xref: /openbmc/linux/arch/x86/Kconfig (revision 6396bb221514d2876fd6dc0aa2a1f240d99b37bb)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select X86_DEV_DMA_OPS
34	select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40#   ported to 32-bit as well. )
41#
42config X86
43	def_bool y
44	#
45	# Note: keep this list sorted alphabetically
46	#
47	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
48	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
49	select ANON_INODES
50	select ARCH_CLOCKSOURCE_DATA
51	select ARCH_DISCARD_MEMBLOCK
52	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53	select ARCH_HAS_DEBUG_VIRTUAL
54	select ARCH_HAS_DEVMEM_IS_ALLOWED
55	select ARCH_HAS_ELF_RANDOMIZE
56	select ARCH_HAS_FAST_MULTIPLIER
57	select ARCH_HAS_FILTER_PGPROT
58	select ARCH_HAS_FORTIFY_SOURCE
59	select ARCH_HAS_GCOV_PROFILE_ALL
60	select ARCH_HAS_KCOV			if X86_64
61	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62	select ARCH_HAS_PMEM_API		if X86_64
63	select ARCH_HAS_PTE_SPECIAL
64	select ARCH_HAS_REFCOUNT
65	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
66	select ARCH_HAS_UACCESS_MCSAFE		if X86_64
67	select ARCH_HAS_SET_MEMORY
68	select ARCH_HAS_SG_CHAIN
69	select ARCH_HAS_STRICT_KERNEL_RWX
70	select ARCH_HAS_STRICT_MODULE_RWX
71	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
72	select ARCH_HAS_UBSAN_SANITIZE_ALL
73	select ARCH_HAS_ZONE_DEVICE		if X86_64
74	select ARCH_HAVE_NMI_SAFE_CMPXCHG
75	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
76	select ARCH_MIGHT_HAVE_PC_PARPORT
77	select ARCH_MIGHT_HAVE_PC_SERIO
78	select ARCH_SUPPORTS_ATOMIC_RMW
79	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
80	select ARCH_USE_BUILTIN_BSWAP
81	select ARCH_USE_QUEUED_RWLOCKS
82	select ARCH_USE_QUEUED_SPINLOCKS
83	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
84	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
85	select ARCH_WANTS_THP_SWAP		if X86_64
86	select BUILDTIME_EXTABLE_SORT
87	select CLKEVT_I8253
88	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
89	select CLOCKSOURCE_WATCHDOG
90	select DCACHE_WORD_ACCESS
91	select DMA_DIRECT_OPS
92	select EDAC_ATOMIC_SCRUB
93	select EDAC_SUPPORT
94	select GENERIC_CLOCKEVENTS
95	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
96	select GENERIC_CLOCKEVENTS_MIN_ADJUST
97	select GENERIC_CMOS_UPDATE
98	select GENERIC_CPU_AUTOPROBE
99	select GENERIC_CPU_VULNERABILITIES
100	select GENERIC_EARLY_IOREMAP
101	select GENERIC_FIND_FIRST_BIT
102	select GENERIC_IOMAP
103	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
104	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
105	select GENERIC_IRQ_MIGRATION		if SMP
106	select GENERIC_IRQ_PROBE
107	select GENERIC_IRQ_RESERVATION_MODE
108	select GENERIC_IRQ_SHOW
109	select GENERIC_PENDING_IRQ		if SMP
110	select GENERIC_SMP_IDLE_THREAD
111	select GENERIC_STRNCPY_FROM_USER
112	select GENERIC_STRNLEN_USER
113	select GENERIC_TIME_VSYSCALL
114	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
115	select HAVE_ACPI_APEI			if ACPI
116	select HAVE_ACPI_APEI_NMI		if ACPI
117	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
118	select HAVE_ARCH_AUDITSYSCALL
119	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
120	select HAVE_ARCH_JUMP_LABEL
121	select HAVE_ARCH_KASAN			if X86_64
122	select HAVE_ARCH_KGDB
123	select HAVE_ARCH_MMAP_RND_BITS		if MMU
124	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
125	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
126	select HAVE_ARCH_SECCOMP_FILTER
127	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
128	select HAVE_ARCH_TRACEHOOK
129	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
130	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
131	select HAVE_ARCH_VMAP_STACK		if X86_64
132	select HAVE_ARCH_WITHIN_STACK_FRAMES
133	select HAVE_CC_STACKPROTECTOR
134	select HAVE_CMPXCHG_DOUBLE
135	select HAVE_CMPXCHG_LOCAL
136	select HAVE_CONTEXT_TRACKING		if X86_64
137	select HAVE_COPY_THREAD_TLS
138	select HAVE_C_RECORDMCOUNT
139	select HAVE_DEBUG_KMEMLEAK
140	select HAVE_DEBUG_STACKOVERFLOW
141	select HAVE_DMA_CONTIGUOUS
142	select HAVE_DYNAMIC_FTRACE
143	select HAVE_DYNAMIC_FTRACE_WITH_REGS
144	select HAVE_EBPF_JIT
145	select HAVE_EFFICIENT_UNALIGNED_ACCESS
146	select HAVE_EXIT_THREAD
147	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
148	select HAVE_FTRACE_MCOUNT_RECORD
149	select HAVE_FUNCTION_GRAPH_TRACER
150	select HAVE_FUNCTION_TRACER
151	select HAVE_GCC_PLUGINS
152	select HAVE_HW_BREAKPOINT
153	select HAVE_IDE
154	select HAVE_IOREMAP_PROT
155	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
156	select HAVE_IRQ_TIME_ACCOUNTING
157	select HAVE_KERNEL_BZIP2
158	select HAVE_KERNEL_GZIP
159	select HAVE_KERNEL_LZ4
160	select HAVE_KERNEL_LZMA
161	select HAVE_KERNEL_LZO
162	select HAVE_KERNEL_XZ
163	select HAVE_KPROBES
164	select HAVE_KPROBES_ON_FTRACE
165	select HAVE_FUNCTION_ERROR_INJECTION
166	select HAVE_KRETPROBES
167	select HAVE_KVM
168	select HAVE_LIVEPATCH			if X86_64
169	select HAVE_MEMBLOCK
170	select HAVE_MEMBLOCK_NODE_MAP
171	select HAVE_MIXED_BREAKPOINTS_REGS
172	select HAVE_MOD_ARCH_SPECIFIC
173	select HAVE_NMI
174	select HAVE_OPROFILE
175	select HAVE_OPTPROBES
176	select HAVE_PCSPKR_PLATFORM
177	select HAVE_PERF_EVENTS
178	select HAVE_PERF_EVENTS_NMI
179	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
180	select HAVE_PERF_REGS
181	select HAVE_PERF_USER_STACK_DUMP
182	select HAVE_RCU_TABLE_FREE
183	select HAVE_REGS_AND_STACK_ACCESS_API
184	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
185	select HAVE_STACK_VALIDATION		if X86_64
186	select HAVE_RSEQ
187	select HAVE_SYSCALL_TRACEPOINTS
188	select HAVE_UNSTABLE_SCHED_CLOCK
189	select HAVE_USER_RETURN_NOTIFIER
190	select IRQ_FORCED_THREADING
191	select NEED_SG_DMA_LENGTH
192	select PCI_LOCKLESS_CONFIG
193	select PERF_EVENTS
194	select RTC_LIB
195	select RTC_MC146818_LIB
196	select SPARSE_IRQ
197	select SRCU
198	select SYSCTL_EXCEPTION_TRACE
199	select THREAD_INFO_IN_TASK
200	select USER_STACKTRACE_SUPPORT
201	select VIRT_TO_BUS
202	select X86_FEATURE_NAMES		if PROC_FS
203
204config INSTRUCTION_DECODER
205	def_bool y
206	depends on KPROBES || PERF_EVENTS || UPROBES
207
208config OUTPUT_FORMAT
209	string
210	default "elf32-i386" if X86_32
211	default "elf64-x86-64" if X86_64
212
213config ARCH_DEFCONFIG
214	string
215	default "arch/x86/configs/i386_defconfig" if X86_32
216	default "arch/x86/configs/x86_64_defconfig" if X86_64
217
218config LOCKDEP_SUPPORT
219	def_bool y
220
221config STACKTRACE_SUPPORT
222	def_bool y
223
224config MMU
225	def_bool y
226
227config ARCH_MMAP_RND_BITS_MIN
228	default 28 if 64BIT
229	default 8
230
231config ARCH_MMAP_RND_BITS_MAX
232	default 32 if 64BIT
233	default 16
234
235config ARCH_MMAP_RND_COMPAT_BITS_MIN
236	default 8
237
238config ARCH_MMAP_RND_COMPAT_BITS_MAX
239	default 16
240
241config SBUS
242	bool
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 ARCH_HAS_FILTER_PGPROT
276	def_bool y
277
278config HAVE_SETUP_PER_CPU_AREA
279	def_bool y
280
281config NEED_PER_CPU_EMBED_FIRST_CHUNK
282	def_bool y
283
284config NEED_PER_CPU_PAGE_FIRST_CHUNK
285	def_bool y
286
287config ARCH_HIBERNATION_POSSIBLE
288	def_bool y
289
290config ARCH_SUSPEND_POSSIBLE
291	def_bool y
292
293config ARCH_WANT_HUGE_PMD_SHARE
294	def_bool y
295
296config ARCH_WANT_GENERAL_HUGETLB
297	def_bool y
298
299config ZONE_DMA32
300	def_bool y if X86_64
301
302config AUDIT_ARCH
303	def_bool y if X86_64
304
305config ARCH_SUPPORTS_OPTIMIZED_INLINING
306	def_bool y
307
308config ARCH_SUPPORTS_DEBUG_PAGEALLOC
309	def_bool y
310
311config KASAN_SHADOW_OFFSET
312	hex
313	depends on KASAN
314	default 0xdffffc0000000000
315
316config HAVE_INTEL_TXT
317	def_bool y
318	depends on INTEL_IOMMU && ACPI
319
320config X86_32_SMP
321	def_bool y
322	depends on X86_32 && SMP
323
324config X86_64_SMP
325	def_bool y
326	depends on X86_64 && SMP
327
328config X86_32_LAZY_GS
329	def_bool y
330	depends on X86_32 && CC_STACKPROTECTOR_NONE
331
332config ARCH_SUPPORTS_UPROBES
333	def_bool y
334
335config FIX_EARLYCON_MEM
336	def_bool y
337
338config DYNAMIC_PHYSICAL_MASK
339	bool
340
341config PGTABLE_LEVELS
342	int
343	default 5 if X86_5LEVEL
344	default 4 if X86_64
345	default 3 if X86_PAE
346	default 2
347
348source "init/Kconfig"
349source "kernel/Kconfig.freezer"
350
351menu "Processor type and features"
352
353config ZONE_DMA
354	bool "DMA memory allocation support" if EXPERT
355	default y
356	help
357	  DMA memory allocation support allows devices with less than 32-bit
358	  addressing to allocate within the first 16MB of address space.
359	  Disable if no such devices will be used.
360
361	  If unsure, say Y.
362
363config SMP
364	bool "Symmetric multi-processing support"
365	---help---
366	  This enables support for systems with more than one CPU. If you have
367	  a system with only one CPU, say N. If you have a system with more
368	  than one CPU, say Y.
369
370	  If you say N here, the kernel will run on uni- and multiprocessor
371	  machines, but will use only one CPU of a multiprocessor machine. If
372	  you say Y here, the kernel will run on many, but not all,
373	  uniprocessor machines. On a uniprocessor machine, the kernel
374	  will run faster if you say N here.
375
376	  Note that if you say Y here and choose architecture "586" or
377	  "Pentium" under "Processor family", the kernel will not work on 486
378	  architectures. Similarly, multiprocessor kernels for the "PPro"
379	  architecture may not work on all Pentium based boards.
380
381	  People using multiprocessor machines who say Y here should also say
382	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
383	  Management" code will be disabled if you say Y here.
384
385	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
386	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
387	  <http://www.tldp.org/docs.html#howto>.
388
389	  If you don't know what to do here, say N.
390
391config X86_FEATURE_NAMES
392	bool "Processor feature human-readable names" if EMBEDDED
393	default y
394	---help---
395	  This option compiles in a table of x86 feature bits and corresponding
396	  names.  This is required to support /proc/cpuinfo and a few kernel
397	  messages.  You can disable this to save space, at the expense of
398	  making those few kernel messages show numeric feature bits instead.
399
400	  If in doubt, say Y.
401
402config X86_X2APIC
403	bool "Support x2apic"
404	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
405	---help---
406	  This enables x2apic support on CPUs that have this feature.
407
408	  This allows 32-bit apic IDs (so it can support very large systems),
409	  and accesses the local apic via MSRs not via mmio.
410
411	  If you don't know what to do here, say N.
412
413config X86_MPPARSE
414	bool "Enable MPS table" if ACPI || SFI
415	default y
416	depends on X86_LOCAL_APIC
417	---help---
418	  For old smp systems that do not have proper acpi support. Newer systems
419	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
420
421config GOLDFISH
422       def_bool y
423       depends on X86_GOLDFISH
424
425config RETPOLINE
426	bool "Avoid speculative indirect branches in kernel"
427	default y
428	select STACK_VALIDATION if HAVE_STACK_VALIDATION
429	help
430	  Compile kernel with the retpoline compiler options to guard against
431	  kernel-to-user data leaks by avoiding speculative indirect
432	  branches. Requires a compiler with -mindirect-branch=thunk-extern
433	  support for full protection. The kernel may run slower.
434
435	  Without compiler support, at least indirect branches in assembler
436	  code are eliminated. Since this includes the syscall entry path,
437	  it is not entirely pointless.
438
439config INTEL_RDT
440	bool "Intel Resource Director Technology support"
441	default n
442	depends on X86 && CPU_SUP_INTEL
443	select KERNFS
444	help
445	  Select to enable resource allocation and monitoring which are
446	  sub-features of Intel Resource Director Technology(RDT). More
447	  information about RDT can be found in the Intel x86
448	  Architecture Software Developer Manual.
449
450	  Say N if unsure.
451
452if X86_32
453config X86_BIGSMP
454	bool "Support for big SMP systems with more than 8 CPUs"
455	depends on SMP
456	---help---
457	  This option is needed for the systems that have more than 8 CPUs
458
459config X86_EXTENDED_PLATFORM
460	bool "Support for extended (non-PC) x86 platforms"
461	default y
462	---help---
463	  If you disable this option then the kernel will only support
464	  standard PC platforms. (which covers the vast majority of
465	  systems out there.)
466
467	  If you enable this option then you'll be able to select support
468	  for the following (non-PC) 32 bit x86 platforms:
469		Goldfish (Android emulator)
470		AMD Elan
471		RDC R-321x SoC
472		SGI 320/540 (Visual Workstation)
473		STA2X11-based (e.g. Northville)
474		Moorestown MID devices
475
476	  If you have one of these systems, or if you want to build a
477	  generic distribution kernel, say Y here - otherwise say N.
478endif
479
480if X86_64
481config X86_EXTENDED_PLATFORM
482	bool "Support for extended (non-PC) x86 platforms"
483	default y
484	---help---
485	  If you disable this option then the kernel will only support
486	  standard PC platforms. (which covers the vast majority of
487	  systems out there.)
488
489	  If you enable this option then you'll be able to select support
490	  for the following (non-PC) 64 bit x86 platforms:
491		Numascale NumaChip
492		ScaleMP vSMP
493		SGI Ultraviolet
494
495	  If you have one of these systems, or if you want to build a
496	  generic distribution kernel, say Y here - otherwise say N.
497endif
498# This is an alphabetically sorted list of 64 bit extended platforms
499# Please maintain the alphabetic order if and when there are additions
500config X86_NUMACHIP
501	bool "Numascale NumaChip"
502	depends on X86_64
503	depends on X86_EXTENDED_PLATFORM
504	depends on NUMA
505	depends on SMP
506	depends on X86_X2APIC
507	depends on PCI_MMCONFIG
508	---help---
509	  Adds support for Numascale NumaChip large-SMP systems. Needed to
510	  enable more than ~168 cores.
511	  If you don't have one of these, you should say N here.
512
513config X86_VSMP
514	bool "ScaleMP vSMP"
515	select HYPERVISOR_GUEST
516	select PARAVIRT
517	depends on X86_64 && PCI
518	depends on X86_EXTENDED_PLATFORM
519	depends on SMP
520	---help---
521	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
522	  supposed to run on these EM64T-based machines.  Only choose this option
523	  if you have one of these machines.
524
525config X86_UV
526	bool "SGI Ultraviolet"
527	depends on X86_64
528	depends on X86_EXTENDED_PLATFORM
529	depends on NUMA
530	depends on EFI
531	depends on X86_X2APIC
532	depends on PCI
533	---help---
534	  This option is needed in order to support SGI Ultraviolet systems.
535	  If you don't have one of these, you should say N here.
536
537# Following is an alphabetically sorted list of 32 bit extended platforms
538# Please maintain the alphabetic order if and when there are additions
539
540config X86_GOLDFISH
541       bool "Goldfish (Virtual Platform)"
542       depends on X86_EXTENDED_PLATFORM
543       ---help---
544	 Enable support for the Goldfish virtual platform used primarily
545	 for Android development. Unless you are building for the Android
546	 Goldfish emulator say N here.
547
548config X86_INTEL_CE
549	bool "CE4100 TV platform"
550	depends on PCI
551	depends on PCI_GODIRECT
552	depends on X86_IO_APIC
553	depends on X86_32
554	depends on X86_EXTENDED_PLATFORM
555	select X86_REBOOTFIXUPS
556	select OF
557	select OF_EARLY_FLATTREE
558	---help---
559	  Select for the Intel CE media processor (CE4100) SOC.
560	  This option compiles in support for the CE4100 SOC for settop
561	  boxes and media devices.
562
563config X86_INTEL_MID
564	bool "Intel MID platform support"
565	depends on X86_EXTENDED_PLATFORM
566	depends on X86_PLATFORM_DEVICES
567	depends on PCI
568	depends on X86_64 || (PCI_GOANY && X86_32)
569	depends on X86_IO_APIC
570	select SFI
571	select I2C
572	select DW_APB_TIMER
573	select APB_TIMER
574	select INTEL_SCU_IPC
575	select MFD_INTEL_MSIC
576	---help---
577	  Select to build a kernel capable of supporting Intel MID (Mobile
578	  Internet Device) platform systems which do not have the PCI legacy
579	  interfaces. If you are building for a PC class system say N here.
580
581	  Intel MID platforms are based on an Intel processor and chipset which
582	  consume less power than most of the x86 derivatives.
583
584config X86_INTEL_QUARK
585	bool "Intel Quark platform support"
586	depends on X86_32
587	depends on X86_EXTENDED_PLATFORM
588	depends on X86_PLATFORM_DEVICES
589	depends on X86_TSC
590	depends on PCI
591	depends on PCI_GOANY
592	depends on X86_IO_APIC
593	select IOSF_MBI
594	select INTEL_IMR
595	select COMMON_CLK
596	---help---
597	  Select to include support for Quark X1000 SoC.
598	  Say Y here if you have a Quark based system such as the Arduino
599	  compatible Intel Galileo.
600
601config X86_INTEL_LPSS
602	bool "Intel Low Power Subsystem Support"
603	depends on X86 && ACPI
604	select COMMON_CLK
605	select PINCTRL
606	select IOSF_MBI
607	---help---
608	  Select to build support for Intel Low Power Subsystem such as
609	  found on Intel Lynxpoint PCH. Selecting this option enables
610	  things like clock tree (common clock framework) and pincontrol
611	  which are needed by the LPSS peripheral drivers.
612
613config X86_AMD_PLATFORM_DEVICE
614	bool "AMD ACPI2Platform devices support"
615	depends on ACPI
616	select COMMON_CLK
617	select PINCTRL
618	---help---
619	  Select to interpret AMD specific ACPI device to platform device
620	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
621	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
622	  implemented under PINCTRL subsystem.
623
624config IOSF_MBI
625	tristate "Intel SoC IOSF Sideband support for SoC platforms"
626	depends on PCI
627	---help---
628	  This option enables sideband register access support for Intel SoC
629	  platforms. On these platforms the IOSF sideband is used in lieu of
630	  MSR's for some register accesses, mostly but not limited to thermal
631	  and power. Drivers may query the availability of this device to
632	  determine if they need the sideband in order to work on these
633	  platforms. The sideband is available on the following SoC products.
634	  This list is not meant to be exclusive.
635	   - BayTrail
636	   - Braswell
637	   - Quark
638
639	  You should say Y if you are running a kernel on one of these SoC's.
640
641config IOSF_MBI_DEBUG
642	bool "Enable IOSF sideband access through debugfs"
643	depends on IOSF_MBI && DEBUG_FS
644	---help---
645	  Select this option to expose the IOSF sideband access registers (MCR,
646	  MDR, MCRX) through debugfs to write and read register information from
647	  different units on the SoC. This is most useful for obtaining device
648	  state information for debug and analysis. As this is a general access
649	  mechanism, users of this option would have specific knowledge of the
650	  device they want to access.
651
652	  If you don't require the option or are in doubt, say N.
653
654config X86_RDC321X
655	bool "RDC R-321x SoC"
656	depends on X86_32
657	depends on X86_EXTENDED_PLATFORM
658	select M486
659	select X86_REBOOTFIXUPS
660	---help---
661	  This option is needed for RDC R-321x system-on-chip, also known
662	  as R-8610-(G).
663	  If you don't have one of these chips, you should say N here.
664
665config X86_32_NON_STANDARD
666	bool "Support non-standard 32-bit SMP architectures"
667	depends on X86_32 && SMP
668	depends on X86_EXTENDED_PLATFORM
669	---help---
670	  This option compiles in the bigsmp and STA2X11 default
671	  subarchitectures.  It is intended for a generic binary
672	  kernel. If you select them all, kernel will probe it one by
673	  one and will fallback to default.
674
675# Alphabetically sorted list of Non standard 32 bit platforms
676
677config X86_SUPPORTS_MEMORY_FAILURE
678	def_bool y
679	# MCE code calls memory_failure():
680	depends on X86_MCE
681	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
682	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
683	depends on X86_64 || !SPARSEMEM
684	select ARCH_SUPPORTS_MEMORY_FAILURE
685
686config STA2X11
687	bool "STA2X11 Companion Chip Support"
688	depends on X86_32_NON_STANDARD && PCI
689	select ARCH_HAS_PHYS_TO_DMA
690	select X86_DEV_DMA_OPS
691	select X86_DMA_REMAP
692	select SWIOTLB
693	select MFD_STA2X11
694	select GPIOLIB
695	default n
696	---help---
697	  This adds support for boards based on the STA2X11 IO-Hub,
698	  a.k.a. "ConneXt". The chip is used in place of the standard
699	  PC chipset, so all "standard" peripherals are missing. If this
700	  option is selected the kernel will still be able to boot on
701	  standard PC machines.
702
703config X86_32_IRIS
704	tristate "Eurobraille/Iris poweroff module"
705	depends on X86_32
706	---help---
707	  The Iris machines from EuroBraille do not have APM or ACPI support
708	  to shut themselves down properly.  A special I/O sequence is
709	  needed to do so, which is what this module does at
710	  kernel shutdown.
711
712	  This is only for Iris machines from EuroBraille.
713
714	  If unused, say N.
715
716config SCHED_OMIT_FRAME_POINTER
717	def_bool y
718	prompt "Single-depth WCHAN output"
719	depends on X86
720	---help---
721	  Calculate simpler /proc/<PID>/wchan values. If this option
722	  is disabled then wchan values will recurse back to the
723	  caller function. This provides more accurate wchan values,
724	  at the expense of slightly more scheduling overhead.
725
726	  If in doubt, say "Y".
727
728menuconfig HYPERVISOR_GUEST
729	bool "Linux guest support"
730	---help---
731	  Say Y here to enable options for running Linux under various hyper-
732	  visors. This option enables basic hypervisor detection and platform
733	  setup.
734
735	  If you say N, all options in this submenu will be skipped and
736	  disabled, and Linux guest support won't be built in.
737
738if HYPERVISOR_GUEST
739
740config PARAVIRT
741	bool "Enable paravirtualization code"
742	---help---
743	  This changes the kernel so it can modify itself when it is run
744	  under a hypervisor, potentially improving performance significantly
745	  over full virtualization.  However, when run without a hypervisor
746	  the kernel is theoretically slower and slightly larger.
747
748config PARAVIRT_DEBUG
749	bool "paravirt-ops debugging"
750	depends on PARAVIRT && DEBUG_KERNEL
751	---help---
752	  Enable to debug paravirt_ops internals.  Specifically, BUG if
753	  a paravirt_op is missing when it is called.
754
755config PARAVIRT_SPINLOCKS
756	bool "Paravirtualization layer for spinlocks"
757	depends on PARAVIRT && SMP
758	---help---
759	  Paravirtualized spinlocks allow a pvops backend to replace the
760	  spinlock implementation with something virtualization-friendly
761	  (for example, block the virtual CPU rather than spinning).
762
763	  It has a minimal impact on native kernels and gives a nice performance
764	  benefit on paravirtualized KVM / Xen kernels.
765
766	  If you are unsure how to answer this question, answer Y.
767
768config QUEUED_LOCK_STAT
769	bool "Paravirt queued spinlock statistics"
770	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
771	---help---
772	  Enable the collection of statistical data on the slowpath
773	  behavior of paravirtualized queued spinlocks and report
774	  them on debugfs.
775
776source "arch/x86/xen/Kconfig"
777
778config KVM_GUEST
779	bool "KVM Guest support (including kvmclock)"
780	depends on PARAVIRT
781	select PARAVIRT_CLOCK
782	default y
783	---help---
784	  This option enables various optimizations for running under the KVM
785	  hypervisor. It includes a paravirtualized clock, so that instead
786	  of relying on a PIT (or probably other) emulation by the
787	  underlying device model, the host provides the guest with
788	  timing infrastructure such as time of day, and system time
789
790config KVM_DEBUG_FS
791	bool "Enable debug information for KVM Guests in debugfs"
792	depends on KVM_GUEST && DEBUG_FS
793	default n
794	---help---
795	  This option enables collection of various statistics for KVM guest.
796	  Statistics are displayed in debugfs filesystem. Enabling this option
797	  may incur significant overhead.
798
799config PARAVIRT_TIME_ACCOUNTING
800	bool "Paravirtual steal time accounting"
801	depends on PARAVIRT
802	default n
803	---help---
804	  Select this option to enable fine granularity task steal time
805	  accounting. Time spent executing other tasks in parallel with
806	  the current vCPU is discounted from the vCPU power. To account for
807	  that, there can be a small performance impact.
808
809	  If in doubt, say N here.
810
811config PARAVIRT_CLOCK
812	bool
813
814config JAILHOUSE_GUEST
815	bool "Jailhouse non-root cell support"
816	depends on X86_64 && PCI
817	select X86_PM_TIMER
818	---help---
819	  This option allows to run Linux as guest in a Jailhouse non-root
820	  cell. You can leave this option disabled if you only want to start
821	  Jailhouse and run Linux afterwards in the root cell.
822
823endif #HYPERVISOR_GUEST
824
825config NO_BOOTMEM
826	def_bool y
827
828source "arch/x86/Kconfig.cpu"
829
830config HPET_TIMER
831	def_bool X86_64
832	prompt "HPET Timer Support" if X86_32
833	---help---
834	  Use the IA-PC HPET (High Precision Event Timer) to manage
835	  time in preference to the PIT and RTC, if a HPET is
836	  present.
837	  HPET is the next generation timer replacing legacy 8254s.
838	  The HPET provides a stable time base on SMP
839	  systems, unlike the TSC, but it is more expensive to access,
840	  as it is off-chip.  The interface used is documented
841	  in the HPET spec, revision 1.
842
843	  You can safely choose Y here.  However, HPET will only be
844	  activated if the platform and the BIOS support this feature.
845	  Otherwise the 8254 will be used for timing services.
846
847	  Choose N to continue using the legacy 8254 timer.
848
849config HPET_EMULATE_RTC
850	def_bool y
851	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
852
853config APB_TIMER
854       def_bool y if X86_INTEL_MID
855       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
856       select DW_APB_TIMER
857       depends on X86_INTEL_MID && SFI
858       help
859         APB timer is the replacement for 8254, HPET on X86 MID platforms.
860         The APBT provides a stable time base on SMP
861         systems, unlike the TSC, but it is more expensive to access,
862         as it is off-chip. APB timers are always running regardless of CPU
863         C states, they are used as per CPU clockevent device when possible.
864
865# Mark as expert because too many people got it wrong.
866# The code disables itself when not needed.
867config DMI
868	default y
869	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
870	bool "Enable DMI scanning" if EXPERT
871	---help---
872	  Enabled scanning of DMI to identify machine quirks. Say Y
873	  here unless you have verified that your setup is not
874	  affected by entries in the DMI blacklist. Required by PNP
875	  BIOS code.
876
877config GART_IOMMU
878	bool "Old AMD GART IOMMU support"
879	select IOMMU_HELPER
880	select SWIOTLB
881	depends on X86_64 && PCI && AMD_NB
882	---help---
883	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
884	  GART based hardware IOMMUs.
885
886	  The GART supports full DMA access for devices with 32-bit access
887	  limitations, on systems with more than 3 GB. This is usually needed
888	  for USB, sound, many IDE/SATA chipsets and some other devices.
889
890	  Newer systems typically have a modern AMD IOMMU, supported via
891	  the CONFIG_AMD_IOMMU=y config option.
892
893	  In normal configurations this driver is only active when needed:
894	  there's more than 3 GB of memory and the system contains a
895	  32-bit limited device.
896
897	  If unsure, say Y.
898
899config CALGARY_IOMMU
900	bool "IBM Calgary IOMMU support"
901	select IOMMU_HELPER
902	select SWIOTLB
903	depends on X86_64 && PCI
904	---help---
905	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
906	  systems. Needed to run systems with more than 3GB of memory
907	  properly with 32-bit PCI devices that do not support DAC
908	  (Double Address Cycle). Calgary also supports bus level
909	  isolation, where all DMAs pass through the IOMMU.  This
910	  prevents them from going anywhere except their intended
911	  destination. This catches hard-to-find kernel bugs and
912	  mis-behaving drivers and devices that do not use the DMA-API
913	  properly to set up their DMA buffers.  The IOMMU can be
914	  turned off at boot time with the iommu=off parameter.
915	  Normally the kernel will make the right choice by itself.
916	  If unsure, say Y.
917
918config CALGARY_IOMMU_ENABLED_BY_DEFAULT
919	def_bool y
920	prompt "Should Calgary be enabled by default?"
921	depends on CALGARY_IOMMU
922	---help---
923	  Should Calgary be enabled by default? if you choose 'y', Calgary
924	  will be used (if it exists). If you choose 'n', Calgary will not be
925	  used even if it exists. If you choose 'n' and would like to use
926	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
927	  If unsure, say Y.
928
929config MAXSMP
930	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
931	depends on X86_64 && SMP && DEBUG_KERNEL
932	select CPUMASK_OFFSTACK
933	---help---
934	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
935	  If unsure, say N.
936
937#
938# The maximum number of CPUs supported:
939#
940# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
941# and which can be configured interactively in the
942# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
943#
944# The ranges are different on 32-bit and 64-bit kernels, depending on
945# hardware capabilities and scalability features of the kernel.
946#
947# ( If MAXSMP is enabled we just use the highest possible value and disable
948#   interactive configuration. )
949#
950
951config NR_CPUS_RANGE_BEGIN
952	int
953	default NR_CPUS_RANGE_END if MAXSMP
954	default    1 if !SMP
955	default    2
956
957config NR_CPUS_RANGE_END
958	int
959	depends on X86_32
960	default   64 if  SMP &&  X86_BIGSMP
961	default    8 if  SMP && !X86_BIGSMP
962	default    1 if !SMP
963
964config NR_CPUS_RANGE_END
965	int
966	depends on X86_64
967	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
968	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
969	default    1 if !SMP
970
971config NR_CPUS_DEFAULT
972	int
973	depends on X86_32
974	default   32 if  X86_BIGSMP
975	default    8 if  SMP
976	default    1 if !SMP
977
978config NR_CPUS_DEFAULT
979	int
980	depends on X86_64
981	default 8192 if  MAXSMP
982	default   64 if  SMP
983	default    1 if !SMP
984
985config NR_CPUS
986	int "Maximum number of CPUs" if SMP && !MAXSMP
987	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
988	default NR_CPUS_DEFAULT
989	---help---
990	  This allows you to specify the maximum number of CPUs which this
991	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
992	  supported value is 8192, otherwise the maximum value is 512.  The
993	  minimum value which makes sense is 2.
994
995	  This is purely to save memory: each supported CPU adds about 8KB
996	  to the kernel image.
997
998config SCHED_SMT
999	bool "SMT (Hyperthreading) scheduler support"
1000	depends on SMP
1001	---help---
1002	  SMT scheduler support improves the CPU scheduler's decision making
1003	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1004	  cost of slightly increased overhead in some places. If unsure say
1005	  N here.
1006
1007config SCHED_MC
1008	def_bool y
1009	prompt "Multi-core scheduler support"
1010	depends on SMP
1011	---help---
1012	  Multi-core scheduler support improves the CPU scheduler's decision
1013	  making when dealing with multi-core CPU chips at a cost of slightly
1014	  increased overhead in some places. If unsure say N here.
1015
1016config SCHED_MC_PRIO
1017	bool "CPU core priorities scheduler support"
1018	depends on SCHED_MC && CPU_SUP_INTEL
1019	select X86_INTEL_PSTATE
1020	select CPU_FREQ
1021	default y
1022	---help---
1023	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1024	  core ordering determined at manufacturing time, which allows
1025	  certain cores to reach higher turbo frequencies (when running
1026	  single threaded workloads) than others.
1027
1028	  Enabling this kernel feature teaches the scheduler about
1029	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1030	  scheduler's CPU selection logic accordingly, so that higher
1031	  overall system performance can be achieved.
1032
1033	  This feature will have no effect on CPUs without this feature.
1034
1035	  If unsure say Y here.
1036
1037source "kernel/Kconfig.preempt"
1038
1039config UP_LATE_INIT
1040       def_bool y
1041       depends on !SMP && X86_LOCAL_APIC
1042
1043config X86_UP_APIC
1044	bool "Local APIC support on uniprocessors" if !PCI_MSI
1045	default PCI_MSI
1046	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1047	---help---
1048	  A local APIC (Advanced Programmable Interrupt Controller) is an
1049	  integrated interrupt controller in the CPU. If you have a single-CPU
1050	  system which has a processor with a local APIC, you can say Y here to
1051	  enable and use it. If you say Y here even though your machine doesn't
1052	  have a local APIC, then the kernel will still run with no slowdown at
1053	  all. The local APIC supports CPU-generated self-interrupts (timer,
1054	  performance counters), and the NMI watchdog which detects hard
1055	  lockups.
1056
1057config X86_UP_IOAPIC
1058	bool "IO-APIC support on uniprocessors"
1059	depends on X86_UP_APIC
1060	---help---
1061	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1062	  SMP-capable replacement for PC-style interrupt controllers. Most
1063	  SMP systems and many recent uniprocessor systems have one.
1064
1065	  If you have a single-CPU system with an IO-APIC, you can say Y here
1066	  to use it. If you say Y here even though your machine doesn't have
1067	  an IO-APIC, then the kernel will still run with no slowdown at all.
1068
1069config X86_LOCAL_APIC
1070	def_bool y
1071	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1072	select IRQ_DOMAIN_HIERARCHY
1073	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1074
1075config X86_IO_APIC
1076	def_bool y
1077	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1078
1079config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1080	bool "Reroute for broken boot IRQs"
1081	depends on X86_IO_APIC
1082	---help---
1083	  This option enables a workaround that fixes a source of
1084	  spurious interrupts. This is recommended when threaded
1085	  interrupt handling is used on systems where the generation of
1086	  superfluous "boot interrupts" cannot be disabled.
1087
1088	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1089	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1090	  kernel does during interrupt handling). On chipsets where this
1091	  boot IRQ generation cannot be disabled, this workaround keeps
1092	  the original IRQ line masked so that only the equivalent "boot
1093	  IRQ" is delivered to the CPUs. The workaround also tells the
1094	  kernel to set up the IRQ handler on the boot IRQ line. In this
1095	  way only one interrupt is delivered to the kernel. Otherwise
1096	  the spurious second interrupt may cause the kernel to bring
1097	  down (vital) interrupt lines.
1098
1099	  Only affects "broken" chipsets. Interrupt sharing may be
1100	  increased on these systems.
1101
1102config X86_MCE
1103	bool "Machine Check / overheating reporting"
1104	select GENERIC_ALLOCATOR
1105	default y
1106	---help---
1107	  Machine Check support allows the processor to notify the
1108	  kernel if it detects a problem (e.g. overheating, data corruption).
1109	  The action the kernel takes depends on the severity of the problem,
1110	  ranging from warning messages to halting the machine.
1111
1112config X86_MCELOG_LEGACY
1113	bool "Support for deprecated /dev/mcelog character device"
1114	depends on X86_MCE
1115	---help---
1116	  Enable support for /dev/mcelog which is needed by the old mcelog
1117	  userspace logging daemon. Consider switching to the new generation
1118	  rasdaemon solution.
1119
1120config X86_MCE_INTEL
1121	def_bool y
1122	prompt "Intel MCE features"
1123	depends on X86_MCE && X86_LOCAL_APIC
1124	---help---
1125	   Additional support for intel specific MCE features such as
1126	   the thermal monitor.
1127
1128config X86_MCE_AMD
1129	def_bool y
1130	prompt "AMD MCE features"
1131	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1132	---help---
1133	   Additional support for AMD specific MCE features such as
1134	   the DRAM Error Threshold.
1135
1136config X86_ANCIENT_MCE
1137	bool "Support for old Pentium 5 / WinChip machine checks"
1138	depends on X86_32 && X86_MCE
1139	---help---
1140	  Include support for machine check handling on old Pentium 5 or WinChip
1141	  systems. These typically need to be enabled explicitly on the command
1142	  line.
1143
1144config X86_MCE_THRESHOLD
1145	depends on X86_MCE_AMD || X86_MCE_INTEL
1146	def_bool y
1147
1148config X86_MCE_INJECT
1149	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1150	tristate "Machine check injector support"
1151	---help---
1152	  Provide support for injecting machine checks for testing purposes.
1153	  If you don't know what a machine check is and you don't do kernel
1154	  QA it is safe to say n.
1155
1156config X86_THERMAL_VECTOR
1157	def_bool y
1158	depends on X86_MCE_INTEL
1159
1160source "arch/x86/events/Kconfig"
1161
1162config X86_LEGACY_VM86
1163	bool "Legacy VM86 support"
1164	default n
1165	depends on X86_32
1166	---help---
1167	  This option allows user programs to put the CPU into V8086
1168	  mode, which is an 80286-era approximation of 16-bit real mode.
1169
1170	  Some very old versions of X and/or vbetool require this option
1171	  for user mode setting.  Similarly, DOSEMU will use it if
1172	  available to accelerate real mode DOS programs.  However, any
1173	  recent version of DOSEMU, X, or vbetool should be fully
1174	  functional even without kernel VM86 support, as they will all
1175	  fall back to software emulation. Nevertheless, if you are using
1176	  a 16-bit DOS program where 16-bit performance matters, vm86
1177	  mode might be faster than emulation and you might want to
1178	  enable this option.
1179
1180	  Note that any app that works on a 64-bit kernel is unlikely to
1181	  need this option, as 64-bit kernels don't, and can't, support
1182	  V8086 mode. This option is also unrelated to 16-bit protected
1183	  mode and is not needed to run most 16-bit programs under Wine.
1184
1185	  Enabling this option increases the complexity of the kernel
1186	  and slows down exception handling a tiny bit.
1187
1188	  If unsure, say N here.
1189
1190config VM86
1191       bool
1192       default X86_LEGACY_VM86
1193
1194config X86_16BIT
1195	bool "Enable support for 16-bit segments" if EXPERT
1196	default y
1197	depends on MODIFY_LDT_SYSCALL
1198	---help---
1199	  This option is required by programs like Wine to run 16-bit
1200	  protected mode legacy code on x86 processors.  Disabling
1201	  this option saves about 300 bytes on i386, or around 6K text
1202	  plus 16K runtime memory on x86-64,
1203
1204config X86_ESPFIX32
1205	def_bool y
1206	depends on X86_16BIT && X86_32
1207
1208config X86_ESPFIX64
1209	def_bool y
1210	depends on X86_16BIT && X86_64
1211
1212config X86_VSYSCALL_EMULATION
1213       bool "Enable vsyscall emulation" if EXPERT
1214       default y
1215       depends on X86_64
1216       ---help---
1217	 This enables emulation of the legacy vsyscall page.  Disabling
1218	 it is roughly equivalent to booting with vsyscall=none, except
1219	 that it will also disable the helpful warning if a program
1220	 tries to use a vsyscall.  With this option set to N, offending
1221	 programs will just segfault, citing addresses of the form
1222	 0xffffffffff600?00.
1223
1224	 This option is required by many programs built before 2013, and
1225	 care should be used even with newer programs if set to N.
1226
1227	 Disabling this option saves about 7K of kernel size and
1228	 possibly 4K of additional runtime pagetable memory.
1229
1230config TOSHIBA
1231	tristate "Toshiba Laptop support"
1232	depends on X86_32
1233	---help---
1234	  This adds a driver to safely access the System Management Mode of
1235	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1236	  not work on models with a Phoenix BIOS. The System Management Mode
1237	  is used to set the BIOS and power saving options on Toshiba portables.
1238
1239	  For information on utilities to make use of this driver see the
1240	  Toshiba Linux utilities web site at:
1241	  <http://www.buzzard.org.uk/toshiba/>.
1242
1243	  Say Y if you intend to run this kernel on a Toshiba portable.
1244	  Say N otherwise.
1245
1246config I8K
1247	tristate "Dell i8k legacy laptop support"
1248	select HWMON
1249	select SENSORS_DELL_SMM
1250	---help---
1251	  This option enables legacy /proc/i8k userspace interface in hwmon
1252	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1253	  temperature and allows controlling fan speeds of Dell laptops via
1254	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1255	  it reports also power and hotkey status. For fan speed control is
1256	  needed userspace package i8kutils.
1257
1258	  Say Y if you intend to run this kernel on old Dell laptops or want to
1259	  use userspace package i8kutils.
1260	  Say N otherwise.
1261
1262config X86_REBOOTFIXUPS
1263	bool "Enable X86 board specific fixups for reboot"
1264	depends on X86_32
1265	---help---
1266	  This enables chipset and/or board specific fixups to be done
1267	  in order to get reboot to work correctly. This is only needed on
1268	  some combinations of hardware and BIOS. The symptom, for which
1269	  this config is intended, is when reboot ends with a stalled/hung
1270	  system.
1271
1272	  Currently, the only fixup is for the Geode machines using
1273	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1274
1275	  Say Y if you want to enable the fixup. Currently, it's safe to
1276	  enable this option even if you don't need it.
1277	  Say N otherwise.
1278
1279config MICROCODE
1280	bool "CPU microcode loading support"
1281	default y
1282	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1283	select FW_LOADER
1284	---help---
1285	  If you say Y here, you will be able to update the microcode on
1286	  Intel and AMD processors. The Intel support is for the IA32 family,
1287	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1288	  AMD support is for families 0x10 and later. You will obviously need
1289	  the actual microcode binary data itself which is not shipped with
1290	  the Linux kernel.
1291
1292	  The preferred method to load microcode from a detached initrd is described
1293	  in Documentation/x86/microcode.txt. For that you need to enable
1294	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1295	  initrd for microcode blobs.
1296
1297	  In addition, you can build the microcode into the kernel. For that you
1298	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1299	  config option.
1300
1301config MICROCODE_INTEL
1302	bool "Intel microcode loading support"
1303	depends on MICROCODE
1304	default MICROCODE
1305	select FW_LOADER
1306	---help---
1307	  This options enables microcode patch loading support for Intel
1308	  processors.
1309
1310	  For the current Intel microcode data package go to
1311	  <https://downloadcenter.intel.com> and search for
1312	  'Linux Processor Microcode Data File'.
1313
1314config MICROCODE_AMD
1315	bool "AMD microcode loading support"
1316	depends on MICROCODE
1317	select FW_LOADER
1318	---help---
1319	  If you select this option, microcode patch loading support for AMD
1320	  processors will be enabled.
1321
1322config MICROCODE_OLD_INTERFACE
1323	def_bool y
1324	depends on MICROCODE
1325
1326config X86_MSR
1327	tristate "/dev/cpu/*/msr - Model-specific register support"
1328	---help---
1329	  This device gives privileged processes access to the x86
1330	  Model-Specific Registers (MSRs).  It is a character device with
1331	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1332	  MSR accesses are directed to a specific CPU on multi-processor
1333	  systems.
1334
1335config X86_CPUID
1336	tristate "/dev/cpu/*/cpuid - CPU information support"
1337	---help---
1338	  This device gives processes access to the x86 CPUID instruction to
1339	  be executed on a specific processor.  It is a character device
1340	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1341	  /dev/cpu/31/cpuid.
1342
1343choice
1344	prompt "High Memory Support"
1345	default HIGHMEM4G
1346	depends on X86_32
1347
1348config NOHIGHMEM
1349	bool "off"
1350	---help---
1351	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1352	  However, the address space of 32-bit x86 processors is only 4
1353	  Gigabytes large. That means that, if you have a large amount of
1354	  physical memory, not all of it can be "permanently mapped" by the
1355	  kernel. The physical memory that's not permanently mapped is called
1356	  "high memory".
1357
1358	  If you are compiling a kernel which will never run on a machine with
1359	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1360	  choice and suitable for most users). This will result in a "3GB/1GB"
1361	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1362	  space and the remaining part of the 4GB virtual memory space is used
1363	  by the kernel to permanently map as much physical memory as
1364	  possible.
1365
1366	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1367	  answer "4GB" here.
1368
1369	  If more than 4 Gigabytes is used then answer "64GB" here. This
1370	  selection turns Intel PAE (Physical Address Extension) mode on.
1371	  PAE implements 3-level paging on IA32 processors. PAE is fully
1372	  supported by Linux, PAE mode is implemented on all recent Intel
1373	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1374	  then the kernel will not boot on CPUs that don't support PAE!
1375
1376	  The actual amount of total physical memory will either be
1377	  auto detected or can be forced by using a kernel command line option
1378	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1379	  your boot loader (lilo or loadlin) about how to pass options to the
1380	  kernel at boot time.)
1381
1382	  If unsure, say "off".
1383
1384config HIGHMEM4G
1385	bool "4GB"
1386	---help---
1387	  Select this if you have a 32-bit processor and between 1 and 4
1388	  gigabytes of physical RAM.
1389
1390config HIGHMEM64G
1391	bool "64GB"
1392	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1393	select X86_PAE
1394	---help---
1395	  Select this if you have a 32-bit processor and more than 4
1396	  gigabytes of physical RAM.
1397
1398endchoice
1399
1400choice
1401	prompt "Memory split" if EXPERT
1402	default VMSPLIT_3G
1403	depends on X86_32
1404	---help---
1405	  Select the desired split between kernel and user memory.
1406
1407	  If the address range available to the kernel is less than the
1408	  physical memory installed, the remaining memory will be available
1409	  as "high memory". Accessing high memory is a little more costly
1410	  than low memory, as it needs to be mapped into the kernel first.
1411	  Note that increasing the kernel address space limits the range
1412	  available to user programs, making the address space there
1413	  tighter.  Selecting anything other than the default 3G/1G split
1414	  will also likely make your kernel incompatible with binary-only
1415	  kernel modules.
1416
1417	  If you are not absolutely sure what you are doing, leave this
1418	  option alone!
1419
1420	config VMSPLIT_3G
1421		bool "3G/1G user/kernel split"
1422	config VMSPLIT_3G_OPT
1423		depends on !X86_PAE
1424		bool "3G/1G user/kernel split (for full 1G low memory)"
1425	config VMSPLIT_2G
1426		bool "2G/2G user/kernel split"
1427	config VMSPLIT_2G_OPT
1428		depends on !X86_PAE
1429		bool "2G/2G user/kernel split (for full 2G low memory)"
1430	config VMSPLIT_1G
1431		bool "1G/3G user/kernel split"
1432endchoice
1433
1434config PAGE_OFFSET
1435	hex
1436	default 0xB0000000 if VMSPLIT_3G_OPT
1437	default 0x80000000 if VMSPLIT_2G
1438	default 0x78000000 if VMSPLIT_2G_OPT
1439	default 0x40000000 if VMSPLIT_1G
1440	default 0xC0000000
1441	depends on X86_32
1442
1443config HIGHMEM
1444	def_bool y
1445	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1446
1447config X86_PAE
1448	bool "PAE (Physical Address Extension) Support"
1449	depends on X86_32 && !HIGHMEM4G
1450	select PHYS_ADDR_T_64BIT
1451	select SWIOTLB
1452	---help---
1453	  PAE is required for NX support, and furthermore enables
1454	  larger swapspace support for non-overcommit purposes. It
1455	  has the cost of more pagetable lookup overhead, and also
1456	  consumes more pagetable space per process.
1457
1458config X86_5LEVEL
1459	bool "Enable 5-level page tables support"
1460	select DYNAMIC_MEMORY_LAYOUT
1461	select SPARSEMEM_VMEMMAP
1462	depends on X86_64
1463	---help---
1464	  5-level paging enables access to larger address space:
1465	  upto 128 PiB of virtual address space and 4 PiB of
1466	  physical address space.
1467
1468	  It will be supported by future Intel CPUs.
1469
1470	  A kernel with the option enabled can be booted on machines that
1471	  support 4- or 5-level paging.
1472
1473	  See Documentation/x86/x86_64/5level-paging.txt for more
1474	  information.
1475
1476	  Say N if unsure.
1477
1478config X86_DIRECT_GBPAGES
1479	def_bool y
1480	depends on X86_64 && !DEBUG_PAGEALLOC
1481	---help---
1482	  Certain kernel features effectively disable kernel
1483	  linear 1 GB mappings (even if the CPU otherwise
1484	  supports them), so don't confuse the user by printing
1485	  that we have them enabled.
1486
1487config ARCH_HAS_MEM_ENCRYPT
1488	def_bool y
1489
1490config AMD_MEM_ENCRYPT
1491	bool "AMD Secure Memory Encryption (SME) support"
1492	depends on X86_64 && CPU_SUP_AMD
1493	select DYNAMIC_PHYSICAL_MASK
1494	---help---
1495	  Say yes to enable support for the encryption of system memory.
1496	  This requires an AMD processor that supports Secure Memory
1497	  Encryption (SME).
1498
1499config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1500	bool "Activate AMD Secure Memory Encryption (SME) by default"
1501	default y
1502	depends on AMD_MEM_ENCRYPT
1503	---help---
1504	  Say yes to have system memory encrypted by default if running on
1505	  an AMD processor that supports Secure Memory Encryption (SME).
1506
1507	  If set to Y, then the encryption of system memory can be
1508	  deactivated with the mem_encrypt=off command line option.
1509
1510	  If set to N, then the encryption of system memory can be
1511	  activated with the mem_encrypt=on command line option.
1512
1513config ARCH_USE_MEMREMAP_PROT
1514	def_bool y
1515	depends on AMD_MEM_ENCRYPT
1516
1517# Common NUMA Features
1518config NUMA
1519	bool "Numa Memory Allocation and Scheduler Support"
1520	depends on SMP
1521	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1522	default y if X86_BIGSMP
1523	---help---
1524	  Enable NUMA (Non Uniform Memory Access) support.
1525
1526	  The kernel will try to allocate memory used by a CPU on the
1527	  local memory controller of the CPU and add some more
1528	  NUMA awareness to the kernel.
1529
1530	  For 64-bit this is recommended if the system is Intel Core i7
1531	  (or later), AMD Opteron, or EM64T NUMA.
1532
1533	  For 32-bit this is only needed if you boot a 32-bit
1534	  kernel on a 64-bit NUMA platform.
1535
1536	  Otherwise, you should say N.
1537
1538config AMD_NUMA
1539	def_bool y
1540	prompt "Old style AMD Opteron NUMA detection"
1541	depends on X86_64 && NUMA && PCI
1542	---help---
1543	  Enable AMD NUMA node topology detection.  You should say Y here if
1544	  you have a multi processor AMD system. This uses an old method to
1545	  read the NUMA configuration directly from the builtin Northbridge
1546	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1547	  which also takes priority if both are compiled in.
1548
1549config X86_64_ACPI_NUMA
1550	def_bool y
1551	prompt "ACPI NUMA detection"
1552	depends on X86_64 && NUMA && ACPI && PCI
1553	select ACPI_NUMA
1554	---help---
1555	  Enable ACPI SRAT based node topology detection.
1556
1557# Some NUMA nodes have memory ranges that span
1558# other nodes.  Even though a pfn is valid and
1559# between a node's start and end pfns, it may not
1560# reside on that node.  See memmap_init_zone()
1561# for details.
1562config NODES_SPAN_OTHER_NODES
1563	def_bool y
1564	depends on X86_64_ACPI_NUMA
1565
1566config NUMA_EMU
1567	bool "NUMA emulation"
1568	depends on NUMA
1569	---help---
1570	  Enable NUMA emulation. A flat machine will be split
1571	  into virtual nodes when booted with "numa=fake=N", where N is the
1572	  number of nodes. This is only useful for debugging.
1573
1574config NODES_SHIFT
1575	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1576	range 1 10
1577	default "10" if MAXSMP
1578	default "6" if X86_64
1579	default "3"
1580	depends on NEED_MULTIPLE_NODES
1581	---help---
1582	  Specify the maximum number of NUMA Nodes available on the target
1583	  system.  Increases memory reserved to accommodate various tables.
1584
1585config ARCH_HAVE_MEMORY_PRESENT
1586	def_bool y
1587	depends on X86_32 && DISCONTIGMEM
1588
1589config ARCH_FLATMEM_ENABLE
1590	def_bool y
1591	depends on X86_32 && !NUMA
1592
1593config ARCH_DISCONTIGMEM_ENABLE
1594	def_bool y
1595	depends on NUMA && X86_32
1596
1597config ARCH_DISCONTIGMEM_DEFAULT
1598	def_bool y
1599	depends on NUMA && X86_32
1600
1601config ARCH_SPARSEMEM_ENABLE
1602	def_bool y
1603	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1604	select SPARSEMEM_STATIC if X86_32
1605	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1606
1607config ARCH_SPARSEMEM_DEFAULT
1608	def_bool y
1609	depends on X86_64
1610
1611config ARCH_SELECT_MEMORY_MODEL
1612	def_bool y
1613	depends on ARCH_SPARSEMEM_ENABLE
1614
1615config ARCH_MEMORY_PROBE
1616	bool "Enable sysfs memory/probe interface"
1617	depends on X86_64 && MEMORY_HOTPLUG
1618	help
1619	  This option enables a sysfs memory/probe interface for testing.
1620	  See Documentation/memory-hotplug.txt for more information.
1621	  If you are unsure how to answer this question, answer N.
1622
1623config ARCH_PROC_KCORE_TEXT
1624	def_bool y
1625	depends on X86_64 && PROC_KCORE
1626
1627config ILLEGAL_POINTER_VALUE
1628       hex
1629       default 0 if X86_32
1630       default 0xdead000000000000 if X86_64
1631
1632source "mm/Kconfig"
1633
1634config X86_PMEM_LEGACY_DEVICE
1635	bool
1636
1637config X86_PMEM_LEGACY
1638	tristate "Support non-standard NVDIMMs and ADR protected memory"
1639	depends on PHYS_ADDR_T_64BIT
1640	depends on BLK_DEV
1641	select X86_PMEM_LEGACY_DEVICE
1642	select LIBNVDIMM
1643	help
1644	  Treat memory marked using the non-standard e820 type of 12 as used
1645	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1646	  The kernel will offer these regions to the 'pmem' driver so
1647	  they can be used for persistent storage.
1648
1649	  Say Y if unsure.
1650
1651config HIGHPTE
1652	bool "Allocate 3rd-level pagetables from highmem"
1653	depends on HIGHMEM
1654	---help---
1655	  The VM uses one page table entry for each page of physical memory.
1656	  For systems with a lot of RAM, this can be wasteful of precious
1657	  low memory.  Setting this option will put user-space page table
1658	  entries in high memory.
1659
1660config X86_CHECK_BIOS_CORRUPTION
1661	bool "Check for low memory corruption"
1662	---help---
1663	  Periodically check for memory corruption in low memory, which
1664	  is suspected to be caused by BIOS.  Even when enabled in the
1665	  configuration, it is disabled at runtime.  Enable it by
1666	  setting "memory_corruption_check=1" on the kernel command
1667	  line.  By default it scans the low 64k of memory every 60
1668	  seconds; see the memory_corruption_check_size and
1669	  memory_corruption_check_period parameters in
1670	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1671
1672	  When enabled with the default parameters, this option has
1673	  almost no overhead, as it reserves a relatively small amount
1674	  of memory and scans it infrequently.  It both detects corruption
1675	  and prevents it from affecting the running system.
1676
1677	  It is, however, intended as a diagnostic tool; if repeatable
1678	  BIOS-originated corruption always affects the same memory,
1679	  you can use memmap= to prevent the kernel from using that
1680	  memory.
1681
1682config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1683	bool "Set the default setting of memory_corruption_check"
1684	depends on X86_CHECK_BIOS_CORRUPTION
1685	default y
1686	---help---
1687	  Set whether the default state of memory_corruption_check is
1688	  on or off.
1689
1690config X86_RESERVE_LOW
1691	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1692	default 64
1693	range 4 640
1694	---help---
1695	  Specify the amount of low memory to reserve for the BIOS.
1696
1697	  The first page contains BIOS data structures that the kernel
1698	  must not use, so that page must always be reserved.
1699
1700	  By default we reserve the first 64K of physical RAM, as a
1701	  number of BIOSes are known to corrupt that memory range
1702	  during events such as suspend/resume or monitor cable
1703	  insertion, so it must not be used by the kernel.
1704
1705	  You can set this to 4 if you are absolutely sure that you
1706	  trust the BIOS to get all its memory reservations and usages
1707	  right.  If you know your BIOS have problems beyond the
1708	  default 64K area, you can set this to 640 to avoid using the
1709	  entire low memory range.
1710
1711	  If you have doubts about the BIOS (e.g. suspend/resume does
1712	  not work or there's kernel crashes after certain hardware
1713	  hotplug events) then you might want to enable
1714	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1715	  typical corruption patterns.
1716
1717	  Leave this to the default value of 64 if you are unsure.
1718
1719config MATH_EMULATION
1720	bool
1721	depends on MODIFY_LDT_SYSCALL
1722	prompt "Math emulation" if X86_32
1723	---help---
1724	  Linux can emulate a math coprocessor (used for floating point
1725	  operations) if you don't have one. 486DX and Pentium processors have
1726	  a math coprocessor built in, 486SX and 386 do not, unless you added
1727	  a 487DX or 387, respectively. (The messages during boot time can
1728	  give you some hints here ["man dmesg"].) Everyone needs either a
1729	  coprocessor or this emulation.
1730
1731	  If you don't have a math coprocessor, you need to say Y here; if you
1732	  say Y here even though you have a coprocessor, the coprocessor will
1733	  be used nevertheless. (This behavior can be changed with the kernel
1734	  command line option "no387", which comes handy if your coprocessor
1735	  is broken. Try "man bootparam" or see the documentation of your boot
1736	  loader (lilo or loadlin) about how to pass options to the kernel at
1737	  boot time.) This means that it is a good idea to say Y here if you
1738	  intend to use this kernel on different machines.
1739
1740	  More information about the internals of the Linux math coprocessor
1741	  emulation can be found in <file:arch/x86/math-emu/README>.
1742
1743	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1744	  kernel, it won't hurt.
1745
1746config MTRR
1747	def_bool y
1748	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1749	---help---
1750	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1751	  the Memory Type Range Registers (MTRRs) may be used to control
1752	  processor access to memory ranges. This is most useful if you have
1753	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1754	  allows bus write transfers to be combined into a larger transfer
1755	  before bursting over the PCI/AGP bus. This can increase performance
1756	  of image write operations 2.5 times or more. Saying Y here creates a
1757	  /proc/mtrr file which may be used to manipulate your processor's
1758	  MTRRs. Typically the X server should use this.
1759
1760	  This code has a reasonably generic interface so that similar
1761	  control registers on other processors can be easily supported
1762	  as well:
1763
1764	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1765	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1766	  these, the ARRs are used to emulate the MTRRs.
1767	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1768	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1769	  write-combining. All of these processors are supported by this code
1770	  and it makes sense to say Y here if you have one of them.
1771
1772	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1773	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1774	  can lead to all sorts of problems, so it's good to say Y here.
1775
1776	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1777	  just add about 9 KB to your kernel.
1778
1779	  See <file:Documentation/x86/mtrr.txt> for more information.
1780
1781config MTRR_SANITIZER
1782	def_bool y
1783	prompt "MTRR cleanup support"
1784	depends on MTRR
1785	---help---
1786	  Convert MTRR layout from continuous to discrete, so X drivers can
1787	  add writeback entries.
1788
1789	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1790	  The largest mtrr entry size for a continuous block can be set with
1791	  mtrr_chunk_size.
1792
1793	  If unsure, say Y.
1794
1795config MTRR_SANITIZER_ENABLE_DEFAULT
1796	int "MTRR cleanup enable value (0-1)"
1797	range 0 1
1798	default "0"
1799	depends on MTRR_SANITIZER
1800	---help---
1801	  Enable mtrr cleanup default value
1802
1803config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1804	int "MTRR cleanup spare reg num (0-7)"
1805	range 0 7
1806	default "1"
1807	depends on MTRR_SANITIZER
1808	---help---
1809	  mtrr cleanup spare entries default, it can be changed via
1810	  mtrr_spare_reg_nr=N on the kernel command line.
1811
1812config X86_PAT
1813	def_bool y
1814	prompt "x86 PAT support" if EXPERT
1815	depends on MTRR
1816	---help---
1817	  Use PAT attributes to setup page level cache control.
1818
1819	  PATs are the modern equivalents of MTRRs and are much more
1820	  flexible than MTRRs.
1821
1822	  Say N here if you see bootup problems (boot crash, boot hang,
1823	  spontaneous reboots) or a non-working video driver.
1824
1825	  If unsure, say Y.
1826
1827config ARCH_USES_PG_UNCACHED
1828	def_bool y
1829	depends on X86_PAT
1830
1831config ARCH_RANDOM
1832	def_bool y
1833	prompt "x86 architectural random number generator" if EXPERT
1834	---help---
1835	  Enable the x86 architectural RDRAND instruction
1836	  (Intel Bull Mountain technology) to generate random numbers.
1837	  If supported, this is a high bandwidth, cryptographically
1838	  secure hardware random number generator.
1839
1840config X86_SMAP
1841	def_bool y
1842	prompt "Supervisor Mode Access Prevention" if EXPERT
1843	---help---
1844	  Supervisor Mode Access Prevention (SMAP) is a security
1845	  feature in newer Intel processors.  There is a small
1846	  performance cost if this enabled and turned on; there is
1847	  also a small increase in the kernel size if this is enabled.
1848
1849	  If unsure, say Y.
1850
1851config X86_INTEL_UMIP
1852	def_bool y
1853	depends on CPU_SUP_INTEL
1854	prompt "Intel User Mode Instruction Prevention" if EXPERT
1855	---help---
1856	  The User Mode Instruction Prevention (UMIP) is a security
1857	  feature in newer Intel processors. If enabled, a general
1858	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1859	  or STR instructions are executed in user mode. These instructions
1860	  unnecessarily expose information about the hardware state.
1861
1862	  The vast majority of applications do not use these instructions.
1863	  For the very few that do, software emulation is provided in
1864	  specific cases in protected and virtual-8086 modes. Emulated
1865	  results are dummy.
1866
1867config X86_INTEL_MPX
1868	prompt "Intel MPX (Memory Protection Extensions)"
1869	def_bool n
1870	# Note: only available in 64-bit mode due to VMA flags shortage
1871	depends on CPU_SUP_INTEL && X86_64
1872	select ARCH_USES_HIGH_VMA_FLAGS
1873	---help---
1874	  MPX provides hardware features that can be used in
1875	  conjunction with compiler-instrumented code to check
1876	  memory references.  It is designed to detect buffer
1877	  overflow or underflow bugs.
1878
1879	  This option enables running applications which are
1880	  instrumented or otherwise use MPX.  It does not use MPX
1881	  itself inside the kernel or to protect the kernel
1882	  against bad memory references.
1883
1884	  Enabling this option will make the kernel larger:
1885	  ~8k of kernel text and 36 bytes of data on a 64-bit
1886	  defconfig.  It adds a long to the 'mm_struct' which
1887	  will increase the kernel memory overhead of each
1888	  process and adds some branches to paths used during
1889	  exec() and munmap().
1890
1891	  For details, see Documentation/x86/intel_mpx.txt
1892
1893	  If unsure, say N.
1894
1895config X86_INTEL_MEMORY_PROTECTION_KEYS
1896	prompt "Intel Memory Protection Keys"
1897	def_bool y
1898	# Note: only available in 64-bit mode
1899	depends on CPU_SUP_INTEL && X86_64
1900	select ARCH_USES_HIGH_VMA_FLAGS
1901	select ARCH_HAS_PKEYS
1902	---help---
1903	  Memory Protection Keys provides a mechanism for enforcing
1904	  page-based protections, but without requiring modification of the
1905	  page tables when an application changes protection domains.
1906
1907	  For details, see Documentation/x86/protection-keys.txt
1908
1909	  If unsure, say y.
1910
1911config EFI
1912	bool "EFI runtime service support"
1913	depends on ACPI
1914	select UCS2_STRING
1915	select EFI_RUNTIME_WRAPPERS
1916	---help---
1917	  This enables the kernel to use EFI runtime services that are
1918	  available (such as the EFI variable services).
1919
1920	  This option is only useful on systems that have EFI firmware.
1921	  In addition, you should use the latest ELILO loader available
1922	  at <http://elilo.sourceforge.net> in order to take advantage
1923	  of EFI runtime services. However, even with this option, the
1924	  resultant kernel should continue to boot on existing non-EFI
1925	  platforms.
1926
1927config EFI_STUB
1928       bool "EFI stub support"
1929       depends on EFI && !X86_USE_3DNOW
1930       select RELOCATABLE
1931       ---help---
1932          This kernel feature allows a bzImage to be loaded directly
1933	  by EFI firmware without the use of a bootloader.
1934
1935	  See Documentation/efi-stub.txt for more information.
1936
1937config EFI_MIXED
1938	bool "EFI mixed-mode support"
1939	depends on EFI_STUB && X86_64
1940	---help---
1941	   Enabling this feature allows a 64-bit kernel to be booted
1942	   on a 32-bit firmware, provided that your CPU supports 64-bit
1943	   mode.
1944
1945	   Note that it is not possible to boot a mixed-mode enabled
1946	   kernel via the EFI boot stub - a bootloader that supports
1947	   the EFI handover protocol must be used.
1948
1949	   If unsure, say N.
1950
1951config SECCOMP
1952	def_bool y
1953	prompt "Enable seccomp to safely compute untrusted bytecode"
1954	---help---
1955	  This kernel feature is useful for number crunching applications
1956	  that may need to compute untrusted bytecode during their
1957	  execution. By using pipes or other transports made available to
1958	  the process as file descriptors supporting the read/write
1959	  syscalls, it's possible to isolate those applications in
1960	  their own address space using seccomp. Once seccomp is
1961	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1962	  and the task is only allowed to execute a few safe syscalls
1963	  defined by each seccomp mode.
1964
1965	  If unsure, say Y. Only embedded should say N here.
1966
1967source kernel/Kconfig.hz
1968
1969config KEXEC
1970	bool "kexec system call"
1971	select KEXEC_CORE
1972	---help---
1973	  kexec is a system call that implements the ability to shutdown your
1974	  current kernel, and to start another kernel.  It is like a reboot
1975	  but it is independent of the system firmware.   And like a reboot
1976	  you can start any kernel with it, not just Linux.
1977
1978	  The name comes from the similarity to the exec system call.
1979
1980	  It is an ongoing process to be certain the hardware in a machine
1981	  is properly shutdown, so do not be surprised if this code does not
1982	  initially work for you.  As of this writing the exact hardware
1983	  interface is strongly in flux, so no good recommendation can be
1984	  made.
1985
1986config KEXEC_FILE
1987	bool "kexec file based system call"
1988	select KEXEC_CORE
1989	select BUILD_BIN2C
1990	depends on X86_64
1991	depends on CRYPTO=y
1992	depends on CRYPTO_SHA256=y
1993	---help---
1994	  This is new version of kexec system call. This system call is
1995	  file based and takes file descriptors as system call argument
1996	  for kernel and initramfs as opposed to list of segments as
1997	  accepted by previous system call.
1998
1999config ARCH_HAS_KEXEC_PURGATORY
2000	def_bool KEXEC_FILE
2001
2002config KEXEC_VERIFY_SIG
2003	bool "Verify kernel signature during kexec_file_load() syscall"
2004	depends on KEXEC_FILE
2005	---help---
2006	  This option makes kernel signature verification mandatory for
2007	  the kexec_file_load() syscall.
2008
2009	  In addition to that option, you need to enable signature
2010	  verification for the corresponding kernel image type being
2011	  loaded in order for this to work.
2012
2013config KEXEC_BZIMAGE_VERIFY_SIG
2014	bool "Enable bzImage signature verification support"
2015	depends on KEXEC_VERIFY_SIG
2016	depends on SIGNED_PE_FILE_VERIFICATION
2017	select SYSTEM_TRUSTED_KEYRING
2018	---help---
2019	  Enable bzImage signature verification support.
2020
2021config CRASH_DUMP
2022	bool "kernel crash dumps"
2023	depends on X86_64 || (X86_32 && HIGHMEM)
2024	---help---
2025	  Generate crash dump after being started by kexec.
2026	  This should be normally only set in special crash dump kernels
2027	  which are loaded in the main kernel with kexec-tools into
2028	  a specially reserved region and then later executed after
2029	  a crash by kdump/kexec. The crash dump kernel must be compiled
2030	  to a memory address not used by the main kernel or BIOS using
2031	  PHYSICAL_START, or it must be built as a relocatable image
2032	  (CONFIG_RELOCATABLE=y).
2033	  For more details see Documentation/kdump/kdump.txt
2034
2035config KEXEC_JUMP
2036	bool "kexec jump"
2037	depends on KEXEC && HIBERNATION
2038	---help---
2039	  Jump between original kernel and kexeced kernel and invoke
2040	  code in physical address mode via KEXEC
2041
2042config PHYSICAL_START
2043	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2044	default "0x1000000"
2045	---help---
2046	  This gives the physical address where the kernel is loaded.
2047
2048	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2049	  bzImage will decompress itself to above physical address and
2050	  run from there. Otherwise, bzImage will run from the address where
2051	  it has been loaded by the boot loader and will ignore above physical
2052	  address.
2053
2054	  In normal kdump cases one does not have to set/change this option
2055	  as now bzImage can be compiled as a completely relocatable image
2056	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2057	  address. This option is mainly useful for the folks who don't want
2058	  to use a bzImage for capturing the crash dump and want to use a
2059	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2060	  to be specifically compiled to run from a specific memory area
2061	  (normally a reserved region) and this option comes handy.
2062
2063	  So if you are using bzImage for capturing the crash dump,
2064	  leave the value here unchanged to 0x1000000 and set
2065	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2066	  for capturing the crash dump change this value to start of
2067	  the reserved region.  In other words, it can be set based on
2068	  the "X" value as specified in the "crashkernel=YM@XM"
2069	  command line boot parameter passed to the panic-ed
2070	  kernel. Please take a look at Documentation/kdump/kdump.txt
2071	  for more details about crash dumps.
2072
2073	  Usage of bzImage for capturing the crash dump is recommended as
2074	  one does not have to build two kernels. Same kernel can be used
2075	  as production kernel and capture kernel. Above option should have
2076	  gone away after relocatable bzImage support is introduced. But it
2077	  is present because there are users out there who continue to use
2078	  vmlinux for dump capture. This option should go away down the
2079	  line.
2080
2081	  Don't change this unless you know what you are doing.
2082
2083config RELOCATABLE
2084	bool "Build a relocatable kernel"
2085	default y
2086	---help---
2087	  This builds a kernel image that retains relocation information
2088	  so it can be loaded someplace besides the default 1MB.
2089	  The relocations tend to make the kernel binary about 10% larger,
2090	  but are discarded at runtime.
2091
2092	  One use is for the kexec on panic case where the recovery kernel
2093	  must live at a different physical address than the primary
2094	  kernel.
2095
2096	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2097	  it has been loaded at and the compile time physical address
2098	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2099
2100config RANDOMIZE_BASE
2101	bool "Randomize the address of the kernel image (KASLR)"
2102	depends on RELOCATABLE
2103	default y
2104	---help---
2105	  In support of Kernel Address Space Layout Randomization (KASLR),
2106	  this randomizes the physical address at which the kernel image
2107	  is decompressed and the virtual address where the kernel
2108	  image is mapped, as a security feature that deters exploit
2109	  attempts relying on knowledge of the location of kernel
2110	  code internals.
2111
2112	  On 64-bit, the kernel physical and virtual addresses are
2113	  randomized separately. The physical address will be anywhere
2114	  between 16MB and the top of physical memory (up to 64TB). The
2115	  virtual address will be randomized from 16MB up to 1GB (9 bits
2116	  of entropy). Note that this also reduces the memory space
2117	  available to kernel modules from 1.5GB to 1GB.
2118
2119	  On 32-bit, the kernel physical and virtual addresses are
2120	  randomized together. They will be randomized from 16MB up to
2121	  512MB (8 bits of entropy).
2122
2123	  Entropy is generated using the RDRAND instruction if it is
2124	  supported. If RDTSC is supported, its value is mixed into
2125	  the entropy pool as well. If neither RDRAND nor RDTSC are
2126	  supported, then entropy is read from the i8254 timer. The
2127	  usable entropy is limited by the kernel being built using
2128	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2129	  minimum of 2MB. As a result, only 10 bits of entropy are
2130	  theoretically possible, but the implementations are further
2131	  limited due to memory layouts.
2132
2133	  If unsure, say Y.
2134
2135# Relocation on x86 needs some additional build support
2136config X86_NEED_RELOCS
2137	def_bool y
2138	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2139
2140config PHYSICAL_ALIGN
2141	hex "Alignment value to which kernel should be aligned"
2142	default "0x200000"
2143	range 0x2000 0x1000000 if X86_32
2144	range 0x200000 0x1000000 if X86_64
2145	---help---
2146	  This value puts the alignment restrictions on physical address
2147	  where kernel is loaded and run from. Kernel is compiled for an
2148	  address which meets above alignment restriction.
2149
2150	  If bootloader loads the kernel at a non-aligned address and
2151	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2152	  address aligned to above value and run from there.
2153
2154	  If bootloader loads the kernel at a non-aligned address and
2155	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2156	  load address and decompress itself to the address it has been
2157	  compiled for and run from there. The address for which kernel is
2158	  compiled already meets above alignment restrictions. Hence the
2159	  end result is that kernel runs from a physical address meeting
2160	  above alignment restrictions.
2161
2162	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2163	  this value must be a multiple of 0x200000.
2164
2165	  Don't change this unless you know what you are doing.
2166
2167config DYNAMIC_MEMORY_LAYOUT
2168	bool
2169	---help---
2170	  This option makes base addresses of vmalloc and vmemmap as well as
2171	  __PAGE_OFFSET movable during boot.
2172
2173config RANDOMIZE_MEMORY
2174	bool "Randomize the kernel memory sections"
2175	depends on X86_64
2176	depends on RANDOMIZE_BASE
2177	select DYNAMIC_MEMORY_LAYOUT
2178	default RANDOMIZE_BASE
2179	---help---
2180	   Randomizes the base virtual address of kernel memory sections
2181	   (physical memory mapping, vmalloc & vmemmap). This security feature
2182	   makes exploits relying on predictable memory locations less reliable.
2183
2184	   The order of allocations remains unchanged. Entropy is generated in
2185	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2186	   configuration have in average 30,000 different possible virtual
2187	   addresses for each memory section.
2188
2189	   If unsure, say Y.
2190
2191config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2192	hex "Physical memory mapping padding" if EXPERT
2193	depends on RANDOMIZE_MEMORY
2194	default "0xa" if MEMORY_HOTPLUG
2195	default "0x0"
2196	range 0x1 0x40 if MEMORY_HOTPLUG
2197	range 0x0 0x40
2198	---help---
2199	   Define the padding in terabytes added to the existing physical
2200	   memory size during kernel memory randomization. It is useful
2201	   for memory hotplug support but reduces the entropy available for
2202	   address randomization.
2203
2204	   If unsure, leave at the default value.
2205
2206config HOTPLUG_CPU
2207	bool "Support for hot-pluggable CPUs"
2208	depends on SMP
2209	---help---
2210	  Say Y here to allow turning CPUs off and on. CPUs can be
2211	  controlled through /sys/devices/system/cpu.
2212	  ( Note: power management support will enable this option
2213	    automatically on SMP systems. )
2214	  Say N if you want to disable CPU hotplug.
2215
2216config BOOTPARAM_HOTPLUG_CPU0
2217	bool "Set default setting of cpu0_hotpluggable"
2218	default n
2219	depends on HOTPLUG_CPU
2220	---help---
2221	  Set whether default state of cpu0_hotpluggable is on or off.
2222
2223	  Say Y here to enable CPU0 hotplug by default. If this switch
2224	  is turned on, there is no need to give cpu0_hotplug kernel
2225	  parameter and the CPU0 hotplug feature is enabled by default.
2226
2227	  Please note: there are two known CPU0 dependencies if you want
2228	  to enable the CPU0 hotplug feature either by this switch or by
2229	  cpu0_hotplug kernel parameter.
2230
2231	  First, resume from hibernate or suspend always starts from CPU0.
2232	  So hibernate and suspend are prevented if CPU0 is offline.
2233
2234	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2235	  offline if any interrupt can not migrate out of CPU0. There may
2236	  be other CPU0 dependencies.
2237
2238	  Please make sure the dependencies are under your control before
2239	  you enable this feature.
2240
2241	  Say N if you don't want to enable CPU0 hotplug feature by default.
2242	  You still can enable the CPU0 hotplug feature at boot by kernel
2243	  parameter cpu0_hotplug.
2244
2245config DEBUG_HOTPLUG_CPU0
2246	def_bool n
2247	prompt "Debug CPU0 hotplug"
2248	depends on HOTPLUG_CPU
2249	---help---
2250	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2251	  soon as possible and boots up userspace with CPU0 offlined. User
2252	  can online CPU0 back after boot time.
2253
2254	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2255	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2256	  compilation or giving cpu0_hotplug kernel parameter at boot.
2257
2258	  If unsure, say N.
2259
2260config COMPAT_VDSO
2261	def_bool n
2262	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2263	depends on COMPAT_32
2264	---help---
2265	  Certain buggy versions of glibc will crash if they are
2266	  presented with a 32-bit vDSO that is not mapped at the address
2267	  indicated in its segment table.
2268
2269	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2270	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2271	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2272	  the only released version with the bug, but OpenSUSE 9
2273	  contains a buggy "glibc 2.3.2".
2274
2275	  The symptom of the bug is that everything crashes on startup, saying:
2276	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2277
2278	  Saying Y here changes the default value of the vdso32 boot
2279	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2280	  This works around the glibc bug but hurts performance.
2281
2282	  If unsure, say N: if you are compiling your own kernel, you
2283	  are unlikely to be using a buggy version of glibc.
2284
2285choice
2286	prompt "vsyscall table for legacy applications"
2287	depends on X86_64
2288	default LEGACY_VSYSCALL_EMULATE
2289	help
2290	  Legacy user code that does not know how to find the vDSO expects
2291	  to be able to issue three syscalls by calling fixed addresses in
2292	  kernel space. Since this location is not randomized with ASLR,
2293	  it can be used to assist security vulnerability exploitation.
2294
2295	  This setting can be changed at boot time via the kernel command
2296	  line parameter vsyscall=[emulate|none].
2297
2298	  On a system with recent enough glibc (2.14 or newer) and no
2299	  static binaries, you can say None without a performance penalty
2300	  to improve security.
2301
2302	  If unsure, select "Emulate".
2303
2304	config LEGACY_VSYSCALL_EMULATE
2305		bool "Emulate"
2306		help
2307		  The kernel traps and emulates calls into the fixed
2308		  vsyscall address mapping. This makes the mapping
2309		  non-executable, but it still contains known contents,
2310		  which could be used in certain rare security vulnerability
2311		  exploits. This configuration is recommended when userspace
2312		  still uses the vsyscall area.
2313
2314	config LEGACY_VSYSCALL_NONE
2315		bool "None"
2316		help
2317		  There will be no vsyscall mapping at all. This will
2318		  eliminate any risk of ASLR bypass due to the vsyscall
2319		  fixed address mapping. Attempts to use the vsyscalls
2320		  will be reported to dmesg, so that either old or
2321		  malicious userspace programs can be identified.
2322
2323endchoice
2324
2325config CMDLINE_BOOL
2326	bool "Built-in kernel command line"
2327	---help---
2328	  Allow for specifying boot arguments to the kernel at
2329	  build time.  On some systems (e.g. embedded ones), it is
2330	  necessary or convenient to provide some or all of the
2331	  kernel boot arguments with the kernel itself (that is,
2332	  to not rely on the boot loader to provide them.)
2333
2334	  To compile command line arguments into the kernel,
2335	  set this option to 'Y', then fill in the
2336	  boot arguments in CONFIG_CMDLINE.
2337
2338	  Systems with fully functional boot loaders (i.e. non-embedded)
2339	  should leave this option set to 'N'.
2340
2341config CMDLINE
2342	string "Built-in kernel command string"
2343	depends on CMDLINE_BOOL
2344	default ""
2345	---help---
2346	  Enter arguments here that should be compiled into the kernel
2347	  image and used at boot time.  If the boot loader provides a
2348	  command line at boot time, it is appended to this string to
2349	  form the full kernel command line, when the system boots.
2350
2351	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2352	  change this behavior.
2353
2354	  In most cases, the command line (whether built-in or provided
2355	  by the boot loader) should specify the device for the root
2356	  file system.
2357
2358config CMDLINE_OVERRIDE
2359	bool "Built-in command line overrides boot loader arguments"
2360	depends on CMDLINE_BOOL
2361	---help---
2362	  Set this option to 'Y' to have the kernel ignore the boot loader
2363	  command line, and use ONLY the built-in command line.
2364
2365	  This is used to work around broken boot loaders.  This should
2366	  be set to 'N' under normal conditions.
2367
2368config MODIFY_LDT_SYSCALL
2369	bool "Enable the LDT (local descriptor table)" if EXPERT
2370	default y
2371	---help---
2372	  Linux can allow user programs to install a per-process x86
2373	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2374	  call.  This is required to run 16-bit or segmented code such as
2375	  DOSEMU or some Wine programs.  It is also used by some very old
2376	  threading libraries.
2377
2378	  Enabling this feature adds a small amount of overhead to
2379	  context switches and increases the low-level kernel attack
2380	  surface.  Disabling it removes the modify_ldt(2) system call.
2381
2382	  Saying 'N' here may make sense for embedded or server kernels.
2383
2384source "kernel/livepatch/Kconfig"
2385
2386endmenu
2387
2388config ARCH_HAS_ADD_PAGES
2389	def_bool y
2390	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2391
2392config ARCH_ENABLE_MEMORY_HOTPLUG
2393	def_bool y
2394	depends on X86_64 || (X86_32 && HIGHMEM)
2395
2396config ARCH_ENABLE_MEMORY_HOTREMOVE
2397	def_bool y
2398	depends on MEMORY_HOTPLUG
2399
2400config USE_PERCPU_NUMA_NODE_ID
2401	def_bool y
2402	depends on NUMA
2403
2404config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2405	def_bool y
2406	depends on X86_64 || X86_PAE
2407
2408config ARCH_ENABLE_HUGEPAGE_MIGRATION
2409	def_bool y
2410	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2411
2412config ARCH_ENABLE_THP_MIGRATION
2413	def_bool y
2414	depends on X86_64 && TRANSPARENT_HUGEPAGE
2415
2416menu "Power management and ACPI options"
2417
2418config ARCH_HIBERNATION_HEADER
2419	def_bool y
2420	depends on X86_64 && HIBERNATION
2421
2422source "kernel/power/Kconfig"
2423
2424source "drivers/acpi/Kconfig"
2425
2426source "drivers/sfi/Kconfig"
2427
2428config X86_APM_BOOT
2429	def_bool y
2430	depends on APM
2431
2432menuconfig APM
2433	tristate "APM (Advanced Power Management) BIOS support"
2434	depends on X86_32 && PM_SLEEP
2435	---help---
2436	  APM is a BIOS specification for saving power using several different
2437	  techniques. This is mostly useful for battery powered laptops with
2438	  APM compliant BIOSes. If you say Y here, the system time will be
2439	  reset after a RESUME operation, the /proc/apm device will provide
2440	  battery status information, and user-space programs will receive
2441	  notification of APM "events" (e.g. battery status change).
2442
2443	  If you select "Y" here, you can disable actual use of the APM
2444	  BIOS by passing the "apm=off" option to the kernel at boot time.
2445
2446	  Note that the APM support is almost completely disabled for
2447	  machines with more than one CPU.
2448
2449	  In order to use APM, you will need supporting software. For location
2450	  and more information, read <file:Documentation/power/apm-acpi.txt>
2451	  and the Battery Powered Linux mini-HOWTO, available from
2452	  <http://www.tldp.org/docs.html#howto>.
2453
2454	  This driver does not spin down disk drives (see the hdparm(8)
2455	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2456	  VESA-compliant "green" monitors.
2457
2458	  This driver does not support the TI 4000M TravelMate and the ACER
2459	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2460	  desktop machines also don't have compliant BIOSes, and this driver
2461	  may cause those machines to panic during the boot phase.
2462
2463	  Generally, if you don't have a battery in your machine, there isn't
2464	  much point in using this driver and you should say N. If you get
2465	  random kernel OOPSes or reboots that don't seem to be related to
2466	  anything, try disabling/enabling this option (or disabling/enabling
2467	  APM in your BIOS).
2468
2469	  Some other things you should try when experiencing seemingly random,
2470	  "weird" problems:
2471
2472	  1) make sure that you have enough swap space and that it is
2473	  enabled.
2474	  2) pass the "no-hlt" option to the kernel
2475	  3) switch on floating point emulation in the kernel and pass
2476	  the "no387" option to the kernel
2477	  4) pass the "floppy=nodma" option to the kernel
2478	  5) pass the "mem=4M" option to the kernel (thereby disabling
2479	  all but the first 4 MB of RAM)
2480	  6) make sure that the CPU is not over clocked.
2481	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2482	  8) disable the cache from your BIOS settings
2483	  9) install a fan for the video card or exchange video RAM
2484	  10) install a better fan for the CPU
2485	  11) exchange RAM chips
2486	  12) exchange the motherboard.
2487
2488	  To compile this driver as a module, choose M here: the
2489	  module will be called apm.
2490
2491if APM
2492
2493config APM_IGNORE_USER_SUSPEND
2494	bool "Ignore USER SUSPEND"
2495	---help---
2496	  This option will ignore USER SUSPEND requests. On machines with a
2497	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2498	  series notebooks, it is necessary to say Y because of a BIOS bug.
2499
2500config APM_DO_ENABLE
2501	bool "Enable PM at boot time"
2502	---help---
2503	  Enable APM features at boot time. From page 36 of the APM BIOS
2504	  specification: "When disabled, the APM BIOS does not automatically
2505	  power manage devices, enter the Standby State, enter the Suspend
2506	  State, or take power saving steps in response to CPU Idle calls."
2507	  This driver will make CPU Idle calls when Linux is idle (unless this
2508	  feature is turned off -- see "Do CPU IDLE calls", below). This
2509	  should always save battery power, but more complicated APM features
2510	  will be dependent on your BIOS implementation. You may need to turn
2511	  this option off if your computer hangs at boot time when using APM
2512	  support, or if it beeps continuously instead of suspending. Turn
2513	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2514	  T400CDT. This is off by default since most machines do fine without
2515	  this feature.
2516
2517config APM_CPU_IDLE
2518	depends on CPU_IDLE
2519	bool "Make CPU Idle calls when idle"
2520	---help---
2521	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2522	  On some machines, this can activate improved power savings, such as
2523	  a slowed CPU clock rate, when the machine is idle. These idle calls
2524	  are made after the idle loop has run for some length of time (e.g.,
2525	  333 mS). On some machines, this will cause a hang at boot time or
2526	  whenever the CPU becomes idle. (On machines with more than one CPU,
2527	  this option does nothing.)
2528
2529config APM_DISPLAY_BLANK
2530	bool "Enable console blanking using APM"
2531	---help---
2532	  Enable console blanking using the APM. Some laptops can use this to
2533	  turn off the LCD backlight when the screen blanker of the Linux
2534	  virtual console blanks the screen. Note that this is only used by
2535	  the virtual console screen blanker, and won't turn off the backlight
2536	  when using the X Window system. This also doesn't have anything to
2537	  do with your VESA-compliant power-saving monitor. Further, this
2538	  option doesn't work for all laptops -- it might not turn off your
2539	  backlight at all, or it might print a lot of errors to the console,
2540	  especially if you are using gpm.
2541
2542config APM_ALLOW_INTS
2543	bool "Allow interrupts during APM BIOS calls"
2544	---help---
2545	  Normally we disable external interrupts while we are making calls to
2546	  the APM BIOS as a measure to lessen the effects of a badly behaving
2547	  BIOS implementation.  The BIOS should reenable interrupts if it
2548	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2549	  many of the newer IBM Thinkpads.  If you experience hangs when you
2550	  suspend, try setting this to Y.  Otherwise, say N.
2551
2552endif # APM
2553
2554source "drivers/cpufreq/Kconfig"
2555
2556source "drivers/cpuidle/Kconfig"
2557
2558source "drivers/idle/Kconfig"
2559
2560endmenu
2561
2562
2563menu "Bus options (PCI etc.)"
2564
2565config PCI
2566	bool "PCI support"
2567	default y
2568	---help---
2569	  Find out whether you have a PCI motherboard. PCI is the name of a
2570	  bus system, i.e. the way the CPU talks to the other stuff inside
2571	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2572	  VESA. If you have PCI, say Y, otherwise N.
2573
2574choice
2575	prompt "PCI access mode"
2576	depends on X86_32 && PCI
2577	default PCI_GOANY
2578	---help---
2579	  On PCI systems, the BIOS can be used to detect the PCI devices and
2580	  determine their configuration. However, some old PCI motherboards
2581	  have BIOS bugs and may crash if this is done. Also, some embedded
2582	  PCI-based systems don't have any BIOS at all. Linux can also try to
2583	  detect the PCI hardware directly without using the BIOS.
2584
2585	  With this option, you can specify how Linux should detect the
2586	  PCI devices. If you choose "BIOS", the BIOS will be used,
2587	  if you choose "Direct", the BIOS won't be used, and if you
2588	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2589	  If you choose "Any", the kernel will try MMCONFIG, then the
2590	  direct access method and falls back to the BIOS if that doesn't
2591	  work. If unsure, go with the default, which is "Any".
2592
2593config PCI_GOBIOS
2594	bool "BIOS"
2595
2596config PCI_GOMMCONFIG
2597	bool "MMConfig"
2598
2599config PCI_GODIRECT
2600	bool "Direct"
2601
2602config PCI_GOOLPC
2603	bool "OLPC XO-1"
2604	depends on OLPC
2605
2606config PCI_GOANY
2607	bool "Any"
2608
2609endchoice
2610
2611config PCI_BIOS
2612	def_bool y
2613	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2614
2615# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2616config PCI_DIRECT
2617	def_bool y
2618	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2619
2620config PCI_MMCONFIG
2621	bool "Support mmconfig PCI config space access" if X86_64
2622	default y
2623	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2624	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2625
2626config PCI_OLPC
2627	def_bool y
2628	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2629
2630config PCI_XEN
2631	def_bool y
2632	depends on PCI && XEN
2633	select SWIOTLB_XEN
2634
2635config PCI_DOMAINS
2636	def_bool y
2637	depends on PCI
2638
2639config MMCONF_FAM10H
2640	def_bool y
2641	depends on X86_64 && PCI_MMCONFIG && ACPI
2642
2643config PCI_CNB20LE_QUIRK
2644	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2645	depends on PCI
2646	help
2647	  Read the PCI windows out of the CNB20LE host bridge. This allows
2648	  PCI hotplug to work on systems with the CNB20LE chipset which do
2649	  not have ACPI.
2650
2651	  There's no public spec for this chipset, and this functionality
2652	  is known to be incomplete.
2653
2654	  You should say N unless you know you need this.
2655
2656source "drivers/pci/Kconfig"
2657
2658config ISA_BUS
2659	bool "ISA bus support on modern systems" if EXPERT
2660	help
2661	  Expose ISA bus device drivers and options available for selection and
2662	  configuration. Enable this option if your target machine has an ISA
2663	  bus. ISA is an older system, displaced by PCI and newer bus
2664	  architectures -- if your target machine is modern, it probably does
2665	  not have an ISA bus.
2666
2667	  If unsure, say N.
2668
2669# x86_64 have no ISA slots, but can have ISA-style DMA.
2670config ISA_DMA_API
2671	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2672	default y
2673	help
2674	  Enables ISA-style DMA support for devices requiring such controllers.
2675	  If unsure, say Y.
2676
2677if X86_32
2678
2679config ISA
2680	bool "ISA support"
2681	---help---
2682	  Find out whether you have ISA slots on your motherboard.  ISA is the
2683	  name of a bus system, i.e. the way the CPU talks to the other stuff
2684	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2685	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2686	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2687
2688config EISA
2689	bool "EISA support"
2690	depends on ISA
2691	---help---
2692	  The Extended Industry Standard Architecture (EISA) bus was
2693	  developed as an open alternative to the IBM MicroChannel bus.
2694
2695	  The EISA bus provided some of the features of the IBM MicroChannel
2696	  bus while maintaining backward compatibility with cards made for
2697	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2698	  1995 when it was made obsolete by the PCI bus.
2699
2700	  Say Y here if you are building a kernel for an EISA-based machine.
2701
2702	  Otherwise, say N.
2703
2704source "drivers/eisa/Kconfig"
2705
2706config SCx200
2707	tristate "NatSemi SCx200 support"
2708	---help---
2709	  This provides basic support for National Semiconductor's
2710	  (now AMD's) Geode processors.  The driver probes for the
2711	  PCI-IDs of several on-chip devices, so its a good dependency
2712	  for other scx200_* drivers.
2713
2714	  If compiled as a module, the driver is named scx200.
2715
2716config SCx200HR_TIMER
2717	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2718	depends on SCx200
2719	default y
2720	---help---
2721	  This driver provides a clocksource built upon the on-chip
2722	  27MHz high-resolution timer.  Its also a workaround for
2723	  NSC Geode SC-1100's buggy TSC, which loses time when the
2724	  processor goes idle (as is done by the scheduler).  The
2725	  other workaround is idle=poll boot option.
2726
2727config OLPC
2728	bool "One Laptop Per Child support"
2729	depends on !X86_PAE
2730	select GPIOLIB
2731	select OF
2732	select OF_PROMTREE
2733	select IRQ_DOMAIN
2734	---help---
2735	  Add support for detecting the unique features of the OLPC
2736	  XO hardware.
2737
2738config OLPC_XO1_PM
2739	bool "OLPC XO-1 Power Management"
2740	depends on OLPC && MFD_CS5535 && PM_SLEEP
2741	select MFD_CORE
2742	---help---
2743	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2744
2745config OLPC_XO1_RTC
2746	bool "OLPC XO-1 Real Time Clock"
2747	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2748	---help---
2749	  Add support for the XO-1 real time clock, which can be used as a
2750	  programmable wakeup source.
2751
2752config OLPC_XO1_SCI
2753	bool "OLPC XO-1 SCI extras"
2754	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2755	depends on INPUT=y
2756	select POWER_SUPPLY
2757	---help---
2758	  Add support for SCI-based features of the OLPC XO-1 laptop:
2759	   - EC-driven system wakeups
2760	   - Power button
2761	   - Ebook switch
2762	   - Lid switch
2763	   - AC adapter status updates
2764	   - Battery status updates
2765
2766config OLPC_XO15_SCI
2767	bool "OLPC XO-1.5 SCI extras"
2768	depends on OLPC && ACPI
2769	select POWER_SUPPLY
2770	---help---
2771	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2772	   - EC-driven system wakeups
2773	   - AC adapter status updates
2774	   - Battery status updates
2775
2776config ALIX
2777	bool "PCEngines ALIX System Support (LED setup)"
2778	select GPIOLIB
2779	---help---
2780	  This option enables system support for the PCEngines ALIX.
2781	  At present this just sets up LEDs for GPIO control on
2782	  ALIX2/3/6 boards.  However, other system specific setup should
2783	  get added here.
2784
2785	  Note: You must still enable the drivers for GPIO and LED support
2786	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2787
2788	  Note: You have to set alix.force=1 for boards with Award BIOS.
2789
2790config NET5501
2791	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2792	select GPIOLIB
2793	---help---
2794	  This option enables system support for the Soekris Engineering net5501.
2795
2796config GEOS
2797	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2798	select GPIOLIB
2799	depends on DMI
2800	---help---
2801	  This option enables system support for the Traverse Technologies GEOS.
2802
2803config TS5500
2804	bool "Technologic Systems TS-5500 platform support"
2805	depends on MELAN
2806	select CHECK_SIGNATURE
2807	select NEW_LEDS
2808	select LEDS_CLASS
2809	---help---
2810	  This option enables system support for the Technologic Systems TS-5500.
2811
2812endif # X86_32
2813
2814config AMD_NB
2815	def_bool y
2816	depends on CPU_SUP_AMD && PCI
2817
2818source "drivers/pcmcia/Kconfig"
2819
2820config RAPIDIO
2821	tristate "RapidIO support"
2822	depends on PCI
2823	default n
2824	help
2825	  If enabled this option will include drivers and the core
2826	  infrastructure code to support RapidIO interconnect devices.
2827
2828source "drivers/rapidio/Kconfig"
2829
2830config X86_SYSFB
2831	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2832	help
2833	  Firmwares often provide initial graphics framebuffers so the BIOS,
2834	  bootloader or kernel can show basic video-output during boot for
2835	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2836	  Extensions and EFI-framebuffers for this, which are mostly limited
2837	  to x86.
2838	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2839	  framebuffers so the new generic system-framebuffer drivers can be
2840	  used on x86. If the framebuffer is not compatible with the generic
2841	  modes, it is adverticed as fallback platform framebuffer so legacy
2842	  drivers like efifb, vesafb and uvesafb can pick it up.
2843	  If this option is not selected, all system framebuffers are always
2844	  marked as fallback platform framebuffers as usual.
2845
2846	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2847	  not be able to pick up generic system framebuffers if this option
2848	  is selected. You are highly encouraged to enable simplefb as
2849	  replacement if you select this option. simplefb can correctly deal
2850	  with generic system framebuffers. But you should still keep vesafb
2851	  and others enabled as fallback if a system framebuffer is
2852	  incompatible with simplefb.
2853
2854	  If unsure, say Y.
2855
2856endmenu
2857
2858
2859menu "Executable file formats / Emulations"
2860
2861source "fs/Kconfig.binfmt"
2862
2863config IA32_EMULATION
2864	bool "IA32 Emulation"
2865	depends on X86_64
2866	select ARCH_WANT_OLD_COMPAT_IPC
2867	select BINFMT_ELF
2868	select COMPAT_BINFMT_ELF
2869	select COMPAT_OLD_SIGACTION
2870	---help---
2871	  Include code to run legacy 32-bit programs under a
2872	  64-bit kernel. You should likely turn this on, unless you're
2873	  100% sure that you don't have any 32-bit programs left.
2874
2875config IA32_AOUT
2876	tristate "IA32 a.out support"
2877	depends on IA32_EMULATION
2878	---help---
2879	  Support old a.out binaries in the 32bit emulation.
2880
2881config X86_X32
2882	bool "x32 ABI for 64-bit mode"
2883	depends on X86_64
2884	---help---
2885	  Include code to run binaries for the x32 native 32-bit ABI
2886	  for 64-bit processors.  An x32 process gets access to the
2887	  full 64-bit register file and wide data path while leaving
2888	  pointers at 32 bits for smaller memory footprint.
2889
2890	  You will need a recent binutils (2.22 or later) with
2891	  elf32_x86_64 support enabled to compile a kernel with this
2892	  option set.
2893
2894config COMPAT_32
2895	def_bool y
2896	depends on IA32_EMULATION || X86_32
2897	select HAVE_UID16
2898	select OLD_SIGSUSPEND3
2899
2900config COMPAT
2901	def_bool y
2902	depends on IA32_EMULATION || X86_X32
2903
2904if COMPAT
2905config COMPAT_FOR_U64_ALIGNMENT
2906	def_bool y
2907
2908config SYSVIPC_COMPAT
2909	def_bool y
2910	depends on SYSVIPC
2911endif
2912
2913endmenu
2914
2915
2916config HAVE_ATOMIC_IOMAP
2917	def_bool y
2918	depends on X86_32
2919
2920config X86_DEV_DMA_OPS
2921	bool
2922	depends on X86_64 || STA2X11
2923
2924config X86_DMA_REMAP
2925	bool
2926	depends on STA2X11
2927
2928config HAVE_GENERIC_GUP
2929	def_bool y
2930
2931source "net/Kconfig"
2932
2933source "drivers/Kconfig"
2934
2935source "drivers/firmware/Kconfig"
2936
2937source "fs/Kconfig"
2938
2939source "arch/x86/Kconfig.debug"
2940
2941source "security/Kconfig"
2942
2943source "crypto/Kconfig"
2944
2945source "arch/x86/kvm/Kconfig"
2946
2947source "lib/Kconfig"
2948