xref: /linux/arch/x86/Kconfig (revision 95444b9eeb8c5c0330563931d70c61ca3b101548)
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 X86_IO_APIC
1122	def_bool y
1123	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1124
1125config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1126	bool "Reroute for broken boot IRQs"
1127	depends on X86_IO_APIC
1128	help
1129	  This option enables a workaround that fixes a source of
1130	  spurious interrupts. This is recommended when threaded
1131	  interrupt handling is used on systems where the generation of
1132	  superfluous "boot interrupts" cannot be disabled.
1133
1134	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1135	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1136	  kernel does during interrupt handling). On chipsets where this
1137	  boot IRQ generation cannot be disabled, this workaround keeps
1138	  the original IRQ line masked so that only the equivalent "boot
1139	  IRQ" is delivered to the CPUs. The workaround also tells the
1140	  kernel to set up the IRQ handler on the boot IRQ line. In this
1141	  way only one interrupt is delivered to the kernel. Otherwise
1142	  the spurious second interrupt may cause the kernel to bring
1143	  down (vital) interrupt lines.
1144
1145	  Only affects "broken" chipsets. Interrupt sharing may be
1146	  increased on these systems.
1147
1148config X86_MCE
1149	bool "Machine Check / overheating reporting"
1150	select GENERIC_ALLOCATOR
1151	default y
1152	help
1153	  Machine Check support allows the processor to notify the
1154	  kernel if it detects a problem (e.g. overheating, data corruption).
1155	  The action the kernel takes depends on the severity of the problem,
1156	  ranging from warning messages to halting the machine.
1157
1158config X86_MCELOG_LEGACY
1159	bool "Support for deprecated /dev/mcelog character device"
1160	depends on X86_MCE
1161	help
1162	  Enable support for /dev/mcelog which is needed by the old mcelog
1163	  userspace logging daemon. Consider switching to the new generation
1164	  rasdaemon solution.
1165
1166config X86_MCE_INTEL
1167	def_bool y
1168	prompt "Intel MCE features"
1169	depends on X86_MCE && X86_LOCAL_APIC
1170	help
1171	  Additional support for intel specific MCE features such as
1172	  the thermal monitor.
1173
1174config X86_MCE_AMD
1175	def_bool y
1176	prompt "AMD MCE features"
1177	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1178	help
1179	  Additional support for AMD specific MCE features such as
1180	  the DRAM Error Threshold.
1181
1182config X86_ANCIENT_MCE
1183	bool "Support for old Pentium 5 / WinChip machine checks"
1184	depends on X86_32 && X86_MCE
1185	help
1186	  Include support for machine check handling on old Pentium 5 or WinChip
1187	  systems. These typically need to be enabled explicitly on the command
1188	  line.
1189
1190config X86_MCE_THRESHOLD
1191	depends on X86_MCE_AMD || X86_MCE_INTEL
1192	def_bool y
1193
1194config X86_MCE_INJECT
1195	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1196	tristate "Machine check injector support"
1197	help
1198	  Provide support for injecting machine checks for testing purposes.
1199	  If you don't know what a machine check is and you don't do kernel
1200	  QA it is safe to say n.
1201
1202source "arch/x86/events/Kconfig"
1203
1204config X86_LEGACY_VM86
1205	bool "Legacy VM86 support"
1206	depends on X86_32
1207	help
1208	  This option allows user programs to put the CPU into V8086
1209	  mode, which is an 80286-era approximation of 16-bit real mode.
1210
1211	  Some very old versions of X and/or vbetool require this option
1212	  for user mode setting.  Similarly, DOSEMU will use it if
1213	  available to accelerate real mode DOS programs.  However, any
1214	  recent version of DOSEMU, X, or vbetool should be fully
1215	  functional even without kernel VM86 support, as they will all
1216	  fall back to software emulation. Nevertheless, if you are using
1217	  a 16-bit DOS program where 16-bit performance matters, vm86
1218	  mode might be faster than emulation and you might want to
1219	  enable this option.
1220
1221	  Note that any app that works on a 64-bit kernel is unlikely to
1222	  need this option, as 64-bit kernels don't, and can't, support
1223	  V8086 mode. This option is also unrelated to 16-bit protected
1224	  mode and is not needed to run most 16-bit programs under Wine.
1225
1226	  Enabling this option increases the complexity of the kernel
1227	  and slows down exception handling a tiny bit.
1228
1229	  If unsure, say N here.
1230
1231config VM86
1232	bool
1233	default X86_LEGACY_VM86
1234
1235config X86_16BIT
1236	bool "Enable support for 16-bit segments" if EXPERT
1237	default y
1238	depends on MODIFY_LDT_SYSCALL
1239	help
1240	  This option is required by programs like Wine to run 16-bit
1241	  protected mode legacy code on x86 processors.  Disabling
1242	  this option saves about 300 bytes on i386, or around 6K text
1243	  plus 16K runtime memory on x86-64,
1244
1245config X86_ESPFIX32
1246	def_bool y
1247	depends on X86_16BIT && X86_32
1248
1249config X86_ESPFIX64
1250	def_bool y
1251	depends on X86_16BIT && X86_64
1252
1253config X86_VSYSCALL_EMULATION
1254	bool "Enable vsyscall emulation" if EXPERT
1255	default y
1256	depends on X86_64
1257	help
1258	  This enables emulation of the legacy vsyscall page.  Disabling
1259	  it is roughly equivalent to booting with vsyscall=none, except
1260	  that it will also disable the helpful warning if a program
1261	  tries to use a vsyscall.  With this option set to N, offending
1262	  programs will just segfault, citing addresses of the form
1263	  0xffffffffff600?00.
1264
1265	  This option is required by many programs built before 2013, and
1266	  care should be used even with newer programs if set to N.
1267
1268	  Disabling this option saves about 7K of kernel size and
1269	  possibly 4K of additional runtime pagetable memory.
1270
1271config X86_IOPL_IOPERM
1272	bool "IOPERM and IOPL Emulation"
1273	default y
1274	help
1275	  This enables the ioperm() and iopl() syscalls which are necessary
1276	  for legacy applications.
1277
1278	  Legacy IOPL support is an overbroad mechanism which allows user
1279	  space aside of accessing all 65536 I/O ports also to disable
1280	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1281	  capabilities and permission from potentially active security
1282	  modules.
1283
1284	  The emulation restricts the functionality of the syscall to
1285	  only allowing the full range I/O port access, but prevents the
1286	  ability to disable interrupts from user space which would be
1287	  granted if the hardware IOPL mechanism would be used.
1288
1289config TOSHIBA
1290	tristate "Toshiba Laptop support"
1291	depends on X86_32
1292	help
1293	  This adds a driver to safely access the System Management Mode of
1294	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1295	  not work on models with a Phoenix BIOS. The System Management Mode
1296	  is used to set the BIOS and power saving options on Toshiba portables.
1297
1298	  For information on utilities to make use of this driver see the
1299	  Toshiba Linux utilities web site at:
1300	  <http://www.buzzard.org.uk/toshiba/>.
1301
1302	  Say Y if you intend to run this kernel on a Toshiba portable.
1303	  Say N otherwise.
1304
1305config X86_REBOOTFIXUPS
1306	bool "Enable X86 board specific fixups for reboot"
1307	depends on X86_32
1308	help
1309	  This enables chipset and/or board specific fixups to be done
1310	  in order to get reboot to work correctly. This is only needed on
1311	  some combinations of hardware and BIOS. The symptom, for which
1312	  this config is intended, is when reboot ends with a stalled/hung
1313	  system.
1314
1315	  Currently, the only fixup is for the Geode machines using
1316	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1317
1318	  Say Y if you want to enable the fixup. Currently, it's safe to
1319	  enable this option even if you don't need it.
1320	  Say N otherwise.
1321
1322config MICROCODE
1323	def_bool y
1324	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1325
1326config MICROCODE_INITRD32
1327	def_bool y
1328	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1329
1330config MICROCODE_LATE_LOADING
1331	bool "Late microcode loading (DANGEROUS)"
1332	default n
1333	depends on MICROCODE && SMP
1334	help
1335	  Loading microcode late, when the system is up and executing instructions
1336	  is a tricky business and should be avoided if possible. Just the sequence
1337	  of synchronizing all cores and SMT threads is one fragile dance which does
1338	  not guarantee that cores might not softlock after the loading. Therefore,
1339	  use this at your own risk. Late loading taints the kernel unless the
1340	  microcode header indicates that it is safe for late loading via the
1341	  minimal revision check. This minimal revision check can be enforced on
1342	  the kernel command line with "microcode.minrev=Y".
1343
1344config MICROCODE_LATE_FORCE_MINREV
1345	bool "Enforce late microcode loading minimal revision check"
1346	default n
1347	depends on MICROCODE_LATE_LOADING
1348	help
1349	  To prevent that users load microcode late which modifies already
1350	  in use features, newer microcode patches have a minimum revision field
1351	  in the microcode header, which tells the kernel which minimum
1352	  revision must be active in the CPU to safely load that new microcode
1353	  late into the running system. If disabled the check will not
1354	  be enforced but the kernel will be tainted when the minimal
1355	  revision check fails.
1356
1357	  This minimal revision check can also be controlled via the
1358	  "microcode.minrev" parameter on the kernel command line.
1359
1360	  If unsure say Y.
1361
1362config X86_MSR
1363	tristate "/dev/cpu/*/msr - Model-specific register support"
1364	help
1365	  This device gives privileged processes access to the x86
1366	  Model-Specific Registers (MSRs).  It is a character device with
1367	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1368	  MSR accesses are directed to a specific CPU on multi-processor
1369	  systems.
1370
1371config X86_CPUID
1372	tristate "/dev/cpu/*/cpuid - CPU information support"
1373	help
1374	  This device gives processes access to the x86 CPUID instruction to
1375	  be executed on a specific processor.  It is a character device
1376	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1377	  /dev/cpu/31/cpuid.
1378
1379choice
1380	prompt "High Memory Support"
1381	default HIGHMEM4G
1382	depends on X86_32
1383
1384config NOHIGHMEM
1385	bool "off"
1386	help
1387	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1388	  However, the address space of 32-bit x86 processors is only 4
1389	  Gigabytes large. That means that, if you have a large amount of
1390	  physical memory, not all of it can be "permanently mapped" by the
1391	  kernel. The physical memory that's not permanently mapped is called
1392	  "high memory".
1393
1394	  If you are compiling a kernel which will never run on a machine with
1395	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1396	  choice and suitable for most users). This will result in a "3GB/1GB"
1397	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1398	  space and the remaining part of the 4GB virtual memory space is used
1399	  by the kernel to permanently map as much physical memory as
1400	  possible.
1401
1402	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1403	  answer "4GB" here.
1404
1405	  If more than 4 Gigabytes is used then answer "64GB" here. This
1406	  selection turns Intel PAE (Physical Address Extension) mode on.
1407	  PAE implements 3-level paging on IA32 processors. PAE is fully
1408	  supported by Linux, PAE mode is implemented on all recent Intel
1409	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1410	  then the kernel will not boot on CPUs that don't support PAE!
1411
1412	  The actual amount of total physical memory will either be
1413	  auto detected or can be forced by using a kernel command line option
1414	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1415	  your boot loader (lilo or loadlin) about how to pass options to the
1416	  kernel at boot time.)
1417
1418	  If unsure, say "off".
1419
1420config HIGHMEM4G
1421	bool "4GB"
1422	help
1423	  Select this if you have a 32-bit processor and between 1 and 4
1424	  gigabytes of physical RAM.
1425
1426config HIGHMEM64G
1427	bool "64GB"
1428	depends on X86_HAVE_PAE
1429	select X86_PAE
1430	help
1431	  Select this if you have a 32-bit processor and more than 4
1432	  gigabytes of physical RAM.
1433
1434endchoice
1435
1436choice
1437	prompt "Memory split" if EXPERT
1438	default VMSPLIT_3G
1439	depends on X86_32
1440	help
1441	  Select the desired split between kernel and user memory.
1442
1443	  If the address range available to the kernel is less than the
1444	  physical memory installed, the remaining memory will be available
1445	  as "high memory". Accessing high memory is a little more costly
1446	  than low memory, as it needs to be mapped into the kernel first.
1447	  Note that increasing the kernel address space limits the range
1448	  available to user programs, making the address space there
1449	  tighter.  Selecting anything other than the default 3G/1G split
1450	  will also likely make your kernel incompatible with binary-only
1451	  kernel modules.
1452
1453	  If you are not absolutely sure what you are doing, leave this
1454	  option alone!
1455
1456	config VMSPLIT_3G
1457		bool "3G/1G user/kernel split"
1458	config VMSPLIT_3G_OPT
1459		depends on !X86_PAE
1460		bool "3G/1G user/kernel split (for full 1G low memory)"
1461	config VMSPLIT_2G
1462		bool "2G/2G user/kernel split"
1463	config VMSPLIT_2G_OPT
1464		depends on !X86_PAE
1465		bool "2G/2G user/kernel split (for full 2G low memory)"
1466	config VMSPLIT_1G
1467		bool "1G/3G user/kernel split"
1468endchoice
1469
1470config PAGE_OFFSET
1471	hex
1472	default 0xB0000000 if VMSPLIT_3G_OPT
1473	default 0x80000000 if VMSPLIT_2G
1474	default 0x78000000 if VMSPLIT_2G_OPT
1475	default 0x40000000 if VMSPLIT_1G
1476	default 0xC0000000
1477	depends on X86_32
1478
1479config HIGHMEM
1480	def_bool y
1481	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1482
1483config X86_PAE
1484	bool "PAE (Physical Address Extension) Support"
1485	depends on X86_32 && X86_HAVE_PAE
1486	select PHYS_ADDR_T_64BIT
1487	select SWIOTLB
1488	help
1489	  PAE is required for NX support, and furthermore enables
1490	  larger swapspace support for non-overcommit purposes. It
1491	  has the cost of more pagetable lookup overhead, and also
1492	  consumes more pagetable space per process.
1493
1494config X86_5LEVEL
1495	bool "Enable 5-level page tables support"
1496	default y
1497	select DYNAMIC_MEMORY_LAYOUT
1498	select SPARSEMEM_VMEMMAP
1499	depends on X86_64
1500	help
1501	  5-level paging enables access to larger address space:
1502	  up to 128 PiB of virtual address space and 4 PiB of
1503	  physical address space.
1504
1505	  It will be supported by future Intel CPUs.
1506
1507	  A kernel with the option enabled can be booted on machines that
1508	  support 4- or 5-level paging.
1509
1510	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1511	  information.
1512
1513	  Say N if unsure.
1514
1515config X86_DIRECT_GBPAGES
1516	def_bool y
1517	depends on X86_64
1518	help
1519	  Certain kernel features effectively disable kernel
1520	  linear 1 GB mappings (even if the CPU otherwise
1521	  supports them), so don't confuse the user by printing
1522	  that we have them enabled.
1523
1524config X86_CPA_STATISTICS
1525	bool "Enable statistic for Change Page Attribute"
1526	depends on DEBUG_FS
1527	help
1528	  Expose statistics about the Change Page Attribute mechanism, which
1529	  helps to determine the effectiveness of preserving large and huge
1530	  page mappings when mapping protections are changed.
1531
1532config X86_MEM_ENCRYPT
1533	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1534	select DYNAMIC_PHYSICAL_MASK
1535	def_bool n
1536
1537config AMD_MEM_ENCRYPT
1538	bool "AMD Secure Memory Encryption (SME) support"
1539	depends on X86_64 && CPU_SUP_AMD
1540	depends on EFI_STUB
1541	select DMA_COHERENT_POOL
1542	select ARCH_USE_MEMREMAP_PROT
1543	select INSTRUCTION_DECODER
1544	select ARCH_HAS_CC_PLATFORM
1545	select X86_MEM_ENCRYPT
1546	select UNACCEPTED_MEMORY
1547	help
1548	  Say yes to enable support for the encryption of system memory.
1549	  This requires an AMD processor that supports Secure Memory
1550	  Encryption (SME).
1551
1552# Common NUMA Features
1553config NUMA
1554	bool "NUMA Memory Allocation and Scheduler Support"
1555	depends on SMP
1556	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1557	default y if X86_BIGSMP
1558	select USE_PERCPU_NUMA_NODE_ID
1559	select OF_NUMA if OF
1560	help
1561	  Enable NUMA (Non-Uniform Memory Access) support.
1562
1563	  The kernel will try to allocate memory used by a CPU on the
1564	  local memory controller of the CPU and add some more
1565	  NUMA awareness to the kernel.
1566
1567	  For 64-bit this is recommended if the system is Intel Core i7
1568	  (or later), AMD Opteron, or EM64T NUMA.
1569
1570	  For 32-bit this is only needed if you boot a 32-bit
1571	  kernel on a 64-bit NUMA platform.
1572
1573	  Otherwise, you should say N.
1574
1575config AMD_NUMA
1576	def_bool y
1577	prompt "Old style AMD Opteron NUMA detection"
1578	depends on X86_64 && NUMA && PCI
1579	help
1580	  Enable AMD NUMA node topology detection.  You should say Y here if
1581	  you have a multi processor AMD system. This uses an old method to
1582	  read the NUMA configuration directly from the builtin Northbridge
1583	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1584	  which also takes priority if both are compiled in.
1585
1586config X86_64_ACPI_NUMA
1587	def_bool y
1588	prompt "ACPI NUMA detection"
1589	depends on X86_64 && NUMA && ACPI && PCI
1590	select ACPI_NUMA
1591	help
1592	  Enable ACPI SRAT based node topology detection.
1593
1594config NUMA_EMU
1595	bool "NUMA emulation"
1596	depends on NUMA
1597	help
1598	  Enable NUMA emulation. A flat machine will be split
1599	  into virtual nodes when booted with "numa=fake=N", where N is the
1600	  number of nodes. This is only useful for debugging.
1601
1602config NODES_SHIFT
1603	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1604	range 1 10
1605	default "10" if MAXSMP
1606	default "6" if X86_64
1607	default "3"
1608	depends on NUMA
1609	help
1610	  Specify the maximum number of NUMA Nodes available on the target
1611	  system.  Increases memory reserved to accommodate various tables.
1612
1613config ARCH_FLATMEM_ENABLE
1614	def_bool y
1615	depends on X86_32 && !NUMA
1616
1617config ARCH_SPARSEMEM_ENABLE
1618	def_bool y
1619	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1620	select SPARSEMEM_STATIC if X86_32
1621	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1622
1623config ARCH_SPARSEMEM_DEFAULT
1624	def_bool X86_64 || (NUMA && X86_32)
1625
1626config ARCH_SELECT_MEMORY_MODEL
1627	def_bool y
1628	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1629
1630config ARCH_MEMORY_PROBE
1631	bool "Enable sysfs memory/probe interface"
1632	depends on MEMORY_HOTPLUG
1633	help
1634	  This option enables a sysfs memory/probe interface for testing.
1635	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1636	  If you are unsure how to answer this question, answer N.
1637
1638config ARCH_PROC_KCORE_TEXT
1639	def_bool y
1640	depends on X86_64 && PROC_KCORE
1641
1642config ILLEGAL_POINTER_VALUE
1643	hex
1644	default 0 if X86_32
1645	default 0xdead000000000000 if X86_64
1646
1647config X86_PMEM_LEGACY_DEVICE
1648	bool
1649
1650config X86_PMEM_LEGACY
1651	tristate "Support non-standard NVDIMMs and ADR protected memory"
1652	depends on PHYS_ADDR_T_64BIT
1653	depends on BLK_DEV
1654	select X86_PMEM_LEGACY_DEVICE
1655	select NUMA_KEEP_MEMINFO if NUMA
1656	select LIBNVDIMM
1657	help
1658	  Treat memory marked using the non-standard e820 type of 12 as used
1659	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1660	  The kernel will offer these regions to the 'pmem' driver so
1661	  they can be used for persistent storage.
1662
1663	  Say Y if unsure.
1664
1665config HIGHPTE
1666	bool "Allocate 3rd-level pagetables from highmem"
1667	depends on HIGHMEM
1668	help
1669	  The VM uses one page table entry for each page of physical memory.
1670	  For systems with a lot of RAM, this can be wasteful of precious
1671	  low memory.  Setting this option will put user-space page table
1672	  entries in high memory.
1673
1674config X86_CHECK_BIOS_CORRUPTION
1675	bool "Check for low memory corruption"
1676	help
1677	  Periodically check for memory corruption in low memory, which
1678	  is suspected to be caused by BIOS.  Even when enabled in the
1679	  configuration, it is disabled at runtime.  Enable it by
1680	  setting "memory_corruption_check=1" on the kernel command
1681	  line.  By default it scans the low 64k of memory every 60
1682	  seconds; see the memory_corruption_check_size and
1683	  memory_corruption_check_period parameters in
1684	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1685
1686	  When enabled with the default parameters, this option has
1687	  almost no overhead, as it reserves a relatively small amount
1688	  of memory and scans it infrequently.  It both detects corruption
1689	  and prevents it from affecting the running system.
1690
1691	  It is, however, intended as a diagnostic tool; if repeatable
1692	  BIOS-originated corruption always affects the same memory,
1693	  you can use memmap= to prevent the kernel from using that
1694	  memory.
1695
1696config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1697	bool "Set the default setting of memory_corruption_check"
1698	depends on X86_CHECK_BIOS_CORRUPTION
1699	default y
1700	help
1701	  Set whether the default state of memory_corruption_check is
1702	  on or off.
1703
1704config MATH_EMULATION
1705	bool
1706	depends on MODIFY_LDT_SYSCALL
1707	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1708	help
1709	  Linux can emulate a math coprocessor (used for floating point
1710	  operations) if you don't have one. 486DX and Pentium processors have
1711	  a math coprocessor built in, 486SX and 386 do not, unless you added
1712	  a 487DX or 387, respectively. (The messages during boot time can
1713	  give you some hints here ["man dmesg"].) Everyone needs either a
1714	  coprocessor or this emulation.
1715
1716	  If you don't have a math coprocessor, you need to say Y here; if you
1717	  say Y here even though you have a coprocessor, the coprocessor will
1718	  be used nevertheless. (This behavior can be changed with the kernel
1719	  command line option "no387", which comes handy if your coprocessor
1720	  is broken. Try "man bootparam" or see the documentation of your boot
1721	  loader (lilo or loadlin) about how to pass options to the kernel at
1722	  boot time.) This means that it is a good idea to say Y here if you
1723	  intend to use this kernel on different machines.
1724
1725	  More information about the internals of the Linux math coprocessor
1726	  emulation can be found in <file:arch/x86/math-emu/README>.
1727
1728	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1729	  kernel, it won't hurt.
1730
1731config MTRR
1732	def_bool y
1733	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1734	help
1735	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1736	  the Memory Type Range Registers (MTRRs) may be used to control
1737	  processor access to memory ranges. This is most useful if you have
1738	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1739	  allows bus write transfers to be combined into a larger transfer
1740	  before bursting over the PCI/AGP bus. This can increase performance
1741	  of image write operations 2.5 times or more. Saying Y here creates a
1742	  /proc/mtrr file which may be used to manipulate your processor's
1743	  MTRRs. Typically the X server should use this.
1744
1745	  This code has a reasonably generic interface so that similar
1746	  control registers on other processors can be easily supported
1747	  as well:
1748
1749	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1750	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1751	  these, the ARRs are used to emulate the MTRRs.
1752	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1753	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1754	  write-combining. All of these processors are supported by this code
1755	  and it makes sense to say Y here if you have one of them.
1756
1757	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1758	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1759	  can lead to all sorts of problems, so it's good to say Y here.
1760
1761	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1762	  just add about 9 KB to your kernel.
1763
1764	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1765
1766config MTRR_SANITIZER
1767	def_bool y
1768	prompt "MTRR cleanup support"
1769	depends on MTRR
1770	help
1771	  Convert MTRR layout from continuous to discrete, so X drivers can
1772	  add writeback entries.
1773
1774	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1775	  The largest mtrr entry size for a continuous block can be set with
1776	  mtrr_chunk_size.
1777
1778	  If unsure, say Y.
1779
1780config MTRR_SANITIZER_ENABLE_DEFAULT
1781	int "MTRR cleanup enable value (0-1)"
1782	range 0 1
1783	default "0"
1784	depends on MTRR_SANITIZER
1785	help
1786	  Enable mtrr cleanup default value
1787
1788config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1789	int "MTRR cleanup spare reg num (0-7)"
1790	range 0 7
1791	default "1"
1792	depends on MTRR_SANITIZER
1793	help
1794	  mtrr cleanup spare entries default, it can be changed via
1795	  mtrr_spare_reg_nr=N on the kernel command line.
1796
1797config X86_PAT
1798	def_bool y
1799	prompt "x86 PAT support" if EXPERT
1800	depends on MTRR
1801	help
1802	  Use PAT attributes to setup page level cache control.
1803
1804	  PATs are the modern equivalents of MTRRs and are much more
1805	  flexible than MTRRs.
1806
1807	  Say N here if you see bootup problems (boot crash, boot hang,
1808	  spontaneous reboots) or a non-working video driver.
1809
1810	  If unsure, say Y.
1811
1812config ARCH_USES_PG_UNCACHED
1813	def_bool y
1814	depends on X86_PAT
1815
1816config X86_UMIP
1817	def_bool y
1818	prompt "User Mode Instruction Prevention" if EXPERT
1819	help
1820	  User Mode Instruction Prevention (UMIP) is a security feature in
1821	  some x86 processors. If enabled, a general protection fault is
1822	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1823	  executed in user mode. These instructions unnecessarily expose
1824	  information about the hardware state.
1825
1826	  The vast majority of applications do not use these instructions.
1827	  For the very few that do, software emulation is provided in
1828	  specific cases in protected and virtual-8086 modes. Emulated
1829	  results are dummy.
1830
1831config CC_HAS_IBT
1832	# GCC >= 9 and binutils >= 2.29
1833	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1834	# Clang/LLVM >= 14
1835	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1836	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1837	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1838		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1839		  $(as-instr,endbr64)
1840
1841config X86_CET
1842	def_bool n
1843	help
1844	  CET features configured (Shadow stack or IBT)
1845
1846config X86_KERNEL_IBT
1847	prompt "Indirect Branch Tracking"
1848	def_bool y
1849	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1850	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1851	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1852	select OBJTOOL
1853	select X86_CET
1854	help
1855	  Build the kernel with support for Indirect Branch Tracking, a
1856	  hardware support course-grain forward-edge Control Flow Integrity
1857	  protection. It enforces that all indirect calls must land on
1858	  an ENDBR instruction, as such, the compiler will instrument the
1859	  code with them to make this happen.
1860
1861	  In addition to building the kernel with IBT, seal all functions that
1862	  are not indirect call targets, avoiding them ever becoming one.
1863
1864	  This requires LTO like objtool runs and will slow down the build. It
1865	  does significantly reduce the number of ENDBR instructions in the
1866	  kernel image.
1867
1868config X86_INTEL_MEMORY_PROTECTION_KEYS
1869	prompt "Memory Protection Keys"
1870	def_bool y
1871	# Note: only available in 64-bit mode
1872	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1873	select ARCH_USES_HIGH_VMA_FLAGS
1874	select ARCH_HAS_PKEYS
1875	help
1876	  Memory Protection Keys provides a mechanism for enforcing
1877	  page-based protections, but without requiring modification of the
1878	  page tables when an application changes protection domains.
1879
1880	  For details, see Documentation/core-api/protection-keys.rst
1881
1882	  If unsure, say y.
1883
1884choice
1885	prompt "TSX enable mode"
1886	depends on CPU_SUP_INTEL
1887	default X86_INTEL_TSX_MODE_OFF
1888	help
1889	  Intel's TSX (Transactional Synchronization Extensions) feature
1890	  allows to optimize locking protocols through lock elision which
1891	  can lead to a noticeable performance boost.
1892
1893	  On the other hand it has been shown that TSX can be exploited
1894	  to form side channel attacks (e.g. TAA) and chances are there
1895	  will be more of those attacks discovered in the future.
1896
1897	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1898	  might override this decision by tsx=on the command line parameter.
1899	  Even with TSX enabled, the kernel will attempt to enable the best
1900	  possible TAA mitigation setting depending on the microcode available
1901	  for the particular machine.
1902
1903	  This option allows to set the default tsx mode between tsx=on, =off
1904	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1905	  details.
1906
1907	  Say off if not sure, auto if TSX is in use but it should be used on safe
1908	  platforms or on if TSX is in use and the security aspect of tsx is not
1909	  relevant.
1910
1911config X86_INTEL_TSX_MODE_OFF
1912	bool "off"
1913	help
1914	  TSX is disabled if possible - equals to tsx=off command line parameter.
1915
1916config X86_INTEL_TSX_MODE_ON
1917	bool "on"
1918	help
1919	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1920	  line parameter.
1921
1922config X86_INTEL_TSX_MODE_AUTO
1923	bool "auto"
1924	help
1925	  TSX is enabled on TSX capable HW that is believed to be safe against
1926	  side channel attacks- equals the tsx=auto command line parameter.
1927endchoice
1928
1929config X86_SGX
1930	bool "Software Guard eXtensions (SGX)"
1931	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1932	depends on CRYPTO=y
1933	depends on CRYPTO_SHA256=y
1934	select MMU_NOTIFIER
1935	select NUMA_KEEP_MEMINFO if NUMA
1936	select XARRAY_MULTI
1937	help
1938	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1939	  that can be used by applications to set aside private regions of code
1940	  and data, referred to as enclaves. An enclave's private memory can
1941	  only be accessed by code running within the enclave. Accesses from
1942	  outside the enclave, including other enclaves, are disallowed by
1943	  hardware.
1944
1945	  If unsure, say N.
1946
1947config X86_USER_SHADOW_STACK
1948	bool "X86 userspace shadow stack"
1949	depends on AS_WRUSS
1950	depends on X86_64
1951	select ARCH_USES_HIGH_VMA_FLAGS
1952	select X86_CET
1953	help
1954	  Shadow stack protection is a hardware feature that detects function
1955	  return address corruption.  This helps mitigate ROP attacks.
1956	  Applications must be enabled to use it, and old userspace does not
1957	  get protection "for free".
1958
1959	  CPUs supporting shadow stacks were first released in 2020.
1960
1961	  See Documentation/arch/x86/shstk.rst for more information.
1962
1963	  If unsure, say N.
1964
1965config INTEL_TDX_HOST
1966	bool "Intel Trust Domain Extensions (TDX) host support"
1967	depends on CPU_SUP_INTEL
1968	depends on X86_64
1969	depends on KVM_INTEL
1970	depends on X86_X2APIC
1971	select ARCH_KEEP_MEMBLOCK
1972	depends on CONTIG_ALLOC
1973	depends on !KEXEC_CORE
1974	depends on X86_MCE
1975	help
1976	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1977	  host and certain physical attacks.  This option enables necessary TDX
1978	  support in the host kernel to run confidential VMs.
1979
1980	  If unsure, say N.
1981
1982config EFI
1983	bool "EFI runtime service support"
1984	depends on ACPI
1985	select UCS2_STRING
1986	select EFI_RUNTIME_WRAPPERS
1987	select ARCH_USE_MEMREMAP_PROT
1988	select EFI_RUNTIME_MAP if KEXEC_CORE
1989	help
1990	  This enables the kernel to use EFI runtime services that are
1991	  available (such as the EFI variable services).
1992
1993	  This option is only useful on systems that have EFI firmware.
1994	  In addition, you should use the latest ELILO loader available
1995	  at <http://elilo.sourceforge.net> in order to take advantage
1996	  of EFI runtime services. However, even with this option, the
1997	  resultant kernel should continue to boot on existing non-EFI
1998	  platforms.
1999
2000config EFI_STUB
2001	bool "EFI stub support"
2002	depends on EFI
2003	select RELOCATABLE
2004	help
2005	  This kernel feature allows a bzImage to be loaded directly
2006	  by EFI firmware without the use of a bootloader.
2007
2008	  See Documentation/admin-guide/efi-stub.rst for more information.
2009
2010config EFI_HANDOVER_PROTOCOL
2011	bool "EFI handover protocol (DEPRECATED)"
2012	depends on EFI_STUB
2013	default y
2014	help
2015	  Select this in order to include support for the deprecated EFI
2016	  handover protocol, which defines alternative entry points into the
2017	  EFI stub.  This is a practice that has no basis in the UEFI
2018	  specification, and requires a priori knowledge on the part of the
2019	  bootloader about Linux/x86 specific ways of passing the command line
2020	  and initrd, and where in memory those assets may be loaded.
2021
2022	  If in doubt, say Y. Even though the corresponding support is not
2023	  present in upstream GRUB or other bootloaders, most distros build
2024	  GRUB with numerous downstream patches applied, and may rely on the
2025	  handover protocol as as result.
2026
2027config EFI_MIXED
2028	bool "EFI mixed-mode support"
2029	depends on EFI_STUB && X86_64
2030	help
2031	  Enabling this feature allows a 64-bit kernel to be booted
2032	  on a 32-bit firmware, provided that your CPU supports 64-bit
2033	  mode.
2034
2035	  Note that it is not possible to boot a mixed-mode enabled
2036	  kernel via the EFI boot stub - a bootloader that supports
2037	  the EFI handover protocol must be used.
2038
2039	  If unsure, say N.
2040
2041config EFI_FAKE_MEMMAP
2042	bool "Enable EFI fake memory map"
2043	depends on EFI
2044	help
2045	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2046	  this parameter, you can add arbitrary attribute to specific memory
2047	  range by updating original (firmware provided) EFI memmap.  This is
2048	  useful for debugging of EFI memmap related feature, e.g., Address
2049	  Range Mirroring feature.
2050
2051config EFI_MAX_FAKE_MEM
2052	int "maximum allowable number of ranges in efi_fake_mem boot option"
2053	depends on EFI_FAKE_MEMMAP
2054	range 1 128
2055	default 8
2056	help
2057	  Maximum allowable number of ranges in efi_fake_mem boot option.
2058	  Ranges can be set up to this value using comma-separated list.
2059	  The default value is 8.
2060
2061config EFI_RUNTIME_MAP
2062	bool "Export EFI runtime maps to sysfs" if EXPERT
2063	depends on EFI
2064	help
2065	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2066	  That memory map is required by the 2nd kernel to set up EFI virtual
2067	  mappings after kexec, but can also be used for debugging purposes.
2068
2069	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2070
2071source "kernel/Kconfig.hz"
2072
2073config ARCH_SUPPORTS_KEXEC
2074	def_bool y
2075
2076config ARCH_SUPPORTS_KEXEC_FILE
2077	def_bool X86_64
2078
2079config ARCH_SELECTS_KEXEC_FILE
2080	def_bool y
2081	depends on KEXEC_FILE
2082	select HAVE_IMA_KEXEC if IMA
2083
2084config ARCH_SUPPORTS_KEXEC_PURGATORY
2085	def_bool y
2086
2087config ARCH_SUPPORTS_KEXEC_SIG
2088	def_bool y
2089
2090config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2091	def_bool y
2092
2093config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2094	def_bool y
2095
2096config ARCH_SUPPORTS_KEXEC_JUMP
2097	def_bool y
2098
2099config ARCH_SUPPORTS_CRASH_DUMP
2100	def_bool X86_64 || (X86_32 && HIGHMEM)
2101
2102config ARCH_SUPPORTS_CRASH_HOTPLUG
2103	def_bool y
2104
2105config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2106	def_bool CRASH_RESERVE
2107
2108config PHYSICAL_START
2109	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2110	default "0x1000000"
2111	help
2112	  This gives the physical address where the kernel is loaded.
2113
2114	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
2115	  will decompress itself to above physical address and run from there.
2116	  Otherwise, bzImage will run from the address where it has been loaded
2117	  by the boot loader. The only exception is if it is loaded below the
2118	  above physical address, in which case it will relocate itself there.
2119
2120	  In normal kdump cases one does not have to set/change this option
2121	  as now bzImage can be compiled as a completely relocatable image
2122	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2123	  address. This option is mainly useful for the folks who don't want
2124	  to use a bzImage for capturing the crash dump and want to use a
2125	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2126	  to be specifically compiled to run from a specific memory area
2127	  (normally a reserved region) and this option comes handy.
2128
2129	  So if you are using bzImage for capturing the crash dump,
2130	  leave the value here unchanged to 0x1000000 and set
2131	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2132	  for capturing the crash dump change this value to start of
2133	  the reserved region.  In other words, it can be set based on
2134	  the "X" value as specified in the "crashkernel=YM@XM"
2135	  command line boot parameter passed to the panic-ed
2136	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2137	  for more details about crash dumps.
2138
2139	  Usage of bzImage for capturing the crash dump is recommended as
2140	  one does not have to build two kernels. Same kernel can be used
2141	  as production kernel and capture kernel. Above option should have
2142	  gone away after relocatable bzImage support is introduced. But it
2143	  is present because there are users out there who continue to use
2144	  vmlinux for dump capture. This option should go away down the
2145	  line.
2146
2147	  Don't change this unless you know what you are doing.
2148
2149config RELOCATABLE
2150	bool "Build a relocatable kernel"
2151	default y
2152	help
2153	  This builds a kernel image that retains relocation information
2154	  so it can be loaded someplace besides the default 1MB.
2155	  The relocations tend to make the kernel binary about 10% larger,
2156	  but are discarded at runtime.
2157
2158	  One use is for the kexec on panic case where the recovery kernel
2159	  must live at a different physical address than the primary
2160	  kernel.
2161
2162	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2163	  it has been loaded at and the compile time physical address
2164	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2165
2166config RANDOMIZE_BASE
2167	bool "Randomize the address of the kernel image (KASLR)"
2168	depends on RELOCATABLE
2169	default y
2170	help
2171	  In support of Kernel Address Space Layout Randomization (KASLR),
2172	  this randomizes the physical address at which the kernel image
2173	  is decompressed and the virtual address where the kernel
2174	  image is mapped, as a security feature that deters exploit
2175	  attempts relying on knowledge of the location of kernel
2176	  code internals.
2177
2178	  On 64-bit, the kernel physical and virtual addresses are
2179	  randomized separately. The physical address will be anywhere
2180	  between 16MB and the top of physical memory (up to 64TB). The
2181	  virtual address will be randomized from 16MB up to 1GB (9 bits
2182	  of entropy). Note that this also reduces the memory space
2183	  available to kernel modules from 1.5GB to 1GB.
2184
2185	  On 32-bit, the kernel physical and virtual addresses are
2186	  randomized together. They will be randomized from 16MB up to
2187	  512MB (8 bits of entropy).
2188
2189	  Entropy is generated using the RDRAND instruction if it is
2190	  supported. If RDTSC is supported, its value is mixed into
2191	  the entropy pool as well. If neither RDRAND nor RDTSC are
2192	  supported, then entropy is read from the i8254 timer. The
2193	  usable entropy is limited by the kernel being built using
2194	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2195	  minimum of 2MB. As a result, only 10 bits of entropy are
2196	  theoretically possible, but the implementations are further
2197	  limited due to memory layouts.
2198
2199	  If unsure, say Y.
2200
2201# Relocation on x86 needs some additional build support
2202config X86_NEED_RELOCS
2203	def_bool y
2204	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2205
2206config PHYSICAL_ALIGN
2207	hex "Alignment value to which kernel should be aligned"
2208	default "0x200000"
2209	range 0x2000 0x1000000 if X86_32
2210	range 0x200000 0x1000000 if X86_64
2211	help
2212	  This value puts the alignment restrictions on physical address
2213	  where kernel is loaded and run from. Kernel is compiled for an
2214	  address which meets above alignment restriction.
2215
2216	  If bootloader loads the kernel at a non-aligned address and
2217	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2218	  address aligned to above value and run from there.
2219
2220	  If bootloader loads the kernel at a non-aligned address and
2221	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2222	  load address and decompress itself to the address it has been
2223	  compiled for and run from there. The address for which kernel is
2224	  compiled already meets above alignment restrictions. Hence the
2225	  end result is that kernel runs from a physical address meeting
2226	  above alignment restrictions.
2227
2228	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2229	  this value must be a multiple of 0x200000.
2230
2231	  Don't change this unless you know what you are doing.
2232
2233config DYNAMIC_MEMORY_LAYOUT
2234	bool
2235	help
2236	  This option makes base addresses of vmalloc and vmemmap as well as
2237	  __PAGE_OFFSET movable during boot.
2238
2239config RANDOMIZE_MEMORY
2240	bool "Randomize the kernel memory sections"
2241	depends on X86_64
2242	depends on RANDOMIZE_BASE
2243	select DYNAMIC_MEMORY_LAYOUT
2244	default RANDOMIZE_BASE
2245	help
2246	  Randomizes the base virtual address of kernel memory sections
2247	  (physical memory mapping, vmalloc & vmemmap). This security feature
2248	  makes exploits relying on predictable memory locations less reliable.
2249
2250	  The order of allocations remains unchanged. Entropy is generated in
2251	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2252	  configuration have in average 30,000 different possible virtual
2253	  addresses for each memory section.
2254
2255	  If unsure, say Y.
2256
2257config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2258	hex "Physical memory mapping padding" if EXPERT
2259	depends on RANDOMIZE_MEMORY
2260	default "0xa" if MEMORY_HOTPLUG
2261	default "0x0"
2262	range 0x1 0x40 if MEMORY_HOTPLUG
2263	range 0x0 0x40
2264	help
2265	  Define the padding in terabytes added to the existing physical
2266	  memory size during kernel memory randomization. It is useful
2267	  for memory hotplug support but reduces the entropy available for
2268	  address randomization.
2269
2270	  If unsure, leave at the default value.
2271
2272config ADDRESS_MASKING
2273	bool "Linear Address Masking support"
2274	depends on X86_64
2275	help
2276	  Linear Address Masking (LAM) modifies the checking that is applied
2277	  to 64-bit linear addresses, allowing software to use of the
2278	  untranslated address bits for metadata.
2279
2280	  The capability can be used for efficient address sanitizers (ASAN)
2281	  implementation and for optimizations in JITs.
2282
2283config HOTPLUG_CPU
2284	def_bool y
2285	depends on SMP
2286
2287config COMPAT_VDSO
2288	def_bool n
2289	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2290	depends on COMPAT_32
2291	help
2292	  Certain buggy versions of glibc will crash if they are
2293	  presented with a 32-bit vDSO that is not mapped at the address
2294	  indicated in its segment table.
2295
2296	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2297	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2298	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2299	  the only released version with the bug, but OpenSUSE 9
2300	  contains a buggy "glibc 2.3.2".
2301
2302	  The symptom of the bug is that everything crashes on startup, saying:
2303	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2304
2305	  Saying Y here changes the default value of the vdso32 boot
2306	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2307	  This works around the glibc bug but hurts performance.
2308
2309	  If unsure, say N: if you are compiling your own kernel, you
2310	  are unlikely to be using a buggy version of glibc.
2311
2312choice
2313	prompt "vsyscall table for legacy applications"
2314	depends on X86_64
2315	default LEGACY_VSYSCALL_XONLY
2316	help
2317	  Legacy user code that does not know how to find the vDSO expects
2318	  to be able to issue three syscalls by calling fixed addresses in
2319	  kernel space. Since this location is not randomized with ASLR,
2320	  it can be used to assist security vulnerability exploitation.
2321
2322	  This setting can be changed at boot time via the kernel command
2323	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2324	  is deprecated and can only be enabled using the kernel command
2325	  line.
2326
2327	  On a system with recent enough glibc (2.14 or newer) and no
2328	  static binaries, you can say None without a performance penalty
2329	  to improve security.
2330
2331	  If unsure, select "Emulate execution only".
2332
2333	config LEGACY_VSYSCALL_XONLY
2334		bool "Emulate execution only"
2335		help
2336		  The kernel traps and emulates calls into the fixed vsyscall
2337		  address mapping and does not allow reads.  This
2338		  configuration is recommended when userspace might use the
2339		  legacy vsyscall area but support for legacy binary
2340		  instrumentation of legacy code is not needed.  It mitigates
2341		  certain uses of the vsyscall area as an ASLR-bypassing
2342		  buffer.
2343
2344	config LEGACY_VSYSCALL_NONE
2345		bool "None"
2346		help
2347		  There will be no vsyscall mapping at all. This will
2348		  eliminate any risk of ASLR bypass due to the vsyscall
2349		  fixed address mapping. Attempts to use the vsyscalls
2350		  will be reported to dmesg, so that either old or
2351		  malicious userspace programs can be identified.
2352
2353endchoice
2354
2355config CMDLINE_BOOL
2356	bool "Built-in kernel command line"
2357	help
2358	  Allow for specifying boot arguments to the kernel at
2359	  build time.  On some systems (e.g. embedded ones), it is
2360	  necessary or convenient to provide some or all of the
2361	  kernel boot arguments with the kernel itself (that is,
2362	  to not rely on the boot loader to provide them.)
2363
2364	  To compile command line arguments into the kernel,
2365	  set this option to 'Y', then fill in the
2366	  boot arguments in CONFIG_CMDLINE.
2367
2368	  Systems with fully functional boot loaders (i.e. non-embedded)
2369	  should leave this option set to 'N'.
2370
2371config CMDLINE
2372	string "Built-in kernel command string"
2373	depends on CMDLINE_BOOL
2374	default ""
2375	help
2376	  Enter arguments here that should be compiled into the kernel
2377	  image and used at boot time.  If the boot loader provides a
2378	  command line at boot time, it is appended to this string to
2379	  form the full kernel command line, when the system boots.
2380
2381	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2382	  change this behavior.
2383
2384	  In most cases, the command line (whether built-in or provided
2385	  by the boot loader) should specify the device for the root
2386	  file system.
2387
2388config CMDLINE_OVERRIDE
2389	bool "Built-in command line overrides boot loader arguments"
2390	depends on CMDLINE_BOOL && CMDLINE != ""
2391	help
2392	  Set this option to 'Y' to have the kernel ignore the boot loader
2393	  command line, and use ONLY the built-in command line.
2394
2395	  This is used to work around broken boot loaders.  This should
2396	  be set to 'N' under normal conditions.
2397
2398config MODIFY_LDT_SYSCALL
2399	bool "Enable the LDT (local descriptor table)" if EXPERT
2400	default y
2401	help
2402	  Linux can allow user programs to install a per-process x86
2403	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2404	  call.  This is required to run 16-bit or segmented code such as
2405	  DOSEMU or some Wine programs.  It is also used by some very old
2406	  threading libraries.
2407
2408	  Enabling this feature adds a small amount of overhead to
2409	  context switches and increases the low-level kernel attack
2410	  surface.  Disabling it removes the modify_ldt(2) system call.
2411
2412	  Saying 'N' here may make sense for embedded or server kernels.
2413
2414config STRICT_SIGALTSTACK_SIZE
2415	bool "Enforce strict size checking for sigaltstack"
2416	depends on DYNAMIC_SIGFRAME
2417	help
2418	  For historical reasons MINSIGSTKSZ is a constant which became
2419	  already too small with AVX512 support. Add a mechanism to
2420	  enforce strict checking of the sigaltstack size against the
2421	  real size of the FPU frame. This option enables the check
2422	  by default. It can also be controlled via the kernel command
2423	  line option 'strict_sas_size' independent of this config
2424	  switch. Enabling it might break existing applications which
2425	  allocate a too small sigaltstack but 'work' because they
2426	  never get a signal delivered.
2427
2428	  Say 'N' unless you want to really enforce this check.
2429
2430source "kernel/livepatch/Kconfig"
2431
2432endmenu
2433
2434config CC_HAS_NAMED_AS
2435	def_bool CC_IS_GCC && GCC_VERSION >= 90100
2436
2437config CC_HAS_NAMED_AS_FIXED_SANITIZERS
2438	def_bool CC_IS_GCC && GCC_VERSION >= 130300
2439
2440config USE_X86_SEG_SUPPORT
2441	def_bool y
2442	depends on CC_HAS_NAMED_AS
2443	#
2444	# -fsanitize=kernel-address (KASAN) and -fsanitize=thread
2445	# (KCSAN) are incompatible with named address spaces with
2446	# GCC < 13.3 - see GCC PR sanitizer/111736.
2447	#
2448	depends on !(KASAN || KCSAN) || CC_HAS_NAMED_AS_FIXED_SANITIZERS
2449
2450config CC_HAS_SLS
2451	def_bool $(cc-option,-mharden-sls=all)
2452
2453config CC_HAS_RETURN_THUNK
2454	def_bool $(cc-option,-mfunction-return=thunk-extern)
2455
2456config CC_HAS_ENTRY_PADDING
2457	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2458
2459config FUNCTION_PADDING_CFI
2460	int
2461	default 59 if FUNCTION_ALIGNMENT_64B
2462	default 27 if FUNCTION_ALIGNMENT_32B
2463	default 11 if FUNCTION_ALIGNMENT_16B
2464	default  3 if FUNCTION_ALIGNMENT_8B
2465	default  0
2466
2467# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2468# except Kconfig can't do arithmetic :/
2469config FUNCTION_PADDING_BYTES
2470	int
2471	default FUNCTION_PADDING_CFI if CFI_CLANG
2472	default FUNCTION_ALIGNMENT
2473
2474config CALL_PADDING
2475	def_bool n
2476	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2477	select FUNCTION_ALIGNMENT_16B
2478
2479config FINEIBT
2480	def_bool y
2481	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2482	select CALL_PADDING
2483
2484config HAVE_CALL_THUNKS
2485	def_bool y
2486	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
2487
2488config CALL_THUNKS
2489	def_bool n
2490	select CALL_PADDING
2491
2492config PREFIX_SYMBOLS
2493	def_bool y
2494	depends on CALL_PADDING && !CFI_CLANG
2495
2496menuconfig CPU_MITIGATIONS
2497	bool "Mitigations for CPU vulnerabilities"
2498	default y
2499	help
2500	  Say Y here to enable options which enable mitigations for hardware
2501	  vulnerabilities (usually related to speculative execution).
2502	  Mitigations can be disabled or restricted to SMT systems at runtime
2503	  via the "mitigations" kernel parameter.
2504
2505	  If you say N, all mitigations will be disabled.  This CANNOT be
2506	  overridden at runtime.
2507
2508	  Say 'Y', unless you really know what you are doing.
2509
2510if CPU_MITIGATIONS
2511
2512config MITIGATION_PAGE_TABLE_ISOLATION
2513	bool "Remove the kernel mapping in user mode"
2514	default y
2515	depends on (X86_64 || X86_PAE)
2516	help
2517	  This feature reduces the number of hardware side channels by
2518	  ensuring that the majority of kernel addresses are not mapped
2519	  into userspace.
2520
2521	  See Documentation/arch/x86/pti.rst for more details.
2522
2523config MITIGATION_RETPOLINE
2524	bool "Avoid speculative indirect branches in kernel"
2525	select OBJTOOL if HAVE_OBJTOOL
2526	default y
2527	help
2528	  Compile kernel with the retpoline compiler options to guard against
2529	  kernel-to-user data leaks by avoiding speculative indirect
2530	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2531	  support for full protection. The kernel may run slower.
2532
2533config MITIGATION_RETHUNK
2534	bool "Enable return-thunks"
2535	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2536	select OBJTOOL if HAVE_OBJTOOL
2537	default y if X86_64
2538	help
2539	  Compile the kernel with the return-thunks compiler option to guard
2540	  against kernel-to-user data leaks by avoiding return speculation.
2541	  Requires a compiler with -mfunction-return=thunk-extern
2542	  support for full protection. The kernel may run slower.
2543
2544config MITIGATION_UNRET_ENTRY
2545	bool "Enable UNRET on kernel entry"
2546	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2547	default y
2548	help
2549	  Compile the kernel with support for the retbleed=unret mitigation.
2550
2551config MITIGATION_CALL_DEPTH_TRACKING
2552	bool "Mitigate RSB underflow with call depth tracking"
2553	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2554	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2555	select CALL_THUNKS
2556	default y
2557	help
2558	  Compile the kernel with call depth tracking to mitigate the Intel
2559	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2560	  mitigation is off by default and needs to be enabled on the
2561	  kernel command line via the retbleed=stuff option. For
2562	  non-affected systems the overhead of this option is marginal as
2563	  the call depth tracking is using run-time generated call thunks
2564	  in a compiler generated padding area and call patching. This
2565	  increases text size by ~5%. For non affected systems this space
2566	  is unused. On affected SKL systems this results in a significant
2567	  performance gain over the IBRS mitigation.
2568
2569config CALL_THUNKS_DEBUG
2570	bool "Enable call thunks and call depth tracking debugging"
2571	depends on MITIGATION_CALL_DEPTH_TRACKING
2572	select FUNCTION_ALIGNMENT_32B
2573	default n
2574	help
2575	  Enable call/ret counters for imbalance detection and build in
2576	  a noisy dmesg about callthunks generation and call patching for
2577	  trouble shooting. The debug prints need to be enabled on the
2578	  kernel command line with 'debug-callthunks'.
2579	  Only enable this when you are debugging call thunks as this
2580	  creates a noticeable runtime overhead. If unsure say N.
2581
2582config MITIGATION_IBPB_ENTRY
2583	bool "Enable IBPB on kernel entry"
2584	depends on CPU_SUP_AMD && X86_64
2585	default y
2586	help
2587	  Compile the kernel with support for the retbleed=ibpb mitigation.
2588
2589config MITIGATION_IBRS_ENTRY
2590	bool "Enable IBRS on kernel entry"
2591	depends on CPU_SUP_INTEL && X86_64
2592	default y
2593	help
2594	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2595	  This mitigates both spectre_v2 and retbleed at great cost to
2596	  performance.
2597
2598config MITIGATION_SRSO
2599	bool "Mitigate speculative RAS overflow on AMD"
2600	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2601	default y
2602	help
2603	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2604
2605config MITIGATION_SLS
2606	bool "Mitigate Straight-Line-Speculation"
2607	depends on CC_HAS_SLS && X86_64
2608	select OBJTOOL if HAVE_OBJTOOL
2609	default n
2610	help
2611	  Compile the kernel with straight-line-speculation options to guard
2612	  against straight line speculation. The kernel image might be slightly
2613	  larger.
2614
2615config MITIGATION_GDS_FORCE
2616	bool "Force GDS Mitigation"
2617	depends on CPU_SUP_INTEL
2618	default n
2619	help
2620	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2621	  unprivileged speculative access to data which was previously stored in
2622	  vector registers.
2623
2624	  This option is equivalent to setting gather_data_sampling=force on the
2625	  command line. The microcode mitigation is used if present, otherwise
2626	  AVX is disabled as a mitigation. On affected systems that are missing
2627	  the microcode any userspace code that unconditionally uses AVX will
2628	  break with this option set.
2629
2630	  Setting this option on systems not vulnerable to GDS has no effect.
2631
2632	  If in doubt, say N.
2633
2634config MITIGATION_RFDS
2635	bool "RFDS Mitigation"
2636	depends on CPU_SUP_INTEL
2637	default y
2638	help
2639	  Enable mitigation for Register File Data Sampling (RFDS) by default.
2640	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
2641	  allows unprivileged speculative access to stale data previously
2642	  stored in floating point, vector and integer registers.
2643	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
2644
2645config MITIGATION_SPECTRE_BHI
2646	bool "Mitigate Spectre-BHB (Branch History Injection)"
2647	depends on CPU_SUP_INTEL
2648	default y
2649	help
2650	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2651	  where the branch history buffer is poisoned to speculatively steer
2652	  indirect branches.
2653	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2654
2655endif
2656
2657config ARCH_HAS_ADD_PAGES
2658	def_bool y
2659	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2660
2661menu "Power management and ACPI options"
2662
2663config ARCH_HIBERNATION_HEADER
2664	def_bool y
2665	depends on HIBERNATION
2666
2667source "kernel/power/Kconfig"
2668
2669source "drivers/acpi/Kconfig"
2670
2671config X86_APM_BOOT
2672	def_bool y
2673	depends on APM
2674
2675menuconfig APM
2676	tristate "APM (Advanced Power Management) BIOS support"
2677	depends on X86_32 && PM_SLEEP
2678	help
2679	  APM is a BIOS specification for saving power using several different
2680	  techniques. This is mostly useful for battery powered laptops with
2681	  APM compliant BIOSes. If you say Y here, the system time will be
2682	  reset after a RESUME operation, the /proc/apm device will provide
2683	  battery status information, and user-space programs will receive
2684	  notification of APM "events" (e.g. battery status change).
2685
2686	  If you select "Y" here, you can disable actual use of the APM
2687	  BIOS by passing the "apm=off" option to the kernel at boot time.
2688
2689	  Note that the APM support is almost completely disabled for
2690	  machines with more than one CPU.
2691
2692	  In order to use APM, you will need supporting software. For location
2693	  and more information, read <file:Documentation/power/apm-acpi.rst>
2694	  and the Battery Powered Linux mini-HOWTO, available from
2695	  <http://www.tldp.org/docs.html#howto>.
2696
2697	  This driver does not spin down disk drives (see the hdparm(8)
2698	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2699	  VESA-compliant "green" monitors.
2700
2701	  This driver does not support the TI 4000M TravelMate and the ACER
2702	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2703	  desktop machines also don't have compliant BIOSes, and this driver
2704	  may cause those machines to panic during the boot phase.
2705
2706	  Generally, if you don't have a battery in your machine, there isn't
2707	  much point in using this driver and you should say N. If you get
2708	  random kernel OOPSes or reboots that don't seem to be related to
2709	  anything, try disabling/enabling this option (or disabling/enabling
2710	  APM in your BIOS).
2711
2712	  Some other things you should try when experiencing seemingly random,
2713	  "weird" problems:
2714
2715	  1) make sure that you have enough swap space and that it is
2716	  enabled.
2717	  2) pass the "idle=poll" option to the kernel
2718	  3) switch on floating point emulation in the kernel and pass
2719	  the "no387" option to the kernel
2720	  4) pass the "floppy=nodma" option to the kernel
2721	  5) pass the "mem=4M" option to the kernel (thereby disabling
2722	  all but the first 4 MB of RAM)
2723	  6) make sure that the CPU is not over clocked.
2724	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2725	  8) disable the cache from your BIOS settings
2726	  9) install a fan for the video card or exchange video RAM
2727	  10) install a better fan for the CPU
2728	  11) exchange RAM chips
2729	  12) exchange the motherboard.
2730
2731	  To compile this driver as a module, choose M here: the
2732	  module will be called apm.
2733
2734if APM
2735
2736config APM_IGNORE_USER_SUSPEND
2737	bool "Ignore USER SUSPEND"
2738	help
2739	  This option will ignore USER SUSPEND requests. On machines with a
2740	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2741	  series notebooks, it is necessary to say Y because of a BIOS bug.
2742
2743config APM_DO_ENABLE
2744	bool "Enable PM at boot time"
2745	help
2746	  Enable APM features at boot time. From page 36 of the APM BIOS
2747	  specification: "When disabled, the APM BIOS does not automatically
2748	  power manage devices, enter the Standby State, enter the Suspend
2749	  State, or take power saving steps in response to CPU Idle calls."
2750	  This driver will make CPU Idle calls when Linux is idle (unless this
2751	  feature is turned off -- see "Do CPU IDLE calls", below). This
2752	  should always save battery power, but more complicated APM features
2753	  will be dependent on your BIOS implementation. You may need to turn
2754	  this option off if your computer hangs at boot time when using APM
2755	  support, or if it beeps continuously instead of suspending. Turn
2756	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2757	  T400CDT. This is off by default since most machines do fine without
2758	  this feature.
2759
2760config APM_CPU_IDLE
2761	depends on CPU_IDLE
2762	bool "Make CPU Idle calls when idle"
2763	help
2764	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2765	  On some machines, this can activate improved power savings, such as
2766	  a slowed CPU clock rate, when the machine is idle. These idle calls
2767	  are made after the idle loop has run for some length of time (e.g.,
2768	  333 mS). On some machines, this will cause a hang at boot time or
2769	  whenever the CPU becomes idle. (On machines with more than one CPU,
2770	  this option does nothing.)
2771
2772config APM_DISPLAY_BLANK
2773	bool "Enable console blanking using APM"
2774	help
2775	  Enable console blanking using the APM. Some laptops can use this to
2776	  turn off the LCD backlight when the screen blanker of the Linux
2777	  virtual console blanks the screen. Note that this is only used by
2778	  the virtual console screen blanker, and won't turn off the backlight
2779	  when using the X Window system. This also doesn't have anything to
2780	  do with your VESA-compliant power-saving monitor. Further, this
2781	  option doesn't work for all laptops -- it might not turn off your
2782	  backlight at all, or it might print a lot of errors to the console,
2783	  especially if you are using gpm.
2784
2785config APM_ALLOW_INTS
2786	bool "Allow interrupts during APM BIOS calls"
2787	help
2788	  Normally we disable external interrupts while we are making calls to
2789	  the APM BIOS as a measure to lessen the effects of a badly behaving
2790	  BIOS implementation.  The BIOS should reenable interrupts if it
2791	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2792	  many of the newer IBM Thinkpads.  If you experience hangs when you
2793	  suspend, try setting this to Y.  Otherwise, say N.
2794
2795endif # APM
2796
2797source "drivers/cpufreq/Kconfig"
2798
2799source "drivers/cpuidle/Kconfig"
2800
2801source "drivers/idle/Kconfig"
2802
2803endmenu
2804
2805menu "Bus options (PCI etc.)"
2806
2807choice
2808	prompt "PCI access mode"
2809	depends on X86_32 && PCI
2810	default PCI_GOANY
2811	help
2812	  On PCI systems, the BIOS can be used to detect the PCI devices and
2813	  determine their configuration. However, some old PCI motherboards
2814	  have BIOS bugs and may crash if this is done. Also, some embedded
2815	  PCI-based systems don't have any BIOS at all. Linux can also try to
2816	  detect the PCI hardware directly without using the BIOS.
2817
2818	  With this option, you can specify how Linux should detect the
2819	  PCI devices. If you choose "BIOS", the BIOS will be used,
2820	  if you choose "Direct", the BIOS won't be used, and if you
2821	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2822	  If you choose "Any", the kernel will try MMCONFIG, then the
2823	  direct access method and falls back to the BIOS if that doesn't
2824	  work. If unsure, go with the default, which is "Any".
2825
2826config PCI_GOBIOS
2827	bool "BIOS"
2828
2829config PCI_GOMMCONFIG
2830	bool "MMConfig"
2831
2832config PCI_GODIRECT
2833	bool "Direct"
2834
2835config PCI_GOOLPC
2836	bool "OLPC XO-1"
2837	depends on OLPC
2838
2839config PCI_GOANY
2840	bool "Any"
2841
2842endchoice
2843
2844config PCI_BIOS
2845	def_bool y
2846	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2847
2848# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2849config PCI_DIRECT
2850	def_bool y
2851	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2852
2853config PCI_MMCONFIG
2854	bool "Support mmconfig PCI config space access" if X86_64
2855	default y
2856	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2857	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2858
2859config PCI_OLPC
2860	def_bool y
2861	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2862
2863config PCI_XEN
2864	def_bool y
2865	depends on PCI && XEN
2866
2867config MMCONF_FAM10H
2868	def_bool y
2869	depends on X86_64 && PCI_MMCONFIG && ACPI
2870
2871config PCI_CNB20LE_QUIRK
2872	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2873	depends on PCI
2874	help
2875	  Read the PCI windows out of the CNB20LE host bridge. This allows
2876	  PCI hotplug to work on systems with the CNB20LE chipset which do
2877	  not have ACPI.
2878
2879	  There's no public spec for this chipset, and this functionality
2880	  is known to be incomplete.
2881
2882	  You should say N unless you know you need this.
2883
2884config ISA_BUS
2885	bool "ISA bus support on modern systems" if EXPERT
2886	help
2887	  Expose ISA bus device drivers and options available for selection and
2888	  configuration. Enable this option if your target machine has an ISA
2889	  bus. ISA is an older system, displaced by PCI and newer bus
2890	  architectures -- if your target machine is modern, it probably does
2891	  not have an ISA bus.
2892
2893	  If unsure, say N.
2894
2895# x86_64 have no ISA slots, but can have ISA-style DMA.
2896config ISA_DMA_API
2897	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2898	default y
2899	help
2900	  Enables ISA-style DMA support for devices requiring such controllers.
2901	  If unsure, say Y.
2902
2903if X86_32
2904
2905config ISA
2906	bool "ISA support"
2907	help
2908	  Find out whether you have ISA slots on your motherboard.  ISA is the
2909	  name of a bus system, i.e. the way the CPU talks to the other stuff
2910	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2911	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2912	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2913
2914config SCx200
2915	tristate "NatSemi SCx200 support"
2916	help
2917	  This provides basic support for National Semiconductor's
2918	  (now AMD's) Geode processors.  The driver probes for the
2919	  PCI-IDs of several on-chip devices, so its a good dependency
2920	  for other scx200_* drivers.
2921
2922	  If compiled as a module, the driver is named scx200.
2923
2924config SCx200HR_TIMER
2925	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2926	depends on SCx200
2927	default y
2928	help
2929	  This driver provides a clocksource built upon the on-chip
2930	  27MHz high-resolution timer.  Its also a workaround for
2931	  NSC Geode SC-1100's buggy TSC, which loses time when the
2932	  processor goes idle (as is done by the scheduler).  The
2933	  other workaround is idle=poll boot option.
2934
2935config OLPC
2936	bool "One Laptop Per Child support"
2937	depends on !X86_PAE
2938	select GPIOLIB
2939	select OF
2940	select OF_PROMTREE
2941	select IRQ_DOMAIN
2942	select OLPC_EC
2943	help
2944	  Add support for detecting the unique features of the OLPC
2945	  XO hardware.
2946
2947config OLPC_XO1_PM
2948	bool "OLPC XO-1 Power Management"
2949	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2950	help
2951	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2952
2953config OLPC_XO1_RTC
2954	bool "OLPC XO-1 Real Time Clock"
2955	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2956	help
2957	  Add support for the XO-1 real time clock, which can be used as a
2958	  programmable wakeup source.
2959
2960config OLPC_XO1_SCI
2961	bool "OLPC XO-1 SCI extras"
2962	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2963	depends on INPUT=y
2964	select POWER_SUPPLY
2965	help
2966	  Add support for SCI-based features of the OLPC XO-1 laptop:
2967	   - EC-driven system wakeups
2968	   - Power button
2969	   - Ebook switch
2970	   - Lid switch
2971	   - AC adapter status updates
2972	   - Battery status updates
2973
2974config OLPC_XO15_SCI
2975	bool "OLPC XO-1.5 SCI extras"
2976	depends on OLPC && ACPI
2977	select POWER_SUPPLY
2978	help
2979	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2980	   - EC-driven system wakeups
2981	   - AC adapter status updates
2982	   - Battery status updates
2983
2984config ALIX
2985	bool "PCEngines ALIX System Support (LED setup)"
2986	select GPIOLIB
2987	help
2988	  This option enables system support for the PCEngines ALIX.
2989	  At present this just sets up LEDs for GPIO control on
2990	  ALIX2/3/6 boards.  However, other system specific setup should
2991	  get added here.
2992
2993	  Note: You must still enable the drivers for GPIO and LED support
2994	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2995
2996	  Note: You have to set alix.force=1 for boards with Award BIOS.
2997
2998config NET5501
2999	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
3000	select GPIOLIB
3001	help
3002	  This option enables system support for the Soekris Engineering net5501.
3003
3004config GEOS
3005	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
3006	select GPIOLIB
3007	depends on DMI
3008	help
3009	  This option enables system support for the Traverse Technologies GEOS.
3010
3011config TS5500
3012	bool "Technologic Systems TS-5500 platform support"
3013	depends on MELAN
3014	select CHECK_SIGNATURE
3015	select NEW_LEDS
3016	select LEDS_CLASS
3017	help
3018	  This option enables system support for the Technologic Systems TS-5500.
3019
3020endif # X86_32
3021
3022config AMD_NB
3023	def_bool y
3024	depends on CPU_SUP_AMD && PCI
3025
3026endmenu
3027
3028menu "Binary Emulations"
3029
3030config IA32_EMULATION
3031	bool "IA32 Emulation"
3032	depends on X86_64
3033	select ARCH_WANT_OLD_COMPAT_IPC
3034	select BINFMT_ELF
3035	select COMPAT_OLD_SIGACTION
3036	help
3037	  Include code to run legacy 32-bit programs under a
3038	  64-bit kernel. You should likely turn this on, unless you're
3039	  100% sure that you don't have any 32-bit programs left.
3040
3041config IA32_EMULATION_DEFAULT_DISABLED
3042	bool "IA32 emulation disabled by default"
3043	default n
3044	depends on IA32_EMULATION
3045	help
3046	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3047	  processes and access to 32-bit syscalls. If unsure, leave it to its
3048	  default value.
3049
3050config X86_X32_ABI
3051	bool "x32 ABI for 64-bit mode"
3052	depends on X86_64
3053	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3054	# compressed debug sections to x86_x32 properly:
3055	# https://github.com/ClangBuiltLinux/linux/issues/514
3056	# https://github.com/ClangBuiltLinux/linux/issues/1141
3057	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3058	help
3059	  Include code to run binaries for the x32 native 32-bit ABI
3060	  for 64-bit processors.  An x32 process gets access to the
3061	  full 64-bit register file and wide data path while leaving
3062	  pointers at 32 bits for smaller memory footprint.
3063
3064config COMPAT_32
3065	def_bool y
3066	depends on IA32_EMULATION || X86_32
3067	select HAVE_UID16
3068	select OLD_SIGSUSPEND3
3069
3070config COMPAT
3071	def_bool y
3072	depends on IA32_EMULATION || X86_X32_ABI
3073
3074config COMPAT_FOR_U64_ALIGNMENT
3075	def_bool y
3076	depends on COMPAT
3077
3078endmenu
3079
3080config HAVE_ATOMIC_IOMAP
3081	def_bool y
3082	depends on X86_32
3083
3084source "arch/x86/kvm/Kconfig"
3085
3086source "arch/x86/Kconfig.assembler"
3087