xref: /openbmc/linux/arch/x86/Kconfig (revision 58f9d806)
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 INTEL_RDT
448	bool "Intel Resource Director Technology support"
449	depends on X86 && CPU_SUP_INTEL
450	select KERNFS
451	help
452	  Select to enable resource allocation and monitoring which are
453	  sub-features of Intel Resource Director Technology(RDT). More
454	  information about RDT can be found in the Intel x86
455	  Architecture Software Developer Manual.
456
457	  Say N if unsure.
458
459if X86_32
460config X86_BIGSMP
461	bool "Support for big SMP systems with more than 8 CPUs"
462	depends on SMP
463	---help---
464	  This option is needed for the systems that have more than 8 CPUs
465
466config X86_EXTENDED_PLATFORM
467	bool "Support for extended (non-PC) x86 platforms"
468	default y
469	---help---
470	  If you disable this option then the kernel will only support
471	  standard PC platforms. (which covers the vast majority of
472	  systems out there.)
473
474	  If you enable this option then you'll be able to select support
475	  for the following (non-PC) 32 bit x86 platforms:
476		Goldfish (Android emulator)
477		AMD Elan
478		RDC R-321x SoC
479		SGI 320/540 (Visual Workstation)
480		STA2X11-based (e.g. Northville)
481		Moorestown MID devices
482
483	  If you have one of these systems, or if you want to build a
484	  generic distribution kernel, say Y here - otherwise say N.
485endif
486
487if X86_64
488config X86_EXTENDED_PLATFORM
489	bool "Support for extended (non-PC) x86 platforms"
490	default y
491	---help---
492	  If you disable this option then the kernel will only support
493	  standard PC platforms. (which covers the vast majority of
494	  systems out there.)
495
496	  If you enable this option then you'll be able to select support
497	  for the following (non-PC) 64 bit x86 platforms:
498		Numascale NumaChip
499		ScaleMP vSMP
500		SGI Ultraviolet
501
502	  If you have one of these systems, or if you want to build a
503	  generic distribution kernel, say Y here - otherwise say N.
504endif
505# This is an alphabetically sorted list of 64 bit extended platforms
506# Please maintain the alphabetic order if and when there are additions
507config X86_NUMACHIP
508	bool "Numascale NumaChip"
509	depends on X86_64
510	depends on X86_EXTENDED_PLATFORM
511	depends on NUMA
512	depends on SMP
513	depends on X86_X2APIC
514	depends on PCI_MMCONFIG
515	---help---
516	  Adds support for Numascale NumaChip large-SMP systems. Needed to
517	  enable more than ~168 cores.
518	  If you don't have one of these, you should say N here.
519
520config X86_VSMP
521	bool "ScaleMP vSMP"
522	select HYPERVISOR_GUEST
523	select PARAVIRT
524	depends on X86_64 && PCI
525	depends on X86_EXTENDED_PLATFORM
526	depends on SMP
527	---help---
528	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
529	  supposed to run on these EM64T-based machines.  Only choose this option
530	  if you have one of these machines.
531
532config X86_UV
533	bool "SGI Ultraviolet"
534	depends on X86_64
535	depends on X86_EXTENDED_PLATFORM
536	depends on NUMA
537	depends on EFI
538	depends on X86_X2APIC
539	depends on PCI
540	---help---
541	  This option is needed in order to support SGI Ultraviolet systems.
542	  If you don't have one of these, you should say N here.
543
544# Following is an alphabetically sorted list of 32 bit extended platforms
545# Please maintain the alphabetic order if and when there are additions
546
547config X86_GOLDFISH
548       bool "Goldfish (Virtual Platform)"
549       depends on X86_EXTENDED_PLATFORM
550       ---help---
551	 Enable support for the Goldfish virtual platform used primarily
552	 for Android development. Unless you are building for the Android
553	 Goldfish emulator say N here.
554
555config X86_INTEL_CE
556	bool "CE4100 TV platform"
557	depends on PCI
558	depends on PCI_GODIRECT
559	depends on X86_IO_APIC
560	depends on X86_32
561	depends on X86_EXTENDED_PLATFORM
562	select X86_REBOOTFIXUPS
563	select OF
564	select OF_EARLY_FLATTREE
565	---help---
566	  Select for the Intel CE media processor (CE4100) SOC.
567	  This option compiles in support for the CE4100 SOC for settop
568	  boxes and media devices.
569
570config X86_INTEL_MID
571	bool "Intel MID platform support"
572	depends on X86_EXTENDED_PLATFORM
573	depends on X86_PLATFORM_DEVICES
574	depends on PCI
575	depends on X86_64 || (PCI_GOANY && X86_32)
576	depends on X86_IO_APIC
577	select SFI
578	select I2C
579	select DW_APB_TIMER
580	select APB_TIMER
581	select INTEL_SCU_IPC
582	select MFD_INTEL_MSIC
583	---help---
584	  Select to build a kernel capable of supporting Intel MID (Mobile
585	  Internet Device) platform systems which do not have the PCI legacy
586	  interfaces. If you are building for a PC class system say N here.
587
588	  Intel MID platforms are based on an Intel processor and chipset which
589	  consume less power than most of the x86 derivatives.
590
591config X86_INTEL_QUARK
592	bool "Intel Quark platform support"
593	depends on X86_32
594	depends on X86_EXTENDED_PLATFORM
595	depends on X86_PLATFORM_DEVICES
596	depends on X86_TSC
597	depends on PCI
598	depends on PCI_GOANY
599	depends on X86_IO_APIC
600	select IOSF_MBI
601	select INTEL_IMR
602	select COMMON_CLK
603	---help---
604	  Select to include support for Quark X1000 SoC.
605	  Say Y here if you have a Quark based system such as the Arduino
606	  compatible Intel Galileo.
607
608config X86_INTEL_LPSS
609	bool "Intel Low Power Subsystem Support"
610	depends on X86 && ACPI
611	select COMMON_CLK
612	select PINCTRL
613	select IOSF_MBI
614	---help---
615	  Select to build support for Intel Low Power Subsystem such as
616	  found on Intel Lynxpoint PCH. Selecting this option enables
617	  things like clock tree (common clock framework) and pincontrol
618	  which are needed by the LPSS peripheral drivers.
619
620config X86_AMD_PLATFORM_DEVICE
621	bool "AMD ACPI2Platform devices support"
622	depends on ACPI
623	select COMMON_CLK
624	select PINCTRL
625	---help---
626	  Select to interpret AMD specific ACPI device to platform device
627	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
628	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
629	  implemented under PINCTRL subsystem.
630
631config IOSF_MBI
632	tristate "Intel SoC IOSF Sideband support for SoC platforms"
633	depends on PCI
634	---help---
635	  This option enables sideband register access support for Intel SoC
636	  platforms. On these platforms the IOSF sideband is used in lieu of
637	  MSR's for some register accesses, mostly but not limited to thermal
638	  and power. Drivers may query the availability of this device to
639	  determine if they need the sideband in order to work on these
640	  platforms. The sideband is available on the following SoC products.
641	  This list is not meant to be exclusive.
642	   - BayTrail
643	   - Braswell
644	   - Quark
645
646	  You should say Y if you are running a kernel on one of these SoC's.
647
648config IOSF_MBI_DEBUG
649	bool "Enable IOSF sideband access through debugfs"
650	depends on IOSF_MBI && DEBUG_FS
651	---help---
652	  Select this option to expose the IOSF sideband access registers (MCR,
653	  MDR, MCRX) through debugfs to write and read register information from
654	  different units on the SoC. This is most useful for obtaining device
655	  state information for debug and analysis. As this is a general access
656	  mechanism, users of this option would have specific knowledge of the
657	  device they want to access.
658
659	  If you don't require the option or are in doubt, say N.
660
661config X86_RDC321X
662	bool "RDC R-321x SoC"
663	depends on X86_32
664	depends on X86_EXTENDED_PLATFORM
665	select M486
666	select X86_REBOOTFIXUPS
667	---help---
668	  This option is needed for RDC R-321x system-on-chip, also known
669	  as R-8610-(G).
670	  If you don't have one of these chips, you should say N here.
671
672config X86_32_NON_STANDARD
673	bool "Support non-standard 32-bit SMP architectures"
674	depends on X86_32 && SMP
675	depends on X86_EXTENDED_PLATFORM
676	---help---
677	  This option compiles in the bigsmp and STA2X11 default
678	  subarchitectures.  It is intended for a generic binary
679	  kernel. If you select them all, kernel will probe it one by
680	  one and will fallback to default.
681
682# Alphabetically sorted list of Non standard 32 bit platforms
683
684config X86_SUPPORTS_MEMORY_FAILURE
685	def_bool y
686	# MCE code calls memory_failure():
687	depends on X86_MCE
688	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
689	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
690	depends on X86_64 || !SPARSEMEM
691	select ARCH_SUPPORTS_MEMORY_FAILURE
692
693config STA2X11
694	bool "STA2X11 Companion Chip Support"
695	depends on X86_32_NON_STANDARD && PCI
696	select ARCH_HAS_PHYS_TO_DMA
697	select X86_DEV_DMA_OPS
698	select X86_DMA_REMAP
699	select SWIOTLB
700	select MFD_STA2X11
701	select GPIOLIB
702	---help---
703	  This adds support for boards based on the STA2X11 IO-Hub,
704	  a.k.a. "ConneXt". The chip is used in place of the standard
705	  PC chipset, so all "standard" peripherals are missing. If this
706	  option is selected the kernel will still be able to boot on
707	  standard PC machines.
708
709config X86_32_IRIS
710	tristate "Eurobraille/Iris poweroff module"
711	depends on X86_32
712	---help---
713	  The Iris machines from EuroBraille do not have APM or ACPI support
714	  to shut themselves down properly.  A special I/O sequence is
715	  needed to do so, which is what this module does at
716	  kernel shutdown.
717
718	  This is only for Iris machines from EuroBraille.
719
720	  If unused, say N.
721
722config SCHED_OMIT_FRAME_POINTER
723	def_bool y
724	prompt "Single-depth WCHAN output"
725	depends on X86
726	---help---
727	  Calculate simpler /proc/<PID>/wchan values. If this option
728	  is disabled then wchan values will recurse back to the
729	  caller function. This provides more accurate wchan values,
730	  at the expense of slightly more scheduling overhead.
731
732	  If in doubt, say "Y".
733
734menuconfig HYPERVISOR_GUEST
735	bool "Linux guest support"
736	---help---
737	  Say Y here to enable options for running Linux under various hyper-
738	  visors. This option enables basic hypervisor detection and platform
739	  setup.
740
741	  If you say N, all options in this submenu will be skipped and
742	  disabled, and Linux guest support won't be built in.
743
744if HYPERVISOR_GUEST
745
746config PARAVIRT
747	bool "Enable paravirtualization code"
748	---help---
749	  This changes the kernel so it can modify itself when it is run
750	  under a hypervisor, potentially improving performance significantly
751	  over full virtualization.  However, when run without a hypervisor
752	  the kernel is theoretically slower and slightly larger.
753
754config PARAVIRT_XXL
755	bool
756
757config PARAVIRT_DEBUG
758	bool "paravirt-ops debugging"
759	depends on PARAVIRT && DEBUG_KERNEL
760	---help---
761	  Enable to debug paravirt_ops internals.  Specifically, BUG if
762	  a paravirt_op is missing when it is called.
763
764config PARAVIRT_SPINLOCKS
765	bool "Paravirtualization layer for spinlocks"
766	depends on PARAVIRT && SMP
767	---help---
768	  Paravirtualized spinlocks allow a pvops backend to replace the
769	  spinlock implementation with something virtualization-friendly
770	  (for example, block the virtual CPU rather than spinning).
771
772	  It has a minimal impact on native kernels and gives a nice performance
773	  benefit on paravirtualized KVM / Xen kernels.
774
775	  If you are unsure how to answer this question, answer Y.
776
777config QUEUED_LOCK_STAT
778	bool "Paravirt queued spinlock statistics"
779	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
780	---help---
781	  Enable the collection of statistical data on the slowpath
782	  behavior of paravirtualized queued spinlocks and report
783	  them on debugfs.
784
785source "arch/x86/xen/Kconfig"
786
787config KVM_GUEST
788	bool "KVM Guest support (including kvmclock)"
789	depends on PARAVIRT
790	select PARAVIRT_CLOCK
791	default y
792	---help---
793	  This option enables various optimizations for running under the KVM
794	  hypervisor. It includes a paravirtualized clock, so that instead
795	  of relying on a PIT (or probably other) emulation by the
796	  underlying device model, the host provides the guest with
797	  timing infrastructure such as time of day, and system time
798
799config PVH
800	bool "Support for running PVH guests"
801	---help---
802	  This option enables the PVH entry point for guest virtual machines
803	  as specified in the x86/HVM direct boot ABI.
804
805config KVM_DEBUG_FS
806	bool "Enable debug information for KVM Guests in debugfs"
807	depends on KVM_GUEST && DEBUG_FS
808	---help---
809	  This option enables collection of various statistics for KVM guest.
810	  Statistics are displayed in debugfs filesystem. Enabling this option
811	  may incur significant overhead.
812
813config PARAVIRT_TIME_ACCOUNTING
814	bool "Paravirtual steal time accounting"
815	depends on PARAVIRT
816	---help---
817	  Select this option to enable fine granularity task steal time
818	  accounting. Time spent executing other tasks in parallel with
819	  the current vCPU is discounted from the vCPU power. To account for
820	  that, there can be a small performance impact.
821
822	  If in doubt, say N here.
823
824config PARAVIRT_CLOCK
825	bool
826
827config JAILHOUSE_GUEST
828	bool "Jailhouse non-root cell support"
829	depends on X86_64 && PCI
830	select X86_PM_TIMER
831	---help---
832	  This option allows to run Linux as guest in a Jailhouse non-root
833	  cell. You can leave this option disabled if you only want to start
834	  Jailhouse and run Linux afterwards in the root cell.
835
836endif #HYPERVISOR_GUEST
837
838source "arch/x86/Kconfig.cpu"
839
840config HPET_TIMER
841	def_bool X86_64
842	prompt "HPET Timer Support" if X86_32
843	---help---
844	  Use the IA-PC HPET (High Precision Event Timer) to manage
845	  time in preference to the PIT and RTC, if a HPET is
846	  present.
847	  HPET is the next generation timer replacing legacy 8254s.
848	  The HPET provides a stable time base on SMP
849	  systems, unlike the TSC, but it is more expensive to access,
850	  as it is off-chip.  The interface used is documented
851	  in the HPET spec, revision 1.
852
853	  You can safely choose Y here.  However, HPET will only be
854	  activated if the platform and the BIOS support this feature.
855	  Otherwise the 8254 will be used for timing services.
856
857	  Choose N to continue using the legacy 8254 timer.
858
859config HPET_EMULATE_RTC
860	def_bool y
861	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
862
863config APB_TIMER
864       def_bool y if X86_INTEL_MID
865       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
866       select DW_APB_TIMER
867       depends on X86_INTEL_MID && SFI
868       help
869         APB timer is the replacement for 8254, HPET on X86 MID platforms.
870         The APBT provides a stable time base on SMP
871         systems, unlike the TSC, but it is more expensive to access,
872         as it is off-chip. APB timers are always running regardless of CPU
873         C states, they are used as per CPU clockevent device when possible.
874
875# Mark as expert because too many people got it wrong.
876# The code disables itself when not needed.
877config DMI
878	default y
879	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
880	bool "Enable DMI scanning" if EXPERT
881	---help---
882	  Enabled scanning of DMI to identify machine quirks. Say Y
883	  here unless you have verified that your setup is not
884	  affected by entries in the DMI blacklist. Required by PNP
885	  BIOS code.
886
887config GART_IOMMU
888	bool "Old AMD GART IOMMU support"
889	select IOMMU_HELPER
890	select SWIOTLB
891	depends on X86_64 && PCI && AMD_NB
892	---help---
893	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
894	  GART based hardware IOMMUs.
895
896	  The GART supports full DMA access for devices with 32-bit access
897	  limitations, on systems with more than 3 GB. This is usually needed
898	  for USB, sound, many IDE/SATA chipsets and some other devices.
899
900	  Newer systems typically have a modern AMD IOMMU, supported via
901	  the CONFIG_AMD_IOMMU=y config option.
902
903	  In normal configurations this driver is only active when needed:
904	  there's more than 3 GB of memory and the system contains a
905	  32-bit limited device.
906
907	  If unsure, say Y.
908
909config CALGARY_IOMMU
910	bool "IBM Calgary IOMMU support"
911	select IOMMU_HELPER
912	select SWIOTLB
913	depends on X86_64 && PCI
914	---help---
915	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
916	  systems. Needed to run systems with more than 3GB of memory
917	  properly with 32-bit PCI devices that do not support DAC
918	  (Double Address Cycle). Calgary also supports bus level
919	  isolation, where all DMAs pass through the IOMMU.  This
920	  prevents them from going anywhere except their intended
921	  destination. This catches hard-to-find kernel bugs and
922	  mis-behaving drivers and devices that do not use the DMA-API
923	  properly to set up their DMA buffers.  The IOMMU can be
924	  turned off at boot time with the iommu=off parameter.
925	  Normally the kernel will make the right choice by itself.
926	  If unsure, say Y.
927
928config CALGARY_IOMMU_ENABLED_BY_DEFAULT
929	def_bool y
930	prompt "Should Calgary be enabled by default?"
931	depends on CALGARY_IOMMU
932	---help---
933	  Should Calgary be enabled by default? if you choose 'y', Calgary
934	  will be used (if it exists). If you choose 'n', Calgary will not be
935	  used even if it exists. If you choose 'n' and would like to use
936	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
937	  If unsure, say Y.
938
939config MAXSMP
940	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
941	depends on X86_64 && SMP && DEBUG_KERNEL
942	select CPUMASK_OFFSTACK
943	---help---
944	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
945	  If unsure, say N.
946
947#
948# The maximum number of CPUs supported:
949#
950# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951# and which can be configured interactively in the
952# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953#
954# The ranges are different on 32-bit and 64-bit kernels, depending on
955# hardware capabilities and scalability features of the kernel.
956#
957# ( If MAXSMP is enabled we just use the highest possible value and disable
958#   interactive configuration. )
959#
960
961config NR_CPUS_RANGE_BEGIN
962	int
963	default NR_CPUS_RANGE_END if MAXSMP
964	default    1 if !SMP
965	default    2
966
967config NR_CPUS_RANGE_END
968	int
969	depends on X86_32
970	default   64 if  SMP &&  X86_BIGSMP
971	default    8 if  SMP && !X86_BIGSMP
972	default    1 if !SMP
973
974config NR_CPUS_RANGE_END
975	int
976	depends on X86_64
977	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
978	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
979	default    1 if !SMP
980
981config NR_CPUS_DEFAULT
982	int
983	depends on X86_32
984	default   32 if  X86_BIGSMP
985	default    8 if  SMP
986	default    1 if !SMP
987
988config NR_CPUS_DEFAULT
989	int
990	depends on X86_64
991	default 8192 if  MAXSMP
992	default   64 if  SMP
993	default    1 if !SMP
994
995config NR_CPUS
996	int "Maximum number of CPUs" if SMP && !MAXSMP
997	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998	default NR_CPUS_DEFAULT
999	---help---
1000	  This allows you to specify the maximum number of CPUs which this
1001	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1002	  supported value is 8192, otherwise the maximum value is 512.  The
1003	  minimum value which makes sense is 2.
1004
1005	  This is purely to save memory: each supported CPU adds about 8KB
1006	  to the kernel image.
1007
1008config SCHED_SMT
1009	def_bool y if SMP
1010
1011config SCHED_MC
1012	def_bool y
1013	prompt "Multi-core scheduler support"
1014	depends on SMP
1015	---help---
1016	  Multi-core scheduler support improves the CPU scheduler's decision
1017	  making when dealing with multi-core CPU chips at a cost of slightly
1018	  increased overhead in some places. If unsure say N here.
1019
1020config SCHED_MC_PRIO
1021	bool "CPU core priorities scheduler support"
1022	depends on SCHED_MC && CPU_SUP_INTEL
1023	select X86_INTEL_PSTATE
1024	select CPU_FREQ
1025	default y
1026	---help---
1027	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1028	  core ordering determined at manufacturing time, which allows
1029	  certain cores to reach higher turbo frequencies (when running
1030	  single threaded workloads) than others.
1031
1032	  Enabling this kernel feature teaches the scheduler about
1033	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1034	  scheduler's CPU selection logic accordingly, so that higher
1035	  overall system performance can be achieved.
1036
1037	  This feature will have no effect on CPUs without this feature.
1038
1039	  If unsure say Y here.
1040
1041config UP_LATE_INIT
1042       def_bool y
1043       depends on !SMP && X86_LOCAL_APIC
1044
1045config X86_UP_APIC
1046	bool "Local APIC support on uniprocessors" if !PCI_MSI
1047	default PCI_MSI
1048	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1049	---help---
1050	  A local APIC (Advanced Programmable Interrupt Controller) is an
1051	  integrated interrupt controller in the CPU. If you have a single-CPU
1052	  system which has a processor with a local APIC, you can say Y here to
1053	  enable and use it. If you say Y here even though your machine doesn't
1054	  have a local APIC, then the kernel will still run with no slowdown at
1055	  all. The local APIC supports CPU-generated self-interrupts (timer,
1056	  performance counters), and the NMI watchdog which detects hard
1057	  lockups.
1058
1059config X86_UP_IOAPIC
1060	bool "IO-APIC support on uniprocessors"
1061	depends on X86_UP_APIC
1062	---help---
1063	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1064	  SMP-capable replacement for PC-style interrupt controllers. Most
1065	  SMP systems and many recent uniprocessor systems have one.
1066
1067	  If you have a single-CPU system with an IO-APIC, you can say Y here
1068	  to use it. If you say Y here even though your machine doesn't have
1069	  an IO-APIC, then the kernel will still run with no slowdown at all.
1070
1071config X86_LOCAL_APIC
1072	def_bool y
1073	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1074	select IRQ_DOMAIN_HIERARCHY
1075	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1076
1077config X86_IO_APIC
1078	def_bool y
1079	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1080
1081config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1082	bool "Reroute for broken boot IRQs"
1083	depends on X86_IO_APIC
1084	---help---
1085	  This option enables a workaround that fixes a source of
1086	  spurious interrupts. This is recommended when threaded
1087	  interrupt handling is used on systems where the generation of
1088	  superfluous "boot interrupts" cannot be disabled.
1089
1090	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1091	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1092	  kernel does during interrupt handling). On chipsets where this
1093	  boot IRQ generation cannot be disabled, this workaround keeps
1094	  the original IRQ line masked so that only the equivalent "boot
1095	  IRQ" is delivered to the CPUs. The workaround also tells the
1096	  kernel to set up the IRQ handler on the boot IRQ line. In this
1097	  way only one interrupt is delivered to the kernel. Otherwise
1098	  the spurious second interrupt may cause the kernel to bring
1099	  down (vital) interrupt lines.
1100
1101	  Only affects "broken" chipsets. Interrupt sharing may be
1102	  increased on these systems.
1103
1104config X86_MCE
1105	bool "Machine Check / overheating reporting"
1106	select GENERIC_ALLOCATOR
1107	default y
1108	---help---
1109	  Machine Check support allows the processor to notify the
1110	  kernel if it detects a problem (e.g. overheating, data corruption).
1111	  The action the kernel takes depends on the severity of the problem,
1112	  ranging from warning messages to halting the machine.
1113
1114config X86_MCELOG_LEGACY
1115	bool "Support for deprecated /dev/mcelog character device"
1116	depends on X86_MCE
1117	---help---
1118	  Enable support for /dev/mcelog which is needed by the old mcelog
1119	  userspace logging daemon. Consider switching to the new generation
1120	  rasdaemon solution.
1121
1122config X86_MCE_INTEL
1123	def_bool y
1124	prompt "Intel MCE features"
1125	depends on X86_MCE && X86_LOCAL_APIC
1126	---help---
1127	   Additional support for intel specific MCE features such as
1128	   the thermal monitor.
1129
1130config X86_MCE_AMD
1131	def_bool y
1132	prompt "AMD MCE features"
1133	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1134	---help---
1135	   Additional support for AMD specific MCE features such as
1136	   the DRAM Error Threshold.
1137
1138config X86_ANCIENT_MCE
1139	bool "Support for old Pentium 5 / WinChip machine checks"
1140	depends on X86_32 && X86_MCE
1141	---help---
1142	  Include support for machine check handling on old Pentium 5 or WinChip
1143	  systems. These typically need to be enabled explicitly on the command
1144	  line.
1145
1146config X86_MCE_THRESHOLD
1147	depends on X86_MCE_AMD || X86_MCE_INTEL
1148	def_bool y
1149
1150config X86_MCE_INJECT
1151	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1152	tristate "Machine check injector support"
1153	---help---
1154	  Provide support for injecting machine checks for testing purposes.
1155	  If you don't know what a machine check is and you don't do kernel
1156	  QA it is safe to say n.
1157
1158config X86_THERMAL_VECTOR
1159	def_bool y
1160	depends on X86_MCE_INTEL
1161
1162source "arch/x86/events/Kconfig"
1163
1164config X86_LEGACY_VM86
1165	bool "Legacy VM86 support"
1166	depends on X86_32
1167	---help---
1168	  This option allows user programs to put the CPU into V8086
1169	  mode, which is an 80286-era approximation of 16-bit real mode.
1170
1171	  Some very old versions of X and/or vbetool require this option
1172	  for user mode setting.  Similarly, DOSEMU will use it if
1173	  available to accelerate real mode DOS programs.  However, any
1174	  recent version of DOSEMU, X, or vbetool should be fully
1175	  functional even without kernel VM86 support, as they will all
1176	  fall back to software emulation. Nevertheless, if you are using
1177	  a 16-bit DOS program where 16-bit performance matters, vm86
1178	  mode might be faster than emulation and you might want to
1179	  enable this option.
1180
1181	  Note that any app that works on a 64-bit kernel is unlikely to
1182	  need this option, as 64-bit kernels don't, and can't, support
1183	  V8086 mode. This option is also unrelated to 16-bit protected
1184	  mode and is not needed to run most 16-bit programs under Wine.
1185
1186	  Enabling this option increases the complexity of the kernel
1187	  and slows down exception handling a tiny bit.
1188
1189	  If unsure, say N here.
1190
1191config VM86
1192       bool
1193       default X86_LEGACY_VM86
1194
1195config X86_16BIT
1196	bool "Enable support for 16-bit segments" if EXPERT
1197	default y
1198	depends on MODIFY_LDT_SYSCALL
1199	---help---
1200	  This option is required by programs like Wine to run 16-bit
1201	  protected mode legacy code on x86 processors.  Disabling
1202	  this option saves about 300 bytes on i386, or around 6K text
1203	  plus 16K runtime memory on x86-64,
1204
1205config X86_ESPFIX32
1206	def_bool y
1207	depends on X86_16BIT && X86_32
1208
1209config X86_ESPFIX64
1210	def_bool y
1211	depends on X86_16BIT && X86_64
1212
1213config X86_VSYSCALL_EMULATION
1214       bool "Enable vsyscall emulation" if EXPERT
1215       default y
1216       depends on X86_64
1217       ---help---
1218	 This enables emulation of the legacy vsyscall page.  Disabling
1219	 it is roughly equivalent to booting with vsyscall=none, except
1220	 that it will also disable the helpful warning if a program
1221	 tries to use a vsyscall.  With this option set to N, offending
1222	 programs will just segfault, citing addresses of the form
1223	 0xffffffffff600?00.
1224
1225	 This option is required by many programs built before 2013, and
1226	 care should be used even with newer programs if set to N.
1227
1228	 Disabling this option saves about 7K of kernel size and
1229	 possibly 4K of additional runtime pagetable memory.
1230
1231config TOSHIBA
1232	tristate "Toshiba Laptop support"
1233	depends on X86_32
1234	---help---
1235	  This adds a driver to safely access the System Management Mode of
1236	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1237	  not work on models with a Phoenix BIOS. The System Management Mode
1238	  is used to set the BIOS and power saving options on Toshiba portables.
1239
1240	  For information on utilities to make use of this driver see the
1241	  Toshiba Linux utilities web site at:
1242	  <http://www.buzzard.org.uk/toshiba/>.
1243
1244	  Say Y if you intend to run this kernel on a Toshiba portable.
1245	  Say N otherwise.
1246
1247config I8K
1248	tristate "Dell i8k legacy laptop support"
1249	select HWMON
1250	select SENSORS_DELL_SMM
1251	---help---
1252	  This option enables legacy /proc/i8k userspace interface in hwmon
1253	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1254	  temperature and allows controlling fan speeds of Dell laptops via
1255	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1256	  it reports also power and hotkey status. For fan speed control is
1257	  needed userspace package i8kutils.
1258
1259	  Say Y if you intend to run this kernel on old Dell laptops or want to
1260	  use userspace package i8kutils.
1261	  Say N otherwise.
1262
1263config X86_REBOOTFIXUPS
1264	bool "Enable X86 board specific fixups for reboot"
1265	depends on X86_32
1266	---help---
1267	  This enables chipset and/or board specific fixups to be done
1268	  in order to get reboot to work correctly. This is only needed on
1269	  some combinations of hardware and BIOS. The symptom, for which
1270	  this config is intended, is when reboot ends with a stalled/hung
1271	  system.
1272
1273	  Currently, the only fixup is for the Geode machines using
1274	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1275
1276	  Say Y if you want to enable the fixup. Currently, it's safe to
1277	  enable this option even if you don't need it.
1278	  Say N otherwise.
1279
1280config MICROCODE
1281	bool "CPU microcode loading support"
1282	default y
1283	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1284	select FW_LOADER
1285	---help---
1286	  If you say Y here, you will be able to update the microcode on
1287	  Intel and AMD processors. The Intel support is for the IA32 family,
1288	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1289	  AMD support is for families 0x10 and later. You will obviously need
1290	  the actual microcode binary data itself which is not shipped with
1291	  the Linux kernel.
1292
1293	  The preferred method to load microcode from a detached initrd is described
1294	  in Documentation/x86/microcode.txt. For that you need to enable
1295	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1296	  initrd for microcode blobs.
1297
1298	  In addition, you can build the microcode into the kernel. For that you
1299	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1300	  config option.
1301
1302config MICROCODE_INTEL
1303	bool "Intel microcode loading support"
1304	depends on MICROCODE
1305	default MICROCODE
1306	select FW_LOADER
1307	---help---
1308	  This options enables microcode patch loading support for Intel
1309	  processors.
1310
1311	  For the current Intel microcode data package go to
1312	  <https://downloadcenter.intel.com> and search for
1313	  'Linux Processor Microcode Data File'.
1314
1315config MICROCODE_AMD
1316	bool "AMD microcode loading support"
1317	depends on MICROCODE
1318	select FW_LOADER
1319	---help---
1320	  If you select this option, microcode patch loading support for AMD
1321	  processors will be enabled.
1322
1323config MICROCODE_OLD_INTERFACE
1324	def_bool y
1325	depends on MICROCODE
1326
1327config X86_MSR
1328	tristate "/dev/cpu/*/msr - Model-specific register support"
1329	---help---
1330	  This device gives privileged processes access to the x86
1331	  Model-Specific Registers (MSRs).  It is a character device with
1332	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1333	  MSR accesses are directed to a specific CPU on multi-processor
1334	  systems.
1335
1336config X86_CPUID
1337	tristate "/dev/cpu/*/cpuid - CPU information support"
1338	---help---
1339	  This device gives processes access to the x86 CPUID instruction to
1340	  be executed on a specific processor.  It is a character device
1341	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1342	  /dev/cpu/31/cpuid.
1343
1344choice
1345	prompt "High Memory Support"
1346	default HIGHMEM4G
1347	depends on X86_32
1348
1349config NOHIGHMEM
1350	bool "off"
1351	---help---
1352	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1353	  However, the address space of 32-bit x86 processors is only 4
1354	  Gigabytes large. That means that, if you have a large amount of
1355	  physical memory, not all of it can be "permanently mapped" by the
1356	  kernel. The physical memory that's not permanently mapped is called
1357	  "high memory".
1358
1359	  If you are compiling a kernel which will never run on a machine with
1360	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1361	  choice and suitable for most users). This will result in a "3GB/1GB"
1362	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1363	  space and the remaining part of the 4GB virtual memory space is used
1364	  by the kernel to permanently map as much physical memory as
1365	  possible.
1366
1367	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1368	  answer "4GB" here.
1369
1370	  If more than 4 Gigabytes is used then answer "64GB" here. This
1371	  selection turns Intel PAE (Physical Address Extension) mode on.
1372	  PAE implements 3-level paging on IA32 processors. PAE is fully
1373	  supported by Linux, PAE mode is implemented on all recent Intel
1374	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1375	  then the kernel will not boot on CPUs that don't support PAE!
1376
1377	  The actual amount of total physical memory will either be
1378	  auto detected or can be forced by using a kernel command line option
1379	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1380	  your boot loader (lilo or loadlin) about how to pass options to the
1381	  kernel at boot time.)
1382
1383	  If unsure, say "off".
1384
1385config HIGHMEM4G
1386	bool "4GB"
1387	---help---
1388	  Select this if you have a 32-bit processor and between 1 and 4
1389	  gigabytes of physical RAM.
1390
1391config HIGHMEM64G
1392	bool "64GB"
1393	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1394	select X86_PAE
1395	---help---
1396	  Select this if you have a 32-bit processor and more than 4
1397	  gigabytes of physical RAM.
1398
1399endchoice
1400
1401choice
1402	prompt "Memory split" if EXPERT
1403	default VMSPLIT_3G
1404	depends on X86_32
1405	---help---
1406	  Select the desired split between kernel and user memory.
1407
1408	  If the address range available to the kernel is less than the
1409	  physical memory installed, the remaining memory will be available
1410	  as "high memory". Accessing high memory is a little more costly
1411	  than low memory, as it needs to be mapped into the kernel first.
1412	  Note that increasing the kernel address space limits the range
1413	  available to user programs, making the address space there
1414	  tighter.  Selecting anything other than the default 3G/1G split
1415	  will also likely make your kernel incompatible with binary-only
1416	  kernel modules.
1417
1418	  If you are not absolutely sure what you are doing, leave this
1419	  option alone!
1420
1421	config VMSPLIT_3G
1422		bool "3G/1G user/kernel split"
1423	config VMSPLIT_3G_OPT
1424		depends on !X86_PAE
1425		bool "3G/1G user/kernel split (for full 1G low memory)"
1426	config VMSPLIT_2G
1427		bool "2G/2G user/kernel split"
1428	config VMSPLIT_2G_OPT
1429		depends on !X86_PAE
1430		bool "2G/2G user/kernel split (for full 2G low memory)"
1431	config VMSPLIT_1G
1432		bool "1G/3G user/kernel split"
1433endchoice
1434
1435config PAGE_OFFSET
1436	hex
1437	default 0xB0000000 if VMSPLIT_3G_OPT
1438	default 0x80000000 if VMSPLIT_2G
1439	default 0x78000000 if VMSPLIT_2G_OPT
1440	default 0x40000000 if VMSPLIT_1G
1441	default 0xC0000000
1442	depends on X86_32
1443
1444config HIGHMEM
1445	def_bool y
1446	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1447
1448config X86_PAE
1449	bool "PAE (Physical Address Extension) Support"
1450	depends on X86_32 && !HIGHMEM4G
1451	select PHYS_ADDR_T_64BIT
1452	select SWIOTLB
1453	---help---
1454	  PAE is required for NX support, and furthermore enables
1455	  larger swapspace support for non-overcommit purposes. It
1456	  has the cost of more pagetable lookup overhead, and also
1457	  consumes more pagetable space per process.
1458
1459config X86_5LEVEL
1460	bool "Enable 5-level page tables support"
1461	select DYNAMIC_MEMORY_LAYOUT
1462	select SPARSEMEM_VMEMMAP
1463	depends on X86_64
1464	---help---
1465	  5-level paging enables access to larger address space:
1466	  upto 128 PiB of virtual address space and 4 PiB of
1467	  physical address space.
1468
1469	  It will be supported by future Intel CPUs.
1470
1471	  A kernel with the option enabled can be booted on machines that
1472	  support 4- or 5-level paging.
1473
1474	  See Documentation/x86/x86_64/5level-paging.txt for more
1475	  information.
1476
1477	  Say N if unsure.
1478
1479config X86_DIRECT_GBPAGES
1480	def_bool y
1481	depends on X86_64 && !DEBUG_PAGEALLOC
1482	---help---
1483	  Certain kernel features effectively disable kernel
1484	  linear 1 GB mappings (even if the CPU otherwise
1485	  supports them), so don't confuse the user by printing
1486	  that we have them enabled.
1487
1488config X86_CPA_STATISTICS
1489	bool "Enable statistic for Change Page Attribute"
1490	depends on DEBUG_FS
1491	---help---
1492	  Expose statistics about the Change Page Attribute mechanims, which
1493	  helps to determine the effectivness of preserving large and huge
1494	  page mappings when mapping protections are changed.
1495
1496config ARCH_HAS_MEM_ENCRYPT
1497	def_bool y
1498
1499config AMD_MEM_ENCRYPT
1500	bool "AMD Secure Memory Encryption (SME) support"
1501	depends on X86_64 && CPU_SUP_AMD
1502	select DYNAMIC_PHYSICAL_MASK
1503	---help---
1504	  Say yes to enable support for the encryption of system memory.
1505	  This requires an AMD processor that supports Secure Memory
1506	  Encryption (SME).
1507
1508config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1509	bool "Activate AMD Secure Memory Encryption (SME) by default"
1510	default y
1511	depends on AMD_MEM_ENCRYPT
1512	---help---
1513	  Say yes to have system memory encrypted by default if running on
1514	  an AMD processor that supports Secure Memory Encryption (SME).
1515
1516	  If set to Y, then the encryption of system memory can be
1517	  deactivated with the mem_encrypt=off command line option.
1518
1519	  If set to N, then the encryption of system memory can be
1520	  activated with the mem_encrypt=on command line option.
1521
1522config ARCH_USE_MEMREMAP_PROT
1523	def_bool y
1524	depends on AMD_MEM_ENCRYPT
1525
1526# Common NUMA Features
1527config NUMA
1528	bool "Numa Memory Allocation and Scheduler Support"
1529	depends on SMP
1530	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1531	default y if X86_BIGSMP
1532	---help---
1533	  Enable NUMA (Non Uniform Memory Access) support.
1534
1535	  The kernel will try to allocate memory used by a CPU on the
1536	  local memory controller of the CPU and add some more
1537	  NUMA awareness to the kernel.
1538
1539	  For 64-bit this is recommended if the system is Intel Core i7
1540	  (or later), AMD Opteron, or EM64T NUMA.
1541
1542	  For 32-bit this is only needed if you boot a 32-bit
1543	  kernel on a 64-bit NUMA platform.
1544
1545	  Otherwise, you should say N.
1546
1547config AMD_NUMA
1548	def_bool y
1549	prompt "Old style AMD Opteron NUMA detection"
1550	depends on X86_64 && NUMA && PCI
1551	---help---
1552	  Enable AMD NUMA node topology detection.  You should say Y here if
1553	  you have a multi processor AMD system. This uses an old method to
1554	  read the NUMA configuration directly from the builtin Northbridge
1555	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1556	  which also takes priority if both are compiled in.
1557
1558config X86_64_ACPI_NUMA
1559	def_bool y
1560	prompt "ACPI NUMA detection"
1561	depends on X86_64 && NUMA && ACPI && PCI
1562	select ACPI_NUMA
1563	---help---
1564	  Enable ACPI SRAT based node topology detection.
1565
1566# Some NUMA nodes have memory ranges that span
1567# other nodes.  Even though a pfn is valid and
1568# between a node's start and end pfns, it may not
1569# reside on that node.  See memmap_init_zone()
1570# for details.
1571config NODES_SPAN_OTHER_NODES
1572	def_bool y
1573	depends on X86_64_ACPI_NUMA
1574
1575config NUMA_EMU
1576	bool "NUMA emulation"
1577	depends on NUMA
1578	---help---
1579	  Enable NUMA emulation. A flat machine will be split
1580	  into virtual nodes when booted with "numa=fake=N", where N is the
1581	  number of nodes. This is only useful for debugging.
1582
1583config NODES_SHIFT
1584	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1585	range 1 10
1586	default "10" if MAXSMP
1587	default "6" if X86_64
1588	default "3"
1589	depends on NEED_MULTIPLE_NODES
1590	---help---
1591	  Specify the maximum number of NUMA Nodes available on the target
1592	  system.  Increases memory reserved to accommodate various tables.
1593
1594config ARCH_HAVE_MEMORY_PRESENT
1595	def_bool y
1596	depends on X86_32 && DISCONTIGMEM
1597
1598config ARCH_FLATMEM_ENABLE
1599	def_bool y
1600	depends on X86_32 && !NUMA
1601
1602config ARCH_DISCONTIGMEM_ENABLE
1603	def_bool y
1604	depends on NUMA && X86_32
1605
1606config ARCH_DISCONTIGMEM_DEFAULT
1607	def_bool y
1608	depends on NUMA && X86_32
1609
1610config ARCH_SPARSEMEM_ENABLE
1611	def_bool y
1612	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1613	select SPARSEMEM_STATIC if X86_32
1614	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1615
1616config ARCH_SPARSEMEM_DEFAULT
1617	def_bool y
1618	depends on X86_64
1619
1620config ARCH_SELECT_MEMORY_MODEL
1621	def_bool y
1622	depends on ARCH_SPARSEMEM_ENABLE
1623
1624config ARCH_MEMORY_PROBE
1625	bool "Enable sysfs memory/probe interface"
1626	depends on X86_64 && MEMORY_HOTPLUG
1627	help
1628	  This option enables a sysfs memory/probe interface for testing.
1629	  See Documentation/memory-hotplug.txt for more information.
1630	  If you are unsure how to answer this question, answer N.
1631
1632config ARCH_PROC_KCORE_TEXT
1633	def_bool y
1634	depends on X86_64 && PROC_KCORE
1635
1636config ILLEGAL_POINTER_VALUE
1637       hex
1638       default 0 if X86_32
1639       default 0xdead000000000000 if X86_64
1640
1641config X86_PMEM_LEGACY_DEVICE
1642	bool
1643
1644config X86_PMEM_LEGACY
1645	tristate "Support non-standard NVDIMMs and ADR protected memory"
1646	depends on PHYS_ADDR_T_64BIT
1647	depends on BLK_DEV
1648	select X86_PMEM_LEGACY_DEVICE
1649	select LIBNVDIMM
1650	help
1651	  Treat memory marked using the non-standard e820 type of 12 as used
1652	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1653	  The kernel will offer these regions to the 'pmem' driver so
1654	  they can be used for persistent storage.
1655
1656	  Say Y if unsure.
1657
1658config HIGHPTE
1659	bool "Allocate 3rd-level pagetables from highmem"
1660	depends on HIGHMEM
1661	---help---
1662	  The VM uses one page table entry for each page of physical memory.
1663	  For systems with a lot of RAM, this can be wasteful of precious
1664	  low memory.  Setting this option will put user-space page table
1665	  entries in high memory.
1666
1667config X86_CHECK_BIOS_CORRUPTION
1668	bool "Check for low memory corruption"
1669	---help---
1670	  Periodically check for memory corruption in low memory, which
1671	  is suspected to be caused by BIOS.  Even when enabled in the
1672	  configuration, it is disabled at runtime.  Enable it by
1673	  setting "memory_corruption_check=1" on the kernel command
1674	  line.  By default it scans the low 64k of memory every 60
1675	  seconds; see the memory_corruption_check_size and
1676	  memory_corruption_check_period parameters in
1677	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1678
1679	  When enabled with the default parameters, this option has
1680	  almost no overhead, as it reserves a relatively small amount
1681	  of memory and scans it infrequently.  It both detects corruption
1682	  and prevents it from affecting the running system.
1683
1684	  It is, however, intended as a diagnostic tool; if repeatable
1685	  BIOS-originated corruption always affects the same memory,
1686	  you can use memmap= to prevent the kernel from using that
1687	  memory.
1688
1689config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1690	bool "Set the default setting of memory_corruption_check"
1691	depends on X86_CHECK_BIOS_CORRUPTION
1692	default y
1693	---help---
1694	  Set whether the default state of memory_corruption_check is
1695	  on or off.
1696
1697config X86_RESERVE_LOW
1698	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1699	default 64
1700	range 4 640
1701	---help---
1702	  Specify the amount of low memory to reserve for the BIOS.
1703
1704	  The first page contains BIOS data structures that the kernel
1705	  must not use, so that page must always be reserved.
1706
1707	  By default we reserve the first 64K of physical RAM, as a
1708	  number of BIOSes are known to corrupt that memory range
1709	  during events such as suspend/resume or monitor cable
1710	  insertion, so it must not be used by the kernel.
1711
1712	  You can set this to 4 if you are absolutely sure that you
1713	  trust the BIOS to get all its memory reservations and usages
1714	  right.  If you know your BIOS have problems beyond the
1715	  default 64K area, you can set this to 640 to avoid using the
1716	  entire low memory range.
1717
1718	  If you have doubts about the BIOS (e.g. suspend/resume does
1719	  not work or there's kernel crashes after certain hardware
1720	  hotplug events) then you might want to enable
1721	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1722	  typical corruption patterns.
1723
1724	  Leave this to the default value of 64 if you are unsure.
1725
1726config MATH_EMULATION
1727	bool
1728	depends on MODIFY_LDT_SYSCALL
1729	prompt "Math emulation" if X86_32
1730	---help---
1731	  Linux can emulate a math coprocessor (used for floating point
1732	  operations) if you don't have one. 486DX and Pentium processors have
1733	  a math coprocessor built in, 486SX and 386 do not, unless you added
1734	  a 487DX or 387, respectively. (The messages during boot time can
1735	  give you some hints here ["man dmesg"].) Everyone needs either a
1736	  coprocessor or this emulation.
1737
1738	  If you don't have a math coprocessor, you need to say Y here; if you
1739	  say Y here even though you have a coprocessor, the coprocessor will
1740	  be used nevertheless. (This behavior can be changed with the kernel
1741	  command line option "no387", which comes handy if your coprocessor
1742	  is broken. Try "man bootparam" or see the documentation of your boot
1743	  loader (lilo or loadlin) about how to pass options to the kernel at
1744	  boot time.) This means that it is a good idea to say Y here if you
1745	  intend to use this kernel on different machines.
1746
1747	  More information about the internals of the Linux math coprocessor
1748	  emulation can be found in <file:arch/x86/math-emu/README>.
1749
1750	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1751	  kernel, it won't hurt.
1752
1753config MTRR
1754	def_bool y
1755	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1756	---help---
1757	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1758	  the Memory Type Range Registers (MTRRs) may be used to control
1759	  processor access to memory ranges. This is most useful if you have
1760	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1761	  allows bus write transfers to be combined into a larger transfer
1762	  before bursting over the PCI/AGP bus. This can increase performance
1763	  of image write operations 2.5 times or more. Saying Y here creates a
1764	  /proc/mtrr file which may be used to manipulate your processor's
1765	  MTRRs. Typically the X server should use this.
1766
1767	  This code has a reasonably generic interface so that similar
1768	  control registers on other processors can be easily supported
1769	  as well:
1770
1771	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1772	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1773	  these, the ARRs are used to emulate the MTRRs.
1774	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1775	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1776	  write-combining. All of these processors are supported by this code
1777	  and it makes sense to say Y here if you have one of them.
1778
1779	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1780	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1781	  can lead to all sorts of problems, so it's good to say Y here.
1782
1783	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1784	  just add about 9 KB to your kernel.
1785
1786	  See <file:Documentation/x86/mtrr.txt> for more information.
1787
1788config MTRR_SANITIZER
1789	def_bool y
1790	prompt "MTRR cleanup support"
1791	depends on MTRR
1792	---help---
1793	  Convert MTRR layout from continuous to discrete, so X drivers can
1794	  add writeback entries.
1795
1796	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1797	  The largest mtrr entry size for a continuous block can be set with
1798	  mtrr_chunk_size.
1799
1800	  If unsure, say Y.
1801
1802config MTRR_SANITIZER_ENABLE_DEFAULT
1803	int "MTRR cleanup enable value (0-1)"
1804	range 0 1
1805	default "0"
1806	depends on MTRR_SANITIZER
1807	---help---
1808	  Enable mtrr cleanup default value
1809
1810config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1811	int "MTRR cleanup spare reg num (0-7)"
1812	range 0 7
1813	default "1"
1814	depends on MTRR_SANITIZER
1815	---help---
1816	  mtrr cleanup spare entries default, it can be changed via
1817	  mtrr_spare_reg_nr=N on the kernel command line.
1818
1819config X86_PAT
1820	def_bool y
1821	prompt "x86 PAT support" if EXPERT
1822	depends on MTRR
1823	---help---
1824	  Use PAT attributes to setup page level cache control.
1825
1826	  PATs are the modern equivalents of MTRRs and are much more
1827	  flexible than MTRRs.
1828
1829	  Say N here if you see bootup problems (boot crash, boot hang,
1830	  spontaneous reboots) or a non-working video driver.
1831
1832	  If unsure, say Y.
1833
1834config ARCH_USES_PG_UNCACHED
1835	def_bool y
1836	depends on X86_PAT
1837
1838config ARCH_RANDOM
1839	def_bool y
1840	prompt "x86 architectural random number generator" if EXPERT
1841	---help---
1842	  Enable the x86 architectural RDRAND instruction
1843	  (Intel Bull Mountain technology) to generate random numbers.
1844	  If supported, this is a high bandwidth, cryptographically
1845	  secure hardware random number generator.
1846
1847config X86_SMAP
1848	def_bool y
1849	prompt "Supervisor Mode Access Prevention" if EXPERT
1850	---help---
1851	  Supervisor Mode Access Prevention (SMAP) is a security
1852	  feature in newer Intel processors.  There is a small
1853	  performance cost if this enabled and turned on; there is
1854	  also a small increase in the kernel size if this is enabled.
1855
1856	  If unsure, say Y.
1857
1858config X86_INTEL_UMIP
1859	def_bool y
1860	depends on CPU_SUP_INTEL
1861	prompt "Intel User Mode Instruction Prevention" if EXPERT
1862	---help---
1863	  The User Mode Instruction Prevention (UMIP) is a security
1864	  feature in newer Intel processors. If enabled, a general
1865	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1866	  or STR instructions are executed in user mode. These instructions
1867	  unnecessarily expose information about the hardware state.
1868
1869	  The vast majority of applications do not use these instructions.
1870	  For the very few that do, software emulation is provided in
1871	  specific cases in protected and virtual-8086 modes. Emulated
1872	  results are dummy.
1873
1874config X86_INTEL_MPX
1875	prompt "Intel MPX (Memory Protection Extensions)"
1876	def_bool n
1877	# Note: only available in 64-bit mode due to VMA flags shortage
1878	depends on CPU_SUP_INTEL && X86_64
1879	select ARCH_USES_HIGH_VMA_FLAGS
1880	---help---
1881	  MPX provides hardware features that can be used in
1882	  conjunction with compiler-instrumented code to check
1883	  memory references.  It is designed to detect buffer
1884	  overflow or underflow bugs.
1885
1886	  This option enables running applications which are
1887	  instrumented or otherwise use MPX.  It does not use MPX
1888	  itself inside the kernel or to protect the kernel
1889	  against bad memory references.
1890
1891	  Enabling this option will make the kernel larger:
1892	  ~8k of kernel text and 36 bytes of data on a 64-bit
1893	  defconfig.  It adds a long to the 'mm_struct' which
1894	  will increase the kernel memory overhead of each
1895	  process and adds some branches to paths used during
1896	  exec() and munmap().
1897
1898	  For details, see Documentation/x86/intel_mpx.txt
1899
1900	  If unsure, say N.
1901
1902config X86_INTEL_MEMORY_PROTECTION_KEYS
1903	prompt "Intel Memory Protection Keys"
1904	def_bool y
1905	# Note: only available in 64-bit mode
1906	depends on CPU_SUP_INTEL && X86_64
1907	select ARCH_USES_HIGH_VMA_FLAGS
1908	select ARCH_HAS_PKEYS
1909	---help---
1910	  Memory Protection Keys provides a mechanism for enforcing
1911	  page-based protections, but without requiring modification of the
1912	  page tables when an application changes protection domains.
1913
1914	  For details, see Documentation/x86/protection-keys.txt
1915
1916	  If unsure, say y.
1917
1918config EFI
1919	bool "EFI runtime service support"
1920	depends on ACPI
1921	select UCS2_STRING
1922	select EFI_RUNTIME_WRAPPERS
1923	---help---
1924	  This enables the kernel to use EFI runtime services that are
1925	  available (such as the EFI variable services).
1926
1927	  This option is only useful on systems that have EFI firmware.
1928	  In addition, you should use the latest ELILO loader available
1929	  at <http://elilo.sourceforge.net> in order to take advantage
1930	  of EFI runtime services. However, even with this option, the
1931	  resultant kernel should continue to boot on existing non-EFI
1932	  platforms.
1933
1934config EFI_STUB
1935       bool "EFI stub support"
1936       depends on EFI && !X86_USE_3DNOW
1937       select RELOCATABLE
1938       ---help---
1939          This kernel feature allows a bzImage to be loaded directly
1940	  by EFI firmware without the use of a bootloader.
1941
1942	  See Documentation/efi-stub.txt for more information.
1943
1944config EFI_MIXED
1945	bool "EFI mixed-mode support"
1946	depends on EFI_STUB && X86_64
1947	---help---
1948	   Enabling this feature allows a 64-bit kernel to be booted
1949	   on a 32-bit firmware, provided that your CPU supports 64-bit
1950	   mode.
1951
1952	   Note that it is not possible to boot a mixed-mode enabled
1953	   kernel via the EFI boot stub - a bootloader that supports
1954	   the EFI handover protocol must be used.
1955
1956	   If unsure, say N.
1957
1958config SECCOMP
1959	def_bool y
1960	prompt "Enable seccomp to safely compute untrusted bytecode"
1961	---help---
1962	  This kernel feature is useful for number crunching applications
1963	  that may need to compute untrusted bytecode during their
1964	  execution. By using pipes or other transports made available to
1965	  the process as file descriptors supporting the read/write
1966	  syscalls, it's possible to isolate those applications in
1967	  their own address space using seccomp. Once seccomp is
1968	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1969	  and the task is only allowed to execute a few safe syscalls
1970	  defined by each seccomp mode.
1971
1972	  If unsure, say Y. Only embedded should say N here.
1973
1974source kernel/Kconfig.hz
1975
1976config KEXEC
1977	bool "kexec system call"
1978	select KEXEC_CORE
1979	---help---
1980	  kexec is a system call that implements the ability to shutdown your
1981	  current kernel, and to start another kernel.  It is like a reboot
1982	  but it is independent of the system firmware.   And like a reboot
1983	  you can start any kernel with it, not just Linux.
1984
1985	  The name comes from the similarity to the exec system call.
1986
1987	  It is an ongoing process to be certain the hardware in a machine
1988	  is properly shutdown, so do not be surprised if this code does not
1989	  initially work for you.  As of this writing the exact hardware
1990	  interface is strongly in flux, so no good recommendation can be
1991	  made.
1992
1993config KEXEC_FILE
1994	bool "kexec file based system call"
1995	select KEXEC_CORE
1996	select BUILD_BIN2C
1997	depends on X86_64
1998	depends on CRYPTO=y
1999	depends on CRYPTO_SHA256=y
2000	---help---
2001	  This is new version of kexec system call. This system call is
2002	  file based and takes file descriptors as system call argument
2003	  for kernel and initramfs as opposed to list of segments as
2004	  accepted by previous system call.
2005
2006config ARCH_HAS_KEXEC_PURGATORY
2007	def_bool KEXEC_FILE
2008
2009config KEXEC_VERIFY_SIG
2010	bool "Verify kernel signature during kexec_file_load() syscall"
2011	depends on KEXEC_FILE
2012	---help---
2013	  This option makes kernel signature verification mandatory for
2014	  the kexec_file_load() syscall.
2015
2016	  In addition to that option, you need to enable signature
2017	  verification for the corresponding kernel image type being
2018	  loaded in order for this to work.
2019
2020config KEXEC_BZIMAGE_VERIFY_SIG
2021	bool "Enable bzImage signature verification support"
2022	depends on KEXEC_VERIFY_SIG
2023	depends on SIGNED_PE_FILE_VERIFICATION
2024	select SYSTEM_TRUSTED_KEYRING
2025	---help---
2026	  Enable bzImage signature verification support.
2027
2028config CRASH_DUMP
2029	bool "kernel crash dumps"
2030	depends on X86_64 || (X86_32 && HIGHMEM)
2031	---help---
2032	  Generate crash dump after being started by kexec.
2033	  This should be normally only set in special crash dump kernels
2034	  which are loaded in the main kernel with kexec-tools into
2035	  a specially reserved region and then later executed after
2036	  a crash by kdump/kexec. The crash dump kernel must be compiled
2037	  to a memory address not used by the main kernel or BIOS using
2038	  PHYSICAL_START, or it must be built as a relocatable image
2039	  (CONFIG_RELOCATABLE=y).
2040	  For more details see Documentation/kdump/kdump.txt
2041
2042config KEXEC_JUMP
2043	bool "kexec jump"
2044	depends on KEXEC && HIBERNATION
2045	---help---
2046	  Jump between original kernel and kexeced kernel and invoke
2047	  code in physical address mode via KEXEC
2048
2049config PHYSICAL_START
2050	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2051	default "0x1000000"
2052	---help---
2053	  This gives the physical address where the kernel is loaded.
2054
2055	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2056	  bzImage will decompress itself to above physical address and
2057	  run from there. Otherwise, bzImage will run from the address where
2058	  it has been loaded by the boot loader and will ignore above physical
2059	  address.
2060
2061	  In normal kdump cases one does not have to set/change this option
2062	  as now bzImage can be compiled as a completely relocatable image
2063	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2064	  address. This option is mainly useful for the folks who don't want
2065	  to use a bzImage for capturing the crash dump and want to use a
2066	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2067	  to be specifically compiled to run from a specific memory area
2068	  (normally a reserved region) and this option comes handy.
2069
2070	  So if you are using bzImage for capturing the crash dump,
2071	  leave the value here unchanged to 0x1000000 and set
2072	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2073	  for capturing the crash dump change this value to start of
2074	  the reserved region.  In other words, it can be set based on
2075	  the "X" value as specified in the "crashkernel=YM@XM"
2076	  command line boot parameter passed to the panic-ed
2077	  kernel. Please take a look at Documentation/kdump/kdump.txt
2078	  for more details about crash dumps.
2079
2080	  Usage of bzImage for capturing the crash dump is recommended as
2081	  one does not have to build two kernels. Same kernel can be used
2082	  as production kernel and capture kernel. Above option should have
2083	  gone away after relocatable bzImage support is introduced. But it
2084	  is present because there are users out there who continue to use
2085	  vmlinux for dump capture. This option should go away down the
2086	  line.
2087
2088	  Don't change this unless you know what you are doing.
2089
2090config RELOCATABLE
2091	bool "Build a relocatable kernel"
2092	default y
2093	---help---
2094	  This builds a kernel image that retains relocation information
2095	  so it can be loaded someplace besides the default 1MB.
2096	  The relocations tend to make the kernel binary about 10% larger,
2097	  but are discarded at runtime.
2098
2099	  One use is for the kexec on panic case where the recovery kernel
2100	  must live at a different physical address than the primary
2101	  kernel.
2102
2103	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2104	  it has been loaded at and the compile time physical address
2105	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2106
2107config RANDOMIZE_BASE
2108	bool "Randomize the address of the kernel image (KASLR)"
2109	depends on RELOCATABLE
2110	default y
2111	---help---
2112	  In support of Kernel Address Space Layout Randomization (KASLR),
2113	  this randomizes the physical address at which the kernel image
2114	  is decompressed and the virtual address where the kernel
2115	  image is mapped, as a security feature that deters exploit
2116	  attempts relying on knowledge of the location of kernel
2117	  code internals.
2118
2119	  On 64-bit, the kernel physical and virtual addresses are
2120	  randomized separately. The physical address will be anywhere
2121	  between 16MB and the top of physical memory (up to 64TB). The
2122	  virtual address will be randomized from 16MB up to 1GB (9 bits
2123	  of entropy). Note that this also reduces the memory space
2124	  available to kernel modules from 1.5GB to 1GB.
2125
2126	  On 32-bit, the kernel physical and virtual addresses are
2127	  randomized together. They will be randomized from 16MB up to
2128	  512MB (8 bits of entropy).
2129
2130	  Entropy is generated using the RDRAND instruction if it is
2131	  supported. If RDTSC is supported, its value is mixed into
2132	  the entropy pool as well. If neither RDRAND nor RDTSC are
2133	  supported, then entropy is read from the i8254 timer. The
2134	  usable entropy is limited by the kernel being built using
2135	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2136	  minimum of 2MB. As a result, only 10 bits of entropy are
2137	  theoretically possible, but the implementations are further
2138	  limited due to memory layouts.
2139
2140	  If unsure, say Y.
2141
2142# Relocation on x86 needs some additional build support
2143config X86_NEED_RELOCS
2144	def_bool y
2145	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2146
2147config PHYSICAL_ALIGN
2148	hex "Alignment value to which kernel should be aligned"
2149	default "0x200000"
2150	range 0x2000 0x1000000 if X86_32
2151	range 0x200000 0x1000000 if X86_64
2152	---help---
2153	  This value puts the alignment restrictions on physical address
2154	  where kernel is loaded and run from. Kernel is compiled for an
2155	  address which meets above alignment restriction.
2156
2157	  If bootloader loads the kernel at a non-aligned address and
2158	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2159	  address aligned to above value and run from there.
2160
2161	  If bootloader loads the kernel at a non-aligned address and
2162	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2163	  load address and decompress itself to the address it has been
2164	  compiled for and run from there. The address for which kernel is
2165	  compiled already meets above alignment restrictions. Hence the
2166	  end result is that kernel runs from a physical address meeting
2167	  above alignment restrictions.
2168
2169	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2170	  this value must be a multiple of 0x200000.
2171
2172	  Don't change this unless you know what you are doing.
2173
2174config DYNAMIC_MEMORY_LAYOUT
2175	bool
2176	---help---
2177	  This option makes base addresses of vmalloc and vmemmap as well as
2178	  __PAGE_OFFSET movable during boot.
2179
2180config RANDOMIZE_MEMORY
2181	bool "Randomize the kernel memory sections"
2182	depends on X86_64
2183	depends on RANDOMIZE_BASE
2184	select DYNAMIC_MEMORY_LAYOUT
2185	default RANDOMIZE_BASE
2186	---help---
2187	   Randomizes the base virtual address of kernel memory sections
2188	   (physical memory mapping, vmalloc & vmemmap). This security feature
2189	   makes exploits relying on predictable memory locations less reliable.
2190
2191	   The order of allocations remains unchanged. Entropy is generated in
2192	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2193	   configuration have in average 30,000 different possible virtual
2194	   addresses for each memory section.
2195
2196	   If unsure, say Y.
2197
2198config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2199	hex "Physical memory mapping padding" if EXPERT
2200	depends on RANDOMIZE_MEMORY
2201	default "0xa" if MEMORY_HOTPLUG
2202	default "0x0"
2203	range 0x1 0x40 if MEMORY_HOTPLUG
2204	range 0x0 0x40
2205	---help---
2206	   Define the padding in terabytes added to the existing physical
2207	   memory size during kernel memory randomization. It is useful
2208	   for memory hotplug support but reduces the entropy available for
2209	   address randomization.
2210
2211	   If unsure, leave at the default value.
2212
2213config HOTPLUG_CPU
2214	bool "Support for hot-pluggable CPUs"
2215	depends on SMP
2216	---help---
2217	  Say Y here to allow turning CPUs off and on. CPUs can be
2218	  controlled through /sys/devices/system/cpu.
2219	  ( Note: power management support will enable this option
2220	    automatically on SMP systems. )
2221	  Say N if you want to disable CPU hotplug.
2222
2223config BOOTPARAM_HOTPLUG_CPU0
2224	bool "Set default setting of cpu0_hotpluggable"
2225	depends on HOTPLUG_CPU
2226	---help---
2227	  Set whether default state of cpu0_hotpluggable is on or off.
2228
2229	  Say Y here to enable CPU0 hotplug by default. If this switch
2230	  is turned on, there is no need to give cpu0_hotplug kernel
2231	  parameter and the CPU0 hotplug feature is enabled by default.
2232
2233	  Please note: there are two known CPU0 dependencies if you want
2234	  to enable the CPU0 hotplug feature either by this switch or by
2235	  cpu0_hotplug kernel parameter.
2236
2237	  First, resume from hibernate or suspend always starts from CPU0.
2238	  So hibernate and suspend are prevented if CPU0 is offline.
2239
2240	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2241	  offline if any interrupt can not migrate out of CPU0. There may
2242	  be other CPU0 dependencies.
2243
2244	  Please make sure the dependencies are under your control before
2245	  you enable this feature.
2246
2247	  Say N if you don't want to enable CPU0 hotplug feature by default.
2248	  You still can enable the CPU0 hotplug feature at boot by kernel
2249	  parameter cpu0_hotplug.
2250
2251config DEBUG_HOTPLUG_CPU0
2252	def_bool n
2253	prompt "Debug CPU0 hotplug"
2254	depends on HOTPLUG_CPU
2255	---help---
2256	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2257	  soon as possible and boots up userspace with CPU0 offlined. User
2258	  can online CPU0 back after boot time.
2259
2260	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2261	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2262	  compilation or giving cpu0_hotplug kernel parameter at boot.
2263
2264	  If unsure, say N.
2265
2266config COMPAT_VDSO
2267	def_bool n
2268	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2269	depends on COMPAT_32
2270	---help---
2271	  Certain buggy versions of glibc will crash if they are
2272	  presented with a 32-bit vDSO that is not mapped at the address
2273	  indicated in its segment table.
2274
2275	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2276	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2277	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2278	  the only released version with the bug, but OpenSUSE 9
2279	  contains a buggy "glibc 2.3.2".
2280
2281	  The symptom of the bug is that everything crashes on startup, saying:
2282	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2283
2284	  Saying Y here changes the default value of the vdso32 boot
2285	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2286	  This works around the glibc bug but hurts performance.
2287
2288	  If unsure, say N: if you are compiling your own kernel, you
2289	  are unlikely to be using a buggy version of glibc.
2290
2291choice
2292	prompt "vsyscall table for legacy applications"
2293	depends on X86_64
2294	default LEGACY_VSYSCALL_EMULATE
2295	help
2296	  Legacy user code that does not know how to find the vDSO expects
2297	  to be able to issue three syscalls by calling fixed addresses in
2298	  kernel space. Since this location is not randomized with ASLR,
2299	  it can be used to assist security vulnerability exploitation.
2300
2301	  This setting can be changed at boot time via the kernel command
2302	  line parameter vsyscall=[emulate|none].
2303
2304	  On a system with recent enough glibc (2.14 or newer) and no
2305	  static binaries, you can say None without a performance penalty
2306	  to improve security.
2307
2308	  If unsure, select "Emulate".
2309
2310	config LEGACY_VSYSCALL_EMULATE
2311		bool "Emulate"
2312		help
2313		  The kernel traps and emulates calls into the fixed
2314		  vsyscall address mapping. This makes the mapping
2315		  non-executable, but it still contains known contents,
2316		  which could be used in certain rare security vulnerability
2317		  exploits. This configuration is recommended when userspace
2318		  still uses the vsyscall area.
2319
2320	config LEGACY_VSYSCALL_NONE
2321		bool "None"
2322		help
2323		  There will be no vsyscall mapping at all. This will
2324		  eliminate any risk of ASLR bypass due to the vsyscall
2325		  fixed address mapping. Attempts to use the vsyscalls
2326		  will be reported to dmesg, so that either old or
2327		  malicious userspace programs can be identified.
2328
2329endchoice
2330
2331config CMDLINE_BOOL
2332	bool "Built-in kernel command line"
2333	---help---
2334	  Allow for specifying boot arguments to the kernel at
2335	  build time.  On some systems (e.g. embedded ones), it is
2336	  necessary or convenient to provide some or all of the
2337	  kernel boot arguments with the kernel itself (that is,
2338	  to not rely on the boot loader to provide them.)
2339
2340	  To compile command line arguments into the kernel,
2341	  set this option to 'Y', then fill in the
2342	  boot arguments in CONFIG_CMDLINE.
2343
2344	  Systems with fully functional boot loaders (i.e. non-embedded)
2345	  should leave this option set to 'N'.
2346
2347config CMDLINE
2348	string "Built-in kernel command string"
2349	depends on CMDLINE_BOOL
2350	default ""
2351	---help---
2352	  Enter arguments here that should be compiled into the kernel
2353	  image and used at boot time.  If the boot loader provides a
2354	  command line at boot time, it is appended to this string to
2355	  form the full kernel command line, when the system boots.
2356
2357	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2358	  change this behavior.
2359
2360	  In most cases, the command line (whether built-in or provided
2361	  by the boot loader) should specify the device for the root
2362	  file system.
2363
2364config CMDLINE_OVERRIDE
2365	bool "Built-in command line overrides boot loader arguments"
2366	depends on CMDLINE_BOOL
2367	---help---
2368	  Set this option to 'Y' to have the kernel ignore the boot loader
2369	  command line, and use ONLY the built-in command line.
2370
2371	  This is used to work around broken boot loaders.  This should
2372	  be set to 'N' under normal conditions.
2373
2374config MODIFY_LDT_SYSCALL
2375	bool "Enable the LDT (local descriptor table)" if EXPERT
2376	default y
2377	---help---
2378	  Linux can allow user programs to install a per-process x86
2379	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2380	  call.  This is required to run 16-bit or segmented code such as
2381	  DOSEMU or some Wine programs.  It is also used by some very old
2382	  threading libraries.
2383
2384	  Enabling this feature adds a small amount of overhead to
2385	  context switches and increases the low-level kernel attack
2386	  surface.  Disabling it removes the modify_ldt(2) system call.
2387
2388	  Saying 'N' here may make sense for embedded or server kernels.
2389
2390source "kernel/livepatch/Kconfig"
2391
2392endmenu
2393
2394config ARCH_HAS_ADD_PAGES
2395	def_bool y
2396	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2397
2398config ARCH_ENABLE_MEMORY_HOTPLUG
2399	def_bool y
2400	depends on X86_64 || (X86_32 && HIGHMEM)
2401
2402config ARCH_ENABLE_MEMORY_HOTREMOVE
2403	def_bool y
2404	depends on MEMORY_HOTPLUG
2405
2406config USE_PERCPU_NUMA_NODE_ID
2407	def_bool y
2408	depends on NUMA
2409
2410config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2411	def_bool y
2412	depends on X86_64 || X86_PAE
2413
2414config ARCH_ENABLE_HUGEPAGE_MIGRATION
2415	def_bool y
2416	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2417
2418config ARCH_ENABLE_THP_MIGRATION
2419	def_bool y
2420	depends on X86_64 && TRANSPARENT_HUGEPAGE
2421
2422menu "Power management and ACPI options"
2423
2424config ARCH_HIBERNATION_HEADER
2425	def_bool y
2426	depends on HIBERNATION
2427
2428source "kernel/power/Kconfig"
2429
2430source "drivers/acpi/Kconfig"
2431
2432source "drivers/sfi/Kconfig"
2433
2434config X86_APM_BOOT
2435	def_bool y
2436	depends on APM
2437
2438menuconfig APM
2439	tristate "APM (Advanced Power Management) BIOS support"
2440	depends on X86_32 && PM_SLEEP
2441	---help---
2442	  APM is a BIOS specification for saving power using several different
2443	  techniques. This is mostly useful for battery powered laptops with
2444	  APM compliant BIOSes. If you say Y here, the system time will be
2445	  reset after a RESUME operation, the /proc/apm device will provide
2446	  battery status information, and user-space programs will receive
2447	  notification of APM "events" (e.g. battery status change).
2448
2449	  If you select "Y" here, you can disable actual use of the APM
2450	  BIOS by passing the "apm=off" option to the kernel at boot time.
2451
2452	  Note that the APM support is almost completely disabled for
2453	  machines with more than one CPU.
2454
2455	  In order to use APM, you will need supporting software. For location
2456	  and more information, read <file:Documentation/power/apm-acpi.txt>
2457	  and the Battery Powered Linux mini-HOWTO, available from
2458	  <http://www.tldp.org/docs.html#howto>.
2459
2460	  This driver does not spin down disk drives (see the hdparm(8)
2461	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2462	  VESA-compliant "green" monitors.
2463
2464	  This driver does not support the TI 4000M TravelMate and the ACER
2465	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2466	  desktop machines also don't have compliant BIOSes, and this driver
2467	  may cause those machines to panic during the boot phase.
2468
2469	  Generally, if you don't have a battery in your machine, there isn't
2470	  much point in using this driver and you should say N. If you get
2471	  random kernel OOPSes or reboots that don't seem to be related to
2472	  anything, try disabling/enabling this option (or disabling/enabling
2473	  APM in your BIOS).
2474
2475	  Some other things you should try when experiencing seemingly random,
2476	  "weird" problems:
2477
2478	  1) make sure that you have enough swap space and that it is
2479	  enabled.
2480	  2) pass the "no-hlt" option to the kernel
2481	  3) switch on floating point emulation in the kernel and pass
2482	  the "no387" option to the kernel
2483	  4) pass the "floppy=nodma" option to the kernel
2484	  5) pass the "mem=4M" option to the kernel (thereby disabling
2485	  all but the first 4 MB of RAM)
2486	  6) make sure that the CPU is not over clocked.
2487	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2488	  8) disable the cache from your BIOS settings
2489	  9) install a fan for the video card or exchange video RAM
2490	  10) install a better fan for the CPU
2491	  11) exchange RAM chips
2492	  12) exchange the motherboard.
2493
2494	  To compile this driver as a module, choose M here: the
2495	  module will be called apm.
2496
2497if APM
2498
2499config APM_IGNORE_USER_SUSPEND
2500	bool "Ignore USER SUSPEND"
2501	---help---
2502	  This option will ignore USER SUSPEND requests. On machines with a
2503	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2504	  series notebooks, it is necessary to say Y because of a BIOS bug.
2505
2506config APM_DO_ENABLE
2507	bool "Enable PM at boot time"
2508	---help---
2509	  Enable APM features at boot time. From page 36 of the APM BIOS
2510	  specification: "When disabled, the APM BIOS does not automatically
2511	  power manage devices, enter the Standby State, enter the Suspend
2512	  State, or take power saving steps in response to CPU Idle calls."
2513	  This driver will make CPU Idle calls when Linux is idle (unless this
2514	  feature is turned off -- see "Do CPU IDLE calls", below). This
2515	  should always save battery power, but more complicated APM features
2516	  will be dependent on your BIOS implementation. You may need to turn
2517	  this option off if your computer hangs at boot time when using APM
2518	  support, or if it beeps continuously instead of suspending. Turn
2519	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2520	  T400CDT. This is off by default since most machines do fine without
2521	  this feature.
2522
2523config APM_CPU_IDLE
2524	depends on CPU_IDLE
2525	bool "Make CPU Idle calls when idle"
2526	---help---
2527	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2528	  On some machines, this can activate improved power savings, such as
2529	  a slowed CPU clock rate, when the machine is idle. These idle calls
2530	  are made after the idle loop has run for some length of time (e.g.,
2531	  333 mS). On some machines, this will cause a hang at boot time or
2532	  whenever the CPU becomes idle. (On machines with more than one CPU,
2533	  this option does nothing.)
2534
2535config APM_DISPLAY_BLANK
2536	bool "Enable console blanking using APM"
2537	---help---
2538	  Enable console blanking using the APM. Some laptops can use this to
2539	  turn off the LCD backlight when the screen blanker of the Linux
2540	  virtual console blanks the screen. Note that this is only used by
2541	  the virtual console screen blanker, and won't turn off the backlight
2542	  when using the X Window system. This also doesn't have anything to
2543	  do with your VESA-compliant power-saving monitor. Further, this
2544	  option doesn't work for all laptops -- it might not turn off your
2545	  backlight at all, or it might print a lot of errors to the console,
2546	  especially if you are using gpm.
2547
2548config APM_ALLOW_INTS
2549	bool "Allow interrupts during APM BIOS calls"
2550	---help---
2551	  Normally we disable external interrupts while we are making calls to
2552	  the APM BIOS as a measure to lessen the effects of a badly behaving
2553	  BIOS implementation.  The BIOS should reenable interrupts if it
2554	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2555	  many of the newer IBM Thinkpads.  If you experience hangs when you
2556	  suspend, try setting this to Y.  Otherwise, say N.
2557
2558endif # APM
2559
2560source "drivers/cpufreq/Kconfig"
2561
2562source "drivers/cpuidle/Kconfig"
2563
2564source "drivers/idle/Kconfig"
2565
2566endmenu
2567
2568
2569menu "Bus options (PCI etc.)"
2570
2571config PCI
2572	bool "PCI support"
2573	default y
2574	---help---
2575	  Find out whether you have a PCI motherboard. PCI is the name of a
2576	  bus system, i.e. the way the CPU talks to the other stuff inside
2577	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2578	  VESA. If you have PCI, say Y, otherwise N.
2579
2580choice
2581	prompt "PCI access mode"
2582	depends on X86_32 && PCI
2583	default PCI_GOANY
2584	---help---
2585	  On PCI systems, the BIOS can be used to detect the PCI devices and
2586	  determine their configuration. However, some old PCI motherboards
2587	  have BIOS bugs and may crash if this is done. Also, some embedded
2588	  PCI-based systems don't have any BIOS at all. Linux can also try to
2589	  detect the PCI hardware directly without using the BIOS.
2590
2591	  With this option, you can specify how Linux should detect the
2592	  PCI devices. If you choose "BIOS", the BIOS will be used,
2593	  if you choose "Direct", the BIOS won't be used, and if you
2594	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2595	  If you choose "Any", the kernel will try MMCONFIG, then the
2596	  direct access method and falls back to the BIOS if that doesn't
2597	  work. If unsure, go with the default, which is "Any".
2598
2599config PCI_GOBIOS
2600	bool "BIOS"
2601
2602config PCI_GOMMCONFIG
2603	bool "MMConfig"
2604
2605config PCI_GODIRECT
2606	bool "Direct"
2607
2608config PCI_GOOLPC
2609	bool "OLPC XO-1"
2610	depends on OLPC
2611
2612config PCI_GOANY
2613	bool "Any"
2614
2615endchoice
2616
2617config PCI_BIOS
2618	def_bool y
2619	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2620
2621# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2622config PCI_DIRECT
2623	def_bool y
2624	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2625
2626config PCI_MMCONFIG
2627	bool "Support mmconfig PCI config space access" if X86_64
2628	default y
2629	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2630	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2631
2632config PCI_OLPC
2633	def_bool y
2634	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2635
2636config PCI_XEN
2637	def_bool y
2638	depends on PCI && XEN
2639	select SWIOTLB_XEN
2640
2641config PCI_DOMAINS
2642	def_bool y
2643	depends on PCI
2644
2645config MMCONF_FAM10H
2646	def_bool y
2647	depends on X86_64 && PCI_MMCONFIG && ACPI
2648
2649config PCI_CNB20LE_QUIRK
2650	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2651	depends on PCI
2652	help
2653	  Read the PCI windows out of the CNB20LE host bridge. This allows
2654	  PCI hotplug to work on systems with the CNB20LE chipset which do
2655	  not have ACPI.
2656
2657	  There's no public spec for this chipset, and this functionality
2658	  is known to be incomplete.
2659
2660	  You should say N unless you know you need this.
2661
2662source "drivers/pci/Kconfig"
2663
2664config ISA_BUS
2665	bool "ISA bus support on modern systems" if EXPERT
2666	help
2667	  Expose ISA bus device drivers and options available for selection and
2668	  configuration. Enable this option if your target machine has an ISA
2669	  bus. ISA is an older system, displaced by PCI and newer bus
2670	  architectures -- if your target machine is modern, it probably does
2671	  not have an ISA bus.
2672
2673	  If unsure, say N.
2674
2675# x86_64 have no ISA slots, but can have ISA-style DMA.
2676config ISA_DMA_API
2677	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2678	default y
2679	help
2680	  Enables ISA-style DMA support for devices requiring such controllers.
2681	  If unsure, say Y.
2682
2683if X86_32
2684
2685config ISA
2686	bool "ISA support"
2687	---help---
2688	  Find out whether you have ISA slots on your motherboard.  ISA is the
2689	  name of a bus system, i.e. the way the CPU talks to the other stuff
2690	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2691	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2692	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2693
2694config EISA
2695	bool "EISA support"
2696	depends on ISA
2697	---help---
2698	  The Extended Industry Standard Architecture (EISA) bus was
2699	  developed as an open alternative to the IBM MicroChannel bus.
2700
2701	  The EISA bus provided some of the features of the IBM MicroChannel
2702	  bus while maintaining backward compatibility with cards made for
2703	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2704	  1995 when it was made obsolete by the PCI bus.
2705
2706	  Say Y here if you are building a kernel for an EISA-based machine.
2707
2708	  Otherwise, say N.
2709
2710source "drivers/eisa/Kconfig"
2711
2712config SCx200
2713	tristate "NatSemi SCx200 support"
2714	---help---
2715	  This provides basic support for National Semiconductor's
2716	  (now AMD's) Geode processors.  The driver probes for the
2717	  PCI-IDs of several on-chip devices, so its a good dependency
2718	  for other scx200_* drivers.
2719
2720	  If compiled as a module, the driver is named scx200.
2721
2722config SCx200HR_TIMER
2723	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2724	depends on SCx200
2725	default y
2726	---help---
2727	  This driver provides a clocksource built upon the on-chip
2728	  27MHz high-resolution timer.  Its also a workaround for
2729	  NSC Geode SC-1100's buggy TSC, which loses time when the
2730	  processor goes idle (as is done by the scheduler).  The
2731	  other workaround is idle=poll boot option.
2732
2733config OLPC
2734	bool "One Laptop Per Child support"
2735	depends on !X86_PAE
2736	select GPIOLIB
2737	select OF
2738	select OF_PROMTREE
2739	select IRQ_DOMAIN
2740	---help---
2741	  Add support for detecting the unique features of the OLPC
2742	  XO hardware.
2743
2744config OLPC_XO1_PM
2745	bool "OLPC XO-1 Power Management"
2746	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2747	---help---
2748	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2749
2750config OLPC_XO1_RTC
2751	bool "OLPC XO-1 Real Time Clock"
2752	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2753	---help---
2754	  Add support for the XO-1 real time clock, which can be used as a
2755	  programmable wakeup source.
2756
2757config OLPC_XO1_SCI
2758	bool "OLPC XO-1 SCI extras"
2759	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2760	depends on INPUT=y
2761	select POWER_SUPPLY
2762	---help---
2763	  Add support for SCI-based features of the OLPC XO-1 laptop:
2764	   - EC-driven system wakeups
2765	   - Power button
2766	   - Ebook switch
2767	   - Lid switch
2768	   - AC adapter status updates
2769	   - Battery status updates
2770
2771config OLPC_XO15_SCI
2772	bool "OLPC XO-1.5 SCI extras"
2773	depends on OLPC && ACPI
2774	select POWER_SUPPLY
2775	---help---
2776	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2777	   - EC-driven system wakeups
2778	   - AC adapter status updates
2779	   - Battery status updates
2780
2781config ALIX
2782	bool "PCEngines ALIX System Support (LED setup)"
2783	select GPIOLIB
2784	---help---
2785	  This option enables system support for the PCEngines ALIX.
2786	  At present this just sets up LEDs for GPIO control on
2787	  ALIX2/3/6 boards.  However, other system specific setup should
2788	  get added here.
2789
2790	  Note: You must still enable the drivers for GPIO and LED support
2791	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2792
2793	  Note: You have to set alix.force=1 for boards with Award BIOS.
2794
2795config NET5501
2796	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2797	select GPIOLIB
2798	---help---
2799	  This option enables system support for the Soekris Engineering net5501.
2800
2801config GEOS
2802	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2803	select GPIOLIB
2804	depends on DMI
2805	---help---
2806	  This option enables system support for the Traverse Technologies GEOS.
2807
2808config TS5500
2809	bool "Technologic Systems TS-5500 platform support"
2810	depends on MELAN
2811	select CHECK_SIGNATURE
2812	select NEW_LEDS
2813	select LEDS_CLASS
2814	---help---
2815	  This option enables system support for the Technologic Systems TS-5500.
2816
2817endif # X86_32
2818
2819config AMD_NB
2820	def_bool y
2821	depends on CPU_SUP_AMD && PCI
2822
2823source "drivers/pcmcia/Kconfig"
2824
2825config RAPIDIO
2826	tristate "RapidIO support"
2827	depends on PCI
2828	help
2829	  If enabled this option will include drivers and the core
2830	  infrastructure code to support RapidIO interconnect devices.
2831
2832source "drivers/rapidio/Kconfig"
2833
2834config X86_SYSFB
2835	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2836	help
2837	  Firmwares often provide initial graphics framebuffers so the BIOS,
2838	  bootloader or kernel can show basic video-output during boot for
2839	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2840	  Extensions and EFI-framebuffers for this, which are mostly limited
2841	  to x86.
2842	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2843	  framebuffers so the new generic system-framebuffer drivers can be
2844	  used on x86. If the framebuffer is not compatible with the generic
2845	  modes, it is advertised as fallback platform framebuffer so legacy
2846	  drivers like efifb, vesafb and uvesafb can pick it up.
2847	  If this option is not selected, all system framebuffers are always
2848	  marked as fallback platform framebuffers as usual.
2849
2850	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2851	  not be able to pick up generic system framebuffers if this option
2852	  is selected. You are highly encouraged to enable simplefb as
2853	  replacement if you select this option. simplefb can correctly deal
2854	  with generic system framebuffers. But you should still keep vesafb
2855	  and others enabled as fallback if a system framebuffer is
2856	  incompatible with simplefb.
2857
2858	  If unsure, say Y.
2859
2860endmenu
2861
2862
2863menu "Binary Emulations"
2864
2865config IA32_EMULATION
2866	bool "IA32 Emulation"
2867	depends on X86_64
2868	select ARCH_WANT_OLD_COMPAT_IPC
2869	select BINFMT_ELF
2870	select COMPAT_BINFMT_ELF
2871	select COMPAT_OLD_SIGACTION
2872	---help---
2873	  Include code to run legacy 32-bit programs under a
2874	  64-bit kernel. You should likely turn this on, unless you're
2875	  100% sure that you don't have any 32-bit programs left.
2876
2877config IA32_AOUT
2878	tristate "IA32 a.out support"
2879	depends on IA32_EMULATION
2880	---help---
2881	  Support old a.out binaries in the 32bit emulation.
2882
2883config X86_X32
2884	bool "x32 ABI for 64-bit mode"
2885	depends on X86_64
2886	---help---
2887	  Include code to run binaries for the x32 native 32-bit ABI
2888	  for 64-bit processors.  An x32 process gets access to the
2889	  full 64-bit register file and wide data path while leaving
2890	  pointers at 32 bits for smaller memory footprint.
2891
2892	  You will need a recent binutils (2.22 or later) with
2893	  elf32_x86_64 support enabled to compile a kernel with this
2894	  option set.
2895
2896config COMPAT_32
2897	def_bool y
2898	depends on IA32_EMULATION || X86_32
2899	select HAVE_UID16
2900	select OLD_SIGSUSPEND3
2901
2902config COMPAT
2903	def_bool y
2904	depends on IA32_EMULATION || X86_X32
2905
2906if COMPAT
2907config COMPAT_FOR_U64_ALIGNMENT
2908	def_bool y
2909
2910config SYSVIPC_COMPAT
2911	def_bool y
2912	depends on SYSVIPC
2913endif
2914
2915endmenu
2916
2917
2918config HAVE_ATOMIC_IOMAP
2919	def_bool y
2920	depends on X86_32
2921
2922config X86_DEV_DMA_OPS
2923	bool
2924	depends on X86_64 || STA2X11
2925
2926config X86_DMA_REMAP
2927	bool
2928	depends on STA2X11
2929
2930config HAVE_GENERIC_GUP
2931	def_bool y
2932
2933source "drivers/firmware/Kconfig"
2934
2935source "arch/x86/kvm/Kconfig"
2936