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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
117ed454 17 select HAVE_DEBUG_STACKOVERFLOW
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18 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
7ac87074 20 select GENERIC_VDSO_32
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21
22config X86_64
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23 def_bool y
24 depends on 64BIT
d94e0685 25 # Options that are inherently 64-bit kernel only:
4eb0716e 26 select ARCH_HAS_GIGANTIC_PAGE
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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
f8781c4a 33 select ARCH_HAS_SYSCALL_WRAPPER
1032c0ba 34
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SRV
35config FORCE_DYNAMIC_FTRACE
36 def_bool y
37 depends on X86_32
38 depends on FUNCTION_TRACER
39 select DYNAMIC_FTRACE
40 help
41 We keep the static function tracing (!DYNAMIC_FTRACE) around
42 in order to test the non static function tracing in the
43 generic code, as other architectures still use it. But we
44 only need to keep it around for x86_64. No need to keep it
45 for x86_32. For x86_32, force DYNAMIC_FTRACE.
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IM
46#
47# Arch settings
48#
49# ( Note that options that are marked 'if X86_64' could in principle be
50# ported to 32-bit as well. )
51#
8d5fffb9 52config X86
3c2362e6 53 def_bool y
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54 #
55 # Note: keep this list sorted alphabetically
56 #
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57 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 59 select ARCH_32BIT_OFF_T if X86_32
6471b825 60 select ARCH_CLOCKSOURCE_DATA
2a21ad57 61 select ARCH_CLOCKSOURCE_INIT
c763ea26 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 63 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 64 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 65 select ARCH_HAS_ELF_RANDOMIZE
72d93104 66 select ARCH_HAS_FAST_MULTIPLIER
316d097c 67 select ARCH_HAS_FILTER_PGPROT
6974f0c4 68 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 69 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 70 select ARCH_HAS_KCOV if X86_64
10bcc80e 71 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 72 select ARCH_HAS_PMEM_API if X86_64
17596731 73 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 74 select ARCH_HAS_PTE_SPECIAL
39208aa7 75 select ARCH_HAS_REFCOUNT
0aed55af 76 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
092b31aa 77 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
d2852a22 78 select ARCH_HAS_SET_MEMORY
d253ca0c 79 select ARCH_HAS_SET_DIRECT_MAP
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LA
80 select ARCH_HAS_STRICT_KERNEL_RWX
81 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 82 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
c6d30853 83 select ARCH_HAS_UBSAN_SANITIZE_ALL
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IM
84 select ARCH_HAVE_NMI_SAFE_CMPXCHG
85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 86 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 87 select ARCH_MIGHT_HAVE_PC_SERIO
3599fe12 88 select ARCH_STACKWALK
2c870e61 89 select ARCH_SUPPORTS_ACPI
6471b825 90 select ARCH_SUPPORTS_ATOMIC_RMW
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91 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
92 select ARCH_USE_BUILTIN_BSWAP
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93 select ARCH_USE_QUEUED_RWLOCKS
94 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 95 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 96 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
3876d4a3 97 select ARCH_WANT_HUGE_PMD_SHARE
38d8b4e6 98 select ARCH_WANTS_THP_SWAP if X86_64
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99 select BUILDTIME_EXTABLE_SORT
100 select CLKEVT_I8253
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101 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
102 select CLOCKSOURCE_WATCHDOG
6471b825 103 select DCACHE_WORD_ACCESS
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LT
104 select EDAC_ATOMIC_SCRUB
105 select EDAC_SUPPORT
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IM
106 select GENERIC_CLOCKEVENTS
107 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
108 select GENERIC_CLOCKEVENTS_MIN_ADJUST
109 select GENERIC_CMOS_UPDATE
110 select GENERIC_CPU_AUTOPROBE
61dc0f55 111 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 112 select GENERIC_EARLY_IOREMAP
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IM
113 select GENERIC_FIND_FIRST_BIT
114 select GENERIC_IOMAP
c7d6c9dd 115 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 116 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 117 select GENERIC_IRQ_MIGRATION if SMP
6471b825 118 select GENERIC_IRQ_PROBE
c201c917 119 select GENERIC_IRQ_RESERVATION_MODE
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IM
120 select GENERIC_IRQ_SHOW
121 select GENERIC_PENDING_IRQ if SMP
122 select GENERIC_SMP_IDLE_THREAD
123 select GENERIC_STRNCPY_FROM_USER
124 select GENERIC_STRNLEN_USER
125 select GENERIC_TIME_VSYSCALL
7ac87074 126 select GENERIC_GETTIMEOFDAY
39656e83 127 select GUP_GET_PTE_LOW_HIGH if X86_PAE
7edaeb68 128 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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129 select HAVE_ACPI_APEI if ACPI
130 select HAVE_ACPI_APEI_NMI if ACPI
131 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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132 select HAVE_ARCH_AUDITSYSCALL
133 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
134 select HAVE_ARCH_JUMP_LABEL
b34006c4 135 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 136 select HAVE_ARCH_KASAN if X86_64
6471b825 137 select HAVE_ARCH_KGDB
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DC
138 select HAVE_ARCH_MMAP_RND_BITS if MMU
139 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 140 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 141 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 142 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 143 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 144 select HAVE_ARCH_STACKLEAK
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145 select HAVE_ARCH_TRACEHOOK
146 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 148 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 149 select HAVE_ARCH_WITHIN_STACK_FRAMES
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150 select HAVE_CMPXCHG_DOUBLE
151 select HAVE_CMPXCHG_LOCAL
152 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 153 select HAVE_COPY_THREAD_TLS
cf4db259 154 select HAVE_C_RECORDMCOUNT
6471b825 155 select HAVE_DEBUG_KMEMLEAK
6471b825 156 select HAVE_DMA_CONTIGUOUS
677aa9f7 157 select HAVE_DYNAMIC_FTRACE
06aeaaea 158 select HAVE_DYNAMIC_FTRACE_WITH_REGS
03f5781b 159 select HAVE_EBPF_JIT
58340a07 160 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 161 select HAVE_EISA
5f56a5df 162 select HAVE_EXIT_THREAD
67a929e0 163 select HAVE_FAST_GUP
644e0e8d 164 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 165 select HAVE_FTRACE_MCOUNT_RECORD
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166 select HAVE_FUNCTION_GRAPH_TRACER
167 select HAVE_FUNCTION_TRACER
6b90bd4b 168 select HAVE_GCC_PLUGINS
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169 select HAVE_HW_BREAKPOINT
170 select HAVE_IDE
171 select HAVE_IOREMAP_PROT
172 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
173 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 174 select HAVE_KERNEL_BZIP2
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175 select HAVE_KERNEL_GZIP
176 select HAVE_KERNEL_LZ4
2e9f3bdd 177 select HAVE_KERNEL_LZMA
13510997 178 select HAVE_KERNEL_LZO
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179 select HAVE_KERNEL_XZ
180 select HAVE_KPROBES
181 select HAVE_KPROBES_ON_FTRACE
540adea3 182 select HAVE_FUNCTION_ERROR_INJECTION
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183 select HAVE_KRETPROBES
184 select HAVE_KVM
185 select HAVE_LIVEPATCH if X86_64
6471b825 186 select HAVE_MEMBLOCK_NODE_MAP
0102752e 187 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 188 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 189 select HAVE_MOVE_PMD
42a0bb3f 190 select HAVE_NMI
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191 select HAVE_OPROFILE
192 select HAVE_OPTPROBES
193 select HAVE_PCSPKR_PLATFORM
194 select HAVE_PERF_EVENTS
c01d4323 195 select HAVE_PERF_EVENTS_NMI
92e5aae4 196 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 197 select HAVE_PCI
c5e63197 198 select HAVE_PERF_REGS
c5ebcedb 199 select HAVE_PERF_USER_STACK_DUMP
48a8b97c 200 select HAVE_RCU_TABLE_FREE if PARAVIRT
6471b825 201 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 202 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 203 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 204 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 205 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 206 select HAVE_RSEQ
6471b825 207 select HAVE_SYSCALL_TRACEPOINTS
6471b825 208 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 209 select HAVE_USER_RETURN_NOTIFIER
7ac87074 210 select HAVE_GENERIC_VDSO
05736e4a 211 select HOTPLUG_SMT if SMP
c0185808 212 select IRQ_FORCED_THREADING
86596f0a 213 select NEED_SG_DMA_LENGTH
2eac9c2d 214 select PCI_DOMAINS if PCI
625210cf 215 select PCI_LOCKLESS_CONFIG if PCI
6471b825 216 select PERF_EVENTS
3195ef59 217 select RTC_LIB
d6faca40 218 select RTC_MC146818_LIB
6471b825 219 select SPARSE_IRQ
83fe27ea 220 select SRCU
6471b825 221 select SYSCTL_EXCEPTION_TRACE
15f4eae7 222 select THREAD_INFO_IN_TASK
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223 select USER_STACKTRACE_SUPPORT
224 select VIRT_TO_BUS
6471b825 225 select X86_FEATURE_NAMES if PROC_FS
0c608dad 226 select PROC_PID_ARCH_STATUS if PROC_FS
7d8330a5 227
ba7e4d13 228config INSTRUCTION_DECODER
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229 def_bool y
230 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 231
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232config OUTPUT_FORMAT
233 string
234 default "elf32-i386" if X86_32
235 default "elf64-x86-64" if X86_64
236
73531905 237config ARCH_DEFCONFIG
b9b39bfb 238 string
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SR
239 default "arch/x86/configs/i386_defconfig" if X86_32
240 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 241
8d5fffb9 242config LOCKDEP_SUPPORT
3c2362e6 243 def_bool y
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SR
244
245config STACKTRACE_SUPPORT
3c2362e6 246 def_bool y
8d5fffb9 247
8d5fffb9 248config MMU
3c2362e6 249 def_bool y
8d5fffb9 250
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DC
251config ARCH_MMAP_RND_BITS_MIN
252 default 28 if 64BIT
253 default 8
254
255config ARCH_MMAP_RND_BITS_MAX
256 default 32 if 64BIT
257 default 16
258
259config ARCH_MMAP_RND_COMPAT_BITS_MIN
260 default 8
261
262config ARCH_MMAP_RND_COMPAT_BITS_MAX
263 default 16
264
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SR
265config SBUS
266 bool
267
268config GENERIC_ISA_DMA
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269 def_bool y
270 depends on ISA_DMA_API
8d5fffb9 271
8d5fffb9 272config GENERIC_BUG
3c2362e6 273 def_bool y
8d5fffb9 274 depends on BUG
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JB
275 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
276
277config GENERIC_BUG_RELATIVE_POINTERS
278 bool
8d5fffb9 279
8d5fffb9 280config ARCH_MAY_HAVE_PC_FDC
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281 def_bool y
282 depends on ISA_DMA_API
8d5fffb9 283
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284config GENERIC_CALIBRATE_DELAY
285 def_bool y
286
9a0b8415 287config ARCH_HAS_CPU_RELAX
288 def_bool y
289
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PE
290config ARCH_HAS_CACHE_LINE_SIZE
291 def_bool y
292
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293config ARCH_HAS_FILTER_PGPROT
294 def_bool y
295
dd5af90a 296config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 297 def_bool y
b32ef636 298
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299config NEED_PER_CPU_EMBED_FIRST_CHUNK
300 def_bool y
301
302config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
303 def_bool y
304
801e4062
JB
305config ARCH_HIBERNATION_POSSIBLE
306 def_bool y
801e4062 307
f4cb5700
JB
308config ARCH_SUSPEND_POSSIBLE
309 def_bool y
f4cb5700 310
53313b2c
SC
311config ARCH_WANT_GENERAL_HUGETLB
312 def_bool y
313
8d5fffb9 314config ZONE_DMA32
e0fd24a3 315 def_bool y if X86_64
8d5fffb9 316
8d5fffb9 317config AUDIT_ARCH
e0fd24a3 318 def_bool y if X86_64
8d5fffb9 319
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AM
320config ARCH_SUPPORTS_DEBUG_PAGEALLOC
321 def_bool y
322
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323config KASAN_SHADOW_OFFSET
324 hex
325 depends on KASAN
326 default 0xdffffc0000000000
327
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328config HAVE_INTEL_TXT
329 def_bool y
6ea30386 330 depends on INTEL_IOMMU && ACPI
69575d38 331
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SR
332config X86_32_SMP
333 def_bool y
334 depends on X86_32 && SMP
335
336config X86_64_SMP
337 def_bool y
338 depends on X86_64 && SMP
339
ccbeed3a
TH
340config X86_32_LAZY_GS
341 def_bool y
8458f8c2 342 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 343
2b144498
SD
344config ARCH_SUPPORTS_UPROBES
345 def_bool y
346
d20642f0
RH
347config FIX_EARLYCON_MEM
348 def_bool y
349
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KS
350config DYNAMIC_PHYSICAL_MASK
351 bool
352
98233368
KS
353config PGTABLE_LEVELS
354 int
77ef56e4 355 default 5 if X86_5LEVEL
98233368
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356 default 4 if X86_64
357 default 3 if X86_PAE
358 default 2
359
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MY
360config CC_HAS_SANE_STACKPROTECTOR
361 bool
362 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
363 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
364 help
365 We have to make sure stack protector is unconditionally disabled if
366 the compiler produces broken code.
367
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SR
368menu "Processor type and features"
369
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RD
370config ZONE_DMA
371 bool "DMA memory allocation support" if EXPERT
372 default y
373 help
374 DMA memory allocation support allows devices with less than 32-bit
375 addressing to allocate within the first 16MB of address space.
376 Disable if no such devices will be used.
377
378 If unsure, say Y.
379
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SR
380config SMP
381 bool "Symmetric multi-processing support"
382 ---help---
383 This enables support for systems with more than one CPU. If you have
4a474157
RG
384 a system with only one CPU, say N. If you have a system with more
385 than one CPU, say Y.
506f1d07 386
4a474157 387 If you say N here, the kernel will run on uni- and multiprocessor
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SR
388 machines, but will use only one CPU of a multiprocessor machine. If
389 you say Y here, the kernel will run on many, but not all,
4a474157 390 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
391 will run faster if you say N here.
392
393 Note that if you say Y here and choose architecture "586" or
394 "Pentium" under "Processor family", the kernel will not work on 486
395 architectures. Similarly, multiprocessor kernels for the "PPro"
396 architecture may not work on all Pentium based boards.
397
398 People using multiprocessor machines who say Y here should also say
399 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
400 Management" code will be disabled if you say Y here.
401
cb1aaebe 402 See also <file:Documentation/x86/i386/IO-APIC.rst>,
4f4cfa6c 403 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
506f1d07
SR
404 <http://www.tldp.org/docs.html#howto>.
405
406 If you don't know what to do here, say N.
407
9def39be
JT
408config X86_FEATURE_NAMES
409 bool "Processor feature human-readable names" if EMBEDDED
410 default y
411 ---help---
412 This option compiles in a table of x86 feature bits and corresponding
413 names. This is required to support /proc/cpuinfo and a few kernel
414 messages. You can disable this to save space, at the expense of
415 making those few kernel messages show numeric feature bits instead.
416
417 If in doubt, say Y.
418
06cd9a7d
YL
419config X86_X2APIC
420 bool "Support x2apic"
19e3d60d 421 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
422 ---help---
423 This enables x2apic support on CPUs that have this feature.
424
425 This allows 32-bit apic IDs (so it can support very large systems),
426 and accesses the local apic via MSRs not via mmio.
427
06cd9a7d
YL
428 If you don't know what to do here, say N.
429
6695c85b 430config X86_MPPARSE
6e87f9b7 431 bool "Enable MPS table" if ACPI || SFI
7a527688 432 default y
5ab74722 433 depends on X86_LOCAL_APIC
8f9ca475 434 ---help---
6695c85b
YL
435 For old smp systems that do not have proper acpi support. Newer systems
436 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 437
ddd70cf9
JN
438config GOLDFISH
439 def_bool y
440 depends on X86_GOLDFISH
441
76b04384
DW
442config RETPOLINE
443 bool "Avoid speculative indirect branches in kernel"
444 default y
d5028ba8 445 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
446 help
447 Compile kernel with the retpoline compiler options to guard against
448 kernel-to-user data leaks by avoiding speculative indirect
449 branches. Requires a compiler with -mindirect-branch=thunk-extern
450 support for full protection. The kernel may run slower.
451
e6d42931
JW
452config X86_CPU_RESCTRL
453 bool "x86 CPU resource control support"
6fe07ce3 454 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 455 select KERNFS
78e99b4a 456 help
e6d42931 457 Enable x86 CPU resource control support.
6fe07ce3
BM
458
459 Provide support for the allocation and monitoring of system resources
460 usage by the CPU.
461
462 Intel calls this Intel Resource Director Technology
463 (Intel(R) RDT). More information about RDT can be found in the
464 Intel x86 Architecture Software Developer Manual.
465
466 AMD calls this AMD Platform Quality of Service (AMD QoS).
467 More information about AMD QoS can be found in the AMD64 Technology
468 Platform Quality of Service Extensions manual.
78e99b4a
FY
469
470 Say N if unsure.
471
8425091f 472if X86_32
a0d0bb4d
RD
473config X86_BIGSMP
474 bool "Support for big SMP systems with more than 8 CPUs"
475 depends on SMP
476 ---help---
477 This option is needed for the systems that have more than 8 CPUs
478
c5c606d9
RT
479config X86_EXTENDED_PLATFORM
480 bool "Support for extended (non-PC) x86 platforms"
481 default y
8f9ca475 482 ---help---
06ac8346
IM
483 If you disable this option then the kernel will only support
484 standard PC platforms. (which covers the vast majority of
485 systems out there.)
486
8425091f
RT
487 If you enable this option then you'll be able to select support
488 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 489 Goldfish (Android emulator)
8425091f 490 AMD Elan
8425091f
RT
491 RDC R-321x SoC
492 SGI 320/540 (Visual Workstation)
83125a3a 493 STA2X11-based (e.g. Northville)
3f4110a4 494 Moorestown MID devices
06ac8346
IM
495
496 If you have one of these systems, or if you want to build a
497 generic distribution kernel, say Y here - otherwise say N.
8425091f 498endif
06ac8346 499
8425091f
RT
500if X86_64
501config X86_EXTENDED_PLATFORM
502 bool "Support for extended (non-PC) x86 platforms"
503 default y
504 ---help---
505 If you disable this option then the kernel will only support
506 standard PC platforms. (which covers the vast majority of
507 systems out there.)
508
509 If you enable this option then you'll be able to select support
510 for the following (non-PC) 64 bit x86 platforms:
44b111b5 511 Numascale NumaChip
8425091f
RT
512 ScaleMP vSMP
513 SGI Ultraviolet
514
515 If you have one of these systems, or if you want to build a
516 generic distribution kernel, say Y here - otherwise say N.
517endif
c5c606d9
RT
518# This is an alphabetically sorted list of 64 bit extended platforms
519# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
520config X86_NUMACHIP
521 bool "Numascale NumaChip"
522 depends on X86_64
523 depends on X86_EXTENDED_PLATFORM
524 depends on NUMA
525 depends on SMP
526 depends on X86_X2APIC
f9726bfd 527 depends on PCI_MMCONFIG
44b111b5
SP
528 ---help---
529 Adds support for Numascale NumaChip large-SMP systems. Needed to
530 enable more than ~168 cores.
531 If you don't have one of these, you should say N here.
506f1d07 532
c5c606d9
RT
533config X86_VSMP
534 bool "ScaleMP vSMP"
6276a074 535 select HYPERVISOR_GUEST
c5c606d9
RT
536 select PARAVIRT
537 depends on X86_64 && PCI
538 depends on X86_EXTENDED_PLATFORM
ead91d4b 539 depends on SMP
8f9ca475 540 ---help---
c5c606d9
RT
541 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
542 supposed to run on these EM64T-based machines. Only choose this option
543 if you have one of these machines.
5e3a77e9 544
03b48632
NP
545config X86_UV
546 bool "SGI Ultraviolet"
547 depends on X86_64
c5c606d9 548 depends on X86_EXTENDED_PLATFORM
54c28d29 549 depends on NUMA
1ecb4ae5 550 depends on EFI
9d6c26e7 551 depends on X86_X2APIC
1222e564 552 depends on PCI
8f9ca475 553 ---help---
03b48632
NP
554 This option is needed in order to support SGI Ultraviolet systems.
555 If you don't have one of these, you should say N here.
556
c5c606d9
RT
557# Following is an alphabetically sorted list of 32 bit extended platforms
558# Please maintain the alphabetic order if and when there are additions
506f1d07 559
ddd70cf9
JN
560config X86_GOLDFISH
561 bool "Goldfish (Virtual Platform)"
cb7b8023 562 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
563 ---help---
564 Enable support for the Goldfish virtual platform used primarily
565 for Android development. Unless you are building for the Android
566 Goldfish emulator say N here.
567
c751e17b
TG
568config X86_INTEL_CE
569 bool "CE4100 TV platform"
570 depends on PCI
571 depends on PCI_GODIRECT
6084a6e2 572 depends on X86_IO_APIC
c751e17b
TG
573 depends on X86_32
574 depends on X86_EXTENDED_PLATFORM
37bc9f50 575 select X86_REBOOTFIXUPS
da6b737b
SAS
576 select OF
577 select OF_EARLY_FLATTREE
c751e17b
TG
578 ---help---
579 Select for the Intel CE media processor (CE4100) SOC.
580 This option compiles in support for the CE4100 SOC for settop
581 boxes and media devices.
582
4cb9b00f 583config X86_INTEL_MID
43605ef1 584 bool "Intel MID platform support"
43605ef1 585 depends on X86_EXTENDED_PLATFORM
edc6bc78 586 depends on X86_PLATFORM_DEVICES
1ea7c673 587 depends on PCI
3fda5bb4 588 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 589 depends on X86_IO_APIC
7c9c3a1e 590 select SFI
4cb9b00f 591 select I2C
7c9c3a1e 592 select DW_APB_TIMER
1ea7c673 593 select APB_TIMER
1ea7c673 594 select INTEL_SCU_IPC
15a713df 595 select MFD_INTEL_MSIC
1ea7c673 596 ---help---
4cb9b00f
DC
597 Select to build a kernel capable of supporting Intel MID (Mobile
598 Internet Device) platform systems which do not have the PCI legacy
599 interfaces. If you are building for a PC class system say N here.
1ea7c673 600
4cb9b00f
DC
601 Intel MID platforms are based on an Intel processor and chipset which
602 consume less power than most of the x86 derivatives.
43605ef1 603
8bbc2a13
BD
604config X86_INTEL_QUARK
605 bool "Intel Quark platform support"
606 depends on X86_32
607 depends on X86_EXTENDED_PLATFORM
608 depends on X86_PLATFORM_DEVICES
609 depends on X86_TSC
610 depends on PCI
611 depends on PCI_GOANY
612 depends on X86_IO_APIC
613 select IOSF_MBI
614 select INTEL_IMR
9ab6eb51 615 select COMMON_CLK
8bbc2a13
BD
616 ---help---
617 Select to include support for Quark X1000 SoC.
618 Say Y here if you have a Quark based system such as the Arduino
619 compatible Intel Galileo.
620
3d48aab1
MW
621config X86_INTEL_LPSS
622 bool "Intel Low Power Subsystem Support"
5962dd22 623 depends on X86 && ACPI && PCI
3d48aab1 624 select COMMON_CLK
0f531431 625 select PINCTRL
eebb3e8d 626 select IOSF_MBI
3d48aab1
MW
627 ---help---
628 Select to build support for Intel Low Power Subsystem such as
629 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
630 things like clock tree (common clock framework) and pincontrol
631 which are needed by the LPSS peripheral drivers.
3d48aab1 632
92082a88
KX
633config X86_AMD_PLATFORM_DEVICE
634 bool "AMD ACPI2Platform devices support"
635 depends on ACPI
636 select COMMON_CLK
637 select PINCTRL
638 ---help---
639 Select to interpret AMD specific ACPI device to platform device
640 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
641 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
642 implemented under PINCTRL subsystem.
643
ced3ce76
DB
644config IOSF_MBI
645 tristate "Intel SoC IOSF Sideband support for SoC platforms"
646 depends on PCI
647 ---help---
648 This option enables sideband register access support for Intel SoC
649 platforms. On these platforms the IOSF sideband is used in lieu of
650 MSR's for some register accesses, mostly but not limited to thermal
651 and power. Drivers may query the availability of this device to
652 determine if they need the sideband in order to work on these
653 platforms. The sideband is available on the following SoC products.
654 This list is not meant to be exclusive.
655 - BayTrail
656 - Braswell
657 - Quark
658
659 You should say Y if you are running a kernel on one of these SoC's.
660
ed2226bd
DB
661config IOSF_MBI_DEBUG
662 bool "Enable IOSF sideband access through debugfs"
663 depends on IOSF_MBI && DEBUG_FS
664 ---help---
665 Select this option to expose the IOSF sideband access registers (MCR,
666 MDR, MCRX) through debugfs to write and read register information from
667 different units on the SoC. This is most useful for obtaining device
668 state information for debug and analysis. As this is a general access
669 mechanism, users of this option would have specific knowledge of the
670 device they want to access.
671
672 If you don't require the option or are in doubt, say N.
673
c5c606d9
RT
674config X86_RDC321X
675 bool "RDC R-321x SoC"
506f1d07 676 depends on X86_32
c5c606d9
RT
677 depends on X86_EXTENDED_PLATFORM
678 select M486
679 select X86_REBOOTFIXUPS
680 ---help---
681 This option is needed for RDC R-321x system-on-chip, also known
682 as R-8610-(G).
683 If you don't have one of these chips, you should say N here.
684
e0c7ae37 685config X86_32_NON_STANDARD
9c398017
IM
686 bool "Support non-standard 32-bit SMP architectures"
687 depends on X86_32 && SMP
c5c606d9 688 depends on X86_EXTENDED_PLATFORM
8f9ca475 689 ---help---
b5660ba7
PA
690 This option compiles in the bigsmp and STA2X11 default
691 subarchitectures. It is intended for a generic binary
692 kernel. If you select them all, kernel will probe it one by
693 one and will fallback to default.
d49c4288 694
c5c606d9 695# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 696
d949f36f 697config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 698 def_bool y
d949f36f
LT
699 # MCE code calls memory_failure():
700 depends on X86_MCE
701 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
702 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
703 depends on X86_64 || !SPARSEMEM
704 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 705
83125a3a
AR
706config STA2X11
707 bool "STA2X11 Companion Chip Support"
708 depends on X86_32_NON_STANDARD && PCI
b6e05477 709 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
710 select SWIOTLB
711 select MFD_STA2X11
0145071b 712 select GPIOLIB
83125a3a
AR
713 ---help---
714 This adds support for boards based on the STA2X11 IO-Hub,
715 a.k.a. "ConneXt". The chip is used in place of the standard
716 PC chipset, so all "standard" peripherals are missing. If this
717 option is selected the kernel will still be able to boot on
718 standard PC machines.
719
82148d1d
S
720config X86_32_IRIS
721 tristate "Eurobraille/Iris poweroff module"
722 depends on X86_32
723 ---help---
724 The Iris machines from EuroBraille do not have APM or ACPI support
725 to shut themselves down properly. A special I/O sequence is
726 needed to do so, which is what this module does at
727 kernel shutdown.
728
729 This is only for Iris machines from EuroBraille.
730
731 If unused, say N.
732
ae1e9130 733config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
734 def_bool y
735 prompt "Single-depth WCHAN output"
a87d0914 736 depends on X86
8f9ca475 737 ---help---
506f1d07
SR
738 Calculate simpler /proc/<PID>/wchan values. If this option
739 is disabled then wchan values will recurse back to the
740 caller function. This provides more accurate wchan values,
741 at the expense of slightly more scheduling overhead.
742
743 If in doubt, say "Y".
744
6276a074
BP
745menuconfig HYPERVISOR_GUEST
746 bool "Linux guest support"
8f9ca475 747 ---help---
6276a074
BP
748 Say Y here to enable options for running Linux under various hyper-
749 visors. This option enables basic hypervisor detection and platform
750 setup.
506f1d07 751
6276a074
BP
752 If you say N, all options in this submenu will be skipped and
753 disabled, and Linux guest support won't be built in.
506f1d07 754
6276a074 755if HYPERVISOR_GUEST
506f1d07 756
e61bd94a
EPH
757config PARAVIRT
758 bool "Enable paravirtualization code"
8f9ca475 759 ---help---
e61bd94a
EPH
760 This changes the kernel so it can modify itself when it is run
761 under a hypervisor, potentially improving performance significantly
762 over full virtualization. However, when run without a hypervisor
763 the kernel is theoretically slower and slightly larger.
764
c00a280a
JG
765config PARAVIRT_XXL
766 bool
767
6276a074
BP
768config PARAVIRT_DEBUG
769 bool "paravirt-ops debugging"
770 depends on PARAVIRT && DEBUG_KERNEL
771 ---help---
772 Enable to debug paravirt_ops internals. Specifically, BUG if
773 a paravirt_op is missing when it is called.
774
b4ecc126
JF
775config PARAVIRT_SPINLOCKS
776 bool "Paravirtualization layer for spinlocks"
6ea30386 777 depends on PARAVIRT && SMP
b4ecc126
JF
778 ---help---
779 Paravirtualized spinlocks allow a pvops backend to replace the
780 spinlock implementation with something virtualization-friendly
781 (for example, block the virtual CPU rather than spinning).
782
4c4e4f61
R
783 It has a minimal impact on native kernels and gives a nice performance
784 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 785
4c4e4f61 786 If you are unsure how to answer this question, answer Y.
b4ecc126 787
ecca2502
ZY
788config X86_HV_CALLBACK_VECTOR
789 def_bool n
790
6276a074 791source "arch/x86/xen/Kconfig"
7af192c9 792
6276a074
BP
793config KVM_GUEST
794 bool "KVM Guest support (including kvmclock)"
795 depends on PARAVIRT
796 select PARAVIRT_CLOCK
797 default y
8f9ca475 798 ---help---
6276a074
BP
799 This option enables various optimizations for running under the KVM
800 hypervisor. It includes a paravirtualized clock, so that instead
801 of relying on a PIT (or probably other) emulation by the
802 underlying device model, the host provides the guest with
803 timing infrastructure such as time of day, and system time
506f1d07 804
7733607f
MW
805config PVH
806 bool "Support for running PVH guests"
807 ---help---
808 This option enables the PVH entry point for guest virtual machines
809 as specified in the x86/HVM direct boot ABI.
810
1e20eb85
SV
811config KVM_DEBUG_FS
812 bool "Enable debug information for KVM Guests in debugfs"
813 depends on KVM_GUEST && DEBUG_FS
1e20eb85
SV
814 ---help---
815 This option enables collection of various statistics for KVM guest.
816 Statistics are displayed in debugfs filesystem. Enabling this option
817 may incur significant overhead.
818
6276a074
BP
819config PARAVIRT_TIME_ACCOUNTING
820 bool "Paravirtual steal time accounting"
821 depends on PARAVIRT
8f9ca475 822 ---help---
6276a074
BP
823 Select this option to enable fine granularity task steal time
824 accounting. Time spent executing other tasks in parallel with
825 the current vCPU is discounted from the vCPU power. To account for
826 that, there can be a small performance impact.
827
828 If in doubt, say N here.
829
830config PARAVIRT_CLOCK
831 bool
97349135 832
4a362601
JK
833config JAILHOUSE_GUEST
834 bool "Jailhouse non-root cell support"
abde587b 835 depends on X86_64 && PCI
87e65d05 836 select X86_PM_TIMER
4a362601
JK
837 ---help---
838 This option allows to run Linux as guest in a Jailhouse non-root
839 cell. You can leave this option disabled if you only want to start
840 Jailhouse and run Linux afterwards in the root cell.
841
ec7972c9
ZY
842config ACRN_GUEST
843 bool "ACRN Guest support"
844 depends on X86_64
498ad393 845 select X86_HV_CALLBACK_VECTOR
ec7972c9
ZY
846 help
847 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
848 a flexible, lightweight reference open-source hypervisor, built with
849 real-time and safety-criticality in mind. It is built for embedded
850 IOT with small footprint and real-time features. More details can be
851 found in https://projectacrn.org/.
852
6276a074 853endif #HYPERVISOR_GUEST
97349135 854
506f1d07
SR
855source "arch/x86/Kconfig.cpu"
856
857config HPET_TIMER
3c2362e6 858 def_bool X86_64
506f1d07 859 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
860 ---help---
861 Use the IA-PC HPET (High Precision Event Timer) to manage
862 time in preference to the PIT and RTC, if a HPET is
863 present.
864 HPET is the next generation timer replacing legacy 8254s.
865 The HPET provides a stable time base on SMP
866 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
867 as it is off-chip. The interface used is documented
868 in the HPET spec, revision 1.
506f1d07 869
8f9ca475
IM
870 You can safely choose Y here. However, HPET will only be
871 activated if the platform and the BIOS support this feature.
872 Otherwise the 8254 will be used for timing services.
506f1d07 873
8f9ca475 874 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
875
876config HPET_EMULATE_RTC
3c2362e6 877 def_bool y
9d8af78b 878 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 879
bb24c471 880config APB_TIMER
933b9463
AC
881 def_bool y if X86_INTEL_MID
882 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 883 select DW_APB_TIMER
a0c3832a 884 depends on X86_INTEL_MID && SFI
bb24c471
JP
885 help
886 APB timer is the replacement for 8254, HPET on X86 MID platforms.
887 The APBT provides a stable time base on SMP
888 systems, unlike the TSC, but it is more expensive to access,
889 as it is off-chip. APB timers are always running regardless of CPU
890 C states, they are used as per CPU clockevent device when possible.
891
6a108a14 892# Mark as expert because too many people got it wrong.
506f1d07 893# The code disables itself when not needed.
7ae9392c
TP
894config DMI
895 default y
cf074402 896 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 897 bool "Enable DMI scanning" if EXPERT
8f9ca475 898 ---help---
7ae9392c
TP
899 Enabled scanning of DMI to identify machine quirks. Say Y
900 here unless you have verified that your setup is not
901 affected by entries in the DMI blacklist. Required by PNP
902 BIOS code.
903
506f1d07 904config GART_IOMMU
38901f1c 905 bool "Old AMD GART IOMMU support"
a4ce5a48 906 select IOMMU_HELPER
506f1d07 907 select SWIOTLB
23ac4ae8 908 depends on X86_64 && PCI && AMD_NB
8f9ca475 909 ---help---
ced3c42c
IM
910 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
911 GART based hardware IOMMUs.
912
913 The GART supports full DMA access for devices with 32-bit access
914 limitations, on systems with more than 3 GB. This is usually needed
915 for USB, sound, many IDE/SATA chipsets and some other devices.
916
917 Newer systems typically have a modern AMD IOMMU, supported via
918 the CONFIG_AMD_IOMMU=y config option.
919
920 In normal configurations this driver is only active when needed:
921 there's more than 3 GB of memory and the system contains a
922 32-bit limited device.
923
924 If unsure, say Y.
506f1d07
SR
925
926config CALGARY_IOMMU
927 bool "IBM Calgary IOMMU support"
a4ce5a48 928 select IOMMU_HELPER
506f1d07 929 select SWIOTLB
6ea30386 930 depends on X86_64 && PCI
8f9ca475 931 ---help---
506f1d07
SR
932 Support for hardware IOMMUs in IBM's xSeries x366 and x460
933 systems. Needed to run systems with more than 3GB of memory
934 properly with 32-bit PCI devices that do not support DAC
935 (Double Address Cycle). Calgary also supports bus level
936 isolation, where all DMAs pass through the IOMMU. This
937 prevents them from going anywhere except their intended
938 destination. This catches hard-to-find kernel bugs and
939 mis-behaving drivers and devices that do not use the DMA-API
940 properly to set up their DMA buffers. The IOMMU can be
941 turned off at boot time with the iommu=off parameter.
942 Normally the kernel will make the right choice by itself.
943 If unsure, say Y.
944
945config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
946 def_bool y
947 prompt "Should Calgary be enabled by default?"
506f1d07 948 depends on CALGARY_IOMMU
8f9ca475 949 ---help---
506f1d07
SR
950 Should Calgary be enabled by default? if you choose 'y', Calgary
951 will be used (if it exists). If you choose 'n', Calgary will not be
952 used even if it exists. If you choose 'n' and would like to use
953 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
954 If unsure, say Y.
506f1d07 955
1184dc2f 956config MAXSMP
ddb0c5a6 957 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 958 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 959 select CPUMASK_OFFSTACK
8f9ca475 960 ---help---
ddb0c5a6 961 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 962 If unsure, say N.
506f1d07 963
aec6487e
IM
964#
965# The maximum number of CPUs supported:
966#
967# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
968# and which can be configured interactively in the
969# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
970#
971# The ranges are different on 32-bit and 64-bit kernels, depending on
972# hardware capabilities and scalability features of the kernel.
973#
974# ( If MAXSMP is enabled we just use the highest possible value and disable
975# interactive configuration. )
976#
977
978config NR_CPUS_RANGE_BEGIN
a0d0bb4d 979 int
aec6487e
IM
980 default NR_CPUS_RANGE_END if MAXSMP
981 default 1 if !SMP
982 default 2
a0d0bb4d 983
aec6487e 984config NR_CPUS_RANGE_END
a0d0bb4d 985 int
aec6487e
IM
986 depends on X86_32
987 default 64 if SMP && X86_BIGSMP
988 default 8 if SMP && !X86_BIGSMP
989 default 1 if !SMP
a0d0bb4d 990
aec6487e 991config NR_CPUS_RANGE_END
a0d0bb4d 992 int
aec6487e
IM
993 depends on X86_64
994 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
995 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
996 default 1 if !SMP
a0d0bb4d 997
aec6487e 998config NR_CPUS_DEFAULT
a0d0bb4d
RD
999 int
1000 depends on X86_32
aec6487e
IM
1001 default 32 if X86_BIGSMP
1002 default 8 if SMP
1003 default 1 if !SMP
a0d0bb4d 1004
aec6487e 1005config NR_CPUS_DEFAULT
a0d0bb4d
RD
1006 int
1007 depends on X86_64
aec6487e
IM
1008 default 8192 if MAXSMP
1009 default 64 if SMP
1010 default 1 if !SMP
a0d0bb4d 1011
506f1d07 1012config NR_CPUS
36f5101a 1013 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
1014 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1015 default NR_CPUS_DEFAULT
8f9ca475 1016 ---help---
506f1d07 1017 This allows you to specify the maximum number of CPUs which this
bb61ccc7 1018 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 1019 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
1020 minimum value which makes sense is 2.
1021
aec6487e
IM
1022 This is purely to save memory: each supported CPU adds about 8KB
1023 to the kernel image.
506f1d07
SR
1024
1025config SCHED_SMT
dbe73364 1026 def_bool y if SMP
506f1d07
SR
1027
1028config SCHED_MC
3c2362e6
HH
1029 def_bool y
1030 prompt "Multi-core scheduler support"
c8e56d20 1031 depends on SMP
8f9ca475 1032 ---help---
506f1d07
SR
1033 Multi-core scheduler support improves the CPU scheduler's decision
1034 making when dealing with multi-core CPU chips at a cost of slightly
1035 increased overhead in some places. If unsure say N here.
1036
de966cf4
TC
1037config SCHED_MC_PRIO
1038 bool "CPU core priorities scheduler support"
0a21fc12
IM
1039 depends on SCHED_MC && CPU_SUP_INTEL
1040 select X86_INTEL_PSTATE
1041 select CPU_FREQ
de966cf4 1042 default y
5e76b2ab 1043 ---help---
0a21fc12
IM
1044 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1045 core ordering determined at manufacturing time, which allows
1046 certain cores to reach higher turbo frequencies (when running
1047 single threaded workloads) than others.
de966cf4 1048
0a21fc12
IM
1049 Enabling this kernel feature teaches the scheduler about
1050 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1051 scheduler's CPU selection logic accordingly, so that higher
1052 overall system performance can be achieved.
de966cf4 1053
0a21fc12 1054 This feature will have no effect on CPUs without this feature.
de966cf4 1055
0a21fc12 1056 If unsure say Y here.
5e76b2ab 1057
30b8b006
TG
1058config UP_LATE_INIT
1059 def_bool y
ba360f88 1060 depends on !SMP && X86_LOCAL_APIC
30b8b006 1061
506f1d07 1062config X86_UP_APIC
50849eef
JB
1063 bool "Local APIC support on uniprocessors" if !PCI_MSI
1064 default PCI_MSI
38a1dfda 1065 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1066 ---help---
506f1d07
SR
1067 A local APIC (Advanced Programmable Interrupt Controller) is an
1068 integrated interrupt controller in the CPU. If you have a single-CPU
1069 system which has a processor with a local APIC, you can say Y here to
1070 enable and use it. If you say Y here even though your machine doesn't
1071 have a local APIC, then the kernel will still run with no slowdown at
1072 all. The local APIC supports CPU-generated self-interrupts (timer,
1073 performance counters), and the NMI watchdog which detects hard
1074 lockups.
1075
1076config X86_UP_IOAPIC
1077 bool "IO-APIC support on uniprocessors"
1078 depends on X86_UP_APIC
8f9ca475 1079 ---help---
506f1d07
SR
1080 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1081 SMP-capable replacement for PC-style interrupt controllers. Most
1082 SMP systems and many recent uniprocessor systems have one.
1083
1084 If you have a single-CPU system with an IO-APIC, you can say Y here
1085 to use it. If you say Y here even though your machine doesn't have
1086 an IO-APIC, then the kernel will still run with no slowdown at all.
1087
1088config X86_LOCAL_APIC
3c2362e6 1089 def_bool y
0dbc6078 1090 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1091 select IRQ_DOMAIN_HIERARCHY
52f518a3 1092 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1093
1094config X86_IO_APIC
b1da1e71
JB
1095 def_bool y
1096 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1097
41b9eb26
SA
1098config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1099 bool "Reroute for broken boot IRQs"
41b9eb26 1100 depends on X86_IO_APIC
8f9ca475 1101 ---help---
41b9eb26
SA
1102 This option enables a workaround that fixes a source of
1103 spurious interrupts. This is recommended when threaded
1104 interrupt handling is used on systems where the generation of
1105 superfluous "boot interrupts" cannot be disabled.
1106
1107 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1108 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1109 kernel does during interrupt handling). On chipsets where this
1110 boot IRQ generation cannot be disabled, this workaround keeps
1111 the original IRQ line masked so that only the equivalent "boot
1112 IRQ" is delivered to the CPUs. The workaround also tells the
1113 kernel to set up the IRQ handler on the boot IRQ line. In this
1114 way only one interrupt is delivered to the kernel. Otherwise
1115 the spurious second interrupt may cause the kernel to bring
1116 down (vital) interrupt lines.
1117
1118 Only affects "broken" chipsets. Interrupt sharing may be
1119 increased on these systems.
1120
506f1d07 1121config X86_MCE
bab9bc65 1122 bool "Machine Check / overheating reporting"
648ed940 1123 select GENERIC_ALLOCATOR
e57dbaf7 1124 default y
506f1d07 1125 ---help---
bab9bc65
AK
1126 Machine Check support allows the processor to notify the
1127 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1128 The action the kernel takes depends on the severity of the problem,
bab9bc65 1129 ranging from warning messages to halting the machine.
4efc0670 1130
5de97c9f
TL
1131config X86_MCELOG_LEGACY
1132 bool "Support for deprecated /dev/mcelog character device"
1133 depends on X86_MCE
1134 ---help---
1135 Enable support for /dev/mcelog which is needed by the old mcelog
1136 userspace logging daemon. Consider switching to the new generation
1137 rasdaemon solution.
1138
506f1d07 1139config X86_MCE_INTEL
3c2362e6
HH
1140 def_bool y
1141 prompt "Intel MCE features"
c1ebf835 1142 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1143 ---help---
506f1d07
SR
1144 Additional support for intel specific MCE features such as
1145 the thermal monitor.
1146
1147config X86_MCE_AMD
3c2362e6
HH
1148 def_bool y
1149 prompt "AMD MCE features"
f5382de9 1150 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1151 ---help---
506f1d07
SR
1152 Additional support for AMD specific MCE features such as
1153 the DRAM Error Threshold.
1154
4efc0670 1155config X86_ANCIENT_MCE
6fc108a0 1156 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1157 depends on X86_32 && X86_MCE
cd13adcc
HS
1158 ---help---
1159 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1160 systems. These typically need to be enabled explicitly on the command
cd13adcc 1161 line.
4efc0670 1162
b2762686
AK
1163config X86_MCE_THRESHOLD
1164 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1165 def_bool y
b2762686 1166
ea149b36 1167config X86_MCE_INJECT
bc8e80d5 1168 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1169 tristate "Machine check injector support"
1170 ---help---
1171 Provide support for injecting machine checks for testing purposes.
1172 If you don't know what a machine check is and you don't do kernel
1173 QA it is safe to say n.
1174
4efc0670
AK
1175config X86_THERMAL_VECTOR
1176 def_bool y
5bb38adc 1177 depends on X86_MCE_INTEL
4efc0670 1178
07dc900e 1179source "arch/x86/events/Kconfig"
e633c65a 1180
5aef51c3 1181config X86_LEGACY_VM86
1e642812 1182 bool "Legacy VM86 support"
506f1d07 1183 depends on X86_32
8f9ca475 1184 ---help---
5aef51c3
AL
1185 This option allows user programs to put the CPU into V8086
1186 mode, which is an 80286-era approximation of 16-bit real mode.
1187
1188 Some very old versions of X and/or vbetool require this option
1189 for user mode setting. Similarly, DOSEMU will use it if
1190 available to accelerate real mode DOS programs. However, any
1191 recent version of DOSEMU, X, or vbetool should be fully
1192 functional even without kernel VM86 support, as they will all
1e642812
IM
1193 fall back to software emulation. Nevertheless, if you are using
1194 a 16-bit DOS program where 16-bit performance matters, vm86
1195 mode might be faster than emulation and you might want to
1196 enable this option.
5aef51c3 1197
1e642812
IM
1198 Note that any app that works on a 64-bit kernel is unlikely to
1199 need this option, as 64-bit kernels don't, and can't, support
1200 V8086 mode. This option is also unrelated to 16-bit protected
1201 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1202
1e642812
IM
1203 Enabling this option increases the complexity of the kernel
1204 and slows down exception handling a tiny bit.
5aef51c3 1205
1e642812 1206 If unsure, say N here.
5aef51c3
AL
1207
1208config VM86
1209 bool
1210 default X86_LEGACY_VM86
34273f41
PA
1211
1212config X86_16BIT
1213 bool "Enable support for 16-bit segments" if EXPERT
1214 default y
a5b9e5a2 1215 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1216 ---help---
1217 This option is required by programs like Wine to run 16-bit
1218 protected mode legacy code on x86 processors. Disabling
1219 this option saves about 300 bytes on i386, or around 6K text
1220 plus 16K runtime memory on x86-64,
1221
1222config X86_ESPFIX32
1223 def_bool y
1224 depends on X86_16BIT && X86_32
506f1d07 1225
197725de
PA
1226config X86_ESPFIX64
1227 def_bool y
34273f41 1228 depends on X86_16BIT && X86_64
506f1d07 1229
1ad83c85
AL
1230config X86_VSYSCALL_EMULATION
1231 bool "Enable vsyscall emulation" if EXPERT
1232 default y
1233 depends on X86_64
1234 ---help---
1235 This enables emulation of the legacy vsyscall page. Disabling
1236 it is roughly equivalent to booting with vsyscall=none, except
1237 that it will also disable the helpful warning if a program
1238 tries to use a vsyscall. With this option set to N, offending
1239 programs will just segfault, citing addresses of the form
1240 0xffffffffff600?00.
1241
1242 This option is required by many programs built before 2013, and
1243 care should be used even with newer programs if set to N.
1244
1245 Disabling this option saves about 7K of kernel size and
1246 possibly 4K of additional runtime pagetable memory.
1247
506f1d07
SR
1248config TOSHIBA
1249 tristate "Toshiba Laptop support"
1250 depends on X86_32
1251 ---help---
1252 This adds a driver to safely access the System Management Mode of
1253 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254 not work on models with a Phoenix BIOS. The System Management Mode
1255 is used to set the BIOS and power saving options on Toshiba portables.
1256
1257 For information on utilities to make use of this driver see the
1258 Toshiba Linux utilities web site at:
1259 <http://www.buzzard.org.uk/toshiba/>.
1260
1261 Say Y if you intend to run this kernel on a Toshiba portable.
1262 Say N otherwise.
1263
1264config I8K
039ae585 1265 tristate "Dell i8k legacy laptop support"
949a9d70 1266 select HWMON
039ae585 1267 select SENSORS_DELL_SMM
506f1d07 1268 ---help---
039ae585
PR
1269 This option enables legacy /proc/i8k userspace interface in hwmon
1270 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1271 temperature and allows controlling fan speeds of Dell laptops via
1272 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1273 it reports also power and hotkey status. For fan speed control is
1274 needed userspace package i8kutils.
1275
1276 Say Y if you intend to run this kernel on old Dell laptops or want to
1277 use userspace package i8kutils.
506f1d07
SR
1278 Say N otherwise.
1279
1280config X86_REBOOTFIXUPS
9ba16087
JB
1281 bool "Enable X86 board specific fixups for reboot"
1282 depends on X86_32
506f1d07
SR
1283 ---help---
1284 This enables chipset and/or board specific fixups to be done
1285 in order to get reboot to work correctly. This is only needed on
1286 some combinations of hardware and BIOS. The symptom, for which
1287 this config is intended, is when reboot ends with a stalled/hung
1288 system.
1289
1290 Currently, the only fixup is for the Geode machines using
5e3a77e9 1291 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1292
1293 Say Y if you want to enable the fixup. Currently, it's safe to
1294 enable this option even if you don't need it.
1295 Say N otherwise.
1296
1297config MICROCODE
9a2bc335
BP
1298 bool "CPU microcode loading support"
1299 default y
80030e3d 1300 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1301 select FW_LOADER
1302 ---help---
1303 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1304 Intel and AMD processors. The Intel support is for the IA32 family,
1305 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1306 AMD support is for families 0x10 and later. You will obviously need
1307 the actual microcode binary data itself which is not shipped with
1308 the Linux kernel.
1309
1310 The preferred method to load microcode from a detached initrd is described
cb1aaebe 1311 in Documentation/x86/microcode.rst. For that you need to enable
5f9c01aa
BP
1312 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1313 initrd for microcode blobs.
1314
c508c46e
BG
1315 In addition, you can build the microcode into the kernel. For that you
1316 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1317 config option.
506f1d07 1318
8d86f390 1319config MICROCODE_INTEL
e43f6e67 1320 bool "Intel microcode loading support"
8f9ca475
IM
1321 depends on MICROCODE
1322 default MICROCODE
1323 select FW_LOADER
1324 ---help---
1325 This options enables microcode patch loading support for Intel
1326 processors.
1327
b8989db9
A
1328 For the current Intel microcode data package go to
1329 <https://downloadcenter.intel.com> and search for
1330 'Linux Processor Microcode Data File'.
8d86f390 1331
80cc9f10 1332config MICROCODE_AMD
e43f6e67 1333 bool "AMD microcode loading support"
8f9ca475
IM
1334 depends on MICROCODE
1335 select FW_LOADER
1336 ---help---
1337 If you select this option, microcode patch loading support for AMD
1338 processors will be enabled.
80cc9f10 1339
8f9ca475 1340config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1341 bool "Ancient loading interface (DEPRECATED)"
1342 default n
506f1d07 1343 depends on MICROCODE
c02f48e0
BP
1344 ---help---
1345 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1346 which was used by userspace tools like iucode_tool and microcode.ctl.
1347 It is inadequate because it runs too late to be able to properly
1348 load microcode on a machine and it needs special tools. Instead, you
1349 should've switched to the early loading method with the initrd or
cb1aaebe 1350 builtin microcode by now: Documentation/x86/microcode.rst
506f1d07
SR
1351
1352config X86_MSR
1353 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1354 ---help---
506f1d07
SR
1355 This device gives privileged processes access to the x86
1356 Model-Specific Registers (MSRs). It is a character device with
1357 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358 MSR accesses are directed to a specific CPU on multi-processor
1359 systems.
1360
1361config X86_CPUID
1362 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1363 ---help---
506f1d07
SR
1364 This device gives processes access to the x86 CPUID instruction to
1365 be executed on a specific processor. It is a character device
1366 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367 /dev/cpu/31/cpuid.
1368
1369choice
1370 prompt "High Memory Support"
6fc108a0 1371 default HIGHMEM4G
506f1d07
SR
1372 depends on X86_32
1373
1374config NOHIGHMEM
1375 bool "off"
506f1d07
SR
1376 ---help---
1377 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378 However, the address space of 32-bit x86 processors is only 4
1379 Gigabytes large. That means that, if you have a large amount of
1380 physical memory, not all of it can be "permanently mapped" by the
1381 kernel. The physical memory that's not permanently mapped is called
1382 "high memory".
1383
1384 If you are compiling a kernel which will never run on a machine with
1385 more than 1 Gigabyte total physical RAM, answer "off" here (default
1386 choice and suitable for most users). This will result in a "3GB/1GB"
1387 split: 3GB are mapped so that each process sees a 3GB virtual memory
1388 space and the remaining part of the 4GB virtual memory space is used
1389 by the kernel to permanently map as much physical memory as
1390 possible.
1391
1392 If the machine has between 1 and 4 Gigabytes physical RAM, then
1393 answer "4GB" here.
1394
1395 If more than 4 Gigabytes is used then answer "64GB" here. This
1396 selection turns Intel PAE (Physical Address Extension) mode on.
1397 PAE implements 3-level paging on IA32 processors. PAE is fully
1398 supported by Linux, PAE mode is implemented on all recent Intel
1399 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400 then the kernel will not boot on CPUs that don't support PAE!
1401
1402 The actual amount of total physical memory will either be
1403 auto detected or can be forced by using a kernel command line option
1404 such as "mem=256M". (Try "man bootparam" or see the documentation of
1405 your boot loader (lilo or loadlin) about how to pass options to the
1406 kernel at boot time.)
1407
1408 If unsure, say "off".
1409
1410config HIGHMEM4G
1411 bool "4GB"
8f9ca475 1412 ---help---
506f1d07
SR
1413 Select this if you have a 32-bit processor and between 1 and 4
1414 gigabytes of physical RAM.
1415
1416config HIGHMEM64G
1417 bool "64GB"
69b8d3fc 1418 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1419 select X86_PAE
8f9ca475 1420 ---help---
506f1d07
SR
1421 Select this if you have a 32-bit processor and more than 4
1422 gigabytes of physical RAM.
1423
1424endchoice
1425
1426choice
6a108a14 1427 prompt "Memory split" if EXPERT
506f1d07
SR
1428 default VMSPLIT_3G
1429 depends on X86_32
8f9ca475 1430 ---help---
506f1d07
SR
1431 Select the desired split between kernel and user memory.
1432
1433 If the address range available to the kernel is less than the
1434 physical memory installed, the remaining memory will be available
1435 as "high memory". Accessing high memory is a little more costly
1436 than low memory, as it needs to be mapped into the kernel first.
1437 Note that increasing the kernel address space limits the range
1438 available to user programs, making the address space there
1439 tighter. Selecting anything other than the default 3G/1G split
1440 will also likely make your kernel incompatible with binary-only
1441 kernel modules.
1442
1443 If you are not absolutely sure what you are doing, leave this
1444 option alone!
1445
1446 config VMSPLIT_3G
1447 bool "3G/1G user/kernel split"
1448 config VMSPLIT_3G_OPT
1449 depends on !X86_PAE
1450 bool "3G/1G user/kernel split (for full 1G low memory)"
1451 config VMSPLIT_2G
1452 bool "2G/2G user/kernel split"
1453 config VMSPLIT_2G_OPT
1454 depends on !X86_PAE
1455 bool "2G/2G user/kernel split (for full 2G low memory)"
1456 config VMSPLIT_1G
1457 bool "1G/3G user/kernel split"
1458endchoice
1459
1460config PAGE_OFFSET
1461 hex
1462 default 0xB0000000 if VMSPLIT_3G_OPT
1463 default 0x80000000 if VMSPLIT_2G
1464 default 0x78000000 if VMSPLIT_2G_OPT
1465 default 0x40000000 if VMSPLIT_1G
1466 default 0xC0000000
1467 depends on X86_32
1468
1469config HIGHMEM
3c2362e6 1470 def_bool y
506f1d07 1471 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1472
1473config X86_PAE
9ba16087 1474 bool "PAE (Physical Address Extension) Support"
506f1d07 1475 depends on X86_32 && !HIGHMEM4G
d4a451d5 1476 select PHYS_ADDR_T_64BIT
9d99c712 1477 select SWIOTLB
8f9ca475 1478 ---help---
506f1d07
SR
1479 PAE is required for NX support, and furthermore enables
1480 larger swapspace support for non-overcommit purposes. It
1481 has the cost of more pagetable lookup overhead, and also
1482 consumes more pagetable space per process.
1483
77ef56e4
KS
1484config X86_5LEVEL
1485 bool "Enable 5-level page tables support"
eedb92ab 1486 select DYNAMIC_MEMORY_LAYOUT
162434e7 1487 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1488 depends on X86_64
1489 ---help---
1490 5-level paging enables access to larger address space:
1491 upto 128 PiB of virtual address space and 4 PiB of
1492 physical address space.
1493
1494 It will be supported by future Intel CPUs.
1495
6657fca0
KS
1496 A kernel with the option enabled can be booted on machines that
1497 support 4- or 5-level paging.
77ef56e4 1498
cb1aaebe 1499 See Documentation/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1500 information.
1501
1502 Say N if unsure.
1503
10971ab2 1504config X86_DIRECT_GBPAGES
e5008abe 1505 def_bool y
4675ff05 1506 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1507 ---help---
10971ab2
IM
1508 Certain kernel features effectively disable kernel
1509 linear 1 GB mappings (even if the CPU otherwise
1510 supports them), so don't confuse the user by printing
1511 that we have them enabled.
9e899816 1512
5c280cf6
TG
1513config X86_CPA_STATISTICS
1514 bool "Enable statistic for Change Page Attribute"
1515 depends on DEBUG_FS
1516 ---help---
1517 Expose statistics about the Change Page Attribute mechanims, which
a943245a 1518 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1519 page mappings when mapping protections are changed.
1520
7744ccdb
TL
1521config ARCH_HAS_MEM_ENCRYPT
1522 def_bool y
1523
1524config AMD_MEM_ENCRYPT
1525 bool "AMD Secure Memory Encryption (SME) support"
1526 depends on X86_64 && CPU_SUP_AMD
94d49eb3 1527 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1528 select ARCH_USE_MEMREMAP_PROT
9087c375 1529 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
7744ccdb
TL
1530 ---help---
1531 Say yes to enable support for the encryption of system memory.
1532 This requires an AMD processor that supports Secure Memory
1533 Encryption (SME).
1534
1535config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1536 bool "Activate AMD Secure Memory Encryption (SME) by default"
1537 default y
1538 depends on AMD_MEM_ENCRYPT
1539 ---help---
1540 Say yes to have system memory encrypted by default if running on
1541 an AMD processor that supports Secure Memory Encryption (SME).
1542
1543 If set to Y, then the encryption of system memory can be
1544 deactivated with the mem_encrypt=off command line option.
1545
1546 If set to N, then the encryption of system memory can be
1547 activated with the mem_encrypt=on command line option.
1548
506f1d07
SR
1549# Common NUMA Features
1550config NUMA
fd51b2d7 1551 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1552 depends on SMP
b5660ba7
PA
1553 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554 default y if X86_BIGSMP
8f9ca475 1555 ---help---
506f1d07 1556 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1557
506f1d07
SR
1558 The kernel will try to allocate memory used by a CPU on the
1559 local memory controller of the CPU and add some more
1560 NUMA awareness to the kernel.
1561
c280ea5e 1562 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1563 (or later), AMD Opteron, or EM64T NUMA.
1564
b5660ba7 1565 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1566 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1567
1568 Otherwise, you should say N.
506f1d07 1569
eec1d4fa 1570config AMD_NUMA
3c2362e6
HH
1571 def_bool y
1572 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1573 depends on X86_64 && NUMA && PCI
8f9ca475 1574 ---help---
eec1d4fa
HR
1575 Enable AMD NUMA node topology detection. You should say Y here if
1576 you have a multi processor AMD system. This uses an old method to
1577 read the NUMA configuration directly from the builtin Northbridge
1578 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1579 which also takes priority if both are compiled in.
506f1d07
SR
1580
1581config X86_64_ACPI_NUMA
3c2362e6
HH
1582 def_bool y
1583 prompt "ACPI NUMA detection"
506f1d07
SR
1584 depends on X86_64 && NUMA && ACPI && PCI
1585 select ACPI_NUMA
8f9ca475 1586 ---help---
506f1d07
SR
1587 Enable ACPI SRAT based node topology detection.
1588
6ec6e0d9
SS
1589# Some NUMA nodes have memory ranges that span
1590# other nodes. Even though a pfn is valid and
1591# between a node's start and end pfns, it may not
1592# reside on that node. See memmap_init_zone()
1593# for details.
1594config NODES_SPAN_OTHER_NODES
1595 def_bool y
1596 depends on X86_64_ACPI_NUMA
1597
506f1d07
SR
1598config NUMA_EMU
1599 bool "NUMA emulation"
1b7e03ef 1600 depends on NUMA
8f9ca475 1601 ---help---
506f1d07
SR
1602 Enable NUMA emulation. A flat machine will be split
1603 into virtual nodes when booted with "numa=fake=N", where N is the
1604 number of nodes. This is only useful for debugging.
1605
1606config NODES_SHIFT
d25e26b6 1607 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1608 range 1 10
1609 default "10" if MAXSMP
506f1d07 1610 default "6" if X86_64
506f1d07
SR
1611 default "3"
1612 depends on NEED_MULTIPLE_NODES
8f9ca475 1613 ---help---
1184dc2f 1614 Specify the maximum number of NUMA Nodes available on the target
692105b8 1615 system. Increases memory reserved to accommodate various tables.
506f1d07 1616
506f1d07 1617config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1618 def_bool y
506f1d07 1619 depends on X86_32 && DISCONTIGMEM
506f1d07 1620
506f1d07
SR
1621config ARCH_FLATMEM_ENABLE
1622 def_bool y
3b16651f 1623 depends on X86_32 && !NUMA
506f1d07
SR
1624
1625config ARCH_DISCONTIGMEM_ENABLE
2792107d 1626 def_bool n
b263295d 1627 depends on NUMA && X86_32
2792107d 1628 depends on BROKEN
b263295d 1629
506f1d07
SR
1630config ARCH_SPARSEMEM_ENABLE
1631 def_bool y
6ea30386 1632 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1633 select SPARSEMEM_STATIC if X86_32
1634 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1635
3b16651f 1636config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1637 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1638
506f1d07
SR
1639config ARCH_SELECT_MEMORY_MODEL
1640 def_bool y
b263295d 1641 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1642
1643config ARCH_MEMORY_PROBE
a0842b70 1644 bool "Enable sysfs memory/probe interface"
3120e25e 1645 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1646 help
1647 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1648 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1649 If you are unsure how to answer this question, answer N.
506f1d07 1650
3b16651f
TH
1651config ARCH_PROC_KCORE_TEXT
1652 def_bool y
1653 depends on X86_64 && PROC_KCORE
1654
a29815a3
AK
1655config ILLEGAL_POINTER_VALUE
1656 hex
1657 default 0 if X86_32
1658 default 0xdead000000000000 if X86_64
1659
7a67832c
DW
1660config X86_PMEM_LEGACY_DEVICE
1661 bool
1662
ec776ef6 1663config X86_PMEM_LEGACY
7a67832c 1664 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1665 depends on PHYS_ADDR_T_64BIT
1666 depends on BLK_DEV
7a67832c 1667 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1668 select LIBNVDIMM
ec776ef6
CH
1669 help
1670 Treat memory marked using the non-standard e820 type of 12 as used
1671 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1672 The kernel will offer these regions to the 'pmem' driver so
1673 they can be used for persistent storage.
1674
1675 Say Y if unsure.
1676
506f1d07
SR
1677config HIGHPTE
1678 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1679 depends on HIGHMEM
8f9ca475 1680 ---help---
506f1d07
SR
1681 The VM uses one page table entry for each page of physical memory.
1682 For systems with a lot of RAM, this can be wasteful of precious
1683 low memory. Setting this option will put user-space page table
1684 entries in high memory.
1685
9f077871 1686config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1687 bool "Check for low memory corruption"
1688 ---help---
1689 Periodically check for memory corruption in low memory, which
1690 is suspected to be caused by BIOS. Even when enabled in the
1691 configuration, it is disabled at runtime. Enable it by
1692 setting "memory_corruption_check=1" on the kernel command
1693 line. By default it scans the low 64k of memory every 60
1694 seconds; see the memory_corruption_check_size and
1695 memory_corruption_check_period parameters in
8c27ceff 1696 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1697
1698 When enabled with the default parameters, this option has
1699 almost no overhead, as it reserves a relatively small amount
1700 of memory and scans it infrequently. It both detects corruption
1701 and prevents it from affecting the running system.
1702
1703 It is, however, intended as a diagnostic tool; if repeatable
1704 BIOS-originated corruption always affects the same memory,
1705 you can use memmap= to prevent the kernel from using that
1706 memory.
9f077871 1707
c885df50 1708config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1709 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1710 depends on X86_CHECK_BIOS_CORRUPTION
1711 default y
8f9ca475
IM
1712 ---help---
1713 Set whether the default state of memory_corruption_check is
1714 on or off.
c885df50 1715
9ea77bdb 1716config X86_RESERVE_LOW
d0cd7425
PA
1717 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1718 default 64
1719 range 4 640
8f9ca475 1720 ---help---
d0cd7425
PA
1721 Specify the amount of low memory to reserve for the BIOS.
1722
1723 The first page contains BIOS data structures that the kernel
1724 must not use, so that page must always be reserved.
1725
1726 By default we reserve the first 64K of physical RAM, as a
1727 number of BIOSes are known to corrupt that memory range
1728 during events such as suspend/resume or monitor cable
1729 insertion, so it must not be used by the kernel.
fc381519 1730
d0cd7425
PA
1731 You can set this to 4 if you are absolutely sure that you
1732 trust the BIOS to get all its memory reservations and usages
1733 right. If you know your BIOS have problems beyond the
1734 default 64K area, you can set this to 640 to avoid using the
1735 entire low memory range.
fc381519 1736
d0cd7425
PA
1737 If you have doubts about the BIOS (e.g. suspend/resume does
1738 not work or there's kernel crashes after certain hardware
1739 hotplug events) then you might want to enable
1740 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1741 typical corruption patterns.
fc381519 1742
d0cd7425 1743 Leave this to the default value of 64 if you are unsure.
fc381519 1744
506f1d07
SR
1745config MATH_EMULATION
1746 bool
a5b9e5a2 1747 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1748 prompt "Math emulation" if X86_32
1749 ---help---
1750 Linux can emulate a math coprocessor (used for floating point
1751 operations) if you don't have one. 486DX and Pentium processors have
1752 a math coprocessor built in, 486SX and 386 do not, unless you added
1753 a 487DX or 387, respectively. (The messages during boot time can
1754 give you some hints here ["man dmesg"].) Everyone needs either a
1755 coprocessor or this emulation.
1756
1757 If you don't have a math coprocessor, you need to say Y here; if you
1758 say Y here even though you have a coprocessor, the coprocessor will
1759 be used nevertheless. (This behavior can be changed with the kernel
1760 command line option "no387", which comes handy if your coprocessor
1761 is broken. Try "man bootparam" or see the documentation of your boot
1762 loader (lilo or loadlin) about how to pass options to the kernel at
1763 boot time.) This means that it is a good idea to say Y here if you
1764 intend to use this kernel on different machines.
1765
1766 More information about the internals of the Linux math coprocessor
1767 emulation can be found in <file:arch/x86/math-emu/README>.
1768
1769 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1770 kernel, it won't hurt.
1771
1772config MTRR
6fc108a0 1773 def_bool y
6a108a14 1774 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1775 ---help---
1776 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1777 the Memory Type Range Registers (MTRRs) may be used to control
1778 processor access to memory ranges. This is most useful if you have
1779 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1780 allows bus write transfers to be combined into a larger transfer
1781 before bursting over the PCI/AGP bus. This can increase performance
1782 of image write operations 2.5 times or more. Saying Y here creates a
1783 /proc/mtrr file which may be used to manipulate your processor's
1784 MTRRs. Typically the X server should use this.
1785
1786 This code has a reasonably generic interface so that similar
1787 control registers on other processors can be easily supported
1788 as well:
1789
1790 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1791 Registers (ARRs) which provide a similar functionality to MTRRs. For
1792 these, the ARRs are used to emulate the MTRRs.
1793 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1794 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1795 write-combining. All of these processors are supported by this code
1796 and it makes sense to say Y here if you have one of them.
1797
1798 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1799 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1800 can lead to all sorts of problems, so it's good to say Y here.
1801
1802 You can safely say Y even if your machine doesn't have MTRRs, you'll
1803 just add about 9 KB to your kernel.
1804
cb1aaebe 1805 See <file:Documentation/x86/mtrr.rst> for more information.
506f1d07 1806
95ffa243 1807config MTRR_SANITIZER
2ffb3501 1808 def_bool y
95ffa243
YL
1809 prompt "MTRR cleanup support"
1810 depends on MTRR
8f9ca475 1811 ---help---
aba3728c
TG
1812 Convert MTRR layout from continuous to discrete, so X drivers can
1813 add writeback entries.
95ffa243 1814
aba3728c 1815 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1816 The largest mtrr entry size for a continuous block can be set with
aba3728c 1817 mtrr_chunk_size.
95ffa243 1818
2ffb3501 1819 If unsure, say Y.
95ffa243
YL
1820
1821config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1822 int "MTRR cleanup enable value (0-1)"
1823 range 0 1
1824 default "0"
95ffa243 1825 depends on MTRR_SANITIZER
8f9ca475 1826 ---help---
f5098d62 1827 Enable mtrr cleanup default value
95ffa243 1828
12031a62
YL
1829config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1830 int "MTRR cleanup spare reg num (0-7)"
1831 range 0 7
1832 default "1"
1833 depends on MTRR_SANITIZER
8f9ca475 1834 ---help---
12031a62 1835 mtrr cleanup spare entries default, it can be changed via
aba3728c 1836 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1837
2e5d9c85 1838config X86_PAT
6fc108a0 1839 def_bool y
6a108a14 1840 prompt "x86 PAT support" if EXPERT
2a8a2719 1841 depends on MTRR
8f9ca475 1842 ---help---
2e5d9c85 1843 Use PAT attributes to setup page level cache control.
042b78e4 1844
2e5d9c85 1845 PATs are the modern equivalents of MTRRs and are much more
1846 flexible than MTRRs.
1847
1848 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1849 spontaneous reboots) or a non-working video driver.
2e5d9c85 1850
1851 If unsure, say Y.
1852
46cf98cd
VP
1853config ARCH_USES_PG_UNCACHED
1854 def_bool y
1855 depends on X86_PAT
1856
628c6246
PA
1857config ARCH_RANDOM
1858 def_bool y
1859 prompt "x86 architectural random number generator" if EXPERT
1860 ---help---
1861 Enable the x86 architectural RDRAND instruction
1862 (Intel Bull Mountain technology) to generate random numbers.
1863 If supported, this is a high bandwidth, cryptographically
1864 secure hardware random number generator.
1865
51ae4a2d
PA
1866config X86_SMAP
1867 def_bool y
1868 prompt "Supervisor Mode Access Prevention" if EXPERT
1869 ---help---
1870 Supervisor Mode Access Prevention (SMAP) is a security
1871 feature in newer Intel processors. There is a small
1872 performance cost if this enabled and turned on; there is
1873 also a small increase in the kernel size if this is enabled.
1874
1875 If unsure, say Y.
1876
aa35f896 1877config X86_INTEL_UMIP
796ebc81 1878 def_bool y
aa35f896
RN
1879 depends on CPU_SUP_INTEL
1880 prompt "Intel User Mode Instruction Prevention" if EXPERT
1881 ---help---
1882 The User Mode Instruction Prevention (UMIP) is a security
1883 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1884 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1885 or STR instructions are executed in user mode. These instructions
1886 unnecessarily expose information about the hardware state.
1887
1888 The vast majority of applications do not use these instructions.
1889 For the very few that do, software emulation is provided in
1890 specific cases in protected and virtual-8086 modes. Emulated
1891 results are dummy.
aa35f896 1892
72e9b5fe
DH
1893config X86_INTEL_MPX
1894 prompt "Intel MPX (Memory Protection Extensions)"
1895 def_bool n
df3735c5
RR
1896 # Note: only available in 64-bit mode due to VMA flags shortage
1897 depends on CPU_SUP_INTEL && X86_64
1898 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1899 ---help---
1900 MPX provides hardware features that can be used in
1901 conjunction with compiler-instrumented code to check
1902 memory references. It is designed to detect buffer
1903 overflow or underflow bugs.
1904
1905 This option enables running applications which are
1906 instrumented or otherwise use MPX. It does not use MPX
1907 itself inside the kernel or to protect the kernel
1908 against bad memory references.
1909
1910 Enabling this option will make the kernel larger:
1911 ~8k of kernel text and 36 bytes of data on a 64-bit
1912 defconfig. It adds a long to the 'mm_struct' which
1913 will increase the kernel memory overhead of each
1914 process and adds some branches to paths used during
1915 exec() and munmap().
1916
cb1aaebe 1917 For details, see Documentation/x86/intel_mpx.rst
72e9b5fe
DH
1918
1919 If unsure, say N.
1920
35e97790 1921config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1922 prompt "Intel Memory Protection Keys"
35e97790 1923 def_bool y
284244a9 1924 # Note: only available in 64-bit mode
35e97790 1925 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1926 select ARCH_USES_HIGH_VMA_FLAGS
1927 select ARCH_HAS_PKEYS
284244a9
DH
1928 ---help---
1929 Memory Protection Keys provides a mechanism for enforcing
1930 page-based protections, but without requiring modification of the
1931 page tables when an application changes protection domains.
1932
1eecbcdc 1933 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1934
1935 If unsure, say y.
35e97790 1936
506f1d07 1937config EFI
9ba16087 1938 bool "EFI runtime service support"
5b83683f 1939 depends on ACPI
f6ce5002 1940 select UCS2_STRING
022ee6c5 1941 select EFI_RUNTIME_WRAPPERS
506f1d07 1942 ---help---
8f9ca475
IM
1943 This enables the kernel to use EFI runtime services that are
1944 available (such as the EFI variable services).
506f1d07 1945
8f9ca475
IM
1946 This option is only useful on systems that have EFI firmware.
1947 In addition, you should use the latest ELILO loader available
1948 at <http://elilo.sourceforge.net> in order to take advantage
1949 of EFI runtime services. However, even with this option, the
1950 resultant kernel should continue to boot on existing non-EFI
1951 platforms.
506f1d07 1952
291f3632
MF
1953config EFI_STUB
1954 bool "EFI stub support"
b16d8c23 1955 depends on EFI && !X86_USE_3DNOW
7b2a583a 1956 select RELOCATABLE
291f3632
MF
1957 ---help---
1958 This kernel feature allows a bzImage to be loaded directly
1959 by EFI firmware without the use of a bootloader.
1960
4f4cfa6c 1961 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 1962
7d453eee
MF
1963config EFI_MIXED
1964 bool "EFI mixed-mode support"
1965 depends on EFI_STUB && X86_64
1966 ---help---
1967 Enabling this feature allows a 64-bit kernel to be booted
1968 on a 32-bit firmware, provided that your CPU supports 64-bit
1969 mode.
1970
1971 Note that it is not possible to boot a mixed-mode enabled
1972 kernel via the EFI boot stub - a bootloader that supports
1973 the EFI handover protocol must be used.
1974
1975 If unsure, say N.
1976
506f1d07 1977config SECCOMP
3c2362e6
HH
1978 def_bool y
1979 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1980 ---help---
506f1d07
SR
1981 This kernel feature is useful for number crunching applications
1982 that may need to compute untrusted bytecode during their
1983 execution. By using pipes or other transports made available to
1984 the process as file descriptors supporting the read/write
1985 syscalls, it's possible to isolate those applications in
1986 their own address space using seccomp. Once seccomp is
9c0bbee8 1987 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1988 and the task is only allowed to execute a few safe syscalls
1989 defined by each seccomp mode.
1990
1991 If unsure, say Y. Only embedded should say N here.
1992
8636a1f9 1993source "kernel/Kconfig.hz"
506f1d07
SR
1994
1995config KEXEC
1996 bool "kexec system call"
2965faa5 1997 select KEXEC_CORE
8f9ca475 1998 ---help---
506f1d07
SR
1999 kexec is a system call that implements the ability to shutdown your
2000 current kernel, and to start another kernel. It is like a reboot
2001 but it is independent of the system firmware. And like a reboot
2002 you can start any kernel with it, not just Linux.
2003
2004 The name comes from the similarity to the exec system call.
2005
2006 It is an ongoing process to be certain the hardware in a machine
2007 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
2008 initially work for you. As of this writing the exact hardware
2009 interface is strongly in flux, so no good recommendation can be
2010 made.
506f1d07 2011
74ca317c
VG
2012config KEXEC_FILE
2013 bool "kexec file based system call"
2965faa5 2014 select KEXEC_CORE
74ca317c 2015 select BUILD_BIN2C
74ca317c
VG
2016 depends on X86_64
2017 depends on CRYPTO=y
2018 depends on CRYPTO_SHA256=y
2019 ---help---
2020 This is new version of kexec system call. This system call is
2021 file based and takes file descriptors as system call argument
2022 for kernel and initramfs as opposed to list of segments as
2023 accepted by previous system call.
2024
b799a09f
AT
2025config ARCH_HAS_KEXEC_PURGATORY
2026 def_bool KEXEC_FILE
2027
8e7d8381
VG
2028config KEXEC_VERIFY_SIG
2029 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2030 depends on KEXEC_FILE
8e7d8381
VG
2031 ---help---
2032 This option makes kernel signature verification mandatory for
d8eb8940
BP
2033 the kexec_file_load() syscall.
2034
2035 In addition to that option, you need to enable signature
2036 verification for the corresponding kernel image type being
2037 loaded in order for this to work.
8e7d8381
VG
2038
2039config KEXEC_BZIMAGE_VERIFY_SIG
2040 bool "Enable bzImage signature verification support"
2041 depends on KEXEC_VERIFY_SIG
2042 depends on SIGNED_PE_FILE_VERIFICATION
2043 select SYSTEM_TRUSTED_KEYRING
2044 ---help---
2045 Enable bzImage signature verification support.
2046
506f1d07 2047config CRASH_DUMP
04b69447 2048 bool "kernel crash dumps"
506f1d07 2049 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2050 ---help---
506f1d07
SR
2051 Generate crash dump after being started by kexec.
2052 This should be normally only set in special crash dump kernels
2053 which are loaded in the main kernel with kexec-tools into
2054 a specially reserved region and then later executed after
2055 a crash by kdump/kexec. The crash dump kernel must be compiled
2056 to a memory address not used by the main kernel or BIOS using
2057 PHYSICAL_START, or it must be built as a relocatable image
2058 (CONFIG_RELOCATABLE=y).
330d4810 2059 For more details see Documentation/admin-guide/kdump/kdump.rst
506f1d07 2060
3ab83521 2061config KEXEC_JUMP
6ea30386 2062 bool "kexec jump"
fee7b0d8 2063 depends on KEXEC && HIBERNATION
8f9ca475 2064 ---help---
89081d17
HY
2065 Jump between original kernel and kexeced kernel and invoke
2066 code in physical address mode via KEXEC
3ab83521 2067
506f1d07 2068config PHYSICAL_START
6a108a14 2069 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2070 default "0x1000000"
8f9ca475 2071 ---help---
506f1d07
SR
2072 This gives the physical address where the kernel is loaded.
2073
2074 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2075 bzImage will decompress itself to above physical address and
2076 run from there. Otherwise, bzImage will run from the address where
2077 it has been loaded by the boot loader and will ignore above physical
2078 address.
2079
2080 In normal kdump cases one does not have to set/change this option
2081 as now bzImage can be compiled as a completely relocatable image
2082 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2083 address. This option is mainly useful for the folks who don't want
2084 to use a bzImage for capturing the crash dump and want to use a
2085 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2086 to be specifically compiled to run from a specific memory area
2087 (normally a reserved region) and this option comes handy.
2088
ceefccc9
PA
2089 So if you are using bzImage for capturing the crash dump,
2090 leave the value here unchanged to 0x1000000 and set
2091 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2092 for capturing the crash dump change this value to start of
2093 the reserved region. In other words, it can be set based on
2094 the "X" value as specified in the "crashkernel=YM@XM"
2095 command line boot parameter passed to the panic-ed
330d4810 2096 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
ceefccc9 2097 for more details about crash dumps.
506f1d07
SR
2098
2099 Usage of bzImage for capturing the crash dump is recommended as
2100 one does not have to build two kernels. Same kernel can be used
2101 as production kernel and capture kernel. Above option should have
2102 gone away after relocatable bzImage support is introduced. But it
2103 is present because there are users out there who continue to use
2104 vmlinux for dump capture. This option should go away down the
2105 line.
2106
2107 Don't change this unless you know what you are doing.
2108
2109config RELOCATABLE
26717808
PA
2110 bool "Build a relocatable kernel"
2111 default y
8f9ca475 2112 ---help---
506f1d07
SR
2113 This builds a kernel image that retains relocation information
2114 so it can be loaded someplace besides the default 1MB.
2115 The relocations tend to make the kernel binary about 10% larger,
2116 but are discarded at runtime.
2117
2118 One use is for the kexec on panic case where the recovery kernel
2119 must live at a different physical address than the primary
2120 kernel.
2121
2122 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2123 it has been loaded at and the compile time physical address
8ab3820f 2124 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2125
8ab3820f 2126config RANDOMIZE_BASE
e8581e3d 2127 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2128 depends on RELOCATABLE
6807c846 2129 default y
8ab3820f 2130 ---help---
e8581e3d
BH
2131 In support of Kernel Address Space Layout Randomization (KASLR),
2132 this randomizes the physical address at which the kernel image
2133 is decompressed and the virtual address where the kernel
2134 image is mapped, as a security feature that deters exploit
2135 attempts relying on knowledge of the location of kernel
2136 code internals.
2137
ed9f007e
KC
2138 On 64-bit, the kernel physical and virtual addresses are
2139 randomized separately. The physical address will be anywhere
2140 between 16MB and the top of physical memory (up to 64TB). The
2141 virtual address will be randomized from 16MB up to 1GB (9 bits
2142 of entropy). Note that this also reduces the memory space
2143 available to kernel modules from 1.5GB to 1GB.
2144
2145 On 32-bit, the kernel physical and virtual addresses are
2146 randomized together. They will be randomized from 16MB up to
2147 512MB (8 bits of entropy).
e8581e3d
BH
2148
2149 Entropy is generated using the RDRAND instruction if it is
2150 supported. If RDTSC is supported, its value is mixed into
2151 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2152 supported, then entropy is read from the i8254 timer. The
2153 usable entropy is limited by the kernel being built using
2154 2GB addressing, and that PHYSICAL_ALIGN must be at a
2155 minimum of 2MB. As a result, only 10 bits of entropy are
2156 theoretically possible, but the implementations are further
2157 limited due to memory layouts.
e8581e3d 2158
6807c846 2159 If unsure, say Y.
8ab3820f
KC
2160
2161# Relocation on x86 needs some additional build support
845adf72
PA
2162config X86_NEED_RELOCS
2163 def_bool y
8ab3820f 2164 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2165
506f1d07 2166config PHYSICAL_ALIGN
a0215061 2167 hex "Alignment value to which kernel should be aligned"
8ab3820f 2168 default "0x200000"
a0215061
KC
2169 range 0x2000 0x1000000 if X86_32
2170 range 0x200000 0x1000000 if X86_64
8f9ca475 2171 ---help---
506f1d07
SR
2172 This value puts the alignment restrictions on physical address
2173 where kernel is loaded and run from. Kernel is compiled for an
2174 address which meets above alignment restriction.
2175
2176 If bootloader loads the kernel at a non-aligned address and
2177 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2178 address aligned to above value and run from there.
2179
2180 If bootloader loads the kernel at a non-aligned address and
2181 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2182 load address and decompress itself to the address it has been
2183 compiled for and run from there. The address for which kernel is
2184 compiled already meets above alignment restrictions. Hence the
2185 end result is that kernel runs from a physical address meeting
2186 above alignment restrictions.
2187
a0215061
KC
2188 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2189 this value must be a multiple of 0x200000.
2190
506f1d07
SR
2191 Don't change this unless you know what you are doing.
2192
eedb92ab
KS
2193config DYNAMIC_MEMORY_LAYOUT
2194 bool
2195 ---help---
2196 This option makes base addresses of vmalloc and vmemmap as well as
2197 __PAGE_OFFSET movable during boot.
2198
0483e1fa
TG
2199config RANDOMIZE_MEMORY
2200 bool "Randomize the kernel memory sections"
2201 depends on X86_64
2202 depends on RANDOMIZE_BASE
eedb92ab 2203 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2204 default RANDOMIZE_BASE
2205 ---help---
2206 Randomizes the base virtual address of kernel memory sections
2207 (physical memory mapping, vmalloc & vmemmap). This security feature
2208 makes exploits relying on predictable memory locations less reliable.
2209
2210 The order of allocations remains unchanged. Entropy is generated in
2211 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2212 configuration have in average 30,000 different possible virtual
2213 addresses for each memory section.
2214
6807c846 2215 If unsure, say Y.
0483e1fa 2216
90397a41
TG
2217config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2218 hex "Physical memory mapping padding" if EXPERT
2219 depends on RANDOMIZE_MEMORY
2220 default "0xa" if MEMORY_HOTPLUG
2221 default "0x0"
2222 range 0x1 0x40 if MEMORY_HOTPLUG
2223 range 0x0 0x40
2224 ---help---
2225 Define the padding in terabytes added to the existing physical
2226 memory size during kernel memory randomization. It is useful
2227 for memory hotplug support but reduces the entropy available for
2228 address randomization.
2229
2230 If unsure, leave at the default value.
2231
506f1d07 2232config HOTPLUG_CPU
bebd024e 2233 def_bool y
40b31360 2234 depends on SMP
506f1d07 2235
80aa1dff
FY
2236config BOOTPARAM_HOTPLUG_CPU0
2237 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2238 depends on HOTPLUG_CPU
80aa1dff
FY
2239 ---help---
2240 Set whether default state of cpu0_hotpluggable is on or off.
2241
2242 Say Y here to enable CPU0 hotplug by default. If this switch
2243 is turned on, there is no need to give cpu0_hotplug kernel
2244 parameter and the CPU0 hotplug feature is enabled by default.
2245
2246 Please note: there are two known CPU0 dependencies if you want
2247 to enable the CPU0 hotplug feature either by this switch or by
2248 cpu0_hotplug kernel parameter.
2249
2250 First, resume from hibernate or suspend always starts from CPU0.
2251 So hibernate and suspend are prevented if CPU0 is offline.
2252
2253 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2254 offline if any interrupt can not migrate out of CPU0. There may
2255 be other CPU0 dependencies.
2256
2257 Please make sure the dependencies are under your control before
2258 you enable this feature.
2259
2260 Say N if you don't want to enable CPU0 hotplug feature by default.
2261 You still can enable the CPU0 hotplug feature at boot by kernel
2262 parameter cpu0_hotplug.
2263
a71c8bc5
FY
2264config DEBUG_HOTPLUG_CPU0
2265 def_bool n
2266 prompt "Debug CPU0 hotplug"
2c922cd0 2267 depends on HOTPLUG_CPU
a71c8bc5
FY
2268 ---help---
2269 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2270 soon as possible and boots up userspace with CPU0 offlined. User
2271 can online CPU0 back after boot time.
2272
2273 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2274 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2275 compilation or giving cpu0_hotplug kernel parameter at boot.
2276
2277 If unsure, say N.
2278
506f1d07 2279config COMPAT_VDSO
b0b49f26
AL
2280 def_bool n
2281 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2282 depends on COMPAT_32
8f9ca475 2283 ---help---
b0b49f26
AL
2284 Certain buggy versions of glibc will crash if they are
2285 presented with a 32-bit vDSO that is not mapped at the address
2286 indicated in its segment table.
e84446de 2287
b0b49f26
AL
2288 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2289 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2290 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2291 the only released version with the bug, but OpenSUSE 9
2292 contains a buggy "glibc 2.3.2".
506f1d07 2293
b0b49f26
AL
2294 The symptom of the bug is that everything crashes on startup, saying:
2295 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2296
2297 Saying Y here changes the default value of the vdso32 boot
2298 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2299 This works around the glibc bug but hurts performance.
2300
2301 If unsure, say N: if you are compiling your own kernel, you
2302 are unlikely to be using a buggy version of glibc.
506f1d07 2303
3dc33bd3
KC
2304choice
2305 prompt "vsyscall table for legacy applications"
2306 depends on X86_64
625b7b7f 2307 default LEGACY_VSYSCALL_XONLY
3dc33bd3
KC
2308 help
2309 Legacy user code that does not know how to find the vDSO expects
2310 to be able to issue three syscalls by calling fixed addresses in
2311 kernel space. Since this location is not randomized with ASLR,
2312 it can be used to assist security vulnerability exploitation.
2313
2314 This setting can be changed at boot time via the kernel command
bd49e16e 2315 line parameter vsyscall=[emulate|xonly|none].
3dc33bd3
KC
2316
2317 On a system with recent enough glibc (2.14 or newer) and no
2318 static binaries, you can say None without a performance penalty
2319 to improve security.
2320
bd49e16e 2321 If unsure, select "Emulate execution only".
3dc33bd3 2322
3dc33bd3 2323 config LEGACY_VSYSCALL_EMULATE
bd49e16e 2324 bool "Full emulation"
3dc33bd3 2325 help
bd49e16e
AL
2326 The kernel traps and emulates calls into the fixed vsyscall
2327 address mapping. This makes the mapping non-executable, but
2328 it still contains readable known contents, which could be
2329 used in certain rare security vulnerability exploits. This
2330 configuration is recommended when using legacy userspace
2331 that still uses vsyscalls along with legacy binary
2332 instrumentation tools that require code to be readable.
2333
2334 An example of this type of legacy userspace is running
2335 Pin on an old binary that still uses vsyscalls.
2336
2337 config LEGACY_VSYSCALL_XONLY
2338 bool "Emulate execution only"
2339 help
2340 The kernel traps and emulates calls into the fixed vsyscall
2341 address mapping and does not allow reads. This
2342 configuration is recommended when userspace might use the
2343 legacy vsyscall area but support for legacy binary
2344 instrumentation of legacy code is not needed. It mitigates
2345 certain uses of the vsyscall area as an ASLR-bypassing
2346 buffer.
3dc33bd3
KC
2347
2348 config LEGACY_VSYSCALL_NONE
2349 bool "None"
2350 help
2351 There will be no vsyscall mapping at all. This will
2352 eliminate any risk of ASLR bypass due to the vsyscall
2353 fixed address mapping. Attempts to use the vsyscalls
2354 will be reported to dmesg, so that either old or
2355 malicious userspace programs can be identified.
2356
2357endchoice
2358
516cbf37
TB
2359config CMDLINE_BOOL
2360 bool "Built-in kernel command line"
8f9ca475 2361 ---help---
516cbf37
TB
2362 Allow for specifying boot arguments to the kernel at
2363 build time. On some systems (e.g. embedded ones), it is
2364 necessary or convenient to provide some or all of the
2365 kernel boot arguments with the kernel itself (that is,
2366 to not rely on the boot loader to provide them.)
2367
2368 To compile command line arguments into the kernel,
2369 set this option to 'Y', then fill in the
69711ca1 2370 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2371
2372 Systems with fully functional boot loaders (i.e. non-embedded)
2373 should leave this option set to 'N'.
2374
2375config CMDLINE
2376 string "Built-in kernel command string"
2377 depends on CMDLINE_BOOL
2378 default ""
8f9ca475 2379 ---help---
516cbf37
TB
2380 Enter arguments here that should be compiled into the kernel
2381 image and used at boot time. If the boot loader provides a
2382 command line at boot time, it is appended to this string to
2383 form the full kernel command line, when the system boots.
2384
2385 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2386 change this behavior.
2387
2388 In most cases, the command line (whether built-in or provided
2389 by the boot loader) should specify the device for the root
2390 file system.
2391
2392config CMDLINE_OVERRIDE
2393 bool "Built-in command line overrides boot loader arguments"
516cbf37 2394 depends on CMDLINE_BOOL
8f9ca475 2395 ---help---
516cbf37
TB
2396 Set this option to 'Y' to have the kernel ignore the boot loader
2397 command line, and use ONLY the built-in command line.
2398
2399 This is used to work around broken boot loaders. This should
2400 be set to 'N' under normal conditions.
2401
a5b9e5a2
AL
2402config MODIFY_LDT_SYSCALL
2403 bool "Enable the LDT (local descriptor table)" if EXPERT
2404 default y
2405 ---help---
2406 Linux can allow user programs to install a per-process x86
2407 Local Descriptor Table (LDT) using the modify_ldt(2) system
2408 call. This is required to run 16-bit or segmented code such as
2409 DOSEMU or some Wine programs. It is also used by some very old
2410 threading libraries.
2411
2412 Enabling this feature adds a small amount of overhead to
2413 context switches and increases the low-level kernel attack
2414 surface. Disabling it removes the modify_ldt(2) system call.
2415
2416 Saying 'N' here may make sense for embedded or server kernels.
2417
b700e7f0
SJ
2418source "kernel/livepatch/Kconfig"
2419
506f1d07
SR
2420endmenu
2421
3072e413
MH
2422config ARCH_HAS_ADD_PAGES
2423 def_bool y
2424 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2425
506f1d07
SR
2426config ARCH_ENABLE_MEMORY_HOTPLUG
2427 def_bool y
2428 depends on X86_64 || (X86_32 && HIGHMEM)
2429
35551053
GH
2430config ARCH_ENABLE_MEMORY_HOTREMOVE
2431 def_bool y
2432 depends on MEMORY_HOTPLUG
2433
e534c7c5 2434config USE_PERCPU_NUMA_NODE_ID
645a7919 2435 def_bool y
e534c7c5
LS
2436 depends on NUMA
2437
9491846f
KS
2438config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2439 def_bool y
2440 depends on X86_64 || X86_PAE
2441
c177c81e
NH
2442config ARCH_ENABLE_HUGEPAGE_MIGRATION
2443 def_bool y
2444 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2445
9c670ea3
NH
2446config ARCH_ENABLE_THP_MIGRATION
2447 def_bool y
2448 depends on X86_64 && TRANSPARENT_HUGEPAGE
2449
da85f865 2450menu "Power management and ACPI options"
e279b6c1
SR
2451
2452config ARCH_HIBERNATION_HEADER
3c2362e6 2453 def_bool y
44556530 2454 depends on HIBERNATION
e279b6c1
SR
2455
2456source "kernel/power/Kconfig"
2457
2458source "drivers/acpi/Kconfig"
2459
efafc8b2
FT
2460source "drivers/sfi/Kconfig"
2461
a6b68076 2462config X86_APM_BOOT
6fc108a0 2463 def_bool y
282e5aab 2464 depends on APM
a6b68076 2465
e279b6c1
SR
2466menuconfig APM
2467 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2468 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2469 ---help---
2470 APM is a BIOS specification for saving power using several different
2471 techniques. This is mostly useful for battery powered laptops with
2472 APM compliant BIOSes. If you say Y here, the system time will be
2473 reset after a RESUME operation, the /proc/apm device will provide
2474 battery status information, and user-space programs will receive
2475 notification of APM "events" (e.g. battery status change).
2476
2477 If you select "Y" here, you can disable actual use of the APM
2478 BIOS by passing the "apm=off" option to the kernel at boot time.
2479
2480 Note that the APM support is almost completely disabled for
2481 machines with more than one CPU.
2482
2483 In order to use APM, you will need supporting software. For location
151f4e2b 2484 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2485 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2486 <http://www.tldp.org/docs.html#howto>.
2487
2488 This driver does not spin down disk drives (see the hdparm(8)
2489 manpage ("man 8 hdparm") for that), and it doesn't turn off
2490 VESA-compliant "green" monitors.
2491
2492 This driver does not support the TI 4000M TravelMate and the ACER
2493 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2494 desktop machines also don't have compliant BIOSes, and this driver
2495 may cause those machines to panic during the boot phase.
2496
2497 Generally, if you don't have a battery in your machine, there isn't
2498 much point in using this driver and you should say N. If you get
2499 random kernel OOPSes or reboots that don't seem to be related to
2500 anything, try disabling/enabling this option (or disabling/enabling
2501 APM in your BIOS).
2502
2503 Some other things you should try when experiencing seemingly random,
2504 "weird" problems:
2505
2506 1) make sure that you have enough swap space and that it is
2507 enabled.
2508 2) pass the "no-hlt" option to the kernel
2509 3) switch on floating point emulation in the kernel and pass
2510 the "no387" option to the kernel
2511 4) pass the "floppy=nodma" option to the kernel
2512 5) pass the "mem=4M" option to the kernel (thereby disabling
2513 all but the first 4 MB of RAM)
2514 6) make sure that the CPU is not over clocked.
2515 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2516 8) disable the cache from your BIOS settings
2517 9) install a fan for the video card or exchange video RAM
2518 10) install a better fan for the CPU
2519 11) exchange RAM chips
2520 12) exchange the motherboard.
2521
2522 To compile this driver as a module, choose M here: the
2523 module will be called apm.
2524
2525if APM
2526
2527config APM_IGNORE_USER_SUSPEND
2528 bool "Ignore USER SUSPEND"
8f9ca475 2529 ---help---
e279b6c1
SR
2530 This option will ignore USER SUSPEND requests. On machines with a
2531 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2532 series notebooks, it is necessary to say Y because of a BIOS bug.
2533
2534config APM_DO_ENABLE
2535 bool "Enable PM at boot time"
2536 ---help---
2537 Enable APM features at boot time. From page 36 of the APM BIOS
2538 specification: "When disabled, the APM BIOS does not automatically
2539 power manage devices, enter the Standby State, enter the Suspend
2540 State, or take power saving steps in response to CPU Idle calls."
2541 This driver will make CPU Idle calls when Linux is idle (unless this
2542 feature is turned off -- see "Do CPU IDLE calls", below). This
2543 should always save battery power, but more complicated APM features
2544 will be dependent on your BIOS implementation. You may need to turn
2545 this option off if your computer hangs at boot time when using APM
2546 support, or if it beeps continuously instead of suspending. Turn
2547 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2548 T400CDT. This is off by default since most machines do fine without
2549 this feature.
2550
2551config APM_CPU_IDLE
dd8af076 2552 depends on CPU_IDLE
e279b6c1 2553 bool "Make CPU Idle calls when idle"
8f9ca475 2554 ---help---
e279b6c1
SR
2555 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2556 On some machines, this can activate improved power savings, such as
2557 a slowed CPU clock rate, when the machine is idle. These idle calls
2558 are made after the idle loop has run for some length of time (e.g.,
2559 333 mS). On some machines, this will cause a hang at boot time or
2560 whenever the CPU becomes idle. (On machines with more than one CPU,
2561 this option does nothing.)
2562
2563config APM_DISPLAY_BLANK
2564 bool "Enable console blanking using APM"
8f9ca475 2565 ---help---
e279b6c1
SR
2566 Enable console blanking using the APM. Some laptops can use this to
2567 turn off the LCD backlight when the screen blanker of the Linux
2568 virtual console blanks the screen. Note that this is only used by
2569 the virtual console screen blanker, and won't turn off the backlight
2570 when using the X Window system. This also doesn't have anything to
2571 do with your VESA-compliant power-saving monitor. Further, this
2572 option doesn't work for all laptops -- it might not turn off your
2573 backlight at all, or it might print a lot of errors to the console,
2574 especially if you are using gpm.
2575
2576config APM_ALLOW_INTS
2577 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2578 ---help---
e279b6c1
SR
2579 Normally we disable external interrupts while we are making calls to
2580 the APM BIOS as a measure to lessen the effects of a badly behaving
2581 BIOS implementation. The BIOS should reenable interrupts if it
2582 needs to. Unfortunately, some BIOSes do not -- especially those in
2583 many of the newer IBM Thinkpads. If you experience hangs when you
2584 suspend, try setting this to Y. Otherwise, say N.
2585
e279b6c1
SR
2586endif # APM
2587
bb0a56ec 2588source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2589
2590source "drivers/cpuidle/Kconfig"
2591
27471fdb
AH
2592source "drivers/idle/Kconfig"
2593
e279b6c1
SR
2594endmenu
2595
2596
2597menu "Bus options (PCI etc.)"
2598
e279b6c1
SR
2599choice
2600 prompt "PCI access mode"
efefa6f6 2601 depends on X86_32 && PCI
e279b6c1
SR
2602 default PCI_GOANY
2603 ---help---
2604 On PCI systems, the BIOS can be used to detect the PCI devices and
2605 determine their configuration. However, some old PCI motherboards
2606 have BIOS bugs and may crash if this is done. Also, some embedded
2607 PCI-based systems don't have any BIOS at all. Linux can also try to
2608 detect the PCI hardware directly without using the BIOS.
2609
2610 With this option, you can specify how Linux should detect the
2611 PCI devices. If you choose "BIOS", the BIOS will be used,
2612 if you choose "Direct", the BIOS won't be used, and if you
2613 choose "MMConfig", then PCI Express MMCONFIG will be used.
2614 If you choose "Any", the kernel will try MMCONFIG, then the
2615 direct access method and falls back to the BIOS if that doesn't
2616 work. If unsure, go with the default, which is "Any".
2617
2618config PCI_GOBIOS
2619 bool "BIOS"
2620
2621config PCI_GOMMCONFIG
2622 bool "MMConfig"
2623
2624config PCI_GODIRECT
2625 bool "Direct"
2626
3ef0e1f8 2627config PCI_GOOLPC
76fb6570 2628 bool "OLPC XO-1"
3ef0e1f8
AS
2629 depends on OLPC
2630
2bdd1b03
AS
2631config PCI_GOANY
2632 bool "Any"
2633
e279b6c1
SR
2634endchoice
2635
2636config PCI_BIOS
3c2362e6 2637 def_bool y
efefa6f6 2638 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2639
2640# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2641config PCI_DIRECT
3c2362e6 2642 def_bool y
0aba496f 2643 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2644
2645config PCI_MMCONFIG
b45c9f36
JK
2646 bool "Support mmconfig PCI config space access" if X86_64
2647 default y
8364e1f8 2648 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2649 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2650
3ef0e1f8 2651config PCI_OLPC
2bdd1b03
AS
2652 def_bool y
2653 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2654
b5401a96
AN
2655config PCI_XEN
2656 def_bool y
2657 depends on PCI && XEN
2658 select SWIOTLB_XEN
2659
8364e1f8
JK
2660config MMCONF_FAM10H
2661 def_bool y
2662 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2663
3f6ea84a 2664config PCI_CNB20LE_QUIRK
6a108a14 2665 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2666 depends on PCI
3f6ea84a
IS
2667 help
2668 Read the PCI windows out of the CNB20LE host bridge. This allows
2669 PCI hotplug to work on systems with the CNB20LE chipset which do
2670 not have ACPI.
2671
64a5fed6
BH
2672 There's no public spec for this chipset, and this functionality
2673 is known to be incomplete.
2674
2675 You should say N unless you know you need this.
2676
3a495511 2677config ISA_BUS
17a2a129 2678 bool "ISA bus support on modern systems" if EXPERT
3a495511 2679 help
17a2a129
WBG
2680 Expose ISA bus device drivers and options available for selection and
2681 configuration. Enable this option if your target machine has an ISA
2682 bus. ISA is an older system, displaced by PCI and newer bus
2683 architectures -- if your target machine is modern, it probably does
2684 not have an ISA bus.
3a495511
WBG
2685
2686 If unsure, say N.
2687
1c00f016 2688# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2689config ISA_DMA_API
1c00f016
DR
2690 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2691 default y
2692 help
2693 Enables ISA-style DMA support for devices requiring such controllers.
2694 If unsure, say Y.
e279b6c1 2695
51e68d05
LT
2696if X86_32
2697
e279b6c1
SR
2698config ISA
2699 bool "ISA support"
8f9ca475 2700 ---help---
e279b6c1
SR
2701 Find out whether you have ISA slots on your motherboard. ISA is the
2702 name of a bus system, i.e. the way the CPU talks to the other stuff
2703 inside your box. Other bus systems are PCI, EISA, MicroChannel
2704 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2705 newer boards don't support it. If you have ISA, say Y, otherwise N.
2706
e279b6c1
SR
2707config SCx200
2708 tristate "NatSemi SCx200 support"
8f9ca475 2709 ---help---
e279b6c1
SR
2710 This provides basic support for National Semiconductor's
2711 (now AMD's) Geode processors. The driver probes for the
2712 PCI-IDs of several on-chip devices, so its a good dependency
2713 for other scx200_* drivers.
2714
2715 If compiled as a module, the driver is named scx200.
2716
2717config SCx200HR_TIMER
2718 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2719 depends on SCx200
e279b6c1 2720 default y
8f9ca475 2721 ---help---
e279b6c1
SR
2722 This driver provides a clocksource built upon the on-chip
2723 27MHz high-resolution timer. Its also a workaround for
2724 NSC Geode SC-1100's buggy TSC, which loses time when the
2725 processor goes idle (as is done by the scheduler). The
2726 other workaround is idle=poll boot option.
2727
3ef0e1f8
AS
2728config OLPC
2729 bool "One Laptop Per Child support"
54008979 2730 depends on !X86_PAE
3c554946 2731 select GPIOLIB
dc3119e7 2732 select OF
45bb1674 2733 select OF_PROMTREE
b4e51854 2734 select IRQ_DOMAIN
0c3d931b 2735 select OLPC_EC
8f9ca475 2736 ---help---
3ef0e1f8
AS
2737 Add support for detecting the unique features of the OLPC
2738 XO hardware.
2739
a3128588
DD
2740config OLPC_XO1_PM
2741 bool "OLPC XO-1 Power Management"
fa112cf1 2742 depends on OLPC && MFD_CS5535=y && PM_SLEEP
bf1ebf00 2743 ---help---
97c4cb71 2744 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2745
cfee9597
DD
2746config OLPC_XO1_RTC
2747 bool "OLPC XO-1 Real Time Clock"
2748 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2749 ---help---
2750 Add support for the XO-1 real time clock, which can be used as a
2751 programmable wakeup source.
2752
7feda8e9
DD
2753config OLPC_XO1_SCI
2754 bool "OLPC XO-1 SCI extras"
92e830f2 2755 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2756 depends on INPUT=y
d8d01a63 2757 select POWER_SUPPLY
7feda8e9
DD
2758 ---help---
2759 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2760 - EC-driven system wakeups
7feda8e9 2761 - Power button
7bc74b3d 2762 - Ebook switch
2cf2baea 2763 - Lid switch
e1040ac6
DD
2764 - AC adapter status updates
2765 - Battery status updates
7feda8e9 2766
a0f30f59
DD
2767config OLPC_XO15_SCI
2768 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2769 depends on OLPC && ACPI
2770 select POWER_SUPPLY
a0f30f59
DD
2771 ---help---
2772 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2773 - EC-driven system wakeups
2774 - AC adapter status updates
2775 - Battery status updates
bf1ebf00 2776
d4f3e350
EW
2777config ALIX
2778 bool "PCEngines ALIX System Support (LED setup)"
2779 select GPIOLIB
2780 ---help---
2781 This option enables system support for the PCEngines ALIX.
2782 At present this just sets up LEDs for GPIO control on
2783 ALIX2/3/6 boards. However, other system specific setup should
2784 get added here.
2785
2786 Note: You must still enable the drivers for GPIO and LED support
2787 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2788
2789 Note: You have to set alix.force=1 for boards with Award BIOS.
2790
da4e3302
PP
2791config NET5501
2792 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2793 select GPIOLIB
2794 ---help---
2795 This option enables system support for the Soekris Engineering net5501.
2796
3197059a
PP
2797config GEOS
2798 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2799 select GPIOLIB
2800 depends on DMI
2801 ---help---
2802 This option enables system support for the Traverse Technologies GEOS.
2803
7d029125
VD
2804config TS5500
2805 bool "Technologic Systems TS-5500 platform support"
2806 depends on MELAN
2807 select CHECK_SIGNATURE
2808 select NEW_LEDS
2809 select LEDS_CLASS
2810 ---help---
2811 This option enables system support for the Technologic Systems TS-5500.
2812
bc0120fd
SR
2813endif # X86_32
2814
23ac4ae8 2815config AMD_NB
e279b6c1 2816 def_bool y
0e152cd7 2817 depends on CPU_SUP_AMD && PCI
e279b6c1 2818
e3263ab3
DR
2819config X86_SYSFB
2820 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2821 help
2822 Firmwares often provide initial graphics framebuffers so the BIOS,
2823 bootloader or kernel can show basic video-output during boot for
2824 user-guidance and debugging. Historically, x86 used the VESA BIOS
2825 Extensions and EFI-framebuffers for this, which are mostly limited
2826 to x86.
2827 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2828 framebuffers so the new generic system-framebuffer drivers can be
2829 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2830 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DR
2831 drivers like efifb, vesafb and uvesafb can pick it up.
2832 If this option is not selected, all system framebuffers are always
2833 marked as fallback platform framebuffers as usual.
2834
2835 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2836 not be able to pick up generic system framebuffers if this option
2837 is selected. You are highly encouraged to enable simplefb as
2838 replacement if you select this option. simplefb can correctly deal
2839 with generic system framebuffers. But you should still keep vesafb
2840 and others enabled as fallback if a system framebuffer is
2841 incompatible with simplefb.
2842
2843 If unsure, say Y.
2844
e279b6c1
SR
2845endmenu
2846
2847
1572497c 2848menu "Binary Emulations"
e279b6c1
SR
2849
2850config IA32_EMULATION
2851 bool "IA32 Emulation"
2852 depends on X86_64
39f88911 2853 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2854 select BINFMT_ELF
a97f52e6 2855 select COMPAT_BINFMT_ELF
39f88911 2856 select COMPAT_OLD_SIGACTION
8f9ca475 2857 ---help---
5fd92e65
L
2858 Include code to run legacy 32-bit programs under a
2859 64-bit kernel. You should likely turn this on, unless you're
2860 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2861
2862config IA32_AOUT
8f9ca475
IM
2863 tristate "IA32 a.out support"
2864 depends on IA32_EMULATION
eac61655 2865 depends on BROKEN
8f9ca475
IM
2866 ---help---
2867 Support old a.out binaries in the 32bit emulation.
e279b6c1 2868
0bf62763 2869config X86_X32
6ea30386 2870 bool "x32 ABI for 64-bit mode"
9b54050b 2871 depends on X86_64
5fd92e65
L
2872 ---help---
2873 Include code to run binaries for the x32 native 32-bit ABI
2874 for 64-bit processors. An x32 process gets access to the
2875 full 64-bit register file and wide data path while leaving
2876 pointers at 32 bits for smaller memory footprint.
2877
2878 You will need a recent binutils (2.22 or later) with
2879 elf32_x86_64 support enabled to compile a kernel with this
2880 option set.
2881
953fee1d
IM
2882config COMPAT_32
2883 def_bool y
2884 depends on IA32_EMULATION || X86_32
2885 select HAVE_UID16
2886 select OLD_SIGSUSPEND3
2887
e279b6c1 2888config COMPAT
3c2362e6 2889 def_bool y
0bf62763 2890 depends on IA32_EMULATION || X86_X32
e279b6c1 2891
3120e25e 2892if COMPAT
e279b6c1 2893config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2894 def_bool y
e279b6c1
SR
2895
2896config SYSVIPC_COMPAT
3c2362e6 2897 def_bool y
3120e25e 2898 depends on SYSVIPC
3120e25e 2899endif
ee009e4a 2900
e279b6c1
SR
2901endmenu
2902
2903
e5beae16
KP
2904config HAVE_ATOMIC_IOMAP
2905 def_bool y
2906 depends on X86_32
2907
4692d77f
AR
2908config X86_DEV_DMA_OPS
2909 bool
f7219a53 2910
e279b6c1
SR
2911source "drivers/firmware/Kconfig"
2912
edf88417 2913source "arch/x86/kvm/Kconfig"