xref: /openbmc/linux/arch/x86/Kconfig (revision 838f9bc0)
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_DEBUG_STACKOVERFLOW
18	select MODULES_USE_ELF_REL
19	select OLD_SIGACTION
20	select GENERIC_VDSO_32
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
27	select ARCH_SUPPORTS_INT128 if CC_HAS_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
34config FORCE_DYNAMIC_FTRACE
35	def_bool y
36	depends on X86_32
37	depends on FUNCTION_TRACER
38	select DYNAMIC_FTRACE
39	help
40	 We keep the static function tracing (!DYNAMIC_FTRACE) around
41	 in order to test the non static function tracing in the
42	 generic code, as other architectures still use it. But we
43	 only need to keep it around for x86_64. No need to keep it
44	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
45#
46# Arch settings
47#
48# ( Note that options that are marked 'if X86_64' could in principle be
49#   ported to 32-bit as well. )
50#
51config X86
52	def_bool y
53	#
54	# Note: keep this list sorted alphabetically
55	#
56	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
57	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
58	select ARCH_32BIT_OFF_T			if X86_32
59	select ARCH_CLOCKSOURCE_INIT
60	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
61	select ARCH_HAS_DEBUG_VIRTUAL
62	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
63	select ARCH_HAS_DEVMEM_IS_ALLOWED
64	select ARCH_HAS_EARLY_DEBUG		if KGDB
65	select ARCH_HAS_ELF_RANDOMIZE
66	select ARCH_HAS_FAST_MULTIPLIER
67	select ARCH_HAS_FILTER_PGPROT
68	select ARCH_HAS_FORTIFY_SOURCE
69	select ARCH_HAS_GCOV_PROFILE_ALL
70	select ARCH_HAS_KCOV			if X86_64
71	select ARCH_HAS_MEM_ENCRYPT
72	select ARCH_HAS_MEMBARRIER_SYNC_CORE
73	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
74	select ARCH_HAS_PMEM_API		if X86_64
75	select ARCH_HAS_PTE_DEVMAP		if X86_64
76	select ARCH_HAS_PTE_SPECIAL
77	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
78	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
79	select ARCH_HAS_SET_MEMORY
80	select ARCH_HAS_SET_DIRECT_MAP
81	select ARCH_HAS_STRICT_KERNEL_RWX
82	select ARCH_HAS_STRICT_MODULE_RWX
83	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
84	select ARCH_HAS_SYSCALL_WRAPPER
85	select ARCH_HAS_UBSAN_SANITIZE_ALL
86	select ARCH_HAS_DEBUG_WX
87	select ARCH_HAVE_NMI_SAFE_CMPXCHG
88	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
89	select ARCH_MIGHT_HAVE_PC_PARPORT
90	select ARCH_MIGHT_HAVE_PC_SERIO
91	select ARCH_STACKWALK
92	select ARCH_SUPPORTS_ACPI
93	select ARCH_SUPPORTS_ATOMIC_RMW
94	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
95	select ARCH_USE_BUILTIN_BSWAP
96	select ARCH_USE_QUEUED_RWLOCKS
97	select ARCH_USE_QUEUED_SPINLOCKS
98	select ARCH_USE_SYM_ANNOTATIONS
99	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
100	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
101	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
102	select ARCH_WANT_HUGE_PMD_SHARE
103	select ARCH_WANTS_THP_SWAP		if X86_64
104	select BUILDTIME_TABLE_SORT
105	select CLKEVT_I8253
106	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107	select CLOCKSOURCE_WATCHDOG
108	select DCACHE_WORD_ACCESS
109	select EDAC_ATOMIC_SCRUB
110	select EDAC_SUPPORT
111	select GENERIC_CLOCKEVENTS
112	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
113	select GENERIC_CLOCKEVENTS_MIN_ADJUST
114	select GENERIC_CMOS_UPDATE
115	select GENERIC_CPU_AUTOPROBE
116	select GENERIC_CPU_VULNERABILITIES
117	select GENERIC_EARLY_IOREMAP
118	select GENERIC_FIND_FIRST_BIT
119	select GENERIC_IOMAP
120	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
121	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
122	select GENERIC_IRQ_MIGRATION		if SMP
123	select GENERIC_IRQ_PROBE
124	select GENERIC_IRQ_RESERVATION_MODE
125	select GENERIC_IRQ_SHOW
126	select GENERIC_PENDING_IRQ		if SMP
127	select GENERIC_PTDUMP
128	select GENERIC_SMP_IDLE_THREAD
129	select GENERIC_STRNCPY_FROM_USER
130	select GENERIC_STRNLEN_USER
131	select GENERIC_TIME_VSYSCALL
132	select GENERIC_GETTIMEOFDAY
133	select GENERIC_VDSO_TIME_NS
134	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
135	select HARDIRQS_SW_RESEND
136	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
137	select HAVE_ACPI_APEI			if ACPI
138	select HAVE_ACPI_APEI_NMI		if ACPI
139	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
140	select HAVE_ARCH_AUDITSYSCALL
141	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
142	select HAVE_ARCH_JUMP_LABEL
143	select HAVE_ARCH_JUMP_LABEL_RELATIVE
144	select HAVE_ARCH_KASAN			if X86_64
145	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
146	select HAVE_ARCH_KGDB
147	select HAVE_ARCH_MMAP_RND_BITS		if MMU
148	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
149	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
150	select HAVE_ARCH_PREL32_RELOCATIONS
151	select HAVE_ARCH_SECCOMP_FILTER
152	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
153	select HAVE_ARCH_STACKLEAK
154	select HAVE_ARCH_TRACEHOOK
155	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
156	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
157	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
158	select HAVE_ARCH_VMAP_STACK		if X86_64
159	select HAVE_ARCH_WITHIN_STACK_FRAMES
160	select HAVE_ASM_MODVERSIONS
161	select HAVE_CMPXCHG_DOUBLE
162	select HAVE_CMPXCHG_LOCAL
163	select HAVE_CONTEXT_TRACKING		if X86_64
164	select HAVE_COPY_THREAD_TLS
165	select HAVE_C_RECORDMCOUNT
166	select HAVE_DEBUG_KMEMLEAK
167	select HAVE_DMA_CONTIGUOUS
168	select HAVE_DYNAMIC_FTRACE
169	select HAVE_DYNAMIC_FTRACE_WITH_REGS
170	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
171	select HAVE_EBPF_JIT
172	select HAVE_EFFICIENT_UNALIGNED_ACCESS
173	select HAVE_EISA
174	select HAVE_EXIT_THREAD
175	select HAVE_FAST_GUP
176	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
177	select HAVE_FTRACE_MCOUNT_RECORD
178	select HAVE_FUNCTION_GRAPH_TRACER
179	select HAVE_FUNCTION_TRACER
180	select HAVE_GCC_PLUGINS
181	select HAVE_HW_BREAKPOINT
182	select HAVE_IDE
183	select HAVE_IOREMAP_PROT
184	select HAVE_IRQ_TIME_ACCOUNTING
185	select HAVE_KERNEL_BZIP2
186	select HAVE_KERNEL_GZIP
187	select HAVE_KERNEL_LZ4
188	select HAVE_KERNEL_LZMA
189	select HAVE_KERNEL_LZO
190	select HAVE_KERNEL_XZ
191	select HAVE_KPROBES
192	select HAVE_KPROBES_ON_FTRACE
193	select HAVE_FUNCTION_ERROR_INJECTION
194	select HAVE_KRETPROBES
195	select HAVE_KVM
196	select HAVE_LIVEPATCH			if X86_64
197	select HAVE_MIXED_BREAKPOINTS_REGS
198	select HAVE_MOD_ARCH_SPECIFIC
199	select HAVE_MOVE_PMD
200	select HAVE_NMI
201	select HAVE_OPROFILE
202	select HAVE_OPTPROBES
203	select HAVE_PCSPKR_PLATFORM
204	select HAVE_PERF_EVENTS
205	select HAVE_PERF_EVENTS_NMI
206	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
207	select HAVE_PCI
208	select HAVE_PERF_REGS
209	select HAVE_PERF_USER_STACK_DUMP
210	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
211	select HAVE_REGS_AND_STACK_ACCESS_API
212	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
213	select HAVE_FUNCTION_ARG_ACCESS_API
214	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
215	select HAVE_STACK_VALIDATION		if X86_64
216	select HAVE_RSEQ
217	select HAVE_SYSCALL_TRACEPOINTS
218	select HAVE_UNSTABLE_SCHED_CLOCK
219	select HAVE_USER_RETURN_NOTIFIER
220	select HAVE_GENERIC_VDSO
221	select HOTPLUG_SMT			if SMP
222	select IRQ_FORCED_THREADING
223	select NEED_SG_DMA_LENGTH
224	select PCI_DOMAINS			if PCI
225	select PCI_LOCKLESS_CONFIG		if PCI
226	select PERF_EVENTS
227	select RTC_LIB
228	select RTC_MC146818_LIB
229	select SPARSE_IRQ
230	select SRCU
231	select SYSCTL_EXCEPTION_TRACE
232	select THREAD_INFO_IN_TASK
233	select USER_STACKTRACE_SUPPORT
234	select VIRT_TO_BUS
235	select HAVE_ARCH_KCSAN			if X86_64
236	select X86_FEATURE_NAMES		if PROC_FS
237	select PROC_PID_ARCH_STATUS		if PROC_FS
238	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
239
240config INSTRUCTION_DECODER
241	def_bool y
242	depends on KPROBES || PERF_EVENTS || UPROBES
243
244config OUTPUT_FORMAT
245	string
246	default "elf32-i386" if X86_32
247	default "elf64-x86-64" if X86_64
248
249config LOCKDEP_SUPPORT
250	def_bool y
251
252config STACKTRACE_SUPPORT
253	def_bool y
254
255config MMU
256	def_bool y
257
258config ARCH_MMAP_RND_BITS_MIN
259	default 28 if 64BIT
260	default 8
261
262config ARCH_MMAP_RND_BITS_MAX
263	default 32 if 64BIT
264	default 16
265
266config ARCH_MMAP_RND_COMPAT_BITS_MIN
267	default 8
268
269config ARCH_MMAP_RND_COMPAT_BITS_MAX
270	default 16
271
272config SBUS
273	bool
274
275config GENERIC_ISA_DMA
276	def_bool y
277	depends on ISA_DMA_API
278
279config GENERIC_BUG
280	def_bool y
281	depends on BUG
282	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
283
284config GENERIC_BUG_RELATIVE_POINTERS
285	bool
286
287config ARCH_MAY_HAVE_PC_FDC
288	def_bool y
289	depends on ISA_DMA_API
290
291config GENERIC_CALIBRATE_DELAY
292	def_bool y
293
294config ARCH_HAS_CPU_RELAX
295	def_bool y
296
297config ARCH_HAS_CACHE_LINE_SIZE
298	def_bool y
299
300config ARCH_HAS_FILTER_PGPROT
301	def_bool y
302
303config HAVE_SETUP_PER_CPU_AREA
304	def_bool y
305
306config NEED_PER_CPU_EMBED_FIRST_CHUNK
307	def_bool y
308
309config NEED_PER_CPU_PAGE_FIRST_CHUNK
310	def_bool y
311
312config ARCH_HIBERNATION_POSSIBLE
313	def_bool y
314
315config ARCH_SUSPEND_POSSIBLE
316	def_bool y
317
318config ARCH_WANT_GENERAL_HUGETLB
319	def_bool y
320
321config ZONE_DMA32
322	def_bool y if X86_64
323
324config AUDIT_ARCH
325	def_bool y if X86_64
326
327config ARCH_SUPPORTS_DEBUG_PAGEALLOC
328	def_bool y
329
330config KASAN_SHADOW_OFFSET
331	hex
332	depends on KASAN
333	default 0xdffffc0000000000
334
335config HAVE_INTEL_TXT
336	def_bool y
337	depends on INTEL_IOMMU && ACPI
338
339config X86_32_SMP
340	def_bool y
341	depends on X86_32 && SMP
342
343config X86_64_SMP
344	def_bool y
345	depends on X86_64 && SMP
346
347config X86_32_LAZY_GS
348	def_bool y
349	depends on X86_32 && !STACKPROTECTOR
350
351config ARCH_SUPPORTS_UPROBES
352	def_bool y
353
354config FIX_EARLYCON_MEM
355	def_bool y
356
357config DYNAMIC_PHYSICAL_MASK
358	bool
359
360config PGTABLE_LEVELS
361	int
362	default 5 if X86_5LEVEL
363	default 4 if X86_64
364	default 3 if X86_PAE
365	default 2
366
367config CC_HAS_SANE_STACKPROTECTOR
368	bool
369	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
370	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
371	help
372	   We have to make sure stack protector is unconditionally disabled if
373	   the compiler produces broken code.
374
375menu "Processor type and features"
376
377config ZONE_DMA
378	bool "DMA memory allocation support" if EXPERT
379	default y
380	help
381	  DMA memory allocation support allows devices with less than 32-bit
382	  addressing to allocate within the first 16MB of address space.
383	  Disable if no such devices will be used.
384
385	  If unsure, say Y.
386
387config SMP
388	bool "Symmetric multi-processing support"
389	help
390	  This enables support for systems with more than one CPU. If you have
391	  a system with only one CPU, say N. If you have a system with more
392	  than one CPU, say Y.
393
394	  If you say N here, the kernel will run on uni- and multiprocessor
395	  machines, but will use only one CPU of a multiprocessor machine. If
396	  you say Y here, the kernel will run on many, but not all,
397	  uniprocessor machines. On a uniprocessor machine, the kernel
398	  will run faster if you say N here.
399
400	  Note that if you say Y here and choose architecture "586" or
401	  "Pentium" under "Processor family", the kernel will not work on 486
402	  architectures. Similarly, multiprocessor kernels for the "PPro"
403	  architecture may not work on all Pentium based boards.
404
405	  People using multiprocessor machines who say Y here should also say
406	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
407	  Management" code will be disabled if you say Y here.
408
409	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
410	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
411	  <http://www.tldp.org/docs.html#howto>.
412
413	  If you don't know what to do here, say N.
414
415config X86_FEATURE_NAMES
416	bool "Processor feature human-readable names" if EMBEDDED
417	default y
418	help
419	  This option compiles in a table of x86 feature bits and corresponding
420	  names.  This is required to support /proc/cpuinfo and a few kernel
421	  messages.  You can disable this to save space, at the expense of
422	  making those few kernel messages show numeric feature bits instead.
423
424	  If in doubt, say Y.
425
426config X86_X2APIC
427	bool "Support x2apic"
428	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
429	help
430	  This enables x2apic support on CPUs that have this feature.
431
432	  This allows 32-bit apic IDs (so it can support very large systems),
433	  and accesses the local apic via MSRs not via mmio.
434
435	  If you don't know what to do here, say N.
436
437config X86_MPPARSE
438	bool "Enable MPS table" if ACPI || SFI
439	default y
440	depends on X86_LOCAL_APIC
441	help
442	  For old smp systems that do not have proper acpi support. Newer systems
443	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
444
445config GOLDFISH
446	def_bool y
447	depends on X86_GOLDFISH
448
449config RETPOLINE
450	bool "Avoid speculative indirect branches in kernel"
451	default y
452	select STACK_VALIDATION if HAVE_STACK_VALIDATION
453	help
454	  Compile kernel with the retpoline compiler options to guard against
455	  kernel-to-user data leaks by avoiding speculative indirect
456	  branches. Requires a compiler with -mindirect-branch=thunk-extern
457	  support for full protection. The kernel may run slower.
458
459config X86_CPU_RESCTRL
460	bool "x86 CPU resource control support"
461	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
462	select KERNFS
463	select PROC_CPU_RESCTRL		if PROC_FS
464	help
465	  Enable x86 CPU resource control support.
466
467	  Provide support for the allocation and monitoring of system resources
468	  usage by the CPU.
469
470	  Intel calls this Intel Resource Director Technology
471	  (Intel(R) RDT). More information about RDT can be found in the
472	  Intel x86 Architecture Software Developer Manual.
473
474	  AMD calls this AMD Platform Quality of Service (AMD QoS).
475	  More information about AMD QoS can be found in the AMD64 Technology
476	  Platform Quality of Service Extensions manual.
477
478	  Say N if unsure.
479
480if X86_32
481config X86_BIGSMP
482	bool "Support for big SMP systems with more than 8 CPUs"
483	depends on SMP
484	help
485	  This option is needed for the systems that have more than 8 CPUs.
486
487config X86_EXTENDED_PLATFORM
488	bool "Support for extended (non-PC) x86 platforms"
489	default y
490	help
491	  If you disable this option then the kernel will only support
492	  standard PC platforms. (which covers the vast majority of
493	  systems out there.)
494
495	  If you enable this option then you'll be able to select support
496	  for the following (non-PC) 32 bit x86 platforms:
497		Goldfish (Android emulator)
498		AMD Elan
499		RDC R-321x SoC
500		SGI 320/540 (Visual Workstation)
501		STA2X11-based (e.g. Northville)
502		Moorestown MID devices
503
504	  If you have one of these systems, or if you want to build a
505	  generic distribution kernel, say Y here - otherwise say N.
506endif
507
508if X86_64
509config X86_EXTENDED_PLATFORM
510	bool "Support for extended (non-PC) x86 platforms"
511	default y
512	help
513	  If you disable this option then the kernel will only support
514	  standard PC platforms. (which covers the vast majority of
515	  systems out there.)
516
517	  If you enable this option then you'll be able to select support
518	  for the following (non-PC) 64 bit x86 platforms:
519		Numascale NumaChip
520		ScaleMP vSMP
521		SGI Ultraviolet
522
523	  If you have one of these systems, or if you want to build a
524	  generic distribution kernel, say Y here - otherwise say N.
525endif
526# This is an alphabetically sorted list of 64 bit extended platforms
527# Please maintain the alphabetic order if and when there are additions
528config X86_NUMACHIP
529	bool "Numascale NumaChip"
530	depends on X86_64
531	depends on X86_EXTENDED_PLATFORM
532	depends on NUMA
533	depends on SMP
534	depends on X86_X2APIC
535	depends on PCI_MMCONFIG
536	help
537	  Adds support for Numascale NumaChip large-SMP systems. Needed to
538	  enable more than ~168 cores.
539	  If you don't have one of these, you should say N here.
540
541config X86_VSMP
542	bool "ScaleMP vSMP"
543	select HYPERVISOR_GUEST
544	select PARAVIRT
545	depends on X86_64 && PCI
546	depends on X86_EXTENDED_PLATFORM
547	depends on SMP
548	help
549	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
550	  supposed to run on these EM64T-based machines.  Only choose this option
551	  if you have one of these machines.
552
553config X86_UV
554	bool "SGI Ultraviolet"
555	depends on X86_64
556	depends on X86_EXTENDED_PLATFORM
557	depends on NUMA
558	depends on EFI
559	depends on X86_X2APIC
560	depends on PCI
561	help
562	  This option is needed in order to support SGI Ultraviolet systems.
563	  If you don't have one of these, you should say N here.
564
565# Following is an alphabetically sorted list of 32 bit extended platforms
566# Please maintain the alphabetic order if and when there are additions
567
568config X86_GOLDFISH
569	bool "Goldfish (Virtual Platform)"
570	depends on X86_EXTENDED_PLATFORM
571	help
572	 Enable support for the Goldfish virtual platform used primarily
573	 for Android development. Unless you are building for the Android
574	 Goldfish emulator say N here.
575
576config X86_INTEL_CE
577	bool "CE4100 TV platform"
578	depends on PCI
579	depends on PCI_GODIRECT
580	depends on X86_IO_APIC
581	depends on X86_32
582	depends on X86_EXTENDED_PLATFORM
583	select X86_REBOOTFIXUPS
584	select OF
585	select OF_EARLY_FLATTREE
586	help
587	  Select for the Intel CE media processor (CE4100) SOC.
588	  This option compiles in support for the CE4100 SOC for settop
589	  boxes and media devices.
590
591config X86_INTEL_MID
592	bool "Intel MID platform support"
593	depends on X86_EXTENDED_PLATFORM
594	depends on X86_PLATFORM_DEVICES
595	depends on PCI
596	depends on X86_64 || (PCI_GOANY && X86_32)
597	depends on X86_IO_APIC
598	select SFI
599	select I2C
600	select DW_APB_TIMER
601	select APB_TIMER
602	select INTEL_SCU_PCI
603	select MFD_INTEL_MSIC
604	help
605	  Select to build a kernel capable of supporting Intel MID (Mobile
606	  Internet Device) platform systems which do not have the PCI legacy
607	  interfaces. If you are building for a PC class system say N here.
608
609	  Intel MID platforms are based on an Intel processor and chipset which
610	  consume less power than most of the x86 derivatives.
611
612config X86_INTEL_QUARK
613	bool "Intel Quark platform support"
614	depends on X86_32
615	depends on X86_EXTENDED_PLATFORM
616	depends on X86_PLATFORM_DEVICES
617	depends on X86_TSC
618	depends on PCI
619	depends on PCI_GOANY
620	depends on X86_IO_APIC
621	select IOSF_MBI
622	select INTEL_IMR
623	select COMMON_CLK
624	help
625	  Select to include support for Quark X1000 SoC.
626	  Say Y here if you have a Quark based system such as the Arduino
627	  compatible Intel Galileo.
628
629config X86_INTEL_LPSS
630	bool "Intel Low Power Subsystem Support"
631	depends on X86 && ACPI && PCI
632	select COMMON_CLK
633	select PINCTRL
634	select IOSF_MBI
635	help
636	  Select to build support for Intel Low Power Subsystem such as
637	  found on Intel Lynxpoint PCH. Selecting this option enables
638	  things like clock tree (common clock framework) and pincontrol
639	  which are needed by the LPSS peripheral drivers.
640
641config X86_AMD_PLATFORM_DEVICE
642	bool "AMD ACPI2Platform devices support"
643	depends on ACPI
644	select COMMON_CLK
645	select PINCTRL
646	help
647	  Select to interpret AMD specific ACPI device to platform device
648	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
649	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
650	  implemented under PINCTRL subsystem.
651
652config IOSF_MBI
653	tristate "Intel SoC IOSF Sideband support for SoC platforms"
654	depends on PCI
655	help
656	  This option enables sideband register access support for Intel SoC
657	  platforms. On these platforms the IOSF sideband is used in lieu of
658	  MSR's for some register accesses, mostly but not limited to thermal
659	  and power. Drivers may query the availability of this device to
660	  determine if they need the sideband in order to work on these
661	  platforms. The sideband is available on the following SoC products.
662	  This list is not meant to be exclusive.
663	   - BayTrail
664	   - Braswell
665	   - Quark
666
667	  You should say Y if you are running a kernel on one of these SoC's.
668
669config IOSF_MBI_DEBUG
670	bool "Enable IOSF sideband access through debugfs"
671	depends on IOSF_MBI && DEBUG_FS
672	help
673	  Select this option to expose the IOSF sideband access registers (MCR,
674	  MDR, MCRX) through debugfs to write and read register information from
675	  different units on the SoC. This is most useful for obtaining device
676	  state information for debug and analysis. As this is a general access
677	  mechanism, users of this option would have specific knowledge of the
678	  device they want to access.
679
680	  If you don't require the option or are in doubt, say N.
681
682config X86_RDC321X
683	bool "RDC R-321x SoC"
684	depends on X86_32
685	depends on X86_EXTENDED_PLATFORM
686	select M486
687	select X86_REBOOTFIXUPS
688	help
689	  This option is needed for RDC R-321x system-on-chip, also known
690	  as R-8610-(G).
691	  If you don't have one of these chips, you should say N here.
692
693config X86_32_NON_STANDARD
694	bool "Support non-standard 32-bit SMP architectures"
695	depends on X86_32 && SMP
696	depends on X86_EXTENDED_PLATFORM
697	help
698	  This option compiles in the bigsmp and STA2X11 default
699	  subarchitectures.  It is intended for a generic binary
700	  kernel. If you select them all, kernel will probe it one by
701	  one and will fallback to default.
702
703# Alphabetically sorted list of Non standard 32 bit platforms
704
705config X86_SUPPORTS_MEMORY_FAILURE
706	def_bool y
707	# MCE code calls memory_failure():
708	depends on X86_MCE
709	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
710	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
711	depends on X86_64 || !SPARSEMEM
712	select ARCH_SUPPORTS_MEMORY_FAILURE
713
714config STA2X11
715	bool "STA2X11 Companion Chip Support"
716	depends on X86_32_NON_STANDARD && PCI
717	select SWIOTLB
718	select MFD_STA2X11
719	select GPIOLIB
720	help
721	  This adds support for boards based on the STA2X11 IO-Hub,
722	  a.k.a. "ConneXt". The chip is used in place of the standard
723	  PC chipset, so all "standard" peripherals are missing. If this
724	  option is selected the kernel will still be able to boot on
725	  standard PC machines.
726
727config X86_32_IRIS
728	tristate "Eurobraille/Iris poweroff module"
729	depends on X86_32
730	help
731	  The Iris machines from EuroBraille do not have APM or ACPI support
732	  to shut themselves down properly.  A special I/O sequence is
733	  needed to do so, which is what this module does at
734	  kernel shutdown.
735
736	  This is only for Iris machines from EuroBraille.
737
738	  If unused, say N.
739
740config SCHED_OMIT_FRAME_POINTER
741	def_bool y
742	prompt "Single-depth WCHAN output"
743	depends on X86
744	help
745	  Calculate simpler /proc/<PID>/wchan values. If this option
746	  is disabled then wchan values will recurse back to the
747	  caller function. This provides more accurate wchan values,
748	  at the expense of slightly more scheduling overhead.
749
750	  If in doubt, say "Y".
751
752menuconfig HYPERVISOR_GUEST
753	bool "Linux guest support"
754	help
755	  Say Y here to enable options for running Linux under various hyper-
756	  visors. This option enables basic hypervisor detection and platform
757	  setup.
758
759	  If you say N, all options in this submenu will be skipped and
760	  disabled, and Linux guest support won't be built in.
761
762if HYPERVISOR_GUEST
763
764config PARAVIRT
765	bool "Enable paravirtualization code"
766	help
767	  This changes the kernel so it can modify itself when it is run
768	  under a hypervisor, potentially improving performance significantly
769	  over full virtualization.  However, when run without a hypervisor
770	  the kernel is theoretically slower and slightly larger.
771
772config PARAVIRT_XXL
773	bool
774
775config PARAVIRT_DEBUG
776	bool "paravirt-ops debugging"
777	depends on PARAVIRT && DEBUG_KERNEL
778	help
779	  Enable to debug paravirt_ops internals.  Specifically, BUG if
780	  a paravirt_op is missing when it is called.
781
782config PARAVIRT_SPINLOCKS
783	bool "Paravirtualization layer for spinlocks"
784	depends on PARAVIRT && SMP
785	help
786	  Paravirtualized spinlocks allow a pvops backend to replace the
787	  spinlock implementation with something virtualization-friendly
788	  (for example, block the virtual CPU rather than spinning).
789
790	  It has a minimal impact on native kernels and gives a nice performance
791	  benefit on paravirtualized KVM / Xen kernels.
792
793	  If you are unsure how to answer this question, answer Y.
794
795config X86_HV_CALLBACK_VECTOR
796	def_bool n
797
798source "arch/x86/xen/Kconfig"
799
800config KVM_GUEST
801	bool "KVM Guest support (including kvmclock)"
802	depends on PARAVIRT
803	select PARAVIRT_CLOCK
804	select ARCH_CPUIDLE_HALTPOLL
805	default y
806	help
807	  This option enables various optimizations for running under the KVM
808	  hypervisor. It includes a paravirtualized clock, so that instead
809	  of relying on a PIT (or probably other) emulation by the
810	  underlying device model, the host provides the guest with
811	  timing infrastructure such as time of day, and system time
812
813config ARCH_CPUIDLE_HALTPOLL
814	def_bool n
815	prompt "Disable host haltpoll when loading haltpoll driver"
816	help
817	  If virtualized under KVM, disable host haltpoll.
818
819config PVH
820	bool "Support for running PVH guests"
821	help
822	  This option enables the PVH entry point for guest virtual machines
823	  as specified in the x86/HVM direct boot ABI.
824
825config PARAVIRT_TIME_ACCOUNTING
826	bool "Paravirtual steal time accounting"
827	depends on PARAVIRT
828	help
829	  Select this option to enable fine granularity task steal time
830	  accounting. Time spent executing other tasks in parallel with
831	  the current vCPU is discounted from the vCPU power. To account for
832	  that, there can be a small performance impact.
833
834	  If in doubt, say N here.
835
836config PARAVIRT_CLOCK
837	bool
838
839config JAILHOUSE_GUEST
840	bool "Jailhouse non-root cell support"
841	depends on X86_64 && PCI
842	select X86_PM_TIMER
843	help
844	  This option allows to run Linux as guest in a Jailhouse non-root
845	  cell. You can leave this option disabled if you only want to start
846	  Jailhouse and run Linux afterwards in the root cell.
847
848config ACRN_GUEST
849	bool "ACRN Guest support"
850	depends on X86_64
851	select X86_HV_CALLBACK_VECTOR
852	help
853	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
854	  a flexible, lightweight reference open-source hypervisor, built with
855	  real-time and safety-criticality in mind. It is built for embedded
856	  IOT with small footprint and real-time features. More details can be
857	  found in https://projectacrn.org/.
858
859endif #HYPERVISOR_GUEST
860
861source "arch/x86/Kconfig.cpu"
862
863config HPET_TIMER
864	def_bool X86_64
865	prompt "HPET Timer Support" if X86_32
866	help
867	  Use the IA-PC HPET (High Precision Event Timer) to manage
868	  time in preference to the PIT and RTC, if a HPET is
869	  present.
870	  HPET is the next generation timer replacing legacy 8254s.
871	  The HPET provides a stable time base on SMP
872	  systems, unlike the TSC, but it is more expensive to access,
873	  as it is off-chip.  The interface used is documented
874	  in the HPET spec, revision 1.
875
876	  You can safely choose Y here.  However, HPET will only be
877	  activated if the platform and the BIOS support this feature.
878	  Otherwise the 8254 will be used for timing services.
879
880	  Choose N to continue using the legacy 8254 timer.
881
882config HPET_EMULATE_RTC
883	def_bool y
884	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
885
886config APB_TIMER
887	def_bool y if X86_INTEL_MID
888	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
889	select DW_APB_TIMER
890	depends on X86_INTEL_MID && SFI
891	help
892	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
893	 The APBT provides a stable time base on SMP
894	 systems, unlike the TSC, but it is more expensive to access,
895	 as it is off-chip. APB timers are always running regardless of CPU
896	 C states, they are used as per CPU clockevent device when possible.
897
898# Mark as expert because too many people got it wrong.
899# The code disables itself when not needed.
900config DMI
901	default y
902	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
903	bool "Enable DMI scanning" if EXPERT
904	help
905	  Enabled scanning of DMI to identify machine quirks. Say Y
906	  here unless you have verified that your setup is not
907	  affected by entries in the DMI blacklist. Required by PNP
908	  BIOS code.
909
910config GART_IOMMU
911	bool "Old AMD GART IOMMU support"
912	select IOMMU_HELPER
913	select SWIOTLB
914	depends on X86_64 && PCI && AMD_NB
915	help
916	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
917	  GART based hardware IOMMUs.
918
919	  The GART supports full DMA access for devices with 32-bit access
920	  limitations, on systems with more than 3 GB. This is usually needed
921	  for USB, sound, many IDE/SATA chipsets and some other devices.
922
923	  Newer systems typically have a modern AMD IOMMU, supported via
924	  the CONFIG_AMD_IOMMU=y config option.
925
926	  In normal configurations this driver is only active when needed:
927	  there's more than 3 GB of memory and the system contains a
928	  32-bit limited device.
929
930	  If unsure, say Y.
931
932config MAXSMP
933	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
934	depends on X86_64 && SMP && DEBUG_KERNEL
935	select CPUMASK_OFFSTACK
936	help
937	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
938	  If unsure, say N.
939
940#
941# The maximum number of CPUs supported:
942#
943# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
944# and which can be configured interactively in the
945# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
946#
947# The ranges are different on 32-bit and 64-bit kernels, depending on
948# hardware capabilities and scalability features of the kernel.
949#
950# ( If MAXSMP is enabled we just use the highest possible value and disable
951#   interactive configuration. )
952#
953
954config NR_CPUS_RANGE_BEGIN
955	int
956	default NR_CPUS_RANGE_END if MAXSMP
957	default    1 if !SMP
958	default    2
959
960config NR_CPUS_RANGE_END
961	int
962	depends on X86_32
963	default   64 if  SMP &&  X86_BIGSMP
964	default    8 if  SMP && !X86_BIGSMP
965	default    1 if !SMP
966
967config NR_CPUS_RANGE_END
968	int
969	depends on X86_64
970	default 8192 if  SMP && CPUMASK_OFFSTACK
971	default  512 if  SMP && !CPUMASK_OFFSTACK
972	default    1 if !SMP
973
974config NR_CPUS_DEFAULT
975	int
976	depends on X86_32
977	default   32 if  X86_BIGSMP
978	default    8 if  SMP
979	default    1 if !SMP
980
981config NR_CPUS_DEFAULT
982	int
983	depends on X86_64
984	default 8192 if  MAXSMP
985	default   64 if  SMP
986	default    1 if !SMP
987
988config NR_CPUS
989	int "Maximum number of CPUs" if SMP && !MAXSMP
990	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
991	default NR_CPUS_DEFAULT
992	help
993	  This allows you to specify the maximum number of CPUs which this
994	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
995	  supported value is 8192, otherwise the maximum value is 512.  The
996	  minimum value which makes sense is 2.
997
998	  This is purely to save memory: each supported CPU adds about 8KB
999	  to the kernel image.
1000
1001config SCHED_SMT
1002	def_bool y if SMP
1003
1004config SCHED_MC
1005	def_bool y
1006	prompt "Multi-core scheduler support"
1007	depends on SMP
1008	help
1009	  Multi-core scheduler support improves the CPU scheduler's decision
1010	  making when dealing with multi-core CPU chips at a cost of slightly
1011	  increased overhead in some places. If unsure say N here.
1012
1013config SCHED_MC_PRIO
1014	bool "CPU core priorities scheduler support"
1015	depends on SCHED_MC && CPU_SUP_INTEL
1016	select X86_INTEL_PSTATE
1017	select CPU_FREQ
1018	default y
1019	help
1020	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1021	  core ordering determined at manufacturing time, which allows
1022	  certain cores to reach higher turbo frequencies (when running
1023	  single threaded workloads) than others.
1024
1025	  Enabling this kernel feature teaches the scheduler about
1026	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1027	  scheduler's CPU selection logic accordingly, so that higher
1028	  overall system performance can be achieved.
1029
1030	  This feature will have no effect on CPUs without this feature.
1031
1032	  If unsure say Y here.
1033
1034config UP_LATE_INIT
1035	def_bool y
1036	depends on !SMP && X86_LOCAL_APIC
1037
1038config X86_UP_APIC
1039	bool "Local APIC support on uniprocessors" if !PCI_MSI
1040	default PCI_MSI
1041	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1042	help
1043	  A local APIC (Advanced Programmable Interrupt Controller) is an
1044	  integrated interrupt controller in the CPU. If you have a single-CPU
1045	  system which has a processor with a local APIC, you can say Y here to
1046	  enable and use it. If you say Y here even though your machine doesn't
1047	  have a local APIC, then the kernel will still run with no slowdown at
1048	  all. The local APIC supports CPU-generated self-interrupts (timer,
1049	  performance counters), and the NMI watchdog which detects hard
1050	  lockups.
1051
1052config X86_UP_IOAPIC
1053	bool "IO-APIC support on uniprocessors"
1054	depends on X86_UP_APIC
1055	help
1056	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1057	  SMP-capable replacement for PC-style interrupt controllers. Most
1058	  SMP systems and many recent uniprocessor systems have one.
1059
1060	  If you have a single-CPU system with an IO-APIC, you can say Y here
1061	  to use it. If you say Y here even though your machine doesn't have
1062	  an IO-APIC, then the kernel will still run with no slowdown at all.
1063
1064config X86_LOCAL_APIC
1065	def_bool y
1066	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1067	select IRQ_DOMAIN_HIERARCHY
1068	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1069
1070config X86_IO_APIC
1071	def_bool y
1072	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1073
1074config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1075	bool "Reroute for broken boot IRQs"
1076	depends on X86_IO_APIC
1077	help
1078	  This option enables a workaround that fixes a source of
1079	  spurious interrupts. This is recommended when threaded
1080	  interrupt handling is used on systems where the generation of
1081	  superfluous "boot interrupts" cannot be disabled.
1082
1083	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1084	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1085	  kernel does during interrupt handling). On chipsets where this
1086	  boot IRQ generation cannot be disabled, this workaround keeps
1087	  the original IRQ line masked so that only the equivalent "boot
1088	  IRQ" is delivered to the CPUs. The workaround also tells the
1089	  kernel to set up the IRQ handler on the boot IRQ line. In this
1090	  way only one interrupt is delivered to the kernel. Otherwise
1091	  the spurious second interrupt may cause the kernel to bring
1092	  down (vital) interrupt lines.
1093
1094	  Only affects "broken" chipsets. Interrupt sharing may be
1095	  increased on these systems.
1096
1097config X86_MCE
1098	bool "Machine Check / overheating reporting"
1099	select GENERIC_ALLOCATOR
1100	default y
1101	help
1102	  Machine Check support allows the processor to notify the
1103	  kernel if it detects a problem (e.g. overheating, data corruption).
1104	  The action the kernel takes depends on the severity of the problem,
1105	  ranging from warning messages to halting the machine.
1106
1107config X86_MCELOG_LEGACY
1108	bool "Support for deprecated /dev/mcelog character device"
1109	depends on X86_MCE
1110	help
1111	  Enable support for /dev/mcelog which is needed by the old mcelog
1112	  userspace logging daemon. Consider switching to the new generation
1113	  rasdaemon solution.
1114
1115config X86_MCE_INTEL
1116	def_bool y
1117	prompt "Intel MCE features"
1118	depends on X86_MCE && X86_LOCAL_APIC
1119	help
1120	   Additional support for intel specific MCE features such as
1121	   the thermal monitor.
1122
1123config X86_MCE_AMD
1124	def_bool y
1125	prompt "AMD MCE features"
1126	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1127	help
1128	   Additional support for AMD specific MCE features such as
1129	   the DRAM Error Threshold.
1130
1131config X86_ANCIENT_MCE
1132	bool "Support for old Pentium 5 / WinChip machine checks"
1133	depends on X86_32 && X86_MCE
1134	help
1135	  Include support for machine check handling on old Pentium 5 or WinChip
1136	  systems. These typically need to be enabled explicitly on the command
1137	  line.
1138
1139config X86_MCE_THRESHOLD
1140	depends on X86_MCE_AMD || X86_MCE_INTEL
1141	def_bool y
1142
1143config X86_MCE_INJECT
1144	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1145	tristate "Machine check injector support"
1146	help
1147	  Provide support for injecting machine checks for testing purposes.
1148	  If you don't know what a machine check is and you don't do kernel
1149	  QA it is safe to say n.
1150
1151config X86_THERMAL_VECTOR
1152	def_bool y
1153	depends on X86_MCE_INTEL
1154
1155source "arch/x86/events/Kconfig"
1156
1157config X86_LEGACY_VM86
1158	bool "Legacy VM86 support"
1159	depends on X86_32
1160	help
1161	  This option allows user programs to put the CPU into V8086
1162	  mode, which is an 80286-era approximation of 16-bit real mode.
1163
1164	  Some very old versions of X and/or vbetool require this option
1165	  for user mode setting.  Similarly, DOSEMU will use it if
1166	  available to accelerate real mode DOS programs.  However, any
1167	  recent version of DOSEMU, X, or vbetool should be fully
1168	  functional even without kernel VM86 support, as they will all
1169	  fall back to software emulation. Nevertheless, if you are using
1170	  a 16-bit DOS program where 16-bit performance matters, vm86
1171	  mode might be faster than emulation and you might want to
1172	  enable this option.
1173
1174	  Note that any app that works on a 64-bit kernel is unlikely to
1175	  need this option, as 64-bit kernels don't, and can't, support
1176	  V8086 mode. This option is also unrelated to 16-bit protected
1177	  mode and is not needed to run most 16-bit programs under Wine.
1178
1179	  Enabling this option increases the complexity of the kernel
1180	  and slows down exception handling a tiny bit.
1181
1182	  If unsure, say N here.
1183
1184config VM86
1185	bool
1186	default X86_LEGACY_VM86
1187
1188config X86_16BIT
1189	bool "Enable support for 16-bit segments" if EXPERT
1190	default y
1191	depends on MODIFY_LDT_SYSCALL
1192	help
1193	  This option is required by programs like Wine to run 16-bit
1194	  protected mode legacy code on x86 processors.  Disabling
1195	  this option saves about 300 bytes on i386, or around 6K text
1196	  plus 16K runtime memory on x86-64,
1197
1198config X86_ESPFIX32
1199	def_bool y
1200	depends on X86_16BIT && X86_32
1201
1202config X86_ESPFIX64
1203	def_bool y
1204	depends on X86_16BIT && X86_64
1205
1206config X86_VSYSCALL_EMULATION
1207	bool "Enable vsyscall emulation" if EXPERT
1208	default y
1209	depends on X86_64
1210	help
1211	 This enables emulation of the legacy vsyscall page.  Disabling
1212	 it is roughly equivalent to booting with vsyscall=none, except
1213	 that it will also disable the helpful warning if a program
1214	 tries to use a vsyscall.  With this option set to N, offending
1215	 programs will just segfault, citing addresses of the form
1216	 0xffffffffff600?00.
1217
1218	 This option is required by many programs built before 2013, and
1219	 care should be used even with newer programs if set to N.
1220
1221	 Disabling this option saves about 7K of kernel size and
1222	 possibly 4K of additional runtime pagetable memory.
1223
1224config X86_IOPL_IOPERM
1225	bool "IOPERM and IOPL Emulation"
1226	default y
1227	help
1228	  This enables the ioperm() and iopl() syscalls which are necessary
1229	  for legacy applications.
1230
1231	  Legacy IOPL support is an overbroad mechanism which allows user
1232	  space aside of accessing all 65536 I/O ports also to disable
1233	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1234	  capabilities and permission from potentially active security
1235	  modules.
1236
1237	  The emulation restricts the functionality of the syscall to
1238	  only allowing the full range I/O port access, but prevents the
1239	  ability to disable interrupts from user space which would be
1240	  granted if the hardware IOPL mechanism would be used.
1241
1242config TOSHIBA
1243	tristate "Toshiba Laptop support"
1244	depends on X86_32
1245	help
1246	  This adds a driver to safely access the System Management Mode of
1247	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248	  not work on models with a Phoenix BIOS. The System Management Mode
1249	  is used to set the BIOS and power saving options on Toshiba portables.
1250
1251	  For information on utilities to make use of this driver see the
1252	  Toshiba Linux utilities web site at:
1253	  <http://www.buzzard.org.uk/toshiba/>.
1254
1255	  Say Y if you intend to run this kernel on a Toshiba portable.
1256	  Say N otherwise.
1257
1258config I8K
1259	tristate "Dell i8k legacy laptop support"
1260	select HWMON
1261	select SENSORS_DELL_SMM
1262	help
1263	  This option enables legacy /proc/i8k userspace interface in hwmon
1264	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265	  temperature and allows controlling fan speeds of Dell laptops via
1266	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267	  it reports also power and hotkey status. For fan speed control is
1268	  needed userspace package i8kutils.
1269
1270	  Say Y if you intend to run this kernel on old Dell laptops or want to
1271	  use userspace package i8kutils.
1272	  Say N otherwise.
1273
1274config X86_REBOOTFIXUPS
1275	bool "Enable X86 board specific fixups for reboot"
1276	depends on X86_32
1277	help
1278	  This enables chipset and/or board specific fixups to be done
1279	  in order to get reboot to work correctly. This is only needed on
1280	  some combinations of hardware and BIOS. The symptom, for which
1281	  this config is intended, is when reboot ends with a stalled/hung
1282	  system.
1283
1284	  Currently, the only fixup is for the Geode machines using
1285	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1286
1287	  Say Y if you want to enable the fixup. Currently, it's safe to
1288	  enable this option even if you don't need it.
1289	  Say N otherwise.
1290
1291config MICROCODE
1292	bool "CPU microcode loading support"
1293	default y
1294	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1295	select FW_LOADER
1296	help
1297	  If you say Y here, you will be able to update the microcode on
1298	  Intel and AMD processors. The Intel support is for the IA32 family,
1299	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1300	  AMD support is for families 0x10 and later. You will obviously need
1301	  the actual microcode binary data itself which is not shipped with
1302	  the Linux kernel.
1303
1304	  The preferred method to load microcode from a detached initrd is described
1305	  in Documentation/x86/microcode.rst. For that you need to enable
1306	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1307	  initrd for microcode blobs.
1308
1309	  In addition, you can build the microcode into the kernel. For that you
1310	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1311	  config option.
1312
1313config MICROCODE_INTEL
1314	bool "Intel microcode loading support"
1315	depends on MICROCODE
1316	default MICROCODE
1317	select FW_LOADER
1318	help
1319	  This options enables microcode patch loading support for Intel
1320	  processors.
1321
1322	  For the current Intel microcode data package go to
1323	  <https://downloadcenter.intel.com> and search for
1324	  'Linux Processor Microcode Data File'.
1325
1326config MICROCODE_AMD
1327	bool "AMD microcode loading support"
1328	depends on MICROCODE
1329	select FW_LOADER
1330	help
1331	  If you select this option, microcode patch loading support for AMD
1332	  processors will be enabled.
1333
1334config MICROCODE_OLD_INTERFACE
1335	bool "Ancient loading interface (DEPRECATED)"
1336	default n
1337	depends on MICROCODE
1338	help
1339	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1340	  which was used by userspace tools like iucode_tool and microcode.ctl.
1341	  It is inadequate because it runs too late to be able to properly
1342	  load microcode on a machine and it needs special tools. Instead, you
1343	  should've switched to the early loading method with the initrd or
1344	  builtin microcode by now: Documentation/x86/microcode.rst
1345
1346config X86_MSR
1347	tristate "/dev/cpu/*/msr - Model-specific register support"
1348	help
1349	  This device gives privileged processes access to the x86
1350	  Model-Specific Registers (MSRs).  It is a character device with
1351	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1352	  MSR accesses are directed to a specific CPU on multi-processor
1353	  systems.
1354
1355config X86_CPUID
1356	tristate "/dev/cpu/*/cpuid - CPU information support"
1357	help
1358	  This device gives processes access to the x86 CPUID instruction to
1359	  be executed on a specific processor.  It is a character device
1360	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1361	  /dev/cpu/31/cpuid.
1362
1363choice
1364	prompt "High Memory Support"
1365	default HIGHMEM4G
1366	depends on X86_32
1367
1368config NOHIGHMEM
1369	bool "off"
1370	help
1371	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1372	  However, the address space of 32-bit x86 processors is only 4
1373	  Gigabytes large. That means that, if you have a large amount of
1374	  physical memory, not all of it can be "permanently mapped" by the
1375	  kernel. The physical memory that's not permanently mapped is called
1376	  "high memory".
1377
1378	  If you are compiling a kernel which will never run on a machine with
1379	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1380	  choice and suitable for most users). This will result in a "3GB/1GB"
1381	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1382	  space and the remaining part of the 4GB virtual memory space is used
1383	  by the kernel to permanently map as much physical memory as
1384	  possible.
1385
1386	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1387	  answer "4GB" here.
1388
1389	  If more than 4 Gigabytes is used then answer "64GB" here. This
1390	  selection turns Intel PAE (Physical Address Extension) mode on.
1391	  PAE implements 3-level paging on IA32 processors. PAE is fully
1392	  supported by Linux, PAE mode is implemented on all recent Intel
1393	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1394	  then the kernel will not boot on CPUs that don't support PAE!
1395
1396	  The actual amount of total physical memory will either be
1397	  auto detected or can be forced by using a kernel command line option
1398	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1399	  your boot loader (lilo or loadlin) about how to pass options to the
1400	  kernel at boot time.)
1401
1402	  If unsure, say "off".
1403
1404config HIGHMEM4G
1405	bool "4GB"
1406	help
1407	  Select this if you have a 32-bit processor and between 1 and 4
1408	  gigabytes of physical RAM.
1409
1410config HIGHMEM64G
1411	bool "64GB"
1412	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1413	select X86_PAE
1414	help
1415	  Select this if you have a 32-bit processor and more than 4
1416	  gigabytes of physical RAM.
1417
1418endchoice
1419
1420choice
1421	prompt "Memory split" if EXPERT
1422	default VMSPLIT_3G
1423	depends on X86_32
1424	help
1425	  Select the desired split between kernel and user memory.
1426
1427	  If the address range available to the kernel is less than the
1428	  physical memory installed, the remaining memory will be available
1429	  as "high memory". Accessing high memory is a little more costly
1430	  than low memory, as it needs to be mapped into the kernel first.
1431	  Note that increasing the kernel address space limits the range
1432	  available to user programs, making the address space there
1433	  tighter.  Selecting anything other than the default 3G/1G split
1434	  will also likely make your kernel incompatible with binary-only
1435	  kernel modules.
1436
1437	  If you are not absolutely sure what you are doing, leave this
1438	  option alone!
1439
1440	config VMSPLIT_3G
1441		bool "3G/1G user/kernel split"
1442	config VMSPLIT_3G_OPT
1443		depends on !X86_PAE
1444		bool "3G/1G user/kernel split (for full 1G low memory)"
1445	config VMSPLIT_2G
1446		bool "2G/2G user/kernel split"
1447	config VMSPLIT_2G_OPT
1448		depends on !X86_PAE
1449		bool "2G/2G user/kernel split (for full 2G low memory)"
1450	config VMSPLIT_1G
1451		bool "1G/3G user/kernel split"
1452endchoice
1453
1454config PAGE_OFFSET
1455	hex
1456	default 0xB0000000 if VMSPLIT_3G_OPT
1457	default 0x80000000 if VMSPLIT_2G
1458	default 0x78000000 if VMSPLIT_2G_OPT
1459	default 0x40000000 if VMSPLIT_1G
1460	default 0xC0000000
1461	depends on X86_32
1462
1463config HIGHMEM
1464	def_bool y
1465	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1466
1467config X86_PAE
1468	bool "PAE (Physical Address Extension) Support"
1469	depends on X86_32 && !HIGHMEM4G
1470	select PHYS_ADDR_T_64BIT
1471	select SWIOTLB
1472	help
1473	  PAE is required for NX support, and furthermore enables
1474	  larger swapspace support for non-overcommit purposes. It
1475	  has the cost of more pagetable lookup overhead, and also
1476	  consumes more pagetable space per process.
1477
1478config X86_5LEVEL
1479	bool "Enable 5-level page tables support"
1480	default y
1481	select DYNAMIC_MEMORY_LAYOUT
1482	select SPARSEMEM_VMEMMAP
1483	depends on X86_64
1484	help
1485	  5-level paging enables access to larger address space:
1486	  upto 128 PiB of virtual address space and 4 PiB of
1487	  physical address space.
1488
1489	  It will be supported by future Intel CPUs.
1490
1491	  A kernel with the option enabled can be booted on machines that
1492	  support 4- or 5-level paging.
1493
1494	  See Documentation/x86/x86_64/5level-paging.rst for more
1495	  information.
1496
1497	  Say N if unsure.
1498
1499config X86_DIRECT_GBPAGES
1500	def_bool y
1501	depends on X86_64
1502	help
1503	  Certain kernel features effectively disable kernel
1504	  linear 1 GB mappings (even if the CPU otherwise
1505	  supports them), so don't confuse the user by printing
1506	  that we have them enabled.
1507
1508config X86_CPA_STATISTICS
1509	bool "Enable statistic for Change Page Attribute"
1510	depends on DEBUG_FS
1511	help
1512	  Expose statistics about the Change Page Attribute mechanism, which
1513	  helps to determine the effectiveness of preserving large and huge
1514	  page mappings when mapping protections are changed.
1515
1516config AMD_MEM_ENCRYPT
1517	bool "AMD Secure Memory Encryption (SME) support"
1518	depends on X86_64 && CPU_SUP_AMD
1519	select DMA_COHERENT_POOL
1520	select DYNAMIC_PHYSICAL_MASK
1521	select ARCH_USE_MEMREMAP_PROT
1522	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1523	help
1524	  Say yes to enable support for the encryption of system memory.
1525	  This requires an AMD processor that supports Secure Memory
1526	  Encryption (SME).
1527
1528config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1529	bool "Activate AMD Secure Memory Encryption (SME) by default"
1530	default y
1531	depends on AMD_MEM_ENCRYPT
1532	help
1533	  Say yes to have system memory encrypted by default if running on
1534	  an AMD processor that supports Secure Memory Encryption (SME).
1535
1536	  If set to Y, then the encryption of system memory can be
1537	  deactivated with the mem_encrypt=off command line option.
1538
1539	  If set to N, then the encryption of system memory can be
1540	  activated with the mem_encrypt=on command line option.
1541
1542# Common NUMA Features
1543config NUMA
1544	bool "NUMA Memory Allocation and Scheduler Support"
1545	depends on SMP
1546	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1547	default y if X86_BIGSMP
1548	help
1549	  Enable NUMA (Non-Uniform Memory Access) support.
1550
1551	  The kernel will try to allocate memory used by a CPU on the
1552	  local memory controller of the CPU and add some more
1553	  NUMA awareness to the kernel.
1554
1555	  For 64-bit this is recommended if the system is Intel Core i7
1556	  (or later), AMD Opteron, or EM64T NUMA.
1557
1558	  For 32-bit this is only needed if you boot a 32-bit
1559	  kernel on a 64-bit NUMA platform.
1560
1561	  Otherwise, you should say N.
1562
1563config AMD_NUMA
1564	def_bool y
1565	prompt "Old style AMD Opteron NUMA detection"
1566	depends on X86_64 && NUMA && PCI
1567	help
1568	  Enable AMD NUMA node topology detection.  You should say Y here if
1569	  you have a multi processor AMD system. This uses an old method to
1570	  read the NUMA configuration directly from the builtin Northbridge
1571	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1572	  which also takes priority if both are compiled in.
1573
1574config X86_64_ACPI_NUMA
1575	def_bool y
1576	prompt "ACPI NUMA detection"
1577	depends on X86_64 && NUMA && ACPI && PCI
1578	select ACPI_NUMA
1579	help
1580	  Enable ACPI SRAT based node topology detection.
1581
1582config NUMA_EMU
1583	bool "NUMA emulation"
1584	depends on NUMA
1585	help
1586	  Enable NUMA emulation. A flat machine will be split
1587	  into virtual nodes when booted with "numa=fake=N", where N is the
1588	  number of nodes. This is only useful for debugging.
1589
1590config NODES_SHIFT
1591	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1592	range 1 10
1593	default "10" if MAXSMP
1594	default "6" if X86_64
1595	default "3"
1596	depends on NEED_MULTIPLE_NODES
1597	help
1598	  Specify the maximum number of NUMA Nodes available on the target
1599	  system.  Increases memory reserved to accommodate various tables.
1600
1601config ARCH_FLATMEM_ENABLE
1602	def_bool y
1603	depends on X86_32 && !NUMA
1604
1605config ARCH_SPARSEMEM_ENABLE
1606	def_bool y
1607	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1608	select SPARSEMEM_STATIC if X86_32
1609	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1610
1611config ARCH_SPARSEMEM_DEFAULT
1612	def_bool X86_64 || (NUMA && X86_32)
1613
1614config ARCH_SELECT_MEMORY_MODEL
1615	def_bool y
1616	depends on ARCH_SPARSEMEM_ENABLE
1617
1618config ARCH_MEMORY_PROBE
1619	bool "Enable sysfs memory/probe interface"
1620	depends on X86_64 && MEMORY_HOTPLUG
1621	help
1622	  This option enables a sysfs memory/probe interface for testing.
1623	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1624	  If you are unsure how to answer this question, answer N.
1625
1626config ARCH_PROC_KCORE_TEXT
1627	def_bool y
1628	depends on X86_64 && PROC_KCORE
1629
1630config ILLEGAL_POINTER_VALUE
1631	hex
1632	default 0 if X86_32
1633	default 0xdead000000000000 if X86_64
1634
1635config X86_PMEM_LEGACY_DEVICE
1636	bool
1637
1638config X86_PMEM_LEGACY
1639	tristate "Support non-standard NVDIMMs and ADR protected memory"
1640	depends on PHYS_ADDR_T_64BIT
1641	depends on BLK_DEV
1642	select X86_PMEM_LEGACY_DEVICE
1643	select NUMA_KEEP_MEMINFO if NUMA
1644	select LIBNVDIMM
1645	help
1646	  Treat memory marked using the non-standard e820 type of 12 as used
1647	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1648	  The kernel will offer these regions to the 'pmem' driver so
1649	  they can be used for persistent storage.
1650
1651	  Say Y if unsure.
1652
1653config HIGHPTE
1654	bool "Allocate 3rd-level pagetables from highmem"
1655	depends on HIGHMEM
1656	help
1657	  The VM uses one page table entry for each page of physical memory.
1658	  For systems with a lot of RAM, this can be wasteful of precious
1659	  low memory.  Setting this option will put user-space page table
1660	  entries in high memory.
1661
1662config X86_CHECK_BIOS_CORRUPTION
1663	bool "Check for low memory corruption"
1664	help
1665	  Periodically check for memory corruption in low memory, which
1666	  is suspected to be caused by BIOS.  Even when enabled in the
1667	  configuration, it is disabled at runtime.  Enable it by
1668	  setting "memory_corruption_check=1" on the kernel command
1669	  line.  By default it scans the low 64k of memory every 60
1670	  seconds; see the memory_corruption_check_size and
1671	  memory_corruption_check_period parameters in
1672	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1673
1674	  When enabled with the default parameters, this option has
1675	  almost no overhead, as it reserves a relatively small amount
1676	  of memory and scans it infrequently.  It both detects corruption
1677	  and prevents it from affecting the running system.
1678
1679	  It is, however, intended as a diagnostic tool; if repeatable
1680	  BIOS-originated corruption always affects the same memory,
1681	  you can use memmap= to prevent the kernel from using that
1682	  memory.
1683
1684config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1685	bool "Set the default setting of memory_corruption_check"
1686	depends on X86_CHECK_BIOS_CORRUPTION
1687	default y
1688	help
1689	  Set whether the default state of memory_corruption_check is
1690	  on or off.
1691
1692config X86_RESERVE_LOW
1693	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1694	default 64
1695	range 4 640
1696	help
1697	  Specify the amount of low memory to reserve for the BIOS.
1698
1699	  The first page contains BIOS data structures that the kernel
1700	  must not use, so that page must always be reserved.
1701
1702	  By default we reserve the first 64K of physical RAM, as a
1703	  number of BIOSes are known to corrupt that memory range
1704	  during events such as suspend/resume or monitor cable
1705	  insertion, so it must not be used by the kernel.
1706
1707	  You can set this to 4 if you are absolutely sure that you
1708	  trust the BIOS to get all its memory reservations and usages
1709	  right.  If you know your BIOS have problems beyond the
1710	  default 64K area, you can set this to 640 to avoid using the
1711	  entire low memory range.
1712
1713	  If you have doubts about the BIOS (e.g. suspend/resume does
1714	  not work or there's kernel crashes after certain hardware
1715	  hotplug events) then you might want to enable
1716	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1717	  typical corruption patterns.
1718
1719	  Leave this to the default value of 64 if you are unsure.
1720
1721config MATH_EMULATION
1722	bool
1723	depends on MODIFY_LDT_SYSCALL
1724	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1725	help
1726	  Linux can emulate a math coprocessor (used for floating point
1727	  operations) if you don't have one. 486DX and Pentium processors have
1728	  a math coprocessor built in, 486SX and 386 do not, unless you added
1729	  a 487DX or 387, respectively. (The messages during boot time can
1730	  give you some hints here ["man dmesg"].) Everyone needs either a
1731	  coprocessor or this emulation.
1732
1733	  If you don't have a math coprocessor, you need to say Y here; if you
1734	  say Y here even though you have a coprocessor, the coprocessor will
1735	  be used nevertheless. (This behavior can be changed with the kernel
1736	  command line option "no387", which comes handy if your coprocessor
1737	  is broken. Try "man bootparam" or see the documentation of your boot
1738	  loader (lilo or loadlin) about how to pass options to the kernel at
1739	  boot time.) This means that it is a good idea to say Y here if you
1740	  intend to use this kernel on different machines.
1741
1742	  More information about the internals of the Linux math coprocessor
1743	  emulation can be found in <file:arch/x86/math-emu/README>.
1744
1745	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1746	  kernel, it won't hurt.
1747
1748config MTRR
1749	def_bool y
1750	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1751	help
1752	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1753	  the Memory Type Range Registers (MTRRs) may be used to control
1754	  processor access to memory ranges. This is most useful if you have
1755	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1756	  allows bus write transfers to be combined into a larger transfer
1757	  before bursting over the PCI/AGP bus. This can increase performance
1758	  of image write operations 2.5 times or more. Saying Y here creates a
1759	  /proc/mtrr file which may be used to manipulate your processor's
1760	  MTRRs. Typically the X server should use this.
1761
1762	  This code has a reasonably generic interface so that similar
1763	  control registers on other processors can be easily supported
1764	  as well:
1765
1766	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1767	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1768	  these, the ARRs are used to emulate the MTRRs.
1769	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1770	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1771	  write-combining. All of these processors are supported by this code
1772	  and it makes sense to say Y here if you have one of them.
1773
1774	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1775	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1776	  can lead to all sorts of problems, so it's good to say Y here.
1777
1778	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1779	  just add about 9 KB to your kernel.
1780
1781	  See <file:Documentation/x86/mtrr.rst> for more information.
1782
1783config MTRR_SANITIZER
1784	def_bool y
1785	prompt "MTRR cleanup support"
1786	depends on MTRR
1787	help
1788	  Convert MTRR layout from continuous to discrete, so X drivers can
1789	  add writeback entries.
1790
1791	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1792	  The largest mtrr entry size for a continuous block can be set with
1793	  mtrr_chunk_size.
1794
1795	  If unsure, say Y.
1796
1797config MTRR_SANITIZER_ENABLE_DEFAULT
1798	int "MTRR cleanup enable value (0-1)"
1799	range 0 1
1800	default "0"
1801	depends on MTRR_SANITIZER
1802	help
1803	  Enable mtrr cleanup default value
1804
1805config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1806	int "MTRR cleanup spare reg num (0-7)"
1807	range 0 7
1808	default "1"
1809	depends on MTRR_SANITIZER
1810	help
1811	  mtrr cleanup spare entries default, it can be changed via
1812	  mtrr_spare_reg_nr=N on the kernel command line.
1813
1814config X86_PAT
1815	def_bool y
1816	prompt "x86 PAT support" if EXPERT
1817	depends on MTRR
1818	help
1819	  Use PAT attributes to setup page level cache control.
1820
1821	  PATs are the modern equivalents of MTRRs and are much more
1822	  flexible than MTRRs.
1823
1824	  Say N here if you see bootup problems (boot crash, boot hang,
1825	  spontaneous reboots) or a non-working video driver.
1826
1827	  If unsure, say Y.
1828
1829config ARCH_USES_PG_UNCACHED
1830	def_bool y
1831	depends on X86_PAT
1832
1833config ARCH_RANDOM
1834	def_bool y
1835	prompt "x86 architectural random number generator" if EXPERT
1836	help
1837	  Enable the x86 architectural RDRAND instruction
1838	  (Intel Bull Mountain technology) to generate random numbers.
1839	  If supported, this is a high bandwidth, cryptographically
1840	  secure hardware random number generator.
1841
1842config X86_SMAP
1843	def_bool y
1844	prompt "Supervisor Mode Access Prevention" if EXPERT
1845	help
1846	  Supervisor Mode Access Prevention (SMAP) is a security
1847	  feature in newer Intel processors.  There is a small
1848	  performance cost if this enabled and turned on; there is
1849	  also a small increase in the kernel size if this is enabled.
1850
1851	  If unsure, say Y.
1852
1853config X86_UMIP
1854	def_bool y
1855	prompt "User Mode Instruction Prevention" if EXPERT
1856	help
1857	  User Mode Instruction Prevention (UMIP) is a security feature in
1858	  some x86 processors. If enabled, a general protection fault is
1859	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1860	  executed in user mode. These instructions unnecessarily expose
1861	  information about the hardware state.
1862
1863	  The vast majority of applications do not use these instructions.
1864	  For the very few that do, software emulation is provided in
1865	  specific cases in protected and virtual-8086 modes. Emulated
1866	  results are dummy.
1867
1868config X86_INTEL_MEMORY_PROTECTION_KEYS
1869	prompt "Memory Protection Keys"
1870	def_bool y
1871	# Note: only available in 64-bit mode
1872	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1873	select ARCH_USES_HIGH_VMA_FLAGS
1874	select ARCH_HAS_PKEYS
1875	help
1876	  Memory Protection Keys provides a mechanism for enforcing
1877	  page-based protections, but without requiring modification of the
1878	  page tables when an application changes protection domains.
1879
1880	  For details, see Documentation/core-api/protection-keys.rst
1881
1882	  If unsure, say y.
1883
1884choice
1885	prompt "TSX enable mode"
1886	depends on CPU_SUP_INTEL
1887	default X86_INTEL_TSX_MODE_OFF
1888	help
1889	  Intel's TSX (Transactional Synchronization Extensions) feature
1890	  allows to optimize locking protocols through lock elision which
1891	  can lead to a noticeable performance boost.
1892
1893	  On the other hand it has been shown that TSX can be exploited
1894	  to form side channel attacks (e.g. TAA) and chances are there
1895	  will be more of those attacks discovered in the future.
1896
1897	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1898	  might override this decision by tsx=on the command line parameter.
1899	  Even with TSX enabled, the kernel will attempt to enable the best
1900	  possible TAA mitigation setting depending on the microcode available
1901	  for the particular machine.
1902
1903	  This option allows to set the default tsx mode between tsx=on, =off
1904	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1905	  details.
1906
1907	  Say off if not sure, auto if TSX is in use but it should be used on safe
1908	  platforms or on if TSX is in use and the security aspect of tsx is not
1909	  relevant.
1910
1911config X86_INTEL_TSX_MODE_OFF
1912	bool "off"
1913	help
1914	  TSX is disabled if possible - equals to tsx=off command line parameter.
1915
1916config X86_INTEL_TSX_MODE_ON
1917	bool "on"
1918	help
1919	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1920	  line parameter.
1921
1922config X86_INTEL_TSX_MODE_AUTO
1923	bool "auto"
1924	help
1925	  TSX is enabled on TSX capable HW that is believed to be safe against
1926	  side channel attacks- equals the tsx=auto command line parameter.
1927endchoice
1928
1929config EFI
1930	bool "EFI runtime service support"
1931	depends on ACPI
1932	select UCS2_STRING
1933	select EFI_RUNTIME_WRAPPERS
1934	help
1935	  This enables the kernel to use EFI runtime services that are
1936	  available (such as the EFI variable services).
1937
1938	  This option is only useful on systems that have EFI firmware.
1939	  In addition, you should use the latest ELILO loader available
1940	  at <http://elilo.sourceforge.net> in order to take advantage
1941	  of EFI runtime services. However, even with this option, the
1942	  resultant kernel should continue to boot on existing non-EFI
1943	  platforms.
1944
1945config EFI_STUB
1946	bool "EFI stub support"
1947	depends on EFI && !X86_USE_3DNOW
1948	depends on $(cc-option,-mabi=ms) || X86_32
1949	select RELOCATABLE
1950	help
1951	  This kernel feature allows a bzImage to be loaded directly
1952	  by EFI firmware without the use of a bootloader.
1953
1954	  See Documentation/admin-guide/efi-stub.rst for more information.
1955
1956config EFI_MIXED
1957	bool "EFI mixed-mode support"
1958	depends on EFI_STUB && X86_64
1959	help
1960	   Enabling this feature allows a 64-bit kernel to be booted
1961	   on a 32-bit firmware, provided that your CPU supports 64-bit
1962	   mode.
1963
1964	   Note that it is not possible to boot a mixed-mode enabled
1965	   kernel via the EFI boot stub - a bootloader that supports
1966	   the EFI handover protocol must be used.
1967
1968	   If unsure, say N.
1969
1970config SECCOMP
1971	def_bool y
1972	prompt "Enable seccomp to safely compute untrusted bytecode"
1973	help
1974	  This kernel feature is useful for number crunching applications
1975	  that may need to compute untrusted bytecode during their
1976	  execution. By using pipes or other transports made available to
1977	  the process as file descriptors supporting the read/write
1978	  syscalls, it's possible to isolate those applications in
1979	  their own address space using seccomp. Once seccomp is
1980	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1981	  and the task is only allowed to execute a few safe syscalls
1982	  defined by each seccomp mode.
1983
1984	  If unsure, say Y. Only embedded should say N here.
1985
1986source "kernel/Kconfig.hz"
1987
1988config KEXEC
1989	bool "kexec system call"
1990	select KEXEC_CORE
1991	help
1992	  kexec is a system call that implements the ability to shutdown your
1993	  current kernel, and to start another kernel.  It is like a reboot
1994	  but it is independent of the system firmware.   And like a reboot
1995	  you can start any kernel with it, not just Linux.
1996
1997	  The name comes from the similarity to the exec system call.
1998
1999	  It is an ongoing process to be certain the hardware in a machine
2000	  is properly shutdown, so do not be surprised if this code does not
2001	  initially work for you.  As of this writing the exact hardware
2002	  interface is strongly in flux, so no good recommendation can be
2003	  made.
2004
2005config KEXEC_FILE
2006	bool "kexec file based system call"
2007	select KEXEC_CORE
2008	select BUILD_BIN2C
2009	depends on X86_64
2010	depends on CRYPTO=y
2011	depends on CRYPTO_SHA256=y
2012	help
2013	  This is new version of kexec system call. This system call is
2014	  file based and takes file descriptors as system call argument
2015	  for kernel and initramfs as opposed to list of segments as
2016	  accepted by previous system call.
2017
2018config ARCH_HAS_KEXEC_PURGATORY
2019	def_bool KEXEC_FILE
2020
2021config KEXEC_SIG
2022	bool "Verify kernel signature during kexec_file_load() syscall"
2023	depends on KEXEC_FILE
2024	help
2025
2026	  This option makes the kexec_file_load() syscall check for a valid
2027	  signature of the kernel image.  The image can still be loaded without
2028	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2029	  there's a signature that we can check, then it must be valid.
2030
2031	  In addition to this option, you need to enable signature
2032	  verification for the corresponding kernel image type being
2033	  loaded in order for this to work.
2034
2035config KEXEC_SIG_FORCE
2036	bool "Require a valid signature in kexec_file_load() syscall"
2037	depends on KEXEC_SIG
2038	help
2039	  This option makes kernel signature verification mandatory for
2040	  the kexec_file_load() syscall.
2041
2042config KEXEC_BZIMAGE_VERIFY_SIG
2043	bool "Enable bzImage signature verification support"
2044	depends on KEXEC_SIG
2045	depends on SIGNED_PE_FILE_VERIFICATION
2046	select SYSTEM_TRUSTED_KEYRING
2047	help
2048	  Enable bzImage signature verification support.
2049
2050config CRASH_DUMP
2051	bool "kernel crash dumps"
2052	depends on X86_64 || (X86_32 && HIGHMEM)
2053	help
2054	  Generate crash dump after being started by kexec.
2055	  This should be normally only set in special crash dump kernels
2056	  which are loaded in the main kernel with kexec-tools into
2057	  a specially reserved region and then later executed after
2058	  a crash by kdump/kexec. The crash dump kernel must be compiled
2059	  to a memory address not used by the main kernel or BIOS using
2060	  PHYSICAL_START, or it must be built as a relocatable image
2061	  (CONFIG_RELOCATABLE=y).
2062	  For more details see Documentation/admin-guide/kdump/kdump.rst
2063
2064config KEXEC_JUMP
2065	bool "kexec jump"
2066	depends on KEXEC && HIBERNATION
2067	help
2068	  Jump between original kernel and kexeced kernel and invoke
2069	  code in physical address mode via KEXEC
2070
2071config PHYSICAL_START
2072	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2073	default "0x1000000"
2074	help
2075	  This gives the physical address where the kernel is loaded.
2076
2077	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2078	  bzImage will decompress itself to above physical address and
2079	  run from there. Otherwise, bzImage will run from the address where
2080	  it has been loaded by the boot loader and will ignore above physical
2081	  address.
2082
2083	  In normal kdump cases one does not have to set/change this option
2084	  as now bzImage can be compiled as a completely relocatable image
2085	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2086	  address. This option is mainly useful for the folks who don't want
2087	  to use a bzImage for capturing the crash dump and want to use a
2088	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2089	  to be specifically compiled to run from a specific memory area
2090	  (normally a reserved region) and this option comes handy.
2091
2092	  So if you are using bzImage for capturing the crash dump,
2093	  leave the value here unchanged to 0x1000000 and set
2094	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2095	  for capturing the crash dump change this value to start of
2096	  the reserved region.  In other words, it can be set based on
2097	  the "X" value as specified in the "crashkernel=YM@XM"
2098	  command line boot parameter passed to the panic-ed
2099	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2100	  for more details about crash dumps.
2101
2102	  Usage of bzImage for capturing the crash dump is recommended as
2103	  one does not have to build two kernels. Same kernel can be used
2104	  as production kernel and capture kernel. Above option should have
2105	  gone away after relocatable bzImage support is introduced. But it
2106	  is present because there are users out there who continue to use
2107	  vmlinux for dump capture. This option should go away down the
2108	  line.
2109
2110	  Don't change this unless you know what you are doing.
2111
2112config RELOCATABLE
2113	bool "Build a relocatable kernel"
2114	default y
2115	help
2116	  This builds a kernel image that retains relocation information
2117	  so it can be loaded someplace besides the default 1MB.
2118	  The relocations tend to make the kernel binary about 10% larger,
2119	  but are discarded at runtime.
2120
2121	  One use is for the kexec on panic case where the recovery kernel
2122	  must live at a different physical address than the primary
2123	  kernel.
2124
2125	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2126	  it has been loaded at and the compile time physical address
2127	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2128
2129config RANDOMIZE_BASE
2130	bool "Randomize the address of the kernel image (KASLR)"
2131	depends on RELOCATABLE
2132	default y
2133	help
2134	  In support of Kernel Address Space Layout Randomization (KASLR),
2135	  this randomizes the physical address at which the kernel image
2136	  is decompressed and the virtual address where the kernel
2137	  image is mapped, as a security feature that deters exploit
2138	  attempts relying on knowledge of the location of kernel
2139	  code internals.
2140
2141	  On 64-bit, the kernel physical and virtual addresses are
2142	  randomized separately. The physical address will be anywhere
2143	  between 16MB and the top of physical memory (up to 64TB). The
2144	  virtual address will be randomized from 16MB up to 1GB (9 bits
2145	  of entropy). Note that this also reduces the memory space
2146	  available to kernel modules from 1.5GB to 1GB.
2147
2148	  On 32-bit, the kernel physical and virtual addresses are
2149	  randomized together. They will be randomized from 16MB up to
2150	  512MB (8 bits of entropy).
2151
2152	  Entropy is generated using the RDRAND instruction if it is
2153	  supported. If RDTSC is supported, its value is mixed into
2154	  the entropy pool as well. If neither RDRAND nor RDTSC are
2155	  supported, then entropy is read from the i8254 timer. The
2156	  usable entropy is limited by the kernel being built using
2157	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2158	  minimum of 2MB. As a result, only 10 bits of entropy are
2159	  theoretically possible, but the implementations are further
2160	  limited due to memory layouts.
2161
2162	  If unsure, say Y.
2163
2164# Relocation on x86 needs some additional build support
2165config X86_NEED_RELOCS
2166	def_bool y
2167	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2168
2169config PHYSICAL_ALIGN
2170	hex "Alignment value to which kernel should be aligned"
2171	default "0x200000"
2172	range 0x2000 0x1000000 if X86_32
2173	range 0x200000 0x1000000 if X86_64
2174	help
2175	  This value puts the alignment restrictions on physical address
2176	  where kernel is loaded and run from. Kernel is compiled for an
2177	  address which meets above alignment restriction.
2178
2179	  If bootloader loads the kernel at a non-aligned address and
2180	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2181	  address aligned to above value and run from there.
2182
2183	  If bootloader loads the kernel at a non-aligned address and
2184	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2185	  load address and decompress itself to the address it has been
2186	  compiled for and run from there. The address for which kernel is
2187	  compiled already meets above alignment restrictions. Hence the
2188	  end result is that kernel runs from a physical address meeting
2189	  above alignment restrictions.
2190
2191	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2192	  this value must be a multiple of 0x200000.
2193
2194	  Don't change this unless you know what you are doing.
2195
2196config DYNAMIC_MEMORY_LAYOUT
2197	bool
2198	help
2199	  This option makes base addresses of vmalloc and vmemmap as well as
2200	  __PAGE_OFFSET movable during boot.
2201
2202config RANDOMIZE_MEMORY
2203	bool "Randomize the kernel memory sections"
2204	depends on X86_64
2205	depends on RANDOMIZE_BASE
2206	select DYNAMIC_MEMORY_LAYOUT
2207	default RANDOMIZE_BASE
2208	help
2209	   Randomizes the base virtual address of kernel memory sections
2210	   (physical memory mapping, vmalloc & vmemmap). This security feature
2211	   makes exploits relying on predictable memory locations less reliable.
2212
2213	   The order of allocations remains unchanged. Entropy is generated in
2214	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2215	   configuration have in average 30,000 different possible virtual
2216	   addresses for each memory section.
2217
2218	   If unsure, say Y.
2219
2220config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2221	hex "Physical memory mapping padding" if EXPERT
2222	depends on RANDOMIZE_MEMORY
2223	default "0xa" if MEMORY_HOTPLUG
2224	default "0x0"
2225	range 0x1 0x40 if MEMORY_HOTPLUG
2226	range 0x0 0x40
2227	help
2228	   Define the padding in terabytes added to the existing physical
2229	   memory size during kernel memory randomization. It is useful
2230	   for memory hotplug support but reduces the entropy available for
2231	   address randomization.
2232
2233	   If unsure, leave at the default value.
2234
2235config HOTPLUG_CPU
2236	def_bool y
2237	depends on SMP
2238
2239config BOOTPARAM_HOTPLUG_CPU0
2240	bool "Set default setting of cpu0_hotpluggable"
2241	depends on HOTPLUG_CPU
2242	help
2243	  Set whether default state of cpu0_hotpluggable is on or off.
2244
2245	  Say Y here to enable CPU0 hotplug by default. If this switch
2246	  is turned on, there is no need to give cpu0_hotplug kernel
2247	  parameter and the CPU0 hotplug feature is enabled by default.
2248
2249	  Please note: there are two known CPU0 dependencies if you want
2250	  to enable the CPU0 hotplug feature either by this switch or by
2251	  cpu0_hotplug kernel parameter.
2252
2253	  First, resume from hibernate or suspend always starts from CPU0.
2254	  So hibernate and suspend are prevented if CPU0 is offline.
2255
2256	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2257	  offline if any interrupt can not migrate out of CPU0. There may
2258	  be other CPU0 dependencies.
2259
2260	  Please make sure the dependencies are under your control before
2261	  you enable this feature.
2262
2263	  Say N if you don't want to enable CPU0 hotplug feature by default.
2264	  You still can enable the CPU0 hotplug feature at boot by kernel
2265	  parameter cpu0_hotplug.
2266
2267config DEBUG_HOTPLUG_CPU0
2268	def_bool n
2269	prompt "Debug CPU0 hotplug"
2270	depends on HOTPLUG_CPU
2271	help
2272	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2273	  soon as possible and boots up userspace with CPU0 offlined. User
2274	  can online CPU0 back after boot time.
2275
2276	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2277	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2278	  compilation or giving cpu0_hotplug kernel parameter at boot.
2279
2280	  If unsure, say N.
2281
2282config COMPAT_VDSO
2283	def_bool n
2284	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2285	depends on COMPAT_32
2286	help
2287	  Certain buggy versions of glibc will crash if they are
2288	  presented with a 32-bit vDSO that is not mapped at the address
2289	  indicated in its segment table.
2290
2291	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2292	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2293	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2294	  the only released version with the bug, but OpenSUSE 9
2295	  contains a buggy "glibc 2.3.2".
2296
2297	  The symptom of the bug is that everything crashes on startup, saying:
2298	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2299
2300	  Saying Y here changes the default value of the vdso32 boot
2301	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2302	  This works around the glibc bug but hurts performance.
2303
2304	  If unsure, say N: if you are compiling your own kernel, you
2305	  are unlikely to be using a buggy version of glibc.
2306
2307choice
2308	prompt "vsyscall table for legacy applications"
2309	depends on X86_64
2310	default LEGACY_VSYSCALL_XONLY
2311	help
2312	  Legacy user code that does not know how to find the vDSO expects
2313	  to be able to issue three syscalls by calling fixed addresses in
2314	  kernel space. Since this location is not randomized with ASLR,
2315	  it can be used to assist security vulnerability exploitation.
2316
2317	  This setting can be changed at boot time via the kernel command
2318	  line parameter vsyscall=[emulate|xonly|none].
2319
2320	  On a system with recent enough glibc (2.14 or newer) and no
2321	  static binaries, you can say None without a performance penalty
2322	  to improve security.
2323
2324	  If unsure, select "Emulate execution only".
2325
2326	config LEGACY_VSYSCALL_EMULATE
2327		bool "Full emulation"
2328		help
2329		  The kernel traps and emulates calls into the fixed vsyscall
2330		  address mapping. This makes the mapping non-executable, but
2331		  it still contains readable known contents, which could be
2332		  used in certain rare security vulnerability exploits. This
2333		  configuration is recommended when using legacy userspace
2334		  that still uses vsyscalls along with legacy binary
2335		  instrumentation tools that require code to be readable.
2336
2337		  An example of this type of legacy userspace is running
2338		  Pin on an old binary that still uses vsyscalls.
2339
2340	config LEGACY_VSYSCALL_XONLY
2341		bool "Emulate execution only"
2342		help
2343		  The kernel traps and emulates calls into the fixed vsyscall
2344		  address mapping and does not allow reads.  This
2345		  configuration is recommended when userspace might use the
2346		  legacy vsyscall area but support for legacy binary
2347		  instrumentation of legacy code is not needed.  It mitigates
2348		  certain uses of the vsyscall area as an ASLR-bypassing
2349		  buffer.
2350
2351	config LEGACY_VSYSCALL_NONE
2352		bool "None"
2353		help
2354		  There will be no vsyscall mapping at all. This will
2355		  eliminate any risk of ASLR bypass due to the vsyscall
2356		  fixed address mapping. Attempts to use the vsyscalls
2357		  will be reported to dmesg, so that either old or
2358		  malicious userspace programs can be identified.
2359
2360endchoice
2361
2362config CMDLINE_BOOL
2363	bool "Built-in kernel command line"
2364	help
2365	  Allow for specifying boot arguments to the kernel at
2366	  build time.  On some systems (e.g. embedded ones), it is
2367	  necessary or convenient to provide some or all of the
2368	  kernel boot arguments with the kernel itself (that is,
2369	  to not rely on the boot loader to provide them.)
2370
2371	  To compile command line arguments into the kernel,
2372	  set this option to 'Y', then fill in the
2373	  boot arguments in CONFIG_CMDLINE.
2374
2375	  Systems with fully functional boot loaders (i.e. non-embedded)
2376	  should leave this option set to 'N'.
2377
2378config CMDLINE
2379	string "Built-in kernel command string"
2380	depends on CMDLINE_BOOL
2381	default ""
2382	help
2383	  Enter arguments here that should be compiled into the kernel
2384	  image and used at boot time.  If the boot loader provides a
2385	  command line at boot time, it is appended to this string to
2386	  form the full kernel command line, when the system boots.
2387
2388	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2389	  change this behavior.
2390
2391	  In most cases, the command line (whether built-in or provided
2392	  by the boot loader) should specify the device for the root
2393	  file system.
2394
2395config CMDLINE_OVERRIDE
2396	bool "Built-in command line overrides boot loader arguments"
2397	depends on CMDLINE_BOOL && CMDLINE != ""
2398	help
2399	  Set this option to 'Y' to have the kernel ignore the boot loader
2400	  command line, and use ONLY the built-in command line.
2401
2402	  This is used to work around broken boot loaders.  This should
2403	  be set to 'N' under normal conditions.
2404
2405config MODIFY_LDT_SYSCALL
2406	bool "Enable the LDT (local descriptor table)" if EXPERT
2407	default y
2408	help
2409	  Linux can allow user programs to install a per-process x86
2410	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2411	  call.  This is required to run 16-bit or segmented code such as
2412	  DOSEMU or some Wine programs.  It is also used by some very old
2413	  threading libraries.
2414
2415	  Enabling this feature adds a small amount of overhead to
2416	  context switches and increases the low-level kernel attack
2417	  surface.  Disabling it removes the modify_ldt(2) system call.
2418
2419	  Saying 'N' here may make sense for embedded or server kernels.
2420
2421source "kernel/livepatch/Kconfig"
2422
2423endmenu
2424
2425config ARCH_HAS_ADD_PAGES
2426	def_bool y
2427	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2428
2429config ARCH_ENABLE_MEMORY_HOTPLUG
2430	def_bool y
2431	depends on X86_64 || (X86_32 && HIGHMEM)
2432
2433config ARCH_ENABLE_MEMORY_HOTREMOVE
2434	def_bool y
2435	depends on MEMORY_HOTPLUG
2436
2437config USE_PERCPU_NUMA_NODE_ID
2438	def_bool y
2439	depends on NUMA
2440
2441config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2442	def_bool y
2443	depends on X86_64 || X86_PAE
2444
2445config ARCH_ENABLE_HUGEPAGE_MIGRATION
2446	def_bool y
2447	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2448
2449config ARCH_ENABLE_THP_MIGRATION
2450	def_bool y
2451	depends on X86_64 && TRANSPARENT_HUGEPAGE
2452
2453menu "Power management and ACPI options"
2454
2455config ARCH_HIBERNATION_HEADER
2456	def_bool y
2457	depends on HIBERNATION
2458
2459source "kernel/power/Kconfig"
2460
2461source "drivers/acpi/Kconfig"
2462
2463source "drivers/sfi/Kconfig"
2464
2465config X86_APM_BOOT
2466	def_bool y
2467	depends on APM
2468
2469menuconfig APM
2470	tristate "APM (Advanced Power Management) BIOS support"
2471	depends on X86_32 && PM_SLEEP
2472	help
2473	  APM is a BIOS specification for saving power using several different
2474	  techniques. This is mostly useful for battery powered laptops with
2475	  APM compliant BIOSes. If you say Y here, the system time will be
2476	  reset after a RESUME operation, the /proc/apm device will provide
2477	  battery status information, and user-space programs will receive
2478	  notification of APM "events" (e.g. battery status change).
2479
2480	  If you select "Y" here, you can disable actual use of the APM
2481	  BIOS by passing the "apm=off" option to the kernel at boot time.
2482
2483	  Note that the APM support is almost completely disabled for
2484	  machines with more than one CPU.
2485
2486	  In order to use APM, you will need supporting software. For location
2487	  and more information, read <file:Documentation/power/apm-acpi.rst>
2488	  and the Battery Powered Linux mini-HOWTO, available from
2489	  <http://www.tldp.org/docs.html#howto>.
2490
2491	  This driver does not spin down disk drives (see the hdparm(8)
2492	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2493	  VESA-compliant "green" monitors.
2494
2495	  This driver does not support the TI 4000M TravelMate and the ACER
2496	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2497	  desktop machines also don't have compliant BIOSes, and this driver
2498	  may cause those machines to panic during the boot phase.
2499
2500	  Generally, if you don't have a battery in your machine, there isn't
2501	  much point in using this driver and you should say N. If you get
2502	  random kernel OOPSes or reboots that don't seem to be related to
2503	  anything, try disabling/enabling this option (or disabling/enabling
2504	  APM in your BIOS).
2505
2506	  Some other things you should try when experiencing seemingly random,
2507	  "weird" problems:
2508
2509	  1) make sure that you have enough swap space and that it is
2510	  enabled.
2511	  2) pass the "no-hlt" option to the kernel
2512	  3) switch on floating point emulation in the kernel and pass
2513	  the "no387" option to the kernel
2514	  4) pass the "floppy=nodma" option to the kernel
2515	  5) pass the "mem=4M" option to the kernel (thereby disabling
2516	  all but the first 4 MB of RAM)
2517	  6) make sure that the CPU is not over clocked.
2518	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2519	  8) disable the cache from your BIOS settings
2520	  9) install a fan for the video card or exchange video RAM
2521	  10) install a better fan for the CPU
2522	  11) exchange RAM chips
2523	  12) exchange the motherboard.
2524
2525	  To compile this driver as a module, choose M here: the
2526	  module will be called apm.
2527
2528if APM
2529
2530config APM_IGNORE_USER_SUSPEND
2531	bool "Ignore USER SUSPEND"
2532	help
2533	  This option will ignore USER SUSPEND requests. On machines with a
2534	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2535	  series notebooks, it is necessary to say Y because of a BIOS bug.
2536
2537config APM_DO_ENABLE
2538	bool "Enable PM at boot time"
2539	help
2540	  Enable APM features at boot time. From page 36 of the APM BIOS
2541	  specification: "When disabled, the APM BIOS does not automatically
2542	  power manage devices, enter the Standby State, enter the Suspend
2543	  State, or take power saving steps in response to CPU Idle calls."
2544	  This driver will make CPU Idle calls when Linux is idle (unless this
2545	  feature is turned off -- see "Do CPU IDLE calls", below). This
2546	  should always save battery power, but more complicated APM features
2547	  will be dependent on your BIOS implementation. You may need to turn
2548	  this option off if your computer hangs at boot time when using APM
2549	  support, or if it beeps continuously instead of suspending. Turn
2550	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2551	  T400CDT. This is off by default since most machines do fine without
2552	  this feature.
2553
2554config APM_CPU_IDLE
2555	depends on CPU_IDLE
2556	bool "Make CPU Idle calls when idle"
2557	help
2558	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2559	  On some machines, this can activate improved power savings, such as
2560	  a slowed CPU clock rate, when the machine is idle. These idle calls
2561	  are made after the idle loop has run for some length of time (e.g.,
2562	  333 mS). On some machines, this will cause a hang at boot time or
2563	  whenever the CPU becomes idle. (On machines with more than one CPU,
2564	  this option does nothing.)
2565
2566config APM_DISPLAY_BLANK
2567	bool "Enable console blanking using APM"
2568	help
2569	  Enable console blanking using the APM. Some laptops can use this to
2570	  turn off the LCD backlight when the screen blanker of the Linux
2571	  virtual console blanks the screen. Note that this is only used by
2572	  the virtual console screen blanker, and won't turn off the backlight
2573	  when using the X Window system. This also doesn't have anything to
2574	  do with your VESA-compliant power-saving monitor. Further, this
2575	  option doesn't work for all laptops -- it might not turn off your
2576	  backlight at all, or it might print a lot of errors to the console,
2577	  especially if you are using gpm.
2578
2579config APM_ALLOW_INTS
2580	bool "Allow interrupts during APM BIOS calls"
2581	help
2582	  Normally we disable external interrupts while we are making calls to
2583	  the APM BIOS as a measure to lessen the effects of a badly behaving
2584	  BIOS implementation.  The BIOS should reenable interrupts if it
2585	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2586	  many of the newer IBM Thinkpads.  If you experience hangs when you
2587	  suspend, try setting this to Y.  Otherwise, say N.
2588
2589endif # APM
2590
2591source "drivers/cpufreq/Kconfig"
2592
2593source "drivers/cpuidle/Kconfig"
2594
2595source "drivers/idle/Kconfig"
2596
2597endmenu
2598
2599
2600menu "Bus options (PCI etc.)"
2601
2602choice
2603	prompt "PCI access mode"
2604	depends on X86_32 && PCI
2605	default PCI_GOANY
2606	help
2607	  On PCI systems, the BIOS can be used to detect the PCI devices and
2608	  determine their configuration. However, some old PCI motherboards
2609	  have BIOS bugs and may crash if this is done. Also, some embedded
2610	  PCI-based systems don't have any BIOS at all. Linux can also try to
2611	  detect the PCI hardware directly without using the BIOS.
2612
2613	  With this option, you can specify how Linux should detect the
2614	  PCI devices. If you choose "BIOS", the BIOS will be used,
2615	  if you choose "Direct", the BIOS won't be used, and if you
2616	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2617	  If you choose "Any", the kernel will try MMCONFIG, then the
2618	  direct access method and falls back to the BIOS if that doesn't
2619	  work. If unsure, go with the default, which is "Any".
2620
2621config PCI_GOBIOS
2622	bool "BIOS"
2623
2624config PCI_GOMMCONFIG
2625	bool "MMConfig"
2626
2627config PCI_GODIRECT
2628	bool "Direct"
2629
2630config PCI_GOOLPC
2631	bool "OLPC XO-1"
2632	depends on OLPC
2633
2634config PCI_GOANY
2635	bool "Any"
2636
2637endchoice
2638
2639config PCI_BIOS
2640	def_bool y
2641	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2642
2643# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2644config PCI_DIRECT
2645	def_bool y
2646	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2647
2648config PCI_MMCONFIG
2649	bool "Support mmconfig PCI config space access" if X86_64
2650	default y
2651	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2652	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2653
2654config PCI_OLPC
2655	def_bool y
2656	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2657
2658config PCI_XEN
2659	def_bool y
2660	depends on PCI && XEN
2661	select SWIOTLB_XEN
2662
2663config MMCONF_FAM10H
2664	def_bool y
2665	depends on X86_64 && PCI_MMCONFIG && ACPI
2666
2667config PCI_CNB20LE_QUIRK
2668	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2669	depends on PCI
2670	help
2671	  Read the PCI windows out of the CNB20LE host bridge. This allows
2672	  PCI hotplug to work on systems with the CNB20LE chipset which do
2673	  not have ACPI.
2674
2675	  There's no public spec for this chipset, and this functionality
2676	  is known to be incomplete.
2677
2678	  You should say N unless you know you need this.
2679
2680config ISA_BUS
2681	bool "ISA bus support on modern systems" if EXPERT
2682	help
2683	  Expose ISA bus device drivers and options available for selection and
2684	  configuration. Enable this option if your target machine has an ISA
2685	  bus. ISA is an older system, displaced by PCI and newer bus
2686	  architectures -- if your target machine is modern, it probably does
2687	  not have an ISA bus.
2688
2689	  If unsure, say N.
2690
2691# x86_64 have no ISA slots, but can have ISA-style DMA.
2692config ISA_DMA_API
2693	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2694	default y
2695	help
2696	  Enables ISA-style DMA support for devices requiring such controllers.
2697	  If unsure, say Y.
2698
2699if X86_32
2700
2701config ISA
2702	bool "ISA support"
2703	help
2704	  Find out whether you have ISA slots on your motherboard.  ISA is the
2705	  name of a bus system, i.e. the way the CPU talks to the other stuff
2706	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2707	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2708	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2709
2710config SCx200
2711	tristate "NatSemi SCx200 support"
2712	help
2713	  This provides basic support for National Semiconductor's
2714	  (now AMD's) Geode processors.  The driver probes for the
2715	  PCI-IDs of several on-chip devices, so its a good dependency
2716	  for other scx200_* drivers.
2717
2718	  If compiled as a module, the driver is named scx200.
2719
2720config SCx200HR_TIMER
2721	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2722	depends on SCx200
2723	default y
2724	help
2725	  This driver provides a clocksource built upon the on-chip
2726	  27MHz high-resolution timer.  Its also a workaround for
2727	  NSC Geode SC-1100's buggy TSC, which loses time when the
2728	  processor goes idle (as is done by the scheduler).  The
2729	  other workaround is idle=poll boot option.
2730
2731config OLPC
2732	bool "One Laptop Per Child support"
2733	depends on !X86_PAE
2734	select GPIOLIB
2735	select OF
2736	select OF_PROMTREE
2737	select IRQ_DOMAIN
2738	select OLPC_EC
2739	help
2740	  Add support for detecting the unique features of the OLPC
2741	  XO hardware.
2742
2743config OLPC_XO1_PM
2744	bool "OLPC XO-1 Power Management"
2745	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2746	help
2747	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2748
2749config OLPC_XO1_RTC
2750	bool "OLPC XO-1 Real Time Clock"
2751	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2752	help
2753	  Add support for the XO-1 real time clock, which can be used as a
2754	  programmable wakeup source.
2755
2756config OLPC_XO1_SCI
2757	bool "OLPC XO-1 SCI extras"
2758	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2759	depends on INPUT=y
2760	select POWER_SUPPLY
2761	help
2762	  Add support for SCI-based features of the OLPC XO-1 laptop:
2763	   - EC-driven system wakeups
2764	   - Power button
2765	   - Ebook switch
2766	   - Lid switch
2767	   - AC adapter status updates
2768	   - Battery status updates
2769
2770config OLPC_XO15_SCI
2771	bool "OLPC XO-1.5 SCI extras"
2772	depends on OLPC && ACPI
2773	select POWER_SUPPLY
2774	help
2775	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2776	   - EC-driven system wakeups
2777	   - AC adapter status updates
2778	   - Battery status updates
2779
2780config ALIX
2781	bool "PCEngines ALIX System Support (LED setup)"
2782	select GPIOLIB
2783	help
2784	  This option enables system support for the PCEngines ALIX.
2785	  At present this just sets up LEDs for GPIO control on
2786	  ALIX2/3/6 boards.  However, other system specific setup should
2787	  get added here.
2788
2789	  Note: You must still enable the drivers for GPIO and LED support
2790	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2791
2792	  Note: You have to set alix.force=1 for boards with Award BIOS.
2793
2794config NET5501
2795	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2796	select GPIOLIB
2797	help
2798	  This option enables system support for the Soekris Engineering net5501.
2799
2800config GEOS
2801	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2802	select GPIOLIB
2803	depends on DMI
2804	help
2805	  This option enables system support for the Traverse Technologies GEOS.
2806
2807config TS5500
2808	bool "Technologic Systems TS-5500 platform support"
2809	depends on MELAN
2810	select CHECK_SIGNATURE
2811	select NEW_LEDS
2812	select LEDS_CLASS
2813	help
2814	  This option enables system support for the Technologic Systems TS-5500.
2815
2816endif # X86_32
2817
2818config AMD_NB
2819	def_bool y
2820	depends on CPU_SUP_AMD && PCI
2821
2822config X86_SYSFB
2823	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2824	help
2825	  Firmwares often provide initial graphics framebuffers so the BIOS,
2826	  bootloader or kernel can show basic video-output during boot for
2827	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2828	  Extensions and EFI-framebuffers for this, which are mostly limited
2829	  to x86.
2830	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2831	  framebuffers so the new generic system-framebuffer drivers can be
2832	  used on x86. If the framebuffer is not compatible with the generic
2833	  modes, it is advertised as fallback platform framebuffer so legacy
2834	  drivers like efifb, vesafb and uvesafb can pick it up.
2835	  If this option is not selected, all system framebuffers are always
2836	  marked as fallback platform framebuffers as usual.
2837
2838	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2839	  not be able to pick up generic system framebuffers if this option
2840	  is selected. You are highly encouraged to enable simplefb as
2841	  replacement if you select this option. simplefb can correctly deal
2842	  with generic system framebuffers. But you should still keep vesafb
2843	  and others enabled as fallback if a system framebuffer is
2844	  incompatible with simplefb.
2845
2846	  If unsure, say Y.
2847
2848endmenu
2849
2850
2851menu "Binary Emulations"
2852
2853config IA32_EMULATION
2854	bool "IA32 Emulation"
2855	depends on X86_64
2856	select ARCH_WANT_OLD_COMPAT_IPC
2857	select BINFMT_ELF
2858	select COMPAT_BINFMT_ELF
2859	select COMPAT_OLD_SIGACTION
2860	help
2861	  Include code to run legacy 32-bit programs under a
2862	  64-bit kernel. You should likely turn this on, unless you're
2863	  100% sure that you don't have any 32-bit programs left.
2864
2865config IA32_AOUT
2866	tristate "IA32 a.out support"
2867	depends on IA32_EMULATION
2868	depends on BROKEN
2869	help
2870	  Support old a.out binaries in the 32bit emulation.
2871
2872config X86_X32
2873	bool "x32 ABI for 64-bit mode"
2874	depends on X86_64
2875	help
2876	  Include code to run binaries for the x32 native 32-bit ABI
2877	  for 64-bit processors.  An x32 process gets access to the
2878	  full 64-bit register file and wide data path while leaving
2879	  pointers at 32 bits for smaller memory footprint.
2880
2881	  You will need a recent binutils (2.22 or later) with
2882	  elf32_x86_64 support enabled to compile a kernel with this
2883	  option set.
2884
2885config COMPAT_32
2886	def_bool y
2887	depends on IA32_EMULATION || X86_32
2888	select HAVE_UID16
2889	select OLD_SIGSUSPEND3
2890
2891config COMPAT
2892	def_bool y
2893	depends on IA32_EMULATION || X86_X32
2894
2895if COMPAT
2896config COMPAT_FOR_U64_ALIGNMENT
2897	def_bool y
2898
2899config SYSVIPC_COMPAT
2900	def_bool y
2901	depends on SYSVIPC
2902endif
2903
2904endmenu
2905
2906
2907config HAVE_ATOMIC_IOMAP
2908	def_bool y
2909	depends on X86_32
2910
2911source "drivers/firmware/Kconfig"
2912
2913source "arch/x86/kvm/Kconfig"
2914
2915source "arch/x86/Kconfig.assembler"
2916