Merge tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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 HAVE_GENERIC_HARDIRQS
86 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
87 select SPARSE_IRQ
88 select GENERIC_FIND_FIRST_BIT
89 select GENERIC_IRQ_PROBE
90 select GENERIC_PENDING_IRQ if SMP
91 select GENERIC_IRQ_SHOW
92 select GENERIC_CLOCKEVENTS_MIN_ADJUST
93 select IRQ_FORCED_THREADING
94 select USE_GENERIC_SMP_HELPERS if SMP
95 select HAVE_BPF_JIT if X86_64
96 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
97 select CLKEVT_I8253
98 select ARCH_HAVE_NMI_SAFE_CMPXCHG
99 select GENERIC_IOMAP
100 select DCACHE_WORD_ACCESS
101 select GENERIC_SMP_IDLE_THREAD
102 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
103 select HAVE_ARCH_SECCOMP_FILTER
104 select BUILDTIME_EXTABLE_SORT
105 select GENERIC_CMOS_UPDATE
106 select HAVE_ARCH_SOFT_DIRTY
107 select CLOCKSOURCE_WATCHDOG
108 select GENERIC_CLOCKEVENTS
109 select ARCH_CLOCKSOURCE_DATA if X86_64
110 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
111 select GENERIC_TIME_VSYSCALL if X86_64
112 select KTIME_SCALAR if X86_32
113 select GENERIC_STRNCPY_FROM_USER
114 select GENERIC_STRNLEN_USER
115 select HAVE_CONTEXT_TRACKING if X86_64
116 select HAVE_IRQ_TIME_ACCOUNTING
117 select VIRT_TO_BUS
118 select MODULES_USE_ELF_REL if X86_32
119 select MODULES_USE_ELF_RELA if X86_64
120 select CLONE_BACKWARDS if X86_32
121 select ARCH_USE_BUILTIN_BSWAP
122 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
123 select OLD_SIGACTION if X86_32
124 select COMPAT_OLD_SIGACTION if IA32_EMULATION
125 select RTC_LIB
126 select HAVE_DEBUG_STACKOVERFLOW
127
128 config INSTRUCTION_DECODER
129 def_bool y
130 depends on KPROBES || PERF_EVENTS || UPROBES
131
132 config OUTPUT_FORMAT
133 string
134 default "elf32-i386" if X86_32
135 default "elf64-x86-64" if X86_64
136
137 config ARCH_DEFCONFIG
138 string
139 default "arch/x86/configs/i386_defconfig" if X86_32
140 default "arch/x86/configs/x86_64_defconfig" if X86_64
141
142 config LOCKDEP_SUPPORT
143 def_bool y
144
145 config STACKTRACE_SUPPORT
146 def_bool y
147
148 config HAVE_LATENCYTOP_SUPPORT
149 def_bool y
150
151 config MMU
152 def_bool y
153
154 config SBUS
155 bool
156
157 config NEED_DMA_MAP_STATE
158 def_bool y
159 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
160
161 config NEED_SG_DMA_LENGTH
162 def_bool y
163
164 config GENERIC_ISA_DMA
165 def_bool y
166 depends on ISA_DMA_API
167
168 config GENERIC_BUG
169 def_bool y
170 depends on BUG
171 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
172
173 config GENERIC_BUG_RELATIVE_POINTERS
174 bool
175
176 config GENERIC_HWEIGHT
177 def_bool y
178
179 config ARCH_MAY_HAVE_PC_FDC
180 def_bool y
181 depends on ISA_DMA_API
182
183 config RWSEM_XCHGADD_ALGORITHM
184 def_bool y
185
186 config GENERIC_CALIBRATE_DELAY
187 def_bool y
188
189 config ARCH_HAS_CPU_RELAX
190 def_bool y
191
192 config ARCH_HAS_CACHE_LINE_SIZE
193 def_bool y
194
195 config ARCH_HAS_CPU_AUTOPROBE
196 def_bool y
197
198 config HAVE_SETUP_PER_CPU_AREA
199 def_bool y
200
201 config NEED_PER_CPU_EMBED_FIRST_CHUNK
202 def_bool y
203
204 config NEED_PER_CPU_PAGE_FIRST_CHUNK
205 def_bool y
206
207 config ARCH_HIBERNATION_POSSIBLE
208 def_bool y
209
210 config ARCH_SUSPEND_POSSIBLE
211 def_bool y
212
213 config ARCH_WANT_HUGE_PMD_SHARE
214 def_bool y
215
216 config ARCH_WANT_GENERAL_HUGETLB
217 def_bool y
218
219 config ZONE_DMA32
220 bool
221 default X86_64
222
223 config AUDIT_ARCH
224 bool
225 default X86_64
226
227 config ARCH_SUPPORTS_OPTIMIZED_INLINING
228 def_bool y
229
230 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
231 def_bool y
232
233 config HAVE_INTEL_TXT
234 def_bool y
235 depends on INTEL_IOMMU && ACPI
236
237 config X86_32_SMP
238 def_bool y
239 depends on X86_32 && SMP
240
241 config X86_64_SMP
242 def_bool y
243 depends on X86_64 && SMP
244
245 config X86_HT
246 def_bool y
247 depends on SMP
248
249 config X86_32_LAZY_GS
250 def_bool y
251 depends on X86_32 && !CC_STACKPROTECTOR
252
253 config ARCH_HWEIGHT_CFLAGS
254 string
255 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
256 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
257
258 config ARCH_CPU_PROBE_RELEASE
259 def_bool y
260 depends on HOTPLUG_CPU
261
262 config ARCH_SUPPORTS_UPROBES
263 def_bool y
264
265 source "init/Kconfig"
266 source "kernel/Kconfig.freezer"
267
268 menu "Processor type and features"
269
270 config ZONE_DMA
271 bool "DMA memory allocation support" if EXPERT
272 default y
273 help
274 DMA memory allocation support allows devices with less than 32-bit
275 addressing to allocate within the first 16MB of address space.
276 Disable if no such devices will be used.
277
278 If unsure, say Y.
279
280 config SMP
281 bool "Symmetric multi-processing support"
282 ---help---
283 This enables support for systems with more than one CPU. If you have
284 a system with only one CPU, like most personal computers, say N. If
285 you have a system with more than one CPU, say Y.
286
287 If you say N here, the kernel will run on single and multiprocessor
288 machines, but will use only one CPU of a multiprocessor machine. If
289 you say Y here, the kernel will run on many, but not all,
290 singleprocessor machines. On a singleprocessor machine, the kernel
291 will run faster if you say N here.
292
293 Note that if you say Y here and choose architecture "586" or
294 "Pentium" under "Processor family", the kernel will not work on 486
295 architectures. Similarly, multiprocessor kernels for the "PPro"
296 architecture may not work on all Pentium based boards.
297
298 People using multiprocessor machines who say Y here should also say
299 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
300 Management" code will be disabled if you say Y here.
301
302 See also <file:Documentation/x86/i386/IO-APIC.txt>,
303 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
304 <http://www.tldp.org/docs.html#howto>.
305
306 If you don't know what to do here, say N.
307
308 config X86_X2APIC
309 bool "Support x2apic"
310 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
311 ---help---
312 This enables x2apic support on CPUs that have this feature.
313
314 This allows 32-bit apic IDs (so it can support very large systems),
315 and accesses the local apic via MSRs not via mmio.
316
317 If you don't know what to do here, say N.
318
319 config X86_MPPARSE
320 bool "Enable MPS table" if ACPI || SFI
321 default y
322 depends on X86_LOCAL_APIC
323 ---help---
324 For old smp systems that do not have proper acpi support. Newer systems
325 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
326
327 config X86_BIGSMP
328 bool "Support for big SMP systems with more than 8 CPUs"
329 depends on X86_32 && SMP
330 ---help---
331 This option is needed for the systems that have more than 8 CPUs
332
333 config GOLDFISH
334 def_bool y
335 depends on X86_GOLDFISH
336
337 if X86_32
338 config X86_EXTENDED_PLATFORM
339 bool "Support for extended (non-PC) x86 platforms"
340 default y
341 ---help---
342 If you disable this option then the kernel will only support
343 standard PC platforms. (which covers the vast majority of
344 systems out there.)
345
346 If you enable this option then you'll be able to select support
347 for the following (non-PC) 32 bit x86 platforms:
348 Goldfish (Android emulator)
349 AMD Elan
350 NUMAQ (IBM/Sequent)
351 RDC R-321x SoC
352 SGI 320/540 (Visual Workstation)
353 STA2X11-based (e.g. Northville)
354 Summit/EXA (IBM x440)
355 Unisys ES7000 IA32 series
356 Moorestown MID devices
357
358 If you have one of these systems, or if you want to build a
359 generic distribution kernel, say Y here - otherwise say N.
360 endif
361
362 if X86_64
363 config X86_EXTENDED_PLATFORM
364 bool "Support for extended (non-PC) x86 platforms"
365 default y
366 ---help---
367 If you disable this option then the kernel will only support
368 standard PC platforms. (which covers the vast majority of
369 systems out there.)
370
371 If you enable this option then you'll be able to select support
372 for the following (non-PC) 64 bit x86 platforms:
373 Numascale NumaChip
374 ScaleMP vSMP
375 SGI Ultraviolet
376
377 If you have one of these systems, or if you want to build a
378 generic distribution kernel, say Y here - otherwise say N.
379 endif
380 # This is an alphabetically sorted list of 64 bit extended platforms
381 # Please maintain the alphabetic order if and when there are additions
382 config X86_NUMACHIP
383 bool "Numascale NumaChip"
384 depends on X86_64
385 depends on X86_EXTENDED_PLATFORM
386 depends on NUMA
387 depends on SMP
388 depends on X86_X2APIC
389 depends on PCI_MMCONFIG
390 ---help---
391 Adds support for Numascale NumaChip large-SMP systems. Needed to
392 enable more than ~168 cores.
393 If you don't have one of these, you should say N here.
394
395 config X86_VSMP
396 bool "ScaleMP vSMP"
397 select HYPERVISOR_GUEST
398 select PARAVIRT
399 depends on X86_64 && PCI
400 depends on X86_EXTENDED_PLATFORM
401 depends on SMP
402 ---help---
403 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
404 supposed to run on these EM64T-based machines. Only choose this option
405 if you have one of these machines.
406
407 config X86_UV
408 bool "SGI Ultraviolet"
409 depends on X86_64
410 depends on X86_EXTENDED_PLATFORM
411 depends on NUMA
412 depends on X86_X2APIC
413 ---help---
414 This option is needed in order to support SGI Ultraviolet systems.
415 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
418 # Please maintain the alphabetic order if and when there are additions
419
420 config X86_GOLDFISH
421 bool "Goldfish (Virtual Platform)"
422 depends on X86_32
423 depends on X86_EXTENDED_PLATFORM
424 ---help---
425 Enable support for the Goldfish virtual platform used primarily
426 for Android development. Unless you are building for the Android
427 Goldfish emulator say N here.
428
429 config X86_INTEL_CE
430 bool "CE4100 TV platform"
431 depends on PCI
432 depends on PCI_GODIRECT
433 depends on X86_32
434 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
436 select OF
437 select OF_EARLY_FLATTREE
438 select IRQ_DOMAIN
439 ---help---
440 Select for the Intel CE media processor (CE4100) SOC.
441 This option compiles in support for the CE4100 SOC for settop
442 boxes and media devices.
443
444 config X86_WANT_INTEL_MID
445 bool "Intel MID platform support"
446 depends on X86_32
447 depends on X86_EXTENDED_PLATFORM
448 ---help---
449 Select to build a kernel capable of supporting Intel MID platform
450 systems which do not have the PCI legacy interfaces (Moorestown,
451 Medfield). If you are building for a PC class system say N here.
452
453 if X86_WANT_INTEL_MID
454
455 config X86_INTEL_MID
456 bool
457
458 config X86_MDFLD
459 bool "Medfield MID platform"
460 depends on PCI
461 depends on PCI_GOANY
462 depends on X86_IO_APIC
463 select X86_INTEL_MID
464 select SFI
465 select DW_APB_TIMER
466 select APB_TIMER
467 select I2C
468 select SPI
469 select INTEL_SCU_IPC
470 select X86_PLATFORM_DEVICES
471 select MFD_INTEL_MSIC
472 ---help---
473 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
474 Internet Device(MID) platform.
475 Unlike standard x86 PCs, Medfield does not have many legacy devices
476 nor standard legacy replacement devices/features. e.g. Medfield does
477 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
478
479 endif
480
481 config X86_INTEL_LPSS
482 bool "Intel Low Power Subsystem Support"
483 depends on ACPI
484 select COMMON_CLK
485 ---help---
486 Select to build support for Intel Low Power Subsystem such as
487 found on Intel Lynxpoint PCH. Selecting this option enables
488 things like clock tree (common clock framework) which are needed
489 by the LPSS peripheral drivers.
490
491 config X86_RDC321X
492 bool "RDC R-321x SoC"
493 depends on X86_32
494 depends on X86_EXTENDED_PLATFORM
495 select M486
496 select X86_REBOOTFIXUPS
497 ---help---
498 This option is needed for RDC R-321x system-on-chip, also known
499 as R-8610-(G).
500 If you don't have one of these chips, you should say N here.
501
502 config X86_32_NON_STANDARD
503 bool "Support non-standard 32-bit SMP architectures"
504 depends on X86_32 && SMP
505 depends on X86_EXTENDED_PLATFORM
506 ---help---
507 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
508 STA2X11, default subarchitectures. It is intended for a generic
509 binary kernel. If you select them all, kernel will probe it
510 one by one and will fallback to default.
511
512 # Alphabetically sorted list of Non standard 32 bit platforms
513
514 config X86_NUMAQ
515 bool "NUMAQ (IBM/Sequent)"
516 depends on X86_32_NON_STANDARD
517 depends on PCI
518 select NUMA
519 select X86_MPPARSE
520 ---help---
521 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
522 NUMA multiquad box. This changes the way that processors are
523 bootstrapped, and uses Clustered Logical APIC addressing mode instead
524 of Flat Logical. You will need a new lynxer.elf file to flash your
525 firmware with - send email to <Martin.Bligh@us.ibm.com>.
526
527 config X86_SUPPORTS_MEMORY_FAILURE
528 def_bool y
529 # MCE code calls memory_failure():
530 depends on X86_MCE
531 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
532 depends on !X86_NUMAQ
533 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
534 depends on X86_64 || !SPARSEMEM
535 select ARCH_SUPPORTS_MEMORY_FAILURE
536
537 config X86_VISWS
538 bool "SGI 320/540 (Visual Workstation)"
539 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
540 depends on X86_32_NON_STANDARD
541 ---help---
542 The SGI Visual Workstation series is an IA32-based workstation
543 based on SGI systems chips with some legacy PC hardware attached.
544
545 Say Y here to create a kernel to run on the SGI 320 or 540.
546
547 A kernel compiled for the Visual Workstation will run on general
548 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
549
550 config STA2X11
551 bool "STA2X11 Companion Chip Support"
552 depends on X86_32_NON_STANDARD && PCI
553 select X86_DEV_DMA_OPS
554 select X86_DMA_REMAP
555 select SWIOTLB
556 select MFD_STA2X11
557 select ARCH_REQUIRE_GPIOLIB
558 default n
559 ---help---
560 This adds support for boards based on the STA2X11 IO-Hub,
561 a.k.a. "ConneXt". The chip is used in place of the standard
562 PC chipset, so all "standard" peripherals are missing. If this
563 option is selected the kernel will still be able to boot on
564 standard PC machines.
565
566 config X86_SUMMIT
567 bool "Summit/EXA (IBM x440)"
568 depends on X86_32_NON_STANDARD
569 ---help---
570 This option is needed for IBM systems that use the Summit/EXA chipset.
571 In particular, it is needed for the x440.
572
573 config X86_ES7000
574 bool "Unisys ES7000 IA32 series"
575 depends on X86_32_NON_STANDARD && X86_BIGSMP
576 ---help---
577 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
578 supposed to run on an IA32-based Unisys ES7000 system.
579
580 config X86_32_IRIS
581 tristate "Eurobraille/Iris poweroff module"
582 depends on X86_32
583 ---help---
584 The Iris machines from EuroBraille do not have APM or ACPI support
585 to shut themselves down properly. A special I/O sequence is
586 needed to do so, which is what this module does at
587 kernel shutdown.
588
589 This is only for Iris machines from EuroBraille.
590
591 If unused, say N.
592
593 config SCHED_OMIT_FRAME_POINTER
594 def_bool y
595 prompt "Single-depth WCHAN output"
596 depends on X86
597 ---help---
598 Calculate simpler /proc/<PID>/wchan values. If this option
599 is disabled then wchan values will recurse back to the
600 caller function. This provides more accurate wchan values,
601 at the expense of slightly more scheduling overhead.
602
603 If in doubt, say "Y".
604
605 menuconfig HYPERVISOR_GUEST
606 bool "Linux guest support"
607 ---help---
608 Say Y here to enable options for running Linux under various hyper-
609 visors. This option enables basic hypervisor detection and platform
610 setup.
611
612 If you say N, all options in this submenu will be skipped and
613 disabled, and Linux guest support won't be built in.
614
615 if HYPERVISOR_GUEST
616
617 config PARAVIRT
618 bool "Enable paravirtualization code"
619 ---help---
620 This changes the kernel so it can modify itself when it is run
621 under a hypervisor, potentially improving performance significantly
622 over full virtualization. However, when run without a hypervisor
623 the kernel is theoretically slower and slightly larger.
624
625 config PARAVIRT_DEBUG
626 bool "paravirt-ops debugging"
627 depends on PARAVIRT && DEBUG_KERNEL
628 ---help---
629 Enable to debug paravirt_ops internals. Specifically, BUG if
630 a paravirt_op is missing when it is called.
631
632 config PARAVIRT_SPINLOCKS
633 bool "Paravirtualization layer for spinlocks"
634 depends on PARAVIRT && SMP
635 select UNINLINE_SPIN_UNLOCK
636 ---help---
637 Paravirtualized spinlocks allow a pvops backend to replace the
638 spinlock implementation with something virtualization-friendly
639 (for example, block the virtual CPU rather than spinning).
640
641 Unfortunately the downside is an up to 5% performance hit on
642 native kernels, with various workloads.
643
644 If you are unsure how to answer this question, answer N.
645
646 source "arch/x86/xen/Kconfig"
647
648 config KVM_GUEST
649 bool "KVM Guest support (including kvmclock)"
650 depends on PARAVIRT
651 select PARAVIRT_CLOCK
652 default y
653 ---help---
654 This option enables various optimizations for running under the KVM
655 hypervisor. It includes a paravirtualized clock, so that instead
656 of relying on a PIT (or probably other) emulation by the
657 underlying device model, the host provides the guest with
658 timing infrastructure such as time of day, and system time
659
660 config KVM_DEBUG_FS
661 bool "Enable debug information for KVM Guests in debugfs"
662 depends on KVM_GUEST && DEBUG_FS
663 default n
664 ---help---
665 This option enables collection of various statistics for KVM guest.
666 Statistics are displayed in debugfs filesystem. Enabling this option
667 may incur significant overhead.
668
669 source "arch/x86/lguest/Kconfig"
670
671 config PARAVIRT_TIME_ACCOUNTING
672 bool "Paravirtual steal time accounting"
673 depends on PARAVIRT
674 default n
675 ---help---
676 Select this option to enable fine granularity task steal time
677 accounting. Time spent executing other tasks in parallel with
678 the current vCPU is discounted from the vCPU power. To account for
679 that, there can be a small performance impact.
680
681 If in doubt, say N here.
682
683 config PARAVIRT_CLOCK
684 bool
685
686 endif #HYPERVISOR_GUEST
687
688 config NO_BOOTMEM
689 def_bool y
690
691 config MEMTEST
692 bool "Memtest"
693 ---help---
694 This option adds a kernel parameter 'memtest', which allows memtest
695 to be set.
696 memtest=0, mean disabled; -- default
697 memtest=1, mean do 1 test pattern;
698 ...
699 memtest=4, mean do 4 test patterns.
700 If you are unsure how to answer this question, answer N.
701
702 config X86_SUMMIT_NUMA
703 def_bool y
704 depends on X86_32 && NUMA && X86_32_NON_STANDARD
705
706 config X86_CYCLONE_TIMER
707 def_bool y
708 depends on X86_SUMMIT
709
710 source "arch/x86/Kconfig.cpu"
711
712 config HPET_TIMER
713 def_bool X86_64
714 prompt "HPET Timer Support" if X86_32
715 ---help---
716 Use the IA-PC HPET (High Precision Event Timer) to manage
717 time in preference to the PIT and RTC, if a HPET is
718 present.
719 HPET is the next generation timer replacing legacy 8254s.
720 The HPET provides a stable time base on SMP
721 systems, unlike the TSC, but it is more expensive to access,
722 as it is off-chip. You can find the HPET spec at
723 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
724
725 You can safely choose Y here. However, HPET will only be
726 activated if the platform and the BIOS support this feature.
727 Otherwise the 8254 will be used for timing services.
728
729 Choose N to continue using the legacy 8254 timer.
730
731 config HPET_EMULATE_RTC
732 def_bool y
733 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
734
735 config APB_TIMER
736 def_bool y if X86_INTEL_MID
737 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
738 select DW_APB_TIMER
739 depends on X86_INTEL_MID && SFI
740 help
741 APB timer is the replacement for 8254, HPET on X86 MID platforms.
742 The APBT provides a stable time base on SMP
743 systems, unlike the TSC, but it is more expensive to access,
744 as it is off-chip. APB timers are always running regardless of CPU
745 C states, they are used as per CPU clockevent device when possible.
746
747 # Mark as expert because too many people got it wrong.
748 # The code disables itself when not needed.
749 config DMI
750 default y
751 bool "Enable DMI scanning" if EXPERT
752 ---help---
753 Enabled scanning of DMI to identify machine quirks. Say Y
754 here unless you have verified that your setup is not
755 affected by entries in the DMI blacklist. Required by PNP
756 BIOS code.
757
758 config GART_IOMMU
759 bool "GART IOMMU support" if EXPERT
760 default y
761 select SWIOTLB
762 depends on X86_64 && PCI && AMD_NB
763 ---help---
764 Support for full DMA access of devices with 32bit memory access only
765 on systems with more than 3GB. This is usually needed for USB,
766 sound, many IDE/SATA chipsets and some other devices.
767 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
768 based hardware IOMMU and a software bounce buffer based IOMMU used
769 on Intel systems and as fallback.
770 The code is only active when needed (enough memory and limited
771 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
772 too.
773
774 config CALGARY_IOMMU
775 bool "IBM Calgary IOMMU support"
776 select SWIOTLB
777 depends on X86_64 && PCI
778 ---help---
779 Support for hardware IOMMUs in IBM's xSeries x366 and x460
780 systems. Needed to run systems with more than 3GB of memory
781 properly with 32-bit PCI devices that do not support DAC
782 (Double Address Cycle). Calgary also supports bus level
783 isolation, where all DMAs pass through the IOMMU. This
784 prevents them from going anywhere except their intended
785 destination. This catches hard-to-find kernel bugs and
786 mis-behaving drivers and devices that do not use the DMA-API
787 properly to set up their DMA buffers. The IOMMU can be
788 turned off at boot time with the iommu=off parameter.
789 Normally the kernel will make the right choice by itself.
790 If unsure, say Y.
791
792 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
793 def_bool y
794 prompt "Should Calgary be enabled by default?"
795 depends on CALGARY_IOMMU
796 ---help---
797 Should Calgary be enabled by default? if you choose 'y', Calgary
798 will be used (if it exists). If you choose 'n', Calgary will not be
799 used even if it exists. If you choose 'n' and would like to use
800 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
801 If unsure, say Y.
802
803 # need this always selected by IOMMU for the VIA workaround
804 config SWIOTLB
805 def_bool y if X86_64
806 ---help---
807 Support for software bounce buffers used on x86-64 systems
808 which don't have a hardware IOMMU. Using this PCI devices
809 which can only access 32-bits of memory can be used on systems
810 with more than 3 GB of memory.
811 If unsure, say Y.
812
813 config IOMMU_HELPER
814 def_bool y
815 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
816
817 config MAXSMP
818 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
819 depends on X86_64 && SMP && DEBUG_KERNEL
820 select CPUMASK_OFFSTACK
821 ---help---
822 Enable maximum number of CPUS and NUMA Nodes for this architecture.
823 If unsure, say N.
824
825 config NR_CPUS
826 int "Maximum number of CPUs" if SMP && !MAXSMP
827 range 2 8 if SMP && X86_32 && !X86_BIGSMP
828 range 2 512 if SMP && !MAXSMP
829 default "1" if !SMP
830 default "4096" if MAXSMP
831 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
832 default "8" if SMP
833 ---help---
834 This allows you to specify the maximum number of CPUs which this
835 kernel will support. The maximum supported value is 512 and the
836 minimum value which makes sense is 2.
837
838 This is purely to save memory - each supported CPU adds
839 approximately eight kilobytes to the kernel image.
840
841 config SCHED_SMT
842 bool "SMT (Hyperthreading) scheduler support"
843 depends on X86_HT
844 ---help---
845 SMT scheduler support improves the CPU scheduler's decision making
846 when dealing with Intel Pentium 4 chips with HyperThreading at a
847 cost of slightly increased overhead in some places. If unsure say
848 N here.
849
850 config SCHED_MC
851 def_bool y
852 prompt "Multi-core scheduler support"
853 depends on X86_HT
854 ---help---
855 Multi-core scheduler support improves the CPU scheduler's decision
856 making when dealing with multi-core CPU chips at a cost of slightly
857 increased overhead in some places. If unsure say N here.
858
859 source "kernel/Kconfig.preempt"
860
861 config X86_UP_APIC
862 bool "Local APIC support on uniprocessors"
863 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
864 ---help---
865 A local APIC (Advanced Programmable Interrupt Controller) is an
866 integrated interrupt controller in the CPU. If you have a single-CPU
867 system which has a processor with a local APIC, you can say Y here to
868 enable and use it. If you say Y here even though your machine doesn't
869 have a local APIC, then the kernel will still run with no slowdown at
870 all. The local APIC supports CPU-generated self-interrupts (timer,
871 performance counters), and the NMI watchdog which detects hard
872 lockups.
873
874 config X86_UP_IOAPIC
875 bool "IO-APIC support on uniprocessors"
876 depends on X86_UP_APIC
877 ---help---
878 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
879 SMP-capable replacement for PC-style interrupt controllers. Most
880 SMP systems and many recent uniprocessor systems have one.
881
882 If you have a single-CPU system with an IO-APIC, you can say Y here
883 to use it. If you say Y here even though your machine doesn't have
884 an IO-APIC, then the kernel will still run with no slowdown at all.
885
886 config X86_LOCAL_APIC
887 def_bool y
888 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
889
890 config X86_IO_APIC
891 def_bool y
892 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
893
894 config X86_VISWS_APIC
895 def_bool y
896 depends on X86_32 && X86_VISWS
897
898 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
899 bool "Reroute for broken boot IRQs"
900 depends on X86_IO_APIC
901 ---help---
902 This option enables a workaround that fixes a source of
903 spurious interrupts. This is recommended when threaded
904 interrupt handling is used on systems where the generation of
905 superfluous "boot interrupts" cannot be disabled.
906
907 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
908 entry in the chipset's IO-APIC is masked (as, e.g. the RT
909 kernel does during interrupt handling). On chipsets where this
910 boot IRQ generation cannot be disabled, this workaround keeps
911 the original IRQ line masked so that only the equivalent "boot
912 IRQ" is delivered to the CPUs. The workaround also tells the
913 kernel to set up the IRQ handler on the boot IRQ line. In this
914 way only one interrupt is delivered to the kernel. Otherwise
915 the spurious second interrupt may cause the kernel to bring
916 down (vital) interrupt lines.
917
918 Only affects "broken" chipsets. Interrupt sharing may be
919 increased on these systems.
920
921 config X86_MCE
922 bool "Machine Check / overheating reporting"
923 default y
924 ---help---
925 Machine Check support allows the processor to notify the
926 kernel if it detects a problem (e.g. overheating, data corruption).
927 The action the kernel takes depends on the severity of the problem,
928 ranging from warning messages to halting the machine.
929
930 config X86_MCE_INTEL
931 def_bool y
932 prompt "Intel MCE features"
933 depends on X86_MCE && X86_LOCAL_APIC
934 ---help---
935 Additional support for intel specific MCE features such as
936 the thermal monitor.
937
938 config X86_MCE_AMD
939 def_bool y
940 prompt "AMD MCE features"
941 depends on X86_MCE && X86_LOCAL_APIC
942 ---help---
943 Additional support for AMD specific MCE features such as
944 the DRAM Error Threshold.
945
946 config X86_ANCIENT_MCE
947 bool "Support for old Pentium 5 / WinChip machine checks"
948 depends on X86_32 && X86_MCE
949 ---help---
950 Include support for machine check handling on old Pentium 5 or WinChip
951 systems. These typically need to be enabled explicitely on the command
952 line.
953
954 config X86_MCE_THRESHOLD
955 depends on X86_MCE_AMD || X86_MCE_INTEL
956 def_bool y
957
958 config X86_MCE_INJECT
959 depends on X86_MCE
960 tristate "Machine check injector support"
961 ---help---
962 Provide support for injecting machine checks for testing purposes.
963 If you don't know what a machine check is and you don't do kernel
964 QA it is safe to say n.
965
966 config X86_THERMAL_VECTOR
967 def_bool y
968 depends on X86_MCE_INTEL
969
970 config VM86
971 bool "Enable VM86 support" if EXPERT
972 default y
973 depends on X86_32
974 ---help---
975 This option is required by programs like DOSEMU to run 16-bit legacy
976 code on X86 processors. It also may be needed by software like
977 XFree86 to initialize some video cards via BIOS. Disabling this
978 option saves about 6k.
979
980 config TOSHIBA
981 tristate "Toshiba Laptop support"
982 depends on X86_32
983 ---help---
984 This adds a driver to safely access the System Management Mode of
985 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
986 not work on models with a Phoenix BIOS. The System Management Mode
987 is used to set the BIOS and power saving options on Toshiba portables.
988
989 For information on utilities to make use of this driver see the
990 Toshiba Linux utilities web site at:
991 <http://www.buzzard.org.uk/toshiba/>.
992
993 Say Y if you intend to run this kernel on a Toshiba portable.
994 Say N otherwise.
995
996 config I8K
997 tristate "Dell laptop support"
998 select HWMON
999 ---help---
1000 This adds a driver to safely access the System Management Mode
1001 of the CPU on the Dell Inspiron 8000. The System Management Mode
1002 is used to read cpu temperature and cooling fan status and to
1003 control the fans on the I8K portables.
1004
1005 This driver has been tested only on the Inspiron 8000 but it may
1006 also work with other Dell laptops. You can force loading on other
1007 models by passing the parameter `force=1' to the module. Use at
1008 your own risk.
1009
1010 For information on utilities to make use of this driver see the
1011 I8K Linux utilities web site at:
1012 <http://people.debian.org/~dz/i8k/>
1013
1014 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1015 Say N otherwise.
1016
1017 config X86_REBOOTFIXUPS
1018 bool "Enable X86 board specific fixups for reboot"
1019 depends on X86_32
1020 ---help---
1021 This enables chipset and/or board specific fixups to be done
1022 in order to get reboot to work correctly. This is only needed on
1023 some combinations of hardware and BIOS. The symptom, for which
1024 this config is intended, is when reboot ends with a stalled/hung
1025 system.
1026
1027 Currently, the only fixup is for the Geode machines using
1028 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1029
1030 Say Y if you want to enable the fixup. Currently, it's safe to
1031 enable this option even if you don't need it.
1032 Say N otherwise.
1033
1034 config MICROCODE
1035 tristate "CPU microcode loading support"
1036 select FW_LOADER
1037 ---help---
1038
1039 If you say Y here, you will be able to update the microcode on
1040 certain Intel and AMD processors. The Intel support is for the
1041 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1042 Xeon etc. The AMD support is for families 0x10 and later. You will
1043 obviously need the actual microcode binary data itself which is not
1044 shipped with the Linux kernel.
1045
1046 This option selects the general module only, you need to select
1047 at least one vendor specific module as well.
1048
1049 To compile this driver as a module, choose M here: the module
1050 will be called microcode.
1051
1052 config MICROCODE_INTEL
1053 bool "Intel microcode loading support"
1054 depends on MICROCODE
1055 default MICROCODE
1056 select FW_LOADER
1057 ---help---
1058 This options enables microcode patch loading support for Intel
1059 processors.
1060
1061 For latest news and information on obtaining all the required
1062 Intel ingredients for this driver, check:
1063 <http://www.urbanmyth.org/microcode/>.
1064
1065 config MICROCODE_AMD
1066 bool "AMD microcode loading support"
1067 depends on MICROCODE
1068 select FW_LOADER
1069 ---help---
1070 If you select this option, microcode patch loading support for AMD
1071 processors will be enabled.
1072
1073 config MICROCODE_OLD_INTERFACE
1074 def_bool y
1075 depends on MICROCODE
1076
1077 config MICROCODE_INTEL_LIB
1078 def_bool y
1079 depends on MICROCODE_INTEL
1080
1081 config MICROCODE_INTEL_EARLY
1082 def_bool n
1083
1084 config MICROCODE_AMD_EARLY
1085 def_bool n
1086
1087 config MICROCODE_EARLY
1088 bool "Early load microcode"
1089 depends on MICROCODE=y && BLK_DEV_INITRD
1090 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1091 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1092 default y
1093 help
1094 This option provides functionality to read additional microcode data
1095 at the beginning of initrd image. The data tells kernel to load
1096 microcode to CPU's as early as possible. No functional change if no
1097 microcode data is glued to the initrd, therefore it's safe to say Y.
1098
1099 config X86_MSR
1100 tristate "/dev/cpu/*/msr - Model-specific register support"
1101 ---help---
1102 This device gives privileged processes access to the x86
1103 Model-Specific Registers (MSRs). It is a character device with
1104 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1105 MSR accesses are directed to a specific CPU on multi-processor
1106 systems.
1107
1108 config X86_CPUID
1109 tristate "/dev/cpu/*/cpuid - CPU information support"
1110 ---help---
1111 This device gives processes access to the x86 CPUID instruction to
1112 be executed on a specific processor. It is a character device
1113 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1114 /dev/cpu/31/cpuid.
1115
1116 choice
1117 prompt "High Memory Support"
1118 default HIGHMEM64G if X86_NUMAQ
1119 default HIGHMEM4G
1120 depends on X86_32
1121
1122 config NOHIGHMEM
1123 bool "off"
1124 depends on !X86_NUMAQ
1125 ---help---
1126 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1127 However, the address space of 32-bit x86 processors is only 4
1128 Gigabytes large. That means that, if you have a large amount of
1129 physical memory, not all of it can be "permanently mapped" by the
1130 kernel. The physical memory that's not permanently mapped is called
1131 "high memory".
1132
1133 If you are compiling a kernel which will never run on a machine with
1134 more than 1 Gigabyte total physical RAM, answer "off" here (default
1135 choice and suitable for most users). This will result in a "3GB/1GB"
1136 split: 3GB are mapped so that each process sees a 3GB virtual memory
1137 space and the remaining part of the 4GB virtual memory space is used
1138 by the kernel to permanently map as much physical memory as
1139 possible.
1140
1141 If the machine has between 1 and 4 Gigabytes physical RAM, then
1142 answer "4GB" here.
1143
1144 If more than 4 Gigabytes is used then answer "64GB" here. This
1145 selection turns Intel PAE (Physical Address Extension) mode on.
1146 PAE implements 3-level paging on IA32 processors. PAE is fully
1147 supported by Linux, PAE mode is implemented on all recent Intel
1148 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1149 then the kernel will not boot on CPUs that don't support PAE!
1150
1151 The actual amount of total physical memory will either be
1152 auto detected or can be forced by using a kernel command line option
1153 such as "mem=256M". (Try "man bootparam" or see the documentation of
1154 your boot loader (lilo or loadlin) about how to pass options to the
1155 kernel at boot time.)
1156
1157 If unsure, say "off".
1158
1159 config HIGHMEM4G
1160 bool "4GB"
1161 depends on !X86_NUMAQ
1162 ---help---
1163 Select this if you have a 32-bit processor and between 1 and 4
1164 gigabytes of physical RAM.
1165
1166 config HIGHMEM64G
1167 bool "64GB"
1168 depends on !M486
1169 select X86_PAE
1170 ---help---
1171 Select this if you have a 32-bit processor and more than 4
1172 gigabytes of physical RAM.
1173
1174 endchoice
1175
1176 choice
1177 prompt "Memory split" if EXPERT
1178 default VMSPLIT_3G
1179 depends on X86_32
1180 ---help---
1181 Select the desired split between kernel and user memory.
1182
1183 If the address range available to the kernel is less than the
1184 physical memory installed, the remaining memory will be available
1185 as "high memory". Accessing high memory is a little more costly
1186 than low memory, as it needs to be mapped into the kernel first.
1187 Note that increasing the kernel address space limits the range
1188 available to user programs, making the address space there
1189 tighter. Selecting anything other than the default 3G/1G split
1190 will also likely make your kernel incompatible with binary-only
1191 kernel modules.
1192
1193 If you are not absolutely sure what you are doing, leave this
1194 option alone!
1195
1196 config VMSPLIT_3G
1197 bool "3G/1G user/kernel split"
1198 config VMSPLIT_3G_OPT
1199 depends on !X86_PAE
1200 bool "3G/1G user/kernel split (for full 1G low memory)"
1201 config VMSPLIT_2G
1202 bool "2G/2G user/kernel split"
1203 config VMSPLIT_2G_OPT
1204 depends on !X86_PAE
1205 bool "2G/2G user/kernel split (for full 2G low memory)"
1206 config VMSPLIT_1G
1207 bool "1G/3G user/kernel split"
1208 endchoice
1209
1210 config PAGE_OFFSET
1211 hex
1212 default 0xB0000000 if VMSPLIT_3G_OPT
1213 default 0x80000000 if VMSPLIT_2G
1214 default 0x78000000 if VMSPLIT_2G_OPT
1215 default 0x40000000 if VMSPLIT_1G
1216 default 0xC0000000
1217 depends on X86_32
1218
1219 config HIGHMEM
1220 def_bool y
1221 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1222
1223 config X86_PAE
1224 bool "PAE (Physical Address Extension) Support"
1225 depends on X86_32 && !HIGHMEM4G
1226 ---help---
1227 PAE is required for NX support, and furthermore enables
1228 larger swapspace support for non-overcommit purposes. It
1229 has the cost of more pagetable lookup overhead, and also
1230 consumes more pagetable space per process.
1231
1232 config ARCH_PHYS_ADDR_T_64BIT
1233 def_bool y
1234 depends on X86_64 || X86_PAE
1235
1236 config ARCH_DMA_ADDR_T_64BIT
1237 def_bool y
1238 depends on X86_64 || HIGHMEM64G
1239
1240 config DIRECT_GBPAGES
1241 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1242 default y
1243 depends on X86_64
1244 ---help---
1245 Allow the kernel linear mapping to use 1GB pages on CPUs that
1246 support it. This can improve the kernel's performance a tiny bit by
1247 reducing TLB pressure. If in doubt, say "Y".
1248
1249 # Common NUMA Features
1250 config NUMA
1251 bool "Numa Memory Allocation and Scheduler Support"
1252 depends on SMP
1253 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1254 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1255 ---help---
1256 Enable NUMA (Non Uniform Memory Access) support.
1257
1258 The kernel will try to allocate memory used by a CPU on the
1259 local memory controller of the CPU and add some more
1260 NUMA awareness to the kernel.
1261
1262 For 64-bit this is recommended if the system is Intel Core i7
1263 (or later), AMD Opteron, or EM64T NUMA.
1264
1265 For 32-bit this is only needed on (rare) 32-bit-only platforms
1266 that support NUMA topologies, such as NUMAQ / Summit, or if you
1267 boot a 32-bit kernel on a 64-bit NUMA platform.
1268
1269 Otherwise, you should say N.
1270
1271 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1272 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1273
1274 config AMD_NUMA
1275 def_bool y
1276 prompt "Old style AMD Opteron NUMA detection"
1277 depends on X86_64 && NUMA && PCI
1278 ---help---
1279 Enable AMD NUMA node topology detection. You should say Y here if
1280 you have a multi processor AMD system. This uses an old method to
1281 read the NUMA configuration directly from the builtin Northbridge
1282 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1283 which also takes priority if both are compiled in.
1284
1285 config X86_64_ACPI_NUMA
1286 def_bool y
1287 prompt "ACPI NUMA detection"
1288 depends on X86_64 && NUMA && ACPI && PCI
1289 select ACPI_NUMA
1290 ---help---
1291 Enable ACPI SRAT based node topology detection.
1292
1293 # Some NUMA nodes have memory ranges that span
1294 # other nodes. Even though a pfn is valid and
1295 # between a node's start and end pfns, it may not
1296 # reside on that node. See memmap_init_zone()
1297 # for details.
1298 config NODES_SPAN_OTHER_NODES
1299 def_bool y
1300 depends on X86_64_ACPI_NUMA
1301
1302 config NUMA_EMU
1303 bool "NUMA emulation"
1304 depends on NUMA
1305 ---help---
1306 Enable NUMA emulation. A flat machine will be split
1307 into virtual nodes when booted with "numa=fake=N", where N is the
1308 number of nodes. This is only useful for debugging.
1309
1310 config NODES_SHIFT
1311 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1312 range 1 10
1313 default "10" if MAXSMP
1314 default "6" if X86_64
1315 default "4" if X86_NUMAQ
1316 default "3"
1317 depends on NEED_MULTIPLE_NODES
1318 ---help---
1319 Specify the maximum number of NUMA Nodes available on the target
1320 system. Increases memory reserved to accommodate various tables.
1321
1322 config ARCH_HAVE_MEMORY_PRESENT
1323 def_bool y
1324 depends on X86_32 && DISCONTIGMEM
1325
1326 config NEED_NODE_MEMMAP_SIZE
1327 def_bool y
1328 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1329
1330 config ARCH_FLATMEM_ENABLE
1331 def_bool y
1332 depends on X86_32 && !NUMA
1333
1334 config ARCH_DISCONTIGMEM_ENABLE
1335 def_bool y
1336 depends on NUMA && X86_32
1337
1338 config ARCH_DISCONTIGMEM_DEFAULT
1339 def_bool y
1340 depends on NUMA && X86_32
1341
1342 config ARCH_SPARSEMEM_ENABLE
1343 def_bool y
1344 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1345 select SPARSEMEM_STATIC if X86_32
1346 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1347
1348 config ARCH_SPARSEMEM_DEFAULT
1349 def_bool y
1350 depends on X86_64
1351
1352 config ARCH_SELECT_MEMORY_MODEL
1353 def_bool y
1354 depends on ARCH_SPARSEMEM_ENABLE
1355
1356 config ARCH_MEMORY_PROBE
1357 bool "Enable sysfs memory/probe interface"
1358 depends on X86_64 && MEMORY_HOTPLUG
1359 help
1360 This option enables a sysfs memory/probe interface for testing.
1361 See Documentation/memory-hotplug.txt for more information.
1362 If you are unsure how to answer this question, answer N.
1363
1364 config ARCH_PROC_KCORE_TEXT
1365 def_bool y
1366 depends on X86_64 && PROC_KCORE
1367
1368 config ILLEGAL_POINTER_VALUE
1369 hex
1370 default 0 if X86_32
1371 default 0xdead000000000000 if X86_64
1372
1373 source "mm/Kconfig"
1374
1375 config HIGHPTE
1376 bool "Allocate 3rd-level pagetables from highmem"
1377 depends on HIGHMEM
1378 ---help---
1379 The VM uses one page table entry for each page of physical memory.
1380 For systems with a lot of RAM, this can be wasteful of precious
1381 low memory. Setting this option will put user-space page table
1382 entries in high memory.
1383
1384 config X86_CHECK_BIOS_CORRUPTION
1385 bool "Check for low memory corruption"
1386 ---help---
1387 Periodically check for memory corruption in low memory, which
1388 is suspected to be caused by BIOS. Even when enabled in the
1389 configuration, it is disabled at runtime. Enable it by
1390 setting "memory_corruption_check=1" on the kernel command
1391 line. By default it scans the low 64k of memory every 60
1392 seconds; see the memory_corruption_check_size and
1393 memory_corruption_check_period parameters in
1394 Documentation/kernel-parameters.txt to adjust this.
1395
1396 When enabled with the default parameters, this option has
1397 almost no overhead, as it reserves a relatively small amount
1398 of memory and scans it infrequently. It both detects corruption
1399 and prevents it from affecting the running system.
1400
1401 It is, however, intended as a diagnostic tool; if repeatable
1402 BIOS-originated corruption always affects the same memory,
1403 you can use memmap= to prevent the kernel from using that
1404 memory.
1405
1406 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1407 bool "Set the default setting of memory_corruption_check"
1408 depends on X86_CHECK_BIOS_CORRUPTION
1409 default y
1410 ---help---
1411 Set whether the default state of memory_corruption_check is
1412 on or off.
1413
1414 config X86_RESERVE_LOW
1415 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1416 default 64
1417 range 4 640
1418 ---help---
1419 Specify the amount of low memory to reserve for the BIOS.
1420
1421 The first page contains BIOS data structures that the kernel
1422 must not use, so that page must always be reserved.
1423
1424 By default we reserve the first 64K of physical RAM, as a
1425 number of BIOSes are known to corrupt that memory range
1426 during events such as suspend/resume or monitor cable
1427 insertion, so it must not be used by the kernel.
1428
1429 You can set this to 4 if you are absolutely sure that you
1430 trust the BIOS to get all its memory reservations and usages
1431 right. If you know your BIOS have problems beyond the
1432 default 64K area, you can set this to 640 to avoid using the
1433 entire low memory range.
1434
1435 If you have doubts about the BIOS (e.g. suspend/resume does
1436 not work or there's kernel crashes after certain hardware
1437 hotplug events) then you might want to enable
1438 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1439 typical corruption patterns.
1440
1441 Leave this to the default value of 64 if you are unsure.
1442
1443 config MATH_EMULATION
1444 bool
1445 prompt "Math emulation" if X86_32
1446 ---help---
1447 Linux can emulate a math coprocessor (used for floating point
1448 operations) if you don't have one. 486DX and Pentium processors have
1449 a math coprocessor built in, 486SX and 386 do not, unless you added
1450 a 487DX or 387, respectively. (The messages during boot time can
1451 give you some hints here ["man dmesg"].) Everyone needs either a
1452 coprocessor or this emulation.
1453
1454 If you don't have a math coprocessor, you need to say Y here; if you
1455 say Y here even though you have a coprocessor, the coprocessor will
1456 be used nevertheless. (This behavior can be changed with the kernel
1457 command line option "no387", which comes handy if your coprocessor
1458 is broken. Try "man bootparam" or see the documentation of your boot
1459 loader (lilo or loadlin) about how to pass options to the kernel at
1460 boot time.) This means that it is a good idea to say Y here if you
1461 intend to use this kernel on different machines.
1462
1463 More information about the internals of the Linux math coprocessor
1464 emulation can be found in <file:arch/x86/math-emu/README>.
1465
1466 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1467 kernel, it won't hurt.
1468
1469 config MTRR
1470 def_bool y
1471 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1472 ---help---
1473 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1474 the Memory Type Range Registers (MTRRs) may be used to control
1475 processor access to memory ranges. This is most useful if you have
1476 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1477 allows bus write transfers to be combined into a larger transfer
1478 before bursting over the PCI/AGP bus. This can increase performance
1479 of image write operations 2.5 times or more. Saying Y here creates a
1480 /proc/mtrr file which may be used to manipulate your processor's
1481 MTRRs. Typically the X server should use this.
1482
1483 This code has a reasonably generic interface so that similar
1484 control registers on other processors can be easily supported
1485 as well:
1486
1487 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1488 Registers (ARRs) which provide a similar functionality to MTRRs. For
1489 these, the ARRs are used to emulate the MTRRs.
1490 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1491 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1492 write-combining. All of these processors are supported by this code
1493 and it makes sense to say Y here if you have one of them.
1494
1495 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1496 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1497 can lead to all sorts of problems, so it's good to say Y here.
1498
1499 You can safely say Y even if your machine doesn't have MTRRs, you'll
1500 just add about 9 KB to your kernel.
1501
1502 See <file:Documentation/x86/mtrr.txt> for more information.
1503
1504 config MTRR_SANITIZER
1505 def_bool y
1506 prompt "MTRR cleanup support"
1507 depends on MTRR
1508 ---help---
1509 Convert MTRR layout from continuous to discrete, so X drivers can
1510 add writeback entries.
1511
1512 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1513 The largest mtrr entry size for a continuous block can be set with
1514 mtrr_chunk_size.
1515
1516 If unsure, say Y.
1517
1518 config MTRR_SANITIZER_ENABLE_DEFAULT
1519 int "MTRR cleanup enable value (0-1)"
1520 range 0 1
1521 default "0"
1522 depends on MTRR_SANITIZER
1523 ---help---
1524 Enable mtrr cleanup default value
1525
1526 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1527 int "MTRR cleanup spare reg num (0-7)"
1528 range 0 7
1529 default "1"
1530 depends on MTRR_SANITIZER
1531 ---help---
1532 mtrr cleanup spare entries default, it can be changed via
1533 mtrr_spare_reg_nr=N on the kernel command line.
1534
1535 config X86_PAT
1536 def_bool y
1537 prompt "x86 PAT support" if EXPERT
1538 depends on MTRR
1539 ---help---
1540 Use PAT attributes to setup page level cache control.
1541
1542 PATs are the modern equivalents of MTRRs and are much more
1543 flexible than MTRRs.
1544
1545 Say N here if you see bootup problems (boot crash, boot hang,
1546 spontaneous reboots) or a non-working video driver.
1547
1548 If unsure, say Y.
1549
1550 config ARCH_USES_PG_UNCACHED
1551 def_bool y
1552 depends on X86_PAT
1553
1554 config ARCH_RANDOM
1555 def_bool y
1556 prompt "x86 architectural random number generator" if EXPERT
1557 ---help---
1558 Enable the x86 architectural RDRAND instruction
1559 (Intel Bull Mountain technology) to generate random numbers.
1560 If supported, this is a high bandwidth, cryptographically
1561 secure hardware random number generator.
1562
1563 config X86_SMAP
1564 def_bool y
1565 prompt "Supervisor Mode Access Prevention" if EXPERT
1566 ---help---
1567 Supervisor Mode Access Prevention (SMAP) is a security
1568 feature in newer Intel processors. There is a small
1569 performance cost if this enabled and turned on; there is
1570 also a small increase in the kernel size if this is enabled.
1571
1572 If unsure, say Y.
1573
1574 config EFI
1575 bool "EFI runtime service support"
1576 depends on ACPI
1577 select UCS2_STRING
1578 ---help---
1579 This enables the kernel to use EFI runtime services that are
1580 available (such as the EFI variable services).
1581
1582 This option is only useful on systems that have EFI firmware.
1583 In addition, you should use the latest ELILO loader available
1584 at <http://elilo.sourceforge.net> in order to take advantage
1585 of EFI runtime services. However, even with this option, the
1586 resultant kernel should continue to boot on existing non-EFI
1587 platforms.
1588
1589 config EFI_STUB
1590 bool "EFI stub support"
1591 depends on EFI
1592 ---help---
1593 This kernel feature allows a bzImage to be loaded directly
1594 by EFI firmware without the use of a bootloader.
1595
1596 See Documentation/x86/efi-stub.txt for more information.
1597
1598 config SECCOMP
1599 def_bool y
1600 prompt "Enable seccomp to safely compute untrusted bytecode"
1601 ---help---
1602 This kernel feature is useful for number crunching applications
1603 that may need to compute untrusted bytecode during their
1604 execution. By using pipes or other transports made available to
1605 the process as file descriptors supporting the read/write
1606 syscalls, it's possible to isolate those applications in
1607 their own address space using seccomp. Once seccomp is
1608 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1609 and the task is only allowed to execute a few safe syscalls
1610 defined by each seccomp mode.
1611
1612 If unsure, say Y. Only embedded should say N here.
1613
1614 config CC_STACKPROTECTOR
1615 bool "Enable -fstack-protector buffer overflow detection"
1616 ---help---
1617 This option turns on the -fstack-protector GCC feature. This
1618 feature puts, at the beginning of functions, a canary value on
1619 the stack just before the return address, and validates
1620 the value just before actually returning. Stack based buffer
1621 overflows (that need to overwrite this return address) now also
1622 overwrite the canary, which gets detected and the attack is then
1623 neutralized via a kernel panic.
1624
1625 This feature requires gcc version 4.2 or above, or a distribution
1626 gcc with the feature backported. Older versions are automatically
1627 detected and for those versions, this configuration option is
1628 ignored. (and a warning is printed during bootup)
1629
1630 source kernel/Kconfig.hz
1631
1632 config KEXEC
1633 bool "kexec system call"
1634 ---help---
1635 kexec is a system call that implements the ability to shutdown your
1636 current kernel, and to start another kernel. It is like a reboot
1637 but it is independent of the system firmware. And like a reboot
1638 you can start any kernel with it, not just Linux.
1639
1640 The name comes from the similarity to the exec system call.
1641
1642 It is an ongoing process to be certain the hardware in a machine
1643 is properly shutdown, so do not be surprised if this code does not
1644 initially work for you. As of this writing the exact hardware
1645 interface is strongly in flux, so no good recommendation can be
1646 made.
1647
1648 config CRASH_DUMP
1649 bool "kernel crash dumps"
1650 depends on X86_64 || (X86_32 && HIGHMEM)
1651 ---help---
1652 Generate crash dump after being started by kexec.
1653 This should be normally only set in special crash dump kernels
1654 which are loaded in the main kernel with kexec-tools into
1655 a specially reserved region and then later executed after
1656 a crash by kdump/kexec. The crash dump kernel must be compiled
1657 to a memory address not used by the main kernel or BIOS using
1658 PHYSICAL_START, or it must be built as a relocatable image
1659 (CONFIG_RELOCATABLE=y).
1660 For more details see Documentation/kdump/kdump.txt
1661
1662 config KEXEC_JUMP
1663 bool "kexec jump"
1664 depends on KEXEC && HIBERNATION
1665 ---help---
1666 Jump between original kernel and kexeced kernel and invoke
1667 code in physical address mode via KEXEC
1668
1669 config PHYSICAL_START
1670 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1671 default "0x1000000"
1672 ---help---
1673 This gives the physical address where the kernel is loaded.
1674
1675 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1676 bzImage will decompress itself to above physical address and
1677 run from there. Otherwise, bzImage will run from the address where
1678 it has been loaded by the boot loader and will ignore above physical
1679 address.
1680
1681 In normal kdump cases one does not have to set/change this option
1682 as now bzImage can be compiled as a completely relocatable image
1683 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1684 address. This option is mainly useful for the folks who don't want
1685 to use a bzImage for capturing the crash dump and want to use a
1686 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1687 to be specifically compiled to run from a specific memory area
1688 (normally a reserved region) and this option comes handy.
1689
1690 So if you are using bzImage for capturing the crash dump,
1691 leave the value here unchanged to 0x1000000 and set
1692 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1693 for capturing the crash dump change this value to start of
1694 the reserved region. In other words, it can be set based on
1695 the "X" value as specified in the "crashkernel=YM@XM"
1696 command line boot parameter passed to the panic-ed
1697 kernel. Please take a look at Documentation/kdump/kdump.txt
1698 for more details about crash dumps.
1699
1700 Usage of bzImage for capturing the crash dump is recommended as
1701 one does not have to build two kernels. Same kernel can be used
1702 as production kernel and capture kernel. Above option should have
1703 gone away after relocatable bzImage support is introduced. But it
1704 is present because there are users out there who continue to use
1705 vmlinux for dump capture. This option should go away down the
1706 line.
1707
1708 Don't change this unless you know what you are doing.
1709
1710 config RELOCATABLE
1711 bool "Build a relocatable kernel"
1712 default y
1713 ---help---
1714 This builds a kernel image that retains relocation information
1715 so it can be loaded someplace besides the default 1MB.
1716 The relocations tend to make the kernel binary about 10% larger,
1717 but are discarded at runtime.
1718
1719 One use is for the kexec on panic case where the recovery kernel
1720 must live at a different physical address than the primary
1721 kernel.
1722
1723 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1724 it has been loaded at and the compile time physical address
1725 (CONFIG_PHYSICAL_START) is ignored.
1726
1727 # Relocation on x86-32 needs some additional build support
1728 config X86_NEED_RELOCS
1729 def_bool y
1730 depends on X86_32 && RELOCATABLE
1731
1732 config PHYSICAL_ALIGN
1733 hex "Alignment value to which kernel should be aligned"
1734 default "0x1000000"
1735 range 0x2000 0x1000000 if X86_32
1736 range 0x200000 0x1000000 if X86_64
1737 ---help---
1738 This value puts the alignment restrictions on physical address
1739 where kernel is loaded and run from. Kernel is compiled for an
1740 address which meets above alignment restriction.
1741
1742 If bootloader loads the kernel at a non-aligned address and
1743 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1744 address aligned to above value and run from there.
1745
1746 If bootloader loads the kernel at a non-aligned address and
1747 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1748 load address and decompress itself to the address it has been
1749 compiled for and run from there. The address for which kernel is
1750 compiled already meets above alignment restrictions. Hence the
1751 end result is that kernel runs from a physical address meeting
1752 above alignment restrictions.
1753
1754 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1755 this value must be a multiple of 0x200000.
1756
1757 Don't change this unless you know what you are doing.
1758
1759 config HOTPLUG_CPU
1760 bool "Support for hot-pluggable CPUs"
1761 depends on SMP
1762 ---help---
1763 Say Y here to allow turning CPUs off and on. CPUs can be
1764 controlled through /sys/devices/system/cpu.
1765 ( Note: power management support will enable this option
1766 automatically on SMP systems. )
1767 Say N if you want to disable CPU hotplug.
1768
1769 config BOOTPARAM_HOTPLUG_CPU0
1770 bool "Set default setting of cpu0_hotpluggable"
1771 default n
1772 depends on HOTPLUG_CPU
1773 ---help---
1774 Set whether default state of cpu0_hotpluggable is on or off.
1775
1776 Say Y here to enable CPU0 hotplug by default. If this switch
1777 is turned on, there is no need to give cpu0_hotplug kernel
1778 parameter and the CPU0 hotplug feature is enabled by default.
1779
1780 Please note: there are two known CPU0 dependencies if you want
1781 to enable the CPU0 hotplug feature either by this switch or by
1782 cpu0_hotplug kernel parameter.
1783
1784 First, resume from hibernate or suspend always starts from CPU0.
1785 So hibernate and suspend are prevented if CPU0 is offline.
1786
1787 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1788 offline if any interrupt can not migrate out of CPU0. There may
1789 be other CPU0 dependencies.
1790
1791 Please make sure the dependencies are under your control before
1792 you enable this feature.
1793
1794 Say N if you don't want to enable CPU0 hotplug feature by default.
1795 You still can enable the CPU0 hotplug feature at boot by kernel
1796 parameter cpu0_hotplug.
1797
1798 config DEBUG_HOTPLUG_CPU0
1799 def_bool n
1800 prompt "Debug CPU0 hotplug"
1801 depends on HOTPLUG_CPU
1802 ---help---
1803 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1804 soon as possible and boots up userspace with CPU0 offlined. User
1805 can online CPU0 back after boot time.
1806
1807 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1808 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1809 compilation or giving cpu0_hotplug kernel parameter at boot.
1810
1811 If unsure, say N.
1812
1813 config COMPAT_VDSO
1814 def_bool y
1815 prompt "Compat VDSO support"
1816 depends on X86_32 || IA32_EMULATION
1817 ---help---
1818 Map the 32-bit VDSO to the predictable old-style address too.
1819
1820 Say N here if you are running a sufficiently recent glibc
1821 version (2.3.3 or later), to remove the high-mapped
1822 VDSO mapping and to exclusively use the randomized VDSO.
1823
1824 If unsure, say Y.
1825
1826 config CMDLINE_BOOL
1827 bool "Built-in kernel command line"
1828 ---help---
1829 Allow for specifying boot arguments to the kernel at
1830 build time. On some systems (e.g. embedded ones), it is
1831 necessary or convenient to provide some or all of the
1832 kernel boot arguments with the kernel itself (that is,
1833 to not rely on the boot loader to provide them.)
1834
1835 To compile command line arguments into the kernel,
1836 set this option to 'Y', then fill in the
1837 the boot arguments in CONFIG_CMDLINE.
1838
1839 Systems with fully functional boot loaders (i.e. non-embedded)
1840 should leave this option set to 'N'.
1841
1842 config CMDLINE
1843 string "Built-in kernel command string"
1844 depends on CMDLINE_BOOL
1845 default ""
1846 ---help---
1847 Enter arguments here that should be compiled into the kernel
1848 image and used at boot time. If the boot loader provides a
1849 command line at boot time, it is appended to this string to
1850 form the full kernel command line, when the system boots.
1851
1852 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1853 change this behavior.
1854
1855 In most cases, the command line (whether built-in or provided
1856 by the boot loader) should specify the device for the root
1857 file system.
1858
1859 config CMDLINE_OVERRIDE
1860 bool "Built-in command line overrides boot loader arguments"
1861 depends on CMDLINE_BOOL
1862 ---help---
1863 Set this option to 'Y' to have the kernel ignore the boot loader
1864 command line, and use ONLY the built-in command line.
1865
1866 This is used to work around broken boot loaders. This should
1867 be set to 'N' under normal conditions.
1868
1869 endmenu
1870
1871 config ARCH_ENABLE_MEMORY_HOTPLUG
1872 def_bool y
1873 depends on X86_64 || (X86_32 && HIGHMEM)
1874
1875 config ARCH_ENABLE_MEMORY_HOTREMOVE
1876 def_bool y
1877 depends on MEMORY_HOTPLUG
1878
1879 config USE_PERCPU_NUMA_NODE_ID
1880 def_bool y
1881 depends on NUMA
1882
1883 menu "Power management and ACPI options"
1884
1885 config ARCH_HIBERNATION_HEADER
1886 def_bool y
1887 depends on X86_64 && HIBERNATION
1888
1889 source "kernel/power/Kconfig"
1890
1891 source "drivers/acpi/Kconfig"
1892
1893 source "drivers/sfi/Kconfig"
1894
1895 config X86_APM_BOOT
1896 def_bool y
1897 depends on APM
1898
1899 menuconfig APM
1900 tristate "APM (Advanced Power Management) BIOS support"
1901 depends on X86_32 && PM_SLEEP
1902 ---help---
1903 APM is a BIOS specification for saving power using several different
1904 techniques. This is mostly useful for battery powered laptops with
1905 APM compliant BIOSes. If you say Y here, the system time will be
1906 reset after a RESUME operation, the /proc/apm device will provide
1907 battery status information, and user-space programs will receive
1908 notification of APM "events" (e.g. battery status change).
1909
1910 If you select "Y" here, you can disable actual use of the APM
1911 BIOS by passing the "apm=off" option to the kernel at boot time.
1912
1913 Note that the APM support is almost completely disabled for
1914 machines with more than one CPU.
1915
1916 In order to use APM, you will need supporting software. For location
1917 and more information, read <file:Documentation/power/apm-acpi.txt>
1918 and the Battery Powered Linux mini-HOWTO, available from
1919 <http://www.tldp.org/docs.html#howto>.
1920
1921 This driver does not spin down disk drives (see the hdparm(8)
1922 manpage ("man 8 hdparm") for that), and it doesn't turn off
1923 VESA-compliant "green" monitors.
1924
1925 This driver does not support the TI 4000M TravelMate and the ACER
1926 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1927 desktop machines also don't have compliant BIOSes, and this driver
1928 may cause those machines to panic during the boot phase.
1929
1930 Generally, if you don't have a battery in your machine, there isn't
1931 much point in using this driver and you should say N. If you get
1932 random kernel OOPSes or reboots that don't seem to be related to
1933 anything, try disabling/enabling this option (or disabling/enabling
1934 APM in your BIOS).
1935
1936 Some other things you should try when experiencing seemingly random,
1937 "weird" problems:
1938
1939 1) make sure that you have enough swap space and that it is
1940 enabled.
1941 2) pass the "no-hlt" option to the kernel
1942 3) switch on floating point emulation in the kernel and pass
1943 the "no387" option to the kernel
1944 4) pass the "floppy=nodma" option to the kernel
1945 5) pass the "mem=4M" option to the kernel (thereby disabling
1946 all but the first 4 MB of RAM)
1947 6) make sure that the CPU is not over clocked.
1948 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1949 8) disable the cache from your BIOS settings
1950 9) install a fan for the video card or exchange video RAM
1951 10) install a better fan for the CPU
1952 11) exchange RAM chips
1953 12) exchange the motherboard.
1954
1955 To compile this driver as a module, choose M here: the
1956 module will be called apm.
1957
1958 if APM
1959
1960 config APM_IGNORE_USER_SUSPEND
1961 bool "Ignore USER SUSPEND"
1962 ---help---
1963 This option will ignore USER SUSPEND requests. On machines with a
1964 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1965 series notebooks, it is necessary to say Y because of a BIOS bug.
1966
1967 config APM_DO_ENABLE
1968 bool "Enable PM at boot time"
1969 ---help---
1970 Enable APM features at boot time. From page 36 of the APM BIOS
1971 specification: "When disabled, the APM BIOS does not automatically
1972 power manage devices, enter the Standby State, enter the Suspend
1973 State, or take power saving steps in response to CPU Idle calls."
1974 This driver will make CPU Idle calls when Linux is idle (unless this
1975 feature is turned off -- see "Do CPU IDLE calls", below). This
1976 should always save battery power, but more complicated APM features
1977 will be dependent on your BIOS implementation. You may need to turn
1978 this option off if your computer hangs at boot time when using APM
1979 support, or if it beeps continuously instead of suspending. Turn
1980 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1981 T400CDT. This is off by default since most machines do fine without
1982 this feature.
1983
1984 config APM_CPU_IDLE
1985 depends on CPU_IDLE
1986 bool "Make CPU Idle calls when idle"
1987 ---help---
1988 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1989 On some machines, this can activate improved power savings, such as
1990 a slowed CPU clock rate, when the machine is idle. These idle calls
1991 are made after the idle loop has run for some length of time (e.g.,
1992 333 mS). On some machines, this will cause a hang at boot time or
1993 whenever the CPU becomes idle. (On machines with more than one CPU,
1994 this option does nothing.)
1995
1996 config APM_DISPLAY_BLANK
1997 bool "Enable console blanking using APM"
1998 ---help---
1999 Enable console blanking using the APM. Some laptops can use this to
2000 turn off the LCD backlight when the screen blanker of the Linux
2001 virtual console blanks the screen. Note that this is only used by
2002 the virtual console screen blanker, and won't turn off the backlight
2003 when using the X Window system. This also doesn't have anything to
2004 do with your VESA-compliant power-saving monitor. Further, this
2005 option doesn't work for all laptops -- it might not turn off your
2006 backlight at all, or it might print a lot of errors to the console,
2007 especially if you are using gpm.
2008
2009 config APM_ALLOW_INTS
2010 bool "Allow interrupts during APM BIOS calls"
2011 ---help---
2012 Normally we disable external interrupts while we are making calls to
2013 the APM BIOS as a measure to lessen the effects of a badly behaving
2014 BIOS implementation. The BIOS should reenable interrupts if it
2015 needs to. Unfortunately, some BIOSes do not -- especially those in
2016 many of the newer IBM Thinkpads. If you experience hangs when you
2017 suspend, try setting this to Y. Otherwise, say N.
2018
2019 endif # APM
2020
2021 source "drivers/cpufreq/Kconfig"
2022
2023 source "drivers/cpuidle/Kconfig"
2024
2025 source "drivers/idle/Kconfig"
2026
2027 endmenu
2028
2029
2030 menu "Bus options (PCI etc.)"
2031
2032 config PCI
2033 bool "PCI support"
2034 default y
2035 ---help---
2036 Find out whether you have a PCI motherboard. PCI is the name of a
2037 bus system, i.e. the way the CPU talks to the other stuff inside
2038 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2039 VESA. If you have PCI, say Y, otherwise N.
2040
2041 choice
2042 prompt "PCI access mode"
2043 depends on X86_32 && PCI
2044 default PCI_GOANY
2045 ---help---
2046 On PCI systems, the BIOS can be used to detect the PCI devices and
2047 determine their configuration. However, some old PCI motherboards
2048 have BIOS bugs and may crash if this is done. Also, some embedded
2049 PCI-based systems don't have any BIOS at all. Linux can also try to
2050 detect the PCI hardware directly without using the BIOS.
2051
2052 With this option, you can specify how Linux should detect the
2053 PCI devices. If you choose "BIOS", the BIOS will be used,
2054 if you choose "Direct", the BIOS won't be used, and if you
2055 choose "MMConfig", then PCI Express MMCONFIG will be used.
2056 If you choose "Any", the kernel will try MMCONFIG, then the
2057 direct access method and falls back to the BIOS if that doesn't
2058 work. If unsure, go with the default, which is "Any".
2059
2060 config PCI_GOBIOS
2061 bool "BIOS"
2062
2063 config PCI_GOMMCONFIG
2064 bool "MMConfig"
2065
2066 config PCI_GODIRECT
2067 bool "Direct"
2068
2069 config PCI_GOOLPC
2070 bool "OLPC XO-1"
2071 depends on OLPC
2072
2073 config PCI_GOANY
2074 bool "Any"
2075
2076 endchoice
2077
2078 config PCI_BIOS
2079 def_bool y
2080 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2081
2082 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2083 config PCI_DIRECT
2084 def_bool y
2085 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2086
2087 config PCI_MMCONFIG
2088 def_bool y
2089 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2090
2091 config PCI_OLPC
2092 def_bool y
2093 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2094
2095 config PCI_XEN
2096 def_bool y
2097 depends on PCI && XEN
2098 select SWIOTLB_XEN
2099
2100 config PCI_DOMAINS
2101 def_bool y
2102 depends on PCI
2103
2104 config PCI_MMCONFIG
2105 bool "Support mmconfig PCI config space access"
2106 depends on X86_64 && PCI && ACPI
2107
2108 config PCI_CNB20LE_QUIRK
2109 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2110 depends on PCI
2111 help
2112 Read the PCI windows out of the CNB20LE host bridge. This allows
2113 PCI hotplug to work on systems with the CNB20LE chipset which do
2114 not have ACPI.
2115
2116 There's no public spec for this chipset, and this functionality
2117 is known to be incomplete.
2118
2119 You should say N unless you know you need this.
2120
2121 source "drivers/pci/pcie/Kconfig"
2122
2123 source "drivers/pci/Kconfig"
2124
2125 # x86_64 have no ISA slots, but can have ISA-style DMA.
2126 config ISA_DMA_API
2127 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2128 default y
2129 help
2130 Enables ISA-style DMA support for devices requiring such controllers.
2131 If unsure, say Y.
2132
2133 if X86_32
2134
2135 config ISA
2136 bool "ISA support"
2137 ---help---
2138 Find out whether you have ISA slots on your motherboard. ISA is the
2139 name of a bus system, i.e. the way the CPU talks to the other stuff
2140 inside your box. Other bus systems are PCI, EISA, MicroChannel
2141 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2142 newer boards don't support it. If you have ISA, say Y, otherwise N.
2143
2144 config EISA
2145 bool "EISA support"
2146 depends on ISA
2147 ---help---
2148 The Extended Industry Standard Architecture (EISA) bus was
2149 developed as an open alternative to the IBM MicroChannel bus.
2150
2151 The EISA bus provided some of the features of the IBM MicroChannel
2152 bus while maintaining backward compatibility with cards made for
2153 the older ISA bus. The EISA bus saw limited use between 1988 and
2154 1995 when it was made obsolete by the PCI bus.
2155
2156 Say Y here if you are building a kernel for an EISA-based machine.
2157
2158 Otherwise, say N.
2159
2160 source "drivers/eisa/Kconfig"
2161
2162 config SCx200
2163 tristate "NatSemi SCx200 support"
2164 ---help---
2165 This provides basic support for National Semiconductor's
2166 (now AMD's) Geode processors. The driver probes for the
2167 PCI-IDs of several on-chip devices, so its a good dependency
2168 for other scx200_* drivers.
2169
2170 If compiled as a module, the driver is named scx200.
2171
2172 config SCx200HR_TIMER
2173 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2174 depends on SCx200
2175 default y
2176 ---help---
2177 This driver provides a clocksource built upon the on-chip
2178 27MHz high-resolution timer. Its also a workaround for
2179 NSC Geode SC-1100's buggy TSC, which loses time when the
2180 processor goes idle (as is done by the scheduler). The
2181 other workaround is idle=poll boot option.
2182
2183 config OLPC
2184 bool "One Laptop Per Child support"
2185 depends on !X86_PAE
2186 select GPIOLIB
2187 select OF
2188 select OF_PROMTREE
2189 select IRQ_DOMAIN
2190 ---help---
2191 Add support for detecting the unique features of the OLPC
2192 XO hardware.
2193
2194 config OLPC_XO1_PM
2195 bool "OLPC XO-1 Power Management"
2196 depends on OLPC && MFD_CS5535 && PM_SLEEP
2197 select MFD_CORE
2198 ---help---
2199 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2200
2201 config OLPC_XO1_RTC
2202 bool "OLPC XO-1 Real Time Clock"
2203 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2204 ---help---
2205 Add support for the XO-1 real time clock, which can be used as a
2206 programmable wakeup source.
2207
2208 config OLPC_XO1_SCI
2209 bool "OLPC XO-1 SCI extras"
2210 depends on OLPC && OLPC_XO1_PM
2211 depends on INPUT=y
2212 select POWER_SUPPLY
2213 select GPIO_CS5535
2214 select MFD_CORE
2215 ---help---
2216 Add support for SCI-based features of the OLPC XO-1 laptop:
2217 - EC-driven system wakeups
2218 - Power button
2219 - Ebook switch
2220 - Lid switch
2221 - AC adapter status updates
2222 - Battery status updates
2223
2224 config OLPC_XO15_SCI
2225 bool "OLPC XO-1.5 SCI extras"
2226 depends on OLPC && ACPI
2227 select POWER_SUPPLY
2228 ---help---
2229 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2230 - EC-driven system wakeups
2231 - AC adapter status updates
2232 - Battery status updates
2233
2234 config ALIX
2235 bool "PCEngines ALIX System Support (LED setup)"
2236 select GPIOLIB
2237 ---help---
2238 This option enables system support for the PCEngines ALIX.
2239 At present this just sets up LEDs for GPIO control on
2240 ALIX2/3/6 boards. However, other system specific setup should
2241 get added here.
2242
2243 Note: You must still enable the drivers for GPIO and LED support
2244 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2245
2246 Note: You have to set alix.force=1 for boards with Award BIOS.
2247
2248 config NET5501
2249 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2250 select GPIOLIB
2251 ---help---
2252 This option enables system support for the Soekris Engineering net5501.
2253
2254 config GEOS
2255 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2256 select GPIOLIB
2257 depends on DMI
2258 ---help---
2259 This option enables system support for the Traverse Technologies GEOS.
2260
2261 config TS5500
2262 bool "Technologic Systems TS-5500 platform support"
2263 depends on MELAN
2264 select CHECK_SIGNATURE
2265 select NEW_LEDS
2266 select LEDS_CLASS
2267 ---help---
2268 This option enables system support for the Technologic Systems TS-5500.
2269
2270 endif # X86_32
2271
2272 config AMD_NB
2273 def_bool y
2274 depends on CPU_SUP_AMD && PCI
2275
2276 source "drivers/pcmcia/Kconfig"
2277
2278 source "drivers/pci/hotplug/Kconfig"
2279
2280 config RAPIDIO
2281 tristate "RapidIO support"
2282 depends on PCI
2283 default n
2284 help
2285 If enabled this option will include drivers and the core
2286 infrastructure code to support RapidIO interconnect devices.
2287
2288 source "drivers/rapidio/Kconfig"
2289
2290 config X86_SYSFB
2291 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2292 help
2293 Firmwares often provide initial graphics framebuffers so the BIOS,
2294 bootloader or kernel can show basic video-output during boot for
2295 user-guidance and debugging. Historically, x86 used the VESA BIOS
2296 Extensions and EFI-framebuffers for this, which are mostly limited
2297 to x86.
2298 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2299 framebuffers so the new generic system-framebuffer drivers can be
2300 used on x86. If the framebuffer is not compatible with the generic
2301 modes, it is adverticed as fallback platform framebuffer so legacy
2302 drivers like efifb, vesafb and uvesafb can pick it up.
2303 If this option is not selected, all system framebuffers are always
2304 marked as fallback platform framebuffers as usual.
2305
2306 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2307 not be able to pick up generic system framebuffers if this option
2308 is selected. You are highly encouraged to enable simplefb as
2309 replacement if you select this option. simplefb can correctly deal
2310 with generic system framebuffers. But you should still keep vesafb
2311 and others enabled as fallback if a system framebuffer is
2312 incompatible with simplefb.
2313
2314 If unsure, say Y.
2315
2316 endmenu
2317
2318
2319 menu "Executable file formats / Emulations"
2320
2321 source "fs/Kconfig.binfmt"
2322
2323 config IA32_EMULATION
2324 bool "IA32 Emulation"
2325 depends on X86_64
2326 select BINFMT_ELF
2327 select COMPAT_BINFMT_ELF
2328 select HAVE_UID16
2329 ---help---
2330 Include code to run legacy 32-bit programs under a
2331 64-bit kernel. You should likely turn this on, unless you're
2332 100% sure that you don't have any 32-bit programs left.
2333
2334 config IA32_AOUT
2335 tristate "IA32 a.out support"
2336 depends on IA32_EMULATION
2337 ---help---
2338 Support old a.out binaries in the 32bit emulation.
2339
2340 config X86_X32
2341 bool "x32 ABI for 64-bit mode"
2342 depends on X86_64 && IA32_EMULATION
2343 ---help---
2344 Include code to run binaries for the x32 native 32-bit ABI
2345 for 64-bit processors. An x32 process gets access to the
2346 full 64-bit register file and wide data path while leaving
2347 pointers at 32 bits for smaller memory footprint.
2348
2349 You will need a recent binutils (2.22 or later) with
2350 elf32_x86_64 support enabled to compile a kernel with this
2351 option set.
2352
2353 config COMPAT
2354 def_bool y
2355 depends on IA32_EMULATION || X86_X32
2356 select ARCH_WANT_OLD_COMPAT_IPC
2357
2358 if COMPAT
2359 config COMPAT_FOR_U64_ALIGNMENT
2360 def_bool y
2361
2362 config SYSVIPC_COMPAT
2363 def_bool y
2364 depends on SYSVIPC
2365
2366 config KEYS_COMPAT
2367 def_bool y
2368 depends on KEYS
2369 endif
2370
2371 endmenu
2372
2373
2374 config HAVE_ATOMIC_IOMAP
2375 def_bool y
2376 depends on X86_32
2377
2378 config X86_DEV_DMA_OPS
2379 bool
2380 depends on X86_64 || STA2X11
2381
2382 config X86_DMA_REMAP
2383 bool
2384 depends on STA2X11
2385
2386 source "net/Kconfig"
2387
2388 source "drivers/Kconfig"
2389
2390 source "drivers/firmware/Kconfig"
2391
2392 source "fs/Kconfig"
2393
2394 source "arch/x86/Kconfig.debug"
2395
2396 source "security/Kconfig"
2397
2398 source "crypto/Kconfig"
2399
2400 source "arch/x86/kvm/Kconfig"
2401
2402 source "lib/Kconfig"
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