xref: /linux/arch/x86/Kconfig (revision 76d9b92e68f2bb55890f935c5143f4fef97a935d)
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_KERNEL_FPU_SUPPORT
89	select ARCH_HAS_MEM_ENCRYPT
90	select ARCH_HAS_MEMBARRIER_SYNC_CORE
91	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
92	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
93	select ARCH_HAS_PMEM_API		if X86_64
94	select ARCH_HAS_PTE_DEVMAP		if X86_64
95	select ARCH_HAS_PTE_SPECIAL
96	select ARCH_HAS_HW_PTE_YOUNG
97	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
98	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
99	select ARCH_HAS_COPY_MC			if X86_64
100	select ARCH_HAS_SET_MEMORY
101	select ARCH_HAS_SET_DIRECT_MAP
102	select ARCH_HAS_STRICT_KERNEL_RWX
103	select ARCH_HAS_STRICT_MODULE_RWX
104	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
105	select ARCH_HAS_SYSCALL_WRAPPER
106	select ARCH_HAS_UBSAN
107	select ARCH_HAS_DEBUG_WX
108	select ARCH_HAS_ZONE_DMA_SET if EXPERT
109	select ARCH_HAVE_NMI_SAFE_CMPXCHG
110	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
111	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
112	select ARCH_MIGHT_HAVE_PC_PARPORT
113	select ARCH_MIGHT_HAVE_PC_SERIO
114	select ARCH_STACKWALK
115	select ARCH_SUPPORTS_ACPI
116	select ARCH_SUPPORTS_ATOMIC_RMW
117	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
118	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
119	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
120	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
121	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
122	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
123	select ARCH_SUPPORTS_LTO_CLANG
124	select ARCH_SUPPORTS_LTO_CLANG_THIN
125	select ARCH_USE_BUILTIN_BSWAP
126	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
127	select ARCH_USE_MEMTEST
128	select ARCH_USE_QUEUED_RWLOCKS
129	select ARCH_USE_QUEUED_SPINLOCKS
130	select ARCH_USE_SYM_ANNOTATIONS
131	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
132	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
133	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
134	select ARCH_WANTS_NO_INSTR
135	select ARCH_WANT_GENERAL_HUGETLB
136	select ARCH_WANT_HUGE_PMD_SHARE
137	select ARCH_WANT_LD_ORPHAN_WARN
138	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
139	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
140	select ARCH_WANTS_THP_SWAP		if X86_64
141	select ARCH_HAS_PARANOID_L1D_FLUSH
142	select BUILDTIME_TABLE_SORT
143	select CLKEVT_I8253
144	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
145	select CLOCKSOURCE_WATCHDOG
146	# Word-size accesses may read uninitialized data past the trailing \0
147	# in strings and cause false KMSAN reports.
148	select DCACHE_WORD_ACCESS		if !KMSAN
149	select DYNAMIC_SIGFRAME
150	select EDAC_ATOMIC_SCRUB
151	select EDAC_SUPPORT
152	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
153	select GENERIC_CLOCKEVENTS_BROADCAST_IDLE	if GENERIC_CLOCKEVENTS_BROADCAST
154	select GENERIC_CLOCKEVENTS_MIN_ADJUST
155	select GENERIC_CMOS_UPDATE
156	select GENERIC_CPU_AUTOPROBE
157	select GENERIC_CPU_DEVICES
158	select GENERIC_CPU_VULNERABILITIES
159	select GENERIC_EARLY_IOREMAP
160	select GENERIC_ENTRY
161	select GENERIC_IOMAP
162	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
163	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
164	select GENERIC_IRQ_MIGRATION		if SMP
165	select GENERIC_IRQ_PROBE
166	select GENERIC_IRQ_RESERVATION_MODE
167	select GENERIC_IRQ_SHOW
168	select GENERIC_PENDING_IRQ		if SMP
169	select GENERIC_PTDUMP
170	select GENERIC_SMP_IDLE_THREAD
171	select GENERIC_TIME_VSYSCALL
172	select GENERIC_GETTIMEOFDAY
173	select GENERIC_VDSO_TIME_NS
174	select GENERIC_VDSO_OVERFLOW_PROTECT
175	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
176	select HARDIRQS_SW_RESEND
177	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
178	select HAS_IOPORT
179	select HAVE_ACPI_APEI			if ACPI
180	select HAVE_ACPI_APEI_NMI		if ACPI
181	select HAVE_ALIGNED_STRUCT_PAGE
182	select HAVE_ARCH_AUDITSYSCALL
183	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
184	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
185	select HAVE_ARCH_JUMP_LABEL
186	select HAVE_ARCH_JUMP_LABEL_RELATIVE
187	select HAVE_ARCH_KASAN			if X86_64
188	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
189	select HAVE_ARCH_KFENCE
190	select HAVE_ARCH_KMSAN			if X86_64
191	select HAVE_ARCH_KGDB
192	select HAVE_ARCH_MMAP_RND_BITS		if MMU
193	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
194	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
195	select HAVE_ARCH_PREL32_RELOCATIONS
196	select HAVE_ARCH_SECCOMP_FILTER
197	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
198	select HAVE_ARCH_STACKLEAK
199	select HAVE_ARCH_TRACEHOOK
200	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
201	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
202	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
203	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
204	select HAVE_ARCH_VMAP_STACK		if X86_64
205	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
206	select HAVE_ARCH_WITHIN_STACK_FRAMES
207	select HAVE_ASM_MODVERSIONS
208	select HAVE_CMPXCHG_DOUBLE
209	select HAVE_CMPXCHG_LOCAL
210	select HAVE_CONTEXT_TRACKING_USER		if X86_64
211	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
212	select HAVE_C_RECORDMCOUNT
213	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
214	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
215	select HAVE_BUILDTIME_MCOUNT_SORT
216	select HAVE_DEBUG_KMEMLEAK
217	select HAVE_DMA_CONTIGUOUS
218	select HAVE_DYNAMIC_FTRACE
219	select HAVE_DYNAMIC_FTRACE_WITH_REGS
220	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
221	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
222	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
223	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
224	select HAVE_EBPF_JIT
225	select HAVE_EFFICIENT_UNALIGNED_ACCESS
226	select HAVE_EISA
227	select HAVE_EXIT_THREAD
228	select HAVE_GUP_FAST
229	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
230	select HAVE_FTRACE_MCOUNT_RECORD
231	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
232	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
233	select HAVE_FUNCTION_TRACER
234	select HAVE_GCC_PLUGINS
235	select HAVE_HW_BREAKPOINT
236	select HAVE_IOREMAP_PROT
237	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
238	select HAVE_IRQ_TIME_ACCOUNTING
239	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
240	select HAVE_KERNEL_BZIP2
241	select HAVE_KERNEL_GZIP
242	select HAVE_KERNEL_LZ4
243	select HAVE_KERNEL_LZMA
244	select HAVE_KERNEL_LZO
245	select HAVE_KERNEL_XZ
246	select HAVE_KERNEL_ZSTD
247	select HAVE_KPROBES
248	select HAVE_KPROBES_ON_FTRACE
249	select HAVE_FUNCTION_ERROR_INJECTION
250	select HAVE_KRETPROBES
251	select HAVE_RETHOOK
252	select HAVE_LIVEPATCH			if X86_64
253	select HAVE_MIXED_BREAKPOINTS_REGS
254	select HAVE_MOD_ARCH_SPECIFIC
255	select HAVE_MOVE_PMD
256	select HAVE_MOVE_PUD
257	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
258	select HAVE_NMI
259	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
260	select HAVE_OBJTOOL			if X86_64
261	select HAVE_OPTPROBES
262	select HAVE_PAGE_SIZE_4KB
263	select HAVE_PCSPKR_PLATFORM
264	select HAVE_PERF_EVENTS
265	select HAVE_PERF_EVENTS_NMI
266	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
267	select HAVE_PCI
268	select HAVE_PERF_REGS
269	select HAVE_PERF_USER_STACK_DUMP
270	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
271	select MMU_GATHER_MERGE_VMAS
272	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
273	select HAVE_REGS_AND_STACK_ACCESS_API
274	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
275	select HAVE_FUNCTION_ARG_ACCESS_API
276	select HAVE_SETUP_PER_CPU_AREA
277	select HAVE_SOFTIRQ_ON_OWN_STACK
278	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
279	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
280	select HAVE_STATIC_CALL
281	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
282	select HAVE_PREEMPT_DYNAMIC_CALL
283	select HAVE_RSEQ
284	select HAVE_RUST			if X86_64
285	select HAVE_SYSCALL_TRACEPOINTS
286	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
287	select HAVE_UNSTABLE_SCHED_CLOCK
288	select HAVE_USER_RETURN_NOTIFIER
289	select HAVE_GENERIC_VDSO
290	select HOTPLUG_PARALLEL			if SMP && X86_64
291	select HOTPLUG_SMT			if SMP
292	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
293	select IRQ_FORCED_THREADING
294	select LOCK_MM_AND_FIND_VMA
295	select NEED_PER_CPU_EMBED_FIRST_CHUNK
296	select NEED_PER_CPU_PAGE_FIRST_CHUNK
297	select NEED_SG_DMA_LENGTH
298	select PCI_DOMAINS			if PCI
299	select PCI_LOCKLESS_CONFIG		if PCI
300	select PERF_EVENTS
301	select RTC_LIB
302	select RTC_MC146818_LIB
303	select SPARSE_IRQ
304	select SYSCTL_EXCEPTION_TRACE
305	select THREAD_INFO_IN_TASK
306	select TRACE_IRQFLAGS_SUPPORT
307	select TRACE_IRQFLAGS_NMI_SUPPORT
308	select USER_STACKTRACE_SUPPORT
309	select HAVE_ARCH_KCSAN			if X86_64
310	select PROC_PID_ARCH_STATUS		if PROC_FS
311	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
312	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
313	select FUNCTION_ALIGNMENT_4B
314	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
315	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
316
317config INSTRUCTION_DECODER
318	def_bool y
319	depends on KPROBES || PERF_EVENTS || UPROBES
320
321config OUTPUT_FORMAT
322	string
323	default "elf32-i386" if X86_32
324	default "elf64-x86-64" if X86_64
325
326config LOCKDEP_SUPPORT
327	def_bool y
328
329config STACKTRACE_SUPPORT
330	def_bool y
331
332config MMU
333	def_bool y
334
335config ARCH_MMAP_RND_BITS_MIN
336	default 28 if 64BIT
337	default 8
338
339config ARCH_MMAP_RND_BITS_MAX
340	default 32 if 64BIT
341	default 16
342
343config ARCH_MMAP_RND_COMPAT_BITS_MIN
344	default 8
345
346config ARCH_MMAP_RND_COMPAT_BITS_MAX
347	default 16
348
349config SBUS
350	bool
351
352config GENERIC_ISA_DMA
353	def_bool y
354	depends on ISA_DMA_API
355
356config GENERIC_CSUM
357	bool
358	default y if KMSAN || KASAN
359
360config GENERIC_BUG
361	def_bool y
362	depends on BUG
363	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
364
365config GENERIC_BUG_RELATIVE_POINTERS
366	bool
367
368config ARCH_MAY_HAVE_PC_FDC
369	def_bool y
370	depends on ISA_DMA_API
371
372config GENERIC_CALIBRATE_DELAY
373	def_bool y
374
375config ARCH_HAS_CPU_RELAX
376	def_bool y
377
378config ARCH_HIBERNATION_POSSIBLE
379	def_bool y
380
381config ARCH_SUSPEND_POSSIBLE
382	def_bool y
383
384config AUDIT_ARCH
385	def_bool y if X86_64
386
387config KASAN_SHADOW_OFFSET
388	hex
389	depends on KASAN
390	default 0xdffffc0000000000
391
392config HAVE_INTEL_TXT
393	def_bool y
394	depends on INTEL_IOMMU && ACPI
395
396config X86_64_SMP
397	def_bool y
398	depends on X86_64 && SMP
399
400config ARCH_SUPPORTS_UPROBES
401	def_bool y
402
403config FIX_EARLYCON_MEM
404	def_bool y
405
406config DYNAMIC_PHYSICAL_MASK
407	bool
408
409config PGTABLE_LEVELS
410	int
411	default 5 if X86_5LEVEL
412	default 4 if X86_64
413	default 3 if X86_PAE
414	default 2
415
416config CC_HAS_SANE_STACKPROTECTOR
417	bool
418	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
419	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
420	help
421	  We have to make sure stack protector is unconditionally disabled if
422	  the compiler produces broken code or if it does not let us control
423	  the segment on 32-bit kernels.
424
425menu "Processor type and features"
426
427config SMP
428	bool "Symmetric multi-processing support"
429	help
430	  This enables support for systems with more than one CPU. If you have
431	  a system with only one CPU, say N. If you have a system with more
432	  than one CPU, say Y.
433
434	  If you say N here, the kernel will run on uni- and multiprocessor
435	  machines, but will use only one CPU of a multiprocessor machine. If
436	  you say Y here, the kernel will run on many, but not all,
437	  uniprocessor machines. On a uniprocessor machine, the kernel
438	  will run faster if you say N here.
439
440	  Note that if you say Y here and choose architecture "586" or
441	  "Pentium" under "Processor family", the kernel will not work on 486
442	  architectures. Similarly, multiprocessor kernels for the "PPro"
443	  architecture may not work on all Pentium based boards.
444
445	  People using multiprocessor machines who say Y here should also say
446	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
447	  Management" code will be disabled if you say Y here.
448
449	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
450	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
451	  <http://www.tldp.org/docs.html#howto>.
452
453	  If you don't know what to do here, say N.
454
455config X86_X2APIC
456	bool "Support x2apic"
457	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
458	help
459	  This enables x2apic support on CPUs that have this feature.
460
461	  This allows 32-bit apic IDs (so it can support very large systems),
462	  and accesses the local apic via MSRs not via mmio.
463
464	  Some Intel systems circa 2022 and later are locked into x2APIC mode
465	  and can not fall back to the legacy APIC modes if SGX or TDX are
466	  enabled in the BIOS. They will boot with very reduced functionality
467	  without enabling this option.
468
469	  If you don't know what to do here, say N.
470
471config X86_POSTED_MSI
472	bool "Enable MSI and MSI-x delivery by posted interrupts"
473	depends on X86_64 && IRQ_REMAP
474	help
475	  This enables MSIs that are under interrupt remapping to be delivered as
476	  posted interrupts to the host kernel. Interrupt throughput can
477	  potentially be improved by coalescing CPU notifications during high
478	  frequency bursts.
479
480	  If you don't know what to do here, say N.
481
482config X86_MPPARSE
483	bool "Enable MPS table" if ACPI
484	default y
485	depends on X86_LOCAL_APIC
486	help
487	  For old smp systems that do not have proper acpi support. Newer systems
488	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
489
490config X86_CPU_RESCTRL
491	bool "x86 CPU resource control support"
492	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
493	select KERNFS
494	select PROC_CPU_RESCTRL		if PROC_FS
495	help
496	  Enable x86 CPU resource control support.
497
498	  Provide support for the allocation and monitoring of system resources
499	  usage by the CPU.
500
501	  Intel calls this Intel Resource Director Technology
502	  (Intel(R) RDT). More information about RDT can be found in the
503	  Intel x86 Architecture Software Developer Manual.
504
505	  AMD calls this AMD Platform Quality of Service (AMD QoS).
506	  More information about AMD QoS can be found in the AMD64 Technology
507	  Platform Quality of Service Extensions manual.
508
509	  Say N if unsure.
510
511config X86_FRED
512	bool "Flexible Return and Event Delivery"
513	depends on X86_64
514	help
515	  When enabled, try to use Flexible Return and Event Delivery
516	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
517	  ring transitions and exception/interrupt handling if the
518	  system supports it.
519
520config X86_BIGSMP
521	bool "Support for big SMP systems with more than 8 CPUs"
522	depends on SMP && X86_32
523	help
524	  This option is needed for the systems that have more than 8 CPUs.
525
526config X86_EXTENDED_PLATFORM
527	bool "Support for extended (non-PC) x86 platforms"
528	default y
529	help
530	  If you disable this option then the kernel will only support
531	  standard PC platforms. (which covers the vast majority of
532	  systems out there.)
533
534	  If you enable this option then you'll be able to select support
535	  for the following non-PC x86 platforms, depending on the value of
536	  CONFIG_64BIT.
537
538	  32-bit platforms (CONFIG_64BIT=n):
539		Goldfish (Android emulator)
540		AMD Elan
541		RDC R-321x SoC
542		SGI 320/540 (Visual Workstation)
543		STA2X11-based (e.g. Northville)
544		Moorestown MID devices
545
546	  64-bit platforms (CONFIG_64BIT=y):
547		Numascale NumaChip
548		ScaleMP vSMP
549		SGI Ultraviolet
550
551	  If you have one of these systems, or if you want to build a
552	  generic distribution kernel, say Y here - otherwise say N.
553
554# This is an alphabetically sorted list of 64 bit extended platforms
555# Please maintain the alphabetic order if and when there are additions
556config X86_NUMACHIP
557	bool "Numascale NumaChip"
558	depends on X86_64
559	depends on X86_EXTENDED_PLATFORM
560	depends on NUMA
561	depends on SMP
562	depends on X86_X2APIC
563	depends on PCI_MMCONFIG
564	help
565	  Adds support for Numascale NumaChip large-SMP systems. Needed to
566	  enable more than ~168 cores.
567	  If you don't have one of these, you should say N here.
568
569config X86_VSMP
570	bool "ScaleMP vSMP"
571	select HYPERVISOR_GUEST
572	select PARAVIRT
573	depends on X86_64 && PCI
574	depends on X86_EXTENDED_PLATFORM
575	depends on SMP
576	help
577	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
578	  supposed to run on these EM64T-based machines.  Only choose this option
579	  if you have one of these machines.
580
581config X86_UV
582	bool "SGI Ultraviolet"
583	depends on X86_64
584	depends on X86_EXTENDED_PLATFORM
585	depends on NUMA
586	depends on EFI
587	depends on KEXEC_CORE
588	depends on X86_X2APIC
589	depends on PCI
590	help
591	  This option is needed in order to support SGI Ultraviolet systems.
592	  If you don't have one of these, you should say N here.
593
594# Following is an alphabetically sorted list of 32 bit extended platforms
595# Please maintain the alphabetic order if and when there are additions
596
597config X86_GOLDFISH
598	bool "Goldfish (Virtual Platform)"
599	depends on X86_EXTENDED_PLATFORM
600	help
601	  Enable support for the Goldfish virtual platform used primarily
602	  for Android development. Unless you are building for the Android
603	  Goldfish emulator say N here.
604
605config X86_INTEL_CE
606	bool "CE4100 TV platform"
607	depends on PCI
608	depends on PCI_GODIRECT
609	depends on X86_IO_APIC
610	depends on X86_32
611	depends on X86_EXTENDED_PLATFORM
612	select X86_REBOOTFIXUPS
613	select OF
614	select OF_EARLY_FLATTREE
615	help
616	  Select for the Intel CE media processor (CE4100) SOC.
617	  This option compiles in support for the CE4100 SOC for settop
618	  boxes and media devices.
619
620config X86_INTEL_MID
621	bool "Intel MID platform support"
622	depends on X86_EXTENDED_PLATFORM
623	depends on X86_PLATFORM_DEVICES
624	depends on PCI
625	depends on X86_64 || (PCI_GOANY && X86_32)
626	depends on X86_IO_APIC
627	select I2C
628	select DW_APB_TIMER
629	select INTEL_SCU_PCI
630	help
631	  Select to build a kernel capable of supporting Intel MID (Mobile
632	  Internet Device) platform systems which do not have the PCI legacy
633	  interfaces. If you are building for a PC class system say N here.
634
635	  Intel MID platforms are based on an Intel processor and chipset which
636	  consume less power than most of the x86 derivatives.
637
638config X86_INTEL_QUARK
639	bool "Intel Quark platform support"
640	depends on X86_32
641	depends on X86_EXTENDED_PLATFORM
642	depends on X86_PLATFORM_DEVICES
643	depends on X86_TSC
644	depends on PCI
645	depends on PCI_GOANY
646	depends on X86_IO_APIC
647	select IOSF_MBI
648	select INTEL_IMR
649	select COMMON_CLK
650	help
651	  Select to include support for Quark X1000 SoC.
652	  Say Y here if you have a Quark based system such as the Arduino
653	  compatible Intel Galileo.
654
655config X86_INTEL_LPSS
656	bool "Intel Low Power Subsystem Support"
657	depends on X86 && ACPI && PCI
658	select COMMON_CLK
659	select PINCTRL
660	select IOSF_MBI
661	help
662	  Select to build support for Intel Low Power Subsystem such as
663	  found on Intel Lynxpoint PCH. Selecting this option enables
664	  things like clock tree (common clock framework) and pincontrol
665	  which are needed by the LPSS peripheral drivers.
666
667config X86_AMD_PLATFORM_DEVICE
668	bool "AMD ACPI2Platform devices support"
669	depends on ACPI
670	select COMMON_CLK
671	select PINCTRL
672	help
673	  Select to interpret AMD specific ACPI device to platform device
674	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
675	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
676	  implemented under PINCTRL subsystem.
677
678config IOSF_MBI
679	tristate "Intel SoC IOSF Sideband support for SoC platforms"
680	depends on PCI
681	help
682	  This option enables sideband register access support for Intel SoC
683	  platforms. On these platforms the IOSF sideband is used in lieu of
684	  MSR's for some register accesses, mostly but not limited to thermal
685	  and power. Drivers may query the availability of this device to
686	  determine if they need the sideband in order to work on these
687	  platforms. The sideband is available on the following SoC products.
688	  This list is not meant to be exclusive.
689	   - BayTrail
690	   - Braswell
691	   - Quark
692
693	  You should say Y if you are running a kernel on one of these SoC's.
694
695config IOSF_MBI_DEBUG
696	bool "Enable IOSF sideband access through debugfs"
697	depends on IOSF_MBI && DEBUG_FS
698	help
699	  Select this option to expose the IOSF sideband access registers (MCR,
700	  MDR, MCRX) through debugfs to write and read register information from
701	  different units on the SoC. This is most useful for obtaining device
702	  state information for debug and analysis. As this is a general access
703	  mechanism, users of this option would have specific knowledge of the
704	  device they want to access.
705
706	  If you don't require the option or are in doubt, say N.
707
708config X86_RDC321X
709	bool "RDC R-321x SoC"
710	depends on X86_32
711	depends on X86_EXTENDED_PLATFORM
712	select M486
713	select X86_REBOOTFIXUPS
714	help
715	  This option is needed for RDC R-321x system-on-chip, also known
716	  as R-8610-(G).
717	  If you don't have one of these chips, you should say N here.
718
719config X86_32_NON_STANDARD
720	bool "Support non-standard 32-bit SMP architectures"
721	depends on X86_32 && SMP
722	depends on X86_EXTENDED_PLATFORM
723	help
724	  This option compiles in the bigsmp and STA2X11 default
725	  subarchitectures.  It is intended for a generic binary
726	  kernel. If you select them all, kernel will probe it one by
727	  one and will fallback to default.
728
729# Alphabetically sorted list of Non standard 32 bit platforms
730
731config X86_SUPPORTS_MEMORY_FAILURE
732	def_bool y
733	# MCE code calls memory_failure():
734	depends on X86_MCE
735	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
736	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
737	depends on X86_64 || !SPARSEMEM
738	select ARCH_SUPPORTS_MEMORY_FAILURE
739
740config STA2X11
741	bool "STA2X11 Companion Chip Support"
742	depends on X86_32_NON_STANDARD && PCI
743	select SWIOTLB
744	select MFD_STA2X11
745	select GPIOLIB
746	help
747	  This adds support for boards based on the STA2X11 IO-Hub,
748	  a.k.a. "ConneXt". The chip is used in place of the standard
749	  PC chipset, so all "standard" peripherals are missing. If this
750	  option is selected the kernel will still be able to boot on
751	  standard PC machines.
752
753config X86_32_IRIS
754	tristate "Eurobraille/Iris poweroff module"
755	depends on X86_32
756	help
757	  The Iris machines from EuroBraille do not have APM or ACPI support
758	  to shut themselves down properly.  A special I/O sequence is
759	  needed to do so, which is what this module does at
760	  kernel shutdown.
761
762	  This is only for Iris machines from EuroBraille.
763
764	  If unused, say N.
765
766config SCHED_OMIT_FRAME_POINTER
767	def_bool y
768	prompt "Single-depth WCHAN output"
769	depends on X86
770	help
771	  Calculate simpler /proc/<PID>/wchan values. If this option
772	  is disabled then wchan values will recurse back to the
773	  caller function. This provides more accurate wchan values,
774	  at the expense of slightly more scheduling overhead.
775
776	  If in doubt, say "Y".
777
778menuconfig HYPERVISOR_GUEST
779	bool "Linux guest support"
780	help
781	  Say Y here to enable options for running Linux under various hyper-
782	  visors. This option enables basic hypervisor detection and platform
783	  setup.
784
785	  If you say N, all options in this submenu will be skipped and
786	  disabled, and Linux guest support won't be built in.
787
788if HYPERVISOR_GUEST
789
790config PARAVIRT
791	bool "Enable paravirtualization code"
792	depends on HAVE_STATIC_CALL
793	help
794	  This changes the kernel so it can modify itself when it is run
795	  under a hypervisor, potentially improving performance significantly
796	  over full virtualization.  However, when run without a hypervisor
797	  the kernel is theoretically slower and slightly larger.
798
799config PARAVIRT_XXL
800	bool
801
802config PARAVIRT_DEBUG
803	bool "paravirt-ops debugging"
804	depends on PARAVIRT && DEBUG_KERNEL
805	help
806	  Enable to debug paravirt_ops internals.  Specifically, BUG if
807	  a paravirt_op is missing when it is called.
808
809config PARAVIRT_SPINLOCKS
810	bool "Paravirtualization layer for spinlocks"
811	depends on PARAVIRT && SMP
812	help
813	  Paravirtualized spinlocks allow a pvops backend to replace the
814	  spinlock implementation with something virtualization-friendly
815	  (for example, block the virtual CPU rather than spinning).
816
817	  It has a minimal impact on native kernels and gives a nice performance
818	  benefit on paravirtualized KVM / Xen kernels.
819
820	  If you are unsure how to answer this question, answer Y.
821
822config X86_HV_CALLBACK_VECTOR
823	def_bool n
824
825source "arch/x86/xen/Kconfig"
826
827config KVM_GUEST
828	bool "KVM Guest support (including kvmclock)"
829	depends on PARAVIRT
830	select PARAVIRT_CLOCK
831	select ARCH_CPUIDLE_HALTPOLL
832	select X86_HV_CALLBACK_VECTOR
833	default y
834	help
835	  This option enables various optimizations for running under the KVM
836	  hypervisor. It includes a paravirtualized clock, so that instead
837	  of relying on a PIT (or probably other) emulation by the
838	  underlying device model, the host provides the guest with
839	  timing infrastructure such as time of day, and system time
840
841config ARCH_CPUIDLE_HALTPOLL
842	def_bool n
843	prompt "Disable host haltpoll when loading haltpoll driver"
844	help
845	  If virtualized under KVM, disable host haltpoll.
846
847config PVH
848	bool "Support for running PVH guests"
849	help
850	  This option enables the PVH entry point for guest virtual machines
851	  as specified in the x86/HVM direct boot ABI.
852
853config PARAVIRT_TIME_ACCOUNTING
854	bool "Paravirtual steal time accounting"
855	depends on PARAVIRT
856	help
857	  Select this option to enable fine granularity task steal time
858	  accounting. Time spent executing other tasks in parallel with
859	  the current vCPU is discounted from the vCPU power. To account for
860	  that, there can be a small performance impact.
861
862	  If in doubt, say N here.
863
864config PARAVIRT_CLOCK
865	bool
866
867config JAILHOUSE_GUEST
868	bool "Jailhouse non-root cell support"
869	depends on X86_64 && PCI
870	select X86_PM_TIMER
871	help
872	  This option allows to run Linux as guest in a Jailhouse non-root
873	  cell. You can leave this option disabled if you only want to start
874	  Jailhouse and run Linux afterwards in the root cell.
875
876config ACRN_GUEST
877	bool "ACRN Guest support"
878	depends on X86_64
879	select X86_HV_CALLBACK_VECTOR
880	help
881	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
882	  a flexible, lightweight reference open-source hypervisor, built with
883	  real-time and safety-criticality in mind. It is built for embedded
884	  IOT with small footprint and real-time features. More details can be
885	  found in https://projectacrn.org/.
886
887config INTEL_TDX_GUEST
888	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
889	depends on X86_64 && CPU_SUP_INTEL
890	depends on X86_X2APIC
891	depends on EFI_STUB
892	select ARCH_HAS_CC_PLATFORM
893	select X86_MEM_ENCRYPT
894	select X86_MCE
895	select UNACCEPTED_MEMORY
896	help
897	  Support running as a guest under Intel TDX.  Without this support,
898	  the guest kernel can not boot or run under TDX.
899	  TDX includes memory encryption and integrity capabilities
900	  which protect the confidentiality and integrity of guest
901	  memory contents and CPU state. TDX guests are protected from
902	  some attacks from the VMM.
903
904endif # HYPERVISOR_GUEST
905
906source "arch/x86/Kconfig.cpu"
907
908config HPET_TIMER
909	def_bool X86_64
910	prompt "HPET Timer Support" if X86_32
911	help
912	  Use the IA-PC HPET (High Precision Event Timer) to manage
913	  time in preference to the PIT and RTC, if a HPET is
914	  present.
915	  HPET is the next generation timer replacing legacy 8254s.
916	  The HPET provides a stable time base on SMP
917	  systems, unlike the TSC, but it is more expensive to access,
918	  as it is off-chip.  The interface used is documented
919	  in the HPET spec, revision 1.
920
921	  You can safely choose Y here.  However, HPET will only be
922	  activated if the platform and the BIOS support this feature.
923	  Otherwise the 8254 will be used for timing services.
924
925	  Choose N to continue using the legacy 8254 timer.
926
927config HPET_EMULATE_RTC
928	def_bool y
929	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
930
931# Mark as expert because too many people got it wrong.
932# The code disables itself when not needed.
933config DMI
934	default y
935	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
936	bool "Enable DMI scanning" if EXPERT
937	help
938	  Enabled scanning of DMI to identify machine quirks. Say Y
939	  here unless you have verified that your setup is not
940	  affected by entries in the DMI blacklist. Required by PNP
941	  BIOS code.
942
943config GART_IOMMU
944	bool "Old AMD GART IOMMU support"
945	select DMA_OPS
946	select IOMMU_HELPER
947	select SWIOTLB
948	depends on X86_64 && PCI && AMD_NB
949	help
950	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
951	  GART based hardware IOMMUs.
952
953	  The GART supports full DMA access for devices with 32-bit access
954	  limitations, on systems with more than 3 GB. This is usually needed
955	  for USB, sound, many IDE/SATA chipsets and some other devices.
956
957	  Newer systems typically have a modern AMD IOMMU, supported via
958	  the CONFIG_AMD_IOMMU=y config option.
959
960	  In normal configurations this driver is only active when needed:
961	  there's more than 3 GB of memory and the system contains a
962	  32-bit limited device.
963
964	  If unsure, say Y.
965
966config BOOT_VESA_SUPPORT
967	bool
968	help
969	  If true, at least one selected framebuffer driver can take advantage
970	  of VESA video modes set at an early boot stage via the vga= parameter.
971
972config MAXSMP
973	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
974	depends on X86_64 && SMP && DEBUG_KERNEL
975	select CPUMASK_OFFSTACK
976	help
977	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
978	  If unsure, say N.
979
980#
981# The maximum number of CPUs supported:
982#
983# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
984# and which can be configured interactively in the
985# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
986#
987# The ranges are different on 32-bit and 64-bit kernels, depending on
988# hardware capabilities and scalability features of the kernel.
989#
990# ( If MAXSMP is enabled we just use the highest possible value and disable
991#   interactive configuration. )
992#
993
994config NR_CPUS_RANGE_BEGIN
995	int
996	default NR_CPUS_RANGE_END if MAXSMP
997	default    1 if !SMP
998	default    2
999
1000config NR_CPUS_RANGE_END
1001	int
1002	depends on X86_32
1003	default   64 if  SMP &&  X86_BIGSMP
1004	default    8 if  SMP && !X86_BIGSMP
1005	default    1 if !SMP
1006
1007config NR_CPUS_RANGE_END
1008	int
1009	depends on X86_64
1010	default 8192 if  SMP && CPUMASK_OFFSTACK
1011	default  512 if  SMP && !CPUMASK_OFFSTACK
1012	default    1 if !SMP
1013
1014config NR_CPUS_DEFAULT
1015	int
1016	depends on X86_32
1017	default   32 if  X86_BIGSMP
1018	default    8 if  SMP
1019	default    1 if !SMP
1020
1021config NR_CPUS_DEFAULT
1022	int
1023	depends on X86_64
1024	default 8192 if  MAXSMP
1025	default   64 if  SMP
1026	default    1 if !SMP
1027
1028config NR_CPUS
1029	int "Maximum number of CPUs" if SMP && !MAXSMP
1030	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1031	default NR_CPUS_DEFAULT
1032	help
1033	  This allows you to specify the maximum number of CPUs which this
1034	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1035	  supported value is 8192, otherwise the maximum value is 512.  The
1036	  minimum value which makes sense is 2.
1037
1038	  This is purely to save memory: each supported CPU adds about 8KB
1039	  to the kernel image.
1040
1041config SCHED_CLUSTER
1042	bool "Cluster scheduler support"
1043	depends on SMP
1044	default y
1045	help
1046	  Cluster scheduler support improves the CPU scheduler's decision
1047	  making when dealing with machines that have clusters of CPUs.
1048	  Cluster usually means a couple of CPUs which are placed closely
1049	  by sharing mid-level caches, last-level cache tags or internal
1050	  busses.
1051
1052config SCHED_SMT
1053	def_bool y if SMP
1054
1055config SCHED_MC
1056	def_bool y
1057	prompt "Multi-core scheduler support"
1058	depends on SMP
1059	help
1060	  Multi-core scheduler support improves the CPU scheduler's decision
1061	  making when dealing with multi-core CPU chips at a cost of slightly
1062	  increased overhead in some places. If unsure say N here.
1063
1064config SCHED_MC_PRIO
1065	bool "CPU core priorities scheduler support"
1066	depends on SCHED_MC
1067	select X86_INTEL_PSTATE if CPU_SUP_INTEL
1068	select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
1069	select CPU_FREQ
1070	default y
1071	help
1072	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1073	  core ordering determined at manufacturing time, which allows
1074	  certain cores to reach higher turbo frequencies (when running
1075	  single threaded workloads) than others.
1076
1077	  Enabling this kernel feature teaches the scheduler about
1078	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1079	  scheduler's CPU selection logic accordingly, so that higher
1080	  overall system performance can be achieved.
1081
1082	  This feature will have no effect on CPUs without this feature.
1083
1084	  If unsure say Y here.
1085
1086config UP_LATE_INIT
1087	def_bool y
1088	depends on !SMP && X86_LOCAL_APIC
1089
1090config X86_UP_APIC
1091	bool "Local APIC support on uniprocessors" if !PCI_MSI
1092	default PCI_MSI
1093	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1094	help
1095	  A local APIC (Advanced Programmable Interrupt Controller) is an
1096	  integrated interrupt controller in the CPU. If you have a single-CPU
1097	  system which has a processor with a local APIC, you can say Y here to
1098	  enable and use it. If you say Y here even though your machine doesn't
1099	  have a local APIC, then the kernel will still run with no slowdown at
1100	  all. The local APIC supports CPU-generated self-interrupts (timer,
1101	  performance counters), and the NMI watchdog which detects hard
1102	  lockups.
1103
1104config X86_UP_IOAPIC
1105	bool "IO-APIC support on uniprocessors"
1106	depends on X86_UP_APIC
1107	help
1108	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1109	  SMP-capable replacement for PC-style interrupt controllers. Most
1110	  SMP systems and many recent uniprocessor systems have one.
1111
1112	  If you have a single-CPU system with an IO-APIC, you can say Y here
1113	  to use it. If you say Y here even though your machine doesn't have
1114	  an IO-APIC, then the kernel will still run with no slowdown at all.
1115
1116config X86_LOCAL_APIC
1117	def_bool y
1118	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1119	select IRQ_DOMAIN_HIERARCHY
1120
1121config ACPI_MADT_WAKEUP
1122	def_bool y
1123	depends on X86_64
1124	depends on ACPI
1125	depends on SMP
1126	depends on X86_LOCAL_APIC
1127
1128config X86_IO_APIC
1129	def_bool y
1130	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1131
1132config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1133	bool "Reroute for broken boot IRQs"
1134	depends on X86_IO_APIC
1135	help
1136	  This option enables a workaround that fixes a source of
1137	  spurious interrupts. This is recommended when threaded
1138	  interrupt handling is used on systems where the generation of
1139	  superfluous "boot interrupts" cannot be disabled.
1140
1141	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1142	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1143	  kernel does during interrupt handling). On chipsets where this
1144	  boot IRQ generation cannot be disabled, this workaround keeps
1145	  the original IRQ line masked so that only the equivalent "boot
1146	  IRQ" is delivered to the CPUs. The workaround also tells the
1147	  kernel to set up the IRQ handler on the boot IRQ line. In this
1148	  way only one interrupt is delivered to the kernel. Otherwise
1149	  the spurious second interrupt may cause the kernel to bring
1150	  down (vital) interrupt lines.
1151
1152	  Only affects "broken" chipsets. Interrupt sharing may be
1153	  increased on these systems.
1154
1155config X86_MCE
1156	bool "Machine Check / overheating reporting"
1157	select GENERIC_ALLOCATOR
1158	default y
1159	help
1160	  Machine Check support allows the processor to notify the
1161	  kernel if it detects a problem (e.g. overheating, data corruption).
1162	  The action the kernel takes depends on the severity of the problem,
1163	  ranging from warning messages to halting the machine.
1164
1165config X86_MCELOG_LEGACY
1166	bool "Support for deprecated /dev/mcelog character device"
1167	depends on X86_MCE
1168	help
1169	  Enable support for /dev/mcelog which is needed by the old mcelog
1170	  userspace logging daemon. Consider switching to the new generation
1171	  rasdaemon solution.
1172
1173config X86_MCE_INTEL
1174	def_bool y
1175	prompt "Intel MCE features"
1176	depends on X86_MCE && X86_LOCAL_APIC
1177	help
1178	  Additional support for intel specific MCE features such as
1179	  the thermal monitor.
1180
1181config X86_MCE_AMD
1182	def_bool y
1183	prompt "AMD MCE features"
1184	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1185	help
1186	  Additional support for AMD specific MCE features such as
1187	  the DRAM Error Threshold.
1188
1189config X86_ANCIENT_MCE
1190	bool "Support for old Pentium 5 / WinChip machine checks"
1191	depends on X86_32 && X86_MCE
1192	help
1193	  Include support for machine check handling on old Pentium 5 or WinChip
1194	  systems. These typically need to be enabled explicitly on the command
1195	  line.
1196
1197config X86_MCE_THRESHOLD
1198	depends on X86_MCE_AMD || X86_MCE_INTEL
1199	def_bool y
1200
1201config X86_MCE_INJECT
1202	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1203	tristate "Machine check injector support"
1204	help
1205	  Provide support for injecting machine checks for testing purposes.
1206	  If you don't know what a machine check is and you don't do kernel
1207	  QA it is safe to say n.
1208
1209source "arch/x86/events/Kconfig"
1210
1211config X86_LEGACY_VM86
1212	bool "Legacy VM86 support"
1213	depends on X86_32
1214	help
1215	  This option allows user programs to put the CPU into V8086
1216	  mode, which is an 80286-era approximation of 16-bit real mode.
1217
1218	  Some very old versions of X and/or vbetool require this option
1219	  for user mode setting.  Similarly, DOSEMU will use it if
1220	  available to accelerate real mode DOS programs.  However, any
1221	  recent version of DOSEMU, X, or vbetool should be fully
1222	  functional even without kernel VM86 support, as they will all
1223	  fall back to software emulation. Nevertheless, if you are using
1224	  a 16-bit DOS program where 16-bit performance matters, vm86
1225	  mode might be faster than emulation and you might want to
1226	  enable this option.
1227
1228	  Note that any app that works on a 64-bit kernel is unlikely to
1229	  need this option, as 64-bit kernels don't, and can't, support
1230	  V8086 mode. This option is also unrelated to 16-bit protected
1231	  mode and is not needed to run most 16-bit programs under Wine.
1232
1233	  Enabling this option increases the complexity of the kernel
1234	  and slows down exception handling a tiny bit.
1235
1236	  If unsure, say N here.
1237
1238config VM86
1239	bool
1240	default X86_LEGACY_VM86
1241
1242config X86_16BIT
1243	bool "Enable support for 16-bit segments" if EXPERT
1244	default y
1245	depends on MODIFY_LDT_SYSCALL
1246	help
1247	  This option is required by programs like Wine to run 16-bit
1248	  protected mode legacy code on x86 processors.  Disabling
1249	  this option saves about 300 bytes on i386, or around 6K text
1250	  plus 16K runtime memory on x86-64,
1251
1252config X86_ESPFIX32
1253	def_bool y
1254	depends on X86_16BIT && X86_32
1255
1256config X86_ESPFIX64
1257	def_bool y
1258	depends on X86_16BIT && X86_64
1259
1260config X86_VSYSCALL_EMULATION
1261	bool "Enable vsyscall emulation" if EXPERT
1262	default y
1263	depends on X86_64
1264	help
1265	  This enables emulation of the legacy vsyscall page.  Disabling
1266	  it is roughly equivalent to booting with vsyscall=none, except
1267	  that it will also disable the helpful warning if a program
1268	  tries to use a vsyscall.  With this option set to N, offending
1269	  programs will just segfault, citing addresses of the form
1270	  0xffffffffff600?00.
1271
1272	  This option is required by many programs built before 2013, and
1273	  care should be used even with newer programs if set to N.
1274
1275	  Disabling this option saves about 7K of kernel size and
1276	  possibly 4K of additional runtime pagetable memory.
1277
1278config X86_IOPL_IOPERM
1279	bool "IOPERM and IOPL Emulation"
1280	default y
1281	help
1282	  This enables the ioperm() and iopl() syscalls which are necessary
1283	  for legacy applications.
1284
1285	  Legacy IOPL support is an overbroad mechanism which allows user
1286	  space aside of accessing all 65536 I/O ports also to disable
1287	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1288	  capabilities and permission from potentially active security
1289	  modules.
1290
1291	  The emulation restricts the functionality of the syscall to
1292	  only allowing the full range I/O port access, but prevents the
1293	  ability to disable interrupts from user space which would be
1294	  granted if the hardware IOPL mechanism would be used.
1295
1296config TOSHIBA
1297	tristate "Toshiba Laptop support"
1298	depends on X86_32
1299	help
1300	  This adds a driver to safely access the System Management Mode of
1301	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1302	  not work on models with a Phoenix BIOS. The System Management Mode
1303	  is used to set the BIOS and power saving options on Toshiba portables.
1304
1305	  For information on utilities to make use of this driver see the
1306	  Toshiba Linux utilities web site at:
1307	  <http://www.buzzard.org.uk/toshiba/>.
1308
1309	  Say Y if you intend to run this kernel on a Toshiba portable.
1310	  Say N otherwise.
1311
1312config X86_REBOOTFIXUPS
1313	bool "Enable X86 board specific fixups for reboot"
1314	depends on X86_32
1315	help
1316	  This enables chipset and/or board specific fixups to be done
1317	  in order to get reboot to work correctly. This is only needed on
1318	  some combinations of hardware and BIOS. The symptom, for which
1319	  this config is intended, is when reboot ends with a stalled/hung
1320	  system.
1321
1322	  Currently, the only fixup is for the Geode machines using
1323	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1324
1325	  Say Y if you want to enable the fixup. Currently, it's safe to
1326	  enable this option even if you don't need it.
1327	  Say N otherwise.
1328
1329config MICROCODE
1330	def_bool y
1331	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1332
1333config MICROCODE_INITRD32
1334	def_bool y
1335	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1336
1337config MICROCODE_LATE_LOADING
1338	bool "Late microcode loading (DANGEROUS)"
1339	default n
1340	depends on MICROCODE && SMP
1341	help
1342	  Loading microcode late, when the system is up and executing instructions
1343	  is a tricky business and should be avoided if possible. Just the sequence
1344	  of synchronizing all cores and SMT threads is one fragile dance which does
1345	  not guarantee that cores might not softlock after the loading. Therefore,
1346	  use this at your own risk. Late loading taints the kernel unless the
1347	  microcode header indicates that it is safe for late loading via the
1348	  minimal revision check. This minimal revision check can be enforced on
1349	  the kernel command line with "microcode.minrev=Y".
1350
1351config MICROCODE_LATE_FORCE_MINREV
1352	bool "Enforce late microcode loading minimal revision check"
1353	default n
1354	depends on MICROCODE_LATE_LOADING
1355	help
1356	  To prevent that users load microcode late which modifies already
1357	  in use features, newer microcode patches have a minimum revision field
1358	  in the microcode header, which tells the kernel which minimum
1359	  revision must be active in the CPU to safely load that new microcode
1360	  late into the running system. If disabled the check will not
1361	  be enforced but the kernel will be tainted when the minimal
1362	  revision check fails.
1363
1364	  This minimal revision check can also be controlled via the
1365	  "microcode.minrev" parameter on the kernel command line.
1366
1367	  If unsure say Y.
1368
1369config X86_MSR
1370	tristate "/dev/cpu/*/msr - Model-specific register support"
1371	help
1372	  This device gives privileged processes access to the x86
1373	  Model-Specific Registers (MSRs).  It is a character device with
1374	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1375	  MSR accesses are directed to a specific CPU on multi-processor
1376	  systems.
1377
1378config X86_CPUID
1379	tristate "/dev/cpu/*/cpuid - CPU information support"
1380	help
1381	  This device gives processes access to the x86 CPUID instruction to
1382	  be executed on a specific processor.  It is a character device
1383	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1384	  /dev/cpu/31/cpuid.
1385
1386choice
1387	prompt "High Memory Support"
1388	default HIGHMEM4G
1389	depends on X86_32
1390
1391config NOHIGHMEM
1392	bool "off"
1393	help
1394	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1395	  However, the address space of 32-bit x86 processors is only 4
1396	  Gigabytes large. That means that, if you have a large amount of
1397	  physical memory, not all of it can be "permanently mapped" by the
1398	  kernel. The physical memory that's not permanently mapped is called
1399	  "high memory".
1400
1401	  If you are compiling a kernel which will never run on a machine with
1402	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1403	  choice and suitable for most users). This will result in a "3GB/1GB"
1404	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1405	  space and the remaining part of the 4GB virtual memory space is used
1406	  by the kernel to permanently map as much physical memory as
1407	  possible.
1408
1409	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1410	  answer "4GB" here.
1411
1412	  If more than 4 Gigabytes is used then answer "64GB" here. This
1413	  selection turns Intel PAE (Physical Address Extension) mode on.
1414	  PAE implements 3-level paging on IA32 processors. PAE is fully
1415	  supported by Linux, PAE mode is implemented on all recent Intel
1416	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1417	  then the kernel will not boot on CPUs that don't support PAE!
1418
1419	  The actual amount of total physical memory will either be
1420	  auto detected or can be forced by using a kernel command line option
1421	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1422	  your boot loader (lilo or loadlin) about how to pass options to the
1423	  kernel at boot time.)
1424
1425	  If unsure, say "off".
1426
1427config HIGHMEM4G
1428	bool "4GB"
1429	help
1430	  Select this if you have a 32-bit processor and between 1 and 4
1431	  gigabytes of physical RAM.
1432
1433config HIGHMEM64G
1434	bool "64GB"
1435	depends on X86_HAVE_PAE
1436	select X86_PAE
1437	help
1438	  Select this if you have a 32-bit processor and more than 4
1439	  gigabytes of physical RAM.
1440
1441endchoice
1442
1443choice
1444	prompt "Memory split" if EXPERT
1445	default VMSPLIT_3G
1446	depends on X86_32
1447	help
1448	  Select the desired split between kernel and user memory.
1449
1450	  If the address range available to the kernel is less than the
1451	  physical memory installed, the remaining memory will be available
1452	  as "high memory". Accessing high memory is a little more costly
1453	  than low memory, as it needs to be mapped into the kernel first.
1454	  Note that increasing the kernel address space limits the range
1455	  available to user programs, making the address space there
1456	  tighter.  Selecting anything other than the default 3G/1G split
1457	  will also likely make your kernel incompatible with binary-only
1458	  kernel modules.
1459
1460	  If you are not absolutely sure what you are doing, leave this
1461	  option alone!
1462
1463	config VMSPLIT_3G
1464		bool "3G/1G user/kernel split"
1465	config VMSPLIT_3G_OPT
1466		depends on !X86_PAE
1467		bool "3G/1G user/kernel split (for full 1G low memory)"
1468	config VMSPLIT_2G
1469		bool "2G/2G user/kernel split"
1470	config VMSPLIT_2G_OPT
1471		depends on !X86_PAE
1472		bool "2G/2G user/kernel split (for full 2G low memory)"
1473	config VMSPLIT_1G
1474		bool "1G/3G user/kernel split"
1475endchoice
1476
1477config PAGE_OFFSET
1478	hex
1479	default 0xB0000000 if VMSPLIT_3G_OPT
1480	default 0x80000000 if VMSPLIT_2G
1481	default 0x78000000 if VMSPLIT_2G_OPT
1482	default 0x40000000 if VMSPLIT_1G
1483	default 0xC0000000
1484	depends on X86_32
1485
1486config HIGHMEM
1487	def_bool y
1488	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1489
1490config X86_PAE
1491	bool "PAE (Physical Address Extension) Support"
1492	depends on X86_32 && X86_HAVE_PAE
1493	select PHYS_ADDR_T_64BIT
1494	select SWIOTLB
1495	help
1496	  PAE is required for NX support, and furthermore enables
1497	  larger swapspace support for non-overcommit purposes. It
1498	  has the cost of more pagetable lookup overhead, and also
1499	  consumes more pagetable space per process.
1500
1501config X86_5LEVEL
1502	bool "Enable 5-level page tables support"
1503	default y
1504	select DYNAMIC_MEMORY_LAYOUT
1505	select SPARSEMEM_VMEMMAP
1506	depends on X86_64
1507	help
1508	  5-level paging enables access to larger address space:
1509	  up to 128 PiB of virtual address space and 4 PiB of
1510	  physical address space.
1511
1512	  It will be supported by future Intel CPUs.
1513
1514	  A kernel with the option enabled can be booted on machines that
1515	  support 4- or 5-level paging.
1516
1517	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1518	  information.
1519
1520	  Say N if unsure.
1521
1522config X86_DIRECT_GBPAGES
1523	def_bool y
1524	depends on X86_64
1525	help
1526	  Certain kernel features effectively disable kernel
1527	  linear 1 GB mappings (even if the CPU otherwise
1528	  supports them), so don't confuse the user by printing
1529	  that we have them enabled.
1530
1531config X86_CPA_STATISTICS
1532	bool "Enable statistic for Change Page Attribute"
1533	depends on DEBUG_FS
1534	help
1535	  Expose statistics about the Change Page Attribute mechanism, which
1536	  helps to determine the effectiveness of preserving large and huge
1537	  page mappings when mapping protections are changed.
1538
1539config X86_MEM_ENCRYPT
1540	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1541	select DYNAMIC_PHYSICAL_MASK
1542	def_bool n
1543
1544config AMD_MEM_ENCRYPT
1545	bool "AMD Secure Memory Encryption (SME) support"
1546	depends on X86_64 && CPU_SUP_AMD
1547	depends on EFI_STUB
1548	select DMA_COHERENT_POOL
1549	select ARCH_USE_MEMREMAP_PROT
1550	select INSTRUCTION_DECODER
1551	select ARCH_HAS_CC_PLATFORM
1552	select X86_MEM_ENCRYPT
1553	select UNACCEPTED_MEMORY
1554	help
1555	  Say yes to enable support for the encryption of system memory.
1556	  This requires an AMD processor that supports Secure Memory
1557	  Encryption (SME).
1558
1559# Common NUMA Features
1560config NUMA
1561	bool "NUMA Memory Allocation and Scheduler Support"
1562	depends on SMP
1563	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1564	default y if X86_BIGSMP
1565	select USE_PERCPU_NUMA_NODE_ID
1566	select OF_NUMA if OF
1567	help
1568	  Enable NUMA (Non-Uniform Memory Access) support.
1569
1570	  The kernel will try to allocate memory used by a CPU on the
1571	  local memory controller of the CPU and add some more
1572	  NUMA awareness to the kernel.
1573
1574	  For 64-bit this is recommended if the system is Intel Core i7
1575	  (or later), AMD Opteron, or EM64T NUMA.
1576
1577	  For 32-bit this is only needed if you boot a 32-bit
1578	  kernel on a 64-bit NUMA platform.
1579
1580	  Otherwise, you should say N.
1581
1582config AMD_NUMA
1583	def_bool y
1584	prompt "Old style AMD Opteron NUMA detection"
1585	depends on X86_64 && NUMA && PCI
1586	help
1587	  Enable AMD NUMA node topology detection.  You should say Y here if
1588	  you have a multi processor AMD system. This uses an old method to
1589	  read the NUMA configuration directly from the builtin Northbridge
1590	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1591	  which also takes priority if both are compiled in.
1592
1593config X86_64_ACPI_NUMA
1594	def_bool y
1595	prompt "ACPI NUMA detection"
1596	depends on X86_64 && NUMA && ACPI && PCI
1597	select ACPI_NUMA
1598	help
1599	  Enable ACPI SRAT based node topology detection.
1600
1601config NUMA_EMU
1602	bool "NUMA emulation"
1603	depends on NUMA
1604	help
1605	  Enable NUMA emulation. A flat machine will be split
1606	  into virtual nodes when booted with "numa=fake=N", where N is the
1607	  number of nodes. This is only useful for debugging.
1608
1609config NODES_SHIFT
1610	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1611	range 1 10
1612	default "10" if MAXSMP
1613	default "6" if X86_64
1614	default "3"
1615	depends on NUMA
1616	help
1617	  Specify the maximum number of NUMA Nodes available on the target
1618	  system.  Increases memory reserved to accommodate various tables.
1619
1620config ARCH_FLATMEM_ENABLE
1621	def_bool y
1622	depends on X86_32 && !NUMA
1623
1624config ARCH_SPARSEMEM_ENABLE
1625	def_bool y
1626	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1627	select SPARSEMEM_STATIC if X86_32
1628	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1629
1630config ARCH_SPARSEMEM_DEFAULT
1631	def_bool X86_64 || (NUMA && X86_32)
1632
1633config ARCH_SELECT_MEMORY_MODEL
1634	def_bool y
1635	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1636
1637config ARCH_MEMORY_PROBE
1638	bool "Enable sysfs memory/probe interface"
1639	depends on MEMORY_HOTPLUG
1640	help
1641	  This option enables a sysfs memory/probe interface for testing.
1642	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1643	  If you are unsure how to answer this question, answer N.
1644
1645config ARCH_PROC_KCORE_TEXT
1646	def_bool y
1647	depends on X86_64 && PROC_KCORE
1648
1649config ILLEGAL_POINTER_VALUE
1650	hex
1651	default 0 if X86_32
1652	default 0xdead000000000000 if X86_64
1653
1654config X86_PMEM_LEGACY_DEVICE
1655	bool
1656
1657config X86_PMEM_LEGACY
1658	tristate "Support non-standard NVDIMMs and ADR protected memory"
1659	depends on PHYS_ADDR_T_64BIT
1660	depends on BLK_DEV
1661	select X86_PMEM_LEGACY_DEVICE
1662	select NUMA_KEEP_MEMINFO if NUMA
1663	select LIBNVDIMM
1664	help
1665	  Treat memory marked using the non-standard e820 type of 12 as used
1666	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1667	  The kernel will offer these regions to the 'pmem' driver so
1668	  they can be used for persistent storage.
1669
1670	  Say Y if unsure.
1671
1672config HIGHPTE
1673	bool "Allocate 3rd-level pagetables from highmem"
1674	depends on HIGHMEM
1675	help
1676	  The VM uses one page table entry for each page of physical memory.
1677	  For systems with a lot of RAM, this can be wasteful of precious
1678	  low memory.  Setting this option will put user-space page table
1679	  entries in high memory.
1680
1681config X86_CHECK_BIOS_CORRUPTION
1682	bool "Check for low memory corruption"
1683	help
1684	  Periodically check for memory corruption in low memory, which
1685	  is suspected to be caused by BIOS.  Even when enabled in the
1686	  configuration, it is disabled at runtime.  Enable it by
1687	  setting "memory_corruption_check=1" on the kernel command
1688	  line.  By default it scans the low 64k of memory every 60
1689	  seconds; see the memory_corruption_check_size and
1690	  memory_corruption_check_period parameters in
1691	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1692
1693	  When enabled with the default parameters, this option has
1694	  almost no overhead, as it reserves a relatively small amount
1695	  of memory and scans it infrequently.  It both detects corruption
1696	  and prevents it from affecting the running system.
1697
1698	  It is, however, intended as a diagnostic tool; if repeatable
1699	  BIOS-originated corruption always affects the same memory,
1700	  you can use memmap= to prevent the kernel from using that
1701	  memory.
1702
1703config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1704	bool "Set the default setting of memory_corruption_check"
1705	depends on X86_CHECK_BIOS_CORRUPTION
1706	default y
1707	help
1708	  Set whether the default state of memory_corruption_check is
1709	  on or off.
1710
1711config MATH_EMULATION
1712	bool
1713	depends on MODIFY_LDT_SYSCALL
1714	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1715	help
1716	  Linux can emulate a math coprocessor (used for floating point
1717	  operations) if you don't have one. 486DX and Pentium processors have
1718	  a math coprocessor built in, 486SX and 386 do not, unless you added
1719	  a 487DX or 387, respectively. (The messages during boot time can
1720	  give you some hints here ["man dmesg"].) Everyone needs either a
1721	  coprocessor or this emulation.
1722
1723	  If you don't have a math coprocessor, you need to say Y here; if you
1724	  say Y here even though you have a coprocessor, the coprocessor will
1725	  be used nevertheless. (This behavior can be changed with the kernel
1726	  command line option "no387", which comes handy if your coprocessor
1727	  is broken. Try "man bootparam" or see the documentation of your boot
1728	  loader (lilo or loadlin) about how to pass options to the kernel at
1729	  boot time.) This means that it is a good idea to say Y here if you
1730	  intend to use this kernel on different machines.
1731
1732	  More information about the internals of the Linux math coprocessor
1733	  emulation can be found in <file:arch/x86/math-emu/README>.
1734
1735	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1736	  kernel, it won't hurt.
1737
1738config MTRR
1739	def_bool y
1740	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1741	help
1742	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1743	  the Memory Type Range Registers (MTRRs) may be used to control
1744	  processor access to memory ranges. This is most useful if you have
1745	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1746	  allows bus write transfers to be combined into a larger transfer
1747	  before bursting over the PCI/AGP bus. This can increase performance
1748	  of image write operations 2.5 times or more. Saying Y here creates a
1749	  /proc/mtrr file which may be used to manipulate your processor's
1750	  MTRRs. Typically the X server should use this.
1751
1752	  This code has a reasonably generic interface so that similar
1753	  control registers on other processors can be easily supported
1754	  as well:
1755
1756	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1757	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1758	  these, the ARRs are used to emulate the MTRRs.
1759	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1760	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1761	  write-combining. All of these processors are supported by this code
1762	  and it makes sense to say Y here if you have one of them.
1763
1764	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1765	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1766	  can lead to all sorts of problems, so it's good to say Y here.
1767
1768	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1769	  just add about 9 KB to your kernel.
1770
1771	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1772
1773config MTRR_SANITIZER
1774	def_bool y
1775	prompt "MTRR cleanup support"
1776	depends on MTRR
1777	help
1778	  Convert MTRR layout from continuous to discrete, so X drivers can
1779	  add writeback entries.
1780
1781	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1782	  The largest mtrr entry size for a continuous block can be set with
1783	  mtrr_chunk_size.
1784
1785	  If unsure, say Y.
1786
1787config MTRR_SANITIZER_ENABLE_DEFAULT
1788	int "MTRR cleanup enable value (0-1)"
1789	range 0 1
1790	default "0"
1791	depends on MTRR_SANITIZER
1792	help
1793	  Enable mtrr cleanup default value
1794
1795config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1796	int "MTRR cleanup spare reg num (0-7)"
1797	range 0 7
1798	default "1"
1799	depends on MTRR_SANITIZER
1800	help
1801	  mtrr cleanup spare entries default, it can be changed via
1802	  mtrr_spare_reg_nr=N on the kernel command line.
1803
1804config X86_PAT
1805	def_bool y
1806	prompt "x86 PAT support" if EXPERT
1807	depends on MTRR
1808	help
1809	  Use PAT attributes to setup page level cache control.
1810
1811	  PATs are the modern equivalents of MTRRs and are much more
1812	  flexible than MTRRs.
1813
1814	  Say N here if you see bootup problems (boot crash, boot hang,
1815	  spontaneous reboots) or a non-working video driver.
1816
1817	  If unsure, say Y.
1818
1819config ARCH_USES_PG_UNCACHED
1820	def_bool y
1821	depends on X86_PAT
1822
1823config X86_UMIP
1824	def_bool y
1825	prompt "User Mode Instruction Prevention" if EXPERT
1826	help
1827	  User Mode Instruction Prevention (UMIP) is a security feature in
1828	  some x86 processors. If enabled, a general protection fault is
1829	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1830	  executed in user mode. These instructions unnecessarily expose
1831	  information about the hardware state.
1832
1833	  The vast majority of applications do not use these instructions.
1834	  For the very few that do, software emulation is provided in
1835	  specific cases in protected and virtual-8086 modes. Emulated
1836	  results are dummy.
1837
1838config CC_HAS_IBT
1839	# GCC >= 9 and binutils >= 2.29
1840	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1841	# Clang/LLVM >= 14
1842	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1843	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1844	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1845		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1846		  $(as-instr,endbr64)
1847
1848config X86_CET
1849	def_bool n
1850	help
1851	  CET features configured (Shadow stack or IBT)
1852
1853config X86_KERNEL_IBT
1854	prompt "Indirect Branch Tracking"
1855	def_bool y
1856	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1857	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1858	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1859	select OBJTOOL
1860	select X86_CET
1861	help
1862	  Build the kernel with support for Indirect Branch Tracking, a
1863	  hardware support course-grain forward-edge Control Flow Integrity
1864	  protection. It enforces that all indirect calls must land on
1865	  an ENDBR instruction, as such, the compiler will instrument the
1866	  code with them to make this happen.
1867
1868	  In addition to building the kernel with IBT, seal all functions that
1869	  are not indirect call targets, avoiding them ever becoming one.
1870
1871	  This requires LTO like objtool runs and will slow down the build. It
1872	  does significantly reduce the number of ENDBR instructions in the
1873	  kernel image.
1874
1875config X86_INTEL_MEMORY_PROTECTION_KEYS
1876	prompt "Memory Protection Keys"
1877	def_bool y
1878	# Note: only available in 64-bit mode
1879	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1880	select ARCH_USES_HIGH_VMA_FLAGS
1881	select ARCH_HAS_PKEYS
1882	help
1883	  Memory Protection Keys provides a mechanism for enforcing
1884	  page-based protections, but without requiring modification of the
1885	  page tables when an application changes protection domains.
1886
1887	  For details, see Documentation/core-api/protection-keys.rst
1888
1889	  If unsure, say y.
1890
1891choice
1892	prompt "TSX enable mode"
1893	depends on CPU_SUP_INTEL
1894	default X86_INTEL_TSX_MODE_OFF
1895	help
1896	  Intel's TSX (Transactional Synchronization Extensions) feature
1897	  allows to optimize locking protocols through lock elision which
1898	  can lead to a noticeable performance boost.
1899
1900	  On the other hand it has been shown that TSX can be exploited
1901	  to form side channel attacks (e.g. TAA) and chances are there
1902	  will be more of those attacks discovered in the future.
1903
1904	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1905	  might override this decision by tsx=on the command line parameter.
1906	  Even with TSX enabled, the kernel will attempt to enable the best
1907	  possible TAA mitigation setting depending on the microcode available
1908	  for the particular machine.
1909
1910	  This option allows to set the default tsx mode between tsx=on, =off
1911	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1912	  details.
1913
1914	  Say off if not sure, auto if TSX is in use but it should be used on safe
1915	  platforms or on if TSX is in use and the security aspect of tsx is not
1916	  relevant.
1917
1918config X86_INTEL_TSX_MODE_OFF
1919	bool "off"
1920	help
1921	  TSX is disabled if possible - equals to tsx=off command line parameter.
1922
1923config X86_INTEL_TSX_MODE_ON
1924	bool "on"
1925	help
1926	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1927	  line parameter.
1928
1929config X86_INTEL_TSX_MODE_AUTO
1930	bool "auto"
1931	help
1932	  TSX is enabled on TSX capable HW that is believed to be safe against
1933	  side channel attacks- equals the tsx=auto command line parameter.
1934endchoice
1935
1936config X86_SGX
1937	bool "Software Guard eXtensions (SGX)"
1938	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1939	depends on CRYPTO=y
1940	depends on CRYPTO_SHA256=y
1941	select MMU_NOTIFIER
1942	select NUMA_KEEP_MEMINFO if NUMA
1943	select XARRAY_MULTI
1944	help
1945	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1946	  that can be used by applications to set aside private regions of code
1947	  and data, referred to as enclaves. An enclave's private memory can
1948	  only be accessed by code running within the enclave. Accesses from
1949	  outside the enclave, including other enclaves, are disallowed by
1950	  hardware.
1951
1952	  If unsure, say N.
1953
1954config X86_USER_SHADOW_STACK
1955	bool "X86 userspace shadow stack"
1956	depends on AS_WRUSS
1957	depends on X86_64
1958	select ARCH_USES_HIGH_VMA_FLAGS
1959	select X86_CET
1960	help
1961	  Shadow stack protection is a hardware feature that detects function
1962	  return address corruption.  This helps mitigate ROP attacks.
1963	  Applications must be enabled to use it, and old userspace does not
1964	  get protection "for free".
1965
1966	  CPUs supporting shadow stacks were first released in 2020.
1967
1968	  See Documentation/arch/x86/shstk.rst for more information.
1969
1970	  If unsure, say N.
1971
1972config INTEL_TDX_HOST
1973	bool "Intel Trust Domain Extensions (TDX) host support"
1974	depends on CPU_SUP_INTEL
1975	depends on X86_64
1976	depends on KVM_INTEL
1977	depends on X86_X2APIC
1978	select ARCH_KEEP_MEMBLOCK
1979	depends on CONTIG_ALLOC
1980	depends on !KEXEC_CORE
1981	depends on X86_MCE
1982	help
1983	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1984	  host and certain physical attacks.  This option enables necessary TDX
1985	  support in the host kernel to run confidential VMs.
1986
1987	  If unsure, say N.
1988
1989config EFI
1990	bool "EFI runtime service support"
1991	depends on ACPI
1992	select UCS2_STRING
1993	select EFI_RUNTIME_WRAPPERS
1994	select ARCH_USE_MEMREMAP_PROT
1995	select EFI_RUNTIME_MAP if KEXEC_CORE
1996	help
1997	  This enables the kernel to use EFI runtime services that are
1998	  available (such as the EFI variable services).
1999
2000	  This option is only useful on systems that have EFI firmware.
2001	  In addition, you should use the latest ELILO loader available
2002	  at <http://elilo.sourceforge.net> in order to take advantage
2003	  of EFI runtime services. However, even with this option, the
2004	  resultant kernel should continue to boot on existing non-EFI
2005	  platforms.
2006
2007config EFI_STUB
2008	bool "EFI stub support"
2009	depends on EFI
2010	select RELOCATABLE
2011	help
2012	  This kernel feature allows a bzImage to be loaded directly
2013	  by EFI firmware without the use of a bootloader.
2014
2015	  See Documentation/admin-guide/efi-stub.rst for more information.
2016
2017config EFI_HANDOVER_PROTOCOL
2018	bool "EFI handover protocol (DEPRECATED)"
2019	depends on EFI_STUB
2020	default y
2021	help
2022	  Select this in order to include support for the deprecated EFI
2023	  handover protocol, which defines alternative entry points into the
2024	  EFI stub.  This is a practice that has no basis in the UEFI
2025	  specification, and requires a priori knowledge on the part of the
2026	  bootloader about Linux/x86 specific ways of passing the command line
2027	  and initrd, and where in memory those assets may be loaded.
2028
2029	  If in doubt, say Y. Even though the corresponding support is not
2030	  present in upstream GRUB or other bootloaders, most distros build
2031	  GRUB with numerous downstream patches applied, and may rely on the
2032	  handover protocol as as result.
2033
2034config EFI_MIXED
2035	bool "EFI mixed-mode support"
2036	depends on EFI_STUB && X86_64
2037	help
2038	  Enabling this feature allows a 64-bit kernel to be booted
2039	  on a 32-bit firmware, provided that your CPU supports 64-bit
2040	  mode.
2041
2042	  Note that it is not possible to boot a mixed-mode enabled
2043	  kernel via the EFI boot stub - a bootloader that supports
2044	  the EFI handover protocol must be used.
2045
2046	  If unsure, say N.
2047
2048config EFI_RUNTIME_MAP
2049	bool "Export EFI runtime maps to sysfs" if EXPERT
2050	depends on EFI
2051	help
2052	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2053	  That memory map is required by the 2nd kernel to set up EFI virtual
2054	  mappings after kexec, but can also be used for debugging purposes.
2055
2056	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2057
2058source "kernel/Kconfig.hz"
2059
2060config ARCH_SUPPORTS_KEXEC
2061	def_bool y
2062
2063config ARCH_SUPPORTS_KEXEC_FILE
2064	def_bool X86_64
2065
2066config ARCH_SELECTS_KEXEC_FILE
2067	def_bool y
2068	depends on KEXEC_FILE
2069	select HAVE_IMA_KEXEC if IMA
2070
2071config ARCH_SUPPORTS_KEXEC_PURGATORY
2072	def_bool y
2073
2074config ARCH_SUPPORTS_KEXEC_SIG
2075	def_bool y
2076
2077config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2078	def_bool y
2079
2080config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2081	def_bool y
2082
2083config ARCH_SUPPORTS_KEXEC_JUMP
2084	def_bool y
2085
2086config ARCH_SUPPORTS_CRASH_DUMP
2087	def_bool X86_64 || (X86_32 && HIGHMEM)
2088
2089config ARCH_SUPPORTS_CRASH_HOTPLUG
2090	def_bool y
2091
2092config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2093	def_bool CRASH_RESERVE
2094
2095config PHYSICAL_START
2096	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2097	default "0x1000000"
2098	help
2099	  This gives the physical address where the kernel is loaded.
2100
2101	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
2102	  will decompress itself to above physical address and run from there.
2103	  Otherwise, bzImage will run from the address where it has been loaded
2104	  by the boot loader. The only exception is if it is loaded below the
2105	  above physical address, in which case it will relocate itself there.
2106
2107	  In normal kdump cases one does not have to set/change this option
2108	  as now bzImage can be compiled as a completely relocatable image
2109	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2110	  address. This option is mainly useful for the folks who don't want
2111	  to use a bzImage for capturing the crash dump and want to use a
2112	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2113	  to be specifically compiled to run from a specific memory area
2114	  (normally a reserved region) and this option comes handy.
2115
2116	  So if you are using bzImage for capturing the crash dump,
2117	  leave the value here unchanged to 0x1000000 and set
2118	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2119	  for capturing the crash dump change this value to start of
2120	  the reserved region.  In other words, it can be set based on
2121	  the "X" value as specified in the "crashkernel=YM@XM"
2122	  command line boot parameter passed to the panic-ed
2123	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2124	  for more details about crash dumps.
2125
2126	  Usage of bzImage for capturing the crash dump is recommended as
2127	  one does not have to build two kernels. Same kernel can be used
2128	  as production kernel and capture kernel. Above option should have
2129	  gone away after relocatable bzImage support is introduced. But it
2130	  is present because there are users out there who continue to use
2131	  vmlinux for dump capture. This option should go away down the
2132	  line.
2133
2134	  Don't change this unless you know what you are doing.
2135
2136config RELOCATABLE
2137	bool "Build a relocatable kernel"
2138	default y
2139	help
2140	  This builds a kernel image that retains relocation information
2141	  so it can be loaded someplace besides the default 1MB.
2142	  The relocations tend to make the kernel binary about 10% larger,
2143	  but are discarded at runtime.
2144
2145	  One use is for the kexec on panic case where the recovery kernel
2146	  must live at a different physical address than the primary
2147	  kernel.
2148
2149	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2150	  it has been loaded at and the compile time physical address
2151	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2152
2153config RANDOMIZE_BASE
2154	bool "Randomize the address of the kernel image (KASLR)"
2155	depends on RELOCATABLE
2156	default y
2157	help
2158	  In support of Kernel Address Space Layout Randomization (KASLR),
2159	  this randomizes the physical address at which the kernel image
2160	  is decompressed and the virtual address where the kernel
2161	  image is mapped, as a security feature that deters exploit
2162	  attempts relying on knowledge of the location of kernel
2163	  code internals.
2164
2165	  On 64-bit, the kernel physical and virtual addresses are
2166	  randomized separately. The physical address will be anywhere
2167	  between 16MB and the top of physical memory (up to 64TB). The
2168	  virtual address will be randomized from 16MB up to 1GB (9 bits
2169	  of entropy). Note that this also reduces the memory space
2170	  available to kernel modules from 1.5GB to 1GB.
2171
2172	  On 32-bit, the kernel physical and virtual addresses are
2173	  randomized together. They will be randomized from 16MB up to
2174	  512MB (8 bits of entropy).
2175
2176	  Entropy is generated using the RDRAND instruction if it is
2177	  supported. If RDTSC is supported, its value is mixed into
2178	  the entropy pool as well. If neither RDRAND nor RDTSC are
2179	  supported, then entropy is read from the i8254 timer. The
2180	  usable entropy is limited by the kernel being built using
2181	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2182	  minimum of 2MB. As a result, only 10 bits of entropy are
2183	  theoretically possible, but the implementations are further
2184	  limited due to memory layouts.
2185
2186	  If unsure, say Y.
2187
2188# Relocation on x86 needs some additional build support
2189config X86_NEED_RELOCS
2190	def_bool y
2191	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2192
2193config PHYSICAL_ALIGN
2194	hex "Alignment value to which kernel should be aligned"
2195	default "0x200000"
2196	range 0x2000 0x1000000 if X86_32
2197	range 0x200000 0x1000000 if X86_64
2198	help
2199	  This value puts the alignment restrictions on physical address
2200	  where kernel is loaded and run from. Kernel is compiled for an
2201	  address which meets above alignment restriction.
2202
2203	  If bootloader loads the kernel at a non-aligned address and
2204	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2205	  address aligned to above value and run from there.
2206
2207	  If bootloader loads the kernel at a non-aligned address and
2208	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2209	  load address and decompress itself to the address it has been
2210	  compiled for and run from there. The address for which kernel is
2211	  compiled already meets above alignment restrictions. Hence the
2212	  end result is that kernel runs from a physical address meeting
2213	  above alignment restrictions.
2214
2215	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2216	  this value must be a multiple of 0x200000.
2217
2218	  Don't change this unless you know what you are doing.
2219
2220config DYNAMIC_MEMORY_LAYOUT
2221	bool
2222	help
2223	  This option makes base addresses of vmalloc and vmemmap as well as
2224	  __PAGE_OFFSET movable during boot.
2225
2226config RANDOMIZE_MEMORY
2227	bool "Randomize the kernel memory sections"
2228	depends on X86_64
2229	depends on RANDOMIZE_BASE
2230	select DYNAMIC_MEMORY_LAYOUT
2231	default RANDOMIZE_BASE
2232	help
2233	  Randomizes the base virtual address of kernel memory sections
2234	  (physical memory mapping, vmalloc & vmemmap). This security feature
2235	  makes exploits relying on predictable memory locations less reliable.
2236
2237	  The order of allocations remains unchanged. Entropy is generated in
2238	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2239	  configuration have in average 30,000 different possible virtual
2240	  addresses for each memory section.
2241
2242	  If unsure, say Y.
2243
2244config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2245	hex "Physical memory mapping padding" if EXPERT
2246	depends on RANDOMIZE_MEMORY
2247	default "0xa" if MEMORY_HOTPLUG
2248	default "0x0"
2249	range 0x1 0x40 if MEMORY_HOTPLUG
2250	range 0x0 0x40
2251	help
2252	  Define the padding in terabytes added to the existing physical
2253	  memory size during kernel memory randomization. It is useful
2254	  for memory hotplug support but reduces the entropy available for
2255	  address randomization.
2256
2257	  If unsure, leave at the default value.
2258
2259config ADDRESS_MASKING
2260	bool "Linear Address Masking support"
2261	depends on X86_64
2262	help
2263	  Linear Address Masking (LAM) modifies the checking that is applied
2264	  to 64-bit linear addresses, allowing software to use of the
2265	  untranslated address bits for metadata.
2266
2267	  The capability can be used for efficient address sanitizers (ASAN)
2268	  implementation and for optimizations in JITs.
2269
2270config HOTPLUG_CPU
2271	def_bool y
2272	depends on SMP
2273
2274config COMPAT_VDSO
2275	def_bool n
2276	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2277	depends on COMPAT_32
2278	help
2279	  Certain buggy versions of glibc will crash if they are
2280	  presented with a 32-bit vDSO that is not mapped at the address
2281	  indicated in its segment table.
2282
2283	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2284	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2285	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2286	  the only released version with the bug, but OpenSUSE 9
2287	  contains a buggy "glibc 2.3.2".
2288
2289	  The symptom of the bug is that everything crashes on startup, saying:
2290	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2291
2292	  Saying Y here changes the default value of the vdso32 boot
2293	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2294	  This works around the glibc bug but hurts performance.
2295
2296	  If unsure, say N: if you are compiling your own kernel, you
2297	  are unlikely to be using a buggy version of glibc.
2298
2299choice
2300	prompt "vsyscall table for legacy applications"
2301	depends on X86_64
2302	default LEGACY_VSYSCALL_XONLY
2303	help
2304	  Legacy user code that does not know how to find the vDSO expects
2305	  to be able to issue three syscalls by calling fixed addresses in
2306	  kernel space. Since this location is not randomized with ASLR,
2307	  it can be used to assist security vulnerability exploitation.
2308
2309	  This setting can be changed at boot time via the kernel command
2310	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2311	  is deprecated and can only be enabled using the kernel command
2312	  line.
2313
2314	  On a system with recent enough glibc (2.14 or newer) and no
2315	  static binaries, you can say None without a performance penalty
2316	  to improve security.
2317
2318	  If unsure, select "Emulate execution only".
2319
2320	config LEGACY_VSYSCALL_XONLY
2321		bool "Emulate execution only"
2322		help
2323		  The kernel traps and emulates calls into the fixed vsyscall
2324		  address mapping and does not allow reads.  This
2325		  configuration is recommended when userspace might use the
2326		  legacy vsyscall area but support for legacy binary
2327		  instrumentation of legacy code is not needed.  It mitigates
2328		  certain uses of the vsyscall area as an ASLR-bypassing
2329		  buffer.
2330
2331	config LEGACY_VSYSCALL_NONE
2332		bool "None"
2333		help
2334		  There will be no vsyscall mapping at all. This will
2335		  eliminate any risk of ASLR bypass due to the vsyscall
2336		  fixed address mapping. Attempts to use the vsyscalls
2337		  will be reported to dmesg, so that either old or
2338		  malicious userspace programs can be identified.
2339
2340endchoice
2341
2342config CMDLINE_BOOL
2343	bool "Built-in kernel command line"
2344	help
2345	  Allow for specifying boot arguments to the kernel at
2346	  build time.  On some systems (e.g. embedded ones), it is
2347	  necessary or convenient to provide some or all of the
2348	  kernel boot arguments with the kernel itself (that is,
2349	  to not rely on the boot loader to provide them.)
2350
2351	  To compile command line arguments into the kernel,
2352	  set this option to 'Y', then fill in the
2353	  boot arguments in CONFIG_CMDLINE.
2354
2355	  Systems with fully functional boot loaders (i.e. non-embedded)
2356	  should leave this option set to 'N'.
2357
2358config CMDLINE
2359	string "Built-in kernel command string"
2360	depends on CMDLINE_BOOL
2361	default ""
2362	help
2363	  Enter arguments here that should be compiled into the kernel
2364	  image and used at boot time.  If the boot loader provides a
2365	  command line at boot time, it is appended to this string to
2366	  form the full kernel command line, when the system boots.
2367
2368	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2369	  change this behavior.
2370
2371	  In most cases, the command line (whether built-in or provided
2372	  by the boot loader) should specify the device for the root
2373	  file system.
2374
2375config CMDLINE_OVERRIDE
2376	bool "Built-in command line overrides boot loader arguments"
2377	depends on CMDLINE_BOOL && CMDLINE != ""
2378	help
2379	  Set this option to 'Y' to have the kernel ignore the boot loader
2380	  command line, and use ONLY the built-in command line.
2381
2382	  This is used to work around broken boot loaders.  This should
2383	  be set to 'N' under normal conditions.
2384
2385config MODIFY_LDT_SYSCALL
2386	bool "Enable the LDT (local descriptor table)" if EXPERT
2387	default y
2388	help
2389	  Linux can allow user programs to install a per-process x86
2390	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2391	  call.  This is required to run 16-bit or segmented code such as
2392	  DOSEMU or some Wine programs.  It is also used by some very old
2393	  threading libraries.
2394
2395	  Enabling this feature adds a small amount of overhead to
2396	  context switches and increases the low-level kernel attack
2397	  surface.  Disabling it removes the modify_ldt(2) system call.
2398
2399	  Saying 'N' here may make sense for embedded or server kernels.
2400
2401config STRICT_SIGALTSTACK_SIZE
2402	bool "Enforce strict size checking for sigaltstack"
2403	depends on DYNAMIC_SIGFRAME
2404	help
2405	  For historical reasons MINSIGSTKSZ is a constant which became
2406	  already too small with AVX512 support. Add a mechanism to
2407	  enforce strict checking of the sigaltstack size against the
2408	  real size of the FPU frame. This option enables the check
2409	  by default. It can also be controlled via the kernel command
2410	  line option 'strict_sas_size' independent of this config
2411	  switch. Enabling it might break existing applications which
2412	  allocate a too small sigaltstack but 'work' because they
2413	  never get a signal delivered.
2414
2415	  Say 'N' unless you want to really enforce this check.
2416
2417config CFI_AUTO_DEFAULT
2418	bool "Attempt to use FineIBT by default at boot time"
2419	depends on FINEIBT
2420	default y
2421	help
2422	  Attempt to use FineIBT by default at boot time. If enabled,
2423	  this is the same as booting with "cfi=auto". If disabled,
2424	  this is the same as booting with "cfi=kcfi".
2425
2426source "kernel/livepatch/Kconfig"
2427
2428endmenu
2429
2430config CC_HAS_NAMED_AS
2431	def_bool CC_IS_GCC && GCC_VERSION >= 90100
2432
2433config CC_HAS_NAMED_AS_FIXED_SANITIZERS
2434	def_bool CC_IS_GCC && GCC_VERSION >= 130300
2435
2436config USE_X86_SEG_SUPPORT
2437	def_bool y
2438	depends on CC_HAS_NAMED_AS
2439	#
2440	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
2441	# (KCSAN) are incompatible with named address spaces with
2442	# GCC < 13.3 - see GCC PR sanitizer/111736.
2443	#
2444	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
2445
2446config CC_HAS_SLS
2447	def_bool $(cc-option,-mharden-sls=all)
2448
2449config CC_HAS_RETURN_THUNK
2450	def_bool $(cc-option,-mfunction-return=thunk-extern)
2451
2452config CC_HAS_ENTRY_PADDING
2453	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2454
2455config FUNCTION_PADDING_CFI
2456	int
2457	default 59 if FUNCTION_ALIGNMENT_64B
2458	default 27 if FUNCTION_ALIGNMENT_32B
2459	default 11 if FUNCTION_ALIGNMENT_16B
2460	default  3 if FUNCTION_ALIGNMENT_8B
2461	default  0
2462
2463# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2464# except Kconfig can't do arithmetic :/
2465config FUNCTION_PADDING_BYTES
2466	int
2467	default FUNCTION_PADDING_CFI if CFI_CLANG
2468	default FUNCTION_ALIGNMENT
2469
2470config CALL_PADDING
2471	def_bool n
2472	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2473	select FUNCTION_ALIGNMENT_16B
2474
2475config FINEIBT
2476	def_bool y
2477	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2478	select CALL_PADDING
2479
2480config HAVE_CALL_THUNKS
2481	def_bool y
2482	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
2483
2484config CALL_THUNKS
2485	def_bool n
2486	select CALL_PADDING
2487
2488config PREFIX_SYMBOLS
2489	def_bool y
2490	depends on CALL_PADDING && !CFI_CLANG
2491
2492menuconfig CPU_MITIGATIONS
2493	bool "Mitigations for CPU vulnerabilities"
2494	default y
2495	help
2496	  Say Y here to enable options which enable mitigations for hardware
2497	  vulnerabilities (usually related to speculative execution).
2498	  Mitigations can be disabled or restricted to SMT systems at runtime
2499	  via the "mitigations" kernel parameter.
2500
2501	  If you say N, all mitigations will be disabled.  This CANNOT be
2502	  overridden at runtime.
2503
2504	  Say 'Y', unless you really know what you are doing.
2505
2506if CPU_MITIGATIONS
2507
2508config MITIGATION_PAGE_TABLE_ISOLATION
2509	bool "Remove the kernel mapping in user mode"
2510	default y
2511	depends on (X86_64 || X86_PAE)
2512	help
2513	  This feature reduces the number of hardware side channels by
2514	  ensuring that the majority of kernel addresses are not mapped
2515	  into userspace.
2516
2517	  See Documentation/arch/x86/pti.rst for more details.
2518
2519config MITIGATION_RETPOLINE
2520	bool "Avoid speculative indirect branches in kernel"
2521	select OBJTOOL if HAVE_OBJTOOL
2522	default y
2523	help
2524	  Compile kernel with the retpoline compiler options to guard against
2525	  kernel-to-user data leaks by avoiding speculative indirect
2526	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2527	  support for full protection. The kernel may run slower.
2528
2529config MITIGATION_RETHUNK
2530	bool "Enable return-thunks"
2531	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2532	select OBJTOOL if HAVE_OBJTOOL
2533	default y if X86_64
2534	help
2535	  Compile the kernel with the return-thunks compiler option to guard
2536	  against kernel-to-user data leaks by avoiding return speculation.
2537	  Requires a compiler with -mfunction-return=thunk-extern
2538	  support for full protection. The kernel may run slower.
2539
2540config MITIGATION_UNRET_ENTRY
2541	bool "Enable UNRET on kernel entry"
2542	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2543	default y
2544	help
2545	  Compile the kernel with support for the retbleed=unret mitigation.
2546
2547config MITIGATION_CALL_DEPTH_TRACKING
2548	bool "Mitigate RSB underflow with call depth tracking"
2549	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2550	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2551	select CALL_THUNKS
2552	default y
2553	help
2554	  Compile the kernel with call depth tracking to mitigate the Intel
2555	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2556	  mitigation is off by default and needs to be enabled on the
2557	  kernel command line via the retbleed=stuff option. For
2558	  non-affected systems the overhead of this option is marginal as
2559	  the call depth tracking is using run-time generated call thunks
2560	  in a compiler generated padding area and call patching. This
2561	  increases text size by ~5%. For non affected systems this space
2562	  is unused. On affected SKL systems this results in a significant
2563	  performance gain over the IBRS mitigation.
2564
2565config CALL_THUNKS_DEBUG
2566	bool "Enable call thunks and call depth tracking debugging"
2567	depends on MITIGATION_CALL_DEPTH_TRACKING
2568	select FUNCTION_ALIGNMENT_32B
2569	default n
2570	help
2571	  Enable call/ret counters for imbalance detection and build in
2572	  a noisy dmesg about callthunks generation and call patching for
2573	  trouble shooting. The debug prints need to be enabled on the
2574	  kernel command line with 'debug-callthunks'.
2575	  Only enable this when you are debugging call thunks as this
2576	  creates a noticeable runtime overhead. If unsure say N.
2577
2578config MITIGATION_IBPB_ENTRY
2579	bool "Enable IBPB on kernel entry"
2580	depends on CPU_SUP_AMD && X86_64
2581	default y
2582	help
2583	  Compile the kernel with support for the retbleed=ibpb mitigation.
2584
2585config MITIGATION_IBRS_ENTRY
2586	bool "Enable IBRS on kernel entry"
2587	depends on CPU_SUP_INTEL && X86_64
2588	default y
2589	help
2590	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2591	  This mitigates both spectre_v2 and retbleed at great cost to
2592	  performance.
2593
2594config MITIGATION_SRSO
2595	bool "Mitigate speculative RAS overflow on AMD"
2596	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2597	default y
2598	help
2599	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2600
2601config MITIGATION_SLS
2602	bool "Mitigate Straight-Line-Speculation"
2603	depends on CC_HAS_SLS && X86_64
2604	select OBJTOOL if HAVE_OBJTOOL
2605	default n
2606	help
2607	  Compile the kernel with straight-line-speculation options to guard
2608	  against straight line speculation. The kernel image might be slightly
2609	  larger.
2610
2611config MITIGATION_GDS_FORCE
2612	bool "Force GDS Mitigation"
2613	depends on CPU_SUP_INTEL
2614	default n
2615	help
2616	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2617	  unprivileged speculative access to data which was previously stored in
2618	  vector registers.
2619
2620	  This option is equivalent to setting gather_data_sampling=force on the
2621	  command line. The microcode mitigation is used if present, otherwise
2622	  AVX is disabled as a mitigation. On affected systems that are missing
2623	  the microcode any userspace code that unconditionally uses AVX will
2624	  break with this option set.
2625
2626	  Setting this option on systems not vulnerable to GDS has no effect.
2627
2628	  If in doubt, say N.
2629
2630config MITIGATION_RFDS
2631	bool "RFDS Mitigation"
2632	depends on CPU_SUP_INTEL
2633	default y
2634	help
2635	  Enable mitigation for Register File Data Sampling (RFDS) by default.
2636	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
2637	  allows unprivileged speculative access to stale data previously
2638	  stored in floating point, vector and integer registers.
2639	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
2640
2641config MITIGATION_SPECTRE_BHI
2642	bool "Mitigate Spectre-BHB (Branch History Injection)"
2643	depends on CPU_SUP_INTEL
2644	default y
2645	help
2646	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2647	  where the branch history buffer is poisoned to speculatively steer
2648	  indirect branches.
2649	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2650
2651endif
2652
2653config ARCH_HAS_ADD_PAGES
2654	def_bool y
2655	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2656
2657menu "Power management and ACPI options"
2658
2659config ARCH_HIBERNATION_HEADER
2660	def_bool y
2661	depends on HIBERNATION
2662
2663source "kernel/power/Kconfig"
2664
2665source "drivers/acpi/Kconfig"
2666
2667config X86_APM_BOOT
2668	def_bool y
2669	depends on APM
2670
2671menuconfig APM
2672	tristate "APM (Advanced Power Management) BIOS support"
2673	depends on X86_32 && PM_SLEEP
2674	help
2675	  APM is a BIOS specification for saving power using several different
2676	  techniques. This is mostly useful for battery powered laptops with
2677	  APM compliant BIOSes. If you say Y here, the system time will be
2678	  reset after a RESUME operation, the /proc/apm device will provide
2679	  battery status information, and user-space programs will receive
2680	  notification of APM "events" (e.g. battery status change).
2681
2682	  If you select "Y" here, you can disable actual use of the APM
2683	  BIOS by passing the "apm=off" option to the kernel at boot time.
2684
2685	  Note that the APM support is almost completely disabled for
2686	  machines with more than one CPU.
2687
2688	  In order to use APM, you will need supporting software. For location
2689	  and more information, read <file:Documentation/power/apm-acpi.rst>
2690	  and the Battery Powered Linux mini-HOWTO, available from
2691	  <http://www.tldp.org/docs.html#howto>.
2692
2693	  This driver does not spin down disk drives (see the hdparm(8)
2694	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2695	  VESA-compliant "green" monitors.
2696
2697	  This driver does not support the TI 4000M TravelMate and the ACER
2698	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2699	  desktop machines also don't have compliant BIOSes, and this driver
2700	  may cause those machines to panic during the boot phase.
2701
2702	  Generally, if you don't have a battery in your machine, there isn't
2703	  much point in using this driver and you should say N. If you get
2704	  random kernel OOPSes or reboots that don't seem to be related to
2705	  anything, try disabling/enabling this option (or disabling/enabling
2706	  APM in your BIOS).
2707
2708	  Some other things you should try when experiencing seemingly random,
2709	  "weird" problems:
2710
2711	  1) make sure that you have enough swap space and that it is
2712	  enabled.
2713	  2) pass the "idle=poll" option to the kernel
2714	  3) switch on floating point emulation in the kernel and pass
2715	  the "no387" option to the kernel
2716	  4) pass the "floppy=nodma" option to the kernel
2717	  5) pass the "mem=4M" option to the kernel (thereby disabling
2718	  all but the first 4 MB of RAM)
2719	  6) make sure that the CPU is not over clocked.
2720	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2721	  8) disable the cache from your BIOS settings
2722	  9) install a fan for the video card or exchange video RAM
2723	  10) install a better fan for the CPU
2724	  11) exchange RAM chips
2725	  12) exchange the motherboard.
2726
2727	  To compile this driver as a module, choose M here: the
2728	  module will be called apm.
2729
2730if APM
2731
2732config APM_IGNORE_USER_SUSPEND
2733	bool "Ignore USER SUSPEND"
2734	help
2735	  This option will ignore USER SUSPEND requests. On machines with a
2736	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2737	  series notebooks, it is necessary to say Y because of a BIOS bug.
2738
2739config APM_DO_ENABLE
2740	bool "Enable PM at boot time"
2741	help
2742	  Enable APM features at boot time. From page 36 of the APM BIOS
2743	  specification: "When disabled, the APM BIOS does not automatically
2744	  power manage devices, enter the Standby State, enter the Suspend
2745	  State, or take power saving steps in response to CPU Idle calls."
2746	  This driver will make CPU Idle calls when Linux is idle (unless this
2747	  feature is turned off -- see "Do CPU IDLE calls", below). This
2748	  should always save battery power, but more complicated APM features
2749	  will be dependent on your BIOS implementation. You may need to turn
2750	  this option off if your computer hangs at boot time when using APM
2751	  support, or if it beeps continuously instead of suspending. Turn
2752	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2753	  T400CDT. This is off by default since most machines do fine without
2754	  this feature.
2755
2756config APM_CPU_IDLE
2757	depends on CPU_IDLE
2758	bool "Make CPU Idle calls when idle"
2759	help
2760	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2761	  On some machines, this can activate improved power savings, such as
2762	  a slowed CPU clock rate, when the machine is idle. These idle calls
2763	  are made after the idle loop has run for some length of time (e.g.,
2764	  333 mS). On some machines, this will cause a hang at boot time or
2765	  whenever the CPU becomes idle. (On machines with more than one CPU,
2766	  this option does nothing.)
2767
2768config APM_DISPLAY_BLANK
2769	bool "Enable console blanking using APM"
2770	help
2771	  Enable console blanking using the APM. Some laptops can use this to
2772	  turn off the LCD backlight when the screen blanker of the Linux
2773	  virtual console blanks the screen. Note that this is only used by
2774	  the virtual console screen blanker, and won't turn off the backlight
2775	  when using the X Window system. This also doesn't have anything to
2776	  do with your VESA-compliant power-saving monitor. Further, this
2777	  option doesn't work for all laptops -- it might not turn off your
2778	  backlight at all, or it might print a lot of errors to the console,
2779	  especially if you are using gpm.
2780
2781config APM_ALLOW_INTS
2782	bool "Allow interrupts during APM BIOS calls"
2783	help
2784	  Normally we disable external interrupts while we are making calls to
2785	  the APM BIOS as a measure to lessen the effects of a badly behaving
2786	  BIOS implementation.  The BIOS should reenable interrupts if it
2787	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2788	  many of the newer IBM Thinkpads.  If you experience hangs when you
2789	  suspend, try setting this to Y.  Otherwise, say N.
2790
2791endif # APM
2792
2793source "drivers/cpufreq/Kconfig"
2794
2795source "drivers/cpuidle/Kconfig"
2796
2797source "drivers/idle/Kconfig"
2798
2799endmenu
2800
2801menu "Bus options (PCI etc.)"
2802
2803choice
2804	prompt "PCI access mode"
2805	depends on X86_32 && PCI
2806	default PCI_GOANY
2807	help
2808	  On PCI systems, the BIOS can be used to detect the PCI devices and
2809	  determine their configuration. However, some old PCI motherboards
2810	  have BIOS bugs and may crash if this is done. Also, some embedded
2811	  PCI-based systems don't have any BIOS at all. Linux can also try to
2812	  detect the PCI hardware directly without using the BIOS.
2813
2814	  With this option, you can specify how Linux should detect the
2815	  PCI devices. If you choose "BIOS", the BIOS will be used,
2816	  if you choose "Direct", the BIOS won't be used, and if you
2817	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2818	  If you choose "Any", the kernel will try MMCONFIG, then the
2819	  direct access method and falls back to the BIOS if that doesn't
2820	  work. If unsure, go with the default, which is "Any".
2821
2822config PCI_GOBIOS
2823	bool "BIOS"
2824
2825config PCI_GOMMCONFIG
2826	bool "MMConfig"
2827
2828config PCI_GODIRECT
2829	bool "Direct"
2830
2831config PCI_GOOLPC
2832	bool "OLPC XO-1"
2833	depends on OLPC
2834
2835config PCI_GOANY
2836	bool "Any"
2837
2838endchoice
2839
2840config PCI_BIOS
2841	def_bool y
2842	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2843
2844# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2845config PCI_DIRECT
2846	def_bool y
2847	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2848
2849config PCI_MMCONFIG
2850	bool "Support mmconfig PCI config space access" if X86_64
2851	default y
2852	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2853	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2854
2855config PCI_OLPC
2856	def_bool y
2857	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2858
2859config PCI_XEN
2860	def_bool y
2861	depends on PCI && XEN
2862
2863config MMCONF_FAM10H
2864	def_bool y
2865	depends on X86_64 && PCI_MMCONFIG && ACPI
2866
2867config PCI_CNB20LE_QUIRK
2868	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2869	depends on PCI
2870	help
2871	  Read the PCI windows out of the CNB20LE host bridge. This allows
2872	  PCI hotplug to work on systems with the CNB20LE chipset which do
2873	  not have ACPI.
2874
2875	  There's no public spec for this chipset, and this functionality
2876	  is known to be incomplete.
2877
2878	  You should say N unless you know you need this.
2879
2880config ISA_BUS
2881	bool "ISA bus support on modern systems" if EXPERT
2882	help
2883	  Expose ISA bus device drivers and options available for selection and
2884	  configuration. Enable this option if your target machine has an ISA
2885	  bus. ISA is an older system, displaced by PCI and newer bus
2886	  architectures -- if your target machine is modern, it probably does
2887	  not have an ISA bus.
2888
2889	  If unsure, say N.
2890
2891# x86_64 have no ISA slots, but can have ISA-style DMA.
2892config ISA_DMA_API
2893	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2894	default y
2895	help
2896	  Enables ISA-style DMA support for devices requiring such controllers.
2897	  If unsure, say Y.
2898
2899if X86_32
2900
2901config ISA
2902	bool "ISA support"
2903	help
2904	  Find out whether you have ISA slots on your motherboard.  ISA is the
2905	  name of a bus system, i.e. the way the CPU talks to the other stuff
2906	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2907	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2908	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2909
2910config SCx200
2911	tristate "NatSemi SCx200 support"
2912	help
2913	  This provides basic support for National Semiconductor's
2914	  (now AMD's) Geode processors.  The driver probes for the
2915	  PCI-IDs of several on-chip devices, so its a good dependency
2916	  for other scx200_* drivers.
2917
2918	  If compiled as a module, the driver is named scx200.
2919
2920config SCx200HR_TIMER
2921	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2922	depends on SCx200
2923	default y
2924	help
2925	  This driver provides a clocksource built upon the on-chip
2926	  27MHz high-resolution timer.  Its also a workaround for
2927	  NSC Geode SC-1100's buggy TSC, which loses time when the
2928	  processor goes idle (as is done by the scheduler).  The
2929	  other workaround is idle=poll boot option.
2930
2931config OLPC
2932	bool "One Laptop Per Child support"
2933	depends on !X86_PAE
2934	select GPIOLIB
2935	select OF
2936	select OF_PROMTREE
2937	select IRQ_DOMAIN
2938	select OLPC_EC
2939	help
2940	  Add support for detecting the unique features of the OLPC
2941	  XO hardware.
2942
2943config OLPC_XO1_PM
2944	bool "OLPC XO-1 Power Management"
2945	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2946	help
2947	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2948
2949config OLPC_XO1_RTC
2950	bool "OLPC XO-1 Real Time Clock"
2951	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2952	help
2953	  Add support for the XO-1 real time clock, which can be used as a
2954	  programmable wakeup source.
2955
2956config OLPC_XO1_SCI
2957	bool "OLPC XO-1 SCI extras"
2958	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2959	depends on INPUT=y
2960	select POWER_SUPPLY
2961	help
2962	  Add support for SCI-based features of the OLPC XO-1 laptop:
2963	   - EC-driven system wakeups
2964	   - Power button
2965	   - Ebook switch
2966	   - Lid switch
2967	   - AC adapter status updates
2968	   - Battery status updates
2969
2970config OLPC_XO15_SCI
2971	bool "OLPC XO-1.5 SCI extras"
2972	depends on OLPC && ACPI
2973	select POWER_SUPPLY
2974	help
2975	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2976	   - EC-driven system wakeups
2977	   - AC adapter status updates
2978	   - Battery status updates
2979
2980config ALIX
2981	bool "PCEngines ALIX System Support (LED setup)"
2982	select GPIOLIB
2983	help
2984	  This option enables system support for the PCEngines ALIX.
2985	  At present this just sets up LEDs for GPIO control on
2986	  ALIX2/3/6 boards.  However, other system specific setup should
2987	  get added here.
2988
2989	  Note: You must still enable the drivers for GPIO and LED support
2990	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2991
2992	  Note: You have to set alix.force=1 for boards with Award BIOS.
2993
2994config NET5501
2995	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2996	select GPIOLIB
2997	help
2998	  This option enables system support for the Soekris Engineering net5501.
2999
3000config GEOS
3001	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
3002	select GPIOLIB
3003	depends on DMI
3004	help
3005	  This option enables system support for the Traverse Technologies GEOS.
3006
3007config TS5500
3008	bool "Technologic Systems TS-5500 platform support"
3009	depends on MELAN
3010	select CHECK_SIGNATURE
3011	select NEW_LEDS
3012	select LEDS_CLASS
3013	help
3014	  This option enables system support for the Technologic Systems TS-5500.
3015
3016endif # X86_32
3017
3018config AMD_NB
3019	def_bool y
3020	depends on CPU_SUP_AMD && PCI
3021
3022endmenu
3023
3024menu "Binary Emulations"
3025
3026config IA32_EMULATION
3027	bool "IA32 Emulation"
3028	depends on X86_64
3029	select ARCH_WANT_OLD_COMPAT_IPC
3030	select BINFMT_ELF
3031	select COMPAT_OLD_SIGACTION
3032	help
3033	  Include code to run legacy 32-bit programs under a
3034	  64-bit kernel. You should likely turn this on, unless you're
3035	  100% sure that you don't have any 32-bit programs left.
3036
3037config IA32_EMULATION_DEFAULT_DISABLED
3038	bool "IA32 emulation disabled by default"
3039	default n
3040	depends on IA32_EMULATION
3041	help
3042	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3043	  processes and access to 32-bit syscalls. If unsure, leave it to its
3044	  default value.
3045
3046config X86_X32_ABI
3047	bool "x32 ABI for 64-bit mode"
3048	depends on X86_64
3049	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3050	# compressed debug sections to x86_x32 properly:
3051	# https://github.com/ClangBuiltLinux/linux/issues/514
3052	# https://github.com/ClangBuiltLinux/linux/issues/1141
3053	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3054	help
3055	  Include code to run binaries for the x32 native 32-bit ABI
3056	  for 64-bit processors.  An x32 process gets access to the
3057	  full 64-bit register file and wide data path while leaving
3058	  pointers at 32 bits for smaller memory footprint.
3059
3060config COMPAT_32
3061	def_bool y
3062	depends on IA32_EMULATION || X86_32
3063	select HAVE_UID16
3064	select OLD_SIGSUSPEND3
3065
3066config COMPAT
3067	def_bool y
3068	depends on IA32_EMULATION || X86_X32_ABI
3069
3070config COMPAT_FOR_U64_ALIGNMENT
3071	def_bool y
3072	depends on COMPAT
3073
3074endmenu
3075
3076config HAVE_ATOMIC_IOMAP
3077	def_bool y
3078	depends on X86_32
3079
3080source "arch/x86/kvm/Kconfig"
3081
3082source "arch/x86/Kconfig.assembler"
3083