xref: /openbmc/linux/arch/x86/Kconfig (revision 42c06a0e)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	help
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select GENERIC_VDSO_32
18	select HAVE_DEBUG_STACKOVERFLOW
19	select KMAP_LOCAL
20	select MODULES_USE_ELF_REL
21	select OLD_SIGACTION
22	select ARCH_SPLIT_ARG64
23
24config X86_64
25	def_bool y
26	depends on 64BIT
27	# Options that are inherently 64-bit kernel only:
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30	select ARCH_SUPPORTS_PER_VMA_LOCK
31	select ARCH_USE_CMPXCHG_LOCKREF
32	select HAVE_ARCH_SOFT_DIRTY
33	select MODULES_USE_ELF_RELA
34	select NEED_DMA_MAP_STATE
35	select SWIOTLB
36	select ARCH_HAS_ELFCORE_COMPAT
37	select ZONE_DMA32
38
39config FORCE_DYNAMIC_FTRACE
40	def_bool y
41	depends on X86_32
42	depends on FUNCTION_TRACER
43	select DYNAMIC_FTRACE
44	help
45	  We keep the static function tracing (!DYNAMIC_FTRACE) around
46	  in order to test the non static function tracing in the
47	  generic code, as other architectures still use it. But we
48	  only need to keep it around for x86_64. No need to keep it
49	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
50#
51# Arch settings
52#
53# ( Note that options that are marked 'if X86_64' could in principle be
54#   ported to 32-bit as well. )
55#
56config X86
57	def_bool y
58	#
59	# Note: keep this list sorted alphabetically
60	#
61	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
62	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
63	select ARCH_32BIT_OFF_T			if X86_32
64	select ARCH_CLOCKSOURCE_INIT
65	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
67	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
68	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
69	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
70	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
71	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
72	select ARCH_HAS_CACHE_LINE_SIZE
73	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
74	select ARCH_HAS_CPU_FINALIZE_INIT
75	select ARCH_HAS_CURRENT_STACK_POINTER
76	select ARCH_HAS_DEBUG_VIRTUAL
77	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
78	select ARCH_HAS_DEVMEM_IS_ALLOWED
79	select ARCH_HAS_EARLY_DEBUG		if KGDB
80	select ARCH_HAS_ELF_RANDOMIZE
81	select ARCH_HAS_FAST_MULTIPLIER
82	select ARCH_HAS_FORTIFY_SOURCE
83	select ARCH_HAS_GCOV_PROFILE_ALL
84	select ARCH_HAS_KCOV			if X86_64
85	select ARCH_HAS_MEM_ENCRYPT
86	select ARCH_HAS_MEMBARRIER_SYNC_CORE
87	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
88	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
89	select ARCH_HAS_PMEM_API		if X86_64
90	select ARCH_HAS_PTE_DEVMAP		if X86_64
91	select ARCH_HAS_PTE_SPECIAL
92	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
93	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
94	select ARCH_HAS_COPY_MC			if X86_64
95	select ARCH_HAS_SET_MEMORY
96	select ARCH_HAS_SET_DIRECT_MAP
97	select ARCH_HAS_STRICT_KERNEL_RWX
98	select ARCH_HAS_STRICT_MODULE_RWX
99	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
100	select ARCH_HAS_SYSCALL_WRAPPER
101	select ARCH_HAS_UBSAN_SANITIZE_ALL
102	select ARCH_HAS_DEBUG_WX
103	select ARCH_HAS_ZONE_DMA_SET if EXPERT
104	select ARCH_HAVE_NMI_SAFE_CMPXCHG
105	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
106	select ARCH_MIGHT_HAVE_PC_PARPORT
107	select ARCH_MIGHT_HAVE_PC_SERIO
108	select ARCH_STACKWALK
109	select ARCH_SUPPORTS_ACPI
110	select ARCH_SUPPORTS_ATOMIC_RMW
111	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
112	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
113	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
114	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
115	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
116	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
117	select ARCH_SUPPORTS_LTO_CLANG
118	select ARCH_SUPPORTS_LTO_CLANG_THIN
119	select ARCH_USE_BUILTIN_BSWAP
120	select ARCH_USE_MEMTEST
121	select ARCH_USE_QUEUED_RWLOCKS
122	select ARCH_USE_QUEUED_SPINLOCKS
123	select ARCH_USE_SYM_ANNOTATIONS
124	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
125	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
126	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
127	select ARCH_WANTS_NO_INSTR
128	select ARCH_WANT_GENERAL_HUGETLB
129	select ARCH_WANT_HUGE_PMD_SHARE
130	select ARCH_WANT_LD_ORPHAN_WARN
131	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
132	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
133	select ARCH_WANTS_THP_SWAP		if X86_64
134	select ARCH_HAS_PARANOID_L1D_FLUSH
135	select BUILDTIME_TABLE_SORT
136	select CLKEVT_I8253
137	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
138	select CLOCKSOURCE_WATCHDOG
139	# Word-size accesses may read uninitialized data past the trailing \0
140	# in strings and cause false KMSAN reports.
141	select DCACHE_WORD_ACCESS		if !KMSAN
142	select DYNAMIC_SIGFRAME
143	select EDAC_ATOMIC_SCRUB
144	select EDAC_SUPPORT
145	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
146	select GENERIC_CLOCKEVENTS_MIN_ADJUST
147	select GENERIC_CMOS_UPDATE
148	select GENERIC_CPU_AUTOPROBE
149	select GENERIC_CPU_VULNERABILITIES
150	select GENERIC_EARLY_IOREMAP
151	select GENERIC_ENTRY
152	select GENERIC_IOMAP
153	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
154	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
155	select GENERIC_IRQ_MIGRATION		if SMP
156	select GENERIC_IRQ_PROBE
157	select GENERIC_IRQ_RESERVATION_MODE
158	select GENERIC_IRQ_SHOW
159	select GENERIC_PENDING_IRQ		if SMP
160	select GENERIC_PTDUMP
161	select GENERIC_SMP_IDLE_THREAD
162	select GENERIC_TIME_VSYSCALL
163	select GENERIC_GETTIMEOFDAY
164	select GENERIC_VDSO_TIME_NS
165	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
166	select HARDIRQS_SW_RESEND
167	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
168	select HAS_IOPORT
169	select HAVE_ACPI_APEI			if ACPI
170	select HAVE_ACPI_APEI_NMI		if ACPI
171	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
172	select HAVE_ARCH_AUDITSYSCALL
173	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
174	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
175	select HAVE_ARCH_JUMP_LABEL
176	select HAVE_ARCH_JUMP_LABEL_RELATIVE
177	select HAVE_ARCH_KASAN			if X86_64
178	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
179	select HAVE_ARCH_KFENCE
180	select HAVE_ARCH_KMSAN			if X86_64
181	select HAVE_ARCH_KGDB
182	select HAVE_ARCH_MMAP_RND_BITS		if MMU
183	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
184	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
185	select HAVE_ARCH_PREL32_RELOCATIONS
186	select HAVE_ARCH_SECCOMP_FILTER
187	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
188	select HAVE_ARCH_STACKLEAK
189	select HAVE_ARCH_TRACEHOOK
190	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
191	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
192	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
193	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
194	select HAVE_ARCH_VMAP_STACK		if X86_64
195	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
196	select HAVE_ARCH_WITHIN_STACK_FRAMES
197	select HAVE_ASM_MODVERSIONS
198	select HAVE_CMPXCHG_DOUBLE
199	select HAVE_CMPXCHG_LOCAL
200	select HAVE_CONTEXT_TRACKING_USER		if X86_64
201	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
202	select HAVE_C_RECORDMCOUNT
203	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
204	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
205	select HAVE_BUILDTIME_MCOUNT_SORT
206	select HAVE_DEBUG_KMEMLEAK
207	select HAVE_DMA_CONTIGUOUS
208	select HAVE_DYNAMIC_FTRACE
209	select HAVE_DYNAMIC_FTRACE_WITH_REGS
210	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
211	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
212	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
213	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
214	select HAVE_EBPF_JIT
215	select HAVE_EFFICIENT_UNALIGNED_ACCESS
216	select HAVE_EISA
217	select HAVE_EXIT_THREAD
218	select HAVE_FAST_GUP
219	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
220	select HAVE_FTRACE_MCOUNT_RECORD
221	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
222	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
223	select HAVE_FUNCTION_TRACER
224	select HAVE_GCC_PLUGINS
225	select HAVE_HW_BREAKPOINT
226	select HAVE_IOREMAP_PROT
227	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
228	select HAVE_IRQ_TIME_ACCOUNTING
229	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
230	select HAVE_KERNEL_BZIP2
231	select HAVE_KERNEL_GZIP
232	select HAVE_KERNEL_LZ4
233	select HAVE_KERNEL_LZMA
234	select HAVE_KERNEL_LZO
235	select HAVE_KERNEL_XZ
236	select HAVE_KERNEL_ZSTD
237	select HAVE_KPROBES
238	select HAVE_KPROBES_ON_FTRACE
239	select HAVE_FUNCTION_ERROR_INJECTION
240	select HAVE_KRETPROBES
241	select HAVE_RETHOOK
242	select HAVE_KVM
243	select HAVE_LIVEPATCH			if X86_64
244	select HAVE_MIXED_BREAKPOINTS_REGS
245	select HAVE_MOD_ARCH_SPECIFIC
246	select HAVE_MOVE_PMD
247	select HAVE_MOVE_PUD
248	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
249	select HAVE_NMI
250	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
251	select HAVE_OBJTOOL			if X86_64
252	select HAVE_OPTPROBES
253	select HAVE_PCSPKR_PLATFORM
254	select HAVE_PERF_EVENTS
255	select HAVE_PERF_EVENTS_NMI
256	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
257	select HAVE_PCI
258	select HAVE_PERF_REGS
259	select HAVE_PERF_USER_STACK_DUMP
260	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
261	select MMU_GATHER_MERGE_VMAS
262	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
263	select HAVE_REGS_AND_STACK_ACCESS_API
264	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
265	select HAVE_FUNCTION_ARG_ACCESS_API
266	select HAVE_SETUP_PER_CPU_AREA
267	select HAVE_SOFTIRQ_ON_OWN_STACK
268	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
269	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
270	select HAVE_STATIC_CALL
271	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
272	select HAVE_PREEMPT_DYNAMIC_CALL
273	select HAVE_RSEQ
274	select HAVE_RUST			if X86_64
275	select HAVE_SYSCALL_TRACEPOINTS
276	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
277	select HAVE_UNSTABLE_SCHED_CLOCK
278	select HAVE_USER_RETURN_NOTIFIER
279	select HAVE_GENERIC_VDSO
280	select HOTPLUG_PARALLEL			if SMP && X86_64
281	select HOTPLUG_SMT			if SMP
282	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
283	select IRQ_FORCED_THREADING
284	select LOCK_MM_AND_FIND_VMA
285	select NEED_PER_CPU_EMBED_FIRST_CHUNK
286	select NEED_PER_CPU_PAGE_FIRST_CHUNK
287	select NEED_SG_DMA_LENGTH
288	select PCI_DOMAINS			if PCI
289	select PCI_LOCKLESS_CONFIG		if PCI
290	select PERF_EVENTS
291	select RTC_LIB
292	select RTC_MC146818_LIB
293	select SPARSE_IRQ
294	select SYSCTL_EXCEPTION_TRACE
295	select THREAD_INFO_IN_TASK
296	select TRACE_IRQFLAGS_SUPPORT
297	select TRACE_IRQFLAGS_NMI_SUPPORT
298	select USER_STACKTRACE_SUPPORT
299	select HAVE_ARCH_KCSAN			if X86_64
300	select PROC_PID_ARCH_STATUS		if PROC_FS
301	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
302	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
303	select FUNCTION_ALIGNMENT_4B
304	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
305	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
306
307config INSTRUCTION_DECODER
308	def_bool y
309	depends on KPROBES || PERF_EVENTS || UPROBES
310
311config OUTPUT_FORMAT
312	string
313	default "elf32-i386" if X86_32
314	default "elf64-x86-64" if X86_64
315
316config LOCKDEP_SUPPORT
317	def_bool y
318
319config STACKTRACE_SUPPORT
320	def_bool y
321
322config MMU
323	def_bool y
324
325config ARCH_MMAP_RND_BITS_MIN
326	default 28 if 64BIT
327	default 8
328
329config ARCH_MMAP_RND_BITS_MAX
330	default 32 if 64BIT
331	default 16
332
333config ARCH_MMAP_RND_COMPAT_BITS_MIN
334	default 8
335
336config ARCH_MMAP_RND_COMPAT_BITS_MAX
337	default 16
338
339config SBUS
340	bool
341
342config GENERIC_ISA_DMA
343	def_bool y
344	depends on ISA_DMA_API
345
346config GENERIC_CSUM
347	bool
348	default y if KMSAN || KASAN
349
350config GENERIC_BUG
351	def_bool y
352	depends on BUG
353	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
354
355config GENERIC_BUG_RELATIVE_POINTERS
356	bool
357
358config ARCH_MAY_HAVE_PC_FDC
359	def_bool y
360	depends on ISA_DMA_API
361
362config GENERIC_CALIBRATE_DELAY
363	def_bool y
364
365config ARCH_HAS_CPU_RELAX
366	def_bool y
367
368config ARCH_HIBERNATION_POSSIBLE
369	def_bool y
370
371config ARCH_SUSPEND_POSSIBLE
372	def_bool y
373
374config AUDIT_ARCH
375	def_bool y if X86_64
376
377config KASAN_SHADOW_OFFSET
378	hex
379	depends on KASAN
380	default 0xdffffc0000000000
381
382config HAVE_INTEL_TXT
383	def_bool y
384	depends on INTEL_IOMMU && ACPI
385
386config X86_32_SMP
387	def_bool y
388	depends on X86_32 && SMP
389
390config X86_64_SMP
391	def_bool y
392	depends on X86_64 && SMP
393
394config ARCH_SUPPORTS_UPROBES
395	def_bool y
396
397config FIX_EARLYCON_MEM
398	def_bool y
399
400config DYNAMIC_PHYSICAL_MASK
401	bool
402
403config PGTABLE_LEVELS
404	int
405	default 5 if X86_5LEVEL
406	default 4 if X86_64
407	default 3 if X86_PAE
408	default 2
409
410config CC_HAS_SANE_STACKPROTECTOR
411	bool
412	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
413	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
414	help
415	  We have to make sure stack protector is unconditionally disabled if
416	  the compiler produces broken code or if it does not let us control
417	  the segment on 32-bit kernels.
418
419menu "Processor type and features"
420
421config SMP
422	bool "Symmetric multi-processing support"
423	help
424	  This enables support for systems with more than one CPU. If you have
425	  a system with only one CPU, say N. If you have a system with more
426	  than one CPU, say Y.
427
428	  If you say N here, the kernel will run on uni- and multiprocessor
429	  machines, but will use only one CPU of a multiprocessor machine. If
430	  you say Y here, the kernel will run on many, but not all,
431	  uniprocessor machines. On a uniprocessor machine, the kernel
432	  will run faster if you say N here.
433
434	  Note that if you say Y here and choose architecture "586" or
435	  "Pentium" under "Processor family", the kernel will not work on 486
436	  architectures. Similarly, multiprocessor kernels for the "PPro"
437	  architecture may not work on all Pentium based boards.
438
439	  People using multiprocessor machines who say Y here should also say
440	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
441	  Management" code will be disabled if you say Y here.
442
443	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
444	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
445	  <http://www.tldp.org/docs.html#howto>.
446
447	  If you don't know what to do here, say N.
448
449config X86_X2APIC
450	bool "Support x2apic"
451	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
452	help
453	  This enables x2apic support on CPUs that have this feature.
454
455	  This allows 32-bit apic IDs (so it can support very large systems),
456	  and accesses the local apic via MSRs not via mmio.
457
458	  Some Intel systems circa 2022 and later are locked into x2APIC mode
459	  and can not fall back to the legacy APIC modes if SGX or TDX are
460	  enabled in the BIOS. They will boot with very reduced functionality
461	  without enabling this option.
462
463	  If you don't know what to do here, say N.
464
465config X86_MPPARSE
466	bool "Enable MPS table" if ACPI
467	default y
468	depends on X86_LOCAL_APIC
469	help
470	  For old smp systems that do not have proper acpi support. Newer systems
471	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
472
473config GOLDFISH
474	def_bool y
475	depends on X86_GOLDFISH
476
477config X86_CPU_RESCTRL
478	bool "x86 CPU resource control support"
479	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
480	select KERNFS
481	select PROC_CPU_RESCTRL		if PROC_FS
482	help
483	  Enable x86 CPU resource control support.
484
485	  Provide support for the allocation and monitoring of system resources
486	  usage by the CPU.
487
488	  Intel calls this Intel Resource Director Technology
489	  (Intel(R) RDT). More information about RDT can be found in the
490	  Intel x86 Architecture Software Developer Manual.
491
492	  AMD calls this AMD Platform Quality of Service (AMD QoS).
493	  More information about AMD QoS can be found in the AMD64 Technology
494	  Platform Quality of Service Extensions manual.
495
496	  Say N if unsure.
497
498if X86_32
499config X86_BIGSMP
500	bool "Support for big SMP systems with more than 8 CPUs"
501	depends on SMP
502	help
503	  This option is needed for the systems that have more than 8 CPUs.
504
505config X86_EXTENDED_PLATFORM
506	bool "Support for extended (non-PC) x86 platforms"
507	default y
508	help
509	  If you disable this option then the kernel will only support
510	  standard PC platforms. (which covers the vast majority of
511	  systems out there.)
512
513	  If you enable this option then you'll be able to select support
514	  for the following (non-PC) 32 bit x86 platforms:
515		Goldfish (Android emulator)
516		AMD Elan
517		RDC R-321x SoC
518		SGI 320/540 (Visual Workstation)
519		STA2X11-based (e.g. Northville)
520		Moorestown MID devices
521
522	  If you have one of these systems, or if you want to build a
523	  generic distribution kernel, say Y here - otherwise say N.
524endif # X86_32
525
526if X86_64
527config X86_EXTENDED_PLATFORM
528	bool "Support for extended (non-PC) x86 platforms"
529	default y
530	help
531	  If you disable this option then the kernel will only support
532	  standard PC platforms. (which covers the vast majority of
533	  systems out there.)
534
535	  If you enable this option then you'll be able to select support
536	  for the following (non-PC) 64 bit x86 platforms:
537		Numascale NumaChip
538		ScaleMP vSMP
539		SGI Ultraviolet
540
541	  If you have one of these systems, or if you want to build a
542	  generic distribution kernel, say Y here - otherwise say N.
543endif # X86_64
544# This is an alphabetically sorted list of 64 bit extended platforms
545# Please maintain the alphabetic order if and when there are additions
546config X86_NUMACHIP
547	bool "Numascale NumaChip"
548	depends on X86_64
549	depends on X86_EXTENDED_PLATFORM
550	depends on NUMA
551	depends on SMP
552	depends on X86_X2APIC
553	depends on PCI_MMCONFIG
554	help
555	  Adds support for Numascale NumaChip large-SMP systems. Needed to
556	  enable more than ~168 cores.
557	  If you don't have one of these, you should say N here.
558
559config X86_VSMP
560	bool "ScaleMP vSMP"
561	select HYPERVISOR_GUEST
562	select PARAVIRT
563	depends on X86_64 && PCI
564	depends on X86_EXTENDED_PLATFORM
565	depends on SMP
566	help
567	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
568	  supposed to run on these EM64T-based machines.  Only choose this option
569	  if you have one of these machines.
570
571config X86_UV
572	bool "SGI Ultraviolet"
573	depends on X86_64
574	depends on X86_EXTENDED_PLATFORM
575	depends on NUMA
576	depends on EFI
577	depends on KEXEC_CORE
578	depends on X86_X2APIC
579	depends on PCI
580	help
581	  This option is needed in order to support SGI Ultraviolet systems.
582	  If you don't have one of these, you should say N here.
583
584# Following is an alphabetically sorted list of 32 bit extended platforms
585# Please maintain the alphabetic order if and when there are additions
586
587config X86_GOLDFISH
588	bool "Goldfish (Virtual Platform)"
589	depends on X86_EXTENDED_PLATFORM
590	help
591	  Enable support for the Goldfish virtual platform used primarily
592	  for Android development. Unless you are building for the Android
593	  Goldfish emulator say N here.
594
595config X86_INTEL_CE
596	bool "CE4100 TV platform"
597	depends on PCI
598	depends on PCI_GODIRECT
599	depends on X86_IO_APIC
600	depends on X86_32
601	depends on X86_EXTENDED_PLATFORM
602	select X86_REBOOTFIXUPS
603	select OF
604	select OF_EARLY_FLATTREE
605	help
606	  Select for the Intel CE media processor (CE4100) SOC.
607	  This option compiles in support for the CE4100 SOC for settop
608	  boxes and media devices.
609
610config X86_INTEL_MID
611	bool "Intel MID platform support"
612	depends on X86_EXTENDED_PLATFORM
613	depends on X86_PLATFORM_DEVICES
614	depends on PCI
615	depends on X86_64 || (PCI_GOANY && X86_32)
616	depends on X86_IO_APIC
617	select I2C
618	select DW_APB_TIMER
619	select INTEL_SCU_PCI
620	help
621	  Select to build a kernel capable of supporting Intel MID (Mobile
622	  Internet Device) platform systems which do not have the PCI legacy
623	  interfaces. If you are building for a PC class system say N here.
624
625	  Intel MID platforms are based on an Intel processor and chipset which
626	  consume less power than most of the x86 derivatives.
627
628config X86_INTEL_QUARK
629	bool "Intel Quark platform support"
630	depends on X86_32
631	depends on X86_EXTENDED_PLATFORM
632	depends on X86_PLATFORM_DEVICES
633	depends on X86_TSC
634	depends on PCI
635	depends on PCI_GOANY
636	depends on X86_IO_APIC
637	select IOSF_MBI
638	select INTEL_IMR
639	select COMMON_CLK
640	help
641	  Select to include support for Quark X1000 SoC.
642	  Say Y here if you have a Quark based system such as the Arduino
643	  compatible Intel Galileo.
644
645config X86_INTEL_LPSS
646	bool "Intel Low Power Subsystem Support"
647	depends on X86 && ACPI && PCI
648	select COMMON_CLK
649	select PINCTRL
650	select IOSF_MBI
651	help
652	  Select to build support for Intel Low Power Subsystem such as
653	  found on Intel Lynxpoint PCH. Selecting this option enables
654	  things like clock tree (common clock framework) and pincontrol
655	  which are needed by the LPSS peripheral drivers.
656
657config X86_AMD_PLATFORM_DEVICE
658	bool "AMD ACPI2Platform devices support"
659	depends on ACPI
660	select COMMON_CLK
661	select PINCTRL
662	help
663	  Select to interpret AMD specific ACPI device to platform device
664	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
665	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
666	  implemented under PINCTRL subsystem.
667
668config IOSF_MBI
669	tristate "Intel SoC IOSF Sideband support for SoC platforms"
670	depends on PCI
671	help
672	  This option enables sideband register access support for Intel SoC
673	  platforms. On these platforms the IOSF sideband is used in lieu of
674	  MSR's for some register accesses, mostly but not limited to thermal
675	  and power. Drivers may query the availability of this device to
676	  determine if they need the sideband in order to work on these
677	  platforms. The sideband is available on the following SoC products.
678	  This list is not meant to be exclusive.
679	   - BayTrail
680	   - Braswell
681	   - Quark
682
683	  You should say Y if you are running a kernel on one of these SoC's.
684
685config IOSF_MBI_DEBUG
686	bool "Enable IOSF sideband access through debugfs"
687	depends on IOSF_MBI && DEBUG_FS
688	help
689	  Select this option to expose the IOSF sideband access registers (MCR,
690	  MDR, MCRX) through debugfs to write and read register information from
691	  different units on the SoC. This is most useful for obtaining device
692	  state information for debug and analysis. As this is a general access
693	  mechanism, users of this option would have specific knowledge of the
694	  device they want to access.
695
696	  If you don't require the option or are in doubt, say N.
697
698config X86_RDC321X
699	bool "RDC R-321x SoC"
700	depends on X86_32
701	depends on X86_EXTENDED_PLATFORM
702	select M486
703	select X86_REBOOTFIXUPS
704	help
705	  This option is needed for RDC R-321x system-on-chip, also known
706	  as R-8610-(G).
707	  If you don't have one of these chips, you should say N here.
708
709config X86_32_NON_STANDARD
710	bool "Support non-standard 32-bit SMP architectures"
711	depends on X86_32 && SMP
712	depends on X86_EXTENDED_PLATFORM
713	help
714	  This option compiles in the bigsmp and STA2X11 default
715	  subarchitectures.  It is intended for a generic binary
716	  kernel. If you select them all, kernel will probe it one by
717	  one and will fallback to default.
718
719# Alphabetically sorted list of Non standard 32 bit platforms
720
721config X86_SUPPORTS_MEMORY_FAILURE
722	def_bool y
723	# MCE code calls memory_failure():
724	depends on X86_MCE
725	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
726	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
727	depends on X86_64 || !SPARSEMEM
728	select ARCH_SUPPORTS_MEMORY_FAILURE
729
730config STA2X11
731	bool "STA2X11 Companion Chip Support"
732	depends on X86_32_NON_STANDARD && PCI
733	select SWIOTLB
734	select MFD_STA2X11
735	select GPIOLIB
736	help
737	  This adds support for boards based on the STA2X11 IO-Hub,
738	  a.k.a. "ConneXt". The chip is used in place of the standard
739	  PC chipset, so all "standard" peripherals are missing. If this
740	  option is selected the kernel will still be able to boot on
741	  standard PC machines.
742
743config X86_32_IRIS
744	tristate "Eurobraille/Iris poweroff module"
745	depends on X86_32
746	help
747	  The Iris machines from EuroBraille do not have APM or ACPI support
748	  to shut themselves down properly.  A special I/O sequence is
749	  needed to do so, which is what this module does at
750	  kernel shutdown.
751
752	  This is only for Iris machines from EuroBraille.
753
754	  If unused, say N.
755
756config SCHED_OMIT_FRAME_POINTER
757	def_bool y
758	prompt "Single-depth WCHAN output"
759	depends on X86
760	help
761	  Calculate simpler /proc/<PID>/wchan values. If this option
762	  is disabled then wchan values will recurse back to the
763	  caller function. This provides more accurate wchan values,
764	  at the expense of slightly more scheduling overhead.
765
766	  If in doubt, say "Y".
767
768menuconfig HYPERVISOR_GUEST
769	bool "Linux guest support"
770	help
771	  Say Y here to enable options for running Linux under various hyper-
772	  visors. This option enables basic hypervisor detection and platform
773	  setup.
774
775	  If you say N, all options in this submenu will be skipped and
776	  disabled, and Linux guest support won't be built in.
777
778if HYPERVISOR_GUEST
779
780config PARAVIRT
781	bool "Enable paravirtualization code"
782	depends on HAVE_STATIC_CALL
783	help
784	  This changes the kernel so it can modify itself when it is run
785	  under a hypervisor, potentially improving performance significantly
786	  over full virtualization.  However, when run without a hypervisor
787	  the kernel is theoretically slower and slightly larger.
788
789config PARAVIRT_XXL
790	bool
791
792config PARAVIRT_DEBUG
793	bool "paravirt-ops debugging"
794	depends on PARAVIRT && DEBUG_KERNEL
795	help
796	  Enable to debug paravirt_ops internals.  Specifically, BUG if
797	  a paravirt_op is missing when it is called.
798
799config PARAVIRT_SPINLOCKS
800	bool "Paravirtualization layer for spinlocks"
801	depends on PARAVIRT && SMP
802	help
803	  Paravirtualized spinlocks allow a pvops backend to replace the
804	  spinlock implementation with something virtualization-friendly
805	  (for example, block the virtual CPU rather than spinning).
806
807	  It has a minimal impact on native kernels and gives a nice performance
808	  benefit on paravirtualized KVM / Xen kernels.
809
810	  If you are unsure how to answer this question, answer Y.
811
812config X86_HV_CALLBACK_VECTOR
813	def_bool n
814
815source "arch/x86/xen/Kconfig"
816
817config KVM_GUEST
818	bool "KVM Guest support (including kvmclock)"
819	depends on PARAVIRT
820	select PARAVIRT_CLOCK
821	select ARCH_CPUIDLE_HALTPOLL
822	select X86_HV_CALLBACK_VECTOR
823	default y
824	help
825	  This option enables various optimizations for running under the KVM
826	  hypervisor. It includes a paravirtualized clock, so that instead
827	  of relying on a PIT (or probably other) emulation by the
828	  underlying device model, the host provides the guest with
829	  timing infrastructure such as time of day, and system time
830
831config ARCH_CPUIDLE_HALTPOLL
832	def_bool n
833	prompt "Disable host haltpoll when loading haltpoll driver"
834	help
835	  If virtualized under KVM, disable host haltpoll.
836
837config PVH
838	bool "Support for running PVH guests"
839	help
840	  This option enables the PVH entry point for guest virtual machines
841	  as specified in the x86/HVM direct boot ABI.
842
843config PARAVIRT_TIME_ACCOUNTING
844	bool "Paravirtual steal time accounting"
845	depends on PARAVIRT
846	help
847	  Select this option to enable fine granularity task steal time
848	  accounting. Time spent executing other tasks in parallel with
849	  the current vCPU is discounted from the vCPU power. To account for
850	  that, there can be a small performance impact.
851
852	  If in doubt, say N here.
853
854config PARAVIRT_CLOCK
855	bool
856
857config JAILHOUSE_GUEST
858	bool "Jailhouse non-root cell support"
859	depends on X86_64 && PCI
860	select X86_PM_TIMER
861	help
862	  This option allows to run Linux as guest in a Jailhouse non-root
863	  cell. You can leave this option disabled if you only want to start
864	  Jailhouse and run Linux afterwards in the root cell.
865
866config ACRN_GUEST
867	bool "ACRN Guest support"
868	depends on X86_64
869	select X86_HV_CALLBACK_VECTOR
870	help
871	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
872	  a flexible, lightweight reference open-source hypervisor, built with
873	  real-time and safety-criticality in mind. It is built for embedded
874	  IOT with small footprint and real-time features. More details can be
875	  found in https://projectacrn.org/.
876
877config INTEL_TDX_GUEST
878	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
879	depends on X86_64 && CPU_SUP_INTEL
880	depends on X86_X2APIC
881	depends on EFI_STUB
882	select ARCH_HAS_CC_PLATFORM
883	select X86_MEM_ENCRYPT
884	select X86_MCE
885	select UNACCEPTED_MEMORY
886	help
887	  Support running as a guest under Intel TDX.  Without this support,
888	  the guest kernel can not boot or run under TDX.
889	  TDX includes memory encryption and integrity capabilities
890	  which protect the confidentiality and integrity of guest
891	  memory contents and CPU state. TDX guests are protected from
892	  some attacks from the VMM.
893
894endif # HYPERVISOR_GUEST
895
896source "arch/x86/Kconfig.cpu"
897
898config HPET_TIMER
899	def_bool X86_64
900	prompt "HPET Timer Support" if X86_32
901	help
902	  Use the IA-PC HPET (High Precision Event Timer) to manage
903	  time in preference to the PIT and RTC, if a HPET is
904	  present.
905	  HPET is the next generation timer replacing legacy 8254s.
906	  The HPET provides a stable time base on SMP
907	  systems, unlike the TSC, but it is more expensive to access,
908	  as it is off-chip.  The interface used is documented
909	  in the HPET spec, revision 1.
910
911	  You can safely choose Y here.  However, HPET will only be
912	  activated if the platform and the BIOS support this feature.
913	  Otherwise the 8254 will be used for timing services.
914
915	  Choose N to continue using the legacy 8254 timer.
916
917config HPET_EMULATE_RTC
918	def_bool y
919	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
920
921# Mark as expert because too many people got it wrong.
922# The code disables itself when not needed.
923config DMI
924	default y
925	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
926	bool "Enable DMI scanning" if EXPERT
927	help
928	  Enabled scanning of DMI to identify machine quirks. Say Y
929	  here unless you have verified that your setup is not
930	  affected by entries in the DMI blacklist. Required by PNP
931	  BIOS code.
932
933config GART_IOMMU
934	bool "Old AMD GART IOMMU support"
935	select DMA_OPS
936	select IOMMU_HELPER
937	select SWIOTLB
938	depends on X86_64 && PCI && AMD_NB
939	help
940	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
941	  GART based hardware IOMMUs.
942
943	  The GART supports full DMA access for devices with 32-bit access
944	  limitations, on systems with more than 3 GB. This is usually needed
945	  for USB, sound, many IDE/SATA chipsets and some other devices.
946
947	  Newer systems typically have a modern AMD IOMMU, supported via
948	  the CONFIG_AMD_IOMMU=y config option.
949
950	  In normal configurations this driver is only active when needed:
951	  there's more than 3 GB of memory and the system contains a
952	  32-bit limited device.
953
954	  If unsure, say Y.
955
956config BOOT_VESA_SUPPORT
957	bool
958	help
959	  If true, at least one selected framebuffer driver can take advantage
960	  of VESA video modes set at an early boot stage via the vga= parameter.
961
962config MAXSMP
963	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
964	depends on X86_64 && SMP && DEBUG_KERNEL
965	select CPUMASK_OFFSTACK
966	help
967	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
968	  If unsure, say N.
969
970#
971# The maximum number of CPUs supported:
972#
973# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
974# and which can be configured interactively in the
975# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
976#
977# The ranges are different on 32-bit and 64-bit kernels, depending on
978# hardware capabilities and scalability features of the kernel.
979#
980# ( If MAXSMP is enabled we just use the highest possible value and disable
981#   interactive configuration. )
982#
983
984config NR_CPUS_RANGE_BEGIN
985	int
986	default NR_CPUS_RANGE_END if MAXSMP
987	default    1 if !SMP
988	default    2
989
990config NR_CPUS_RANGE_END
991	int
992	depends on X86_32
993	default   64 if  SMP &&  X86_BIGSMP
994	default    8 if  SMP && !X86_BIGSMP
995	default    1 if !SMP
996
997config NR_CPUS_RANGE_END
998	int
999	depends on X86_64
1000	default 8192 if  SMP && CPUMASK_OFFSTACK
1001	default  512 if  SMP && !CPUMASK_OFFSTACK
1002	default    1 if !SMP
1003
1004config NR_CPUS_DEFAULT
1005	int
1006	depends on X86_32
1007	default   32 if  X86_BIGSMP
1008	default    8 if  SMP
1009	default    1 if !SMP
1010
1011config NR_CPUS_DEFAULT
1012	int
1013	depends on X86_64
1014	default 8192 if  MAXSMP
1015	default   64 if  SMP
1016	default    1 if !SMP
1017
1018config NR_CPUS
1019	int "Maximum number of CPUs" if SMP && !MAXSMP
1020	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1021	default NR_CPUS_DEFAULT
1022	help
1023	  This allows you to specify the maximum number of CPUs which this
1024	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1025	  supported value is 8192, otherwise the maximum value is 512.  The
1026	  minimum value which makes sense is 2.
1027
1028	  This is purely to save memory: each supported CPU adds about 8KB
1029	  to the kernel image.
1030
1031config SCHED_CLUSTER
1032	bool "Cluster scheduler support"
1033	depends on SMP
1034	default y
1035	help
1036	  Cluster scheduler support improves the CPU scheduler's decision
1037	  making when dealing with machines that have clusters of CPUs.
1038	  Cluster usually means a couple of CPUs which are placed closely
1039	  by sharing mid-level caches, last-level cache tags or internal
1040	  busses.
1041
1042config SCHED_SMT
1043	def_bool y if SMP
1044
1045config SCHED_MC
1046	def_bool y
1047	prompt "Multi-core scheduler support"
1048	depends on SMP
1049	help
1050	  Multi-core scheduler support improves the CPU scheduler's decision
1051	  making when dealing with multi-core CPU chips at a cost of slightly
1052	  increased overhead in some places. If unsure say N here.
1053
1054config SCHED_MC_PRIO
1055	bool "CPU core priorities scheduler support"
1056	depends on SCHED_MC && CPU_SUP_INTEL
1057	select X86_INTEL_PSTATE
1058	select CPU_FREQ
1059	default y
1060	help
1061	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1062	  core ordering determined at manufacturing time, which allows
1063	  certain cores to reach higher turbo frequencies (when running
1064	  single threaded workloads) than others.
1065
1066	  Enabling this kernel feature teaches the scheduler about
1067	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1068	  scheduler's CPU selection logic accordingly, so that higher
1069	  overall system performance can be achieved.
1070
1071	  This feature will have no effect on CPUs without this feature.
1072
1073	  If unsure say Y here.
1074
1075config UP_LATE_INIT
1076	def_bool y
1077	depends on !SMP && X86_LOCAL_APIC
1078
1079config X86_UP_APIC
1080	bool "Local APIC support on uniprocessors" if !PCI_MSI
1081	default PCI_MSI
1082	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1083	help
1084	  A local APIC (Advanced Programmable Interrupt Controller) is an
1085	  integrated interrupt controller in the CPU. If you have a single-CPU
1086	  system which has a processor with a local APIC, you can say Y here to
1087	  enable and use it. If you say Y here even though your machine doesn't
1088	  have a local APIC, then the kernel will still run with no slowdown at
1089	  all. The local APIC supports CPU-generated self-interrupts (timer,
1090	  performance counters), and the NMI watchdog which detects hard
1091	  lockups.
1092
1093config X86_UP_IOAPIC
1094	bool "IO-APIC support on uniprocessors"
1095	depends on X86_UP_APIC
1096	help
1097	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1098	  SMP-capable replacement for PC-style interrupt controllers. Most
1099	  SMP systems and many recent uniprocessor systems have one.
1100
1101	  If you have a single-CPU system with an IO-APIC, you can say Y here
1102	  to use it. If you say Y here even though your machine doesn't have
1103	  an IO-APIC, then the kernel will still run with no slowdown at all.
1104
1105config X86_LOCAL_APIC
1106	def_bool y
1107	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1108	select IRQ_DOMAIN_HIERARCHY
1109
1110config X86_IO_APIC
1111	def_bool y
1112	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1113
1114config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1115	bool "Reroute for broken boot IRQs"
1116	depends on X86_IO_APIC
1117	help
1118	  This option enables a workaround that fixes a source of
1119	  spurious interrupts. This is recommended when threaded
1120	  interrupt handling is used on systems where the generation of
1121	  superfluous "boot interrupts" cannot be disabled.
1122
1123	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1124	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1125	  kernel does during interrupt handling). On chipsets where this
1126	  boot IRQ generation cannot be disabled, this workaround keeps
1127	  the original IRQ line masked so that only the equivalent "boot
1128	  IRQ" is delivered to the CPUs. The workaround also tells the
1129	  kernel to set up the IRQ handler on the boot IRQ line. In this
1130	  way only one interrupt is delivered to the kernel. Otherwise
1131	  the spurious second interrupt may cause the kernel to bring
1132	  down (vital) interrupt lines.
1133
1134	  Only affects "broken" chipsets. Interrupt sharing may be
1135	  increased on these systems.
1136
1137config X86_MCE
1138	bool "Machine Check / overheating reporting"
1139	select GENERIC_ALLOCATOR
1140	default y
1141	help
1142	  Machine Check support allows the processor to notify the
1143	  kernel if it detects a problem (e.g. overheating, data corruption).
1144	  The action the kernel takes depends on the severity of the problem,
1145	  ranging from warning messages to halting the machine.
1146
1147config X86_MCELOG_LEGACY
1148	bool "Support for deprecated /dev/mcelog character device"
1149	depends on X86_MCE
1150	help
1151	  Enable support for /dev/mcelog which is needed by the old mcelog
1152	  userspace logging daemon. Consider switching to the new generation
1153	  rasdaemon solution.
1154
1155config X86_MCE_INTEL
1156	def_bool y
1157	prompt "Intel MCE features"
1158	depends on X86_MCE && X86_LOCAL_APIC
1159	help
1160	  Additional support for intel specific MCE features such as
1161	  the thermal monitor.
1162
1163config X86_MCE_AMD
1164	def_bool y
1165	prompt "AMD MCE features"
1166	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1167	help
1168	  Additional support for AMD specific MCE features such as
1169	  the DRAM Error Threshold.
1170
1171config X86_ANCIENT_MCE
1172	bool "Support for old Pentium 5 / WinChip machine checks"
1173	depends on X86_32 && X86_MCE
1174	help
1175	  Include support for machine check handling on old Pentium 5 or WinChip
1176	  systems. These typically need to be enabled explicitly on the command
1177	  line.
1178
1179config X86_MCE_THRESHOLD
1180	depends on X86_MCE_AMD || X86_MCE_INTEL
1181	def_bool y
1182
1183config X86_MCE_INJECT
1184	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1185	tristate "Machine check injector support"
1186	help
1187	  Provide support for injecting machine checks for testing purposes.
1188	  If you don't know what a machine check is and you don't do kernel
1189	  QA it is safe to say n.
1190
1191source "arch/x86/events/Kconfig"
1192
1193config X86_LEGACY_VM86
1194	bool "Legacy VM86 support"
1195	depends on X86_32
1196	help
1197	  This option allows user programs to put the CPU into V8086
1198	  mode, which is an 80286-era approximation of 16-bit real mode.
1199
1200	  Some very old versions of X and/or vbetool require this option
1201	  for user mode setting.  Similarly, DOSEMU will use it if
1202	  available to accelerate real mode DOS programs.  However, any
1203	  recent version of DOSEMU, X, or vbetool should be fully
1204	  functional even without kernel VM86 support, as they will all
1205	  fall back to software emulation. Nevertheless, if you are using
1206	  a 16-bit DOS program where 16-bit performance matters, vm86
1207	  mode might be faster than emulation and you might want to
1208	  enable this option.
1209
1210	  Note that any app that works on a 64-bit kernel is unlikely to
1211	  need this option, as 64-bit kernels don't, and can't, support
1212	  V8086 mode. This option is also unrelated to 16-bit protected
1213	  mode and is not needed to run most 16-bit programs under Wine.
1214
1215	  Enabling this option increases the complexity of the kernel
1216	  and slows down exception handling a tiny bit.
1217
1218	  If unsure, say N here.
1219
1220config VM86
1221	bool
1222	default X86_LEGACY_VM86
1223
1224config X86_16BIT
1225	bool "Enable support for 16-bit segments" if EXPERT
1226	default y
1227	depends on MODIFY_LDT_SYSCALL
1228	help
1229	  This option is required by programs like Wine to run 16-bit
1230	  protected mode legacy code on x86 processors.  Disabling
1231	  this option saves about 300 bytes on i386, or around 6K text
1232	  plus 16K runtime memory on x86-64,
1233
1234config X86_ESPFIX32
1235	def_bool y
1236	depends on X86_16BIT && X86_32
1237
1238config X86_ESPFIX64
1239	def_bool y
1240	depends on X86_16BIT && X86_64
1241
1242config X86_VSYSCALL_EMULATION
1243	bool "Enable vsyscall emulation" if EXPERT
1244	default y
1245	depends on X86_64
1246	help
1247	  This enables emulation of the legacy vsyscall page.  Disabling
1248	  it is roughly equivalent to booting with vsyscall=none, except
1249	  that it will also disable the helpful warning if a program
1250	  tries to use a vsyscall.  With this option set to N, offending
1251	  programs will just segfault, citing addresses of the form
1252	  0xffffffffff600?00.
1253
1254	  This option is required by many programs built before 2013, and
1255	  care should be used even with newer programs if set to N.
1256
1257	  Disabling this option saves about 7K of kernel size and
1258	  possibly 4K of additional runtime pagetable memory.
1259
1260config X86_IOPL_IOPERM
1261	bool "IOPERM and IOPL Emulation"
1262	default y
1263	help
1264	  This enables the ioperm() and iopl() syscalls which are necessary
1265	  for legacy applications.
1266
1267	  Legacy IOPL support is an overbroad mechanism which allows user
1268	  space aside of accessing all 65536 I/O ports also to disable
1269	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1270	  capabilities and permission from potentially active security
1271	  modules.
1272
1273	  The emulation restricts the functionality of the syscall to
1274	  only allowing the full range I/O port access, but prevents the
1275	  ability to disable interrupts from user space which would be
1276	  granted if the hardware IOPL mechanism would be used.
1277
1278config TOSHIBA
1279	tristate "Toshiba Laptop support"
1280	depends on X86_32
1281	help
1282	  This adds a driver to safely access the System Management Mode of
1283	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1284	  not work on models with a Phoenix BIOS. The System Management Mode
1285	  is used to set the BIOS and power saving options on Toshiba portables.
1286
1287	  For information on utilities to make use of this driver see the
1288	  Toshiba Linux utilities web site at:
1289	  <http://www.buzzard.org.uk/toshiba/>.
1290
1291	  Say Y if you intend to run this kernel on a Toshiba portable.
1292	  Say N otherwise.
1293
1294config X86_REBOOTFIXUPS
1295	bool "Enable X86 board specific fixups for reboot"
1296	depends on X86_32
1297	help
1298	  This enables chipset and/or board specific fixups to be done
1299	  in order to get reboot to work correctly. This is only needed on
1300	  some combinations of hardware and BIOS. The symptom, for which
1301	  this config is intended, is when reboot ends with a stalled/hung
1302	  system.
1303
1304	  Currently, the only fixup is for the Geode machines using
1305	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1306
1307	  Say Y if you want to enable the fixup. Currently, it's safe to
1308	  enable this option even if you don't need it.
1309	  Say N otherwise.
1310
1311config MICROCODE
1312	bool "CPU microcode loading support"
1313	default y
1314	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1315	help
1316	  If you say Y here, you will be able to update the microcode on
1317	  Intel and AMD processors. The Intel support is for the IA32 family,
1318	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1319	  AMD support is for families 0x10 and later. You will obviously need
1320	  the actual microcode binary data itself which is not shipped with
1321	  the Linux kernel.
1322
1323	  The preferred method to load microcode from a detached initrd is described
1324	  in Documentation/arch/x86/microcode.rst. For that you need to enable
1325	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1326	  initrd for microcode blobs.
1327
1328	  In addition, you can build the microcode into the kernel. For that you
1329	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1330	  config option.
1331
1332config MICROCODE_INTEL
1333	bool "Intel microcode loading support"
1334	depends on CPU_SUP_INTEL && MICROCODE
1335	default MICROCODE
1336	help
1337	  This options enables microcode patch loading support for Intel
1338	  processors.
1339
1340	  For the current Intel microcode data package go to
1341	  <https://downloadcenter.intel.com> and search for
1342	  'Linux Processor Microcode Data File'.
1343
1344config MICROCODE_AMD
1345	bool "AMD microcode loading support"
1346	depends on CPU_SUP_AMD && MICROCODE
1347	help
1348	  If you select this option, microcode patch loading support for AMD
1349	  processors will be enabled.
1350
1351config MICROCODE_LATE_LOADING
1352	bool "Late microcode loading (DANGEROUS)"
1353	default n
1354	depends on MICROCODE
1355	help
1356	  Loading microcode late, when the system is up and executing instructions
1357	  is a tricky business and should be avoided if possible. Just the sequence
1358	  of synchronizing all cores and SMT threads is one fragile dance which does
1359	  not guarantee that cores might not softlock after the loading. Therefore,
1360	  use this at your own risk. Late loading taints the kernel too.
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 !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
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 && !HIGHMEM4G
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
1552config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1553	bool "Activate AMD Secure Memory Encryption (SME) by default"
1554	depends on AMD_MEM_ENCRYPT
1555	help
1556	  Say yes to have system memory encrypted by default if running on
1557	  an AMD processor that supports Secure Memory Encryption (SME).
1558
1559	  If set to Y, then the encryption of system memory can be
1560	  deactivated with the mem_encrypt=off command line option.
1561
1562	  If set to N, then the encryption of system memory can be
1563	  activated with the mem_encrypt=on command line option.
1564
1565# Common NUMA Features
1566config NUMA
1567	bool "NUMA Memory Allocation and Scheduler Support"
1568	depends on SMP
1569	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1570	default y if X86_BIGSMP
1571	select USE_PERCPU_NUMA_NODE_ID
1572	help
1573	  Enable NUMA (Non-Uniform Memory Access) support.
1574
1575	  The kernel will try to allocate memory used by a CPU on the
1576	  local memory controller of the CPU and add some more
1577	  NUMA awareness to the kernel.
1578
1579	  For 64-bit this is recommended if the system is Intel Core i7
1580	  (or later), AMD Opteron, or EM64T NUMA.
1581
1582	  For 32-bit this is only needed if you boot a 32-bit
1583	  kernel on a 64-bit NUMA platform.
1584
1585	  Otherwise, you should say N.
1586
1587config AMD_NUMA
1588	def_bool y
1589	prompt "Old style AMD Opteron NUMA detection"
1590	depends on X86_64 && NUMA && PCI
1591	help
1592	  Enable AMD NUMA node topology detection.  You should say Y here if
1593	  you have a multi processor AMD system. This uses an old method to
1594	  read the NUMA configuration directly from the builtin Northbridge
1595	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1596	  which also takes priority if both are compiled in.
1597
1598config X86_64_ACPI_NUMA
1599	def_bool y
1600	prompt "ACPI NUMA detection"
1601	depends on X86_64 && NUMA && ACPI && PCI
1602	select ACPI_NUMA
1603	help
1604	  Enable ACPI SRAT based node topology detection.
1605
1606config NUMA_EMU
1607	bool "NUMA emulation"
1608	depends on NUMA
1609	help
1610	  Enable NUMA emulation. A flat machine will be split
1611	  into virtual nodes when booted with "numa=fake=N", where N is the
1612	  number of nodes. This is only useful for debugging.
1613
1614config NODES_SHIFT
1615	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1616	range 1 10
1617	default "10" if MAXSMP
1618	default "6" if X86_64
1619	default "3"
1620	depends on NUMA
1621	help
1622	  Specify the maximum number of NUMA Nodes available on the target
1623	  system.  Increases memory reserved to accommodate various tables.
1624
1625config ARCH_FLATMEM_ENABLE
1626	def_bool y
1627	depends on X86_32 && !NUMA
1628
1629config ARCH_SPARSEMEM_ENABLE
1630	def_bool y
1631	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1632	select SPARSEMEM_STATIC if X86_32
1633	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1634
1635config ARCH_SPARSEMEM_DEFAULT
1636	def_bool X86_64 || (NUMA && X86_32)
1637
1638config ARCH_SELECT_MEMORY_MODEL
1639	def_bool y
1640	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1641
1642config ARCH_MEMORY_PROBE
1643	bool "Enable sysfs memory/probe interface"
1644	depends on MEMORY_HOTPLUG
1645	help
1646	  This option enables a sysfs memory/probe interface for testing.
1647	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1648	  If you are unsure how to answer this question, answer N.
1649
1650config ARCH_PROC_KCORE_TEXT
1651	def_bool y
1652	depends on X86_64 && PROC_KCORE
1653
1654config ILLEGAL_POINTER_VALUE
1655	hex
1656	default 0 if X86_32
1657	default 0xdead000000000000 if X86_64
1658
1659config X86_PMEM_LEGACY_DEVICE
1660	bool
1661
1662config X86_PMEM_LEGACY
1663	tristate "Support non-standard NVDIMMs and ADR protected memory"
1664	depends on PHYS_ADDR_T_64BIT
1665	depends on BLK_DEV
1666	select X86_PMEM_LEGACY_DEVICE
1667	select NUMA_KEEP_MEMINFO if NUMA
1668	select LIBNVDIMM
1669	help
1670	  Treat memory marked using the non-standard e820 type of 12 as used
1671	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1672	  The kernel will offer these regions to the 'pmem' driver so
1673	  they can be used for persistent storage.
1674
1675	  Say Y if unsure.
1676
1677config HIGHPTE
1678	bool "Allocate 3rd-level pagetables from highmem"
1679	depends on HIGHMEM
1680	help
1681	  The VM uses one page table entry for each page of physical memory.
1682	  For systems with a lot of RAM, this can be wasteful of precious
1683	  low memory.  Setting this option will put user-space page table
1684	  entries in high memory.
1685
1686config X86_CHECK_BIOS_CORRUPTION
1687	bool "Check for low memory corruption"
1688	help
1689	  Periodically check for memory corruption in low memory, which
1690	  is suspected to be caused by BIOS.  Even when enabled in the
1691	  configuration, it is disabled at runtime.  Enable it by
1692	  setting "memory_corruption_check=1" on the kernel command
1693	  line.  By default it scans the low 64k of memory every 60
1694	  seconds; see the memory_corruption_check_size and
1695	  memory_corruption_check_period parameters in
1696	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1697
1698	  When enabled with the default parameters, this option has
1699	  almost no overhead, as it reserves a relatively small amount
1700	  of memory and scans it infrequently.  It both detects corruption
1701	  and prevents it from affecting the running system.
1702
1703	  It is, however, intended as a diagnostic tool; if repeatable
1704	  BIOS-originated corruption always affects the same memory,
1705	  you can use memmap= to prevent the kernel from using that
1706	  memory.
1707
1708config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1709	bool "Set the default setting of memory_corruption_check"
1710	depends on X86_CHECK_BIOS_CORRUPTION
1711	default y
1712	help
1713	  Set whether the default state of memory_corruption_check is
1714	  on or off.
1715
1716config MATH_EMULATION
1717	bool
1718	depends on MODIFY_LDT_SYSCALL
1719	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1720	help
1721	  Linux can emulate a math coprocessor (used for floating point
1722	  operations) if you don't have one. 486DX and Pentium processors have
1723	  a math coprocessor built in, 486SX and 386 do not, unless you added
1724	  a 487DX or 387, respectively. (The messages during boot time can
1725	  give you some hints here ["man dmesg"].) Everyone needs either a
1726	  coprocessor or this emulation.
1727
1728	  If you don't have a math coprocessor, you need to say Y here; if you
1729	  say Y here even though you have a coprocessor, the coprocessor will
1730	  be used nevertheless. (This behavior can be changed with the kernel
1731	  command line option "no387", which comes handy if your coprocessor
1732	  is broken. Try "man bootparam" or see the documentation of your boot
1733	  loader (lilo or loadlin) about how to pass options to the kernel at
1734	  boot time.) This means that it is a good idea to say Y here if you
1735	  intend to use this kernel on different machines.
1736
1737	  More information about the internals of the Linux math coprocessor
1738	  emulation can be found in <file:arch/x86/math-emu/README>.
1739
1740	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1741	  kernel, it won't hurt.
1742
1743config MTRR
1744	def_bool y
1745	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1746	help
1747	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1748	  the Memory Type Range Registers (MTRRs) may be used to control
1749	  processor access to memory ranges. This is most useful if you have
1750	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1751	  allows bus write transfers to be combined into a larger transfer
1752	  before bursting over the PCI/AGP bus. This can increase performance
1753	  of image write operations 2.5 times or more. Saying Y here creates a
1754	  /proc/mtrr file which may be used to manipulate your processor's
1755	  MTRRs. Typically the X server should use this.
1756
1757	  This code has a reasonably generic interface so that similar
1758	  control registers on other processors can be easily supported
1759	  as well:
1760
1761	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1762	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1763	  these, the ARRs are used to emulate the MTRRs.
1764	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1765	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1766	  write-combining. All of these processors are supported by this code
1767	  and it makes sense to say Y here if you have one of them.
1768
1769	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1770	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1771	  can lead to all sorts of problems, so it's good to say Y here.
1772
1773	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1774	  just add about 9 KB to your kernel.
1775
1776	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1777
1778config MTRR_SANITIZER
1779	def_bool y
1780	prompt "MTRR cleanup support"
1781	depends on MTRR
1782	help
1783	  Convert MTRR layout from continuous to discrete, so X drivers can
1784	  add writeback entries.
1785
1786	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1787	  The largest mtrr entry size for a continuous block can be set with
1788	  mtrr_chunk_size.
1789
1790	  If unsure, say Y.
1791
1792config MTRR_SANITIZER_ENABLE_DEFAULT
1793	int "MTRR cleanup enable value (0-1)"
1794	range 0 1
1795	default "0"
1796	depends on MTRR_SANITIZER
1797	help
1798	  Enable mtrr cleanup default value
1799
1800config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1801	int "MTRR cleanup spare reg num (0-7)"
1802	range 0 7
1803	default "1"
1804	depends on MTRR_SANITIZER
1805	help
1806	  mtrr cleanup spare entries default, it can be changed via
1807	  mtrr_spare_reg_nr=N on the kernel command line.
1808
1809config X86_PAT
1810	def_bool y
1811	prompt "x86 PAT support" if EXPERT
1812	depends on MTRR
1813	help
1814	  Use PAT attributes to setup page level cache control.
1815
1816	  PATs are the modern equivalents of MTRRs and are much more
1817	  flexible than MTRRs.
1818
1819	  Say N here if you see bootup problems (boot crash, boot hang,
1820	  spontaneous reboots) or a non-working video driver.
1821
1822	  If unsure, say Y.
1823
1824config ARCH_USES_PG_UNCACHED
1825	def_bool y
1826	depends on X86_PAT
1827
1828config X86_UMIP
1829	def_bool y
1830	prompt "User Mode Instruction Prevention" if EXPERT
1831	help
1832	  User Mode Instruction Prevention (UMIP) is a security feature in
1833	  some x86 processors. If enabled, a general protection fault is
1834	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1835	  executed in user mode. These instructions unnecessarily expose
1836	  information about the hardware state.
1837
1838	  The vast majority of applications do not use these instructions.
1839	  For the very few that do, software emulation is provided in
1840	  specific cases in protected and virtual-8086 modes. Emulated
1841	  results are dummy.
1842
1843config CC_HAS_IBT
1844	# GCC >= 9 and binutils >= 2.29
1845	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1846	# Clang/LLVM >= 14
1847	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1848	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1849	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1850		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1851		  $(as-instr,endbr64)
1852
1853config X86_KERNEL_IBT
1854	prompt "Indirect Branch Tracking"
1855	def_bool y
1856	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1857	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1858	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1859	select OBJTOOL
1860	help
1861	  Build the kernel with support for Indirect Branch Tracking, a
1862	  hardware support course-grain forward-edge Control Flow Integrity
1863	  protection. It enforces that all indirect calls must land on
1864	  an ENDBR instruction, as such, the compiler will instrument the
1865	  code with them to make this happen.
1866
1867	  In addition to building the kernel with IBT, seal all functions that
1868	  are not indirect call targets, avoiding them ever becoming one.
1869
1870	  This requires LTO like objtool runs and will slow down the build. It
1871	  does significantly reduce the number of ENDBR instructions in the
1872	  kernel image.
1873
1874config X86_INTEL_MEMORY_PROTECTION_KEYS
1875	prompt "Memory Protection Keys"
1876	def_bool y
1877	# Note: only available in 64-bit mode
1878	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1879	select ARCH_USES_HIGH_VMA_FLAGS
1880	select ARCH_HAS_PKEYS
1881	help
1882	  Memory Protection Keys provides a mechanism for enforcing
1883	  page-based protections, but without requiring modification of the
1884	  page tables when an application changes protection domains.
1885
1886	  For details, see Documentation/core-api/protection-keys.rst
1887
1888	  If unsure, say y.
1889
1890choice
1891	prompt "TSX enable mode"
1892	depends on CPU_SUP_INTEL
1893	default X86_INTEL_TSX_MODE_OFF
1894	help
1895	  Intel's TSX (Transactional Synchronization Extensions) feature
1896	  allows to optimize locking protocols through lock elision which
1897	  can lead to a noticeable performance boost.
1898
1899	  On the other hand it has been shown that TSX can be exploited
1900	  to form side channel attacks (e.g. TAA) and chances are there
1901	  will be more of those attacks discovered in the future.
1902
1903	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1904	  might override this decision by tsx=on the command line parameter.
1905	  Even with TSX enabled, the kernel will attempt to enable the best
1906	  possible TAA mitigation setting depending on the microcode available
1907	  for the particular machine.
1908
1909	  This option allows to set the default tsx mode between tsx=on, =off
1910	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1911	  details.
1912
1913	  Say off if not sure, auto if TSX is in use but it should be used on safe
1914	  platforms or on if TSX is in use and the security aspect of tsx is not
1915	  relevant.
1916
1917config X86_INTEL_TSX_MODE_OFF
1918	bool "off"
1919	help
1920	  TSX is disabled if possible - equals to tsx=off command line parameter.
1921
1922config X86_INTEL_TSX_MODE_ON
1923	bool "on"
1924	help
1925	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1926	  line parameter.
1927
1928config X86_INTEL_TSX_MODE_AUTO
1929	bool "auto"
1930	help
1931	  TSX is enabled on TSX capable HW that is believed to be safe against
1932	  side channel attacks- equals the tsx=auto command line parameter.
1933endchoice
1934
1935config X86_SGX
1936	bool "Software Guard eXtensions (SGX)"
1937	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1938	depends on CRYPTO=y
1939	depends on CRYPTO_SHA256=y
1940	select MMU_NOTIFIER
1941	select NUMA_KEEP_MEMINFO if NUMA
1942	select XARRAY_MULTI
1943	help
1944	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1945	  that can be used by applications to set aside private regions of code
1946	  and data, referred to as enclaves. An enclave's private memory can
1947	  only be accessed by code running within the enclave. Accesses from
1948	  outside the enclave, including other enclaves, are disallowed by
1949	  hardware.
1950
1951	  If unsure, say N.
1952
1953config EFI
1954	bool "EFI runtime service support"
1955	depends on ACPI
1956	select UCS2_STRING
1957	select EFI_RUNTIME_WRAPPERS
1958	select ARCH_USE_MEMREMAP_PROT
1959	help
1960	  This enables the kernel to use EFI runtime services that are
1961	  available (such as the EFI variable services).
1962
1963	  This option is only useful on systems that have EFI firmware.
1964	  In addition, you should use the latest ELILO loader available
1965	  at <http://elilo.sourceforge.net> in order to take advantage
1966	  of EFI runtime services. However, even with this option, the
1967	  resultant kernel should continue to boot on existing non-EFI
1968	  platforms.
1969
1970config EFI_STUB
1971	bool "EFI stub support"
1972	depends on EFI
1973	select RELOCATABLE
1974	help
1975	  This kernel feature allows a bzImage to be loaded directly
1976	  by EFI firmware without the use of a bootloader.
1977
1978	  See Documentation/admin-guide/efi-stub.rst for more information.
1979
1980config EFI_HANDOVER_PROTOCOL
1981	bool "EFI handover protocol (DEPRECATED)"
1982	depends on EFI_STUB
1983	default y
1984	help
1985	  Select this in order to include support for the deprecated EFI
1986	  handover protocol, which defines alternative entry points into the
1987	  EFI stub.  This is a practice that has no basis in the UEFI
1988	  specification, and requires a priori knowledge on the part of the
1989	  bootloader about Linux/x86 specific ways of passing the command line
1990	  and initrd, and where in memory those assets may be loaded.
1991
1992	  If in doubt, say Y. Even though the corresponding support is not
1993	  present in upstream GRUB or other bootloaders, most distros build
1994	  GRUB with numerous downstream patches applied, and may rely on the
1995	  handover protocol as as result.
1996
1997config EFI_MIXED
1998	bool "EFI mixed-mode support"
1999	depends on EFI_STUB && X86_64
2000	help
2001	  Enabling this feature allows a 64-bit kernel to be booted
2002	  on a 32-bit firmware, provided that your CPU supports 64-bit
2003	  mode.
2004
2005	  Note that it is not possible to boot a mixed-mode enabled
2006	  kernel via the EFI boot stub - a bootloader that supports
2007	  the EFI handover protocol must be used.
2008
2009	  If unsure, say N.
2010
2011config EFI_FAKE_MEMMAP
2012	bool "Enable EFI fake memory map"
2013	depends on EFI
2014	help
2015	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2016	  this parameter, you can add arbitrary attribute to specific memory
2017	  range by updating original (firmware provided) EFI memmap.  This is
2018	  useful for debugging of EFI memmap related feature, e.g., Address
2019	  Range Mirroring feature.
2020
2021config EFI_MAX_FAKE_MEM
2022	int "maximum allowable number of ranges in efi_fake_mem boot option"
2023	depends on EFI_FAKE_MEMMAP
2024	range 1 128
2025	default 8
2026	help
2027	  Maximum allowable number of ranges in efi_fake_mem boot option.
2028	  Ranges can be set up to this value using comma-separated list.
2029	  The default value is 8.
2030
2031config EFI_RUNTIME_MAP
2032	bool "Export EFI runtime maps to sysfs" if EXPERT
2033	depends on EFI
2034	default KEXEC_CORE
2035	help
2036	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2037	  That memory map is required by the 2nd kernel to set up EFI virtual
2038	  mappings after kexec, but can also be used for debugging purposes.
2039
2040	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2041
2042source "kernel/Kconfig.hz"
2043
2044config KEXEC
2045	bool "kexec system call"
2046	select KEXEC_CORE
2047	help
2048	  kexec is a system call that implements the ability to shutdown your
2049	  current kernel, and to start another kernel.  It is like a reboot
2050	  but it is independent of the system firmware.   And like a reboot
2051	  you can start any kernel with it, not just Linux.
2052
2053	  The name comes from the similarity to the exec system call.
2054
2055	  It is an ongoing process to be certain the hardware in a machine
2056	  is properly shutdown, so do not be surprised if this code does not
2057	  initially work for you.  As of this writing the exact hardware
2058	  interface is strongly in flux, so no good recommendation can be
2059	  made.
2060
2061config KEXEC_FILE
2062	bool "kexec file based system call"
2063	select KEXEC_CORE
2064	select HAVE_IMA_KEXEC if IMA
2065	depends on X86_64
2066	depends on CRYPTO=y
2067	depends on CRYPTO_SHA256=y
2068	help
2069	  This is new version of kexec system call. This system call is
2070	  file based and takes file descriptors as system call argument
2071	  for kernel and initramfs as opposed to list of segments as
2072	  accepted by previous system call.
2073
2074config ARCH_HAS_KEXEC_PURGATORY
2075	def_bool KEXEC_FILE
2076
2077config KEXEC_SIG
2078	bool "Verify kernel signature during kexec_file_load() syscall"
2079	depends on KEXEC_FILE
2080	help
2081
2082	  This option makes the kexec_file_load() syscall check for a valid
2083	  signature of the kernel image.  The image can still be loaded without
2084	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2085	  there's a signature that we can check, then it must be valid.
2086
2087	  In addition to this option, you need to enable signature
2088	  verification for the corresponding kernel image type being
2089	  loaded in order for this to work.
2090
2091config KEXEC_SIG_FORCE
2092	bool "Require a valid signature in kexec_file_load() syscall"
2093	depends on KEXEC_SIG
2094	help
2095	  This option makes kernel signature verification mandatory for
2096	  the kexec_file_load() syscall.
2097
2098config KEXEC_BZIMAGE_VERIFY_SIG
2099	bool "Enable bzImage signature verification support"
2100	depends on KEXEC_SIG
2101	depends on SIGNED_PE_FILE_VERIFICATION
2102	select SYSTEM_TRUSTED_KEYRING
2103	help
2104	  Enable bzImage signature verification support.
2105
2106config CRASH_DUMP
2107	bool "kernel crash dumps"
2108	depends on X86_64 || (X86_32 && HIGHMEM)
2109	help
2110	  Generate crash dump after being started by kexec.
2111	  This should be normally only set in special crash dump kernels
2112	  which are loaded in the main kernel with kexec-tools into
2113	  a specially reserved region and then later executed after
2114	  a crash by kdump/kexec. The crash dump kernel must be compiled
2115	  to a memory address not used by the main kernel or BIOS using
2116	  PHYSICAL_START, or it must be built as a relocatable image
2117	  (CONFIG_RELOCATABLE=y).
2118	  For more details see Documentation/admin-guide/kdump/kdump.rst
2119
2120config KEXEC_JUMP
2121	bool "kexec jump"
2122	depends on KEXEC && HIBERNATION
2123	help
2124	  Jump between original kernel and kexeced kernel and invoke
2125	  code in physical address mode via KEXEC
2126
2127config PHYSICAL_START
2128	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2129	default "0x1000000"
2130	help
2131	  This gives the physical address where the kernel is loaded.
2132
2133	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2134	  bzImage will decompress itself to above physical address and
2135	  run from there. Otherwise, bzImage will run from the address where
2136	  it has been loaded by the boot loader and will ignore above physical
2137	  address.
2138
2139	  In normal kdump cases one does not have to set/change this option
2140	  as now bzImage can be compiled as a completely relocatable image
2141	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2142	  address. This option is mainly useful for the folks who don't want
2143	  to use a bzImage for capturing the crash dump and want to use a
2144	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2145	  to be specifically compiled to run from a specific memory area
2146	  (normally a reserved region) and this option comes handy.
2147
2148	  So if you are using bzImage for capturing the crash dump,
2149	  leave the value here unchanged to 0x1000000 and set
2150	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2151	  for capturing the crash dump change this value to start of
2152	  the reserved region.  In other words, it can be set based on
2153	  the "X" value as specified in the "crashkernel=YM@XM"
2154	  command line boot parameter passed to the panic-ed
2155	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2156	  for more details about crash dumps.
2157
2158	  Usage of bzImage for capturing the crash dump is recommended as
2159	  one does not have to build two kernels. Same kernel can be used
2160	  as production kernel and capture kernel. Above option should have
2161	  gone away after relocatable bzImage support is introduced. But it
2162	  is present because there are users out there who continue to use
2163	  vmlinux for dump capture. This option should go away down the
2164	  line.
2165
2166	  Don't change this unless you know what you are doing.
2167
2168config RELOCATABLE
2169	bool "Build a relocatable kernel"
2170	default y
2171	help
2172	  This builds a kernel image that retains relocation information
2173	  so it can be loaded someplace besides the default 1MB.
2174	  The relocations tend to make the kernel binary about 10% larger,
2175	  but are discarded at runtime.
2176
2177	  One use is for the kexec on panic case where the recovery kernel
2178	  must live at a different physical address than the primary
2179	  kernel.
2180
2181	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2182	  it has been loaded at and the compile time physical address
2183	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2184
2185config RANDOMIZE_BASE
2186	bool "Randomize the address of the kernel image (KASLR)"
2187	depends on RELOCATABLE
2188	default y
2189	help
2190	  In support of Kernel Address Space Layout Randomization (KASLR),
2191	  this randomizes the physical address at which the kernel image
2192	  is decompressed and the virtual address where the kernel
2193	  image is mapped, as a security feature that deters exploit
2194	  attempts relying on knowledge of the location of kernel
2195	  code internals.
2196
2197	  On 64-bit, the kernel physical and virtual addresses are
2198	  randomized separately. The physical address will be anywhere
2199	  between 16MB and the top of physical memory (up to 64TB). The
2200	  virtual address will be randomized from 16MB up to 1GB (9 bits
2201	  of entropy). Note that this also reduces the memory space
2202	  available to kernel modules from 1.5GB to 1GB.
2203
2204	  On 32-bit, the kernel physical and virtual addresses are
2205	  randomized together. They will be randomized from 16MB up to
2206	  512MB (8 bits of entropy).
2207
2208	  Entropy is generated using the RDRAND instruction if it is
2209	  supported. If RDTSC is supported, its value is mixed into
2210	  the entropy pool as well. If neither RDRAND nor RDTSC are
2211	  supported, then entropy is read from the i8254 timer. The
2212	  usable entropy is limited by the kernel being built using
2213	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2214	  minimum of 2MB. As a result, only 10 bits of entropy are
2215	  theoretically possible, but the implementations are further
2216	  limited due to memory layouts.
2217
2218	  If unsure, say Y.
2219
2220# Relocation on x86 needs some additional build support
2221config X86_NEED_RELOCS
2222	def_bool y
2223	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2224
2225config PHYSICAL_ALIGN
2226	hex "Alignment value to which kernel should be aligned"
2227	default "0x200000"
2228	range 0x2000 0x1000000 if X86_32
2229	range 0x200000 0x1000000 if X86_64
2230	help
2231	  This value puts the alignment restrictions on physical address
2232	  where kernel is loaded and run from. Kernel is compiled for an
2233	  address which meets above alignment restriction.
2234
2235	  If bootloader loads the kernel at a non-aligned address and
2236	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2237	  address aligned to above value and run from there.
2238
2239	  If bootloader loads the kernel at a non-aligned address and
2240	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2241	  load address and decompress itself to the address it has been
2242	  compiled for and run from there. The address for which kernel is
2243	  compiled already meets above alignment restrictions. Hence the
2244	  end result is that kernel runs from a physical address meeting
2245	  above alignment restrictions.
2246
2247	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2248	  this value must be a multiple of 0x200000.
2249
2250	  Don't change this unless you know what you are doing.
2251
2252config DYNAMIC_MEMORY_LAYOUT
2253	bool
2254	help
2255	  This option makes base addresses of vmalloc and vmemmap as well as
2256	  __PAGE_OFFSET movable during boot.
2257
2258config RANDOMIZE_MEMORY
2259	bool "Randomize the kernel memory sections"
2260	depends on X86_64
2261	depends on RANDOMIZE_BASE
2262	select DYNAMIC_MEMORY_LAYOUT
2263	default RANDOMIZE_BASE
2264	help
2265	  Randomizes the base virtual address of kernel memory sections
2266	  (physical memory mapping, vmalloc & vmemmap). This security feature
2267	  makes exploits relying on predictable memory locations less reliable.
2268
2269	  The order of allocations remains unchanged. Entropy is generated in
2270	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2271	  configuration have in average 30,000 different possible virtual
2272	  addresses for each memory section.
2273
2274	  If unsure, say Y.
2275
2276config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2277	hex "Physical memory mapping padding" if EXPERT
2278	depends on RANDOMIZE_MEMORY
2279	default "0xa" if MEMORY_HOTPLUG
2280	default "0x0"
2281	range 0x1 0x40 if MEMORY_HOTPLUG
2282	range 0x0 0x40
2283	help
2284	  Define the padding in terabytes added to the existing physical
2285	  memory size during kernel memory randomization. It is useful
2286	  for memory hotplug support but reduces the entropy available for
2287	  address randomization.
2288
2289	  If unsure, leave at the default value.
2290
2291config ADDRESS_MASKING
2292	bool "Linear Address Masking support"
2293	depends on X86_64
2294	help
2295	  Linear Address Masking (LAM) modifies the checking that is applied
2296	  to 64-bit linear addresses, allowing software to use of the
2297	  untranslated address bits for metadata.
2298
2299	  The capability can be used for efficient address sanitizers (ASAN)
2300	  implementation and for optimizations in JITs.
2301
2302config HOTPLUG_CPU
2303	def_bool y
2304	depends on SMP
2305
2306config COMPAT_VDSO
2307	def_bool n
2308	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2309	depends on COMPAT_32
2310	help
2311	  Certain buggy versions of glibc will crash if they are
2312	  presented with a 32-bit vDSO that is not mapped at the address
2313	  indicated in its segment table.
2314
2315	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2316	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2317	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2318	  the only released version with the bug, but OpenSUSE 9
2319	  contains a buggy "glibc 2.3.2".
2320
2321	  The symptom of the bug is that everything crashes on startup, saying:
2322	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2323
2324	  Saying Y here changes the default value of the vdso32 boot
2325	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2326	  This works around the glibc bug but hurts performance.
2327
2328	  If unsure, say N: if you are compiling your own kernel, you
2329	  are unlikely to be using a buggy version of glibc.
2330
2331choice
2332	prompt "vsyscall table for legacy applications"
2333	depends on X86_64
2334	default LEGACY_VSYSCALL_XONLY
2335	help
2336	  Legacy user code that does not know how to find the vDSO expects
2337	  to be able to issue three syscalls by calling fixed addresses in
2338	  kernel space. Since this location is not randomized with ASLR,
2339	  it can be used to assist security vulnerability exploitation.
2340
2341	  This setting can be changed at boot time via the kernel command
2342	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2343	  is deprecated and can only be enabled using the kernel command
2344	  line.
2345
2346	  On a system with recent enough glibc (2.14 or newer) and no
2347	  static binaries, you can say None without a performance penalty
2348	  to improve security.
2349
2350	  If unsure, select "Emulate execution only".
2351
2352	config LEGACY_VSYSCALL_XONLY
2353		bool "Emulate execution only"
2354		help
2355		  The kernel traps and emulates calls into the fixed vsyscall
2356		  address mapping and does not allow reads.  This
2357		  configuration is recommended when userspace might use the
2358		  legacy vsyscall area but support for legacy binary
2359		  instrumentation of legacy code is not needed.  It mitigates
2360		  certain uses of the vsyscall area as an ASLR-bypassing
2361		  buffer.
2362
2363	config LEGACY_VSYSCALL_NONE
2364		bool "None"
2365		help
2366		  There will be no vsyscall mapping at all. This will
2367		  eliminate any risk of ASLR bypass due to the vsyscall
2368		  fixed address mapping. Attempts to use the vsyscalls
2369		  will be reported to dmesg, so that either old or
2370		  malicious userspace programs can be identified.
2371
2372endchoice
2373
2374config CMDLINE_BOOL
2375	bool "Built-in kernel command line"
2376	help
2377	  Allow for specifying boot arguments to the kernel at
2378	  build time.  On some systems (e.g. embedded ones), it is
2379	  necessary or convenient to provide some or all of the
2380	  kernel boot arguments with the kernel itself (that is,
2381	  to not rely on the boot loader to provide them.)
2382
2383	  To compile command line arguments into the kernel,
2384	  set this option to 'Y', then fill in the
2385	  boot arguments in CONFIG_CMDLINE.
2386
2387	  Systems with fully functional boot loaders (i.e. non-embedded)
2388	  should leave this option set to 'N'.
2389
2390config CMDLINE
2391	string "Built-in kernel command string"
2392	depends on CMDLINE_BOOL
2393	default ""
2394	help
2395	  Enter arguments here that should be compiled into the kernel
2396	  image and used at boot time.  If the boot loader provides a
2397	  command line at boot time, it is appended to this string to
2398	  form the full kernel command line, when the system boots.
2399
2400	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2401	  change this behavior.
2402
2403	  In most cases, the command line (whether built-in or provided
2404	  by the boot loader) should specify the device for the root
2405	  file system.
2406
2407config CMDLINE_OVERRIDE
2408	bool "Built-in command line overrides boot loader arguments"
2409	depends on CMDLINE_BOOL && CMDLINE != ""
2410	help
2411	  Set this option to 'Y' to have the kernel ignore the boot loader
2412	  command line, and use ONLY the built-in command line.
2413
2414	  This is used to work around broken boot loaders.  This should
2415	  be set to 'N' under normal conditions.
2416
2417config MODIFY_LDT_SYSCALL
2418	bool "Enable the LDT (local descriptor table)" if EXPERT
2419	default y
2420	help
2421	  Linux can allow user programs to install a per-process x86
2422	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2423	  call.  This is required to run 16-bit or segmented code such as
2424	  DOSEMU or some Wine programs.  It is also used by some very old
2425	  threading libraries.
2426
2427	  Enabling this feature adds a small amount of overhead to
2428	  context switches and increases the low-level kernel attack
2429	  surface.  Disabling it removes the modify_ldt(2) system call.
2430
2431	  Saying 'N' here may make sense for embedded or server kernels.
2432
2433config STRICT_SIGALTSTACK_SIZE
2434	bool "Enforce strict size checking for sigaltstack"
2435	depends on DYNAMIC_SIGFRAME
2436	help
2437	  For historical reasons MINSIGSTKSZ is a constant which became
2438	  already too small with AVX512 support. Add a mechanism to
2439	  enforce strict checking of the sigaltstack size against the
2440	  real size of the FPU frame. This option enables the check
2441	  by default. It can also be controlled via the kernel command
2442	  line option 'strict_sas_size' independent of this config
2443	  switch. Enabling it might break existing applications which
2444	  allocate a too small sigaltstack but 'work' because they
2445	  never get a signal delivered.
2446
2447	  Say 'N' unless you want to really enforce this check.
2448
2449source "kernel/livepatch/Kconfig"
2450
2451endmenu
2452
2453config CC_HAS_SLS
2454	def_bool $(cc-option,-mharden-sls=all)
2455
2456config CC_HAS_RETURN_THUNK
2457	def_bool $(cc-option,-mfunction-return=thunk-extern)
2458
2459config CC_HAS_ENTRY_PADDING
2460	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2461
2462config FUNCTION_PADDING_CFI
2463	int
2464	default 59 if FUNCTION_ALIGNMENT_64B
2465	default 27 if FUNCTION_ALIGNMENT_32B
2466	default 11 if FUNCTION_ALIGNMENT_16B
2467	default  3 if FUNCTION_ALIGNMENT_8B
2468	default  0
2469
2470# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2471# except Kconfig can't do arithmetic :/
2472config FUNCTION_PADDING_BYTES
2473	int
2474	default FUNCTION_PADDING_CFI if CFI_CLANG
2475	default FUNCTION_ALIGNMENT
2476
2477config CALL_PADDING
2478	def_bool n
2479	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2480	select FUNCTION_ALIGNMENT_16B
2481
2482config FINEIBT
2483	def_bool y
2484	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2485	select CALL_PADDING
2486
2487config HAVE_CALL_THUNKS
2488	def_bool y
2489	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2490
2491config CALL_THUNKS
2492	def_bool n
2493	select CALL_PADDING
2494
2495config PREFIX_SYMBOLS
2496	def_bool y
2497	depends on CALL_PADDING && !CFI_CLANG
2498
2499menuconfig SPECULATION_MITIGATIONS
2500	bool "Mitigations for speculative execution vulnerabilities"
2501	default y
2502	help
2503	  Say Y here to enable options which enable mitigations for
2504	  speculative execution hardware vulnerabilities.
2505
2506	  If you say N, all mitigations will be disabled. You really
2507	  should know what you are doing to say so.
2508
2509if SPECULATION_MITIGATIONS
2510
2511config PAGE_TABLE_ISOLATION
2512	bool "Remove the kernel mapping in user mode"
2513	default y
2514	depends on (X86_64 || X86_PAE)
2515	help
2516	  This feature reduces the number of hardware side channels by
2517	  ensuring that the majority of kernel addresses are not mapped
2518	  into userspace.
2519
2520	  See Documentation/arch/x86/pti.rst for more details.
2521
2522config RETPOLINE
2523	bool "Avoid speculative indirect branches in kernel"
2524	select OBJTOOL if HAVE_OBJTOOL
2525	default y
2526	help
2527	  Compile kernel with the retpoline compiler options to guard against
2528	  kernel-to-user data leaks by avoiding speculative indirect
2529	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2530	  support for full protection. The kernel may run slower.
2531
2532config RETHUNK
2533	bool "Enable return-thunks"
2534	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2535	select OBJTOOL if HAVE_OBJTOOL
2536	default y if X86_64
2537	help
2538	  Compile the kernel with the return-thunks compiler option to guard
2539	  against kernel-to-user data leaks by avoiding return speculation.
2540	  Requires a compiler with -mfunction-return=thunk-extern
2541	  support for full protection. The kernel may run slower.
2542
2543config CPU_UNRET_ENTRY
2544	bool "Enable UNRET on kernel entry"
2545	depends on CPU_SUP_AMD && RETHUNK && X86_64
2546	default y
2547	help
2548	  Compile the kernel with support for the retbleed=unret mitigation.
2549
2550config CALL_DEPTH_TRACKING
2551	bool "Mitigate RSB underflow with call depth tracking"
2552	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2553	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2554	select CALL_THUNKS
2555	default y
2556	help
2557	  Compile the kernel with call depth tracking to mitigate the Intel
2558	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2559	  mitigation is off by default and needs to be enabled on the
2560	  kernel command line via the retbleed=stuff option. For
2561	  non-affected systems the overhead of this option is marginal as
2562	  the call depth tracking is using run-time generated call thunks
2563	  in a compiler generated padding area and call patching. This
2564	  increases text size by ~5%. For non affected systems this space
2565	  is unused. On affected SKL systems this results in a significant
2566	  performance gain over the IBRS mitigation.
2567
2568config CALL_THUNKS_DEBUG
2569	bool "Enable call thunks and call depth tracking debugging"
2570	depends on CALL_DEPTH_TRACKING
2571	select FUNCTION_ALIGNMENT_32B
2572	default n
2573	help
2574	  Enable call/ret counters for imbalance detection and build in
2575	  a noisy dmesg about callthunks generation and call patching for
2576	  trouble shooting. The debug prints need to be enabled on the
2577	  kernel command line with 'debug-callthunks'.
2578	  Only enable this when you are debugging call thunks as this
2579	  creates a noticeable runtime overhead. If unsure say N.
2580
2581config CPU_IBPB_ENTRY
2582	bool "Enable IBPB on kernel entry"
2583	depends on CPU_SUP_AMD && X86_64
2584	default y
2585	help
2586	  Compile the kernel with support for the retbleed=ibpb mitigation.
2587
2588config CPU_IBRS_ENTRY
2589	bool "Enable IBRS on kernel entry"
2590	depends on CPU_SUP_INTEL && X86_64
2591	default y
2592	help
2593	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2594	  This mitigates both spectre_v2 and retbleed at great cost to
2595	  performance.
2596
2597config SLS
2598	bool "Mitigate Straight-Line-Speculation"
2599	depends on CC_HAS_SLS && X86_64
2600	select OBJTOOL if HAVE_OBJTOOL
2601	default n
2602	help
2603	  Compile the kernel with straight-line-speculation options to guard
2604	  against straight line speculation. The kernel image might be slightly
2605	  larger.
2606
2607endif
2608
2609config ARCH_HAS_ADD_PAGES
2610	def_bool y
2611	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2612
2613config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2614	def_bool y
2615
2616menu "Power management and ACPI options"
2617
2618config ARCH_HIBERNATION_HEADER
2619	def_bool y
2620	depends on HIBERNATION
2621
2622source "kernel/power/Kconfig"
2623
2624source "drivers/acpi/Kconfig"
2625
2626config X86_APM_BOOT
2627	def_bool y
2628	depends on APM
2629
2630menuconfig APM
2631	tristate "APM (Advanced Power Management) BIOS support"
2632	depends on X86_32 && PM_SLEEP
2633	help
2634	  APM is a BIOS specification for saving power using several different
2635	  techniques. This is mostly useful for battery powered laptops with
2636	  APM compliant BIOSes. If you say Y here, the system time will be
2637	  reset after a RESUME operation, the /proc/apm device will provide
2638	  battery status information, and user-space programs will receive
2639	  notification of APM "events" (e.g. battery status change).
2640
2641	  If you select "Y" here, you can disable actual use of the APM
2642	  BIOS by passing the "apm=off" option to the kernel at boot time.
2643
2644	  Note that the APM support is almost completely disabled for
2645	  machines with more than one CPU.
2646
2647	  In order to use APM, you will need supporting software. For location
2648	  and more information, read <file:Documentation/power/apm-acpi.rst>
2649	  and the Battery Powered Linux mini-HOWTO, available from
2650	  <http://www.tldp.org/docs.html#howto>.
2651
2652	  This driver does not spin down disk drives (see the hdparm(8)
2653	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2654	  VESA-compliant "green" monitors.
2655
2656	  This driver does not support the TI 4000M TravelMate and the ACER
2657	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2658	  desktop machines also don't have compliant BIOSes, and this driver
2659	  may cause those machines to panic during the boot phase.
2660
2661	  Generally, if you don't have a battery in your machine, there isn't
2662	  much point in using this driver and you should say N. If you get
2663	  random kernel OOPSes or reboots that don't seem to be related to
2664	  anything, try disabling/enabling this option (or disabling/enabling
2665	  APM in your BIOS).
2666
2667	  Some other things you should try when experiencing seemingly random,
2668	  "weird" problems:
2669
2670	  1) make sure that you have enough swap space and that it is
2671	  enabled.
2672	  2) pass the "idle=poll" option to the kernel
2673	  3) switch on floating point emulation in the kernel and pass
2674	  the "no387" option to the kernel
2675	  4) pass the "floppy=nodma" option to the kernel
2676	  5) pass the "mem=4M" option to the kernel (thereby disabling
2677	  all but the first 4 MB of RAM)
2678	  6) make sure that the CPU is not over clocked.
2679	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2680	  8) disable the cache from your BIOS settings
2681	  9) install a fan for the video card or exchange video RAM
2682	  10) install a better fan for the CPU
2683	  11) exchange RAM chips
2684	  12) exchange the motherboard.
2685
2686	  To compile this driver as a module, choose M here: the
2687	  module will be called apm.
2688
2689if APM
2690
2691config APM_IGNORE_USER_SUSPEND
2692	bool "Ignore USER SUSPEND"
2693	help
2694	  This option will ignore USER SUSPEND requests. On machines with a
2695	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2696	  series notebooks, it is necessary to say Y because of a BIOS bug.
2697
2698config APM_DO_ENABLE
2699	bool "Enable PM at boot time"
2700	help
2701	  Enable APM features at boot time. From page 36 of the APM BIOS
2702	  specification: "When disabled, the APM BIOS does not automatically
2703	  power manage devices, enter the Standby State, enter the Suspend
2704	  State, or take power saving steps in response to CPU Idle calls."
2705	  This driver will make CPU Idle calls when Linux is idle (unless this
2706	  feature is turned off -- see "Do CPU IDLE calls", below). This
2707	  should always save battery power, but more complicated APM features
2708	  will be dependent on your BIOS implementation. You may need to turn
2709	  this option off if your computer hangs at boot time when using APM
2710	  support, or if it beeps continuously instead of suspending. Turn
2711	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2712	  T400CDT. This is off by default since most machines do fine without
2713	  this feature.
2714
2715config APM_CPU_IDLE
2716	depends on CPU_IDLE
2717	bool "Make CPU Idle calls when idle"
2718	help
2719	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2720	  On some machines, this can activate improved power savings, such as
2721	  a slowed CPU clock rate, when the machine is idle. These idle calls
2722	  are made after the idle loop has run for some length of time (e.g.,
2723	  333 mS). On some machines, this will cause a hang at boot time or
2724	  whenever the CPU becomes idle. (On machines with more than one CPU,
2725	  this option does nothing.)
2726
2727config APM_DISPLAY_BLANK
2728	bool "Enable console blanking using APM"
2729	help
2730	  Enable console blanking using the APM. Some laptops can use this to
2731	  turn off the LCD backlight when the screen blanker of the Linux
2732	  virtual console blanks the screen. Note that this is only used by
2733	  the virtual console screen blanker, and won't turn off the backlight
2734	  when using the X Window system. This also doesn't have anything to
2735	  do with your VESA-compliant power-saving monitor. Further, this
2736	  option doesn't work for all laptops -- it might not turn off your
2737	  backlight at all, or it might print a lot of errors to the console,
2738	  especially if you are using gpm.
2739
2740config APM_ALLOW_INTS
2741	bool "Allow interrupts during APM BIOS calls"
2742	help
2743	  Normally we disable external interrupts while we are making calls to
2744	  the APM BIOS as a measure to lessen the effects of a badly behaving
2745	  BIOS implementation.  The BIOS should reenable interrupts if it
2746	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2747	  many of the newer IBM Thinkpads.  If you experience hangs when you
2748	  suspend, try setting this to Y.  Otherwise, say N.
2749
2750endif # APM
2751
2752source "drivers/cpufreq/Kconfig"
2753
2754source "drivers/cpuidle/Kconfig"
2755
2756source "drivers/idle/Kconfig"
2757
2758endmenu
2759
2760menu "Bus options (PCI etc.)"
2761
2762choice
2763	prompt "PCI access mode"
2764	depends on X86_32 && PCI
2765	default PCI_GOANY
2766	help
2767	  On PCI systems, the BIOS can be used to detect the PCI devices and
2768	  determine their configuration. However, some old PCI motherboards
2769	  have BIOS bugs and may crash if this is done. Also, some embedded
2770	  PCI-based systems don't have any BIOS at all. Linux can also try to
2771	  detect the PCI hardware directly without using the BIOS.
2772
2773	  With this option, you can specify how Linux should detect the
2774	  PCI devices. If you choose "BIOS", the BIOS will be used,
2775	  if you choose "Direct", the BIOS won't be used, and if you
2776	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2777	  If you choose "Any", the kernel will try MMCONFIG, then the
2778	  direct access method and falls back to the BIOS if that doesn't
2779	  work. If unsure, go with the default, which is "Any".
2780
2781config PCI_GOBIOS
2782	bool "BIOS"
2783
2784config PCI_GOMMCONFIG
2785	bool "MMConfig"
2786
2787config PCI_GODIRECT
2788	bool "Direct"
2789
2790config PCI_GOOLPC
2791	bool "OLPC XO-1"
2792	depends on OLPC
2793
2794config PCI_GOANY
2795	bool "Any"
2796
2797endchoice
2798
2799config PCI_BIOS
2800	def_bool y
2801	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2802
2803# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2804config PCI_DIRECT
2805	def_bool y
2806	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2807
2808config PCI_MMCONFIG
2809	bool "Support mmconfig PCI config space access" if X86_64
2810	default y
2811	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2812	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2813
2814config PCI_OLPC
2815	def_bool y
2816	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2817
2818config PCI_XEN
2819	def_bool y
2820	depends on PCI && XEN
2821
2822config MMCONF_FAM10H
2823	def_bool y
2824	depends on X86_64 && PCI_MMCONFIG && ACPI
2825
2826config PCI_CNB20LE_QUIRK
2827	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2828	depends on PCI
2829	help
2830	  Read the PCI windows out of the CNB20LE host bridge. This allows
2831	  PCI hotplug to work on systems with the CNB20LE chipset which do
2832	  not have ACPI.
2833
2834	  There's no public spec for this chipset, and this functionality
2835	  is known to be incomplete.
2836
2837	  You should say N unless you know you need this.
2838
2839config ISA_BUS
2840	bool "ISA bus support on modern systems" if EXPERT
2841	help
2842	  Expose ISA bus device drivers and options available for selection and
2843	  configuration. Enable this option if your target machine has an ISA
2844	  bus. ISA is an older system, displaced by PCI and newer bus
2845	  architectures -- if your target machine is modern, it probably does
2846	  not have an ISA bus.
2847
2848	  If unsure, say N.
2849
2850# x86_64 have no ISA slots, but can have ISA-style DMA.
2851config ISA_DMA_API
2852	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2853	default y
2854	help
2855	  Enables ISA-style DMA support for devices requiring such controllers.
2856	  If unsure, say Y.
2857
2858if X86_32
2859
2860config ISA
2861	bool "ISA support"
2862	help
2863	  Find out whether you have ISA slots on your motherboard.  ISA is the
2864	  name of a bus system, i.e. the way the CPU talks to the other stuff
2865	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2866	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2867	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2868
2869config SCx200
2870	tristate "NatSemi SCx200 support"
2871	help
2872	  This provides basic support for National Semiconductor's
2873	  (now AMD's) Geode processors.  The driver probes for the
2874	  PCI-IDs of several on-chip devices, so its a good dependency
2875	  for other scx200_* drivers.
2876
2877	  If compiled as a module, the driver is named scx200.
2878
2879config SCx200HR_TIMER
2880	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2881	depends on SCx200
2882	default y
2883	help
2884	  This driver provides a clocksource built upon the on-chip
2885	  27MHz high-resolution timer.  Its also a workaround for
2886	  NSC Geode SC-1100's buggy TSC, which loses time when the
2887	  processor goes idle (as is done by the scheduler).  The
2888	  other workaround is idle=poll boot option.
2889
2890config OLPC
2891	bool "One Laptop Per Child support"
2892	depends on !X86_PAE
2893	select GPIOLIB
2894	select OF
2895	select OF_PROMTREE
2896	select IRQ_DOMAIN
2897	select OLPC_EC
2898	help
2899	  Add support for detecting the unique features of the OLPC
2900	  XO hardware.
2901
2902config OLPC_XO1_PM
2903	bool "OLPC XO-1 Power Management"
2904	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2905	help
2906	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2907
2908config OLPC_XO1_RTC
2909	bool "OLPC XO-1 Real Time Clock"
2910	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2911	help
2912	  Add support for the XO-1 real time clock, which can be used as a
2913	  programmable wakeup source.
2914
2915config OLPC_XO1_SCI
2916	bool "OLPC XO-1 SCI extras"
2917	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2918	depends on INPUT=y
2919	select POWER_SUPPLY
2920	help
2921	  Add support for SCI-based features of the OLPC XO-1 laptop:
2922	   - EC-driven system wakeups
2923	   - Power button
2924	   - Ebook switch
2925	   - Lid switch
2926	   - AC adapter status updates
2927	   - Battery status updates
2928
2929config OLPC_XO15_SCI
2930	bool "OLPC XO-1.5 SCI extras"
2931	depends on OLPC && ACPI
2932	select POWER_SUPPLY
2933	help
2934	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2935	   - EC-driven system wakeups
2936	   - AC adapter status updates
2937	   - Battery status updates
2938
2939config ALIX
2940	bool "PCEngines ALIX System Support (LED setup)"
2941	select GPIOLIB
2942	help
2943	  This option enables system support for the PCEngines ALIX.
2944	  At present this just sets up LEDs for GPIO control on
2945	  ALIX2/3/6 boards.  However, other system specific setup should
2946	  get added here.
2947
2948	  Note: You must still enable the drivers for GPIO and LED support
2949	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2950
2951	  Note: You have to set alix.force=1 for boards with Award BIOS.
2952
2953config NET5501
2954	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2955	select GPIOLIB
2956	help
2957	  This option enables system support for the Soekris Engineering net5501.
2958
2959config GEOS
2960	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2961	select GPIOLIB
2962	depends on DMI
2963	help
2964	  This option enables system support for the Traverse Technologies GEOS.
2965
2966config TS5500
2967	bool "Technologic Systems TS-5500 platform support"
2968	depends on MELAN
2969	select CHECK_SIGNATURE
2970	select NEW_LEDS
2971	select LEDS_CLASS
2972	help
2973	  This option enables system support for the Technologic Systems TS-5500.
2974
2975endif # X86_32
2976
2977config AMD_NB
2978	def_bool y
2979	depends on CPU_SUP_AMD && PCI
2980
2981endmenu
2982
2983menu "Binary Emulations"
2984
2985config IA32_EMULATION
2986	bool "IA32 Emulation"
2987	depends on X86_64
2988	select ARCH_WANT_OLD_COMPAT_IPC
2989	select BINFMT_ELF
2990	select COMPAT_OLD_SIGACTION
2991	help
2992	  Include code to run legacy 32-bit programs under a
2993	  64-bit kernel. You should likely turn this on, unless you're
2994	  100% sure that you don't have any 32-bit programs left.
2995
2996config X86_X32_ABI
2997	bool "x32 ABI for 64-bit mode"
2998	depends on X86_64
2999	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3000	# compressed debug sections to x86_x32 properly:
3001	# https://github.com/ClangBuiltLinux/linux/issues/514
3002	# https://github.com/ClangBuiltLinux/linux/issues/1141
3003	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3004	help
3005	  Include code to run binaries for the x32 native 32-bit ABI
3006	  for 64-bit processors.  An x32 process gets access to the
3007	  full 64-bit register file and wide data path while leaving
3008	  pointers at 32 bits for smaller memory footprint.
3009
3010config COMPAT_32
3011	def_bool y
3012	depends on IA32_EMULATION || X86_32
3013	select HAVE_UID16
3014	select OLD_SIGSUSPEND3
3015
3016config COMPAT
3017	def_bool y
3018	depends on IA32_EMULATION || X86_X32_ABI
3019
3020config COMPAT_FOR_U64_ALIGNMENT
3021	def_bool y
3022	depends on COMPAT
3023
3024endmenu
3025
3026config HAVE_ATOMIC_IOMAP
3027	def_bool y
3028	depends on X86_32
3029
3030source "arch/x86/kvm/Kconfig"
3031
3032source "arch/x86/Kconfig.assembler"
3033