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