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