xref: /openbmc/linux/arch/x86/Kconfig (revision 519a8a6c)
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_UACCESS_MCSAFE		if X86_64 && X86_MCE
79	select ARCH_HAS_SET_MEMORY
80	select ARCH_HAS_SET_DIRECT_MAP
81	select ARCH_HAS_STRICT_KERNEL_RWX
82	select ARCH_HAS_STRICT_MODULE_RWX
83	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
84	select ARCH_HAS_SYSCALL_WRAPPER
85	select ARCH_HAS_UBSAN_SANITIZE_ALL
86	select ARCH_HAS_DEBUG_WX
87	select ARCH_HAVE_NMI_SAFE_CMPXCHG
88	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
89	select ARCH_MIGHT_HAVE_PC_PARPORT
90	select ARCH_MIGHT_HAVE_PC_SERIO
91	select ARCH_STACKWALK
92	select ARCH_SUPPORTS_ACPI
93	select ARCH_SUPPORTS_ATOMIC_RMW
94	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
95	select ARCH_USE_BUILTIN_BSWAP
96	select ARCH_USE_QUEUED_RWLOCKS
97	select ARCH_USE_QUEUED_SPINLOCKS
98	select ARCH_USE_SYM_ANNOTATIONS
99	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
100	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
101	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
102	select ARCH_WANT_HUGE_PMD_SHARE
103	select ARCH_WANTS_THP_SWAP		if X86_64
104	select BUILDTIME_TABLE_SORT
105	select CLKEVT_I8253
106	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107	select CLOCKSOURCE_WATCHDOG
108	select DCACHE_WORD_ACCESS
109	select EDAC_ATOMIC_SCRUB
110	select EDAC_SUPPORT
111	select GENERIC_CLOCKEVENTS
112	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
113	select GENERIC_CLOCKEVENTS_MIN_ADJUST
114	select GENERIC_CMOS_UPDATE
115	select GENERIC_CPU_AUTOPROBE
116	select GENERIC_CPU_VULNERABILITIES
117	select GENERIC_EARLY_IOREMAP
118	select GENERIC_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_REGS_AND_STACK_ACCESS_API
213	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
214	select HAVE_FUNCTION_ARG_ACCESS_API
215	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
216	select HAVE_STACK_VALIDATION		if X86_64
217	select HAVE_RSEQ
218	select HAVE_SYSCALL_TRACEPOINTS
219	select HAVE_UNSTABLE_SCHED_CLOCK
220	select HAVE_USER_RETURN_NOTIFIER
221	select HAVE_GENERIC_VDSO
222	select HOTPLUG_SMT			if SMP
223	select IRQ_FORCED_THREADING
224	select NEED_SG_DMA_LENGTH
225	select PCI_DOMAINS			if PCI
226	select PCI_LOCKLESS_CONFIG		if PCI
227	select PERF_EVENTS
228	select RTC_LIB
229	select RTC_MC146818_LIB
230	select SPARSE_IRQ
231	select SRCU
232	select SYSCTL_EXCEPTION_TRACE
233	select THREAD_INFO_IN_TASK
234	select USER_STACKTRACE_SUPPORT
235	select VIRT_TO_BUS
236	select HAVE_ARCH_KCSAN			if X86_64
237	select X86_FEATURE_NAMES		if PROC_FS
238	select PROC_PID_ARCH_STATUS		if PROC_FS
239	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
240
241config INSTRUCTION_DECODER
242	def_bool y
243	depends on KPROBES || PERF_EVENTS || UPROBES
244
245config OUTPUT_FORMAT
246	string
247	default "elf32-i386" if X86_32
248	default "elf64-x86-64" if X86_64
249
250config LOCKDEP_SUPPORT
251	def_bool y
252
253config STACKTRACE_SUPPORT
254	def_bool y
255
256config MMU
257	def_bool y
258
259config ARCH_MMAP_RND_BITS_MIN
260	default 28 if 64BIT
261	default 8
262
263config ARCH_MMAP_RND_BITS_MAX
264	default 32 if 64BIT
265	default 16
266
267config ARCH_MMAP_RND_COMPAT_BITS_MIN
268	default 8
269
270config ARCH_MMAP_RND_COMPAT_BITS_MAX
271	default 16
272
273config SBUS
274	bool
275
276config GENERIC_ISA_DMA
277	def_bool y
278	depends on ISA_DMA_API
279
280config GENERIC_BUG
281	def_bool y
282	depends on BUG
283	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
284
285config GENERIC_BUG_RELATIVE_POINTERS
286	bool
287
288config ARCH_MAY_HAVE_PC_FDC
289	def_bool y
290	depends on ISA_DMA_API
291
292config GENERIC_CALIBRATE_DELAY
293	def_bool y
294
295config ARCH_HAS_CPU_RELAX
296	def_bool y
297
298config ARCH_HAS_CACHE_LINE_SIZE
299	def_bool y
300
301config ARCH_HAS_FILTER_PGPROT
302	def_bool y
303
304config HAVE_SETUP_PER_CPU_AREA
305	def_bool y
306
307config NEED_PER_CPU_EMBED_FIRST_CHUNK
308	def_bool y
309
310config NEED_PER_CPU_PAGE_FIRST_CHUNK
311	def_bool y
312
313config ARCH_HIBERNATION_POSSIBLE
314	def_bool y
315
316config ARCH_SUSPEND_POSSIBLE
317	def_bool y
318
319config ARCH_WANT_GENERAL_HUGETLB
320	def_bool y
321
322config ZONE_DMA32
323	def_bool y if X86_64
324
325config AUDIT_ARCH
326	def_bool y if X86_64
327
328config ARCH_SUPPORTS_DEBUG_PAGEALLOC
329	def_bool y
330
331config KASAN_SHADOW_OFFSET
332	hex
333	depends on KASAN
334	default 0xdffffc0000000000
335
336config HAVE_INTEL_TXT
337	def_bool y
338	depends on INTEL_IOMMU && ACPI
339
340config X86_32_SMP
341	def_bool y
342	depends on X86_32 && SMP
343
344config X86_64_SMP
345	def_bool y
346	depends on X86_64 && SMP
347
348config X86_32_LAZY_GS
349	def_bool y
350	depends on X86_32 && !STACKPROTECTOR
351
352config ARCH_SUPPORTS_UPROBES
353	def_bool y
354
355config FIX_EARLYCON_MEM
356	def_bool y
357
358config DYNAMIC_PHYSICAL_MASK
359	bool
360
361config PGTABLE_LEVELS
362	int
363	default 5 if X86_5LEVEL
364	default 4 if X86_64
365	default 3 if X86_PAE
366	default 2
367
368config CC_HAS_SANE_STACKPROTECTOR
369	bool
370	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
371	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
372	help
373	   We have to make sure stack protector is unconditionally disabled if
374	   the compiler produces broken code.
375
376menu "Processor type and features"
377
378config ZONE_DMA
379	bool "DMA memory allocation support" if EXPERT
380	default y
381	help
382	  DMA memory allocation support allows devices with less than 32-bit
383	  addressing to allocate within the first 16MB of address space.
384	  Disable if no such devices will be used.
385
386	  If unsure, say Y.
387
388config SMP
389	bool "Symmetric multi-processing support"
390	help
391	  This enables support for systems with more than one CPU. If you have
392	  a system with only one CPU, say N. If you have a system with more
393	  than one CPU, say Y.
394
395	  If you say N here, the kernel will run on uni- and multiprocessor
396	  machines, but will use only one CPU of a multiprocessor machine. If
397	  you say Y here, the kernel will run on many, but not all,
398	  uniprocessor machines. On a uniprocessor machine, the kernel
399	  will run faster if you say N here.
400
401	  Note that if you say Y here and choose architecture "586" or
402	  "Pentium" under "Processor family", the kernel will not work on 486
403	  architectures. Similarly, multiprocessor kernels for the "PPro"
404	  architecture may not work on all Pentium based boards.
405
406	  People using multiprocessor machines who say Y here should also say
407	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
408	  Management" code will be disabled if you say Y here.
409
410	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
411	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
412	  <http://www.tldp.org/docs.html#howto>.
413
414	  If you don't know what to do here, say N.
415
416config X86_FEATURE_NAMES
417	bool "Processor feature human-readable names" if EMBEDDED
418	default y
419	help
420	  This option compiles in a table of x86 feature bits and corresponding
421	  names.  This is required to support /proc/cpuinfo and a few kernel
422	  messages.  You can disable this to save space, at the expense of
423	  making those few kernel messages show numeric feature bits instead.
424
425	  If in doubt, say Y.
426
427config X86_X2APIC
428	bool "Support x2apic"
429	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
430	help
431	  This enables x2apic support on CPUs that have this feature.
432
433	  This allows 32-bit apic IDs (so it can support very large systems),
434	  and accesses the local apic via MSRs not via mmio.
435
436	  If you don't know what to do here, say N.
437
438config X86_MPPARSE
439	bool "Enable MPS table" if ACPI || SFI
440	default y
441	depends on X86_LOCAL_APIC
442	help
443	  For old smp systems that do not have proper acpi support. Newer systems
444	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
445
446config GOLDFISH
447	def_bool y
448	depends on X86_GOLDFISH
449
450config RETPOLINE
451	bool "Avoid speculative indirect branches in kernel"
452	default y
453	select STACK_VALIDATION if HAVE_STACK_VALIDATION
454	help
455	  Compile kernel with the retpoline compiler options to guard against
456	  kernel-to-user data leaks by avoiding speculative indirect
457	  branches. Requires a compiler with -mindirect-branch=thunk-extern
458	  support for full protection. The kernel may run slower.
459
460config X86_CPU_RESCTRL
461	bool "x86 CPU resource control support"
462	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
463	select KERNFS
464	select PROC_CPU_RESCTRL		if PROC_FS
465	help
466	  Enable x86 CPU resource control support.
467
468	  Provide support for the allocation and monitoring of system resources
469	  usage by the CPU.
470
471	  Intel calls this Intel Resource Director Technology
472	  (Intel(R) RDT). More information about RDT can be found in the
473	  Intel x86 Architecture Software Developer Manual.
474
475	  AMD calls this AMD Platform Quality of Service (AMD QoS).
476	  More information about AMD QoS can be found in the AMD64 Technology
477	  Platform Quality of Service Extensions manual.
478
479	  Say N if unsure.
480
481if X86_32
482config X86_BIGSMP
483	bool "Support for big SMP systems with more than 8 CPUs"
484	depends on SMP
485	help
486	  This option is needed for the systems that have more than 8 CPUs.
487
488config X86_EXTENDED_PLATFORM
489	bool "Support for extended (non-PC) x86 platforms"
490	default y
491	help
492	  If you disable this option then the kernel will only support
493	  standard PC platforms. (which covers the vast majority of
494	  systems out there.)
495
496	  If you enable this option then you'll be able to select support
497	  for the following (non-PC) 32 bit x86 platforms:
498		Goldfish (Android emulator)
499		AMD Elan
500		RDC R-321x SoC
501		SGI 320/540 (Visual Workstation)
502		STA2X11-based (e.g. Northville)
503		Moorestown MID devices
504
505	  If you have one of these systems, or if you want to build a
506	  generic distribution kernel, say Y here - otherwise say N.
507endif
508
509if X86_64
510config X86_EXTENDED_PLATFORM
511	bool "Support for extended (non-PC) x86 platforms"
512	default y
513	help
514	  If you disable this option then the kernel will only support
515	  standard PC platforms. (which covers the vast majority of
516	  systems out there.)
517
518	  If you enable this option then you'll be able to select support
519	  for the following (non-PC) 64 bit x86 platforms:
520		Numascale NumaChip
521		ScaleMP vSMP
522		SGI Ultraviolet
523
524	  If you have one of these systems, or if you want to build a
525	  generic distribution kernel, say Y here - otherwise say N.
526endif
527# This is an alphabetically sorted list of 64 bit extended platforms
528# Please maintain the alphabetic order if and when there are additions
529config X86_NUMACHIP
530	bool "Numascale NumaChip"
531	depends on X86_64
532	depends on X86_EXTENDED_PLATFORM
533	depends on NUMA
534	depends on SMP
535	depends on X86_X2APIC
536	depends on PCI_MMCONFIG
537	help
538	  Adds support for Numascale NumaChip large-SMP systems. Needed to
539	  enable more than ~168 cores.
540	  If you don't have one of these, you should say N here.
541
542config X86_VSMP
543	bool "ScaleMP vSMP"
544	select HYPERVISOR_GUEST
545	select PARAVIRT
546	depends on X86_64 && PCI
547	depends on X86_EXTENDED_PLATFORM
548	depends on SMP
549	help
550	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
551	  supposed to run on these EM64T-based machines.  Only choose this option
552	  if you have one of these machines.
553
554config X86_UV
555	bool "SGI Ultraviolet"
556	depends on X86_64
557	depends on X86_EXTENDED_PLATFORM
558	depends on NUMA
559	depends on EFI
560	depends on X86_X2APIC
561	depends on PCI
562	help
563	  This option is needed in order to support SGI Ultraviolet systems.
564	  If you don't have one of these, you should say N here.
565
566# Following is an alphabetically sorted list of 32 bit extended platforms
567# Please maintain the alphabetic order if and when there are additions
568
569config X86_GOLDFISH
570	bool "Goldfish (Virtual Platform)"
571	depends on X86_EXTENDED_PLATFORM
572	help
573	 Enable support for the Goldfish virtual platform used primarily
574	 for Android development. Unless you are building for the Android
575	 Goldfish emulator say N here.
576
577config X86_INTEL_CE
578	bool "CE4100 TV platform"
579	depends on PCI
580	depends on PCI_GODIRECT
581	depends on X86_IO_APIC
582	depends on X86_32
583	depends on X86_EXTENDED_PLATFORM
584	select X86_REBOOTFIXUPS
585	select OF
586	select OF_EARLY_FLATTREE
587	help
588	  Select for the Intel CE media processor (CE4100) SOC.
589	  This option compiles in support for the CE4100 SOC for settop
590	  boxes and media devices.
591
592config X86_INTEL_MID
593	bool "Intel MID platform support"
594	depends on X86_EXTENDED_PLATFORM
595	depends on X86_PLATFORM_DEVICES
596	depends on PCI
597	depends on X86_64 || (PCI_GOANY && X86_32)
598	depends on X86_IO_APIC
599	select SFI
600	select I2C
601	select DW_APB_TIMER
602	select APB_TIMER
603	select INTEL_SCU_PCI
604	select MFD_INTEL_MSIC
605	help
606	  Select to build a kernel capable of supporting Intel MID (Mobile
607	  Internet Device) platform systems which do not have the PCI legacy
608	  interfaces. If you are building for a PC class system say N here.
609
610	  Intel MID platforms are based on an Intel processor and chipset which
611	  consume less power than most of the x86 derivatives.
612
613config X86_INTEL_QUARK
614	bool "Intel Quark platform support"
615	depends on X86_32
616	depends on X86_EXTENDED_PLATFORM
617	depends on X86_PLATFORM_DEVICES
618	depends on X86_TSC
619	depends on PCI
620	depends on PCI_GOANY
621	depends on X86_IO_APIC
622	select IOSF_MBI
623	select INTEL_IMR
624	select COMMON_CLK
625	help
626	  Select to include support for Quark X1000 SoC.
627	  Say Y here if you have a Quark based system such as the Arduino
628	  compatible Intel Galileo.
629
630config X86_INTEL_LPSS
631	bool "Intel Low Power Subsystem Support"
632	depends on X86 && ACPI && PCI
633	select COMMON_CLK
634	select PINCTRL
635	select IOSF_MBI
636	help
637	  Select to build support for Intel Low Power Subsystem such as
638	  found on Intel Lynxpoint PCH. Selecting this option enables
639	  things like clock tree (common clock framework) and pincontrol
640	  which are needed by the LPSS peripheral drivers.
641
642config X86_AMD_PLATFORM_DEVICE
643	bool "AMD ACPI2Platform devices support"
644	depends on ACPI
645	select COMMON_CLK
646	select PINCTRL
647	help
648	  Select to interpret AMD specific ACPI device to platform device
649	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
650	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
651	  implemented under PINCTRL subsystem.
652
653config IOSF_MBI
654	tristate "Intel SoC IOSF Sideband support for SoC platforms"
655	depends on PCI
656	help
657	  This option enables sideband register access support for Intel SoC
658	  platforms. On these platforms the IOSF sideband is used in lieu of
659	  MSR's for some register accesses, mostly but not limited to thermal
660	  and power. Drivers may query the availability of this device to
661	  determine if they need the sideband in order to work on these
662	  platforms. The sideband is available on the following SoC products.
663	  This list is not meant to be exclusive.
664	   - BayTrail
665	   - Braswell
666	   - Quark
667
668	  You should say Y if you are running a kernel on one of these SoC's.
669
670config IOSF_MBI_DEBUG
671	bool "Enable IOSF sideband access through debugfs"
672	depends on IOSF_MBI && DEBUG_FS
673	help
674	  Select this option to expose the IOSF sideband access registers (MCR,
675	  MDR, MCRX) through debugfs to write and read register information from
676	  different units on the SoC. This is most useful for obtaining device
677	  state information for debug and analysis. As this is a general access
678	  mechanism, users of this option would have specific knowledge of the
679	  device they want to access.
680
681	  If you don't require the option or are in doubt, say N.
682
683config X86_RDC321X
684	bool "RDC R-321x SoC"
685	depends on X86_32
686	depends on X86_EXTENDED_PLATFORM
687	select M486
688	select X86_REBOOTFIXUPS
689	help
690	  This option is needed for RDC R-321x system-on-chip, also known
691	  as R-8610-(G).
692	  If you don't have one of these chips, you should say N here.
693
694config X86_32_NON_STANDARD
695	bool "Support non-standard 32-bit SMP architectures"
696	depends on X86_32 && SMP
697	depends on X86_EXTENDED_PLATFORM
698	help
699	  This option compiles in the bigsmp and STA2X11 default
700	  subarchitectures.  It is intended for a generic binary
701	  kernel. If you select them all, kernel will probe it one by
702	  one and will fallback to default.
703
704# Alphabetically sorted list of Non standard 32 bit platforms
705
706config X86_SUPPORTS_MEMORY_FAILURE
707	def_bool y
708	# MCE code calls memory_failure():
709	depends on X86_MCE
710	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
711	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
712	depends on X86_64 || !SPARSEMEM
713	select ARCH_SUPPORTS_MEMORY_FAILURE
714
715config STA2X11
716	bool "STA2X11 Companion Chip Support"
717	depends on X86_32_NON_STANDARD && PCI
718	select SWIOTLB
719	select MFD_STA2X11
720	select GPIOLIB
721	help
722	  This adds support for boards based on the STA2X11 IO-Hub,
723	  a.k.a. "ConneXt". The chip is used in place of the standard
724	  PC chipset, so all "standard" peripherals are missing. If this
725	  option is selected the kernel will still be able to boot on
726	  standard PC machines.
727
728config X86_32_IRIS
729	tristate "Eurobraille/Iris poweroff module"
730	depends on X86_32
731	help
732	  The Iris machines from EuroBraille do not have APM or ACPI support
733	  to shut themselves down properly.  A special I/O sequence is
734	  needed to do so, which is what this module does at
735	  kernel shutdown.
736
737	  This is only for Iris machines from EuroBraille.
738
739	  If unused, say N.
740
741config SCHED_OMIT_FRAME_POINTER
742	def_bool y
743	prompt "Single-depth WCHAN output"
744	depends on X86
745	help
746	  Calculate simpler /proc/<PID>/wchan values. If this option
747	  is disabled then wchan values will recurse back to the
748	  caller function. This provides more accurate wchan values,
749	  at the expense of slightly more scheduling overhead.
750
751	  If in doubt, say "Y".
752
753menuconfig HYPERVISOR_GUEST
754	bool "Linux guest support"
755	help
756	  Say Y here to enable options for running Linux under various hyper-
757	  visors. This option enables basic hypervisor detection and platform
758	  setup.
759
760	  If you say N, all options in this submenu will be skipped and
761	  disabled, and Linux guest support won't be built in.
762
763if HYPERVISOR_GUEST
764
765config PARAVIRT
766	bool "Enable paravirtualization code"
767	help
768	  This changes the kernel so it can modify itself when it is run
769	  under a hypervisor, potentially improving performance significantly
770	  over full virtualization.  However, when run without a hypervisor
771	  the kernel is theoretically slower and slightly larger.
772
773config PARAVIRT_XXL
774	bool
775
776config PARAVIRT_DEBUG
777	bool "paravirt-ops debugging"
778	depends on PARAVIRT && DEBUG_KERNEL
779	help
780	  Enable to debug paravirt_ops internals.  Specifically, BUG if
781	  a paravirt_op is missing when it is called.
782
783config PARAVIRT_SPINLOCKS
784	bool "Paravirtualization layer for spinlocks"
785	depends on PARAVIRT && SMP
786	help
787	  Paravirtualized spinlocks allow a pvops backend to replace the
788	  spinlock implementation with something virtualization-friendly
789	  (for example, block the virtual CPU rather than spinning).
790
791	  It has a minimal impact on native kernels and gives a nice performance
792	  benefit on paravirtualized KVM / Xen kernels.
793
794	  If you are unsure how to answer this question, answer Y.
795
796config X86_HV_CALLBACK_VECTOR
797	def_bool n
798
799source "arch/x86/xen/Kconfig"
800
801config KVM_GUEST
802	bool "KVM Guest support (including kvmclock)"
803	depends on PARAVIRT
804	select PARAVIRT_CLOCK
805	select ARCH_CPUIDLE_HALTPOLL
806	default y
807	help
808	  This option enables various optimizations for running under the KVM
809	  hypervisor. It includes a paravirtualized clock, so that instead
810	  of relying on a PIT (or probably other) emulation by the
811	  underlying device model, the host provides the guest with
812	  timing infrastructure such as time of day, and system time
813
814config ARCH_CPUIDLE_HALTPOLL
815	def_bool n
816	prompt "Disable host haltpoll when loading haltpoll driver"
817	help
818	  If virtualized under KVM, disable host haltpoll.
819
820config PVH
821	bool "Support for running PVH guests"
822	help
823	  This option enables the PVH entry point for guest virtual machines
824	  as specified in the x86/HVM direct boot ABI.
825
826config PARAVIRT_TIME_ACCOUNTING
827	bool "Paravirtual steal time accounting"
828	depends on PARAVIRT
829	help
830	  Select this option to enable fine granularity task steal time
831	  accounting. Time spent executing other tasks in parallel with
832	  the current vCPU is discounted from the vCPU power. To account for
833	  that, there can be a small performance impact.
834
835	  If in doubt, say N here.
836
837config PARAVIRT_CLOCK
838	bool
839
840config JAILHOUSE_GUEST
841	bool "Jailhouse non-root cell support"
842	depends on X86_64 && PCI
843	select X86_PM_TIMER
844	help
845	  This option allows to run Linux as guest in a Jailhouse non-root
846	  cell. You can leave this option disabled if you only want to start
847	  Jailhouse and run Linux afterwards in the root cell.
848
849config ACRN_GUEST
850	bool "ACRN Guest support"
851	depends on X86_64
852	select X86_HV_CALLBACK_VECTOR
853	help
854	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
855	  a flexible, lightweight reference open-source hypervisor, built with
856	  real-time and safety-criticality in mind. It is built for embedded
857	  IOT with small footprint and real-time features. More details can be
858	  found in https://projectacrn.org/.
859
860endif #HYPERVISOR_GUEST
861
862source "arch/x86/Kconfig.cpu"
863
864config HPET_TIMER
865	def_bool X86_64
866	prompt "HPET Timer Support" if X86_32
867	help
868	  Use the IA-PC HPET (High Precision Event Timer) to manage
869	  time in preference to the PIT and RTC, if a HPET is
870	  present.
871	  HPET is the next generation timer replacing legacy 8254s.
872	  The HPET provides a stable time base on SMP
873	  systems, unlike the TSC, but it is more expensive to access,
874	  as it is off-chip.  The interface used is documented
875	  in the HPET spec, revision 1.
876
877	  You can safely choose Y here.  However, HPET will only be
878	  activated if the platform and the BIOS support this feature.
879	  Otherwise the 8254 will be used for timing services.
880
881	  Choose N to continue using the legacy 8254 timer.
882
883config HPET_EMULATE_RTC
884	def_bool y
885	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
886
887config APB_TIMER
888	def_bool y if X86_INTEL_MID
889	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
890	select DW_APB_TIMER
891	depends on X86_INTEL_MID && SFI
892	help
893	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
894	 The APBT provides a stable time base on SMP
895	 systems, unlike the TSC, but it is more expensive to access,
896	 as it is off-chip. APB timers are always running regardless of CPU
897	 C states, they are used as per CPU clockevent device when possible.
898
899# Mark as expert because too many people got it wrong.
900# The code disables itself when not needed.
901config DMI
902	default y
903	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
904	bool "Enable DMI scanning" if EXPERT
905	help
906	  Enabled scanning of DMI to identify machine quirks. Say Y
907	  here unless you have verified that your setup is not
908	  affected by entries in the DMI blacklist. Required by PNP
909	  BIOS code.
910
911config GART_IOMMU
912	bool "Old AMD GART IOMMU support"
913	select DMA_OPS
914	select IOMMU_HELPER
915	select SWIOTLB
916	depends on X86_64 && PCI && AMD_NB
917	help
918	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
919	  GART based hardware IOMMUs.
920
921	  The GART supports full DMA access for devices with 32-bit access
922	  limitations, on systems with more than 3 GB. This is usually needed
923	  for USB, sound, many IDE/SATA chipsets and some other devices.
924
925	  Newer systems typically have a modern AMD IOMMU, supported via
926	  the CONFIG_AMD_IOMMU=y config option.
927
928	  In normal configurations this driver is only active when needed:
929	  there's more than 3 GB of memory and the system contains a
930	  32-bit limited device.
931
932	  If unsure, say Y.
933
934config MAXSMP
935	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
936	depends on X86_64 && SMP && DEBUG_KERNEL
937	select CPUMASK_OFFSTACK
938	help
939	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
940	  If unsure, say N.
941
942#
943# The maximum number of CPUs supported:
944#
945# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
946# and which can be configured interactively in the
947# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
948#
949# The ranges are different on 32-bit and 64-bit kernels, depending on
950# hardware capabilities and scalability features of the kernel.
951#
952# ( If MAXSMP is enabled we just use the highest possible value and disable
953#   interactive configuration. )
954#
955
956config NR_CPUS_RANGE_BEGIN
957	int
958	default NR_CPUS_RANGE_END if MAXSMP
959	default    1 if !SMP
960	default    2
961
962config NR_CPUS_RANGE_END
963	int
964	depends on X86_32
965	default   64 if  SMP &&  X86_BIGSMP
966	default    8 if  SMP && !X86_BIGSMP
967	default    1 if !SMP
968
969config NR_CPUS_RANGE_END
970	int
971	depends on X86_64
972	default 8192 if  SMP && CPUMASK_OFFSTACK
973	default  512 if  SMP && !CPUMASK_OFFSTACK
974	default    1 if !SMP
975
976config NR_CPUS_DEFAULT
977	int
978	depends on X86_32
979	default   32 if  X86_BIGSMP
980	default    8 if  SMP
981	default    1 if !SMP
982
983config NR_CPUS_DEFAULT
984	int
985	depends on X86_64
986	default 8192 if  MAXSMP
987	default   64 if  SMP
988	default    1 if !SMP
989
990config NR_CPUS
991	int "Maximum number of CPUs" if SMP && !MAXSMP
992	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
993	default NR_CPUS_DEFAULT
994	help
995	  This allows you to specify the maximum number of CPUs which this
996	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
997	  supported value is 8192, otherwise the maximum value is 512.  The
998	  minimum value which makes sense is 2.
999
1000	  This is purely to save memory: each supported CPU adds about 8KB
1001	  to the kernel image.
1002
1003config SCHED_SMT
1004	def_bool y if SMP
1005
1006config SCHED_MC
1007	def_bool y
1008	prompt "Multi-core scheduler support"
1009	depends on SMP
1010	help
1011	  Multi-core scheduler support improves the CPU scheduler's decision
1012	  making when dealing with multi-core CPU chips at a cost of slightly
1013	  increased overhead in some places. If unsure say N here.
1014
1015config SCHED_MC_PRIO
1016	bool "CPU core priorities scheduler support"
1017	depends on SCHED_MC && CPU_SUP_INTEL
1018	select X86_INTEL_PSTATE
1019	select CPU_FREQ
1020	default y
1021	help
1022	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1023	  core ordering determined at manufacturing time, which allows
1024	  certain cores to reach higher turbo frequencies (when running
1025	  single threaded workloads) than others.
1026
1027	  Enabling this kernel feature teaches the scheduler about
1028	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1029	  scheduler's CPU selection logic accordingly, so that higher
1030	  overall system performance can be achieved.
1031
1032	  This feature will have no effect on CPUs without this feature.
1033
1034	  If unsure say Y here.
1035
1036config UP_LATE_INIT
1037	def_bool y
1038	depends on !SMP && X86_LOCAL_APIC
1039
1040config X86_UP_APIC
1041	bool "Local APIC support on uniprocessors" if !PCI_MSI
1042	default PCI_MSI
1043	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1044	help
1045	  A local APIC (Advanced Programmable Interrupt Controller) is an
1046	  integrated interrupt controller in the CPU. If you have a single-CPU
1047	  system which has a processor with a local APIC, you can say Y here to
1048	  enable and use it. If you say Y here even though your machine doesn't
1049	  have a local APIC, then the kernel will still run with no slowdown at
1050	  all. The local APIC supports CPU-generated self-interrupts (timer,
1051	  performance counters), and the NMI watchdog which detects hard
1052	  lockups.
1053
1054config X86_UP_IOAPIC
1055	bool "IO-APIC support on uniprocessors"
1056	depends on X86_UP_APIC
1057	help
1058	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1059	  SMP-capable replacement for PC-style interrupt controllers. Most
1060	  SMP systems and many recent uniprocessor systems have one.
1061
1062	  If you have a single-CPU system with an IO-APIC, you can say Y here
1063	  to use it. If you say Y here even though your machine doesn't have
1064	  an IO-APIC, then the kernel will still run with no slowdown at all.
1065
1066config X86_LOCAL_APIC
1067	def_bool y
1068	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1069	select IRQ_DOMAIN_HIERARCHY
1070	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1071
1072config X86_IO_APIC
1073	def_bool y
1074	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1075
1076config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1077	bool "Reroute for broken boot IRQs"
1078	depends on X86_IO_APIC
1079	help
1080	  This option enables a workaround that fixes a source of
1081	  spurious interrupts. This is recommended when threaded
1082	  interrupt handling is used on systems where the generation of
1083	  superfluous "boot interrupts" cannot be disabled.
1084
1085	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1086	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1087	  kernel does during interrupt handling). On chipsets where this
1088	  boot IRQ generation cannot be disabled, this workaround keeps
1089	  the original IRQ line masked so that only the equivalent "boot
1090	  IRQ" is delivered to the CPUs. The workaround also tells the
1091	  kernel to set up the IRQ handler on the boot IRQ line. In this
1092	  way only one interrupt is delivered to the kernel. Otherwise
1093	  the spurious second interrupt may cause the kernel to bring
1094	  down (vital) interrupt lines.
1095
1096	  Only affects "broken" chipsets. Interrupt sharing may be
1097	  increased on these systems.
1098
1099config X86_MCE
1100	bool "Machine Check / overheating reporting"
1101	select GENERIC_ALLOCATOR
1102	default y
1103	help
1104	  Machine Check support allows the processor to notify the
1105	  kernel if it detects a problem (e.g. overheating, data corruption).
1106	  The action the kernel takes depends on the severity of the problem,
1107	  ranging from warning messages to halting the machine.
1108
1109config X86_MCELOG_LEGACY
1110	bool "Support for deprecated /dev/mcelog character device"
1111	depends on X86_MCE
1112	help
1113	  Enable support for /dev/mcelog which is needed by the old mcelog
1114	  userspace logging daemon. Consider switching to the new generation
1115	  rasdaemon solution.
1116
1117config X86_MCE_INTEL
1118	def_bool y
1119	prompt "Intel MCE features"
1120	depends on X86_MCE && X86_LOCAL_APIC
1121	help
1122	   Additional support for intel specific MCE features such as
1123	   the thermal monitor.
1124
1125config X86_MCE_AMD
1126	def_bool y
1127	prompt "AMD MCE features"
1128	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1129	help
1130	   Additional support for AMD specific MCE features such as
1131	   the DRAM Error Threshold.
1132
1133config X86_ANCIENT_MCE
1134	bool "Support for old Pentium 5 / WinChip machine checks"
1135	depends on X86_32 && X86_MCE
1136	help
1137	  Include support for machine check handling on old Pentium 5 or WinChip
1138	  systems. These typically need to be enabled explicitly on the command
1139	  line.
1140
1141config X86_MCE_THRESHOLD
1142	depends on X86_MCE_AMD || X86_MCE_INTEL
1143	def_bool y
1144
1145config X86_MCE_INJECT
1146	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1147	tristate "Machine check injector support"
1148	help
1149	  Provide support for injecting machine checks for testing purposes.
1150	  If you don't know what a machine check is and you don't do kernel
1151	  QA it is safe to say n.
1152
1153config X86_THERMAL_VECTOR
1154	def_bool y
1155	depends on X86_MCE_INTEL
1156
1157source "arch/x86/events/Kconfig"
1158
1159config X86_LEGACY_VM86
1160	bool "Legacy VM86 support"
1161	depends on X86_32
1162	help
1163	  This option allows user programs to put the CPU into V8086
1164	  mode, which is an 80286-era approximation of 16-bit real mode.
1165
1166	  Some very old versions of X and/or vbetool require this option
1167	  for user mode setting.  Similarly, DOSEMU will use it if
1168	  available to accelerate real mode DOS programs.  However, any
1169	  recent version of DOSEMU, X, or vbetool should be fully
1170	  functional even without kernel VM86 support, as they will all
1171	  fall back to software emulation. Nevertheless, if you are using
1172	  a 16-bit DOS program where 16-bit performance matters, vm86
1173	  mode might be faster than emulation and you might want to
1174	  enable this option.
1175
1176	  Note that any app that works on a 64-bit kernel is unlikely to
1177	  need this option, as 64-bit kernels don't, and can't, support
1178	  V8086 mode. This option is also unrelated to 16-bit protected
1179	  mode and is not needed to run most 16-bit programs under Wine.
1180
1181	  Enabling this option increases the complexity of the kernel
1182	  and slows down exception handling a tiny bit.
1183
1184	  If unsure, say N here.
1185
1186config VM86
1187	bool
1188	default X86_LEGACY_VM86
1189
1190config X86_16BIT
1191	bool "Enable support for 16-bit segments" if EXPERT
1192	default y
1193	depends on MODIFY_LDT_SYSCALL
1194	help
1195	  This option is required by programs like Wine to run 16-bit
1196	  protected mode legacy code on x86 processors.  Disabling
1197	  this option saves about 300 bytes on i386, or around 6K text
1198	  plus 16K runtime memory on x86-64,
1199
1200config X86_ESPFIX32
1201	def_bool y
1202	depends on X86_16BIT && X86_32
1203
1204config X86_ESPFIX64
1205	def_bool y
1206	depends on X86_16BIT && X86_64
1207
1208config X86_VSYSCALL_EMULATION
1209	bool "Enable vsyscall emulation" if EXPERT
1210	default y
1211	depends on X86_64
1212	help
1213	 This enables emulation of the legacy vsyscall page.  Disabling
1214	 it is roughly equivalent to booting with vsyscall=none, except
1215	 that it will also disable the helpful warning if a program
1216	 tries to use a vsyscall.  With this option set to N, offending
1217	 programs will just segfault, citing addresses of the form
1218	 0xffffffffff600?00.
1219
1220	 This option is required by many programs built before 2013, and
1221	 care should be used even with newer programs if set to N.
1222
1223	 Disabling this option saves about 7K of kernel size and
1224	 possibly 4K of additional runtime pagetable memory.
1225
1226config X86_IOPL_IOPERM
1227	bool "IOPERM and IOPL Emulation"
1228	default y
1229	help
1230	  This enables the ioperm() and iopl() syscalls which are necessary
1231	  for legacy applications.
1232
1233	  Legacy IOPL support is an overbroad mechanism which allows user
1234	  space aside of accessing all 65536 I/O ports also to disable
1235	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1236	  capabilities and permission from potentially active security
1237	  modules.
1238
1239	  The emulation restricts the functionality of the syscall to
1240	  only allowing the full range I/O port access, but prevents the
1241	  ability to disable interrupts from user space which would be
1242	  granted if the hardware IOPL mechanism would be used.
1243
1244config TOSHIBA
1245	tristate "Toshiba Laptop support"
1246	depends on X86_32
1247	help
1248	  This adds a driver to safely access the System Management Mode of
1249	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1250	  not work on models with a Phoenix BIOS. The System Management Mode
1251	  is used to set the BIOS and power saving options on Toshiba portables.
1252
1253	  For information on utilities to make use of this driver see the
1254	  Toshiba Linux utilities web site at:
1255	  <http://www.buzzard.org.uk/toshiba/>.
1256
1257	  Say Y if you intend to run this kernel on a Toshiba portable.
1258	  Say N otherwise.
1259
1260config I8K
1261	tristate "Dell i8k legacy laptop support"
1262	select HWMON
1263	select SENSORS_DELL_SMM
1264	help
1265	  This option enables legacy /proc/i8k userspace interface in hwmon
1266	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1267	  temperature and allows controlling fan speeds of Dell laptops via
1268	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1269	  it reports also power and hotkey status. For fan speed control is
1270	  needed userspace package i8kutils.
1271
1272	  Say Y if you intend to run this kernel on old Dell laptops or want to
1273	  use userspace package i8kutils.
1274	  Say N otherwise.
1275
1276config X86_REBOOTFIXUPS
1277	bool "Enable X86 board specific fixups for reboot"
1278	depends on X86_32
1279	help
1280	  This enables chipset and/or board specific fixups to be done
1281	  in order to get reboot to work correctly. This is only needed on
1282	  some combinations of hardware and BIOS. The symptom, for which
1283	  this config is intended, is when reboot ends with a stalled/hung
1284	  system.
1285
1286	  Currently, the only fixup is for the Geode machines using
1287	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1288
1289	  Say Y if you want to enable the fixup. Currently, it's safe to
1290	  enable this option even if you don't need it.
1291	  Say N otherwise.
1292
1293config MICROCODE
1294	bool "CPU microcode loading support"
1295	default y
1296	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1297	help
1298	  If you say Y here, you will be able to update the microcode on
1299	  Intel and AMD processors. The Intel support is for the IA32 family,
1300	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1301	  AMD support is for families 0x10 and later. You will obviously need
1302	  the actual microcode binary data itself which is not shipped with
1303	  the Linux kernel.
1304
1305	  The preferred method to load microcode from a detached initrd is described
1306	  in Documentation/x86/microcode.rst. For that you need to enable
1307	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1308	  initrd for microcode blobs.
1309
1310	  In addition, you can build the microcode into the kernel. For that you
1311	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1312	  config option.
1313
1314config MICROCODE_INTEL
1315	bool "Intel microcode loading support"
1316	depends on MICROCODE
1317	default MICROCODE
1318	help
1319	  This options enables microcode patch loading support for Intel
1320	  processors.
1321
1322	  For the current Intel microcode data package go to
1323	  <https://downloadcenter.intel.com> and search for
1324	  'Linux Processor Microcode Data File'.
1325
1326config MICROCODE_AMD
1327	bool "AMD microcode loading support"
1328	depends on MICROCODE
1329	help
1330	  If you select this option, microcode patch loading support for AMD
1331	  processors will be enabled.
1332
1333config MICROCODE_OLD_INTERFACE
1334	bool "Ancient loading interface (DEPRECATED)"
1335	default n
1336	depends on MICROCODE
1337	help
1338	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1339	  which was used by userspace tools like iucode_tool and microcode.ctl.
1340	  It is inadequate because it runs too late to be able to properly
1341	  load microcode on a machine and it needs special tools. Instead, you
1342	  should've switched to the early loading method with the initrd or
1343	  builtin microcode by now: Documentation/x86/microcode.rst
1344
1345config X86_MSR
1346	tristate "/dev/cpu/*/msr - Model-specific register support"
1347	help
1348	  This device gives privileged processes access to the x86
1349	  Model-Specific Registers (MSRs).  It is a character device with
1350	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1351	  MSR accesses are directed to a specific CPU on multi-processor
1352	  systems.
1353
1354config X86_CPUID
1355	tristate "/dev/cpu/*/cpuid - CPU information support"
1356	help
1357	  This device gives processes access to the x86 CPUID instruction to
1358	  be executed on a specific processor.  It is a character device
1359	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1360	  /dev/cpu/31/cpuid.
1361
1362choice
1363	prompt "High Memory Support"
1364	default HIGHMEM4G
1365	depends on X86_32
1366
1367config NOHIGHMEM
1368	bool "off"
1369	help
1370	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1371	  However, the address space of 32-bit x86 processors is only 4
1372	  Gigabytes large. That means that, if you have a large amount of
1373	  physical memory, not all of it can be "permanently mapped" by the
1374	  kernel. The physical memory that's not permanently mapped is called
1375	  "high memory".
1376
1377	  If you are compiling a kernel which will never run on a machine with
1378	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1379	  choice and suitable for most users). This will result in a "3GB/1GB"
1380	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1381	  space and the remaining part of the 4GB virtual memory space is used
1382	  by the kernel to permanently map as much physical memory as
1383	  possible.
1384
1385	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1386	  answer "4GB" here.
1387
1388	  If more than 4 Gigabytes is used then answer "64GB" here. This
1389	  selection turns Intel PAE (Physical Address Extension) mode on.
1390	  PAE implements 3-level paging on IA32 processors. PAE is fully
1391	  supported by Linux, PAE mode is implemented on all recent Intel
1392	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1393	  then the kernel will not boot on CPUs that don't support PAE!
1394
1395	  The actual amount of total physical memory will either be
1396	  auto detected or can be forced by using a kernel command line option
1397	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1398	  your boot loader (lilo or loadlin) about how to pass options to the
1399	  kernel at boot time.)
1400
1401	  If unsure, say "off".
1402
1403config HIGHMEM4G
1404	bool "4GB"
1405	help
1406	  Select this if you have a 32-bit processor and between 1 and 4
1407	  gigabytes of physical RAM.
1408
1409config HIGHMEM64G
1410	bool "64GB"
1411	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1412	select X86_PAE
1413	help
1414	  Select this if you have a 32-bit processor and more than 4
1415	  gigabytes of physical RAM.
1416
1417endchoice
1418
1419choice
1420	prompt "Memory split" if EXPERT
1421	default VMSPLIT_3G
1422	depends on X86_32
1423	help
1424	  Select the desired split between kernel and user memory.
1425
1426	  If the address range available to the kernel is less than the
1427	  physical memory installed, the remaining memory will be available
1428	  as "high memory". Accessing high memory is a little more costly
1429	  than low memory, as it needs to be mapped into the kernel first.
1430	  Note that increasing the kernel address space limits the range
1431	  available to user programs, making the address space there
1432	  tighter.  Selecting anything other than the default 3G/1G split
1433	  will also likely make your kernel incompatible with binary-only
1434	  kernel modules.
1435
1436	  If you are not absolutely sure what you are doing, leave this
1437	  option alone!
1438
1439	config VMSPLIT_3G
1440		bool "3G/1G user/kernel split"
1441	config VMSPLIT_3G_OPT
1442		depends on !X86_PAE
1443		bool "3G/1G user/kernel split (for full 1G low memory)"
1444	config VMSPLIT_2G
1445		bool "2G/2G user/kernel split"
1446	config VMSPLIT_2G_OPT
1447		depends on !X86_PAE
1448		bool "2G/2G user/kernel split (for full 2G low memory)"
1449	config VMSPLIT_1G
1450		bool "1G/3G user/kernel split"
1451endchoice
1452
1453config PAGE_OFFSET
1454	hex
1455	default 0xB0000000 if VMSPLIT_3G_OPT
1456	default 0x80000000 if VMSPLIT_2G
1457	default 0x78000000 if VMSPLIT_2G_OPT
1458	default 0x40000000 if VMSPLIT_1G
1459	default 0xC0000000
1460	depends on X86_32
1461
1462config HIGHMEM
1463	def_bool y
1464	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1465
1466config X86_PAE
1467	bool "PAE (Physical Address Extension) Support"
1468	depends on X86_32 && !HIGHMEM4G
1469	select PHYS_ADDR_T_64BIT
1470	select SWIOTLB
1471	help
1472	  PAE is required for NX support, and furthermore enables
1473	  larger swapspace support for non-overcommit purposes. It
1474	  has the cost of more pagetable lookup overhead, and also
1475	  consumes more pagetable space per process.
1476
1477config X86_5LEVEL
1478	bool "Enable 5-level page tables support"
1479	default y
1480	select DYNAMIC_MEMORY_LAYOUT
1481	select SPARSEMEM_VMEMMAP
1482	depends on X86_64
1483	help
1484	  5-level paging enables access to larger address space:
1485	  upto 128 PiB of virtual address space and 4 PiB of
1486	  physical address space.
1487
1488	  It will be supported by future Intel CPUs.
1489
1490	  A kernel with the option enabled can be booted on machines that
1491	  support 4- or 5-level paging.
1492
1493	  See Documentation/x86/x86_64/5level-paging.rst for more
1494	  information.
1495
1496	  Say N if unsure.
1497
1498config X86_DIRECT_GBPAGES
1499	def_bool y
1500	depends on X86_64
1501	help
1502	  Certain kernel features effectively disable kernel
1503	  linear 1 GB mappings (even if the CPU otherwise
1504	  supports them), so don't confuse the user by printing
1505	  that we have them enabled.
1506
1507config X86_CPA_STATISTICS
1508	bool "Enable statistic for Change Page Attribute"
1509	depends on DEBUG_FS
1510	help
1511	  Expose statistics about the Change Page Attribute mechanism, which
1512	  helps to determine the effectiveness of preserving large and huge
1513	  page mappings when mapping protections are changed.
1514
1515config AMD_MEM_ENCRYPT
1516	bool "AMD Secure Memory Encryption (SME) support"
1517	depends on X86_64 && CPU_SUP_AMD
1518	select DMA_COHERENT_POOL
1519	select DYNAMIC_PHYSICAL_MASK
1520	select ARCH_USE_MEMREMAP_PROT
1521	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1522	help
1523	  Say yes to enable support for the encryption of system memory.
1524	  This requires an AMD processor that supports Secure Memory
1525	  Encryption (SME).
1526
1527config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1528	bool "Activate AMD Secure Memory Encryption (SME) by default"
1529	default y
1530	depends on AMD_MEM_ENCRYPT
1531	help
1532	  Say yes to have system memory encrypted by default if running on
1533	  an AMD processor that supports Secure Memory Encryption (SME).
1534
1535	  If set to Y, then the encryption of system memory can be
1536	  deactivated with the mem_encrypt=off command line option.
1537
1538	  If set to N, then the encryption of system memory can be
1539	  activated with the mem_encrypt=on command line option.
1540
1541# Common NUMA Features
1542config NUMA
1543	bool "NUMA Memory Allocation and Scheduler Support"
1544	depends on SMP
1545	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1546	default y if X86_BIGSMP
1547	help
1548	  Enable NUMA (Non-Uniform Memory Access) support.
1549
1550	  The kernel will try to allocate memory used by a CPU on the
1551	  local memory controller of the CPU and add some more
1552	  NUMA awareness to the kernel.
1553
1554	  For 64-bit this is recommended if the system is Intel Core i7
1555	  (or later), AMD Opteron, or EM64T NUMA.
1556
1557	  For 32-bit this is only needed if you boot a 32-bit
1558	  kernel on a 64-bit NUMA platform.
1559
1560	  Otherwise, you should say N.
1561
1562config AMD_NUMA
1563	def_bool y
1564	prompt "Old style AMD Opteron NUMA detection"
1565	depends on X86_64 && NUMA && PCI
1566	help
1567	  Enable AMD NUMA node topology detection.  You should say Y here if
1568	  you have a multi processor AMD system. This uses an old method to
1569	  read the NUMA configuration directly from the builtin Northbridge
1570	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1571	  which also takes priority if both are compiled in.
1572
1573config X86_64_ACPI_NUMA
1574	def_bool y
1575	prompt "ACPI NUMA detection"
1576	depends on X86_64 && NUMA && ACPI && PCI
1577	select ACPI_NUMA
1578	help
1579	  Enable ACPI SRAT based node topology detection.
1580
1581config NUMA_EMU
1582	bool "NUMA emulation"
1583	depends on NUMA
1584	help
1585	  Enable NUMA emulation. A flat machine will be split
1586	  into virtual nodes when booted with "numa=fake=N", where N is the
1587	  number of nodes. This is only useful for debugging.
1588
1589config NODES_SHIFT
1590	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1591	range 1 10
1592	default "10" if MAXSMP
1593	default "6" if X86_64
1594	default "3"
1595	depends on NEED_MULTIPLE_NODES
1596	help
1597	  Specify the maximum number of NUMA Nodes available on the target
1598	  system.  Increases memory reserved to accommodate various tables.
1599
1600config ARCH_FLATMEM_ENABLE
1601	def_bool y
1602	depends on X86_32 && !NUMA
1603
1604config ARCH_SPARSEMEM_ENABLE
1605	def_bool y
1606	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1607	select SPARSEMEM_STATIC if X86_32
1608	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1609
1610config ARCH_SPARSEMEM_DEFAULT
1611	def_bool X86_64 || (NUMA && X86_32)
1612
1613config ARCH_SELECT_MEMORY_MODEL
1614	def_bool y
1615	depends on ARCH_SPARSEMEM_ENABLE
1616
1617config ARCH_MEMORY_PROBE
1618	bool "Enable sysfs memory/probe interface"
1619	depends on X86_64 && MEMORY_HOTPLUG
1620	help
1621	  This option enables a sysfs memory/probe interface for testing.
1622	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1623	  If you are unsure how to answer this question, answer N.
1624
1625config ARCH_PROC_KCORE_TEXT
1626	def_bool y
1627	depends on X86_64 && PROC_KCORE
1628
1629config ILLEGAL_POINTER_VALUE
1630	hex
1631	default 0 if X86_32
1632	default 0xdead000000000000 if X86_64
1633
1634config X86_PMEM_LEGACY_DEVICE
1635	bool
1636
1637config X86_PMEM_LEGACY
1638	tristate "Support non-standard NVDIMMs and ADR protected memory"
1639	depends on PHYS_ADDR_T_64BIT
1640	depends on BLK_DEV
1641	select X86_PMEM_LEGACY_DEVICE
1642	select NUMA_KEEP_MEMINFO if NUMA
1643	select LIBNVDIMM
1644	help
1645	  Treat memory marked using the non-standard e820 type of 12 as used
1646	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1647	  The kernel will offer these regions to the 'pmem' driver so
1648	  they can be used for persistent storage.
1649
1650	  Say Y if unsure.
1651
1652config HIGHPTE
1653	bool "Allocate 3rd-level pagetables from highmem"
1654	depends on HIGHMEM
1655	help
1656	  The VM uses one page table entry for each page of physical memory.
1657	  For systems with a lot of RAM, this can be wasteful of precious
1658	  low memory.  Setting this option will put user-space page table
1659	  entries in high memory.
1660
1661config X86_CHECK_BIOS_CORRUPTION
1662	bool "Check for low memory corruption"
1663	help
1664	  Periodically check for memory corruption in low memory, which
1665	  is suspected to be caused by BIOS.  Even when enabled in the
1666	  configuration, it is disabled at runtime.  Enable it by
1667	  setting "memory_corruption_check=1" on the kernel command
1668	  line.  By default it scans the low 64k of memory every 60
1669	  seconds; see the memory_corruption_check_size and
1670	  memory_corruption_check_period parameters in
1671	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1672
1673	  When enabled with the default parameters, this option has
1674	  almost no overhead, as it reserves a relatively small amount
1675	  of memory and scans it infrequently.  It both detects corruption
1676	  and prevents it from affecting the running system.
1677
1678	  It is, however, intended as a diagnostic tool; if repeatable
1679	  BIOS-originated corruption always affects the same memory,
1680	  you can use memmap= to prevent the kernel from using that
1681	  memory.
1682
1683config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1684	bool "Set the default setting of memory_corruption_check"
1685	depends on X86_CHECK_BIOS_CORRUPTION
1686	default y
1687	help
1688	  Set whether the default state of memory_corruption_check is
1689	  on or off.
1690
1691config X86_RESERVE_LOW
1692	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1693	default 64
1694	range 4 640
1695	help
1696	  Specify the amount of low memory to reserve for the BIOS.
1697
1698	  The first page contains BIOS data structures that the kernel
1699	  must not use, so that page must always be reserved.
1700
1701	  By default we reserve the first 64K of physical RAM, as a
1702	  number of BIOSes are known to corrupt that memory range
1703	  during events such as suspend/resume or monitor cable
1704	  insertion, so it must not be used by the kernel.
1705
1706	  You can set this to 4 if you are absolutely sure that you
1707	  trust the BIOS to get all its memory reservations and usages
1708	  right.  If you know your BIOS have problems beyond the
1709	  default 64K area, you can set this to 640 to avoid using the
1710	  entire low memory range.
1711
1712	  If you have doubts about the BIOS (e.g. suspend/resume does
1713	  not work or there's kernel crashes after certain hardware
1714	  hotplug events) then you might want to enable
1715	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1716	  typical corruption patterns.
1717
1718	  Leave this to the default value of 64 if you are unsure.
1719
1720config MATH_EMULATION
1721	bool
1722	depends on MODIFY_LDT_SYSCALL
1723	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1724	help
1725	  Linux can emulate a math coprocessor (used for floating point
1726	  operations) if you don't have one. 486DX and Pentium processors have
1727	  a math coprocessor built in, 486SX and 386 do not, unless you added
1728	  a 487DX or 387, respectively. (The messages during boot time can
1729	  give you some hints here ["man dmesg"].) Everyone needs either a
1730	  coprocessor or this emulation.
1731
1732	  If you don't have a math coprocessor, you need to say Y here; if you
1733	  say Y here even though you have a coprocessor, the coprocessor will
1734	  be used nevertheless. (This behavior can be changed with the kernel
1735	  command line option "no387", which comes handy if your coprocessor
1736	  is broken. Try "man bootparam" or see the documentation of your boot
1737	  loader (lilo or loadlin) about how to pass options to the kernel at
1738	  boot time.) This means that it is a good idea to say Y here if you
1739	  intend to use this kernel on different machines.
1740
1741	  More information about the internals of the Linux math coprocessor
1742	  emulation can be found in <file:arch/x86/math-emu/README>.
1743
1744	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1745	  kernel, it won't hurt.
1746
1747config MTRR
1748	def_bool y
1749	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1750	help
1751	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1752	  the Memory Type Range Registers (MTRRs) may be used to control
1753	  processor access to memory ranges. This is most useful if you have
1754	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1755	  allows bus write transfers to be combined into a larger transfer
1756	  before bursting over the PCI/AGP bus. This can increase performance
1757	  of image write operations 2.5 times or more. Saying Y here creates a
1758	  /proc/mtrr file which may be used to manipulate your processor's
1759	  MTRRs. Typically the X server should use this.
1760
1761	  This code has a reasonably generic interface so that similar
1762	  control registers on other processors can be easily supported
1763	  as well:
1764
1765	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1766	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1767	  these, the ARRs are used to emulate the MTRRs.
1768	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1769	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1770	  write-combining. All of these processors are supported by this code
1771	  and it makes sense to say Y here if you have one of them.
1772
1773	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1774	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1775	  can lead to all sorts of problems, so it's good to say Y here.
1776
1777	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1778	  just add about 9 KB to your kernel.
1779
1780	  See <file:Documentation/x86/mtrr.rst> for more information.
1781
1782config MTRR_SANITIZER
1783	def_bool y
1784	prompt "MTRR cleanup support"
1785	depends on MTRR
1786	help
1787	  Convert MTRR layout from continuous to discrete, so X drivers can
1788	  add writeback entries.
1789
1790	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1791	  The largest mtrr entry size for a continuous block can be set with
1792	  mtrr_chunk_size.
1793
1794	  If unsure, say Y.
1795
1796config MTRR_SANITIZER_ENABLE_DEFAULT
1797	int "MTRR cleanup enable value (0-1)"
1798	range 0 1
1799	default "0"
1800	depends on MTRR_SANITIZER
1801	help
1802	  Enable mtrr cleanup default value
1803
1804config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1805	int "MTRR cleanup spare reg num (0-7)"
1806	range 0 7
1807	default "1"
1808	depends on MTRR_SANITIZER
1809	help
1810	  mtrr cleanup spare entries default, it can be changed via
1811	  mtrr_spare_reg_nr=N on the kernel command line.
1812
1813config X86_PAT
1814	def_bool y
1815	prompt "x86 PAT support" if EXPERT
1816	depends on MTRR
1817	help
1818	  Use PAT attributes to setup page level cache control.
1819
1820	  PATs are the modern equivalents of MTRRs and are much more
1821	  flexible than MTRRs.
1822
1823	  Say N here if you see bootup problems (boot crash, boot hang,
1824	  spontaneous reboots) or a non-working video driver.
1825
1826	  If unsure, say Y.
1827
1828config ARCH_USES_PG_UNCACHED
1829	def_bool y
1830	depends on X86_PAT
1831
1832config ARCH_RANDOM
1833	def_bool y
1834	prompt "x86 architectural random number generator" if EXPERT
1835	help
1836	  Enable the x86 architectural RDRAND instruction
1837	  (Intel Bull Mountain technology) to generate random numbers.
1838	  If supported, this is a high bandwidth, cryptographically
1839	  secure hardware random number generator.
1840
1841config X86_SMAP
1842	def_bool y
1843	prompt "Supervisor Mode Access Prevention" if EXPERT
1844	help
1845	  Supervisor Mode Access Prevention (SMAP) is a security
1846	  feature in newer Intel processors.  There is a small
1847	  performance cost if this enabled and turned on; there is
1848	  also a small increase in the kernel size if this is enabled.
1849
1850	  If unsure, say Y.
1851
1852config X86_UMIP
1853	def_bool y
1854	prompt "User Mode Instruction Prevention" if EXPERT
1855	help
1856	  User Mode Instruction Prevention (UMIP) is a security feature in
1857	  some x86 processors. If enabled, a general protection fault is
1858	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1859	  executed in user mode. These instructions unnecessarily expose
1860	  information about the hardware state.
1861
1862	  The vast majority of applications do not use these instructions.
1863	  For the very few that do, software emulation is provided in
1864	  specific cases in protected and virtual-8086 modes. Emulated
1865	  results are dummy.
1866
1867config X86_INTEL_MEMORY_PROTECTION_KEYS
1868	prompt "Memory Protection Keys"
1869	def_bool y
1870	# Note: only available in 64-bit mode
1871	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1872	select ARCH_USES_HIGH_VMA_FLAGS
1873	select ARCH_HAS_PKEYS
1874	help
1875	  Memory Protection Keys provides a mechanism for enforcing
1876	  page-based protections, but without requiring modification of the
1877	  page tables when an application changes protection domains.
1878
1879	  For details, see Documentation/core-api/protection-keys.rst
1880
1881	  If unsure, say y.
1882
1883choice
1884	prompt "TSX enable mode"
1885	depends on CPU_SUP_INTEL
1886	default X86_INTEL_TSX_MODE_OFF
1887	help
1888	  Intel's TSX (Transactional Synchronization Extensions) feature
1889	  allows to optimize locking protocols through lock elision which
1890	  can lead to a noticeable performance boost.
1891
1892	  On the other hand it has been shown that TSX can be exploited
1893	  to form side channel attacks (e.g. TAA) and chances are there
1894	  will be more of those attacks discovered in the future.
1895
1896	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1897	  might override this decision by tsx=on the command line parameter.
1898	  Even with TSX enabled, the kernel will attempt to enable the best
1899	  possible TAA mitigation setting depending on the microcode available
1900	  for the particular machine.
1901
1902	  This option allows to set the default tsx mode between tsx=on, =off
1903	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1904	  details.
1905
1906	  Say off if not sure, auto if TSX is in use but it should be used on safe
1907	  platforms or on if TSX is in use and the security aspect of tsx is not
1908	  relevant.
1909
1910config X86_INTEL_TSX_MODE_OFF
1911	bool "off"
1912	help
1913	  TSX is disabled if possible - equals to tsx=off command line parameter.
1914
1915config X86_INTEL_TSX_MODE_ON
1916	bool "on"
1917	help
1918	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1919	  line parameter.
1920
1921config X86_INTEL_TSX_MODE_AUTO
1922	bool "auto"
1923	help
1924	  TSX is enabled on TSX capable HW that is believed to be safe against
1925	  side channel attacks- equals the tsx=auto command line parameter.
1926endchoice
1927
1928config EFI
1929	bool "EFI runtime service support"
1930	depends on ACPI
1931	select UCS2_STRING
1932	select EFI_RUNTIME_WRAPPERS
1933	help
1934	  This enables the kernel to use EFI runtime services that are
1935	  available (such as the EFI variable services).
1936
1937	  This option is only useful on systems that have EFI firmware.
1938	  In addition, you should use the latest ELILO loader available
1939	  at <http://elilo.sourceforge.net> in order to take advantage
1940	  of EFI runtime services. However, even with this option, the
1941	  resultant kernel should continue to boot on existing non-EFI
1942	  platforms.
1943
1944config EFI_STUB
1945	bool "EFI stub support"
1946	depends on EFI && !X86_USE_3DNOW
1947	depends on $(cc-option,-mabi=ms) || X86_32
1948	select RELOCATABLE
1949	help
1950	  This kernel feature allows a bzImage to be loaded directly
1951	  by EFI firmware without the use of a bootloader.
1952
1953	  See Documentation/admin-guide/efi-stub.rst for more information.
1954
1955config EFI_MIXED
1956	bool "EFI mixed-mode support"
1957	depends on EFI_STUB && X86_64
1958	help
1959	   Enabling this feature allows a 64-bit kernel to be booted
1960	   on a 32-bit firmware, provided that your CPU supports 64-bit
1961	   mode.
1962
1963	   Note that it is not possible to boot a mixed-mode enabled
1964	   kernel via the EFI boot stub - a bootloader that supports
1965	   the EFI handover protocol must be used.
1966
1967	   If unsure, say N.
1968
1969config SECCOMP
1970	def_bool y
1971	prompt "Enable seccomp to safely compute untrusted bytecode"
1972	help
1973	  This kernel feature is useful for number crunching applications
1974	  that may need to compute untrusted bytecode during their
1975	  execution. By using pipes or other transports made available to
1976	  the process as file descriptors supporting the read/write
1977	  syscalls, it's possible to isolate those applications in
1978	  their own address space using seccomp. Once seccomp is
1979	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1980	  and the task is only allowed to execute a few safe syscalls
1981	  defined by each seccomp mode.
1982
1983	  If unsure, say Y. Only embedded should say N here.
1984
1985source "kernel/Kconfig.hz"
1986
1987config KEXEC
1988	bool "kexec system call"
1989	select KEXEC_CORE
1990	help
1991	  kexec is a system call that implements the ability to shutdown your
1992	  current kernel, and to start another kernel.  It is like a reboot
1993	  but it is independent of the system firmware.   And like a reboot
1994	  you can start any kernel with it, not just Linux.
1995
1996	  The name comes from the similarity to the exec system call.
1997
1998	  It is an ongoing process to be certain the hardware in a machine
1999	  is properly shutdown, so do not be surprised if this code does not
2000	  initially work for you.  As of this writing the exact hardware
2001	  interface is strongly in flux, so no good recommendation can be
2002	  made.
2003
2004config KEXEC_FILE
2005	bool "kexec file based system call"
2006	select KEXEC_CORE
2007	select BUILD_BIN2C
2008	depends on X86_64
2009	depends on CRYPTO=y
2010	depends on CRYPTO_SHA256=y
2011	help
2012	  This is new version of kexec system call. This system call is
2013	  file based and takes file descriptors as system call argument
2014	  for kernel and initramfs as opposed to list of segments as
2015	  accepted by previous system call.
2016
2017config ARCH_HAS_KEXEC_PURGATORY
2018	def_bool KEXEC_FILE
2019
2020config KEXEC_SIG
2021	bool "Verify kernel signature during kexec_file_load() syscall"
2022	depends on KEXEC_FILE
2023	help
2024
2025	  This option makes the kexec_file_load() syscall check for a valid
2026	  signature of the kernel image.  The image can still be loaded without
2027	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2028	  there's a signature that we can check, then it must be valid.
2029
2030	  In addition to this option, you need to enable signature
2031	  verification for the corresponding kernel image type being
2032	  loaded in order for this to work.
2033
2034config KEXEC_SIG_FORCE
2035	bool "Require a valid signature in kexec_file_load() syscall"
2036	depends on KEXEC_SIG
2037	help
2038	  This option makes kernel signature verification mandatory for
2039	  the kexec_file_load() syscall.
2040
2041config KEXEC_BZIMAGE_VERIFY_SIG
2042	bool "Enable bzImage signature verification support"
2043	depends on KEXEC_SIG
2044	depends on SIGNED_PE_FILE_VERIFICATION
2045	select SYSTEM_TRUSTED_KEYRING
2046	help
2047	  Enable bzImage signature verification support.
2048
2049config CRASH_DUMP
2050	bool "kernel crash dumps"
2051	depends on X86_64 || (X86_32 && HIGHMEM)
2052	help
2053	  Generate crash dump after being started by kexec.
2054	  This should be normally only set in special crash dump kernels
2055	  which are loaded in the main kernel with kexec-tools into
2056	  a specially reserved region and then later executed after
2057	  a crash by kdump/kexec. The crash dump kernel must be compiled
2058	  to a memory address not used by the main kernel or BIOS using
2059	  PHYSICAL_START, or it must be built as a relocatable image
2060	  (CONFIG_RELOCATABLE=y).
2061	  For more details see Documentation/admin-guide/kdump/kdump.rst
2062
2063config KEXEC_JUMP
2064	bool "kexec jump"
2065	depends on KEXEC && HIBERNATION
2066	help
2067	  Jump between original kernel and kexeced kernel and invoke
2068	  code in physical address mode via KEXEC
2069
2070config PHYSICAL_START
2071	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2072	default "0x1000000"
2073	help
2074	  This gives the physical address where the kernel is loaded.
2075
2076	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2077	  bzImage will decompress itself to above physical address and
2078	  run from there. Otherwise, bzImage will run from the address where
2079	  it has been loaded by the boot loader and will ignore above physical
2080	  address.
2081
2082	  In normal kdump cases one does not have to set/change this option
2083	  as now bzImage can be compiled as a completely relocatable image
2084	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2085	  address. This option is mainly useful for the folks who don't want
2086	  to use a bzImage for capturing the crash dump and want to use a
2087	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2088	  to be specifically compiled to run from a specific memory area
2089	  (normally a reserved region) and this option comes handy.
2090
2091	  So if you are using bzImage for capturing the crash dump,
2092	  leave the value here unchanged to 0x1000000 and set
2093	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2094	  for capturing the crash dump change this value to start of
2095	  the reserved region.  In other words, it can be set based on
2096	  the "X" value as specified in the "crashkernel=YM@XM"
2097	  command line boot parameter passed to the panic-ed
2098	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2099	  for more details about crash dumps.
2100
2101	  Usage of bzImage for capturing the crash dump is recommended as
2102	  one does not have to build two kernels. Same kernel can be used
2103	  as production kernel and capture kernel. Above option should have
2104	  gone away after relocatable bzImage support is introduced. But it
2105	  is present because there are users out there who continue to use
2106	  vmlinux for dump capture. This option should go away down the
2107	  line.
2108
2109	  Don't change this unless you know what you are doing.
2110
2111config RELOCATABLE
2112	bool "Build a relocatable kernel"
2113	default y
2114	help
2115	  This builds a kernel image that retains relocation information
2116	  so it can be loaded someplace besides the default 1MB.
2117	  The relocations tend to make the kernel binary about 10% larger,
2118	  but are discarded at runtime.
2119
2120	  One use is for the kexec on panic case where the recovery kernel
2121	  must live at a different physical address than the primary
2122	  kernel.
2123
2124	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2125	  it has been loaded at and the compile time physical address
2126	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2127
2128config RANDOMIZE_BASE
2129	bool "Randomize the address of the kernel image (KASLR)"
2130	depends on RELOCATABLE
2131	default y
2132	help
2133	  In support of Kernel Address Space Layout Randomization (KASLR),
2134	  this randomizes the physical address at which the kernel image
2135	  is decompressed and the virtual address where the kernel
2136	  image is mapped, as a security feature that deters exploit
2137	  attempts relying on knowledge of the location of kernel
2138	  code internals.
2139
2140	  On 64-bit, the kernel physical and virtual addresses are
2141	  randomized separately. The physical address will be anywhere
2142	  between 16MB and the top of physical memory (up to 64TB). The
2143	  virtual address will be randomized from 16MB up to 1GB (9 bits
2144	  of entropy). Note that this also reduces the memory space
2145	  available to kernel modules from 1.5GB to 1GB.
2146
2147	  On 32-bit, the kernel physical and virtual addresses are
2148	  randomized together. They will be randomized from 16MB up to
2149	  512MB (8 bits of entropy).
2150
2151	  Entropy is generated using the RDRAND instruction if it is
2152	  supported. If RDTSC is supported, its value is mixed into
2153	  the entropy pool as well. If neither RDRAND nor RDTSC are
2154	  supported, then entropy is read from the i8254 timer. The
2155	  usable entropy is limited by the kernel being built using
2156	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2157	  minimum of 2MB. As a result, only 10 bits of entropy are
2158	  theoretically possible, but the implementations are further
2159	  limited due to memory layouts.
2160
2161	  If unsure, say Y.
2162
2163# Relocation on x86 needs some additional build support
2164config X86_NEED_RELOCS
2165	def_bool y
2166	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2167
2168config PHYSICAL_ALIGN
2169	hex "Alignment value to which kernel should be aligned"
2170	default "0x200000"
2171	range 0x2000 0x1000000 if X86_32
2172	range 0x200000 0x1000000 if X86_64
2173	help
2174	  This value puts the alignment restrictions on physical address
2175	  where kernel is loaded and run from. Kernel is compiled for an
2176	  address which meets above alignment restriction.
2177
2178	  If bootloader loads the kernel at a non-aligned address and
2179	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2180	  address aligned to above value and run from there.
2181
2182	  If bootloader loads the kernel at a non-aligned address and
2183	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2184	  load address and decompress itself to the address it has been
2185	  compiled for and run from there. The address for which kernel is
2186	  compiled already meets above alignment restrictions. Hence the
2187	  end result is that kernel runs from a physical address meeting
2188	  above alignment restrictions.
2189
2190	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2191	  this value must be a multiple of 0x200000.
2192
2193	  Don't change this unless you know what you are doing.
2194
2195config DYNAMIC_MEMORY_LAYOUT
2196	bool
2197	help
2198	  This option makes base addresses of vmalloc and vmemmap as well as
2199	  __PAGE_OFFSET movable during boot.
2200
2201config RANDOMIZE_MEMORY
2202	bool "Randomize the kernel memory sections"
2203	depends on X86_64
2204	depends on RANDOMIZE_BASE
2205	select DYNAMIC_MEMORY_LAYOUT
2206	default RANDOMIZE_BASE
2207	help
2208	   Randomizes the base virtual address of kernel memory sections
2209	   (physical memory mapping, vmalloc & vmemmap). This security feature
2210	   makes exploits relying on predictable memory locations less reliable.
2211
2212	   The order of allocations remains unchanged. Entropy is generated in
2213	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2214	   configuration have in average 30,000 different possible virtual
2215	   addresses for each memory section.
2216
2217	   If unsure, say Y.
2218
2219config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2220	hex "Physical memory mapping padding" if EXPERT
2221	depends on RANDOMIZE_MEMORY
2222	default "0xa" if MEMORY_HOTPLUG
2223	default "0x0"
2224	range 0x1 0x40 if MEMORY_HOTPLUG
2225	range 0x0 0x40
2226	help
2227	   Define the padding in terabytes added to the existing physical
2228	   memory size during kernel memory randomization. It is useful
2229	   for memory hotplug support but reduces the entropy available for
2230	   address randomization.
2231
2232	   If unsure, leave at the default value.
2233
2234config HOTPLUG_CPU
2235	def_bool y
2236	depends on SMP
2237
2238config BOOTPARAM_HOTPLUG_CPU0
2239	bool "Set default setting of cpu0_hotpluggable"
2240	depends on HOTPLUG_CPU
2241	help
2242	  Set whether default state of cpu0_hotpluggable is on or off.
2243
2244	  Say Y here to enable CPU0 hotplug by default. If this switch
2245	  is turned on, there is no need to give cpu0_hotplug kernel
2246	  parameter and the CPU0 hotplug feature is enabled by default.
2247
2248	  Please note: there are two known CPU0 dependencies if you want
2249	  to enable the CPU0 hotplug feature either by this switch or by
2250	  cpu0_hotplug kernel parameter.
2251
2252	  First, resume from hibernate or suspend always starts from CPU0.
2253	  So hibernate and suspend are prevented if CPU0 is offline.
2254
2255	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2256	  offline if any interrupt can not migrate out of CPU0. There may
2257	  be other CPU0 dependencies.
2258
2259	  Please make sure the dependencies are under your control before
2260	  you enable this feature.
2261
2262	  Say N if you don't want to enable CPU0 hotplug feature by default.
2263	  You still can enable the CPU0 hotplug feature at boot by kernel
2264	  parameter cpu0_hotplug.
2265
2266config DEBUG_HOTPLUG_CPU0
2267	def_bool n
2268	prompt "Debug CPU0 hotplug"
2269	depends on HOTPLUG_CPU
2270	help
2271	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2272	  soon as possible and boots up userspace with CPU0 offlined. User
2273	  can online CPU0 back after boot time.
2274
2275	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2276	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2277	  compilation or giving cpu0_hotplug kernel parameter at boot.
2278
2279	  If unsure, say N.
2280
2281config COMPAT_VDSO
2282	def_bool n
2283	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2284	depends on COMPAT_32
2285	help
2286	  Certain buggy versions of glibc will crash if they are
2287	  presented with a 32-bit vDSO that is not mapped at the address
2288	  indicated in its segment table.
2289
2290	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2291	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2292	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2293	  the only released version with the bug, but OpenSUSE 9
2294	  contains a buggy "glibc 2.3.2".
2295
2296	  The symptom of the bug is that everything crashes on startup, saying:
2297	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2298
2299	  Saying Y here changes the default value of the vdso32 boot
2300	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2301	  This works around the glibc bug but hurts performance.
2302
2303	  If unsure, say N: if you are compiling your own kernel, you
2304	  are unlikely to be using a buggy version of glibc.
2305
2306choice
2307	prompt "vsyscall table for legacy applications"
2308	depends on X86_64
2309	default LEGACY_VSYSCALL_XONLY
2310	help
2311	  Legacy user code that does not know how to find the vDSO expects
2312	  to be able to issue three syscalls by calling fixed addresses in
2313	  kernel space. Since this location is not randomized with ASLR,
2314	  it can be used to assist security vulnerability exploitation.
2315
2316	  This setting can be changed at boot time via the kernel command
2317	  line parameter vsyscall=[emulate|xonly|none].
2318
2319	  On a system with recent enough glibc (2.14 or newer) and no
2320	  static binaries, you can say None without a performance penalty
2321	  to improve security.
2322
2323	  If unsure, select "Emulate execution only".
2324
2325	config LEGACY_VSYSCALL_EMULATE
2326		bool "Full emulation"
2327		help
2328		  The kernel traps and emulates calls into the fixed vsyscall
2329		  address mapping. This makes the mapping non-executable, but
2330		  it still contains readable known contents, which could be
2331		  used in certain rare security vulnerability exploits. This
2332		  configuration is recommended when using legacy userspace
2333		  that still uses vsyscalls along with legacy binary
2334		  instrumentation tools that require code to be readable.
2335
2336		  An example of this type of legacy userspace is running
2337		  Pin on an old binary that still uses vsyscalls.
2338
2339	config LEGACY_VSYSCALL_XONLY
2340		bool "Emulate execution only"
2341		help
2342		  The kernel traps and emulates calls into the fixed vsyscall
2343		  address mapping and does not allow reads.  This
2344		  configuration is recommended when userspace might use the
2345		  legacy vsyscall area but support for legacy binary
2346		  instrumentation of legacy code is not needed.  It mitigates
2347		  certain uses of the vsyscall area as an ASLR-bypassing
2348		  buffer.
2349
2350	config LEGACY_VSYSCALL_NONE
2351		bool "None"
2352		help
2353		  There will be no vsyscall mapping at all. This will
2354		  eliminate any risk of ASLR bypass due to the vsyscall
2355		  fixed address mapping. Attempts to use the vsyscalls
2356		  will be reported to dmesg, so that either old or
2357		  malicious userspace programs can be identified.
2358
2359endchoice
2360
2361config CMDLINE_BOOL
2362	bool "Built-in kernel command line"
2363	help
2364	  Allow for specifying boot arguments to the kernel at
2365	  build time.  On some systems (e.g. embedded ones), it is
2366	  necessary or convenient to provide some or all of the
2367	  kernel boot arguments with the kernel itself (that is,
2368	  to not rely on the boot loader to provide them.)
2369
2370	  To compile command line arguments into the kernel,
2371	  set this option to 'Y', then fill in the
2372	  boot arguments in CONFIG_CMDLINE.
2373
2374	  Systems with fully functional boot loaders (i.e. non-embedded)
2375	  should leave this option set to 'N'.
2376
2377config CMDLINE
2378	string "Built-in kernel command string"
2379	depends on CMDLINE_BOOL
2380	default ""
2381	help
2382	  Enter arguments here that should be compiled into the kernel
2383	  image and used at boot time.  If the boot loader provides a
2384	  command line at boot time, it is appended to this string to
2385	  form the full kernel command line, when the system boots.
2386
2387	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2388	  change this behavior.
2389
2390	  In most cases, the command line (whether built-in or provided
2391	  by the boot loader) should specify the device for the root
2392	  file system.
2393
2394config CMDLINE_OVERRIDE
2395	bool "Built-in command line overrides boot loader arguments"
2396	depends on CMDLINE_BOOL && CMDLINE != ""
2397	help
2398	  Set this option to 'Y' to have the kernel ignore the boot loader
2399	  command line, and use ONLY the built-in command line.
2400
2401	  This is used to work around broken boot loaders.  This should
2402	  be set to 'N' under normal conditions.
2403
2404config MODIFY_LDT_SYSCALL
2405	bool "Enable the LDT (local descriptor table)" if EXPERT
2406	default y
2407	help
2408	  Linux can allow user programs to install a per-process x86
2409	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2410	  call.  This is required to run 16-bit or segmented code such as
2411	  DOSEMU or some Wine programs.  It is also used by some very old
2412	  threading libraries.
2413
2414	  Enabling this feature adds a small amount of overhead to
2415	  context switches and increases the low-level kernel attack
2416	  surface.  Disabling it removes the modify_ldt(2) system call.
2417
2418	  Saying 'N' here may make sense for embedded or server kernels.
2419
2420source "kernel/livepatch/Kconfig"
2421
2422endmenu
2423
2424config ARCH_HAS_ADD_PAGES
2425	def_bool y
2426	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2427
2428config ARCH_ENABLE_MEMORY_HOTPLUG
2429	def_bool y
2430	depends on X86_64 || (X86_32 && HIGHMEM)
2431
2432config ARCH_ENABLE_MEMORY_HOTREMOVE
2433	def_bool y
2434	depends on MEMORY_HOTPLUG
2435
2436config USE_PERCPU_NUMA_NODE_ID
2437	def_bool y
2438	depends on NUMA
2439
2440config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2441	def_bool y
2442	depends on X86_64 || X86_PAE
2443
2444config ARCH_ENABLE_HUGEPAGE_MIGRATION
2445	def_bool y
2446	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2447
2448config ARCH_ENABLE_THP_MIGRATION
2449	def_bool y
2450	depends on X86_64 && TRANSPARENT_HUGEPAGE
2451
2452menu "Power management and ACPI options"
2453
2454config ARCH_HIBERNATION_HEADER
2455	def_bool y
2456	depends on HIBERNATION
2457
2458source "kernel/power/Kconfig"
2459
2460source "drivers/acpi/Kconfig"
2461
2462source "drivers/sfi/Kconfig"
2463
2464config X86_APM_BOOT
2465	def_bool y
2466	depends on APM
2467
2468menuconfig APM
2469	tristate "APM (Advanced Power Management) BIOS support"
2470	depends on X86_32 && PM_SLEEP
2471	help
2472	  APM is a BIOS specification for saving power using several different
2473	  techniques. This is mostly useful for battery powered laptops with
2474	  APM compliant BIOSes. If you say Y here, the system time will be
2475	  reset after a RESUME operation, the /proc/apm device will provide
2476	  battery status information, and user-space programs will receive
2477	  notification of APM "events" (e.g. battery status change).
2478
2479	  If you select "Y" here, you can disable actual use of the APM
2480	  BIOS by passing the "apm=off" option to the kernel at boot time.
2481
2482	  Note that the APM support is almost completely disabled for
2483	  machines with more than one CPU.
2484
2485	  In order to use APM, you will need supporting software. For location
2486	  and more information, read <file:Documentation/power/apm-acpi.rst>
2487	  and the Battery Powered Linux mini-HOWTO, available from
2488	  <http://www.tldp.org/docs.html#howto>.
2489
2490	  This driver does not spin down disk drives (see the hdparm(8)
2491	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2492	  VESA-compliant "green" monitors.
2493
2494	  This driver does not support the TI 4000M TravelMate and the ACER
2495	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2496	  desktop machines also don't have compliant BIOSes, and this driver
2497	  may cause those machines to panic during the boot phase.
2498
2499	  Generally, if you don't have a battery in your machine, there isn't
2500	  much point in using this driver and you should say N. If you get
2501	  random kernel OOPSes or reboots that don't seem to be related to
2502	  anything, try disabling/enabling this option (or disabling/enabling
2503	  APM in your BIOS).
2504
2505	  Some other things you should try when experiencing seemingly random,
2506	  "weird" problems:
2507
2508	  1) make sure that you have enough swap space and that it is
2509	  enabled.
2510	  2) pass the "no-hlt" option to the kernel
2511	  3) switch on floating point emulation in the kernel and pass
2512	  the "no387" option to the kernel
2513	  4) pass the "floppy=nodma" option to the kernel
2514	  5) pass the "mem=4M" option to the kernel (thereby disabling
2515	  all but the first 4 MB of RAM)
2516	  6) make sure that the CPU is not over clocked.
2517	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2518	  8) disable the cache from your BIOS settings
2519	  9) install a fan for the video card or exchange video RAM
2520	  10) install a better fan for the CPU
2521	  11) exchange RAM chips
2522	  12) exchange the motherboard.
2523
2524	  To compile this driver as a module, choose M here: the
2525	  module will be called apm.
2526
2527if APM
2528
2529config APM_IGNORE_USER_SUSPEND
2530	bool "Ignore USER SUSPEND"
2531	help
2532	  This option will ignore USER SUSPEND requests. On machines with a
2533	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2534	  series notebooks, it is necessary to say Y because of a BIOS bug.
2535
2536config APM_DO_ENABLE
2537	bool "Enable PM at boot time"
2538	help
2539	  Enable APM features at boot time. From page 36 of the APM BIOS
2540	  specification: "When disabled, the APM BIOS does not automatically
2541	  power manage devices, enter the Standby State, enter the Suspend
2542	  State, or take power saving steps in response to CPU Idle calls."
2543	  This driver will make CPU Idle calls when Linux is idle (unless this
2544	  feature is turned off -- see "Do CPU IDLE calls", below). This
2545	  should always save battery power, but more complicated APM features
2546	  will be dependent on your BIOS implementation. You may need to turn
2547	  this option off if your computer hangs at boot time when using APM
2548	  support, or if it beeps continuously instead of suspending. Turn
2549	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2550	  T400CDT. This is off by default since most machines do fine without
2551	  this feature.
2552
2553config APM_CPU_IDLE
2554	depends on CPU_IDLE
2555	bool "Make CPU Idle calls when idle"
2556	help
2557	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2558	  On some machines, this can activate improved power savings, such as
2559	  a slowed CPU clock rate, when the machine is idle. These idle calls
2560	  are made after the idle loop has run for some length of time (e.g.,
2561	  333 mS). On some machines, this will cause a hang at boot time or
2562	  whenever the CPU becomes idle. (On machines with more than one CPU,
2563	  this option does nothing.)
2564
2565config APM_DISPLAY_BLANK
2566	bool "Enable console blanking using APM"
2567	help
2568	  Enable console blanking using the APM. Some laptops can use this to
2569	  turn off the LCD backlight when the screen blanker of the Linux
2570	  virtual console blanks the screen. Note that this is only used by
2571	  the virtual console screen blanker, and won't turn off the backlight
2572	  when using the X Window system. This also doesn't have anything to
2573	  do with your VESA-compliant power-saving monitor. Further, this
2574	  option doesn't work for all laptops -- it might not turn off your
2575	  backlight at all, or it might print a lot of errors to the console,
2576	  especially if you are using gpm.
2577
2578config APM_ALLOW_INTS
2579	bool "Allow interrupts during APM BIOS calls"
2580	help
2581	  Normally we disable external interrupts while we are making calls to
2582	  the APM BIOS as a measure to lessen the effects of a badly behaving
2583	  BIOS implementation.  The BIOS should reenable interrupts if it
2584	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2585	  many of the newer IBM Thinkpads.  If you experience hangs when you
2586	  suspend, try setting this to Y.  Otherwise, say N.
2587
2588endif # APM
2589
2590source "drivers/cpufreq/Kconfig"
2591
2592source "drivers/cpuidle/Kconfig"
2593
2594source "drivers/idle/Kconfig"
2595
2596endmenu
2597
2598
2599menu "Bus options (PCI etc.)"
2600
2601choice
2602	prompt "PCI access mode"
2603	depends on X86_32 && PCI
2604	default PCI_GOANY
2605	help
2606	  On PCI systems, the BIOS can be used to detect the PCI devices and
2607	  determine their configuration. However, some old PCI motherboards
2608	  have BIOS bugs and may crash if this is done. Also, some embedded
2609	  PCI-based systems don't have any BIOS at all. Linux can also try to
2610	  detect the PCI hardware directly without using the BIOS.
2611
2612	  With this option, you can specify how Linux should detect the
2613	  PCI devices. If you choose "BIOS", the BIOS will be used,
2614	  if you choose "Direct", the BIOS won't be used, and if you
2615	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2616	  If you choose "Any", the kernel will try MMCONFIG, then the
2617	  direct access method and falls back to the BIOS if that doesn't
2618	  work. If unsure, go with the default, which is "Any".
2619
2620config PCI_GOBIOS
2621	bool "BIOS"
2622
2623config PCI_GOMMCONFIG
2624	bool "MMConfig"
2625
2626config PCI_GODIRECT
2627	bool "Direct"
2628
2629config PCI_GOOLPC
2630	bool "OLPC XO-1"
2631	depends on OLPC
2632
2633config PCI_GOANY
2634	bool "Any"
2635
2636endchoice
2637
2638config PCI_BIOS
2639	def_bool y
2640	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2641
2642# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2643config PCI_DIRECT
2644	def_bool y
2645	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2646
2647config PCI_MMCONFIG
2648	bool "Support mmconfig PCI config space access" if X86_64
2649	default y
2650	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2651	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2652
2653config PCI_OLPC
2654	def_bool y
2655	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2656
2657config PCI_XEN
2658	def_bool y
2659	depends on PCI && XEN
2660	select SWIOTLB_XEN
2661
2662config MMCONF_FAM10H
2663	def_bool y
2664	depends on X86_64 && PCI_MMCONFIG && ACPI
2665
2666config PCI_CNB20LE_QUIRK
2667	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2668	depends on PCI
2669	help
2670	  Read the PCI windows out of the CNB20LE host bridge. This allows
2671	  PCI hotplug to work on systems with the CNB20LE chipset which do
2672	  not have ACPI.
2673
2674	  There's no public spec for this chipset, and this functionality
2675	  is known to be incomplete.
2676
2677	  You should say N unless you know you need this.
2678
2679config ISA_BUS
2680	bool "ISA bus support on modern systems" if EXPERT
2681	help
2682	  Expose ISA bus device drivers and options available for selection and
2683	  configuration. Enable this option if your target machine has an ISA
2684	  bus. ISA is an older system, displaced by PCI and newer bus
2685	  architectures -- if your target machine is modern, it probably does
2686	  not have an ISA bus.
2687
2688	  If unsure, say N.
2689
2690# x86_64 have no ISA slots, but can have ISA-style DMA.
2691config ISA_DMA_API
2692	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2693	default y
2694	help
2695	  Enables ISA-style DMA support for devices requiring such controllers.
2696	  If unsure, say Y.
2697
2698if X86_32
2699
2700config ISA
2701	bool "ISA support"
2702	help
2703	  Find out whether you have ISA slots on your motherboard.  ISA is the
2704	  name of a bus system, i.e. the way the CPU talks to the other stuff
2705	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2706	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2707	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2708
2709config SCx200
2710	tristate "NatSemi SCx200 support"
2711	help
2712	  This provides basic support for National Semiconductor's
2713	  (now AMD's) Geode processors.  The driver probes for the
2714	  PCI-IDs of several on-chip devices, so its a good dependency
2715	  for other scx200_* drivers.
2716
2717	  If compiled as a module, the driver is named scx200.
2718
2719config SCx200HR_TIMER
2720	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2721	depends on SCx200
2722	default y
2723	help
2724	  This driver provides a clocksource built upon the on-chip
2725	  27MHz high-resolution timer.  Its also a workaround for
2726	  NSC Geode SC-1100's buggy TSC, which loses time when the
2727	  processor goes idle (as is done by the scheduler).  The
2728	  other workaround is idle=poll boot option.
2729
2730config OLPC
2731	bool "One Laptop Per Child support"
2732	depends on !X86_PAE
2733	select GPIOLIB
2734	select OF
2735	select OF_PROMTREE
2736	select IRQ_DOMAIN
2737	select OLPC_EC
2738	help
2739	  Add support for detecting the unique features of the OLPC
2740	  XO hardware.
2741
2742config OLPC_XO1_PM
2743	bool "OLPC XO-1 Power Management"
2744	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2745	help
2746	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2747
2748config OLPC_XO1_RTC
2749	bool "OLPC XO-1 Real Time Clock"
2750	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2751	help
2752	  Add support for the XO-1 real time clock, which can be used as a
2753	  programmable wakeup source.
2754
2755config OLPC_XO1_SCI
2756	bool "OLPC XO-1 SCI extras"
2757	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2758	depends on INPUT=y
2759	select POWER_SUPPLY
2760	help
2761	  Add support for SCI-based features of the OLPC XO-1 laptop:
2762	   - EC-driven system wakeups
2763	   - Power button
2764	   - Ebook switch
2765	   - Lid switch
2766	   - AC adapter status updates
2767	   - Battery status updates
2768
2769config OLPC_XO15_SCI
2770	bool "OLPC XO-1.5 SCI extras"
2771	depends on OLPC && ACPI
2772	select POWER_SUPPLY
2773	help
2774	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2775	   - EC-driven system wakeups
2776	   - AC adapter status updates
2777	   - Battery status updates
2778
2779config ALIX
2780	bool "PCEngines ALIX System Support (LED setup)"
2781	select GPIOLIB
2782	help
2783	  This option enables system support for the PCEngines ALIX.
2784	  At present this just sets up LEDs for GPIO control on
2785	  ALIX2/3/6 boards.  However, other system specific setup should
2786	  get added here.
2787
2788	  Note: You must still enable the drivers for GPIO and LED support
2789	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2790
2791	  Note: You have to set alix.force=1 for boards with Award BIOS.
2792
2793config NET5501
2794	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2795	select GPIOLIB
2796	help
2797	  This option enables system support for the Soekris Engineering net5501.
2798
2799config GEOS
2800	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2801	select GPIOLIB
2802	depends on DMI
2803	help
2804	  This option enables system support for the Traverse Technologies GEOS.
2805
2806config TS5500
2807	bool "Technologic Systems TS-5500 platform support"
2808	depends on MELAN
2809	select CHECK_SIGNATURE
2810	select NEW_LEDS
2811	select LEDS_CLASS
2812	help
2813	  This option enables system support for the Technologic Systems TS-5500.
2814
2815endif # X86_32
2816
2817config AMD_NB
2818	def_bool y
2819	depends on CPU_SUP_AMD && PCI
2820
2821config X86_SYSFB
2822	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2823	help
2824	  Firmwares often provide initial graphics framebuffers so the BIOS,
2825	  bootloader or kernel can show basic video-output during boot for
2826	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2827	  Extensions and EFI-framebuffers for this, which are mostly limited
2828	  to x86.
2829	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2830	  framebuffers so the new generic system-framebuffer drivers can be
2831	  used on x86. If the framebuffer is not compatible with the generic
2832	  modes, it is advertised as fallback platform framebuffer so legacy
2833	  drivers like efifb, vesafb and uvesafb can pick it up.
2834	  If this option is not selected, all system framebuffers are always
2835	  marked as fallback platform framebuffers as usual.
2836
2837	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2838	  not be able to pick up generic system framebuffers if this option
2839	  is selected. You are highly encouraged to enable simplefb as
2840	  replacement if you select this option. simplefb can correctly deal
2841	  with generic system framebuffers. But you should still keep vesafb
2842	  and others enabled as fallback if a system framebuffer is
2843	  incompatible with simplefb.
2844
2845	  If unsure, say Y.
2846
2847endmenu
2848
2849
2850menu "Binary Emulations"
2851
2852config IA32_EMULATION
2853	bool "IA32 Emulation"
2854	depends on X86_64
2855	select ARCH_WANT_OLD_COMPAT_IPC
2856	select BINFMT_ELF
2857	select COMPAT_BINFMT_ELF
2858	select COMPAT_OLD_SIGACTION
2859	help
2860	  Include code to run legacy 32-bit programs under a
2861	  64-bit kernel. You should likely turn this on, unless you're
2862	  100% sure that you don't have any 32-bit programs left.
2863
2864config IA32_AOUT
2865	tristate "IA32 a.out support"
2866	depends on IA32_EMULATION
2867	depends on BROKEN
2868	help
2869	  Support old a.out binaries in the 32bit emulation.
2870
2871config X86_X32
2872	bool "x32 ABI for 64-bit mode"
2873	depends on X86_64
2874	help
2875	  Include code to run binaries for the x32 native 32-bit ABI
2876	  for 64-bit processors.  An x32 process gets access to the
2877	  full 64-bit register file and wide data path while leaving
2878	  pointers at 32 bits for smaller memory footprint.
2879
2880	  You will need a recent binutils (2.22 or later) with
2881	  elf32_x86_64 support enabled to compile a kernel with this
2882	  option set.
2883
2884config COMPAT_32
2885	def_bool y
2886	depends on IA32_EMULATION || X86_32
2887	select HAVE_UID16
2888	select OLD_SIGSUSPEND3
2889
2890config COMPAT
2891	def_bool y
2892	depends on IA32_EMULATION || X86_X32
2893
2894if COMPAT
2895config COMPAT_FOR_U64_ALIGNMENT
2896	def_bool y
2897
2898config SYSVIPC_COMPAT
2899	def_bool y
2900	depends on SYSVIPC
2901endif
2902
2903endmenu
2904
2905
2906config HAVE_ATOMIC_IOMAP
2907	def_bool y
2908	depends on X86_32
2909
2910source "drivers/firmware/Kconfig"
2911
2912source "arch/x86/kvm/Kconfig"
2913
2914source "arch/x86/Kconfig.assembler"
2915