xref: /openbmc/linux/arch/x86/Kconfig (revision a99237af)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select X86_DEV_DMA_OPS
34	select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40#   ported to 32-bit as well. )
41#
42config X86
43	def_bool y
44	#
45	# Note: keep this list sorted alphabetically
46	#
47	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
48	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
49	select ANON_INODES
50	select ARCH_CLOCKSOURCE_DATA
51	select ARCH_DISCARD_MEMBLOCK
52	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
53	select ARCH_HAS_DEBUG_VIRTUAL
54	select ARCH_HAS_DEVMEM_IS_ALLOWED
55	select ARCH_HAS_ELF_RANDOMIZE
56	select ARCH_HAS_FAST_MULTIPLIER
57	select ARCH_HAS_FILTER_PGPROT
58	select ARCH_HAS_FORTIFY_SOURCE
59	select ARCH_HAS_GCOV_PROFILE_ALL
60	select ARCH_HAS_KCOV			if X86_64
61	select ARCH_HAS_MEMBARRIER_SYNC_CORE
62	select ARCH_HAS_PMEM_API		if X86_64
63	select ARCH_HAS_PTE_SPECIAL
64	select ARCH_HAS_REFCOUNT
65	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
66	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
67	select ARCH_HAS_SET_MEMORY
68	select ARCH_HAS_SG_CHAIN
69	select ARCH_HAS_STRICT_KERNEL_RWX
70	select ARCH_HAS_STRICT_MODULE_RWX
71	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
72	select ARCH_HAS_UBSAN_SANITIZE_ALL
73	select ARCH_HAS_ZONE_DEVICE		if X86_64
74	select ARCH_HAVE_NMI_SAFE_CMPXCHG
75	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
76	select ARCH_MIGHT_HAVE_PC_PARPORT
77	select ARCH_MIGHT_HAVE_PC_SERIO
78	select ARCH_SUPPORTS_ACPI
79	select ARCH_SUPPORTS_ATOMIC_RMW
80	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
81	select ARCH_USE_BUILTIN_BSWAP
82	select ARCH_USE_QUEUED_RWLOCKS
83	select ARCH_USE_QUEUED_SPINLOCKS
84	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
85	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
86	select ARCH_WANTS_THP_SWAP		if X86_64
87	select BUILDTIME_EXTABLE_SORT
88	select CLKEVT_I8253
89	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
90	select CLOCKSOURCE_WATCHDOG
91	select DCACHE_WORD_ACCESS
92	select DMA_DIRECT_OPS
93	select EDAC_ATOMIC_SCRUB
94	select EDAC_SUPPORT
95	select GENERIC_CLOCKEVENTS
96	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
97	select GENERIC_CLOCKEVENTS_MIN_ADJUST
98	select GENERIC_CMOS_UPDATE
99	select GENERIC_CPU_AUTOPROBE
100	select GENERIC_CPU_VULNERABILITIES
101	select GENERIC_EARLY_IOREMAP
102	select GENERIC_FIND_FIRST_BIT
103	select GENERIC_IOMAP
104	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
105	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
106	select GENERIC_IRQ_MIGRATION		if SMP
107	select GENERIC_IRQ_PROBE
108	select GENERIC_IRQ_RESERVATION_MODE
109	select GENERIC_IRQ_SHOW
110	select GENERIC_PENDING_IRQ		if SMP
111	select GENERIC_SMP_IDLE_THREAD
112	select GENERIC_STRNCPY_FROM_USER
113	select GENERIC_STRNLEN_USER
114	select GENERIC_TIME_VSYSCALL
115	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
116	select HAVE_ACPI_APEI			if ACPI
117	select HAVE_ACPI_APEI_NMI		if ACPI
118	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
119	select HAVE_ARCH_AUDITSYSCALL
120	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
121	select HAVE_ARCH_JUMP_LABEL
122	select HAVE_ARCH_KASAN			if X86_64
123	select HAVE_ARCH_KGDB
124	select HAVE_ARCH_MMAP_RND_BITS		if MMU
125	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
126	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
127	select HAVE_ARCH_PREL32_RELOCATIONS
128	select HAVE_ARCH_SECCOMP_FILTER
129	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
130	select HAVE_ARCH_TRACEHOOK
131	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
132	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
133	select HAVE_ARCH_VMAP_STACK		if X86_64
134	select HAVE_ARCH_WITHIN_STACK_FRAMES
135	select HAVE_CMPXCHG_DOUBLE
136	select HAVE_CMPXCHG_LOCAL
137	select HAVE_CONTEXT_TRACKING		if X86_64
138	select HAVE_COPY_THREAD_TLS
139	select HAVE_C_RECORDMCOUNT
140	select HAVE_DEBUG_KMEMLEAK
141	select HAVE_DEBUG_STACKOVERFLOW
142	select HAVE_DMA_CONTIGUOUS
143	select HAVE_DYNAMIC_FTRACE
144	select HAVE_DYNAMIC_FTRACE_WITH_REGS
145	select HAVE_EBPF_JIT
146	select HAVE_EFFICIENT_UNALIGNED_ACCESS
147	select HAVE_EXIT_THREAD
148	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
149	select HAVE_FTRACE_MCOUNT_RECORD
150	select HAVE_FUNCTION_GRAPH_TRACER
151	select HAVE_FUNCTION_TRACER
152	select HAVE_GCC_PLUGINS
153	select HAVE_HW_BREAKPOINT
154	select HAVE_IDE
155	select HAVE_IOREMAP_PROT
156	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
157	select HAVE_IRQ_TIME_ACCOUNTING
158	select HAVE_KERNEL_BZIP2
159	select HAVE_KERNEL_GZIP
160	select HAVE_KERNEL_LZ4
161	select HAVE_KERNEL_LZMA
162	select HAVE_KERNEL_LZO
163	select HAVE_KERNEL_XZ
164	select HAVE_KPROBES
165	select HAVE_KPROBES_ON_FTRACE
166	select HAVE_FUNCTION_ERROR_INJECTION
167	select HAVE_KRETPROBES
168	select HAVE_KVM
169	select HAVE_LIVEPATCH			if X86_64
170	select HAVE_MEMBLOCK
171	select HAVE_MEMBLOCK_NODE_MAP
172	select HAVE_MIXED_BREAKPOINTS_REGS
173	select HAVE_MOD_ARCH_SPECIFIC
174	select HAVE_NMI
175	select HAVE_OPROFILE
176	select HAVE_OPTPROBES
177	select HAVE_PCSPKR_PLATFORM
178	select HAVE_PERF_EVENTS
179	select HAVE_PERF_EVENTS_NMI
180	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
181	select HAVE_PERF_REGS
182	select HAVE_PERF_USER_STACK_DUMP
183	select HAVE_RCU_TABLE_FREE
184	select HAVE_REGS_AND_STACK_ACCESS_API
185	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
186	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
187	select HAVE_STACK_VALIDATION		if X86_64
188	select HAVE_RSEQ
189	select HAVE_SYSCALL_TRACEPOINTS
190	select HAVE_UNSTABLE_SCHED_CLOCK
191	select HAVE_USER_RETURN_NOTIFIER
192	select HOTPLUG_SMT			if SMP
193	select IRQ_FORCED_THREADING
194	select NEED_SG_DMA_LENGTH
195	select PCI_LOCKLESS_CONFIG
196	select PERF_EVENTS
197	select RTC_LIB
198	select RTC_MC146818_LIB
199	select SPARSE_IRQ
200	select SRCU
201	select SYSCTL_EXCEPTION_TRACE
202	select THREAD_INFO_IN_TASK
203	select USER_STACKTRACE_SUPPORT
204	select VIRT_TO_BUS
205	select X86_FEATURE_NAMES		if PROC_FS
206
207config INSTRUCTION_DECODER
208	def_bool y
209	depends on KPROBES || PERF_EVENTS || UPROBES
210
211config OUTPUT_FORMAT
212	string
213	default "elf32-i386" if X86_32
214	default "elf64-x86-64" if X86_64
215
216config ARCH_DEFCONFIG
217	string
218	default "arch/x86/configs/i386_defconfig" if X86_32
219	default "arch/x86/configs/x86_64_defconfig" if X86_64
220
221config LOCKDEP_SUPPORT
222	def_bool y
223
224config STACKTRACE_SUPPORT
225	def_bool y
226
227config MMU
228	def_bool y
229
230config ARCH_MMAP_RND_BITS_MIN
231	default 28 if 64BIT
232	default 8
233
234config ARCH_MMAP_RND_BITS_MAX
235	default 32 if 64BIT
236	default 16
237
238config ARCH_MMAP_RND_COMPAT_BITS_MIN
239	default 8
240
241config ARCH_MMAP_RND_COMPAT_BITS_MAX
242	default 16
243
244config SBUS
245	bool
246
247config GENERIC_ISA_DMA
248	def_bool y
249	depends on ISA_DMA_API
250
251config GENERIC_BUG
252	def_bool y
253	depends on BUG
254	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
255
256config GENERIC_BUG_RELATIVE_POINTERS
257	bool
258
259config GENERIC_HWEIGHT
260	def_bool y
261
262config ARCH_MAY_HAVE_PC_FDC
263	def_bool y
264	depends on ISA_DMA_API
265
266config RWSEM_XCHGADD_ALGORITHM
267	def_bool y
268
269config GENERIC_CALIBRATE_DELAY
270	def_bool y
271
272config ARCH_HAS_CPU_RELAX
273	def_bool y
274
275config ARCH_HAS_CACHE_LINE_SIZE
276	def_bool y
277
278config ARCH_HAS_FILTER_PGPROT
279	def_bool y
280
281config HAVE_SETUP_PER_CPU_AREA
282	def_bool y
283
284config NEED_PER_CPU_EMBED_FIRST_CHUNK
285	def_bool y
286
287config NEED_PER_CPU_PAGE_FIRST_CHUNK
288	def_bool y
289
290config ARCH_HIBERNATION_POSSIBLE
291	def_bool y
292
293config ARCH_SUSPEND_POSSIBLE
294	def_bool y
295
296config ARCH_WANT_HUGE_PMD_SHARE
297	def_bool y
298
299config ARCH_WANT_GENERAL_HUGETLB
300	def_bool y
301
302config ZONE_DMA32
303	def_bool y if X86_64
304
305config AUDIT_ARCH
306	def_bool y if X86_64
307
308config ARCH_SUPPORTS_OPTIMIZED_INLINING
309	def_bool y
310
311config ARCH_SUPPORTS_DEBUG_PAGEALLOC
312	def_bool y
313
314config KASAN_SHADOW_OFFSET
315	hex
316	depends on KASAN
317	default 0xdffffc0000000000
318
319config HAVE_INTEL_TXT
320	def_bool y
321	depends on INTEL_IOMMU && ACPI
322
323config X86_32_SMP
324	def_bool y
325	depends on X86_32 && SMP
326
327config X86_64_SMP
328	def_bool y
329	depends on X86_64 && SMP
330
331config X86_32_LAZY_GS
332	def_bool y
333	depends on X86_32 && !STACKPROTECTOR
334
335config ARCH_SUPPORTS_UPROBES
336	def_bool y
337
338config FIX_EARLYCON_MEM
339	def_bool y
340
341config DYNAMIC_PHYSICAL_MASK
342	bool
343
344config PGTABLE_LEVELS
345	int
346	default 5 if X86_5LEVEL
347	default 4 if X86_64
348	default 3 if X86_PAE
349	default 2
350
351config CC_HAS_SANE_STACKPROTECTOR
352	bool
353	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
354	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
355	help
356	   We have to make sure stack protector is unconditionally disabled if
357	   the compiler produces broken code.
358
359menu "Processor type and features"
360
361config ZONE_DMA
362	bool "DMA memory allocation support" if EXPERT
363	default y
364	help
365	  DMA memory allocation support allows devices with less than 32-bit
366	  addressing to allocate within the first 16MB of address space.
367	  Disable if no such devices will be used.
368
369	  If unsure, say Y.
370
371config SMP
372	bool "Symmetric multi-processing support"
373	---help---
374	  This enables support for systems with more than one CPU. If you have
375	  a system with only one CPU, say N. If you have a system with more
376	  than one CPU, say Y.
377
378	  If you say N here, the kernel will run on uni- and multiprocessor
379	  machines, but will use only one CPU of a multiprocessor machine. If
380	  you say Y here, the kernel will run on many, but not all,
381	  uniprocessor machines. On a uniprocessor machine, the kernel
382	  will run faster if you say N here.
383
384	  Note that if you say Y here and choose architecture "586" or
385	  "Pentium" under "Processor family", the kernel will not work on 486
386	  architectures. Similarly, multiprocessor kernels for the "PPro"
387	  architecture may not work on all Pentium based boards.
388
389	  People using multiprocessor machines who say Y here should also say
390	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
391	  Management" code will be disabled if you say Y here.
392
393	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
394	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
395	  <http://www.tldp.org/docs.html#howto>.
396
397	  If you don't know what to do here, say N.
398
399config X86_FEATURE_NAMES
400	bool "Processor feature human-readable names" if EMBEDDED
401	default y
402	---help---
403	  This option compiles in a table of x86 feature bits and corresponding
404	  names.  This is required to support /proc/cpuinfo and a few kernel
405	  messages.  You can disable this to save space, at the expense of
406	  making those few kernel messages show numeric feature bits instead.
407
408	  If in doubt, say Y.
409
410config X86_X2APIC
411	bool "Support x2apic"
412	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
413	---help---
414	  This enables x2apic support on CPUs that have this feature.
415
416	  This allows 32-bit apic IDs (so it can support very large systems),
417	  and accesses the local apic via MSRs not via mmio.
418
419	  If you don't know what to do here, say N.
420
421config X86_MPPARSE
422	bool "Enable MPS table" if ACPI || SFI
423	default y
424	depends on X86_LOCAL_APIC
425	---help---
426	  For old smp systems that do not have proper acpi support. Newer systems
427	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
428
429config GOLDFISH
430       def_bool y
431       depends on X86_GOLDFISH
432
433config RETPOLINE
434	bool "Avoid speculative indirect branches in kernel"
435	default y
436	select STACK_VALIDATION if HAVE_STACK_VALIDATION
437	help
438	  Compile kernel with the retpoline compiler options to guard against
439	  kernel-to-user data leaks by avoiding speculative indirect
440	  branches. Requires a compiler with -mindirect-branch=thunk-extern
441	  support for full protection. The kernel may run slower.
442
443	  Without compiler support, at least indirect branches in assembler
444	  code are eliminated. Since this includes the syscall entry path,
445	  it is not entirely pointless.
446
447config INTEL_RDT
448	bool "Intel Resource Director Technology support"
449	default n
450	depends on X86 && CPU_SUP_INTEL
451	select KERNFS
452	help
453	  Select to enable resource allocation and monitoring which are
454	  sub-features of Intel Resource Director Technology(RDT). More
455	  information about RDT can be found in the Intel x86
456	  Architecture Software Developer Manual.
457
458	  Say N if unsure.
459
460if X86_32
461config X86_BIGSMP
462	bool "Support for big SMP systems with more than 8 CPUs"
463	depends on SMP
464	---help---
465	  This option is needed for the systems that have more than 8 CPUs
466
467config X86_EXTENDED_PLATFORM
468	bool "Support for extended (non-PC) x86 platforms"
469	default y
470	---help---
471	  If you disable this option then the kernel will only support
472	  standard PC platforms. (which covers the vast majority of
473	  systems out there.)
474
475	  If you enable this option then you'll be able to select support
476	  for the following (non-PC) 32 bit x86 platforms:
477		Goldfish (Android emulator)
478		AMD Elan
479		RDC R-321x SoC
480		SGI 320/540 (Visual Workstation)
481		STA2X11-based (e.g. Northville)
482		Moorestown MID devices
483
484	  If you have one of these systems, or if you want to build a
485	  generic distribution kernel, say Y here - otherwise say N.
486endif
487
488if X86_64
489config X86_EXTENDED_PLATFORM
490	bool "Support for extended (non-PC) x86 platforms"
491	default y
492	---help---
493	  If you disable this option then the kernel will only support
494	  standard PC platforms. (which covers the vast majority of
495	  systems out there.)
496
497	  If you enable this option then you'll be able to select support
498	  for the following (non-PC) 64 bit x86 platforms:
499		Numascale NumaChip
500		ScaleMP vSMP
501		SGI Ultraviolet
502
503	  If you have one of these systems, or if you want to build a
504	  generic distribution kernel, say Y here - otherwise say N.
505endif
506# This is an alphabetically sorted list of 64 bit extended platforms
507# Please maintain the alphabetic order if and when there are additions
508config X86_NUMACHIP
509	bool "Numascale NumaChip"
510	depends on X86_64
511	depends on X86_EXTENDED_PLATFORM
512	depends on NUMA
513	depends on SMP
514	depends on X86_X2APIC
515	depends on PCI_MMCONFIG
516	---help---
517	  Adds support for Numascale NumaChip large-SMP systems. Needed to
518	  enable more than ~168 cores.
519	  If you don't have one of these, you should say N here.
520
521config X86_VSMP
522	bool "ScaleMP vSMP"
523	select HYPERVISOR_GUEST
524	select PARAVIRT
525	depends on X86_64 && PCI
526	depends on X86_EXTENDED_PLATFORM
527	depends on SMP
528	---help---
529	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
530	  supposed to run on these EM64T-based machines.  Only choose this option
531	  if you have one of these machines.
532
533config X86_UV
534	bool "SGI Ultraviolet"
535	depends on X86_64
536	depends on X86_EXTENDED_PLATFORM
537	depends on NUMA
538	depends on EFI
539	depends on X86_X2APIC
540	depends on PCI
541	---help---
542	  This option is needed in order to support SGI Ultraviolet systems.
543	  If you don't have one of these, you should say N here.
544
545# Following is an alphabetically sorted list of 32 bit extended platforms
546# Please maintain the alphabetic order if and when there are additions
547
548config X86_GOLDFISH
549       bool "Goldfish (Virtual Platform)"
550       depends on X86_EXTENDED_PLATFORM
551       ---help---
552	 Enable support for the Goldfish virtual platform used primarily
553	 for Android development. Unless you are building for the Android
554	 Goldfish emulator say N here.
555
556config X86_INTEL_CE
557	bool "CE4100 TV platform"
558	depends on PCI
559	depends on PCI_GODIRECT
560	depends on X86_IO_APIC
561	depends on X86_32
562	depends on X86_EXTENDED_PLATFORM
563	select X86_REBOOTFIXUPS
564	select OF
565	select OF_EARLY_FLATTREE
566	---help---
567	  Select for the Intel CE media processor (CE4100) SOC.
568	  This option compiles in support for the CE4100 SOC for settop
569	  boxes and media devices.
570
571config X86_INTEL_MID
572	bool "Intel MID platform support"
573	depends on X86_EXTENDED_PLATFORM
574	depends on X86_PLATFORM_DEVICES
575	depends on PCI
576	depends on X86_64 || (PCI_GOANY && X86_32)
577	depends on X86_IO_APIC
578	select SFI
579	select I2C
580	select DW_APB_TIMER
581	select APB_TIMER
582	select INTEL_SCU_IPC
583	select MFD_INTEL_MSIC
584	---help---
585	  Select to build a kernel capable of supporting Intel MID (Mobile
586	  Internet Device) platform systems which do not have the PCI legacy
587	  interfaces. If you are building for a PC class system say N here.
588
589	  Intel MID platforms are based on an Intel processor and chipset which
590	  consume less power than most of the x86 derivatives.
591
592config X86_INTEL_QUARK
593	bool "Intel Quark platform support"
594	depends on X86_32
595	depends on X86_EXTENDED_PLATFORM
596	depends on X86_PLATFORM_DEVICES
597	depends on X86_TSC
598	depends on PCI
599	depends on PCI_GOANY
600	depends on X86_IO_APIC
601	select IOSF_MBI
602	select INTEL_IMR
603	select COMMON_CLK
604	---help---
605	  Select to include support for Quark X1000 SoC.
606	  Say Y here if you have a Quark based system such as the Arduino
607	  compatible Intel Galileo.
608
609config X86_INTEL_LPSS
610	bool "Intel Low Power Subsystem Support"
611	depends on X86 && ACPI
612	select COMMON_CLK
613	select PINCTRL
614	select IOSF_MBI
615	---help---
616	  Select to build support for Intel Low Power Subsystem such as
617	  found on Intel Lynxpoint PCH. Selecting this option enables
618	  things like clock tree (common clock framework) and pincontrol
619	  which are needed by the LPSS peripheral drivers.
620
621config X86_AMD_PLATFORM_DEVICE
622	bool "AMD ACPI2Platform devices support"
623	depends on ACPI
624	select COMMON_CLK
625	select PINCTRL
626	---help---
627	  Select to interpret AMD specific ACPI device to platform device
628	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
629	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
630	  implemented under PINCTRL subsystem.
631
632config IOSF_MBI
633	tristate "Intel SoC IOSF Sideband support for SoC platforms"
634	depends on PCI
635	---help---
636	  This option enables sideband register access support for Intel SoC
637	  platforms. On these platforms the IOSF sideband is used in lieu of
638	  MSR's for some register accesses, mostly but not limited to thermal
639	  and power. Drivers may query the availability of this device to
640	  determine if they need the sideband in order to work on these
641	  platforms. The sideband is available on the following SoC products.
642	  This list is not meant to be exclusive.
643	   - BayTrail
644	   - Braswell
645	   - Quark
646
647	  You should say Y if you are running a kernel on one of these SoC's.
648
649config IOSF_MBI_DEBUG
650	bool "Enable IOSF sideband access through debugfs"
651	depends on IOSF_MBI && DEBUG_FS
652	---help---
653	  Select this option to expose the IOSF sideband access registers (MCR,
654	  MDR, MCRX) through debugfs to write and read register information from
655	  different units on the SoC. This is most useful for obtaining device
656	  state information for debug and analysis. As this is a general access
657	  mechanism, users of this option would have specific knowledge of the
658	  device they want to access.
659
660	  If you don't require the option or are in doubt, say N.
661
662config X86_RDC321X
663	bool "RDC R-321x SoC"
664	depends on X86_32
665	depends on X86_EXTENDED_PLATFORM
666	select M486
667	select X86_REBOOTFIXUPS
668	---help---
669	  This option is needed for RDC R-321x system-on-chip, also known
670	  as R-8610-(G).
671	  If you don't have one of these chips, you should say N here.
672
673config X86_32_NON_STANDARD
674	bool "Support non-standard 32-bit SMP architectures"
675	depends on X86_32 && SMP
676	depends on X86_EXTENDED_PLATFORM
677	---help---
678	  This option compiles in the bigsmp and STA2X11 default
679	  subarchitectures.  It is intended for a generic binary
680	  kernel. If you select them all, kernel will probe it one by
681	  one and will fallback to default.
682
683# Alphabetically sorted list of Non standard 32 bit platforms
684
685config X86_SUPPORTS_MEMORY_FAILURE
686	def_bool y
687	# MCE code calls memory_failure():
688	depends on X86_MCE
689	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
690	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
691	depends on X86_64 || !SPARSEMEM
692	select ARCH_SUPPORTS_MEMORY_FAILURE
693
694config STA2X11
695	bool "STA2X11 Companion Chip Support"
696	depends on X86_32_NON_STANDARD && PCI
697	select ARCH_HAS_PHYS_TO_DMA
698	select X86_DEV_DMA_OPS
699	select X86_DMA_REMAP
700	select SWIOTLB
701	select MFD_STA2X11
702	select GPIOLIB
703	default n
704	---help---
705	  This adds support for boards based on the STA2X11 IO-Hub,
706	  a.k.a. "ConneXt". The chip is used in place of the standard
707	  PC chipset, so all "standard" peripherals are missing. If this
708	  option is selected the kernel will still be able to boot on
709	  standard PC machines.
710
711config X86_32_IRIS
712	tristate "Eurobraille/Iris poweroff module"
713	depends on X86_32
714	---help---
715	  The Iris machines from EuroBraille do not have APM or ACPI support
716	  to shut themselves down properly.  A special I/O sequence is
717	  needed to do so, which is what this module does at
718	  kernel shutdown.
719
720	  This is only for Iris machines from EuroBraille.
721
722	  If unused, say N.
723
724config SCHED_OMIT_FRAME_POINTER
725	def_bool y
726	prompt "Single-depth WCHAN output"
727	depends on X86
728	---help---
729	  Calculate simpler /proc/<PID>/wchan values. If this option
730	  is disabled then wchan values will recurse back to the
731	  caller function. This provides more accurate wchan values,
732	  at the expense of slightly more scheduling overhead.
733
734	  If in doubt, say "Y".
735
736menuconfig HYPERVISOR_GUEST
737	bool "Linux guest support"
738	---help---
739	  Say Y here to enable options for running Linux under various hyper-
740	  visors. This option enables basic hypervisor detection and platform
741	  setup.
742
743	  If you say N, all options in this submenu will be skipped and
744	  disabled, and Linux guest support won't be built in.
745
746if HYPERVISOR_GUEST
747
748config PARAVIRT
749	bool "Enable paravirtualization code"
750	---help---
751	  This changes the kernel so it can modify itself when it is run
752	  under a hypervisor, potentially improving performance significantly
753	  over full virtualization.  However, when run without a hypervisor
754	  the kernel is theoretically slower and slightly larger.
755
756config PARAVIRT_DEBUG
757	bool "paravirt-ops debugging"
758	depends on PARAVIRT && DEBUG_KERNEL
759	---help---
760	  Enable to debug paravirt_ops internals.  Specifically, BUG if
761	  a paravirt_op is missing when it is called.
762
763config PARAVIRT_SPINLOCKS
764	bool "Paravirtualization layer for spinlocks"
765	depends on PARAVIRT && SMP
766	---help---
767	  Paravirtualized spinlocks allow a pvops backend to replace the
768	  spinlock implementation with something virtualization-friendly
769	  (for example, block the virtual CPU rather than spinning).
770
771	  It has a minimal impact on native kernels and gives a nice performance
772	  benefit on paravirtualized KVM / Xen kernels.
773
774	  If you are unsure how to answer this question, answer Y.
775
776config QUEUED_LOCK_STAT
777	bool "Paravirt queued spinlock statistics"
778	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
779	---help---
780	  Enable the collection of statistical data on the slowpath
781	  behavior of paravirtualized queued spinlocks and report
782	  them on debugfs.
783
784source "arch/x86/xen/Kconfig"
785
786config KVM_GUEST
787	bool "KVM Guest support (including kvmclock)"
788	depends on PARAVIRT
789	select PARAVIRT_CLOCK
790	default y
791	---help---
792	  This option enables various optimizations for running under the KVM
793	  hypervisor. It includes a paravirtualized clock, so that instead
794	  of relying on a PIT (or probably other) emulation by the
795	  underlying device model, the host provides the guest with
796	  timing infrastructure such as time of day, and system time
797
798config KVM_DEBUG_FS
799	bool "Enable debug information for KVM Guests in debugfs"
800	depends on KVM_GUEST && DEBUG_FS
801	default n
802	---help---
803	  This option enables collection of various statistics for KVM guest.
804	  Statistics are displayed in debugfs filesystem. Enabling this option
805	  may incur significant overhead.
806
807config PARAVIRT_TIME_ACCOUNTING
808	bool "Paravirtual steal time accounting"
809	depends on PARAVIRT
810	default n
811	---help---
812	  Select this option to enable fine granularity task steal time
813	  accounting. Time spent executing other tasks in parallel with
814	  the current vCPU is discounted from the vCPU power. To account for
815	  that, there can be a small performance impact.
816
817	  If in doubt, say N here.
818
819config PARAVIRT_CLOCK
820	bool
821
822config JAILHOUSE_GUEST
823	bool "Jailhouse non-root cell support"
824	depends on X86_64 && PCI
825	select X86_PM_TIMER
826	---help---
827	  This option allows to run Linux as guest in a Jailhouse non-root
828	  cell. You can leave this option disabled if you only want to start
829	  Jailhouse and run Linux afterwards in the root cell.
830
831endif #HYPERVISOR_GUEST
832
833config NO_BOOTMEM
834	def_bool y
835
836source "arch/x86/Kconfig.cpu"
837
838config HPET_TIMER
839	def_bool X86_64
840	prompt "HPET Timer Support" if X86_32
841	---help---
842	  Use the IA-PC HPET (High Precision Event Timer) to manage
843	  time in preference to the PIT and RTC, if a HPET is
844	  present.
845	  HPET is the next generation timer replacing legacy 8254s.
846	  The HPET provides a stable time base on SMP
847	  systems, unlike the TSC, but it is more expensive to access,
848	  as it is off-chip.  The interface used is documented
849	  in the HPET spec, revision 1.
850
851	  You can safely choose Y here.  However, HPET will only be
852	  activated if the platform and the BIOS support this feature.
853	  Otherwise the 8254 will be used for timing services.
854
855	  Choose N to continue using the legacy 8254 timer.
856
857config HPET_EMULATE_RTC
858	def_bool y
859	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
860
861config APB_TIMER
862       def_bool y if X86_INTEL_MID
863       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
864       select DW_APB_TIMER
865       depends on X86_INTEL_MID && SFI
866       help
867         APB timer is the replacement for 8254, HPET on X86 MID platforms.
868         The APBT provides a stable time base on SMP
869         systems, unlike the TSC, but it is more expensive to access,
870         as it is off-chip. APB timers are always running regardless of CPU
871         C states, they are used as per CPU clockevent device when possible.
872
873# Mark as expert because too many people got it wrong.
874# The code disables itself when not needed.
875config DMI
876	default y
877	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
878	bool "Enable DMI scanning" if EXPERT
879	---help---
880	  Enabled scanning of DMI to identify machine quirks. Say Y
881	  here unless you have verified that your setup is not
882	  affected by entries in the DMI blacklist. Required by PNP
883	  BIOS code.
884
885config GART_IOMMU
886	bool "Old AMD GART IOMMU support"
887	select IOMMU_HELPER
888	select SWIOTLB
889	depends on X86_64 && PCI && AMD_NB
890	---help---
891	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
892	  GART based hardware IOMMUs.
893
894	  The GART supports full DMA access for devices with 32-bit access
895	  limitations, on systems with more than 3 GB. This is usually needed
896	  for USB, sound, many IDE/SATA chipsets and some other devices.
897
898	  Newer systems typically have a modern AMD IOMMU, supported via
899	  the CONFIG_AMD_IOMMU=y config option.
900
901	  In normal configurations this driver is only active when needed:
902	  there's more than 3 GB of memory and the system contains a
903	  32-bit limited device.
904
905	  If unsure, say Y.
906
907config CALGARY_IOMMU
908	bool "IBM Calgary IOMMU support"
909	select IOMMU_HELPER
910	select SWIOTLB
911	depends on X86_64 && PCI
912	---help---
913	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
914	  systems. Needed to run systems with more than 3GB of memory
915	  properly with 32-bit PCI devices that do not support DAC
916	  (Double Address Cycle). Calgary also supports bus level
917	  isolation, where all DMAs pass through the IOMMU.  This
918	  prevents them from going anywhere except their intended
919	  destination. This catches hard-to-find kernel bugs and
920	  mis-behaving drivers and devices that do not use the DMA-API
921	  properly to set up their DMA buffers.  The IOMMU can be
922	  turned off at boot time with the iommu=off parameter.
923	  Normally the kernel will make the right choice by itself.
924	  If unsure, say Y.
925
926config CALGARY_IOMMU_ENABLED_BY_DEFAULT
927	def_bool y
928	prompt "Should Calgary be enabled by default?"
929	depends on CALGARY_IOMMU
930	---help---
931	  Should Calgary be enabled by default? if you choose 'y', Calgary
932	  will be used (if it exists). If you choose 'n', Calgary will not be
933	  used even if it exists. If you choose 'n' and would like to use
934	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
935	  If unsure, say Y.
936
937config MAXSMP
938	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
939	depends on X86_64 && SMP && DEBUG_KERNEL
940	select CPUMASK_OFFSTACK
941	---help---
942	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
943	  If unsure, say N.
944
945#
946# The maximum number of CPUs supported:
947#
948# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
949# and which can be configured interactively in the
950# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
951#
952# The ranges are different on 32-bit and 64-bit kernels, depending on
953# hardware capabilities and scalability features of the kernel.
954#
955# ( If MAXSMP is enabled we just use the highest possible value and disable
956#   interactive configuration. )
957#
958
959config NR_CPUS_RANGE_BEGIN
960	int
961	default NR_CPUS_RANGE_END if MAXSMP
962	default    1 if !SMP
963	default    2
964
965config NR_CPUS_RANGE_END
966	int
967	depends on X86_32
968	default   64 if  SMP &&  X86_BIGSMP
969	default    8 if  SMP && !X86_BIGSMP
970	default    1 if !SMP
971
972config NR_CPUS_RANGE_END
973	int
974	depends on X86_64
975	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
976	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
977	default    1 if !SMP
978
979config NR_CPUS_DEFAULT
980	int
981	depends on X86_32
982	default   32 if  X86_BIGSMP
983	default    8 if  SMP
984	default    1 if !SMP
985
986config NR_CPUS_DEFAULT
987	int
988	depends on X86_64
989	default 8192 if  MAXSMP
990	default   64 if  SMP
991	default    1 if !SMP
992
993config NR_CPUS
994	int "Maximum number of CPUs" if SMP && !MAXSMP
995	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
996	default NR_CPUS_DEFAULT
997	---help---
998	  This allows you to specify the maximum number of CPUs which this
999	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1000	  supported value is 8192, otherwise the maximum value is 512.  The
1001	  minimum value which makes sense is 2.
1002
1003	  This is purely to save memory: each supported CPU adds about 8KB
1004	  to the kernel image.
1005
1006config SCHED_SMT
1007	bool "SMT (Hyperthreading) scheduler support"
1008	depends on SMP
1009	---help---
1010	  SMT scheduler support improves the CPU scheduler's decision making
1011	  when dealing with Intel Pentium 4 chips with HyperThreading at a
1012	  cost of slightly increased overhead in some places. If unsure say
1013	  N here.
1014
1015config SCHED_MC
1016	def_bool y
1017	prompt "Multi-core scheduler support"
1018	depends on SMP
1019	---help---
1020	  Multi-core scheduler support improves the CPU scheduler's decision
1021	  making when dealing with multi-core CPU chips at a cost of slightly
1022	  increased overhead in some places. If unsure say N here.
1023
1024config SCHED_MC_PRIO
1025	bool "CPU core priorities scheduler support"
1026	depends on SCHED_MC && CPU_SUP_INTEL
1027	select X86_INTEL_PSTATE
1028	select CPU_FREQ
1029	default y
1030	---help---
1031	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1032	  core ordering determined at manufacturing time, which allows
1033	  certain cores to reach higher turbo frequencies (when running
1034	  single threaded workloads) than others.
1035
1036	  Enabling this kernel feature teaches the scheduler about
1037	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1038	  scheduler's CPU selection logic accordingly, so that higher
1039	  overall system performance can be achieved.
1040
1041	  This feature will have no effect on CPUs without this feature.
1042
1043	  If unsure say Y here.
1044
1045config UP_LATE_INIT
1046       def_bool y
1047       depends on !SMP && X86_LOCAL_APIC
1048
1049config X86_UP_APIC
1050	bool "Local APIC support on uniprocessors" if !PCI_MSI
1051	default PCI_MSI
1052	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1053	---help---
1054	  A local APIC (Advanced Programmable Interrupt Controller) is an
1055	  integrated interrupt controller in the CPU. If you have a single-CPU
1056	  system which has a processor with a local APIC, you can say Y here to
1057	  enable and use it. If you say Y here even though your machine doesn't
1058	  have a local APIC, then the kernel will still run with no slowdown at
1059	  all. The local APIC supports CPU-generated self-interrupts (timer,
1060	  performance counters), and the NMI watchdog which detects hard
1061	  lockups.
1062
1063config X86_UP_IOAPIC
1064	bool "IO-APIC support on uniprocessors"
1065	depends on X86_UP_APIC
1066	---help---
1067	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1068	  SMP-capable replacement for PC-style interrupt controllers. Most
1069	  SMP systems and many recent uniprocessor systems have one.
1070
1071	  If you have a single-CPU system with an IO-APIC, you can say Y here
1072	  to use it. If you say Y here even though your machine doesn't have
1073	  an IO-APIC, then the kernel will still run with no slowdown at all.
1074
1075config X86_LOCAL_APIC
1076	def_bool y
1077	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1078	select IRQ_DOMAIN_HIERARCHY
1079	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1080
1081config X86_IO_APIC
1082	def_bool y
1083	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1084
1085config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1086	bool "Reroute for broken boot IRQs"
1087	depends on X86_IO_APIC
1088	---help---
1089	  This option enables a workaround that fixes a source of
1090	  spurious interrupts. This is recommended when threaded
1091	  interrupt handling is used on systems where the generation of
1092	  superfluous "boot interrupts" cannot be disabled.
1093
1094	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1095	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1096	  kernel does during interrupt handling). On chipsets where this
1097	  boot IRQ generation cannot be disabled, this workaround keeps
1098	  the original IRQ line masked so that only the equivalent "boot
1099	  IRQ" is delivered to the CPUs. The workaround also tells the
1100	  kernel to set up the IRQ handler on the boot IRQ line. In this
1101	  way only one interrupt is delivered to the kernel. Otherwise
1102	  the spurious second interrupt may cause the kernel to bring
1103	  down (vital) interrupt lines.
1104
1105	  Only affects "broken" chipsets. Interrupt sharing may be
1106	  increased on these systems.
1107
1108config X86_MCE
1109	bool "Machine Check / overheating reporting"
1110	select GENERIC_ALLOCATOR
1111	default y
1112	---help---
1113	  Machine Check support allows the processor to notify the
1114	  kernel if it detects a problem (e.g. overheating, data corruption).
1115	  The action the kernel takes depends on the severity of the problem,
1116	  ranging from warning messages to halting the machine.
1117
1118config X86_MCELOG_LEGACY
1119	bool "Support for deprecated /dev/mcelog character device"
1120	depends on X86_MCE
1121	---help---
1122	  Enable support for /dev/mcelog which is needed by the old mcelog
1123	  userspace logging daemon. Consider switching to the new generation
1124	  rasdaemon solution.
1125
1126config X86_MCE_INTEL
1127	def_bool y
1128	prompt "Intel MCE features"
1129	depends on X86_MCE && X86_LOCAL_APIC
1130	---help---
1131	   Additional support for intel specific MCE features such as
1132	   the thermal monitor.
1133
1134config X86_MCE_AMD
1135	def_bool y
1136	prompt "AMD MCE features"
1137	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1138	---help---
1139	   Additional support for AMD specific MCE features such as
1140	   the DRAM Error Threshold.
1141
1142config X86_ANCIENT_MCE
1143	bool "Support for old Pentium 5 / WinChip machine checks"
1144	depends on X86_32 && X86_MCE
1145	---help---
1146	  Include support for machine check handling on old Pentium 5 or WinChip
1147	  systems. These typically need to be enabled explicitly on the command
1148	  line.
1149
1150config X86_MCE_THRESHOLD
1151	depends on X86_MCE_AMD || X86_MCE_INTEL
1152	def_bool y
1153
1154config X86_MCE_INJECT
1155	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1156	tristate "Machine check injector support"
1157	---help---
1158	  Provide support for injecting machine checks for testing purposes.
1159	  If you don't know what a machine check is and you don't do kernel
1160	  QA it is safe to say n.
1161
1162config X86_THERMAL_VECTOR
1163	def_bool y
1164	depends on X86_MCE_INTEL
1165
1166source "arch/x86/events/Kconfig"
1167
1168config X86_LEGACY_VM86
1169	bool "Legacy VM86 support"
1170	default n
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 ARCH_HAS_MEM_ENCRYPT
1494	def_bool y
1495
1496config AMD_MEM_ENCRYPT
1497	bool "AMD Secure Memory Encryption (SME) support"
1498	depends on X86_64 && CPU_SUP_AMD
1499	select DYNAMIC_PHYSICAL_MASK
1500	---help---
1501	  Say yes to enable support for the encryption of system memory.
1502	  This requires an AMD processor that supports Secure Memory
1503	  Encryption (SME).
1504
1505config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1506	bool "Activate AMD Secure Memory Encryption (SME) by default"
1507	default y
1508	depends on AMD_MEM_ENCRYPT
1509	---help---
1510	  Say yes to have system memory encrypted by default if running on
1511	  an AMD processor that supports Secure Memory Encryption (SME).
1512
1513	  If set to Y, then the encryption of system memory can be
1514	  deactivated with the mem_encrypt=off command line option.
1515
1516	  If set to N, then the encryption of system memory can be
1517	  activated with the mem_encrypt=on command line option.
1518
1519config ARCH_USE_MEMREMAP_PROT
1520	def_bool y
1521	depends on AMD_MEM_ENCRYPT
1522
1523# Common NUMA Features
1524config NUMA
1525	bool "Numa Memory Allocation and Scheduler Support"
1526	depends on SMP
1527	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1528	default y if X86_BIGSMP
1529	---help---
1530	  Enable NUMA (Non Uniform Memory Access) support.
1531
1532	  The kernel will try to allocate memory used by a CPU on the
1533	  local memory controller of the CPU and add some more
1534	  NUMA awareness to the kernel.
1535
1536	  For 64-bit this is recommended if the system is Intel Core i7
1537	  (or later), AMD Opteron, or EM64T NUMA.
1538
1539	  For 32-bit this is only needed if you boot a 32-bit
1540	  kernel on a 64-bit NUMA platform.
1541
1542	  Otherwise, you should say N.
1543
1544config AMD_NUMA
1545	def_bool y
1546	prompt "Old style AMD Opteron NUMA detection"
1547	depends on X86_64 && NUMA && PCI
1548	---help---
1549	  Enable AMD NUMA node topology detection.  You should say Y here if
1550	  you have a multi processor AMD system. This uses an old method to
1551	  read the NUMA configuration directly from the builtin Northbridge
1552	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1553	  which also takes priority if both are compiled in.
1554
1555config X86_64_ACPI_NUMA
1556	def_bool y
1557	prompt "ACPI NUMA detection"
1558	depends on X86_64 && NUMA && ACPI && PCI
1559	select ACPI_NUMA
1560	---help---
1561	  Enable ACPI SRAT based node topology detection.
1562
1563# Some NUMA nodes have memory ranges that span
1564# other nodes.  Even though a pfn is valid and
1565# between a node's start and end pfns, it may not
1566# reside on that node.  See memmap_init_zone()
1567# for details.
1568config NODES_SPAN_OTHER_NODES
1569	def_bool y
1570	depends on X86_64_ACPI_NUMA
1571
1572config NUMA_EMU
1573	bool "NUMA emulation"
1574	depends on NUMA
1575	---help---
1576	  Enable NUMA emulation. A flat machine will be split
1577	  into virtual nodes when booted with "numa=fake=N", where N is the
1578	  number of nodes. This is only useful for debugging.
1579
1580config NODES_SHIFT
1581	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1582	range 1 10
1583	default "10" if MAXSMP
1584	default "6" if X86_64
1585	default "3"
1586	depends on NEED_MULTIPLE_NODES
1587	---help---
1588	  Specify the maximum number of NUMA Nodes available on the target
1589	  system.  Increases memory reserved to accommodate various tables.
1590
1591config ARCH_HAVE_MEMORY_PRESENT
1592	def_bool y
1593	depends on X86_32 && DISCONTIGMEM
1594
1595config ARCH_FLATMEM_ENABLE
1596	def_bool y
1597	depends on X86_32 && !NUMA
1598
1599config ARCH_DISCONTIGMEM_ENABLE
1600	def_bool y
1601	depends on NUMA && X86_32
1602
1603config ARCH_DISCONTIGMEM_DEFAULT
1604	def_bool y
1605	depends on NUMA && X86_32
1606
1607config ARCH_SPARSEMEM_ENABLE
1608	def_bool y
1609	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1610	select SPARSEMEM_STATIC if X86_32
1611	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1612
1613config ARCH_SPARSEMEM_DEFAULT
1614	def_bool y
1615	depends on X86_64
1616
1617config ARCH_SELECT_MEMORY_MODEL
1618	def_bool y
1619	depends on ARCH_SPARSEMEM_ENABLE
1620
1621config ARCH_MEMORY_PROBE
1622	bool "Enable sysfs memory/probe interface"
1623	depends on X86_64 && MEMORY_HOTPLUG
1624	help
1625	  This option enables a sysfs memory/probe interface for testing.
1626	  See Documentation/memory-hotplug.txt for more information.
1627	  If you are unsure how to answer this question, answer N.
1628
1629config ARCH_PROC_KCORE_TEXT
1630	def_bool y
1631	depends on X86_64 && PROC_KCORE
1632
1633config ILLEGAL_POINTER_VALUE
1634       hex
1635       default 0 if X86_32
1636       default 0xdead000000000000 if X86_64
1637
1638config X86_PMEM_LEGACY_DEVICE
1639	bool
1640
1641config X86_PMEM_LEGACY
1642	tristate "Support non-standard NVDIMMs and ADR protected memory"
1643	depends on PHYS_ADDR_T_64BIT
1644	depends on BLK_DEV
1645	select X86_PMEM_LEGACY_DEVICE
1646	select LIBNVDIMM
1647	help
1648	  Treat memory marked using the non-standard e820 type of 12 as used
1649	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1650	  The kernel will offer these regions to the 'pmem' driver so
1651	  they can be used for persistent storage.
1652
1653	  Say Y if unsure.
1654
1655config HIGHPTE
1656	bool "Allocate 3rd-level pagetables from highmem"
1657	depends on HIGHMEM
1658	---help---
1659	  The VM uses one page table entry for each page of physical memory.
1660	  For systems with a lot of RAM, this can be wasteful of precious
1661	  low memory.  Setting this option will put user-space page table
1662	  entries in high memory.
1663
1664config X86_CHECK_BIOS_CORRUPTION
1665	bool "Check for low memory corruption"
1666	---help---
1667	  Periodically check for memory corruption in low memory, which
1668	  is suspected to be caused by BIOS.  Even when enabled in the
1669	  configuration, it is disabled at runtime.  Enable it by
1670	  setting "memory_corruption_check=1" on the kernel command
1671	  line.  By default it scans the low 64k of memory every 60
1672	  seconds; see the memory_corruption_check_size and
1673	  memory_corruption_check_period parameters in
1674	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1675
1676	  When enabled with the default parameters, this option has
1677	  almost no overhead, as it reserves a relatively small amount
1678	  of memory and scans it infrequently.  It both detects corruption
1679	  and prevents it from affecting the running system.
1680
1681	  It is, however, intended as a diagnostic tool; if repeatable
1682	  BIOS-originated corruption always affects the same memory,
1683	  you can use memmap= to prevent the kernel from using that
1684	  memory.
1685
1686config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1687	bool "Set the default setting of memory_corruption_check"
1688	depends on X86_CHECK_BIOS_CORRUPTION
1689	default y
1690	---help---
1691	  Set whether the default state of memory_corruption_check is
1692	  on or off.
1693
1694config X86_RESERVE_LOW
1695	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1696	default 64
1697	range 4 640
1698	---help---
1699	  Specify the amount of low memory to reserve for the BIOS.
1700
1701	  The first page contains BIOS data structures that the kernel
1702	  must not use, so that page must always be reserved.
1703
1704	  By default we reserve the first 64K of physical RAM, as a
1705	  number of BIOSes are known to corrupt that memory range
1706	  during events such as suspend/resume or monitor cable
1707	  insertion, so it must not be used by the kernel.
1708
1709	  You can set this to 4 if you are absolutely sure that you
1710	  trust the BIOS to get all its memory reservations and usages
1711	  right.  If you know your BIOS have problems beyond the
1712	  default 64K area, you can set this to 640 to avoid using the
1713	  entire low memory range.
1714
1715	  If you have doubts about the BIOS (e.g. suspend/resume does
1716	  not work or there's kernel crashes after certain hardware
1717	  hotplug events) then you might want to enable
1718	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1719	  typical corruption patterns.
1720
1721	  Leave this to the default value of 64 if you are unsure.
1722
1723config MATH_EMULATION
1724	bool
1725	depends on MODIFY_LDT_SYSCALL
1726	prompt "Math emulation" if X86_32
1727	---help---
1728	  Linux can emulate a math coprocessor (used for floating point
1729	  operations) if you don't have one. 486DX and Pentium processors have
1730	  a math coprocessor built in, 486SX and 386 do not, unless you added
1731	  a 487DX or 387, respectively. (The messages during boot time can
1732	  give you some hints here ["man dmesg"].) Everyone needs either a
1733	  coprocessor or this emulation.
1734
1735	  If you don't have a math coprocessor, you need to say Y here; if you
1736	  say Y here even though you have a coprocessor, the coprocessor will
1737	  be used nevertheless. (This behavior can be changed with the kernel
1738	  command line option "no387", which comes handy if your coprocessor
1739	  is broken. Try "man bootparam" or see the documentation of your boot
1740	  loader (lilo or loadlin) about how to pass options to the kernel at
1741	  boot time.) This means that it is a good idea to say Y here if you
1742	  intend to use this kernel on different machines.
1743
1744	  More information about the internals of the Linux math coprocessor
1745	  emulation can be found in <file:arch/x86/math-emu/README>.
1746
1747	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1748	  kernel, it won't hurt.
1749
1750config MTRR
1751	def_bool y
1752	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1753	---help---
1754	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1755	  the Memory Type Range Registers (MTRRs) may be used to control
1756	  processor access to memory ranges. This is most useful if you have
1757	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1758	  allows bus write transfers to be combined into a larger transfer
1759	  before bursting over the PCI/AGP bus. This can increase performance
1760	  of image write operations 2.5 times or more. Saying Y here creates a
1761	  /proc/mtrr file which may be used to manipulate your processor's
1762	  MTRRs. Typically the X server should use this.
1763
1764	  This code has a reasonably generic interface so that similar
1765	  control registers on other processors can be easily supported
1766	  as well:
1767
1768	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1769	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1770	  these, the ARRs are used to emulate the MTRRs.
1771	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1772	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1773	  write-combining. All of these processors are supported by this code
1774	  and it makes sense to say Y here if you have one of them.
1775
1776	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1777	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1778	  can lead to all sorts of problems, so it's good to say Y here.
1779
1780	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1781	  just add about 9 KB to your kernel.
1782
1783	  See <file:Documentation/x86/mtrr.txt> for more information.
1784
1785config MTRR_SANITIZER
1786	def_bool y
1787	prompt "MTRR cleanup support"
1788	depends on MTRR
1789	---help---
1790	  Convert MTRR layout from continuous to discrete, so X drivers can
1791	  add writeback entries.
1792
1793	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1794	  The largest mtrr entry size for a continuous block can be set with
1795	  mtrr_chunk_size.
1796
1797	  If unsure, say Y.
1798
1799config MTRR_SANITIZER_ENABLE_DEFAULT
1800	int "MTRR cleanup enable value (0-1)"
1801	range 0 1
1802	default "0"
1803	depends on MTRR_SANITIZER
1804	---help---
1805	  Enable mtrr cleanup default value
1806
1807config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1808	int "MTRR cleanup spare reg num (0-7)"
1809	range 0 7
1810	default "1"
1811	depends on MTRR_SANITIZER
1812	---help---
1813	  mtrr cleanup spare entries default, it can be changed via
1814	  mtrr_spare_reg_nr=N on the kernel command line.
1815
1816config X86_PAT
1817	def_bool y
1818	prompt "x86 PAT support" if EXPERT
1819	depends on MTRR
1820	---help---
1821	  Use PAT attributes to setup page level cache control.
1822
1823	  PATs are the modern equivalents of MTRRs and are much more
1824	  flexible than MTRRs.
1825
1826	  Say N here if you see bootup problems (boot crash, boot hang,
1827	  spontaneous reboots) or a non-working video driver.
1828
1829	  If unsure, say Y.
1830
1831config ARCH_USES_PG_UNCACHED
1832	def_bool y
1833	depends on X86_PAT
1834
1835config ARCH_RANDOM
1836	def_bool y
1837	prompt "x86 architectural random number generator" if EXPERT
1838	---help---
1839	  Enable the x86 architectural RDRAND instruction
1840	  (Intel Bull Mountain technology) to generate random numbers.
1841	  If supported, this is a high bandwidth, cryptographically
1842	  secure hardware random number generator.
1843
1844config X86_SMAP
1845	def_bool y
1846	prompt "Supervisor Mode Access Prevention" if EXPERT
1847	---help---
1848	  Supervisor Mode Access Prevention (SMAP) is a security
1849	  feature in newer Intel processors.  There is a small
1850	  performance cost if this enabled and turned on; there is
1851	  also a small increase in the kernel size if this is enabled.
1852
1853	  If unsure, say Y.
1854
1855config X86_INTEL_UMIP
1856	def_bool y
1857	depends on CPU_SUP_INTEL
1858	prompt "Intel User Mode Instruction Prevention" if EXPERT
1859	---help---
1860	  The User Mode Instruction Prevention (UMIP) is a security
1861	  feature in newer Intel processors. If enabled, a general
1862	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1863	  or STR instructions are executed in user mode. These instructions
1864	  unnecessarily expose information about the hardware state.
1865
1866	  The vast majority of applications do not use these instructions.
1867	  For the very few that do, software emulation is provided in
1868	  specific cases in protected and virtual-8086 modes. Emulated
1869	  results are dummy.
1870
1871config X86_INTEL_MPX
1872	prompt "Intel MPX (Memory Protection Extensions)"
1873	def_bool n
1874	# Note: only available in 64-bit mode due to VMA flags shortage
1875	depends on CPU_SUP_INTEL && X86_64
1876	select ARCH_USES_HIGH_VMA_FLAGS
1877	---help---
1878	  MPX provides hardware features that can be used in
1879	  conjunction with compiler-instrumented code to check
1880	  memory references.  It is designed to detect buffer
1881	  overflow or underflow bugs.
1882
1883	  This option enables running applications which are
1884	  instrumented or otherwise use MPX.  It does not use MPX
1885	  itself inside the kernel or to protect the kernel
1886	  against bad memory references.
1887
1888	  Enabling this option will make the kernel larger:
1889	  ~8k of kernel text and 36 bytes of data on a 64-bit
1890	  defconfig.  It adds a long to the 'mm_struct' which
1891	  will increase the kernel memory overhead of each
1892	  process and adds some branches to paths used during
1893	  exec() and munmap().
1894
1895	  For details, see Documentation/x86/intel_mpx.txt
1896
1897	  If unsure, say N.
1898
1899config X86_INTEL_MEMORY_PROTECTION_KEYS
1900	prompt "Intel Memory Protection Keys"
1901	def_bool y
1902	# Note: only available in 64-bit mode
1903	depends on CPU_SUP_INTEL && X86_64
1904	select ARCH_USES_HIGH_VMA_FLAGS
1905	select ARCH_HAS_PKEYS
1906	---help---
1907	  Memory Protection Keys provides a mechanism for enforcing
1908	  page-based protections, but without requiring modification of the
1909	  page tables when an application changes protection domains.
1910
1911	  For details, see Documentation/x86/protection-keys.txt
1912
1913	  If unsure, say y.
1914
1915config EFI
1916	bool "EFI runtime service support"
1917	depends on ACPI
1918	select UCS2_STRING
1919	select EFI_RUNTIME_WRAPPERS
1920	---help---
1921	  This enables the kernel to use EFI runtime services that are
1922	  available (such as the EFI variable services).
1923
1924	  This option is only useful on systems that have EFI firmware.
1925	  In addition, you should use the latest ELILO loader available
1926	  at <http://elilo.sourceforge.net> in order to take advantage
1927	  of EFI runtime services. However, even with this option, the
1928	  resultant kernel should continue to boot on existing non-EFI
1929	  platforms.
1930
1931config EFI_STUB
1932       bool "EFI stub support"
1933       depends on EFI && !X86_USE_3DNOW
1934       select RELOCATABLE
1935       ---help---
1936          This kernel feature allows a bzImage to be loaded directly
1937	  by EFI firmware without the use of a bootloader.
1938
1939	  See Documentation/efi-stub.txt for more information.
1940
1941config EFI_MIXED
1942	bool "EFI mixed-mode support"
1943	depends on EFI_STUB && X86_64
1944	---help---
1945	   Enabling this feature allows a 64-bit kernel to be booted
1946	   on a 32-bit firmware, provided that your CPU supports 64-bit
1947	   mode.
1948
1949	   Note that it is not possible to boot a mixed-mode enabled
1950	   kernel via the EFI boot stub - a bootloader that supports
1951	   the EFI handover protocol must be used.
1952
1953	   If unsure, say N.
1954
1955config SECCOMP
1956	def_bool y
1957	prompt "Enable seccomp to safely compute untrusted bytecode"
1958	---help---
1959	  This kernel feature is useful for number crunching applications
1960	  that may need to compute untrusted bytecode during their
1961	  execution. By using pipes or other transports made available to
1962	  the process as file descriptors supporting the read/write
1963	  syscalls, it's possible to isolate those applications in
1964	  their own address space using seccomp. Once seccomp is
1965	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1966	  and the task is only allowed to execute a few safe syscalls
1967	  defined by each seccomp mode.
1968
1969	  If unsure, say Y. Only embedded should say N here.
1970
1971source kernel/Kconfig.hz
1972
1973config KEXEC
1974	bool "kexec system call"
1975	select KEXEC_CORE
1976	---help---
1977	  kexec is a system call that implements the ability to shutdown your
1978	  current kernel, and to start another kernel.  It is like a reboot
1979	  but it is independent of the system firmware.   And like a reboot
1980	  you can start any kernel with it, not just Linux.
1981
1982	  The name comes from the similarity to the exec system call.
1983
1984	  It is an ongoing process to be certain the hardware in a machine
1985	  is properly shutdown, so do not be surprised if this code does not
1986	  initially work for you.  As of this writing the exact hardware
1987	  interface is strongly in flux, so no good recommendation can be
1988	  made.
1989
1990config KEXEC_FILE
1991	bool "kexec file based system call"
1992	select KEXEC_CORE
1993	select BUILD_BIN2C
1994	depends on X86_64
1995	depends on CRYPTO=y
1996	depends on CRYPTO_SHA256=y
1997	---help---
1998	  This is new version of kexec system call. This system call is
1999	  file based and takes file descriptors as system call argument
2000	  for kernel and initramfs as opposed to list of segments as
2001	  accepted by previous system call.
2002
2003config ARCH_HAS_KEXEC_PURGATORY
2004	def_bool KEXEC_FILE
2005
2006config KEXEC_VERIFY_SIG
2007	bool "Verify kernel signature during kexec_file_load() syscall"
2008	depends on KEXEC_FILE
2009	---help---
2010	  This option makes kernel signature verification mandatory for
2011	  the kexec_file_load() syscall.
2012
2013	  In addition to that option, you need to enable signature
2014	  verification for the corresponding kernel image type being
2015	  loaded in order for this to work.
2016
2017config KEXEC_BZIMAGE_VERIFY_SIG
2018	bool "Enable bzImage signature verification support"
2019	depends on KEXEC_VERIFY_SIG
2020	depends on SIGNED_PE_FILE_VERIFICATION
2021	select SYSTEM_TRUSTED_KEYRING
2022	---help---
2023	  Enable bzImage signature verification support.
2024
2025config CRASH_DUMP
2026	bool "kernel crash dumps"
2027	depends on X86_64 || (X86_32 && HIGHMEM)
2028	---help---
2029	  Generate crash dump after being started by kexec.
2030	  This should be normally only set in special crash dump kernels
2031	  which are loaded in the main kernel with kexec-tools into
2032	  a specially reserved region and then later executed after
2033	  a crash by kdump/kexec. The crash dump kernel must be compiled
2034	  to a memory address not used by the main kernel or BIOS using
2035	  PHYSICAL_START, or it must be built as a relocatable image
2036	  (CONFIG_RELOCATABLE=y).
2037	  For more details see Documentation/kdump/kdump.txt
2038
2039config KEXEC_JUMP
2040	bool "kexec jump"
2041	depends on KEXEC && HIBERNATION
2042	---help---
2043	  Jump between original kernel and kexeced kernel and invoke
2044	  code in physical address mode via KEXEC
2045
2046config PHYSICAL_START
2047	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2048	default "0x1000000"
2049	---help---
2050	  This gives the physical address where the kernel is loaded.
2051
2052	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2053	  bzImage will decompress itself to above physical address and
2054	  run from there. Otherwise, bzImage will run from the address where
2055	  it has been loaded by the boot loader and will ignore above physical
2056	  address.
2057
2058	  In normal kdump cases one does not have to set/change this option
2059	  as now bzImage can be compiled as a completely relocatable image
2060	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2061	  address. This option is mainly useful for the folks who don't want
2062	  to use a bzImage for capturing the crash dump and want to use a
2063	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2064	  to be specifically compiled to run from a specific memory area
2065	  (normally a reserved region) and this option comes handy.
2066
2067	  So if you are using bzImage for capturing the crash dump,
2068	  leave the value here unchanged to 0x1000000 and set
2069	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2070	  for capturing the crash dump change this value to start of
2071	  the reserved region.  In other words, it can be set based on
2072	  the "X" value as specified in the "crashkernel=YM@XM"
2073	  command line boot parameter passed to the panic-ed
2074	  kernel. Please take a look at Documentation/kdump/kdump.txt
2075	  for more details about crash dumps.
2076
2077	  Usage of bzImage for capturing the crash dump is recommended as
2078	  one does not have to build two kernels. Same kernel can be used
2079	  as production kernel and capture kernel. Above option should have
2080	  gone away after relocatable bzImage support is introduced. But it
2081	  is present because there are users out there who continue to use
2082	  vmlinux for dump capture. This option should go away down the
2083	  line.
2084
2085	  Don't change this unless you know what you are doing.
2086
2087config RELOCATABLE
2088	bool "Build a relocatable kernel"
2089	default y
2090	---help---
2091	  This builds a kernel image that retains relocation information
2092	  so it can be loaded someplace besides the default 1MB.
2093	  The relocations tend to make the kernel binary about 10% larger,
2094	  but are discarded at runtime.
2095
2096	  One use is for the kexec on panic case where the recovery kernel
2097	  must live at a different physical address than the primary
2098	  kernel.
2099
2100	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2101	  it has been loaded at and the compile time physical address
2102	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2103
2104config RANDOMIZE_BASE
2105	bool "Randomize the address of the kernel image (KASLR)"
2106	depends on RELOCATABLE
2107	default y
2108	---help---
2109	  In support of Kernel Address Space Layout Randomization (KASLR),
2110	  this randomizes the physical address at which the kernel image
2111	  is decompressed and the virtual address where the kernel
2112	  image is mapped, as a security feature that deters exploit
2113	  attempts relying on knowledge of the location of kernel
2114	  code internals.
2115
2116	  On 64-bit, the kernel physical and virtual addresses are
2117	  randomized separately. The physical address will be anywhere
2118	  between 16MB and the top of physical memory (up to 64TB). The
2119	  virtual address will be randomized from 16MB up to 1GB (9 bits
2120	  of entropy). Note that this also reduces the memory space
2121	  available to kernel modules from 1.5GB to 1GB.
2122
2123	  On 32-bit, the kernel physical and virtual addresses are
2124	  randomized together. They will be randomized from 16MB up to
2125	  512MB (8 bits of entropy).
2126
2127	  Entropy is generated using the RDRAND instruction if it is
2128	  supported. If RDTSC is supported, its value is mixed into
2129	  the entropy pool as well. If neither RDRAND nor RDTSC are
2130	  supported, then entropy is read from the i8254 timer. The
2131	  usable entropy is limited by the kernel being built using
2132	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2133	  minimum of 2MB. As a result, only 10 bits of entropy are
2134	  theoretically possible, but the implementations are further
2135	  limited due to memory layouts.
2136
2137	  If unsure, say Y.
2138
2139# Relocation on x86 needs some additional build support
2140config X86_NEED_RELOCS
2141	def_bool y
2142	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2143
2144config PHYSICAL_ALIGN
2145	hex "Alignment value to which kernel should be aligned"
2146	default "0x200000"
2147	range 0x2000 0x1000000 if X86_32
2148	range 0x200000 0x1000000 if X86_64
2149	---help---
2150	  This value puts the alignment restrictions on physical address
2151	  where kernel is loaded and run from. Kernel is compiled for an
2152	  address which meets above alignment restriction.
2153
2154	  If bootloader loads the kernel at a non-aligned address and
2155	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2156	  address aligned to above value and run from there.
2157
2158	  If bootloader loads the kernel at a non-aligned address and
2159	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2160	  load address and decompress itself to the address it has been
2161	  compiled for and run from there. The address for which kernel is
2162	  compiled already meets above alignment restrictions. Hence the
2163	  end result is that kernel runs from a physical address meeting
2164	  above alignment restrictions.
2165
2166	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2167	  this value must be a multiple of 0x200000.
2168
2169	  Don't change this unless you know what you are doing.
2170
2171config DYNAMIC_MEMORY_LAYOUT
2172	bool
2173	---help---
2174	  This option makes base addresses of vmalloc and vmemmap as well as
2175	  __PAGE_OFFSET movable during boot.
2176
2177config RANDOMIZE_MEMORY
2178	bool "Randomize the kernel memory sections"
2179	depends on X86_64
2180	depends on RANDOMIZE_BASE
2181	select DYNAMIC_MEMORY_LAYOUT
2182	default RANDOMIZE_BASE
2183	---help---
2184	   Randomizes the base virtual address of kernel memory sections
2185	   (physical memory mapping, vmalloc & vmemmap). This security feature
2186	   makes exploits relying on predictable memory locations less reliable.
2187
2188	   The order of allocations remains unchanged. Entropy is generated in
2189	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2190	   configuration have in average 30,000 different possible virtual
2191	   addresses for each memory section.
2192
2193	   If unsure, say Y.
2194
2195config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2196	hex "Physical memory mapping padding" if EXPERT
2197	depends on RANDOMIZE_MEMORY
2198	default "0xa" if MEMORY_HOTPLUG
2199	default "0x0"
2200	range 0x1 0x40 if MEMORY_HOTPLUG
2201	range 0x0 0x40
2202	---help---
2203	   Define the padding in terabytes added to the existing physical
2204	   memory size during kernel memory randomization. It is useful
2205	   for memory hotplug support but reduces the entropy available for
2206	   address randomization.
2207
2208	   If unsure, leave at the default value.
2209
2210config HOTPLUG_CPU
2211	bool "Support for hot-pluggable CPUs"
2212	depends on SMP
2213	---help---
2214	  Say Y here to allow turning CPUs off and on. CPUs can be
2215	  controlled through /sys/devices/system/cpu.
2216	  ( Note: power management support will enable this option
2217	    automatically on SMP systems. )
2218	  Say N if you want to disable CPU hotplug.
2219
2220config BOOTPARAM_HOTPLUG_CPU0
2221	bool "Set default setting of cpu0_hotpluggable"
2222	default n
2223	depends on HOTPLUG_CPU
2224	---help---
2225	  Set whether default state of cpu0_hotpluggable is on or off.
2226
2227	  Say Y here to enable CPU0 hotplug by default. If this switch
2228	  is turned on, there is no need to give cpu0_hotplug kernel
2229	  parameter and the CPU0 hotplug feature is enabled by default.
2230
2231	  Please note: there are two known CPU0 dependencies if you want
2232	  to enable the CPU0 hotplug feature either by this switch or by
2233	  cpu0_hotplug kernel parameter.
2234
2235	  First, resume from hibernate or suspend always starts from CPU0.
2236	  So hibernate and suspend are prevented if CPU0 is offline.
2237
2238	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2239	  offline if any interrupt can not migrate out of CPU0. There may
2240	  be other CPU0 dependencies.
2241
2242	  Please make sure the dependencies are under your control before
2243	  you enable this feature.
2244
2245	  Say N if you don't want to enable CPU0 hotplug feature by default.
2246	  You still can enable the CPU0 hotplug feature at boot by kernel
2247	  parameter cpu0_hotplug.
2248
2249config DEBUG_HOTPLUG_CPU0
2250	def_bool n
2251	prompt "Debug CPU0 hotplug"
2252	depends on HOTPLUG_CPU
2253	---help---
2254	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2255	  soon as possible and boots up userspace with CPU0 offlined. User
2256	  can online CPU0 back after boot time.
2257
2258	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2259	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2260	  compilation or giving cpu0_hotplug kernel parameter at boot.
2261
2262	  If unsure, say N.
2263
2264config COMPAT_VDSO
2265	def_bool n
2266	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2267	depends on COMPAT_32
2268	---help---
2269	  Certain buggy versions of glibc will crash if they are
2270	  presented with a 32-bit vDSO that is not mapped at the address
2271	  indicated in its segment table.
2272
2273	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2274	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2275	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2276	  the only released version with the bug, but OpenSUSE 9
2277	  contains a buggy "glibc 2.3.2".
2278
2279	  The symptom of the bug is that everything crashes on startup, saying:
2280	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2281
2282	  Saying Y here changes the default value of the vdso32 boot
2283	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2284	  This works around the glibc bug but hurts performance.
2285
2286	  If unsure, say N: if you are compiling your own kernel, you
2287	  are unlikely to be using a buggy version of glibc.
2288
2289choice
2290	prompt "vsyscall table for legacy applications"
2291	depends on X86_64
2292	default LEGACY_VSYSCALL_EMULATE
2293	help
2294	  Legacy user code that does not know how to find the vDSO expects
2295	  to be able to issue three syscalls by calling fixed addresses in
2296	  kernel space. Since this location is not randomized with ASLR,
2297	  it can be used to assist security vulnerability exploitation.
2298
2299	  This setting can be changed at boot time via the kernel command
2300	  line parameter vsyscall=[emulate|none].
2301
2302	  On a system with recent enough glibc (2.14 or newer) and no
2303	  static binaries, you can say None without a performance penalty
2304	  to improve security.
2305
2306	  If unsure, select "Emulate".
2307
2308	config LEGACY_VSYSCALL_EMULATE
2309		bool "Emulate"
2310		help
2311		  The kernel traps and emulates calls into the fixed
2312		  vsyscall address mapping. This makes the mapping
2313		  non-executable, but it still contains known contents,
2314		  which could be used in certain rare security vulnerability
2315		  exploits. This configuration is recommended when userspace
2316		  still uses the vsyscall area.
2317
2318	config LEGACY_VSYSCALL_NONE
2319		bool "None"
2320		help
2321		  There will be no vsyscall mapping at all. This will
2322		  eliminate any risk of ASLR bypass due to the vsyscall
2323		  fixed address mapping. Attempts to use the vsyscalls
2324		  will be reported to dmesg, so that either old or
2325		  malicious userspace programs can be identified.
2326
2327endchoice
2328
2329config CMDLINE_BOOL
2330	bool "Built-in kernel command line"
2331	---help---
2332	  Allow for specifying boot arguments to the kernel at
2333	  build time.  On some systems (e.g. embedded ones), it is
2334	  necessary or convenient to provide some or all of the
2335	  kernel boot arguments with the kernel itself (that is,
2336	  to not rely on the boot loader to provide them.)
2337
2338	  To compile command line arguments into the kernel,
2339	  set this option to 'Y', then fill in the
2340	  boot arguments in CONFIG_CMDLINE.
2341
2342	  Systems with fully functional boot loaders (i.e. non-embedded)
2343	  should leave this option set to 'N'.
2344
2345config CMDLINE
2346	string "Built-in kernel command string"
2347	depends on CMDLINE_BOOL
2348	default ""
2349	---help---
2350	  Enter arguments here that should be compiled into the kernel
2351	  image and used at boot time.  If the boot loader provides a
2352	  command line at boot time, it is appended to this string to
2353	  form the full kernel command line, when the system boots.
2354
2355	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2356	  change this behavior.
2357
2358	  In most cases, the command line (whether built-in or provided
2359	  by the boot loader) should specify the device for the root
2360	  file system.
2361
2362config CMDLINE_OVERRIDE
2363	bool "Built-in command line overrides boot loader arguments"
2364	depends on CMDLINE_BOOL
2365	---help---
2366	  Set this option to 'Y' to have the kernel ignore the boot loader
2367	  command line, and use ONLY the built-in command line.
2368
2369	  This is used to work around broken boot loaders.  This should
2370	  be set to 'N' under normal conditions.
2371
2372config MODIFY_LDT_SYSCALL
2373	bool "Enable the LDT (local descriptor table)" if EXPERT
2374	default y
2375	---help---
2376	  Linux can allow user programs to install a per-process x86
2377	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2378	  call.  This is required to run 16-bit or segmented code such as
2379	  DOSEMU or some Wine programs.  It is also used by some very old
2380	  threading libraries.
2381
2382	  Enabling this feature adds a small amount of overhead to
2383	  context switches and increases the low-level kernel attack
2384	  surface.  Disabling it removes the modify_ldt(2) system call.
2385
2386	  Saying 'N' here may make sense for embedded or server kernels.
2387
2388source "kernel/livepatch/Kconfig"
2389
2390endmenu
2391
2392config ARCH_HAS_ADD_PAGES
2393	def_bool y
2394	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2395
2396config ARCH_ENABLE_MEMORY_HOTPLUG
2397	def_bool y
2398	depends on X86_64 || (X86_32 && HIGHMEM)
2399
2400config ARCH_ENABLE_MEMORY_HOTREMOVE
2401	def_bool y
2402	depends on MEMORY_HOTPLUG
2403
2404config USE_PERCPU_NUMA_NODE_ID
2405	def_bool y
2406	depends on NUMA
2407
2408config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2409	def_bool y
2410	depends on X86_64 || X86_PAE
2411
2412config ARCH_ENABLE_HUGEPAGE_MIGRATION
2413	def_bool y
2414	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2415
2416config ARCH_ENABLE_THP_MIGRATION
2417	def_bool y
2418	depends on X86_64 && TRANSPARENT_HUGEPAGE
2419
2420menu "Power management and ACPI options"
2421
2422config ARCH_HIBERNATION_HEADER
2423	def_bool y
2424	depends on X86_64 && HIBERNATION
2425
2426source "kernel/power/Kconfig"
2427
2428source "drivers/acpi/Kconfig"
2429
2430source "drivers/sfi/Kconfig"
2431
2432config X86_APM_BOOT
2433	def_bool y
2434	depends on APM
2435
2436menuconfig APM
2437	tristate "APM (Advanced Power Management) BIOS support"
2438	depends on X86_32 && PM_SLEEP
2439	---help---
2440	  APM is a BIOS specification for saving power using several different
2441	  techniques. This is mostly useful for battery powered laptops with
2442	  APM compliant BIOSes. If you say Y here, the system time will be
2443	  reset after a RESUME operation, the /proc/apm device will provide
2444	  battery status information, and user-space programs will receive
2445	  notification of APM "events" (e.g. battery status change).
2446
2447	  If you select "Y" here, you can disable actual use of the APM
2448	  BIOS by passing the "apm=off" option to the kernel at boot time.
2449
2450	  Note that the APM support is almost completely disabled for
2451	  machines with more than one CPU.
2452
2453	  In order to use APM, you will need supporting software. For location
2454	  and more information, read <file:Documentation/power/apm-acpi.txt>
2455	  and the Battery Powered Linux mini-HOWTO, available from
2456	  <http://www.tldp.org/docs.html#howto>.
2457
2458	  This driver does not spin down disk drives (see the hdparm(8)
2459	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2460	  VESA-compliant "green" monitors.
2461
2462	  This driver does not support the TI 4000M TravelMate and the ACER
2463	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2464	  desktop machines also don't have compliant BIOSes, and this driver
2465	  may cause those machines to panic during the boot phase.
2466
2467	  Generally, if you don't have a battery in your machine, there isn't
2468	  much point in using this driver and you should say N. If you get
2469	  random kernel OOPSes or reboots that don't seem to be related to
2470	  anything, try disabling/enabling this option (or disabling/enabling
2471	  APM in your BIOS).
2472
2473	  Some other things you should try when experiencing seemingly random,
2474	  "weird" problems:
2475
2476	  1) make sure that you have enough swap space and that it is
2477	  enabled.
2478	  2) pass the "no-hlt" option to the kernel
2479	  3) switch on floating point emulation in the kernel and pass
2480	  the "no387" option to the kernel
2481	  4) pass the "floppy=nodma" option to the kernel
2482	  5) pass the "mem=4M" option to the kernel (thereby disabling
2483	  all but the first 4 MB of RAM)
2484	  6) make sure that the CPU is not over clocked.
2485	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2486	  8) disable the cache from your BIOS settings
2487	  9) install a fan for the video card or exchange video RAM
2488	  10) install a better fan for the CPU
2489	  11) exchange RAM chips
2490	  12) exchange the motherboard.
2491
2492	  To compile this driver as a module, choose M here: the
2493	  module will be called apm.
2494
2495if APM
2496
2497config APM_IGNORE_USER_SUSPEND
2498	bool "Ignore USER SUSPEND"
2499	---help---
2500	  This option will ignore USER SUSPEND requests. On machines with a
2501	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2502	  series notebooks, it is necessary to say Y because of a BIOS bug.
2503
2504config APM_DO_ENABLE
2505	bool "Enable PM at boot time"
2506	---help---
2507	  Enable APM features at boot time. From page 36 of the APM BIOS
2508	  specification: "When disabled, the APM BIOS does not automatically
2509	  power manage devices, enter the Standby State, enter the Suspend
2510	  State, or take power saving steps in response to CPU Idle calls."
2511	  This driver will make CPU Idle calls when Linux is idle (unless this
2512	  feature is turned off -- see "Do CPU IDLE calls", below). This
2513	  should always save battery power, but more complicated APM features
2514	  will be dependent on your BIOS implementation. You may need to turn
2515	  this option off if your computer hangs at boot time when using APM
2516	  support, or if it beeps continuously instead of suspending. Turn
2517	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2518	  T400CDT. This is off by default since most machines do fine without
2519	  this feature.
2520
2521config APM_CPU_IDLE
2522	depends on CPU_IDLE
2523	bool "Make CPU Idle calls when idle"
2524	---help---
2525	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2526	  On some machines, this can activate improved power savings, such as
2527	  a slowed CPU clock rate, when the machine is idle. These idle calls
2528	  are made after the idle loop has run for some length of time (e.g.,
2529	  333 mS). On some machines, this will cause a hang at boot time or
2530	  whenever the CPU becomes idle. (On machines with more than one CPU,
2531	  this option does nothing.)
2532
2533config APM_DISPLAY_BLANK
2534	bool "Enable console blanking using APM"
2535	---help---
2536	  Enable console blanking using the APM. Some laptops can use this to
2537	  turn off the LCD backlight when the screen blanker of the Linux
2538	  virtual console blanks the screen. Note that this is only used by
2539	  the virtual console screen blanker, and won't turn off the backlight
2540	  when using the X Window system. This also doesn't have anything to
2541	  do with your VESA-compliant power-saving monitor. Further, this
2542	  option doesn't work for all laptops -- it might not turn off your
2543	  backlight at all, or it might print a lot of errors to the console,
2544	  especially if you are using gpm.
2545
2546config APM_ALLOW_INTS
2547	bool "Allow interrupts during APM BIOS calls"
2548	---help---
2549	  Normally we disable external interrupts while we are making calls to
2550	  the APM BIOS as a measure to lessen the effects of a badly behaving
2551	  BIOS implementation.  The BIOS should reenable interrupts if it
2552	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2553	  many of the newer IBM Thinkpads.  If you experience hangs when you
2554	  suspend, try setting this to Y.  Otherwise, say N.
2555
2556endif # APM
2557
2558source "drivers/cpufreq/Kconfig"
2559
2560source "drivers/cpuidle/Kconfig"
2561
2562source "drivers/idle/Kconfig"
2563
2564endmenu
2565
2566
2567menu "Bus options (PCI etc.)"
2568
2569config PCI
2570	bool "PCI support"
2571	default y
2572	---help---
2573	  Find out whether you have a PCI motherboard. PCI is the name of a
2574	  bus system, i.e. the way the CPU talks to the other stuff inside
2575	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2576	  VESA. If you have PCI, say Y, otherwise N.
2577
2578choice
2579	prompt "PCI access mode"
2580	depends on X86_32 && PCI
2581	default PCI_GOANY
2582	---help---
2583	  On PCI systems, the BIOS can be used to detect the PCI devices and
2584	  determine their configuration. However, some old PCI motherboards
2585	  have BIOS bugs and may crash if this is done. Also, some embedded
2586	  PCI-based systems don't have any BIOS at all. Linux can also try to
2587	  detect the PCI hardware directly without using the BIOS.
2588
2589	  With this option, you can specify how Linux should detect the
2590	  PCI devices. If you choose "BIOS", the BIOS will be used,
2591	  if you choose "Direct", the BIOS won't be used, and if you
2592	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2593	  If you choose "Any", the kernel will try MMCONFIG, then the
2594	  direct access method and falls back to the BIOS if that doesn't
2595	  work. If unsure, go with the default, which is "Any".
2596
2597config PCI_GOBIOS
2598	bool "BIOS"
2599
2600config PCI_GOMMCONFIG
2601	bool "MMConfig"
2602
2603config PCI_GODIRECT
2604	bool "Direct"
2605
2606config PCI_GOOLPC
2607	bool "OLPC XO-1"
2608	depends on OLPC
2609
2610config PCI_GOANY
2611	bool "Any"
2612
2613endchoice
2614
2615config PCI_BIOS
2616	def_bool y
2617	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2618
2619# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2620config PCI_DIRECT
2621	def_bool y
2622	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2623
2624config PCI_MMCONFIG
2625	bool "Support mmconfig PCI config space access" if X86_64
2626	default y
2627	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2628	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2629
2630config PCI_OLPC
2631	def_bool y
2632	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2633
2634config PCI_XEN
2635	def_bool y
2636	depends on PCI && XEN
2637	select SWIOTLB_XEN
2638
2639config PCI_DOMAINS
2640	def_bool y
2641	depends on PCI
2642
2643config MMCONF_FAM10H
2644	def_bool y
2645	depends on X86_64 && PCI_MMCONFIG && ACPI
2646
2647config PCI_CNB20LE_QUIRK
2648	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2649	depends on PCI
2650	help
2651	  Read the PCI windows out of the CNB20LE host bridge. This allows
2652	  PCI hotplug to work on systems with the CNB20LE chipset which do
2653	  not have ACPI.
2654
2655	  There's no public spec for this chipset, and this functionality
2656	  is known to be incomplete.
2657
2658	  You should say N unless you know you need this.
2659
2660source "drivers/pci/Kconfig"
2661
2662config ISA_BUS
2663	bool "ISA bus support on modern systems" if EXPERT
2664	help
2665	  Expose ISA bus device drivers and options available for selection and
2666	  configuration. Enable this option if your target machine has an ISA
2667	  bus. ISA is an older system, displaced by PCI and newer bus
2668	  architectures -- if your target machine is modern, it probably does
2669	  not have an ISA bus.
2670
2671	  If unsure, say N.
2672
2673# x86_64 have no ISA slots, but can have ISA-style DMA.
2674config ISA_DMA_API
2675	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2676	default y
2677	help
2678	  Enables ISA-style DMA support for devices requiring such controllers.
2679	  If unsure, say Y.
2680
2681if X86_32
2682
2683config ISA
2684	bool "ISA support"
2685	---help---
2686	  Find out whether you have ISA slots on your motherboard.  ISA is the
2687	  name of a bus system, i.e. the way the CPU talks to the other stuff
2688	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2689	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2690	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2691
2692config EISA
2693	bool "EISA support"
2694	depends on ISA
2695	---help---
2696	  The Extended Industry Standard Architecture (EISA) bus was
2697	  developed as an open alternative to the IBM MicroChannel bus.
2698
2699	  The EISA bus provided some of the features of the IBM MicroChannel
2700	  bus while maintaining backward compatibility with cards made for
2701	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2702	  1995 when it was made obsolete by the PCI bus.
2703
2704	  Say Y here if you are building a kernel for an EISA-based machine.
2705
2706	  Otherwise, say N.
2707
2708source "drivers/eisa/Kconfig"
2709
2710config SCx200
2711	tristate "NatSemi SCx200 support"
2712	---help---
2713	  This provides basic support for National Semiconductor's
2714	  (now AMD's) Geode processors.  The driver probes for the
2715	  PCI-IDs of several on-chip devices, so its a good dependency
2716	  for other scx200_* drivers.
2717
2718	  If compiled as a module, the driver is named scx200.
2719
2720config SCx200HR_TIMER
2721	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2722	depends on SCx200
2723	default y
2724	---help---
2725	  This driver provides a clocksource built upon the on-chip
2726	  27MHz high-resolution timer.  Its also a workaround for
2727	  NSC Geode SC-1100's buggy TSC, which loses time when the
2728	  processor goes idle (as is done by the scheduler).  The
2729	  other workaround is idle=poll boot option.
2730
2731config OLPC
2732	bool "One Laptop Per Child support"
2733	depends on !X86_PAE
2734	select GPIOLIB
2735	select OF
2736	select OF_PROMTREE
2737	select IRQ_DOMAIN
2738	---help---
2739	  Add support for detecting the unique features of the OLPC
2740	  XO hardware.
2741
2742config OLPC_XO1_PM
2743	bool "OLPC XO-1 Power Management"
2744	depends on OLPC && MFD_CS5535 && PM_SLEEP
2745	select MFD_CORE
2746	---help---
2747	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2748
2749config OLPC_XO1_RTC
2750	bool "OLPC XO-1 Real Time Clock"
2751	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2752	---help---
2753	  Add support for the XO-1 real time clock, which can be used as a
2754	  programmable wakeup source.
2755
2756config OLPC_XO1_SCI
2757	bool "OLPC XO-1 SCI extras"
2758	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2759	depends on INPUT=y
2760	select POWER_SUPPLY
2761	---help---
2762	  Add support for SCI-based features of the OLPC XO-1 laptop:
2763	   - EC-driven system wakeups
2764	   - Power button
2765	   - Ebook switch
2766	   - Lid switch
2767	   - AC adapter status updates
2768	   - Battery status updates
2769
2770config OLPC_XO15_SCI
2771	bool "OLPC XO-1.5 SCI extras"
2772	depends on OLPC && ACPI
2773	select POWER_SUPPLY
2774	---help---
2775	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2776	   - EC-driven system wakeups
2777	   - AC adapter status updates
2778	   - Battery status updates
2779
2780config ALIX
2781	bool "PCEngines ALIX System Support (LED setup)"
2782	select GPIOLIB
2783	---help---
2784	  This option enables system support for the PCEngines ALIX.
2785	  At present this just sets up LEDs for GPIO control on
2786	  ALIX2/3/6 boards.  However, other system specific setup should
2787	  get added here.
2788
2789	  Note: You must still enable the drivers for GPIO and LED support
2790	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2791
2792	  Note: You have to set alix.force=1 for boards with Award BIOS.
2793
2794config NET5501
2795	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2796	select GPIOLIB
2797	---help---
2798	  This option enables system support for the Soekris Engineering net5501.
2799
2800config GEOS
2801	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2802	select GPIOLIB
2803	depends on DMI
2804	---help---
2805	  This option enables system support for the Traverse Technologies GEOS.
2806
2807config TS5500
2808	bool "Technologic Systems TS-5500 platform support"
2809	depends on MELAN
2810	select CHECK_SIGNATURE
2811	select NEW_LEDS
2812	select LEDS_CLASS
2813	---help---
2814	  This option enables system support for the Technologic Systems TS-5500.
2815
2816endif # X86_32
2817
2818config AMD_NB
2819	def_bool y
2820	depends on CPU_SUP_AMD && PCI
2821
2822source "drivers/pcmcia/Kconfig"
2823
2824config RAPIDIO
2825	tristate "RapidIO support"
2826	depends on PCI
2827	default n
2828	help
2829	  If enabled this option will include drivers and the core
2830	  infrastructure code to support RapidIO interconnect devices.
2831
2832source "drivers/rapidio/Kconfig"
2833
2834config X86_SYSFB
2835	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2836	help
2837	  Firmwares often provide initial graphics framebuffers so the BIOS,
2838	  bootloader or kernel can show basic video-output during boot for
2839	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2840	  Extensions and EFI-framebuffers for this, which are mostly limited
2841	  to x86.
2842	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2843	  framebuffers so the new generic system-framebuffer drivers can be
2844	  used on x86. If the framebuffer is not compatible with the generic
2845	  modes, it is adverticed as fallback platform framebuffer so legacy
2846	  drivers like efifb, vesafb and uvesafb can pick it up.
2847	  If this option is not selected, all system framebuffers are always
2848	  marked as fallback platform framebuffers as usual.
2849
2850	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2851	  not be able to pick up generic system framebuffers if this option
2852	  is selected. You are highly encouraged to enable simplefb as
2853	  replacement if you select this option. simplefb can correctly deal
2854	  with generic system framebuffers. But you should still keep vesafb
2855	  and others enabled as fallback if a system framebuffer is
2856	  incompatible with simplefb.
2857
2858	  If unsure, say Y.
2859
2860endmenu
2861
2862
2863menu "Binary Emulations"
2864
2865config IA32_EMULATION
2866	bool "IA32 Emulation"
2867	depends on X86_64
2868	select ARCH_WANT_OLD_COMPAT_IPC
2869	select BINFMT_ELF
2870	select COMPAT_BINFMT_ELF
2871	select COMPAT_OLD_SIGACTION
2872	---help---
2873	  Include code to run legacy 32-bit programs under a
2874	  64-bit kernel. You should likely turn this on, unless you're
2875	  100% sure that you don't have any 32-bit programs left.
2876
2877config IA32_AOUT
2878	tristate "IA32 a.out support"
2879	depends on IA32_EMULATION
2880	---help---
2881	  Support old a.out binaries in the 32bit emulation.
2882
2883config X86_X32
2884	bool "x32 ABI for 64-bit mode"
2885	depends on X86_64
2886	---help---
2887	  Include code to run binaries for the x32 native 32-bit ABI
2888	  for 64-bit processors.  An x32 process gets access to the
2889	  full 64-bit register file and wide data path while leaving
2890	  pointers at 32 bits for smaller memory footprint.
2891
2892	  You will need a recent binutils (2.22 or later) with
2893	  elf32_x86_64 support enabled to compile a kernel with this
2894	  option set.
2895
2896config COMPAT_32
2897	def_bool y
2898	depends on IA32_EMULATION || X86_32
2899	select HAVE_UID16
2900	select OLD_SIGSUSPEND3
2901
2902config COMPAT
2903	def_bool y
2904	depends on IA32_EMULATION || X86_X32
2905
2906if COMPAT
2907config COMPAT_FOR_U64_ALIGNMENT
2908	def_bool y
2909
2910config SYSVIPC_COMPAT
2911	def_bool y
2912	depends on SYSVIPC
2913endif
2914
2915endmenu
2916
2917
2918config HAVE_ATOMIC_IOMAP
2919	def_bool y
2920	depends on X86_32
2921
2922config X86_DEV_DMA_OPS
2923	bool
2924	depends on X86_64 || STA2X11
2925
2926config X86_DMA_REMAP
2927	bool
2928	depends on STA2X11
2929
2930config HAVE_GENERIC_GUP
2931	def_bool y
2932
2933source "drivers/firmware/Kconfig"
2934
2935source "arch/x86/kvm/Kconfig"
2936