xref: /openbmc/linux/arch/x86/Kconfig (revision ff4a7481c3898ffc3cc271d6aca431d190c37247)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select X86_DEV_DMA_OPS
34	select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40#   ported to 32-bit as well. )
41#
42config X86
43	def_bool y
44	#
45	# Note: keep this list sorted alphabetically
46	#
47	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
48	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
49	select ANON_INODES
50	select ARCH_CLOCKSOURCE_DATA
51	select ARCH_CLOCKSOURCE_INIT
52	select ARCH_DISCARD_MEMBLOCK
53	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
54	select ARCH_HAS_DEBUG_VIRTUAL
55	select ARCH_HAS_DEVMEM_IS_ALLOWED
56	select ARCH_HAS_ELF_RANDOMIZE
57	select ARCH_HAS_FAST_MULTIPLIER
58	select ARCH_HAS_FILTER_PGPROT
59	select ARCH_HAS_FORTIFY_SOURCE
60	select ARCH_HAS_GCOV_PROFILE_ALL
61	select ARCH_HAS_KCOV			if X86_64
62	select ARCH_HAS_MEMBARRIER_SYNC_CORE
63	select ARCH_HAS_PMEM_API		if X86_64
64	select ARCH_HAS_PTE_SPECIAL
65	select ARCH_HAS_REFCOUNT
66	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
67	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
68	select ARCH_HAS_SET_MEMORY
69	select ARCH_HAS_SG_CHAIN
70	select ARCH_HAS_STRICT_KERNEL_RWX
71	select ARCH_HAS_STRICT_MODULE_RWX
72	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
73	select ARCH_HAS_UBSAN_SANITIZE_ALL
74	select ARCH_HAS_ZONE_DEVICE		if X86_64
75	select ARCH_HAVE_NMI_SAFE_CMPXCHG
76	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
77	select ARCH_MIGHT_HAVE_PC_PARPORT
78	select ARCH_MIGHT_HAVE_PC_SERIO
79	select ARCH_SUPPORTS_ACPI
80	select ARCH_SUPPORTS_ATOMIC_RMW
81	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
82	select ARCH_USE_BUILTIN_BSWAP
83	select ARCH_USE_QUEUED_RWLOCKS
84	select ARCH_USE_QUEUED_SPINLOCKS
85	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
86	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
87	select ARCH_WANTS_THP_SWAP		if X86_64
88	select BUILDTIME_EXTABLE_SORT
89	select CLKEVT_I8253
90	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
91	select CLOCKSOURCE_WATCHDOG
92	select DCACHE_WORD_ACCESS
93	select DMA_DIRECT_OPS
94	select EDAC_ATOMIC_SCRUB
95	select EDAC_SUPPORT
96	select GENERIC_CLOCKEVENTS
97	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
98	select GENERIC_CLOCKEVENTS_MIN_ADJUST
99	select GENERIC_CMOS_UPDATE
100	select GENERIC_CPU_AUTOPROBE
101	select GENERIC_CPU_VULNERABILITIES
102	select GENERIC_EARLY_IOREMAP
103	select GENERIC_FIND_FIRST_BIT
104	select GENERIC_IOMAP
105	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
106	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
107	select GENERIC_IRQ_MIGRATION		if SMP
108	select GENERIC_IRQ_PROBE
109	select GENERIC_IRQ_RESERVATION_MODE
110	select GENERIC_IRQ_SHOW
111	select GENERIC_PENDING_IRQ		if SMP
112	select GENERIC_SMP_IDLE_THREAD
113	select GENERIC_STRNCPY_FROM_USER
114	select GENERIC_STRNLEN_USER
115	select GENERIC_TIME_VSYSCALL
116	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
117	select HAVE_ACPI_APEI			if ACPI
118	select HAVE_ACPI_APEI_NMI		if ACPI
119	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
120	select HAVE_ARCH_AUDITSYSCALL
121	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
122	select HAVE_ARCH_JUMP_LABEL
123	select HAVE_ARCH_JUMP_LABEL_RELATIVE
124	select HAVE_ARCH_KASAN			if X86_64
125	select HAVE_ARCH_KGDB
126	select HAVE_ARCH_MMAP_RND_BITS		if MMU
127	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
128	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
129	select HAVE_ARCH_PREL32_RELOCATIONS
130	select HAVE_ARCH_SECCOMP_FILTER
131	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
132	select HAVE_ARCH_STACKLEAK
133	select HAVE_ARCH_TRACEHOOK
134	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
135	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
136	select HAVE_ARCH_VMAP_STACK		if X86_64
137	select HAVE_ARCH_WITHIN_STACK_FRAMES
138	select HAVE_CMPXCHG_DOUBLE
139	select HAVE_CMPXCHG_LOCAL
140	select HAVE_CONTEXT_TRACKING		if X86_64
141	select HAVE_COPY_THREAD_TLS
142	select HAVE_C_RECORDMCOUNT
143	select HAVE_DEBUG_KMEMLEAK
144	select HAVE_DEBUG_STACKOVERFLOW
145	select HAVE_DMA_CONTIGUOUS
146	select HAVE_DYNAMIC_FTRACE
147	select HAVE_DYNAMIC_FTRACE_WITH_REGS
148	select HAVE_EBPF_JIT
149	select HAVE_EFFICIENT_UNALIGNED_ACCESS
150	select HAVE_EXIT_THREAD
151	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
152	select HAVE_FTRACE_MCOUNT_RECORD
153	select HAVE_FUNCTION_GRAPH_TRACER
154	select HAVE_FUNCTION_TRACER
155	select HAVE_GCC_PLUGINS
156	select HAVE_HW_BREAKPOINT
157	select HAVE_IDE
158	select HAVE_IOREMAP_PROT
159	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
160	select HAVE_IRQ_TIME_ACCOUNTING
161	select HAVE_KERNEL_BZIP2
162	select HAVE_KERNEL_GZIP
163	select HAVE_KERNEL_LZ4
164	select HAVE_KERNEL_LZMA
165	select HAVE_KERNEL_LZO
166	select HAVE_KERNEL_XZ
167	select HAVE_KPROBES
168	select HAVE_KPROBES_ON_FTRACE
169	select HAVE_FUNCTION_ERROR_INJECTION
170	select HAVE_KRETPROBES
171	select HAVE_KVM
172	select HAVE_LIVEPATCH			if X86_64
173	select HAVE_MEMBLOCK_NODE_MAP
174	select HAVE_MIXED_BREAKPOINTS_REGS
175	select HAVE_MOD_ARCH_SPECIFIC
176	select HAVE_NMI
177	select HAVE_OPROFILE
178	select HAVE_OPTPROBES
179	select HAVE_PCSPKR_PLATFORM
180	select HAVE_PERF_EVENTS
181	select HAVE_PERF_EVENTS_NMI
182	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
183	select HAVE_PERF_REGS
184	select HAVE_PERF_USER_STACK_DUMP
185	select HAVE_RCU_TABLE_FREE		if PARAVIRT
186	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
187	select HAVE_REGS_AND_STACK_ACCESS_API
188	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
189	select HAVE_FUNCTION_ARG_ACCESS_API
190	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
191	select HAVE_STACK_VALIDATION		if X86_64
192	select HAVE_RSEQ
193	select HAVE_SYSCALL_TRACEPOINTS
194	select HAVE_UNSTABLE_SCHED_CLOCK
195	select HAVE_USER_RETURN_NOTIFIER
196	select HOTPLUG_SMT			if SMP
197	select IRQ_FORCED_THREADING
198	select NEED_SG_DMA_LENGTH
199	select PCI_LOCKLESS_CONFIG
200	select PERF_EVENTS
201	select RTC_LIB
202	select RTC_MC146818_LIB
203	select SPARSE_IRQ
204	select SRCU
205	select SYSCTL_EXCEPTION_TRACE
206	select THREAD_INFO_IN_TASK
207	select USER_STACKTRACE_SUPPORT
208	select VIRT_TO_BUS
209	select X86_FEATURE_NAMES		if PROC_FS
210
211config INSTRUCTION_DECODER
212	def_bool y
213	depends on KPROBES || PERF_EVENTS || UPROBES
214
215config OUTPUT_FORMAT
216	string
217	default "elf32-i386" if X86_32
218	default "elf64-x86-64" if X86_64
219
220config ARCH_DEFCONFIG
221	string
222	default "arch/x86/configs/i386_defconfig" if X86_32
223	default "arch/x86/configs/x86_64_defconfig" if X86_64
224
225config LOCKDEP_SUPPORT
226	def_bool y
227
228config STACKTRACE_SUPPORT
229	def_bool y
230
231config MMU
232	def_bool y
233
234config ARCH_MMAP_RND_BITS_MIN
235	default 28 if 64BIT
236	default 8
237
238config ARCH_MMAP_RND_BITS_MAX
239	default 32 if 64BIT
240	default 16
241
242config ARCH_MMAP_RND_COMPAT_BITS_MIN
243	default 8
244
245config ARCH_MMAP_RND_COMPAT_BITS_MAX
246	default 16
247
248config SBUS
249	bool
250
251config GENERIC_ISA_DMA
252	def_bool y
253	depends on ISA_DMA_API
254
255config GENERIC_BUG
256	def_bool y
257	depends on BUG
258	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
259
260config GENERIC_BUG_RELATIVE_POINTERS
261	bool
262
263config GENERIC_HWEIGHT
264	def_bool y
265
266config ARCH_MAY_HAVE_PC_FDC
267	def_bool y
268	depends on ISA_DMA_API
269
270config RWSEM_XCHGADD_ALGORITHM
271	def_bool y
272
273config GENERIC_CALIBRATE_DELAY
274	def_bool y
275
276config ARCH_HAS_CPU_RELAX
277	def_bool y
278
279config ARCH_HAS_CACHE_LINE_SIZE
280	def_bool y
281
282config ARCH_HAS_FILTER_PGPROT
283	def_bool y
284
285config HAVE_SETUP_PER_CPU_AREA
286	def_bool y
287
288config NEED_PER_CPU_EMBED_FIRST_CHUNK
289	def_bool y
290
291config NEED_PER_CPU_PAGE_FIRST_CHUNK
292	def_bool y
293
294config ARCH_HIBERNATION_POSSIBLE
295	def_bool y
296
297config ARCH_SUSPEND_POSSIBLE
298	def_bool y
299
300config ARCH_WANT_HUGE_PMD_SHARE
301	def_bool y
302
303config ARCH_WANT_GENERAL_HUGETLB
304	def_bool y
305
306config ZONE_DMA32
307	def_bool y if X86_64
308
309config AUDIT_ARCH
310	def_bool y if X86_64
311
312config ARCH_SUPPORTS_OPTIMIZED_INLINING
313	def_bool y
314
315config ARCH_SUPPORTS_DEBUG_PAGEALLOC
316	def_bool y
317
318config KASAN_SHADOW_OFFSET
319	hex
320	depends on KASAN
321	default 0xdffffc0000000000
322
323config HAVE_INTEL_TXT
324	def_bool y
325	depends on INTEL_IOMMU && ACPI
326
327config X86_32_SMP
328	def_bool y
329	depends on X86_32 && SMP
330
331config X86_64_SMP
332	def_bool y
333	depends on X86_64 && SMP
334
335config X86_32_LAZY_GS
336	def_bool y
337	depends on X86_32 && !STACKPROTECTOR
338
339config ARCH_SUPPORTS_UPROBES
340	def_bool y
341
342config FIX_EARLYCON_MEM
343	def_bool y
344
345config DYNAMIC_PHYSICAL_MASK
346	bool
347
348config PGTABLE_LEVELS
349	int
350	default 5 if X86_5LEVEL
351	default 4 if X86_64
352	default 3 if X86_PAE
353	default 2
354
355config CC_HAS_SANE_STACKPROTECTOR
356	bool
357	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
358	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
359	help
360	   We have to make sure stack protector is unconditionally disabled if
361	   the compiler produces broken code.
362
363menu "Processor type and features"
364
365config ZONE_DMA
366	bool "DMA memory allocation support" if EXPERT
367	default y
368	help
369	  DMA memory allocation support allows devices with less than 32-bit
370	  addressing to allocate within the first 16MB of address space.
371	  Disable if no such devices will be used.
372
373	  If unsure, say Y.
374
375config SMP
376	bool "Symmetric multi-processing support"
377	---help---
378	  This enables support for systems with more than one CPU. If you have
379	  a system with only one CPU, say N. If you have a system with more
380	  than one CPU, say Y.
381
382	  If you say N here, the kernel will run on uni- and multiprocessor
383	  machines, but will use only one CPU of a multiprocessor machine. If
384	  you say Y here, the kernel will run on many, but not all,
385	  uniprocessor machines. On a uniprocessor machine, the kernel
386	  will run faster if you say N here.
387
388	  Note that if you say Y here and choose architecture "586" or
389	  "Pentium" under "Processor family", the kernel will not work on 486
390	  architectures. Similarly, multiprocessor kernels for the "PPro"
391	  architecture may not work on all Pentium based boards.
392
393	  People using multiprocessor machines who say Y here should also say
394	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
395	  Management" code will be disabled if you say Y here.
396
397	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
398	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
399	  <http://www.tldp.org/docs.html#howto>.
400
401	  If you don't know what to do here, say N.
402
403config X86_FEATURE_NAMES
404	bool "Processor feature human-readable names" if EMBEDDED
405	default y
406	---help---
407	  This option compiles in a table of x86 feature bits and corresponding
408	  names.  This is required to support /proc/cpuinfo and a few kernel
409	  messages.  You can disable this to save space, at the expense of
410	  making those few kernel messages show numeric feature bits instead.
411
412	  If in doubt, say Y.
413
414config X86_X2APIC
415	bool "Support x2apic"
416	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
417	---help---
418	  This enables x2apic support on CPUs that have this feature.
419
420	  This allows 32-bit apic IDs (so it can support very large systems),
421	  and accesses the local apic via MSRs not via mmio.
422
423	  If you don't know what to do here, say N.
424
425config X86_MPPARSE
426	bool "Enable MPS table" if ACPI || SFI
427	default y
428	depends on X86_LOCAL_APIC
429	---help---
430	  For old smp systems that do not have proper acpi support. Newer systems
431	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
432
433config GOLDFISH
434       def_bool y
435       depends on X86_GOLDFISH
436
437config RETPOLINE
438	bool "Avoid speculative indirect branches in kernel"
439	default y
440	select STACK_VALIDATION if HAVE_STACK_VALIDATION
441	help
442	  Compile kernel with the retpoline compiler options to guard against
443	  kernel-to-user data leaks by avoiding speculative indirect
444	  branches. Requires a compiler with -mindirect-branch=thunk-extern
445	  support for full protection. The kernel may run slower.
446
447config RESCTRL
448	bool "Resource Control support"
449	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
450	select KERNFS
451	help
452	  Enable Resource Control support.
453
454	  Provide support for the allocation and monitoring of system resources
455	  usage by the CPU.
456
457	  Intel calls this Intel Resource Director Technology
458	  (Intel(R) RDT). More information about RDT can be found in the
459	  Intel x86 Architecture Software Developer Manual.
460
461	  AMD calls this AMD Platform Quality of Service (AMD QoS).
462	  More information about AMD QoS can be found in the AMD64 Technology
463	  Platform Quality of Service Extensions manual.
464
465	  Say N if unsure.
466
467if X86_32
468config X86_BIGSMP
469	bool "Support for big SMP systems with more than 8 CPUs"
470	depends on SMP
471	---help---
472	  This option is needed for the systems that have more than 8 CPUs
473
474config X86_EXTENDED_PLATFORM
475	bool "Support for extended (non-PC) x86 platforms"
476	default y
477	---help---
478	  If you disable this option then the kernel will only support
479	  standard PC platforms. (which covers the vast majority of
480	  systems out there.)
481
482	  If you enable this option then you'll be able to select support
483	  for the following (non-PC) 32 bit x86 platforms:
484		Goldfish (Android emulator)
485		AMD Elan
486		RDC R-321x SoC
487		SGI 320/540 (Visual Workstation)
488		STA2X11-based (e.g. Northville)
489		Moorestown MID devices
490
491	  If you have one of these systems, or if you want to build a
492	  generic distribution kernel, say Y here - otherwise say N.
493endif
494
495if X86_64
496config X86_EXTENDED_PLATFORM
497	bool "Support for extended (non-PC) x86 platforms"
498	default y
499	---help---
500	  If you disable this option then the kernel will only support
501	  standard PC platforms. (which covers the vast majority of
502	  systems out there.)
503
504	  If you enable this option then you'll be able to select support
505	  for the following (non-PC) 64 bit x86 platforms:
506		Numascale NumaChip
507		ScaleMP vSMP
508		SGI Ultraviolet
509
510	  If you have one of these systems, or if you want to build a
511	  generic distribution kernel, say Y here - otherwise say N.
512endif
513# This is an alphabetically sorted list of 64 bit extended platforms
514# Please maintain the alphabetic order if and when there are additions
515config X86_NUMACHIP
516	bool "Numascale NumaChip"
517	depends on X86_64
518	depends on X86_EXTENDED_PLATFORM
519	depends on NUMA
520	depends on SMP
521	depends on X86_X2APIC
522	depends on PCI_MMCONFIG
523	---help---
524	  Adds support for Numascale NumaChip large-SMP systems. Needed to
525	  enable more than ~168 cores.
526	  If you don't have one of these, you should say N here.
527
528config X86_VSMP
529	bool "ScaleMP vSMP"
530	select HYPERVISOR_GUEST
531	select PARAVIRT
532	depends on X86_64 && PCI
533	depends on X86_EXTENDED_PLATFORM
534	depends on SMP
535	---help---
536	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
537	  supposed to run on these EM64T-based machines.  Only choose this option
538	  if you have one of these machines.
539
540config X86_UV
541	bool "SGI Ultraviolet"
542	depends on X86_64
543	depends on X86_EXTENDED_PLATFORM
544	depends on NUMA
545	depends on EFI
546	depends on X86_X2APIC
547	depends on PCI
548	---help---
549	  This option is needed in order to support SGI Ultraviolet systems.
550	  If you don't have one of these, you should say N here.
551
552# Following is an alphabetically sorted list of 32 bit extended platforms
553# Please maintain the alphabetic order if and when there are additions
554
555config X86_GOLDFISH
556       bool "Goldfish (Virtual Platform)"
557       depends on X86_EXTENDED_PLATFORM
558       ---help---
559	 Enable support for the Goldfish virtual platform used primarily
560	 for Android development. Unless you are building for the Android
561	 Goldfish emulator say N here.
562
563config X86_INTEL_CE
564	bool "CE4100 TV platform"
565	depends on PCI
566	depends on PCI_GODIRECT
567	depends on X86_IO_APIC
568	depends on X86_32
569	depends on X86_EXTENDED_PLATFORM
570	select X86_REBOOTFIXUPS
571	select OF
572	select OF_EARLY_FLATTREE
573	---help---
574	  Select for the Intel CE media processor (CE4100) SOC.
575	  This option compiles in support for the CE4100 SOC for settop
576	  boxes and media devices.
577
578config X86_INTEL_MID
579	bool "Intel MID platform support"
580	depends on X86_EXTENDED_PLATFORM
581	depends on X86_PLATFORM_DEVICES
582	depends on PCI
583	depends on X86_64 || (PCI_GOANY && X86_32)
584	depends on X86_IO_APIC
585	select SFI
586	select I2C
587	select DW_APB_TIMER
588	select APB_TIMER
589	select INTEL_SCU_IPC
590	select MFD_INTEL_MSIC
591	---help---
592	  Select to build a kernel capable of supporting Intel MID (Mobile
593	  Internet Device) platform systems which do not have the PCI legacy
594	  interfaces. If you are building for a PC class system say N here.
595
596	  Intel MID platforms are based on an Intel processor and chipset which
597	  consume less power than most of the x86 derivatives.
598
599config X86_INTEL_QUARK
600	bool "Intel Quark platform support"
601	depends on X86_32
602	depends on X86_EXTENDED_PLATFORM
603	depends on X86_PLATFORM_DEVICES
604	depends on X86_TSC
605	depends on PCI
606	depends on PCI_GOANY
607	depends on X86_IO_APIC
608	select IOSF_MBI
609	select INTEL_IMR
610	select COMMON_CLK
611	---help---
612	  Select to include support for Quark X1000 SoC.
613	  Say Y here if you have a Quark based system such as the Arduino
614	  compatible Intel Galileo.
615
616config X86_INTEL_LPSS
617	bool "Intel Low Power Subsystem Support"
618	depends on X86 && ACPI
619	select COMMON_CLK
620	select PINCTRL
621	select IOSF_MBI
622	---help---
623	  Select to build support for Intel Low Power Subsystem such as
624	  found on Intel Lynxpoint PCH. Selecting this option enables
625	  things like clock tree (common clock framework) and pincontrol
626	  which are needed by the LPSS peripheral drivers.
627
628config X86_AMD_PLATFORM_DEVICE
629	bool "AMD ACPI2Platform devices support"
630	depends on ACPI
631	select COMMON_CLK
632	select PINCTRL
633	---help---
634	  Select to interpret AMD specific ACPI device to platform device
635	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
636	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
637	  implemented under PINCTRL subsystem.
638
639config IOSF_MBI
640	tristate "Intel SoC IOSF Sideband support for SoC platforms"
641	depends on PCI
642	---help---
643	  This option enables sideband register access support for Intel SoC
644	  platforms. On these platforms the IOSF sideband is used in lieu of
645	  MSR's for some register accesses, mostly but not limited to thermal
646	  and power. Drivers may query the availability of this device to
647	  determine if they need the sideband in order to work on these
648	  platforms. The sideband is available on the following SoC products.
649	  This list is not meant to be exclusive.
650	   - BayTrail
651	   - Braswell
652	   - Quark
653
654	  You should say Y if you are running a kernel on one of these SoC's.
655
656config IOSF_MBI_DEBUG
657	bool "Enable IOSF sideband access through debugfs"
658	depends on IOSF_MBI && DEBUG_FS
659	---help---
660	  Select this option to expose the IOSF sideband access registers (MCR,
661	  MDR, MCRX) through debugfs to write and read register information from
662	  different units on the SoC. This is most useful for obtaining device
663	  state information for debug and analysis. As this is a general access
664	  mechanism, users of this option would have specific knowledge of the
665	  device they want to access.
666
667	  If you don't require the option or are in doubt, say N.
668
669config X86_RDC321X
670	bool "RDC R-321x SoC"
671	depends on X86_32
672	depends on X86_EXTENDED_PLATFORM
673	select M486
674	select X86_REBOOTFIXUPS
675	---help---
676	  This option is needed for RDC R-321x system-on-chip, also known
677	  as R-8610-(G).
678	  If you don't have one of these chips, you should say N here.
679
680config X86_32_NON_STANDARD
681	bool "Support non-standard 32-bit SMP architectures"
682	depends on X86_32 && SMP
683	depends on X86_EXTENDED_PLATFORM
684	---help---
685	  This option compiles in the bigsmp and STA2X11 default
686	  subarchitectures.  It is intended for a generic binary
687	  kernel. If you select them all, kernel will probe it one by
688	  one and will fallback to default.
689
690# Alphabetically sorted list of Non standard 32 bit platforms
691
692config X86_SUPPORTS_MEMORY_FAILURE
693	def_bool y
694	# MCE code calls memory_failure():
695	depends on X86_MCE
696	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
697	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
698	depends on X86_64 || !SPARSEMEM
699	select ARCH_SUPPORTS_MEMORY_FAILURE
700
701config STA2X11
702	bool "STA2X11 Companion Chip Support"
703	depends on X86_32_NON_STANDARD && PCI
704	select ARCH_HAS_PHYS_TO_DMA
705	select X86_DEV_DMA_OPS
706	select X86_DMA_REMAP
707	select SWIOTLB
708	select MFD_STA2X11
709	select GPIOLIB
710	---help---
711	  This adds support for boards based on the STA2X11 IO-Hub,
712	  a.k.a. "ConneXt". The chip is used in place of the standard
713	  PC chipset, so all "standard" peripherals are missing. If this
714	  option is selected the kernel will still be able to boot on
715	  standard PC machines.
716
717config X86_32_IRIS
718	tristate "Eurobraille/Iris poweroff module"
719	depends on X86_32
720	---help---
721	  The Iris machines from EuroBraille do not have APM or ACPI support
722	  to shut themselves down properly.  A special I/O sequence is
723	  needed to do so, which is what this module does at
724	  kernel shutdown.
725
726	  This is only for Iris machines from EuroBraille.
727
728	  If unused, say N.
729
730config SCHED_OMIT_FRAME_POINTER
731	def_bool y
732	prompt "Single-depth WCHAN output"
733	depends on X86
734	---help---
735	  Calculate simpler /proc/<PID>/wchan values. If this option
736	  is disabled then wchan values will recurse back to the
737	  caller function. This provides more accurate wchan values,
738	  at the expense of slightly more scheduling overhead.
739
740	  If in doubt, say "Y".
741
742menuconfig HYPERVISOR_GUEST
743	bool "Linux guest support"
744	---help---
745	  Say Y here to enable options for running Linux under various hyper-
746	  visors. This option enables basic hypervisor detection and platform
747	  setup.
748
749	  If you say N, all options in this submenu will be skipped and
750	  disabled, and Linux guest support won't be built in.
751
752if HYPERVISOR_GUEST
753
754config PARAVIRT
755	bool "Enable paravirtualization code"
756	---help---
757	  This changes the kernel so it can modify itself when it is run
758	  under a hypervisor, potentially improving performance significantly
759	  over full virtualization.  However, when run without a hypervisor
760	  the kernel is theoretically slower and slightly larger.
761
762config PARAVIRT_XXL
763	bool
764
765config PARAVIRT_DEBUG
766	bool "paravirt-ops debugging"
767	depends on PARAVIRT && DEBUG_KERNEL
768	---help---
769	  Enable to debug paravirt_ops internals.  Specifically, BUG if
770	  a paravirt_op is missing when it is called.
771
772config PARAVIRT_SPINLOCKS
773	bool "Paravirtualization layer for spinlocks"
774	depends on PARAVIRT && SMP
775	---help---
776	  Paravirtualized spinlocks allow a pvops backend to replace the
777	  spinlock implementation with something virtualization-friendly
778	  (for example, block the virtual CPU rather than spinning).
779
780	  It has a minimal impact on native kernels and gives a nice performance
781	  benefit on paravirtualized KVM / Xen kernels.
782
783	  If you are unsure how to answer this question, answer Y.
784
785config QUEUED_LOCK_STAT
786	bool "Paravirt queued spinlock statistics"
787	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
788	---help---
789	  Enable the collection of statistical data on the slowpath
790	  behavior of paravirtualized queued spinlocks and report
791	  them on debugfs.
792
793source "arch/x86/xen/Kconfig"
794
795config KVM_GUEST
796	bool "KVM Guest support (including kvmclock)"
797	depends on PARAVIRT
798	select PARAVIRT_CLOCK
799	default y
800	---help---
801	  This option enables various optimizations for running under the KVM
802	  hypervisor. It includes a paravirtualized clock, so that instead
803	  of relying on a PIT (or probably other) emulation by the
804	  underlying device model, the host provides the guest with
805	  timing infrastructure such as time of day, and system time
806
807config PVH
808	bool "Support for running PVH guests"
809	---help---
810	  This option enables the PVH entry point for guest virtual machines
811	  as specified in the x86/HVM direct boot ABI.
812
813config KVM_DEBUG_FS
814	bool "Enable debug information for KVM Guests in debugfs"
815	depends on KVM_GUEST && DEBUG_FS
816	---help---
817	  This option enables collection of various statistics for KVM guest.
818	  Statistics are displayed in debugfs filesystem. Enabling this option
819	  may incur significant overhead.
820
821config PARAVIRT_TIME_ACCOUNTING
822	bool "Paravirtual steal time accounting"
823	depends on PARAVIRT
824	---help---
825	  Select this option to enable fine granularity task steal time
826	  accounting. Time spent executing other tasks in parallel with
827	  the current vCPU is discounted from the vCPU power. To account for
828	  that, there can be a small performance impact.
829
830	  If in doubt, say N here.
831
832config PARAVIRT_CLOCK
833	bool
834
835config JAILHOUSE_GUEST
836	bool "Jailhouse non-root cell support"
837	depends on X86_64 && PCI
838	select X86_PM_TIMER
839	---help---
840	  This option allows to run Linux as guest in a Jailhouse non-root
841	  cell. You can leave this option disabled if you only want to start
842	  Jailhouse and run Linux afterwards in the root cell.
843
844endif #HYPERVISOR_GUEST
845
846source "arch/x86/Kconfig.cpu"
847
848config HPET_TIMER
849	def_bool X86_64
850	prompt "HPET Timer Support" if X86_32
851	---help---
852	  Use the IA-PC HPET (High Precision Event Timer) to manage
853	  time in preference to the PIT and RTC, if a HPET is
854	  present.
855	  HPET is the next generation timer replacing legacy 8254s.
856	  The HPET provides a stable time base on SMP
857	  systems, unlike the TSC, but it is more expensive to access,
858	  as it is off-chip.  The interface used is documented
859	  in the HPET spec, revision 1.
860
861	  You can safely choose Y here.  However, HPET will only be
862	  activated if the platform and the BIOS support this feature.
863	  Otherwise the 8254 will be used for timing services.
864
865	  Choose N to continue using the legacy 8254 timer.
866
867config HPET_EMULATE_RTC
868	def_bool y
869	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
870
871config APB_TIMER
872       def_bool y if X86_INTEL_MID
873       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
874       select DW_APB_TIMER
875       depends on X86_INTEL_MID && SFI
876       help
877         APB timer is the replacement for 8254, HPET on X86 MID platforms.
878         The APBT provides a stable time base on SMP
879         systems, unlike the TSC, but it is more expensive to access,
880         as it is off-chip. APB timers are always running regardless of CPU
881         C states, they are used as per CPU clockevent device when possible.
882
883# Mark as expert because too many people got it wrong.
884# The code disables itself when not needed.
885config DMI
886	default y
887	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
888	bool "Enable DMI scanning" if EXPERT
889	---help---
890	  Enabled scanning of DMI to identify machine quirks. Say Y
891	  here unless you have verified that your setup is not
892	  affected by entries in the DMI blacklist. Required by PNP
893	  BIOS code.
894
895config GART_IOMMU
896	bool "Old AMD GART IOMMU support"
897	select IOMMU_HELPER
898	select SWIOTLB
899	depends on X86_64 && PCI && AMD_NB
900	---help---
901	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
902	  GART based hardware IOMMUs.
903
904	  The GART supports full DMA access for devices with 32-bit access
905	  limitations, on systems with more than 3 GB. This is usually needed
906	  for USB, sound, many IDE/SATA chipsets and some other devices.
907
908	  Newer systems typically have a modern AMD IOMMU, supported via
909	  the CONFIG_AMD_IOMMU=y config option.
910
911	  In normal configurations this driver is only active when needed:
912	  there's more than 3 GB of memory and the system contains a
913	  32-bit limited device.
914
915	  If unsure, say Y.
916
917config CALGARY_IOMMU
918	bool "IBM Calgary IOMMU support"
919	select IOMMU_HELPER
920	select SWIOTLB
921	depends on X86_64 && PCI
922	---help---
923	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
924	  systems. Needed to run systems with more than 3GB of memory
925	  properly with 32-bit PCI devices that do not support DAC
926	  (Double Address Cycle). Calgary also supports bus level
927	  isolation, where all DMAs pass through the IOMMU.  This
928	  prevents them from going anywhere except their intended
929	  destination. This catches hard-to-find kernel bugs and
930	  mis-behaving drivers and devices that do not use the DMA-API
931	  properly to set up their DMA buffers.  The IOMMU can be
932	  turned off at boot time with the iommu=off parameter.
933	  Normally the kernel will make the right choice by itself.
934	  If unsure, say Y.
935
936config CALGARY_IOMMU_ENABLED_BY_DEFAULT
937	def_bool y
938	prompt "Should Calgary be enabled by default?"
939	depends on CALGARY_IOMMU
940	---help---
941	  Should Calgary be enabled by default? if you choose 'y', Calgary
942	  will be used (if it exists). If you choose 'n', Calgary will not be
943	  used even if it exists. If you choose 'n' and would like to use
944	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
945	  If unsure, say Y.
946
947config MAXSMP
948	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
949	depends on X86_64 && SMP && DEBUG_KERNEL
950	select CPUMASK_OFFSTACK
951	---help---
952	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
953	  If unsure, say N.
954
955#
956# The maximum number of CPUs supported:
957#
958# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
959# and which can be configured interactively in the
960# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
961#
962# The ranges are different on 32-bit and 64-bit kernels, depending on
963# hardware capabilities and scalability features of the kernel.
964#
965# ( If MAXSMP is enabled we just use the highest possible value and disable
966#   interactive configuration. )
967#
968
969config NR_CPUS_RANGE_BEGIN
970	int
971	default NR_CPUS_RANGE_END if MAXSMP
972	default    1 if !SMP
973	default    2
974
975config NR_CPUS_RANGE_END
976	int
977	depends on X86_32
978	default   64 if  SMP &&  X86_BIGSMP
979	default    8 if  SMP && !X86_BIGSMP
980	default    1 if !SMP
981
982config NR_CPUS_RANGE_END
983	int
984	depends on X86_64
985	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
986	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
987	default    1 if !SMP
988
989config NR_CPUS_DEFAULT
990	int
991	depends on X86_32
992	default   32 if  X86_BIGSMP
993	default    8 if  SMP
994	default    1 if !SMP
995
996config NR_CPUS_DEFAULT
997	int
998	depends on X86_64
999	default 8192 if  MAXSMP
1000	default   64 if  SMP
1001	default    1 if !SMP
1002
1003config NR_CPUS
1004	int "Maximum number of CPUs" if SMP && !MAXSMP
1005	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1006	default NR_CPUS_DEFAULT
1007	---help---
1008	  This allows you to specify the maximum number of CPUs which this
1009	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1010	  supported value is 8192, otherwise the maximum value is 512.  The
1011	  minimum value which makes sense is 2.
1012
1013	  This is purely to save memory: each supported CPU adds about 8KB
1014	  to the kernel image.
1015
1016config SCHED_SMT
1017	def_bool y if SMP
1018
1019config SCHED_MC
1020	def_bool y
1021	prompt "Multi-core scheduler support"
1022	depends on SMP
1023	---help---
1024	  Multi-core scheduler support improves the CPU scheduler's decision
1025	  making when dealing with multi-core CPU chips at a cost of slightly
1026	  increased overhead in some places. If unsure say N here.
1027
1028config SCHED_MC_PRIO
1029	bool "CPU core priorities scheduler support"
1030	depends on SCHED_MC && CPU_SUP_INTEL
1031	select X86_INTEL_PSTATE
1032	select CPU_FREQ
1033	default y
1034	---help---
1035	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1036	  core ordering determined at manufacturing time, which allows
1037	  certain cores to reach higher turbo frequencies (when running
1038	  single threaded workloads) than others.
1039
1040	  Enabling this kernel feature teaches the scheduler about
1041	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1042	  scheduler's CPU selection logic accordingly, so that higher
1043	  overall system performance can be achieved.
1044
1045	  This feature will have no effect on CPUs without this feature.
1046
1047	  If unsure say Y here.
1048
1049config UP_LATE_INIT
1050       def_bool y
1051       depends on !SMP && X86_LOCAL_APIC
1052
1053config X86_UP_APIC
1054	bool "Local APIC support on uniprocessors" if !PCI_MSI
1055	default PCI_MSI
1056	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1057	---help---
1058	  A local APIC (Advanced Programmable Interrupt Controller) is an
1059	  integrated interrupt controller in the CPU. If you have a single-CPU
1060	  system which has a processor with a local APIC, you can say Y here to
1061	  enable and use it. If you say Y here even though your machine doesn't
1062	  have a local APIC, then the kernel will still run with no slowdown at
1063	  all. The local APIC supports CPU-generated self-interrupts (timer,
1064	  performance counters), and the NMI watchdog which detects hard
1065	  lockups.
1066
1067config X86_UP_IOAPIC
1068	bool "IO-APIC support on uniprocessors"
1069	depends on X86_UP_APIC
1070	---help---
1071	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1072	  SMP-capable replacement for PC-style interrupt controllers. Most
1073	  SMP systems and many recent uniprocessor systems have one.
1074
1075	  If you have a single-CPU system with an IO-APIC, you can say Y here
1076	  to use it. If you say Y here even though your machine doesn't have
1077	  an IO-APIC, then the kernel will still run with no slowdown at all.
1078
1079config X86_LOCAL_APIC
1080	def_bool y
1081	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1082	select IRQ_DOMAIN_HIERARCHY
1083	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1084
1085config X86_IO_APIC
1086	def_bool y
1087	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1088
1089config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1090	bool "Reroute for broken boot IRQs"
1091	depends on X86_IO_APIC
1092	---help---
1093	  This option enables a workaround that fixes a source of
1094	  spurious interrupts. This is recommended when threaded
1095	  interrupt handling is used on systems where the generation of
1096	  superfluous "boot interrupts" cannot be disabled.
1097
1098	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1099	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1100	  kernel does during interrupt handling). On chipsets where this
1101	  boot IRQ generation cannot be disabled, this workaround keeps
1102	  the original IRQ line masked so that only the equivalent "boot
1103	  IRQ" is delivered to the CPUs. The workaround also tells the
1104	  kernel to set up the IRQ handler on the boot IRQ line. In this
1105	  way only one interrupt is delivered to the kernel. Otherwise
1106	  the spurious second interrupt may cause the kernel to bring
1107	  down (vital) interrupt lines.
1108
1109	  Only affects "broken" chipsets. Interrupt sharing may be
1110	  increased on these systems.
1111
1112config X86_MCE
1113	bool "Machine Check / overheating reporting"
1114	select GENERIC_ALLOCATOR
1115	default y
1116	---help---
1117	  Machine Check support allows the processor to notify the
1118	  kernel if it detects a problem (e.g. overheating, data corruption).
1119	  The action the kernel takes depends on the severity of the problem,
1120	  ranging from warning messages to halting the machine.
1121
1122config X86_MCELOG_LEGACY
1123	bool "Support for deprecated /dev/mcelog character device"
1124	depends on X86_MCE
1125	---help---
1126	  Enable support for /dev/mcelog which is needed by the old mcelog
1127	  userspace logging daemon. Consider switching to the new generation
1128	  rasdaemon solution.
1129
1130config X86_MCE_INTEL
1131	def_bool y
1132	prompt "Intel MCE features"
1133	depends on X86_MCE && X86_LOCAL_APIC
1134	---help---
1135	   Additional support for intel specific MCE features such as
1136	   the thermal monitor.
1137
1138config X86_MCE_AMD
1139	def_bool y
1140	prompt "AMD MCE features"
1141	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1142	---help---
1143	   Additional support for AMD specific MCE features such as
1144	   the DRAM Error Threshold.
1145
1146config X86_ANCIENT_MCE
1147	bool "Support for old Pentium 5 / WinChip machine checks"
1148	depends on X86_32 && X86_MCE
1149	---help---
1150	  Include support for machine check handling on old Pentium 5 or WinChip
1151	  systems. These typically need to be enabled explicitly on the command
1152	  line.
1153
1154config X86_MCE_THRESHOLD
1155	depends on X86_MCE_AMD || X86_MCE_INTEL
1156	def_bool y
1157
1158config X86_MCE_INJECT
1159	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1160	tristate "Machine check injector support"
1161	---help---
1162	  Provide support for injecting machine checks for testing purposes.
1163	  If you don't know what a machine check is and you don't do kernel
1164	  QA it is safe to say n.
1165
1166config X86_THERMAL_VECTOR
1167	def_bool y
1168	depends on X86_MCE_INTEL
1169
1170source "arch/x86/events/Kconfig"
1171
1172config X86_LEGACY_VM86
1173	bool "Legacy VM86 support"
1174	depends on X86_32
1175	---help---
1176	  This option allows user programs to put the CPU into V8086
1177	  mode, which is an 80286-era approximation of 16-bit real mode.
1178
1179	  Some very old versions of X and/or vbetool require this option
1180	  for user mode setting.  Similarly, DOSEMU will use it if
1181	  available to accelerate real mode DOS programs.  However, any
1182	  recent version of DOSEMU, X, or vbetool should be fully
1183	  functional even without kernel VM86 support, as they will all
1184	  fall back to software emulation. Nevertheless, if you are using
1185	  a 16-bit DOS program where 16-bit performance matters, vm86
1186	  mode might be faster than emulation and you might want to
1187	  enable this option.
1188
1189	  Note that any app that works on a 64-bit kernel is unlikely to
1190	  need this option, as 64-bit kernels don't, and can't, support
1191	  V8086 mode. This option is also unrelated to 16-bit protected
1192	  mode and is not needed to run most 16-bit programs under Wine.
1193
1194	  Enabling this option increases the complexity of the kernel
1195	  and slows down exception handling a tiny bit.
1196
1197	  If unsure, say N here.
1198
1199config VM86
1200       bool
1201       default X86_LEGACY_VM86
1202
1203config X86_16BIT
1204	bool "Enable support for 16-bit segments" if EXPERT
1205	default y
1206	depends on MODIFY_LDT_SYSCALL
1207	---help---
1208	  This option is required by programs like Wine to run 16-bit
1209	  protected mode legacy code on x86 processors.  Disabling
1210	  this option saves about 300 bytes on i386, or around 6K text
1211	  plus 16K runtime memory on x86-64,
1212
1213config X86_ESPFIX32
1214	def_bool y
1215	depends on X86_16BIT && X86_32
1216
1217config X86_ESPFIX64
1218	def_bool y
1219	depends on X86_16BIT && X86_64
1220
1221config X86_VSYSCALL_EMULATION
1222       bool "Enable vsyscall emulation" if EXPERT
1223       default y
1224       depends on X86_64
1225       ---help---
1226	 This enables emulation of the legacy vsyscall page.  Disabling
1227	 it is roughly equivalent to booting with vsyscall=none, except
1228	 that it will also disable the helpful warning if a program
1229	 tries to use a vsyscall.  With this option set to N, offending
1230	 programs will just segfault, citing addresses of the form
1231	 0xffffffffff600?00.
1232
1233	 This option is required by many programs built before 2013, and
1234	 care should be used even with newer programs if set to N.
1235
1236	 Disabling this option saves about 7K of kernel size and
1237	 possibly 4K of additional runtime pagetable memory.
1238
1239config TOSHIBA
1240	tristate "Toshiba Laptop support"
1241	depends on X86_32
1242	---help---
1243	  This adds a driver to safely access the System Management Mode of
1244	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1245	  not work on models with a Phoenix BIOS. The System Management Mode
1246	  is used to set the BIOS and power saving options on Toshiba portables.
1247
1248	  For information on utilities to make use of this driver see the
1249	  Toshiba Linux utilities web site at:
1250	  <http://www.buzzard.org.uk/toshiba/>.
1251
1252	  Say Y if you intend to run this kernel on a Toshiba portable.
1253	  Say N otherwise.
1254
1255config I8K
1256	tristate "Dell i8k legacy laptop support"
1257	select HWMON
1258	select SENSORS_DELL_SMM
1259	---help---
1260	  This option enables legacy /proc/i8k userspace interface in hwmon
1261	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1262	  temperature and allows controlling fan speeds of Dell laptops via
1263	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1264	  it reports also power and hotkey status. For fan speed control is
1265	  needed userspace package i8kutils.
1266
1267	  Say Y if you intend to run this kernel on old Dell laptops or want to
1268	  use userspace package i8kutils.
1269	  Say N otherwise.
1270
1271config X86_REBOOTFIXUPS
1272	bool "Enable X86 board specific fixups for reboot"
1273	depends on X86_32
1274	---help---
1275	  This enables chipset and/or board specific fixups to be done
1276	  in order to get reboot to work correctly. This is only needed on
1277	  some combinations of hardware and BIOS. The symptom, for which
1278	  this config is intended, is when reboot ends with a stalled/hung
1279	  system.
1280
1281	  Currently, the only fixup is for the Geode machines using
1282	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1283
1284	  Say Y if you want to enable the fixup. Currently, it's safe to
1285	  enable this option even if you don't need it.
1286	  Say N otherwise.
1287
1288config MICROCODE
1289	bool "CPU microcode loading support"
1290	default y
1291	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1292	select FW_LOADER
1293	---help---
1294	  If you say Y here, you will be able to update the microcode on
1295	  Intel and AMD processors. The Intel support is for the IA32 family,
1296	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1297	  AMD support is for families 0x10 and later. You will obviously need
1298	  the actual microcode binary data itself which is not shipped with
1299	  the Linux kernel.
1300
1301	  The preferred method to load microcode from a detached initrd is described
1302	  in Documentation/x86/microcode.txt. For that you need to enable
1303	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1304	  initrd for microcode blobs.
1305
1306	  In addition, you can build the microcode into the kernel. For that you
1307	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1308	  config option.
1309
1310config MICROCODE_INTEL
1311	bool "Intel microcode loading support"
1312	depends on MICROCODE
1313	default MICROCODE
1314	select FW_LOADER
1315	---help---
1316	  This options enables microcode patch loading support for Intel
1317	  processors.
1318
1319	  For the current Intel microcode data package go to
1320	  <https://downloadcenter.intel.com> and search for
1321	  'Linux Processor Microcode Data File'.
1322
1323config MICROCODE_AMD
1324	bool "AMD microcode loading support"
1325	depends on MICROCODE
1326	select FW_LOADER
1327	---help---
1328	  If you select this option, microcode patch loading support for AMD
1329	  processors will be enabled.
1330
1331config MICROCODE_OLD_INTERFACE
1332	def_bool y
1333	depends on MICROCODE
1334
1335config X86_MSR
1336	tristate "/dev/cpu/*/msr - Model-specific register support"
1337	---help---
1338	  This device gives privileged processes access to the x86
1339	  Model-Specific Registers (MSRs).  It is a character device with
1340	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1341	  MSR accesses are directed to a specific CPU on multi-processor
1342	  systems.
1343
1344config X86_CPUID
1345	tristate "/dev/cpu/*/cpuid - CPU information support"
1346	---help---
1347	  This device gives processes access to the x86 CPUID instruction to
1348	  be executed on a specific processor.  It is a character device
1349	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1350	  /dev/cpu/31/cpuid.
1351
1352choice
1353	prompt "High Memory Support"
1354	default HIGHMEM4G
1355	depends on X86_32
1356
1357config NOHIGHMEM
1358	bool "off"
1359	---help---
1360	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1361	  However, the address space of 32-bit x86 processors is only 4
1362	  Gigabytes large. That means that, if you have a large amount of
1363	  physical memory, not all of it can be "permanently mapped" by the
1364	  kernel. The physical memory that's not permanently mapped is called
1365	  "high memory".
1366
1367	  If you are compiling a kernel which will never run on a machine with
1368	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1369	  choice and suitable for most users). This will result in a "3GB/1GB"
1370	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1371	  space and the remaining part of the 4GB virtual memory space is used
1372	  by the kernel to permanently map as much physical memory as
1373	  possible.
1374
1375	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1376	  answer "4GB" here.
1377
1378	  If more than 4 Gigabytes is used then answer "64GB" here. This
1379	  selection turns Intel PAE (Physical Address Extension) mode on.
1380	  PAE implements 3-level paging on IA32 processors. PAE is fully
1381	  supported by Linux, PAE mode is implemented on all recent Intel
1382	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1383	  then the kernel will not boot on CPUs that don't support PAE!
1384
1385	  The actual amount of total physical memory will either be
1386	  auto detected or can be forced by using a kernel command line option
1387	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1388	  your boot loader (lilo or loadlin) about how to pass options to the
1389	  kernel at boot time.)
1390
1391	  If unsure, say "off".
1392
1393config HIGHMEM4G
1394	bool "4GB"
1395	---help---
1396	  Select this if you have a 32-bit processor and between 1 and 4
1397	  gigabytes of physical RAM.
1398
1399config HIGHMEM64G
1400	bool "64GB"
1401	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1402	select X86_PAE
1403	---help---
1404	  Select this if you have a 32-bit processor and more than 4
1405	  gigabytes of physical RAM.
1406
1407endchoice
1408
1409choice
1410	prompt "Memory split" if EXPERT
1411	default VMSPLIT_3G
1412	depends on X86_32
1413	---help---
1414	  Select the desired split between kernel and user memory.
1415
1416	  If the address range available to the kernel is less than the
1417	  physical memory installed, the remaining memory will be available
1418	  as "high memory". Accessing high memory is a little more costly
1419	  than low memory, as it needs to be mapped into the kernel first.
1420	  Note that increasing the kernel address space limits the range
1421	  available to user programs, making the address space there
1422	  tighter.  Selecting anything other than the default 3G/1G split
1423	  will also likely make your kernel incompatible with binary-only
1424	  kernel modules.
1425
1426	  If you are not absolutely sure what you are doing, leave this
1427	  option alone!
1428
1429	config VMSPLIT_3G
1430		bool "3G/1G user/kernel split"
1431	config VMSPLIT_3G_OPT
1432		depends on !X86_PAE
1433		bool "3G/1G user/kernel split (for full 1G low memory)"
1434	config VMSPLIT_2G
1435		bool "2G/2G user/kernel split"
1436	config VMSPLIT_2G_OPT
1437		depends on !X86_PAE
1438		bool "2G/2G user/kernel split (for full 2G low memory)"
1439	config VMSPLIT_1G
1440		bool "1G/3G user/kernel split"
1441endchoice
1442
1443config PAGE_OFFSET
1444	hex
1445	default 0xB0000000 if VMSPLIT_3G_OPT
1446	default 0x80000000 if VMSPLIT_2G
1447	default 0x78000000 if VMSPLIT_2G_OPT
1448	default 0x40000000 if VMSPLIT_1G
1449	default 0xC0000000
1450	depends on X86_32
1451
1452config HIGHMEM
1453	def_bool y
1454	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1455
1456config X86_PAE
1457	bool "PAE (Physical Address Extension) Support"
1458	depends on X86_32 && !HIGHMEM4G
1459	select PHYS_ADDR_T_64BIT
1460	select SWIOTLB
1461	---help---
1462	  PAE is required for NX support, and furthermore enables
1463	  larger swapspace support for non-overcommit purposes. It
1464	  has the cost of more pagetable lookup overhead, and also
1465	  consumes more pagetable space per process.
1466
1467config X86_5LEVEL
1468	bool "Enable 5-level page tables support"
1469	select DYNAMIC_MEMORY_LAYOUT
1470	select SPARSEMEM_VMEMMAP
1471	depends on X86_64
1472	---help---
1473	  5-level paging enables access to larger address space:
1474	  upto 128 PiB of virtual address space and 4 PiB of
1475	  physical address space.
1476
1477	  It will be supported by future Intel CPUs.
1478
1479	  A kernel with the option enabled can be booted on machines that
1480	  support 4- or 5-level paging.
1481
1482	  See Documentation/x86/x86_64/5level-paging.txt for more
1483	  information.
1484
1485	  Say N if unsure.
1486
1487config X86_DIRECT_GBPAGES
1488	def_bool y
1489	depends on X86_64 && !DEBUG_PAGEALLOC
1490	---help---
1491	  Certain kernel features effectively disable kernel
1492	  linear 1 GB mappings (even if the CPU otherwise
1493	  supports them), so don't confuse the user by printing
1494	  that we have them enabled.
1495
1496config X86_CPA_STATISTICS
1497	bool "Enable statistic for Change Page Attribute"
1498	depends on DEBUG_FS
1499	---help---
1500	  Expose statistics about the Change Page Attribute mechanims, which
1501	  helps to determine the effectivness of preserving large and huge
1502	  page mappings when mapping protections are changed.
1503
1504config ARCH_HAS_MEM_ENCRYPT
1505	def_bool y
1506
1507config AMD_MEM_ENCRYPT
1508	bool "AMD Secure Memory Encryption (SME) support"
1509	depends on X86_64 && CPU_SUP_AMD
1510	select DYNAMIC_PHYSICAL_MASK
1511	---help---
1512	  Say yes to enable support for the encryption of system memory.
1513	  This requires an AMD processor that supports Secure Memory
1514	  Encryption (SME).
1515
1516config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1517	bool "Activate AMD Secure Memory Encryption (SME) by default"
1518	default y
1519	depends on AMD_MEM_ENCRYPT
1520	---help---
1521	  Say yes to have system memory encrypted by default if running on
1522	  an AMD processor that supports Secure Memory Encryption (SME).
1523
1524	  If set to Y, then the encryption of system memory can be
1525	  deactivated with the mem_encrypt=off command line option.
1526
1527	  If set to N, then the encryption of system memory can be
1528	  activated with the mem_encrypt=on command line option.
1529
1530config ARCH_USE_MEMREMAP_PROT
1531	def_bool y
1532	depends on AMD_MEM_ENCRYPT
1533
1534# Common NUMA Features
1535config NUMA
1536	bool "Numa Memory Allocation and Scheduler Support"
1537	depends on SMP
1538	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1539	default y if X86_BIGSMP
1540	---help---
1541	  Enable NUMA (Non Uniform Memory Access) support.
1542
1543	  The kernel will try to allocate memory used by a CPU on the
1544	  local memory controller of the CPU and add some more
1545	  NUMA awareness to the kernel.
1546
1547	  For 64-bit this is recommended if the system is Intel Core i7
1548	  (or later), AMD Opteron, or EM64T NUMA.
1549
1550	  For 32-bit this is only needed if you boot a 32-bit
1551	  kernel on a 64-bit NUMA platform.
1552
1553	  Otherwise, you should say N.
1554
1555config AMD_NUMA
1556	def_bool y
1557	prompt "Old style AMD Opteron NUMA detection"
1558	depends on X86_64 && NUMA && PCI
1559	---help---
1560	  Enable AMD NUMA node topology detection.  You should say Y here if
1561	  you have a multi processor AMD system. This uses an old method to
1562	  read the NUMA configuration directly from the builtin Northbridge
1563	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1564	  which also takes priority if both are compiled in.
1565
1566config X86_64_ACPI_NUMA
1567	def_bool y
1568	prompt "ACPI NUMA detection"
1569	depends on X86_64 && NUMA && ACPI && PCI
1570	select ACPI_NUMA
1571	---help---
1572	  Enable ACPI SRAT based node topology detection.
1573
1574# Some NUMA nodes have memory ranges that span
1575# other nodes.  Even though a pfn is valid and
1576# between a node's start and end pfns, it may not
1577# reside on that node.  See memmap_init_zone()
1578# for details.
1579config NODES_SPAN_OTHER_NODES
1580	def_bool y
1581	depends on X86_64_ACPI_NUMA
1582
1583config NUMA_EMU
1584	bool "NUMA emulation"
1585	depends on NUMA
1586	---help---
1587	  Enable NUMA emulation. A flat machine will be split
1588	  into virtual nodes when booted with "numa=fake=N", where N is the
1589	  number of nodes. This is only useful for debugging.
1590
1591config NODES_SHIFT
1592	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1593	range 1 10
1594	default "10" if MAXSMP
1595	default "6" if X86_64
1596	default "3"
1597	depends on NEED_MULTIPLE_NODES
1598	---help---
1599	  Specify the maximum number of NUMA Nodes available on the target
1600	  system.  Increases memory reserved to accommodate various tables.
1601
1602config ARCH_HAVE_MEMORY_PRESENT
1603	def_bool y
1604	depends on X86_32 && DISCONTIGMEM
1605
1606config ARCH_FLATMEM_ENABLE
1607	def_bool y
1608	depends on X86_32 && !NUMA
1609
1610config ARCH_DISCONTIGMEM_ENABLE
1611	def_bool y
1612	depends on NUMA && X86_32
1613
1614config ARCH_DISCONTIGMEM_DEFAULT
1615	def_bool y
1616	depends on NUMA && X86_32
1617
1618config ARCH_SPARSEMEM_ENABLE
1619	def_bool y
1620	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1621	select SPARSEMEM_STATIC if X86_32
1622	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1623
1624config ARCH_SPARSEMEM_DEFAULT
1625	def_bool y
1626	depends on X86_64
1627
1628config ARCH_SELECT_MEMORY_MODEL
1629	def_bool y
1630	depends on ARCH_SPARSEMEM_ENABLE
1631
1632config ARCH_MEMORY_PROBE
1633	bool "Enable sysfs memory/probe interface"
1634	depends on X86_64 && MEMORY_HOTPLUG
1635	help
1636	  This option enables a sysfs memory/probe interface for testing.
1637	  See Documentation/memory-hotplug.txt for more information.
1638	  If you are unsure how to answer this question, answer N.
1639
1640config ARCH_PROC_KCORE_TEXT
1641	def_bool y
1642	depends on X86_64 && PROC_KCORE
1643
1644config ILLEGAL_POINTER_VALUE
1645       hex
1646       default 0 if X86_32
1647       default 0xdead000000000000 if X86_64
1648
1649config X86_PMEM_LEGACY_DEVICE
1650	bool
1651
1652config X86_PMEM_LEGACY
1653	tristate "Support non-standard NVDIMMs and ADR protected memory"
1654	depends on PHYS_ADDR_T_64BIT
1655	depends on BLK_DEV
1656	select X86_PMEM_LEGACY_DEVICE
1657	select LIBNVDIMM
1658	help
1659	  Treat memory marked using the non-standard e820 type of 12 as used
1660	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1661	  The kernel will offer these regions to the 'pmem' driver so
1662	  they can be used for persistent storage.
1663
1664	  Say Y if unsure.
1665
1666config HIGHPTE
1667	bool "Allocate 3rd-level pagetables from highmem"
1668	depends on HIGHMEM
1669	---help---
1670	  The VM uses one page table entry for each page of physical memory.
1671	  For systems with a lot of RAM, this can be wasteful of precious
1672	  low memory.  Setting this option will put user-space page table
1673	  entries in high memory.
1674
1675config X86_CHECK_BIOS_CORRUPTION
1676	bool "Check for low memory corruption"
1677	---help---
1678	  Periodically check for memory corruption in low memory, which
1679	  is suspected to be caused by BIOS.  Even when enabled in the
1680	  configuration, it is disabled at runtime.  Enable it by
1681	  setting "memory_corruption_check=1" on the kernel command
1682	  line.  By default it scans the low 64k of memory every 60
1683	  seconds; see the memory_corruption_check_size and
1684	  memory_corruption_check_period parameters in
1685	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1686
1687	  When enabled with the default parameters, this option has
1688	  almost no overhead, as it reserves a relatively small amount
1689	  of memory and scans it infrequently.  It both detects corruption
1690	  and prevents it from affecting the running system.
1691
1692	  It is, however, intended as a diagnostic tool; if repeatable
1693	  BIOS-originated corruption always affects the same memory,
1694	  you can use memmap= to prevent the kernel from using that
1695	  memory.
1696
1697config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1698	bool "Set the default setting of memory_corruption_check"
1699	depends on X86_CHECK_BIOS_CORRUPTION
1700	default y
1701	---help---
1702	  Set whether the default state of memory_corruption_check is
1703	  on or off.
1704
1705config X86_RESERVE_LOW
1706	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1707	default 64
1708	range 4 640
1709	---help---
1710	  Specify the amount of low memory to reserve for the BIOS.
1711
1712	  The first page contains BIOS data structures that the kernel
1713	  must not use, so that page must always be reserved.
1714
1715	  By default we reserve the first 64K of physical RAM, as a
1716	  number of BIOSes are known to corrupt that memory range
1717	  during events such as suspend/resume or monitor cable
1718	  insertion, so it must not be used by the kernel.
1719
1720	  You can set this to 4 if you are absolutely sure that you
1721	  trust the BIOS to get all its memory reservations and usages
1722	  right.  If you know your BIOS have problems beyond the
1723	  default 64K area, you can set this to 640 to avoid using the
1724	  entire low memory range.
1725
1726	  If you have doubts about the BIOS (e.g. suspend/resume does
1727	  not work or there's kernel crashes after certain hardware
1728	  hotplug events) then you might want to enable
1729	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1730	  typical corruption patterns.
1731
1732	  Leave this to the default value of 64 if you are unsure.
1733
1734config MATH_EMULATION
1735	bool
1736	depends on MODIFY_LDT_SYSCALL
1737	prompt "Math emulation" if X86_32
1738	---help---
1739	  Linux can emulate a math coprocessor (used for floating point
1740	  operations) if you don't have one. 486DX and Pentium processors have
1741	  a math coprocessor built in, 486SX and 386 do not, unless you added
1742	  a 487DX or 387, respectively. (The messages during boot time can
1743	  give you some hints here ["man dmesg"].) Everyone needs either a
1744	  coprocessor or this emulation.
1745
1746	  If you don't have a math coprocessor, you need to say Y here; if you
1747	  say Y here even though you have a coprocessor, the coprocessor will
1748	  be used nevertheless. (This behavior can be changed with the kernel
1749	  command line option "no387", which comes handy if your coprocessor
1750	  is broken. Try "man bootparam" or see the documentation of your boot
1751	  loader (lilo or loadlin) about how to pass options to the kernel at
1752	  boot time.) This means that it is a good idea to say Y here if you
1753	  intend to use this kernel on different machines.
1754
1755	  More information about the internals of the Linux math coprocessor
1756	  emulation can be found in <file:arch/x86/math-emu/README>.
1757
1758	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1759	  kernel, it won't hurt.
1760
1761config MTRR
1762	def_bool y
1763	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1764	---help---
1765	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1766	  the Memory Type Range Registers (MTRRs) may be used to control
1767	  processor access to memory ranges. This is most useful if you have
1768	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1769	  allows bus write transfers to be combined into a larger transfer
1770	  before bursting over the PCI/AGP bus. This can increase performance
1771	  of image write operations 2.5 times or more. Saying Y here creates a
1772	  /proc/mtrr file which may be used to manipulate your processor's
1773	  MTRRs. Typically the X server should use this.
1774
1775	  This code has a reasonably generic interface so that similar
1776	  control registers on other processors can be easily supported
1777	  as well:
1778
1779	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1780	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1781	  these, the ARRs are used to emulate the MTRRs.
1782	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1783	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1784	  write-combining. All of these processors are supported by this code
1785	  and it makes sense to say Y here if you have one of them.
1786
1787	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1788	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1789	  can lead to all sorts of problems, so it's good to say Y here.
1790
1791	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1792	  just add about 9 KB to your kernel.
1793
1794	  See <file:Documentation/x86/mtrr.txt> for more information.
1795
1796config MTRR_SANITIZER
1797	def_bool y
1798	prompt "MTRR cleanup support"
1799	depends on MTRR
1800	---help---
1801	  Convert MTRR layout from continuous to discrete, so X drivers can
1802	  add writeback entries.
1803
1804	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1805	  The largest mtrr entry size for a continuous block can be set with
1806	  mtrr_chunk_size.
1807
1808	  If unsure, say Y.
1809
1810config MTRR_SANITIZER_ENABLE_DEFAULT
1811	int "MTRR cleanup enable value (0-1)"
1812	range 0 1
1813	default "0"
1814	depends on MTRR_SANITIZER
1815	---help---
1816	  Enable mtrr cleanup default value
1817
1818config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1819	int "MTRR cleanup spare reg num (0-7)"
1820	range 0 7
1821	default "1"
1822	depends on MTRR_SANITIZER
1823	---help---
1824	  mtrr cleanup spare entries default, it can be changed via
1825	  mtrr_spare_reg_nr=N on the kernel command line.
1826
1827config X86_PAT
1828	def_bool y
1829	prompt "x86 PAT support" if EXPERT
1830	depends on MTRR
1831	---help---
1832	  Use PAT attributes to setup page level cache control.
1833
1834	  PATs are the modern equivalents of MTRRs and are much more
1835	  flexible than MTRRs.
1836
1837	  Say N here if you see bootup problems (boot crash, boot hang,
1838	  spontaneous reboots) or a non-working video driver.
1839
1840	  If unsure, say Y.
1841
1842config ARCH_USES_PG_UNCACHED
1843	def_bool y
1844	depends on X86_PAT
1845
1846config ARCH_RANDOM
1847	def_bool y
1848	prompt "x86 architectural random number generator" if EXPERT
1849	---help---
1850	  Enable the x86 architectural RDRAND instruction
1851	  (Intel Bull Mountain technology) to generate random numbers.
1852	  If supported, this is a high bandwidth, cryptographically
1853	  secure hardware random number generator.
1854
1855config X86_SMAP
1856	def_bool y
1857	prompt "Supervisor Mode Access Prevention" if EXPERT
1858	---help---
1859	  Supervisor Mode Access Prevention (SMAP) is a security
1860	  feature in newer Intel processors.  There is a small
1861	  performance cost if this enabled and turned on; there is
1862	  also a small increase in the kernel size if this is enabled.
1863
1864	  If unsure, say Y.
1865
1866config X86_INTEL_UMIP
1867	def_bool y
1868	depends on CPU_SUP_INTEL
1869	prompt "Intel User Mode Instruction Prevention" if EXPERT
1870	---help---
1871	  The User Mode Instruction Prevention (UMIP) is a security
1872	  feature in newer Intel processors. If enabled, a general
1873	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1874	  or STR instructions are executed in user mode. These instructions
1875	  unnecessarily expose information about the hardware state.
1876
1877	  The vast majority of applications do not use these instructions.
1878	  For the very few that do, software emulation is provided in
1879	  specific cases in protected and virtual-8086 modes. Emulated
1880	  results are dummy.
1881
1882config X86_INTEL_MPX
1883	prompt "Intel MPX (Memory Protection Extensions)"
1884	def_bool n
1885	# Note: only available in 64-bit mode due to VMA flags shortage
1886	depends on CPU_SUP_INTEL && X86_64
1887	select ARCH_USES_HIGH_VMA_FLAGS
1888	---help---
1889	  MPX provides hardware features that can be used in
1890	  conjunction with compiler-instrumented code to check
1891	  memory references.  It is designed to detect buffer
1892	  overflow or underflow bugs.
1893
1894	  This option enables running applications which are
1895	  instrumented or otherwise use MPX.  It does not use MPX
1896	  itself inside the kernel or to protect the kernel
1897	  against bad memory references.
1898
1899	  Enabling this option will make the kernel larger:
1900	  ~8k of kernel text and 36 bytes of data on a 64-bit
1901	  defconfig.  It adds a long to the 'mm_struct' which
1902	  will increase the kernel memory overhead of each
1903	  process and adds some branches to paths used during
1904	  exec() and munmap().
1905
1906	  For details, see Documentation/x86/intel_mpx.txt
1907
1908	  If unsure, say N.
1909
1910config X86_INTEL_MEMORY_PROTECTION_KEYS
1911	prompt "Intel Memory Protection Keys"
1912	def_bool y
1913	# Note: only available in 64-bit mode
1914	depends on CPU_SUP_INTEL && X86_64
1915	select ARCH_USES_HIGH_VMA_FLAGS
1916	select ARCH_HAS_PKEYS
1917	---help---
1918	  Memory Protection Keys provides a mechanism for enforcing
1919	  page-based protections, but without requiring modification of the
1920	  page tables when an application changes protection domains.
1921
1922	  For details, see Documentation/x86/protection-keys.txt
1923
1924	  If unsure, say y.
1925
1926config EFI
1927	bool "EFI runtime service support"
1928	depends on ACPI
1929	select UCS2_STRING
1930	select EFI_RUNTIME_WRAPPERS
1931	---help---
1932	  This enables the kernel to use EFI runtime services that are
1933	  available (such as the EFI variable services).
1934
1935	  This option is only useful on systems that have EFI firmware.
1936	  In addition, you should use the latest ELILO loader available
1937	  at <http://elilo.sourceforge.net> in order to take advantage
1938	  of EFI runtime services. However, even with this option, the
1939	  resultant kernel should continue to boot on existing non-EFI
1940	  platforms.
1941
1942config EFI_STUB
1943       bool "EFI stub support"
1944       depends on EFI && !X86_USE_3DNOW
1945       select RELOCATABLE
1946       ---help---
1947          This kernel feature allows a bzImage to be loaded directly
1948	  by EFI firmware without the use of a bootloader.
1949
1950	  See Documentation/efi-stub.txt for more information.
1951
1952config EFI_MIXED
1953	bool "EFI mixed-mode support"
1954	depends on EFI_STUB && X86_64
1955	---help---
1956	   Enabling this feature allows a 64-bit kernel to be booted
1957	   on a 32-bit firmware, provided that your CPU supports 64-bit
1958	   mode.
1959
1960	   Note that it is not possible to boot a mixed-mode enabled
1961	   kernel via the EFI boot stub - a bootloader that supports
1962	   the EFI handover protocol must be used.
1963
1964	   If unsure, say N.
1965
1966config SECCOMP
1967	def_bool y
1968	prompt "Enable seccomp to safely compute untrusted bytecode"
1969	---help---
1970	  This kernel feature is useful for number crunching applications
1971	  that may need to compute untrusted bytecode during their
1972	  execution. By using pipes or other transports made available to
1973	  the process as file descriptors supporting the read/write
1974	  syscalls, it's possible to isolate those applications in
1975	  their own address space using seccomp. Once seccomp is
1976	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1977	  and the task is only allowed to execute a few safe syscalls
1978	  defined by each seccomp mode.
1979
1980	  If unsure, say Y. Only embedded should say N here.
1981
1982source kernel/Kconfig.hz
1983
1984config KEXEC
1985	bool "kexec system call"
1986	select KEXEC_CORE
1987	---help---
1988	  kexec is a system call that implements the ability to shutdown your
1989	  current kernel, and to start another kernel.  It is like a reboot
1990	  but it is independent of the system firmware.   And like a reboot
1991	  you can start any kernel with it, not just Linux.
1992
1993	  The name comes from the similarity to the exec system call.
1994
1995	  It is an ongoing process to be certain the hardware in a machine
1996	  is properly shutdown, so do not be surprised if this code does not
1997	  initially work for you.  As of this writing the exact hardware
1998	  interface is strongly in flux, so no good recommendation can be
1999	  made.
2000
2001config KEXEC_FILE
2002	bool "kexec file based system call"
2003	select KEXEC_CORE
2004	select BUILD_BIN2C
2005	depends on X86_64
2006	depends on CRYPTO=y
2007	depends on CRYPTO_SHA256=y
2008	---help---
2009	  This is new version of kexec system call. This system call is
2010	  file based and takes file descriptors as system call argument
2011	  for kernel and initramfs as opposed to list of segments as
2012	  accepted by previous system call.
2013
2014config ARCH_HAS_KEXEC_PURGATORY
2015	def_bool KEXEC_FILE
2016
2017config KEXEC_VERIFY_SIG
2018	bool "Verify kernel signature during kexec_file_load() syscall"
2019	depends on KEXEC_FILE
2020	---help---
2021	  This option makes kernel signature verification mandatory for
2022	  the kexec_file_load() syscall.
2023
2024	  In addition to that option, you need to enable signature
2025	  verification for the corresponding kernel image type being
2026	  loaded in order for this to work.
2027
2028config KEXEC_BZIMAGE_VERIFY_SIG
2029	bool "Enable bzImage signature verification support"
2030	depends on KEXEC_VERIFY_SIG
2031	depends on SIGNED_PE_FILE_VERIFICATION
2032	select SYSTEM_TRUSTED_KEYRING
2033	---help---
2034	  Enable bzImage signature verification support.
2035
2036config CRASH_DUMP
2037	bool "kernel crash dumps"
2038	depends on X86_64 || (X86_32 && HIGHMEM)
2039	---help---
2040	  Generate crash dump after being started by kexec.
2041	  This should be normally only set in special crash dump kernels
2042	  which are loaded in the main kernel with kexec-tools into
2043	  a specially reserved region and then later executed after
2044	  a crash by kdump/kexec. The crash dump kernel must be compiled
2045	  to a memory address not used by the main kernel or BIOS using
2046	  PHYSICAL_START, or it must be built as a relocatable image
2047	  (CONFIG_RELOCATABLE=y).
2048	  For more details see Documentation/kdump/kdump.txt
2049
2050config KEXEC_JUMP
2051	bool "kexec jump"
2052	depends on KEXEC && HIBERNATION
2053	---help---
2054	  Jump between original kernel and kexeced kernel and invoke
2055	  code in physical address mode via KEXEC
2056
2057config PHYSICAL_START
2058	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2059	default "0x1000000"
2060	---help---
2061	  This gives the physical address where the kernel is loaded.
2062
2063	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2064	  bzImage will decompress itself to above physical address and
2065	  run from there. Otherwise, bzImage will run from the address where
2066	  it has been loaded by the boot loader and will ignore above physical
2067	  address.
2068
2069	  In normal kdump cases one does not have to set/change this option
2070	  as now bzImage can be compiled as a completely relocatable image
2071	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2072	  address. This option is mainly useful for the folks who don't want
2073	  to use a bzImage for capturing the crash dump and want to use a
2074	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2075	  to be specifically compiled to run from a specific memory area
2076	  (normally a reserved region) and this option comes handy.
2077
2078	  So if you are using bzImage for capturing the crash dump,
2079	  leave the value here unchanged to 0x1000000 and set
2080	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2081	  for capturing the crash dump change this value to start of
2082	  the reserved region.  In other words, it can be set based on
2083	  the "X" value as specified in the "crashkernel=YM@XM"
2084	  command line boot parameter passed to the panic-ed
2085	  kernel. Please take a look at Documentation/kdump/kdump.txt
2086	  for more details about crash dumps.
2087
2088	  Usage of bzImage for capturing the crash dump is recommended as
2089	  one does not have to build two kernels. Same kernel can be used
2090	  as production kernel and capture kernel. Above option should have
2091	  gone away after relocatable bzImage support is introduced. But it
2092	  is present because there are users out there who continue to use
2093	  vmlinux for dump capture. This option should go away down the
2094	  line.
2095
2096	  Don't change this unless you know what you are doing.
2097
2098config RELOCATABLE
2099	bool "Build a relocatable kernel"
2100	default y
2101	---help---
2102	  This builds a kernel image that retains relocation information
2103	  so it can be loaded someplace besides the default 1MB.
2104	  The relocations tend to make the kernel binary about 10% larger,
2105	  but are discarded at runtime.
2106
2107	  One use is for the kexec on panic case where the recovery kernel
2108	  must live at a different physical address than the primary
2109	  kernel.
2110
2111	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2112	  it has been loaded at and the compile time physical address
2113	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2114
2115config RANDOMIZE_BASE
2116	bool "Randomize the address of the kernel image (KASLR)"
2117	depends on RELOCATABLE
2118	default y
2119	---help---
2120	  In support of Kernel Address Space Layout Randomization (KASLR),
2121	  this randomizes the physical address at which the kernel image
2122	  is decompressed and the virtual address where the kernel
2123	  image is mapped, as a security feature that deters exploit
2124	  attempts relying on knowledge of the location of kernel
2125	  code internals.
2126
2127	  On 64-bit, the kernel physical and virtual addresses are
2128	  randomized separately. The physical address will be anywhere
2129	  between 16MB and the top of physical memory (up to 64TB). The
2130	  virtual address will be randomized from 16MB up to 1GB (9 bits
2131	  of entropy). Note that this also reduces the memory space
2132	  available to kernel modules from 1.5GB to 1GB.
2133
2134	  On 32-bit, the kernel physical and virtual addresses are
2135	  randomized together. They will be randomized from 16MB up to
2136	  512MB (8 bits of entropy).
2137
2138	  Entropy is generated using the RDRAND instruction if it is
2139	  supported. If RDTSC is supported, its value is mixed into
2140	  the entropy pool as well. If neither RDRAND nor RDTSC are
2141	  supported, then entropy is read from the i8254 timer. The
2142	  usable entropy is limited by the kernel being built using
2143	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2144	  minimum of 2MB. As a result, only 10 bits of entropy are
2145	  theoretically possible, but the implementations are further
2146	  limited due to memory layouts.
2147
2148	  If unsure, say Y.
2149
2150# Relocation on x86 needs some additional build support
2151config X86_NEED_RELOCS
2152	def_bool y
2153	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2154
2155config PHYSICAL_ALIGN
2156	hex "Alignment value to which kernel should be aligned"
2157	default "0x200000"
2158	range 0x2000 0x1000000 if X86_32
2159	range 0x200000 0x1000000 if X86_64
2160	---help---
2161	  This value puts the alignment restrictions on physical address
2162	  where kernel is loaded and run from. Kernel is compiled for an
2163	  address which meets above alignment restriction.
2164
2165	  If bootloader loads the kernel at a non-aligned address and
2166	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2167	  address aligned to above value and run from there.
2168
2169	  If bootloader loads the kernel at a non-aligned address and
2170	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2171	  load address and decompress itself to the address it has been
2172	  compiled for and run from there. The address for which kernel is
2173	  compiled already meets above alignment restrictions. Hence the
2174	  end result is that kernel runs from a physical address meeting
2175	  above alignment restrictions.
2176
2177	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2178	  this value must be a multiple of 0x200000.
2179
2180	  Don't change this unless you know what you are doing.
2181
2182config DYNAMIC_MEMORY_LAYOUT
2183	bool
2184	---help---
2185	  This option makes base addresses of vmalloc and vmemmap as well as
2186	  __PAGE_OFFSET movable during boot.
2187
2188config RANDOMIZE_MEMORY
2189	bool "Randomize the kernel memory sections"
2190	depends on X86_64
2191	depends on RANDOMIZE_BASE
2192	select DYNAMIC_MEMORY_LAYOUT
2193	default RANDOMIZE_BASE
2194	---help---
2195	   Randomizes the base virtual address of kernel memory sections
2196	   (physical memory mapping, vmalloc & vmemmap). This security feature
2197	   makes exploits relying on predictable memory locations less reliable.
2198
2199	   The order of allocations remains unchanged. Entropy is generated in
2200	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2201	   configuration have in average 30,000 different possible virtual
2202	   addresses for each memory section.
2203
2204	   If unsure, say Y.
2205
2206config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2207	hex "Physical memory mapping padding" if EXPERT
2208	depends on RANDOMIZE_MEMORY
2209	default "0xa" if MEMORY_HOTPLUG
2210	default "0x0"
2211	range 0x1 0x40 if MEMORY_HOTPLUG
2212	range 0x0 0x40
2213	---help---
2214	   Define the padding in terabytes added to the existing physical
2215	   memory size during kernel memory randomization. It is useful
2216	   for memory hotplug support but reduces the entropy available for
2217	   address randomization.
2218
2219	   If unsure, leave at the default value.
2220
2221config HOTPLUG_CPU
2222	bool "Support for hot-pluggable CPUs"
2223	depends on SMP
2224	---help---
2225	  Say Y here to allow turning CPUs off and on. CPUs can be
2226	  controlled through /sys/devices/system/cpu.
2227	  ( Note: power management support will enable this option
2228	    automatically on SMP systems. )
2229	  Say N if you want to disable CPU hotplug.
2230
2231config BOOTPARAM_HOTPLUG_CPU0
2232	bool "Set default setting of cpu0_hotpluggable"
2233	depends on HOTPLUG_CPU
2234	---help---
2235	  Set whether default state of cpu0_hotpluggable is on or off.
2236
2237	  Say Y here to enable CPU0 hotplug by default. If this switch
2238	  is turned on, there is no need to give cpu0_hotplug kernel
2239	  parameter and the CPU0 hotplug feature is enabled by default.
2240
2241	  Please note: there are two known CPU0 dependencies if you want
2242	  to enable the CPU0 hotplug feature either by this switch or by
2243	  cpu0_hotplug kernel parameter.
2244
2245	  First, resume from hibernate or suspend always starts from CPU0.
2246	  So hibernate and suspend are prevented if CPU0 is offline.
2247
2248	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2249	  offline if any interrupt can not migrate out of CPU0. There may
2250	  be other CPU0 dependencies.
2251
2252	  Please make sure the dependencies are under your control before
2253	  you enable this feature.
2254
2255	  Say N if you don't want to enable CPU0 hotplug feature by default.
2256	  You still can enable the CPU0 hotplug feature at boot by kernel
2257	  parameter cpu0_hotplug.
2258
2259config DEBUG_HOTPLUG_CPU0
2260	def_bool n
2261	prompt "Debug CPU0 hotplug"
2262	depends on HOTPLUG_CPU
2263	---help---
2264	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2265	  soon as possible and boots up userspace with CPU0 offlined. User
2266	  can online CPU0 back after boot time.
2267
2268	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2269	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2270	  compilation or giving cpu0_hotplug kernel parameter at boot.
2271
2272	  If unsure, say N.
2273
2274config COMPAT_VDSO
2275	def_bool n
2276	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2277	depends on COMPAT_32
2278	---help---
2279	  Certain buggy versions of glibc will crash if they are
2280	  presented with a 32-bit vDSO that is not mapped at the address
2281	  indicated in its segment table.
2282
2283	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2284	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2285	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2286	  the only released version with the bug, but OpenSUSE 9
2287	  contains a buggy "glibc 2.3.2".
2288
2289	  The symptom of the bug is that everything crashes on startup, saying:
2290	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2291
2292	  Saying Y here changes the default value of the vdso32 boot
2293	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2294	  This works around the glibc bug but hurts performance.
2295
2296	  If unsure, say N: if you are compiling your own kernel, you
2297	  are unlikely to be using a buggy version of glibc.
2298
2299choice
2300	prompt "vsyscall table for legacy applications"
2301	depends on X86_64
2302	default LEGACY_VSYSCALL_EMULATE
2303	help
2304	  Legacy user code that does not know how to find the vDSO expects
2305	  to be able to issue three syscalls by calling fixed addresses in
2306	  kernel space. Since this location is not randomized with ASLR,
2307	  it can be used to assist security vulnerability exploitation.
2308
2309	  This setting can be changed at boot time via the kernel command
2310	  line parameter vsyscall=[emulate|none].
2311
2312	  On a system with recent enough glibc (2.14 or newer) and no
2313	  static binaries, you can say None without a performance penalty
2314	  to improve security.
2315
2316	  If unsure, select "Emulate".
2317
2318	config LEGACY_VSYSCALL_EMULATE
2319		bool "Emulate"
2320		help
2321		  The kernel traps and emulates calls into the fixed
2322		  vsyscall address mapping. This makes the mapping
2323		  non-executable, but it still contains known contents,
2324		  which could be used in certain rare security vulnerability
2325		  exploits. This configuration is recommended when userspace
2326		  still uses the vsyscall area.
2327
2328	config LEGACY_VSYSCALL_NONE
2329		bool "None"
2330		help
2331		  There will be no vsyscall mapping at all. This will
2332		  eliminate any risk of ASLR bypass due to the vsyscall
2333		  fixed address mapping. Attempts to use the vsyscalls
2334		  will be reported to dmesg, so that either old or
2335		  malicious userspace programs can be identified.
2336
2337endchoice
2338
2339config CMDLINE_BOOL
2340	bool "Built-in kernel command line"
2341	---help---
2342	  Allow for specifying boot arguments to the kernel at
2343	  build time.  On some systems (e.g. embedded ones), it is
2344	  necessary or convenient to provide some or all of the
2345	  kernel boot arguments with the kernel itself (that is,
2346	  to not rely on the boot loader to provide them.)
2347
2348	  To compile command line arguments into the kernel,
2349	  set this option to 'Y', then fill in the
2350	  boot arguments in CONFIG_CMDLINE.
2351
2352	  Systems with fully functional boot loaders (i.e. non-embedded)
2353	  should leave this option set to 'N'.
2354
2355config CMDLINE
2356	string "Built-in kernel command string"
2357	depends on CMDLINE_BOOL
2358	default ""
2359	---help---
2360	  Enter arguments here that should be compiled into the kernel
2361	  image and used at boot time.  If the boot loader provides a
2362	  command line at boot time, it is appended to this string to
2363	  form the full kernel command line, when the system boots.
2364
2365	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2366	  change this behavior.
2367
2368	  In most cases, the command line (whether built-in or provided
2369	  by the boot loader) should specify the device for the root
2370	  file system.
2371
2372config CMDLINE_OVERRIDE
2373	bool "Built-in command line overrides boot loader arguments"
2374	depends on CMDLINE_BOOL
2375	---help---
2376	  Set this option to 'Y' to have the kernel ignore the boot loader
2377	  command line, and use ONLY the built-in command line.
2378
2379	  This is used to work around broken boot loaders.  This should
2380	  be set to 'N' under normal conditions.
2381
2382config MODIFY_LDT_SYSCALL
2383	bool "Enable the LDT (local descriptor table)" if EXPERT
2384	default y
2385	---help---
2386	  Linux can allow user programs to install a per-process x86
2387	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2388	  call.  This is required to run 16-bit or segmented code such as
2389	  DOSEMU or some Wine programs.  It is also used by some very old
2390	  threading libraries.
2391
2392	  Enabling this feature adds a small amount of overhead to
2393	  context switches and increases the low-level kernel attack
2394	  surface.  Disabling it removes the modify_ldt(2) system call.
2395
2396	  Saying 'N' here may make sense for embedded or server kernels.
2397
2398source "kernel/livepatch/Kconfig"
2399
2400endmenu
2401
2402config ARCH_HAS_ADD_PAGES
2403	def_bool y
2404	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2405
2406config ARCH_ENABLE_MEMORY_HOTPLUG
2407	def_bool y
2408	depends on X86_64 || (X86_32 && HIGHMEM)
2409
2410config ARCH_ENABLE_MEMORY_HOTREMOVE
2411	def_bool y
2412	depends on MEMORY_HOTPLUG
2413
2414config USE_PERCPU_NUMA_NODE_ID
2415	def_bool y
2416	depends on NUMA
2417
2418config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2419	def_bool y
2420	depends on X86_64 || X86_PAE
2421
2422config ARCH_ENABLE_HUGEPAGE_MIGRATION
2423	def_bool y
2424	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2425
2426config ARCH_ENABLE_THP_MIGRATION
2427	def_bool y
2428	depends on X86_64 && TRANSPARENT_HUGEPAGE
2429
2430menu "Power management and ACPI options"
2431
2432config ARCH_HIBERNATION_HEADER
2433	def_bool y
2434	depends on HIBERNATION
2435
2436source "kernel/power/Kconfig"
2437
2438source "drivers/acpi/Kconfig"
2439
2440source "drivers/sfi/Kconfig"
2441
2442config X86_APM_BOOT
2443	def_bool y
2444	depends on APM
2445
2446menuconfig APM
2447	tristate "APM (Advanced Power Management) BIOS support"
2448	depends on X86_32 && PM_SLEEP
2449	---help---
2450	  APM is a BIOS specification for saving power using several different
2451	  techniques. This is mostly useful for battery powered laptops with
2452	  APM compliant BIOSes. If you say Y here, the system time will be
2453	  reset after a RESUME operation, the /proc/apm device will provide
2454	  battery status information, and user-space programs will receive
2455	  notification of APM "events" (e.g. battery status change).
2456
2457	  If you select "Y" here, you can disable actual use of the APM
2458	  BIOS by passing the "apm=off" option to the kernel at boot time.
2459
2460	  Note that the APM support is almost completely disabled for
2461	  machines with more than one CPU.
2462
2463	  In order to use APM, you will need supporting software. For location
2464	  and more information, read <file:Documentation/power/apm-acpi.txt>
2465	  and the Battery Powered Linux mini-HOWTO, available from
2466	  <http://www.tldp.org/docs.html#howto>.
2467
2468	  This driver does not spin down disk drives (see the hdparm(8)
2469	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2470	  VESA-compliant "green" monitors.
2471
2472	  This driver does not support the TI 4000M TravelMate and the ACER
2473	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2474	  desktop machines also don't have compliant BIOSes, and this driver
2475	  may cause those machines to panic during the boot phase.
2476
2477	  Generally, if you don't have a battery in your machine, there isn't
2478	  much point in using this driver and you should say N. If you get
2479	  random kernel OOPSes or reboots that don't seem to be related to
2480	  anything, try disabling/enabling this option (or disabling/enabling
2481	  APM in your BIOS).
2482
2483	  Some other things you should try when experiencing seemingly random,
2484	  "weird" problems:
2485
2486	  1) make sure that you have enough swap space and that it is
2487	  enabled.
2488	  2) pass the "no-hlt" option to the kernel
2489	  3) switch on floating point emulation in the kernel and pass
2490	  the "no387" option to the kernel
2491	  4) pass the "floppy=nodma" option to the kernel
2492	  5) pass the "mem=4M" option to the kernel (thereby disabling
2493	  all but the first 4 MB of RAM)
2494	  6) make sure that the CPU is not over clocked.
2495	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2496	  8) disable the cache from your BIOS settings
2497	  9) install a fan for the video card or exchange video RAM
2498	  10) install a better fan for the CPU
2499	  11) exchange RAM chips
2500	  12) exchange the motherboard.
2501
2502	  To compile this driver as a module, choose M here: the
2503	  module will be called apm.
2504
2505if APM
2506
2507config APM_IGNORE_USER_SUSPEND
2508	bool "Ignore USER SUSPEND"
2509	---help---
2510	  This option will ignore USER SUSPEND requests. On machines with a
2511	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2512	  series notebooks, it is necessary to say Y because of a BIOS bug.
2513
2514config APM_DO_ENABLE
2515	bool "Enable PM at boot time"
2516	---help---
2517	  Enable APM features at boot time. From page 36 of the APM BIOS
2518	  specification: "When disabled, the APM BIOS does not automatically
2519	  power manage devices, enter the Standby State, enter the Suspend
2520	  State, or take power saving steps in response to CPU Idle calls."
2521	  This driver will make CPU Idle calls when Linux is idle (unless this
2522	  feature is turned off -- see "Do CPU IDLE calls", below). This
2523	  should always save battery power, but more complicated APM features
2524	  will be dependent on your BIOS implementation. You may need to turn
2525	  this option off if your computer hangs at boot time when using APM
2526	  support, or if it beeps continuously instead of suspending. Turn
2527	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2528	  T400CDT. This is off by default since most machines do fine without
2529	  this feature.
2530
2531config APM_CPU_IDLE
2532	depends on CPU_IDLE
2533	bool "Make CPU Idle calls when idle"
2534	---help---
2535	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2536	  On some machines, this can activate improved power savings, such as
2537	  a slowed CPU clock rate, when the machine is idle. These idle calls
2538	  are made after the idle loop has run for some length of time (e.g.,
2539	  333 mS). On some machines, this will cause a hang at boot time or
2540	  whenever the CPU becomes idle. (On machines with more than one CPU,
2541	  this option does nothing.)
2542
2543config APM_DISPLAY_BLANK
2544	bool "Enable console blanking using APM"
2545	---help---
2546	  Enable console blanking using the APM. Some laptops can use this to
2547	  turn off the LCD backlight when the screen blanker of the Linux
2548	  virtual console blanks the screen. Note that this is only used by
2549	  the virtual console screen blanker, and won't turn off the backlight
2550	  when using the X Window system. This also doesn't have anything to
2551	  do with your VESA-compliant power-saving monitor. Further, this
2552	  option doesn't work for all laptops -- it might not turn off your
2553	  backlight at all, or it might print a lot of errors to the console,
2554	  especially if you are using gpm.
2555
2556config APM_ALLOW_INTS
2557	bool "Allow interrupts during APM BIOS calls"
2558	---help---
2559	  Normally we disable external interrupts while we are making calls to
2560	  the APM BIOS as a measure to lessen the effects of a badly behaving
2561	  BIOS implementation.  The BIOS should reenable interrupts if it
2562	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2563	  many of the newer IBM Thinkpads.  If you experience hangs when you
2564	  suspend, try setting this to Y.  Otherwise, say N.
2565
2566endif # APM
2567
2568source "drivers/cpufreq/Kconfig"
2569
2570source "drivers/cpuidle/Kconfig"
2571
2572source "drivers/idle/Kconfig"
2573
2574endmenu
2575
2576
2577menu "Bus options (PCI etc.)"
2578
2579config PCI
2580	bool "PCI support"
2581	default y
2582	---help---
2583	  Find out whether you have a PCI motherboard. PCI is the name of a
2584	  bus system, i.e. the way the CPU talks to the other stuff inside
2585	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2586	  VESA. If you have PCI, say Y, otherwise N.
2587
2588choice
2589	prompt "PCI access mode"
2590	depends on X86_32 && PCI
2591	default PCI_GOANY
2592	---help---
2593	  On PCI systems, the BIOS can be used to detect the PCI devices and
2594	  determine their configuration. However, some old PCI motherboards
2595	  have BIOS bugs and may crash if this is done. Also, some embedded
2596	  PCI-based systems don't have any BIOS at all. Linux can also try to
2597	  detect the PCI hardware directly without using the BIOS.
2598
2599	  With this option, you can specify how Linux should detect the
2600	  PCI devices. If you choose "BIOS", the BIOS will be used,
2601	  if you choose "Direct", the BIOS won't be used, and if you
2602	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2603	  If you choose "Any", the kernel will try MMCONFIG, then the
2604	  direct access method and falls back to the BIOS if that doesn't
2605	  work. If unsure, go with the default, which is "Any".
2606
2607config PCI_GOBIOS
2608	bool "BIOS"
2609
2610config PCI_GOMMCONFIG
2611	bool "MMConfig"
2612
2613config PCI_GODIRECT
2614	bool "Direct"
2615
2616config PCI_GOOLPC
2617	bool "OLPC XO-1"
2618	depends on OLPC
2619
2620config PCI_GOANY
2621	bool "Any"
2622
2623endchoice
2624
2625config PCI_BIOS
2626	def_bool y
2627	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2628
2629# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2630config PCI_DIRECT
2631	def_bool y
2632	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2633
2634config PCI_MMCONFIG
2635	bool "Support mmconfig PCI config space access" if X86_64
2636	default y
2637	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2638	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2639
2640config PCI_OLPC
2641	def_bool y
2642	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2643
2644config PCI_XEN
2645	def_bool y
2646	depends on PCI && XEN
2647	select SWIOTLB_XEN
2648
2649config PCI_DOMAINS
2650	def_bool y
2651	depends on PCI
2652
2653config MMCONF_FAM10H
2654	def_bool y
2655	depends on X86_64 && PCI_MMCONFIG && ACPI
2656
2657config PCI_CNB20LE_QUIRK
2658	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2659	depends on PCI
2660	help
2661	  Read the PCI windows out of the CNB20LE host bridge. This allows
2662	  PCI hotplug to work on systems with the CNB20LE chipset which do
2663	  not have ACPI.
2664
2665	  There's no public spec for this chipset, and this functionality
2666	  is known to be incomplete.
2667
2668	  You should say N unless you know you need this.
2669
2670source "drivers/pci/Kconfig"
2671
2672config ISA_BUS
2673	bool "ISA bus support on modern systems" if EXPERT
2674	help
2675	  Expose ISA bus device drivers and options available for selection and
2676	  configuration. Enable this option if your target machine has an ISA
2677	  bus. ISA is an older system, displaced by PCI and newer bus
2678	  architectures -- if your target machine is modern, it probably does
2679	  not have an ISA bus.
2680
2681	  If unsure, say N.
2682
2683# x86_64 have no ISA slots, but can have ISA-style DMA.
2684config ISA_DMA_API
2685	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2686	default y
2687	help
2688	  Enables ISA-style DMA support for devices requiring such controllers.
2689	  If unsure, say Y.
2690
2691if X86_32
2692
2693config ISA
2694	bool "ISA support"
2695	---help---
2696	  Find out whether you have ISA slots on your motherboard.  ISA is the
2697	  name of a bus system, i.e. the way the CPU talks to the other stuff
2698	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2699	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2700	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2701
2702config EISA
2703	bool "EISA support"
2704	depends on ISA
2705	---help---
2706	  The Extended Industry Standard Architecture (EISA) bus was
2707	  developed as an open alternative to the IBM MicroChannel bus.
2708
2709	  The EISA bus provided some of the features of the IBM MicroChannel
2710	  bus while maintaining backward compatibility with cards made for
2711	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2712	  1995 when it was made obsolete by the PCI bus.
2713
2714	  Say Y here if you are building a kernel for an EISA-based machine.
2715
2716	  Otherwise, say N.
2717
2718source "drivers/eisa/Kconfig"
2719
2720config SCx200
2721	tristate "NatSemi SCx200 support"
2722	---help---
2723	  This provides basic support for National Semiconductor's
2724	  (now AMD's) Geode processors.  The driver probes for the
2725	  PCI-IDs of several on-chip devices, so its a good dependency
2726	  for other scx200_* drivers.
2727
2728	  If compiled as a module, the driver is named scx200.
2729
2730config SCx200HR_TIMER
2731	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2732	depends on SCx200
2733	default y
2734	---help---
2735	  This driver provides a clocksource built upon the on-chip
2736	  27MHz high-resolution timer.  Its also a workaround for
2737	  NSC Geode SC-1100's buggy TSC, which loses time when the
2738	  processor goes idle (as is done by the scheduler).  The
2739	  other workaround is idle=poll boot option.
2740
2741config OLPC
2742	bool "One Laptop Per Child support"
2743	depends on !X86_PAE
2744	select GPIOLIB
2745	select OF
2746	select OF_PROMTREE
2747	select IRQ_DOMAIN
2748	---help---
2749	  Add support for detecting the unique features of the OLPC
2750	  XO hardware.
2751
2752config OLPC_XO1_PM
2753	bool "OLPC XO-1 Power Management"
2754	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2755	---help---
2756	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2757
2758config OLPC_XO1_RTC
2759	bool "OLPC XO-1 Real Time Clock"
2760	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2761	---help---
2762	  Add support for the XO-1 real time clock, which can be used as a
2763	  programmable wakeup source.
2764
2765config OLPC_XO1_SCI
2766	bool "OLPC XO-1 SCI extras"
2767	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2768	depends on INPUT=y
2769	select POWER_SUPPLY
2770	---help---
2771	  Add support for SCI-based features of the OLPC XO-1 laptop:
2772	   - EC-driven system wakeups
2773	   - Power button
2774	   - Ebook switch
2775	   - Lid switch
2776	   - AC adapter status updates
2777	   - Battery status updates
2778
2779config OLPC_XO15_SCI
2780	bool "OLPC XO-1.5 SCI extras"
2781	depends on OLPC && ACPI
2782	select POWER_SUPPLY
2783	---help---
2784	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2785	   - EC-driven system wakeups
2786	   - AC adapter status updates
2787	   - Battery status updates
2788
2789config ALIX
2790	bool "PCEngines ALIX System Support (LED setup)"
2791	select GPIOLIB
2792	---help---
2793	  This option enables system support for the PCEngines ALIX.
2794	  At present this just sets up LEDs for GPIO control on
2795	  ALIX2/3/6 boards.  However, other system specific setup should
2796	  get added here.
2797
2798	  Note: You must still enable the drivers for GPIO and LED support
2799	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2800
2801	  Note: You have to set alix.force=1 for boards with Award BIOS.
2802
2803config NET5501
2804	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2805	select GPIOLIB
2806	---help---
2807	  This option enables system support for the Soekris Engineering net5501.
2808
2809config GEOS
2810	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2811	select GPIOLIB
2812	depends on DMI
2813	---help---
2814	  This option enables system support for the Traverse Technologies GEOS.
2815
2816config TS5500
2817	bool "Technologic Systems TS-5500 platform support"
2818	depends on MELAN
2819	select CHECK_SIGNATURE
2820	select NEW_LEDS
2821	select LEDS_CLASS
2822	---help---
2823	  This option enables system support for the Technologic Systems TS-5500.
2824
2825endif # X86_32
2826
2827config AMD_NB
2828	def_bool y
2829	depends on CPU_SUP_AMD && PCI
2830
2831source "drivers/pcmcia/Kconfig"
2832
2833config RAPIDIO
2834	tristate "RapidIO support"
2835	depends on PCI
2836	help
2837	  If enabled this option will include drivers and the core
2838	  infrastructure code to support RapidIO interconnect devices.
2839
2840source "drivers/rapidio/Kconfig"
2841
2842config X86_SYSFB
2843	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2844	help
2845	  Firmwares often provide initial graphics framebuffers so the BIOS,
2846	  bootloader or kernel can show basic video-output during boot for
2847	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2848	  Extensions and EFI-framebuffers for this, which are mostly limited
2849	  to x86.
2850	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2851	  framebuffers so the new generic system-framebuffer drivers can be
2852	  used on x86. If the framebuffer is not compatible with the generic
2853	  modes, it is advertised as fallback platform framebuffer so legacy
2854	  drivers like efifb, vesafb and uvesafb can pick it up.
2855	  If this option is not selected, all system framebuffers are always
2856	  marked as fallback platform framebuffers as usual.
2857
2858	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2859	  not be able to pick up generic system framebuffers if this option
2860	  is selected. You are highly encouraged to enable simplefb as
2861	  replacement if you select this option. simplefb can correctly deal
2862	  with generic system framebuffers. But you should still keep vesafb
2863	  and others enabled as fallback if a system framebuffer is
2864	  incompatible with simplefb.
2865
2866	  If unsure, say Y.
2867
2868endmenu
2869
2870
2871menu "Binary Emulations"
2872
2873config IA32_EMULATION
2874	bool "IA32 Emulation"
2875	depends on X86_64
2876	select ARCH_WANT_OLD_COMPAT_IPC
2877	select BINFMT_ELF
2878	select COMPAT_BINFMT_ELF
2879	select COMPAT_OLD_SIGACTION
2880	---help---
2881	  Include code to run legacy 32-bit programs under a
2882	  64-bit kernel. You should likely turn this on, unless you're
2883	  100% sure that you don't have any 32-bit programs left.
2884
2885config IA32_AOUT
2886	tristate "IA32 a.out support"
2887	depends on IA32_EMULATION
2888	---help---
2889	  Support old a.out binaries in the 32bit emulation.
2890
2891config X86_X32
2892	bool "x32 ABI for 64-bit mode"
2893	depends on X86_64
2894	---help---
2895	  Include code to run binaries for the x32 native 32-bit ABI
2896	  for 64-bit processors.  An x32 process gets access to the
2897	  full 64-bit register file and wide data path while leaving
2898	  pointers at 32 bits for smaller memory footprint.
2899
2900	  You will need a recent binutils (2.22 or later) with
2901	  elf32_x86_64 support enabled to compile a kernel with this
2902	  option set.
2903
2904config COMPAT_32
2905	def_bool y
2906	depends on IA32_EMULATION || X86_32
2907	select HAVE_UID16
2908	select OLD_SIGSUSPEND3
2909
2910config COMPAT
2911	def_bool y
2912	depends on IA32_EMULATION || X86_X32
2913
2914if COMPAT
2915config COMPAT_FOR_U64_ALIGNMENT
2916	def_bool y
2917
2918config SYSVIPC_COMPAT
2919	def_bool y
2920	depends on SYSVIPC
2921endif
2922
2923endmenu
2924
2925
2926config HAVE_ATOMIC_IOMAP
2927	def_bool y
2928	depends on X86_32
2929
2930config X86_DEV_DMA_OPS
2931	bool
2932	depends on X86_64 || STA2X11
2933
2934config X86_DMA_REMAP
2935	bool
2936	depends on STA2X11
2937
2938config HAVE_GENERIC_GUP
2939	def_bool y
2940
2941source "drivers/firmware/Kconfig"
2942
2943source "arch/x86/kvm/Kconfig"
2944