" by the
1361	  kernel. The physical memory that's not permanently mapped is called
1362	  "high memory".
1363
1364	  If you are compiling a kernel which will never run on a machine with
1365	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1366	  choice and suitable for most users). This will result in a "3GB/1GB"
1367	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1368	  space and the remaining part of the 4GB virtual memory space is used
1369	  by the kernel to permanently map as much physical memory as
1370	  possible.
1371
1372	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1373	  answer "4GB" here.
1374
1375	  If more than 4 Gigabytes is used then answer "64GB" here. This
1376	  selection turns Intel PAE (Physical Address Extension) mode on.
1377	  PAE implements 3-level paging on IA32 processors. PAE is fully
1378	  supported by Linux, PAE mode is implemented on all recent Intel
1379	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1380	  then the kernel will not boot on CPUs that don't support PAE!
1381
1382	  The actual amount of total physical memory will either be
1383	  auto detected or can be forced by using a kernel command line option
1384	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1385	  your boot loader (lilo or loadlin) about how to pass options to the
1386	  kernel at boot time.)
1387
1388	  If unsure, say "off".
1389
1390config HIGHMEM4G
1391	bool "4GB"
1392	---help---
1393	  Select this if you have a 32-bit processor and between 1 and 4
1394	  gigabytes of physical RAM.
1395
1396config HIGHMEM64G
1397	bool "64GB"
1398	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1399	select X86_PAE
1400	---help---
1401	  Select this if you have a 32-bit processor and more than 4
1402	  gigabytes of physical RAM.
1403
1404endchoice
1405
1406choice
1407	prompt "Memory split" if EXPERT
1408	default VMSPLIT_3G
1409	depends on X86_32
1410	---help---
1411	  Select the desired split between kernel and user memory.
1412
1413	  If the address range available to the kernel is less than the
1414	  physical memory installed, the remaining memory will be available
1415	  as "high memory". Accessing high memory is a little more costly
1416	  than low memory, as it needs to be mapped into the kernel first.
1417	  Note that increasing the kernel address space limits the range
1418	  available to user programs, making the address space there
1419	  tighter.  Selecting anything other than the default 3G/1G split
1420	  will also likely make your kernel incompatible with binary-only
1421	  kernel modules.
1422
1423	  If you are not absolutely sure what you are doing, leave this
1424	  option alone!
1425
1426	config VMSPLIT_3G
1427		bool "3G/1G user/kernel split"
1428	config VMSPLIT_3G_OPT
1429		depends on !X86_PAE
1430		bool "3G/1G user/kernel split (for full 1G low memory)"
1431	config VMSPLIT_2G
1432		bool "2G/2G user/kernel split"
1433	config VMSPLIT_2G_OPT
1434		depends on !X86_PAE
1435		bool "2G/2G user/kernel split (for full 2G low memory)"
1436	config VMSPLIT_1G
1437		bool "1G/3G user/kernel split"
1438endchoice
1439
1440config PAGE_OFFSET
1441	hex
1442	default 0xB0000000 if VMSPLIT_3G_OPT
1443	default 0x80000000 if VMSPLIT_2G
1444	default 0x78000000 if VMSPLIT_2G_OPT
1445	default 0x40000000 if VMSPLIT_1G
1446	default 0xC0000000
1447	depends on X86_32
1448
1449config HIGHMEM
1450	def_bool y
1451	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1452
1453config X86_PAE
1454	bool "PAE (Physical Address Extension) Support"
1455	depends on X86_32 && !HIGHMEM4G
1456	select SWIOTLB
1457	---help---
1458	  PAE is required for NX support, and furthermore enables
1459	  larger swapspace support for non-overcommit purposes. It
1460	  has the cost of more pagetable lookup overhead, and also
1461	  consumes more pagetable space per process.
1462
1463config X86_5LEVEL
1464	bool "Enable 5-level page tables support"
1465	select DYNAMIC_MEMORY_LAYOUT
1466	select SPARSEMEM_VMEMMAP
1467	depends on X86_64
1468	---help---
1469	  5-level paging enables access to larger address space:
1470	  upto 128 PiB of virtual address space and 4 PiB of
1471	  physical address space.
1472
1473	  It will be supported by future Intel CPUs.
1474
1475	  A kernel with the option enabled can be booted on machines that
1476	  support 4- or 5-level paging.
1477
1478	  See Documentation/x86/x86_64/5level-paging.txt for more
1479	  information.
1480
1481	  Say N if unsure.
1482
1483config ARCH_PHYS_ADDR_T_64BIT
1484	def_bool y
1485	depends on X86_64 || X86_PAE
1486
1487config ARCH_DMA_ADDR_T_64BIT
1488	def_bool y
1489	depends on X86_64 || HIGHMEM64G
1490
1491config X86_DIRECT_GBPAGES
1492	def_bool y
1493	depends on X86_64 && !DEBUG_PAGEALLOC
1494	---help---
1495	  Certain kernel features effectively disable kernel
1496	  linear 1 GB mappings (even if the CPU otherwise
1497	  supports them), so don't confuse the user by printing
1498	  that we have them enabled.
1499
1500config ARCH_HAS_MEM_ENCRYPT
1501	def_bool y
1502
1503config AMD_MEM_ENCRYPT
1504	bool "AMD Secure Memory Encryption (SME) support"
1505	depends on X86_64 && CPU_SUP_AMD
1506	---help---
1507	  Say yes to enable support for the encryption of system memory.
1508	  This requires an AMD processor that supports Secure Memory
1509	  Encryption (SME).
1510
1511config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1512	bool "Activate AMD Secure Memory Encryption (SME) by default"
1513	default y
1514	depends on AMD_MEM_ENCRYPT
1515	---help---
1516	  Say yes to have system memory encrypted by default if running on
1517	  an AMD processor that supports Secure Memory Encryption (SME).
1518
1519	  If set to Y, then the encryption of system memory can be
1520	  deactivated with the mem_encrypt=off command line option.
1521
1522	  If set to N, then the encryption of system memory can be
1523	  activated with the mem_encrypt=on command line option.
1524
1525config ARCH_USE_MEMREMAP_PROT
1526	def_bool y
1527	depends on AMD_MEM_ENCRYPT
1528
1529# Common NUMA Features
1530config NUMA
1531	bool "Numa Memory Allocation and Scheduler Support"
1532	depends on SMP
1533	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1534	default y if X86_BIGSMP
1535	---help---
1536	  Enable NUMA (Non Uniform Memory Access) support.
1537
1538	  The kernel will try to allocate memory used by a CPU on the
1539	  local memory controller of the CPU and add some more
1540	  NUMA awareness to the kernel.
1541
1542	  For 64-bit this is recommended if the system is Intel Core i7
1543	  (or later), AMD Opteron, or EM64T NUMA.
1544
1545	  For 32-bit this is only needed if you boot a 32-bit
1546	  kernel on a 64-bit NUMA platform.
1547
1548	  Otherwise, you should say N.
1549
1550config AMD_NUMA
1551	def_bool y
1552	prompt "Old style AMD Opteron NUMA detection"
1553	depends on X86_64 && NUMA && PCI
1554	---help---
1555	  Enable AMD NUMA node topology detection.  You should say Y here if
1556	  you have a multi processor AMD system. This uses an old method to
1557	  read the NUMA configuration directly from the builtin Northbridge
1558	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1559	  which also takes priority if both are compiled in.
1560
1561config X86_64_ACPI_NUMA
1562	def_bool y
1563	prompt "ACPI NUMA detection"
1564	depends on X86_64 && NUMA && ACPI && PCI
1565	select ACPI_NUMA
1566	---help---
1567	  Enable ACPI SRAT based node topology detection.
1568
1569# Some NUMA nodes have memory ranges that span
1570# other nodes.  Even though a pfn is valid and
1571# between a node's start and end pfns, it may not
1572# reside on that node.  See memmap_init_zone()
1573# for details.
1574config NODES_SPAN_OTHER_NODES
1575	def_bool y
1576	depends on X86_64_ACPI_NUMA
1577
1578config NUMA_EMU
1579	bool "NUMA emulation"
1580	depends on NUMA
1581	---help---
1582	  Enable NUMA emulation. A flat machine will be split
1583	  into virtual nodes when booted with "numa=fake=N", where N is the
1584	  number of nodes. This is only useful for debugging.
1585
1586config NODES_SHIFT
1587	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1588	range 1 10
1589	default "10" if MAXSMP
1590	default "6" if X86_64
1591	default "3"
1592	depends on NEED_MULTIPLE_NODES
1593	---help---
1594	  Specify the maximum number of NUMA Nodes available on the target
1595	  system.  Increases memory reserved to accommodate various tables.
1596
1597config ARCH_HAVE_MEMORY_PRESENT
1598	def_bool y
1599	depends on X86_32 && DISCONTIGMEM
1600
1601config ARCH_FLATMEM_ENABLE
1602	def_bool y
1603	depends on X86_32 && !NUMA
1604
1605config ARCH_DISCONTIGMEM_ENABLE
1606	def_bool y
1607	depends on NUMA && X86_32
1608
1609config ARCH_DISCONTIGMEM_DEFAULT
1610	def_bool y
1611	depends on NUMA && X86_32
1612
1613config ARCH_SPARSEMEM_ENABLE
1614	def_bool y
1615	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1616	select SPARSEMEM_STATIC if X86_32
1617	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1618
1619config ARCH_SPARSEMEM_DEFAULT
1620	def_bool y
1621	depends on X86_64
1622
1623config ARCH_SELECT_MEMORY_MODEL
1624	def_bool y
1625	depends on ARCH_SPARSEMEM_ENABLE
1626
1627config ARCH_MEMORY_PROBE
1628	bool "Enable sysfs memory/probe interface"
1629	depends on X86_64 && MEMORY_HOTPLUG
1630	help
1631	  This option enables a sysfs memory/probe interface for testing.
1632	  See Documentation/memory-hotplug.txt for more information.
1633	  If you are unsure how to answer this question, answer N.
1634
1635config ARCH_PROC_KCORE_TEXT
1636	def_bool y
1637	depends on X86_64 && PROC_KCORE
1638
1639config ILLEGAL_POINTER_VALUE
1640       hex
1641       default 0 if X86_32
1642       default 0xdead000000000000 if X86_64
1643
1644source "mm/Kconfig"
1645
1646config X86_PMEM_LEGACY_DEVICE
1647	bool
1648
1649config X86_PMEM_LEGACY
1650	tristate "Support non-standard NVDIMMs and ADR protected memory"
1651	depends on PHYS_ADDR_T_64BIT
1652	depends on BLK_DEV
1653	select X86_PMEM_LEGACY_DEVICE
1654	select LIBNVDIMM
1655	help
1656	  Treat memory marked using the non-standard e820 type of 12 as used
1657	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1658	  The kernel will offer these regions to the 'pmem' driver so
1659	  they can be used for persistent storage.
1660
1661	  Say Y if unsure.
1662
1663config HIGHPTE
1664	bool "Allocate 3rd-level pagetables from highmem"
1665	depends on HIGHMEM
1666	---help---
1667	  The VM uses one page table entry for each page of physical memory.
1668	  For systems with a lot of RAM, this can be wasteful of precious
1669	  low memory.  Setting this option will put user-space page table
1670	  entries in high memory.
1671
1672config X86_CHECK_BIOS_CORRUPTION
1673	bool "Check for low memory corruption"
1674	---help---
1675	  Periodically check for memory corruption in low memory, which
1676	  is suspected to be caused by BIOS.  Even when enabled in the
1677	  configuration, it is disabled at runtime.  Enable it by
1678	  setting "memory_corruption_check=1" on the kernel command
1679	  line.  By default it scans the low 64k of memory every 60
1680	  seconds; see the memory_corruption_check_size and
1681	  memory_corruption_check_period parameters in
1682	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1683
1684	  When enabled with the default parameters, this option has
1685	  almost no overhead, as it reserves a relatively small amount
1686	  of memory and scans it infrequently.  It both detects corruption
1687	  and prevents it from affecting the running system.
1688
1689	  It is, however, intended as a diagnostic tool; if repeatable
1690	  BIOS-originated corruption always affects the same memory,
1691	  you can use memmap= to prevent the kernel from using that
1692	  memory.
1693
1694config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1695	bool "Set the default setting of memory_corruption_check"
1696	depends on X86_CHECK_BIOS_CORRUPTION
1697	default y
1698	---help---
1699	  Set whether the default state of memory_corruption_check is
1700	  on or off.
1701
1702config X86_RESERVE_LOW
1703	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1704	default 64
1705	range 4 640
1706	---help---
1707	  Specify the amount of low memory to reserve for the BIOS.
1708
1709	  The first page contains BIOS data structures that the kernel
1710	  must not use, so that page must always be reserved.
1711
1712	  By default we reserve the first 64K of physical RAM, as a
1713	  number of BIOSes are known to corrupt that memory range
1714	  during events such as suspend/resume or monitor cable
1715	  insertion, so it must not be used by the kernel.
1716
1717	  You can set this to 4 if you are absolutely sure that you
1718	  trust the BIOS to get all its memory reservations and usages
1719	  right.  If you know your BIOS have problems beyond the
1720	  default 64K area, you can set this to 640 to avoid using the
1721	  entire low memory range.
1722
1723	  If you have doubts about the BIOS (e.g. suspend/resume does
1724	  not work or there's kernel crashes after certain hardware
1725	  hotplug events) then you might want to enable
1726	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1727	  typical corruption patterns.
1728
1729	  Leave this to the default value of 64 if you are unsure.
1730
1731config MATH_EMULATION
1732	bool
1733	depends on MODIFY_LDT_SYSCALL
1734	prompt "Math emulation" if X86_32
1735	---help---
1736	  Linux can emulate a math coprocessor (used for floating point
1737	  operations) if you don't have one. 486DX and Pentium processors have
1738	  a math coprocessor built in, 486SX and 386 do not, unless you added
1739	  a 487DX or 387, respectively. (The messages during boot time can
1740	  give you some hints here ["man dmesg"].) Everyone needs either a
1741	  coprocessor or this emulation.
1742
1743	  If you don't have a math coprocessor, you need to say Y here; if you
1744	  say Y here even though you have a coprocessor, the coprocessor will
1745	  be used nevertheless. (This behavior can be changed with the kernel
1746	  command line option "no387", which comes handy if your coprocessor
1747	  is broken. Try "man bootparam" or see the documentation of your boot
1748	  loader (lilo or loadlin) about how to pass options to the kernel at
1749	  boot time.) This means that it is a good idea to say Y here if you
1750	  intend to use this kernel on different machines.
1751
1752	  More information about the internals of the Linux math coprocessor
1753	  emulation can be found in <file:arch/x86/math-emu/README>.
1754
1755	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1756	  kernel, it won't hurt.
1757
1758config MTRR
1759	def_bool y
1760	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1761	---help---
1762	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1763	  the Memory Type Range Registers (MTRRs) may be used to control
1764	  processor access to memory ranges. This is most useful if you have
1765	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1766	  allows bus write transfers to be combined into a larger transfer
1767	  before bursting over the PCI/AGP bus. This can increase performance
1768	  of image write operations 2.5 times or more. Saying Y here creates a
1769	  /proc/mtrr file which may be used to manipulate your processor's
1770	  MTRRs. Typically the X server should use this.
1771
1772	  This code has a reasonably generic interface so that similar
1773	  control registers on other processors can be easily supported
1774	  as well:
1775
1776	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1777	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1778	  these, the ARRs are used to emulate the MTRRs.
1779	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1780	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1781	  write-combining. All of these processors are supported by this code
1782	  and it makes sense to say Y here if you have one of them.
1783
1784	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1785	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1786	  can lead to all sorts of problems, so it's good to say Y here.
1787
1788	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1789	  just add about 9 KB to your kernel.
1790
1791	  See <file:Documentation/x86/mtrr.txt> for more information.
1792
1793config MTRR_SANITIZER
1794	def_bool y
1795	prompt "MTRR cleanup support"
1796	depends on MTRR
1797	---help---
1798	  Convert MTRR layout from continuous to discrete, so X drivers can
1799	  add writeback entries.
1800
1801	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1802	  The largest mtrr entry size for a continuous block can be set with
1803	  mtrr_chunk_size.
1804
1805	  If unsure, say Y.
1806
1807config MTRR_SANITIZER_ENABLE_DEFAULT
1808	int "MTRR cleanup enable value (0-1)"
1809	range 0 1
1810	default "0"
1811	depends on MTRR_SANITIZER
1812	---help---
1813	  Enable mtrr cleanup default value
1814
1815config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1816	int "MTRR cleanup spare reg num (0-7)"
1817	range 0 7
1818	default "1"
1819	depends on MTRR_SANITIZER
1820	---help---
1821	  mtrr cleanup spare entries default, it can be changed via
1822	  mtrr_spare_reg_nr=N on the kernel command line.
1823
1824config X86_PAT
1825	def_bool y
1826	prompt "x86 PAT support" if EXPERT
1827	depends on MTRR
1828	---help---
1829	  Use PAT attributes to setup page level cache control.
1830
1831	  PATs are the modern equivalents of MTRRs and are much more
1832	  flexible than MTRRs.
1833
1834	  Say N here if you see bootup problems (boot crash, boot hang,
1835	  spontaneous reboots) or a non-working video driver.
1836
1837	  If unsure, say Y.
1838
1839config ARCH_USES_PG_UNCACHED
1840	def_bool y
1841	depends on X86_PAT
1842
1843config ARCH_RANDOM
1844	def_bool y
1845	prompt "x86 architectural random number generator" if EXPERT
1846	---help---
1847	  Enable the x86 architectural RDRAND instruction
1848	  (Intel Bull Mountain technology) to generate random numbers.
1849	  If supported, this is a high bandwidth, cryptographically
1850	  secure hardware random number generator.
1851
1852config X86_SMAP
1853	def_bool y
1854	prompt "Supervisor Mode Access Prevention" if EXPERT
1855	---help---
1856	  Supervisor Mode Access Prevention (SMAP) is a security
1857	  feature in newer Intel processors.  There is a small
1858	  performance cost if this enabled and turned on; there is
1859	  also a small increase in the kernel size if this is enabled.
1860
1861	  If unsure, say Y.
1862
1863config X86_INTEL_UMIP
1864	def_bool y
1865	depends on CPU_SUP_INTEL
1866	prompt "Intel User Mode Instruction Prevention" if EXPERT
1867	---help---
1868	  The User Mode Instruction Prevention (UMIP) is a security
1869	  feature in newer Intel processors. If enabled, a general
1870	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1871	  or STR instructions are executed in user mode. These instructions
1872	  unnecessarily expose information about the hardware state.
1873
1874	  The vast majority of applications do not use these instructions.
1875	  For the very few that do, software emulation is provided in
1876	  specific cases in protected and virtual-8086 modes. Emulated
1877	  results are dummy.
1878
1879config X86_INTEL_MPX
1880	prompt "Intel MPX (Memory Protection Extensions)"
1881	def_bool n
1882	# Note: only available in 64-bit mode due to VMA flags shortage
1883	depends on CPU_SUP_INTEL && X86_64
1884	select ARCH_USES_HIGH_VMA_FLAGS
1885	---help---
1886	  MPX provides hardware features that can be used in
1887	  conjunction with compiler-instrumented code to check
1888	  memory references.  It is designed to detect buffer
1889	  overflow or underflow bugs.
1890
1891	  This option enables running applications which are
1892	  instrumented or otherwise use MPX.  It does not use MPX
1893	  itself inside the kernel or to protect the kernel
1894	  against bad memory references.
1895
1896	  Enabling this option will make the kernel larger:
1897	  ~8k of kernel text and 36 bytes of data on a 64-bit
1898	  defconfig.  It adds a long to the 'mm_struct' which
1899	  will increase the kernel memory overhead of each
1900	  process and adds some branches to paths used during
1901	  exec() and munmap().
1902
1903	  For details, see Documentation/x86/intel_mpx.txt
1904
1905	  If unsure, say N.
1906
1907config X86_INTEL_MEMORY_PROTECTION_KEYS
1908	prompt "Intel Memory Protection Keys"
1909	def_bool y
1910	# Note: only available in 64-bit mode
1911	depends on CPU_SUP_INTEL && X86_64
1912	select ARCH_USES_HIGH_VMA_FLAGS
1913	select ARCH_HAS_PKEYS
1914	---help---
1915	  Memory Protection Keys provides a mechanism for enforcing
1916	  page-based protections, but without requiring modification of the
1917	  page tables when an application changes protection domains.
1918
1919	  For details, see Documentation/x86/protection-keys.txt
1920
1921	  If unsure, say y.
1922
1923config EFI
1924	bool "EFI runtime service support"
1925	depends on ACPI
1926	select UCS2_STRING
1927	select EFI_RUNTIME_WRAPPERS
1928	---help---
1929	  This enables the kernel to use EFI runtime services that are
1930	  available (such as the EFI variable services).
1931
1932	  This option is only useful on systems that have EFI firmware.
1933	  In addition, you should use the latest ELILO loader available
1934	  at <http://elilo.sourceforge.net> in order to take advantage
1935	  of EFI runtime services. However, even with this option, the
1936	  resultant kernel should continue to boot on existing non-EFI
1937	  platforms.
1938
1939config EFI_STUB
1940       bool "EFI stub support"
1941       depends on EFI && !X86_USE_3DNOW
1942       select RELOCATABLE
1943       ---help---
1944          This kernel feature allows a bzImage to be loaded directly
1945	  by EFI firmware without the use of a bootloader.
1946
1947	  See Documentation/efi-stub.txt for more information.
1948
1949config EFI_MIXED
1950	bool "EFI mixed-mode support"
1951	depends on EFI_STUB && X86_64
1952	---help---
1953	   Enabling this feature allows a 64-bit kernel to be booted
1954	   on a 32-bit firmware, provided that your CPU supports 64-bit
1955	   mode.
1956
1957	   Note that it is not possible to boot a mixed-mode enabled
1958	   kernel via the EFI boot stub - a bootloader that supports
1959	   the EFI handover protocol must be used.
1960
1961	   If unsure, say N.
1962
1963config SECCOMP
1964	def_bool y
1965	prompt "Enable seccomp to safely compute untrusted bytecode"
1966	---help---
1967	  This kernel feature is useful for number crunching applications
1968	  that may need to compute untrusted bytecode during their
1969	  execution. By using pipes or other transports made available to
1970	  the process as file descriptors supporting the read/write
1971	  syscalls, it's possible to isolate those applications in
1972	  their own address space using seccomp. Once seccomp is
1973	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1974	  and the task is only allowed to execute a few safe syscalls
1975	  defined by each seccomp mode.
1976
1977	  If unsure, say Y. Only embedded should say N here.
1978
1979source kernel/Kconfig.hz
1980
1981config KEXEC
1982	bool "kexec system call"
1983	select KEXEC_CORE
1984	---help---
1985	  kexec is a system call that implements the ability to shutdown your
1986	  current kernel, and to start another kernel.  It is like a reboot
1987	  but it is independent of the system firmware.   And like a reboot
1988	  you can start any kernel with it, not just Linux.
1989
1990	  The name comes from the similarity to the exec system call.
1991
1992	  It is an ongoing process to be certain the hardware in a machine
1993	  is properly shutdown, so do not be surprised if this code does not
1994	  initially work for you.  As of this writing the exact hardware
1995	  interface is strongly in flux, so no good recommendation can be
1996	  made.
1997
1998config KEXEC_FILE
1999	bool "kexec file based system call"
2000	select KEXEC_CORE
2001	select BUILD_BIN2C
2002	depends on X86_64
2003	depends on CRYPTO=y
2004	depends on CRYPTO_SHA256=y
2005	---help---
2006	  This is new version of kexec system call. This system call is
2007	  file based and takes file descriptors as system call argument
2008	  for kernel and initramfs as opposed to list of segments as
2009	  accepted by previous system call.
2010
2011config KEXEC_VERIFY_SIG
2012	bool "Verify kernel signature during kexec_file_load() syscall"
2013	depends on KEXEC_FILE
2014	---help---
2015	  This option makes kernel signature verification mandatory for
2016	  the kexec_file_load() syscall.
2017
2018	  In addition to that option, you need to enable signature
2019	  verification for the corresponding kernel image type being
2020	  loaded in order for this to work.
2021
2022config KEXEC_BZIMAGE_VERIFY_SIG
2023	bool "Enable bzImage signature verification support"
2024	depends on KEXEC_VERIFY_SIG
2025	depends on SIGNED_PE_FILE_VERIFICATION
2026	select SYSTEM_TRUSTED_KEYRING
2027	---help---
2028	  Enable bzImage signature verification support.
2029
2030config CRASH_DUMP
2031	bool "kernel crash dumps"
2032	depends on X86_64 || (X86_32 && HIGHMEM)
2033	---help---
2034	  Generate crash dump after being started by kexec.
2035	  This should be normally only set in special crash dump kernels
2036	  which are loaded in the main kernel with kexec-tools into
2037	  a specially reserved region and then later executed after
2038	  a crash by kdump/kexec. The crash dump kernel must be compiled
2039	  to a memory address not used by the main kernel or BIOS using
2040	  PHYSICAL_START, or it must be built as a relocatable image
2041	  (CONFIG_RELOCATABLE=y).
2042	  For more details see Documentation/kdump/kdump.txt
2043
2044config KEXEC_JUMP
2045	bool "kexec jump"
2046	depends on KEXEC && HIBERNATION
2047	---help---
2048	  Jump between original kernel and kexeced kernel and invoke
2049	  code in physical address mode via KEXEC
2050
2051config PHYSICAL_START
2052	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2053	default "0x1000000"
2054	---help---
2055	  This gives the physical address where the kernel is loaded.
2056
2057	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2058	  bzImage will decompress itself to above physical address and
2059	  run from there. Otherwise, bzImage will run from the address where
2060	  it has been loaded by the boot loader and will ignore above physical
2061	  address.
2062
2063	  In normal kdump cases one does not have to set/change this option
2064	  as now bzImage can be compiled as a completely relocatable image
2065	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2066	  address. This option is mainly useful for the folks who don't want
2067	  to use a bzImage for capturing the crash dump and want to use a
2068	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2069	  to be specifically compiled to run from a specific memory area
2070	  (normally a reserved region) and this option comes handy.
2071
2072	  So if you are using bzImage for capturing the crash dump,
2073	  leave the value here unchanged to 0x1000000 and set
2074	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2075	  for capturing the crash dump change this value to start of
2076	  the reserved region.  In other words, it can be set based on
2077	  the "X" value as specified in the "crashkernel=YM@XM"
2078	  command line boot parameter passed to the panic-ed
2079	  kernel. Please take a look at Documentation/kdump/kdump.txt
2080	  for more details about crash dumps.
2081
2082	  Usage of bzImage for capturing the crash dump is recommended as
2083	  one does not have to build two kernels. Same kernel can be used
2084	  as production kernel and capture kernel. Above option should have
2085	  gone away after relocatable bzImage support is introduced. But it
2086	  is present because there are users out there who continue to use
2087	  vmlinux for dump capture. This option should go away down the
2088	  line.
2089
2090	  Don't change this unless you know what you are doing.
2091
2092config RELOCATABLE
2093	bool "Build a relocatable kernel"
2094	default y
2095	---help---
2096	  This builds a kernel image that retains relocation information
2097	  so it can be loaded someplace besides the default 1MB.
2098	  The relocations tend to make the kernel binary about 10% larger,
2099	  but are discarded at runtime.
2100
2101	  One use is for the kexec on panic case where the recovery kernel
2102	  must live at a different physical address than the primary
2103	  kernel.
2104
2105	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2106	  it has been loaded at and the compile time physical address
2107	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2108
2109config RANDOMIZE_BASE
2110	bool "Randomize the address of the kernel image (KASLR)"
2111	depends on RELOCATABLE
2112	default y
2113	---help---
2114	  In support of Kernel Address Space Layout Randomization (KASLR),
2115	  this randomizes the physical address at which the kernel image
2116	  is decompressed and the virtual address where the kernel
2117	  image is mapped, as a security feature that deters exploit
2118	  attempts relying on knowledge of the location of kernel
2119	  code internals.
2120
2121	  On 64-bit, the kernel physical and virtual addresses are
2122	  randomized separately. The physical address will be anywhere
2123	  between 16MB and the top of physical memory (up to 64TB). The
2124	  virtual address will be randomized from 16MB up to 1GB (9 bits
2125	  of entropy). Note that this also reduces the memory space
2126	  available to kernel modules from 1.5GB to 1GB.
2127
2128	  On 32-bit, the kernel physical and virtual addresses are
2129	  randomized together. They will be randomized from 16MB up to
2130	  512MB (8 bits of entropy).
2131
2132	  Entropy is generated using the RDRAND instruction if it is
2133	  supported. If RDTSC is supported, its value is mixed into
2134	  the entropy pool as well. If neither RDRAND nor RDTSC are
2135	  supported, then entropy is read from the i8254 timer. The
2136	  usable entropy is limited by the kernel being built using
2137	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2138	  minimum of 2MB. As a result, only 10 bits of entropy are
2139	  theoretically possible, but the implementations are further
2140	  limited due to memory layouts.
2141
2142	  If unsure, say Y.
2143
2144# Relocation on x86 needs some additional build support
2145config X86_NEED_RELOCS
2146	def_bool y
2147	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2148
2149config PHYSICAL_ALIGN
2150	hex "Alignment value to which kernel should be aligned"
2151	default "0x200000"
2152	range 0x2000 0x1000000 if X86_32
2153	range 0x200000 0x1000000 if X86_64
2154	---help---
2155	  This value puts the alignment restrictions on physical address
2156	  where kernel is loaded and run from. Kernel is compiled for an
2157	  address which meets above alignment restriction.
2158
2159	  If bootloader loads the kernel at a non-aligned address and
2160	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2161	  address aligned to above value and run from there.
2162
2163	  If bootloader loads the kernel at a non-aligned address and
2164	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2165	  load address and decompress itself to the address it has been
2166	  compiled for and run from there. The address for which kernel is
2167	  compiled already meets above alignment restrictions. Hence the
2168	  end result is that kernel runs from a physical address meeting
2169	  above alignment restrictions.
2170
2171	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2172	  this value must be a multiple of 0x200000.
2173
2174	  Don't change this unless you know what you are doing.
2175
2176config DYNAMIC_MEMORY_LAYOUT
2177	bool
2178	---help---
2179	  This option makes base addresses of vmalloc and vmemmap as well as
2180	  __PAGE_OFFSET movable during boot.
2181
2182config RANDOMIZE_MEMORY
2183	bool "Randomize the kernel memory sections"
2184	depends on X86_64
2185	depends on RANDOMIZE_BASE
2186	select DYNAMIC_MEMORY_LAYOUT
2187	default RANDOMIZE_BASE
2188	---help---
2189	   Randomizes the base virtual address of kernel memory sections
2190	   (physical memory mapping, vmalloc & vmemmap). This security feature
2191	   makes exploits relying on predictable memory locations less reliable.
2192
2193	   The order of allocations remains unchanged. Entropy is generated in
2194	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2195	   configuration have in average 30,000 different possible virtual
2196	   addresses for each memory section.
2197
2198	   If unsure, say Y.
2199
2200config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2201	hex "Physical memory mapping padding" if EXPERT
2202	depends on RANDOMIZE_MEMORY
2203	default "0xa" if MEMORY_HOTPLUG
2204	default "0x0"
2205	range 0x1 0x40 if MEMORY_HOTPLUG
2206	range 0x0 0x40
2207	---help---
2208	   Define the padding in terabytes added to the existing physical
2209	   memory size during kernel memory randomization. It is useful
2210	   for memory hotplug support but reduces the entropy available for
2211	   address randomization.
2212
2213	   If unsure, leave at the default value.
2214
2215config HOTPLUG_CPU
2216	bool "Support for hot-pluggable CPUs"
2217	depends on SMP
2218	---help---
2219	  Say Y here to allow turning CPUs off and on. CPUs can be
2220	  controlled through /sys/devices/system/cpu.
2221	  ( Note: power management support will enable this option
2222	    automatically on SMP systems. )
2223	  Say N if you want to disable CPU hotplug.
2224
2225config BOOTPARAM_HOTPLUG_CPU0
2226	bool "Set default setting of cpu0_hotpluggable"
2227	default n
2228	depends on HOTPLUG_CPU
2229	---help---
2230	  Set whether default state of cpu0_hotpluggable is on or off.
2231
2232	  Say Y here to enable CPU0 hotplug by default. If this switch
2233	  is turned on, there is no need to give cpu0_hotplug kernel
2234	  parameter and the CPU0 hotplug feature is enabled by default.
2235
2236	  Please note: there are two known CPU0 dependencies if you want
2237	  to enable the CPU0 hotplug feature either by this switch or by
2238	  cpu0_hotplug kernel parameter.
2239
2240	  First, resume from hibernate or suspend always starts from CPU0.
2241	  So hibernate and suspend are prevented if CPU0 is offline.
2242
2243	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2244	  offline if any interrupt can not migrate out of CPU0. There may
2245	  be other CPU0 dependencies.
2246
2247	  Please make sure the dependencies are under your control before
2248	  you enable this feature.
2249
2250	  Say N if you don't want to enable CPU0 hotplug feature by default.
2251	  You still can enable the CPU0 hotplug feature at boot by kernel
2252	  parameter cpu0_hotplug.
2253
2254config DEBUG_HOTPLUG_CPU0
2255	def_bool n
2256	prompt "Debug CPU0 hotplug"
2257	depends on HOTPLUG_CPU
2258	---help---
2259	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2260	  soon as possible and boots up userspace with CPU0 offlined. User
2261	  can online CPU0 back after boot time.
2262
2263	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2264	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2265	  compilation or giving cpu0_hotplug kernel parameter at boot.
2266
2267	  If unsure, say N.
2268
2269config COMPAT_VDSO
2270	def_bool n
2271	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2272	depends on COMPAT_32
2273	---help---
2274	  Certain buggy versions of glibc will crash if they are
2275	  presented with a 32-bit vDSO that is not mapped at the address
2276	  indicated in its segment table.
2277
2278	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2279	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2280	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2281	  the only released version with the bug, but OpenSUSE 9
2282	  contains a buggy "glibc 2.3.2".
2283
2284	  The symptom of the bug is that everything crashes on startup, saying:
2285	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2286
2287	  Saying Y here changes the default value of the vdso32 boot
2288	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2289	  This works around the glibc bug but hurts performance.
2290
2291	  If unsure, say N: if you are compiling your own kernel, you
2292	  are unlikely to be using a buggy version of glibc.
2293
2294choice
2295	prompt "vsyscall table for legacy applications"
2296	depends on X86_64
2297	default LEGACY_VSYSCALL_EMULATE
2298	help
2299	  Legacy user code that does not know how to find the vDSO expects
2300	  to be able to issue three syscalls by calling fixed addresses in
2301	  kernel space. Since this location is not randomized with ASLR,
2302	  it can be used to assist security vulnerability exploitation.
2303
2304	  This setting can be changed at boot time via the kernel command
2305	  line parameter vsyscall=[emulate|none].
2306
2307	  On a system with recent enough glibc (2.14 or newer) and no
2308	  static binaries, you can say None without a performance penalty
2309	  to improve security.
2310
2311	  If unsure, select "Emulate".
2312
2313	config LEGACY_VSYSCALL_EMULATE
2314		bool "Emulate"
2315		help
2316		  The kernel traps and emulates calls into the fixed
2317		  vsyscall address mapping. This makes the mapping
2318		  non-executable, but it still contains known contents,
2319		  which could be used in certain rare security vulnerability
2320		  exploits. This configuration is recommended when userspace
2321		  still uses the vsyscall area.
2322
2323	config LEGACY_VSYSCALL_NONE
2324		bool "None"
2325		help
2326		  There will be no vsyscall mapping at all. This will
2327		  eliminate any risk of ASLR bypass due to the vsyscall
2328		  fixed address mapping. Attempts to use the vsyscalls
2329		  will be reported to dmesg, so that either old or
2330		  malicious userspace programs can be identified.
2331
2332endchoice
2333
2334config CMDLINE_BOOL
2335	bool "Built-in kernel command line"
2336	---help---
2337	  Allow for specifying boot arguments to the kernel at
2338	  build time.  On some systems (e.g. embedded ones), it is
2339	  necessary or convenient to provide some or all of the
2340	  kernel boot arguments with the kernel itself (that is,
2341	  to not rely on the boot loader to provide them.)
2342
2343	  To compile command line arguments into the kernel,
2344	  set this option to 'Y', then fill in the
2345	  boot arguments in CONFIG_CMDLINE.
2346
2347	  Systems with fully functional boot loaders (i.e. non-embedded)
2348	  should leave this option set to 'N'.
2349
2350config CMDLINE
2351	string "Built-in kernel command string"
2352	depends on CMDLINE_BOOL
2353	default ""
2354	---help---
2355	  Enter arguments here that should be compiled into the kernel
2356	  image and used at boot time.  If the boot loader provides a
2357	  command line at boot time, it is appended to this string to
2358	  form the full kernel command line, when the system boots.
2359
2360	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2361	  change this behavior.
2362
2363	  In most cases, the command line (whether built-in or provided
2364	  by the boot loader) should specify the device for the root
2365	  file system.
2366
2367config CMDLINE_OVERRIDE
2368	bool "Built-in command line overrides boot loader arguments"
2369	depends on CMDLINE_BOOL
2370	---help---
2371	  Set this option to 'Y' to have the kernel ignore the boot loader
2372	  command line, and use ONLY the built-in command line.
2373
2374	  This is used to work around broken boot loaders.  This should
2375	  be set to 'N' under normal conditions.
2376
2377config MODIFY_LDT_SYSCALL
2378	bool "Enable the LDT (local descriptor table)" if EXPERT
2379	default y
2380	---help---
2381	  Linux can allow user programs to install a per-process x86
2382	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2383	  call.  This is required to run 16-bit or segmented code such as
2384	  DOSEMU or some Wine programs.  It is also used by some very old
2385	  threading libraries.
2386
2387	  Enabling this feature adds a small amount of overhead to
2388	  context switches and increases the low-level kernel attack
2389	  surface.  Disabling it removes the modify_ldt(2) system call.
2390
2391	  Saying 'N' here may make sense for embedded or server kernels.
2392
2393source "kernel/livepatch/Kconfig"
2394
2395endmenu
2396
2397config ARCH_HAS_ADD_PAGES
2398	def_bool y
2399	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2400
2401config ARCH_ENABLE_MEMORY_HOTPLUG
2402	def_bool y
2403	depends on X86_64 || (X86_32 && HIGHMEM)
2404
2405config ARCH_ENABLE_MEMORY_HOTREMOVE
2406	def_bool y
2407	depends on MEMORY_HOTPLUG
2408
2409config USE_PERCPU_NUMA_NODE_ID
2410	def_bool y
2411	depends on NUMA
2412
2413config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2414	def_bool y
2415	depends on X86_64 || X86_PAE
2416
2417config ARCH_ENABLE_HUGEPAGE_MIGRATION
2418	def_bool y
2419	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2420
2421config ARCH_ENABLE_THP_MIGRATION
2422	def_bool y
2423	depends on X86_64 && TRANSPARENT_HUGEPAGE
2424
2425menu "Power management and ACPI options"
2426
2427config ARCH_HIBERNATION_HEADER
2428	def_bool y
2429	depends on X86_64 && HIBERNATION
2430
2431source "kernel/power/Kconfig"
2432
2433source "drivers/acpi/Kconfig"
2434
2435source "drivers/sfi/Kconfig"
2436
2437config X86_APM_BOOT
2438	def_bool y
2439	depends on APM
2440
2441menuconfig APM
2442	tristate "APM (Advanced Power Management) BIOS support"
2443	depends on X86_32 && PM_SLEEP
2444	---help---
2445	  APM is a BIOS specification for saving power using several different
2446	  techniques. This is mostly useful for battery powered laptops with
2447	  APM compliant BIOSes. If you say Y here, the system time will be
2448	  reset after a RESUME operation, the /proc/apm device will provide
2449	  battery status information, and user-space programs will receive
2450	  notification of APM "events" (e.g. battery status change).
2451
2452	  If you select "Y" here, you can disable actual use of the APM
2453	  BIOS by passing the "apm=off" option to the kernel at boot time.
2454
2455	  Note that the APM support is almost completely disabled for
2456	  machines with more than one CPU.
2457
2458	  In order to use APM, you will need supporting software. For location
2459	  and more information, read <file:Documentation/power/apm-acpi.txt>
2460	  and the Battery Powered Linux mini-HOWTO, available from
2461	  <http://www.tldp.org/docs.html#howto>.
2462
2463	  This driver does not spin down disk drives (see the hdparm(8)
2464	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2465	  VESA-compliant "green" monitors.
2466
2467	  This driver does not support the TI 4000M TravelMate and the ACER
2468	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2469	  desktop machines also don't have compliant BIOSes, and this driver
2470	  may cause those machines to panic during the boot phase.
2471
2472	  Generally, if you don't have a battery in your machine, there isn't
2473	  much point in using this driver and you should say N. If you get
2474	  random kernel OOPSes or reboots that don't seem to be related to
2475	  anything, try disabling/enabling this option (or disabling/enabling
2476	  APM in your BIOS).
2477
2478	  Some other things you should try when experiencing seemingly random,
2479	  "weird" problems:
2480
2481	  1) make sure that you have enough swap space and that it is
2482	  enabled.
2483	  2) pass the "no-hlt" option to the kernel
2484	  3) switch on floating point emulation in the kernel and pass
2485	  the "no387" option to the kernel
2486	  4) pass the "floppy=nodma" option to the kernel
2487	  5) pass the "mem=4M" option to the kernel (thereby disabling
2488	  all but the first 4 MB of RAM)
2489	  6) make sure that the CPU is not over clocked.
2490	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2491	  8) disable the cache from your BIOS settings
2492	  9) install a fan for the video card or exchange video RAM
2493	  10) install a better fan for the CPU
2494	  11) exchange RAM chips
2495	  12) exchange the motherboard.
2496
2497	  To compile this driver as a module, choose M here: the
2498	  module will be called apm.
2499
2500if APM
2501
2502config APM_IGNORE_USER_SUSPEND
2503	bool "Ignore USER SUSPEND"
2504	---help---
2505	  This option will ignore USER SUSPEND requests. On machines with a
2506	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2507	  series notebooks, it is necessary to say Y because of a BIOS bug.
2508
2509config APM_DO_ENABLE
2510	bool "Enable PM at boot time"
2511	---help---
2512	  Enable APM features at boot time. From page 36 of the APM BIOS
2513	  specification: "When disabled, the APM BIOS does not automatically
2514	  power manage devices, enter the Standby State, enter the Suspend
2515	  State, or take power saving steps in response to CPU Idle calls."
2516	  This driver will make CPU Idle calls when Linux is idle (unless this
2517	  feature is turned off -- see "Do CPU IDLE calls", below). This
2518	  should always save battery power, but more complicated APM features
2519	  will be dependent on your BIOS implementation. You may need to turn
2520	  this option off if your computer hangs at boot time when using APM
2521	  support, or if it beeps continuously instead of suspending. Turn
2522	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2523	  T400CDT. This is off by default since most machines do fine without
2524	  this feature.
2525
2526config APM_CPU_IDLE
2527	depends on CPU_IDLE
2528	bool "Make CPU Idle calls when idle"
2529	---help---
2530	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2531	  On some machines, this can activate improved power savings, such as
2532	  a slowed CPU clock rate, when the machine is idle. These idle calls
2533	  are made after the idle loop has run for some length of time (e.g.,
2534	  333 mS). On some machines, this will cause a hang at boot time or
2535	  whenever the CPU becomes idle. (On machines with more than one CPU,
2536	  this option does nothing.)
2537
2538config APM_DISPLAY_BLANK
2539	bool "Enable console blanking using APM"
2540	---help---
2541	  Enable console blanking using the APM. Some laptops can use this to
2542	  turn off the LCD backlight when the screen blanker of the Linux
2543	  virtual console blanks the screen. Note that this is only used by
2544	  the virtual console screen blanker, and won't turn off the backlight
2545	  when using the X Window system. This also doesn't have anything to
2546	  do with your VESA-compliant power-saving monitor. Further, this
2547	  option doesn't work for all laptops -- it might not turn off your
2548	  backlight at all, or it might print a lot of errors to the console,
2549	  especially if you are using gpm.
2550
2551config APM_ALLOW_INTS
2552	bool "Allow interrupts during APM BIOS calls"
2553	---help---
2554	  Normally we disable external interrupts while we are making calls to
2555	  the APM BIOS as a measure to lessen the effects of a badly behaving
2556	  BIOS implementation.  The BIOS should reenable interrupts if it
2557	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2558	  many of the newer IBM Thinkpads.  If you experience hangs when you
2559	  suspend, try setting this to Y.  Otherwise, say N.
2560
2561endif # APM
2562
2563source "drivers/cpufreq/Kconfig"
2564
2565source "drivers/cpuidle/Kconfig"
2566
2567source "drivers/idle/Kconfig"
2568
2569endmenu
2570
2571
2572menu "Bus options (PCI etc.)"
2573
2574config PCI
2575	bool "PCI support"
2576	default y
2577	---help---
2578	  Find out whether you have a PCI motherboard. PCI is the name of a
2579	  bus system, i.e. the way the CPU talks to the other stuff inside
2580	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2581	  VESA. If you have PCI, say Y, otherwise N.
2582
2583choice
2584	prompt "PCI access mode"
2585	depends on X86_32 && PCI
2586	default PCI_GOANY
2587	---help---
2588	  On PCI systems, the BIOS can be used to detect the PCI devices and
2589	  determine their configuration. However, some old PCI motherboards
2590	  have BIOS bugs and may crash if this is done. Also, some embedded
2591	  PCI-based systems don't have any BIOS at all. Linux can also try to
2592	  detect the PCI hardware directly without using the BIOS.
2593
2594	  With this option, you can specify how Linux should detect the
2595	  PCI devices. If you choose "BIOS", the BIOS will be used,
2596	  if you choose "Direct", the BIOS won't be used, and if you
2597	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2598	  If you choose "Any", the kernel will try MMCONFIG, then the
2599	  direct access method and falls back to the BIOS if that doesn't
2600	  work. If unsure, go with the default, which is "Any".
2601
2602config PCI_GOBIOS
2603	bool "BIOS"
2604
2605config PCI_GOMMCONFIG
2606	bool "MMConfig"
2607
2608config PCI_GODIRECT
2609	bool "Direct"
2610
2611config PCI_GOOLPC
2612	bool "OLPC XO-1"
2613	depends on OLPC
2614
2615config PCI_GOANY
2616	bool "Any"
2617
2618endchoice
2619
2620config PCI_BIOS
2621	def_bool y
2622	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2623
2624# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2625config PCI_DIRECT
2626	def_bool y
2627	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2628
2629config PCI_MMCONFIG
2630	bool "Support mmconfig PCI config space access" if X86_64
2631	default y
2632	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2633	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2634
2635config PCI_OLPC
2636	def_bool y
2637	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2638
2639config PCI_XEN
2640	def_bool y
2641	depends on PCI && XEN
2642	select SWIOTLB_XEN
2643
2644config PCI_DOMAINS
2645	def_bool y
2646	depends on PCI
2647
2648config MMCONF_FAM10H
2649	def_bool y
2650	depends on X86_64 && PCI_MMCONFIG && ACPI
2651
2652config PCI_CNB20LE_QUIRK
2653	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2654	depends on PCI
2655	help
2656	  Read the PCI windows out of the CNB20LE host bridge. This allows
2657	  PCI hotplug to work on systems with the CNB20LE chipset which do
2658	  not have ACPI.
2659
2660	  There's no public spec for this chipset, and this functionality
2661	  is known to be incomplete.
2662
2663	  You should say N unless you know you need this.
2664
2665source "drivers/pci/Kconfig"
2666
2667config ISA_BUS
2668	bool "ISA bus support on modern systems" if EXPERT
2669	help
2670	  Expose ISA bus device drivers and options available for selection and
2671	  configuration. Enable this option if your target machine has an ISA
2672	  bus. ISA is an older system, displaced by PCI and newer bus
2673	  architectures -- if your target machine is modern, it probably does
2674	  not have an ISA bus.
2675
2676	  If unsure, say N.
2677
2678# x86_64 have no ISA slots, but can have ISA-style DMA.
2679config ISA_DMA_API
2680	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2681	default y
2682	help
2683	  Enables ISA-style DMA support for devices requiring such controllers.
2684	  If unsure, say Y.
2685
2686if X86_32
2687
2688config ISA
2689	bool "ISA support"
2690	---help---
2691	  Find out whether you have ISA slots on your motherboard.  ISA is the
2692	  name of a bus system, i.e. the way the CPU talks to the other stuff
2693	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2694	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2695	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2696
2697config EISA
2698	bool "EISA support"
2699	depends on ISA
2700	---help---
2701	  The Extended Industry Standard Architecture (EISA) bus was
2702	  developed as an open alternative to the IBM MicroChannel bus.
2703
2704	  The EISA bus provided some of the features of the IBM MicroChannel
2705	  bus while maintaining backward compatibility with cards made for
2706	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2707	  1995 when it was made obsolete by the PCI bus.
2708
2709	  Say Y here if you are building a kernel for an EISA-based machine.
2710
2711	  Otherwise, say N.
2712
2713source "drivers/eisa/Kconfig"
2714
2715config SCx200
2716	tristate "NatSemi SCx200 support"
2717	---help---
2718	  This provides basic support for National Semiconductor's
2719	  (now AMD's) Geode processors.  The driver probes for the
2720	  PCI-IDs of several on-chip devices, so its a good dependency
2721	  for other scx200_* drivers.
2722
2723	  If compiled as a module, the driver is named scx200.
2724
2725config SCx200HR_TIMER
2726	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2727	depends on SCx200
2728	default y
2729	---help---
2730	  This driver provides a clocksource built upon the on-chip
2731	  27MHz high-resolution timer.  Its also a workaround for
2732	  NSC Geode SC-1100's buggy TSC, which loses time when the
2733	  processor goes idle (as is done by the scheduler).  The
2734	  other workaround is idle=poll boot option.
2735
2736config OLPC
2737	bool "One Laptop Per Child support"
2738	depends on !X86_PAE
2739	select GPIOLIB
2740	select OF
2741	select OF_PROMTREE
2742	select IRQ_DOMAIN
2743	---help---
2744	  Add support for detecting the unique features of the OLPC
2745	  XO hardware.
2746
2747config OLPC_XO1_PM
2748	bool "OLPC XO-1 Power Management"
2749	depends on OLPC && MFD_CS5535 && PM_SLEEP
2750	select MFD_CORE
2751	---help---
2752	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2753
2754config OLPC_XO1_RTC
2755	bool "OLPC XO-1 Real Time Clock"
2756	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2757	---help---
2758	  Add support for the XO-1 real time clock, which can be used as a
2759	  programmable wakeup source.
2760
2761config OLPC_XO1_SCI
2762	bool "OLPC XO-1 SCI extras"
2763	depends on OLPC && OLPC_XO1_PM
2764	depends on INPUT=y
2765	select POWER_SUPPLY
2766	select GPIO_CS5535
2767	select MFD_CORE
2768	---help---
2769	  Add support for SCI-based features of the OLPC XO-1 laptop:
2770	   - EC-driven system wakeups
2771	   - Power button
2772	   - Ebook switch
2773	   - Lid switch
2774	   - AC adapter status updates
2775	   - Battery status updates
2776
2777config OLPC_XO15_SCI
2778	bool "OLPC XO-1.5 SCI extras"
2779	depends on OLPC && ACPI
2780	select POWER_SUPPLY
2781	---help---
2782	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2783	   - EC-driven system wakeups
2784	   - AC adapter status updates
2785	   - Battery status updates
2786
2787config ALIX
2788	bool "PCEngines ALIX System Support (LED setup)"
2789	select GPIOLIB
2790	---help---
2791	  This option enables system support for the PCEngines ALIX.
2792	  At present this just sets up LEDs for GPIO control on
2793	  ALIX2/3/6 boards.  However, other system specific setup should
2794	  get added here.
2795
2796	  Note: You must still enable the drivers for GPIO and LED support
2797	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2798
2799	  Note: You have to set alix.force=1 for boards with Award BIOS.
2800
2801config NET5501
2802	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2803	select GPIOLIB
2804	---help---
2805	  This option enables system support for the Soekris Engineering net5501.
2806
2807config GEOS
2808	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2809	select GPIOLIB
2810	depends on DMI
2811	---help---
2812	  This option enables system support for the Traverse Technologies GEOS.
2813
2814config TS5500
2815	bool "Technologic Systems TS-5500 platform support"
2816	depends on MELAN
2817	select CHECK_SIGNATURE
2818	select NEW_LEDS
2819	select LEDS_CLASS
2820	---help---
2821	  This option enables system support for the Technologic Systems TS-5500.
2822
2823endif # X86_32
2824
2825config AMD_NB
2826	def_bool y
2827	depends on CPU_SUP_AMD && PCI
2828
2829source "drivers/pcmcia/Kconfig"
2830
2831config RAPIDIO
2832	tristate "RapidIO support"
2833	depends on PCI
2834	default n
2835	help
2836	  If enabled this option will include drivers and the core
2837	  infrastructure code to support RapidIO interconnect devices.
2838
2839source "drivers/rapidio/Kconfig"
2840
2841config X86_SYSFB
2842	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2843	help
2844	  Firmwares often provide initial graphics framebuffers so the BIOS,
2845	  bootloader or kernel can show basic video-output during boot for
2846	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2847	  Extensions and EFI-framebuffers for this, which are mostly limited
2848	  to x86.
2849	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2850	  framebuffers so the new generic system-framebuffer drivers can be
2851	  used on x86. If the framebuffer is not compatible with the generic
2852	  modes, it is adverticed as fallback platform framebuffer so legacy
2853	  drivers like efifb, vesafb and uvesafb can pick it up.
2854	  If this option is not selected, all system framebuffers are always
2855	  marked as fallback platform framebuffers as usual.
2856
2857	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2858	  not be able to pick up generic system framebuffers if this option
2859	  is selected. You are highly encouraged to enable simplefb as
2860	  replacement if you select this option. simplefb can correctly deal
2861	  with generic system framebuffers. But you should still keep vesafb
2862	  and others enabled as fallback if a system framebuffer is
2863	  incompatible with simplefb.
2864
2865	  If unsure, say Y.
2866
2867endmenu
2868
2869
2870menu "Executable file formats / Emulations"
2871
2872source "fs/Kconfig.binfmt"
2873
2874config IA32_EMULATION
2875	bool "IA32 Emulation"
2876	depends on X86_64
2877	select ARCH_WANT_OLD_COMPAT_IPC
2878	select BINFMT_ELF
2879	select COMPAT_BINFMT_ELF
2880	select COMPAT_OLD_SIGACTION
2881	---help---
2882	  Include code to run legacy 32-bit programs under a
2883	  64-bit kernel. You should likely turn this on, unless you're
2884	  100% sure that you don't have any 32-bit programs left.
2885
2886config IA32_AOUT
2887	tristate "IA32 a.out support"
2888	depends on IA32_EMULATION
2889	---help---
2890	  Support old a.out binaries in the 32bit emulation.
2891
2892config X86_X32
2893	bool "x32 ABI for 64-bit mode"
2894	depends on X86_64
2895	---help---
2896	  Include code to run binaries for the x32 native 32-bit ABI
2897	  for 64-bit processors.  An x32 process gets access to the
2898	  full 64-bit register file and wide data path while leaving
2899	  pointers at 32 bits for smaller memory footprint.
2900
2901	  You will need a recent binutils (2.22 or later) with
2902	  elf32_x86_64 support enabled to compile a kernel with this
2903	  option set.
2904
2905config COMPAT_32
2906	def_bool y
2907	depends on IA32_EMULATION || X86_32
2908	select HAVE_UID16
2909	select OLD_SIGSUSPEND3
2910
2911config COMPAT
2912	def_bool y
2913	depends on IA32_EMULATION || X86_X32
2914
2915if COMPAT
2916config COMPAT_FOR_U64_ALIGNMENT
2917	def_bool y
2918
2919config SYSVIPC_COMPAT
2920	def_bool y
2921	depends on SYSVIPC
2922endif
2923
2924endmenu
2925
2926
2927config HAVE_ATOMIC_IOMAP
2928	def_bool y
2929	depends on X86_32
2930
2931config X86_DEV_DMA_OPS
2932	bool
2933	depends on X86_64 || STA2X11
2934
2935config X86_DMA_REMAP
2936	bool
2937	depends on STA2X11
2938
2939config HAVE_GENERIC_GUP
2940	def_bool y
2941
2942source "net/Kconfig"
2943
2944source "drivers/Kconfig"
2945
2946source "drivers/firmware/Kconfig"
2947
2948source "fs/Kconfig"
2949
2950source "arch/x86/Kconfig.debug"
2951
2952source "security/Kconfig"
2953
2954source "crypto/Kconfig"
2955
2956source "arch/x86/kvm/Kconfig"
2957
2958source "lib/Kconfig"
2959