xref: /openbmc/linux/arch/x86/Kconfig (revision de6e9190)
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_USE_CMPXCHG_LOCKREF
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 ARCH_32BIT_OFF_T			if X86_32
63	select ARCH_CLOCKSOURCE_INIT
64	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
65	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
66	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
67	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
68	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
69	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
70	select ARCH_HAS_CACHE_LINE_SIZE
71	select ARCH_HAS_DEBUG_VIRTUAL
72	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
73	select ARCH_HAS_DEVMEM_IS_ALLOWED
74	select ARCH_HAS_EARLY_DEBUG		if KGDB
75	select ARCH_HAS_ELF_RANDOMIZE
76	select ARCH_HAS_FAST_MULTIPLIER
77	select ARCH_HAS_FILTER_PGPROT
78	select ARCH_HAS_FORTIFY_SOURCE
79	select ARCH_HAS_GCOV_PROFILE_ALL
80	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
81	select ARCH_HAS_MEM_ENCRYPT
82	select ARCH_HAS_MEMBARRIER_SYNC_CORE
83	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
84	select ARCH_HAS_PMEM_API		if X86_64
85	select ARCH_HAS_PTE_DEVMAP		if X86_64
86	select ARCH_HAS_PTE_SPECIAL
87	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
88	select ARCH_HAS_COPY_MC			if X86_64
89	select ARCH_HAS_SET_MEMORY
90	select ARCH_HAS_SET_DIRECT_MAP
91	select ARCH_HAS_STRICT_KERNEL_RWX
92	select ARCH_HAS_STRICT_MODULE_RWX
93	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
94	select ARCH_HAS_SYSCALL_WRAPPER
95	select ARCH_HAS_UBSAN_SANITIZE_ALL
96	select ARCH_HAS_DEBUG_WX
97	select ARCH_HAS_ZONE_DMA_SET if EXPERT
98	select ARCH_HAVE_NMI_SAFE_CMPXCHG
99	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
100	select ARCH_MIGHT_HAVE_PC_PARPORT
101	select ARCH_MIGHT_HAVE_PC_SERIO
102	select ARCH_STACKWALK
103	select ARCH_SUPPORTS_ACPI
104	select ARCH_SUPPORTS_ATOMIC_RMW
105	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
106	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
107	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
108	select ARCH_SUPPORTS_LTO_CLANG
109	select ARCH_SUPPORTS_LTO_CLANG_THIN
110	select ARCH_USE_BUILTIN_BSWAP
111	select ARCH_USE_MEMTEST
112	select ARCH_USE_QUEUED_RWLOCKS
113	select ARCH_USE_QUEUED_SPINLOCKS
114	select ARCH_USE_SYM_ANNOTATIONS
115	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
116	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
117	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
118	select ARCH_WANTS_NO_INSTR
119	select ARCH_WANT_HUGE_PMD_SHARE
120	select ARCH_WANT_LD_ORPHAN_WARN
121	select ARCH_WANTS_THP_SWAP		if X86_64
122	select ARCH_HAS_PARANOID_L1D_FLUSH
123	select BUILDTIME_TABLE_SORT
124	select CLKEVT_I8253
125	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
126	select CLOCKSOURCE_WATCHDOG
127	select DCACHE_WORD_ACCESS
128	select EDAC_ATOMIC_SCRUB
129	select EDAC_SUPPORT
130	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
131	select GENERIC_CLOCKEVENTS_MIN_ADJUST
132	select GENERIC_CMOS_UPDATE
133	select GENERIC_CPU_AUTOPROBE
134	select GENERIC_CPU_VULNERABILITIES
135	select GENERIC_EARLY_IOREMAP
136	select GENERIC_ENTRY
137	select GENERIC_FIND_FIRST_BIT
138	select GENERIC_IOMAP
139	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
140	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
141	select GENERIC_IRQ_MIGRATION		if SMP
142	select GENERIC_IRQ_PROBE
143	select GENERIC_IRQ_RESERVATION_MODE
144	select GENERIC_IRQ_SHOW
145	select GENERIC_PENDING_IRQ		if SMP
146	select GENERIC_PTDUMP
147	select GENERIC_SMP_IDLE_THREAD
148	select GENERIC_TIME_VSYSCALL
149	select GENERIC_GETTIMEOFDAY
150	select GENERIC_VDSO_TIME_NS
151	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
152	select HARDIRQS_SW_RESEND
153	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
154	select HAVE_ACPI_APEI			if ACPI
155	select HAVE_ACPI_APEI_NMI		if ACPI
156	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
157	select HAVE_ARCH_AUDITSYSCALL
158	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
159	select HAVE_ARCH_JUMP_LABEL
160	select HAVE_ARCH_JUMP_LABEL_RELATIVE
161	select HAVE_ARCH_KASAN			if X86_64
162	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
163	select HAVE_ARCH_KFENCE
164	select HAVE_ARCH_KGDB
165	select HAVE_ARCH_MMAP_RND_BITS		if MMU
166	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
167	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
168	select HAVE_ARCH_PREL32_RELOCATIONS
169	select HAVE_ARCH_SECCOMP_FILTER
170	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
171	select HAVE_ARCH_STACKLEAK
172	select HAVE_ARCH_TRACEHOOK
173	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
174	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
175	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
176	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
177	select HAVE_ARCH_VMAP_STACK		if X86_64
178	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
179	select HAVE_ARCH_WITHIN_STACK_FRAMES
180	select HAVE_ASM_MODVERSIONS
181	select HAVE_CMPXCHG_DOUBLE
182	select HAVE_CMPXCHG_LOCAL
183	select HAVE_CONTEXT_TRACKING		if X86_64
184	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
185	select HAVE_C_RECORDMCOUNT
186	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
187	select HAVE_DEBUG_KMEMLEAK
188	select HAVE_DMA_CONTIGUOUS
189	select HAVE_DYNAMIC_FTRACE
190	select HAVE_DYNAMIC_FTRACE_WITH_REGS
191	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
192	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
193	select HAVE_EBPF_JIT
194	select HAVE_EFFICIENT_UNALIGNED_ACCESS
195	select HAVE_EISA
196	select HAVE_EXIT_THREAD
197	select HAVE_FAST_GUP
198	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
199	select HAVE_FTRACE_MCOUNT_RECORD
200	select HAVE_FUNCTION_GRAPH_TRACER
201	select HAVE_FUNCTION_TRACER
202	select HAVE_GCC_PLUGINS
203	select HAVE_HW_BREAKPOINT
204	select HAVE_IOREMAP_PROT
205	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
206	select HAVE_IRQ_TIME_ACCOUNTING
207	select HAVE_KERNEL_BZIP2
208	select HAVE_KERNEL_GZIP
209	select HAVE_KERNEL_LZ4
210	select HAVE_KERNEL_LZMA
211	select HAVE_KERNEL_LZO
212	select HAVE_KERNEL_XZ
213	select HAVE_KERNEL_ZSTD
214	select HAVE_KPROBES
215	select HAVE_KPROBES_ON_FTRACE
216	select HAVE_FUNCTION_ERROR_INJECTION
217	select HAVE_KRETPROBES
218	select HAVE_KVM
219	select HAVE_LIVEPATCH			if X86_64
220	select HAVE_MIXED_BREAKPOINTS_REGS
221	select HAVE_MOD_ARCH_SPECIFIC
222	select HAVE_MOVE_PMD
223	select HAVE_MOVE_PUD
224	select HAVE_NMI
225	select HAVE_OPTPROBES
226	select HAVE_PCSPKR_PLATFORM
227	select HAVE_PERF_EVENTS
228	select HAVE_PERF_EVENTS_NMI
229	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
230	select HAVE_PCI
231	select HAVE_PERF_REGS
232	select HAVE_PERF_USER_STACK_DUMP
233	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
234	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
235	select HAVE_REGS_AND_STACK_ACCESS_API
236	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
237	select HAVE_FUNCTION_ARG_ACCESS_API
238	select HAVE_SOFTIRQ_ON_OWN_STACK
239	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
240	select HAVE_STACK_VALIDATION		if X86_64
241	select HAVE_STATIC_CALL
242	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
243	select HAVE_PREEMPT_DYNAMIC
244	select HAVE_RSEQ
245	select HAVE_SYSCALL_TRACEPOINTS
246	select HAVE_UNSTABLE_SCHED_CLOCK
247	select HAVE_USER_RETURN_NOTIFIER
248	select HAVE_GENERIC_VDSO
249	select HOTPLUG_SMT			if SMP
250	select IRQ_FORCED_THREADING
251	select NEED_SG_DMA_LENGTH
252	select PCI_DOMAINS			if PCI
253	select PCI_LOCKLESS_CONFIG		if PCI
254	select PERF_EVENTS
255	select RTC_LIB
256	select RTC_MC146818_LIB
257	select SPARSE_IRQ
258	select SRCU
259	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
260	select SYSCTL_EXCEPTION_TRACE
261	select THREAD_INFO_IN_TASK
262	select TRACE_IRQFLAGS_SUPPORT
263	select USER_STACKTRACE_SUPPORT
264	select VIRT_TO_BUS
265	select HAVE_ARCH_KCSAN			if X86_64
266	select X86_FEATURE_NAMES		if PROC_FS
267	select PROC_PID_ARCH_STATUS		if PROC_FS
268	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
269
270config INSTRUCTION_DECODER
271	def_bool y
272	depends on KPROBES || PERF_EVENTS || UPROBES
273
274config OUTPUT_FORMAT
275	string
276	default "elf32-i386" if X86_32
277	default "elf64-x86-64" if X86_64
278
279config LOCKDEP_SUPPORT
280	def_bool y
281
282config STACKTRACE_SUPPORT
283	def_bool y
284
285config MMU
286	def_bool y
287
288config ARCH_MMAP_RND_BITS_MIN
289	default 28 if 64BIT
290	default 8
291
292config ARCH_MMAP_RND_BITS_MAX
293	default 32 if 64BIT
294	default 16
295
296config ARCH_MMAP_RND_COMPAT_BITS_MIN
297	default 8
298
299config ARCH_MMAP_RND_COMPAT_BITS_MAX
300	default 16
301
302config SBUS
303	bool
304
305config GENERIC_ISA_DMA
306	def_bool y
307	depends on ISA_DMA_API
308
309config GENERIC_BUG
310	def_bool y
311	depends on BUG
312	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
313
314config GENERIC_BUG_RELATIVE_POINTERS
315	bool
316
317config ARCH_MAY_HAVE_PC_FDC
318	def_bool y
319	depends on ISA_DMA_API
320
321config GENERIC_CALIBRATE_DELAY
322	def_bool y
323
324config ARCH_HAS_CPU_RELAX
325	def_bool y
326
327config ARCH_HAS_FILTER_PGPROT
328	def_bool y
329
330config HAVE_SETUP_PER_CPU_AREA
331	def_bool y
332
333config NEED_PER_CPU_EMBED_FIRST_CHUNK
334	def_bool y
335
336config NEED_PER_CPU_PAGE_FIRST_CHUNK
337	def_bool y
338
339config ARCH_HIBERNATION_POSSIBLE
340	def_bool y
341
342config ARCH_NR_GPIO
343	int
344	default 1024 if X86_64
345	default 512
346
347config ARCH_SUSPEND_POSSIBLE
348	def_bool y
349
350config ARCH_WANT_GENERAL_HUGETLB
351	def_bool y
352
353config AUDIT_ARCH
354	def_bool y if X86_64
355
356config KASAN_SHADOW_OFFSET
357	hex
358	depends on KASAN
359	default 0xdffffc0000000000
360
361config HAVE_INTEL_TXT
362	def_bool y
363	depends on INTEL_IOMMU && ACPI
364
365config X86_32_SMP
366	def_bool y
367	depends on X86_32 && SMP
368
369config X86_64_SMP
370	def_bool y
371	depends on X86_64 && SMP
372
373config ARCH_SUPPORTS_UPROBES
374	def_bool y
375
376config FIX_EARLYCON_MEM
377	def_bool y
378
379config DYNAMIC_PHYSICAL_MASK
380	bool
381
382config PGTABLE_LEVELS
383	int
384	default 5 if X86_5LEVEL
385	default 4 if X86_64
386	default 3 if X86_PAE
387	default 2
388
389config CC_HAS_SANE_STACKPROTECTOR
390	bool
391	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
392	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
393	help
394	   We have to make sure stack protector is unconditionally disabled if
395	   the compiler produces broken code or if it does not let us control
396	   the segment on 32-bit kernels.
397
398menu "Processor type and features"
399
400config SMP
401	bool "Symmetric multi-processing support"
402	help
403	  This enables support for systems with more than one CPU. If you have
404	  a system with only one CPU, say N. If you have a system with more
405	  than one CPU, say Y.
406
407	  If you say N here, the kernel will run on uni- and multiprocessor
408	  machines, but will use only one CPU of a multiprocessor machine. If
409	  you say Y here, the kernel will run on many, but not all,
410	  uniprocessor machines. On a uniprocessor machine, the kernel
411	  will run faster if you say N here.
412
413	  Note that if you say Y here and choose architecture "586" or
414	  "Pentium" under "Processor family", the kernel will not work on 486
415	  architectures. Similarly, multiprocessor kernels for the "PPro"
416	  architecture may not work on all Pentium based boards.
417
418	  People using multiprocessor machines who say Y here should also say
419	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
420	  Management" code will be disabled if you say Y here.
421
422	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
423	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
424	  <http://www.tldp.org/docs.html#howto>.
425
426	  If you don't know what to do here, say N.
427
428config X86_FEATURE_NAMES
429	bool "Processor feature human-readable names" if EMBEDDED
430	default y
431	help
432	  This option compiles in a table of x86 feature bits and corresponding
433	  names.  This is required to support /proc/cpuinfo and a few kernel
434	  messages.  You can disable this to save space, at the expense of
435	  making those few kernel messages show numeric feature bits instead.
436
437	  If in doubt, say Y.
438
439config X86_X2APIC
440	bool "Support x2apic"
441	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
442	help
443	  This enables x2apic support on CPUs that have this feature.
444
445	  This allows 32-bit apic IDs (so it can support very large systems),
446	  and accesses the local apic via MSRs not via mmio.
447
448	  If you don't know what to do here, say N.
449
450config X86_MPPARSE
451	bool "Enable MPS table" if ACPI
452	default y
453	depends on X86_LOCAL_APIC
454	help
455	  For old smp systems that do not have proper acpi support. Newer systems
456	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
457
458config GOLDFISH
459	def_bool y
460	depends on X86_GOLDFISH
461
462config RETPOLINE
463	bool "Avoid speculative indirect branches in kernel"
464	default y
465	help
466	  Compile kernel with the retpoline compiler options to guard against
467	  kernel-to-user data leaks by avoiding speculative indirect
468	  branches. Requires a compiler with -mindirect-branch=thunk-extern
469	  support for full protection. The kernel may run slower.
470
471config X86_CPU_RESCTRL
472	bool "x86 CPU resource control support"
473	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
474	select KERNFS
475	select PROC_CPU_RESCTRL		if PROC_FS
476	help
477	  Enable x86 CPU resource control support.
478
479	  Provide support for the allocation and monitoring of system resources
480	  usage by the CPU.
481
482	  Intel calls this Intel Resource Director Technology
483	  (Intel(R) RDT). More information about RDT can be found in the
484	  Intel x86 Architecture Software Developer Manual.
485
486	  AMD calls this AMD Platform Quality of Service (AMD QoS).
487	  More information about AMD QoS can be found in the AMD64 Technology
488	  Platform Quality of Service Extensions manual.
489
490	  Say N if unsure.
491
492if X86_32
493config X86_BIGSMP
494	bool "Support for big SMP systems with more than 8 CPUs"
495	depends on SMP
496	help
497	  This option is needed for the systems that have more than 8 CPUs.
498
499config X86_EXTENDED_PLATFORM
500	bool "Support for extended (non-PC) x86 platforms"
501	default y
502	help
503	  If you disable this option then the kernel will only support
504	  standard PC platforms. (which covers the vast majority of
505	  systems out there.)
506
507	  If you enable this option then you'll be able to select support
508	  for the following (non-PC) 32 bit x86 platforms:
509		Goldfish (Android emulator)
510		AMD Elan
511		RDC R-321x SoC
512		SGI 320/540 (Visual Workstation)
513		STA2X11-based (e.g. Northville)
514		Moorestown MID devices
515
516	  If you have one of these systems, or if you want to build a
517	  generic distribution kernel, say Y here - otherwise say N.
518endif
519
520if X86_64
521config X86_EXTENDED_PLATFORM
522	bool "Support for extended (non-PC) x86 platforms"
523	default y
524	help
525	  If you disable this option then the kernel will only support
526	  standard PC platforms. (which covers the vast majority of
527	  systems out there.)
528
529	  If you enable this option then you'll be able to select support
530	  for the following (non-PC) 64 bit x86 platforms:
531		Numascale NumaChip
532		ScaleMP vSMP
533		SGI Ultraviolet
534
535	  If you have one of these systems, or if you want to build a
536	  generic distribution kernel, say Y here - otherwise say N.
537endif
538# This is an alphabetically sorted list of 64 bit extended platforms
539# Please maintain the alphabetic order if and when there are additions
540config X86_NUMACHIP
541	bool "Numascale NumaChip"
542	depends on X86_64
543	depends on X86_EXTENDED_PLATFORM
544	depends on NUMA
545	depends on SMP
546	depends on X86_X2APIC
547	depends on PCI_MMCONFIG
548	help
549	  Adds support for Numascale NumaChip large-SMP systems. Needed to
550	  enable more than ~168 cores.
551	  If you don't have one of these, you should say N here.
552
553config X86_VSMP
554	bool "ScaleMP vSMP"
555	select HYPERVISOR_GUEST
556	select PARAVIRT
557	depends on X86_64 && PCI
558	depends on X86_EXTENDED_PLATFORM
559	depends on SMP
560	help
561	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
562	  supposed to run on these EM64T-based machines.  Only choose this option
563	  if you have one of these machines.
564
565config X86_UV
566	bool "SGI Ultraviolet"
567	depends on X86_64
568	depends on X86_EXTENDED_PLATFORM
569	depends on NUMA
570	depends on EFI
571	depends on KEXEC_CORE
572	depends on X86_X2APIC
573	depends on PCI
574	help
575	  This option is needed in order to support SGI Ultraviolet systems.
576	  If you don't have one of these, you should say N here.
577
578# Following is an alphabetically sorted list of 32 bit extended platforms
579# Please maintain the alphabetic order if and when there are additions
580
581config X86_GOLDFISH
582	bool "Goldfish (Virtual Platform)"
583	depends on X86_EXTENDED_PLATFORM
584	help
585	 Enable support for the Goldfish virtual platform used primarily
586	 for Android development. Unless you are building for the Android
587	 Goldfish emulator say N here.
588
589config X86_INTEL_CE
590	bool "CE4100 TV platform"
591	depends on PCI
592	depends on PCI_GODIRECT
593	depends on X86_IO_APIC
594	depends on X86_32
595	depends on X86_EXTENDED_PLATFORM
596	select X86_REBOOTFIXUPS
597	select OF
598	select OF_EARLY_FLATTREE
599	help
600	  Select for the Intel CE media processor (CE4100) SOC.
601	  This option compiles in support for the CE4100 SOC for settop
602	  boxes and media devices.
603
604config X86_INTEL_MID
605	bool "Intel MID platform support"
606	depends on X86_EXTENDED_PLATFORM
607	depends on X86_PLATFORM_DEVICES
608	depends on PCI
609	depends on X86_64 || (PCI_GOANY && X86_32)
610	depends on X86_IO_APIC
611	select I2C
612	select DW_APB_TIMER
613	select APB_TIMER
614	select INTEL_SCU_PCI
615	select MFD_INTEL_MSIC
616	help
617	  Select to build a kernel capable of supporting Intel MID (Mobile
618	  Internet Device) platform systems which do not have the PCI legacy
619	  interfaces. If you are building for a PC class system say N here.
620
621	  Intel MID platforms are based on an Intel processor and chipset which
622	  consume less power than most of the x86 derivatives.
623
624config X86_INTEL_QUARK
625	bool "Intel Quark platform support"
626	depends on X86_32
627	depends on X86_EXTENDED_PLATFORM
628	depends on X86_PLATFORM_DEVICES
629	depends on X86_TSC
630	depends on PCI
631	depends on PCI_GOANY
632	depends on X86_IO_APIC
633	select IOSF_MBI
634	select INTEL_IMR
635	select COMMON_CLK
636	help
637	  Select to include support for Quark X1000 SoC.
638	  Say Y here if you have a Quark based system such as the Arduino
639	  compatible Intel Galileo.
640
641config X86_INTEL_LPSS
642	bool "Intel Low Power Subsystem Support"
643	depends on X86 && ACPI && PCI
644	select COMMON_CLK
645	select PINCTRL
646	select IOSF_MBI
647	help
648	  Select to build support for Intel Low Power Subsystem such as
649	  found on Intel Lynxpoint PCH. Selecting this option enables
650	  things like clock tree (common clock framework) and pincontrol
651	  which are needed by the LPSS peripheral drivers.
652
653config X86_AMD_PLATFORM_DEVICE
654	bool "AMD ACPI2Platform devices support"
655	depends on ACPI
656	select COMMON_CLK
657	select PINCTRL
658	help
659	  Select to interpret AMD specific ACPI device to platform device
660	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
661	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
662	  implemented under PINCTRL subsystem.
663
664config IOSF_MBI
665	tristate "Intel SoC IOSF Sideband support for SoC platforms"
666	depends on PCI
667	help
668	  This option enables sideband register access support for Intel SoC
669	  platforms. On these platforms the IOSF sideband is used in lieu of
670	  MSR's for some register accesses, mostly but not limited to thermal
671	  and power. Drivers may query the availability of this device to
672	  determine if they need the sideband in order to work on these
673	  platforms. The sideband is available on the following SoC products.
674	  This list is not meant to be exclusive.
675	   - BayTrail
676	   - Braswell
677	   - Quark
678
679	  You should say Y if you are running a kernel on one of these SoC's.
680
681config IOSF_MBI_DEBUG
682	bool "Enable IOSF sideband access through debugfs"
683	depends on IOSF_MBI && DEBUG_FS
684	help
685	  Select this option to expose the IOSF sideband access registers (MCR,
686	  MDR, MCRX) through debugfs to write and read register information from
687	  different units on the SoC. This is most useful for obtaining device
688	  state information for debug and analysis. As this is a general access
689	  mechanism, users of this option would have specific knowledge of the
690	  device they want to access.
691
692	  If you don't require the option or are in doubt, say N.
693
694config X86_RDC321X
695	bool "RDC R-321x SoC"
696	depends on X86_32
697	depends on X86_EXTENDED_PLATFORM
698	select M486
699	select X86_REBOOTFIXUPS
700	help
701	  This option is needed for RDC R-321x system-on-chip, also known
702	  as R-8610-(G).
703	  If you don't have one of these chips, you should say N here.
704
705config X86_32_NON_STANDARD
706	bool "Support non-standard 32-bit SMP architectures"
707	depends on X86_32 && SMP
708	depends on X86_EXTENDED_PLATFORM
709	help
710	  This option compiles in the bigsmp and STA2X11 default
711	  subarchitectures.  It is intended for a generic binary
712	  kernel. If you select them all, kernel will probe it one by
713	  one and will fallback to default.
714
715# Alphabetically sorted list of Non standard 32 bit platforms
716
717config X86_SUPPORTS_MEMORY_FAILURE
718	def_bool y
719	# MCE code calls memory_failure():
720	depends on X86_MCE
721	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
722	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
723	depends on X86_64 || !SPARSEMEM
724	select ARCH_SUPPORTS_MEMORY_FAILURE
725
726config STA2X11
727	bool "STA2X11 Companion Chip Support"
728	depends on X86_32_NON_STANDARD && PCI
729	select SWIOTLB
730	select MFD_STA2X11
731	select GPIOLIB
732	help
733	  This adds support for boards based on the STA2X11 IO-Hub,
734	  a.k.a. "ConneXt". The chip is used in place of the standard
735	  PC chipset, so all "standard" peripherals are missing. If this
736	  option is selected the kernel will still be able to boot on
737	  standard PC machines.
738
739config X86_32_IRIS
740	tristate "Eurobraille/Iris poweroff module"
741	depends on X86_32
742	help
743	  The Iris machines from EuroBraille do not have APM or ACPI support
744	  to shut themselves down properly.  A special I/O sequence is
745	  needed to do so, which is what this module does at
746	  kernel shutdown.
747
748	  This is only for Iris machines from EuroBraille.
749
750	  If unused, say N.
751
752config SCHED_OMIT_FRAME_POINTER
753	def_bool y
754	prompt "Single-depth WCHAN output"
755	depends on X86
756	help
757	  Calculate simpler /proc/<PID>/wchan values. If this option
758	  is disabled then wchan values will recurse back to the
759	  caller function. This provides more accurate wchan values,
760	  at the expense of slightly more scheduling overhead.
761
762	  If in doubt, say "Y".
763
764menuconfig HYPERVISOR_GUEST
765	bool "Linux guest support"
766	help
767	  Say Y here to enable options for running Linux under various hyper-
768	  visors. This option enables basic hypervisor detection and platform
769	  setup.
770
771	  If you say N, all options in this submenu will be skipped and
772	  disabled, and Linux guest support won't be built in.
773
774if HYPERVISOR_GUEST
775
776config PARAVIRT
777	bool "Enable paravirtualization code"
778	depends on HAVE_STATIC_CALL
779	help
780	  This changes the kernel so it can modify itself when it is run
781	  under a hypervisor, potentially improving performance significantly
782	  over full virtualization.  However, when run without a hypervisor
783	  the kernel is theoretically slower and slightly larger.
784
785config PARAVIRT_XXL
786	bool
787
788config PARAVIRT_DEBUG
789	bool "paravirt-ops debugging"
790	depends on PARAVIRT && DEBUG_KERNEL
791	help
792	  Enable to debug paravirt_ops internals.  Specifically, BUG if
793	  a paravirt_op is missing when it is called.
794
795config PARAVIRT_SPINLOCKS
796	bool "Paravirtualization layer for spinlocks"
797	depends on PARAVIRT && SMP
798	help
799	  Paravirtualized spinlocks allow a pvops backend to replace the
800	  spinlock implementation with something virtualization-friendly
801	  (for example, block the virtual CPU rather than spinning).
802
803	  It has a minimal impact on native kernels and gives a nice performance
804	  benefit on paravirtualized KVM / Xen kernels.
805
806	  If you are unsure how to answer this question, answer Y.
807
808config X86_HV_CALLBACK_VECTOR
809	def_bool n
810
811source "arch/x86/xen/Kconfig"
812
813config KVM_GUEST
814	bool "KVM Guest support (including kvmclock)"
815	depends on PARAVIRT
816	select PARAVIRT_CLOCK
817	select ARCH_CPUIDLE_HALTPOLL
818	select X86_HV_CALLBACK_VECTOR
819	default y
820	help
821	  This option enables various optimizations for running under the KVM
822	  hypervisor. It includes a paravirtualized clock, so that instead
823	  of relying on a PIT (or probably other) emulation by the
824	  underlying device model, the host provides the guest with
825	  timing infrastructure such as time of day, and system time
826
827config ARCH_CPUIDLE_HALTPOLL
828	def_bool n
829	prompt "Disable host haltpoll when loading haltpoll driver"
830	help
831	  If virtualized under KVM, disable host haltpoll.
832
833config PVH
834	bool "Support for running PVH guests"
835	help
836	  This option enables the PVH entry point for guest virtual machines
837	  as specified in the x86/HVM direct boot ABI.
838
839config PARAVIRT_TIME_ACCOUNTING
840	bool "Paravirtual steal time accounting"
841	depends on PARAVIRT
842	help
843	  Select this option to enable fine granularity task steal time
844	  accounting. Time spent executing other tasks in parallel with
845	  the current vCPU is discounted from the vCPU power. To account for
846	  that, there can be a small performance impact.
847
848	  If in doubt, say N here.
849
850config PARAVIRT_CLOCK
851	bool
852
853config JAILHOUSE_GUEST
854	bool "Jailhouse non-root cell support"
855	depends on X86_64 && PCI
856	select X86_PM_TIMER
857	help
858	  This option allows to run Linux as guest in a Jailhouse non-root
859	  cell. You can leave this option disabled if you only want to start
860	  Jailhouse and run Linux afterwards in the root cell.
861
862config ACRN_GUEST
863	bool "ACRN Guest support"
864	depends on X86_64
865	select X86_HV_CALLBACK_VECTOR
866	help
867	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
868	  a flexible, lightweight reference open-source hypervisor, built with
869	  real-time and safety-criticality in mind. It is built for embedded
870	  IOT with small footprint and real-time features. More details can be
871	  found in https://projectacrn.org/.
872
873endif #HYPERVISOR_GUEST
874
875source "arch/x86/Kconfig.cpu"
876
877config HPET_TIMER
878	def_bool X86_64
879	prompt "HPET Timer Support" if X86_32
880	help
881	  Use the IA-PC HPET (High Precision Event Timer) to manage
882	  time in preference to the PIT and RTC, if a HPET is
883	  present.
884	  HPET is the next generation timer replacing legacy 8254s.
885	  The HPET provides a stable time base on SMP
886	  systems, unlike the TSC, but it is more expensive to access,
887	  as it is off-chip.  The interface used is documented
888	  in the HPET spec, revision 1.
889
890	  You can safely choose Y here.  However, HPET will only be
891	  activated if the platform and the BIOS support this feature.
892	  Otherwise the 8254 will be used for timing services.
893
894	  Choose N to continue using the legacy 8254 timer.
895
896config HPET_EMULATE_RTC
897	def_bool y
898	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
899
900# Mark as expert because too many people got it wrong.
901# The code disables itself when not needed.
902config DMI
903	default y
904	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
905	bool "Enable DMI scanning" if EXPERT
906	help
907	  Enabled scanning of DMI to identify machine quirks. Say Y
908	  here unless you have verified that your setup is not
909	  affected by entries in the DMI blacklist. Required by PNP
910	  BIOS code.
911
912config GART_IOMMU
913	bool "Old AMD GART IOMMU support"
914	select DMA_OPS
915	select IOMMU_HELPER
916	select SWIOTLB
917	depends on X86_64 && PCI && AMD_NB
918	help
919	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
920	  GART based hardware IOMMUs.
921
922	  The GART supports full DMA access for devices with 32-bit access
923	  limitations, on systems with more than 3 GB. This is usually needed
924	  for USB, sound, many IDE/SATA chipsets and some other devices.
925
926	  Newer systems typically have a modern AMD IOMMU, supported via
927	  the CONFIG_AMD_IOMMU=y config option.
928
929	  In normal configurations this driver is only active when needed:
930	  there's more than 3 GB of memory and the system contains a
931	  32-bit limited device.
932
933	  If unsure, say Y.
934
935config MAXSMP
936	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
937	depends on X86_64 && SMP && DEBUG_KERNEL
938	select CPUMASK_OFFSTACK
939	help
940	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
941	  If unsure, say N.
942
943#
944# The maximum number of CPUs supported:
945#
946# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
947# and which can be configured interactively in the
948# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
949#
950# The ranges are different on 32-bit and 64-bit kernels, depending on
951# hardware capabilities and scalability features of the kernel.
952#
953# ( If MAXSMP is enabled we just use the highest possible value and disable
954#   interactive configuration. )
955#
956
957config NR_CPUS_RANGE_BEGIN
958	int
959	default NR_CPUS_RANGE_END if MAXSMP
960	default    1 if !SMP
961	default    2
962
963config NR_CPUS_RANGE_END
964	int
965	depends on X86_32
966	default   64 if  SMP &&  X86_BIGSMP
967	default    8 if  SMP && !X86_BIGSMP
968	default    1 if !SMP
969
970config NR_CPUS_RANGE_END
971	int
972	depends on X86_64
973	default 8192 if  SMP && CPUMASK_OFFSTACK
974	default  512 if  SMP && !CPUMASK_OFFSTACK
975	default    1 if !SMP
976
977config NR_CPUS_DEFAULT
978	int
979	depends on X86_32
980	default   32 if  X86_BIGSMP
981	default    8 if  SMP
982	default    1 if !SMP
983
984config NR_CPUS_DEFAULT
985	int
986	depends on X86_64
987	default 8192 if  MAXSMP
988	default   64 if  SMP
989	default    1 if !SMP
990
991config NR_CPUS
992	int "Maximum number of CPUs" if SMP && !MAXSMP
993	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
994	default NR_CPUS_DEFAULT
995	help
996	  This allows you to specify the maximum number of CPUs which this
997	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
998	  supported value is 8192, otherwise the maximum value is 512.  The
999	  minimum value which makes sense is 2.
1000
1001	  This is purely to save memory: each supported CPU adds about 8KB
1002	  to the kernel image.
1003
1004config SCHED_SMT
1005	def_bool y if SMP
1006
1007config SCHED_MC
1008	def_bool y
1009	prompt "Multi-core scheduler support"
1010	depends on SMP
1011	help
1012	  Multi-core scheduler support improves the CPU scheduler's decision
1013	  making when dealing with multi-core CPU chips at a cost of slightly
1014	  increased overhead in some places. If unsure say N here.
1015
1016config SCHED_MC_PRIO
1017	bool "CPU core priorities scheduler support"
1018	depends on SCHED_MC && CPU_SUP_INTEL
1019	select X86_INTEL_PSTATE
1020	select CPU_FREQ
1021	default y
1022	help
1023	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1024	  core ordering determined at manufacturing time, which allows
1025	  certain cores to reach higher turbo frequencies (when running
1026	  single threaded workloads) than others.
1027
1028	  Enabling this kernel feature teaches the scheduler about
1029	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1030	  scheduler's CPU selection logic accordingly, so that higher
1031	  overall system performance can be achieved.
1032
1033	  This feature will have no effect on CPUs without this feature.
1034
1035	  If unsure say Y here.
1036
1037config UP_LATE_INIT
1038	def_bool y
1039	depends on !SMP && X86_LOCAL_APIC
1040
1041config X86_UP_APIC
1042	bool "Local APIC support on uniprocessors" if !PCI_MSI
1043	default PCI_MSI
1044	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1045	help
1046	  A local APIC (Advanced Programmable Interrupt Controller) is an
1047	  integrated interrupt controller in the CPU. If you have a single-CPU
1048	  system which has a processor with a local APIC, you can say Y here to
1049	  enable and use it. If you say Y here even though your machine doesn't
1050	  have a local APIC, then the kernel will still run with no slowdown at
1051	  all. The local APIC supports CPU-generated self-interrupts (timer,
1052	  performance counters), and the NMI watchdog which detects hard
1053	  lockups.
1054
1055config X86_UP_IOAPIC
1056	bool "IO-APIC support on uniprocessors"
1057	depends on X86_UP_APIC
1058	help
1059	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1060	  SMP-capable replacement for PC-style interrupt controllers. Most
1061	  SMP systems and many recent uniprocessor systems have one.
1062
1063	  If you have a single-CPU system with an IO-APIC, you can say Y here
1064	  to use it. If you say Y here even though your machine doesn't have
1065	  an IO-APIC, then the kernel will still run with no slowdown at all.
1066
1067config X86_LOCAL_APIC
1068	def_bool y
1069	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1070	select IRQ_DOMAIN_HIERARCHY
1071	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1072
1073config X86_IO_APIC
1074	def_bool y
1075	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1076
1077config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1078	bool "Reroute for broken boot IRQs"
1079	depends on X86_IO_APIC
1080	help
1081	  This option enables a workaround that fixes a source of
1082	  spurious interrupts. This is recommended when threaded
1083	  interrupt handling is used on systems where the generation of
1084	  superfluous "boot interrupts" cannot be disabled.
1085
1086	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1087	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1088	  kernel does during interrupt handling). On chipsets where this
1089	  boot IRQ generation cannot be disabled, this workaround keeps
1090	  the original IRQ line masked so that only the equivalent "boot
1091	  IRQ" is delivered to the CPUs. The workaround also tells the
1092	  kernel to set up the IRQ handler on the boot IRQ line. In this
1093	  way only one interrupt is delivered to the kernel. Otherwise
1094	  the spurious second interrupt may cause the kernel to bring
1095	  down (vital) interrupt lines.
1096
1097	  Only affects "broken" chipsets. Interrupt sharing may be
1098	  increased on these systems.
1099
1100config X86_MCE
1101	bool "Machine Check / overheating reporting"
1102	select GENERIC_ALLOCATOR
1103	default y
1104	help
1105	  Machine Check support allows the processor to notify the
1106	  kernel if it detects a problem (e.g. overheating, data corruption).
1107	  The action the kernel takes depends on the severity of the problem,
1108	  ranging from warning messages to halting the machine.
1109
1110config X86_MCELOG_LEGACY
1111	bool "Support for deprecated /dev/mcelog character device"
1112	depends on X86_MCE
1113	help
1114	  Enable support for /dev/mcelog which is needed by the old mcelog
1115	  userspace logging daemon. Consider switching to the new generation
1116	  rasdaemon solution.
1117
1118config X86_MCE_INTEL
1119	def_bool y
1120	prompt "Intel MCE features"
1121	depends on X86_MCE && X86_LOCAL_APIC
1122	help
1123	   Additional support for intel specific MCE features such as
1124	   the thermal monitor.
1125
1126config X86_MCE_AMD
1127	def_bool y
1128	prompt "AMD MCE features"
1129	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1130	help
1131	   Additional support for AMD specific MCE features such as
1132	   the DRAM Error Threshold.
1133
1134config X86_ANCIENT_MCE
1135	bool "Support for old Pentium 5 / WinChip machine checks"
1136	depends on X86_32 && X86_MCE
1137	help
1138	  Include support for machine check handling on old Pentium 5 or WinChip
1139	  systems. These typically need to be enabled explicitly on the command
1140	  line.
1141
1142config X86_MCE_THRESHOLD
1143	depends on X86_MCE_AMD || X86_MCE_INTEL
1144	def_bool y
1145
1146config X86_MCE_INJECT
1147	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1148	tristate "Machine check injector support"
1149	help
1150	  Provide support for injecting machine checks for testing purposes.
1151	  If you don't know what a machine check is and you don't do kernel
1152	  QA it is safe to say n.
1153
1154source "arch/x86/events/Kconfig"
1155
1156config X86_LEGACY_VM86
1157	bool "Legacy VM86 support"
1158	depends on X86_32
1159	help
1160	  This option allows user programs to put the CPU into V8086
1161	  mode, which is an 80286-era approximation of 16-bit real mode.
1162
1163	  Some very old versions of X and/or vbetool require this option
1164	  for user mode setting.  Similarly, DOSEMU will use it if
1165	  available to accelerate real mode DOS programs.  However, any
1166	  recent version of DOSEMU, X, or vbetool should be fully
1167	  functional even without kernel VM86 support, as they will all
1168	  fall back to software emulation. Nevertheless, if you are using
1169	  a 16-bit DOS program where 16-bit performance matters, vm86
1170	  mode might be faster than emulation and you might want to
1171	  enable this option.
1172
1173	  Note that any app that works on a 64-bit kernel is unlikely to
1174	  need this option, as 64-bit kernels don't, and can't, support
1175	  V8086 mode. This option is also unrelated to 16-bit protected
1176	  mode and is not needed to run most 16-bit programs under Wine.
1177
1178	  Enabling this option increases the complexity of the kernel
1179	  and slows down exception handling a tiny bit.
1180
1181	  If unsure, say N here.
1182
1183config VM86
1184	bool
1185	default X86_LEGACY_VM86
1186
1187config X86_16BIT
1188	bool "Enable support for 16-bit segments" if EXPERT
1189	default y
1190	depends on MODIFY_LDT_SYSCALL
1191	help
1192	  This option is required by programs like Wine to run 16-bit
1193	  protected mode legacy code on x86 processors.  Disabling
1194	  this option saves about 300 bytes on i386, or around 6K text
1195	  plus 16K runtime memory on x86-64,
1196
1197config X86_ESPFIX32
1198	def_bool y
1199	depends on X86_16BIT && X86_32
1200
1201config X86_ESPFIX64
1202	def_bool y
1203	depends on X86_16BIT && X86_64
1204
1205config X86_VSYSCALL_EMULATION
1206	bool "Enable vsyscall emulation" if EXPERT
1207	default y
1208	depends on X86_64
1209	help
1210	 This enables emulation of the legacy vsyscall page.  Disabling
1211	 it is roughly equivalent to booting with vsyscall=none, except
1212	 that it will also disable the helpful warning if a program
1213	 tries to use a vsyscall.  With this option set to N, offending
1214	 programs will just segfault, citing addresses of the form
1215	 0xffffffffff600?00.
1216
1217	 This option is required by many programs built before 2013, and
1218	 care should be used even with newer programs if set to N.
1219
1220	 Disabling this option saves about 7K of kernel size and
1221	 possibly 4K of additional runtime pagetable memory.
1222
1223config X86_IOPL_IOPERM
1224	bool "IOPERM and IOPL Emulation"
1225	default y
1226	help
1227	  This enables the ioperm() and iopl() syscalls which are necessary
1228	  for legacy applications.
1229
1230	  Legacy IOPL support is an overbroad mechanism which allows user
1231	  space aside of accessing all 65536 I/O ports also to disable
1232	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1233	  capabilities and permission from potentially active security
1234	  modules.
1235
1236	  The emulation restricts the functionality of the syscall to
1237	  only allowing the full range I/O port access, but prevents the
1238	  ability to disable interrupts from user space which would be
1239	  granted if the hardware IOPL mechanism would be used.
1240
1241config TOSHIBA
1242	tristate "Toshiba Laptop support"
1243	depends on X86_32
1244	help
1245	  This adds a driver to safely access the System Management Mode of
1246	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1247	  not work on models with a Phoenix BIOS. The System Management Mode
1248	  is used to set the BIOS and power saving options on Toshiba portables.
1249
1250	  For information on utilities to make use of this driver see the
1251	  Toshiba Linux utilities web site at:
1252	  <http://www.buzzard.org.uk/toshiba/>.
1253
1254	  Say Y if you intend to run this kernel on a Toshiba portable.
1255	  Say N otherwise.
1256
1257config I8K
1258	tristate "Dell i8k legacy laptop support"
1259	select HWMON
1260	select SENSORS_DELL_SMM
1261	help
1262	  This option enables legacy /proc/i8k userspace interface in hwmon
1263	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1264	  temperature and allows controlling fan speeds of Dell laptops via
1265	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1266	  it reports also power and hotkey status. For fan speed control is
1267	  needed userspace package i8kutils.
1268
1269	  Say Y if you intend to run this kernel on old Dell laptops or want to
1270	  use userspace package i8kutils.
1271	  Say N otherwise.
1272
1273config X86_REBOOTFIXUPS
1274	bool "Enable X86 board specific fixups for reboot"
1275	depends on X86_32
1276	help
1277	  This enables chipset and/or board specific fixups to be done
1278	  in order to get reboot to work correctly. This is only needed on
1279	  some combinations of hardware and BIOS. The symptom, for which
1280	  this config is intended, is when reboot ends with a stalled/hung
1281	  system.
1282
1283	  Currently, the only fixup is for the Geode machines using
1284	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1285
1286	  Say Y if you want to enable the fixup. Currently, it's safe to
1287	  enable this option even if you don't need it.
1288	  Say N otherwise.
1289
1290config MICROCODE
1291	bool "CPU microcode loading support"
1292	default y
1293	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1294	help
1295	  If you say Y here, you will be able to update the microcode on
1296	  Intel and AMD processors. The Intel support is for the IA32 family,
1297	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1298	  AMD support is for families 0x10 and later. You will obviously need
1299	  the actual microcode binary data itself which is not shipped with
1300	  the Linux kernel.
1301
1302	  The preferred method to load microcode from a detached initrd is described
1303	  in Documentation/x86/microcode.rst. For that you need to enable
1304	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1305	  initrd for microcode blobs.
1306
1307	  In addition, you can build the microcode into the kernel. For that you
1308	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1309	  config option.
1310
1311config MICROCODE_INTEL
1312	bool "Intel microcode loading support"
1313	depends on MICROCODE
1314	default MICROCODE
1315	help
1316	  This options enables microcode patch loading support for Intel
1317	  processors.
1318
1319	  For the current Intel microcode data package go to
1320	  <https://downloadcenter.intel.com> and search for
1321	  'Linux Processor Microcode Data File'.
1322
1323config MICROCODE_AMD
1324	bool "AMD microcode loading support"
1325	depends on MICROCODE
1326	help
1327	  If you select this option, microcode patch loading support for AMD
1328	  processors will be enabled.
1329
1330config MICROCODE_OLD_INTERFACE
1331	bool "Ancient loading interface (DEPRECATED)"
1332	default n
1333	depends on MICROCODE
1334	help
1335	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1336	  which was used by userspace tools like iucode_tool and microcode.ctl.
1337	  It is inadequate because it runs too late to be able to properly
1338	  load microcode on a machine and it needs special tools. Instead, you
1339	  should've switched to the early loading method with the initrd or
1340	  builtin microcode by now: Documentation/x86/microcode.rst
1341
1342config X86_MSR
1343	tristate "/dev/cpu/*/msr - Model-specific register support"
1344	help
1345	  This device gives privileged processes access to the x86
1346	  Model-Specific Registers (MSRs).  It is a character device with
1347	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1348	  MSR accesses are directed to a specific CPU on multi-processor
1349	  systems.
1350
1351config X86_CPUID
1352	tristate "/dev/cpu/*/cpuid - CPU information support"
1353	help
1354	  This device gives processes access to the x86 CPUID instruction to
1355	  be executed on a specific processor.  It is a character device
1356	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1357	  /dev/cpu/31/cpuid.
1358
1359choice
1360	prompt "High Memory Support"
1361	default HIGHMEM4G
1362	depends on X86_32
1363
1364config NOHIGHMEM
1365	bool "off"
1366	help
1367	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1368	  However, the address space of 32-bit x86 processors is only 4
1369	  Gigabytes large. That means that, if you have a large amount of
1370	  physical memory, not all of it can be "permanently mapped" by the
1371	  kernel. The physical memory that's not permanently mapped is called
1372	  "high memory".
1373
1374	  If you are compiling a kernel which will never run on a machine with
1375	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1376	  choice and suitable for most users). This will result in a "3GB/1GB"
1377	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1378	  space and the remaining part of the 4GB virtual memory space is used
1379	  by the kernel to permanently map as much physical memory as
1380	  possible.
1381
1382	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1383	  answer "4GB" here.
1384
1385	  If more than 4 Gigabytes is used then answer "64GB" here. This
1386	  selection turns Intel PAE (Physical Address Extension) mode on.
1387	  PAE implements 3-level paging on IA32 processors. PAE is fully
1388	  supported by Linux, PAE mode is implemented on all recent Intel
1389	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1390	  then the kernel will not boot on CPUs that don't support PAE!
1391
1392	  The actual amount of total physical memory will either be
1393	  auto detected or can be forced by using a kernel command line option
1394	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1395	  your boot loader (lilo or loadlin) about how to pass options to the
1396	  kernel at boot time.)
1397
1398	  If unsure, say "off".
1399
1400config HIGHMEM4G
1401	bool "4GB"
1402	help
1403	  Select this if you have a 32-bit processor and between 1 and 4
1404	  gigabytes of physical RAM.
1405
1406config HIGHMEM64G
1407	bool "64GB"
1408	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1409	select X86_PAE
1410	help
1411	  Select this if you have a 32-bit processor and more than 4
1412	  gigabytes of physical RAM.
1413
1414endchoice
1415
1416choice
1417	prompt "Memory split" if EXPERT
1418	default VMSPLIT_3G
1419	depends on X86_32
1420	help
1421	  Select the desired split between kernel and user memory.
1422
1423	  If the address range available to the kernel is less than the
1424	  physical memory installed, the remaining memory will be available
1425	  as "high memory". Accessing high memory is a little more costly
1426	  than low memory, as it needs to be mapped into the kernel first.
1427	  Note that increasing the kernel address space limits the range
1428	  available to user programs, making the address space there
1429	  tighter.  Selecting anything other than the default 3G/1G split
1430	  will also likely make your kernel incompatible with binary-only
1431	  kernel modules.
1432
1433	  If you are not absolutely sure what you are doing, leave this
1434	  option alone!
1435
1436	config VMSPLIT_3G
1437		bool "3G/1G user/kernel split"
1438	config VMSPLIT_3G_OPT
1439		depends on !X86_PAE
1440		bool "3G/1G user/kernel split (for full 1G low memory)"
1441	config VMSPLIT_2G
1442		bool "2G/2G user/kernel split"
1443	config VMSPLIT_2G_OPT
1444		depends on !X86_PAE
1445		bool "2G/2G user/kernel split (for full 2G low memory)"
1446	config VMSPLIT_1G
1447		bool "1G/3G user/kernel split"
1448endchoice
1449
1450config PAGE_OFFSET
1451	hex
1452	default 0xB0000000 if VMSPLIT_3G_OPT
1453	default 0x80000000 if VMSPLIT_2G
1454	default 0x78000000 if VMSPLIT_2G_OPT
1455	default 0x40000000 if VMSPLIT_1G
1456	default 0xC0000000
1457	depends on X86_32
1458
1459config HIGHMEM
1460	def_bool y
1461	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1462
1463config X86_PAE
1464	bool "PAE (Physical Address Extension) Support"
1465	depends on X86_32 && !HIGHMEM4G
1466	select PHYS_ADDR_T_64BIT
1467	select SWIOTLB
1468	help
1469	  PAE is required for NX support, and furthermore enables
1470	  larger swapspace support for non-overcommit purposes. It
1471	  has the cost of more pagetable lookup overhead, and also
1472	  consumes more pagetable space per process.
1473
1474config X86_5LEVEL
1475	bool "Enable 5-level page tables support"
1476	default y
1477	select DYNAMIC_MEMORY_LAYOUT
1478	select SPARSEMEM_VMEMMAP
1479	depends on X86_64
1480	help
1481	  5-level paging enables access to larger address space:
1482	  upto 128 PiB of virtual address space and 4 PiB of
1483	  physical address space.
1484
1485	  It will be supported by future Intel CPUs.
1486
1487	  A kernel with the option enabled can be booted on machines that
1488	  support 4- or 5-level paging.
1489
1490	  See Documentation/x86/x86_64/5level-paging.rst for more
1491	  information.
1492
1493	  Say N if unsure.
1494
1495config X86_DIRECT_GBPAGES
1496	def_bool y
1497	depends on X86_64
1498	help
1499	  Certain kernel features effectively disable kernel
1500	  linear 1 GB mappings (even if the CPU otherwise
1501	  supports them), so don't confuse the user by printing
1502	  that we have them enabled.
1503
1504config X86_CPA_STATISTICS
1505	bool "Enable statistic for Change Page Attribute"
1506	depends on DEBUG_FS
1507	help
1508	  Expose statistics about the Change Page Attribute mechanism, which
1509	  helps to determine the effectiveness of preserving large and huge
1510	  page mappings when mapping protections are changed.
1511
1512config AMD_MEM_ENCRYPT
1513	bool "AMD Secure Memory Encryption (SME) support"
1514	depends on X86_64 && CPU_SUP_AMD
1515	select DMA_COHERENT_POOL
1516	select DYNAMIC_PHYSICAL_MASK
1517	select ARCH_USE_MEMREMAP_PROT
1518	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1519	select INSTRUCTION_DECODER
1520	select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
1521	help
1522	  Say yes to enable support for the encryption of system memory.
1523	  This requires an AMD processor that supports Secure Memory
1524	  Encryption (SME).
1525
1526config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1527	bool "Activate AMD Secure Memory Encryption (SME) by default"
1528	depends on AMD_MEM_ENCRYPT
1529	help
1530	  Say yes to have system memory encrypted by default if running on
1531	  an AMD processor that supports Secure Memory Encryption (SME).
1532
1533	  If set to Y, then the encryption of system memory can be
1534	  deactivated with the mem_encrypt=off command line option.
1535
1536	  If set to N, then the encryption of system memory can be
1537	  activated with the mem_encrypt=on command line option.
1538
1539# Common NUMA Features
1540config NUMA
1541	bool "NUMA Memory Allocation and Scheduler Support"
1542	depends on SMP
1543	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1544	default y if X86_BIGSMP
1545	help
1546	  Enable NUMA (Non-Uniform Memory Access) support.
1547
1548	  The kernel will try to allocate memory used by a CPU on the
1549	  local memory controller of the CPU and add some more
1550	  NUMA awareness to the kernel.
1551
1552	  For 64-bit this is recommended if the system is Intel Core i7
1553	  (or later), AMD Opteron, or EM64T NUMA.
1554
1555	  For 32-bit this is only needed if you boot a 32-bit
1556	  kernel on a 64-bit NUMA platform.
1557
1558	  Otherwise, you should say N.
1559
1560config AMD_NUMA
1561	def_bool y
1562	prompt "Old style AMD Opteron NUMA detection"
1563	depends on X86_64 && NUMA && PCI
1564	help
1565	  Enable AMD NUMA node topology detection.  You should say Y here if
1566	  you have a multi processor AMD system. This uses an old method to
1567	  read the NUMA configuration directly from the builtin Northbridge
1568	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1569	  which also takes priority if both are compiled in.
1570
1571config X86_64_ACPI_NUMA
1572	def_bool y
1573	prompt "ACPI NUMA detection"
1574	depends on X86_64 && NUMA && ACPI && PCI
1575	select ACPI_NUMA
1576	help
1577	  Enable ACPI SRAT based node topology detection.
1578
1579config NUMA_EMU
1580	bool "NUMA emulation"
1581	depends on NUMA
1582	help
1583	  Enable NUMA emulation. A flat machine will be split
1584	  into virtual nodes when booted with "numa=fake=N", where N is the
1585	  number of nodes. This is only useful for debugging.
1586
1587config NODES_SHIFT
1588	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1589	range 1 10
1590	default "10" if MAXSMP
1591	default "6" if X86_64
1592	default "3"
1593	depends on NUMA
1594	help
1595	  Specify the maximum number of NUMA Nodes available on the target
1596	  system.  Increases memory reserved to accommodate various tables.
1597
1598config ARCH_FLATMEM_ENABLE
1599	def_bool y
1600	depends on X86_32 && !NUMA
1601
1602config ARCH_SPARSEMEM_ENABLE
1603	def_bool y
1604	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1605	select SPARSEMEM_STATIC if X86_32
1606	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1607
1608config ARCH_SPARSEMEM_DEFAULT
1609	def_bool X86_64 || (NUMA && X86_32)
1610
1611config ARCH_SELECT_MEMORY_MODEL
1612	def_bool y
1613	depends on ARCH_SPARSEMEM_ENABLE
1614
1615config ARCH_MEMORY_PROBE
1616	bool "Enable sysfs memory/probe interface"
1617	depends on X86_64 && MEMORY_HOTPLUG
1618	help
1619	  This option enables a sysfs memory/probe interface for testing.
1620	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1621	  If you are unsure how to answer this question, answer N.
1622
1623config ARCH_PROC_KCORE_TEXT
1624	def_bool y
1625	depends on X86_64 && PROC_KCORE
1626
1627config ILLEGAL_POINTER_VALUE
1628	hex
1629	default 0 if X86_32
1630	default 0xdead000000000000 if X86_64
1631
1632config X86_PMEM_LEGACY_DEVICE
1633	bool
1634
1635config X86_PMEM_LEGACY
1636	tristate "Support non-standard NVDIMMs and ADR protected memory"
1637	depends on PHYS_ADDR_T_64BIT
1638	depends on BLK_DEV
1639	select X86_PMEM_LEGACY_DEVICE
1640	select NUMA_KEEP_MEMINFO if NUMA
1641	select LIBNVDIMM
1642	help
1643	  Treat memory marked using the non-standard e820 type of 12 as used
1644	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1645	  The kernel will offer these regions to the 'pmem' driver so
1646	  they can be used for persistent storage.
1647
1648	  Say Y if unsure.
1649
1650config HIGHPTE
1651	bool "Allocate 3rd-level pagetables from highmem"
1652	depends on HIGHMEM
1653	help
1654	  The VM uses one page table entry for each page of physical memory.
1655	  For systems with a lot of RAM, this can be wasteful of precious
1656	  low memory.  Setting this option will put user-space page table
1657	  entries in high memory.
1658
1659config X86_CHECK_BIOS_CORRUPTION
1660	bool "Check for low memory corruption"
1661	help
1662	  Periodically check for memory corruption in low memory, which
1663	  is suspected to be caused by BIOS.  Even when enabled in the
1664	  configuration, it is disabled at runtime.  Enable it by
1665	  setting "memory_corruption_check=1" on the kernel command
1666	  line.  By default it scans the low 64k of memory every 60
1667	  seconds; see the memory_corruption_check_size and
1668	  memory_corruption_check_period parameters in
1669	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1670
1671	  When enabled with the default parameters, this option has
1672	  almost no overhead, as it reserves a relatively small amount
1673	  of memory and scans it infrequently.  It both detects corruption
1674	  and prevents it from affecting the running system.
1675
1676	  It is, however, intended as a diagnostic tool; if repeatable
1677	  BIOS-originated corruption always affects the same memory,
1678	  you can use memmap= to prevent the kernel from using that
1679	  memory.
1680
1681config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1682	bool "Set the default setting of memory_corruption_check"
1683	depends on X86_CHECK_BIOS_CORRUPTION
1684	default y
1685	help
1686	  Set whether the default state of memory_corruption_check is
1687	  on or off.
1688
1689config MATH_EMULATION
1690	bool
1691	depends on MODIFY_LDT_SYSCALL
1692	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1693	help
1694	  Linux can emulate a math coprocessor (used for floating point
1695	  operations) if you don't have one. 486DX and Pentium processors have
1696	  a math coprocessor built in, 486SX and 386 do not, unless you added
1697	  a 487DX or 387, respectively. (The messages during boot time can
1698	  give you some hints here ["man dmesg"].) Everyone needs either a
1699	  coprocessor or this emulation.
1700
1701	  If you don't have a math coprocessor, you need to say Y here; if you
1702	  say Y here even though you have a coprocessor, the coprocessor will
1703	  be used nevertheless. (This behavior can be changed with the kernel
1704	  command line option "no387", which comes handy if your coprocessor
1705	  is broken. Try "man bootparam" or see the documentation of your boot
1706	  loader (lilo or loadlin) about how to pass options to the kernel at
1707	  boot time.) This means that it is a good idea to say Y here if you
1708	  intend to use this kernel on different machines.
1709
1710	  More information about the internals of the Linux math coprocessor
1711	  emulation can be found in <file:arch/x86/math-emu/README>.
1712
1713	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1714	  kernel, it won't hurt.
1715
1716config MTRR
1717	def_bool y
1718	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1719	help
1720	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1721	  the Memory Type Range Registers (MTRRs) may be used to control
1722	  processor access to memory ranges. This is most useful if you have
1723	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1724	  allows bus write transfers to be combined into a larger transfer
1725	  before bursting over the PCI/AGP bus. This can increase performance
1726	  of image write operations 2.5 times or more. Saying Y here creates a
1727	  /proc/mtrr file which may be used to manipulate your processor's
1728	  MTRRs. Typically the X server should use this.
1729
1730	  This code has a reasonably generic interface so that similar
1731	  control registers on other processors can be easily supported
1732	  as well:
1733
1734	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1735	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1736	  these, the ARRs are used to emulate the MTRRs.
1737	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1738	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1739	  write-combining. All of these processors are supported by this code
1740	  and it makes sense to say Y here if you have one of them.
1741
1742	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1743	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1744	  can lead to all sorts of problems, so it's good to say Y here.
1745
1746	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1747	  just add about 9 KB to your kernel.
1748
1749	  See <file:Documentation/x86/mtrr.rst> for more information.
1750
1751config MTRR_SANITIZER
1752	def_bool y
1753	prompt "MTRR cleanup support"
1754	depends on MTRR
1755	help
1756	  Convert MTRR layout from continuous to discrete, so X drivers can
1757	  add writeback entries.
1758
1759	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1760	  The largest mtrr entry size for a continuous block can be set with
1761	  mtrr_chunk_size.
1762
1763	  If unsure, say Y.
1764
1765config MTRR_SANITIZER_ENABLE_DEFAULT
1766	int "MTRR cleanup enable value (0-1)"
1767	range 0 1
1768	default "0"
1769	depends on MTRR_SANITIZER
1770	help
1771	  Enable mtrr cleanup default value
1772
1773config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1774	int "MTRR cleanup spare reg num (0-7)"
1775	range 0 7
1776	default "1"
1777	depends on MTRR_SANITIZER
1778	help
1779	  mtrr cleanup spare entries default, it can be changed via
1780	  mtrr_spare_reg_nr=N on the kernel command line.
1781
1782config X86_PAT
1783	def_bool y
1784	prompt "x86 PAT support" if EXPERT
1785	depends on MTRR
1786	help
1787	  Use PAT attributes to setup page level cache control.
1788
1789	  PATs are the modern equivalents of MTRRs and are much more
1790	  flexible than MTRRs.
1791
1792	  Say N here if you see bootup problems (boot crash, boot hang,
1793	  spontaneous reboots) or a non-working video driver.
1794
1795	  If unsure, say Y.
1796
1797config ARCH_USES_PG_UNCACHED
1798	def_bool y
1799	depends on X86_PAT
1800
1801config ARCH_RANDOM
1802	def_bool y
1803	prompt "x86 architectural random number generator" if EXPERT
1804	help
1805	  Enable the x86 architectural RDRAND instruction
1806	  (Intel Bull Mountain technology) to generate random numbers.
1807	  If supported, this is a high bandwidth, cryptographically
1808	  secure hardware random number generator.
1809
1810config X86_SMAP
1811	def_bool y
1812	prompt "Supervisor Mode Access Prevention" if EXPERT
1813	help
1814	  Supervisor Mode Access Prevention (SMAP) is a security
1815	  feature in newer Intel processors.  There is a small
1816	  performance cost if this enabled and turned on; there is
1817	  also a small increase in the kernel size if this is enabled.
1818
1819	  If unsure, say Y.
1820
1821config X86_UMIP
1822	def_bool y
1823	prompt "User Mode Instruction Prevention" if EXPERT
1824	help
1825	  User Mode Instruction Prevention (UMIP) is a security feature in
1826	  some x86 processors. If enabled, a general protection fault is
1827	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1828	  executed in user mode. These instructions unnecessarily expose
1829	  information about the hardware state.
1830
1831	  The vast majority of applications do not use these instructions.
1832	  For the very few that do, software emulation is provided in
1833	  specific cases in protected and virtual-8086 modes. Emulated
1834	  results are dummy.
1835
1836config X86_INTEL_MEMORY_PROTECTION_KEYS
1837	prompt "Memory Protection Keys"
1838	def_bool y
1839	# Note: only available in 64-bit mode
1840	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1841	select ARCH_USES_HIGH_VMA_FLAGS
1842	select ARCH_HAS_PKEYS
1843	help
1844	  Memory Protection Keys provides a mechanism for enforcing
1845	  page-based protections, but without requiring modification of the
1846	  page tables when an application changes protection domains.
1847
1848	  For details, see Documentation/core-api/protection-keys.rst
1849
1850	  If unsure, say y.
1851
1852choice
1853	prompt "TSX enable mode"
1854	depends on CPU_SUP_INTEL
1855	default X86_INTEL_TSX_MODE_OFF
1856	help
1857	  Intel's TSX (Transactional Synchronization Extensions) feature
1858	  allows to optimize locking protocols through lock elision which
1859	  can lead to a noticeable performance boost.
1860
1861	  On the other hand it has been shown that TSX can be exploited
1862	  to form side channel attacks (e.g. TAA) and chances are there
1863	  will be more of those attacks discovered in the future.
1864
1865	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1866	  might override this decision by tsx=on the command line parameter.
1867	  Even with TSX enabled, the kernel will attempt to enable the best
1868	  possible TAA mitigation setting depending on the microcode available
1869	  for the particular machine.
1870
1871	  This option allows to set the default tsx mode between tsx=on, =off
1872	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1873	  details.
1874
1875	  Say off if not sure, auto if TSX is in use but it should be used on safe
1876	  platforms or on if TSX is in use and the security aspect of tsx is not
1877	  relevant.
1878
1879config X86_INTEL_TSX_MODE_OFF
1880	bool "off"
1881	help
1882	  TSX is disabled if possible - equals to tsx=off command line parameter.
1883
1884config X86_INTEL_TSX_MODE_ON
1885	bool "on"
1886	help
1887	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1888	  line parameter.
1889
1890config X86_INTEL_TSX_MODE_AUTO
1891	bool "auto"
1892	help
1893	  TSX is enabled on TSX capable HW that is believed to be safe against
1894	  side channel attacks- equals the tsx=auto command line parameter.
1895endchoice
1896
1897config X86_SGX
1898	bool "Software Guard eXtensions (SGX)"
1899	depends on X86_64 && CPU_SUP_INTEL
1900	depends on CRYPTO=y
1901	depends on CRYPTO_SHA256=y
1902	select SRCU
1903	select MMU_NOTIFIER
1904	select NUMA_KEEP_MEMINFO if NUMA
1905	help
1906	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1907	  that can be used by applications to set aside private regions of code
1908	  and data, referred to as enclaves. An enclave's private memory can
1909	  only be accessed by code running within the enclave. Accesses from
1910	  outside the enclave, including other enclaves, are disallowed by
1911	  hardware.
1912
1913	  If unsure, say N.
1914
1915config EFI
1916	bool "EFI runtime service support"
1917	depends on ACPI
1918	select UCS2_STRING
1919	select EFI_RUNTIME_WRAPPERS
1920	help
1921	  This enables the kernel to use EFI runtime services that are
1922	  available (such as the EFI variable services).
1923
1924	  This option is only useful on systems that have EFI firmware.
1925	  In addition, you should use the latest ELILO loader available
1926	  at <http://elilo.sourceforge.net> in order to take advantage
1927	  of EFI runtime services. However, even with this option, the
1928	  resultant kernel should continue to boot on existing non-EFI
1929	  platforms.
1930
1931config EFI_STUB
1932	bool "EFI stub support"
1933	depends on EFI && !X86_USE_3DNOW
1934	depends on $(cc-option,-mabi=ms) || X86_32
1935	select RELOCATABLE
1936	help
1937	  This kernel feature allows a bzImage to be loaded directly
1938	  by EFI firmware without the use of a bootloader.
1939
1940	  See Documentation/admin-guide/efi-stub.rst for more information.
1941
1942config EFI_MIXED
1943	bool "EFI mixed-mode support"
1944	depends on EFI_STUB && X86_64
1945	help
1946	   Enabling this feature allows a 64-bit kernel to be booted
1947	   on a 32-bit firmware, provided that your CPU supports 64-bit
1948	   mode.
1949
1950	   Note that it is not possible to boot a mixed-mode enabled
1951	   kernel via the EFI boot stub - a bootloader that supports
1952	   the EFI handover protocol must be used.
1953
1954	   If unsure, say N.
1955
1956source "kernel/Kconfig.hz"
1957
1958config KEXEC
1959	bool "kexec system call"
1960	select KEXEC_CORE
1961	help
1962	  kexec is a system call that implements the ability to shutdown your
1963	  current kernel, and to start another kernel.  It is like a reboot
1964	  but it is independent of the system firmware.   And like a reboot
1965	  you can start any kernel with it, not just Linux.
1966
1967	  The name comes from the similarity to the exec system call.
1968
1969	  It is an ongoing process to be certain the hardware in a machine
1970	  is properly shutdown, so do not be surprised if this code does not
1971	  initially work for you.  As of this writing the exact hardware
1972	  interface is strongly in flux, so no good recommendation can be
1973	  made.
1974
1975config KEXEC_FILE
1976	bool "kexec file based system call"
1977	select KEXEC_CORE
1978	select BUILD_BIN2C
1979	depends on X86_64
1980	depends on CRYPTO=y
1981	depends on CRYPTO_SHA256=y
1982	help
1983	  This is new version of kexec system call. This system call is
1984	  file based and takes file descriptors as system call argument
1985	  for kernel and initramfs as opposed to list of segments as
1986	  accepted by previous system call.
1987
1988config ARCH_HAS_KEXEC_PURGATORY
1989	def_bool KEXEC_FILE
1990
1991config KEXEC_SIG
1992	bool "Verify kernel signature during kexec_file_load() syscall"
1993	depends on KEXEC_FILE
1994	help
1995
1996	  This option makes the kexec_file_load() syscall check for a valid
1997	  signature of the kernel image.  The image can still be loaded without
1998	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
1999	  there's a signature that we can check, then it must be valid.
2000
2001	  In addition to this option, you need to enable signature
2002	  verification for the corresponding kernel image type being
2003	  loaded in order for this to work.
2004
2005config KEXEC_SIG_FORCE
2006	bool "Require a valid signature in kexec_file_load() syscall"
2007	depends on KEXEC_SIG
2008	help
2009	  This option makes kernel signature verification mandatory for
2010	  the kexec_file_load() syscall.
2011
2012config KEXEC_BZIMAGE_VERIFY_SIG
2013	bool "Enable bzImage signature verification support"
2014	depends on KEXEC_SIG
2015	depends on SIGNED_PE_FILE_VERIFICATION
2016	select SYSTEM_TRUSTED_KEYRING
2017	help
2018	  Enable bzImage signature verification support.
2019
2020config CRASH_DUMP
2021	bool "kernel crash dumps"
2022	depends on X86_64 || (X86_32 && HIGHMEM)
2023	help
2024	  Generate crash dump after being started by kexec.
2025	  This should be normally only set in special crash dump kernels
2026	  which are loaded in the main kernel with kexec-tools into
2027	  a specially reserved region and then later executed after
2028	  a crash by kdump/kexec. The crash dump kernel must be compiled
2029	  to a memory address not used by the main kernel or BIOS using
2030	  PHYSICAL_START, or it must be built as a relocatable image
2031	  (CONFIG_RELOCATABLE=y).
2032	  For more details see Documentation/admin-guide/kdump/kdump.rst
2033
2034config KEXEC_JUMP
2035	bool "kexec jump"
2036	depends on KEXEC && HIBERNATION
2037	help
2038	  Jump between original kernel and kexeced kernel and invoke
2039	  code in physical address mode via KEXEC
2040
2041config PHYSICAL_START
2042	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2043	default "0x1000000"
2044	help
2045	  This gives the physical address where the kernel is loaded.
2046
2047	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2048	  bzImage will decompress itself to above physical address and
2049	  run from there. Otherwise, bzImage will run from the address where
2050	  it has been loaded by the boot loader and will ignore above physical
2051	  address.
2052
2053	  In normal kdump cases one does not have to set/change this option
2054	  as now bzImage can be compiled as a completely relocatable image
2055	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2056	  address. This option is mainly useful for the folks who don't want
2057	  to use a bzImage for capturing the crash dump and want to use a
2058	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2059	  to be specifically compiled to run from a specific memory area
2060	  (normally a reserved region) and this option comes handy.
2061
2062	  So if you are using bzImage for capturing the crash dump,
2063	  leave the value here unchanged to 0x1000000 and set
2064	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2065	  for capturing the crash dump change this value to start of
2066	  the reserved region.  In other words, it can be set based on
2067	  the "X" value as specified in the "crashkernel=YM@XM"
2068	  command line boot parameter passed to the panic-ed
2069	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2070	  for more details about crash dumps.
2071
2072	  Usage of bzImage for capturing the crash dump is recommended as
2073	  one does not have to build two kernels. Same kernel can be used
2074	  as production kernel and capture kernel. Above option should have
2075	  gone away after relocatable bzImage support is introduced. But it
2076	  is present because there are users out there who continue to use
2077	  vmlinux for dump capture. This option should go away down the
2078	  line.
2079
2080	  Don't change this unless you know what you are doing.
2081
2082config RELOCATABLE
2083	bool "Build a relocatable kernel"
2084	default y
2085	help
2086	  This builds a kernel image that retains relocation information
2087	  so it can be loaded someplace besides the default 1MB.
2088	  The relocations tend to make the kernel binary about 10% larger,
2089	  but are discarded at runtime.
2090
2091	  One use is for the kexec on panic case where the recovery kernel
2092	  must live at a different physical address than the primary
2093	  kernel.
2094
2095	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2096	  it has been loaded at and the compile time physical address
2097	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2098
2099config RANDOMIZE_BASE
2100	bool "Randomize the address of the kernel image (KASLR)"
2101	depends on RELOCATABLE
2102	default y
2103	help
2104	  In support of Kernel Address Space Layout Randomization (KASLR),
2105	  this randomizes the physical address at which the kernel image
2106	  is decompressed and the virtual address where the kernel
2107	  image is mapped, as a security feature that deters exploit
2108	  attempts relying on knowledge of the location of kernel
2109	  code internals.
2110
2111	  On 64-bit, the kernel physical and virtual addresses are
2112	  randomized separately. The physical address will be anywhere
2113	  between 16MB and the top of physical memory (up to 64TB). The
2114	  virtual address will be randomized from 16MB up to 1GB (9 bits
2115	  of entropy). Note that this also reduces the memory space
2116	  available to kernel modules from 1.5GB to 1GB.
2117
2118	  On 32-bit, the kernel physical and virtual addresses are
2119	  randomized together. They will be randomized from 16MB up to
2120	  512MB (8 bits of entropy).
2121
2122	  Entropy is generated using the RDRAND instruction if it is
2123	  supported. If RDTSC is supported, its value is mixed into
2124	  the entropy pool as well. If neither RDRAND nor RDTSC are
2125	  supported, then entropy is read from the i8254 timer. The
2126	  usable entropy is limited by the kernel being built using
2127	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2128	  minimum of 2MB. As a result, only 10 bits of entropy are
2129	  theoretically possible, but the implementations are further
2130	  limited due to memory layouts.
2131
2132	  If unsure, say Y.
2133
2134# Relocation on x86 needs some additional build support
2135config X86_NEED_RELOCS
2136	def_bool y
2137	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2138
2139config PHYSICAL_ALIGN
2140	hex "Alignment value to which kernel should be aligned"
2141	default "0x200000"
2142	range 0x2000 0x1000000 if X86_32
2143	range 0x200000 0x1000000 if X86_64
2144	help
2145	  This value puts the alignment restrictions on physical address
2146	  where kernel is loaded and run from. Kernel is compiled for an
2147	  address which meets above alignment restriction.
2148
2149	  If bootloader loads the kernel at a non-aligned address and
2150	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2151	  address aligned to above value and run from there.
2152
2153	  If bootloader loads the kernel at a non-aligned address and
2154	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2155	  load address and decompress itself to the address it has been
2156	  compiled for and run from there. The address for which kernel is
2157	  compiled already meets above alignment restrictions. Hence the
2158	  end result is that kernel runs from a physical address meeting
2159	  above alignment restrictions.
2160
2161	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2162	  this value must be a multiple of 0x200000.
2163
2164	  Don't change this unless you know what you are doing.
2165
2166config DYNAMIC_MEMORY_LAYOUT
2167	bool
2168	help
2169	  This option makes base addresses of vmalloc and vmemmap as well as
2170	  __PAGE_OFFSET movable during boot.
2171
2172config RANDOMIZE_MEMORY
2173	bool "Randomize the kernel memory sections"
2174	depends on X86_64
2175	depends on RANDOMIZE_BASE
2176	select DYNAMIC_MEMORY_LAYOUT
2177	default RANDOMIZE_BASE
2178	help
2179	   Randomizes the base virtual address of kernel memory sections
2180	   (physical memory mapping, vmalloc & vmemmap). This security feature
2181	   makes exploits relying on predictable memory locations less reliable.
2182
2183	   The order of allocations remains unchanged. Entropy is generated in
2184	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2185	   configuration have in average 30,000 different possible virtual
2186	   addresses for each memory section.
2187
2188	   If unsure, say Y.
2189
2190config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2191	hex "Physical memory mapping padding" if EXPERT
2192	depends on RANDOMIZE_MEMORY
2193	default "0xa" if MEMORY_HOTPLUG
2194	default "0x0"
2195	range 0x1 0x40 if MEMORY_HOTPLUG
2196	range 0x0 0x40
2197	help
2198	   Define the padding in terabytes added to the existing physical
2199	   memory size during kernel memory randomization. It is useful
2200	   for memory hotplug support but reduces the entropy available for
2201	   address randomization.
2202
2203	   If unsure, leave at the default value.
2204
2205config HOTPLUG_CPU
2206	def_bool y
2207	depends on SMP
2208
2209config BOOTPARAM_HOTPLUG_CPU0
2210	bool "Set default setting of cpu0_hotpluggable"
2211	depends on HOTPLUG_CPU
2212	help
2213	  Set whether default state of cpu0_hotpluggable is on or off.
2214
2215	  Say Y here to enable CPU0 hotplug by default. If this switch
2216	  is turned on, there is no need to give cpu0_hotplug kernel
2217	  parameter and the CPU0 hotplug feature is enabled by default.
2218
2219	  Please note: there are two known CPU0 dependencies if you want
2220	  to enable the CPU0 hotplug feature either by this switch or by
2221	  cpu0_hotplug kernel parameter.
2222
2223	  First, resume from hibernate or suspend always starts from CPU0.
2224	  So hibernate and suspend are prevented if CPU0 is offline.
2225
2226	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2227	  offline if any interrupt can not migrate out of CPU0. There may
2228	  be other CPU0 dependencies.
2229
2230	  Please make sure the dependencies are under your control before
2231	  you enable this feature.
2232
2233	  Say N if you don't want to enable CPU0 hotplug feature by default.
2234	  You still can enable the CPU0 hotplug feature at boot by kernel
2235	  parameter cpu0_hotplug.
2236
2237config DEBUG_HOTPLUG_CPU0
2238	def_bool n
2239	prompt "Debug CPU0 hotplug"
2240	depends on HOTPLUG_CPU
2241	help
2242	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2243	  soon as possible and boots up userspace with CPU0 offlined. User
2244	  can online CPU0 back after boot time.
2245
2246	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2247	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2248	  compilation or giving cpu0_hotplug kernel parameter at boot.
2249
2250	  If unsure, say N.
2251
2252config COMPAT_VDSO
2253	def_bool n
2254	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2255	depends on COMPAT_32
2256	help
2257	  Certain buggy versions of glibc will crash if they are
2258	  presented with a 32-bit vDSO that is not mapped at the address
2259	  indicated in its segment table.
2260
2261	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2262	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2263	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2264	  the only released version with the bug, but OpenSUSE 9
2265	  contains a buggy "glibc 2.3.2".
2266
2267	  The symptom of the bug is that everything crashes on startup, saying:
2268	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2269
2270	  Saying Y here changes the default value of the vdso32 boot
2271	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2272	  This works around the glibc bug but hurts performance.
2273
2274	  If unsure, say N: if you are compiling your own kernel, you
2275	  are unlikely to be using a buggy version of glibc.
2276
2277choice
2278	prompt "vsyscall table for legacy applications"
2279	depends on X86_64
2280	default LEGACY_VSYSCALL_XONLY
2281	help
2282	  Legacy user code that does not know how to find the vDSO expects
2283	  to be able to issue three syscalls by calling fixed addresses in
2284	  kernel space. Since this location is not randomized with ASLR,
2285	  it can be used to assist security vulnerability exploitation.
2286
2287	  This setting can be changed at boot time via the kernel command
2288	  line parameter vsyscall=[emulate|xonly|none].
2289
2290	  On a system with recent enough glibc (2.14 or newer) and no
2291	  static binaries, you can say None without a performance penalty
2292	  to improve security.
2293
2294	  If unsure, select "Emulate execution only".
2295
2296	config LEGACY_VSYSCALL_EMULATE
2297		bool "Full emulation"
2298		help
2299		  The kernel traps and emulates calls into the fixed vsyscall
2300		  address mapping. This makes the mapping non-executable, but
2301		  it still contains readable known contents, which could be
2302		  used in certain rare security vulnerability exploits. This
2303		  configuration is recommended when using legacy userspace
2304		  that still uses vsyscalls along with legacy binary
2305		  instrumentation tools that require code to be readable.
2306
2307		  An example of this type of legacy userspace is running
2308		  Pin on an old binary that still uses vsyscalls.
2309
2310	config LEGACY_VSYSCALL_XONLY
2311		bool "Emulate execution only"
2312		help
2313		  The kernel traps and emulates calls into the fixed vsyscall
2314		  address mapping and does not allow reads.  This
2315		  configuration is recommended when userspace might use the
2316		  legacy vsyscall area but support for legacy binary
2317		  instrumentation of legacy code is not needed.  It mitigates
2318		  certain uses of the vsyscall area as an ASLR-bypassing
2319		  buffer.
2320
2321	config LEGACY_VSYSCALL_NONE
2322		bool "None"
2323		help
2324		  There will be no vsyscall mapping at all. This will
2325		  eliminate any risk of ASLR bypass due to the vsyscall
2326		  fixed address mapping. Attempts to use the vsyscalls
2327		  will be reported to dmesg, so that either old or
2328		  malicious userspace programs can be identified.
2329
2330endchoice
2331
2332config CMDLINE_BOOL
2333	bool "Built-in kernel command line"
2334	help
2335	  Allow for specifying boot arguments to the kernel at
2336	  build time.  On some systems (e.g. embedded ones), it is
2337	  necessary or convenient to provide some or all of the
2338	  kernel boot arguments with the kernel itself (that is,
2339	  to not rely on the boot loader to provide them.)
2340
2341	  To compile command line arguments into the kernel,
2342	  set this option to 'Y', then fill in the
2343	  boot arguments in CONFIG_CMDLINE.
2344
2345	  Systems with fully functional boot loaders (i.e. non-embedded)
2346	  should leave this option set to 'N'.
2347
2348config CMDLINE
2349	string "Built-in kernel command string"
2350	depends on CMDLINE_BOOL
2351	default ""
2352	help
2353	  Enter arguments here that should be compiled into the kernel
2354	  image and used at boot time.  If the boot loader provides a
2355	  command line at boot time, it is appended to this string to
2356	  form the full kernel command line, when the system boots.
2357
2358	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2359	  change this behavior.
2360
2361	  In most cases, the command line (whether built-in or provided
2362	  by the boot loader) should specify the device for the root
2363	  file system.
2364
2365config CMDLINE_OVERRIDE
2366	bool "Built-in command line overrides boot loader arguments"
2367	depends on CMDLINE_BOOL && CMDLINE != ""
2368	help
2369	  Set this option to 'Y' to have the kernel ignore the boot loader
2370	  command line, and use ONLY the built-in command line.
2371
2372	  This is used to work around broken boot loaders.  This should
2373	  be set to 'N' under normal conditions.
2374
2375config MODIFY_LDT_SYSCALL
2376	bool "Enable the LDT (local descriptor table)" if EXPERT
2377	default y
2378	help
2379	  Linux can allow user programs to install a per-process x86
2380	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2381	  call.  This is required to run 16-bit or segmented code such as
2382	  DOSEMU or some Wine programs.  It is also used by some very old
2383	  threading libraries.
2384
2385	  Enabling this feature adds a small amount of overhead to
2386	  context switches and increases the low-level kernel attack
2387	  surface.  Disabling it removes the modify_ldt(2) system call.
2388
2389	  Saying 'N' here may make sense for embedded or server kernels.
2390
2391source "kernel/livepatch/Kconfig"
2392
2393endmenu
2394
2395config ARCH_HAS_ADD_PAGES
2396	def_bool y
2397	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2398
2399config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2400	def_bool y
2401
2402config USE_PERCPU_NUMA_NODE_ID
2403	def_bool y
2404	depends on NUMA
2405
2406menu "Power management and ACPI options"
2407
2408config ARCH_HIBERNATION_HEADER
2409	def_bool y
2410	depends on HIBERNATION
2411
2412source "kernel/power/Kconfig"
2413
2414source "drivers/acpi/Kconfig"
2415
2416config X86_APM_BOOT
2417	def_bool y
2418	depends on APM
2419
2420menuconfig APM
2421	tristate "APM (Advanced Power Management) BIOS support"
2422	depends on X86_32 && PM_SLEEP
2423	help
2424	  APM is a BIOS specification for saving power using several different
2425	  techniques. This is mostly useful for battery powered laptops with
2426	  APM compliant BIOSes. If you say Y here, the system time will be
2427	  reset after a RESUME operation, the /proc/apm device will provide
2428	  battery status information, and user-space programs will receive
2429	  notification of APM "events" (e.g. battery status change).
2430
2431	  If you select "Y" here, you can disable actual use of the APM
2432	  BIOS by passing the "apm=off" option to the kernel at boot time.
2433
2434	  Note that the APM support is almost completely disabled for
2435	  machines with more than one CPU.
2436
2437	  In order to use APM, you will need supporting software. For location
2438	  and more information, read <file:Documentation/power/apm-acpi.rst>
2439	  and the Battery Powered Linux mini-HOWTO, available from
2440	  <http://www.tldp.org/docs.html#howto>.
2441
2442	  This driver does not spin down disk drives (see the hdparm(8)
2443	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2444	  VESA-compliant "green" monitors.
2445
2446	  This driver does not support the TI 4000M TravelMate and the ACER
2447	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2448	  desktop machines also don't have compliant BIOSes, and this driver
2449	  may cause those machines to panic during the boot phase.
2450
2451	  Generally, if you don't have a battery in your machine, there isn't
2452	  much point in using this driver and you should say N. If you get
2453	  random kernel OOPSes or reboots that don't seem to be related to
2454	  anything, try disabling/enabling this option (or disabling/enabling
2455	  APM in your BIOS).
2456
2457	  Some other things you should try when experiencing seemingly random,
2458	  "weird" problems:
2459
2460	  1) make sure that you have enough swap space and that it is
2461	  enabled.
2462	  2) pass the "no-hlt" option to the kernel
2463	  3) switch on floating point emulation in the kernel and pass
2464	  the "no387" option to the kernel
2465	  4) pass the "floppy=nodma" option to the kernel
2466	  5) pass the "mem=4M" option to the kernel (thereby disabling
2467	  all but the first 4 MB of RAM)
2468	  6) make sure that the CPU is not over clocked.
2469	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2470	  8) disable the cache from your BIOS settings
2471	  9) install a fan for the video card or exchange video RAM
2472	  10) install a better fan for the CPU
2473	  11) exchange RAM chips
2474	  12) exchange the motherboard.
2475
2476	  To compile this driver as a module, choose M here: the
2477	  module will be called apm.
2478
2479if APM
2480
2481config APM_IGNORE_USER_SUSPEND
2482	bool "Ignore USER SUSPEND"
2483	help
2484	  This option will ignore USER SUSPEND requests. On machines with a
2485	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2486	  series notebooks, it is necessary to say Y because of a BIOS bug.
2487
2488config APM_DO_ENABLE
2489	bool "Enable PM at boot time"
2490	help
2491	  Enable APM features at boot time. From page 36 of the APM BIOS
2492	  specification: "When disabled, the APM BIOS does not automatically
2493	  power manage devices, enter the Standby State, enter the Suspend
2494	  State, or take power saving steps in response to CPU Idle calls."
2495	  This driver will make CPU Idle calls when Linux is idle (unless this
2496	  feature is turned off -- see "Do CPU IDLE calls", below). This
2497	  should always save battery power, but more complicated APM features
2498	  will be dependent on your BIOS implementation. You may need to turn
2499	  this option off if your computer hangs at boot time when using APM
2500	  support, or if it beeps continuously instead of suspending. Turn
2501	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2502	  T400CDT. This is off by default since most machines do fine without
2503	  this feature.
2504
2505config APM_CPU_IDLE
2506	depends on CPU_IDLE
2507	bool "Make CPU Idle calls when idle"
2508	help
2509	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2510	  On some machines, this can activate improved power savings, such as
2511	  a slowed CPU clock rate, when the machine is idle. These idle calls
2512	  are made after the idle loop has run for some length of time (e.g.,
2513	  333 mS). On some machines, this will cause a hang at boot time or
2514	  whenever the CPU becomes idle. (On machines with more than one CPU,
2515	  this option does nothing.)
2516
2517config APM_DISPLAY_BLANK
2518	bool "Enable console blanking using APM"
2519	help
2520	  Enable console blanking using the APM. Some laptops can use this to
2521	  turn off the LCD backlight when the screen blanker of the Linux
2522	  virtual console blanks the screen. Note that this is only used by
2523	  the virtual console screen blanker, and won't turn off the backlight
2524	  when using the X Window system. This also doesn't have anything to
2525	  do with your VESA-compliant power-saving monitor. Further, this
2526	  option doesn't work for all laptops -- it might not turn off your
2527	  backlight at all, or it might print a lot of errors to the console,
2528	  especially if you are using gpm.
2529
2530config APM_ALLOW_INTS
2531	bool "Allow interrupts during APM BIOS calls"
2532	help
2533	  Normally we disable external interrupts while we are making calls to
2534	  the APM BIOS as a measure to lessen the effects of a badly behaving
2535	  BIOS implementation.  The BIOS should reenable interrupts if it
2536	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2537	  many of the newer IBM Thinkpads.  If you experience hangs when you
2538	  suspend, try setting this to Y.  Otherwise, say N.
2539
2540endif # APM
2541
2542source "drivers/cpufreq/Kconfig"
2543
2544source "drivers/cpuidle/Kconfig"
2545
2546source "drivers/idle/Kconfig"
2547
2548endmenu
2549
2550
2551menu "Bus options (PCI etc.)"
2552
2553choice
2554	prompt "PCI access mode"
2555	depends on X86_32 && PCI
2556	default PCI_GOANY
2557	help
2558	  On PCI systems, the BIOS can be used to detect the PCI devices and
2559	  determine their configuration. However, some old PCI motherboards
2560	  have BIOS bugs and may crash if this is done. Also, some embedded
2561	  PCI-based systems don't have any BIOS at all. Linux can also try to
2562	  detect the PCI hardware directly without using the BIOS.
2563
2564	  With this option, you can specify how Linux should detect the
2565	  PCI devices. If you choose "BIOS", the BIOS will be used,
2566	  if you choose "Direct", the BIOS won't be used, and if you
2567	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2568	  If you choose "Any", the kernel will try MMCONFIG, then the
2569	  direct access method and falls back to the BIOS if that doesn't
2570	  work. If unsure, go with the default, which is "Any".
2571
2572config PCI_GOBIOS
2573	bool "BIOS"
2574
2575config PCI_GOMMCONFIG
2576	bool "MMConfig"
2577
2578config PCI_GODIRECT
2579	bool "Direct"
2580
2581config PCI_GOOLPC
2582	bool "OLPC XO-1"
2583	depends on OLPC
2584
2585config PCI_GOANY
2586	bool "Any"
2587
2588endchoice
2589
2590config PCI_BIOS
2591	def_bool y
2592	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2593
2594# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2595config PCI_DIRECT
2596	def_bool y
2597	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2598
2599config PCI_MMCONFIG
2600	bool "Support mmconfig PCI config space access" if X86_64
2601	default y
2602	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2603	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2604
2605config PCI_OLPC
2606	def_bool y
2607	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2608
2609config PCI_XEN
2610	def_bool y
2611	depends on PCI && XEN
2612
2613config MMCONF_FAM10H
2614	def_bool y
2615	depends on X86_64 && PCI_MMCONFIG && ACPI
2616
2617config PCI_CNB20LE_QUIRK
2618	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2619	depends on PCI
2620	help
2621	  Read the PCI windows out of the CNB20LE host bridge. This allows
2622	  PCI hotplug to work on systems with the CNB20LE chipset which do
2623	  not have ACPI.
2624
2625	  There's no public spec for this chipset, and this functionality
2626	  is known to be incomplete.
2627
2628	  You should say N unless you know you need this.
2629
2630config ISA_BUS
2631	bool "ISA bus support on modern systems" if EXPERT
2632	help
2633	  Expose ISA bus device drivers and options available for selection and
2634	  configuration. Enable this option if your target machine has an ISA
2635	  bus. ISA is an older system, displaced by PCI and newer bus
2636	  architectures -- if your target machine is modern, it probably does
2637	  not have an ISA bus.
2638
2639	  If unsure, say N.
2640
2641# x86_64 have no ISA slots, but can have ISA-style DMA.
2642config ISA_DMA_API
2643	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2644	default y
2645	help
2646	  Enables ISA-style DMA support for devices requiring such controllers.
2647	  If unsure, say Y.
2648
2649if X86_32
2650
2651config ISA
2652	bool "ISA support"
2653	help
2654	  Find out whether you have ISA slots on your motherboard.  ISA is the
2655	  name of a bus system, i.e. the way the CPU talks to the other stuff
2656	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2657	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2658	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2659
2660config SCx200
2661	tristate "NatSemi SCx200 support"
2662	help
2663	  This provides basic support for National Semiconductor's
2664	  (now AMD's) Geode processors.  The driver probes for the
2665	  PCI-IDs of several on-chip devices, so its a good dependency
2666	  for other scx200_* drivers.
2667
2668	  If compiled as a module, the driver is named scx200.
2669
2670config SCx200HR_TIMER
2671	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2672	depends on SCx200
2673	default y
2674	help
2675	  This driver provides a clocksource built upon the on-chip
2676	  27MHz high-resolution timer.  Its also a workaround for
2677	  NSC Geode SC-1100's buggy TSC, which loses time when the
2678	  processor goes idle (as is done by the scheduler).  The
2679	  other workaround is idle=poll boot option.
2680
2681config OLPC
2682	bool "One Laptop Per Child support"
2683	depends on !X86_PAE
2684	select GPIOLIB
2685	select OF
2686	select OF_PROMTREE
2687	select IRQ_DOMAIN
2688	select OLPC_EC
2689	help
2690	  Add support for detecting the unique features of the OLPC
2691	  XO hardware.
2692
2693config OLPC_XO1_PM
2694	bool "OLPC XO-1 Power Management"
2695	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2696	help
2697	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2698
2699config OLPC_XO1_RTC
2700	bool "OLPC XO-1 Real Time Clock"
2701	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2702	help
2703	  Add support for the XO-1 real time clock, which can be used as a
2704	  programmable wakeup source.
2705
2706config OLPC_XO1_SCI
2707	bool "OLPC XO-1 SCI extras"
2708	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2709	depends on INPUT=y
2710	select POWER_SUPPLY
2711	help
2712	  Add support for SCI-based features of the OLPC XO-1 laptop:
2713	   - EC-driven system wakeups
2714	   - Power button
2715	   - Ebook switch
2716	   - Lid switch
2717	   - AC adapter status updates
2718	   - Battery status updates
2719
2720config OLPC_XO15_SCI
2721	bool "OLPC XO-1.5 SCI extras"
2722	depends on OLPC && ACPI
2723	select POWER_SUPPLY
2724	help
2725	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2726	   - EC-driven system wakeups
2727	   - AC adapter status updates
2728	   - Battery status updates
2729
2730config ALIX
2731	bool "PCEngines ALIX System Support (LED setup)"
2732	select GPIOLIB
2733	help
2734	  This option enables system support for the PCEngines ALIX.
2735	  At present this just sets up LEDs for GPIO control on
2736	  ALIX2/3/6 boards.  However, other system specific setup should
2737	  get added here.
2738
2739	  Note: You must still enable the drivers for GPIO and LED support
2740	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2741
2742	  Note: You have to set alix.force=1 for boards with Award BIOS.
2743
2744config NET5501
2745	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2746	select GPIOLIB
2747	help
2748	  This option enables system support for the Soekris Engineering net5501.
2749
2750config GEOS
2751	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2752	select GPIOLIB
2753	depends on DMI
2754	help
2755	  This option enables system support for the Traverse Technologies GEOS.
2756
2757config TS5500
2758	bool "Technologic Systems TS-5500 platform support"
2759	depends on MELAN
2760	select CHECK_SIGNATURE
2761	select NEW_LEDS
2762	select LEDS_CLASS
2763	help
2764	  This option enables system support for the Technologic Systems TS-5500.
2765
2766endif # X86_32
2767
2768config AMD_NB
2769	def_bool y
2770	depends on CPU_SUP_AMD && PCI
2771
2772endmenu
2773
2774
2775menu "Binary Emulations"
2776
2777config IA32_EMULATION
2778	bool "IA32 Emulation"
2779	depends on X86_64
2780	select ARCH_WANT_OLD_COMPAT_IPC
2781	select BINFMT_ELF
2782	select COMPAT_OLD_SIGACTION
2783	help
2784	  Include code to run legacy 32-bit programs under a
2785	  64-bit kernel. You should likely turn this on, unless you're
2786	  100% sure that you don't have any 32-bit programs left.
2787
2788config IA32_AOUT
2789	tristate "IA32 a.out support"
2790	depends on IA32_EMULATION
2791	depends on BROKEN
2792	help
2793	  Support old a.out binaries in the 32bit emulation.
2794
2795config X86_X32
2796	bool "x32 ABI for 64-bit mode"
2797	depends on X86_64
2798	help
2799	  Include code to run binaries for the x32 native 32-bit ABI
2800	  for 64-bit processors.  An x32 process gets access to the
2801	  full 64-bit register file and wide data path while leaving
2802	  pointers at 32 bits for smaller memory footprint.
2803
2804	  You will need a recent binutils (2.22 or later) with
2805	  elf32_x86_64 support enabled to compile a kernel with this
2806	  option set.
2807
2808config COMPAT_32
2809	def_bool y
2810	depends on IA32_EMULATION || X86_32
2811	select HAVE_UID16
2812	select OLD_SIGSUSPEND3
2813
2814config COMPAT
2815	def_bool y
2816	depends on IA32_EMULATION || X86_X32
2817
2818if COMPAT
2819config COMPAT_FOR_U64_ALIGNMENT
2820	def_bool y
2821
2822config SYSVIPC_COMPAT
2823	def_bool y
2824	depends on SYSVIPC
2825endif
2826
2827endmenu
2828
2829
2830config HAVE_ATOMIC_IOMAP
2831	def_bool y
2832	depends on X86_32
2833
2834source "arch/x86/kvm/Kconfig"
2835
2836source "arch/x86/Kconfig.assembler"
2837