timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
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
20 ### Arch settings
21 config X86
22 def_bool y
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IDE
26 select HAVE_OPROFILE
27 select HAVE_PCSPKR_PLATFORM
28 select HAVE_PERF_EVENTS
29 select HAVE_IRQ_WORK
30 select HAVE_IOREMAP_PROT
31 select HAVE_KPROBES
32 select HAVE_MEMBLOCK
33 select HAVE_MEMBLOCK_NODE_MAP
34 select ARCH_DISCARD_MEMBLOCK
35 select ARCH_WANT_OPTIONAL_GPIOLIB
36 select ARCH_WANT_FRAME_POINTERS
37 select HAVE_DMA_ATTRS
38 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
39 select HAVE_KRETPROBES
40 select HAVE_OPTPROBES
41 select HAVE_FTRACE_MCOUNT_RECORD
42 select HAVE_FENTRY if X86_64
43 select HAVE_C_RECORDMCOUNT
44 select HAVE_DYNAMIC_FTRACE
45 select HAVE_FUNCTION_TRACER
46 select HAVE_FUNCTION_GRAPH_TRACER
47 select HAVE_FUNCTION_GRAPH_FP_TEST
48 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
49 select HAVE_SYSCALL_TRACEPOINTS
50 select SYSCTL_EXCEPTION_TRACE
51 select HAVE_KVM
52 select HAVE_ARCH_KGDB
53 select HAVE_ARCH_TRACEHOOK
54 select HAVE_GENERIC_DMA_COHERENT if X86_32
55 select HAVE_EFFICIENT_UNALIGNED_ACCESS
56 select USER_STACKTRACE_SUPPORT
57 select HAVE_REGS_AND_STACK_ACCESS_API
58 select HAVE_DMA_API_DEBUG
59 select HAVE_KERNEL_GZIP
60 select HAVE_KERNEL_BZIP2
61 select HAVE_KERNEL_LZMA
62 select HAVE_KERNEL_XZ
63 select HAVE_KERNEL_LZO
64 select HAVE_HW_BREAKPOINT
65 select HAVE_MIXED_BREAKPOINTS_REGS
66 select PERF_EVENTS
67 select HAVE_PERF_EVENTS_NMI
68 select HAVE_PERF_REGS
69 select HAVE_PERF_USER_STACK_DUMP
70 select HAVE_DEBUG_KMEMLEAK
71 select ANON_INODES
72 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
73 select HAVE_CMPXCHG_LOCAL if !M386
74 select HAVE_CMPXCHG_DOUBLE
75 select HAVE_ARCH_KMEMCHECK
76 select HAVE_USER_RETURN_NOTIFIER
77 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
78 select HAVE_ARCH_JUMP_LABEL
79 select HAVE_TEXT_POKE_SMP
80 select HAVE_GENERIC_HARDIRQS
81 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
82 select SPARSE_IRQ
83 select GENERIC_FIND_FIRST_BIT
84 select GENERIC_IRQ_PROBE
85 select GENERIC_PENDING_IRQ if SMP
86 select GENERIC_IRQ_SHOW
87 select GENERIC_CLOCKEVENTS_MIN_ADJUST
88 select IRQ_FORCED_THREADING
89 select USE_GENERIC_SMP_HELPERS if SMP
90 select HAVE_BPF_JIT if X86_64
91 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
92 select CLKEVT_I8253
93 select ARCH_HAVE_NMI_SAFE_CMPXCHG
94 select GENERIC_IOMAP
95 select DCACHE_WORD_ACCESS
96 select GENERIC_SMP_IDLE_THREAD
97 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
98 select HAVE_ARCH_SECCOMP_FILTER
99 select BUILDTIME_EXTABLE_SORT
100 select GENERIC_CMOS_UPDATE
101 select CLOCKSOURCE_WATCHDOG
102 select GENERIC_CLOCKEVENTS
103 select ARCH_CLOCKSOURCE_DATA if X86_64
104 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
105 select GENERIC_TIME_VSYSCALL if X86_64
106 select KTIME_SCALAR if X86_32
107 select GENERIC_STRNCPY_FROM_USER
108 select GENERIC_STRNLEN_USER
109 select HAVE_RCU_USER_QS if X86_64
110 select HAVE_IRQ_TIME_ACCOUNTING
111 select ALWAYS_USE_PERSISTENT_CLOCK
112 select GENERIC_KERNEL_THREAD
113 select GENERIC_KERNEL_EXECVE
114 select MODULES_USE_ELF_REL if X86_32
115 select MODULES_USE_ELF_RELA if X86_64
116
117 config INSTRUCTION_DECODER
118 def_bool y
119 depends on KPROBES || PERF_EVENTS || UPROBES
120
121 config OUTPUT_FORMAT
122 string
123 default "elf32-i386" if X86_32
124 default "elf64-x86-64" if X86_64
125
126 config ARCH_DEFCONFIG
127 string
128 default "arch/x86/configs/i386_defconfig" if X86_32
129 default "arch/x86/configs/x86_64_defconfig" if X86_64
130
131 config LOCKDEP_SUPPORT
132 def_bool y
133
134 config STACKTRACE_SUPPORT
135 def_bool y
136
137 config HAVE_LATENCYTOP_SUPPORT
138 def_bool y
139
140 config MMU
141 def_bool y
142
143 config SBUS
144 bool
145
146 config NEED_DMA_MAP_STATE
147 def_bool y
148 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
149
150 config NEED_SG_DMA_LENGTH
151 def_bool y
152
153 config GENERIC_ISA_DMA
154 def_bool y
155 depends on ISA_DMA_API
156
157 config GENERIC_BUG
158 def_bool y
159 depends on BUG
160 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
161
162 config GENERIC_BUG_RELATIVE_POINTERS
163 bool
164
165 config GENERIC_HWEIGHT
166 def_bool y
167
168 config GENERIC_GPIO
169 bool
170
171 config ARCH_MAY_HAVE_PC_FDC
172 def_bool y
173 depends on ISA_DMA_API
174
175 config RWSEM_GENERIC_SPINLOCK
176 def_bool y
177 depends on !X86_XADD
178
179 config RWSEM_XCHGADD_ALGORITHM
180 def_bool y
181 depends on X86_XADD
182
183 config GENERIC_CALIBRATE_DELAY
184 def_bool y
185
186 config ARCH_HAS_CPU_RELAX
187 def_bool y
188
189 config ARCH_HAS_DEFAULT_IDLE
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 ZONE_DMA32
214 bool
215 default X86_64
216
217 config AUDIT_ARCH
218 bool
219 default X86_64
220
221 config ARCH_SUPPORTS_OPTIMIZED_INLINING
222 def_bool y
223
224 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
225 def_bool y
226
227 config HAVE_INTEL_TXT
228 def_bool y
229 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
230
231 config X86_32_SMP
232 def_bool y
233 depends on X86_32 && SMP
234
235 config X86_64_SMP
236 def_bool y
237 depends on X86_64 && SMP
238
239 config X86_HT
240 def_bool y
241 depends on SMP
242
243 config X86_32_LAZY_GS
244 def_bool y
245 depends on X86_32 && !CC_STACKPROTECTOR
246
247 config ARCH_HWEIGHT_CFLAGS
248 string
249 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
250 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
251
252 config ARCH_CPU_PROBE_RELEASE
253 def_bool y
254 depends on HOTPLUG_CPU
255
256 config ARCH_SUPPORTS_UPROBES
257 def_bool y
258
259 source "init/Kconfig"
260 source "kernel/Kconfig.freezer"
261
262 menu "Processor type and features"
263
264 config ZONE_DMA
265 bool "DMA memory allocation support" if EXPERT
266 default y
267 help
268 DMA memory allocation support allows devices with less than 32-bit
269 addressing to allocate within the first 16MB of address space.
270 Disable if no such devices will be used.
271
272 If unsure, say Y.
273
274 config SMP
275 bool "Symmetric multi-processing support"
276 ---help---
277 This enables support for systems with more than one CPU. If you have
278 a system with only one CPU, like most personal computers, say N. If
279 you have a system with more than one CPU, say Y.
280
281 If you say N here, the kernel will run on single and multiprocessor
282 machines, but will use only one CPU of a multiprocessor machine. If
283 you say Y here, the kernel will run on many, but not all,
284 singleprocessor machines. On a singleprocessor machine, the kernel
285 will run faster if you say N here.
286
287 Note that if you say Y here and choose architecture "586" or
288 "Pentium" under "Processor family", the kernel will not work on 486
289 architectures. Similarly, multiprocessor kernels for the "PPro"
290 architecture may not work on all Pentium based boards.
291
292 People using multiprocessor machines who say Y here should also say
293 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
294 Management" code will be disabled if you say Y here.
295
296 See also <file:Documentation/x86/i386/IO-APIC.txt>,
297 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
298 <http://www.tldp.org/docs.html#howto>.
299
300 If you don't know what to do here, say N.
301
302 config X86_X2APIC
303 bool "Support x2apic"
304 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
305 ---help---
306 This enables x2apic support on CPUs that have this feature.
307
308 This allows 32-bit apic IDs (so it can support very large systems),
309 and accesses the local apic via MSRs not via mmio.
310
311 If you don't know what to do here, say N.
312
313 config X86_MPPARSE
314 bool "Enable MPS table" if ACPI
315 default y
316 depends on X86_LOCAL_APIC
317 ---help---
318 For old smp systems that do not have proper acpi support. Newer systems
319 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
320
321 config X86_BIGSMP
322 bool "Support for big SMP systems with more than 8 CPUs"
323 depends on X86_32 && SMP
324 ---help---
325 This option is needed for the systems that have more than 8 CPUs
326
327 if X86_32
328 config X86_EXTENDED_PLATFORM
329 bool "Support for extended (non-PC) x86 platforms"
330 default y
331 ---help---
332 If you disable this option then the kernel will only support
333 standard PC platforms. (which covers the vast majority of
334 systems out there.)
335
336 If you enable this option then you'll be able to select support
337 for the following (non-PC) 32 bit x86 platforms:
338 AMD Elan
339 NUMAQ (IBM/Sequent)
340 RDC R-321x SoC
341 SGI 320/540 (Visual Workstation)
342 STA2X11-based (e.g. Northville)
343 Summit/EXA (IBM x440)
344 Unisys ES7000 IA32 series
345 Moorestown MID devices
346
347 If you have one of these systems, or if you want to build a
348 generic distribution kernel, say Y here - otherwise say N.
349 endif
350
351 if X86_64
352 config X86_EXTENDED_PLATFORM
353 bool "Support for extended (non-PC) x86 platforms"
354 default y
355 ---help---
356 If you disable this option then the kernel will only support
357 standard PC platforms. (which covers the vast majority of
358 systems out there.)
359
360 If you enable this option then you'll be able to select support
361 for the following (non-PC) 64 bit x86 platforms:
362 Numascale NumaChip
363 ScaleMP vSMP
364 SGI Ultraviolet
365
366 If you have one of these systems, or if you want to build a
367 generic distribution kernel, say Y here - otherwise say N.
368 endif
369 # This is an alphabetically sorted list of 64 bit extended platforms
370 # Please maintain the alphabetic order if and when there are additions
371 config X86_NUMACHIP
372 bool "Numascale NumaChip"
373 depends on X86_64
374 depends on X86_EXTENDED_PLATFORM
375 depends on NUMA
376 depends on SMP
377 depends on X86_X2APIC
378 ---help---
379 Adds support for Numascale NumaChip large-SMP systems. Needed to
380 enable more than ~168 cores.
381 If you don't have one of these, you should say N here.
382
383 config X86_VSMP
384 bool "ScaleMP vSMP"
385 select PARAVIRT_GUEST
386 select PARAVIRT
387 depends on X86_64 && PCI
388 depends on X86_EXTENDED_PLATFORM
389 depends on SMP
390 ---help---
391 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
392 supposed to run on these EM64T-based machines. Only choose this option
393 if you have one of these machines.
394
395 config X86_UV
396 bool "SGI Ultraviolet"
397 depends on X86_64
398 depends on X86_EXTENDED_PLATFORM
399 depends on NUMA
400 depends on X86_X2APIC
401 ---help---
402 This option is needed in order to support SGI Ultraviolet systems.
403 If you don't have one of these, you should say N here.
404
405 # Following is an alphabetically sorted list of 32 bit extended platforms
406 # Please maintain the alphabetic order if and when there are additions
407
408 config X86_INTEL_CE
409 bool "CE4100 TV platform"
410 depends on PCI
411 depends on PCI_GODIRECT
412 depends on X86_32
413 depends on X86_EXTENDED_PLATFORM
414 select X86_REBOOTFIXUPS
415 select OF
416 select OF_EARLY_FLATTREE
417 select IRQ_DOMAIN
418 ---help---
419 Select for the Intel CE media processor (CE4100) SOC.
420 This option compiles in support for the CE4100 SOC for settop
421 boxes and media devices.
422
423 config X86_WANT_INTEL_MID
424 bool "Intel MID platform support"
425 depends on X86_32
426 depends on X86_EXTENDED_PLATFORM
427 ---help---
428 Select to build a kernel capable of supporting Intel MID platform
429 systems which do not have the PCI legacy interfaces (Moorestown,
430 Medfield). If you are building for a PC class system say N here.
431
432 if X86_WANT_INTEL_MID
433
434 config X86_INTEL_MID
435 bool
436
437 config X86_MDFLD
438 bool "Medfield MID platform"
439 depends on PCI
440 depends on PCI_GOANY
441 depends on X86_IO_APIC
442 select X86_INTEL_MID
443 select SFI
444 select DW_APB_TIMER
445 select APB_TIMER
446 select I2C
447 select SPI
448 select INTEL_SCU_IPC
449 select X86_PLATFORM_DEVICES
450 select MFD_INTEL_MSIC
451 ---help---
452 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
453 Internet Device(MID) platform.
454 Unlike standard x86 PCs, Medfield does not have many legacy devices
455 nor standard legacy replacement devices/features. e.g. Medfield does
456 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
457
458 endif
459
460 config X86_RDC321X
461 bool "RDC R-321x SoC"
462 depends on X86_32
463 depends on X86_EXTENDED_PLATFORM
464 select M486
465 select X86_REBOOTFIXUPS
466 ---help---
467 This option is needed for RDC R-321x system-on-chip, also known
468 as R-8610-(G).
469 If you don't have one of these chips, you should say N here.
470
471 config X86_32_NON_STANDARD
472 bool "Support non-standard 32-bit SMP architectures"
473 depends on X86_32 && SMP
474 depends on X86_EXTENDED_PLATFORM
475 ---help---
476 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
477 STA2X11, default subarchitectures. It is intended for a generic
478 binary kernel. If you select them all, kernel will probe it
479 one by one and will fallback to default.
480
481 # Alphabetically sorted list of Non standard 32 bit platforms
482
483 config X86_NUMAQ
484 bool "NUMAQ (IBM/Sequent)"
485 depends on X86_32_NON_STANDARD
486 depends on PCI
487 select NUMA
488 select X86_MPPARSE
489 ---help---
490 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
491 NUMA multiquad box. This changes the way that processors are
492 bootstrapped, and uses Clustered Logical APIC addressing mode instead
493 of Flat Logical. You will need a new lynxer.elf file to flash your
494 firmware with - send email to <Martin.Bligh@us.ibm.com>.
495
496 config X86_SUPPORTS_MEMORY_FAILURE
497 def_bool y
498 # MCE code calls memory_failure():
499 depends on X86_MCE
500 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
501 depends on !X86_NUMAQ
502 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
503 depends on X86_64 || !SPARSEMEM
504 select ARCH_SUPPORTS_MEMORY_FAILURE
505
506 config X86_VISWS
507 bool "SGI 320/540 (Visual Workstation)"
508 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
509 depends on X86_32_NON_STANDARD
510 ---help---
511 The SGI Visual Workstation series is an IA32-based workstation
512 based on SGI systems chips with some legacy PC hardware attached.
513
514 Say Y here to create a kernel to run on the SGI 320 or 540.
515
516 A kernel compiled for the Visual Workstation will run on general
517 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
518
519 config STA2X11
520 bool "STA2X11 Companion Chip Support"
521 depends on X86_32_NON_STANDARD && PCI
522 select X86_DEV_DMA_OPS
523 select X86_DMA_REMAP
524 select SWIOTLB
525 select MFD_STA2X11
526 select ARCH_REQUIRE_GPIOLIB
527 default n
528 ---help---
529 This adds support for boards based on the STA2X11 IO-Hub,
530 a.k.a. "ConneXt". The chip is used in place of the standard
531 PC chipset, so all "standard" peripherals are missing. If this
532 option is selected the kernel will still be able to boot on
533 standard PC machines.
534
535 config X86_SUMMIT
536 bool "Summit/EXA (IBM x440)"
537 depends on X86_32_NON_STANDARD
538 ---help---
539 This option is needed for IBM systems that use the Summit/EXA chipset.
540 In particular, it is needed for the x440.
541
542 config X86_ES7000
543 bool "Unisys ES7000 IA32 series"
544 depends on X86_32_NON_STANDARD && X86_BIGSMP
545 ---help---
546 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
547 supposed to run on an IA32-based Unisys ES7000 system.
548
549 config X86_32_IRIS
550 tristate "Eurobraille/Iris poweroff module"
551 depends on X86_32
552 ---help---
553 The Iris machines from EuroBraille do not have APM or ACPI support
554 to shut themselves down properly. A special I/O sequence is
555 needed to do so, which is what this module does at
556 kernel shutdown.
557
558 This is only for Iris machines from EuroBraille.
559
560 If unused, say N.
561
562 config SCHED_OMIT_FRAME_POINTER
563 def_bool y
564 prompt "Single-depth WCHAN output"
565 depends on X86
566 ---help---
567 Calculate simpler /proc/<PID>/wchan values. If this option
568 is disabled then wchan values will recurse back to the
569 caller function. This provides more accurate wchan values,
570 at the expense of slightly more scheduling overhead.
571
572 If in doubt, say "Y".
573
574 menuconfig PARAVIRT_GUEST
575 bool "Paravirtualized guest support"
576 ---help---
577 Say Y here to get to see options related to running Linux under
578 various hypervisors. This option alone does not add any kernel code.
579
580 If you say N, all options in this submenu will be skipped and disabled.
581
582 if PARAVIRT_GUEST
583
584 config PARAVIRT_TIME_ACCOUNTING
585 bool "Paravirtual steal time accounting"
586 select PARAVIRT
587 default n
588 ---help---
589 Select this option to enable fine granularity task steal time
590 accounting. Time spent executing other tasks in parallel with
591 the current vCPU is discounted from the vCPU power. To account for
592 that, there can be a small performance impact.
593
594 If in doubt, say N here.
595
596 source "arch/x86/xen/Kconfig"
597
598 config KVM_GUEST
599 bool "KVM Guest support (including kvmclock)"
600 select PARAVIRT
601 select PARAVIRT
602 select PARAVIRT_CLOCK
603 default y if PARAVIRT_GUEST
604 ---help---
605 This option enables various optimizations for running under the KVM
606 hypervisor. It includes a paravirtualized clock, so that instead
607 of relying on a PIT (or probably other) emulation by the
608 underlying device model, the host provides the guest with
609 timing infrastructure such as time of day, and system time
610
611 source "arch/x86/lguest/Kconfig"
612
613 config PARAVIRT
614 bool "Enable paravirtualization code"
615 ---help---
616 This changes the kernel so it can modify itself when it is run
617 under a hypervisor, potentially improving performance significantly
618 over full virtualization. However, when run without a hypervisor
619 the kernel is theoretically slower and slightly larger.
620
621 config PARAVIRT_SPINLOCKS
622 bool "Paravirtualization layer for spinlocks"
623 depends on PARAVIRT && SMP && EXPERIMENTAL
624 ---help---
625 Paravirtualized spinlocks allow a pvops backend to replace the
626 spinlock implementation with something virtualization-friendly
627 (for example, block the virtual CPU rather than spinning).
628
629 Unfortunately the downside is an up to 5% performance hit on
630 native kernels, with various workloads.
631
632 If you are unsure how to answer this question, answer N.
633
634 config PARAVIRT_CLOCK
635 bool
636
637 endif
638
639 config PARAVIRT_DEBUG
640 bool "paravirt-ops debugging"
641 depends on PARAVIRT && DEBUG_KERNEL
642 ---help---
643 Enable to debug paravirt_ops internals. Specifically, BUG if
644 a paravirt_op is missing when it is called.
645
646 config NO_BOOTMEM
647 def_bool y
648
649 config MEMTEST
650 bool "Memtest"
651 ---help---
652 This option adds a kernel parameter 'memtest', which allows memtest
653 to be set.
654 memtest=0, mean disabled; -- default
655 memtest=1, mean do 1 test pattern;
656 ...
657 memtest=4, mean do 4 test patterns.
658 If you are unsure how to answer this question, answer N.
659
660 config X86_SUMMIT_NUMA
661 def_bool y
662 depends on X86_32 && NUMA && X86_32_NON_STANDARD
663
664 config X86_CYCLONE_TIMER
665 def_bool y
666 depends on X86_SUMMIT
667
668 source "arch/x86/Kconfig.cpu"
669
670 config HPET_TIMER
671 def_bool X86_64
672 prompt "HPET Timer Support" if X86_32
673 ---help---
674 Use the IA-PC HPET (High Precision Event Timer) to manage
675 time in preference to the PIT and RTC, if a HPET is
676 present.
677 HPET is the next generation timer replacing legacy 8254s.
678 The HPET provides a stable time base on SMP
679 systems, unlike the TSC, but it is more expensive to access,
680 as it is off-chip. You can find the HPET spec at
681 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
682
683 You can safely choose Y here. However, HPET will only be
684 activated if the platform and the BIOS support this feature.
685 Otherwise the 8254 will be used for timing services.
686
687 Choose N to continue using the legacy 8254 timer.
688
689 config HPET_EMULATE_RTC
690 def_bool y
691 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
692
693 config APB_TIMER
694 def_bool y if X86_INTEL_MID
695 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
696 select DW_APB_TIMER
697 depends on X86_INTEL_MID && SFI
698 help
699 APB timer is the replacement for 8254, HPET on X86 MID platforms.
700 The APBT provides a stable time base on SMP
701 systems, unlike the TSC, but it is more expensive to access,
702 as it is off-chip. APB timers are always running regardless of CPU
703 C states, they are used as per CPU clockevent device when possible.
704
705 # Mark as expert because too many people got it wrong.
706 # The code disables itself when not needed.
707 config DMI
708 default y
709 bool "Enable DMI scanning" if EXPERT
710 ---help---
711 Enabled scanning of DMI to identify machine quirks. Say Y
712 here unless you have verified that your setup is not
713 affected by entries in the DMI blacklist. Required by PNP
714 BIOS code.
715
716 config GART_IOMMU
717 bool "GART IOMMU support" if EXPERT
718 default y
719 select SWIOTLB
720 depends on X86_64 && PCI && AMD_NB
721 ---help---
722 Support for full DMA access of devices with 32bit memory access only
723 on systems with more than 3GB. This is usually needed for USB,
724 sound, many IDE/SATA chipsets and some other devices.
725 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
726 based hardware IOMMU and a software bounce buffer based IOMMU used
727 on Intel systems and as fallback.
728 The code is only active when needed (enough memory and limited
729 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
730 too.
731
732 config CALGARY_IOMMU
733 bool "IBM Calgary IOMMU support"
734 select SWIOTLB
735 depends on X86_64 && PCI && EXPERIMENTAL
736 ---help---
737 Support for hardware IOMMUs in IBM's xSeries x366 and x460
738 systems. Needed to run systems with more than 3GB of memory
739 properly with 32-bit PCI devices that do not support DAC
740 (Double Address Cycle). Calgary also supports bus level
741 isolation, where all DMAs pass through the IOMMU. This
742 prevents them from going anywhere except their intended
743 destination. This catches hard-to-find kernel bugs and
744 mis-behaving drivers and devices that do not use the DMA-API
745 properly to set up their DMA buffers. The IOMMU can be
746 turned off at boot time with the iommu=off parameter.
747 Normally the kernel will make the right choice by itself.
748 If unsure, say Y.
749
750 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
751 def_bool y
752 prompt "Should Calgary be enabled by default?"
753 depends on CALGARY_IOMMU
754 ---help---
755 Should Calgary be enabled by default? if you choose 'y', Calgary
756 will be used (if it exists). If you choose 'n', Calgary will not be
757 used even if it exists. If you choose 'n' and would like to use
758 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
759 If unsure, say Y.
760
761 # need this always selected by IOMMU for the VIA workaround
762 config SWIOTLB
763 def_bool y if X86_64
764 ---help---
765 Support for software bounce buffers used on x86-64 systems
766 which don't have a hardware IOMMU. Using this PCI devices
767 which can only access 32-bits of memory can be used on systems
768 with more than 3 GB of memory.
769 If unsure, say Y.
770
771 config IOMMU_HELPER
772 def_bool y
773 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
774
775 config MAXSMP
776 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
777 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
778 select CPUMASK_OFFSTACK
779 ---help---
780 Enable maximum number of CPUS and NUMA Nodes for this architecture.
781 If unsure, say N.
782
783 config NR_CPUS
784 int "Maximum number of CPUs" if SMP && !MAXSMP
785 range 2 8 if SMP && X86_32 && !X86_BIGSMP
786 range 2 512 if SMP && !MAXSMP
787 default "1" if !SMP
788 default "4096" if MAXSMP
789 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
790 default "8" if SMP
791 ---help---
792 This allows you to specify the maximum number of CPUs which this
793 kernel will support. The maximum supported value is 512 and the
794 minimum value which makes sense is 2.
795
796 This is purely to save memory - each supported CPU adds
797 approximately eight kilobytes to the kernel image.
798
799 config SCHED_SMT
800 bool "SMT (Hyperthreading) scheduler support"
801 depends on X86_HT
802 ---help---
803 SMT scheduler support improves the CPU scheduler's decision making
804 when dealing with Intel Pentium 4 chips with HyperThreading at a
805 cost of slightly increased overhead in some places. If unsure say
806 N here.
807
808 config SCHED_MC
809 def_bool y
810 prompt "Multi-core scheduler support"
811 depends on X86_HT
812 ---help---
813 Multi-core scheduler support improves the CPU scheduler's decision
814 making when dealing with multi-core CPU chips at a cost of slightly
815 increased overhead in some places. If unsure say N here.
816
817 source "kernel/Kconfig.preempt"
818
819 config X86_UP_APIC
820 bool "Local APIC support on uniprocessors"
821 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
822 ---help---
823 A local APIC (Advanced Programmable Interrupt Controller) is an
824 integrated interrupt controller in the CPU. If you have a single-CPU
825 system which has a processor with a local APIC, you can say Y here to
826 enable and use it. If you say Y here even though your machine doesn't
827 have a local APIC, then the kernel will still run with no slowdown at
828 all. The local APIC supports CPU-generated self-interrupts (timer,
829 performance counters), and the NMI watchdog which detects hard
830 lockups.
831
832 config X86_UP_IOAPIC
833 bool "IO-APIC support on uniprocessors"
834 depends on X86_UP_APIC
835 ---help---
836 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
837 SMP-capable replacement for PC-style interrupt controllers. Most
838 SMP systems and many recent uniprocessor systems have one.
839
840 If you have a single-CPU system with an IO-APIC, you can say Y here
841 to use it. If you say Y here even though your machine doesn't have
842 an IO-APIC, then the kernel will still run with no slowdown at all.
843
844 config X86_LOCAL_APIC
845 def_bool y
846 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
847
848 config X86_IO_APIC
849 def_bool y
850 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
851
852 config X86_VISWS_APIC
853 def_bool y
854 depends on X86_32 && X86_VISWS
855
856 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
857 bool "Reroute for broken boot IRQs"
858 depends on X86_IO_APIC
859 ---help---
860 This option enables a workaround that fixes a source of
861 spurious interrupts. This is recommended when threaded
862 interrupt handling is used on systems where the generation of
863 superfluous "boot interrupts" cannot be disabled.
864
865 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
866 entry in the chipset's IO-APIC is masked (as, e.g. the RT
867 kernel does during interrupt handling). On chipsets where this
868 boot IRQ generation cannot be disabled, this workaround keeps
869 the original IRQ line masked so that only the equivalent "boot
870 IRQ" is delivered to the CPUs. The workaround also tells the
871 kernel to set up the IRQ handler on the boot IRQ line. In this
872 way only one interrupt is delivered to the kernel. Otherwise
873 the spurious second interrupt may cause the kernel to bring
874 down (vital) interrupt lines.
875
876 Only affects "broken" chipsets. Interrupt sharing may be
877 increased on these systems.
878
879 config X86_MCE
880 bool "Machine Check / overheating reporting"
881 default y
882 ---help---
883 Machine Check support allows the processor to notify the
884 kernel if it detects a problem (e.g. overheating, data corruption).
885 The action the kernel takes depends on the severity of the problem,
886 ranging from warning messages to halting the machine.
887
888 config X86_MCE_INTEL
889 def_bool y
890 prompt "Intel MCE features"
891 depends on X86_MCE && X86_LOCAL_APIC
892 ---help---
893 Additional support for intel specific MCE features such as
894 the thermal monitor.
895
896 config X86_MCE_AMD
897 def_bool y
898 prompt "AMD MCE features"
899 depends on X86_MCE && X86_LOCAL_APIC
900 ---help---
901 Additional support for AMD specific MCE features such as
902 the DRAM Error Threshold.
903
904 config X86_ANCIENT_MCE
905 bool "Support for old Pentium 5 / WinChip machine checks"
906 depends on X86_32 && X86_MCE
907 ---help---
908 Include support for machine check handling on old Pentium 5 or WinChip
909 systems. These typically need to be enabled explicitely on the command
910 line.
911
912 config X86_MCE_THRESHOLD
913 depends on X86_MCE_AMD || X86_MCE_INTEL
914 def_bool y
915
916 config X86_MCE_INJECT
917 depends on X86_MCE
918 tristate "Machine check injector support"
919 ---help---
920 Provide support for injecting machine checks for testing purposes.
921 If you don't know what a machine check is and you don't do kernel
922 QA it is safe to say n.
923
924 config X86_THERMAL_VECTOR
925 def_bool y
926 depends on X86_MCE_INTEL
927
928 config VM86
929 bool "Enable VM86 support" if EXPERT
930 default y
931 depends on X86_32
932 ---help---
933 This option is required by programs like DOSEMU to run 16-bit legacy
934 code on X86 processors. It also may be needed by software like
935 XFree86 to initialize some video cards via BIOS. Disabling this
936 option saves about 6k.
937
938 config TOSHIBA
939 tristate "Toshiba Laptop support"
940 depends on X86_32
941 ---help---
942 This adds a driver to safely access the System Management Mode of
943 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
944 not work on models with a Phoenix BIOS. The System Management Mode
945 is used to set the BIOS and power saving options on Toshiba portables.
946
947 For information on utilities to make use of this driver see the
948 Toshiba Linux utilities web site at:
949 <http://www.buzzard.org.uk/toshiba/>.
950
951 Say Y if you intend to run this kernel on a Toshiba portable.
952 Say N otherwise.
953
954 config I8K
955 tristate "Dell laptop support"
956 select HWMON
957 ---help---
958 This adds a driver to safely access the System Management Mode
959 of the CPU on the Dell Inspiron 8000. The System Management Mode
960 is used to read cpu temperature and cooling fan status and to
961 control the fans on the I8K portables.
962
963 This driver has been tested only on the Inspiron 8000 but it may
964 also work with other Dell laptops. You can force loading on other
965 models by passing the parameter `force=1' to the module. Use at
966 your own risk.
967
968 For information on utilities to make use of this driver see the
969 I8K Linux utilities web site at:
970 <http://people.debian.org/~dz/i8k/>
971
972 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
973 Say N otherwise.
974
975 config X86_REBOOTFIXUPS
976 bool "Enable X86 board specific fixups for reboot"
977 depends on X86_32
978 ---help---
979 This enables chipset and/or board specific fixups to be done
980 in order to get reboot to work correctly. This is only needed on
981 some combinations of hardware and BIOS. The symptom, for which
982 this config is intended, is when reboot ends with a stalled/hung
983 system.
984
985 Currently, the only fixup is for the Geode machines using
986 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
987
988 Say Y if you want to enable the fixup. Currently, it's safe to
989 enable this option even if you don't need it.
990 Say N otherwise.
991
992 config MICROCODE
993 tristate "CPU microcode loading support"
994 select FW_LOADER
995 ---help---
996
997 If you say Y here, you will be able to update the microcode on
998 certain Intel and AMD processors. The Intel support is for the
999 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1000 Xeon etc. The AMD support is for families 0x10 and later. You will
1001 obviously need the actual microcode binary data itself which is not
1002 shipped with the Linux kernel.
1003
1004 This option selects the general module only, you need to select
1005 at least one vendor specific module as well.
1006
1007 To compile this driver as a module, choose M here: the module
1008 will be called microcode.
1009
1010 config MICROCODE_INTEL
1011 bool "Intel microcode loading support"
1012 depends on MICROCODE
1013 default MICROCODE
1014 select FW_LOADER
1015 ---help---
1016 This options enables microcode patch loading support for Intel
1017 processors.
1018
1019 For latest news and information on obtaining all the required
1020 Intel ingredients for this driver, check:
1021 <http://www.urbanmyth.org/microcode/>.
1022
1023 config MICROCODE_AMD
1024 bool "AMD microcode loading support"
1025 depends on MICROCODE
1026 select FW_LOADER
1027 ---help---
1028 If you select this option, microcode patch loading support for AMD
1029 processors will be enabled.
1030
1031 config MICROCODE_OLD_INTERFACE
1032 def_bool y
1033 depends on MICROCODE
1034
1035 config X86_MSR
1036 tristate "/dev/cpu/*/msr - Model-specific register support"
1037 ---help---
1038 This device gives privileged processes access to the x86
1039 Model-Specific Registers (MSRs). It is a character device with
1040 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1041 MSR accesses are directed to a specific CPU on multi-processor
1042 systems.
1043
1044 config X86_CPUID
1045 tristate "/dev/cpu/*/cpuid - CPU information support"
1046 ---help---
1047 This device gives processes access to the x86 CPUID instruction to
1048 be executed on a specific processor. It is a character device
1049 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1050 /dev/cpu/31/cpuid.
1051
1052 choice
1053 prompt "High Memory Support"
1054 default HIGHMEM64G if X86_NUMAQ
1055 default HIGHMEM4G
1056 depends on X86_32
1057
1058 config NOHIGHMEM
1059 bool "off"
1060 depends on !X86_NUMAQ
1061 ---help---
1062 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1063 However, the address space of 32-bit x86 processors is only 4
1064 Gigabytes large. That means that, if you have a large amount of
1065 physical memory, not all of it can be "permanently mapped" by the
1066 kernel. The physical memory that's not permanently mapped is called
1067 "high memory".
1068
1069 If you are compiling a kernel which will never run on a machine with
1070 more than 1 Gigabyte total physical RAM, answer "off" here (default
1071 choice and suitable for most users). This will result in a "3GB/1GB"
1072 split: 3GB are mapped so that each process sees a 3GB virtual memory
1073 space and the remaining part of the 4GB virtual memory space is used
1074 by the kernel to permanently map as much physical memory as
1075 possible.
1076
1077 If the machine has between 1 and 4 Gigabytes physical RAM, then
1078 answer "4GB" here.
1079
1080 If more than 4 Gigabytes is used then answer "64GB" here. This
1081 selection turns Intel PAE (Physical Address Extension) mode on.
1082 PAE implements 3-level paging on IA32 processors. PAE is fully
1083 supported by Linux, PAE mode is implemented on all recent Intel
1084 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1085 then the kernel will not boot on CPUs that don't support PAE!
1086
1087 The actual amount of total physical memory will either be
1088 auto detected or can be forced by using a kernel command line option
1089 such as "mem=256M". (Try "man bootparam" or see the documentation of
1090 your boot loader (lilo or loadlin) about how to pass options to the
1091 kernel at boot time.)
1092
1093 If unsure, say "off".
1094
1095 config HIGHMEM4G
1096 bool "4GB"
1097 depends on !X86_NUMAQ
1098 ---help---
1099 Select this if you have a 32-bit processor and between 1 and 4
1100 gigabytes of physical RAM.
1101
1102 config HIGHMEM64G
1103 bool "64GB"
1104 depends on !M386 && !M486
1105 select X86_PAE
1106 ---help---
1107 Select this if you have a 32-bit processor and more than 4
1108 gigabytes of physical RAM.
1109
1110 endchoice
1111
1112 choice
1113 depends on EXPERIMENTAL
1114 prompt "Memory split" if EXPERT
1115 default VMSPLIT_3G
1116 depends on X86_32
1117 ---help---
1118 Select the desired split between kernel and user memory.
1119
1120 If the address range available to the kernel is less than the
1121 physical memory installed, the remaining memory will be available
1122 as "high memory". Accessing high memory is a little more costly
1123 than low memory, as it needs to be mapped into the kernel first.
1124 Note that increasing the kernel address space limits the range
1125 available to user programs, making the address space there
1126 tighter. Selecting anything other than the default 3G/1G split
1127 will also likely make your kernel incompatible with binary-only
1128 kernel modules.
1129
1130 If you are not absolutely sure what you are doing, leave this
1131 option alone!
1132
1133 config VMSPLIT_3G
1134 bool "3G/1G user/kernel split"
1135 config VMSPLIT_3G_OPT
1136 depends on !X86_PAE
1137 bool "3G/1G user/kernel split (for full 1G low memory)"
1138 config VMSPLIT_2G
1139 bool "2G/2G user/kernel split"
1140 config VMSPLIT_2G_OPT
1141 depends on !X86_PAE
1142 bool "2G/2G user/kernel split (for full 2G low memory)"
1143 config VMSPLIT_1G
1144 bool "1G/3G user/kernel split"
1145 endchoice
1146
1147 config PAGE_OFFSET
1148 hex
1149 default 0xB0000000 if VMSPLIT_3G_OPT
1150 default 0x80000000 if VMSPLIT_2G
1151 default 0x78000000 if VMSPLIT_2G_OPT
1152 default 0x40000000 if VMSPLIT_1G
1153 default 0xC0000000
1154 depends on X86_32
1155
1156 config HIGHMEM
1157 def_bool y
1158 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1159
1160 config X86_PAE
1161 bool "PAE (Physical Address Extension) Support"
1162 depends on X86_32 && !HIGHMEM4G
1163 ---help---
1164 PAE is required for NX support, and furthermore enables
1165 larger swapspace support for non-overcommit purposes. It
1166 has the cost of more pagetable lookup overhead, and also
1167 consumes more pagetable space per process.
1168
1169 config ARCH_PHYS_ADDR_T_64BIT
1170 def_bool y
1171 depends on X86_64 || X86_PAE
1172
1173 config ARCH_DMA_ADDR_T_64BIT
1174 def_bool y
1175 depends on X86_64 || HIGHMEM64G
1176
1177 config DIRECT_GBPAGES
1178 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1179 default y
1180 depends on X86_64
1181 ---help---
1182 Allow the kernel linear mapping to use 1GB pages on CPUs that
1183 support it. This can improve the kernel's performance a tiny bit by
1184 reducing TLB pressure. If in doubt, say "Y".
1185
1186 # Common NUMA Features
1187 config NUMA
1188 bool "Numa Memory Allocation and Scheduler Support"
1189 depends on SMP
1190 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1191 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1192 ---help---
1193 Enable NUMA (Non Uniform Memory Access) support.
1194
1195 The kernel will try to allocate memory used by a CPU on the
1196 local memory controller of the CPU and add some more
1197 NUMA awareness to the kernel.
1198
1199 For 64-bit this is recommended if the system is Intel Core i7
1200 (or later), AMD Opteron, or EM64T NUMA.
1201
1202 For 32-bit this is only needed on (rare) 32-bit-only platforms
1203 that support NUMA topologies, such as NUMAQ / Summit, or if you
1204 boot a 32-bit kernel on a 64-bit NUMA platform.
1205
1206 Otherwise, you should say N.
1207
1208 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1209 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1210
1211 config AMD_NUMA
1212 def_bool y
1213 prompt "Old style AMD Opteron NUMA detection"
1214 depends on X86_64 && NUMA && PCI
1215 ---help---
1216 Enable AMD NUMA node topology detection. You should say Y here if
1217 you have a multi processor AMD system. This uses an old method to
1218 read the NUMA configuration directly from the builtin Northbridge
1219 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1220 which also takes priority if both are compiled in.
1221
1222 config X86_64_ACPI_NUMA
1223 def_bool y
1224 prompt "ACPI NUMA detection"
1225 depends on X86_64 && NUMA && ACPI && PCI
1226 select ACPI_NUMA
1227 ---help---
1228 Enable ACPI SRAT based node topology detection.
1229
1230 # Some NUMA nodes have memory ranges that span
1231 # other nodes. Even though a pfn is valid and
1232 # between a node's start and end pfns, it may not
1233 # reside on that node. See memmap_init_zone()
1234 # for details.
1235 config NODES_SPAN_OTHER_NODES
1236 def_bool y
1237 depends on X86_64_ACPI_NUMA
1238
1239 config NUMA_EMU
1240 bool "NUMA emulation"
1241 depends on NUMA
1242 ---help---
1243 Enable NUMA emulation. A flat machine will be split
1244 into virtual nodes when booted with "numa=fake=N", where N is the
1245 number of nodes. This is only useful for debugging.
1246
1247 config NODES_SHIFT
1248 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1249 range 1 10
1250 default "10" if MAXSMP
1251 default "6" if X86_64
1252 default "4" if X86_NUMAQ
1253 default "3"
1254 depends on NEED_MULTIPLE_NODES
1255 ---help---
1256 Specify the maximum number of NUMA Nodes available on the target
1257 system. Increases memory reserved to accommodate various tables.
1258
1259 config HAVE_ARCH_ALLOC_REMAP
1260 def_bool y
1261 depends on X86_32 && NUMA
1262
1263 config ARCH_HAVE_MEMORY_PRESENT
1264 def_bool y
1265 depends on X86_32 && DISCONTIGMEM
1266
1267 config NEED_NODE_MEMMAP_SIZE
1268 def_bool y
1269 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1270
1271 config ARCH_FLATMEM_ENABLE
1272 def_bool y
1273 depends on X86_32 && !NUMA
1274
1275 config ARCH_DISCONTIGMEM_ENABLE
1276 def_bool y
1277 depends on NUMA && X86_32
1278
1279 config ARCH_DISCONTIGMEM_DEFAULT
1280 def_bool y
1281 depends on NUMA && X86_32
1282
1283 config ARCH_SPARSEMEM_ENABLE
1284 def_bool y
1285 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1286 select SPARSEMEM_STATIC if X86_32
1287 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1288
1289 config ARCH_SPARSEMEM_DEFAULT
1290 def_bool y
1291 depends on X86_64
1292
1293 config ARCH_SELECT_MEMORY_MODEL
1294 def_bool y
1295 depends on ARCH_SPARSEMEM_ENABLE
1296
1297 config ARCH_MEMORY_PROBE
1298 def_bool y
1299 depends on X86_64 && MEMORY_HOTPLUG
1300
1301 config ARCH_PROC_KCORE_TEXT
1302 def_bool y
1303 depends on X86_64 && PROC_KCORE
1304
1305 config ILLEGAL_POINTER_VALUE
1306 hex
1307 default 0 if X86_32
1308 default 0xdead000000000000 if X86_64
1309
1310 source "mm/Kconfig"
1311
1312 config HIGHPTE
1313 bool "Allocate 3rd-level pagetables from highmem"
1314 depends on HIGHMEM
1315 ---help---
1316 The VM uses one page table entry for each page of physical memory.
1317 For systems with a lot of RAM, this can be wasteful of precious
1318 low memory. Setting this option will put user-space page table
1319 entries in high memory.
1320
1321 config X86_CHECK_BIOS_CORRUPTION
1322 bool "Check for low memory corruption"
1323 ---help---
1324 Periodically check for memory corruption in low memory, which
1325 is suspected to be caused by BIOS. Even when enabled in the
1326 configuration, it is disabled at runtime. Enable it by
1327 setting "memory_corruption_check=1" on the kernel command
1328 line. By default it scans the low 64k of memory every 60
1329 seconds; see the memory_corruption_check_size and
1330 memory_corruption_check_period parameters in
1331 Documentation/kernel-parameters.txt to adjust this.
1332
1333 When enabled with the default parameters, this option has
1334 almost no overhead, as it reserves a relatively small amount
1335 of memory and scans it infrequently. It both detects corruption
1336 and prevents it from affecting the running system.
1337
1338 It is, however, intended as a diagnostic tool; if repeatable
1339 BIOS-originated corruption always affects the same memory,
1340 you can use memmap= to prevent the kernel from using that
1341 memory.
1342
1343 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1344 bool "Set the default setting of memory_corruption_check"
1345 depends on X86_CHECK_BIOS_CORRUPTION
1346 default y
1347 ---help---
1348 Set whether the default state of memory_corruption_check is
1349 on or off.
1350
1351 config X86_RESERVE_LOW
1352 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1353 default 64
1354 range 4 640
1355 ---help---
1356 Specify the amount of low memory to reserve for the BIOS.
1357
1358 The first page contains BIOS data structures that the kernel
1359 must not use, so that page must always be reserved.
1360
1361 By default we reserve the first 64K of physical RAM, as a
1362 number of BIOSes are known to corrupt that memory range
1363 during events such as suspend/resume or monitor cable
1364 insertion, so it must not be used by the kernel.
1365
1366 You can set this to 4 if you are absolutely sure that you
1367 trust the BIOS to get all its memory reservations and usages
1368 right. If you know your BIOS have problems beyond the
1369 default 64K area, you can set this to 640 to avoid using the
1370 entire low memory range.
1371
1372 If you have doubts about the BIOS (e.g. suspend/resume does
1373 not work or there's kernel crashes after certain hardware
1374 hotplug events) then you might want to enable
1375 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1376 typical corruption patterns.
1377
1378 Leave this to the default value of 64 if you are unsure.
1379
1380 config MATH_EMULATION
1381 bool
1382 prompt "Math emulation" if X86_32
1383 ---help---
1384 Linux can emulate a math coprocessor (used for floating point
1385 operations) if you don't have one. 486DX and Pentium processors have
1386 a math coprocessor built in, 486SX and 386 do not, unless you added
1387 a 487DX or 387, respectively. (The messages during boot time can
1388 give you some hints here ["man dmesg"].) Everyone needs either a
1389 coprocessor or this emulation.
1390
1391 If you don't have a math coprocessor, you need to say Y here; if you
1392 say Y here even though you have a coprocessor, the coprocessor will
1393 be used nevertheless. (This behavior can be changed with the kernel
1394 command line option "no387", which comes handy if your coprocessor
1395 is broken. Try "man bootparam" or see the documentation of your boot
1396 loader (lilo or loadlin) about how to pass options to the kernel at
1397 boot time.) This means that it is a good idea to say Y here if you
1398 intend to use this kernel on different machines.
1399
1400 More information about the internals of the Linux math coprocessor
1401 emulation can be found in <file:arch/x86/math-emu/README>.
1402
1403 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1404 kernel, it won't hurt.
1405
1406 config MTRR
1407 def_bool y
1408 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1409 ---help---
1410 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1411 the Memory Type Range Registers (MTRRs) may be used to control
1412 processor access to memory ranges. This is most useful if you have
1413 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1414 allows bus write transfers to be combined into a larger transfer
1415 before bursting over the PCI/AGP bus. This can increase performance
1416 of image write operations 2.5 times or more. Saying Y here creates a
1417 /proc/mtrr file which may be used to manipulate your processor's
1418 MTRRs. Typically the X server should use this.
1419
1420 This code has a reasonably generic interface so that similar
1421 control registers on other processors can be easily supported
1422 as well:
1423
1424 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1425 Registers (ARRs) which provide a similar functionality to MTRRs. For
1426 these, the ARRs are used to emulate the MTRRs.
1427 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1428 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1429 write-combining. All of these processors are supported by this code
1430 and it makes sense to say Y here if you have one of them.
1431
1432 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1433 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1434 can lead to all sorts of problems, so it's good to say Y here.
1435
1436 You can safely say Y even if your machine doesn't have MTRRs, you'll
1437 just add about 9 KB to your kernel.
1438
1439 See <file:Documentation/x86/mtrr.txt> for more information.
1440
1441 config MTRR_SANITIZER
1442 def_bool y
1443 prompt "MTRR cleanup support"
1444 depends on MTRR
1445 ---help---
1446 Convert MTRR layout from continuous to discrete, so X drivers can
1447 add writeback entries.
1448
1449 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1450 The largest mtrr entry size for a continuous block can be set with
1451 mtrr_chunk_size.
1452
1453 If unsure, say Y.
1454
1455 config MTRR_SANITIZER_ENABLE_DEFAULT
1456 int "MTRR cleanup enable value (0-1)"
1457 range 0 1
1458 default "0"
1459 depends on MTRR_SANITIZER
1460 ---help---
1461 Enable mtrr cleanup default value
1462
1463 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1464 int "MTRR cleanup spare reg num (0-7)"
1465 range 0 7
1466 default "1"
1467 depends on MTRR_SANITIZER
1468 ---help---
1469 mtrr cleanup spare entries default, it can be changed via
1470 mtrr_spare_reg_nr=N on the kernel command line.
1471
1472 config X86_PAT
1473 def_bool y
1474 prompt "x86 PAT support" if EXPERT
1475 depends on MTRR
1476 ---help---
1477 Use PAT attributes to setup page level cache control.
1478
1479 PATs are the modern equivalents of MTRRs and are much more
1480 flexible than MTRRs.
1481
1482 Say N here if you see bootup problems (boot crash, boot hang,
1483 spontaneous reboots) or a non-working video driver.
1484
1485 If unsure, say Y.
1486
1487 config ARCH_USES_PG_UNCACHED
1488 def_bool y
1489 depends on X86_PAT
1490
1491 config ARCH_RANDOM
1492 def_bool y
1493 prompt "x86 architectural random number generator" if EXPERT
1494 ---help---
1495 Enable the x86 architectural RDRAND instruction
1496 (Intel Bull Mountain technology) to generate random numbers.
1497 If supported, this is a high bandwidth, cryptographically
1498 secure hardware random number generator.
1499
1500 config X86_SMAP
1501 def_bool y
1502 prompt "Supervisor Mode Access Prevention" if EXPERT
1503 ---help---
1504 Supervisor Mode Access Prevention (SMAP) is a security
1505 feature in newer Intel processors. There is a small
1506 performance cost if this enabled and turned on; there is
1507 also a small increase in the kernel size if this is enabled.
1508
1509 If unsure, say Y.
1510
1511 config EFI
1512 bool "EFI runtime service support"
1513 depends on ACPI
1514 ---help---
1515 This enables the kernel to use EFI runtime services that are
1516 available (such as the EFI variable services).
1517
1518 This option is only useful on systems that have EFI firmware.
1519 In addition, you should use the latest ELILO loader available
1520 at <http://elilo.sourceforge.net> in order to take advantage
1521 of EFI runtime services. However, even with this option, the
1522 resultant kernel should continue to boot on existing non-EFI
1523 platforms.
1524
1525 config EFI_STUB
1526 bool "EFI stub support"
1527 depends on EFI
1528 ---help---
1529 This kernel feature allows a bzImage to be loaded directly
1530 by EFI firmware without the use of a bootloader.
1531
1532 See Documentation/x86/efi-stub.txt for more information.
1533
1534 config SECCOMP
1535 def_bool y
1536 prompt "Enable seccomp to safely compute untrusted bytecode"
1537 ---help---
1538 This kernel feature is useful for number crunching applications
1539 that may need to compute untrusted bytecode during their
1540 execution. By using pipes or other transports made available to
1541 the process as file descriptors supporting the read/write
1542 syscalls, it's possible to isolate those applications in
1543 their own address space using seccomp. Once seccomp is
1544 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1545 and the task is only allowed to execute a few safe syscalls
1546 defined by each seccomp mode.
1547
1548 If unsure, say Y. Only embedded should say N here.
1549
1550 config CC_STACKPROTECTOR
1551 bool "Enable -fstack-protector buffer overflow detection"
1552 ---help---
1553 This option turns on the -fstack-protector GCC feature. This
1554 feature puts, at the beginning of functions, a canary value on
1555 the stack just before the return address, and validates
1556 the value just before actually returning. Stack based buffer
1557 overflows (that need to overwrite this return address) now also
1558 overwrite the canary, which gets detected and the attack is then
1559 neutralized via a kernel panic.
1560
1561 This feature requires gcc version 4.2 or above, or a distribution
1562 gcc with the feature backported. Older versions are automatically
1563 detected and for those versions, this configuration option is
1564 ignored. (and a warning is printed during bootup)
1565
1566 source kernel/Kconfig.hz
1567
1568 config KEXEC
1569 bool "kexec system call"
1570 ---help---
1571 kexec is a system call that implements the ability to shutdown your
1572 current kernel, and to start another kernel. It is like a reboot
1573 but it is independent of the system firmware. And like a reboot
1574 you can start any kernel with it, not just Linux.
1575
1576 The name comes from the similarity to the exec system call.
1577
1578 It is an ongoing process to be certain the hardware in a machine
1579 is properly shutdown, so do not be surprised if this code does not
1580 initially work for you. It may help to enable device hotplugging
1581 support. As of this writing the exact hardware interface is
1582 strongly in flux, so no good recommendation can be made.
1583
1584 config CRASH_DUMP
1585 bool "kernel crash dumps"
1586 depends on X86_64 || (X86_32 && HIGHMEM)
1587 ---help---
1588 Generate crash dump after being started by kexec.
1589 This should be normally only set in special crash dump kernels
1590 which are loaded in the main kernel with kexec-tools into
1591 a specially reserved region and then later executed after
1592 a crash by kdump/kexec. The crash dump kernel must be compiled
1593 to a memory address not used by the main kernel or BIOS using
1594 PHYSICAL_START, or it must be built as a relocatable image
1595 (CONFIG_RELOCATABLE=y).
1596 For more details see Documentation/kdump/kdump.txt
1597
1598 config KEXEC_JUMP
1599 bool "kexec jump (EXPERIMENTAL)"
1600 depends on EXPERIMENTAL
1601 depends on KEXEC && HIBERNATION
1602 ---help---
1603 Jump between original kernel and kexeced kernel and invoke
1604 code in physical address mode via KEXEC
1605
1606 config PHYSICAL_START
1607 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1608 default "0x1000000"
1609 ---help---
1610 This gives the physical address where the kernel is loaded.
1611
1612 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1613 bzImage will decompress itself to above physical address and
1614 run from there. Otherwise, bzImage will run from the address where
1615 it has been loaded by the boot loader and will ignore above physical
1616 address.
1617
1618 In normal kdump cases one does not have to set/change this option
1619 as now bzImage can be compiled as a completely relocatable image
1620 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1621 address. This option is mainly useful for the folks who don't want
1622 to use a bzImage for capturing the crash dump and want to use a
1623 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1624 to be specifically compiled to run from a specific memory area
1625 (normally a reserved region) and this option comes handy.
1626
1627 So if you are using bzImage for capturing the crash dump,
1628 leave the value here unchanged to 0x1000000 and set
1629 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1630 for capturing the crash dump change this value to start of
1631 the reserved region. In other words, it can be set based on
1632 the "X" value as specified in the "crashkernel=YM@XM"
1633 command line boot parameter passed to the panic-ed
1634 kernel. Please take a look at Documentation/kdump/kdump.txt
1635 for more details about crash dumps.
1636
1637 Usage of bzImage for capturing the crash dump is recommended as
1638 one does not have to build two kernels. Same kernel can be used
1639 as production kernel and capture kernel. Above option should have
1640 gone away after relocatable bzImage support is introduced. But it
1641 is present because there are users out there who continue to use
1642 vmlinux for dump capture. This option should go away down the
1643 line.
1644
1645 Don't change this unless you know what you are doing.
1646
1647 config RELOCATABLE
1648 bool "Build a relocatable kernel"
1649 default y
1650 ---help---
1651 This builds a kernel image that retains relocation information
1652 so it can be loaded someplace besides the default 1MB.
1653 The relocations tend to make the kernel binary about 10% larger,
1654 but are discarded at runtime.
1655
1656 One use is for the kexec on panic case where the recovery kernel
1657 must live at a different physical address than the primary
1658 kernel.
1659
1660 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1661 it has been loaded at and the compile time physical address
1662 (CONFIG_PHYSICAL_START) is ignored.
1663
1664 # Relocation on x86-32 needs some additional build support
1665 config X86_NEED_RELOCS
1666 def_bool y
1667 depends on X86_32 && RELOCATABLE
1668
1669 config PHYSICAL_ALIGN
1670 hex "Alignment value to which kernel should be aligned" if X86_32
1671 default "0x1000000"
1672 range 0x2000 0x1000000
1673 ---help---
1674 This value puts the alignment restrictions on physical address
1675 where kernel is loaded and run from. Kernel is compiled for an
1676 address which meets above alignment restriction.
1677
1678 If bootloader loads the kernel at a non-aligned address and
1679 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1680 address aligned to above value and run from there.
1681
1682 If bootloader loads the kernel at a non-aligned address and
1683 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1684 load address and decompress itself to the address it has been
1685 compiled for and run from there. The address for which kernel is
1686 compiled already meets above alignment restrictions. Hence the
1687 end result is that kernel runs from a physical address meeting
1688 above alignment restrictions.
1689
1690 Don't change this unless you know what you are doing.
1691
1692 config HOTPLUG_CPU
1693 bool "Support for hot-pluggable CPUs"
1694 depends on SMP && HOTPLUG
1695 ---help---
1696 Say Y here to allow turning CPUs off and on. CPUs can be
1697 controlled through /sys/devices/system/cpu.
1698 ( Note: power management support will enable this option
1699 automatically on SMP systems. )
1700 Say N if you want to disable CPU hotplug.
1701
1702 config COMPAT_VDSO
1703 def_bool y
1704 prompt "Compat VDSO support"
1705 depends on X86_32 || IA32_EMULATION
1706 ---help---
1707 Map the 32-bit VDSO to the predictable old-style address too.
1708
1709 Say N here if you are running a sufficiently recent glibc
1710 version (2.3.3 or later), to remove the high-mapped
1711 VDSO mapping and to exclusively use the randomized VDSO.
1712
1713 If unsure, say Y.
1714
1715 config CMDLINE_BOOL
1716 bool "Built-in kernel command line"
1717 ---help---
1718 Allow for specifying boot arguments to the kernel at
1719 build time. On some systems (e.g. embedded ones), it is
1720 necessary or convenient to provide some or all of the
1721 kernel boot arguments with the kernel itself (that is,
1722 to not rely on the boot loader to provide them.)
1723
1724 To compile command line arguments into the kernel,
1725 set this option to 'Y', then fill in the
1726 the boot arguments in CONFIG_CMDLINE.
1727
1728 Systems with fully functional boot loaders (i.e. non-embedded)
1729 should leave this option set to 'N'.
1730
1731 config CMDLINE
1732 string "Built-in kernel command string"
1733 depends on CMDLINE_BOOL
1734 default ""
1735 ---help---
1736 Enter arguments here that should be compiled into the kernel
1737 image and used at boot time. If the boot loader provides a
1738 command line at boot time, it is appended to this string to
1739 form the full kernel command line, when the system boots.
1740
1741 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1742 change this behavior.
1743
1744 In most cases, the command line (whether built-in or provided
1745 by the boot loader) should specify the device for the root
1746 file system.
1747
1748 config CMDLINE_OVERRIDE
1749 bool "Built-in command line overrides boot loader arguments"
1750 depends on CMDLINE_BOOL
1751 ---help---
1752 Set this option to 'Y' to have the kernel ignore the boot loader
1753 command line, and use ONLY the built-in command line.
1754
1755 This is used to work around broken boot loaders. This should
1756 be set to 'N' under normal conditions.
1757
1758 endmenu
1759
1760 config ARCH_ENABLE_MEMORY_HOTPLUG
1761 def_bool y
1762 depends on X86_64 || (X86_32 && HIGHMEM)
1763
1764 config ARCH_ENABLE_MEMORY_HOTREMOVE
1765 def_bool y
1766 depends on MEMORY_HOTPLUG
1767
1768 config USE_PERCPU_NUMA_NODE_ID
1769 def_bool y
1770 depends on NUMA
1771
1772 menu "Power management and ACPI options"
1773
1774 config ARCH_HIBERNATION_HEADER
1775 def_bool y
1776 depends on X86_64 && HIBERNATION
1777
1778 source "kernel/power/Kconfig"
1779
1780 source "drivers/acpi/Kconfig"
1781
1782 source "drivers/sfi/Kconfig"
1783
1784 config X86_APM_BOOT
1785 def_bool y
1786 depends on APM
1787
1788 menuconfig APM
1789 tristate "APM (Advanced Power Management) BIOS support"
1790 depends on X86_32 && PM_SLEEP
1791 ---help---
1792 APM is a BIOS specification for saving power using several different
1793 techniques. This is mostly useful for battery powered laptops with
1794 APM compliant BIOSes. If you say Y here, the system time will be
1795 reset after a RESUME operation, the /proc/apm device will provide
1796 battery status information, and user-space programs will receive
1797 notification of APM "events" (e.g. battery status change).
1798
1799 If you select "Y" here, you can disable actual use of the APM
1800 BIOS by passing the "apm=off" option to the kernel at boot time.
1801
1802 Note that the APM support is almost completely disabled for
1803 machines with more than one CPU.
1804
1805 In order to use APM, you will need supporting software. For location
1806 and more information, read <file:Documentation/power/apm-acpi.txt>
1807 and the Battery Powered Linux mini-HOWTO, available from
1808 <http://www.tldp.org/docs.html#howto>.
1809
1810 This driver does not spin down disk drives (see the hdparm(8)
1811 manpage ("man 8 hdparm") for that), and it doesn't turn off
1812 VESA-compliant "green" monitors.
1813
1814 This driver does not support the TI 4000M TravelMate and the ACER
1815 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1816 desktop machines also don't have compliant BIOSes, and this driver
1817 may cause those machines to panic during the boot phase.
1818
1819 Generally, if you don't have a battery in your machine, there isn't
1820 much point in using this driver and you should say N. If you get
1821 random kernel OOPSes or reboots that don't seem to be related to
1822 anything, try disabling/enabling this option (or disabling/enabling
1823 APM in your BIOS).
1824
1825 Some other things you should try when experiencing seemingly random,
1826 "weird" problems:
1827
1828 1) make sure that you have enough swap space and that it is
1829 enabled.
1830 2) pass the "no-hlt" option to the kernel
1831 3) switch on floating point emulation in the kernel and pass
1832 the "no387" option to the kernel
1833 4) pass the "floppy=nodma" option to the kernel
1834 5) pass the "mem=4M" option to the kernel (thereby disabling
1835 all but the first 4 MB of RAM)
1836 6) make sure that the CPU is not over clocked.
1837 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1838 8) disable the cache from your BIOS settings
1839 9) install a fan for the video card or exchange video RAM
1840 10) install a better fan for the CPU
1841 11) exchange RAM chips
1842 12) exchange the motherboard.
1843
1844 To compile this driver as a module, choose M here: the
1845 module will be called apm.
1846
1847 if APM
1848
1849 config APM_IGNORE_USER_SUSPEND
1850 bool "Ignore USER SUSPEND"
1851 ---help---
1852 This option will ignore USER SUSPEND requests. On machines with a
1853 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1854 series notebooks, it is necessary to say Y because of a BIOS bug.
1855
1856 config APM_DO_ENABLE
1857 bool "Enable PM at boot time"
1858 ---help---
1859 Enable APM features at boot time. From page 36 of the APM BIOS
1860 specification: "When disabled, the APM BIOS does not automatically
1861 power manage devices, enter the Standby State, enter the Suspend
1862 State, or take power saving steps in response to CPU Idle calls."
1863 This driver will make CPU Idle calls when Linux is idle (unless this
1864 feature is turned off -- see "Do CPU IDLE calls", below). This
1865 should always save battery power, but more complicated APM features
1866 will be dependent on your BIOS implementation. You may need to turn
1867 this option off if your computer hangs at boot time when using APM
1868 support, or if it beeps continuously instead of suspending. Turn
1869 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1870 T400CDT. This is off by default since most machines do fine without
1871 this feature.
1872
1873 config APM_CPU_IDLE
1874 bool "Make CPU Idle calls when idle"
1875 ---help---
1876 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1877 On some machines, this can activate improved power savings, such as
1878 a slowed CPU clock rate, when the machine is idle. These idle calls
1879 are made after the idle loop has run for some length of time (e.g.,
1880 333 mS). On some machines, this will cause a hang at boot time or
1881 whenever the CPU becomes idle. (On machines with more than one CPU,
1882 this option does nothing.)
1883
1884 config APM_DISPLAY_BLANK
1885 bool "Enable console blanking using APM"
1886 ---help---
1887 Enable console blanking using the APM. Some laptops can use this to
1888 turn off the LCD backlight when the screen blanker of the Linux
1889 virtual console blanks the screen. Note that this is only used by
1890 the virtual console screen blanker, and won't turn off the backlight
1891 when using the X Window system. This also doesn't have anything to
1892 do with your VESA-compliant power-saving monitor. Further, this
1893 option doesn't work for all laptops -- it might not turn off your
1894 backlight at all, or it might print a lot of errors to the console,
1895 especially if you are using gpm.
1896
1897 config APM_ALLOW_INTS
1898 bool "Allow interrupts during APM BIOS calls"
1899 ---help---
1900 Normally we disable external interrupts while we are making calls to
1901 the APM BIOS as a measure to lessen the effects of a badly behaving
1902 BIOS implementation. The BIOS should reenable interrupts if it
1903 needs to. Unfortunately, some BIOSes do not -- especially those in
1904 many of the newer IBM Thinkpads. If you experience hangs when you
1905 suspend, try setting this to Y. Otherwise, say N.
1906
1907 endif # APM
1908
1909 source "drivers/cpufreq/Kconfig"
1910
1911 source "drivers/cpuidle/Kconfig"
1912
1913 source "drivers/idle/Kconfig"
1914
1915 endmenu
1916
1917
1918 menu "Bus options (PCI etc.)"
1919
1920 config PCI
1921 bool "PCI support"
1922 default y
1923 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1924 ---help---
1925 Find out whether you have a PCI motherboard. PCI is the name of a
1926 bus system, i.e. the way the CPU talks to the other stuff inside
1927 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1928 VESA. If you have PCI, say Y, otherwise N.
1929
1930 choice
1931 prompt "PCI access mode"
1932 depends on X86_32 && PCI
1933 default PCI_GOANY
1934 ---help---
1935 On PCI systems, the BIOS can be used to detect the PCI devices and
1936 determine their configuration. However, some old PCI motherboards
1937 have BIOS bugs and may crash if this is done. Also, some embedded
1938 PCI-based systems don't have any BIOS at all. Linux can also try to
1939 detect the PCI hardware directly without using the BIOS.
1940
1941 With this option, you can specify how Linux should detect the
1942 PCI devices. If you choose "BIOS", the BIOS will be used,
1943 if you choose "Direct", the BIOS won't be used, and if you
1944 choose "MMConfig", then PCI Express MMCONFIG will be used.
1945 If you choose "Any", the kernel will try MMCONFIG, then the
1946 direct access method and falls back to the BIOS if that doesn't
1947 work. If unsure, go with the default, which is "Any".
1948
1949 config PCI_GOBIOS
1950 bool "BIOS"
1951
1952 config PCI_GOMMCONFIG
1953 bool "MMConfig"
1954
1955 config PCI_GODIRECT
1956 bool "Direct"
1957
1958 config PCI_GOOLPC
1959 bool "OLPC XO-1"
1960 depends on OLPC
1961
1962 config PCI_GOANY
1963 bool "Any"
1964
1965 endchoice
1966
1967 config PCI_BIOS
1968 def_bool y
1969 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1970
1971 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1972 config PCI_DIRECT
1973 def_bool y
1974 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1975
1976 config PCI_MMCONFIG
1977 def_bool y
1978 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1979
1980 config PCI_OLPC
1981 def_bool y
1982 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1983
1984 config PCI_XEN
1985 def_bool y
1986 depends on PCI && XEN
1987 select SWIOTLB_XEN
1988
1989 config PCI_DOMAINS
1990 def_bool y
1991 depends on PCI
1992
1993 config PCI_MMCONFIG
1994 bool "Support mmconfig PCI config space access"
1995 depends on X86_64 && PCI && ACPI
1996
1997 config PCI_CNB20LE_QUIRK
1998 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1999 depends on PCI && EXPERIMENTAL
2000 help
2001 Read the PCI windows out of the CNB20LE host bridge. This allows
2002 PCI hotplug to work on systems with the CNB20LE chipset which do
2003 not have ACPI.
2004
2005 There's no public spec for this chipset, and this functionality
2006 is known to be incomplete.
2007
2008 You should say N unless you know you need this.
2009
2010 source "drivers/pci/pcie/Kconfig"
2011
2012 source "drivers/pci/Kconfig"
2013
2014 # x86_64 have no ISA slots, but can have ISA-style DMA.
2015 config ISA_DMA_API
2016 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2017 default y
2018 help
2019 Enables ISA-style DMA support for devices requiring such controllers.
2020 If unsure, say Y.
2021
2022 if X86_32
2023
2024 config ISA
2025 bool "ISA support"
2026 ---help---
2027 Find out whether you have ISA slots on your motherboard. ISA is the
2028 name of a bus system, i.e. the way the CPU talks to the other stuff
2029 inside your box. Other bus systems are PCI, EISA, MicroChannel
2030 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2031 newer boards don't support it. If you have ISA, say Y, otherwise N.
2032
2033 config EISA
2034 bool "EISA support"
2035 depends on ISA
2036 ---help---
2037 The Extended Industry Standard Architecture (EISA) bus was
2038 developed as an open alternative to the IBM MicroChannel bus.
2039
2040 The EISA bus provided some of the features of the IBM MicroChannel
2041 bus while maintaining backward compatibility with cards made for
2042 the older ISA bus. The EISA bus saw limited use between 1988 and
2043 1995 when it was made obsolete by the PCI bus.
2044
2045 Say Y here if you are building a kernel for an EISA-based machine.
2046
2047 Otherwise, say N.
2048
2049 source "drivers/eisa/Kconfig"
2050
2051 config SCx200
2052 tristate "NatSemi SCx200 support"
2053 ---help---
2054 This provides basic support for National Semiconductor's
2055 (now AMD's) Geode processors. The driver probes for the
2056 PCI-IDs of several on-chip devices, so its a good dependency
2057 for other scx200_* drivers.
2058
2059 If compiled as a module, the driver is named scx200.
2060
2061 config SCx200HR_TIMER
2062 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2063 depends on SCx200
2064 default y
2065 ---help---
2066 This driver provides a clocksource built upon the on-chip
2067 27MHz high-resolution timer. Its also a workaround for
2068 NSC Geode SC-1100's buggy TSC, which loses time when the
2069 processor goes idle (as is done by the scheduler). The
2070 other workaround is idle=poll boot option.
2071
2072 config OLPC
2073 bool "One Laptop Per Child support"
2074 depends on !X86_PAE
2075 select GPIOLIB
2076 select OF
2077 select OF_PROMTREE
2078 select IRQ_DOMAIN
2079 ---help---
2080 Add support for detecting the unique features of the OLPC
2081 XO hardware.
2082
2083 config OLPC_XO1_PM
2084 bool "OLPC XO-1 Power Management"
2085 depends on OLPC && MFD_CS5535 && PM_SLEEP
2086 select MFD_CORE
2087 ---help---
2088 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2089
2090 config OLPC_XO1_RTC
2091 bool "OLPC XO-1 Real Time Clock"
2092 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2093 ---help---
2094 Add support for the XO-1 real time clock, which can be used as a
2095 programmable wakeup source.
2096
2097 config OLPC_XO1_SCI
2098 bool "OLPC XO-1 SCI extras"
2099 depends on OLPC && OLPC_XO1_PM
2100 select POWER_SUPPLY
2101 select GPIO_CS5535
2102 select MFD_CORE
2103 ---help---
2104 Add support for SCI-based features of the OLPC XO-1 laptop:
2105 - EC-driven system wakeups
2106 - Power button
2107 - Ebook switch
2108 - Lid switch
2109 - AC adapter status updates
2110 - Battery status updates
2111
2112 config OLPC_XO15_SCI
2113 bool "OLPC XO-1.5 SCI extras"
2114 depends on OLPC && ACPI
2115 select POWER_SUPPLY
2116 ---help---
2117 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2118 - EC-driven system wakeups
2119 - AC adapter status updates
2120 - Battery status updates
2121
2122 config ALIX
2123 bool "PCEngines ALIX System Support (LED setup)"
2124 select GPIOLIB
2125 ---help---
2126 This option enables system support for the PCEngines ALIX.
2127 At present this just sets up LEDs for GPIO control on
2128 ALIX2/3/6 boards. However, other system specific setup should
2129 get added here.
2130
2131 Note: You must still enable the drivers for GPIO and LED support
2132 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2133
2134 Note: You have to set alix.force=1 for boards with Award BIOS.
2135
2136 config NET5501
2137 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2138 select GPIOLIB
2139 ---help---
2140 This option enables system support for the Soekris Engineering net5501.
2141
2142 config GEOS
2143 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2144 select GPIOLIB
2145 depends on DMI
2146 ---help---
2147 This option enables system support for the Traverse Technologies GEOS.
2148
2149 endif # X86_32
2150
2151 config AMD_NB
2152 def_bool y
2153 depends on CPU_SUP_AMD && PCI
2154
2155 source "drivers/pcmcia/Kconfig"
2156
2157 source "drivers/pci/hotplug/Kconfig"
2158
2159 config RAPIDIO
2160 bool "RapidIO support"
2161 depends on PCI
2162 default n
2163 help
2164 If you say Y here, the kernel will include drivers and
2165 infrastructure code to support RapidIO interconnect devices.
2166
2167 source "drivers/rapidio/Kconfig"
2168
2169 endmenu
2170
2171
2172 menu "Executable file formats / Emulations"
2173
2174 source "fs/Kconfig.binfmt"
2175
2176 config IA32_EMULATION
2177 bool "IA32 Emulation"
2178 depends on X86_64
2179 select COMPAT_BINFMT_ELF
2180 select HAVE_UID16
2181 ---help---
2182 Include code to run legacy 32-bit programs under a
2183 64-bit kernel. You should likely turn this on, unless you're
2184 100% sure that you don't have any 32-bit programs left.
2185
2186 config IA32_AOUT
2187 tristate "IA32 a.out support"
2188 depends on IA32_EMULATION
2189 ---help---
2190 Support old a.out binaries in the 32bit emulation.
2191
2192 config X86_X32
2193 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2194 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2195 ---help---
2196 Include code to run binaries for the x32 native 32-bit ABI
2197 for 64-bit processors. An x32 process gets access to the
2198 full 64-bit register file and wide data path while leaving
2199 pointers at 32 bits for smaller memory footprint.
2200
2201 You will need a recent binutils (2.22 or later) with
2202 elf32_x86_64 support enabled to compile a kernel with this
2203 option set.
2204
2205 config COMPAT
2206 def_bool y
2207 depends on IA32_EMULATION || X86_X32
2208 select ARCH_WANT_OLD_COMPAT_IPC
2209
2210 if COMPAT
2211 config COMPAT_FOR_U64_ALIGNMENT
2212 def_bool y
2213
2214 config SYSVIPC_COMPAT
2215 def_bool y
2216 depends on SYSVIPC
2217
2218 config KEYS_COMPAT
2219 def_bool y
2220 depends on KEYS
2221 endif
2222
2223 endmenu
2224
2225
2226 config HAVE_ATOMIC_IOMAP
2227 def_bool y
2228 depends on X86_32
2229
2230 config HAVE_TEXT_POKE_SMP
2231 bool
2232 select STOP_MACHINE if SMP
2233
2234 config X86_DEV_DMA_OPS
2235 bool
2236 depends on X86_64 || STA2X11
2237
2238 config X86_DMA_REMAP
2239 bool
2240 depends on STA2X11
2241
2242 source "net/Kconfig"
2243
2244 source "drivers/Kconfig"
2245
2246 source "drivers/firmware/Kconfig"
2247
2248 source "fs/Kconfig"
2249
2250 source "arch/x86/Kconfig.debug"
2251
2252 source "security/Kconfig"
2253
2254 source "crypto/Kconfig"
2255
2256 source "arch/x86/kvm/Kconfig"
2257
2258 source "lib/Kconfig"