stack-protector: test compiler capability in Kconfig and drop AUTO mode
[linux-block.git] / arch / x86 / Kconfig
CommitLineData
b2441318 1# SPDX-License-Identifier: GPL-2.0
daa93fab
SR
2# Select 32 or 64 bit
3config 64BIT
104daea1
MY
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
8f9ca475 6 ---help---
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SR
7 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
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JB
11 def_bool y
12 depends on !64BIT
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IM
13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
daa93fab
SR
21
22config X86_64
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JB
23 def_bool y
24 depends on 64BIT
d94e0685 25 # Options that are inherently 64-bit kernel only:
e1073d1e 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
d94e0685
IM
27 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
f616ab59 31 select NEED_DMA_MAP_STATE
09230cbc 32 select SWIOTLB
d94e0685 33 select X86_DEV_DMA_OPS
f8781c4a 34 select ARCH_HAS_SYSCALL_WRAPPER
1032c0ba 35
d94e0685
IM
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40# ported to 32-bit as well. )
41#
8d5fffb9 42config X86
3c2362e6 43 def_bool y
c763ea26
IM
44 #
45 # Note: keep this list sorted alphabetically
46 #
6471b825
IM
47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
49 select ANON_INODES
50 select ARCH_CLOCKSOURCE_DATA
51 select ARCH_DISCARD_MEMBLOCK
c763ea26 52 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 53 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 54 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 55 select ARCH_HAS_ELF_RANDOMIZE
72d93104 56 select ARCH_HAS_FAST_MULTIPLIER
316d097c 57 select ARCH_HAS_FILTER_PGPROT
6974f0c4 58 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 59 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 60 select ARCH_HAS_KCOV if X86_64
10bcc80e 61 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 62 select ARCH_HAS_PMEM_API if X86_64
39208aa7 63 select ARCH_HAS_REFCOUNT
0aed55af 64 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
8780356e 65 select ARCH_HAS_UACCESS_MCSAFE if X86_64
d2852a22 66 select ARCH_HAS_SET_MEMORY
6471b825 67 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
68 select ARCH_HAS_STRICT_KERNEL_RWX
69 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 70 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
c6d30853 71 select ARCH_HAS_UBSAN_SANITIZE_ALL
65f7d049 72 select ARCH_HAS_ZONE_DEVICE if X86_64
6471b825
IM
73 select ARCH_HAVE_NMI_SAFE_CMPXCHG
74 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 75 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 76 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 77 select ARCH_SUPPORTS_ATOMIC_RMW
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IM
78 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
79 select ARCH_USE_BUILTIN_BSWAP
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IM
80 select ARCH_USE_QUEUED_RWLOCKS
81 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 82 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 83 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
38d8b4e6 84 select ARCH_WANTS_THP_SWAP if X86_64
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IM
85 select BUILDTIME_EXTABLE_SORT
86 select CLKEVT_I8253
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IM
87 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
88 select CLOCKSOURCE_WATCHDOG
6471b825 89 select DCACHE_WORD_ACCESS
fec777c3 90 select DMA_DIRECT_OPS
45471cd9
LT
91 select EDAC_ATOMIC_SCRUB
92 select EDAC_SUPPORT
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IM
93 select GENERIC_CLOCKEVENTS
94 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select GENERIC_CMOS_UPDATE
97 select GENERIC_CPU_AUTOPROBE
61dc0f55 98 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 99 select GENERIC_EARLY_IOREMAP
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IM
100 select GENERIC_FIND_FIRST_BIT
101 select GENERIC_IOMAP
c7d6c9dd 102 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 103 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 104 select GENERIC_IRQ_MIGRATION if SMP
6471b825 105 select GENERIC_IRQ_PROBE
c201c917 106 select GENERIC_IRQ_RESERVATION_MODE
6471b825
IM
107 select GENERIC_IRQ_SHOW
108 select GENERIC_PENDING_IRQ if SMP
109 select GENERIC_SMP_IDLE_THREAD
110 select GENERIC_STRNCPY_FROM_USER
111 select GENERIC_STRNLEN_USER
112 select GENERIC_TIME_VSYSCALL
7edaeb68 113 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
6471b825
IM
114 select HAVE_ACPI_APEI if ACPI
115 select HAVE_ACPI_APEI_NMI if ACPI
116 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
117 select HAVE_ARCH_AUDITSYSCALL
118 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
119 select HAVE_ARCH_JUMP_LABEL
d17a1d97 120 select HAVE_ARCH_KASAN if X86_64
6471b825 121 select HAVE_ARCH_KGDB
9e08f57d
DC
122 select HAVE_ARCH_MMAP_RND_BITS if MMU
123 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 124 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
6471b825 125 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 126 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
6471b825
IM
127 select HAVE_ARCH_TRACEHOOK
128 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 129 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 130 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 131 select HAVE_ARCH_WITHIN_STACK_FRAMES
2a61f474 132 select HAVE_CC_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
6471b825
IM
133 select HAVE_CMPXCHG_DOUBLE
134 select HAVE_CMPXCHG_LOCAL
135 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 136 select HAVE_COPY_THREAD_TLS
cf4db259 137 select HAVE_C_RECORDMCOUNT
6471b825
IM
138 select HAVE_DEBUG_KMEMLEAK
139 select HAVE_DEBUG_STACKOVERFLOW
6471b825 140 select HAVE_DMA_CONTIGUOUS
677aa9f7 141 select HAVE_DYNAMIC_FTRACE
06aeaaea 142 select HAVE_DYNAMIC_FTRACE_WITH_REGS
03f5781b 143 select HAVE_EBPF_JIT
58340a07 144 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 145 select HAVE_EXIT_THREAD
644e0e8d 146 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 147 select HAVE_FTRACE_MCOUNT_RECORD
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IM
148 select HAVE_FUNCTION_GRAPH_TRACER
149 select HAVE_FUNCTION_TRACER
6b90bd4b 150 select HAVE_GCC_PLUGINS
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IM
151 select HAVE_HW_BREAKPOINT
152 select HAVE_IDE
153 select HAVE_IOREMAP_PROT
154 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
155 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 156 select HAVE_KERNEL_BZIP2
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IM
157 select HAVE_KERNEL_GZIP
158 select HAVE_KERNEL_LZ4
2e9f3bdd 159 select HAVE_KERNEL_LZMA
13510997 160 select HAVE_KERNEL_LZO
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IM
161 select HAVE_KERNEL_XZ
162 select HAVE_KPROBES
163 select HAVE_KPROBES_ON_FTRACE
540adea3 164 select HAVE_FUNCTION_ERROR_INJECTION
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IM
165 select HAVE_KRETPROBES
166 select HAVE_KVM
167 select HAVE_LIVEPATCH if X86_64
168 select HAVE_MEMBLOCK
169 select HAVE_MEMBLOCK_NODE_MAP
0102752e 170 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 171 select HAVE_MOD_ARCH_SPECIFIC
42a0bb3f 172 select HAVE_NMI
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IM
173 select HAVE_OPROFILE
174 select HAVE_OPTPROBES
175 select HAVE_PCSPKR_PLATFORM
176 select HAVE_PERF_EVENTS
c01d4323 177 select HAVE_PERF_EVENTS_NMI
92e5aae4 178 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
c5e63197 179 select HAVE_PERF_REGS
c5ebcedb 180 select HAVE_PERF_USER_STACK_DUMP
9e52fc2b 181 select HAVE_RCU_TABLE_FREE
6471b825 182 select HAVE_REGS_AND_STACK_ACCESS_API
11af8474 183 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
c763ea26 184 select HAVE_STACK_VALIDATION if X86_64
6471b825 185 select HAVE_SYSCALL_TRACEPOINTS
6471b825 186 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 187 select HAVE_USER_RETURN_NOTIFIER
c0185808 188 select IRQ_FORCED_THREADING
86596f0a 189 select NEED_SG_DMA_LENGTH
df65c1bc 190 select PCI_LOCKLESS_CONFIG
6471b825 191 select PERF_EVENTS
3195ef59 192 select RTC_LIB
d6faca40 193 select RTC_MC146818_LIB
6471b825 194 select SPARSE_IRQ
83fe27ea 195 select SRCU
6471b825 196 select SYSCTL_EXCEPTION_TRACE
15f4eae7 197 select THREAD_INFO_IN_TASK
6471b825
IM
198 select USER_STACKTRACE_SUPPORT
199 select VIRT_TO_BUS
6471b825 200 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 201
ba7e4d13 202config INSTRUCTION_DECODER
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JB
203 def_bool y
204 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 205
51b26ada
LT
206config OUTPUT_FORMAT
207 string
208 default "elf32-i386" if X86_32
209 default "elf64-x86-64" if X86_64
210
73531905 211config ARCH_DEFCONFIG
b9b39bfb 212 string
73531905
SR
213 default "arch/x86/configs/i386_defconfig" if X86_32
214 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 215
8d5fffb9 216config LOCKDEP_SUPPORT
3c2362e6 217 def_bool y
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SR
218
219config STACKTRACE_SUPPORT
3c2362e6 220 def_bool y
8d5fffb9 221
8d5fffb9 222config MMU
3c2362e6 223 def_bool y
8d5fffb9 224
9e08f57d
DC
225config ARCH_MMAP_RND_BITS_MIN
226 default 28 if 64BIT
227 default 8
228
229config ARCH_MMAP_RND_BITS_MAX
230 default 32 if 64BIT
231 default 16
232
233config ARCH_MMAP_RND_COMPAT_BITS_MIN
234 default 8
235
236config ARCH_MMAP_RND_COMPAT_BITS_MAX
237 default 16
238
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SR
239config SBUS
240 bool
241
242config GENERIC_ISA_DMA
3120e25e
JB
243 def_bool y
244 depends on ISA_DMA_API
8d5fffb9 245
8d5fffb9 246config GENERIC_BUG
3c2362e6 247 def_bool y
8d5fffb9 248 depends on BUG
b93a531e
JB
249 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
250
251config GENERIC_BUG_RELATIVE_POINTERS
252 bool
8d5fffb9
SR
253
254config GENERIC_HWEIGHT
3c2362e6 255 def_bool y
8d5fffb9
SR
256
257config ARCH_MAY_HAVE_PC_FDC
3120e25e
JB
258 def_bool y
259 depends on ISA_DMA_API
8d5fffb9 260
1032c0ba 261config RWSEM_XCHGADD_ALGORITHM
3120e25e 262 def_bool y
1032c0ba 263
1032c0ba
SR
264config GENERIC_CALIBRATE_DELAY
265 def_bool y
266
9a0b8415 267config ARCH_HAS_CPU_RELAX
268 def_bool y
269
1b27d05b
PE
270config ARCH_HAS_CACHE_LINE_SIZE
271 def_bool y
272
316d097c
DH
273config ARCH_HAS_FILTER_PGPROT
274 def_bool y
275
dd5af90a 276config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 277 def_bool y
b32ef636 278
08fc4580
TH
279config NEED_PER_CPU_EMBED_FIRST_CHUNK
280 def_bool y
281
282config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
283 def_bool y
284
801e4062
JB
285config ARCH_HIBERNATION_POSSIBLE
286 def_bool y
801e4062 287
f4cb5700
JB
288config ARCH_SUSPEND_POSSIBLE
289 def_bool y
f4cb5700 290
cfe28c5d
SC
291config ARCH_WANT_HUGE_PMD_SHARE
292 def_bool y
293
53313b2c
SC
294config ARCH_WANT_GENERAL_HUGETLB
295 def_bool y
296
8d5fffb9 297config ZONE_DMA32
e0fd24a3 298 def_bool y if X86_64
8d5fffb9 299
8d5fffb9 300config AUDIT_ARCH
e0fd24a3 301 def_bool y if X86_64
8d5fffb9 302
765c68bd
IM
303config ARCH_SUPPORTS_OPTIMIZED_INLINING
304 def_bool y
305
6a11f75b
AM
306config ARCH_SUPPORTS_DEBUG_PAGEALLOC
307 def_bool y
308
d6f2d75a
AR
309config KASAN_SHADOW_OFFSET
310 hex
311 depends on KASAN
312 default 0xdffffc0000000000
313
69575d38
SW
314config HAVE_INTEL_TXT
315 def_bool y
6ea30386 316 depends on INTEL_IOMMU && ACPI
69575d38 317
6b0c3d44
SR
318config X86_32_SMP
319 def_bool y
320 depends on X86_32 && SMP
321
322config X86_64_SMP
323 def_bool y
324 depends on X86_64 && SMP
325
ccbeed3a
TH
326config X86_32_LAZY_GS
327 def_bool y
2bc2f688 328 depends on X86_32 && CC_STACKPROTECTOR_NONE
ccbeed3a 329
2b144498
SD
330config ARCH_SUPPORTS_UPROBES
331 def_bool y
332
d20642f0
RH
333config FIX_EARLYCON_MEM
334 def_bool y
335
98233368
KS
336config PGTABLE_LEVELS
337 int
77ef56e4 338 default 5 if X86_5LEVEL
98233368
KS
339 default 4 if X86_64
340 default 3 if X86_PAE
341 default 2
342
506f1d07 343source "init/Kconfig"
2a61f474
MY
344
345config CC_HAS_SANE_STACKPROTECTOR
346 bool
347 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
348 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
349 help
350 We have to make sure stack protector is unconditionally disabled if
351 the compiler produces broken code.
352
dc52ddc0 353source "kernel/Kconfig.freezer"
8d5fffb9 354
506f1d07
SR
355menu "Processor type and features"
356
5ee71535
RD
357config ZONE_DMA
358 bool "DMA memory allocation support" if EXPERT
359 default y
360 help
361 DMA memory allocation support allows devices with less than 32-bit
362 addressing to allocate within the first 16MB of address space.
363 Disable if no such devices will be used.
364
365 If unsure, say Y.
366
506f1d07
SR
367config SMP
368 bool "Symmetric multi-processing support"
369 ---help---
370 This enables support for systems with more than one CPU. If you have
4a474157
RG
371 a system with only one CPU, say N. If you have a system with more
372 than one CPU, say Y.
506f1d07 373
4a474157 374 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
375 machines, but will use only one CPU of a multiprocessor machine. If
376 you say Y here, the kernel will run on many, but not all,
4a474157 377 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
378 will run faster if you say N here.
379
380 Note that if you say Y here and choose architecture "586" or
381 "Pentium" under "Processor family", the kernel will not work on 486
382 architectures. Similarly, multiprocessor kernels for the "PPro"
383 architecture may not work on all Pentium based boards.
384
385 People using multiprocessor machines who say Y here should also say
386 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
387 Management" code will be disabled if you say Y here.
388
395cf969 389 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 390 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
506f1d07
SR
391 <http://www.tldp.org/docs.html#howto>.
392
393 If you don't know what to do here, say N.
394
9def39be
JT
395config X86_FEATURE_NAMES
396 bool "Processor feature human-readable names" if EMBEDDED
397 default y
398 ---help---
399 This option compiles in a table of x86 feature bits and corresponding
400 names. This is required to support /proc/cpuinfo and a few kernel
401 messages. You can disable this to save space, at the expense of
402 making those few kernel messages show numeric feature bits instead.
403
404 If in doubt, say Y.
405
06cd9a7d
YL
406config X86_X2APIC
407 bool "Support x2apic"
19e3d60d 408 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
409 ---help---
410 This enables x2apic support on CPUs that have this feature.
411
412 This allows 32-bit apic IDs (so it can support very large systems),
413 and accesses the local apic via MSRs not via mmio.
414
06cd9a7d
YL
415 If you don't know what to do here, say N.
416
6695c85b 417config X86_MPPARSE
6e87f9b7 418 bool "Enable MPS table" if ACPI || SFI
7a527688 419 default y
5ab74722 420 depends on X86_LOCAL_APIC
8f9ca475 421 ---help---
6695c85b
YL
422 For old smp systems that do not have proper acpi support. Newer systems
423 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 424
ddd70cf9
JN
425config GOLDFISH
426 def_bool y
427 depends on X86_GOLDFISH
428
76b04384
DW
429config RETPOLINE
430 bool "Avoid speculative indirect branches in kernel"
431 default y
d5028ba8 432 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
433 help
434 Compile kernel with the retpoline compiler options to guard against
435 kernel-to-user data leaks by avoiding speculative indirect
436 branches. Requires a compiler with -mindirect-branch=thunk-extern
437 support for full protection. The kernel may run slower.
438
439 Without compiler support, at least indirect branches in assembler
440 code are eliminated. Since this includes the syscall entry path,
441 it is not entirely pointless.
442
f01d7d51
VS
443config INTEL_RDT
444 bool "Intel Resource Director Technology support"
78e99b4a
FY
445 default n
446 depends on X86 && CPU_SUP_INTEL
59fe5a77 447 select KERNFS
78e99b4a 448 help
f01d7d51
VS
449 Select to enable resource allocation and monitoring which are
450 sub-features of Intel Resource Director Technology(RDT). More
451 information about RDT can be found in the Intel x86
452 Architecture Software Developer Manual.
78e99b4a
FY
453
454 Say N if unsure.
455
8425091f 456if X86_32
a0d0bb4d
RD
457config X86_BIGSMP
458 bool "Support for big SMP systems with more than 8 CPUs"
459 depends on SMP
460 ---help---
461 This option is needed for the systems that have more than 8 CPUs
462
c5c606d9
RT
463config X86_EXTENDED_PLATFORM
464 bool "Support for extended (non-PC) x86 platforms"
465 default y
8f9ca475 466 ---help---
06ac8346
IM
467 If you disable this option then the kernel will only support
468 standard PC platforms. (which covers the vast majority of
469 systems out there.)
470
8425091f
RT
471 If you enable this option then you'll be able to select support
472 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 473 Goldfish (Android emulator)
8425091f 474 AMD Elan
8425091f
RT
475 RDC R-321x SoC
476 SGI 320/540 (Visual Workstation)
83125a3a 477 STA2X11-based (e.g. Northville)
3f4110a4 478 Moorestown MID devices
06ac8346
IM
479
480 If you have one of these systems, or if you want to build a
481 generic distribution kernel, say Y here - otherwise say N.
8425091f 482endif
06ac8346 483
8425091f
RT
484if X86_64
485config X86_EXTENDED_PLATFORM
486 bool "Support for extended (non-PC) x86 platforms"
487 default y
488 ---help---
489 If you disable this option then the kernel will only support
490 standard PC platforms. (which covers the vast majority of
491 systems out there.)
492
493 If you enable this option then you'll be able to select support
494 for the following (non-PC) 64 bit x86 platforms:
44b111b5 495 Numascale NumaChip
8425091f
RT
496 ScaleMP vSMP
497 SGI Ultraviolet
498
499 If you have one of these systems, or if you want to build a
500 generic distribution kernel, say Y here - otherwise say N.
501endif
c5c606d9
RT
502# This is an alphabetically sorted list of 64 bit extended platforms
503# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
504config X86_NUMACHIP
505 bool "Numascale NumaChip"
506 depends on X86_64
507 depends on X86_EXTENDED_PLATFORM
508 depends on NUMA
509 depends on SMP
510 depends on X86_X2APIC
f9726bfd 511 depends on PCI_MMCONFIG
44b111b5
SP
512 ---help---
513 Adds support for Numascale NumaChip large-SMP systems. Needed to
514 enable more than ~168 cores.
515 If you don't have one of these, you should say N here.
506f1d07 516
c5c606d9
RT
517config X86_VSMP
518 bool "ScaleMP vSMP"
6276a074 519 select HYPERVISOR_GUEST
c5c606d9
RT
520 select PARAVIRT
521 depends on X86_64 && PCI
522 depends on X86_EXTENDED_PLATFORM
ead91d4b 523 depends on SMP
8f9ca475 524 ---help---
c5c606d9
RT
525 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
526 supposed to run on these EM64T-based machines. Only choose this option
527 if you have one of these machines.
5e3a77e9 528
03b48632
NP
529config X86_UV
530 bool "SGI Ultraviolet"
531 depends on X86_64
c5c606d9 532 depends on X86_EXTENDED_PLATFORM
54c28d29 533 depends on NUMA
1ecb4ae5 534 depends on EFI
9d6c26e7 535 depends on X86_X2APIC
1222e564 536 depends on PCI
8f9ca475 537 ---help---
03b48632
NP
538 This option is needed in order to support SGI Ultraviolet systems.
539 If you don't have one of these, you should say N here.
540
c5c606d9
RT
541# Following is an alphabetically sorted list of 32 bit extended platforms
542# Please maintain the alphabetic order if and when there are additions
506f1d07 543
ddd70cf9
JN
544config X86_GOLDFISH
545 bool "Goldfish (Virtual Platform)"
cb7b8023 546 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
547 ---help---
548 Enable support for the Goldfish virtual platform used primarily
549 for Android development. Unless you are building for the Android
550 Goldfish emulator say N here.
551
c751e17b
TG
552config X86_INTEL_CE
553 bool "CE4100 TV platform"
554 depends on PCI
555 depends on PCI_GODIRECT
6084a6e2 556 depends on X86_IO_APIC
c751e17b
TG
557 depends on X86_32
558 depends on X86_EXTENDED_PLATFORM
37bc9f50 559 select X86_REBOOTFIXUPS
da6b737b
SAS
560 select OF
561 select OF_EARLY_FLATTREE
c751e17b
TG
562 ---help---
563 Select for the Intel CE media processor (CE4100) SOC.
564 This option compiles in support for the CE4100 SOC for settop
565 boxes and media devices.
566
4cb9b00f 567config X86_INTEL_MID
43605ef1 568 bool "Intel MID platform support"
43605ef1 569 depends on X86_EXTENDED_PLATFORM
edc6bc78 570 depends on X86_PLATFORM_DEVICES
1ea7c673 571 depends on PCI
3fda5bb4 572 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 573 depends on X86_IO_APIC
7c9c3a1e 574 select SFI
4cb9b00f 575 select I2C
7c9c3a1e 576 select DW_APB_TIMER
1ea7c673 577 select APB_TIMER
1ea7c673 578 select INTEL_SCU_IPC
15a713df 579 select MFD_INTEL_MSIC
1ea7c673 580 ---help---
4cb9b00f
DC
581 Select to build a kernel capable of supporting Intel MID (Mobile
582 Internet Device) platform systems which do not have the PCI legacy
583 interfaces. If you are building for a PC class system say N here.
1ea7c673 584
4cb9b00f
DC
585 Intel MID platforms are based on an Intel processor and chipset which
586 consume less power than most of the x86 derivatives.
43605ef1 587
8bbc2a13
BD
588config X86_INTEL_QUARK
589 bool "Intel Quark platform support"
590 depends on X86_32
591 depends on X86_EXTENDED_PLATFORM
592 depends on X86_PLATFORM_DEVICES
593 depends on X86_TSC
594 depends on PCI
595 depends on PCI_GOANY
596 depends on X86_IO_APIC
597 select IOSF_MBI
598 select INTEL_IMR
9ab6eb51 599 select COMMON_CLK
8bbc2a13
BD
600 ---help---
601 Select to include support for Quark X1000 SoC.
602 Say Y here if you have a Quark based system such as the Arduino
603 compatible Intel Galileo.
604
3d48aab1
MW
605config X86_INTEL_LPSS
606 bool "Intel Low Power Subsystem Support"
eebb3e8d 607 depends on X86 && ACPI
3d48aab1 608 select COMMON_CLK
0f531431 609 select PINCTRL
eebb3e8d 610 select IOSF_MBI
3d48aab1
MW
611 ---help---
612 Select to build support for Intel Low Power Subsystem such as
613 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
614 things like clock tree (common clock framework) and pincontrol
615 which are needed by the LPSS peripheral drivers.
3d48aab1 616
92082a88
KX
617config X86_AMD_PLATFORM_DEVICE
618 bool "AMD ACPI2Platform devices support"
619 depends on ACPI
620 select COMMON_CLK
621 select PINCTRL
622 ---help---
623 Select to interpret AMD specific ACPI device to platform device
624 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
625 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
626 implemented under PINCTRL subsystem.
627
ced3ce76
DB
628config IOSF_MBI
629 tristate "Intel SoC IOSF Sideband support for SoC platforms"
630 depends on PCI
631 ---help---
632 This option enables sideband register access support for Intel SoC
633 platforms. On these platforms the IOSF sideband is used in lieu of
634 MSR's for some register accesses, mostly but not limited to thermal
635 and power. Drivers may query the availability of this device to
636 determine if they need the sideband in order to work on these
637 platforms. The sideband is available on the following SoC products.
638 This list is not meant to be exclusive.
639 - BayTrail
640 - Braswell
641 - Quark
642
643 You should say Y if you are running a kernel on one of these SoC's.
644
ed2226bd
DB
645config IOSF_MBI_DEBUG
646 bool "Enable IOSF sideband access through debugfs"
647 depends on IOSF_MBI && DEBUG_FS
648 ---help---
649 Select this option to expose the IOSF sideband access registers (MCR,
650 MDR, MCRX) through debugfs to write and read register information from
651 different units on the SoC. This is most useful for obtaining device
652 state information for debug and analysis. As this is a general access
653 mechanism, users of this option would have specific knowledge of the
654 device they want to access.
655
656 If you don't require the option or are in doubt, say N.
657
c5c606d9
RT
658config X86_RDC321X
659 bool "RDC R-321x SoC"
506f1d07 660 depends on X86_32
c5c606d9
RT
661 depends on X86_EXTENDED_PLATFORM
662 select M486
663 select X86_REBOOTFIXUPS
664 ---help---
665 This option is needed for RDC R-321x system-on-chip, also known
666 as R-8610-(G).
667 If you don't have one of these chips, you should say N here.
668
e0c7ae37 669config X86_32_NON_STANDARD
9c398017
IM
670 bool "Support non-standard 32-bit SMP architectures"
671 depends on X86_32 && SMP
c5c606d9 672 depends on X86_EXTENDED_PLATFORM
8f9ca475 673 ---help---
b5660ba7
PA
674 This option compiles in the bigsmp and STA2X11 default
675 subarchitectures. It is intended for a generic binary
676 kernel. If you select them all, kernel will probe it one by
677 one and will fallback to default.
d49c4288 678
c5c606d9 679# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 680
d949f36f 681config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 682 def_bool y
d949f36f
LT
683 # MCE code calls memory_failure():
684 depends on X86_MCE
685 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
686 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
687 depends on X86_64 || !SPARSEMEM
688 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 689
83125a3a
AR
690config STA2X11
691 bool "STA2X11 Companion Chip Support"
692 depends on X86_32_NON_STANDARD && PCI
b6e05477 693 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
694 select X86_DEV_DMA_OPS
695 select X86_DMA_REMAP
696 select SWIOTLB
697 select MFD_STA2X11
0145071b 698 select GPIOLIB
83125a3a
AR
699 default n
700 ---help---
701 This adds support for boards based on the STA2X11 IO-Hub,
702 a.k.a. "ConneXt". The chip is used in place of the standard
703 PC chipset, so all "standard" peripherals are missing. If this
704 option is selected the kernel will still be able to boot on
705 standard PC machines.
706
82148d1d
S
707config X86_32_IRIS
708 tristate "Eurobraille/Iris poweroff module"
709 depends on X86_32
710 ---help---
711 The Iris machines from EuroBraille do not have APM or ACPI support
712 to shut themselves down properly. A special I/O sequence is
713 needed to do so, which is what this module does at
714 kernel shutdown.
715
716 This is only for Iris machines from EuroBraille.
717
718 If unused, say N.
719
ae1e9130 720config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
721 def_bool y
722 prompt "Single-depth WCHAN output"
a87d0914 723 depends on X86
8f9ca475 724 ---help---
506f1d07
SR
725 Calculate simpler /proc/<PID>/wchan values. If this option
726 is disabled then wchan values will recurse back to the
727 caller function. This provides more accurate wchan values,
728 at the expense of slightly more scheduling overhead.
729
730 If in doubt, say "Y".
731
6276a074
BP
732menuconfig HYPERVISOR_GUEST
733 bool "Linux guest support"
8f9ca475 734 ---help---
6276a074
BP
735 Say Y here to enable options for running Linux under various hyper-
736 visors. This option enables basic hypervisor detection and platform
737 setup.
506f1d07 738
6276a074
BP
739 If you say N, all options in this submenu will be skipped and
740 disabled, and Linux guest support won't be built in.
506f1d07 741
6276a074 742if HYPERVISOR_GUEST
506f1d07 743
e61bd94a
EPH
744config PARAVIRT
745 bool "Enable paravirtualization code"
8f9ca475 746 ---help---
e61bd94a
EPH
747 This changes the kernel so it can modify itself when it is run
748 under a hypervisor, potentially improving performance significantly
749 over full virtualization. However, when run without a hypervisor
750 the kernel is theoretically slower and slightly larger.
751
6276a074
BP
752config PARAVIRT_DEBUG
753 bool "paravirt-ops debugging"
754 depends on PARAVIRT && DEBUG_KERNEL
755 ---help---
756 Enable to debug paravirt_ops internals. Specifically, BUG if
757 a paravirt_op is missing when it is called.
758
b4ecc126
JF
759config PARAVIRT_SPINLOCKS
760 bool "Paravirtualization layer for spinlocks"
6ea30386 761 depends on PARAVIRT && SMP
b4ecc126
JF
762 ---help---
763 Paravirtualized spinlocks allow a pvops backend to replace the
764 spinlock implementation with something virtualization-friendly
765 (for example, block the virtual CPU rather than spinning).
766
4c4e4f61
R
767 It has a minimal impact on native kernels and gives a nice performance
768 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 769
4c4e4f61 770 If you are unsure how to answer this question, answer Y.
b4ecc126 771
45e898b7
WL
772config QUEUED_LOCK_STAT
773 bool "Paravirt queued spinlock statistics"
cfd8983f 774 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
775 ---help---
776 Enable the collection of statistical data on the slowpath
777 behavior of paravirtualized queued spinlocks and report
778 them on debugfs.
779
6276a074 780source "arch/x86/xen/Kconfig"
7af192c9 781
6276a074
BP
782config KVM_GUEST
783 bool "KVM Guest support (including kvmclock)"
784 depends on PARAVIRT
785 select PARAVIRT_CLOCK
786 default y
8f9ca475 787 ---help---
6276a074
BP
788 This option enables various optimizations for running under the KVM
789 hypervisor. It includes a paravirtualized clock, so that instead
790 of relying on a PIT (or probably other) emulation by the
791 underlying device model, the host provides the guest with
792 timing infrastructure such as time of day, and system time
506f1d07 793
1e20eb85
SV
794config KVM_DEBUG_FS
795 bool "Enable debug information for KVM Guests in debugfs"
796 depends on KVM_GUEST && DEBUG_FS
797 default n
798 ---help---
799 This option enables collection of various statistics for KVM guest.
800 Statistics are displayed in debugfs filesystem. Enabling this option
801 may incur significant overhead.
802
6276a074
BP
803config PARAVIRT_TIME_ACCOUNTING
804 bool "Paravirtual steal time accounting"
805 depends on PARAVIRT
806 default n
8f9ca475 807 ---help---
6276a074
BP
808 Select this option to enable fine granularity task steal time
809 accounting. Time spent executing other tasks in parallel with
810 the current vCPU is discounted from the vCPU power. To account for
811 that, there can be a small performance impact.
812
813 If in doubt, say N here.
814
815config PARAVIRT_CLOCK
816 bool
97349135 817
4a362601
JK
818config JAILHOUSE_GUEST
819 bool "Jailhouse non-root cell support"
abde587b 820 depends on X86_64 && PCI
87e65d05 821 select X86_PM_TIMER
4a362601
JK
822 ---help---
823 This option allows to run Linux as guest in a Jailhouse non-root
824 cell. You can leave this option disabled if you only want to start
825 Jailhouse and run Linux afterwards in the root cell.
826
6276a074 827endif #HYPERVISOR_GUEST
97349135 828
08677214 829config NO_BOOTMEM
774ea0bc 830 def_bool y
08677214 831
506f1d07
SR
832source "arch/x86/Kconfig.cpu"
833
834config HPET_TIMER
3c2362e6 835 def_bool X86_64
506f1d07 836 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
837 ---help---
838 Use the IA-PC HPET (High Precision Event Timer) to manage
839 time in preference to the PIT and RTC, if a HPET is
840 present.
841 HPET is the next generation timer replacing legacy 8254s.
842 The HPET provides a stable time base on SMP
843 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
844 as it is off-chip. The interface used is documented
845 in the HPET spec, revision 1.
506f1d07 846
8f9ca475
IM
847 You can safely choose Y here. However, HPET will only be
848 activated if the platform and the BIOS support this feature.
849 Otherwise the 8254 will be used for timing services.
506f1d07 850
8f9ca475 851 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
852
853config HPET_EMULATE_RTC
3c2362e6 854 def_bool y
9d8af78b 855 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 856
bb24c471 857config APB_TIMER
933b9463
AC
858 def_bool y if X86_INTEL_MID
859 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 860 select DW_APB_TIMER
a0c3832a 861 depends on X86_INTEL_MID && SFI
bb24c471
JP
862 help
863 APB timer is the replacement for 8254, HPET on X86 MID platforms.
864 The APBT provides a stable time base on SMP
865 systems, unlike the TSC, but it is more expensive to access,
866 as it is off-chip. APB timers are always running regardless of CPU
867 C states, they are used as per CPU clockevent device when possible.
868
6a108a14 869# Mark as expert because too many people got it wrong.
506f1d07 870# The code disables itself when not needed.
7ae9392c
TP
871config DMI
872 default y
cf074402 873 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 874 bool "Enable DMI scanning" if EXPERT
8f9ca475 875 ---help---
7ae9392c
TP
876 Enabled scanning of DMI to identify machine quirks. Say Y
877 here unless you have verified that your setup is not
878 affected by entries in the DMI blacklist. Required by PNP
879 BIOS code.
880
506f1d07 881config GART_IOMMU
38901f1c 882 bool "Old AMD GART IOMMU support"
a4ce5a48 883 select IOMMU_HELPER
506f1d07 884 select SWIOTLB
23ac4ae8 885 depends on X86_64 && PCI && AMD_NB
8f9ca475 886 ---help---
ced3c42c
IM
887 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
888 GART based hardware IOMMUs.
889
890 The GART supports full DMA access for devices with 32-bit access
891 limitations, on systems with more than 3 GB. This is usually needed
892 for USB, sound, many IDE/SATA chipsets and some other devices.
893
894 Newer systems typically have a modern AMD IOMMU, supported via
895 the CONFIG_AMD_IOMMU=y config option.
896
897 In normal configurations this driver is only active when needed:
898 there's more than 3 GB of memory and the system contains a
899 32-bit limited device.
900
901 If unsure, say Y.
506f1d07
SR
902
903config CALGARY_IOMMU
904 bool "IBM Calgary IOMMU support"
a4ce5a48 905 select IOMMU_HELPER
506f1d07 906 select SWIOTLB
6ea30386 907 depends on X86_64 && PCI
8f9ca475 908 ---help---
506f1d07
SR
909 Support for hardware IOMMUs in IBM's xSeries x366 and x460
910 systems. Needed to run systems with more than 3GB of memory
911 properly with 32-bit PCI devices that do not support DAC
912 (Double Address Cycle). Calgary also supports bus level
913 isolation, where all DMAs pass through the IOMMU. This
914 prevents them from going anywhere except their intended
915 destination. This catches hard-to-find kernel bugs and
916 mis-behaving drivers and devices that do not use the DMA-API
917 properly to set up their DMA buffers. The IOMMU can be
918 turned off at boot time with the iommu=off parameter.
919 Normally the kernel will make the right choice by itself.
920 If unsure, say Y.
921
922config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
923 def_bool y
924 prompt "Should Calgary be enabled by default?"
506f1d07 925 depends on CALGARY_IOMMU
8f9ca475 926 ---help---
506f1d07
SR
927 Should Calgary be enabled by default? if you choose 'y', Calgary
928 will be used (if it exists). If you choose 'n', Calgary will not be
929 used even if it exists. If you choose 'n' and would like to use
930 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
931 If unsure, say Y.
506f1d07 932
1184dc2f 933config MAXSMP
ddb0c5a6 934 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 935 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 936 select CPUMASK_OFFSTACK
8f9ca475 937 ---help---
ddb0c5a6 938 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 939 If unsure, say N.
506f1d07 940
aec6487e
IM
941#
942# The maximum number of CPUs supported:
943#
944# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
945# and which can be configured interactively in the
946# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
947#
948# The ranges are different on 32-bit and 64-bit kernels, depending on
949# hardware capabilities and scalability features of the kernel.
950#
951# ( If MAXSMP is enabled we just use the highest possible value and disable
952# interactive configuration. )
953#
954
955config NR_CPUS_RANGE_BEGIN
a0d0bb4d 956 int
aec6487e
IM
957 default NR_CPUS_RANGE_END if MAXSMP
958 default 1 if !SMP
959 default 2
a0d0bb4d 960
aec6487e 961config NR_CPUS_RANGE_END
a0d0bb4d 962 int
aec6487e
IM
963 depends on X86_32
964 default 64 if SMP && X86_BIGSMP
965 default 8 if SMP && !X86_BIGSMP
966 default 1 if !SMP
a0d0bb4d 967
aec6487e 968config NR_CPUS_RANGE_END
a0d0bb4d 969 int
aec6487e
IM
970 depends on X86_64
971 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
972 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
973 default 1 if !SMP
a0d0bb4d 974
aec6487e 975config NR_CPUS_DEFAULT
a0d0bb4d
RD
976 int
977 depends on X86_32
aec6487e
IM
978 default 32 if X86_BIGSMP
979 default 8 if SMP
980 default 1 if !SMP
a0d0bb4d 981
aec6487e 982config NR_CPUS_DEFAULT
a0d0bb4d
RD
983 int
984 depends on X86_64
aec6487e
IM
985 default 8192 if MAXSMP
986 default 64 if SMP
987 default 1 if !SMP
a0d0bb4d 988
506f1d07 989config NR_CPUS
36f5101a 990 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
991 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
992 default NR_CPUS_DEFAULT
8f9ca475 993 ---help---
506f1d07 994 This allows you to specify the maximum number of CPUs which this
bb61ccc7 995 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 996 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
997 minimum value which makes sense is 2.
998
aec6487e
IM
999 This is purely to save memory: each supported CPU adds about 8KB
1000 to the kernel image.
506f1d07
SR
1001
1002config SCHED_SMT
1003 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 1004 depends on SMP
8f9ca475 1005 ---help---
506f1d07
SR
1006 SMT scheduler support improves the CPU scheduler's decision making
1007 when dealing with Intel Pentium 4 chips with HyperThreading at a
1008 cost of slightly increased overhead in some places. If unsure say
1009 N here.
1010
1011config SCHED_MC
3c2362e6
HH
1012 def_bool y
1013 prompt "Multi-core scheduler support"
c8e56d20 1014 depends on SMP
8f9ca475 1015 ---help---
506f1d07
SR
1016 Multi-core scheduler support improves the CPU scheduler's decision
1017 making when dealing with multi-core CPU chips at a cost of slightly
1018 increased overhead in some places. If unsure say N here.
1019
de966cf4
TC
1020config SCHED_MC_PRIO
1021 bool "CPU core priorities scheduler support"
0a21fc12
IM
1022 depends on SCHED_MC && CPU_SUP_INTEL
1023 select X86_INTEL_PSTATE
1024 select CPU_FREQ
de966cf4 1025 default y
5e76b2ab 1026 ---help---
0a21fc12
IM
1027 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1028 core ordering determined at manufacturing time, which allows
1029 certain cores to reach higher turbo frequencies (when running
1030 single threaded workloads) than others.
de966cf4 1031
0a21fc12
IM
1032 Enabling this kernel feature teaches the scheduler about
1033 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1034 scheduler's CPU selection logic accordingly, so that higher
1035 overall system performance can be achieved.
de966cf4 1036
0a21fc12 1037 This feature will have no effect on CPUs without this feature.
de966cf4 1038
0a21fc12 1039 If unsure say Y here.
5e76b2ab 1040
506f1d07
SR
1041source "kernel/Kconfig.preempt"
1042
30b8b006
TG
1043config UP_LATE_INIT
1044 def_bool y
ba360f88 1045 depends on !SMP && X86_LOCAL_APIC
30b8b006 1046
506f1d07 1047config X86_UP_APIC
50849eef
JB
1048 bool "Local APIC support on uniprocessors" if !PCI_MSI
1049 default PCI_MSI
38a1dfda 1050 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1051 ---help---
506f1d07
SR
1052 A local APIC (Advanced Programmable Interrupt Controller) is an
1053 integrated interrupt controller in the CPU. If you have a single-CPU
1054 system which has a processor with a local APIC, you can say Y here to
1055 enable and use it. If you say Y here even though your machine doesn't
1056 have a local APIC, then the kernel will still run with no slowdown at
1057 all. The local APIC supports CPU-generated self-interrupts (timer,
1058 performance counters), and the NMI watchdog which detects hard
1059 lockups.
1060
1061config X86_UP_IOAPIC
1062 bool "IO-APIC support on uniprocessors"
1063 depends on X86_UP_APIC
8f9ca475 1064 ---help---
506f1d07
SR
1065 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1066 SMP-capable replacement for PC-style interrupt controllers. Most
1067 SMP systems and many recent uniprocessor systems have one.
1068
1069 If you have a single-CPU system with an IO-APIC, you can say Y here
1070 to use it. If you say Y here even though your machine doesn't have
1071 an IO-APIC, then the kernel will still run with no slowdown at all.
1072
1073config X86_LOCAL_APIC
3c2362e6 1074 def_bool y
0dbc6078 1075 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1076 select IRQ_DOMAIN_HIERARCHY
52f518a3 1077 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1078
1079config X86_IO_APIC
b1da1e71
JB
1080 def_bool y
1081 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1082
41b9eb26
SA
1083config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1084 bool "Reroute for broken boot IRQs"
41b9eb26 1085 depends on X86_IO_APIC
8f9ca475 1086 ---help---
41b9eb26
SA
1087 This option enables a workaround that fixes a source of
1088 spurious interrupts. This is recommended when threaded
1089 interrupt handling is used on systems where the generation of
1090 superfluous "boot interrupts" cannot be disabled.
1091
1092 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1093 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1094 kernel does during interrupt handling). On chipsets where this
1095 boot IRQ generation cannot be disabled, this workaround keeps
1096 the original IRQ line masked so that only the equivalent "boot
1097 IRQ" is delivered to the CPUs. The workaround also tells the
1098 kernel to set up the IRQ handler on the boot IRQ line. In this
1099 way only one interrupt is delivered to the kernel. Otherwise
1100 the spurious second interrupt may cause the kernel to bring
1101 down (vital) interrupt lines.
1102
1103 Only affects "broken" chipsets. Interrupt sharing may be
1104 increased on these systems.
1105
506f1d07 1106config X86_MCE
bab9bc65 1107 bool "Machine Check / overheating reporting"
648ed940 1108 select GENERIC_ALLOCATOR
e57dbaf7 1109 default y
506f1d07 1110 ---help---
bab9bc65
AK
1111 Machine Check support allows the processor to notify the
1112 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1113 The action the kernel takes depends on the severity of the problem,
bab9bc65 1114 ranging from warning messages to halting the machine.
4efc0670 1115
5de97c9f
TL
1116config X86_MCELOG_LEGACY
1117 bool "Support for deprecated /dev/mcelog character device"
1118 depends on X86_MCE
1119 ---help---
1120 Enable support for /dev/mcelog which is needed by the old mcelog
1121 userspace logging daemon. Consider switching to the new generation
1122 rasdaemon solution.
1123
506f1d07 1124config X86_MCE_INTEL
3c2362e6
HH
1125 def_bool y
1126 prompt "Intel MCE features"
c1ebf835 1127 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1128 ---help---
506f1d07
SR
1129 Additional support for intel specific MCE features such as
1130 the thermal monitor.
1131
1132config X86_MCE_AMD
3c2362e6
HH
1133 def_bool y
1134 prompt "AMD MCE features"
f5382de9 1135 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1136 ---help---
506f1d07
SR
1137 Additional support for AMD specific MCE features such as
1138 the DRAM Error Threshold.
1139
4efc0670 1140config X86_ANCIENT_MCE
6fc108a0 1141 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1142 depends on X86_32 && X86_MCE
cd13adcc
HS
1143 ---help---
1144 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1145 systems. These typically need to be enabled explicitly on the command
cd13adcc 1146 line.
4efc0670 1147
b2762686
AK
1148config X86_MCE_THRESHOLD
1149 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1150 def_bool y
b2762686 1151
ea149b36 1152config X86_MCE_INJECT
bc8e80d5 1153 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1154 tristate "Machine check injector support"
1155 ---help---
1156 Provide support for injecting machine checks for testing purposes.
1157 If you don't know what a machine check is and you don't do kernel
1158 QA it is safe to say n.
1159
4efc0670
AK
1160config X86_THERMAL_VECTOR
1161 def_bool y
5bb38adc 1162 depends on X86_MCE_INTEL
4efc0670 1163
07dc900e 1164source "arch/x86/events/Kconfig"
e633c65a 1165
5aef51c3 1166config X86_LEGACY_VM86
1e642812 1167 bool "Legacy VM86 support"
5aef51c3 1168 default n
506f1d07 1169 depends on X86_32
8f9ca475 1170 ---help---
5aef51c3
AL
1171 This option allows user programs to put the CPU into V8086
1172 mode, which is an 80286-era approximation of 16-bit real mode.
1173
1174 Some very old versions of X and/or vbetool require this option
1175 for user mode setting. Similarly, DOSEMU will use it if
1176 available to accelerate real mode DOS programs. However, any
1177 recent version of DOSEMU, X, or vbetool should be fully
1178 functional even without kernel VM86 support, as they will all
1e642812
IM
1179 fall back to software emulation. Nevertheless, if you are using
1180 a 16-bit DOS program where 16-bit performance matters, vm86
1181 mode might be faster than emulation and you might want to
1182 enable this option.
5aef51c3 1183
1e642812
IM
1184 Note that any app that works on a 64-bit kernel is unlikely to
1185 need this option, as 64-bit kernels don't, and can't, support
1186 V8086 mode. This option is also unrelated to 16-bit protected
1187 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1188
1e642812
IM
1189 Enabling this option increases the complexity of the kernel
1190 and slows down exception handling a tiny bit.
5aef51c3 1191
1e642812 1192 If unsure, say N here.
5aef51c3
AL
1193
1194config VM86
1195 bool
1196 default X86_LEGACY_VM86
34273f41
PA
1197
1198config X86_16BIT
1199 bool "Enable support for 16-bit segments" if EXPERT
1200 default y
a5b9e5a2 1201 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1202 ---help---
1203 This option is required by programs like Wine to run 16-bit
1204 protected mode legacy code on x86 processors. Disabling
1205 this option saves about 300 bytes on i386, or around 6K text
1206 plus 16K runtime memory on x86-64,
1207
1208config X86_ESPFIX32
1209 def_bool y
1210 depends on X86_16BIT && X86_32
506f1d07 1211
197725de
PA
1212config X86_ESPFIX64
1213 def_bool y
34273f41 1214 depends on X86_16BIT && X86_64
506f1d07 1215
1ad83c85
AL
1216config X86_VSYSCALL_EMULATION
1217 bool "Enable vsyscall emulation" if EXPERT
1218 default y
1219 depends on X86_64
1220 ---help---
1221 This enables emulation of the legacy vsyscall page. Disabling
1222 it is roughly equivalent to booting with vsyscall=none, except
1223 that it will also disable the helpful warning if a program
1224 tries to use a vsyscall. With this option set to N, offending
1225 programs will just segfault, citing addresses of the form
1226 0xffffffffff600?00.
1227
1228 This option is required by many programs built before 2013, and
1229 care should be used even with newer programs if set to N.
1230
1231 Disabling this option saves about 7K of kernel size and
1232 possibly 4K of additional runtime pagetable memory.
1233
506f1d07
SR
1234config TOSHIBA
1235 tristate "Toshiba Laptop support"
1236 depends on X86_32
1237 ---help---
1238 This adds a driver to safely access the System Management Mode of
1239 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1240 not work on models with a Phoenix BIOS. The System Management Mode
1241 is used to set the BIOS and power saving options on Toshiba portables.
1242
1243 For information on utilities to make use of this driver see the
1244 Toshiba Linux utilities web site at:
1245 <http://www.buzzard.org.uk/toshiba/>.
1246
1247 Say Y if you intend to run this kernel on a Toshiba portable.
1248 Say N otherwise.
1249
1250config I8K
039ae585 1251 tristate "Dell i8k legacy laptop support"
949a9d70 1252 select HWMON
039ae585 1253 select SENSORS_DELL_SMM
506f1d07 1254 ---help---
039ae585
PR
1255 This option enables legacy /proc/i8k userspace interface in hwmon
1256 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1257 temperature and allows controlling fan speeds of Dell laptops via
1258 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1259 it reports also power and hotkey status. For fan speed control is
1260 needed userspace package i8kutils.
1261
1262 Say Y if you intend to run this kernel on old Dell laptops or want to
1263 use userspace package i8kutils.
506f1d07
SR
1264 Say N otherwise.
1265
1266config X86_REBOOTFIXUPS
9ba16087
JB
1267 bool "Enable X86 board specific fixups for reboot"
1268 depends on X86_32
506f1d07
SR
1269 ---help---
1270 This enables chipset and/or board specific fixups to be done
1271 in order to get reboot to work correctly. This is only needed on
1272 some combinations of hardware and BIOS. The symptom, for which
1273 this config is intended, is when reboot ends with a stalled/hung
1274 system.
1275
1276 Currently, the only fixup is for the Geode machines using
5e3a77e9 1277 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1278
1279 Say Y if you want to enable the fixup. Currently, it's safe to
1280 enable this option even if you don't need it.
1281 Say N otherwise.
1282
1283config MICROCODE
9a2bc335
BP
1284 bool "CPU microcode loading support"
1285 default y
80030e3d 1286 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1287 select FW_LOADER
1288 ---help---
1289 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1290 Intel and AMD processors. The Intel support is for the IA32 family,
1291 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1292 AMD support is for families 0x10 and later. You will obviously need
1293 the actual microcode binary data itself which is not shipped with
1294 the Linux kernel.
1295
1296 The preferred method to load microcode from a detached initrd is described
1897a969 1297 in Documentation/x86/microcode.txt. For that you need to enable
5f9c01aa
BP
1298 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1299 initrd for microcode blobs.
1300
c508c46e
BG
1301 In addition, you can build the microcode into the kernel. For that you
1302 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1303 config option.
506f1d07 1304
8d86f390 1305config MICROCODE_INTEL
e43f6e67 1306 bool "Intel microcode loading support"
8f9ca475
IM
1307 depends on MICROCODE
1308 default MICROCODE
1309 select FW_LOADER
1310 ---help---
1311 This options enables microcode patch loading support for Intel
1312 processors.
1313
b8989db9
A
1314 For the current Intel microcode data package go to
1315 <https://downloadcenter.intel.com> and search for
1316 'Linux Processor Microcode Data File'.
8d86f390 1317
80cc9f10 1318config MICROCODE_AMD
e43f6e67 1319 bool "AMD microcode loading support"
8f9ca475
IM
1320 depends on MICROCODE
1321 select FW_LOADER
1322 ---help---
1323 If you select this option, microcode patch loading support for AMD
1324 processors will be enabled.
80cc9f10 1325
8f9ca475 1326config MICROCODE_OLD_INTERFACE
3c2362e6 1327 def_bool y
506f1d07 1328 depends on MICROCODE
506f1d07
SR
1329
1330config X86_MSR
1331 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1332 ---help---
506f1d07
SR
1333 This device gives privileged processes access to the x86
1334 Model-Specific Registers (MSRs). It is a character device with
1335 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1336 MSR accesses are directed to a specific CPU on multi-processor
1337 systems.
1338
1339config X86_CPUID
1340 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1341 ---help---
506f1d07
SR
1342 This device gives processes access to the x86 CPUID instruction to
1343 be executed on a specific processor. It is a character device
1344 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1345 /dev/cpu/31/cpuid.
1346
1347choice
1348 prompt "High Memory Support"
6fc108a0 1349 default HIGHMEM4G
506f1d07
SR
1350 depends on X86_32
1351
1352config NOHIGHMEM
1353 bool "off"
506f1d07
SR
1354 ---help---
1355 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1356 However, the address space of 32-bit x86 processors is only 4
1357 Gigabytes large. That means that, if you have a large amount of
1358 physical memory, not all of it can be "permanently mapped" by the
1359 kernel. The physical memory that's not permanently mapped is called
1360 "high memory".
1361
1362 If you are compiling a kernel which will never run on a machine with
1363 more than 1 Gigabyte total physical RAM, answer "off" here (default
1364 choice and suitable for most users). This will result in a "3GB/1GB"
1365 split: 3GB are mapped so that each process sees a 3GB virtual memory
1366 space and the remaining part of the 4GB virtual memory space is used
1367 by the kernel to permanently map as much physical memory as
1368 possible.
1369
1370 If the machine has between 1 and 4 Gigabytes physical RAM, then
1371 answer "4GB" here.
1372
1373 If more than 4 Gigabytes is used then answer "64GB" here. This
1374 selection turns Intel PAE (Physical Address Extension) mode on.
1375 PAE implements 3-level paging on IA32 processors. PAE is fully
1376 supported by Linux, PAE mode is implemented on all recent Intel
1377 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1378 then the kernel will not boot on CPUs that don't support PAE!
1379
1380 The actual amount of total physical memory will either be
1381 auto detected or can be forced by using a kernel command line option
1382 such as "mem=256M". (Try "man bootparam" or see the documentation of
1383 your boot loader (lilo or loadlin) about how to pass options to the
1384 kernel at boot time.)
1385
1386 If unsure, say "off".
1387
1388config HIGHMEM4G
1389 bool "4GB"
8f9ca475 1390 ---help---
506f1d07
SR
1391 Select this if you have a 32-bit processor and between 1 and 4
1392 gigabytes of physical RAM.
1393
1394config HIGHMEM64G
1395 bool "64GB"
69b8d3fc 1396 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1397 select X86_PAE
8f9ca475 1398 ---help---
506f1d07
SR
1399 Select this if you have a 32-bit processor and more than 4
1400 gigabytes of physical RAM.
1401
1402endchoice
1403
1404choice
6a108a14 1405 prompt "Memory split" if EXPERT
506f1d07
SR
1406 default VMSPLIT_3G
1407 depends on X86_32
8f9ca475 1408 ---help---
506f1d07
SR
1409 Select the desired split between kernel and user memory.
1410
1411 If the address range available to the kernel is less than the
1412 physical memory installed, the remaining memory will be available
1413 as "high memory". Accessing high memory is a little more costly
1414 than low memory, as it needs to be mapped into the kernel first.
1415 Note that increasing the kernel address space limits the range
1416 available to user programs, making the address space there
1417 tighter. Selecting anything other than the default 3G/1G split
1418 will also likely make your kernel incompatible with binary-only
1419 kernel modules.
1420
1421 If you are not absolutely sure what you are doing, leave this
1422 option alone!
1423
1424 config VMSPLIT_3G
1425 bool "3G/1G user/kernel split"
1426 config VMSPLIT_3G_OPT
1427 depends on !X86_PAE
1428 bool "3G/1G user/kernel split (for full 1G low memory)"
1429 config VMSPLIT_2G
1430 bool "2G/2G user/kernel split"
1431 config VMSPLIT_2G_OPT
1432 depends on !X86_PAE
1433 bool "2G/2G user/kernel split (for full 2G low memory)"
1434 config VMSPLIT_1G
1435 bool "1G/3G user/kernel split"
1436endchoice
1437
1438config PAGE_OFFSET
1439 hex
1440 default 0xB0000000 if VMSPLIT_3G_OPT
1441 default 0x80000000 if VMSPLIT_2G
1442 default 0x78000000 if VMSPLIT_2G_OPT
1443 default 0x40000000 if VMSPLIT_1G
1444 default 0xC0000000
1445 depends on X86_32
1446
1447config HIGHMEM
3c2362e6 1448 def_bool y
506f1d07 1449 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1450
1451config X86_PAE
9ba16087 1452 bool "PAE (Physical Address Extension) Support"
506f1d07 1453 depends on X86_32 && !HIGHMEM4G
d4a451d5 1454 select PHYS_ADDR_T_64BIT
9d99c712 1455 select SWIOTLB
8f9ca475 1456 ---help---
506f1d07
SR
1457 PAE is required for NX support, and furthermore enables
1458 larger swapspace support for non-overcommit purposes. It
1459 has the cost of more pagetable lookup overhead, and also
1460 consumes more pagetable space per process.
1461
77ef56e4
KS
1462config X86_5LEVEL
1463 bool "Enable 5-level page tables support"
eedb92ab 1464 select DYNAMIC_MEMORY_LAYOUT
162434e7 1465 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1466 depends on X86_64
1467 ---help---
1468 5-level paging enables access to larger address space:
1469 upto 128 PiB of virtual address space and 4 PiB of
1470 physical address space.
1471
1472 It will be supported by future Intel CPUs.
1473
6657fca0
KS
1474 A kernel with the option enabled can be booted on machines that
1475 support 4- or 5-level paging.
77ef56e4
KS
1476
1477 See Documentation/x86/x86_64/5level-paging.txt for more
1478 information.
1479
1480 Say N if unsure.
1481
10971ab2 1482config X86_DIRECT_GBPAGES
e5008abe 1483 def_bool y
4675ff05 1484 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1485 ---help---
10971ab2
IM
1486 Certain kernel features effectively disable kernel
1487 linear 1 GB mappings (even if the CPU otherwise
1488 supports them), so don't confuse the user by printing
1489 that we have them enabled.
9e899816 1490
7744ccdb
TL
1491config ARCH_HAS_MEM_ENCRYPT
1492 def_bool y
1493
1494config AMD_MEM_ENCRYPT
1495 bool "AMD Secure Memory Encryption (SME) support"
1496 depends on X86_64 && CPU_SUP_AMD
1497 ---help---
1498 Say yes to enable support for the encryption of system memory.
1499 This requires an AMD processor that supports Secure Memory
1500 Encryption (SME).
1501
1502config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1503 bool "Activate AMD Secure Memory Encryption (SME) by default"
1504 default y
1505 depends on AMD_MEM_ENCRYPT
1506 ---help---
1507 Say yes to have system memory encrypted by default if running on
1508 an AMD processor that supports Secure Memory Encryption (SME).
1509
1510 If set to Y, then the encryption of system memory can be
1511 deactivated with the mem_encrypt=off command line option.
1512
1513 If set to N, then the encryption of system memory can be
1514 activated with the mem_encrypt=on command line option.
1515
f88a68fa
TL
1516config ARCH_USE_MEMREMAP_PROT
1517 def_bool y
1518 depends on AMD_MEM_ENCRYPT
1519
506f1d07
SR
1520# Common NUMA Features
1521config NUMA
fd51b2d7 1522 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1523 depends on SMP
b5660ba7
PA
1524 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1525 default y if X86_BIGSMP
8f9ca475 1526 ---help---
506f1d07 1527 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1528
506f1d07
SR
1529 The kernel will try to allocate memory used by a CPU on the
1530 local memory controller of the CPU and add some more
1531 NUMA awareness to the kernel.
1532
c280ea5e 1533 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1534 (or later), AMD Opteron, or EM64T NUMA.
1535
b5660ba7 1536 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1537 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1538
1539 Otherwise, you should say N.
506f1d07 1540
eec1d4fa 1541config AMD_NUMA
3c2362e6
HH
1542 def_bool y
1543 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1544 depends on X86_64 && NUMA && PCI
8f9ca475 1545 ---help---
eec1d4fa
HR
1546 Enable AMD NUMA node topology detection. You should say Y here if
1547 you have a multi processor AMD system. This uses an old method to
1548 read the NUMA configuration directly from the builtin Northbridge
1549 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1550 which also takes priority if both are compiled in.
506f1d07
SR
1551
1552config X86_64_ACPI_NUMA
3c2362e6
HH
1553 def_bool y
1554 prompt "ACPI NUMA detection"
506f1d07
SR
1555 depends on X86_64 && NUMA && ACPI && PCI
1556 select ACPI_NUMA
8f9ca475 1557 ---help---
506f1d07
SR
1558 Enable ACPI SRAT based node topology detection.
1559
6ec6e0d9
SS
1560# Some NUMA nodes have memory ranges that span
1561# other nodes. Even though a pfn is valid and
1562# between a node's start and end pfns, it may not
1563# reside on that node. See memmap_init_zone()
1564# for details.
1565config NODES_SPAN_OTHER_NODES
1566 def_bool y
1567 depends on X86_64_ACPI_NUMA
1568
506f1d07
SR
1569config NUMA_EMU
1570 bool "NUMA emulation"
1b7e03ef 1571 depends on NUMA
8f9ca475 1572 ---help---
506f1d07
SR
1573 Enable NUMA emulation. A flat machine will be split
1574 into virtual nodes when booted with "numa=fake=N", where N is the
1575 number of nodes. This is only useful for debugging.
1576
1577config NODES_SHIFT
d25e26b6 1578 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1579 range 1 10
1580 default "10" if MAXSMP
506f1d07 1581 default "6" if X86_64
506f1d07
SR
1582 default "3"
1583 depends on NEED_MULTIPLE_NODES
8f9ca475 1584 ---help---
1184dc2f 1585 Specify the maximum number of NUMA Nodes available on the target
692105b8 1586 system. Increases memory reserved to accommodate various tables.
506f1d07 1587
506f1d07 1588config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1589 def_bool y
506f1d07 1590 depends on X86_32 && DISCONTIGMEM
506f1d07 1591
506f1d07
SR
1592config ARCH_FLATMEM_ENABLE
1593 def_bool y
3b16651f 1594 depends on X86_32 && !NUMA
506f1d07
SR
1595
1596config ARCH_DISCONTIGMEM_ENABLE
1597 def_bool y
b263295d 1598 depends on NUMA && X86_32
506f1d07
SR
1599
1600config ARCH_DISCONTIGMEM_DEFAULT
1601 def_bool y
b263295d
CL
1602 depends on NUMA && X86_32
1603
506f1d07
SR
1604config ARCH_SPARSEMEM_ENABLE
1605 def_bool y
6ea30386 1606 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1607 select SPARSEMEM_STATIC if X86_32
1608 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1609
3b16651f
TH
1610config ARCH_SPARSEMEM_DEFAULT
1611 def_bool y
1612 depends on X86_64
1613
506f1d07
SR
1614config ARCH_SELECT_MEMORY_MODEL
1615 def_bool y
b263295d 1616 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1617
1618config ARCH_MEMORY_PROBE
a0842b70 1619 bool "Enable sysfs memory/probe interface"
3120e25e 1620 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1621 help
1622 This option enables a sysfs memory/probe interface for testing.
1623 See Documentation/memory-hotplug.txt for more information.
1624 If you are unsure how to answer this question, answer N.
506f1d07 1625
3b16651f
TH
1626config ARCH_PROC_KCORE_TEXT
1627 def_bool y
1628 depends on X86_64 && PROC_KCORE
1629
a29815a3
AK
1630config ILLEGAL_POINTER_VALUE
1631 hex
1632 default 0 if X86_32
1633 default 0xdead000000000000 if X86_64
1634
506f1d07
SR
1635source "mm/Kconfig"
1636
7a67832c
DW
1637config X86_PMEM_LEGACY_DEVICE
1638 bool
1639
ec776ef6 1640config X86_PMEM_LEGACY
7a67832c 1641 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1642 depends on PHYS_ADDR_T_64BIT
1643 depends on BLK_DEV
7a67832c 1644 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1645 select LIBNVDIMM
ec776ef6
CH
1646 help
1647 Treat memory marked using the non-standard e820 type of 12 as used
1648 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1649 The kernel will offer these regions to the 'pmem' driver so
1650 they can be used for persistent storage.
1651
1652 Say Y if unsure.
1653
506f1d07
SR
1654config HIGHPTE
1655 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1656 depends on HIGHMEM
8f9ca475 1657 ---help---
506f1d07
SR
1658 The VM uses one page table entry for each page of physical memory.
1659 For systems with a lot of RAM, this can be wasteful of precious
1660 low memory. Setting this option will put user-space page table
1661 entries in high memory.
1662
9f077871 1663config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1664 bool "Check for low memory corruption"
1665 ---help---
1666 Periodically check for memory corruption in low memory, which
1667 is suspected to be caused by BIOS. Even when enabled in the
1668 configuration, it is disabled at runtime. Enable it by
1669 setting "memory_corruption_check=1" on the kernel command
1670 line. By default it scans the low 64k of memory every 60
1671 seconds; see the memory_corruption_check_size and
1672 memory_corruption_check_period parameters in
8c27ceff 1673 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1674
1675 When enabled with the default parameters, this option has
1676 almost no overhead, as it reserves a relatively small amount
1677 of memory and scans it infrequently. It both detects corruption
1678 and prevents it from affecting the running system.
1679
1680 It is, however, intended as a diagnostic tool; if repeatable
1681 BIOS-originated corruption always affects the same memory,
1682 you can use memmap= to prevent the kernel from using that
1683 memory.
9f077871 1684
c885df50 1685config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1686 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1687 depends on X86_CHECK_BIOS_CORRUPTION
1688 default y
8f9ca475
IM
1689 ---help---
1690 Set whether the default state of memory_corruption_check is
1691 on or off.
c885df50 1692
9ea77bdb 1693config X86_RESERVE_LOW
d0cd7425
PA
1694 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1695 default 64
1696 range 4 640
8f9ca475 1697 ---help---
d0cd7425
PA
1698 Specify the amount of low memory to reserve for the BIOS.
1699
1700 The first page contains BIOS data structures that the kernel
1701 must not use, so that page must always be reserved.
1702
1703 By default we reserve the first 64K of physical RAM, as a
1704 number of BIOSes are known to corrupt that memory range
1705 during events such as suspend/resume or monitor cable
1706 insertion, so it must not be used by the kernel.
fc381519 1707
d0cd7425
PA
1708 You can set this to 4 if you are absolutely sure that you
1709 trust the BIOS to get all its memory reservations and usages
1710 right. If you know your BIOS have problems beyond the
1711 default 64K area, you can set this to 640 to avoid using the
1712 entire low memory range.
fc381519 1713
d0cd7425
PA
1714 If you have doubts about the BIOS (e.g. suspend/resume does
1715 not work or there's kernel crashes after certain hardware
1716 hotplug events) then you might want to enable
1717 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1718 typical corruption patterns.
fc381519 1719
d0cd7425 1720 Leave this to the default value of 64 if you are unsure.
fc381519 1721
506f1d07
SR
1722config MATH_EMULATION
1723 bool
a5b9e5a2 1724 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1725 prompt "Math emulation" if X86_32
1726 ---help---
1727 Linux can emulate a math coprocessor (used for floating point
1728 operations) if you don't have one. 486DX and Pentium processors have
1729 a math coprocessor built in, 486SX and 386 do not, unless you added
1730 a 487DX or 387, respectively. (The messages during boot time can
1731 give you some hints here ["man dmesg"].) Everyone needs either a
1732 coprocessor or this emulation.
1733
1734 If you don't have a math coprocessor, you need to say Y here; if you
1735 say Y here even though you have a coprocessor, the coprocessor will
1736 be used nevertheless. (This behavior can be changed with the kernel
1737 command line option "no387", which comes handy if your coprocessor
1738 is broken. Try "man bootparam" or see the documentation of your boot
1739 loader (lilo or loadlin) about how to pass options to the kernel at
1740 boot time.) This means that it is a good idea to say Y here if you
1741 intend to use this kernel on different machines.
1742
1743 More information about the internals of the Linux math coprocessor
1744 emulation can be found in <file:arch/x86/math-emu/README>.
1745
1746 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1747 kernel, it won't hurt.
1748
1749config MTRR
6fc108a0 1750 def_bool y
6a108a14 1751 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1752 ---help---
1753 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1754 the Memory Type Range Registers (MTRRs) may be used to control
1755 processor access to memory ranges. This is most useful if you have
1756 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1757 allows bus write transfers to be combined into a larger transfer
1758 before bursting over the PCI/AGP bus. This can increase performance
1759 of image write operations 2.5 times or more. Saying Y here creates a
1760 /proc/mtrr file which may be used to manipulate your processor's
1761 MTRRs. Typically the X server should use this.
1762
1763 This code has a reasonably generic interface so that similar
1764 control registers on other processors can be easily supported
1765 as well:
1766
1767 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1768 Registers (ARRs) which provide a similar functionality to MTRRs. For
1769 these, the ARRs are used to emulate the MTRRs.
1770 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1771 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1772 write-combining. All of these processors are supported by this code
1773 and it makes sense to say Y here if you have one of them.
1774
1775 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1776 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1777 can lead to all sorts of problems, so it's good to say Y here.
1778
1779 You can safely say Y even if your machine doesn't have MTRRs, you'll
1780 just add about 9 KB to your kernel.
1781
7225e751 1782 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1783
95ffa243 1784config MTRR_SANITIZER
2ffb3501 1785 def_bool y
95ffa243
YL
1786 prompt "MTRR cleanup support"
1787 depends on MTRR
8f9ca475 1788 ---help---
aba3728c
TG
1789 Convert MTRR layout from continuous to discrete, so X drivers can
1790 add writeback entries.
95ffa243 1791
aba3728c 1792 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1793 The largest mtrr entry size for a continuous block can be set with
aba3728c 1794 mtrr_chunk_size.
95ffa243 1795
2ffb3501 1796 If unsure, say Y.
95ffa243
YL
1797
1798config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1799 int "MTRR cleanup enable value (0-1)"
1800 range 0 1
1801 default "0"
95ffa243 1802 depends on MTRR_SANITIZER
8f9ca475 1803 ---help---
f5098d62 1804 Enable mtrr cleanup default value
95ffa243 1805
12031a62
YL
1806config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1807 int "MTRR cleanup spare reg num (0-7)"
1808 range 0 7
1809 default "1"
1810 depends on MTRR_SANITIZER
8f9ca475 1811 ---help---
12031a62 1812 mtrr cleanup spare entries default, it can be changed via
aba3728c 1813 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1814
2e5d9c85 1815config X86_PAT
6fc108a0 1816 def_bool y
6a108a14 1817 prompt "x86 PAT support" if EXPERT
2a8a2719 1818 depends on MTRR
8f9ca475 1819 ---help---
2e5d9c85 1820 Use PAT attributes to setup page level cache control.
042b78e4 1821
2e5d9c85 1822 PATs are the modern equivalents of MTRRs and are much more
1823 flexible than MTRRs.
1824
1825 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1826 spontaneous reboots) or a non-working video driver.
2e5d9c85 1827
1828 If unsure, say Y.
1829
46cf98cd
VP
1830config ARCH_USES_PG_UNCACHED
1831 def_bool y
1832 depends on X86_PAT
1833
628c6246
PA
1834config ARCH_RANDOM
1835 def_bool y
1836 prompt "x86 architectural random number generator" if EXPERT
1837 ---help---
1838 Enable the x86 architectural RDRAND instruction
1839 (Intel Bull Mountain technology) to generate random numbers.
1840 If supported, this is a high bandwidth, cryptographically
1841 secure hardware random number generator.
1842
51ae4a2d
PA
1843config X86_SMAP
1844 def_bool y
1845 prompt "Supervisor Mode Access Prevention" if EXPERT
1846 ---help---
1847 Supervisor Mode Access Prevention (SMAP) is a security
1848 feature in newer Intel processors. There is a small
1849 performance cost if this enabled and turned on; there is
1850 also a small increase in the kernel size if this is enabled.
1851
1852 If unsure, say Y.
1853
aa35f896 1854config X86_INTEL_UMIP
796ebc81 1855 def_bool y
aa35f896
RN
1856 depends on CPU_SUP_INTEL
1857 prompt "Intel User Mode Instruction Prevention" if EXPERT
1858 ---help---
1859 The User Mode Instruction Prevention (UMIP) is a security
1860 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1861 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1862 or STR instructions are executed in user mode. These instructions
1863 unnecessarily expose information about the hardware state.
1864
1865 The vast majority of applications do not use these instructions.
1866 For the very few that do, software emulation is provided in
1867 specific cases in protected and virtual-8086 modes. Emulated
1868 results are dummy.
aa35f896 1869
72e9b5fe
DH
1870config X86_INTEL_MPX
1871 prompt "Intel MPX (Memory Protection Extensions)"
1872 def_bool n
df3735c5
RR
1873 # Note: only available in 64-bit mode due to VMA flags shortage
1874 depends on CPU_SUP_INTEL && X86_64
1875 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1876 ---help---
1877 MPX provides hardware features that can be used in
1878 conjunction with compiler-instrumented code to check
1879 memory references. It is designed to detect buffer
1880 overflow or underflow bugs.
1881
1882 This option enables running applications which are
1883 instrumented or otherwise use MPX. It does not use MPX
1884 itself inside the kernel or to protect the kernel
1885 against bad memory references.
1886
1887 Enabling this option will make the kernel larger:
1888 ~8k of kernel text and 36 bytes of data on a 64-bit
1889 defconfig. It adds a long to the 'mm_struct' which
1890 will increase the kernel memory overhead of each
1891 process and adds some branches to paths used during
1892 exec() and munmap().
1893
1894 For details, see Documentation/x86/intel_mpx.txt
1895
1896 If unsure, say N.
1897
35e97790 1898config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1899 prompt "Intel Memory Protection Keys"
35e97790 1900 def_bool y
284244a9 1901 # Note: only available in 64-bit mode
35e97790 1902 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1903 select ARCH_USES_HIGH_VMA_FLAGS
1904 select ARCH_HAS_PKEYS
284244a9
DH
1905 ---help---
1906 Memory Protection Keys provides a mechanism for enforcing
1907 page-based protections, but without requiring modification of the
1908 page tables when an application changes protection domains.
1909
1910 For details, see Documentation/x86/protection-keys.txt
1911
1912 If unsure, say y.
35e97790 1913
506f1d07 1914config EFI
9ba16087 1915 bool "EFI runtime service support"
5b83683f 1916 depends on ACPI
f6ce5002 1917 select UCS2_STRING
022ee6c5 1918 select EFI_RUNTIME_WRAPPERS
506f1d07 1919 ---help---
8f9ca475
IM
1920 This enables the kernel to use EFI runtime services that are
1921 available (such as the EFI variable services).
506f1d07 1922
8f9ca475
IM
1923 This option is only useful on systems that have EFI firmware.
1924 In addition, you should use the latest ELILO loader available
1925 at <http://elilo.sourceforge.net> in order to take advantage
1926 of EFI runtime services. However, even with this option, the
1927 resultant kernel should continue to boot on existing non-EFI
1928 platforms.
506f1d07 1929
291f3632
MF
1930config EFI_STUB
1931 bool "EFI stub support"
b16d8c23 1932 depends on EFI && !X86_USE_3DNOW
7b2a583a 1933 select RELOCATABLE
291f3632
MF
1934 ---help---
1935 This kernel feature allows a bzImage to be loaded directly
1936 by EFI firmware without the use of a bootloader.
1937
4172fe2f 1938 See Documentation/efi-stub.txt for more information.
0c759662 1939
7d453eee
MF
1940config EFI_MIXED
1941 bool "EFI mixed-mode support"
1942 depends on EFI_STUB && X86_64
1943 ---help---
1944 Enabling this feature allows a 64-bit kernel to be booted
1945 on a 32-bit firmware, provided that your CPU supports 64-bit
1946 mode.
1947
1948 Note that it is not possible to boot a mixed-mode enabled
1949 kernel via the EFI boot stub - a bootloader that supports
1950 the EFI handover protocol must be used.
1951
1952 If unsure, say N.
1953
506f1d07 1954config SECCOMP
3c2362e6
HH
1955 def_bool y
1956 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1957 ---help---
506f1d07
SR
1958 This kernel feature is useful for number crunching applications
1959 that may need to compute untrusted bytecode during their
1960 execution. By using pipes or other transports made available to
1961 the process as file descriptors supporting the read/write
1962 syscalls, it's possible to isolate those applications in
1963 their own address space using seccomp. Once seccomp is
9c0bbee8 1964 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1965 and the task is only allowed to execute a few safe syscalls
1966 defined by each seccomp mode.
1967
1968 If unsure, say Y. Only embedded should say N here.
1969
506f1d07
SR
1970source kernel/Kconfig.hz
1971
1972config KEXEC
1973 bool "kexec system call"
2965faa5 1974 select KEXEC_CORE
8f9ca475 1975 ---help---
506f1d07
SR
1976 kexec is a system call that implements the ability to shutdown your
1977 current kernel, and to start another kernel. It is like a reboot
1978 but it is independent of the system firmware. And like a reboot
1979 you can start any kernel with it, not just Linux.
1980
1981 The name comes from the similarity to the exec system call.
1982
1983 It is an ongoing process to be certain the hardware in a machine
1984 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1985 initially work for you. As of this writing the exact hardware
1986 interface is strongly in flux, so no good recommendation can be
1987 made.
506f1d07 1988
74ca317c
VG
1989config KEXEC_FILE
1990 bool "kexec file based system call"
2965faa5 1991 select KEXEC_CORE
74ca317c 1992 select BUILD_BIN2C
74ca317c
VG
1993 depends on X86_64
1994 depends on CRYPTO=y
1995 depends on CRYPTO_SHA256=y
1996 ---help---
1997 This is new version of kexec system call. This system call is
1998 file based and takes file descriptors as system call argument
1999 for kernel and initramfs as opposed to list of segments as
2000 accepted by previous system call.
2001
b799a09f
AT
2002config ARCH_HAS_KEXEC_PURGATORY
2003 def_bool KEXEC_FILE
2004
8e7d8381
VG
2005config KEXEC_VERIFY_SIG
2006 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2007 depends on KEXEC_FILE
8e7d8381
VG
2008 ---help---
2009 This option makes kernel signature verification mandatory for
d8eb8940
BP
2010 the kexec_file_load() syscall.
2011
2012 In addition to that option, you need to enable signature
2013 verification for the corresponding kernel image type being
2014 loaded in order for this to work.
8e7d8381
VG
2015
2016config KEXEC_BZIMAGE_VERIFY_SIG
2017 bool "Enable bzImage signature verification support"
2018 depends on KEXEC_VERIFY_SIG
2019 depends on SIGNED_PE_FILE_VERIFICATION
2020 select SYSTEM_TRUSTED_KEYRING
2021 ---help---
2022 Enable bzImage signature verification support.
2023
506f1d07 2024config CRASH_DUMP
04b69447 2025 bool "kernel crash dumps"
506f1d07 2026 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2027 ---help---
506f1d07
SR
2028 Generate crash dump after being started by kexec.
2029 This should be normally only set in special crash dump kernels
2030 which are loaded in the main kernel with kexec-tools into
2031 a specially reserved region and then later executed after
2032 a crash by kdump/kexec. The crash dump kernel must be compiled
2033 to a memory address not used by the main kernel or BIOS using
2034 PHYSICAL_START, or it must be built as a relocatable image
2035 (CONFIG_RELOCATABLE=y).
2036 For more details see Documentation/kdump/kdump.txt
2037
3ab83521 2038config KEXEC_JUMP
6ea30386 2039 bool "kexec jump"
fee7b0d8 2040 depends on KEXEC && HIBERNATION
8f9ca475 2041 ---help---
89081d17
HY
2042 Jump between original kernel and kexeced kernel and invoke
2043 code in physical address mode via KEXEC
3ab83521 2044
506f1d07 2045config PHYSICAL_START
6a108a14 2046 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2047 default "0x1000000"
8f9ca475 2048 ---help---
506f1d07
SR
2049 This gives the physical address where the kernel is loaded.
2050
2051 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2052 bzImage will decompress itself to above physical address and
2053 run from there. Otherwise, bzImage will run from the address where
2054 it has been loaded by the boot loader and will ignore above physical
2055 address.
2056
2057 In normal kdump cases one does not have to set/change this option
2058 as now bzImage can be compiled as a completely relocatable image
2059 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2060 address. This option is mainly useful for the folks who don't want
2061 to use a bzImage for capturing the crash dump and want to use a
2062 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2063 to be specifically compiled to run from a specific memory area
2064 (normally a reserved region) and this option comes handy.
2065
ceefccc9
PA
2066 So if you are using bzImage for capturing the crash dump,
2067 leave the value here unchanged to 0x1000000 and set
2068 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2069 for capturing the crash dump change this value to start of
2070 the reserved region. In other words, it can be set based on
2071 the "X" value as specified in the "crashkernel=YM@XM"
2072 command line boot parameter passed to the panic-ed
2073 kernel. Please take a look at Documentation/kdump/kdump.txt
2074 for more details about crash dumps.
506f1d07
SR
2075
2076 Usage of bzImage for capturing the crash dump is recommended as
2077 one does not have to build two kernels. Same kernel can be used
2078 as production kernel and capture kernel. Above option should have
2079 gone away after relocatable bzImage support is introduced. But it
2080 is present because there are users out there who continue to use
2081 vmlinux for dump capture. This option should go away down the
2082 line.
2083
2084 Don't change this unless you know what you are doing.
2085
2086config RELOCATABLE
26717808
PA
2087 bool "Build a relocatable kernel"
2088 default y
8f9ca475 2089 ---help---
506f1d07
SR
2090 This builds a kernel image that retains relocation information
2091 so it can be loaded someplace besides the default 1MB.
2092 The relocations tend to make the kernel binary about 10% larger,
2093 but are discarded at runtime.
2094
2095 One use is for the kexec on panic case where the recovery kernel
2096 must live at a different physical address than the primary
2097 kernel.
2098
2099 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2100 it has been loaded at and the compile time physical address
8ab3820f 2101 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2102
8ab3820f 2103config RANDOMIZE_BASE
e8581e3d 2104 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2105 depends on RELOCATABLE
6807c846 2106 default y
8ab3820f 2107 ---help---
e8581e3d
BH
2108 In support of Kernel Address Space Layout Randomization (KASLR),
2109 this randomizes the physical address at which the kernel image
2110 is decompressed and the virtual address where the kernel
2111 image is mapped, as a security feature that deters exploit
2112 attempts relying on knowledge of the location of kernel
2113 code internals.
2114
ed9f007e
KC
2115 On 64-bit, the kernel physical and virtual addresses are
2116 randomized separately. The physical address will be anywhere
2117 between 16MB and the top of physical memory (up to 64TB). The
2118 virtual address will be randomized from 16MB up to 1GB (9 bits
2119 of entropy). Note that this also reduces the memory space
2120 available to kernel modules from 1.5GB to 1GB.
2121
2122 On 32-bit, the kernel physical and virtual addresses are
2123 randomized together. They will be randomized from 16MB up to
2124 512MB (8 bits of entropy).
e8581e3d
BH
2125
2126 Entropy is generated using the RDRAND instruction if it is
2127 supported. If RDTSC is supported, its value is mixed into
2128 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2129 supported, then entropy is read from the i8254 timer. The
2130 usable entropy is limited by the kernel being built using
2131 2GB addressing, and that PHYSICAL_ALIGN must be at a
2132 minimum of 2MB. As a result, only 10 bits of entropy are
2133 theoretically possible, but the implementations are further
2134 limited due to memory layouts.
e8581e3d 2135
6807c846 2136 If unsure, say Y.
8ab3820f
KC
2137
2138# Relocation on x86 needs some additional build support
845adf72
PA
2139config X86_NEED_RELOCS
2140 def_bool y
8ab3820f 2141 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2142
506f1d07 2143config PHYSICAL_ALIGN
a0215061 2144 hex "Alignment value to which kernel should be aligned"
8ab3820f 2145 default "0x200000"
a0215061
KC
2146 range 0x2000 0x1000000 if X86_32
2147 range 0x200000 0x1000000 if X86_64
8f9ca475 2148 ---help---
506f1d07
SR
2149 This value puts the alignment restrictions on physical address
2150 where kernel is loaded and run from. Kernel is compiled for an
2151 address which meets above alignment restriction.
2152
2153 If bootloader loads the kernel at a non-aligned address and
2154 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2155 address aligned to above value and run from there.
2156
2157 If bootloader loads the kernel at a non-aligned address and
2158 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2159 load address and decompress itself to the address it has been
2160 compiled for and run from there. The address for which kernel is
2161 compiled already meets above alignment restrictions. Hence the
2162 end result is that kernel runs from a physical address meeting
2163 above alignment restrictions.
2164
a0215061
KC
2165 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2166 this value must be a multiple of 0x200000.
2167
506f1d07
SR
2168 Don't change this unless you know what you are doing.
2169
eedb92ab
KS
2170config DYNAMIC_MEMORY_LAYOUT
2171 bool
2172 ---help---
2173 This option makes base addresses of vmalloc and vmemmap as well as
2174 __PAGE_OFFSET movable during boot.
2175
0483e1fa
TG
2176config RANDOMIZE_MEMORY
2177 bool "Randomize the kernel memory sections"
2178 depends on X86_64
2179 depends on RANDOMIZE_BASE
eedb92ab 2180 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2181 default RANDOMIZE_BASE
2182 ---help---
2183 Randomizes the base virtual address of kernel memory sections
2184 (physical memory mapping, vmalloc & vmemmap). This security feature
2185 makes exploits relying on predictable memory locations less reliable.
2186
2187 The order of allocations remains unchanged. Entropy is generated in
2188 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2189 configuration have in average 30,000 different possible virtual
2190 addresses for each memory section.
2191
6807c846 2192 If unsure, say Y.
0483e1fa 2193
90397a41
TG
2194config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2195 hex "Physical memory mapping padding" if EXPERT
2196 depends on RANDOMIZE_MEMORY
2197 default "0xa" if MEMORY_HOTPLUG
2198 default "0x0"
2199 range 0x1 0x40 if MEMORY_HOTPLUG
2200 range 0x0 0x40
2201 ---help---
2202 Define the padding in terabytes added to the existing physical
2203 memory size during kernel memory randomization. It is useful
2204 for memory hotplug support but reduces the entropy available for
2205 address randomization.
2206
2207 If unsure, leave at the default value.
2208
506f1d07 2209config HOTPLUG_CPU
7c13e6a3 2210 bool "Support for hot-pluggable CPUs"
40b31360 2211 depends on SMP
506f1d07 2212 ---help---
7c13e6a3
DS
2213 Say Y here to allow turning CPUs off and on. CPUs can be
2214 controlled through /sys/devices/system/cpu.
2215 ( Note: power management support will enable this option
2216 automatically on SMP systems. )
2217 Say N if you want to disable CPU hotplug.
506f1d07 2218
80aa1dff
FY
2219config BOOTPARAM_HOTPLUG_CPU0
2220 bool "Set default setting of cpu0_hotpluggable"
2221 default n
2c922cd0 2222 depends on HOTPLUG_CPU
80aa1dff
FY
2223 ---help---
2224 Set whether default state of cpu0_hotpluggable is on or off.
2225
2226 Say Y here to enable CPU0 hotplug by default. If this switch
2227 is turned on, there is no need to give cpu0_hotplug kernel
2228 parameter and the CPU0 hotplug feature is enabled by default.
2229
2230 Please note: there are two known CPU0 dependencies if you want
2231 to enable the CPU0 hotplug feature either by this switch or by
2232 cpu0_hotplug kernel parameter.
2233
2234 First, resume from hibernate or suspend always starts from CPU0.
2235 So hibernate and suspend are prevented if CPU0 is offline.
2236
2237 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2238 offline if any interrupt can not migrate out of CPU0. There may
2239 be other CPU0 dependencies.
2240
2241 Please make sure the dependencies are under your control before
2242 you enable this feature.
2243
2244 Say N if you don't want to enable CPU0 hotplug feature by default.
2245 You still can enable the CPU0 hotplug feature at boot by kernel
2246 parameter cpu0_hotplug.
2247
a71c8bc5
FY
2248config DEBUG_HOTPLUG_CPU0
2249 def_bool n
2250 prompt "Debug CPU0 hotplug"
2c922cd0 2251 depends on HOTPLUG_CPU
a71c8bc5
FY
2252 ---help---
2253 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2254 soon as possible and boots up userspace with CPU0 offlined. User
2255 can online CPU0 back after boot time.
2256
2257 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2258 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2259 compilation or giving cpu0_hotplug kernel parameter at boot.
2260
2261 If unsure, say N.
2262
506f1d07 2263config COMPAT_VDSO
b0b49f26
AL
2264 def_bool n
2265 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2266 depends on COMPAT_32
8f9ca475 2267 ---help---
b0b49f26
AL
2268 Certain buggy versions of glibc will crash if they are
2269 presented with a 32-bit vDSO that is not mapped at the address
2270 indicated in its segment table.
e84446de 2271
b0b49f26
AL
2272 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2273 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2274 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2275 the only released version with the bug, but OpenSUSE 9
2276 contains a buggy "glibc 2.3.2".
506f1d07 2277
b0b49f26
AL
2278 The symptom of the bug is that everything crashes on startup, saying:
2279 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2280
2281 Saying Y here changes the default value of the vdso32 boot
2282 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2283 This works around the glibc bug but hurts performance.
2284
2285 If unsure, say N: if you are compiling your own kernel, you
2286 are unlikely to be using a buggy version of glibc.
506f1d07 2287
3dc33bd3
KC
2288choice
2289 prompt "vsyscall table for legacy applications"
2290 depends on X86_64
2291 default LEGACY_VSYSCALL_EMULATE
2292 help
2293 Legacy user code that does not know how to find the vDSO expects
2294 to be able to issue three syscalls by calling fixed addresses in
2295 kernel space. Since this location is not randomized with ASLR,
2296 it can be used to assist security vulnerability exploitation.
2297
2298 This setting can be changed at boot time via the kernel command
076ca272 2299 line parameter vsyscall=[emulate|none].
3dc33bd3
KC
2300
2301 On a system with recent enough glibc (2.14 or newer) and no
2302 static binaries, you can say None without a performance penalty
2303 to improve security.
2304
2305 If unsure, select "Emulate".
2306
3dc33bd3
KC
2307 config LEGACY_VSYSCALL_EMULATE
2308 bool "Emulate"
2309 help
2310 The kernel traps and emulates calls into the fixed
2311 vsyscall address mapping. This makes the mapping
2312 non-executable, but it still contains known contents,
2313 which could be used in certain rare security vulnerability
2314 exploits. This configuration is recommended when userspace
2315 still uses the vsyscall area.
2316
2317 config LEGACY_VSYSCALL_NONE
2318 bool "None"
2319 help
2320 There will be no vsyscall mapping at all. This will
2321 eliminate any risk of ASLR bypass due to the vsyscall
2322 fixed address mapping. Attempts to use the vsyscalls
2323 will be reported to dmesg, so that either old or
2324 malicious userspace programs can be identified.
2325
2326endchoice
2327
516cbf37
TB
2328config CMDLINE_BOOL
2329 bool "Built-in kernel command line"
8f9ca475 2330 ---help---
516cbf37
TB
2331 Allow for specifying boot arguments to the kernel at
2332 build time. On some systems (e.g. embedded ones), it is
2333 necessary or convenient to provide some or all of the
2334 kernel boot arguments with the kernel itself (that is,
2335 to not rely on the boot loader to provide them.)
2336
2337 To compile command line arguments into the kernel,
2338 set this option to 'Y', then fill in the
69711ca1 2339 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2340
2341 Systems with fully functional boot loaders (i.e. non-embedded)
2342 should leave this option set to 'N'.
2343
2344config CMDLINE
2345 string "Built-in kernel command string"
2346 depends on CMDLINE_BOOL
2347 default ""
8f9ca475 2348 ---help---
516cbf37
TB
2349 Enter arguments here that should be compiled into the kernel
2350 image and used at boot time. If the boot loader provides a
2351 command line at boot time, it is appended to this string to
2352 form the full kernel command line, when the system boots.
2353
2354 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2355 change this behavior.
2356
2357 In most cases, the command line (whether built-in or provided
2358 by the boot loader) should specify the device for the root
2359 file system.
2360
2361config CMDLINE_OVERRIDE
2362 bool "Built-in command line overrides boot loader arguments"
516cbf37 2363 depends on CMDLINE_BOOL
8f9ca475 2364 ---help---
516cbf37
TB
2365 Set this option to 'Y' to have the kernel ignore the boot loader
2366 command line, and use ONLY the built-in command line.
2367
2368 This is used to work around broken boot loaders. This should
2369 be set to 'N' under normal conditions.
2370
a5b9e5a2
AL
2371config MODIFY_LDT_SYSCALL
2372 bool "Enable the LDT (local descriptor table)" if EXPERT
2373 default y
2374 ---help---
2375 Linux can allow user programs to install a per-process x86
2376 Local Descriptor Table (LDT) using the modify_ldt(2) system
2377 call. This is required to run 16-bit or segmented code such as
2378 DOSEMU or some Wine programs. It is also used by some very old
2379 threading libraries.
2380
2381 Enabling this feature adds a small amount of overhead to
2382 context switches and increases the low-level kernel attack
2383 surface. Disabling it removes the modify_ldt(2) system call.
2384
2385 Saying 'N' here may make sense for embedded or server kernels.
2386
b700e7f0
SJ
2387source "kernel/livepatch/Kconfig"
2388
506f1d07
SR
2389endmenu
2390
3072e413
MH
2391config ARCH_HAS_ADD_PAGES
2392 def_bool y
2393 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2394
506f1d07
SR
2395config ARCH_ENABLE_MEMORY_HOTPLUG
2396 def_bool y
2397 depends on X86_64 || (X86_32 && HIGHMEM)
2398
35551053
GH
2399config ARCH_ENABLE_MEMORY_HOTREMOVE
2400 def_bool y
2401 depends on MEMORY_HOTPLUG
2402
e534c7c5 2403config USE_PERCPU_NUMA_NODE_ID
645a7919 2404 def_bool y
e534c7c5
LS
2405 depends on NUMA
2406
9491846f
KS
2407config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2408 def_bool y
2409 depends on X86_64 || X86_PAE
2410
c177c81e
NH
2411config ARCH_ENABLE_HUGEPAGE_MIGRATION
2412 def_bool y
2413 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2414
9c670ea3
NH
2415config ARCH_ENABLE_THP_MIGRATION
2416 def_bool y
2417 depends on X86_64 && TRANSPARENT_HUGEPAGE
2418
da85f865 2419menu "Power management and ACPI options"
e279b6c1
SR
2420
2421config ARCH_HIBERNATION_HEADER
3c2362e6 2422 def_bool y
e279b6c1 2423 depends on X86_64 && HIBERNATION
e279b6c1
SR
2424
2425source "kernel/power/Kconfig"
2426
2427source "drivers/acpi/Kconfig"
2428
efafc8b2
FT
2429source "drivers/sfi/Kconfig"
2430
a6b68076 2431config X86_APM_BOOT
6fc108a0 2432 def_bool y
282e5aab 2433 depends on APM
a6b68076 2434
e279b6c1
SR
2435menuconfig APM
2436 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2437 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2438 ---help---
2439 APM is a BIOS specification for saving power using several different
2440 techniques. This is mostly useful for battery powered laptops with
2441 APM compliant BIOSes. If you say Y here, the system time will be
2442 reset after a RESUME operation, the /proc/apm device will provide
2443 battery status information, and user-space programs will receive
2444 notification of APM "events" (e.g. battery status change).
2445
2446 If you select "Y" here, you can disable actual use of the APM
2447 BIOS by passing the "apm=off" option to the kernel at boot time.
2448
2449 Note that the APM support is almost completely disabled for
2450 machines with more than one CPU.
2451
2452 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2453 and more information, read <file:Documentation/power/apm-acpi.txt>
2454 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2455 <http://www.tldp.org/docs.html#howto>.
2456
2457 This driver does not spin down disk drives (see the hdparm(8)
2458 manpage ("man 8 hdparm") for that), and it doesn't turn off
2459 VESA-compliant "green" monitors.
2460
2461 This driver does not support the TI 4000M TravelMate and the ACER
2462 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2463 desktop machines also don't have compliant BIOSes, and this driver
2464 may cause those machines to panic during the boot phase.
2465
2466 Generally, if you don't have a battery in your machine, there isn't
2467 much point in using this driver and you should say N. If you get
2468 random kernel OOPSes or reboots that don't seem to be related to
2469 anything, try disabling/enabling this option (or disabling/enabling
2470 APM in your BIOS).
2471
2472 Some other things you should try when experiencing seemingly random,
2473 "weird" problems:
2474
2475 1) make sure that you have enough swap space and that it is
2476 enabled.
2477 2) pass the "no-hlt" option to the kernel
2478 3) switch on floating point emulation in the kernel and pass
2479 the "no387" option to the kernel
2480 4) pass the "floppy=nodma" option to the kernel
2481 5) pass the "mem=4M" option to the kernel (thereby disabling
2482 all but the first 4 MB of RAM)
2483 6) make sure that the CPU is not over clocked.
2484 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2485 8) disable the cache from your BIOS settings
2486 9) install a fan for the video card or exchange video RAM
2487 10) install a better fan for the CPU
2488 11) exchange RAM chips
2489 12) exchange the motherboard.
2490
2491 To compile this driver as a module, choose M here: the
2492 module will be called apm.
2493
2494if APM
2495
2496config APM_IGNORE_USER_SUSPEND
2497 bool "Ignore USER SUSPEND"
8f9ca475 2498 ---help---
e279b6c1
SR
2499 This option will ignore USER SUSPEND requests. On machines with a
2500 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2501 series notebooks, it is necessary to say Y because of a BIOS bug.
2502
2503config APM_DO_ENABLE
2504 bool "Enable PM at boot time"
2505 ---help---
2506 Enable APM features at boot time. From page 36 of the APM BIOS
2507 specification: "When disabled, the APM BIOS does not automatically
2508 power manage devices, enter the Standby State, enter the Suspend
2509 State, or take power saving steps in response to CPU Idle calls."
2510 This driver will make CPU Idle calls when Linux is idle (unless this
2511 feature is turned off -- see "Do CPU IDLE calls", below). This
2512 should always save battery power, but more complicated APM features
2513 will be dependent on your BIOS implementation. You may need to turn
2514 this option off if your computer hangs at boot time when using APM
2515 support, or if it beeps continuously instead of suspending. Turn
2516 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2517 T400CDT. This is off by default since most machines do fine without
2518 this feature.
2519
2520config APM_CPU_IDLE
dd8af076 2521 depends on CPU_IDLE
e279b6c1 2522 bool "Make CPU Idle calls when idle"
8f9ca475 2523 ---help---
e279b6c1
SR
2524 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2525 On some machines, this can activate improved power savings, such as
2526 a slowed CPU clock rate, when the machine is idle. These idle calls
2527 are made after the idle loop has run for some length of time (e.g.,
2528 333 mS). On some machines, this will cause a hang at boot time or
2529 whenever the CPU becomes idle. (On machines with more than one CPU,
2530 this option does nothing.)
2531
2532config APM_DISPLAY_BLANK
2533 bool "Enable console blanking using APM"
8f9ca475 2534 ---help---
e279b6c1
SR
2535 Enable console blanking using the APM. Some laptops can use this to
2536 turn off the LCD backlight when the screen blanker of the Linux
2537 virtual console blanks the screen. Note that this is only used by
2538 the virtual console screen blanker, and won't turn off the backlight
2539 when using the X Window system. This also doesn't have anything to
2540 do with your VESA-compliant power-saving monitor. Further, this
2541 option doesn't work for all laptops -- it might not turn off your
2542 backlight at all, or it might print a lot of errors to the console,
2543 especially if you are using gpm.
2544
2545config APM_ALLOW_INTS
2546 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2547 ---help---
e279b6c1
SR
2548 Normally we disable external interrupts while we are making calls to
2549 the APM BIOS as a measure to lessen the effects of a badly behaving
2550 BIOS implementation. The BIOS should reenable interrupts if it
2551 needs to. Unfortunately, some BIOSes do not -- especially those in
2552 many of the newer IBM Thinkpads. If you experience hangs when you
2553 suspend, try setting this to Y. Otherwise, say N.
2554
e279b6c1
SR
2555endif # APM
2556
bb0a56ec 2557source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2558
2559source "drivers/cpuidle/Kconfig"
2560
27471fdb
AH
2561source "drivers/idle/Kconfig"
2562
e279b6c1
SR
2563endmenu
2564
2565
2566menu "Bus options (PCI etc.)"
2567
2568config PCI
1ac97018 2569 bool "PCI support"
1c858087 2570 default y
8f9ca475 2571 ---help---
e279b6c1
SR
2572 Find out whether you have a PCI motherboard. PCI is the name of a
2573 bus system, i.e. the way the CPU talks to the other stuff inside
2574 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2575 VESA. If you have PCI, say Y, otherwise N.
2576
e279b6c1
SR
2577choice
2578 prompt "PCI access mode"
efefa6f6 2579 depends on X86_32 && PCI
e279b6c1
SR
2580 default PCI_GOANY
2581 ---help---
2582 On PCI systems, the BIOS can be used to detect the PCI devices and
2583 determine their configuration. However, some old PCI motherboards
2584 have BIOS bugs and may crash if this is done. Also, some embedded
2585 PCI-based systems don't have any BIOS at all. Linux can also try to
2586 detect the PCI hardware directly without using the BIOS.
2587
2588 With this option, you can specify how Linux should detect the
2589 PCI devices. If you choose "BIOS", the BIOS will be used,
2590 if you choose "Direct", the BIOS won't be used, and if you
2591 choose "MMConfig", then PCI Express MMCONFIG will be used.
2592 If you choose "Any", the kernel will try MMCONFIG, then the
2593 direct access method and falls back to the BIOS if that doesn't
2594 work. If unsure, go with the default, which is "Any".
2595
2596config PCI_GOBIOS
2597 bool "BIOS"
2598
2599config PCI_GOMMCONFIG
2600 bool "MMConfig"
2601
2602config PCI_GODIRECT
2603 bool "Direct"
2604
3ef0e1f8 2605config PCI_GOOLPC
76fb6570 2606 bool "OLPC XO-1"
3ef0e1f8
AS
2607 depends on OLPC
2608
2bdd1b03
AS
2609config PCI_GOANY
2610 bool "Any"
2611
e279b6c1
SR
2612endchoice
2613
2614config PCI_BIOS
3c2362e6 2615 def_bool y
efefa6f6 2616 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2617
2618# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2619config PCI_DIRECT
3c2362e6 2620 def_bool y
0aba496f 2621 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2622
2623config PCI_MMCONFIG
b45c9f36
JK
2624 bool "Support mmconfig PCI config space access" if X86_64
2625 default y
8364e1f8 2626 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2627 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2628
3ef0e1f8 2629config PCI_OLPC
2bdd1b03
AS
2630 def_bool y
2631 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2632
b5401a96
AN
2633config PCI_XEN
2634 def_bool y
2635 depends on PCI && XEN
2636 select SWIOTLB_XEN
2637
e279b6c1 2638config PCI_DOMAINS
3c2362e6 2639 def_bool y
e279b6c1 2640 depends on PCI
e279b6c1 2641
8364e1f8
JK
2642config MMCONF_FAM10H
2643 def_bool y
2644 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2645
3f6ea84a 2646config PCI_CNB20LE_QUIRK
6a108a14 2647 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2648 depends on PCI
3f6ea84a
IS
2649 help
2650 Read the PCI windows out of the CNB20LE host bridge. This allows
2651 PCI hotplug to work on systems with the CNB20LE chipset which do
2652 not have ACPI.
2653
64a5fed6
BH
2654 There's no public spec for this chipset, and this functionality
2655 is known to be incomplete.
2656
2657 You should say N unless you know you need this.
2658
e279b6c1
SR
2659source "drivers/pci/Kconfig"
2660
3a495511 2661config ISA_BUS
17a2a129 2662 bool "ISA bus support on modern systems" if EXPERT
3a495511 2663 help
17a2a129
WBG
2664 Expose ISA bus device drivers and options available for selection and
2665 configuration. Enable this option if your target machine has an ISA
2666 bus. ISA is an older system, displaced by PCI and newer bus
2667 architectures -- if your target machine is modern, it probably does
2668 not have an ISA bus.
3a495511
WBG
2669
2670 If unsure, say N.
2671
1c00f016 2672# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2673config ISA_DMA_API
1c00f016
DR
2674 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2675 default y
2676 help
2677 Enables ISA-style DMA support for devices requiring such controllers.
2678 If unsure, say Y.
e279b6c1 2679
51e68d05
LT
2680if X86_32
2681
e279b6c1
SR
2682config ISA
2683 bool "ISA support"
8f9ca475 2684 ---help---
e279b6c1
SR
2685 Find out whether you have ISA slots on your motherboard. ISA is the
2686 name of a bus system, i.e. the way the CPU talks to the other stuff
2687 inside your box. Other bus systems are PCI, EISA, MicroChannel
2688 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2689 newer boards don't support it. If you have ISA, say Y, otherwise N.
2690
2691config EISA
2692 bool "EISA support"
2693 depends on ISA
2694 ---help---
2695 The Extended Industry Standard Architecture (EISA) bus was
2696 developed as an open alternative to the IBM MicroChannel bus.
2697
2698 The EISA bus provided some of the features of the IBM MicroChannel
2699 bus while maintaining backward compatibility with cards made for
2700 the older ISA bus. The EISA bus saw limited use between 1988 and
2701 1995 when it was made obsolete by the PCI bus.
2702
2703 Say Y here if you are building a kernel for an EISA-based machine.
2704
2705 Otherwise, say N.
2706
2707source "drivers/eisa/Kconfig"
2708
e279b6c1
SR
2709config SCx200
2710 tristate "NatSemi SCx200 support"
8f9ca475 2711 ---help---
e279b6c1
SR
2712 This provides basic support for National Semiconductor's
2713 (now AMD's) Geode processors. The driver probes for the
2714 PCI-IDs of several on-chip devices, so its a good dependency
2715 for other scx200_* drivers.
2716
2717 If compiled as a module, the driver is named scx200.
2718
2719config SCx200HR_TIMER
2720 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2721 depends on SCx200
e279b6c1 2722 default y
8f9ca475 2723 ---help---
e279b6c1
SR
2724 This driver provides a clocksource built upon the on-chip
2725 27MHz high-resolution timer. Its also a workaround for
2726 NSC Geode SC-1100's buggy TSC, which loses time when the
2727 processor goes idle (as is done by the scheduler). The
2728 other workaround is idle=poll boot option.
2729
3ef0e1f8
AS
2730config OLPC
2731 bool "One Laptop Per Child support"
54008979 2732 depends on !X86_PAE
3c554946 2733 select GPIOLIB
dc3119e7 2734 select OF
45bb1674 2735 select OF_PROMTREE
b4e51854 2736 select IRQ_DOMAIN
8f9ca475 2737 ---help---
3ef0e1f8
AS
2738 Add support for detecting the unique features of the OLPC
2739 XO hardware.
2740
a3128588
DD
2741config OLPC_XO1_PM
2742 bool "OLPC XO-1 Power Management"
97c4cb71 2743 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2744 select MFD_CORE
bf1ebf00 2745 ---help---
97c4cb71 2746 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2747
cfee9597
DD
2748config OLPC_XO1_RTC
2749 bool "OLPC XO-1 Real Time Clock"
2750 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2751 ---help---
2752 Add support for the XO-1 real time clock, which can be used as a
2753 programmable wakeup source.
2754
7feda8e9
DD
2755config OLPC_XO1_SCI
2756 bool "OLPC XO-1 SCI extras"
92e830f2 2757 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2758 depends on INPUT=y
d8d01a63 2759 select POWER_SUPPLY
7feda8e9
DD
2760 ---help---
2761 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2762 - EC-driven system wakeups
7feda8e9 2763 - Power button
7bc74b3d 2764 - Ebook switch
2cf2baea 2765 - Lid switch
e1040ac6
DD
2766 - AC adapter status updates
2767 - Battery status updates
7feda8e9 2768
a0f30f59
DD
2769config OLPC_XO15_SCI
2770 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2771 depends on OLPC && ACPI
2772 select POWER_SUPPLY
a0f30f59
DD
2773 ---help---
2774 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2775 - EC-driven system wakeups
2776 - AC adapter status updates
2777 - Battery status updates
bf1ebf00 2778
d4f3e350
EW
2779config ALIX
2780 bool "PCEngines ALIX System Support (LED setup)"
2781 select GPIOLIB
2782 ---help---
2783 This option enables system support for the PCEngines ALIX.
2784 At present this just sets up LEDs for GPIO control on
2785 ALIX2/3/6 boards. However, other system specific setup should
2786 get added here.
2787
2788 Note: You must still enable the drivers for GPIO and LED support
2789 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2790
2791 Note: You have to set alix.force=1 for boards with Award BIOS.
2792
da4e3302
PP
2793config NET5501
2794 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2795 select GPIOLIB
2796 ---help---
2797 This option enables system support for the Soekris Engineering net5501.
2798
3197059a
PP
2799config GEOS
2800 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2801 select GPIOLIB
2802 depends on DMI
2803 ---help---
2804 This option enables system support for the Traverse Technologies GEOS.
2805
7d029125
VD
2806config TS5500
2807 bool "Technologic Systems TS-5500 platform support"
2808 depends on MELAN
2809 select CHECK_SIGNATURE
2810 select NEW_LEDS
2811 select LEDS_CLASS
2812 ---help---
2813 This option enables system support for the Technologic Systems TS-5500.
2814
bc0120fd
SR
2815endif # X86_32
2816
23ac4ae8 2817config AMD_NB
e279b6c1 2818 def_bool y
0e152cd7 2819 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2820
2821source "drivers/pcmcia/Kconfig"
2822
388b78ad 2823config RAPIDIO
fdf90abc 2824 tristate "RapidIO support"
388b78ad
AB
2825 depends on PCI
2826 default n
2827 help
fdf90abc 2828 If enabled this option will include drivers and the core
388b78ad
AB
2829 infrastructure code to support RapidIO interconnect devices.
2830
2831source "drivers/rapidio/Kconfig"
2832
e3263ab3
DH
2833config X86_SYSFB
2834 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2835 help
2836 Firmwares often provide initial graphics framebuffers so the BIOS,
2837 bootloader or kernel can show basic video-output during boot for
2838 user-guidance and debugging. Historically, x86 used the VESA BIOS
2839 Extensions and EFI-framebuffers for this, which are mostly limited
2840 to x86.
2841 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2842 framebuffers so the new generic system-framebuffer drivers can be
2843 used on x86. If the framebuffer is not compatible with the generic
2844 modes, it is adverticed as fallback platform framebuffer so legacy
2845 drivers like efifb, vesafb and uvesafb can pick it up.
2846 If this option is not selected, all system framebuffers are always
2847 marked as fallback platform framebuffers as usual.
2848
2849 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2850 not be able to pick up generic system framebuffers if this option
2851 is selected. You are highly encouraged to enable simplefb as
2852 replacement if you select this option. simplefb can correctly deal
2853 with generic system framebuffers. But you should still keep vesafb
2854 and others enabled as fallback if a system framebuffer is
2855 incompatible with simplefb.
2856
2857 If unsure, say Y.
2858
e279b6c1
SR
2859endmenu
2860
2861
2862menu "Executable file formats / Emulations"
2863
2864source "fs/Kconfig.binfmt"
2865
2866config IA32_EMULATION
2867 bool "IA32 Emulation"
2868 depends on X86_64
39f88911 2869 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2870 select BINFMT_ELF
a97f52e6 2871 select COMPAT_BINFMT_ELF
39f88911 2872 select COMPAT_OLD_SIGACTION
8f9ca475 2873 ---help---
5fd92e65
L
2874 Include code to run legacy 32-bit programs under a
2875 64-bit kernel. You should likely turn this on, unless you're
2876 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2877
2878config IA32_AOUT
8f9ca475
IM
2879 tristate "IA32 a.out support"
2880 depends on IA32_EMULATION
2881 ---help---
2882 Support old a.out binaries in the 32bit emulation.
e279b6c1 2883
0bf62763 2884config X86_X32
6ea30386 2885 bool "x32 ABI for 64-bit mode"
9b54050b 2886 depends on X86_64
5fd92e65
L
2887 ---help---
2888 Include code to run binaries for the x32 native 32-bit ABI
2889 for 64-bit processors. An x32 process gets access to the
2890 full 64-bit register file and wide data path while leaving
2891 pointers at 32 bits for smaller memory footprint.
2892
2893 You will need a recent binutils (2.22 or later) with
2894 elf32_x86_64 support enabled to compile a kernel with this
2895 option set.
2896
953fee1d
IM
2897config COMPAT_32
2898 def_bool y
2899 depends on IA32_EMULATION || X86_32
2900 select HAVE_UID16
2901 select OLD_SIGSUSPEND3
2902
e279b6c1 2903config COMPAT
3c2362e6 2904 def_bool y
0bf62763 2905 depends on IA32_EMULATION || X86_X32
e279b6c1 2906
3120e25e 2907if COMPAT
e279b6c1 2908config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2909 def_bool y
e279b6c1
SR
2910
2911config SYSVIPC_COMPAT
3c2362e6 2912 def_bool y
3120e25e 2913 depends on SYSVIPC
3120e25e 2914endif
ee009e4a 2915
e279b6c1
SR
2916endmenu
2917
2918
e5beae16
KP
2919config HAVE_ATOMIC_IOMAP
2920 def_bool y
2921 depends on X86_32
2922
4692d77f
AR
2923config X86_DEV_DMA_OPS
2924 bool
83125a3a 2925 depends on X86_64 || STA2X11
4692d77f 2926
f7219a53
AR
2927config X86_DMA_REMAP
2928 bool
83125a3a 2929 depends on STA2X11
f7219a53 2930
e585513b
KS
2931config HAVE_GENERIC_GUP
2932 def_bool y
2933
e279b6c1
SR
2934source "net/Kconfig"
2935
2936source "drivers/Kconfig"
2937
2938source "drivers/firmware/Kconfig"
2939
2940source "fs/Kconfig"
2941
e279b6c1
SR
2942source "arch/x86/Kconfig.debug"
2943
2944source "security/Kconfig"
2945
2946source "crypto/Kconfig"
2947
edf88417
AK
2948source "arch/x86/kvm/Kconfig"
2949
e279b6c1 2950source "lib/Kconfig"