Kconfig 76.6 KB
Newer Older
Sam Ravnborg's avatar
Sam Ravnborg committed
1
2
# Select 32 or 64 bit
config 64BIT
3
	bool "64-bit kernel" if ARCH = "x86"
4
	default ARCH != "i386"
Ingo Molnar's avatar
Ingo Molnar committed
5
	---help---
Sam Ravnborg's avatar
Sam Ravnborg committed
6
7
8
9
	  Say yes to build a 64-bit kernel - formerly known as x86_64
	  Say no to build a 32-bit kernel - formerly known as i386

config X86_32
10
11
	def_bool y
	depends on !64BIT
12
	select CLKSRC_I8253
13
	select HAVE_UID16
Sam Ravnborg's avatar
Sam Ravnborg committed
14
15

config X86_64
16
17
	def_bool y
	depends on 64BIT
18
	select X86_DEV_DMA_OPS
19
	select ARCH_USE_CMPXCHG_LOCKREF
20
21

### Arch settings
22
config X86
23
	def_bool y
24
	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25
	select ARCH_MIGHT_HAVE_PC_PARPORT
26
	select ARCH_MIGHT_HAVE_PC_SERIO
27
	select HAVE_AOUT if X86_32
28
	select HAVE_UNSTABLE_SCHED_CLOCK
29
	select ARCH_SUPPORTS_NUMA_BALANCING
Peter Zijlstra's avatar
Peter Zijlstra committed
30
	select ARCH_SUPPORTS_INT128 if X86_64
31
	select ARCH_WANTS_PROT_NUMA_PROT_NONE
Sam Ravnborg's avatar
Sam Ravnborg committed
32
	select HAVE_IDE
Mathieu Desnoyers's avatar
Mathieu Desnoyers committed
33
	select HAVE_OPROFILE
34
	select HAVE_PCSPKR_PLATFORM
Peter Zijlstra's avatar
Peter Zijlstra committed
35
	select HAVE_PERF_EVENTS
36
	select HAVE_IOREMAP_PROT
Mathieu Desnoyers's avatar
Mathieu Desnoyers committed
37
	select HAVE_KPROBES
38
	select HAVE_MEMBLOCK
Tejun Heo's avatar
Tejun Heo committed
39
	select HAVE_MEMBLOCK_NODE_MAP
40
	select ARCH_DISCARD_MEMBLOCK
41
	select ARCH_WANT_OPTIONAL_GPIOLIB
42
	select ARCH_WANT_FRAME_POINTERS
43
	select HAVE_DMA_ATTRS
44
	select HAVE_DMA_CONTIGUOUS if !SWIOTLB
45
	select HAVE_KRETPROBES
Mark Salter's avatar
Mark Salter committed
46
	select GENERIC_EARLY_IOREMAP
47
	select HAVE_OPTPROBES
48
	select HAVE_KPROBES_ON_FTRACE
49
	select HAVE_FTRACE_MCOUNT_RECORD
50
	select HAVE_FENTRY if X86_64
51
	select HAVE_C_RECORDMCOUNT
52
	select HAVE_DYNAMIC_FTRACE
53
	select HAVE_DYNAMIC_FTRACE_WITH_REGS
54
	select HAVE_FUNCTION_TRACER
55
	select HAVE_FUNCTION_GRAPH_TRACER
56
	select HAVE_FUNCTION_GRAPH_FP_TEST
57
	select HAVE_FUNCTION_TRACE_MCOUNT_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
69
70
	select HAVE_KERNEL_GZIP
	select HAVE_KERNEL_BZIP2
	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
83
	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
	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
Thomas Gleixner's avatar
Thomas Gleixner committed
92
93
	select GENERIC_IRQ_PROBE
	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 CLKEVT_I8253
100
	select ARCH_HAVE_NMI_SAFE_CMPXCHG
101
	select GENERIC_IOMAP
102
	select DCACHE_WORD_ACCESS
103
	select GENERIC_SMP_IDLE_THREAD
104
	select ARCH_WANT_IPC_PARSE_VERSION if X86_32
105
	select HAVE_ARCH_SECCOMP_FILTER
106
	select BUILDTIME_EXTABLE_SORT
Thomas Gleixner's avatar
Thomas Gleixner committed
107
	select GENERIC_CMOS_UPDATE
108
	select HAVE_ARCH_SOFT_DIRTY
Thomas Gleixner's avatar
Thomas Gleixner committed
109
110
	select CLOCKSOURCE_WATCHDOG
	select GENERIC_CLOCKEVENTS
111
	select ARCH_CLOCKSOURCE_DATA
Thomas Gleixner's avatar
Thomas Gleixner committed
112
	select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113
	select GENERIC_TIME_VSYSCALL
Thomas Gleixner's avatar
Thomas Gleixner committed
114
	select KTIME_SCALAR if X86_32
115
	select GENERIC_STRNCPY_FROM_USER
116
	select GENERIC_STRNLEN_USER
117
	select HAVE_CONTEXT_TRACKING if X86_64
118
	select HAVE_IRQ_TIME_ACCOUNTING
119
	select VIRT_TO_BUS
120
121
	select MODULES_USE_ELF_REL if X86_32
	select MODULES_USE_ELF_RELA if X86_64
122
	select CLONE_BACKWARDS if X86_32
123
	select ARCH_USE_BUILTIN_BSWAP
124
	select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
Al Viro's avatar
Al Viro committed
125
126
	select OLD_SIGACTION if X86_32
	select COMPAT_OLD_SIGACTION if IA32_EMULATION
127
	select RTC_LIB
128
	select HAVE_DEBUG_STACKOVERFLOW
129
	select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
130
	select HAVE_CC_STACKPROTECTOR
131
	select GENERIC_CPU_AUTOPROBE
132
	select HAVE_ARCH_AUDITSYSCALL
133

134
config INSTRUCTION_DECODER
135
136
	def_bool y
	depends on KPROBES || PERF_EVENTS || UPROBES
137

138
139
140
141
142
config OUTPUT_FORMAT
	string
	default "elf32-i386" if X86_32
	default "elf64-x86-64" if X86_64

143
config ARCH_DEFCONFIG
144
	string
145
146
	default "arch/x86/configs/i386_defconfig" if X86_32
	default "arch/x86/configs/x86_64_defconfig" if X86_64
147

148
config LOCKDEP_SUPPORT
149
	def_bool y
150
151

config STACKTRACE_SUPPORT
152
	def_bool y
153

154
155
156
config HAVE_LATENCYTOP_SUPPORT
	def_bool y

157
config MMU
158
	def_bool y
159
160
161
162

config SBUS
	bool

163
config NEED_DMA_MAP_STATE
164
165
	def_bool y
	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
166

167
config NEED_SG_DMA_LENGTH
168
	def_bool y
169

170
config GENERIC_ISA_DMA
171
172
	def_bool y
	depends on ISA_DMA_API
173
174

config GENERIC_BUG
175
	def_bool y
176
	depends on BUG
177
178
179
180
	select GENERIC_BUG_RELATIVE_POINTERS if X86_64

config GENERIC_BUG_RELATIVE_POINTERS
	bool
181
182

config GENERIC_HWEIGHT
183
	def_bool y
184
185

config ARCH_MAY_HAVE_PC_FDC
186
187
	def_bool y
	depends on ISA_DMA_API
188

189
config RWSEM_XCHGADD_ALGORITHM
190
	def_bool y
191
192
193
194

config GENERIC_CALIBRATE_DELAY
	def_bool y

195
196
197
config ARCH_HAS_CPU_RELAX
	def_bool y

198
199
200
config ARCH_HAS_CACHE_LINE_SIZE
	def_bool y

201
config HAVE_SETUP_PER_CPU_AREA
202
	def_bool y
203

204
205
206
207
config NEED_PER_CPU_EMBED_FIRST_CHUNK
	def_bool y

config NEED_PER_CPU_PAGE_FIRST_CHUNK
208
209
	def_bool y

210
211
212
config ARCH_HIBERNATION_POSSIBLE
	def_bool y

Johannes Berg's avatar
Johannes Berg committed
213
214
215
config ARCH_SUSPEND_POSSIBLE
	def_bool y

216
217
218
config ARCH_WANT_HUGE_PMD_SHARE
	def_bool y

219
220
221
config ARCH_WANT_GENERAL_HUGETLB
	def_bool y

222
223
224
225
226
227
228
229
config ZONE_DMA32
	bool
	default X86_64

config AUDIT_ARCH
	bool
	default X86_64

230
231
232
config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

Akinobu Mita's avatar
Akinobu Mita committed
233
234
235
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
	def_bool y

236
237
config HAVE_INTEL_TXT
	def_bool y
238
	depends on INTEL_IOMMU && ACPI
239

240
241
242
243
244
245
246
247
config X86_32_SMP
	def_bool y
	depends on X86_32 && SMP

config X86_64_SMP
	def_bool y
	depends on X86_64 && SMP

248
config X86_HT
Jan Beulich's avatar
Jan Beulich committed
249
	def_bool y
250
	depends on SMP
251

252
253
config X86_32_LAZY_GS
	def_bool y
254
	depends on X86_32 && !CC_STACKPROTECTOR
255

256
257
258
259
260
config ARCH_HWEIGHT_CFLAGS
	string
	default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
	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

261
262
263
config ARCH_SUPPORTS_UPROBES
	def_bool y

264
265
266
config FIX_EARLYCON_MEM
	def_bool y

267
source "init/Kconfig"
268
source "kernel/Kconfig.freezer"
269

270
271
menu "Processor type and features"

272
273
274
275
276
277
278
279
280
281
config ZONE_DMA
	bool "DMA memory allocation support" if EXPERT
	default y
	help
	  DMA memory allocation support allows devices with less than 32-bit
	  addressing to allocate within the first 16MB of address space.
	  Disable if no such devices will be used.

	  If unsure, say Y.

282
283
284
285
config SMP
	bool "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
286
287
	  a system with only one CPU, say N. If you have a system with more
	  than one CPU, say Y.
288

289
	  If you say N here, the kernel will run on uni- and multiprocessor
290
291
	  machines, but will use only one CPU of a multiprocessor machine. If
	  you say Y here, the kernel will run on many, but not all,
292
	  uniprocessor machines. On a uniprocessor machine, the kernel
293
294
295
296
297
298
299
300
301
302
303
	  will run faster if you say N here.

	  Note that if you say Y here and choose architecture "586" or
	  "Pentium" under "Processor family", the kernel will not work on 486
	  architectures. Similarly, multiprocessor kernels for the "PPro"
	  architecture may not work on all Pentium based boards.

	  People using multiprocessor machines who say Y here should also say
	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
	  Management" code will be disabled if you say Y here.

Paul Bolle's avatar
Paul Bolle committed
304
	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
305
306
307
308
309
	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
	  <http://www.tldp.org/docs.html#howto>.

	  If you don't know what to do here, say N.

Yinghai Lu's avatar
Yinghai Lu committed
310
311
config X86_X2APIC
	bool "Support x2apic"
312
	depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
Yinghai Lu's avatar
Yinghai Lu committed
313
314
315
316
317
318
319
320
	---help---
	  This enables x2apic support on CPUs that have this feature.

	  This allows 32-bit apic IDs (so it can support very large systems),
	  and accesses the local apic via MSRs not via mmio.

	  If you don't know what to do here, say N.

321
config X86_MPPARSE
322
	bool "Enable MPS table" if ACPI || SFI
323
	default y
324
	depends on X86_LOCAL_APIC
Ingo Molnar's avatar
Ingo Molnar committed
325
	---help---
326
327
328
	  For old smp systems that do not have proper acpi support. Newer systems
	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it

329
330
331
config X86_BIGSMP
	bool "Support for big SMP systems with more than 8 CPUs"
	depends on X86_32 && SMP
Ingo Molnar's avatar
Ingo Molnar committed
332
	---help---
333
	  This option is needed for the systems that have more than 8 CPUs
334

335
336
337
338
config GOLDFISH
       def_bool y
       depends on X86_GOLDFISH

339
if X86_32
340
341
342
config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
Ingo Molnar's avatar
Ingo Molnar committed
343
	---help---
344
345
346
347
	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

348
349
	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 32 bit x86 platforms:
350
		Goldfish (Android emulator)
351
352
353
		AMD Elan
		RDC R-321x SoC
		SGI 320/540 (Visual Workstation)
354
		STA2X11-based (e.g. Northville)
355
		Moorestown MID devices
356
357
358

	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
359
endif
360

361
362
363
364
365
366
367
368
369
370
371
if X86_64
config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
	---help---
	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold's avatar
Steffen Persvold committed
372
		Numascale NumaChip
373
374
375
376
377
378
		ScaleMP vSMP
		SGI Ultraviolet

	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
endif
379
380
# This is an alphabetically sorted list of 64 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
Steffen Persvold's avatar
Steffen Persvold committed
381
382
383
384
385
386
387
config X86_NUMACHIP
	bool "Numascale NumaChip"
	depends on X86_64
	depends on X86_EXTENDED_PLATFORM
	depends on NUMA
	depends on SMP
	depends on X86_X2APIC
388
	depends on PCI_MMCONFIG
Steffen Persvold's avatar
Steffen Persvold committed
389
390
391
392
	---help---
	  Adds support for Numascale NumaChip large-SMP systems. Needed to
	  enable more than ~168 cores.
	  If you don't have one of these, you should say N here.
393

394
395
config X86_VSMP
	bool "ScaleMP vSMP"
396
	select HYPERVISOR_GUEST
397
398
399
	select PARAVIRT
	depends on X86_64 && PCI
	depends on X86_EXTENDED_PLATFORM
400
	depends on SMP
Ingo Molnar's avatar
Ingo Molnar committed
401
	---help---
402
403
404
	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
	  supposed to run on these EM64T-based machines.  Only choose this option
	  if you have one of these machines.
405

406
407
408
config X86_UV
	bool "SGI Ultraviolet"
	depends on X86_64
409
	depends on X86_EXTENDED_PLATFORM
410
	depends on NUMA
411
	depends on X86_X2APIC
Ingo Molnar's avatar
Ingo Molnar committed
412
	---help---
413
414
415
	  This option is needed in order to support SGI Ultraviolet systems.
	  If you don't have one of these, you should say N here.

416
417
# Following is an alphabetically sorted list of 32 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
418

419
420
config X86_GOLDFISH
       bool "Goldfish (Virtual Platform)"
421
       depends on X86_EXTENDED_PLATFORM
422
423
424
425
426
       ---help---
	 Enable support for the Goldfish virtual platform used primarily
	 for Android development. Unless you are building for the Android
	 Goldfish emulator say N here.

427
428
429
430
431
432
config X86_INTEL_CE
	bool "CE4100 TV platform"
	depends on PCI
	depends on PCI_GODIRECT
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
433
	select X86_REBOOTFIXUPS
434
435
	select OF
	select OF_EARLY_FLATTREE
436
	select IRQ_DOMAIN
437
438
439
440
441
	---help---
	  Select for the Intel CE media processor (CE4100) SOC.
	  This option compiles in support for the CE4100 SOC for settop
	  boxes and media devices.

442
config X86_INTEL_MID
443
444
445
	bool "Intel MID platform support"
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
446
	depends on X86_PLATFORM_DEVICES
447
448
449
	depends on PCI
	depends on PCI_GOANY
	depends on X86_IO_APIC
450
	select SFI
451
	select I2C
452
	select DW_APB_TIMER
453
454
	select APB_TIMER
	select INTEL_SCU_IPC
455
	select MFD_INTEL_MSIC
456
	---help---
457
458
459
	  Select to build a kernel capable of supporting Intel MID (Mobile
	  Internet Device) platform systems which do not have the PCI legacy
	  interfaces. If you are building for a PC class system say N here.
460

461
462
	  Intel MID platforms are based on an Intel processor and chipset which
	  consume less power than most of the x86 derivatives.
463

464
465
466
467
config X86_INTEL_LPSS
	bool "Intel Low Power Subsystem Support"
	depends on ACPI
	select COMMON_CLK
468
	select PINCTRL
469
470
471
	---help---
	  Select to build support for Intel Low Power Subsystem such as
	  found on Intel Lynxpoint PCH. Selecting this option enables
472
473
	  things like clock tree (common clock framework) and pincontrol
	  which are needed by the LPSS peripheral drivers.
474

475
476
config X86_RDC321X
	bool "RDC R-321x SoC"
477
	depends on X86_32
478
479
480
481
482
483
484
485
	depends on X86_EXTENDED_PLATFORM
	select M486
	select X86_REBOOTFIXUPS
	---help---
	  This option is needed for RDC R-321x system-on-chip, also known
	  as R-8610-(G).
	  If you don't have one of these chips, you should say N here.

486
config X86_32_NON_STANDARD
487
488
	bool "Support non-standard 32-bit SMP architectures"
	depends on X86_32 && SMP
489
	depends on X86_EXTENDED_PLATFORM
Ingo Molnar's avatar
Ingo Molnar committed
490
	---help---
H. Peter Anvin's avatar
H. Peter Anvin committed
491
492
493
494
	  This option compiles in the bigsmp and STA2X11 default
	  subarchitectures.  It is intended for a generic binary
	  kernel. If you select them all, kernel will probe it one by
	  one and will fallback to default.
495

496
# Alphabetically sorted list of Non standard 32 bit platforms
497

498
config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich's avatar
Jan Beulich committed
499
	def_bool y
500
501
502
503
504
505
506
	# MCE code calls memory_failure():
	depends on X86_MCE
	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
	depends on X86_64 || !SPARSEMEM
	select ARCH_SUPPORTS_MEMORY_FAILURE

507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
config STA2X11
	bool "STA2X11 Companion Chip Support"
	depends on X86_32_NON_STANDARD && PCI
	select X86_DEV_DMA_OPS
	select X86_DMA_REMAP
	select SWIOTLB
	select MFD_STA2X11
	select ARCH_REQUIRE_GPIOLIB
	default n
	---help---
	  This adds support for boards based on the STA2X11 IO-Hub,
	  a.k.a. "ConneXt". The chip is used in place of the standard
	  PC chipset, so all "standard" peripherals are missing. If this
	  option is selected the kernel will still be able to boot on
	  standard PC machines.

523
524
525
526
527
528
529
530
531
532
533
534
535
config X86_32_IRIS
	tristate "Eurobraille/Iris poweroff module"
	depends on X86_32
	---help---
	  The Iris machines from EuroBraille do not have APM or ACPI support
	  to shut themselves down properly.  A special I/O sequence is
	  needed to do so, which is what this module does at
	  kernel shutdown.

	  This is only for Iris machines from EuroBraille.

	  If unused, say N.

536
config SCHED_OMIT_FRAME_POINTER
537
538
	def_bool y
	prompt "Single-depth WCHAN output"
539
	depends on X86
Ingo Molnar's avatar
Ingo Molnar committed
540
	---help---
541
542
543
544
545
546
547
	  Calculate simpler /proc/<PID>/wchan values. If this option
	  is disabled then wchan values will recurse back to the
	  caller function. This provides more accurate wchan values,
	  at the expense of slightly more scheduling overhead.

	  If in doubt, say "Y".

548
549
menuconfig HYPERVISOR_GUEST
	bool "Linux guest support"
Ingo Molnar's avatar
Ingo Molnar committed
550
	---help---
551
552
553
	  Say Y here to enable options for running Linux under various hyper-
	  visors. This option enables basic hypervisor detection and platform
	  setup.
554

555
556
	  If you say N, all options in this submenu will be skipped and
	  disabled, and Linux guest support won't be built in.
557

558
if HYPERVISOR_GUEST
559

560
561
config PARAVIRT
	bool "Enable paravirtualization code"
Ingo Molnar's avatar
Ingo Molnar committed
562
	---help---
563
564
565
566
567
	  This changes the kernel so it can modify itself when it is run
	  under a hypervisor, potentially improving performance significantly
	  over full virtualization.  However, when run without a hypervisor
	  the kernel is theoretically slower and slightly larger.

568
569
570
571
572
573
574
config PARAVIRT_DEBUG
	bool "paravirt-ops debugging"
	depends on PARAVIRT && DEBUG_KERNEL
	---help---
	  Enable to debug paravirt_ops internals.  Specifically, BUG if
	  a paravirt_op is missing when it is called.

575
576
config PARAVIRT_SPINLOCKS
	bool "Paravirtualization layer for spinlocks"
577
	depends on PARAVIRT && SMP
578
	select UNINLINE_SPIN_UNLOCK
579
580
581
582
583
	---help---
	  Paravirtualized spinlocks allow a pvops backend to replace the
	  spinlock implementation with something virtualization-friendly
	  (for example, block the virtual CPU rather than spinning).

584
585
	  It has a minimal impact on native kernels and gives a nice performance
	  benefit on paravirtualized KVM / Xen kernels.
586

587
	  If you are unsure how to answer this question, answer Y.
588

589
source "arch/x86/xen/Kconfig"
590

591
592
593
594
595
config KVM_GUEST
	bool "KVM Guest support (including kvmclock)"
	depends on PARAVIRT
	select PARAVIRT_CLOCK
	default y
Ingo Molnar's avatar
Ingo Molnar committed
596
	---help---
597
598
599
600
601
	  This option enables various optimizations for running under the KVM
	  hypervisor. It includes a paravirtualized clock, so that instead
	  of relying on a PIT (or probably other) emulation by the
	  underlying device model, the host provides the guest with
	  timing infrastructure such as time of day, and system time
602

603
604
605
606
607
608
609
610
611
config KVM_DEBUG_FS
	bool "Enable debug information for KVM Guests in debugfs"
	depends on KVM_GUEST && DEBUG_FS
	default n
	---help---
	  This option enables collection of various statistics for KVM guest.
	  Statistics are displayed in debugfs filesystem. Enabling this option
	  may incur significant overhead.

612
613
614
615
616
617
source "arch/x86/lguest/Kconfig"

config PARAVIRT_TIME_ACCOUNTING
	bool "Paravirtual steal time accounting"
	depends on PARAVIRT
	default n
Ingo Molnar's avatar
Ingo Molnar committed
618
	---help---
619
620
621
622
623
624
625
626
627
	  Select this option to enable fine granularity task steal time
	  accounting. Time spent executing other tasks in parallel with
	  the current vCPU is discounted from the vCPU power. To account for
	  that, there can be a small performance impact.

	  If in doubt, say N here.

config PARAVIRT_CLOCK
	bool
628

629
endif #HYPERVISOR_GUEST
630

631
config NO_BOOTMEM
Yinghai Lu's avatar
Yinghai Lu committed
632
	def_bool y
633

634
635
config MEMTEST
	bool "Memtest"
Ingo Molnar's avatar
Ingo Molnar committed
636
	---help---
Yinghai Lu's avatar
Yinghai Lu committed
637
	  This option adds a kernel parameter 'memtest', which allows memtest
638
	  to be set.
Ingo Molnar's avatar
Ingo Molnar committed
639
640
641
642
	        memtest=0, mean disabled; -- default
	        memtest=1, mean do 1 test pattern;
	        ...
	        memtest=4, mean do 4 test patterns.
Thomas Gleixner's avatar
Thomas Gleixner committed
643
	  If you are unsure how to answer this question, answer N.
644
645
646
647

source "arch/x86/Kconfig.cpu"

config HPET_TIMER
648
	def_bool X86_64
649
	prompt "HPET Timer Support" if X86_32
Ingo Molnar's avatar
Ingo Molnar committed
650
651
652
653
654
655
656
657
658
	---help---
	  Use the IA-PC HPET (High Precision Event Timer) to manage
	  time in preference to the PIT and RTC, if a HPET is
	  present.
	  HPET is the next generation timer replacing legacy 8254s.
	  The HPET provides a stable time base on SMP
	  systems, unlike the TSC, but it is more expensive to access,
	  as it is off-chip.  You can find the HPET spec at
	  <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
659

Ingo Molnar's avatar
Ingo Molnar committed
660
661
662
	  You can safely choose Y here.  However, HPET will only be
	  activated if the platform and the BIOS support this feature.
	  Otherwise the 8254 will be used for timing services.
663

Ingo Molnar's avatar
Ingo Molnar committed
664
	  Choose N to continue using the legacy 8254 timer.
665
666

config HPET_EMULATE_RTC
667
	def_bool y
668
	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
669

670
config APB_TIMER
671
672
       def_bool y if X86_INTEL_MID
       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
673
       select DW_APB_TIMER
674
       depends on X86_INTEL_MID && SFI
675
676
677
678
679
680
681
       help
         APB timer is the replacement for 8254, HPET on X86 MID platforms.
         The APBT provides a stable time base on SMP
         systems, unlike the TSC, but it is more expensive to access,
         as it is off-chip. APB timers are always running regardless of CPU
         C states, they are used as per CPU clockevent device when possible.

682
# Mark as expert because too many people got it wrong.
683
# The code disables itself when not needed.
684
685
config DMI
	default y
686
	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
687
	bool "Enable DMI scanning" if EXPERT
Ingo Molnar's avatar
Ingo Molnar committed
688
	---help---
689
690
691
692
693
	  Enabled scanning of DMI to identify machine quirks. Say Y
	  here unless you have verified that your setup is not
	  affected by entries in the DMI blacklist. Required by PNP
	  BIOS code.

694
config GART_IOMMU
695
	bool "Old AMD GART IOMMU support"
696
	select SWIOTLB
697
	depends on X86_64 && PCI && AMD_NB
Ingo Molnar's avatar
Ingo Molnar committed
698
	---help---
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
	  GART based hardware IOMMUs.

	  The GART supports full DMA access for devices with 32-bit access
	  limitations, on systems with more than 3 GB. This is usually needed
	  for USB, sound, many IDE/SATA chipsets and some other devices.

	  Newer systems typically have a modern AMD IOMMU, supported via
	  the CONFIG_AMD_IOMMU=y config option.

	  In normal configurations this driver is only active when needed:
	  there's more than 3 GB of memory and the system contains a
	  32-bit limited device.

	  If unsure, say Y.
714
715
716
717

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
	select SWIOTLB
718
	depends on X86_64 && PCI
Ingo Molnar's avatar
Ingo Molnar committed
719
	---help---
720
721
722
723
724
725
726
727
728
729
730
731
732
733
	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
	  systems. Needed to run systems with more than 3GB of memory
	  properly with 32-bit PCI devices that do not support DAC
	  (Double Address Cycle). Calgary also supports bus level
	  isolation, where all DMAs pass through the IOMMU.  This
	  prevents them from going anywhere except their intended
	  destination. This catches hard-to-find kernel bugs and
	  mis-behaving drivers and devices that do not use the DMA-API
	  properly to set up their DMA buffers.  The IOMMU can be
	  turned off at boot time with the iommu=off parameter.
	  Normally the kernel will make the right choice by itself.
	  If unsure, say Y.

config CALGARY_IOMMU_ENABLED_BY_DEFAULT
734
735
	def_bool y
	prompt "Should Calgary be enabled by default?"
736
	depends on CALGARY_IOMMU
Ingo Molnar's avatar
Ingo Molnar committed
737
	---help---
738
739
740
741
742
743
744
745
	  Should Calgary be enabled by default? if you choose 'y', Calgary
	  will be used (if it exists). If you choose 'n', Calgary will not be
	  used even if it exists. If you choose 'n' and would like to use
	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
	  If unsure, say Y.

# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
746
	def_bool y if X86_64
Ingo Molnar's avatar
Ingo Molnar committed
747
	---help---
748
	  Support for software bounce buffers used on x86-64 systems
749
750
751
752
	  which don't have a hardware IOMMU. Using this PCI devices
	  which can only access 32-bits of memory can be used on systems
	  with more than 3 GB of memory.
	  If unsure, say Y.
753

754
config IOMMU_HELPER
755
756
	def_bool y
	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
757

758
config MAXSMP
759
	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
760
	depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis's avatar
Mike Travis committed
761
	select CPUMASK_OFFSTACK
Ingo Molnar's avatar
Ingo Molnar committed
762
	---help---
763
	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
764
	  If unsure, say N.
765
766

config NR_CPUS
Mike Travis's avatar
Mike Travis committed
767
	int "Maximum number of CPUs" if SMP && !MAXSMP
768
	range 2 8 if SMP && X86_32 && !X86_BIGSMP
769
	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
770
	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
771
	default "1" if !SMP
772
	default "8192" if MAXSMP
H. Peter Anvin's avatar
H. Peter Anvin committed
773
	default "32" if SMP && X86_BIGSMP
774
	default "8" if SMP
Ingo Molnar's avatar
Ingo Molnar committed
775
	---help---
776
	  This allows you to specify the maximum number of CPUs which this
777
778
	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
	  supported value is 4096, otherwise the maximum value is 512.  The
779
780
781
782
783
784
785
	  minimum value which makes sense is 2.

	  This is purely to save memory - each supported CPU adds
	  approximately eight kilobytes to the kernel image.

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
786
	depends on X86_HT
Ingo Molnar's avatar
Ingo Molnar committed
787
	---help---
788
789
790
791
792
793
	  SMT scheduler support improves the CPU scheduler's decision making
	  when dealing with Intel Pentium 4 chips with HyperThreading at a
	  cost of slightly increased overhead in some places. If unsure say
	  N here.

config SCHED_MC
794
795
	def_bool y
	prompt "Multi-core scheduler support"
796
	depends on X86_HT
Ingo Molnar's avatar
Ingo Molnar committed
797
	---help---
798
799
800
801
802
803
804
805
	  Multi-core scheduler support improves the CPU scheduler's decision
	  making when dealing with multi-core CPU chips at a cost of slightly
	  increased overhead in some places. If unsure say N here.

source "kernel/Kconfig.preempt"

config X86_UP_APIC
	bool "Local APIC support on uniprocessors"
806
	depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
Ingo Molnar's avatar
Ingo Molnar committed
807
	---help---
808
809
810
811
812
813
814
815
816
817
818
819
	  A local APIC (Advanced Programmable Interrupt Controller) is an
	  integrated interrupt controller in the CPU. If you have a single-CPU
	  system which has a processor with a local APIC, you can say Y here to
	  enable and use it. If you say Y here even though your machine doesn't
	  have a local APIC, then the kernel will still run with no slowdown at
	  all. The local APIC supports CPU-generated self-interrupts (timer,
	  performance counters), and the NMI watchdog which detects hard
	  lockups.

config X86_UP_IOAPIC
	bool "IO-APIC support on uniprocessors"
	depends on X86_UP_APIC
Ingo Molnar's avatar
Ingo Molnar committed
820
	---help---
821
822
823
824
825
826
827
828
829
	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
	  SMP-capable replacement for PC-style interrupt controllers. Most
	  SMP systems and many recent uniprocessor systems have one.

	  If you have a single-CPU system with an IO-APIC, you can say Y here
	  to use it. If you say Y here even though your machine doesn't have
	  an IO-APIC, then the kernel will still run with no slowdown at all.

config X86_LOCAL_APIC
830
	def_bool y
831
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
832
833

config X86_IO_APIC
834
	def_bool y
835
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
836

837
838
839
config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
	bool "Reroute for broken boot IRQs"
	depends on X86_IO_APIC
Ingo Molnar's avatar
Ingo Molnar committed
840
	---help---
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
	  This option enables a workaround that fixes a source of
	  spurious interrupts. This is recommended when threaded
	  interrupt handling is used on systems where the generation of
	  superfluous "boot interrupts" cannot be disabled.

	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
	  kernel does during interrupt handling). On chipsets where this
	  boot IRQ generation cannot be disabled, this workaround keeps
	  the original IRQ line masked so that only the equivalent "boot
	  IRQ" is delivered to the CPUs. The workaround also tells the
	  kernel to set up the IRQ handler on the boot IRQ line. In this
	  way only one interrupt is delivered to the kernel. Otherwise
	  the spurious second interrupt may cause the kernel to bring
	  down (vital) interrupt lines.

	  Only affects "broken" chipsets. Interrupt sharing may be
	  increased on these systems.

860
config X86_MCE
861
	bool "Machine Check / overheating reporting"
862
	default y
863
	---help---
864
865
	  Machine Check support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, data corruption).
866
	  The action the kernel takes depends on the severity of the problem,
867
	  ranging from warning messages to halting the machine.
868

869
config X86_MCE_INTEL
870
871
	def_bool y
	prompt "Intel MCE features"
872
	depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar's avatar
Ingo Molnar committed
873
	---help---
874
875
876
877
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
878
879
	def_bool y
	prompt "AMD MCE features"
880
	depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar's avatar
Ingo Molnar committed
881
	---help---
882
883
884
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

885
config X86_ANCIENT_MCE
Jan Beulich's avatar
Jan Beulich committed
886
	bool "Support for old Pentium 5 / WinChip machine checks"
887
	depends on X86_32 && X86_MCE
888
889
	---help---
	  Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida's avatar
Masanari Iida committed
890
	  systems. These typically need to be enabled explicitly on the command
891
	  line.
892

893
894
config X86_MCE_THRESHOLD
	depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich's avatar
Jan Beulich committed
895
	def_bool y
896

897
config X86_MCE_INJECT
898
	depends on X86_MCE
899
900
901
902
903
904
	tristate "Machine check injector support"
	---help---
	  Provide support for injecting machine checks for testing purposes.
	  If you don't know what a machine check is and you don't do kernel
	  QA it is safe to say n.

905
906
config X86_THERMAL_VECTOR
	def_bool y
907
	depends on X86_MCE_INTEL
908

909
config VM86
910
	bool "Enable VM86 support" if EXPERT
911
912
	default y
	depends on X86_32
Ingo Molnar's avatar
Ingo Molnar committed
913
914
	---help---
	  This option is required by programs like DOSEMU to run 16-bit legacy
915
	  code on X86 processors. It also may be needed by software like
Ingo Molnar's avatar
Ingo Molnar committed
916
917
	  XFree86 to initialize some video cards via BIOS. Disabling this
	  option saves about 6k.
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936

config TOSHIBA
	tristate "Toshiba Laptop support"
	depends on X86_32
	---help---
	  This adds a driver to safely access the System Management Mode of
	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
	  not work on models with a Phoenix BIOS. The System Management Mode
	  is used to set the BIOS and power saving options on Toshiba portables.

	  For information on utilities to make use of this driver see the
	  Toshiba Linux utilities web site at:
	  <http://www.buzzard.org.uk/toshiba/>.

	  Say Y if you intend to run this kernel on a Toshiba portable.
	  Say N otherwise.

config I8K
	tristate "Dell laptop support"
937
	select HWMON
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
	---help---
	  This adds a driver to safely access the System Management Mode
	  of the CPU on the Dell Inspiron 8000. The System Management Mode
	  is used to read cpu temperature and cooling fan status and to
	  control the fans on the I8K portables.

	  This driver has been tested only on the Inspiron 8000 but it may
	  also work with other Dell laptops. You can force loading on other
	  models by passing the parameter `force=1' to the module. Use at
	  your own risk.

	  For information on utilities to make use of this driver see the
	  I8K Linux utilities web site at:
	  <http://people.debian.org/~dz/i8k/>

	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
	  Say N otherwise.

config X86_REBOOTFIXUPS
957
958
	bool "Enable X86 board specific fixups for reboot"
	depends on X86_32
959
960
961
962
963
964
965
966
	---help---
	  This enables chipset and/or board specific fixups to be done
	  in order to get reboot to work correctly. This is only needed on
	  some combinations of hardware and BIOS. The symptom, for which
	  this config is intended, is when reboot ends with a stalled/hung
	  system.

	  Currently, the only fixup is for the Geode machines using
967
	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
968
969
970
971
972
973

	  Say Y if you want to enable the fixup. Currently, it's safe to
	  enable this option even if you don't need it.
	  Say N otherwise.

config MICROCODE
974
	tristate "CPU microcode loading support"
975
	depends on CPU_SUP_AMD || CPU_SUP_INTEL
976
977
	select FW_LOADER
	---help---
978

979
	  If you say Y here, you will be able to update the microcode on
980
	  certain Intel and AMD processors. The Intel support is for the
981
982
983
984
	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
	  Xeon etc. The AMD support is for families 0x10 and later. You will
	  obviously need the actual microcode binary data itself which is not
	  shipped with the Linux kernel.
985

Peter Oruba's avatar
Peter Oruba committed
986
987
	  This option selects the general module only, you need to select
	  at least one vendor specific module as well.
988

989
990
	  To compile this driver as a module, choose M here: the module
	  will be called microcode.
991

Peter Oruba's avatar
Peter Oruba committed
992
config MICROCODE_INTEL
993
	bool "Intel microcode loading support"
Ingo Molnar's avatar
Ingo Molnar committed
994
995
996
997
998
999
1000
	depends on MICROCODE
	default MICROCODE
	select FW_LOADER
	---help---
	  This options enables microcode patch loading support for Intel
	  processors.

1001
1002
1003
	  For the current Intel microcode data package go to
	  <https://downloadcenter.intel.com> and search for
	  'Linux Processor Microcode Data File'.
Peter Oruba's avatar
Peter Oruba committed
1004

1005
config MICROCODE_AMD
1006
	bool "AMD microcode loading support"
Ingo Molnar's avatar
Ingo Molnar committed
1007
1008
1009
1010
1011
	depends on MICROCODE
	select FW_LOADER
	---help---
	  If you select this option, microcode patch loading support for AMD
	  processors will be enabled.
1012

Ingo Molnar's avatar
Ingo Molnar committed
1013
config MICROCODE_OLD_INTERFACE
1014
	def_bool y
1015
1016
	depends on MICROCODE

1017
config MICROCODE_INTEL_EARLY
1018
1019
1020
1021
1022
1023
	def_bool n

config MICROCODE_AMD_EARLY
	def_bool n

config MICROCODE_EARLY
1024
	bool "Early load microcode"
1025
	depends on MICROCODE=y && BLK_DEV_INITRD
1026
1027
	select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
	select MICROCODE_AMD_EARLY if MICROCODE_AMD
1028
1029
1030
1031
1032
1033
1034
	default y
	help
	  This option provides functionality to read additional microcode data
	  at the beginning of initrd image. The data tells kernel to load
	  microcode to CPU's as early as possible. No functional change if no
	  microcode data is glued to the initrd, therefore it's safe to say Y.

1035
1036
config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar's avatar
Ingo Molnar committed
1037
	---help---
1038
1039
1040
1041
1042
1043
1044
1045
	  This device gives privileged processes access to the x86
	  Model-Specific Registers (MSRs).  It is a character device with
	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
	  MSR accesses are directed to a specific CPU on multi-processor
	  systems.

config X86_CPUID
	tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar's avatar
Ingo Molnar committed
1046
	---help---
1047
1048
1049
1050
1051
1052
1053
	  This device gives processes access to the x86 CPUID instruction to
	  be executed on a specific processor.  It is a character device
	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
	  /dev/cpu/31/cpuid.

choice
	prompt "High Memory Support"
Jan Beulich's avatar
Jan Beulich committed
1054
	default HIGHMEM4G
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
	depends on X86_32

config NOHIGHMEM
	bool "off"
	---help---
	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
	  However, the address space of 32-bit x86 processors is only 4
	  Gigabytes large. That means that, if you have a large amount of
	  physical memory, not all of it can be "permanently mapped" by the
	  kernel. The physical memory that's not permanently mapped is called
	  "high memory".

	  If you are compiling a kernel which will never run on a machine with
	  more than 1 Gigabyte total physical RAM, answer "off" here (default
	  choice and suitable for most users). This will result in a "3GB/1GB"
	  split: 3GB are mapped so that each process sees a 3GB virtual memory
	  space and the remaining part of the 4GB virtual memory space is used
	  by the kernel to permanently map as much physical memory as
	  possible.

	  If the machine has between 1 and 4 Gigabytes physical RAM, then
	  answer "4GB" here.

	  If more than 4 Gigabytes is used then answer "64GB" here. This
	  selection turns Intel PAE (Physical Address Extension) mode on.
	  PAE implements 3-level paging on IA32 processors. PAE is fully
	  supported by Linux, PAE mode is implemented on all recent Intel
	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
	  then the kernel will not boot on CPUs that don't support PAE!

	  The actual amount of total physical memory will either be
	  auto detected or can be forced by using a kernel command line option
	  such as "mem=256M". (Try "man bootparam" or see the documentation of
	  your boot loader (lilo or loadlin) about how to pass options to the
	  kernel at boot time.)

	  If unsure, say "off".

config HIGHMEM4G
	bool "4GB"
Ingo Molnar's avatar
Ingo Molnar committed
1095
	---help---