xref: /openbmc/linux/arch/x86/Kconfig (revision 6774def6)
1# Select 32 or 64 bit
2config 64BIT
3	bool "64-bit kernel" if ARCH = "x86"
4	default ARCH != "i386"
5	---help---
6	  Say yes to build a 64-bit kernel - formerly known as x86_64
7	  Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
10	def_bool y
11	depends on !64BIT
12	select CLKSRC_I8253
13	select HAVE_UID16
14
15config X86_64
16	def_bool y
17	depends on 64BIT
18	select X86_DEV_DMA_OPS
19	select ARCH_USE_CMPXCHG_LOCKREF
20
21### Arch settings
22config X86
23	def_bool y
24	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
25	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26	select ARCH_HAS_FAST_MULTIPLIER
27	select ARCH_MIGHT_HAVE_PC_PARPORT
28	select ARCH_MIGHT_HAVE_PC_SERIO
29	select HAVE_AOUT if X86_32
30	select HAVE_UNSTABLE_SCHED_CLOCK
31	select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
32	select ARCH_SUPPORTS_INT128 if X86_64
33	select HAVE_IDE
34	select HAVE_OPROFILE
35	select HAVE_PCSPKR_PLATFORM
36	select HAVE_PERF_EVENTS
37	select HAVE_IOREMAP_PROT
38	select HAVE_KPROBES
39	select HAVE_MEMBLOCK
40	select HAVE_MEMBLOCK_NODE_MAP
41	select ARCH_DISCARD_MEMBLOCK
42	select ARCH_WANT_OPTIONAL_GPIOLIB
43	select ARCH_WANT_FRAME_POINTERS
44	select HAVE_DMA_ATTRS
45	select HAVE_DMA_CONTIGUOUS
46	select HAVE_KRETPROBES
47	select GENERIC_EARLY_IOREMAP
48	select HAVE_OPTPROBES
49	select HAVE_KPROBES_ON_FTRACE
50	select HAVE_FTRACE_MCOUNT_RECORD
51	select HAVE_FENTRY if X86_64
52	select HAVE_C_RECORDMCOUNT
53	select HAVE_DYNAMIC_FTRACE
54	select HAVE_DYNAMIC_FTRACE_WITH_REGS
55	select HAVE_FUNCTION_TRACER
56	select HAVE_FUNCTION_GRAPH_TRACER
57	select HAVE_FUNCTION_GRAPH_FP_TEST
58	select HAVE_SYSCALL_TRACEPOINTS
59	select SYSCTL_EXCEPTION_TRACE
60	select HAVE_KVM
61	select HAVE_ARCH_KGDB
62	select HAVE_ARCH_TRACEHOOK
63	select HAVE_GENERIC_DMA_COHERENT if X86_32
64	select HAVE_EFFICIENT_UNALIGNED_ACCESS
65	select USER_STACKTRACE_SUPPORT
66	select HAVE_REGS_AND_STACK_ACCESS_API
67	select HAVE_DMA_API_DEBUG
68	select HAVE_KERNEL_GZIP
69	select HAVE_KERNEL_BZIP2
70	select HAVE_KERNEL_LZMA
71	select HAVE_KERNEL_XZ
72	select HAVE_KERNEL_LZO
73	select HAVE_KERNEL_LZ4
74	select HAVE_HW_BREAKPOINT
75	select HAVE_MIXED_BREAKPOINTS_REGS
76	select PERF_EVENTS
77	select HAVE_PERF_EVENTS_NMI
78	select HAVE_PERF_REGS
79	select HAVE_PERF_USER_STACK_DUMP
80	select HAVE_DEBUG_KMEMLEAK
81	select ANON_INODES
82	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83	select HAVE_CMPXCHG_LOCAL
84	select HAVE_CMPXCHG_DOUBLE
85	select HAVE_ARCH_KMEMCHECK
86	select HAVE_USER_RETURN_NOTIFIER
87	select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88	select HAVE_ARCH_JUMP_LABEL
89	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90	select SPARSE_IRQ
91	select GENERIC_FIND_FIRST_BIT
92	select GENERIC_IRQ_PROBE
93	select GENERIC_PENDING_IRQ if SMP
94	select GENERIC_IRQ_SHOW
95	select GENERIC_CLOCKEVENTS_MIN_ADJUST
96	select IRQ_FORCED_THREADING
97	select HAVE_BPF_JIT if X86_64
98	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99	select ARCH_HAS_SG_CHAIN
100	select CLKEVT_I8253
101	select ARCH_HAVE_NMI_SAFE_CMPXCHG
102	select GENERIC_IOMAP
103	select DCACHE_WORD_ACCESS
104	select GENERIC_SMP_IDLE_THREAD
105	select ARCH_WANT_IPC_PARSE_VERSION if X86_32
106	select HAVE_ARCH_SECCOMP_FILTER
107	select BUILDTIME_EXTABLE_SORT
108	select GENERIC_CMOS_UPDATE
109	select HAVE_ARCH_SOFT_DIRTY if X86_64
110	select CLOCKSOURCE_WATCHDOG
111	select GENERIC_CLOCKEVENTS
112	select ARCH_CLOCKSOURCE_DATA
113	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
114	select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
115	select GENERIC_TIME_VSYSCALL
116	select GENERIC_STRNCPY_FROM_USER
117	select GENERIC_STRNLEN_USER
118	select HAVE_CONTEXT_TRACKING if X86_64
119	select HAVE_IRQ_TIME_ACCOUNTING
120	select VIRT_TO_BUS
121	select MODULES_USE_ELF_REL if X86_32
122	select MODULES_USE_ELF_RELA if X86_64
123	select CLONE_BACKWARDS if X86_32
124	select ARCH_USE_BUILTIN_BSWAP
125	select ARCH_USE_QUEUE_RWLOCK
126	select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
127	select OLD_SIGACTION if X86_32
128	select COMPAT_OLD_SIGACTION if IA32_EMULATION
129	select RTC_LIB
130	select HAVE_DEBUG_STACKOVERFLOW
131	select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
132	select HAVE_CC_STACKPROTECTOR
133	select GENERIC_CPU_AUTOPROBE
134	select HAVE_ARCH_AUDITSYSCALL
135	select ARCH_SUPPORTS_ATOMIC_RMW
136	select HAVE_ACPI_APEI if ACPI
137	select HAVE_ACPI_APEI_NMI if ACPI
138	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
139	select X86_FEATURE_NAMES if PROC_FS
140
141config INSTRUCTION_DECODER
142	def_bool y
143	depends on KPROBES || PERF_EVENTS || UPROBES
144
145config PERF_EVENTS_INTEL_UNCORE
146	def_bool y
147	depends on PERF_EVENTS && SUP_SUP_INTEL && PCI
148
149config OUTPUT_FORMAT
150	string
151	default "elf32-i386" if X86_32
152	default "elf64-x86-64" if X86_64
153
154config ARCH_DEFCONFIG
155	string
156	default "arch/x86/configs/i386_defconfig" if X86_32
157	default "arch/x86/configs/x86_64_defconfig" if X86_64
158
159config LOCKDEP_SUPPORT
160	def_bool y
161
162config STACKTRACE_SUPPORT
163	def_bool y
164
165config HAVE_LATENCYTOP_SUPPORT
166	def_bool y
167
168config MMU
169	def_bool y
170
171config SBUS
172	bool
173
174config NEED_DMA_MAP_STATE
175	def_bool y
176	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
177
178config NEED_SG_DMA_LENGTH
179	def_bool y
180
181config GENERIC_ISA_DMA
182	def_bool y
183	depends on ISA_DMA_API
184
185config GENERIC_BUG
186	def_bool y
187	depends on BUG
188	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
189
190config GENERIC_BUG_RELATIVE_POINTERS
191	bool
192
193config GENERIC_HWEIGHT
194	def_bool y
195
196config ARCH_MAY_HAVE_PC_FDC
197	def_bool y
198	depends on ISA_DMA_API
199
200config RWSEM_XCHGADD_ALGORITHM
201	def_bool y
202
203config GENERIC_CALIBRATE_DELAY
204	def_bool y
205
206config ARCH_HAS_CPU_RELAX
207	def_bool y
208
209config ARCH_HAS_CACHE_LINE_SIZE
210	def_bool y
211
212config HAVE_SETUP_PER_CPU_AREA
213	def_bool y
214
215config NEED_PER_CPU_EMBED_FIRST_CHUNK
216	def_bool y
217
218config NEED_PER_CPU_PAGE_FIRST_CHUNK
219	def_bool y
220
221config ARCH_HIBERNATION_POSSIBLE
222	def_bool y
223
224config ARCH_SUSPEND_POSSIBLE
225	def_bool y
226
227config ARCH_WANT_HUGE_PMD_SHARE
228	def_bool y
229
230config ARCH_WANT_GENERAL_HUGETLB
231	def_bool y
232
233config ZONE_DMA32
234	bool
235	default X86_64
236
237config AUDIT_ARCH
238	bool
239	default X86_64
240
241config ARCH_SUPPORTS_OPTIMIZED_INLINING
242	def_bool y
243
244config ARCH_SUPPORTS_DEBUG_PAGEALLOC
245	def_bool y
246
247config HAVE_INTEL_TXT
248	def_bool y
249	depends on INTEL_IOMMU && ACPI
250
251config X86_32_SMP
252	def_bool y
253	depends on X86_32 && SMP
254
255config X86_64_SMP
256	def_bool y
257	depends on X86_64 && SMP
258
259config X86_HT
260	def_bool y
261	depends on SMP
262
263config X86_32_LAZY_GS
264	def_bool y
265	depends on X86_32 && !CC_STACKPROTECTOR
266
267config ARCH_HWEIGHT_CFLAGS
268	string
269	default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
270	default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
271
272config ARCH_SUPPORTS_UPROBES
273	def_bool y
274
275config FIX_EARLYCON_MEM
276	def_bool y
277
278source "init/Kconfig"
279source "kernel/Kconfig.freezer"
280
281menu "Processor type and features"
282
283config ZONE_DMA
284	bool "DMA memory allocation support" if EXPERT
285	default y
286	help
287	  DMA memory allocation support allows devices with less than 32-bit
288	  addressing to allocate within the first 16MB of address space.
289	  Disable if no such devices will be used.
290
291	  If unsure, say Y.
292
293config SMP
294	bool "Symmetric multi-processing support"
295	---help---
296	  This enables support for systems with more than one CPU. If you have
297	  a system with only one CPU, say N. If you have a system with more
298	  than one CPU, say Y.
299
300	  If you say N here, the kernel will run on uni- and multiprocessor
301	  machines, but will use only one CPU of a multiprocessor machine. If
302	  you say Y here, the kernel will run on many, but not all,
303	  uniprocessor machines. On a uniprocessor machine, the kernel
304	  will run faster if you say N here.
305
306	  Note that if you say Y here and choose architecture "586" or
307	  "Pentium" under "Processor family", the kernel will not work on 486
308	  architectures. Similarly, multiprocessor kernels for the "PPro"
309	  architecture may not work on all Pentium based boards.
310
311	  People using multiprocessor machines who say Y here should also say
312	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
313	  Management" code will be disabled if you say Y here.
314
315	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
316	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
317	  <http://www.tldp.org/docs.html#howto>.
318
319	  If you don't know what to do here, say N.
320
321config X86_FEATURE_NAMES
322	bool "Processor feature human-readable names" if EMBEDDED
323	default y
324	---help---
325	  This option compiles in a table of x86 feature bits and corresponding
326	  names.  This is required to support /proc/cpuinfo and a few kernel
327	  messages.  You can disable this to save space, at the expense of
328	  making those few kernel messages show numeric feature bits instead.
329
330	  If in doubt, say Y.
331
332config X86_X2APIC
333	bool "Support x2apic"
334	depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
335	---help---
336	  This enables x2apic support on CPUs that have this feature.
337
338	  This allows 32-bit apic IDs (so it can support very large systems),
339	  and accesses the local apic via MSRs not via mmio.
340
341	  If you don't know what to do here, say N.
342
343config X86_MPPARSE
344	bool "Enable MPS table" if ACPI || SFI
345	default y
346	depends on X86_LOCAL_APIC
347	---help---
348	  For old smp systems that do not have proper acpi support. Newer systems
349	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
350
351config X86_BIGSMP
352	bool "Support for big SMP systems with more than 8 CPUs"
353	depends on X86_32 && SMP
354	---help---
355	  This option is needed for the systems that have more than 8 CPUs
356
357config GOLDFISH
358       def_bool y
359       depends on X86_GOLDFISH
360
361if X86_32
362config X86_EXTENDED_PLATFORM
363	bool "Support for extended (non-PC) x86 platforms"
364	default y
365	---help---
366	  If you disable this option then the kernel will only support
367	  standard PC platforms. (which covers the vast majority of
368	  systems out there.)
369
370	  If you enable this option then you'll be able to select support
371	  for the following (non-PC) 32 bit x86 platforms:
372		Goldfish (Android emulator)
373		AMD Elan
374		RDC R-321x SoC
375		SGI 320/540 (Visual Workstation)
376		STA2X11-based (e.g. Northville)
377		Moorestown MID devices
378
379	  If you have one of these systems, or if you want to build a
380	  generic distribution kernel, say Y here - otherwise say N.
381endif
382
383if X86_64
384config X86_EXTENDED_PLATFORM
385	bool "Support for extended (non-PC) x86 platforms"
386	default y
387	---help---
388	  If you disable this option then the kernel will only support
389	  standard PC platforms. (which covers the vast majority of
390	  systems out there.)
391
392	  If you enable this option then you'll be able to select support
393	  for the following (non-PC) 64 bit x86 platforms:
394		Numascale NumaChip
395		ScaleMP vSMP
396		SGI Ultraviolet
397
398	  If you have one of these systems, or if you want to build a
399	  generic distribution kernel, say Y here - otherwise say N.
400endif
401# This is an alphabetically sorted list of 64 bit extended platforms
402# Please maintain the alphabetic order if and when there are additions
403config X86_NUMACHIP
404	bool "Numascale NumaChip"
405	depends on X86_64
406	depends on X86_EXTENDED_PLATFORM
407	depends on NUMA
408	depends on SMP
409	depends on X86_X2APIC
410	depends on PCI_MMCONFIG
411	---help---
412	  Adds support for Numascale NumaChip large-SMP systems. Needed to
413	  enable more than ~168 cores.
414	  If you don't have one of these, you should say N here.
415
416config X86_VSMP
417	bool "ScaleMP vSMP"
418	select HYPERVISOR_GUEST
419	select PARAVIRT
420	depends on X86_64 && PCI
421	depends on X86_EXTENDED_PLATFORM
422	depends on SMP
423	---help---
424	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
425	  supposed to run on these EM64T-based machines.  Only choose this option
426	  if you have one of these machines.
427
428config X86_UV
429	bool "SGI Ultraviolet"
430	depends on X86_64
431	depends on X86_EXTENDED_PLATFORM
432	depends on NUMA
433	depends on X86_X2APIC
434	---help---
435	  This option is needed in order to support SGI Ultraviolet systems.
436	  If you don't have one of these, you should say N here.
437
438# Following is an alphabetically sorted list of 32 bit extended platforms
439# Please maintain the alphabetic order if and when there are additions
440
441config X86_GOLDFISH
442       bool "Goldfish (Virtual Platform)"
443       depends on X86_EXTENDED_PLATFORM
444       ---help---
445	 Enable support for the Goldfish virtual platform used primarily
446	 for Android development. Unless you are building for the Android
447	 Goldfish emulator say N here.
448
449config X86_INTEL_CE
450	bool "CE4100 TV platform"
451	depends on PCI
452	depends on PCI_GODIRECT
453	depends on X86_IO_APIC
454	depends on X86_32
455	depends on X86_EXTENDED_PLATFORM
456	select X86_REBOOTFIXUPS
457	select OF
458	select OF_EARLY_FLATTREE
459	select IRQ_DOMAIN
460	---help---
461	  Select for the Intel CE media processor (CE4100) SOC.
462	  This option compiles in support for the CE4100 SOC for settop
463	  boxes and media devices.
464
465config X86_INTEL_MID
466	bool "Intel MID platform support"
467	depends on X86_32
468	depends on X86_EXTENDED_PLATFORM
469	depends on X86_PLATFORM_DEVICES
470	depends on PCI
471	depends on PCI_GOANY
472	depends on X86_IO_APIC
473	select SFI
474	select I2C
475	select DW_APB_TIMER
476	select APB_TIMER
477	select INTEL_SCU_IPC
478	select MFD_INTEL_MSIC
479	---help---
480	  Select to build a kernel capable of supporting Intel MID (Mobile
481	  Internet Device) platform systems which do not have the PCI legacy
482	  interfaces. If you are building for a PC class system say N here.
483
484	  Intel MID platforms are based on an Intel processor and chipset which
485	  consume less power than most of the x86 derivatives.
486
487config X86_INTEL_LPSS
488	bool "Intel Low Power Subsystem Support"
489	depends on ACPI
490	select COMMON_CLK
491	select PINCTRL
492	---help---
493	  Select to build support for Intel Low Power Subsystem such as
494	  found on Intel Lynxpoint PCH. Selecting this option enables
495	  things like clock tree (common clock framework) and pincontrol
496	  which are needed by the LPSS peripheral drivers.
497
498config IOSF_MBI
499	tristate "Intel SoC IOSF Sideband support for SoC platforms"
500	depends on PCI
501	---help---
502	  This option enables sideband register access support for Intel SoC
503	  platforms. On these platforms the IOSF sideband is used in lieu of
504	  MSR's for some register accesses, mostly but not limited to thermal
505	  and power. Drivers may query the availability of this device to
506	  determine if they need the sideband in order to work on these
507	  platforms. The sideband is available on the following SoC products.
508	  This list is not meant to be exclusive.
509	   - BayTrail
510	   - Braswell
511	   - Quark
512
513	  You should say Y if you are running a kernel on one of these SoC's.
514
515config IOSF_MBI_DEBUG
516	bool "Enable IOSF sideband access through debugfs"
517	depends on IOSF_MBI && DEBUG_FS
518	---help---
519	  Select this option to expose the IOSF sideband access registers (MCR,
520	  MDR, MCRX) through debugfs to write and read register information from
521	  different units on the SoC. This is most useful for obtaining device
522	  state information for debug and analysis. As this is a general access
523	  mechanism, users of this option would have specific knowledge of the
524	  device they want to access.
525
526	  If you don't require the option or are in doubt, say N.
527
528config X86_RDC321X
529	bool "RDC R-321x SoC"
530	depends on X86_32
531	depends on X86_EXTENDED_PLATFORM
532	select M486
533	select X86_REBOOTFIXUPS
534	---help---
535	  This option is needed for RDC R-321x system-on-chip, also known
536	  as R-8610-(G).
537	  If you don't have one of these chips, you should say N here.
538
539config X86_32_NON_STANDARD
540	bool "Support non-standard 32-bit SMP architectures"
541	depends on X86_32 && SMP
542	depends on X86_EXTENDED_PLATFORM
543	---help---
544	  This option compiles in the bigsmp and STA2X11 default
545	  subarchitectures.  It is intended for a generic binary
546	  kernel. If you select them all, kernel will probe it one by
547	  one and will fallback to default.
548
549# Alphabetically sorted list of Non standard 32 bit platforms
550
551config X86_SUPPORTS_MEMORY_FAILURE
552	def_bool y
553	# MCE code calls memory_failure():
554	depends on X86_MCE
555	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
556	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
557	depends on X86_64 || !SPARSEMEM
558	select ARCH_SUPPORTS_MEMORY_FAILURE
559
560config STA2X11
561	bool "STA2X11 Companion Chip Support"
562	depends on X86_32_NON_STANDARD && PCI
563	select X86_DEV_DMA_OPS
564	select X86_DMA_REMAP
565	select SWIOTLB
566	select MFD_STA2X11
567	select ARCH_REQUIRE_GPIOLIB
568	default n
569	---help---
570	  This adds support for boards based on the STA2X11 IO-Hub,
571	  a.k.a. "ConneXt". The chip is used in place of the standard
572	  PC chipset, so all "standard" peripherals are missing. If this
573	  option is selected the kernel will still be able to boot on
574	  standard PC machines.
575
576config X86_32_IRIS
577	tristate "Eurobraille/Iris poweroff module"
578	depends on X86_32
579	---help---
580	  The Iris machines from EuroBraille do not have APM or ACPI support
581	  to shut themselves down properly.  A special I/O sequence is
582	  needed to do so, which is what this module does at
583	  kernel shutdown.
584
585	  This is only for Iris machines from EuroBraille.
586
587	  If unused, say N.
588
589config SCHED_OMIT_FRAME_POINTER
590	def_bool y
591	prompt "Single-depth WCHAN output"
592	depends on X86
593	---help---
594	  Calculate simpler /proc/<PID>/wchan values. If this option
595	  is disabled then wchan values will recurse back to the
596	  caller function. This provides more accurate wchan values,
597	  at the expense of slightly more scheduling overhead.
598
599	  If in doubt, say "Y".
600
601menuconfig HYPERVISOR_GUEST
602	bool "Linux guest support"
603	---help---
604	  Say Y here to enable options for running Linux under various hyper-
605	  visors. This option enables basic hypervisor detection and platform
606	  setup.
607
608	  If you say N, all options in this submenu will be skipped and
609	  disabled, and Linux guest support won't be built in.
610
611if HYPERVISOR_GUEST
612
613config PARAVIRT
614	bool "Enable paravirtualization code"
615	---help---
616	  This changes the kernel so it can modify itself when it is run
617	  under a hypervisor, potentially improving performance significantly
618	  over full virtualization.  However, when run without a hypervisor
619	  the kernel is theoretically slower and slightly larger.
620
621config PARAVIRT_DEBUG
622	bool "paravirt-ops debugging"
623	depends on PARAVIRT && DEBUG_KERNEL
624	---help---
625	  Enable to debug paravirt_ops internals.  Specifically, BUG if
626	  a paravirt_op is missing when it is called.
627
628config PARAVIRT_SPINLOCKS
629	bool "Paravirtualization layer for spinlocks"
630	depends on PARAVIRT && SMP
631	select UNINLINE_SPIN_UNLOCK
632	---help---
633	  Paravirtualized spinlocks allow a pvops backend to replace the
634	  spinlock implementation with something virtualization-friendly
635	  (for example, block the virtual CPU rather than spinning).
636
637	  It has a minimal impact on native kernels and gives a nice performance
638	  benefit on paravirtualized KVM / Xen kernels.
639
640	  If you are unsure how to answer this question, answer Y.
641
642source "arch/x86/xen/Kconfig"
643
644config KVM_GUEST
645	bool "KVM Guest support (including kvmclock)"
646	depends on PARAVIRT
647	select PARAVIRT_CLOCK
648	default y
649	---help---
650	  This option enables various optimizations for running under the KVM
651	  hypervisor. It includes a paravirtualized clock, so that instead
652	  of relying on a PIT (or probably other) emulation by the
653	  underlying device model, the host provides the guest with
654	  timing infrastructure such as time of day, and system time
655
656config KVM_DEBUG_FS
657	bool "Enable debug information for KVM Guests in debugfs"
658	depends on KVM_GUEST && DEBUG_FS
659	default n
660	---help---
661	  This option enables collection of various statistics for KVM guest.
662	  Statistics are displayed in debugfs filesystem. Enabling this option
663	  may incur significant overhead.
664
665source "arch/x86/lguest/Kconfig"
666
667config PARAVIRT_TIME_ACCOUNTING
668	bool "Paravirtual steal time accounting"
669	depends on PARAVIRT
670	default n
671	---help---
672	  Select this option to enable fine granularity task steal time
673	  accounting. Time spent executing other tasks in parallel with
674	  the current vCPU is discounted from the vCPU power. To account for
675	  that, there can be a small performance impact.
676
677	  If in doubt, say N here.
678
679config PARAVIRT_CLOCK
680	bool
681
682endif #HYPERVISOR_GUEST
683
684config NO_BOOTMEM
685	def_bool y
686
687config MEMTEST
688	bool "Memtest"
689	---help---
690	  This option adds a kernel parameter 'memtest', which allows memtest
691	  to be set.
692	        memtest=0, mean disabled; -- default
693	        memtest=1, mean do 1 test pattern;
694	        ...
695	        memtest=4, mean do 4 test patterns.
696	  If you are unsure how to answer this question, answer N.
697
698source "arch/x86/Kconfig.cpu"
699
700config HPET_TIMER
701	def_bool X86_64
702	prompt "HPET Timer Support" if X86_32
703	---help---
704	  Use the IA-PC HPET (High Precision Event Timer) to manage
705	  time in preference to the PIT and RTC, if a HPET is
706	  present.
707	  HPET is the next generation timer replacing legacy 8254s.
708	  The HPET provides a stable time base on SMP
709	  systems, unlike the TSC, but it is more expensive to access,
710	  as it is off-chip.  You can find the HPET spec at
711	  <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
712
713	  You can safely choose Y here.  However, HPET will only be
714	  activated if the platform and the BIOS support this feature.
715	  Otherwise the 8254 will be used for timing services.
716
717	  Choose N to continue using the legacy 8254 timer.
718
719config HPET_EMULATE_RTC
720	def_bool y
721	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
722
723config APB_TIMER
724       def_bool y if X86_INTEL_MID
725       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
726       select DW_APB_TIMER
727       depends on X86_INTEL_MID && SFI
728       help
729         APB timer is the replacement for 8254, HPET on X86 MID platforms.
730         The APBT provides a stable time base on SMP
731         systems, unlike the TSC, but it is more expensive to access,
732         as it is off-chip. APB timers are always running regardless of CPU
733         C states, they are used as per CPU clockevent device when possible.
734
735# Mark as expert because too many people got it wrong.
736# The code disables itself when not needed.
737config DMI
738	default y
739	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
740	bool "Enable DMI scanning" if EXPERT
741	---help---
742	  Enabled scanning of DMI to identify machine quirks. Say Y
743	  here unless you have verified that your setup is not
744	  affected by entries in the DMI blacklist. Required by PNP
745	  BIOS code.
746
747config GART_IOMMU
748	bool "Old AMD GART IOMMU support"
749	select SWIOTLB
750	depends on X86_64 && PCI && AMD_NB
751	---help---
752	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
753	  GART based hardware IOMMUs.
754
755	  The GART supports full DMA access for devices with 32-bit access
756	  limitations, on systems with more than 3 GB. This is usually needed
757	  for USB, sound, many IDE/SATA chipsets and some other devices.
758
759	  Newer systems typically have a modern AMD IOMMU, supported via
760	  the CONFIG_AMD_IOMMU=y config option.
761
762	  In normal configurations this driver is only active when needed:
763	  there's more than 3 GB of memory and the system contains a
764	  32-bit limited device.
765
766	  If unsure, say Y.
767
768config CALGARY_IOMMU
769	bool "IBM Calgary IOMMU support"
770	select SWIOTLB
771	depends on X86_64 && PCI
772	---help---
773	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
774	  systems. Needed to run systems with more than 3GB of memory
775	  properly with 32-bit PCI devices that do not support DAC
776	  (Double Address Cycle). Calgary also supports bus level
777	  isolation, where all DMAs pass through the IOMMU.  This
778	  prevents them from going anywhere except their intended
779	  destination. This catches hard-to-find kernel bugs and
780	  mis-behaving drivers and devices that do not use the DMA-API
781	  properly to set up their DMA buffers.  The IOMMU can be
782	  turned off at boot time with the iommu=off parameter.
783	  Normally the kernel will make the right choice by itself.
784	  If unsure, say Y.
785
786config CALGARY_IOMMU_ENABLED_BY_DEFAULT
787	def_bool y
788	prompt "Should Calgary be enabled by default?"
789	depends on CALGARY_IOMMU
790	---help---
791	  Should Calgary be enabled by default? if you choose 'y', Calgary
792	  will be used (if it exists). If you choose 'n', Calgary will not be
793	  used even if it exists. If you choose 'n' and would like to use
794	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
795	  If unsure, say Y.
796
797# need this always selected by IOMMU for the VIA workaround
798config SWIOTLB
799	def_bool y if X86_64
800	---help---
801	  Support for software bounce buffers used on x86-64 systems
802	  which don't have a hardware IOMMU. Using this PCI devices
803	  which can only access 32-bits of memory can be used on systems
804	  with more than 3 GB of memory.
805	  If unsure, say Y.
806
807config IOMMU_HELPER
808	def_bool y
809	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
810
811config MAXSMP
812	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
813	depends on X86_64 && SMP && DEBUG_KERNEL
814	select CPUMASK_OFFSTACK
815	---help---
816	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
817	  If unsure, say N.
818
819config NR_CPUS
820	int "Maximum number of CPUs" if SMP && !MAXSMP
821	range 2 8 if SMP && X86_32 && !X86_BIGSMP
822	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
823	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
824	default "1" if !SMP
825	default "8192" if MAXSMP
826	default "32" if SMP && X86_BIGSMP
827	default "8" if SMP
828	---help---
829	  This allows you to specify the maximum number of CPUs which this
830	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
831	  supported value is 4096, otherwise the maximum value is 512.  The
832	  minimum value which makes sense is 2.
833
834	  This is purely to save memory - each supported CPU adds
835	  approximately eight kilobytes to the kernel image.
836
837config SCHED_SMT
838	bool "SMT (Hyperthreading) scheduler support"
839	depends on X86_HT
840	---help---
841	  SMT scheduler support improves the CPU scheduler's decision making
842	  when dealing with Intel Pentium 4 chips with HyperThreading at a
843	  cost of slightly increased overhead in some places. If unsure say
844	  N here.
845
846config SCHED_MC
847	def_bool y
848	prompt "Multi-core scheduler support"
849	depends on X86_HT
850	---help---
851	  Multi-core scheduler support improves the CPU scheduler's decision
852	  making when dealing with multi-core CPU chips at a cost of slightly
853	  increased overhead in some places. If unsure say N here.
854
855source "kernel/Kconfig.preempt"
856
857config X86_UP_APIC
858	bool "Local APIC support on uniprocessors"
859	depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
860	---help---
861	  A local APIC (Advanced Programmable Interrupt Controller) is an
862	  integrated interrupt controller in the CPU. If you have a single-CPU
863	  system which has a processor with a local APIC, you can say Y here to
864	  enable and use it. If you say Y here even though your machine doesn't
865	  have a local APIC, then the kernel will still run with no slowdown at
866	  all. The local APIC supports CPU-generated self-interrupts (timer,
867	  performance counters), and the NMI watchdog which detects hard
868	  lockups.
869
870config X86_UP_IOAPIC
871	bool "IO-APIC support on uniprocessors"
872	depends on X86_UP_APIC
873	---help---
874	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
875	  SMP-capable replacement for PC-style interrupt controllers. Most
876	  SMP systems and many recent uniprocessor systems have one.
877
878	  If you have a single-CPU system with an IO-APIC, you can say Y here
879	  to use it. If you say Y here even though your machine doesn't have
880	  an IO-APIC, then the kernel will still run with no slowdown at all.
881
882config X86_LOCAL_APIC
883	def_bool y
884	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
885
886config X86_IO_APIC
887	def_bool y
888	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
889	select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
890	select IRQ_DOMAIN
891
892config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
893	bool "Reroute for broken boot IRQs"
894	depends on X86_IO_APIC
895	---help---
896	  This option enables a workaround that fixes a source of
897	  spurious interrupts. This is recommended when threaded
898	  interrupt handling is used on systems where the generation of
899	  superfluous "boot interrupts" cannot be disabled.
900
901	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
902	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
903	  kernel does during interrupt handling). On chipsets where this
904	  boot IRQ generation cannot be disabled, this workaround keeps
905	  the original IRQ line masked so that only the equivalent "boot
906	  IRQ" is delivered to the CPUs. The workaround also tells the
907	  kernel to set up the IRQ handler on the boot IRQ line. In this
908	  way only one interrupt is delivered to the kernel. Otherwise
909	  the spurious second interrupt may cause the kernel to bring
910	  down (vital) interrupt lines.
911
912	  Only affects "broken" chipsets. Interrupt sharing may be
913	  increased on these systems.
914
915config X86_MCE
916	bool "Machine Check / overheating reporting"
917	default y
918	---help---
919	  Machine Check support allows the processor to notify the
920	  kernel if it detects a problem (e.g. overheating, data corruption).
921	  The action the kernel takes depends on the severity of the problem,
922	  ranging from warning messages to halting the machine.
923
924config X86_MCE_INTEL
925	def_bool y
926	prompt "Intel MCE features"
927	depends on X86_MCE && X86_LOCAL_APIC
928	---help---
929	   Additional support for intel specific MCE features such as
930	   the thermal monitor.
931
932config X86_MCE_AMD
933	def_bool y
934	prompt "AMD MCE features"
935	depends on X86_MCE && X86_LOCAL_APIC
936	---help---
937	   Additional support for AMD specific MCE features such as
938	   the DRAM Error Threshold.
939
940config X86_ANCIENT_MCE
941	bool "Support for old Pentium 5 / WinChip machine checks"
942	depends on X86_32 && X86_MCE
943	---help---
944	  Include support for machine check handling on old Pentium 5 or WinChip
945	  systems. These typically need to be enabled explicitly on the command
946	  line.
947
948config X86_MCE_THRESHOLD
949	depends on X86_MCE_AMD || X86_MCE_INTEL
950	def_bool y
951
952config X86_MCE_INJECT
953	depends on X86_MCE
954	tristate "Machine check injector support"
955	---help---
956	  Provide support for injecting machine checks for testing purposes.
957	  If you don't know what a machine check is and you don't do kernel
958	  QA it is safe to say n.
959
960config X86_THERMAL_VECTOR
961	def_bool y
962	depends on X86_MCE_INTEL
963
964config VM86
965	bool "Enable VM86 support" if EXPERT
966	default y
967	depends on X86_32
968	---help---
969	  This option is required by programs like DOSEMU to run
970	  16-bit real mode legacy code on x86 processors. It also may
971	  be needed by software like XFree86 to initialize some video
972	  cards via BIOS. Disabling this option saves about 6K.
973
974config X86_16BIT
975	bool "Enable support for 16-bit segments" if EXPERT
976	default y
977	---help---
978	  This option is required by programs like Wine to run 16-bit
979	  protected mode legacy code on x86 processors.  Disabling
980	  this option saves about 300 bytes on i386, or around 6K text
981	  plus 16K runtime memory on x86-64,
982
983config X86_ESPFIX32
984	def_bool y
985	depends on X86_16BIT && X86_32
986
987config X86_ESPFIX64
988	def_bool y
989	depends on X86_16BIT && X86_64
990
991config TOSHIBA
992	tristate "Toshiba Laptop support"
993	depends on X86_32
994	---help---
995	  This adds a driver to safely access the System Management Mode of
996	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
997	  not work on models with a Phoenix BIOS. The System Management Mode
998	  is used to set the BIOS and power saving options on Toshiba portables.
999
1000	  For information on utilities to make use of this driver see the
1001	  Toshiba Linux utilities web site at:
1002	  <http://www.buzzard.org.uk/toshiba/>.
1003
1004	  Say Y if you intend to run this kernel on a Toshiba portable.
1005	  Say N otherwise.
1006
1007config I8K
1008	tristate "Dell laptop support"
1009	select HWMON
1010	---help---
1011	  This adds a driver to safely access the System Management Mode
1012	  of the CPU on the Dell Inspiron 8000. The System Management Mode
1013	  is used to read cpu temperature and cooling fan status and to
1014	  control the fans on the I8K portables.
1015
1016	  This driver has been tested only on the Inspiron 8000 but it may
1017	  also work with other Dell laptops. You can force loading on other
1018	  models by passing the parameter `force=1' to the module. Use at
1019	  your own risk.
1020
1021	  For information on utilities to make use of this driver see the
1022	  I8K Linux utilities web site at:
1023	  <http://people.debian.org/~dz/i8k/>
1024
1025	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1026	  Say N otherwise.
1027
1028config X86_REBOOTFIXUPS
1029	bool "Enable X86 board specific fixups for reboot"
1030	depends on X86_32
1031	---help---
1032	  This enables chipset and/or board specific fixups to be done
1033	  in order to get reboot to work correctly. This is only needed on
1034	  some combinations of hardware and BIOS. The symptom, for which
1035	  this config is intended, is when reboot ends with a stalled/hung
1036	  system.
1037
1038	  Currently, the only fixup is for the Geode machines using
1039	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1040
1041	  Say Y if you want to enable the fixup. Currently, it's safe to
1042	  enable this option even if you don't need it.
1043	  Say N otherwise.
1044
1045config MICROCODE
1046	tristate "CPU microcode loading support"
1047	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1048	select FW_LOADER
1049	---help---
1050
1051	  If you say Y here, you will be able to update the microcode on
1052	  certain Intel and AMD processors. The Intel support is for the
1053	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1054	  Xeon etc. The AMD support is for families 0x10 and later. You will
1055	  obviously need the actual microcode binary data itself which is not
1056	  shipped with the Linux kernel.
1057
1058	  This option selects the general module only, you need to select
1059	  at least one vendor specific module as well.
1060
1061	  To compile this driver as a module, choose M here: the module
1062	  will be called microcode.
1063
1064config MICROCODE_INTEL
1065	bool "Intel microcode loading support"
1066	depends on MICROCODE
1067	default MICROCODE
1068	select FW_LOADER
1069	---help---
1070	  This options enables microcode patch loading support for Intel
1071	  processors.
1072
1073	  For the current Intel microcode data package go to
1074	  <https://downloadcenter.intel.com> and search for
1075	  'Linux Processor Microcode Data File'.
1076
1077config MICROCODE_AMD
1078	bool "AMD microcode loading support"
1079	depends on MICROCODE
1080	select FW_LOADER
1081	---help---
1082	  If you select this option, microcode patch loading support for AMD
1083	  processors will be enabled.
1084
1085config MICROCODE_OLD_INTERFACE
1086	def_bool y
1087	depends on MICROCODE
1088
1089config MICROCODE_INTEL_EARLY
1090	def_bool n
1091
1092config MICROCODE_AMD_EARLY
1093	def_bool n
1094
1095config MICROCODE_EARLY
1096	bool "Early load microcode"
1097	depends on MICROCODE=y && BLK_DEV_INITRD
1098	select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1099	select MICROCODE_AMD_EARLY if MICROCODE_AMD
1100	default y
1101	help
1102	  This option provides functionality to read additional microcode data
1103	  at the beginning of initrd image. The data tells kernel to load
1104	  microcode to CPU's as early as possible. No functional change if no
1105	  microcode data is glued to the initrd, therefore it's safe to say Y.
1106
1107config X86_MSR
1108	tristate "/dev/cpu/*/msr - Model-specific register support"
1109	---help---
1110	  This device gives privileged processes access to the x86
1111	  Model-Specific Registers (MSRs).  It is a character device with
1112	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1113	  MSR accesses are directed to a specific CPU on multi-processor
1114	  systems.
1115
1116config X86_CPUID
1117	tristate "/dev/cpu/*/cpuid - CPU information support"
1118	---help---
1119	  This device gives processes access to the x86 CPUID instruction to
1120	  be executed on a specific processor.  It is a character device
1121	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1122	  /dev/cpu/31/cpuid.
1123
1124choice
1125	prompt "High Memory Support"
1126	default HIGHMEM4G
1127	depends on X86_32
1128
1129config NOHIGHMEM
1130	bool "off"
1131	---help---
1132	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1133	  However, the address space of 32-bit x86 processors is only 4
1134	  Gigabytes large. That means that, if you have a large amount of
1135	  physical memory, not all of it can be "permanently mapped" by the
1136	  kernel. The physical memory that's not permanently mapped is called
1137	  "high memory".
1138
1139	  If you are compiling a kernel which will never run on a machine with
1140	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1141	  choice and suitable for most users). This will result in a "3GB/1GB"
1142	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1143	  space and the remaining part of the 4GB virtual memory space is used
1144	  by the kernel to permanently map as much physical memory as
1145	  possible.
1146
1147	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1148	  answer "4GB" here.
1149
1150	  If more than 4 Gigabytes is used then answer "64GB" here. This
1151	  selection turns Intel PAE (Physical Address Extension) mode on.
1152	  PAE implements 3-level paging on IA32 processors. PAE is fully
1153	  supported by Linux, PAE mode is implemented on all recent Intel
1154	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1155	  then the kernel will not boot on CPUs that don't support PAE!
1156
1157	  The actual amount of total physical memory will either be
1158	  auto detected or can be forced by using a kernel command line option
1159	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1160	  your boot loader (lilo or loadlin) about how to pass options to the
1161	  kernel at boot time.)
1162
1163	  If unsure, say "off".
1164
1165config HIGHMEM4G
1166	bool "4GB"
1167	---help---
1168	  Select this if you have a 32-bit processor and between 1 and 4
1169	  gigabytes of physical RAM.
1170
1171config HIGHMEM64G
1172	bool "64GB"
1173	depends on !M486
1174	select X86_PAE
1175	---help---
1176	  Select this if you have a 32-bit processor and more than 4
1177	  gigabytes of physical RAM.
1178
1179endchoice
1180
1181choice
1182	prompt "Memory split" if EXPERT
1183	default VMSPLIT_3G
1184	depends on X86_32
1185	---help---
1186	  Select the desired split between kernel and user memory.
1187
1188	  If the address range available to the kernel is less than the
1189	  physical memory installed, the remaining memory will be available
1190	  as "high memory". Accessing high memory is a little more costly
1191	  than low memory, as it needs to be mapped into the kernel first.
1192	  Note that increasing the kernel address space limits the range
1193	  available to user programs, making the address space there
1194	  tighter.  Selecting anything other than the default 3G/1G split
1195	  will also likely make your kernel incompatible with binary-only
1196	  kernel modules.
1197
1198	  If you are not absolutely sure what you are doing, leave this
1199	  option alone!
1200
1201	config VMSPLIT_3G
1202		bool "3G/1G user/kernel split"
1203	config VMSPLIT_3G_OPT
1204		depends on !X86_PAE
1205		bool "3G/1G user/kernel split (for full 1G low memory)"
1206	config VMSPLIT_2G
1207		bool "2G/2G user/kernel split"
1208	config VMSPLIT_2G_OPT
1209		depends on !X86_PAE
1210		bool "2G/2G user/kernel split (for full 2G low memory)"
1211	config VMSPLIT_1G
1212		bool "1G/3G user/kernel split"
1213endchoice
1214
1215config PAGE_OFFSET
1216	hex
1217	default 0xB0000000 if VMSPLIT_3G_OPT
1218	default 0x80000000 if VMSPLIT_2G
1219	default 0x78000000 if VMSPLIT_2G_OPT
1220	default 0x40000000 if VMSPLIT_1G
1221	default 0xC0000000
1222	depends on X86_32
1223
1224config HIGHMEM
1225	def_bool y
1226	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1227
1228config X86_PAE
1229	bool "PAE (Physical Address Extension) Support"
1230	depends on X86_32 && !HIGHMEM4G
1231	---help---
1232	  PAE is required for NX support, and furthermore enables
1233	  larger swapspace support for non-overcommit purposes. It
1234	  has the cost of more pagetable lookup overhead, and also
1235	  consumes more pagetable space per process.
1236
1237config ARCH_PHYS_ADDR_T_64BIT
1238	def_bool y
1239	depends on X86_64 || X86_PAE
1240
1241config ARCH_DMA_ADDR_T_64BIT
1242	def_bool y
1243	depends on X86_64 || HIGHMEM64G
1244
1245config DIRECT_GBPAGES
1246	bool "Enable 1GB pages for kernel pagetables" if EXPERT
1247	default y
1248	depends on X86_64
1249	---help---
1250	  Allow the kernel linear mapping to use 1GB pages on CPUs that
1251	  support it. This can improve the kernel's performance a tiny bit by
1252	  reducing TLB pressure. If in doubt, say "Y".
1253
1254# Common NUMA Features
1255config NUMA
1256	bool "Numa Memory Allocation and Scheduler Support"
1257	depends on SMP
1258	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1259	default y if X86_BIGSMP
1260	---help---
1261	  Enable NUMA (Non Uniform Memory Access) support.
1262
1263	  The kernel will try to allocate memory used by a CPU on the
1264	  local memory controller of the CPU and add some more
1265	  NUMA awareness to the kernel.
1266
1267	  For 64-bit this is recommended if the system is Intel Core i7
1268	  (or later), AMD Opteron, or EM64T NUMA.
1269
1270	  For 32-bit this is only needed if you boot a 32-bit
1271	  kernel on a 64-bit NUMA platform.
1272
1273	  Otherwise, you should say N.
1274
1275config AMD_NUMA
1276	def_bool y
1277	prompt "Old style AMD Opteron NUMA detection"
1278	depends on X86_64 && NUMA && PCI
1279	---help---
1280	  Enable AMD NUMA node topology detection.  You should say Y here if
1281	  you have a multi processor AMD system. This uses an old method to
1282	  read the NUMA configuration directly from the builtin Northbridge
1283	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1284	  which also takes priority if both are compiled in.
1285
1286config X86_64_ACPI_NUMA
1287	def_bool y
1288	prompt "ACPI NUMA detection"
1289	depends on X86_64 && NUMA && ACPI && PCI
1290	select ACPI_NUMA
1291	---help---
1292	  Enable ACPI SRAT based node topology detection.
1293
1294# Some NUMA nodes have memory ranges that span
1295# other nodes.  Even though a pfn is valid and
1296# between a node's start and end pfns, it may not
1297# reside on that node.  See memmap_init_zone()
1298# for details.
1299config NODES_SPAN_OTHER_NODES
1300	def_bool y
1301	depends on X86_64_ACPI_NUMA
1302
1303config NUMA_EMU
1304	bool "NUMA emulation"
1305	depends on NUMA
1306	---help---
1307	  Enable NUMA emulation. A flat machine will be split
1308	  into virtual nodes when booted with "numa=fake=N", where N is the
1309	  number of nodes. This is only useful for debugging.
1310
1311config NODES_SHIFT
1312	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1313	range 1 10
1314	default "10" if MAXSMP
1315	default "6" if X86_64
1316	default "3"
1317	depends on NEED_MULTIPLE_NODES
1318	---help---
1319	  Specify the maximum number of NUMA Nodes available on the target
1320	  system.  Increases memory reserved to accommodate various tables.
1321
1322config ARCH_HAVE_MEMORY_PRESENT
1323	def_bool y
1324	depends on X86_32 && DISCONTIGMEM
1325
1326config NEED_NODE_MEMMAP_SIZE
1327	def_bool y
1328	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1329
1330config ARCH_FLATMEM_ENABLE
1331	def_bool y
1332	depends on X86_32 && !NUMA
1333
1334config ARCH_DISCONTIGMEM_ENABLE
1335	def_bool y
1336	depends on NUMA && X86_32
1337
1338config ARCH_DISCONTIGMEM_DEFAULT
1339	def_bool y
1340	depends on NUMA && X86_32
1341
1342config ARCH_SPARSEMEM_ENABLE
1343	def_bool y
1344	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1345	select SPARSEMEM_STATIC if X86_32
1346	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1347
1348config ARCH_SPARSEMEM_DEFAULT
1349	def_bool y
1350	depends on X86_64
1351
1352config ARCH_SELECT_MEMORY_MODEL
1353	def_bool y
1354	depends on ARCH_SPARSEMEM_ENABLE
1355
1356config ARCH_MEMORY_PROBE
1357	bool "Enable sysfs memory/probe interface"
1358	depends on X86_64 && MEMORY_HOTPLUG
1359	help
1360	  This option enables a sysfs memory/probe interface for testing.
1361	  See Documentation/memory-hotplug.txt for more information.
1362	  If you are unsure how to answer this question, answer N.
1363
1364config ARCH_PROC_KCORE_TEXT
1365	def_bool y
1366	depends on X86_64 && PROC_KCORE
1367
1368config ILLEGAL_POINTER_VALUE
1369       hex
1370       default 0 if X86_32
1371       default 0xdead000000000000 if X86_64
1372
1373source "mm/Kconfig"
1374
1375config HIGHPTE
1376	bool "Allocate 3rd-level pagetables from highmem"
1377	depends on HIGHMEM
1378	---help---
1379	  The VM uses one page table entry for each page of physical memory.
1380	  For systems with a lot of RAM, this can be wasteful of precious
1381	  low memory.  Setting this option will put user-space page table
1382	  entries in high memory.
1383
1384config X86_CHECK_BIOS_CORRUPTION
1385	bool "Check for low memory corruption"
1386	---help---
1387	  Periodically check for memory corruption in low memory, which
1388	  is suspected to be caused by BIOS.  Even when enabled in the
1389	  configuration, it is disabled at runtime.  Enable it by
1390	  setting "memory_corruption_check=1" on the kernel command
1391	  line.  By default it scans the low 64k of memory every 60
1392	  seconds; see the memory_corruption_check_size and
1393	  memory_corruption_check_period parameters in
1394	  Documentation/kernel-parameters.txt to adjust this.
1395
1396	  When enabled with the default parameters, this option has
1397	  almost no overhead, as it reserves a relatively small amount
1398	  of memory and scans it infrequently.  It both detects corruption
1399	  and prevents it from affecting the running system.
1400
1401	  It is, however, intended as a diagnostic tool; if repeatable
1402	  BIOS-originated corruption always affects the same memory,
1403	  you can use memmap= to prevent the kernel from using that
1404	  memory.
1405
1406config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1407	bool "Set the default setting of memory_corruption_check"
1408	depends on X86_CHECK_BIOS_CORRUPTION
1409	default y
1410	---help---
1411	  Set whether the default state of memory_corruption_check is
1412	  on or off.
1413
1414config X86_RESERVE_LOW
1415	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1416	default 64
1417	range 4 640
1418	---help---
1419	  Specify the amount of low memory to reserve for the BIOS.
1420
1421	  The first page contains BIOS data structures that the kernel
1422	  must not use, so that page must always be reserved.
1423
1424	  By default we reserve the first 64K of physical RAM, as a
1425	  number of BIOSes are known to corrupt that memory range
1426	  during events such as suspend/resume or monitor cable
1427	  insertion, so it must not be used by the kernel.
1428
1429	  You can set this to 4 if you are absolutely sure that you
1430	  trust the BIOS to get all its memory reservations and usages
1431	  right.  If you know your BIOS have problems beyond the
1432	  default 64K area, you can set this to 640 to avoid using the
1433	  entire low memory range.
1434
1435	  If you have doubts about the BIOS (e.g. suspend/resume does
1436	  not work or there's kernel crashes after certain hardware
1437	  hotplug events) then you might want to enable
1438	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1439	  typical corruption patterns.
1440
1441	  Leave this to the default value of 64 if you are unsure.
1442
1443config MATH_EMULATION
1444	bool
1445	prompt "Math emulation" if X86_32
1446	---help---
1447	  Linux can emulate a math coprocessor (used for floating point
1448	  operations) if you don't have one. 486DX and Pentium processors have
1449	  a math coprocessor built in, 486SX and 386 do not, unless you added
1450	  a 487DX or 387, respectively. (The messages during boot time can
1451	  give you some hints here ["man dmesg"].) Everyone needs either a
1452	  coprocessor or this emulation.
1453
1454	  If you don't have a math coprocessor, you need to say Y here; if you
1455	  say Y here even though you have a coprocessor, the coprocessor will
1456	  be used nevertheless. (This behavior can be changed with the kernel
1457	  command line option "no387", which comes handy if your coprocessor
1458	  is broken. Try "man bootparam" or see the documentation of your boot
1459	  loader (lilo or loadlin) about how to pass options to the kernel at
1460	  boot time.) This means that it is a good idea to say Y here if you
1461	  intend to use this kernel on different machines.
1462
1463	  More information about the internals of the Linux math coprocessor
1464	  emulation can be found in <file:arch/x86/math-emu/README>.
1465
1466	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1467	  kernel, it won't hurt.
1468
1469config MTRR
1470	def_bool y
1471	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1472	---help---
1473	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1474	  the Memory Type Range Registers (MTRRs) may be used to control
1475	  processor access to memory ranges. This is most useful if you have
1476	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1477	  allows bus write transfers to be combined into a larger transfer
1478	  before bursting over the PCI/AGP bus. This can increase performance
1479	  of image write operations 2.5 times or more. Saying Y here creates a
1480	  /proc/mtrr file which may be used to manipulate your processor's
1481	  MTRRs. Typically the X server should use this.
1482
1483	  This code has a reasonably generic interface so that similar
1484	  control registers on other processors can be easily supported
1485	  as well:
1486
1487	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1488	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1489	  these, the ARRs are used to emulate the MTRRs.
1490	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1491	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1492	  write-combining. All of these processors are supported by this code
1493	  and it makes sense to say Y here if you have one of them.
1494
1495	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1496	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1497	  can lead to all sorts of problems, so it's good to say Y here.
1498
1499	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1500	  just add about 9 KB to your kernel.
1501
1502	  See <file:Documentation/x86/mtrr.txt> for more information.
1503
1504config MTRR_SANITIZER
1505	def_bool y
1506	prompt "MTRR cleanup support"
1507	depends on MTRR
1508	---help---
1509	  Convert MTRR layout from continuous to discrete, so X drivers can
1510	  add writeback entries.
1511
1512	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1513	  The largest mtrr entry size for a continuous block can be set with
1514	  mtrr_chunk_size.
1515
1516	  If unsure, say Y.
1517
1518config MTRR_SANITIZER_ENABLE_DEFAULT
1519	int "MTRR cleanup enable value (0-1)"
1520	range 0 1
1521	default "0"
1522	depends on MTRR_SANITIZER
1523	---help---
1524	  Enable mtrr cleanup default value
1525
1526config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1527	int "MTRR cleanup spare reg num (0-7)"
1528	range 0 7
1529	default "1"
1530	depends on MTRR_SANITIZER
1531	---help---
1532	  mtrr cleanup spare entries default, it can be changed via
1533	  mtrr_spare_reg_nr=N on the kernel command line.
1534
1535config X86_PAT
1536	def_bool y
1537	prompt "x86 PAT support" if EXPERT
1538	depends on MTRR
1539	---help---
1540	  Use PAT attributes to setup page level cache control.
1541
1542	  PATs are the modern equivalents of MTRRs and are much more
1543	  flexible than MTRRs.
1544
1545	  Say N here if you see bootup problems (boot crash, boot hang,
1546	  spontaneous reboots) or a non-working video driver.
1547
1548	  If unsure, say Y.
1549
1550config ARCH_USES_PG_UNCACHED
1551	def_bool y
1552	depends on X86_PAT
1553
1554config ARCH_RANDOM
1555	def_bool y
1556	prompt "x86 architectural random number generator" if EXPERT
1557	---help---
1558	  Enable the x86 architectural RDRAND instruction
1559	  (Intel Bull Mountain technology) to generate random numbers.
1560	  If supported, this is a high bandwidth, cryptographically
1561	  secure hardware random number generator.
1562
1563config X86_SMAP
1564	def_bool y
1565	prompt "Supervisor Mode Access Prevention" if EXPERT
1566	---help---
1567	  Supervisor Mode Access Prevention (SMAP) is a security
1568	  feature in newer Intel processors.  There is a small
1569	  performance cost if this enabled and turned on; there is
1570	  also a small increase in the kernel size if this is enabled.
1571
1572	  If unsure, say Y.
1573
1574config EFI
1575	bool "EFI runtime service support"
1576	depends on ACPI
1577	select UCS2_STRING
1578	select EFI_RUNTIME_WRAPPERS
1579	---help---
1580	  This enables the kernel to use EFI runtime services that are
1581	  available (such as the EFI variable services).
1582
1583	  This option is only useful on systems that have EFI firmware.
1584	  In addition, you should use the latest ELILO loader available
1585	  at <http://elilo.sourceforge.net> in order to take advantage
1586	  of EFI runtime services. However, even with this option, the
1587	  resultant kernel should continue to boot on existing non-EFI
1588	  platforms.
1589
1590config EFI_STUB
1591       bool "EFI stub support"
1592       depends on EFI && !X86_USE_3DNOW
1593       select RELOCATABLE
1594       ---help---
1595          This kernel feature allows a bzImage to be loaded directly
1596	  by EFI firmware without the use of a bootloader.
1597
1598	  See Documentation/efi-stub.txt for more information.
1599
1600config EFI_MIXED
1601	bool "EFI mixed-mode support"
1602	depends on EFI_STUB && X86_64
1603	---help---
1604	   Enabling this feature allows a 64-bit kernel to be booted
1605	   on a 32-bit firmware, provided that your CPU supports 64-bit
1606	   mode.
1607
1608	   Note that it is not possible to boot a mixed-mode enabled
1609	   kernel via the EFI boot stub - a bootloader that supports
1610	   the EFI handover protocol must be used.
1611
1612	   If unsure, say N.
1613
1614config SECCOMP
1615	def_bool y
1616	prompt "Enable seccomp to safely compute untrusted bytecode"
1617	---help---
1618	  This kernel feature is useful for number crunching applications
1619	  that may need to compute untrusted bytecode during their
1620	  execution. By using pipes or other transports made available to
1621	  the process as file descriptors supporting the read/write
1622	  syscalls, it's possible to isolate those applications in
1623	  their own address space using seccomp. Once seccomp is
1624	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1625	  and the task is only allowed to execute a few safe syscalls
1626	  defined by each seccomp mode.
1627
1628	  If unsure, say Y. Only embedded should say N here.
1629
1630source kernel/Kconfig.hz
1631
1632config KEXEC
1633	bool "kexec system call"
1634	---help---
1635	  kexec is a system call that implements the ability to shutdown your
1636	  current kernel, and to start another kernel.  It is like a reboot
1637	  but it is independent of the system firmware.   And like a reboot
1638	  you can start any kernel with it, not just Linux.
1639
1640	  The name comes from the similarity to the exec system call.
1641
1642	  It is an ongoing process to be certain the hardware in a machine
1643	  is properly shutdown, so do not be surprised if this code does not
1644	  initially work for you.  As of this writing the exact hardware
1645	  interface is strongly in flux, so no good recommendation can be
1646	  made.
1647
1648config KEXEC_FILE
1649	bool "kexec file based system call"
1650	select BUILD_BIN2C
1651	depends on KEXEC
1652	depends on X86_64
1653	depends on CRYPTO=y
1654	depends on CRYPTO_SHA256=y
1655	---help---
1656	  This is new version of kexec system call. This system call is
1657	  file based and takes file descriptors as system call argument
1658	  for kernel and initramfs as opposed to list of segments as
1659	  accepted by previous system call.
1660
1661config KEXEC_VERIFY_SIG
1662	bool "Verify kernel signature during kexec_file_load() syscall"
1663	depends on KEXEC_FILE
1664	---help---
1665	  This option makes kernel signature verification mandatory for
1666	  kexec_file_load() syscall. If kernel is signature can not be
1667	  verified, kexec_file_load() will fail.
1668
1669	  This option enforces signature verification at generic level.
1670	  One needs to enable signature verification for type of kernel
1671	  image being loaded to make sure it works. For example, enable
1672	  bzImage signature verification option to be able to load and
1673	  verify signatures of bzImage. Otherwise kernel loading will fail.
1674
1675config KEXEC_BZIMAGE_VERIFY_SIG
1676	bool "Enable bzImage signature verification support"
1677	depends on KEXEC_VERIFY_SIG
1678	depends on SIGNED_PE_FILE_VERIFICATION
1679	select SYSTEM_TRUSTED_KEYRING
1680	---help---
1681	  Enable bzImage signature verification support.
1682
1683config CRASH_DUMP
1684	bool "kernel crash dumps"
1685	depends on X86_64 || (X86_32 && HIGHMEM)
1686	---help---
1687	  Generate crash dump after being started by kexec.
1688	  This should be normally only set in special crash dump kernels
1689	  which are loaded in the main kernel with kexec-tools into
1690	  a specially reserved region and then later executed after
1691	  a crash by kdump/kexec. The crash dump kernel must be compiled
1692	  to a memory address not used by the main kernel or BIOS using
1693	  PHYSICAL_START, or it must be built as a relocatable image
1694	  (CONFIG_RELOCATABLE=y).
1695	  For more details see Documentation/kdump/kdump.txt
1696
1697config KEXEC_JUMP
1698	bool "kexec jump"
1699	depends on KEXEC && HIBERNATION
1700	---help---
1701	  Jump between original kernel and kexeced kernel and invoke
1702	  code in physical address mode via KEXEC
1703
1704config PHYSICAL_START
1705	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1706	default "0x1000000"
1707	---help---
1708	  This gives the physical address where the kernel is loaded.
1709
1710	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1711	  bzImage will decompress itself to above physical address and
1712	  run from there. Otherwise, bzImage will run from the address where
1713	  it has been loaded by the boot loader and will ignore above physical
1714	  address.
1715
1716	  In normal kdump cases one does not have to set/change this option
1717	  as now bzImage can be compiled as a completely relocatable image
1718	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1719	  address. This option is mainly useful for the folks who don't want
1720	  to use a bzImage for capturing the crash dump and want to use a
1721	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
1722	  to be specifically compiled to run from a specific memory area
1723	  (normally a reserved region) and this option comes handy.
1724
1725	  So if you are using bzImage for capturing the crash dump,
1726	  leave the value here unchanged to 0x1000000 and set
1727	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1728	  for capturing the crash dump change this value to start of
1729	  the reserved region.  In other words, it can be set based on
1730	  the "X" value as specified in the "crashkernel=YM@XM"
1731	  command line boot parameter passed to the panic-ed
1732	  kernel. Please take a look at Documentation/kdump/kdump.txt
1733	  for more details about crash dumps.
1734
1735	  Usage of bzImage for capturing the crash dump is recommended as
1736	  one does not have to build two kernels. Same kernel can be used
1737	  as production kernel and capture kernel. Above option should have
1738	  gone away after relocatable bzImage support is introduced. But it
1739	  is present because there are users out there who continue to use
1740	  vmlinux for dump capture. This option should go away down the
1741	  line.
1742
1743	  Don't change this unless you know what you are doing.
1744
1745config RELOCATABLE
1746	bool "Build a relocatable kernel"
1747	default y
1748	---help---
1749	  This builds a kernel image that retains relocation information
1750	  so it can be loaded someplace besides the default 1MB.
1751	  The relocations tend to make the kernel binary about 10% larger,
1752	  but are discarded at runtime.
1753
1754	  One use is for the kexec on panic case where the recovery kernel
1755	  must live at a different physical address than the primary
1756	  kernel.
1757
1758	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1759	  it has been loaded at and the compile time physical address
1760	  (CONFIG_PHYSICAL_START) is used as the minimum location.
1761
1762config RANDOMIZE_BASE
1763	bool "Randomize the address of the kernel image"
1764	depends on RELOCATABLE
1765	default n
1766	---help---
1767	   Randomizes the physical and virtual address at which the
1768	   kernel image is decompressed, as a security feature that
1769	   deters exploit attempts relying on knowledge of the location
1770	   of kernel internals.
1771
1772	   Entropy is generated using the RDRAND instruction if it is
1773	   supported. If RDTSC is supported, it is used as well. If
1774	   neither RDRAND nor RDTSC are supported, then randomness is
1775	   read from the i8254 timer.
1776
1777	   The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1778	   and aligned according to PHYSICAL_ALIGN. Since the kernel is
1779	   built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1780	   minimum of 2MiB, only 10 bits of entropy is theoretically
1781	   possible. At best, due to page table layouts, 64-bit can use
1782	   9 bits of entropy and 32-bit uses 8 bits.
1783
1784	   If unsure, say N.
1785
1786config RANDOMIZE_BASE_MAX_OFFSET
1787	hex "Maximum kASLR offset allowed" if EXPERT
1788	depends on RANDOMIZE_BASE
1789	range 0x0 0x20000000 if X86_32
1790	default "0x20000000" if X86_32
1791	range 0x0 0x40000000 if X86_64
1792	default "0x40000000" if X86_64
1793	---help---
1794	  The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1795	  memory is used to determine the maximal offset in bytes that will
1796	  be applied to the kernel when kernel Address Space Layout
1797	  Randomization (kASLR) is active. This must be a multiple of
1798	  PHYSICAL_ALIGN.
1799
1800	  On 32-bit this is limited to 512MiB by page table layouts. The
1801	  default is 512MiB.
1802
1803	  On 64-bit this is limited by how the kernel fixmap page table is
1804	  positioned, so this cannot be larger than 1GiB currently. Without
1805	  RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1806	  and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1807	  modules area will shrink to compensate, up to the current maximum
1808	  1GiB to 1GiB split. The default is 1GiB.
1809
1810	  If unsure, leave at the default value.
1811
1812# Relocation on x86 needs some additional build support
1813config X86_NEED_RELOCS
1814	def_bool y
1815	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1816
1817config PHYSICAL_ALIGN
1818	hex "Alignment value to which kernel should be aligned"
1819	default "0x200000"
1820	range 0x2000 0x1000000 if X86_32
1821	range 0x200000 0x1000000 if X86_64
1822	---help---
1823	  This value puts the alignment restrictions on physical address
1824	  where kernel is loaded and run from. Kernel is compiled for an
1825	  address which meets above alignment restriction.
1826
1827	  If bootloader loads the kernel at a non-aligned address and
1828	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1829	  address aligned to above value and run from there.
1830
1831	  If bootloader loads the kernel at a non-aligned address and
1832	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1833	  load address and decompress itself to the address it has been
1834	  compiled for and run from there. The address for which kernel is
1835	  compiled already meets above alignment restrictions. Hence the
1836	  end result is that kernel runs from a physical address meeting
1837	  above alignment restrictions.
1838
1839	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
1840	  this value must be a multiple of 0x200000.
1841
1842	  Don't change this unless you know what you are doing.
1843
1844config HOTPLUG_CPU
1845	bool "Support for hot-pluggable CPUs"
1846	depends on SMP
1847	---help---
1848	  Say Y here to allow turning CPUs off and on. CPUs can be
1849	  controlled through /sys/devices/system/cpu.
1850	  ( Note: power management support will enable this option
1851	    automatically on SMP systems. )
1852	  Say N if you want to disable CPU hotplug.
1853
1854config BOOTPARAM_HOTPLUG_CPU0
1855	bool "Set default setting of cpu0_hotpluggable"
1856	default n
1857	depends on HOTPLUG_CPU
1858	---help---
1859	  Set whether default state of cpu0_hotpluggable is on or off.
1860
1861	  Say Y here to enable CPU0 hotplug by default. If this switch
1862	  is turned on, there is no need to give cpu0_hotplug kernel
1863	  parameter and the CPU0 hotplug feature is enabled by default.
1864
1865	  Please note: there are two known CPU0 dependencies if you want
1866	  to enable the CPU0 hotplug feature either by this switch or by
1867	  cpu0_hotplug kernel parameter.
1868
1869	  First, resume from hibernate or suspend always starts from CPU0.
1870	  So hibernate and suspend are prevented if CPU0 is offline.
1871
1872	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1873	  offline if any interrupt can not migrate out of CPU0. There may
1874	  be other CPU0 dependencies.
1875
1876	  Please make sure the dependencies are under your control before
1877	  you enable this feature.
1878
1879	  Say N if you don't want to enable CPU0 hotplug feature by default.
1880	  You still can enable the CPU0 hotplug feature at boot by kernel
1881	  parameter cpu0_hotplug.
1882
1883config DEBUG_HOTPLUG_CPU0
1884	def_bool n
1885	prompt "Debug CPU0 hotplug"
1886	depends on HOTPLUG_CPU
1887	---help---
1888	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1889	  soon as possible and boots up userspace with CPU0 offlined. User
1890	  can online CPU0 back after boot time.
1891
1892	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
1893	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1894	  compilation or giving cpu0_hotplug kernel parameter at boot.
1895
1896	  If unsure, say N.
1897
1898config COMPAT_VDSO
1899	def_bool n
1900	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1901	depends on X86_32 || IA32_EMULATION
1902	---help---
1903	  Certain buggy versions of glibc will crash if they are
1904	  presented with a 32-bit vDSO that is not mapped at the address
1905	  indicated in its segment table.
1906
1907	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1908	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1909	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
1910	  the only released version with the bug, but OpenSUSE 9
1911	  contains a buggy "glibc 2.3.2".
1912
1913	  The symptom of the bug is that everything crashes on startup, saying:
1914	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1915
1916	  Saying Y here changes the default value of the vdso32 boot
1917	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
1918	  This works around the glibc bug but hurts performance.
1919
1920	  If unsure, say N: if you are compiling your own kernel, you
1921	  are unlikely to be using a buggy version of glibc.
1922
1923config CMDLINE_BOOL
1924	bool "Built-in kernel command line"
1925	---help---
1926	  Allow for specifying boot arguments to the kernel at
1927	  build time.  On some systems (e.g. embedded ones), it is
1928	  necessary or convenient to provide some or all of the
1929	  kernel boot arguments with the kernel itself (that is,
1930	  to not rely on the boot loader to provide them.)
1931
1932	  To compile command line arguments into the kernel,
1933	  set this option to 'Y', then fill in the
1934	  the boot arguments in CONFIG_CMDLINE.
1935
1936	  Systems with fully functional boot loaders (i.e. non-embedded)
1937	  should leave this option set to 'N'.
1938
1939config CMDLINE
1940	string "Built-in kernel command string"
1941	depends on CMDLINE_BOOL
1942	default ""
1943	---help---
1944	  Enter arguments here that should be compiled into the kernel
1945	  image and used at boot time.  If the boot loader provides a
1946	  command line at boot time, it is appended to this string to
1947	  form the full kernel command line, when the system boots.
1948
1949	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1950	  change this behavior.
1951
1952	  In most cases, the command line (whether built-in or provided
1953	  by the boot loader) should specify the device for the root
1954	  file system.
1955
1956config CMDLINE_OVERRIDE
1957	bool "Built-in command line overrides boot loader arguments"
1958	depends on CMDLINE_BOOL
1959	---help---
1960	  Set this option to 'Y' to have the kernel ignore the boot loader
1961	  command line, and use ONLY the built-in command line.
1962
1963	  This is used to work around broken boot loaders.  This should
1964	  be set to 'N' under normal conditions.
1965
1966endmenu
1967
1968config ARCH_ENABLE_MEMORY_HOTPLUG
1969	def_bool y
1970	depends on X86_64 || (X86_32 && HIGHMEM)
1971
1972config ARCH_ENABLE_MEMORY_HOTREMOVE
1973	def_bool y
1974	depends on MEMORY_HOTPLUG
1975
1976config USE_PERCPU_NUMA_NODE_ID
1977	def_bool y
1978	depends on NUMA
1979
1980config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1981	def_bool y
1982	depends on X86_64 || X86_PAE
1983
1984config ARCH_ENABLE_HUGEPAGE_MIGRATION
1985	def_bool y
1986	depends on X86_64 && HUGETLB_PAGE && MIGRATION
1987
1988menu "Power management and ACPI options"
1989
1990config ARCH_HIBERNATION_HEADER
1991	def_bool y
1992	depends on X86_64 && HIBERNATION
1993
1994source "kernel/power/Kconfig"
1995
1996source "drivers/acpi/Kconfig"
1997
1998source "drivers/sfi/Kconfig"
1999
2000config X86_APM_BOOT
2001	def_bool y
2002	depends on APM
2003
2004menuconfig APM
2005	tristate "APM (Advanced Power Management) BIOS support"
2006	depends on X86_32 && PM_SLEEP
2007	---help---
2008	  APM is a BIOS specification for saving power using several different
2009	  techniques. This is mostly useful for battery powered laptops with
2010	  APM compliant BIOSes. If you say Y here, the system time will be
2011	  reset after a RESUME operation, the /proc/apm device will provide
2012	  battery status information, and user-space programs will receive
2013	  notification of APM "events" (e.g. battery status change).
2014
2015	  If you select "Y" here, you can disable actual use of the APM
2016	  BIOS by passing the "apm=off" option to the kernel at boot time.
2017
2018	  Note that the APM support is almost completely disabled for
2019	  machines with more than one CPU.
2020
2021	  In order to use APM, you will need supporting software. For location
2022	  and more information, read <file:Documentation/power/apm-acpi.txt>
2023	  and the Battery Powered Linux mini-HOWTO, available from
2024	  <http://www.tldp.org/docs.html#howto>.
2025
2026	  This driver does not spin down disk drives (see the hdparm(8)
2027	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2028	  VESA-compliant "green" monitors.
2029
2030	  This driver does not support the TI 4000M TravelMate and the ACER
2031	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2032	  desktop machines also don't have compliant BIOSes, and this driver
2033	  may cause those machines to panic during the boot phase.
2034
2035	  Generally, if you don't have a battery in your machine, there isn't
2036	  much point in using this driver and you should say N. If you get
2037	  random kernel OOPSes or reboots that don't seem to be related to
2038	  anything, try disabling/enabling this option (or disabling/enabling
2039	  APM in your BIOS).
2040
2041	  Some other things you should try when experiencing seemingly random,
2042	  "weird" problems:
2043
2044	  1) make sure that you have enough swap space and that it is
2045	  enabled.
2046	  2) pass the "no-hlt" option to the kernel
2047	  3) switch on floating point emulation in the kernel and pass
2048	  the "no387" option to the kernel
2049	  4) pass the "floppy=nodma" option to the kernel
2050	  5) pass the "mem=4M" option to the kernel (thereby disabling
2051	  all but the first 4 MB of RAM)
2052	  6) make sure that the CPU is not over clocked.
2053	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2054	  8) disable the cache from your BIOS settings
2055	  9) install a fan for the video card or exchange video RAM
2056	  10) install a better fan for the CPU
2057	  11) exchange RAM chips
2058	  12) exchange the motherboard.
2059
2060	  To compile this driver as a module, choose M here: the
2061	  module will be called apm.
2062
2063if APM
2064
2065config APM_IGNORE_USER_SUSPEND
2066	bool "Ignore USER SUSPEND"
2067	---help---
2068	  This option will ignore USER SUSPEND requests. On machines with a
2069	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2070	  series notebooks, it is necessary to say Y because of a BIOS bug.
2071
2072config APM_DO_ENABLE
2073	bool "Enable PM at boot time"
2074	---help---
2075	  Enable APM features at boot time. From page 36 of the APM BIOS
2076	  specification: "When disabled, the APM BIOS does not automatically
2077	  power manage devices, enter the Standby State, enter the Suspend
2078	  State, or take power saving steps in response to CPU Idle calls."
2079	  This driver will make CPU Idle calls when Linux is idle (unless this
2080	  feature is turned off -- see "Do CPU IDLE calls", below). This
2081	  should always save battery power, but more complicated APM features
2082	  will be dependent on your BIOS implementation. You may need to turn
2083	  this option off if your computer hangs at boot time when using APM
2084	  support, or if it beeps continuously instead of suspending. Turn
2085	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2086	  T400CDT. This is off by default since most machines do fine without
2087	  this feature.
2088
2089config APM_CPU_IDLE
2090	depends on CPU_IDLE
2091	bool "Make CPU Idle calls when idle"
2092	---help---
2093	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2094	  On some machines, this can activate improved power savings, such as
2095	  a slowed CPU clock rate, when the machine is idle. These idle calls
2096	  are made after the idle loop has run for some length of time (e.g.,
2097	  333 mS). On some machines, this will cause a hang at boot time or
2098	  whenever the CPU becomes idle. (On machines with more than one CPU,
2099	  this option does nothing.)
2100
2101config APM_DISPLAY_BLANK
2102	bool "Enable console blanking using APM"
2103	---help---
2104	  Enable console blanking using the APM. Some laptops can use this to
2105	  turn off the LCD backlight when the screen blanker of the Linux
2106	  virtual console blanks the screen. Note that this is only used by
2107	  the virtual console screen blanker, and won't turn off the backlight
2108	  when using the X Window system. This also doesn't have anything to
2109	  do with your VESA-compliant power-saving monitor. Further, this
2110	  option doesn't work for all laptops -- it might not turn off your
2111	  backlight at all, or it might print a lot of errors to the console,
2112	  especially if you are using gpm.
2113
2114config APM_ALLOW_INTS
2115	bool "Allow interrupts during APM BIOS calls"
2116	---help---
2117	  Normally we disable external interrupts while we are making calls to
2118	  the APM BIOS as a measure to lessen the effects of a badly behaving
2119	  BIOS implementation.  The BIOS should reenable interrupts if it
2120	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2121	  many of the newer IBM Thinkpads.  If you experience hangs when you
2122	  suspend, try setting this to Y.  Otherwise, say N.
2123
2124endif # APM
2125
2126source "drivers/cpufreq/Kconfig"
2127
2128source "drivers/cpuidle/Kconfig"
2129
2130source "drivers/idle/Kconfig"
2131
2132endmenu
2133
2134
2135menu "Bus options (PCI etc.)"
2136
2137config PCI
2138	bool "PCI support"
2139	default y
2140	---help---
2141	  Find out whether you have a PCI motherboard. PCI is the name of a
2142	  bus system, i.e. the way the CPU talks to the other stuff inside
2143	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2144	  VESA. If you have PCI, say Y, otherwise N.
2145
2146choice
2147	prompt "PCI access mode"
2148	depends on X86_32 && PCI
2149	default PCI_GOANY
2150	---help---
2151	  On PCI systems, the BIOS can be used to detect the PCI devices and
2152	  determine their configuration. However, some old PCI motherboards
2153	  have BIOS bugs and may crash if this is done. Also, some embedded
2154	  PCI-based systems don't have any BIOS at all. Linux can also try to
2155	  detect the PCI hardware directly without using the BIOS.
2156
2157	  With this option, you can specify how Linux should detect the
2158	  PCI devices. If you choose "BIOS", the BIOS will be used,
2159	  if you choose "Direct", the BIOS won't be used, and if you
2160	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2161	  If you choose "Any", the kernel will try MMCONFIG, then the
2162	  direct access method and falls back to the BIOS if that doesn't
2163	  work. If unsure, go with the default, which is "Any".
2164
2165config PCI_GOBIOS
2166	bool "BIOS"
2167
2168config PCI_GOMMCONFIG
2169	bool "MMConfig"
2170
2171config PCI_GODIRECT
2172	bool "Direct"
2173
2174config PCI_GOOLPC
2175	bool "OLPC XO-1"
2176	depends on OLPC
2177
2178config PCI_GOANY
2179	bool "Any"
2180
2181endchoice
2182
2183config PCI_BIOS
2184	def_bool y
2185	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2186
2187# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2188config PCI_DIRECT
2189	def_bool y
2190	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2191
2192config PCI_MMCONFIG
2193	def_bool y
2194	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2195
2196config PCI_OLPC
2197	def_bool y
2198	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2199
2200config PCI_XEN
2201	def_bool y
2202	depends on PCI && XEN
2203	select SWIOTLB_XEN
2204
2205config PCI_DOMAINS
2206	def_bool y
2207	depends on PCI
2208
2209config PCI_MMCONFIG
2210	bool "Support mmconfig PCI config space access"
2211	depends on X86_64 && PCI && ACPI
2212
2213config PCI_CNB20LE_QUIRK
2214	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2215	depends on PCI
2216	help
2217	  Read the PCI windows out of the CNB20LE host bridge. This allows
2218	  PCI hotplug to work on systems with the CNB20LE chipset which do
2219	  not have ACPI.
2220
2221	  There's no public spec for this chipset, and this functionality
2222	  is known to be incomplete.
2223
2224	  You should say N unless you know you need this.
2225
2226source "drivers/pci/pcie/Kconfig"
2227
2228source "drivers/pci/Kconfig"
2229
2230# x86_64 have no ISA slots, but can have ISA-style DMA.
2231config ISA_DMA_API
2232	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2233	default y
2234	help
2235	  Enables ISA-style DMA support for devices requiring such controllers.
2236	  If unsure, say Y.
2237
2238if X86_32
2239
2240config ISA
2241	bool "ISA support"
2242	---help---
2243	  Find out whether you have ISA slots on your motherboard.  ISA is the
2244	  name of a bus system, i.e. the way the CPU talks to the other stuff
2245	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2246	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2247	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2248
2249config EISA
2250	bool "EISA support"
2251	depends on ISA
2252	---help---
2253	  The Extended Industry Standard Architecture (EISA) bus was
2254	  developed as an open alternative to the IBM MicroChannel bus.
2255
2256	  The EISA bus provided some of the features of the IBM MicroChannel
2257	  bus while maintaining backward compatibility with cards made for
2258	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2259	  1995 when it was made obsolete by the PCI bus.
2260
2261	  Say Y here if you are building a kernel for an EISA-based machine.
2262
2263	  Otherwise, say N.
2264
2265source "drivers/eisa/Kconfig"
2266
2267config SCx200
2268	tristate "NatSemi SCx200 support"
2269	---help---
2270	  This provides basic support for National Semiconductor's
2271	  (now AMD's) Geode processors.  The driver probes for the
2272	  PCI-IDs of several on-chip devices, so its a good dependency
2273	  for other scx200_* drivers.
2274
2275	  If compiled as a module, the driver is named scx200.
2276
2277config SCx200HR_TIMER
2278	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2279	depends on SCx200
2280	default y
2281	---help---
2282	  This driver provides a clocksource built upon the on-chip
2283	  27MHz high-resolution timer.  Its also a workaround for
2284	  NSC Geode SC-1100's buggy TSC, which loses time when the
2285	  processor goes idle (as is done by the scheduler).  The
2286	  other workaround is idle=poll boot option.
2287
2288config OLPC
2289	bool "One Laptop Per Child support"
2290	depends on !X86_PAE
2291	select GPIOLIB
2292	select OF
2293	select OF_PROMTREE
2294	select IRQ_DOMAIN
2295	---help---
2296	  Add support for detecting the unique features of the OLPC
2297	  XO hardware.
2298
2299config OLPC_XO1_PM
2300	bool "OLPC XO-1 Power Management"
2301	depends on OLPC && MFD_CS5535 && PM_SLEEP
2302	select MFD_CORE
2303	---help---
2304	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2305
2306config OLPC_XO1_RTC
2307	bool "OLPC XO-1 Real Time Clock"
2308	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2309	---help---
2310	  Add support for the XO-1 real time clock, which can be used as a
2311	  programmable wakeup source.
2312
2313config OLPC_XO1_SCI
2314	bool "OLPC XO-1 SCI extras"
2315	depends on OLPC && OLPC_XO1_PM
2316	depends on INPUT=y
2317	select POWER_SUPPLY
2318	select GPIO_CS5535
2319	select MFD_CORE
2320	---help---
2321	  Add support for SCI-based features of the OLPC XO-1 laptop:
2322	   - EC-driven system wakeups
2323	   - Power button
2324	   - Ebook switch
2325	   - Lid switch
2326	   - AC adapter status updates
2327	   - Battery status updates
2328
2329config OLPC_XO15_SCI
2330	bool "OLPC XO-1.5 SCI extras"
2331	depends on OLPC && ACPI
2332	select POWER_SUPPLY
2333	---help---
2334	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2335	   - EC-driven system wakeups
2336	   - AC adapter status updates
2337	   - Battery status updates
2338
2339config ALIX
2340	bool "PCEngines ALIX System Support (LED setup)"
2341	select GPIOLIB
2342	---help---
2343	  This option enables system support for the PCEngines ALIX.
2344	  At present this just sets up LEDs for GPIO control on
2345	  ALIX2/3/6 boards.  However, other system specific setup should
2346	  get added here.
2347
2348	  Note: You must still enable the drivers for GPIO and LED support
2349	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2350
2351	  Note: You have to set alix.force=1 for boards with Award BIOS.
2352
2353config NET5501
2354	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2355	select GPIOLIB
2356	---help---
2357	  This option enables system support for the Soekris Engineering net5501.
2358
2359config GEOS
2360	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2361	select GPIOLIB
2362	depends on DMI
2363	---help---
2364	  This option enables system support for the Traverse Technologies GEOS.
2365
2366config TS5500
2367	bool "Technologic Systems TS-5500 platform support"
2368	depends on MELAN
2369	select CHECK_SIGNATURE
2370	select NEW_LEDS
2371	select LEDS_CLASS
2372	---help---
2373	  This option enables system support for the Technologic Systems TS-5500.
2374
2375endif # X86_32
2376
2377config AMD_NB
2378	def_bool y
2379	depends on CPU_SUP_AMD && PCI
2380
2381source "drivers/pcmcia/Kconfig"
2382
2383source "drivers/pci/hotplug/Kconfig"
2384
2385config RAPIDIO
2386	tristate "RapidIO support"
2387	depends on PCI
2388	default n
2389	help
2390	  If enabled this option will include drivers and the core
2391	  infrastructure code to support RapidIO interconnect devices.
2392
2393source "drivers/rapidio/Kconfig"
2394
2395config X86_SYSFB
2396	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2397	help
2398	  Firmwares often provide initial graphics framebuffers so the BIOS,
2399	  bootloader or kernel can show basic video-output during boot for
2400	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2401	  Extensions and EFI-framebuffers for this, which are mostly limited
2402	  to x86.
2403	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2404	  framebuffers so the new generic system-framebuffer drivers can be
2405	  used on x86. If the framebuffer is not compatible with the generic
2406	  modes, it is adverticed as fallback platform framebuffer so legacy
2407	  drivers like efifb, vesafb and uvesafb can pick it up.
2408	  If this option is not selected, all system framebuffers are always
2409	  marked as fallback platform framebuffers as usual.
2410
2411	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2412	  not be able to pick up generic system framebuffers if this option
2413	  is selected. You are highly encouraged to enable simplefb as
2414	  replacement if you select this option. simplefb can correctly deal
2415	  with generic system framebuffers. But you should still keep vesafb
2416	  and others enabled as fallback if a system framebuffer is
2417	  incompatible with simplefb.
2418
2419	  If unsure, say Y.
2420
2421endmenu
2422
2423
2424menu "Executable file formats / Emulations"
2425
2426source "fs/Kconfig.binfmt"
2427
2428config IA32_EMULATION
2429	bool "IA32 Emulation"
2430	depends on X86_64
2431	select BINFMT_ELF
2432	select COMPAT_BINFMT_ELF
2433	select HAVE_UID16
2434	---help---
2435	  Include code to run legacy 32-bit programs under a
2436	  64-bit kernel. You should likely turn this on, unless you're
2437	  100% sure that you don't have any 32-bit programs left.
2438
2439config IA32_AOUT
2440	tristate "IA32 a.out support"
2441	depends on IA32_EMULATION
2442	---help---
2443	  Support old a.out binaries in the 32bit emulation.
2444
2445config X86_X32
2446	bool "x32 ABI for 64-bit mode"
2447	depends on X86_64 && IA32_EMULATION
2448	---help---
2449	  Include code to run binaries for the x32 native 32-bit ABI
2450	  for 64-bit processors.  An x32 process gets access to the
2451	  full 64-bit register file and wide data path while leaving
2452	  pointers at 32 bits for smaller memory footprint.
2453
2454	  You will need a recent binutils (2.22 or later) with
2455	  elf32_x86_64 support enabled to compile a kernel with this
2456	  option set.
2457
2458config COMPAT
2459	def_bool y
2460	depends on IA32_EMULATION || X86_X32
2461	select ARCH_WANT_OLD_COMPAT_IPC
2462
2463if COMPAT
2464config COMPAT_FOR_U64_ALIGNMENT
2465	def_bool y
2466
2467config SYSVIPC_COMPAT
2468	def_bool y
2469	depends on SYSVIPC
2470
2471config KEYS_COMPAT
2472	def_bool y
2473	depends on KEYS
2474endif
2475
2476endmenu
2477
2478
2479config HAVE_ATOMIC_IOMAP
2480	def_bool y
2481	depends on X86_32
2482
2483config X86_DEV_DMA_OPS
2484	bool
2485	depends on X86_64 || STA2X11
2486
2487config X86_DMA_REMAP
2488	bool
2489	depends on STA2X11
2490
2491config PMC_ATOM
2492	def_bool y
2493        depends on PCI
2494
2495source "net/Kconfig"
2496
2497source "drivers/Kconfig"
2498
2499source "drivers/firmware/Kconfig"
2500
2501source "fs/Kconfig"
2502
2503source "arch/x86/Kconfig.debug"
2504
2505source "security/Kconfig"
2506
2507source "crypto/Kconfig"
2508
2509source "arch/x86/kvm/Kconfig"
2510
2511source "lib/Kconfig"
2512