xref: /openbmc/linux/arch/x86/Kconfig (revision 6a767685)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if ARCH = "x86"
5	default ARCH != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select X86_DEV_DMA_OPS
32
33#
34# Arch settings
35#
36# ( Note that options that are marked 'if X86_64' could in principle be
37#   ported to 32-bit as well. )
38#
39config X86
40	def_bool y
41	#
42	# Note: keep this list sorted alphabetically
43	#
44	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
45	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
46	select ANON_INODES
47	select ARCH_CLOCKSOURCE_DATA
48	select ARCH_DISCARD_MEMBLOCK
49	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
50	select ARCH_HAS_DEBUG_VIRTUAL
51	select ARCH_HAS_DEVMEM_IS_ALLOWED
52	select ARCH_HAS_ELF_RANDOMIZE
53	select ARCH_HAS_FAST_MULTIPLIER
54	select ARCH_HAS_FORTIFY_SOURCE
55	select ARCH_HAS_GCOV_PROFILE_ALL
56	select ARCH_HAS_KCOV			if X86_64
57	select ARCH_HAS_PHYS_TO_DMA
58	select ARCH_HAS_MEMBARRIER_SYNC_CORE
59	select ARCH_HAS_PMEM_API		if X86_64
60	select ARCH_HAS_REFCOUNT
61	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
62	select ARCH_HAS_SET_MEMORY
63	select ARCH_HAS_SG_CHAIN
64	select ARCH_HAS_STRICT_KERNEL_RWX
65	select ARCH_HAS_STRICT_MODULE_RWX
66	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
67	select ARCH_HAS_UBSAN_SANITIZE_ALL
68	select ARCH_HAS_ZONE_DEVICE		if X86_64
69	select ARCH_HAVE_NMI_SAFE_CMPXCHG
70	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
71	select ARCH_MIGHT_HAVE_PC_PARPORT
72	select ARCH_MIGHT_HAVE_PC_SERIO
73	select ARCH_SUPPORTS_ATOMIC_RMW
74	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
75	select ARCH_USE_BUILTIN_BSWAP
76	select ARCH_USE_QUEUED_RWLOCKS
77	select ARCH_USE_QUEUED_SPINLOCKS
78	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
79	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
80	select ARCH_WANTS_THP_SWAP		if X86_64
81	select BUILDTIME_EXTABLE_SORT
82	select CLKEVT_I8253
83	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
84	select CLOCKSOURCE_WATCHDOG
85	select DCACHE_WORD_ACCESS
86	select EDAC_ATOMIC_SCRUB
87	select EDAC_SUPPORT
88	select GENERIC_CLOCKEVENTS
89	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
90	select GENERIC_CLOCKEVENTS_MIN_ADJUST
91	select GENERIC_CMOS_UPDATE
92	select GENERIC_CPU_AUTOPROBE
93	select GENERIC_CPU_VULNERABILITIES
94	select GENERIC_EARLY_IOREMAP
95	select GENERIC_FIND_FIRST_BIT
96	select GENERIC_IOMAP
97	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
98	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
99	select GENERIC_IRQ_MIGRATION		if SMP
100	select GENERIC_IRQ_PROBE
101	select GENERIC_IRQ_RESERVATION_MODE
102	select GENERIC_IRQ_SHOW
103	select GENERIC_PENDING_IRQ		if SMP
104	select GENERIC_SMP_IDLE_THREAD
105	select GENERIC_STRNCPY_FROM_USER
106	select GENERIC_STRNLEN_USER
107	select GENERIC_TIME_VSYSCALL
108	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
109	select HAVE_ACPI_APEI			if ACPI
110	select HAVE_ACPI_APEI_NMI		if ACPI
111	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
112	select HAVE_ARCH_AUDITSYSCALL
113	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
114	select HAVE_ARCH_JUMP_LABEL
115	select HAVE_ARCH_KASAN			if X86_64
116	select HAVE_ARCH_KGDB
117	select HAVE_ARCH_MMAP_RND_BITS		if MMU
118	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
119	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
120	select HAVE_ARCH_SECCOMP_FILTER
121	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
122	select HAVE_ARCH_TRACEHOOK
123	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
124	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
125	select HAVE_ARCH_VMAP_STACK		if X86_64
126	select HAVE_ARCH_WITHIN_STACK_FRAMES
127	select HAVE_CC_STACKPROTECTOR
128	select HAVE_CMPXCHG_DOUBLE
129	select HAVE_CMPXCHG_LOCAL
130	select HAVE_CONTEXT_TRACKING		if X86_64
131	select HAVE_COPY_THREAD_TLS
132	select HAVE_C_RECORDMCOUNT
133	select HAVE_DEBUG_KMEMLEAK
134	select HAVE_DEBUG_STACKOVERFLOW
135	select HAVE_DMA_API_DEBUG
136	select HAVE_DMA_CONTIGUOUS
137	select HAVE_DYNAMIC_FTRACE
138	select HAVE_DYNAMIC_FTRACE_WITH_REGS
139	select HAVE_EBPF_JIT			if X86_64
140	select HAVE_EFFICIENT_UNALIGNED_ACCESS
141	select HAVE_EXIT_THREAD
142	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
143	select HAVE_FTRACE_MCOUNT_RECORD
144	select HAVE_FUNCTION_GRAPH_TRACER
145	select HAVE_FUNCTION_TRACER
146	select HAVE_GCC_PLUGINS
147	select HAVE_HW_BREAKPOINT
148	select HAVE_IDE
149	select HAVE_IOREMAP_PROT
150	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
151	select HAVE_IRQ_TIME_ACCOUNTING
152	select HAVE_KERNEL_BZIP2
153	select HAVE_KERNEL_GZIP
154	select HAVE_KERNEL_LZ4
155	select HAVE_KERNEL_LZMA
156	select HAVE_KERNEL_LZO
157	select HAVE_KERNEL_XZ
158	select HAVE_KPROBES
159	select HAVE_KPROBES_ON_FTRACE
160	select HAVE_FUNCTION_ERROR_INJECTION
161	select HAVE_KRETPROBES
162	select HAVE_KVM
163	select HAVE_LIVEPATCH			if X86_64
164	select HAVE_MEMBLOCK
165	select HAVE_MEMBLOCK_NODE_MAP
166	select HAVE_MIXED_BREAKPOINTS_REGS
167	select HAVE_MOD_ARCH_SPECIFIC
168	select HAVE_NMI
169	select HAVE_OPROFILE
170	select HAVE_OPTPROBES
171	select HAVE_PCSPKR_PLATFORM
172	select HAVE_PERF_EVENTS
173	select HAVE_PERF_EVENTS_NMI
174	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
175	select HAVE_PERF_REGS
176	select HAVE_PERF_USER_STACK_DUMP
177	select HAVE_RCU_TABLE_FREE
178	select HAVE_REGS_AND_STACK_ACCESS_API
179	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
180	select HAVE_STACK_VALIDATION		if X86_64
181	select HAVE_SYSCALL_TRACEPOINTS
182	select HAVE_UNSTABLE_SCHED_CLOCK
183	select HAVE_USER_RETURN_NOTIFIER
184	select IRQ_FORCED_THREADING
185	select PCI_LOCKLESS_CONFIG
186	select PERF_EVENTS
187	select RTC_LIB
188	select RTC_MC146818_LIB
189	select SPARSE_IRQ
190	select SRCU
191	select SYSCTL_EXCEPTION_TRACE
192	select THREAD_INFO_IN_TASK
193	select USER_STACKTRACE_SUPPORT
194	select VIRT_TO_BUS
195	select X86_FEATURE_NAMES		if PROC_FS
196
197config INSTRUCTION_DECODER
198	def_bool y
199	depends on KPROBES || PERF_EVENTS || UPROBES
200
201config OUTPUT_FORMAT
202	string
203	default "elf32-i386" if X86_32
204	default "elf64-x86-64" if X86_64
205
206config ARCH_DEFCONFIG
207	string
208	default "arch/x86/configs/i386_defconfig" if X86_32
209	default "arch/x86/configs/x86_64_defconfig" if X86_64
210
211config LOCKDEP_SUPPORT
212	def_bool y
213
214config STACKTRACE_SUPPORT
215	def_bool y
216
217config MMU
218	def_bool y
219
220config ARCH_MMAP_RND_BITS_MIN
221	default 28 if 64BIT
222	default 8
223
224config ARCH_MMAP_RND_BITS_MAX
225	default 32 if 64BIT
226	default 16
227
228config ARCH_MMAP_RND_COMPAT_BITS_MIN
229	default 8
230
231config ARCH_MMAP_RND_COMPAT_BITS_MAX
232	default 16
233
234config SBUS
235	bool
236
237config NEED_DMA_MAP_STATE
238	def_bool y
239	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
240
241config NEED_SG_DMA_LENGTH
242	def_bool y
243
244config GENERIC_ISA_DMA
245	def_bool y
246	depends on ISA_DMA_API
247
248config GENERIC_BUG
249	def_bool y
250	depends on BUG
251	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
252
253config GENERIC_BUG_RELATIVE_POINTERS
254	bool
255
256config GENERIC_HWEIGHT
257	def_bool y
258
259config ARCH_MAY_HAVE_PC_FDC
260	def_bool y
261	depends on ISA_DMA_API
262
263config RWSEM_XCHGADD_ALGORITHM
264	def_bool y
265
266config GENERIC_CALIBRATE_DELAY
267	def_bool y
268
269config ARCH_HAS_CPU_RELAX
270	def_bool y
271
272config ARCH_HAS_CACHE_LINE_SIZE
273	def_bool y
274
275config HAVE_SETUP_PER_CPU_AREA
276	def_bool y
277
278config NEED_PER_CPU_EMBED_FIRST_CHUNK
279	def_bool y
280
281config NEED_PER_CPU_PAGE_FIRST_CHUNK
282	def_bool y
283
284config ARCH_HIBERNATION_POSSIBLE
285	def_bool y
286
287config ARCH_SUSPEND_POSSIBLE
288	def_bool y
289
290config ARCH_WANT_HUGE_PMD_SHARE
291	def_bool y
292
293config ARCH_WANT_GENERAL_HUGETLB
294	def_bool y
295
296config ZONE_DMA32
297	def_bool y if X86_64
298
299config AUDIT_ARCH
300	def_bool y if X86_64
301
302config ARCH_SUPPORTS_OPTIMIZED_INLINING
303	def_bool y
304
305config ARCH_SUPPORTS_DEBUG_PAGEALLOC
306	def_bool y
307
308config KASAN_SHADOW_OFFSET
309	hex
310	depends on KASAN
311	default 0xdffffc0000000000
312
313config HAVE_INTEL_TXT
314	def_bool y
315	depends on INTEL_IOMMU && ACPI
316
317config X86_32_SMP
318	def_bool y
319	depends on X86_32 && SMP
320
321config X86_64_SMP
322	def_bool y
323	depends on X86_64 && SMP
324
325config X86_32_LAZY_GS
326	def_bool y
327	depends on X86_32 && CC_STACKPROTECTOR_NONE
328
329config ARCH_SUPPORTS_UPROBES
330	def_bool y
331
332config FIX_EARLYCON_MEM
333	def_bool y
334
335config PGTABLE_LEVELS
336	int
337	default 5 if X86_5LEVEL
338	default 4 if X86_64
339	default 3 if X86_PAE
340	default 2
341
342source "init/Kconfig"
343source "kernel/Kconfig.freezer"
344
345menu "Processor type and features"
346
347config ZONE_DMA
348	bool "DMA memory allocation support" if EXPERT
349	default y
350	help
351	  DMA memory allocation support allows devices with less than 32-bit
352	  addressing to allocate within the first 16MB of address space.
353	  Disable if no such devices will be used.
354
355	  If unsure, say Y.
356
357config SMP
358	bool "Symmetric multi-processing support"
359	---help---
360	  This enables support for systems with more than one CPU. If you have
361	  a system with only one CPU, say N. If you have a system with more
362	  than one CPU, say Y.
363
364	  If you say N here, the kernel will run on uni- and multiprocessor
365	  machines, but will use only one CPU of a multiprocessor machine. If
366	  you say Y here, the kernel will run on many, but not all,
367	  uniprocessor machines. On a uniprocessor machine, the kernel
368	  will run faster if you say N here.
369
370	  Note that if you say Y here and choose architecture "586" or
371	  "Pentium" under "Processor family", the kernel will not work on 486
372	  architectures. Similarly, multiprocessor kernels for the "PPro"
373	  architecture may not work on all Pentium based boards.
374
375	  People using multiprocessor machines who say Y here should also say
376	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
377	  Management" code will be disabled if you say Y here.
378
379	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
380	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
381	  <http://www.tldp.org/docs.html#howto>.
382
383	  If you don't know what to do here, say N.
384
385config X86_FEATURE_NAMES
386	bool "Processor feature human-readable names" if EMBEDDED
387	default y
388	---help---
389	  This option compiles in a table of x86 feature bits and corresponding
390	  names.  This is required to support /proc/cpuinfo and a few kernel
391	  messages.  You can disable this to save space, at the expense of
392	  making those few kernel messages show numeric feature bits instead.
393
394	  If in doubt, say Y.
395
396config X86_FAST_FEATURE_TESTS
397	bool "Fast CPU feature tests" if EMBEDDED
398	default y
399	---help---
400	  Some fast-paths in the kernel depend on the capabilities of the CPU.
401	  Say Y here for the kernel to patch in the appropriate code at runtime
402	  based on the capabilities of the CPU. The infrastructure for patching
403	  code at runtime takes up some additional space; space-constrained
404	  embedded systems may wish to say N here to produce smaller, slightly
405	  slower code.
406
407config X86_X2APIC
408	bool "Support x2apic"
409	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
410	---help---
411	  This enables x2apic support on CPUs that have this feature.
412
413	  This allows 32-bit apic IDs (so it can support very large systems),
414	  and accesses the local apic via MSRs not via mmio.
415
416	  If you don't know what to do here, say N.
417
418config X86_MPPARSE
419	bool "Enable MPS table" if ACPI || SFI
420	default y
421	depends on X86_LOCAL_APIC
422	---help---
423	  For old smp systems that do not have proper acpi support. Newer systems
424	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
425
426config GOLDFISH
427       def_bool y
428       depends on X86_GOLDFISH
429
430config RETPOLINE
431	bool "Avoid speculative indirect branches in kernel"
432	default y
433	help
434	  Compile kernel with the retpoline compiler options to guard against
435	  kernel-to-user data leaks by avoiding speculative indirect
436	  branches. Requires a compiler with -mindirect-branch=thunk-extern
437	  support for full protection. The kernel may run slower.
438
439	  Without compiler support, at least indirect branches in assembler
440	  code are eliminated. Since this includes the syscall entry path,
441	  it is not entirely pointless.
442
443config INTEL_RDT
444	bool "Intel Resource Director Technology support"
445	default n
446	depends on X86 && CPU_SUP_INTEL
447	select KERNFS
448	help
449	  Select to enable resource allocation and monitoring which are
450	  sub-features of Intel Resource Director Technology(RDT). More
451	  information about RDT can be found in the Intel x86
452	  Architecture Software Developer Manual.
453
454	  Say N if unsure.
455
456if X86_32
457config X86_BIGSMP
458	bool "Support for big SMP systems with more than 8 CPUs"
459	depends on SMP
460	---help---
461	  This option is needed for the systems that have more than 8 CPUs
462
463config X86_EXTENDED_PLATFORM
464	bool "Support for extended (non-PC) x86 platforms"
465	default y
466	---help---
467	  If you disable this option then the kernel will only support
468	  standard PC platforms. (which covers the vast majority of
469	  systems out there.)
470
471	  If you enable this option then you'll be able to select support
472	  for the following (non-PC) 32 bit x86 platforms:
473		Goldfish (Android emulator)
474		AMD Elan
475		RDC R-321x SoC
476		SGI 320/540 (Visual Workstation)
477		STA2X11-based (e.g. Northville)
478		Moorestown MID devices
479
480	  If you have one of these systems, or if you want to build a
481	  generic distribution kernel, say Y here - otherwise say N.
482endif
483
484if X86_64
485config X86_EXTENDED_PLATFORM
486	bool "Support for extended (non-PC) x86 platforms"
487	default y
488	---help---
489	  If you disable this option then the kernel will only support
490	  standard PC platforms. (which covers the vast majority of
491	  systems out there.)
492
493	  If you enable this option then you'll be able to select support
494	  for the following (non-PC) 64 bit x86 platforms:
495		Numascale NumaChip
496		ScaleMP vSMP
497		SGI Ultraviolet
498
499	  If you have one of these systems, or if you want to build a
500	  generic distribution kernel, say Y here - otherwise say N.
501endif
502# This is an alphabetically sorted list of 64 bit extended platforms
503# Please maintain the alphabetic order if and when there are additions
504config X86_NUMACHIP
505	bool "Numascale NumaChip"
506	depends on X86_64
507	depends on X86_EXTENDED_PLATFORM
508	depends on NUMA
509	depends on SMP
510	depends on X86_X2APIC
511	depends on PCI_MMCONFIG
512	---help---
513	  Adds support for Numascale NumaChip large-SMP systems. Needed to
514	  enable more than ~168 cores.
515	  If you don't have one of these, you should say N here.
516
517config X86_VSMP
518	bool "ScaleMP vSMP"
519	select HYPERVISOR_GUEST
520	select PARAVIRT
521	depends on X86_64 && PCI
522	depends on X86_EXTENDED_PLATFORM
523	depends on SMP
524	---help---
525	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
526	  supposed to run on these EM64T-based machines.  Only choose this option
527	  if you have one of these machines.
528
529config X86_UV
530	bool "SGI Ultraviolet"
531	depends on X86_64
532	depends on X86_EXTENDED_PLATFORM
533	depends on NUMA
534	depends on EFI
535	depends on X86_X2APIC
536	depends on PCI
537	---help---
538	  This option is needed in order to support SGI Ultraviolet systems.
539	  If you don't have one of these, you should say N here.
540
541# Following is an alphabetically sorted list of 32 bit extended platforms
542# Please maintain the alphabetic order if and when there are additions
543
544config X86_GOLDFISH
545       bool "Goldfish (Virtual Platform)"
546       depends on X86_EXTENDED_PLATFORM
547       ---help---
548	 Enable support for the Goldfish virtual platform used primarily
549	 for Android development. Unless you are building for the Android
550	 Goldfish emulator say N here.
551
552config X86_INTEL_CE
553	bool "CE4100 TV platform"
554	depends on PCI
555	depends on PCI_GODIRECT
556	depends on X86_IO_APIC
557	depends on X86_32
558	depends on X86_EXTENDED_PLATFORM
559	select X86_REBOOTFIXUPS
560	select OF
561	select OF_EARLY_FLATTREE
562	---help---
563	  Select for the Intel CE media processor (CE4100) SOC.
564	  This option compiles in support for the CE4100 SOC for settop
565	  boxes and media devices.
566
567config X86_INTEL_MID
568	bool "Intel MID platform support"
569	depends on X86_EXTENDED_PLATFORM
570	depends on X86_PLATFORM_DEVICES
571	depends on PCI
572	depends on X86_64 || (PCI_GOANY && X86_32)
573	depends on X86_IO_APIC
574	select SFI
575	select I2C
576	select DW_APB_TIMER
577	select APB_TIMER
578	select INTEL_SCU_IPC
579	select MFD_INTEL_MSIC
580	---help---
581	  Select to build a kernel capable of supporting Intel MID (Mobile
582	  Internet Device) platform systems which do not have the PCI legacy
583	  interfaces. If you are building for a PC class system say N here.
584
585	  Intel MID platforms are based on an Intel processor and chipset which
586	  consume less power than most of the x86 derivatives.
587
588config X86_INTEL_QUARK
589	bool "Intel Quark platform support"
590	depends on X86_32
591	depends on X86_EXTENDED_PLATFORM
592	depends on X86_PLATFORM_DEVICES
593	depends on X86_TSC
594	depends on PCI
595	depends on PCI_GOANY
596	depends on X86_IO_APIC
597	select IOSF_MBI
598	select INTEL_IMR
599	select COMMON_CLK
600	---help---
601	  Select to include support for Quark X1000 SoC.
602	  Say Y here if you have a Quark based system such as the Arduino
603	  compatible Intel Galileo.
604
605config X86_INTEL_LPSS
606	bool "Intel Low Power Subsystem Support"
607	depends on X86 && ACPI
608	select COMMON_CLK
609	select PINCTRL
610	select IOSF_MBI
611	---help---
612	  Select to build support for Intel Low Power Subsystem such as
613	  found on Intel Lynxpoint PCH. Selecting this option enables
614	  things like clock tree (common clock framework) and pincontrol
615	  which are needed by the LPSS peripheral drivers.
616
617config X86_AMD_PLATFORM_DEVICE
618	bool "AMD ACPI2Platform devices support"
619	depends on ACPI
620	select COMMON_CLK
621	select PINCTRL
622	---help---
623	  Select to interpret AMD specific ACPI device to platform device
624	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
625	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
626	  implemented under PINCTRL subsystem.
627
628config IOSF_MBI
629	tristate "Intel SoC IOSF Sideband support for SoC platforms"
630	depends on PCI
631	---help---
632	  This option enables sideband register access support for Intel SoC
633	  platforms. On these platforms the IOSF sideband is used in lieu of
634	  MSR's for some register accesses, mostly but not limited to thermal
635	  and power. Drivers may query the availability of this device to
636	  determine if they need the sideband in order to work on these
637	  platforms. The sideband is available on the following SoC products.
638	  This list is not meant to be exclusive.
639	   - BayTrail
640	   - Braswell
641	   - Quark
642
643	  You should say Y if you are running a kernel on one of these SoC's.
644
645config IOSF_MBI_DEBUG
646	bool "Enable IOSF sideband access through debugfs"
647	depends on IOSF_MBI && DEBUG_FS
648	---help---
649	  Select this option to expose the IOSF sideband access registers (MCR,
650	  MDR, MCRX) through debugfs to write and read register information from
651	  different units on the SoC. This is most useful for obtaining device
652	  state information for debug and analysis. As this is a general access
653	  mechanism, users of this option would have specific knowledge of the
654	  device they want to access.
655
656	  If you don't require the option or are in doubt, say N.
657
658config X86_RDC321X
659	bool "RDC R-321x SoC"
660	depends on X86_32
661	depends on X86_EXTENDED_PLATFORM
662	select M486
663	select X86_REBOOTFIXUPS
664	---help---
665	  This option is needed for RDC R-321x system-on-chip, also known
666	  as R-8610-(G).
667	  If you don't have one of these chips, you should say N here.
668
669config X86_32_NON_STANDARD
670	bool "Support non-standard 32-bit SMP architectures"
671	depends on X86_32 && SMP
672	depends on X86_EXTENDED_PLATFORM
673	---help---
674	  This option compiles in the bigsmp and STA2X11 default
675	  subarchitectures.  It is intended for a generic binary
676	  kernel. If you select them all, kernel will probe it one by
677	  one and will fallback to default.
678
679# Alphabetically sorted list of Non standard 32 bit platforms
680
681config X86_SUPPORTS_MEMORY_FAILURE
682	def_bool y
683	# MCE code calls memory_failure():
684	depends on X86_MCE
685	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
686	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
687	depends on X86_64 || !SPARSEMEM
688	select ARCH_SUPPORTS_MEMORY_FAILURE
689
690config STA2X11
691	bool "STA2X11 Companion Chip Support"
692	depends on X86_32_NON_STANDARD && PCI
693	select X86_DEV_DMA_OPS
694	select X86_DMA_REMAP
695	select SWIOTLB
696	select MFD_STA2X11
697	select GPIOLIB
698	default n
699	---help---
700	  This adds support for boards based on the STA2X11 IO-Hub,
701	  a.k.a. "ConneXt". The chip is used in place of the standard
702	  PC chipset, so all "standard" peripherals are missing. If this
703	  option is selected the kernel will still be able to boot on
704	  standard PC machines.
705
706config X86_32_IRIS
707	tristate "Eurobraille/Iris poweroff module"
708	depends on X86_32
709	---help---
710	  The Iris machines from EuroBraille do not have APM or ACPI support
711	  to shut themselves down properly.  A special I/O sequence is
712	  needed to do so, which is what this module does at
713	  kernel shutdown.
714
715	  This is only for Iris machines from EuroBraille.
716
717	  If unused, say N.
718
719config SCHED_OMIT_FRAME_POINTER
720	def_bool y
721	prompt "Single-depth WCHAN output"
722	depends on X86
723	---help---
724	  Calculate simpler /proc/<PID>/wchan values. If this option
725	  is disabled then wchan values will recurse back to the
726	  caller function. This provides more accurate wchan values,
727	  at the expense of slightly more scheduling overhead.
728
729	  If in doubt, say "Y".
730
731menuconfig HYPERVISOR_GUEST
732	bool "Linux guest support"
733	---help---
734	  Say Y here to enable options for running Linux under various hyper-
735	  visors. This option enables basic hypervisor detection and platform
736	  setup.
737
738	  If you say N, all options in this submenu will be skipped and
739	  disabled, and Linux guest support won't be built in.
740
741if HYPERVISOR_GUEST
742
743config PARAVIRT
744	bool "Enable paravirtualization code"
745	---help---
746	  This changes the kernel so it can modify itself when it is run
747	  under a hypervisor, potentially improving performance significantly
748	  over full virtualization.  However, when run without a hypervisor
749	  the kernel is theoretically slower and slightly larger.
750
751config PARAVIRT_DEBUG
752	bool "paravirt-ops debugging"
753	depends on PARAVIRT && DEBUG_KERNEL
754	---help---
755	  Enable to debug paravirt_ops internals.  Specifically, BUG if
756	  a paravirt_op is missing when it is called.
757
758config PARAVIRT_SPINLOCKS
759	bool "Paravirtualization layer for spinlocks"
760	depends on PARAVIRT && SMP
761	---help---
762	  Paravirtualized spinlocks allow a pvops backend to replace the
763	  spinlock implementation with something virtualization-friendly
764	  (for example, block the virtual CPU rather than spinning).
765
766	  It has a minimal impact on native kernels and gives a nice performance
767	  benefit on paravirtualized KVM / Xen kernels.
768
769	  If you are unsure how to answer this question, answer Y.
770
771config QUEUED_LOCK_STAT
772	bool "Paravirt queued spinlock statistics"
773	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
774	---help---
775	  Enable the collection of statistical data on the slowpath
776	  behavior of paravirtualized queued spinlocks and report
777	  them on debugfs.
778
779source "arch/x86/xen/Kconfig"
780
781config KVM_GUEST
782	bool "KVM Guest support (including kvmclock)"
783	depends on PARAVIRT
784	select PARAVIRT_CLOCK
785	default y
786	---help---
787	  This option enables various optimizations for running under the KVM
788	  hypervisor. It includes a paravirtualized clock, so that instead
789	  of relying on a PIT (or probably other) emulation by the
790	  underlying device model, the host provides the guest with
791	  timing infrastructure such as time of day, and system time
792
793config KVM_DEBUG_FS
794	bool "Enable debug information for KVM Guests in debugfs"
795	depends on KVM_GUEST && DEBUG_FS
796	default n
797	---help---
798	  This option enables collection of various statistics for KVM guest.
799	  Statistics are displayed in debugfs filesystem. Enabling this option
800	  may incur significant overhead.
801
802config PARAVIRT_TIME_ACCOUNTING
803	bool "Paravirtual steal time accounting"
804	depends on PARAVIRT
805	default n
806	---help---
807	  Select this option to enable fine granularity task steal time
808	  accounting. Time spent executing other tasks in parallel with
809	  the current vCPU is discounted from the vCPU power. To account for
810	  that, there can be a small performance impact.
811
812	  If in doubt, say N here.
813
814config PARAVIRT_CLOCK
815	bool
816
817config JAILHOUSE_GUEST
818	bool "Jailhouse non-root cell support"
819	depends on X86_64 && PCI
820	select X86_PM_TIMER
821	---help---
822	  This option allows to run Linux as guest in a Jailhouse non-root
823	  cell. You can leave this option disabled if you only want to start
824	  Jailhouse and run Linux afterwards in the root cell.
825
826endif #HYPERVISOR_GUEST
827
828config NO_BOOTMEM
829	def_bool y
830
831source "arch/x86/Kconfig.cpu"
832
833config HPET_TIMER
834	def_bool X86_64
835	prompt "HPET Timer Support" if X86_32
836	---help---
837	  Use the IA-PC HPET (High Precision Event Timer) to manage
838	  time in preference to the PIT and RTC, if a HPET is
839	  present.
840	  HPET is the next generation timer replacing legacy 8254s.
841	  The HPET provides a stable time base on SMP
842	  systems, unlike the TSC, but it is more expensive to access,
843	  as it is off-chip.  The interface used is documented
844	  in the HPET spec, revision 1.
845
846	  You can safely choose Y here.  However, HPET will only be
847	  activated if the platform and the BIOS support this feature.
848	  Otherwise the 8254 will be used for timing services.
849
850	  Choose N to continue using the legacy 8254 timer.
851
852config HPET_EMULATE_RTC
853	def_bool y
854	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
855
856config APB_TIMER
857       def_bool y if X86_INTEL_MID
858       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
859       select DW_APB_TIMER
860       depends on X86_INTEL_MID && SFI
861       help
862         APB timer is the replacement for 8254, HPET on X86 MID platforms.
863         The APBT provides a stable time base on SMP
864         systems, unlike the TSC, but it is more expensive to access,
865         as it is off-chip. APB timers are always running regardless of CPU
866         C states, they are used as per CPU clockevent device when possible.
867
868# Mark as expert because too many people got it wrong.
869# The code disables itself when not needed.
870config DMI
871	default y
872	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
873	bool "Enable DMI scanning" if EXPERT
874	---help---
875	  Enabled scanning of DMI to identify machine quirks. Say Y
876	  here unless you have verified that your setup is not
877	  affected by entries in the DMI blacklist. Required by PNP
878	  BIOS code.
879
880config GART_IOMMU
881	bool "Old AMD GART IOMMU support"
882	select SWIOTLB
883	depends on X86_64 && PCI && AMD_NB
884	---help---
885	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
886	  GART based hardware IOMMUs.
887
888	  The GART supports full DMA access for devices with 32-bit access
889	  limitations, on systems with more than 3 GB. This is usually needed
890	  for USB, sound, many IDE/SATA chipsets and some other devices.
891
892	  Newer systems typically have a modern AMD IOMMU, supported via
893	  the CONFIG_AMD_IOMMU=y config option.
894
895	  In normal configurations this driver is only active when needed:
896	  there's more than 3 GB of memory and the system contains a
897	  32-bit limited device.
898
899	  If unsure, say Y.
900
901config CALGARY_IOMMU
902	bool "IBM Calgary IOMMU support"
903	select SWIOTLB
904	depends on X86_64 && PCI
905	---help---
906	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
907	  systems. Needed to run systems with more than 3GB of memory
908	  properly with 32-bit PCI devices that do not support DAC
909	  (Double Address Cycle). Calgary also supports bus level
910	  isolation, where all DMAs pass through the IOMMU.  This
911	  prevents them from going anywhere except their intended
912	  destination. This catches hard-to-find kernel bugs and
913	  mis-behaving drivers and devices that do not use the DMA-API
914	  properly to set up their DMA buffers.  The IOMMU can be
915	  turned off at boot time with the iommu=off parameter.
916	  Normally the kernel will make the right choice by itself.
917	  If unsure, say Y.
918
919config CALGARY_IOMMU_ENABLED_BY_DEFAULT
920	def_bool y
921	prompt "Should Calgary be enabled by default?"
922	depends on CALGARY_IOMMU
923	---help---
924	  Should Calgary be enabled by default? if you choose 'y', Calgary
925	  will be used (if it exists). If you choose 'n', Calgary will not be
926	  used even if it exists. If you choose 'n' and would like to use
927	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
928	  If unsure, say Y.
929
930# need this always selected by IOMMU for the VIA workaround
931config SWIOTLB
932	def_bool y if X86_64
933	---help---
934	  Support for software bounce buffers used on x86-64 systems
935	  which don't have a hardware IOMMU. Using this PCI devices
936	  which can only access 32-bits of memory can be used on systems
937	  with more than 3 GB of memory.
938	  If unsure, say Y.
939
940config IOMMU_HELPER
941	def_bool y
942	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
943
944config MAXSMP
945	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
946	depends on X86_64 && SMP && DEBUG_KERNEL
947	select CPUMASK_OFFSTACK
948	---help---
949	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
950	  If unsure, say N.
951
952#
953# The maximum number of CPUs supported:
954#
955# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
956# and which can be configured interactively in the
957# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
958#
959# The ranges are different on 32-bit and 64-bit kernels, depending on
960# hardware capabilities and scalability features of the kernel.
961#
962# ( If MAXSMP is enabled we just use the highest possible value and disable
963#   interactive configuration. )
964#
965
966config NR_CPUS_RANGE_BEGIN
967	int
968	default NR_CPUS_RANGE_END if MAXSMP
969	default    1 if !SMP
970	default    2
971
972config NR_CPUS_RANGE_END
973	int
974	depends on X86_32
975	default   64 if  SMP &&  X86_BIGSMP
976	default    8 if  SMP && !X86_BIGSMP
977	default    1 if !SMP
978
979config NR_CPUS_RANGE_END
980	int
981	depends on X86_64
982	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
983	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
984	default    1 if !SMP
985
986config NR_CPUS_DEFAULT
987	int
988	depends on X86_32
989	default   32 if  X86_BIGSMP
990	default    8 if  SMP
991	default    1 if !SMP
992
993config NR_CPUS_DEFAULT
994	int
995	depends on X86_64
996	default 8192 if  MAXSMP
997	default   64 if  SMP
998	default    1 if !SMP
999
1000config NR_CPUS
1001	int "Maximum number of CPUs" if SMP && !MAXSMP
1002	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1003	default NR_CPUS_DEFAULT
1004	---help---
1005	  This allows you to specify the maximum number of CPUs which this
1006	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1007	  supported value is 8192, otherwise the maximum value is 512.  The
1008	  minimum value which makes sense is 2.
1009
1010	  This is purely to save memory: each supported CPU adds about 8KB
1011	  to the kernel image.
1012
1013config SCHED_SMT
1014	bool "SMT (Hyperthreading) scheduler support"
1015	depends on SMP
1016	---help---
1017	  SMT scheduler support improves the CPU scheduler's decision making
1018	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1019	  cost of slightly increased overhead in some places. If unsure say
1020	  N here.
1021
1022config SCHED_MC
1023	def_bool y
1024	prompt "Multi-core scheduler support"
1025	depends on SMP
1026	---help---
1027	  Multi-core scheduler support improves the CPU scheduler's decision
1028	  making when dealing with multi-core CPU chips at a cost of slightly
1029	  increased overhead in some places. If unsure say N here.
1030
1031config SCHED_MC_PRIO
1032	bool "CPU core priorities scheduler support"
1033	depends on SCHED_MC && CPU_SUP_INTEL
1034	select X86_INTEL_PSTATE
1035	select CPU_FREQ
1036	default y
1037	---help---
1038	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1039	  core ordering determined at manufacturing time, which allows
1040	  certain cores to reach higher turbo frequencies (when running
1041	  single threaded workloads) than others.
1042
1043	  Enabling this kernel feature teaches the scheduler about
1044	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1045	  scheduler's CPU selection logic accordingly, so that higher
1046	  overall system performance can be achieved.
1047
1048	  This feature will have no effect on CPUs without this feature.
1049
1050	  If unsure say Y here.
1051
1052source "kernel/Kconfig.preempt"
1053
1054config UP_LATE_INIT
1055       def_bool y
1056       depends on !SMP && X86_LOCAL_APIC
1057
1058config X86_UP_APIC
1059	bool "Local APIC support on uniprocessors" if !PCI_MSI
1060	default PCI_MSI
1061	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1062	---help---
1063	  A local APIC (Advanced Programmable Interrupt Controller) is an
1064	  integrated interrupt controller in the CPU. If you have a single-CPU
1065	  system which has a processor with a local APIC, you can say Y here to
1066	  enable and use it. If you say Y here even though your machine doesn't
1067	  have a local APIC, then the kernel will still run with no slowdown at
1068	  all. The local APIC supports CPU-generated self-interrupts (timer,
1069	  performance counters), and the NMI watchdog which detects hard
1070	  lockups.
1071
1072config X86_UP_IOAPIC
1073	bool "IO-APIC support on uniprocessors"
1074	depends on X86_UP_APIC
1075	---help---
1076	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1077	  SMP-capable replacement for PC-style interrupt controllers. Most
1078	  SMP systems and many recent uniprocessor systems have one.
1079
1080	  If you have a single-CPU system with an IO-APIC, you can say Y here
1081	  to use it. If you say Y here even though your machine doesn't have
1082	  an IO-APIC, then the kernel will still run with no slowdown at all.
1083
1084config X86_LOCAL_APIC
1085	def_bool y
1086	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1087	select IRQ_DOMAIN_HIERARCHY
1088	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1089
1090config X86_IO_APIC
1091	def_bool y
1092	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1093
1094config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1095	bool "Reroute for broken boot IRQs"
1096	depends on X86_IO_APIC
1097	---help---
1098	  This option enables a workaround that fixes a source of
1099	  spurious interrupts. This is recommended when threaded
1100	  interrupt handling is used on systems where the generation of
1101	  superfluous "boot interrupts" cannot be disabled.
1102
1103	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1104	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1105	  kernel does during interrupt handling). On chipsets where this
1106	  boot IRQ generation cannot be disabled, this workaround keeps
1107	  the original IRQ line masked so that only the equivalent "boot
1108	  IRQ" is delivered to the CPUs. The workaround also tells the
1109	  kernel to set up the IRQ handler on the boot IRQ line. In this
1110	  way only one interrupt is delivered to the kernel. Otherwise
1111	  the spurious second interrupt may cause the kernel to bring
1112	  down (vital) interrupt lines.
1113
1114	  Only affects "broken" chipsets. Interrupt sharing may be
1115	  increased on these systems.
1116
1117config X86_MCE
1118	bool "Machine Check / overheating reporting"
1119	select GENERIC_ALLOCATOR
1120	default y
1121	---help---
1122	  Machine Check support allows the processor to notify the
1123	  kernel if it detects a problem (e.g. overheating, data corruption).
1124	  The action the kernel takes depends on the severity of the problem,
1125	  ranging from warning messages to halting the machine.
1126
1127config X86_MCELOG_LEGACY
1128	bool "Support for deprecated /dev/mcelog character device"
1129	depends on X86_MCE
1130	---help---
1131	  Enable support for /dev/mcelog which is needed by the old mcelog
1132	  userspace logging daemon. Consider switching to the new generation
1133	  rasdaemon solution.
1134
1135config X86_MCE_INTEL
1136	def_bool y
1137	prompt "Intel MCE features"
1138	depends on X86_MCE && X86_LOCAL_APIC
1139	---help---
1140	   Additional support for intel specific MCE features such as
1141	   the thermal monitor.
1142
1143config X86_MCE_AMD
1144	def_bool y
1145	prompt "AMD MCE features"
1146	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1147	---help---
1148	   Additional support for AMD specific MCE features such as
1149	   the DRAM Error Threshold.
1150
1151config X86_ANCIENT_MCE
1152	bool "Support for old Pentium 5 / WinChip machine checks"
1153	depends on X86_32 && X86_MCE
1154	---help---
1155	  Include support for machine check handling on old Pentium 5 or WinChip
1156	  systems. These typically need to be enabled explicitly on the command
1157	  line.
1158
1159config X86_MCE_THRESHOLD
1160	depends on X86_MCE_AMD || X86_MCE_INTEL
1161	def_bool y
1162
1163config X86_MCE_INJECT
1164	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1165	tristate "Machine check injector support"
1166	---help---
1167	  Provide support for injecting machine checks for testing purposes.
1168	  If you don't know what a machine check is and you don't do kernel
1169	  QA it is safe to say n.
1170
1171config X86_THERMAL_VECTOR
1172	def_bool y
1173	depends on X86_MCE_INTEL
1174
1175source "arch/x86/events/Kconfig"
1176
1177config X86_LEGACY_VM86
1178	bool "Legacy VM86 support"
1179	default n
1180	depends on X86_32
1181	---help---
1182	  This option allows user programs to put the CPU into V8086
1183	  mode, which is an 80286-era approximation of 16-bit real mode.
1184
1185	  Some very old versions of X and/or vbetool require this option
1186	  for user mode setting.  Similarly, DOSEMU will use it if
1187	  available to accelerate real mode DOS programs.  However, any
1188	  recent version of DOSEMU, X, or vbetool should be fully
1189	  functional even without kernel VM86 support, as they will all
1190	  fall back to software emulation. Nevertheless, if you are using
1191	  a 16-bit DOS program where 16-bit performance matters, vm86
1192	  mode might be faster than emulation and you might want to
1193	  enable this option.
1194
1195	  Note that any app that works on a 64-bit kernel is unlikely to
1196	  need this option, as 64-bit kernels don't, and can't, support
1197	  V8086 mode. This option is also unrelated to 16-bit protected
1198	  mode and is not needed to run most 16-bit programs under Wine.
1199
1200	  Enabling this option increases the complexity of the kernel
1201	  and slows down exception handling a tiny bit.
1202
1203	  If unsure, say N here.
1204
1205config VM86
1206       bool
1207       default X86_LEGACY_VM86
1208
1209config X86_16BIT
1210	bool "Enable support for 16-bit segments" if EXPERT
1211	default y
1212	depends on MODIFY_LDT_SYSCALL
1213	---help---
1214	  This option is required by programs like Wine to run 16-bit
1215	  protected mode legacy code on x86 processors.  Disabling
1216	  this option saves about 300 bytes on i386, or around 6K text
1217	  plus 16K runtime memory on x86-64,
1218
1219config X86_ESPFIX32
1220	def_bool y
1221	depends on X86_16BIT && X86_32
1222
1223config X86_ESPFIX64
1224	def_bool y
1225	depends on X86_16BIT && X86_64
1226
1227config X86_VSYSCALL_EMULATION
1228       bool "Enable vsyscall emulation" if EXPERT
1229       default y
1230       depends on X86_64
1231       ---help---
1232	 This enables emulation of the legacy vsyscall page.  Disabling
1233	 it is roughly equivalent to booting with vsyscall=none, except
1234	 that it will also disable the helpful warning if a program
1235	 tries to use a vsyscall.  With this option set to N, offending
1236	 programs will just segfault, citing addresses of the form
1237	 0xffffffffff600?00.
1238
1239	 This option is required by many programs built before 2013, and
1240	 care should be used even with newer programs if set to N.
1241
1242	 Disabling this option saves about 7K of kernel size and
1243	 possibly 4K of additional runtime pagetable memory.
1244
1245config TOSHIBA
1246	tristate "Toshiba Laptop support"
1247	depends on X86_32
1248	---help---
1249	  This adds a driver to safely access the System Management Mode of
1250	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1251	  not work on models with a Phoenix BIOS. The System Management Mode
1252	  is used to set the BIOS and power saving options on Toshiba portables.
1253
1254	  For information on utilities to make use of this driver see the
1255	  Toshiba Linux utilities web site at:
1256	  <http://www.buzzard.org.uk/toshiba/>.
1257
1258	  Say Y if you intend to run this kernel on a Toshiba portable.
1259	  Say N otherwise.
1260
1261config I8K
1262	tristate "Dell i8k legacy laptop support"
1263	select HWMON
1264	select SENSORS_DELL_SMM
1265	---help---
1266	  This option enables legacy /proc/i8k userspace interface in hwmon
1267	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1268	  temperature and allows controlling fan speeds of Dell laptops via
1269	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1270	  it reports also power and hotkey status. For fan speed control is
1271	  needed userspace package i8kutils.
1272
1273	  Say Y if you intend to run this kernel on old Dell laptops or want to
1274	  use userspace package i8kutils.
1275	  Say N otherwise.
1276
1277config X86_REBOOTFIXUPS
1278	bool "Enable X86 board specific fixups for reboot"
1279	depends on X86_32
1280	---help---
1281	  This enables chipset and/or board specific fixups to be done
1282	  in order to get reboot to work correctly. This is only needed on
1283	  some combinations of hardware and BIOS. The symptom, for which
1284	  this config is intended, is when reboot ends with a stalled/hung
1285	  system.
1286
1287	  Currently, the only fixup is for the Geode machines using
1288	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1289
1290	  Say Y if you want to enable the fixup. Currently, it's safe to
1291	  enable this option even if you don't need it.
1292	  Say N otherwise.
1293
1294config MICROCODE
1295	bool "CPU microcode loading support"
1296	default y
1297	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1298	select FW_LOADER
1299	---help---
1300	  If you say Y here, you will be able to update the microcode on
1301	  Intel and AMD processors. The Intel support is for the IA32 family,
1302	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1303	  AMD support is for families 0x10 and later. You will obviously need
1304	  the actual microcode binary data itself which is not shipped with
1305	  the Linux kernel.
1306
1307	  The preferred method to load microcode from a detached initrd is described
1308	  in Documentation/x86/early-microcode.txt. For that you need to enable
1309	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1310	  initrd for microcode blobs.
1311
1312	  In addition, you can build the microcode into the kernel. For that you
1313	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1314	  config option.
1315
1316config MICROCODE_INTEL
1317	bool "Intel microcode loading support"
1318	depends on MICROCODE
1319	default MICROCODE
1320	select FW_LOADER
1321	---help---
1322	  This options enables microcode patch loading support for Intel
1323	  processors.
1324
1325	  For the current Intel microcode data package go to
1326	  <https://downloadcenter.intel.com> and search for
1327	  'Linux Processor Microcode Data File'.
1328
1329config MICROCODE_AMD
1330	bool "AMD microcode loading support"
1331	depends on MICROCODE
1332	select FW_LOADER
1333	---help---
1334	  If you select this option, microcode patch loading support for AMD
1335	  processors will be enabled.
1336
1337config MICROCODE_OLD_INTERFACE
1338	def_bool y
1339	depends on MICROCODE
1340
1341config X86_MSR
1342	tristate "/dev/cpu/*/msr - Model-specific register support"
1343	---help---
1344	  This device gives privileged processes access to the x86
1345	  Model-Specific Registers (MSRs).  It is a character device with
1346	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1347	  MSR accesses are directed to a specific CPU on multi-processor
1348	  systems.
1349
1350config X86_CPUID
1351	tristate "/dev/cpu/*/cpuid - CPU information support"
1352	---help---
1353	  This device gives processes access to the x86 CPUID instruction to
1354	  be executed on a specific processor.  It is a character device
1355	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1356	  /dev/cpu/31/cpuid.
1357
1358choice
1359	prompt "High Memory Support"
1360	default HIGHMEM4G
1361	depends on X86_32
1362
1363config NOHIGHMEM
1364	bool "off"
1365	---help---
1366	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1367	  However, the address space of 32-bit x86 processors is only 4
1368	  Gigabytes large. That means that, if you have a large amount of
1369	  physical memory, not all of it can be "permanently mapped" by the
1370	  kernel. The physical memory that's not permanently mapped is called
1371	  "high memory".
1372
1373	  If you are compiling a kernel which will never run on a machine with
1374	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1375	  choice and suitable for most users). This will result in a "3GB/1GB"
1376	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1377	  space and the remaining part of the 4GB virtual memory space is used
1378	  by the kernel to permanently map as much physical memory as
1379	  possible.
1380
1381	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1382	  answer "4GB" here.
1383
1384	  If more than 4 Gigabytes is used then answer "64GB" here. This
1385	  selection turns Intel PAE (Physical Address Extension) mode on.
1386	  PAE implements 3-level paging on IA32 processors. PAE is fully
1387	  supported by Linux, PAE mode is implemented on all recent Intel
1388	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1389	  then the kernel will not boot on CPUs that don't support PAE!
1390
1391	  The actual amount of total physical memory will either be
1392	  auto detected or can be forced by using a kernel command line option
1393	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1394	  your boot loader (lilo or loadlin) about how to pass options to the
1395	  kernel at boot time.)
1396
1397	  If unsure, say "off".
1398
1399config HIGHMEM4G
1400	bool "4GB"
1401	---help---
1402	  Select this if you have a 32-bit processor and between 1 and 4
1403	  gigabytes of physical RAM.
1404
1405config HIGHMEM64G
1406	bool "64GB"
1407	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1408	select X86_PAE
1409	---help---
1410	  Select this if you have a 32-bit processor and more than 4
1411	  gigabytes of physical RAM.
1412
1413endchoice
1414
1415choice
1416	prompt "Memory split" if EXPERT
1417	default VMSPLIT_3G
1418	depends on X86_32
1419	---help---
1420	  Select the desired split between kernel and user memory.
1421
1422	  If the address range available to the kernel is less than the
1423	  physical memory installed, the remaining memory will be available
1424	  as "high memory". Accessing high memory is a little more costly
1425	  than low memory, as it needs to be mapped into the kernel first.
1426	  Note that increasing the kernel address space limits the range
1427	  available to user programs, making the address space there
1428	  tighter.  Selecting anything other than the default 3G/1G split
1429	  will also likely make your kernel incompatible with binary-only
1430	  kernel modules.
1431
1432	  If you are not absolutely sure what you are doing, leave this
1433	  option alone!
1434
1435	config VMSPLIT_3G
1436		bool "3G/1G user/kernel split"
1437	config VMSPLIT_3G_OPT
1438		depends on !X86_PAE
1439		bool "3G/1G user/kernel split (for full 1G low memory)"
1440	config VMSPLIT_2G
1441		bool "2G/2G user/kernel split"
1442	config VMSPLIT_2G_OPT
1443		depends on !X86_PAE
1444		bool "2G/2G user/kernel split (for full 2G low memory)"
1445	config VMSPLIT_1G
1446		bool "1G/3G user/kernel split"
1447endchoice
1448
1449config PAGE_OFFSET
1450	hex
1451	default 0xB0000000 if VMSPLIT_3G_OPT
1452	default 0x80000000 if VMSPLIT_2G
1453	default 0x78000000 if VMSPLIT_2G_OPT
1454	default 0x40000000 if VMSPLIT_1G
1455	default 0xC0000000
1456	depends on X86_32
1457
1458config HIGHMEM
1459	def_bool y
1460	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1461
1462config X86_PAE
1463	bool "PAE (Physical Address Extension) Support"
1464	depends on X86_32 && !HIGHMEM4G
1465	select SWIOTLB
1466	---help---
1467	  PAE is required for NX support, and furthermore enables
1468	  larger swapspace support for non-overcommit purposes. It
1469	  has the cost of more pagetable lookup overhead, and also
1470	  consumes more pagetable space per process.
1471
1472config X86_5LEVEL
1473	bool "Enable 5-level page tables support"
1474	depends on X86_64
1475	---help---
1476	  5-level paging enables access to larger address space:
1477	  upto 128 PiB of virtual address space and 4 PiB of
1478	  physical address space.
1479
1480	  It will be supported by future Intel CPUs.
1481
1482	  Note: a kernel with this option enabled can only be booted
1483	  on machines that support the feature.
1484
1485	  See Documentation/x86/x86_64/5level-paging.txt for more
1486	  information.
1487
1488	  Say N if unsure.
1489
1490config ARCH_PHYS_ADDR_T_64BIT
1491	def_bool y
1492	depends on X86_64 || X86_PAE
1493
1494config ARCH_DMA_ADDR_T_64BIT
1495	def_bool y
1496	depends on X86_64 || HIGHMEM64G
1497
1498config X86_DIRECT_GBPAGES
1499	def_bool y
1500	depends on X86_64 && !DEBUG_PAGEALLOC
1501	---help---
1502	  Certain kernel features effectively disable kernel
1503	  linear 1 GB mappings (even if the CPU otherwise
1504	  supports them), so don't confuse the user by printing
1505	  that we have them enabled.
1506
1507config ARCH_HAS_MEM_ENCRYPT
1508	def_bool y
1509
1510config AMD_MEM_ENCRYPT
1511	bool "AMD Secure Memory Encryption (SME) support"
1512	depends on X86_64 && CPU_SUP_AMD
1513	---help---
1514	  Say yes to enable support for the encryption of system memory.
1515	  This requires an AMD processor that supports Secure Memory
1516	  Encryption (SME).
1517
1518config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1519	bool "Activate AMD Secure Memory Encryption (SME) by default"
1520	default y
1521	depends on AMD_MEM_ENCRYPT
1522	---help---
1523	  Say yes to have system memory encrypted by default if running on
1524	  an AMD processor that supports Secure Memory Encryption (SME).
1525
1526	  If set to Y, then the encryption of system memory can be
1527	  deactivated with the mem_encrypt=off command line option.
1528
1529	  If set to N, then the encryption of system memory can be
1530	  activated with the mem_encrypt=on command line option.
1531
1532config ARCH_USE_MEMREMAP_PROT
1533	def_bool y
1534	depends on AMD_MEM_ENCRYPT
1535
1536# Common NUMA Features
1537config NUMA
1538	bool "Numa Memory Allocation and Scheduler Support"
1539	depends on SMP
1540	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1541	default y if X86_BIGSMP
1542	---help---
1543	  Enable NUMA (Non Uniform Memory Access) support.
1544
1545	  The kernel will try to allocate memory used by a CPU on the
1546	  local memory controller of the CPU and add some more
1547	  NUMA awareness to the kernel.
1548
1549	  For 64-bit this is recommended if the system is Intel Core i7
1550	  (or later), AMD Opteron, or EM64T NUMA.
1551
1552	  For 32-bit this is only needed if you boot a 32-bit
1553	  kernel on a 64-bit NUMA platform.
1554
1555	  Otherwise, you should say N.
1556
1557config AMD_NUMA
1558	def_bool y
1559	prompt "Old style AMD Opteron NUMA detection"
1560	depends on X86_64 && NUMA && PCI
1561	---help---
1562	  Enable AMD NUMA node topology detection.  You should say Y here if
1563	  you have a multi processor AMD system. This uses an old method to
1564	  read the NUMA configuration directly from the builtin Northbridge
1565	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1566	  which also takes priority if both are compiled in.
1567
1568config X86_64_ACPI_NUMA
1569	def_bool y
1570	prompt "ACPI NUMA detection"
1571	depends on X86_64 && NUMA && ACPI && PCI
1572	select ACPI_NUMA
1573	---help---
1574	  Enable ACPI SRAT based node topology detection.
1575
1576# Some NUMA nodes have memory ranges that span
1577# other nodes.  Even though a pfn is valid and
1578# between a node's start and end pfns, it may not
1579# reside on that node.  See memmap_init_zone()
1580# for details.
1581config NODES_SPAN_OTHER_NODES
1582	def_bool y
1583	depends on X86_64_ACPI_NUMA
1584
1585config NUMA_EMU
1586	bool "NUMA emulation"
1587	depends on NUMA
1588	---help---
1589	  Enable NUMA emulation. A flat machine will be split
1590	  into virtual nodes when booted with "numa=fake=N", where N is the
1591	  number of nodes. This is only useful for debugging.
1592
1593config NODES_SHIFT
1594	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1595	range 1 10
1596	default "10" if MAXSMP
1597	default "6" if X86_64
1598	default "3"
1599	depends on NEED_MULTIPLE_NODES
1600	---help---
1601	  Specify the maximum number of NUMA Nodes available on the target
1602	  system.  Increases memory reserved to accommodate various tables.
1603
1604config ARCH_HAVE_MEMORY_PRESENT
1605	def_bool y
1606	depends on X86_32 && DISCONTIGMEM
1607
1608config NEED_NODE_MEMMAP_SIZE
1609	def_bool y
1610	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1611
1612config ARCH_FLATMEM_ENABLE
1613	def_bool y
1614	depends on X86_32 && !NUMA
1615
1616config ARCH_DISCONTIGMEM_ENABLE
1617	def_bool y
1618	depends on NUMA && X86_32
1619
1620config ARCH_DISCONTIGMEM_DEFAULT
1621	def_bool y
1622	depends on NUMA && X86_32
1623
1624config ARCH_SPARSEMEM_ENABLE
1625	def_bool y
1626	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1627	select SPARSEMEM_STATIC if X86_32
1628	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1629
1630config ARCH_SPARSEMEM_DEFAULT
1631	def_bool y
1632	depends on X86_64
1633
1634config ARCH_SELECT_MEMORY_MODEL
1635	def_bool y
1636	depends on ARCH_SPARSEMEM_ENABLE
1637
1638config ARCH_MEMORY_PROBE
1639	bool "Enable sysfs memory/probe interface"
1640	depends on X86_64 && MEMORY_HOTPLUG
1641	help
1642	  This option enables a sysfs memory/probe interface for testing.
1643	  See Documentation/memory-hotplug.txt for more information.
1644	  If you are unsure how to answer this question, answer N.
1645
1646config ARCH_PROC_KCORE_TEXT
1647	def_bool y
1648	depends on X86_64 && PROC_KCORE
1649
1650config ILLEGAL_POINTER_VALUE
1651       hex
1652       default 0 if X86_32
1653       default 0xdead000000000000 if X86_64
1654
1655source "mm/Kconfig"
1656
1657config X86_PMEM_LEGACY_DEVICE
1658	bool
1659
1660config X86_PMEM_LEGACY
1661	tristate "Support non-standard NVDIMMs and ADR protected memory"
1662	depends on PHYS_ADDR_T_64BIT
1663	depends on BLK_DEV
1664	select X86_PMEM_LEGACY_DEVICE
1665	select LIBNVDIMM
1666	help
1667	  Treat memory marked using the non-standard e820 type of 12 as used
1668	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1669	  The kernel will offer these regions to the 'pmem' driver so
1670	  they can be used for persistent storage.
1671
1672	  Say Y if unsure.
1673
1674config HIGHPTE
1675	bool "Allocate 3rd-level pagetables from highmem"
1676	depends on HIGHMEM
1677	---help---
1678	  The VM uses one page table entry for each page of physical memory.
1679	  For systems with a lot of RAM, this can be wasteful of precious
1680	  low memory.  Setting this option will put user-space page table
1681	  entries in high memory.
1682
1683config X86_CHECK_BIOS_CORRUPTION
1684	bool "Check for low memory corruption"
1685	---help---
1686	  Periodically check for memory corruption in low memory, which
1687	  is suspected to be caused by BIOS.  Even when enabled in the
1688	  configuration, it is disabled at runtime.  Enable it by
1689	  setting "memory_corruption_check=1" on the kernel command
1690	  line.  By default it scans the low 64k of memory every 60
1691	  seconds; see the memory_corruption_check_size and
1692	  memory_corruption_check_period parameters in
1693	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1694
1695	  When enabled with the default parameters, this option has
1696	  almost no overhead, as it reserves a relatively small amount
1697	  of memory and scans it infrequently.  It both detects corruption
1698	  and prevents it from affecting the running system.
1699
1700	  It is, however, intended as a diagnostic tool; if repeatable
1701	  BIOS-originated corruption always affects the same memory,
1702	  you can use memmap= to prevent the kernel from using that
1703	  memory.
1704
1705config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1706	bool "Set the default setting of memory_corruption_check"
1707	depends on X86_CHECK_BIOS_CORRUPTION
1708	default y
1709	---help---
1710	  Set whether the default state of memory_corruption_check is
1711	  on or off.
1712
1713config X86_RESERVE_LOW
1714	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1715	default 64
1716	range 4 640
1717	---help---
1718	  Specify the amount of low memory to reserve for the BIOS.
1719
1720	  The first page contains BIOS data structures that the kernel
1721	  must not use, so that page must always be reserved.
1722
1723	  By default we reserve the first 64K of physical RAM, as a
1724	  number of BIOSes are known to corrupt that memory range
1725	  during events such as suspend/resume or monitor cable
1726	  insertion, so it must not be used by the kernel.
1727
1728	  You can set this to 4 if you are absolutely sure that you
1729	  trust the BIOS to get all its memory reservations and usages
1730	  right.  If you know your BIOS have problems beyond the
1731	  default 64K area, you can set this to 640 to avoid using the
1732	  entire low memory range.
1733
1734	  If you have doubts about the BIOS (e.g. suspend/resume does
1735	  not work or there's kernel crashes after certain hardware
1736	  hotplug events) then you might want to enable
1737	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1738	  typical corruption patterns.
1739
1740	  Leave this to the default value of 64 if you are unsure.
1741
1742config MATH_EMULATION
1743	bool
1744	depends on MODIFY_LDT_SYSCALL
1745	prompt "Math emulation" if X86_32
1746	---help---
1747	  Linux can emulate a math coprocessor (used for floating point
1748	  operations) if you don't have one. 486DX and Pentium processors have
1749	  a math coprocessor built in, 486SX and 386 do not, unless you added
1750	  a 487DX or 387, respectively. (The messages during boot time can
1751	  give you some hints here ["man dmesg"].) Everyone needs either a
1752	  coprocessor or this emulation.
1753
1754	  If you don't have a math coprocessor, you need to say Y here; if you
1755	  say Y here even though you have a coprocessor, the coprocessor will
1756	  be used nevertheless. (This behavior can be changed with the kernel
1757	  command line option "no387", which comes handy if your coprocessor
1758	  is broken. Try "man bootparam" or see the documentation of your boot
1759	  loader (lilo or loadlin) about how to pass options to the kernel at
1760	  boot time.) This means that it is a good idea to say Y here if you
1761	  intend to use this kernel on different machines.
1762
1763	  More information about the internals of the Linux math coprocessor
1764	  emulation can be found in <file:arch/x86/math-emu/README>.
1765
1766	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1767	  kernel, it won't hurt.
1768
1769config MTRR
1770	def_bool y
1771	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1772	---help---
1773	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1774	  the Memory Type Range Registers (MTRRs) may be used to control
1775	  processor access to memory ranges. This is most useful if you have
1776	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1777	  allows bus write transfers to be combined into a larger transfer
1778	  before bursting over the PCI/AGP bus. This can increase performance
1779	  of image write operations 2.5 times or more. Saying Y here creates a
1780	  /proc/mtrr file which may be used to manipulate your processor's
1781	  MTRRs. Typically the X server should use this.
1782
1783	  This code has a reasonably generic interface so that similar
1784	  control registers on other processors can be easily supported
1785	  as well:
1786
1787	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1788	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1789	  these, the ARRs are used to emulate the MTRRs.
1790	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1791	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1792	  write-combining. All of these processors are supported by this code
1793	  and it makes sense to say Y here if you have one of them.
1794
1795	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1796	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1797	  can lead to all sorts of problems, so it's good to say Y here.
1798
1799	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1800	  just add about 9 KB to your kernel.
1801
1802	  See <file:Documentation/x86/mtrr.txt> for more information.
1803
1804config MTRR_SANITIZER
1805	def_bool y
1806	prompt "MTRR cleanup support"
1807	depends on MTRR
1808	---help---
1809	  Convert MTRR layout from continuous to discrete, so X drivers can
1810	  add writeback entries.
1811
1812	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1813	  The largest mtrr entry size for a continuous block can be set with
1814	  mtrr_chunk_size.
1815
1816	  If unsure, say Y.
1817
1818config MTRR_SANITIZER_ENABLE_DEFAULT
1819	int "MTRR cleanup enable value (0-1)"
1820	range 0 1
1821	default "0"
1822	depends on MTRR_SANITIZER
1823	---help---
1824	  Enable mtrr cleanup default value
1825
1826config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1827	int "MTRR cleanup spare reg num (0-7)"
1828	range 0 7
1829	default "1"
1830	depends on MTRR_SANITIZER
1831	---help---
1832	  mtrr cleanup spare entries default, it can be changed via
1833	  mtrr_spare_reg_nr=N on the kernel command line.
1834
1835config X86_PAT
1836	def_bool y
1837	prompt "x86 PAT support" if EXPERT
1838	depends on MTRR
1839	---help---
1840	  Use PAT attributes to setup page level cache control.
1841
1842	  PATs are the modern equivalents of MTRRs and are much more
1843	  flexible than MTRRs.
1844
1845	  Say N here if you see bootup problems (boot crash, boot hang,
1846	  spontaneous reboots) or a non-working video driver.
1847
1848	  If unsure, say Y.
1849
1850config ARCH_USES_PG_UNCACHED
1851	def_bool y
1852	depends on X86_PAT
1853
1854config ARCH_RANDOM
1855	def_bool y
1856	prompt "x86 architectural random number generator" if EXPERT
1857	---help---
1858	  Enable the x86 architectural RDRAND instruction
1859	  (Intel Bull Mountain technology) to generate random numbers.
1860	  If supported, this is a high bandwidth, cryptographically
1861	  secure hardware random number generator.
1862
1863config X86_SMAP
1864	def_bool y
1865	prompt "Supervisor Mode Access Prevention" if EXPERT
1866	---help---
1867	  Supervisor Mode Access Prevention (SMAP) is a security
1868	  feature in newer Intel processors.  There is a small
1869	  performance cost if this enabled and turned on; there is
1870	  also a small increase in the kernel size if this is enabled.
1871
1872	  If unsure, say Y.
1873
1874config X86_INTEL_UMIP
1875	def_bool y
1876	depends on CPU_SUP_INTEL
1877	prompt "Intel User Mode Instruction Prevention" if EXPERT
1878	---help---
1879	  The User Mode Instruction Prevention (UMIP) is a security
1880	  feature in newer Intel processors. If enabled, a general
1881	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1882	  or STR instructions are executed in user mode. These instructions
1883	  unnecessarily expose information about the hardware state.
1884
1885	  The vast majority of applications do not use these instructions.
1886	  For the very few that do, software emulation is provided in
1887	  specific cases in protected and virtual-8086 modes. Emulated
1888	  results are dummy.
1889
1890config X86_INTEL_MPX
1891	prompt "Intel MPX (Memory Protection Extensions)"
1892	def_bool n
1893	# Note: only available in 64-bit mode due to VMA flags shortage
1894	depends on CPU_SUP_INTEL && X86_64
1895	select ARCH_USES_HIGH_VMA_FLAGS
1896	---help---
1897	  MPX provides hardware features that can be used in
1898	  conjunction with compiler-instrumented code to check
1899	  memory references.  It is designed to detect buffer
1900	  overflow or underflow bugs.
1901
1902	  This option enables running applications which are
1903	  instrumented or otherwise use MPX.  It does not use MPX
1904	  itself inside the kernel or to protect the kernel
1905	  against bad memory references.
1906
1907	  Enabling this option will make the kernel larger:
1908	  ~8k of kernel text and 36 bytes of data on a 64-bit
1909	  defconfig.  It adds a long to the 'mm_struct' which
1910	  will increase the kernel memory overhead of each
1911	  process and adds some branches to paths used during
1912	  exec() and munmap().
1913
1914	  For details, see Documentation/x86/intel_mpx.txt
1915
1916	  If unsure, say N.
1917
1918config X86_INTEL_MEMORY_PROTECTION_KEYS
1919	prompt "Intel Memory Protection Keys"
1920	def_bool y
1921	# Note: only available in 64-bit mode
1922	depends on CPU_SUP_INTEL && X86_64
1923	select ARCH_USES_HIGH_VMA_FLAGS
1924	select ARCH_HAS_PKEYS
1925	---help---
1926	  Memory Protection Keys provides a mechanism for enforcing
1927	  page-based protections, but without requiring modification of the
1928	  page tables when an application changes protection domains.
1929
1930	  For details, see Documentation/x86/protection-keys.txt
1931
1932	  If unsure, say y.
1933
1934config EFI
1935	bool "EFI runtime service support"
1936	depends on ACPI
1937	select UCS2_STRING
1938	select EFI_RUNTIME_WRAPPERS
1939	---help---
1940	  This enables the kernel to use EFI runtime services that are
1941	  available (such as the EFI variable services).
1942
1943	  This option is only useful on systems that have EFI firmware.
1944	  In addition, you should use the latest ELILO loader available
1945	  at <http://elilo.sourceforge.net> in order to take advantage
1946	  of EFI runtime services. However, even with this option, the
1947	  resultant kernel should continue to boot on existing non-EFI
1948	  platforms.
1949
1950config EFI_STUB
1951       bool "EFI stub support"
1952       depends on EFI && !X86_USE_3DNOW
1953       select RELOCATABLE
1954       ---help---
1955          This kernel feature allows a bzImage to be loaded directly
1956	  by EFI firmware without the use of a bootloader.
1957
1958	  See Documentation/efi-stub.txt for more information.
1959
1960config EFI_MIXED
1961	bool "EFI mixed-mode support"
1962	depends on EFI_STUB && X86_64
1963	---help---
1964	   Enabling this feature allows a 64-bit kernel to be booted
1965	   on a 32-bit firmware, provided that your CPU supports 64-bit
1966	   mode.
1967
1968	   Note that it is not possible to boot a mixed-mode enabled
1969	   kernel via the EFI boot stub - a bootloader that supports
1970	   the EFI handover protocol must be used.
1971
1972	   If unsure, say N.
1973
1974config SECCOMP
1975	def_bool y
1976	prompt "Enable seccomp to safely compute untrusted bytecode"
1977	---help---
1978	  This kernel feature is useful for number crunching applications
1979	  that may need to compute untrusted bytecode during their
1980	  execution. By using pipes or other transports made available to
1981	  the process as file descriptors supporting the read/write
1982	  syscalls, it's possible to isolate those applications in
1983	  their own address space using seccomp. Once seccomp is
1984	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1985	  and the task is only allowed to execute a few safe syscalls
1986	  defined by each seccomp mode.
1987
1988	  If unsure, say Y. Only embedded should say N here.
1989
1990source kernel/Kconfig.hz
1991
1992config KEXEC
1993	bool "kexec system call"
1994	select KEXEC_CORE
1995	---help---
1996	  kexec is a system call that implements the ability to shutdown your
1997	  current kernel, and to start another kernel.  It is like a reboot
1998	  but it is independent of the system firmware.   And like a reboot
1999	  you can start any kernel with it, not just Linux.
2000
2001	  The name comes from the similarity to the exec system call.
2002
2003	  It is an ongoing process to be certain the hardware in a machine
2004	  is properly shutdown, so do not be surprised if this code does not
2005	  initially work for you.  As of this writing the exact hardware
2006	  interface is strongly in flux, so no good recommendation can be
2007	  made.
2008
2009config KEXEC_FILE
2010	bool "kexec file based system call"
2011	select KEXEC_CORE
2012	select BUILD_BIN2C
2013	depends on X86_64
2014	depends on CRYPTO=y
2015	depends on CRYPTO_SHA256=y
2016	---help---
2017	  This is new version of kexec system call. This system call is
2018	  file based and takes file descriptors as system call argument
2019	  for kernel and initramfs as opposed to list of segments as
2020	  accepted by previous system call.
2021
2022config KEXEC_VERIFY_SIG
2023	bool "Verify kernel signature during kexec_file_load() syscall"
2024	depends on KEXEC_FILE
2025	---help---
2026	  This option makes kernel signature verification mandatory for
2027	  the kexec_file_load() syscall.
2028
2029	  In addition to that option, you need to enable signature
2030	  verification for the corresponding kernel image type being
2031	  loaded in order for this to work.
2032
2033config KEXEC_BZIMAGE_VERIFY_SIG
2034	bool "Enable bzImage signature verification support"
2035	depends on KEXEC_VERIFY_SIG
2036	depends on SIGNED_PE_FILE_VERIFICATION
2037	select SYSTEM_TRUSTED_KEYRING
2038	---help---
2039	  Enable bzImage signature verification support.
2040
2041config CRASH_DUMP
2042	bool "kernel crash dumps"
2043	depends on X86_64 || (X86_32 && HIGHMEM)
2044	---help---
2045	  Generate crash dump after being started by kexec.
2046	  This should be normally only set in special crash dump kernels
2047	  which are loaded in the main kernel with kexec-tools into
2048	  a specially reserved region and then later executed after
2049	  a crash by kdump/kexec. The crash dump kernel must be compiled
2050	  to a memory address not used by the main kernel or BIOS using
2051	  PHYSICAL_START, or it must be built as a relocatable image
2052	  (CONFIG_RELOCATABLE=y).
2053	  For more details see Documentation/kdump/kdump.txt
2054
2055config KEXEC_JUMP
2056	bool "kexec jump"
2057	depends on KEXEC && HIBERNATION
2058	---help---
2059	  Jump between original kernel and kexeced kernel and invoke
2060	  code in physical address mode via KEXEC
2061
2062config PHYSICAL_START
2063	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2064	default "0x1000000"
2065	---help---
2066	  This gives the physical address where the kernel is loaded.
2067
2068	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2069	  bzImage will decompress itself to above physical address and
2070	  run from there. Otherwise, bzImage will run from the address where
2071	  it has been loaded by the boot loader and will ignore above physical
2072	  address.
2073
2074	  In normal kdump cases one does not have to set/change this option
2075	  as now bzImage can be compiled as a completely relocatable image
2076	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2077	  address. This option is mainly useful for the folks who don't want
2078	  to use a bzImage for capturing the crash dump and want to use a
2079	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2080	  to be specifically compiled to run from a specific memory area
2081	  (normally a reserved region) and this option comes handy.
2082
2083	  So if you are using bzImage for capturing the crash dump,
2084	  leave the value here unchanged to 0x1000000 and set
2085	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2086	  for capturing the crash dump change this value to start of
2087	  the reserved region.  In other words, it can be set based on
2088	  the "X" value as specified in the "crashkernel=YM@XM"
2089	  command line boot parameter passed to the panic-ed
2090	  kernel. Please take a look at Documentation/kdump/kdump.txt
2091	  for more details about crash dumps.
2092
2093	  Usage of bzImage for capturing the crash dump is recommended as
2094	  one does not have to build two kernels. Same kernel can be used
2095	  as production kernel and capture kernel. Above option should have
2096	  gone away after relocatable bzImage support is introduced. But it
2097	  is present because there are users out there who continue to use
2098	  vmlinux for dump capture. This option should go away down the
2099	  line.
2100
2101	  Don't change this unless you know what you are doing.
2102
2103config RELOCATABLE
2104	bool "Build a relocatable kernel"
2105	default y
2106	---help---
2107	  This builds a kernel image that retains relocation information
2108	  so it can be loaded someplace besides the default 1MB.
2109	  The relocations tend to make the kernel binary about 10% larger,
2110	  but are discarded at runtime.
2111
2112	  One use is for the kexec on panic case where the recovery kernel
2113	  must live at a different physical address than the primary
2114	  kernel.
2115
2116	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2117	  it has been loaded at and the compile time physical address
2118	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2119
2120config RANDOMIZE_BASE
2121	bool "Randomize the address of the kernel image (KASLR)"
2122	depends on RELOCATABLE
2123	default y
2124	---help---
2125	  In support of Kernel Address Space Layout Randomization (KASLR),
2126	  this randomizes the physical address at which the kernel image
2127	  is decompressed and the virtual address where the kernel
2128	  image is mapped, as a security feature that deters exploit
2129	  attempts relying on knowledge of the location of kernel
2130	  code internals.
2131
2132	  On 64-bit, the kernel physical and virtual addresses are
2133	  randomized separately. The physical address will be anywhere
2134	  between 16MB and the top of physical memory (up to 64TB). The
2135	  virtual address will be randomized from 16MB up to 1GB (9 bits
2136	  of entropy). Note that this also reduces the memory space
2137	  available to kernel modules from 1.5GB to 1GB.
2138
2139	  On 32-bit, the kernel physical and virtual addresses are
2140	  randomized together. They will be randomized from 16MB up to
2141	  512MB (8 bits of entropy).
2142
2143	  Entropy is generated using the RDRAND instruction if it is
2144	  supported. If RDTSC is supported, its value is mixed into
2145	  the entropy pool as well. If neither RDRAND nor RDTSC are
2146	  supported, then entropy is read from the i8254 timer. The
2147	  usable entropy is limited by the kernel being built using
2148	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2149	  minimum of 2MB. As a result, only 10 bits of entropy are
2150	  theoretically possible, but the implementations are further
2151	  limited due to memory layouts.
2152
2153	  If unsure, say Y.
2154
2155# Relocation on x86 needs some additional build support
2156config X86_NEED_RELOCS
2157	def_bool y
2158	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2159
2160config PHYSICAL_ALIGN
2161	hex "Alignment value to which kernel should be aligned"
2162	default "0x200000"
2163	range 0x2000 0x1000000 if X86_32
2164	range 0x200000 0x1000000 if X86_64
2165	---help---
2166	  This value puts the alignment restrictions on physical address
2167	  where kernel is loaded and run from. Kernel is compiled for an
2168	  address which meets above alignment restriction.
2169
2170	  If bootloader loads the kernel at a non-aligned address and
2171	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2172	  address aligned to above value and run from there.
2173
2174	  If bootloader loads the kernel at a non-aligned address and
2175	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2176	  load address and decompress itself to the address it has been
2177	  compiled for and run from there. The address for which kernel is
2178	  compiled already meets above alignment restrictions. Hence the
2179	  end result is that kernel runs from a physical address meeting
2180	  above alignment restrictions.
2181
2182	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2183	  this value must be a multiple of 0x200000.
2184
2185	  Don't change this unless you know what you are doing.
2186
2187config RANDOMIZE_MEMORY
2188	bool "Randomize the kernel memory sections"
2189	depends on X86_64
2190	depends on RANDOMIZE_BASE
2191	default RANDOMIZE_BASE
2192	---help---
2193	   Randomizes the base virtual address of kernel memory sections
2194	   (physical memory mapping, vmalloc & vmemmap). This security feature
2195	   makes exploits relying on predictable memory locations less reliable.
2196
2197	   The order of allocations remains unchanged. Entropy is generated in
2198	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2199	   configuration have in average 30,000 different possible virtual
2200	   addresses for each memory section.
2201
2202	   If unsure, say Y.
2203
2204config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2205	hex "Physical memory mapping padding" if EXPERT
2206	depends on RANDOMIZE_MEMORY
2207	default "0xa" if MEMORY_HOTPLUG
2208	default "0x0"
2209	range 0x1 0x40 if MEMORY_HOTPLUG
2210	range 0x0 0x40
2211	---help---
2212	   Define the padding in terabytes added to the existing physical
2213	   memory size during kernel memory randomization. It is useful
2214	   for memory hotplug support but reduces the entropy available for
2215	   address randomization.
2216
2217	   If unsure, leave at the default value.
2218
2219config HOTPLUG_CPU
2220	bool "Support for hot-pluggable CPUs"
2221	depends on SMP
2222	---help---
2223	  Say Y here to allow turning CPUs off and on. CPUs can be
2224	  controlled through /sys/devices/system/cpu.
2225	  ( Note: power management support will enable this option
2226	    automatically on SMP systems. )
2227	  Say N if you want to disable CPU hotplug.
2228
2229config BOOTPARAM_HOTPLUG_CPU0
2230	bool "Set default setting of cpu0_hotpluggable"
2231	default n
2232	depends on HOTPLUG_CPU
2233	---help---
2234	  Set whether default state of cpu0_hotpluggable is on or off.
2235
2236	  Say Y here to enable CPU0 hotplug by default. If this switch
2237	  is turned on, there is no need to give cpu0_hotplug kernel
2238	  parameter and the CPU0 hotplug feature is enabled by default.
2239
2240	  Please note: there are two known CPU0 dependencies if you want
2241	  to enable the CPU0 hotplug feature either by this switch or by
2242	  cpu0_hotplug kernel parameter.
2243
2244	  First, resume from hibernate or suspend always starts from CPU0.
2245	  So hibernate and suspend are prevented if CPU0 is offline.
2246
2247	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2248	  offline if any interrupt can not migrate out of CPU0. There may
2249	  be other CPU0 dependencies.
2250
2251	  Please make sure the dependencies are under your control before
2252	  you enable this feature.
2253
2254	  Say N if you don't want to enable CPU0 hotplug feature by default.
2255	  You still can enable the CPU0 hotplug feature at boot by kernel
2256	  parameter cpu0_hotplug.
2257
2258config DEBUG_HOTPLUG_CPU0
2259	def_bool n
2260	prompt "Debug CPU0 hotplug"
2261	depends on HOTPLUG_CPU
2262	---help---
2263	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2264	  soon as possible and boots up userspace with CPU0 offlined. User
2265	  can online CPU0 back after boot time.
2266
2267	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2268	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2269	  compilation or giving cpu0_hotplug kernel parameter at boot.
2270
2271	  If unsure, say N.
2272
2273config COMPAT_VDSO
2274	def_bool n
2275	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2276	depends on COMPAT_32
2277	---help---
2278	  Certain buggy versions of glibc will crash if they are
2279	  presented with a 32-bit vDSO that is not mapped at the address
2280	  indicated in its segment table.
2281
2282	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2283	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2284	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2285	  the only released version with the bug, but OpenSUSE 9
2286	  contains a buggy "glibc 2.3.2".
2287
2288	  The symptom of the bug is that everything crashes on startup, saying:
2289	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2290
2291	  Saying Y here changes the default value of the vdso32 boot
2292	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2293	  This works around the glibc bug but hurts performance.
2294
2295	  If unsure, say N: if you are compiling your own kernel, you
2296	  are unlikely to be using a buggy version of glibc.
2297
2298choice
2299	prompt "vsyscall table for legacy applications"
2300	depends on X86_64
2301	default LEGACY_VSYSCALL_EMULATE
2302	help
2303	  Legacy user code that does not know how to find the vDSO expects
2304	  to be able to issue three syscalls by calling fixed addresses in
2305	  kernel space. Since this location is not randomized with ASLR,
2306	  it can be used to assist security vulnerability exploitation.
2307
2308	  This setting can be changed at boot time via the kernel command
2309	  line parameter vsyscall=[native|emulate|none].
2310
2311	  On a system with recent enough glibc (2.14 or newer) and no
2312	  static binaries, you can say None without a performance penalty
2313	  to improve security.
2314
2315	  If unsure, select "Emulate".
2316
2317	config LEGACY_VSYSCALL_NATIVE
2318		bool "Native"
2319		help
2320		  Actual executable code is located in the fixed vsyscall
2321		  address mapping, implementing time() efficiently. Since
2322		  this makes the mapping executable, it can be used during
2323		  security vulnerability exploitation (traditionally as
2324		  ROP gadgets). This configuration is not recommended.
2325
2326	config LEGACY_VSYSCALL_EMULATE
2327		bool "Emulate"
2328		help
2329		  The kernel traps and emulates calls into the fixed
2330		  vsyscall address mapping. This makes the mapping
2331		  non-executable, but it still contains known contents,
2332		  which could be used in certain rare security vulnerability
2333		  exploits. This configuration is recommended when userspace
2334		  still uses the vsyscall area.
2335
2336	config LEGACY_VSYSCALL_NONE
2337		bool "None"
2338		help
2339		  There will be no vsyscall mapping at all. This will
2340		  eliminate any risk of ASLR bypass due to the vsyscall
2341		  fixed address mapping. Attempts to use the vsyscalls
2342		  will be reported to dmesg, so that either old or
2343		  malicious userspace programs can be identified.
2344
2345endchoice
2346
2347config CMDLINE_BOOL
2348	bool "Built-in kernel command line"
2349	---help---
2350	  Allow for specifying boot arguments to the kernel at
2351	  build time.  On some systems (e.g. embedded ones), it is
2352	  necessary or convenient to provide some or all of the
2353	  kernel boot arguments with the kernel itself (that is,
2354	  to not rely on the boot loader to provide them.)
2355
2356	  To compile command line arguments into the kernel,
2357	  set this option to 'Y', then fill in the
2358	  boot arguments in CONFIG_CMDLINE.
2359
2360	  Systems with fully functional boot loaders (i.e. non-embedded)
2361	  should leave this option set to 'N'.
2362
2363config CMDLINE
2364	string "Built-in kernel command string"
2365	depends on CMDLINE_BOOL
2366	default ""
2367	---help---
2368	  Enter arguments here that should be compiled into the kernel
2369	  image and used at boot time.  If the boot loader provides a
2370	  command line at boot time, it is appended to this string to
2371	  form the full kernel command line, when the system boots.
2372
2373	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2374	  change this behavior.
2375
2376	  In most cases, the command line (whether built-in or provided
2377	  by the boot loader) should specify the device for the root
2378	  file system.
2379
2380config CMDLINE_OVERRIDE
2381	bool "Built-in command line overrides boot loader arguments"
2382	depends on CMDLINE_BOOL
2383	---help---
2384	  Set this option to 'Y' to have the kernel ignore the boot loader
2385	  command line, and use ONLY the built-in command line.
2386
2387	  This is used to work around broken boot loaders.  This should
2388	  be set to 'N' under normal conditions.
2389
2390config MODIFY_LDT_SYSCALL
2391	bool "Enable the LDT (local descriptor table)" if EXPERT
2392	default y
2393	---help---
2394	  Linux can allow user programs to install a per-process x86
2395	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2396	  call.  This is required to run 16-bit or segmented code such as
2397	  DOSEMU or some Wine programs.  It is also used by some very old
2398	  threading libraries.
2399
2400	  Enabling this feature adds a small amount of overhead to
2401	  context switches and increases the low-level kernel attack
2402	  surface.  Disabling it removes the modify_ldt(2) system call.
2403
2404	  Saying 'N' here may make sense for embedded or server kernels.
2405
2406source "kernel/livepatch/Kconfig"
2407
2408endmenu
2409
2410config ARCH_HAS_ADD_PAGES
2411	def_bool y
2412	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2413
2414config ARCH_ENABLE_MEMORY_HOTPLUG
2415	def_bool y
2416	depends on X86_64 || (X86_32 && HIGHMEM)
2417
2418config ARCH_ENABLE_MEMORY_HOTREMOVE
2419	def_bool y
2420	depends on MEMORY_HOTPLUG
2421
2422config USE_PERCPU_NUMA_NODE_ID
2423	def_bool y
2424	depends on NUMA
2425
2426config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2427	def_bool y
2428	depends on X86_64 || X86_PAE
2429
2430config ARCH_ENABLE_HUGEPAGE_MIGRATION
2431	def_bool y
2432	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2433
2434config ARCH_ENABLE_THP_MIGRATION
2435	def_bool y
2436	depends on X86_64 && TRANSPARENT_HUGEPAGE
2437
2438menu "Power management and ACPI options"
2439
2440config ARCH_HIBERNATION_HEADER
2441	def_bool y
2442	depends on X86_64 && HIBERNATION
2443
2444source "kernel/power/Kconfig"
2445
2446source "drivers/acpi/Kconfig"
2447
2448source "drivers/sfi/Kconfig"
2449
2450config X86_APM_BOOT
2451	def_bool y
2452	depends on APM
2453
2454menuconfig APM
2455	tristate "APM (Advanced Power Management) BIOS support"
2456	depends on X86_32 && PM_SLEEP
2457	---help---
2458	  APM is a BIOS specification for saving power using several different
2459	  techniques. This is mostly useful for battery powered laptops with
2460	  APM compliant BIOSes. If you say Y here, the system time will be
2461	  reset after a RESUME operation, the /proc/apm device will provide
2462	  battery status information, and user-space programs will receive
2463	  notification of APM "events" (e.g. battery status change).
2464
2465	  If you select "Y" here, you can disable actual use of the APM
2466	  BIOS by passing the "apm=off" option to the kernel at boot time.
2467
2468	  Note that the APM support is almost completely disabled for
2469	  machines with more than one CPU.
2470
2471	  In order to use APM, you will need supporting software. For location
2472	  and more information, read <file:Documentation/power/apm-acpi.txt>
2473	  and the Battery Powered Linux mini-HOWTO, available from
2474	  <http://www.tldp.org/docs.html#howto>.
2475
2476	  This driver does not spin down disk drives (see the hdparm(8)
2477	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2478	  VESA-compliant "green" monitors.
2479
2480	  This driver does not support the TI 4000M TravelMate and the ACER
2481	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2482	  desktop machines also don't have compliant BIOSes, and this driver
2483	  may cause those machines to panic during the boot phase.
2484
2485	  Generally, if you don't have a battery in your machine, there isn't
2486	  much point in using this driver and you should say N. If you get
2487	  random kernel OOPSes or reboots that don't seem to be related to
2488	  anything, try disabling/enabling this option (or disabling/enabling
2489	  APM in your BIOS).
2490
2491	  Some other things you should try when experiencing seemingly random,
2492	  "weird" problems:
2493
2494	  1) make sure that you have enough swap space and that it is
2495	  enabled.
2496	  2) pass the "no-hlt" option to the kernel
2497	  3) switch on floating point emulation in the kernel and pass
2498	  the "no387" option to the kernel
2499	  4) pass the "floppy=nodma" option to the kernel
2500	  5) pass the "mem=4M" option to the kernel (thereby disabling
2501	  all but the first 4 MB of RAM)
2502	  6) make sure that the CPU is not over clocked.
2503	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2504	  8) disable the cache from your BIOS settings
2505	  9) install a fan for the video card or exchange video RAM
2506	  10) install a better fan for the CPU
2507	  11) exchange RAM chips
2508	  12) exchange the motherboard.
2509
2510	  To compile this driver as a module, choose M here: the
2511	  module will be called apm.
2512
2513if APM
2514
2515config APM_IGNORE_USER_SUSPEND
2516	bool "Ignore USER SUSPEND"
2517	---help---
2518	  This option will ignore USER SUSPEND requests. On machines with a
2519	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2520	  series notebooks, it is necessary to say Y because of a BIOS bug.
2521
2522config APM_DO_ENABLE
2523	bool "Enable PM at boot time"
2524	---help---
2525	  Enable APM features at boot time. From page 36 of the APM BIOS
2526	  specification: "When disabled, the APM BIOS does not automatically
2527	  power manage devices, enter the Standby State, enter the Suspend
2528	  State, or take power saving steps in response to CPU Idle calls."
2529	  This driver will make CPU Idle calls when Linux is idle (unless this
2530	  feature is turned off -- see "Do CPU IDLE calls", below). This
2531	  should always save battery power, but more complicated APM features
2532	  will be dependent on your BIOS implementation. You may need to turn
2533	  this option off if your computer hangs at boot time when using APM
2534	  support, or if it beeps continuously instead of suspending. Turn
2535	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2536	  T400CDT. This is off by default since most machines do fine without
2537	  this feature.
2538
2539config APM_CPU_IDLE
2540	depends on CPU_IDLE
2541	bool "Make CPU Idle calls when idle"
2542	---help---
2543	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2544	  On some machines, this can activate improved power savings, such as
2545	  a slowed CPU clock rate, when the machine is idle. These idle calls
2546	  are made after the idle loop has run for some length of time (e.g.,
2547	  333 mS). On some machines, this will cause a hang at boot time or
2548	  whenever the CPU becomes idle. (On machines with more than one CPU,
2549	  this option does nothing.)
2550
2551config APM_DISPLAY_BLANK
2552	bool "Enable console blanking using APM"
2553	---help---
2554	  Enable console blanking using the APM. Some laptops can use this to
2555	  turn off the LCD backlight when the screen blanker of the Linux
2556	  virtual console blanks the screen. Note that this is only used by
2557	  the virtual console screen blanker, and won't turn off the backlight
2558	  when using the X Window system. This also doesn't have anything to
2559	  do with your VESA-compliant power-saving monitor. Further, this
2560	  option doesn't work for all laptops -- it might not turn off your
2561	  backlight at all, or it might print a lot of errors to the console,
2562	  especially if you are using gpm.
2563
2564config APM_ALLOW_INTS
2565	bool "Allow interrupts during APM BIOS calls"
2566	---help---
2567	  Normally we disable external interrupts while we are making calls to
2568	  the APM BIOS as a measure to lessen the effects of a badly behaving
2569	  BIOS implementation.  The BIOS should reenable interrupts if it
2570	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2571	  many of the newer IBM Thinkpads.  If you experience hangs when you
2572	  suspend, try setting this to Y.  Otherwise, say N.
2573
2574endif # APM
2575
2576source "drivers/cpufreq/Kconfig"
2577
2578source "drivers/cpuidle/Kconfig"
2579
2580source "drivers/idle/Kconfig"
2581
2582endmenu
2583
2584
2585menu "Bus options (PCI etc.)"
2586
2587config PCI
2588	bool "PCI support"
2589	default y
2590	---help---
2591	  Find out whether you have a PCI motherboard. PCI is the name of a
2592	  bus system, i.e. the way the CPU talks to the other stuff inside
2593	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2594	  VESA. If you have PCI, say Y, otherwise N.
2595
2596choice
2597	prompt "PCI access mode"
2598	depends on X86_32 && PCI
2599	default PCI_GOANY
2600	---help---
2601	  On PCI systems, the BIOS can be used to detect the PCI devices and
2602	  determine their configuration. However, some old PCI motherboards
2603	  have BIOS bugs and may crash if this is done. Also, some embedded
2604	  PCI-based systems don't have any BIOS at all. Linux can also try to
2605	  detect the PCI hardware directly without using the BIOS.
2606
2607	  With this option, you can specify how Linux should detect the
2608	  PCI devices. If you choose "BIOS", the BIOS will be used,
2609	  if you choose "Direct", the BIOS won't be used, and if you
2610	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2611	  If you choose "Any", the kernel will try MMCONFIG, then the
2612	  direct access method and falls back to the BIOS if that doesn't
2613	  work. If unsure, go with the default, which is "Any".
2614
2615config PCI_GOBIOS
2616	bool "BIOS"
2617
2618config PCI_GOMMCONFIG
2619	bool "MMConfig"
2620
2621config PCI_GODIRECT
2622	bool "Direct"
2623
2624config PCI_GOOLPC
2625	bool "OLPC XO-1"
2626	depends on OLPC
2627
2628config PCI_GOANY
2629	bool "Any"
2630
2631endchoice
2632
2633config PCI_BIOS
2634	def_bool y
2635	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2636
2637# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2638config PCI_DIRECT
2639	def_bool y
2640	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2641
2642config PCI_MMCONFIG
2643	def_bool y
2644	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2645
2646config PCI_OLPC
2647	def_bool y
2648	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2649
2650config PCI_XEN
2651	def_bool y
2652	depends on PCI && XEN
2653	select SWIOTLB_XEN
2654
2655config PCI_DOMAINS
2656	def_bool y
2657	depends on PCI
2658
2659config PCI_MMCONFIG
2660	bool "Support mmconfig PCI config space access"
2661	depends on X86_64 && PCI && ACPI
2662
2663config PCI_CNB20LE_QUIRK
2664	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2665	depends on PCI
2666	help
2667	  Read the PCI windows out of the CNB20LE host bridge. This allows
2668	  PCI hotplug to work on systems with the CNB20LE chipset which do
2669	  not have ACPI.
2670
2671	  There's no public spec for this chipset, and this functionality
2672	  is known to be incomplete.
2673
2674	  You should say N unless you know you need this.
2675
2676source "drivers/pci/Kconfig"
2677
2678config ISA_BUS
2679	bool "ISA-style bus support on modern systems" if EXPERT
2680	select ISA_BUS_API
2681	help
2682	  Enables ISA-style drivers on modern systems. This is necessary to
2683	  support PC/104 devices on X86_64 platforms.
2684
2685	  If unsure, say N.
2686
2687# x86_64 have no ISA slots, but can have ISA-style DMA.
2688config ISA_DMA_API
2689	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2690	default y
2691	help
2692	  Enables ISA-style DMA support for devices requiring such controllers.
2693	  If unsure, say Y.
2694
2695if X86_32
2696
2697config ISA
2698	bool "ISA support"
2699	---help---
2700	  Find out whether you have ISA slots on your motherboard.  ISA is the
2701	  name of a bus system, i.e. the way the CPU talks to the other stuff
2702	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2703	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2704	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2705
2706config EISA
2707	bool "EISA support"
2708	depends on ISA
2709	---help---
2710	  The Extended Industry Standard Architecture (EISA) bus was
2711	  developed as an open alternative to the IBM MicroChannel bus.
2712
2713	  The EISA bus provided some of the features of the IBM MicroChannel
2714	  bus while maintaining backward compatibility with cards made for
2715	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2716	  1995 when it was made obsolete by the PCI bus.
2717
2718	  Say Y here if you are building a kernel for an EISA-based machine.
2719
2720	  Otherwise, say N.
2721
2722source "drivers/eisa/Kconfig"
2723
2724config SCx200
2725	tristate "NatSemi SCx200 support"
2726	---help---
2727	  This provides basic support for National Semiconductor's
2728	  (now AMD's) Geode processors.  The driver probes for the
2729	  PCI-IDs of several on-chip devices, so its a good dependency
2730	  for other scx200_* drivers.
2731
2732	  If compiled as a module, the driver is named scx200.
2733
2734config SCx200HR_TIMER
2735	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2736	depends on SCx200
2737	default y
2738	---help---
2739	  This driver provides a clocksource built upon the on-chip
2740	  27MHz high-resolution timer.  Its also a workaround for
2741	  NSC Geode SC-1100's buggy TSC, which loses time when the
2742	  processor goes idle (as is done by the scheduler).  The
2743	  other workaround is idle=poll boot option.
2744
2745config OLPC
2746	bool "One Laptop Per Child support"
2747	depends on !X86_PAE
2748	select GPIOLIB
2749	select OF
2750	select OF_PROMTREE
2751	select IRQ_DOMAIN
2752	---help---
2753	  Add support for detecting the unique features of the OLPC
2754	  XO hardware.
2755
2756config OLPC_XO1_PM
2757	bool "OLPC XO-1 Power Management"
2758	depends on OLPC && MFD_CS5535 && PM_SLEEP
2759	select MFD_CORE
2760	---help---
2761	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2762
2763config OLPC_XO1_RTC
2764	bool "OLPC XO-1 Real Time Clock"
2765	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2766	---help---
2767	  Add support for the XO-1 real time clock, which can be used as a
2768	  programmable wakeup source.
2769
2770config OLPC_XO1_SCI
2771	bool "OLPC XO-1 SCI extras"
2772	depends on OLPC && OLPC_XO1_PM
2773	depends on INPUT=y
2774	select POWER_SUPPLY
2775	select GPIO_CS5535
2776	select MFD_CORE
2777	---help---
2778	  Add support for SCI-based features of the OLPC XO-1 laptop:
2779	   - EC-driven system wakeups
2780	   - Power button
2781	   - Ebook switch
2782	   - Lid switch
2783	   - AC adapter status updates
2784	   - Battery status updates
2785
2786config OLPC_XO15_SCI
2787	bool "OLPC XO-1.5 SCI extras"
2788	depends on OLPC && ACPI
2789	select POWER_SUPPLY
2790	---help---
2791	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2792	   - EC-driven system wakeups
2793	   - AC adapter status updates
2794	   - Battery status updates
2795
2796config ALIX
2797	bool "PCEngines ALIX System Support (LED setup)"
2798	select GPIOLIB
2799	---help---
2800	  This option enables system support for the PCEngines ALIX.
2801	  At present this just sets up LEDs for GPIO control on
2802	  ALIX2/3/6 boards.  However, other system specific setup should
2803	  get added here.
2804
2805	  Note: You must still enable the drivers for GPIO and LED support
2806	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2807
2808	  Note: You have to set alix.force=1 for boards with Award BIOS.
2809
2810config NET5501
2811	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2812	select GPIOLIB
2813	---help---
2814	  This option enables system support for the Soekris Engineering net5501.
2815
2816config GEOS
2817	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2818	select GPIOLIB
2819	depends on DMI
2820	---help---
2821	  This option enables system support for the Traverse Technologies GEOS.
2822
2823config TS5500
2824	bool "Technologic Systems TS-5500 platform support"
2825	depends on MELAN
2826	select CHECK_SIGNATURE
2827	select NEW_LEDS
2828	select LEDS_CLASS
2829	---help---
2830	  This option enables system support for the Technologic Systems TS-5500.
2831
2832endif # X86_32
2833
2834config AMD_NB
2835	def_bool y
2836	depends on CPU_SUP_AMD && PCI
2837
2838source "drivers/pcmcia/Kconfig"
2839
2840config RAPIDIO
2841	tristate "RapidIO support"
2842	depends on PCI
2843	default n
2844	help
2845	  If enabled this option will include drivers and the core
2846	  infrastructure code to support RapidIO interconnect devices.
2847
2848source "drivers/rapidio/Kconfig"
2849
2850config X86_SYSFB
2851	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2852	help
2853	  Firmwares often provide initial graphics framebuffers so the BIOS,
2854	  bootloader or kernel can show basic video-output during boot for
2855	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2856	  Extensions and EFI-framebuffers for this, which are mostly limited
2857	  to x86.
2858	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2859	  framebuffers so the new generic system-framebuffer drivers can be
2860	  used on x86. If the framebuffer is not compatible with the generic
2861	  modes, it is adverticed as fallback platform framebuffer so legacy
2862	  drivers like efifb, vesafb and uvesafb can pick it up.
2863	  If this option is not selected, all system framebuffers are always
2864	  marked as fallback platform framebuffers as usual.
2865
2866	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2867	  not be able to pick up generic system framebuffers if this option
2868	  is selected. You are highly encouraged to enable simplefb as
2869	  replacement if you select this option. simplefb can correctly deal
2870	  with generic system framebuffers. But you should still keep vesafb
2871	  and others enabled as fallback if a system framebuffer is
2872	  incompatible with simplefb.
2873
2874	  If unsure, say Y.
2875
2876endmenu
2877
2878
2879menu "Executable file formats / Emulations"
2880
2881source "fs/Kconfig.binfmt"
2882
2883config IA32_EMULATION
2884	bool "IA32 Emulation"
2885	depends on X86_64
2886	select ARCH_WANT_OLD_COMPAT_IPC
2887	select BINFMT_ELF
2888	select COMPAT_BINFMT_ELF
2889	select COMPAT_OLD_SIGACTION
2890	---help---
2891	  Include code to run legacy 32-bit programs under a
2892	  64-bit kernel. You should likely turn this on, unless you're
2893	  100% sure that you don't have any 32-bit programs left.
2894
2895config IA32_AOUT
2896	tristate "IA32 a.out support"
2897	depends on IA32_EMULATION
2898	---help---
2899	  Support old a.out binaries in the 32bit emulation.
2900
2901config X86_X32
2902	bool "x32 ABI for 64-bit mode"
2903	depends on X86_64
2904	---help---
2905	  Include code to run binaries for the x32 native 32-bit ABI
2906	  for 64-bit processors.  An x32 process gets access to the
2907	  full 64-bit register file and wide data path while leaving
2908	  pointers at 32 bits for smaller memory footprint.
2909
2910	  You will need a recent binutils (2.22 or later) with
2911	  elf32_x86_64 support enabled to compile a kernel with this
2912	  option set.
2913
2914config COMPAT_32
2915	def_bool y
2916	depends on IA32_EMULATION || X86_32
2917	select HAVE_UID16
2918	select OLD_SIGSUSPEND3
2919
2920config COMPAT
2921	def_bool y
2922	depends on IA32_EMULATION || X86_X32
2923
2924if COMPAT
2925config COMPAT_FOR_U64_ALIGNMENT
2926	def_bool y
2927
2928config SYSVIPC_COMPAT
2929	def_bool y
2930	depends on SYSVIPC
2931endif
2932
2933endmenu
2934
2935
2936config HAVE_ATOMIC_IOMAP
2937	def_bool y
2938	depends on X86_32
2939
2940config X86_DEV_DMA_OPS
2941	bool
2942	depends on X86_64 || STA2X11
2943
2944config X86_DMA_REMAP
2945	bool
2946	depends on STA2X11
2947
2948config HAVE_GENERIC_GUP
2949	def_bool y
2950
2951source "net/Kconfig"
2952
2953source "drivers/Kconfig"
2954
2955source "drivers/firmware/Kconfig"
2956
2957source "fs/Kconfig"
2958
2959source "arch/x86/Kconfig.debug"
2960
2961source "security/Kconfig"
2962
2963source "crypto/Kconfig"
2964
2965source "arch/x86/kvm/Kconfig"
2966
2967source "lib/Kconfig"
2968