Merge branch 'proc-cmdline'
[linux-2.6-block.git] / arch / x86 / Kconfig
CommitLineData
b2441318 1# SPDX-License-Identifier: GPL-2.0
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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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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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11 def_bool y
12 depends on !64BIT
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13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
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SR
21
22config X86_64
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JB
23 def_bool y
24 depends on 64BIT
d94e0685 25 # Options that are inherently 64-bit kernel only:
e1073d1e 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
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IM
27 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
f616ab59 31 select NEED_DMA_MAP_STATE
09230cbc 32 select SWIOTLB
d94e0685 33 select X86_DEV_DMA_OPS
f8781c4a 34 select ARCH_HAS_SYSCALL_WRAPPER
1032c0ba 35
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IM
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40# ported to 32-bit as well. )
41#
8d5fffb9 42config X86
3c2362e6 43 def_bool y
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IM
44 #
45 # Note: keep this list sorted alphabetically
46 #
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47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
49 select ANON_INODES
50 select ARCH_CLOCKSOURCE_DATA
51 select ARCH_DISCARD_MEMBLOCK
c763ea26 52 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 53 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 54 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 55 select ARCH_HAS_ELF_RANDOMIZE
72d93104 56 select ARCH_HAS_FAST_MULTIPLIER
316d097c 57 select ARCH_HAS_FILTER_PGPROT
6974f0c4 58 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 59 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 60 select ARCH_HAS_KCOV if X86_64
10bcc80e 61 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 62 select ARCH_HAS_PMEM_API if X86_64
3010a5ea 63 select ARCH_HAS_PTE_SPECIAL
39208aa7 64 select ARCH_HAS_REFCOUNT
0aed55af 65 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
8780356e 66 select ARCH_HAS_UACCESS_MCSAFE if X86_64
d2852a22 67 select ARCH_HAS_SET_MEMORY
6471b825 68 select ARCH_HAS_SG_CHAIN
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LA
69 select ARCH_HAS_STRICT_KERNEL_RWX
70 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 71 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
c6d30853 72 select ARCH_HAS_UBSAN_SANITIZE_ALL
65f7d049 73 select ARCH_HAS_ZONE_DEVICE if X86_64
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74 select ARCH_HAVE_NMI_SAFE_CMPXCHG
75 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 76 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 77 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 78 select ARCH_SUPPORTS_ATOMIC_RMW
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79 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
80 select ARCH_USE_BUILTIN_BSWAP
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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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86 select BUILDTIME_EXTABLE_SORT
87 select CLKEVT_I8253
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88 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
89 select CLOCKSOURCE_WATCHDOG
6471b825 90 select DCACHE_WORD_ACCESS
fec777c3 91 select DMA_DIRECT_OPS
45471cd9
LT
92 select EDAC_ATOMIC_SCRUB
93 select EDAC_SUPPORT
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IM
94 select GENERIC_CLOCKEVENTS
95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
96 select GENERIC_CLOCKEVENTS_MIN_ADJUST
97 select GENERIC_CMOS_UPDATE
98 select GENERIC_CPU_AUTOPROBE
61dc0f55 99 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 100 select GENERIC_EARLY_IOREMAP
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IM
101 select GENERIC_FIND_FIRST_BIT
102 select GENERIC_IOMAP
c7d6c9dd 103 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 104 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 105 select GENERIC_IRQ_MIGRATION if SMP
6471b825 106 select GENERIC_IRQ_PROBE
c201c917 107 select GENERIC_IRQ_RESERVATION_MODE
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IM
108 select GENERIC_IRQ_SHOW
109 select GENERIC_PENDING_IRQ if SMP
110 select GENERIC_SMP_IDLE_THREAD
111 select GENERIC_STRNCPY_FROM_USER
112 select GENERIC_STRNLEN_USER
113 select GENERIC_TIME_VSYSCALL
7edaeb68 114 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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IM
115 select HAVE_ACPI_APEI if ACPI
116 select HAVE_ACPI_APEI_NMI if ACPI
117 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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118 select HAVE_ARCH_AUDITSYSCALL
119 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
120 select HAVE_ARCH_JUMP_LABEL
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
6471b825 126 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 127 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
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IM
128 select HAVE_ARCH_TRACEHOOK
129 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 131 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 132 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
133 select HAVE_CC_STACKPROTECTOR
134 select HAVE_CMPXCHG_DOUBLE
135 select HAVE_CMPXCHG_LOCAL
136 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 137 select HAVE_COPY_THREAD_TLS
cf4db259 138 select HAVE_C_RECORDMCOUNT
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IM
139 select HAVE_DEBUG_KMEMLEAK
140 select HAVE_DEBUG_STACKOVERFLOW
6471b825 141 select HAVE_DMA_CONTIGUOUS
677aa9f7 142 select HAVE_DYNAMIC_FTRACE
06aeaaea 143 select HAVE_DYNAMIC_FTRACE_WITH_REGS
03f5781b 144 select HAVE_EBPF_JIT
58340a07 145 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 146 select HAVE_EXIT_THREAD
644e0e8d 147 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 148 select HAVE_FTRACE_MCOUNT_RECORD
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149 select HAVE_FUNCTION_GRAPH_TRACER
150 select HAVE_FUNCTION_TRACER
6b90bd4b 151 select HAVE_GCC_PLUGINS
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152 select HAVE_HW_BREAKPOINT
153 select HAVE_IDE
154 select HAVE_IOREMAP_PROT
155 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
156 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 157 select HAVE_KERNEL_BZIP2
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158 select HAVE_KERNEL_GZIP
159 select HAVE_KERNEL_LZ4
2e9f3bdd 160 select HAVE_KERNEL_LZMA
13510997 161 select HAVE_KERNEL_LZO
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162 select HAVE_KERNEL_XZ
163 select HAVE_KPROBES
164 select HAVE_KPROBES_ON_FTRACE
540adea3 165 select HAVE_FUNCTION_ERROR_INJECTION
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166 select HAVE_KRETPROBES
167 select HAVE_KVM
168 select HAVE_LIVEPATCH if X86_64
169 select HAVE_MEMBLOCK
170 select HAVE_MEMBLOCK_NODE_MAP
0102752e 171 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 172 select HAVE_MOD_ARCH_SPECIFIC
42a0bb3f 173 select HAVE_NMI
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174 select HAVE_OPROFILE
175 select HAVE_OPTPROBES
176 select HAVE_PCSPKR_PLATFORM
177 select HAVE_PERF_EVENTS
c01d4323 178 select HAVE_PERF_EVENTS_NMI
92e5aae4 179 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
c5e63197 180 select HAVE_PERF_REGS
c5ebcedb 181 select HAVE_PERF_USER_STACK_DUMP
9e52fc2b 182 select HAVE_RCU_TABLE_FREE
6471b825 183 select HAVE_REGS_AND_STACK_ACCESS_API
11af8474 184 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
c763ea26 185 select HAVE_STACK_VALIDATION if X86_64
6471b825 186 select HAVE_SYSCALL_TRACEPOINTS
6471b825 187 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 188 select HAVE_USER_RETURN_NOTIFIER
c0185808 189 select IRQ_FORCED_THREADING
86596f0a 190 select NEED_SG_DMA_LENGTH
df65c1bc 191 select PCI_LOCKLESS_CONFIG
6471b825 192 select PERF_EVENTS
3195ef59 193 select RTC_LIB
d6faca40 194 select RTC_MC146818_LIB
6471b825 195 select SPARSE_IRQ
83fe27ea 196 select SRCU
6471b825 197 select SYSCTL_EXCEPTION_TRACE
15f4eae7 198 select THREAD_INFO_IN_TASK
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IM
199 select USER_STACKTRACE_SUPPORT
200 select VIRT_TO_BUS
6471b825 201 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 202
ba7e4d13 203config INSTRUCTION_DECODER
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204 def_bool y
205 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 206
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LT
207config OUTPUT_FORMAT
208 string
209 default "elf32-i386" if X86_32
210 default "elf64-x86-64" if X86_64
211
73531905 212config ARCH_DEFCONFIG
b9b39bfb 213 string
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SR
214 default "arch/x86/configs/i386_defconfig" if X86_32
215 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 216
8d5fffb9 217config LOCKDEP_SUPPORT
3c2362e6 218 def_bool y
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SR
219
220config STACKTRACE_SUPPORT
3c2362e6 221 def_bool y
8d5fffb9 222
8d5fffb9 223config MMU
3c2362e6 224 def_bool y
8d5fffb9 225
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DC
226config ARCH_MMAP_RND_BITS_MIN
227 default 28 if 64BIT
228 default 8
229
230config ARCH_MMAP_RND_BITS_MAX
231 default 32 if 64BIT
232 default 16
233
234config ARCH_MMAP_RND_COMPAT_BITS_MIN
235 default 8
236
237config ARCH_MMAP_RND_COMPAT_BITS_MAX
238 default 16
239
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SR
240config SBUS
241 bool
242
243config GENERIC_ISA_DMA
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244 def_bool y
245 depends on ISA_DMA_API
8d5fffb9 246
8d5fffb9 247config GENERIC_BUG
3c2362e6 248 def_bool y
8d5fffb9 249 depends on BUG
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250 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
251
252config GENERIC_BUG_RELATIVE_POINTERS
253 bool
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SR
254
255config GENERIC_HWEIGHT
3c2362e6 256 def_bool y
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257
258config ARCH_MAY_HAVE_PC_FDC
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259 def_bool y
260 depends on ISA_DMA_API
8d5fffb9 261
1032c0ba 262config RWSEM_XCHGADD_ALGORITHM
3120e25e 263 def_bool y
1032c0ba 264
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SR
265config GENERIC_CALIBRATE_DELAY
266 def_bool y
267
9a0b8415 268config ARCH_HAS_CPU_RELAX
269 def_bool y
270
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PE
271config ARCH_HAS_CACHE_LINE_SIZE
272 def_bool y
273
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DH
274config ARCH_HAS_FILTER_PGPROT
275 def_bool y
276
dd5af90a 277config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 278 def_bool y
b32ef636 279
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TH
280config NEED_PER_CPU_EMBED_FIRST_CHUNK
281 def_bool y
282
283config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
284 def_bool y
285
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JB
286config ARCH_HIBERNATION_POSSIBLE
287 def_bool y
801e4062 288
f4cb5700
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289config ARCH_SUSPEND_POSSIBLE
290 def_bool y
f4cb5700 291
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SC
292config ARCH_WANT_HUGE_PMD_SHARE
293 def_bool y
294
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SC
295config ARCH_WANT_GENERAL_HUGETLB
296 def_bool y
297
8d5fffb9 298config ZONE_DMA32
e0fd24a3 299 def_bool y if X86_64
8d5fffb9 300
8d5fffb9 301config AUDIT_ARCH
e0fd24a3 302 def_bool y if X86_64
8d5fffb9 303
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304config ARCH_SUPPORTS_OPTIMIZED_INLINING
305 def_bool y
306
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AM
307config ARCH_SUPPORTS_DEBUG_PAGEALLOC
308 def_bool y
309
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310config KASAN_SHADOW_OFFSET
311 hex
312 depends on KASAN
313 default 0xdffffc0000000000
314
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SW
315config HAVE_INTEL_TXT
316 def_bool y
6ea30386 317 depends on INTEL_IOMMU && ACPI
69575d38 318
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SR
319config X86_32_SMP
320 def_bool y
321 depends on X86_32 && SMP
322
323config X86_64_SMP
324 def_bool y
325 depends on X86_64 && SMP
326
ccbeed3a
TH
327config X86_32_LAZY_GS
328 def_bool y
2bc2f688 329 depends on X86_32 && CC_STACKPROTECTOR_NONE
ccbeed3a 330
2b144498
SD
331config ARCH_SUPPORTS_UPROBES
332 def_bool y
333
d20642f0
RH
334config FIX_EARLYCON_MEM
335 def_bool y
336
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KS
337config PGTABLE_LEVELS
338 int
77ef56e4 339 default 5 if X86_5LEVEL
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340 default 4 if X86_64
341 default 3 if X86_PAE
342 default 2
343
506f1d07 344source "init/Kconfig"
dc52ddc0 345source "kernel/Kconfig.freezer"
8d5fffb9 346
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SR
347menu "Processor type and features"
348
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RD
349config ZONE_DMA
350 bool "DMA memory allocation support" if EXPERT
351 default y
352 help
353 DMA memory allocation support allows devices with less than 32-bit
354 addressing to allocate within the first 16MB of address space.
355 Disable if no such devices will be used.
356
357 If unsure, say Y.
358
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SR
359config SMP
360 bool "Symmetric multi-processing support"
361 ---help---
362 This enables support for systems with more than one CPU. If you have
4a474157
RG
363 a system with only one CPU, say N. If you have a system with more
364 than one CPU, say Y.
506f1d07 365
4a474157 366 If you say N here, the kernel will run on uni- and multiprocessor
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SR
367 machines, but will use only one CPU of a multiprocessor machine. If
368 you say Y here, the kernel will run on many, but not all,
4a474157 369 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
370 will run faster if you say N here.
371
372 Note that if you say Y here and choose architecture "586" or
373 "Pentium" under "Processor family", the kernel will not work on 486
374 architectures. Similarly, multiprocessor kernels for the "PPro"
375 architecture may not work on all Pentium based boards.
376
377 People using multiprocessor machines who say Y here should also say
378 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
379 Management" code will be disabled if you say Y here.
380
395cf969 381 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 382 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
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SR
383 <http://www.tldp.org/docs.html#howto>.
384
385 If you don't know what to do here, say N.
386
9def39be
JT
387config X86_FEATURE_NAMES
388 bool "Processor feature human-readable names" if EMBEDDED
389 default y
390 ---help---
391 This option compiles in a table of x86 feature bits and corresponding
392 names. This is required to support /proc/cpuinfo and a few kernel
393 messages. You can disable this to save space, at the expense of
394 making those few kernel messages show numeric feature bits instead.
395
396 If in doubt, say Y.
397
06cd9a7d
YL
398config X86_X2APIC
399 bool "Support x2apic"
19e3d60d 400 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
401 ---help---
402 This enables x2apic support on CPUs that have this feature.
403
404 This allows 32-bit apic IDs (so it can support very large systems),
405 and accesses the local apic via MSRs not via mmio.
406
06cd9a7d
YL
407 If you don't know what to do here, say N.
408
6695c85b 409config X86_MPPARSE
6e87f9b7 410 bool "Enable MPS table" if ACPI || SFI
7a527688 411 default y
5ab74722 412 depends on X86_LOCAL_APIC
8f9ca475 413 ---help---
6695c85b
YL
414 For old smp systems that do not have proper acpi support. Newer systems
415 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 416
ddd70cf9
JN
417config GOLDFISH
418 def_bool y
419 depends on X86_GOLDFISH
420
76b04384
DW
421config RETPOLINE
422 bool "Avoid speculative indirect branches in kernel"
423 default y
d5028ba8 424 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
425 help
426 Compile kernel with the retpoline compiler options to guard against
427 kernel-to-user data leaks by avoiding speculative indirect
428 branches. Requires a compiler with -mindirect-branch=thunk-extern
429 support for full protection. The kernel may run slower.
430
431 Without compiler support, at least indirect branches in assembler
432 code are eliminated. Since this includes the syscall entry path,
433 it is not entirely pointless.
434
f01d7d51
VS
435config INTEL_RDT
436 bool "Intel Resource Director Technology support"
78e99b4a
FY
437 default n
438 depends on X86 && CPU_SUP_INTEL
59fe5a77 439 select KERNFS
78e99b4a 440 help
f01d7d51
VS
441 Select to enable resource allocation and monitoring which are
442 sub-features of Intel Resource Director Technology(RDT). More
443 information about RDT can be found in the Intel x86
444 Architecture Software Developer Manual.
78e99b4a
FY
445
446 Say N if unsure.
447
8425091f 448if X86_32
a0d0bb4d
RD
449config X86_BIGSMP
450 bool "Support for big SMP systems with more than 8 CPUs"
451 depends on SMP
452 ---help---
453 This option is needed for the systems that have more than 8 CPUs
454
c5c606d9
RT
455config X86_EXTENDED_PLATFORM
456 bool "Support for extended (non-PC) x86 platforms"
457 default y
8f9ca475 458 ---help---
06ac8346
IM
459 If you disable this option then the kernel will only support
460 standard PC platforms. (which covers the vast majority of
461 systems out there.)
462
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RT
463 If you enable this option then you'll be able to select support
464 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 465 Goldfish (Android emulator)
8425091f 466 AMD Elan
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RT
467 RDC R-321x SoC
468 SGI 320/540 (Visual Workstation)
83125a3a 469 STA2X11-based (e.g. Northville)
3f4110a4 470 Moorestown MID devices
06ac8346
IM
471
472 If you have one of these systems, or if you want to build a
473 generic distribution kernel, say Y here - otherwise say N.
8425091f 474endif
06ac8346 475
8425091f
RT
476if X86_64
477config X86_EXTENDED_PLATFORM
478 bool "Support for extended (non-PC) x86 platforms"
479 default y
480 ---help---
481 If you disable this option then the kernel will only support
482 standard PC platforms. (which covers the vast majority of
483 systems out there.)
484
485 If you enable this option then you'll be able to select support
486 for the following (non-PC) 64 bit x86 platforms:
44b111b5 487 Numascale NumaChip
8425091f
RT
488 ScaleMP vSMP
489 SGI Ultraviolet
490
491 If you have one of these systems, or if you want to build a
492 generic distribution kernel, say Y here - otherwise say N.
493endif
c5c606d9
RT
494# This is an alphabetically sorted list of 64 bit extended platforms
495# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
496config X86_NUMACHIP
497 bool "Numascale NumaChip"
498 depends on X86_64
499 depends on X86_EXTENDED_PLATFORM
500 depends on NUMA
501 depends on SMP
502 depends on X86_X2APIC
f9726bfd 503 depends on PCI_MMCONFIG
44b111b5
SP
504 ---help---
505 Adds support for Numascale NumaChip large-SMP systems. Needed to
506 enable more than ~168 cores.
507 If you don't have one of these, you should say N here.
506f1d07 508
c5c606d9
RT
509config X86_VSMP
510 bool "ScaleMP vSMP"
6276a074 511 select HYPERVISOR_GUEST
c5c606d9
RT
512 select PARAVIRT
513 depends on X86_64 && PCI
514 depends on X86_EXTENDED_PLATFORM
ead91d4b 515 depends on SMP
8f9ca475 516 ---help---
c5c606d9
RT
517 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
518 supposed to run on these EM64T-based machines. Only choose this option
519 if you have one of these machines.
5e3a77e9 520
03b48632
NP
521config X86_UV
522 bool "SGI Ultraviolet"
523 depends on X86_64
c5c606d9 524 depends on X86_EXTENDED_PLATFORM
54c28d29 525 depends on NUMA
1ecb4ae5 526 depends on EFI
9d6c26e7 527 depends on X86_X2APIC
1222e564 528 depends on PCI
8f9ca475 529 ---help---
03b48632
NP
530 This option is needed in order to support SGI Ultraviolet systems.
531 If you don't have one of these, you should say N here.
532
c5c606d9
RT
533# Following is an alphabetically sorted list of 32 bit extended platforms
534# Please maintain the alphabetic order if and when there are additions
506f1d07 535
ddd70cf9
JN
536config X86_GOLDFISH
537 bool "Goldfish (Virtual Platform)"
cb7b8023 538 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
539 ---help---
540 Enable support for the Goldfish virtual platform used primarily
541 for Android development. Unless you are building for the Android
542 Goldfish emulator say N here.
543
c751e17b
TG
544config X86_INTEL_CE
545 bool "CE4100 TV platform"
546 depends on PCI
547 depends on PCI_GODIRECT
6084a6e2 548 depends on X86_IO_APIC
c751e17b
TG
549 depends on X86_32
550 depends on X86_EXTENDED_PLATFORM
37bc9f50 551 select X86_REBOOTFIXUPS
da6b737b
SAS
552 select OF
553 select OF_EARLY_FLATTREE
c751e17b
TG
554 ---help---
555 Select for the Intel CE media processor (CE4100) SOC.
556 This option compiles in support for the CE4100 SOC for settop
557 boxes and media devices.
558
4cb9b00f 559config X86_INTEL_MID
43605ef1 560 bool "Intel MID platform support"
43605ef1 561 depends on X86_EXTENDED_PLATFORM
edc6bc78 562 depends on X86_PLATFORM_DEVICES
1ea7c673 563 depends on PCI
3fda5bb4 564 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 565 depends on X86_IO_APIC
7c9c3a1e 566 select SFI
4cb9b00f 567 select I2C
7c9c3a1e 568 select DW_APB_TIMER
1ea7c673 569 select APB_TIMER
1ea7c673 570 select INTEL_SCU_IPC
15a713df 571 select MFD_INTEL_MSIC
1ea7c673 572 ---help---
4cb9b00f
DC
573 Select to build a kernel capable of supporting Intel MID (Mobile
574 Internet Device) platform systems which do not have the PCI legacy
575 interfaces. If you are building for a PC class system say N here.
1ea7c673 576
4cb9b00f
DC
577 Intel MID platforms are based on an Intel processor and chipset which
578 consume less power than most of the x86 derivatives.
43605ef1 579
8bbc2a13
BD
580config X86_INTEL_QUARK
581 bool "Intel Quark platform support"
582 depends on X86_32
583 depends on X86_EXTENDED_PLATFORM
584 depends on X86_PLATFORM_DEVICES
585 depends on X86_TSC
586 depends on PCI
587 depends on PCI_GOANY
588 depends on X86_IO_APIC
589 select IOSF_MBI
590 select INTEL_IMR
9ab6eb51 591 select COMMON_CLK
8bbc2a13
BD
592 ---help---
593 Select to include support for Quark X1000 SoC.
594 Say Y here if you have a Quark based system such as the Arduino
595 compatible Intel Galileo.
596
3d48aab1
MW
597config X86_INTEL_LPSS
598 bool "Intel Low Power Subsystem Support"
eebb3e8d 599 depends on X86 && ACPI
3d48aab1 600 select COMMON_CLK
0f531431 601 select PINCTRL
eebb3e8d 602 select IOSF_MBI
3d48aab1
MW
603 ---help---
604 Select to build support for Intel Low Power Subsystem such as
605 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
606 things like clock tree (common clock framework) and pincontrol
607 which are needed by the LPSS peripheral drivers.
3d48aab1 608
92082a88
KX
609config X86_AMD_PLATFORM_DEVICE
610 bool "AMD ACPI2Platform devices support"
611 depends on ACPI
612 select COMMON_CLK
613 select PINCTRL
614 ---help---
615 Select to interpret AMD specific ACPI device to platform device
616 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
617 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
618 implemented under PINCTRL subsystem.
619
ced3ce76
DB
620config IOSF_MBI
621 tristate "Intel SoC IOSF Sideband support for SoC platforms"
622 depends on PCI
623 ---help---
624 This option enables sideband register access support for Intel SoC
625 platforms. On these platforms the IOSF sideband is used in lieu of
626 MSR's for some register accesses, mostly but not limited to thermal
627 and power. Drivers may query the availability of this device to
628 determine if they need the sideband in order to work on these
629 platforms. The sideband is available on the following SoC products.
630 This list is not meant to be exclusive.
631 - BayTrail
632 - Braswell
633 - Quark
634
635 You should say Y if you are running a kernel on one of these SoC's.
636
ed2226bd
DB
637config IOSF_MBI_DEBUG
638 bool "Enable IOSF sideband access through debugfs"
639 depends on IOSF_MBI && DEBUG_FS
640 ---help---
641 Select this option to expose the IOSF sideband access registers (MCR,
642 MDR, MCRX) through debugfs to write and read register information from
643 different units on the SoC. This is most useful for obtaining device
644 state information for debug and analysis. As this is a general access
645 mechanism, users of this option would have specific knowledge of the
646 device they want to access.
647
648 If you don't require the option or are in doubt, say N.
649
c5c606d9
RT
650config X86_RDC321X
651 bool "RDC R-321x SoC"
506f1d07 652 depends on X86_32
c5c606d9
RT
653 depends on X86_EXTENDED_PLATFORM
654 select M486
655 select X86_REBOOTFIXUPS
656 ---help---
657 This option is needed for RDC R-321x system-on-chip, also known
658 as R-8610-(G).
659 If you don't have one of these chips, you should say N here.
660
e0c7ae37 661config X86_32_NON_STANDARD
9c398017
IM
662 bool "Support non-standard 32-bit SMP architectures"
663 depends on X86_32 && SMP
c5c606d9 664 depends on X86_EXTENDED_PLATFORM
8f9ca475 665 ---help---
b5660ba7
PA
666 This option compiles in the bigsmp and STA2X11 default
667 subarchitectures. It is intended for a generic binary
668 kernel. If you select them all, kernel will probe it one by
669 one and will fallback to default.
d49c4288 670
c5c606d9 671# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 672
d949f36f 673config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 674 def_bool y
d949f36f
LT
675 # MCE code calls memory_failure():
676 depends on X86_MCE
677 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
678 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
679 depends on X86_64 || !SPARSEMEM
680 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 681
83125a3a
AR
682config STA2X11
683 bool "STA2X11 Companion Chip Support"
684 depends on X86_32_NON_STANDARD && PCI
b6e05477 685 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
686 select X86_DEV_DMA_OPS
687 select X86_DMA_REMAP
688 select SWIOTLB
689 select MFD_STA2X11
0145071b 690 select GPIOLIB
83125a3a
AR
691 default n
692 ---help---
693 This adds support for boards based on the STA2X11 IO-Hub,
694 a.k.a. "ConneXt". The chip is used in place of the standard
695 PC chipset, so all "standard" peripherals are missing. If this
696 option is selected the kernel will still be able to boot on
697 standard PC machines.
698
82148d1d
S
699config X86_32_IRIS
700 tristate "Eurobraille/Iris poweroff module"
701 depends on X86_32
702 ---help---
703 The Iris machines from EuroBraille do not have APM or ACPI support
704 to shut themselves down properly. A special I/O sequence is
705 needed to do so, which is what this module does at
706 kernel shutdown.
707
708 This is only for Iris machines from EuroBraille.
709
710 If unused, say N.
711
ae1e9130 712config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
713 def_bool y
714 prompt "Single-depth WCHAN output"
a87d0914 715 depends on X86
8f9ca475 716 ---help---
506f1d07
SR
717 Calculate simpler /proc/<PID>/wchan values. If this option
718 is disabled then wchan values will recurse back to the
719 caller function. This provides more accurate wchan values,
720 at the expense of slightly more scheduling overhead.
721
722 If in doubt, say "Y".
723
6276a074
BP
724menuconfig HYPERVISOR_GUEST
725 bool "Linux guest support"
8f9ca475 726 ---help---
6276a074
BP
727 Say Y here to enable options for running Linux under various hyper-
728 visors. This option enables basic hypervisor detection and platform
729 setup.
506f1d07 730
6276a074
BP
731 If you say N, all options in this submenu will be skipped and
732 disabled, and Linux guest support won't be built in.
506f1d07 733
6276a074 734if HYPERVISOR_GUEST
506f1d07 735
e61bd94a
EPH
736config PARAVIRT
737 bool "Enable paravirtualization code"
8f9ca475 738 ---help---
e61bd94a
EPH
739 This changes the kernel so it can modify itself when it is run
740 under a hypervisor, potentially improving performance significantly
741 over full virtualization. However, when run without a hypervisor
742 the kernel is theoretically slower and slightly larger.
743
6276a074
BP
744config PARAVIRT_DEBUG
745 bool "paravirt-ops debugging"
746 depends on PARAVIRT && DEBUG_KERNEL
747 ---help---
748 Enable to debug paravirt_ops internals. Specifically, BUG if
749 a paravirt_op is missing when it is called.
750
b4ecc126
JF
751config PARAVIRT_SPINLOCKS
752 bool "Paravirtualization layer for spinlocks"
6ea30386 753 depends on PARAVIRT && SMP
b4ecc126
JF
754 ---help---
755 Paravirtualized spinlocks allow a pvops backend to replace the
756 spinlock implementation with something virtualization-friendly
757 (for example, block the virtual CPU rather than spinning).
758
4c4e4f61
R
759 It has a minimal impact on native kernels and gives a nice performance
760 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 761
4c4e4f61 762 If you are unsure how to answer this question, answer Y.
b4ecc126 763
45e898b7
WL
764config QUEUED_LOCK_STAT
765 bool "Paravirt queued spinlock statistics"
cfd8983f 766 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
767 ---help---
768 Enable the collection of statistical data on the slowpath
769 behavior of paravirtualized queued spinlocks and report
770 them on debugfs.
771
6276a074 772source "arch/x86/xen/Kconfig"
7af192c9 773
6276a074
BP
774config KVM_GUEST
775 bool "KVM Guest support (including kvmclock)"
776 depends on PARAVIRT
777 select PARAVIRT_CLOCK
778 default y
8f9ca475 779 ---help---
6276a074
BP
780 This option enables various optimizations for running under the KVM
781 hypervisor. It includes a paravirtualized clock, so that instead
782 of relying on a PIT (or probably other) emulation by the
783 underlying device model, the host provides the guest with
784 timing infrastructure such as time of day, and system time
506f1d07 785
1e20eb85
SV
786config KVM_DEBUG_FS
787 bool "Enable debug information for KVM Guests in debugfs"
788 depends on KVM_GUEST && DEBUG_FS
789 default n
790 ---help---
791 This option enables collection of various statistics for KVM guest.
792 Statistics are displayed in debugfs filesystem. Enabling this option
793 may incur significant overhead.
794
6276a074
BP
795config PARAVIRT_TIME_ACCOUNTING
796 bool "Paravirtual steal time accounting"
797 depends on PARAVIRT
798 default n
8f9ca475 799 ---help---
6276a074
BP
800 Select this option to enable fine granularity task steal time
801 accounting. Time spent executing other tasks in parallel with
802 the current vCPU is discounted from the vCPU power. To account for
803 that, there can be a small performance impact.
804
805 If in doubt, say N here.
806
807config PARAVIRT_CLOCK
808 bool
97349135 809
4a362601
JK
810config JAILHOUSE_GUEST
811 bool "Jailhouse non-root cell support"
abde587b 812 depends on X86_64 && PCI
87e65d05 813 select X86_PM_TIMER
4a362601
JK
814 ---help---
815 This option allows to run Linux as guest in a Jailhouse non-root
816 cell. You can leave this option disabled if you only want to start
817 Jailhouse and run Linux afterwards in the root cell.
818
6276a074 819endif #HYPERVISOR_GUEST
97349135 820
08677214 821config NO_BOOTMEM
774ea0bc 822 def_bool y
08677214 823
506f1d07
SR
824source "arch/x86/Kconfig.cpu"
825
826config HPET_TIMER
3c2362e6 827 def_bool X86_64
506f1d07 828 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
829 ---help---
830 Use the IA-PC HPET (High Precision Event Timer) to manage
831 time in preference to the PIT and RTC, if a HPET is
832 present.
833 HPET is the next generation timer replacing legacy 8254s.
834 The HPET provides a stable time base on SMP
835 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
836 as it is off-chip. The interface used is documented
837 in the HPET spec, revision 1.
506f1d07 838
8f9ca475
IM
839 You can safely choose Y here. However, HPET will only be
840 activated if the platform and the BIOS support this feature.
841 Otherwise the 8254 will be used for timing services.
506f1d07 842
8f9ca475 843 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
844
845config HPET_EMULATE_RTC
3c2362e6 846 def_bool y
9d8af78b 847 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 848
bb24c471 849config APB_TIMER
933b9463
AC
850 def_bool y if X86_INTEL_MID
851 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 852 select DW_APB_TIMER
a0c3832a 853 depends on X86_INTEL_MID && SFI
bb24c471
JP
854 help
855 APB timer is the replacement for 8254, HPET on X86 MID platforms.
856 The APBT provides a stable time base on SMP
857 systems, unlike the TSC, but it is more expensive to access,
858 as it is off-chip. APB timers are always running regardless of CPU
859 C states, they are used as per CPU clockevent device when possible.
860
6a108a14 861# Mark as expert because too many people got it wrong.
506f1d07 862# The code disables itself when not needed.
7ae9392c
TP
863config DMI
864 default y
cf074402 865 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 866 bool "Enable DMI scanning" if EXPERT
8f9ca475 867 ---help---
7ae9392c
TP
868 Enabled scanning of DMI to identify machine quirks. Say Y
869 here unless you have verified that your setup is not
870 affected by entries in the DMI blacklist. Required by PNP
871 BIOS code.
872
506f1d07 873config GART_IOMMU
38901f1c 874 bool "Old AMD GART IOMMU support"
a4ce5a48 875 select IOMMU_HELPER
506f1d07 876 select SWIOTLB
23ac4ae8 877 depends on X86_64 && PCI && AMD_NB
8f9ca475 878 ---help---
ced3c42c
IM
879 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
880 GART based hardware IOMMUs.
881
882 The GART supports full DMA access for devices with 32-bit access
883 limitations, on systems with more than 3 GB. This is usually needed
884 for USB, sound, many IDE/SATA chipsets and some other devices.
885
886 Newer systems typically have a modern AMD IOMMU, supported via
887 the CONFIG_AMD_IOMMU=y config option.
888
889 In normal configurations this driver is only active when needed:
890 there's more than 3 GB of memory and the system contains a
891 32-bit limited device.
892
893 If unsure, say Y.
506f1d07
SR
894
895config CALGARY_IOMMU
896 bool "IBM Calgary IOMMU support"
a4ce5a48 897 select IOMMU_HELPER
506f1d07 898 select SWIOTLB
6ea30386 899 depends on X86_64 && PCI
8f9ca475 900 ---help---
506f1d07
SR
901 Support for hardware IOMMUs in IBM's xSeries x366 and x460
902 systems. Needed to run systems with more than 3GB of memory
903 properly with 32-bit PCI devices that do not support DAC
904 (Double Address Cycle). Calgary also supports bus level
905 isolation, where all DMAs pass through the IOMMU. This
906 prevents them from going anywhere except their intended
907 destination. This catches hard-to-find kernel bugs and
908 mis-behaving drivers and devices that do not use the DMA-API
909 properly to set up their DMA buffers. The IOMMU can be
910 turned off at boot time with the iommu=off parameter.
911 Normally the kernel will make the right choice by itself.
912 If unsure, say Y.
913
914config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
915 def_bool y
916 prompt "Should Calgary be enabled by default?"
506f1d07 917 depends on CALGARY_IOMMU
8f9ca475 918 ---help---
506f1d07
SR
919 Should Calgary be enabled by default? if you choose 'y', Calgary
920 will be used (if it exists). If you choose 'n', Calgary will not be
921 used even if it exists. If you choose 'n' and would like to use
922 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
923 If unsure, say Y.
506f1d07 924
1184dc2f 925config MAXSMP
ddb0c5a6 926 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 927 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 928 select CPUMASK_OFFSTACK
8f9ca475 929 ---help---
ddb0c5a6 930 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 931 If unsure, say N.
506f1d07 932
aec6487e
IM
933#
934# The maximum number of CPUs supported:
935#
936# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
937# and which can be configured interactively in the
938# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
939#
940# The ranges are different on 32-bit and 64-bit kernels, depending on
941# hardware capabilities and scalability features of the kernel.
942#
943# ( If MAXSMP is enabled we just use the highest possible value and disable
944# interactive configuration. )
945#
946
947config NR_CPUS_RANGE_BEGIN
a0d0bb4d 948 int
aec6487e
IM
949 default NR_CPUS_RANGE_END if MAXSMP
950 default 1 if !SMP
951 default 2
a0d0bb4d 952
aec6487e 953config NR_CPUS_RANGE_END
a0d0bb4d 954 int
aec6487e
IM
955 depends on X86_32
956 default 64 if SMP && X86_BIGSMP
957 default 8 if SMP && !X86_BIGSMP
958 default 1 if !SMP
a0d0bb4d 959
aec6487e 960config NR_CPUS_RANGE_END
a0d0bb4d 961 int
aec6487e
IM
962 depends on X86_64
963 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
964 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
965 default 1 if !SMP
a0d0bb4d 966
aec6487e 967config NR_CPUS_DEFAULT
a0d0bb4d
RD
968 int
969 depends on X86_32
aec6487e
IM
970 default 32 if X86_BIGSMP
971 default 8 if SMP
972 default 1 if !SMP
a0d0bb4d 973
aec6487e 974config NR_CPUS_DEFAULT
a0d0bb4d
RD
975 int
976 depends on X86_64
aec6487e
IM
977 default 8192 if MAXSMP
978 default 64 if SMP
979 default 1 if !SMP
a0d0bb4d 980
506f1d07 981config NR_CPUS
36f5101a 982 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
983 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
984 default NR_CPUS_DEFAULT
8f9ca475 985 ---help---
506f1d07 986 This allows you to specify the maximum number of CPUs which this
bb61ccc7 987 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 988 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
989 minimum value which makes sense is 2.
990
aec6487e
IM
991 This is purely to save memory: each supported CPU adds about 8KB
992 to the kernel image.
506f1d07
SR
993
994config SCHED_SMT
995 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 996 depends on SMP
8f9ca475 997 ---help---
506f1d07
SR
998 SMT scheduler support improves the CPU scheduler's decision making
999 when dealing with Intel Pentium 4 chips with HyperThreading at a
1000 cost of slightly increased overhead in some places. If unsure say
1001 N here.
1002
1003config SCHED_MC
3c2362e6
HH
1004 def_bool y
1005 prompt "Multi-core scheduler support"
c8e56d20 1006 depends on SMP
8f9ca475 1007 ---help---
506f1d07
SR
1008 Multi-core scheduler support improves the CPU scheduler's decision
1009 making when dealing with multi-core CPU chips at a cost of slightly
1010 increased overhead in some places. If unsure say N here.
1011
de966cf4
TC
1012config SCHED_MC_PRIO
1013 bool "CPU core priorities scheduler support"
0a21fc12
IM
1014 depends on SCHED_MC && CPU_SUP_INTEL
1015 select X86_INTEL_PSTATE
1016 select CPU_FREQ
de966cf4 1017 default y
5e76b2ab 1018 ---help---
0a21fc12
IM
1019 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1020 core ordering determined at manufacturing time, which allows
1021 certain cores to reach higher turbo frequencies (when running
1022 single threaded workloads) than others.
de966cf4 1023
0a21fc12
IM
1024 Enabling this kernel feature teaches the scheduler about
1025 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1026 scheduler's CPU selection logic accordingly, so that higher
1027 overall system performance can be achieved.
de966cf4 1028
0a21fc12 1029 This feature will have no effect on CPUs without this feature.
de966cf4 1030
0a21fc12 1031 If unsure say Y here.
5e76b2ab 1032
506f1d07
SR
1033source "kernel/Kconfig.preempt"
1034
30b8b006
TG
1035config UP_LATE_INIT
1036 def_bool y
ba360f88 1037 depends on !SMP && X86_LOCAL_APIC
30b8b006 1038
506f1d07 1039config X86_UP_APIC
50849eef
JB
1040 bool "Local APIC support on uniprocessors" if !PCI_MSI
1041 default PCI_MSI
38a1dfda 1042 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1043 ---help---
506f1d07
SR
1044 A local APIC (Advanced Programmable Interrupt Controller) is an
1045 integrated interrupt controller in the CPU. If you have a single-CPU
1046 system which has a processor with a local APIC, you can say Y here to
1047 enable and use it. If you say Y here even though your machine doesn't
1048 have a local APIC, then the kernel will still run with no slowdown at
1049 all. The local APIC supports CPU-generated self-interrupts (timer,
1050 performance counters), and the NMI watchdog which detects hard
1051 lockups.
1052
1053config X86_UP_IOAPIC
1054 bool "IO-APIC support on uniprocessors"
1055 depends on X86_UP_APIC
8f9ca475 1056 ---help---
506f1d07
SR
1057 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1058 SMP-capable replacement for PC-style interrupt controllers. Most
1059 SMP systems and many recent uniprocessor systems have one.
1060
1061 If you have a single-CPU system with an IO-APIC, you can say Y here
1062 to use it. If you say Y here even though your machine doesn't have
1063 an IO-APIC, then the kernel will still run with no slowdown at all.
1064
1065config X86_LOCAL_APIC
3c2362e6 1066 def_bool y
0dbc6078 1067 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1068 select IRQ_DOMAIN_HIERARCHY
52f518a3 1069 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1070
1071config X86_IO_APIC
b1da1e71
JB
1072 def_bool y
1073 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1074
41b9eb26
SA
1075config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1076 bool "Reroute for broken boot IRQs"
41b9eb26 1077 depends on X86_IO_APIC
8f9ca475 1078 ---help---
41b9eb26
SA
1079 This option enables a workaround that fixes a source of
1080 spurious interrupts. This is recommended when threaded
1081 interrupt handling is used on systems where the generation of
1082 superfluous "boot interrupts" cannot be disabled.
1083
1084 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1085 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1086 kernel does during interrupt handling). On chipsets where this
1087 boot IRQ generation cannot be disabled, this workaround keeps
1088 the original IRQ line masked so that only the equivalent "boot
1089 IRQ" is delivered to the CPUs. The workaround also tells the
1090 kernel to set up the IRQ handler on the boot IRQ line. In this
1091 way only one interrupt is delivered to the kernel. Otherwise
1092 the spurious second interrupt may cause the kernel to bring
1093 down (vital) interrupt lines.
1094
1095 Only affects "broken" chipsets. Interrupt sharing may be
1096 increased on these systems.
1097
506f1d07 1098config X86_MCE
bab9bc65 1099 bool "Machine Check / overheating reporting"
648ed940 1100 select GENERIC_ALLOCATOR
e57dbaf7 1101 default y
506f1d07 1102 ---help---
bab9bc65
AK
1103 Machine Check support allows the processor to notify the
1104 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1105 The action the kernel takes depends on the severity of the problem,
bab9bc65 1106 ranging from warning messages to halting the machine.
4efc0670 1107
5de97c9f
TL
1108config X86_MCELOG_LEGACY
1109 bool "Support for deprecated /dev/mcelog character device"
1110 depends on X86_MCE
1111 ---help---
1112 Enable support for /dev/mcelog which is needed by the old mcelog
1113 userspace logging daemon. Consider switching to the new generation
1114 rasdaemon solution.
1115
506f1d07 1116config X86_MCE_INTEL
3c2362e6
HH
1117 def_bool y
1118 prompt "Intel MCE features"
c1ebf835 1119 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1120 ---help---
506f1d07
SR
1121 Additional support for intel specific MCE features such as
1122 the thermal monitor.
1123
1124config X86_MCE_AMD
3c2362e6
HH
1125 def_bool y
1126 prompt "AMD MCE features"
f5382de9 1127 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1128 ---help---
506f1d07
SR
1129 Additional support for AMD specific MCE features such as
1130 the DRAM Error Threshold.
1131
4efc0670 1132config X86_ANCIENT_MCE
6fc108a0 1133 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1134 depends on X86_32 && X86_MCE
cd13adcc
HS
1135 ---help---
1136 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1137 systems. These typically need to be enabled explicitly on the command
cd13adcc 1138 line.
4efc0670 1139
b2762686
AK
1140config X86_MCE_THRESHOLD
1141 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1142 def_bool y
b2762686 1143
ea149b36 1144config X86_MCE_INJECT
bc8e80d5 1145 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1146 tristate "Machine check injector support"
1147 ---help---
1148 Provide support for injecting machine checks for testing purposes.
1149 If you don't know what a machine check is and you don't do kernel
1150 QA it is safe to say n.
1151
4efc0670
AK
1152config X86_THERMAL_VECTOR
1153 def_bool y
5bb38adc 1154 depends on X86_MCE_INTEL
4efc0670 1155
07dc900e 1156source "arch/x86/events/Kconfig"
e633c65a 1157
5aef51c3 1158config X86_LEGACY_VM86
1e642812 1159 bool "Legacy VM86 support"
5aef51c3 1160 default n
506f1d07 1161 depends on X86_32
8f9ca475 1162 ---help---
5aef51c3
AL
1163 This option allows user programs to put the CPU into V8086
1164 mode, which is an 80286-era approximation of 16-bit real mode.
1165
1166 Some very old versions of X and/or vbetool require this option
1167 for user mode setting. Similarly, DOSEMU will use it if
1168 available to accelerate real mode DOS programs. However, any
1169 recent version of DOSEMU, X, or vbetool should be fully
1170 functional even without kernel VM86 support, as they will all
1e642812
IM
1171 fall back to software emulation. Nevertheless, if you are using
1172 a 16-bit DOS program where 16-bit performance matters, vm86
1173 mode might be faster than emulation and you might want to
1174 enable this option.
5aef51c3 1175
1e642812
IM
1176 Note that any app that works on a 64-bit kernel is unlikely to
1177 need this option, as 64-bit kernels don't, and can't, support
1178 V8086 mode. This option is also unrelated to 16-bit protected
1179 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1180
1e642812
IM
1181 Enabling this option increases the complexity of the kernel
1182 and slows down exception handling a tiny bit.
5aef51c3 1183
1e642812 1184 If unsure, say N here.
5aef51c3
AL
1185
1186config VM86
1187 bool
1188 default X86_LEGACY_VM86
34273f41
PA
1189
1190config X86_16BIT
1191 bool "Enable support for 16-bit segments" if EXPERT
1192 default y
a5b9e5a2 1193 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1194 ---help---
1195 This option is required by programs like Wine to run 16-bit
1196 protected mode legacy code on x86 processors. Disabling
1197 this option saves about 300 bytes on i386, or around 6K text
1198 plus 16K runtime memory on x86-64,
1199
1200config X86_ESPFIX32
1201 def_bool y
1202 depends on X86_16BIT && X86_32
506f1d07 1203
197725de
PA
1204config X86_ESPFIX64
1205 def_bool y
34273f41 1206 depends on X86_16BIT && X86_64
506f1d07 1207
1ad83c85
AL
1208config X86_VSYSCALL_EMULATION
1209 bool "Enable vsyscall emulation" if EXPERT
1210 default y
1211 depends on X86_64
1212 ---help---
1213 This enables emulation of the legacy vsyscall page. Disabling
1214 it is roughly equivalent to booting with vsyscall=none, except
1215 that it will also disable the helpful warning if a program
1216 tries to use a vsyscall. With this option set to N, offending
1217 programs will just segfault, citing addresses of the form
1218 0xffffffffff600?00.
1219
1220 This option is required by many programs built before 2013, and
1221 care should be used even with newer programs if set to N.
1222
1223 Disabling this option saves about 7K of kernel size and
1224 possibly 4K of additional runtime pagetable memory.
1225
506f1d07
SR
1226config TOSHIBA
1227 tristate "Toshiba Laptop support"
1228 depends on X86_32
1229 ---help---
1230 This adds a driver to safely access the System Management Mode of
1231 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1232 not work on models with a Phoenix BIOS. The System Management Mode
1233 is used to set the BIOS and power saving options on Toshiba portables.
1234
1235 For information on utilities to make use of this driver see the
1236 Toshiba Linux utilities web site at:
1237 <http://www.buzzard.org.uk/toshiba/>.
1238
1239 Say Y if you intend to run this kernel on a Toshiba portable.
1240 Say N otherwise.
1241
1242config I8K
039ae585 1243 tristate "Dell i8k legacy laptop support"
949a9d70 1244 select HWMON
039ae585 1245 select SENSORS_DELL_SMM
506f1d07 1246 ---help---
039ae585
PR
1247 This option enables legacy /proc/i8k userspace interface in hwmon
1248 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1249 temperature and allows controlling fan speeds of Dell laptops via
1250 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1251 it reports also power and hotkey status. For fan speed control is
1252 needed userspace package i8kutils.
1253
1254 Say Y if you intend to run this kernel on old Dell laptops or want to
1255 use userspace package i8kutils.
506f1d07
SR
1256 Say N otherwise.
1257
1258config X86_REBOOTFIXUPS
9ba16087
JB
1259 bool "Enable X86 board specific fixups for reboot"
1260 depends on X86_32
506f1d07
SR
1261 ---help---
1262 This enables chipset and/or board specific fixups to be done
1263 in order to get reboot to work correctly. This is only needed on
1264 some combinations of hardware and BIOS. The symptom, for which
1265 this config is intended, is when reboot ends with a stalled/hung
1266 system.
1267
1268 Currently, the only fixup is for the Geode machines using
5e3a77e9 1269 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1270
1271 Say Y if you want to enable the fixup. Currently, it's safe to
1272 enable this option even if you don't need it.
1273 Say N otherwise.
1274
1275config MICROCODE
9a2bc335
BP
1276 bool "CPU microcode loading support"
1277 default y
80030e3d 1278 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1279 select FW_LOADER
1280 ---help---
1281 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1282 Intel and AMD processors. The Intel support is for the IA32 family,
1283 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1284 AMD support is for families 0x10 and later. You will obviously need
1285 the actual microcode binary data itself which is not shipped with
1286 the Linux kernel.
1287
1288 The preferred method to load microcode from a detached initrd is described
1897a969 1289 in Documentation/x86/microcode.txt. For that you need to enable
5f9c01aa
BP
1290 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1291 initrd for microcode blobs.
1292
c508c46e
BG
1293 In addition, you can build the microcode into the kernel. For that you
1294 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1295 config option.
506f1d07 1296
8d86f390 1297config MICROCODE_INTEL
e43f6e67 1298 bool "Intel microcode loading support"
8f9ca475
IM
1299 depends on MICROCODE
1300 default MICROCODE
1301 select FW_LOADER
1302 ---help---
1303 This options enables microcode patch loading support for Intel
1304 processors.
1305
b8989db9
A
1306 For the current Intel microcode data package go to
1307 <https://downloadcenter.intel.com> and search for
1308 'Linux Processor Microcode Data File'.
8d86f390 1309
80cc9f10 1310config MICROCODE_AMD
e43f6e67 1311 bool "AMD microcode loading support"
8f9ca475
IM
1312 depends on MICROCODE
1313 select FW_LOADER
1314 ---help---
1315 If you select this option, microcode patch loading support for AMD
1316 processors will be enabled.
80cc9f10 1317
8f9ca475 1318config MICROCODE_OLD_INTERFACE
3c2362e6 1319 def_bool y
506f1d07 1320 depends on MICROCODE
506f1d07
SR
1321
1322config X86_MSR
1323 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1324 ---help---
506f1d07
SR
1325 This device gives privileged processes access to the x86
1326 Model-Specific Registers (MSRs). It is a character device with
1327 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1328 MSR accesses are directed to a specific CPU on multi-processor
1329 systems.
1330
1331config X86_CPUID
1332 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1333 ---help---
506f1d07
SR
1334 This device gives processes access to the x86 CPUID instruction to
1335 be executed on a specific processor. It is a character device
1336 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1337 /dev/cpu/31/cpuid.
1338
1339choice
1340 prompt "High Memory Support"
6fc108a0 1341 default HIGHMEM4G
506f1d07
SR
1342 depends on X86_32
1343
1344config NOHIGHMEM
1345 bool "off"
506f1d07
SR
1346 ---help---
1347 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1348 However, the address space of 32-bit x86 processors is only 4
1349 Gigabytes large. That means that, if you have a large amount of
1350 physical memory, not all of it can be "permanently mapped" by the
1351 kernel. The physical memory that's not permanently mapped is called
1352 "high memory".
1353
1354 If you are compiling a kernel which will never run on a machine with
1355 more than 1 Gigabyte total physical RAM, answer "off" here (default
1356 choice and suitable for most users). This will result in a "3GB/1GB"
1357 split: 3GB are mapped so that each process sees a 3GB virtual memory
1358 space and the remaining part of the 4GB virtual memory space is used
1359 by the kernel to permanently map as much physical memory as
1360 possible.
1361
1362 If the machine has between 1 and 4 Gigabytes physical RAM, then
1363 answer "4GB" here.
1364
1365 If more than 4 Gigabytes is used then answer "64GB" here. This
1366 selection turns Intel PAE (Physical Address Extension) mode on.
1367 PAE implements 3-level paging on IA32 processors. PAE is fully
1368 supported by Linux, PAE mode is implemented on all recent Intel
1369 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1370 then the kernel will not boot on CPUs that don't support PAE!
1371
1372 The actual amount of total physical memory will either be
1373 auto detected or can be forced by using a kernel command line option
1374 such as "mem=256M". (Try "man bootparam" or see the documentation of
1375 your boot loader (lilo or loadlin) about how to pass options to the
1376 kernel at boot time.)
1377
1378 If unsure, say "off".
1379
1380config HIGHMEM4G
1381 bool "4GB"
8f9ca475 1382 ---help---
506f1d07
SR
1383 Select this if you have a 32-bit processor and between 1 and 4
1384 gigabytes of physical RAM.
1385
1386config HIGHMEM64G
1387 bool "64GB"
69b8d3fc 1388 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1389 select X86_PAE
8f9ca475 1390 ---help---
506f1d07
SR
1391 Select this if you have a 32-bit processor and more than 4
1392 gigabytes of physical RAM.
1393
1394endchoice
1395
1396choice
6a108a14 1397 prompt "Memory split" if EXPERT
506f1d07
SR
1398 default VMSPLIT_3G
1399 depends on X86_32
8f9ca475 1400 ---help---
506f1d07
SR
1401 Select the desired split between kernel and user memory.
1402
1403 If the address range available to the kernel is less than the
1404 physical memory installed, the remaining memory will be available
1405 as "high memory". Accessing high memory is a little more costly
1406 than low memory, as it needs to be mapped into the kernel first.
1407 Note that increasing the kernel address space limits the range
1408 available to user programs, making the address space there
1409 tighter. Selecting anything other than the default 3G/1G split
1410 will also likely make your kernel incompatible with binary-only
1411 kernel modules.
1412
1413 If you are not absolutely sure what you are doing, leave this
1414 option alone!
1415
1416 config VMSPLIT_3G
1417 bool "3G/1G user/kernel split"
1418 config VMSPLIT_3G_OPT
1419 depends on !X86_PAE
1420 bool "3G/1G user/kernel split (for full 1G low memory)"
1421 config VMSPLIT_2G
1422 bool "2G/2G user/kernel split"
1423 config VMSPLIT_2G_OPT
1424 depends on !X86_PAE
1425 bool "2G/2G user/kernel split (for full 2G low memory)"
1426 config VMSPLIT_1G
1427 bool "1G/3G user/kernel split"
1428endchoice
1429
1430config PAGE_OFFSET
1431 hex
1432 default 0xB0000000 if VMSPLIT_3G_OPT
1433 default 0x80000000 if VMSPLIT_2G
1434 default 0x78000000 if VMSPLIT_2G_OPT
1435 default 0x40000000 if VMSPLIT_1G
1436 default 0xC0000000
1437 depends on X86_32
1438
1439config HIGHMEM
3c2362e6 1440 def_bool y
506f1d07 1441 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1442
1443config X86_PAE
9ba16087 1444 bool "PAE (Physical Address Extension) Support"
506f1d07 1445 depends on X86_32 && !HIGHMEM4G
d4a451d5 1446 select PHYS_ADDR_T_64BIT
9d99c712 1447 select SWIOTLB
8f9ca475 1448 ---help---
506f1d07
SR
1449 PAE is required for NX support, and furthermore enables
1450 larger swapspace support for non-overcommit purposes. It
1451 has the cost of more pagetable lookup overhead, and also
1452 consumes more pagetable space per process.
1453
77ef56e4
KS
1454config X86_5LEVEL
1455 bool "Enable 5-level page tables support"
eedb92ab 1456 select DYNAMIC_MEMORY_LAYOUT
162434e7 1457 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1458 depends on X86_64
1459 ---help---
1460 5-level paging enables access to larger address space:
1461 upto 128 PiB of virtual address space and 4 PiB of
1462 physical address space.
1463
1464 It will be supported by future Intel CPUs.
1465
6657fca0
KS
1466 A kernel with the option enabled can be booted on machines that
1467 support 4- or 5-level paging.
77ef56e4
KS
1468
1469 See Documentation/x86/x86_64/5level-paging.txt for more
1470 information.
1471
1472 Say N if unsure.
1473
10971ab2 1474config X86_DIRECT_GBPAGES
e5008abe 1475 def_bool y
4675ff05 1476 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1477 ---help---
10971ab2
IM
1478 Certain kernel features effectively disable kernel
1479 linear 1 GB mappings (even if the CPU otherwise
1480 supports them), so don't confuse the user by printing
1481 that we have them enabled.
9e899816 1482
7744ccdb
TL
1483config ARCH_HAS_MEM_ENCRYPT
1484 def_bool y
1485
1486config AMD_MEM_ENCRYPT
1487 bool "AMD Secure Memory Encryption (SME) support"
1488 depends on X86_64 && CPU_SUP_AMD
1489 ---help---
1490 Say yes to enable support for the encryption of system memory.
1491 This requires an AMD processor that supports Secure Memory
1492 Encryption (SME).
1493
1494config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1495 bool "Activate AMD Secure Memory Encryption (SME) by default"
1496 default y
1497 depends on AMD_MEM_ENCRYPT
1498 ---help---
1499 Say yes to have system memory encrypted by default if running on
1500 an AMD processor that supports Secure Memory Encryption (SME).
1501
1502 If set to Y, then the encryption of system memory can be
1503 deactivated with the mem_encrypt=off command line option.
1504
1505 If set to N, then the encryption of system memory can be
1506 activated with the mem_encrypt=on command line option.
1507
f88a68fa
TL
1508config ARCH_USE_MEMREMAP_PROT
1509 def_bool y
1510 depends on AMD_MEM_ENCRYPT
1511
506f1d07
SR
1512# Common NUMA Features
1513config NUMA
fd51b2d7 1514 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1515 depends on SMP
b5660ba7
PA
1516 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1517 default y if X86_BIGSMP
8f9ca475 1518 ---help---
506f1d07 1519 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1520
506f1d07
SR
1521 The kernel will try to allocate memory used by a CPU on the
1522 local memory controller of the CPU and add some more
1523 NUMA awareness to the kernel.
1524
c280ea5e 1525 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1526 (or later), AMD Opteron, or EM64T NUMA.
1527
b5660ba7 1528 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1529 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1530
1531 Otherwise, you should say N.
506f1d07 1532
eec1d4fa 1533config AMD_NUMA
3c2362e6
HH
1534 def_bool y
1535 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1536 depends on X86_64 && NUMA && PCI
8f9ca475 1537 ---help---
eec1d4fa
HR
1538 Enable AMD NUMA node topology detection. You should say Y here if
1539 you have a multi processor AMD system. This uses an old method to
1540 read the NUMA configuration directly from the builtin Northbridge
1541 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1542 which also takes priority if both are compiled in.
506f1d07
SR
1543
1544config X86_64_ACPI_NUMA
3c2362e6
HH
1545 def_bool y
1546 prompt "ACPI NUMA detection"
506f1d07
SR
1547 depends on X86_64 && NUMA && ACPI && PCI
1548 select ACPI_NUMA
8f9ca475 1549 ---help---
506f1d07
SR
1550 Enable ACPI SRAT based node topology detection.
1551
6ec6e0d9
SS
1552# Some NUMA nodes have memory ranges that span
1553# other nodes. Even though a pfn is valid and
1554# between a node's start and end pfns, it may not
1555# reside on that node. See memmap_init_zone()
1556# for details.
1557config NODES_SPAN_OTHER_NODES
1558 def_bool y
1559 depends on X86_64_ACPI_NUMA
1560
506f1d07
SR
1561config NUMA_EMU
1562 bool "NUMA emulation"
1b7e03ef 1563 depends on NUMA
8f9ca475 1564 ---help---
506f1d07
SR
1565 Enable NUMA emulation. A flat machine will be split
1566 into virtual nodes when booted with "numa=fake=N", where N is the
1567 number of nodes. This is only useful for debugging.
1568
1569config NODES_SHIFT
d25e26b6 1570 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1571 range 1 10
1572 default "10" if MAXSMP
506f1d07 1573 default "6" if X86_64
506f1d07
SR
1574 default "3"
1575 depends on NEED_MULTIPLE_NODES
8f9ca475 1576 ---help---
1184dc2f 1577 Specify the maximum number of NUMA Nodes available on the target
692105b8 1578 system. Increases memory reserved to accommodate various tables.
506f1d07 1579
506f1d07 1580config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1581 def_bool y
506f1d07 1582 depends on X86_32 && DISCONTIGMEM
506f1d07 1583
506f1d07
SR
1584config ARCH_FLATMEM_ENABLE
1585 def_bool y
3b16651f 1586 depends on X86_32 && !NUMA
506f1d07
SR
1587
1588config ARCH_DISCONTIGMEM_ENABLE
1589 def_bool y
b263295d 1590 depends on NUMA && X86_32
506f1d07
SR
1591
1592config ARCH_DISCONTIGMEM_DEFAULT
1593 def_bool y
b263295d
CL
1594 depends on NUMA && X86_32
1595
506f1d07
SR
1596config ARCH_SPARSEMEM_ENABLE
1597 def_bool y
6ea30386 1598 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1599 select SPARSEMEM_STATIC if X86_32
1600 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1601
3b16651f
TH
1602config ARCH_SPARSEMEM_DEFAULT
1603 def_bool y
1604 depends on X86_64
1605
506f1d07
SR
1606config ARCH_SELECT_MEMORY_MODEL
1607 def_bool y
b263295d 1608 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1609
1610config ARCH_MEMORY_PROBE
a0842b70 1611 bool "Enable sysfs memory/probe interface"
3120e25e 1612 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1613 help
1614 This option enables a sysfs memory/probe interface for testing.
1615 See Documentation/memory-hotplug.txt for more information.
1616 If you are unsure how to answer this question, answer N.
506f1d07 1617
3b16651f
TH
1618config ARCH_PROC_KCORE_TEXT
1619 def_bool y
1620 depends on X86_64 && PROC_KCORE
1621
a29815a3
AK
1622config ILLEGAL_POINTER_VALUE
1623 hex
1624 default 0 if X86_32
1625 default 0xdead000000000000 if X86_64
1626
506f1d07
SR
1627source "mm/Kconfig"
1628
7a67832c
DW
1629config X86_PMEM_LEGACY_DEVICE
1630 bool
1631
ec776ef6 1632config X86_PMEM_LEGACY
7a67832c 1633 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1634 depends on PHYS_ADDR_T_64BIT
1635 depends on BLK_DEV
7a67832c 1636 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1637 select LIBNVDIMM
ec776ef6
CH
1638 help
1639 Treat memory marked using the non-standard e820 type of 12 as used
1640 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1641 The kernel will offer these regions to the 'pmem' driver so
1642 they can be used for persistent storage.
1643
1644 Say Y if unsure.
1645
506f1d07
SR
1646config HIGHPTE
1647 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1648 depends on HIGHMEM
8f9ca475 1649 ---help---
506f1d07
SR
1650 The VM uses one page table entry for each page of physical memory.
1651 For systems with a lot of RAM, this can be wasteful of precious
1652 low memory. Setting this option will put user-space page table
1653 entries in high memory.
1654
9f077871 1655config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1656 bool "Check for low memory corruption"
1657 ---help---
1658 Periodically check for memory corruption in low memory, which
1659 is suspected to be caused by BIOS. Even when enabled in the
1660 configuration, it is disabled at runtime. Enable it by
1661 setting "memory_corruption_check=1" on the kernel command
1662 line. By default it scans the low 64k of memory every 60
1663 seconds; see the memory_corruption_check_size and
1664 memory_corruption_check_period parameters in
8c27ceff 1665 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1666
1667 When enabled with the default parameters, this option has
1668 almost no overhead, as it reserves a relatively small amount
1669 of memory and scans it infrequently. It both detects corruption
1670 and prevents it from affecting the running system.
1671
1672 It is, however, intended as a diagnostic tool; if repeatable
1673 BIOS-originated corruption always affects the same memory,
1674 you can use memmap= to prevent the kernel from using that
1675 memory.
9f077871 1676
c885df50 1677config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1678 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1679 depends on X86_CHECK_BIOS_CORRUPTION
1680 default y
8f9ca475
IM
1681 ---help---
1682 Set whether the default state of memory_corruption_check is
1683 on or off.
c885df50 1684
9ea77bdb 1685config X86_RESERVE_LOW
d0cd7425
PA
1686 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1687 default 64
1688 range 4 640
8f9ca475 1689 ---help---
d0cd7425
PA
1690 Specify the amount of low memory to reserve for the BIOS.
1691
1692 The first page contains BIOS data structures that the kernel
1693 must not use, so that page must always be reserved.
1694
1695 By default we reserve the first 64K of physical RAM, as a
1696 number of BIOSes are known to corrupt that memory range
1697 during events such as suspend/resume or monitor cable
1698 insertion, so it must not be used by the kernel.
fc381519 1699
d0cd7425
PA
1700 You can set this to 4 if you are absolutely sure that you
1701 trust the BIOS to get all its memory reservations and usages
1702 right. If you know your BIOS have problems beyond the
1703 default 64K area, you can set this to 640 to avoid using the
1704 entire low memory range.
fc381519 1705
d0cd7425
PA
1706 If you have doubts about the BIOS (e.g. suspend/resume does
1707 not work or there's kernel crashes after certain hardware
1708 hotplug events) then you might want to enable
1709 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1710 typical corruption patterns.
fc381519 1711
d0cd7425 1712 Leave this to the default value of 64 if you are unsure.
fc381519 1713
506f1d07
SR
1714config MATH_EMULATION
1715 bool
a5b9e5a2 1716 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1717 prompt "Math emulation" if X86_32
1718 ---help---
1719 Linux can emulate a math coprocessor (used for floating point
1720 operations) if you don't have one. 486DX and Pentium processors have
1721 a math coprocessor built in, 486SX and 386 do not, unless you added
1722 a 487DX or 387, respectively. (The messages during boot time can
1723 give you some hints here ["man dmesg"].) Everyone needs either a
1724 coprocessor or this emulation.
1725
1726 If you don't have a math coprocessor, you need to say Y here; if you
1727 say Y here even though you have a coprocessor, the coprocessor will
1728 be used nevertheless. (This behavior can be changed with the kernel
1729 command line option "no387", which comes handy if your coprocessor
1730 is broken. Try "man bootparam" or see the documentation of your boot
1731 loader (lilo or loadlin) about how to pass options to the kernel at
1732 boot time.) This means that it is a good idea to say Y here if you
1733 intend to use this kernel on different machines.
1734
1735 More information about the internals of the Linux math coprocessor
1736 emulation can be found in <file:arch/x86/math-emu/README>.
1737
1738 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1739 kernel, it won't hurt.
1740
1741config MTRR
6fc108a0 1742 def_bool y
6a108a14 1743 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1744 ---help---
1745 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1746 the Memory Type Range Registers (MTRRs) may be used to control
1747 processor access to memory ranges. This is most useful if you have
1748 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1749 allows bus write transfers to be combined into a larger transfer
1750 before bursting over the PCI/AGP bus. This can increase performance
1751 of image write operations 2.5 times or more. Saying Y here creates a
1752 /proc/mtrr file which may be used to manipulate your processor's
1753 MTRRs. Typically the X server should use this.
1754
1755 This code has a reasonably generic interface so that similar
1756 control registers on other processors can be easily supported
1757 as well:
1758
1759 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1760 Registers (ARRs) which provide a similar functionality to MTRRs. For
1761 these, the ARRs are used to emulate the MTRRs.
1762 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1763 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1764 write-combining. All of these processors are supported by this code
1765 and it makes sense to say Y here if you have one of them.
1766
1767 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1768 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1769 can lead to all sorts of problems, so it's good to say Y here.
1770
1771 You can safely say Y even if your machine doesn't have MTRRs, you'll
1772 just add about 9 KB to your kernel.
1773
7225e751 1774 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1775
95ffa243 1776config MTRR_SANITIZER
2ffb3501 1777 def_bool y
95ffa243
YL
1778 prompt "MTRR cleanup support"
1779 depends on MTRR
8f9ca475 1780 ---help---
aba3728c
TG
1781 Convert MTRR layout from continuous to discrete, so X drivers can
1782 add writeback entries.
95ffa243 1783
aba3728c 1784 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1785 The largest mtrr entry size for a continuous block can be set with
aba3728c 1786 mtrr_chunk_size.
95ffa243 1787
2ffb3501 1788 If unsure, say Y.
95ffa243
YL
1789
1790config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1791 int "MTRR cleanup enable value (0-1)"
1792 range 0 1
1793 default "0"
95ffa243 1794 depends on MTRR_SANITIZER
8f9ca475 1795 ---help---
f5098d62 1796 Enable mtrr cleanup default value
95ffa243 1797
12031a62
YL
1798config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1799 int "MTRR cleanup spare reg num (0-7)"
1800 range 0 7
1801 default "1"
1802 depends on MTRR_SANITIZER
8f9ca475 1803 ---help---
12031a62 1804 mtrr cleanup spare entries default, it can be changed via
aba3728c 1805 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1806
2e5d9c85 1807config X86_PAT
6fc108a0 1808 def_bool y
6a108a14 1809 prompt "x86 PAT support" if EXPERT
2a8a2719 1810 depends on MTRR
8f9ca475 1811 ---help---
2e5d9c85 1812 Use PAT attributes to setup page level cache control.
042b78e4 1813
2e5d9c85 1814 PATs are the modern equivalents of MTRRs and are much more
1815 flexible than MTRRs.
1816
1817 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1818 spontaneous reboots) or a non-working video driver.
2e5d9c85 1819
1820 If unsure, say Y.
1821
46cf98cd
VP
1822config ARCH_USES_PG_UNCACHED
1823 def_bool y
1824 depends on X86_PAT
1825
628c6246
PA
1826config ARCH_RANDOM
1827 def_bool y
1828 prompt "x86 architectural random number generator" if EXPERT
1829 ---help---
1830 Enable the x86 architectural RDRAND instruction
1831 (Intel Bull Mountain technology) to generate random numbers.
1832 If supported, this is a high bandwidth, cryptographically
1833 secure hardware random number generator.
1834
51ae4a2d
PA
1835config X86_SMAP
1836 def_bool y
1837 prompt "Supervisor Mode Access Prevention" if EXPERT
1838 ---help---
1839 Supervisor Mode Access Prevention (SMAP) is a security
1840 feature in newer Intel processors. There is a small
1841 performance cost if this enabled and turned on; there is
1842 also a small increase in the kernel size if this is enabled.
1843
1844 If unsure, say Y.
1845
aa35f896 1846config X86_INTEL_UMIP
796ebc81 1847 def_bool y
aa35f896
RN
1848 depends on CPU_SUP_INTEL
1849 prompt "Intel User Mode Instruction Prevention" if EXPERT
1850 ---help---
1851 The User Mode Instruction Prevention (UMIP) is a security
1852 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1853 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1854 or STR instructions are executed in user mode. These instructions
1855 unnecessarily expose information about the hardware state.
1856
1857 The vast majority of applications do not use these instructions.
1858 For the very few that do, software emulation is provided in
1859 specific cases in protected and virtual-8086 modes. Emulated
1860 results are dummy.
aa35f896 1861
72e9b5fe
DH
1862config X86_INTEL_MPX
1863 prompt "Intel MPX (Memory Protection Extensions)"
1864 def_bool n
df3735c5
RR
1865 # Note: only available in 64-bit mode due to VMA flags shortage
1866 depends on CPU_SUP_INTEL && X86_64
1867 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1868 ---help---
1869 MPX provides hardware features that can be used in
1870 conjunction with compiler-instrumented code to check
1871 memory references. It is designed to detect buffer
1872 overflow or underflow bugs.
1873
1874 This option enables running applications which are
1875 instrumented or otherwise use MPX. It does not use MPX
1876 itself inside the kernel or to protect the kernel
1877 against bad memory references.
1878
1879 Enabling this option will make the kernel larger:
1880 ~8k of kernel text and 36 bytes of data on a 64-bit
1881 defconfig. It adds a long to the 'mm_struct' which
1882 will increase the kernel memory overhead of each
1883 process and adds some branches to paths used during
1884 exec() and munmap().
1885
1886 For details, see Documentation/x86/intel_mpx.txt
1887
1888 If unsure, say N.
1889
35e97790 1890config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1891 prompt "Intel Memory Protection Keys"
35e97790 1892 def_bool y
284244a9 1893 # Note: only available in 64-bit mode
35e97790 1894 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1895 select ARCH_USES_HIGH_VMA_FLAGS
1896 select ARCH_HAS_PKEYS
284244a9
DH
1897 ---help---
1898 Memory Protection Keys provides a mechanism for enforcing
1899 page-based protections, but without requiring modification of the
1900 page tables when an application changes protection domains.
1901
1902 For details, see Documentation/x86/protection-keys.txt
1903
1904 If unsure, say y.
35e97790 1905
506f1d07 1906config EFI
9ba16087 1907 bool "EFI runtime service support"
5b83683f 1908 depends on ACPI
f6ce5002 1909 select UCS2_STRING
022ee6c5 1910 select EFI_RUNTIME_WRAPPERS
506f1d07 1911 ---help---
8f9ca475
IM
1912 This enables the kernel to use EFI runtime services that are
1913 available (such as the EFI variable services).
506f1d07 1914
8f9ca475
IM
1915 This option is only useful on systems that have EFI firmware.
1916 In addition, you should use the latest ELILO loader available
1917 at <http://elilo.sourceforge.net> in order to take advantage
1918 of EFI runtime services. However, even with this option, the
1919 resultant kernel should continue to boot on existing non-EFI
1920 platforms.
506f1d07 1921
291f3632
MF
1922config EFI_STUB
1923 bool "EFI stub support"
b16d8c23 1924 depends on EFI && !X86_USE_3DNOW
7b2a583a 1925 select RELOCATABLE
291f3632
MF
1926 ---help---
1927 This kernel feature allows a bzImage to be loaded directly
1928 by EFI firmware without the use of a bootloader.
1929
4172fe2f 1930 See Documentation/efi-stub.txt for more information.
0c759662 1931
7d453eee
MF
1932config EFI_MIXED
1933 bool "EFI mixed-mode support"
1934 depends on EFI_STUB && X86_64
1935 ---help---
1936 Enabling this feature allows a 64-bit kernel to be booted
1937 on a 32-bit firmware, provided that your CPU supports 64-bit
1938 mode.
1939
1940 Note that it is not possible to boot a mixed-mode enabled
1941 kernel via the EFI boot stub - a bootloader that supports
1942 the EFI handover protocol must be used.
1943
1944 If unsure, say N.
1945
506f1d07 1946config SECCOMP
3c2362e6
HH
1947 def_bool y
1948 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1949 ---help---
506f1d07
SR
1950 This kernel feature is useful for number crunching applications
1951 that may need to compute untrusted bytecode during their
1952 execution. By using pipes or other transports made available to
1953 the process as file descriptors supporting the read/write
1954 syscalls, it's possible to isolate those applications in
1955 their own address space using seccomp. Once seccomp is
9c0bbee8 1956 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1957 and the task is only allowed to execute a few safe syscalls
1958 defined by each seccomp mode.
1959
1960 If unsure, say Y. Only embedded should say N here.
1961
506f1d07
SR
1962source kernel/Kconfig.hz
1963
1964config KEXEC
1965 bool "kexec system call"
2965faa5 1966 select KEXEC_CORE
8f9ca475 1967 ---help---
506f1d07
SR
1968 kexec is a system call that implements the ability to shutdown your
1969 current kernel, and to start another kernel. It is like a reboot
1970 but it is independent of the system firmware. And like a reboot
1971 you can start any kernel with it, not just Linux.
1972
1973 The name comes from the similarity to the exec system call.
1974
1975 It is an ongoing process to be certain the hardware in a machine
1976 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1977 initially work for you. As of this writing the exact hardware
1978 interface is strongly in flux, so no good recommendation can be
1979 made.
506f1d07 1980
74ca317c
VG
1981config KEXEC_FILE
1982 bool "kexec file based system call"
2965faa5 1983 select KEXEC_CORE
74ca317c 1984 select BUILD_BIN2C
74ca317c
VG
1985 depends on X86_64
1986 depends on CRYPTO=y
1987 depends on CRYPTO_SHA256=y
1988 ---help---
1989 This is new version of kexec system call. This system call is
1990 file based and takes file descriptors as system call argument
1991 for kernel and initramfs as opposed to list of segments as
1992 accepted by previous system call.
1993
b799a09f
AT
1994config ARCH_HAS_KEXEC_PURGATORY
1995 def_bool KEXEC_FILE
1996
8e7d8381
VG
1997config KEXEC_VERIFY_SIG
1998 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1999 depends on KEXEC_FILE
8e7d8381
VG
2000 ---help---
2001 This option makes kernel signature verification mandatory for
d8eb8940
BP
2002 the kexec_file_load() syscall.
2003
2004 In addition to that option, you need to enable signature
2005 verification for the corresponding kernel image type being
2006 loaded in order for this to work.
8e7d8381
VG
2007
2008config KEXEC_BZIMAGE_VERIFY_SIG
2009 bool "Enable bzImage signature verification support"
2010 depends on KEXEC_VERIFY_SIG
2011 depends on SIGNED_PE_FILE_VERIFICATION
2012 select SYSTEM_TRUSTED_KEYRING
2013 ---help---
2014 Enable bzImage signature verification support.
2015
506f1d07 2016config CRASH_DUMP
04b69447 2017 bool "kernel crash dumps"
506f1d07 2018 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2019 ---help---
506f1d07
SR
2020 Generate crash dump after being started by kexec.
2021 This should be normally only set in special crash dump kernels
2022 which are loaded in the main kernel with kexec-tools into
2023 a specially reserved region and then later executed after
2024 a crash by kdump/kexec. The crash dump kernel must be compiled
2025 to a memory address not used by the main kernel or BIOS using
2026 PHYSICAL_START, or it must be built as a relocatable image
2027 (CONFIG_RELOCATABLE=y).
2028 For more details see Documentation/kdump/kdump.txt
2029
3ab83521 2030config KEXEC_JUMP
6ea30386 2031 bool "kexec jump"
fee7b0d8 2032 depends on KEXEC && HIBERNATION
8f9ca475 2033 ---help---
89081d17
HY
2034 Jump between original kernel and kexeced kernel and invoke
2035 code in physical address mode via KEXEC
3ab83521 2036
506f1d07 2037config PHYSICAL_START
6a108a14 2038 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2039 default "0x1000000"
8f9ca475 2040 ---help---
506f1d07
SR
2041 This gives the physical address where the kernel is loaded.
2042
2043 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2044 bzImage will decompress itself to above physical address and
2045 run from there. Otherwise, bzImage will run from the address where
2046 it has been loaded by the boot loader and will ignore above physical
2047 address.
2048
2049 In normal kdump cases one does not have to set/change this option
2050 as now bzImage can be compiled as a completely relocatable image
2051 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2052 address. This option is mainly useful for the folks who don't want
2053 to use a bzImage for capturing the crash dump and want to use a
2054 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2055 to be specifically compiled to run from a specific memory area
2056 (normally a reserved region) and this option comes handy.
2057
ceefccc9
PA
2058 So if you are using bzImage for capturing the crash dump,
2059 leave the value here unchanged to 0x1000000 and set
2060 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2061 for capturing the crash dump change this value to start of
2062 the reserved region. In other words, it can be set based on
2063 the "X" value as specified in the "crashkernel=YM@XM"
2064 command line boot parameter passed to the panic-ed
2065 kernel. Please take a look at Documentation/kdump/kdump.txt
2066 for more details about crash dumps.
506f1d07
SR
2067
2068 Usage of bzImage for capturing the crash dump is recommended as
2069 one does not have to build two kernels. Same kernel can be used
2070 as production kernel and capture kernel. Above option should have
2071 gone away after relocatable bzImage support is introduced. But it
2072 is present because there are users out there who continue to use
2073 vmlinux for dump capture. This option should go away down the
2074 line.
2075
2076 Don't change this unless you know what you are doing.
2077
2078config RELOCATABLE
26717808
PA
2079 bool "Build a relocatable kernel"
2080 default y
8f9ca475 2081 ---help---
506f1d07
SR
2082 This builds a kernel image that retains relocation information
2083 so it can be loaded someplace besides the default 1MB.
2084 The relocations tend to make the kernel binary about 10% larger,
2085 but are discarded at runtime.
2086
2087 One use is for the kexec on panic case where the recovery kernel
2088 must live at a different physical address than the primary
2089 kernel.
2090
2091 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2092 it has been loaded at and the compile time physical address
8ab3820f 2093 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2094
8ab3820f 2095config RANDOMIZE_BASE
e8581e3d 2096 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2097 depends on RELOCATABLE
6807c846 2098 default y
8ab3820f 2099 ---help---
e8581e3d
BH
2100 In support of Kernel Address Space Layout Randomization (KASLR),
2101 this randomizes the physical address at which the kernel image
2102 is decompressed and the virtual address where the kernel
2103 image is mapped, as a security feature that deters exploit
2104 attempts relying on knowledge of the location of kernel
2105 code internals.
2106
ed9f007e
KC
2107 On 64-bit, the kernel physical and virtual addresses are
2108 randomized separately. The physical address will be anywhere
2109 between 16MB and the top of physical memory (up to 64TB). The
2110 virtual address will be randomized from 16MB up to 1GB (9 bits
2111 of entropy). Note that this also reduces the memory space
2112 available to kernel modules from 1.5GB to 1GB.
2113
2114 On 32-bit, the kernel physical and virtual addresses are
2115 randomized together. They will be randomized from 16MB up to
2116 512MB (8 bits of entropy).
e8581e3d
BH
2117
2118 Entropy is generated using the RDRAND instruction if it is
2119 supported. If RDTSC is supported, its value is mixed into
2120 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2121 supported, then entropy is read from the i8254 timer. The
2122 usable entropy is limited by the kernel being built using
2123 2GB addressing, and that PHYSICAL_ALIGN must be at a
2124 minimum of 2MB. As a result, only 10 bits of entropy are
2125 theoretically possible, but the implementations are further
2126 limited due to memory layouts.
e8581e3d 2127
6807c846 2128 If unsure, say Y.
8ab3820f
KC
2129
2130# Relocation on x86 needs some additional build support
845adf72
PA
2131config X86_NEED_RELOCS
2132 def_bool y
8ab3820f 2133 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2134
506f1d07 2135config PHYSICAL_ALIGN
a0215061 2136 hex "Alignment value to which kernel should be aligned"
8ab3820f 2137 default "0x200000"
a0215061
KC
2138 range 0x2000 0x1000000 if X86_32
2139 range 0x200000 0x1000000 if X86_64
8f9ca475 2140 ---help---
506f1d07
SR
2141 This value puts the alignment restrictions on physical address
2142 where kernel is loaded and run from. Kernel is compiled for an
2143 address which meets above alignment restriction.
2144
2145 If bootloader loads the kernel at a non-aligned address and
2146 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2147 address aligned to above value and run from there.
2148
2149 If bootloader loads the kernel at a non-aligned address and
2150 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2151 load address and decompress itself to the address it has been
2152 compiled for and run from there. The address for which kernel is
2153 compiled already meets above alignment restrictions. Hence the
2154 end result is that kernel runs from a physical address meeting
2155 above alignment restrictions.
2156
a0215061
KC
2157 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2158 this value must be a multiple of 0x200000.
2159
506f1d07
SR
2160 Don't change this unless you know what you are doing.
2161
eedb92ab
KS
2162config DYNAMIC_MEMORY_LAYOUT
2163 bool
2164 ---help---
2165 This option makes base addresses of vmalloc and vmemmap as well as
2166 __PAGE_OFFSET movable during boot.
2167
0483e1fa
TG
2168config RANDOMIZE_MEMORY
2169 bool "Randomize the kernel memory sections"
2170 depends on X86_64
2171 depends on RANDOMIZE_BASE
eedb92ab 2172 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2173 default RANDOMIZE_BASE
2174 ---help---
2175 Randomizes the base virtual address of kernel memory sections
2176 (physical memory mapping, vmalloc & vmemmap). This security feature
2177 makes exploits relying on predictable memory locations less reliable.
2178
2179 The order of allocations remains unchanged. Entropy is generated in
2180 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2181 configuration have in average 30,000 different possible virtual
2182 addresses for each memory section.
2183
6807c846 2184 If unsure, say Y.
0483e1fa 2185
90397a41
TG
2186config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2187 hex "Physical memory mapping padding" if EXPERT
2188 depends on RANDOMIZE_MEMORY
2189 default "0xa" if MEMORY_HOTPLUG
2190 default "0x0"
2191 range 0x1 0x40 if MEMORY_HOTPLUG
2192 range 0x0 0x40
2193 ---help---
2194 Define the padding in terabytes added to the existing physical
2195 memory size during kernel memory randomization. It is useful
2196 for memory hotplug support but reduces the entropy available for
2197 address randomization.
2198
2199 If unsure, leave at the default value.
2200
506f1d07 2201config HOTPLUG_CPU
7c13e6a3 2202 bool "Support for hot-pluggable CPUs"
40b31360 2203 depends on SMP
506f1d07 2204 ---help---
7c13e6a3
DS
2205 Say Y here to allow turning CPUs off and on. CPUs can be
2206 controlled through /sys/devices/system/cpu.
2207 ( Note: power management support will enable this option
2208 automatically on SMP systems. )
2209 Say N if you want to disable CPU hotplug.
506f1d07 2210
80aa1dff
FY
2211config BOOTPARAM_HOTPLUG_CPU0
2212 bool "Set default setting of cpu0_hotpluggable"
2213 default n
2c922cd0 2214 depends on HOTPLUG_CPU
80aa1dff
FY
2215 ---help---
2216 Set whether default state of cpu0_hotpluggable is on or off.
2217
2218 Say Y here to enable CPU0 hotplug by default. If this switch
2219 is turned on, there is no need to give cpu0_hotplug kernel
2220 parameter and the CPU0 hotplug feature is enabled by default.
2221
2222 Please note: there are two known CPU0 dependencies if you want
2223 to enable the CPU0 hotplug feature either by this switch or by
2224 cpu0_hotplug kernel parameter.
2225
2226 First, resume from hibernate or suspend always starts from CPU0.
2227 So hibernate and suspend are prevented if CPU0 is offline.
2228
2229 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2230 offline if any interrupt can not migrate out of CPU0. There may
2231 be other CPU0 dependencies.
2232
2233 Please make sure the dependencies are under your control before
2234 you enable this feature.
2235
2236 Say N if you don't want to enable CPU0 hotplug feature by default.
2237 You still can enable the CPU0 hotplug feature at boot by kernel
2238 parameter cpu0_hotplug.
2239
a71c8bc5
FY
2240config DEBUG_HOTPLUG_CPU0
2241 def_bool n
2242 prompt "Debug CPU0 hotplug"
2c922cd0 2243 depends on HOTPLUG_CPU
a71c8bc5
FY
2244 ---help---
2245 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2246 soon as possible and boots up userspace with CPU0 offlined. User
2247 can online CPU0 back after boot time.
2248
2249 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2250 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2251 compilation or giving cpu0_hotplug kernel parameter at boot.
2252
2253 If unsure, say N.
2254
506f1d07 2255config COMPAT_VDSO
b0b49f26
AL
2256 def_bool n
2257 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2258 depends on COMPAT_32
8f9ca475 2259 ---help---
b0b49f26
AL
2260 Certain buggy versions of glibc will crash if they are
2261 presented with a 32-bit vDSO that is not mapped at the address
2262 indicated in its segment table.
e84446de 2263
b0b49f26
AL
2264 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2265 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2266 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2267 the only released version with the bug, but OpenSUSE 9
2268 contains a buggy "glibc 2.3.2".
506f1d07 2269
b0b49f26
AL
2270 The symptom of the bug is that everything crashes on startup, saying:
2271 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2272
2273 Saying Y here changes the default value of the vdso32 boot
2274 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2275 This works around the glibc bug but hurts performance.
2276
2277 If unsure, say N: if you are compiling your own kernel, you
2278 are unlikely to be using a buggy version of glibc.
506f1d07 2279
3dc33bd3
KC
2280choice
2281 prompt "vsyscall table for legacy applications"
2282 depends on X86_64
2283 default LEGACY_VSYSCALL_EMULATE
2284 help
2285 Legacy user code that does not know how to find the vDSO expects
2286 to be able to issue three syscalls by calling fixed addresses in
2287 kernel space. Since this location is not randomized with ASLR,
2288 it can be used to assist security vulnerability exploitation.
2289
2290 This setting can be changed at boot time via the kernel command
076ca272 2291 line parameter vsyscall=[emulate|none].
3dc33bd3
KC
2292
2293 On a system with recent enough glibc (2.14 or newer) and no
2294 static binaries, you can say None without a performance penalty
2295 to improve security.
2296
2297 If unsure, select "Emulate".
2298
3dc33bd3
KC
2299 config LEGACY_VSYSCALL_EMULATE
2300 bool "Emulate"
2301 help
2302 The kernel traps and emulates calls into the fixed
2303 vsyscall address mapping. This makes the mapping
2304 non-executable, but it still contains known contents,
2305 which could be used in certain rare security vulnerability
2306 exploits. This configuration is recommended when userspace
2307 still uses the vsyscall area.
2308
2309 config LEGACY_VSYSCALL_NONE
2310 bool "None"
2311 help
2312 There will be no vsyscall mapping at all. This will
2313 eliminate any risk of ASLR bypass due to the vsyscall
2314 fixed address mapping. Attempts to use the vsyscalls
2315 will be reported to dmesg, so that either old or
2316 malicious userspace programs can be identified.
2317
2318endchoice
2319
516cbf37
TB
2320config CMDLINE_BOOL
2321 bool "Built-in kernel command line"
8f9ca475 2322 ---help---
516cbf37
TB
2323 Allow for specifying boot arguments to the kernel at
2324 build time. On some systems (e.g. embedded ones), it is
2325 necessary or convenient to provide some or all of the
2326 kernel boot arguments with the kernel itself (that is,
2327 to not rely on the boot loader to provide them.)
2328
2329 To compile command line arguments into the kernel,
2330 set this option to 'Y', then fill in the
69711ca1 2331 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2332
2333 Systems with fully functional boot loaders (i.e. non-embedded)
2334 should leave this option set to 'N'.
2335
2336config CMDLINE
2337 string "Built-in kernel command string"
2338 depends on CMDLINE_BOOL
2339 default ""
8f9ca475 2340 ---help---
516cbf37
TB
2341 Enter arguments here that should be compiled into the kernel
2342 image and used at boot time. If the boot loader provides a
2343 command line at boot time, it is appended to this string to
2344 form the full kernel command line, when the system boots.
2345
2346 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2347 change this behavior.
2348
2349 In most cases, the command line (whether built-in or provided
2350 by the boot loader) should specify the device for the root
2351 file system.
2352
2353config CMDLINE_OVERRIDE
2354 bool "Built-in command line overrides boot loader arguments"
516cbf37 2355 depends on CMDLINE_BOOL
8f9ca475 2356 ---help---
516cbf37
TB
2357 Set this option to 'Y' to have the kernel ignore the boot loader
2358 command line, and use ONLY the built-in command line.
2359
2360 This is used to work around broken boot loaders. This should
2361 be set to 'N' under normal conditions.
2362
a5b9e5a2
AL
2363config MODIFY_LDT_SYSCALL
2364 bool "Enable the LDT (local descriptor table)" if EXPERT
2365 default y
2366 ---help---
2367 Linux can allow user programs to install a per-process x86
2368 Local Descriptor Table (LDT) using the modify_ldt(2) system
2369 call. This is required to run 16-bit or segmented code such as
2370 DOSEMU or some Wine programs. It is also used by some very old
2371 threading libraries.
2372
2373 Enabling this feature adds a small amount of overhead to
2374 context switches and increases the low-level kernel attack
2375 surface. Disabling it removes the modify_ldt(2) system call.
2376
2377 Saying 'N' here may make sense for embedded or server kernels.
2378
b700e7f0
SJ
2379source "kernel/livepatch/Kconfig"
2380
506f1d07
SR
2381endmenu
2382
3072e413
MH
2383config ARCH_HAS_ADD_PAGES
2384 def_bool y
2385 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2386
506f1d07
SR
2387config ARCH_ENABLE_MEMORY_HOTPLUG
2388 def_bool y
2389 depends on X86_64 || (X86_32 && HIGHMEM)
2390
35551053
GH
2391config ARCH_ENABLE_MEMORY_HOTREMOVE
2392 def_bool y
2393 depends on MEMORY_HOTPLUG
2394
e534c7c5 2395config USE_PERCPU_NUMA_NODE_ID
645a7919 2396 def_bool y
e534c7c5
LS
2397 depends on NUMA
2398
9491846f
KS
2399config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2400 def_bool y
2401 depends on X86_64 || X86_PAE
2402
c177c81e
NH
2403config ARCH_ENABLE_HUGEPAGE_MIGRATION
2404 def_bool y
2405 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2406
9c670ea3
NH
2407config ARCH_ENABLE_THP_MIGRATION
2408 def_bool y
2409 depends on X86_64 && TRANSPARENT_HUGEPAGE
2410
da85f865 2411menu "Power management and ACPI options"
e279b6c1
SR
2412
2413config ARCH_HIBERNATION_HEADER
3c2362e6 2414 def_bool y
e279b6c1 2415 depends on X86_64 && HIBERNATION
e279b6c1
SR
2416
2417source "kernel/power/Kconfig"
2418
2419source "drivers/acpi/Kconfig"
2420
efafc8b2
FT
2421source "drivers/sfi/Kconfig"
2422
a6b68076 2423config X86_APM_BOOT
6fc108a0 2424 def_bool y
282e5aab 2425 depends on APM
a6b68076 2426
e279b6c1
SR
2427menuconfig APM
2428 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2429 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2430 ---help---
2431 APM is a BIOS specification for saving power using several different
2432 techniques. This is mostly useful for battery powered laptops with
2433 APM compliant BIOSes. If you say Y here, the system time will be
2434 reset after a RESUME operation, the /proc/apm device will provide
2435 battery status information, and user-space programs will receive
2436 notification of APM "events" (e.g. battery status change).
2437
2438 If you select "Y" here, you can disable actual use of the APM
2439 BIOS by passing the "apm=off" option to the kernel at boot time.
2440
2441 Note that the APM support is almost completely disabled for
2442 machines with more than one CPU.
2443
2444 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2445 and more information, read <file:Documentation/power/apm-acpi.txt>
2446 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2447 <http://www.tldp.org/docs.html#howto>.
2448
2449 This driver does not spin down disk drives (see the hdparm(8)
2450 manpage ("man 8 hdparm") for that), and it doesn't turn off
2451 VESA-compliant "green" monitors.
2452
2453 This driver does not support the TI 4000M TravelMate and the ACER
2454 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2455 desktop machines also don't have compliant BIOSes, and this driver
2456 may cause those machines to panic during the boot phase.
2457
2458 Generally, if you don't have a battery in your machine, there isn't
2459 much point in using this driver and you should say N. If you get
2460 random kernel OOPSes or reboots that don't seem to be related to
2461 anything, try disabling/enabling this option (or disabling/enabling
2462 APM in your BIOS).
2463
2464 Some other things you should try when experiencing seemingly random,
2465 "weird" problems:
2466
2467 1) make sure that you have enough swap space and that it is
2468 enabled.
2469 2) pass the "no-hlt" option to the kernel
2470 3) switch on floating point emulation in the kernel and pass
2471 the "no387" option to the kernel
2472 4) pass the "floppy=nodma" option to the kernel
2473 5) pass the "mem=4M" option to the kernel (thereby disabling
2474 all but the first 4 MB of RAM)
2475 6) make sure that the CPU is not over clocked.
2476 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2477 8) disable the cache from your BIOS settings
2478 9) install a fan for the video card or exchange video RAM
2479 10) install a better fan for the CPU
2480 11) exchange RAM chips
2481 12) exchange the motherboard.
2482
2483 To compile this driver as a module, choose M here: the
2484 module will be called apm.
2485
2486if APM
2487
2488config APM_IGNORE_USER_SUSPEND
2489 bool "Ignore USER SUSPEND"
8f9ca475 2490 ---help---
e279b6c1
SR
2491 This option will ignore USER SUSPEND requests. On machines with a
2492 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2493 series notebooks, it is necessary to say Y because of a BIOS bug.
2494
2495config APM_DO_ENABLE
2496 bool "Enable PM at boot time"
2497 ---help---
2498 Enable APM features at boot time. From page 36 of the APM BIOS
2499 specification: "When disabled, the APM BIOS does not automatically
2500 power manage devices, enter the Standby State, enter the Suspend
2501 State, or take power saving steps in response to CPU Idle calls."
2502 This driver will make CPU Idle calls when Linux is idle (unless this
2503 feature is turned off -- see "Do CPU IDLE calls", below). This
2504 should always save battery power, but more complicated APM features
2505 will be dependent on your BIOS implementation. You may need to turn
2506 this option off if your computer hangs at boot time when using APM
2507 support, or if it beeps continuously instead of suspending. Turn
2508 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2509 T400CDT. This is off by default since most machines do fine without
2510 this feature.
2511
2512config APM_CPU_IDLE
dd8af076 2513 depends on CPU_IDLE
e279b6c1 2514 bool "Make CPU Idle calls when idle"
8f9ca475 2515 ---help---
e279b6c1
SR
2516 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2517 On some machines, this can activate improved power savings, such as
2518 a slowed CPU clock rate, when the machine is idle. These idle calls
2519 are made after the idle loop has run for some length of time (e.g.,
2520 333 mS). On some machines, this will cause a hang at boot time or
2521 whenever the CPU becomes idle. (On machines with more than one CPU,
2522 this option does nothing.)
2523
2524config APM_DISPLAY_BLANK
2525 bool "Enable console blanking using APM"
8f9ca475 2526 ---help---
e279b6c1
SR
2527 Enable console blanking using the APM. Some laptops can use this to
2528 turn off the LCD backlight when the screen blanker of the Linux
2529 virtual console blanks the screen. Note that this is only used by
2530 the virtual console screen blanker, and won't turn off the backlight
2531 when using the X Window system. This also doesn't have anything to
2532 do with your VESA-compliant power-saving monitor. Further, this
2533 option doesn't work for all laptops -- it might not turn off your
2534 backlight at all, or it might print a lot of errors to the console,
2535 especially if you are using gpm.
2536
2537config APM_ALLOW_INTS
2538 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2539 ---help---
e279b6c1
SR
2540 Normally we disable external interrupts while we are making calls to
2541 the APM BIOS as a measure to lessen the effects of a badly behaving
2542 BIOS implementation. The BIOS should reenable interrupts if it
2543 needs to. Unfortunately, some BIOSes do not -- especially those in
2544 many of the newer IBM Thinkpads. If you experience hangs when you
2545 suspend, try setting this to Y. Otherwise, say N.
2546
e279b6c1
SR
2547endif # APM
2548
bb0a56ec 2549source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2550
2551source "drivers/cpuidle/Kconfig"
2552
27471fdb
AH
2553source "drivers/idle/Kconfig"
2554
e279b6c1
SR
2555endmenu
2556
2557
2558menu "Bus options (PCI etc.)"
2559
2560config PCI
1ac97018 2561 bool "PCI support"
1c858087 2562 default y
8f9ca475 2563 ---help---
e279b6c1
SR
2564 Find out whether you have a PCI motherboard. PCI is the name of a
2565 bus system, i.e. the way the CPU talks to the other stuff inside
2566 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2567 VESA. If you have PCI, say Y, otherwise N.
2568
e279b6c1
SR
2569choice
2570 prompt "PCI access mode"
efefa6f6 2571 depends on X86_32 && PCI
e279b6c1
SR
2572 default PCI_GOANY
2573 ---help---
2574 On PCI systems, the BIOS can be used to detect the PCI devices and
2575 determine their configuration. However, some old PCI motherboards
2576 have BIOS bugs and may crash if this is done. Also, some embedded
2577 PCI-based systems don't have any BIOS at all. Linux can also try to
2578 detect the PCI hardware directly without using the BIOS.
2579
2580 With this option, you can specify how Linux should detect the
2581 PCI devices. If you choose "BIOS", the BIOS will be used,
2582 if you choose "Direct", the BIOS won't be used, and if you
2583 choose "MMConfig", then PCI Express MMCONFIG will be used.
2584 If you choose "Any", the kernel will try MMCONFIG, then the
2585 direct access method and falls back to the BIOS if that doesn't
2586 work. If unsure, go with the default, which is "Any".
2587
2588config PCI_GOBIOS
2589 bool "BIOS"
2590
2591config PCI_GOMMCONFIG
2592 bool "MMConfig"
2593
2594config PCI_GODIRECT
2595 bool "Direct"
2596
3ef0e1f8 2597config PCI_GOOLPC
76fb6570 2598 bool "OLPC XO-1"
3ef0e1f8
AS
2599 depends on OLPC
2600
2bdd1b03
AS
2601config PCI_GOANY
2602 bool "Any"
2603
e279b6c1
SR
2604endchoice
2605
2606config PCI_BIOS
3c2362e6 2607 def_bool y
efefa6f6 2608 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2609
2610# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2611config PCI_DIRECT
3c2362e6 2612 def_bool y
0aba496f 2613 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2614
2615config PCI_MMCONFIG
b45c9f36
JK
2616 bool "Support mmconfig PCI config space access" if X86_64
2617 default y
8364e1f8 2618 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2619 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2620
3ef0e1f8 2621config PCI_OLPC
2bdd1b03
AS
2622 def_bool y
2623 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2624
b5401a96
AN
2625config PCI_XEN
2626 def_bool y
2627 depends on PCI && XEN
2628 select SWIOTLB_XEN
2629
e279b6c1 2630config PCI_DOMAINS
3c2362e6 2631 def_bool y
e279b6c1 2632 depends on PCI
e279b6c1 2633
8364e1f8
JK
2634config MMCONF_FAM10H
2635 def_bool y
2636 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2637
3f6ea84a 2638config PCI_CNB20LE_QUIRK
6a108a14 2639 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2640 depends on PCI
3f6ea84a
IS
2641 help
2642 Read the PCI windows out of the CNB20LE host bridge. This allows
2643 PCI hotplug to work on systems with the CNB20LE chipset which do
2644 not have ACPI.
2645
64a5fed6
BH
2646 There's no public spec for this chipset, and this functionality
2647 is known to be incomplete.
2648
2649 You should say N unless you know you need this.
2650
e279b6c1
SR
2651source "drivers/pci/Kconfig"
2652
3a495511 2653config ISA_BUS
17a2a129 2654 bool "ISA bus support on modern systems" if EXPERT
3a495511 2655 help
17a2a129
WBG
2656 Expose ISA bus device drivers and options available for selection and
2657 configuration. Enable this option if your target machine has an ISA
2658 bus. ISA is an older system, displaced by PCI and newer bus
2659 architectures -- if your target machine is modern, it probably does
2660 not have an ISA bus.
3a495511
WBG
2661
2662 If unsure, say N.
2663
1c00f016 2664# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2665config ISA_DMA_API
1c00f016
DR
2666 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2667 default y
2668 help
2669 Enables ISA-style DMA support for devices requiring such controllers.
2670 If unsure, say Y.
e279b6c1 2671
51e68d05
LT
2672if X86_32
2673
e279b6c1
SR
2674config ISA
2675 bool "ISA support"
8f9ca475 2676 ---help---
e279b6c1
SR
2677 Find out whether you have ISA slots on your motherboard. ISA is the
2678 name of a bus system, i.e. the way the CPU talks to the other stuff
2679 inside your box. Other bus systems are PCI, EISA, MicroChannel
2680 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2681 newer boards don't support it. If you have ISA, say Y, otherwise N.
2682
2683config EISA
2684 bool "EISA support"
2685 depends on ISA
2686 ---help---
2687 The Extended Industry Standard Architecture (EISA) bus was
2688 developed as an open alternative to the IBM MicroChannel bus.
2689
2690 The EISA bus provided some of the features of the IBM MicroChannel
2691 bus while maintaining backward compatibility with cards made for
2692 the older ISA bus. The EISA bus saw limited use between 1988 and
2693 1995 when it was made obsolete by the PCI bus.
2694
2695 Say Y here if you are building a kernel for an EISA-based machine.
2696
2697 Otherwise, say N.
2698
2699source "drivers/eisa/Kconfig"
2700
e279b6c1
SR
2701config SCx200
2702 tristate "NatSemi SCx200 support"
8f9ca475 2703 ---help---
e279b6c1
SR
2704 This provides basic support for National Semiconductor's
2705 (now AMD's) Geode processors. The driver probes for the
2706 PCI-IDs of several on-chip devices, so its a good dependency
2707 for other scx200_* drivers.
2708
2709 If compiled as a module, the driver is named scx200.
2710
2711config SCx200HR_TIMER
2712 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2713 depends on SCx200
e279b6c1 2714 default y
8f9ca475 2715 ---help---
e279b6c1
SR
2716 This driver provides a clocksource built upon the on-chip
2717 27MHz high-resolution timer. Its also a workaround for
2718 NSC Geode SC-1100's buggy TSC, which loses time when the
2719 processor goes idle (as is done by the scheduler). The
2720 other workaround is idle=poll boot option.
2721
3ef0e1f8
AS
2722config OLPC
2723 bool "One Laptop Per Child support"
54008979 2724 depends on !X86_PAE
3c554946 2725 select GPIOLIB
dc3119e7 2726 select OF
45bb1674 2727 select OF_PROMTREE
b4e51854 2728 select IRQ_DOMAIN
8f9ca475 2729 ---help---
3ef0e1f8
AS
2730 Add support for detecting the unique features of the OLPC
2731 XO hardware.
2732
a3128588
DD
2733config OLPC_XO1_PM
2734 bool "OLPC XO-1 Power Management"
97c4cb71 2735 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2736 select MFD_CORE
bf1ebf00 2737 ---help---
97c4cb71 2738 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2739
cfee9597
DD
2740config OLPC_XO1_RTC
2741 bool "OLPC XO-1 Real Time Clock"
2742 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2743 ---help---
2744 Add support for the XO-1 real time clock, which can be used as a
2745 programmable wakeup source.
2746
7feda8e9
DD
2747config OLPC_XO1_SCI
2748 bool "OLPC XO-1 SCI extras"
92e830f2 2749 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2750 depends on INPUT=y
d8d01a63 2751 select POWER_SUPPLY
7feda8e9
DD
2752 ---help---
2753 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2754 - EC-driven system wakeups
7feda8e9 2755 - Power button
7bc74b3d 2756 - Ebook switch
2cf2baea 2757 - Lid switch
e1040ac6
DD
2758 - AC adapter status updates
2759 - Battery status updates
7feda8e9 2760
a0f30f59
DD
2761config OLPC_XO15_SCI
2762 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2763 depends on OLPC && ACPI
2764 select POWER_SUPPLY
a0f30f59
DD
2765 ---help---
2766 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2767 - EC-driven system wakeups
2768 - AC adapter status updates
2769 - Battery status updates
bf1ebf00 2770
d4f3e350
EW
2771config ALIX
2772 bool "PCEngines ALIX System Support (LED setup)"
2773 select GPIOLIB
2774 ---help---
2775 This option enables system support for the PCEngines ALIX.
2776 At present this just sets up LEDs for GPIO control on
2777 ALIX2/3/6 boards. However, other system specific setup should
2778 get added here.
2779
2780 Note: You must still enable the drivers for GPIO and LED support
2781 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2782
2783 Note: You have to set alix.force=1 for boards with Award BIOS.
2784
da4e3302
PP
2785config NET5501
2786 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2787 select GPIOLIB
2788 ---help---
2789 This option enables system support for the Soekris Engineering net5501.
2790
3197059a
PP
2791config GEOS
2792 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2793 select GPIOLIB
2794 depends on DMI
2795 ---help---
2796 This option enables system support for the Traverse Technologies GEOS.
2797
7d029125
VD
2798config TS5500
2799 bool "Technologic Systems TS-5500 platform support"
2800 depends on MELAN
2801 select CHECK_SIGNATURE
2802 select NEW_LEDS
2803 select LEDS_CLASS
2804 ---help---
2805 This option enables system support for the Technologic Systems TS-5500.
2806
bc0120fd
SR
2807endif # X86_32
2808
23ac4ae8 2809config AMD_NB
e279b6c1 2810 def_bool y
0e152cd7 2811 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2812
2813source "drivers/pcmcia/Kconfig"
2814
388b78ad 2815config RAPIDIO
fdf90abc 2816 tristate "RapidIO support"
388b78ad
AB
2817 depends on PCI
2818 default n
2819 help
fdf90abc 2820 If enabled this option will include drivers and the core
388b78ad
AB
2821 infrastructure code to support RapidIO interconnect devices.
2822
2823source "drivers/rapidio/Kconfig"
2824
e3263ab3
DH
2825config X86_SYSFB
2826 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2827 help
2828 Firmwares often provide initial graphics framebuffers so the BIOS,
2829 bootloader or kernel can show basic video-output during boot for
2830 user-guidance and debugging. Historically, x86 used the VESA BIOS
2831 Extensions and EFI-framebuffers for this, which are mostly limited
2832 to x86.
2833 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2834 framebuffers so the new generic system-framebuffer drivers can be
2835 used on x86. If the framebuffer is not compatible with the generic
2836 modes, it is adverticed as fallback platform framebuffer so legacy
2837 drivers like efifb, vesafb and uvesafb can pick it up.
2838 If this option is not selected, all system framebuffers are always
2839 marked as fallback platform framebuffers as usual.
2840
2841 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2842 not be able to pick up generic system framebuffers if this option
2843 is selected. You are highly encouraged to enable simplefb as
2844 replacement if you select this option. simplefb can correctly deal
2845 with generic system framebuffers. But you should still keep vesafb
2846 and others enabled as fallback if a system framebuffer is
2847 incompatible with simplefb.
2848
2849 If unsure, say Y.
2850
e279b6c1
SR
2851endmenu
2852
2853
2854menu "Executable file formats / Emulations"
2855
2856source "fs/Kconfig.binfmt"
2857
2858config IA32_EMULATION
2859 bool "IA32 Emulation"
2860 depends on X86_64
39f88911 2861 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2862 select BINFMT_ELF
a97f52e6 2863 select COMPAT_BINFMT_ELF
39f88911 2864 select COMPAT_OLD_SIGACTION
8f9ca475 2865 ---help---
5fd92e65
L
2866 Include code to run legacy 32-bit programs under a
2867 64-bit kernel. You should likely turn this on, unless you're
2868 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2869
2870config IA32_AOUT
8f9ca475
IM
2871 tristate "IA32 a.out support"
2872 depends on IA32_EMULATION
2873 ---help---
2874 Support old a.out binaries in the 32bit emulation.
e279b6c1 2875
0bf62763 2876config X86_X32
6ea30386 2877 bool "x32 ABI for 64-bit mode"
9b54050b 2878 depends on X86_64
5fd92e65
L
2879 ---help---
2880 Include code to run binaries for the x32 native 32-bit ABI
2881 for 64-bit processors. An x32 process gets access to the
2882 full 64-bit register file and wide data path while leaving
2883 pointers at 32 bits for smaller memory footprint.
2884
2885 You will need a recent binutils (2.22 or later) with
2886 elf32_x86_64 support enabled to compile a kernel with this
2887 option set.
2888
953fee1d
IM
2889config COMPAT_32
2890 def_bool y
2891 depends on IA32_EMULATION || X86_32
2892 select HAVE_UID16
2893 select OLD_SIGSUSPEND3
2894
e279b6c1 2895config COMPAT
3c2362e6 2896 def_bool y
0bf62763 2897 depends on IA32_EMULATION || X86_X32
e279b6c1 2898
3120e25e 2899if COMPAT
e279b6c1 2900config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2901 def_bool y
e279b6c1
SR
2902
2903config SYSVIPC_COMPAT
3c2362e6 2904 def_bool y
3120e25e 2905 depends on SYSVIPC
3120e25e 2906endif
ee009e4a 2907
e279b6c1
SR
2908endmenu
2909
2910
e5beae16
KP
2911config HAVE_ATOMIC_IOMAP
2912 def_bool y
2913 depends on X86_32
2914
4692d77f
AR
2915config X86_DEV_DMA_OPS
2916 bool
83125a3a 2917 depends on X86_64 || STA2X11
4692d77f 2918
f7219a53
AR
2919config X86_DMA_REMAP
2920 bool
83125a3a 2921 depends on STA2X11
f7219a53 2922
e585513b
KS
2923config HAVE_GENERIC_GUP
2924 def_bool y
2925
e279b6c1
SR
2926source "net/Kconfig"
2927
2928source "drivers/Kconfig"
2929
2930source "drivers/firmware/Kconfig"
2931
2932source "fs/Kconfig"
2933
e279b6c1
SR
2934source "arch/x86/Kconfig.debug"
2935
2936source "security/Kconfig"
2937
2938source "crypto/Kconfig"
2939
edf88417
AK
2940source "arch/x86/kvm/Kconfig"
2941
e279b6c1 2942source "lib/Kconfig"