xref: /linux/arch/x86/Kconfig (revision 61307b7be41a1f1039d1d1368810a1d92cb97b44)
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 HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37	select EXECMEM if DYNAMIC_FTRACE
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 ACPI_HOTPLUG_CPU			if ACPI_PROCESSOR && HOTPLUG_CPU
64	select ARCH_32BIT_OFF_T			if X86_32
65	select ARCH_CLOCKSOURCE_INIT
66	select ARCH_CONFIGURES_CPU_MITIGATIONS
67	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
68	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
69	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
70	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
71	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
72	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
73	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
74	select ARCH_HAS_CACHE_LINE_SIZE
75	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
76	select ARCH_HAS_CPU_FINALIZE_INIT
77	select ARCH_HAS_CPU_PASID		if IOMMU_SVA
78	select ARCH_HAS_CURRENT_STACK_POINTER
79	select ARCH_HAS_DEBUG_VIRTUAL
80	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
81	select ARCH_HAS_DEVMEM_IS_ALLOWED
82	select ARCH_HAS_EARLY_DEBUG		if KGDB
83	select ARCH_HAS_ELF_RANDOMIZE
84	select ARCH_HAS_FAST_MULTIPLIER
85	select ARCH_HAS_FORTIFY_SOURCE
86	select ARCH_HAS_GCOV_PROFILE_ALL
87	select ARCH_HAS_KCOV			if X86_64
88	select ARCH_HAS_MEM_ENCRYPT
89	select ARCH_HAS_MEMBARRIER_SYNC_CORE
90	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
91	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
92	select ARCH_HAS_PMEM_API		if X86_64
93	select ARCH_HAS_PTE_DEVMAP		if X86_64
94	select ARCH_HAS_PTE_SPECIAL
95	select ARCH_HAS_HW_PTE_YOUNG
96	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
97	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
98	select ARCH_HAS_COPY_MC			if X86_64
99	select ARCH_HAS_SET_MEMORY
100	select ARCH_HAS_SET_DIRECT_MAP
101	select ARCH_HAS_STRICT_KERNEL_RWX
102	select ARCH_HAS_STRICT_MODULE_RWX
103	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
104	select ARCH_HAS_SYSCALL_WRAPPER
105	select ARCH_HAS_UBSAN
106	select ARCH_HAS_DEBUG_WX
107	select ARCH_HAS_ZONE_DMA_SET if EXPERT
108	select ARCH_HAVE_NMI_SAFE_CMPXCHG
109	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
110	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
111	select ARCH_MIGHT_HAVE_PC_PARPORT
112	select ARCH_MIGHT_HAVE_PC_SERIO
113	select ARCH_STACKWALK
114	select ARCH_SUPPORTS_ACPI
115	select ARCH_SUPPORTS_ATOMIC_RMW
116	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
117	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
118	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
119	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
120	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
121	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
122	select ARCH_SUPPORTS_LTO_CLANG
123	select ARCH_SUPPORTS_LTO_CLANG_THIN
124	select ARCH_USE_BUILTIN_BSWAP
125	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
126	select ARCH_USE_MEMTEST
127	select ARCH_USE_QUEUED_RWLOCKS
128	select ARCH_USE_QUEUED_SPINLOCKS
129	select ARCH_USE_SYM_ANNOTATIONS
130	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
131	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
132	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
133	select ARCH_WANTS_NO_INSTR
134	select ARCH_WANT_GENERAL_HUGETLB
135	select ARCH_WANT_HUGE_PMD_SHARE
136	select ARCH_WANT_LD_ORPHAN_WARN
137	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
138	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
139	select ARCH_WANTS_THP_SWAP		if X86_64
140	select ARCH_HAS_PARANOID_L1D_FLUSH
141	select BUILDTIME_TABLE_SORT
142	select CLKEVT_I8253
143	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
144	select CLOCKSOURCE_WATCHDOG
145	# Word-size accesses may read uninitialized data past the trailing \0
146	# in strings and cause false KMSAN reports.
147	select DCACHE_WORD_ACCESS		if !KMSAN
148	select DYNAMIC_SIGFRAME
149	select EDAC_ATOMIC_SCRUB
150	select EDAC_SUPPORT
151	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
152	select GENERIC_CLOCKEVENTS_BROADCAST_IDLE	if GENERIC_CLOCKEVENTS_BROADCAST
153	select GENERIC_CLOCKEVENTS_MIN_ADJUST
154	select GENERIC_CMOS_UPDATE
155	select GENERIC_CPU_AUTOPROBE
156	select GENERIC_CPU_DEVICES
157	select GENERIC_CPU_VULNERABILITIES
158	select GENERIC_EARLY_IOREMAP
159	select GENERIC_ENTRY
160	select GENERIC_IOMAP
161	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
162	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
163	select GENERIC_IRQ_MIGRATION		if SMP
164	select GENERIC_IRQ_PROBE
165	select GENERIC_IRQ_RESERVATION_MODE
166	select GENERIC_IRQ_SHOW
167	select GENERIC_PENDING_IRQ		if SMP
168	select GENERIC_PTDUMP
169	select GENERIC_SMP_IDLE_THREAD
170	select GENERIC_TIME_VSYSCALL
171	select GENERIC_GETTIMEOFDAY
172	select GENERIC_VDSO_TIME_NS
173	select GENERIC_VDSO_OVERFLOW_PROTECT
174	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
175	select HARDIRQS_SW_RESEND
176	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
177	select HAS_IOPORT
178	select HAVE_ACPI_APEI			if ACPI
179	select HAVE_ACPI_APEI_NMI		if ACPI
180	select HAVE_ALIGNED_STRUCT_PAGE
181	select HAVE_ARCH_AUDITSYSCALL
182	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
183	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
184	select HAVE_ARCH_JUMP_LABEL
185	select HAVE_ARCH_JUMP_LABEL_RELATIVE
186	select HAVE_ARCH_KASAN			if X86_64
187	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
188	select HAVE_ARCH_KFENCE
189	select HAVE_ARCH_KMSAN			if X86_64
190	select HAVE_ARCH_KGDB
191	select HAVE_ARCH_MMAP_RND_BITS		if MMU
192	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
193	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
194	select HAVE_ARCH_PREL32_RELOCATIONS
195	select HAVE_ARCH_SECCOMP_FILTER
196	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
197	select HAVE_ARCH_STACKLEAK
198	select HAVE_ARCH_TRACEHOOK
199	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
200	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
201	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
202	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
203	select HAVE_ARCH_VMAP_STACK		if X86_64
204	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
205	select HAVE_ARCH_WITHIN_STACK_FRAMES
206	select HAVE_ASM_MODVERSIONS
207	select HAVE_CMPXCHG_DOUBLE
208	select HAVE_CMPXCHG_LOCAL
209	select HAVE_CONTEXT_TRACKING_USER		if X86_64
210	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
211	select HAVE_C_RECORDMCOUNT
212	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
213	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
214	select HAVE_BUILDTIME_MCOUNT_SORT
215	select HAVE_DEBUG_KMEMLEAK
216	select HAVE_DMA_CONTIGUOUS
217	select HAVE_DYNAMIC_FTRACE
218	select HAVE_DYNAMIC_FTRACE_WITH_REGS
219	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
220	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
221	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
222	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
223	select HAVE_EBPF_JIT
224	select HAVE_EFFICIENT_UNALIGNED_ACCESS
225	select HAVE_EISA
226	select HAVE_EXIT_THREAD
227	select HAVE_GUP_FAST
228	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
229	select HAVE_FTRACE_MCOUNT_RECORD
230	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
231	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
232	select HAVE_FUNCTION_TRACER
233	select HAVE_GCC_PLUGINS
234	select HAVE_HW_BREAKPOINT
235	select HAVE_IOREMAP_PROT
236	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
237	select HAVE_IRQ_TIME_ACCOUNTING
238	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
239	select HAVE_KERNEL_BZIP2
240	select HAVE_KERNEL_GZIP
241	select HAVE_KERNEL_LZ4
242	select HAVE_KERNEL_LZMA
243	select HAVE_KERNEL_LZO
244	select HAVE_KERNEL_XZ
245	select HAVE_KERNEL_ZSTD
246	select HAVE_KPROBES
247	select HAVE_KPROBES_ON_FTRACE
248	select HAVE_FUNCTION_ERROR_INJECTION
249	select HAVE_KRETPROBES
250	select HAVE_RETHOOK
251	select HAVE_LIVEPATCH			if X86_64
252	select HAVE_MIXED_BREAKPOINTS_REGS
253	select HAVE_MOD_ARCH_SPECIFIC
254	select HAVE_MOVE_PMD
255	select HAVE_MOVE_PUD
256	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
257	select HAVE_NMI
258	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
259	select HAVE_OBJTOOL			if X86_64
260	select HAVE_OPTPROBES
261	select HAVE_PAGE_SIZE_4KB
262	select HAVE_PCSPKR_PLATFORM
263	select HAVE_PERF_EVENTS
264	select HAVE_PERF_EVENTS_NMI
265	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
266	select HAVE_PCI
267	select HAVE_PERF_REGS
268	select HAVE_PERF_USER_STACK_DUMP
269	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
270	select MMU_GATHER_MERGE_VMAS
271	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
272	select HAVE_REGS_AND_STACK_ACCESS_API
273	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
274	select HAVE_FUNCTION_ARG_ACCESS_API
275	select HAVE_SETUP_PER_CPU_AREA
276	select HAVE_SOFTIRQ_ON_OWN_STACK
277	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
278	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
279	select HAVE_STATIC_CALL
280	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
281	select HAVE_PREEMPT_DYNAMIC_CALL
282	select HAVE_RSEQ
283	select HAVE_RUST			if X86_64
284	select HAVE_SYSCALL_TRACEPOINTS
285	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
286	select HAVE_UNSTABLE_SCHED_CLOCK
287	select HAVE_USER_RETURN_NOTIFIER
288	select HAVE_GENERIC_VDSO
289	select HOTPLUG_PARALLEL			if SMP && X86_64
290	select HOTPLUG_SMT			if SMP
291	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
292	select IRQ_FORCED_THREADING
293	select LOCK_MM_AND_FIND_VMA
294	select NEED_PER_CPU_EMBED_FIRST_CHUNK
295	select NEED_PER_CPU_PAGE_FIRST_CHUNK
296	select NEED_SG_DMA_LENGTH
297	select PCI_DOMAINS			if PCI
298	select PCI_LOCKLESS_CONFIG		if PCI
299	select PERF_EVENTS
300	select RTC_LIB
301	select RTC_MC146818_LIB
302	select SPARSE_IRQ
303	select SYSCTL_EXCEPTION_TRACE
304	select THREAD_INFO_IN_TASK
305	select TRACE_IRQFLAGS_SUPPORT
306	select TRACE_IRQFLAGS_NMI_SUPPORT
307	select USER_STACKTRACE_SUPPORT
308	select HAVE_ARCH_KCSAN			if X86_64
309	select PROC_PID_ARCH_STATUS		if PROC_FS
310	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
311	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
312	select FUNCTION_ALIGNMENT_4B
313	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
314	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
315
316config INSTRUCTION_DECODER
317	def_bool y
318	depends on KPROBES || PERF_EVENTS || UPROBES
319
320config OUTPUT_FORMAT
321	string
322	default "elf32-i386" if X86_32
323	default "elf64-x86-64" if X86_64
324
325config LOCKDEP_SUPPORT
326	def_bool y
327
328config STACKTRACE_SUPPORT
329	def_bool y
330
331config MMU
332	def_bool y
333
334config ARCH_MMAP_RND_BITS_MIN
335	default 28 if 64BIT
336	default 8
337
338config ARCH_MMAP_RND_BITS_MAX
339	default 32 if 64BIT
340	default 16
341
342config ARCH_MMAP_RND_COMPAT_BITS_MIN
343	default 8
344
345config ARCH_MMAP_RND_COMPAT_BITS_MAX
346	default 16
347
348config SBUS
349	bool
350
351config GENERIC_ISA_DMA
352	def_bool y
353	depends on ISA_DMA_API
354
355config GENERIC_CSUM
356	bool
357	default y if KMSAN || KASAN
358
359config GENERIC_BUG
360	def_bool y
361	depends on BUG
362	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
363
364config GENERIC_BUG_RELATIVE_POINTERS
365	bool
366
367config ARCH_MAY_HAVE_PC_FDC
368	def_bool y
369	depends on ISA_DMA_API
370
371config GENERIC_CALIBRATE_DELAY
372	def_bool y
373
374config ARCH_HAS_CPU_RELAX
375	def_bool y
376
377config ARCH_HIBERNATION_POSSIBLE
378	def_bool y
379
380config ARCH_SUSPEND_POSSIBLE
381	def_bool y
382
383config AUDIT_ARCH
384	def_bool y if X86_64
385
386config KASAN_SHADOW_OFFSET
387	hex
388	depends on KASAN
389	default 0xdffffc0000000000
390
391config HAVE_INTEL_TXT
392	def_bool y
393	depends on INTEL_IOMMU && ACPI
394
395config X86_64_SMP
396	def_bool y
397	depends on X86_64 && SMP
398
399config ARCH_SUPPORTS_UPROBES
400	def_bool y
401
402config FIX_EARLYCON_MEM
403	def_bool y
404
405config DYNAMIC_PHYSICAL_MASK
406	bool
407
408config PGTABLE_LEVELS
409	int
410	default 5 if X86_5LEVEL
411	default 4 if X86_64
412	default 3 if X86_PAE
413	default 2
414
415config CC_HAS_SANE_STACKPROTECTOR
416	bool
417	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
418	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
419	help
420	  We have to make sure stack protector is unconditionally disabled if
421	  the compiler produces broken code or if it does not let us control
422	  the segment on 32-bit kernels.
423
424menu "Processor type and features"
425
426config SMP
427	bool "Symmetric multi-processing support"
428	help
429	  This enables support for systems with more than one CPU. If you have
430	  a system with only one CPU, say N. If you have a system with more
431	  than one CPU, say Y.
432
433	  If you say N here, the kernel will run on uni- and multiprocessor
434	  machines, but will use only one CPU of a multiprocessor machine. If
435	  you say Y here, the kernel will run on many, but not all,
436	  uniprocessor machines. On a uniprocessor machine, the kernel
437	  will run faster if you say N here.
438
439	  Note that if you say Y here and choose architecture "586" or
440	  "Pentium" under "Processor family", the kernel will not work on 486
441	  architectures. Similarly, multiprocessor kernels for the "PPro"
442	  architecture may not work on all Pentium based boards.
443
444	  People using multiprocessor machines who say Y here should also say
445	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
446	  Management" code will be disabled if you say Y here.
447
448	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
449	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
450	  <http://www.tldp.org/docs.html#howto>.
451
452	  If you don't know what to do here, say N.
453
454config X86_X2APIC
455	bool "Support x2apic"
456	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
457	help
458	  This enables x2apic support on CPUs that have this feature.
459
460	  This allows 32-bit apic IDs (so it can support very large systems),
461	  and accesses the local apic via MSRs not via mmio.
462
463	  Some Intel systems circa 2022 and later are locked into x2APIC mode
464	  and can not fall back to the legacy APIC modes if SGX or TDX are
465	  enabled in the BIOS. They will boot with very reduced functionality
466	  without enabling this option.
467
468	  If you don't know what to do here, say N.
469
470config X86_POSTED_MSI
471	bool "Enable MSI and MSI-x delivery by posted interrupts"
472	depends on X86_64 && IRQ_REMAP
473	help
474	  This enables MSIs that are under interrupt remapping to be delivered as
475	  posted interrupts to the host kernel. Interrupt throughput can
476	  potentially be improved by coalescing CPU notifications during high
477	  frequency bursts.
478
479	  If you don't know what to do here, say N.
480
481config X86_MPPARSE
482	bool "Enable MPS table" if ACPI
483	default y
484	depends on X86_LOCAL_APIC
485	help
486	  For old smp systems that do not have proper acpi support. Newer systems
487	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
488
489config X86_CPU_RESCTRL
490	bool "x86 CPU resource control support"
491	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
492	select KERNFS
493	select PROC_CPU_RESCTRL		if PROC_FS
494	help
495	  Enable x86 CPU resource control support.
496
497	  Provide support for the allocation and monitoring of system resources
498	  usage by the CPU.
499
500	  Intel calls this Intel Resource Director Technology
501	  (Intel(R) RDT). More information about RDT can be found in the
502	  Intel x86 Architecture Software Developer Manual.
503
504	  AMD calls this AMD Platform Quality of Service (AMD QoS).
505	  More information about AMD QoS can be found in the AMD64 Technology
506	  Platform Quality of Service Extensions manual.
507
508	  Say N if unsure.
509
510config X86_FRED
511	bool "Flexible Return and Event Delivery"
512	depends on X86_64
513	help
514	  When enabled, try to use Flexible Return and Event Delivery
515	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
516	  ring transitions and exception/interrupt handling if the
517	  system supports it.
518
519config X86_BIGSMP
520	bool "Support for big SMP systems with more than 8 CPUs"
521	depends on SMP && X86_32
522	help
523	  This option is needed for the systems that have more than 8 CPUs.
524
525config X86_EXTENDED_PLATFORM
526	bool "Support for extended (non-PC) x86 platforms"
527	default y
528	help
529	  If you disable this option then the kernel will only support
530	  standard PC platforms. (which covers the vast majority of
531	  systems out there.)
532
533	  If you enable this option then you'll be able to select support
534	  for the following non-PC x86 platforms, depending on the value of
535	  CONFIG_64BIT.
536
537	  32-bit platforms (CONFIG_64BIT=n):
538		Goldfish (Android emulator)
539		AMD Elan
540		RDC R-321x SoC
541		SGI 320/540 (Visual Workstation)
542		STA2X11-based (e.g. Northville)
543		Moorestown MID devices
544
545	  64-bit platforms (CONFIG_64BIT=y):
546		Numascale NumaChip
547		ScaleMP vSMP
548		SGI Ultraviolet
549
550	  If you have one of these systems, or if you want to build a
551	  generic distribution kernel, say Y here - otherwise say N.
552
553# This is an alphabetically sorted list of 64 bit extended platforms
554# Please maintain the alphabetic order if and when there are additions
555config X86_NUMACHIP
556	bool "Numascale NumaChip"
557	depends on X86_64
558	depends on X86_EXTENDED_PLATFORM
559	depends on NUMA
560	depends on SMP
561	depends on X86_X2APIC
562	depends on PCI_MMCONFIG
563	help
564	  Adds support for Numascale NumaChip large-SMP systems. Needed to
565	  enable more than ~168 cores.
566	  If you don't have one of these, you should say N here.
567
568config X86_VSMP
569	bool "ScaleMP vSMP"
570	select HYPERVISOR_GUEST
571	select PARAVIRT
572	depends on X86_64 && PCI
573	depends on X86_EXTENDED_PLATFORM
574	depends on SMP
575	help
576	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
577	  supposed to run on these EM64T-based machines.  Only choose this option
578	  if you have one of these machines.
579
580config X86_UV
581	bool "SGI Ultraviolet"
582	depends on X86_64
583	depends on X86_EXTENDED_PLATFORM
584	depends on NUMA
585	depends on EFI
586	depends on KEXEC_CORE
587	depends on X86_X2APIC
588	depends on PCI
589	help
590	  This option is needed in order to support SGI Ultraviolet systems.
591	  If you don't have one of these, you should say N here.
592
593# Following is an alphabetically sorted list of 32 bit extended platforms
594# Please maintain the alphabetic order if and when there are additions
595
596config X86_GOLDFISH
597	bool "Goldfish (Virtual Platform)"
598	depends on X86_EXTENDED_PLATFORM
599	help
600	  Enable support for the Goldfish virtual platform used primarily
601	  for Android development. Unless you are building for the Android
602	  Goldfish emulator say N here.
603
604config X86_INTEL_CE
605	bool "CE4100 TV platform"
606	depends on PCI
607	depends on PCI_GODIRECT
608	depends on X86_IO_APIC
609	depends on X86_32
610	depends on X86_EXTENDED_PLATFORM
611	select X86_REBOOTFIXUPS
612	select OF
613	select OF_EARLY_FLATTREE
614	help
615	  Select for the Intel CE media processor (CE4100) SOC.
616	  This option compiles in support for the CE4100 SOC for settop
617	  boxes and media devices.
618
619config X86_INTEL_MID
620	bool "Intel MID platform support"
621	depends on X86_EXTENDED_PLATFORM
622	depends on X86_PLATFORM_DEVICES
623	depends on PCI
624	depends on X86_64 || (PCI_GOANY && X86_32)
625	depends on X86_IO_APIC
626	select I2C
627	select DW_APB_TIMER
628	select INTEL_SCU_PCI
629	help
630	  Select to build a kernel capable of supporting Intel MID (Mobile
631	  Internet Device) platform systems which do not have the PCI legacy
632	  interfaces. If you are building for a PC class system say N here.
633
634	  Intel MID platforms are based on an Intel processor and chipset which
635	  consume less power than most of the x86 derivatives.
636
637config X86_INTEL_QUARK
638	bool "Intel Quark platform support"
639	depends on X86_32
640	depends on X86_EXTENDED_PLATFORM
641	depends on X86_PLATFORM_DEVICES
642	depends on X86_TSC
643	depends on PCI
644	depends on PCI_GOANY
645	depends on X86_IO_APIC
646	select IOSF_MBI
647	select INTEL_IMR
648	select COMMON_CLK
649	help
650	  Select to include support for Quark X1000 SoC.
651	  Say Y here if you have a Quark based system such as the Arduino
652	  compatible Intel Galileo.
653
654config X86_INTEL_LPSS
655	bool "Intel Low Power Subsystem Support"
656	depends on X86 && ACPI && PCI
657	select COMMON_CLK
658	select PINCTRL
659	select IOSF_MBI
660	help
661	  Select to build support for Intel Low Power Subsystem such as
662	  found on Intel Lynxpoint PCH. Selecting this option enables
663	  things like clock tree (common clock framework) and pincontrol
664	  which are needed by the LPSS peripheral drivers.
665
666config X86_AMD_PLATFORM_DEVICE
667	bool "AMD ACPI2Platform devices support"
668	depends on ACPI
669	select COMMON_CLK
670	select PINCTRL
671	help
672	  Select to interpret AMD specific ACPI device to platform device
673	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
674	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
675	  implemented under PINCTRL subsystem.
676
677config IOSF_MBI
678	tristate "Intel SoC IOSF Sideband support for SoC platforms"
679	depends on PCI
680	help
681	  This option enables sideband register access support for Intel SoC
682	  platforms. On these platforms the IOSF sideband is used in lieu of
683	  MSR's for some register accesses, mostly but not limited to thermal
684	  and power. Drivers may query the availability of this device to
685	  determine if they need the sideband in order to work on these
686	  platforms. The sideband is available on the following SoC products.
687	  This list is not meant to be exclusive.
688	   - BayTrail
689	   - Braswell
690	   - Quark
691
692	  You should say Y if you are running a kernel on one of these SoC's.
693
694config IOSF_MBI_DEBUG
695	bool "Enable IOSF sideband access through debugfs"
696	depends on IOSF_MBI && DEBUG_FS
697	help
698	  Select this option to expose the IOSF sideband access registers (MCR,
699	  MDR, MCRX) through debugfs to write and read register information from
700	  different units on the SoC. This is most useful for obtaining device
701	  state information for debug and analysis. As this is a general access
702	  mechanism, users of this option would have specific knowledge of the
703	  device they want to access.
704
705	  If you don't require the option or are in doubt, say N.
706
707config X86_RDC321X
708	bool "RDC R-321x SoC"
709	depends on X86_32
710	depends on X86_EXTENDED_PLATFORM
711	select M486
712	select X86_REBOOTFIXUPS
713	help
714	  This option is needed for RDC R-321x system-on-chip, also known
715	  as R-8610-(G).
716	  If you don't have one of these chips, you should say N here.
717
718config X86_32_NON_STANDARD
719	bool "Support non-standard 32-bit SMP architectures"
720	depends on X86_32 && SMP
721	depends on X86_EXTENDED_PLATFORM
722	help
723	  This option compiles in the bigsmp and STA2X11 default
724	  subarchitectures.  It is intended for a generic binary
725	  kernel. If you select them all, kernel will probe it one by
726	  one and will fallback to default.
727
728# Alphabetically sorted list of Non standard 32 bit platforms
729
730config X86_SUPPORTS_MEMORY_FAILURE
731	def_bool y
732	# MCE code calls memory_failure():
733	depends on X86_MCE
734	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
735	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
736	depends on X86_64 || !SPARSEMEM
737	select ARCH_SUPPORTS_MEMORY_FAILURE
738
739config STA2X11
740	bool "STA2X11 Companion Chip Support"
741	depends on X86_32_NON_STANDARD && PCI
742	select SWIOTLB
743	select MFD_STA2X11
744	select GPIOLIB
745	help
746	  This adds support for boards based on the STA2X11 IO-Hub,
747	  a.k.a. "ConneXt". The chip is used in place of the standard
748	  PC chipset, so all "standard" peripherals are missing. If this
749	  option is selected the kernel will still be able to boot on
750	  standard PC machines.
751
752config X86_32_IRIS
753	tristate "Eurobraille/Iris poweroff module"
754	depends on X86_32
755	help
756	  The Iris machines from EuroBraille do not have APM or ACPI support
757	  to shut themselves down properly.  A special I/O sequence is
758	  needed to do so, which is what this module does at
759	  kernel shutdown.
760
761	  This is only for Iris machines from EuroBraille.
762
763	  If unused, say N.
764
765config SCHED_OMIT_FRAME_POINTER
766	def_bool y
767	prompt "Single-depth WCHAN output"
768	depends on X86
769	help
770	  Calculate simpler /proc/<PID>/wchan values. If this option
771	  is disabled then wchan values will recurse back to the
772	  caller function. This provides more accurate wchan values,
773	  at the expense of slightly more scheduling overhead.
774
775	  If in doubt, say "Y".
776
777menuconfig HYPERVISOR_GUEST
778	bool "Linux guest support"
779	help
780	  Say Y here to enable options for running Linux under various hyper-
781	  visors. This option enables basic hypervisor detection and platform
782	  setup.
783
784	  If you say N, all options in this submenu will be skipped and
785	  disabled, and Linux guest support won't be built in.
786
787if HYPERVISOR_GUEST
788
789config PARAVIRT
790	bool "Enable paravirtualization code"
791	depends on HAVE_STATIC_CALL
792	help
793	  This changes the kernel so it can modify itself when it is run
794	  under a hypervisor, potentially improving performance significantly
795	  over full virtualization.  However, when run without a hypervisor
796	  the kernel is theoretically slower and slightly larger.
797
798config PARAVIRT_XXL
799	bool
800
801config PARAVIRT_DEBUG
802	bool "paravirt-ops debugging"
803	depends on PARAVIRT && DEBUG_KERNEL
804	help
805	  Enable to debug paravirt_ops internals.  Specifically, BUG if
806	  a paravirt_op is missing when it is called.
807
808config PARAVIRT_SPINLOCKS
809	bool "Paravirtualization layer for spinlocks"
810	depends on PARAVIRT && SMP
811	help
812	  Paravirtualized spinlocks allow a pvops backend to replace the
813	  spinlock implementation with something virtualization-friendly
814	  (for example, block the virtual CPU rather than spinning).
815
816	  It has a minimal impact on native kernels and gives a nice performance
817	  benefit on paravirtualized KVM / Xen kernels.
818
819	  If you are unsure how to answer this question, answer Y.
820
821config X86_HV_CALLBACK_VECTOR
822	def_bool n
823
824source "arch/x86/xen/Kconfig"
825
826config KVM_GUEST
827	bool "KVM Guest support (including kvmclock)"
828	depends on PARAVIRT
829	select PARAVIRT_CLOCK
830	select ARCH_CPUIDLE_HALTPOLL
831	select X86_HV_CALLBACK_VECTOR
832	default y
833	help
834	  This option enables various optimizations for running under the KVM
835	  hypervisor. It includes a paravirtualized clock, so that instead
836	  of relying on a PIT (or probably other) emulation by the
837	  underlying device model, the host provides the guest with
838	  timing infrastructure such as time of day, and system time
839
840config ARCH_CPUIDLE_HALTPOLL
841	def_bool n
842	prompt "Disable host haltpoll when loading haltpoll driver"
843	help
844	  If virtualized under KVM, disable host haltpoll.
845
846config PVH
847	bool "Support for running PVH guests"
848	help
849	  This option enables the PVH entry point for guest virtual machines
850	  as specified in the x86/HVM direct boot ABI.
851
852config PARAVIRT_TIME_ACCOUNTING
853	bool "Paravirtual steal time accounting"
854	depends on PARAVIRT
855	help
856	  Select this option to enable fine granularity task steal time
857	  accounting. Time spent executing other tasks in parallel with
858	  the current vCPU is discounted from the vCPU power. To account for
859	  that, there can be a small performance impact.
860
861	  If in doubt, say N here.
862
863config PARAVIRT_CLOCK
864	bool
865
866config JAILHOUSE_GUEST
867	bool "Jailhouse non-root cell support"
868	depends on X86_64 && PCI
869	select X86_PM_TIMER
870	help
871	  This option allows to run Linux as guest in a Jailhouse non-root
872	  cell. You can leave this option disabled if you only want to start
873	  Jailhouse and run Linux afterwards in the root cell.
874
875config ACRN_GUEST
876	bool "ACRN Guest support"
877	depends on X86_64
878	select X86_HV_CALLBACK_VECTOR
879	help
880	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
881	  a flexible, lightweight reference open-source hypervisor, built with
882	  real-time and safety-criticality in mind. It is built for embedded
883	  IOT with small footprint and real-time features. More details can be
884	  found in https://projectacrn.org/.
885
886config INTEL_TDX_GUEST
887	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
888	depends on X86_64 && CPU_SUP_INTEL
889	depends on X86_X2APIC
890	depends on EFI_STUB
891	select ARCH_HAS_CC_PLATFORM
892	select X86_MEM_ENCRYPT
893	select X86_MCE
894	select UNACCEPTED_MEMORY
895	help
896	  Support running as a guest under Intel TDX.  Without this support,
897	  the guest kernel can not boot or run under TDX.
898	  TDX includes memory encryption and integrity capabilities
899	  which protect the confidentiality and integrity of guest
900	  memory contents and CPU state. TDX guests are protected from
901	  some attacks from the VMM.
902
903endif # HYPERVISOR_GUEST
904
905source "arch/x86/Kconfig.cpu"
906
907config HPET_TIMER
908	def_bool X86_64
909	prompt "HPET Timer Support" if X86_32
910	help
911	  Use the IA-PC HPET (High Precision Event Timer) to manage
912	  time in preference to the PIT and RTC, if a HPET is
913	  present.
914	  HPET is the next generation timer replacing legacy 8254s.
915	  The HPET provides a stable time base on SMP
916	  systems, unlike the TSC, but it is more expensive to access,
917	  as it is off-chip.  The interface used is documented
918	  in the HPET spec, revision 1.
919
920	  You can safely choose Y here.  However, HPET will only be
921	  activated if the platform and the BIOS support this feature.
922	  Otherwise the 8254 will be used for timing services.
923
924	  Choose N to continue using the legacy 8254 timer.
925
926config HPET_EMULATE_RTC
927	def_bool y
928	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
929
930# Mark as expert because too many people got it wrong.
931# The code disables itself when not needed.
932config DMI
933	default y
934	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
935	bool "Enable DMI scanning" if EXPERT
936	help
937	  Enabled scanning of DMI to identify machine quirks. Say Y
938	  here unless you have verified that your setup is not
939	  affected by entries in the DMI blacklist. Required by PNP
940	  BIOS code.
941
942config GART_IOMMU
943	bool "Old AMD GART IOMMU support"
944	select DMA_OPS
945	select IOMMU_HELPER
946	select SWIOTLB
947	depends on X86_64 && PCI && AMD_NB
948	help
949	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
950	  GART based hardware IOMMUs.
951
952	  The GART supports full DMA access for devices with 32-bit access
953	  limitations, on systems with more than 3 GB. This is usually needed
954	  for USB, sound, many IDE/SATA chipsets and some other devices.
955
956	  Newer systems typically have a modern AMD IOMMU, supported via
957	  the CONFIG_AMD_IOMMU=y config option.
958
959	  In normal configurations this driver is only active when needed:
960	  there's more than 3 GB of memory and the system contains a
961	  32-bit limited device.
962
963	  If unsure, say Y.
964
965config BOOT_VESA_SUPPORT
966	bool
967	help
968	  If true, at least one selected framebuffer driver can take advantage
969	  of VESA video modes set at an early boot stage via the vga= parameter.
970
971config MAXSMP
972	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
973	depends on X86_64 && SMP && DEBUG_KERNEL
974	select CPUMASK_OFFSTACK
975	help
976	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
977	  If unsure, say N.
978
979#
980# The maximum number of CPUs supported:
981#
982# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
983# and which can be configured interactively in the
984# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
985#
986# The ranges are different on 32-bit and 64-bit kernels, depending on
987# hardware capabilities and scalability features of the kernel.
988#
989# ( If MAXSMP is enabled we just use the highest possible value and disable
990#   interactive configuration. )
991#
992
993config NR_CPUS_RANGE_BEGIN
994	int
995	default NR_CPUS_RANGE_END if MAXSMP
996	default    1 if !SMP
997	default    2
998
999config NR_CPUS_RANGE_END
1000	int
1001	depends on X86_32
1002	default   64 if  SMP &&  X86_BIGSMP
1003	default    8 if  SMP && !X86_BIGSMP
1004	default    1 if !SMP
1005
1006config NR_CPUS_RANGE_END
1007	int
1008	depends on X86_64
1009	default 8192 if  SMP && CPUMASK_OFFSTACK
1010	default  512 if  SMP && !CPUMASK_OFFSTACK
1011	default    1 if !SMP
1012
1013config NR_CPUS_DEFAULT
1014	int
1015	depends on X86_32
1016	default   32 if  X86_BIGSMP
1017	default    8 if  SMP
1018	default    1 if !SMP
1019
1020config NR_CPUS_DEFAULT
1021	int
1022	depends on X86_64
1023	default 8192 if  MAXSMP
1024	default   64 if  SMP
1025	default    1 if !SMP
1026
1027config NR_CPUS
1028	int "Maximum number of CPUs" if SMP && !MAXSMP
1029	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1030	default NR_CPUS_DEFAULT
1031	help
1032	  This allows you to specify the maximum number of CPUs which this
1033	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1034	  supported value is 8192, otherwise the maximum value is 512.  The
1035	  minimum value which makes sense is 2.
1036
1037	  This is purely to save memory: each supported CPU adds about 8KB
1038	  to the kernel image.
1039
1040config SCHED_CLUSTER
1041	bool "Cluster scheduler support"
1042	depends on SMP
1043	default y
1044	help
1045	  Cluster scheduler support improves the CPU scheduler's decision
1046	  making when dealing with machines that have clusters of CPUs.
1047	  Cluster usually means a couple of CPUs which are placed closely
1048	  by sharing mid-level caches, last-level cache tags or internal
1049	  busses.
1050
1051config SCHED_SMT
1052	def_bool y if SMP
1053
1054config SCHED_MC
1055	def_bool y
1056	prompt "Multi-core scheduler support"
1057	depends on SMP
1058	help
1059	  Multi-core scheduler support improves the CPU scheduler's decision
1060	  making when dealing with multi-core CPU chips at a cost of slightly
1061	  increased overhead in some places. If unsure say N here.
1062
1063config SCHED_MC_PRIO
1064	bool "CPU core priorities scheduler support"
1065	depends on SCHED_MC
1066	select X86_INTEL_PSTATE if CPU_SUP_INTEL
1067	select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
1068	select CPU_FREQ
1069	default y
1070	help
1071	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1072	  core ordering determined at manufacturing time, which allows
1073	  certain cores to reach higher turbo frequencies (when running
1074	  single threaded workloads) than others.
1075
1076	  Enabling this kernel feature teaches the scheduler about
1077	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1078	  scheduler's CPU selection logic accordingly, so that higher
1079	  overall system performance can be achieved.
1080
1081	  This feature will have no effect on CPUs without this feature.
1082
1083	  If unsure say Y here.
1084
1085config UP_LATE_INIT
1086	def_bool y
1087	depends on !SMP && X86_LOCAL_APIC
1088
1089config X86_UP_APIC
1090	bool "Local APIC support on uniprocessors" if !PCI_MSI
1091	default PCI_MSI
1092	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1093	help
1094	  A local APIC (Advanced Programmable Interrupt Controller) is an
1095	  integrated interrupt controller in the CPU. If you have a single-CPU
1096	  system which has a processor with a local APIC, you can say Y here to
1097	  enable and use it. If you say Y here even though your machine doesn't
1098	  have a local APIC, then the kernel will still run with no slowdown at
1099	  all. The local APIC supports CPU-generated self-interrupts (timer,
1100	  performance counters), and the NMI watchdog which detects hard
1101	  lockups.
1102
1103config X86_UP_IOAPIC
1104	bool "IO-APIC support on uniprocessors"
1105	depends on X86_UP_APIC
1106	help
1107	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1108	  SMP-capable replacement for PC-style interrupt controllers. Most
1109	  SMP systems and many recent uniprocessor systems have one.
1110
1111	  If you have a single-CPU system with an IO-APIC, you can say Y here
1112	  to use it. If you say Y here even though your machine doesn't have
1113	  an IO-APIC, then the kernel will still run with no slowdown at all.
1114
1115config X86_LOCAL_APIC
1116	def_bool y
1117	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1118	select IRQ_DOMAIN_HIERARCHY
1119
1120config X86_IO_APIC
1121	def_bool y
1122	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1123
1124config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1125	bool "Reroute for broken boot IRQs"
1126	depends on X86_IO_APIC
1127	help
1128	  This option enables a workaround that fixes a source of
1129	  spurious interrupts. This is recommended when threaded
1130	  interrupt handling is used on systems where the generation of
1131	  superfluous "boot interrupts" cannot be disabled.
1132
1133	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1134	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1135	  kernel does during interrupt handling). On chipsets where this
1136	  boot IRQ generation cannot be disabled, this workaround keeps
1137	  the original IRQ line masked so that only the equivalent "boot
1138	  IRQ" is delivered to the CPUs. The workaround also tells the
1139	  kernel to set up the IRQ handler on the boot IRQ line. In this
1140	  way only one interrupt is delivered to the kernel. Otherwise
1141	  the spurious second interrupt may cause the kernel to bring
1142	  down (vital) interrupt lines.
1143
1144	  Only affects "broken" chipsets. Interrupt sharing may be
1145	  increased on these systems.
1146
1147config X86_MCE
1148	bool "Machine Check / overheating reporting"
1149	select GENERIC_ALLOCATOR
1150	default y
1151	help
1152	  Machine Check support allows the processor to notify the
1153	  kernel if it detects a problem (e.g. overheating, data corruption).
1154	  The action the kernel takes depends on the severity of the problem,
1155	  ranging from warning messages to halting the machine.
1156
1157config X86_MCELOG_LEGACY
1158	bool "Support for deprecated /dev/mcelog character device"
1159	depends on X86_MCE
1160	help
1161	  Enable support for /dev/mcelog which is needed by the old mcelog
1162	  userspace logging daemon. Consider switching to the new generation
1163	  rasdaemon solution.
1164
1165config X86_MCE_INTEL
1166	def_bool y
1167	prompt "Intel MCE features"
1168	depends on X86_MCE && X86_LOCAL_APIC
1169	help
1170	  Additional support for intel specific MCE features such as
1171	  the thermal monitor.
1172
1173config X86_MCE_AMD
1174	def_bool y
1175	prompt "AMD MCE features"
1176	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1177	help
1178	  Additional support for AMD specific MCE features such as
1179	  the DRAM Error Threshold.
1180
1181config X86_ANCIENT_MCE
1182	bool "Support for old Pentium 5 / WinChip machine checks"
1183	depends on X86_32 && X86_MCE
1184	help
1185	  Include support for machine check handling on old Pentium 5 or WinChip
1186	  systems. These typically need to be enabled explicitly on the command
1187	  line.
1188
1189config X86_MCE_THRESHOLD
1190	depends on X86_MCE_AMD || X86_MCE_INTEL
1191	def_bool y
1192
1193config X86_MCE_INJECT
1194	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1195	tristate "Machine check injector support"
1196	help
1197	  Provide support for injecting machine checks for testing purposes.
1198	  If you don't know what a machine check is and you don't do kernel
1199	  QA it is safe to say n.
1200
1201source "arch/x86/events/Kconfig"
1202
1203config X86_LEGACY_VM86
1204	bool "Legacy VM86 support"
1205	depends on X86_32
1206	help
1207	  This option allows user programs to put the CPU into V8086
1208	  mode, which is an 80286-era approximation of 16-bit real mode.
1209
1210	  Some very old versions of X and/or vbetool require this option
1211	  for user mode setting.  Similarly, DOSEMU will use it if
1212	  available to accelerate real mode DOS programs.  However, any
1213	  recent version of DOSEMU, X, or vbetool should be fully
1214	  functional even without kernel VM86 support, as they will all
1215	  fall back to software emulation. Nevertheless, if you are using
1216	  a 16-bit DOS program where 16-bit performance matters, vm86
1217	  mode might be faster than emulation and you might want to
1218	  enable this option.
1219
1220	  Note that any app that works on a 64-bit kernel is unlikely to
1221	  need this option, as 64-bit kernels don't, and can't, support
1222	  V8086 mode. This option is also unrelated to 16-bit protected
1223	  mode and is not needed to run most 16-bit programs under Wine.
1224
1225	  Enabling this option increases the complexity of the kernel
1226	  and slows down exception handling a tiny bit.
1227
1228	  If unsure, say N here.
1229
1230config VM86
1231	bool
1232	default X86_LEGACY_VM86
1233
1234config X86_16BIT
1235	bool "Enable support for 16-bit segments" if EXPERT
1236	default y
1237	depends on MODIFY_LDT_SYSCALL
1238	help
1239	  This option is required by programs like Wine to run 16-bit
1240	  protected mode legacy code on x86 processors.  Disabling
1241	  this option saves about 300 bytes on i386, or around 6K text
1242	  plus 16K runtime memory on x86-64,
1243
1244config X86_ESPFIX32
1245	def_bool y
1246	depends on X86_16BIT && X86_32
1247
1248config X86_ESPFIX64
1249	def_bool y
1250	depends on X86_16BIT && X86_64
1251
1252config X86_VSYSCALL_EMULATION
1253	bool "Enable vsyscall emulation" if EXPERT
1254	default y
1255	depends on X86_64
1256	help
1257	  This enables emulation of the legacy vsyscall page.  Disabling
1258	  it is roughly equivalent to booting with vsyscall=none, except
1259	  that it will also disable the helpful warning if a program
1260	  tries to use a vsyscall.  With this option set to N, offending
1261	  programs will just segfault, citing addresses of the form
1262	  0xffffffffff600?00.
1263
1264	  This option is required by many programs built before 2013, and
1265	  care should be used even with newer programs if set to N.
1266
1267	  Disabling this option saves about 7K of kernel size and
1268	  possibly 4K of additional runtime pagetable memory.
1269
1270config X86_IOPL_IOPERM
1271	bool "IOPERM and IOPL Emulation"
1272	default y
1273	help
1274	  This enables the ioperm() and iopl() syscalls which are necessary
1275	  for legacy applications.
1276
1277	  Legacy IOPL support is an overbroad mechanism which allows user
1278	  space aside of accessing all 65536 I/O ports also to disable
1279	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1280	  capabilities and permission from potentially active security
1281	  modules.
1282
1283	  The emulation restricts the functionality of the syscall to
1284	  only allowing the full range I/O port access, but prevents the
1285	  ability to disable interrupts from user space which would be
1286	  granted if the hardware IOPL mechanism would be used.
1287
1288config TOSHIBA
1289	tristate "Toshiba Laptop support"
1290	depends on X86_32
1291	help
1292	  This adds a driver to safely access the System Management Mode of
1293	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1294	  not work on models with a Phoenix BIOS. The System Management Mode
1295	  is used to set the BIOS and power saving options on Toshiba portables.
1296
1297	  For information on utilities to make use of this driver see the
1298	  Toshiba Linux utilities web site at:
1299	  <http://www.buzzard.org.uk/toshiba/>.
1300
1301	  Say Y if you intend to run this kernel on a Toshiba portable.
1302	  Say N otherwise.
1303
1304config X86_REBOOTFIXUPS
1305	bool "Enable X86 board specific fixups for reboot"
1306	depends on X86_32
1307	help
1308	  This enables chipset and/or board specific fixups to be done
1309	  in order to get reboot to work correctly. This is only needed on
1310	  some combinations of hardware and BIOS. The symptom, for which
1311	  this config is intended, is when reboot ends with a stalled/hung
1312	  system.
1313
1314	  Currently, the only fixup is for the Geode machines using
1315	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1316
1317	  Say Y if you want to enable the fixup. Currently, it's safe to
1318	  enable this option even if you don't need it.
1319	  Say N otherwise.
1320
1321config MICROCODE
1322	def_bool y
1323	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1324
1325config MICROCODE_INITRD32
1326	def_bool y
1327	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1328
1329config MICROCODE_LATE_LOADING
1330	bool "Late microcode loading (DANGEROUS)"
1331	default n
1332	depends on MICROCODE && SMP
1333	help
1334	  Loading microcode late, when the system is up and executing instructions
1335	  is a tricky business and should be avoided if possible. Just the sequence
1336	  of synchronizing all cores and SMT threads is one fragile dance which does
1337	  not guarantee that cores might not softlock after the loading. Therefore,
1338	  use this at your own risk. Late loading taints the kernel unless the
1339	  microcode header indicates that it is safe for late loading via the
1340	  minimal revision check. This minimal revision check can be enforced on
1341	  the kernel command line with "microcode.minrev=Y".
1342
1343config MICROCODE_LATE_FORCE_MINREV
1344	bool "Enforce late microcode loading minimal revision check"
1345	default n
1346	depends on MICROCODE_LATE_LOADING
1347	help
1348	  To prevent that users load microcode late which modifies already
1349	  in use features, newer microcode patches have a minimum revision field
1350	  in the microcode header, which tells the kernel which minimum
1351	  revision must be active in the CPU to safely load that new microcode
1352	  late into the running system. If disabled the check will not
1353	  be enforced but the kernel will be tainted when the minimal
1354	  revision check fails.
1355
1356	  This minimal revision check can also be controlled via the
1357	  "microcode.minrev" parameter on the kernel command line.
1358
1359	  If unsure say Y.
1360
1361config X86_MSR
1362	tristate "/dev/cpu/*/msr - Model-specific register support"
1363	help
1364	  This device gives privileged processes access to the x86
1365	  Model-Specific Registers (MSRs).  It is a character device with
1366	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1367	  MSR accesses are directed to a specific CPU on multi-processor
1368	  systems.
1369
1370config X86_CPUID
1371	tristate "/dev/cpu/*/cpuid - CPU information support"
1372	help
1373	  This device gives processes access to the x86 CPUID instruction to
1374	  be executed on a specific processor.  It is a character device
1375	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1376	  /dev/cpu/31/cpuid.
1377
1378choice
1379	prompt "High Memory Support"
1380	default HIGHMEM4G
1381	depends on X86_32
1382
1383config NOHIGHMEM
1384	bool "off"
1385	help
1386	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1387	  However, the address space of 32-bit x86 processors is only 4
1388	  Gigabytes large. That means that, if you have a large amount of
1389	  physical memory, not all of it can be "permanently mapped" by the
1390	  kernel. The physical memory that's not permanently mapped is called
1391	  "high memory".
1392
1393	  If you are compiling a kernel which will never run on a machine with
1394	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1395	  choice and suitable for most users). This will result in a "3GB/1GB"
1396	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1397	  space and the remaining part of the 4GB virtual memory space is used
1398	  by the kernel to permanently map as much physical memory as
1399	  possible.
1400
1401	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1402	  answer "4GB" here.
1403
1404	  If more than 4 Gigabytes is used then answer "64GB" here. This
1405	  selection turns Intel PAE (Physical Address Extension) mode on.
1406	  PAE implements 3-level paging on IA32 processors. PAE is fully
1407	  supported by Linux, PAE mode is implemented on all recent Intel
1408	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1409	  then the kernel will not boot on CPUs that don't support PAE!
1410
1411	  The actual amount of total physical memory will either be
1412	  auto detected or can be forced by using a kernel command line option
1413	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1414	  your boot loader (lilo or loadlin) about how to pass options to the
1415	  kernel at boot time.)
1416
1417	  If unsure, say "off".
1418
1419config HIGHMEM4G
1420	bool "4GB"
1421	help
1422	  Select this if you have a 32-bit processor and between 1 and 4
1423	  gigabytes of physical RAM.
1424
1425config HIGHMEM64G
1426	bool "64GB"
1427	depends on X86_HAVE_PAE
1428	select X86_PAE
1429	help
1430	  Select this if you have a 32-bit processor and more than 4
1431	  gigabytes of physical RAM.
1432
1433endchoice
1434
1435choice
1436	prompt "Memory split" if EXPERT
1437	default VMSPLIT_3G
1438	depends on X86_32
1439	help
1440	  Select the desired split between kernel and user memory.
1441
1442	  If the address range available to the kernel is less than the
1443	  physical memory installed, the remaining memory will be available
1444	  as "high memory". Accessing high memory is a little more costly
1445	  than low memory, as it needs to be mapped into the kernel first.
1446	  Note that increasing the kernel address space limits the range
1447	  available to user programs, making the address space there
1448	  tighter.  Selecting anything other than the default 3G/1G split
1449	  will also likely make your kernel incompatible with binary-only
1450	  kernel modules.
1451
1452	  If you are not absolutely sure what you are doing, leave this
1453	  option alone!
1454
1455	config VMSPLIT_3G
1456		bool "3G/1G user/kernel split"
1457	config VMSPLIT_3G_OPT
1458		depends on !X86_PAE
1459		bool "3G/1G user/kernel split (for full 1G low memory)"
1460	config VMSPLIT_2G
1461		bool "2G/2G user/kernel split"
1462	config VMSPLIT_2G_OPT
1463		depends on !X86_PAE
1464		bool "2G/2G user/kernel split (for full 2G low memory)"
1465	config VMSPLIT_1G
1466		bool "1G/3G user/kernel split"
1467endchoice
1468
1469config PAGE_OFFSET
1470	hex
1471	default 0xB0000000 if VMSPLIT_3G_OPT
1472	default 0x80000000 if VMSPLIT_2G
1473	default 0x78000000 if VMSPLIT_2G_OPT
1474	default 0x40000000 if VMSPLIT_1G
1475	default 0xC0000000
1476	depends on X86_32
1477
1478config HIGHMEM
1479	def_bool y
1480	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1481
1482config X86_PAE
1483	bool "PAE (Physical Address Extension) Support"
1484	depends on X86_32 && X86_HAVE_PAE
1485	select PHYS_ADDR_T_64BIT
1486	select SWIOTLB
1487	help
1488	  PAE is required for NX support, and furthermore enables
1489	  larger swapspace support for non-overcommit purposes. It
1490	  has the cost of more pagetable lookup overhead, and also
1491	  consumes more pagetable space per process.
1492
1493config X86_5LEVEL
1494	bool "Enable 5-level page tables support"
1495	default y
1496	select DYNAMIC_MEMORY_LAYOUT
1497	select SPARSEMEM_VMEMMAP
1498	depends on X86_64
1499	help
1500	  5-level paging enables access to larger address space:
1501	  up to 128 PiB of virtual address space and 4 PiB of
1502	  physical address space.
1503
1504	  It will be supported by future Intel CPUs.
1505
1506	  A kernel with the option enabled can be booted on machines that
1507	  support 4- or 5-level paging.
1508
1509	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1510	  information.
1511
1512	  Say N if unsure.
1513
1514config X86_DIRECT_GBPAGES
1515	def_bool y
1516	depends on X86_64
1517	help
1518	  Certain kernel features effectively disable kernel
1519	  linear 1 GB mappings (even if the CPU otherwise
1520	  supports them), so don't confuse the user by printing
1521	  that we have them enabled.
1522
1523config X86_CPA_STATISTICS
1524	bool "Enable statistic for Change Page Attribute"
1525	depends on DEBUG_FS
1526	help
1527	  Expose statistics about the Change Page Attribute mechanism, which
1528	  helps to determine the effectiveness of preserving large and huge
1529	  page mappings when mapping protections are changed.
1530
1531config X86_MEM_ENCRYPT
1532	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1533	select DYNAMIC_PHYSICAL_MASK
1534	def_bool n
1535
1536config AMD_MEM_ENCRYPT
1537	bool "AMD Secure Memory Encryption (SME) support"
1538	depends on X86_64 && CPU_SUP_AMD
1539	depends on EFI_STUB
1540	select DMA_COHERENT_POOL
1541	select ARCH_USE_MEMREMAP_PROT
1542	select INSTRUCTION_DECODER
1543	select ARCH_HAS_CC_PLATFORM
1544	select X86_MEM_ENCRYPT
1545	select UNACCEPTED_MEMORY
1546	help
1547	  Say yes to enable support for the encryption of system memory.
1548	  This requires an AMD processor that supports Secure Memory
1549	  Encryption (SME).
1550
1551# Common NUMA Features
1552config NUMA
1553	bool "NUMA Memory Allocation and Scheduler Support"
1554	depends on SMP
1555	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1556	default y if X86_BIGSMP
1557	select USE_PERCPU_NUMA_NODE_ID
1558	select OF_NUMA if OF
1559	help
1560	  Enable NUMA (Non-Uniform Memory Access) support.
1561
1562	  The kernel will try to allocate memory used by a CPU on the
1563	  local memory controller of the CPU and add some more
1564	  NUMA awareness to the kernel.
1565
1566	  For 64-bit this is recommended if the system is Intel Core i7
1567	  (or later), AMD Opteron, or EM64T NUMA.
1568
1569	  For 32-bit this is only needed if you boot a 32-bit
1570	  kernel on a 64-bit NUMA platform.
1571
1572	  Otherwise, you should say N.
1573
1574config AMD_NUMA
1575	def_bool y
1576	prompt "Old style AMD Opteron NUMA detection"
1577	depends on X86_64 && NUMA && PCI
1578	help
1579	  Enable AMD NUMA node topology detection.  You should say Y here if
1580	  you have a multi processor AMD system. This uses an old method to
1581	  read the NUMA configuration directly from the builtin Northbridge
1582	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1583	  which also takes priority if both are compiled in.
1584
1585config X86_64_ACPI_NUMA
1586	def_bool y
1587	prompt "ACPI NUMA detection"
1588	depends on X86_64 && NUMA && ACPI && PCI
1589	select ACPI_NUMA
1590	help
1591	  Enable ACPI SRAT based node topology detection.
1592
1593config NUMA_EMU
1594	bool "NUMA emulation"
1595	depends on NUMA
1596	help
1597	  Enable NUMA emulation. A flat machine will be split
1598	  into virtual nodes when booted with "numa=fake=N", where N is the
1599	  number of nodes. This is only useful for debugging.
1600
1601config NODES_SHIFT
1602	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1603	range 1 10
1604	default "10" if MAXSMP
1605	default "6" if X86_64
1606	default "3"
1607	depends on NUMA
1608	help
1609	  Specify the maximum number of NUMA Nodes available on the target
1610	  system.  Increases memory reserved to accommodate various tables.
1611
1612config ARCH_FLATMEM_ENABLE
1613	def_bool y
1614	depends on X86_32 && !NUMA
1615
1616config ARCH_SPARSEMEM_ENABLE
1617	def_bool y
1618	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1619	select SPARSEMEM_STATIC if X86_32
1620	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1621
1622config ARCH_SPARSEMEM_DEFAULT
1623	def_bool X86_64 || (NUMA && X86_32)
1624
1625config ARCH_SELECT_MEMORY_MODEL
1626	def_bool y
1627	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1628
1629config ARCH_MEMORY_PROBE
1630	bool "Enable sysfs memory/probe interface"
1631	depends on MEMORY_HOTPLUG
1632	help
1633	  This option enables a sysfs memory/probe interface for testing.
1634	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1635	  If you are unsure how to answer this question, answer N.
1636
1637config ARCH_PROC_KCORE_TEXT
1638	def_bool y
1639	depends on X86_64 && PROC_KCORE
1640
1641config ILLEGAL_POINTER_VALUE
1642	hex
1643	default 0 if X86_32
1644	default 0xdead000000000000 if X86_64
1645
1646config X86_PMEM_LEGACY_DEVICE
1647	bool
1648
1649config X86_PMEM_LEGACY
1650	tristate "Support non-standard NVDIMMs and ADR protected memory"
1651	depends on PHYS_ADDR_T_64BIT
1652	depends on BLK_DEV
1653	select X86_PMEM_LEGACY_DEVICE
1654	select NUMA_KEEP_MEMINFO if NUMA
1655	select LIBNVDIMM
1656	help
1657	  Treat memory marked using the non-standard e820 type of 12 as used
1658	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1659	  The kernel will offer these regions to the 'pmem' driver so
1660	  they can be used for persistent storage.
1661
1662	  Say Y if unsure.
1663
1664config HIGHPTE
1665	bool "Allocate 3rd-level pagetables from highmem"
1666	depends on HIGHMEM
1667	help
1668	  The VM uses one page table entry for each page of physical memory.
1669	  For systems with a lot of RAM, this can be wasteful of precious
1670	  low memory.  Setting this option will put user-space page table
1671	  entries in high memory.
1672
1673config X86_CHECK_BIOS_CORRUPTION
1674	bool "Check for low memory corruption"
1675	help
1676	  Periodically check for memory corruption in low memory, which
1677	  is suspected to be caused by BIOS.  Even when enabled in the
1678	  configuration, it is disabled at runtime.  Enable it by
1679	  setting "memory_corruption_check=1" on the kernel command
1680	  line.  By default it scans the low 64k of memory every 60
1681	  seconds; see the memory_corruption_check_size and
1682	  memory_corruption_check_period parameters in
1683	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1684
1685	  When enabled with the default parameters, this option has
1686	  almost no overhead, as it reserves a relatively small amount
1687	  of memory and scans it infrequently.  It both detects corruption
1688	  and prevents it from affecting the running system.
1689
1690	  It is, however, intended as a diagnostic tool; if repeatable
1691	  BIOS-originated corruption always affects the same memory,
1692	  you can use memmap= to prevent the kernel from using that
1693	  memory.
1694
1695config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1696	bool "Set the default setting of memory_corruption_check"
1697	depends on X86_CHECK_BIOS_CORRUPTION
1698	default y
1699	help
1700	  Set whether the default state of memory_corruption_check is
1701	  on or off.
1702
1703config MATH_EMULATION
1704	bool
1705	depends on MODIFY_LDT_SYSCALL
1706	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1707	help
1708	  Linux can emulate a math coprocessor (used for floating point
1709	  operations) if you don't have one. 486DX and Pentium processors have
1710	  a math coprocessor built in, 486SX and 386 do not, unless you added
1711	  a 487DX or 387, respectively. (The messages during boot time can
1712	  give you some hints here ["man dmesg"].) Everyone needs either a
1713	  coprocessor or this emulation.
1714
1715	  If you don't have a math coprocessor, you need to say Y here; if you
1716	  say Y here even though you have a coprocessor, the coprocessor will
1717	  be used nevertheless. (This behavior can be changed with the kernel
1718	  command line option "no387", which comes handy if your coprocessor
1719	  is broken. Try "man bootparam" or see the documentation of your boot
1720	  loader (lilo or loadlin) about how to pass options to the kernel at
1721	  boot time.) This means that it is a good idea to say Y here if you
1722	  intend to use this kernel on different machines.
1723
1724	  More information about the internals of the Linux math coprocessor
1725	  emulation can be found in <file:arch/x86/math-emu/README>.
1726
1727	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1728	  kernel, it won't hurt.
1729
1730config MTRR
1731	def_bool y
1732	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1733	help
1734	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1735	  the Memory Type Range Registers (MTRRs) may be used to control
1736	  processor access to memory ranges. This is most useful if you have
1737	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1738	  allows bus write transfers to be combined into a larger transfer
1739	  before bursting over the PCI/AGP bus. This can increase performance
1740	  of image write operations 2.5 times or more. Saying Y here creates a
1741	  /proc/mtrr file which may be used to manipulate your processor's
1742	  MTRRs. Typically the X server should use this.
1743
1744	  This code has a reasonably generic interface so that similar
1745	  control registers on other processors can be easily supported
1746	  as well:
1747
1748	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1749	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1750	  these, the ARRs are used to emulate the MTRRs.
1751	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1752	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1753	  write-combining. All of these processors are supported by this code
1754	  and it makes sense to say Y here if you have one of them.
1755
1756	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1757	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1758	  can lead to all sorts of problems, so it's good to say Y here.
1759
1760	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1761	  just add about 9 KB to your kernel.
1762
1763	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1764
1765config MTRR_SANITIZER
1766	def_bool y
1767	prompt "MTRR cleanup support"
1768	depends on MTRR
1769	help
1770	  Convert MTRR layout from continuous to discrete, so X drivers can
1771	  add writeback entries.
1772
1773	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1774	  The largest mtrr entry size for a continuous block can be set with
1775	  mtrr_chunk_size.
1776
1777	  If unsure, say Y.
1778
1779config MTRR_SANITIZER_ENABLE_DEFAULT
1780	int "MTRR cleanup enable value (0-1)"
1781	range 0 1
1782	default "0"
1783	depends on MTRR_SANITIZER
1784	help
1785	  Enable mtrr cleanup default value
1786
1787config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1788	int "MTRR cleanup spare reg num (0-7)"
1789	range 0 7
1790	default "1"
1791	depends on MTRR_SANITIZER
1792	help
1793	  mtrr cleanup spare entries default, it can be changed via
1794	  mtrr_spare_reg_nr=N on the kernel command line.
1795
1796config X86_PAT
1797	def_bool y
1798	prompt "x86 PAT support" if EXPERT
1799	depends on MTRR
1800	help
1801	  Use PAT attributes to setup page level cache control.
1802
1803	  PATs are the modern equivalents of MTRRs and are much more
1804	  flexible than MTRRs.
1805
1806	  Say N here if you see bootup problems (boot crash, boot hang,
1807	  spontaneous reboots) or a non-working video driver.
1808
1809	  If unsure, say Y.
1810
1811config ARCH_USES_PG_UNCACHED
1812	def_bool y
1813	depends on X86_PAT
1814
1815config X86_UMIP
1816	def_bool y
1817	prompt "User Mode Instruction Prevention" if EXPERT
1818	help
1819	  User Mode Instruction Prevention (UMIP) is a security feature in
1820	  some x86 processors. If enabled, a general protection fault is
1821	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1822	  executed in user mode. These instructions unnecessarily expose
1823	  information about the hardware state.
1824
1825	  The vast majority of applications do not use these instructions.
1826	  For the very few that do, software emulation is provided in
1827	  specific cases in protected and virtual-8086 modes. Emulated
1828	  results are dummy.
1829
1830config CC_HAS_IBT
1831	# GCC >= 9 and binutils >= 2.29
1832	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1833	# Clang/LLVM >= 14
1834	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1835	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1836	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1837		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1838		  $(as-instr,endbr64)
1839
1840config X86_CET
1841	def_bool n
1842	help
1843	  CET features configured (Shadow stack or IBT)
1844
1845config X86_KERNEL_IBT
1846	prompt "Indirect Branch Tracking"
1847	def_bool y
1848	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1849	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1850	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1851	select OBJTOOL
1852	select X86_CET
1853	help
1854	  Build the kernel with support for Indirect Branch Tracking, a
1855	  hardware support course-grain forward-edge Control Flow Integrity
1856	  protection. It enforces that all indirect calls must land on
1857	  an ENDBR instruction, as such, the compiler will instrument the
1858	  code with them to make this happen.
1859
1860	  In addition to building the kernel with IBT, seal all functions that
1861	  are not indirect call targets, avoiding them ever becoming one.
1862
1863	  This requires LTO like objtool runs and will slow down the build. It
1864	  does significantly reduce the number of ENDBR instructions in the
1865	  kernel image.
1866
1867config X86_INTEL_MEMORY_PROTECTION_KEYS
1868	prompt "Memory Protection Keys"
1869	def_bool y
1870	# Note: only available in 64-bit mode
1871	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1872	select ARCH_USES_HIGH_VMA_FLAGS
1873	select ARCH_HAS_PKEYS
1874	help
1875	  Memory Protection Keys provides a mechanism for enforcing
1876	  page-based protections, but without requiring modification of the
1877	  page tables when an application changes protection domains.
1878
1879	  For details, see Documentation/core-api/protection-keys.rst
1880
1881	  If unsure, say y.
1882
1883choice
1884	prompt "TSX enable mode"
1885	depends on CPU_SUP_INTEL
1886	default X86_INTEL_TSX_MODE_OFF
1887	help
1888	  Intel's TSX (Transactional Synchronization Extensions) feature
1889	  allows to optimize locking protocols through lock elision which
1890	  can lead to a noticeable performance boost.
1891
1892	  On the other hand it has been shown that TSX can be exploited
1893	  to form side channel attacks (e.g. TAA) and chances are there
1894	  will be more of those attacks discovered in the future.
1895
1896	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1897	  might override this decision by tsx=on the command line parameter.
1898	  Even with TSX enabled, the kernel will attempt to enable the best
1899	  possible TAA mitigation setting depending on the microcode available
1900	  for the particular machine.
1901
1902	  This option allows to set the default tsx mode between tsx=on, =off
1903	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1904	  details.
1905
1906	  Say off if not sure, auto if TSX is in use but it should be used on safe
1907	  platforms or on if TSX is in use and the security aspect of tsx is not
1908	  relevant.
1909
1910config X86_INTEL_TSX_MODE_OFF
1911	bool "off"
1912	help
1913	  TSX is disabled if possible - equals to tsx=off command line parameter.
1914
1915config X86_INTEL_TSX_MODE_ON
1916	bool "on"
1917	help
1918	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1919	  line parameter.
1920
1921config X86_INTEL_TSX_MODE_AUTO
1922	bool "auto"
1923	help
1924	  TSX is enabled on TSX capable HW that is believed to be safe against
1925	  side channel attacks- equals the tsx=auto command line parameter.
1926endchoice
1927
1928config X86_SGX
1929	bool "Software Guard eXtensions (SGX)"
1930	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1931	depends on CRYPTO=y
1932	depends on CRYPTO_SHA256=y
1933	select MMU_NOTIFIER
1934	select NUMA_KEEP_MEMINFO if NUMA
1935	select XARRAY_MULTI
1936	help
1937	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1938	  that can be used by applications to set aside private regions of code
1939	  and data, referred to as enclaves. An enclave's private memory can
1940	  only be accessed by code running within the enclave. Accesses from
1941	  outside the enclave, including other enclaves, are disallowed by
1942	  hardware.
1943
1944	  If unsure, say N.
1945
1946config X86_USER_SHADOW_STACK
1947	bool "X86 userspace shadow stack"
1948	depends on AS_WRUSS
1949	depends on X86_64
1950	select ARCH_USES_HIGH_VMA_FLAGS
1951	select X86_CET
1952	help
1953	  Shadow stack protection is a hardware feature that detects function
1954	  return address corruption.  This helps mitigate ROP attacks.
1955	  Applications must be enabled to use it, and old userspace does not
1956	  get protection "for free".
1957
1958	  CPUs supporting shadow stacks were first released in 2020.
1959
1960	  See Documentation/arch/x86/shstk.rst for more information.
1961
1962	  If unsure, say N.
1963
1964config INTEL_TDX_HOST
1965	bool "Intel Trust Domain Extensions (TDX) host support"
1966	depends on CPU_SUP_INTEL
1967	depends on X86_64
1968	depends on KVM_INTEL
1969	depends on X86_X2APIC
1970	select ARCH_KEEP_MEMBLOCK
1971	depends on CONTIG_ALLOC
1972	depends on !KEXEC_CORE
1973	depends on X86_MCE
1974	help
1975	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1976	  host and certain physical attacks.  This option enables necessary TDX
1977	  support in the host kernel to run confidential VMs.
1978
1979	  If unsure, say N.
1980
1981config EFI
1982	bool "EFI runtime service support"
1983	depends on ACPI
1984	select UCS2_STRING
1985	select EFI_RUNTIME_WRAPPERS
1986	select ARCH_USE_MEMREMAP_PROT
1987	select EFI_RUNTIME_MAP if KEXEC_CORE
1988	help
1989	  This enables the kernel to use EFI runtime services that are
1990	  available (such as the EFI variable services).
1991
1992	  This option is only useful on systems that have EFI firmware.
1993	  In addition, you should use the latest ELILO loader available
1994	  at <http://elilo.sourceforge.net> in order to take advantage
1995	  of EFI runtime services. However, even with this option, the
1996	  resultant kernel should continue to boot on existing non-EFI
1997	  platforms.
1998
1999config EFI_STUB
2000	bool "EFI stub support"
2001	depends on EFI
2002	select RELOCATABLE
2003	help
2004	  This kernel feature allows a bzImage to be loaded directly
2005	  by EFI firmware without the use of a bootloader.
2006
2007	  See Documentation/admin-guide/efi-stub.rst for more information.
2008
2009config EFI_HANDOVER_PROTOCOL
2010	bool "EFI handover protocol (DEPRECATED)"
2011	depends on EFI_STUB
2012	default y
2013	help
2014	  Select this in order to include support for the deprecated EFI
2015	  handover protocol, which defines alternative entry points into the
2016	  EFI stub.  This is a practice that has no basis in the UEFI
2017	  specification, and requires a priori knowledge on the part of the
2018	  bootloader about Linux/x86 specific ways of passing the command line
2019	  and initrd, and where in memory those assets may be loaded.
2020
2021	  If in doubt, say Y. Even though the corresponding support is not
2022	  present in upstream GRUB or other bootloaders, most distros build
2023	  GRUB with numerous downstream patches applied, and may rely on the
2024	  handover protocol as as result.
2025
2026config EFI_MIXED
2027	bool "EFI mixed-mode support"
2028	depends on EFI_STUB && X86_64
2029	help
2030	  Enabling this feature allows a 64-bit kernel to be booted
2031	  on a 32-bit firmware, provided that your CPU supports 64-bit
2032	  mode.
2033
2034	  Note that it is not possible to boot a mixed-mode enabled
2035	  kernel via the EFI boot stub - a bootloader that supports
2036	  the EFI handover protocol must be used.
2037
2038	  If unsure, say N.
2039
2040config EFI_FAKE_MEMMAP
2041	bool "Enable EFI fake memory map"
2042	depends on EFI
2043	help
2044	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2045	  this parameter, you can add arbitrary attribute to specific memory
2046	  range by updating original (firmware provided) EFI memmap.  This is
2047	  useful for debugging of EFI memmap related feature, e.g., Address
2048	  Range Mirroring feature.
2049
2050config EFI_MAX_FAKE_MEM
2051	int "maximum allowable number of ranges in efi_fake_mem boot option"
2052	depends on EFI_FAKE_MEMMAP
2053	range 1 128
2054	default 8
2055	help
2056	  Maximum allowable number of ranges in efi_fake_mem boot option.
2057	  Ranges can be set up to this value using comma-separated list.
2058	  The default value is 8.
2059
2060config EFI_RUNTIME_MAP
2061	bool "Export EFI runtime maps to sysfs" if EXPERT
2062	depends on EFI
2063	help
2064	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2065	  That memory map is required by the 2nd kernel to set up EFI virtual
2066	  mappings after kexec, but can also be used for debugging purposes.
2067
2068	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2069
2070source "kernel/Kconfig.hz"
2071
2072config ARCH_SUPPORTS_KEXEC
2073	def_bool y
2074
2075config ARCH_SUPPORTS_KEXEC_FILE
2076	def_bool X86_64
2077
2078config ARCH_SELECTS_KEXEC_FILE
2079	def_bool y
2080	depends on KEXEC_FILE
2081	select HAVE_IMA_KEXEC if IMA
2082
2083config ARCH_SUPPORTS_KEXEC_PURGATORY
2084	def_bool y
2085
2086config ARCH_SUPPORTS_KEXEC_SIG
2087	def_bool y
2088
2089config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2090	def_bool y
2091
2092config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2093	def_bool y
2094
2095config ARCH_SUPPORTS_KEXEC_JUMP
2096	def_bool y
2097
2098config ARCH_SUPPORTS_CRASH_DUMP
2099	def_bool X86_64 || (X86_32 && HIGHMEM)
2100
2101config ARCH_SUPPORTS_CRASH_HOTPLUG
2102	def_bool y
2103
2104config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2105	def_bool CRASH_RESERVE
2106
2107config PHYSICAL_START
2108	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2109	default "0x1000000"
2110	help
2111	  This gives the physical address where the kernel is loaded.
2112
2113	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
2114	  will decompress itself to above physical address and run from there.
2115	  Otherwise, bzImage will run from the address where it has been loaded
2116	  by the boot loader. The only exception is if it is loaded below the
2117	  above physical address, in which case it will relocate itself there.
2118
2119	  In normal kdump cases one does not have to set/change this option
2120	  as now bzImage can be compiled as a completely relocatable image
2121	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2122	  address. This option is mainly useful for the folks who don't want
2123	  to use a bzImage for capturing the crash dump and want to use a
2124	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2125	  to be specifically compiled to run from a specific memory area
2126	  (normally a reserved region) and this option comes handy.
2127
2128	  So if you are using bzImage for capturing the crash dump,
2129	  leave the value here unchanged to 0x1000000 and set
2130	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2131	  for capturing the crash dump change this value to start of
2132	  the reserved region.  In other words, it can be set based on
2133	  the "X" value as specified in the "crashkernel=YM@XM"
2134	  command line boot parameter passed to the panic-ed
2135	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2136	  for more details about crash dumps.
2137
2138	  Usage of bzImage for capturing the crash dump is recommended as
2139	  one does not have to build two kernels. Same kernel can be used
2140	  as production kernel and capture kernel. Above option should have
2141	  gone away after relocatable bzImage support is introduced. But it
2142	  is present because there are users out there who continue to use
2143	  vmlinux for dump capture. This option should go away down the
2144	  line.
2145
2146	  Don't change this unless you know what you are doing.
2147
2148config RELOCATABLE
2149	bool "Build a relocatable kernel"
2150	default y
2151	help
2152	  This builds a kernel image that retains relocation information
2153	  so it can be loaded someplace besides the default 1MB.
2154	  The relocations tend to make the kernel binary about 10% larger,
2155	  but are discarded at runtime.
2156
2157	  One use is for the kexec on panic case where the recovery kernel
2158	  must live at a different physical address than the primary
2159	  kernel.
2160
2161	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2162	  it has been loaded at and the compile time physical address
2163	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2164
2165config RANDOMIZE_BASE
2166	bool "Randomize the address of the kernel image (KASLR)"
2167	depends on RELOCATABLE
2168	default y
2169	help
2170	  In support of Kernel Address Space Layout Randomization (KASLR),
2171	  this randomizes the physical address at which the kernel image
2172	  is decompressed and the virtual address where the kernel
2173	  image is mapped, as a security feature that deters exploit
2174	  attempts relying on knowledge of the location of kernel
2175	  code internals.
2176
2177	  On 64-bit, the kernel physical and virtual addresses are
2178	  randomized separately. The physical address will be anywhere
2179	  between 16MB and the top of physical memory (up to 64TB). The
2180	  virtual address will be randomized from 16MB up to 1GB (9 bits
2181	  of entropy). Note that this also reduces the memory space
2182	  available to kernel modules from 1.5GB to 1GB.
2183
2184	  On 32-bit, the kernel physical and virtual addresses are
2185	  randomized together. They will be randomized from 16MB up to
2186	  512MB (8 bits of entropy).
2187
2188	  Entropy is generated using the RDRAND instruction if it is
2189	  supported. If RDTSC is supported, its value is mixed into
2190	  the entropy pool as well. If neither RDRAND nor RDTSC are
2191	  supported, then entropy is read from the i8254 timer. The
2192	  usable entropy is limited by the kernel being built using
2193	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2194	  minimum of 2MB. As a result, only 10 bits of entropy are
2195	  theoretically possible, but the implementations are further
2196	  limited due to memory layouts.
2197
2198	  If unsure, say Y.
2199
2200# Relocation on x86 needs some additional build support
2201config X86_NEED_RELOCS
2202	def_bool y
2203	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2204
2205config PHYSICAL_ALIGN
2206	hex "Alignment value to which kernel should be aligned"
2207	default "0x200000"
2208	range 0x2000 0x1000000 if X86_32
2209	range 0x200000 0x1000000 if X86_64
2210	help
2211	  This value puts the alignment restrictions on physical address
2212	  where kernel is loaded and run from. Kernel is compiled for an
2213	  address which meets above alignment restriction.
2214
2215	  If bootloader loads the kernel at a non-aligned address and
2216	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2217	  address aligned to above value and run from there.
2218
2219	  If bootloader loads the kernel at a non-aligned address and
2220	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2221	  load address and decompress itself to the address it has been
2222	  compiled for and run from there. The address for which kernel is
2223	  compiled already meets above alignment restrictions. Hence the
2224	  end result is that kernel runs from a physical address meeting
2225	  above alignment restrictions.
2226
2227	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2228	  this value must be a multiple of 0x200000.
2229
2230	  Don't change this unless you know what you are doing.
2231
2232config DYNAMIC_MEMORY_LAYOUT
2233	bool
2234	help
2235	  This option makes base addresses of vmalloc and vmemmap as well as
2236	  __PAGE_OFFSET movable during boot.
2237
2238config RANDOMIZE_MEMORY
2239	bool "Randomize the kernel memory sections"
2240	depends on X86_64
2241	depends on RANDOMIZE_BASE
2242	select DYNAMIC_MEMORY_LAYOUT
2243	default RANDOMIZE_BASE
2244	help
2245	  Randomizes the base virtual address of kernel memory sections
2246	  (physical memory mapping, vmalloc & vmemmap). This security feature
2247	  makes exploits relying on predictable memory locations less reliable.
2248
2249	  The order of allocations remains unchanged. Entropy is generated in
2250	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2251	  configuration have in average 30,000 different possible virtual
2252	  addresses for each memory section.
2253
2254	  If unsure, say Y.
2255
2256config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2257	hex "Physical memory mapping padding" if EXPERT
2258	depends on RANDOMIZE_MEMORY
2259	default "0xa" if MEMORY_HOTPLUG
2260	default "0x0"
2261	range 0x1 0x40 if MEMORY_HOTPLUG
2262	range 0x0 0x40
2263	help
2264	  Define the padding in terabytes added to the existing physical
2265	  memory size during kernel memory randomization. It is useful
2266	  for memory hotplug support but reduces the entropy available for
2267	  address randomization.
2268
2269	  If unsure, leave at the default value.
2270
2271config ADDRESS_MASKING
2272	bool "Linear Address Masking support"
2273	depends on X86_64
2274	help
2275	  Linear Address Masking (LAM) modifies the checking that is applied
2276	  to 64-bit linear addresses, allowing software to use of the
2277	  untranslated address bits for metadata.
2278
2279	  The capability can be used for efficient address sanitizers (ASAN)
2280	  implementation and for optimizations in JITs.
2281
2282config HOTPLUG_CPU
2283	def_bool y
2284	depends on SMP
2285
2286config COMPAT_VDSO
2287	def_bool n
2288	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2289	depends on COMPAT_32
2290	help
2291	  Certain buggy versions of glibc will crash if they are
2292	  presented with a 32-bit vDSO that is not mapped at the address
2293	  indicated in its segment table.
2294
2295	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2296	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2297	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2298	  the only released version with the bug, but OpenSUSE 9
2299	  contains a buggy "glibc 2.3.2".
2300
2301	  The symptom of the bug is that everything crashes on startup, saying:
2302	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2303
2304	  Saying Y here changes the default value of the vdso32 boot
2305	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2306	  This works around the glibc bug but hurts performance.
2307
2308	  If unsure, say N: if you are compiling your own kernel, you
2309	  are unlikely to be using a buggy version of glibc.
2310
2311choice
2312	prompt "vsyscall table for legacy applications"
2313	depends on X86_64
2314	default LEGACY_VSYSCALL_XONLY
2315	help
2316	  Legacy user code that does not know how to find the vDSO expects
2317	  to be able to issue three syscalls by calling fixed addresses in
2318	  kernel space. Since this location is not randomized with ASLR,
2319	  it can be used to assist security vulnerability exploitation.
2320
2321	  This setting can be changed at boot time via the kernel command
2322	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2323	  is deprecated and can only be enabled using the kernel command
2324	  line.
2325
2326	  On a system with recent enough glibc (2.14 or newer) and no
2327	  static binaries, you can say None without a performance penalty
2328	  to improve security.
2329
2330	  If unsure, select "Emulate execution only".
2331
2332	config LEGACY_VSYSCALL_XONLY
2333		bool "Emulate execution only"
2334		help
2335		  The kernel traps and emulates calls into the fixed vsyscall
2336		  address mapping and does not allow reads.  This
2337		  configuration is recommended when userspace might use the
2338		  legacy vsyscall area but support for legacy binary
2339		  instrumentation of legacy code is not needed.  It mitigates
2340		  certain uses of the vsyscall area as an ASLR-bypassing
2341		  buffer.
2342
2343	config LEGACY_VSYSCALL_NONE
2344		bool "None"
2345		help
2346		  There will be no vsyscall mapping at all. This will
2347		  eliminate any risk of ASLR bypass due to the vsyscall
2348		  fixed address mapping. Attempts to use the vsyscalls
2349		  will be reported to dmesg, so that either old or
2350		  malicious userspace programs can be identified.
2351
2352endchoice
2353
2354config CMDLINE_BOOL
2355	bool "Built-in kernel command line"
2356	help
2357	  Allow for specifying boot arguments to the kernel at
2358	  build time.  On some systems (e.g. embedded ones), it is
2359	  necessary or convenient to provide some or all of the
2360	  kernel boot arguments with the kernel itself (that is,
2361	  to not rely on the boot loader to provide them.)
2362
2363	  To compile command line arguments into the kernel,
2364	  set this option to 'Y', then fill in the
2365	  boot arguments in CONFIG_CMDLINE.
2366
2367	  Systems with fully functional boot loaders (i.e. non-embedded)
2368	  should leave this option set to 'N'.
2369
2370config CMDLINE
2371	string "Built-in kernel command string"
2372	depends on CMDLINE_BOOL
2373	default ""
2374	help
2375	  Enter arguments here that should be compiled into the kernel
2376	  image and used at boot time.  If the boot loader provides a
2377	  command line at boot time, it is appended to this string to
2378	  form the full kernel command line, when the system boots.
2379
2380	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2381	  change this behavior.
2382
2383	  In most cases, the command line (whether built-in or provided
2384	  by the boot loader) should specify the device for the root
2385	  file system.
2386
2387config CMDLINE_OVERRIDE
2388	bool "Built-in command line overrides boot loader arguments"
2389	depends on CMDLINE_BOOL && CMDLINE != ""
2390	help
2391	  Set this option to 'Y' to have the kernel ignore the boot loader
2392	  command line, and use ONLY the built-in command line.
2393
2394	  This is used to work around broken boot loaders.  This should
2395	  be set to 'N' under normal conditions.
2396
2397config MODIFY_LDT_SYSCALL
2398	bool "Enable the LDT (local descriptor table)" if EXPERT
2399	default y
2400	help
2401	  Linux can allow user programs to install a per-process x86
2402	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2403	  call.  This is required to run 16-bit or segmented code such as
2404	  DOSEMU or some Wine programs.  It is also used by some very old
2405	  threading libraries.
2406
2407	  Enabling this feature adds a small amount of overhead to
2408	  context switches and increases the low-level kernel attack
2409	  surface.  Disabling it removes the modify_ldt(2) system call.
2410
2411	  Saying 'N' here may make sense for embedded or server kernels.
2412
2413config STRICT_SIGALTSTACK_SIZE
2414	bool "Enforce strict size checking for sigaltstack"
2415	depends on DYNAMIC_SIGFRAME
2416	help
2417	  For historical reasons MINSIGSTKSZ is a constant which became
2418	  already too small with AVX512 support. Add a mechanism to
2419	  enforce strict checking of the sigaltstack size against the
2420	  real size of the FPU frame. This option enables the check
2421	  by default. It can also be controlled via the kernel command
2422	  line option 'strict_sas_size' independent of this config
2423	  switch. Enabling it might break existing applications which
2424	  allocate a too small sigaltstack but 'work' because they
2425	  never get a signal delivered.
2426
2427	  Say 'N' unless you want to really enforce this check.
2428
2429source "kernel/livepatch/Kconfig"
2430
2431endmenu
2432
2433config CC_HAS_NAMED_AS
2434	def_bool CC_IS_GCC && GCC_VERSION >= 90100
2435
2436config CC_HAS_NAMED_AS_FIXED_SANITIZERS
2437	def_bool CC_IS_GCC && GCC_VERSION >= 130300
2438
2439config USE_X86_SEG_SUPPORT
2440	def_bool y
2441	depends on CC_HAS_NAMED_AS
2442	#
2443	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
2444	# (KCSAN) are incompatible with named address spaces with
2445	# GCC < 13.3 - see GCC PR sanitizer/111736.
2446	#
2447	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
2448
2449config CC_HAS_SLS
2450	def_bool $(cc-option,-mharden-sls=all)
2451
2452config CC_HAS_RETURN_THUNK
2453	def_bool $(cc-option,-mfunction-return=thunk-extern)
2454
2455config CC_HAS_ENTRY_PADDING
2456	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2457
2458config FUNCTION_PADDING_CFI
2459	int
2460	default 59 if FUNCTION_ALIGNMENT_64B
2461	default 27 if FUNCTION_ALIGNMENT_32B
2462	default 11 if FUNCTION_ALIGNMENT_16B
2463	default  3 if FUNCTION_ALIGNMENT_8B
2464	default  0
2465
2466# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2467# except Kconfig can't do arithmetic :/
2468config FUNCTION_PADDING_BYTES
2469	int
2470	default FUNCTION_PADDING_CFI if CFI_CLANG
2471	default FUNCTION_ALIGNMENT
2472
2473config CALL_PADDING
2474	def_bool n
2475	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2476	select FUNCTION_ALIGNMENT_16B
2477
2478config FINEIBT
2479	def_bool y
2480	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2481	select CALL_PADDING
2482
2483config HAVE_CALL_THUNKS
2484	def_bool y
2485	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
2486
2487config CALL_THUNKS
2488	def_bool n
2489	select CALL_PADDING
2490
2491config PREFIX_SYMBOLS
2492	def_bool y
2493	depends on CALL_PADDING && !CFI_CLANG
2494
2495menuconfig CPU_MITIGATIONS
2496	bool "Mitigations for CPU vulnerabilities"
2497	default y
2498	help
2499	  Say Y here to enable options which enable mitigations for hardware
2500	  vulnerabilities (usually related to speculative execution).
2501	  Mitigations can be disabled or restricted to SMT systems at runtime
2502	  via the "mitigations" kernel parameter.
2503
2504	  If you say N, all mitigations will be disabled.  This CANNOT be
2505	  overridden at runtime.
2506
2507	  Say 'Y', unless you really know what you are doing.
2508
2509if CPU_MITIGATIONS
2510
2511config MITIGATION_PAGE_TABLE_ISOLATION
2512	bool "Remove the kernel mapping in user mode"
2513	default y
2514	depends on (X86_64 || X86_PAE)
2515	help
2516	  This feature reduces the number of hardware side channels by
2517	  ensuring that the majority of kernel addresses are not mapped
2518	  into userspace.
2519
2520	  See Documentation/arch/x86/pti.rst for more details.
2521
2522config MITIGATION_RETPOLINE
2523	bool "Avoid speculative indirect branches in kernel"
2524	select OBJTOOL if HAVE_OBJTOOL
2525	default y
2526	help
2527	  Compile kernel with the retpoline compiler options to guard against
2528	  kernel-to-user data leaks by avoiding speculative indirect
2529	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2530	  support for full protection. The kernel may run slower.
2531
2532config MITIGATION_RETHUNK
2533	bool "Enable return-thunks"
2534	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2535	select OBJTOOL if HAVE_OBJTOOL
2536	default y if X86_64
2537	help
2538	  Compile the kernel with the return-thunks compiler option to guard
2539	  against kernel-to-user data leaks by avoiding return speculation.
2540	  Requires a compiler with -mfunction-return=thunk-extern
2541	  support for full protection. The kernel may run slower.
2542
2543config MITIGATION_UNRET_ENTRY
2544	bool "Enable UNRET on kernel entry"
2545	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2546	default y
2547	help
2548	  Compile the kernel with support for the retbleed=unret mitigation.
2549
2550config MITIGATION_CALL_DEPTH_TRACKING
2551	bool "Mitigate RSB underflow with call depth tracking"
2552	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2553	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2554	select CALL_THUNKS
2555	default y
2556	help
2557	  Compile the kernel with call depth tracking to mitigate the Intel
2558	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2559	  mitigation is off by default and needs to be enabled on the
2560	  kernel command line via the retbleed=stuff option. For
2561	  non-affected systems the overhead of this option is marginal as
2562	  the call depth tracking is using run-time generated call thunks
2563	  in a compiler generated padding area and call patching. This
2564	  increases text size by ~5%. For non affected systems this space
2565	  is unused. On affected SKL systems this results in a significant
2566	  performance gain over the IBRS mitigation.
2567
2568config CALL_THUNKS_DEBUG
2569	bool "Enable call thunks and call depth tracking debugging"
2570	depends on MITIGATION_CALL_DEPTH_TRACKING
2571	select FUNCTION_ALIGNMENT_32B
2572	default n
2573	help
2574	  Enable call/ret counters for imbalance detection and build in
2575	  a noisy dmesg about callthunks generation and call patching for
2576	  trouble shooting. The debug prints need to be enabled on the
2577	  kernel command line with 'debug-callthunks'.
2578	  Only enable this when you are debugging call thunks as this
2579	  creates a noticeable runtime overhead. If unsure say N.
2580
2581config MITIGATION_IBPB_ENTRY
2582	bool "Enable IBPB on kernel entry"
2583	depends on CPU_SUP_AMD && X86_64
2584	default y
2585	help
2586	  Compile the kernel with support for the retbleed=ibpb mitigation.
2587
2588config MITIGATION_IBRS_ENTRY
2589	bool "Enable IBRS on kernel entry"
2590	depends on CPU_SUP_INTEL && X86_64
2591	default y
2592	help
2593	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2594	  This mitigates both spectre_v2 and retbleed at great cost to
2595	  performance.
2596
2597config MITIGATION_SRSO
2598	bool "Mitigate speculative RAS overflow on AMD"
2599	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2600	default y
2601	help
2602	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2603
2604config MITIGATION_SLS
2605	bool "Mitigate Straight-Line-Speculation"
2606	depends on CC_HAS_SLS && X86_64
2607	select OBJTOOL if HAVE_OBJTOOL
2608	default n
2609	help
2610	  Compile the kernel with straight-line-speculation options to guard
2611	  against straight line speculation. The kernel image might be slightly
2612	  larger.
2613
2614config MITIGATION_GDS_FORCE
2615	bool "Force GDS Mitigation"
2616	depends on CPU_SUP_INTEL
2617	default n
2618	help
2619	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2620	  unprivileged speculative access to data which was previously stored in
2621	  vector registers.
2622
2623	  This option is equivalent to setting gather_data_sampling=force on the
2624	  command line. The microcode mitigation is used if present, otherwise
2625	  AVX is disabled as a mitigation. On affected systems that are missing
2626	  the microcode any userspace code that unconditionally uses AVX will
2627	  break with this option set.
2628
2629	  Setting this option on systems not vulnerable to GDS has no effect.
2630
2631	  If in doubt, say N.
2632
2633config MITIGATION_RFDS
2634	bool "RFDS Mitigation"
2635	depends on CPU_SUP_INTEL
2636	default y
2637	help
2638	  Enable mitigation for Register File Data Sampling (RFDS) by default.
2639	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
2640	  allows unprivileged speculative access to stale data previously
2641	  stored in floating point, vector and integer registers.
2642	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
2643
2644config MITIGATION_SPECTRE_BHI
2645	bool "Mitigate Spectre-BHB (Branch History Injection)"
2646	depends on CPU_SUP_INTEL
2647	default y
2648	help
2649	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2650	  where the branch history buffer is poisoned to speculatively steer
2651	  indirect branches.
2652	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2653
2654endif
2655
2656config ARCH_HAS_ADD_PAGES
2657	def_bool y
2658	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2659
2660menu "Power management and ACPI options"
2661
2662config ARCH_HIBERNATION_HEADER
2663	def_bool y
2664	depends on HIBERNATION
2665
2666source "kernel/power/Kconfig"
2667
2668source "drivers/acpi/Kconfig"
2669
2670config X86_APM_BOOT
2671	def_bool y
2672	depends on APM
2673
2674menuconfig APM
2675	tristate "APM (Advanced Power Management) BIOS support"
2676	depends on X86_32 && PM_SLEEP
2677	help
2678	  APM is a BIOS specification for saving power using several different
2679	  techniques. This is mostly useful for battery powered laptops with
2680	  APM compliant BIOSes. If you say Y here, the system time will be
2681	  reset after a RESUME operation, the /proc/apm device will provide
2682	  battery status information, and user-space programs will receive
2683	  notification of APM "events" (e.g. battery status change).
2684
2685	  If you select "Y" here, you can disable actual use of the APM
2686	  BIOS by passing the "apm=off" option to the kernel at boot time.
2687
2688	  Note that the APM support is almost completely disabled for
2689	  machines with more than one CPU.
2690
2691	  In order to use APM, you will need supporting software. For location
2692	  and more information, read <file:Documentation/power/apm-acpi.rst>
2693	  and the Battery Powered Linux mini-HOWTO, available from
2694	  <http://www.tldp.org/docs.html#howto>.
2695
2696	  This driver does not spin down disk drives (see the hdparm(8)
2697	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2698	  VESA-compliant "green" monitors.
2699
2700	  This driver does not support the TI 4000M TravelMate and the ACER
2701	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2702	  desktop machines also don't have compliant BIOSes, and this driver
2703	  may cause those machines to panic during the boot phase.
2704
2705	  Generally, if you don't have a battery in your machine, there isn't
2706	  much point in using this driver and you should say N. If you get
2707	  random kernel OOPSes or reboots that don't seem to be related to
2708	  anything, try disabling/enabling this option (or disabling/enabling
2709	  APM in your BIOS).
2710
2711	  Some other things you should try when experiencing seemingly random,
2712	  "weird" problems:
2713
2714	  1) make sure that you have enough swap space and that it is
2715	  enabled.
2716	  2) pass the "idle=poll" option to the kernel
2717	  3) switch on floating point emulation in the kernel and pass
2718	  the "no387" option to the kernel
2719	  4) pass the "floppy=nodma" option to the kernel
2720	  5) pass the "mem=4M" option to the kernel (thereby disabling
2721	  all but the first 4 MB of RAM)
2722	  6) make sure that the CPU is not over clocked.
2723	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2724	  8) disable the cache from your BIOS settings
2725	  9) install a fan for the video card or exchange video RAM
2726	  10) install a better fan for the CPU
2727	  11) exchange RAM chips
2728	  12) exchange the motherboard.
2729
2730	  To compile this driver as a module, choose M here: the
2731	  module will be called apm.
2732
2733if APM
2734
2735config APM_IGNORE_USER_SUSPEND
2736	bool "Ignore USER SUSPEND"
2737	help
2738	  This option will ignore USER SUSPEND requests. On machines with a
2739	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2740	  series notebooks, it is necessary to say Y because of a BIOS bug.
2741
2742config APM_DO_ENABLE
2743	bool "Enable PM at boot time"
2744	help
2745	  Enable APM features at boot time. From page 36 of the APM BIOS
2746	  specification: "When disabled, the APM BIOS does not automatically
2747	  power manage devices, enter the Standby State, enter the Suspend
2748	  State, or take power saving steps in response to CPU Idle calls."
2749	  This driver will make CPU Idle calls when Linux is idle (unless this
2750	  feature is turned off -- see "Do CPU IDLE calls", below). This
2751	  should always save battery power, but more complicated APM features
2752	  will be dependent on your BIOS implementation. You may need to turn
2753	  this option off if your computer hangs at boot time when using APM
2754	  support, or if it beeps continuously instead of suspending. Turn
2755	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2756	  T400CDT. This is off by default since most machines do fine without
2757	  this feature.
2758
2759config APM_CPU_IDLE
2760	depends on CPU_IDLE
2761	bool "Make CPU Idle calls when idle"
2762	help
2763	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2764	  On some machines, this can activate improved power savings, such as
2765	  a slowed CPU clock rate, when the machine is idle. These idle calls
2766	  are made after the idle loop has run for some length of time (e.g.,
2767	  333 mS). On some machines, this will cause a hang at boot time or
2768	  whenever the CPU becomes idle. (On machines with more than one CPU,
2769	  this option does nothing.)
2770
2771config APM_DISPLAY_BLANK
2772	bool "Enable console blanking using APM"
2773	help
2774	  Enable console blanking using the APM. Some laptops can use this to
2775	  turn off the LCD backlight when the screen blanker of the Linux
2776	  virtual console blanks the screen. Note that this is only used by
2777	  the virtual console screen blanker, and won't turn off the backlight
2778	  when using the X Window system. This also doesn't have anything to
2779	  do with your VESA-compliant power-saving monitor. Further, this
2780	  option doesn't work for all laptops -- it might not turn off your
2781	  backlight at all, or it might print a lot of errors to the console,
2782	  especially if you are using gpm.
2783
2784config APM_ALLOW_INTS
2785	bool "Allow interrupts during APM BIOS calls"
2786	help
2787	  Normally we disable external interrupts while we are making calls to
2788	  the APM BIOS as a measure to lessen the effects of a badly behaving
2789	  BIOS implementation.  The BIOS should reenable interrupts if it
2790	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2791	  many of the newer IBM Thinkpads.  If you experience hangs when you
2792	  suspend, try setting this to Y.  Otherwise, say N.
2793
2794endif # APM
2795
2796source "drivers/cpufreq/Kconfig"
2797
2798source "drivers/cpuidle/Kconfig"
2799
2800source "drivers/idle/Kconfig"
2801
2802endmenu
2803
2804menu "Bus options (PCI etc.)"
2805
2806choice
2807	prompt "PCI access mode"
2808	depends on X86_32 && PCI
2809	default PCI_GOANY
2810	help
2811	  On PCI systems, the BIOS can be used to detect the PCI devices and
2812	  determine their configuration. However, some old PCI motherboards
2813	  have BIOS bugs and may crash if this is done. Also, some embedded
2814	  PCI-based systems don't have any BIOS at all. Linux can also try to
2815	  detect the PCI hardware directly without using the BIOS.
2816
2817	  With this option, you can specify how Linux should detect the
2818	  PCI devices. If you choose "BIOS", the BIOS will be used,
2819	  if you choose "Direct", the BIOS won't be used, and if you
2820	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2821	  If you choose "Any", the kernel will try MMCONFIG, then the
2822	  direct access method and falls back to the BIOS if that doesn't
2823	  work. If unsure, go with the default, which is "Any".
2824
2825config PCI_GOBIOS
2826	bool "BIOS"
2827
2828config PCI_GOMMCONFIG
2829	bool "MMConfig"
2830
2831config PCI_GODIRECT
2832	bool "Direct"
2833
2834config PCI_GOOLPC
2835	bool "OLPC XO-1"
2836	depends on OLPC
2837
2838config PCI_GOANY
2839	bool "Any"
2840
2841endchoice
2842
2843config PCI_BIOS
2844	def_bool y
2845	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2846
2847# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2848config PCI_DIRECT
2849	def_bool y
2850	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2851
2852config PCI_MMCONFIG
2853	bool "Support mmconfig PCI config space access" if X86_64
2854	default y
2855	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2856	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2857
2858config PCI_OLPC
2859	def_bool y
2860	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2861
2862config PCI_XEN
2863	def_bool y
2864	depends on PCI && XEN
2865
2866config MMCONF_FAM10H
2867	def_bool y
2868	depends on X86_64 && PCI_MMCONFIG && ACPI
2869
2870config PCI_CNB20LE_QUIRK
2871	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2872	depends on PCI
2873	help
2874	  Read the PCI windows out of the CNB20LE host bridge. This allows
2875	  PCI hotplug to work on systems with the CNB20LE chipset which do
2876	  not have ACPI.
2877
2878	  There's no public spec for this chipset, and this functionality
2879	  is known to be incomplete.
2880
2881	  You should say N unless you know you need this.
2882
2883config ISA_BUS
2884	bool "ISA bus support on modern systems" if EXPERT
2885	help
2886	  Expose ISA bus device drivers and options available for selection and
2887	  configuration. Enable this option if your target machine has an ISA
2888	  bus. ISA is an older system, displaced by PCI and newer bus
2889	  architectures -- if your target machine is modern, it probably does
2890	  not have an ISA bus.
2891
2892	  If unsure, say N.
2893
2894# x86_64 have no ISA slots, but can have ISA-style DMA.
2895config ISA_DMA_API
2896	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2897	default y
2898	help
2899	  Enables ISA-style DMA support for devices requiring such controllers.
2900	  If unsure, say Y.
2901
2902if X86_32
2903
2904config ISA
2905	bool "ISA support"
2906	help
2907	  Find out whether you have ISA slots on your motherboard.  ISA is the
2908	  name of a bus system, i.e. the way the CPU talks to the other stuff
2909	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2910	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2911	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2912
2913config SCx200
2914	tristate "NatSemi SCx200 support"
2915	help
2916	  This provides basic support for National Semiconductor's
2917	  (now AMD's) Geode processors.  The driver probes for the
2918	  PCI-IDs of several on-chip devices, so its a good dependency
2919	  for other scx200_* drivers.
2920
2921	  If compiled as a module, the driver is named scx200.
2922
2923config SCx200HR_TIMER
2924	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2925	depends on SCx200
2926	default y
2927	help
2928	  This driver provides a clocksource built upon the on-chip
2929	  27MHz high-resolution timer.  Its also a workaround for
2930	  NSC Geode SC-1100's buggy TSC, which loses time when the
2931	  processor goes idle (as is done by the scheduler).  The
2932	  other workaround is idle=poll boot option.
2933
2934config OLPC
2935	bool "One Laptop Per Child support"
2936	depends on !X86_PAE
2937	select GPIOLIB
2938	select OF
2939	select OF_PROMTREE
2940	select IRQ_DOMAIN
2941	select OLPC_EC
2942	help
2943	  Add support for detecting the unique features of the OLPC
2944	  XO hardware.
2945
2946config OLPC_XO1_PM
2947	bool "OLPC XO-1 Power Management"
2948	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2949	help
2950	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2951
2952config OLPC_XO1_RTC
2953	bool "OLPC XO-1 Real Time Clock"
2954	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2955	help
2956	  Add support for the XO-1 real time clock, which can be used as a
2957	  programmable wakeup source.
2958
2959config OLPC_XO1_SCI
2960	bool "OLPC XO-1 SCI extras"
2961	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2962	depends on INPUT=y
2963	select POWER_SUPPLY
2964	help
2965	  Add support for SCI-based features of the OLPC XO-1 laptop:
2966	   - EC-driven system wakeups
2967	   - Power button
2968	   - Ebook switch
2969	   - Lid switch
2970	   - AC adapter status updates
2971	   - Battery status updates
2972
2973config OLPC_XO15_SCI
2974	bool "OLPC XO-1.5 SCI extras"
2975	depends on OLPC && ACPI
2976	select POWER_SUPPLY
2977	help
2978	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2979	   - EC-driven system wakeups
2980	   - AC adapter status updates
2981	   - Battery status updates
2982
2983config ALIX
2984	bool "PCEngines ALIX System Support (LED setup)"
2985	select GPIOLIB
2986	help
2987	  This option enables system support for the PCEngines ALIX.
2988	  At present this just sets up LEDs for GPIO control on
2989	  ALIX2/3/6 boards.  However, other system specific setup should
2990	  get added here.
2991
2992	  Note: You must still enable the drivers for GPIO and LED support
2993	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2994
2995	  Note: You have to set alix.force=1 for boards with Award BIOS.
2996
2997config NET5501
2998	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2999	select GPIOLIB
3000	help
3001	  This option enables system support for the Soekris Engineering net5501.
3002
3003config GEOS
3004	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
3005	select GPIOLIB
3006	depends on DMI
3007	help
3008	  This option enables system support for the Traverse Technologies GEOS.
3009
3010config TS5500
3011	bool "Technologic Systems TS-5500 platform support"
3012	depends on MELAN
3013	select CHECK_SIGNATURE
3014	select NEW_LEDS
3015	select LEDS_CLASS
3016	help
3017	  This option enables system support for the Technologic Systems TS-5500.
3018
3019endif # X86_32
3020
3021config AMD_NB
3022	def_bool y
3023	depends on CPU_SUP_AMD && PCI
3024
3025endmenu
3026
3027menu "Binary Emulations"
3028
3029config IA32_EMULATION
3030	bool "IA32 Emulation"
3031	depends on X86_64
3032	select ARCH_WANT_OLD_COMPAT_IPC
3033	select BINFMT_ELF
3034	select COMPAT_OLD_SIGACTION
3035	help
3036	  Include code to run legacy 32-bit programs under a
3037	  64-bit kernel. You should likely turn this on, unless you're
3038	  100% sure that you don't have any 32-bit programs left.
3039
3040config IA32_EMULATION_DEFAULT_DISABLED
3041	bool "IA32 emulation disabled by default"
3042	default n
3043	depends on IA32_EMULATION
3044	help
3045	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3046	  processes and access to 32-bit syscalls. If unsure, leave it to its
3047	  default value.
3048
3049config X86_X32_ABI
3050	bool "x32 ABI for 64-bit mode"
3051	depends on X86_64
3052	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3053	# compressed debug sections to x86_x32 properly:
3054	# https://github.com/ClangBuiltLinux/linux/issues/514
3055	# https://github.com/ClangBuiltLinux/linux/issues/1141
3056	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3057	help
3058	  Include code to run binaries for the x32 native 32-bit ABI
3059	  for 64-bit processors.  An x32 process gets access to the
3060	  full 64-bit register file and wide data path while leaving
3061	  pointers at 32 bits for smaller memory footprint.
3062
3063config COMPAT_32
3064	def_bool y
3065	depends on IA32_EMULATION || X86_32
3066	select HAVE_UID16
3067	select OLD_SIGSUSPEND3
3068
3069config COMPAT
3070	def_bool y
3071	depends on IA32_EMULATION || X86_X32_ABI
3072
3073config COMPAT_FOR_U64_ALIGNMENT
3074	def_bool y
3075	depends on COMPAT
3076
3077endmenu
3078
3079config HAVE_ATOMIC_IOMAP
3080	def_bool y
3081	depends on X86_32
3082
3083source "arch/x86/kvm/Kconfig"
3084
3085source "arch/x86/Kconfig.assembler"
3086