xref: /openbmc/linux/arch/x86/Kconfig (revision d35ac6ac)
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_SUPPORTS_PER_VMA_LOCK
31	select ARCH_USE_CMPXCHG_LOCKREF
32	select HAVE_ARCH_SOFT_DIRTY
33	select MODULES_USE_ELF_RELA
34	select NEED_DMA_MAP_STATE
35	select SWIOTLB
36	select ARCH_HAS_ELFCORE_COMPAT
37	select ZONE_DMA32
38
39config FORCE_DYNAMIC_FTRACE
40	def_bool y
41	depends on X86_32
42	depends on FUNCTION_TRACER
43	select DYNAMIC_FTRACE
44	help
45	  We keep the static function tracing (!DYNAMIC_FTRACE) around
46	  in order to test the non static function tracing in the
47	  generic code, as other architectures still use it. But we
48	  only need to keep it around for x86_64. No need to keep it
49	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
50#
51# Arch settings
52#
53# ( Note that options that are marked 'if X86_64' could in principle be
54#   ported to 32-bit as well. )
55#
56config X86
57	def_bool y
58	#
59	# Note: keep this list sorted alphabetically
60	#
61	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
62	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
63	select ARCH_32BIT_OFF_T			if X86_32
64	select ARCH_CLOCKSOURCE_INIT
65	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
67	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
68	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
69	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
70	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
71	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
72	select ARCH_HAS_CACHE_LINE_SIZE
73	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
74	select ARCH_HAS_CPU_FINALIZE_INIT
75	select ARCH_HAS_CURRENT_STACK_POINTER
76	select ARCH_HAS_DEBUG_VIRTUAL
77	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
78	select ARCH_HAS_DEVMEM_IS_ALLOWED
79	select ARCH_HAS_EARLY_DEBUG		if KGDB
80	select ARCH_HAS_ELF_RANDOMIZE
81	select ARCH_HAS_FAST_MULTIPLIER
82	select ARCH_HAS_FORTIFY_SOURCE
83	select ARCH_HAS_GCOV_PROFILE_ALL
84	select ARCH_HAS_KCOV			if X86_64
85	select ARCH_HAS_MEM_ENCRYPT
86	select ARCH_HAS_MEMBARRIER_SYNC_CORE
87	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
88	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
89	select ARCH_HAS_PMEM_API		if X86_64
90	select ARCH_HAS_PTE_DEVMAP		if X86_64
91	select ARCH_HAS_PTE_SPECIAL
92	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
93	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
94	select ARCH_HAS_COPY_MC			if X86_64
95	select ARCH_HAS_SET_MEMORY
96	select ARCH_HAS_SET_DIRECT_MAP
97	select ARCH_HAS_STRICT_KERNEL_RWX
98	select ARCH_HAS_STRICT_MODULE_RWX
99	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
100	select ARCH_HAS_SYSCALL_WRAPPER
101	select ARCH_HAS_UBSAN_SANITIZE_ALL
102	select ARCH_HAS_DEBUG_WX
103	select ARCH_HAS_ZONE_DMA_SET if EXPERT
104	select ARCH_HAVE_NMI_SAFE_CMPXCHG
105	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
106	select ARCH_MIGHT_HAVE_PC_PARPORT
107	select ARCH_MIGHT_HAVE_PC_SERIO
108	select ARCH_STACKWALK
109	select ARCH_SUPPORTS_ACPI
110	select ARCH_SUPPORTS_ATOMIC_RMW
111	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
112	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
113	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
114	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
115	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
116	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
117	select ARCH_SUPPORTS_LTO_CLANG
118	select ARCH_SUPPORTS_LTO_CLANG_THIN
119	select ARCH_USE_BUILTIN_BSWAP
120	select ARCH_USE_MEMTEST
121	select ARCH_USE_QUEUED_RWLOCKS
122	select ARCH_USE_QUEUED_SPINLOCKS
123	select ARCH_USE_SYM_ANNOTATIONS
124	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
125	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
126	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
127	select ARCH_WANTS_NO_INSTR
128	select ARCH_WANT_GENERAL_HUGETLB
129	select ARCH_WANT_HUGE_PMD_SHARE
130	select ARCH_WANT_LD_ORPHAN_WARN
131	select ARCH_WANT_OPTIMIZE_VMEMMAP	if X86_64
132	select ARCH_WANTS_THP_SWAP		if X86_64
133	select ARCH_HAS_PARANOID_L1D_FLUSH
134	select BUILDTIME_TABLE_SORT
135	select CLKEVT_I8253
136	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
137	select CLOCKSOURCE_WATCHDOG
138	# Word-size accesses may read uninitialized data past the trailing \0
139	# in strings and cause false KMSAN reports.
140	select DCACHE_WORD_ACCESS		if !KMSAN
141	select DYNAMIC_SIGFRAME
142	select EDAC_ATOMIC_SCRUB
143	select EDAC_SUPPORT
144	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
145	select GENERIC_CLOCKEVENTS_MIN_ADJUST
146	select GENERIC_CMOS_UPDATE
147	select GENERIC_CPU_AUTOPROBE
148	select GENERIC_CPU_VULNERABILITIES
149	select GENERIC_EARLY_IOREMAP
150	select GENERIC_ENTRY
151	select GENERIC_IOMAP
152	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
153	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
154	select GENERIC_IRQ_MIGRATION		if SMP
155	select GENERIC_IRQ_PROBE
156	select GENERIC_IRQ_RESERVATION_MODE
157	select GENERIC_IRQ_SHOW
158	select GENERIC_PENDING_IRQ		if SMP
159	select GENERIC_PTDUMP
160	select GENERIC_SMP_IDLE_THREAD
161	select GENERIC_TIME_VSYSCALL
162	select GENERIC_GETTIMEOFDAY
163	select GENERIC_VDSO_TIME_NS
164	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
165	select HARDIRQS_SW_RESEND
166	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
167	select HAS_IOPORT
168	select HAVE_ACPI_APEI			if ACPI
169	select HAVE_ACPI_APEI_NMI		if ACPI
170	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
171	select HAVE_ARCH_AUDITSYSCALL
172	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
173	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
174	select HAVE_ARCH_JUMP_LABEL
175	select HAVE_ARCH_JUMP_LABEL_RELATIVE
176	select HAVE_ARCH_KASAN			if X86_64
177	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
178	select HAVE_ARCH_KFENCE
179	select HAVE_ARCH_KMSAN			if X86_64
180	select HAVE_ARCH_KGDB
181	select HAVE_ARCH_MMAP_RND_BITS		if MMU
182	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
183	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
184	select HAVE_ARCH_PREL32_RELOCATIONS
185	select HAVE_ARCH_SECCOMP_FILTER
186	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
187	select HAVE_ARCH_STACKLEAK
188	select HAVE_ARCH_TRACEHOOK
189	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
190	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
191	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
192	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
193	select HAVE_ARCH_VMAP_STACK		if X86_64
194	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
195	select HAVE_ARCH_WITHIN_STACK_FRAMES
196	select HAVE_ASM_MODVERSIONS
197	select HAVE_CMPXCHG_DOUBLE
198	select HAVE_CMPXCHG_LOCAL
199	select HAVE_CONTEXT_TRACKING_USER		if X86_64
200	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
201	select HAVE_C_RECORDMCOUNT
202	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
203	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
204	select HAVE_BUILDTIME_MCOUNT_SORT
205	select HAVE_DEBUG_KMEMLEAK
206	select HAVE_DMA_CONTIGUOUS
207	select HAVE_DYNAMIC_FTRACE
208	select HAVE_DYNAMIC_FTRACE_WITH_REGS
209	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
210	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
211	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
212	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
213	select HAVE_EBPF_JIT
214	select HAVE_EFFICIENT_UNALIGNED_ACCESS
215	select HAVE_EISA
216	select HAVE_EXIT_THREAD
217	select HAVE_FAST_GUP
218	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
219	select HAVE_FTRACE_MCOUNT_RECORD
220	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
221	select HAVE_FUNCTION_TRACER
222	select HAVE_GCC_PLUGINS
223	select HAVE_HW_BREAKPOINT
224	select HAVE_IOREMAP_PROT
225	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
226	select HAVE_IRQ_TIME_ACCOUNTING
227	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
228	select HAVE_KERNEL_BZIP2
229	select HAVE_KERNEL_GZIP
230	select HAVE_KERNEL_LZ4
231	select HAVE_KERNEL_LZMA
232	select HAVE_KERNEL_LZO
233	select HAVE_KERNEL_XZ
234	select HAVE_KERNEL_ZSTD
235	select HAVE_KPROBES
236	select HAVE_KPROBES_ON_FTRACE
237	select HAVE_FUNCTION_ERROR_INJECTION
238	select HAVE_KRETPROBES
239	select HAVE_RETHOOK
240	select HAVE_KVM
241	select HAVE_LIVEPATCH			if X86_64
242	select HAVE_MIXED_BREAKPOINTS_REGS
243	select HAVE_MOD_ARCH_SPECIFIC
244	select HAVE_MOVE_PMD
245	select HAVE_MOVE_PUD
246	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
247	select HAVE_NMI
248	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
249	select HAVE_OBJTOOL			if X86_64
250	select HAVE_OPTPROBES
251	select HAVE_PCSPKR_PLATFORM
252	select HAVE_PERF_EVENTS
253	select HAVE_PERF_EVENTS_NMI
254	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
255	select HAVE_PCI
256	select HAVE_PERF_REGS
257	select HAVE_PERF_USER_STACK_DUMP
258	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
259	select MMU_GATHER_MERGE_VMAS
260	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
261	select HAVE_REGS_AND_STACK_ACCESS_API
262	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
263	select HAVE_FUNCTION_ARG_ACCESS_API
264	select HAVE_SETUP_PER_CPU_AREA
265	select HAVE_SOFTIRQ_ON_OWN_STACK
266	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
267	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
268	select HAVE_STATIC_CALL
269	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
270	select HAVE_PREEMPT_DYNAMIC_CALL
271	select HAVE_RSEQ
272	select HAVE_RUST			if X86_64
273	select HAVE_SYSCALL_TRACEPOINTS
274	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
275	select HAVE_UNSTABLE_SCHED_CLOCK
276	select HAVE_USER_RETURN_NOTIFIER
277	select HAVE_GENERIC_VDSO
278	select HOTPLUG_PARALLEL			if SMP && X86_64
279	select HOTPLUG_SMT			if SMP
280	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
281	select IRQ_FORCED_THREADING
282	select LOCK_MM_AND_FIND_VMA
283	select NEED_PER_CPU_EMBED_FIRST_CHUNK
284	select NEED_PER_CPU_PAGE_FIRST_CHUNK
285	select NEED_SG_DMA_LENGTH
286	select PCI_DOMAINS			if PCI
287	select PCI_LOCKLESS_CONFIG		if PCI
288	select PERF_EVENTS
289	select RTC_LIB
290	select RTC_MC146818_LIB
291	select SPARSE_IRQ
292	select SYSCTL_EXCEPTION_TRACE
293	select THREAD_INFO_IN_TASK
294	select TRACE_IRQFLAGS_SUPPORT
295	select TRACE_IRQFLAGS_NMI_SUPPORT
296	select USER_STACKTRACE_SUPPORT
297	select HAVE_ARCH_KCSAN			if X86_64
298	select PROC_PID_ARCH_STATUS		if PROC_FS
299	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
300	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
301	select FUNCTION_ALIGNMENT_4B
302	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
303	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
304
305config INSTRUCTION_DECODER
306	def_bool y
307	depends on KPROBES || PERF_EVENTS || UPROBES
308
309config OUTPUT_FORMAT
310	string
311	default "elf32-i386" if X86_32
312	default "elf64-x86-64" if X86_64
313
314config LOCKDEP_SUPPORT
315	def_bool y
316
317config STACKTRACE_SUPPORT
318	def_bool y
319
320config MMU
321	def_bool y
322
323config ARCH_MMAP_RND_BITS_MIN
324	default 28 if 64BIT
325	default 8
326
327config ARCH_MMAP_RND_BITS_MAX
328	default 32 if 64BIT
329	default 16
330
331config ARCH_MMAP_RND_COMPAT_BITS_MIN
332	default 8
333
334config ARCH_MMAP_RND_COMPAT_BITS_MAX
335	default 16
336
337config SBUS
338	bool
339
340config GENERIC_ISA_DMA
341	def_bool y
342	depends on ISA_DMA_API
343
344config GENERIC_CSUM
345	bool
346	default y if KMSAN || KASAN
347
348config GENERIC_BUG
349	def_bool y
350	depends on BUG
351	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
352
353config GENERIC_BUG_RELATIVE_POINTERS
354	bool
355
356config ARCH_MAY_HAVE_PC_FDC
357	def_bool y
358	depends on ISA_DMA_API
359
360config GENERIC_CALIBRATE_DELAY
361	def_bool y
362
363config ARCH_HAS_CPU_RELAX
364	def_bool y
365
366config ARCH_HIBERNATION_POSSIBLE
367	def_bool y
368
369config ARCH_SUSPEND_POSSIBLE
370	def_bool y
371
372config AUDIT_ARCH
373	def_bool y if X86_64
374
375config KASAN_SHADOW_OFFSET
376	hex
377	depends on KASAN
378	default 0xdffffc0000000000
379
380config HAVE_INTEL_TXT
381	def_bool y
382	depends on INTEL_IOMMU && ACPI
383
384config X86_32_SMP
385	def_bool y
386	depends on X86_32 && SMP
387
388config X86_64_SMP
389	def_bool y
390	depends on X86_64 && SMP
391
392config ARCH_SUPPORTS_UPROBES
393	def_bool y
394
395config FIX_EARLYCON_MEM
396	def_bool y
397
398config DYNAMIC_PHYSICAL_MASK
399	bool
400
401config PGTABLE_LEVELS
402	int
403	default 5 if X86_5LEVEL
404	default 4 if X86_64
405	default 3 if X86_PAE
406	default 2
407
408config CC_HAS_SANE_STACKPROTECTOR
409	bool
410	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
411	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
412	help
413	  We have to make sure stack protector is unconditionally disabled if
414	  the compiler produces broken code or if it does not let us control
415	  the segment on 32-bit kernels.
416
417menu "Processor type and features"
418
419config SMP
420	bool "Symmetric multi-processing support"
421	help
422	  This enables support for systems with more than one CPU. If you have
423	  a system with only one CPU, say N. If you have a system with more
424	  than one CPU, say Y.
425
426	  If you say N here, the kernel will run on uni- and multiprocessor
427	  machines, but will use only one CPU of a multiprocessor machine. If
428	  you say Y here, the kernel will run on many, but not all,
429	  uniprocessor machines. On a uniprocessor machine, the kernel
430	  will run faster if you say N here.
431
432	  Note that if you say Y here and choose architecture "586" or
433	  "Pentium" under "Processor family", the kernel will not work on 486
434	  architectures. Similarly, multiprocessor kernels for the "PPro"
435	  architecture may not work on all Pentium based boards.
436
437	  People using multiprocessor machines who say Y here should also say
438	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
439	  Management" code will be disabled if you say Y here.
440
441	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
442	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
443	  <http://www.tldp.org/docs.html#howto>.
444
445	  If you don't know what to do here, say N.
446
447config X86_X2APIC
448	bool "Support x2apic"
449	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
450	help
451	  This enables x2apic support on CPUs that have this feature.
452
453	  This allows 32-bit apic IDs (so it can support very large systems),
454	  and accesses the local apic via MSRs not via mmio.
455
456	  Some Intel systems circa 2022 and later are locked into x2APIC mode
457	  and can not fall back to the legacy APIC modes if SGX or TDX are
458	  enabled in the BIOS. They will boot with very reduced functionality
459	  without enabling this option.
460
461	  If you don't know what to do here, say N.
462
463config X86_MPPARSE
464	bool "Enable MPS table" if ACPI
465	default y
466	depends on X86_LOCAL_APIC
467	help
468	  For old smp systems that do not have proper acpi support. Newer systems
469	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
470
471config GOLDFISH
472	def_bool y
473	depends on X86_GOLDFISH
474
475config X86_CPU_RESCTRL
476	bool "x86 CPU resource control support"
477	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
478	select KERNFS
479	select PROC_CPU_RESCTRL		if PROC_FS
480	help
481	  Enable x86 CPU resource control support.
482
483	  Provide support for the allocation and monitoring of system resources
484	  usage by the CPU.
485
486	  Intel calls this Intel Resource Director Technology
487	  (Intel(R) RDT). More information about RDT can be found in the
488	  Intel x86 Architecture Software Developer Manual.
489
490	  AMD calls this AMD Platform Quality of Service (AMD QoS).
491	  More information about AMD QoS can be found in the AMD64 Technology
492	  Platform Quality of Service Extensions manual.
493
494	  Say N if unsure.
495
496if X86_32
497config X86_BIGSMP
498	bool "Support for big SMP systems with more than 8 CPUs"
499	depends on SMP
500	help
501	  This option is needed for the systems that have more than 8 CPUs.
502
503config X86_EXTENDED_PLATFORM
504	bool "Support for extended (non-PC) x86 platforms"
505	default y
506	help
507	  If you disable this option then the kernel will only support
508	  standard PC platforms. (which covers the vast majority of
509	  systems out there.)
510
511	  If you enable this option then you'll be able to select support
512	  for the following (non-PC) 32 bit x86 platforms:
513		Goldfish (Android emulator)
514		AMD Elan
515		RDC R-321x SoC
516		SGI 320/540 (Visual Workstation)
517		STA2X11-based (e.g. Northville)
518		Moorestown MID devices
519
520	  If you have one of these systems, or if you want to build a
521	  generic distribution kernel, say Y here - otherwise say N.
522endif # X86_32
523
524if X86_64
525config X86_EXTENDED_PLATFORM
526	bool "Support for extended (non-PC) x86 platforms"
527	default y
528	help
529	  If you disable this option then the kernel will only support
530	  standard PC platforms. (which covers the vast majority of
531	  systems out there.)
532
533	  If you enable this option then you'll be able to select support
534	  for the following (non-PC) 64 bit x86 platforms:
535		Numascale NumaChip
536		ScaleMP vSMP
537		SGI Ultraviolet
538
539	  If you have one of these systems, or if you want to build a
540	  generic distribution kernel, say Y here - otherwise say N.
541endif # X86_64
542# This is an alphabetically sorted list of 64 bit extended platforms
543# Please maintain the alphabetic order if and when there are additions
544config X86_NUMACHIP
545	bool "Numascale NumaChip"
546	depends on X86_64
547	depends on X86_EXTENDED_PLATFORM
548	depends on NUMA
549	depends on SMP
550	depends on X86_X2APIC
551	depends on PCI_MMCONFIG
552	help
553	  Adds support for Numascale NumaChip large-SMP systems. Needed to
554	  enable more than ~168 cores.
555	  If you don't have one of these, you should say N here.
556
557config X86_VSMP
558	bool "ScaleMP vSMP"
559	select HYPERVISOR_GUEST
560	select PARAVIRT
561	depends on X86_64 && PCI
562	depends on X86_EXTENDED_PLATFORM
563	depends on SMP
564	help
565	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
566	  supposed to run on these EM64T-based machines.  Only choose this option
567	  if you have one of these machines.
568
569config X86_UV
570	bool "SGI Ultraviolet"
571	depends on X86_64
572	depends on X86_EXTENDED_PLATFORM
573	depends on NUMA
574	depends on EFI
575	depends on KEXEC_CORE
576	depends on X86_X2APIC
577	depends on PCI
578	help
579	  This option is needed in order to support SGI Ultraviolet systems.
580	  If you don't have one of these, you should say N here.
581
582# Following is an alphabetically sorted list of 32 bit extended platforms
583# Please maintain the alphabetic order if and when there are additions
584
585config X86_GOLDFISH
586	bool "Goldfish (Virtual Platform)"
587	depends on X86_EXTENDED_PLATFORM
588	help
589	  Enable support for the Goldfish virtual platform used primarily
590	  for Android development. Unless you are building for the Android
591	  Goldfish emulator say N here.
592
593config X86_INTEL_CE
594	bool "CE4100 TV platform"
595	depends on PCI
596	depends on PCI_GODIRECT
597	depends on X86_IO_APIC
598	depends on X86_32
599	depends on X86_EXTENDED_PLATFORM
600	select X86_REBOOTFIXUPS
601	select OF
602	select OF_EARLY_FLATTREE
603	help
604	  Select for the Intel CE media processor (CE4100) SOC.
605	  This option compiles in support for the CE4100 SOC for settop
606	  boxes and media devices.
607
608config X86_INTEL_MID
609	bool "Intel MID platform support"
610	depends on X86_EXTENDED_PLATFORM
611	depends on X86_PLATFORM_DEVICES
612	depends on PCI
613	depends on X86_64 || (PCI_GOANY && X86_32)
614	depends on X86_IO_APIC
615	select I2C
616	select DW_APB_TIMER
617	select INTEL_SCU_PCI
618	help
619	  Select to build a kernel capable of supporting Intel MID (Mobile
620	  Internet Device) platform systems which do not have the PCI legacy
621	  interfaces. If you are building for a PC class system say N here.
622
623	  Intel MID platforms are based on an Intel processor and chipset which
624	  consume less power than most of the x86 derivatives.
625
626config X86_INTEL_QUARK
627	bool "Intel Quark platform support"
628	depends on X86_32
629	depends on X86_EXTENDED_PLATFORM
630	depends on X86_PLATFORM_DEVICES
631	depends on X86_TSC
632	depends on PCI
633	depends on PCI_GOANY
634	depends on X86_IO_APIC
635	select IOSF_MBI
636	select INTEL_IMR
637	select COMMON_CLK
638	help
639	  Select to include support for Quark X1000 SoC.
640	  Say Y here if you have a Quark based system such as the Arduino
641	  compatible Intel Galileo.
642
643config X86_INTEL_LPSS
644	bool "Intel Low Power Subsystem Support"
645	depends on X86 && ACPI && PCI
646	select COMMON_CLK
647	select PINCTRL
648	select IOSF_MBI
649	help
650	  Select to build support for Intel Low Power Subsystem such as
651	  found on Intel Lynxpoint PCH. Selecting this option enables
652	  things like clock tree (common clock framework) and pincontrol
653	  which are needed by the LPSS peripheral drivers.
654
655config X86_AMD_PLATFORM_DEVICE
656	bool "AMD ACPI2Platform devices support"
657	depends on ACPI
658	select COMMON_CLK
659	select PINCTRL
660	help
661	  Select to interpret AMD specific ACPI device to platform device
662	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
663	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
664	  implemented under PINCTRL subsystem.
665
666config IOSF_MBI
667	tristate "Intel SoC IOSF Sideband support for SoC platforms"
668	depends on PCI
669	help
670	  This option enables sideband register access support for Intel SoC
671	  platforms. On these platforms the IOSF sideband is used in lieu of
672	  MSR's for some register accesses, mostly but not limited to thermal
673	  and power. Drivers may query the availability of this device to
674	  determine if they need the sideband in order to work on these
675	  platforms. The sideband is available on the following SoC products.
676	  This list is not meant to be exclusive.
677	   - BayTrail
678	   - Braswell
679	   - Quark
680
681	  You should say Y if you are running a kernel on one of these SoC's.
682
683config IOSF_MBI_DEBUG
684	bool "Enable IOSF sideband access through debugfs"
685	depends on IOSF_MBI && DEBUG_FS
686	help
687	  Select this option to expose the IOSF sideband access registers (MCR,
688	  MDR, MCRX) through debugfs to write and read register information from
689	  different units on the SoC. This is most useful for obtaining device
690	  state information for debug and analysis. As this is a general access
691	  mechanism, users of this option would have specific knowledge of the
692	  device they want to access.
693
694	  If you don't require the option or are in doubt, say N.
695
696config X86_RDC321X
697	bool "RDC R-321x SoC"
698	depends on X86_32
699	depends on X86_EXTENDED_PLATFORM
700	select M486
701	select X86_REBOOTFIXUPS
702	help
703	  This option is needed for RDC R-321x system-on-chip, also known
704	  as R-8610-(G).
705	  If you don't have one of these chips, you should say N here.
706
707config X86_32_NON_STANDARD
708	bool "Support non-standard 32-bit SMP architectures"
709	depends on X86_32 && SMP
710	depends on X86_EXTENDED_PLATFORM
711	help
712	  This option compiles in the bigsmp and STA2X11 default
713	  subarchitectures.  It is intended for a generic binary
714	  kernel. If you select them all, kernel will probe it one by
715	  one and will fallback to default.
716
717# Alphabetically sorted list of Non standard 32 bit platforms
718
719config X86_SUPPORTS_MEMORY_FAILURE
720	def_bool y
721	# MCE code calls memory_failure():
722	depends on X86_MCE
723	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
724	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
725	depends on X86_64 || !SPARSEMEM
726	select ARCH_SUPPORTS_MEMORY_FAILURE
727
728config STA2X11
729	bool "STA2X11 Companion Chip Support"
730	depends on X86_32_NON_STANDARD && PCI
731	select SWIOTLB
732	select MFD_STA2X11
733	select GPIOLIB
734	help
735	  This adds support for boards based on the STA2X11 IO-Hub,
736	  a.k.a. "ConneXt". The chip is used in place of the standard
737	  PC chipset, so all "standard" peripherals are missing. If this
738	  option is selected the kernel will still be able to boot on
739	  standard PC machines.
740
741config X86_32_IRIS
742	tristate "Eurobraille/Iris poweroff module"
743	depends on X86_32
744	help
745	  The Iris machines from EuroBraille do not have APM or ACPI support
746	  to shut themselves down properly.  A special I/O sequence is
747	  needed to do so, which is what this module does at
748	  kernel shutdown.
749
750	  This is only for Iris machines from EuroBraille.
751
752	  If unused, say N.
753
754config SCHED_OMIT_FRAME_POINTER
755	def_bool y
756	prompt "Single-depth WCHAN output"
757	depends on X86
758	help
759	  Calculate simpler /proc/<PID>/wchan values. If this option
760	  is disabled then wchan values will recurse back to the
761	  caller function. This provides more accurate wchan values,
762	  at the expense of slightly more scheduling overhead.
763
764	  If in doubt, say "Y".
765
766menuconfig HYPERVISOR_GUEST
767	bool "Linux guest support"
768	help
769	  Say Y here to enable options for running Linux under various hyper-
770	  visors. This option enables basic hypervisor detection and platform
771	  setup.
772
773	  If you say N, all options in this submenu will be skipped and
774	  disabled, and Linux guest support won't be built in.
775
776if HYPERVISOR_GUEST
777
778config PARAVIRT
779	bool "Enable paravirtualization code"
780	depends on HAVE_STATIC_CALL
781	help
782	  This changes the kernel so it can modify itself when it is run
783	  under a hypervisor, potentially improving performance significantly
784	  over full virtualization.  However, when run without a hypervisor
785	  the kernel is theoretically slower and slightly larger.
786
787config PARAVIRT_XXL
788	bool
789
790config PARAVIRT_DEBUG
791	bool "paravirt-ops debugging"
792	depends on PARAVIRT && DEBUG_KERNEL
793	help
794	  Enable to debug paravirt_ops internals.  Specifically, BUG if
795	  a paravirt_op is missing when it is called.
796
797config PARAVIRT_SPINLOCKS
798	bool "Paravirtualization layer for spinlocks"
799	depends on PARAVIRT && SMP
800	help
801	  Paravirtualized spinlocks allow a pvops backend to replace the
802	  spinlock implementation with something virtualization-friendly
803	  (for example, block the virtual CPU rather than spinning).
804
805	  It has a minimal impact on native kernels and gives a nice performance
806	  benefit on paravirtualized KVM / Xen kernels.
807
808	  If you are unsure how to answer this question, answer Y.
809
810config X86_HV_CALLBACK_VECTOR
811	def_bool n
812
813source "arch/x86/xen/Kconfig"
814
815config KVM_GUEST
816	bool "KVM Guest support (including kvmclock)"
817	depends on PARAVIRT
818	select PARAVIRT_CLOCK
819	select ARCH_CPUIDLE_HALTPOLL
820	select X86_HV_CALLBACK_VECTOR
821	default y
822	help
823	  This option enables various optimizations for running under the KVM
824	  hypervisor. It includes a paravirtualized clock, so that instead
825	  of relying on a PIT (or probably other) emulation by the
826	  underlying device model, the host provides the guest with
827	  timing infrastructure such as time of day, and system time
828
829config ARCH_CPUIDLE_HALTPOLL
830	def_bool n
831	prompt "Disable host haltpoll when loading haltpoll driver"
832	help
833	  If virtualized under KVM, disable host haltpoll.
834
835config PVH
836	bool "Support for running PVH guests"
837	help
838	  This option enables the PVH entry point for guest virtual machines
839	  as specified in the x86/HVM direct boot ABI.
840
841config PARAVIRT_TIME_ACCOUNTING
842	bool "Paravirtual steal time accounting"
843	depends on PARAVIRT
844	help
845	  Select this option to enable fine granularity task steal time
846	  accounting. Time spent executing other tasks in parallel with
847	  the current vCPU is discounted from the vCPU power. To account for
848	  that, there can be a small performance impact.
849
850	  If in doubt, say N here.
851
852config PARAVIRT_CLOCK
853	bool
854
855config JAILHOUSE_GUEST
856	bool "Jailhouse non-root cell support"
857	depends on X86_64 && PCI
858	select X86_PM_TIMER
859	help
860	  This option allows to run Linux as guest in a Jailhouse non-root
861	  cell. You can leave this option disabled if you only want to start
862	  Jailhouse and run Linux afterwards in the root cell.
863
864config ACRN_GUEST
865	bool "ACRN Guest support"
866	depends on X86_64
867	select X86_HV_CALLBACK_VECTOR
868	help
869	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
870	  a flexible, lightweight reference open-source hypervisor, built with
871	  real-time and safety-criticality in mind. It is built for embedded
872	  IOT with small footprint and real-time features. More details can be
873	  found in https://projectacrn.org/.
874
875config INTEL_TDX_GUEST
876	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
877	depends on X86_64 && CPU_SUP_INTEL
878	depends on X86_X2APIC
879	depends on EFI_STUB
880	select ARCH_HAS_CC_PLATFORM
881	select X86_MEM_ENCRYPT
882	select X86_MCE
883	select UNACCEPTED_MEMORY
884	help
885	  Support running as a guest under Intel TDX.  Without this support,
886	  the guest kernel can not boot or run under TDX.
887	  TDX includes memory encryption and integrity capabilities
888	  which protect the confidentiality and integrity of guest
889	  memory contents and CPU state. TDX guests are protected from
890	  some attacks from the VMM.
891
892endif # HYPERVISOR_GUEST
893
894source "arch/x86/Kconfig.cpu"
895
896config HPET_TIMER
897	def_bool X86_64
898	prompt "HPET Timer Support" if X86_32
899	help
900	  Use the IA-PC HPET (High Precision Event Timer) to manage
901	  time in preference to the PIT and RTC, if a HPET is
902	  present.
903	  HPET is the next generation timer replacing legacy 8254s.
904	  The HPET provides a stable time base on SMP
905	  systems, unlike the TSC, but it is more expensive to access,
906	  as it is off-chip.  The interface used is documented
907	  in the HPET spec, revision 1.
908
909	  You can safely choose Y here.  However, HPET will only be
910	  activated if the platform and the BIOS support this feature.
911	  Otherwise the 8254 will be used for timing services.
912
913	  Choose N to continue using the legacy 8254 timer.
914
915config HPET_EMULATE_RTC
916	def_bool y
917	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
918
919# Mark as expert because too many people got it wrong.
920# The code disables itself when not needed.
921config DMI
922	default y
923	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
924	bool "Enable DMI scanning" if EXPERT
925	help
926	  Enabled scanning of DMI to identify machine quirks. Say Y
927	  here unless you have verified that your setup is not
928	  affected by entries in the DMI blacklist. Required by PNP
929	  BIOS code.
930
931config GART_IOMMU
932	bool "Old AMD GART IOMMU support"
933	select DMA_OPS
934	select IOMMU_HELPER
935	select SWIOTLB
936	depends on X86_64 && PCI && AMD_NB
937	help
938	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
939	  GART based hardware IOMMUs.
940
941	  The GART supports full DMA access for devices with 32-bit access
942	  limitations, on systems with more than 3 GB. This is usually needed
943	  for USB, sound, many IDE/SATA chipsets and some other devices.
944
945	  Newer systems typically have a modern AMD IOMMU, supported via
946	  the CONFIG_AMD_IOMMU=y config option.
947
948	  In normal configurations this driver is only active when needed:
949	  there's more than 3 GB of memory and the system contains a
950	  32-bit limited device.
951
952	  If unsure, say Y.
953
954config BOOT_VESA_SUPPORT
955	bool
956	help
957	  If true, at least one selected framebuffer driver can take advantage
958	  of VESA video modes set at an early boot stage via the vga= parameter.
959
960config MAXSMP
961	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
962	depends on X86_64 && SMP && DEBUG_KERNEL
963	select CPUMASK_OFFSTACK
964	help
965	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
966	  If unsure, say N.
967
968#
969# The maximum number of CPUs supported:
970#
971# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
972# and which can be configured interactively in the
973# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
974#
975# The ranges are different on 32-bit and 64-bit kernels, depending on
976# hardware capabilities and scalability features of the kernel.
977#
978# ( If MAXSMP is enabled we just use the highest possible value and disable
979#   interactive configuration. )
980#
981
982config NR_CPUS_RANGE_BEGIN
983	int
984	default NR_CPUS_RANGE_END if MAXSMP
985	default    1 if !SMP
986	default    2
987
988config NR_CPUS_RANGE_END
989	int
990	depends on X86_32
991	default   64 if  SMP &&  X86_BIGSMP
992	default    8 if  SMP && !X86_BIGSMP
993	default    1 if !SMP
994
995config NR_CPUS_RANGE_END
996	int
997	depends on X86_64
998	default 8192 if  SMP && CPUMASK_OFFSTACK
999	default  512 if  SMP && !CPUMASK_OFFSTACK
1000	default    1 if !SMP
1001
1002config NR_CPUS_DEFAULT
1003	int
1004	depends on X86_32
1005	default   32 if  X86_BIGSMP
1006	default    8 if  SMP
1007	default    1 if !SMP
1008
1009config NR_CPUS_DEFAULT
1010	int
1011	depends on X86_64
1012	default 8192 if  MAXSMP
1013	default   64 if  SMP
1014	default    1 if !SMP
1015
1016config NR_CPUS
1017	int "Maximum number of CPUs" if SMP && !MAXSMP
1018	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1019	default NR_CPUS_DEFAULT
1020	help
1021	  This allows you to specify the maximum number of CPUs which this
1022	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1023	  supported value is 8192, otherwise the maximum value is 512.  The
1024	  minimum value which makes sense is 2.
1025
1026	  This is purely to save memory: each supported CPU adds about 8KB
1027	  to the kernel image.
1028
1029config SCHED_CLUSTER
1030	bool "Cluster scheduler support"
1031	depends on SMP
1032	default y
1033	help
1034	  Cluster scheduler support improves the CPU scheduler's decision
1035	  making when dealing with machines that have clusters of CPUs.
1036	  Cluster usually means a couple of CPUs which are placed closely
1037	  by sharing mid-level caches, last-level cache tags or internal
1038	  busses.
1039
1040config SCHED_SMT
1041	def_bool y if SMP
1042
1043config SCHED_MC
1044	def_bool y
1045	prompt "Multi-core scheduler support"
1046	depends on SMP
1047	help
1048	  Multi-core scheduler support improves the CPU scheduler's decision
1049	  making when dealing with multi-core CPU chips at a cost of slightly
1050	  increased overhead in some places. If unsure say N here.
1051
1052config SCHED_MC_PRIO
1053	bool "CPU core priorities scheduler support"
1054	depends on SCHED_MC && CPU_SUP_INTEL
1055	select X86_INTEL_PSTATE
1056	select CPU_FREQ
1057	default y
1058	help
1059	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1060	  core ordering determined at manufacturing time, which allows
1061	  certain cores to reach higher turbo frequencies (when running
1062	  single threaded workloads) than others.
1063
1064	  Enabling this kernel feature teaches the scheduler about
1065	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1066	  scheduler's CPU selection logic accordingly, so that higher
1067	  overall system performance can be achieved.
1068
1069	  This feature will have no effect on CPUs without this feature.
1070
1071	  If unsure say Y here.
1072
1073config UP_LATE_INIT
1074	def_bool y
1075	depends on !SMP && X86_LOCAL_APIC
1076
1077config X86_UP_APIC
1078	bool "Local APIC support on uniprocessors" if !PCI_MSI
1079	default PCI_MSI
1080	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1081	help
1082	  A local APIC (Advanced Programmable Interrupt Controller) is an
1083	  integrated interrupt controller in the CPU. If you have a single-CPU
1084	  system which has a processor with a local APIC, you can say Y here to
1085	  enable and use it. If you say Y here even though your machine doesn't
1086	  have a local APIC, then the kernel will still run with no slowdown at
1087	  all. The local APIC supports CPU-generated self-interrupts (timer,
1088	  performance counters), and the NMI watchdog which detects hard
1089	  lockups.
1090
1091config X86_UP_IOAPIC
1092	bool "IO-APIC support on uniprocessors"
1093	depends on X86_UP_APIC
1094	help
1095	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1096	  SMP-capable replacement for PC-style interrupt controllers. Most
1097	  SMP systems and many recent uniprocessor systems have one.
1098
1099	  If you have a single-CPU system with an IO-APIC, you can say Y here
1100	  to use it. If you say Y here even though your machine doesn't have
1101	  an IO-APIC, then the kernel will still run with no slowdown at all.
1102
1103config X86_LOCAL_APIC
1104	def_bool y
1105	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1106	select IRQ_DOMAIN_HIERARCHY
1107
1108config X86_IO_APIC
1109	def_bool y
1110	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1111
1112config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1113	bool "Reroute for broken boot IRQs"
1114	depends on X86_IO_APIC
1115	help
1116	  This option enables a workaround that fixes a source of
1117	  spurious interrupts. This is recommended when threaded
1118	  interrupt handling is used on systems where the generation of
1119	  superfluous "boot interrupts" cannot be disabled.
1120
1121	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1122	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1123	  kernel does during interrupt handling). On chipsets where this
1124	  boot IRQ generation cannot be disabled, this workaround keeps
1125	  the original IRQ line masked so that only the equivalent "boot
1126	  IRQ" is delivered to the CPUs. The workaround also tells the
1127	  kernel to set up the IRQ handler on the boot IRQ line. In this
1128	  way only one interrupt is delivered to the kernel. Otherwise
1129	  the spurious second interrupt may cause the kernel to bring
1130	  down (vital) interrupt lines.
1131
1132	  Only affects "broken" chipsets. Interrupt sharing may be
1133	  increased on these systems.
1134
1135config X86_MCE
1136	bool "Machine Check / overheating reporting"
1137	select GENERIC_ALLOCATOR
1138	default y
1139	help
1140	  Machine Check support allows the processor to notify the
1141	  kernel if it detects a problem (e.g. overheating, data corruption).
1142	  The action the kernel takes depends on the severity of the problem,
1143	  ranging from warning messages to halting the machine.
1144
1145config X86_MCELOG_LEGACY
1146	bool "Support for deprecated /dev/mcelog character device"
1147	depends on X86_MCE
1148	help
1149	  Enable support for /dev/mcelog which is needed by the old mcelog
1150	  userspace logging daemon. Consider switching to the new generation
1151	  rasdaemon solution.
1152
1153config X86_MCE_INTEL
1154	def_bool y
1155	prompt "Intel MCE features"
1156	depends on X86_MCE && X86_LOCAL_APIC
1157	help
1158	  Additional support for intel specific MCE features such as
1159	  the thermal monitor.
1160
1161config X86_MCE_AMD
1162	def_bool y
1163	prompt "AMD MCE features"
1164	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1165	help
1166	  Additional support for AMD specific MCE features such as
1167	  the DRAM Error Threshold.
1168
1169config X86_ANCIENT_MCE
1170	bool "Support for old Pentium 5 / WinChip machine checks"
1171	depends on X86_32 && X86_MCE
1172	help
1173	  Include support for machine check handling on old Pentium 5 or WinChip
1174	  systems. These typically need to be enabled explicitly on the command
1175	  line.
1176
1177config X86_MCE_THRESHOLD
1178	depends on X86_MCE_AMD || X86_MCE_INTEL
1179	def_bool y
1180
1181config X86_MCE_INJECT
1182	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1183	tristate "Machine check injector support"
1184	help
1185	  Provide support for injecting machine checks for testing purposes.
1186	  If you don't know what a machine check is and you don't do kernel
1187	  QA it is safe to say n.
1188
1189source "arch/x86/events/Kconfig"
1190
1191config X86_LEGACY_VM86
1192	bool "Legacy VM86 support"
1193	depends on X86_32
1194	help
1195	  This option allows user programs to put the CPU into V8086
1196	  mode, which is an 80286-era approximation of 16-bit real mode.
1197
1198	  Some very old versions of X and/or vbetool require this option
1199	  for user mode setting.  Similarly, DOSEMU will use it if
1200	  available to accelerate real mode DOS programs.  However, any
1201	  recent version of DOSEMU, X, or vbetool should be fully
1202	  functional even without kernel VM86 support, as they will all
1203	  fall back to software emulation. Nevertheless, if you are using
1204	  a 16-bit DOS program where 16-bit performance matters, vm86
1205	  mode might be faster than emulation and you might want to
1206	  enable this option.
1207
1208	  Note that any app that works on a 64-bit kernel is unlikely to
1209	  need this option, as 64-bit kernels don't, and can't, support
1210	  V8086 mode. This option is also unrelated to 16-bit protected
1211	  mode and is not needed to run most 16-bit programs under Wine.
1212
1213	  Enabling this option increases the complexity of the kernel
1214	  and slows down exception handling a tiny bit.
1215
1216	  If unsure, say N here.
1217
1218config VM86
1219	bool
1220	default X86_LEGACY_VM86
1221
1222config X86_16BIT
1223	bool "Enable support for 16-bit segments" if EXPERT
1224	default y
1225	depends on MODIFY_LDT_SYSCALL
1226	help
1227	  This option is required by programs like Wine to run 16-bit
1228	  protected mode legacy code on x86 processors.  Disabling
1229	  this option saves about 300 bytes on i386, or around 6K text
1230	  plus 16K runtime memory on x86-64,
1231
1232config X86_ESPFIX32
1233	def_bool y
1234	depends on X86_16BIT && X86_32
1235
1236config X86_ESPFIX64
1237	def_bool y
1238	depends on X86_16BIT && X86_64
1239
1240config X86_VSYSCALL_EMULATION
1241	bool "Enable vsyscall emulation" if EXPERT
1242	default y
1243	depends on X86_64
1244	help
1245	  This enables emulation of the legacy vsyscall page.  Disabling
1246	  it is roughly equivalent to booting with vsyscall=none, except
1247	  that it will also disable the helpful warning if a program
1248	  tries to use a vsyscall.  With this option set to N, offending
1249	  programs will just segfault, citing addresses of the form
1250	  0xffffffffff600?00.
1251
1252	  This option is required by many programs built before 2013, and
1253	  care should be used even with newer programs if set to N.
1254
1255	  Disabling this option saves about 7K of kernel size and
1256	  possibly 4K of additional runtime pagetable memory.
1257
1258config X86_IOPL_IOPERM
1259	bool "IOPERM and IOPL Emulation"
1260	default y
1261	help
1262	  This enables the ioperm() and iopl() syscalls which are necessary
1263	  for legacy applications.
1264
1265	  Legacy IOPL support is an overbroad mechanism which allows user
1266	  space aside of accessing all 65536 I/O ports also to disable
1267	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1268	  capabilities and permission from potentially active security
1269	  modules.
1270
1271	  The emulation restricts the functionality of the syscall to
1272	  only allowing the full range I/O port access, but prevents the
1273	  ability to disable interrupts from user space which would be
1274	  granted if the hardware IOPL mechanism would be used.
1275
1276config TOSHIBA
1277	tristate "Toshiba Laptop support"
1278	depends on X86_32
1279	help
1280	  This adds a driver to safely access the System Management Mode of
1281	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1282	  not work on models with a Phoenix BIOS. The System Management Mode
1283	  is used to set the BIOS and power saving options on Toshiba portables.
1284
1285	  For information on utilities to make use of this driver see the
1286	  Toshiba Linux utilities web site at:
1287	  <http://www.buzzard.org.uk/toshiba/>.
1288
1289	  Say Y if you intend to run this kernel on a Toshiba portable.
1290	  Say N otherwise.
1291
1292config X86_REBOOTFIXUPS
1293	bool "Enable X86 board specific fixups for reboot"
1294	depends on X86_32
1295	help
1296	  This enables chipset and/or board specific fixups to be done
1297	  in order to get reboot to work correctly. This is only needed on
1298	  some combinations of hardware and BIOS. The symptom, for which
1299	  this config is intended, is when reboot ends with a stalled/hung
1300	  system.
1301
1302	  Currently, the only fixup is for the Geode machines using
1303	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1304
1305	  Say Y if you want to enable the fixup. Currently, it's safe to
1306	  enable this option even if you don't need it.
1307	  Say N otherwise.
1308
1309config MICROCODE
1310	bool "CPU microcode loading support"
1311	default y
1312	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1313	help
1314	  If you say Y here, you will be able to update the microcode on
1315	  Intel and AMD processors. The Intel support is for the IA32 family,
1316	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1317	  AMD support is for families 0x10 and later. You will obviously need
1318	  the actual microcode binary data itself which is not shipped with
1319	  the Linux kernel.
1320
1321	  The preferred method to load microcode from a detached initrd is described
1322	  in Documentation/arch/x86/microcode.rst. For that you need to enable
1323	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1324	  initrd for microcode blobs.
1325
1326	  In addition, you can build the microcode into the kernel. For that you
1327	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1328	  config option.
1329
1330config MICROCODE_INTEL
1331	bool "Intel microcode loading support"
1332	depends on CPU_SUP_INTEL && MICROCODE
1333	default MICROCODE
1334	help
1335	  This options enables microcode patch loading support for Intel
1336	  processors.
1337
1338	  For the current Intel microcode data package go to
1339	  <https://downloadcenter.intel.com> and search for
1340	  'Linux Processor Microcode Data File'.
1341
1342config MICROCODE_AMD
1343	bool "AMD microcode loading support"
1344	depends on CPU_SUP_AMD && MICROCODE
1345	help
1346	  If you select this option, microcode patch loading support for AMD
1347	  processors will be enabled.
1348
1349config MICROCODE_LATE_LOADING
1350	bool "Late microcode loading (DANGEROUS)"
1351	default n
1352	depends on MICROCODE
1353	help
1354	  Loading microcode late, when the system is up and executing instructions
1355	  is a tricky business and should be avoided if possible. Just the sequence
1356	  of synchronizing all cores and SMT threads is one fragile dance which does
1357	  not guarantee that cores might not softlock after the loading. Therefore,
1358	  use this at your own risk. Late loading taints the kernel too.
1359
1360config X86_MSR
1361	tristate "/dev/cpu/*/msr - Model-specific register support"
1362	help
1363	  This device gives privileged processes access to the x86
1364	  Model-Specific Registers (MSRs).  It is a character device with
1365	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1366	  MSR accesses are directed to a specific CPU on multi-processor
1367	  systems.
1368
1369config X86_CPUID
1370	tristate "/dev/cpu/*/cpuid - CPU information support"
1371	help
1372	  This device gives processes access to the x86 CPUID instruction to
1373	  be executed on a specific processor.  It is a character device
1374	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1375	  /dev/cpu/31/cpuid.
1376
1377choice
1378	prompt "High Memory Support"
1379	default HIGHMEM4G
1380	depends on X86_32
1381
1382config NOHIGHMEM
1383	bool "off"
1384	help
1385	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1386	  However, the address space of 32-bit x86 processors is only 4
1387	  Gigabytes large. That means that, if you have a large amount of
1388	  physical memory, not all of it can be "permanently mapped" by the
1389	  kernel. The physical memory that's not permanently mapped is called
1390	  "high memory".
1391
1392	  If you are compiling a kernel which will never run on a machine with
1393	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1394	  choice and suitable for most users). This will result in a "3GB/1GB"
1395	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1396	  space and the remaining part of the 4GB virtual memory space is used
1397	  by the kernel to permanently map as much physical memory as
1398	  possible.
1399
1400	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1401	  answer "4GB" here.
1402
1403	  If more than 4 Gigabytes is used then answer "64GB" here. This
1404	  selection turns Intel PAE (Physical Address Extension) mode on.
1405	  PAE implements 3-level paging on IA32 processors. PAE is fully
1406	  supported by Linux, PAE mode is implemented on all recent Intel
1407	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1408	  then the kernel will not boot on CPUs that don't support PAE!
1409
1410	  The actual amount of total physical memory will either be
1411	  auto detected or can be forced by using a kernel command line option
1412	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1413	  your boot loader (lilo or loadlin) about how to pass options to the
1414	  kernel at boot time.)
1415
1416	  If unsure, say "off".
1417
1418config HIGHMEM4G
1419	bool "4GB"
1420	help
1421	  Select this if you have a 32-bit processor and between 1 and 4
1422	  gigabytes of physical RAM.
1423
1424config HIGHMEM64G
1425	bool "64GB"
1426	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1427	select X86_PAE
1428	help
1429	  Select this if you have a 32-bit processor and more than 4
1430	  gigabytes of physical RAM.
1431
1432endchoice
1433
1434choice
1435	prompt "Memory split" if EXPERT
1436	default VMSPLIT_3G
1437	depends on X86_32
1438	help
1439	  Select the desired split between kernel and user memory.
1440
1441	  If the address range available to the kernel is less than the
1442	  physical memory installed, the remaining memory will be available
1443	  as "high memory". Accessing high memory is a little more costly
1444	  than low memory, as it needs to be mapped into the kernel first.
1445	  Note that increasing the kernel address space limits the range
1446	  available to user programs, making the address space there
1447	  tighter.  Selecting anything other than the default 3G/1G split
1448	  will also likely make your kernel incompatible with binary-only
1449	  kernel modules.
1450
1451	  If you are not absolutely sure what you are doing, leave this
1452	  option alone!
1453
1454	config VMSPLIT_3G
1455		bool "3G/1G user/kernel split"
1456	config VMSPLIT_3G_OPT
1457		depends on !X86_PAE
1458		bool "3G/1G user/kernel split (for full 1G low memory)"
1459	config VMSPLIT_2G
1460		bool "2G/2G user/kernel split"
1461	config VMSPLIT_2G_OPT
1462		depends on !X86_PAE
1463		bool "2G/2G user/kernel split (for full 2G low memory)"
1464	config VMSPLIT_1G
1465		bool "1G/3G user/kernel split"
1466endchoice
1467
1468config PAGE_OFFSET
1469	hex
1470	default 0xB0000000 if VMSPLIT_3G_OPT
1471	default 0x80000000 if VMSPLIT_2G
1472	default 0x78000000 if VMSPLIT_2G_OPT
1473	default 0x40000000 if VMSPLIT_1G
1474	default 0xC0000000
1475	depends on X86_32
1476
1477config HIGHMEM
1478	def_bool y
1479	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1480
1481config X86_PAE
1482	bool "PAE (Physical Address Extension) Support"
1483	depends on X86_32 && !HIGHMEM4G
1484	select PHYS_ADDR_T_64BIT
1485	select SWIOTLB
1486	help
1487	  PAE is required for NX support, and furthermore enables
1488	  larger swapspace support for non-overcommit purposes. It
1489	  has the cost of more pagetable lookup overhead, and also
1490	  consumes more pagetable space per process.
1491
1492config X86_5LEVEL
1493	bool "Enable 5-level page tables support"
1494	default y
1495	select DYNAMIC_MEMORY_LAYOUT
1496	select SPARSEMEM_VMEMMAP
1497	depends on X86_64
1498	help
1499	  5-level paging enables access to larger address space:
1500	  up to 128 PiB of virtual address space and 4 PiB of
1501	  physical address space.
1502
1503	  It will be supported by future Intel CPUs.
1504
1505	  A kernel with the option enabled can be booted on machines that
1506	  support 4- or 5-level paging.
1507
1508	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1509	  information.
1510
1511	  Say N if unsure.
1512
1513config X86_DIRECT_GBPAGES
1514	def_bool y
1515	depends on X86_64
1516	help
1517	  Certain kernel features effectively disable kernel
1518	  linear 1 GB mappings (even if the CPU otherwise
1519	  supports them), so don't confuse the user by printing
1520	  that we have them enabled.
1521
1522config X86_CPA_STATISTICS
1523	bool "Enable statistic for Change Page Attribute"
1524	depends on DEBUG_FS
1525	help
1526	  Expose statistics about the Change Page Attribute mechanism, which
1527	  helps to determine the effectiveness of preserving large and huge
1528	  page mappings when mapping protections are changed.
1529
1530config X86_MEM_ENCRYPT
1531	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1532	select DYNAMIC_PHYSICAL_MASK
1533	def_bool n
1534
1535config AMD_MEM_ENCRYPT
1536	bool "AMD Secure Memory Encryption (SME) support"
1537	depends on X86_64 && CPU_SUP_AMD
1538	depends on EFI_STUB
1539	select DMA_COHERENT_POOL
1540	select ARCH_USE_MEMREMAP_PROT
1541	select INSTRUCTION_DECODER
1542	select ARCH_HAS_CC_PLATFORM
1543	select X86_MEM_ENCRYPT
1544	select UNACCEPTED_MEMORY
1545	help
1546	  Say yes to enable support for the encryption of system memory.
1547	  This requires an AMD processor that supports Secure Memory
1548	  Encryption (SME).
1549
1550config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1551	bool "Activate AMD Secure Memory Encryption (SME) by default"
1552	depends on AMD_MEM_ENCRYPT
1553	help
1554	  Say yes to have system memory encrypted by default if running on
1555	  an AMD processor that supports Secure Memory Encryption (SME).
1556
1557	  If set to Y, then the encryption of system memory can be
1558	  deactivated with the mem_encrypt=off command line option.
1559
1560	  If set to N, then the encryption of system memory can be
1561	  activated with the mem_encrypt=on command line option.
1562
1563# Common NUMA Features
1564config NUMA
1565	bool "NUMA Memory Allocation and Scheduler Support"
1566	depends on SMP
1567	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1568	default y if X86_BIGSMP
1569	select USE_PERCPU_NUMA_NODE_ID
1570	help
1571	  Enable NUMA (Non-Uniform Memory Access) support.
1572
1573	  The kernel will try to allocate memory used by a CPU on the
1574	  local memory controller of the CPU and add some more
1575	  NUMA awareness to the kernel.
1576
1577	  For 64-bit this is recommended if the system is Intel Core i7
1578	  (or later), AMD Opteron, or EM64T NUMA.
1579
1580	  For 32-bit this is only needed if you boot a 32-bit
1581	  kernel on a 64-bit NUMA platform.
1582
1583	  Otherwise, you should say N.
1584
1585config AMD_NUMA
1586	def_bool y
1587	prompt "Old style AMD Opteron NUMA detection"
1588	depends on X86_64 && NUMA && PCI
1589	help
1590	  Enable AMD NUMA node topology detection.  You should say Y here if
1591	  you have a multi processor AMD system. This uses an old method to
1592	  read the NUMA configuration directly from the builtin Northbridge
1593	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1594	  which also takes priority if both are compiled in.
1595
1596config X86_64_ACPI_NUMA
1597	def_bool y
1598	prompt "ACPI NUMA detection"
1599	depends on X86_64 && NUMA && ACPI && PCI
1600	select ACPI_NUMA
1601	help
1602	  Enable ACPI SRAT based node topology detection.
1603
1604config NUMA_EMU
1605	bool "NUMA emulation"
1606	depends on NUMA
1607	help
1608	  Enable NUMA emulation. A flat machine will be split
1609	  into virtual nodes when booted with "numa=fake=N", where N is the
1610	  number of nodes. This is only useful for debugging.
1611
1612config NODES_SHIFT
1613	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1614	range 1 10
1615	default "10" if MAXSMP
1616	default "6" if X86_64
1617	default "3"
1618	depends on NUMA
1619	help
1620	  Specify the maximum number of NUMA Nodes available on the target
1621	  system.  Increases memory reserved to accommodate various tables.
1622
1623config ARCH_FLATMEM_ENABLE
1624	def_bool y
1625	depends on X86_32 && !NUMA
1626
1627config ARCH_SPARSEMEM_ENABLE
1628	def_bool y
1629	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1630	select SPARSEMEM_STATIC if X86_32
1631	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1632
1633config ARCH_SPARSEMEM_DEFAULT
1634	def_bool X86_64 || (NUMA && X86_32)
1635
1636config ARCH_SELECT_MEMORY_MODEL
1637	def_bool y
1638	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1639
1640config ARCH_MEMORY_PROBE
1641	bool "Enable sysfs memory/probe interface"
1642	depends on MEMORY_HOTPLUG
1643	help
1644	  This option enables a sysfs memory/probe interface for testing.
1645	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1646	  If you are unsure how to answer this question, answer N.
1647
1648config ARCH_PROC_KCORE_TEXT
1649	def_bool y
1650	depends on X86_64 && PROC_KCORE
1651
1652config ILLEGAL_POINTER_VALUE
1653	hex
1654	default 0 if X86_32
1655	default 0xdead000000000000 if X86_64
1656
1657config X86_PMEM_LEGACY_DEVICE
1658	bool
1659
1660config X86_PMEM_LEGACY
1661	tristate "Support non-standard NVDIMMs and ADR protected memory"
1662	depends on PHYS_ADDR_T_64BIT
1663	depends on BLK_DEV
1664	select X86_PMEM_LEGACY_DEVICE
1665	select NUMA_KEEP_MEMINFO if NUMA
1666	select LIBNVDIMM
1667	help
1668	  Treat memory marked using the non-standard e820 type of 12 as used
1669	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1670	  The kernel will offer these regions to the 'pmem' driver so
1671	  they can be used for persistent storage.
1672
1673	  Say Y if unsure.
1674
1675config HIGHPTE
1676	bool "Allocate 3rd-level pagetables from highmem"
1677	depends on HIGHMEM
1678	help
1679	  The VM uses one page table entry for each page of physical memory.
1680	  For systems with a lot of RAM, this can be wasteful of precious
1681	  low memory.  Setting this option will put user-space page table
1682	  entries in high memory.
1683
1684config X86_CHECK_BIOS_CORRUPTION
1685	bool "Check for low memory corruption"
1686	help
1687	  Periodically check for memory corruption in low memory, which
1688	  is suspected to be caused by BIOS.  Even when enabled in the
1689	  configuration, it is disabled at runtime.  Enable it by
1690	  setting "memory_corruption_check=1" on the kernel command
1691	  line.  By default it scans the low 64k of memory every 60
1692	  seconds; see the memory_corruption_check_size and
1693	  memory_corruption_check_period parameters in
1694	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1695
1696	  When enabled with the default parameters, this option has
1697	  almost no overhead, as it reserves a relatively small amount
1698	  of memory and scans it infrequently.  It both detects corruption
1699	  and prevents it from affecting the running system.
1700
1701	  It is, however, intended as a diagnostic tool; if repeatable
1702	  BIOS-originated corruption always affects the same memory,
1703	  you can use memmap= to prevent the kernel from using that
1704	  memory.
1705
1706config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1707	bool "Set the default setting of memory_corruption_check"
1708	depends on X86_CHECK_BIOS_CORRUPTION
1709	default y
1710	help
1711	  Set whether the default state of memory_corruption_check is
1712	  on or off.
1713
1714config MATH_EMULATION
1715	bool
1716	depends on MODIFY_LDT_SYSCALL
1717	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1718	help
1719	  Linux can emulate a math coprocessor (used for floating point
1720	  operations) if you don't have one. 486DX and Pentium processors have
1721	  a math coprocessor built in, 486SX and 386 do not, unless you added
1722	  a 487DX or 387, respectively. (The messages during boot time can
1723	  give you some hints here ["man dmesg"].) Everyone needs either a
1724	  coprocessor or this emulation.
1725
1726	  If you don't have a math coprocessor, you need to say Y here; if you
1727	  say Y here even though you have a coprocessor, the coprocessor will
1728	  be used nevertheless. (This behavior can be changed with the kernel
1729	  command line option "no387", which comes handy if your coprocessor
1730	  is broken. Try "man bootparam" or see the documentation of your boot
1731	  loader (lilo or loadlin) about how to pass options to the kernel at
1732	  boot time.) This means that it is a good idea to say Y here if you
1733	  intend to use this kernel on different machines.
1734
1735	  More information about the internals of the Linux math coprocessor
1736	  emulation can be found in <file:arch/x86/math-emu/README>.
1737
1738	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1739	  kernel, it won't hurt.
1740
1741config MTRR
1742	def_bool y
1743	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1744	help
1745	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1746	  the Memory Type Range Registers (MTRRs) may be used to control
1747	  processor access to memory ranges. This is most useful if you have
1748	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1749	  allows bus write transfers to be combined into a larger transfer
1750	  before bursting over the PCI/AGP bus. This can increase performance
1751	  of image write operations 2.5 times or more. Saying Y here creates a
1752	  /proc/mtrr file which may be used to manipulate your processor's
1753	  MTRRs. Typically the X server should use this.
1754
1755	  This code has a reasonably generic interface so that similar
1756	  control registers on other processors can be easily supported
1757	  as well:
1758
1759	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1760	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1761	  these, the ARRs are used to emulate the MTRRs.
1762	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1763	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1764	  write-combining. All of these processors are supported by this code
1765	  and it makes sense to say Y here if you have one of them.
1766
1767	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1768	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1769	  can lead to all sorts of problems, so it's good to say Y here.
1770
1771	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1772	  just add about 9 KB to your kernel.
1773
1774	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1775
1776config MTRR_SANITIZER
1777	def_bool y
1778	prompt "MTRR cleanup support"
1779	depends on MTRR
1780	help
1781	  Convert MTRR layout from continuous to discrete, so X drivers can
1782	  add writeback entries.
1783
1784	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1785	  The largest mtrr entry size for a continuous block can be set with
1786	  mtrr_chunk_size.
1787
1788	  If unsure, say Y.
1789
1790config MTRR_SANITIZER_ENABLE_DEFAULT
1791	int "MTRR cleanup enable value (0-1)"
1792	range 0 1
1793	default "0"
1794	depends on MTRR_SANITIZER
1795	help
1796	  Enable mtrr cleanup default value
1797
1798config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1799	int "MTRR cleanup spare reg num (0-7)"
1800	range 0 7
1801	default "1"
1802	depends on MTRR_SANITIZER
1803	help
1804	  mtrr cleanup spare entries default, it can be changed via
1805	  mtrr_spare_reg_nr=N on the kernel command line.
1806
1807config X86_PAT
1808	def_bool y
1809	prompt "x86 PAT support" if EXPERT
1810	depends on MTRR
1811	help
1812	  Use PAT attributes to setup page level cache control.
1813
1814	  PATs are the modern equivalents of MTRRs and are much more
1815	  flexible than MTRRs.
1816
1817	  Say N here if you see bootup problems (boot crash, boot hang,
1818	  spontaneous reboots) or a non-working video driver.
1819
1820	  If unsure, say Y.
1821
1822config ARCH_USES_PG_UNCACHED
1823	def_bool y
1824	depends on X86_PAT
1825
1826config X86_UMIP
1827	def_bool y
1828	prompt "User Mode Instruction Prevention" if EXPERT
1829	help
1830	  User Mode Instruction Prevention (UMIP) is a security feature in
1831	  some x86 processors. If enabled, a general protection fault is
1832	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1833	  executed in user mode. These instructions unnecessarily expose
1834	  information about the hardware state.
1835
1836	  The vast majority of applications do not use these instructions.
1837	  For the very few that do, software emulation is provided in
1838	  specific cases in protected and virtual-8086 modes. Emulated
1839	  results are dummy.
1840
1841config CC_HAS_IBT
1842	# GCC >= 9 and binutils >= 2.29
1843	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1844	# Clang/LLVM >= 14
1845	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1846	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1847	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1848		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1849		  $(as-instr,endbr64)
1850
1851config X86_KERNEL_IBT
1852	prompt "Indirect Branch Tracking"
1853	def_bool y
1854	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1855	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1856	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1857	select OBJTOOL
1858	help
1859	  Build the kernel with support for Indirect Branch Tracking, a
1860	  hardware support course-grain forward-edge Control Flow Integrity
1861	  protection. It enforces that all indirect calls must land on
1862	  an ENDBR instruction, as such, the compiler will instrument the
1863	  code with them to make this happen.
1864
1865	  In addition to building the kernel with IBT, seal all functions that
1866	  are not indirect call targets, avoiding them ever becoming one.
1867
1868	  This requires LTO like objtool runs and will slow down the build. It
1869	  does significantly reduce the number of ENDBR instructions in the
1870	  kernel image.
1871
1872config X86_INTEL_MEMORY_PROTECTION_KEYS
1873	prompt "Memory Protection Keys"
1874	def_bool y
1875	# Note: only available in 64-bit mode
1876	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1877	select ARCH_USES_HIGH_VMA_FLAGS
1878	select ARCH_HAS_PKEYS
1879	help
1880	  Memory Protection Keys provides a mechanism for enforcing
1881	  page-based protections, but without requiring modification of the
1882	  page tables when an application changes protection domains.
1883
1884	  For details, see Documentation/core-api/protection-keys.rst
1885
1886	  If unsure, say y.
1887
1888choice
1889	prompt "TSX enable mode"
1890	depends on CPU_SUP_INTEL
1891	default X86_INTEL_TSX_MODE_OFF
1892	help
1893	  Intel's TSX (Transactional Synchronization Extensions) feature
1894	  allows to optimize locking protocols through lock elision which
1895	  can lead to a noticeable performance boost.
1896
1897	  On the other hand it has been shown that TSX can be exploited
1898	  to form side channel attacks (e.g. TAA) and chances are there
1899	  will be more of those attacks discovered in the future.
1900
1901	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1902	  might override this decision by tsx=on the command line parameter.
1903	  Even with TSX enabled, the kernel will attempt to enable the best
1904	  possible TAA mitigation setting depending on the microcode available
1905	  for the particular machine.
1906
1907	  This option allows to set the default tsx mode between tsx=on, =off
1908	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1909	  details.
1910
1911	  Say off if not sure, auto if TSX is in use but it should be used on safe
1912	  platforms or on if TSX is in use and the security aspect of tsx is not
1913	  relevant.
1914
1915config X86_INTEL_TSX_MODE_OFF
1916	bool "off"
1917	help
1918	  TSX is disabled if possible - equals to tsx=off command line parameter.
1919
1920config X86_INTEL_TSX_MODE_ON
1921	bool "on"
1922	help
1923	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1924	  line parameter.
1925
1926config X86_INTEL_TSX_MODE_AUTO
1927	bool "auto"
1928	help
1929	  TSX is enabled on TSX capable HW that is believed to be safe against
1930	  side channel attacks- equals the tsx=auto command line parameter.
1931endchoice
1932
1933config X86_SGX
1934	bool "Software Guard eXtensions (SGX)"
1935	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1936	depends on CRYPTO=y
1937	depends on CRYPTO_SHA256=y
1938	select MMU_NOTIFIER
1939	select NUMA_KEEP_MEMINFO if NUMA
1940	select XARRAY_MULTI
1941	help
1942	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1943	  that can be used by applications to set aside private regions of code
1944	  and data, referred to as enclaves. An enclave's private memory can
1945	  only be accessed by code running within the enclave. Accesses from
1946	  outside the enclave, including other enclaves, are disallowed by
1947	  hardware.
1948
1949	  If unsure, say N.
1950
1951config EFI
1952	bool "EFI runtime service support"
1953	depends on ACPI
1954	select UCS2_STRING
1955	select EFI_RUNTIME_WRAPPERS
1956	select ARCH_USE_MEMREMAP_PROT
1957	help
1958	  This enables the kernel to use EFI runtime services that are
1959	  available (such as the EFI variable services).
1960
1961	  This option is only useful on systems that have EFI firmware.
1962	  In addition, you should use the latest ELILO loader available
1963	  at <http://elilo.sourceforge.net> in order to take advantage
1964	  of EFI runtime services. However, even with this option, the
1965	  resultant kernel should continue to boot on existing non-EFI
1966	  platforms.
1967
1968config EFI_STUB
1969	bool "EFI stub support"
1970	depends on EFI
1971	select RELOCATABLE
1972	help
1973	  This kernel feature allows a bzImage to be loaded directly
1974	  by EFI firmware without the use of a bootloader.
1975
1976	  See Documentation/admin-guide/efi-stub.rst for more information.
1977
1978config EFI_HANDOVER_PROTOCOL
1979	bool "EFI handover protocol (DEPRECATED)"
1980	depends on EFI_STUB
1981	default y
1982	help
1983	  Select this in order to include support for the deprecated EFI
1984	  handover protocol, which defines alternative entry points into the
1985	  EFI stub.  This is a practice that has no basis in the UEFI
1986	  specification, and requires a priori knowledge on the part of the
1987	  bootloader about Linux/x86 specific ways of passing the command line
1988	  and initrd, and where in memory those assets may be loaded.
1989
1990	  If in doubt, say Y. Even though the corresponding support is not
1991	  present in upstream GRUB or other bootloaders, most distros build
1992	  GRUB with numerous downstream patches applied, and may rely on the
1993	  handover protocol as as result.
1994
1995config EFI_MIXED
1996	bool "EFI mixed-mode support"
1997	depends on EFI_STUB && X86_64
1998	help
1999	  Enabling this feature allows a 64-bit kernel to be booted
2000	  on a 32-bit firmware, provided that your CPU supports 64-bit
2001	  mode.
2002
2003	  Note that it is not possible to boot a mixed-mode enabled
2004	  kernel via the EFI boot stub - a bootloader that supports
2005	  the EFI handover protocol must be used.
2006
2007	  If unsure, say N.
2008
2009config EFI_FAKE_MEMMAP
2010	bool "Enable EFI fake memory map"
2011	depends on EFI
2012	help
2013	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2014	  this parameter, you can add arbitrary attribute to specific memory
2015	  range by updating original (firmware provided) EFI memmap.  This is
2016	  useful for debugging of EFI memmap related feature, e.g., Address
2017	  Range Mirroring feature.
2018
2019config EFI_MAX_FAKE_MEM
2020	int "maximum allowable number of ranges in efi_fake_mem boot option"
2021	depends on EFI_FAKE_MEMMAP
2022	range 1 128
2023	default 8
2024	help
2025	  Maximum allowable number of ranges in efi_fake_mem boot option.
2026	  Ranges can be set up to this value using comma-separated list.
2027	  The default value is 8.
2028
2029config EFI_RUNTIME_MAP
2030	bool "Export EFI runtime maps to sysfs" if EXPERT
2031	depends on EFI
2032	default KEXEC_CORE
2033	help
2034	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2035	  That memory map is required by the 2nd kernel to set up EFI virtual
2036	  mappings after kexec, but can also be used for debugging purposes.
2037
2038	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2039
2040source "kernel/Kconfig.hz"
2041
2042config KEXEC
2043	bool "kexec system call"
2044	select KEXEC_CORE
2045	help
2046	  kexec is a system call that implements the ability to shutdown your
2047	  current kernel, and to start another kernel.  It is like a reboot
2048	  but it is independent of the system firmware.   And like a reboot
2049	  you can start any kernel with it, not just Linux.
2050
2051	  The name comes from the similarity to the exec system call.
2052
2053	  It is an ongoing process to be certain the hardware in a machine
2054	  is properly shutdown, so do not be surprised if this code does not
2055	  initially work for you.  As of this writing the exact hardware
2056	  interface is strongly in flux, so no good recommendation can be
2057	  made.
2058
2059config KEXEC_FILE
2060	bool "kexec file based system call"
2061	select KEXEC_CORE
2062	select HAVE_IMA_KEXEC if IMA
2063	depends on X86_64
2064	depends on CRYPTO=y
2065	depends on CRYPTO_SHA256=y
2066	help
2067	  This is new version of kexec system call. This system call is
2068	  file based and takes file descriptors as system call argument
2069	  for kernel and initramfs as opposed to list of segments as
2070	  accepted by previous system call.
2071
2072config ARCH_HAS_KEXEC_PURGATORY
2073	def_bool KEXEC_FILE
2074
2075config KEXEC_SIG
2076	bool "Verify kernel signature during kexec_file_load() syscall"
2077	depends on KEXEC_FILE
2078	help
2079
2080	  This option makes the kexec_file_load() syscall check for a valid
2081	  signature of the kernel image.  The image can still be loaded without
2082	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2083	  there's a signature that we can check, then it must be valid.
2084
2085	  In addition to this option, you need to enable signature
2086	  verification for the corresponding kernel image type being
2087	  loaded in order for this to work.
2088
2089config KEXEC_SIG_FORCE
2090	bool "Require a valid signature in kexec_file_load() syscall"
2091	depends on KEXEC_SIG
2092	help
2093	  This option makes kernel signature verification mandatory for
2094	  the kexec_file_load() syscall.
2095
2096config KEXEC_BZIMAGE_VERIFY_SIG
2097	bool "Enable bzImage signature verification support"
2098	depends on KEXEC_SIG
2099	depends on SIGNED_PE_FILE_VERIFICATION
2100	select SYSTEM_TRUSTED_KEYRING
2101	help
2102	  Enable bzImage signature verification support.
2103
2104config CRASH_DUMP
2105	bool "kernel crash dumps"
2106	depends on X86_64 || (X86_32 && HIGHMEM)
2107	help
2108	  Generate crash dump after being started by kexec.
2109	  This should be normally only set in special crash dump kernels
2110	  which are loaded in the main kernel with kexec-tools into
2111	  a specially reserved region and then later executed after
2112	  a crash by kdump/kexec. The crash dump kernel must be compiled
2113	  to a memory address not used by the main kernel or BIOS using
2114	  PHYSICAL_START, or it must be built as a relocatable image
2115	  (CONFIG_RELOCATABLE=y).
2116	  For more details see Documentation/admin-guide/kdump/kdump.rst
2117
2118config KEXEC_JUMP
2119	bool "kexec jump"
2120	depends on KEXEC && HIBERNATION
2121	help
2122	  Jump between original kernel and kexeced kernel and invoke
2123	  code in physical address mode via KEXEC
2124
2125config PHYSICAL_START
2126	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2127	default "0x1000000"
2128	help
2129	  This gives the physical address where the kernel is loaded.
2130
2131	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2132	  bzImage will decompress itself to above physical address and
2133	  run from there. Otherwise, bzImage will run from the address where
2134	  it has been loaded by the boot loader and will ignore above physical
2135	  address.
2136
2137	  In normal kdump cases one does not have to set/change this option
2138	  as now bzImage can be compiled as a completely relocatable image
2139	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2140	  address. This option is mainly useful for the folks who don't want
2141	  to use a bzImage for capturing the crash dump and want to use a
2142	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2143	  to be specifically compiled to run from a specific memory area
2144	  (normally a reserved region) and this option comes handy.
2145
2146	  So if you are using bzImage for capturing the crash dump,
2147	  leave the value here unchanged to 0x1000000 and set
2148	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2149	  for capturing the crash dump change this value to start of
2150	  the reserved region.  In other words, it can be set based on
2151	  the "X" value as specified in the "crashkernel=YM@XM"
2152	  command line boot parameter passed to the panic-ed
2153	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2154	  for more details about crash dumps.
2155
2156	  Usage of bzImage for capturing the crash dump is recommended as
2157	  one does not have to build two kernels. Same kernel can be used
2158	  as production kernel and capture kernel. Above option should have
2159	  gone away after relocatable bzImage support is introduced. But it
2160	  is present because there are users out there who continue to use
2161	  vmlinux for dump capture. This option should go away down the
2162	  line.
2163
2164	  Don't change this unless you know what you are doing.
2165
2166config RELOCATABLE
2167	bool "Build a relocatable kernel"
2168	default y
2169	help
2170	  This builds a kernel image that retains relocation information
2171	  so it can be loaded someplace besides the default 1MB.
2172	  The relocations tend to make the kernel binary about 10% larger,
2173	  but are discarded at runtime.
2174
2175	  One use is for the kexec on panic case where the recovery kernel
2176	  must live at a different physical address than the primary
2177	  kernel.
2178
2179	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2180	  it has been loaded at and the compile time physical address
2181	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2182
2183config RANDOMIZE_BASE
2184	bool "Randomize the address of the kernel image (KASLR)"
2185	depends on RELOCATABLE
2186	default y
2187	help
2188	  In support of Kernel Address Space Layout Randomization (KASLR),
2189	  this randomizes the physical address at which the kernel image
2190	  is decompressed and the virtual address where the kernel
2191	  image is mapped, as a security feature that deters exploit
2192	  attempts relying on knowledge of the location of kernel
2193	  code internals.
2194
2195	  On 64-bit, the kernel physical and virtual addresses are
2196	  randomized separately. The physical address will be anywhere
2197	  between 16MB and the top of physical memory (up to 64TB). The
2198	  virtual address will be randomized from 16MB up to 1GB (9 bits
2199	  of entropy). Note that this also reduces the memory space
2200	  available to kernel modules from 1.5GB to 1GB.
2201
2202	  On 32-bit, the kernel physical and virtual addresses are
2203	  randomized together. They will be randomized from 16MB up to
2204	  512MB (8 bits of entropy).
2205
2206	  Entropy is generated using the RDRAND instruction if it is
2207	  supported. If RDTSC is supported, its value is mixed into
2208	  the entropy pool as well. If neither RDRAND nor RDTSC are
2209	  supported, then entropy is read from the i8254 timer. The
2210	  usable entropy is limited by the kernel being built using
2211	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2212	  minimum of 2MB. As a result, only 10 bits of entropy are
2213	  theoretically possible, but the implementations are further
2214	  limited due to memory layouts.
2215
2216	  If unsure, say Y.
2217
2218# Relocation on x86 needs some additional build support
2219config X86_NEED_RELOCS
2220	def_bool y
2221	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2222
2223config PHYSICAL_ALIGN
2224	hex "Alignment value to which kernel should be aligned"
2225	default "0x200000"
2226	range 0x2000 0x1000000 if X86_32
2227	range 0x200000 0x1000000 if X86_64
2228	help
2229	  This value puts the alignment restrictions on physical address
2230	  where kernel is loaded and run from. Kernel is compiled for an
2231	  address which meets above alignment restriction.
2232
2233	  If bootloader loads the kernel at a non-aligned address and
2234	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2235	  address aligned to above value and run from there.
2236
2237	  If bootloader loads the kernel at a non-aligned address and
2238	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2239	  load address and decompress itself to the address it has been
2240	  compiled for and run from there. The address for which kernel is
2241	  compiled already meets above alignment restrictions. Hence the
2242	  end result is that kernel runs from a physical address meeting
2243	  above alignment restrictions.
2244
2245	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2246	  this value must be a multiple of 0x200000.
2247
2248	  Don't change this unless you know what you are doing.
2249
2250config DYNAMIC_MEMORY_LAYOUT
2251	bool
2252	help
2253	  This option makes base addresses of vmalloc and vmemmap as well as
2254	  __PAGE_OFFSET movable during boot.
2255
2256config RANDOMIZE_MEMORY
2257	bool "Randomize the kernel memory sections"
2258	depends on X86_64
2259	depends on RANDOMIZE_BASE
2260	select DYNAMIC_MEMORY_LAYOUT
2261	default RANDOMIZE_BASE
2262	help
2263	  Randomizes the base virtual address of kernel memory sections
2264	  (physical memory mapping, vmalloc & vmemmap). This security feature
2265	  makes exploits relying on predictable memory locations less reliable.
2266
2267	  The order of allocations remains unchanged. Entropy is generated in
2268	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2269	  configuration have in average 30,000 different possible virtual
2270	  addresses for each memory section.
2271
2272	  If unsure, say Y.
2273
2274config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2275	hex "Physical memory mapping padding" if EXPERT
2276	depends on RANDOMIZE_MEMORY
2277	default "0xa" if MEMORY_HOTPLUG
2278	default "0x0"
2279	range 0x1 0x40 if MEMORY_HOTPLUG
2280	range 0x0 0x40
2281	help
2282	  Define the padding in terabytes added to the existing physical
2283	  memory size during kernel memory randomization. It is useful
2284	  for memory hotplug support but reduces the entropy available for
2285	  address randomization.
2286
2287	  If unsure, leave at the default value.
2288
2289config ADDRESS_MASKING
2290	bool "Linear Address Masking support"
2291	depends on X86_64
2292	help
2293	  Linear Address Masking (LAM) modifies the checking that is applied
2294	  to 64-bit linear addresses, allowing software to use of the
2295	  untranslated address bits for metadata.
2296
2297	  The capability can be used for efficient address sanitizers (ASAN)
2298	  implementation and for optimizations in JITs.
2299
2300config HOTPLUG_CPU
2301	def_bool y
2302	depends on SMP
2303
2304config COMPAT_VDSO
2305	def_bool n
2306	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2307	depends on COMPAT_32
2308	help
2309	  Certain buggy versions of glibc will crash if they are
2310	  presented with a 32-bit vDSO that is not mapped at the address
2311	  indicated in its segment table.
2312
2313	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2314	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2315	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2316	  the only released version with the bug, but OpenSUSE 9
2317	  contains a buggy "glibc 2.3.2".
2318
2319	  The symptom of the bug is that everything crashes on startup, saying:
2320	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2321
2322	  Saying Y here changes the default value of the vdso32 boot
2323	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2324	  This works around the glibc bug but hurts performance.
2325
2326	  If unsure, say N: if you are compiling your own kernel, you
2327	  are unlikely to be using a buggy version of glibc.
2328
2329choice
2330	prompt "vsyscall table for legacy applications"
2331	depends on X86_64
2332	default LEGACY_VSYSCALL_XONLY
2333	help
2334	  Legacy user code that does not know how to find the vDSO expects
2335	  to be able to issue three syscalls by calling fixed addresses in
2336	  kernel space. Since this location is not randomized with ASLR,
2337	  it can be used to assist security vulnerability exploitation.
2338
2339	  This setting can be changed at boot time via the kernel command
2340	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2341	  is deprecated and can only be enabled using the kernel command
2342	  line.
2343
2344	  On a system with recent enough glibc (2.14 or newer) and no
2345	  static binaries, you can say None without a performance penalty
2346	  to improve security.
2347
2348	  If unsure, select "Emulate execution only".
2349
2350	config LEGACY_VSYSCALL_XONLY
2351		bool "Emulate execution only"
2352		help
2353		  The kernel traps and emulates calls into the fixed vsyscall
2354		  address mapping and does not allow reads.  This
2355		  configuration is recommended when userspace might use the
2356		  legacy vsyscall area but support for legacy binary
2357		  instrumentation of legacy code is not needed.  It mitigates
2358		  certain uses of the vsyscall area as an ASLR-bypassing
2359		  buffer.
2360
2361	config LEGACY_VSYSCALL_NONE
2362		bool "None"
2363		help
2364		  There will be no vsyscall mapping at all. This will
2365		  eliminate any risk of ASLR bypass due to the vsyscall
2366		  fixed address mapping. Attempts to use the vsyscalls
2367		  will be reported to dmesg, so that either old or
2368		  malicious userspace programs can be identified.
2369
2370endchoice
2371
2372config CMDLINE_BOOL
2373	bool "Built-in kernel command line"
2374	help
2375	  Allow for specifying boot arguments to the kernel at
2376	  build time.  On some systems (e.g. embedded ones), it is
2377	  necessary or convenient to provide some or all of the
2378	  kernel boot arguments with the kernel itself (that is,
2379	  to not rely on the boot loader to provide them.)
2380
2381	  To compile command line arguments into the kernel,
2382	  set this option to 'Y', then fill in the
2383	  boot arguments in CONFIG_CMDLINE.
2384
2385	  Systems with fully functional boot loaders (i.e. non-embedded)
2386	  should leave this option set to 'N'.
2387
2388config CMDLINE
2389	string "Built-in kernel command string"
2390	depends on CMDLINE_BOOL
2391	default ""
2392	help
2393	  Enter arguments here that should be compiled into the kernel
2394	  image and used at boot time.  If the boot loader provides a
2395	  command line at boot time, it is appended to this string to
2396	  form the full kernel command line, when the system boots.
2397
2398	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2399	  change this behavior.
2400
2401	  In most cases, the command line (whether built-in or provided
2402	  by the boot loader) should specify the device for the root
2403	  file system.
2404
2405config CMDLINE_OVERRIDE
2406	bool "Built-in command line overrides boot loader arguments"
2407	depends on CMDLINE_BOOL && CMDLINE != ""
2408	help
2409	  Set this option to 'Y' to have the kernel ignore the boot loader
2410	  command line, and use ONLY the built-in command line.
2411
2412	  This is used to work around broken boot loaders.  This should
2413	  be set to 'N' under normal conditions.
2414
2415config MODIFY_LDT_SYSCALL
2416	bool "Enable the LDT (local descriptor table)" if EXPERT
2417	default y
2418	help
2419	  Linux can allow user programs to install a per-process x86
2420	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2421	  call.  This is required to run 16-bit or segmented code such as
2422	  DOSEMU or some Wine programs.  It is also used by some very old
2423	  threading libraries.
2424
2425	  Enabling this feature adds a small amount of overhead to
2426	  context switches and increases the low-level kernel attack
2427	  surface.  Disabling it removes the modify_ldt(2) system call.
2428
2429	  Saying 'N' here may make sense for embedded or server kernels.
2430
2431config STRICT_SIGALTSTACK_SIZE
2432	bool "Enforce strict size checking for sigaltstack"
2433	depends on DYNAMIC_SIGFRAME
2434	help
2435	  For historical reasons MINSIGSTKSZ is a constant which became
2436	  already too small with AVX512 support. Add a mechanism to
2437	  enforce strict checking of the sigaltstack size against the
2438	  real size of the FPU frame. This option enables the check
2439	  by default. It can also be controlled via the kernel command
2440	  line option 'strict_sas_size' independent of this config
2441	  switch. Enabling it might break existing applications which
2442	  allocate a too small sigaltstack but 'work' because they
2443	  never get a signal delivered.
2444
2445	  Say 'N' unless you want to really enforce this check.
2446
2447source "kernel/livepatch/Kconfig"
2448
2449endmenu
2450
2451config CC_HAS_SLS
2452	def_bool $(cc-option,-mharden-sls=all)
2453
2454config CC_HAS_RETURN_THUNK
2455	def_bool $(cc-option,-mfunction-return=thunk-extern)
2456
2457config CC_HAS_ENTRY_PADDING
2458	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2459
2460config FUNCTION_PADDING_CFI
2461	int
2462	default 59 if FUNCTION_ALIGNMENT_64B
2463	default 27 if FUNCTION_ALIGNMENT_32B
2464	default 11 if FUNCTION_ALIGNMENT_16B
2465	default  3 if FUNCTION_ALIGNMENT_8B
2466	default  0
2467
2468# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2469# except Kconfig can't do arithmetic :/
2470config FUNCTION_PADDING_BYTES
2471	int
2472	default FUNCTION_PADDING_CFI if CFI_CLANG
2473	default FUNCTION_ALIGNMENT
2474
2475config CALL_PADDING
2476	def_bool n
2477	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2478	select FUNCTION_ALIGNMENT_16B
2479
2480config FINEIBT
2481	def_bool y
2482	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2483	select CALL_PADDING
2484
2485config HAVE_CALL_THUNKS
2486	def_bool y
2487	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2488
2489config CALL_THUNKS
2490	def_bool n
2491	select CALL_PADDING
2492
2493config PREFIX_SYMBOLS
2494	def_bool y
2495	depends on CALL_PADDING && !CFI_CLANG
2496
2497menuconfig SPECULATION_MITIGATIONS
2498	bool "Mitigations for speculative execution vulnerabilities"
2499	default y
2500	help
2501	  Say Y here to enable options which enable mitigations for
2502	  speculative execution hardware vulnerabilities.
2503
2504	  If you say N, all mitigations will be disabled. You really
2505	  should know what you are doing to say so.
2506
2507if SPECULATION_MITIGATIONS
2508
2509config PAGE_TABLE_ISOLATION
2510	bool "Remove the kernel mapping in user mode"
2511	default y
2512	depends on (X86_64 || X86_PAE)
2513	help
2514	  This feature reduces the number of hardware side channels by
2515	  ensuring that the majority of kernel addresses are not mapped
2516	  into userspace.
2517
2518	  See Documentation/arch/x86/pti.rst for more details.
2519
2520config RETPOLINE
2521	bool "Avoid speculative indirect branches in kernel"
2522	select OBJTOOL if HAVE_OBJTOOL
2523	default y
2524	help
2525	  Compile kernel with the retpoline compiler options to guard against
2526	  kernel-to-user data leaks by avoiding speculative indirect
2527	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2528	  support for full protection. The kernel may run slower.
2529
2530config RETHUNK
2531	bool "Enable return-thunks"
2532	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2533	select OBJTOOL if HAVE_OBJTOOL
2534	default y if X86_64
2535	help
2536	  Compile the kernel with the return-thunks compiler option to guard
2537	  against kernel-to-user data leaks by avoiding return speculation.
2538	  Requires a compiler with -mfunction-return=thunk-extern
2539	  support for full protection. The kernel may run slower.
2540
2541config CPU_UNRET_ENTRY
2542	bool "Enable UNRET on kernel entry"
2543	depends on CPU_SUP_AMD && RETHUNK && X86_64
2544	default y
2545	help
2546	  Compile the kernel with support for the retbleed=unret mitigation.
2547
2548config CALL_DEPTH_TRACKING
2549	bool "Mitigate RSB underflow with call depth tracking"
2550	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2551	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2552	select CALL_THUNKS
2553	default y
2554	help
2555	  Compile the kernel with call depth tracking to mitigate the Intel
2556	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2557	  mitigation is off by default and needs to be enabled on the
2558	  kernel command line via the retbleed=stuff option. For
2559	  non-affected systems the overhead of this option is marginal as
2560	  the call depth tracking is using run-time generated call thunks
2561	  in a compiler generated padding area and call patching. This
2562	  increases text size by ~5%. For non affected systems this space
2563	  is unused. On affected SKL systems this results in a significant
2564	  performance gain over the IBRS mitigation.
2565
2566config CALL_THUNKS_DEBUG
2567	bool "Enable call thunks and call depth tracking debugging"
2568	depends on CALL_DEPTH_TRACKING
2569	select FUNCTION_ALIGNMENT_32B
2570	default n
2571	help
2572	  Enable call/ret counters for imbalance detection and build in
2573	  a noisy dmesg about callthunks generation and call patching for
2574	  trouble shooting. The debug prints need to be enabled on the
2575	  kernel command line with 'debug-callthunks'.
2576	  Only enable this when you are debugging call thunks as this
2577	  creates a noticeable runtime overhead. If unsure say N.
2578
2579config CPU_IBPB_ENTRY
2580	bool "Enable IBPB on kernel entry"
2581	depends on CPU_SUP_AMD && X86_64
2582	default y
2583	help
2584	  Compile the kernel with support for the retbleed=ibpb mitigation.
2585
2586config CPU_IBRS_ENTRY
2587	bool "Enable IBRS on kernel entry"
2588	depends on CPU_SUP_INTEL && X86_64
2589	default y
2590	help
2591	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2592	  This mitigates both spectre_v2 and retbleed at great cost to
2593	  performance.
2594
2595config SLS
2596	bool "Mitigate Straight-Line-Speculation"
2597	depends on CC_HAS_SLS && X86_64
2598	select OBJTOOL if HAVE_OBJTOOL
2599	default n
2600	help
2601	  Compile the kernel with straight-line-speculation options to guard
2602	  against straight line speculation. The kernel image might be slightly
2603	  larger.
2604
2605endif
2606
2607config ARCH_HAS_ADD_PAGES
2608	def_bool y
2609	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2610
2611config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2612	def_bool y
2613
2614menu "Power management and ACPI options"
2615
2616config ARCH_HIBERNATION_HEADER
2617	def_bool y
2618	depends on HIBERNATION
2619
2620source "kernel/power/Kconfig"
2621
2622source "drivers/acpi/Kconfig"
2623
2624config X86_APM_BOOT
2625	def_bool y
2626	depends on APM
2627
2628menuconfig APM
2629	tristate "APM (Advanced Power Management) BIOS support"
2630	depends on X86_32 && PM_SLEEP
2631	help
2632	  APM is a BIOS specification for saving power using several different
2633	  techniques. This is mostly useful for battery powered laptops with
2634	  APM compliant BIOSes. If you say Y here, the system time will be
2635	  reset after a RESUME operation, the /proc/apm device will provide
2636	  battery status information, and user-space programs will receive
2637	  notification of APM "events" (e.g. battery status change).
2638
2639	  If you select "Y" here, you can disable actual use of the APM
2640	  BIOS by passing the "apm=off" option to the kernel at boot time.
2641
2642	  Note that the APM support is almost completely disabled for
2643	  machines with more than one CPU.
2644
2645	  In order to use APM, you will need supporting software. For location
2646	  and more information, read <file:Documentation/power/apm-acpi.rst>
2647	  and the Battery Powered Linux mini-HOWTO, available from
2648	  <http://www.tldp.org/docs.html#howto>.
2649
2650	  This driver does not spin down disk drives (see the hdparm(8)
2651	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2652	  VESA-compliant "green" monitors.
2653
2654	  This driver does not support the TI 4000M TravelMate and the ACER
2655	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2656	  desktop machines also don't have compliant BIOSes, and this driver
2657	  may cause those machines to panic during the boot phase.
2658
2659	  Generally, if you don't have a battery in your machine, there isn't
2660	  much point in using this driver and you should say N. If you get
2661	  random kernel OOPSes or reboots that don't seem to be related to
2662	  anything, try disabling/enabling this option (or disabling/enabling
2663	  APM in your BIOS).
2664
2665	  Some other things you should try when experiencing seemingly random,
2666	  "weird" problems:
2667
2668	  1) make sure that you have enough swap space and that it is
2669	  enabled.
2670	  2) pass the "idle=poll" option to the kernel
2671	  3) switch on floating point emulation in the kernel and pass
2672	  the "no387" option to the kernel
2673	  4) pass the "floppy=nodma" option to the kernel
2674	  5) pass the "mem=4M" option to the kernel (thereby disabling
2675	  all but the first 4 MB of RAM)
2676	  6) make sure that the CPU is not over clocked.
2677	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2678	  8) disable the cache from your BIOS settings
2679	  9) install a fan for the video card or exchange video RAM
2680	  10) install a better fan for the CPU
2681	  11) exchange RAM chips
2682	  12) exchange the motherboard.
2683
2684	  To compile this driver as a module, choose M here: the
2685	  module will be called apm.
2686
2687if APM
2688
2689config APM_IGNORE_USER_SUSPEND
2690	bool "Ignore USER SUSPEND"
2691	help
2692	  This option will ignore USER SUSPEND requests. On machines with a
2693	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2694	  series notebooks, it is necessary to say Y because of a BIOS bug.
2695
2696config APM_DO_ENABLE
2697	bool "Enable PM at boot time"
2698	help
2699	  Enable APM features at boot time. From page 36 of the APM BIOS
2700	  specification: "When disabled, the APM BIOS does not automatically
2701	  power manage devices, enter the Standby State, enter the Suspend
2702	  State, or take power saving steps in response to CPU Idle calls."
2703	  This driver will make CPU Idle calls when Linux is idle (unless this
2704	  feature is turned off -- see "Do CPU IDLE calls", below). This
2705	  should always save battery power, but more complicated APM features
2706	  will be dependent on your BIOS implementation. You may need to turn
2707	  this option off if your computer hangs at boot time when using APM
2708	  support, or if it beeps continuously instead of suspending. Turn
2709	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2710	  T400CDT. This is off by default since most machines do fine without
2711	  this feature.
2712
2713config APM_CPU_IDLE
2714	depends on CPU_IDLE
2715	bool "Make CPU Idle calls when idle"
2716	help
2717	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2718	  On some machines, this can activate improved power savings, such as
2719	  a slowed CPU clock rate, when the machine is idle. These idle calls
2720	  are made after the idle loop has run for some length of time (e.g.,
2721	  333 mS). On some machines, this will cause a hang at boot time or
2722	  whenever the CPU becomes idle. (On machines with more than one CPU,
2723	  this option does nothing.)
2724
2725config APM_DISPLAY_BLANK
2726	bool "Enable console blanking using APM"
2727	help
2728	  Enable console blanking using the APM. Some laptops can use this to
2729	  turn off the LCD backlight when the screen blanker of the Linux
2730	  virtual console blanks the screen. Note that this is only used by
2731	  the virtual console screen blanker, and won't turn off the backlight
2732	  when using the X Window system. This also doesn't have anything to
2733	  do with your VESA-compliant power-saving monitor. Further, this
2734	  option doesn't work for all laptops -- it might not turn off your
2735	  backlight at all, or it might print a lot of errors to the console,
2736	  especially if you are using gpm.
2737
2738config APM_ALLOW_INTS
2739	bool "Allow interrupts during APM BIOS calls"
2740	help
2741	  Normally we disable external interrupts while we are making calls to
2742	  the APM BIOS as a measure to lessen the effects of a badly behaving
2743	  BIOS implementation.  The BIOS should reenable interrupts if it
2744	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2745	  many of the newer IBM Thinkpads.  If you experience hangs when you
2746	  suspend, try setting this to Y.  Otherwise, say N.
2747
2748endif # APM
2749
2750source "drivers/cpufreq/Kconfig"
2751
2752source "drivers/cpuidle/Kconfig"
2753
2754source "drivers/idle/Kconfig"
2755
2756endmenu
2757
2758menu "Bus options (PCI etc.)"
2759
2760choice
2761	prompt "PCI access mode"
2762	depends on X86_32 && PCI
2763	default PCI_GOANY
2764	help
2765	  On PCI systems, the BIOS can be used to detect the PCI devices and
2766	  determine their configuration. However, some old PCI motherboards
2767	  have BIOS bugs and may crash if this is done. Also, some embedded
2768	  PCI-based systems don't have any BIOS at all. Linux can also try to
2769	  detect the PCI hardware directly without using the BIOS.
2770
2771	  With this option, you can specify how Linux should detect the
2772	  PCI devices. If you choose "BIOS", the BIOS will be used,
2773	  if you choose "Direct", the BIOS won't be used, and if you
2774	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2775	  If you choose "Any", the kernel will try MMCONFIG, then the
2776	  direct access method and falls back to the BIOS if that doesn't
2777	  work. If unsure, go with the default, which is "Any".
2778
2779config PCI_GOBIOS
2780	bool "BIOS"
2781
2782config PCI_GOMMCONFIG
2783	bool "MMConfig"
2784
2785config PCI_GODIRECT
2786	bool "Direct"
2787
2788config PCI_GOOLPC
2789	bool "OLPC XO-1"
2790	depends on OLPC
2791
2792config PCI_GOANY
2793	bool "Any"
2794
2795endchoice
2796
2797config PCI_BIOS
2798	def_bool y
2799	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2800
2801# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2802config PCI_DIRECT
2803	def_bool y
2804	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2805
2806config PCI_MMCONFIG
2807	bool "Support mmconfig PCI config space access" if X86_64
2808	default y
2809	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2810	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2811
2812config PCI_OLPC
2813	def_bool y
2814	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2815
2816config PCI_XEN
2817	def_bool y
2818	depends on PCI && XEN
2819
2820config MMCONF_FAM10H
2821	def_bool y
2822	depends on X86_64 && PCI_MMCONFIG && ACPI
2823
2824config PCI_CNB20LE_QUIRK
2825	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2826	depends on PCI
2827	help
2828	  Read the PCI windows out of the CNB20LE host bridge. This allows
2829	  PCI hotplug to work on systems with the CNB20LE chipset which do
2830	  not have ACPI.
2831
2832	  There's no public spec for this chipset, and this functionality
2833	  is known to be incomplete.
2834
2835	  You should say N unless you know you need this.
2836
2837config ISA_BUS
2838	bool "ISA bus support on modern systems" if EXPERT
2839	help
2840	  Expose ISA bus device drivers and options available for selection and
2841	  configuration. Enable this option if your target machine has an ISA
2842	  bus. ISA is an older system, displaced by PCI and newer bus
2843	  architectures -- if your target machine is modern, it probably does
2844	  not have an ISA bus.
2845
2846	  If unsure, say N.
2847
2848# x86_64 have no ISA slots, but can have ISA-style DMA.
2849config ISA_DMA_API
2850	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2851	default y
2852	help
2853	  Enables ISA-style DMA support for devices requiring such controllers.
2854	  If unsure, say Y.
2855
2856if X86_32
2857
2858config ISA
2859	bool "ISA support"
2860	help
2861	  Find out whether you have ISA slots on your motherboard.  ISA is the
2862	  name of a bus system, i.e. the way the CPU talks to the other stuff
2863	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2864	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2865	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2866
2867config SCx200
2868	tristate "NatSemi SCx200 support"
2869	help
2870	  This provides basic support for National Semiconductor's
2871	  (now AMD's) Geode processors.  The driver probes for the
2872	  PCI-IDs of several on-chip devices, so its a good dependency
2873	  for other scx200_* drivers.
2874
2875	  If compiled as a module, the driver is named scx200.
2876
2877config SCx200HR_TIMER
2878	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2879	depends on SCx200
2880	default y
2881	help
2882	  This driver provides a clocksource built upon the on-chip
2883	  27MHz high-resolution timer.  Its also a workaround for
2884	  NSC Geode SC-1100's buggy TSC, which loses time when the
2885	  processor goes idle (as is done by the scheduler).  The
2886	  other workaround is idle=poll boot option.
2887
2888config OLPC
2889	bool "One Laptop Per Child support"
2890	depends on !X86_PAE
2891	select GPIOLIB
2892	select OF
2893	select OF_PROMTREE
2894	select IRQ_DOMAIN
2895	select OLPC_EC
2896	help
2897	  Add support for detecting the unique features of the OLPC
2898	  XO hardware.
2899
2900config OLPC_XO1_PM
2901	bool "OLPC XO-1 Power Management"
2902	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2903	help
2904	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2905
2906config OLPC_XO1_RTC
2907	bool "OLPC XO-1 Real Time Clock"
2908	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2909	help
2910	  Add support for the XO-1 real time clock, which can be used as a
2911	  programmable wakeup source.
2912
2913config OLPC_XO1_SCI
2914	bool "OLPC XO-1 SCI extras"
2915	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2916	depends on INPUT=y
2917	select POWER_SUPPLY
2918	help
2919	  Add support for SCI-based features of the OLPC XO-1 laptop:
2920	   - EC-driven system wakeups
2921	   - Power button
2922	   - Ebook switch
2923	   - Lid switch
2924	   - AC adapter status updates
2925	   - Battery status updates
2926
2927config OLPC_XO15_SCI
2928	bool "OLPC XO-1.5 SCI extras"
2929	depends on OLPC && ACPI
2930	select POWER_SUPPLY
2931	help
2932	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2933	   - EC-driven system wakeups
2934	   - AC adapter status updates
2935	   - Battery status updates
2936
2937config ALIX
2938	bool "PCEngines ALIX System Support (LED setup)"
2939	select GPIOLIB
2940	help
2941	  This option enables system support for the PCEngines ALIX.
2942	  At present this just sets up LEDs for GPIO control on
2943	  ALIX2/3/6 boards.  However, other system specific setup should
2944	  get added here.
2945
2946	  Note: You must still enable the drivers for GPIO and LED support
2947	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2948
2949	  Note: You have to set alix.force=1 for boards with Award BIOS.
2950
2951config NET5501
2952	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2953	select GPIOLIB
2954	help
2955	  This option enables system support for the Soekris Engineering net5501.
2956
2957config GEOS
2958	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2959	select GPIOLIB
2960	depends on DMI
2961	help
2962	  This option enables system support for the Traverse Technologies GEOS.
2963
2964config TS5500
2965	bool "Technologic Systems TS-5500 platform support"
2966	depends on MELAN
2967	select CHECK_SIGNATURE
2968	select NEW_LEDS
2969	select LEDS_CLASS
2970	help
2971	  This option enables system support for the Technologic Systems TS-5500.
2972
2973endif # X86_32
2974
2975config AMD_NB
2976	def_bool y
2977	depends on CPU_SUP_AMD && PCI
2978
2979endmenu
2980
2981menu "Binary Emulations"
2982
2983config IA32_EMULATION
2984	bool "IA32 Emulation"
2985	depends on X86_64
2986	select ARCH_WANT_OLD_COMPAT_IPC
2987	select BINFMT_ELF
2988	select COMPAT_OLD_SIGACTION
2989	help
2990	  Include code to run legacy 32-bit programs under a
2991	  64-bit kernel. You should likely turn this on, unless you're
2992	  100% sure that you don't have any 32-bit programs left.
2993
2994config X86_X32_ABI
2995	bool "x32 ABI for 64-bit mode"
2996	depends on X86_64
2997	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2998	# compressed debug sections to x86_x32 properly:
2999	# https://github.com/ClangBuiltLinux/linux/issues/514
3000	# https://github.com/ClangBuiltLinux/linux/issues/1141
3001	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3002	help
3003	  Include code to run binaries for the x32 native 32-bit ABI
3004	  for 64-bit processors.  An x32 process gets access to the
3005	  full 64-bit register file and wide data path while leaving
3006	  pointers at 32 bits for smaller memory footprint.
3007
3008config COMPAT_32
3009	def_bool y
3010	depends on IA32_EMULATION || X86_32
3011	select HAVE_UID16
3012	select OLD_SIGSUSPEND3
3013
3014config COMPAT
3015	def_bool y
3016	depends on IA32_EMULATION || X86_X32_ABI
3017
3018config COMPAT_FOR_U64_ALIGNMENT
3019	def_bool y
3020	depends on COMPAT
3021
3022endmenu
3023
3024config HAVE_ATOMIC_IOMAP
3025	def_bool y
3026	depends on X86_32
3027
3028source "arch/x86/kvm/Kconfig"
3029
3030source "arch/x86/Kconfig.assembler"
3031