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b2441318 1# SPDX-License-Identifier: GPL-2.0
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SR
2# Select 32 or 64 bit
3config 64BIT
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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
117ed454 17 select HAVE_DEBUG_STACKOVERFLOW
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IM
18 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
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SR
20
21config X86_64
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JB
22 def_bool y
23 depends on 64BIT
d94e0685 24 # Options that are inherently 64-bit kernel only:
8df995f6 25 select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
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IM
26 select ARCH_SUPPORTS_INT128
27 select ARCH_USE_CMPXCHG_LOCKREF
28 select HAVE_ARCH_SOFT_DIRTY
29 select MODULES_USE_ELF_RELA
f616ab59 30 select NEED_DMA_MAP_STATE
09230cbc 31 select SWIOTLB
f8781c4a 32 select ARCH_HAS_SYSCALL_WRAPPER
1032c0ba 33
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IM
34#
35# Arch settings
36#
37# ( Note that options that are marked 'if X86_64' could in principle be
38# ported to 32-bit as well. )
39#
8d5fffb9 40config X86
3c2362e6 41 def_bool y
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IM
42 #
43 # Note: keep this list sorted alphabetically
44 #
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IM
45 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
46 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 47 select ARCH_32BIT_OFF_T if X86_32
6471b825 48 select ARCH_CLOCKSOURCE_DATA
2a21ad57 49 select ARCH_CLOCKSOURCE_INIT
6471b825 50 select ARCH_DISCARD_MEMBLOCK
c763ea26 51 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 52 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 53 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 54 select ARCH_HAS_ELF_RANDOMIZE
72d93104 55 select ARCH_HAS_FAST_MULTIPLIER
316d097c 56 select ARCH_HAS_FILTER_PGPROT
6974f0c4 57 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 58 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 59 select ARCH_HAS_KCOV if X86_64
10bcc80e 60 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 61 select ARCH_HAS_PMEM_API if X86_64
3010a5ea 62 select ARCH_HAS_PTE_SPECIAL
39208aa7 63 select ARCH_HAS_REFCOUNT
0aed55af 64 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
092b31aa 65 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
d2852a22 66 select ARCH_HAS_SET_MEMORY
d253ca0c 67 select ARCH_HAS_SET_DIRECT_MAP
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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
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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
3599fe12 77 select ARCH_STACKWALK
2c870e61 78 select ARCH_SUPPORTS_ACPI
6471b825 79 select ARCH_SUPPORTS_ATOMIC_RMW
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80 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
81 select ARCH_USE_BUILTIN_BSWAP
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82 select ARCH_USE_QUEUED_RWLOCKS
83 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 85 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
38d8b4e6 86 select ARCH_WANTS_THP_SWAP if X86_64
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87 select BUILDTIME_EXTABLE_SORT
88 select CLKEVT_I8253
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IM
89 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
90 select CLOCKSOURCE_WATCHDOG
6471b825 91 select DCACHE_WORD_ACCESS
45471cd9
LT
92 select EDAC_ATOMIC_SCRUB
93 select EDAC_SUPPORT
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IM
94 select GENERIC_CLOCKEVENTS
95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
96 select GENERIC_CLOCKEVENTS_MIN_ADJUST
97 select GENERIC_CMOS_UPDATE
98 select GENERIC_CPU_AUTOPROBE
61dc0f55 99 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 100 select GENERIC_EARLY_IOREMAP
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IM
101 select GENERIC_FIND_FIRST_BIT
102 select GENERIC_IOMAP
c7d6c9dd 103 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 104 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 105 select GENERIC_IRQ_MIGRATION if SMP
6471b825 106 select GENERIC_IRQ_PROBE
c201c917 107 select GENERIC_IRQ_RESERVATION_MODE
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IM
108 select GENERIC_IRQ_SHOW
109 select GENERIC_PENDING_IRQ if SMP
110 select GENERIC_SMP_IDLE_THREAD
111 select GENERIC_STRNCPY_FROM_USER
112 select GENERIC_STRNLEN_USER
113 select GENERIC_TIME_VSYSCALL
7edaeb68 114 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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IM
115 select HAVE_ACPI_APEI if ACPI
116 select HAVE_ACPI_APEI_NMI if ACPI
117 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
118 select HAVE_ARCH_AUDITSYSCALL
119 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
120 select HAVE_ARCH_JUMP_LABEL
b34006c4 121 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 122 select HAVE_ARCH_KASAN if X86_64
6471b825 123 select HAVE_ARCH_KGDB
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DC
124 select HAVE_ARCH_MMAP_RND_BITS if MMU
125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 126 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 127 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 128 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 130 select HAVE_ARCH_STACKLEAK
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IM
131 select HAVE_ARCH_TRACEHOOK
132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 133 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 134 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 135 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
136 select HAVE_CMPXCHG_DOUBLE
137 select HAVE_CMPXCHG_LOCAL
138 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 139 select HAVE_COPY_THREAD_TLS
cf4db259 140 select HAVE_C_RECORDMCOUNT
6471b825 141 select HAVE_DEBUG_KMEMLEAK
6471b825 142 select HAVE_DMA_CONTIGUOUS
677aa9f7 143 select HAVE_DYNAMIC_FTRACE
06aeaaea 144 select HAVE_DYNAMIC_FTRACE_WITH_REGS
03f5781b 145 select HAVE_EBPF_JIT
58340a07 146 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 147 select HAVE_EISA
5f56a5df 148 select HAVE_EXIT_THREAD
644e0e8d 149 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 150 select HAVE_FTRACE_MCOUNT_RECORD
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151 select HAVE_FUNCTION_GRAPH_TRACER
152 select HAVE_FUNCTION_TRACER
6b90bd4b 153 select HAVE_GCC_PLUGINS
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154 select HAVE_HW_BREAKPOINT
155 select HAVE_IDE
156 select HAVE_IOREMAP_PROT
157 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
158 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 159 select HAVE_KERNEL_BZIP2
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160 select HAVE_KERNEL_GZIP
161 select HAVE_KERNEL_LZ4
2e9f3bdd 162 select HAVE_KERNEL_LZMA
13510997 163 select HAVE_KERNEL_LZO
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164 select HAVE_KERNEL_XZ
165 select HAVE_KPROBES
166 select HAVE_KPROBES_ON_FTRACE
540adea3 167 select HAVE_FUNCTION_ERROR_INJECTION
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168 select HAVE_KRETPROBES
169 select HAVE_KVM
170 select HAVE_LIVEPATCH if X86_64
6471b825 171 select HAVE_MEMBLOCK_NODE_MAP
0102752e 172 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 173 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 174 select HAVE_MOVE_PMD
42a0bb3f 175 select HAVE_NMI
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IM
176 select HAVE_OPROFILE
177 select HAVE_OPTPROBES
178 select HAVE_PCSPKR_PLATFORM
179 select HAVE_PERF_EVENTS
c01d4323 180 select HAVE_PERF_EVENTS_NMI
92e5aae4 181 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 182 select HAVE_PCI
c5e63197 183 select HAVE_PERF_REGS
c5ebcedb 184 select HAVE_PERF_USER_STACK_DUMP
48a8b97c 185 select HAVE_RCU_TABLE_FREE if PARAVIRT
6471b825 186 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 187 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 188 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 189 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 190 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 191 select HAVE_RSEQ
6471b825 192 select HAVE_SYSCALL_TRACEPOINTS
6471b825 193 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 194 select HAVE_USER_RETURN_NOTIFIER
05736e4a 195 select HOTPLUG_SMT if SMP
c0185808 196 select IRQ_FORCED_THREADING
86596f0a 197 select NEED_SG_DMA_LENGTH
2eac9c2d 198 select PCI_DOMAINS if PCI
625210cf 199 select PCI_LOCKLESS_CONFIG if PCI
6471b825 200 select PERF_EVENTS
3195ef59 201 select RTC_LIB
d6faca40 202 select RTC_MC146818_LIB
6471b825 203 select SPARSE_IRQ
83fe27ea 204 select SRCU
6471b825 205 select SYSCTL_EXCEPTION_TRACE
15f4eae7 206 select THREAD_INFO_IN_TASK
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IM
207 select USER_STACKTRACE_SUPPORT
208 select VIRT_TO_BUS
6471b825 209 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 210
ba7e4d13 211config INSTRUCTION_DECODER
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212 def_bool y
213 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 214
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LT
215config OUTPUT_FORMAT
216 string
217 default "elf32-i386" if X86_32
218 default "elf64-x86-64" if X86_64
219
73531905 220config ARCH_DEFCONFIG
b9b39bfb 221 string
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SR
222 default "arch/x86/configs/i386_defconfig" if X86_32
223 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 224
8d5fffb9 225config LOCKDEP_SUPPORT
3c2362e6 226 def_bool y
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SR
227
228config STACKTRACE_SUPPORT
3c2362e6 229 def_bool y
8d5fffb9 230
8d5fffb9 231config MMU
3c2362e6 232 def_bool y
8d5fffb9 233
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DC
234config ARCH_MMAP_RND_BITS_MIN
235 default 28 if 64BIT
236 default 8
237
238config ARCH_MMAP_RND_BITS_MAX
239 default 32 if 64BIT
240 default 16
241
242config ARCH_MMAP_RND_COMPAT_BITS_MIN
243 default 8
244
245config ARCH_MMAP_RND_COMPAT_BITS_MAX
246 default 16
247
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SR
248config SBUS
249 bool
250
251config GENERIC_ISA_DMA
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JB
252 def_bool y
253 depends on ISA_DMA_API
8d5fffb9 254
8d5fffb9 255config GENERIC_BUG
3c2362e6 256 def_bool y
8d5fffb9 257 depends on BUG
b93a531e
JB
258 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
259
260config GENERIC_BUG_RELATIVE_POINTERS
261 bool
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SR
262
263config GENERIC_HWEIGHT
3c2362e6 264 def_bool y
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SR
265
266config ARCH_MAY_HAVE_PC_FDC
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267 def_bool y
268 depends on ISA_DMA_API
8d5fffb9 269
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SR
270config GENERIC_CALIBRATE_DELAY
271 def_bool y
272
9a0b8415 273config ARCH_HAS_CPU_RELAX
274 def_bool y
275
1b27d05b
PE
276config ARCH_HAS_CACHE_LINE_SIZE
277 def_bool y
278
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DH
279config ARCH_HAS_FILTER_PGPROT
280 def_bool y
281
dd5af90a 282config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 283 def_bool y
b32ef636 284
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TH
285config NEED_PER_CPU_EMBED_FIRST_CHUNK
286 def_bool y
287
288config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
289 def_bool y
290
801e4062
JB
291config ARCH_HIBERNATION_POSSIBLE
292 def_bool y
801e4062 293
f4cb5700
JB
294config ARCH_SUSPEND_POSSIBLE
295 def_bool y
f4cb5700 296
cfe28c5d
SC
297config ARCH_WANT_HUGE_PMD_SHARE
298 def_bool y
299
53313b2c
SC
300config ARCH_WANT_GENERAL_HUGETLB
301 def_bool y
302
8d5fffb9 303config ZONE_DMA32
e0fd24a3 304 def_bool y if X86_64
8d5fffb9 305
8d5fffb9 306config AUDIT_ARCH
e0fd24a3 307 def_bool y if X86_64
8d5fffb9 308
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IM
309config ARCH_SUPPORTS_OPTIMIZED_INLINING
310 def_bool y
311
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AM
312config ARCH_SUPPORTS_DEBUG_PAGEALLOC
313 def_bool y
314
d6f2d75a
AR
315config KASAN_SHADOW_OFFSET
316 hex
317 depends on KASAN
318 default 0xdffffc0000000000
319
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320config HAVE_INTEL_TXT
321 def_bool y
6ea30386 322 depends on INTEL_IOMMU && ACPI
69575d38 323
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SR
324config X86_32_SMP
325 def_bool y
326 depends on X86_32 && SMP
327
328config X86_64_SMP
329 def_bool y
330 depends on X86_64 && SMP
331
ccbeed3a
TH
332config X86_32_LAZY_GS
333 def_bool y
8458f8c2 334 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 335
2b144498
SD
336config ARCH_SUPPORTS_UPROBES
337 def_bool y
338
d20642f0
RH
339config FIX_EARLYCON_MEM
340 def_bool y
341
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KS
342config DYNAMIC_PHYSICAL_MASK
343 bool
344
98233368
KS
345config PGTABLE_LEVELS
346 int
77ef56e4 347 default 5 if X86_5LEVEL
98233368
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348 default 4 if X86_64
349 default 3 if X86_PAE
350 default 2
351
2a61f474
MY
352config CC_HAS_SANE_STACKPROTECTOR
353 bool
354 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
355 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
356 help
357 We have to make sure stack protector is unconditionally disabled if
358 the compiler produces broken code.
359
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SR
360menu "Processor type and features"
361
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RD
362config ZONE_DMA
363 bool "DMA memory allocation support" if EXPERT
364 default y
365 help
366 DMA memory allocation support allows devices with less than 32-bit
367 addressing to allocate within the first 16MB of address space.
368 Disable if no such devices will be used.
369
370 If unsure, say Y.
371
506f1d07
SR
372config SMP
373 bool "Symmetric multi-processing support"
374 ---help---
375 This enables support for systems with more than one CPU. If you have
4a474157
RG
376 a system with only one CPU, say N. If you have a system with more
377 than one CPU, say Y.
506f1d07 378
4a474157 379 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
380 machines, but will use only one CPU of a multiprocessor machine. If
381 you say Y here, the kernel will run on many, but not all,
4a474157 382 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
383 will run faster if you say N here.
384
385 Note that if you say Y here and choose architecture "586" or
386 "Pentium" under "Processor family", the kernel will not work on 486
387 architectures. Similarly, multiprocessor kernels for the "PPro"
388 architecture may not work on all Pentium based boards.
389
390 People using multiprocessor machines who say Y here should also say
391 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
392 Management" code will be disabled if you say Y here.
393
395cf969 394 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 395 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
506f1d07
SR
396 <http://www.tldp.org/docs.html#howto>.
397
398 If you don't know what to do here, say N.
399
9def39be
JT
400config X86_FEATURE_NAMES
401 bool "Processor feature human-readable names" if EMBEDDED
402 default y
403 ---help---
404 This option compiles in a table of x86 feature bits and corresponding
405 names. This is required to support /proc/cpuinfo and a few kernel
406 messages. You can disable this to save space, at the expense of
407 making those few kernel messages show numeric feature bits instead.
408
409 If in doubt, say Y.
410
06cd9a7d
YL
411config X86_X2APIC
412 bool "Support x2apic"
19e3d60d 413 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
414 ---help---
415 This enables x2apic support on CPUs that have this feature.
416
417 This allows 32-bit apic IDs (so it can support very large systems),
418 and accesses the local apic via MSRs not via mmio.
419
06cd9a7d
YL
420 If you don't know what to do here, say N.
421
6695c85b 422config X86_MPPARSE
6e87f9b7 423 bool "Enable MPS table" if ACPI || SFI
7a527688 424 default y
5ab74722 425 depends on X86_LOCAL_APIC
8f9ca475 426 ---help---
6695c85b
YL
427 For old smp systems that do not have proper acpi support. Newer systems
428 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 429
ddd70cf9
JN
430config GOLDFISH
431 def_bool y
432 depends on X86_GOLDFISH
433
76b04384
DW
434config RETPOLINE
435 bool "Avoid speculative indirect branches in kernel"
436 default y
d5028ba8 437 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
438 help
439 Compile kernel with the retpoline compiler options to guard against
440 kernel-to-user data leaks by avoiding speculative indirect
441 branches. Requires a compiler with -mindirect-branch=thunk-extern
442 support for full protection. The kernel may run slower.
443
e6d42931
JW
444config X86_CPU_RESCTRL
445 bool "x86 CPU resource control support"
6fe07ce3 446 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 447 select KERNFS
78e99b4a 448 help
e6d42931 449 Enable x86 CPU resource control support.
6fe07ce3
BM
450
451 Provide support for the allocation and monitoring of system resources
452 usage by the CPU.
453
454 Intel calls this Intel Resource Director Technology
455 (Intel(R) RDT). More information about RDT can be found in the
456 Intel x86 Architecture Software Developer Manual.
457
458 AMD calls this AMD Platform Quality of Service (AMD QoS).
459 More information about AMD QoS can be found in the AMD64 Technology
460 Platform Quality of Service Extensions manual.
78e99b4a
FY
461
462 Say N if unsure.
463
8425091f 464if X86_32
a0d0bb4d
RD
465config X86_BIGSMP
466 bool "Support for big SMP systems with more than 8 CPUs"
467 depends on SMP
468 ---help---
469 This option is needed for the systems that have more than 8 CPUs
470
c5c606d9
RT
471config X86_EXTENDED_PLATFORM
472 bool "Support for extended (non-PC) x86 platforms"
473 default y
8f9ca475 474 ---help---
06ac8346
IM
475 If you disable this option then the kernel will only support
476 standard PC platforms. (which covers the vast majority of
477 systems out there.)
478
8425091f
RT
479 If you enable this option then you'll be able to select support
480 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 481 Goldfish (Android emulator)
8425091f 482 AMD Elan
8425091f
RT
483 RDC R-321x SoC
484 SGI 320/540 (Visual Workstation)
83125a3a 485 STA2X11-based (e.g. Northville)
3f4110a4 486 Moorestown MID devices
06ac8346
IM
487
488 If you have one of these systems, or if you want to build a
489 generic distribution kernel, say Y here - otherwise say N.
8425091f 490endif
06ac8346 491
8425091f
RT
492if X86_64
493config X86_EXTENDED_PLATFORM
494 bool "Support for extended (non-PC) x86 platforms"
495 default y
496 ---help---
497 If you disable this option then the kernel will only support
498 standard PC platforms. (which covers the vast majority of
499 systems out there.)
500
501 If you enable this option then you'll be able to select support
502 for the following (non-PC) 64 bit x86 platforms:
44b111b5 503 Numascale NumaChip
8425091f
RT
504 ScaleMP vSMP
505 SGI Ultraviolet
506
507 If you have one of these systems, or if you want to build a
508 generic distribution kernel, say Y here - otherwise say N.
509endif
c5c606d9
RT
510# This is an alphabetically sorted list of 64 bit extended platforms
511# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
512config X86_NUMACHIP
513 bool "Numascale NumaChip"
514 depends on X86_64
515 depends on X86_EXTENDED_PLATFORM
516 depends on NUMA
517 depends on SMP
518 depends on X86_X2APIC
f9726bfd 519 depends on PCI_MMCONFIG
44b111b5
SP
520 ---help---
521 Adds support for Numascale NumaChip large-SMP systems. Needed to
522 enable more than ~168 cores.
523 If you don't have one of these, you should say N here.
506f1d07 524
c5c606d9
RT
525config X86_VSMP
526 bool "ScaleMP vSMP"
6276a074 527 select HYPERVISOR_GUEST
c5c606d9
RT
528 select PARAVIRT
529 depends on X86_64 && PCI
530 depends on X86_EXTENDED_PLATFORM
ead91d4b 531 depends on SMP
8f9ca475 532 ---help---
c5c606d9
RT
533 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
534 supposed to run on these EM64T-based machines. Only choose this option
535 if you have one of these machines.
5e3a77e9 536
03b48632
NP
537config X86_UV
538 bool "SGI Ultraviolet"
539 depends on X86_64
c5c606d9 540 depends on X86_EXTENDED_PLATFORM
54c28d29 541 depends on NUMA
1ecb4ae5 542 depends on EFI
9d6c26e7 543 depends on X86_X2APIC
1222e564 544 depends on PCI
8f9ca475 545 ---help---
03b48632
NP
546 This option is needed in order to support SGI Ultraviolet systems.
547 If you don't have one of these, you should say N here.
548
c5c606d9
RT
549# Following is an alphabetically sorted list of 32 bit extended platforms
550# Please maintain the alphabetic order if and when there are additions
506f1d07 551
ddd70cf9
JN
552config X86_GOLDFISH
553 bool "Goldfish (Virtual Platform)"
cb7b8023 554 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
555 ---help---
556 Enable support for the Goldfish virtual platform used primarily
557 for Android development. Unless you are building for the Android
558 Goldfish emulator say N here.
559
c751e17b
TG
560config X86_INTEL_CE
561 bool "CE4100 TV platform"
562 depends on PCI
563 depends on PCI_GODIRECT
6084a6e2 564 depends on X86_IO_APIC
c751e17b
TG
565 depends on X86_32
566 depends on X86_EXTENDED_PLATFORM
37bc9f50 567 select X86_REBOOTFIXUPS
da6b737b
SAS
568 select OF
569 select OF_EARLY_FLATTREE
c751e17b
TG
570 ---help---
571 Select for the Intel CE media processor (CE4100) SOC.
572 This option compiles in support for the CE4100 SOC for settop
573 boxes and media devices.
574
4cb9b00f 575config X86_INTEL_MID
43605ef1 576 bool "Intel MID platform support"
43605ef1 577 depends on X86_EXTENDED_PLATFORM
edc6bc78 578 depends on X86_PLATFORM_DEVICES
1ea7c673 579 depends on PCI
3fda5bb4 580 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 581 depends on X86_IO_APIC
7c9c3a1e 582 select SFI
4cb9b00f 583 select I2C
7c9c3a1e 584 select DW_APB_TIMER
1ea7c673 585 select APB_TIMER
1ea7c673 586 select INTEL_SCU_IPC
15a713df 587 select MFD_INTEL_MSIC
1ea7c673 588 ---help---
4cb9b00f
DC
589 Select to build a kernel capable of supporting Intel MID (Mobile
590 Internet Device) platform systems which do not have the PCI legacy
591 interfaces. If you are building for a PC class system say N here.
1ea7c673 592
4cb9b00f
DC
593 Intel MID platforms are based on an Intel processor and chipset which
594 consume less power than most of the x86 derivatives.
43605ef1 595
8bbc2a13
BD
596config X86_INTEL_QUARK
597 bool "Intel Quark platform support"
598 depends on X86_32
599 depends on X86_EXTENDED_PLATFORM
600 depends on X86_PLATFORM_DEVICES
601 depends on X86_TSC
602 depends on PCI
603 depends on PCI_GOANY
604 depends on X86_IO_APIC
605 select IOSF_MBI
606 select INTEL_IMR
9ab6eb51 607 select COMMON_CLK
8bbc2a13
BD
608 ---help---
609 Select to include support for Quark X1000 SoC.
610 Say Y here if you have a Quark based system such as the Arduino
611 compatible Intel Galileo.
612
3d48aab1
MW
613config X86_INTEL_LPSS
614 bool "Intel Low Power Subsystem Support"
5962dd22 615 depends on X86 && ACPI && PCI
3d48aab1 616 select COMMON_CLK
0f531431 617 select PINCTRL
eebb3e8d 618 select IOSF_MBI
3d48aab1
MW
619 ---help---
620 Select to build support for Intel Low Power Subsystem such as
621 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
622 things like clock tree (common clock framework) and pincontrol
623 which are needed by the LPSS peripheral drivers.
3d48aab1 624
92082a88
KX
625config X86_AMD_PLATFORM_DEVICE
626 bool "AMD ACPI2Platform devices support"
627 depends on ACPI
628 select COMMON_CLK
629 select PINCTRL
630 ---help---
631 Select to interpret AMD specific ACPI device to platform device
632 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
633 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
634 implemented under PINCTRL subsystem.
635
ced3ce76
DB
636config IOSF_MBI
637 tristate "Intel SoC IOSF Sideband support for SoC platforms"
638 depends on PCI
639 ---help---
640 This option enables sideband register access support for Intel SoC
641 platforms. On these platforms the IOSF sideband is used in lieu of
642 MSR's for some register accesses, mostly but not limited to thermal
643 and power. Drivers may query the availability of this device to
644 determine if they need the sideband in order to work on these
645 platforms. The sideband is available on the following SoC products.
646 This list is not meant to be exclusive.
647 - BayTrail
648 - Braswell
649 - Quark
650
651 You should say Y if you are running a kernel on one of these SoC's.
652
ed2226bd
DB
653config IOSF_MBI_DEBUG
654 bool "Enable IOSF sideband access through debugfs"
655 depends on IOSF_MBI && DEBUG_FS
656 ---help---
657 Select this option to expose the IOSF sideband access registers (MCR,
658 MDR, MCRX) through debugfs to write and read register information from
659 different units on the SoC. This is most useful for obtaining device
660 state information for debug and analysis. As this is a general access
661 mechanism, users of this option would have specific knowledge of the
662 device they want to access.
663
664 If you don't require the option or are in doubt, say N.
665
c5c606d9
RT
666config X86_RDC321X
667 bool "RDC R-321x SoC"
506f1d07 668 depends on X86_32
c5c606d9
RT
669 depends on X86_EXTENDED_PLATFORM
670 select M486
671 select X86_REBOOTFIXUPS
672 ---help---
673 This option is needed for RDC R-321x system-on-chip, also known
674 as R-8610-(G).
675 If you don't have one of these chips, you should say N here.
676
e0c7ae37 677config X86_32_NON_STANDARD
9c398017
IM
678 bool "Support non-standard 32-bit SMP architectures"
679 depends on X86_32 && SMP
c5c606d9 680 depends on X86_EXTENDED_PLATFORM
8f9ca475 681 ---help---
b5660ba7
PA
682 This option compiles in the bigsmp and STA2X11 default
683 subarchitectures. It is intended for a generic binary
684 kernel. If you select them all, kernel will probe it one by
685 one and will fallback to default.
d49c4288 686
c5c606d9 687# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 688
d949f36f 689config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 690 def_bool y
d949f36f
LT
691 # MCE code calls memory_failure():
692 depends on X86_MCE
693 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
694 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
695 depends on X86_64 || !SPARSEMEM
696 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 697
83125a3a
AR
698config STA2X11
699 bool "STA2X11 Companion Chip Support"
700 depends on X86_32_NON_STANDARD && PCI
b6e05477 701 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
702 select SWIOTLB
703 select MFD_STA2X11
0145071b 704 select GPIOLIB
83125a3a
AR
705 ---help---
706 This adds support for boards based on the STA2X11 IO-Hub,
707 a.k.a. "ConneXt". The chip is used in place of the standard
708 PC chipset, so all "standard" peripherals are missing. If this
709 option is selected the kernel will still be able to boot on
710 standard PC machines.
711
82148d1d
S
712config X86_32_IRIS
713 tristate "Eurobraille/Iris poweroff module"
714 depends on X86_32
715 ---help---
716 The Iris machines from EuroBraille do not have APM or ACPI support
717 to shut themselves down properly. A special I/O sequence is
718 needed to do so, which is what this module does at
719 kernel shutdown.
720
721 This is only for Iris machines from EuroBraille.
722
723 If unused, say N.
724
ae1e9130 725config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
726 def_bool y
727 prompt "Single-depth WCHAN output"
a87d0914 728 depends on X86
8f9ca475 729 ---help---
506f1d07
SR
730 Calculate simpler /proc/<PID>/wchan values. If this option
731 is disabled then wchan values will recurse back to the
732 caller function. This provides more accurate wchan values,
733 at the expense of slightly more scheduling overhead.
734
735 If in doubt, say "Y".
736
6276a074
BP
737menuconfig HYPERVISOR_GUEST
738 bool "Linux guest support"
8f9ca475 739 ---help---
6276a074
BP
740 Say Y here to enable options for running Linux under various hyper-
741 visors. This option enables basic hypervisor detection and platform
742 setup.
506f1d07 743
6276a074
BP
744 If you say N, all options in this submenu will be skipped and
745 disabled, and Linux guest support won't be built in.
506f1d07 746
6276a074 747if HYPERVISOR_GUEST
506f1d07 748
e61bd94a
EPH
749config PARAVIRT
750 bool "Enable paravirtualization code"
8f9ca475 751 ---help---
e61bd94a
EPH
752 This changes the kernel so it can modify itself when it is run
753 under a hypervisor, potentially improving performance significantly
754 over full virtualization. However, when run without a hypervisor
755 the kernel is theoretically slower and slightly larger.
756
c00a280a
JG
757config PARAVIRT_XXL
758 bool
759
6276a074
BP
760config PARAVIRT_DEBUG
761 bool "paravirt-ops debugging"
762 depends on PARAVIRT && DEBUG_KERNEL
763 ---help---
764 Enable to debug paravirt_ops internals. Specifically, BUG if
765 a paravirt_op is missing when it is called.
766
b4ecc126
JF
767config PARAVIRT_SPINLOCKS
768 bool "Paravirtualization layer for spinlocks"
6ea30386 769 depends on PARAVIRT && SMP
b4ecc126
JF
770 ---help---
771 Paravirtualized spinlocks allow a pvops backend to replace the
772 spinlock implementation with something virtualization-friendly
773 (for example, block the virtual CPU rather than spinning).
774
4c4e4f61
R
775 It has a minimal impact on native kernels and gives a nice performance
776 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 777
4c4e4f61 778 If you are unsure how to answer this question, answer Y.
b4ecc126 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
7733607f
MW
794config PVH
795 bool "Support for running PVH guests"
796 ---help---
797 This option enables the PVH entry point for guest virtual machines
798 as specified in the x86/HVM direct boot ABI.
799
1e20eb85
SV
800config KVM_DEBUG_FS
801 bool "Enable debug information for KVM Guests in debugfs"
802 depends on KVM_GUEST && DEBUG_FS
1e20eb85
SV
803 ---help---
804 This option enables collection of various statistics for KVM guest.
805 Statistics are displayed in debugfs filesystem. Enabling this option
806 may incur significant overhead.
807
6276a074
BP
808config PARAVIRT_TIME_ACCOUNTING
809 bool "Paravirtual steal time accounting"
810 depends on PARAVIRT
8f9ca475 811 ---help---
6276a074
BP
812 Select this option to enable fine granularity task steal time
813 accounting. Time spent executing other tasks in parallel with
814 the current vCPU is discounted from the vCPU power. To account for
815 that, there can be a small performance impact.
816
817 If in doubt, say N here.
818
819config PARAVIRT_CLOCK
820 bool
97349135 821
4a362601
JK
822config JAILHOUSE_GUEST
823 bool "Jailhouse non-root cell support"
abde587b 824 depends on X86_64 && PCI
87e65d05 825 select X86_PM_TIMER
4a362601
JK
826 ---help---
827 This option allows to run Linux as guest in a Jailhouse non-root
828 cell. You can leave this option disabled if you only want to start
829 Jailhouse and run Linux afterwards in the root cell.
830
6276a074 831endif #HYPERVISOR_GUEST
97349135 832
506f1d07
SR
833source "arch/x86/Kconfig.cpu"
834
835config HPET_TIMER
3c2362e6 836 def_bool X86_64
506f1d07 837 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
838 ---help---
839 Use the IA-PC HPET (High Precision Event Timer) to manage
840 time in preference to the PIT and RTC, if a HPET is
841 present.
842 HPET is the next generation timer replacing legacy 8254s.
843 The HPET provides a stable time base on SMP
844 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
845 as it is off-chip. The interface used is documented
846 in the HPET spec, revision 1.
506f1d07 847
8f9ca475
IM
848 You can safely choose Y here. However, HPET will only be
849 activated if the platform and the BIOS support this feature.
850 Otherwise the 8254 will be used for timing services.
506f1d07 851
8f9ca475 852 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
853
854config HPET_EMULATE_RTC
3c2362e6 855 def_bool y
9d8af78b 856 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 857
bb24c471 858config APB_TIMER
933b9463
AC
859 def_bool y if X86_INTEL_MID
860 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 861 select DW_APB_TIMER
a0c3832a 862 depends on X86_INTEL_MID && SFI
bb24c471
JP
863 help
864 APB timer is the replacement for 8254, HPET on X86 MID platforms.
865 The APBT provides a stable time base on SMP
866 systems, unlike the TSC, but it is more expensive to access,
867 as it is off-chip. APB timers are always running regardless of CPU
868 C states, they are used as per CPU clockevent device when possible.
869
6a108a14 870# Mark as expert because too many people got it wrong.
506f1d07 871# The code disables itself when not needed.
7ae9392c
TP
872config DMI
873 default y
cf074402 874 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 875 bool "Enable DMI scanning" if EXPERT
8f9ca475 876 ---help---
7ae9392c
TP
877 Enabled scanning of DMI to identify machine quirks. Say Y
878 here unless you have verified that your setup is not
879 affected by entries in the DMI blacklist. Required by PNP
880 BIOS code.
881
506f1d07 882config GART_IOMMU
38901f1c 883 bool "Old AMD GART IOMMU support"
a4ce5a48 884 select IOMMU_HELPER
506f1d07 885 select SWIOTLB
23ac4ae8 886 depends on X86_64 && PCI && AMD_NB
8f9ca475 887 ---help---
ced3c42c
IM
888 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
889 GART based hardware IOMMUs.
890
891 The GART supports full DMA access for devices with 32-bit access
892 limitations, on systems with more than 3 GB. This is usually needed
893 for USB, sound, many IDE/SATA chipsets and some other devices.
894
895 Newer systems typically have a modern AMD IOMMU, supported via
896 the CONFIG_AMD_IOMMU=y config option.
897
898 In normal configurations this driver is only active when needed:
899 there's more than 3 GB of memory and the system contains a
900 32-bit limited device.
901
902 If unsure, say Y.
506f1d07
SR
903
904config CALGARY_IOMMU
905 bool "IBM Calgary IOMMU support"
a4ce5a48 906 select IOMMU_HELPER
506f1d07 907 select SWIOTLB
6ea30386 908 depends on X86_64 && PCI
8f9ca475 909 ---help---
506f1d07
SR
910 Support for hardware IOMMUs in IBM's xSeries x366 and x460
911 systems. Needed to run systems with more than 3GB of memory
912 properly with 32-bit PCI devices that do not support DAC
913 (Double Address Cycle). Calgary also supports bus level
914 isolation, where all DMAs pass through the IOMMU. This
915 prevents them from going anywhere except their intended
916 destination. This catches hard-to-find kernel bugs and
917 mis-behaving drivers and devices that do not use the DMA-API
918 properly to set up their DMA buffers. The IOMMU can be
919 turned off at boot time with the iommu=off parameter.
920 Normally the kernel will make the right choice by itself.
921 If unsure, say Y.
922
923config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
924 def_bool y
925 prompt "Should Calgary be enabled by default?"
506f1d07 926 depends on CALGARY_IOMMU
8f9ca475 927 ---help---
506f1d07
SR
928 Should Calgary be enabled by default? if you choose 'y', Calgary
929 will be used (if it exists). If you choose 'n', Calgary will not be
930 used even if it exists. If you choose 'n' and would like to use
931 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
932 If unsure, say Y.
506f1d07 933
1184dc2f 934config MAXSMP
ddb0c5a6 935 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 936 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 937 select CPUMASK_OFFSTACK
8f9ca475 938 ---help---
ddb0c5a6 939 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 940 If unsure, say N.
506f1d07 941
aec6487e
IM
942#
943# The maximum number of CPUs supported:
944#
945# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
946# and which can be configured interactively in the
947# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
948#
949# The ranges are different on 32-bit and 64-bit kernels, depending on
950# hardware capabilities and scalability features of the kernel.
951#
952# ( If MAXSMP is enabled we just use the highest possible value and disable
953# interactive configuration. )
954#
955
956config NR_CPUS_RANGE_BEGIN
a0d0bb4d 957 int
aec6487e
IM
958 default NR_CPUS_RANGE_END if MAXSMP
959 default 1 if !SMP
960 default 2
a0d0bb4d 961
aec6487e 962config NR_CPUS_RANGE_END
a0d0bb4d 963 int
aec6487e
IM
964 depends on X86_32
965 default 64 if SMP && X86_BIGSMP
966 default 8 if SMP && !X86_BIGSMP
967 default 1 if !SMP
a0d0bb4d 968
aec6487e 969config NR_CPUS_RANGE_END
a0d0bb4d 970 int
aec6487e
IM
971 depends on X86_64
972 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
973 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
974 default 1 if !SMP
a0d0bb4d 975
aec6487e 976config NR_CPUS_DEFAULT
a0d0bb4d
RD
977 int
978 depends on X86_32
aec6487e
IM
979 default 32 if X86_BIGSMP
980 default 8 if SMP
981 default 1 if !SMP
a0d0bb4d 982
aec6487e 983config NR_CPUS_DEFAULT
a0d0bb4d
RD
984 int
985 depends on X86_64
aec6487e
IM
986 default 8192 if MAXSMP
987 default 64 if SMP
988 default 1 if !SMP
a0d0bb4d 989
506f1d07 990config NR_CPUS
36f5101a 991 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
992 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
993 default NR_CPUS_DEFAULT
8f9ca475 994 ---help---
506f1d07 995 This allows you to specify the maximum number of CPUs which this
bb61ccc7 996 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 997 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
998 minimum value which makes sense is 2.
999
aec6487e
IM
1000 This is purely to save memory: each supported CPU adds about 8KB
1001 to the kernel image.
506f1d07
SR
1002
1003config SCHED_SMT
dbe73364 1004 def_bool y if SMP
506f1d07
SR
1005
1006config SCHED_MC
3c2362e6
HH
1007 def_bool y
1008 prompt "Multi-core scheduler support"
c8e56d20 1009 depends on SMP
8f9ca475 1010 ---help---
506f1d07
SR
1011 Multi-core scheduler support improves the CPU scheduler's decision
1012 making when dealing with multi-core CPU chips at a cost of slightly
1013 increased overhead in some places. If unsure say N here.
1014
de966cf4
TC
1015config SCHED_MC_PRIO
1016 bool "CPU core priorities scheduler support"
0a21fc12
IM
1017 depends on SCHED_MC && CPU_SUP_INTEL
1018 select X86_INTEL_PSTATE
1019 select CPU_FREQ
de966cf4 1020 default y
5e76b2ab 1021 ---help---
0a21fc12
IM
1022 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1023 core ordering determined at manufacturing time, which allows
1024 certain cores to reach higher turbo frequencies (when running
1025 single threaded workloads) than others.
de966cf4 1026
0a21fc12
IM
1027 Enabling this kernel feature teaches the scheduler about
1028 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1029 scheduler's CPU selection logic accordingly, so that higher
1030 overall system performance can be achieved.
de966cf4 1031
0a21fc12 1032 This feature will have no effect on CPUs without this feature.
de966cf4 1033
0a21fc12 1034 If unsure say Y here.
5e76b2ab 1035
30b8b006
TG
1036config UP_LATE_INIT
1037 def_bool y
ba360f88 1038 depends on !SMP && X86_LOCAL_APIC
30b8b006 1039
506f1d07 1040config X86_UP_APIC
50849eef
JB
1041 bool "Local APIC support on uniprocessors" if !PCI_MSI
1042 default PCI_MSI
38a1dfda 1043 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1044 ---help---
506f1d07
SR
1045 A local APIC (Advanced Programmable Interrupt Controller) is an
1046 integrated interrupt controller in the CPU. If you have a single-CPU
1047 system which has a processor with a local APIC, you can say Y here to
1048 enable and use it. If you say Y here even though your machine doesn't
1049 have a local APIC, then the kernel will still run with no slowdown at
1050 all. The local APIC supports CPU-generated self-interrupts (timer,
1051 performance counters), and the NMI watchdog which detects hard
1052 lockups.
1053
1054config X86_UP_IOAPIC
1055 bool "IO-APIC support on uniprocessors"
1056 depends on X86_UP_APIC
8f9ca475 1057 ---help---
506f1d07
SR
1058 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1059 SMP-capable replacement for PC-style interrupt controllers. Most
1060 SMP systems and many recent uniprocessor systems have one.
1061
1062 If you have a single-CPU system with an IO-APIC, you can say Y here
1063 to use it. If you say Y here even though your machine doesn't have
1064 an IO-APIC, then the kernel will still run with no slowdown at all.
1065
1066config X86_LOCAL_APIC
3c2362e6 1067 def_bool y
0dbc6078 1068 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1069 select IRQ_DOMAIN_HIERARCHY
52f518a3 1070 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1071
1072config X86_IO_APIC
b1da1e71
JB
1073 def_bool y
1074 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1075
41b9eb26
SA
1076config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1077 bool "Reroute for broken boot IRQs"
41b9eb26 1078 depends on X86_IO_APIC
8f9ca475 1079 ---help---
41b9eb26
SA
1080 This option enables a workaround that fixes a source of
1081 spurious interrupts. This is recommended when threaded
1082 interrupt handling is used on systems where the generation of
1083 superfluous "boot interrupts" cannot be disabled.
1084
1085 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1086 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1087 kernel does during interrupt handling). On chipsets where this
1088 boot IRQ generation cannot be disabled, this workaround keeps
1089 the original IRQ line masked so that only the equivalent "boot
1090 IRQ" is delivered to the CPUs. The workaround also tells the
1091 kernel to set up the IRQ handler on the boot IRQ line. In this
1092 way only one interrupt is delivered to the kernel. Otherwise
1093 the spurious second interrupt may cause the kernel to bring
1094 down (vital) interrupt lines.
1095
1096 Only affects "broken" chipsets. Interrupt sharing may be
1097 increased on these systems.
1098
506f1d07 1099config X86_MCE
bab9bc65 1100 bool "Machine Check / overheating reporting"
648ed940 1101 select GENERIC_ALLOCATOR
e57dbaf7 1102 default y
506f1d07 1103 ---help---
bab9bc65
AK
1104 Machine Check support allows the processor to notify the
1105 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1106 The action the kernel takes depends on the severity of the problem,
bab9bc65 1107 ranging from warning messages to halting the machine.
4efc0670 1108
5de97c9f
TL
1109config X86_MCELOG_LEGACY
1110 bool "Support for deprecated /dev/mcelog character device"
1111 depends on X86_MCE
1112 ---help---
1113 Enable support for /dev/mcelog which is needed by the old mcelog
1114 userspace logging daemon. Consider switching to the new generation
1115 rasdaemon solution.
1116
506f1d07 1117config X86_MCE_INTEL
3c2362e6
HH
1118 def_bool y
1119 prompt "Intel MCE features"
c1ebf835 1120 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1121 ---help---
506f1d07
SR
1122 Additional support for intel specific MCE features such as
1123 the thermal monitor.
1124
1125config X86_MCE_AMD
3c2362e6
HH
1126 def_bool y
1127 prompt "AMD MCE features"
f5382de9 1128 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1129 ---help---
506f1d07
SR
1130 Additional support for AMD specific MCE features such as
1131 the DRAM Error Threshold.
1132
4efc0670 1133config X86_ANCIENT_MCE
6fc108a0 1134 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1135 depends on X86_32 && X86_MCE
cd13adcc
HS
1136 ---help---
1137 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1138 systems. These typically need to be enabled explicitly on the command
cd13adcc 1139 line.
4efc0670 1140
b2762686
AK
1141config X86_MCE_THRESHOLD
1142 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1143 def_bool y
b2762686 1144
ea149b36 1145config X86_MCE_INJECT
bc8e80d5 1146 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1147 tristate "Machine check injector support"
1148 ---help---
1149 Provide support for injecting machine checks for testing purposes.
1150 If you don't know what a machine check is and you don't do kernel
1151 QA it is safe to say n.
1152
4efc0670
AK
1153config X86_THERMAL_VECTOR
1154 def_bool y
5bb38adc 1155 depends on X86_MCE_INTEL
4efc0670 1156
07dc900e 1157source "arch/x86/events/Kconfig"
e633c65a 1158
5aef51c3 1159config X86_LEGACY_VM86
1e642812 1160 bool "Legacy VM86 support"
506f1d07 1161 depends on X86_32
8f9ca475 1162 ---help---
5aef51c3
AL
1163 This option allows user programs to put the CPU into V8086
1164 mode, which is an 80286-era approximation of 16-bit real mode.
1165
1166 Some very old versions of X and/or vbetool require this option
1167 for user mode setting. Similarly, DOSEMU will use it if
1168 available to accelerate real mode DOS programs. However, any
1169 recent version of DOSEMU, X, or vbetool should be fully
1170 functional even without kernel VM86 support, as they will all
1e642812
IM
1171 fall back to software emulation. Nevertheless, if you are using
1172 a 16-bit DOS program where 16-bit performance matters, vm86
1173 mode might be faster than emulation and you might want to
1174 enable this option.
5aef51c3 1175
1e642812
IM
1176 Note that any app that works on a 64-bit kernel is unlikely to
1177 need this option, as 64-bit kernels don't, and can't, support
1178 V8086 mode. This option is also unrelated to 16-bit protected
1179 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1180
1e642812
IM
1181 Enabling this option increases the complexity of the kernel
1182 and slows down exception handling a tiny bit.
5aef51c3 1183
1e642812 1184 If unsure, say N here.
5aef51c3
AL
1185
1186config VM86
1187 bool
1188 default X86_LEGACY_VM86
34273f41
PA
1189
1190config X86_16BIT
1191 bool "Enable support for 16-bit segments" if EXPERT
1192 default y
a5b9e5a2 1193 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1194 ---help---
1195 This option is required by programs like Wine to run 16-bit
1196 protected mode legacy code on x86 processors. Disabling
1197 this option saves about 300 bytes on i386, or around 6K text
1198 plus 16K runtime memory on x86-64,
1199
1200config X86_ESPFIX32
1201 def_bool y
1202 depends on X86_16BIT && X86_32
506f1d07 1203
197725de
PA
1204config X86_ESPFIX64
1205 def_bool y
34273f41 1206 depends on X86_16BIT && X86_64
506f1d07 1207
1ad83c85
AL
1208config X86_VSYSCALL_EMULATION
1209 bool "Enable vsyscall emulation" if EXPERT
1210 default y
1211 depends on X86_64
1212 ---help---
1213 This enables emulation of the legacy vsyscall page. Disabling
1214 it is roughly equivalent to booting with vsyscall=none, except
1215 that it will also disable the helpful warning if a program
1216 tries to use a vsyscall. With this option set to N, offending
1217 programs will just segfault, citing addresses of the form
1218 0xffffffffff600?00.
1219
1220 This option is required by many programs built before 2013, and
1221 care should be used even with newer programs if set to N.
1222
1223 Disabling this option saves about 7K of kernel size and
1224 possibly 4K of additional runtime pagetable memory.
1225
506f1d07
SR
1226config TOSHIBA
1227 tristate "Toshiba Laptop support"
1228 depends on X86_32
1229 ---help---
1230 This adds a driver to safely access the System Management Mode of
1231 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1232 not work on models with a Phoenix BIOS. The System Management Mode
1233 is used to set the BIOS and power saving options on Toshiba portables.
1234
1235 For information on utilities to make use of this driver see the
1236 Toshiba Linux utilities web site at:
1237 <http://www.buzzard.org.uk/toshiba/>.
1238
1239 Say Y if you intend to run this kernel on a Toshiba portable.
1240 Say N otherwise.
1241
1242config I8K
039ae585 1243 tristate "Dell i8k legacy laptop support"
949a9d70 1244 select HWMON
039ae585 1245 select SENSORS_DELL_SMM
506f1d07 1246 ---help---
039ae585
PR
1247 This option enables legacy /proc/i8k userspace interface in hwmon
1248 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1249 temperature and allows controlling fan speeds of Dell laptops via
1250 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1251 it reports also power and hotkey status. For fan speed control is
1252 needed userspace package i8kutils.
1253
1254 Say Y if you intend to run this kernel on old Dell laptops or want to
1255 use userspace package i8kutils.
506f1d07
SR
1256 Say N otherwise.
1257
1258config X86_REBOOTFIXUPS
9ba16087
JB
1259 bool "Enable X86 board specific fixups for reboot"
1260 depends on X86_32
506f1d07
SR
1261 ---help---
1262 This enables chipset and/or board specific fixups to be done
1263 in order to get reboot to work correctly. This is only needed on
1264 some combinations of hardware and BIOS. The symptom, for which
1265 this config is intended, is when reboot ends with a stalled/hung
1266 system.
1267
1268 Currently, the only fixup is for the Geode machines using
5e3a77e9 1269 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1270
1271 Say Y if you want to enable the fixup. Currently, it's safe to
1272 enable this option even if you don't need it.
1273 Say N otherwise.
1274
1275config MICROCODE
9a2bc335
BP
1276 bool "CPU microcode loading support"
1277 default y
80030e3d 1278 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1279 select FW_LOADER
1280 ---help---
1281 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1282 Intel and AMD processors. The Intel support is for the IA32 family,
1283 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1284 AMD support is for families 0x10 and later. You will obviously need
1285 the actual microcode binary data itself which is not shipped with
1286 the Linux kernel.
1287
1288 The preferred method to load microcode from a detached initrd is described
1897a969 1289 in Documentation/x86/microcode.txt. For that you need to enable
5f9c01aa
BP
1290 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1291 initrd for microcode blobs.
1292
c508c46e
BG
1293 In addition, you can build the microcode into the kernel. For that you
1294 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1295 config option.
506f1d07 1296
8d86f390 1297config MICROCODE_INTEL
e43f6e67 1298 bool "Intel microcode loading support"
8f9ca475
IM
1299 depends on MICROCODE
1300 default MICROCODE
1301 select FW_LOADER
1302 ---help---
1303 This options enables microcode patch loading support for Intel
1304 processors.
1305
b8989db9
A
1306 For the current Intel microcode data package go to
1307 <https://downloadcenter.intel.com> and search for
1308 'Linux Processor Microcode Data File'.
8d86f390 1309
80cc9f10 1310config MICROCODE_AMD
e43f6e67 1311 bool "AMD microcode loading support"
8f9ca475
IM
1312 depends on MICROCODE
1313 select FW_LOADER
1314 ---help---
1315 If you select this option, microcode patch loading support for AMD
1316 processors will be enabled.
80cc9f10 1317
8f9ca475 1318config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1319 bool "Ancient loading interface (DEPRECATED)"
1320 default n
506f1d07 1321 depends on MICROCODE
c02f48e0
BP
1322 ---help---
1323 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1324 which was used by userspace tools like iucode_tool and microcode.ctl.
1325 It is inadequate because it runs too late to be able to properly
1326 load microcode on a machine and it needs special tools. Instead, you
1327 should've switched to the early loading method with the initrd or
1328 builtin microcode by now: Documentation/x86/microcode.txt
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
5c280cf6
TG
1491config X86_CPA_STATISTICS
1492 bool "Enable statistic for Change Page Attribute"
1493 depends on DEBUG_FS
1494 ---help---
1495 Expose statistics about the Change Page Attribute mechanims, which
a943245a 1496 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1497 page mappings when mapping protections are changed.
1498
7744ccdb
TL
1499config ARCH_HAS_MEM_ENCRYPT
1500 def_bool y
1501
1502config AMD_MEM_ENCRYPT
1503 bool "AMD Secure Memory Encryption (SME) support"
1504 depends on X86_64 && CPU_SUP_AMD
94d49eb3 1505 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1506 select ARCH_USE_MEMREMAP_PROT
7744ccdb
TL
1507 ---help---
1508 Say yes to enable support for the encryption of system memory.
1509 This requires an AMD processor that supports Secure Memory
1510 Encryption (SME).
1511
1512config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1513 bool "Activate AMD Secure Memory Encryption (SME) by default"
1514 default y
1515 depends on AMD_MEM_ENCRYPT
1516 ---help---
1517 Say yes to have system memory encrypted by default if running on
1518 an AMD processor that supports Secure Memory Encryption (SME).
1519
1520 If set to Y, then the encryption of system memory can be
1521 deactivated with the mem_encrypt=off command line option.
1522
1523 If set to N, then the encryption of system memory can be
1524 activated with the mem_encrypt=on command line option.
1525
506f1d07
SR
1526# Common NUMA Features
1527config NUMA
fd51b2d7 1528 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1529 depends on SMP
b5660ba7
PA
1530 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1531 default y if X86_BIGSMP
8f9ca475 1532 ---help---
506f1d07 1533 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1534
506f1d07
SR
1535 The kernel will try to allocate memory used by a CPU on the
1536 local memory controller of the CPU and add some more
1537 NUMA awareness to the kernel.
1538
c280ea5e 1539 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1540 (or later), AMD Opteron, or EM64T NUMA.
1541
b5660ba7 1542 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1543 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1544
1545 Otherwise, you should say N.
506f1d07 1546
eec1d4fa 1547config AMD_NUMA
3c2362e6
HH
1548 def_bool y
1549 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1550 depends on X86_64 && NUMA && PCI
8f9ca475 1551 ---help---
eec1d4fa
HR
1552 Enable AMD NUMA node topology detection. You should say Y here if
1553 you have a multi processor AMD system. This uses an old method to
1554 read the NUMA configuration directly from the builtin Northbridge
1555 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1556 which also takes priority if both are compiled in.
506f1d07
SR
1557
1558config X86_64_ACPI_NUMA
3c2362e6
HH
1559 def_bool y
1560 prompt "ACPI NUMA detection"
506f1d07
SR
1561 depends on X86_64 && NUMA && ACPI && PCI
1562 select ACPI_NUMA
8f9ca475 1563 ---help---
506f1d07
SR
1564 Enable ACPI SRAT based node topology detection.
1565
6ec6e0d9
SS
1566# Some NUMA nodes have memory ranges that span
1567# other nodes. Even though a pfn is valid and
1568# between a node's start and end pfns, it may not
1569# reside on that node. See memmap_init_zone()
1570# for details.
1571config NODES_SPAN_OTHER_NODES
1572 def_bool y
1573 depends on X86_64_ACPI_NUMA
1574
506f1d07
SR
1575config NUMA_EMU
1576 bool "NUMA emulation"
1b7e03ef 1577 depends on NUMA
8f9ca475 1578 ---help---
506f1d07
SR
1579 Enable NUMA emulation. A flat machine will be split
1580 into virtual nodes when booted with "numa=fake=N", where N is the
1581 number of nodes. This is only useful for debugging.
1582
1583config NODES_SHIFT
d25e26b6 1584 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1585 range 1 10
1586 default "10" if MAXSMP
506f1d07 1587 default "6" if X86_64
506f1d07
SR
1588 default "3"
1589 depends on NEED_MULTIPLE_NODES
8f9ca475 1590 ---help---
1184dc2f 1591 Specify the maximum number of NUMA Nodes available on the target
692105b8 1592 system. Increases memory reserved to accommodate various tables.
506f1d07 1593
506f1d07 1594config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1595 def_bool y
506f1d07 1596 depends on X86_32 && DISCONTIGMEM
506f1d07 1597
506f1d07
SR
1598config ARCH_FLATMEM_ENABLE
1599 def_bool y
3b16651f 1600 depends on X86_32 && !NUMA
506f1d07
SR
1601
1602config ARCH_DISCONTIGMEM_ENABLE
2792107d 1603 def_bool n
b263295d 1604 depends on NUMA && X86_32
2792107d 1605 depends on BROKEN
b263295d 1606
506f1d07
SR
1607config ARCH_SPARSEMEM_ENABLE
1608 def_bool y
6ea30386 1609 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1610 select SPARSEMEM_STATIC if X86_32
1611 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1612
3b16651f 1613config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1614 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1615
506f1d07
SR
1616config ARCH_SELECT_MEMORY_MODEL
1617 def_bool y
b263295d 1618 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1619
1620config ARCH_MEMORY_PROBE
a0842b70 1621 bool "Enable sysfs memory/probe interface"
3120e25e 1622 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1623 help
1624 This option enables a sysfs memory/probe interface for testing.
1625 See Documentation/memory-hotplug.txt for more information.
1626 If you are unsure how to answer this question, answer N.
506f1d07 1627
3b16651f
TH
1628config ARCH_PROC_KCORE_TEXT
1629 def_bool y
1630 depends on X86_64 && PROC_KCORE
1631
a29815a3
AK
1632config ILLEGAL_POINTER_VALUE
1633 hex
1634 default 0 if X86_32
1635 default 0xdead000000000000 if X86_64
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
8636a1f9 1970source "kernel/Kconfig.hz"
506f1d07
SR
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
bebd024e 2210 def_bool y
40b31360 2211 depends on SMP
506f1d07 2212
80aa1dff
FY
2213config BOOTPARAM_HOTPLUG_CPU0
2214 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2215 depends on HOTPLUG_CPU
80aa1dff
FY
2216 ---help---
2217 Set whether default state of cpu0_hotpluggable is on or off.
2218
2219 Say Y here to enable CPU0 hotplug by default. If this switch
2220 is turned on, there is no need to give cpu0_hotplug kernel
2221 parameter and the CPU0 hotplug feature is enabled by default.
2222
2223 Please note: there are two known CPU0 dependencies if you want
2224 to enable the CPU0 hotplug feature either by this switch or by
2225 cpu0_hotplug kernel parameter.
2226
2227 First, resume from hibernate or suspend always starts from CPU0.
2228 So hibernate and suspend are prevented if CPU0 is offline.
2229
2230 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2231 offline if any interrupt can not migrate out of CPU0. There may
2232 be other CPU0 dependencies.
2233
2234 Please make sure the dependencies are under your control before
2235 you enable this feature.
2236
2237 Say N if you don't want to enable CPU0 hotplug feature by default.
2238 You still can enable the CPU0 hotplug feature at boot by kernel
2239 parameter cpu0_hotplug.
2240
a71c8bc5
FY
2241config DEBUG_HOTPLUG_CPU0
2242 def_bool n
2243 prompt "Debug CPU0 hotplug"
2c922cd0 2244 depends on HOTPLUG_CPU
a71c8bc5
FY
2245 ---help---
2246 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2247 soon as possible and boots up userspace with CPU0 offlined. User
2248 can online CPU0 back after boot time.
2249
2250 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2251 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2252 compilation or giving cpu0_hotplug kernel parameter at boot.
2253
2254 If unsure, say N.
2255
506f1d07 2256config COMPAT_VDSO
b0b49f26
AL
2257 def_bool n
2258 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2259 depends on COMPAT_32
8f9ca475 2260 ---help---
b0b49f26
AL
2261 Certain buggy versions of glibc will crash if they are
2262 presented with a 32-bit vDSO that is not mapped at the address
2263 indicated in its segment table.
e84446de 2264
b0b49f26
AL
2265 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2266 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2267 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2268 the only released version with the bug, but OpenSUSE 9
2269 contains a buggy "glibc 2.3.2".
506f1d07 2270
b0b49f26
AL
2271 The symptom of the bug is that everything crashes on startup, saying:
2272 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2273
2274 Saying Y here changes the default value of the vdso32 boot
2275 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2276 This works around the glibc bug but hurts performance.
2277
2278 If unsure, say N: if you are compiling your own kernel, you
2279 are unlikely to be using a buggy version of glibc.
506f1d07 2280
3dc33bd3
KC
2281choice
2282 prompt "vsyscall table for legacy applications"
2283 depends on X86_64
2284 default LEGACY_VSYSCALL_EMULATE
2285 help
2286 Legacy user code that does not know how to find the vDSO expects
2287 to be able to issue three syscalls by calling fixed addresses in
2288 kernel space. Since this location is not randomized with ASLR,
2289 it can be used to assist security vulnerability exploitation.
2290
2291 This setting can be changed at boot time via the kernel command
076ca272 2292 line parameter vsyscall=[emulate|none].
3dc33bd3
KC
2293
2294 On a system with recent enough glibc (2.14 or newer) and no
2295 static binaries, you can say None without a performance penalty
2296 to improve security.
2297
2298 If unsure, select "Emulate".
2299
3dc33bd3
KC
2300 config LEGACY_VSYSCALL_EMULATE
2301 bool "Emulate"
2302 help
2303 The kernel traps and emulates calls into the fixed
2304 vsyscall address mapping. This makes the mapping
2305 non-executable, but it still contains known contents,
2306 which could be used in certain rare security vulnerability
2307 exploits. This configuration is recommended when userspace
2308 still uses the vsyscall area.
2309
2310 config LEGACY_VSYSCALL_NONE
2311 bool "None"
2312 help
2313 There will be no vsyscall mapping at all. This will
2314 eliminate any risk of ASLR bypass due to the vsyscall
2315 fixed address mapping. Attempts to use the vsyscalls
2316 will be reported to dmesg, so that either old or
2317 malicious userspace programs can be identified.
2318
2319endchoice
2320
516cbf37
TB
2321config CMDLINE_BOOL
2322 bool "Built-in kernel command line"
8f9ca475 2323 ---help---
516cbf37
TB
2324 Allow for specifying boot arguments to the kernel at
2325 build time. On some systems (e.g. embedded ones), it is
2326 necessary or convenient to provide some or all of the
2327 kernel boot arguments with the kernel itself (that is,
2328 to not rely on the boot loader to provide them.)
2329
2330 To compile command line arguments into the kernel,
2331 set this option to 'Y', then fill in the
69711ca1 2332 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2333
2334 Systems with fully functional boot loaders (i.e. non-embedded)
2335 should leave this option set to 'N'.
2336
2337config CMDLINE
2338 string "Built-in kernel command string"
2339 depends on CMDLINE_BOOL
2340 default ""
8f9ca475 2341 ---help---
516cbf37
TB
2342 Enter arguments here that should be compiled into the kernel
2343 image and used at boot time. If the boot loader provides a
2344 command line at boot time, it is appended to this string to
2345 form the full kernel command line, when the system boots.
2346
2347 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2348 change this behavior.
2349
2350 In most cases, the command line (whether built-in or provided
2351 by the boot loader) should specify the device for the root
2352 file system.
2353
2354config CMDLINE_OVERRIDE
2355 bool "Built-in command line overrides boot loader arguments"
516cbf37 2356 depends on CMDLINE_BOOL
8f9ca475 2357 ---help---
516cbf37
TB
2358 Set this option to 'Y' to have the kernel ignore the boot loader
2359 command line, and use ONLY the built-in command line.
2360
2361 This is used to work around broken boot loaders. This should
2362 be set to 'N' under normal conditions.
2363
a5b9e5a2
AL
2364config MODIFY_LDT_SYSCALL
2365 bool "Enable the LDT (local descriptor table)" if EXPERT
2366 default y
2367 ---help---
2368 Linux can allow user programs to install a per-process x86
2369 Local Descriptor Table (LDT) using the modify_ldt(2) system
2370 call. This is required to run 16-bit or segmented code such as
2371 DOSEMU or some Wine programs. It is also used by some very old
2372 threading libraries.
2373
2374 Enabling this feature adds a small amount of overhead to
2375 context switches and increases the low-level kernel attack
2376 surface. Disabling it removes the modify_ldt(2) system call.
2377
2378 Saying 'N' here may make sense for embedded or server kernels.
2379
b700e7f0
SJ
2380source "kernel/livepatch/Kconfig"
2381
506f1d07
SR
2382endmenu
2383
3072e413
MH
2384config ARCH_HAS_ADD_PAGES
2385 def_bool y
2386 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2387
506f1d07
SR
2388config ARCH_ENABLE_MEMORY_HOTPLUG
2389 def_bool y
2390 depends on X86_64 || (X86_32 && HIGHMEM)
2391
35551053
GH
2392config ARCH_ENABLE_MEMORY_HOTREMOVE
2393 def_bool y
2394 depends on MEMORY_HOTPLUG
2395
e534c7c5 2396config USE_PERCPU_NUMA_NODE_ID
645a7919 2397 def_bool y
e534c7c5
LS
2398 depends on NUMA
2399
9491846f
KS
2400config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2401 def_bool y
2402 depends on X86_64 || X86_PAE
2403
c177c81e
NH
2404config ARCH_ENABLE_HUGEPAGE_MIGRATION
2405 def_bool y
2406 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2407
9c670ea3
NH
2408config ARCH_ENABLE_THP_MIGRATION
2409 def_bool y
2410 depends on X86_64 && TRANSPARENT_HUGEPAGE
2411
da85f865 2412menu "Power management and ACPI options"
e279b6c1
SR
2413
2414config ARCH_HIBERNATION_HEADER
3c2362e6 2415 def_bool y
44556530 2416 depends on HIBERNATION
e279b6c1
SR
2417
2418source "kernel/power/Kconfig"
2419
2420source "drivers/acpi/Kconfig"
2421
efafc8b2
FT
2422source "drivers/sfi/Kconfig"
2423
a6b68076 2424config X86_APM_BOOT
6fc108a0 2425 def_bool y
282e5aab 2426 depends on APM
a6b68076 2427
e279b6c1
SR
2428menuconfig APM
2429 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2430 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2431 ---help---
2432 APM is a BIOS specification for saving power using several different
2433 techniques. This is mostly useful for battery powered laptops with
2434 APM compliant BIOSes. If you say Y here, the system time will be
2435 reset after a RESUME operation, the /proc/apm device will provide
2436 battery status information, and user-space programs will receive
2437 notification of APM "events" (e.g. battery status change).
2438
2439 If you select "Y" here, you can disable actual use of the APM
2440 BIOS by passing the "apm=off" option to the kernel at boot time.
2441
2442 Note that the APM support is almost completely disabled for
2443 machines with more than one CPU.
2444
2445 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2446 and more information, read <file:Documentation/power/apm-acpi.txt>
2447 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2448 <http://www.tldp.org/docs.html#howto>.
2449
2450 This driver does not spin down disk drives (see the hdparm(8)
2451 manpage ("man 8 hdparm") for that), and it doesn't turn off
2452 VESA-compliant "green" monitors.
2453
2454 This driver does not support the TI 4000M TravelMate and the ACER
2455 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2456 desktop machines also don't have compliant BIOSes, and this driver
2457 may cause those machines to panic during the boot phase.
2458
2459 Generally, if you don't have a battery in your machine, there isn't
2460 much point in using this driver and you should say N. If you get
2461 random kernel OOPSes or reboots that don't seem to be related to
2462 anything, try disabling/enabling this option (or disabling/enabling
2463 APM in your BIOS).
2464
2465 Some other things you should try when experiencing seemingly random,
2466 "weird" problems:
2467
2468 1) make sure that you have enough swap space and that it is
2469 enabled.
2470 2) pass the "no-hlt" option to the kernel
2471 3) switch on floating point emulation in the kernel and pass
2472 the "no387" option to the kernel
2473 4) pass the "floppy=nodma" option to the kernel
2474 5) pass the "mem=4M" option to the kernel (thereby disabling
2475 all but the first 4 MB of RAM)
2476 6) make sure that the CPU is not over clocked.
2477 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2478 8) disable the cache from your BIOS settings
2479 9) install a fan for the video card or exchange video RAM
2480 10) install a better fan for the CPU
2481 11) exchange RAM chips
2482 12) exchange the motherboard.
2483
2484 To compile this driver as a module, choose M here: the
2485 module will be called apm.
2486
2487if APM
2488
2489config APM_IGNORE_USER_SUSPEND
2490 bool "Ignore USER SUSPEND"
8f9ca475 2491 ---help---
e279b6c1
SR
2492 This option will ignore USER SUSPEND requests. On machines with a
2493 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2494 series notebooks, it is necessary to say Y because of a BIOS bug.
2495
2496config APM_DO_ENABLE
2497 bool "Enable PM at boot time"
2498 ---help---
2499 Enable APM features at boot time. From page 36 of the APM BIOS
2500 specification: "When disabled, the APM BIOS does not automatically
2501 power manage devices, enter the Standby State, enter the Suspend
2502 State, or take power saving steps in response to CPU Idle calls."
2503 This driver will make CPU Idle calls when Linux is idle (unless this
2504 feature is turned off -- see "Do CPU IDLE calls", below). This
2505 should always save battery power, but more complicated APM features
2506 will be dependent on your BIOS implementation. You may need to turn
2507 this option off if your computer hangs at boot time when using APM
2508 support, or if it beeps continuously instead of suspending. Turn
2509 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2510 T400CDT. This is off by default since most machines do fine without
2511 this feature.
2512
2513config APM_CPU_IDLE
dd8af076 2514 depends on CPU_IDLE
e279b6c1 2515 bool "Make CPU Idle calls when idle"
8f9ca475 2516 ---help---
e279b6c1
SR
2517 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2518 On some machines, this can activate improved power savings, such as
2519 a slowed CPU clock rate, when the machine is idle. These idle calls
2520 are made after the idle loop has run for some length of time (e.g.,
2521 333 mS). On some machines, this will cause a hang at boot time or
2522 whenever the CPU becomes idle. (On machines with more than one CPU,
2523 this option does nothing.)
2524
2525config APM_DISPLAY_BLANK
2526 bool "Enable console blanking using APM"
8f9ca475 2527 ---help---
e279b6c1
SR
2528 Enable console blanking using the APM. Some laptops can use this to
2529 turn off the LCD backlight when the screen blanker of the Linux
2530 virtual console blanks the screen. Note that this is only used by
2531 the virtual console screen blanker, and won't turn off the backlight
2532 when using the X Window system. This also doesn't have anything to
2533 do with your VESA-compliant power-saving monitor. Further, this
2534 option doesn't work for all laptops -- it might not turn off your
2535 backlight at all, or it might print a lot of errors to the console,
2536 especially if you are using gpm.
2537
2538config APM_ALLOW_INTS
2539 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2540 ---help---
e279b6c1
SR
2541 Normally we disable external interrupts while we are making calls to
2542 the APM BIOS as a measure to lessen the effects of a badly behaving
2543 BIOS implementation. The BIOS should reenable interrupts if it
2544 needs to. Unfortunately, some BIOSes do not -- especially those in
2545 many of the newer IBM Thinkpads. If you experience hangs when you
2546 suspend, try setting this to Y. Otherwise, say N.
2547
e279b6c1
SR
2548endif # APM
2549
bb0a56ec 2550source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2551
2552source "drivers/cpuidle/Kconfig"
2553
27471fdb
AH
2554source "drivers/idle/Kconfig"
2555
e279b6c1
SR
2556endmenu
2557
2558
2559menu "Bus options (PCI etc.)"
2560
e279b6c1
SR
2561choice
2562 prompt "PCI access mode"
efefa6f6 2563 depends on X86_32 && PCI
e279b6c1
SR
2564 default PCI_GOANY
2565 ---help---
2566 On PCI systems, the BIOS can be used to detect the PCI devices and
2567 determine their configuration. However, some old PCI motherboards
2568 have BIOS bugs and may crash if this is done. Also, some embedded
2569 PCI-based systems don't have any BIOS at all. Linux can also try to
2570 detect the PCI hardware directly without using the BIOS.
2571
2572 With this option, you can specify how Linux should detect the
2573 PCI devices. If you choose "BIOS", the BIOS will be used,
2574 if you choose "Direct", the BIOS won't be used, and if you
2575 choose "MMConfig", then PCI Express MMCONFIG will be used.
2576 If you choose "Any", the kernel will try MMCONFIG, then the
2577 direct access method and falls back to the BIOS if that doesn't
2578 work. If unsure, go with the default, which is "Any".
2579
2580config PCI_GOBIOS
2581 bool "BIOS"
2582
2583config PCI_GOMMCONFIG
2584 bool "MMConfig"
2585
2586config PCI_GODIRECT
2587 bool "Direct"
2588
3ef0e1f8 2589config PCI_GOOLPC
76fb6570 2590 bool "OLPC XO-1"
3ef0e1f8
AS
2591 depends on OLPC
2592
2bdd1b03
AS
2593config PCI_GOANY
2594 bool "Any"
2595
e279b6c1
SR
2596endchoice
2597
2598config PCI_BIOS
3c2362e6 2599 def_bool y
efefa6f6 2600 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2601
2602# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2603config PCI_DIRECT
3c2362e6 2604 def_bool y
0aba496f 2605 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2606
2607config PCI_MMCONFIG
b45c9f36
JK
2608 bool "Support mmconfig PCI config space access" if X86_64
2609 default y
8364e1f8 2610 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2611 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2612
3ef0e1f8 2613config PCI_OLPC
2bdd1b03
AS
2614 def_bool y
2615 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2616
b5401a96
AN
2617config PCI_XEN
2618 def_bool y
2619 depends on PCI && XEN
2620 select SWIOTLB_XEN
2621
8364e1f8
JK
2622config MMCONF_FAM10H
2623 def_bool y
2624 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2625
3f6ea84a 2626config PCI_CNB20LE_QUIRK
6a108a14 2627 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2628 depends on PCI
3f6ea84a
IS
2629 help
2630 Read the PCI windows out of the CNB20LE host bridge. This allows
2631 PCI hotplug to work on systems with the CNB20LE chipset which do
2632 not have ACPI.
2633
64a5fed6
BH
2634 There's no public spec for this chipset, and this functionality
2635 is known to be incomplete.
2636
2637 You should say N unless you know you need this.
2638
3a495511 2639config ISA_BUS
17a2a129 2640 bool "ISA bus support on modern systems" if EXPERT
3a495511 2641 help
17a2a129
WBG
2642 Expose ISA bus device drivers and options available for selection and
2643 configuration. Enable this option if your target machine has an ISA
2644 bus. ISA is an older system, displaced by PCI and newer bus
2645 architectures -- if your target machine is modern, it probably does
2646 not have an ISA bus.
3a495511
WBG
2647
2648 If unsure, say N.
2649
1c00f016 2650# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2651config ISA_DMA_API
1c00f016
DR
2652 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2653 default y
2654 help
2655 Enables ISA-style DMA support for devices requiring such controllers.
2656 If unsure, say Y.
e279b6c1 2657
51e68d05
LT
2658if X86_32
2659
e279b6c1
SR
2660config ISA
2661 bool "ISA support"
8f9ca475 2662 ---help---
e279b6c1
SR
2663 Find out whether you have ISA slots on your motherboard. ISA is the
2664 name of a bus system, i.e. the way the CPU talks to the other stuff
2665 inside your box. Other bus systems are PCI, EISA, MicroChannel
2666 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2667 newer boards don't support it. If you have ISA, say Y, otherwise N.
2668
e279b6c1
SR
2669config SCx200
2670 tristate "NatSemi SCx200 support"
8f9ca475 2671 ---help---
e279b6c1
SR
2672 This provides basic support for National Semiconductor's
2673 (now AMD's) Geode processors. The driver probes for the
2674 PCI-IDs of several on-chip devices, so its a good dependency
2675 for other scx200_* drivers.
2676
2677 If compiled as a module, the driver is named scx200.
2678
2679config SCx200HR_TIMER
2680 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2681 depends on SCx200
e279b6c1 2682 default y
8f9ca475 2683 ---help---
e279b6c1
SR
2684 This driver provides a clocksource built upon the on-chip
2685 27MHz high-resolution timer. Its also a workaround for
2686 NSC Geode SC-1100's buggy TSC, which loses time when the
2687 processor goes idle (as is done by the scheduler). The
2688 other workaround is idle=poll boot option.
2689
3ef0e1f8
AS
2690config OLPC
2691 bool "One Laptop Per Child support"
54008979 2692 depends on !X86_PAE
3c554946 2693 select GPIOLIB
dc3119e7 2694 select OF
45bb1674 2695 select OF_PROMTREE
b4e51854 2696 select IRQ_DOMAIN
8f9ca475 2697 ---help---
3ef0e1f8
AS
2698 Add support for detecting the unique features of the OLPC
2699 XO hardware.
2700
a3128588
DD
2701config OLPC_XO1_PM
2702 bool "OLPC XO-1 Power Management"
fa112cf1 2703 depends on OLPC && MFD_CS5535=y && PM_SLEEP
bf1ebf00 2704 ---help---
97c4cb71 2705 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2706
cfee9597
DD
2707config OLPC_XO1_RTC
2708 bool "OLPC XO-1 Real Time Clock"
2709 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2710 ---help---
2711 Add support for the XO-1 real time clock, which can be used as a
2712 programmable wakeup source.
2713
7feda8e9
DD
2714config OLPC_XO1_SCI
2715 bool "OLPC XO-1 SCI extras"
92e830f2 2716 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2717 depends on INPUT=y
d8d01a63 2718 select POWER_SUPPLY
7feda8e9
DD
2719 ---help---
2720 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2721 - EC-driven system wakeups
7feda8e9 2722 - Power button
7bc74b3d 2723 - Ebook switch
2cf2baea 2724 - Lid switch
e1040ac6
DD
2725 - AC adapter status updates
2726 - Battery status updates
7feda8e9 2727
a0f30f59
DD
2728config OLPC_XO15_SCI
2729 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2730 depends on OLPC && ACPI
2731 select POWER_SUPPLY
a0f30f59
DD
2732 ---help---
2733 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2734 - EC-driven system wakeups
2735 - AC adapter status updates
2736 - Battery status updates
bf1ebf00 2737
d4f3e350
EW
2738config ALIX
2739 bool "PCEngines ALIX System Support (LED setup)"
2740 select GPIOLIB
2741 ---help---
2742 This option enables system support for the PCEngines ALIX.
2743 At present this just sets up LEDs for GPIO control on
2744 ALIX2/3/6 boards. However, other system specific setup should
2745 get added here.
2746
2747 Note: You must still enable the drivers for GPIO and LED support
2748 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2749
2750 Note: You have to set alix.force=1 for boards with Award BIOS.
2751
da4e3302
PP
2752config NET5501
2753 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2754 select GPIOLIB
2755 ---help---
2756 This option enables system support for the Soekris Engineering net5501.
2757
3197059a
PP
2758config GEOS
2759 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2760 select GPIOLIB
2761 depends on DMI
2762 ---help---
2763 This option enables system support for the Traverse Technologies GEOS.
2764
7d029125
VD
2765config TS5500
2766 bool "Technologic Systems TS-5500 platform support"
2767 depends on MELAN
2768 select CHECK_SIGNATURE
2769 select NEW_LEDS
2770 select LEDS_CLASS
2771 ---help---
2772 This option enables system support for the Technologic Systems TS-5500.
2773
bc0120fd
SR
2774endif # X86_32
2775
23ac4ae8 2776config AMD_NB
e279b6c1 2777 def_bool y
0e152cd7 2778 depends on CPU_SUP_AMD && PCI
e279b6c1 2779
e3263ab3
DR
2780config X86_SYSFB
2781 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2782 help
2783 Firmwares often provide initial graphics framebuffers so the BIOS,
2784 bootloader or kernel can show basic video-output during boot for
2785 user-guidance and debugging. Historically, x86 used the VESA BIOS
2786 Extensions and EFI-framebuffers for this, which are mostly limited
2787 to x86.
2788 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2789 framebuffers so the new generic system-framebuffer drivers can be
2790 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2791 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DR
2792 drivers like efifb, vesafb and uvesafb can pick it up.
2793 If this option is not selected, all system framebuffers are always
2794 marked as fallback platform framebuffers as usual.
2795
2796 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2797 not be able to pick up generic system framebuffers if this option
2798 is selected. You are highly encouraged to enable simplefb as
2799 replacement if you select this option. simplefb can correctly deal
2800 with generic system framebuffers. But you should still keep vesafb
2801 and others enabled as fallback if a system framebuffer is
2802 incompatible with simplefb.
2803
2804 If unsure, say Y.
2805
e279b6c1
SR
2806endmenu
2807
2808
1572497c 2809menu "Binary Emulations"
e279b6c1
SR
2810
2811config IA32_EMULATION
2812 bool "IA32 Emulation"
2813 depends on X86_64
39f88911 2814 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2815 select BINFMT_ELF
a97f52e6 2816 select COMPAT_BINFMT_ELF
39f88911 2817 select COMPAT_OLD_SIGACTION
8f9ca475 2818 ---help---
5fd92e65
L
2819 Include code to run legacy 32-bit programs under a
2820 64-bit kernel. You should likely turn this on, unless you're
2821 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2822
2823config IA32_AOUT
8f9ca475
IM
2824 tristate "IA32 a.out support"
2825 depends on IA32_EMULATION
eac61655 2826 depends on BROKEN
8f9ca475
IM
2827 ---help---
2828 Support old a.out binaries in the 32bit emulation.
e279b6c1 2829
0bf62763 2830config X86_X32
6ea30386 2831 bool "x32 ABI for 64-bit mode"
9b54050b 2832 depends on X86_64
5fd92e65
L
2833 ---help---
2834 Include code to run binaries for the x32 native 32-bit ABI
2835 for 64-bit processors. An x32 process gets access to the
2836 full 64-bit register file and wide data path while leaving
2837 pointers at 32 bits for smaller memory footprint.
2838
2839 You will need a recent binutils (2.22 or later) with
2840 elf32_x86_64 support enabled to compile a kernel with this
2841 option set.
2842
953fee1d
IM
2843config COMPAT_32
2844 def_bool y
2845 depends on IA32_EMULATION || X86_32
2846 select HAVE_UID16
2847 select OLD_SIGSUSPEND3
2848
e279b6c1 2849config COMPAT
3c2362e6 2850 def_bool y
0bf62763 2851 depends on IA32_EMULATION || X86_X32
e279b6c1 2852
3120e25e 2853if COMPAT
e279b6c1 2854config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2855 def_bool y
e279b6c1
SR
2856
2857config SYSVIPC_COMPAT
3c2362e6 2858 def_bool y
3120e25e 2859 depends on SYSVIPC
3120e25e 2860endif
ee009e4a 2861
e279b6c1
SR
2862endmenu
2863
2864
e5beae16
KP
2865config HAVE_ATOMIC_IOMAP
2866 def_bool y
2867 depends on X86_32
2868
4692d77f
AR
2869config X86_DEV_DMA_OPS
2870 bool
f7219a53 2871
e585513b
KS
2872config HAVE_GENERIC_GUP
2873 def_bool y
2874
e279b6c1
SR
2875source "drivers/firmware/Kconfig"
2876
edf88417 2877source "arch/x86/kvm/Kconfig"