xref: /linux/arch/x86/Kconfig (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	help
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select GENERIC_VDSO_32
18	select HAVE_DEBUG_STACKOVERFLOW
19	select KMAP_LOCAL
20	select MODULES_USE_ELF_REL
21	select OLD_SIGACTION
22	select ARCH_SPLIT_ARG64
23
24config X86_64
25	def_bool y
26	depends on 64BIT
27	# Options that are inherently 64-bit kernel only:
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30	select ARCH_SUPPORTS_PER_VMA_LOCK
31	select HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37
38config FORCE_DYNAMIC_FTRACE
39	def_bool y
40	depends on X86_32
41	depends on FUNCTION_TRACER
42	select DYNAMIC_FTRACE
43	help
44	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45	  in order to test the non static function tracing in the
46	  generic code, as other architectures still use it. But we
47	  only need to keep it around for x86_64. No need to keep it
48	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53#   ported to 32-bit as well. )
54#
55config X86
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
61	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62	select ACPI_HOTPLUG_CPU			if ACPI_PROCESSOR && HOTPLUG_CPU
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_CPU_PASID		if IOMMU_SVA
76	select ARCH_HAS_CURRENT_STACK_POINTER
77	select ARCH_HAS_DEBUG_VIRTUAL
78	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
79	select ARCH_HAS_DEVMEM_IS_ALLOWED
80	select ARCH_HAS_EARLY_DEBUG		if KGDB
81	select ARCH_HAS_ELF_RANDOMIZE
82	select ARCH_HAS_FAST_MULTIPLIER
83	select ARCH_HAS_FORTIFY_SOURCE
84	select ARCH_HAS_GCOV_PROFILE_ALL
85	select ARCH_HAS_KCOV			if X86_64
86	select ARCH_HAS_MEM_ENCRYPT
87	select ARCH_HAS_MEMBARRIER_SYNC_CORE
88	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
89	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
90	select ARCH_HAS_PMEM_API		if X86_64
91	select ARCH_HAS_PTE_DEVMAP		if X86_64
92	select ARCH_HAS_PTE_SPECIAL
93	select ARCH_HAS_HW_PTE_YOUNG
94	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
95	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
96	select ARCH_HAS_COPY_MC			if X86_64
97	select ARCH_HAS_SET_MEMORY
98	select ARCH_HAS_SET_DIRECT_MAP
99	select ARCH_HAS_STRICT_KERNEL_RWX
100	select ARCH_HAS_STRICT_MODULE_RWX
101	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
102	select ARCH_HAS_SYSCALL_WRAPPER
103	select ARCH_HAS_UBSAN_SANITIZE_ALL
104	select ARCH_HAS_DEBUG_WX
105	select ARCH_HAS_ZONE_DMA_SET if EXPERT
106	select ARCH_HAVE_NMI_SAFE_CMPXCHG
107	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
108	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
109	select ARCH_MIGHT_HAVE_PC_PARPORT
110	select ARCH_MIGHT_HAVE_PC_SERIO
111	select ARCH_STACKWALK
112	select ARCH_SUPPORTS_ACPI
113	select ARCH_SUPPORTS_ATOMIC_RMW
114	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
115	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
116	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
117	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
118	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
119	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
120	select ARCH_SUPPORTS_LTO_CLANG
121	select ARCH_SUPPORTS_LTO_CLANG_THIN
122	select ARCH_USE_BUILTIN_BSWAP
123	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
124	select ARCH_USE_MEMTEST
125	select ARCH_USE_QUEUED_RWLOCKS
126	select ARCH_USE_QUEUED_SPINLOCKS
127	select ARCH_USE_SYM_ANNOTATIONS
128	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
129	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
130	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
131	select ARCH_WANTS_NO_INSTR
132	select ARCH_WANT_GENERAL_HUGETLB
133	select ARCH_WANT_HUGE_PMD_SHARE
134	select ARCH_WANT_LD_ORPHAN_WARN
135	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
136	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
137	select ARCH_WANTS_THP_SWAP		if X86_64
138	select ARCH_HAS_PARANOID_L1D_FLUSH
139	select BUILDTIME_TABLE_SORT
140	select CLKEVT_I8253
141	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
142	select CLOCKSOURCE_WATCHDOG
143	# Word-size accesses may read uninitialized data past the trailing \0
144	# in strings and cause false KMSAN reports.
145	select DCACHE_WORD_ACCESS		if !KMSAN
146	select DYNAMIC_SIGFRAME
147	select EDAC_ATOMIC_SCRUB
148	select EDAC_SUPPORT
149	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
150	select GENERIC_CLOCKEVENTS_MIN_ADJUST
151	select GENERIC_CMOS_UPDATE
152	select GENERIC_CPU_AUTOPROBE
153	select GENERIC_CPU_DEVICES
154	select GENERIC_CPU_VULNERABILITIES
155	select GENERIC_EARLY_IOREMAP
156	select GENERIC_ENTRY
157	select GENERIC_IOMAP
158	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
159	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
160	select GENERIC_IRQ_MIGRATION		if SMP
161	select GENERIC_IRQ_PROBE
162	select GENERIC_IRQ_RESERVATION_MODE
163	select GENERIC_IRQ_SHOW
164	select GENERIC_PENDING_IRQ		if SMP
165	select GENERIC_PTDUMP
166	select GENERIC_SMP_IDLE_THREAD
167	select GENERIC_TIME_VSYSCALL
168	select GENERIC_GETTIMEOFDAY
169	select GENERIC_VDSO_TIME_NS
170	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
171	select HARDIRQS_SW_RESEND
172	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
173	select HAS_IOPORT
174	select HAVE_ACPI_APEI			if ACPI
175	select HAVE_ACPI_APEI_NMI		if ACPI
176	select HAVE_ALIGNED_STRUCT_PAGE
177	select HAVE_ARCH_AUDITSYSCALL
178	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
179	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
180	select HAVE_ARCH_JUMP_LABEL
181	select HAVE_ARCH_JUMP_LABEL_RELATIVE
182	select HAVE_ARCH_KASAN			if X86_64
183	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
184	select HAVE_ARCH_KFENCE
185	select HAVE_ARCH_KMSAN			if X86_64
186	select HAVE_ARCH_KGDB
187	select HAVE_ARCH_MMAP_RND_BITS		if MMU
188	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
189	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
190	select HAVE_ARCH_PREL32_RELOCATIONS
191	select HAVE_ARCH_SECCOMP_FILTER
192	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
193	select HAVE_ARCH_STACKLEAK
194	select HAVE_ARCH_TRACEHOOK
195	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
196	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
197	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
198	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
199	select HAVE_ARCH_VMAP_STACK		if X86_64
200	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
201	select HAVE_ARCH_WITHIN_STACK_FRAMES
202	select HAVE_ASM_MODVERSIONS
203	select HAVE_CMPXCHG_DOUBLE
204	select HAVE_CMPXCHG_LOCAL
205	select HAVE_CONTEXT_TRACKING_USER		if X86_64
206	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
207	select HAVE_C_RECORDMCOUNT
208	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
209	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
210	select HAVE_BUILDTIME_MCOUNT_SORT
211	select HAVE_DEBUG_KMEMLEAK
212	select HAVE_DMA_CONTIGUOUS
213	select HAVE_DYNAMIC_FTRACE
214	select HAVE_DYNAMIC_FTRACE_WITH_REGS
215	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
216	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
217	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
218	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
219	select HAVE_EBPF_JIT
220	select HAVE_EFFICIENT_UNALIGNED_ACCESS
221	select HAVE_EISA
222	select HAVE_EXIT_THREAD
223	select HAVE_FAST_GUP
224	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
225	select HAVE_FTRACE_MCOUNT_RECORD
226	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
227	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
228	select HAVE_FUNCTION_TRACER
229	select HAVE_GCC_PLUGINS
230	select HAVE_HW_BREAKPOINT
231	select HAVE_IOREMAP_PROT
232	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
233	select HAVE_IRQ_TIME_ACCOUNTING
234	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
235	select HAVE_KERNEL_BZIP2
236	select HAVE_KERNEL_GZIP
237	select HAVE_KERNEL_LZ4
238	select HAVE_KERNEL_LZMA
239	select HAVE_KERNEL_LZO
240	select HAVE_KERNEL_XZ
241	select HAVE_KERNEL_ZSTD
242	select HAVE_KPROBES
243	select HAVE_KPROBES_ON_FTRACE
244	select HAVE_FUNCTION_ERROR_INJECTION
245	select HAVE_KRETPROBES
246	select HAVE_RETHOOK
247	select HAVE_KVM
248	select HAVE_LIVEPATCH			if X86_64
249	select HAVE_MIXED_BREAKPOINTS_REGS
250	select HAVE_MOD_ARCH_SPECIFIC
251	select HAVE_MOVE_PMD
252	select HAVE_MOVE_PUD
253	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
254	select HAVE_NMI
255	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
256	select HAVE_OBJTOOL			if X86_64
257	select HAVE_OPTPROBES
258	select HAVE_PCSPKR_PLATFORM
259	select HAVE_PERF_EVENTS
260	select HAVE_PERF_EVENTS_NMI
261	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
262	select HAVE_PCI
263	select HAVE_PERF_REGS
264	select HAVE_PERF_USER_STACK_DUMP
265	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
266	select MMU_GATHER_MERGE_VMAS
267	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
268	select HAVE_REGS_AND_STACK_ACCESS_API
269	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
270	select HAVE_FUNCTION_ARG_ACCESS_API
271	select HAVE_SETUP_PER_CPU_AREA
272	select HAVE_SOFTIRQ_ON_OWN_STACK
273	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
274	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
275	select HAVE_STATIC_CALL
276	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
277	select HAVE_PREEMPT_DYNAMIC_CALL
278	select HAVE_RSEQ
279	select HAVE_RUST			if X86_64
280	select HAVE_SYSCALL_TRACEPOINTS
281	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
282	select HAVE_UNSTABLE_SCHED_CLOCK
283	select HAVE_USER_RETURN_NOTIFIER
284	select HAVE_GENERIC_VDSO
285	select HOTPLUG_PARALLEL			if SMP && X86_64
286	select HOTPLUG_SMT			if SMP
287	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
288	select IRQ_FORCED_THREADING
289	select LOCK_MM_AND_FIND_VMA
290	select NEED_PER_CPU_EMBED_FIRST_CHUNK
291	select NEED_PER_CPU_PAGE_FIRST_CHUNK
292	select NEED_SG_DMA_LENGTH
293	select PCI_DOMAINS			if PCI
294	select PCI_LOCKLESS_CONFIG		if PCI
295	select PERF_EVENTS
296	select RTC_LIB
297	select RTC_MC146818_LIB
298	select SPARSE_IRQ
299	select SYSCTL_EXCEPTION_TRACE
300	select THREAD_INFO_IN_TASK
301	select TRACE_IRQFLAGS_SUPPORT
302	select TRACE_IRQFLAGS_NMI_SUPPORT
303	select USER_STACKTRACE_SUPPORT
304	select HAVE_ARCH_KCSAN			if X86_64
305	select PROC_PID_ARCH_STATUS		if PROC_FS
306	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
307	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
308	select FUNCTION_ALIGNMENT_4B
309	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
310	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
311
312config INSTRUCTION_DECODER
313	def_bool y
314	depends on KPROBES || PERF_EVENTS || UPROBES
315
316config OUTPUT_FORMAT
317	string
318	default "elf32-i386" if X86_32
319	default "elf64-x86-64" if X86_64
320
321config LOCKDEP_SUPPORT
322	def_bool y
323
324config STACKTRACE_SUPPORT
325	def_bool y
326
327config MMU
328	def_bool y
329
330config ARCH_MMAP_RND_BITS_MIN
331	default 28 if 64BIT
332	default 8
333
334config ARCH_MMAP_RND_BITS_MAX
335	default 32 if 64BIT
336	default 16
337
338config ARCH_MMAP_RND_COMPAT_BITS_MIN
339	default 8
340
341config ARCH_MMAP_RND_COMPAT_BITS_MAX
342	default 16
343
344config SBUS
345	bool
346
347config GENERIC_ISA_DMA
348	def_bool y
349	depends on ISA_DMA_API
350
351config GENERIC_CSUM
352	bool
353	default y if KMSAN || KASAN
354
355config GENERIC_BUG
356	def_bool y
357	depends on BUG
358	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
359
360config GENERIC_BUG_RELATIVE_POINTERS
361	bool
362
363config ARCH_MAY_HAVE_PC_FDC
364	def_bool y
365	depends on ISA_DMA_API
366
367config GENERIC_CALIBRATE_DELAY
368	def_bool y
369
370config ARCH_HAS_CPU_RELAX
371	def_bool y
372
373config ARCH_HIBERNATION_POSSIBLE
374	def_bool y
375
376config ARCH_SUSPEND_POSSIBLE
377	def_bool y
378
379config AUDIT_ARCH
380	def_bool y if X86_64
381
382config KASAN_SHADOW_OFFSET
383	hex
384	depends on KASAN
385	default 0xdffffc0000000000
386
387config HAVE_INTEL_TXT
388	def_bool y
389	depends on INTEL_IOMMU && ACPI
390
391config X86_64_SMP
392	def_bool y
393	depends on X86_64 && SMP
394
395config ARCH_SUPPORTS_UPROBES
396	def_bool y
397
398config FIX_EARLYCON_MEM
399	def_bool y
400
401config DYNAMIC_PHYSICAL_MASK
402	bool
403
404config PGTABLE_LEVELS
405	int
406	default 5 if X86_5LEVEL
407	default 4 if X86_64
408	default 3 if X86_PAE
409	default 2
410
411config CC_HAS_SANE_STACKPROTECTOR
412	bool
413	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
414	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
415	help
416	  We have to make sure stack protector is unconditionally disabled if
417	  the compiler produces broken code or if it does not let us control
418	  the segment on 32-bit kernels.
419
420menu "Processor type and features"
421
422config SMP
423	bool "Symmetric multi-processing support"
424	help
425	  This enables support for systems with more than one CPU. If you have
426	  a system with only one CPU, say N. If you have a system with more
427	  than one CPU, say Y.
428
429	  If you say N here, the kernel will run on uni- and multiprocessor
430	  machines, but will use only one CPU of a multiprocessor machine. If
431	  you say Y here, the kernel will run on many, but not all,
432	  uniprocessor machines. On a uniprocessor machine, the kernel
433	  will run faster if you say N here.
434
435	  Note that if you say Y here and choose architecture "586" or
436	  "Pentium" under "Processor family", the kernel will not work on 486
437	  architectures. Similarly, multiprocessor kernels for the "PPro"
438	  architecture may not work on all Pentium based boards.
439
440	  People using multiprocessor machines who say Y here should also say
441	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
442	  Management" code will be disabled if you say Y here.
443
444	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
445	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
446	  <http://www.tldp.org/docs.html#howto>.
447
448	  If you don't know what to do here, say N.
449
450config X86_X2APIC
451	bool "Support x2apic"
452	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
453	help
454	  This enables x2apic support on CPUs that have this feature.
455
456	  This allows 32-bit apic IDs (so it can support very large systems),
457	  and accesses the local apic via MSRs not via mmio.
458
459	  Some Intel systems circa 2022 and later are locked into x2APIC mode
460	  and can not fall back to the legacy APIC modes if SGX or TDX are
461	  enabled in the BIOS. They will boot with very reduced functionality
462	  without enabling this option.
463
464	  If you don't know what to do here, say N.
465
466config X86_MPPARSE
467	bool "Enable MPS table" if ACPI
468	default y
469	depends on X86_LOCAL_APIC
470	help
471	  For old smp systems that do not have proper acpi support. Newer systems
472	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
473
474config GOLDFISH
475	def_bool y
476	depends on X86_GOLDFISH
477
478config X86_CPU_RESCTRL
479	bool "x86 CPU resource control support"
480	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
481	select KERNFS
482	select PROC_CPU_RESCTRL		if PROC_FS
483	help
484	  Enable x86 CPU resource control support.
485
486	  Provide support for the allocation and monitoring of system resources
487	  usage by the CPU.
488
489	  Intel calls this Intel Resource Director Technology
490	  (Intel(R) RDT). More information about RDT can be found in the
491	  Intel x86 Architecture Software Developer Manual.
492
493	  AMD calls this AMD Platform Quality of Service (AMD QoS).
494	  More information about AMD QoS can be found in the AMD64 Technology
495	  Platform Quality of Service Extensions manual.
496
497	  Say N if unsure.
498
499if X86_32
500config X86_BIGSMP
501	bool "Support for big SMP systems with more than 8 CPUs"
502	depends on SMP
503	help
504	  This option is needed for the systems that have more than 8 CPUs.
505
506config X86_EXTENDED_PLATFORM
507	bool "Support for extended (non-PC) x86 platforms"
508	default y
509	help
510	  If you disable this option then the kernel will only support
511	  standard PC platforms. (which covers the vast majority of
512	  systems out there.)
513
514	  If you enable this option then you'll be able to select support
515	  for the following (non-PC) 32 bit x86 platforms:
516		Goldfish (Android emulator)
517		AMD Elan
518		RDC R-321x SoC
519		SGI 320/540 (Visual Workstation)
520		STA2X11-based (e.g. Northville)
521		Moorestown MID devices
522
523	  If you have one of these systems, or if you want to build a
524	  generic distribution kernel, say Y here - otherwise say N.
525endif # X86_32
526
527if X86_64
528config X86_EXTENDED_PLATFORM
529	bool "Support for extended (non-PC) x86 platforms"
530	default y
531	help
532	  If you disable this option then the kernel will only support
533	  standard PC platforms. (which covers the vast majority of
534	  systems out there.)
535
536	  If you enable this option then you'll be able to select support
537	  for the following (non-PC) 64 bit x86 platforms:
538		Numascale NumaChip
539		ScaleMP vSMP
540		SGI Ultraviolet
541
542	  If you have one of these systems, or if you want to build a
543	  generic distribution kernel, say Y here - otherwise say N.
544endif # X86_64
545# This is an alphabetically sorted list of 64 bit extended platforms
546# Please maintain the alphabetic order if and when there are additions
547config X86_NUMACHIP
548	bool "Numascale NumaChip"
549	depends on X86_64
550	depends on X86_EXTENDED_PLATFORM
551	depends on NUMA
552	depends on SMP
553	depends on X86_X2APIC
554	depends on PCI_MMCONFIG
555	help
556	  Adds support for Numascale NumaChip large-SMP systems. Needed to
557	  enable more than ~168 cores.
558	  If you don't have one of these, you should say N here.
559
560config X86_VSMP
561	bool "ScaleMP vSMP"
562	select HYPERVISOR_GUEST
563	select PARAVIRT
564	depends on X86_64 && PCI
565	depends on X86_EXTENDED_PLATFORM
566	depends on SMP
567	help
568	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
569	  supposed to run on these EM64T-based machines.  Only choose this option
570	  if you have one of these machines.
571
572config X86_UV
573	bool "SGI Ultraviolet"
574	depends on X86_64
575	depends on X86_EXTENDED_PLATFORM
576	depends on NUMA
577	depends on EFI
578	depends on KEXEC_CORE
579	depends on X86_X2APIC
580	depends on PCI
581	help
582	  This option is needed in order to support SGI Ultraviolet systems.
583	  If you don't have one of these, you should say N here.
584
585# Following is an alphabetically sorted list of 32 bit extended platforms
586# Please maintain the alphabetic order if and when there are additions
587
588config X86_GOLDFISH
589	bool "Goldfish (Virtual Platform)"
590	depends on X86_EXTENDED_PLATFORM
591	help
592	  Enable support for the Goldfish virtual platform used primarily
593	  for Android development. Unless you are building for the Android
594	  Goldfish emulator say N here.
595
596config X86_INTEL_CE
597	bool "CE4100 TV platform"
598	depends on PCI
599	depends on PCI_GODIRECT
600	depends on X86_IO_APIC
601	depends on X86_32
602	depends on X86_EXTENDED_PLATFORM
603	select X86_REBOOTFIXUPS
604	select OF
605	select OF_EARLY_FLATTREE
606	help
607	  Select for the Intel CE media processor (CE4100) SOC.
608	  This option compiles in support for the CE4100 SOC for settop
609	  boxes and media devices.
610
611config X86_INTEL_MID
612	bool "Intel MID platform support"
613	depends on X86_EXTENDED_PLATFORM
614	depends on X86_PLATFORM_DEVICES
615	depends on PCI
616	depends on X86_64 || (PCI_GOANY && X86_32)
617	depends on X86_IO_APIC
618	select I2C
619	select DW_APB_TIMER
620	select INTEL_SCU_PCI
621	help
622	  Select to build a kernel capable of supporting Intel MID (Mobile
623	  Internet Device) platform systems which do not have the PCI legacy
624	  interfaces. If you are building for a PC class system say N here.
625
626	  Intel MID platforms are based on an Intel processor and chipset which
627	  consume less power than most of the x86 derivatives.
628
629config X86_INTEL_QUARK
630	bool "Intel Quark platform support"
631	depends on X86_32
632	depends on X86_EXTENDED_PLATFORM
633	depends on X86_PLATFORM_DEVICES
634	depends on X86_TSC
635	depends on PCI
636	depends on PCI_GOANY
637	depends on X86_IO_APIC
638	select IOSF_MBI
639	select INTEL_IMR
640	select COMMON_CLK
641	help
642	  Select to include support for Quark X1000 SoC.
643	  Say Y here if you have a Quark based system such as the Arduino
644	  compatible Intel Galileo.
645
646config X86_INTEL_LPSS
647	bool "Intel Low Power Subsystem Support"
648	depends on X86 && ACPI && PCI
649	select COMMON_CLK
650	select PINCTRL
651	select IOSF_MBI
652	help
653	  Select to build support for Intel Low Power Subsystem such as
654	  found on Intel Lynxpoint PCH. Selecting this option enables
655	  things like clock tree (common clock framework) and pincontrol
656	  which are needed by the LPSS peripheral drivers.
657
658config X86_AMD_PLATFORM_DEVICE
659	bool "AMD ACPI2Platform devices support"
660	depends on ACPI
661	select COMMON_CLK
662	select PINCTRL
663	help
664	  Select to interpret AMD specific ACPI device to platform device
665	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
666	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
667	  implemented under PINCTRL subsystem.
668
669config IOSF_MBI
670	tristate "Intel SoC IOSF Sideband support for SoC platforms"
671	depends on PCI
672	help
673	  This option enables sideband register access support for Intel SoC
674	  platforms. On these platforms the IOSF sideband is used in lieu of
675	  MSR's for some register accesses, mostly but not limited to thermal
676	  and power. Drivers may query the availability of this device to
677	  determine if they need the sideband in order to work on these
678	  platforms. The sideband is available on the following SoC products.
679	  This list is not meant to be exclusive.
680	   - BayTrail
681	   - Braswell
682	   - Quark
683
684	  You should say Y if you are running a kernel on one of these SoC's.
685
686config IOSF_MBI_DEBUG
687	bool "Enable IOSF sideband access through debugfs"
688	depends on IOSF_MBI && DEBUG_FS
689	help
690	  Select this option to expose the IOSF sideband access registers (MCR,
691	  MDR, MCRX) through debugfs to write and read register information from
692	  different units on the SoC. This is most useful for obtaining device
693	  state information for debug and analysis. As this is a general access
694	  mechanism, users of this option would have specific knowledge of the
695	  device they want to access.
696
697	  If you don't require the option or are in doubt, say N.
698
699config X86_RDC321X
700	bool "RDC R-321x SoC"
701	depends on X86_32
702	depends on X86_EXTENDED_PLATFORM
703	select M486
704	select X86_REBOOTFIXUPS
705	help
706	  This option is needed for RDC R-321x system-on-chip, also known
707	  as R-8610-(G).
708	  If you don't have one of these chips, you should say N here.
709
710config X86_32_NON_STANDARD
711	bool "Support non-standard 32-bit SMP architectures"
712	depends on X86_32 && SMP
713	depends on X86_EXTENDED_PLATFORM
714	help
715	  This option compiles in the bigsmp and STA2X11 default
716	  subarchitectures.  It is intended for a generic binary
717	  kernel. If you select them all, kernel will probe it one by
718	  one and will fallback to default.
719
720# Alphabetically sorted list of Non standard 32 bit platforms
721
722config X86_SUPPORTS_MEMORY_FAILURE
723	def_bool y
724	# MCE code calls memory_failure():
725	depends on X86_MCE
726	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
727	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
728	depends on X86_64 || !SPARSEMEM
729	select ARCH_SUPPORTS_MEMORY_FAILURE
730
731config STA2X11
732	bool "STA2X11 Companion Chip Support"
733	depends on X86_32_NON_STANDARD && PCI
734	select SWIOTLB
735	select MFD_STA2X11
736	select GPIOLIB
737	help
738	  This adds support for boards based on the STA2X11 IO-Hub,
739	  a.k.a. "ConneXt". The chip is used in place of the standard
740	  PC chipset, so all "standard" peripherals are missing. If this
741	  option is selected the kernel will still be able to boot on
742	  standard PC machines.
743
744config X86_32_IRIS
745	tristate "Eurobraille/Iris poweroff module"
746	depends on X86_32
747	help
748	  The Iris machines from EuroBraille do not have APM or ACPI support
749	  to shut themselves down properly.  A special I/O sequence is
750	  needed to do so, which is what this module does at
751	  kernel shutdown.
752
753	  This is only for Iris machines from EuroBraille.
754
755	  If unused, say N.
756
757config SCHED_OMIT_FRAME_POINTER
758	def_bool y
759	prompt "Single-depth WCHAN output"
760	depends on X86
761	help
762	  Calculate simpler /proc/<PID>/wchan values. If this option
763	  is disabled then wchan values will recurse back to the
764	  caller function. This provides more accurate wchan values,
765	  at the expense of slightly more scheduling overhead.
766
767	  If in doubt, say "Y".
768
769menuconfig HYPERVISOR_GUEST
770	bool "Linux guest support"
771	help
772	  Say Y here to enable options for running Linux under various hyper-
773	  visors. This option enables basic hypervisor detection and platform
774	  setup.
775
776	  If you say N, all options in this submenu will be skipped and
777	  disabled, and Linux guest support won't be built in.
778
779if HYPERVISOR_GUEST
780
781config PARAVIRT
782	bool "Enable paravirtualization code"
783	depends on HAVE_STATIC_CALL
784	help
785	  This changes the kernel so it can modify itself when it is run
786	  under a hypervisor, potentially improving performance significantly
787	  over full virtualization.  However, when run without a hypervisor
788	  the kernel is theoretically slower and slightly larger.
789
790config PARAVIRT_XXL
791	bool
792
793config PARAVIRT_DEBUG
794	bool "paravirt-ops debugging"
795	depends on PARAVIRT && DEBUG_KERNEL
796	help
797	  Enable to debug paravirt_ops internals.  Specifically, BUG if
798	  a paravirt_op is missing when it is called.
799
800config PARAVIRT_SPINLOCKS
801	bool "Paravirtualization layer for spinlocks"
802	depends on PARAVIRT && SMP
803	help
804	  Paravirtualized spinlocks allow a pvops backend to replace the
805	  spinlock implementation with something virtualization-friendly
806	  (for example, block the virtual CPU rather than spinning).
807
808	  It has a minimal impact on native kernels and gives a nice performance
809	  benefit on paravirtualized KVM / Xen kernels.
810
811	  If you are unsure how to answer this question, answer Y.
812
813config X86_HV_CALLBACK_VECTOR
814	def_bool n
815
816source "arch/x86/xen/Kconfig"
817
818config KVM_GUEST
819	bool "KVM Guest support (including kvmclock)"
820	depends on PARAVIRT
821	select PARAVIRT_CLOCK
822	select ARCH_CPUIDLE_HALTPOLL
823	select X86_HV_CALLBACK_VECTOR
824	default y
825	help
826	  This option enables various optimizations for running under the KVM
827	  hypervisor. It includes a paravirtualized clock, so that instead
828	  of relying on a PIT (or probably other) emulation by the
829	  underlying device model, the host provides the guest with
830	  timing infrastructure such as time of day, and system time
831
832config ARCH_CPUIDLE_HALTPOLL
833	def_bool n
834	prompt "Disable host haltpoll when loading haltpoll driver"
835	help
836	  If virtualized under KVM, disable host haltpoll.
837
838config PVH
839	bool "Support for running PVH guests"
840	help
841	  This option enables the PVH entry point for guest virtual machines
842	  as specified in the x86/HVM direct boot ABI.
843
844config PARAVIRT_TIME_ACCOUNTING
845	bool "Paravirtual steal time accounting"
846	depends on PARAVIRT
847	help
848	  Select this option to enable fine granularity task steal time
849	  accounting. Time spent executing other tasks in parallel with
850	  the current vCPU is discounted from the vCPU power. To account for
851	  that, there can be a small performance impact.
852
853	  If in doubt, say N here.
854
855config PARAVIRT_CLOCK
856	bool
857
858config JAILHOUSE_GUEST
859	bool "Jailhouse non-root cell support"
860	depends on X86_64 && PCI
861	select X86_PM_TIMER
862	help
863	  This option allows to run Linux as guest in a Jailhouse non-root
864	  cell. You can leave this option disabled if you only want to start
865	  Jailhouse and run Linux afterwards in the root cell.
866
867config ACRN_GUEST
868	bool "ACRN Guest support"
869	depends on X86_64
870	select X86_HV_CALLBACK_VECTOR
871	help
872	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
873	  a flexible, lightweight reference open-source hypervisor, built with
874	  real-time and safety-criticality in mind. It is built for embedded
875	  IOT with small footprint and real-time features. More details can be
876	  found in https://projectacrn.org/.
877
878config INTEL_TDX_GUEST
879	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
880	depends on X86_64 && CPU_SUP_INTEL
881	depends on X86_X2APIC
882	depends on EFI_STUB
883	select ARCH_HAS_CC_PLATFORM
884	select X86_MEM_ENCRYPT
885	select X86_MCE
886	select UNACCEPTED_MEMORY
887	help
888	  Support running as a guest under Intel TDX.  Without this support,
889	  the guest kernel can not boot or run under TDX.
890	  TDX includes memory encryption and integrity capabilities
891	  which protect the confidentiality and integrity of guest
892	  memory contents and CPU state. TDX guests are protected from
893	  some attacks from the VMM.
894
895endif # HYPERVISOR_GUEST
896
897source "arch/x86/Kconfig.cpu"
898
899config HPET_TIMER
900	def_bool X86_64
901	prompt "HPET Timer Support" if X86_32
902	help
903	  Use the IA-PC HPET (High Precision Event Timer) to manage
904	  time in preference to the PIT and RTC, if a HPET is
905	  present.
906	  HPET is the next generation timer replacing legacy 8254s.
907	  The HPET provides a stable time base on SMP
908	  systems, unlike the TSC, but it is more expensive to access,
909	  as it is off-chip.  The interface used is documented
910	  in the HPET spec, revision 1.
911
912	  You can safely choose Y here.  However, HPET will only be
913	  activated if the platform and the BIOS support this feature.
914	  Otherwise the 8254 will be used for timing services.
915
916	  Choose N to continue using the legacy 8254 timer.
917
918config HPET_EMULATE_RTC
919	def_bool y
920	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
921
922# Mark as expert because too many people got it wrong.
923# The code disables itself when not needed.
924config DMI
925	default y
926	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
927	bool "Enable DMI scanning" if EXPERT
928	help
929	  Enabled scanning of DMI to identify machine quirks. Say Y
930	  here unless you have verified that your setup is not
931	  affected by entries in the DMI blacklist. Required by PNP
932	  BIOS code.
933
934config GART_IOMMU
935	bool "Old AMD GART IOMMU support"
936	select DMA_OPS
937	select IOMMU_HELPER
938	select SWIOTLB
939	depends on X86_64 && PCI && AMD_NB
940	help
941	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
942	  GART based hardware IOMMUs.
943
944	  The GART supports full DMA access for devices with 32-bit access
945	  limitations, on systems with more than 3 GB. This is usually needed
946	  for USB, sound, many IDE/SATA chipsets and some other devices.
947
948	  Newer systems typically have a modern AMD IOMMU, supported via
949	  the CONFIG_AMD_IOMMU=y config option.
950
951	  In normal configurations this driver is only active when needed:
952	  there's more than 3 GB of memory and the system contains a
953	  32-bit limited device.
954
955	  If unsure, say Y.
956
957config BOOT_VESA_SUPPORT
958	bool
959	help
960	  If true, at least one selected framebuffer driver can take advantage
961	  of VESA video modes set at an early boot stage via the vga= parameter.
962
963config MAXSMP
964	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
965	depends on X86_64 && SMP && DEBUG_KERNEL
966	select CPUMASK_OFFSTACK
967	help
968	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
969	  If unsure, say N.
970
971#
972# The maximum number of CPUs supported:
973#
974# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
975# and which can be configured interactively in the
976# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
977#
978# The ranges are different on 32-bit and 64-bit kernels, depending on
979# hardware capabilities and scalability features of the kernel.
980#
981# ( If MAXSMP is enabled we just use the highest possible value and disable
982#   interactive configuration. )
983#
984
985config NR_CPUS_RANGE_BEGIN
986	int
987	default NR_CPUS_RANGE_END if MAXSMP
988	default    1 if !SMP
989	default    2
990
991config NR_CPUS_RANGE_END
992	int
993	depends on X86_32
994	default   64 if  SMP &&  X86_BIGSMP
995	default    8 if  SMP && !X86_BIGSMP
996	default    1 if !SMP
997
998config NR_CPUS_RANGE_END
999	int
1000	depends on X86_64
1001	default 8192 if  SMP && CPUMASK_OFFSTACK
1002	default  512 if  SMP && !CPUMASK_OFFSTACK
1003	default    1 if !SMP
1004
1005config NR_CPUS_DEFAULT
1006	int
1007	depends on X86_32
1008	default   32 if  X86_BIGSMP
1009	default    8 if  SMP
1010	default    1 if !SMP
1011
1012config NR_CPUS_DEFAULT
1013	int
1014	depends on X86_64
1015	default 8192 if  MAXSMP
1016	default   64 if  SMP
1017	default    1 if !SMP
1018
1019config NR_CPUS
1020	int "Maximum number of CPUs" if SMP && !MAXSMP
1021	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1022	default NR_CPUS_DEFAULT
1023	help
1024	  This allows you to specify the maximum number of CPUs which this
1025	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1026	  supported value is 8192, otherwise the maximum value is 512.  The
1027	  minimum value which makes sense is 2.
1028
1029	  This is purely to save memory: each supported CPU adds about 8KB
1030	  to the kernel image.
1031
1032config SCHED_CLUSTER
1033	bool "Cluster scheduler support"
1034	depends on SMP
1035	default y
1036	help
1037	  Cluster scheduler support improves the CPU scheduler's decision
1038	  making when dealing with machines that have clusters of CPUs.
1039	  Cluster usually means a couple of CPUs which are placed closely
1040	  by sharing mid-level caches, last-level cache tags or internal
1041	  busses.
1042
1043config SCHED_SMT
1044	def_bool y if SMP
1045
1046config SCHED_MC
1047	def_bool y
1048	prompt "Multi-core scheduler support"
1049	depends on SMP
1050	help
1051	  Multi-core scheduler support improves the CPU scheduler's decision
1052	  making when dealing with multi-core CPU chips at a cost of slightly
1053	  increased overhead in some places. If unsure say N here.
1054
1055config SCHED_MC_PRIO
1056	bool "CPU core priorities scheduler support"
1057	depends on SCHED_MC && CPU_SUP_INTEL
1058	select X86_INTEL_PSTATE
1059	select CPU_FREQ
1060	default y
1061	help
1062	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1063	  core ordering determined at manufacturing time, which allows
1064	  certain cores to reach higher turbo frequencies (when running
1065	  single threaded workloads) than others.
1066
1067	  Enabling this kernel feature teaches the scheduler about
1068	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1069	  scheduler's CPU selection logic accordingly, so that higher
1070	  overall system performance can be achieved.
1071
1072	  This feature will have no effect on CPUs without this feature.
1073
1074	  If unsure say Y here.
1075
1076config UP_LATE_INIT
1077	def_bool y
1078	depends on !SMP && X86_LOCAL_APIC
1079
1080config X86_UP_APIC
1081	bool "Local APIC support on uniprocessors" if !PCI_MSI
1082	default PCI_MSI
1083	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1084	help
1085	  A local APIC (Advanced Programmable Interrupt Controller) is an
1086	  integrated interrupt controller in the CPU. If you have a single-CPU
1087	  system which has a processor with a local APIC, you can say Y here to
1088	  enable and use it. If you say Y here even though your machine doesn't
1089	  have a local APIC, then the kernel will still run with no slowdown at
1090	  all. The local APIC supports CPU-generated self-interrupts (timer,
1091	  performance counters), and the NMI watchdog which detects hard
1092	  lockups.
1093
1094config X86_UP_IOAPIC
1095	bool "IO-APIC support on uniprocessors"
1096	depends on X86_UP_APIC
1097	help
1098	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1099	  SMP-capable replacement for PC-style interrupt controllers. Most
1100	  SMP systems and many recent uniprocessor systems have one.
1101
1102	  If you have a single-CPU system with an IO-APIC, you can say Y here
1103	  to use it. If you say Y here even though your machine doesn't have
1104	  an IO-APIC, then the kernel will still run with no slowdown at all.
1105
1106config X86_LOCAL_APIC
1107	def_bool y
1108	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1109	select IRQ_DOMAIN_HIERARCHY
1110
1111config X86_IO_APIC
1112	def_bool y
1113	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1114
1115config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1116	bool "Reroute for broken boot IRQs"
1117	depends on X86_IO_APIC
1118	help
1119	  This option enables a workaround that fixes a source of
1120	  spurious interrupts. This is recommended when threaded
1121	  interrupt handling is used on systems where the generation of
1122	  superfluous "boot interrupts" cannot be disabled.
1123
1124	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1125	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1126	  kernel does during interrupt handling). On chipsets where this
1127	  boot IRQ generation cannot be disabled, this workaround keeps
1128	  the original IRQ line masked so that only the equivalent "boot
1129	  IRQ" is delivered to the CPUs. The workaround also tells the
1130	  kernel to set up the IRQ handler on the boot IRQ line. In this
1131	  way only one interrupt is delivered to the kernel. Otherwise
1132	  the spurious second interrupt may cause the kernel to bring
1133	  down (vital) interrupt lines.
1134
1135	  Only affects "broken" chipsets. Interrupt sharing may be
1136	  increased on these systems.
1137
1138config X86_MCE
1139	bool "Machine Check / overheating reporting"
1140	select GENERIC_ALLOCATOR
1141	default y
1142	help
1143	  Machine Check support allows the processor to notify the
1144	  kernel if it detects a problem (e.g. overheating, data corruption).
1145	  The action the kernel takes depends on the severity of the problem,
1146	  ranging from warning messages to halting the machine.
1147
1148config X86_MCELOG_LEGACY
1149	bool "Support for deprecated /dev/mcelog character device"
1150	depends on X86_MCE
1151	help
1152	  Enable support for /dev/mcelog which is needed by the old mcelog
1153	  userspace logging daemon. Consider switching to the new generation
1154	  rasdaemon solution.
1155
1156config X86_MCE_INTEL
1157	def_bool y
1158	prompt "Intel MCE features"
1159	depends on X86_MCE && X86_LOCAL_APIC
1160	help
1161	  Additional support for intel specific MCE features such as
1162	  the thermal monitor.
1163
1164config X86_MCE_AMD
1165	def_bool y
1166	prompt "AMD MCE features"
1167	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1168	help
1169	  Additional support for AMD specific MCE features such as
1170	  the DRAM Error Threshold.
1171
1172config X86_ANCIENT_MCE
1173	bool "Support for old Pentium 5 / WinChip machine checks"
1174	depends on X86_32 && X86_MCE
1175	help
1176	  Include support for machine check handling on old Pentium 5 or WinChip
1177	  systems. These typically need to be enabled explicitly on the command
1178	  line.
1179
1180config X86_MCE_THRESHOLD
1181	depends on X86_MCE_AMD || X86_MCE_INTEL
1182	def_bool y
1183
1184config X86_MCE_INJECT
1185	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1186	tristate "Machine check injector support"
1187	help
1188	  Provide support for injecting machine checks for testing purposes.
1189	  If you don't know what a machine check is and you don't do kernel
1190	  QA it is safe to say n.
1191
1192source "arch/x86/events/Kconfig"
1193
1194config X86_LEGACY_VM86
1195	bool "Legacy VM86 support"
1196	depends on X86_32
1197	help
1198	  This option allows user programs to put the CPU into V8086
1199	  mode, which is an 80286-era approximation of 16-bit real mode.
1200
1201	  Some very old versions of X and/or vbetool require this option
1202	  for user mode setting.  Similarly, DOSEMU will use it if
1203	  available to accelerate real mode DOS programs.  However, any
1204	  recent version of DOSEMU, X, or vbetool should be fully
1205	  functional even without kernel VM86 support, as they will all
1206	  fall back to software emulation. Nevertheless, if you are using
1207	  a 16-bit DOS program where 16-bit performance matters, vm86
1208	  mode might be faster than emulation and you might want to
1209	  enable this option.
1210
1211	  Note that any app that works on a 64-bit kernel is unlikely to
1212	  need this option, as 64-bit kernels don't, and can't, support
1213	  V8086 mode. This option is also unrelated to 16-bit protected
1214	  mode and is not needed to run most 16-bit programs under Wine.
1215
1216	  Enabling this option increases the complexity of the kernel
1217	  and slows down exception handling a tiny bit.
1218
1219	  If unsure, say N here.
1220
1221config VM86
1222	bool
1223	default X86_LEGACY_VM86
1224
1225config X86_16BIT
1226	bool "Enable support for 16-bit segments" if EXPERT
1227	default y
1228	depends on MODIFY_LDT_SYSCALL
1229	help
1230	  This option is required by programs like Wine to run 16-bit
1231	  protected mode legacy code on x86 processors.  Disabling
1232	  this option saves about 300 bytes on i386, or around 6K text
1233	  plus 16K runtime memory on x86-64,
1234
1235config X86_ESPFIX32
1236	def_bool y
1237	depends on X86_16BIT && X86_32
1238
1239config X86_ESPFIX64
1240	def_bool y
1241	depends on X86_16BIT && X86_64
1242
1243config X86_VSYSCALL_EMULATION
1244	bool "Enable vsyscall emulation" if EXPERT
1245	default y
1246	depends on X86_64
1247	help
1248	  This enables emulation of the legacy vsyscall page.  Disabling
1249	  it is roughly equivalent to booting with vsyscall=none, except
1250	  that it will also disable the helpful warning if a program
1251	  tries to use a vsyscall.  With this option set to N, offending
1252	  programs will just segfault, citing addresses of the form
1253	  0xffffffffff600?00.
1254
1255	  This option is required by many programs built before 2013, and
1256	  care should be used even with newer programs if set to N.
1257
1258	  Disabling this option saves about 7K of kernel size and
1259	  possibly 4K of additional runtime pagetable memory.
1260
1261config X86_IOPL_IOPERM
1262	bool "IOPERM and IOPL Emulation"
1263	default y
1264	help
1265	  This enables the ioperm() and iopl() syscalls which are necessary
1266	  for legacy applications.
1267
1268	  Legacy IOPL support is an overbroad mechanism which allows user
1269	  space aside of accessing all 65536 I/O ports also to disable
1270	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1271	  capabilities and permission from potentially active security
1272	  modules.
1273
1274	  The emulation restricts the functionality of the syscall to
1275	  only allowing the full range I/O port access, but prevents the
1276	  ability to disable interrupts from user space which would be
1277	  granted if the hardware IOPL mechanism would be used.
1278
1279config TOSHIBA
1280	tristate "Toshiba Laptop support"
1281	depends on X86_32
1282	help
1283	  This adds a driver to safely access the System Management Mode of
1284	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1285	  not work on models with a Phoenix BIOS. The System Management Mode
1286	  is used to set the BIOS and power saving options on Toshiba portables.
1287
1288	  For information on utilities to make use of this driver see the
1289	  Toshiba Linux utilities web site at:
1290	  <http://www.buzzard.org.uk/toshiba/>.
1291
1292	  Say Y if you intend to run this kernel on a Toshiba portable.
1293	  Say N otherwise.
1294
1295config X86_REBOOTFIXUPS
1296	bool "Enable X86 board specific fixups for reboot"
1297	depends on X86_32
1298	help
1299	  This enables chipset and/or board specific fixups to be done
1300	  in order to get reboot to work correctly. This is only needed on
1301	  some combinations of hardware and BIOS. The symptom, for which
1302	  this config is intended, is when reboot ends with a stalled/hung
1303	  system.
1304
1305	  Currently, the only fixup is for the Geode machines using
1306	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1307
1308	  Say Y if you want to enable the fixup. Currently, it's safe to
1309	  enable this option even if you don't need it.
1310	  Say N otherwise.
1311
1312config MICROCODE
1313	def_bool y
1314	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1315
1316config MICROCODE_INITRD32
1317	def_bool y
1318	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1319
1320config MICROCODE_LATE_LOADING
1321	bool "Late microcode loading (DANGEROUS)"
1322	default n
1323	depends on MICROCODE && SMP
1324	help
1325	  Loading microcode late, when the system is up and executing instructions
1326	  is a tricky business and should be avoided if possible. Just the sequence
1327	  of synchronizing all cores and SMT threads is one fragile dance which does
1328	  not guarantee that cores might not softlock after the loading. Therefore,
1329	  use this at your own risk. Late loading taints the kernel unless the
1330	  microcode header indicates that it is safe for late loading via the
1331	  minimal revision check. This minimal revision check can be enforced on
1332	  the kernel command line with "microcode.minrev=Y".
1333
1334config MICROCODE_LATE_FORCE_MINREV
1335	bool "Enforce late microcode loading minimal revision check"
1336	default n
1337	depends on MICROCODE_LATE_LOADING
1338	help
1339	  To prevent that users load microcode late which modifies already
1340	  in use features, newer microcode patches have a minimum revision field
1341	  in the microcode header, which tells the kernel which minimum
1342	  revision must be active in the CPU to safely load that new microcode
1343	  late into the running system. If disabled the check will not
1344	  be enforced but the kernel will be tainted when the minimal
1345	  revision check fails.
1346
1347	  This minimal revision check can also be controlled via the
1348	  "microcode.minrev" parameter on the kernel command line.
1349
1350	  If unsure say Y.
1351
1352config X86_MSR
1353	tristate "/dev/cpu/*/msr - Model-specific register support"
1354	help
1355	  This device gives privileged processes access to the x86
1356	  Model-Specific Registers (MSRs).  It is a character device with
1357	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358	  MSR accesses are directed to a specific CPU on multi-processor
1359	  systems.
1360
1361config X86_CPUID
1362	tristate "/dev/cpu/*/cpuid - CPU information support"
1363	help
1364	  This device gives processes access to the x86 CPUID instruction to
1365	  be executed on a specific processor.  It is a character device
1366	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367	  /dev/cpu/31/cpuid.
1368
1369choice
1370	prompt "High Memory Support"
1371	default HIGHMEM4G
1372	depends on X86_32
1373
1374config NOHIGHMEM
1375	bool "off"
1376	help
1377	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378	  However, the address space of 32-bit x86 processors is only 4
1379	  Gigabytes large. That means that, if you have a large amount of
1380	  physical memory, not all of it can be "permanently mapped" by the
1381	  kernel. The physical memory that's not permanently mapped is called
1382	  "high memory".
1383
1384	  If you are compiling a kernel which will never run on a machine with
1385	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1386	  choice and suitable for most users). This will result in a "3GB/1GB"
1387	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1388	  space and the remaining part of the 4GB virtual memory space is used
1389	  by the kernel to permanently map as much physical memory as
1390	  possible.
1391
1392	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1393	  answer "4GB" here.
1394
1395	  If more than 4 Gigabytes is used then answer "64GB" here. This
1396	  selection turns Intel PAE (Physical Address Extension) mode on.
1397	  PAE implements 3-level paging on IA32 processors. PAE is fully
1398	  supported by Linux, PAE mode is implemented on all recent Intel
1399	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400	  then the kernel will not boot on CPUs that don't support PAE!
1401
1402	  The actual amount of total physical memory will either be
1403	  auto detected or can be forced by using a kernel command line option
1404	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1405	  your boot loader (lilo or loadlin) about how to pass options to the
1406	  kernel at boot time.)
1407
1408	  If unsure, say "off".
1409
1410config HIGHMEM4G
1411	bool "4GB"
1412	help
1413	  Select this if you have a 32-bit processor and between 1 and 4
1414	  gigabytes of physical RAM.
1415
1416config HIGHMEM64G
1417	bool "64GB"
1418	depends on X86_HAVE_PAE
1419	select X86_PAE
1420	help
1421	  Select this if you have a 32-bit processor and more than 4
1422	  gigabytes of physical RAM.
1423
1424endchoice
1425
1426choice
1427	prompt "Memory split" if EXPERT
1428	default VMSPLIT_3G
1429	depends on X86_32
1430	help
1431	  Select the desired split between kernel and user memory.
1432
1433	  If the address range available to the kernel is less than the
1434	  physical memory installed, the remaining memory will be available
1435	  as "high memory". Accessing high memory is a little more costly
1436	  than low memory, as it needs to be mapped into the kernel first.
1437	  Note that increasing the kernel address space limits the range
1438	  available to user programs, making the address space there
1439	  tighter.  Selecting anything other than the default 3G/1G split
1440	  will also likely make your kernel incompatible with binary-only
1441	  kernel modules.
1442
1443	  If you are not absolutely sure what you are doing, leave this
1444	  option alone!
1445
1446	config VMSPLIT_3G
1447		bool "3G/1G user/kernel split"
1448	config VMSPLIT_3G_OPT
1449		depends on !X86_PAE
1450		bool "3G/1G user/kernel split (for full 1G low memory)"
1451	config VMSPLIT_2G
1452		bool "2G/2G user/kernel split"
1453	config VMSPLIT_2G_OPT
1454		depends on !X86_PAE
1455		bool "2G/2G user/kernel split (for full 2G low memory)"
1456	config VMSPLIT_1G
1457		bool "1G/3G user/kernel split"
1458endchoice
1459
1460config PAGE_OFFSET
1461	hex
1462	default 0xB0000000 if VMSPLIT_3G_OPT
1463	default 0x80000000 if VMSPLIT_2G
1464	default 0x78000000 if VMSPLIT_2G_OPT
1465	default 0x40000000 if VMSPLIT_1G
1466	default 0xC0000000
1467	depends on X86_32
1468
1469config HIGHMEM
1470	def_bool y
1471	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1472
1473config X86_PAE
1474	bool "PAE (Physical Address Extension) Support"
1475	depends on X86_32 && X86_HAVE_PAE
1476	select PHYS_ADDR_T_64BIT
1477	select SWIOTLB
1478	help
1479	  PAE is required for NX support, and furthermore enables
1480	  larger swapspace support for non-overcommit purposes. It
1481	  has the cost of more pagetable lookup overhead, and also
1482	  consumes more pagetable space per process.
1483
1484config X86_5LEVEL
1485	bool "Enable 5-level page tables support"
1486	default y
1487	select DYNAMIC_MEMORY_LAYOUT
1488	select SPARSEMEM_VMEMMAP
1489	depends on X86_64
1490	help
1491	  5-level paging enables access to larger address space:
1492	  up to 128 PiB of virtual address space and 4 PiB of
1493	  physical address space.
1494
1495	  It will be supported by future Intel CPUs.
1496
1497	  A kernel with the option enabled can be booted on machines that
1498	  support 4- or 5-level paging.
1499
1500	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1501	  information.
1502
1503	  Say N if unsure.
1504
1505config X86_DIRECT_GBPAGES
1506	def_bool y
1507	depends on X86_64
1508	help
1509	  Certain kernel features effectively disable kernel
1510	  linear 1 GB mappings (even if the CPU otherwise
1511	  supports them), so don't confuse the user by printing
1512	  that we have them enabled.
1513
1514config X86_CPA_STATISTICS
1515	bool "Enable statistic for Change Page Attribute"
1516	depends on DEBUG_FS
1517	help
1518	  Expose statistics about the Change Page Attribute mechanism, which
1519	  helps to determine the effectiveness of preserving large and huge
1520	  page mappings when mapping protections are changed.
1521
1522config X86_MEM_ENCRYPT
1523	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1524	select DYNAMIC_PHYSICAL_MASK
1525	def_bool n
1526
1527config AMD_MEM_ENCRYPT
1528	bool "AMD Secure Memory Encryption (SME) support"
1529	depends on X86_64 && CPU_SUP_AMD
1530	depends on EFI_STUB
1531	select DMA_COHERENT_POOL
1532	select ARCH_USE_MEMREMAP_PROT
1533	select INSTRUCTION_DECODER
1534	select ARCH_HAS_CC_PLATFORM
1535	select X86_MEM_ENCRYPT
1536	select UNACCEPTED_MEMORY
1537	help
1538	  Say yes to enable support for the encryption of system memory.
1539	  This requires an AMD processor that supports Secure Memory
1540	  Encryption (SME).
1541
1542config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1543	bool "Activate AMD Secure Memory Encryption (SME) by default"
1544	depends on AMD_MEM_ENCRYPT
1545	help
1546	  Say yes to have system memory encrypted by default if running on
1547	  an AMD processor that supports Secure Memory Encryption (SME).
1548
1549	  If set to Y, then the encryption of system memory can be
1550	  deactivated with the mem_encrypt=off command line option.
1551
1552	  If set to N, then the encryption of system memory can be
1553	  activated with the mem_encrypt=on command line option.
1554
1555# Common NUMA Features
1556config NUMA
1557	bool "NUMA Memory Allocation and Scheduler Support"
1558	depends on SMP
1559	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1560	default y if X86_BIGSMP
1561	select USE_PERCPU_NUMA_NODE_ID
1562	select OF_NUMA if OF
1563	help
1564	  Enable NUMA (Non-Uniform Memory Access) support.
1565
1566	  The kernel will try to allocate memory used by a CPU on the
1567	  local memory controller of the CPU and add some more
1568	  NUMA awareness to the kernel.
1569
1570	  For 64-bit this is recommended if the system is Intel Core i7
1571	  (or later), AMD Opteron, or EM64T NUMA.
1572
1573	  For 32-bit this is only needed if you boot a 32-bit
1574	  kernel on a 64-bit NUMA platform.
1575
1576	  Otherwise, you should say N.
1577
1578config AMD_NUMA
1579	def_bool y
1580	prompt "Old style AMD Opteron NUMA detection"
1581	depends on X86_64 && NUMA && PCI
1582	help
1583	  Enable AMD NUMA node topology detection.  You should say Y here if
1584	  you have a multi processor AMD system. This uses an old method to
1585	  read the NUMA configuration directly from the builtin Northbridge
1586	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1587	  which also takes priority if both are compiled in.
1588
1589config X86_64_ACPI_NUMA
1590	def_bool y
1591	prompt "ACPI NUMA detection"
1592	depends on X86_64 && NUMA && ACPI && PCI
1593	select ACPI_NUMA
1594	help
1595	  Enable ACPI SRAT based node topology detection.
1596
1597config NUMA_EMU
1598	bool "NUMA emulation"
1599	depends on NUMA
1600	help
1601	  Enable NUMA emulation. A flat machine will be split
1602	  into virtual nodes when booted with "numa=fake=N", where N is the
1603	  number of nodes. This is only useful for debugging.
1604
1605config NODES_SHIFT
1606	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1607	range 1 10
1608	default "10" if MAXSMP
1609	default "6" if X86_64
1610	default "3"
1611	depends on NUMA
1612	help
1613	  Specify the maximum number of NUMA Nodes available on the target
1614	  system.  Increases memory reserved to accommodate various tables.
1615
1616config ARCH_FLATMEM_ENABLE
1617	def_bool y
1618	depends on X86_32 && !NUMA
1619
1620config ARCH_SPARSEMEM_ENABLE
1621	def_bool y
1622	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1623	select SPARSEMEM_STATIC if X86_32
1624	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1625
1626config ARCH_SPARSEMEM_DEFAULT
1627	def_bool X86_64 || (NUMA && X86_32)
1628
1629config ARCH_SELECT_MEMORY_MODEL
1630	def_bool y
1631	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1632
1633config ARCH_MEMORY_PROBE
1634	bool "Enable sysfs memory/probe interface"
1635	depends on MEMORY_HOTPLUG
1636	help
1637	  This option enables a sysfs memory/probe interface for testing.
1638	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1639	  If you are unsure how to answer this question, answer N.
1640
1641config ARCH_PROC_KCORE_TEXT
1642	def_bool y
1643	depends on X86_64 && PROC_KCORE
1644
1645config ILLEGAL_POINTER_VALUE
1646	hex
1647	default 0 if X86_32
1648	default 0xdead000000000000 if X86_64
1649
1650config X86_PMEM_LEGACY_DEVICE
1651	bool
1652
1653config X86_PMEM_LEGACY
1654	tristate "Support non-standard NVDIMMs and ADR protected memory"
1655	depends on PHYS_ADDR_T_64BIT
1656	depends on BLK_DEV
1657	select X86_PMEM_LEGACY_DEVICE
1658	select NUMA_KEEP_MEMINFO if NUMA
1659	select LIBNVDIMM
1660	help
1661	  Treat memory marked using the non-standard e820 type of 12 as used
1662	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1663	  The kernel will offer these regions to the 'pmem' driver so
1664	  they can be used for persistent storage.
1665
1666	  Say Y if unsure.
1667
1668config HIGHPTE
1669	bool "Allocate 3rd-level pagetables from highmem"
1670	depends on HIGHMEM
1671	help
1672	  The VM uses one page table entry for each page of physical memory.
1673	  For systems with a lot of RAM, this can be wasteful of precious
1674	  low memory.  Setting this option will put user-space page table
1675	  entries in high memory.
1676
1677config X86_CHECK_BIOS_CORRUPTION
1678	bool "Check for low memory corruption"
1679	help
1680	  Periodically check for memory corruption in low memory, which
1681	  is suspected to be caused by BIOS.  Even when enabled in the
1682	  configuration, it is disabled at runtime.  Enable it by
1683	  setting "memory_corruption_check=1" on the kernel command
1684	  line.  By default it scans the low 64k of memory every 60
1685	  seconds; see the memory_corruption_check_size and
1686	  memory_corruption_check_period parameters in
1687	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1688
1689	  When enabled with the default parameters, this option has
1690	  almost no overhead, as it reserves a relatively small amount
1691	  of memory and scans it infrequently.  It both detects corruption
1692	  and prevents it from affecting the running system.
1693
1694	  It is, however, intended as a diagnostic tool; if repeatable
1695	  BIOS-originated corruption always affects the same memory,
1696	  you can use memmap= to prevent the kernel from using that
1697	  memory.
1698
1699config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1700	bool "Set the default setting of memory_corruption_check"
1701	depends on X86_CHECK_BIOS_CORRUPTION
1702	default y
1703	help
1704	  Set whether the default state of memory_corruption_check is
1705	  on or off.
1706
1707config MATH_EMULATION
1708	bool
1709	depends on MODIFY_LDT_SYSCALL
1710	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1711	help
1712	  Linux can emulate a math coprocessor (used for floating point
1713	  operations) if you don't have one. 486DX and Pentium processors have
1714	  a math coprocessor built in, 486SX and 386 do not, unless you added
1715	  a 487DX or 387, respectively. (The messages during boot time can
1716	  give you some hints here ["man dmesg"].) Everyone needs either a
1717	  coprocessor or this emulation.
1718
1719	  If you don't have a math coprocessor, you need to say Y here; if you
1720	  say Y here even though you have a coprocessor, the coprocessor will
1721	  be used nevertheless. (This behavior can be changed with the kernel
1722	  command line option "no387", which comes handy if your coprocessor
1723	  is broken. Try "man bootparam" or see the documentation of your boot
1724	  loader (lilo or loadlin) about how to pass options to the kernel at
1725	  boot time.) This means that it is a good idea to say Y here if you
1726	  intend to use this kernel on different machines.
1727
1728	  More information about the internals of the Linux math coprocessor
1729	  emulation can be found in <file:arch/x86/math-emu/README>.
1730
1731	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1732	  kernel, it won't hurt.
1733
1734config MTRR
1735	def_bool y
1736	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1737	help
1738	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1739	  the Memory Type Range Registers (MTRRs) may be used to control
1740	  processor access to memory ranges. This is most useful if you have
1741	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1742	  allows bus write transfers to be combined into a larger transfer
1743	  before bursting over the PCI/AGP bus. This can increase performance
1744	  of image write operations 2.5 times or more. Saying Y here creates a
1745	  /proc/mtrr file which may be used to manipulate your processor's
1746	  MTRRs. Typically the X server should use this.
1747
1748	  This code has a reasonably generic interface so that similar
1749	  control registers on other processors can be easily supported
1750	  as well:
1751
1752	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1753	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1754	  these, the ARRs are used to emulate the MTRRs.
1755	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1756	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1757	  write-combining. All of these processors are supported by this code
1758	  and it makes sense to say Y here if you have one of them.
1759
1760	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1761	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1762	  can lead to all sorts of problems, so it's good to say Y here.
1763
1764	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1765	  just add about 9 KB to your kernel.
1766
1767	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1768
1769config MTRR_SANITIZER
1770	def_bool y
1771	prompt "MTRR cleanup support"
1772	depends on MTRR
1773	help
1774	  Convert MTRR layout from continuous to discrete, so X drivers can
1775	  add writeback entries.
1776
1777	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1778	  The largest mtrr entry size for a continuous block can be set with
1779	  mtrr_chunk_size.
1780
1781	  If unsure, say Y.
1782
1783config MTRR_SANITIZER_ENABLE_DEFAULT
1784	int "MTRR cleanup enable value (0-1)"
1785	range 0 1
1786	default "0"
1787	depends on MTRR_SANITIZER
1788	help
1789	  Enable mtrr cleanup default value
1790
1791config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1792	int "MTRR cleanup spare reg num (0-7)"
1793	range 0 7
1794	default "1"
1795	depends on MTRR_SANITIZER
1796	help
1797	  mtrr cleanup spare entries default, it can be changed via
1798	  mtrr_spare_reg_nr=N on the kernel command line.
1799
1800config X86_PAT
1801	def_bool y
1802	prompt "x86 PAT support" if EXPERT
1803	depends on MTRR
1804	help
1805	  Use PAT attributes to setup page level cache control.
1806
1807	  PATs are the modern equivalents of MTRRs and are much more
1808	  flexible than MTRRs.
1809
1810	  Say N here if you see bootup problems (boot crash, boot hang,
1811	  spontaneous reboots) or a non-working video driver.
1812
1813	  If unsure, say Y.
1814
1815config ARCH_USES_PG_UNCACHED
1816	def_bool y
1817	depends on X86_PAT
1818
1819config X86_UMIP
1820	def_bool y
1821	prompt "User Mode Instruction Prevention" if EXPERT
1822	help
1823	  User Mode Instruction Prevention (UMIP) is a security feature in
1824	  some x86 processors. If enabled, a general protection fault is
1825	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1826	  executed in user mode. These instructions unnecessarily expose
1827	  information about the hardware state.
1828
1829	  The vast majority of applications do not use these instructions.
1830	  For the very few that do, software emulation is provided in
1831	  specific cases in protected and virtual-8086 modes. Emulated
1832	  results are dummy.
1833
1834config CC_HAS_IBT
1835	# GCC >= 9 and binutils >= 2.29
1836	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1837	# Clang/LLVM >= 14
1838	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1839	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1840	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1841		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1842		  $(as-instr,endbr64)
1843
1844config X86_CET
1845	def_bool n
1846	help
1847	  CET features configured (Shadow stack or IBT)
1848
1849config X86_KERNEL_IBT
1850	prompt "Indirect Branch Tracking"
1851	def_bool y
1852	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1853	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1854	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1855	select OBJTOOL
1856	select X86_CET
1857	help
1858	  Build the kernel with support for Indirect Branch Tracking, a
1859	  hardware support course-grain forward-edge Control Flow Integrity
1860	  protection. It enforces that all indirect calls must land on
1861	  an ENDBR instruction, as such, the compiler will instrument the
1862	  code with them to make this happen.
1863
1864	  In addition to building the kernel with IBT, seal all functions that
1865	  are not indirect call targets, avoiding them ever becoming one.
1866
1867	  This requires LTO like objtool runs and will slow down the build. It
1868	  does significantly reduce the number of ENDBR instructions in the
1869	  kernel image.
1870
1871config X86_INTEL_MEMORY_PROTECTION_KEYS
1872	prompt "Memory Protection Keys"
1873	def_bool y
1874	# Note: only available in 64-bit mode
1875	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1876	select ARCH_USES_HIGH_VMA_FLAGS
1877	select ARCH_HAS_PKEYS
1878	help
1879	  Memory Protection Keys provides a mechanism for enforcing
1880	  page-based protections, but without requiring modification of the
1881	  page tables when an application changes protection domains.
1882
1883	  For details, see Documentation/core-api/protection-keys.rst
1884
1885	  If unsure, say y.
1886
1887choice
1888	prompt "TSX enable mode"
1889	depends on CPU_SUP_INTEL
1890	default X86_INTEL_TSX_MODE_OFF
1891	help
1892	  Intel's TSX (Transactional Synchronization Extensions) feature
1893	  allows to optimize locking protocols through lock elision which
1894	  can lead to a noticeable performance boost.
1895
1896	  On the other hand it has been shown that TSX can be exploited
1897	  to form side channel attacks (e.g. TAA) and chances are there
1898	  will be more of those attacks discovered in the future.
1899
1900	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1901	  might override this decision by tsx=on the command line parameter.
1902	  Even with TSX enabled, the kernel will attempt to enable the best
1903	  possible TAA mitigation setting depending on the microcode available
1904	  for the particular machine.
1905
1906	  This option allows to set the default tsx mode between tsx=on, =off
1907	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1908	  details.
1909
1910	  Say off if not sure, auto if TSX is in use but it should be used on safe
1911	  platforms or on if TSX is in use and the security aspect of tsx is not
1912	  relevant.
1913
1914config X86_INTEL_TSX_MODE_OFF
1915	bool "off"
1916	help
1917	  TSX is disabled if possible - equals to tsx=off command line parameter.
1918
1919config X86_INTEL_TSX_MODE_ON
1920	bool "on"
1921	help
1922	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1923	  line parameter.
1924
1925config X86_INTEL_TSX_MODE_AUTO
1926	bool "auto"
1927	help
1928	  TSX is enabled on TSX capable HW that is believed to be safe against
1929	  side channel attacks- equals the tsx=auto command line parameter.
1930endchoice
1931
1932config X86_SGX
1933	bool "Software Guard eXtensions (SGX)"
1934	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1935	depends on CRYPTO=y
1936	depends on CRYPTO_SHA256=y
1937	select MMU_NOTIFIER
1938	select NUMA_KEEP_MEMINFO if NUMA
1939	select XARRAY_MULTI
1940	help
1941	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1942	  that can be used by applications to set aside private regions of code
1943	  and data, referred to as enclaves. An enclave's private memory can
1944	  only be accessed by code running within the enclave. Accesses from
1945	  outside the enclave, including other enclaves, are disallowed by
1946	  hardware.
1947
1948	  If unsure, say N.
1949
1950config X86_USER_SHADOW_STACK
1951	bool "X86 userspace shadow stack"
1952	depends on AS_WRUSS
1953	depends on X86_64
1954	select ARCH_USES_HIGH_VMA_FLAGS
1955	select X86_CET
1956	help
1957	  Shadow stack protection is a hardware feature that detects function
1958	  return address corruption.  This helps mitigate ROP attacks.
1959	  Applications must be enabled to use it, and old userspace does not
1960	  get protection "for free".
1961
1962	  CPUs supporting shadow stacks were first released in 2020.
1963
1964	  See Documentation/arch/x86/shstk.rst for more information.
1965
1966	  If unsure, say N.
1967
1968config INTEL_TDX_HOST
1969	bool "Intel Trust Domain Extensions (TDX) host support"
1970	depends on CPU_SUP_INTEL
1971	depends on X86_64
1972	depends on KVM_INTEL
1973	depends on X86_X2APIC
1974	select ARCH_KEEP_MEMBLOCK
1975	depends on CONTIG_ALLOC
1976	depends on !KEXEC_CORE
1977	depends on X86_MCE
1978	help
1979	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1980	  host and certain physical attacks.  This option enables necessary TDX
1981	  support in the host kernel to run confidential VMs.
1982
1983	  If unsure, say N.
1984
1985config EFI
1986	bool "EFI runtime service support"
1987	depends on ACPI
1988	select UCS2_STRING
1989	select EFI_RUNTIME_WRAPPERS
1990	select ARCH_USE_MEMREMAP_PROT
1991	select EFI_RUNTIME_MAP if KEXEC_CORE
1992	help
1993	  This enables the kernel to use EFI runtime services that are
1994	  available (such as the EFI variable services).
1995
1996	  This option is only useful on systems that have EFI firmware.
1997	  In addition, you should use the latest ELILO loader available
1998	  at <http://elilo.sourceforge.net> in order to take advantage
1999	  of EFI runtime services. However, even with this option, the
2000	  resultant kernel should continue to boot on existing non-EFI
2001	  platforms.
2002
2003config EFI_STUB
2004	bool "EFI stub support"
2005	depends on EFI
2006	select RELOCATABLE
2007	help
2008	  This kernel feature allows a bzImage to be loaded directly
2009	  by EFI firmware without the use of a bootloader.
2010
2011	  See Documentation/admin-guide/efi-stub.rst for more information.
2012
2013config EFI_HANDOVER_PROTOCOL
2014	bool "EFI handover protocol (DEPRECATED)"
2015	depends on EFI_STUB
2016	default y
2017	help
2018	  Select this in order to include support for the deprecated EFI
2019	  handover protocol, which defines alternative entry points into the
2020	  EFI stub.  This is a practice that has no basis in the UEFI
2021	  specification, and requires a priori knowledge on the part of the
2022	  bootloader about Linux/x86 specific ways of passing the command line
2023	  and initrd, and where in memory those assets may be loaded.
2024
2025	  If in doubt, say Y. Even though the corresponding support is not
2026	  present in upstream GRUB or other bootloaders, most distros build
2027	  GRUB with numerous downstream patches applied, and may rely on the
2028	  handover protocol as as result.
2029
2030config EFI_MIXED
2031	bool "EFI mixed-mode support"
2032	depends on EFI_STUB && X86_64
2033	help
2034	  Enabling this feature allows a 64-bit kernel to be booted
2035	  on a 32-bit firmware, provided that your CPU supports 64-bit
2036	  mode.
2037
2038	  Note that it is not possible to boot a mixed-mode enabled
2039	  kernel via the EFI boot stub - a bootloader that supports
2040	  the EFI handover protocol must be used.
2041
2042	  If unsure, say N.
2043
2044config EFI_FAKE_MEMMAP
2045	bool "Enable EFI fake memory map"
2046	depends on EFI
2047	help
2048	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2049	  this parameter, you can add arbitrary attribute to specific memory
2050	  range by updating original (firmware provided) EFI memmap.  This is
2051	  useful for debugging of EFI memmap related feature, e.g., Address
2052	  Range Mirroring feature.
2053
2054config EFI_MAX_FAKE_MEM
2055	int "maximum allowable number of ranges in efi_fake_mem boot option"
2056	depends on EFI_FAKE_MEMMAP
2057	range 1 128
2058	default 8
2059	help
2060	  Maximum allowable number of ranges in efi_fake_mem boot option.
2061	  Ranges can be set up to this value using comma-separated list.
2062	  The default value is 8.
2063
2064config EFI_RUNTIME_MAP
2065	bool "Export EFI runtime maps to sysfs" if EXPERT
2066	depends on EFI
2067	help
2068	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2069	  That memory map is required by the 2nd kernel to set up EFI virtual
2070	  mappings after kexec, but can also be used for debugging purposes.
2071
2072	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2073
2074source "kernel/Kconfig.hz"
2075
2076config ARCH_SUPPORTS_KEXEC
2077	def_bool y
2078
2079config ARCH_SUPPORTS_KEXEC_FILE
2080	def_bool X86_64
2081
2082config ARCH_SELECTS_KEXEC_FILE
2083	def_bool y
2084	depends on KEXEC_FILE
2085	select HAVE_IMA_KEXEC if IMA
2086
2087config ARCH_SUPPORTS_KEXEC_PURGATORY
2088	def_bool y
2089
2090config ARCH_SUPPORTS_KEXEC_SIG
2091	def_bool y
2092
2093config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2094	def_bool y
2095
2096config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2097	def_bool y
2098
2099config ARCH_SUPPORTS_KEXEC_JUMP
2100	def_bool y
2101
2102config ARCH_SUPPORTS_CRASH_DUMP
2103	def_bool X86_64 || (X86_32 && HIGHMEM)
2104
2105config ARCH_SUPPORTS_CRASH_HOTPLUG
2106	def_bool y
2107
2108config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2109	def_bool CRASH_CORE
2110
2111config PHYSICAL_START
2112	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2113	default "0x1000000"
2114	help
2115	  This gives the physical address where the kernel is loaded.
2116
2117	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2118	  bzImage will decompress itself to above physical address and
2119	  run from there. Otherwise, bzImage will run from the address where
2120	  it has been loaded by the boot loader and will ignore above physical
2121	  address.
2122
2123	  In normal kdump cases one does not have to set/change this option
2124	  as now bzImage can be compiled as a completely relocatable image
2125	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2126	  address. This option is mainly useful for the folks who don't want
2127	  to use a bzImage for capturing the crash dump and want to use a
2128	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2129	  to be specifically compiled to run from a specific memory area
2130	  (normally a reserved region) and this option comes handy.
2131
2132	  So if you are using bzImage for capturing the crash dump,
2133	  leave the value here unchanged to 0x1000000 and set
2134	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2135	  for capturing the crash dump change this value to start of
2136	  the reserved region.  In other words, it can be set based on
2137	  the "X" value as specified in the "crashkernel=YM@XM"
2138	  command line boot parameter passed to the panic-ed
2139	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2140	  for more details about crash dumps.
2141
2142	  Usage of bzImage for capturing the crash dump is recommended as
2143	  one does not have to build two kernels. Same kernel can be used
2144	  as production kernel and capture kernel. Above option should have
2145	  gone away after relocatable bzImage support is introduced. But it
2146	  is present because there are users out there who continue to use
2147	  vmlinux for dump capture. This option should go away down the
2148	  line.
2149
2150	  Don't change this unless you know what you are doing.
2151
2152config RELOCATABLE
2153	bool "Build a relocatable kernel"
2154	default y
2155	help
2156	  This builds a kernel image that retains relocation information
2157	  so it can be loaded someplace besides the default 1MB.
2158	  The relocations tend to make the kernel binary about 10% larger,
2159	  but are discarded at runtime.
2160
2161	  One use is for the kexec on panic case where the recovery kernel
2162	  must live at a different physical address than the primary
2163	  kernel.
2164
2165	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2166	  it has been loaded at and the compile time physical address
2167	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2168
2169config RANDOMIZE_BASE
2170	bool "Randomize the address of the kernel image (KASLR)"
2171	depends on RELOCATABLE
2172	default y
2173	help
2174	  In support of Kernel Address Space Layout Randomization (KASLR),
2175	  this randomizes the physical address at which the kernel image
2176	  is decompressed and the virtual address where the kernel
2177	  image is mapped, as a security feature that deters exploit
2178	  attempts relying on knowledge of the location of kernel
2179	  code internals.
2180
2181	  On 64-bit, the kernel physical and virtual addresses are
2182	  randomized separately. The physical address will be anywhere
2183	  between 16MB and the top of physical memory (up to 64TB). The
2184	  virtual address will be randomized from 16MB up to 1GB (9 bits
2185	  of entropy). Note that this also reduces the memory space
2186	  available to kernel modules from 1.5GB to 1GB.
2187
2188	  On 32-bit, the kernel physical and virtual addresses are
2189	  randomized together. They will be randomized from 16MB up to
2190	  512MB (8 bits of entropy).
2191
2192	  Entropy is generated using the RDRAND instruction if it is
2193	  supported. If RDTSC is supported, its value is mixed into
2194	  the entropy pool as well. If neither RDRAND nor RDTSC are
2195	  supported, then entropy is read from the i8254 timer. The
2196	  usable entropy is limited by the kernel being built using
2197	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2198	  minimum of 2MB. As a result, only 10 bits of entropy are
2199	  theoretically possible, but the implementations are further
2200	  limited due to memory layouts.
2201
2202	  If unsure, say Y.
2203
2204# Relocation on x86 needs some additional build support
2205config X86_NEED_RELOCS
2206	def_bool y
2207	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2208
2209config PHYSICAL_ALIGN
2210	hex "Alignment value to which kernel should be aligned"
2211	default "0x200000"
2212	range 0x2000 0x1000000 if X86_32
2213	range 0x200000 0x1000000 if X86_64
2214	help
2215	  This value puts the alignment restrictions on physical address
2216	  where kernel is loaded and run from. Kernel is compiled for an
2217	  address which meets above alignment restriction.
2218
2219	  If bootloader loads the kernel at a non-aligned address and
2220	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2221	  address aligned to above value and run from there.
2222
2223	  If bootloader loads the kernel at a non-aligned address and
2224	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2225	  load address and decompress itself to the address it has been
2226	  compiled for and run from there. The address for which kernel is
2227	  compiled already meets above alignment restrictions. Hence the
2228	  end result is that kernel runs from a physical address meeting
2229	  above alignment restrictions.
2230
2231	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2232	  this value must be a multiple of 0x200000.
2233
2234	  Don't change this unless you know what you are doing.
2235
2236config DYNAMIC_MEMORY_LAYOUT
2237	bool
2238	help
2239	  This option makes base addresses of vmalloc and vmemmap as well as
2240	  __PAGE_OFFSET movable during boot.
2241
2242config RANDOMIZE_MEMORY
2243	bool "Randomize the kernel memory sections"
2244	depends on X86_64
2245	depends on RANDOMIZE_BASE
2246	select DYNAMIC_MEMORY_LAYOUT
2247	default RANDOMIZE_BASE
2248	help
2249	  Randomizes the base virtual address of kernel memory sections
2250	  (physical memory mapping, vmalloc & vmemmap). This security feature
2251	  makes exploits relying on predictable memory locations less reliable.
2252
2253	  The order of allocations remains unchanged. Entropy is generated in
2254	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2255	  configuration have in average 30,000 different possible virtual
2256	  addresses for each memory section.
2257
2258	  If unsure, say Y.
2259
2260config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2261	hex "Physical memory mapping padding" if EXPERT
2262	depends on RANDOMIZE_MEMORY
2263	default "0xa" if MEMORY_HOTPLUG
2264	default "0x0"
2265	range 0x1 0x40 if MEMORY_HOTPLUG
2266	range 0x0 0x40
2267	help
2268	  Define the padding in terabytes added to the existing physical
2269	  memory size during kernel memory randomization. It is useful
2270	  for memory hotplug support but reduces the entropy available for
2271	  address randomization.
2272
2273	  If unsure, leave at the default value.
2274
2275config ADDRESS_MASKING
2276	bool "Linear Address Masking support"
2277	depends on X86_64
2278	help
2279	  Linear Address Masking (LAM) modifies the checking that is applied
2280	  to 64-bit linear addresses, allowing software to use of the
2281	  untranslated address bits for metadata.
2282
2283	  The capability can be used for efficient address sanitizers (ASAN)
2284	  implementation and for optimizations in JITs.
2285
2286config HOTPLUG_CPU
2287	def_bool y
2288	depends on SMP
2289
2290config COMPAT_VDSO
2291	def_bool n
2292	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2293	depends on COMPAT_32
2294	help
2295	  Certain buggy versions of glibc will crash if they are
2296	  presented with a 32-bit vDSO that is not mapped at the address
2297	  indicated in its segment table.
2298
2299	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2300	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2301	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2302	  the only released version with the bug, but OpenSUSE 9
2303	  contains a buggy "glibc 2.3.2".
2304
2305	  The symptom of the bug is that everything crashes on startup, saying:
2306	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2307
2308	  Saying Y here changes the default value of the vdso32 boot
2309	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2310	  This works around the glibc bug but hurts performance.
2311
2312	  If unsure, say N: if you are compiling your own kernel, you
2313	  are unlikely to be using a buggy version of glibc.
2314
2315choice
2316	prompt "vsyscall table for legacy applications"
2317	depends on X86_64
2318	default LEGACY_VSYSCALL_XONLY
2319	help
2320	  Legacy user code that does not know how to find the vDSO expects
2321	  to be able to issue three syscalls by calling fixed addresses in
2322	  kernel space. Since this location is not randomized with ASLR,
2323	  it can be used to assist security vulnerability exploitation.
2324
2325	  This setting can be changed at boot time via the kernel command
2326	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2327	  is deprecated and can only be enabled using the kernel command
2328	  line.
2329
2330	  On a system with recent enough glibc (2.14 or newer) and no
2331	  static binaries, you can say None without a performance penalty
2332	  to improve security.
2333
2334	  If unsure, select "Emulate execution only".
2335
2336	config LEGACY_VSYSCALL_XONLY
2337		bool "Emulate execution only"
2338		help
2339		  The kernel traps and emulates calls into the fixed vsyscall
2340		  address mapping and does not allow reads.  This
2341		  configuration is recommended when userspace might use the
2342		  legacy vsyscall area but support for legacy binary
2343		  instrumentation of legacy code is not needed.  It mitigates
2344		  certain uses of the vsyscall area as an ASLR-bypassing
2345		  buffer.
2346
2347	config LEGACY_VSYSCALL_NONE
2348		bool "None"
2349		help
2350		  There will be no vsyscall mapping at all. This will
2351		  eliminate any risk of ASLR bypass due to the vsyscall
2352		  fixed address mapping. Attempts to use the vsyscalls
2353		  will be reported to dmesg, so that either old or
2354		  malicious userspace programs can be identified.
2355
2356endchoice
2357
2358config CMDLINE_BOOL
2359	bool "Built-in kernel command line"
2360	help
2361	  Allow for specifying boot arguments to the kernel at
2362	  build time.  On some systems (e.g. embedded ones), it is
2363	  necessary or convenient to provide some or all of the
2364	  kernel boot arguments with the kernel itself (that is,
2365	  to not rely on the boot loader to provide them.)
2366
2367	  To compile command line arguments into the kernel,
2368	  set this option to 'Y', then fill in the
2369	  boot arguments in CONFIG_CMDLINE.
2370
2371	  Systems with fully functional boot loaders (i.e. non-embedded)
2372	  should leave this option set to 'N'.
2373
2374config CMDLINE
2375	string "Built-in kernel command string"
2376	depends on CMDLINE_BOOL
2377	default ""
2378	help
2379	  Enter arguments here that should be compiled into the kernel
2380	  image and used at boot time.  If the boot loader provides a
2381	  command line at boot time, it is appended to this string to
2382	  form the full kernel command line, when the system boots.
2383
2384	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2385	  change this behavior.
2386
2387	  In most cases, the command line (whether built-in or provided
2388	  by the boot loader) should specify the device for the root
2389	  file system.
2390
2391config CMDLINE_OVERRIDE
2392	bool "Built-in command line overrides boot loader arguments"
2393	depends on CMDLINE_BOOL && CMDLINE != ""
2394	help
2395	  Set this option to 'Y' to have the kernel ignore the boot loader
2396	  command line, and use ONLY the built-in command line.
2397
2398	  This is used to work around broken boot loaders.  This should
2399	  be set to 'N' under normal conditions.
2400
2401config MODIFY_LDT_SYSCALL
2402	bool "Enable the LDT (local descriptor table)" if EXPERT
2403	default y
2404	help
2405	  Linux can allow user programs to install a per-process x86
2406	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2407	  call.  This is required to run 16-bit or segmented code such as
2408	  DOSEMU or some Wine programs.  It is also used by some very old
2409	  threading libraries.
2410
2411	  Enabling this feature adds a small amount of overhead to
2412	  context switches and increases the low-level kernel attack
2413	  surface.  Disabling it removes the modify_ldt(2) system call.
2414
2415	  Saying 'N' here may make sense for embedded or server kernels.
2416
2417config STRICT_SIGALTSTACK_SIZE
2418	bool "Enforce strict size checking for sigaltstack"
2419	depends on DYNAMIC_SIGFRAME
2420	help
2421	  For historical reasons MINSIGSTKSZ is a constant which became
2422	  already too small with AVX512 support. Add a mechanism to
2423	  enforce strict checking of the sigaltstack size against the
2424	  real size of the FPU frame. This option enables the check
2425	  by default. It can also be controlled via the kernel command
2426	  line option 'strict_sas_size' independent of this config
2427	  switch. Enabling it might break existing applications which
2428	  allocate a too small sigaltstack but 'work' because they
2429	  never get a signal delivered.
2430
2431	  Say 'N' unless you want to really enforce this check.
2432
2433source "kernel/livepatch/Kconfig"
2434
2435endmenu
2436
2437config CC_HAS_SLS
2438	def_bool $(cc-option,-mharden-sls=all)
2439
2440config CC_HAS_RETURN_THUNK
2441	def_bool $(cc-option,-mfunction-return=thunk-extern)
2442
2443config CC_HAS_ENTRY_PADDING
2444	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2445
2446config FUNCTION_PADDING_CFI
2447	int
2448	default 59 if FUNCTION_ALIGNMENT_64B
2449	default 27 if FUNCTION_ALIGNMENT_32B
2450	default 11 if FUNCTION_ALIGNMENT_16B
2451	default  3 if FUNCTION_ALIGNMENT_8B
2452	default  0
2453
2454# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2455# except Kconfig can't do arithmetic :/
2456config FUNCTION_PADDING_BYTES
2457	int
2458	default FUNCTION_PADDING_CFI if CFI_CLANG
2459	default FUNCTION_ALIGNMENT
2460
2461config CALL_PADDING
2462	def_bool n
2463	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2464	select FUNCTION_ALIGNMENT_16B
2465
2466config FINEIBT
2467	def_bool y
2468	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2469	select CALL_PADDING
2470
2471config HAVE_CALL_THUNKS
2472	def_bool y
2473	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2474
2475config CALL_THUNKS
2476	def_bool n
2477	select CALL_PADDING
2478
2479config PREFIX_SYMBOLS
2480	def_bool y
2481	depends on CALL_PADDING && !CFI_CLANG
2482
2483menuconfig SPECULATION_MITIGATIONS
2484	bool "Mitigations for speculative execution vulnerabilities"
2485	default y
2486	help
2487	  Say Y here to enable options which enable mitigations for
2488	  speculative execution hardware vulnerabilities.
2489
2490	  If you say N, all mitigations will be disabled. You really
2491	  should know what you are doing to say so.
2492
2493if SPECULATION_MITIGATIONS
2494
2495config PAGE_TABLE_ISOLATION
2496	bool "Remove the kernel mapping in user mode"
2497	default y
2498	depends on (X86_64 || X86_PAE)
2499	help
2500	  This feature reduces the number of hardware side channels by
2501	  ensuring that the majority of kernel addresses are not mapped
2502	  into userspace.
2503
2504	  See Documentation/arch/x86/pti.rst for more details.
2505
2506config RETPOLINE
2507	bool "Avoid speculative indirect branches in kernel"
2508	select OBJTOOL if HAVE_OBJTOOL
2509	default y
2510	help
2511	  Compile kernel with the retpoline compiler options to guard against
2512	  kernel-to-user data leaks by avoiding speculative indirect
2513	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2514	  support for full protection. The kernel may run slower.
2515
2516config RETHUNK
2517	bool "Enable return-thunks"
2518	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2519	select OBJTOOL if HAVE_OBJTOOL
2520	default y if X86_64
2521	help
2522	  Compile the kernel with the return-thunks compiler option to guard
2523	  against kernel-to-user data leaks by avoiding return speculation.
2524	  Requires a compiler with -mfunction-return=thunk-extern
2525	  support for full protection. The kernel may run slower.
2526
2527config CPU_UNRET_ENTRY
2528	bool "Enable UNRET on kernel entry"
2529	depends on CPU_SUP_AMD && RETHUNK && X86_64
2530	default y
2531	help
2532	  Compile the kernel with support for the retbleed=unret mitigation.
2533
2534config CALL_DEPTH_TRACKING
2535	bool "Mitigate RSB underflow with call depth tracking"
2536	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2537	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2538	select CALL_THUNKS
2539	default y
2540	help
2541	  Compile the kernel with call depth tracking to mitigate the Intel
2542	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2543	  mitigation is off by default and needs to be enabled on the
2544	  kernel command line via the retbleed=stuff option. For
2545	  non-affected systems the overhead of this option is marginal as
2546	  the call depth tracking is using run-time generated call thunks
2547	  in a compiler generated padding area and call patching. This
2548	  increases text size by ~5%. For non affected systems this space
2549	  is unused. On affected SKL systems this results in a significant
2550	  performance gain over the IBRS mitigation.
2551
2552config CALL_THUNKS_DEBUG
2553	bool "Enable call thunks and call depth tracking debugging"
2554	depends on CALL_DEPTH_TRACKING
2555	select FUNCTION_ALIGNMENT_32B
2556	default n
2557	help
2558	  Enable call/ret counters for imbalance detection and build in
2559	  a noisy dmesg about callthunks generation and call patching for
2560	  trouble shooting. The debug prints need to be enabled on the
2561	  kernel command line with 'debug-callthunks'.
2562	  Only enable this when you are debugging call thunks as this
2563	  creates a noticeable runtime overhead. If unsure say N.
2564
2565config CPU_IBPB_ENTRY
2566	bool "Enable IBPB on kernel entry"
2567	depends on CPU_SUP_AMD && X86_64
2568	default y
2569	help
2570	  Compile the kernel with support for the retbleed=ibpb mitigation.
2571
2572config CPU_IBRS_ENTRY
2573	bool "Enable IBRS on kernel entry"
2574	depends on CPU_SUP_INTEL && X86_64
2575	default y
2576	help
2577	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2578	  This mitigates both spectre_v2 and retbleed at great cost to
2579	  performance.
2580
2581config CPU_SRSO
2582	bool "Mitigate speculative RAS overflow on AMD"
2583	depends on CPU_SUP_AMD && X86_64 && RETHUNK
2584	default y
2585	help
2586	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2587
2588config SLS
2589	bool "Mitigate Straight-Line-Speculation"
2590	depends on CC_HAS_SLS && X86_64
2591	select OBJTOOL if HAVE_OBJTOOL
2592	default n
2593	help
2594	  Compile the kernel with straight-line-speculation options to guard
2595	  against straight line speculation. The kernel image might be slightly
2596	  larger.
2597
2598config GDS_FORCE_MITIGATION
2599	bool "Force GDS Mitigation"
2600	depends on CPU_SUP_INTEL
2601	default n
2602	help
2603	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2604	  unprivileged speculative access to data which was previously stored in
2605	  vector registers.
2606
2607	  This option is equivalent to setting gather_data_sampling=force on the
2608	  command line. The microcode mitigation is used if present, otherwise
2609	  AVX is disabled as a mitigation. On affected systems that are missing
2610	  the microcode any userspace code that unconditionally uses AVX will
2611	  break with this option set.
2612
2613	  Setting this option on systems not vulnerable to GDS has no effect.
2614
2615	  If in doubt, say N.
2616
2617endif
2618
2619config ARCH_HAS_ADD_PAGES
2620	def_bool y
2621	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2622
2623menu "Power management and ACPI options"
2624
2625config ARCH_HIBERNATION_HEADER
2626	def_bool y
2627	depends on HIBERNATION
2628
2629source "kernel/power/Kconfig"
2630
2631source "drivers/acpi/Kconfig"
2632
2633config X86_APM_BOOT
2634	def_bool y
2635	depends on APM
2636
2637menuconfig APM
2638	tristate "APM (Advanced Power Management) BIOS support"
2639	depends on X86_32 && PM_SLEEP
2640	help
2641	  APM is a BIOS specification for saving power using several different
2642	  techniques. This is mostly useful for battery powered laptops with
2643	  APM compliant BIOSes. If you say Y here, the system time will be
2644	  reset after a RESUME operation, the /proc/apm device will provide
2645	  battery status information, and user-space programs will receive
2646	  notification of APM "events" (e.g. battery status change).
2647
2648	  If you select "Y" here, you can disable actual use of the APM
2649	  BIOS by passing the "apm=off" option to the kernel at boot time.
2650
2651	  Note that the APM support is almost completely disabled for
2652	  machines with more than one CPU.
2653
2654	  In order to use APM, you will need supporting software. For location
2655	  and more information, read <file:Documentation/power/apm-acpi.rst>
2656	  and the Battery Powered Linux mini-HOWTO, available from
2657	  <http://www.tldp.org/docs.html#howto>.
2658
2659	  This driver does not spin down disk drives (see the hdparm(8)
2660	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2661	  VESA-compliant "green" monitors.
2662
2663	  This driver does not support the TI 4000M TravelMate and the ACER
2664	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2665	  desktop machines also don't have compliant BIOSes, and this driver
2666	  may cause those machines to panic during the boot phase.
2667
2668	  Generally, if you don't have a battery in your machine, there isn't
2669	  much point in using this driver and you should say N. If you get
2670	  random kernel OOPSes or reboots that don't seem to be related to
2671	  anything, try disabling/enabling this option (or disabling/enabling
2672	  APM in your BIOS).
2673
2674	  Some other things you should try when experiencing seemingly random,
2675	  "weird" problems:
2676
2677	  1) make sure that you have enough swap space and that it is
2678	  enabled.
2679	  2) pass the "idle=poll" option to the kernel
2680	  3) switch on floating point emulation in the kernel and pass
2681	  the "no387" option to the kernel
2682	  4) pass the "floppy=nodma" option to the kernel
2683	  5) pass the "mem=4M" option to the kernel (thereby disabling
2684	  all but the first 4 MB of RAM)
2685	  6) make sure that the CPU is not over clocked.
2686	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2687	  8) disable the cache from your BIOS settings
2688	  9) install a fan for the video card or exchange video RAM
2689	  10) install a better fan for the CPU
2690	  11) exchange RAM chips
2691	  12) exchange the motherboard.
2692
2693	  To compile this driver as a module, choose M here: the
2694	  module will be called apm.
2695
2696if APM
2697
2698config APM_IGNORE_USER_SUSPEND
2699	bool "Ignore USER SUSPEND"
2700	help
2701	  This option will ignore USER SUSPEND requests. On machines with a
2702	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2703	  series notebooks, it is necessary to say Y because of a BIOS bug.
2704
2705config APM_DO_ENABLE
2706	bool "Enable PM at boot time"
2707	help
2708	  Enable APM features at boot time. From page 36 of the APM BIOS
2709	  specification: "When disabled, the APM BIOS does not automatically
2710	  power manage devices, enter the Standby State, enter the Suspend
2711	  State, or take power saving steps in response to CPU Idle calls."
2712	  This driver will make CPU Idle calls when Linux is idle (unless this
2713	  feature is turned off -- see "Do CPU IDLE calls", below). This
2714	  should always save battery power, but more complicated APM features
2715	  will be dependent on your BIOS implementation. You may need to turn
2716	  this option off if your computer hangs at boot time when using APM
2717	  support, or if it beeps continuously instead of suspending. Turn
2718	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2719	  T400CDT. This is off by default since most machines do fine without
2720	  this feature.
2721
2722config APM_CPU_IDLE
2723	depends on CPU_IDLE
2724	bool "Make CPU Idle calls when idle"
2725	help
2726	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2727	  On some machines, this can activate improved power savings, such as
2728	  a slowed CPU clock rate, when the machine is idle. These idle calls
2729	  are made after the idle loop has run for some length of time (e.g.,
2730	  333 mS). On some machines, this will cause a hang at boot time or
2731	  whenever the CPU becomes idle. (On machines with more than one CPU,
2732	  this option does nothing.)
2733
2734config APM_DISPLAY_BLANK
2735	bool "Enable console blanking using APM"
2736	help
2737	  Enable console blanking using the APM. Some laptops can use this to
2738	  turn off the LCD backlight when the screen blanker of the Linux
2739	  virtual console blanks the screen. Note that this is only used by
2740	  the virtual console screen blanker, and won't turn off the backlight
2741	  when using the X Window system. This also doesn't have anything to
2742	  do with your VESA-compliant power-saving monitor. Further, this
2743	  option doesn't work for all laptops -- it might not turn off your
2744	  backlight at all, or it might print a lot of errors to the console,
2745	  especially if you are using gpm.
2746
2747config APM_ALLOW_INTS
2748	bool "Allow interrupts during APM BIOS calls"
2749	help
2750	  Normally we disable external interrupts while we are making calls to
2751	  the APM BIOS as a measure to lessen the effects of a badly behaving
2752	  BIOS implementation.  The BIOS should reenable interrupts if it
2753	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2754	  many of the newer IBM Thinkpads.  If you experience hangs when you
2755	  suspend, try setting this to Y.  Otherwise, say N.
2756
2757endif # APM
2758
2759source "drivers/cpufreq/Kconfig"
2760
2761source "drivers/cpuidle/Kconfig"
2762
2763source "drivers/idle/Kconfig"
2764
2765endmenu
2766
2767menu "Bus options (PCI etc.)"
2768
2769choice
2770	prompt "PCI access mode"
2771	depends on X86_32 && PCI
2772	default PCI_GOANY
2773	help
2774	  On PCI systems, the BIOS can be used to detect the PCI devices and
2775	  determine their configuration. However, some old PCI motherboards
2776	  have BIOS bugs and may crash if this is done. Also, some embedded
2777	  PCI-based systems don't have any BIOS at all. Linux can also try to
2778	  detect the PCI hardware directly without using the BIOS.
2779
2780	  With this option, you can specify how Linux should detect the
2781	  PCI devices. If you choose "BIOS", the BIOS will be used,
2782	  if you choose "Direct", the BIOS won't be used, and if you
2783	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2784	  If you choose "Any", the kernel will try MMCONFIG, then the
2785	  direct access method and falls back to the BIOS if that doesn't
2786	  work. If unsure, go with the default, which is "Any".
2787
2788config PCI_GOBIOS
2789	bool "BIOS"
2790
2791config PCI_GOMMCONFIG
2792	bool "MMConfig"
2793
2794config PCI_GODIRECT
2795	bool "Direct"
2796
2797config PCI_GOOLPC
2798	bool "OLPC XO-1"
2799	depends on OLPC
2800
2801config PCI_GOANY
2802	bool "Any"
2803
2804endchoice
2805
2806config PCI_BIOS
2807	def_bool y
2808	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2809
2810# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2811config PCI_DIRECT
2812	def_bool y
2813	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2814
2815config PCI_MMCONFIG
2816	bool "Support mmconfig PCI config space access" if X86_64
2817	default y
2818	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2819	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2820
2821config PCI_OLPC
2822	def_bool y
2823	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2824
2825config PCI_XEN
2826	def_bool y
2827	depends on PCI && XEN
2828
2829config MMCONF_FAM10H
2830	def_bool y
2831	depends on X86_64 && PCI_MMCONFIG && ACPI
2832
2833config PCI_CNB20LE_QUIRK
2834	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2835	depends on PCI
2836	help
2837	  Read the PCI windows out of the CNB20LE host bridge. This allows
2838	  PCI hotplug to work on systems with the CNB20LE chipset which do
2839	  not have ACPI.
2840
2841	  There's no public spec for this chipset, and this functionality
2842	  is known to be incomplete.
2843
2844	  You should say N unless you know you need this.
2845
2846config ISA_BUS
2847	bool "ISA bus support on modern systems" if EXPERT
2848	help
2849	  Expose ISA bus device drivers and options available for selection and
2850	  configuration. Enable this option if your target machine has an ISA
2851	  bus. ISA is an older system, displaced by PCI and newer bus
2852	  architectures -- if your target machine is modern, it probably does
2853	  not have an ISA bus.
2854
2855	  If unsure, say N.
2856
2857# x86_64 have no ISA slots, but can have ISA-style DMA.
2858config ISA_DMA_API
2859	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2860	default y
2861	help
2862	  Enables ISA-style DMA support for devices requiring such controllers.
2863	  If unsure, say Y.
2864
2865if X86_32
2866
2867config ISA
2868	bool "ISA support"
2869	help
2870	  Find out whether you have ISA slots on your motherboard.  ISA is the
2871	  name of a bus system, i.e. the way the CPU talks to the other stuff
2872	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2873	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2874	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2875
2876config SCx200
2877	tristate "NatSemi SCx200 support"
2878	help
2879	  This provides basic support for National Semiconductor's
2880	  (now AMD's) Geode processors.  The driver probes for the
2881	  PCI-IDs of several on-chip devices, so its a good dependency
2882	  for other scx200_* drivers.
2883
2884	  If compiled as a module, the driver is named scx200.
2885
2886config SCx200HR_TIMER
2887	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2888	depends on SCx200
2889	default y
2890	help
2891	  This driver provides a clocksource built upon the on-chip
2892	  27MHz high-resolution timer.  Its also a workaround for
2893	  NSC Geode SC-1100's buggy TSC, which loses time when the
2894	  processor goes idle (as is done by the scheduler).  The
2895	  other workaround is idle=poll boot option.
2896
2897config OLPC
2898	bool "One Laptop Per Child support"
2899	depends on !X86_PAE
2900	select GPIOLIB
2901	select OF
2902	select OF_PROMTREE
2903	select IRQ_DOMAIN
2904	select OLPC_EC
2905	help
2906	  Add support for detecting the unique features of the OLPC
2907	  XO hardware.
2908
2909config OLPC_XO1_PM
2910	bool "OLPC XO-1 Power Management"
2911	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2912	help
2913	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2914
2915config OLPC_XO1_RTC
2916	bool "OLPC XO-1 Real Time Clock"
2917	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2918	help
2919	  Add support for the XO-1 real time clock, which can be used as a
2920	  programmable wakeup source.
2921
2922config OLPC_XO1_SCI
2923	bool "OLPC XO-1 SCI extras"
2924	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2925	depends on INPUT=y
2926	select POWER_SUPPLY
2927	help
2928	  Add support for SCI-based features of the OLPC XO-1 laptop:
2929	   - EC-driven system wakeups
2930	   - Power button
2931	   - Ebook switch
2932	   - Lid switch
2933	   - AC adapter status updates
2934	   - Battery status updates
2935
2936config OLPC_XO15_SCI
2937	bool "OLPC XO-1.5 SCI extras"
2938	depends on OLPC && ACPI
2939	select POWER_SUPPLY
2940	help
2941	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2942	   - EC-driven system wakeups
2943	   - AC adapter status updates
2944	   - Battery status updates
2945
2946config ALIX
2947	bool "PCEngines ALIX System Support (LED setup)"
2948	select GPIOLIB
2949	help
2950	  This option enables system support for the PCEngines ALIX.
2951	  At present this just sets up LEDs for GPIO control on
2952	  ALIX2/3/6 boards.  However, other system specific setup should
2953	  get added here.
2954
2955	  Note: You must still enable the drivers for GPIO and LED support
2956	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2957
2958	  Note: You have to set alix.force=1 for boards with Award BIOS.
2959
2960config NET5501
2961	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2962	select GPIOLIB
2963	help
2964	  This option enables system support for the Soekris Engineering net5501.
2965
2966config GEOS
2967	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2968	select GPIOLIB
2969	depends on DMI
2970	help
2971	  This option enables system support for the Traverse Technologies GEOS.
2972
2973config TS5500
2974	bool "Technologic Systems TS-5500 platform support"
2975	depends on MELAN
2976	select CHECK_SIGNATURE
2977	select NEW_LEDS
2978	select LEDS_CLASS
2979	help
2980	  This option enables system support for the Technologic Systems TS-5500.
2981
2982endif # X86_32
2983
2984config AMD_NB
2985	def_bool y
2986	depends on CPU_SUP_AMD && PCI
2987
2988endmenu
2989
2990menu "Binary Emulations"
2991
2992config IA32_EMULATION
2993	bool "IA32 Emulation"
2994	depends on X86_64
2995	select ARCH_WANT_OLD_COMPAT_IPC
2996	select BINFMT_ELF
2997	select COMPAT_OLD_SIGACTION
2998	help
2999	  Include code to run legacy 32-bit programs under a
3000	  64-bit kernel. You should likely turn this on, unless you're
3001	  100% sure that you don't have any 32-bit programs left.
3002
3003config IA32_EMULATION_DEFAULT_DISABLED
3004	bool "IA32 emulation disabled by default"
3005	default n
3006	depends on IA32_EMULATION
3007	help
3008	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3009	  processes and access to 32-bit syscalls. If unsure, leave it to its
3010	  default value.
3011
3012config X86_X32_ABI
3013	bool "x32 ABI for 64-bit mode"
3014	depends on X86_64
3015	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3016	# compressed debug sections to x86_x32 properly:
3017	# https://github.com/ClangBuiltLinux/linux/issues/514
3018	# https://github.com/ClangBuiltLinux/linux/issues/1141
3019	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3020	help
3021	  Include code to run binaries for the x32 native 32-bit ABI
3022	  for 64-bit processors.  An x32 process gets access to the
3023	  full 64-bit register file and wide data path while leaving
3024	  pointers at 32 bits for smaller memory footprint.
3025
3026config COMPAT_32
3027	def_bool y
3028	depends on IA32_EMULATION || X86_32
3029	select HAVE_UID16
3030	select OLD_SIGSUSPEND3
3031
3032config COMPAT
3033	def_bool y
3034	depends on IA32_EMULATION || X86_X32_ABI
3035
3036config COMPAT_FOR_U64_ALIGNMENT
3037	def_bool y
3038	depends on COMPAT
3039
3040endmenu
3041
3042config HAVE_ATOMIC_IOMAP
3043	def_bool y
3044	depends on X86_32
3045
3046source "arch/x86/kvm/Kconfig"
3047
3048source "arch/x86/Kconfig.assembler"
3049