xref: /openbmc/linux/arch/x86/Kconfig (revision 55b078f0)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select X86_DEV_DMA_OPS
34	select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40#   ported to 32-bit as well. )
41#
42config X86
43	def_bool y
44	#
45	# Note: keep this list sorted alphabetically
46	#
47	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
48	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
49	select ANON_INODES
50	select ARCH_CLOCKSOURCE_DATA
51	select ARCH_CLOCKSOURCE_INIT
52	select ARCH_DISCARD_MEMBLOCK
53	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
54	select ARCH_HAS_DEBUG_VIRTUAL
55	select ARCH_HAS_DEVMEM_IS_ALLOWED
56	select ARCH_HAS_ELF_RANDOMIZE
57	select ARCH_HAS_FAST_MULTIPLIER
58	select ARCH_HAS_FILTER_PGPROT
59	select ARCH_HAS_FORTIFY_SOURCE
60	select ARCH_HAS_GCOV_PROFILE_ALL
61	select ARCH_HAS_KCOV			if X86_64
62	select ARCH_HAS_MEMBARRIER_SYNC_CORE
63	select ARCH_HAS_PMEM_API		if X86_64
64	select ARCH_HAS_PTE_SPECIAL
65	select ARCH_HAS_REFCOUNT
66	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
67	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
68	select ARCH_HAS_SET_MEMORY
69	select ARCH_HAS_SG_CHAIN
70	select ARCH_HAS_STRICT_KERNEL_RWX
71	select ARCH_HAS_STRICT_MODULE_RWX
72	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
73	select ARCH_HAS_UBSAN_SANITIZE_ALL
74	select ARCH_HAS_ZONE_DEVICE		if X86_64
75	select ARCH_HAVE_NMI_SAFE_CMPXCHG
76	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
77	select ARCH_MIGHT_HAVE_PC_PARPORT
78	select ARCH_MIGHT_HAVE_PC_SERIO
79	select ARCH_SUPPORTS_ACPI
80	select ARCH_SUPPORTS_ATOMIC_RMW
81	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
82	select ARCH_USE_BUILTIN_BSWAP
83	select ARCH_USE_QUEUED_RWLOCKS
84	select ARCH_USE_QUEUED_SPINLOCKS
85	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
86	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
87	select ARCH_WANTS_THP_SWAP		if X86_64
88	select BUILDTIME_EXTABLE_SORT
89	select CLKEVT_I8253
90	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
91	select CLOCKSOURCE_WATCHDOG
92	select DCACHE_WORD_ACCESS
93	select DMA_DIRECT_OPS
94	select EDAC_ATOMIC_SCRUB
95	select EDAC_SUPPORT
96	select GENERIC_CLOCKEVENTS
97	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
98	select GENERIC_CLOCKEVENTS_MIN_ADJUST
99	select GENERIC_CMOS_UPDATE
100	select GENERIC_CPU_AUTOPROBE
101	select GENERIC_CPU_VULNERABILITIES
102	select GENERIC_EARLY_IOREMAP
103	select GENERIC_FIND_FIRST_BIT
104	select GENERIC_IOMAP
105	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
106	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
107	select GENERIC_IRQ_MIGRATION		if SMP
108	select GENERIC_IRQ_PROBE
109	select GENERIC_IRQ_RESERVATION_MODE
110	select GENERIC_IRQ_SHOW
111	select GENERIC_PENDING_IRQ		if SMP
112	select GENERIC_SMP_IDLE_THREAD
113	select GENERIC_STRNCPY_FROM_USER
114	select GENERIC_STRNLEN_USER
115	select GENERIC_TIME_VSYSCALL
116	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
117	select HAVE_ACPI_APEI			if ACPI
118	select HAVE_ACPI_APEI_NMI		if ACPI
119	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
120	select HAVE_ARCH_AUDITSYSCALL
121	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
122	select HAVE_ARCH_JUMP_LABEL
123	select HAVE_ARCH_JUMP_LABEL_RELATIVE
124	select HAVE_ARCH_KASAN			if X86_64
125	select HAVE_ARCH_KGDB
126	select HAVE_ARCH_MMAP_RND_BITS		if MMU
127	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
128	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
129	select HAVE_ARCH_PREL32_RELOCATIONS
130	select HAVE_ARCH_SECCOMP_FILTER
131	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
132	select HAVE_ARCH_STACKLEAK
133	select HAVE_ARCH_TRACEHOOK
134	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
135	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
136	select HAVE_ARCH_VMAP_STACK		if X86_64
137	select HAVE_ARCH_WITHIN_STACK_FRAMES
138	select HAVE_CMPXCHG_DOUBLE
139	select HAVE_CMPXCHG_LOCAL
140	select HAVE_CONTEXT_TRACKING		if X86_64
141	select HAVE_COPY_THREAD_TLS
142	select HAVE_C_RECORDMCOUNT
143	select HAVE_DEBUG_KMEMLEAK
144	select HAVE_DEBUG_STACKOVERFLOW
145	select HAVE_DMA_CONTIGUOUS
146	select HAVE_DYNAMIC_FTRACE
147	select HAVE_DYNAMIC_FTRACE_WITH_REGS
148	select HAVE_EBPF_JIT
149	select HAVE_EFFICIENT_UNALIGNED_ACCESS
150	select HAVE_EXIT_THREAD
151	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
152	select HAVE_FTRACE_MCOUNT_RECORD
153	select HAVE_FUNCTION_GRAPH_TRACER
154	select HAVE_FUNCTION_TRACER
155	select HAVE_GCC_PLUGINS
156	select HAVE_HW_BREAKPOINT
157	select HAVE_IDE
158	select HAVE_IOREMAP_PROT
159	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
160	select HAVE_IRQ_TIME_ACCOUNTING
161	select HAVE_KERNEL_BZIP2
162	select HAVE_KERNEL_GZIP
163	select HAVE_KERNEL_LZ4
164	select HAVE_KERNEL_LZMA
165	select HAVE_KERNEL_LZO
166	select HAVE_KERNEL_XZ
167	select HAVE_KPROBES
168	select HAVE_KPROBES_ON_FTRACE
169	select HAVE_FUNCTION_ERROR_INJECTION
170	select HAVE_KRETPROBES
171	select HAVE_KVM
172	select HAVE_LIVEPATCH			if X86_64
173	select HAVE_MEMBLOCK_NODE_MAP
174	select HAVE_MIXED_BREAKPOINTS_REGS
175	select HAVE_MOD_ARCH_SPECIFIC
176	select HAVE_NMI
177	select HAVE_OPROFILE
178	select HAVE_OPTPROBES
179	select HAVE_PCSPKR_PLATFORM
180	select HAVE_PERF_EVENTS
181	select HAVE_PERF_EVENTS_NMI
182	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
183	select HAVE_PERF_REGS
184	select HAVE_PERF_USER_STACK_DUMP
185	select HAVE_RCU_TABLE_FREE		if PARAVIRT
186	select HAVE_RCU_TABLE_INVALIDATE	if HAVE_RCU_TABLE_FREE
187	select HAVE_REGS_AND_STACK_ACCESS_API
188	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
189	select HAVE_FUNCTION_ARG_ACCESS_API
190	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
191	select HAVE_STACK_VALIDATION		if X86_64
192	select HAVE_RSEQ
193	select HAVE_SYSCALL_TRACEPOINTS
194	select HAVE_UNSTABLE_SCHED_CLOCK
195	select HAVE_USER_RETURN_NOTIFIER
196	select HOTPLUG_SMT			if SMP
197	select IRQ_FORCED_THREADING
198	select NEED_SG_DMA_LENGTH
199	select PCI_LOCKLESS_CONFIG
200	select PERF_EVENTS
201	select RTC_LIB
202	select RTC_MC146818_LIB
203	select SPARSE_IRQ
204	select SRCU
205	select SYSCTL_EXCEPTION_TRACE
206	select THREAD_INFO_IN_TASK
207	select USER_STACKTRACE_SUPPORT
208	select VIRT_TO_BUS
209	select X86_FEATURE_NAMES		if PROC_FS
210
211config INSTRUCTION_DECODER
212	def_bool y
213	depends on KPROBES || PERF_EVENTS || UPROBES
214
215config OUTPUT_FORMAT
216	string
217	default "elf32-i386" if X86_32
218	default "elf64-x86-64" if X86_64
219
220config ARCH_DEFCONFIG
221	string
222	default "arch/x86/configs/i386_defconfig" if X86_32
223	default "arch/x86/configs/x86_64_defconfig" if X86_64
224
225config LOCKDEP_SUPPORT
226	def_bool y
227
228config STACKTRACE_SUPPORT
229	def_bool y
230
231config MMU
232	def_bool y
233
234config ARCH_MMAP_RND_BITS_MIN
235	default 28 if 64BIT
236	default 8
237
238config ARCH_MMAP_RND_BITS_MAX
239	default 32 if 64BIT
240	default 16
241
242config ARCH_MMAP_RND_COMPAT_BITS_MIN
243	default 8
244
245config ARCH_MMAP_RND_COMPAT_BITS_MAX
246	default 16
247
248config SBUS
249	bool
250
251config GENERIC_ISA_DMA
252	def_bool y
253	depends on ISA_DMA_API
254
255config GENERIC_BUG
256	def_bool y
257	depends on BUG
258	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
259
260config GENERIC_BUG_RELATIVE_POINTERS
261	bool
262
263config GENERIC_HWEIGHT
264	def_bool y
265
266config ARCH_MAY_HAVE_PC_FDC
267	def_bool y
268	depends on ISA_DMA_API
269
270config RWSEM_XCHGADD_ALGORITHM
271	def_bool y
272
273config GENERIC_CALIBRATE_DELAY
274	def_bool y
275
276config ARCH_HAS_CPU_RELAX
277	def_bool y
278
279config ARCH_HAS_CACHE_LINE_SIZE
280	def_bool y
281
282config ARCH_HAS_FILTER_PGPROT
283	def_bool y
284
285config HAVE_SETUP_PER_CPU_AREA
286	def_bool y
287
288config NEED_PER_CPU_EMBED_FIRST_CHUNK
289	def_bool y
290
291config NEED_PER_CPU_PAGE_FIRST_CHUNK
292	def_bool y
293
294config ARCH_HIBERNATION_POSSIBLE
295	def_bool y
296
297config ARCH_SUSPEND_POSSIBLE
298	def_bool y
299
300config ARCH_WANT_HUGE_PMD_SHARE
301	def_bool y
302
303config ARCH_WANT_GENERAL_HUGETLB
304	def_bool y
305
306config ZONE_DMA32
307	def_bool y if X86_64
308
309config AUDIT_ARCH
310	def_bool y if X86_64
311
312config ARCH_SUPPORTS_OPTIMIZED_INLINING
313	def_bool y
314
315config ARCH_SUPPORTS_DEBUG_PAGEALLOC
316	def_bool y
317
318config KASAN_SHADOW_OFFSET
319	hex
320	depends on KASAN
321	default 0xdffffc0000000000
322
323config HAVE_INTEL_TXT
324	def_bool y
325	depends on INTEL_IOMMU && ACPI
326
327config X86_32_SMP
328	def_bool y
329	depends on X86_32 && SMP
330
331config X86_64_SMP
332	def_bool y
333	depends on X86_64 && SMP
334
335config X86_32_LAZY_GS
336	def_bool y
337	depends on X86_32 && !STACKPROTECTOR
338
339config ARCH_SUPPORTS_UPROBES
340	def_bool y
341
342config FIX_EARLYCON_MEM
343	def_bool y
344
345config DYNAMIC_PHYSICAL_MASK
346	bool
347
348config PGTABLE_LEVELS
349	int
350	default 5 if X86_5LEVEL
351	default 4 if X86_64
352	default 3 if X86_PAE
353	default 2
354
355config CC_HAS_SANE_STACKPROTECTOR
356	bool
357	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
358	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
359	help
360	   We have to make sure stack protector is unconditionally disabled if
361	   the compiler produces broken code.
362
363menu "Processor type and features"
364
365config ZONE_DMA
366	bool "DMA memory allocation support" if EXPERT
367	default y
368	help
369	  DMA memory allocation support allows devices with less than 32-bit
370	  addressing to allocate within the first 16MB of address space.
371	  Disable if no such devices will be used.
372
373	  If unsure, say Y.
374
375config SMP
376	bool "Symmetric multi-processing support"
377	---help---
378	  This enables support for systems with more than one CPU. If you have
379	  a system with only one CPU, say N. If you have a system with more
380	  than one CPU, say Y.
381
382	  If you say N here, the kernel will run on uni- and multiprocessor
383	  machines, but will use only one CPU of a multiprocessor machine. If
384	  you say Y here, the kernel will run on many, but not all,
385	  uniprocessor machines. On a uniprocessor machine, the kernel
386	  will run faster if you say N here.
387
388	  Note that if you say Y here and choose architecture "586" or
389	  "Pentium" under "Processor family", the kernel will not work on 486
390	  architectures. Similarly, multiprocessor kernels for the "PPro"
391	  architecture may not work on all Pentium based boards.
392
393	  People using multiprocessor machines who say Y here should also say
394	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
395	  Management" code will be disabled if you say Y here.
396
397	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
398	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
399	  <http://www.tldp.org/docs.html#howto>.
400
401	  If you don't know what to do here, say N.
402
403config X86_FEATURE_NAMES
404	bool "Processor feature human-readable names" if EMBEDDED
405	default y
406	---help---
407	  This option compiles in a table of x86 feature bits and corresponding
408	  names.  This is required to support /proc/cpuinfo and a few kernel
409	  messages.  You can disable this to save space, at the expense of
410	  making those few kernel messages show numeric feature bits instead.
411
412	  If in doubt, say Y.
413
414config X86_X2APIC
415	bool "Support x2apic"
416	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
417	---help---
418	  This enables x2apic support on CPUs that have this feature.
419
420	  This allows 32-bit apic IDs (so it can support very large systems),
421	  and accesses the local apic via MSRs not via mmio.
422
423	  If you don't know what to do here, say N.
424
425config X86_MPPARSE
426	bool "Enable MPS table" if ACPI || SFI
427	default y
428	depends on X86_LOCAL_APIC
429	---help---
430	  For old smp systems that do not have proper acpi support. Newer systems
431	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
432
433config GOLDFISH
434       def_bool y
435       depends on X86_GOLDFISH
436
437config RETPOLINE
438	bool "Avoid speculative indirect branches in kernel"
439	default y
440	select STACK_VALIDATION if HAVE_STACK_VALIDATION
441	help
442	  Compile kernel with the retpoline compiler options to guard against
443	  kernel-to-user data leaks by avoiding speculative indirect
444	  branches. Requires a compiler with -mindirect-branch=thunk-extern
445	  support for full protection. The kernel may run slower.
446
447	  Without compiler support, at least indirect branches in assembler
448	  code are eliminated. Since this includes the syscall entry path,
449	  it is not entirely pointless.
450
451config INTEL_RDT
452	bool "Intel Resource Director Technology support"
453	depends on X86 && CPU_SUP_INTEL
454	select KERNFS
455	help
456	  Select to enable resource allocation and monitoring which are
457	  sub-features of Intel Resource Director Technology(RDT). More
458	  information about RDT can be found in the Intel x86
459	  Architecture Software Developer Manual.
460
461	  Say N if unsure.
462
463if X86_32
464config X86_BIGSMP
465	bool "Support for big SMP systems with more than 8 CPUs"
466	depends on SMP
467	---help---
468	  This option is needed for the systems that have more than 8 CPUs
469
470config X86_EXTENDED_PLATFORM
471	bool "Support for extended (non-PC) x86 platforms"
472	default y
473	---help---
474	  If you disable this option then the kernel will only support
475	  standard PC platforms. (which covers the vast majority of
476	  systems out there.)
477
478	  If you enable this option then you'll be able to select support
479	  for the following (non-PC) 32 bit x86 platforms:
480		Goldfish (Android emulator)
481		AMD Elan
482		RDC R-321x SoC
483		SGI 320/540 (Visual Workstation)
484		STA2X11-based (e.g. Northville)
485		Moorestown MID devices
486
487	  If you have one of these systems, or if you want to build a
488	  generic distribution kernel, say Y here - otherwise say N.
489endif
490
491if X86_64
492config X86_EXTENDED_PLATFORM
493	bool "Support for extended (non-PC) x86 platforms"
494	default y
495	---help---
496	  If you disable this option then the kernel will only support
497	  standard PC platforms. (which covers the vast majority of
498	  systems out there.)
499
500	  If you enable this option then you'll be able to select support
501	  for the following (non-PC) 64 bit x86 platforms:
502		Numascale NumaChip
503		ScaleMP vSMP
504		SGI Ultraviolet
505
506	  If you have one of these systems, or if you want to build a
507	  generic distribution kernel, say Y here - otherwise say N.
508endif
509# This is an alphabetically sorted list of 64 bit extended platforms
510# Please maintain the alphabetic order if and when there are additions
511config X86_NUMACHIP
512	bool "Numascale NumaChip"
513	depends on X86_64
514	depends on X86_EXTENDED_PLATFORM
515	depends on NUMA
516	depends on SMP
517	depends on X86_X2APIC
518	depends on PCI_MMCONFIG
519	---help---
520	  Adds support for Numascale NumaChip large-SMP systems. Needed to
521	  enable more than ~168 cores.
522	  If you don't have one of these, you should say N here.
523
524config X86_VSMP
525	bool "ScaleMP vSMP"
526	select HYPERVISOR_GUEST
527	select PARAVIRT
528	depends on X86_64 && PCI
529	depends on X86_EXTENDED_PLATFORM
530	depends on SMP
531	---help---
532	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
533	  supposed to run on these EM64T-based machines.  Only choose this option
534	  if you have one of these machines.
535
536config X86_UV
537	bool "SGI Ultraviolet"
538	depends on X86_64
539	depends on X86_EXTENDED_PLATFORM
540	depends on NUMA
541	depends on EFI
542	depends on X86_X2APIC
543	depends on PCI
544	---help---
545	  This option is needed in order to support SGI Ultraviolet systems.
546	  If you don't have one of these, you should say N here.
547
548# Following is an alphabetically sorted list of 32 bit extended platforms
549# Please maintain the alphabetic order if and when there are additions
550
551config X86_GOLDFISH
552       bool "Goldfish (Virtual Platform)"
553       depends on X86_EXTENDED_PLATFORM
554       ---help---
555	 Enable support for the Goldfish virtual platform used primarily
556	 for Android development. Unless you are building for the Android
557	 Goldfish emulator say N here.
558
559config X86_INTEL_CE
560	bool "CE4100 TV platform"
561	depends on PCI
562	depends on PCI_GODIRECT
563	depends on X86_IO_APIC
564	depends on X86_32
565	depends on X86_EXTENDED_PLATFORM
566	select X86_REBOOTFIXUPS
567	select OF
568	select OF_EARLY_FLATTREE
569	---help---
570	  Select for the Intel CE media processor (CE4100) SOC.
571	  This option compiles in support for the CE4100 SOC for settop
572	  boxes and media devices.
573
574config X86_INTEL_MID
575	bool "Intel MID platform support"
576	depends on X86_EXTENDED_PLATFORM
577	depends on X86_PLATFORM_DEVICES
578	depends on PCI
579	depends on X86_64 || (PCI_GOANY && X86_32)
580	depends on X86_IO_APIC
581	select SFI
582	select I2C
583	select DW_APB_TIMER
584	select APB_TIMER
585	select INTEL_SCU_IPC
586	select MFD_INTEL_MSIC
587	---help---
588	  Select to build a kernel capable of supporting Intel MID (Mobile
589	  Internet Device) platform systems which do not have the PCI legacy
590	  interfaces. If you are building for a PC class system say N here.
591
592	  Intel MID platforms are based on an Intel processor and chipset which
593	  consume less power than most of the x86 derivatives.
594
595config X86_INTEL_QUARK
596	bool "Intel Quark platform support"
597	depends on X86_32
598	depends on X86_EXTENDED_PLATFORM
599	depends on X86_PLATFORM_DEVICES
600	depends on X86_TSC
601	depends on PCI
602	depends on PCI_GOANY
603	depends on X86_IO_APIC
604	select IOSF_MBI
605	select INTEL_IMR
606	select COMMON_CLK
607	---help---
608	  Select to include support for Quark X1000 SoC.
609	  Say Y here if you have a Quark based system such as the Arduino
610	  compatible Intel Galileo.
611
612config X86_INTEL_LPSS
613	bool "Intel Low Power Subsystem Support"
614	depends on X86 && ACPI
615	select COMMON_CLK
616	select PINCTRL
617	select IOSF_MBI
618	---help---
619	  Select to build support for Intel Low Power Subsystem such as
620	  found on Intel Lynxpoint PCH. Selecting this option enables
621	  things like clock tree (common clock framework) and pincontrol
622	  which are needed by the LPSS peripheral drivers.
623
624config X86_AMD_PLATFORM_DEVICE
625	bool "AMD ACPI2Platform devices support"
626	depends on ACPI
627	select COMMON_CLK
628	select PINCTRL
629	---help---
630	  Select to interpret AMD specific ACPI device to platform device
631	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
632	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
633	  implemented under PINCTRL subsystem.
634
635config IOSF_MBI
636	tristate "Intel SoC IOSF Sideband support for SoC platforms"
637	depends on PCI
638	---help---
639	  This option enables sideband register access support for Intel SoC
640	  platforms. On these platforms the IOSF sideband is used in lieu of
641	  MSR's for some register accesses, mostly but not limited to thermal
642	  and power. Drivers may query the availability of this device to
643	  determine if they need the sideband in order to work on these
644	  platforms. The sideband is available on the following SoC products.
645	  This list is not meant to be exclusive.
646	   - BayTrail
647	   - Braswell
648	   - Quark
649
650	  You should say Y if you are running a kernel on one of these SoC's.
651
652config IOSF_MBI_DEBUG
653	bool "Enable IOSF sideband access through debugfs"
654	depends on IOSF_MBI && DEBUG_FS
655	---help---
656	  Select this option to expose the IOSF sideband access registers (MCR,
657	  MDR, MCRX) through debugfs to write and read register information from
658	  different units on the SoC. This is most useful for obtaining device
659	  state information for debug and analysis. As this is a general access
660	  mechanism, users of this option would have specific knowledge of the
661	  device they want to access.
662
663	  If you don't require the option or are in doubt, say N.
664
665config X86_RDC321X
666	bool "RDC R-321x SoC"
667	depends on X86_32
668	depends on X86_EXTENDED_PLATFORM
669	select M486
670	select X86_REBOOTFIXUPS
671	---help---
672	  This option is needed for RDC R-321x system-on-chip, also known
673	  as R-8610-(G).
674	  If you don't have one of these chips, you should say N here.
675
676config X86_32_NON_STANDARD
677	bool "Support non-standard 32-bit SMP architectures"
678	depends on X86_32 && SMP
679	depends on X86_EXTENDED_PLATFORM
680	---help---
681	  This option compiles in the bigsmp and STA2X11 default
682	  subarchitectures.  It is intended for a generic binary
683	  kernel. If you select them all, kernel will probe it one by
684	  one and will fallback to default.
685
686# Alphabetically sorted list of Non standard 32 bit platforms
687
688config X86_SUPPORTS_MEMORY_FAILURE
689	def_bool y
690	# MCE code calls memory_failure():
691	depends on X86_MCE
692	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
693	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
694	depends on X86_64 || !SPARSEMEM
695	select ARCH_SUPPORTS_MEMORY_FAILURE
696
697config STA2X11
698	bool "STA2X11 Companion Chip Support"
699	depends on X86_32_NON_STANDARD && PCI
700	select ARCH_HAS_PHYS_TO_DMA
701	select X86_DEV_DMA_OPS
702	select X86_DMA_REMAP
703	select SWIOTLB
704	select MFD_STA2X11
705	select GPIOLIB
706	---help---
707	  This adds support for boards based on the STA2X11 IO-Hub,
708	  a.k.a. "ConneXt". The chip is used in place of the standard
709	  PC chipset, so all "standard" peripherals are missing. If this
710	  option is selected the kernel will still be able to boot on
711	  standard PC machines.
712
713config X86_32_IRIS
714	tristate "Eurobraille/Iris poweroff module"
715	depends on X86_32
716	---help---
717	  The Iris machines from EuroBraille do not have APM or ACPI support
718	  to shut themselves down properly.  A special I/O sequence is
719	  needed to do so, which is what this module does at
720	  kernel shutdown.
721
722	  This is only for Iris machines from EuroBraille.
723
724	  If unused, say N.
725
726config SCHED_OMIT_FRAME_POINTER
727	def_bool y
728	prompt "Single-depth WCHAN output"
729	depends on X86
730	---help---
731	  Calculate simpler /proc/<PID>/wchan values. If this option
732	  is disabled then wchan values will recurse back to the
733	  caller function. This provides more accurate wchan values,
734	  at the expense of slightly more scheduling overhead.
735
736	  If in doubt, say "Y".
737
738menuconfig HYPERVISOR_GUEST
739	bool "Linux guest support"
740	---help---
741	  Say Y here to enable options for running Linux under various hyper-
742	  visors. This option enables basic hypervisor detection and platform
743	  setup.
744
745	  If you say N, all options in this submenu will be skipped and
746	  disabled, and Linux guest support won't be built in.
747
748if HYPERVISOR_GUEST
749
750config PARAVIRT
751	bool "Enable paravirtualization code"
752	---help---
753	  This changes the kernel so it can modify itself when it is run
754	  under a hypervisor, potentially improving performance significantly
755	  over full virtualization.  However, when run without a hypervisor
756	  the kernel is theoretically slower and slightly larger.
757
758config PARAVIRT_XXL
759	bool
760
761config PARAVIRT_DEBUG
762	bool "paravirt-ops debugging"
763	depends on PARAVIRT && DEBUG_KERNEL
764	---help---
765	  Enable to debug paravirt_ops internals.  Specifically, BUG if
766	  a paravirt_op is missing when it is called.
767
768config PARAVIRT_SPINLOCKS
769	bool "Paravirtualization layer for spinlocks"
770	depends on PARAVIRT && SMP
771	---help---
772	  Paravirtualized spinlocks allow a pvops backend to replace the
773	  spinlock implementation with something virtualization-friendly
774	  (for example, block the virtual CPU rather than spinning).
775
776	  It has a minimal impact on native kernels and gives a nice performance
777	  benefit on paravirtualized KVM / Xen kernels.
778
779	  If you are unsure how to answer this question, answer Y.
780
781config QUEUED_LOCK_STAT
782	bool "Paravirt queued spinlock statistics"
783	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
784	---help---
785	  Enable the collection of statistical data on the slowpath
786	  behavior of paravirtualized queued spinlocks and report
787	  them on debugfs.
788
789source "arch/x86/xen/Kconfig"
790
791config KVM_GUEST
792	bool "KVM Guest support (including kvmclock)"
793	depends on PARAVIRT
794	select PARAVIRT_CLOCK
795	default y
796	---help---
797	  This option enables various optimizations for running under the KVM
798	  hypervisor. It includes a paravirtualized clock, so that instead
799	  of relying on a PIT (or probably other) emulation by the
800	  underlying device model, the host provides the guest with
801	  timing infrastructure such as time of day, and system time
802
803config KVM_DEBUG_FS
804	bool "Enable debug information for KVM Guests in debugfs"
805	depends on KVM_GUEST && DEBUG_FS
806	---help---
807	  This option enables collection of various statistics for KVM guest.
808	  Statistics are displayed in debugfs filesystem. Enabling this option
809	  may incur significant overhead.
810
811config PARAVIRT_TIME_ACCOUNTING
812	bool "Paravirtual steal time accounting"
813	depends on PARAVIRT
814	---help---
815	  Select this option to enable fine granularity task steal time
816	  accounting. Time spent executing other tasks in parallel with
817	  the current vCPU is discounted from the vCPU power. To account for
818	  that, there can be a small performance impact.
819
820	  If in doubt, say N here.
821
822config PARAVIRT_CLOCK
823	bool
824
825config JAILHOUSE_GUEST
826	bool "Jailhouse non-root cell support"
827	depends on X86_64 && PCI
828	select X86_PM_TIMER
829	---help---
830	  This option allows to run Linux as guest in a Jailhouse non-root
831	  cell. You can leave this option disabled if you only want to start
832	  Jailhouse and run Linux afterwards in the root cell.
833
834endif #HYPERVISOR_GUEST
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	depends on X86_32
1171	---help---
1172	  This option allows user programs to put the CPU into V8086
1173	  mode, which is an 80286-era approximation of 16-bit real mode.
1174
1175	  Some very old versions of X and/or vbetool require this option
1176	  for user mode setting.  Similarly, DOSEMU will use it if
1177	  available to accelerate real mode DOS programs.  However, any
1178	  recent version of DOSEMU, X, or vbetool should be fully
1179	  functional even without kernel VM86 support, as they will all
1180	  fall back to software emulation. Nevertheless, if you are using
1181	  a 16-bit DOS program where 16-bit performance matters, vm86
1182	  mode might be faster than emulation and you might want to
1183	  enable this option.
1184
1185	  Note that any app that works on a 64-bit kernel is unlikely to
1186	  need this option, as 64-bit kernels don't, and can't, support
1187	  V8086 mode. This option is also unrelated to 16-bit protected
1188	  mode and is not needed to run most 16-bit programs under Wine.
1189
1190	  Enabling this option increases the complexity of the kernel
1191	  and slows down exception handling a tiny bit.
1192
1193	  If unsure, say N here.
1194
1195config VM86
1196       bool
1197       default X86_LEGACY_VM86
1198
1199config X86_16BIT
1200	bool "Enable support for 16-bit segments" if EXPERT
1201	default y
1202	depends on MODIFY_LDT_SYSCALL
1203	---help---
1204	  This option is required by programs like Wine to run 16-bit
1205	  protected mode legacy code on x86 processors.  Disabling
1206	  this option saves about 300 bytes on i386, or around 6K text
1207	  plus 16K runtime memory on x86-64,
1208
1209config X86_ESPFIX32
1210	def_bool y
1211	depends on X86_16BIT && X86_32
1212
1213config X86_ESPFIX64
1214	def_bool y
1215	depends on X86_16BIT && X86_64
1216
1217config X86_VSYSCALL_EMULATION
1218       bool "Enable vsyscall emulation" if EXPERT
1219       default y
1220       depends on X86_64
1221       ---help---
1222	 This enables emulation of the legacy vsyscall page.  Disabling
1223	 it is roughly equivalent to booting with vsyscall=none, except
1224	 that it will also disable the helpful warning if a program
1225	 tries to use a vsyscall.  With this option set to N, offending
1226	 programs will just segfault, citing addresses of the form
1227	 0xffffffffff600?00.
1228
1229	 This option is required by many programs built before 2013, and
1230	 care should be used even with newer programs if set to N.
1231
1232	 Disabling this option saves about 7K of kernel size and
1233	 possibly 4K of additional runtime pagetable memory.
1234
1235config TOSHIBA
1236	tristate "Toshiba Laptop support"
1237	depends on X86_32
1238	---help---
1239	  This adds a driver to safely access the System Management Mode of
1240	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1241	  not work on models with a Phoenix BIOS. The System Management Mode
1242	  is used to set the BIOS and power saving options on Toshiba portables.
1243
1244	  For information on utilities to make use of this driver see the
1245	  Toshiba Linux utilities web site at:
1246	  <http://www.buzzard.org.uk/toshiba/>.
1247
1248	  Say Y if you intend to run this kernel on a Toshiba portable.
1249	  Say N otherwise.
1250
1251config I8K
1252	tristate "Dell i8k legacy laptop support"
1253	select HWMON
1254	select SENSORS_DELL_SMM
1255	---help---
1256	  This option enables legacy /proc/i8k userspace interface in hwmon
1257	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1258	  temperature and allows controlling fan speeds of Dell laptops via
1259	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1260	  it reports also power and hotkey status. For fan speed control is
1261	  needed userspace package i8kutils.
1262
1263	  Say Y if you intend to run this kernel on old Dell laptops or want to
1264	  use userspace package i8kutils.
1265	  Say N otherwise.
1266
1267config X86_REBOOTFIXUPS
1268	bool "Enable X86 board specific fixups for reboot"
1269	depends on X86_32
1270	---help---
1271	  This enables chipset and/or board specific fixups to be done
1272	  in order to get reboot to work correctly. This is only needed on
1273	  some combinations of hardware and BIOS. The symptom, for which
1274	  this config is intended, is when reboot ends with a stalled/hung
1275	  system.
1276
1277	  Currently, the only fixup is for the Geode machines using
1278	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1279
1280	  Say Y if you want to enable the fixup. Currently, it's safe to
1281	  enable this option even if you don't need it.
1282	  Say N otherwise.
1283
1284config MICROCODE
1285	bool "CPU microcode loading support"
1286	default y
1287	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1288	select FW_LOADER
1289	---help---
1290	  If you say Y here, you will be able to update the microcode on
1291	  Intel and AMD processors. The Intel support is for the IA32 family,
1292	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1293	  AMD support is for families 0x10 and later. You will obviously need
1294	  the actual microcode binary data itself which is not shipped with
1295	  the Linux kernel.
1296
1297	  The preferred method to load microcode from a detached initrd is described
1298	  in Documentation/x86/microcode.txt. For that you need to enable
1299	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1300	  initrd for microcode blobs.
1301
1302	  In addition, you can build the microcode into the kernel. For that you
1303	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1304	  config option.
1305
1306config MICROCODE_INTEL
1307	bool "Intel microcode loading support"
1308	depends on MICROCODE
1309	default MICROCODE
1310	select FW_LOADER
1311	---help---
1312	  This options enables microcode patch loading support for Intel
1313	  processors.
1314
1315	  For the current Intel microcode data package go to
1316	  <https://downloadcenter.intel.com> and search for
1317	  'Linux Processor Microcode Data File'.
1318
1319config MICROCODE_AMD
1320	bool "AMD microcode loading support"
1321	depends on MICROCODE
1322	select FW_LOADER
1323	---help---
1324	  If you select this option, microcode patch loading support for AMD
1325	  processors will be enabled.
1326
1327config MICROCODE_OLD_INTERFACE
1328	def_bool y
1329	depends on MICROCODE
1330
1331config X86_MSR
1332	tristate "/dev/cpu/*/msr - Model-specific register support"
1333	---help---
1334	  This device gives privileged processes access to the x86
1335	  Model-Specific Registers (MSRs).  It is a character device with
1336	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1337	  MSR accesses are directed to a specific CPU on multi-processor
1338	  systems.
1339
1340config X86_CPUID
1341	tristate "/dev/cpu/*/cpuid - CPU information support"
1342	---help---
1343	  This device gives processes access to the x86 CPUID instruction to
1344	  be executed on a specific processor.  It is a character device
1345	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1346	  /dev/cpu/31/cpuid.
1347
1348choice
1349	prompt "High Memory Support"
1350	default HIGHMEM4G
1351	depends on X86_32
1352
1353config NOHIGHMEM
1354	bool "off"
1355	---help---
1356	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1357	  However, the address space of 32-bit x86 processors is only 4
1358	  Gigabytes large. That means that, if you have a large amount of
1359	  physical memory, not all of it can be "permanently mapped" by the
1360	  kernel. The physical memory that's not permanently mapped is called
1361	  "high memory".
1362
1363	  If you are compiling a kernel which will never run on a machine with
1364	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1365	  choice and suitable for most users). This will result in a "3GB/1GB"
1366	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1367	  space and the remaining part of the 4GB virtual memory space is used
1368	  by the kernel to permanently map as much physical memory as
1369	  possible.
1370
1371	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1372	  answer "4GB" here.
1373
1374	  If more than 4 Gigabytes is used then answer "64GB" here. This
1375	  selection turns Intel PAE (Physical Address Extension) mode on.
1376	  PAE implements 3-level paging on IA32 processors. PAE is fully
1377	  supported by Linux, PAE mode is implemented on all recent Intel
1378	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1379	  then the kernel will not boot on CPUs that don't support PAE!
1380
1381	  The actual amount of total physical memory will either be
1382	  auto detected or can be forced by using a kernel command line option
1383	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1384	  your boot loader (lilo or loadlin) about how to pass options to the
1385	  kernel at boot time.)
1386
1387	  If unsure, say "off".
1388
1389config HIGHMEM4G
1390	bool "4GB"
1391	---help---
1392	  Select this if you have a 32-bit processor and between 1 and 4
1393	  gigabytes of physical RAM.
1394
1395config HIGHMEM64G
1396	bool "64GB"
1397	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1398	select X86_PAE
1399	---help---
1400	  Select this if you have a 32-bit processor and more than 4
1401	  gigabytes of physical RAM.
1402
1403endchoice
1404
1405choice
1406	prompt "Memory split" if EXPERT
1407	default VMSPLIT_3G
1408	depends on X86_32
1409	---help---
1410	  Select the desired split between kernel and user memory.
1411
1412	  If the address range available to the kernel is less than the
1413	  physical memory installed, the remaining memory will be available
1414	  as "high memory". Accessing high memory is a little more costly
1415	  than low memory, as it needs to be mapped into the kernel first.
1416	  Note that increasing the kernel address space limits the range
1417	  available to user programs, making the address space there
1418	  tighter.  Selecting anything other than the default 3G/1G split
1419	  will also likely make your kernel incompatible with binary-only
1420	  kernel modules.
1421
1422	  If you are not absolutely sure what you are doing, leave this
1423	  option alone!
1424
1425	config VMSPLIT_3G
1426		bool "3G/1G user/kernel split"
1427	config VMSPLIT_3G_OPT
1428		depends on !X86_PAE
1429		bool "3G/1G user/kernel split (for full 1G low memory)"
1430	config VMSPLIT_2G
1431		bool "2G/2G user/kernel split"
1432	config VMSPLIT_2G_OPT
1433		depends on !X86_PAE
1434		bool "2G/2G user/kernel split (for full 2G low memory)"
1435	config VMSPLIT_1G
1436		bool "1G/3G user/kernel split"
1437endchoice
1438
1439config PAGE_OFFSET
1440	hex
1441	default 0xB0000000 if VMSPLIT_3G_OPT
1442	default 0x80000000 if VMSPLIT_2G
1443	default 0x78000000 if VMSPLIT_2G_OPT
1444	default 0x40000000 if VMSPLIT_1G
1445	default 0xC0000000
1446	depends on X86_32
1447
1448config HIGHMEM
1449	def_bool y
1450	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1451
1452config X86_PAE
1453	bool "PAE (Physical Address Extension) Support"
1454	depends on X86_32 && !HIGHMEM4G
1455	select PHYS_ADDR_T_64BIT
1456	select SWIOTLB
1457	---help---
1458	  PAE is required for NX support, and furthermore enables
1459	  larger swapspace support for non-overcommit purposes. It
1460	  has the cost of more pagetable lookup overhead, and also
1461	  consumes more pagetable space per process.
1462
1463config X86_5LEVEL
1464	bool "Enable 5-level page tables support"
1465	select DYNAMIC_MEMORY_LAYOUT
1466	select SPARSEMEM_VMEMMAP
1467	depends on X86_64
1468	---help---
1469	  5-level paging enables access to larger address space:
1470	  upto 128 PiB of virtual address space and 4 PiB of
1471	  physical address space.
1472
1473	  It will be supported by future Intel CPUs.
1474
1475	  A kernel with the option enabled can be booted on machines that
1476	  support 4- or 5-level paging.
1477
1478	  See Documentation/x86/x86_64/5level-paging.txt for more
1479	  information.
1480
1481	  Say N if unsure.
1482
1483config X86_DIRECT_GBPAGES
1484	def_bool y
1485	depends on X86_64 && !DEBUG_PAGEALLOC
1486	---help---
1487	  Certain kernel features effectively disable kernel
1488	  linear 1 GB mappings (even if the CPU otherwise
1489	  supports them), so don't confuse the user by printing
1490	  that we have them enabled.
1491
1492config X86_CPA_STATISTICS
1493	bool "Enable statistic for Change Page Attribute"
1494	depends on DEBUG_FS
1495	---help---
1496	  Expose statistics about the Change Page Attribute mechanims, which
1497	  helps to determine the effectivness of preserving large and huge
1498	  page mappings when mapping protections are changed.
1499
1500config ARCH_HAS_MEM_ENCRYPT
1501	def_bool y
1502
1503config AMD_MEM_ENCRYPT
1504	bool "AMD Secure Memory Encryption (SME) support"
1505	depends on X86_64 && CPU_SUP_AMD
1506	select DYNAMIC_PHYSICAL_MASK
1507	---help---
1508	  Say yes to enable support for the encryption of system memory.
1509	  This requires an AMD processor that supports Secure Memory
1510	  Encryption (SME).
1511
1512config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1513	bool "Activate AMD Secure Memory Encryption (SME) by default"
1514	default y
1515	depends on AMD_MEM_ENCRYPT
1516	---help---
1517	  Say yes to have system memory encrypted by default if running on
1518	  an AMD processor that supports Secure Memory Encryption (SME).
1519
1520	  If set to Y, then the encryption of system memory can be
1521	  deactivated with the mem_encrypt=off command line option.
1522
1523	  If set to N, then the encryption of system memory can be
1524	  activated with the mem_encrypt=on command line option.
1525
1526config ARCH_USE_MEMREMAP_PROT
1527	def_bool y
1528	depends on AMD_MEM_ENCRYPT
1529
1530# Common NUMA Features
1531config NUMA
1532	bool "Numa Memory Allocation and Scheduler Support"
1533	depends on SMP
1534	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1535	default y if X86_BIGSMP
1536	---help---
1537	  Enable NUMA (Non Uniform Memory Access) support.
1538
1539	  The kernel will try to allocate memory used by a CPU on the
1540	  local memory controller of the CPU and add some more
1541	  NUMA awareness to the kernel.
1542
1543	  For 64-bit this is recommended if the system is Intel Core i7
1544	  (or later), AMD Opteron, or EM64T NUMA.
1545
1546	  For 32-bit this is only needed if you boot a 32-bit
1547	  kernel on a 64-bit NUMA platform.
1548
1549	  Otherwise, you should say N.
1550
1551config AMD_NUMA
1552	def_bool y
1553	prompt "Old style AMD Opteron NUMA detection"
1554	depends on X86_64 && NUMA && PCI
1555	---help---
1556	  Enable AMD NUMA node topology detection.  You should say Y here if
1557	  you have a multi processor AMD system. This uses an old method to
1558	  read the NUMA configuration directly from the builtin Northbridge
1559	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1560	  which also takes priority if both are compiled in.
1561
1562config X86_64_ACPI_NUMA
1563	def_bool y
1564	prompt "ACPI NUMA detection"
1565	depends on X86_64 && NUMA && ACPI && PCI
1566	select ACPI_NUMA
1567	---help---
1568	  Enable ACPI SRAT based node topology detection.
1569
1570# Some NUMA nodes have memory ranges that span
1571# other nodes.  Even though a pfn is valid and
1572# between a node's start and end pfns, it may not
1573# reside on that node.  See memmap_init_zone()
1574# for details.
1575config NODES_SPAN_OTHER_NODES
1576	def_bool y
1577	depends on X86_64_ACPI_NUMA
1578
1579config NUMA_EMU
1580	bool "NUMA emulation"
1581	depends on NUMA
1582	---help---
1583	  Enable NUMA emulation. A flat machine will be split
1584	  into virtual nodes when booted with "numa=fake=N", where N is the
1585	  number of nodes. This is only useful for debugging.
1586
1587config NODES_SHIFT
1588	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1589	range 1 10
1590	default "10" if MAXSMP
1591	default "6" if X86_64
1592	default "3"
1593	depends on NEED_MULTIPLE_NODES
1594	---help---
1595	  Specify the maximum number of NUMA Nodes available on the target
1596	  system.  Increases memory reserved to accommodate various tables.
1597
1598config ARCH_HAVE_MEMORY_PRESENT
1599	def_bool y
1600	depends on X86_32 && DISCONTIGMEM
1601
1602config ARCH_FLATMEM_ENABLE
1603	def_bool y
1604	depends on X86_32 && !NUMA
1605
1606config ARCH_DISCONTIGMEM_ENABLE
1607	def_bool y
1608	depends on NUMA && X86_32
1609
1610config ARCH_DISCONTIGMEM_DEFAULT
1611	def_bool y
1612	depends on NUMA && X86_32
1613
1614config ARCH_SPARSEMEM_ENABLE
1615	def_bool y
1616	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1617	select SPARSEMEM_STATIC if X86_32
1618	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1619
1620config ARCH_SPARSEMEM_DEFAULT
1621	def_bool y
1622	depends on X86_64
1623
1624config ARCH_SELECT_MEMORY_MODEL
1625	def_bool y
1626	depends on ARCH_SPARSEMEM_ENABLE
1627
1628config ARCH_MEMORY_PROBE
1629	bool "Enable sysfs memory/probe interface"
1630	depends on X86_64 && MEMORY_HOTPLUG
1631	help
1632	  This option enables a sysfs memory/probe interface for testing.
1633	  See Documentation/memory-hotplug.txt for more information.
1634	  If you are unsure how to answer this question, answer N.
1635
1636config ARCH_PROC_KCORE_TEXT
1637	def_bool y
1638	depends on X86_64 && PROC_KCORE
1639
1640config ILLEGAL_POINTER_VALUE
1641       hex
1642       default 0 if X86_32
1643       default 0xdead000000000000 if X86_64
1644
1645config X86_PMEM_LEGACY_DEVICE
1646	bool
1647
1648config X86_PMEM_LEGACY
1649	tristate "Support non-standard NVDIMMs and ADR protected memory"
1650	depends on PHYS_ADDR_T_64BIT
1651	depends on BLK_DEV
1652	select X86_PMEM_LEGACY_DEVICE
1653	select LIBNVDIMM
1654	help
1655	  Treat memory marked using the non-standard e820 type of 12 as used
1656	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1657	  The kernel will offer these regions to the 'pmem' driver so
1658	  they can be used for persistent storage.
1659
1660	  Say Y if unsure.
1661
1662config HIGHPTE
1663	bool "Allocate 3rd-level pagetables from highmem"
1664	depends on HIGHMEM
1665	---help---
1666	  The VM uses one page table entry for each page of physical memory.
1667	  For systems with a lot of RAM, this can be wasteful of precious
1668	  low memory.  Setting this option will put user-space page table
1669	  entries in high memory.
1670
1671config X86_CHECK_BIOS_CORRUPTION
1672	bool "Check for low memory corruption"
1673	---help---
1674	  Periodically check for memory corruption in low memory, which
1675	  is suspected to be caused by BIOS.  Even when enabled in the
1676	  configuration, it is disabled at runtime.  Enable it by
1677	  setting "memory_corruption_check=1" on the kernel command
1678	  line.  By default it scans the low 64k of memory every 60
1679	  seconds; see the memory_corruption_check_size and
1680	  memory_corruption_check_period parameters in
1681	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1682
1683	  When enabled with the default parameters, this option has
1684	  almost no overhead, as it reserves a relatively small amount
1685	  of memory and scans it infrequently.  It both detects corruption
1686	  and prevents it from affecting the running system.
1687
1688	  It is, however, intended as a diagnostic tool; if repeatable
1689	  BIOS-originated corruption always affects the same memory,
1690	  you can use memmap= to prevent the kernel from using that
1691	  memory.
1692
1693config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1694	bool "Set the default setting of memory_corruption_check"
1695	depends on X86_CHECK_BIOS_CORRUPTION
1696	default y
1697	---help---
1698	  Set whether the default state of memory_corruption_check is
1699	  on or off.
1700
1701config X86_RESERVE_LOW
1702	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1703	default 64
1704	range 4 640
1705	---help---
1706	  Specify the amount of low memory to reserve for the BIOS.
1707
1708	  The first page contains BIOS data structures that the kernel
1709	  must not use, so that page must always be reserved.
1710
1711	  By default we reserve the first 64K of physical RAM, as a
1712	  number of BIOSes are known to corrupt that memory range
1713	  during events such as suspend/resume or monitor cable
1714	  insertion, so it must not be used by the kernel.
1715
1716	  You can set this to 4 if you are absolutely sure that you
1717	  trust the BIOS to get all its memory reservations and usages
1718	  right.  If you know your BIOS have problems beyond the
1719	  default 64K area, you can set this to 640 to avoid using the
1720	  entire low memory range.
1721
1722	  If you have doubts about the BIOS (e.g. suspend/resume does
1723	  not work or there's kernel crashes after certain hardware
1724	  hotplug events) then you might want to enable
1725	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1726	  typical corruption patterns.
1727
1728	  Leave this to the default value of 64 if you are unsure.
1729
1730config MATH_EMULATION
1731	bool
1732	depends on MODIFY_LDT_SYSCALL
1733	prompt "Math emulation" if X86_32
1734	---help---
1735	  Linux can emulate a math coprocessor (used for floating point
1736	  operations) if you don't have one. 486DX and Pentium processors have
1737	  a math coprocessor built in, 486SX and 386 do not, unless you added
1738	  a 487DX or 387, respectively. (The messages during boot time can
1739	  give you some hints here ["man dmesg"].) Everyone needs either a
1740	  coprocessor or this emulation.
1741
1742	  If you don't have a math coprocessor, you need to say Y here; if you
1743	  say Y here even though you have a coprocessor, the coprocessor will
1744	  be used nevertheless. (This behavior can be changed with the kernel
1745	  command line option "no387", which comes handy if your coprocessor
1746	  is broken. Try "man bootparam" or see the documentation of your boot
1747	  loader (lilo or loadlin) about how to pass options to the kernel at
1748	  boot time.) This means that it is a good idea to say Y here if you
1749	  intend to use this kernel on different machines.
1750
1751	  More information about the internals of the Linux math coprocessor
1752	  emulation can be found in <file:arch/x86/math-emu/README>.
1753
1754	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1755	  kernel, it won't hurt.
1756
1757config MTRR
1758	def_bool y
1759	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1760	---help---
1761	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1762	  the Memory Type Range Registers (MTRRs) may be used to control
1763	  processor access to memory ranges. This is most useful if you have
1764	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1765	  allows bus write transfers to be combined into a larger transfer
1766	  before bursting over the PCI/AGP bus. This can increase performance
1767	  of image write operations 2.5 times or more. Saying Y here creates a
1768	  /proc/mtrr file which may be used to manipulate your processor's
1769	  MTRRs. Typically the X server should use this.
1770
1771	  This code has a reasonably generic interface so that similar
1772	  control registers on other processors can be easily supported
1773	  as well:
1774
1775	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1776	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1777	  these, the ARRs are used to emulate the MTRRs.
1778	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1779	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1780	  write-combining. All of these processors are supported by this code
1781	  and it makes sense to say Y here if you have one of them.
1782
1783	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1784	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1785	  can lead to all sorts of problems, so it's good to say Y here.
1786
1787	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1788	  just add about 9 KB to your kernel.
1789
1790	  See <file:Documentation/x86/mtrr.txt> for more information.
1791
1792config MTRR_SANITIZER
1793	def_bool y
1794	prompt "MTRR cleanup support"
1795	depends on MTRR
1796	---help---
1797	  Convert MTRR layout from continuous to discrete, so X drivers can
1798	  add writeback entries.
1799
1800	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1801	  The largest mtrr entry size for a continuous block can be set with
1802	  mtrr_chunk_size.
1803
1804	  If unsure, say Y.
1805
1806config MTRR_SANITIZER_ENABLE_DEFAULT
1807	int "MTRR cleanup enable value (0-1)"
1808	range 0 1
1809	default "0"
1810	depends on MTRR_SANITIZER
1811	---help---
1812	  Enable mtrr cleanup default value
1813
1814config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1815	int "MTRR cleanup spare reg num (0-7)"
1816	range 0 7
1817	default "1"
1818	depends on MTRR_SANITIZER
1819	---help---
1820	  mtrr cleanup spare entries default, it can be changed via
1821	  mtrr_spare_reg_nr=N on the kernel command line.
1822
1823config X86_PAT
1824	def_bool y
1825	prompt "x86 PAT support" if EXPERT
1826	depends on MTRR
1827	---help---
1828	  Use PAT attributes to setup page level cache control.
1829
1830	  PATs are the modern equivalents of MTRRs and are much more
1831	  flexible than MTRRs.
1832
1833	  Say N here if you see bootup problems (boot crash, boot hang,
1834	  spontaneous reboots) or a non-working video driver.
1835
1836	  If unsure, say Y.
1837
1838config ARCH_USES_PG_UNCACHED
1839	def_bool y
1840	depends on X86_PAT
1841
1842config ARCH_RANDOM
1843	def_bool y
1844	prompt "x86 architectural random number generator" if EXPERT
1845	---help---
1846	  Enable the x86 architectural RDRAND instruction
1847	  (Intel Bull Mountain technology) to generate random numbers.
1848	  If supported, this is a high bandwidth, cryptographically
1849	  secure hardware random number generator.
1850
1851config X86_SMAP
1852	def_bool y
1853	prompt "Supervisor Mode Access Prevention" if EXPERT
1854	---help---
1855	  Supervisor Mode Access Prevention (SMAP) is a security
1856	  feature in newer Intel processors.  There is a small
1857	  performance cost if this enabled and turned on; there is
1858	  also a small increase in the kernel size if this is enabled.
1859
1860	  If unsure, say Y.
1861
1862config X86_INTEL_UMIP
1863	def_bool y
1864	depends on CPU_SUP_INTEL
1865	prompt "Intel User Mode Instruction Prevention" if EXPERT
1866	---help---
1867	  The User Mode Instruction Prevention (UMIP) is a security
1868	  feature in newer Intel processors. If enabled, a general
1869	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1870	  or STR instructions are executed in user mode. These instructions
1871	  unnecessarily expose information about the hardware state.
1872
1873	  The vast majority of applications do not use these instructions.
1874	  For the very few that do, software emulation is provided in
1875	  specific cases in protected and virtual-8086 modes. Emulated
1876	  results are dummy.
1877
1878config X86_INTEL_MPX
1879	prompt "Intel MPX (Memory Protection Extensions)"
1880	def_bool n
1881	# Note: only available in 64-bit mode due to VMA flags shortage
1882	depends on CPU_SUP_INTEL && X86_64
1883	select ARCH_USES_HIGH_VMA_FLAGS
1884	---help---
1885	  MPX provides hardware features that can be used in
1886	  conjunction with compiler-instrumented code to check
1887	  memory references.  It is designed to detect buffer
1888	  overflow or underflow bugs.
1889
1890	  This option enables running applications which are
1891	  instrumented or otherwise use MPX.  It does not use MPX
1892	  itself inside the kernel or to protect the kernel
1893	  against bad memory references.
1894
1895	  Enabling this option will make the kernel larger:
1896	  ~8k of kernel text and 36 bytes of data on a 64-bit
1897	  defconfig.  It adds a long to the 'mm_struct' which
1898	  will increase the kernel memory overhead of each
1899	  process and adds some branches to paths used during
1900	  exec() and munmap().
1901
1902	  For details, see Documentation/x86/intel_mpx.txt
1903
1904	  If unsure, say N.
1905
1906config X86_INTEL_MEMORY_PROTECTION_KEYS
1907	prompt "Intel Memory Protection Keys"
1908	def_bool y
1909	# Note: only available in 64-bit mode
1910	depends on CPU_SUP_INTEL && X86_64
1911	select ARCH_USES_HIGH_VMA_FLAGS
1912	select ARCH_HAS_PKEYS
1913	---help---
1914	  Memory Protection Keys provides a mechanism for enforcing
1915	  page-based protections, but without requiring modification of the
1916	  page tables when an application changes protection domains.
1917
1918	  For details, see Documentation/x86/protection-keys.txt
1919
1920	  If unsure, say y.
1921
1922config EFI
1923	bool "EFI runtime service support"
1924	depends on ACPI
1925	select UCS2_STRING
1926	select EFI_RUNTIME_WRAPPERS
1927	---help---
1928	  This enables the kernel to use EFI runtime services that are
1929	  available (such as the EFI variable services).
1930
1931	  This option is only useful on systems that have EFI firmware.
1932	  In addition, you should use the latest ELILO loader available
1933	  at <http://elilo.sourceforge.net> in order to take advantage
1934	  of EFI runtime services. However, even with this option, the
1935	  resultant kernel should continue to boot on existing non-EFI
1936	  platforms.
1937
1938config EFI_STUB
1939       bool "EFI stub support"
1940       depends on EFI && !X86_USE_3DNOW
1941       select RELOCATABLE
1942       ---help---
1943          This kernel feature allows a bzImage to be loaded directly
1944	  by EFI firmware without the use of a bootloader.
1945
1946	  See Documentation/efi-stub.txt for more information.
1947
1948config EFI_MIXED
1949	bool "EFI mixed-mode support"
1950	depends on EFI_STUB && X86_64
1951	---help---
1952	   Enabling this feature allows a 64-bit kernel to be booted
1953	   on a 32-bit firmware, provided that your CPU supports 64-bit
1954	   mode.
1955
1956	   Note that it is not possible to boot a mixed-mode enabled
1957	   kernel via the EFI boot stub - a bootloader that supports
1958	   the EFI handover protocol must be used.
1959
1960	   If unsure, say N.
1961
1962config SECCOMP
1963	def_bool y
1964	prompt "Enable seccomp to safely compute untrusted bytecode"
1965	---help---
1966	  This kernel feature is useful for number crunching applications
1967	  that may need to compute untrusted bytecode during their
1968	  execution. By using pipes or other transports made available to
1969	  the process as file descriptors supporting the read/write
1970	  syscalls, it's possible to isolate those applications in
1971	  their own address space using seccomp. Once seccomp is
1972	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1973	  and the task is only allowed to execute a few safe syscalls
1974	  defined by each seccomp mode.
1975
1976	  If unsure, say Y. Only embedded should say N here.
1977
1978source kernel/Kconfig.hz
1979
1980config KEXEC
1981	bool "kexec system call"
1982	select KEXEC_CORE
1983	---help---
1984	  kexec is a system call that implements the ability to shutdown your
1985	  current kernel, and to start another kernel.  It is like a reboot
1986	  but it is independent of the system firmware.   And like a reboot
1987	  you can start any kernel with it, not just Linux.
1988
1989	  The name comes from the similarity to the exec system call.
1990
1991	  It is an ongoing process to be certain the hardware in a machine
1992	  is properly shutdown, so do not be surprised if this code does not
1993	  initially work for you.  As of this writing the exact hardware
1994	  interface is strongly in flux, so no good recommendation can be
1995	  made.
1996
1997config KEXEC_FILE
1998	bool "kexec file based system call"
1999	select KEXEC_CORE
2000	select BUILD_BIN2C
2001	depends on X86_64
2002	depends on CRYPTO=y
2003	depends on CRYPTO_SHA256=y
2004	---help---
2005	  This is new version of kexec system call. This system call is
2006	  file based and takes file descriptors as system call argument
2007	  for kernel and initramfs as opposed to list of segments as
2008	  accepted by previous system call.
2009
2010config ARCH_HAS_KEXEC_PURGATORY
2011	def_bool KEXEC_FILE
2012
2013config KEXEC_VERIFY_SIG
2014	bool "Verify kernel signature during kexec_file_load() syscall"
2015	depends on KEXEC_FILE
2016	---help---
2017	  This option makes kernel signature verification mandatory for
2018	  the kexec_file_load() syscall.
2019
2020	  In addition to that option, you need to enable signature
2021	  verification for the corresponding kernel image type being
2022	  loaded in order for this to work.
2023
2024config KEXEC_BZIMAGE_VERIFY_SIG
2025	bool "Enable bzImage signature verification support"
2026	depends on KEXEC_VERIFY_SIG
2027	depends on SIGNED_PE_FILE_VERIFICATION
2028	select SYSTEM_TRUSTED_KEYRING
2029	---help---
2030	  Enable bzImage signature verification support.
2031
2032config CRASH_DUMP
2033	bool "kernel crash dumps"
2034	depends on X86_64 || (X86_32 && HIGHMEM)
2035	---help---
2036	  Generate crash dump after being started by kexec.
2037	  This should be normally only set in special crash dump kernels
2038	  which are loaded in the main kernel with kexec-tools into
2039	  a specially reserved region and then later executed after
2040	  a crash by kdump/kexec. The crash dump kernel must be compiled
2041	  to a memory address not used by the main kernel or BIOS using
2042	  PHYSICAL_START, or it must be built as a relocatable image
2043	  (CONFIG_RELOCATABLE=y).
2044	  For more details see Documentation/kdump/kdump.txt
2045
2046config KEXEC_JUMP
2047	bool "kexec jump"
2048	depends on KEXEC && HIBERNATION
2049	---help---
2050	  Jump between original kernel and kexeced kernel and invoke
2051	  code in physical address mode via KEXEC
2052
2053config PHYSICAL_START
2054	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2055	default "0x1000000"
2056	---help---
2057	  This gives the physical address where the kernel is loaded.
2058
2059	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2060	  bzImage will decompress itself to above physical address and
2061	  run from there. Otherwise, bzImage will run from the address where
2062	  it has been loaded by the boot loader and will ignore above physical
2063	  address.
2064
2065	  In normal kdump cases one does not have to set/change this option
2066	  as now bzImage can be compiled as a completely relocatable image
2067	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2068	  address. This option is mainly useful for the folks who don't want
2069	  to use a bzImage for capturing the crash dump and want to use a
2070	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2071	  to be specifically compiled to run from a specific memory area
2072	  (normally a reserved region) and this option comes handy.
2073
2074	  So if you are using bzImage for capturing the crash dump,
2075	  leave the value here unchanged to 0x1000000 and set
2076	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2077	  for capturing the crash dump change this value to start of
2078	  the reserved region.  In other words, it can be set based on
2079	  the "X" value as specified in the "crashkernel=YM@XM"
2080	  command line boot parameter passed to the panic-ed
2081	  kernel. Please take a look at Documentation/kdump/kdump.txt
2082	  for more details about crash dumps.
2083
2084	  Usage of bzImage for capturing the crash dump is recommended as
2085	  one does not have to build two kernels. Same kernel can be used
2086	  as production kernel and capture kernel. Above option should have
2087	  gone away after relocatable bzImage support is introduced. But it
2088	  is present because there are users out there who continue to use
2089	  vmlinux for dump capture. This option should go away down the
2090	  line.
2091
2092	  Don't change this unless you know what you are doing.
2093
2094config RELOCATABLE
2095	bool "Build a relocatable kernel"
2096	default y
2097	---help---
2098	  This builds a kernel image that retains relocation information
2099	  so it can be loaded someplace besides the default 1MB.
2100	  The relocations tend to make the kernel binary about 10% larger,
2101	  but are discarded at runtime.
2102
2103	  One use is for the kexec on panic case where the recovery kernel
2104	  must live at a different physical address than the primary
2105	  kernel.
2106
2107	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2108	  it has been loaded at and the compile time physical address
2109	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2110
2111config RANDOMIZE_BASE
2112	bool "Randomize the address of the kernel image (KASLR)"
2113	depends on RELOCATABLE
2114	default y
2115	---help---
2116	  In support of Kernel Address Space Layout Randomization (KASLR),
2117	  this randomizes the physical address at which the kernel image
2118	  is decompressed and the virtual address where the kernel
2119	  image is mapped, as a security feature that deters exploit
2120	  attempts relying on knowledge of the location of kernel
2121	  code internals.
2122
2123	  On 64-bit, the kernel physical and virtual addresses are
2124	  randomized separately. The physical address will be anywhere
2125	  between 16MB and the top of physical memory (up to 64TB). The
2126	  virtual address will be randomized from 16MB up to 1GB (9 bits
2127	  of entropy). Note that this also reduces the memory space
2128	  available to kernel modules from 1.5GB to 1GB.
2129
2130	  On 32-bit, the kernel physical and virtual addresses are
2131	  randomized together. They will be randomized from 16MB up to
2132	  512MB (8 bits of entropy).
2133
2134	  Entropy is generated using the RDRAND instruction if it is
2135	  supported. If RDTSC is supported, its value is mixed into
2136	  the entropy pool as well. If neither RDRAND nor RDTSC are
2137	  supported, then entropy is read from the i8254 timer. The
2138	  usable entropy is limited by the kernel being built using
2139	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2140	  minimum of 2MB. As a result, only 10 bits of entropy are
2141	  theoretically possible, but the implementations are further
2142	  limited due to memory layouts.
2143
2144	  If unsure, say Y.
2145
2146# Relocation on x86 needs some additional build support
2147config X86_NEED_RELOCS
2148	def_bool y
2149	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2150
2151config PHYSICAL_ALIGN
2152	hex "Alignment value to which kernel should be aligned"
2153	default "0x200000"
2154	range 0x2000 0x1000000 if X86_32
2155	range 0x200000 0x1000000 if X86_64
2156	---help---
2157	  This value puts the alignment restrictions on physical address
2158	  where kernel is loaded and run from. Kernel is compiled for an
2159	  address which meets above alignment restriction.
2160
2161	  If bootloader loads the kernel at a non-aligned address and
2162	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2163	  address aligned to above value and run from there.
2164
2165	  If bootloader loads the kernel at a non-aligned address and
2166	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2167	  load address and decompress itself to the address it has been
2168	  compiled for and run from there. The address for which kernel is
2169	  compiled already meets above alignment restrictions. Hence the
2170	  end result is that kernel runs from a physical address meeting
2171	  above alignment restrictions.
2172
2173	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2174	  this value must be a multiple of 0x200000.
2175
2176	  Don't change this unless you know what you are doing.
2177
2178config DYNAMIC_MEMORY_LAYOUT
2179	bool
2180	---help---
2181	  This option makes base addresses of vmalloc and vmemmap as well as
2182	  __PAGE_OFFSET movable during boot.
2183
2184config RANDOMIZE_MEMORY
2185	bool "Randomize the kernel memory sections"
2186	depends on X86_64
2187	depends on RANDOMIZE_BASE
2188	select DYNAMIC_MEMORY_LAYOUT
2189	default RANDOMIZE_BASE
2190	---help---
2191	   Randomizes the base virtual address of kernel memory sections
2192	   (physical memory mapping, vmalloc & vmemmap). This security feature
2193	   makes exploits relying on predictable memory locations less reliable.
2194
2195	   The order of allocations remains unchanged. Entropy is generated in
2196	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2197	   configuration have in average 30,000 different possible virtual
2198	   addresses for each memory section.
2199
2200	   If unsure, say Y.
2201
2202config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2203	hex "Physical memory mapping padding" if EXPERT
2204	depends on RANDOMIZE_MEMORY
2205	default "0xa" if MEMORY_HOTPLUG
2206	default "0x0"
2207	range 0x1 0x40 if MEMORY_HOTPLUG
2208	range 0x0 0x40
2209	---help---
2210	   Define the padding in terabytes added to the existing physical
2211	   memory size during kernel memory randomization. It is useful
2212	   for memory hotplug support but reduces the entropy available for
2213	   address randomization.
2214
2215	   If unsure, leave at the default value.
2216
2217config HOTPLUG_CPU
2218	bool "Support for hot-pluggable CPUs"
2219	depends on SMP
2220	---help---
2221	  Say Y here to allow turning CPUs off and on. CPUs can be
2222	  controlled through /sys/devices/system/cpu.
2223	  ( Note: power management support will enable this option
2224	    automatically on SMP systems. )
2225	  Say N if you want to disable CPU hotplug.
2226
2227config BOOTPARAM_HOTPLUG_CPU0
2228	bool "Set default setting of cpu0_hotpluggable"
2229	depends on HOTPLUG_CPU
2230	---help---
2231	  Set whether default state of cpu0_hotpluggable is on or off.
2232
2233	  Say Y here to enable CPU0 hotplug by default. If this switch
2234	  is turned on, there is no need to give cpu0_hotplug kernel
2235	  parameter and the CPU0 hotplug feature is enabled by default.
2236
2237	  Please note: there are two known CPU0 dependencies if you want
2238	  to enable the CPU0 hotplug feature either by this switch or by
2239	  cpu0_hotplug kernel parameter.
2240
2241	  First, resume from hibernate or suspend always starts from CPU0.
2242	  So hibernate and suspend are prevented if CPU0 is offline.
2243
2244	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2245	  offline if any interrupt can not migrate out of CPU0. There may
2246	  be other CPU0 dependencies.
2247
2248	  Please make sure the dependencies are under your control before
2249	  you enable this feature.
2250
2251	  Say N if you don't want to enable CPU0 hotplug feature by default.
2252	  You still can enable the CPU0 hotplug feature at boot by kernel
2253	  parameter cpu0_hotplug.
2254
2255config DEBUG_HOTPLUG_CPU0
2256	def_bool n
2257	prompt "Debug CPU0 hotplug"
2258	depends on HOTPLUG_CPU
2259	---help---
2260	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2261	  soon as possible and boots up userspace with CPU0 offlined. User
2262	  can online CPU0 back after boot time.
2263
2264	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2265	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2266	  compilation or giving cpu0_hotplug kernel parameter at boot.
2267
2268	  If unsure, say N.
2269
2270config COMPAT_VDSO
2271	def_bool n
2272	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2273	depends on COMPAT_32
2274	---help---
2275	  Certain buggy versions of glibc will crash if they are
2276	  presented with a 32-bit vDSO that is not mapped at the address
2277	  indicated in its segment table.
2278
2279	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2280	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2281	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2282	  the only released version with the bug, but OpenSUSE 9
2283	  contains a buggy "glibc 2.3.2".
2284
2285	  The symptom of the bug is that everything crashes on startup, saying:
2286	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2287
2288	  Saying Y here changes the default value of the vdso32 boot
2289	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2290	  This works around the glibc bug but hurts performance.
2291
2292	  If unsure, say N: if you are compiling your own kernel, you
2293	  are unlikely to be using a buggy version of glibc.
2294
2295choice
2296	prompt "vsyscall table for legacy applications"
2297	depends on X86_64
2298	default LEGACY_VSYSCALL_EMULATE
2299	help
2300	  Legacy user code that does not know how to find the vDSO expects
2301	  to be able to issue three syscalls by calling fixed addresses in
2302	  kernel space. Since this location is not randomized with ASLR,
2303	  it can be used to assist security vulnerability exploitation.
2304
2305	  This setting can be changed at boot time via the kernel command
2306	  line parameter vsyscall=[emulate|none].
2307
2308	  On a system with recent enough glibc (2.14 or newer) and no
2309	  static binaries, you can say None without a performance penalty
2310	  to improve security.
2311
2312	  If unsure, select "Emulate".
2313
2314	config LEGACY_VSYSCALL_EMULATE
2315		bool "Emulate"
2316		help
2317		  The kernel traps and emulates calls into the fixed
2318		  vsyscall address mapping. This makes the mapping
2319		  non-executable, but it still contains known contents,
2320		  which could be used in certain rare security vulnerability
2321		  exploits. This configuration is recommended when userspace
2322		  still uses the vsyscall area.
2323
2324	config LEGACY_VSYSCALL_NONE
2325		bool "None"
2326		help
2327		  There will be no vsyscall mapping at all. This will
2328		  eliminate any risk of ASLR bypass due to the vsyscall
2329		  fixed address mapping. Attempts to use the vsyscalls
2330		  will be reported to dmesg, so that either old or
2331		  malicious userspace programs can be identified.
2332
2333endchoice
2334
2335config CMDLINE_BOOL
2336	bool "Built-in kernel command line"
2337	---help---
2338	  Allow for specifying boot arguments to the kernel at
2339	  build time.  On some systems (e.g. embedded ones), it is
2340	  necessary or convenient to provide some or all of the
2341	  kernel boot arguments with the kernel itself (that is,
2342	  to not rely on the boot loader to provide them.)
2343
2344	  To compile command line arguments into the kernel,
2345	  set this option to 'Y', then fill in the
2346	  boot arguments in CONFIG_CMDLINE.
2347
2348	  Systems with fully functional boot loaders (i.e. non-embedded)
2349	  should leave this option set to 'N'.
2350
2351config CMDLINE
2352	string "Built-in kernel command string"
2353	depends on CMDLINE_BOOL
2354	default ""
2355	---help---
2356	  Enter arguments here that should be compiled into the kernel
2357	  image and used at boot time.  If the boot loader provides a
2358	  command line at boot time, it is appended to this string to
2359	  form the full kernel command line, when the system boots.
2360
2361	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2362	  change this behavior.
2363
2364	  In most cases, the command line (whether built-in or provided
2365	  by the boot loader) should specify the device for the root
2366	  file system.
2367
2368config CMDLINE_OVERRIDE
2369	bool "Built-in command line overrides boot loader arguments"
2370	depends on CMDLINE_BOOL
2371	---help---
2372	  Set this option to 'Y' to have the kernel ignore the boot loader
2373	  command line, and use ONLY the built-in command line.
2374
2375	  This is used to work around broken boot loaders.  This should
2376	  be set to 'N' under normal conditions.
2377
2378config MODIFY_LDT_SYSCALL
2379	bool "Enable the LDT (local descriptor table)" if EXPERT
2380	default y
2381	---help---
2382	  Linux can allow user programs to install a per-process x86
2383	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2384	  call.  This is required to run 16-bit or segmented code such as
2385	  DOSEMU or some Wine programs.  It is also used by some very old
2386	  threading libraries.
2387
2388	  Enabling this feature adds a small amount of overhead to
2389	  context switches and increases the low-level kernel attack
2390	  surface.  Disabling it removes the modify_ldt(2) system call.
2391
2392	  Saying 'N' here may make sense for embedded or server kernels.
2393
2394source "kernel/livepatch/Kconfig"
2395
2396endmenu
2397
2398config ARCH_HAS_ADD_PAGES
2399	def_bool y
2400	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2401
2402config ARCH_ENABLE_MEMORY_HOTPLUG
2403	def_bool y
2404	depends on X86_64 || (X86_32 && HIGHMEM)
2405
2406config ARCH_ENABLE_MEMORY_HOTREMOVE
2407	def_bool y
2408	depends on MEMORY_HOTPLUG
2409
2410config USE_PERCPU_NUMA_NODE_ID
2411	def_bool y
2412	depends on NUMA
2413
2414config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2415	def_bool y
2416	depends on X86_64 || X86_PAE
2417
2418config ARCH_ENABLE_HUGEPAGE_MIGRATION
2419	def_bool y
2420	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2421
2422config ARCH_ENABLE_THP_MIGRATION
2423	def_bool y
2424	depends on X86_64 && TRANSPARENT_HUGEPAGE
2425
2426menu "Power management and ACPI options"
2427
2428config ARCH_HIBERNATION_HEADER
2429	def_bool y
2430	depends on HIBERNATION
2431
2432source "kernel/power/Kconfig"
2433
2434source "drivers/acpi/Kconfig"
2435
2436source "drivers/sfi/Kconfig"
2437
2438config X86_APM_BOOT
2439	def_bool y
2440	depends on APM
2441
2442menuconfig APM
2443	tristate "APM (Advanced Power Management) BIOS support"
2444	depends on X86_32 && PM_SLEEP
2445	---help---
2446	  APM is a BIOS specification for saving power using several different
2447	  techniques. This is mostly useful for battery powered laptops with
2448	  APM compliant BIOSes. If you say Y here, the system time will be
2449	  reset after a RESUME operation, the /proc/apm device will provide
2450	  battery status information, and user-space programs will receive
2451	  notification of APM "events" (e.g. battery status change).
2452
2453	  If you select "Y" here, you can disable actual use of the APM
2454	  BIOS by passing the "apm=off" option to the kernel at boot time.
2455
2456	  Note that the APM support is almost completely disabled for
2457	  machines with more than one CPU.
2458
2459	  In order to use APM, you will need supporting software. For location
2460	  and more information, read <file:Documentation/power/apm-acpi.txt>
2461	  and the Battery Powered Linux mini-HOWTO, available from
2462	  <http://www.tldp.org/docs.html#howto>.
2463
2464	  This driver does not spin down disk drives (see the hdparm(8)
2465	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2466	  VESA-compliant "green" monitors.
2467
2468	  This driver does not support the TI 4000M TravelMate and the ACER
2469	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2470	  desktop machines also don't have compliant BIOSes, and this driver
2471	  may cause those machines to panic during the boot phase.
2472
2473	  Generally, if you don't have a battery in your machine, there isn't
2474	  much point in using this driver and you should say N. If you get
2475	  random kernel OOPSes or reboots that don't seem to be related to
2476	  anything, try disabling/enabling this option (or disabling/enabling
2477	  APM in your BIOS).
2478
2479	  Some other things you should try when experiencing seemingly random,
2480	  "weird" problems:
2481
2482	  1) make sure that you have enough swap space and that it is
2483	  enabled.
2484	  2) pass the "no-hlt" option to the kernel
2485	  3) switch on floating point emulation in the kernel and pass
2486	  the "no387" option to the kernel
2487	  4) pass the "floppy=nodma" option to the kernel
2488	  5) pass the "mem=4M" option to the kernel (thereby disabling
2489	  all but the first 4 MB of RAM)
2490	  6) make sure that the CPU is not over clocked.
2491	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2492	  8) disable the cache from your BIOS settings
2493	  9) install a fan for the video card or exchange video RAM
2494	  10) install a better fan for the CPU
2495	  11) exchange RAM chips
2496	  12) exchange the motherboard.
2497
2498	  To compile this driver as a module, choose M here: the
2499	  module will be called apm.
2500
2501if APM
2502
2503config APM_IGNORE_USER_SUSPEND
2504	bool "Ignore USER SUSPEND"
2505	---help---
2506	  This option will ignore USER SUSPEND requests. On machines with a
2507	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2508	  series notebooks, it is necessary to say Y because of a BIOS bug.
2509
2510config APM_DO_ENABLE
2511	bool "Enable PM at boot time"
2512	---help---
2513	  Enable APM features at boot time. From page 36 of the APM BIOS
2514	  specification: "When disabled, the APM BIOS does not automatically
2515	  power manage devices, enter the Standby State, enter the Suspend
2516	  State, or take power saving steps in response to CPU Idle calls."
2517	  This driver will make CPU Idle calls when Linux is idle (unless this
2518	  feature is turned off -- see "Do CPU IDLE calls", below). This
2519	  should always save battery power, but more complicated APM features
2520	  will be dependent on your BIOS implementation. You may need to turn
2521	  this option off if your computer hangs at boot time when using APM
2522	  support, or if it beeps continuously instead of suspending. Turn
2523	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2524	  T400CDT. This is off by default since most machines do fine without
2525	  this feature.
2526
2527config APM_CPU_IDLE
2528	depends on CPU_IDLE
2529	bool "Make CPU Idle calls when idle"
2530	---help---
2531	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2532	  On some machines, this can activate improved power savings, such as
2533	  a slowed CPU clock rate, when the machine is idle. These idle calls
2534	  are made after the idle loop has run for some length of time (e.g.,
2535	  333 mS). On some machines, this will cause a hang at boot time or
2536	  whenever the CPU becomes idle. (On machines with more than one CPU,
2537	  this option does nothing.)
2538
2539config APM_DISPLAY_BLANK
2540	bool "Enable console blanking using APM"
2541	---help---
2542	  Enable console blanking using the APM. Some laptops can use this to
2543	  turn off the LCD backlight when the screen blanker of the Linux
2544	  virtual console blanks the screen. Note that this is only used by
2545	  the virtual console screen blanker, and won't turn off the backlight
2546	  when using the X Window system. This also doesn't have anything to
2547	  do with your VESA-compliant power-saving monitor. Further, this
2548	  option doesn't work for all laptops -- it might not turn off your
2549	  backlight at all, or it might print a lot of errors to the console,
2550	  especially if you are using gpm.
2551
2552config APM_ALLOW_INTS
2553	bool "Allow interrupts during APM BIOS calls"
2554	---help---
2555	  Normally we disable external interrupts while we are making calls to
2556	  the APM BIOS as a measure to lessen the effects of a badly behaving
2557	  BIOS implementation.  The BIOS should reenable interrupts if it
2558	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2559	  many of the newer IBM Thinkpads.  If you experience hangs when you
2560	  suspend, try setting this to Y.  Otherwise, say N.
2561
2562endif # APM
2563
2564source "drivers/cpufreq/Kconfig"
2565
2566source "drivers/cpuidle/Kconfig"
2567
2568source "drivers/idle/Kconfig"
2569
2570endmenu
2571
2572
2573menu "Bus options (PCI etc.)"
2574
2575config PCI
2576	bool "PCI support"
2577	default y
2578	---help---
2579	  Find out whether you have a PCI motherboard. PCI is the name of a
2580	  bus system, i.e. the way the CPU talks to the other stuff inside
2581	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2582	  VESA. If you have PCI, say Y, otherwise N.
2583
2584choice
2585	prompt "PCI access mode"
2586	depends on X86_32 && PCI
2587	default PCI_GOANY
2588	---help---
2589	  On PCI systems, the BIOS can be used to detect the PCI devices and
2590	  determine their configuration. However, some old PCI motherboards
2591	  have BIOS bugs and may crash if this is done. Also, some embedded
2592	  PCI-based systems don't have any BIOS at all. Linux can also try to
2593	  detect the PCI hardware directly without using the BIOS.
2594
2595	  With this option, you can specify how Linux should detect the
2596	  PCI devices. If you choose "BIOS", the BIOS will be used,
2597	  if you choose "Direct", the BIOS won't be used, and if you
2598	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2599	  If you choose "Any", the kernel will try MMCONFIG, then the
2600	  direct access method and falls back to the BIOS if that doesn't
2601	  work. If unsure, go with the default, which is "Any".
2602
2603config PCI_GOBIOS
2604	bool "BIOS"
2605
2606config PCI_GOMMCONFIG
2607	bool "MMConfig"
2608
2609config PCI_GODIRECT
2610	bool "Direct"
2611
2612config PCI_GOOLPC
2613	bool "OLPC XO-1"
2614	depends on OLPC
2615
2616config PCI_GOANY
2617	bool "Any"
2618
2619endchoice
2620
2621config PCI_BIOS
2622	def_bool y
2623	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2624
2625# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2626config PCI_DIRECT
2627	def_bool y
2628	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2629
2630config PCI_MMCONFIG
2631	bool "Support mmconfig PCI config space access" if X86_64
2632	default y
2633	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2634	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2635
2636config PCI_OLPC
2637	def_bool y
2638	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2639
2640config PCI_XEN
2641	def_bool y
2642	depends on PCI && XEN
2643	select SWIOTLB_XEN
2644
2645config PCI_DOMAINS
2646	def_bool y
2647	depends on PCI
2648
2649config MMCONF_FAM10H
2650	def_bool y
2651	depends on X86_64 && PCI_MMCONFIG && ACPI
2652
2653config PCI_CNB20LE_QUIRK
2654	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2655	depends on PCI
2656	help
2657	  Read the PCI windows out of the CNB20LE host bridge. This allows
2658	  PCI hotplug to work on systems with the CNB20LE chipset which do
2659	  not have ACPI.
2660
2661	  There's no public spec for this chipset, and this functionality
2662	  is known to be incomplete.
2663
2664	  You should say N unless you know you need this.
2665
2666source "drivers/pci/Kconfig"
2667
2668config ISA_BUS
2669	bool "ISA bus support on modern systems" if EXPERT
2670	help
2671	  Expose ISA bus device drivers and options available for selection and
2672	  configuration. Enable this option if your target machine has an ISA
2673	  bus. ISA is an older system, displaced by PCI and newer bus
2674	  architectures -- if your target machine is modern, it probably does
2675	  not have an ISA bus.
2676
2677	  If unsure, say N.
2678
2679# x86_64 have no ISA slots, but can have ISA-style DMA.
2680config ISA_DMA_API
2681	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2682	default y
2683	help
2684	  Enables ISA-style DMA support for devices requiring such controllers.
2685	  If unsure, say Y.
2686
2687if X86_32
2688
2689config ISA
2690	bool "ISA support"
2691	---help---
2692	  Find out whether you have ISA slots on your motherboard.  ISA is the
2693	  name of a bus system, i.e. the way the CPU talks to the other stuff
2694	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2695	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2696	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2697
2698config EISA
2699	bool "EISA support"
2700	depends on ISA
2701	---help---
2702	  The Extended Industry Standard Architecture (EISA) bus was
2703	  developed as an open alternative to the IBM MicroChannel bus.
2704
2705	  The EISA bus provided some of the features of the IBM MicroChannel
2706	  bus while maintaining backward compatibility with cards made for
2707	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2708	  1995 when it was made obsolete by the PCI bus.
2709
2710	  Say Y here if you are building a kernel for an EISA-based machine.
2711
2712	  Otherwise, say N.
2713
2714source "drivers/eisa/Kconfig"
2715
2716config SCx200
2717	tristate "NatSemi SCx200 support"
2718	---help---
2719	  This provides basic support for National Semiconductor's
2720	  (now AMD's) Geode processors.  The driver probes for the
2721	  PCI-IDs of several on-chip devices, so its a good dependency
2722	  for other scx200_* drivers.
2723
2724	  If compiled as a module, the driver is named scx200.
2725
2726config SCx200HR_TIMER
2727	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2728	depends on SCx200
2729	default y
2730	---help---
2731	  This driver provides a clocksource built upon the on-chip
2732	  27MHz high-resolution timer.  Its also a workaround for
2733	  NSC Geode SC-1100's buggy TSC, which loses time when the
2734	  processor goes idle (as is done by the scheduler).  The
2735	  other workaround is idle=poll boot option.
2736
2737config OLPC
2738	bool "One Laptop Per Child support"
2739	depends on !X86_PAE
2740	select GPIOLIB
2741	select OF
2742	select OF_PROMTREE
2743	select IRQ_DOMAIN
2744	---help---
2745	  Add support for detecting the unique features of the OLPC
2746	  XO hardware.
2747
2748config OLPC_XO1_PM
2749	bool "OLPC XO-1 Power Management"
2750	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2751	---help---
2752	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2753
2754config OLPC_XO1_RTC
2755	bool "OLPC XO-1 Real Time Clock"
2756	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2757	---help---
2758	  Add support for the XO-1 real time clock, which can be used as a
2759	  programmable wakeup source.
2760
2761config OLPC_XO1_SCI
2762	bool "OLPC XO-1 SCI extras"
2763	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2764	depends on INPUT=y
2765	select POWER_SUPPLY
2766	---help---
2767	  Add support for SCI-based features of the OLPC XO-1 laptop:
2768	   - EC-driven system wakeups
2769	   - Power button
2770	   - Ebook switch
2771	   - Lid switch
2772	   - AC adapter status updates
2773	   - Battery status updates
2774
2775config OLPC_XO15_SCI
2776	bool "OLPC XO-1.5 SCI extras"
2777	depends on OLPC && ACPI
2778	select POWER_SUPPLY
2779	---help---
2780	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2781	   - EC-driven system wakeups
2782	   - AC adapter status updates
2783	   - Battery status updates
2784
2785config ALIX
2786	bool "PCEngines ALIX System Support (LED setup)"
2787	select GPIOLIB
2788	---help---
2789	  This option enables system support for the PCEngines ALIX.
2790	  At present this just sets up LEDs for GPIO control on
2791	  ALIX2/3/6 boards.  However, other system specific setup should
2792	  get added here.
2793
2794	  Note: You must still enable the drivers for GPIO and LED support
2795	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2796
2797	  Note: You have to set alix.force=1 for boards with Award BIOS.
2798
2799config NET5501
2800	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2801	select GPIOLIB
2802	---help---
2803	  This option enables system support for the Soekris Engineering net5501.
2804
2805config GEOS
2806	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2807	select GPIOLIB
2808	depends on DMI
2809	---help---
2810	  This option enables system support for the Traverse Technologies GEOS.
2811
2812config TS5500
2813	bool "Technologic Systems TS-5500 platform support"
2814	depends on MELAN
2815	select CHECK_SIGNATURE
2816	select NEW_LEDS
2817	select LEDS_CLASS
2818	---help---
2819	  This option enables system support for the Technologic Systems TS-5500.
2820
2821endif # X86_32
2822
2823config AMD_NB
2824	def_bool y
2825	depends on CPU_SUP_AMD && PCI
2826
2827source "drivers/pcmcia/Kconfig"
2828
2829config RAPIDIO
2830	tristate "RapidIO support"
2831	depends on PCI
2832	help
2833	  If enabled this option will include drivers and the core
2834	  infrastructure code to support RapidIO interconnect devices.
2835
2836source "drivers/rapidio/Kconfig"
2837
2838config X86_SYSFB
2839	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2840	help
2841	  Firmwares often provide initial graphics framebuffers so the BIOS,
2842	  bootloader or kernel can show basic video-output during boot for
2843	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2844	  Extensions and EFI-framebuffers for this, which are mostly limited
2845	  to x86.
2846	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2847	  framebuffers so the new generic system-framebuffer drivers can be
2848	  used on x86. If the framebuffer is not compatible with the generic
2849	  modes, it is advertised as fallback platform framebuffer so legacy
2850	  drivers like efifb, vesafb and uvesafb can pick it up.
2851	  If this option is not selected, all system framebuffers are always
2852	  marked as fallback platform framebuffers as usual.
2853
2854	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2855	  not be able to pick up generic system framebuffers if this option
2856	  is selected. You are highly encouraged to enable simplefb as
2857	  replacement if you select this option. simplefb can correctly deal
2858	  with generic system framebuffers. But you should still keep vesafb
2859	  and others enabled as fallback if a system framebuffer is
2860	  incompatible with simplefb.
2861
2862	  If unsure, say Y.
2863
2864endmenu
2865
2866
2867menu "Binary Emulations"
2868
2869config IA32_EMULATION
2870	bool "IA32 Emulation"
2871	depends on X86_64
2872	select ARCH_WANT_OLD_COMPAT_IPC
2873	select BINFMT_ELF
2874	select COMPAT_BINFMT_ELF
2875	select COMPAT_OLD_SIGACTION
2876	---help---
2877	  Include code to run legacy 32-bit programs under a
2878	  64-bit kernel. You should likely turn this on, unless you're
2879	  100% sure that you don't have any 32-bit programs left.
2880
2881config IA32_AOUT
2882	tristate "IA32 a.out support"
2883	depends on IA32_EMULATION
2884	---help---
2885	  Support old a.out binaries in the 32bit emulation.
2886
2887config X86_X32
2888	bool "x32 ABI for 64-bit mode"
2889	depends on X86_64
2890	---help---
2891	  Include code to run binaries for the x32 native 32-bit ABI
2892	  for 64-bit processors.  An x32 process gets access to the
2893	  full 64-bit register file and wide data path while leaving
2894	  pointers at 32 bits for smaller memory footprint.
2895
2896	  You will need a recent binutils (2.22 or later) with
2897	  elf32_x86_64 support enabled to compile a kernel with this
2898	  option set.
2899
2900config COMPAT_32
2901	def_bool y
2902	depends on IA32_EMULATION || X86_32
2903	select HAVE_UID16
2904	select OLD_SIGSUSPEND3
2905
2906config COMPAT
2907	def_bool y
2908	depends on IA32_EMULATION || X86_X32
2909
2910if COMPAT
2911config COMPAT_FOR_U64_ALIGNMENT
2912	def_bool y
2913
2914config SYSVIPC_COMPAT
2915	def_bool y
2916	depends on SYSVIPC
2917endif
2918
2919endmenu
2920
2921
2922config HAVE_ATOMIC_IOMAP
2923	def_bool y
2924	depends on X86_32
2925
2926config X86_DEV_DMA_OPS
2927	bool
2928	depends on X86_64 || STA2X11
2929
2930config X86_DMA_REMAP
2931	bool
2932	depends on STA2X11
2933
2934config HAVE_GENERIC_GUP
2935	def_bool y
2936
2937source "drivers/firmware/Kconfig"
2938
2939source "arch/x86/kvm/Kconfig"
2940