xref: /openbmc/linux/arch/x86/Kconfig (revision ebd09753)
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
447	  Without compiler support, at least indirect branches in assembler
448	  code are eliminated. Since this includes the syscall entry path,
449	  it is not entirely pointless.
450
451config INTEL_RDT
452	bool "Intel Resource Director Technology support"
453	depends on X86 && CPU_SUP_INTEL
454	select KERNFS
455	help
456	  Select to enable resource allocation and monitoring which are
457	  sub-features of Intel Resource Director Technology(RDT). More
458	  information about RDT can be found in the Intel x86
459	  Architecture Software Developer Manual.
460
461	  Say N if unsure.
462
463if X86_32
464config X86_BIGSMP
465	bool "Support for big SMP systems with more than 8 CPUs"
466	depends on SMP
467	---help---
468	  This option is needed for the systems that have more than 8 CPUs
469
470config X86_EXTENDED_PLATFORM
471	bool "Support for extended (non-PC) x86 platforms"
472	default y
473	---help---
474	  If you disable this option then the kernel will only support
475	  standard PC platforms. (which covers the vast majority of
476	  systems out there.)
477
478	  If you enable this option then you'll be able to select support
479	  for the following (non-PC) 32 bit x86 platforms:
480		Goldfish (Android emulator)
481		AMD Elan
482		RDC R-321x SoC
483		SGI 320/540 (Visual Workstation)
484		STA2X11-based (e.g. Northville)
485		Moorestown MID devices
486
487	  If you have one of these systems, or if you want to build a
488	  generic distribution kernel, say Y here - otherwise say N.
489endif
490
491if X86_64
492config X86_EXTENDED_PLATFORM
493	bool "Support for extended (non-PC) x86 platforms"
494	default y
495	---help---
496	  If you disable this option then the kernel will only support
497	  standard PC platforms. (which covers the vast majority of
498	  systems out there.)
499
500	  If you enable this option then you'll be able to select support
501	  for the following (non-PC) 64 bit x86 platforms:
502		Numascale NumaChip
503		ScaleMP vSMP
504		SGI Ultraviolet
505
506	  If you have one of these systems, or if you want to build a
507	  generic distribution kernel, say Y here - otherwise say N.
508endif
509# This is an alphabetically sorted list of 64 bit extended platforms
510# Please maintain the alphabetic order if and when there are additions
511config X86_NUMACHIP
512	bool "Numascale NumaChip"
513	depends on X86_64
514	depends on X86_EXTENDED_PLATFORM
515	depends on NUMA
516	depends on SMP
517	depends on X86_X2APIC
518	depends on PCI_MMCONFIG
519	---help---
520	  Adds support for Numascale NumaChip large-SMP systems. Needed to
521	  enable more than ~168 cores.
522	  If you don't have one of these, you should say N here.
523
524config X86_VSMP
525	bool "ScaleMP vSMP"
526	select HYPERVISOR_GUEST
527	select PARAVIRT
528	select PARAVIRT_XXL
529	depends on X86_64 && PCI
530	depends on X86_EXTENDED_PLATFORM
531	depends on SMP
532	---help---
533	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
534	  supposed to run on these EM64T-based machines.  Only choose this option
535	  if you have one of these machines.
536
537config X86_UV
538	bool "SGI Ultraviolet"
539	depends on X86_64
540	depends on X86_EXTENDED_PLATFORM
541	depends on NUMA
542	depends on EFI
543	depends on X86_X2APIC
544	depends on PCI
545	---help---
546	  This option is needed in order to support SGI Ultraviolet systems.
547	  If you don't have one of these, you should say N here.
548
549# Following is an alphabetically sorted list of 32 bit extended platforms
550# Please maintain the alphabetic order if and when there are additions
551
552config X86_GOLDFISH
553       bool "Goldfish (Virtual Platform)"
554       depends on X86_EXTENDED_PLATFORM
555       ---help---
556	 Enable support for the Goldfish virtual platform used primarily
557	 for Android development. Unless you are building for the Android
558	 Goldfish emulator say N here.
559
560config X86_INTEL_CE
561	bool "CE4100 TV platform"
562	depends on PCI
563	depends on PCI_GODIRECT
564	depends on X86_IO_APIC
565	depends on X86_32
566	depends on X86_EXTENDED_PLATFORM
567	select X86_REBOOTFIXUPS
568	select OF
569	select OF_EARLY_FLATTREE
570	---help---
571	  Select for the Intel CE media processor (CE4100) SOC.
572	  This option compiles in support for the CE4100 SOC for settop
573	  boxes and media devices.
574
575config X86_INTEL_MID
576	bool "Intel MID platform support"
577	depends on X86_EXTENDED_PLATFORM
578	depends on X86_PLATFORM_DEVICES
579	depends on PCI
580	depends on X86_64 || (PCI_GOANY && X86_32)
581	depends on X86_IO_APIC
582	select SFI
583	select I2C
584	select DW_APB_TIMER
585	select APB_TIMER
586	select INTEL_SCU_IPC
587	select MFD_INTEL_MSIC
588	---help---
589	  Select to build a kernel capable of supporting Intel MID (Mobile
590	  Internet Device) platform systems which do not have the PCI legacy
591	  interfaces. If you are building for a PC class system say N here.
592
593	  Intel MID platforms are based on an Intel processor and chipset which
594	  consume less power than most of the x86 derivatives.
595
596config X86_INTEL_QUARK
597	bool "Intel Quark platform support"
598	depends on X86_32
599	depends on X86_EXTENDED_PLATFORM
600	depends on X86_PLATFORM_DEVICES
601	depends on X86_TSC
602	depends on PCI
603	depends on PCI_GOANY
604	depends on X86_IO_APIC
605	select IOSF_MBI
606	select INTEL_IMR
607	select COMMON_CLK
608	---help---
609	  Select to include support for Quark X1000 SoC.
610	  Say Y here if you have a Quark based system such as the Arduino
611	  compatible Intel Galileo.
612
613config X86_INTEL_LPSS
614	bool "Intel Low Power Subsystem Support"
615	depends on X86 && ACPI
616	select COMMON_CLK
617	select PINCTRL
618	select IOSF_MBI
619	---help---
620	  Select to build support for Intel Low Power Subsystem such as
621	  found on Intel Lynxpoint PCH. Selecting this option enables
622	  things like clock tree (common clock framework) and pincontrol
623	  which are needed by the LPSS peripheral drivers.
624
625config X86_AMD_PLATFORM_DEVICE
626	bool "AMD ACPI2Platform devices support"
627	depends on ACPI
628	select COMMON_CLK
629	select PINCTRL
630	---help---
631	  Select to interpret AMD specific ACPI device to platform device
632	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
633	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
634	  implemented under PINCTRL subsystem.
635
636config IOSF_MBI
637	tristate "Intel SoC IOSF Sideband support for SoC platforms"
638	depends on PCI
639	---help---
640	  This option enables sideband register access support for Intel SoC
641	  platforms. On these platforms the IOSF sideband is used in lieu of
642	  MSR's for some register accesses, mostly but not limited to thermal
643	  and power. Drivers may query the availability of this device to
644	  determine if they need the sideband in order to work on these
645	  platforms. The sideband is available on the following SoC products.
646	  This list is not meant to be exclusive.
647	   - BayTrail
648	   - Braswell
649	   - Quark
650
651	  You should say Y if you are running a kernel on one of these SoC's.
652
653config IOSF_MBI_DEBUG
654	bool "Enable IOSF sideband access through debugfs"
655	depends on IOSF_MBI && DEBUG_FS
656	---help---
657	  Select this option to expose the IOSF sideband access registers (MCR,
658	  MDR, MCRX) through debugfs to write and read register information from
659	  different units on the SoC. This is most useful for obtaining device
660	  state information for debug and analysis. As this is a general access
661	  mechanism, users of this option would have specific knowledge of the
662	  device they want to access.
663
664	  If you don't require the option or are in doubt, say N.
665
666config X86_RDC321X
667	bool "RDC R-321x SoC"
668	depends on X86_32
669	depends on X86_EXTENDED_PLATFORM
670	select M486
671	select X86_REBOOTFIXUPS
672	---help---
673	  This option is needed for RDC R-321x system-on-chip, also known
674	  as R-8610-(G).
675	  If you don't have one of these chips, you should say N here.
676
677config X86_32_NON_STANDARD
678	bool "Support non-standard 32-bit SMP architectures"
679	depends on X86_32 && SMP
680	depends on X86_EXTENDED_PLATFORM
681	---help---
682	  This option compiles in the bigsmp and STA2X11 default
683	  subarchitectures.  It is intended for a generic binary
684	  kernel. If you select them all, kernel will probe it one by
685	  one and will fallback to default.
686
687# Alphabetically sorted list of Non standard 32 bit platforms
688
689config X86_SUPPORTS_MEMORY_FAILURE
690	def_bool y
691	# MCE code calls memory_failure():
692	depends on X86_MCE
693	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
694	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
695	depends on X86_64 || !SPARSEMEM
696	select ARCH_SUPPORTS_MEMORY_FAILURE
697
698config STA2X11
699	bool "STA2X11 Companion Chip Support"
700	depends on X86_32_NON_STANDARD && PCI
701	select ARCH_HAS_PHYS_TO_DMA
702	select X86_DEV_DMA_OPS
703	select X86_DMA_REMAP
704	select SWIOTLB
705	select MFD_STA2X11
706	select GPIOLIB
707	---help---
708	  This adds support for boards based on the STA2X11 IO-Hub,
709	  a.k.a. "ConneXt". The chip is used in place of the standard
710	  PC chipset, so all "standard" peripherals are missing. If this
711	  option is selected the kernel will still be able to boot on
712	  standard PC machines.
713
714config X86_32_IRIS
715	tristate "Eurobraille/Iris poweroff module"
716	depends on X86_32
717	---help---
718	  The Iris machines from EuroBraille do not have APM or ACPI support
719	  to shut themselves down properly.  A special I/O sequence is
720	  needed to do so, which is what this module does at
721	  kernel shutdown.
722
723	  This is only for Iris machines from EuroBraille.
724
725	  If unused, say N.
726
727config SCHED_OMIT_FRAME_POINTER
728	def_bool y
729	prompt "Single-depth WCHAN output"
730	depends on X86
731	---help---
732	  Calculate simpler /proc/<PID>/wchan values. If this option
733	  is disabled then wchan values will recurse back to the
734	  caller function. This provides more accurate wchan values,
735	  at the expense of slightly more scheduling overhead.
736
737	  If in doubt, say "Y".
738
739menuconfig HYPERVISOR_GUEST
740	bool "Linux guest support"
741	---help---
742	  Say Y here to enable options for running Linux under various hyper-
743	  visors. This option enables basic hypervisor detection and platform
744	  setup.
745
746	  If you say N, all options in this submenu will be skipped and
747	  disabled, and Linux guest support won't be built in.
748
749if HYPERVISOR_GUEST
750
751config PARAVIRT
752	bool "Enable paravirtualization code"
753	---help---
754	  This changes the kernel so it can modify itself when it is run
755	  under a hypervisor, potentially improving performance significantly
756	  over full virtualization.  However, when run without a hypervisor
757	  the kernel is theoretically slower and slightly larger.
758
759config PARAVIRT_XXL
760	bool
761
762config PARAVIRT_DEBUG
763	bool "paravirt-ops debugging"
764	depends on PARAVIRT && DEBUG_KERNEL
765	---help---
766	  Enable to debug paravirt_ops internals.  Specifically, BUG if
767	  a paravirt_op is missing when it is called.
768
769config PARAVIRT_SPINLOCKS
770	bool "Paravirtualization layer for spinlocks"
771	depends on PARAVIRT && SMP
772	---help---
773	  Paravirtualized spinlocks allow a pvops backend to replace the
774	  spinlock implementation with something virtualization-friendly
775	  (for example, block the virtual CPU rather than spinning).
776
777	  It has a minimal impact on native kernels and gives a nice performance
778	  benefit on paravirtualized KVM / Xen kernels.
779
780	  If you are unsure how to answer this question, answer Y.
781
782config QUEUED_LOCK_STAT
783	bool "Paravirt queued spinlock statistics"
784	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
785	---help---
786	  Enable the collection of statistical data on the slowpath
787	  behavior of paravirtualized queued spinlocks and report
788	  them on debugfs.
789
790source "arch/x86/xen/Kconfig"
791
792config KVM_GUEST
793	bool "KVM Guest support (including kvmclock)"
794	depends on PARAVIRT
795	select PARAVIRT_CLOCK
796	default y
797	---help---
798	  This option enables various optimizations for running under the KVM
799	  hypervisor. It includes a paravirtualized clock, so that instead
800	  of relying on a PIT (or probably other) emulation by the
801	  underlying device model, the host provides the guest with
802	  timing infrastructure such as time of day, and system time
803
804config KVM_DEBUG_FS
805	bool "Enable debug information for KVM Guests in debugfs"
806	depends on KVM_GUEST && DEBUG_FS
807	---help---
808	  This option enables collection of various statistics for KVM guest.
809	  Statistics are displayed in debugfs filesystem. Enabling this option
810	  may incur significant overhead.
811
812config PARAVIRT_TIME_ACCOUNTING
813	bool "Paravirtual steal time accounting"
814	depends on PARAVIRT
815	---help---
816	  Select this option to enable fine granularity task steal time
817	  accounting. Time spent executing other tasks in parallel with
818	  the current vCPU is discounted from the vCPU power. To account for
819	  that, there can be a small performance impact.
820
821	  If in doubt, say N here.
822
823config PARAVIRT_CLOCK
824	bool
825
826config JAILHOUSE_GUEST
827	bool "Jailhouse non-root cell support"
828	depends on X86_64 && PCI
829	select X86_PM_TIMER
830	---help---
831	  This option allows to run Linux as guest in a Jailhouse non-root
832	  cell. You can leave this option disabled if you only want to start
833	  Jailhouse and run Linux afterwards in the root cell.
834
835endif #HYPERVISOR_GUEST
836
837source "arch/x86/Kconfig.cpu"
838
839config HPET_TIMER
840	def_bool X86_64
841	prompt "HPET Timer Support" if X86_32
842	---help---
843	  Use the IA-PC HPET (High Precision Event Timer) to manage
844	  time in preference to the PIT and RTC, if a HPET is
845	  present.
846	  HPET is the next generation timer replacing legacy 8254s.
847	  The HPET provides a stable time base on SMP
848	  systems, unlike the TSC, but it is more expensive to access,
849	  as it is off-chip.  The interface used is documented
850	  in the HPET spec, revision 1.
851
852	  You can safely choose Y here.  However, HPET will only be
853	  activated if the platform and the BIOS support this feature.
854	  Otherwise the 8254 will be used for timing services.
855
856	  Choose N to continue using the legacy 8254 timer.
857
858config HPET_EMULATE_RTC
859	def_bool y
860	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
861
862config APB_TIMER
863       def_bool y if X86_INTEL_MID
864       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
865       select DW_APB_TIMER
866       depends on X86_INTEL_MID && SFI
867       help
868         APB timer is the replacement for 8254, HPET on X86 MID platforms.
869         The APBT provides a stable time base on SMP
870         systems, unlike the TSC, but it is more expensive to access,
871         as it is off-chip. APB timers are always running regardless of CPU
872         C states, they are used as per CPU clockevent device when possible.
873
874# Mark as expert because too many people got it wrong.
875# The code disables itself when not needed.
876config DMI
877	default y
878	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
879	bool "Enable DMI scanning" if EXPERT
880	---help---
881	  Enabled scanning of DMI to identify machine quirks. Say Y
882	  here unless you have verified that your setup is not
883	  affected by entries in the DMI blacklist. Required by PNP
884	  BIOS code.
885
886config GART_IOMMU
887	bool "Old AMD GART IOMMU support"
888	select IOMMU_HELPER
889	select SWIOTLB
890	depends on X86_64 && PCI && AMD_NB
891	---help---
892	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
893	  GART based hardware IOMMUs.
894
895	  The GART supports full DMA access for devices with 32-bit access
896	  limitations, on systems with more than 3 GB. This is usually needed
897	  for USB, sound, many IDE/SATA chipsets and some other devices.
898
899	  Newer systems typically have a modern AMD IOMMU, supported via
900	  the CONFIG_AMD_IOMMU=y config option.
901
902	  In normal configurations this driver is only active when needed:
903	  there's more than 3 GB of memory and the system contains a
904	  32-bit limited device.
905
906	  If unsure, say Y.
907
908config CALGARY_IOMMU
909	bool "IBM Calgary IOMMU support"
910	select IOMMU_HELPER
911	select SWIOTLB
912	depends on X86_64 && PCI
913	---help---
914	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
915	  systems. Needed to run systems with more than 3GB of memory
916	  properly with 32-bit PCI devices that do not support DAC
917	  (Double Address Cycle). Calgary also supports bus level
918	  isolation, where all DMAs pass through the IOMMU.  This
919	  prevents them from going anywhere except their intended
920	  destination. This catches hard-to-find kernel bugs and
921	  mis-behaving drivers and devices that do not use the DMA-API
922	  properly to set up their DMA buffers.  The IOMMU can be
923	  turned off at boot time with the iommu=off parameter.
924	  Normally the kernel will make the right choice by itself.
925	  If unsure, say Y.
926
927config CALGARY_IOMMU_ENABLED_BY_DEFAULT
928	def_bool y
929	prompt "Should Calgary be enabled by default?"
930	depends on CALGARY_IOMMU
931	---help---
932	  Should Calgary be enabled by default? if you choose 'y', Calgary
933	  will be used (if it exists). If you choose 'n', Calgary will not be
934	  used even if it exists. If you choose 'n' and would like to use
935	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
936	  If unsure, say Y.
937
938config MAXSMP
939	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
940	depends on X86_64 && SMP && DEBUG_KERNEL
941	select CPUMASK_OFFSTACK
942	---help---
943	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
944	  If unsure, say N.
945
946#
947# The maximum number of CPUs supported:
948#
949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
950# and which can be configured interactively in the
951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
952#
953# The ranges are different on 32-bit and 64-bit kernels, depending on
954# hardware capabilities and scalability features of the kernel.
955#
956# ( If MAXSMP is enabled we just use the highest possible value and disable
957#   interactive configuration. )
958#
959
960config NR_CPUS_RANGE_BEGIN
961	int
962	default NR_CPUS_RANGE_END if MAXSMP
963	default    1 if !SMP
964	default    2
965
966config NR_CPUS_RANGE_END
967	int
968	depends on X86_32
969	default   64 if  SMP &&  X86_BIGSMP
970	default    8 if  SMP && !X86_BIGSMP
971	default    1 if !SMP
972
973config NR_CPUS_RANGE_END
974	int
975	depends on X86_64
976	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
977	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
978	default    1 if !SMP
979
980config NR_CPUS_DEFAULT
981	int
982	depends on X86_32
983	default   32 if  X86_BIGSMP
984	default    8 if  SMP
985	default    1 if !SMP
986
987config NR_CPUS_DEFAULT
988	int
989	depends on X86_64
990	default 8192 if  MAXSMP
991	default   64 if  SMP
992	default    1 if !SMP
993
994config NR_CPUS
995	int "Maximum number of CPUs" if SMP && !MAXSMP
996	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
997	default NR_CPUS_DEFAULT
998	---help---
999	  This allows you to specify the maximum number of CPUs which this
1000	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1001	  supported value is 8192, otherwise the maximum value is 512.  The
1002	  minimum value which makes sense is 2.
1003
1004	  This is purely to save memory: each supported CPU adds about 8KB
1005	  to the kernel image.
1006
1007config SCHED_SMT
1008	bool "SMT (Hyperthreading) scheduler support"
1009	depends on SMP
1010	---help---
1011	  SMT scheduler support improves the CPU scheduler's decision making
1012	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1013	  cost of slightly increased overhead in some places. If unsure say
1014	  N here.
1015
1016config SCHED_MC
1017	def_bool y
1018	prompt "Multi-core scheduler support"
1019	depends on SMP
1020	---help---
1021	  Multi-core scheduler support improves the CPU scheduler's decision
1022	  making when dealing with multi-core CPU chips at a cost of slightly
1023	  increased overhead in some places. If unsure say N here.
1024
1025config SCHED_MC_PRIO
1026	bool "CPU core priorities scheduler support"
1027	depends on SCHED_MC && CPU_SUP_INTEL
1028	select X86_INTEL_PSTATE
1029	select CPU_FREQ
1030	default y
1031	---help---
1032	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1033	  core ordering determined at manufacturing time, which allows
1034	  certain cores to reach higher turbo frequencies (when running
1035	  single threaded workloads) than others.
1036
1037	  Enabling this kernel feature teaches the scheduler about
1038	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1039	  scheduler's CPU selection logic accordingly, so that higher
1040	  overall system performance can be achieved.
1041
1042	  This feature will have no effect on CPUs without this feature.
1043
1044	  If unsure say Y here.
1045
1046config UP_LATE_INIT
1047       def_bool y
1048       depends on !SMP && X86_LOCAL_APIC
1049
1050config X86_UP_APIC
1051	bool "Local APIC support on uniprocessors" if !PCI_MSI
1052	default PCI_MSI
1053	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1054	---help---
1055	  A local APIC (Advanced Programmable Interrupt Controller) is an
1056	  integrated interrupt controller in the CPU. If you have a single-CPU
1057	  system which has a processor with a local APIC, you can say Y here to
1058	  enable and use it. If you say Y here even though your machine doesn't
1059	  have a local APIC, then the kernel will still run with no slowdown at
1060	  all. The local APIC supports CPU-generated self-interrupts (timer,
1061	  performance counters), and the NMI watchdog which detects hard
1062	  lockups.
1063
1064config X86_UP_IOAPIC
1065	bool "IO-APIC support on uniprocessors"
1066	depends on X86_UP_APIC
1067	---help---
1068	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1069	  SMP-capable replacement for PC-style interrupt controllers. Most
1070	  SMP systems and many recent uniprocessor systems have one.
1071
1072	  If you have a single-CPU system with an IO-APIC, you can say Y here
1073	  to use it. If you say Y here even though your machine doesn't have
1074	  an IO-APIC, then the kernel will still run with no slowdown at all.
1075
1076config X86_LOCAL_APIC
1077	def_bool y
1078	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1079	select IRQ_DOMAIN_HIERARCHY
1080	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1081
1082config X86_IO_APIC
1083	def_bool y
1084	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1085
1086config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1087	bool "Reroute for broken boot IRQs"
1088	depends on X86_IO_APIC
1089	---help---
1090	  This option enables a workaround that fixes a source of
1091	  spurious interrupts. This is recommended when threaded
1092	  interrupt handling is used on systems where the generation of
1093	  superfluous "boot interrupts" cannot be disabled.
1094
1095	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1096	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1097	  kernel does during interrupt handling). On chipsets where this
1098	  boot IRQ generation cannot be disabled, this workaround keeps
1099	  the original IRQ line masked so that only the equivalent "boot
1100	  IRQ" is delivered to the CPUs. The workaround also tells the
1101	  kernel to set up the IRQ handler on the boot IRQ line. In this
1102	  way only one interrupt is delivered to the kernel. Otherwise
1103	  the spurious second interrupt may cause the kernel to bring
1104	  down (vital) interrupt lines.
1105
1106	  Only affects "broken" chipsets. Interrupt sharing may be
1107	  increased on these systems.
1108
1109config X86_MCE
1110	bool "Machine Check / overheating reporting"
1111	select GENERIC_ALLOCATOR
1112	default y
1113	---help---
1114	  Machine Check support allows the processor to notify the
1115	  kernel if it detects a problem (e.g. overheating, data corruption).
1116	  The action the kernel takes depends on the severity of the problem,
1117	  ranging from warning messages to halting the machine.
1118
1119config X86_MCELOG_LEGACY
1120	bool "Support for deprecated /dev/mcelog character device"
1121	depends on X86_MCE
1122	---help---
1123	  Enable support for /dev/mcelog which is needed by the old mcelog
1124	  userspace logging daemon. Consider switching to the new generation
1125	  rasdaemon solution.
1126
1127config X86_MCE_INTEL
1128	def_bool y
1129	prompt "Intel MCE features"
1130	depends on X86_MCE && X86_LOCAL_APIC
1131	---help---
1132	   Additional support for intel specific MCE features such as
1133	   the thermal monitor.
1134
1135config X86_MCE_AMD
1136	def_bool y
1137	prompt "AMD MCE features"
1138	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1139	---help---
1140	   Additional support for AMD specific MCE features such as
1141	   the DRAM Error Threshold.
1142
1143config X86_ANCIENT_MCE
1144	bool "Support for old Pentium 5 / WinChip machine checks"
1145	depends on X86_32 && X86_MCE
1146	---help---
1147	  Include support for machine check handling on old Pentium 5 or WinChip
1148	  systems. These typically need to be enabled explicitly on the command
1149	  line.
1150
1151config X86_MCE_THRESHOLD
1152	depends on X86_MCE_AMD || X86_MCE_INTEL
1153	def_bool y
1154
1155config X86_MCE_INJECT
1156	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1157	tristate "Machine check injector support"
1158	---help---
1159	  Provide support for injecting machine checks for testing purposes.
1160	  If you don't know what a machine check is and you don't do kernel
1161	  QA it is safe to say n.
1162
1163config X86_THERMAL_VECTOR
1164	def_bool y
1165	depends on X86_MCE_INTEL
1166
1167source "arch/x86/events/Kconfig"
1168
1169config X86_LEGACY_VM86
1170	bool "Legacy VM86 support"
1171	depends on X86_32
1172	---help---
1173	  This option allows user programs to put the CPU into V8086
1174	  mode, which is an 80286-era approximation of 16-bit real mode.
1175
1176	  Some very old versions of X and/or vbetool require this option
1177	  for user mode setting.  Similarly, DOSEMU will use it if
1178	  available to accelerate real mode DOS programs.  However, any
1179	  recent version of DOSEMU, X, or vbetool should be fully
1180	  functional even without kernel VM86 support, as they will all
1181	  fall back to software emulation. Nevertheless, if you are using
1182	  a 16-bit DOS program where 16-bit performance matters, vm86
1183	  mode might be faster than emulation and you might want to
1184	  enable this option.
1185
1186	  Note that any app that works on a 64-bit kernel is unlikely to
1187	  need this option, as 64-bit kernels don't, and can't, support
1188	  V8086 mode. This option is also unrelated to 16-bit protected
1189	  mode and is not needed to run most 16-bit programs under Wine.
1190
1191	  Enabling this option increases the complexity of the kernel
1192	  and slows down exception handling a tiny bit.
1193
1194	  If unsure, say N here.
1195
1196config VM86
1197       bool
1198       default X86_LEGACY_VM86
1199
1200config X86_16BIT
1201	bool "Enable support for 16-bit segments" if EXPERT
1202	default y
1203	depends on MODIFY_LDT_SYSCALL
1204	---help---
1205	  This option is required by programs like Wine to run 16-bit
1206	  protected mode legacy code on x86 processors.  Disabling
1207	  this option saves about 300 bytes on i386, or around 6K text
1208	  plus 16K runtime memory on x86-64,
1209
1210config X86_ESPFIX32
1211	def_bool y
1212	depends on X86_16BIT && X86_32
1213
1214config X86_ESPFIX64
1215	def_bool y
1216	depends on X86_16BIT && X86_64
1217
1218config X86_VSYSCALL_EMULATION
1219       bool "Enable vsyscall emulation" if EXPERT
1220       default y
1221       depends on X86_64
1222       ---help---
1223	 This enables emulation of the legacy vsyscall page.  Disabling
1224	 it is roughly equivalent to booting with vsyscall=none, except
1225	 that it will also disable the helpful warning if a program
1226	 tries to use a vsyscall.  With this option set to N, offending
1227	 programs will just segfault, citing addresses of the form
1228	 0xffffffffff600?00.
1229
1230	 This option is required by many programs built before 2013, and
1231	 care should be used even with newer programs if set to N.
1232
1233	 Disabling this option saves about 7K of kernel size and
1234	 possibly 4K of additional runtime pagetable memory.
1235
1236config TOSHIBA
1237	tristate "Toshiba Laptop support"
1238	depends on X86_32
1239	---help---
1240	  This adds a driver to safely access the System Management Mode of
1241	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1242	  not work on models with a Phoenix BIOS. The System Management Mode
1243	  is used to set the BIOS and power saving options on Toshiba portables.
1244
1245	  For information on utilities to make use of this driver see the
1246	  Toshiba Linux utilities web site at:
1247	  <http://www.buzzard.org.uk/toshiba/>.
1248
1249	  Say Y if you intend to run this kernel on a Toshiba portable.
1250	  Say N otherwise.
1251
1252config I8K
1253	tristate "Dell i8k legacy laptop support"
1254	select HWMON
1255	select SENSORS_DELL_SMM
1256	---help---
1257	  This option enables legacy /proc/i8k userspace interface in hwmon
1258	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1259	  temperature and allows controlling fan speeds of Dell laptops via
1260	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1261	  it reports also power and hotkey status. For fan speed control is
1262	  needed userspace package i8kutils.
1263
1264	  Say Y if you intend to run this kernel on old Dell laptops or want to
1265	  use userspace package i8kutils.
1266	  Say N otherwise.
1267
1268config X86_REBOOTFIXUPS
1269	bool "Enable X86 board specific fixups for reboot"
1270	depends on X86_32
1271	---help---
1272	  This enables chipset and/or board specific fixups to be done
1273	  in order to get reboot to work correctly. This is only needed on
1274	  some combinations of hardware and BIOS. The symptom, for which
1275	  this config is intended, is when reboot ends with a stalled/hung
1276	  system.
1277
1278	  Currently, the only fixup is for the Geode machines using
1279	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1280
1281	  Say Y if you want to enable the fixup. Currently, it's safe to
1282	  enable this option even if you don't need it.
1283	  Say N otherwise.
1284
1285config MICROCODE
1286	bool "CPU microcode loading support"
1287	default y
1288	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1289	select FW_LOADER
1290	---help---
1291	  If you say Y here, you will be able to update the microcode on
1292	  Intel and AMD processors. The Intel support is for the IA32 family,
1293	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1294	  AMD support is for families 0x10 and later. You will obviously need
1295	  the actual microcode binary data itself which is not shipped with
1296	  the Linux kernel.
1297
1298	  The preferred method to load microcode from a detached initrd is described
1299	  in Documentation/x86/microcode.txt. For that you need to enable
1300	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1301	  initrd for microcode blobs.
1302
1303	  In addition, you can build the microcode into the kernel. For that you
1304	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1305	  config option.
1306
1307config MICROCODE_INTEL
1308	bool "Intel microcode loading support"
1309	depends on MICROCODE
1310	default MICROCODE
1311	select FW_LOADER
1312	---help---
1313	  This options enables microcode patch loading support for Intel
1314	  processors.
1315
1316	  For the current Intel microcode data package go to
1317	  <https://downloadcenter.intel.com> and search for
1318	  'Linux Processor Microcode Data File'.
1319
1320config MICROCODE_AMD
1321	bool "AMD microcode loading support"
1322	depends on MICROCODE
1323	select FW_LOADER
1324	---help---
1325	  If you select this option, microcode patch loading support for AMD
1326	  processors will be enabled.
1327
1328config MICROCODE_OLD_INTERFACE
1329	def_bool y
1330	depends on MICROCODE
1331
1332config X86_MSR
1333	tristate "/dev/cpu/*/msr - Model-specific register support"
1334	---help---
1335	  This device gives privileged processes access to the x86
1336	  Model-Specific Registers (MSRs).  It is a character device with
1337	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1338	  MSR accesses are directed to a specific CPU on multi-processor
1339	  systems.
1340
1341config X86_CPUID
1342	tristate "/dev/cpu/*/cpuid - CPU information support"
1343	---help---
1344	  This device gives processes access to the x86 CPUID instruction to
1345	  be executed on a specific processor.  It is a character device
1346	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1347	  /dev/cpu/31/cpuid.
1348
1349choice
1350	prompt "High Memory Support"
1351	default HIGHMEM4G
1352	depends on X86_32
1353
1354config NOHIGHMEM
1355	bool "off"
1356	---help---
1357	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1358	  However, the address space of 32-bit x86 processors is only 4
1359	  Gigabytes large. That means that, if you have a large amount of
1360	  physical memory, not all of it can be "permanently mapped" by the
1361	  kernel. The physical memory that's not permanently mapped is called
1362	  "high memory".
1363
1364	  If you are compiling a kernel which will never run on a machine with
1365	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1366	  choice and suitable for most users). This will result in a "3GB/1GB"
1367	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1368	  space and the remaining part of the 4GB virtual memory space is used
1369	  by the kernel to permanently map as much physical memory as
1370	  possible.
1371
1372	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1373	  answer "4GB" here.
1374
1375	  If more than 4 Gigabytes is used then answer "64GB" here. This
1376	  selection turns Intel PAE (Physical Address Extension) mode on.
1377	  PAE implements 3-level paging on IA32 processors. PAE is fully
1378	  supported by Linux, PAE mode is implemented on all recent Intel
1379	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1380	  then the kernel will not boot on CPUs that don't support PAE!
1381
1382	  The actual amount of total physical memory will either be
1383	  auto detected or can be forced by using a kernel command line option
1384	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1385	  your boot loader (lilo or loadlin) about how to pass options to the
1386	  kernel at boot time.)
1387
1388	  If unsure, say "off".
1389
1390config HIGHMEM4G
1391	bool "4GB"
1392	---help---
1393	  Select this if you have a 32-bit processor and between 1 and 4
1394	  gigabytes of physical RAM.
1395
1396config HIGHMEM64G
1397	bool "64GB"
1398	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1399	select X86_PAE
1400	---help---
1401	  Select this if you have a 32-bit processor and more than 4
1402	  gigabytes of physical RAM.
1403
1404endchoice
1405
1406choice
1407	prompt "Memory split" if EXPERT
1408	default VMSPLIT_3G
1409	depends on X86_32
1410	---help---
1411	  Select the desired split between kernel and user memory.
1412
1413	  If the address range available to the kernel is less than the
1414	  physical memory installed, the remaining memory will be available
1415	  as "high memory". Accessing high memory is a little more costly
1416	  than low memory, as it needs to be mapped into the kernel first.
1417	  Note that increasing the kernel address space limits the range
1418	  available to user programs, making the address space there
1419	  tighter.  Selecting anything other than the default 3G/1G split
1420	  will also likely make your kernel incompatible with binary-only
1421	  kernel modules.
1422
1423	  If you are not absolutely sure what you are doing, leave this
1424	  option alone!
1425
1426	config VMSPLIT_3G
1427		bool "3G/1G user/kernel split"
1428	config VMSPLIT_3G_OPT
1429		depends on !X86_PAE
1430		bool "3G/1G user/kernel split (for full 1G low memory)"
1431	config VMSPLIT_2G
1432		bool "2G/2G user/kernel split"
1433	config VMSPLIT_2G_OPT
1434		depends on !X86_PAE
1435		bool "2G/2G user/kernel split (for full 2G low memory)"
1436	config VMSPLIT_1G
1437		bool "1G/3G user/kernel split"
1438endchoice
1439
1440config PAGE_OFFSET
1441	hex
1442	default 0xB0000000 if VMSPLIT_3G_OPT
1443	default 0x80000000 if VMSPLIT_2G
1444	default 0x78000000 if VMSPLIT_2G_OPT
1445	default 0x40000000 if VMSPLIT_1G
1446	default 0xC0000000
1447	depends on X86_32
1448
1449config HIGHMEM
1450	def_bool y
1451	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1452
1453config X86_PAE
1454	bool "PAE (Physical Address Extension) Support"
1455	depends on X86_32 && !HIGHMEM4G
1456	select PHYS_ADDR_T_64BIT
1457	select SWIOTLB
1458	---help---
1459	  PAE is required for NX support, and furthermore enables
1460	  larger swapspace support for non-overcommit purposes. It
1461	  has the cost of more pagetable lookup overhead, and also
1462	  consumes more pagetable space per process.
1463
1464config X86_5LEVEL
1465	bool "Enable 5-level page tables support"
1466	select DYNAMIC_MEMORY_LAYOUT
1467	select SPARSEMEM_VMEMMAP
1468	depends on X86_64
1469	---help---
1470	  5-level paging enables access to larger address space:
1471	  upto 128 PiB of virtual address space and 4 PiB of
1472	  physical address space.
1473
1474	  It will be supported by future Intel CPUs.
1475
1476	  A kernel with the option enabled can be booted on machines that
1477	  support 4- or 5-level paging.
1478
1479	  See Documentation/x86/x86_64/5level-paging.txt for more
1480	  information.
1481
1482	  Say N if unsure.
1483
1484config X86_DIRECT_GBPAGES
1485	def_bool y
1486	depends on X86_64 && !DEBUG_PAGEALLOC
1487	---help---
1488	  Certain kernel features effectively disable kernel
1489	  linear 1 GB mappings (even if the CPU otherwise
1490	  supports them), so don't confuse the user by printing
1491	  that we have them enabled.
1492
1493config X86_CPA_STATISTICS
1494	bool "Enable statistic for Change Page Attribute"
1495	depends on DEBUG_FS
1496	---help---
1497	  Expose statistics about the Change Page Attribute mechanims, which
1498	  helps to determine the effectivness of preserving large and huge
1499	  page mappings when mapping protections are changed.
1500
1501config ARCH_HAS_MEM_ENCRYPT
1502	def_bool y
1503
1504config AMD_MEM_ENCRYPT
1505	bool "AMD Secure Memory Encryption (SME) support"
1506	depends on X86_64 && CPU_SUP_AMD
1507	select DYNAMIC_PHYSICAL_MASK
1508	---help---
1509	  Say yes to enable support for the encryption of system memory.
1510	  This requires an AMD processor that supports Secure Memory
1511	  Encryption (SME).
1512
1513config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1514	bool "Activate AMD Secure Memory Encryption (SME) by default"
1515	default y
1516	depends on AMD_MEM_ENCRYPT
1517	---help---
1518	  Say yes to have system memory encrypted by default if running on
1519	  an AMD processor that supports Secure Memory Encryption (SME).
1520
1521	  If set to Y, then the encryption of system memory can be
1522	  deactivated with the mem_encrypt=off command line option.
1523
1524	  If set to N, then the encryption of system memory can be
1525	  activated with the mem_encrypt=on command line option.
1526
1527config ARCH_USE_MEMREMAP_PROT
1528	def_bool y
1529	depends on AMD_MEM_ENCRYPT
1530
1531# Common NUMA Features
1532config NUMA
1533	bool "Numa Memory Allocation and Scheduler Support"
1534	depends on SMP
1535	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1536	default y if X86_BIGSMP
1537	---help---
1538	  Enable NUMA (Non Uniform Memory Access) support.
1539
1540	  The kernel will try to allocate memory used by a CPU on the
1541	  local memory controller of the CPU and add some more
1542	  NUMA awareness to the kernel.
1543
1544	  For 64-bit this is recommended if the system is Intel Core i7
1545	  (or later), AMD Opteron, or EM64T NUMA.
1546
1547	  For 32-bit this is only needed if you boot a 32-bit
1548	  kernel on a 64-bit NUMA platform.
1549
1550	  Otherwise, you should say N.
1551
1552config AMD_NUMA
1553	def_bool y
1554	prompt "Old style AMD Opteron NUMA detection"
1555	depends on X86_64 && NUMA && PCI
1556	---help---
1557	  Enable AMD NUMA node topology detection.  You should say Y here if
1558	  you have a multi processor AMD system. This uses an old method to
1559	  read the NUMA configuration directly from the builtin Northbridge
1560	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1561	  which also takes priority if both are compiled in.
1562
1563config X86_64_ACPI_NUMA
1564	def_bool y
1565	prompt "ACPI NUMA detection"
1566	depends on X86_64 && NUMA && ACPI && PCI
1567	select ACPI_NUMA
1568	---help---
1569	  Enable ACPI SRAT based node topology detection.
1570
1571# Some NUMA nodes have memory ranges that span
1572# other nodes.  Even though a pfn is valid and
1573# between a node's start and end pfns, it may not
1574# reside on that node.  See memmap_init_zone()
1575# for details.
1576config NODES_SPAN_OTHER_NODES
1577	def_bool y
1578	depends on X86_64_ACPI_NUMA
1579
1580config NUMA_EMU
1581	bool "NUMA emulation"
1582	depends on NUMA
1583	---help---
1584	  Enable NUMA emulation. A flat machine will be split
1585	  into virtual nodes when booted with "numa=fake=N", where N is the
1586	  number of nodes. This is only useful for debugging.
1587
1588config NODES_SHIFT
1589	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1590	range 1 10
1591	default "10" if MAXSMP
1592	default "6" if X86_64
1593	default "3"
1594	depends on NEED_MULTIPLE_NODES
1595	---help---
1596	  Specify the maximum number of NUMA Nodes available on the target
1597	  system.  Increases memory reserved to accommodate various tables.
1598
1599config ARCH_HAVE_MEMORY_PRESENT
1600	def_bool y
1601	depends on X86_32 && DISCONTIGMEM
1602
1603config ARCH_FLATMEM_ENABLE
1604	def_bool y
1605	depends on X86_32 && !NUMA
1606
1607config ARCH_DISCONTIGMEM_ENABLE
1608	def_bool y
1609	depends on NUMA && X86_32
1610
1611config ARCH_DISCONTIGMEM_DEFAULT
1612	def_bool y
1613	depends on NUMA && X86_32
1614
1615config ARCH_SPARSEMEM_ENABLE
1616	def_bool y
1617	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1618	select SPARSEMEM_STATIC if X86_32
1619	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1620
1621config ARCH_SPARSEMEM_DEFAULT
1622	def_bool y
1623	depends on X86_64
1624
1625config ARCH_SELECT_MEMORY_MODEL
1626	def_bool y
1627	depends on ARCH_SPARSEMEM_ENABLE
1628
1629config ARCH_MEMORY_PROBE
1630	bool "Enable sysfs memory/probe interface"
1631	depends on X86_64 && MEMORY_HOTPLUG
1632	help
1633	  This option enables a sysfs memory/probe interface for testing.
1634	  See Documentation/memory-hotplug.txt for more information.
1635	  If you are unsure how to answer this question, answer N.
1636
1637config ARCH_PROC_KCORE_TEXT
1638	def_bool y
1639	depends on X86_64 && PROC_KCORE
1640
1641config ILLEGAL_POINTER_VALUE
1642       hex
1643       default 0 if X86_32
1644       default 0xdead000000000000 if X86_64
1645
1646config X86_PMEM_LEGACY_DEVICE
1647	bool
1648
1649config X86_PMEM_LEGACY
1650	tristate "Support non-standard NVDIMMs and ADR protected memory"
1651	depends on PHYS_ADDR_T_64BIT
1652	depends on BLK_DEV
1653	select X86_PMEM_LEGACY_DEVICE
1654	select LIBNVDIMM
1655	help
1656	  Treat memory marked using the non-standard e820 type of 12 as used
1657	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1658	  The kernel will offer these regions to the 'pmem' driver so
1659	  they can be used for persistent storage.
1660
1661	  Say Y if unsure.
1662
1663config HIGHPTE
1664	bool "Allocate 3rd-level pagetables from highmem"
1665	depends on HIGHMEM
1666	---help---
1667	  The VM uses one page table entry for each page of physical memory.
1668	  For systems with a lot of RAM, this can be wasteful of precious
1669	  low memory.  Setting this option will put user-space page table
1670	  entries in high memory.
1671
1672config X86_CHECK_BIOS_CORRUPTION
1673	bool "Check for low memory corruption"
1674	---help---
1675	  Periodically check for memory corruption in low memory, which
1676	  is suspected to be caused by BIOS.  Even when enabled in the
1677	  configuration, it is disabled at runtime.  Enable it by
1678	  setting "memory_corruption_check=1" on the kernel command
1679	  line.  By default it scans the low 64k of memory every 60
1680	  seconds; see the memory_corruption_check_size and
1681	  memory_corruption_check_period parameters in
1682	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1683
1684	  When enabled with the default parameters, this option has
1685	  almost no overhead, as it reserves a relatively small amount
1686	  of memory and scans it infrequently.  It both detects corruption
1687	  and prevents it from affecting the running system.
1688
1689	  It is, however, intended as a diagnostic tool; if repeatable
1690	  BIOS-originated corruption always affects the same memory,
1691	  you can use memmap= to prevent the kernel from using that
1692	  memory.
1693
1694config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1695	bool "Set the default setting of memory_corruption_check"
1696	depends on X86_CHECK_BIOS_CORRUPTION
1697	default y
1698	---help---
1699	  Set whether the default state of memory_corruption_check is
1700	  on or off.
1701
1702config X86_RESERVE_LOW
1703	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1704	default 64
1705	range 4 640
1706	---help---
1707	  Specify the amount of low memory to reserve for the BIOS.
1708
1709	  The first page contains BIOS data structures that the kernel
1710	  must not use, so that page must always be reserved.
1711
1712	  By default we reserve the first 64K of physical RAM, as a
1713	  number of BIOSes are known to corrupt that memory range
1714	  during events such as suspend/resume or monitor cable
1715	  insertion, so it must not be used by the kernel.
1716
1717	  You can set this to 4 if you are absolutely sure that you
1718	  trust the BIOS to get all its memory reservations and usages
1719	  right.  If you know your BIOS have problems beyond the
1720	  default 64K area, you can set this to 640 to avoid using the
1721	  entire low memory range.
1722
1723	  If you have doubts about the BIOS (e.g. suspend/resume does
1724	  not work or there's kernel crashes after certain hardware
1725	  hotplug events) then you might want to enable
1726	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1727	  typical corruption patterns.
1728
1729	  Leave this to the default value of 64 if you are unsure.
1730
1731config MATH_EMULATION
1732	bool
1733	depends on MODIFY_LDT_SYSCALL
1734	prompt "Math emulation" if X86_32
1735	---help---
1736	  Linux can emulate a math coprocessor (used for floating point
1737	  operations) if you don't have one. 486DX and Pentium processors have
1738	  a math coprocessor built in, 486SX and 386 do not, unless you added
1739	  a 487DX or 387, respectively. (The messages during boot time can
1740	  give you some hints here ["man dmesg"].) Everyone needs either a
1741	  coprocessor or this emulation.
1742
1743	  If you don't have a math coprocessor, you need to say Y here; if you
1744	  say Y here even though you have a coprocessor, the coprocessor will
1745	  be used nevertheless. (This behavior can be changed with the kernel
1746	  command line option "no387", which comes handy if your coprocessor
1747	  is broken. Try "man bootparam" or see the documentation of your boot
1748	  loader (lilo or loadlin) about how to pass options to the kernel at
1749	  boot time.) This means that it is a good idea to say Y here if you
1750	  intend to use this kernel on different machines.
1751
1752	  More information about the internals of the Linux math coprocessor
1753	  emulation can be found in <file:arch/x86/math-emu/README>.
1754
1755	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1756	  kernel, it won't hurt.
1757
1758config MTRR
1759	def_bool y
1760	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1761	---help---
1762	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1763	  the Memory Type Range Registers (MTRRs) may be used to control
1764	  processor access to memory ranges. This is most useful if you have
1765	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1766	  allows bus write transfers to be combined into a larger transfer
1767	  before bursting over the PCI/AGP bus. This can increase performance
1768	  of image write operations 2.5 times or more. Saying Y here creates a
1769	  /proc/mtrr file which may be used to manipulate your processor's
1770	  MTRRs. Typically the X server should use this.
1771
1772	  This code has a reasonably generic interface so that similar
1773	  control registers on other processors can be easily supported
1774	  as well:
1775
1776	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1777	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1778	  these, the ARRs are used to emulate the MTRRs.
1779	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1780	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1781	  write-combining. All of these processors are supported by this code
1782	  and it makes sense to say Y here if you have one of them.
1783
1784	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1785	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1786	  can lead to all sorts of problems, so it's good to say Y here.
1787
1788	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1789	  just add about 9 KB to your kernel.
1790
1791	  See <file:Documentation/x86/mtrr.txt> for more information.
1792
1793config MTRR_SANITIZER
1794	def_bool y
1795	prompt "MTRR cleanup support"
1796	depends on MTRR
1797	---help---
1798	  Convert MTRR layout from continuous to discrete, so X drivers can
1799	  add writeback entries.
1800
1801	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1802	  The largest mtrr entry size for a continuous block can be set with
1803	  mtrr_chunk_size.
1804
1805	  If unsure, say Y.
1806
1807config MTRR_SANITIZER_ENABLE_DEFAULT
1808	int "MTRR cleanup enable value (0-1)"
1809	range 0 1
1810	default "0"
1811	depends on MTRR_SANITIZER
1812	---help---
1813	  Enable mtrr cleanup default value
1814
1815config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1816	int "MTRR cleanup spare reg num (0-7)"
1817	range 0 7
1818	default "1"
1819	depends on MTRR_SANITIZER
1820	---help---
1821	  mtrr cleanup spare entries default, it can be changed via
1822	  mtrr_spare_reg_nr=N on the kernel command line.
1823
1824config X86_PAT
1825	def_bool y
1826	prompt "x86 PAT support" if EXPERT
1827	depends on MTRR
1828	---help---
1829	  Use PAT attributes to setup page level cache control.
1830
1831	  PATs are the modern equivalents of MTRRs and are much more
1832	  flexible than MTRRs.
1833
1834	  Say N here if you see bootup problems (boot crash, boot hang,
1835	  spontaneous reboots) or a non-working video driver.
1836
1837	  If unsure, say Y.
1838
1839config ARCH_USES_PG_UNCACHED
1840	def_bool y
1841	depends on X86_PAT
1842
1843config ARCH_RANDOM
1844	def_bool y
1845	prompt "x86 architectural random number generator" if EXPERT
1846	---help---
1847	  Enable the x86 architectural RDRAND instruction
1848	  (Intel Bull Mountain technology) to generate random numbers.
1849	  If supported, this is a high bandwidth, cryptographically
1850	  secure hardware random number generator.
1851
1852config X86_SMAP
1853	def_bool y
1854	prompt "Supervisor Mode Access Prevention" if EXPERT
1855	---help---
1856	  Supervisor Mode Access Prevention (SMAP) is a security
1857	  feature in newer Intel processors.  There is a small
1858	  performance cost if this enabled and turned on; there is
1859	  also a small increase in the kernel size if this is enabled.
1860
1861	  If unsure, say Y.
1862
1863config X86_INTEL_UMIP
1864	def_bool y
1865	depends on CPU_SUP_INTEL
1866	prompt "Intel User Mode Instruction Prevention" if EXPERT
1867	---help---
1868	  The User Mode Instruction Prevention (UMIP) is a security
1869	  feature in newer Intel processors. If enabled, a general
1870	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1871	  or STR instructions are executed in user mode. These instructions
1872	  unnecessarily expose information about the hardware state.
1873
1874	  The vast majority of applications do not use these instructions.
1875	  For the very few that do, software emulation is provided in
1876	  specific cases in protected and virtual-8086 modes. Emulated
1877	  results are dummy.
1878
1879config X86_INTEL_MPX
1880	prompt "Intel MPX (Memory Protection Extensions)"
1881	def_bool n
1882	# Note: only available in 64-bit mode due to VMA flags shortage
1883	depends on CPU_SUP_INTEL && X86_64
1884	select ARCH_USES_HIGH_VMA_FLAGS
1885	---help---
1886	  MPX provides hardware features that can be used in
1887	  conjunction with compiler-instrumented code to check
1888	  memory references.  It is designed to detect buffer
1889	  overflow or underflow bugs.
1890
1891	  This option enables running applications which are
1892	  instrumented or otherwise use MPX.  It does not use MPX
1893	  itself inside the kernel or to protect the kernel
1894	  against bad memory references.
1895
1896	  Enabling this option will make the kernel larger:
1897	  ~8k of kernel text and 36 bytes of data on a 64-bit
1898	  defconfig.  It adds a long to the 'mm_struct' which
1899	  will increase the kernel memory overhead of each
1900	  process and adds some branches to paths used during
1901	  exec() and munmap().
1902
1903	  For details, see Documentation/x86/intel_mpx.txt
1904
1905	  If unsure, say N.
1906
1907config X86_INTEL_MEMORY_PROTECTION_KEYS
1908	prompt "Intel Memory Protection Keys"
1909	def_bool y
1910	# Note: only available in 64-bit mode
1911	depends on CPU_SUP_INTEL && X86_64
1912	select ARCH_USES_HIGH_VMA_FLAGS
1913	select ARCH_HAS_PKEYS
1914	---help---
1915	  Memory Protection Keys provides a mechanism for enforcing
1916	  page-based protections, but without requiring modification of the
1917	  page tables when an application changes protection domains.
1918
1919	  For details, see Documentation/x86/protection-keys.txt
1920
1921	  If unsure, say y.
1922
1923config EFI
1924	bool "EFI runtime service support"
1925	depends on ACPI
1926	select UCS2_STRING
1927	select EFI_RUNTIME_WRAPPERS
1928	---help---
1929	  This enables the kernel to use EFI runtime services that are
1930	  available (such as the EFI variable services).
1931
1932	  This option is only useful on systems that have EFI firmware.
1933	  In addition, you should use the latest ELILO loader available
1934	  at <http://elilo.sourceforge.net> in order to take advantage
1935	  of EFI runtime services. However, even with this option, the
1936	  resultant kernel should continue to boot on existing non-EFI
1937	  platforms.
1938
1939config EFI_STUB
1940       bool "EFI stub support"
1941       depends on EFI && !X86_USE_3DNOW
1942       select RELOCATABLE
1943       ---help---
1944          This kernel feature allows a bzImage to be loaded directly
1945	  by EFI firmware without the use of a bootloader.
1946
1947	  See Documentation/efi-stub.txt for more information.
1948
1949config EFI_MIXED
1950	bool "EFI mixed-mode support"
1951	depends on EFI_STUB && X86_64
1952	---help---
1953	   Enabling this feature allows a 64-bit kernel to be booted
1954	   on a 32-bit firmware, provided that your CPU supports 64-bit
1955	   mode.
1956
1957	   Note that it is not possible to boot a mixed-mode enabled
1958	   kernel via the EFI boot stub - a bootloader that supports
1959	   the EFI handover protocol must be used.
1960
1961	   If unsure, say N.
1962
1963config SECCOMP
1964	def_bool y
1965	prompt "Enable seccomp to safely compute untrusted bytecode"
1966	---help---
1967	  This kernel feature is useful for number crunching applications
1968	  that may need to compute untrusted bytecode during their
1969	  execution. By using pipes or other transports made available to
1970	  the process as file descriptors supporting the read/write
1971	  syscalls, it's possible to isolate those applications in
1972	  their own address space using seccomp. Once seccomp is
1973	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1974	  and the task is only allowed to execute a few safe syscalls
1975	  defined by each seccomp mode.
1976
1977	  If unsure, say Y. Only embedded should say N here.
1978
1979source kernel/Kconfig.hz
1980
1981config KEXEC
1982	bool "kexec system call"
1983	select KEXEC_CORE
1984	---help---
1985	  kexec is a system call that implements the ability to shutdown your
1986	  current kernel, and to start another kernel.  It is like a reboot
1987	  but it is independent of the system firmware.   And like a reboot
1988	  you can start any kernel with it, not just Linux.
1989
1990	  The name comes from the similarity to the exec system call.
1991
1992	  It is an ongoing process to be certain the hardware in a machine
1993	  is properly shutdown, so do not be surprised if this code does not
1994	  initially work for you.  As of this writing the exact hardware
1995	  interface is strongly in flux, so no good recommendation can be
1996	  made.
1997
1998config KEXEC_FILE
1999	bool "kexec file based system call"
2000	select KEXEC_CORE
2001	select BUILD_BIN2C
2002	depends on X86_64
2003	depends on CRYPTO=y
2004	depends on CRYPTO_SHA256=y
2005	---help---
2006	  This is new version of kexec system call. This system call is
2007	  file based and takes file descriptors as system call argument
2008	  for kernel and initramfs as opposed to list of segments as
2009	  accepted by previous system call.
2010
2011config ARCH_HAS_KEXEC_PURGATORY
2012	def_bool KEXEC_FILE
2013
2014config KEXEC_VERIFY_SIG
2015	bool "Verify kernel signature during kexec_file_load() syscall"
2016	depends on KEXEC_FILE
2017	---help---
2018	  This option makes kernel signature verification mandatory for
2019	  the kexec_file_load() syscall.
2020
2021	  In addition to that option, you need to enable signature
2022	  verification for the corresponding kernel image type being
2023	  loaded in order for this to work.
2024
2025config KEXEC_BZIMAGE_VERIFY_SIG
2026	bool "Enable bzImage signature verification support"
2027	depends on KEXEC_VERIFY_SIG
2028	depends on SIGNED_PE_FILE_VERIFICATION
2029	select SYSTEM_TRUSTED_KEYRING
2030	---help---
2031	  Enable bzImage signature verification support.
2032
2033config CRASH_DUMP
2034	bool "kernel crash dumps"
2035	depends on X86_64 || (X86_32 && HIGHMEM)
2036	---help---
2037	  Generate crash dump after being started by kexec.
2038	  This should be normally only set in special crash dump kernels
2039	  which are loaded in the main kernel with kexec-tools into
2040	  a specially reserved region and then later executed after
2041	  a crash by kdump/kexec. The crash dump kernel must be compiled
2042	  to a memory address not used by the main kernel or BIOS using
2043	  PHYSICAL_START, or it must be built as a relocatable image
2044	  (CONFIG_RELOCATABLE=y).
2045	  For more details see Documentation/kdump/kdump.txt
2046
2047config KEXEC_JUMP
2048	bool "kexec jump"
2049	depends on KEXEC && HIBERNATION
2050	---help---
2051	  Jump between original kernel and kexeced kernel and invoke
2052	  code in physical address mode via KEXEC
2053
2054config PHYSICAL_START
2055	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2056	default "0x1000000"
2057	---help---
2058	  This gives the physical address where the kernel is loaded.
2059
2060	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2061	  bzImage will decompress itself to above physical address and
2062	  run from there. Otherwise, bzImage will run from the address where
2063	  it has been loaded by the boot loader and will ignore above physical
2064	  address.
2065
2066	  In normal kdump cases one does not have to set/change this option
2067	  as now bzImage can be compiled as a completely relocatable image
2068	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2069	  address. This option is mainly useful for the folks who don't want
2070	  to use a bzImage for capturing the crash dump and want to use a
2071	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2072	  to be specifically compiled to run from a specific memory area
2073	  (normally a reserved region) and this option comes handy.
2074
2075	  So if you are using bzImage for capturing the crash dump,
2076	  leave the value here unchanged to 0x1000000 and set
2077	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2078	  for capturing the crash dump change this value to start of
2079	  the reserved region.  In other words, it can be set based on
2080	  the "X" value as specified in the "crashkernel=YM@XM"
2081	  command line boot parameter passed to the panic-ed
2082	  kernel. Please take a look at Documentation/kdump/kdump.txt
2083	  for more details about crash dumps.
2084
2085	  Usage of bzImage for capturing the crash dump is recommended as
2086	  one does not have to build two kernels. Same kernel can be used
2087	  as production kernel and capture kernel. Above option should have
2088	  gone away after relocatable bzImage support is introduced. But it
2089	  is present because there are users out there who continue to use
2090	  vmlinux for dump capture. This option should go away down the
2091	  line.
2092
2093	  Don't change this unless you know what you are doing.
2094
2095config RELOCATABLE
2096	bool "Build a relocatable kernel"
2097	default y
2098	---help---
2099	  This builds a kernel image that retains relocation information
2100	  so it can be loaded someplace besides the default 1MB.
2101	  The relocations tend to make the kernel binary about 10% larger,
2102	  but are discarded at runtime.
2103
2104	  One use is for the kexec on panic case where the recovery kernel
2105	  must live at a different physical address than the primary
2106	  kernel.
2107
2108	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2109	  it has been loaded at and the compile time physical address
2110	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2111
2112config RANDOMIZE_BASE
2113	bool "Randomize the address of the kernel image (KASLR)"
2114	depends on RELOCATABLE
2115	default y
2116	---help---
2117	  In support of Kernel Address Space Layout Randomization (KASLR),
2118	  this randomizes the physical address at which the kernel image
2119	  is decompressed and the virtual address where the kernel
2120	  image is mapped, as a security feature that deters exploit
2121	  attempts relying on knowledge of the location of kernel
2122	  code internals.
2123
2124	  On 64-bit, the kernel physical and virtual addresses are
2125	  randomized separately. The physical address will be anywhere
2126	  between 16MB and the top of physical memory (up to 64TB). The
2127	  virtual address will be randomized from 16MB up to 1GB (9 bits
2128	  of entropy). Note that this also reduces the memory space
2129	  available to kernel modules from 1.5GB to 1GB.
2130
2131	  On 32-bit, the kernel physical and virtual addresses are
2132	  randomized together. They will be randomized from 16MB up to
2133	  512MB (8 bits of entropy).
2134
2135	  Entropy is generated using the RDRAND instruction if it is
2136	  supported. If RDTSC is supported, its value is mixed into
2137	  the entropy pool as well. If neither RDRAND nor RDTSC are
2138	  supported, then entropy is read from the i8254 timer. The
2139	  usable entropy is limited by the kernel being built using
2140	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2141	  minimum of 2MB. As a result, only 10 bits of entropy are
2142	  theoretically possible, but the implementations are further
2143	  limited due to memory layouts.
2144
2145	  If unsure, say Y.
2146
2147# Relocation on x86 needs some additional build support
2148config X86_NEED_RELOCS
2149	def_bool y
2150	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2151
2152config PHYSICAL_ALIGN
2153	hex "Alignment value to which kernel should be aligned"
2154	default "0x200000"
2155	range 0x2000 0x1000000 if X86_32
2156	range 0x200000 0x1000000 if X86_64
2157	---help---
2158	  This value puts the alignment restrictions on physical address
2159	  where kernel is loaded and run from. Kernel is compiled for an
2160	  address which meets above alignment restriction.
2161
2162	  If bootloader loads the kernel at a non-aligned address and
2163	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2164	  address aligned to above value and run from there.
2165
2166	  If bootloader loads the kernel at a non-aligned address and
2167	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2168	  load address and decompress itself to the address it has been
2169	  compiled for and run from there. The address for which kernel is
2170	  compiled already meets above alignment restrictions. Hence the
2171	  end result is that kernel runs from a physical address meeting
2172	  above alignment restrictions.
2173
2174	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2175	  this value must be a multiple of 0x200000.
2176
2177	  Don't change this unless you know what you are doing.
2178
2179config DYNAMIC_MEMORY_LAYOUT
2180	bool
2181	---help---
2182	  This option makes base addresses of vmalloc and vmemmap as well as
2183	  __PAGE_OFFSET movable during boot.
2184
2185config RANDOMIZE_MEMORY
2186	bool "Randomize the kernel memory sections"
2187	depends on X86_64
2188	depends on RANDOMIZE_BASE
2189	select DYNAMIC_MEMORY_LAYOUT
2190	default RANDOMIZE_BASE
2191	---help---
2192	   Randomizes the base virtual address of kernel memory sections
2193	   (physical memory mapping, vmalloc & vmemmap). This security feature
2194	   makes exploits relying on predictable memory locations less reliable.
2195
2196	   The order of allocations remains unchanged. Entropy is generated in
2197	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2198	   configuration have in average 30,000 different possible virtual
2199	   addresses for each memory section.
2200
2201	   If unsure, say Y.
2202
2203config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2204	hex "Physical memory mapping padding" if EXPERT
2205	depends on RANDOMIZE_MEMORY
2206	default "0xa" if MEMORY_HOTPLUG
2207	default "0x0"
2208	range 0x1 0x40 if MEMORY_HOTPLUG
2209	range 0x0 0x40
2210	---help---
2211	   Define the padding in terabytes added to the existing physical
2212	   memory size during kernel memory randomization. It is useful
2213	   for memory hotplug support but reduces the entropy available for
2214	   address randomization.
2215
2216	   If unsure, leave at the default value.
2217
2218config HOTPLUG_CPU
2219	bool "Support for hot-pluggable CPUs"
2220	depends on SMP
2221	---help---
2222	  Say Y here to allow turning CPUs off and on. CPUs can be
2223	  controlled through /sys/devices/system/cpu.
2224	  ( Note: power management support will enable this option
2225	    automatically on SMP systems. )
2226	  Say N if you want to disable CPU hotplug.
2227
2228config BOOTPARAM_HOTPLUG_CPU0
2229	bool "Set default setting of cpu0_hotpluggable"
2230	depends on HOTPLUG_CPU
2231	---help---
2232	  Set whether default state of cpu0_hotpluggable is on or off.
2233
2234	  Say Y here to enable CPU0 hotplug by default. If this switch
2235	  is turned on, there is no need to give cpu0_hotplug kernel
2236	  parameter and the CPU0 hotplug feature is enabled by default.
2237
2238	  Please note: there are two known CPU0 dependencies if you want
2239	  to enable the CPU0 hotplug feature either by this switch or by
2240	  cpu0_hotplug kernel parameter.
2241
2242	  First, resume from hibernate or suspend always starts from CPU0.
2243	  So hibernate and suspend are prevented if CPU0 is offline.
2244
2245	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2246	  offline if any interrupt can not migrate out of CPU0. There may
2247	  be other CPU0 dependencies.
2248
2249	  Please make sure the dependencies are under your control before
2250	  you enable this feature.
2251
2252	  Say N if you don't want to enable CPU0 hotplug feature by default.
2253	  You still can enable the CPU0 hotplug feature at boot by kernel
2254	  parameter cpu0_hotplug.
2255
2256config DEBUG_HOTPLUG_CPU0
2257	def_bool n
2258	prompt "Debug CPU0 hotplug"
2259	depends on HOTPLUG_CPU
2260	---help---
2261	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2262	  soon as possible and boots up userspace with CPU0 offlined. User
2263	  can online CPU0 back after boot time.
2264
2265	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2266	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2267	  compilation or giving cpu0_hotplug kernel parameter at boot.
2268
2269	  If unsure, say N.
2270
2271config COMPAT_VDSO
2272	def_bool n
2273	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2274	depends on COMPAT_32
2275	---help---
2276	  Certain buggy versions of glibc will crash if they are
2277	  presented with a 32-bit vDSO that is not mapped at the address
2278	  indicated in its segment table.
2279
2280	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2281	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2282	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2283	  the only released version with the bug, but OpenSUSE 9
2284	  contains a buggy "glibc 2.3.2".
2285
2286	  The symptom of the bug is that everything crashes on startup, saying:
2287	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2288
2289	  Saying Y here changes the default value of the vdso32 boot
2290	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2291	  This works around the glibc bug but hurts performance.
2292
2293	  If unsure, say N: if you are compiling your own kernel, you
2294	  are unlikely to be using a buggy version of glibc.
2295
2296choice
2297	prompt "vsyscall table for legacy applications"
2298	depends on X86_64
2299	default LEGACY_VSYSCALL_EMULATE
2300	help
2301	  Legacy user code that does not know how to find the vDSO expects
2302	  to be able to issue three syscalls by calling fixed addresses in
2303	  kernel space. Since this location is not randomized with ASLR,
2304	  it can be used to assist security vulnerability exploitation.
2305
2306	  This setting can be changed at boot time via the kernel command
2307	  line parameter vsyscall=[emulate|none].
2308
2309	  On a system with recent enough glibc (2.14 or newer) and no
2310	  static binaries, you can say None without a performance penalty
2311	  to improve security.
2312
2313	  If unsure, select "Emulate".
2314
2315	config LEGACY_VSYSCALL_EMULATE
2316		bool "Emulate"
2317		help
2318		  The kernel traps and emulates calls into the fixed
2319		  vsyscall address mapping. This makes the mapping
2320		  non-executable, but it still contains known contents,
2321		  which could be used in certain rare security vulnerability
2322		  exploits. This configuration is recommended when userspace
2323		  still uses the vsyscall area.
2324
2325	config LEGACY_VSYSCALL_NONE
2326		bool "None"
2327		help
2328		  There will be no vsyscall mapping at all. This will
2329		  eliminate any risk of ASLR bypass due to the vsyscall
2330		  fixed address mapping. Attempts to use the vsyscalls
2331		  will be reported to dmesg, so that either old or
2332		  malicious userspace programs can be identified.
2333
2334endchoice
2335
2336config CMDLINE_BOOL
2337	bool "Built-in kernel command line"
2338	---help---
2339	  Allow for specifying boot arguments to the kernel at
2340	  build time.  On some systems (e.g. embedded ones), it is
2341	  necessary or convenient to provide some or all of the
2342	  kernel boot arguments with the kernel itself (that is,
2343	  to not rely on the boot loader to provide them.)
2344
2345	  To compile command line arguments into the kernel,
2346	  set this option to 'Y', then fill in the
2347	  boot arguments in CONFIG_CMDLINE.
2348
2349	  Systems with fully functional boot loaders (i.e. non-embedded)
2350	  should leave this option set to 'N'.
2351
2352config CMDLINE
2353	string "Built-in kernel command string"
2354	depends on CMDLINE_BOOL
2355	default ""
2356	---help---
2357	  Enter arguments here that should be compiled into the kernel
2358	  image and used at boot time.  If the boot loader provides a
2359	  command line at boot time, it is appended to this string to
2360	  form the full kernel command line, when the system boots.
2361
2362	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2363	  change this behavior.
2364
2365	  In most cases, the command line (whether built-in or provided
2366	  by the boot loader) should specify the device for the root
2367	  file system.
2368
2369config CMDLINE_OVERRIDE
2370	bool "Built-in command line overrides boot loader arguments"
2371	depends on CMDLINE_BOOL
2372	---help---
2373	  Set this option to 'Y' to have the kernel ignore the boot loader
2374	  command line, and use ONLY the built-in command line.
2375
2376	  This is used to work around broken boot loaders.  This should
2377	  be set to 'N' under normal conditions.
2378
2379config MODIFY_LDT_SYSCALL
2380	bool "Enable the LDT (local descriptor table)" if EXPERT
2381	default y
2382	---help---
2383	  Linux can allow user programs to install a per-process x86
2384	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2385	  call.  This is required to run 16-bit or segmented code such as
2386	  DOSEMU or some Wine programs.  It is also used by some very old
2387	  threading libraries.
2388
2389	  Enabling this feature adds a small amount of overhead to
2390	  context switches and increases the low-level kernel attack
2391	  surface.  Disabling it removes the modify_ldt(2) system call.
2392
2393	  Saying 'N' here may make sense for embedded or server kernels.
2394
2395source "kernel/livepatch/Kconfig"
2396
2397endmenu
2398
2399config ARCH_HAS_ADD_PAGES
2400	def_bool y
2401	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2402
2403config ARCH_ENABLE_MEMORY_HOTPLUG
2404	def_bool y
2405	depends on X86_64 || (X86_32 && HIGHMEM)
2406
2407config ARCH_ENABLE_MEMORY_HOTREMOVE
2408	def_bool y
2409	depends on MEMORY_HOTPLUG
2410
2411config USE_PERCPU_NUMA_NODE_ID
2412	def_bool y
2413	depends on NUMA
2414
2415config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2416	def_bool y
2417	depends on X86_64 || X86_PAE
2418
2419config ARCH_ENABLE_HUGEPAGE_MIGRATION
2420	def_bool y
2421	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2422
2423config ARCH_ENABLE_THP_MIGRATION
2424	def_bool y
2425	depends on X86_64 && TRANSPARENT_HUGEPAGE
2426
2427menu "Power management and ACPI options"
2428
2429config ARCH_HIBERNATION_HEADER
2430	def_bool y
2431	depends on HIBERNATION
2432
2433source "kernel/power/Kconfig"
2434
2435source "drivers/acpi/Kconfig"
2436
2437source "drivers/sfi/Kconfig"
2438
2439config X86_APM_BOOT
2440	def_bool y
2441	depends on APM
2442
2443menuconfig APM
2444	tristate "APM (Advanced Power Management) BIOS support"
2445	depends on X86_32 && PM_SLEEP
2446	---help---
2447	  APM is a BIOS specification for saving power using several different
2448	  techniques. This is mostly useful for battery powered laptops with
2449	  APM compliant BIOSes. If you say Y here, the system time will be
2450	  reset after a RESUME operation, the /proc/apm device will provide
2451	  battery status information, and user-space programs will receive
2452	  notification of APM "events" (e.g. battery status change).
2453
2454	  If you select "Y" here, you can disable actual use of the APM
2455	  BIOS by passing the "apm=off" option to the kernel at boot time.
2456
2457	  Note that the APM support is almost completely disabled for
2458	  machines with more than one CPU.
2459
2460	  In order to use APM, you will need supporting software. For location
2461	  and more information, read <file:Documentation/power/apm-acpi.txt>
2462	  and the Battery Powered Linux mini-HOWTO, available from
2463	  <http://www.tldp.org/docs.html#howto>.
2464
2465	  This driver does not spin down disk drives (see the hdparm(8)
2466	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2467	  VESA-compliant "green" monitors.
2468
2469	  This driver does not support the TI 4000M TravelMate and the ACER
2470	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2471	  desktop machines also don't have compliant BIOSes, and this driver
2472	  may cause those machines to panic during the boot phase.
2473
2474	  Generally, if you don't have a battery in your machine, there isn't
2475	  much point in using this driver and you should say N. If you get
2476	  random kernel OOPSes or reboots that don't seem to be related to
2477	  anything, try disabling/enabling this option (or disabling/enabling
2478	  APM in your BIOS).
2479
2480	  Some other things you should try when experiencing seemingly random,
2481	  "weird" problems:
2482
2483	  1) make sure that you have enough swap space and that it is
2484	  enabled.
2485	  2) pass the "no-hlt" option to the kernel
2486	  3) switch on floating point emulation in the kernel and pass
2487	  the "no387" option to the kernel
2488	  4) pass the "floppy=nodma" option to the kernel
2489	  5) pass the "mem=4M" option to the kernel (thereby disabling
2490	  all but the first 4 MB of RAM)
2491	  6) make sure that the CPU is not over clocked.
2492	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2493	  8) disable the cache from your BIOS settings
2494	  9) install a fan for the video card or exchange video RAM
2495	  10) install a better fan for the CPU
2496	  11) exchange RAM chips
2497	  12) exchange the motherboard.
2498
2499	  To compile this driver as a module, choose M here: the
2500	  module will be called apm.
2501
2502if APM
2503
2504config APM_IGNORE_USER_SUSPEND
2505	bool "Ignore USER SUSPEND"
2506	---help---
2507	  This option will ignore USER SUSPEND requests. On machines with a
2508	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2509	  series notebooks, it is necessary to say Y because of a BIOS bug.
2510
2511config APM_DO_ENABLE
2512	bool "Enable PM at boot time"
2513	---help---
2514	  Enable APM features at boot time. From page 36 of the APM BIOS
2515	  specification: "When disabled, the APM BIOS does not automatically
2516	  power manage devices, enter the Standby State, enter the Suspend
2517	  State, or take power saving steps in response to CPU Idle calls."
2518	  This driver will make CPU Idle calls when Linux is idle (unless this
2519	  feature is turned off -- see "Do CPU IDLE calls", below). This
2520	  should always save battery power, but more complicated APM features
2521	  will be dependent on your BIOS implementation. You may need to turn
2522	  this option off if your computer hangs at boot time when using APM
2523	  support, or if it beeps continuously instead of suspending. Turn
2524	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2525	  T400CDT. This is off by default since most machines do fine without
2526	  this feature.
2527
2528config APM_CPU_IDLE
2529	depends on CPU_IDLE
2530	bool "Make CPU Idle calls when idle"
2531	---help---
2532	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2533	  On some machines, this can activate improved power savings, such as
2534	  a slowed CPU clock rate, when the machine is idle. These idle calls
2535	  are made after the idle loop has run for some length of time (e.g.,
2536	  333 mS). On some machines, this will cause a hang at boot time or
2537	  whenever the CPU becomes idle. (On machines with more than one CPU,
2538	  this option does nothing.)
2539
2540config APM_DISPLAY_BLANK
2541	bool "Enable console blanking using APM"
2542	---help---
2543	  Enable console blanking using the APM. Some laptops can use this to
2544	  turn off the LCD backlight when the screen blanker of the Linux
2545	  virtual console blanks the screen. Note that this is only used by
2546	  the virtual console screen blanker, and won't turn off the backlight
2547	  when using the X Window system. This also doesn't have anything to
2548	  do with your VESA-compliant power-saving monitor. Further, this
2549	  option doesn't work for all laptops -- it might not turn off your
2550	  backlight at all, or it might print a lot of errors to the console,
2551	  especially if you are using gpm.
2552
2553config APM_ALLOW_INTS
2554	bool "Allow interrupts during APM BIOS calls"
2555	---help---
2556	  Normally we disable external interrupts while we are making calls to
2557	  the APM BIOS as a measure to lessen the effects of a badly behaving
2558	  BIOS implementation.  The BIOS should reenable interrupts if it
2559	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2560	  many of the newer IBM Thinkpads.  If you experience hangs when you
2561	  suspend, try setting this to Y.  Otherwise, say N.
2562
2563endif # APM
2564
2565source "drivers/cpufreq/Kconfig"
2566
2567source "drivers/cpuidle/Kconfig"
2568
2569source "drivers/idle/Kconfig"
2570
2571endmenu
2572
2573
2574menu "Bus options (PCI etc.)"
2575
2576config PCI
2577	bool "PCI support"
2578	default y
2579	---help---
2580	  Find out whether you have a PCI motherboard. PCI is the name of a
2581	  bus system, i.e. the way the CPU talks to the other stuff inside
2582	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2583	  VESA. If you have PCI, say Y, otherwise N.
2584
2585choice
2586	prompt "PCI access mode"
2587	depends on X86_32 && PCI
2588	default PCI_GOANY
2589	---help---
2590	  On PCI systems, the BIOS can be used to detect the PCI devices and
2591	  determine their configuration. However, some old PCI motherboards
2592	  have BIOS bugs and may crash if this is done. Also, some embedded
2593	  PCI-based systems don't have any BIOS at all. Linux can also try to
2594	  detect the PCI hardware directly without using the BIOS.
2595
2596	  With this option, you can specify how Linux should detect the
2597	  PCI devices. If you choose "BIOS", the BIOS will be used,
2598	  if you choose "Direct", the BIOS won't be used, and if you
2599	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2600	  If you choose "Any", the kernel will try MMCONFIG, then the
2601	  direct access method and falls back to the BIOS if that doesn't
2602	  work. If unsure, go with the default, which is "Any".
2603
2604config PCI_GOBIOS
2605	bool "BIOS"
2606
2607config PCI_GOMMCONFIG
2608	bool "MMConfig"
2609
2610config PCI_GODIRECT
2611	bool "Direct"
2612
2613config PCI_GOOLPC
2614	bool "OLPC XO-1"
2615	depends on OLPC
2616
2617config PCI_GOANY
2618	bool "Any"
2619
2620endchoice
2621
2622config PCI_BIOS
2623	def_bool y
2624	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2625
2626# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2627config PCI_DIRECT
2628	def_bool y
2629	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2630
2631config PCI_MMCONFIG
2632	bool "Support mmconfig PCI config space access" if X86_64
2633	default y
2634	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2635	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2636
2637config PCI_OLPC
2638	def_bool y
2639	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2640
2641config PCI_XEN
2642	def_bool y
2643	depends on PCI && XEN
2644	select SWIOTLB_XEN
2645
2646config PCI_DOMAINS
2647	def_bool y
2648	depends on PCI
2649
2650config MMCONF_FAM10H
2651	def_bool y
2652	depends on X86_64 && PCI_MMCONFIG && ACPI
2653
2654config PCI_CNB20LE_QUIRK
2655	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2656	depends on PCI
2657	help
2658	  Read the PCI windows out of the CNB20LE host bridge. This allows
2659	  PCI hotplug to work on systems with the CNB20LE chipset which do
2660	  not have ACPI.
2661
2662	  There's no public spec for this chipset, and this functionality
2663	  is known to be incomplete.
2664
2665	  You should say N unless you know you need this.
2666
2667source "drivers/pci/Kconfig"
2668
2669config ISA_BUS
2670	bool "ISA bus support on modern systems" if EXPERT
2671	help
2672	  Expose ISA bus device drivers and options available for selection and
2673	  configuration. Enable this option if your target machine has an ISA
2674	  bus. ISA is an older system, displaced by PCI and newer bus
2675	  architectures -- if your target machine is modern, it probably does
2676	  not have an ISA bus.
2677
2678	  If unsure, say N.
2679
2680# x86_64 have no ISA slots, but can have ISA-style DMA.
2681config ISA_DMA_API
2682	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2683	default y
2684	help
2685	  Enables ISA-style DMA support for devices requiring such controllers.
2686	  If unsure, say Y.
2687
2688if X86_32
2689
2690config ISA
2691	bool "ISA support"
2692	---help---
2693	  Find out whether you have ISA slots on your motherboard.  ISA is the
2694	  name of a bus system, i.e. the way the CPU talks to the other stuff
2695	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2696	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2697	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2698
2699config EISA
2700	bool "EISA support"
2701	depends on ISA
2702	---help---
2703	  The Extended Industry Standard Architecture (EISA) bus was
2704	  developed as an open alternative to the IBM MicroChannel bus.
2705
2706	  The EISA bus provided some of the features of the IBM MicroChannel
2707	  bus while maintaining backward compatibility with cards made for
2708	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2709	  1995 when it was made obsolete by the PCI bus.
2710
2711	  Say Y here if you are building a kernel for an EISA-based machine.
2712
2713	  Otherwise, say N.
2714
2715source "drivers/eisa/Kconfig"
2716
2717config SCx200
2718	tristate "NatSemi SCx200 support"
2719	---help---
2720	  This provides basic support for National Semiconductor's
2721	  (now AMD's) Geode processors.  The driver probes for the
2722	  PCI-IDs of several on-chip devices, so its a good dependency
2723	  for other scx200_* drivers.
2724
2725	  If compiled as a module, the driver is named scx200.
2726
2727config SCx200HR_TIMER
2728	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2729	depends on SCx200
2730	default y
2731	---help---
2732	  This driver provides a clocksource built upon the on-chip
2733	  27MHz high-resolution timer.  Its also a workaround for
2734	  NSC Geode SC-1100's buggy TSC, which loses time when the
2735	  processor goes idle (as is done by the scheduler).  The
2736	  other workaround is idle=poll boot option.
2737
2738config OLPC
2739	bool "One Laptop Per Child support"
2740	depends on !X86_PAE
2741	select GPIOLIB
2742	select OF
2743	select OF_PROMTREE
2744	select IRQ_DOMAIN
2745	---help---
2746	  Add support for detecting the unique features of the OLPC
2747	  XO hardware.
2748
2749config OLPC_XO1_PM
2750	bool "OLPC XO-1 Power Management"
2751	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2752	---help---
2753	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2754
2755config OLPC_XO1_RTC
2756	bool "OLPC XO-1 Real Time Clock"
2757	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2758	---help---
2759	  Add support for the XO-1 real time clock, which can be used as a
2760	  programmable wakeup source.
2761
2762config OLPC_XO1_SCI
2763	bool "OLPC XO-1 SCI extras"
2764	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2765	depends on INPUT=y
2766	select POWER_SUPPLY
2767	---help---
2768	  Add support for SCI-based features of the OLPC XO-1 laptop:
2769	   - EC-driven system wakeups
2770	   - Power button
2771	   - Ebook switch
2772	   - Lid switch
2773	   - AC adapter status updates
2774	   - Battery status updates
2775
2776config OLPC_XO15_SCI
2777	bool "OLPC XO-1.5 SCI extras"
2778	depends on OLPC && ACPI
2779	select POWER_SUPPLY
2780	---help---
2781	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2782	   - EC-driven system wakeups
2783	   - AC adapter status updates
2784	   - Battery status updates
2785
2786config ALIX
2787	bool "PCEngines ALIX System Support (LED setup)"
2788	select GPIOLIB
2789	---help---
2790	  This option enables system support for the PCEngines ALIX.
2791	  At present this just sets up LEDs for GPIO control on
2792	  ALIX2/3/6 boards.  However, other system specific setup should
2793	  get added here.
2794
2795	  Note: You must still enable the drivers for GPIO and LED support
2796	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2797
2798	  Note: You have to set alix.force=1 for boards with Award BIOS.
2799
2800config NET5501
2801	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2802	select GPIOLIB
2803	---help---
2804	  This option enables system support for the Soekris Engineering net5501.
2805
2806config GEOS
2807	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2808	select GPIOLIB
2809	depends on DMI
2810	---help---
2811	  This option enables system support for the Traverse Technologies GEOS.
2812
2813config TS5500
2814	bool "Technologic Systems TS-5500 platform support"
2815	depends on MELAN
2816	select CHECK_SIGNATURE
2817	select NEW_LEDS
2818	select LEDS_CLASS
2819	---help---
2820	  This option enables system support for the Technologic Systems TS-5500.
2821
2822endif # X86_32
2823
2824config AMD_NB
2825	def_bool y
2826	depends on CPU_SUP_AMD && PCI
2827
2828source "drivers/pcmcia/Kconfig"
2829
2830config RAPIDIO
2831	tristate "RapidIO support"
2832	depends on PCI
2833	help
2834	  If enabled this option will include drivers and the core
2835	  infrastructure code to support RapidIO interconnect devices.
2836
2837source "drivers/rapidio/Kconfig"
2838
2839config X86_SYSFB
2840	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2841	help
2842	  Firmwares often provide initial graphics framebuffers so the BIOS,
2843	  bootloader or kernel can show basic video-output during boot for
2844	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2845	  Extensions and EFI-framebuffers for this, which are mostly limited
2846	  to x86.
2847	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2848	  framebuffers so the new generic system-framebuffer drivers can be
2849	  used on x86. If the framebuffer is not compatible with the generic
2850	  modes, it is advertised as fallback platform framebuffer so legacy
2851	  drivers like efifb, vesafb and uvesafb can pick it up.
2852	  If this option is not selected, all system framebuffers are always
2853	  marked as fallback platform framebuffers as usual.
2854
2855	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2856	  not be able to pick up generic system framebuffers if this option
2857	  is selected. You are highly encouraged to enable simplefb as
2858	  replacement if you select this option. simplefb can correctly deal
2859	  with generic system framebuffers. But you should still keep vesafb
2860	  and others enabled as fallback if a system framebuffer is
2861	  incompatible with simplefb.
2862
2863	  If unsure, say Y.
2864
2865endmenu
2866
2867
2868menu "Binary Emulations"
2869
2870config IA32_EMULATION
2871	bool "IA32 Emulation"
2872	depends on X86_64
2873	select ARCH_WANT_OLD_COMPAT_IPC
2874	select BINFMT_ELF
2875	select COMPAT_BINFMT_ELF
2876	select COMPAT_OLD_SIGACTION
2877	---help---
2878	  Include code to run legacy 32-bit programs under a
2879	  64-bit kernel. You should likely turn this on, unless you're
2880	  100% sure that you don't have any 32-bit programs left.
2881
2882config IA32_AOUT
2883	tristate "IA32 a.out support"
2884	depends on IA32_EMULATION
2885	---help---
2886	  Support old a.out binaries in the 32bit emulation.
2887
2888config X86_X32
2889	bool "x32 ABI for 64-bit mode"
2890	depends on X86_64
2891	---help---
2892	  Include code to run binaries for the x32 native 32-bit ABI
2893	  for 64-bit processors.  An x32 process gets access to the
2894	  full 64-bit register file and wide data path while leaving
2895	  pointers at 32 bits for smaller memory footprint.
2896
2897	  You will need a recent binutils (2.22 or later) with
2898	  elf32_x86_64 support enabled to compile a kernel with this
2899	  option set.
2900
2901config COMPAT_32
2902	def_bool y
2903	depends on IA32_EMULATION || X86_32
2904	select HAVE_UID16
2905	select OLD_SIGSUSPEND3
2906
2907config COMPAT
2908	def_bool y
2909	depends on IA32_EMULATION || X86_X32
2910
2911if COMPAT
2912config COMPAT_FOR_U64_ALIGNMENT
2913	def_bool y
2914
2915config SYSVIPC_COMPAT
2916	def_bool y
2917	depends on SYSVIPC
2918endif
2919
2920endmenu
2921
2922
2923config HAVE_ATOMIC_IOMAP
2924	def_bool y
2925	depends on X86_32
2926
2927config X86_DEV_DMA_OPS
2928	bool
2929	depends on X86_64 || STA2X11
2930
2931config X86_DMA_REMAP
2932	bool
2933	depends on STA2X11
2934
2935config HAVE_GENERIC_GUP
2936	def_bool y
2937
2938source "drivers/firmware/Kconfig"
2939
2940source "arch/x86/kvm/Kconfig"
2941