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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
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IM
17 select MODULES_USE_ELF_REL
18 select OLD_SIGACTION
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SR
19
20config X86_64
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JB
21 def_bool y
22 depends on 64BIT
d94e0685 23 # Options that are inherently 64-bit kernel only:
e1073d1e 24 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
d94e0685
IM
25 select ARCH_SUPPORTS_INT128
26 select ARCH_USE_CMPXCHG_LOCKREF
27 select HAVE_ARCH_SOFT_DIRTY
28 select MODULES_USE_ELF_RELA
f616ab59 29 select NEED_DMA_MAP_STATE
09230cbc 30 select SWIOTLB
d94e0685 31 select X86_DEV_DMA_OPS
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
47 select ANON_INODES
942fa985 48 select ARCH_32BIT_OFF_T if X86_32
6471b825 49 select ARCH_CLOCKSOURCE_DATA
2a21ad57 50 select ARCH_CLOCKSOURCE_INIT
6471b825 51 select ARCH_DISCARD_MEMBLOCK
c763ea26 52 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 53 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 54 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 55 select ARCH_HAS_ELF_RANDOMIZE
72d93104 56 select ARCH_HAS_FAST_MULTIPLIER
316d097c 57 select ARCH_HAS_FILTER_PGPROT
6974f0c4 58 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 59 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 60 select ARCH_HAS_KCOV if X86_64
10bcc80e 61 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 62 select ARCH_HAS_PMEM_API if X86_64
3010a5ea 63 select ARCH_HAS_PTE_SPECIAL
39208aa7 64 select ARCH_HAS_REFCOUNT
0aed55af 65 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
092b31aa 66 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
d2852a22 67 select ARCH_HAS_SET_MEMORY
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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
2c870e61 77 select ARCH_SUPPORTS_ACPI
6471b825 78 select ARCH_SUPPORTS_ATOMIC_RMW
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IM
79 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
80 select ARCH_USE_BUILTIN_BSWAP
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IM
81 select ARCH_USE_QUEUED_RWLOCKS
82 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 83 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 84 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
38d8b4e6 85 select ARCH_WANTS_THP_SWAP if X86_64
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IM
86 select BUILDTIME_EXTABLE_SORT
87 select CLKEVT_I8253
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IM
88 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
89 select CLOCKSOURCE_WATCHDOG
6471b825 90 select DCACHE_WORD_ACCESS
45471cd9
LT
91 select EDAC_ATOMIC_SCRUB
92 select EDAC_SUPPORT
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IM
93 select GENERIC_CLOCKEVENTS
94 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select GENERIC_CMOS_UPDATE
97 select GENERIC_CPU_AUTOPROBE
61dc0f55 98 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 99 select GENERIC_EARLY_IOREMAP
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IM
100 select GENERIC_FIND_FIRST_BIT
101 select GENERIC_IOMAP
c7d6c9dd 102 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 103 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 104 select GENERIC_IRQ_MIGRATION if SMP
6471b825 105 select GENERIC_IRQ_PROBE
c201c917 106 select GENERIC_IRQ_RESERVATION_MODE
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IM
107 select GENERIC_IRQ_SHOW
108 select GENERIC_PENDING_IRQ if SMP
109 select GENERIC_SMP_IDLE_THREAD
110 select GENERIC_STRNCPY_FROM_USER
111 select GENERIC_STRNLEN_USER
112 select GENERIC_TIME_VSYSCALL
7edaeb68 113 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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IM
114 select HAVE_ACPI_APEI if ACPI
115 select HAVE_ACPI_APEI_NMI if ACPI
116 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
117 select HAVE_ARCH_AUDITSYSCALL
118 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
119 select HAVE_ARCH_JUMP_LABEL
b34006c4 120 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 121 select HAVE_ARCH_KASAN if X86_64
6471b825 122 select HAVE_ARCH_KGDB
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DC
123 select HAVE_ARCH_MMAP_RND_BITS if MMU
124 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 125 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 126 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 127 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 128 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 129 select HAVE_ARCH_STACKLEAK
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IM
130 select HAVE_ARCH_TRACEHOOK
131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 133 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 134 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
135 select HAVE_CMPXCHG_DOUBLE
136 select HAVE_CMPXCHG_LOCAL
137 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 138 select HAVE_COPY_THREAD_TLS
cf4db259 139 select HAVE_C_RECORDMCOUNT
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IM
140 select HAVE_DEBUG_KMEMLEAK
141 select HAVE_DEBUG_STACKOVERFLOW
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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IM
151 select HAVE_FUNCTION_GRAPH_TRACER
152 select HAVE_FUNCTION_TRACER
6b90bd4b 153 select HAVE_GCC_PLUGINS
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IM
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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IM
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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IM
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
d86564a2 186 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE
6471b825 187 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 188 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 189 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 190 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 191 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 192 select HAVE_RSEQ
6471b825 193 select HAVE_SYSCALL_TRACEPOINTS
6471b825 194 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 195 select HAVE_USER_RETURN_NOTIFIER
05736e4a 196 select HOTPLUG_SMT if SMP
c0185808 197 select IRQ_FORCED_THREADING
86596f0a 198 select NEED_SG_DMA_LENGTH
2eac9c2d 199 select PCI_DOMAINS if PCI
625210cf 200 select PCI_LOCKLESS_CONFIG if PCI
6471b825 201 select PERF_EVENTS
3195ef59 202 select RTC_LIB
d6faca40 203 select RTC_MC146818_LIB
6471b825 204 select SPARSE_IRQ
83fe27ea 205 select SRCU
6471b825 206 select SYSCTL_EXCEPTION_TRACE
15f4eae7 207 select THREAD_INFO_IN_TASK
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IM
208 select USER_STACKTRACE_SUPPORT
209 select VIRT_TO_BUS
6471b825 210 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 211
ba7e4d13 212config INSTRUCTION_DECODER
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JB
213 def_bool y
214 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 215
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LT
216config OUTPUT_FORMAT
217 string
218 default "elf32-i386" if X86_32
219 default "elf64-x86-64" if X86_64
220
73531905 221config ARCH_DEFCONFIG
b9b39bfb 222 string
73531905
SR
223 default "arch/x86/configs/i386_defconfig" if X86_32
224 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 225
8d5fffb9 226config LOCKDEP_SUPPORT
3c2362e6 227 def_bool y
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SR
228
229config STACKTRACE_SUPPORT
3c2362e6 230 def_bool y
8d5fffb9 231
8d5fffb9 232config MMU
3c2362e6 233 def_bool y
8d5fffb9 234
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DC
235config ARCH_MMAP_RND_BITS_MIN
236 default 28 if 64BIT
237 default 8
238
239config ARCH_MMAP_RND_BITS_MAX
240 default 32 if 64BIT
241 default 16
242
243config ARCH_MMAP_RND_COMPAT_BITS_MIN
244 default 8
245
246config ARCH_MMAP_RND_COMPAT_BITS_MAX
247 default 16
248
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SR
249config SBUS
250 bool
251
252config GENERIC_ISA_DMA
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JB
253 def_bool y
254 depends on ISA_DMA_API
8d5fffb9 255
8d5fffb9 256config GENERIC_BUG
3c2362e6 257 def_bool y
8d5fffb9 258 depends on BUG
b93a531e
JB
259 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
260
261config GENERIC_BUG_RELATIVE_POINTERS
262 bool
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SR
263
264config GENERIC_HWEIGHT
3c2362e6 265 def_bool y
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SR
266
267config ARCH_MAY_HAVE_PC_FDC
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JB
268 def_bool y
269 depends on ISA_DMA_API
8d5fffb9 270
1032c0ba 271config RWSEM_XCHGADD_ALGORITHM
3120e25e 272 def_bool y
1032c0ba 273
1032c0ba
SR
274config GENERIC_CALIBRATE_DELAY
275 def_bool y
276
9a0b8415 277config ARCH_HAS_CPU_RELAX
278 def_bool y
279
1b27d05b
PE
280config ARCH_HAS_CACHE_LINE_SIZE
281 def_bool y
282
316d097c
DH
283config ARCH_HAS_FILTER_PGPROT
284 def_bool y
285
dd5af90a 286config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 287 def_bool y
b32ef636 288
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TH
289config NEED_PER_CPU_EMBED_FIRST_CHUNK
290 def_bool y
291
292config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
293 def_bool y
294
801e4062
JB
295config ARCH_HIBERNATION_POSSIBLE
296 def_bool y
801e4062 297
f4cb5700
JB
298config ARCH_SUSPEND_POSSIBLE
299 def_bool y
f4cb5700 300
cfe28c5d
SC
301config ARCH_WANT_HUGE_PMD_SHARE
302 def_bool y
303
53313b2c
SC
304config ARCH_WANT_GENERAL_HUGETLB
305 def_bool y
306
8d5fffb9 307config ZONE_DMA32
e0fd24a3 308 def_bool y if X86_64
8d5fffb9 309
8d5fffb9 310config AUDIT_ARCH
e0fd24a3 311 def_bool y if X86_64
8d5fffb9 312
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IM
313config ARCH_SUPPORTS_OPTIMIZED_INLINING
314 def_bool y
315
6a11f75b
AM
316config ARCH_SUPPORTS_DEBUG_PAGEALLOC
317 def_bool y
318
d6f2d75a
AR
319config KASAN_SHADOW_OFFSET
320 hex
321 depends on KASAN
322 default 0xdffffc0000000000
323
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SW
324config HAVE_INTEL_TXT
325 def_bool y
6ea30386 326 depends on INTEL_IOMMU && ACPI
69575d38 327
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SR
328config X86_32_SMP
329 def_bool y
330 depends on X86_32 && SMP
331
332config X86_64_SMP
333 def_bool y
334 depends on X86_64 && SMP
335
ccbeed3a
TH
336config X86_32_LAZY_GS
337 def_bool y
8458f8c2 338 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 339
2b144498
SD
340config ARCH_SUPPORTS_UPROBES
341 def_bool y
342
d20642f0
RH
343config FIX_EARLYCON_MEM
344 def_bool y
345
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KS
346config DYNAMIC_PHYSICAL_MASK
347 bool
348
98233368
KS
349config PGTABLE_LEVELS
350 int
77ef56e4 351 default 5 if X86_5LEVEL
98233368
KS
352 default 4 if X86_64
353 default 3 if X86_PAE
354 default 2
355
2a61f474
MY
356config CC_HAS_SANE_STACKPROTECTOR
357 bool
358 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
359 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
360 help
361 We have to make sure stack protector is unconditionally disabled if
362 the compiler produces broken code.
363
506f1d07
SR
364menu "Processor type and features"
365
5ee71535
RD
366config ZONE_DMA
367 bool "DMA memory allocation support" if EXPERT
368 default y
369 help
370 DMA memory allocation support allows devices with less than 32-bit
371 addressing to allocate within the first 16MB of address space.
372 Disable if no such devices will be used.
373
374 If unsure, say Y.
375
506f1d07
SR
376config SMP
377 bool "Symmetric multi-processing support"
378 ---help---
379 This enables support for systems with more than one CPU. If you have
4a474157
RG
380 a system with only one CPU, say N. If you have a system with more
381 than one CPU, say Y.
506f1d07 382
4a474157 383 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
384 machines, but will use only one CPU of a multiprocessor machine. If
385 you say Y here, the kernel will run on many, but not all,
4a474157 386 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
387 will run faster if you say N here.
388
389 Note that if you say Y here and choose architecture "586" or
390 "Pentium" under "Processor family", the kernel will not work on 486
391 architectures. Similarly, multiprocessor kernels for the "PPro"
392 architecture may not work on all Pentium based boards.
393
394 People using multiprocessor machines who say Y here should also say
395 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
396 Management" code will be disabled if you say Y here.
397
395cf969 398 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 399 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
506f1d07
SR
400 <http://www.tldp.org/docs.html#howto>.
401
402 If you don't know what to do here, say N.
403
9def39be
JT
404config X86_FEATURE_NAMES
405 bool "Processor feature human-readable names" if EMBEDDED
406 default y
407 ---help---
408 This option compiles in a table of x86 feature bits and corresponding
409 names. This is required to support /proc/cpuinfo and a few kernel
410 messages. You can disable this to save space, at the expense of
411 making those few kernel messages show numeric feature bits instead.
412
413 If in doubt, say Y.
414
06cd9a7d
YL
415config X86_X2APIC
416 bool "Support x2apic"
19e3d60d 417 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
418 ---help---
419 This enables x2apic support on CPUs that have this feature.
420
421 This allows 32-bit apic IDs (so it can support very large systems),
422 and accesses the local apic via MSRs not via mmio.
423
06cd9a7d
YL
424 If you don't know what to do here, say N.
425
6695c85b 426config X86_MPPARSE
6e87f9b7 427 bool "Enable MPS table" if ACPI || SFI
7a527688 428 default y
5ab74722 429 depends on X86_LOCAL_APIC
8f9ca475 430 ---help---
6695c85b
YL
431 For old smp systems that do not have proper acpi support. Newer systems
432 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 433
ddd70cf9
JN
434config GOLDFISH
435 def_bool y
436 depends on X86_GOLDFISH
437
76b04384
DW
438config RETPOLINE
439 bool "Avoid speculative indirect branches in kernel"
440 default y
d5028ba8 441 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
442 help
443 Compile kernel with the retpoline compiler options to guard against
444 kernel-to-user data leaks by avoiding speculative indirect
445 branches. Requires a compiler with -mindirect-branch=thunk-extern
446 support for full protection. The kernel may run slower.
447
e6d42931
JW
448config X86_CPU_RESCTRL
449 bool "x86 CPU resource control support"
6fe07ce3 450 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 451 select KERNFS
78e99b4a 452 help
e6d42931 453 Enable x86 CPU resource control support.
6fe07ce3
BM
454
455 Provide support for the allocation and monitoring of system resources
456 usage by the CPU.
457
458 Intel calls this Intel Resource Director Technology
459 (Intel(R) RDT). More information about RDT can be found in the
460 Intel x86 Architecture Software Developer Manual.
461
462 AMD calls this AMD Platform Quality of Service (AMD QoS).
463 More information about AMD QoS can be found in the AMD64 Technology
464 Platform Quality of Service Extensions manual.
78e99b4a
FY
465
466 Say N if unsure.
467
8425091f 468if X86_32
a0d0bb4d
RD
469config X86_BIGSMP
470 bool "Support for big SMP systems with more than 8 CPUs"
471 depends on SMP
472 ---help---
473 This option is needed for the systems that have more than 8 CPUs
474
c5c606d9
RT
475config X86_EXTENDED_PLATFORM
476 bool "Support for extended (non-PC) x86 platforms"
477 default y
8f9ca475 478 ---help---
06ac8346
IM
479 If you disable this option then the kernel will only support
480 standard PC platforms. (which covers the vast majority of
481 systems out there.)
482
8425091f
RT
483 If you enable this option then you'll be able to select support
484 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 485 Goldfish (Android emulator)
8425091f 486 AMD Elan
8425091f
RT
487 RDC R-321x SoC
488 SGI 320/540 (Visual Workstation)
83125a3a 489 STA2X11-based (e.g. Northville)
3f4110a4 490 Moorestown MID devices
06ac8346
IM
491
492 If you have one of these systems, or if you want to build a
493 generic distribution kernel, say Y here - otherwise say N.
8425091f 494endif
06ac8346 495
8425091f
RT
496if X86_64
497config X86_EXTENDED_PLATFORM
498 bool "Support for extended (non-PC) x86 platforms"
499 default y
500 ---help---
501 If you disable this option then the kernel will only support
502 standard PC platforms. (which covers the vast majority of
503 systems out there.)
504
505 If you enable this option then you'll be able to select support
506 for the following (non-PC) 64 bit x86 platforms:
44b111b5 507 Numascale NumaChip
8425091f
RT
508 ScaleMP vSMP
509 SGI Ultraviolet
510
511 If you have one of these systems, or if you want to build a
512 generic distribution kernel, say Y here - otherwise say N.
513endif
c5c606d9
RT
514# This is an alphabetically sorted list of 64 bit extended platforms
515# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
516config X86_NUMACHIP
517 bool "Numascale NumaChip"
518 depends on X86_64
519 depends on X86_EXTENDED_PLATFORM
520 depends on NUMA
521 depends on SMP
522 depends on X86_X2APIC
f9726bfd 523 depends on PCI_MMCONFIG
44b111b5
SP
524 ---help---
525 Adds support for Numascale NumaChip large-SMP systems. Needed to
526 enable more than ~168 cores.
527 If you don't have one of these, you should say N here.
506f1d07 528
c5c606d9
RT
529config X86_VSMP
530 bool "ScaleMP vSMP"
6276a074 531 select HYPERVISOR_GUEST
c5c606d9
RT
532 select PARAVIRT
533 depends on X86_64 && PCI
534 depends on X86_EXTENDED_PLATFORM
ead91d4b 535 depends on SMP
8f9ca475 536 ---help---
c5c606d9
RT
537 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
538 supposed to run on these EM64T-based machines. Only choose this option
539 if you have one of these machines.
5e3a77e9 540
03b48632
NP
541config X86_UV
542 bool "SGI Ultraviolet"
543 depends on X86_64
c5c606d9 544 depends on X86_EXTENDED_PLATFORM
54c28d29 545 depends on NUMA
1ecb4ae5 546 depends on EFI
9d6c26e7 547 depends on X86_X2APIC
1222e564 548 depends on PCI
8f9ca475 549 ---help---
03b48632
NP
550 This option is needed in order to support SGI Ultraviolet systems.
551 If you don't have one of these, you should say N here.
552
c5c606d9
RT
553# Following is an alphabetically sorted list of 32 bit extended platforms
554# Please maintain the alphabetic order if and when there are additions
506f1d07 555
ddd70cf9
JN
556config X86_GOLDFISH
557 bool "Goldfish (Virtual Platform)"
cb7b8023 558 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
559 ---help---
560 Enable support for the Goldfish virtual platform used primarily
561 for Android development. Unless you are building for the Android
562 Goldfish emulator say N here.
563
c751e17b
TG
564config X86_INTEL_CE
565 bool "CE4100 TV platform"
566 depends on PCI
567 depends on PCI_GODIRECT
6084a6e2 568 depends on X86_IO_APIC
c751e17b
TG
569 depends on X86_32
570 depends on X86_EXTENDED_PLATFORM
37bc9f50 571 select X86_REBOOTFIXUPS
da6b737b
SAS
572 select OF
573 select OF_EARLY_FLATTREE
c751e17b
TG
574 ---help---
575 Select for the Intel CE media processor (CE4100) SOC.
576 This option compiles in support for the CE4100 SOC for settop
577 boxes and media devices.
578
4cb9b00f 579config X86_INTEL_MID
43605ef1 580 bool "Intel MID platform support"
43605ef1 581 depends on X86_EXTENDED_PLATFORM
edc6bc78 582 depends on X86_PLATFORM_DEVICES
1ea7c673 583 depends on PCI
3fda5bb4 584 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 585 depends on X86_IO_APIC
7c9c3a1e 586 select SFI
4cb9b00f 587 select I2C
7c9c3a1e 588 select DW_APB_TIMER
1ea7c673 589 select APB_TIMER
1ea7c673 590 select INTEL_SCU_IPC
15a713df 591 select MFD_INTEL_MSIC
1ea7c673 592 ---help---
4cb9b00f
DC
593 Select to build a kernel capable of supporting Intel MID (Mobile
594 Internet Device) platform systems which do not have the PCI legacy
595 interfaces. If you are building for a PC class system say N here.
1ea7c673 596
4cb9b00f
DC
597 Intel MID platforms are based on an Intel processor and chipset which
598 consume less power than most of the x86 derivatives.
43605ef1 599
8bbc2a13
BD
600config X86_INTEL_QUARK
601 bool "Intel Quark platform support"
602 depends on X86_32
603 depends on X86_EXTENDED_PLATFORM
604 depends on X86_PLATFORM_DEVICES
605 depends on X86_TSC
606 depends on PCI
607 depends on PCI_GOANY
608 depends on X86_IO_APIC
609 select IOSF_MBI
610 select INTEL_IMR
9ab6eb51 611 select COMMON_CLK
8bbc2a13
BD
612 ---help---
613 Select to include support for Quark X1000 SoC.
614 Say Y here if you have a Quark based system such as the Arduino
615 compatible Intel Galileo.
616
3d48aab1
MW
617config X86_INTEL_LPSS
618 bool "Intel Low Power Subsystem Support"
5962dd22 619 depends on X86 && ACPI && PCI
3d48aab1 620 select COMMON_CLK
0f531431 621 select PINCTRL
eebb3e8d 622 select IOSF_MBI
3d48aab1
MW
623 ---help---
624 Select to build support for Intel Low Power Subsystem such as
625 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
626 things like clock tree (common clock framework) and pincontrol
627 which are needed by the LPSS peripheral drivers.
3d48aab1 628
92082a88
KX
629config X86_AMD_PLATFORM_DEVICE
630 bool "AMD ACPI2Platform devices support"
631 depends on ACPI
632 select COMMON_CLK
633 select PINCTRL
634 ---help---
635 Select to interpret AMD specific ACPI device to platform device
636 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
637 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
638 implemented under PINCTRL subsystem.
639
ced3ce76
DB
640config IOSF_MBI
641 tristate "Intel SoC IOSF Sideband support for SoC platforms"
642 depends on PCI
643 ---help---
644 This option enables sideband register access support for Intel SoC
645 platforms. On these platforms the IOSF sideband is used in lieu of
646 MSR's for some register accesses, mostly but not limited to thermal
647 and power. Drivers may query the availability of this device to
648 determine if they need the sideband in order to work on these
649 platforms. The sideband is available on the following SoC products.
650 This list is not meant to be exclusive.
651 - BayTrail
652 - Braswell
653 - Quark
654
655 You should say Y if you are running a kernel on one of these SoC's.
656
ed2226bd
DB
657config IOSF_MBI_DEBUG
658 bool "Enable IOSF sideband access through debugfs"
659 depends on IOSF_MBI && DEBUG_FS
660 ---help---
661 Select this option to expose the IOSF sideband access registers (MCR,
662 MDR, MCRX) through debugfs to write and read register information from
663 different units on the SoC. This is most useful for obtaining device
664 state information for debug and analysis. As this is a general access
665 mechanism, users of this option would have specific knowledge of the
666 device they want to access.
667
668 If you don't require the option or are in doubt, say N.
669
c5c606d9
RT
670config X86_RDC321X
671 bool "RDC R-321x SoC"
506f1d07 672 depends on X86_32
c5c606d9
RT
673 depends on X86_EXTENDED_PLATFORM
674 select M486
675 select X86_REBOOTFIXUPS
676 ---help---
677 This option is needed for RDC R-321x system-on-chip, also known
678 as R-8610-(G).
679 If you don't have one of these chips, you should say N here.
680
e0c7ae37 681config X86_32_NON_STANDARD
9c398017
IM
682 bool "Support non-standard 32-bit SMP architectures"
683 depends on X86_32 && SMP
c5c606d9 684 depends on X86_EXTENDED_PLATFORM
8f9ca475 685 ---help---
b5660ba7
PA
686 This option compiles in the bigsmp and STA2X11 default
687 subarchitectures. It is intended for a generic binary
688 kernel. If you select them all, kernel will probe it one by
689 one and will fallback to default.
d49c4288 690
c5c606d9 691# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 692
d949f36f 693config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 694 def_bool y
d949f36f
LT
695 # MCE code calls memory_failure():
696 depends on X86_MCE
697 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
698 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
699 depends on X86_64 || !SPARSEMEM
700 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 701
83125a3a
AR
702config STA2X11
703 bool "STA2X11 Companion Chip Support"
704 depends on X86_32_NON_STANDARD && PCI
b6e05477 705 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
706 select X86_DEV_DMA_OPS
707 select X86_DMA_REMAP
708 select SWIOTLB
709 select MFD_STA2X11
0145071b 710 select GPIOLIB
83125a3a
AR
711 ---help---
712 This adds support for boards based on the STA2X11 IO-Hub,
713 a.k.a. "ConneXt". The chip is used in place of the standard
714 PC chipset, so all "standard" peripherals are missing. If this
715 option is selected the kernel will still be able to boot on
716 standard PC machines.
717
82148d1d
S
718config X86_32_IRIS
719 tristate "Eurobraille/Iris poweroff module"
720 depends on X86_32
721 ---help---
722 The Iris machines from EuroBraille do not have APM or ACPI support
723 to shut themselves down properly. A special I/O sequence is
724 needed to do so, which is what this module does at
725 kernel shutdown.
726
727 This is only for Iris machines from EuroBraille.
728
729 If unused, say N.
730
ae1e9130 731config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
732 def_bool y
733 prompt "Single-depth WCHAN output"
a87d0914 734 depends on X86
8f9ca475 735 ---help---
506f1d07
SR
736 Calculate simpler /proc/<PID>/wchan values. If this option
737 is disabled then wchan values will recurse back to the
738 caller function. This provides more accurate wchan values,
739 at the expense of slightly more scheduling overhead.
740
741 If in doubt, say "Y".
742
6276a074
BP
743menuconfig HYPERVISOR_GUEST
744 bool "Linux guest support"
8f9ca475 745 ---help---
6276a074
BP
746 Say Y here to enable options for running Linux under various hyper-
747 visors. This option enables basic hypervisor detection and platform
748 setup.
506f1d07 749
6276a074
BP
750 If you say N, all options in this submenu will be skipped and
751 disabled, and Linux guest support won't be built in.
506f1d07 752
6276a074 753if HYPERVISOR_GUEST
506f1d07 754
e61bd94a
EPH
755config PARAVIRT
756 bool "Enable paravirtualization code"
8f9ca475 757 ---help---
e61bd94a
EPH
758 This changes the kernel so it can modify itself when it is run
759 under a hypervisor, potentially improving performance significantly
760 over full virtualization. However, when run without a hypervisor
761 the kernel is theoretically slower and slightly larger.
762
c00a280a
JG
763config PARAVIRT_XXL
764 bool
765
6276a074
BP
766config PARAVIRT_DEBUG
767 bool "paravirt-ops debugging"
768 depends on PARAVIRT && DEBUG_KERNEL
769 ---help---
770 Enable to debug paravirt_ops internals. Specifically, BUG if
771 a paravirt_op is missing when it is called.
772
b4ecc126
JF
773config PARAVIRT_SPINLOCKS
774 bool "Paravirtualization layer for spinlocks"
6ea30386 775 depends on PARAVIRT && SMP
b4ecc126
JF
776 ---help---
777 Paravirtualized spinlocks allow a pvops backend to replace the
778 spinlock implementation with something virtualization-friendly
779 (for example, block the virtual CPU rather than spinning).
780
4c4e4f61
R
781 It has a minimal impact on native kernels and gives a nice performance
782 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 783
4c4e4f61 784 If you are unsure how to answer this question, answer Y.
b4ecc126 785
45e898b7
WL
786config QUEUED_LOCK_STAT
787 bool "Paravirt queued spinlock statistics"
cfd8983f 788 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
789 ---help---
790 Enable the collection of statistical data on the slowpath
791 behavior of paravirtualized queued spinlocks and report
792 them on debugfs.
793
6276a074 794source "arch/x86/xen/Kconfig"
7af192c9 795
6276a074
BP
796config KVM_GUEST
797 bool "KVM Guest support (including kvmclock)"
798 depends on PARAVIRT
799 select PARAVIRT_CLOCK
800 default y
8f9ca475 801 ---help---
6276a074
BP
802 This option enables various optimizations for running under the KVM
803 hypervisor. It includes a paravirtualized clock, so that instead
804 of relying on a PIT (or probably other) emulation by the
805 underlying device model, the host provides the guest with
806 timing infrastructure such as time of day, and system time
506f1d07 807
7733607f
MW
808config PVH
809 bool "Support for running PVH guests"
810 ---help---
811 This option enables the PVH entry point for guest virtual machines
812 as specified in the x86/HVM direct boot ABI.
813
1e20eb85
SV
814config KVM_DEBUG_FS
815 bool "Enable debug information for KVM Guests in debugfs"
816 depends on KVM_GUEST && DEBUG_FS
1e20eb85
SV
817 ---help---
818 This option enables collection of various statistics for KVM guest.
819 Statistics are displayed in debugfs filesystem. Enabling this option
820 may incur significant overhead.
821
6276a074
BP
822config PARAVIRT_TIME_ACCOUNTING
823 bool "Paravirtual steal time accounting"
824 depends on PARAVIRT
8f9ca475 825 ---help---
6276a074
BP
826 Select this option to enable fine granularity task steal time
827 accounting. Time spent executing other tasks in parallel with
828 the current vCPU is discounted from the vCPU power. To account for
829 that, there can be a small performance impact.
830
831 If in doubt, say N here.
832
833config PARAVIRT_CLOCK
834 bool
97349135 835
4a362601
JK
836config JAILHOUSE_GUEST
837 bool "Jailhouse non-root cell support"
abde587b 838 depends on X86_64 && PCI
87e65d05 839 select X86_PM_TIMER
4a362601
JK
840 ---help---
841 This option allows to run Linux as guest in a Jailhouse non-root
842 cell. You can leave this option disabled if you only want to start
843 Jailhouse and run Linux afterwards in the root cell.
844
6276a074 845endif #HYPERVISOR_GUEST
97349135 846
506f1d07
SR
847source "arch/x86/Kconfig.cpu"
848
849config HPET_TIMER
3c2362e6 850 def_bool X86_64
506f1d07 851 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
852 ---help---
853 Use the IA-PC HPET (High Precision Event Timer) to manage
854 time in preference to the PIT and RTC, if a HPET is
855 present.
856 HPET is the next generation timer replacing legacy 8254s.
857 The HPET provides a stable time base on SMP
858 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
859 as it is off-chip. The interface used is documented
860 in the HPET spec, revision 1.
506f1d07 861
8f9ca475
IM
862 You can safely choose Y here. However, HPET will only be
863 activated if the platform and the BIOS support this feature.
864 Otherwise the 8254 will be used for timing services.
506f1d07 865
8f9ca475 866 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
867
868config HPET_EMULATE_RTC
3c2362e6 869 def_bool y
9d8af78b 870 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 871
bb24c471 872config APB_TIMER
933b9463
AC
873 def_bool y if X86_INTEL_MID
874 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 875 select DW_APB_TIMER
a0c3832a 876 depends on X86_INTEL_MID && SFI
bb24c471
JP
877 help
878 APB timer is the replacement for 8254, HPET on X86 MID platforms.
879 The APBT provides a stable time base on SMP
880 systems, unlike the TSC, but it is more expensive to access,
881 as it is off-chip. APB timers are always running regardless of CPU
882 C states, they are used as per CPU clockevent device when possible.
883
6a108a14 884# Mark as expert because too many people got it wrong.
506f1d07 885# The code disables itself when not needed.
7ae9392c
TP
886config DMI
887 default y
cf074402 888 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 889 bool "Enable DMI scanning" if EXPERT
8f9ca475 890 ---help---
7ae9392c
TP
891 Enabled scanning of DMI to identify machine quirks. Say Y
892 here unless you have verified that your setup is not
893 affected by entries in the DMI blacklist. Required by PNP
894 BIOS code.
895
506f1d07 896config GART_IOMMU
38901f1c 897 bool "Old AMD GART IOMMU support"
a4ce5a48 898 select IOMMU_HELPER
506f1d07 899 select SWIOTLB
23ac4ae8 900 depends on X86_64 && PCI && AMD_NB
8f9ca475 901 ---help---
ced3c42c
IM
902 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
903 GART based hardware IOMMUs.
904
905 The GART supports full DMA access for devices with 32-bit access
906 limitations, on systems with more than 3 GB. This is usually needed
907 for USB, sound, many IDE/SATA chipsets and some other devices.
908
909 Newer systems typically have a modern AMD IOMMU, supported via
910 the CONFIG_AMD_IOMMU=y config option.
911
912 In normal configurations this driver is only active when needed:
913 there's more than 3 GB of memory and the system contains a
914 32-bit limited device.
915
916 If unsure, say Y.
506f1d07
SR
917
918config CALGARY_IOMMU
919 bool "IBM Calgary IOMMU support"
a4ce5a48 920 select IOMMU_HELPER
506f1d07 921 select SWIOTLB
6ea30386 922 depends on X86_64 && PCI
8f9ca475 923 ---help---
506f1d07
SR
924 Support for hardware IOMMUs in IBM's xSeries x366 and x460
925 systems. Needed to run systems with more than 3GB of memory
926 properly with 32-bit PCI devices that do not support DAC
927 (Double Address Cycle). Calgary also supports bus level
928 isolation, where all DMAs pass through the IOMMU. This
929 prevents them from going anywhere except their intended
930 destination. This catches hard-to-find kernel bugs and
931 mis-behaving drivers and devices that do not use the DMA-API
932 properly to set up their DMA buffers. The IOMMU can be
933 turned off at boot time with the iommu=off parameter.
934 Normally the kernel will make the right choice by itself.
935 If unsure, say Y.
936
937config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
938 def_bool y
939 prompt "Should Calgary be enabled by default?"
506f1d07 940 depends on CALGARY_IOMMU
8f9ca475 941 ---help---
506f1d07
SR
942 Should Calgary be enabled by default? if you choose 'y', Calgary
943 will be used (if it exists). If you choose 'n', Calgary will not be
944 used even if it exists. If you choose 'n' and would like to use
945 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
946 If unsure, say Y.
506f1d07 947
1184dc2f 948config MAXSMP
ddb0c5a6 949 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 950 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 951 select CPUMASK_OFFSTACK
8f9ca475 952 ---help---
ddb0c5a6 953 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 954 If unsure, say N.
506f1d07 955
aec6487e
IM
956#
957# The maximum number of CPUs supported:
958#
959# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
960# and which can be configured interactively in the
961# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
962#
963# The ranges are different on 32-bit and 64-bit kernels, depending on
964# hardware capabilities and scalability features of the kernel.
965#
966# ( If MAXSMP is enabled we just use the highest possible value and disable
967# interactive configuration. )
968#
969
970config NR_CPUS_RANGE_BEGIN
a0d0bb4d 971 int
aec6487e
IM
972 default NR_CPUS_RANGE_END if MAXSMP
973 default 1 if !SMP
974 default 2
a0d0bb4d 975
aec6487e 976config NR_CPUS_RANGE_END
a0d0bb4d 977 int
aec6487e
IM
978 depends on X86_32
979 default 64 if SMP && X86_BIGSMP
980 default 8 if SMP && !X86_BIGSMP
981 default 1 if !SMP
a0d0bb4d 982
aec6487e 983config NR_CPUS_RANGE_END
a0d0bb4d 984 int
aec6487e
IM
985 depends on X86_64
986 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
987 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
988 default 1 if !SMP
a0d0bb4d 989
aec6487e 990config NR_CPUS_DEFAULT
a0d0bb4d
RD
991 int
992 depends on X86_32
aec6487e
IM
993 default 32 if X86_BIGSMP
994 default 8 if SMP
995 default 1 if !SMP
a0d0bb4d 996
aec6487e 997config NR_CPUS_DEFAULT
a0d0bb4d
RD
998 int
999 depends on X86_64
aec6487e
IM
1000 default 8192 if MAXSMP
1001 default 64 if SMP
1002 default 1 if !SMP
a0d0bb4d 1003
506f1d07 1004config NR_CPUS
36f5101a 1005 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
1006 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1007 default NR_CPUS_DEFAULT
8f9ca475 1008 ---help---
506f1d07 1009 This allows you to specify the maximum number of CPUs which this
bb61ccc7 1010 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 1011 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
1012 minimum value which makes sense is 2.
1013
aec6487e
IM
1014 This is purely to save memory: each supported CPU adds about 8KB
1015 to the kernel image.
506f1d07
SR
1016
1017config SCHED_SMT
dbe73364 1018 def_bool y if SMP
506f1d07
SR
1019
1020config SCHED_MC
3c2362e6
HH
1021 def_bool y
1022 prompt "Multi-core scheduler support"
c8e56d20 1023 depends on SMP
8f9ca475 1024 ---help---
506f1d07
SR
1025 Multi-core scheduler support improves the CPU scheduler's decision
1026 making when dealing with multi-core CPU chips at a cost of slightly
1027 increased overhead in some places. If unsure say N here.
1028
de966cf4
TC
1029config SCHED_MC_PRIO
1030 bool "CPU core priorities scheduler support"
0a21fc12
IM
1031 depends on SCHED_MC && CPU_SUP_INTEL
1032 select X86_INTEL_PSTATE
1033 select CPU_FREQ
de966cf4 1034 default y
5e76b2ab 1035 ---help---
0a21fc12
IM
1036 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1037 core ordering determined at manufacturing time, which allows
1038 certain cores to reach higher turbo frequencies (when running
1039 single threaded workloads) than others.
de966cf4 1040
0a21fc12
IM
1041 Enabling this kernel feature teaches the scheduler about
1042 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1043 scheduler's CPU selection logic accordingly, so that higher
1044 overall system performance can be achieved.
de966cf4 1045
0a21fc12 1046 This feature will have no effect on CPUs without this feature.
de966cf4 1047
0a21fc12 1048 If unsure say Y here.
5e76b2ab 1049
30b8b006
TG
1050config UP_LATE_INIT
1051 def_bool y
ba360f88 1052 depends on !SMP && X86_LOCAL_APIC
30b8b006 1053
506f1d07 1054config X86_UP_APIC
50849eef
JB
1055 bool "Local APIC support on uniprocessors" if !PCI_MSI
1056 default PCI_MSI
38a1dfda 1057 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1058 ---help---
506f1d07
SR
1059 A local APIC (Advanced Programmable Interrupt Controller) is an
1060 integrated interrupt controller in the CPU. If you have a single-CPU
1061 system which has a processor with a local APIC, you can say Y here to
1062 enable and use it. If you say Y here even though your machine doesn't
1063 have a local APIC, then the kernel will still run with no slowdown at
1064 all. The local APIC supports CPU-generated self-interrupts (timer,
1065 performance counters), and the NMI watchdog which detects hard
1066 lockups.
1067
1068config X86_UP_IOAPIC
1069 bool "IO-APIC support on uniprocessors"
1070 depends on X86_UP_APIC
8f9ca475 1071 ---help---
506f1d07
SR
1072 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1073 SMP-capable replacement for PC-style interrupt controllers. Most
1074 SMP systems and many recent uniprocessor systems have one.
1075
1076 If you have a single-CPU system with an IO-APIC, you can say Y here
1077 to use it. If you say Y here even though your machine doesn't have
1078 an IO-APIC, then the kernel will still run with no slowdown at all.
1079
1080config X86_LOCAL_APIC
3c2362e6 1081 def_bool y
0dbc6078 1082 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1083 select IRQ_DOMAIN_HIERARCHY
52f518a3 1084 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1085
1086config X86_IO_APIC
b1da1e71
JB
1087 def_bool y
1088 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1089
41b9eb26
SA
1090config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1091 bool "Reroute for broken boot IRQs"
41b9eb26 1092 depends on X86_IO_APIC
8f9ca475 1093 ---help---
41b9eb26
SA
1094 This option enables a workaround that fixes a source of
1095 spurious interrupts. This is recommended when threaded
1096 interrupt handling is used on systems where the generation of
1097 superfluous "boot interrupts" cannot be disabled.
1098
1099 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1100 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1101 kernel does during interrupt handling). On chipsets where this
1102 boot IRQ generation cannot be disabled, this workaround keeps
1103 the original IRQ line masked so that only the equivalent "boot
1104 IRQ" is delivered to the CPUs. The workaround also tells the
1105 kernel to set up the IRQ handler on the boot IRQ line. In this
1106 way only one interrupt is delivered to the kernel. Otherwise
1107 the spurious second interrupt may cause the kernel to bring
1108 down (vital) interrupt lines.
1109
1110 Only affects "broken" chipsets. Interrupt sharing may be
1111 increased on these systems.
1112
506f1d07 1113config X86_MCE
bab9bc65 1114 bool "Machine Check / overheating reporting"
648ed940 1115 select GENERIC_ALLOCATOR
e57dbaf7 1116 default y
506f1d07 1117 ---help---
bab9bc65
AK
1118 Machine Check support allows the processor to notify the
1119 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1120 The action the kernel takes depends on the severity of the problem,
bab9bc65 1121 ranging from warning messages to halting the machine.
4efc0670 1122
5de97c9f
TL
1123config X86_MCELOG_LEGACY
1124 bool "Support for deprecated /dev/mcelog character device"
1125 depends on X86_MCE
1126 ---help---
1127 Enable support for /dev/mcelog which is needed by the old mcelog
1128 userspace logging daemon. Consider switching to the new generation
1129 rasdaemon solution.
1130
506f1d07 1131config X86_MCE_INTEL
3c2362e6
HH
1132 def_bool y
1133 prompt "Intel MCE features"
c1ebf835 1134 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1135 ---help---
506f1d07
SR
1136 Additional support for intel specific MCE features such as
1137 the thermal monitor.
1138
1139config X86_MCE_AMD
3c2362e6
HH
1140 def_bool y
1141 prompt "AMD MCE features"
f5382de9 1142 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1143 ---help---
506f1d07
SR
1144 Additional support for AMD specific MCE features such as
1145 the DRAM Error Threshold.
1146
4efc0670 1147config X86_ANCIENT_MCE
6fc108a0 1148 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1149 depends on X86_32 && X86_MCE
cd13adcc
HS
1150 ---help---
1151 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1152 systems. These typically need to be enabled explicitly on the command
cd13adcc 1153 line.
4efc0670 1154
b2762686
AK
1155config X86_MCE_THRESHOLD
1156 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1157 def_bool y
b2762686 1158
ea149b36 1159config X86_MCE_INJECT
bc8e80d5 1160 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1161 tristate "Machine check injector support"
1162 ---help---
1163 Provide support for injecting machine checks for testing purposes.
1164 If you don't know what a machine check is and you don't do kernel
1165 QA it is safe to say n.
1166
4efc0670
AK
1167config X86_THERMAL_VECTOR
1168 def_bool y
5bb38adc 1169 depends on X86_MCE_INTEL
4efc0670 1170
07dc900e 1171source "arch/x86/events/Kconfig"
e633c65a 1172
5aef51c3 1173config X86_LEGACY_VM86
1e642812 1174 bool "Legacy VM86 support"
506f1d07 1175 depends on X86_32
8f9ca475 1176 ---help---
5aef51c3
AL
1177 This option allows user programs to put the CPU into V8086
1178 mode, which is an 80286-era approximation of 16-bit real mode.
1179
1180 Some very old versions of X and/or vbetool require this option
1181 for user mode setting. Similarly, DOSEMU will use it if
1182 available to accelerate real mode DOS programs. However, any
1183 recent version of DOSEMU, X, or vbetool should be fully
1184 functional even without kernel VM86 support, as they will all
1e642812
IM
1185 fall back to software emulation. Nevertheless, if you are using
1186 a 16-bit DOS program where 16-bit performance matters, vm86
1187 mode might be faster than emulation and you might want to
1188 enable this option.
5aef51c3 1189
1e642812
IM
1190 Note that any app that works on a 64-bit kernel is unlikely to
1191 need this option, as 64-bit kernels don't, and can't, support
1192 V8086 mode. This option is also unrelated to 16-bit protected
1193 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1194
1e642812
IM
1195 Enabling this option increases the complexity of the kernel
1196 and slows down exception handling a tiny bit.
5aef51c3 1197
1e642812 1198 If unsure, say N here.
5aef51c3
AL
1199
1200config VM86
1201 bool
1202 default X86_LEGACY_VM86
34273f41
PA
1203
1204config X86_16BIT
1205 bool "Enable support for 16-bit segments" if EXPERT
1206 default y
a5b9e5a2 1207 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1208 ---help---
1209 This option is required by programs like Wine to run 16-bit
1210 protected mode legacy code on x86 processors. Disabling
1211 this option saves about 300 bytes on i386, or around 6K text
1212 plus 16K runtime memory on x86-64,
1213
1214config X86_ESPFIX32
1215 def_bool y
1216 depends on X86_16BIT && X86_32
506f1d07 1217
197725de
PA
1218config X86_ESPFIX64
1219 def_bool y
34273f41 1220 depends on X86_16BIT && X86_64
506f1d07 1221
1ad83c85
AL
1222config X86_VSYSCALL_EMULATION
1223 bool "Enable vsyscall emulation" if EXPERT
1224 default y
1225 depends on X86_64
1226 ---help---
1227 This enables emulation of the legacy vsyscall page. Disabling
1228 it is roughly equivalent to booting with vsyscall=none, except
1229 that it will also disable the helpful warning if a program
1230 tries to use a vsyscall. With this option set to N, offending
1231 programs will just segfault, citing addresses of the form
1232 0xffffffffff600?00.
1233
1234 This option is required by many programs built before 2013, and
1235 care should be used even with newer programs if set to N.
1236
1237 Disabling this option saves about 7K of kernel size and
1238 possibly 4K of additional runtime pagetable memory.
1239
506f1d07
SR
1240config TOSHIBA
1241 tristate "Toshiba Laptop support"
1242 depends on X86_32
1243 ---help---
1244 This adds a driver to safely access the System Management Mode of
1245 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1246 not work on models with a Phoenix BIOS. The System Management Mode
1247 is used to set the BIOS and power saving options on Toshiba portables.
1248
1249 For information on utilities to make use of this driver see the
1250 Toshiba Linux utilities web site at:
1251 <http://www.buzzard.org.uk/toshiba/>.
1252
1253 Say Y if you intend to run this kernel on a Toshiba portable.
1254 Say N otherwise.
1255
1256config I8K
039ae585 1257 tristate "Dell i8k legacy laptop support"
949a9d70 1258 select HWMON
039ae585 1259 select SENSORS_DELL_SMM
506f1d07 1260 ---help---
039ae585
PR
1261 This option enables legacy /proc/i8k userspace interface in hwmon
1262 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1263 temperature and allows controlling fan speeds of Dell laptops via
1264 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1265 it reports also power and hotkey status. For fan speed control is
1266 needed userspace package i8kutils.
1267
1268 Say Y if you intend to run this kernel on old Dell laptops or want to
1269 use userspace package i8kutils.
506f1d07
SR
1270 Say N otherwise.
1271
1272config X86_REBOOTFIXUPS
9ba16087
JB
1273 bool "Enable X86 board specific fixups for reboot"
1274 depends on X86_32
506f1d07
SR
1275 ---help---
1276 This enables chipset and/or board specific fixups to be done
1277 in order to get reboot to work correctly. This is only needed on
1278 some combinations of hardware and BIOS. The symptom, for which
1279 this config is intended, is when reboot ends with a stalled/hung
1280 system.
1281
1282 Currently, the only fixup is for the Geode machines using
5e3a77e9 1283 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1284
1285 Say Y if you want to enable the fixup. Currently, it's safe to
1286 enable this option even if you don't need it.
1287 Say N otherwise.
1288
1289config MICROCODE
9a2bc335
BP
1290 bool "CPU microcode loading support"
1291 default y
80030e3d 1292 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1293 select FW_LOADER
1294 ---help---
1295 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1296 Intel and AMD processors. The Intel support is for the IA32 family,
1297 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1298 AMD support is for families 0x10 and later. You will obviously need
1299 the actual microcode binary data itself which is not shipped with
1300 the Linux kernel.
1301
1302 The preferred method to load microcode from a detached initrd is described
1897a969 1303 in Documentation/x86/microcode.txt. For that you need to enable
5f9c01aa
BP
1304 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1305 initrd for microcode blobs.
1306
c508c46e
BG
1307 In addition, you can build the microcode into the kernel. For that you
1308 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1309 config option.
506f1d07 1310
8d86f390 1311config MICROCODE_INTEL
e43f6e67 1312 bool "Intel microcode loading support"
8f9ca475
IM
1313 depends on MICROCODE
1314 default MICROCODE
1315 select FW_LOADER
1316 ---help---
1317 This options enables microcode patch loading support for Intel
1318 processors.
1319
b8989db9
A
1320 For the current Intel microcode data package go to
1321 <https://downloadcenter.intel.com> and search for
1322 'Linux Processor Microcode Data File'.
8d86f390 1323
80cc9f10 1324config MICROCODE_AMD
e43f6e67 1325 bool "AMD microcode loading support"
8f9ca475
IM
1326 depends on MICROCODE
1327 select FW_LOADER
1328 ---help---
1329 If you select this option, microcode patch loading support for AMD
1330 processors will be enabled.
80cc9f10 1331
8f9ca475 1332config MICROCODE_OLD_INTERFACE
3c2362e6 1333 def_bool y
506f1d07 1334 depends on MICROCODE
506f1d07
SR
1335
1336config X86_MSR
1337 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1338 ---help---
506f1d07
SR
1339 This device gives privileged processes access to the x86
1340 Model-Specific Registers (MSRs). It is a character device with
1341 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1342 MSR accesses are directed to a specific CPU on multi-processor
1343 systems.
1344
1345config X86_CPUID
1346 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1347 ---help---
506f1d07
SR
1348 This device gives processes access to the x86 CPUID instruction to
1349 be executed on a specific processor. It is a character device
1350 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1351 /dev/cpu/31/cpuid.
1352
1353choice
1354 prompt "High Memory Support"
6fc108a0 1355 default HIGHMEM4G
506f1d07
SR
1356 depends on X86_32
1357
1358config NOHIGHMEM
1359 bool "off"
506f1d07
SR
1360 ---help---
1361 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1362 However, the address space of 32-bit x86 processors is only 4
1363 Gigabytes large. That means that, if you have a large amount of
1364 physical memory, not all of it can be "permanently mapped" by the
1365 kernel. The physical memory that's not permanently mapped is called
1366 "high memory".
1367
1368 If you are compiling a kernel which will never run on a machine with
1369 more than 1 Gigabyte total physical RAM, answer "off" here (default
1370 choice and suitable for most users). This will result in a "3GB/1GB"
1371 split: 3GB are mapped so that each process sees a 3GB virtual memory
1372 space and the remaining part of the 4GB virtual memory space is used
1373 by the kernel to permanently map as much physical memory as
1374 possible.
1375
1376 If the machine has between 1 and 4 Gigabytes physical RAM, then
1377 answer "4GB" here.
1378
1379 If more than 4 Gigabytes is used then answer "64GB" here. This
1380 selection turns Intel PAE (Physical Address Extension) mode on.
1381 PAE implements 3-level paging on IA32 processors. PAE is fully
1382 supported by Linux, PAE mode is implemented on all recent Intel
1383 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1384 then the kernel will not boot on CPUs that don't support PAE!
1385
1386 The actual amount of total physical memory will either be
1387 auto detected or can be forced by using a kernel command line option
1388 such as "mem=256M". (Try "man bootparam" or see the documentation of
1389 your boot loader (lilo or loadlin) about how to pass options to the
1390 kernel at boot time.)
1391
1392 If unsure, say "off".
1393
1394config HIGHMEM4G
1395 bool "4GB"
8f9ca475 1396 ---help---
506f1d07
SR
1397 Select this if you have a 32-bit processor and between 1 and 4
1398 gigabytes of physical RAM.
1399
1400config HIGHMEM64G
1401 bool "64GB"
69b8d3fc 1402 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1403 select X86_PAE
8f9ca475 1404 ---help---
506f1d07
SR
1405 Select this if you have a 32-bit processor and more than 4
1406 gigabytes of physical RAM.
1407
1408endchoice
1409
1410choice
6a108a14 1411 prompt "Memory split" if EXPERT
506f1d07
SR
1412 default VMSPLIT_3G
1413 depends on X86_32
8f9ca475 1414 ---help---
506f1d07
SR
1415 Select the desired split between kernel and user memory.
1416
1417 If the address range available to the kernel is less than the
1418 physical memory installed, the remaining memory will be available
1419 as "high memory". Accessing high memory is a little more costly
1420 than low memory, as it needs to be mapped into the kernel first.
1421 Note that increasing the kernel address space limits the range
1422 available to user programs, making the address space there
1423 tighter. Selecting anything other than the default 3G/1G split
1424 will also likely make your kernel incompatible with binary-only
1425 kernel modules.
1426
1427 If you are not absolutely sure what you are doing, leave this
1428 option alone!
1429
1430 config VMSPLIT_3G
1431 bool "3G/1G user/kernel split"
1432 config VMSPLIT_3G_OPT
1433 depends on !X86_PAE
1434 bool "3G/1G user/kernel split (for full 1G low memory)"
1435 config VMSPLIT_2G
1436 bool "2G/2G user/kernel split"
1437 config VMSPLIT_2G_OPT
1438 depends on !X86_PAE
1439 bool "2G/2G user/kernel split (for full 2G low memory)"
1440 config VMSPLIT_1G
1441 bool "1G/3G user/kernel split"
1442endchoice
1443
1444config PAGE_OFFSET
1445 hex
1446 default 0xB0000000 if VMSPLIT_3G_OPT
1447 default 0x80000000 if VMSPLIT_2G
1448 default 0x78000000 if VMSPLIT_2G_OPT
1449 default 0x40000000 if VMSPLIT_1G
1450 default 0xC0000000
1451 depends on X86_32
1452
1453config HIGHMEM
3c2362e6 1454 def_bool y
506f1d07 1455 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1456
1457config X86_PAE
9ba16087 1458 bool "PAE (Physical Address Extension) Support"
506f1d07 1459 depends on X86_32 && !HIGHMEM4G
d4a451d5 1460 select PHYS_ADDR_T_64BIT
9d99c712 1461 select SWIOTLB
8f9ca475 1462 ---help---
506f1d07
SR
1463 PAE is required for NX support, and furthermore enables
1464 larger swapspace support for non-overcommit purposes. It
1465 has the cost of more pagetable lookup overhead, and also
1466 consumes more pagetable space per process.
1467
77ef56e4
KS
1468config X86_5LEVEL
1469 bool "Enable 5-level page tables support"
eedb92ab 1470 select DYNAMIC_MEMORY_LAYOUT
162434e7 1471 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1472 depends on X86_64
1473 ---help---
1474 5-level paging enables access to larger address space:
1475 upto 128 PiB of virtual address space and 4 PiB of
1476 physical address space.
1477
1478 It will be supported by future Intel CPUs.
1479
6657fca0
KS
1480 A kernel with the option enabled can be booted on machines that
1481 support 4- or 5-level paging.
77ef56e4
KS
1482
1483 See Documentation/x86/x86_64/5level-paging.txt for more
1484 information.
1485
1486 Say N if unsure.
1487
10971ab2 1488config X86_DIRECT_GBPAGES
e5008abe 1489 def_bool y
4675ff05 1490 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1491 ---help---
10971ab2
IM
1492 Certain kernel features effectively disable kernel
1493 linear 1 GB mappings (even if the CPU otherwise
1494 supports them), so don't confuse the user by printing
1495 that we have them enabled.
9e899816 1496
5c280cf6
TG
1497config X86_CPA_STATISTICS
1498 bool "Enable statistic for Change Page Attribute"
1499 depends on DEBUG_FS
1500 ---help---
1501 Expose statistics about the Change Page Attribute mechanims, which
1502 helps to determine the effectivness of preserving large and huge
1503 page mappings when mapping protections are changed.
1504
7744ccdb
TL
1505config ARCH_HAS_MEM_ENCRYPT
1506 def_bool y
1507
1508config AMD_MEM_ENCRYPT
1509 bool "AMD Secure Memory Encryption (SME) support"
1510 depends on X86_64 && CPU_SUP_AMD
94d49eb3 1511 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1512 select ARCH_USE_MEMREMAP_PROT
7744ccdb
TL
1513 ---help---
1514 Say yes to enable support for the encryption of system memory.
1515 This requires an AMD processor that supports Secure Memory
1516 Encryption (SME).
1517
1518config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1519 bool "Activate AMD Secure Memory Encryption (SME) by default"
1520 default y
1521 depends on AMD_MEM_ENCRYPT
1522 ---help---
1523 Say yes to have system memory encrypted by default if running on
1524 an AMD processor that supports Secure Memory Encryption (SME).
1525
1526 If set to Y, then the encryption of system memory can be
1527 deactivated with the mem_encrypt=off command line option.
1528
1529 If set to N, then the encryption of system memory can be
1530 activated with the mem_encrypt=on command line option.
1531
506f1d07
SR
1532# Common NUMA Features
1533config NUMA
fd51b2d7 1534 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1535 depends on SMP
b5660ba7
PA
1536 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1537 default y if X86_BIGSMP
8f9ca475 1538 ---help---
506f1d07 1539 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1540
506f1d07
SR
1541 The kernel will try to allocate memory used by a CPU on the
1542 local memory controller of the CPU and add some more
1543 NUMA awareness to the kernel.
1544
c280ea5e 1545 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1546 (or later), AMD Opteron, or EM64T NUMA.
1547
b5660ba7 1548 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1549 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1550
1551 Otherwise, you should say N.
506f1d07 1552
eec1d4fa 1553config AMD_NUMA
3c2362e6
HH
1554 def_bool y
1555 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1556 depends on X86_64 && NUMA && PCI
8f9ca475 1557 ---help---
eec1d4fa
HR
1558 Enable AMD NUMA node topology detection. You should say Y here if
1559 you have a multi processor AMD system. This uses an old method to
1560 read the NUMA configuration directly from the builtin Northbridge
1561 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1562 which also takes priority if both are compiled in.
506f1d07
SR
1563
1564config X86_64_ACPI_NUMA
3c2362e6
HH
1565 def_bool y
1566 prompt "ACPI NUMA detection"
506f1d07
SR
1567 depends on X86_64 && NUMA && ACPI && PCI
1568 select ACPI_NUMA
8f9ca475 1569 ---help---
506f1d07
SR
1570 Enable ACPI SRAT based node topology detection.
1571
6ec6e0d9
SS
1572# Some NUMA nodes have memory ranges that span
1573# other nodes. Even though a pfn is valid and
1574# between a node's start and end pfns, it may not
1575# reside on that node. See memmap_init_zone()
1576# for details.
1577config NODES_SPAN_OTHER_NODES
1578 def_bool y
1579 depends on X86_64_ACPI_NUMA
1580
506f1d07
SR
1581config NUMA_EMU
1582 bool "NUMA emulation"
1b7e03ef 1583 depends on NUMA
8f9ca475 1584 ---help---
506f1d07
SR
1585 Enable NUMA emulation. A flat machine will be split
1586 into virtual nodes when booted with "numa=fake=N", where N is the
1587 number of nodes. This is only useful for debugging.
1588
1589config NODES_SHIFT
d25e26b6 1590 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1591 range 1 10
1592 default "10" if MAXSMP
506f1d07 1593 default "6" if X86_64
506f1d07
SR
1594 default "3"
1595 depends on NEED_MULTIPLE_NODES
8f9ca475 1596 ---help---
1184dc2f 1597 Specify the maximum number of NUMA Nodes available on the target
692105b8 1598 system. Increases memory reserved to accommodate various tables.
506f1d07 1599
506f1d07 1600config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1601 def_bool y
506f1d07 1602 depends on X86_32 && DISCONTIGMEM
506f1d07 1603
506f1d07
SR
1604config ARCH_FLATMEM_ENABLE
1605 def_bool y
3b16651f 1606 depends on X86_32 && !NUMA
506f1d07
SR
1607
1608config ARCH_DISCONTIGMEM_ENABLE
1609 def_bool y
b263295d 1610 depends on NUMA && X86_32
506f1d07
SR
1611
1612config ARCH_DISCONTIGMEM_DEFAULT
1613 def_bool y
b263295d
CL
1614 depends on NUMA && X86_32
1615
506f1d07
SR
1616config ARCH_SPARSEMEM_ENABLE
1617 def_bool y
6ea30386 1618 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1619 select SPARSEMEM_STATIC if X86_32
1620 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1621
3b16651f
TH
1622config ARCH_SPARSEMEM_DEFAULT
1623 def_bool y
1624 depends on X86_64
1625
506f1d07
SR
1626config ARCH_SELECT_MEMORY_MODEL
1627 def_bool y
b263295d 1628 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1629
1630config ARCH_MEMORY_PROBE
a0842b70 1631 bool "Enable sysfs memory/probe interface"
3120e25e 1632 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1633 help
1634 This option enables a sysfs memory/probe interface for testing.
1635 See Documentation/memory-hotplug.txt for more information.
1636 If you are unsure how to answer this question, answer N.
506f1d07 1637
3b16651f
TH
1638config ARCH_PROC_KCORE_TEXT
1639 def_bool y
1640 depends on X86_64 && PROC_KCORE
1641
a29815a3
AK
1642config ILLEGAL_POINTER_VALUE
1643 hex
1644 default 0 if X86_32
1645 default 0xdead000000000000 if X86_64
1646
7a67832c
DW
1647config X86_PMEM_LEGACY_DEVICE
1648 bool
1649
ec776ef6 1650config X86_PMEM_LEGACY
7a67832c 1651 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1652 depends on PHYS_ADDR_T_64BIT
1653 depends on BLK_DEV
7a67832c 1654 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1655 select LIBNVDIMM
ec776ef6
CH
1656 help
1657 Treat memory marked using the non-standard e820 type of 12 as used
1658 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1659 The kernel will offer these regions to the 'pmem' driver so
1660 they can be used for persistent storage.
1661
1662 Say Y if unsure.
1663
506f1d07
SR
1664config HIGHPTE
1665 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1666 depends on HIGHMEM
8f9ca475 1667 ---help---
506f1d07
SR
1668 The VM uses one page table entry for each page of physical memory.
1669 For systems with a lot of RAM, this can be wasteful of precious
1670 low memory. Setting this option will put user-space page table
1671 entries in high memory.
1672
9f077871 1673config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1674 bool "Check for low memory corruption"
1675 ---help---
1676 Periodically check for memory corruption in low memory, which
1677 is suspected to be caused by BIOS. Even when enabled in the
1678 configuration, it is disabled at runtime. Enable it by
1679 setting "memory_corruption_check=1" on the kernel command
1680 line. By default it scans the low 64k of memory every 60
1681 seconds; see the memory_corruption_check_size and
1682 memory_corruption_check_period parameters in
8c27ceff 1683 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1684
1685 When enabled with the default parameters, this option has
1686 almost no overhead, as it reserves a relatively small amount
1687 of memory and scans it infrequently. It both detects corruption
1688 and prevents it from affecting the running system.
1689
1690 It is, however, intended as a diagnostic tool; if repeatable
1691 BIOS-originated corruption always affects the same memory,
1692 you can use memmap= to prevent the kernel from using that
1693 memory.
9f077871 1694
c885df50 1695config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1696 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1697 depends on X86_CHECK_BIOS_CORRUPTION
1698 default y
8f9ca475
IM
1699 ---help---
1700 Set whether the default state of memory_corruption_check is
1701 on or off.
c885df50 1702
9ea77bdb 1703config X86_RESERVE_LOW
d0cd7425
PA
1704 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1705 default 64
1706 range 4 640
8f9ca475 1707 ---help---
d0cd7425
PA
1708 Specify the amount of low memory to reserve for the BIOS.
1709
1710 The first page contains BIOS data structures that the kernel
1711 must not use, so that page must always be reserved.
1712
1713 By default we reserve the first 64K of physical RAM, as a
1714 number of BIOSes are known to corrupt that memory range
1715 during events such as suspend/resume or monitor cable
1716 insertion, so it must not be used by the kernel.
fc381519 1717
d0cd7425
PA
1718 You can set this to 4 if you are absolutely sure that you
1719 trust the BIOS to get all its memory reservations and usages
1720 right. If you know your BIOS have problems beyond the
1721 default 64K area, you can set this to 640 to avoid using the
1722 entire low memory range.
fc381519 1723
d0cd7425
PA
1724 If you have doubts about the BIOS (e.g. suspend/resume does
1725 not work or there's kernel crashes after certain hardware
1726 hotplug events) then you might want to enable
1727 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1728 typical corruption patterns.
fc381519 1729
d0cd7425 1730 Leave this to the default value of 64 if you are unsure.
fc381519 1731
506f1d07
SR
1732config MATH_EMULATION
1733 bool
a5b9e5a2 1734 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1735 prompt "Math emulation" if X86_32
1736 ---help---
1737 Linux can emulate a math coprocessor (used for floating point
1738 operations) if you don't have one. 486DX and Pentium processors have
1739 a math coprocessor built in, 486SX and 386 do not, unless you added
1740 a 487DX or 387, respectively. (The messages during boot time can
1741 give you some hints here ["man dmesg"].) Everyone needs either a
1742 coprocessor or this emulation.
1743
1744 If you don't have a math coprocessor, you need to say Y here; if you
1745 say Y here even though you have a coprocessor, the coprocessor will
1746 be used nevertheless. (This behavior can be changed with the kernel
1747 command line option "no387", which comes handy if your coprocessor
1748 is broken. Try "man bootparam" or see the documentation of your boot
1749 loader (lilo or loadlin) about how to pass options to the kernel at
1750 boot time.) This means that it is a good idea to say Y here if you
1751 intend to use this kernel on different machines.
1752
1753 More information about the internals of the Linux math coprocessor
1754 emulation can be found in <file:arch/x86/math-emu/README>.
1755
1756 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1757 kernel, it won't hurt.
1758
1759config MTRR
6fc108a0 1760 def_bool y
6a108a14 1761 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1762 ---help---
1763 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1764 the Memory Type Range Registers (MTRRs) may be used to control
1765 processor access to memory ranges. This is most useful if you have
1766 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1767 allows bus write transfers to be combined into a larger transfer
1768 before bursting over the PCI/AGP bus. This can increase performance
1769 of image write operations 2.5 times or more. Saying Y here creates a
1770 /proc/mtrr file which may be used to manipulate your processor's
1771 MTRRs. Typically the X server should use this.
1772
1773 This code has a reasonably generic interface so that similar
1774 control registers on other processors can be easily supported
1775 as well:
1776
1777 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1778 Registers (ARRs) which provide a similar functionality to MTRRs. For
1779 these, the ARRs are used to emulate the MTRRs.
1780 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1781 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1782 write-combining. All of these processors are supported by this code
1783 and it makes sense to say Y here if you have one of them.
1784
1785 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1786 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1787 can lead to all sorts of problems, so it's good to say Y here.
1788
1789 You can safely say Y even if your machine doesn't have MTRRs, you'll
1790 just add about 9 KB to your kernel.
1791
7225e751 1792 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1793
95ffa243 1794config MTRR_SANITIZER
2ffb3501 1795 def_bool y
95ffa243
YL
1796 prompt "MTRR cleanup support"
1797 depends on MTRR
8f9ca475 1798 ---help---
aba3728c
TG
1799 Convert MTRR layout from continuous to discrete, so X drivers can
1800 add writeback entries.
95ffa243 1801
aba3728c 1802 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1803 The largest mtrr entry size for a continuous block can be set with
aba3728c 1804 mtrr_chunk_size.
95ffa243 1805
2ffb3501 1806 If unsure, say Y.
95ffa243
YL
1807
1808config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1809 int "MTRR cleanup enable value (0-1)"
1810 range 0 1
1811 default "0"
95ffa243 1812 depends on MTRR_SANITIZER
8f9ca475 1813 ---help---
f5098d62 1814 Enable mtrr cleanup default value
95ffa243 1815
12031a62
YL
1816config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1817 int "MTRR cleanup spare reg num (0-7)"
1818 range 0 7
1819 default "1"
1820 depends on MTRR_SANITIZER
8f9ca475 1821 ---help---
12031a62 1822 mtrr cleanup spare entries default, it can be changed via
aba3728c 1823 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1824
2e5d9c85 1825config X86_PAT
6fc108a0 1826 def_bool y
6a108a14 1827 prompt "x86 PAT support" if EXPERT
2a8a2719 1828 depends on MTRR
8f9ca475 1829 ---help---
2e5d9c85 1830 Use PAT attributes to setup page level cache control.
042b78e4 1831
2e5d9c85 1832 PATs are the modern equivalents of MTRRs and are much more
1833 flexible than MTRRs.
1834
1835 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1836 spontaneous reboots) or a non-working video driver.
2e5d9c85 1837
1838 If unsure, say Y.
1839
46cf98cd
VP
1840config ARCH_USES_PG_UNCACHED
1841 def_bool y
1842 depends on X86_PAT
1843
628c6246
PA
1844config ARCH_RANDOM
1845 def_bool y
1846 prompt "x86 architectural random number generator" if EXPERT
1847 ---help---
1848 Enable the x86 architectural RDRAND instruction
1849 (Intel Bull Mountain technology) to generate random numbers.
1850 If supported, this is a high bandwidth, cryptographically
1851 secure hardware random number generator.
1852
51ae4a2d
PA
1853config X86_SMAP
1854 def_bool y
1855 prompt "Supervisor Mode Access Prevention" if EXPERT
1856 ---help---
1857 Supervisor Mode Access Prevention (SMAP) is a security
1858 feature in newer Intel processors. There is a small
1859 performance cost if this enabled and turned on; there is
1860 also a small increase in the kernel size if this is enabled.
1861
1862 If unsure, say Y.
1863
aa35f896 1864config X86_INTEL_UMIP
796ebc81 1865 def_bool y
aa35f896
RN
1866 depends on CPU_SUP_INTEL
1867 prompt "Intel User Mode Instruction Prevention" if EXPERT
1868 ---help---
1869 The User Mode Instruction Prevention (UMIP) is a security
1870 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1871 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1872 or STR instructions are executed in user mode. These instructions
1873 unnecessarily expose information about the hardware state.
1874
1875 The vast majority of applications do not use these instructions.
1876 For the very few that do, software emulation is provided in
1877 specific cases in protected and virtual-8086 modes. Emulated
1878 results are dummy.
aa35f896 1879
72e9b5fe
DH
1880config X86_INTEL_MPX
1881 prompt "Intel MPX (Memory Protection Extensions)"
1882 def_bool n
df3735c5
RR
1883 # Note: only available in 64-bit mode due to VMA flags shortage
1884 depends on CPU_SUP_INTEL && X86_64
1885 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1886 ---help---
1887 MPX provides hardware features that can be used in
1888 conjunction with compiler-instrumented code to check
1889 memory references. It is designed to detect buffer
1890 overflow or underflow bugs.
1891
1892 This option enables running applications which are
1893 instrumented or otherwise use MPX. It does not use MPX
1894 itself inside the kernel or to protect the kernel
1895 against bad memory references.
1896
1897 Enabling this option will make the kernel larger:
1898 ~8k of kernel text and 36 bytes of data on a 64-bit
1899 defconfig. It adds a long to the 'mm_struct' which
1900 will increase the kernel memory overhead of each
1901 process and adds some branches to paths used during
1902 exec() and munmap().
1903
1904 For details, see Documentation/x86/intel_mpx.txt
1905
1906 If unsure, say N.
1907
35e97790 1908config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1909 prompt "Intel Memory Protection Keys"
35e97790 1910 def_bool y
284244a9 1911 # Note: only available in 64-bit mode
35e97790 1912 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1913 select ARCH_USES_HIGH_VMA_FLAGS
1914 select ARCH_HAS_PKEYS
284244a9
DH
1915 ---help---
1916 Memory Protection Keys provides a mechanism for enforcing
1917 page-based protections, but without requiring modification of the
1918 page tables when an application changes protection domains.
1919
1920 For details, see Documentation/x86/protection-keys.txt
1921
1922 If unsure, say y.
35e97790 1923
506f1d07 1924config EFI
9ba16087 1925 bool "EFI runtime service support"
5b83683f 1926 depends on ACPI
f6ce5002 1927 select UCS2_STRING
022ee6c5 1928 select EFI_RUNTIME_WRAPPERS
506f1d07 1929 ---help---
8f9ca475
IM
1930 This enables the kernel to use EFI runtime services that are
1931 available (such as the EFI variable services).
506f1d07 1932
8f9ca475
IM
1933 This option is only useful on systems that have EFI firmware.
1934 In addition, you should use the latest ELILO loader available
1935 at <http://elilo.sourceforge.net> in order to take advantage
1936 of EFI runtime services. However, even with this option, the
1937 resultant kernel should continue to boot on existing non-EFI
1938 platforms.
506f1d07 1939
291f3632
MF
1940config EFI_STUB
1941 bool "EFI stub support"
b16d8c23 1942 depends on EFI && !X86_USE_3DNOW
7b2a583a 1943 select RELOCATABLE
291f3632
MF
1944 ---help---
1945 This kernel feature allows a bzImage to be loaded directly
1946 by EFI firmware without the use of a bootloader.
1947
4172fe2f 1948 See Documentation/efi-stub.txt for more information.
0c759662 1949
7d453eee
MF
1950config EFI_MIXED
1951 bool "EFI mixed-mode support"
1952 depends on EFI_STUB && X86_64
1953 ---help---
1954 Enabling this feature allows a 64-bit kernel to be booted
1955 on a 32-bit firmware, provided that your CPU supports 64-bit
1956 mode.
1957
1958 Note that it is not possible to boot a mixed-mode enabled
1959 kernel via the EFI boot stub - a bootloader that supports
1960 the EFI handover protocol must be used.
1961
1962 If unsure, say N.
1963
506f1d07 1964config SECCOMP
3c2362e6
HH
1965 def_bool y
1966 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1967 ---help---
506f1d07
SR
1968 This kernel feature is useful for number crunching applications
1969 that may need to compute untrusted bytecode during their
1970 execution. By using pipes or other transports made available to
1971 the process as file descriptors supporting the read/write
1972 syscalls, it's possible to isolate those applications in
1973 their own address space using seccomp. Once seccomp is
9c0bbee8 1974 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1975 and the task is only allowed to execute a few safe syscalls
1976 defined by each seccomp mode.
1977
1978 If unsure, say Y. Only embedded should say N here.
1979
8636a1f9 1980source "kernel/Kconfig.hz"
506f1d07
SR
1981
1982config KEXEC
1983 bool "kexec system call"
2965faa5 1984 select KEXEC_CORE
8f9ca475 1985 ---help---
506f1d07
SR
1986 kexec is a system call that implements the ability to shutdown your
1987 current kernel, and to start another kernel. It is like a reboot
1988 but it is independent of the system firmware. And like a reboot
1989 you can start any kernel with it, not just Linux.
1990
1991 The name comes from the similarity to the exec system call.
1992
1993 It is an ongoing process to be certain the hardware in a machine
1994 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1995 initially work for you. As of this writing the exact hardware
1996 interface is strongly in flux, so no good recommendation can be
1997 made.
506f1d07 1998
74ca317c
VG
1999config KEXEC_FILE
2000 bool "kexec file based system call"
2965faa5 2001 select KEXEC_CORE
74ca317c 2002 select BUILD_BIN2C
74ca317c
VG
2003 depends on X86_64
2004 depends on CRYPTO=y
2005 depends on CRYPTO_SHA256=y
2006 ---help---
2007 This is new version of kexec system call. This system call is
2008 file based and takes file descriptors as system call argument
2009 for kernel and initramfs as opposed to list of segments as
2010 accepted by previous system call.
2011
b799a09f
AT
2012config ARCH_HAS_KEXEC_PURGATORY
2013 def_bool KEXEC_FILE
2014
8e7d8381
VG
2015config KEXEC_VERIFY_SIG
2016 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2017 depends on KEXEC_FILE
8e7d8381
VG
2018 ---help---
2019 This option makes kernel signature verification mandatory for
d8eb8940
BP
2020 the kexec_file_load() syscall.
2021
2022 In addition to that option, you need to enable signature
2023 verification for the corresponding kernel image type being
2024 loaded in order for this to work.
8e7d8381
VG
2025
2026config KEXEC_BZIMAGE_VERIFY_SIG
2027 bool "Enable bzImage signature verification support"
2028 depends on KEXEC_VERIFY_SIG
2029 depends on SIGNED_PE_FILE_VERIFICATION
2030 select SYSTEM_TRUSTED_KEYRING
2031 ---help---
2032 Enable bzImage signature verification support.
2033
506f1d07 2034config CRASH_DUMP
04b69447 2035 bool "kernel crash dumps"
506f1d07 2036 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2037 ---help---
506f1d07
SR
2038 Generate crash dump after being started by kexec.
2039 This should be normally only set in special crash dump kernels
2040 which are loaded in the main kernel with kexec-tools into
2041 a specially reserved region and then later executed after
2042 a crash by kdump/kexec. The crash dump kernel must be compiled
2043 to a memory address not used by the main kernel or BIOS using
2044 PHYSICAL_START, or it must be built as a relocatable image
2045 (CONFIG_RELOCATABLE=y).
2046 For more details see Documentation/kdump/kdump.txt
2047
3ab83521 2048config KEXEC_JUMP
6ea30386 2049 bool "kexec jump"
fee7b0d8 2050 depends on KEXEC && HIBERNATION
8f9ca475 2051 ---help---
89081d17
HY
2052 Jump between original kernel and kexeced kernel and invoke
2053 code in physical address mode via KEXEC
3ab83521 2054
506f1d07 2055config PHYSICAL_START
6a108a14 2056 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2057 default "0x1000000"
8f9ca475 2058 ---help---
506f1d07
SR
2059 This gives the physical address where the kernel is loaded.
2060
2061 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2062 bzImage will decompress itself to above physical address and
2063 run from there. Otherwise, bzImage will run from the address where
2064 it has been loaded by the boot loader and will ignore above physical
2065 address.
2066
2067 In normal kdump cases one does not have to set/change this option
2068 as now bzImage can be compiled as a completely relocatable image
2069 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2070 address. This option is mainly useful for the folks who don't want
2071 to use a bzImage for capturing the crash dump and want to use a
2072 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2073 to be specifically compiled to run from a specific memory area
2074 (normally a reserved region) and this option comes handy.
2075
ceefccc9
PA
2076 So if you are using bzImage for capturing the crash dump,
2077 leave the value here unchanged to 0x1000000 and set
2078 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2079 for capturing the crash dump change this value to start of
2080 the reserved region. In other words, it can be set based on
2081 the "X" value as specified in the "crashkernel=YM@XM"
2082 command line boot parameter passed to the panic-ed
2083 kernel. Please take a look at Documentation/kdump/kdump.txt
2084 for more details about crash dumps.
506f1d07
SR
2085
2086 Usage of bzImage for capturing the crash dump is recommended as
2087 one does not have to build two kernels. Same kernel can be used
2088 as production kernel and capture kernel. Above option should have
2089 gone away after relocatable bzImage support is introduced. But it
2090 is present because there are users out there who continue to use
2091 vmlinux for dump capture. This option should go away down the
2092 line.
2093
2094 Don't change this unless you know what you are doing.
2095
2096config RELOCATABLE
26717808
PA
2097 bool "Build a relocatable kernel"
2098 default y
8f9ca475 2099 ---help---
506f1d07
SR
2100 This builds a kernel image that retains relocation information
2101 so it can be loaded someplace besides the default 1MB.
2102 The relocations tend to make the kernel binary about 10% larger,
2103 but are discarded at runtime.
2104
2105 One use is for the kexec on panic case where the recovery kernel
2106 must live at a different physical address than the primary
2107 kernel.
2108
2109 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2110 it has been loaded at and the compile time physical address
8ab3820f 2111 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2112
8ab3820f 2113config RANDOMIZE_BASE
e8581e3d 2114 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2115 depends on RELOCATABLE
6807c846 2116 default y
8ab3820f 2117 ---help---
e8581e3d
BH
2118 In support of Kernel Address Space Layout Randomization (KASLR),
2119 this randomizes the physical address at which the kernel image
2120 is decompressed and the virtual address where the kernel
2121 image is mapped, as a security feature that deters exploit
2122 attempts relying on knowledge of the location of kernel
2123 code internals.
2124
ed9f007e
KC
2125 On 64-bit, the kernel physical and virtual addresses are
2126 randomized separately. The physical address will be anywhere
2127 between 16MB and the top of physical memory (up to 64TB). The
2128 virtual address will be randomized from 16MB up to 1GB (9 bits
2129 of entropy). Note that this also reduces the memory space
2130 available to kernel modules from 1.5GB to 1GB.
2131
2132 On 32-bit, the kernel physical and virtual addresses are
2133 randomized together. They will be randomized from 16MB up to
2134 512MB (8 bits of entropy).
e8581e3d
BH
2135
2136 Entropy is generated using the RDRAND instruction if it is
2137 supported. If RDTSC is supported, its value is mixed into
2138 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2139 supported, then entropy is read from the i8254 timer. The
2140 usable entropy is limited by the kernel being built using
2141 2GB addressing, and that PHYSICAL_ALIGN must be at a
2142 minimum of 2MB. As a result, only 10 bits of entropy are
2143 theoretically possible, but the implementations are further
2144 limited due to memory layouts.
e8581e3d 2145
6807c846 2146 If unsure, say Y.
8ab3820f
KC
2147
2148# Relocation on x86 needs some additional build support
845adf72
PA
2149config X86_NEED_RELOCS
2150 def_bool y
8ab3820f 2151 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2152
506f1d07 2153config PHYSICAL_ALIGN
a0215061 2154 hex "Alignment value to which kernel should be aligned"
8ab3820f 2155 default "0x200000"
a0215061
KC
2156 range 0x2000 0x1000000 if X86_32
2157 range 0x200000 0x1000000 if X86_64
8f9ca475 2158 ---help---
506f1d07
SR
2159 This value puts the alignment restrictions on physical address
2160 where kernel is loaded and run from. Kernel is compiled for an
2161 address which meets above alignment restriction.
2162
2163 If bootloader loads the kernel at a non-aligned address and
2164 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2165 address aligned to above value and run from there.
2166
2167 If bootloader loads the kernel at a non-aligned address and
2168 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2169 load address and decompress itself to the address it has been
2170 compiled for and run from there. The address for which kernel is
2171 compiled already meets above alignment restrictions. Hence the
2172 end result is that kernel runs from a physical address meeting
2173 above alignment restrictions.
2174
a0215061
KC
2175 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2176 this value must be a multiple of 0x200000.
2177
506f1d07
SR
2178 Don't change this unless you know what you are doing.
2179
eedb92ab
KS
2180config DYNAMIC_MEMORY_LAYOUT
2181 bool
2182 ---help---
2183 This option makes base addresses of vmalloc and vmemmap as well as
2184 __PAGE_OFFSET movable during boot.
2185
0483e1fa
TG
2186config RANDOMIZE_MEMORY
2187 bool "Randomize the kernel memory sections"
2188 depends on X86_64
2189 depends on RANDOMIZE_BASE
eedb92ab 2190 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2191 default RANDOMIZE_BASE
2192 ---help---
2193 Randomizes the base virtual address of kernel memory sections
2194 (physical memory mapping, vmalloc & vmemmap). This security feature
2195 makes exploits relying on predictable memory locations less reliable.
2196
2197 The order of allocations remains unchanged. Entropy is generated in
2198 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2199 configuration have in average 30,000 different possible virtual
2200 addresses for each memory section.
2201
6807c846 2202 If unsure, say Y.
0483e1fa 2203
90397a41
TG
2204config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2205 hex "Physical memory mapping padding" if EXPERT
2206 depends on RANDOMIZE_MEMORY
2207 default "0xa" if MEMORY_HOTPLUG
2208 default "0x0"
2209 range 0x1 0x40 if MEMORY_HOTPLUG
2210 range 0x0 0x40
2211 ---help---
2212 Define the padding in terabytes added to the existing physical
2213 memory size during kernel memory randomization. It is useful
2214 for memory hotplug support but reduces the entropy available for
2215 address randomization.
2216
2217 If unsure, leave at the default value.
2218
506f1d07 2219config HOTPLUG_CPU
7c13e6a3 2220 bool "Support for hot-pluggable CPUs"
40b31360 2221 depends on SMP
506f1d07 2222 ---help---
7c13e6a3
DS
2223 Say Y here to allow turning CPUs off and on. CPUs can be
2224 controlled through /sys/devices/system/cpu.
2225 ( Note: power management support will enable this option
2226 automatically on SMP systems. )
2227 Say N if you want to disable CPU hotplug.
506f1d07 2228
80aa1dff
FY
2229config BOOTPARAM_HOTPLUG_CPU0
2230 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2231 depends on HOTPLUG_CPU
80aa1dff
FY
2232 ---help---
2233 Set whether default state of cpu0_hotpluggable is on or off.
2234
2235 Say Y here to enable CPU0 hotplug by default. If this switch
2236 is turned on, there is no need to give cpu0_hotplug kernel
2237 parameter and the CPU0 hotplug feature is enabled by default.
2238
2239 Please note: there are two known CPU0 dependencies if you want
2240 to enable the CPU0 hotplug feature either by this switch or by
2241 cpu0_hotplug kernel parameter.
2242
2243 First, resume from hibernate or suspend always starts from CPU0.
2244 So hibernate and suspend are prevented if CPU0 is offline.
2245
2246 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2247 offline if any interrupt can not migrate out of CPU0. There may
2248 be other CPU0 dependencies.
2249
2250 Please make sure the dependencies are under your control before
2251 you enable this feature.
2252
2253 Say N if you don't want to enable CPU0 hotplug feature by default.
2254 You still can enable the CPU0 hotplug feature at boot by kernel
2255 parameter cpu0_hotplug.
2256
a71c8bc5
FY
2257config DEBUG_HOTPLUG_CPU0
2258 def_bool n
2259 prompt "Debug CPU0 hotplug"
2c922cd0 2260 depends on HOTPLUG_CPU
a71c8bc5
FY
2261 ---help---
2262 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2263 soon as possible and boots up userspace with CPU0 offlined. User
2264 can online CPU0 back after boot time.
2265
2266 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2267 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2268 compilation or giving cpu0_hotplug kernel parameter at boot.
2269
2270 If unsure, say N.
2271
506f1d07 2272config COMPAT_VDSO
b0b49f26
AL
2273 def_bool n
2274 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2275 depends on COMPAT_32
8f9ca475 2276 ---help---
b0b49f26
AL
2277 Certain buggy versions of glibc will crash if they are
2278 presented with a 32-bit vDSO that is not mapped at the address
2279 indicated in its segment table.
e84446de 2280
b0b49f26
AL
2281 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2282 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2283 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2284 the only released version with the bug, but OpenSUSE 9
2285 contains a buggy "glibc 2.3.2".
506f1d07 2286
b0b49f26
AL
2287 The symptom of the bug is that everything crashes on startup, saying:
2288 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2289
2290 Saying Y here changes the default value of the vdso32 boot
2291 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2292 This works around the glibc bug but hurts performance.
2293
2294 If unsure, say N: if you are compiling your own kernel, you
2295 are unlikely to be using a buggy version of glibc.
506f1d07 2296
3dc33bd3
KC
2297choice
2298 prompt "vsyscall table for legacy applications"
2299 depends on X86_64
2300 default LEGACY_VSYSCALL_EMULATE
2301 help
2302 Legacy user code that does not know how to find the vDSO expects
2303 to be able to issue three syscalls by calling fixed addresses in
2304 kernel space. Since this location is not randomized with ASLR,
2305 it can be used to assist security vulnerability exploitation.
2306
2307 This setting can be changed at boot time via the kernel command
076ca272 2308 line parameter vsyscall=[emulate|none].
3dc33bd3
KC
2309
2310 On a system with recent enough glibc (2.14 or newer) and no
2311 static binaries, you can say None without a performance penalty
2312 to improve security.
2313
2314 If unsure, select "Emulate".
2315
3dc33bd3
KC
2316 config LEGACY_VSYSCALL_EMULATE
2317 bool "Emulate"
2318 help
2319 The kernel traps and emulates calls into the fixed
2320 vsyscall address mapping. This makes the mapping
2321 non-executable, but it still contains known contents,
2322 which could be used in certain rare security vulnerability
2323 exploits. This configuration is recommended when userspace
2324 still uses the vsyscall area.
2325
2326 config LEGACY_VSYSCALL_NONE
2327 bool "None"
2328 help
2329 There will be no vsyscall mapping at all. This will
2330 eliminate any risk of ASLR bypass due to the vsyscall
2331 fixed address mapping. Attempts to use the vsyscalls
2332 will be reported to dmesg, so that either old or
2333 malicious userspace programs can be identified.
2334
2335endchoice
2336
516cbf37
TB
2337config CMDLINE_BOOL
2338 bool "Built-in kernel command line"
8f9ca475 2339 ---help---
516cbf37
TB
2340 Allow for specifying boot arguments to the kernel at
2341 build time. On some systems (e.g. embedded ones), it is
2342 necessary or convenient to provide some or all of the
2343 kernel boot arguments with the kernel itself (that is,
2344 to not rely on the boot loader to provide them.)
2345
2346 To compile command line arguments into the kernel,
2347 set this option to 'Y', then fill in the
69711ca1 2348 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2349
2350 Systems with fully functional boot loaders (i.e. non-embedded)
2351 should leave this option set to 'N'.
2352
2353config CMDLINE
2354 string "Built-in kernel command string"
2355 depends on CMDLINE_BOOL
2356 default ""
8f9ca475 2357 ---help---
516cbf37
TB
2358 Enter arguments here that should be compiled into the kernel
2359 image and used at boot time. If the boot loader provides a
2360 command line at boot time, it is appended to this string to
2361 form the full kernel command line, when the system boots.
2362
2363 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2364 change this behavior.
2365
2366 In most cases, the command line (whether built-in or provided
2367 by the boot loader) should specify the device for the root
2368 file system.
2369
2370config CMDLINE_OVERRIDE
2371 bool "Built-in command line overrides boot loader arguments"
516cbf37 2372 depends on CMDLINE_BOOL
8f9ca475 2373 ---help---
516cbf37
TB
2374 Set this option to 'Y' to have the kernel ignore the boot loader
2375 command line, and use ONLY the built-in command line.
2376
2377 This is used to work around broken boot loaders. This should
2378 be set to 'N' under normal conditions.
2379
a5b9e5a2
AL
2380config MODIFY_LDT_SYSCALL
2381 bool "Enable the LDT (local descriptor table)" if EXPERT
2382 default y
2383 ---help---
2384 Linux can allow user programs to install a per-process x86
2385 Local Descriptor Table (LDT) using the modify_ldt(2) system
2386 call. This is required to run 16-bit or segmented code such as
2387 DOSEMU or some Wine programs. It is also used by some very old
2388 threading libraries.
2389
2390 Enabling this feature adds a small amount of overhead to
2391 context switches and increases the low-level kernel attack
2392 surface. Disabling it removes the modify_ldt(2) system call.
2393
2394 Saying 'N' here may make sense for embedded or server kernels.
2395
b700e7f0
SJ
2396source "kernel/livepatch/Kconfig"
2397
506f1d07
SR
2398endmenu
2399
3072e413
MH
2400config ARCH_HAS_ADD_PAGES
2401 def_bool y
2402 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2403
506f1d07
SR
2404config ARCH_ENABLE_MEMORY_HOTPLUG
2405 def_bool y
2406 depends on X86_64 || (X86_32 && HIGHMEM)
2407
35551053
GH
2408config ARCH_ENABLE_MEMORY_HOTREMOVE
2409 def_bool y
2410 depends on MEMORY_HOTPLUG
2411
e534c7c5 2412config USE_PERCPU_NUMA_NODE_ID
645a7919 2413 def_bool y
e534c7c5
LS
2414 depends on NUMA
2415
9491846f
KS
2416config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2417 def_bool y
2418 depends on X86_64 || X86_PAE
2419
c177c81e
NH
2420config ARCH_ENABLE_HUGEPAGE_MIGRATION
2421 def_bool y
2422 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2423
9c670ea3
NH
2424config ARCH_ENABLE_THP_MIGRATION
2425 def_bool y
2426 depends on X86_64 && TRANSPARENT_HUGEPAGE
2427
da85f865 2428menu "Power management and ACPI options"
e279b6c1
SR
2429
2430config ARCH_HIBERNATION_HEADER
3c2362e6 2431 def_bool y
44556530 2432 depends on HIBERNATION
e279b6c1
SR
2433
2434source "kernel/power/Kconfig"
2435
2436source "drivers/acpi/Kconfig"
2437
efafc8b2
FT
2438source "drivers/sfi/Kconfig"
2439
a6b68076 2440config X86_APM_BOOT
6fc108a0 2441 def_bool y
282e5aab 2442 depends on APM
a6b68076 2443
e279b6c1
SR
2444menuconfig APM
2445 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2446 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2447 ---help---
2448 APM is a BIOS specification for saving power using several different
2449 techniques. This is mostly useful for battery powered laptops with
2450 APM compliant BIOSes. If you say Y here, the system time will be
2451 reset after a RESUME operation, the /proc/apm device will provide
2452 battery status information, and user-space programs will receive
2453 notification of APM "events" (e.g. battery status change).
2454
2455 If you select "Y" here, you can disable actual use of the APM
2456 BIOS by passing the "apm=off" option to the kernel at boot time.
2457
2458 Note that the APM support is almost completely disabled for
2459 machines with more than one CPU.
2460
2461 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2462 and more information, read <file:Documentation/power/apm-acpi.txt>
2463 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2464 <http://www.tldp.org/docs.html#howto>.
2465
2466 This driver does not spin down disk drives (see the hdparm(8)
2467 manpage ("man 8 hdparm") for that), and it doesn't turn off
2468 VESA-compliant "green" monitors.
2469
2470 This driver does not support the TI 4000M TravelMate and the ACER
2471 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2472 desktop machines also don't have compliant BIOSes, and this driver
2473 may cause those machines to panic during the boot phase.
2474
2475 Generally, if you don't have a battery in your machine, there isn't
2476 much point in using this driver and you should say N. If you get
2477 random kernel OOPSes or reboots that don't seem to be related to
2478 anything, try disabling/enabling this option (or disabling/enabling
2479 APM in your BIOS).
2480
2481 Some other things you should try when experiencing seemingly random,
2482 "weird" problems:
2483
2484 1) make sure that you have enough swap space and that it is
2485 enabled.
2486 2) pass the "no-hlt" option to the kernel
2487 3) switch on floating point emulation in the kernel and pass
2488 the "no387" option to the kernel
2489 4) pass the "floppy=nodma" option to the kernel
2490 5) pass the "mem=4M" option to the kernel (thereby disabling
2491 all but the first 4 MB of RAM)
2492 6) make sure that the CPU is not over clocked.
2493 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2494 8) disable the cache from your BIOS settings
2495 9) install a fan for the video card or exchange video RAM
2496 10) install a better fan for the CPU
2497 11) exchange RAM chips
2498 12) exchange the motherboard.
2499
2500 To compile this driver as a module, choose M here: the
2501 module will be called apm.
2502
2503if APM
2504
2505config APM_IGNORE_USER_SUSPEND
2506 bool "Ignore USER SUSPEND"
8f9ca475 2507 ---help---
e279b6c1
SR
2508 This option will ignore USER SUSPEND requests. On machines with a
2509 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2510 series notebooks, it is necessary to say Y because of a BIOS bug.
2511
2512config APM_DO_ENABLE
2513 bool "Enable PM at boot time"
2514 ---help---
2515 Enable APM features at boot time. From page 36 of the APM BIOS
2516 specification: "When disabled, the APM BIOS does not automatically
2517 power manage devices, enter the Standby State, enter the Suspend
2518 State, or take power saving steps in response to CPU Idle calls."
2519 This driver will make CPU Idle calls when Linux is idle (unless this
2520 feature is turned off -- see "Do CPU IDLE calls", below). This
2521 should always save battery power, but more complicated APM features
2522 will be dependent on your BIOS implementation. You may need to turn
2523 this option off if your computer hangs at boot time when using APM
2524 support, or if it beeps continuously instead of suspending. Turn
2525 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2526 T400CDT. This is off by default since most machines do fine without
2527 this feature.
2528
2529config APM_CPU_IDLE
dd8af076 2530 depends on CPU_IDLE
e279b6c1 2531 bool "Make CPU Idle calls when idle"
8f9ca475 2532 ---help---
e279b6c1
SR
2533 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2534 On some machines, this can activate improved power savings, such as
2535 a slowed CPU clock rate, when the machine is idle. These idle calls
2536 are made after the idle loop has run for some length of time (e.g.,
2537 333 mS). On some machines, this will cause a hang at boot time or
2538 whenever the CPU becomes idle. (On machines with more than one CPU,
2539 this option does nothing.)
2540
2541config APM_DISPLAY_BLANK
2542 bool "Enable console blanking using APM"
8f9ca475 2543 ---help---
e279b6c1
SR
2544 Enable console blanking using the APM. Some laptops can use this to
2545 turn off the LCD backlight when the screen blanker of the Linux
2546 virtual console blanks the screen. Note that this is only used by
2547 the virtual console screen blanker, and won't turn off the backlight
2548 when using the X Window system. This also doesn't have anything to
2549 do with your VESA-compliant power-saving monitor. Further, this
2550 option doesn't work for all laptops -- it might not turn off your
2551 backlight at all, or it might print a lot of errors to the console,
2552 especially if you are using gpm.
2553
2554config APM_ALLOW_INTS
2555 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2556 ---help---
e279b6c1
SR
2557 Normally we disable external interrupts while we are making calls to
2558 the APM BIOS as a measure to lessen the effects of a badly behaving
2559 BIOS implementation. The BIOS should reenable interrupts if it
2560 needs to. Unfortunately, some BIOSes do not -- especially those in
2561 many of the newer IBM Thinkpads. If you experience hangs when you
2562 suspend, try setting this to Y. Otherwise, say N.
2563
e279b6c1
SR
2564endif # APM
2565
bb0a56ec 2566source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2567
2568source "drivers/cpuidle/Kconfig"
2569
27471fdb
AH
2570source "drivers/idle/Kconfig"
2571
e279b6c1
SR
2572endmenu
2573
2574
2575menu "Bus options (PCI etc.)"
2576
e279b6c1
SR
2577choice
2578 prompt "PCI access mode"
efefa6f6 2579 depends on X86_32 && PCI
e279b6c1
SR
2580 default PCI_GOANY
2581 ---help---
2582 On PCI systems, the BIOS can be used to detect the PCI devices and
2583 determine their configuration. However, some old PCI motherboards
2584 have BIOS bugs and may crash if this is done. Also, some embedded
2585 PCI-based systems don't have any BIOS at all. Linux can also try to
2586 detect the PCI hardware directly without using the BIOS.
2587
2588 With this option, you can specify how Linux should detect the
2589 PCI devices. If you choose "BIOS", the BIOS will be used,
2590 if you choose "Direct", the BIOS won't be used, and if you
2591 choose "MMConfig", then PCI Express MMCONFIG will be used.
2592 If you choose "Any", the kernel will try MMCONFIG, then the
2593 direct access method and falls back to the BIOS if that doesn't
2594 work. If unsure, go with the default, which is "Any".
2595
2596config PCI_GOBIOS
2597 bool "BIOS"
2598
2599config PCI_GOMMCONFIG
2600 bool "MMConfig"
2601
2602config PCI_GODIRECT
2603 bool "Direct"
2604
3ef0e1f8 2605config PCI_GOOLPC
76fb6570 2606 bool "OLPC XO-1"
3ef0e1f8
AS
2607 depends on OLPC
2608
2bdd1b03
AS
2609config PCI_GOANY
2610 bool "Any"
2611
e279b6c1
SR
2612endchoice
2613
2614config PCI_BIOS
3c2362e6 2615 def_bool y
efefa6f6 2616 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2617
2618# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2619config PCI_DIRECT
3c2362e6 2620 def_bool y
0aba496f 2621 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2622
2623config PCI_MMCONFIG
b45c9f36
JK
2624 bool "Support mmconfig PCI config space access" if X86_64
2625 default y
8364e1f8 2626 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2627 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2628
3ef0e1f8 2629config PCI_OLPC
2bdd1b03
AS
2630 def_bool y
2631 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2632
b5401a96
AN
2633config PCI_XEN
2634 def_bool y
2635 depends on PCI && XEN
2636 select SWIOTLB_XEN
2637
8364e1f8
JK
2638config MMCONF_FAM10H
2639 def_bool y
2640 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2641
3f6ea84a 2642config PCI_CNB20LE_QUIRK
6a108a14 2643 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2644 depends on PCI
3f6ea84a
IS
2645 help
2646 Read the PCI windows out of the CNB20LE host bridge. This allows
2647 PCI hotplug to work on systems with the CNB20LE chipset which do
2648 not have ACPI.
2649
64a5fed6
BH
2650 There's no public spec for this chipset, and this functionality
2651 is known to be incomplete.
2652
2653 You should say N unless you know you need this.
2654
3a495511 2655config ISA_BUS
17a2a129 2656 bool "ISA bus support on modern systems" if EXPERT
3a495511 2657 help
17a2a129
WBG
2658 Expose ISA bus device drivers and options available for selection and
2659 configuration. Enable this option if your target machine has an ISA
2660 bus. ISA is an older system, displaced by PCI and newer bus
2661 architectures -- if your target machine is modern, it probably does
2662 not have an ISA bus.
3a495511
WBG
2663
2664 If unsure, say N.
2665
1c00f016 2666# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2667config ISA_DMA_API
1c00f016
DR
2668 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2669 default y
2670 help
2671 Enables ISA-style DMA support for devices requiring such controllers.
2672 If unsure, say Y.
e279b6c1 2673
51e68d05
LT
2674if X86_32
2675
e279b6c1
SR
2676config ISA
2677 bool "ISA support"
8f9ca475 2678 ---help---
e279b6c1
SR
2679 Find out whether you have ISA slots on your motherboard. ISA is the
2680 name of a bus system, i.e. the way the CPU talks to the other stuff
2681 inside your box. Other bus systems are PCI, EISA, MicroChannel
2682 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2683 newer boards don't support it. If you have ISA, say Y, otherwise N.
2684
e279b6c1
SR
2685config SCx200
2686 tristate "NatSemi SCx200 support"
8f9ca475 2687 ---help---
e279b6c1
SR
2688 This provides basic support for National Semiconductor's
2689 (now AMD's) Geode processors. The driver probes for the
2690 PCI-IDs of several on-chip devices, so its a good dependency
2691 for other scx200_* drivers.
2692
2693 If compiled as a module, the driver is named scx200.
2694
2695config SCx200HR_TIMER
2696 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2697 depends on SCx200
e279b6c1 2698 default y
8f9ca475 2699 ---help---
e279b6c1
SR
2700 This driver provides a clocksource built upon the on-chip
2701 27MHz high-resolution timer. Its also a workaround for
2702 NSC Geode SC-1100's buggy TSC, which loses time when the
2703 processor goes idle (as is done by the scheduler). The
2704 other workaround is idle=poll boot option.
2705
3ef0e1f8
AS
2706config OLPC
2707 bool "One Laptop Per Child support"
54008979 2708 depends on !X86_PAE
3c554946 2709 select GPIOLIB
dc3119e7 2710 select OF
45bb1674 2711 select OF_PROMTREE
b4e51854 2712 select IRQ_DOMAIN
8f9ca475 2713 ---help---
3ef0e1f8
AS
2714 Add support for detecting the unique features of the OLPC
2715 XO hardware.
2716
a3128588
DD
2717config OLPC_XO1_PM
2718 bool "OLPC XO-1 Power Management"
fa112cf1 2719 depends on OLPC && MFD_CS5535=y && PM_SLEEP
bf1ebf00 2720 ---help---
97c4cb71 2721 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2722
cfee9597
DD
2723config OLPC_XO1_RTC
2724 bool "OLPC XO-1 Real Time Clock"
2725 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2726 ---help---
2727 Add support for the XO-1 real time clock, which can be used as a
2728 programmable wakeup source.
2729
7feda8e9
DD
2730config OLPC_XO1_SCI
2731 bool "OLPC XO-1 SCI extras"
92e830f2 2732 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2733 depends on INPUT=y
d8d01a63 2734 select POWER_SUPPLY
7feda8e9
DD
2735 ---help---
2736 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2737 - EC-driven system wakeups
7feda8e9 2738 - Power button
7bc74b3d 2739 - Ebook switch
2cf2baea 2740 - Lid switch
e1040ac6
DD
2741 - AC adapter status updates
2742 - Battery status updates
7feda8e9 2743
a0f30f59
DD
2744config OLPC_XO15_SCI
2745 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2746 depends on OLPC && ACPI
2747 select POWER_SUPPLY
a0f30f59
DD
2748 ---help---
2749 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2750 - EC-driven system wakeups
2751 - AC adapter status updates
2752 - Battery status updates
bf1ebf00 2753
d4f3e350
EW
2754config ALIX
2755 bool "PCEngines ALIX System Support (LED setup)"
2756 select GPIOLIB
2757 ---help---
2758 This option enables system support for the PCEngines ALIX.
2759 At present this just sets up LEDs for GPIO control on
2760 ALIX2/3/6 boards. However, other system specific setup should
2761 get added here.
2762
2763 Note: You must still enable the drivers for GPIO and LED support
2764 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2765
2766 Note: You have to set alix.force=1 for boards with Award BIOS.
2767
da4e3302
PP
2768config NET5501
2769 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2770 select GPIOLIB
2771 ---help---
2772 This option enables system support for the Soekris Engineering net5501.
2773
3197059a
PP
2774config GEOS
2775 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2776 select GPIOLIB
2777 depends on DMI
2778 ---help---
2779 This option enables system support for the Traverse Technologies GEOS.
2780
7d029125
VD
2781config TS5500
2782 bool "Technologic Systems TS-5500 platform support"
2783 depends on MELAN
2784 select CHECK_SIGNATURE
2785 select NEW_LEDS
2786 select LEDS_CLASS
2787 ---help---
2788 This option enables system support for the Technologic Systems TS-5500.
2789
bc0120fd
SR
2790endif # X86_32
2791
23ac4ae8 2792config AMD_NB
e279b6c1 2793 def_bool y
0e152cd7 2794 depends on CPU_SUP_AMD && PCI
e279b6c1 2795
e3263ab3
DR
2796config X86_SYSFB
2797 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2798 help
2799 Firmwares often provide initial graphics framebuffers so the BIOS,
2800 bootloader or kernel can show basic video-output during boot for
2801 user-guidance and debugging. Historically, x86 used the VESA BIOS
2802 Extensions and EFI-framebuffers for this, which are mostly limited
2803 to x86.
2804 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2805 framebuffers so the new generic system-framebuffer drivers can be
2806 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2807 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DR
2808 drivers like efifb, vesafb and uvesafb can pick it up.
2809 If this option is not selected, all system framebuffers are always
2810 marked as fallback platform framebuffers as usual.
2811
2812 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2813 not be able to pick up generic system framebuffers if this option
2814 is selected. You are highly encouraged to enable simplefb as
2815 replacement if you select this option. simplefb can correctly deal
2816 with generic system framebuffers. But you should still keep vesafb
2817 and others enabled as fallback if a system framebuffer is
2818 incompatible with simplefb.
2819
2820 If unsure, say Y.
2821
e279b6c1
SR
2822endmenu
2823
2824
1572497c 2825menu "Binary Emulations"
e279b6c1
SR
2826
2827config IA32_EMULATION
2828 bool "IA32 Emulation"
2829 depends on X86_64
39f88911 2830 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2831 select BINFMT_ELF
a97f52e6 2832 select COMPAT_BINFMT_ELF
39f88911 2833 select COMPAT_OLD_SIGACTION
8f9ca475 2834 ---help---
5fd92e65
L
2835 Include code to run legacy 32-bit programs under a
2836 64-bit kernel. You should likely turn this on, unless you're
2837 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2838
2839config IA32_AOUT
8f9ca475
IM
2840 tristate "IA32 a.out support"
2841 depends on IA32_EMULATION
eac61655 2842 depends on BROKEN
8f9ca475
IM
2843 ---help---
2844 Support old a.out binaries in the 32bit emulation.
e279b6c1 2845
0bf62763 2846config X86_X32
6ea30386 2847 bool "x32 ABI for 64-bit mode"
9b54050b 2848 depends on X86_64
5fd92e65
L
2849 ---help---
2850 Include code to run binaries for the x32 native 32-bit ABI
2851 for 64-bit processors. An x32 process gets access to the
2852 full 64-bit register file and wide data path while leaving
2853 pointers at 32 bits for smaller memory footprint.
2854
2855 You will need a recent binutils (2.22 or later) with
2856 elf32_x86_64 support enabled to compile a kernel with this
2857 option set.
2858
953fee1d
IM
2859config COMPAT_32
2860 def_bool y
2861 depends on IA32_EMULATION || X86_32
2862 select HAVE_UID16
2863 select OLD_SIGSUSPEND3
2864
e279b6c1 2865config COMPAT
3c2362e6 2866 def_bool y
0bf62763 2867 depends on IA32_EMULATION || X86_X32
e279b6c1 2868
3120e25e 2869if COMPAT
e279b6c1 2870config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2871 def_bool y
e279b6c1
SR
2872
2873config SYSVIPC_COMPAT
3c2362e6 2874 def_bool y
3120e25e 2875 depends on SYSVIPC
3120e25e 2876endif
ee009e4a 2877
e279b6c1
SR
2878endmenu
2879
2880
e5beae16
KP
2881config HAVE_ATOMIC_IOMAP
2882 def_bool y
2883 depends on X86_32
2884
4692d77f
AR
2885config X86_DEV_DMA_OPS
2886 bool
83125a3a 2887 depends on X86_64 || STA2X11
4692d77f 2888
f7219a53
AR
2889config X86_DMA_REMAP
2890 bool
83125a3a 2891 depends on STA2X11
f7219a53 2892
e585513b
KS
2893config HAVE_GENERIC_GUP
2894 def_bool y
2895
e279b6c1
SR
2896source "drivers/firmware/Kconfig"
2897
edf88417 2898source "arch/x86/kvm/Kconfig"