xref: /linux/arch/x86/Kconfig (revision c01044cc819160323f3ca4acd44fca487c4432e6)
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_WANTS_THP_SWAP		if X86_64
104	select BUILDTIME_TABLE_SORT
105	select CLKEVT_I8253
106	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107	select CLOCKSOURCE_WATCHDOG
108	select DCACHE_WORD_ACCESS
109	select EDAC_ATOMIC_SCRUB
110	select EDAC_SUPPORT
111	select GENERIC_CLOCKEVENTS
112	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
113	select GENERIC_CLOCKEVENTS_MIN_ADJUST
114	select GENERIC_CMOS_UPDATE
115	select GENERIC_CPU_AUTOPROBE
116	select GENERIC_CPU_VULNERABILITIES
117	select GENERIC_EARLY_IOREMAP
118	select GENERIC_ENTRY
119	select GENERIC_FIND_FIRST_BIT
120	select GENERIC_IOMAP
121	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
122	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
123	select GENERIC_IRQ_MIGRATION		if SMP
124	select GENERIC_IRQ_PROBE
125	select GENERIC_IRQ_RESERVATION_MODE
126	select GENERIC_IRQ_SHOW
127	select GENERIC_PENDING_IRQ		if SMP
128	select GENERIC_PTDUMP
129	select GENERIC_SMP_IDLE_THREAD
130	select GENERIC_STRNCPY_FROM_USER
131	select GENERIC_STRNLEN_USER
132	select GENERIC_TIME_VSYSCALL
133	select GENERIC_GETTIMEOFDAY
134	select GENERIC_VDSO_TIME_NS
135	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
136	select HARDIRQS_SW_RESEND
137	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
138	select HAVE_ACPI_APEI			if ACPI
139	select HAVE_ACPI_APEI_NMI		if ACPI
140	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
141	select HAVE_ARCH_AUDITSYSCALL
142	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
143	select HAVE_ARCH_JUMP_LABEL
144	select HAVE_ARCH_JUMP_LABEL_RELATIVE
145	select HAVE_ARCH_KASAN			if X86_64
146	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
147	select HAVE_ARCH_KGDB
148	select HAVE_ARCH_MMAP_RND_BITS		if MMU
149	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
150	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
151	select HAVE_ARCH_PREL32_RELOCATIONS
152	select HAVE_ARCH_SECCOMP_FILTER
153	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
154	select HAVE_ARCH_STACKLEAK
155	select HAVE_ARCH_TRACEHOOK
156	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
158	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
159	select HAVE_ARCH_VMAP_STACK		if X86_64
160	select HAVE_ARCH_WITHIN_STACK_FRAMES
161	select HAVE_ASM_MODVERSIONS
162	select HAVE_CMPXCHG_DOUBLE
163	select HAVE_CMPXCHG_LOCAL
164	select HAVE_CONTEXT_TRACKING		if X86_64
165	select HAVE_C_RECORDMCOUNT
166	select HAVE_DEBUG_KMEMLEAK
167	select HAVE_DMA_CONTIGUOUS
168	select HAVE_DYNAMIC_FTRACE
169	select HAVE_DYNAMIC_FTRACE_WITH_REGS
170	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
171	select HAVE_EBPF_JIT
172	select HAVE_EFFICIENT_UNALIGNED_ACCESS
173	select HAVE_EISA
174	select HAVE_EXIT_THREAD
175	select HAVE_FAST_GUP
176	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
177	select HAVE_FTRACE_MCOUNT_RECORD
178	select HAVE_FUNCTION_GRAPH_TRACER
179	select HAVE_FUNCTION_TRACER
180	select HAVE_GCC_PLUGINS
181	select HAVE_HW_BREAKPOINT
182	select HAVE_IDE
183	select HAVE_IOREMAP_PROT
184	select HAVE_IRQ_TIME_ACCOUNTING
185	select HAVE_KERNEL_BZIP2
186	select HAVE_KERNEL_GZIP
187	select HAVE_KERNEL_LZ4
188	select HAVE_KERNEL_LZMA
189	select HAVE_KERNEL_LZO
190	select HAVE_KERNEL_XZ
191	select HAVE_KERNEL_ZSTD
192	select HAVE_KPROBES
193	select HAVE_KPROBES_ON_FTRACE
194	select HAVE_FUNCTION_ERROR_INJECTION
195	select HAVE_KRETPROBES
196	select HAVE_KVM
197	select HAVE_LIVEPATCH			if X86_64
198	select HAVE_MIXED_BREAKPOINTS_REGS
199	select HAVE_MOD_ARCH_SPECIFIC
200	select HAVE_MOVE_PMD
201	select HAVE_NMI
202	select HAVE_OPROFILE
203	select HAVE_OPTPROBES
204	select HAVE_PCSPKR_PLATFORM
205	select HAVE_PERF_EVENTS
206	select HAVE_PERF_EVENTS_NMI
207	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
208	select HAVE_PCI
209	select HAVE_PERF_REGS
210	select HAVE_PERF_USER_STACK_DUMP
211	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
212	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
213	select HAVE_REGS_AND_STACK_ACCESS_API
214	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
215	select HAVE_FUNCTION_ARG_ACCESS_API
216	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
217	select HAVE_STACK_VALIDATION		if X86_64
218	select HAVE_STATIC_CALL
219	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
220	select HAVE_RSEQ
221	select HAVE_SYSCALL_TRACEPOINTS
222	select HAVE_UNSTABLE_SCHED_CLOCK
223	select HAVE_USER_RETURN_NOTIFIER
224	select HAVE_GENERIC_VDSO
225	select HOTPLUG_SMT			if SMP
226	select IRQ_FORCED_THREADING
227	select NEED_SG_DMA_LENGTH
228	select PCI_DOMAINS			if PCI
229	select PCI_LOCKLESS_CONFIG		if PCI
230	select PERF_EVENTS
231	select RTC_LIB
232	select RTC_MC146818_LIB
233	select SPARSE_IRQ
234	select SRCU
235	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
236	select SYSCTL_EXCEPTION_TRACE
237	select THREAD_INFO_IN_TASK
238	select USER_STACKTRACE_SUPPORT
239	select VIRT_TO_BUS
240	select HAVE_ARCH_KCSAN			if X86_64
241	select X86_FEATURE_NAMES		if PROC_FS
242	select PROC_PID_ARCH_STATUS		if PROC_FS
243	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
244
245config INSTRUCTION_DECODER
246	def_bool y
247	depends on KPROBES || PERF_EVENTS || UPROBES
248
249config OUTPUT_FORMAT
250	string
251	default "elf32-i386" if X86_32
252	default "elf64-x86-64" if X86_64
253
254config LOCKDEP_SUPPORT
255	def_bool y
256
257config STACKTRACE_SUPPORT
258	def_bool y
259
260config MMU
261	def_bool y
262
263config ARCH_MMAP_RND_BITS_MIN
264	default 28 if 64BIT
265	default 8
266
267config ARCH_MMAP_RND_BITS_MAX
268	default 32 if 64BIT
269	default 16
270
271config ARCH_MMAP_RND_COMPAT_BITS_MIN
272	default 8
273
274config ARCH_MMAP_RND_COMPAT_BITS_MAX
275	default 16
276
277config SBUS
278	bool
279
280config GENERIC_ISA_DMA
281	def_bool y
282	depends on ISA_DMA_API
283
284config GENERIC_BUG
285	def_bool y
286	depends on BUG
287	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
288
289config GENERIC_BUG_RELATIVE_POINTERS
290	bool
291
292config ARCH_MAY_HAVE_PC_FDC
293	def_bool y
294	depends on ISA_DMA_API
295
296config GENERIC_CALIBRATE_DELAY
297	def_bool y
298
299config ARCH_HAS_CPU_RELAX
300	def_bool y
301
302config ARCH_HAS_CACHE_LINE_SIZE
303	def_bool y
304
305config ARCH_HAS_FILTER_PGPROT
306	def_bool y
307
308config HAVE_SETUP_PER_CPU_AREA
309	def_bool y
310
311config NEED_PER_CPU_EMBED_FIRST_CHUNK
312	def_bool y
313
314config NEED_PER_CPU_PAGE_FIRST_CHUNK
315	def_bool y
316
317config ARCH_HIBERNATION_POSSIBLE
318	def_bool y
319
320config ARCH_SUSPEND_POSSIBLE
321	def_bool y
322
323config ARCH_WANT_GENERAL_HUGETLB
324	def_bool y
325
326config ZONE_DMA32
327	def_bool y if X86_64
328
329config AUDIT_ARCH
330	def_bool y if X86_64
331
332config ARCH_SUPPORTS_DEBUG_PAGEALLOC
333	def_bool y
334
335config KASAN_SHADOW_OFFSET
336	hex
337	depends on KASAN
338	default 0xdffffc0000000000
339
340config HAVE_INTEL_TXT
341	def_bool y
342	depends on INTEL_IOMMU && ACPI
343
344config X86_32_SMP
345	def_bool y
346	depends on X86_32 && SMP
347
348config X86_64_SMP
349	def_bool y
350	depends on X86_64 && SMP
351
352config X86_32_LAZY_GS
353	def_bool y
354	depends on X86_32 && !STACKPROTECTOR
355
356config ARCH_SUPPORTS_UPROBES
357	def_bool y
358
359config FIX_EARLYCON_MEM
360	def_bool y
361
362config DYNAMIC_PHYSICAL_MASK
363	bool
364
365config PGTABLE_LEVELS
366	int
367	default 5 if X86_5LEVEL
368	default 4 if X86_64
369	default 3 if X86_PAE
370	default 2
371
372config CC_HAS_SANE_STACKPROTECTOR
373	bool
374	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
375	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
376	help
377	   We have to make sure stack protector is unconditionally disabled if
378	   the compiler produces broken code.
379
380menu "Processor type and features"
381
382config ZONE_DMA
383	bool "DMA memory allocation support" if EXPERT
384	default y
385	help
386	  DMA memory allocation support allows devices with less than 32-bit
387	  addressing to allocate within the first 16MB of address space.
388	  Disable if no such devices will be used.
389
390	  If unsure, say Y.
391
392config SMP
393	bool "Symmetric multi-processing support"
394	help
395	  This enables support for systems with more than one CPU. If you have
396	  a system with only one CPU, say N. If you have a system with more
397	  than one CPU, say Y.
398
399	  If you say N here, the kernel will run on uni- and multiprocessor
400	  machines, but will use only one CPU of a multiprocessor machine. If
401	  you say Y here, the kernel will run on many, but not all,
402	  uniprocessor machines. On a uniprocessor machine, the kernel
403	  will run faster if you say N here.
404
405	  Note that if you say Y here and choose architecture "586" or
406	  "Pentium" under "Processor family", the kernel will not work on 486
407	  architectures. Similarly, multiprocessor kernels for the "PPro"
408	  architecture may not work on all Pentium based boards.
409
410	  People using multiprocessor machines who say Y here should also say
411	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
412	  Management" code will be disabled if you say Y here.
413
414	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
415	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
416	  <http://www.tldp.org/docs.html#howto>.
417
418	  If you don't know what to do here, say N.
419
420config X86_FEATURE_NAMES
421	bool "Processor feature human-readable names" if EMBEDDED
422	default y
423	help
424	  This option compiles in a table of x86 feature bits and corresponding
425	  names.  This is required to support /proc/cpuinfo and a few kernel
426	  messages.  You can disable this to save space, at the expense of
427	  making those few kernel messages show numeric feature bits instead.
428
429	  If in doubt, say Y.
430
431config X86_X2APIC
432	bool "Support x2apic"
433	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
434	help
435	  This enables x2apic support on CPUs that have this feature.
436
437	  This allows 32-bit apic IDs (so it can support very large systems),
438	  and accesses the local apic via MSRs not via mmio.
439
440	  If you don't know what to do here, say N.
441
442config X86_MPPARSE
443	bool "Enable MPS table" if ACPI || SFI
444	default y
445	depends on X86_LOCAL_APIC
446	help
447	  For old smp systems that do not have proper acpi support. Newer systems
448	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
449
450config GOLDFISH
451	def_bool y
452	depends on X86_GOLDFISH
453
454config RETPOLINE
455	bool "Avoid speculative indirect branches in kernel"
456	default y
457	help
458	  Compile kernel with the retpoline compiler options to guard against
459	  kernel-to-user data leaks by avoiding speculative indirect
460	  branches. Requires a compiler with -mindirect-branch=thunk-extern
461	  support for full protection. The kernel may run slower.
462
463config X86_CPU_RESCTRL
464	bool "x86 CPU resource control support"
465	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
466	select KERNFS
467	select PROC_CPU_RESCTRL		if PROC_FS
468	help
469	  Enable x86 CPU resource control support.
470
471	  Provide support for the allocation and monitoring of system resources
472	  usage by the CPU.
473
474	  Intel calls this Intel Resource Director Technology
475	  (Intel(R) RDT). More information about RDT can be found in the
476	  Intel x86 Architecture Software Developer Manual.
477
478	  AMD calls this AMD Platform Quality of Service (AMD QoS).
479	  More information about AMD QoS can be found in the AMD64 Technology
480	  Platform Quality of Service Extensions manual.
481
482	  Say N if unsure.
483
484if X86_32
485config X86_BIGSMP
486	bool "Support for big SMP systems with more than 8 CPUs"
487	depends on SMP
488	help
489	  This option is needed for the systems that have more than 8 CPUs.
490
491config X86_EXTENDED_PLATFORM
492	bool "Support for extended (non-PC) x86 platforms"
493	default y
494	help
495	  If you disable this option then the kernel will only support
496	  standard PC platforms. (which covers the vast majority of
497	  systems out there.)
498
499	  If you enable this option then you'll be able to select support
500	  for the following (non-PC) 32 bit x86 platforms:
501		Goldfish (Android emulator)
502		AMD Elan
503		RDC R-321x SoC
504		SGI 320/540 (Visual Workstation)
505		STA2X11-based (e.g. Northville)
506		Moorestown MID devices
507
508	  If you have one of these systems, or if you want to build a
509	  generic distribution kernel, say Y here - otherwise say N.
510endif
511
512if X86_64
513config X86_EXTENDED_PLATFORM
514	bool "Support for extended (non-PC) x86 platforms"
515	default y
516	help
517	  If you disable this option then the kernel will only support
518	  standard PC platforms. (which covers the vast majority of
519	  systems out there.)
520
521	  If you enable this option then you'll be able to select support
522	  for the following (non-PC) 64 bit x86 platforms:
523		Numascale NumaChip
524		ScaleMP vSMP
525		SGI Ultraviolet
526
527	  If you have one of these systems, or if you want to build a
528	  generic distribution kernel, say Y here - otherwise say N.
529endif
530# This is an alphabetically sorted list of 64 bit extended platforms
531# Please maintain the alphabetic order if and when there are additions
532config X86_NUMACHIP
533	bool "Numascale NumaChip"
534	depends on X86_64
535	depends on X86_EXTENDED_PLATFORM
536	depends on NUMA
537	depends on SMP
538	depends on X86_X2APIC
539	depends on PCI_MMCONFIG
540	help
541	  Adds support for Numascale NumaChip large-SMP systems. Needed to
542	  enable more than ~168 cores.
543	  If you don't have one of these, you should say N here.
544
545config X86_VSMP
546	bool "ScaleMP vSMP"
547	select HYPERVISOR_GUEST
548	select PARAVIRT
549	depends on X86_64 && PCI
550	depends on X86_EXTENDED_PLATFORM
551	depends on SMP
552	help
553	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
554	  supposed to run on these EM64T-based machines.  Only choose this option
555	  if you have one of these machines.
556
557config X86_UV
558	bool "SGI Ultraviolet"
559	depends on X86_64
560	depends on X86_EXTENDED_PLATFORM
561	depends on NUMA
562	depends on EFI
563	depends on X86_X2APIC
564	depends on PCI
565	help
566	  This option is needed in order to support SGI Ultraviolet systems.
567	  If you don't have one of these, you should say N here.
568
569# Following is an alphabetically sorted list of 32 bit extended platforms
570# Please maintain the alphabetic order if and when there are additions
571
572config X86_GOLDFISH
573	bool "Goldfish (Virtual Platform)"
574	depends on X86_EXTENDED_PLATFORM
575	help
576	 Enable support for the Goldfish virtual platform used primarily
577	 for Android development. Unless you are building for the Android
578	 Goldfish emulator say N here.
579
580config X86_INTEL_CE
581	bool "CE4100 TV platform"
582	depends on PCI
583	depends on PCI_GODIRECT
584	depends on X86_IO_APIC
585	depends on X86_32
586	depends on X86_EXTENDED_PLATFORM
587	select X86_REBOOTFIXUPS
588	select OF
589	select OF_EARLY_FLATTREE
590	help
591	  Select for the Intel CE media processor (CE4100) SOC.
592	  This option compiles in support for the CE4100 SOC for settop
593	  boxes and media devices.
594
595config X86_INTEL_MID
596	bool "Intel MID platform support"
597	depends on X86_EXTENDED_PLATFORM
598	depends on X86_PLATFORM_DEVICES
599	depends on PCI
600	depends on X86_64 || (PCI_GOANY && X86_32)
601	depends on X86_IO_APIC
602	select SFI
603	select I2C
604	select DW_APB_TIMER
605	select APB_TIMER
606	select INTEL_SCU_PCI
607	select MFD_INTEL_MSIC
608	help
609	  Select to build a kernel capable of supporting Intel MID (Mobile
610	  Internet Device) platform systems which do not have the PCI legacy
611	  interfaces. If you are building for a PC class system say N here.
612
613	  Intel MID platforms are based on an Intel processor and chipset which
614	  consume less power than most of the x86 derivatives.
615
616config X86_INTEL_QUARK
617	bool "Intel Quark platform support"
618	depends on X86_32
619	depends on X86_EXTENDED_PLATFORM
620	depends on X86_PLATFORM_DEVICES
621	depends on X86_TSC
622	depends on PCI
623	depends on PCI_GOANY
624	depends on X86_IO_APIC
625	select IOSF_MBI
626	select INTEL_IMR
627	select COMMON_CLK
628	help
629	  Select to include support for Quark X1000 SoC.
630	  Say Y here if you have a Quark based system such as the Arduino
631	  compatible Intel Galileo.
632
633config X86_INTEL_LPSS
634	bool "Intel Low Power Subsystem Support"
635	depends on X86 && ACPI && PCI
636	select COMMON_CLK
637	select PINCTRL
638	select IOSF_MBI
639	help
640	  Select to build support for Intel Low Power Subsystem such as
641	  found on Intel Lynxpoint PCH. Selecting this option enables
642	  things like clock tree (common clock framework) and pincontrol
643	  which are needed by the LPSS peripheral drivers.
644
645config X86_AMD_PLATFORM_DEVICE
646	bool "AMD ACPI2Platform devices support"
647	depends on ACPI
648	select COMMON_CLK
649	select PINCTRL
650	help
651	  Select to interpret AMD specific ACPI device to platform device
652	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
653	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
654	  implemented under PINCTRL subsystem.
655
656config IOSF_MBI
657	tristate "Intel SoC IOSF Sideband support for SoC platforms"
658	depends on PCI
659	help
660	  This option enables sideband register access support for Intel SoC
661	  platforms. On these platforms the IOSF sideband is used in lieu of
662	  MSR's for some register accesses, mostly but not limited to thermal
663	  and power. Drivers may query the availability of this device to
664	  determine if they need the sideband in order to work on these
665	  platforms. The sideband is available on the following SoC products.
666	  This list is not meant to be exclusive.
667	   - BayTrail
668	   - Braswell
669	   - Quark
670
671	  You should say Y if you are running a kernel on one of these SoC's.
672
673config IOSF_MBI_DEBUG
674	bool "Enable IOSF sideband access through debugfs"
675	depends on IOSF_MBI && DEBUG_FS
676	help
677	  Select this option to expose the IOSF sideband access registers (MCR,
678	  MDR, MCRX) through debugfs to write and read register information from
679	  different units on the SoC. This is most useful for obtaining device
680	  state information for debug and analysis. As this is a general access
681	  mechanism, users of this option would have specific knowledge of the
682	  device they want to access.
683
684	  If you don't require the option or are in doubt, say N.
685
686config X86_RDC321X
687	bool "RDC R-321x SoC"
688	depends on X86_32
689	depends on X86_EXTENDED_PLATFORM
690	select M486
691	select X86_REBOOTFIXUPS
692	help
693	  This option is needed for RDC R-321x system-on-chip, also known
694	  as R-8610-(G).
695	  If you don't have one of these chips, you should say N here.
696
697config X86_32_NON_STANDARD
698	bool "Support non-standard 32-bit SMP architectures"
699	depends on X86_32 && SMP
700	depends on X86_EXTENDED_PLATFORM
701	help
702	  This option compiles in the bigsmp and STA2X11 default
703	  subarchitectures.  It is intended for a generic binary
704	  kernel. If you select them all, kernel will probe it one by
705	  one and will fallback to default.
706
707# Alphabetically sorted list of Non standard 32 bit platforms
708
709config X86_SUPPORTS_MEMORY_FAILURE
710	def_bool y
711	# MCE code calls memory_failure():
712	depends on X86_MCE
713	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
714	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
715	depends on X86_64 || !SPARSEMEM
716	select ARCH_SUPPORTS_MEMORY_FAILURE
717
718config STA2X11
719	bool "STA2X11 Companion Chip Support"
720	depends on X86_32_NON_STANDARD && PCI
721	select SWIOTLB
722	select MFD_STA2X11
723	select GPIOLIB
724	help
725	  This adds support for boards based on the STA2X11 IO-Hub,
726	  a.k.a. "ConneXt". The chip is used in place of the standard
727	  PC chipset, so all "standard" peripherals are missing. If this
728	  option is selected the kernel will still be able to boot on
729	  standard PC machines.
730
731config X86_32_IRIS
732	tristate "Eurobraille/Iris poweroff module"
733	depends on X86_32
734	help
735	  The Iris machines from EuroBraille do not have APM or ACPI support
736	  to shut themselves down properly.  A special I/O sequence is
737	  needed to do so, which is what this module does at
738	  kernel shutdown.
739
740	  This is only for Iris machines from EuroBraille.
741
742	  If unused, say N.
743
744config SCHED_OMIT_FRAME_POINTER
745	def_bool y
746	prompt "Single-depth WCHAN output"
747	depends on X86
748	help
749	  Calculate simpler /proc/<PID>/wchan values. If this option
750	  is disabled then wchan values will recurse back to the
751	  caller function. This provides more accurate wchan values,
752	  at the expense of slightly more scheduling overhead.
753
754	  If in doubt, say "Y".
755
756menuconfig HYPERVISOR_GUEST
757	bool "Linux guest support"
758	help
759	  Say Y here to enable options for running Linux under various hyper-
760	  visors. This option enables basic hypervisor detection and platform
761	  setup.
762
763	  If you say N, all options in this submenu will be skipped and
764	  disabled, and Linux guest support won't be built in.
765
766if HYPERVISOR_GUEST
767
768config PARAVIRT
769	bool "Enable paravirtualization code"
770	help
771	  This changes the kernel so it can modify itself when it is run
772	  under a hypervisor, potentially improving performance significantly
773	  over full virtualization.  However, when run without a hypervisor
774	  the kernel is theoretically slower and slightly larger.
775
776config PARAVIRT_XXL
777	bool
778
779config PARAVIRT_DEBUG
780	bool "paravirt-ops debugging"
781	depends on PARAVIRT && DEBUG_KERNEL
782	help
783	  Enable to debug paravirt_ops internals.  Specifically, BUG if
784	  a paravirt_op is missing when it is called.
785
786config PARAVIRT_SPINLOCKS
787	bool "Paravirtualization layer for spinlocks"
788	depends on PARAVIRT && SMP
789	help
790	  Paravirtualized spinlocks allow a pvops backend to replace the
791	  spinlock implementation with something virtualization-friendly
792	  (for example, block the virtual CPU rather than spinning).
793
794	  It has a minimal impact on native kernels and gives a nice performance
795	  benefit on paravirtualized KVM / Xen kernels.
796
797	  If you are unsure how to answer this question, answer Y.
798
799config X86_HV_CALLBACK_VECTOR
800	def_bool n
801
802source "arch/x86/xen/Kconfig"
803
804config KVM_GUEST
805	bool "KVM Guest support (including kvmclock)"
806	depends on PARAVIRT
807	select PARAVIRT_CLOCK
808	select ARCH_CPUIDLE_HALTPOLL
809	select X86_HV_CALLBACK_VECTOR
810	default y
811	help
812	  This option enables various optimizations for running under the KVM
813	  hypervisor. It includes a paravirtualized clock, so that instead
814	  of relying on a PIT (or probably other) emulation by the
815	  underlying device model, the host provides the guest with
816	  timing infrastructure such as time of day, and system time
817
818config ARCH_CPUIDLE_HALTPOLL
819	def_bool n
820	prompt "Disable host haltpoll when loading haltpoll driver"
821	help
822	  If virtualized under KVM, disable host haltpoll.
823
824config PVH
825	bool "Support for running PVH guests"
826	help
827	  This option enables the PVH entry point for guest virtual machines
828	  as specified in the x86/HVM direct boot ABI.
829
830config PARAVIRT_TIME_ACCOUNTING
831	bool "Paravirtual steal time accounting"
832	depends on PARAVIRT
833	help
834	  Select this option to enable fine granularity task steal time
835	  accounting. Time spent executing other tasks in parallel with
836	  the current vCPU is discounted from the vCPU power. To account for
837	  that, there can be a small performance impact.
838
839	  If in doubt, say N here.
840
841config PARAVIRT_CLOCK
842	bool
843
844config JAILHOUSE_GUEST
845	bool "Jailhouse non-root cell support"
846	depends on X86_64 && PCI
847	select X86_PM_TIMER
848	help
849	  This option allows to run Linux as guest in a Jailhouse non-root
850	  cell. You can leave this option disabled if you only want to start
851	  Jailhouse and run Linux afterwards in the root cell.
852
853config ACRN_GUEST
854	bool "ACRN Guest support"
855	depends on X86_64
856	select X86_HV_CALLBACK_VECTOR
857	help
858	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
859	  a flexible, lightweight reference open-source hypervisor, built with
860	  real-time and safety-criticality in mind. It is built for embedded
861	  IOT with small footprint and real-time features. More details can be
862	  found in https://projectacrn.org/.
863
864endif #HYPERVISOR_GUEST
865
866source "arch/x86/Kconfig.cpu"
867
868config HPET_TIMER
869	def_bool X86_64
870	prompt "HPET Timer Support" if X86_32
871	help
872	  Use the IA-PC HPET (High Precision Event Timer) to manage
873	  time in preference to the PIT and RTC, if a HPET is
874	  present.
875	  HPET is the next generation timer replacing legacy 8254s.
876	  The HPET provides a stable time base on SMP
877	  systems, unlike the TSC, but it is more expensive to access,
878	  as it is off-chip.  The interface used is documented
879	  in the HPET spec, revision 1.
880
881	  You can safely choose Y here.  However, HPET will only be
882	  activated if the platform and the BIOS support this feature.
883	  Otherwise the 8254 will be used for timing services.
884
885	  Choose N to continue using the legacy 8254 timer.
886
887config HPET_EMULATE_RTC
888	def_bool y
889	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
890
891config APB_TIMER
892	def_bool y if X86_INTEL_MID
893	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
894	select DW_APB_TIMER
895	depends on X86_INTEL_MID && SFI
896	help
897	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
898	 The APBT provides a stable time base on SMP
899	 systems, unlike the TSC, but it is more expensive to access,
900	 as it is off-chip. APB timers are always running regardless of CPU
901	 C states, they are used as per CPU clockevent device when possible.
902
903# Mark as expert because too many people got it wrong.
904# The code disables itself when not needed.
905config DMI
906	default y
907	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
908	bool "Enable DMI scanning" if EXPERT
909	help
910	  Enabled scanning of DMI to identify machine quirks. Say Y
911	  here unless you have verified that your setup is not
912	  affected by entries in the DMI blacklist. Required by PNP
913	  BIOS code.
914
915config GART_IOMMU
916	bool "Old AMD GART IOMMU support"
917	select DMA_OPS
918	select IOMMU_HELPER
919	select SWIOTLB
920	depends on X86_64 && PCI && AMD_NB
921	help
922	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
923	  GART based hardware IOMMUs.
924
925	  The GART supports full DMA access for devices with 32-bit access
926	  limitations, on systems with more than 3 GB. This is usually needed
927	  for USB, sound, many IDE/SATA chipsets and some other devices.
928
929	  Newer systems typically have a modern AMD IOMMU, supported via
930	  the CONFIG_AMD_IOMMU=y config option.
931
932	  In normal configurations this driver is only active when needed:
933	  there's more than 3 GB of memory and the system contains a
934	  32-bit limited device.
935
936	  If unsure, say Y.
937
938config MAXSMP
939	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
940	depends on X86_64 && SMP && DEBUG_KERNEL
941	select CPUMASK_OFFSTACK
942	help
943	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
944	  If unsure, say N.
945
946#
947# The maximum number of CPUs supported:
948#
949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
950# and which can be configured interactively in the
951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
952#
953# The ranges are different on 32-bit and 64-bit kernels, depending on
954# hardware capabilities and scalability features of the kernel.
955#
956# ( If MAXSMP is enabled we just use the highest possible value and disable
957#   interactive configuration. )
958#
959
960config NR_CPUS_RANGE_BEGIN
961	int
962	default NR_CPUS_RANGE_END if MAXSMP
963	default    1 if !SMP
964	default    2
965
966config NR_CPUS_RANGE_END
967	int
968	depends on X86_32
969	default   64 if  SMP &&  X86_BIGSMP
970	default    8 if  SMP && !X86_BIGSMP
971	default    1 if !SMP
972
973config NR_CPUS_RANGE_END
974	int
975	depends on X86_64
976	default 8192 if  SMP && CPUMASK_OFFSTACK
977	default  512 if  SMP && !CPUMASK_OFFSTACK
978	default    1 if !SMP
979
980config NR_CPUS_DEFAULT
981	int
982	depends on X86_32
983	default   32 if  X86_BIGSMP
984	default    8 if  SMP
985	default    1 if !SMP
986
987config NR_CPUS_DEFAULT
988	int
989	depends on X86_64
990	default 8192 if  MAXSMP
991	default   64 if  SMP
992	default    1 if !SMP
993
994config NR_CPUS
995	int "Maximum number of CPUs" if SMP && !MAXSMP
996	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
997	default NR_CPUS_DEFAULT
998	help
999	  This allows you to specify the maximum number of CPUs which this
1000	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1001	  supported value is 8192, otherwise the maximum value is 512.  The
1002	  minimum value which makes sense is 2.
1003
1004	  This is purely to save memory: each supported CPU adds about 8KB
1005	  to the kernel image.
1006
1007config SCHED_SMT
1008	def_bool y if SMP
1009
1010config SCHED_MC
1011	def_bool y
1012	prompt "Multi-core scheduler support"
1013	depends on SMP
1014	help
1015	  Multi-core scheduler support improves the CPU scheduler's decision
1016	  making when dealing with multi-core CPU chips at a cost of slightly
1017	  increased overhead in some places. If unsure say N here.
1018
1019config SCHED_MC_PRIO
1020	bool "CPU core priorities scheduler support"
1021	depends on SCHED_MC && CPU_SUP_INTEL
1022	select X86_INTEL_PSTATE
1023	select CPU_FREQ
1024	default y
1025	help
1026	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1027	  core ordering determined at manufacturing time, which allows
1028	  certain cores to reach higher turbo frequencies (when running
1029	  single threaded workloads) than others.
1030
1031	  Enabling this kernel feature teaches the scheduler about
1032	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1033	  scheduler's CPU selection logic accordingly, so that higher
1034	  overall system performance can be achieved.
1035
1036	  This feature will have no effect on CPUs without this feature.
1037
1038	  If unsure say Y here.
1039
1040config UP_LATE_INIT
1041	def_bool y
1042	depends on !SMP && X86_LOCAL_APIC
1043
1044config X86_UP_APIC
1045	bool "Local APIC support on uniprocessors" if !PCI_MSI
1046	default PCI_MSI
1047	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1048	help
1049	  A local APIC (Advanced Programmable Interrupt Controller) is an
1050	  integrated interrupt controller in the CPU. If you have a single-CPU
1051	  system which has a processor with a local APIC, you can say Y here to
1052	  enable and use it. If you say Y here even though your machine doesn't
1053	  have a local APIC, then the kernel will still run with no slowdown at
1054	  all. The local APIC supports CPU-generated self-interrupts (timer,
1055	  performance counters), and the NMI watchdog which detects hard
1056	  lockups.
1057
1058config X86_UP_IOAPIC
1059	bool "IO-APIC support on uniprocessors"
1060	depends on X86_UP_APIC
1061	help
1062	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1063	  SMP-capable replacement for PC-style interrupt controllers. Most
1064	  SMP systems and many recent uniprocessor systems have one.
1065
1066	  If you have a single-CPU system with an IO-APIC, you can say Y here
1067	  to use it. If you say Y here even though your machine doesn't have
1068	  an IO-APIC, then the kernel will still run with no slowdown at all.
1069
1070config X86_LOCAL_APIC
1071	def_bool y
1072	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1073	select IRQ_DOMAIN_HIERARCHY
1074	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1075
1076config X86_IO_APIC
1077	def_bool y
1078	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1079
1080config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1081	bool "Reroute for broken boot IRQs"
1082	depends on X86_IO_APIC
1083	help
1084	  This option enables a workaround that fixes a source of
1085	  spurious interrupts. This is recommended when threaded
1086	  interrupt handling is used on systems where the generation of
1087	  superfluous "boot interrupts" cannot be disabled.
1088
1089	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1090	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1091	  kernel does during interrupt handling). On chipsets where this
1092	  boot IRQ generation cannot be disabled, this workaround keeps
1093	  the original IRQ line masked so that only the equivalent "boot
1094	  IRQ" is delivered to the CPUs. The workaround also tells the
1095	  kernel to set up the IRQ handler on the boot IRQ line. In this
1096	  way only one interrupt is delivered to the kernel. Otherwise
1097	  the spurious second interrupt may cause the kernel to bring
1098	  down (vital) interrupt lines.
1099
1100	  Only affects "broken" chipsets. Interrupt sharing may be
1101	  increased on these systems.
1102
1103config X86_MCE
1104	bool "Machine Check / overheating reporting"
1105	select GENERIC_ALLOCATOR
1106	default y
1107	help
1108	  Machine Check support allows the processor to notify the
1109	  kernel if it detects a problem (e.g. overheating, data corruption).
1110	  The action the kernel takes depends on the severity of the problem,
1111	  ranging from warning messages to halting the machine.
1112
1113config X86_MCELOG_LEGACY
1114	bool "Support for deprecated /dev/mcelog character device"
1115	depends on X86_MCE
1116	help
1117	  Enable support for /dev/mcelog which is needed by the old mcelog
1118	  userspace logging daemon. Consider switching to the new generation
1119	  rasdaemon solution.
1120
1121config X86_MCE_INTEL
1122	def_bool y
1123	prompt "Intel MCE features"
1124	depends on X86_MCE && X86_LOCAL_APIC
1125	help
1126	   Additional support for intel specific MCE features such as
1127	   the thermal monitor.
1128
1129config X86_MCE_AMD
1130	def_bool y
1131	prompt "AMD MCE features"
1132	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1133	help
1134	   Additional support for AMD specific MCE features such as
1135	   the DRAM Error Threshold.
1136
1137config X86_ANCIENT_MCE
1138	bool "Support for old Pentium 5 / WinChip machine checks"
1139	depends on X86_32 && X86_MCE
1140	help
1141	  Include support for machine check handling on old Pentium 5 or WinChip
1142	  systems. These typically need to be enabled explicitly on the command
1143	  line.
1144
1145config X86_MCE_THRESHOLD
1146	depends on X86_MCE_AMD || X86_MCE_INTEL
1147	def_bool y
1148
1149config X86_MCE_INJECT
1150	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1151	tristate "Machine check injector support"
1152	help
1153	  Provide support for injecting machine checks for testing purposes.
1154	  If you don't know what a machine check is and you don't do kernel
1155	  QA it is safe to say n.
1156
1157config X86_THERMAL_VECTOR
1158	def_bool y
1159	depends on X86_MCE_INTEL
1160
1161source "arch/x86/events/Kconfig"
1162
1163config X86_LEGACY_VM86
1164	bool "Legacy VM86 support"
1165	depends on X86_32
1166	help
1167	  This option allows user programs to put the CPU into V8086
1168	  mode, which is an 80286-era approximation of 16-bit real mode.
1169
1170	  Some very old versions of X and/or vbetool require this option
1171	  for user mode setting.  Similarly, DOSEMU will use it if
1172	  available to accelerate real mode DOS programs.  However, any
1173	  recent version of DOSEMU, X, or vbetool should be fully
1174	  functional even without kernel VM86 support, as they will all
1175	  fall back to software emulation. Nevertheless, if you are using
1176	  a 16-bit DOS program where 16-bit performance matters, vm86
1177	  mode might be faster than emulation and you might want to
1178	  enable this option.
1179
1180	  Note that any app that works on a 64-bit kernel is unlikely to
1181	  need this option, as 64-bit kernels don't, and can't, support
1182	  V8086 mode. This option is also unrelated to 16-bit protected
1183	  mode and is not needed to run most 16-bit programs under Wine.
1184
1185	  Enabling this option increases the complexity of the kernel
1186	  and slows down exception handling a tiny bit.
1187
1188	  If unsure, say N here.
1189
1190config VM86
1191	bool
1192	default X86_LEGACY_VM86
1193
1194config X86_16BIT
1195	bool "Enable support for 16-bit segments" if EXPERT
1196	default y
1197	depends on MODIFY_LDT_SYSCALL
1198	help
1199	  This option is required by programs like Wine to run 16-bit
1200	  protected mode legacy code on x86 processors.  Disabling
1201	  this option saves about 300 bytes on i386, or around 6K text
1202	  plus 16K runtime memory on x86-64,
1203
1204config X86_ESPFIX32
1205	def_bool y
1206	depends on X86_16BIT && X86_32
1207
1208config X86_ESPFIX64
1209	def_bool y
1210	depends on X86_16BIT && X86_64
1211
1212config X86_VSYSCALL_EMULATION
1213	bool "Enable vsyscall emulation" if EXPERT
1214	default y
1215	depends on X86_64
1216	help
1217	 This enables emulation of the legacy vsyscall page.  Disabling
1218	 it is roughly equivalent to booting with vsyscall=none, except
1219	 that it will also disable the helpful warning if a program
1220	 tries to use a vsyscall.  With this option set to N, offending
1221	 programs will just segfault, citing addresses of the form
1222	 0xffffffffff600?00.
1223
1224	 This option is required by many programs built before 2013, and
1225	 care should be used even with newer programs if set to N.
1226
1227	 Disabling this option saves about 7K of kernel size and
1228	 possibly 4K of additional runtime pagetable memory.
1229
1230config X86_IOPL_IOPERM
1231	bool "IOPERM and IOPL Emulation"
1232	default y
1233	help
1234	  This enables the ioperm() and iopl() syscalls which are necessary
1235	  for legacy applications.
1236
1237	  Legacy IOPL support is an overbroad mechanism which allows user
1238	  space aside of accessing all 65536 I/O ports also to disable
1239	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1240	  capabilities and permission from potentially active security
1241	  modules.
1242
1243	  The emulation restricts the functionality of the syscall to
1244	  only allowing the full range I/O port access, but prevents the
1245	  ability to disable interrupts from user space which would be
1246	  granted if the hardware IOPL mechanism would be used.
1247
1248config TOSHIBA
1249	tristate "Toshiba Laptop support"
1250	depends on X86_32
1251	help
1252	  This adds a driver to safely access the System Management Mode of
1253	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254	  not work on models with a Phoenix BIOS. The System Management Mode
1255	  is used to set the BIOS and power saving options on Toshiba portables.
1256
1257	  For information on utilities to make use of this driver see the
1258	  Toshiba Linux utilities web site at:
1259	  <http://www.buzzard.org.uk/toshiba/>.
1260
1261	  Say Y if you intend to run this kernel on a Toshiba portable.
1262	  Say N otherwise.
1263
1264config I8K
1265	tristate "Dell i8k legacy laptop support"
1266	select HWMON
1267	select SENSORS_DELL_SMM
1268	help
1269	  This option enables legacy /proc/i8k userspace interface in hwmon
1270	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1271	  temperature and allows controlling fan speeds of Dell laptops via
1272	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1273	  it reports also power and hotkey status. For fan speed control is
1274	  needed userspace package i8kutils.
1275
1276	  Say Y if you intend to run this kernel on old Dell laptops or want to
1277	  use userspace package i8kutils.
1278	  Say N otherwise.
1279
1280config X86_REBOOTFIXUPS
1281	bool "Enable X86 board specific fixups for reboot"
1282	depends on X86_32
1283	help
1284	  This enables chipset and/or board specific fixups to be done
1285	  in order to get reboot to work correctly. This is only needed on
1286	  some combinations of hardware and BIOS. The symptom, for which
1287	  this config is intended, is when reboot ends with a stalled/hung
1288	  system.
1289
1290	  Currently, the only fixup is for the Geode machines using
1291	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1292
1293	  Say Y if you want to enable the fixup. Currently, it's safe to
1294	  enable this option even if you don't need it.
1295	  Say N otherwise.
1296
1297config MICROCODE
1298	bool "CPU microcode loading support"
1299	default y
1300	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1301	help
1302	  If you say Y here, you will be able to update the microcode on
1303	  Intel and AMD processors. The Intel support is for the IA32 family,
1304	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1305	  AMD support is for families 0x10 and later. You will obviously need
1306	  the actual microcode binary data itself which is not shipped with
1307	  the Linux kernel.
1308
1309	  The preferred method to load microcode from a detached initrd is described
1310	  in Documentation/x86/microcode.rst. For that you need to enable
1311	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1312	  initrd for microcode blobs.
1313
1314	  In addition, you can build the microcode into the kernel. For that you
1315	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1316	  config option.
1317
1318config MICROCODE_INTEL
1319	bool "Intel microcode loading support"
1320	depends on MICROCODE
1321	default MICROCODE
1322	help
1323	  This options enables microcode patch loading support for Intel
1324	  processors.
1325
1326	  For the current Intel microcode data package go to
1327	  <https://downloadcenter.intel.com> and search for
1328	  'Linux Processor Microcode Data File'.
1329
1330config MICROCODE_AMD
1331	bool "AMD microcode loading support"
1332	depends on MICROCODE
1333	help
1334	  If you select this option, microcode patch loading support for AMD
1335	  processors will be enabled.
1336
1337config MICROCODE_OLD_INTERFACE
1338	bool "Ancient loading interface (DEPRECATED)"
1339	default n
1340	depends on MICROCODE
1341	help
1342	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1343	  which was used by userspace tools like iucode_tool and microcode.ctl.
1344	  It is inadequate because it runs too late to be able to properly
1345	  load microcode on a machine and it needs special tools. Instead, you
1346	  should've switched to the early loading method with the initrd or
1347	  builtin microcode by now: Documentation/x86/microcode.rst
1348
1349config X86_MSR
1350	tristate "/dev/cpu/*/msr - Model-specific register support"
1351	help
1352	  This device gives privileged processes access to the x86
1353	  Model-Specific Registers (MSRs).  It is a character device with
1354	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1355	  MSR accesses are directed to a specific CPU on multi-processor
1356	  systems.
1357
1358config X86_CPUID
1359	tristate "/dev/cpu/*/cpuid - CPU information support"
1360	help
1361	  This device gives processes access to the x86 CPUID instruction to
1362	  be executed on a specific processor.  It is a character device
1363	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1364	  /dev/cpu/31/cpuid.
1365
1366choice
1367	prompt "High Memory Support"
1368	default HIGHMEM4G
1369	depends on X86_32
1370
1371config NOHIGHMEM
1372	bool "off"
1373	help
1374	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1375	  However, the address space of 32-bit x86 processors is only 4
1376	  Gigabytes large. That means that, if you have a large amount of
1377	  physical memory, not all of it can be "permanently mapped" by the
1378	  kernel. The physical memory that's not permanently mapped is called
1379	  "high memory".
1380
1381	  If you are compiling a kernel which will never run on a machine with
1382	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1383	  choice and suitable for most users). This will result in a "3GB/1GB"
1384	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1385	  space and the remaining part of the 4GB virtual memory space is used
1386	  by the kernel to permanently map as much physical memory as
1387	  possible.
1388
1389	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1390	  answer "4GB" here.
1391
1392	  If more than 4 Gigabytes is used then answer "64GB" here. This
1393	  selection turns Intel PAE (Physical Address Extension) mode on.
1394	  PAE implements 3-level paging on IA32 processors. PAE is fully
1395	  supported by Linux, PAE mode is implemented on all recent Intel
1396	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1397	  then the kernel will not boot on CPUs that don't support PAE!
1398
1399	  The actual amount of total physical memory will either be
1400	  auto detected or can be forced by using a kernel command line option
1401	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1402	  your boot loader (lilo or loadlin) about how to pass options to the
1403	  kernel at boot time.)
1404
1405	  If unsure, say "off".
1406
1407config HIGHMEM4G
1408	bool "4GB"
1409	help
1410	  Select this if you have a 32-bit processor and between 1 and 4
1411	  gigabytes of physical RAM.
1412
1413config HIGHMEM64G
1414	bool "64GB"
1415	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1416	select X86_PAE
1417	help
1418	  Select this if you have a 32-bit processor and more than 4
1419	  gigabytes of physical RAM.
1420
1421endchoice
1422
1423choice
1424	prompt "Memory split" if EXPERT
1425	default VMSPLIT_3G
1426	depends on X86_32
1427	help
1428	  Select the desired split between kernel and user memory.
1429
1430	  If the address range available to the kernel is less than the
1431	  physical memory installed, the remaining memory will be available
1432	  as "high memory". Accessing high memory is a little more costly
1433	  than low memory, as it needs to be mapped into the kernel first.
1434	  Note that increasing the kernel address space limits the range
1435	  available to user programs, making the address space there
1436	  tighter.  Selecting anything other than the default 3G/1G split
1437	  will also likely make your kernel incompatible with binary-only
1438	  kernel modules.
1439
1440	  If you are not absolutely sure what you are doing, leave this
1441	  option alone!
1442
1443	config VMSPLIT_3G
1444		bool "3G/1G user/kernel split"
1445	config VMSPLIT_3G_OPT
1446		depends on !X86_PAE
1447		bool "3G/1G user/kernel split (for full 1G low memory)"
1448	config VMSPLIT_2G
1449		bool "2G/2G user/kernel split"
1450	config VMSPLIT_2G_OPT
1451		depends on !X86_PAE
1452		bool "2G/2G user/kernel split (for full 2G low memory)"
1453	config VMSPLIT_1G
1454		bool "1G/3G user/kernel split"
1455endchoice
1456
1457config PAGE_OFFSET
1458	hex
1459	default 0xB0000000 if VMSPLIT_3G_OPT
1460	default 0x80000000 if VMSPLIT_2G
1461	default 0x78000000 if VMSPLIT_2G_OPT
1462	default 0x40000000 if VMSPLIT_1G
1463	default 0xC0000000
1464	depends on X86_32
1465
1466config HIGHMEM
1467	def_bool y
1468	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1469
1470config X86_PAE
1471	bool "PAE (Physical Address Extension) Support"
1472	depends on X86_32 && !HIGHMEM4G
1473	select PHYS_ADDR_T_64BIT
1474	select SWIOTLB
1475	help
1476	  PAE is required for NX support, and furthermore enables
1477	  larger swapspace support for non-overcommit purposes. It
1478	  has the cost of more pagetable lookup overhead, and also
1479	  consumes more pagetable space per process.
1480
1481config X86_5LEVEL
1482	bool "Enable 5-level page tables support"
1483	default y
1484	select DYNAMIC_MEMORY_LAYOUT
1485	select SPARSEMEM_VMEMMAP
1486	depends on X86_64
1487	help
1488	  5-level paging enables access to larger address space:
1489	  upto 128 PiB of virtual address space and 4 PiB of
1490	  physical address space.
1491
1492	  It will be supported by future Intel CPUs.
1493
1494	  A kernel with the option enabled can be booted on machines that
1495	  support 4- or 5-level paging.
1496
1497	  See Documentation/x86/x86_64/5level-paging.rst for more
1498	  information.
1499
1500	  Say N if unsure.
1501
1502config X86_DIRECT_GBPAGES
1503	def_bool y
1504	depends on X86_64
1505	help
1506	  Certain kernel features effectively disable kernel
1507	  linear 1 GB mappings (even if the CPU otherwise
1508	  supports them), so don't confuse the user by printing
1509	  that we have them enabled.
1510
1511config X86_CPA_STATISTICS
1512	bool "Enable statistic for Change Page Attribute"
1513	depends on DEBUG_FS
1514	help
1515	  Expose statistics about the Change Page Attribute mechanism, which
1516	  helps to determine the effectiveness of preserving large and huge
1517	  page mappings when mapping protections are changed.
1518
1519config AMD_MEM_ENCRYPT
1520	bool "AMD Secure Memory Encryption (SME) support"
1521	depends on X86_64 && CPU_SUP_AMD
1522	select DMA_COHERENT_POOL
1523	select DYNAMIC_PHYSICAL_MASK
1524	select ARCH_USE_MEMREMAP_PROT
1525	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1526	help
1527	  Say yes to enable support for the encryption of system memory.
1528	  This requires an AMD processor that supports Secure Memory
1529	  Encryption (SME).
1530
1531config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1532	bool "Activate AMD Secure Memory Encryption (SME) by default"
1533	default y
1534	depends on AMD_MEM_ENCRYPT
1535	help
1536	  Say yes to have system memory encrypted by default if running on
1537	  an AMD processor that supports Secure Memory Encryption (SME).
1538
1539	  If set to Y, then the encryption of system memory can be
1540	  deactivated with the mem_encrypt=off command line option.
1541
1542	  If set to N, then the encryption of system memory can be
1543	  activated with the mem_encrypt=on command line option.
1544
1545# Common NUMA Features
1546config NUMA
1547	bool "NUMA Memory Allocation and Scheduler Support"
1548	depends on SMP
1549	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1550	default y if X86_BIGSMP
1551	help
1552	  Enable NUMA (Non-Uniform Memory Access) support.
1553
1554	  The kernel will try to allocate memory used by a CPU on the
1555	  local memory controller of the CPU and add some more
1556	  NUMA awareness to the kernel.
1557
1558	  For 64-bit this is recommended if the system is Intel Core i7
1559	  (or later), AMD Opteron, or EM64T NUMA.
1560
1561	  For 32-bit this is only needed if you boot a 32-bit
1562	  kernel on a 64-bit NUMA platform.
1563
1564	  Otherwise, you should say N.
1565
1566config AMD_NUMA
1567	def_bool y
1568	prompt "Old style AMD Opteron NUMA detection"
1569	depends on X86_64 && NUMA && PCI
1570	help
1571	  Enable AMD NUMA node topology detection.  You should say Y here if
1572	  you have a multi processor AMD system. This uses an old method to
1573	  read the NUMA configuration directly from the builtin Northbridge
1574	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1575	  which also takes priority if both are compiled in.
1576
1577config X86_64_ACPI_NUMA
1578	def_bool y
1579	prompt "ACPI NUMA detection"
1580	depends on X86_64 && NUMA && ACPI && PCI
1581	select ACPI_NUMA
1582	help
1583	  Enable ACPI SRAT based node topology detection.
1584
1585config NUMA_EMU
1586	bool "NUMA emulation"
1587	depends on NUMA
1588	help
1589	  Enable NUMA emulation. A flat machine will be split
1590	  into virtual nodes when booted with "numa=fake=N", where N is the
1591	  number of nodes. This is only useful for debugging.
1592
1593config NODES_SHIFT
1594	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1595	range 1 10
1596	default "10" if MAXSMP
1597	default "6" if X86_64
1598	default "3"
1599	depends on NEED_MULTIPLE_NODES
1600	help
1601	  Specify the maximum number of NUMA Nodes available on the target
1602	  system.  Increases memory reserved to accommodate various tables.
1603
1604config ARCH_FLATMEM_ENABLE
1605	def_bool y
1606	depends on X86_32 && !NUMA
1607
1608config ARCH_SPARSEMEM_ENABLE
1609	def_bool y
1610	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1611	select SPARSEMEM_STATIC if X86_32
1612	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1613
1614config ARCH_SPARSEMEM_DEFAULT
1615	def_bool X86_64 || (NUMA && X86_32)
1616
1617config ARCH_SELECT_MEMORY_MODEL
1618	def_bool y
1619	depends on ARCH_SPARSEMEM_ENABLE
1620
1621config ARCH_MEMORY_PROBE
1622	bool "Enable sysfs memory/probe interface"
1623	depends on X86_64 && MEMORY_HOTPLUG
1624	help
1625	  This option enables a sysfs memory/probe interface for testing.
1626	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1627	  If you are unsure how to answer this question, answer N.
1628
1629config ARCH_PROC_KCORE_TEXT
1630	def_bool y
1631	depends on X86_64 && PROC_KCORE
1632
1633config ILLEGAL_POINTER_VALUE
1634	hex
1635	default 0 if X86_32
1636	default 0xdead000000000000 if X86_64
1637
1638config X86_PMEM_LEGACY_DEVICE
1639	bool
1640
1641config X86_PMEM_LEGACY
1642	tristate "Support non-standard NVDIMMs and ADR protected memory"
1643	depends on PHYS_ADDR_T_64BIT
1644	depends on BLK_DEV
1645	select X86_PMEM_LEGACY_DEVICE
1646	select NUMA_KEEP_MEMINFO if NUMA
1647	select LIBNVDIMM
1648	help
1649	  Treat memory marked using the non-standard e820 type of 12 as used
1650	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1651	  The kernel will offer these regions to the 'pmem' driver so
1652	  they can be used for persistent storage.
1653
1654	  Say Y if unsure.
1655
1656config HIGHPTE
1657	bool "Allocate 3rd-level pagetables from highmem"
1658	depends on HIGHMEM
1659	help
1660	  The VM uses one page table entry for each page of physical memory.
1661	  For systems with a lot of RAM, this can be wasteful of precious
1662	  low memory.  Setting this option will put user-space page table
1663	  entries in high memory.
1664
1665config X86_CHECK_BIOS_CORRUPTION
1666	bool "Check for low memory corruption"
1667	help
1668	  Periodically check for memory corruption in low memory, which
1669	  is suspected to be caused by BIOS.  Even when enabled in the
1670	  configuration, it is disabled at runtime.  Enable it by
1671	  setting "memory_corruption_check=1" on the kernel command
1672	  line.  By default it scans the low 64k of memory every 60
1673	  seconds; see the memory_corruption_check_size and
1674	  memory_corruption_check_period parameters in
1675	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1676
1677	  When enabled with the default parameters, this option has
1678	  almost no overhead, as it reserves a relatively small amount
1679	  of memory and scans it infrequently.  It both detects corruption
1680	  and prevents it from affecting the running system.
1681
1682	  It is, however, intended as a diagnostic tool; if repeatable
1683	  BIOS-originated corruption always affects the same memory,
1684	  you can use memmap= to prevent the kernel from using that
1685	  memory.
1686
1687config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1688	bool "Set the default setting of memory_corruption_check"
1689	depends on X86_CHECK_BIOS_CORRUPTION
1690	default y
1691	help
1692	  Set whether the default state of memory_corruption_check is
1693	  on or off.
1694
1695config X86_RESERVE_LOW
1696	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1697	default 64
1698	range 4 640
1699	help
1700	  Specify the amount of low memory to reserve for the BIOS.
1701
1702	  The first page contains BIOS data structures that the kernel
1703	  must not use, so that page must always be reserved.
1704
1705	  By default we reserve the first 64K of physical RAM, as a
1706	  number of BIOSes are known to corrupt that memory range
1707	  during events such as suspend/resume or monitor cable
1708	  insertion, so it must not be used by the kernel.
1709
1710	  You can set this to 4 if you are absolutely sure that you
1711	  trust the BIOS to get all its memory reservations and usages
1712	  right.  If you know your BIOS have problems beyond the
1713	  default 64K area, you can set this to 640 to avoid using the
1714	  entire low memory range.
1715
1716	  If you have doubts about the BIOS (e.g. suspend/resume does
1717	  not work or there's kernel crashes after certain hardware
1718	  hotplug events) then you might want to enable
1719	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1720	  typical corruption patterns.
1721
1722	  Leave this to the default value of 64 if you are unsure.
1723
1724config MATH_EMULATION
1725	bool
1726	depends on MODIFY_LDT_SYSCALL
1727	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1728	help
1729	  Linux can emulate a math coprocessor (used for floating point
1730	  operations) if you don't have one. 486DX and Pentium processors have
1731	  a math coprocessor built in, 486SX and 386 do not, unless you added
1732	  a 487DX or 387, respectively. (The messages during boot time can
1733	  give you some hints here ["man dmesg"].) Everyone needs either a
1734	  coprocessor or this emulation.
1735
1736	  If you don't have a math coprocessor, you need to say Y here; if you
1737	  say Y here even though you have a coprocessor, the coprocessor will
1738	  be used nevertheless. (This behavior can be changed with the kernel
1739	  command line option "no387", which comes handy if your coprocessor
1740	  is broken. Try "man bootparam" or see the documentation of your boot
1741	  loader (lilo or loadlin) about how to pass options to the kernel at
1742	  boot time.) This means that it is a good idea to say Y here if you
1743	  intend to use this kernel on different machines.
1744
1745	  More information about the internals of the Linux math coprocessor
1746	  emulation can be found in <file:arch/x86/math-emu/README>.
1747
1748	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1749	  kernel, it won't hurt.
1750
1751config MTRR
1752	def_bool y
1753	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1754	help
1755	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1756	  the Memory Type Range Registers (MTRRs) may be used to control
1757	  processor access to memory ranges. This is most useful if you have
1758	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1759	  allows bus write transfers to be combined into a larger transfer
1760	  before bursting over the PCI/AGP bus. This can increase performance
1761	  of image write operations 2.5 times or more. Saying Y here creates a
1762	  /proc/mtrr file which may be used to manipulate your processor's
1763	  MTRRs. Typically the X server should use this.
1764
1765	  This code has a reasonably generic interface so that similar
1766	  control registers on other processors can be easily supported
1767	  as well:
1768
1769	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1770	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1771	  these, the ARRs are used to emulate the MTRRs.
1772	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1773	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1774	  write-combining. All of these processors are supported by this code
1775	  and it makes sense to say Y here if you have one of them.
1776
1777	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1778	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1779	  can lead to all sorts of problems, so it's good to say Y here.
1780
1781	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1782	  just add about 9 KB to your kernel.
1783
1784	  See <file:Documentation/x86/mtrr.rst> for more information.
1785
1786config MTRR_SANITIZER
1787	def_bool y
1788	prompt "MTRR cleanup support"
1789	depends on MTRR
1790	help
1791	  Convert MTRR layout from continuous to discrete, so X drivers can
1792	  add writeback entries.
1793
1794	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1795	  The largest mtrr entry size for a continuous block can be set with
1796	  mtrr_chunk_size.
1797
1798	  If unsure, say Y.
1799
1800config MTRR_SANITIZER_ENABLE_DEFAULT
1801	int "MTRR cleanup enable value (0-1)"
1802	range 0 1
1803	default "0"
1804	depends on MTRR_SANITIZER
1805	help
1806	  Enable mtrr cleanup default value
1807
1808config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1809	int "MTRR cleanup spare reg num (0-7)"
1810	range 0 7
1811	default "1"
1812	depends on MTRR_SANITIZER
1813	help
1814	  mtrr cleanup spare entries default, it can be changed via
1815	  mtrr_spare_reg_nr=N on the kernel command line.
1816
1817config X86_PAT
1818	def_bool y
1819	prompt "x86 PAT support" if EXPERT
1820	depends on MTRR
1821	help
1822	  Use PAT attributes to setup page level cache control.
1823
1824	  PATs are the modern equivalents of MTRRs and are much more
1825	  flexible than MTRRs.
1826
1827	  Say N here if you see bootup problems (boot crash, boot hang,
1828	  spontaneous reboots) or a non-working video driver.
1829
1830	  If unsure, say Y.
1831
1832config ARCH_USES_PG_UNCACHED
1833	def_bool y
1834	depends on X86_PAT
1835
1836config ARCH_RANDOM
1837	def_bool y
1838	prompt "x86 architectural random number generator" if EXPERT
1839	help
1840	  Enable the x86 architectural RDRAND instruction
1841	  (Intel Bull Mountain technology) to generate random numbers.
1842	  If supported, this is a high bandwidth, cryptographically
1843	  secure hardware random number generator.
1844
1845config X86_SMAP
1846	def_bool y
1847	prompt "Supervisor Mode Access Prevention" if EXPERT
1848	help
1849	  Supervisor Mode Access Prevention (SMAP) is a security
1850	  feature in newer Intel processors.  There is a small
1851	  performance cost if this enabled and turned on; there is
1852	  also a small increase in the kernel size if this is enabled.
1853
1854	  If unsure, say Y.
1855
1856config X86_UMIP
1857	def_bool y
1858	prompt "User Mode Instruction Prevention" if EXPERT
1859	help
1860	  User Mode Instruction Prevention (UMIP) is a security feature in
1861	  some x86 processors. If enabled, a general protection fault is
1862	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1863	  executed in user mode. These instructions unnecessarily expose
1864	  information about the hardware state.
1865
1866	  The vast majority of applications do not use these instructions.
1867	  For the very few that do, software emulation is provided in
1868	  specific cases in protected and virtual-8086 modes. Emulated
1869	  results are dummy.
1870
1871config X86_INTEL_MEMORY_PROTECTION_KEYS
1872	prompt "Memory Protection Keys"
1873	def_bool y
1874	# Note: only available in 64-bit mode
1875	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1876	select ARCH_USES_HIGH_VMA_FLAGS
1877	select ARCH_HAS_PKEYS
1878	help
1879	  Memory Protection Keys provides a mechanism for enforcing
1880	  page-based protections, but without requiring modification of the
1881	  page tables when an application changes protection domains.
1882
1883	  For details, see Documentation/core-api/protection-keys.rst
1884
1885	  If unsure, say y.
1886
1887choice
1888	prompt "TSX enable mode"
1889	depends on CPU_SUP_INTEL
1890	default X86_INTEL_TSX_MODE_OFF
1891	help
1892	  Intel's TSX (Transactional Synchronization Extensions) feature
1893	  allows to optimize locking protocols through lock elision which
1894	  can lead to a noticeable performance boost.
1895
1896	  On the other hand it has been shown that TSX can be exploited
1897	  to form side channel attacks (e.g. TAA) and chances are there
1898	  will be more of those attacks discovered in the future.
1899
1900	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1901	  might override this decision by tsx=on the command line parameter.
1902	  Even with TSX enabled, the kernel will attempt to enable the best
1903	  possible TAA mitigation setting depending on the microcode available
1904	  for the particular machine.
1905
1906	  This option allows to set the default tsx mode between tsx=on, =off
1907	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1908	  details.
1909
1910	  Say off if not sure, auto if TSX is in use but it should be used on safe
1911	  platforms or on if TSX is in use and the security aspect of tsx is not
1912	  relevant.
1913
1914config X86_INTEL_TSX_MODE_OFF
1915	bool "off"
1916	help
1917	  TSX is disabled if possible - equals to tsx=off command line parameter.
1918
1919config X86_INTEL_TSX_MODE_ON
1920	bool "on"
1921	help
1922	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1923	  line parameter.
1924
1925config X86_INTEL_TSX_MODE_AUTO
1926	bool "auto"
1927	help
1928	  TSX is enabled on TSX capable HW that is believed to be safe against
1929	  side channel attacks- equals the tsx=auto command line parameter.
1930endchoice
1931
1932config EFI
1933	bool "EFI runtime service support"
1934	depends on ACPI
1935	select UCS2_STRING
1936	select EFI_RUNTIME_WRAPPERS
1937	help
1938	  This enables the kernel to use EFI runtime services that are
1939	  available (such as the EFI variable services).
1940
1941	  This option is only useful on systems that have EFI firmware.
1942	  In addition, you should use the latest ELILO loader available
1943	  at <http://elilo.sourceforge.net> in order to take advantage
1944	  of EFI runtime services. However, even with this option, the
1945	  resultant kernel should continue to boot on existing non-EFI
1946	  platforms.
1947
1948config EFI_STUB
1949	bool "EFI stub support"
1950	depends on EFI && !X86_USE_3DNOW
1951	depends on $(cc-option,-mabi=ms) || X86_32
1952	select RELOCATABLE
1953	help
1954	  This kernel feature allows a bzImage to be loaded directly
1955	  by EFI firmware without the use of a bootloader.
1956
1957	  See Documentation/admin-guide/efi-stub.rst for more information.
1958
1959config EFI_MIXED
1960	bool "EFI mixed-mode support"
1961	depends on EFI_STUB && X86_64
1962	help
1963	   Enabling this feature allows a 64-bit kernel to be booted
1964	   on a 32-bit firmware, provided that your CPU supports 64-bit
1965	   mode.
1966
1967	   Note that it is not possible to boot a mixed-mode enabled
1968	   kernel via the EFI boot stub - a bootloader that supports
1969	   the EFI handover protocol must be used.
1970
1971	   If unsure, say N.
1972
1973config SECCOMP
1974	def_bool y
1975	prompt "Enable seccomp to safely compute untrusted bytecode"
1976	help
1977	  This kernel feature is useful for number crunching applications
1978	  that may need to compute untrusted bytecode during their
1979	  execution. By using pipes or other transports made available to
1980	  the process as file descriptors supporting the read/write
1981	  syscalls, it's possible to isolate those applications in
1982	  their own address space using seccomp. Once seccomp is
1983	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1984	  and the task is only allowed to execute a few safe syscalls
1985	  defined by each seccomp mode.
1986
1987	  If unsure, say Y. Only embedded should say N here.
1988
1989source "kernel/Kconfig.hz"
1990
1991config KEXEC
1992	bool "kexec system call"
1993	select KEXEC_CORE
1994	help
1995	  kexec is a system call that implements the ability to shutdown your
1996	  current kernel, and to start another kernel.  It is like a reboot
1997	  but it is independent of the system firmware.   And like a reboot
1998	  you can start any kernel with it, not just Linux.
1999
2000	  The name comes from the similarity to the exec system call.
2001
2002	  It is an ongoing process to be certain the hardware in a machine
2003	  is properly shutdown, so do not be surprised if this code does not
2004	  initially work for you.  As of this writing the exact hardware
2005	  interface is strongly in flux, so no good recommendation can be
2006	  made.
2007
2008config KEXEC_FILE
2009	bool "kexec file based system call"
2010	select KEXEC_CORE
2011	select BUILD_BIN2C
2012	depends on X86_64
2013	depends on CRYPTO=y
2014	depends on CRYPTO_SHA256=y
2015	help
2016	  This is new version of kexec system call. This system call is
2017	  file based and takes file descriptors as system call argument
2018	  for kernel and initramfs as opposed to list of segments as
2019	  accepted by previous system call.
2020
2021config ARCH_HAS_KEXEC_PURGATORY
2022	def_bool KEXEC_FILE
2023
2024config KEXEC_SIG
2025	bool "Verify kernel signature during kexec_file_load() syscall"
2026	depends on KEXEC_FILE
2027	help
2028
2029	  This option makes the kexec_file_load() syscall check for a valid
2030	  signature of the kernel image.  The image can still be loaded without
2031	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2032	  there's a signature that we can check, then it must be valid.
2033
2034	  In addition to this option, you need to enable signature
2035	  verification for the corresponding kernel image type being
2036	  loaded in order for this to work.
2037
2038config KEXEC_SIG_FORCE
2039	bool "Require a valid signature in kexec_file_load() syscall"
2040	depends on KEXEC_SIG
2041	help
2042	  This option makes kernel signature verification mandatory for
2043	  the kexec_file_load() syscall.
2044
2045config KEXEC_BZIMAGE_VERIFY_SIG
2046	bool "Enable bzImage signature verification support"
2047	depends on KEXEC_SIG
2048	depends on SIGNED_PE_FILE_VERIFICATION
2049	select SYSTEM_TRUSTED_KEYRING
2050	help
2051	  Enable bzImage signature verification support.
2052
2053config CRASH_DUMP
2054	bool "kernel crash dumps"
2055	depends on X86_64 || (X86_32 && HIGHMEM)
2056	help
2057	  Generate crash dump after being started by kexec.
2058	  This should be normally only set in special crash dump kernels
2059	  which are loaded in the main kernel with kexec-tools into
2060	  a specially reserved region and then later executed after
2061	  a crash by kdump/kexec. The crash dump kernel must be compiled
2062	  to a memory address not used by the main kernel or BIOS using
2063	  PHYSICAL_START, or it must be built as a relocatable image
2064	  (CONFIG_RELOCATABLE=y).
2065	  For more details see Documentation/admin-guide/kdump/kdump.rst
2066
2067config KEXEC_JUMP
2068	bool "kexec jump"
2069	depends on KEXEC && HIBERNATION
2070	help
2071	  Jump between original kernel and kexeced kernel and invoke
2072	  code in physical address mode via KEXEC
2073
2074config PHYSICAL_START
2075	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2076	default "0x1000000"
2077	help
2078	  This gives the physical address where the kernel is loaded.
2079
2080	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2081	  bzImage will decompress itself to above physical address and
2082	  run from there. Otherwise, bzImage will run from the address where
2083	  it has been loaded by the boot loader and will ignore above physical
2084	  address.
2085
2086	  In normal kdump cases one does not have to set/change this option
2087	  as now bzImage can be compiled as a completely relocatable image
2088	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2089	  address. This option is mainly useful for the folks who don't want
2090	  to use a bzImage for capturing the crash dump and want to use a
2091	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2092	  to be specifically compiled to run from a specific memory area
2093	  (normally a reserved region) and this option comes handy.
2094
2095	  So if you are using bzImage for capturing the crash dump,
2096	  leave the value here unchanged to 0x1000000 and set
2097	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2098	  for capturing the crash dump change this value to start of
2099	  the reserved region.  In other words, it can be set based on
2100	  the "X" value as specified in the "crashkernel=YM@XM"
2101	  command line boot parameter passed to the panic-ed
2102	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2103	  for more details about crash dumps.
2104
2105	  Usage of bzImage for capturing the crash dump is recommended as
2106	  one does not have to build two kernels. Same kernel can be used
2107	  as production kernel and capture kernel. Above option should have
2108	  gone away after relocatable bzImage support is introduced. But it
2109	  is present because there are users out there who continue to use
2110	  vmlinux for dump capture. This option should go away down the
2111	  line.
2112
2113	  Don't change this unless you know what you are doing.
2114
2115config RELOCATABLE
2116	bool "Build a relocatable kernel"
2117	default y
2118	help
2119	  This builds a kernel image that retains relocation information
2120	  so it can be loaded someplace besides the default 1MB.
2121	  The relocations tend to make the kernel binary about 10% larger,
2122	  but are discarded at runtime.
2123
2124	  One use is for the kexec on panic case where the recovery kernel
2125	  must live at a different physical address than the primary
2126	  kernel.
2127
2128	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2129	  it has been loaded at and the compile time physical address
2130	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2131
2132config RANDOMIZE_BASE
2133	bool "Randomize the address of the kernel image (KASLR)"
2134	depends on RELOCATABLE
2135	default y
2136	help
2137	  In support of Kernel Address Space Layout Randomization (KASLR),
2138	  this randomizes the physical address at which the kernel image
2139	  is decompressed and the virtual address where the kernel
2140	  image is mapped, as a security feature that deters exploit
2141	  attempts relying on knowledge of the location of kernel
2142	  code internals.
2143
2144	  On 64-bit, the kernel physical and virtual addresses are
2145	  randomized separately. The physical address will be anywhere
2146	  between 16MB and the top of physical memory (up to 64TB). The
2147	  virtual address will be randomized from 16MB up to 1GB (9 bits
2148	  of entropy). Note that this also reduces the memory space
2149	  available to kernel modules from 1.5GB to 1GB.
2150
2151	  On 32-bit, the kernel physical and virtual addresses are
2152	  randomized together. They will be randomized from 16MB up to
2153	  512MB (8 bits of entropy).
2154
2155	  Entropy is generated using the RDRAND instruction if it is
2156	  supported. If RDTSC is supported, its value is mixed into
2157	  the entropy pool as well. If neither RDRAND nor RDTSC are
2158	  supported, then entropy is read from the i8254 timer. The
2159	  usable entropy is limited by the kernel being built using
2160	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2161	  minimum of 2MB. As a result, only 10 bits of entropy are
2162	  theoretically possible, but the implementations are further
2163	  limited due to memory layouts.
2164
2165	  If unsure, say Y.
2166
2167# Relocation on x86 needs some additional build support
2168config X86_NEED_RELOCS
2169	def_bool y
2170	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2171
2172config PHYSICAL_ALIGN
2173	hex "Alignment value to which kernel should be aligned"
2174	default "0x200000"
2175	range 0x2000 0x1000000 if X86_32
2176	range 0x200000 0x1000000 if X86_64
2177	help
2178	  This value puts the alignment restrictions on physical address
2179	  where kernel is loaded and run from. Kernel is compiled for an
2180	  address which meets above alignment restriction.
2181
2182	  If bootloader loads the kernel at a non-aligned address and
2183	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2184	  address aligned to above value and run from there.
2185
2186	  If bootloader loads the kernel at a non-aligned address and
2187	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2188	  load address and decompress itself to the address it has been
2189	  compiled for and run from there. The address for which kernel is
2190	  compiled already meets above alignment restrictions. Hence the
2191	  end result is that kernel runs from a physical address meeting
2192	  above alignment restrictions.
2193
2194	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2195	  this value must be a multiple of 0x200000.
2196
2197	  Don't change this unless you know what you are doing.
2198
2199config DYNAMIC_MEMORY_LAYOUT
2200	bool
2201	help
2202	  This option makes base addresses of vmalloc and vmemmap as well as
2203	  __PAGE_OFFSET movable during boot.
2204
2205config RANDOMIZE_MEMORY
2206	bool "Randomize the kernel memory sections"
2207	depends on X86_64
2208	depends on RANDOMIZE_BASE
2209	select DYNAMIC_MEMORY_LAYOUT
2210	default RANDOMIZE_BASE
2211	help
2212	   Randomizes the base virtual address of kernel memory sections
2213	   (physical memory mapping, vmalloc & vmemmap). This security feature
2214	   makes exploits relying on predictable memory locations less reliable.
2215
2216	   The order of allocations remains unchanged. Entropy is generated in
2217	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2218	   configuration have in average 30,000 different possible virtual
2219	   addresses for each memory section.
2220
2221	   If unsure, say Y.
2222
2223config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2224	hex "Physical memory mapping padding" if EXPERT
2225	depends on RANDOMIZE_MEMORY
2226	default "0xa" if MEMORY_HOTPLUG
2227	default "0x0"
2228	range 0x1 0x40 if MEMORY_HOTPLUG
2229	range 0x0 0x40
2230	help
2231	   Define the padding in terabytes added to the existing physical
2232	   memory size during kernel memory randomization. It is useful
2233	   for memory hotplug support but reduces the entropy available for
2234	   address randomization.
2235
2236	   If unsure, leave at the default value.
2237
2238config HOTPLUG_CPU
2239	def_bool y
2240	depends on SMP
2241
2242config BOOTPARAM_HOTPLUG_CPU0
2243	bool "Set default setting of cpu0_hotpluggable"
2244	depends on HOTPLUG_CPU
2245	help
2246	  Set whether default state of cpu0_hotpluggable is on or off.
2247
2248	  Say Y here to enable CPU0 hotplug by default. If this switch
2249	  is turned on, there is no need to give cpu0_hotplug kernel
2250	  parameter and the CPU0 hotplug feature is enabled by default.
2251
2252	  Please note: there are two known CPU0 dependencies if you want
2253	  to enable the CPU0 hotplug feature either by this switch or by
2254	  cpu0_hotplug kernel parameter.
2255
2256	  First, resume from hibernate or suspend always starts from CPU0.
2257	  So hibernate and suspend are prevented if CPU0 is offline.
2258
2259	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2260	  offline if any interrupt can not migrate out of CPU0. There may
2261	  be other CPU0 dependencies.
2262
2263	  Please make sure the dependencies are under your control before
2264	  you enable this feature.
2265
2266	  Say N if you don't want to enable CPU0 hotplug feature by default.
2267	  You still can enable the CPU0 hotplug feature at boot by kernel
2268	  parameter cpu0_hotplug.
2269
2270config DEBUG_HOTPLUG_CPU0
2271	def_bool n
2272	prompt "Debug CPU0 hotplug"
2273	depends on HOTPLUG_CPU
2274	help
2275	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2276	  soon as possible and boots up userspace with CPU0 offlined. User
2277	  can online CPU0 back after boot time.
2278
2279	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2280	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2281	  compilation or giving cpu0_hotplug kernel parameter at boot.
2282
2283	  If unsure, say N.
2284
2285config COMPAT_VDSO
2286	def_bool n
2287	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2288	depends on COMPAT_32
2289	help
2290	  Certain buggy versions of glibc will crash if they are
2291	  presented with a 32-bit vDSO that is not mapped at the address
2292	  indicated in its segment table.
2293
2294	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2295	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2296	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2297	  the only released version with the bug, but OpenSUSE 9
2298	  contains a buggy "glibc 2.3.2".
2299
2300	  The symptom of the bug is that everything crashes on startup, saying:
2301	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2302
2303	  Saying Y here changes the default value of the vdso32 boot
2304	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2305	  This works around the glibc bug but hurts performance.
2306
2307	  If unsure, say N: if you are compiling your own kernel, you
2308	  are unlikely to be using a buggy version of glibc.
2309
2310choice
2311	prompt "vsyscall table for legacy applications"
2312	depends on X86_64
2313	default LEGACY_VSYSCALL_XONLY
2314	help
2315	  Legacy user code that does not know how to find the vDSO expects
2316	  to be able to issue three syscalls by calling fixed addresses in
2317	  kernel space. Since this location is not randomized with ASLR,
2318	  it can be used to assist security vulnerability exploitation.
2319
2320	  This setting can be changed at boot time via the kernel command
2321	  line parameter vsyscall=[emulate|xonly|none].
2322
2323	  On a system with recent enough glibc (2.14 or newer) and no
2324	  static binaries, you can say None without a performance penalty
2325	  to improve security.
2326
2327	  If unsure, select "Emulate execution only".
2328
2329	config LEGACY_VSYSCALL_EMULATE
2330		bool "Full emulation"
2331		help
2332		  The kernel traps and emulates calls into the fixed vsyscall
2333		  address mapping. This makes the mapping non-executable, but
2334		  it still contains readable known contents, which could be
2335		  used in certain rare security vulnerability exploits. This
2336		  configuration is recommended when using legacy userspace
2337		  that still uses vsyscalls along with legacy binary
2338		  instrumentation tools that require code to be readable.
2339
2340		  An example of this type of legacy userspace is running
2341		  Pin on an old binary that still uses vsyscalls.
2342
2343	config LEGACY_VSYSCALL_XONLY
2344		bool "Emulate execution only"
2345		help
2346		  The kernel traps and emulates calls into the fixed vsyscall
2347		  address mapping and does not allow reads.  This
2348		  configuration is recommended when userspace might use the
2349		  legacy vsyscall area but support for legacy binary
2350		  instrumentation of legacy code is not needed.  It mitigates
2351		  certain uses of the vsyscall area as an ASLR-bypassing
2352		  buffer.
2353
2354	config LEGACY_VSYSCALL_NONE
2355		bool "None"
2356		help
2357		  There will be no vsyscall mapping at all. This will
2358		  eliminate any risk of ASLR bypass due to the vsyscall
2359		  fixed address mapping. Attempts to use the vsyscalls
2360		  will be reported to dmesg, so that either old or
2361		  malicious userspace programs can be identified.
2362
2363endchoice
2364
2365config CMDLINE_BOOL
2366	bool "Built-in kernel command line"
2367	help
2368	  Allow for specifying boot arguments to the kernel at
2369	  build time.  On some systems (e.g. embedded ones), it is
2370	  necessary or convenient to provide some or all of the
2371	  kernel boot arguments with the kernel itself (that is,
2372	  to not rely on the boot loader to provide them.)
2373
2374	  To compile command line arguments into the kernel,
2375	  set this option to 'Y', then fill in the
2376	  boot arguments in CONFIG_CMDLINE.
2377
2378	  Systems with fully functional boot loaders (i.e. non-embedded)
2379	  should leave this option set to 'N'.
2380
2381config CMDLINE
2382	string "Built-in kernel command string"
2383	depends on CMDLINE_BOOL
2384	default ""
2385	help
2386	  Enter arguments here that should be compiled into the kernel
2387	  image and used at boot time.  If the boot loader provides a
2388	  command line at boot time, it is appended to this string to
2389	  form the full kernel command line, when the system boots.
2390
2391	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2392	  change this behavior.
2393
2394	  In most cases, the command line (whether built-in or provided
2395	  by the boot loader) should specify the device for the root
2396	  file system.
2397
2398config CMDLINE_OVERRIDE
2399	bool "Built-in command line overrides boot loader arguments"
2400	depends on CMDLINE_BOOL && CMDLINE != ""
2401	help
2402	  Set this option to 'Y' to have the kernel ignore the boot loader
2403	  command line, and use ONLY the built-in command line.
2404
2405	  This is used to work around broken boot loaders.  This should
2406	  be set to 'N' under normal conditions.
2407
2408config MODIFY_LDT_SYSCALL
2409	bool "Enable the LDT (local descriptor table)" if EXPERT
2410	default y
2411	help
2412	  Linux can allow user programs to install a per-process x86
2413	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2414	  call.  This is required to run 16-bit or segmented code such as
2415	  DOSEMU or some Wine programs.  It is also used by some very old
2416	  threading libraries.
2417
2418	  Enabling this feature adds a small amount of overhead to
2419	  context switches and increases the low-level kernel attack
2420	  surface.  Disabling it removes the modify_ldt(2) system call.
2421
2422	  Saying 'N' here may make sense for embedded or server kernels.
2423
2424source "kernel/livepatch/Kconfig"
2425
2426endmenu
2427
2428config ARCH_HAS_ADD_PAGES
2429	def_bool y
2430	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2431
2432config ARCH_ENABLE_MEMORY_HOTPLUG
2433	def_bool y
2434	depends on X86_64 || (X86_32 && HIGHMEM)
2435
2436config ARCH_ENABLE_MEMORY_HOTREMOVE
2437	def_bool y
2438	depends on MEMORY_HOTPLUG
2439
2440config USE_PERCPU_NUMA_NODE_ID
2441	def_bool y
2442	depends on NUMA
2443
2444config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2445	def_bool y
2446	depends on X86_64 || X86_PAE
2447
2448config ARCH_ENABLE_HUGEPAGE_MIGRATION
2449	def_bool y
2450	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2451
2452config ARCH_ENABLE_THP_MIGRATION
2453	def_bool y
2454	depends on X86_64 && TRANSPARENT_HUGEPAGE
2455
2456menu "Power management and ACPI options"
2457
2458config ARCH_HIBERNATION_HEADER
2459	def_bool y
2460	depends on HIBERNATION
2461
2462source "kernel/power/Kconfig"
2463
2464source "drivers/acpi/Kconfig"
2465
2466source "drivers/sfi/Kconfig"
2467
2468config X86_APM_BOOT
2469	def_bool y
2470	depends on APM
2471
2472menuconfig APM
2473	tristate "APM (Advanced Power Management) BIOS support"
2474	depends on X86_32 && PM_SLEEP
2475	help
2476	  APM is a BIOS specification for saving power using several different
2477	  techniques. This is mostly useful for battery powered laptops with
2478	  APM compliant BIOSes. If you say Y here, the system time will be
2479	  reset after a RESUME operation, the /proc/apm device will provide
2480	  battery status information, and user-space programs will receive
2481	  notification of APM "events" (e.g. battery status change).
2482
2483	  If you select "Y" here, you can disable actual use of the APM
2484	  BIOS by passing the "apm=off" option to the kernel at boot time.
2485
2486	  Note that the APM support is almost completely disabled for
2487	  machines with more than one CPU.
2488
2489	  In order to use APM, you will need supporting software. For location
2490	  and more information, read <file:Documentation/power/apm-acpi.rst>
2491	  and the Battery Powered Linux mini-HOWTO, available from
2492	  <http://www.tldp.org/docs.html#howto>.
2493
2494	  This driver does not spin down disk drives (see the hdparm(8)
2495	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2496	  VESA-compliant "green" monitors.
2497
2498	  This driver does not support the TI 4000M TravelMate and the ACER
2499	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2500	  desktop machines also don't have compliant BIOSes, and this driver
2501	  may cause those machines to panic during the boot phase.
2502
2503	  Generally, if you don't have a battery in your machine, there isn't
2504	  much point in using this driver and you should say N. If you get
2505	  random kernel OOPSes or reboots that don't seem to be related to
2506	  anything, try disabling/enabling this option (or disabling/enabling
2507	  APM in your BIOS).
2508
2509	  Some other things you should try when experiencing seemingly random,
2510	  "weird" problems:
2511
2512	  1) make sure that you have enough swap space and that it is
2513	  enabled.
2514	  2) pass the "no-hlt" option to the kernel
2515	  3) switch on floating point emulation in the kernel and pass
2516	  the "no387" option to the kernel
2517	  4) pass the "floppy=nodma" option to the kernel
2518	  5) pass the "mem=4M" option to the kernel (thereby disabling
2519	  all but the first 4 MB of RAM)
2520	  6) make sure that the CPU is not over clocked.
2521	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2522	  8) disable the cache from your BIOS settings
2523	  9) install a fan for the video card or exchange video RAM
2524	  10) install a better fan for the CPU
2525	  11) exchange RAM chips
2526	  12) exchange the motherboard.
2527
2528	  To compile this driver as a module, choose M here: the
2529	  module will be called apm.
2530
2531if APM
2532
2533config APM_IGNORE_USER_SUSPEND
2534	bool "Ignore USER SUSPEND"
2535	help
2536	  This option will ignore USER SUSPEND requests. On machines with a
2537	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2538	  series notebooks, it is necessary to say Y because of a BIOS bug.
2539
2540config APM_DO_ENABLE
2541	bool "Enable PM at boot time"
2542	help
2543	  Enable APM features at boot time. From page 36 of the APM BIOS
2544	  specification: "When disabled, the APM BIOS does not automatically
2545	  power manage devices, enter the Standby State, enter the Suspend
2546	  State, or take power saving steps in response to CPU Idle calls."
2547	  This driver will make CPU Idle calls when Linux is idle (unless this
2548	  feature is turned off -- see "Do CPU IDLE calls", below). This
2549	  should always save battery power, but more complicated APM features
2550	  will be dependent on your BIOS implementation. You may need to turn
2551	  this option off if your computer hangs at boot time when using APM
2552	  support, or if it beeps continuously instead of suspending. Turn
2553	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2554	  T400CDT. This is off by default since most machines do fine without
2555	  this feature.
2556
2557config APM_CPU_IDLE
2558	depends on CPU_IDLE
2559	bool "Make CPU Idle calls when idle"
2560	help
2561	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2562	  On some machines, this can activate improved power savings, such as
2563	  a slowed CPU clock rate, when the machine is idle. These idle calls
2564	  are made after the idle loop has run for some length of time (e.g.,
2565	  333 mS). On some machines, this will cause a hang at boot time or
2566	  whenever the CPU becomes idle. (On machines with more than one CPU,
2567	  this option does nothing.)
2568
2569config APM_DISPLAY_BLANK
2570	bool "Enable console blanking using APM"
2571	help
2572	  Enable console blanking using the APM. Some laptops can use this to
2573	  turn off the LCD backlight when the screen blanker of the Linux
2574	  virtual console blanks the screen. Note that this is only used by
2575	  the virtual console screen blanker, and won't turn off the backlight
2576	  when using the X Window system. This also doesn't have anything to
2577	  do with your VESA-compliant power-saving monitor. Further, this
2578	  option doesn't work for all laptops -- it might not turn off your
2579	  backlight at all, or it might print a lot of errors to the console,
2580	  especially if you are using gpm.
2581
2582config APM_ALLOW_INTS
2583	bool "Allow interrupts during APM BIOS calls"
2584	help
2585	  Normally we disable external interrupts while we are making calls to
2586	  the APM BIOS as a measure to lessen the effects of a badly behaving
2587	  BIOS implementation.  The BIOS should reenable interrupts if it
2588	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2589	  many of the newer IBM Thinkpads.  If you experience hangs when you
2590	  suspend, try setting this to Y.  Otherwise, say N.
2591
2592endif # APM
2593
2594source "drivers/cpufreq/Kconfig"
2595
2596source "drivers/cpuidle/Kconfig"
2597
2598source "drivers/idle/Kconfig"
2599
2600endmenu
2601
2602
2603menu "Bus options (PCI etc.)"
2604
2605choice
2606	prompt "PCI access mode"
2607	depends on X86_32 && PCI
2608	default PCI_GOANY
2609	help
2610	  On PCI systems, the BIOS can be used to detect the PCI devices and
2611	  determine their configuration. However, some old PCI motherboards
2612	  have BIOS bugs and may crash if this is done. Also, some embedded
2613	  PCI-based systems don't have any BIOS at all. Linux can also try to
2614	  detect the PCI hardware directly without using the BIOS.
2615
2616	  With this option, you can specify how Linux should detect the
2617	  PCI devices. If you choose "BIOS", the BIOS will be used,
2618	  if you choose "Direct", the BIOS won't be used, and if you
2619	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2620	  If you choose "Any", the kernel will try MMCONFIG, then the
2621	  direct access method and falls back to the BIOS if that doesn't
2622	  work. If unsure, go with the default, which is "Any".
2623
2624config PCI_GOBIOS
2625	bool "BIOS"
2626
2627config PCI_GOMMCONFIG
2628	bool "MMConfig"
2629
2630config PCI_GODIRECT
2631	bool "Direct"
2632
2633config PCI_GOOLPC
2634	bool "OLPC XO-1"
2635	depends on OLPC
2636
2637config PCI_GOANY
2638	bool "Any"
2639
2640endchoice
2641
2642config PCI_BIOS
2643	def_bool y
2644	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2645
2646# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2647config PCI_DIRECT
2648	def_bool y
2649	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2650
2651config PCI_MMCONFIG
2652	bool "Support mmconfig PCI config space access" if X86_64
2653	default y
2654	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2655	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2656
2657config PCI_OLPC
2658	def_bool y
2659	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2660
2661config PCI_XEN
2662	def_bool y
2663	depends on PCI && XEN
2664	select SWIOTLB_XEN
2665
2666config MMCONF_FAM10H
2667	def_bool y
2668	depends on X86_64 && PCI_MMCONFIG && ACPI
2669
2670config PCI_CNB20LE_QUIRK
2671	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2672	depends on PCI
2673	help
2674	  Read the PCI windows out of the CNB20LE host bridge. This allows
2675	  PCI hotplug to work on systems with the CNB20LE chipset which do
2676	  not have ACPI.
2677
2678	  There's no public spec for this chipset, and this functionality
2679	  is known to be incomplete.
2680
2681	  You should say N unless you know you need this.
2682
2683config ISA_BUS
2684	bool "ISA bus support on modern systems" if EXPERT
2685	help
2686	  Expose ISA bus device drivers and options available for selection and
2687	  configuration. Enable this option if your target machine has an ISA
2688	  bus. ISA is an older system, displaced by PCI and newer bus
2689	  architectures -- if your target machine is modern, it probably does
2690	  not have an ISA bus.
2691
2692	  If unsure, say N.
2693
2694# x86_64 have no ISA slots, but can have ISA-style DMA.
2695config ISA_DMA_API
2696	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2697	default y
2698	help
2699	  Enables ISA-style DMA support for devices requiring such controllers.
2700	  If unsure, say Y.
2701
2702if X86_32
2703
2704config ISA
2705	bool "ISA support"
2706	help
2707	  Find out whether you have ISA slots on your motherboard.  ISA is the
2708	  name of a bus system, i.e. the way the CPU talks to the other stuff
2709	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2710	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2711	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2712
2713config SCx200
2714	tristate "NatSemi SCx200 support"
2715	help
2716	  This provides basic support for National Semiconductor's
2717	  (now AMD's) Geode processors.  The driver probes for the
2718	  PCI-IDs of several on-chip devices, so its a good dependency
2719	  for other scx200_* drivers.
2720
2721	  If compiled as a module, the driver is named scx200.
2722
2723config SCx200HR_TIMER
2724	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2725	depends on SCx200
2726	default y
2727	help
2728	  This driver provides a clocksource built upon the on-chip
2729	  27MHz high-resolution timer.  Its also a workaround for
2730	  NSC Geode SC-1100's buggy TSC, which loses time when the
2731	  processor goes idle (as is done by the scheduler).  The
2732	  other workaround is idle=poll boot option.
2733
2734config OLPC
2735	bool "One Laptop Per Child support"
2736	depends on !X86_PAE
2737	select GPIOLIB
2738	select OF
2739	select OF_PROMTREE
2740	select IRQ_DOMAIN
2741	select OLPC_EC
2742	help
2743	  Add support for detecting the unique features of the OLPC
2744	  XO hardware.
2745
2746config OLPC_XO1_PM
2747	bool "OLPC XO-1 Power Management"
2748	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2749	help
2750	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2751
2752config OLPC_XO1_RTC
2753	bool "OLPC XO-1 Real Time Clock"
2754	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2755	help
2756	  Add support for the XO-1 real time clock, which can be used as a
2757	  programmable wakeup source.
2758
2759config OLPC_XO1_SCI
2760	bool "OLPC XO-1 SCI extras"
2761	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2762	depends on INPUT=y
2763	select POWER_SUPPLY
2764	help
2765	  Add support for SCI-based features of the OLPC XO-1 laptop:
2766	   - EC-driven system wakeups
2767	   - Power button
2768	   - Ebook switch
2769	   - Lid switch
2770	   - AC adapter status updates
2771	   - Battery status updates
2772
2773config OLPC_XO15_SCI
2774	bool "OLPC XO-1.5 SCI extras"
2775	depends on OLPC && ACPI
2776	select POWER_SUPPLY
2777	help
2778	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2779	   - EC-driven system wakeups
2780	   - AC adapter status updates
2781	   - Battery status updates
2782
2783config ALIX
2784	bool "PCEngines ALIX System Support (LED setup)"
2785	select GPIOLIB
2786	help
2787	  This option enables system support for the PCEngines ALIX.
2788	  At present this just sets up LEDs for GPIO control on
2789	  ALIX2/3/6 boards.  However, other system specific setup should
2790	  get added here.
2791
2792	  Note: You must still enable the drivers for GPIO and LED support
2793	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2794
2795	  Note: You have to set alix.force=1 for boards with Award BIOS.
2796
2797config NET5501
2798	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2799	select GPIOLIB
2800	help
2801	  This option enables system support for the Soekris Engineering net5501.
2802
2803config GEOS
2804	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2805	select GPIOLIB
2806	depends on DMI
2807	help
2808	  This option enables system support for the Traverse Technologies GEOS.
2809
2810config TS5500
2811	bool "Technologic Systems TS-5500 platform support"
2812	depends on MELAN
2813	select CHECK_SIGNATURE
2814	select NEW_LEDS
2815	select LEDS_CLASS
2816	help
2817	  This option enables system support for the Technologic Systems TS-5500.
2818
2819endif # X86_32
2820
2821config AMD_NB
2822	def_bool y
2823	depends on CPU_SUP_AMD && PCI
2824
2825config X86_SYSFB
2826	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2827	help
2828	  Firmwares often provide initial graphics framebuffers so the BIOS,
2829	  bootloader or kernel can show basic video-output during boot for
2830	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2831	  Extensions and EFI-framebuffers for this, which are mostly limited
2832	  to x86.
2833	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2834	  framebuffers so the new generic system-framebuffer drivers can be
2835	  used on x86. If the framebuffer is not compatible with the generic
2836	  modes, it is advertised as fallback platform framebuffer so legacy
2837	  drivers like efifb, vesafb and uvesafb can pick it up.
2838	  If this option is not selected, all system framebuffers are always
2839	  marked as fallback platform framebuffers as usual.
2840
2841	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2842	  not be able to pick up generic system framebuffers if this option
2843	  is selected. You are highly encouraged to enable simplefb as
2844	  replacement if you select this option. simplefb can correctly deal
2845	  with generic system framebuffers. But you should still keep vesafb
2846	  and others enabled as fallback if a system framebuffer is
2847	  incompatible with simplefb.
2848
2849	  If unsure, say Y.
2850
2851endmenu
2852
2853
2854menu "Binary Emulations"
2855
2856config IA32_EMULATION
2857	bool "IA32 Emulation"
2858	depends on X86_64
2859	select ARCH_WANT_OLD_COMPAT_IPC
2860	select BINFMT_ELF
2861	select COMPAT_BINFMT_ELF
2862	select COMPAT_OLD_SIGACTION
2863	help
2864	  Include code to run legacy 32-bit programs under a
2865	  64-bit kernel. You should likely turn this on, unless you're
2866	  100% sure that you don't have any 32-bit programs left.
2867
2868config IA32_AOUT
2869	tristate "IA32 a.out support"
2870	depends on IA32_EMULATION
2871	depends on BROKEN
2872	help
2873	  Support old a.out binaries in the 32bit emulation.
2874
2875config X86_X32
2876	bool "x32 ABI for 64-bit mode"
2877	depends on X86_64
2878	help
2879	  Include code to run binaries for the x32 native 32-bit ABI
2880	  for 64-bit processors.  An x32 process gets access to the
2881	  full 64-bit register file and wide data path while leaving
2882	  pointers at 32 bits for smaller memory footprint.
2883
2884	  You will need a recent binutils (2.22 or later) with
2885	  elf32_x86_64 support enabled to compile a kernel with this
2886	  option set.
2887
2888config COMPAT_32
2889	def_bool y
2890	depends on IA32_EMULATION || X86_32
2891	select HAVE_UID16
2892	select OLD_SIGSUSPEND3
2893
2894config COMPAT
2895	def_bool y
2896	depends on IA32_EMULATION || X86_X32
2897
2898if COMPAT
2899config COMPAT_FOR_U64_ALIGNMENT
2900	def_bool y
2901
2902config SYSVIPC_COMPAT
2903	def_bool y
2904	depends on SYSVIPC
2905endif
2906
2907endmenu
2908
2909
2910config HAVE_ATOMIC_IOMAP
2911	def_bool y
2912	depends on X86_32
2913
2914source "drivers/firmware/Kconfig"
2915
2916source "arch/x86/kvm/Kconfig"
2917
2918source "arch/x86/Kconfig.assembler"
2919