xref: /openbmc/linux/arch/x86/Kconfig (revision bbaf1ff0)
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 NEED_PER_CPU_EMBED_FIRST_CHUNK
283	select NEED_PER_CPU_PAGE_FIRST_CHUNK
284	select NEED_SG_DMA_LENGTH
285	select PCI_DOMAINS			if PCI
286	select PCI_LOCKLESS_CONFIG		if PCI
287	select PERF_EVENTS
288	select RTC_LIB
289	select RTC_MC146818_LIB
290	select SPARSE_IRQ
291	select SYSCTL_EXCEPTION_TRACE
292	select THREAD_INFO_IN_TASK
293	select TRACE_IRQFLAGS_SUPPORT
294	select TRACE_IRQFLAGS_NMI_SUPPORT
295	select USER_STACKTRACE_SUPPORT
296	select HAVE_ARCH_KCSAN			if X86_64
297	select PROC_PID_ARCH_STATUS		if PROC_FS
298	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
299	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
300	select FUNCTION_ALIGNMENT_4B
301	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
302	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
303
304config INSTRUCTION_DECODER
305	def_bool y
306	depends on KPROBES || PERF_EVENTS || UPROBES
307
308config OUTPUT_FORMAT
309	string
310	default "elf32-i386" if X86_32
311	default "elf64-x86-64" if X86_64
312
313config LOCKDEP_SUPPORT
314	def_bool y
315
316config STACKTRACE_SUPPORT
317	def_bool y
318
319config MMU
320	def_bool y
321
322config ARCH_MMAP_RND_BITS_MIN
323	default 28 if 64BIT
324	default 8
325
326config ARCH_MMAP_RND_BITS_MAX
327	default 32 if 64BIT
328	default 16
329
330config ARCH_MMAP_RND_COMPAT_BITS_MIN
331	default 8
332
333config ARCH_MMAP_RND_COMPAT_BITS_MAX
334	default 16
335
336config SBUS
337	bool
338
339config GENERIC_ISA_DMA
340	def_bool y
341	depends on ISA_DMA_API
342
343config GENERIC_CSUM
344	bool
345	default y if KMSAN || KASAN
346
347config GENERIC_BUG
348	def_bool y
349	depends on BUG
350	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
351
352config GENERIC_BUG_RELATIVE_POINTERS
353	bool
354
355config ARCH_MAY_HAVE_PC_FDC
356	def_bool y
357	depends on ISA_DMA_API
358
359config GENERIC_CALIBRATE_DELAY
360	def_bool y
361
362config ARCH_HAS_CPU_RELAX
363	def_bool y
364
365config ARCH_HIBERNATION_POSSIBLE
366	def_bool y
367
368config ARCH_SUSPEND_POSSIBLE
369	def_bool y
370
371config AUDIT_ARCH
372	def_bool y if X86_64
373
374config KASAN_SHADOW_OFFSET
375	hex
376	depends on KASAN
377	default 0xdffffc0000000000
378
379config HAVE_INTEL_TXT
380	def_bool y
381	depends on INTEL_IOMMU && ACPI
382
383config X86_32_SMP
384	def_bool y
385	depends on X86_32 && SMP
386
387config X86_64_SMP
388	def_bool y
389	depends on X86_64 && SMP
390
391config ARCH_SUPPORTS_UPROBES
392	def_bool y
393
394config FIX_EARLYCON_MEM
395	def_bool y
396
397config DYNAMIC_PHYSICAL_MASK
398	bool
399
400config PGTABLE_LEVELS
401	int
402	default 5 if X86_5LEVEL
403	default 4 if X86_64
404	default 3 if X86_PAE
405	default 2
406
407config CC_HAS_SANE_STACKPROTECTOR
408	bool
409	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
410	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
411	help
412	  We have to make sure stack protector is unconditionally disabled if
413	  the compiler produces broken code or if it does not let us control
414	  the segment on 32-bit kernels.
415
416menu "Processor type and features"
417
418config SMP
419	bool "Symmetric multi-processing support"
420	help
421	  This enables support for systems with more than one CPU. If you have
422	  a system with only one CPU, say N. If you have a system with more
423	  than one CPU, say Y.
424
425	  If you say N here, the kernel will run on uni- and multiprocessor
426	  machines, but will use only one CPU of a multiprocessor machine. If
427	  you say Y here, the kernel will run on many, but not all,
428	  uniprocessor machines. On a uniprocessor machine, the kernel
429	  will run faster if you say N here.
430
431	  Note that if you say Y here and choose architecture "586" or
432	  "Pentium" under "Processor family", the kernel will not work on 486
433	  architectures. Similarly, multiprocessor kernels for the "PPro"
434	  architecture may not work on all Pentium based boards.
435
436	  People using multiprocessor machines who say Y here should also say
437	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
438	  Management" code will be disabled if you say Y here.
439
440	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
441	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
442	  <http://www.tldp.org/docs.html#howto>.
443
444	  If you don't know what to do here, say N.
445
446config X86_X2APIC
447	bool "Support x2apic"
448	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
449	help
450	  This enables x2apic support on CPUs that have this feature.
451
452	  This allows 32-bit apic IDs (so it can support very large systems),
453	  and accesses the local apic via MSRs not via mmio.
454
455	  Some Intel systems circa 2022 and later are locked into x2APIC mode
456	  and can not fall back to the legacy APIC modes if SGX or TDX are
457	  enabled in the BIOS. They will boot with very reduced functionality
458	  without enabling this option.
459
460	  If you don't know what to do here, say N.
461
462config X86_MPPARSE
463	bool "Enable MPS table" if ACPI
464	default y
465	depends on X86_LOCAL_APIC
466	help
467	  For old smp systems that do not have proper acpi support. Newer systems
468	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
469
470config GOLDFISH
471	def_bool y
472	depends on X86_GOLDFISH
473
474config X86_CPU_RESCTRL
475	bool "x86 CPU resource control support"
476	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
477	select KERNFS
478	select PROC_CPU_RESCTRL		if PROC_FS
479	help
480	  Enable x86 CPU resource control support.
481
482	  Provide support for the allocation and monitoring of system resources
483	  usage by the CPU.
484
485	  Intel calls this Intel Resource Director Technology
486	  (Intel(R) RDT). More information about RDT can be found in the
487	  Intel x86 Architecture Software Developer Manual.
488
489	  AMD calls this AMD Platform Quality of Service (AMD QoS).
490	  More information about AMD QoS can be found in the AMD64 Technology
491	  Platform Quality of Service Extensions manual.
492
493	  Say N if unsure.
494
495if X86_32
496config X86_BIGSMP
497	bool "Support for big SMP systems with more than 8 CPUs"
498	depends on SMP
499	help
500	  This option is needed for the systems that have more than 8 CPUs.
501
502config X86_EXTENDED_PLATFORM
503	bool "Support for extended (non-PC) x86 platforms"
504	default y
505	help
506	  If you disable this option then the kernel will only support
507	  standard PC platforms. (which covers the vast majority of
508	  systems out there.)
509
510	  If you enable this option then you'll be able to select support
511	  for the following (non-PC) 32 bit x86 platforms:
512		Goldfish (Android emulator)
513		AMD Elan
514		RDC R-321x SoC
515		SGI 320/540 (Visual Workstation)
516		STA2X11-based (e.g. Northville)
517		Moorestown MID devices
518
519	  If you have one of these systems, or if you want to build a
520	  generic distribution kernel, say Y here - otherwise say N.
521endif # X86_32
522
523if X86_64
524config X86_EXTENDED_PLATFORM
525	bool "Support for extended (non-PC) x86 platforms"
526	default y
527	help
528	  If you disable this option then the kernel will only support
529	  standard PC platforms. (which covers the vast majority of
530	  systems out there.)
531
532	  If you enable this option then you'll be able to select support
533	  for the following (non-PC) 64 bit x86 platforms:
534		Numascale NumaChip
535		ScaleMP vSMP
536		SGI Ultraviolet
537
538	  If you have one of these systems, or if you want to build a
539	  generic distribution kernel, say Y here - otherwise say N.
540endif # X86_64
541# This is an alphabetically sorted list of 64 bit extended platforms
542# Please maintain the alphabetic order if and when there are additions
543config X86_NUMACHIP
544	bool "Numascale NumaChip"
545	depends on X86_64
546	depends on X86_EXTENDED_PLATFORM
547	depends on NUMA
548	depends on SMP
549	depends on X86_X2APIC
550	depends on PCI_MMCONFIG
551	help
552	  Adds support for Numascale NumaChip large-SMP systems. Needed to
553	  enable more than ~168 cores.
554	  If you don't have one of these, you should say N here.
555
556config X86_VSMP
557	bool "ScaleMP vSMP"
558	select HYPERVISOR_GUEST
559	select PARAVIRT
560	depends on X86_64 && PCI
561	depends on X86_EXTENDED_PLATFORM
562	depends on SMP
563	help
564	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
565	  supposed to run on these EM64T-based machines.  Only choose this option
566	  if you have one of these machines.
567
568config X86_UV
569	bool "SGI Ultraviolet"
570	depends on X86_64
571	depends on X86_EXTENDED_PLATFORM
572	depends on NUMA
573	depends on EFI
574	depends on KEXEC_CORE
575	depends on X86_X2APIC
576	depends on PCI
577	help
578	  This option is needed in order to support SGI Ultraviolet systems.
579	  If you don't have one of these, you should say N here.
580
581# Following is an alphabetically sorted list of 32 bit extended platforms
582# Please maintain the alphabetic order if and when there are additions
583
584config X86_GOLDFISH
585	bool "Goldfish (Virtual Platform)"
586	depends on X86_EXTENDED_PLATFORM
587	help
588	  Enable support for the Goldfish virtual platform used primarily
589	  for Android development. Unless you are building for the Android
590	  Goldfish emulator say N here.
591
592config X86_INTEL_CE
593	bool "CE4100 TV platform"
594	depends on PCI
595	depends on PCI_GODIRECT
596	depends on X86_IO_APIC
597	depends on X86_32
598	depends on X86_EXTENDED_PLATFORM
599	select X86_REBOOTFIXUPS
600	select OF
601	select OF_EARLY_FLATTREE
602	help
603	  Select for the Intel CE media processor (CE4100) SOC.
604	  This option compiles in support for the CE4100 SOC for settop
605	  boxes and media devices.
606
607config X86_INTEL_MID
608	bool "Intel MID platform support"
609	depends on X86_EXTENDED_PLATFORM
610	depends on X86_PLATFORM_DEVICES
611	depends on PCI
612	depends on X86_64 || (PCI_GOANY && X86_32)
613	depends on X86_IO_APIC
614	select I2C
615	select DW_APB_TIMER
616	select INTEL_SCU_PCI
617	help
618	  Select to build a kernel capable of supporting Intel MID (Mobile
619	  Internet Device) platform systems which do not have the PCI legacy
620	  interfaces. If you are building for a PC class system say N here.
621
622	  Intel MID platforms are based on an Intel processor and chipset which
623	  consume less power than most of the x86 derivatives.
624
625config X86_INTEL_QUARK
626	bool "Intel Quark platform support"
627	depends on X86_32
628	depends on X86_EXTENDED_PLATFORM
629	depends on X86_PLATFORM_DEVICES
630	depends on X86_TSC
631	depends on PCI
632	depends on PCI_GOANY
633	depends on X86_IO_APIC
634	select IOSF_MBI
635	select INTEL_IMR
636	select COMMON_CLK
637	help
638	  Select to include support for Quark X1000 SoC.
639	  Say Y here if you have a Quark based system such as the Arduino
640	  compatible Intel Galileo.
641
642config X86_INTEL_LPSS
643	bool "Intel Low Power Subsystem Support"
644	depends on X86 && ACPI && PCI
645	select COMMON_CLK
646	select PINCTRL
647	select IOSF_MBI
648	help
649	  Select to build support for Intel Low Power Subsystem such as
650	  found on Intel Lynxpoint PCH. Selecting this option enables
651	  things like clock tree (common clock framework) and pincontrol
652	  which are needed by the LPSS peripheral drivers.
653
654config X86_AMD_PLATFORM_DEVICE
655	bool "AMD ACPI2Platform devices support"
656	depends on ACPI
657	select COMMON_CLK
658	select PINCTRL
659	help
660	  Select to interpret AMD specific ACPI device to platform device
661	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
662	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
663	  implemented under PINCTRL subsystem.
664
665config IOSF_MBI
666	tristate "Intel SoC IOSF Sideband support for SoC platforms"
667	depends on PCI
668	help
669	  This option enables sideband register access support for Intel SoC
670	  platforms. On these platforms the IOSF sideband is used in lieu of
671	  MSR's for some register accesses, mostly but not limited to thermal
672	  and power. Drivers may query the availability of this device to
673	  determine if they need the sideband in order to work on these
674	  platforms. The sideband is available on the following SoC products.
675	  This list is not meant to be exclusive.
676	   - BayTrail
677	   - Braswell
678	   - Quark
679
680	  You should say Y if you are running a kernel on one of these SoC's.
681
682config IOSF_MBI_DEBUG
683	bool "Enable IOSF sideband access through debugfs"
684	depends on IOSF_MBI && DEBUG_FS
685	help
686	  Select this option to expose the IOSF sideband access registers (MCR,
687	  MDR, MCRX) through debugfs to write and read register information from
688	  different units on the SoC. This is most useful for obtaining device
689	  state information for debug and analysis. As this is a general access
690	  mechanism, users of this option would have specific knowledge of the
691	  device they want to access.
692
693	  If you don't require the option or are in doubt, say N.
694
695config X86_RDC321X
696	bool "RDC R-321x SoC"
697	depends on X86_32
698	depends on X86_EXTENDED_PLATFORM
699	select M486
700	select X86_REBOOTFIXUPS
701	help
702	  This option is needed for RDC R-321x system-on-chip, also known
703	  as R-8610-(G).
704	  If you don't have one of these chips, you should say N here.
705
706config X86_32_NON_STANDARD
707	bool "Support non-standard 32-bit SMP architectures"
708	depends on X86_32 && SMP
709	depends on X86_EXTENDED_PLATFORM
710	help
711	  This option compiles in the bigsmp and STA2X11 default
712	  subarchitectures.  It is intended for a generic binary
713	  kernel. If you select them all, kernel will probe it one by
714	  one and will fallback to default.
715
716# Alphabetically sorted list of Non standard 32 bit platforms
717
718config X86_SUPPORTS_MEMORY_FAILURE
719	def_bool y
720	# MCE code calls memory_failure():
721	depends on X86_MCE
722	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
723	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
724	depends on X86_64 || !SPARSEMEM
725	select ARCH_SUPPORTS_MEMORY_FAILURE
726
727config STA2X11
728	bool "STA2X11 Companion Chip Support"
729	depends on X86_32_NON_STANDARD && PCI
730	select SWIOTLB
731	select MFD_STA2X11
732	select GPIOLIB
733	help
734	  This adds support for boards based on the STA2X11 IO-Hub,
735	  a.k.a. "ConneXt". The chip is used in place of the standard
736	  PC chipset, so all "standard" peripherals are missing. If this
737	  option is selected the kernel will still be able to boot on
738	  standard PC machines.
739
740config X86_32_IRIS
741	tristate "Eurobraille/Iris poweroff module"
742	depends on X86_32
743	help
744	  The Iris machines from EuroBraille do not have APM or ACPI support
745	  to shut themselves down properly.  A special I/O sequence is
746	  needed to do so, which is what this module does at
747	  kernel shutdown.
748
749	  This is only for Iris machines from EuroBraille.
750
751	  If unused, say N.
752
753config SCHED_OMIT_FRAME_POINTER
754	def_bool y
755	prompt "Single-depth WCHAN output"
756	depends on X86
757	help
758	  Calculate simpler /proc/<PID>/wchan values. If this option
759	  is disabled then wchan values will recurse back to the
760	  caller function. This provides more accurate wchan values,
761	  at the expense of slightly more scheduling overhead.
762
763	  If in doubt, say "Y".
764
765menuconfig HYPERVISOR_GUEST
766	bool "Linux guest support"
767	help
768	  Say Y here to enable options for running Linux under various hyper-
769	  visors. This option enables basic hypervisor detection and platform
770	  setup.
771
772	  If you say N, all options in this submenu will be skipped and
773	  disabled, and Linux guest support won't be built in.
774
775if HYPERVISOR_GUEST
776
777config PARAVIRT
778	bool "Enable paravirtualization code"
779	depends on HAVE_STATIC_CALL
780	help
781	  This changes the kernel so it can modify itself when it is run
782	  under a hypervisor, potentially improving performance significantly
783	  over full virtualization.  However, when run without a hypervisor
784	  the kernel is theoretically slower and slightly larger.
785
786config PARAVIRT_XXL
787	bool
788
789config PARAVIRT_DEBUG
790	bool "paravirt-ops debugging"
791	depends on PARAVIRT && DEBUG_KERNEL
792	help
793	  Enable to debug paravirt_ops internals.  Specifically, BUG if
794	  a paravirt_op is missing when it is called.
795
796config PARAVIRT_SPINLOCKS
797	bool "Paravirtualization layer for spinlocks"
798	depends on PARAVIRT && SMP
799	help
800	  Paravirtualized spinlocks allow a pvops backend to replace the
801	  spinlock implementation with something virtualization-friendly
802	  (for example, block the virtual CPU rather than spinning).
803
804	  It has a minimal impact on native kernels and gives a nice performance
805	  benefit on paravirtualized KVM / Xen kernels.
806
807	  If you are unsure how to answer this question, answer Y.
808
809config X86_HV_CALLBACK_VECTOR
810	def_bool n
811
812source "arch/x86/xen/Kconfig"
813
814config KVM_GUEST
815	bool "KVM Guest support (including kvmclock)"
816	depends on PARAVIRT
817	select PARAVIRT_CLOCK
818	select ARCH_CPUIDLE_HALTPOLL
819	select X86_HV_CALLBACK_VECTOR
820	default y
821	help
822	  This option enables various optimizations for running under the KVM
823	  hypervisor. It includes a paravirtualized clock, so that instead
824	  of relying on a PIT (or probably other) emulation by the
825	  underlying device model, the host provides the guest with
826	  timing infrastructure such as time of day, and system time
827
828config ARCH_CPUIDLE_HALTPOLL
829	def_bool n
830	prompt "Disable host haltpoll when loading haltpoll driver"
831	help
832	  If virtualized under KVM, disable host haltpoll.
833
834config PVH
835	bool "Support for running PVH guests"
836	help
837	  This option enables the PVH entry point for guest virtual machines
838	  as specified in the x86/HVM direct boot ABI.
839
840config PARAVIRT_TIME_ACCOUNTING
841	bool "Paravirtual steal time accounting"
842	depends on PARAVIRT
843	help
844	  Select this option to enable fine granularity task steal time
845	  accounting. Time spent executing other tasks in parallel with
846	  the current vCPU is discounted from the vCPU power. To account for
847	  that, there can be a small performance impact.
848
849	  If in doubt, say N here.
850
851config PARAVIRT_CLOCK
852	bool
853
854config JAILHOUSE_GUEST
855	bool "Jailhouse non-root cell support"
856	depends on X86_64 && PCI
857	select X86_PM_TIMER
858	help
859	  This option allows to run Linux as guest in a Jailhouse non-root
860	  cell. You can leave this option disabled if you only want to start
861	  Jailhouse and run Linux afterwards in the root cell.
862
863config ACRN_GUEST
864	bool "ACRN Guest support"
865	depends on X86_64
866	select X86_HV_CALLBACK_VECTOR
867	help
868	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
869	  a flexible, lightweight reference open-source hypervisor, built with
870	  real-time and safety-criticality in mind. It is built for embedded
871	  IOT with small footprint and real-time features. More details can be
872	  found in https://projectacrn.org/.
873
874config INTEL_TDX_GUEST
875	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
876	depends on X86_64 && CPU_SUP_INTEL
877	depends on X86_X2APIC
878	depends on EFI_STUB
879	select ARCH_HAS_CC_PLATFORM
880	select X86_MEM_ENCRYPT
881	select X86_MCE
882	select UNACCEPTED_MEMORY
883	help
884	  Support running as a guest under Intel TDX.  Without this support,
885	  the guest kernel can not boot or run under TDX.
886	  TDX includes memory encryption and integrity capabilities
887	  which protect the confidentiality and integrity of guest
888	  memory contents and CPU state. TDX guests are protected from
889	  some attacks from the VMM.
890
891endif # HYPERVISOR_GUEST
892
893source "arch/x86/Kconfig.cpu"
894
895config HPET_TIMER
896	def_bool X86_64
897	prompt "HPET Timer Support" if X86_32
898	help
899	  Use the IA-PC HPET (High Precision Event Timer) to manage
900	  time in preference to the PIT and RTC, if a HPET is
901	  present.
902	  HPET is the next generation timer replacing legacy 8254s.
903	  The HPET provides a stable time base on SMP
904	  systems, unlike the TSC, but it is more expensive to access,
905	  as it is off-chip.  The interface used is documented
906	  in the HPET spec, revision 1.
907
908	  You can safely choose Y here.  However, HPET will only be
909	  activated if the platform and the BIOS support this feature.
910	  Otherwise the 8254 will be used for timing services.
911
912	  Choose N to continue using the legacy 8254 timer.
913
914config HPET_EMULATE_RTC
915	def_bool y
916	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
917
918# Mark as expert because too many people got it wrong.
919# The code disables itself when not needed.
920config DMI
921	default y
922	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
923	bool "Enable DMI scanning" if EXPERT
924	help
925	  Enabled scanning of DMI to identify machine quirks. Say Y
926	  here unless you have verified that your setup is not
927	  affected by entries in the DMI blacklist. Required by PNP
928	  BIOS code.
929
930config GART_IOMMU
931	bool "Old AMD GART IOMMU support"
932	select DMA_OPS
933	select IOMMU_HELPER
934	select SWIOTLB
935	depends on X86_64 && PCI && AMD_NB
936	help
937	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
938	  GART based hardware IOMMUs.
939
940	  The GART supports full DMA access for devices with 32-bit access
941	  limitations, on systems with more than 3 GB. This is usually needed
942	  for USB, sound, many IDE/SATA chipsets and some other devices.
943
944	  Newer systems typically have a modern AMD IOMMU, supported via
945	  the CONFIG_AMD_IOMMU=y config option.
946
947	  In normal configurations this driver is only active when needed:
948	  there's more than 3 GB of memory and the system contains a
949	  32-bit limited device.
950
951	  If unsure, say Y.
952
953config BOOT_VESA_SUPPORT
954	bool
955	help
956	  If true, at least one selected framebuffer driver can take advantage
957	  of VESA video modes set at an early boot stage via the vga= parameter.
958
959config MAXSMP
960	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
961	depends on X86_64 && SMP && DEBUG_KERNEL
962	select CPUMASK_OFFSTACK
963	help
964	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
965	  If unsure, say N.
966
967#
968# The maximum number of CPUs supported:
969#
970# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
971# and which can be configured interactively in the
972# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
973#
974# The ranges are different on 32-bit and 64-bit kernels, depending on
975# hardware capabilities and scalability features of the kernel.
976#
977# ( If MAXSMP is enabled we just use the highest possible value and disable
978#   interactive configuration. )
979#
980
981config NR_CPUS_RANGE_BEGIN
982	int
983	default NR_CPUS_RANGE_END if MAXSMP
984	default    1 if !SMP
985	default    2
986
987config NR_CPUS_RANGE_END
988	int
989	depends on X86_32
990	default   64 if  SMP &&  X86_BIGSMP
991	default    8 if  SMP && !X86_BIGSMP
992	default    1 if !SMP
993
994config NR_CPUS_RANGE_END
995	int
996	depends on X86_64
997	default 8192 if  SMP && CPUMASK_OFFSTACK
998	default  512 if  SMP && !CPUMASK_OFFSTACK
999	default    1 if !SMP
1000
1001config NR_CPUS_DEFAULT
1002	int
1003	depends on X86_32
1004	default   32 if  X86_BIGSMP
1005	default    8 if  SMP
1006	default    1 if !SMP
1007
1008config NR_CPUS_DEFAULT
1009	int
1010	depends on X86_64
1011	default 8192 if  MAXSMP
1012	default   64 if  SMP
1013	default    1 if !SMP
1014
1015config NR_CPUS
1016	int "Maximum number of CPUs" if SMP && !MAXSMP
1017	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1018	default NR_CPUS_DEFAULT
1019	help
1020	  This allows you to specify the maximum number of CPUs which this
1021	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1022	  supported value is 8192, otherwise the maximum value is 512.  The
1023	  minimum value which makes sense is 2.
1024
1025	  This is purely to save memory: each supported CPU adds about 8KB
1026	  to the kernel image.
1027
1028config SCHED_CLUSTER
1029	bool "Cluster scheduler support"
1030	depends on SMP
1031	default y
1032	help
1033	  Cluster scheduler support improves the CPU scheduler's decision
1034	  making when dealing with machines that have clusters of CPUs.
1035	  Cluster usually means a couple of CPUs which are placed closely
1036	  by sharing mid-level caches, last-level cache tags or internal
1037	  busses.
1038
1039config SCHED_SMT
1040	def_bool y if SMP
1041
1042config SCHED_MC
1043	def_bool y
1044	prompt "Multi-core scheduler support"
1045	depends on SMP
1046	help
1047	  Multi-core scheduler support improves the CPU scheduler's decision
1048	  making when dealing with multi-core CPU chips at a cost of slightly
1049	  increased overhead in some places. If unsure say N here.
1050
1051config SCHED_MC_PRIO
1052	bool "CPU core priorities scheduler support"
1053	depends on SCHED_MC && CPU_SUP_INTEL
1054	select X86_INTEL_PSTATE
1055	select CPU_FREQ
1056	default y
1057	help
1058	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1059	  core ordering determined at manufacturing time, which allows
1060	  certain cores to reach higher turbo frequencies (when running
1061	  single threaded workloads) than others.
1062
1063	  Enabling this kernel feature teaches the scheduler about
1064	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1065	  scheduler's CPU selection logic accordingly, so that higher
1066	  overall system performance can be achieved.
1067
1068	  This feature will have no effect on CPUs without this feature.
1069
1070	  If unsure say Y here.
1071
1072config UP_LATE_INIT
1073	def_bool y
1074	depends on !SMP && X86_LOCAL_APIC
1075
1076config X86_UP_APIC
1077	bool "Local APIC support on uniprocessors" if !PCI_MSI
1078	default PCI_MSI
1079	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1080	help
1081	  A local APIC (Advanced Programmable Interrupt Controller) is an
1082	  integrated interrupt controller in the CPU. If you have a single-CPU
1083	  system which has a processor with a local APIC, you can say Y here to
1084	  enable and use it. If you say Y here even though your machine doesn't
1085	  have a local APIC, then the kernel will still run with no slowdown at
1086	  all. The local APIC supports CPU-generated self-interrupts (timer,
1087	  performance counters), and the NMI watchdog which detects hard
1088	  lockups.
1089
1090config X86_UP_IOAPIC
1091	bool "IO-APIC support on uniprocessors"
1092	depends on X86_UP_APIC
1093	help
1094	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1095	  SMP-capable replacement for PC-style interrupt controllers. Most
1096	  SMP systems and many recent uniprocessor systems have one.
1097
1098	  If you have a single-CPU system with an IO-APIC, you can say Y here
1099	  to use it. If you say Y here even though your machine doesn't have
1100	  an IO-APIC, then the kernel will still run with no slowdown at all.
1101
1102config X86_LOCAL_APIC
1103	def_bool y
1104	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1105	select IRQ_DOMAIN_HIERARCHY
1106
1107config X86_IO_APIC
1108	def_bool y
1109	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1110
1111config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1112	bool "Reroute for broken boot IRQs"
1113	depends on X86_IO_APIC
1114	help
1115	  This option enables a workaround that fixes a source of
1116	  spurious interrupts. This is recommended when threaded
1117	  interrupt handling is used on systems where the generation of
1118	  superfluous "boot interrupts" cannot be disabled.
1119
1120	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1121	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1122	  kernel does during interrupt handling). On chipsets where this
1123	  boot IRQ generation cannot be disabled, this workaround keeps
1124	  the original IRQ line masked so that only the equivalent "boot
1125	  IRQ" is delivered to the CPUs. The workaround also tells the
1126	  kernel to set up the IRQ handler on the boot IRQ line. In this
1127	  way only one interrupt is delivered to the kernel. Otherwise
1128	  the spurious second interrupt may cause the kernel to bring
1129	  down (vital) interrupt lines.
1130
1131	  Only affects "broken" chipsets. Interrupt sharing may be
1132	  increased on these systems.
1133
1134config X86_MCE
1135	bool "Machine Check / overheating reporting"
1136	select GENERIC_ALLOCATOR
1137	default y
1138	help
1139	  Machine Check support allows the processor to notify the
1140	  kernel if it detects a problem (e.g. overheating, data corruption).
1141	  The action the kernel takes depends on the severity of the problem,
1142	  ranging from warning messages to halting the machine.
1143
1144config X86_MCELOG_LEGACY
1145	bool "Support for deprecated /dev/mcelog character device"
1146	depends on X86_MCE
1147	help
1148	  Enable support for /dev/mcelog which is needed by the old mcelog
1149	  userspace logging daemon. Consider switching to the new generation
1150	  rasdaemon solution.
1151
1152config X86_MCE_INTEL
1153	def_bool y
1154	prompt "Intel MCE features"
1155	depends on X86_MCE && X86_LOCAL_APIC
1156	help
1157	  Additional support for intel specific MCE features such as
1158	  the thermal monitor.
1159
1160config X86_MCE_AMD
1161	def_bool y
1162	prompt "AMD MCE features"
1163	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1164	help
1165	  Additional support for AMD specific MCE features such as
1166	  the DRAM Error Threshold.
1167
1168config X86_ANCIENT_MCE
1169	bool "Support for old Pentium 5 / WinChip machine checks"
1170	depends on X86_32 && X86_MCE
1171	help
1172	  Include support for machine check handling on old Pentium 5 or WinChip
1173	  systems. These typically need to be enabled explicitly on the command
1174	  line.
1175
1176config X86_MCE_THRESHOLD
1177	depends on X86_MCE_AMD || X86_MCE_INTEL
1178	def_bool y
1179
1180config X86_MCE_INJECT
1181	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1182	tristate "Machine check injector support"
1183	help
1184	  Provide support for injecting machine checks for testing purposes.
1185	  If you don't know what a machine check is and you don't do kernel
1186	  QA it is safe to say n.
1187
1188source "arch/x86/events/Kconfig"
1189
1190config X86_LEGACY_VM86
1191	bool "Legacy VM86 support"
1192	depends on X86_32
1193	help
1194	  This option allows user programs to put the CPU into V8086
1195	  mode, which is an 80286-era approximation of 16-bit real mode.
1196
1197	  Some very old versions of X and/or vbetool require this option
1198	  for user mode setting.  Similarly, DOSEMU will use it if
1199	  available to accelerate real mode DOS programs.  However, any
1200	  recent version of DOSEMU, X, or vbetool should be fully
1201	  functional even without kernel VM86 support, as they will all
1202	  fall back to software emulation. Nevertheless, if you are using
1203	  a 16-bit DOS program where 16-bit performance matters, vm86
1204	  mode might be faster than emulation and you might want to
1205	  enable this option.
1206
1207	  Note that any app that works on a 64-bit kernel is unlikely to
1208	  need this option, as 64-bit kernels don't, and can't, support
1209	  V8086 mode. This option is also unrelated to 16-bit protected
1210	  mode and is not needed to run most 16-bit programs under Wine.
1211
1212	  Enabling this option increases the complexity of the kernel
1213	  and slows down exception handling a tiny bit.
1214
1215	  If unsure, say N here.
1216
1217config VM86
1218	bool
1219	default X86_LEGACY_VM86
1220
1221config X86_16BIT
1222	bool "Enable support for 16-bit segments" if EXPERT
1223	default y
1224	depends on MODIFY_LDT_SYSCALL
1225	help
1226	  This option is required by programs like Wine to run 16-bit
1227	  protected mode legacy code on x86 processors.  Disabling
1228	  this option saves about 300 bytes on i386, or around 6K text
1229	  plus 16K runtime memory on x86-64,
1230
1231config X86_ESPFIX32
1232	def_bool y
1233	depends on X86_16BIT && X86_32
1234
1235config X86_ESPFIX64
1236	def_bool y
1237	depends on X86_16BIT && X86_64
1238
1239config X86_VSYSCALL_EMULATION
1240	bool "Enable vsyscall emulation" if EXPERT
1241	default y
1242	depends on X86_64
1243	help
1244	  This enables emulation of the legacy vsyscall page.  Disabling
1245	  it is roughly equivalent to booting with vsyscall=none, except
1246	  that it will also disable the helpful warning if a program
1247	  tries to use a vsyscall.  With this option set to N, offending
1248	  programs will just segfault, citing addresses of the form
1249	  0xffffffffff600?00.
1250
1251	  This option is required by many programs built before 2013, and
1252	  care should be used even with newer programs if set to N.
1253
1254	  Disabling this option saves about 7K of kernel size and
1255	  possibly 4K of additional runtime pagetable memory.
1256
1257config X86_IOPL_IOPERM
1258	bool "IOPERM and IOPL Emulation"
1259	default y
1260	help
1261	  This enables the ioperm() and iopl() syscalls which are necessary
1262	  for legacy applications.
1263
1264	  Legacy IOPL support is an overbroad mechanism which allows user
1265	  space aside of accessing all 65536 I/O ports also to disable
1266	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1267	  capabilities and permission from potentially active security
1268	  modules.
1269
1270	  The emulation restricts the functionality of the syscall to
1271	  only allowing the full range I/O port access, but prevents the
1272	  ability to disable interrupts from user space which would be
1273	  granted if the hardware IOPL mechanism would be used.
1274
1275config TOSHIBA
1276	tristate "Toshiba Laptop support"
1277	depends on X86_32
1278	help
1279	  This adds a driver to safely access the System Management Mode of
1280	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1281	  not work on models with a Phoenix BIOS. The System Management Mode
1282	  is used to set the BIOS and power saving options on Toshiba portables.
1283
1284	  For information on utilities to make use of this driver see the
1285	  Toshiba Linux utilities web site at:
1286	  <http://www.buzzard.org.uk/toshiba/>.
1287
1288	  Say Y if you intend to run this kernel on a Toshiba portable.
1289	  Say N otherwise.
1290
1291config X86_REBOOTFIXUPS
1292	bool "Enable X86 board specific fixups for reboot"
1293	depends on X86_32
1294	help
1295	  This enables chipset and/or board specific fixups to be done
1296	  in order to get reboot to work correctly. This is only needed on
1297	  some combinations of hardware and BIOS. The symptom, for which
1298	  this config is intended, is when reboot ends with a stalled/hung
1299	  system.
1300
1301	  Currently, the only fixup is for the Geode machines using
1302	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1303
1304	  Say Y if you want to enable the fixup. Currently, it's safe to
1305	  enable this option even if you don't need it.
1306	  Say N otherwise.
1307
1308config MICROCODE
1309	bool "CPU microcode loading support"
1310	default y
1311	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1312	help
1313	  If you say Y here, you will be able to update the microcode on
1314	  Intel and AMD processors. The Intel support is for the IA32 family,
1315	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1316	  AMD support is for families 0x10 and later. You will obviously need
1317	  the actual microcode binary data itself which is not shipped with
1318	  the Linux kernel.
1319
1320	  The preferred method to load microcode from a detached initrd is described
1321	  in Documentation/arch/x86/microcode.rst. For that you need to enable
1322	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1323	  initrd for microcode blobs.
1324
1325	  In addition, you can build the microcode into the kernel. For that you
1326	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1327	  config option.
1328
1329config MICROCODE_INTEL
1330	bool "Intel microcode loading support"
1331	depends on CPU_SUP_INTEL && MICROCODE
1332	default MICROCODE
1333	help
1334	  This options enables microcode patch loading support for Intel
1335	  processors.
1336
1337	  For the current Intel microcode data package go to
1338	  <https://downloadcenter.intel.com> and search for
1339	  'Linux Processor Microcode Data File'.
1340
1341config MICROCODE_AMD
1342	bool "AMD microcode loading support"
1343	depends on CPU_SUP_AMD && MICROCODE
1344	help
1345	  If you select this option, microcode patch loading support for AMD
1346	  processors will be enabled.
1347
1348config MICROCODE_LATE_LOADING
1349	bool "Late microcode loading (DANGEROUS)"
1350	default n
1351	depends on MICROCODE
1352	help
1353	  Loading microcode late, when the system is up and executing instructions
1354	  is a tricky business and should be avoided if possible. Just the sequence
1355	  of synchronizing all cores and SMT threads is one fragile dance which does
1356	  not guarantee that cores might not softlock after the loading. Therefore,
1357	  use this at your own risk. Late loading taints the kernel too.
1358
1359config X86_MSR
1360	tristate "/dev/cpu/*/msr - Model-specific register support"
1361	help
1362	  This device gives privileged processes access to the x86
1363	  Model-Specific Registers (MSRs).  It is a character device with
1364	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1365	  MSR accesses are directed to a specific CPU on multi-processor
1366	  systems.
1367
1368config X86_CPUID
1369	tristate "/dev/cpu/*/cpuid - CPU information support"
1370	help
1371	  This device gives processes access to the x86 CPUID instruction to
1372	  be executed on a specific processor.  It is a character device
1373	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1374	  /dev/cpu/31/cpuid.
1375
1376choice
1377	prompt "High Memory Support"
1378	default HIGHMEM4G
1379	depends on X86_32
1380
1381config NOHIGHMEM
1382	bool "off"
1383	help
1384	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1385	  However, the address space of 32-bit x86 processors is only 4
1386	  Gigabytes large. That means that, if you have a large amount of
1387	  physical memory, not all of it can be "permanently mapped" by the
1388	  kernel. The physical memory that's not permanently mapped is called
1389	  "high memory".
1390
1391	  If you are compiling a kernel which will never run on a machine with
1392	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1393	  choice and suitable for most users). This will result in a "3GB/1GB"
1394	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1395	  space and the remaining part of the 4GB virtual memory space is used
1396	  by the kernel to permanently map as much physical memory as
1397	  possible.
1398
1399	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1400	  answer "4GB" here.
1401
1402	  If more than 4 Gigabytes is used then answer "64GB" here. This
1403	  selection turns Intel PAE (Physical Address Extension) mode on.
1404	  PAE implements 3-level paging on IA32 processors. PAE is fully
1405	  supported by Linux, PAE mode is implemented on all recent Intel
1406	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1407	  then the kernel will not boot on CPUs that don't support PAE!
1408
1409	  The actual amount of total physical memory will either be
1410	  auto detected or can be forced by using a kernel command line option
1411	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1412	  your boot loader (lilo or loadlin) about how to pass options to the
1413	  kernel at boot time.)
1414
1415	  If unsure, say "off".
1416
1417config HIGHMEM4G
1418	bool "4GB"
1419	help
1420	  Select this if you have a 32-bit processor and between 1 and 4
1421	  gigabytes of physical RAM.
1422
1423config HIGHMEM64G
1424	bool "64GB"
1425	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1426	select X86_PAE
1427	help
1428	  Select this if you have a 32-bit processor and more than 4
1429	  gigabytes of physical RAM.
1430
1431endchoice
1432
1433choice
1434	prompt "Memory split" if EXPERT
1435	default VMSPLIT_3G
1436	depends on X86_32
1437	help
1438	  Select the desired split between kernel and user memory.
1439
1440	  If the address range available to the kernel is less than the
1441	  physical memory installed, the remaining memory will be available
1442	  as "high memory". Accessing high memory is a little more costly
1443	  than low memory, as it needs to be mapped into the kernel first.
1444	  Note that increasing the kernel address space limits the range
1445	  available to user programs, making the address space there
1446	  tighter.  Selecting anything other than the default 3G/1G split
1447	  will also likely make your kernel incompatible with binary-only
1448	  kernel modules.
1449
1450	  If you are not absolutely sure what you are doing, leave this
1451	  option alone!
1452
1453	config VMSPLIT_3G
1454		bool "3G/1G user/kernel split"
1455	config VMSPLIT_3G_OPT
1456		depends on !X86_PAE
1457		bool "3G/1G user/kernel split (for full 1G low memory)"
1458	config VMSPLIT_2G
1459		bool "2G/2G user/kernel split"
1460	config VMSPLIT_2G_OPT
1461		depends on !X86_PAE
1462		bool "2G/2G user/kernel split (for full 2G low memory)"
1463	config VMSPLIT_1G
1464		bool "1G/3G user/kernel split"
1465endchoice
1466
1467config PAGE_OFFSET
1468	hex
1469	default 0xB0000000 if VMSPLIT_3G_OPT
1470	default 0x80000000 if VMSPLIT_2G
1471	default 0x78000000 if VMSPLIT_2G_OPT
1472	default 0x40000000 if VMSPLIT_1G
1473	default 0xC0000000
1474	depends on X86_32
1475
1476config HIGHMEM
1477	def_bool y
1478	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1479
1480config X86_PAE
1481	bool "PAE (Physical Address Extension) Support"
1482	depends on X86_32 && !HIGHMEM4G
1483	select PHYS_ADDR_T_64BIT
1484	select SWIOTLB
1485	help
1486	  PAE is required for NX support, and furthermore enables
1487	  larger swapspace support for non-overcommit purposes. It
1488	  has the cost of more pagetable lookup overhead, and also
1489	  consumes more pagetable space per process.
1490
1491config X86_5LEVEL
1492	bool "Enable 5-level page tables support"
1493	default y
1494	select DYNAMIC_MEMORY_LAYOUT
1495	select SPARSEMEM_VMEMMAP
1496	depends on X86_64
1497	help
1498	  5-level paging enables access to larger address space:
1499	  up to 128 PiB of virtual address space and 4 PiB of
1500	  physical address space.
1501
1502	  It will be supported by future Intel CPUs.
1503
1504	  A kernel with the option enabled can be booted on machines that
1505	  support 4- or 5-level paging.
1506
1507	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1508	  information.
1509
1510	  Say N if unsure.
1511
1512config X86_DIRECT_GBPAGES
1513	def_bool y
1514	depends on X86_64
1515	help
1516	  Certain kernel features effectively disable kernel
1517	  linear 1 GB mappings (even if the CPU otherwise
1518	  supports them), so don't confuse the user by printing
1519	  that we have them enabled.
1520
1521config X86_CPA_STATISTICS
1522	bool "Enable statistic for Change Page Attribute"
1523	depends on DEBUG_FS
1524	help
1525	  Expose statistics about the Change Page Attribute mechanism, which
1526	  helps to determine the effectiveness of preserving large and huge
1527	  page mappings when mapping protections are changed.
1528
1529config X86_MEM_ENCRYPT
1530	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1531	select DYNAMIC_PHYSICAL_MASK
1532	def_bool n
1533
1534config AMD_MEM_ENCRYPT
1535	bool "AMD Secure Memory Encryption (SME) support"
1536	depends on X86_64 && CPU_SUP_AMD
1537	depends on EFI_STUB
1538	select DMA_COHERENT_POOL
1539	select ARCH_USE_MEMREMAP_PROT
1540	select INSTRUCTION_DECODER
1541	select ARCH_HAS_CC_PLATFORM
1542	select X86_MEM_ENCRYPT
1543	select UNACCEPTED_MEMORY
1544	help
1545	  Say yes to enable support for the encryption of system memory.
1546	  This requires an AMD processor that supports Secure Memory
1547	  Encryption (SME).
1548
1549config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1550	bool "Activate AMD Secure Memory Encryption (SME) by default"
1551	depends on AMD_MEM_ENCRYPT
1552	help
1553	  Say yes to have system memory encrypted by default if running on
1554	  an AMD processor that supports Secure Memory Encryption (SME).
1555
1556	  If set to Y, then the encryption of system memory can be
1557	  deactivated with the mem_encrypt=off command line option.
1558
1559	  If set to N, then the encryption of system memory can be
1560	  activated with the mem_encrypt=on command line option.
1561
1562# Common NUMA Features
1563config NUMA
1564	bool "NUMA Memory Allocation and Scheduler Support"
1565	depends on SMP
1566	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1567	default y if X86_BIGSMP
1568	select USE_PERCPU_NUMA_NODE_ID
1569	help
1570	  Enable NUMA (Non-Uniform Memory Access) support.
1571
1572	  The kernel will try to allocate memory used by a CPU on the
1573	  local memory controller of the CPU and add some more
1574	  NUMA awareness to the kernel.
1575
1576	  For 64-bit this is recommended if the system is Intel Core i7
1577	  (or later), AMD Opteron, or EM64T NUMA.
1578
1579	  For 32-bit this is only needed if you boot a 32-bit
1580	  kernel on a 64-bit NUMA platform.
1581
1582	  Otherwise, you should say N.
1583
1584config AMD_NUMA
1585	def_bool y
1586	prompt "Old style AMD Opteron NUMA detection"
1587	depends on X86_64 && NUMA && PCI
1588	help
1589	  Enable AMD NUMA node topology detection.  You should say Y here if
1590	  you have a multi processor AMD system. This uses an old method to
1591	  read the NUMA configuration directly from the builtin Northbridge
1592	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1593	  which also takes priority if both are compiled in.
1594
1595config X86_64_ACPI_NUMA
1596	def_bool y
1597	prompt "ACPI NUMA detection"
1598	depends on X86_64 && NUMA && ACPI && PCI
1599	select ACPI_NUMA
1600	help
1601	  Enable ACPI SRAT based node topology detection.
1602
1603config NUMA_EMU
1604	bool "NUMA emulation"
1605	depends on NUMA
1606	help
1607	  Enable NUMA emulation. A flat machine will be split
1608	  into virtual nodes when booted with "numa=fake=N", where N is the
1609	  number of nodes. This is only useful for debugging.
1610
1611config NODES_SHIFT
1612	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1613	range 1 10
1614	default "10" if MAXSMP
1615	default "6" if X86_64
1616	default "3"
1617	depends on NUMA
1618	help
1619	  Specify the maximum number of NUMA Nodes available on the target
1620	  system.  Increases memory reserved to accommodate various tables.
1621
1622config ARCH_FLATMEM_ENABLE
1623	def_bool y
1624	depends on X86_32 && !NUMA
1625
1626config ARCH_SPARSEMEM_ENABLE
1627	def_bool y
1628	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1629	select SPARSEMEM_STATIC if X86_32
1630	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1631
1632config ARCH_SPARSEMEM_DEFAULT
1633	def_bool X86_64 || (NUMA && X86_32)
1634
1635config ARCH_SELECT_MEMORY_MODEL
1636	def_bool y
1637	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1638
1639config ARCH_MEMORY_PROBE
1640	bool "Enable sysfs memory/probe interface"
1641	depends on MEMORY_HOTPLUG
1642	help
1643	  This option enables a sysfs memory/probe interface for testing.
1644	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1645	  If you are unsure how to answer this question, answer N.
1646
1647config ARCH_PROC_KCORE_TEXT
1648	def_bool y
1649	depends on X86_64 && PROC_KCORE
1650
1651config ILLEGAL_POINTER_VALUE
1652	hex
1653	default 0 if X86_32
1654	default 0xdead000000000000 if X86_64
1655
1656config X86_PMEM_LEGACY_DEVICE
1657	bool
1658
1659config X86_PMEM_LEGACY
1660	tristate "Support non-standard NVDIMMs and ADR protected memory"
1661	depends on PHYS_ADDR_T_64BIT
1662	depends on BLK_DEV
1663	select X86_PMEM_LEGACY_DEVICE
1664	select NUMA_KEEP_MEMINFO if NUMA
1665	select LIBNVDIMM
1666	help
1667	  Treat memory marked using the non-standard e820 type of 12 as used
1668	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1669	  The kernel will offer these regions to the 'pmem' driver so
1670	  they can be used for persistent storage.
1671
1672	  Say Y if unsure.
1673
1674config HIGHPTE
1675	bool "Allocate 3rd-level pagetables from highmem"
1676	depends on HIGHMEM
1677	help
1678	  The VM uses one page table entry for each page of physical memory.
1679	  For systems with a lot of RAM, this can be wasteful of precious
1680	  low memory.  Setting this option will put user-space page table
1681	  entries in high memory.
1682
1683config X86_CHECK_BIOS_CORRUPTION
1684	bool "Check for low memory corruption"
1685	help
1686	  Periodically check for memory corruption in low memory, which
1687	  is suspected to be caused by BIOS.  Even when enabled in the
1688	  configuration, it is disabled at runtime.  Enable it by
1689	  setting "memory_corruption_check=1" on the kernel command
1690	  line.  By default it scans the low 64k of memory every 60
1691	  seconds; see the memory_corruption_check_size and
1692	  memory_corruption_check_period parameters in
1693	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1694
1695	  When enabled with the default parameters, this option has
1696	  almost no overhead, as it reserves a relatively small amount
1697	  of memory and scans it infrequently.  It both detects corruption
1698	  and prevents it from affecting the running system.
1699
1700	  It is, however, intended as a diagnostic tool; if repeatable
1701	  BIOS-originated corruption always affects the same memory,
1702	  you can use memmap= to prevent the kernel from using that
1703	  memory.
1704
1705config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1706	bool "Set the default setting of memory_corruption_check"
1707	depends on X86_CHECK_BIOS_CORRUPTION
1708	default y
1709	help
1710	  Set whether the default state of memory_corruption_check is
1711	  on or off.
1712
1713config MATH_EMULATION
1714	bool
1715	depends on MODIFY_LDT_SYSCALL
1716	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1717	help
1718	  Linux can emulate a math coprocessor (used for floating point
1719	  operations) if you don't have one. 486DX and Pentium processors have
1720	  a math coprocessor built in, 486SX and 386 do not, unless you added
1721	  a 487DX or 387, respectively. (The messages during boot time can
1722	  give you some hints here ["man dmesg"].) Everyone needs either a
1723	  coprocessor or this emulation.
1724
1725	  If you don't have a math coprocessor, you need to say Y here; if you
1726	  say Y here even though you have a coprocessor, the coprocessor will
1727	  be used nevertheless. (This behavior can be changed with the kernel
1728	  command line option "no387", which comes handy if your coprocessor
1729	  is broken. Try "man bootparam" or see the documentation of your boot
1730	  loader (lilo or loadlin) about how to pass options to the kernel at
1731	  boot time.) This means that it is a good idea to say Y here if you
1732	  intend to use this kernel on different machines.
1733
1734	  More information about the internals of the Linux math coprocessor
1735	  emulation can be found in <file:arch/x86/math-emu/README>.
1736
1737	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1738	  kernel, it won't hurt.
1739
1740config MTRR
1741	def_bool y
1742	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1743	help
1744	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1745	  the Memory Type Range Registers (MTRRs) may be used to control
1746	  processor access to memory ranges. This is most useful if you have
1747	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1748	  allows bus write transfers to be combined into a larger transfer
1749	  before bursting over the PCI/AGP bus. This can increase performance
1750	  of image write operations 2.5 times or more. Saying Y here creates a
1751	  /proc/mtrr file which may be used to manipulate your processor's
1752	  MTRRs. Typically the X server should use this.
1753
1754	  This code has a reasonably generic interface so that similar
1755	  control registers on other processors can be easily supported
1756	  as well:
1757
1758	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1759	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1760	  these, the ARRs are used to emulate the MTRRs.
1761	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1762	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1763	  write-combining. All of these processors are supported by this code
1764	  and it makes sense to say Y here if you have one of them.
1765
1766	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1767	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1768	  can lead to all sorts of problems, so it's good to say Y here.
1769
1770	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1771	  just add about 9 KB to your kernel.
1772
1773	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1774
1775config MTRR_SANITIZER
1776	def_bool y
1777	prompt "MTRR cleanup support"
1778	depends on MTRR
1779	help
1780	  Convert MTRR layout from continuous to discrete, so X drivers can
1781	  add writeback entries.
1782
1783	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1784	  The largest mtrr entry size for a continuous block can be set with
1785	  mtrr_chunk_size.
1786
1787	  If unsure, say Y.
1788
1789config MTRR_SANITIZER_ENABLE_DEFAULT
1790	int "MTRR cleanup enable value (0-1)"
1791	range 0 1
1792	default "0"
1793	depends on MTRR_SANITIZER
1794	help
1795	  Enable mtrr cleanup default value
1796
1797config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1798	int "MTRR cleanup spare reg num (0-7)"
1799	range 0 7
1800	default "1"
1801	depends on MTRR_SANITIZER
1802	help
1803	  mtrr cleanup spare entries default, it can be changed via
1804	  mtrr_spare_reg_nr=N on the kernel command line.
1805
1806config X86_PAT
1807	def_bool y
1808	prompt "x86 PAT support" if EXPERT
1809	depends on MTRR
1810	help
1811	  Use PAT attributes to setup page level cache control.
1812
1813	  PATs are the modern equivalents of MTRRs and are much more
1814	  flexible than MTRRs.
1815
1816	  Say N here if you see bootup problems (boot crash, boot hang,
1817	  spontaneous reboots) or a non-working video driver.
1818
1819	  If unsure, say Y.
1820
1821config ARCH_USES_PG_UNCACHED
1822	def_bool y
1823	depends on X86_PAT
1824
1825config X86_UMIP
1826	def_bool y
1827	prompt "User Mode Instruction Prevention" if EXPERT
1828	help
1829	  User Mode Instruction Prevention (UMIP) is a security feature in
1830	  some x86 processors. If enabled, a general protection fault is
1831	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1832	  executed in user mode. These instructions unnecessarily expose
1833	  information about the hardware state.
1834
1835	  The vast majority of applications do not use these instructions.
1836	  For the very few that do, software emulation is provided in
1837	  specific cases in protected and virtual-8086 modes. Emulated
1838	  results are dummy.
1839
1840config CC_HAS_IBT
1841	# GCC >= 9 and binutils >= 2.29
1842	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1843	# Clang/LLVM >= 14
1844	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1845	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1846	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1847		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1848		  $(as-instr,endbr64)
1849
1850config X86_KERNEL_IBT
1851	prompt "Indirect Branch Tracking"
1852	def_bool y
1853	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1854	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1855	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1856	select OBJTOOL
1857	help
1858	  Build the kernel with support for Indirect Branch Tracking, a
1859	  hardware support course-grain forward-edge Control Flow Integrity
1860	  protection. It enforces that all indirect calls must land on
1861	  an ENDBR instruction, as such, the compiler will instrument the
1862	  code with them to make this happen.
1863
1864	  In addition to building the kernel with IBT, seal all functions that
1865	  are not indirect call targets, avoiding them ever becoming one.
1866
1867	  This requires LTO like objtool runs and will slow down the build. It
1868	  does significantly reduce the number of ENDBR instructions in the
1869	  kernel image.
1870
1871config X86_INTEL_MEMORY_PROTECTION_KEYS
1872	prompt "Memory Protection Keys"
1873	def_bool y
1874	# Note: only available in 64-bit mode
1875	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1876	select ARCH_USES_HIGH_VMA_FLAGS
1877	select ARCH_HAS_PKEYS
1878	help
1879	  Memory Protection Keys provides a mechanism for enforcing
1880	  page-based protections, but without requiring modification of the
1881	  page tables when an application changes protection domains.
1882
1883	  For details, see Documentation/core-api/protection-keys.rst
1884
1885	  If unsure, say y.
1886
1887choice
1888	prompt "TSX enable mode"
1889	depends on CPU_SUP_INTEL
1890	default X86_INTEL_TSX_MODE_OFF
1891	help
1892	  Intel's TSX (Transactional Synchronization Extensions) feature
1893	  allows to optimize locking protocols through lock elision which
1894	  can lead to a noticeable performance boost.
1895
1896	  On the other hand it has been shown that TSX can be exploited
1897	  to form side channel attacks (e.g. TAA) and chances are there
1898	  will be more of those attacks discovered in the future.
1899
1900	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1901	  might override this decision by tsx=on the command line parameter.
1902	  Even with TSX enabled, the kernel will attempt to enable the best
1903	  possible TAA mitigation setting depending on the microcode available
1904	  for the particular machine.
1905
1906	  This option allows to set the default tsx mode between tsx=on, =off
1907	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1908	  details.
1909
1910	  Say off if not sure, auto if TSX is in use but it should be used on safe
1911	  platforms or on if TSX is in use and the security aspect of tsx is not
1912	  relevant.
1913
1914config X86_INTEL_TSX_MODE_OFF
1915	bool "off"
1916	help
1917	  TSX is disabled if possible - equals to tsx=off command line parameter.
1918
1919config X86_INTEL_TSX_MODE_ON
1920	bool "on"
1921	help
1922	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1923	  line parameter.
1924
1925config X86_INTEL_TSX_MODE_AUTO
1926	bool "auto"
1927	help
1928	  TSX is enabled on TSX capable HW that is believed to be safe against
1929	  side channel attacks- equals the tsx=auto command line parameter.
1930endchoice
1931
1932config X86_SGX
1933	bool "Software Guard eXtensions (SGX)"
1934	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1935	depends on CRYPTO=y
1936	depends on CRYPTO_SHA256=y
1937	select MMU_NOTIFIER
1938	select NUMA_KEEP_MEMINFO if NUMA
1939	select XARRAY_MULTI
1940	help
1941	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1942	  that can be used by applications to set aside private regions of code
1943	  and data, referred to as enclaves. An enclave's private memory can
1944	  only be accessed by code running within the enclave. Accesses from
1945	  outside the enclave, including other enclaves, are disallowed by
1946	  hardware.
1947
1948	  If unsure, say N.
1949
1950config EFI
1951	bool "EFI runtime service support"
1952	depends on ACPI
1953	select UCS2_STRING
1954	select EFI_RUNTIME_WRAPPERS
1955	select ARCH_USE_MEMREMAP_PROT
1956	help
1957	  This enables the kernel to use EFI runtime services that are
1958	  available (such as the EFI variable services).
1959
1960	  This option is only useful on systems that have EFI firmware.
1961	  In addition, you should use the latest ELILO loader available
1962	  at <http://elilo.sourceforge.net> in order to take advantage
1963	  of EFI runtime services. However, even with this option, the
1964	  resultant kernel should continue to boot on existing non-EFI
1965	  platforms.
1966
1967config EFI_STUB
1968	bool "EFI stub support"
1969	depends on EFI
1970	select RELOCATABLE
1971	help
1972	  This kernel feature allows a bzImage to be loaded directly
1973	  by EFI firmware without the use of a bootloader.
1974
1975	  See Documentation/admin-guide/efi-stub.rst for more information.
1976
1977config EFI_HANDOVER_PROTOCOL
1978	bool "EFI handover protocol (DEPRECATED)"
1979	depends on EFI_STUB
1980	default y
1981	help
1982	  Select this in order to include support for the deprecated EFI
1983	  handover protocol, which defines alternative entry points into the
1984	  EFI stub.  This is a practice that has no basis in the UEFI
1985	  specification, and requires a priori knowledge on the part of the
1986	  bootloader about Linux/x86 specific ways of passing the command line
1987	  and initrd, and where in memory those assets may be loaded.
1988
1989	  If in doubt, say Y. Even though the corresponding support is not
1990	  present in upstream GRUB or other bootloaders, most distros build
1991	  GRUB with numerous downstream patches applied, and may rely on the
1992	  handover protocol as as result.
1993
1994config EFI_MIXED
1995	bool "EFI mixed-mode support"
1996	depends on EFI_STUB && X86_64
1997	help
1998	  Enabling this feature allows a 64-bit kernel to be booted
1999	  on a 32-bit firmware, provided that your CPU supports 64-bit
2000	  mode.
2001
2002	  Note that it is not possible to boot a mixed-mode enabled
2003	  kernel via the EFI boot stub - a bootloader that supports
2004	  the EFI handover protocol must be used.
2005
2006	  If unsure, say N.
2007
2008config EFI_FAKE_MEMMAP
2009	bool "Enable EFI fake memory map"
2010	depends on EFI
2011	help
2012	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2013	  this parameter, you can add arbitrary attribute to specific memory
2014	  range by updating original (firmware provided) EFI memmap.  This is
2015	  useful for debugging of EFI memmap related feature, e.g., Address
2016	  Range Mirroring feature.
2017
2018config EFI_MAX_FAKE_MEM
2019	int "maximum allowable number of ranges in efi_fake_mem boot option"
2020	depends on EFI_FAKE_MEMMAP
2021	range 1 128
2022	default 8
2023	help
2024	  Maximum allowable number of ranges in efi_fake_mem boot option.
2025	  Ranges can be set up to this value using comma-separated list.
2026	  The default value is 8.
2027
2028config EFI_RUNTIME_MAP
2029	bool "Export EFI runtime maps to sysfs" if EXPERT
2030	depends on EFI
2031	default KEXEC_CORE
2032	help
2033	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2034	  That memory map is required by the 2nd kernel to set up EFI virtual
2035	  mappings after kexec, but can also be used for debugging purposes.
2036
2037	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2038
2039source "kernel/Kconfig.hz"
2040
2041config KEXEC
2042	bool "kexec system call"
2043	select KEXEC_CORE
2044	help
2045	  kexec is a system call that implements the ability to shutdown your
2046	  current kernel, and to start another kernel.  It is like a reboot
2047	  but it is independent of the system firmware.   And like a reboot
2048	  you can start any kernel with it, not just Linux.
2049
2050	  The name comes from the similarity to the exec system call.
2051
2052	  It is an ongoing process to be certain the hardware in a machine
2053	  is properly shutdown, so do not be surprised if this code does not
2054	  initially work for you.  As of this writing the exact hardware
2055	  interface is strongly in flux, so no good recommendation can be
2056	  made.
2057
2058config KEXEC_FILE
2059	bool "kexec file based system call"
2060	select KEXEC_CORE
2061	select HAVE_IMA_KEXEC if IMA
2062	depends on X86_64
2063	depends on CRYPTO=y
2064	depends on CRYPTO_SHA256=y
2065	help
2066	  This is new version of kexec system call. This system call is
2067	  file based and takes file descriptors as system call argument
2068	  for kernel and initramfs as opposed to list of segments as
2069	  accepted by previous system call.
2070
2071config ARCH_HAS_KEXEC_PURGATORY
2072	def_bool KEXEC_FILE
2073
2074config KEXEC_SIG
2075	bool "Verify kernel signature during kexec_file_load() syscall"
2076	depends on KEXEC_FILE
2077	help
2078
2079	  This option makes the kexec_file_load() syscall check for a valid
2080	  signature of the kernel image.  The image can still be loaded without
2081	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2082	  there's a signature that we can check, then it must be valid.
2083
2084	  In addition to this option, you need to enable signature
2085	  verification for the corresponding kernel image type being
2086	  loaded in order for this to work.
2087
2088config KEXEC_SIG_FORCE
2089	bool "Require a valid signature in kexec_file_load() syscall"
2090	depends on KEXEC_SIG
2091	help
2092	  This option makes kernel signature verification mandatory for
2093	  the kexec_file_load() syscall.
2094
2095config KEXEC_BZIMAGE_VERIFY_SIG
2096	bool "Enable bzImage signature verification support"
2097	depends on KEXEC_SIG
2098	depends on SIGNED_PE_FILE_VERIFICATION
2099	select SYSTEM_TRUSTED_KEYRING
2100	help
2101	  Enable bzImage signature verification support.
2102
2103config CRASH_DUMP
2104	bool "kernel crash dumps"
2105	depends on X86_64 || (X86_32 && HIGHMEM)
2106	help
2107	  Generate crash dump after being started by kexec.
2108	  This should be normally only set in special crash dump kernels
2109	  which are loaded in the main kernel with kexec-tools into
2110	  a specially reserved region and then later executed after
2111	  a crash by kdump/kexec. The crash dump kernel must be compiled
2112	  to a memory address not used by the main kernel or BIOS using
2113	  PHYSICAL_START, or it must be built as a relocatable image
2114	  (CONFIG_RELOCATABLE=y).
2115	  For more details see Documentation/admin-guide/kdump/kdump.rst
2116
2117config KEXEC_JUMP
2118	bool "kexec jump"
2119	depends on KEXEC && HIBERNATION
2120	help
2121	  Jump between original kernel and kexeced kernel and invoke
2122	  code in physical address mode via KEXEC
2123
2124config PHYSICAL_START
2125	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2126	default "0x1000000"
2127	help
2128	  This gives the physical address where the kernel is loaded.
2129
2130	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2131	  bzImage will decompress itself to above physical address and
2132	  run from there. Otherwise, bzImage will run from the address where
2133	  it has been loaded by the boot loader and will ignore above physical
2134	  address.
2135
2136	  In normal kdump cases one does not have to set/change this option
2137	  as now bzImage can be compiled as a completely relocatable image
2138	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2139	  address. This option is mainly useful for the folks who don't want
2140	  to use a bzImage for capturing the crash dump and want to use a
2141	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2142	  to be specifically compiled to run from a specific memory area
2143	  (normally a reserved region) and this option comes handy.
2144
2145	  So if you are using bzImage for capturing the crash dump,
2146	  leave the value here unchanged to 0x1000000 and set
2147	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2148	  for capturing the crash dump change this value to start of
2149	  the reserved region.  In other words, it can be set based on
2150	  the "X" value as specified in the "crashkernel=YM@XM"
2151	  command line boot parameter passed to the panic-ed
2152	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2153	  for more details about crash dumps.
2154
2155	  Usage of bzImage for capturing the crash dump is recommended as
2156	  one does not have to build two kernels. Same kernel can be used
2157	  as production kernel and capture kernel. Above option should have
2158	  gone away after relocatable bzImage support is introduced. But it
2159	  is present because there are users out there who continue to use
2160	  vmlinux for dump capture. This option should go away down the
2161	  line.
2162
2163	  Don't change this unless you know what you are doing.
2164
2165config RELOCATABLE
2166	bool "Build a relocatable kernel"
2167	default y
2168	help
2169	  This builds a kernel image that retains relocation information
2170	  so it can be loaded someplace besides the default 1MB.
2171	  The relocations tend to make the kernel binary about 10% larger,
2172	  but are discarded at runtime.
2173
2174	  One use is for the kexec on panic case where the recovery kernel
2175	  must live at a different physical address than the primary
2176	  kernel.
2177
2178	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2179	  it has been loaded at and the compile time physical address
2180	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2181
2182config RANDOMIZE_BASE
2183	bool "Randomize the address of the kernel image (KASLR)"
2184	depends on RELOCATABLE
2185	default y
2186	help
2187	  In support of Kernel Address Space Layout Randomization (KASLR),
2188	  this randomizes the physical address at which the kernel image
2189	  is decompressed and the virtual address where the kernel
2190	  image is mapped, as a security feature that deters exploit
2191	  attempts relying on knowledge of the location of kernel
2192	  code internals.
2193
2194	  On 64-bit, the kernel physical and virtual addresses are
2195	  randomized separately. The physical address will be anywhere
2196	  between 16MB and the top of physical memory (up to 64TB). The
2197	  virtual address will be randomized from 16MB up to 1GB (9 bits
2198	  of entropy). Note that this also reduces the memory space
2199	  available to kernel modules from 1.5GB to 1GB.
2200
2201	  On 32-bit, the kernel physical and virtual addresses are
2202	  randomized together. They will be randomized from 16MB up to
2203	  512MB (8 bits of entropy).
2204
2205	  Entropy is generated using the RDRAND instruction if it is
2206	  supported. If RDTSC is supported, its value is mixed into
2207	  the entropy pool as well. If neither RDRAND nor RDTSC are
2208	  supported, then entropy is read from the i8254 timer. The
2209	  usable entropy is limited by the kernel being built using
2210	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2211	  minimum of 2MB. As a result, only 10 bits of entropy are
2212	  theoretically possible, but the implementations are further
2213	  limited due to memory layouts.
2214
2215	  If unsure, say Y.
2216
2217# Relocation on x86 needs some additional build support
2218config X86_NEED_RELOCS
2219	def_bool y
2220	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2221
2222config PHYSICAL_ALIGN
2223	hex "Alignment value to which kernel should be aligned"
2224	default "0x200000"
2225	range 0x2000 0x1000000 if X86_32
2226	range 0x200000 0x1000000 if X86_64
2227	help
2228	  This value puts the alignment restrictions on physical address
2229	  where kernel is loaded and run from. Kernel is compiled for an
2230	  address which meets above alignment restriction.
2231
2232	  If bootloader loads the kernel at a non-aligned address and
2233	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2234	  address aligned to above value and run from there.
2235
2236	  If bootloader loads the kernel at a non-aligned address and
2237	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2238	  load address and decompress itself to the address it has been
2239	  compiled for and run from there. The address for which kernel is
2240	  compiled already meets above alignment restrictions. Hence the
2241	  end result is that kernel runs from a physical address meeting
2242	  above alignment restrictions.
2243
2244	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2245	  this value must be a multiple of 0x200000.
2246
2247	  Don't change this unless you know what you are doing.
2248
2249config DYNAMIC_MEMORY_LAYOUT
2250	bool
2251	help
2252	  This option makes base addresses of vmalloc and vmemmap as well as
2253	  __PAGE_OFFSET movable during boot.
2254
2255config RANDOMIZE_MEMORY
2256	bool "Randomize the kernel memory sections"
2257	depends on X86_64
2258	depends on RANDOMIZE_BASE
2259	select DYNAMIC_MEMORY_LAYOUT
2260	default RANDOMIZE_BASE
2261	help
2262	  Randomizes the base virtual address of kernel memory sections
2263	  (physical memory mapping, vmalloc & vmemmap). This security feature
2264	  makes exploits relying on predictable memory locations less reliable.
2265
2266	  The order of allocations remains unchanged. Entropy is generated in
2267	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2268	  configuration have in average 30,000 different possible virtual
2269	  addresses for each memory section.
2270
2271	  If unsure, say Y.
2272
2273config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2274	hex "Physical memory mapping padding" if EXPERT
2275	depends on RANDOMIZE_MEMORY
2276	default "0xa" if MEMORY_HOTPLUG
2277	default "0x0"
2278	range 0x1 0x40 if MEMORY_HOTPLUG
2279	range 0x0 0x40
2280	help
2281	  Define the padding in terabytes added to the existing physical
2282	  memory size during kernel memory randomization. It is useful
2283	  for memory hotplug support but reduces the entropy available for
2284	  address randomization.
2285
2286	  If unsure, leave at the default value.
2287
2288config ADDRESS_MASKING
2289	bool "Linear Address Masking support"
2290	depends on X86_64
2291	help
2292	  Linear Address Masking (LAM) modifies the checking that is applied
2293	  to 64-bit linear addresses, allowing software to use of the
2294	  untranslated address bits for metadata.
2295
2296	  The capability can be used for efficient address sanitizers (ASAN)
2297	  implementation and for optimizations in JITs.
2298
2299config HOTPLUG_CPU
2300	def_bool y
2301	depends on SMP
2302
2303config COMPAT_VDSO
2304	def_bool n
2305	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2306	depends on COMPAT_32
2307	help
2308	  Certain buggy versions of glibc will crash if they are
2309	  presented with a 32-bit vDSO that is not mapped at the address
2310	  indicated in its segment table.
2311
2312	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2313	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2314	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2315	  the only released version with the bug, but OpenSUSE 9
2316	  contains a buggy "glibc 2.3.2".
2317
2318	  The symptom of the bug is that everything crashes on startup, saying:
2319	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2320
2321	  Saying Y here changes the default value of the vdso32 boot
2322	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2323	  This works around the glibc bug but hurts performance.
2324
2325	  If unsure, say N: if you are compiling your own kernel, you
2326	  are unlikely to be using a buggy version of glibc.
2327
2328choice
2329	prompt "vsyscall table for legacy applications"
2330	depends on X86_64
2331	default LEGACY_VSYSCALL_XONLY
2332	help
2333	  Legacy user code that does not know how to find the vDSO expects
2334	  to be able to issue three syscalls by calling fixed addresses in
2335	  kernel space. Since this location is not randomized with ASLR,
2336	  it can be used to assist security vulnerability exploitation.
2337
2338	  This setting can be changed at boot time via the kernel command
2339	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2340	  is deprecated and can only be enabled using the kernel command
2341	  line.
2342
2343	  On a system with recent enough glibc (2.14 or newer) and no
2344	  static binaries, you can say None without a performance penalty
2345	  to improve security.
2346
2347	  If unsure, select "Emulate execution only".
2348
2349	config LEGACY_VSYSCALL_XONLY
2350		bool "Emulate execution only"
2351		help
2352		  The kernel traps and emulates calls into the fixed vsyscall
2353		  address mapping and does not allow reads.  This
2354		  configuration is recommended when userspace might use the
2355		  legacy vsyscall area but support for legacy binary
2356		  instrumentation of legacy code is not needed.  It mitigates
2357		  certain uses of the vsyscall area as an ASLR-bypassing
2358		  buffer.
2359
2360	config LEGACY_VSYSCALL_NONE
2361		bool "None"
2362		help
2363		  There will be no vsyscall mapping at all. This will
2364		  eliminate any risk of ASLR bypass due to the vsyscall
2365		  fixed address mapping. Attempts to use the vsyscalls
2366		  will be reported to dmesg, so that either old or
2367		  malicious userspace programs can be identified.
2368
2369endchoice
2370
2371config CMDLINE_BOOL
2372	bool "Built-in kernel command line"
2373	help
2374	  Allow for specifying boot arguments to the kernel at
2375	  build time.  On some systems (e.g. embedded ones), it is
2376	  necessary or convenient to provide some or all of the
2377	  kernel boot arguments with the kernel itself (that is,
2378	  to not rely on the boot loader to provide them.)
2379
2380	  To compile command line arguments into the kernel,
2381	  set this option to 'Y', then fill in the
2382	  boot arguments in CONFIG_CMDLINE.
2383
2384	  Systems with fully functional boot loaders (i.e. non-embedded)
2385	  should leave this option set to 'N'.
2386
2387config CMDLINE
2388	string "Built-in kernel command string"
2389	depends on CMDLINE_BOOL
2390	default ""
2391	help
2392	  Enter arguments here that should be compiled into the kernel
2393	  image and used at boot time.  If the boot loader provides a
2394	  command line at boot time, it is appended to this string to
2395	  form the full kernel command line, when the system boots.
2396
2397	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2398	  change this behavior.
2399
2400	  In most cases, the command line (whether built-in or provided
2401	  by the boot loader) should specify the device for the root
2402	  file system.
2403
2404config CMDLINE_OVERRIDE
2405	bool "Built-in command line overrides boot loader arguments"
2406	depends on CMDLINE_BOOL && CMDLINE != ""
2407	help
2408	  Set this option to 'Y' to have the kernel ignore the boot loader
2409	  command line, and use ONLY the built-in command line.
2410
2411	  This is used to work around broken boot loaders.  This should
2412	  be set to 'N' under normal conditions.
2413
2414config MODIFY_LDT_SYSCALL
2415	bool "Enable the LDT (local descriptor table)" if EXPERT
2416	default y
2417	help
2418	  Linux can allow user programs to install a per-process x86
2419	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2420	  call.  This is required to run 16-bit or segmented code such as
2421	  DOSEMU or some Wine programs.  It is also used by some very old
2422	  threading libraries.
2423
2424	  Enabling this feature adds a small amount of overhead to
2425	  context switches and increases the low-level kernel attack
2426	  surface.  Disabling it removes the modify_ldt(2) system call.
2427
2428	  Saying 'N' here may make sense for embedded or server kernels.
2429
2430config STRICT_SIGALTSTACK_SIZE
2431	bool "Enforce strict size checking for sigaltstack"
2432	depends on DYNAMIC_SIGFRAME
2433	help
2434	  For historical reasons MINSIGSTKSZ is a constant which became
2435	  already too small with AVX512 support. Add a mechanism to
2436	  enforce strict checking of the sigaltstack size against the
2437	  real size of the FPU frame. This option enables the check
2438	  by default. It can also be controlled via the kernel command
2439	  line option 'strict_sas_size' independent of this config
2440	  switch. Enabling it might break existing applications which
2441	  allocate a too small sigaltstack but 'work' because they
2442	  never get a signal delivered.
2443
2444	  Say 'N' unless you want to really enforce this check.
2445
2446source "kernel/livepatch/Kconfig"
2447
2448endmenu
2449
2450config CC_HAS_SLS
2451	def_bool $(cc-option,-mharden-sls=all)
2452
2453config CC_HAS_RETURN_THUNK
2454	def_bool $(cc-option,-mfunction-return=thunk-extern)
2455
2456config CC_HAS_ENTRY_PADDING
2457	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2458
2459config FUNCTION_PADDING_CFI
2460	int
2461	default 59 if FUNCTION_ALIGNMENT_64B
2462	default 27 if FUNCTION_ALIGNMENT_32B
2463	default 11 if FUNCTION_ALIGNMENT_16B
2464	default  3 if FUNCTION_ALIGNMENT_8B
2465	default  0
2466
2467# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2468# except Kconfig can't do arithmetic :/
2469config FUNCTION_PADDING_BYTES
2470	int
2471	default FUNCTION_PADDING_CFI if CFI_CLANG
2472	default FUNCTION_ALIGNMENT
2473
2474config CALL_PADDING
2475	def_bool n
2476	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2477	select FUNCTION_ALIGNMENT_16B
2478
2479config FINEIBT
2480	def_bool y
2481	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2482	select CALL_PADDING
2483
2484config HAVE_CALL_THUNKS
2485	def_bool y
2486	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2487
2488config CALL_THUNKS
2489	def_bool n
2490	select CALL_PADDING
2491
2492config PREFIX_SYMBOLS
2493	def_bool y
2494	depends on CALL_PADDING && !CFI_CLANG
2495
2496menuconfig SPECULATION_MITIGATIONS
2497	bool "Mitigations for speculative execution vulnerabilities"
2498	default y
2499	help
2500	  Say Y here to enable options which enable mitigations for
2501	  speculative execution hardware vulnerabilities.
2502
2503	  If you say N, all mitigations will be disabled. You really
2504	  should know what you are doing to say so.
2505
2506if SPECULATION_MITIGATIONS
2507
2508config PAGE_TABLE_ISOLATION
2509	bool "Remove the kernel mapping in user mode"
2510	default y
2511	depends on (X86_64 || X86_PAE)
2512	help
2513	  This feature reduces the number of hardware side channels by
2514	  ensuring that the majority of kernel addresses are not mapped
2515	  into userspace.
2516
2517	  See Documentation/arch/x86/pti.rst for more details.
2518
2519config RETPOLINE
2520	bool "Avoid speculative indirect branches in kernel"
2521	select OBJTOOL if HAVE_OBJTOOL
2522	default y
2523	help
2524	  Compile kernel with the retpoline compiler options to guard against
2525	  kernel-to-user data leaks by avoiding speculative indirect
2526	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2527	  support for full protection. The kernel may run slower.
2528
2529config RETHUNK
2530	bool "Enable return-thunks"
2531	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2532	select OBJTOOL if HAVE_OBJTOOL
2533	default y if X86_64
2534	help
2535	  Compile the kernel with the return-thunks compiler option to guard
2536	  against kernel-to-user data leaks by avoiding return speculation.
2537	  Requires a compiler with -mfunction-return=thunk-extern
2538	  support for full protection. The kernel may run slower.
2539
2540config CPU_UNRET_ENTRY
2541	bool "Enable UNRET on kernel entry"
2542	depends on CPU_SUP_AMD && RETHUNK && X86_64
2543	default y
2544	help
2545	  Compile the kernel with support for the retbleed=unret mitigation.
2546
2547config CALL_DEPTH_TRACKING
2548	bool "Mitigate RSB underflow with call depth tracking"
2549	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2550	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2551	select CALL_THUNKS
2552	default y
2553	help
2554	  Compile the kernel with call depth tracking to mitigate the Intel
2555	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2556	  mitigation is off by default and needs to be enabled on the
2557	  kernel command line via the retbleed=stuff option. For
2558	  non-affected systems the overhead of this option is marginal as
2559	  the call depth tracking is using run-time generated call thunks
2560	  in a compiler generated padding area and call patching. This
2561	  increases text size by ~5%. For non affected systems this space
2562	  is unused. On affected SKL systems this results in a significant
2563	  performance gain over the IBRS mitigation.
2564
2565config CALL_THUNKS_DEBUG
2566	bool "Enable call thunks and call depth tracking debugging"
2567	depends on CALL_DEPTH_TRACKING
2568	select FUNCTION_ALIGNMENT_32B
2569	default n
2570	help
2571	  Enable call/ret counters for imbalance detection and build in
2572	  a noisy dmesg about callthunks generation and call patching for
2573	  trouble shooting. The debug prints need to be enabled on the
2574	  kernel command line with 'debug-callthunks'.
2575	  Only enable this when you are debugging call thunks as this
2576	  creates a noticeable runtime overhead. If unsure say N.
2577
2578config CPU_IBPB_ENTRY
2579	bool "Enable IBPB on kernel entry"
2580	depends on CPU_SUP_AMD && X86_64
2581	default y
2582	help
2583	  Compile the kernel with support for the retbleed=ibpb mitigation.
2584
2585config CPU_IBRS_ENTRY
2586	bool "Enable IBRS on kernel entry"
2587	depends on CPU_SUP_INTEL && X86_64
2588	default y
2589	help
2590	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2591	  This mitigates both spectre_v2 and retbleed at great cost to
2592	  performance.
2593
2594config SLS
2595	bool "Mitigate Straight-Line-Speculation"
2596	depends on CC_HAS_SLS && X86_64
2597	select OBJTOOL if HAVE_OBJTOOL
2598	default n
2599	help
2600	  Compile the kernel with straight-line-speculation options to guard
2601	  against straight line speculation. The kernel image might be slightly
2602	  larger.
2603
2604endif
2605
2606config ARCH_HAS_ADD_PAGES
2607	def_bool y
2608	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2609
2610config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2611	def_bool y
2612
2613menu "Power management and ACPI options"
2614
2615config ARCH_HIBERNATION_HEADER
2616	def_bool y
2617	depends on HIBERNATION
2618
2619source "kernel/power/Kconfig"
2620
2621source "drivers/acpi/Kconfig"
2622
2623config X86_APM_BOOT
2624	def_bool y
2625	depends on APM
2626
2627menuconfig APM
2628	tristate "APM (Advanced Power Management) BIOS support"
2629	depends on X86_32 && PM_SLEEP
2630	help
2631	  APM is a BIOS specification for saving power using several different
2632	  techniques. This is mostly useful for battery powered laptops with
2633	  APM compliant BIOSes. If you say Y here, the system time will be
2634	  reset after a RESUME operation, the /proc/apm device will provide
2635	  battery status information, and user-space programs will receive
2636	  notification of APM "events" (e.g. battery status change).
2637
2638	  If you select "Y" here, you can disable actual use of the APM
2639	  BIOS by passing the "apm=off" option to the kernel at boot time.
2640
2641	  Note that the APM support is almost completely disabled for
2642	  machines with more than one CPU.
2643
2644	  In order to use APM, you will need supporting software. For location
2645	  and more information, read <file:Documentation/power/apm-acpi.rst>
2646	  and the Battery Powered Linux mini-HOWTO, available from
2647	  <http://www.tldp.org/docs.html#howto>.
2648
2649	  This driver does not spin down disk drives (see the hdparm(8)
2650	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2651	  VESA-compliant "green" monitors.
2652
2653	  This driver does not support the TI 4000M TravelMate and the ACER
2654	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2655	  desktop machines also don't have compliant BIOSes, and this driver
2656	  may cause those machines to panic during the boot phase.
2657
2658	  Generally, if you don't have a battery in your machine, there isn't
2659	  much point in using this driver and you should say N. If you get
2660	  random kernel OOPSes or reboots that don't seem to be related to
2661	  anything, try disabling/enabling this option (or disabling/enabling
2662	  APM in your BIOS).
2663
2664	  Some other things you should try when experiencing seemingly random,
2665	  "weird" problems:
2666
2667	  1) make sure that you have enough swap space and that it is
2668	  enabled.
2669	  2) pass the "idle=poll" option to the kernel
2670	  3) switch on floating point emulation in the kernel and pass
2671	  the "no387" option to the kernel
2672	  4) pass the "floppy=nodma" option to the kernel
2673	  5) pass the "mem=4M" option to the kernel (thereby disabling
2674	  all but the first 4 MB of RAM)
2675	  6) make sure that the CPU is not over clocked.
2676	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2677	  8) disable the cache from your BIOS settings
2678	  9) install a fan for the video card or exchange video RAM
2679	  10) install a better fan for the CPU
2680	  11) exchange RAM chips
2681	  12) exchange the motherboard.
2682
2683	  To compile this driver as a module, choose M here: the
2684	  module will be called apm.
2685
2686if APM
2687
2688config APM_IGNORE_USER_SUSPEND
2689	bool "Ignore USER SUSPEND"
2690	help
2691	  This option will ignore USER SUSPEND requests. On machines with a
2692	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2693	  series notebooks, it is necessary to say Y because of a BIOS bug.
2694
2695config APM_DO_ENABLE
2696	bool "Enable PM at boot time"
2697	help
2698	  Enable APM features at boot time. From page 36 of the APM BIOS
2699	  specification: "When disabled, the APM BIOS does not automatically
2700	  power manage devices, enter the Standby State, enter the Suspend
2701	  State, or take power saving steps in response to CPU Idle calls."
2702	  This driver will make CPU Idle calls when Linux is idle (unless this
2703	  feature is turned off -- see "Do CPU IDLE calls", below). This
2704	  should always save battery power, but more complicated APM features
2705	  will be dependent on your BIOS implementation. You may need to turn
2706	  this option off if your computer hangs at boot time when using APM
2707	  support, or if it beeps continuously instead of suspending. Turn
2708	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2709	  T400CDT. This is off by default since most machines do fine without
2710	  this feature.
2711
2712config APM_CPU_IDLE
2713	depends on CPU_IDLE
2714	bool "Make CPU Idle calls when idle"
2715	help
2716	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2717	  On some machines, this can activate improved power savings, such as
2718	  a slowed CPU clock rate, when the machine is idle. These idle calls
2719	  are made after the idle loop has run for some length of time (e.g.,
2720	  333 mS). On some machines, this will cause a hang at boot time or
2721	  whenever the CPU becomes idle. (On machines with more than one CPU,
2722	  this option does nothing.)
2723
2724config APM_DISPLAY_BLANK
2725	bool "Enable console blanking using APM"
2726	help
2727	  Enable console blanking using the APM. Some laptops can use this to
2728	  turn off the LCD backlight when the screen blanker of the Linux
2729	  virtual console blanks the screen. Note that this is only used by
2730	  the virtual console screen blanker, and won't turn off the backlight
2731	  when using the X Window system. This also doesn't have anything to
2732	  do with your VESA-compliant power-saving monitor. Further, this
2733	  option doesn't work for all laptops -- it might not turn off your
2734	  backlight at all, or it might print a lot of errors to the console,
2735	  especially if you are using gpm.
2736
2737config APM_ALLOW_INTS
2738	bool "Allow interrupts during APM BIOS calls"
2739	help
2740	  Normally we disable external interrupts while we are making calls to
2741	  the APM BIOS as a measure to lessen the effects of a badly behaving
2742	  BIOS implementation.  The BIOS should reenable interrupts if it
2743	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2744	  many of the newer IBM Thinkpads.  If you experience hangs when you
2745	  suspend, try setting this to Y.  Otherwise, say N.
2746
2747endif # APM
2748
2749source "drivers/cpufreq/Kconfig"
2750
2751source "drivers/cpuidle/Kconfig"
2752
2753source "drivers/idle/Kconfig"
2754
2755endmenu
2756
2757menu "Bus options (PCI etc.)"
2758
2759choice
2760	prompt "PCI access mode"
2761	depends on X86_32 && PCI
2762	default PCI_GOANY
2763	help
2764	  On PCI systems, the BIOS can be used to detect the PCI devices and
2765	  determine their configuration. However, some old PCI motherboards
2766	  have BIOS bugs and may crash if this is done. Also, some embedded
2767	  PCI-based systems don't have any BIOS at all. Linux can also try to
2768	  detect the PCI hardware directly without using the BIOS.
2769
2770	  With this option, you can specify how Linux should detect the
2771	  PCI devices. If you choose "BIOS", the BIOS will be used,
2772	  if you choose "Direct", the BIOS won't be used, and if you
2773	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2774	  If you choose "Any", the kernel will try MMCONFIG, then the
2775	  direct access method and falls back to the BIOS if that doesn't
2776	  work. If unsure, go with the default, which is "Any".
2777
2778config PCI_GOBIOS
2779	bool "BIOS"
2780
2781config PCI_GOMMCONFIG
2782	bool "MMConfig"
2783
2784config PCI_GODIRECT
2785	bool "Direct"
2786
2787config PCI_GOOLPC
2788	bool "OLPC XO-1"
2789	depends on OLPC
2790
2791config PCI_GOANY
2792	bool "Any"
2793
2794endchoice
2795
2796config PCI_BIOS
2797	def_bool y
2798	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2799
2800# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2801config PCI_DIRECT
2802	def_bool y
2803	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2804
2805config PCI_MMCONFIG
2806	bool "Support mmconfig PCI config space access" if X86_64
2807	default y
2808	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2809	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2810
2811config PCI_OLPC
2812	def_bool y
2813	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2814
2815config PCI_XEN
2816	def_bool y
2817	depends on PCI && XEN
2818
2819config MMCONF_FAM10H
2820	def_bool y
2821	depends on X86_64 && PCI_MMCONFIG && ACPI
2822
2823config PCI_CNB20LE_QUIRK
2824	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2825	depends on PCI
2826	help
2827	  Read the PCI windows out of the CNB20LE host bridge. This allows
2828	  PCI hotplug to work on systems with the CNB20LE chipset which do
2829	  not have ACPI.
2830
2831	  There's no public spec for this chipset, and this functionality
2832	  is known to be incomplete.
2833
2834	  You should say N unless you know you need this.
2835
2836config ISA_BUS
2837	bool "ISA bus support on modern systems" if EXPERT
2838	help
2839	  Expose ISA bus device drivers and options available for selection and
2840	  configuration. Enable this option if your target machine has an ISA
2841	  bus. ISA is an older system, displaced by PCI and newer bus
2842	  architectures -- if your target machine is modern, it probably does
2843	  not have an ISA bus.
2844
2845	  If unsure, say N.
2846
2847# x86_64 have no ISA slots, but can have ISA-style DMA.
2848config ISA_DMA_API
2849	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2850	default y
2851	help
2852	  Enables ISA-style DMA support for devices requiring such controllers.
2853	  If unsure, say Y.
2854
2855if X86_32
2856
2857config ISA
2858	bool "ISA support"
2859	help
2860	  Find out whether you have ISA slots on your motherboard.  ISA is the
2861	  name of a bus system, i.e. the way the CPU talks to the other stuff
2862	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2863	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2864	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2865
2866config SCx200
2867	tristate "NatSemi SCx200 support"
2868	help
2869	  This provides basic support for National Semiconductor's
2870	  (now AMD's) Geode processors.  The driver probes for the
2871	  PCI-IDs of several on-chip devices, so its a good dependency
2872	  for other scx200_* drivers.
2873
2874	  If compiled as a module, the driver is named scx200.
2875
2876config SCx200HR_TIMER
2877	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2878	depends on SCx200
2879	default y
2880	help
2881	  This driver provides a clocksource built upon the on-chip
2882	  27MHz high-resolution timer.  Its also a workaround for
2883	  NSC Geode SC-1100's buggy TSC, which loses time when the
2884	  processor goes idle (as is done by the scheduler).  The
2885	  other workaround is idle=poll boot option.
2886
2887config OLPC
2888	bool "One Laptop Per Child support"
2889	depends on !X86_PAE
2890	select GPIOLIB
2891	select OF
2892	select OF_PROMTREE
2893	select IRQ_DOMAIN
2894	select OLPC_EC
2895	help
2896	  Add support for detecting the unique features of the OLPC
2897	  XO hardware.
2898
2899config OLPC_XO1_PM
2900	bool "OLPC XO-1 Power Management"
2901	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2902	help
2903	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2904
2905config OLPC_XO1_RTC
2906	bool "OLPC XO-1 Real Time Clock"
2907	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2908	help
2909	  Add support for the XO-1 real time clock, which can be used as a
2910	  programmable wakeup source.
2911
2912config OLPC_XO1_SCI
2913	bool "OLPC XO-1 SCI extras"
2914	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2915	depends on INPUT=y
2916	select POWER_SUPPLY
2917	help
2918	  Add support for SCI-based features of the OLPC XO-1 laptop:
2919	   - EC-driven system wakeups
2920	   - Power button
2921	   - Ebook switch
2922	   - Lid switch
2923	   - AC adapter status updates
2924	   - Battery status updates
2925
2926config OLPC_XO15_SCI
2927	bool "OLPC XO-1.5 SCI extras"
2928	depends on OLPC && ACPI
2929	select POWER_SUPPLY
2930	help
2931	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2932	   - EC-driven system wakeups
2933	   - AC adapter status updates
2934	   - Battery status updates
2935
2936config ALIX
2937	bool "PCEngines ALIX System Support (LED setup)"
2938	select GPIOLIB
2939	help
2940	  This option enables system support for the PCEngines ALIX.
2941	  At present this just sets up LEDs for GPIO control on
2942	  ALIX2/3/6 boards.  However, other system specific setup should
2943	  get added here.
2944
2945	  Note: You must still enable the drivers for GPIO and LED support
2946	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2947
2948	  Note: You have to set alix.force=1 for boards with Award BIOS.
2949
2950config NET5501
2951	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2952	select GPIOLIB
2953	help
2954	  This option enables system support for the Soekris Engineering net5501.
2955
2956config GEOS
2957	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2958	select GPIOLIB
2959	depends on DMI
2960	help
2961	  This option enables system support for the Traverse Technologies GEOS.
2962
2963config TS5500
2964	bool "Technologic Systems TS-5500 platform support"
2965	depends on MELAN
2966	select CHECK_SIGNATURE
2967	select NEW_LEDS
2968	select LEDS_CLASS
2969	help
2970	  This option enables system support for the Technologic Systems TS-5500.
2971
2972endif # X86_32
2973
2974config AMD_NB
2975	def_bool y
2976	depends on CPU_SUP_AMD && PCI
2977
2978endmenu
2979
2980menu "Binary Emulations"
2981
2982config IA32_EMULATION
2983	bool "IA32 Emulation"
2984	depends on X86_64
2985	select ARCH_WANT_OLD_COMPAT_IPC
2986	select BINFMT_ELF
2987	select COMPAT_OLD_SIGACTION
2988	help
2989	  Include code to run legacy 32-bit programs under a
2990	  64-bit kernel. You should likely turn this on, unless you're
2991	  100% sure that you don't have any 32-bit programs left.
2992
2993config X86_X32_ABI
2994	bool "x32 ABI for 64-bit mode"
2995	depends on X86_64
2996	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2997	# compressed debug sections to x86_x32 properly:
2998	# https://github.com/ClangBuiltLinux/linux/issues/514
2999	# https://github.com/ClangBuiltLinux/linux/issues/1141
3000	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3001	help
3002	  Include code to run binaries for the x32 native 32-bit ABI
3003	  for 64-bit processors.  An x32 process gets access to the
3004	  full 64-bit register file and wide data path while leaving
3005	  pointers at 32 bits for smaller memory footprint.
3006
3007config COMPAT_32
3008	def_bool y
3009	depends on IA32_EMULATION || X86_32
3010	select HAVE_UID16
3011	select OLD_SIGSUSPEND3
3012
3013config COMPAT
3014	def_bool y
3015	depends on IA32_EMULATION || X86_X32_ABI
3016
3017config COMPAT_FOR_U64_ALIGNMENT
3018	def_bool y
3019	depends on COMPAT
3020
3021endmenu
3022
3023config HAVE_ATOMIC_IOMAP
3024	def_bool y
3025	depends on X86_32
3026
3027source "arch/x86/kvm/Kconfig"
3028
3029source "arch/x86/Kconfig.assembler"
3030