xref: /linux/arch/x86/Kconfig (revision f76fbbbb5061fe14824ba5807c44bd7400a6b4e1)
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 GENERIC_VDSO_32
18	select HAVE_DEBUG_STACKOVERFLOW
19	select KMAP_LOCAL
20	select MODULES_USE_ELF_REL
21	select OLD_SIGACTION
22	select ARCH_SPLIT_ARG64
23
24config X86_64
25	def_bool y
26	depends on 64BIT
27	# Options that are inherently 64-bit kernel only:
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30	select ARCH_USE_CMPXCHG_LOCKREF
31	select HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37
38config FORCE_DYNAMIC_FTRACE
39	def_bool y
40	depends on X86_32
41	depends on FUNCTION_TRACER
42	select DYNAMIC_FTRACE
43	help
44	 We keep the static function tracing (!DYNAMIC_FTRACE) around
45	 in order to test the non static function tracing in the
46	 generic code, as other architectures still use it. But we
47	 only need to keep it around for x86_64. No need to keep it
48	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
49#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53#   ported to 32-bit as well. )
54#
55config X86
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
61	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62	select ARCH_32BIT_OFF_T			if X86_32
63	select ARCH_CLOCKSOURCE_INIT
64	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
65	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
66	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
67	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
69	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
70	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71	select ARCH_HAS_CACHE_LINE_SIZE
72	select ARCH_HAS_DEBUG_VIRTUAL
73	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
74	select ARCH_HAS_DEVMEM_IS_ALLOWED
75	select ARCH_HAS_EARLY_DEBUG		if KGDB
76	select ARCH_HAS_ELF_RANDOMIZE
77	select ARCH_HAS_FAST_MULTIPLIER
78	select ARCH_HAS_FILTER_PGPROT
79	select ARCH_HAS_FORTIFY_SOURCE
80	select ARCH_HAS_GCOV_PROFILE_ALL
81	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
82	select ARCH_HAS_MEM_ENCRYPT
83	select ARCH_HAS_MEMBARRIER_SYNC_CORE
84	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85	select ARCH_HAS_PMEM_API		if X86_64
86	select ARCH_HAS_PTE_DEVMAP		if X86_64
87	select ARCH_HAS_PTE_SPECIAL
88	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
89	select ARCH_HAS_COPY_MC			if X86_64
90	select ARCH_HAS_SET_MEMORY
91	select ARCH_HAS_SET_DIRECT_MAP
92	select ARCH_HAS_STRICT_KERNEL_RWX
93	select ARCH_HAS_STRICT_MODULE_RWX
94	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
95	select ARCH_HAS_SYSCALL_WRAPPER
96	select ARCH_HAS_UBSAN_SANITIZE_ALL
97	select ARCH_HAS_DEBUG_WX
98	select ARCH_HAS_ZONE_DMA_SET if EXPERT
99	select ARCH_HAVE_NMI_SAFE_CMPXCHG
100	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
101	select ARCH_MIGHT_HAVE_PC_PARPORT
102	select ARCH_MIGHT_HAVE_PC_SERIO
103	select ARCH_STACKWALK
104	select ARCH_SUPPORTS_ACPI
105	select ARCH_SUPPORTS_ATOMIC_RMW
106	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
107	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
108	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
109	select ARCH_SUPPORTS_LTO_CLANG
110	select ARCH_SUPPORTS_LTO_CLANG_THIN
111	select ARCH_USE_BUILTIN_BSWAP
112	select ARCH_USE_MEMTEST
113	select ARCH_USE_QUEUED_RWLOCKS
114	select ARCH_USE_QUEUED_SPINLOCKS
115	select ARCH_USE_SYM_ANNOTATIONS
116	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
117	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
118	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
119	select ARCH_WANTS_NO_INSTR
120	select ARCH_WANT_HUGE_PMD_SHARE
121	select ARCH_WANT_LD_ORPHAN_WARN
122	select ARCH_WANTS_THP_SWAP		if X86_64
123	select ARCH_HAS_PARANOID_L1D_FLUSH
124	select BUILDTIME_TABLE_SORT
125	select CLKEVT_I8253
126	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
127	select CLOCKSOURCE_WATCHDOG
128	select DCACHE_WORD_ACCESS
129	select EDAC_ATOMIC_SCRUB
130	select EDAC_SUPPORT
131	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
132	select GENERIC_CLOCKEVENTS_MIN_ADJUST
133	select GENERIC_CMOS_UPDATE
134	select GENERIC_CPU_AUTOPROBE
135	select GENERIC_CPU_VULNERABILITIES
136	select GENERIC_EARLY_IOREMAP
137	select GENERIC_ENTRY
138	select GENERIC_FIND_FIRST_BIT
139	select GENERIC_IOMAP
140	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
141	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
142	select GENERIC_IRQ_MIGRATION		if SMP
143	select GENERIC_IRQ_PROBE
144	select GENERIC_IRQ_RESERVATION_MODE
145	select GENERIC_IRQ_SHOW
146	select GENERIC_PENDING_IRQ		if SMP
147	select GENERIC_PTDUMP
148	select GENERIC_SMP_IDLE_THREAD
149	select GENERIC_TIME_VSYSCALL
150	select GENERIC_GETTIMEOFDAY
151	select GENERIC_VDSO_TIME_NS
152	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
153	select HARDIRQS_SW_RESEND
154	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
155	select HAVE_ACPI_APEI			if ACPI
156	select HAVE_ACPI_APEI_NMI		if ACPI
157	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
158	select HAVE_ARCH_AUDITSYSCALL
159	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
160	select HAVE_ARCH_JUMP_LABEL
161	select HAVE_ARCH_JUMP_LABEL_RELATIVE
162	select HAVE_ARCH_KASAN			if X86_64
163	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
164	select HAVE_ARCH_KFENCE
165	select HAVE_ARCH_KGDB
166	select HAVE_ARCH_MMAP_RND_BITS		if MMU
167	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
168	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
169	select HAVE_ARCH_PREL32_RELOCATIONS
170	select HAVE_ARCH_SECCOMP_FILTER
171	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
172	select HAVE_ARCH_STACKLEAK
173	select HAVE_ARCH_TRACEHOOK
174	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
175	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
176	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
177	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
178	select HAVE_ARCH_VMAP_STACK		if X86_64
179	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
180	select HAVE_ARCH_WITHIN_STACK_FRAMES
181	select HAVE_ASM_MODVERSIONS
182	select HAVE_CMPXCHG_DOUBLE
183	select HAVE_CMPXCHG_LOCAL
184	select HAVE_CONTEXT_TRACKING		if X86_64
185	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
186	select HAVE_C_RECORDMCOUNT
187	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
188	select HAVE_DEBUG_KMEMLEAK
189	select HAVE_DMA_CONTIGUOUS
190	select HAVE_DYNAMIC_FTRACE
191	select HAVE_DYNAMIC_FTRACE_WITH_REGS
192	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
193	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
194	select HAVE_EBPF_JIT
195	select HAVE_EFFICIENT_UNALIGNED_ACCESS
196	select HAVE_EISA
197	select HAVE_EXIT_THREAD
198	select HAVE_FAST_GUP
199	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
200	select HAVE_FTRACE_MCOUNT_RECORD
201	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
202	select HAVE_FUNCTION_TRACER
203	select HAVE_GCC_PLUGINS
204	select HAVE_HW_BREAKPOINT
205	select HAVE_IOREMAP_PROT
206	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
207	select HAVE_IRQ_TIME_ACCOUNTING
208	select HAVE_KERNEL_BZIP2
209	select HAVE_KERNEL_GZIP
210	select HAVE_KERNEL_LZ4
211	select HAVE_KERNEL_LZMA
212	select HAVE_KERNEL_LZO
213	select HAVE_KERNEL_XZ
214	select HAVE_KERNEL_ZSTD
215	select HAVE_KPROBES
216	select HAVE_KPROBES_ON_FTRACE
217	select HAVE_FUNCTION_ERROR_INJECTION
218	select HAVE_KRETPROBES
219	select HAVE_KVM
220	select HAVE_LIVEPATCH			if X86_64
221	select HAVE_MIXED_BREAKPOINTS_REGS
222	select HAVE_MOD_ARCH_SPECIFIC
223	select HAVE_MOVE_PMD
224	select HAVE_MOVE_PUD
225	select HAVE_NMI
226	select HAVE_OPTPROBES
227	select HAVE_PCSPKR_PLATFORM
228	select HAVE_PERF_EVENTS
229	select HAVE_PERF_EVENTS_NMI
230	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
231	select HAVE_PCI
232	select HAVE_PERF_REGS
233	select HAVE_PERF_USER_STACK_DUMP
234	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
235	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
236	select HAVE_REGS_AND_STACK_ACCESS_API
237	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
238	select HAVE_FUNCTION_ARG_ACCESS_API
239	select HAVE_SOFTIRQ_ON_OWN_STACK
240	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
241	select HAVE_STACK_VALIDATION		if X86_64
242	select HAVE_STATIC_CALL
243	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
244	select HAVE_PREEMPT_DYNAMIC
245	select HAVE_RSEQ
246	select HAVE_SYSCALL_TRACEPOINTS
247	select HAVE_UNSTABLE_SCHED_CLOCK
248	select HAVE_USER_RETURN_NOTIFIER
249	select HAVE_GENERIC_VDSO
250	select HOTPLUG_SMT			if SMP
251	select IRQ_FORCED_THREADING
252	select NEED_SG_DMA_LENGTH
253	select PCI_DOMAINS			if PCI
254	select PCI_LOCKLESS_CONFIG		if PCI
255	select PERF_EVENTS
256	select RTC_LIB
257	select RTC_MC146818_LIB
258	select SPARSE_IRQ
259	select SRCU
260	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
261	select SYSCTL_EXCEPTION_TRACE
262	select THREAD_INFO_IN_TASK
263	select TRACE_IRQFLAGS_SUPPORT
264	select USER_STACKTRACE_SUPPORT
265	select VIRT_TO_BUS
266	select HAVE_ARCH_KCSAN			if X86_64
267	select X86_FEATURE_NAMES		if PROC_FS
268	select PROC_PID_ARCH_STATUS		if PROC_FS
269	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
270
271config INSTRUCTION_DECODER
272	def_bool y
273	depends on KPROBES || PERF_EVENTS || UPROBES
274
275config OUTPUT_FORMAT
276	string
277	default "elf32-i386" if X86_32
278	default "elf64-x86-64" if X86_64
279
280config LOCKDEP_SUPPORT
281	def_bool y
282
283config STACKTRACE_SUPPORT
284	def_bool y
285
286config MMU
287	def_bool y
288
289config ARCH_MMAP_RND_BITS_MIN
290	default 28 if 64BIT
291	default 8
292
293config ARCH_MMAP_RND_BITS_MAX
294	default 32 if 64BIT
295	default 16
296
297config ARCH_MMAP_RND_COMPAT_BITS_MIN
298	default 8
299
300config ARCH_MMAP_RND_COMPAT_BITS_MAX
301	default 16
302
303config SBUS
304	bool
305
306config GENERIC_ISA_DMA
307	def_bool y
308	depends on ISA_DMA_API
309
310config GENERIC_BUG
311	def_bool y
312	depends on BUG
313	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
314
315config GENERIC_BUG_RELATIVE_POINTERS
316	bool
317
318config ARCH_MAY_HAVE_PC_FDC
319	def_bool y
320	depends on ISA_DMA_API
321
322config GENERIC_CALIBRATE_DELAY
323	def_bool y
324
325config ARCH_HAS_CPU_RELAX
326	def_bool y
327
328config ARCH_HAS_FILTER_PGPROT
329	def_bool y
330
331config HAVE_SETUP_PER_CPU_AREA
332	def_bool y
333
334config NEED_PER_CPU_EMBED_FIRST_CHUNK
335	def_bool y
336
337config NEED_PER_CPU_PAGE_FIRST_CHUNK
338	def_bool y
339
340config ARCH_HIBERNATION_POSSIBLE
341	def_bool y
342
343config ARCH_NR_GPIO
344	int
345	default 1024 if X86_64
346	default 512
347
348config ARCH_SUSPEND_POSSIBLE
349	def_bool y
350
351config ARCH_WANT_GENERAL_HUGETLB
352	def_bool y
353
354config AUDIT_ARCH
355	def_bool y if X86_64
356
357config KASAN_SHADOW_OFFSET
358	hex
359	depends on KASAN
360	default 0xdffffc0000000000
361
362config HAVE_INTEL_TXT
363	def_bool y
364	depends on INTEL_IOMMU && ACPI
365
366config X86_32_SMP
367	def_bool y
368	depends on X86_32 && SMP
369
370config X86_64_SMP
371	def_bool y
372	depends on X86_64 && SMP
373
374config ARCH_SUPPORTS_UPROBES
375	def_bool y
376
377config FIX_EARLYCON_MEM
378	def_bool y
379
380config DYNAMIC_PHYSICAL_MASK
381	bool
382
383config PGTABLE_LEVELS
384	int
385	default 5 if X86_5LEVEL
386	default 4 if X86_64
387	default 3 if X86_PAE
388	default 2
389
390config CC_HAS_SANE_STACKPROTECTOR
391	bool
392	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
393	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
394	help
395	   We have to make sure stack protector is unconditionally disabled if
396	   the compiler produces broken code or if it does not let us control
397	   the segment on 32-bit kernels.
398
399menu "Processor type and features"
400
401config SMP
402	bool "Symmetric multi-processing support"
403	help
404	  This enables support for systems with more than one CPU. If you have
405	  a system with only one CPU, say N. If you have a system with more
406	  than one CPU, say Y.
407
408	  If you say N here, the kernel will run on uni- and multiprocessor
409	  machines, but will use only one CPU of a multiprocessor machine. If
410	  you say Y here, the kernel will run on many, but not all,
411	  uniprocessor machines. On a uniprocessor machine, the kernel
412	  will run faster if you say N here.
413
414	  Note that if you say Y here and choose architecture "586" or
415	  "Pentium" under "Processor family", the kernel will not work on 486
416	  architectures. Similarly, multiprocessor kernels for the "PPro"
417	  architecture may not work on all Pentium based boards.
418
419	  People using multiprocessor machines who say Y here should also say
420	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
421	  Management" code will be disabled if you say Y here.
422
423	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
424	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
425	  <http://www.tldp.org/docs.html#howto>.
426
427	  If you don't know what to do here, say N.
428
429config X86_FEATURE_NAMES
430	bool "Processor feature human-readable names" if EMBEDDED
431	default y
432	help
433	  This option compiles in a table of x86 feature bits and corresponding
434	  names.  This is required to support /proc/cpuinfo and a few kernel
435	  messages.  You can disable this to save space, at the expense of
436	  making those few kernel messages show numeric feature bits instead.
437
438	  If in doubt, say Y.
439
440config X86_X2APIC
441	bool "Support x2apic"
442	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
443	help
444	  This enables x2apic support on CPUs that have this feature.
445
446	  This allows 32-bit apic IDs (so it can support very large systems),
447	  and accesses the local apic via MSRs not via mmio.
448
449	  If you don't know what to do here, say N.
450
451config X86_MPPARSE
452	bool "Enable MPS table" if ACPI
453	default y
454	depends on X86_LOCAL_APIC
455	help
456	  For old smp systems that do not have proper acpi support. Newer systems
457	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
458
459config GOLDFISH
460	def_bool y
461	depends on X86_GOLDFISH
462
463config RETPOLINE
464	bool "Avoid speculative indirect branches in kernel"
465	default y
466	help
467	  Compile kernel with the retpoline compiler options to guard against
468	  kernel-to-user data leaks by avoiding speculative indirect
469	  branches. Requires a compiler with -mindirect-branch=thunk-extern
470	  support for full protection. The kernel may run slower.
471
472config X86_CPU_RESCTRL
473	bool "x86 CPU resource control support"
474	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
475	select KERNFS
476	select PROC_CPU_RESCTRL		if PROC_FS
477	help
478	  Enable x86 CPU resource control support.
479
480	  Provide support for the allocation and monitoring of system resources
481	  usage by the CPU.
482
483	  Intel calls this Intel Resource Director Technology
484	  (Intel(R) RDT). More information about RDT can be found in the
485	  Intel x86 Architecture Software Developer Manual.
486
487	  AMD calls this AMD Platform Quality of Service (AMD QoS).
488	  More information about AMD QoS can be found in the AMD64 Technology
489	  Platform Quality of Service Extensions manual.
490
491	  Say N if unsure.
492
493if X86_32
494config X86_BIGSMP
495	bool "Support for big SMP systems with more than 8 CPUs"
496	depends on SMP
497	help
498	  This option is needed for the systems that have more than 8 CPUs.
499
500config X86_EXTENDED_PLATFORM
501	bool "Support for extended (non-PC) x86 platforms"
502	default y
503	help
504	  If you disable this option then the kernel will only support
505	  standard PC platforms. (which covers the vast majority of
506	  systems out there.)
507
508	  If you enable this option then you'll be able to select support
509	  for the following (non-PC) 32 bit x86 platforms:
510		Goldfish (Android emulator)
511		AMD Elan
512		RDC R-321x SoC
513		SGI 320/540 (Visual Workstation)
514		STA2X11-based (e.g. Northville)
515		Moorestown MID devices
516
517	  If you have one of these systems, or if you want to build a
518	  generic distribution kernel, say Y here - otherwise say N.
519endif
520
521if X86_64
522config X86_EXTENDED_PLATFORM
523	bool "Support for extended (non-PC) x86 platforms"
524	default y
525	help
526	  If you disable this option then the kernel will only support
527	  standard PC platforms. (which covers the vast majority of
528	  systems out there.)
529
530	  If you enable this option then you'll be able to select support
531	  for the following (non-PC) 64 bit x86 platforms:
532		Numascale NumaChip
533		ScaleMP vSMP
534		SGI Ultraviolet
535
536	  If you have one of these systems, or if you want to build a
537	  generic distribution kernel, say Y here - otherwise say N.
538endif
539# This is an alphabetically sorted list of 64 bit extended platforms
540# Please maintain the alphabetic order if and when there are additions
541config X86_NUMACHIP
542	bool "Numascale NumaChip"
543	depends on X86_64
544	depends on X86_EXTENDED_PLATFORM
545	depends on NUMA
546	depends on SMP
547	depends on X86_X2APIC
548	depends on PCI_MMCONFIG
549	help
550	  Adds support for Numascale NumaChip large-SMP systems. Needed to
551	  enable more than ~168 cores.
552	  If you don't have one of these, you should say N here.
553
554config X86_VSMP
555	bool "ScaleMP vSMP"
556	select HYPERVISOR_GUEST
557	select PARAVIRT
558	depends on X86_64 && PCI
559	depends on X86_EXTENDED_PLATFORM
560	depends on SMP
561	help
562	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
563	  supposed to run on these EM64T-based machines.  Only choose this option
564	  if you have one of these machines.
565
566config X86_UV
567	bool "SGI Ultraviolet"
568	depends on X86_64
569	depends on X86_EXTENDED_PLATFORM
570	depends on NUMA
571	depends on EFI
572	depends on KEXEC_CORE
573	depends on X86_X2APIC
574	depends on PCI
575	help
576	  This option is needed in order to support SGI Ultraviolet systems.
577	  If you don't have one of these, you should say N here.
578
579# Following is an alphabetically sorted list of 32 bit extended platforms
580# Please maintain the alphabetic order if and when there are additions
581
582config X86_GOLDFISH
583	bool "Goldfish (Virtual Platform)"
584	depends on X86_EXTENDED_PLATFORM
585	help
586	 Enable support for the Goldfish virtual platform used primarily
587	 for Android development. Unless you are building for the Android
588	 Goldfish emulator say N here.
589
590config X86_INTEL_CE
591	bool "CE4100 TV platform"
592	depends on PCI
593	depends on PCI_GODIRECT
594	depends on X86_IO_APIC
595	depends on X86_32
596	depends on X86_EXTENDED_PLATFORM
597	select X86_REBOOTFIXUPS
598	select OF
599	select OF_EARLY_FLATTREE
600	help
601	  Select for the Intel CE media processor (CE4100) SOC.
602	  This option compiles in support for the CE4100 SOC for settop
603	  boxes and media devices.
604
605config X86_INTEL_MID
606	bool "Intel MID platform support"
607	depends on X86_EXTENDED_PLATFORM
608	depends on X86_PLATFORM_DEVICES
609	depends on PCI
610	depends on X86_64 || (PCI_GOANY && X86_32)
611	depends on X86_IO_APIC
612	select I2C
613	select DW_APB_TIMER
614	select APB_TIMER
615	select INTEL_SCU_PCI
616	select MFD_INTEL_MSIC
617	help
618	  Select to build a kernel capable of supporting Intel MID (Mobile
619	  Internet Device) platform systems which do not have the PCI legacy
620	  interfaces. If you are building for a PC class system say N here.
621
622	  Intel MID platforms are based on an Intel processor and chipset which
623	  consume less power than most of the x86 derivatives.
624
625config X86_INTEL_QUARK
626	bool "Intel Quark platform support"
627	depends on X86_32
628	depends on X86_EXTENDED_PLATFORM
629	depends on X86_PLATFORM_DEVICES
630	depends on X86_TSC
631	depends on PCI
632	depends on PCI_GOANY
633	depends on X86_IO_APIC
634	select IOSF_MBI
635	select INTEL_IMR
636	select COMMON_CLK
637	help
638	  Select to include support for Quark X1000 SoC.
639	  Say Y here if you have a Quark based system such as the Arduino
640	  compatible Intel Galileo.
641
642config X86_INTEL_LPSS
643	bool "Intel Low Power Subsystem Support"
644	depends on X86 && ACPI && PCI
645	select COMMON_CLK
646	select PINCTRL
647	select IOSF_MBI
648	help
649	  Select to build support for Intel Low Power Subsystem such as
650	  found on Intel Lynxpoint PCH. Selecting this option enables
651	  things like clock tree (common clock framework) and pincontrol
652	  which are needed by the LPSS peripheral drivers.
653
654config X86_AMD_PLATFORM_DEVICE
655	bool "AMD ACPI2Platform devices support"
656	depends on ACPI
657	select COMMON_CLK
658	select PINCTRL
659	help
660	  Select to interpret AMD specific ACPI device to platform device
661	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
662	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
663	  implemented under PINCTRL subsystem.
664
665config IOSF_MBI
666	tristate "Intel SoC IOSF Sideband support for SoC platforms"
667	depends on PCI
668	help
669	  This option enables sideband register access support for Intel SoC
670	  platforms. On these platforms the IOSF sideband is used in lieu of
671	  MSR's for some register accesses, mostly but not limited to thermal
672	  and power. Drivers may query the availability of this device to
673	  determine if they need the sideband in order to work on these
674	  platforms. The sideband is available on the following SoC products.
675	  This list is not meant to be exclusive.
676	   - BayTrail
677	   - Braswell
678	   - Quark
679
680	  You should say Y if you are running a kernel on one of these SoC's.
681
682config IOSF_MBI_DEBUG
683	bool "Enable IOSF sideband access through debugfs"
684	depends on IOSF_MBI && DEBUG_FS
685	help
686	  Select this option to expose the IOSF sideband access registers (MCR,
687	  MDR, MCRX) through debugfs to write and read register information from
688	  different units on the SoC. This is most useful for obtaining device
689	  state information for debug and analysis. As this is a general access
690	  mechanism, users of this option would have specific knowledge of the
691	  device they want to access.
692
693	  If you don't require the option or are in doubt, say N.
694
695config X86_RDC321X
696	bool "RDC R-321x SoC"
697	depends on X86_32
698	depends on X86_EXTENDED_PLATFORM
699	select M486
700	select X86_REBOOTFIXUPS
701	help
702	  This option is needed for RDC R-321x system-on-chip, also known
703	  as R-8610-(G).
704	  If you don't have one of these chips, you should say N here.
705
706config X86_32_NON_STANDARD
707	bool "Support non-standard 32-bit SMP architectures"
708	depends on X86_32 && SMP
709	depends on X86_EXTENDED_PLATFORM
710	help
711	  This option compiles in the bigsmp and STA2X11 default
712	  subarchitectures.  It is intended for a generic binary
713	  kernel. If you select them all, kernel will probe it one by
714	  one and will fallback to default.
715
716# Alphabetically sorted list of Non standard 32 bit platforms
717
718config X86_SUPPORTS_MEMORY_FAILURE
719	def_bool y
720	# MCE code calls memory_failure():
721	depends on X86_MCE
722	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
723	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
724	depends on X86_64 || !SPARSEMEM
725	select ARCH_SUPPORTS_MEMORY_FAILURE
726
727config STA2X11
728	bool "STA2X11 Companion Chip Support"
729	depends on X86_32_NON_STANDARD && PCI
730	select SWIOTLB
731	select MFD_STA2X11
732	select GPIOLIB
733	help
734	  This adds support for boards based on the STA2X11 IO-Hub,
735	  a.k.a. "ConneXt". The chip is used in place of the standard
736	  PC chipset, so all "standard" peripherals are missing. If this
737	  option is selected the kernel will still be able to boot on
738	  standard PC machines.
739
740config X86_32_IRIS
741	tristate "Eurobraille/Iris poweroff module"
742	depends on X86_32
743	help
744	  The Iris machines from EuroBraille do not have APM or ACPI support
745	  to shut themselves down properly.  A special I/O sequence is
746	  needed to do so, which is what this module does at
747	  kernel shutdown.
748
749	  This is only for Iris machines from EuroBraille.
750
751	  If unused, say N.
752
753config SCHED_OMIT_FRAME_POINTER
754	def_bool y
755	prompt "Single-depth WCHAN output"
756	depends on X86
757	help
758	  Calculate simpler /proc/<PID>/wchan values. If this option
759	  is disabled then wchan values will recurse back to the
760	  caller function. This provides more accurate wchan values,
761	  at the expense of slightly more scheduling overhead.
762
763	  If in doubt, say "Y".
764
765menuconfig HYPERVISOR_GUEST
766	bool "Linux guest support"
767	help
768	  Say Y here to enable options for running Linux under various hyper-
769	  visors. This option enables basic hypervisor detection and platform
770	  setup.
771
772	  If you say N, all options in this submenu will be skipped and
773	  disabled, and Linux guest support won't be built in.
774
775if HYPERVISOR_GUEST
776
777config PARAVIRT
778	bool "Enable paravirtualization code"
779	depends on HAVE_STATIC_CALL
780	help
781	  This changes the kernel so it can modify itself when it is run
782	  under a hypervisor, potentially improving performance significantly
783	  over full virtualization.  However, when run without a hypervisor
784	  the kernel is theoretically slower and slightly larger.
785
786config PARAVIRT_XXL
787	bool
788
789config PARAVIRT_DEBUG
790	bool "paravirt-ops debugging"
791	depends on PARAVIRT && DEBUG_KERNEL
792	help
793	  Enable to debug paravirt_ops internals.  Specifically, BUG if
794	  a paravirt_op is missing when it is called.
795
796config PARAVIRT_SPINLOCKS
797	bool "Paravirtualization layer for spinlocks"
798	depends on PARAVIRT && SMP
799	help
800	  Paravirtualized spinlocks allow a pvops backend to replace the
801	  spinlock implementation with something virtualization-friendly
802	  (for example, block the virtual CPU rather than spinning).
803
804	  It has a minimal impact on native kernels and gives a nice performance
805	  benefit on paravirtualized KVM / Xen kernels.
806
807	  If you are unsure how to answer this question, answer Y.
808
809config X86_HV_CALLBACK_VECTOR
810	def_bool n
811
812source "arch/x86/xen/Kconfig"
813
814config KVM_GUEST
815	bool "KVM Guest support (including kvmclock)"
816	depends on PARAVIRT
817	select PARAVIRT_CLOCK
818	select ARCH_CPUIDLE_HALTPOLL
819	select X86_HV_CALLBACK_VECTOR
820	default y
821	help
822	  This option enables various optimizations for running under the KVM
823	  hypervisor. It includes a paravirtualized clock, so that instead
824	  of relying on a PIT (or probably other) emulation by the
825	  underlying device model, the host provides the guest with
826	  timing infrastructure such as time of day, and system time
827
828config ARCH_CPUIDLE_HALTPOLL
829	def_bool n
830	prompt "Disable host haltpoll when loading haltpoll driver"
831	help
832	  If virtualized under KVM, disable host haltpoll.
833
834config PVH
835	bool "Support for running PVH guests"
836	help
837	  This option enables the PVH entry point for guest virtual machines
838	  as specified in the x86/HVM direct boot ABI.
839
840config PARAVIRT_TIME_ACCOUNTING
841	bool "Paravirtual steal time accounting"
842	depends on PARAVIRT
843	help
844	  Select this option to enable fine granularity task steal time
845	  accounting. Time spent executing other tasks in parallel with
846	  the current vCPU is discounted from the vCPU power. To account for
847	  that, there can be a small performance impact.
848
849	  If in doubt, say N here.
850
851config PARAVIRT_CLOCK
852	bool
853
854config JAILHOUSE_GUEST
855	bool "Jailhouse non-root cell support"
856	depends on X86_64 && PCI
857	select X86_PM_TIMER
858	help
859	  This option allows to run Linux as guest in a Jailhouse non-root
860	  cell. You can leave this option disabled if you only want to start
861	  Jailhouse and run Linux afterwards in the root cell.
862
863config ACRN_GUEST
864	bool "ACRN Guest support"
865	depends on X86_64
866	select X86_HV_CALLBACK_VECTOR
867	help
868	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
869	  a flexible, lightweight reference open-source hypervisor, built with
870	  real-time and safety-criticality in mind. It is built for embedded
871	  IOT with small footprint and real-time features. More details can be
872	  found in https://projectacrn.org/.
873
874endif #HYPERVISOR_GUEST
875
876source "arch/x86/Kconfig.cpu"
877
878config HPET_TIMER
879	def_bool X86_64
880	prompt "HPET Timer Support" if X86_32
881	help
882	  Use the IA-PC HPET (High Precision Event Timer) to manage
883	  time in preference to the PIT and RTC, if a HPET is
884	  present.
885	  HPET is the next generation timer replacing legacy 8254s.
886	  The HPET provides a stable time base on SMP
887	  systems, unlike the TSC, but it is more expensive to access,
888	  as it is off-chip.  The interface used is documented
889	  in the HPET spec, revision 1.
890
891	  You can safely choose Y here.  However, HPET will only be
892	  activated if the platform and the BIOS support this feature.
893	  Otherwise the 8254 will be used for timing services.
894
895	  Choose N to continue using the legacy 8254 timer.
896
897config HPET_EMULATE_RTC
898	def_bool y
899	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
900
901# Mark as expert because too many people got it wrong.
902# The code disables itself when not needed.
903config DMI
904	default y
905	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
906	bool "Enable DMI scanning" if EXPERT
907	help
908	  Enabled scanning of DMI to identify machine quirks. Say Y
909	  here unless you have verified that your setup is not
910	  affected by entries in the DMI blacklist. Required by PNP
911	  BIOS code.
912
913config GART_IOMMU
914	bool "Old AMD GART IOMMU support"
915	select DMA_OPS
916	select IOMMU_HELPER
917	select SWIOTLB
918	depends on X86_64 && PCI && AMD_NB
919	help
920	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921	  GART based hardware IOMMUs.
922
923	  The GART supports full DMA access for devices with 32-bit access
924	  limitations, on systems with more than 3 GB. This is usually needed
925	  for USB, sound, many IDE/SATA chipsets and some other devices.
926
927	  Newer systems typically have a modern AMD IOMMU, supported via
928	  the CONFIG_AMD_IOMMU=y config option.
929
930	  In normal configurations this driver is only active when needed:
931	  there's more than 3 GB of memory and the system contains a
932	  32-bit limited device.
933
934	  If unsure, say Y.
935
936config MAXSMP
937	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
938	depends on X86_64 && SMP && DEBUG_KERNEL
939	select CPUMASK_OFFSTACK
940	help
941	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
942	  If unsure, say N.
943
944#
945# The maximum number of CPUs supported:
946#
947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948# and which can be configured interactively in the
949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950#
951# The ranges are different on 32-bit and 64-bit kernels, depending on
952# hardware capabilities and scalability features of the kernel.
953#
954# ( If MAXSMP is enabled we just use the highest possible value and disable
955#   interactive configuration. )
956#
957
958config NR_CPUS_RANGE_BEGIN
959	int
960	default NR_CPUS_RANGE_END if MAXSMP
961	default    1 if !SMP
962	default    2
963
964config NR_CPUS_RANGE_END
965	int
966	depends on X86_32
967	default   64 if  SMP &&  X86_BIGSMP
968	default    8 if  SMP && !X86_BIGSMP
969	default    1 if !SMP
970
971config NR_CPUS_RANGE_END
972	int
973	depends on X86_64
974	default 8192 if  SMP && CPUMASK_OFFSTACK
975	default  512 if  SMP && !CPUMASK_OFFSTACK
976	default    1 if !SMP
977
978config NR_CPUS_DEFAULT
979	int
980	depends on X86_32
981	default   32 if  X86_BIGSMP
982	default    8 if  SMP
983	default    1 if !SMP
984
985config NR_CPUS_DEFAULT
986	int
987	depends on X86_64
988	default 8192 if  MAXSMP
989	default   64 if  SMP
990	default    1 if !SMP
991
992config NR_CPUS
993	int "Maximum number of CPUs" if SMP && !MAXSMP
994	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995	default NR_CPUS_DEFAULT
996	help
997	  This allows you to specify the maximum number of CPUs which this
998	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
999	  supported value is 8192, otherwise the maximum value is 512.  The
1000	  minimum value which makes sense is 2.
1001
1002	  This is purely to save memory: each supported CPU adds about 8KB
1003	  to the kernel image.
1004
1005config SCHED_SMT
1006	def_bool y if SMP
1007
1008config SCHED_MC
1009	def_bool y
1010	prompt "Multi-core scheduler support"
1011	depends on SMP
1012	help
1013	  Multi-core scheduler support improves the CPU scheduler's decision
1014	  making when dealing with multi-core CPU chips at a cost of slightly
1015	  increased overhead in some places. If unsure say N here.
1016
1017config SCHED_MC_PRIO
1018	bool "CPU core priorities scheduler support"
1019	depends on SCHED_MC && CPU_SUP_INTEL
1020	select X86_INTEL_PSTATE
1021	select CPU_FREQ
1022	default y
1023	help
1024	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025	  core ordering determined at manufacturing time, which allows
1026	  certain cores to reach higher turbo frequencies (when running
1027	  single threaded workloads) than others.
1028
1029	  Enabling this kernel feature teaches the scheduler about
1030	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031	  scheduler's CPU selection logic accordingly, so that higher
1032	  overall system performance can be achieved.
1033
1034	  This feature will have no effect on CPUs without this feature.
1035
1036	  If unsure say Y here.
1037
1038config UP_LATE_INIT
1039	def_bool y
1040	depends on !SMP && X86_LOCAL_APIC
1041
1042config X86_UP_APIC
1043	bool "Local APIC support on uniprocessors" if !PCI_MSI
1044	default PCI_MSI
1045	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1046	help
1047	  A local APIC (Advanced Programmable Interrupt Controller) is an
1048	  integrated interrupt controller in the CPU. If you have a single-CPU
1049	  system which has a processor with a local APIC, you can say Y here to
1050	  enable and use it. If you say Y here even though your machine doesn't
1051	  have a local APIC, then the kernel will still run with no slowdown at
1052	  all. The local APIC supports CPU-generated self-interrupts (timer,
1053	  performance counters), and the NMI watchdog which detects hard
1054	  lockups.
1055
1056config X86_UP_IOAPIC
1057	bool "IO-APIC support on uniprocessors"
1058	depends on X86_UP_APIC
1059	help
1060	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061	  SMP-capable replacement for PC-style interrupt controllers. Most
1062	  SMP systems and many recent uniprocessor systems have one.
1063
1064	  If you have a single-CPU system with an IO-APIC, you can say Y here
1065	  to use it. If you say Y here even though your machine doesn't have
1066	  an IO-APIC, then the kernel will still run with no slowdown at all.
1067
1068config X86_LOCAL_APIC
1069	def_bool y
1070	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1071	select IRQ_DOMAIN_HIERARCHY
1072	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1073
1074config X86_IO_APIC
1075	def_bool y
1076	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1077
1078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1079	bool "Reroute for broken boot IRQs"
1080	depends on X86_IO_APIC
1081	help
1082	  This option enables a workaround that fixes a source of
1083	  spurious interrupts. This is recommended when threaded
1084	  interrupt handling is used on systems where the generation of
1085	  superfluous "boot interrupts" cannot be disabled.
1086
1087	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1088	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1089	  kernel does during interrupt handling). On chipsets where this
1090	  boot IRQ generation cannot be disabled, this workaround keeps
1091	  the original IRQ line masked so that only the equivalent "boot
1092	  IRQ" is delivered to the CPUs. The workaround also tells the
1093	  kernel to set up the IRQ handler on the boot IRQ line. In this
1094	  way only one interrupt is delivered to the kernel. Otherwise
1095	  the spurious second interrupt may cause the kernel to bring
1096	  down (vital) interrupt lines.
1097
1098	  Only affects "broken" chipsets. Interrupt sharing may be
1099	  increased on these systems.
1100
1101config X86_MCE
1102	bool "Machine Check / overheating reporting"
1103	select GENERIC_ALLOCATOR
1104	default y
1105	help
1106	  Machine Check support allows the processor to notify the
1107	  kernel if it detects a problem (e.g. overheating, data corruption).
1108	  The action the kernel takes depends on the severity of the problem,
1109	  ranging from warning messages to halting the machine.
1110
1111config X86_MCELOG_LEGACY
1112	bool "Support for deprecated /dev/mcelog character device"
1113	depends on X86_MCE
1114	help
1115	  Enable support for /dev/mcelog which is needed by the old mcelog
1116	  userspace logging daemon. Consider switching to the new generation
1117	  rasdaemon solution.
1118
1119config X86_MCE_INTEL
1120	def_bool y
1121	prompt "Intel MCE features"
1122	depends on X86_MCE && X86_LOCAL_APIC
1123	help
1124	   Additional support for intel specific MCE features such as
1125	   the thermal monitor.
1126
1127config X86_MCE_AMD
1128	def_bool y
1129	prompt "AMD MCE features"
1130	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1131	help
1132	   Additional support for AMD specific MCE features such as
1133	   the DRAM Error Threshold.
1134
1135config X86_ANCIENT_MCE
1136	bool "Support for old Pentium 5 / WinChip machine checks"
1137	depends on X86_32 && X86_MCE
1138	help
1139	  Include support for machine check handling on old Pentium 5 or WinChip
1140	  systems. These typically need to be enabled explicitly on the command
1141	  line.
1142
1143config X86_MCE_THRESHOLD
1144	depends on X86_MCE_AMD || X86_MCE_INTEL
1145	def_bool y
1146
1147config X86_MCE_INJECT
1148	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1149	tristate "Machine check injector support"
1150	help
1151	  Provide support for injecting machine checks for testing purposes.
1152	  If you don't know what a machine check is and you don't do kernel
1153	  QA it is safe to say n.
1154
1155source "arch/x86/events/Kconfig"
1156
1157config X86_LEGACY_VM86
1158	bool "Legacy VM86 support"
1159	depends on X86_32
1160	help
1161	  This option allows user programs to put the CPU into V8086
1162	  mode, which is an 80286-era approximation of 16-bit real mode.
1163
1164	  Some very old versions of X and/or vbetool require this option
1165	  for user mode setting.  Similarly, DOSEMU will use it if
1166	  available to accelerate real mode DOS programs.  However, any
1167	  recent version of DOSEMU, X, or vbetool should be fully
1168	  functional even without kernel VM86 support, as they will all
1169	  fall back to software emulation. Nevertheless, if you are using
1170	  a 16-bit DOS program where 16-bit performance matters, vm86
1171	  mode might be faster than emulation and you might want to
1172	  enable this option.
1173
1174	  Note that any app that works on a 64-bit kernel is unlikely to
1175	  need this option, as 64-bit kernels don't, and can't, support
1176	  V8086 mode. This option is also unrelated to 16-bit protected
1177	  mode and is not needed to run most 16-bit programs under Wine.
1178
1179	  Enabling this option increases the complexity of the kernel
1180	  and slows down exception handling a tiny bit.
1181
1182	  If unsure, say N here.
1183
1184config VM86
1185	bool
1186	default X86_LEGACY_VM86
1187
1188config X86_16BIT
1189	bool "Enable support for 16-bit segments" if EXPERT
1190	default y
1191	depends on MODIFY_LDT_SYSCALL
1192	help
1193	  This option is required by programs like Wine to run 16-bit
1194	  protected mode legacy code on x86 processors.  Disabling
1195	  this option saves about 300 bytes on i386, or around 6K text
1196	  plus 16K runtime memory on x86-64,
1197
1198config X86_ESPFIX32
1199	def_bool y
1200	depends on X86_16BIT && X86_32
1201
1202config X86_ESPFIX64
1203	def_bool y
1204	depends on X86_16BIT && X86_64
1205
1206config X86_VSYSCALL_EMULATION
1207	bool "Enable vsyscall emulation" if EXPERT
1208	default y
1209	depends on X86_64
1210	help
1211	 This enables emulation of the legacy vsyscall page.  Disabling
1212	 it is roughly equivalent to booting with vsyscall=none, except
1213	 that it will also disable the helpful warning if a program
1214	 tries to use a vsyscall.  With this option set to N, offending
1215	 programs will just segfault, citing addresses of the form
1216	 0xffffffffff600?00.
1217
1218	 This option is required by many programs built before 2013, and
1219	 care should be used even with newer programs if set to N.
1220
1221	 Disabling this option saves about 7K of kernel size and
1222	 possibly 4K of additional runtime pagetable memory.
1223
1224config X86_IOPL_IOPERM
1225	bool "IOPERM and IOPL Emulation"
1226	default y
1227	help
1228	  This enables the ioperm() and iopl() syscalls which are necessary
1229	  for legacy applications.
1230
1231	  Legacy IOPL support is an overbroad mechanism which allows user
1232	  space aside of accessing all 65536 I/O ports also to disable
1233	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1234	  capabilities and permission from potentially active security
1235	  modules.
1236
1237	  The emulation restricts the functionality of the syscall to
1238	  only allowing the full range I/O port access, but prevents the
1239	  ability to disable interrupts from user space which would be
1240	  granted if the hardware IOPL mechanism would be used.
1241
1242config TOSHIBA
1243	tristate "Toshiba Laptop support"
1244	depends on X86_32
1245	help
1246	  This adds a driver to safely access the System Management Mode of
1247	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248	  not work on models with a Phoenix BIOS. The System Management Mode
1249	  is used to set the BIOS and power saving options on Toshiba portables.
1250
1251	  For information on utilities to make use of this driver see the
1252	  Toshiba Linux utilities web site at:
1253	  <http://www.buzzard.org.uk/toshiba/>.
1254
1255	  Say Y if you intend to run this kernel on a Toshiba portable.
1256	  Say N otherwise.
1257
1258config I8K
1259	tristate "Dell i8k legacy laptop support"
1260	select HWMON
1261	select SENSORS_DELL_SMM
1262	help
1263	  This option enables legacy /proc/i8k userspace interface in hwmon
1264	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265	  temperature and allows controlling fan speeds of Dell laptops via
1266	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267	  it reports also power and hotkey status. For fan speed control is
1268	  needed userspace package i8kutils.
1269
1270	  Say Y if you intend to run this kernel on old Dell laptops or want to
1271	  use userspace package i8kutils.
1272	  Say N otherwise.
1273
1274config X86_REBOOTFIXUPS
1275	bool "Enable X86 board specific fixups for reboot"
1276	depends on X86_32
1277	help
1278	  This enables chipset and/or board specific fixups to be done
1279	  in order to get reboot to work correctly. This is only needed on
1280	  some combinations of hardware and BIOS. The symptom, for which
1281	  this config is intended, is when reboot ends with a stalled/hung
1282	  system.
1283
1284	  Currently, the only fixup is for the Geode machines using
1285	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1286
1287	  Say Y if you want to enable the fixup. Currently, it's safe to
1288	  enable this option even if you don't need it.
1289	  Say N otherwise.
1290
1291config MICROCODE
1292	bool "CPU microcode loading support"
1293	default y
1294	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1295	help
1296	  If you say Y here, you will be able to update the microcode on
1297	  Intel and AMD processors. The Intel support is for the IA32 family,
1298	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1299	  AMD support is for families 0x10 and later. You will obviously need
1300	  the actual microcode binary data itself which is not shipped with
1301	  the Linux kernel.
1302
1303	  The preferred method to load microcode from a detached initrd is described
1304	  in Documentation/x86/microcode.rst. For that you need to enable
1305	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1306	  initrd for microcode blobs.
1307
1308	  In addition, you can build the microcode into the kernel. For that you
1309	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1310	  config option.
1311
1312config MICROCODE_INTEL
1313	bool "Intel microcode loading support"
1314	depends on MICROCODE
1315	default MICROCODE
1316	help
1317	  This options enables microcode patch loading support for Intel
1318	  processors.
1319
1320	  For the current Intel microcode data package go to
1321	  <https://downloadcenter.intel.com> and search for
1322	  'Linux Processor Microcode Data File'.
1323
1324config MICROCODE_AMD
1325	bool "AMD microcode loading support"
1326	depends on MICROCODE
1327	help
1328	  If you select this option, microcode patch loading support for AMD
1329	  processors will be enabled.
1330
1331config MICROCODE_OLD_INTERFACE
1332	bool "Ancient loading interface (DEPRECATED)"
1333	default n
1334	depends on MICROCODE
1335	help
1336	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1337	  which was used by userspace tools like iucode_tool and microcode.ctl.
1338	  It is inadequate because it runs too late to be able to properly
1339	  load microcode on a machine and it needs special tools. Instead, you
1340	  should've switched to the early loading method with the initrd or
1341	  builtin microcode by now: Documentation/x86/microcode.rst
1342
1343config X86_MSR
1344	tristate "/dev/cpu/*/msr - Model-specific register support"
1345	help
1346	  This device gives privileged processes access to the x86
1347	  Model-Specific Registers (MSRs).  It is a character device with
1348	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1349	  MSR accesses are directed to a specific CPU on multi-processor
1350	  systems.
1351
1352config X86_CPUID
1353	tristate "/dev/cpu/*/cpuid - CPU information support"
1354	help
1355	  This device gives processes access to the x86 CPUID instruction to
1356	  be executed on a specific processor.  It is a character device
1357	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1358	  /dev/cpu/31/cpuid.
1359
1360choice
1361	prompt "High Memory Support"
1362	default HIGHMEM4G
1363	depends on X86_32
1364
1365config NOHIGHMEM
1366	bool "off"
1367	help
1368	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1369	  However, the address space of 32-bit x86 processors is only 4
1370	  Gigabytes large. That means that, if you have a large amount of
1371	  physical memory, not all of it can be "permanently mapped" by the
1372	  kernel. The physical memory that's not permanently mapped is called
1373	  "high memory".
1374
1375	  If you are compiling a kernel which will never run on a machine with
1376	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1377	  choice and suitable for most users). This will result in a "3GB/1GB"
1378	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1379	  space and the remaining part of the 4GB virtual memory space is used
1380	  by the kernel to permanently map as much physical memory as
1381	  possible.
1382
1383	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1384	  answer "4GB" here.
1385
1386	  If more than 4 Gigabytes is used then answer "64GB" here. This
1387	  selection turns Intel PAE (Physical Address Extension) mode on.
1388	  PAE implements 3-level paging on IA32 processors. PAE is fully
1389	  supported by Linux, PAE mode is implemented on all recent Intel
1390	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1391	  then the kernel will not boot on CPUs that don't support PAE!
1392
1393	  The actual amount of total physical memory will either be
1394	  auto detected or can be forced by using a kernel command line option
1395	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1396	  your boot loader (lilo or loadlin) about how to pass options to the
1397	  kernel at boot time.)
1398
1399	  If unsure, say "off".
1400
1401config HIGHMEM4G
1402	bool "4GB"
1403	help
1404	  Select this if you have a 32-bit processor and between 1 and 4
1405	  gigabytes of physical RAM.
1406
1407config HIGHMEM64G
1408	bool "64GB"
1409	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1410	select X86_PAE
1411	help
1412	  Select this if you have a 32-bit processor and more than 4
1413	  gigabytes of physical RAM.
1414
1415endchoice
1416
1417choice
1418	prompt "Memory split" if EXPERT
1419	default VMSPLIT_3G
1420	depends on X86_32
1421	help
1422	  Select the desired split between kernel and user memory.
1423
1424	  If the address range available to the kernel is less than the
1425	  physical memory installed, the remaining memory will be available
1426	  as "high memory". Accessing high memory is a little more costly
1427	  than low memory, as it needs to be mapped into the kernel first.
1428	  Note that increasing the kernel address space limits the range
1429	  available to user programs, making the address space there
1430	  tighter.  Selecting anything other than the default 3G/1G split
1431	  will also likely make your kernel incompatible with binary-only
1432	  kernel modules.
1433
1434	  If you are not absolutely sure what you are doing, leave this
1435	  option alone!
1436
1437	config VMSPLIT_3G
1438		bool "3G/1G user/kernel split"
1439	config VMSPLIT_3G_OPT
1440		depends on !X86_PAE
1441		bool "3G/1G user/kernel split (for full 1G low memory)"
1442	config VMSPLIT_2G
1443		bool "2G/2G user/kernel split"
1444	config VMSPLIT_2G_OPT
1445		depends on !X86_PAE
1446		bool "2G/2G user/kernel split (for full 2G low memory)"
1447	config VMSPLIT_1G
1448		bool "1G/3G user/kernel split"
1449endchoice
1450
1451config PAGE_OFFSET
1452	hex
1453	default 0xB0000000 if VMSPLIT_3G_OPT
1454	default 0x80000000 if VMSPLIT_2G
1455	default 0x78000000 if VMSPLIT_2G_OPT
1456	default 0x40000000 if VMSPLIT_1G
1457	default 0xC0000000
1458	depends on X86_32
1459
1460config HIGHMEM
1461	def_bool y
1462	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1463
1464config X86_PAE
1465	bool "PAE (Physical Address Extension) Support"
1466	depends on X86_32 && !HIGHMEM4G
1467	select PHYS_ADDR_T_64BIT
1468	select SWIOTLB
1469	help
1470	  PAE is required for NX support, and furthermore enables
1471	  larger swapspace support for non-overcommit purposes. It
1472	  has the cost of more pagetable lookup overhead, and also
1473	  consumes more pagetable space per process.
1474
1475config X86_5LEVEL
1476	bool "Enable 5-level page tables support"
1477	default y
1478	select DYNAMIC_MEMORY_LAYOUT
1479	select SPARSEMEM_VMEMMAP
1480	depends on X86_64
1481	help
1482	  5-level paging enables access to larger address space:
1483	  upto 128 PiB of virtual address space and 4 PiB of
1484	  physical address space.
1485
1486	  It will be supported by future Intel CPUs.
1487
1488	  A kernel with the option enabled can be booted on machines that
1489	  support 4- or 5-level paging.
1490
1491	  See Documentation/x86/x86_64/5level-paging.rst for more
1492	  information.
1493
1494	  Say N if unsure.
1495
1496config X86_DIRECT_GBPAGES
1497	def_bool y
1498	depends on X86_64
1499	help
1500	  Certain kernel features effectively disable kernel
1501	  linear 1 GB mappings (even if the CPU otherwise
1502	  supports them), so don't confuse the user by printing
1503	  that we have them enabled.
1504
1505config X86_CPA_STATISTICS
1506	bool "Enable statistic for Change Page Attribute"
1507	depends on DEBUG_FS
1508	help
1509	  Expose statistics about the Change Page Attribute mechanism, which
1510	  helps to determine the effectiveness of preserving large and huge
1511	  page mappings when mapping protections are changed.
1512
1513config AMD_MEM_ENCRYPT
1514	bool "AMD Secure Memory Encryption (SME) support"
1515	depends on X86_64 && CPU_SUP_AMD
1516	select DMA_COHERENT_POOL
1517	select DYNAMIC_PHYSICAL_MASK
1518	select ARCH_USE_MEMREMAP_PROT
1519	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1520	select INSTRUCTION_DECODER
1521	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
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 NUMA
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 MATH_EMULATION
1692	bool
1693	depends on MODIFY_LDT_SYSCALL
1694	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1695	help
1696	  Linux can emulate a math coprocessor (used for floating point
1697	  operations) if you don't have one. 486DX and Pentium processors have
1698	  a math coprocessor built in, 486SX and 386 do not, unless you added
1699	  a 487DX or 387, respectively. (The messages during boot time can
1700	  give you some hints here ["man dmesg"].) Everyone needs either a
1701	  coprocessor or this emulation.
1702
1703	  If you don't have a math coprocessor, you need to say Y here; if you
1704	  say Y here even though you have a coprocessor, the coprocessor will
1705	  be used nevertheless. (This behavior can be changed with the kernel
1706	  command line option "no387", which comes handy if your coprocessor
1707	  is broken. Try "man bootparam" or see the documentation of your boot
1708	  loader (lilo or loadlin) about how to pass options to the kernel at
1709	  boot time.) This means that it is a good idea to say Y here if you
1710	  intend to use this kernel on different machines.
1711
1712	  More information about the internals of the Linux math coprocessor
1713	  emulation can be found in <file:arch/x86/math-emu/README>.
1714
1715	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1716	  kernel, it won't hurt.
1717
1718config MTRR
1719	def_bool y
1720	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1721	help
1722	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1723	  the Memory Type Range Registers (MTRRs) may be used to control
1724	  processor access to memory ranges. This is most useful if you have
1725	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1726	  allows bus write transfers to be combined into a larger transfer
1727	  before bursting over the PCI/AGP bus. This can increase performance
1728	  of image write operations 2.5 times or more. Saying Y here creates a
1729	  /proc/mtrr file which may be used to manipulate your processor's
1730	  MTRRs. Typically the X server should use this.
1731
1732	  This code has a reasonably generic interface so that similar
1733	  control registers on other processors can be easily supported
1734	  as well:
1735
1736	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1737	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1738	  these, the ARRs are used to emulate the MTRRs.
1739	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1740	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1741	  write-combining. All of these processors are supported by this code
1742	  and it makes sense to say Y here if you have one of them.
1743
1744	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1745	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1746	  can lead to all sorts of problems, so it's good to say Y here.
1747
1748	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1749	  just add about 9 KB to your kernel.
1750
1751	  See <file:Documentation/x86/mtrr.rst> for more information.
1752
1753config MTRR_SANITIZER
1754	def_bool y
1755	prompt "MTRR cleanup support"
1756	depends on MTRR
1757	help
1758	  Convert MTRR layout from continuous to discrete, so X drivers can
1759	  add writeback entries.
1760
1761	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1762	  The largest mtrr entry size for a continuous block can be set with
1763	  mtrr_chunk_size.
1764
1765	  If unsure, say Y.
1766
1767config MTRR_SANITIZER_ENABLE_DEFAULT
1768	int "MTRR cleanup enable value (0-1)"
1769	range 0 1
1770	default "0"
1771	depends on MTRR_SANITIZER
1772	help
1773	  Enable mtrr cleanup default value
1774
1775config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1776	int "MTRR cleanup spare reg num (0-7)"
1777	range 0 7
1778	default "1"
1779	depends on MTRR_SANITIZER
1780	help
1781	  mtrr cleanup spare entries default, it can be changed via
1782	  mtrr_spare_reg_nr=N on the kernel command line.
1783
1784config X86_PAT
1785	def_bool y
1786	prompt "x86 PAT support" if EXPERT
1787	depends on MTRR
1788	help
1789	  Use PAT attributes to setup page level cache control.
1790
1791	  PATs are the modern equivalents of MTRRs and are much more
1792	  flexible than MTRRs.
1793
1794	  Say N here if you see bootup problems (boot crash, boot hang,
1795	  spontaneous reboots) or a non-working video driver.
1796
1797	  If unsure, say Y.
1798
1799config ARCH_USES_PG_UNCACHED
1800	def_bool y
1801	depends on X86_PAT
1802
1803config ARCH_RANDOM
1804	def_bool y
1805	prompt "x86 architectural random number generator" if EXPERT
1806	help
1807	  Enable the x86 architectural RDRAND instruction
1808	  (Intel Bull Mountain technology) to generate random numbers.
1809	  If supported, this is a high bandwidth, cryptographically
1810	  secure hardware random number generator.
1811
1812config X86_SMAP
1813	def_bool y
1814	prompt "Supervisor Mode Access Prevention" if EXPERT
1815	help
1816	  Supervisor Mode Access Prevention (SMAP) is a security
1817	  feature in newer Intel processors.  There is a small
1818	  performance cost if this enabled and turned on; there is
1819	  also a small increase in the kernel size if this is enabled.
1820
1821	  If unsure, say Y.
1822
1823config X86_UMIP
1824	def_bool y
1825	prompt "User Mode Instruction Prevention" if EXPERT
1826	help
1827	  User Mode Instruction Prevention (UMIP) is a security feature in
1828	  some x86 processors. If enabled, a general protection fault is
1829	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1830	  executed in user mode. These instructions unnecessarily expose
1831	  information about the hardware state.
1832
1833	  The vast majority of applications do not use these instructions.
1834	  For the very few that do, software emulation is provided in
1835	  specific cases in protected and virtual-8086 modes. Emulated
1836	  results are dummy.
1837
1838config X86_INTEL_MEMORY_PROTECTION_KEYS
1839	prompt "Memory Protection Keys"
1840	def_bool y
1841	# Note: only available in 64-bit mode
1842	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1843	select ARCH_USES_HIGH_VMA_FLAGS
1844	select ARCH_HAS_PKEYS
1845	help
1846	  Memory Protection Keys provides a mechanism for enforcing
1847	  page-based protections, but without requiring modification of the
1848	  page tables when an application changes protection domains.
1849
1850	  For details, see Documentation/core-api/protection-keys.rst
1851
1852	  If unsure, say y.
1853
1854choice
1855	prompt "TSX enable mode"
1856	depends on CPU_SUP_INTEL
1857	default X86_INTEL_TSX_MODE_OFF
1858	help
1859	  Intel's TSX (Transactional Synchronization Extensions) feature
1860	  allows to optimize locking protocols through lock elision which
1861	  can lead to a noticeable performance boost.
1862
1863	  On the other hand it has been shown that TSX can be exploited
1864	  to form side channel attacks (e.g. TAA) and chances are there
1865	  will be more of those attacks discovered in the future.
1866
1867	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1868	  might override this decision by tsx=on the command line parameter.
1869	  Even with TSX enabled, the kernel will attempt to enable the best
1870	  possible TAA mitigation setting depending on the microcode available
1871	  for the particular machine.
1872
1873	  This option allows to set the default tsx mode between tsx=on, =off
1874	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1875	  details.
1876
1877	  Say off if not sure, auto if TSX is in use but it should be used on safe
1878	  platforms or on if TSX is in use and the security aspect of tsx is not
1879	  relevant.
1880
1881config X86_INTEL_TSX_MODE_OFF
1882	bool "off"
1883	help
1884	  TSX is disabled if possible - equals to tsx=off command line parameter.
1885
1886config X86_INTEL_TSX_MODE_ON
1887	bool "on"
1888	help
1889	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1890	  line parameter.
1891
1892config X86_INTEL_TSX_MODE_AUTO
1893	bool "auto"
1894	help
1895	  TSX is enabled on TSX capable HW that is believed to be safe against
1896	  side channel attacks- equals the tsx=auto command line parameter.
1897endchoice
1898
1899config X86_SGX
1900	bool "Software Guard eXtensions (SGX)"
1901	depends on X86_64 && CPU_SUP_INTEL
1902	depends on CRYPTO=y
1903	depends on CRYPTO_SHA256=y
1904	select SRCU
1905	select MMU_NOTIFIER
1906	select NUMA_KEEP_MEMINFO if NUMA
1907	help
1908	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1909	  that can be used by applications to set aside private regions of code
1910	  and data, referred to as enclaves. An enclave's private memory can
1911	  only be accessed by code running within the enclave. Accesses from
1912	  outside the enclave, including other enclaves, are disallowed by
1913	  hardware.
1914
1915	  If unsure, say N.
1916
1917config EFI
1918	bool "EFI runtime service support"
1919	depends on ACPI
1920	select UCS2_STRING
1921	select EFI_RUNTIME_WRAPPERS
1922	help
1923	  This enables the kernel to use EFI runtime services that are
1924	  available (such as the EFI variable services).
1925
1926	  This option is only useful on systems that have EFI firmware.
1927	  In addition, you should use the latest ELILO loader available
1928	  at <http://elilo.sourceforge.net> in order to take advantage
1929	  of EFI runtime services. However, even with this option, the
1930	  resultant kernel should continue to boot on existing non-EFI
1931	  platforms.
1932
1933config EFI_STUB
1934	bool "EFI stub support"
1935	depends on EFI && !X86_USE_3DNOW
1936	depends on $(cc-option,-mabi=ms) || X86_32
1937	select RELOCATABLE
1938	help
1939	  This kernel feature allows a bzImage to be loaded directly
1940	  by EFI firmware without the use of a bootloader.
1941
1942	  See Documentation/admin-guide/efi-stub.rst for more information.
1943
1944config EFI_MIXED
1945	bool "EFI mixed-mode support"
1946	depends on EFI_STUB && X86_64
1947	help
1948	   Enabling this feature allows a 64-bit kernel to be booted
1949	   on a 32-bit firmware, provided that your CPU supports 64-bit
1950	   mode.
1951
1952	   Note that it is not possible to boot a mixed-mode enabled
1953	   kernel via the EFI boot stub - a bootloader that supports
1954	   the EFI handover protocol must be used.
1955
1956	   If unsure, say N.
1957
1958source "kernel/Kconfig.hz"
1959
1960config KEXEC
1961	bool "kexec system call"
1962	select KEXEC_CORE
1963	help
1964	  kexec is a system call that implements the ability to shutdown your
1965	  current kernel, and to start another kernel.  It is like a reboot
1966	  but it is independent of the system firmware.   And like a reboot
1967	  you can start any kernel with it, not just Linux.
1968
1969	  The name comes from the similarity to the exec system call.
1970
1971	  It is an ongoing process to be certain the hardware in a machine
1972	  is properly shutdown, so do not be surprised if this code does not
1973	  initially work for you.  As of this writing the exact hardware
1974	  interface is strongly in flux, so no good recommendation can be
1975	  made.
1976
1977config KEXEC_FILE
1978	bool "kexec file based system call"
1979	select KEXEC_CORE
1980	select BUILD_BIN2C
1981	depends on X86_64
1982	depends on CRYPTO=y
1983	depends on CRYPTO_SHA256=y
1984	help
1985	  This is new version of kexec system call. This system call is
1986	  file based and takes file descriptors as system call argument
1987	  for kernel and initramfs as opposed to list of segments as
1988	  accepted by previous system call.
1989
1990config ARCH_HAS_KEXEC_PURGATORY
1991	def_bool KEXEC_FILE
1992
1993config KEXEC_SIG
1994	bool "Verify kernel signature during kexec_file_load() syscall"
1995	depends on KEXEC_FILE
1996	help
1997
1998	  This option makes the kexec_file_load() syscall check for a valid
1999	  signature of the kernel image.  The image can still be loaded without
2000	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2001	  there's a signature that we can check, then it must be valid.
2002
2003	  In addition to this option, you need to enable signature
2004	  verification for the corresponding kernel image type being
2005	  loaded in order for this to work.
2006
2007config KEXEC_SIG_FORCE
2008	bool "Require a valid signature in kexec_file_load() syscall"
2009	depends on KEXEC_SIG
2010	help
2011	  This option makes kernel signature verification mandatory for
2012	  the kexec_file_load() syscall.
2013
2014config KEXEC_BZIMAGE_VERIFY_SIG
2015	bool "Enable bzImage signature verification support"
2016	depends on KEXEC_SIG
2017	depends on SIGNED_PE_FILE_VERIFICATION
2018	select SYSTEM_TRUSTED_KEYRING
2019	help
2020	  Enable bzImage signature verification support.
2021
2022config CRASH_DUMP
2023	bool "kernel crash dumps"
2024	depends on X86_64 || (X86_32 && HIGHMEM)
2025	help
2026	  Generate crash dump after being started by kexec.
2027	  This should be normally only set in special crash dump kernels
2028	  which are loaded in the main kernel with kexec-tools into
2029	  a specially reserved region and then later executed after
2030	  a crash by kdump/kexec. The crash dump kernel must be compiled
2031	  to a memory address not used by the main kernel or BIOS using
2032	  PHYSICAL_START, or it must be built as a relocatable image
2033	  (CONFIG_RELOCATABLE=y).
2034	  For more details see Documentation/admin-guide/kdump/kdump.rst
2035
2036config KEXEC_JUMP
2037	bool "kexec jump"
2038	depends on KEXEC && HIBERNATION
2039	help
2040	  Jump between original kernel and kexeced kernel and invoke
2041	  code in physical address mode via KEXEC
2042
2043config PHYSICAL_START
2044	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2045	default "0x1000000"
2046	help
2047	  This gives the physical address where the kernel is loaded.
2048
2049	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2050	  bzImage will decompress itself to above physical address and
2051	  run from there. Otherwise, bzImage will run from the address where
2052	  it has been loaded by the boot loader and will ignore above physical
2053	  address.
2054
2055	  In normal kdump cases one does not have to set/change this option
2056	  as now bzImage can be compiled as a completely relocatable image
2057	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2058	  address. This option is mainly useful for the folks who don't want
2059	  to use a bzImage for capturing the crash dump and want to use a
2060	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2061	  to be specifically compiled to run from a specific memory area
2062	  (normally a reserved region) and this option comes handy.
2063
2064	  So if you are using bzImage for capturing the crash dump,
2065	  leave the value here unchanged to 0x1000000 and set
2066	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2067	  for capturing the crash dump change this value to start of
2068	  the reserved region.  In other words, it can be set based on
2069	  the "X" value as specified in the "crashkernel=YM@XM"
2070	  command line boot parameter passed to the panic-ed
2071	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2072	  for more details about crash dumps.
2073
2074	  Usage of bzImage for capturing the crash dump is recommended as
2075	  one does not have to build two kernels. Same kernel can be used
2076	  as production kernel and capture kernel. Above option should have
2077	  gone away after relocatable bzImage support is introduced. But it
2078	  is present because there are users out there who continue to use
2079	  vmlinux for dump capture. This option should go away down the
2080	  line.
2081
2082	  Don't change this unless you know what you are doing.
2083
2084config RELOCATABLE
2085	bool "Build a relocatable kernel"
2086	default y
2087	help
2088	  This builds a kernel image that retains relocation information
2089	  so it can be loaded someplace besides the default 1MB.
2090	  The relocations tend to make the kernel binary about 10% larger,
2091	  but are discarded at runtime.
2092
2093	  One use is for the kexec on panic case where the recovery kernel
2094	  must live at a different physical address than the primary
2095	  kernel.
2096
2097	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2098	  it has been loaded at and the compile time physical address
2099	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2100
2101config RANDOMIZE_BASE
2102	bool "Randomize the address of the kernel image (KASLR)"
2103	depends on RELOCATABLE
2104	default y
2105	help
2106	  In support of Kernel Address Space Layout Randomization (KASLR),
2107	  this randomizes the physical address at which the kernel image
2108	  is decompressed and the virtual address where the kernel
2109	  image is mapped, as a security feature that deters exploit
2110	  attempts relying on knowledge of the location of kernel
2111	  code internals.
2112
2113	  On 64-bit, the kernel physical and virtual addresses are
2114	  randomized separately. The physical address will be anywhere
2115	  between 16MB and the top of physical memory (up to 64TB). The
2116	  virtual address will be randomized from 16MB up to 1GB (9 bits
2117	  of entropy). Note that this also reduces the memory space
2118	  available to kernel modules from 1.5GB to 1GB.
2119
2120	  On 32-bit, the kernel physical and virtual addresses are
2121	  randomized together. They will be randomized from 16MB up to
2122	  512MB (8 bits of entropy).
2123
2124	  Entropy is generated using the RDRAND instruction if it is
2125	  supported. If RDTSC is supported, its value is mixed into
2126	  the entropy pool as well. If neither RDRAND nor RDTSC are
2127	  supported, then entropy is read from the i8254 timer. The
2128	  usable entropy is limited by the kernel being built using
2129	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2130	  minimum of 2MB. As a result, only 10 bits of entropy are
2131	  theoretically possible, but the implementations are further
2132	  limited due to memory layouts.
2133
2134	  If unsure, say Y.
2135
2136# Relocation on x86 needs some additional build support
2137config X86_NEED_RELOCS
2138	def_bool y
2139	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2140
2141config PHYSICAL_ALIGN
2142	hex "Alignment value to which kernel should be aligned"
2143	default "0x200000"
2144	range 0x2000 0x1000000 if X86_32
2145	range 0x200000 0x1000000 if X86_64
2146	help
2147	  This value puts the alignment restrictions on physical address
2148	  where kernel is loaded and run from. Kernel is compiled for an
2149	  address which meets above alignment restriction.
2150
2151	  If bootloader loads the kernel at a non-aligned address and
2152	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2153	  address aligned to above value and run from there.
2154
2155	  If bootloader loads the kernel at a non-aligned address and
2156	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2157	  load address and decompress itself to the address it has been
2158	  compiled for and run from there. The address for which kernel is
2159	  compiled already meets above alignment restrictions. Hence the
2160	  end result is that kernel runs from a physical address meeting
2161	  above alignment restrictions.
2162
2163	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2164	  this value must be a multiple of 0x200000.
2165
2166	  Don't change this unless you know what you are doing.
2167
2168config DYNAMIC_MEMORY_LAYOUT
2169	bool
2170	help
2171	  This option makes base addresses of vmalloc and vmemmap as well as
2172	  __PAGE_OFFSET movable during boot.
2173
2174config RANDOMIZE_MEMORY
2175	bool "Randomize the kernel memory sections"
2176	depends on X86_64
2177	depends on RANDOMIZE_BASE
2178	select DYNAMIC_MEMORY_LAYOUT
2179	default RANDOMIZE_BASE
2180	help
2181	   Randomizes the base virtual address of kernel memory sections
2182	   (physical memory mapping, vmalloc & vmemmap). This security feature
2183	   makes exploits relying on predictable memory locations less reliable.
2184
2185	   The order of allocations remains unchanged. Entropy is generated in
2186	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2187	   configuration have in average 30,000 different possible virtual
2188	   addresses for each memory section.
2189
2190	   If unsure, say Y.
2191
2192config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2193	hex "Physical memory mapping padding" if EXPERT
2194	depends on RANDOMIZE_MEMORY
2195	default "0xa" if MEMORY_HOTPLUG
2196	default "0x0"
2197	range 0x1 0x40 if MEMORY_HOTPLUG
2198	range 0x0 0x40
2199	help
2200	   Define the padding in terabytes added to the existing physical
2201	   memory size during kernel memory randomization. It is useful
2202	   for memory hotplug support but reduces the entropy available for
2203	   address randomization.
2204
2205	   If unsure, leave at the default value.
2206
2207config HOTPLUG_CPU
2208	def_bool y
2209	depends on SMP
2210
2211config BOOTPARAM_HOTPLUG_CPU0
2212	bool "Set default setting of cpu0_hotpluggable"
2213	depends on HOTPLUG_CPU
2214	help
2215	  Set whether default state of cpu0_hotpluggable is on or off.
2216
2217	  Say Y here to enable CPU0 hotplug by default. If this switch
2218	  is turned on, there is no need to give cpu0_hotplug kernel
2219	  parameter and the CPU0 hotplug feature is enabled by default.
2220
2221	  Please note: there are two known CPU0 dependencies if you want
2222	  to enable the CPU0 hotplug feature either by this switch or by
2223	  cpu0_hotplug kernel parameter.
2224
2225	  First, resume from hibernate or suspend always starts from CPU0.
2226	  So hibernate and suspend are prevented if CPU0 is offline.
2227
2228	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2229	  offline if any interrupt can not migrate out of CPU0. There may
2230	  be other CPU0 dependencies.
2231
2232	  Please make sure the dependencies are under your control before
2233	  you enable this feature.
2234
2235	  Say N if you don't want to enable CPU0 hotplug feature by default.
2236	  You still can enable the CPU0 hotplug feature at boot by kernel
2237	  parameter cpu0_hotplug.
2238
2239config DEBUG_HOTPLUG_CPU0
2240	def_bool n
2241	prompt "Debug CPU0 hotplug"
2242	depends on HOTPLUG_CPU
2243	help
2244	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2245	  soon as possible and boots up userspace with CPU0 offlined. User
2246	  can online CPU0 back after boot time.
2247
2248	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2249	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2250	  compilation or giving cpu0_hotplug kernel parameter at boot.
2251
2252	  If unsure, say N.
2253
2254config COMPAT_VDSO
2255	def_bool n
2256	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2257	depends on COMPAT_32
2258	help
2259	  Certain buggy versions of glibc will crash if they are
2260	  presented with a 32-bit vDSO that is not mapped at the address
2261	  indicated in its segment table.
2262
2263	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2264	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2265	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2266	  the only released version with the bug, but OpenSUSE 9
2267	  contains a buggy "glibc 2.3.2".
2268
2269	  The symptom of the bug is that everything crashes on startup, saying:
2270	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2271
2272	  Saying Y here changes the default value of the vdso32 boot
2273	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2274	  This works around the glibc bug but hurts performance.
2275
2276	  If unsure, say N: if you are compiling your own kernel, you
2277	  are unlikely to be using a buggy version of glibc.
2278
2279choice
2280	prompt "vsyscall table for legacy applications"
2281	depends on X86_64
2282	default LEGACY_VSYSCALL_XONLY
2283	help
2284	  Legacy user code that does not know how to find the vDSO expects
2285	  to be able to issue three syscalls by calling fixed addresses in
2286	  kernel space. Since this location is not randomized with ASLR,
2287	  it can be used to assist security vulnerability exploitation.
2288
2289	  This setting can be changed at boot time via the kernel command
2290	  line parameter vsyscall=[emulate|xonly|none].
2291
2292	  On a system with recent enough glibc (2.14 or newer) and no
2293	  static binaries, you can say None without a performance penalty
2294	  to improve security.
2295
2296	  If unsure, select "Emulate execution only".
2297
2298	config LEGACY_VSYSCALL_EMULATE
2299		bool "Full emulation"
2300		help
2301		  The kernel traps and emulates calls into the fixed vsyscall
2302		  address mapping. This makes the mapping non-executable, but
2303		  it still contains readable known contents, which could be
2304		  used in certain rare security vulnerability exploits. This
2305		  configuration is recommended when using legacy userspace
2306		  that still uses vsyscalls along with legacy binary
2307		  instrumentation tools that require code to be readable.
2308
2309		  An example of this type of legacy userspace is running
2310		  Pin on an old binary that still uses vsyscalls.
2311
2312	config LEGACY_VSYSCALL_XONLY
2313		bool "Emulate execution only"
2314		help
2315		  The kernel traps and emulates calls into the fixed vsyscall
2316		  address mapping and does not allow reads.  This
2317		  configuration is recommended when userspace might use the
2318		  legacy vsyscall area but support for legacy binary
2319		  instrumentation of legacy code is not needed.  It mitigates
2320		  certain uses of the vsyscall area as an ASLR-bypassing
2321		  buffer.
2322
2323	config LEGACY_VSYSCALL_NONE
2324		bool "None"
2325		help
2326		  There will be no vsyscall mapping at all. This will
2327		  eliminate any risk of ASLR bypass due to the vsyscall
2328		  fixed address mapping. Attempts to use the vsyscalls
2329		  will be reported to dmesg, so that either old or
2330		  malicious userspace programs can be identified.
2331
2332endchoice
2333
2334config CMDLINE_BOOL
2335	bool "Built-in kernel command line"
2336	help
2337	  Allow for specifying boot arguments to the kernel at
2338	  build time.  On some systems (e.g. embedded ones), it is
2339	  necessary or convenient to provide some or all of the
2340	  kernel boot arguments with the kernel itself (that is,
2341	  to not rely on the boot loader to provide them.)
2342
2343	  To compile command line arguments into the kernel,
2344	  set this option to 'Y', then fill in the
2345	  boot arguments in CONFIG_CMDLINE.
2346
2347	  Systems with fully functional boot loaders (i.e. non-embedded)
2348	  should leave this option set to 'N'.
2349
2350config CMDLINE
2351	string "Built-in kernel command string"
2352	depends on CMDLINE_BOOL
2353	default ""
2354	help
2355	  Enter arguments here that should be compiled into the kernel
2356	  image and used at boot time.  If the boot loader provides a
2357	  command line at boot time, it is appended to this string to
2358	  form the full kernel command line, when the system boots.
2359
2360	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2361	  change this behavior.
2362
2363	  In most cases, the command line (whether built-in or provided
2364	  by the boot loader) should specify the device for the root
2365	  file system.
2366
2367config CMDLINE_OVERRIDE
2368	bool "Built-in command line overrides boot loader arguments"
2369	depends on CMDLINE_BOOL && CMDLINE != ""
2370	help
2371	  Set this option to 'Y' to have the kernel ignore the boot loader
2372	  command line, and use ONLY the built-in command line.
2373
2374	  This is used to work around broken boot loaders.  This should
2375	  be set to 'N' under normal conditions.
2376
2377config MODIFY_LDT_SYSCALL
2378	bool "Enable the LDT (local descriptor table)" if EXPERT
2379	default y
2380	help
2381	  Linux can allow user programs to install a per-process x86
2382	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2383	  call.  This is required to run 16-bit or segmented code such as
2384	  DOSEMU or some Wine programs.  It is also used by some very old
2385	  threading libraries.
2386
2387	  Enabling this feature adds a small amount of overhead to
2388	  context switches and increases the low-level kernel attack
2389	  surface.  Disabling it removes the modify_ldt(2) system call.
2390
2391	  Saying 'N' here may make sense for embedded or server kernels.
2392
2393source "kernel/livepatch/Kconfig"
2394
2395endmenu
2396
2397config ARCH_HAS_ADD_PAGES
2398	def_bool y
2399	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2400
2401config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2402	def_bool y
2403
2404config USE_PERCPU_NUMA_NODE_ID
2405	def_bool y
2406	depends on NUMA
2407
2408menu "Power management and ACPI options"
2409
2410config ARCH_HIBERNATION_HEADER
2411	def_bool y
2412	depends on HIBERNATION
2413
2414source "kernel/power/Kconfig"
2415
2416source "drivers/acpi/Kconfig"
2417
2418config X86_APM_BOOT
2419	def_bool y
2420	depends on APM
2421
2422menuconfig APM
2423	tristate "APM (Advanced Power Management) BIOS support"
2424	depends on X86_32 && PM_SLEEP
2425	help
2426	  APM is a BIOS specification for saving power using several different
2427	  techniques. This is mostly useful for battery powered laptops with
2428	  APM compliant BIOSes. If you say Y here, the system time will be
2429	  reset after a RESUME operation, the /proc/apm device will provide
2430	  battery status information, and user-space programs will receive
2431	  notification of APM "events" (e.g. battery status change).
2432
2433	  If you select "Y" here, you can disable actual use of the APM
2434	  BIOS by passing the "apm=off" option to the kernel at boot time.
2435
2436	  Note that the APM support is almost completely disabled for
2437	  machines with more than one CPU.
2438
2439	  In order to use APM, you will need supporting software. For location
2440	  and more information, read <file:Documentation/power/apm-acpi.rst>
2441	  and the Battery Powered Linux mini-HOWTO, available from
2442	  <http://www.tldp.org/docs.html#howto>.
2443
2444	  This driver does not spin down disk drives (see the hdparm(8)
2445	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2446	  VESA-compliant "green" monitors.
2447
2448	  This driver does not support the TI 4000M TravelMate and the ACER
2449	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2450	  desktop machines also don't have compliant BIOSes, and this driver
2451	  may cause those machines to panic during the boot phase.
2452
2453	  Generally, if you don't have a battery in your machine, there isn't
2454	  much point in using this driver and you should say N. If you get
2455	  random kernel OOPSes or reboots that don't seem to be related to
2456	  anything, try disabling/enabling this option (or disabling/enabling
2457	  APM in your BIOS).
2458
2459	  Some other things you should try when experiencing seemingly random,
2460	  "weird" problems:
2461
2462	  1) make sure that you have enough swap space and that it is
2463	  enabled.
2464	  2) pass the "no-hlt" option to the kernel
2465	  3) switch on floating point emulation in the kernel and pass
2466	  the "no387" option to the kernel
2467	  4) pass the "floppy=nodma" option to the kernel
2468	  5) pass the "mem=4M" option to the kernel (thereby disabling
2469	  all but the first 4 MB of RAM)
2470	  6) make sure that the CPU is not over clocked.
2471	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2472	  8) disable the cache from your BIOS settings
2473	  9) install a fan for the video card or exchange video RAM
2474	  10) install a better fan for the CPU
2475	  11) exchange RAM chips
2476	  12) exchange the motherboard.
2477
2478	  To compile this driver as a module, choose M here: the
2479	  module will be called apm.
2480
2481if APM
2482
2483config APM_IGNORE_USER_SUSPEND
2484	bool "Ignore USER SUSPEND"
2485	help
2486	  This option will ignore USER SUSPEND requests. On machines with a
2487	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2488	  series notebooks, it is necessary to say Y because of a BIOS bug.
2489
2490config APM_DO_ENABLE
2491	bool "Enable PM at boot time"
2492	help
2493	  Enable APM features at boot time. From page 36 of the APM BIOS
2494	  specification: "When disabled, the APM BIOS does not automatically
2495	  power manage devices, enter the Standby State, enter the Suspend
2496	  State, or take power saving steps in response to CPU Idle calls."
2497	  This driver will make CPU Idle calls when Linux is idle (unless this
2498	  feature is turned off -- see "Do CPU IDLE calls", below). This
2499	  should always save battery power, but more complicated APM features
2500	  will be dependent on your BIOS implementation. You may need to turn
2501	  this option off if your computer hangs at boot time when using APM
2502	  support, or if it beeps continuously instead of suspending. Turn
2503	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2504	  T400CDT. This is off by default since most machines do fine without
2505	  this feature.
2506
2507config APM_CPU_IDLE
2508	depends on CPU_IDLE
2509	bool "Make CPU Idle calls when idle"
2510	help
2511	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2512	  On some machines, this can activate improved power savings, such as
2513	  a slowed CPU clock rate, when the machine is idle. These idle calls
2514	  are made after the idle loop has run for some length of time (e.g.,
2515	  333 mS). On some machines, this will cause a hang at boot time or
2516	  whenever the CPU becomes idle. (On machines with more than one CPU,
2517	  this option does nothing.)
2518
2519config APM_DISPLAY_BLANK
2520	bool "Enable console blanking using APM"
2521	help
2522	  Enable console blanking using the APM. Some laptops can use this to
2523	  turn off the LCD backlight when the screen blanker of the Linux
2524	  virtual console blanks the screen. Note that this is only used by
2525	  the virtual console screen blanker, and won't turn off the backlight
2526	  when using the X Window system. This also doesn't have anything to
2527	  do with your VESA-compliant power-saving monitor. Further, this
2528	  option doesn't work for all laptops -- it might not turn off your
2529	  backlight at all, or it might print a lot of errors to the console,
2530	  especially if you are using gpm.
2531
2532config APM_ALLOW_INTS
2533	bool "Allow interrupts during APM BIOS calls"
2534	help
2535	  Normally we disable external interrupts while we are making calls to
2536	  the APM BIOS as a measure to lessen the effects of a badly behaving
2537	  BIOS implementation.  The BIOS should reenable interrupts if it
2538	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2539	  many of the newer IBM Thinkpads.  If you experience hangs when you
2540	  suspend, try setting this to Y.  Otherwise, say N.
2541
2542endif # APM
2543
2544source "drivers/cpufreq/Kconfig"
2545
2546source "drivers/cpuidle/Kconfig"
2547
2548source "drivers/idle/Kconfig"
2549
2550endmenu
2551
2552
2553menu "Bus options (PCI etc.)"
2554
2555choice
2556	prompt "PCI access mode"
2557	depends on X86_32 && PCI
2558	default PCI_GOANY
2559	help
2560	  On PCI systems, the BIOS can be used to detect the PCI devices and
2561	  determine their configuration. However, some old PCI motherboards
2562	  have BIOS bugs and may crash if this is done. Also, some embedded
2563	  PCI-based systems don't have any BIOS at all. Linux can also try to
2564	  detect the PCI hardware directly without using the BIOS.
2565
2566	  With this option, you can specify how Linux should detect the
2567	  PCI devices. If you choose "BIOS", the BIOS will be used,
2568	  if you choose "Direct", the BIOS won't be used, and if you
2569	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2570	  If you choose "Any", the kernel will try MMCONFIG, then the
2571	  direct access method and falls back to the BIOS if that doesn't
2572	  work. If unsure, go with the default, which is "Any".
2573
2574config PCI_GOBIOS
2575	bool "BIOS"
2576
2577config PCI_GOMMCONFIG
2578	bool "MMConfig"
2579
2580config PCI_GODIRECT
2581	bool "Direct"
2582
2583config PCI_GOOLPC
2584	bool "OLPC XO-1"
2585	depends on OLPC
2586
2587config PCI_GOANY
2588	bool "Any"
2589
2590endchoice
2591
2592config PCI_BIOS
2593	def_bool y
2594	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2595
2596# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2597config PCI_DIRECT
2598	def_bool y
2599	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2600
2601config PCI_MMCONFIG
2602	bool "Support mmconfig PCI config space access" if X86_64
2603	default y
2604	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2605	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2606
2607config PCI_OLPC
2608	def_bool y
2609	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2610
2611config PCI_XEN
2612	def_bool y
2613	depends on PCI && XEN
2614
2615config MMCONF_FAM10H
2616	def_bool y
2617	depends on X86_64 && PCI_MMCONFIG && ACPI
2618
2619config PCI_CNB20LE_QUIRK
2620	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2621	depends on PCI
2622	help
2623	  Read the PCI windows out of the CNB20LE host bridge. This allows
2624	  PCI hotplug to work on systems with the CNB20LE chipset which do
2625	  not have ACPI.
2626
2627	  There's no public spec for this chipset, and this functionality
2628	  is known to be incomplete.
2629
2630	  You should say N unless you know you need this.
2631
2632config ISA_BUS
2633	bool "ISA bus support on modern systems" if EXPERT
2634	help
2635	  Expose ISA bus device drivers and options available for selection and
2636	  configuration. Enable this option if your target machine has an ISA
2637	  bus. ISA is an older system, displaced by PCI and newer bus
2638	  architectures -- if your target machine is modern, it probably does
2639	  not have an ISA bus.
2640
2641	  If unsure, say N.
2642
2643# x86_64 have no ISA slots, but can have ISA-style DMA.
2644config ISA_DMA_API
2645	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2646	default y
2647	help
2648	  Enables ISA-style DMA support for devices requiring such controllers.
2649	  If unsure, say Y.
2650
2651if X86_32
2652
2653config ISA
2654	bool "ISA support"
2655	help
2656	  Find out whether you have ISA slots on your motherboard.  ISA is the
2657	  name of a bus system, i.e. the way the CPU talks to the other stuff
2658	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2659	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2660	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2661
2662config SCx200
2663	tristate "NatSemi SCx200 support"
2664	help
2665	  This provides basic support for National Semiconductor's
2666	  (now AMD's) Geode processors.  The driver probes for the
2667	  PCI-IDs of several on-chip devices, so its a good dependency
2668	  for other scx200_* drivers.
2669
2670	  If compiled as a module, the driver is named scx200.
2671
2672config SCx200HR_TIMER
2673	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2674	depends on SCx200
2675	default y
2676	help
2677	  This driver provides a clocksource built upon the on-chip
2678	  27MHz high-resolution timer.  Its also a workaround for
2679	  NSC Geode SC-1100's buggy TSC, which loses time when the
2680	  processor goes idle (as is done by the scheduler).  The
2681	  other workaround is idle=poll boot option.
2682
2683config OLPC
2684	bool "One Laptop Per Child support"
2685	depends on !X86_PAE
2686	select GPIOLIB
2687	select OF
2688	select OF_PROMTREE
2689	select IRQ_DOMAIN
2690	select OLPC_EC
2691	help
2692	  Add support for detecting the unique features of the OLPC
2693	  XO hardware.
2694
2695config OLPC_XO1_PM
2696	bool "OLPC XO-1 Power Management"
2697	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2698	help
2699	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2700
2701config OLPC_XO1_RTC
2702	bool "OLPC XO-1 Real Time Clock"
2703	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2704	help
2705	  Add support for the XO-1 real time clock, which can be used as a
2706	  programmable wakeup source.
2707
2708config OLPC_XO1_SCI
2709	bool "OLPC XO-1 SCI extras"
2710	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2711	depends on INPUT=y
2712	select POWER_SUPPLY
2713	help
2714	  Add support for SCI-based features of the OLPC XO-1 laptop:
2715	   - EC-driven system wakeups
2716	   - Power button
2717	   - Ebook switch
2718	   - Lid switch
2719	   - AC adapter status updates
2720	   - Battery status updates
2721
2722config OLPC_XO15_SCI
2723	bool "OLPC XO-1.5 SCI extras"
2724	depends on OLPC && ACPI
2725	select POWER_SUPPLY
2726	help
2727	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2728	   - EC-driven system wakeups
2729	   - AC adapter status updates
2730	   - Battery status updates
2731
2732config ALIX
2733	bool "PCEngines ALIX System Support (LED setup)"
2734	select GPIOLIB
2735	help
2736	  This option enables system support for the PCEngines ALIX.
2737	  At present this just sets up LEDs for GPIO control on
2738	  ALIX2/3/6 boards.  However, other system specific setup should
2739	  get added here.
2740
2741	  Note: You must still enable the drivers for GPIO and LED support
2742	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2743
2744	  Note: You have to set alix.force=1 for boards with Award BIOS.
2745
2746config NET5501
2747	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2748	select GPIOLIB
2749	help
2750	  This option enables system support for the Soekris Engineering net5501.
2751
2752config GEOS
2753	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2754	select GPIOLIB
2755	depends on DMI
2756	help
2757	  This option enables system support for the Traverse Technologies GEOS.
2758
2759config TS5500
2760	bool "Technologic Systems TS-5500 platform support"
2761	depends on MELAN
2762	select CHECK_SIGNATURE
2763	select NEW_LEDS
2764	select LEDS_CLASS
2765	help
2766	  This option enables system support for the Technologic Systems TS-5500.
2767
2768endif # X86_32
2769
2770config AMD_NB
2771	def_bool y
2772	depends on CPU_SUP_AMD && PCI
2773
2774endmenu
2775
2776
2777menu "Binary Emulations"
2778
2779config IA32_EMULATION
2780	bool "IA32 Emulation"
2781	depends on X86_64
2782	select ARCH_WANT_OLD_COMPAT_IPC
2783	select BINFMT_ELF
2784	select COMPAT_OLD_SIGACTION
2785	help
2786	  Include code to run legacy 32-bit programs under a
2787	  64-bit kernel. You should likely turn this on, unless you're
2788	  100% sure that you don't have any 32-bit programs left.
2789
2790config IA32_AOUT
2791	tristate "IA32 a.out support"
2792	depends on IA32_EMULATION
2793	depends on BROKEN
2794	help
2795	  Support old a.out binaries in the 32bit emulation.
2796
2797config X86_X32
2798	bool "x32 ABI for 64-bit mode"
2799	depends on X86_64
2800	help
2801	  Include code to run binaries for the x32 native 32-bit ABI
2802	  for 64-bit processors.  An x32 process gets access to the
2803	  full 64-bit register file and wide data path while leaving
2804	  pointers at 32 bits for smaller memory footprint.
2805
2806	  You will need a recent binutils (2.22 or later) with
2807	  elf32_x86_64 support enabled to compile a kernel with this
2808	  option set.
2809
2810config COMPAT_32
2811	def_bool y
2812	depends on IA32_EMULATION || X86_32
2813	select HAVE_UID16
2814	select OLD_SIGSUSPEND3
2815
2816config COMPAT
2817	def_bool y
2818	depends on IA32_EMULATION || X86_X32
2819
2820if COMPAT
2821config COMPAT_FOR_U64_ALIGNMENT
2822	def_bool y
2823
2824config SYSVIPC_COMPAT
2825	def_bool y
2826	depends on SYSVIPC
2827endif
2828
2829endmenu
2830
2831
2832config HAVE_ATOMIC_IOMAP
2833	def_bool y
2834	depends on X86_32
2835
2836source "drivers/firmware/Kconfig"
2837
2838source "arch/x86/kvm/Kconfig"
2839
2840source "arch/x86/Kconfig.assembler"
2841