xref: /openbmc/linux/arch/x86/Kconfig (revision 474be445555ba8f2e776b4b6458c310bc215f76b)
1 # SPDX-License-Identifier: GPL-2.0
2 # Select 32 or 64 bit
3 config 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 
10 config 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 
24 config 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 
38 config 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 #
55 config 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_CORRECT_STACKTRACE_ON_KRETPROBE
65 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
66 	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
67 	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
69 	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
70 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71 	select ARCH_HAS_CACHE_LINE_SIZE
72 	select ARCH_HAS_CURRENT_STACK_POINTER
73 	select ARCH_HAS_DEBUG_VIRTUAL
74 	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
75 	select ARCH_HAS_DEVMEM_IS_ALLOWED
76 	select ARCH_HAS_EARLY_DEBUG		if KGDB
77 	select ARCH_HAS_ELF_RANDOMIZE
78 	select ARCH_HAS_FAST_MULTIPLIER
79 	select ARCH_HAS_FORTIFY_SOURCE
80 	select ARCH_HAS_GCOV_PROFILE_ALL
81 	select ARCH_HAS_KCOV			if X86_64
82 	select ARCH_HAS_MEM_ENCRYPT
83 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
84 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
85 	select ARCH_HAS_PMEM_API		if X86_64
86 	select ARCH_HAS_PTE_DEVMAP		if X86_64
87 	select ARCH_HAS_PTE_SPECIAL
88 	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
89 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
90 	select ARCH_HAS_COPY_MC			if X86_64
91 	select ARCH_HAS_SET_MEMORY
92 	select ARCH_HAS_SET_DIRECT_MAP
93 	select ARCH_HAS_STRICT_KERNEL_RWX
94 	select ARCH_HAS_STRICT_MODULE_RWX
95 	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
96 	select ARCH_HAS_SYSCALL_WRAPPER
97 	select ARCH_HAS_UBSAN_SANITIZE_ALL
98 	select ARCH_HAS_DEBUG_WX
99 	select ARCH_HAS_ZONE_DMA_SET if EXPERT
100 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
102 	select ARCH_MIGHT_HAVE_PC_PARPORT
103 	select ARCH_MIGHT_HAVE_PC_SERIO
104 	select ARCH_STACKWALK
105 	select ARCH_SUPPORTS_ACPI
106 	select ARCH_SUPPORTS_ATOMIC_RMW
107 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
108 	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
109 	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
110 	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
111 	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
112 	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
113 	select ARCH_SUPPORTS_LTO_CLANG
114 	select ARCH_SUPPORTS_LTO_CLANG_THIN
115 	select ARCH_USE_BUILTIN_BSWAP
116 	select ARCH_USE_MEMTEST
117 	select ARCH_USE_QUEUED_RWLOCKS
118 	select ARCH_USE_QUEUED_SPINLOCKS
119 	select ARCH_USE_SYM_ANNOTATIONS
120 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
121 	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
122 	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
123 	select ARCH_WANTS_NO_INSTR
124 	select ARCH_WANT_GENERAL_HUGETLB
125 	select ARCH_WANT_HUGE_PMD_SHARE
126 	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
127 	select ARCH_WANT_LD_ORPHAN_WARN
128 	select ARCH_WANTS_THP_SWAP		if X86_64
129 	select ARCH_HAS_PARANOID_L1D_FLUSH
130 	select BUILDTIME_TABLE_SORT
131 	select CLKEVT_I8253
132 	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
133 	select CLOCKSOURCE_WATCHDOG
134 	# Word-size accesses may read uninitialized data past the trailing \0
135 	# in strings and cause false KMSAN reports.
136 	select DCACHE_WORD_ACCESS		if !KMSAN
137 	select DYNAMIC_SIGFRAME
138 	select EDAC_ATOMIC_SCRUB
139 	select EDAC_SUPPORT
140 	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
141 	select GENERIC_CLOCKEVENTS_MIN_ADJUST
142 	select GENERIC_CMOS_UPDATE
143 	select GENERIC_CPU_AUTOPROBE
144 	select GENERIC_CPU_VULNERABILITIES
145 	select GENERIC_EARLY_IOREMAP
146 	select GENERIC_ENTRY
147 	select GENERIC_IOMAP
148 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
149 	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
150 	select GENERIC_IRQ_MIGRATION		if SMP
151 	select GENERIC_IRQ_PROBE
152 	select GENERIC_IRQ_RESERVATION_MODE
153 	select GENERIC_IRQ_SHOW
154 	select GENERIC_PENDING_IRQ		if SMP
155 	select GENERIC_PTDUMP
156 	select GENERIC_SMP_IDLE_THREAD
157 	select GENERIC_TIME_VSYSCALL
158 	select GENERIC_GETTIMEOFDAY
159 	select GENERIC_VDSO_TIME_NS
160 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
161 	select HARDIRQS_SW_RESEND
162 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
163 	select HAVE_ACPI_APEI			if ACPI
164 	select HAVE_ACPI_APEI_NMI		if ACPI
165 	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
166 	select HAVE_ARCH_AUDITSYSCALL
167 	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
168 	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
169 	select HAVE_ARCH_JUMP_LABEL
170 	select HAVE_ARCH_JUMP_LABEL_RELATIVE
171 	select HAVE_ARCH_KASAN			if X86_64
172 	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
173 	select HAVE_ARCH_KFENCE
174 	select HAVE_ARCH_KMSAN			if X86_64
175 	select HAVE_ARCH_KGDB
176 	select HAVE_ARCH_MMAP_RND_BITS		if MMU
177 	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
178 	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
179 	select HAVE_ARCH_PREL32_RELOCATIONS
180 	select HAVE_ARCH_SECCOMP_FILTER
181 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
182 	select HAVE_ARCH_STACKLEAK
183 	select HAVE_ARCH_TRACEHOOK
184 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
185 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
186 	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
187 	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
188 	select HAVE_ARCH_VMAP_STACK		if X86_64
189 	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
190 	select HAVE_ARCH_WITHIN_STACK_FRAMES
191 	select HAVE_ASM_MODVERSIONS
192 	select HAVE_CMPXCHG_DOUBLE
193 	select HAVE_CMPXCHG_LOCAL
194 	select HAVE_CONTEXT_TRACKING_USER		if X86_64
195 	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
196 	select HAVE_C_RECORDMCOUNT
197 	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
198 	select HAVE_BUILDTIME_MCOUNT_SORT
199 	select HAVE_DEBUG_KMEMLEAK
200 	select HAVE_DMA_CONTIGUOUS
201 	select HAVE_DYNAMIC_FTRACE
202 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
203 	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
204 	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
205 	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
206 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
207 	select HAVE_EBPF_JIT
208 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
209 	select HAVE_EISA
210 	select HAVE_EXIT_THREAD
211 	select HAVE_FAST_GUP
212 	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
213 	select HAVE_FTRACE_MCOUNT_RECORD
214 	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
215 	select HAVE_FUNCTION_TRACER
216 	select HAVE_GCC_PLUGINS
217 	select HAVE_HW_BREAKPOINT
218 	select HAVE_IOREMAP_PROT
219 	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
220 	select HAVE_IRQ_TIME_ACCOUNTING
221 	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
222 	select HAVE_KERNEL_BZIP2
223 	select HAVE_KERNEL_GZIP
224 	select HAVE_KERNEL_LZ4
225 	select HAVE_KERNEL_LZMA
226 	select HAVE_KERNEL_LZO
227 	select HAVE_KERNEL_XZ
228 	select HAVE_KERNEL_ZSTD
229 	select HAVE_KPROBES
230 	select HAVE_KPROBES_ON_FTRACE
231 	select HAVE_FUNCTION_ERROR_INJECTION
232 	select HAVE_KRETPROBES
233 	select HAVE_RETHOOK
234 	select HAVE_KVM
235 	select HAVE_LIVEPATCH			if X86_64
236 	select HAVE_MIXED_BREAKPOINTS_REGS
237 	select HAVE_MOD_ARCH_SPECIFIC
238 	select HAVE_MOVE_PMD
239 	select HAVE_MOVE_PUD
240 	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
241 	select HAVE_NMI
242 	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
243 	select HAVE_OBJTOOL			if X86_64
244 	select HAVE_OPTPROBES
245 	select HAVE_PCSPKR_PLATFORM
246 	select HAVE_PERF_EVENTS
247 	select HAVE_PERF_EVENTS_NMI
248 	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
249 	select HAVE_PCI
250 	select HAVE_PERF_REGS
251 	select HAVE_PERF_USER_STACK_DUMP
252 	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
253 	select MMU_GATHER_MERGE_VMAS
254 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
255 	select HAVE_REGS_AND_STACK_ACCESS_API
256 	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
257 	select HAVE_FUNCTION_ARG_ACCESS_API
258 	select HAVE_SETUP_PER_CPU_AREA
259 	select HAVE_SOFTIRQ_ON_OWN_STACK
260 	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
261 	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
262 	select HAVE_STATIC_CALL
263 	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
264 	select HAVE_PREEMPT_DYNAMIC_CALL
265 	select HAVE_RSEQ
266 	select HAVE_RUST			if X86_64
267 	select HAVE_SYSCALL_TRACEPOINTS
268 	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
269 	select HAVE_UNSTABLE_SCHED_CLOCK
270 	select HAVE_USER_RETURN_NOTIFIER
271 	select HAVE_GENERIC_VDSO
272 	select HOTPLUG_SMT			if SMP
273 	select IRQ_FORCED_THREADING
274 	select NEED_PER_CPU_EMBED_FIRST_CHUNK
275 	select NEED_PER_CPU_PAGE_FIRST_CHUNK
276 	select NEED_SG_DMA_LENGTH
277 	select PCI_DOMAINS			if PCI
278 	select PCI_LOCKLESS_CONFIG		if PCI
279 	select PERF_EVENTS
280 	select RTC_LIB
281 	select RTC_MC146818_LIB
282 	select SPARSE_IRQ
283 	select SRCU
284 	select SYSCTL_EXCEPTION_TRACE
285 	select THREAD_INFO_IN_TASK
286 	select TRACE_IRQFLAGS_SUPPORT
287 	select TRACE_IRQFLAGS_NMI_SUPPORT
288 	select USER_STACKTRACE_SUPPORT
289 	select HAVE_ARCH_KCSAN			if X86_64
290 	select X86_FEATURE_NAMES		if PROC_FS
291 	select PROC_PID_ARCH_STATUS		if PROC_FS
292 	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
293 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
294 	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
295 
296 config INSTRUCTION_DECODER
297 	def_bool y
298 	depends on KPROBES || PERF_EVENTS || UPROBES
299 
300 config OUTPUT_FORMAT
301 	string
302 	default "elf32-i386" if X86_32
303 	default "elf64-x86-64" if X86_64
304 
305 config LOCKDEP_SUPPORT
306 	def_bool y
307 
308 config STACKTRACE_SUPPORT
309 	def_bool y
310 
311 config MMU
312 	def_bool y
313 
314 config ARCH_MMAP_RND_BITS_MIN
315 	default 28 if 64BIT
316 	default 8
317 
318 config ARCH_MMAP_RND_BITS_MAX
319 	default 32 if 64BIT
320 	default 16
321 
322 config ARCH_MMAP_RND_COMPAT_BITS_MIN
323 	default 8
324 
325 config ARCH_MMAP_RND_COMPAT_BITS_MAX
326 	default 16
327 
328 config SBUS
329 	bool
330 
331 config GENERIC_ISA_DMA
332 	def_bool y
333 	depends on ISA_DMA_API
334 
335 config GENERIC_CSUM
336 	bool
337 	default y if KMSAN || KASAN
338 
339 config GENERIC_BUG
340 	def_bool y
341 	depends on BUG
342 	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
343 
344 config GENERIC_BUG_RELATIVE_POINTERS
345 	bool
346 
347 config ARCH_MAY_HAVE_PC_FDC
348 	def_bool y
349 	depends on ISA_DMA_API
350 
351 config GENERIC_CALIBRATE_DELAY
352 	def_bool y
353 
354 config ARCH_HAS_CPU_RELAX
355 	def_bool y
356 
357 config ARCH_HIBERNATION_POSSIBLE
358 	def_bool y
359 
360 config ARCH_NR_GPIO
361 	int
362 	default 1024 if X86_64
363 	default 512
364 
365 config ARCH_SUSPEND_POSSIBLE
366 	def_bool y
367 
368 config AUDIT_ARCH
369 	def_bool y if X86_64
370 
371 config KASAN_SHADOW_OFFSET
372 	hex
373 	depends on KASAN
374 	default 0xdffffc0000000000
375 
376 config HAVE_INTEL_TXT
377 	def_bool y
378 	depends on INTEL_IOMMU && ACPI
379 
380 config X86_32_SMP
381 	def_bool y
382 	depends on X86_32 && SMP
383 
384 config X86_64_SMP
385 	def_bool y
386 	depends on X86_64 && SMP
387 
388 config ARCH_SUPPORTS_UPROBES
389 	def_bool y
390 
391 config FIX_EARLYCON_MEM
392 	def_bool y
393 
394 config DYNAMIC_PHYSICAL_MASK
395 	bool
396 
397 config PGTABLE_LEVELS
398 	int
399 	default 5 if X86_5LEVEL
400 	default 4 if X86_64
401 	default 3 if X86_PAE
402 	default 2
403 
404 config CC_HAS_SANE_STACKPROTECTOR
405 	bool
406 	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
407 	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
408 	help
409 	  We have to make sure stack protector is unconditionally disabled if
410 	  the compiler produces broken code or if it does not let us control
411 	  the segment on 32-bit kernels.
412 
413 menu "Processor type and features"
414 
415 config SMP
416 	bool "Symmetric multi-processing support"
417 	help
418 	  This enables support for systems with more than one CPU. If you have
419 	  a system with only one CPU, say N. If you have a system with more
420 	  than one CPU, say Y.
421 
422 	  If you say N here, the kernel will run on uni- and multiprocessor
423 	  machines, but will use only one CPU of a multiprocessor machine. If
424 	  you say Y here, the kernel will run on many, but not all,
425 	  uniprocessor machines. On a uniprocessor machine, the kernel
426 	  will run faster if you say N here.
427 
428 	  Note that if you say Y here and choose architecture "586" or
429 	  "Pentium" under "Processor family", the kernel will not work on 486
430 	  architectures. Similarly, multiprocessor kernels for the "PPro"
431 	  architecture may not work on all Pentium based boards.
432 
433 	  People using multiprocessor machines who say Y here should also say
434 	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
435 	  Management" code will be disabled if you say Y here.
436 
437 	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
438 	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
439 	  <http://www.tldp.org/docs.html#howto>.
440 
441 	  If you don't know what to do here, say N.
442 
443 config X86_FEATURE_NAMES
444 	bool "Processor feature human-readable names" if EMBEDDED
445 	default y
446 	help
447 	  This option compiles in a table of x86 feature bits and corresponding
448 	  names.  This is required to support /proc/cpuinfo and a few kernel
449 	  messages.  You can disable this to save space, at the expense of
450 	  making those few kernel messages show numeric feature bits instead.
451 
452 	  If in doubt, say Y.
453 
454 config X86_X2APIC
455 	bool "Support x2apic"
456 	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
457 	help
458 	  This enables x2apic support on CPUs that have this feature.
459 
460 	  This allows 32-bit apic IDs (so it can support very large systems),
461 	  and accesses the local apic via MSRs not via mmio.
462 
463 	  Some Intel systems circa 2022 and later are locked into x2APIC mode
464 	  and can not fall back to the legacy APIC modes if SGX or TDX are
465 	  enabled in the BIOS.  They will be unable to boot without enabling
466 	  this option.
467 
468 	  If you don't know what to do here, say N.
469 
470 config X86_MPPARSE
471 	bool "Enable MPS table" if ACPI
472 	default y
473 	depends on X86_LOCAL_APIC
474 	help
475 	  For old smp systems that do not have proper acpi support. Newer systems
476 	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
477 
478 config GOLDFISH
479 	def_bool y
480 	depends on X86_GOLDFISH
481 
482 config X86_CPU_RESCTRL
483 	bool "x86 CPU resource control support"
484 	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
485 	select KERNFS
486 	select PROC_CPU_RESCTRL		if PROC_FS
487 	help
488 	  Enable x86 CPU resource control support.
489 
490 	  Provide support for the allocation and monitoring of system resources
491 	  usage by the CPU.
492 
493 	  Intel calls this Intel Resource Director Technology
494 	  (Intel(R) RDT). More information about RDT can be found in the
495 	  Intel x86 Architecture Software Developer Manual.
496 
497 	  AMD calls this AMD Platform Quality of Service (AMD QoS).
498 	  More information about AMD QoS can be found in the AMD64 Technology
499 	  Platform Quality of Service Extensions manual.
500 
501 	  Say N if unsure.
502 
503 if X86_32
504 config X86_BIGSMP
505 	bool "Support for big SMP systems with more than 8 CPUs"
506 	depends on SMP
507 	help
508 	  This option is needed for the systems that have more than 8 CPUs.
509 
510 config X86_EXTENDED_PLATFORM
511 	bool "Support for extended (non-PC) x86 platforms"
512 	default y
513 	help
514 	  If you disable this option then the kernel will only support
515 	  standard PC platforms. (which covers the vast majority of
516 	  systems out there.)
517 
518 	  If you enable this option then you'll be able to select support
519 	  for the following (non-PC) 32 bit x86 platforms:
520 		Goldfish (Android emulator)
521 		AMD Elan
522 		RDC R-321x SoC
523 		SGI 320/540 (Visual Workstation)
524 		STA2X11-based (e.g. Northville)
525 		Moorestown MID devices
526 
527 	  If you have one of these systems, or if you want to build a
528 	  generic distribution kernel, say Y here - otherwise say N.
529 endif # X86_32
530 
531 if X86_64
532 config X86_EXTENDED_PLATFORM
533 	bool "Support for extended (non-PC) x86 platforms"
534 	default y
535 	help
536 	  If you disable this option then the kernel will only support
537 	  standard PC platforms. (which covers the vast majority of
538 	  systems out there.)
539 
540 	  If you enable this option then you'll be able to select support
541 	  for the following (non-PC) 64 bit x86 platforms:
542 		Numascale NumaChip
543 		ScaleMP vSMP
544 		SGI Ultraviolet
545 
546 	  If you have one of these systems, or if you want to build a
547 	  generic distribution kernel, say Y here - otherwise say N.
548 endif # X86_64
549 # This is an alphabetically sorted list of 64 bit extended platforms
550 # Please maintain the alphabetic order if and when there are additions
551 config X86_NUMACHIP
552 	bool "Numascale NumaChip"
553 	depends on X86_64
554 	depends on X86_EXTENDED_PLATFORM
555 	depends on NUMA
556 	depends on SMP
557 	depends on X86_X2APIC
558 	depends on PCI_MMCONFIG
559 	help
560 	  Adds support for Numascale NumaChip large-SMP systems. Needed to
561 	  enable more than ~168 cores.
562 	  If you don't have one of these, you should say N here.
563 
564 config X86_VSMP
565 	bool "ScaleMP vSMP"
566 	select HYPERVISOR_GUEST
567 	select PARAVIRT
568 	depends on X86_64 && PCI
569 	depends on X86_EXTENDED_PLATFORM
570 	depends on SMP
571 	help
572 	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
573 	  supposed to run on these EM64T-based machines.  Only choose this option
574 	  if you have one of these machines.
575 
576 config X86_UV
577 	bool "SGI Ultraviolet"
578 	depends on X86_64
579 	depends on X86_EXTENDED_PLATFORM
580 	depends on NUMA
581 	depends on EFI
582 	depends on KEXEC_CORE
583 	depends on X86_X2APIC
584 	depends on PCI
585 	help
586 	  This option is needed in order to support SGI Ultraviolet systems.
587 	  If you don't have one of these, you should say N here.
588 
589 # Following is an alphabetically sorted list of 32 bit extended platforms
590 # Please maintain the alphabetic order if and when there are additions
591 
592 config X86_GOLDFISH
593 	bool "Goldfish (Virtual Platform)"
594 	depends on X86_EXTENDED_PLATFORM
595 	help
596 	  Enable support for the Goldfish virtual platform used primarily
597 	  for Android development. Unless you are building for the Android
598 	  Goldfish emulator say N here.
599 
600 config X86_INTEL_CE
601 	bool "CE4100 TV platform"
602 	depends on PCI
603 	depends on PCI_GODIRECT
604 	depends on X86_IO_APIC
605 	depends on X86_32
606 	depends on X86_EXTENDED_PLATFORM
607 	select X86_REBOOTFIXUPS
608 	select OF
609 	select OF_EARLY_FLATTREE
610 	help
611 	  Select for the Intel CE media processor (CE4100) SOC.
612 	  This option compiles in support for the CE4100 SOC for settop
613 	  boxes and media devices.
614 
615 config X86_INTEL_MID
616 	bool "Intel MID platform support"
617 	depends on X86_EXTENDED_PLATFORM
618 	depends on X86_PLATFORM_DEVICES
619 	depends on PCI
620 	depends on X86_64 || (PCI_GOANY && X86_32)
621 	depends on X86_IO_APIC
622 	select I2C
623 	select DW_APB_TIMER
624 	select INTEL_SCU_PCI
625 	help
626 	  Select to build a kernel capable of supporting Intel MID (Mobile
627 	  Internet Device) platform systems which do not have the PCI legacy
628 	  interfaces. If you are building for a PC class system say N here.
629 
630 	  Intel MID platforms are based on an Intel processor and chipset which
631 	  consume less power than most of the x86 derivatives.
632 
633 config X86_INTEL_QUARK
634 	bool "Intel Quark platform support"
635 	depends on X86_32
636 	depends on X86_EXTENDED_PLATFORM
637 	depends on X86_PLATFORM_DEVICES
638 	depends on X86_TSC
639 	depends on PCI
640 	depends on PCI_GOANY
641 	depends on X86_IO_APIC
642 	select IOSF_MBI
643 	select INTEL_IMR
644 	select COMMON_CLK
645 	help
646 	  Select to include support for Quark X1000 SoC.
647 	  Say Y here if you have a Quark based system such as the Arduino
648 	  compatible Intel Galileo.
649 
650 config X86_INTEL_LPSS
651 	bool "Intel Low Power Subsystem Support"
652 	depends on X86 && ACPI && PCI
653 	select COMMON_CLK
654 	select PINCTRL
655 	select IOSF_MBI
656 	help
657 	  Select to build support for Intel Low Power Subsystem such as
658 	  found on Intel Lynxpoint PCH. Selecting this option enables
659 	  things like clock tree (common clock framework) and pincontrol
660 	  which are needed by the LPSS peripheral drivers.
661 
662 config X86_AMD_PLATFORM_DEVICE
663 	bool "AMD ACPI2Platform devices support"
664 	depends on ACPI
665 	select COMMON_CLK
666 	select PINCTRL
667 	help
668 	  Select to interpret AMD specific ACPI device to platform device
669 	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
670 	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
671 	  implemented under PINCTRL subsystem.
672 
673 config IOSF_MBI
674 	tristate "Intel SoC IOSF Sideband support for SoC platforms"
675 	depends on PCI
676 	help
677 	  This option enables sideband register access support for Intel SoC
678 	  platforms. On these platforms the IOSF sideband is used in lieu of
679 	  MSR's for some register accesses, mostly but not limited to thermal
680 	  and power. Drivers may query the availability of this device to
681 	  determine if they need the sideband in order to work on these
682 	  platforms. The sideband is available on the following SoC products.
683 	  This list is not meant to be exclusive.
684 	   - BayTrail
685 	   - Braswell
686 	   - Quark
687 
688 	  You should say Y if you are running a kernel on one of these SoC's.
689 
690 config IOSF_MBI_DEBUG
691 	bool "Enable IOSF sideband access through debugfs"
692 	depends on IOSF_MBI && DEBUG_FS
693 	help
694 	  Select this option to expose the IOSF sideband access registers (MCR,
695 	  MDR, MCRX) through debugfs to write and read register information from
696 	  different units on the SoC. This is most useful for obtaining device
697 	  state information for debug and analysis. As this is a general access
698 	  mechanism, users of this option would have specific knowledge of the
699 	  device they want to access.
700 
701 	  If you don't require the option or are in doubt, say N.
702 
703 config X86_RDC321X
704 	bool "RDC R-321x SoC"
705 	depends on X86_32
706 	depends on X86_EXTENDED_PLATFORM
707 	select M486
708 	select X86_REBOOTFIXUPS
709 	help
710 	  This option is needed for RDC R-321x system-on-chip, also known
711 	  as R-8610-(G).
712 	  If you don't have one of these chips, you should say N here.
713 
714 config X86_32_NON_STANDARD
715 	bool "Support non-standard 32-bit SMP architectures"
716 	depends on X86_32 && SMP
717 	depends on X86_EXTENDED_PLATFORM
718 	help
719 	  This option compiles in the bigsmp and STA2X11 default
720 	  subarchitectures.  It is intended for a generic binary
721 	  kernel. If you select them all, kernel will probe it one by
722 	  one and will fallback to default.
723 
724 # Alphabetically sorted list of Non standard 32 bit platforms
725 
726 config X86_SUPPORTS_MEMORY_FAILURE
727 	def_bool y
728 	# MCE code calls memory_failure():
729 	depends on X86_MCE
730 	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
731 	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
732 	depends on X86_64 || !SPARSEMEM
733 	select ARCH_SUPPORTS_MEMORY_FAILURE
734 
735 config STA2X11
736 	bool "STA2X11 Companion Chip Support"
737 	depends on X86_32_NON_STANDARD && PCI
738 	select SWIOTLB
739 	select MFD_STA2X11
740 	select GPIOLIB
741 	help
742 	  This adds support for boards based on the STA2X11 IO-Hub,
743 	  a.k.a. "ConneXt". The chip is used in place of the standard
744 	  PC chipset, so all "standard" peripherals are missing. If this
745 	  option is selected the kernel will still be able to boot on
746 	  standard PC machines.
747 
748 config X86_32_IRIS
749 	tristate "Eurobraille/Iris poweroff module"
750 	depends on X86_32
751 	help
752 	  The Iris machines from EuroBraille do not have APM or ACPI support
753 	  to shut themselves down properly.  A special I/O sequence is
754 	  needed to do so, which is what this module does at
755 	  kernel shutdown.
756 
757 	  This is only for Iris machines from EuroBraille.
758 
759 	  If unused, say N.
760 
761 config SCHED_OMIT_FRAME_POINTER
762 	def_bool y
763 	prompt "Single-depth WCHAN output"
764 	depends on X86
765 	help
766 	  Calculate simpler /proc/<PID>/wchan values. If this option
767 	  is disabled then wchan values will recurse back to the
768 	  caller function. This provides more accurate wchan values,
769 	  at the expense of slightly more scheduling overhead.
770 
771 	  If in doubt, say "Y".
772 
773 menuconfig HYPERVISOR_GUEST
774 	bool "Linux guest support"
775 	help
776 	  Say Y here to enable options for running Linux under various hyper-
777 	  visors. This option enables basic hypervisor detection and platform
778 	  setup.
779 
780 	  If you say N, all options in this submenu will be skipped and
781 	  disabled, and Linux guest support won't be built in.
782 
783 if HYPERVISOR_GUEST
784 
785 config PARAVIRT
786 	bool "Enable paravirtualization code"
787 	depends on HAVE_STATIC_CALL
788 	help
789 	  This changes the kernel so it can modify itself when it is run
790 	  under a hypervisor, potentially improving performance significantly
791 	  over full virtualization.  However, when run without a hypervisor
792 	  the kernel is theoretically slower and slightly larger.
793 
794 config PARAVIRT_XXL
795 	bool
796 
797 config PARAVIRT_DEBUG
798 	bool "paravirt-ops debugging"
799 	depends on PARAVIRT && DEBUG_KERNEL
800 	help
801 	  Enable to debug paravirt_ops internals.  Specifically, BUG if
802 	  a paravirt_op is missing when it is called.
803 
804 config PARAVIRT_SPINLOCKS
805 	bool "Paravirtualization layer for spinlocks"
806 	depends on PARAVIRT && SMP
807 	help
808 	  Paravirtualized spinlocks allow a pvops backend to replace the
809 	  spinlock implementation with something virtualization-friendly
810 	  (for example, block the virtual CPU rather than spinning).
811 
812 	  It has a minimal impact on native kernels and gives a nice performance
813 	  benefit on paravirtualized KVM / Xen kernels.
814 
815 	  If you are unsure how to answer this question, answer Y.
816 
817 config X86_HV_CALLBACK_VECTOR
818 	def_bool n
819 
820 source "arch/x86/xen/Kconfig"
821 
822 config KVM_GUEST
823 	bool "KVM Guest support (including kvmclock)"
824 	depends on PARAVIRT
825 	select PARAVIRT_CLOCK
826 	select ARCH_CPUIDLE_HALTPOLL
827 	select X86_HV_CALLBACK_VECTOR
828 	default y
829 	help
830 	  This option enables various optimizations for running under the KVM
831 	  hypervisor. It includes a paravirtualized clock, so that instead
832 	  of relying on a PIT (or probably other) emulation by the
833 	  underlying device model, the host provides the guest with
834 	  timing infrastructure such as time of day, and system time
835 
836 config ARCH_CPUIDLE_HALTPOLL
837 	def_bool n
838 	prompt "Disable host haltpoll when loading haltpoll driver"
839 	help
840 	  If virtualized under KVM, disable host haltpoll.
841 
842 config PVH
843 	bool "Support for running PVH guests"
844 	help
845 	  This option enables the PVH entry point for guest virtual machines
846 	  as specified in the x86/HVM direct boot ABI.
847 
848 config PARAVIRT_TIME_ACCOUNTING
849 	bool "Paravirtual steal time accounting"
850 	depends on PARAVIRT
851 	help
852 	  Select this option to enable fine granularity task steal time
853 	  accounting. Time spent executing other tasks in parallel with
854 	  the current vCPU is discounted from the vCPU power. To account for
855 	  that, there can be a small performance impact.
856 
857 	  If in doubt, say N here.
858 
859 config PARAVIRT_CLOCK
860 	bool
861 
862 config JAILHOUSE_GUEST
863 	bool "Jailhouse non-root cell support"
864 	depends on X86_64 && PCI
865 	select X86_PM_TIMER
866 	help
867 	  This option allows to run Linux as guest in a Jailhouse non-root
868 	  cell. You can leave this option disabled if you only want to start
869 	  Jailhouse and run Linux afterwards in the root cell.
870 
871 config ACRN_GUEST
872 	bool "ACRN Guest support"
873 	depends on X86_64
874 	select X86_HV_CALLBACK_VECTOR
875 	help
876 	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
877 	  a flexible, lightweight reference open-source hypervisor, built with
878 	  real-time and safety-criticality in mind. It is built for embedded
879 	  IOT with small footprint and real-time features. More details can be
880 	  found in https://projectacrn.org/.
881 
882 config INTEL_TDX_GUEST
883 	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
884 	depends on X86_64 && CPU_SUP_INTEL
885 	depends on X86_X2APIC
886 	select ARCH_HAS_CC_PLATFORM
887 	select X86_MEM_ENCRYPT
888 	select X86_MCE
889 	help
890 	  Support running as a guest under Intel TDX.  Without this support,
891 	  the guest kernel can not boot or run under TDX.
892 	  TDX includes memory encryption and integrity capabilities
893 	  which protect the confidentiality and integrity of guest
894 	  memory contents and CPU state. TDX guests are protected from
895 	  some attacks from the VMM.
896 
897 endif # HYPERVISOR_GUEST
898 
899 source "arch/x86/Kconfig.cpu"
900 
901 config HPET_TIMER
902 	def_bool X86_64
903 	prompt "HPET Timer Support" if X86_32
904 	help
905 	  Use the IA-PC HPET (High Precision Event Timer) to manage
906 	  time in preference to the PIT and RTC, if a HPET is
907 	  present.
908 	  HPET is the next generation timer replacing legacy 8254s.
909 	  The HPET provides a stable time base on SMP
910 	  systems, unlike the TSC, but it is more expensive to access,
911 	  as it is off-chip.  The interface used is documented
912 	  in the HPET spec, revision 1.
913 
914 	  You can safely choose Y here.  However, HPET will only be
915 	  activated if the platform and the BIOS support this feature.
916 	  Otherwise the 8254 will be used for timing services.
917 
918 	  Choose N to continue using the legacy 8254 timer.
919 
920 config HPET_EMULATE_RTC
921 	def_bool y
922 	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
923 
924 # Mark as expert because too many people got it wrong.
925 # The code disables itself when not needed.
926 config DMI
927 	default y
928 	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
929 	bool "Enable DMI scanning" if EXPERT
930 	help
931 	  Enabled scanning of DMI to identify machine quirks. Say Y
932 	  here unless you have verified that your setup is not
933 	  affected by entries in the DMI blacklist. Required by PNP
934 	  BIOS code.
935 
936 config GART_IOMMU
937 	bool "Old AMD GART IOMMU support"
938 	select DMA_OPS
939 	select IOMMU_HELPER
940 	select SWIOTLB
941 	depends on X86_64 && PCI && AMD_NB
942 	help
943 	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
944 	  GART based hardware IOMMUs.
945 
946 	  The GART supports full DMA access for devices with 32-bit access
947 	  limitations, on systems with more than 3 GB. This is usually needed
948 	  for USB, sound, many IDE/SATA chipsets and some other devices.
949 
950 	  Newer systems typically have a modern AMD IOMMU, supported via
951 	  the CONFIG_AMD_IOMMU=y config option.
952 
953 	  In normal configurations this driver is only active when needed:
954 	  there's more than 3 GB of memory and the system contains a
955 	  32-bit limited device.
956 
957 	  If unsure, say Y.
958 
959 config BOOT_VESA_SUPPORT
960 	bool
961 	help
962 	  If true, at least one selected framebuffer driver can take advantage
963 	  of VESA video modes set at an early boot stage via the vga= parameter.
964 
965 config MAXSMP
966 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
967 	depends on X86_64 && SMP && DEBUG_KERNEL
968 	select CPUMASK_OFFSTACK
969 	help
970 	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
971 	  If unsure, say N.
972 
973 #
974 # The maximum number of CPUs supported:
975 #
976 # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
977 # and which can be configured interactively in the
978 # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
979 #
980 # The ranges are different on 32-bit and 64-bit kernels, depending on
981 # hardware capabilities and scalability features of the kernel.
982 #
983 # ( If MAXSMP is enabled we just use the highest possible value and disable
984 #   interactive configuration. )
985 #
986 
987 config NR_CPUS_RANGE_BEGIN
988 	int
989 	default NR_CPUS_RANGE_END if MAXSMP
990 	default    1 if !SMP
991 	default    2
992 
993 config NR_CPUS_RANGE_END
994 	int
995 	depends on X86_32
996 	default   64 if  SMP &&  X86_BIGSMP
997 	default    8 if  SMP && !X86_BIGSMP
998 	default    1 if !SMP
999 
1000 config NR_CPUS_RANGE_END
1001 	int
1002 	depends on X86_64
1003 	default 8192 if  SMP && CPUMASK_OFFSTACK
1004 	default  512 if  SMP && !CPUMASK_OFFSTACK
1005 	default    1 if !SMP
1006 
1007 config NR_CPUS_DEFAULT
1008 	int
1009 	depends on X86_32
1010 	default   32 if  X86_BIGSMP
1011 	default    8 if  SMP
1012 	default    1 if !SMP
1013 
1014 config NR_CPUS_DEFAULT
1015 	int
1016 	depends on X86_64
1017 	default 8192 if  MAXSMP
1018 	default   64 if  SMP
1019 	default    1 if !SMP
1020 
1021 config NR_CPUS
1022 	int "Maximum number of CPUs" if SMP && !MAXSMP
1023 	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1024 	default NR_CPUS_DEFAULT
1025 	help
1026 	  This allows you to specify the maximum number of CPUs which this
1027 	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1028 	  supported value is 8192, otherwise the maximum value is 512.  The
1029 	  minimum value which makes sense is 2.
1030 
1031 	  This is purely to save memory: each supported CPU adds about 8KB
1032 	  to the kernel image.
1033 
1034 config SCHED_CLUSTER
1035 	bool "Cluster scheduler support"
1036 	depends on SMP
1037 	default y
1038 	help
1039 	  Cluster scheduler support improves the CPU scheduler's decision
1040 	  making when dealing with machines that have clusters of CPUs.
1041 	  Cluster usually means a couple of CPUs which are placed closely
1042 	  by sharing mid-level caches, last-level cache tags or internal
1043 	  busses.
1044 
1045 config SCHED_SMT
1046 	def_bool y if SMP
1047 
1048 config SCHED_MC
1049 	def_bool y
1050 	prompt "Multi-core scheduler support"
1051 	depends on SMP
1052 	help
1053 	  Multi-core scheduler support improves the CPU scheduler's decision
1054 	  making when dealing with multi-core CPU chips at a cost of slightly
1055 	  increased overhead in some places. If unsure say N here.
1056 
1057 config SCHED_MC_PRIO
1058 	bool "CPU core priorities scheduler support"
1059 	depends on SCHED_MC && CPU_SUP_INTEL
1060 	select X86_INTEL_PSTATE
1061 	select CPU_FREQ
1062 	default y
1063 	help
1064 	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1065 	  core ordering determined at manufacturing time, which allows
1066 	  certain cores to reach higher turbo frequencies (when running
1067 	  single threaded workloads) than others.
1068 
1069 	  Enabling this kernel feature teaches the scheduler about
1070 	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1071 	  scheduler's CPU selection logic accordingly, so that higher
1072 	  overall system performance can be achieved.
1073 
1074 	  This feature will have no effect on CPUs without this feature.
1075 
1076 	  If unsure say Y here.
1077 
1078 config UP_LATE_INIT
1079 	def_bool y
1080 	depends on !SMP && X86_LOCAL_APIC
1081 
1082 config X86_UP_APIC
1083 	bool "Local APIC support on uniprocessors" if !PCI_MSI
1084 	default PCI_MSI
1085 	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1086 	help
1087 	  A local APIC (Advanced Programmable Interrupt Controller) is an
1088 	  integrated interrupt controller in the CPU. If you have a single-CPU
1089 	  system which has a processor with a local APIC, you can say Y here to
1090 	  enable and use it. If you say Y here even though your machine doesn't
1091 	  have a local APIC, then the kernel will still run with no slowdown at
1092 	  all. The local APIC supports CPU-generated self-interrupts (timer,
1093 	  performance counters), and the NMI watchdog which detects hard
1094 	  lockups.
1095 
1096 config X86_UP_IOAPIC
1097 	bool "IO-APIC support on uniprocessors"
1098 	depends on X86_UP_APIC
1099 	help
1100 	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1101 	  SMP-capable replacement for PC-style interrupt controllers. Most
1102 	  SMP systems and many recent uniprocessor systems have one.
1103 
1104 	  If you have a single-CPU system with an IO-APIC, you can say Y here
1105 	  to use it. If you say Y here even though your machine doesn't have
1106 	  an IO-APIC, then the kernel will still run with no slowdown at all.
1107 
1108 config X86_LOCAL_APIC
1109 	def_bool y
1110 	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1111 	select IRQ_DOMAIN_HIERARCHY
1112 	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1113 
1114 config X86_IO_APIC
1115 	def_bool y
1116 	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1117 
1118 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1119 	bool "Reroute for broken boot IRQs"
1120 	depends on X86_IO_APIC
1121 	help
1122 	  This option enables a workaround that fixes a source of
1123 	  spurious interrupts. This is recommended when threaded
1124 	  interrupt handling is used on systems where the generation of
1125 	  superfluous "boot interrupts" cannot be disabled.
1126 
1127 	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1128 	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1129 	  kernel does during interrupt handling). On chipsets where this
1130 	  boot IRQ generation cannot be disabled, this workaround keeps
1131 	  the original IRQ line masked so that only the equivalent "boot
1132 	  IRQ" is delivered to the CPUs. The workaround also tells the
1133 	  kernel to set up the IRQ handler on the boot IRQ line. In this
1134 	  way only one interrupt is delivered to the kernel. Otherwise
1135 	  the spurious second interrupt may cause the kernel to bring
1136 	  down (vital) interrupt lines.
1137 
1138 	  Only affects "broken" chipsets. Interrupt sharing may be
1139 	  increased on these systems.
1140 
1141 config X86_MCE
1142 	bool "Machine Check / overheating reporting"
1143 	select GENERIC_ALLOCATOR
1144 	default y
1145 	help
1146 	  Machine Check support allows the processor to notify the
1147 	  kernel if it detects a problem (e.g. overheating, data corruption).
1148 	  The action the kernel takes depends on the severity of the problem,
1149 	  ranging from warning messages to halting the machine.
1150 
1151 config X86_MCELOG_LEGACY
1152 	bool "Support for deprecated /dev/mcelog character device"
1153 	depends on X86_MCE
1154 	help
1155 	  Enable support for /dev/mcelog which is needed by the old mcelog
1156 	  userspace logging daemon. Consider switching to the new generation
1157 	  rasdaemon solution.
1158 
1159 config X86_MCE_INTEL
1160 	def_bool y
1161 	prompt "Intel MCE features"
1162 	depends on X86_MCE && X86_LOCAL_APIC
1163 	help
1164 	  Additional support for intel specific MCE features such as
1165 	  the thermal monitor.
1166 
1167 config X86_MCE_AMD
1168 	def_bool y
1169 	prompt "AMD MCE features"
1170 	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1171 	help
1172 	  Additional support for AMD specific MCE features such as
1173 	  the DRAM Error Threshold.
1174 
1175 config X86_ANCIENT_MCE
1176 	bool "Support for old Pentium 5 / WinChip machine checks"
1177 	depends on X86_32 && X86_MCE
1178 	help
1179 	  Include support for machine check handling on old Pentium 5 or WinChip
1180 	  systems. These typically need to be enabled explicitly on the command
1181 	  line.
1182 
1183 config X86_MCE_THRESHOLD
1184 	depends on X86_MCE_AMD || X86_MCE_INTEL
1185 	def_bool y
1186 
1187 config X86_MCE_INJECT
1188 	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1189 	tristate "Machine check injector support"
1190 	help
1191 	  Provide support for injecting machine checks for testing purposes.
1192 	  If you don't know what a machine check is and you don't do kernel
1193 	  QA it is safe to say n.
1194 
1195 source "arch/x86/events/Kconfig"
1196 
1197 config X86_LEGACY_VM86
1198 	bool "Legacy VM86 support"
1199 	depends on X86_32
1200 	help
1201 	  This option allows user programs to put the CPU into V8086
1202 	  mode, which is an 80286-era approximation of 16-bit real mode.
1203 
1204 	  Some very old versions of X and/or vbetool require this option
1205 	  for user mode setting.  Similarly, DOSEMU will use it if
1206 	  available to accelerate real mode DOS programs.  However, any
1207 	  recent version of DOSEMU, X, or vbetool should be fully
1208 	  functional even without kernel VM86 support, as they will all
1209 	  fall back to software emulation. Nevertheless, if you are using
1210 	  a 16-bit DOS program where 16-bit performance matters, vm86
1211 	  mode might be faster than emulation and you might want to
1212 	  enable this option.
1213 
1214 	  Note that any app that works on a 64-bit kernel is unlikely to
1215 	  need this option, as 64-bit kernels don't, and can't, support
1216 	  V8086 mode. This option is also unrelated to 16-bit protected
1217 	  mode and is not needed to run most 16-bit programs under Wine.
1218 
1219 	  Enabling this option increases the complexity of the kernel
1220 	  and slows down exception handling a tiny bit.
1221 
1222 	  If unsure, say N here.
1223 
1224 config VM86
1225 	bool
1226 	default X86_LEGACY_VM86
1227 
1228 config X86_16BIT
1229 	bool "Enable support for 16-bit segments" if EXPERT
1230 	default y
1231 	depends on MODIFY_LDT_SYSCALL
1232 	help
1233 	  This option is required by programs like Wine to run 16-bit
1234 	  protected mode legacy code on x86 processors.  Disabling
1235 	  this option saves about 300 bytes on i386, or around 6K text
1236 	  plus 16K runtime memory on x86-64,
1237 
1238 config X86_ESPFIX32
1239 	def_bool y
1240 	depends on X86_16BIT && X86_32
1241 
1242 config X86_ESPFIX64
1243 	def_bool y
1244 	depends on X86_16BIT && X86_64
1245 
1246 config X86_VSYSCALL_EMULATION
1247 	bool "Enable vsyscall emulation" if EXPERT
1248 	default y
1249 	depends on X86_64
1250 	help
1251 	  This enables emulation of the legacy vsyscall page.  Disabling
1252 	  it is roughly equivalent to booting with vsyscall=none, except
1253 	  that it will also disable the helpful warning if a program
1254 	  tries to use a vsyscall.  With this option set to N, offending
1255 	  programs will just segfault, citing addresses of the form
1256 	  0xffffffffff600?00.
1257 
1258 	  This option is required by many programs built before 2013, and
1259 	  care should be used even with newer programs if set to N.
1260 
1261 	  Disabling this option saves about 7K of kernel size and
1262 	  possibly 4K of additional runtime pagetable memory.
1263 
1264 config X86_IOPL_IOPERM
1265 	bool "IOPERM and IOPL Emulation"
1266 	default y
1267 	help
1268 	  This enables the ioperm() and iopl() syscalls which are necessary
1269 	  for legacy applications.
1270 
1271 	  Legacy IOPL support is an overbroad mechanism which allows user
1272 	  space aside of accessing all 65536 I/O ports also to disable
1273 	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1274 	  capabilities and permission from potentially active security
1275 	  modules.
1276 
1277 	  The emulation restricts the functionality of the syscall to
1278 	  only allowing the full range I/O port access, but prevents the
1279 	  ability to disable interrupts from user space which would be
1280 	  granted if the hardware IOPL mechanism would be used.
1281 
1282 config TOSHIBA
1283 	tristate "Toshiba Laptop support"
1284 	depends on X86_32
1285 	help
1286 	  This adds a driver to safely access the System Management Mode of
1287 	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1288 	  not work on models with a Phoenix BIOS. The System Management Mode
1289 	  is used to set the BIOS and power saving options on Toshiba portables.
1290 
1291 	  For information on utilities to make use of this driver see the
1292 	  Toshiba Linux utilities web site at:
1293 	  <http://www.buzzard.org.uk/toshiba/>.
1294 
1295 	  Say Y if you intend to run this kernel on a Toshiba portable.
1296 	  Say N otherwise.
1297 
1298 config X86_REBOOTFIXUPS
1299 	bool "Enable X86 board specific fixups for reboot"
1300 	depends on X86_32
1301 	help
1302 	  This enables chipset and/or board specific fixups to be done
1303 	  in order to get reboot to work correctly. This is only needed on
1304 	  some combinations of hardware and BIOS. The symptom, for which
1305 	  this config is intended, is when reboot ends with a stalled/hung
1306 	  system.
1307 
1308 	  Currently, the only fixup is for the Geode machines using
1309 	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1310 
1311 	  Say Y if you want to enable the fixup. Currently, it's safe to
1312 	  enable this option even if you don't need it.
1313 	  Say N otherwise.
1314 
1315 config MICROCODE
1316 	bool "CPU microcode loading support"
1317 	default y
1318 	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1319 	help
1320 	  If you say Y here, you will be able to update the microcode on
1321 	  Intel and AMD processors. The Intel support is for the IA32 family,
1322 	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1323 	  AMD support is for families 0x10 and later. You will obviously need
1324 	  the actual microcode binary data itself which is not shipped with
1325 	  the Linux kernel.
1326 
1327 	  The preferred method to load microcode from a detached initrd is described
1328 	  in Documentation/x86/microcode.rst. For that you need to enable
1329 	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1330 	  initrd for microcode blobs.
1331 
1332 	  In addition, you can build the microcode into the kernel. For that you
1333 	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1334 	  config option.
1335 
1336 config MICROCODE_INTEL
1337 	bool "Intel microcode loading support"
1338 	depends on CPU_SUP_INTEL && MICROCODE
1339 	default MICROCODE
1340 	help
1341 	  This options enables microcode patch loading support for Intel
1342 	  processors.
1343 
1344 	  For the current Intel microcode data package go to
1345 	  <https://downloadcenter.intel.com> and search for
1346 	  'Linux Processor Microcode Data File'.
1347 
1348 config MICROCODE_AMD
1349 	bool "AMD microcode loading support"
1350 	depends on CPU_SUP_AMD && MICROCODE
1351 	help
1352 	  If you select this option, microcode patch loading support for AMD
1353 	  processors will be enabled.
1354 
1355 config MICROCODE_LATE_LOADING
1356 	bool "Late microcode loading (DANGEROUS)"
1357 	default n
1358 	depends on MICROCODE
1359 	help
1360 	  Loading microcode late, when the system is up and executing instructions
1361 	  is a tricky business and should be avoided if possible. Just the sequence
1362 	  of synchronizing all cores and SMT threads is one fragile dance which does
1363 	  not guarantee that cores might not softlock after the loading. Therefore,
1364 	  use this at your own risk. Late loading taints the kernel too.
1365 
1366 config X86_MSR
1367 	tristate "/dev/cpu/*/msr - Model-specific register support"
1368 	help
1369 	  This device gives privileged processes access to the x86
1370 	  Model-Specific Registers (MSRs).  It is a character device with
1371 	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1372 	  MSR accesses are directed to a specific CPU on multi-processor
1373 	  systems.
1374 
1375 config X86_CPUID
1376 	tristate "/dev/cpu/*/cpuid - CPU information support"
1377 	help
1378 	  This device gives processes access to the x86 CPUID instruction to
1379 	  be executed on a specific processor.  It is a character device
1380 	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1381 	  /dev/cpu/31/cpuid.
1382 
1383 choice
1384 	prompt "High Memory Support"
1385 	default HIGHMEM4G
1386 	depends on X86_32
1387 
1388 config NOHIGHMEM
1389 	bool "off"
1390 	help
1391 	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1392 	  However, the address space of 32-bit x86 processors is only 4
1393 	  Gigabytes large. That means that, if you have a large amount of
1394 	  physical memory, not all of it can be "permanently mapped" by the
1395 	  kernel. The physical memory that's not permanently mapped is called
1396 	  "high memory".
1397 
1398 	  If you are compiling a kernel which will never run on a machine with
1399 	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1400 	  choice and suitable for most users). This will result in a "3GB/1GB"
1401 	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1402 	  space and the remaining part of the 4GB virtual memory space is used
1403 	  by the kernel to permanently map as much physical memory as
1404 	  possible.
1405 
1406 	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1407 	  answer "4GB" here.
1408 
1409 	  If more than 4 Gigabytes is used then answer "64GB" here. This
1410 	  selection turns Intel PAE (Physical Address Extension) mode on.
1411 	  PAE implements 3-level paging on IA32 processors. PAE is fully
1412 	  supported by Linux, PAE mode is implemented on all recent Intel
1413 	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1414 	  then the kernel will not boot on CPUs that don't support PAE!
1415 
1416 	  The actual amount of total physical memory will either be
1417 	  auto detected or can be forced by using a kernel command line option
1418 	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1419 	  your boot loader (lilo or loadlin) about how to pass options to the
1420 	  kernel at boot time.)
1421 
1422 	  If unsure, say "off".
1423 
1424 config HIGHMEM4G
1425 	bool "4GB"
1426 	help
1427 	  Select this if you have a 32-bit processor and between 1 and 4
1428 	  gigabytes of physical RAM.
1429 
1430 config HIGHMEM64G
1431 	bool "64GB"
1432 	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1433 	select X86_PAE
1434 	help
1435 	  Select this if you have a 32-bit processor and more than 4
1436 	  gigabytes of physical RAM.
1437 
1438 endchoice
1439 
1440 choice
1441 	prompt "Memory split" if EXPERT
1442 	default VMSPLIT_3G
1443 	depends on X86_32
1444 	help
1445 	  Select the desired split between kernel and user memory.
1446 
1447 	  If the address range available to the kernel is less than the
1448 	  physical memory installed, the remaining memory will be available
1449 	  as "high memory". Accessing high memory is a little more costly
1450 	  than low memory, as it needs to be mapped into the kernel first.
1451 	  Note that increasing the kernel address space limits the range
1452 	  available to user programs, making the address space there
1453 	  tighter.  Selecting anything other than the default 3G/1G split
1454 	  will also likely make your kernel incompatible with binary-only
1455 	  kernel modules.
1456 
1457 	  If you are not absolutely sure what you are doing, leave this
1458 	  option alone!
1459 
1460 	config VMSPLIT_3G
1461 		bool "3G/1G user/kernel split"
1462 	config VMSPLIT_3G_OPT
1463 		depends on !X86_PAE
1464 		bool "3G/1G user/kernel split (for full 1G low memory)"
1465 	config VMSPLIT_2G
1466 		bool "2G/2G user/kernel split"
1467 	config VMSPLIT_2G_OPT
1468 		depends on !X86_PAE
1469 		bool "2G/2G user/kernel split (for full 2G low memory)"
1470 	config VMSPLIT_1G
1471 		bool "1G/3G user/kernel split"
1472 endchoice
1473 
1474 config PAGE_OFFSET
1475 	hex
1476 	default 0xB0000000 if VMSPLIT_3G_OPT
1477 	default 0x80000000 if VMSPLIT_2G
1478 	default 0x78000000 if VMSPLIT_2G_OPT
1479 	default 0x40000000 if VMSPLIT_1G
1480 	default 0xC0000000
1481 	depends on X86_32
1482 
1483 config HIGHMEM
1484 	def_bool y
1485 	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1486 
1487 config X86_PAE
1488 	bool "PAE (Physical Address Extension) Support"
1489 	depends on X86_32 && !HIGHMEM4G
1490 	select PHYS_ADDR_T_64BIT
1491 	select SWIOTLB
1492 	help
1493 	  PAE is required for NX support, and furthermore enables
1494 	  larger swapspace support for non-overcommit purposes. It
1495 	  has the cost of more pagetable lookup overhead, and also
1496 	  consumes more pagetable space per process.
1497 
1498 config X86_5LEVEL
1499 	bool "Enable 5-level page tables support"
1500 	default y
1501 	select DYNAMIC_MEMORY_LAYOUT
1502 	select SPARSEMEM_VMEMMAP
1503 	depends on X86_64
1504 	help
1505 	  5-level paging enables access to larger address space:
1506 	  upto 128 PiB of virtual address space and 4 PiB of
1507 	  physical address space.
1508 
1509 	  It will be supported by future Intel CPUs.
1510 
1511 	  A kernel with the option enabled can be booted on machines that
1512 	  support 4- or 5-level paging.
1513 
1514 	  See Documentation/x86/x86_64/5level-paging.rst for more
1515 	  information.
1516 
1517 	  Say N if unsure.
1518 
1519 config X86_DIRECT_GBPAGES
1520 	def_bool y
1521 	depends on X86_64
1522 	help
1523 	  Certain kernel features effectively disable kernel
1524 	  linear 1 GB mappings (even if the CPU otherwise
1525 	  supports them), so don't confuse the user by printing
1526 	  that we have them enabled.
1527 
1528 config X86_CPA_STATISTICS
1529 	bool "Enable statistic for Change Page Attribute"
1530 	depends on DEBUG_FS
1531 	help
1532 	  Expose statistics about the Change Page Attribute mechanism, which
1533 	  helps to determine the effectiveness of preserving large and huge
1534 	  page mappings when mapping protections are changed.
1535 
1536 config X86_MEM_ENCRYPT
1537 	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1538 	select DYNAMIC_PHYSICAL_MASK
1539 	def_bool n
1540 
1541 config AMD_MEM_ENCRYPT
1542 	bool "AMD Secure Memory Encryption (SME) support"
1543 	depends on X86_64 && CPU_SUP_AMD
1544 	select DMA_COHERENT_POOL
1545 	select ARCH_USE_MEMREMAP_PROT
1546 	select INSTRUCTION_DECODER
1547 	select ARCH_HAS_CC_PLATFORM
1548 	select X86_MEM_ENCRYPT
1549 	help
1550 	  Say yes to enable support for the encryption of system memory.
1551 	  This requires an AMD processor that supports Secure Memory
1552 	  Encryption (SME).
1553 
1554 config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1555 	bool "Activate AMD Secure Memory Encryption (SME) by default"
1556 	depends on AMD_MEM_ENCRYPT
1557 	help
1558 	  Say yes to have system memory encrypted by default if running on
1559 	  an AMD processor that supports Secure Memory Encryption (SME).
1560 
1561 	  If set to Y, then the encryption of system memory can be
1562 	  deactivated with the mem_encrypt=off command line option.
1563 
1564 	  If set to N, then the encryption of system memory can be
1565 	  activated with the mem_encrypt=on command line option.
1566 
1567 # Common NUMA Features
1568 config NUMA
1569 	bool "NUMA Memory Allocation and Scheduler Support"
1570 	depends on SMP
1571 	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1572 	default y if X86_BIGSMP
1573 	select USE_PERCPU_NUMA_NODE_ID
1574 	help
1575 	  Enable NUMA (Non-Uniform Memory Access) support.
1576 
1577 	  The kernel will try to allocate memory used by a CPU on the
1578 	  local memory controller of the CPU and add some more
1579 	  NUMA awareness to the kernel.
1580 
1581 	  For 64-bit this is recommended if the system is Intel Core i7
1582 	  (or later), AMD Opteron, or EM64T NUMA.
1583 
1584 	  For 32-bit this is only needed if you boot a 32-bit
1585 	  kernel on a 64-bit NUMA platform.
1586 
1587 	  Otherwise, you should say N.
1588 
1589 config AMD_NUMA
1590 	def_bool y
1591 	prompt "Old style AMD Opteron NUMA detection"
1592 	depends on X86_64 && NUMA && PCI
1593 	help
1594 	  Enable AMD NUMA node topology detection.  You should say Y here if
1595 	  you have a multi processor AMD system. This uses an old method to
1596 	  read the NUMA configuration directly from the builtin Northbridge
1597 	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1598 	  which also takes priority if both are compiled in.
1599 
1600 config X86_64_ACPI_NUMA
1601 	def_bool y
1602 	prompt "ACPI NUMA detection"
1603 	depends on X86_64 && NUMA && ACPI && PCI
1604 	select ACPI_NUMA
1605 	help
1606 	  Enable ACPI SRAT based node topology detection.
1607 
1608 config NUMA_EMU
1609 	bool "NUMA emulation"
1610 	depends on NUMA
1611 	help
1612 	  Enable NUMA emulation. A flat machine will be split
1613 	  into virtual nodes when booted with "numa=fake=N", where N is the
1614 	  number of nodes. This is only useful for debugging.
1615 
1616 config NODES_SHIFT
1617 	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1618 	range 1 10
1619 	default "10" if MAXSMP
1620 	default "6" if X86_64
1621 	default "3"
1622 	depends on NUMA
1623 	help
1624 	  Specify the maximum number of NUMA Nodes available on the target
1625 	  system.  Increases memory reserved to accommodate various tables.
1626 
1627 config ARCH_FLATMEM_ENABLE
1628 	def_bool y
1629 	depends on X86_32 && !NUMA
1630 
1631 config ARCH_SPARSEMEM_ENABLE
1632 	def_bool y
1633 	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1634 	select SPARSEMEM_STATIC if X86_32
1635 	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1636 
1637 config ARCH_SPARSEMEM_DEFAULT
1638 	def_bool X86_64 || (NUMA && X86_32)
1639 
1640 config ARCH_SELECT_MEMORY_MODEL
1641 	def_bool y
1642 	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1643 
1644 config ARCH_MEMORY_PROBE
1645 	bool "Enable sysfs memory/probe interface"
1646 	depends on MEMORY_HOTPLUG
1647 	help
1648 	  This option enables a sysfs memory/probe interface for testing.
1649 	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1650 	  If you are unsure how to answer this question, answer N.
1651 
1652 config ARCH_PROC_KCORE_TEXT
1653 	def_bool y
1654 	depends on X86_64 && PROC_KCORE
1655 
1656 config ILLEGAL_POINTER_VALUE
1657 	hex
1658 	default 0 if X86_32
1659 	default 0xdead000000000000 if X86_64
1660 
1661 config X86_PMEM_LEGACY_DEVICE
1662 	bool
1663 
1664 config X86_PMEM_LEGACY
1665 	tristate "Support non-standard NVDIMMs and ADR protected memory"
1666 	depends on PHYS_ADDR_T_64BIT
1667 	depends on BLK_DEV
1668 	select X86_PMEM_LEGACY_DEVICE
1669 	select NUMA_KEEP_MEMINFO if NUMA
1670 	select LIBNVDIMM
1671 	help
1672 	  Treat memory marked using the non-standard e820 type of 12 as used
1673 	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1674 	  The kernel will offer these regions to the 'pmem' driver so
1675 	  they can be used for persistent storage.
1676 
1677 	  Say Y if unsure.
1678 
1679 config HIGHPTE
1680 	bool "Allocate 3rd-level pagetables from highmem"
1681 	depends on HIGHMEM
1682 	help
1683 	  The VM uses one page table entry for each page of physical memory.
1684 	  For systems with a lot of RAM, this can be wasteful of precious
1685 	  low memory.  Setting this option will put user-space page table
1686 	  entries in high memory.
1687 
1688 config X86_CHECK_BIOS_CORRUPTION
1689 	bool "Check for low memory corruption"
1690 	help
1691 	  Periodically check for memory corruption in low memory, which
1692 	  is suspected to be caused by BIOS.  Even when enabled in the
1693 	  configuration, it is disabled at runtime.  Enable it by
1694 	  setting "memory_corruption_check=1" on the kernel command
1695 	  line.  By default it scans the low 64k of memory every 60
1696 	  seconds; see the memory_corruption_check_size and
1697 	  memory_corruption_check_period parameters in
1698 	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1699 
1700 	  When enabled with the default parameters, this option has
1701 	  almost no overhead, as it reserves a relatively small amount
1702 	  of memory and scans it infrequently.  It both detects corruption
1703 	  and prevents it from affecting the running system.
1704 
1705 	  It is, however, intended as a diagnostic tool; if repeatable
1706 	  BIOS-originated corruption always affects the same memory,
1707 	  you can use memmap= to prevent the kernel from using that
1708 	  memory.
1709 
1710 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1711 	bool "Set the default setting of memory_corruption_check"
1712 	depends on X86_CHECK_BIOS_CORRUPTION
1713 	default y
1714 	help
1715 	  Set whether the default state of memory_corruption_check is
1716 	  on or off.
1717 
1718 config MATH_EMULATION
1719 	bool
1720 	depends on MODIFY_LDT_SYSCALL
1721 	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1722 	help
1723 	  Linux can emulate a math coprocessor (used for floating point
1724 	  operations) if you don't have one. 486DX and Pentium processors have
1725 	  a math coprocessor built in, 486SX and 386 do not, unless you added
1726 	  a 487DX or 387, respectively. (The messages during boot time can
1727 	  give you some hints here ["man dmesg"].) Everyone needs either a
1728 	  coprocessor or this emulation.
1729 
1730 	  If you don't have a math coprocessor, you need to say Y here; if you
1731 	  say Y here even though you have a coprocessor, the coprocessor will
1732 	  be used nevertheless. (This behavior can be changed with the kernel
1733 	  command line option "no387", which comes handy if your coprocessor
1734 	  is broken. Try "man bootparam" or see the documentation of your boot
1735 	  loader (lilo or loadlin) about how to pass options to the kernel at
1736 	  boot time.) This means that it is a good idea to say Y here if you
1737 	  intend to use this kernel on different machines.
1738 
1739 	  More information about the internals of the Linux math coprocessor
1740 	  emulation can be found in <file:arch/x86/math-emu/README>.
1741 
1742 	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1743 	  kernel, it won't hurt.
1744 
1745 config MTRR
1746 	def_bool y
1747 	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1748 	help
1749 	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1750 	  the Memory Type Range Registers (MTRRs) may be used to control
1751 	  processor access to memory ranges. This is most useful if you have
1752 	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1753 	  allows bus write transfers to be combined into a larger transfer
1754 	  before bursting over the PCI/AGP bus. This can increase performance
1755 	  of image write operations 2.5 times or more. Saying Y here creates a
1756 	  /proc/mtrr file which may be used to manipulate your processor's
1757 	  MTRRs. Typically the X server should use this.
1758 
1759 	  This code has a reasonably generic interface so that similar
1760 	  control registers on other processors can be easily supported
1761 	  as well:
1762 
1763 	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1764 	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1765 	  these, the ARRs are used to emulate the MTRRs.
1766 	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1767 	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1768 	  write-combining. All of these processors are supported by this code
1769 	  and it makes sense to say Y here if you have one of them.
1770 
1771 	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1772 	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1773 	  can lead to all sorts of problems, so it's good to say Y here.
1774 
1775 	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1776 	  just add about 9 KB to your kernel.
1777 
1778 	  See <file:Documentation/x86/mtrr.rst> for more information.
1779 
1780 config MTRR_SANITIZER
1781 	def_bool y
1782 	prompt "MTRR cleanup support"
1783 	depends on MTRR
1784 	help
1785 	  Convert MTRR layout from continuous to discrete, so X drivers can
1786 	  add writeback entries.
1787 
1788 	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1789 	  The largest mtrr entry size for a continuous block can be set with
1790 	  mtrr_chunk_size.
1791 
1792 	  If unsure, say Y.
1793 
1794 config MTRR_SANITIZER_ENABLE_DEFAULT
1795 	int "MTRR cleanup enable value (0-1)"
1796 	range 0 1
1797 	default "0"
1798 	depends on MTRR_SANITIZER
1799 	help
1800 	  Enable mtrr cleanup default value
1801 
1802 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1803 	int "MTRR cleanup spare reg num (0-7)"
1804 	range 0 7
1805 	default "1"
1806 	depends on MTRR_SANITIZER
1807 	help
1808 	  mtrr cleanup spare entries default, it can be changed via
1809 	  mtrr_spare_reg_nr=N on the kernel command line.
1810 
1811 config X86_PAT
1812 	def_bool y
1813 	prompt "x86 PAT support" if EXPERT
1814 	depends on MTRR
1815 	help
1816 	  Use PAT attributes to setup page level cache control.
1817 
1818 	  PATs are the modern equivalents of MTRRs and are much more
1819 	  flexible than MTRRs.
1820 
1821 	  Say N here if you see bootup problems (boot crash, boot hang,
1822 	  spontaneous reboots) or a non-working video driver.
1823 
1824 	  If unsure, say Y.
1825 
1826 config ARCH_USES_PG_UNCACHED
1827 	def_bool y
1828 	depends on X86_PAT
1829 
1830 config X86_UMIP
1831 	def_bool y
1832 	prompt "User Mode Instruction Prevention" if EXPERT
1833 	help
1834 	  User Mode Instruction Prevention (UMIP) is a security feature in
1835 	  some x86 processors. If enabled, a general protection fault is
1836 	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1837 	  executed in user mode. These instructions unnecessarily expose
1838 	  information about the hardware state.
1839 
1840 	  The vast majority of applications do not use these instructions.
1841 	  For the very few that do, software emulation is provided in
1842 	  specific cases in protected and virtual-8086 modes. Emulated
1843 	  results are dummy.
1844 
1845 config CC_HAS_IBT
1846 	# GCC >= 9 and binutils >= 2.29
1847 	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1848 	# Clang/LLVM >= 14
1849 	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1850 	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1851 	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1852 		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1853 		  $(as-instr,endbr64)
1854 
1855 config X86_KERNEL_IBT
1856 	prompt "Indirect Branch Tracking"
1857 	bool
1858 	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1859 	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1860 	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1861 	select OBJTOOL
1862 	help
1863 	  Build the kernel with support for Indirect Branch Tracking, a
1864 	  hardware support course-grain forward-edge Control Flow Integrity
1865 	  protection. It enforces that all indirect calls must land on
1866 	  an ENDBR instruction, as such, the compiler will instrument the
1867 	  code with them to make this happen.
1868 
1869 	  In addition to building the kernel with IBT, seal all functions that
1870 	  are not indirect call targets, avoiding them ever becoming one.
1871 
1872 	  This requires LTO like objtool runs and will slow down the build. It
1873 	  does significantly reduce the number of ENDBR instructions in the
1874 	  kernel image.
1875 
1876 config X86_INTEL_MEMORY_PROTECTION_KEYS
1877 	prompt "Memory Protection Keys"
1878 	def_bool y
1879 	# Note: only available in 64-bit mode
1880 	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1881 	select ARCH_USES_HIGH_VMA_FLAGS
1882 	select ARCH_HAS_PKEYS
1883 	help
1884 	  Memory Protection Keys provides a mechanism for enforcing
1885 	  page-based protections, but without requiring modification of the
1886 	  page tables when an application changes protection domains.
1887 
1888 	  For details, see Documentation/core-api/protection-keys.rst
1889 
1890 	  If unsure, say y.
1891 
1892 choice
1893 	prompt "TSX enable mode"
1894 	depends on CPU_SUP_INTEL
1895 	default X86_INTEL_TSX_MODE_OFF
1896 	help
1897 	  Intel's TSX (Transactional Synchronization Extensions) feature
1898 	  allows to optimize locking protocols through lock elision which
1899 	  can lead to a noticeable performance boost.
1900 
1901 	  On the other hand it has been shown that TSX can be exploited
1902 	  to form side channel attacks (e.g. TAA) and chances are there
1903 	  will be more of those attacks discovered in the future.
1904 
1905 	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1906 	  might override this decision by tsx=on the command line parameter.
1907 	  Even with TSX enabled, the kernel will attempt to enable the best
1908 	  possible TAA mitigation setting depending on the microcode available
1909 	  for the particular machine.
1910 
1911 	  This option allows to set the default tsx mode between tsx=on, =off
1912 	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1913 	  details.
1914 
1915 	  Say off if not sure, auto if TSX is in use but it should be used on safe
1916 	  platforms or on if TSX is in use and the security aspect of tsx is not
1917 	  relevant.
1918 
1919 config X86_INTEL_TSX_MODE_OFF
1920 	bool "off"
1921 	help
1922 	  TSX is disabled if possible - equals to tsx=off command line parameter.
1923 
1924 config X86_INTEL_TSX_MODE_ON
1925 	bool "on"
1926 	help
1927 	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1928 	  line parameter.
1929 
1930 config X86_INTEL_TSX_MODE_AUTO
1931 	bool "auto"
1932 	help
1933 	  TSX is enabled on TSX capable HW that is believed to be safe against
1934 	  side channel attacks- equals the tsx=auto command line parameter.
1935 endchoice
1936 
1937 config X86_SGX
1938 	bool "Software Guard eXtensions (SGX)"
1939 	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1940 	depends on CRYPTO=y
1941 	depends on CRYPTO_SHA256=y
1942 	select SRCU
1943 	select MMU_NOTIFIER
1944 	select NUMA_KEEP_MEMINFO if NUMA
1945 	select XARRAY_MULTI
1946 	help
1947 	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1948 	  that can be used by applications to set aside private regions of code
1949 	  and data, referred to as enclaves. An enclave's private memory can
1950 	  only be accessed by code running within the enclave. Accesses from
1951 	  outside the enclave, including other enclaves, are disallowed by
1952 	  hardware.
1953 
1954 	  If unsure, say N.
1955 
1956 config EFI
1957 	bool "EFI runtime service support"
1958 	depends on ACPI
1959 	select UCS2_STRING
1960 	select EFI_RUNTIME_WRAPPERS
1961 	select ARCH_USE_MEMREMAP_PROT
1962 	help
1963 	  This enables the kernel to use EFI runtime services that are
1964 	  available (such as the EFI variable services).
1965 
1966 	  This option is only useful on systems that have EFI firmware.
1967 	  In addition, you should use the latest ELILO loader available
1968 	  at <http://elilo.sourceforge.net> in order to take advantage
1969 	  of EFI runtime services. However, even with this option, the
1970 	  resultant kernel should continue to boot on existing non-EFI
1971 	  platforms.
1972 
1973 config EFI_STUB
1974 	bool "EFI stub support"
1975 	depends on EFI
1976 	select RELOCATABLE
1977 	help
1978 	  This kernel feature allows a bzImage to be loaded directly
1979 	  by EFI firmware without the use of a bootloader.
1980 
1981 	  See Documentation/admin-guide/efi-stub.rst for more information.
1982 
1983 config EFI_MIXED
1984 	bool "EFI mixed-mode support"
1985 	depends on EFI_STUB && X86_64
1986 	help
1987 	  Enabling this feature allows a 64-bit kernel to be booted
1988 	  on a 32-bit firmware, provided that your CPU supports 64-bit
1989 	  mode.
1990 
1991 	  Note that it is not possible to boot a mixed-mode enabled
1992 	  kernel via the EFI boot stub - a bootloader that supports
1993 	  the EFI handover protocol must be used.
1994 
1995 	  If unsure, say N.
1996 
1997 source "kernel/Kconfig.hz"
1998 
1999 config KEXEC
2000 	bool "kexec system call"
2001 	select KEXEC_CORE
2002 	help
2003 	  kexec is a system call that implements the ability to shutdown your
2004 	  current kernel, and to start another kernel.  It is like a reboot
2005 	  but it is independent of the system firmware.   And like a reboot
2006 	  you can start any kernel with it, not just Linux.
2007 
2008 	  The name comes from the similarity to the exec system call.
2009 
2010 	  It is an ongoing process to be certain the hardware in a machine
2011 	  is properly shutdown, so do not be surprised if this code does not
2012 	  initially work for you.  As of this writing the exact hardware
2013 	  interface is strongly in flux, so no good recommendation can be
2014 	  made.
2015 
2016 config KEXEC_FILE
2017 	bool "kexec file based system call"
2018 	select KEXEC_CORE
2019 	select HAVE_IMA_KEXEC if IMA
2020 	depends on X86_64
2021 	depends on CRYPTO=y
2022 	depends on CRYPTO_SHA256=y
2023 	help
2024 	  This is new version of kexec system call. This system call is
2025 	  file based and takes file descriptors as system call argument
2026 	  for kernel and initramfs as opposed to list of segments as
2027 	  accepted by previous system call.
2028 
2029 config ARCH_HAS_KEXEC_PURGATORY
2030 	def_bool KEXEC_FILE
2031 
2032 config KEXEC_SIG
2033 	bool "Verify kernel signature during kexec_file_load() syscall"
2034 	depends on KEXEC_FILE
2035 	help
2036 
2037 	  This option makes the kexec_file_load() syscall check for a valid
2038 	  signature of the kernel image.  The image can still be loaded without
2039 	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2040 	  there's a signature that we can check, then it must be valid.
2041 
2042 	  In addition to this option, you need to enable signature
2043 	  verification for the corresponding kernel image type being
2044 	  loaded in order for this to work.
2045 
2046 config KEXEC_SIG_FORCE
2047 	bool "Require a valid signature in kexec_file_load() syscall"
2048 	depends on KEXEC_SIG
2049 	help
2050 	  This option makes kernel signature verification mandatory for
2051 	  the kexec_file_load() syscall.
2052 
2053 config KEXEC_BZIMAGE_VERIFY_SIG
2054 	bool "Enable bzImage signature verification support"
2055 	depends on KEXEC_SIG
2056 	depends on SIGNED_PE_FILE_VERIFICATION
2057 	select SYSTEM_TRUSTED_KEYRING
2058 	help
2059 	  Enable bzImage signature verification support.
2060 
2061 config CRASH_DUMP
2062 	bool "kernel crash dumps"
2063 	depends on X86_64 || (X86_32 && HIGHMEM)
2064 	help
2065 	  Generate crash dump after being started by kexec.
2066 	  This should be normally only set in special crash dump kernels
2067 	  which are loaded in the main kernel with kexec-tools into
2068 	  a specially reserved region and then later executed after
2069 	  a crash by kdump/kexec. The crash dump kernel must be compiled
2070 	  to a memory address not used by the main kernel or BIOS using
2071 	  PHYSICAL_START, or it must be built as a relocatable image
2072 	  (CONFIG_RELOCATABLE=y).
2073 	  For more details see Documentation/admin-guide/kdump/kdump.rst
2074 
2075 config KEXEC_JUMP
2076 	bool "kexec jump"
2077 	depends on KEXEC && HIBERNATION
2078 	help
2079 	  Jump between original kernel and kexeced kernel and invoke
2080 	  code in physical address mode via KEXEC
2081 
2082 config PHYSICAL_START
2083 	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2084 	default "0x1000000"
2085 	help
2086 	  This gives the physical address where the kernel is loaded.
2087 
2088 	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2089 	  bzImage will decompress itself to above physical address and
2090 	  run from there. Otherwise, bzImage will run from the address where
2091 	  it has been loaded by the boot loader and will ignore above physical
2092 	  address.
2093 
2094 	  In normal kdump cases one does not have to set/change this option
2095 	  as now bzImage can be compiled as a completely relocatable image
2096 	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2097 	  address. This option is mainly useful for the folks who don't want
2098 	  to use a bzImage for capturing the crash dump and want to use a
2099 	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2100 	  to be specifically compiled to run from a specific memory area
2101 	  (normally a reserved region) and this option comes handy.
2102 
2103 	  So if you are using bzImage for capturing the crash dump,
2104 	  leave the value here unchanged to 0x1000000 and set
2105 	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2106 	  for capturing the crash dump change this value to start of
2107 	  the reserved region.  In other words, it can be set based on
2108 	  the "X" value as specified in the "crashkernel=YM@XM"
2109 	  command line boot parameter passed to the panic-ed
2110 	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2111 	  for more details about crash dumps.
2112 
2113 	  Usage of bzImage for capturing the crash dump is recommended as
2114 	  one does not have to build two kernels. Same kernel can be used
2115 	  as production kernel and capture kernel. Above option should have
2116 	  gone away after relocatable bzImage support is introduced. But it
2117 	  is present because there are users out there who continue to use
2118 	  vmlinux for dump capture. This option should go away down the
2119 	  line.
2120 
2121 	  Don't change this unless you know what you are doing.
2122 
2123 config RELOCATABLE
2124 	bool "Build a relocatable kernel"
2125 	default y
2126 	help
2127 	  This builds a kernel image that retains relocation information
2128 	  so it can be loaded someplace besides the default 1MB.
2129 	  The relocations tend to make the kernel binary about 10% larger,
2130 	  but are discarded at runtime.
2131 
2132 	  One use is for the kexec on panic case where the recovery kernel
2133 	  must live at a different physical address than the primary
2134 	  kernel.
2135 
2136 	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2137 	  it has been loaded at and the compile time physical address
2138 	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2139 
2140 config RANDOMIZE_BASE
2141 	bool "Randomize the address of the kernel image (KASLR)"
2142 	depends on RELOCATABLE
2143 	default y
2144 	help
2145 	  In support of Kernel Address Space Layout Randomization (KASLR),
2146 	  this randomizes the physical address at which the kernel image
2147 	  is decompressed and the virtual address where the kernel
2148 	  image is mapped, as a security feature that deters exploit
2149 	  attempts relying on knowledge of the location of kernel
2150 	  code internals.
2151 
2152 	  On 64-bit, the kernel physical and virtual addresses are
2153 	  randomized separately. The physical address will be anywhere
2154 	  between 16MB and the top of physical memory (up to 64TB). The
2155 	  virtual address will be randomized from 16MB up to 1GB (9 bits
2156 	  of entropy). Note that this also reduces the memory space
2157 	  available to kernel modules from 1.5GB to 1GB.
2158 
2159 	  On 32-bit, the kernel physical and virtual addresses are
2160 	  randomized together. They will be randomized from 16MB up to
2161 	  512MB (8 bits of entropy).
2162 
2163 	  Entropy is generated using the RDRAND instruction if it is
2164 	  supported. If RDTSC is supported, its value is mixed into
2165 	  the entropy pool as well. If neither RDRAND nor RDTSC are
2166 	  supported, then entropy is read from the i8254 timer. The
2167 	  usable entropy is limited by the kernel being built using
2168 	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2169 	  minimum of 2MB. As a result, only 10 bits of entropy are
2170 	  theoretically possible, but the implementations are further
2171 	  limited due to memory layouts.
2172 
2173 	  If unsure, say Y.
2174 
2175 # Relocation on x86 needs some additional build support
2176 config X86_NEED_RELOCS
2177 	def_bool y
2178 	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2179 
2180 config PHYSICAL_ALIGN
2181 	hex "Alignment value to which kernel should be aligned"
2182 	default "0x200000"
2183 	range 0x2000 0x1000000 if X86_32
2184 	range 0x200000 0x1000000 if X86_64
2185 	help
2186 	  This value puts the alignment restrictions on physical address
2187 	  where kernel is loaded and run from. Kernel is compiled for an
2188 	  address which meets above alignment restriction.
2189 
2190 	  If bootloader loads the kernel at a non-aligned address and
2191 	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2192 	  address aligned to above value and run from there.
2193 
2194 	  If bootloader loads the kernel at a non-aligned address and
2195 	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2196 	  load address and decompress itself to the address it has been
2197 	  compiled for and run from there. The address for which kernel is
2198 	  compiled already meets above alignment restrictions. Hence the
2199 	  end result is that kernel runs from a physical address meeting
2200 	  above alignment restrictions.
2201 
2202 	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2203 	  this value must be a multiple of 0x200000.
2204 
2205 	  Don't change this unless you know what you are doing.
2206 
2207 config DYNAMIC_MEMORY_LAYOUT
2208 	bool
2209 	help
2210 	  This option makes base addresses of vmalloc and vmemmap as well as
2211 	  __PAGE_OFFSET movable during boot.
2212 
2213 config RANDOMIZE_MEMORY
2214 	bool "Randomize the kernel memory sections"
2215 	depends on X86_64
2216 	depends on RANDOMIZE_BASE
2217 	select DYNAMIC_MEMORY_LAYOUT
2218 	default RANDOMIZE_BASE
2219 	help
2220 	  Randomizes the base virtual address of kernel memory sections
2221 	  (physical memory mapping, vmalloc & vmemmap). This security feature
2222 	  makes exploits relying on predictable memory locations less reliable.
2223 
2224 	  The order of allocations remains unchanged. Entropy is generated in
2225 	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2226 	  configuration have in average 30,000 different possible virtual
2227 	  addresses for each memory section.
2228 
2229 	  If unsure, say Y.
2230 
2231 config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2232 	hex "Physical memory mapping padding" if EXPERT
2233 	depends on RANDOMIZE_MEMORY
2234 	default "0xa" if MEMORY_HOTPLUG
2235 	default "0x0"
2236 	range 0x1 0x40 if MEMORY_HOTPLUG
2237 	range 0x0 0x40
2238 	help
2239 	  Define the padding in terabytes added to the existing physical
2240 	  memory size during kernel memory randomization. It is useful
2241 	  for memory hotplug support but reduces the entropy available for
2242 	  address randomization.
2243 
2244 	  If unsure, leave at the default value.
2245 
2246 config HOTPLUG_CPU
2247 	def_bool y
2248 	depends on SMP
2249 
2250 config BOOTPARAM_HOTPLUG_CPU0
2251 	bool "Set default setting of cpu0_hotpluggable"
2252 	depends on HOTPLUG_CPU
2253 	help
2254 	  Set whether default state of cpu0_hotpluggable is on or off.
2255 
2256 	  Say Y here to enable CPU0 hotplug by default. If this switch
2257 	  is turned on, there is no need to give cpu0_hotplug kernel
2258 	  parameter and the CPU0 hotplug feature is enabled by default.
2259 
2260 	  Please note: there are two known CPU0 dependencies if you want
2261 	  to enable the CPU0 hotplug feature either by this switch or by
2262 	  cpu0_hotplug kernel parameter.
2263 
2264 	  First, resume from hibernate or suspend always starts from CPU0.
2265 	  So hibernate and suspend are prevented if CPU0 is offline.
2266 
2267 	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2268 	  offline if any interrupt can not migrate out of CPU0. There may
2269 	  be other CPU0 dependencies.
2270 
2271 	  Please make sure the dependencies are under your control before
2272 	  you enable this feature.
2273 
2274 	  Say N if you don't want to enable CPU0 hotplug feature by default.
2275 	  You still can enable the CPU0 hotplug feature at boot by kernel
2276 	  parameter cpu0_hotplug.
2277 
2278 config DEBUG_HOTPLUG_CPU0
2279 	def_bool n
2280 	prompt "Debug CPU0 hotplug"
2281 	depends on HOTPLUG_CPU
2282 	help
2283 	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2284 	  soon as possible and boots up userspace with CPU0 offlined. User
2285 	  can online CPU0 back after boot time.
2286 
2287 	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2288 	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2289 	  compilation or giving cpu0_hotplug kernel parameter at boot.
2290 
2291 	  If unsure, say N.
2292 
2293 config COMPAT_VDSO
2294 	def_bool n
2295 	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2296 	depends on COMPAT_32
2297 	help
2298 	  Certain buggy versions of glibc will crash if they are
2299 	  presented with a 32-bit vDSO that is not mapped at the address
2300 	  indicated in its segment table.
2301 
2302 	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2303 	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2304 	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2305 	  the only released version with the bug, but OpenSUSE 9
2306 	  contains a buggy "glibc 2.3.2".
2307 
2308 	  The symptom of the bug is that everything crashes on startup, saying:
2309 	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2310 
2311 	  Saying Y here changes the default value of the vdso32 boot
2312 	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2313 	  This works around the glibc bug but hurts performance.
2314 
2315 	  If unsure, say N: if you are compiling your own kernel, you
2316 	  are unlikely to be using a buggy version of glibc.
2317 
2318 choice
2319 	prompt "vsyscall table for legacy applications"
2320 	depends on X86_64
2321 	default LEGACY_VSYSCALL_XONLY
2322 	help
2323 	  Legacy user code that does not know how to find the vDSO expects
2324 	  to be able to issue three syscalls by calling fixed addresses in
2325 	  kernel space. Since this location is not randomized with ASLR,
2326 	  it can be used to assist security vulnerability exploitation.
2327 
2328 	  This setting can be changed at boot time via the kernel command
2329 	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2330 	  is deprecated and can only be enabled using the kernel command
2331 	  line.
2332 
2333 	  On a system with recent enough glibc (2.14 or newer) and no
2334 	  static binaries, you can say None without a performance penalty
2335 	  to improve security.
2336 
2337 	  If unsure, select "Emulate execution only".
2338 
2339 	config LEGACY_VSYSCALL_XONLY
2340 		bool "Emulate execution only"
2341 		help
2342 		  The kernel traps and emulates calls into the fixed vsyscall
2343 		  address mapping and does not allow reads.  This
2344 		  configuration is recommended when userspace might use the
2345 		  legacy vsyscall area but support for legacy binary
2346 		  instrumentation of legacy code is not needed.  It mitigates
2347 		  certain uses of the vsyscall area as an ASLR-bypassing
2348 		  buffer.
2349 
2350 	config LEGACY_VSYSCALL_NONE
2351 		bool "None"
2352 		help
2353 		  There will be no vsyscall mapping at all. This will
2354 		  eliminate any risk of ASLR bypass due to the vsyscall
2355 		  fixed address mapping. Attempts to use the vsyscalls
2356 		  will be reported to dmesg, so that either old or
2357 		  malicious userspace programs can be identified.
2358 
2359 endchoice
2360 
2361 config CMDLINE_BOOL
2362 	bool "Built-in kernel command line"
2363 	help
2364 	  Allow for specifying boot arguments to the kernel at
2365 	  build time.  On some systems (e.g. embedded ones), it is
2366 	  necessary or convenient to provide some or all of the
2367 	  kernel boot arguments with the kernel itself (that is,
2368 	  to not rely on the boot loader to provide them.)
2369 
2370 	  To compile command line arguments into the kernel,
2371 	  set this option to 'Y', then fill in the
2372 	  boot arguments in CONFIG_CMDLINE.
2373 
2374 	  Systems with fully functional boot loaders (i.e. non-embedded)
2375 	  should leave this option set to 'N'.
2376 
2377 config CMDLINE
2378 	string "Built-in kernel command string"
2379 	depends on CMDLINE_BOOL
2380 	default ""
2381 	help
2382 	  Enter arguments here that should be compiled into the kernel
2383 	  image and used at boot time.  If the boot loader provides a
2384 	  command line at boot time, it is appended to this string to
2385 	  form the full kernel command line, when the system boots.
2386 
2387 	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2388 	  change this behavior.
2389 
2390 	  In most cases, the command line (whether built-in or provided
2391 	  by the boot loader) should specify the device for the root
2392 	  file system.
2393 
2394 config CMDLINE_OVERRIDE
2395 	bool "Built-in command line overrides boot loader arguments"
2396 	depends on CMDLINE_BOOL && CMDLINE != ""
2397 	help
2398 	  Set this option to 'Y' to have the kernel ignore the boot loader
2399 	  command line, and use ONLY the built-in command line.
2400 
2401 	  This is used to work around broken boot loaders.  This should
2402 	  be set to 'N' under normal conditions.
2403 
2404 config MODIFY_LDT_SYSCALL
2405 	bool "Enable the LDT (local descriptor table)" if EXPERT
2406 	default y
2407 	help
2408 	  Linux can allow user programs to install a per-process x86
2409 	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2410 	  call.  This is required to run 16-bit or segmented code such as
2411 	  DOSEMU or some Wine programs.  It is also used by some very old
2412 	  threading libraries.
2413 
2414 	  Enabling this feature adds a small amount of overhead to
2415 	  context switches and increases the low-level kernel attack
2416 	  surface.  Disabling it removes the modify_ldt(2) system call.
2417 
2418 	  Saying 'N' here may make sense for embedded or server kernels.
2419 
2420 config STRICT_SIGALTSTACK_SIZE
2421 	bool "Enforce strict size checking for sigaltstack"
2422 	depends on DYNAMIC_SIGFRAME
2423 	help
2424 	  For historical reasons MINSIGSTKSZ is a constant which became
2425 	  already too small with AVX512 support. Add a mechanism to
2426 	  enforce strict checking of the sigaltstack size against the
2427 	  real size of the FPU frame. This option enables the check
2428 	  by default. It can also be controlled via the kernel command
2429 	  line option 'strict_sas_size' independent of this config
2430 	  switch. Enabling it might break existing applications which
2431 	  allocate a too small sigaltstack but 'work' because they
2432 	  never get a signal delivered.
2433 
2434 	  Say 'N' unless you want to really enforce this check.
2435 
2436 source "kernel/livepatch/Kconfig"
2437 
2438 endmenu
2439 
2440 config CC_HAS_SLS
2441 	def_bool $(cc-option,-mharden-sls=all)
2442 
2443 config CC_HAS_RETURN_THUNK
2444 	def_bool $(cc-option,-mfunction-return=thunk-extern)
2445 
2446 menuconfig SPECULATION_MITIGATIONS
2447 	bool "Mitigations for speculative execution vulnerabilities"
2448 	default y
2449 	help
2450 	  Say Y here to enable options which enable mitigations for
2451 	  speculative execution hardware vulnerabilities.
2452 
2453 	  If you say N, all mitigations will be disabled. You really
2454 	  should know what you are doing to say so.
2455 
2456 if SPECULATION_MITIGATIONS
2457 
2458 config PAGE_TABLE_ISOLATION
2459 	bool "Remove the kernel mapping in user mode"
2460 	default y
2461 	depends on (X86_64 || X86_PAE)
2462 	help
2463 	  This feature reduces the number of hardware side channels by
2464 	  ensuring that the majority of kernel addresses are not mapped
2465 	  into userspace.
2466 
2467 	  See Documentation/x86/pti.rst for more details.
2468 
2469 config RETPOLINE
2470 	bool "Avoid speculative indirect branches in kernel"
2471 	select OBJTOOL if HAVE_OBJTOOL
2472 	default y
2473 	help
2474 	  Compile kernel with the retpoline compiler options to guard against
2475 	  kernel-to-user data leaks by avoiding speculative indirect
2476 	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2477 	  support for full protection. The kernel may run slower.
2478 
2479 config RETHUNK
2480 	bool "Enable return-thunks"
2481 	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2482 	select OBJTOOL if HAVE_OBJTOOL
2483 	default y if X86_64
2484 	help
2485 	  Compile the kernel with the return-thunks compiler option to guard
2486 	  against kernel-to-user data leaks by avoiding return speculation.
2487 	  Requires a compiler with -mfunction-return=thunk-extern
2488 	  support for full protection. The kernel may run slower.
2489 
2490 config CPU_UNRET_ENTRY
2491 	bool "Enable UNRET on kernel entry"
2492 	depends on CPU_SUP_AMD && RETHUNK && X86_64
2493 	default y
2494 	help
2495 	  Compile the kernel with support for the retbleed=unret mitigation.
2496 
2497 config CPU_IBPB_ENTRY
2498 	bool "Enable IBPB on kernel entry"
2499 	depends on CPU_SUP_AMD && X86_64
2500 	default y
2501 	help
2502 	  Compile the kernel with support for the retbleed=ibpb mitigation.
2503 
2504 config CPU_IBRS_ENTRY
2505 	bool "Enable IBRS on kernel entry"
2506 	depends on CPU_SUP_INTEL && X86_64
2507 	default y
2508 	help
2509 	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2510 	  This mitigates both spectre_v2 and retbleed at great cost to
2511 	  performance.
2512 
2513 config SLS
2514 	bool "Mitigate Straight-Line-Speculation"
2515 	depends on CC_HAS_SLS && X86_64
2516 	select OBJTOOL if HAVE_OBJTOOL
2517 	default n
2518 	help
2519 	  Compile the kernel with straight-line-speculation options to guard
2520 	  against straight line speculation. The kernel image might be slightly
2521 	  larger.
2522 
2523 endif
2524 
2525 config ARCH_HAS_ADD_PAGES
2526 	def_bool y
2527 	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2528 
2529 config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2530 	def_bool y
2531 
2532 menu "Power management and ACPI options"
2533 
2534 config ARCH_HIBERNATION_HEADER
2535 	def_bool y
2536 	depends on HIBERNATION
2537 
2538 source "kernel/power/Kconfig"
2539 
2540 source "drivers/acpi/Kconfig"
2541 
2542 config X86_APM_BOOT
2543 	def_bool y
2544 	depends on APM
2545 
2546 menuconfig APM
2547 	tristate "APM (Advanced Power Management) BIOS support"
2548 	depends on X86_32 && PM_SLEEP
2549 	help
2550 	  APM is a BIOS specification for saving power using several different
2551 	  techniques. This is mostly useful for battery powered laptops with
2552 	  APM compliant BIOSes. If you say Y here, the system time will be
2553 	  reset after a RESUME operation, the /proc/apm device will provide
2554 	  battery status information, and user-space programs will receive
2555 	  notification of APM "events" (e.g. battery status change).
2556 
2557 	  If you select "Y" here, you can disable actual use of the APM
2558 	  BIOS by passing the "apm=off" option to the kernel at boot time.
2559 
2560 	  Note that the APM support is almost completely disabled for
2561 	  machines with more than one CPU.
2562 
2563 	  In order to use APM, you will need supporting software. For location
2564 	  and more information, read <file:Documentation/power/apm-acpi.rst>
2565 	  and the Battery Powered Linux mini-HOWTO, available from
2566 	  <http://www.tldp.org/docs.html#howto>.
2567 
2568 	  This driver does not spin down disk drives (see the hdparm(8)
2569 	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2570 	  VESA-compliant "green" monitors.
2571 
2572 	  This driver does not support the TI 4000M TravelMate and the ACER
2573 	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2574 	  desktop machines also don't have compliant BIOSes, and this driver
2575 	  may cause those machines to panic during the boot phase.
2576 
2577 	  Generally, if you don't have a battery in your machine, there isn't
2578 	  much point in using this driver and you should say N. If you get
2579 	  random kernel OOPSes or reboots that don't seem to be related to
2580 	  anything, try disabling/enabling this option (or disabling/enabling
2581 	  APM in your BIOS).
2582 
2583 	  Some other things you should try when experiencing seemingly random,
2584 	  "weird" problems:
2585 
2586 	  1) make sure that you have enough swap space and that it is
2587 	  enabled.
2588 	  2) pass the "idle=poll" option to the kernel
2589 	  3) switch on floating point emulation in the kernel and pass
2590 	  the "no387" option to the kernel
2591 	  4) pass the "floppy=nodma" option to the kernel
2592 	  5) pass the "mem=4M" option to the kernel (thereby disabling
2593 	  all but the first 4 MB of RAM)
2594 	  6) make sure that the CPU is not over clocked.
2595 	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2596 	  8) disable the cache from your BIOS settings
2597 	  9) install a fan for the video card or exchange video RAM
2598 	  10) install a better fan for the CPU
2599 	  11) exchange RAM chips
2600 	  12) exchange the motherboard.
2601 
2602 	  To compile this driver as a module, choose M here: the
2603 	  module will be called apm.
2604 
2605 if APM
2606 
2607 config APM_IGNORE_USER_SUSPEND
2608 	bool "Ignore USER SUSPEND"
2609 	help
2610 	  This option will ignore USER SUSPEND requests. On machines with a
2611 	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2612 	  series notebooks, it is necessary to say Y because of a BIOS bug.
2613 
2614 config APM_DO_ENABLE
2615 	bool "Enable PM at boot time"
2616 	help
2617 	  Enable APM features at boot time. From page 36 of the APM BIOS
2618 	  specification: "When disabled, the APM BIOS does not automatically
2619 	  power manage devices, enter the Standby State, enter the Suspend
2620 	  State, or take power saving steps in response to CPU Idle calls."
2621 	  This driver will make CPU Idle calls when Linux is idle (unless this
2622 	  feature is turned off -- see "Do CPU IDLE calls", below). This
2623 	  should always save battery power, but more complicated APM features
2624 	  will be dependent on your BIOS implementation. You may need to turn
2625 	  this option off if your computer hangs at boot time when using APM
2626 	  support, or if it beeps continuously instead of suspending. Turn
2627 	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2628 	  T400CDT. This is off by default since most machines do fine without
2629 	  this feature.
2630 
2631 config APM_CPU_IDLE
2632 	depends on CPU_IDLE
2633 	bool "Make CPU Idle calls when idle"
2634 	help
2635 	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2636 	  On some machines, this can activate improved power savings, such as
2637 	  a slowed CPU clock rate, when the machine is idle. These idle calls
2638 	  are made after the idle loop has run for some length of time (e.g.,
2639 	  333 mS). On some machines, this will cause a hang at boot time or
2640 	  whenever the CPU becomes idle. (On machines with more than one CPU,
2641 	  this option does nothing.)
2642 
2643 config APM_DISPLAY_BLANK
2644 	bool "Enable console blanking using APM"
2645 	help
2646 	  Enable console blanking using the APM. Some laptops can use this to
2647 	  turn off the LCD backlight when the screen blanker of the Linux
2648 	  virtual console blanks the screen. Note that this is only used by
2649 	  the virtual console screen blanker, and won't turn off the backlight
2650 	  when using the X Window system. This also doesn't have anything to
2651 	  do with your VESA-compliant power-saving monitor. Further, this
2652 	  option doesn't work for all laptops -- it might not turn off your
2653 	  backlight at all, or it might print a lot of errors to the console,
2654 	  especially if you are using gpm.
2655 
2656 config APM_ALLOW_INTS
2657 	bool "Allow interrupts during APM BIOS calls"
2658 	help
2659 	  Normally we disable external interrupts while we are making calls to
2660 	  the APM BIOS as a measure to lessen the effects of a badly behaving
2661 	  BIOS implementation.  The BIOS should reenable interrupts if it
2662 	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2663 	  many of the newer IBM Thinkpads.  If you experience hangs when you
2664 	  suspend, try setting this to Y.  Otherwise, say N.
2665 
2666 endif # APM
2667 
2668 source "drivers/cpufreq/Kconfig"
2669 
2670 source "drivers/cpuidle/Kconfig"
2671 
2672 source "drivers/idle/Kconfig"
2673 
2674 endmenu
2675 
2676 menu "Bus options (PCI etc.)"
2677 
2678 choice
2679 	prompt "PCI access mode"
2680 	depends on X86_32 && PCI
2681 	default PCI_GOANY
2682 	help
2683 	  On PCI systems, the BIOS can be used to detect the PCI devices and
2684 	  determine their configuration. However, some old PCI motherboards
2685 	  have BIOS bugs and may crash if this is done. Also, some embedded
2686 	  PCI-based systems don't have any BIOS at all. Linux can also try to
2687 	  detect the PCI hardware directly without using the BIOS.
2688 
2689 	  With this option, you can specify how Linux should detect the
2690 	  PCI devices. If you choose "BIOS", the BIOS will be used,
2691 	  if you choose "Direct", the BIOS won't be used, and if you
2692 	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2693 	  If you choose "Any", the kernel will try MMCONFIG, then the
2694 	  direct access method and falls back to the BIOS if that doesn't
2695 	  work. If unsure, go with the default, which is "Any".
2696 
2697 config PCI_GOBIOS
2698 	bool "BIOS"
2699 
2700 config PCI_GOMMCONFIG
2701 	bool "MMConfig"
2702 
2703 config PCI_GODIRECT
2704 	bool "Direct"
2705 
2706 config PCI_GOOLPC
2707 	bool "OLPC XO-1"
2708 	depends on OLPC
2709 
2710 config PCI_GOANY
2711 	bool "Any"
2712 
2713 endchoice
2714 
2715 config PCI_BIOS
2716 	def_bool y
2717 	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2718 
2719 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2720 config PCI_DIRECT
2721 	def_bool y
2722 	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2723 
2724 config PCI_MMCONFIG
2725 	bool "Support mmconfig PCI config space access" if X86_64
2726 	default y
2727 	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2728 	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2729 
2730 config PCI_OLPC
2731 	def_bool y
2732 	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2733 
2734 config PCI_XEN
2735 	def_bool y
2736 	depends on PCI && XEN
2737 
2738 config MMCONF_FAM10H
2739 	def_bool y
2740 	depends on X86_64 && PCI_MMCONFIG && ACPI
2741 
2742 config PCI_CNB20LE_QUIRK
2743 	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2744 	depends on PCI
2745 	help
2746 	  Read the PCI windows out of the CNB20LE host bridge. This allows
2747 	  PCI hotplug to work on systems with the CNB20LE chipset which do
2748 	  not have ACPI.
2749 
2750 	  There's no public spec for this chipset, and this functionality
2751 	  is known to be incomplete.
2752 
2753 	  You should say N unless you know you need this.
2754 
2755 config ISA_BUS
2756 	bool "ISA bus support on modern systems" if EXPERT
2757 	help
2758 	  Expose ISA bus device drivers and options available for selection and
2759 	  configuration. Enable this option if your target machine has an ISA
2760 	  bus. ISA is an older system, displaced by PCI and newer bus
2761 	  architectures -- if your target machine is modern, it probably does
2762 	  not have an ISA bus.
2763 
2764 	  If unsure, say N.
2765 
2766 # x86_64 have no ISA slots, but can have ISA-style DMA.
2767 config ISA_DMA_API
2768 	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2769 	default y
2770 	help
2771 	  Enables ISA-style DMA support for devices requiring such controllers.
2772 	  If unsure, say Y.
2773 
2774 if X86_32
2775 
2776 config ISA
2777 	bool "ISA support"
2778 	help
2779 	  Find out whether you have ISA slots on your motherboard.  ISA is the
2780 	  name of a bus system, i.e. the way the CPU talks to the other stuff
2781 	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2782 	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2783 	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2784 
2785 config SCx200
2786 	tristate "NatSemi SCx200 support"
2787 	help
2788 	  This provides basic support for National Semiconductor's
2789 	  (now AMD's) Geode processors.  The driver probes for the
2790 	  PCI-IDs of several on-chip devices, so its a good dependency
2791 	  for other scx200_* drivers.
2792 
2793 	  If compiled as a module, the driver is named scx200.
2794 
2795 config SCx200HR_TIMER
2796 	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2797 	depends on SCx200
2798 	default y
2799 	help
2800 	  This driver provides a clocksource built upon the on-chip
2801 	  27MHz high-resolution timer.  Its also a workaround for
2802 	  NSC Geode SC-1100's buggy TSC, which loses time when the
2803 	  processor goes idle (as is done by the scheduler).  The
2804 	  other workaround is idle=poll boot option.
2805 
2806 config OLPC
2807 	bool "One Laptop Per Child support"
2808 	depends on !X86_PAE
2809 	select GPIOLIB
2810 	select OF
2811 	select OF_PROMTREE
2812 	select IRQ_DOMAIN
2813 	select OLPC_EC
2814 	help
2815 	  Add support for detecting the unique features of the OLPC
2816 	  XO hardware.
2817 
2818 config OLPC_XO1_PM
2819 	bool "OLPC XO-1 Power Management"
2820 	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2821 	help
2822 	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2823 
2824 config OLPC_XO1_RTC
2825 	bool "OLPC XO-1 Real Time Clock"
2826 	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2827 	help
2828 	  Add support for the XO-1 real time clock, which can be used as a
2829 	  programmable wakeup source.
2830 
2831 config OLPC_XO1_SCI
2832 	bool "OLPC XO-1 SCI extras"
2833 	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2834 	depends on INPUT=y
2835 	select POWER_SUPPLY
2836 	help
2837 	  Add support for SCI-based features of the OLPC XO-1 laptop:
2838 	   - EC-driven system wakeups
2839 	   - Power button
2840 	   - Ebook switch
2841 	   - Lid switch
2842 	   - AC adapter status updates
2843 	   - Battery status updates
2844 
2845 config OLPC_XO15_SCI
2846 	bool "OLPC XO-1.5 SCI extras"
2847 	depends on OLPC && ACPI
2848 	select POWER_SUPPLY
2849 	help
2850 	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2851 	   - EC-driven system wakeups
2852 	   - AC adapter status updates
2853 	   - Battery status updates
2854 
2855 config ALIX
2856 	bool "PCEngines ALIX System Support (LED setup)"
2857 	select GPIOLIB
2858 	help
2859 	  This option enables system support for the PCEngines ALIX.
2860 	  At present this just sets up LEDs for GPIO control on
2861 	  ALIX2/3/6 boards.  However, other system specific setup should
2862 	  get added here.
2863 
2864 	  Note: You must still enable the drivers for GPIO and LED support
2865 	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2866 
2867 	  Note: You have to set alix.force=1 for boards with Award BIOS.
2868 
2869 config NET5501
2870 	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2871 	select GPIOLIB
2872 	help
2873 	  This option enables system support for the Soekris Engineering net5501.
2874 
2875 config GEOS
2876 	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2877 	select GPIOLIB
2878 	depends on DMI
2879 	help
2880 	  This option enables system support for the Traverse Technologies GEOS.
2881 
2882 config TS5500
2883 	bool "Technologic Systems TS-5500 platform support"
2884 	depends on MELAN
2885 	select CHECK_SIGNATURE
2886 	select NEW_LEDS
2887 	select LEDS_CLASS
2888 	help
2889 	  This option enables system support for the Technologic Systems TS-5500.
2890 
2891 endif # X86_32
2892 
2893 config AMD_NB
2894 	def_bool y
2895 	depends on CPU_SUP_AMD && PCI
2896 
2897 endmenu
2898 
2899 menu "Binary Emulations"
2900 
2901 config IA32_EMULATION
2902 	bool "IA32 Emulation"
2903 	depends on X86_64
2904 	select ARCH_WANT_OLD_COMPAT_IPC
2905 	select BINFMT_ELF
2906 	select COMPAT_OLD_SIGACTION
2907 	help
2908 	  Include code to run legacy 32-bit programs under a
2909 	  64-bit kernel. You should likely turn this on, unless you're
2910 	  100% sure that you don't have any 32-bit programs left.
2911 
2912 config X86_X32_ABI
2913 	bool "x32 ABI for 64-bit mode"
2914 	depends on X86_64
2915 	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2916 	# compressed debug sections to x86_x32 properly:
2917 	# https://github.com/ClangBuiltLinux/linux/issues/514
2918 	# https://github.com/ClangBuiltLinux/linux/issues/1141
2919 	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2920 	help
2921 	  Include code to run binaries for the x32 native 32-bit ABI
2922 	  for 64-bit processors.  An x32 process gets access to the
2923 	  full 64-bit register file and wide data path while leaving
2924 	  pointers at 32 bits for smaller memory footprint.
2925 
2926 config COMPAT_32
2927 	def_bool y
2928 	depends on IA32_EMULATION || X86_32
2929 	select HAVE_UID16
2930 	select OLD_SIGSUSPEND3
2931 
2932 config COMPAT
2933 	def_bool y
2934 	depends on IA32_EMULATION || X86_X32_ABI
2935 
2936 config COMPAT_FOR_U64_ALIGNMENT
2937 	def_bool y
2938 	depends on COMPAT
2939 
2940 endmenu
2941 
2942 config HAVE_ATOMIC_IOMAP
2943 	def_bool y
2944 	depends on X86_32
2945 
2946 source "arch/x86/kvm/Kconfig"
2947 
2948 source "arch/x86/Kconfig.assembler"
2949