Merge tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs
[deliverable/linux.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 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
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
14
15 config 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
22 config X86
23 def_bool y
24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select HAVE_AOUT if X86_32
26 select HAVE_UNSTABLE_SCHED_CLOCK
27 select ARCH_SUPPORTS_NUMA_BALANCING
28 select ARCH_WANTS_PROT_NUMA_PROT_NONE
29 select HAVE_IDE
30 select HAVE_OPROFILE
31 select HAVE_PCSPKR_PLATFORM
32 select HAVE_PERF_EVENTS
33 select HAVE_IOREMAP_PROT
34 select HAVE_KPROBES
35 select HAVE_MEMBLOCK
36 select HAVE_MEMBLOCK_NODE_MAP
37 select ARCH_DISCARD_MEMBLOCK
38 select ARCH_WANT_OPTIONAL_GPIOLIB
39 select ARCH_WANT_FRAME_POINTERS
40 select HAVE_DMA_ATTRS
41 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
42 select HAVE_KRETPROBES
43 select HAVE_OPTPROBES
44 select HAVE_KPROBES_ON_FTRACE
45 select HAVE_FTRACE_MCOUNT_RECORD
46 select HAVE_FENTRY if X86_64
47 select HAVE_C_RECORDMCOUNT
48 select HAVE_DYNAMIC_FTRACE
49 select HAVE_DYNAMIC_FTRACE_WITH_REGS
50 select HAVE_FUNCTION_TRACER
51 select HAVE_FUNCTION_GRAPH_TRACER
52 select HAVE_FUNCTION_GRAPH_FP_TEST
53 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
54 select HAVE_SYSCALL_TRACEPOINTS
55 select SYSCTL_EXCEPTION_TRACE
56 select HAVE_KVM
57 select HAVE_ARCH_KGDB
58 select HAVE_ARCH_TRACEHOOK
59 select HAVE_GENERIC_DMA_COHERENT if X86_32
60 select HAVE_EFFICIENT_UNALIGNED_ACCESS
61 select USER_STACKTRACE_SUPPORT
62 select HAVE_REGS_AND_STACK_ACCESS_API
63 select HAVE_DMA_API_DEBUG
64 select HAVE_KERNEL_GZIP
65 select HAVE_KERNEL_BZIP2
66 select HAVE_KERNEL_LZMA
67 select HAVE_KERNEL_XZ
68 select HAVE_KERNEL_LZO
69 select HAVE_KERNEL_LZ4
70 select HAVE_HW_BREAKPOINT
71 select HAVE_MIXED_BREAKPOINTS_REGS
72 select PERF_EVENTS
73 select HAVE_PERF_EVENTS_NMI
74 select HAVE_PERF_REGS
75 select HAVE_PERF_USER_STACK_DUMP
76 select HAVE_DEBUG_KMEMLEAK
77 select ANON_INODES
78 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
79 select HAVE_CMPXCHG_LOCAL
80 select HAVE_CMPXCHG_DOUBLE
81 select HAVE_ARCH_KMEMCHECK
82 select HAVE_USER_RETURN_NOTIFIER
83 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
84 select HAVE_ARCH_JUMP_LABEL
85 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
86 select SPARSE_IRQ
87 select GENERIC_FIND_FIRST_BIT
88 select GENERIC_IRQ_PROBE
89 select GENERIC_PENDING_IRQ if SMP
90 select GENERIC_IRQ_SHOW
91 select GENERIC_CLOCKEVENTS_MIN_ADJUST
92 select IRQ_FORCED_THREADING
93 select USE_GENERIC_SMP_HELPERS if SMP
94 select HAVE_BPF_JIT if X86_64
95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
96 select CLKEVT_I8253
97 select ARCH_HAVE_NMI_SAFE_CMPXCHG
98 select GENERIC_IOMAP
99 select DCACHE_WORD_ACCESS
100 select GENERIC_SMP_IDLE_THREAD
101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
102 select HAVE_ARCH_SECCOMP_FILTER
103 select BUILDTIME_EXTABLE_SORT
104 select GENERIC_CMOS_UPDATE
105 select HAVE_ARCH_SOFT_DIRTY
106 select CLOCKSOURCE_WATCHDOG
107 select GENERIC_CLOCKEVENTS
108 select ARCH_CLOCKSOURCE_DATA if X86_64
109 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
110 select GENERIC_TIME_VSYSCALL if X86_64
111 select KTIME_SCALAR if X86_32
112 select GENERIC_STRNCPY_FROM_USER
113 select GENERIC_STRNLEN_USER
114 select HAVE_CONTEXT_TRACKING if X86_64
115 select HAVE_IRQ_TIME_ACCOUNTING
116 select VIRT_TO_BUS
117 select MODULES_USE_ELF_REL if X86_32
118 select MODULES_USE_ELF_RELA if X86_64
119 select CLONE_BACKWARDS if X86_32
120 select ARCH_USE_BUILTIN_BSWAP
121 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
122 select OLD_SIGACTION if X86_32
123 select COMPAT_OLD_SIGACTION if IA32_EMULATION
124 select RTC_LIB
125 select HAVE_DEBUG_STACKOVERFLOW
126
127 config INSTRUCTION_DECODER
128 def_bool y
129 depends on KPROBES || PERF_EVENTS || UPROBES
130
131 config OUTPUT_FORMAT
132 string
133 default "elf32-i386" if X86_32
134 default "elf64-x86-64" if X86_64
135
136 config ARCH_DEFCONFIG
137 string
138 default "arch/x86/configs/i386_defconfig" if X86_32
139 default "arch/x86/configs/x86_64_defconfig" if X86_64
140
141 config LOCKDEP_SUPPORT
142 def_bool y
143
144 config STACKTRACE_SUPPORT
145 def_bool y
146
147 config HAVE_LATENCYTOP_SUPPORT
148 def_bool y
149
150 config MMU
151 def_bool y
152
153 config SBUS
154 bool
155
156 config NEED_DMA_MAP_STATE
157 def_bool y
158 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
159
160 config NEED_SG_DMA_LENGTH
161 def_bool y
162
163 config GENERIC_ISA_DMA
164 def_bool y
165 depends on ISA_DMA_API
166
167 config GENERIC_BUG
168 def_bool y
169 depends on BUG
170 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
171
172 config GENERIC_BUG_RELATIVE_POINTERS
173 bool
174
175 config GENERIC_HWEIGHT
176 def_bool y
177
178 config ARCH_MAY_HAVE_PC_FDC
179 def_bool y
180 depends on ISA_DMA_API
181
182 config RWSEM_XCHGADD_ALGORITHM
183 def_bool y
184
185 config GENERIC_CALIBRATE_DELAY
186 def_bool y
187
188 config ARCH_HAS_CPU_RELAX
189 def_bool y
190
191 config ARCH_HAS_CACHE_LINE_SIZE
192 def_bool y
193
194 config ARCH_HAS_CPU_AUTOPROBE
195 def_bool y
196
197 config HAVE_SETUP_PER_CPU_AREA
198 def_bool y
199
200 config NEED_PER_CPU_EMBED_FIRST_CHUNK
201 def_bool y
202
203 config NEED_PER_CPU_PAGE_FIRST_CHUNK
204 def_bool y
205
206 config ARCH_HIBERNATION_POSSIBLE
207 def_bool y
208
209 config ARCH_SUSPEND_POSSIBLE
210 def_bool y
211
212 config ARCH_WANT_HUGE_PMD_SHARE
213 def_bool y
214
215 config ARCH_WANT_GENERAL_HUGETLB
216 def_bool y
217
218 config ZONE_DMA32
219 bool
220 default X86_64
221
222 config AUDIT_ARCH
223 bool
224 default X86_64
225
226 config ARCH_SUPPORTS_OPTIMIZED_INLINING
227 def_bool y
228
229 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
230 def_bool y
231
232 config HAVE_INTEL_TXT
233 def_bool y
234 depends on INTEL_IOMMU && ACPI
235
236 config X86_32_SMP
237 def_bool y
238 depends on X86_32 && SMP
239
240 config X86_64_SMP
241 def_bool y
242 depends on X86_64 && SMP
243
244 config X86_HT
245 def_bool y
246 depends on SMP
247
248 config X86_32_LAZY_GS
249 def_bool y
250 depends on X86_32 && !CC_STACKPROTECTOR
251
252 config ARCH_HWEIGHT_CFLAGS
253 string
254 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
255 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
256
257 config ARCH_CPU_PROBE_RELEASE
258 def_bool y
259 depends on HOTPLUG_CPU
260
261 config ARCH_SUPPORTS_UPROBES
262 def_bool y
263
264 source "init/Kconfig"
265 source "kernel/Kconfig.freezer"
266
267 menu "Processor type and features"
268
269 config ZONE_DMA
270 bool "DMA memory allocation support" if EXPERT
271 default y
272 help
273 DMA memory allocation support allows devices with less than 32-bit
274 addressing to allocate within the first 16MB of address space.
275 Disable if no such devices will be used.
276
277 If unsure, say Y.
278
279 config SMP
280 bool "Symmetric multi-processing support"
281 ---help---
282 This enables support for systems with more than one CPU. If you have
283 a system with only one CPU, like most personal computers, say N. If
284 you have a system with more than one CPU, say Y.
285
286 If you say N here, the kernel will run on single and multiprocessor
287 machines, but will use only one CPU of a multiprocessor machine. If
288 you say Y here, the kernel will run on many, but not all,
289 singleprocessor machines. On a singleprocessor machine, the kernel
290 will run faster if you say N here.
291
292 Note that if you say Y here and choose architecture "586" or
293 "Pentium" under "Processor family", the kernel will not work on 486
294 architectures. Similarly, multiprocessor kernels for the "PPro"
295 architecture may not work on all Pentium based boards.
296
297 People using multiprocessor machines who say Y here should also say
298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
299 Management" code will be disabled if you say Y here.
300
301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
303 <http://www.tldp.org/docs.html#howto>.
304
305 If you don't know what to do here, say N.
306
307 config X86_X2APIC
308 bool "Support x2apic"
309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
310 ---help---
311 This enables x2apic support on CPUs that have this feature.
312
313 This allows 32-bit apic IDs (so it can support very large systems),
314 and accesses the local apic via MSRs not via mmio.
315
316 If you don't know what to do here, say N.
317
318 config X86_MPPARSE
319 bool "Enable MPS table" if ACPI || SFI
320 default y
321 depends on X86_LOCAL_APIC
322 ---help---
323 For old smp systems that do not have proper acpi support. Newer systems
324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
325
326 config X86_BIGSMP
327 bool "Support for big SMP systems with more than 8 CPUs"
328 depends on X86_32 && SMP
329 ---help---
330 This option is needed for the systems that have more than 8 CPUs
331
332 config GOLDFISH
333 def_bool y
334 depends on X86_GOLDFISH
335
336 if X86_32
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
339 default y
340 ---help---
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
343 systems out there.)
344
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
347 Goldfish (Android emulator)
348 AMD Elan
349 NUMAQ (IBM/Sequent)
350 RDC R-321x SoC
351 SGI 320/540 (Visual Workstation)
352 STA2X11-based (e.g. Northville)
353 Summit/EXA (IBM x440)
354 Unisys ES7000 IA32 series
355 Moorestown MID devices
356
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
359 endif
360
361 if X86_64
362 config 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) 64 bit x86 platforms:
372 Numascale NumaChip
373 ScaleMP vSMP
374 SGI Ultraviolet
375
376 If you have one of these systems, or if you want to build a
377 generic distribution kernel, say Y here - otherwise say N.
378 endif
379 # This is an alphabetically sorted list of 64 bit extended platforms
380 # Please maintain the alphabetic order if and when there are additions
381 config X86_NUMACHIP
382 bool "Numascale NumaChip"
383 depends on X86_64
384 depends on X86_EXTENDED_PLATFORM
385 depends on NUMA
386 depends on SMP
387 depends on X86_X2APIC
388 depends on PCI_MMCONFIG
389 ---help---
390 Adds support for Numascale NumaChip large-SMP systems. Needed to
391 enable more than ~168 cores.
392 If you don't have one of these, you should say N here.
393
394 config X86_VSMP
395 bool "ScaleMP vSMP"
396 select HYPERVISOR_GUEST
397 select PARAVIRT
398 depends on X86_64 && PCI
399 depends on X86_EXTENDED_PLATFORM
400 depends on SMP
401 ---help---
402 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
403 supposed to run on these EM64T-based machines. Only choose this option
404 if you have one of these machines.
405
406 config X86_UV
407 bool "SGI Ultraviolet"
408 depends on X86_64
409 depends on X86_EXTENDED_PLATFORM
410 depends on NUMA
411 depends on X86_X2APIC
412 ---help---
413 This option is needed in order to support SGI Ultraviolet systems.
414 If you don't have one of these, you should say N here.
415
416 # Following is an alphabetically sorted list of 32 bit extended platforms
417 # Please maintain the alphabetic order if and when there are additions
418
419 config X86_GOLDFISH
420 bool "Goldfish (Virtual Platform)"
421 depends on X86_32
422 depends on X86_EXTENDED_PLATFORM
423 ---help---
424 Enable support for the Goldfish virtual platform used primarily
425 for Android development. Unless you are building for the Android
426 Goldfish emulator say N here.
427
428 config X86_INTEL_CE
429 bool "CE4100 TV platform"
430 depends on PCI
431 depends on PCI_GODIRECT
432 depends on X86_32
433 depends on X86_EXTENDED_PLATFORM
434 select X86_REBOOTFIXUPS
435 select OF
436 select OF_EARLY_FLATTREE
437 select IRQ_DOMAIN
438 ---help---
439 Select for the Intel CE media processor (CE4100) SOC.
440 This option compiles in support for the CE4100 SOC for settop
441 boxes and media devices.
442
443 config X86_WANT_INTEL_MID
444 bool "Intel MID platform support"
445 depends on X86_32
446 depends on X86_EXTENDED_PLATFORM
447 ---help---
448 Select to build a kernel capable of supporting Intel MID platform
449 systems which do not have the PCI legacy interfaces (Moorestown,
450 Medfield). If you are building for a PC class system say N here.
451
452 if X86_WANT_INTEL_MID
453
454 config X86_INTEL_MID
455 bool
456
457 config X86_MDFLD
458 bool "Medfield MID platform"
459 depends on PCI
460 depends on PCI_GOANY
461 depends on X86_IO_APIC
462 select X86_INTEL_MID
463 select SFI
464 select DW_APB_TIMER
465 select APB_TIMER
466 select I2C
467 select SPI
468 select INTEL_SCU_IPC
469 select X86_PLATFORM_DEVICES
470 select MFD_INTEL_MSIC
471 ---help---
472 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
473 Internet Device(MID) platform.
474 Unlike standard x86 PCs, Medfield does not have many legacy devices
475 nor standard legacy replacement devices/features. e.g. Medfield does
476 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
477
478 endif
479
480 config X86_INTEL_LPSS
481 bool "Intel Low Power Subsystem Support"
482 depends on ACPI
483 select COMMON_CLK
484 ---help---
485 Select to build support for Intel Low Power Subsystem such as
486 found on Intel Lynxpoint PCH. Selecting this option enables
487 things like clock tree (common clock framework) which are needed
488 by the LPSS peripheral drivers.
489
490 config X86_RDC321X
491 bool "RDC R-321x SoC"
492 depends on X86_32
493 depends on X86_EXTENDED_PLATFORM
494 select M486
495 select X86_REBOOTFIXUPS
496 ---help---
497 This option is needed for RDC R-321x system-on-chip, also known
498 as R-8610-(G).
499 If you don't have one of these chips, you should say N here.
500
501 config X86_32_NON_STANDARD
502 bool "Support non-standard 32-bit SMP architectures"
503 depends on X86_32 && SMP
504 depends on X86_EXTENDED_PLATFORM
505 ---help---
506 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
507 STA2X11, default subarchitectures. It is intended for a generic
508 binary kernel. If you select them all, kernel will probe it
509 one by one and will fallback to default.
510
511 # Alphabetically sorted list of Non standard 32 bit platforms
512
513 config X86_NUMAQ
514 bool "NUMAQ (IBM/Sequent)"
515 depends on X86_32_NON_STANDARD
516 depends on PCI
517 select NUMA
518 select X86_MPPARSE
519 ---help---
520 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
521 NUMA multiquad box. This changes the way that processors are
522 bootstrapped, and uses Clustered Logical APIC addressing mode instead
523 of Flat Logical. You will need a new lynxer.elf file to flash your
524 firmware with - send email to <Martin.Bligh@us.ibm.com>.
525
526 config X86_SUPPORTS_MEMORY_FAILURE
527 def_bool y
528 # MCE code calls memory_failure():
529 depends on X86_MCE
530 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
531 depends on !X86_NUMAQ
532 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
533 depends on X86_64 || !SPARSEMEM
534 select ARCH_SUPPORTS_MEMORY_FAILURE
535
536 config X86_VISWS
537 bool "SGI 320/540 (Visual Workstation)"
538 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
539 depends on X86_32_NON_STANDARD
540 ---help---
541 The SGI Visual Workstation series is an IA32-based workstation
542 based on SGI systems chips with some legacy PC hardware attached.
543
544 Say Y here to create a kernel to run on the SGI 320 or 540.
545
546 A kernel compiled for the Visual Workstation will run on general
547 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
548
549 config STA2X11
550 bool "STA2X11 Companion Chip Support"
551 depends on X86_32_NON_STANDARD && PCI
552 select X86_DEV_DMA_OPS
553 select X86_DMA_REMAP
554 select SWIOTLB
555 select MFD_STA2X11
556 select ARCH_REQUIRE_GPIOLIB
557 default n
558 ---help---
559 This adds support for boards based on the STA2X11 IO-Hub,
560 a.k.a. "ConneXt". The chip is used in place of the standard
561 PC chipset, so all "standard" peripherals are missing. If this
562 option is selected the kernel will still be able to boot on
563 standard PC machines.
564
565 config X86_SUMMIT
566 bool "Summit/EXA (IBM x440)"
567 depends on X86_32_NON_STANDARD
568 ---help---
569 This option is needed for IBM systems that use the Summit/EXA chipset.
570 In particular, it is needed for the x440.
571
572 config X86_ES7000
573 bool "Unisys ES7000 IA32 series"
574 depends on X86_32_NON_STANDARD && X86_BIGSMP
575 ---help---
576 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
577 supposed to run on an IA32-based Unisys ES7000 system.
578
579 config X86_32_IRIS
580 tristate "Eurobraille/Iris poweroff module"
581 depends on X86_32
582 ---help---
583 The Iris machines from EuroBraille do not have APM or ACPI support
584 to shut themselves down properly. A special I/O sequence is
585 needed to do so, which is what this module does at
586 kernel shutdown.
587
588 This is only for Iris machines from EuroBraille.
589
590 If unused, say N.
591
592 config SCHED_OMIT_FRAME_POINTER
593 def_bool y
594 prompt "Single-depth WCHAN output"
595 depends on X86
596 ---help---
597 Calculate simpler /proc/<PID>/wchan values. If this option
598 is disabled then wchan values will recurse back to the
599 caller function. This provides more accurate wchan values,
600 at the expense of slightly more scheduling overhead.
601
602 If in doubt, say "Y".
603
604 menuconfig HYPERVISOR_GUEST
605 bool "Linux guest support"
606 ---help---
607 Say Y here to enable options for running Linux under various hyper-
608 visors. This option enables basic hypervisor detection and platform
609 setup.
610
611 If you say N, all options in this submenu will be skipped and
612 disabled, and Linux guest support won't be built in.
613
614 if HYPERVISOR_GUEST
615
616 config PARAVIRT
617 bool "Enable paravirtualization code"
618 ---help---
619 This changes the kernel so it can modify itself when it is run
620 under a hypervisor, potentially improving performance significantly
621 over full virtualization. However, when run without a hypervisor
622 the kernel is theoretically slower and slightly larger.
623
624 config PARAVIRT_DEBUG
625 bool "paravirt-ops debugging"
626 depends on PARAVIRT && DEBUG_KERNEL
627 ---help---
628 Enable to debug paravirt_ops internals. Specifically, BUG if
629 a paravirt_op is missing when it is called.
630
631 config PARAVIRT_SPINLOCKS
632 bool "Paravirtualization layer for spinlocks"
633 depends on PARAVIRT && SMP
634 select UNINLINE_SPIN_UNLOCK
635 ---help---
636 Paravirtualized spinlocks allow a pvops backend to replace the
637 spinlock implementation with something virtualization-friendly
638 (for example, block the virtual CPU rather than spinning).
639
640 Unfortunately the downside is an up to 5% performance hit on
641 native kernels, with various workloads.
642
643 If you are unsure how to answer this question, answer N.
644
645 source "arch/x86/xen/Kconfig"
646
647 config KVM_GUEST
648 bool "KVM Guest support (including kvmclock)"
649 depends on PARAVIRT
650 select PARAVIRT_CLOCK
651 default y
652 ---help---
653 This option enables various optimizations for running under the KVM
654 hypervisor. It includes a paravirtualized clock, so that instead
655 of relying on a PIT (or probably other) emulation by the
656 underlying device model, the host provides the guest with
657 timing infrastructure such as time of day, and system time
658
659 config KVM_DEBUG_FS
660 bool "Enable debug information for KVM Guests in debugfs"
661 depends on KVM_GUEST && DEBUG_FS
662 default n
663 ---help---
664 This option enables collection of various statistics for KVM guest.
665 Statistics are displayed in debugfs filesystem. Enabling this option
666 may incur significant overhead.
667
668 source "arch/x86/lguest/Kconfig"
669
670 config PARAVIRT_TIME_ACCOUNTING
671 bool "Paravirtual steal time accounting"
672 depends on PARAVIRT
673 default n
674 ---help---
675 Select this option to enable fine granularity task steal time
676 accounting. Time spent executing other tasks in parallel with
677 the current vCPU is discounted from the vCPU power. To account for
678 that, there can be a small performance impact.
679
680 If in doubt, say N here.
681
682 config PARAVIRT_CLOCK
683 bool
684
685 endif #HYPERVISOR_GUEST
686
687 config NO_BOOTMEM
688 def_bool y
689
690 config MEMTEST
691 bool "Memtest"
692 ---help---
693 This option adds a kernel parameter 'memtest', which allows memtest
694 to be set.
695 memtest=0, mean disabled; -- default
696 memtest=1, mean do 1 test pattern;
697 ...
698 memtest=4, mean do 4 test patterns.
699 If you are unsure how to answer this question, answer N.
700
701 config X86_SUMMIT_NUMA
702 def_bool y
703 depends on X86_32 && NUMA && X86_32_NON_STANDARD
704
705 config X86_CYCLONE_TIMER
706 def_bool y
707 depends on X86_SUMMIT
708
709 source "arch/x86/Kconfig.cpu"
710
711 config HPET_TIMER
712 def_bool X86_64
713 prompt "HPET Timer Support" if X86_32
714 ---help---
715 Use the IA-PC HPET (High Precision Event Timer) to manage
716 time in preference to the PIT and RTC, if a HPET is
717 present.
718 HPET is the next generation timer replacing legacy 8254s.
719 The HPET provides a stable time base on SMP
720 systems, unlike the TSC, but it is more expensive to access,
721 as it is off-chip. You can find the HPET spec at
722 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
723
724 You can safely choose Y here. However, HPET will only be
725 activated if the platform and the BIOS support this feature.
726 Otherwise the 8254 will be used for timing services.
727
728 Choose N to continue using the legacy 8254 timer.
729
730 config HPET_EMULATE_RTC
731 def_bool y
732 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
733
734 config APB_TIMER
735 def_bool y if X86_INTEL_MID
736 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
737 select DW_APB_TIMER
738 depends on X86_INTEL_MID && SFI
739 help
740 APB timer is the replacement for 8254, HPET on X86 MID platforms.
741 The APBT provides a stable time base on SMP
742 systems, unlike the TSC, but it is more expensive to access,
743 as it is off-chip. APB timers are always running regardless of CPU
744 C states, they are used as per CPU clockevent device when possible.
745
746 # Mark as expert because too many people got it wrong.
747 # The code disables itself when not needed.
748 config DMI
749 default y
750 bool "Enable DMI scanning" if EXPERT
751 ---help---
752 Enabled scanning of DMI to identify machine quirks. Say Y
753 here unless you have verified that your setup is not
754 affected by entries in the DMI blacklist. Required by PNP
755 BIOS code.
756
757 config GART_IOMMU
758 bool "GART IOMMU support" if EXPERT
759 default y
760 select SWIOTLB
761 depends on X86_64 && PCI && AMD_NB
762 ---help---
763 Support for full DMA access of devices with 32bit memory access only
764 on systems with more than 3GB. This is usually needed for USB,
765 sound, many IDE/SATA chipsets and some other devices.
766 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
767 based hardware IOMMU and a software bounce buffer based IOMMU used
768 on Intel systems and as fallback.
769 The code is only active when needed (enough memory and limited
770 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
771 too.
772
773 config CALGARY_IOMMU
774 bool "IBM Calgary IOMMU support"
775 select SWIOTLB
776 depends on X86_64 && PCI
777 ---help---
778 Support for hardware IOMMUs in IBM's xSeries x366 and x460
779 systems. Needed to run systems with more than 3GB of memory
780 properly with 32-bit PCI devices that do not support DAC
781 (Double Address Cycle). Calgary also supports bus level
782 isolation, where all DMAs pass through the IOMMU. This
783 prevents them from going anywhere except their intended
784 destination. This catches hard-to-find kernel bugs and
785 mis-behaving drivers and devices that do not use the DMA-API
786 properly to set up their DMA buffers. The IOMMU can be
787 turned off at boot time with the iommu=off parameter.
788 Normally the kernel will make the right choice by itself.
789 If unsure, say Y.
790
791 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
792 def_bool y
793 prompt "Should Calgary be enabled by default?"
794 depends on CALGARY_IOMMU
795 ---help---
796 Should Calgary be enabled by default? if you choose 'y', Calgary
797 will be used (if it exists). If you choose 'n', Calgary will not be
798 used even if it exists. If you choose 'n' and would like to use
799 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
800 If unsure, say Y.
801
802 # need this always selected by IOMMU for the VIA workaround
803 config SWIOTLB
804 def_bool y if X86_64
805 ---help---
806 Support for software bounce buffers used on x86-64 systems
807 which don't have a hardware IOMMU. Using this PCI devices
808 which can only access 32-bits of memory can be used on systems
809 with more than 3 GB of memory.
810 If unsure, say Y.
811
812 config IOMMU_HELPER
813 def_bool y
814 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
815
816 config MAXSMP
817 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
818 depends on X86_64 && SMP && DEBUG_KERNEL
819 select CPUMASK_OFFSTACK
820 ---help---
821 Enable maximum number of CPUS and NUMA Nodes for this architecture.
822 If unsure, say N.
823
824 config NR_CPUS
825 int "Maximum number of CPUs" if SMP && !MAXSMP
826 range 2 8 if SMP && X86_32 && !X86_BIGSMP
827 range 2 512 if SMP && !MAXSMP
828 default "1" if !SMP
829 default "4096" if MAXSMP
830 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
831 default "8" if SMP
832 ---help---
833 This allows you to specify the maximum number of CPUs which this
834 kernel will support. The maximum supported value is 512 and the
835 minimum value which makes sense is 2.
836
837 This is purely to save memory - each supported CPU adds
838 approximately eight kilobytes to the kernel image.
839
840 config SCHED_SMT
841 bool "SMT (Hyperthreading) scheduler support"
842 depends on X86_HT
843 ---help---
844 SMT scheduler support improves the CPU scheduler's decision making
845 when dealing with Intel Pentium 4 chips with HyperThreading at a
846 cost of slightly increased overhead in some places. If unsure say
847 N here.
848
849 config SCHED_MC
850 def_bool y
851 prompt "Multi-core scheduler support"
852 depends on X86_HT
853 ---help---
854 Multi-core scheduler support improves the CPU scheduler's decision
855 making when dealing with multi-core CPU chips at a cost of slightly
856 increased overhead in some places. If unsure say N here.
857
858 source "kernel/Kconfig.preempt"
859
860 config X86_UP_APIC
861 bool "Local APIC support on uniprocessors"
862 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
863 ---help---
864 A local APIC (Advanced Programmable Interrupt Controller) is an
865 integrated interrupt controller in the CPU. If you have a single-CPU
866 system which has a processor with a local APIC, you can say Y here to
867 enable and use it. If you say Y here even though your machine doesn't
868 have a local APIC, then the kernel will still run with no slowdown at
869 all. The local APIC supports CPU-generated self-interrupts (timer,
870 performance counters), and the NMI watchdog which detects hard
871 lockups.
872
873 config X86_UP_IOAPIC
874 bool "IO-APIC support on uniprocessors"
875 depends on X86_UP_APIC
876 ---help---
877 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
878 SMP-capable replacement for PC-style interrupt controllers. Most
879 SMP systems and many recent uniprocessor systems have one.
880
881 If you have a single-CPU system with an IO-APIC, you can say Y here
882 to use it. If you say Y here even though your machine doesn't have
883 an IO-APIC, then the kernel will still run with no slowdown at all.
884
885 config X86_LOCAL_APIC
886 def_bool y
887 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
888
889 config X86_IO_APIC
890 def_bool y
891 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
892
893 config X86_VISWS_APIC
894 def_bool y
895 depends on X86_32 && X86_VISWS
896
897 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
898 bool "Reroute for broken boot IRQs"
899 depends on X86_IO_APIC
900 ---help---
901 This option enables a workaround that fixes a source of
902 spurious interrupts. This is recommended when threaded
903 interrupt handling is used on systems where the generation of
904 superfluous "boot interrupts" cannot be disabled.
905
906 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
907 entry in the chipset's IO-APIC is masked (as, e.g. the RT
908 kernel does during interrupt handling). On chipsets where this
909 boot IRQ generation cannot be disabled, this workaround keeps
910 the original IRQ line masked so that only the equivalent "boot
911 IRQ" is delivered to the CPUs. The workaround also tells the
912 kernel to set up the IRQ handler on the boot IRQ line. In this
913 way only one interrupt is delivered to the kernel. Otherwise
914 the spurious second interrupt may cause the kernel to bring
915 down (vital) interrupt lines.
916
917 Only affects "broken" chipsets. Interrupt sharing may be
918 increased on these systems.
919
920 config X86_MCE
921 bool "Machine Check / overheating reporting"
922 default y
923 ---help---
924 Machine Check support allows the processor to notify the
925 kernel if it detects a problem (e.g. overheating, data corruption).
926 The action the kernel takes depends on the severity of the problem,
927 ranging from warning messages to halting the machine.
928
929 config X86_MCE_INTEL
930 def_bool y
931 prompt "Intel MCE features"
932 depends on X86_MCE && X86_LOCAL_APIC
933 ---help---
934 Additional support for intel specific MCE features such as
935 the thermal monitor.
936
937 config X86_MCE_AMD
938 def_bool y
939 prompt "AMD MCE features"
940 depends on X86_MCE && X86_LOCAL_APIC
941 ---help---
942 Additional support for AMD specific MCE features such as
943 the DRAM Error Threshold.
944
945 config X86_ANCIENT_MCE
946 bool "Support for old Pentium 5 / WinChip machine checks"
947 depends on X86_32 && X86_MCE
948 ---help---
949 Include support for machine check handling on old Pentium 5 or WinChip
950 systems. These typically need to be enabled explicitely on the command
951 line.
952
953 config X86_MCE_THRESHOLD
954 depends on X86_MCE_AMD || X86_MCE_INTEL
955 def_bool y
956
957 config X86_MCE_INJECT
958 depends on X86_MCE
959 tristate "Machine check injector support"
960 ---help---
961 Provide support for injecting machine checks for testing purposes.
962 If you don't know what a machine check is and you don't do kernel
963 QA it is safe to say n.
964
965 config X86_THERMAL_VECTOR
966 def_bool y
967 depends on X86_MCE_INTEL
968
969 config VM86
970 bool "Enable VM86 support" if EXPERT
971 default y
972 depends on X86_32
973 ---help---
974 This option is required by programs like DOSEMU to run 16-bit legacy
975 code on X86 processors. It also may be needed by software like
976 XFree86 to initialize some video cards via BIOS. Disabling this
977 option saves about 6k.
978
979 config TOSHIBA
980 tristate "Toshiba Laptop support"
981 depends on X86_32
982 ---help---
983 This adds a driver to safely access the System Management Mode of
984 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
985 not work on models with a Phoenix BIOS. The System Management Mode
986 is used to set the BIOS and power saving options on Toshiba portables.
987
988 For information on utilities to make use of this driver see the
989 Toshiba Linux utilities web site at:
990 <http://www.buzzard.org.uk/toshiba/>.
991
992 Say Y if you intend to run this kernel on a Toshiba portable.
993 Say N otherwise.
994
995 config I8K
996 tristate "Dell laptop support"
997 select HWMON
998 ---help---
999 This adds a driver to safely access the System Management Mode
1000 of the CPU on the Dell Inspiron 8000. The System Management Mode
1001 is used to read cpu temperature and cooling fan status and to
1002 control the fans on the I8K portables.
1003
1004 This driver has been tested only on the Inspiron 8000 but it may
1005 also work with other Dell laptops. You can force loading on other
1006 models by passing the parameter `force=1' to the module. Use at
1007 your own risk.
1008
1009 For information on utilities to make use of this driver see the
1010 I8K Linux utilities web site at:
1011 <http://people.debian.org/~dz/i8k/>
1012
1013 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1014 Say N otherwise.
1015
1016 config X86_REBOOTFIXUPS
1017 bool "Enable X86 board specific fixups for reboot"
1018 depends on X86_32
1019 ---help---
1020 This enables chipset and/or board specific fixups to be done
1021 in order to get reboot to work correctly. This is only needed on
1022 some combinations of hardware and BIOS. The symptom, for which
1023 this config is intended, is when reboot ends with a stalled/hung
1024 system.
1025
1026 Currently, the only fixup is for the Geode machines using
1027 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1028
1029 Say Y if you want to enable the fixup. Currently, it's safe to
1030 enable this option even if you don't need it.
1031 Say N otherwise.
1032
1033 config MICROCODE
1034 tristate "CPU microcode loading support"
1035 select FW_LOADER
1036 ---help---
1037
1038 If you say Y here, you will be able to update the microcode on
1039 certain Intel and AMD processors. The Intel support is for the
1040 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1041 Xeon etc. The AMD support is for families 0x10 and later. You will
1042 obviously need the actual microcode binary data itself which is not
1043 shipped with the Linux kernel.
1044
1045 This option selects the general module only, you need to select
1046 at least one vendor specific module as well.
1047
1048 To compile this driver as a module, choose M here: the module
1049 will be called microcode.
1050
1051 config MICROCODE_INTEL
1052 bool "Intel microcode loading support"
1053 depends on MICROCODE
1054 default MICROCODE
1055 select FW_LOADER
1056 ---help---
1057 This options enables microcode patch loading support for Intel
1058 processors.
1059
1060 For latest news and information on obtaining all the required
1061 Intel ingredients for this driver, check:
1062 <http://www.urbanmyth.org/microcode/>.
1063
1064 config MICROCODE_AMD
1065 bool "AMD microcode loading support"
1066 depends on MICROCODE
1067 select FW_LOADER
1068 ---help---
1069 If you select this option, microcode patch loading support for AMD
1070 processors will be enabled.
1071
1072 config MICROCODE_OLD_INTERFACE
1073 def_bool y
1074 depends on MICROCODE
1075
1076 config MICROCODE_INTEL_LIB
1077 def_bool y
1078 depends on MICROCODE_INTEL
1079
1080 config MICROCODE_INTEL_EARLY
1081 def_bool n
1082
1083 config MICROCODE_AMD_EARLY
1084 def_bool n
1085
1086 config MICROCODE_EARLY
1087 bool "Early load microcode"
1088 depends on MICROCODE=y && BLK_DEV_INITRD
1089 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1090 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1091 default y
1092 help
1093 This option provides functionality to read additional microcode data
1094 at the beginning of initrd image. The data tells kernel to load
1095 microcode to CPU's as early as possible. No functional change if no
1096 microcode data is glued to the initrd, therefore it's safe to say Y.
1097
1098 config X86_MSR
1099 tristate "/dev/cpu/*/msr - Model-specific register support"
1100 ---help---
1101 This device gives privileged processes access to the x86
1102 Model-Specific Registers (MSRs). It is a character device with
1103 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1104 MSR accesses are directed to a specific CPU on multi-processor
1105 systems.
1106
1107 config X86_CPUID
1108 tristate "/dev/cpu/*/cpuid - CPU information support"
1109 ---help---
1110 This device gives processes access to the x86 CPUID instruction to
1111 be executed on a specific processor. It is a character device
1112 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1113 /dev/cpu/31/cpuid.
1114
1115 choice
1116 prompt "High Memory Support"
1117 default HIGHMEM64G if X86_NUMAQ
1118 default HIGHMEM4G
1119 depends on X86_32
1120
1121 config NOHIGHMEM
1122 bool "off"
1123 depends on !X86_NUMAQ
1124 ---help---
1125 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1126 However, the address space of 32-bit x86 processors is only 4
1127 Gigabytes large. That means that, if you have a large amount of
1128 physical memory, not all of it can be "permanently mapped" by the
1129 kernel. The physical memory that's not permanently mapped is called
1130 "high memory".
1131
1132 If you are compiling a kernel which will never run on a machine with
1133 more than 1 Gigabyte total physical RAM, answer "off" here (default
1134 choice and suitable for most users). This will result in a "3GB/1GB"
1135 split: 3GB are mapped so that each process sees a 3GB virtual memory
1136 space and the remaining part of the 4GB virtual memory space is used
1137 by the kernel to permanently map as much physical memory as
1138 possible.
1139
1140 If the machine has between 1 and 4 Gigabytes physical RAM, then
1141 answer "4GB" here.
1142
1143 If more than 4 Gigabytes is used then answer "64GB" here. This
1144 selection turns Intel PAE (Physical Address Extension) mode on.
1145 PAE implements 3-level paging on IA32 processors. PAE is fully
1146 supported by Linux, PAE mode is implemented on all recent Intel
1147 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1148 then the kernel will not boot on CPUs that don't support PAE!
1149
1150 The actual amount of total physical memory will either be
1151 auto detected or can be forced by using a kernel command line option
1152 such as "mem=256M". (Try "man bootparam" or see the documentation of
1153 your boot loader (lilo or loadlin) about how to pass options to the
1154 kernel at boot time.)
1155
1156 If unsure, say "off".
1157
1158 config HIGHMEM4G
1159 bool "4GB"
1160 depends on !X86_NUMAQ
1161 ---help---
1162 Select this if you have a 32-bit processor and between 1 and 4
1163 gigabytes of physical RAM.
1164
1165 config HIGHMEM64G
1166 bool "64GB"
1167 depends on !M486
1168 select X86_PAE
1169 ---help---
1170 Select this if you have a 32-bit processor and more than 4
1171 gigabytes of physical RAM.
1172
1173 endchoice
1174
1175 choice
1176 prompt "Memory split" if EXPERT
1177 default VMSPLIT_3G
1178 depends on X86_32
1179 ---help---
1180 Select the desired split between kernel and user memory.
1181
1182 If the address range available to the kernel is less than the
1183 physical memory installed, the remaining memory will be available
1184 as "high memory". Accessing high memory is a little more costly
1185 than low memory, as it needs to be mapped into the kernel first.
1186 Note that increasing the kernel address space limits the range
1187 available to user programs, making the address space there
1188 tighter. Selecting anything other than the default 3G/1G split
1189 will also likely make your kernel incompatible with binary-only
1190 kernel modules.
1191
1192 If you are not absolutely sure what you are doing, leave this
1193 option alone!
1194
1195 config VMSPLIT_3G
1196 bool "3G/1G user/kernel split"
1197 config VMSPLIT_3G_OPT
1198 depends on !X86_PAE
1199 bool "3G/1G user/kernel split (for full 1G low memory)"
1200 config VMSPLIT_2G
1201 bool "2G/2G user/kernel split"
1202 config VMSPLIT_2G_OPT
1203 depends on !X86_PAE
1204 bool "2G/2G user/kernel split (for full 2G low memory)"
1205 config VMSPLIT_1G
1206 bool "1G/3G user/kernel split"
1207 endchoice
1208
1209 config PAGE_OFFSET
1210 hex
1211 default 0xB0000000 if VMSPLIT_3G_OPT
1212 default 0x80000000 if VMSPLIT_2G
1213 default 0x78000000 if VMSPLIT_2G_OPT
1214 default 0x40000000 if VMSPLIT_1G
1215 default 0xC0000000
1216 depends on X86_32
1217
1218 config HIGHMEM
1219 def_bool y
1220 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1221
1222 config X86_PAE
1223 bool "PAE (Physical Address Extension) Support"
1224 depends on X86_32 && !HIGHMEM4G
1225 ---help---
1226 PAE is required for NX support, and furthermore enables
1227 larger swapspace support for non-overcommit purposes. It
1228 has the cost of more pagetable lookup overhead, and also
1229 consumes more pagetable space per process.
1230
1231 config ARCH_PHYS_ADDR_T_64BIT
1232 def_bool y
1233 depends on X86_64 || X86_PAE
1234
1235 config ARCH_DMA_ADDR_T_64BIT
1236 def_bool y
1237 depends on X86_64 || HIGHMEM64G
1238
1239 config DIRECT_GBPAGES
1240 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1241 default y
1242 depends on X86_64
1243 ---help---
1244 Allow the kernel linear mapping to use 1GB pages on CPUs that
1245 support it. This can improve the kernel's performance a tiny bit by
1246 reducing TLB pressure. If in doubt, say "Y".
1247
1248 # Common NUMA Features
1249 config NUMA
1250 bool "Numa Memory Allocation and Scheduler Support"
1251 depends on SMP
1252 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1253 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1254 ---help---
1255 Enable NUMA (Non Uniform Memory Access) support.
1256
1257 The kernel will try to allocate memory used by a CPU on the
1258 local memory controller of the CPU and add some more
1259 NUMA awareness to the kernel.
1260
1261 For 64-bit this is recommended if the system is Intel Core i7
1262 (or later), AMD Opteron, or EM64T NUMA.
1263
1264 For 32-bit this is only needed on (rare) 32-bit-only platforms
1265 that support NUMA topologies, such as NUMAQ / Summit, or if you
1266 boot a 32-bit kernel on a 64-bit NUMA platform.
1267
1268 Otherwise, you should say N.
1269
1270 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1271 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1272
1273 config AMD_NUMA
1274 def_bool y
1275 prompt "Old style AMD Opteron NUMA detection"
1276 depends on X86_64 && NUMA && PCI
1277 ---help---
1278 Enable AMD NUMA node topology detection. You should say Y here if
1279 you have a multi processor AMD system. This uses an old method to
1280 read the NUMA configuration directly from the builtin Northbridge
1281 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1282 which also takes priority if both are compiled in.
1283
1284 config X86_64_ACPI_NUMA
1285 def_bool y
1286 prompt "ACPI NUMA detection"
1287 depends on X86_64 && NUMA && ACPI && PCI
1288 select ACPI_NUMA
1289 ---help---
1290 Enable ACPI SRAT based node topology detection.
1291
1292 # Some NUMA nodes have memory ranges that span
1293 # other nodes. Even though a pfn is valid and
1294 # between a node's start and end pfns, it may not
1295 # reside on that node. See memmap_init_zone()
1296 # for details.
1297 config NODES_SPAN_OTHER_NODES
1298 def_bool y
1299 depends on X86_64_ACPI_NUMA
1300
1301 config NUMA_EMU
1302 bool "NUMA emulation"
1303 depends on NUMA
1304 ---help---
1305 Enable NUMA emulation. A flat machine will be split
1306 into virtual nodes when booted with "numa=fake=N", where N is the
1307 number of nodes. This is only useful for debugging.
1308
1309 config NODES_SHIFT
1310 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1311 range 1 10
1312 default "10" if MAXSMP
1313 default "6" if X86_64
1314 default "4" if X86_NUMAQ
1315 default "3"
1316 depends on NEED_MULTIPLE_NODES
1317 ---help---
1318 Specify the maximum number of NUMA Nodes available on the target
1319 system. Increases memory reserved to accommodate various tables.
1320
1321 config ARCH_HAVE_MEMORY_PRESENT
1322 def_bool y
1323 depends on X86_32 && DISCONTIGMEM
1324
1325 config NEED_NODE_MEMMAP_SIZE
1326 def_bool y
1327 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1328
1329 config ARCH_FLATMEM_ENABLE
1330 def_bool y
1331 depends on X86_32 && !NUMA
1332
1333 config ARCH_DISCONTIGMEM_ENABLE
1334 def_bool y
1335 depends on NUMA && X86_32
1336
1337 config ARCH_DISCONTIGMEM_DEFAULT
1338 def_bool y
1339 depends on NUMA && X86_32
1340
1341 config ARCH_SPARSEMEM_ENABLE
1342 def_bool y
1343 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1344 select SPARSEMEM_STATIC if X86_32
1345 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1346
1347 config ARCH_SPARSEMEM_DEFAULT
1348 def_bool y
1349 depends on X86_64
1350
1351 config ARCH_SELECT_MEMORY_MODEL
1352 def_bool y
1353 depends on ARCH_SPARSEMEM_ENABLE
1354
1355 config ARCH_MEMORY_PROBE
1356 bool "Enable sysfs memory/probe interface"
1357 depends on X86_64 && MEMORY_HOTPLUG
1358 help
1359 This option enables a sysfs memory/probe interface for testing.
1360 See Documentation/memory-hotplug.txt for more information.
1361 If you are unsure how to answer this question, answer N.
1362
1363 config ARCH_PROC_KCORE_TEXT
1364 def_bool y
1365 depends on X86_64 && PROC_KCORE
1366
1367 config ILLEGAL_POINTER_VALUE
1368 hex
1369 default 0 if X86_32
1370 default 0xdead000000000000 if X86_64
1371
1372 source "mm/Kconfig"
1373
1374 config HIGHPTE
1375 bool "Allocate 3rd-level pagetables from highmem"
1376 depends on HIGHMEM
1377 ---help---
1378 The VM uses one page table entry for each page of physical memory.
1379 For systems with a lot of RAM, this can be wasteful of precious
1380 low memory. Setting this option will put user-space page table
1381 entries in high memory.
1382
1383 config X86_CHECK_BIOS_CORRUPTION
1384 bool "Check for low memory corruption"
1385 ---help---
1386 Periodically check for memory corruption in low memory, which
1387 is suspected to be caused by BIOS. Even when enabled in the
1388 configuration, it is disabled at runtime. Enable it by
1389 setting "memory_corruption_check=1" on the kernel command
1390 line. By default it scans the low 64k of memory every 60
1391 seconds; see the memory_corruption_check_size and
1392 memory_corruption_check_period parameters in
1393 Documentation/kernel-parameters.txt to adjust this.
1394
1395 When enabled with the default parameters, this option has
1396 almost no overhead, as it reserves a relatively small amount
1397 of memory and scans it infrequently. It both detects corruption
1398 and prevents it from affecting the running system.
1399
1400 It is, however, intended as a diagnostic tool; if repeatable
1401 BIOS-originated corruption always affects the same memory,
1402 you can use memmap= to prevent the kernel from using that
1403 memory.
1404
1405 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1406 bool "Set the default setting of memory_corruption_check"
1407 depends on X86_CHECK_BIOS_CORRUPTION
1408 default y
1409 ---help---
1410 Set whether the default state of memory_corruption_check is
1411 on or off.
1412
1413 config X86_RESERVE_LOW
1414 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1415 default 64
1416 range 4 640
1417 ---help---
1418 Specify the amount of low memory to reserve for the BIOS.
1419
1420 The first page contains BIOS data structures that the kernel
1421 must not use, so that page must always be reserved.
1422
1423 By default we reserve the first 64K of physical RAM, as a
1424 number of BIOSes are known to corrupt that memory range
1425 during events such as suspend/resume or monitor cable
1426 insertion, so it must not be used by the kernel.
1427
1428 You can set this to 4 if you are absolutely sure that you
1429 trust the BIOS to get all its memory reservations and usages
1430 right. If you know your BIOS have problems beyond the
1431 default 64K area, you can set this to 640 to avoid using the
1432 entire low memory range.
1433
1434 If you have doubts about the BIOS (e.g. suspend/resume does
1435 not work or there's kernel crashes after certain hardware
1436 hotplug events) then you might want to enable
1437 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1438 typical corruption patterns.
1439
1440 Leave this to the default value of 64 if you are unsure.
1441
1442 config MATH_EMULATION
1443 bool
1444 prompt "Math emulation" if X86_32
1445 ---help---
1446 Linux can emulate a math coprocessor (used for floating point
1447 operations) if you don't have one. 486DX and Pentium processors have
1448 a math coprocessor built in, 486SX and 386 do not, unless you added
1449 a 487DX or 387, respectively. (The messages during boot time can
1450 give you some hints here ["man dmesg"].) Everyone needs either a
1451 coprocessor or this emulation.
1452
1453 If you don't have a math coprocessor, you need to say Y here; if you
1454 say Y here even though you have a coprocessor, the coprocessor will
1455 be used nevertheless. (This behavior can be changed with the kernel
1456 command line option "no387", which comes handy if your coprocessor
1457 is broken. Try "man bootparam" or see the documentation of your boot
1458 loader (lilo or loadlin) about how to pass options to the kernel at
1459 boot time.) This means that it is a good idea to say Y here if you
1460 intend to use this kernel on different machines.
1461
1462 More information about the internals of the Linux math coprocessor
1463 emulation can be found in <file:arch/x86/math-emu/README>.
1464
1465 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1466 kernel, it won't hurt.
1467
1468 config MTRR
1469 def_bool y
1470 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1471 ---help---
1472 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1473 the Memory Type Range Registers (MTRRs) may be used to control
1474 processor access to memory ranges. This is most useful if you have
1475 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1476 allows bus write transfers to be combined into a larger transfer
1477 before bursting over the PCI/AGP bus. This can increase performance
1478 of image write operations 2.5 times or more. Saying Y here creates a
1479 /proc/mtrr file which may be used to manipulate your processor's
1480 MTRRs. Typically the X server should use this.
1481
1482 This code has a reasonably generic interface so that similar
1483 control registers on other processors can be easily supported
1484 as well:
1485
1486 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1487 Registers (ARRs) which provide a similar functionality to MTRRs. For
1488 these, the ARRs are used to emulate the MTRRs.
1489 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1490 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1491 write-combining. All of these processors are supported by this code
1492 and it makes sense to say Y here if you have one of them.
1493
1494 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1495 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1496 can lead to all sorts of problems, so it's good to say Y here.
1497
1498 You can safely say Y even if your machine doesn't have MTRRs, you'll
1499 just add about 9 KB to your kernel.
1500
1501 See <file:Documentation/x86/mtrr.txt> for more information.
1502
1503 config MTRR_SANITIZER
1504 def_bool y
1505 prompt "MTRR cleanup support"
1506 depends on MTRR
1507 ---help---
1508 Convert MTRR layout from continuous to discrete, so X drivers can
1509 add writeback entries.
1510
1511 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1512 The largest mtrr entry size for a continuous block can be set with
1513 mtrr_chunk_size.
1514
1515 If unsure, say Y.
1516
1517 config MTRR_SANITIZER_ENABLE_DEFAULT
1518 int "MTRR cleanup enable value (0-1)"
1519 range 0 1
1520 default "0"
1521 depends on MTRR_SANITIZER
1522 ---help---
1523 Enable mtrr cleanup default value
1524
1525 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1526 int "MTRR cleanup spare reg num (0-7)"
1527 range 0 7
1528 default "1"
1529 depends on MTRR_SANITIZER
1530 ---help---
1531 mtrr cleanup spare entries default, it can be changed via
1532 mtrr_spare_reg_nr=N on the kernel command line.
1533
1534 config X86_PAT
1535 def_bool y
1536 prompt "x86 PAT support" if EXPERT
1537 depends on MTRR
1538 ---help---
1539 Use PAT attributes to setup page level cache control.
1540
1541 PATs are the modern equivalents of MTRRs and are much more
1542 flexible than MTRRs.
1543
1544 Say N here if you see bootup problems (boot crash, boot hang,
1545 spontaneous reboots) or a non-working video driver.
1546
1547 If unsure, say Y.
1548
1549 config ARCH_USES_PG_UNCACHED
1550 def_bool y
1551 depends on X86_PAT
1552
1553 config ARCH_RANDOM
1554 def_bool y
1555 prompt "x86 architectural random number generator" if EXPERT
1556 ---help---
1557 Enable the x86 architectural RDRAND instruction
1558 (Intel Bull Mountain technology) to generate random numbers.
1559 If supported, this is a high bandwidth, cryptographically
1560 secure hardware random number generator.
1561
1562 config X86_SMAP
1563 def_bool y
1564 prompt "Supervisor Mode Access Prevention" if EXPERT
1565 ---help---
1566 Supervisor Mode Access Prevention (SMAP) is a security
1567 feature in newer Intel processors. There is a small
1568 performance cost if this enabled and turned on; there is
1569 also a small increase in the kernel size if this is enabled.
1570
1571 If unsure, say Y.
1572
1573 config EFI
1574 bool "EFI runtime service support"
1575 depends on ACPI
1576 select UCS2_STRING
1577 ---help---
1578 This enables the kernel to use EFI runtime services that are
1579 available (such as the EFI variable services).
1580
1581 This option is only useful on systems that have EFI firmware.
1582 In addition, you should use the latest ELILO loader available
1583 at <http://elilo.sourceforge.net> in order to take advantage
1584 of EFI runtime services. However, even with this option, the
1585 resultant kernel should continue to boot on existing non-EFI
1586 platforms.
1587
1588 config EFI_STUB
1589 bool "EFI stub support"
1590 depends on EFI
1591 ---help---
1592 This kernel feature allows a bzImage to be loaded directly
1593 by EFI firmware without the use of a bootloader.
1594
1595 See Documentation/x86/efi-stub.txt for more information.
1596
1597 config SECCOMP
1598 def_bool y
1599 prompt "Enable seccomp to safely compute untrusted bytecode"
1600 ---help---
1601 This kernel feature is useful for number crunching applications
1602 that may need to compute untrusted bytecode during their
1603 execution. By using pipes or other transports made available to
1604 the process as file descriptors supporting the read/write
1605 syscalls, it's possible to isolate those applications in
1606 their own address space using seccomp. Once seccomp is
1607 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1608 and the task is only allowed to execute a few safe syscalls
1609 defined by each seccomp mode.
1610
1611 If unsure, say Y. Only embedded should say N here.
1612
1613 config CC_STACKPROTECTOR
1614 bool "Enable -fstack-protector buffer overflow detection"
1615 ---help---
1616 This option turns on the -fstack-protector GCC feature. This
1617 feature puts, at the beginning of functions, a canary value on
1618 the stack just before the return address, and validates
1619 the value just before actually returning. Stack based buffer
1620 overflows (that need to overwrite this return address) now also
1621 overwrite the canary, which gets detected and the attack is then
1622 neutralized via a kernel panic.
1623
1624 This feature requires gcc version 4.2 or above, or a distribution
1625 gcc with the feature backported. Older versions are automatically
1626 detected and for those versions, this configuration option is
1627 ignored. (and a warning is printed during bootup)
1628
1629 source kernel/Kconfig.hz
1630
1631 config KEXEC
1632 bool "kexec system call"
1633 ---help---
1634 kexec is a system call that implements the ability to shutdown your
1635 current kernel, and to start another kernel. It is like a reboot
1636 but it is independent of the system firmware. And like a reboot
1637 you can start any kernel with it, not just Linux.
1638
1639 The name comes from the similarity to the exec system call.
1640
1641 It is an ongoing process to be certain the hardware in a machine
1642 is properly shutdown, so do not be surprised if this code does not
1643 initially work for you. As of this writing the exact hardware
1644 interface is strongly in flux, so no good recommendation can be
1645 made.
1646
1647 config CRASH_DUMP
1648 bool "kernel crash dumps"
1649 depends on X86_64 || (X86_32 && HIGHMEM)
1650 ---help---
1651 Generate crash dump after being started by kexec.
1652 This should be normally only set in special crash dump kernels
1653 which are loaded in the main kernel with kexec-tools into
1654 a specially reserved region and then later executed after
1655 a crash by kdump/kexec. The crash dump kernel must be compiled
1656 to a memory address not used by the main kernel or BIOS using
1657 PHYSICAL_START, or it must be built as a relocatable image
1658 (CONFIG_RELOCATABLE=y).
1659 For more details see Documentation/kdump/kdump.txt
1660
1661 config KEXEC_JUMP
1662 bool "kexec jump"
1663 depends on KEXEC && HIBERNATION
1664 ---help---
1665 Jump between original kernel and kexeced kernel and invoke
1666 code in physical address mode via KEXEC
1667
1668 config PHYSICAL_START
1669 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1670 default "0x1000000"
1671 ---help---
1672 This gives the physical address where the kernel is loaded.
1673
1674 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1675 bzImage will decompress itself to above physical address and
1676 run from there. Otherwise, bzImage will run from the address where
1677 it has been loaded by the boot loader and will ignore above physical
1678 address.
1679
1680 In normal kdump cases one does not have to set/change this option
1681 as now bzImage can be compiled as a completely relocatable image
1682 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1683 address. This option is mainly useful for the folks who don't want
1684 to use a bzImage for capturing the crash dump and want to use a
1685 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1686 to be specifically compiled to run from a specific memory area
1687 (normally a reserved region) and this option comes handy.
1688
1689 So if you are using bzImage for capturing the crash dump,
1690 leave the value here unchanged to 0x1000000 and set
1691 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1692 for capturing the crash dump change this value to start of
1693 the reserved region. In other words, it can be set based on
1694 the "X" value as specified in the "crashkernel=YM@XM"
1695 command line boot parameter passed to the panic-ed
1696 kernel. Please take a look at Documentation/kdump/kdump.txt
1697 for more details about crash dumps.
1698
1699 Usage of bzImage for capturing the crash dump is recommended as
1700 one does not have to build two kernels. Same kernel can be used
1701 as production kernel and capture kernel. Above option should have
1702 gone away after relocatable bzImage support is introduced. But it
1703 is present because there are users out there who continue to use
1704 vmlinux for dump capture. This option should go away down the
1705 line.
1706
1707 Don't change this unless you know what you are doing.
1708
1709 config RELOCATABLE
1710 bool "Build a relocatable kernel"
1711 default y
1712 ---help---
1713 This builds a kernel image that retains relocation information
1714 so it can be loaded someplace besides the default 1MB.
1715 The relocations tend to make the kernel binary about 10% larger,
1716 but are discarded at runtime.
1717
1718 One use is for the kexec on panic case where the recovery kernel
1719 must live at a different physical address than the primary
1720 kernel.
1721
1722 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1723 it has been loaded at and the compile time physical address
1724 (CONFIG_PHYSICAL_START) is ignored.
1725
1726 # Relocation on x86-32 needs some additional build support
1727 config X86_NEED_RELOCS
1728 def_bool y
1729 depends on X86_32 && RELOCATABLE
1730
1731 config PHYSICAL_ALIGN
1732 hex "Alignment value to which kernel should be aligned"
1733 default "0x1000000"
1734 range 0x2000 0x1000000 if X86_32
1735 range 0x200000 0x1000000 if X86_64
1736 ---help---
1737 This value puts the alignment restrictions on physical address
1738 where kernel is loaded and run from. Kernel is compiled for an
1739 address which meets above alignment restriction.
1740
1741 If bootloader loads the kernel at a non-aligned address and
1742 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1743 address aligned to above value and run from there.
1744
1745 If bootloader loads the kernel at a non-aligned address and
1746 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1747 load address and decompress itself to the address it has been
1748 compiled for and run from there. The address for which kernel is
1749 compiled already meets above alignment restrictions. Hence the
1750 end result is that kernel runs from a physical address meeting
1751 above alignment restrictions.
1752
1753 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1754 this value must be a multiple of 0x200000.
1755
1756 Don't change this unless you know what you are doing.
1757
1758 config HOTPLUG_CPU
1759 bool "Support for hot-pluggable CPUs"
1760 depends on SMP
1761 ---help---
1762 Say Y here to allow turning CPUs off and on. CPUs can be
1763 controlled through /sys/devices/system/cpu.
1764 ( Note: power management support will enable this option
1765 automatically on SMP systems. )
1766 Say N if you want to disable CPU hotplug.
1767
1768 config BOOTPARAM_HOTPLUG_CPU0
1769 bool "Set default setting of cpu0_hotpluggable"
1770 default n
1771 depends on HOTPLUG_CPU
1772 ---help---
1773 Set whether default state of cpu0_hotpluggable is on or off.
1774
1775 Say Y here to enable CPU0 hotplug by default. If this switch
1776 is turned on, there is no need to give cpu0_hotplug kernel
1777 parameter and the CPU0 hotplug feature is enabled by default.
1778
1779 Please note: there are two known CPU0 dependencies if you want
1780 to enable the CPU0 hotplug feature either by this switch or by
1781 cpu0_hotplug kernel parameter.
1782
1783 First, resume from hibernate or suspend always starts from CPU0.
1784 So hibernate and suspend are prevented if CPU0 is offline.
1785
1786 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1787 offline if any interrupt can not migrate out of CPU0. There may
1788 be other CPU0 dependencies.
1789
1790 Please make sure the dependencies are under your control before
1791 you enable this feature.
1792
1793 Say N if you don't want to enable CPU0 hotplug feature by default.
1794 You still can enable the CPU0 hotplug feature at boot by kernel
1795 parameter cpu0_hotplug.
1796
1797 config DEBUG_HOTPLUG_CPU0
1798 def_bool n
1799 prompt "Debug CPU0 hotplug"
1800 depends on HOTPLUG_CPU
1801 ---help---
1802 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1803 soon as possible and boots up userspace with CPU0 offlined. User
1804 can online CPU0 back after boot time.
1805
1806 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1807 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1808 compilation or giving cpu0_hotplug kernel parameter at boot.
1809
1810 If unsure, say N.
1811
1812 config COMPAT_VDSO
1813 def_bool y
1814 prompt "Compat VDSO support"
1815 depends on X86_32 || IA32_EMULATION
1816 ---help---
1817 Map the 32-bit VDSO to the predictable old-style address too.
1818
1819 Say N here if you are running a sufficiently recent glibc
1820 version (2.3.3 or later), to remove the high-mapped
1821 VDSO mapping and to exclusively use the randomized VDSO.
1822
1823 If unsure, say Y.
1824
1825 config CMDLINE_BOOL
1826 bool "Built-in kernel command line"
1827 ---help---
1828 Allow for specifying boot arguments to the kernel at
1829 build time. On some systems (e.g. embedded ones), it is
1830 necessary or convenient to provide some or all of the
1831 kernel boot arguments with the kernel itself (that is,
1832 to not rely on the boot loader to provide them.)
1833
1834 To compile command line arguments into the kernel,
1835 set this option to 'Y', then fill in the
1836 the boot arguments in CONFIG_CMDLINE.
1837
1838 Systems with fully functional boot loaders (i.e. non-embedded)
1839 should leave this option set to 'N'.
1840
1841 config CMDLINE
1842 string "Built-in kernel command string"
1843 depends on CMDLINE_BOOL
1844 default ""
1845 ---help---
1846 Enter arguments here that should be compiled into the kernel
1847 image and used at boot time. If the boot loader provides a
1848 command line at boot time, it is appended to this string to
1849 form the full kernel command line, when the system boots.
1850
1851 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1852 change this behavior.
1853
1854 In most cases, the command line (whether built-in or provided
1855 by the boot loader) should specify the device for the root
1856 file system.
1857
1858 config CMDLINE_OVERRIDE
1859 bool "Built-in command line overrides boot loader arguments"
1860 depends on CMDLINE_BOOL
1861 ---help---
1862 Set this option to 'Y' to have the kernel ignore the boot loader
1863 command line, and use ONLY the built-in command line.
1864
1865 This is used to work around broken boot loaders. This should
1866 be set to 'N' under normal conditions.
1867
1868 endmenu
1869
1870 config ARCH_ENABLE_MEMORY_HOTPLUG
1871 def_bool y
1872 depends on X86_64 || (X86_32 && HIGHMEM)
1873
1874 config ARCH_ENABLE_MEMORY_HOTREMOVE
1875 def_bool y
1876 depends on MEMORY_HOTPLUG
1877
1878 config USE_PERCPU_NUMA_NODE_ID
1879 def_bool y
1880 depends on NUMA
1881
1882 menu "Power management and ACPI options"
1883
1884 config ARCH_HIBERNATION_HEADER
1885 def_bool y
1886 depends on X86_64 && HIBERNATION
1887
1888 source "kernel/power/Kconfig"
1889
1890 source "drivers/acpi/Kconfig"
1891
1892 source "drivers/sfi/Kconfig"
1893
1894 config X86_APM_BOOT
1895 def_bool y
1896 depends on APM
1897
1898 menuconfig APM
1899 tristate "APM (Advanced Power Management) BIOS support"
1900 depends on X86_32 && PM_SLEEP
1901 ---help---
1902 APM is a BIOS specification for saving power using several different
1903 techniques. This is mostly useful for battery powered laptops with
1904 APM compliant BIOSes. If you say Y here, the system time will be
1905 reset after a RESUME operation, the /proc/apm device will provide
1906 battery status information, and user-space programs will receive
1907 notification of APM "events" (e.g. battery status change).
1908
1909 If you select "Y" here, you can disable actual use of the APM
1910 BIOS by passing the "apm=off" option to the kernel at boot time.
1911
1912 Note that the APM support is almost completely disabled for
1913 machines with more than one CPU.
1914
1915 In order to use APM, you will need supporting software. For location
1916 and more information, read <file:Documentation/power/apm-acpi.txt>
1917 and the Battery Powered Linux mini-HOWTO, available from
1918 <http://www.tldp.org/docs.html#howto>.
1919
1920 This driver does not spin down disk drives (see the hdparm(8)
1921 manpage ("man 8 hdparm") for that), and it doesn't turn off
1922 VESA-compliant "green" monitors.
1923
1924 This driver does not support the TI 4000M TravelMate and the ACER
1925 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1926 desktop machines also don't have compliant BIOSes, and this driver
1927 may cause those machines to panic during the boot phase.
1928
1929 Generally, if you don't have a battery in your machine, there isn't
1930 much point in using this driver and you should say N. If you get
1931 random kernel OOPSes or reboots that don't seem to be related to
1932 anything, try disabling/enabling this option (or disabling/enabling
1933 APM in your BIOS).
1934
1935 Some other things you should try when experiencing seemingly random,
1936 "weird" problems:
1937
1938 1) make sure that you have enough swap space and that it is
1939 enabled.
1940 2) pass the "no-hlt" option to the kernel
1941 3) switch on floating point emulation in the kernel and pass
1942 the "no387" option to the kernel
1943 4) pass the "floppy=nodma" option to the kernel
1944 5) pass the "mem=4M" option to the kernel (thereby disabling
1945 all but the first 4 MB of RAM)
1946 6) make sure that the CPU is not over clocked.
1947 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1948 8) disable the cache from your BIOS settings
1949 9) install a fan for the video card or exchange video RAM
1950 10) install a better fan for the CPU
1951 11) exchange RAM chips
1952 12) exchange the motherboard.
1953
1954 To compile this driver as a module, choose M here: the
1955 module will be called apm.
1956
1957 if APM
1958
1959 config APM_IGNORE_USER_SUSPEND
1960 bool "Ignore USER SUSPEND"
1961 ---help---
1962 This option will ignore USER SUSPEND requests. On machines with a
1963 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1964 series notebooks, it is necessary to say Y because of a BIOS bug.
1965
1966 config APM_DO_ENABLE
1967 bool "Enable PM at boot time"
1968 ---help---
1969 Enable APM features at boot time. From page 36 of the APM BIOS
1970 specification: "When disabled, the APM BIOS does not automatically
1971 power manage devices, enter the Standby State, enter the Suspend
1972 State, or take power saving steps in response to CPU Idle calls."
1973 This driver will make CPU Idle calls when Linux is idle (unless this
1974 feature is turned off -- see "Do CPU IDLE calls", below). This
1975 should always save battery power, but more complicated APM features
1976 will be dependent on your BIOS implementation. You may need to turn
1977 this option off if your computer hangs at boot time when using APM
1978 support, or if it beeps continuously instead of suspending. Turn
1979 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1980 T400CDT. This is off by default since most machines do fine without
1981 this feature.
1982
1983 config APM_CPU_IDLE
1984 depends on CPU_IDLE
1985 bool "Make CPU Idle calls when idle"
1986 ---help---
1987 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1988 On some machines, this can activate improved power savings, such as
1989 a slowed CPU clock rate, when the machine is idle. These idle calls
1990 are made after the idle loop has run for some length of time (e.g.,
1991 333 mS). On some machines, this will cause a hang at boot time or
1992 whenever the CPU becomes idle. (On machines with more than one CPU,
1993 this option does nothing.)
1994
1995 config APM_DISPLAY_BLANK
1996 bool "Enable console blanking using APM"
1997 ---help---
1998 Enable console blanking using the APM. Some laptops can use this to
1999 turn off the LCD backlight when the screen blanker of the Linux
2000 virtual console blanks the screen. Note that this is only used by
2001 the virtual console screen blanker, and won't turn off the backlight
2002 when using the X Window system. This also doesn't have anything to
2003 do with your VESA-compliant power-saving monitor. Further, this
2004 option doesn't work for all laptops -- it might not turn off your
2005 backlight at all, or it might print a lot of errors to the console,
2006 especially if you are using gpm.
2007
2008 config APM_ALLOW_INTS
2009 bool "Allow interrupts during APM BIOS calls"
2010 ---help---
2011 Normally we disable external interrupts while we are making calls to
2012 the APM BIOS as a measure to lessen the effects of a badly behaving
2013 BIOS implementation. The BIOS should reenable interrupts if it
2014 needs to. Unfortunately, some BIOSes do not -- especially those in
2015 many of the newer IBM Thinkpads. If you experience hangs when you
2016 suspend, try setting this to Y. Otherwise, say N.
2017
2018 endif # APM
2019
2020 source "drivers/cpufreq/Kconfig"
2021
2022 source "drivers/cpuidle/Kconfig"
2023
2024 source "drivers/idle/Kconfig"
2025
2026 endmenu
2027
2028
2029 menu "Bus options (PCI etc.)"
2030
2031 config PCI
2032 bool "PCI support"
2033 default y
2034 ---help---
2035 Find out whether you have a PCI motherboard. PCI is the name of a
2036 bus system, i.e. the way the CPU talks to the other stuff inside
2037 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2038 VESA. If you have PCI, say Y, otherwise N.
2039
2040 choice
2041 prompt "PCI access mode"
2042 depends on X86_32 && PCI
2043 default PCI_GOANY
2044 ---help---
2045 On PCI systems, the BIOS can be used to detect the PCI devices and
2046 determine their configuration. However, some old PCI motherboards
2047 have BIOS bugs and may crash if this is done. Also, some embedded
2048 PCI-based systems don't have any BIOS at all. Linux can also try to
2049 detect the PCI hardware directly without using the BIOS.
2050
2051 With this option, you can specify how Linux should detect the
2052 PCI devices. If you choose "BIOS", the BIOS will be used,
2053 if you choose "Direct", the BIOS won't be used, and if you
2054 choose "MMConfig", then PCI Express MMCONFIG will be used.
2055 If you choose "Any", the kernel will try MMCONFIG, then the
2056 direct access method and falls back to the BIOS if that doesn't
2057 work. If unsure, go with the default, which is "Any".
2058
2059 config PCI_GOBIOS
2060 bool "BIOS"
2061
2062 config PCI_GOMMCONFIG
2063 bool "MMConfig"
2064
2065 config PCI_GODIRECT
2066 bool "Direct"
2067
2068 config PCI_GOOLPC
2069 bool "OLPC XO-1"
2070 depends on OLPC
2071
2072 config PCI_GOANY
2073 bool "Any"
2074
2075 endchoice
2076
2077 config PCI_BIOS
2078 def_bool y
2079 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2080
2081 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2082 config PCI_DIRECT
2083 def_bool y
2084 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2085
2086 config PCI_MMCONFIG
2087 def_bool y
2088 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2089
2090 config PCI_OLPC
2091 def_bool y
2092 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2093
2094 config PCI_XEN
2095 def_bool y
2096 depends on PCI && XEN
2097 select SWIOTLB_XEN
2098
2099 config PCI_DOMAINS
2100 def_bool y
2101 depends on PCI
2102
2103 config PCI_MMCONFIG
2104 bool "Support mmconfig PCI config space access"
2105 depends on X86_64 && PCI && ACPI
2106
2107 config PCI_CNB20LE_QUIRK
2108 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2109 depends on PCI
2110 help
2111 Read the PCI windows out of the CNB20LE host bridge. This allows
2112 PCI hotplug to work on systems with the CNB20LE chipset which do
2113 not have ACPI.
2114
2115 There's no public spec for this chipset, and this functionality
2116 is known to be incomplete.
2117
2118 You should say N unless you know you need this.
2119
2120 source "drivers/pci/pcie/Kconfig"
2121
2122 source "drivers/pci/Kconfig"
2123
2124 # x86_64 have no ISA slots, but can have ISA-style DMA.
2125 config ISA_DMA_API
2126 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2127 default y
2128 help
2129 Enables ISA-style DMA support for devices requiring such controllers.
2130 If unsure, say Y.
2131
2132 if X86_32
2133
2134 config ISA
2135 bool "ISA support"
2136 ---help---
2137 Find out whether you have ISA slots on your motherboard. ISA is the
2138 name of a bus system, i.e. the way the CPU talks to the other stuff
2139 inside your box. Other bus systems are PCI, EISA, MicroChannel
2140 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2141 newer boards don't support it. If you have ISA, say Y, otherwise N.
2142
2143 config EISA
2144 bool "EISA support"
2145 depends on ISA
2146 ---help---
2147 The Extended Industry Standard Architecture (EISA) bus was
2148 developed as an open alternative to the IBM MicroChannel bus.
2149
2150 The EISA bus provided some of the features of the IBM MicroChannel
2151 bus while maintaining backward compatibility with cards made for
2152 the older ISA bus. The EISA bus saw limited use between 1988 and
2153 1995 when it was made obsolete by the PCI bus.
2154
2155 Say Y here if you are building a kernel for an EISA-based machine.
2156
2157 Otherwise, say N.
2158
2159 source "drivers/eisa/Kconfig"
2160
2161 config SCx200
2162 tristate "NatSemi SCx200 support"
2163 ---help---
2164 This provides basic support for National Semiconductor's
2165 (now AMD's) Geode processors. The driver probes for the
2166 PCI-IDs of several on-chip devices, so its a good dependency
2167 for other scx200_* drivers.
2168
2169 If compiled as a module, the driver is named scx200.
2170
2171 config SCx200HR_TIMER
2172 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2173 depends on SCx200
2174 default y
2175 ---help---
2176 This driver provides a clocksource built upon the on-chip
2177 27MHz high-resolution timer. Its also a workaround for
2178 NSC Geode SC-1100's buggy TSC, which loses time when the
2179 processor goes idle (as is done by the scheduler). The
2180 other workaround is idle=poll boot option.
2181
2182 config OLPC
2183 bool "One Laptop Per Child support"
2184 depends on !X86_PAE
2185 select GPIOLIB
2186 select OF
2187 select OF_PROMTREE
2188 select IRQ_DOMAIN
2189 ---help---
2190 Add support for detecting the unique features of the OLPC
2191 XO hardware.
2192
2193 config OLPC_XO1_PM
2194 bool "OLPC XO-1 Power Management"
2195 depends on OLPC && MFD_CS5535 && PM_SLEEP
2196 select MFD_CORE
2197 ---help---
2198 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2199
2200 config OLPC_XO1_RTC
2201 bool "OLPC XO-1 Real Time Clock"
2202 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2203 ---help---
2204 Add support for the XO-1 real time clock, which can be used as a
2205 programmable wakeup source.
2206
2207 config OLPC_XO1_SCI
2208 bool "OLPC XO-1 SCI extras"
2209 depends on OLPC && OLPC_XO1_PM
2210 depends on INPUT=y
2211 select POWER_SUPPLY
2212 select GPIO_CS5535
2213 select MFD_CORE
2214 ---help---
2215 Add support for SCI-based features of the OLPC XO-1 laptop:
2216 - EC-driven system wakeups
2217 - Power button
2218 - Ebook switch
2219 - Lid switch
2220 - AC adapter status updates
2221 - Battery status updates
2222
2223 config OLPC_XO15_SCI
2224 bool "OLPC XO-1.5 SCI extras"
2225 depends on OLPC && ACPI
2226 select POWER_SUPPLY
2227 ---help---
2228 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2229 - EC-driven system wakeups
2230 - AC adapter status updates
2231 - Battery status updates
2232
2233 config ALIX
2234 bool "PCEngines ALIX System Support (LED setup)"
2235 select GPIOLIB
2236 ---help---
2237 This option enables system support for the PCEngines ALIX.
2238 At present this just sets up LEDs for GPIO control on
2239 ALIX2/3/6 boards. However, other system specific setup should
2240 get added here.
2241
2242 Note: You must still enable the drivers for GPIO and LED support
2243 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2244
2245 Note: You have to set alix.force=1 for boards with Award BIOS.
2246
2247 config NET5501
2248 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2249 select GPIOLIB
2250 ---help---
2251 This option enables system support for the Soekris Engineering net5501.
2252
2253 config GEOS
2254 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2255 select GPIOLIB
2256 depends on DMI
2257 ---help---
2258 This option enables system support for the Traverse Technologies GEOS.
2259
2260 config TS5500
2261 bool "Technologic Systems TS-5500 platform support"
2262 depends on MELAN
2263 select CHECK_SIGNATURE
2264 select NEW_LEDS
2265 select LEDS_CLASS
2266 ---help---
2267 This option enables system support for the Technologic Systems TS-5500.
2268
2269 endif # X86_32
2270
2271 config AMD_NB
2272 def_bool y
2273 depends on CPU_SUP_AMD && PCI
2274
2275 source "drivers/pcmcia/Kconfig"
2276
2277 source "drivers/pci/hotplug/Kconfig"
2278
2279 config RAPIDIO
2280 tristate "RapidIO support"
2281 depends on PCI
2282 default n
2283 help
2284 If enabled this option will include drivers and the core
2285 infrastructure code to support RapidIO interconnect devices.
2286
2287 source "drivers/rapidio/Kconfig"
2288
2289 config X86_SYSFB
2290 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2291 help
2292 Firmwares often provide initial graphics framebuffers so the BIOS,
2293 bootloader or kernel can show basic video-output during boot for
2294 user-guidance and debugging. Historically, x86 used the VESA BIOS
2295 Extensions and EFI-framebuffers for this, which are mostly limited
2296 to x86.
2297 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2298 framebuffers so the new generic system-framebuffer drivers can be
2299 used on x86. If the framebuffer is not compatible with the generic
2300 modes, it is adverticed as fallback platform framebuffer so legacy
2301 drivers like efifb, vesafb and uvesafb can pick it up.
2302 If this option is not selected, all system framebuffers are always
2303 marked as fallback platform framebuffers as usual.
2304
2305 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2306 not be able to pick up generic system framebuffers if this option
2307 is selected. You are highly encouraged to enable simplefb as
2308 replacement if you select this option. simplefb can correctly deal
2309 with generic system framebuffers. But you should still keep vesafb
2310 and others enabled as fallback if a system framebuffer is
2311 incompatible with simplefb.
2312
2313 If unsure, say Y.
2314
2315 endmenu
2316
2317
2318 menu "Executable file formats / Emulations"
2319
2320 source "fs/Kconfig.binfmt"
2321
2322 config IA32_EMULATION
2323 bool "IA32 Emulation"
2324 depends on X86_64
2325 select BINFMT_ELF
2326 select COMPAT_BINFMT_ELF
2327 select HAVE_UID16
2328 ---help---
2329 Include code to run legacy 32-bit programs under a
2330 64-bit kernel. You should likely turn this on, unless you're
2331 100% sure that you don't have any 32-bit programs left.
2332
2333 config IA32_AOUT
2334 tristate "IA32 a.out support"
2335 depends on IA32_EMULATION
2336 ---help---
2337 Support old a.out binaries in the 32bit emulation.
2338
2339 config X86_X32
2340 bool "x32 ABI for 64-bit mode"
2341 depends on X86_64 && IA32_EMULATION
2342 ---help---
2343 Include code to run binaries for the x32 native 32-bit ABI
2344 for 64-bit processors. An x32 process gets access to the
2345 full 64-bit register file and wide data path while leaving
2346 pointers at 32 bits for smaller memory footprint.
2347
2348 You will need a recent binutils (2.22 or later) with
2349 elf32_x86_64 support enabled to compile a kernel with this
2350 option set.
2351
2352 config COMPAT
2353 def_bool y
2354 depends on IA32_EMULATION || X86_X32
2355 select ARCH_WANT_OLD_COMPAT_IPC
2356
2357 if COMPAT
2358 config COMPAT_FOR_U64_ALIGNMENT
2359 def_bool y
2360
2361 config SYSVIPC_COMPAT
2362 def_bool y
2363 depends on SYSVIPC
2364
2365 config KEYS_COMPAT
2366 def_bool y
2367 depends on KEYS
2368 endif
2369
2370 endmenu
2371
2372
2373 config HAVE_ATOMIC_IOMAP
2374 def_bool y
2375 depends on X86_32
2376
2377 config X86_DEV_DMA_OPS
2378 bool
2379 depends on X86_64 || STA2X11
2380
2381 config X86_DMA_REMAP
2382 bool
2383 depends on STA2X11
2384
2385 source "net/Kconfig"
2386
2387 source "drivers/Kconfig"
2388
2389 source "drivers/firmware/Kconfig"
2390
2391 source "fs/Kconfig"
2392
2393 source "arch/x86/Kconfig.debug"
2394
2395 source "security/Kconfig"
2396
2397 source "crypto/Kconfig"
2398
2399 source "arch/x86/kvm/Kconfig"
2400
2401 source "lib/Kconfig"
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