x86/vdso: Provide vdso_data offset on vvar_page
[linux-block.git] / arch / x86 / Kconfig
CommitLineData
b2441318 1# SPDX-License-Identifier: GPL-2.0
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2# Select 32 or 64 bit
3config 64BIT
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MY
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
8f9ca475 6 ---help---
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7 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
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11 def_bool y
12 depends on !64BIT
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13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
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
c12d3362 27 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
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IM
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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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
0c9c1d56 71 select ARCH_HAS_MEM_ENCRYPT
10bcc80e 72 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 73 select ARCH_HAS_PMEM_API if X86_64
17596731 74 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 75 select ARCH_HAS_PTE_SPECIAL
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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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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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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104 select EDAC_ATOMIC_SCRUB
105 select EDAC_SUPPORT
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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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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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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
0609ae01 137 select HAVE_ARCH_KASAN_VMALLOC if X86_64
6471b825 138 select HAVE_ARCH_KGDB
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139 select HAVE_ARCH_MMAP_RND_BITS if MMU
140 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 141 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 142 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 143 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 144 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 145 select HAVE_ARCH_STACKLEAK
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146 select HAVE_ARCH_TRACEHOOK
147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 149 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 150 select HAVE_ARCH_WITHIN_STACK_FRAMES
2ff2b7ec 151 select HAVE_ASM_MODVERSIONS
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152 select HAVE_CMPXCHG_DOUBLE
153 select HAVE_CMPXCHG_LOCAL
154 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 155 select HAVE_COPY_THREAD_TLS
cf4db259 156 select HAVE_C_RECORDMCOUNT
6471b825 157 select HAVE_DEBUG_KMEMLEAK
6471b825 158 select HAVE_DMA_CONTIGUOUS
677aa9f7 159 select HAVE_DYNAMIC_FTRACE
06aeaaea 160 select HAVE_DYNAMIC_FTRACE_WITH_REGS
562955fe 161 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
03f5781b 162 select HAVE_EBPF_JIT
58340a07 163 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 164 select HAVE_EISA
5f56a5df 165 select HAVE_EXIT_THREAD
67a929e0 166 select HAVE_FAST_GUP
644e0e8d 167 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 168 select HAVE_FTRACE_MCOUNT_RECORD
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169 select HAVE_FUNCTION_GRAPH_TRACER
170 select HAVE_FUNCTION_TRACER
6b90bd4b 171 select HAVE_GCC_PLUGINS
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172 select HAVE_HW_BREAKPOINT
173 select HAVE_IDE
174 select HAVE_IOREMAP_PROT
175 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
176 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 177 select HAVE_KERNEL_BZIP2
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178 select HAVE_KERNEL_GZIP
179 select HAVE_KERNEL_LZ4
2e9f3bdd 180 select HAVE_KERNEL_LZMA
13510997 181 select HAVE_KERNEL_LZO
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182 select HAVE_KERNEL_XZ
183 select HAVE_KPROBES
184 select HAVE_KPROBES_ON_FTRACE
540adea3 185 select HAVE_FUNCTION_ERROR_INJECTION
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186 select HAVE_KRETPROBES
187 select HAVE_KVM
188 select HAVE_LIVEPATCH if X86_64
6471b825 189 select HAVE_MEMBLOCK_NODE_MAP
0102752e 190 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 191 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 192 select HAVE_MOVE_PMD
42a0bb3f 193 select HAVE_NMI
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194 select HAVE_OPROFILE
195 select HAVE_OPTPROBES
196 select HAVE_PCSPKR_PLATFORM
197 select HAVE_PERF_EVENTS
c01d4323 198 select HAVE_PERF_EVENTS_NMI
92e5aae4 199 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 200 select HAVE_PCI
c5e63197 201 select HAVE_PERF_REGS
c5ebcedb 202 select HAVE_PERF_USER_STACK_DUMP
48a8b97c 203 select HAVE_RCU_TABLE_FREE if PARAVIRT
6471b825 204 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 205 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 206 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 207 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 208 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 209 select HAVE_RSEQ
6471b825 210 select HAVE_SYSCALL_TRACEPOINTS
6471b825 211 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 212 select HAVE_USER_RETURN_NOTIFIER
7ac87074 213 select HAVE_GENERIC_VDSO
05736e4a 214 select HOTPLUG_SMT if SMP
c0185808 215 select IRQ_FORCED_THREADING
86596f0a 216 select NEED_SG_DMA_LENGTH
2eac9c2d 217 select PCI_DOMAINS if PCI
625210cf 218 select PCI_LOCKLESS_CONFIG if PCI
6471b825 219 select PERF_EVENTS
3195ef59 220 select RTC_LIB
d6faca40 221 select RTC_MC146818_LIB
6471b825 222 select SPARSE_IRQ
83fe27ea 223 select SRCU
6471b825 224 select SYSCTL_EXCEPTION_TRACE
15f4eae7 225 select THREAD_INFO_IN_TASK
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226 select USER_STACKTRACE_SUPPORT
227 select VIRT_TO_BUS
6471b825 228 select X86_FEATURE_NAMES if PROC_FS
0c608dad 229 select PROC_PID_ARCH_STATUS if PROC_FS
7d8330a5 230
ba7e4d13 231config INSTRUCTION_DECODER
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232 def_bool y
233 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 234
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235config OUTPUT_FORMAT
236 string
237 default "elf32-i386" if X86_32
238 default "elf64-x86-64" if X86_64
239
73531905 240config ARCH_DEFCONFIG
b9b39bfb 241 string
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SR
242 default "arch/x86/configs/i386_defconfig" if X86_32
243 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 244
8d5fffb9 245config LOCKDEP_SUPPORT
3c2362e6 246 def_bool y
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SR
247
248config STACKTRACE_SUPPORT
3c2362e6 249 def_bool y
8d5fffb9 250
8d5fffb9 251config MMU
3c2362e6 252 def_bool y
8d5fffb9 253
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254config ARCH_MMAP_RND_BITS_MIN
255 default 28 if 64BIT
256 default 8
257
258config ARCH_MMAP_RND_BITS_MAX
259 default 32 if 64BIT
260 default 16
261
262config ARCH_MMAP_RND_COMPAT_BITS_MIN
263 default 8
264
265config ARCH_MMAP_RND_COMPAT_BITS_MAX
266 default 16
267
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268config SBUS
269 bool
270
271config GENERIC_ISA_DMA
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272 def_bool y
273 depends on ISA_DMA_API
8d5fffb9 274
8d5fffb9 275config GENERIC_BUG
3c2362e6 276 def_bool y
8d5fffb9 277 depends on BUG
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278 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
279
280config GENERIC_BUG_RELATIVE_POINTERS
281 bool
8d5fffb9 282
8d5fffb9 283config ARCH_MAY_HAVE_PC_FDC
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284 def_bool y
285 depends on ISA_DMA_API
8d5fffb9 286
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287config GENERIC_CALIBRATE_DELAY
288 def_bool y
289
9a0b8415 290config ARCH_HAS_CPU_RELAX
291 def_bool y
292
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293config ARCH_HAS_CACHE_LINE_SIZE
294 def_bool y
295
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296config ARCH_HAS_FILTER_PGPROT
297 def_bool y
298
dd5af90a 299config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 300 def_bool y
b32ef636 301
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302config NEED_PER_CPU_EMBED_FIRST_CHUNK
303 def_bool y
304
305config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
306 def_bool y
307
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308config ARCH_HIBERNATION_POSSIBLE
309 def_bool y
801e4062 310
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311config ARCH_SUSPEND_POSSIBLE
312 def_bool y
f4cb5700 313
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SC
314config ARCH_WANT_GENERAL_HUGETLB
315 def_bool y
316
8d5fffb9 317config ZONE_DMA32
e0fd24a3 318 def_bool y if X86_64
8d5fffb9 319
8d5fffb9 320config AUDIT_ARCH
e0fd24a3 321 def_bool y if X86_64
8d5fffb9 322
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323config ARCH_SUPPORTS_DEBUG_PAGEALLOC
324 def_bool y
325
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326config KASAN_SHADOW_OFFSET
327 hex
328 depends on KASAN
329 default 0xdffffc0000000000
330
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331config HAVE_INTEL_TXT
332 def_bool y
6ea30386 333 depends on INTEL_IOMMU && ACPI
69575d38 334
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335config X86_32_SMP
336 def_bool y
337 depends on X86_32 && SMP
338
339config X86_64_SMP
340 def_bool y
341 depends on X86_64 && SMP
342
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TH
343config X86_32_LAZY_GS
344 def_bool y
8458f8c2 345 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 346
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SD
347config ARCH_SUPPORTS_UPROBES
348 def_bool y
349
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350config FIX_EARLYCON_MEM
351 def_bool y
352
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353config DYNAMIC_PHYSICAL_MASK
354 bool
355
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356config PGTABLE_LEVELS
357 int
77ef56e4 358 default 5 if X86_5LEVEL
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359 default 4 if X86_64
360 default 3 if X86_PAE
361 default 2
362
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363config CC_HAS_SANE_STACKPROTECTOR
364 bool
365 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
366 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
367 help
368 We have to make sure stack protector is unconditionally disabled if
369 the compiler produces broken code.
370
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SR
371menu "Processor type and features"
372
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373config ZONE_DMA
374 bool "DMA memory allocation support" if EXPERT
375 default y
376 help
377 DMA memory allocation support allows devices with less than 32-bit
378 addressing to allocate within the first 16MB of address space.
379 Disable if no such devices will be used.
380
381 If unsure, say Y.
382
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383config SMP
384 bool "Symmetric multi-processing support"
385 ---help---
386 This enables support for systems with more than one CPU. If you have
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387 a system with only one CPU, say N. If you have a system with more
388 than one CPU, say Y.
506f1d07 389
4a474157 390 If you say N here, the kernel will run on uni- and multiprocessor
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SR
391 machines, but will use only one CPU of a multiprocessor machine. If
392 you say Y here, the kernel will run on many, but not all,
4a474157 393 uniprocessor machines. On a uniprocessor machine, the kernel
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SR
394 will run faster if you say N here.
395
396 Note that if you say Y here and choose architecture "586" or
397 "Pentium" under "Processor family", the kernel will not work on 486
398 architectures. Similarly, multiprocessor kernels for the "PPro"
399 architecture may not work on all Pentium based boards.
400
401 People using multiprocessor machines who say Y here should also say
402 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
403 Management" code will be disabled if you say Y here.
404
cb1aaebe 405 See also <file:Documentation/x86/i386/IO-APIC.rst>,
4f4cfa6c 406 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
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SR
407 <http://www.tldp.org/docs.html#howto>.
408
409 If you don't know what to do here, say N.
410
9def39be
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411config X86_FEATURE_NAMES
412 bool "Processor feature human-readable names" if EMBEDDED
413 default y
414 ---help---
415 This option compiles in a table of x86 feature bits and corresponding
416 names. This is required to support /proc/cpuinfo and a few kernel
417 messages. You can disable this to save space, at the expense of
418 making those few kernel messages show numeric feature bits instead.
419
420 If in doubt, say Y.
421
06cd9a7d
YL
422config X86_X2APIC
423 bool "Support x2apic"
19e3d60d 424 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
425 ---help---
426 This enables x2apic support on CPUs that have this feature.
427
428 This allows 32-bit apic IDs (so it can support very large systems),
429 and accesses the local apic via MSRs not via mmio.
430
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YL
431 If you don't know what to do here, say N.
432
6695c85b 433config X86_MPPARSE
6e87f9b7 434 bool "Enable MPS table" if ACPI || SFI
7a527688 435 default y
5ab74722 436 depends on X86_LOCAL_APIC
8f9ca475 437 ---help---
6695c85b
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438 For old smp systems that do not have proper acpi support. Newer systems
439 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 440
ddd70cf9
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441config GOLDFISH
442 def_bool y
443 depends on X86_GOLDFISH
444
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DW
445config RETPOLINE
446 bool "Avoid speculative indirect branches in kernel"
447 default y
d5028ba8 448 select STACK_VALIDATION if HAVE_STACK_VALIDATION
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DW
449 help
450 Compile kernel with the retpoline compiler options to guard against
451 kernel-to-user data leaks by avoiding speculative indirect
452 branches. Requires a compiler with -mindirect-branch=thunk-extern
453 support for full protection. The kernel may run slower.
454
e6d42931
JW
455config X86_CPU_RESCTRL
456 bool "x86 CPU resource control support"
6fe07ce3 457 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 458 select KERNFS
78e99b4a 459 help
e6d42931 460 Enable x86 CPU resource control support.
6fe07ce3
BM
461
462 Provide support for the allocation and monitoring of system resources
463 usage by the CPU.
464
465 Intel calls this Intel Resource Director Technology
466 (Intel(R) RDT). More information about RDT can be found in the
467 Intel x86 Architecture Software Developer Manual.
468
469 AMD calls this AMD Platform Quality of Service (AMD QoS).
470 More information about AMD QoS can be found in the AMD64 Technology
471 Platform Quality of Service Extensions manual.
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472
473 Say N if unsure.
474
8425091f 475if X86_32
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RD
476config X86_BIGSMP
477 bool "Support for big SMP systems with more than 8 CPUs"
478 depends on SMP
479 ---help---
480 This option is needed for the systems that have more than 8 CPUs
481
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482config X86_EXTENDED_PLATFORM
483 bool "Support for extended (non-PC) x86 platforms"
484 default y
8f9ca475 485 ---help---
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486 If you disable this option then the kernel will only support
487 standard PC platforms. (which covers the vast majority of
488 systems out there.)
489
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490 If you enable this option then you'll be able to select support
491 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 492 Goldfish (Android emulator)
8425091f 493 AMD Elan
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RT
494 RDC R-321x SoC
495 SGI 320/540 (Visual Workstation)
83125a3a 496 STA2X11-based (e.g. Northville)
3f4110a4 497 Moorestown MID devices
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498
499 If you have one of these systems, or if you want to build a
500 generic distribution kernel, say Y here - otherwise say N.
8425091f 501endif
06ac8346 502
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RT
503if X86_64
504config X86_EXTENDED_PLATFORM
505 bool "Support for extended (non-PC) x86 platforms"
506 default y
507 ---help---
508 If you disable this option then the kernel will only support
509 standard PC platforms. (which covers the vast majority of
510 systems out there.)
511
512 If you enable this option then you'll be able to select support
513 for the following (non-PC) 64 bit x86 platforms:
44b111b5 514 Numascale NumaChip
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RT
515 ScaleMP vSMP
516 SGI Ultraviolet
517
518 If you have one of these systems, or if you want to build a
519 generic distribution kernel, say Y here - otherwise say N.
520endif
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RT
521# This is an alphabetically sorted list of 64 bit extended platforms
522# Please maintain the alphabetic order if and when there are additions
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SP
523config X86_NUMACHIP
524 bool "Numascale NumaChip"
525 depends on X86_64
526 depends on X86_EXTENDED_PLATFORM
527 depends on NUMA
528 depends on SMP
529 depends on X86_X2APIC
f9726bfd 530 depends on PCI_MMCONFIG
44b111b5
SP
531 ---help---
532 Adds support for Numascale NumaChip large-SMP systems. Needed to
533 enable more than ~168 cores.
534 If you don't have one of these, you should say N here.
506f1d07 535
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RT
536config X86_VSMP
537 bool "ScaleMP vSMP"
6276a074 538 select HYPERVISOR_GUEST
c5c606d9
RT
539 select PARAVIRT
540 depends on X86_64 && PCI
541 depends on X86_EXTENDED_PLATFORM
ead91d4b 542 depends on SMP
8f9ca475 543 ---help---
c5c606d9
RT
544 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
545 supposed to run on these EM64T-based machines. Only choose this option
546 if you have one of these machines.
5e3a77e9 547
03b48632
NP
548config X86_UV
549 bool "SGI Ultraviolet"
550 depends on X86_64
c5c606d9 551 depends on X86_EXTENDED_PLATFORM
54c28d29 552 depends on NUMA
1ecb4ae5 553 depends on EFI
9d6c26e7 554 depends on X86_X2APIC
1222e564 555 depends on PCI
8f9ca475 556 ---help---
03b48632
NP
557 This option is needed in order to support SGI Ultraviolet systems.
558 If you don't have one of these, you should say N here.
559
c5c606d9
RT
560# Following is an alphabetically sorted list of 32 bit extended platforms
561# Please maintain the alphabetic order if and when there are additions
506f1d07 562
ddd70cf9
JN
563config X86_GOLDFISH
564 bool "Goldfish (Virtual Platform)"
cb7b8023 565 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
566 ---help---
567 Enable support for the Goldfish virtual platform used primarily
568 for Android development. Unless you are building for the Android
569 Goldfish emulator say N here.
570
c751e17b
TG
571config X86_INTEL_CE
572 bool "CE4100 TV platform"
573 depends on PCI
574 depends on PCI_GODIRECT
6084a6e2 575 depends on X86_IO_APIC
c751e17b
TG
576 depends on X86_32
577 depends on X86_EXTENDED_PLATFORM
37bc9f50 578 select X86_REBOOTFIXUPS
da6b737b
SAS
579 select OF
580 select OF_EARLY_FLATTREE
c751e17b
TG
581 ---help---
582 Select for the Intel CE media processor (CE4100) SOC.
583 This option compiles in support for the CE4100 SOC for settop
584 boxes and media devices.
585
4cb9b00f 586config X86_INTEL_MID
43605ef1 587 bool "Intel MID platform support"
43605ef1 588 depends on X86_EXTENDED_PLATFORM
edc6bc78 589 depends on X86_PLATFORM_DEVICES
1ea7c673 590 depends on PCI
3fda5bb4 591 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 592 depends on X86_IO_APIC
7c9c3a1e 593 select SFI
4cb9b00f 594 select I2C
7c9c3a1e 595 select DW_APB_TIMER
1ea7c673 596 select APB_TIMER
1ea7c673 597 select INTEL_SCU_IPC
15a713df 598 select MFD_INTEL_MSIC
1ea7c673 599 ---help---
4cb9b00f
DC
600 Select to build a kernel capable of supporting Intel MID (Mobile
601 Internet Device) platform systems which do not have the PCI legacy
602 interfaces. If you are building for a PC class system say N here.
1ea7c673 603
4cb9b00f
DC
604 Intel MID platforms are based on an Intel processor and chipset which
605 consume less power than most of the x86 derivatives.
43605ef1 606
8bbc2a13
BD
607config X86_INTEL_QUARK
608 bool "Intel Quark platform support"
609 depends on X86_32
610 depends on X86_EXTENDED_PLATFORM
611 depends on X86_PLATFORM_DEVICES
612 depends on X86_TSC
613 depends on PCI
614 depends on PCI_GOANY
615 depends on X86_IO_APIC
616 select IOSF_MBI
617 select INTEL_IMR
9ab6eb51 618 select COMMON_CLK
8bbc2a13
BD
619 ---help---
620 Select to include support for Quark X1000 SoC.
621 Say Y here if you have a Quark based system such as the Arduino
622 compatible Intel Galileo.
623
3d48aab1
MW
624config X86_INTEL_LPSS
625 bool "Intel Low Power Subsystem Support"
5962dd22 626 depends on X86 && ACPI && PCI
3d48aab1 627 select COMMON_CLK
0f531431 628 select PINCTRL
eebb3e8d 629 select IOSF_MBI
3d48aab1
MW
630 ---help---
631 Select to build support for Intel Low Power Subsystem such as
632 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
633 things like clock tree (common clock framework) and pincontrol
634 which are needed by the LPSS peripheral drivers.
3d48aab1 635
92082a88
KX
636config X86_AMD_PLATFORM_DEVICE
637 bool "AMD ACPI2Platform devices support"
638 depends on ACPI
639 select COMMON_CLK
640 select PINCTRL
641 ---help---
642 Select to interpret AMD specific ACPI device to platform device
643 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
644 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
645 implemented under PINCTRL subsystem.
646
ced3ce76
DB
647config IOSF_MBI
648 tristate "Intel SoC IOSF Sideband support for SoC platforms"
649 depends on PCI
650 ---help---
651 This option enables sideband register access support for Intel SoC
652 platforms. On these platforms the IOSF sideband is used in lieu of
653 MSR's for some register accesses, mostly but not limited to thermal
654 and power. Drivers may query the availability of this device to
655 determine if they need the sideband in order to work on these
656 platforms. The sideband is available on the following SoC products.
657 This list is not meant to be exclusive.
658 - BayTrail
659 - Braswell
660 - Quark
661
662 You should say Y if you are running a kernel on one of these SoC's.
663
ed2226bd
DB
664config IOSF_MBI_DEBUG
665 bool "Enable IOSF sideband access through debugfs"
666 depends on IOSF_MBI && DEBUG_FS
667 ---help---
668 Select this option to expose the IOSF sideband access registers (MCR,
669 MDR, MCRX) through debugfs to write and read register information from
670 different units on the SoC. This is most useful for obtaining device
671 state information for debug and analysis. As this is a general access
672 mechanism, users of this option would have specific knowledge of the
673 device they want to access.
674
675 If you don't require the option or are in doubt, say N.
676
c5c606d9
RT
677config X86_RDC321X
678 bool "RDC R-321x SoC"
506f1d07 679 depends on X86_32
c5c606d9
RT
680 depends on X86_EXTENDED_PLATFORM
681 select M486
682 select X86_REBOOTFIXUPS
683 ---help---
684 This option is needed for RDC R-321x system-on-chip, also known
685 as R-8610-(G).
686 If you don't have one of these chips, you should say N here.
687
e0c7ae37 688config X86_32_NON_STANDARD
9c398017
IM
689 bool "Support non-standard 32-bit SMP architectures"
690 depends on X86_32 && SMP
c5c606d9 691 depends on X86_EXTENDED_PLATFORM
8f9ca475 692 ---help---
b5660ba7
PA
693 This option compiles in the bigsmp and STA2X11 default
694 subarchitectures. It is intended for a generic binary
695 kernel. If you select them all, kernel will probe it one by
696 one and will fallback to default.
d49c4288 697
c5c606d9 698# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 699
d949f36f 700config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 701 def_bool y
d949f36f
LT
702 # MCE code calls memory_failure():
703 depends on X86_MCE
704 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
705 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
706 depends on X86_64 || !SPARSEMEM
707 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 708
83125a3a
AR
709config STA2X11
710 bool "STA2X11 Companion Chip Support"
711 depends on X86_32_NON_STANDARD && PCI
83125a3a
AR
712 select SWIOTLB
713 select MFD_STA2X11
0145071b 714 select GPIOLIB
83125a3a
AR
715 ---help---
716 This adds support for boards based on the STA2X11 IO-Hub,
717 a.k.a. "ConneXt". The chip is used in place of the standard
718 PC chipset, so all "standard" peripherals are missing. If this
719 option is selected the kernel will still be able to boot on
720 standard PC machines.
721
82148d1d
S
722config X86_32_IRIS
723 tristate "Eurobraille/Iris poweroff module"
724 depends on X86_32
725 ---help---
726 The Iris machines from EuroBraille do not have APM or ACPI support
727 to shut themselves down properly. A special I/O sequence is
728 needed to do so, which is what this module does at
729 kernel shutdown.
730
731 This is only for Iris machines from EuroBraille.
732
733 If unused, say N.
734
ae1e9130 735config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
736 def_bool y
737 prompt "Single-depth WCHAN output"
a87d0914 738 depends on X86
8f9ca475 739 ---help---
506f1d07
SR
740 Calculate simpler /proc/<PID>/wchan values. If this option
741 is disabled then wchan values will recurse back to the
742 caller function. This provides more accurate wchan values,
743 at the expense of slightly more scheduling overhead.
744
745 If in doubt, say "Y".
746
6276a074
BP
747menuconfig HYPERVISOR_GUEST
748 bool "Linux guest support"
8f9ca475 749 ---help---
6276a074
BP
750 Say Y here to enable options for running Linux under various hyper-
751 visors. This option enables basic hypervisor detection and platform
752 setup.
506f1d07 753
6276a074
BP
754 If you say N, all options in this submenu will be skipped and
755 disabled, and Linux guest support won't be built in.
506f1d07 756
6276a074 757if HYPERVISOR_GUEST
506f1d07 758
e61bd94a
EPH
759config PARAVIRT
760 bool "Enable paravirtualization code"
8f9ca475 761 ---help---
e61bd94a
EPH
762 This changes the kernel so it can modify itself when it is run
763 under a hypervisor, potentially improving performance significantly
764 over full virtualization. However, when run without a hypervisor
765 the kernel is theoretically slower and slightly larger.
766
c00a280a
JG
767config PARAVIRT_XXL
768 bool
769
6276a074
BP
770config PARAVIRT_DEBUG
771 bool "paravirt-ops debugging"
772 depends on PARAVIRT && DEBUG_KERNEL
773 ---help---
774 Enable to debug paravirt_ops internals. Specifically, BUG if
775 a paravirt_op is missing when it is called.
776
b4ecc126
JF
777config PARAVIRT_SPINLOCKS
778 bool "Paravirtualization layer for spinlocks"
6ea30386 779 depends on PARAVIRT && SMP
b4ecc126
JF
780 ---help---
781 Paravirtualized spinlocks allow a pvops backend to replace the
782 spinlock implementation with something virtualization-friendly
783 (for example, block the virtual CPU rather than spinning).
784
4c4e4f61
R
785 It has a minimal impact on native kernels and gives a nice performance
786 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 787
4c4e4f61 788 If you are unsure how to answer this question, answer Y.
b4ecc126 789
ecca2502
ZY
790config X86_HV_CALLBACK_VECTOR
791 def_bool n
792
6276a074 793source "arch/x86/xen/Kconfig"
7af192c9 794
6276a074
BP
795config KVM_GUEST
796 bool "KVM Guest support (including kvmclock)"
797 depends on PARAVIRT
798 select PARAVIRT_CLOCK
a1c4423b 799 select ARCH_CPUIDLE_HALTPOLL
6276a074 800 default y
8f9ca475 801 ---help---
6276a074
BP
802 This option enables various optimizations for running under the KVM
803 hypervisor. It includes a paravirtualized clock, so that instead
804 of relying on a PIT (or probably other) emulation by the
805 underlying device model, the host provides the guest with
806 timing infrastructure such as time of day, and system time
506f1d07 807
a1c4423b
MT
808config ARCH_CPUIDLE_HALTPOLL
809 def_bool n
810 prompt "Disable host haltpoll when loading haltpoll driver"
811 help
812 If virtualized under KVM, disable host haltpoll.
813
7733607f
MW
814config PVH
815 bool "Support for running PVH guests"
816 ---help---
817 This option enables the PVH entry point for guest virtual machines
818 as specified in the x86/HVM direct boot ABI.
819
1e20eb85
SV
820config KVM_DEBUG_FS
821 bool "Enable debug information for KVM Guests in debugfs"
822 depends on KVM_GUEST && DEBUG_FS
1e20eb85
SV
823 ---help---
824 This option enables collection of various statistics for KVM guest.
825 Statistics are displayed in debugfs filesystem. Enabling this option
826 may incur significant overhead.
827
6276a074
BP
828config PARAVIRT_TIME_ACCOUNTING
829 bool "Paravirtual steal time accounting"
830 depends on PARAVIRT
8f9ca475 831 ---help---
6276a074
BP
832 Select this option to enable fine granularity task steal time
833 accounting. Time spent executing other tasks in parallel with
834 the current vCPU is discounted from the vCPU power. To account for
835 that, there can be a small performance impact.
836
837 If in doubt, say N here.
838
839config PARAVIRT_CLOCK
840 bool
97349135 841
4a362601
JK
842config JAILHOUSE_GUEST
843 bool "Jailhouse non-root cell support"
abde587b 844 depends on X86_64 && PCI
87e65d05 845 select X86_PM_TIMER
4a362601
JK
846 ---help---
847 This option allows to run Linux as guest in a Jailhouse non-root
848 cell. You can leave this option disabled if you only want to start
849 Jailhouse and run Linux afterwards in the root cell.
850
ec7972c9
ZY
851config ACRN_GUEST
852 bool "ACRN Guest support"
853 depends on X86_64
498ad393 854 select X86_HV_CALLBACK_VECTOR
ec7972c9
ZY
855 help
856 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
857 a flexible, lightweight reference open-source hypervisor, built with
858 real-time and safety-criticality in mind. It is built for embedded
859 IOT with small footprint and real-time features. More details can be
860 found in https://projectacrn.org/.
861
6276a074 862endif #HYPERVISOR_GUEST
97349135 863
506f1d07
SR
864source "arch/x86/Kconfig.cpu"
865
866config HPET_TIMER
3c2362e6 867 def_bool X86_64
506f1d07 868 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
869 ---help---
870 Use the IA-PC HPET (High Precision Event Timer) to manage
871 time in preference to the PIT and RTC, if a HPET is
872 present.
873 HPET is the next generation timer replacing legacy 8254s.
874 The HPET provides a stable time base on SMP
875 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
876 as it is off-chip. The interface used is documented
877 in the HPET spec, revision 1.
506f1d07 878
8f9ca475
IM
879 You can safely choose Y here. However, HPET will only be
880 activated if the platform and the BIOS support this feature.
881 Otherwise the 8254 will be used for timing services.
506f1d07 882
8f9ca475 883 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
884
885config HPET_EMULATE_RTC
3c2362e6 886 def_bool y
9d8af78b 887 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 888
bb24c471 889config APB_TIMER
933b9463
AC
890 def_bool y if X86_INTEL_MID
891 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 892 select DW_APB_TIMER
a0c3832a 893 depends on X86_INTEL_MID && SFI
bb24c471
JP
894 help
895 APB timer is the replacement for 8254, HPET on X86 MID platforms.
896 The APBT provides a stable time base on SMP
897 systems, unlike the TSC, but it is more expensive to access,
898 as it is off-chip. APB timers are always running regardless of CPU
899 C states, they are used as per CPU clockevent device when possible.
900
6a108a14 901# Mark as expert because too many people got it wrong.
506f1d07 902# The code disables itself when not needed.
7ae9392c
TP
903config DMI
904 default y
cf074402 905 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 906 bool "Enable DMI scanning" if EXPERT
8f9ca475 907 ---help---
7ae9392c
TP
908 Enabled scanning of DMI to identify machine quirks. Say Y
909 here unless you have verified that your setup is not
910 affected by entries in the DMI blacklist. Required by PNP
911 BIOS code.
912
506f1d07 913config GART_IOMMU
38901f1c 914 bool "Old AMD GART IOMMU support"
a4ce5a48 915 select IOMMU_HELPER
506f1d07 916 select SWIOTLB
23ac4ae8 917 depends on X86_64 && PCI && AMD_NB
8f9ca475 918 ---help---
ced3c42c
IM
919 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
920 GART based hardware IOMMUs.
921
922 The GART supports full DMA access for devices with 32-bit access
923 limitations, on systems with more than 3 GB. This is usually needed
924 for USB, sound, many IDE/SATA chipsets and some other devices.
925
926 Newer systems typically have a modern AMD IOMMU, supported via
927 the CONFIG_AMD_IOMMU=y config option.
928
929 In normal configurations this driver is only active when needed:
930 there's more than 3 GB of memory and the system contains a
931 32-bit limited device.
932
933 If unsure, say Y.
506f1d07 934
1184dc2f 935config MAXSMP
ddb0c5a6 936 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 937 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 938 select CPUMASK_OFFSTACK
8f9ca475 939 ---help---
ddb0c5a6 940 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 941 If unsure, say N.
506f1d07 942
aec6487e
IM
943#
944# The maximum number of CPUs supported:
945#
946# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
947# and which can be configured interactively in the
948# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
949#
950# The ranges are different on 32-bit and 64-bit kernels, depending on
951# hardware capabilities and scalability features of the kernel.
952#
953# ( If MAXSMP is enabled we just use the highest possible value and disable
954# interactive configuration. )
955#
956
957config NR_CPUS_RANGE_BEGIN
a0d0bb4d 958 int
aec6487e
IM
959 default NR_CPUS_RANGE_END if MAXSMP
960 default 1 if !SMP
961 default 2
a0d0bb4d 962
aec6487e 963config NR_CPUS_RANGE_END
a0d0bb4d 964 int
aec6487e
IM
965 depends on X86_32
966 default 64 if SMP && X86_BIGSMP
967 default 8 if SMP && !X86_BIGSMP
968 default 1 if !SMP
a0d0bb4d 969
aec6487e 970config NR_CPUS_RANGE_END
a0d0bb4d 971 int
aec6487e 972 depends on X86_64
1edae1ae
SW
973 default 8192 if SMP && CPUMASK_OFFSTACK
974 default 512 if SMP && !CPUMASK_OFFSTACK
aec6487e 975 default 1 if !SMP
a0d0bb4d 976
aec6487e 977config NR_CPUS_DEFAULT
a0d0bb4d
RD
978 int
979 depends on X86_32
aec6487e
IM
980 default 32 if X86_BIGSMP
981 default 8 if SMP
982 default 1 if !SMP
a0d0bb4d 983
aec6487e 984config NR_CPUS_DEFAULT
a0d0bb4d
RD
985 int
986 depends on X86_64
aec6487e
IM
987 default 8192 if MAXSMP
988 default 64 if SMP
989 default 1 if !SMP
a0d0bb4d 990
506f1d07 991config NR_CPUS
36f5101a 992 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
993 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
994 default NR_CPUS_DEFAULT
8f9ca475 995 ---help---
506f1d07 996 This allows you to specify the maximum number of CPUs which this
bb61ccc7 997 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 998 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
999 minimum value which makes sense is 2.
1000
aec6487e
IM
1001 This is purely to save memory: each supported CPU adds about 8KB
1002 to the kernel image.
506f1d07
SR
1003
1004config SCHED_SMT
dbe73364 1005 def_bool y if SMP
506f1d07
SR
1006
1007config SCHED_MC
3c2362e6
HH
1008 def_bool y
1009 prompt "Multi-core scheduler support"
c8e56d20 1010 depends on SMP
8f9ca475 1011 ---help---
506f1d07
SR
1012 Multi-core scheduler support improves the CPU scheduler's decision
1013 making when dealing with multi-core CPU chips at a cost of slightly
1014 increased overhead in some places. If unsure say N here.
1015
de966cf4
TC
1016config SCHED_MC_PRIO
1017 bool "CPU core priorities scheduler support"
0a21fc12
IM
1018 depends on SCHED_MC && CPU_SUP_INTEL
1019 select X86_INTEL_PSTATE
1020 select CPU_FREQ
de966cf4 1021 default y
5e76b2ab 1022 ---help---
0a21fc12
IM
1023 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1024 core ordering determined at manufacturing time, which allows
1025 certain cores to reach higher turbo frequencies (when running
1026 single threaded workloads) than others.
de966cf4 1027
0a21fc12
IM
1028 Enabling this kernel feature teaches the scheduler about
1029 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1030 scheduler's CPU selection logic accordingly, so that higher
1031 overall system performance can be achieved.
de966cf4 1032
0a21fc12 1033 This feature will have no effect on CPUs without this feature.
de966cf4 1034
0a21fc12 1035 If unsure say Y here.
5e76b2ab 1036
30b8b006
TG
1037config UP_LATE_INIT
1038 def_bool y
ba360f88 1039 depends on !SMP && X86_LOCAL_APIC
30b8b006 1040
506f1d07 1041config X86_UP_APIC
50849eef
JB
1042 bool "Local APIC support on uniprocessors" if !PCI_MSI
1043 default PCI_MSI
38a1dfda 1044 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1045 ---help---
506f1d07
SR
1046 A local APIC (Advanced Programmable Interrupt Controller) is an
1047 integrated interrupt controller in the CPU. If you have a single-CPU
1048 system which has a processor with a local APIC, you can say Y here to
1049 enable and use it. If you say Y here even though your machine doesn't
1050 have a local APIC, then the kernel will still run with no slowdown at
1051 all. The local APIC supports CPU-generated self-interrupts (timer,
1052 performance counters), and the NMI watchdog which detects hard
1053 lockups.
1054
1055config X86_UP_IOAPIC
1056 bool "IO-APIC support on uniprocessors"
1057 depends on X86_UP_APIC
8f9ca475 1058 ---help---
506f1d07
SR
1059 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1060 SMP-capable replacement for PC-style interrupt controllers. Most
1061 SMP systems and many recent uniprocessor systems have one.
1062
1063 If you have a single-CPU system with an IO-APIC, you can say Y here
1064 to use it. If you say Y here even though your machine doesn't have
1065 an IO-APIC, then the kernel will still run with no slowdown at all.
1066
1067config X86_LOCAL_APIC
3c2362e6 1068 def_bool y
0dbc6078 1069 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1070 select IRQ_DOMAIN_HIERARCHY
52f518a3 1071 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1072
1073config X86_IO_APIC
b1da1e71
JB
1074 def_bool y
1075 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1076
41b9eb26
SA
1077config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1078 bool "Reroute for broken boot IRQs"
41b9eb26 1079 depends on X86_IO_APIC
8f9ca475 1080 ---help---
41b9eb26
SA
1081 This option enables a workaround that fixes a source of
1082 spurious interrupts. This is recommended when threaded
1083 interrupt handling is used on systems where the generation of
1084 superfluous "boot interrupts" cannot be disabled.
1085
1086 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1087 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1088 kernel does during interrupt handling). On chipsets where this
1089 boot IRQ generation cannot be disabled, this workaround keeps
1090 the original IRQ line masked so that only the equivalent "boot
1091 IRQ" is delivered to the CPUs. The workaround also tells the
1092 kernel to set up the IRQ handler on the boot IRQ line. In this
1093 way only one interrupt is delivered to the kernel. Otherwise
1094 the spurious second interrupt may cause the kernel to bring
1095 down (vital) interrupt lines.
1096
1097 Only affects "broken" chipsets. Interrupt sharing may be
1098 increased on these systems.
1099
506f1d07 1100config X86_MCE
bab9bc65 1101 bool "Machine Check / overheating reporting"
648ed940 1102 select GENERIC_ALLOCATOR
e57dbaf7 1103 default y
506f1d07 1104 ---help---
bab9bc65
AK
1105 Machine Check support allows the processor to notify the
1106 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1107 The action the kernel takes depends on the severity of the problem,
bab9bc65 1108 ranging from warning messages to halting the machine.
4efc0670 1109
5de97c9f
TL
1110config X86_MCELOG_LEGACY
1111 bool "Support for deprecated /dev/mcelog character device"
1112 depends on X86_MCE
1113 ---help---
1114 Enable support for /dev/mcelog which is needed by the old mcelog
1115 userspace logging daemon. Consider switching to the new generation
1116 rasdaemon solution.
1117
506f1d07 1118config X86_MCE_INTEL
3c2362e6
HH
1119 def_bool y
1120 prompt "Intel MCE features"
c1ebf835 1121 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1122 ---help---
506f1d07
SR
1123 Additional support for intel specific MCE features such as
1124 the thermal monitor.
1125
1126config X86_MCE_AMD
3c2362e6
HH
1127 def_bool y
1128 prompt "AMD MCE features"
f5382de9 1129 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1130 ---help---
506f1d07
SR
1131 Additional support for AMD specific MCE features such as
1132 the DRAM Error Threshold.
1133
4efc0670 1134config X86_ANCIENT_MCE
6fc108a0 1135 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1136 depends on X86_32 && X86_MCE
cd13adcc
HS
1137 ---help---
1138 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1139 systems. These typically need to be enabled explicitly on the command
cd13adcc 1140 line.
4efc0670 1141
b2762686
AK
1142config X86_MCE_THRESHOLD
1143 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1144 def_bool y
b2762686 1145
ea149b36 1146config X86_MCE_INJECT
bc8e80d5 1147 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1148 tristate "Machine check injector support"
1149 ---help---
1150 Provide support for injecting machine checks for testing purposes.
1151 If you don't know what a machine check is and you don't do kernel
1152 QA it is safe to say n.
1153
4efc0670
AK
1154config X86_THERMAL_VECTOR
1155 def_bool y
5bb38adc 1156 depends on X86_MCE_INTEL
4efc0670 1157
07dc900e 1158source "arch/x86/events/Kconfig"
e633c65a 1159
5aef51c3 1160config X86_LEGACY_VM86
1e642812 1161 bool "Legacy VM86 support"
506f1d07 1162 depends on X86_32
8f9ca475 1163 ---help---
5aef51c3
AL
1164 This option allows user programs to put the CPU into V8086
1165 mode, which is an 80286-era approximation of 16-bit real mode.
1166
1167 Some very old versions of X and/or vbetool require this option
1168 for user mode setting. Similarly, DOSEMU will use it if
1169 available to accelerate real mode DOS programs. However, any
1170 recent version of DOSEMU, X, or vbetool should be fully
1171 functional even without kernel VM86 support, as they will all
1e642812
IM
1172 fall back to software emulation. Nevertheless, if you are using
1173 a 16-bit DOS program where 16-bit performance matters, vm86
1174 mode might be faster than emulation and you might want to
1175 enable this option.
5aef51c3 1176
1e642812
IM
1177 Note that any app that works on a 64-bit kernel is unlikely to
1178 need this option, as 64-bit kernels don't, and can't, support
1179 V8086 mode. This option is also unrelated to 16-bit protected
1180 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1181
1e642812
IM
1182 Enabling this option increases the complexity of the kernel
1183 and slows down exception handling a tiny bit.
5aef51c3 1184
1e642812 1185 If unsure, say N here.
5aef51c3
AL
1186
1187config VM86
1188 bool
1189 default X86_LEGACY_VM86
34273f41
PA
1190
1191config X86_16BIT
1192 bool "Enable support for 16-bit segments" if EXPERT
1193 default y
a5b9e5a2 1194 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1195 ---help---
1196 This option is required by programs like Wine to run 16-bit
1197 protected mode legacy code on x86 processors. Disabling
1198 this option saves about 300 bytes on i386, or around 6K text
1199 plus 16K runtime memory on x86-64,
1200
1201config X86_ESPFIX32
1202 def_bool y
1203 depends on X86_16BIT && X86_32
506f1d07 1204
197725de
PA
1205config X86_ESPFIX64
1206 def_bool y
34273f41 1207 depends on X86_16BIT && X86_64
506f1d07 1208
1ad83c85
AL
1209config X86_VSYSCALL_EMULATION
1210 bool "Enable vsyscall emulation" if EXPERT
1211 default y
1212 depends on X86_64
1213 ---help---
1214 This enables emulation of the legacy vsyscall page. Disabling
1215 it is roughly equivalent to booting with vsyscall=none, except
1216 that it will also disable the helpful warning if a program
1217 tries to use a vsyscall. With this option set to N, offending
1218 programs will just segfault, citing addresses of the form
1219 0xffffffffff600?00.
1220
1221 This option is required by many programs built before 2013, and
1222 care should be used even with newer programs if set to N.
1223
1224 Disabling this option saves about 7K of kernel size and
1225 possibly 4K of additional runtime pagetable memory.
1226
111e7b15
TG
1227config X86_IOPL_IOPERM
1228 bool "IOPERM and IOPL Emulation"
a24ca997 1229 default y
c8137ace 1230 ---help---
111e7b15
TG
1231 This enables the ioperm() and iopl() syscalls which are necessary
1232 for legacy applications.
1233
c8137ace
TG
1234 Legacy IOPL support is an overbroad mechanism which allows user
1235 space aside of accessing all 65536 I/O ports also to disable
1236 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1237 capabilities and permission from potentially active security
1238 modules.
1239
1240 The emulation restricts the functionality of the syscall to
1241 only allowing the full range I/O port access, but prevents the
a24ca997
TG
1242 ability to disable interrupts from user space which would be
1243 granted if the hardware IOPL mechanism would be used.
c8137ace 1244
506f1d07
SR
1245config TOSHIBA
1246 tristate "Toshiba Laptop support"
1247 depends on X86_32
1248 ---help---
1249 This adds a driver to safely access the System Management Mode of
1250 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1251 not work on models with a Phoenix BIOS. The System Management Mode
1252 is used to set the BIOS and power saving options on Toshiba portables.
1253
1254 For information on utilities to make use of this driver see the
1255 Toshiba Linux utilities web site at:
1256 <http://www.buzzard.org.uk/toshiba/>.
1257
1258 Say Y if you intend to run this kernel on a Toshiba portable.
1259 Say N otherwise.
1260
1261config I8K
039ae585 1262 tristate "Dell i8k legacy laptop support"
949a9d70 1263 select HWMON
039ae585 1264 select SENSORS_DELL_SMM
506f1d07 1265 ---help---
039ae585
PR
1266 This option enables legacy /proc/i8k userspace interface in hwmon
1267 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1268 temperature and allows controlling fan speeds of Dell laptops via
1269 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1270 it reports also power and hotkey status. For fan speed control is
1271 needed userspace package i8kutils.
1272
1273 Say Y if you intend to run this kernel on old Dell laptops or want to
1274 use userspace package i8kutils.
506f1d07
SR
1275 Say N otherwise.
1276
1277config X86_REBOOTFIXUPS
9ba16087
JB
1278 bool "Enable X86 board specific fixups for reboot"
1279 depends on X86_32
506f1d07
SR
1280 ---help---
1281 This enables chipset and/or board specific fixups to be done
1282 in order to get reboot to work correctly. This is only needed on
1283 some combinations of hardware and BIOS. The symptom, for which
1284 this config is intended, is when reboot ends with a stalled/hung
1285 system.
1286
1287 Currently, the only fixup is for the Geode machines using
5e3a77e9 1288 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1289
1290 Say Y if you want to enable the fixup. Currently, it's safe to
1291 enable this option even if you don't need it.
1292 Say N otherwise.
1293
1294config MICROCODE
9a2bc335
BP
1295 bool "CPU microcode loading support"
1296 default y
80030e3d 1297 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1298 select FW_LOADER
1299 ---help---
1300 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1301 Intel and AMD processors. The Intel support is for the IA32 family,
1302 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1303 AMD support is for families 0x10 and later. You will obviously need
1304 the actual microcode binary data itself which is not shipped with
1305 the Linux kernel.
1306
1307 The preferred method to load microcode from a detached initrd is described
cb1aaebe 1308 in Documentation/x86/microcode.rst. For that you need to enable
5f9c01aa
BP
1309 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1310 initrd for microcode blobs.
1311
c508c46e
BG
1312 In addition, you can build the microcode into the kernel. For that you
1313 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1314 config option.
506f1d07 1315
8d86f390 1316config MICROCODE_INTEL
e43f6e67 1317 bool "Intel microcode loading support"
8f9ca475
IM
1318 depends on MICROCODE
1319 default MICROCODE
1320 select FW_LOADER
1321 ---help---
1322 This options enables microcode patch loading support for Intel
1323 processors.
1324
b8989db9
A
1325 For the current Intel microcode data package go to
1326 <https://downloadcenter.intel.com> and search for
1327 'Linux Processor Microcode Data File'.
8d86f390 1328
80cc9f10 1329config MICROCODE_AMD
e43f6e67 1330 bool "AMD microcode loading support"
8f9ca475
IM
1331 depends on MICROCODE
1332 select FW_LOADER
1333 ---help---
1334 If you select this option, microcode patch loading support for AMD
1335 processors will be enabled.
80cc9f10 1336
8f9ca475 1337config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1338 bool "Ancient loading interface (DEPRECATED)"
1339 default n
506f1d07 1340 depends on MICROCODE
c02f48e0
BP
1341 ---help---
1342 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1343 which was used by userspace tools like iucode_tool and microcode.ctl.
1344 It is inadequate because it runs too late to be able to properly
1345 load microcode on a machine and it needs special tools. Instead, you
1346 should've switched to the early loading method with the initrd or
cb1aaebe 1347 builtin microcode by now: Documentation/x86/microcode.rst
506f1d07
SR
1348
1349config X86_MSR
1350 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1351 ---help---
506f1d07
SR
1352 This device gives privileged processes access to the x86
1353 Model-Specific Registers (MSRs). It is a character device with
1354 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1355 MSR accesses are directed to a specific CPU on multi-processor
1356 systems.
1357
1358config X86_CPUID
1359 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1360 ---help---
506f1d07
SR
1361 This device gives processes access to the x86 CPUID instruction to
1362 be executed on a specific processor. It is a character device
1363 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1364 /dev/cpu/31/cpuid.
1365
1366choice
1367 prompt "High Memory Support"
6fc108a0 1368 default HIGHMEM4G
506f1d07
SR
1369 depends on X86_32
1370
1371config NOHIGHMEM
1372 bool "off"
506f1d07
SR
1373 ---help---
1374 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1375 However, the address space of 32-bit x86 processors is only 4
1376 Gigabytes large. That means that, if you have a large amount of
1377 physical memory, not all of it can be "permanently mapped" by the
1378 kernel. The physical memory that's not permanently mapped is called
1379 "high memory".
1380
1381 If you are compiling a kernel which will never run on a machine with
1382 more than 1 Gigabyte total physical RAM, answer "off" here (default
1383 choice and suitable for most users). This will result in a "3GB/1GB"
1384 split: 3GB are mapped so that each process sees a 3GB virtual memory
1385 space and the remaining part of the 4GB virtual memory space is used
1386 by the kernel to permanently map as much physical memory as
1387 possible.
1388
1389 If the machine has between 1 and 4 Gigabytes physical RAM, then
1390 answer "4GB" here.
1391
1392 If more than 4 Gigabytes is used then answer "64GB" here. This
1393 selection turns Intel PAE (Physical Address Extension) mode on.
1394 PAE implements 3-level paging on IA32 processors. PAE is fully
1395 supported by Linux, PAE mode is implemented on all recent Intel
1396 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1397 then the kernel will not boot on CPUs that don't support PAE!
1398
1399 The actual amount of total physical memory will either be
1400 auto detected or can be forced by using a kernel command line option
1401 such as "mem=256M". (Try "man bootparam" or see the documentation of
1402 your boot loader (lilo or loadlin) about how to pass options to the
1403 kernel at boot time.)
1404
1405 If unsure, say "off".
1406
1407config HIGHMEM4G
1408 bool "4GB"
8f9ca475 1409 ---help---
506f1d07
SR
1410 Select this if you have a 32-bit processor and between 1 and 4
1411 gigabytes of physical RAM.
1412
1413config HIGHMEM64G
1414 bool "64GB"
69b8d3fc 1415 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1416 select X86_PAE
8f9ca475 1417 ---help---
506f1d07
SR
1418 Select this if you have a 32-bit processor and more than 4
1419 gigabytes of physical RAM.
1420
1421endchoice
1422
1423choice
6a108a14 1424 prompt "Memory split" if EXPERT
506f1d07
SR
1425 default VMSPLIT_3G
1426 depends on X86_32
8f9ca475 1427 ---help---
506f1d07
SR
1428 Select the desired split between kernel and user memory.
1429
1430 If the address range available to the kernel is less than the
1431 physical memory installed, the remaining memory will be available
1432 as "high memory". Accessing high memory is a little more costly
1433 than low memory, as it needs to be mapped into the kernel first.
1434 Note that increasing the kernel address space limits the range
1435 available to user programs, making the address space there
1436 tighter. Selecting anything other than the default 3G/1G split
1437 will also likely make your kernel incompatible with binary-only
1438 kernel modules.
1439
1440 If you are not absolutely sure what you are doing, leave this
1441 option alone!
1442
1443 config VMSPLIT_3G
1444 bool "3G/1G user/kernel split"
1445 config VMSPLIT_3G_OPT
1446 depends on !X86_PAE
1447 bool "3G/1G user/kernel split (for full 1G low memory)"
1448 config VMSPLIT_2G
1449 bool "2G/2G user/kernel split"
1450 config VMSPLIT_2G_OPT
1451 depends on !X86_PAE
1452 bool "2G/2G user/kernel split (for full 2G low memory)"
1453 config VMSPLIT_1G
1454 bool "1G/3G user/kernel split"
1455endchoice
1456
1457config PAGE_OFFSET
1458 hex
1459 default 0xB0000000 if VMSPLIT_3G_OPT
1460 default 0x80000000 if VMSPLIT_2G
1461 default 0x78000000 if VMSPLIT_2G_OPT
1462 default 0x40000000 if VMSPLIT_1G
1463 default 0xC0000000
1464 depends on X86_32
1465
1466config HIGHMEM
3c2362e6 1467 def_bool y
506f1d07 1468 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1469
1470config X86_PAE
9ba16087 1471 bool "PAE (Physical Address Extension) Support"
506f1d07 1472 depends on X86_32 && !HIGHMEM4G
d4a451d5 1473 select PHYS_ADDR_T_64BIT
9d99c712 1474 select SWIOTLB
8f9ca475 1475 ---help---
506f1d07
SR
1476 PAE is required for NX support, and furthermore enables
1477 larger swapspace support for non-overcommit purposes. It
1478 has the cost of more pagetable lookup overhead, and also
1479 consumes more pagetable space per process.
1480
77ef56e4
KS
1481config X86_5LEVEL
1482 bool "Enable 5-level page tables support"
18ec1eaf 1483 default y
eedb92ab 1484 select DYNAMIC_MEMORY_LAYOUT
162434e7 1485 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1486 depends on X86_64
1487 ---help---
1488 5-level paging enables access to larger address space:
1489 upto 128 PiB of virtual address space and 4 PiB of
1490 physical address space.
1491
1492 It will be supported by future Intel CPUs.
1493
6657fca0
KS
1494 A kernel with the option enabled can be booted on machines that
1495 support 4- or 5-level paging.
77ef56e4 1496
cb1aaebe 1497 See Documentation/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1498 information.
1499
1500 Say N if unsure.
1501
10971ab2 1502config X86_DIRECT_GBPAGES
e5008abe 1503 def_bool y
2e1da13f 1504 depends on X86_64
8f9ca475 1505 ---help---
10971ab2
IM
1506 Certain kernel features effectively disable kernel
1507 linear 1 GB mappings (even if the CPU otherwise
1508 supports them), so don't confuse the user by printing
1509 that we have them enabled.
9e899816 1510
5c280cf6
TG
1511config X86_CPA_STATISTICS
1512 bool "Enable statistic for Change Page Attribute"
1513 depends on DEBUG_FS
1514 ---help---
1515 Expose statistics about the Change Page Attribute mechanims, which
a943245a 1516 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1517 page mappings when mapping protections are changed.
1518
7744ccdb
TL
1519config AMD_MEM_ENCRYPT
1520 bool "AMD Secure Memory Encryption (SME) support"
1521 depends on X86_64 && CPU_SUP_AMD
94d49eb3 1522 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1523 select ARCH_USE_MEMREMAP_PROT
9087c375 1524 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
7744ccdb
TL
1525 ---help---
1526 Say yes to enable support for the encryption of system memory.
1527 This requires an AMD processor that supports Secure Memory
1528 Encryption (SME).
1529
1530config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1531 bool "Activate AMD Secure Memory Encryption (SME) by default"
1532 default y
1533 depends on AMD_MEM_ENCRYPT
1534 ---help---
1535 Say yes to have system memory encrypted by default if running on
1536 an AMD processor that supports Secure Memory Encryption (SME).
1537
1538 If set to Y, then the encryption of system memory can be
1539 deactivated with the mem_encrypt=off command line option.
1540
1541 If set to N, then the encryption of system memory can be
1542 activated with the mem_encrypt=on command line option.
1543
506f1d07
SR
1544# Common NUMA Features
1545config NUMA
fd51b2d7 1546 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1547 depends on SMP
b5660ba7
PA
1548 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1549 default y if X86_BIGSMP
8f9ca475 1550 ---help---
506f1d07 1551 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1552
506f1d07
SR
1553 The kernel will try to allocate memory used by a CPU on the
1554 local memory controller of the CPU and add some more
1555 NUMA awareness to the kernel.
1556
c280ea5e 1557 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1558 (or later), AMD Opteron, or EM64T NUMA.
1559
b5660ba7 1560 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1561 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1562
1563 Otherwise, you should say N.
506f1d07 1564
eec1d4fa 1565config AMD_NUMA
3c2362e6
HH
1566 def_bool y
1567 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1568 depends on X86_64 && NUMA && PCI
8f9ca475 1569 ---help---
eec1d4fa
HR
1570 Enable AMD NUMA node topology detection. You should say Y here if
1571 you have a multi processor AMD system. This uses an old method to
1572 read the NUMA configuration directly from the builtin Northbridge
1573 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1574 which also takes priority if both are compiled in.
506f1d07
SR
1575
1576config X86_64_ACPI_NUMA
3c2362e6
HH
1577 def_bool y
1578 prompt "ACPI NUMA detection"
506f1d07
SR
1579 depends on X86_64 && NUMA && ACPI && PCI
1580 select ACPI_NUMA
8f9ca475 1581 ---help---
506f1d07
SR
1582 Enable ACPI SRAT based node topology detection.
1583
6ec6e0d9
SS
1584# Some NUMA nodes have memory ranges that span
1585# other nodes. Even though a pfn is valid and
1586# between a node's start and end pfns, it may not
1587# reside on that node. See memmap_init_zone()
1588# for details.
1589config NODES_SPAN_OTHER_NODES
1590 def_bool y
1591 depends on X86_64_ACPI_NUMA
1592
506f1d07
SR
1593config NUMA_EMU
1594 bool "NUMA emulation"
1b7e03ef 1595 depends on NUMA
8f9ca475 1596 ---help---
506f1d07
SR
1597 Enable NUMA emulation. A flat machine will be split
1598 into virtual nodes when booted with "numa=fake=N", where N is the
1599 number of nodes. This is only useful for debugging.
1600
1601config NODES_SHIFT
d25e26b6 1602 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1603 range 1 10
1604 default "10" if MAXSMP
506f1d07 1605 default "6" if X86_64
506f1d07
SR
1606 default "3"
1607 depends on NEED_MULTIPLE_NODES
8f9ca475 1608 ---help---
1184dc2f 1609 Specify the maximum number of NUMA Nodes available on the target
692105b8 1610 system. Increases memory reserved to accommodate various tables.
506f1d07 1611
506f1d07 1612config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1613 def_bool y
506f1d07 1614 depends on X86_32 && DISCONTIGMEM
506f1d07 1615
506f1d07
SR
1616config ARCH_FLATMEM_ENABLE
1617 def_bool y
3b16651f 1618 depends on X86_32 && !NUMA
506f1d07
SR
1619
1620config ARCH_DISCONTIGMEM_ENABLE
2792107d 1621 def_bool n
b263295d 1622 depends on NUMA && X86_32
2792107d 1623 depends on BROKEN
b263295d 1624
506f1d07
SR
1625config ARCH_SPARSEMEM_ENABLE
1626 def_bool y
6ea30386 1627 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1628 select SPARSEMEM_STATIC if X86_32
1629 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1630
3b16651f 1631config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1632 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1633
506f1d07
SR
1634config ARCH_SELECT_MEMORY_MODEL
1635 def_bool y
b263295d 1636 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1637
1638config ARCH_MEMORY_PROBE
a0842b70 1639 bool "Enable sysfs memory/probe interface"
3120e25e 1640 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1641 help
1642 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1643 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1644 If you are unsure how to answer this question, answer N.
506f1d07 1645
3b16651f
TH
1646config ARCH_PROC_KCORE_TEXT
1647 def_bool y
1648 depends on X86_64 && PROC_KCORE
1649
a29815a3
AK
1650config ILLEGAL_POINTER_VALUE
1651 hex
1652 default 0 if X86_32
1653 default 0xdead000000000000 if X86_64
1654
7a67832c
DW
1655config X86_PMEM_LEGACY_DEVICE
1656 bool
1657
ec776ef6 1658config X86_PMEM_LEGACY
7a67832c 1659 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1660 depends on PHYS_ADDR_T_64BIT
1661 depends on BLK_DEV
7a67832c 1662 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1663 select LIBNVDIMM
ec776ef6
CH
1664 help
1665 Treat memory marked using the non-standard e820 type of 12 as used
1666 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1667 The kernel will offer these regions to the 'pmem' driver so
1668 they can be used for persistent storage.
1669
1670 Say Y if unsure.
1671
506f1d07
SR
1672config HIGHPTE
1673 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1674 depends on HIGHMEM
8f9ca475 1675 ---help---
506f1d07
SR
1676 The VM uses one page table entry for each page of physical memory.
1677 For systems with a lot of RAM, this can be wasteful of precious
1678 low memory. Setting this option will put user-space page table
1679 entries in high memory.
1680
9f077871 1681config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1682 bool "Check for low memory corruption"
1683 ---help---
1684 Periodically check for memory corruption in low memory, which
1685 is suspected to be caused by BIOS. Even when enabled in the
1686 configuration, it is disabled at runtime. Enable it by
1687 setting "memory_corruption_check=1" on the kernel command
1688 line. By default it scans the low 64k of memory every 60
1689 seconds; see the memory_corruption_check_size and
1690 memory_corruption_check_period parameters in
8c27ceff 1691 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1692
1693 When enabled with the default parameters, this option has
1694 almost no overhead, as it reserves a relatively small amount
1695 of memory and scans it infrequently. It both detects corruption
1696 and prevents it from affecting the running system.
1697
1698 It is, however, intended as a diagnostic tool; if repeatable
1699 BIOS-originated corruption always affects the same memory,
1700 you can use memmap= to prevent the kernel from using that
1701 memory.
9f077871 1702
c885df50 1703config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1704 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1705 depends on X86_CHECK_BIOS_CORRUPTION
1706 default y
8f9ca475
IM
1707 ---help---
1708 Set whether the default state of memory_corruption_check is
1709 on or off.
c885df50 1710
9ea77bdb 1711config X86_RESERVE_LOW
d0cd7425
PA
1712 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1713 default 64
1714 range 4 640
8f9ca475 1715 ---help---
d0cd7425
PA
1716 Specify the amount of low memory to reserve for the BIOS.
1717
1718 The first page contains BIOS data structures that the kernel
1719 must not use, so that page must always be reserved.
1720
1721 By default we reserve the first 64K of physical RAM, as a
1722 number of BIOSes are known to corrupt that memory range
1723 during events such as suspend/resume or monitor cable
1724 insertion, so it must not be used by the kernel.
fc381519 1725
d0cd7425
PA
1726 You can set this to 4 if you are absolutely sure that you
1727 trust the BIOS to get all its memory reservations and usages
1728 right. If you know your BIOS have problems beyond the
1729 default 64K area, you can set this to 640 to avoid using the
1730 entire low memory range.
fc381519 1731
d0cd7425
PA
1732 If you have doubts about the BIOS (e.g. suspend/resume does
1733 not work or there's kernel crashes after certain hardware
1734 hotplug events) then you might want to enable
1735 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1736 typical corruption patterns.
fc381519 1737
d0cd7425 1738 Leave this to the default value of 64 if you are unsure.
fc381519 1739
506f1d07
SR
1740config MATH_EMULATION
1741 bool
a5b9e5a2 1742 depends on MODIFY_LDT_SYSCALL
87d6021b 1743 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
506f1d07
SR
1744 ---help---
1745 Linux can emulate a math coprocessor (used for floating point
1746 operations) if you don't have one. 486DX and Pentium processors have
1747 a math coprocessor built in, 486SX and 386 do not, unless you added
1748 a 487DX or 387, respectively. (The messages during boot time can
1749 give you some hints here ["man dmesg"].) Everyone needs either a
1750 coprocessor or this emulation.
1751
1752 If you don't have a math coprocessor, you need to say Y here; if you
1753 say Y here even though you have a coprocessor, the coprocessor will
1754 be used nevertheless. (This behavior can be changed with the kernel
1755 command line option "no387", which comes handy if your coprocessor
1756 is broken. Try "man bootparam" or see the documentation of your boot
1757 loader (lilo or loadlin) about how to pass options to the kernel at
1758 boot time.) This means that it is a good idea to say Y here if you
1759 intend to use this kernel on different machines.
1760
1761 More information about the internals of the Linux math coprocessor
1762 emulation can be found in <file:arch/x86/math-emu/README>.
1763
1764 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1765 kernel, it won't hurt.
1766
1767config MTRR
6fc108a0 1768 def_bool y
6a108a14 1769 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1770 ---help---
1771 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1772 the Memory Type Range Registers (MTRRs) may be used to control
1773 processor access to memory ranges. This is most useful if you have
1774 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1775 allows bus write transfers to be combined into a larger transfer
1776 before bursting over the PCI/AGP bus. This can increase performance
1777 of image write operations 2.5 times or more. Saying Y here creates a
1778 /proc/mtrr file which may be used to manipulate your processor's
1779 MTRRs. Typically the X server should use this.
1780
1781 This code has a reasonably generic interface so that similar
1782 control registers on other processors can be easily supported
1783 as well:
1784
1785 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1786 Registers (ARRs) which provide a similar functionality to MTRRs. For
1787 these, the ARRs are used to emulate the MTRRs.
1788 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1789 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1790 write-combining. All of these processors are supported by this code
1791 and it makes sense to say Y here if you have one of them.
1792
1793 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1794 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1795 can lead to all sorts of problems, so it's good to say Y here.
1796
1797 You can safely say Y even if your machine doesn't have MTRRs, you'll
1798 just add about 9 KB to your kernel.
1799
cb1aaebe 1800 See <file:Documentation/x86/mtrr.rst> for more information.
506f1d07 1801
95ffa243 1802config MTRR_SANITIZER
2ffb3501 1803 def_bool y
95ffa243
YL
1804 prompt "MTRR cleanup support"
1805 depends on MTRR
8f9ca475 1806 ---help---
aba3728c
TG
1807 Convert MTRR layout from continuous to discrete, so X drivers can
1808 add writeback entries.
95ffa243 1809
aba3728c 1810 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1811 The largest mtrr entry size for a continuous block can be set with
aba3728c 1812 mtrr_chunk_size.
95ffa243 1813
2ffb3501 1814 If unsure, say Y.
95ffa243
YL
1815
1816config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1817 int "MTRR cleanup enable value (0-1)"
1818 range 0 1
1819 default "0"
95ffa243 1820 depends on MTRR_SANITIZER
8f9ca475 1821 ---help---
f5098d62 1822 Enable mtrr cleanup default value
95ffa243 1823
12031a62
YL
1824config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1825 int "MTRR cleanup spare reg num (0-7)"
1826 range 0 7
1827 default "1"
1828 depends on MTRR_SANITIZER
8f9ca475 1829 ---help---
12031a62 1830 mtrr cleanup spare entries default, it can be changed via
aba3728c 1831 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1832
2e5d9c85 1833config X86_PAT
6fc108a0 1834 def_bool y
6a108a14 1835 prompt "x86 PAT support" if EXPERT
2a8a2719 1836 depends on MTRR
8f9ca475 1837 ---help---
2e5d9c85 1838 Use PAT attributes to setup page level cache control.
042b78e4 1839
2e5d9c85 1840 PATs are the modern equivalents of MTRRs and are much more
1841 flexible than MTRRs.
1842
1843 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1844 spontaneous reboots) or a non-working video driver.
2e5d9c85 1845
1846 If unsure, say Y.
1847
46cf98cd
VP
1848config ARCH_USES_PG_UNCACHED
1849 def_bool y
1850 depends on X86_PAT
1851
628c6246
PA
1852config ARCH_RANDOM
1853 def_bool y
1854 prompt "x86 architectural random number generator" if EXPERT
1855 ---help---
1856 Enable the x86 architectural RDRAND instruction
1857 (Intel Bull Mountain technology) to generate random numbers.
1858 If supported, this is a high bandwidth, cryptographically
1859 secure hardware random number generator.
1860
51ae4a2d
PA
1861config X86_SMAP
1862 def_bool y
1863 prompt "Supervisor Mode Access Prevention" if EXPERT
1864 ---help---
1865 Supervisor Mode Access Prevention (SMAP) is a security
1866 feature in newer Intel processors. There is a small
1867 performance cost if this enabled and turned on; there is
1868 also a small increase in the kernel size if this is enabled.
1869
1870 If unsure, say Y.
1871
b971880f 1872config X86_UMIP
796ebc81 1873 def_bool y
b971880f
BM
1874 depends on CPU_SUP_INTEL || CPU_SUP_AMD
1875 prompt "User Mode Instruction Prevention" if EXPERT
1876 ---help---
1877 User Mode Instruction Prevention (UMIP) is a security feature in
1878 some x86 processors. If enabled, a general protection fault is
1879 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1880 executed in user mode. These instructions unnecessarily expose
1881 information about the hardware state.
796ebc81
RN
1882
1883 The vast majority of applications do not use these instructions.
1884 For the very few that do, software emulation is provided in
1885 specific cases in protected and virtual-8086 modes. Emulated
1886 results are dummy.
aa35f896 1887
72e9b5fe
DH
1888config X86_INTEL_MPX
1889 prompt "Intel MPX (Memory Protection Extensions)"
1890 def_bool n
df3735c5
RR
1891 # Note: only available in 64-bit mode due to VMA flags shortage
1892 depends on CPU_SUP_INTEL && X86_64
1893 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1894 ---help---
1895 MPX provides hardware features that can be used in
1896 conjunction with compiler-instrumented code to check
1897 memory references. It is designed to detect buffer
1898 overflow or underflow bugs.
1899
1900 This option enables running applications which are
1901 instrumented or otherwise use MPX. It does not use MPX
1902 itself inside the kernel or to protect the kernel
1903 against bad memory references.
1904
1905 Enabling this option will make the kernel larger:
1906 ~8k of kernel text and 36 bytes of data on a 64-bit
1907 defconfig. It adds a long to the 'mm_struct' which
1908 will increase the kernel memory overhead of each
1909 process and adds some branches to paths used during
1910 exec() and munmap().
1911
cb1aaebe 1912 For details, see Documentation/x86/intel_mpx.rst
72e9b5fe
DH
1913
1914 If unsure, say N.
1915
35e97790 1916config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1917 prompt "Intel Memory Protection Keys"
35e97790 1918 def_bool y
284244a9 1919 # Note: only available in 64-bit mode
35e97790 1920 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1921 select ARCH_USES_HIGH_VMA_FLAGS
1922 select ARCH_HAS_PKEYS
284244a9
DH
1923 ---help---
1924 Memory Protection Keys provides a mechanism for enforcing
1925 page-based protections, but without requiring modification of the
1926 page tables when an application changes protection domains.
1927
1eecbcdc 1928 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1929
1930 If unsure, say y.
35e97790 1931
db616173
MH
1932choice
1933 prompt "TSX enable mode"
1934 depends on CPU_SUP_INTEL
1935 default X86_INTEL_TSX_MODE_OFF
1936 help
1937 Intel's TSX (Transactional Synchronization Extensions) feature
1938 allows to optimize locking protocols through lock elision which
1939 can lead to a noticeable performance boost.
1940
1941 On the other hand it has been shown that TSX can be exploited
1942 to form side channel attacks (e.g. TAA) and chances are there
1943 will be more of those attacks discovered in the future.
1944
1945 Therefore TSX is not enabled by default (aka tsx=off). An admin
1946 might override this decision by tsx=on the command line parameter.
1947 Even with TSX enabled, the kernel will attempt to enable the best
1948 possible TAA mitigation setting depending on the microcode available
1949 for the particular machine.
1950
1951 This option allows to set the default tsx mode between tsx=on, =off
1952 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1953 details.
1954
1955 Say off if not sure, auto if TSX is in use but it should be used on safe
1956 platforms or on if TSX is in use and the security aspect of tsx is not
1957 relevant.
1958
1959config X86_INTEL_TSX_MODE_OFF
1960 bool "off"
1961 help
1962 TSX is disabled if possible - equals to tsx=off command line parameter.
1963
1964config X86_INTEL_TSX_MODE_ON
1965 bool "on"
1966 help
1967 TSX is always enabled on TSX capable HW - equals the tsx=on command
1968 line parameter.
1969
1970config X86_INTEL_TSX_MODE_AUTO
1971 bool "auto"
1972 help
1973 TSX is enabled on TSX capable HW that is believed to be safe against
1974 side channel attacks- equals the tsx=auto command line parameter.
1975endchoice
1976
506f1d07 1977config EFI
9ba16087 1978 bool "EFI runtime service support"
5b83683f 1979 depends on ACPI
f6ce5002 1980 select UCS2_STRING
022ee6c5 1981 select EFI_RUNTIME_WRAPPERS
506f1d07 1982 ---help---
8f9ca475
IM
1983 This enables the kernel to use EFI runtime services that are
1984 available (such as the EFI variable services).
506f1d07 1985
8f9ca475
IM
1986 This option is only useful on systems that have EFI firmware.
1987 In addition, you should use the latest ELILO loader available
1988 at <http://elilo.sourceforge.net> in order to take advantage
1989 of EFI runtime services. However, even with this option, the
1990 resultant kernel should continue to boot on existing non-EFI
1991 platforms.
506f1d07 1992
291f3632
MF
1993config EFI_STUB
1994 bool "EFI stub support"
b16d8c23 1995 depends on EFI && !X86_USE_3DNOW
7b2a583a 1996 select RELOCATABLE
291f3632
MF
1997 ---help---
1998 This kernel feature allows a bzImage to be loaded directly
1999 by EFI firmware without the use of a bootloader.
2000
4f4cfa6c 2001 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 2002
7d453eee
MF
2003config EFI_MIXED
2004 bool "EFI mixed-mode support"
2005 depends on EFI_STUB && X86_64
2006 ---help---
2007 Enabling this feature allows a 64-bit kernel to be booted
2008 on a 32-bit firmware, provided that your CPU supports 64-bit
2009 mode.
2010
2011 Note that it is not possible to boot a mixed-mode enabled
2012 kernel via the EFI boot stub - a bootloader that supports
2013 the EFI handover protocol must be used.
2014
2015 If unsure, say N.
2016
506f1d07 2017config SECCOMP
3c2362e6
HH
2018 def_bool y
2019 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 2020 ---help---
506f1d07
SR
2021 This kernel feature is useful for number crunching applications
2022 that may need to compute untrusted bytecode during their
2023 execution. By using pipes or other transports made available to
2024 the process as file descriptors supporting the read/write
2025 syscalls, it's possible to isolate those applications in
2026 their own address space using seccomp. Once seccomp is
9c0bbee8 2027 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
2028 and the task is only allowed to execute a few safe syscalls
2029 defined by each seccomp mode.
2030
2031 If unsure, say Y. Only embedded should say N here.
2032
8636a1f9 2033source "kernel/Kconfig.hz"
506f1d07
SR
2034
2035config KEXEC
2036 bool "kexec system call"
2965faa5 2037 select KEXEC_CORE
8f9ca475 2038 ---help---
506f1d07
SR
2039 kexec is a system call that implements the ability to shutdown your
2040 current kernel, and to start another kernel. It is like a reboot
2041 but it is independent of the system firmware. And like a reboot
2042 you can start any kernel with it, not just Linux.
2043
2044 The name comes from the similarity to the exec system call.
2045
2046 It is an ongoing process to be certain the hardware in a machine
2047 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
2048 initially work for you. As of this writing the exact hardware
2049 interface is strongly in flux, so no good recommendation can be
2050 made.
506f1d07 2051
74ca317c
VG
2052config KEXEC_FILE
2053 bool "kexec file based system call"
2965faa5 2054 select KEXEC_CORE
74ca317c 2055 select BUILD_BIN2C
74ca317c
VG
2056 depends on X86_64
2057 depends on CRYPTO=y
2058 depends on CRYPTO_SHA256=y
2059 ---help---
2060 This is new version of kexec system call. This system call is
2061 file based and takes file descriptors as system call argument
2062 for kernel and initramfs as opposed to list of segments as
2063 accepted by previous system call.
2064
b799a09f
AT
2065config ARCH_HAS_KEXEC_PURGATORY
2066 def_bool KEXEC_FILE
2067
99d5cadf 2068config KEXEC_SIG
8e7d8381 2069 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2070 depends on KEXEC_FILE
8e7d8381 2071 ---help---
d8eb8940 2072
99d5cadf
JB
2073 This option makes the kexec_file_load() syscall check for a valid
2074 signature of the kernel image. The image can still be loaded without
2075 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2076 there's a signature that we can check, then it must be valid.
2077
2078 In addition to this option, you need to enable signature
d8eb8940
BP
2079 verification for the corresponding kernel image type being
2080 loaded in order for this to work.
8e7d8381 2081
99d5cadf
JB
2082config KEXEC_SIG_FORCE
2083 bool "Require a valid signature in kexec_file_load() syscall"
2084 depends on KEXEC_SIG
2085 ---help---
2086 This option makes kernel signature verification mandatory for
2087 the kexec_file_load() syscall.
2088
8e7d8381
VG
2089config KEXEC_BZIMAGE_VERIFY_SIG
2090 bool "Enable bzImage signature verification support"
99d5cadf 2091 depends on KEXEC_SIG
8e7d8381
VG
2092 depends on SIGNED_PE_FILE_VERIFICATION
2093 select SYSTEM_TRUSTED_KEYRING
2094 ---help---
2095 Enable bzImage signature verification support.
2096
506f1d07 2097config CRASH_DUMP
04b69447 2098 bool "kernel crash dumps"
506f1d07 2099 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2100 ---help---
506f1d07
SR
2101 Generate crash dump after being started by kexec.
2102 This should be normally only set in special crash dump kernels
2103 which are loaded in the main kernel with kexec-tools into
2104 a specially reserved region and then later executed after
2105 a crash by kdump/kexec. The crash dump kernel must be compiled
2106 to a memory address not used by the main kernel or BIOS using
2107 PHYSICAL_START, or it must be built as a relocatable image
2108 (CONFIG_RELOCATABLE=y).
330d4810 2109 For more details see Documentation/admin-guide/kdump/kdump.rst
506f1d07 2110
3ab83521 2111config KEXEC_JUMP
6ea30386 2112 bool "kexec jump"
fee7b0d8 2113 depends on KEXEC && HIBERNATION
8f9ca475 2114 ---help---
89081d17
HY
2115 Jump between original kernel and kexeced kernel and invoke
2116 code in physical address mode via KEXEC
3ab83521 2117
506f1d07 2118config PHYSICAL_START
6a108a14 2119 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2120 default "0x1000000"
8f9ca475 2121 ---help---
506f1d07
SR
2122 This gives the physical address where the kernel is loaded.
2123
2124 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2125 bzImage will decompress itself to above physical address and
2126 run from there. Otherwise, bzImage will run from the address where
2127 it has been loaded by the boot loader and will ignore above physical
2128 address.
2129
2130 In normal kdump cases one does not have to set/change this option
2131 as now bzImage can be compiled as a completely relocatable image
2132 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2133 address. This option is mainly useful for the folks who don't want
2134 to use a bzImage for capturing the crash dump and want to use a
2135 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2136 to be specifically compiled to run from a specific memory area
2137 (normally a reserved region) and this option comes handy.
2138
ceefccc9
PA
2139 So if you are using bzImage for capturing the crash dump,
2140 leave the value here unchanged to 0x1000000 and set
2141 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2142 for capturing the crash dump change this value to start of
2143 the reserved region. In other words, it can be set based on
2144 the "X" value as specified in the "crashkernel=YM@XM"
2145 command line boot parameter passed to the panic-ed
330d4810 2146 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
ceefccc9 2147 for more details about crash dumps.
506f1d07
SR
2148
2149 Usage of bzImage for capturing the crash dump is recommended as
2150 one does not have to build two kernels. Same kernel can be used
2151 as production kernel and capture kernel. Above option should have
2152 gone away after relocatable bzImage support is introduced. But it
2153 is present because there are users out there who continue to use
2154 vmlinux for dump capture. This option should go away down the
2155 line.
2156
2157 Don't change this unless you know what you are doing.
2158
2159config RELOCATABLE
26717808
PA
2160 bool "Build a relocatable kernel"
2161 default y
8f9ca475 2162 ---help---
506f1d07
SR
2163 This builds a kernel image that retains relocation information
2164 so it can be loaded someplace besides the default 1MB.
2165 The relocations tend to make the kernel binary about 10% larger,
2166 but are discarded at runtime.
2167
2168 One use is for the kexec on panic case where the recovery kernel
2169 must live at a different physical address than the primary
2170 kernel.
2171
2172 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2173 it has been loaded at and the compile time physical address
8ab3820f 2174 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2175
8ab3820f 2176config RANDOMIZE_BASE
e8581e3d 2177 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2178 depends on RELOCATABLE
6807c846 2179 default y
8ab3820f 2180 ---help---
e8581e3d
BH
2181 In support of Kernel Address Space Layout Randomization (KASLR),
2182 this randomizes the physical address at which the kernel image
2183 is decompressed and the virtual address where the kernel
2184 image is mapped, as a security feature that deters exploit
2185 attempts relying on knowledge of the location of kernel
2186 code internals.
2187
ed9f007e
KC
2188 On 64-bit, the kernel physical and virtual addresses are
2189 randomized separately. The physical address will be anywhere
2190 between 16MB and the top of physical memory (up to 64TB). The
2191 virtual address will be randomized from 16MB up to 1GB (9 bits
2192 of entropy). Note that this also reduces the memory space
2193 available to kernel modules from 1.5GB to 1GB.
2194
2195 On 32-bit, the kernel physical and virtual addresses are
2196 randomized together. They will be randomized from 16MB up to
2197 512MB (8 bits of entropy).
e8581e3d
BH
2198
2199 Entropy is generated using the RDRAND instruction if it is
2200 supported. If RDTSC is supported, its value is mixed into
2201 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2202 supported, then entropy is read from the i8254 timer. The
2203 usable entropy is limited by the kernel being built using
2204 2GB addressing, and that PHYSICAL_ALIGN must be at a
2205 minimum of 2MB. As a result, only 10 bits of entropy are
2206 theoretically possible, but the implementations are further
2207 limited due to memory layouts.
e8581e3d 2208
6807c846 2209 If unsure, say Y.
8ab3820f
KC
2210
2211# Relocation on x86 needs some additional build support
845adf72
PA
2212config X86_NEED_RELOCS
2213 def_bool y
8ab3820f 2214 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2215
506f1d07 2216config PHYSICAL_ALIGN
a0215061 2217 hex "Alignment value to which kernel should be aligned"
8ab3820f 2218 default "0x200000"
a0215061
KC
2219 range 0x2000 0x1000000 if X86_32
2220 range 0x200000 0x1000000 if X86_64
8f9ca475 2221 ---help---
506f1d07
SR
2222 This value puts the alignment restrictions on physical address
2223 where kernel is loaded and run from. Kernel is compiled for an
2224 address which meets above alignment restriction.
2225
2226 If bootloader loads the kernel at a non-aligned address and
2227 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2228 address aligned to above value and run from there.
2229
2230 If bootloader loads the kernel at a non-aligned address and
2231 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2232 load address and decompress itself to the address it has been
2233 compiled for and run from there. The address for which kernel is
2234 compiled already meets above alignment restrictions. Hence the
2235 end result is that kernel runs from a physical address meeting
2236 above alignment restrictions.
2237
a0215061
KC
2238 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2239 this value must be a multiple of 0x200000.
2240
506f1d07
SR
2241 Don't change this unless you know what you are doing.
2242
eedb92ab
KS
2243config DYNAMIC_MEMORY_LAYOUT
2244 bool
2245 ---help---
2246 This option makes base addresses of vmalloc and vmemmap as well as
2247 __PAGE_OFFSET movable during boot.
2248
0483e1fa
TG
2249config RANDOMIZE_MEMORY
2250 bool "Randomize the kernel memory sections"
2251 depends on X86_64
2252 depends on RANDOMIZE_BASE
eedb92ab 2253 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2254 default RANDOMIZE_BASE
2255 ---help---
2256 Randomizes the base virtual address of kernel memory sections
2257 (physical memory mapping, vmalloc & vmemmap). This security feature
2258 makes exploits relying on predictable memory locations less reliable.
2259
2260 The order of allocations remains unchanged. Entropy is generated in
2261 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2262 configuration have in average 30,000 different possible virtual
2263 addresses for each memory section.
2264
6807c846 2265 If unsure, say Y.
0483e1fa 2266
90397a41
TG
2267config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2268 hex "Physical memory mapping padding" if EXPERT
2269 depends on RANDOMIZE_MEMORY
2270 default "0xa" if MEMORY_HOTPLUG
2271 default "0x0"
2272 range 0x1 0x40 if MEMORY_HOTPLUG
2273 range 0x0 0x40
2274 ---help---
2275 Define the padding in terabytes added to the existing physical
2276 memory size during kernel memory randomization. It is useful
2277 for memory hotplug support but reduces the entropy available for
2278 address randomization.
2279
2280 If unsure, leave at the default value.
2281
506f1d07 2282config HOTPLUG_CPU
bebd024e 2283 def_bool y
40b31360 2284 depends on SMP
506f1d07 2285
80aa1dff
FY
2286config BOOTPARAM_HOTPLUG_CPU0
2287 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2288 depends on HOTPLUG_CPU
80aa1dff
FY
2289 ---help---
2290 Set whether default state of cpu0_hotpluggable is on or off.
2291
2292 Say Y here to enable CPU0 hotplug by default. If this switch
2293 is turned on, there is no need to give cpu0_hotplug kernel
2294 parameter and the CPU0 hotplug feature is enabled by default.
2295
2296 Please note: there are two known CPU0 dependencies if you want
2297 to enable the CPU0 hotplug feature either by this switch or by
2298 cpu0_hotplug kernel parameter.
2299
2300 First, resume from hibernate or suspend always starts from CPU0.
2301 So hibernate and suspend are prevented if CPU0 is offline.
2302
2303 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2304 offline if any interrupt can not migrate out of CPU0. There may
2305 be other CPU0 dependencies.
2306
2307 Please make sure the dependencies are under your control before
2308 you enable this feature.
2309
2310 Say N if you don't want to enable CPU0 hotplug feature by default.
2311 You still can enable the CPU0 hotplug feature at boot by kernel
2312 parameter cpu0_hotplug.
2313
a71c8bc5
FY
2314config DEBUG_HOTPLUG_CPU0
2315 def_bool n
2316 prompt "Debug CPU0 hotplug"
2c922cd0 2317 depends on HOTPLUG_CPU
a71c8bc5
FY
2318 ---help---
2319 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2320 soon as possible and boots up userspace with CPU0 offlined. User
2321 can online CPU0 back after boot time.
2322
2323 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2324 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2325 compilation or giving cpu0_hotplug kernel parameter at boot.
2326
2327 If unsure, say N.
2328
506f1d07 2329config COMPAT_VDSO
b0b49f26
AL
2330 def_bool n
2331 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2332 depends on COMPAT_32
8f9ca475 2333 ---help---
b0b49f26
AL
2334 Certain buggy versions of glibc will crash if they are
2335 presented with a 32-bit vDSO that is not mapped at the address
2336 indicated in its segment table.
e84446de 2337
b0b49f26
AL
2338 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2339 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2340 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2341 the only released version with the bug, but OpenSUSE 9
2342 contains a buggy "glibc 2.3.2".
506f1d07 2343
b0b49f26
AL
2344 The symptom of the bug is that everything crashes on startup, saying:
2345 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2346
2347 Saying Y here changes the default value of the vdso32 boot
2348 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2349 This works around the glibc bug but hurts performance.
2350
2351 If unsure, say N: if you are compiling your own kernel, you
2352 are unlikely to be using a buggy version of glibc.
506f1d07 2353
3dc33bd3
KC
2354choice
2355 prompt "vsyscall table for legacy applications"
2356 depends on X86_64
625b7b7f 2357 default LEGACY_VSYSCALL_XONLY
3dc33bd3
KC
2358 help
2359 Legacy user code that does not know how to find the vDSO expects
2360 to be able to issue three syscalls by calling fixed addresses in
2361 kernel space. Since this location is not randomized with ASLR,
2362 it can be used to assist security vulnerability exploitation.
2363
2364 This setting can be changed at boot time via the kernel command
bd49e16e 2365 line parameter vsyscall=[emulate|xonly|none].
3dc33bd3
KC
2366
2367 On a system with recent enough glibc (2.14 or newer) and no
2368 static binaries, you can say None without a performance penalty
2369 to improve security.
2370
bd49e16e 2371 If unsure, select "Emulate execution only".
3dc33bd3 2372
3dc33bd3 2373 config LEGACY_VSYSCALL_EMULATE
bd49e16e 2374 bool "Full emulation"
3dc33bd3 2375 help
bd49e16e
AL
2376 The kernel traps and emulates calls into the fixed vsyscall
2377 address mapping. This makes the mapping non-executable, but
2378 it still contains readable known contents, which could be
2379 used in certain rare security vulnerability exploits. This
2380 configuration is recommended when using legacy userspace
2381 that still uses vsyscalls along with legacy binary
2382 instrumentation tools that require code to be readable.
2383
2384 An example of this type of legacy userspace is running
2385 Pin on an old binary that still uses vsyscalls.
2386
2387 config LEGACY_VSYSCALL_XONLY
2388 bool "Emulate execution only"
2389 help
2390 The kernel traps and emulates calls into the fixed vsyscall
2391 address mapping and does not allow reads. This
2392 configuration is recommended when userspace might use the
2393 legacy vsyscall area but support for legacy binary
2394 instrumentation of legacy code is not needed. It mitigates
2395 certain uses of the vsyscall area as an ASLR-bypassing
2396 buffer.
3dc33bd3
KC
2397
2398 config LEGACY_VSYSCALL_NONE
2399 bool "None"
2400 help
2401 There will be no vsyscall mapping at all. This will
2402 eliminate any risk of ASLR bypass due to the vsyscall
2403 fixed address mapping. Attempts to use the vsyscalls
2404 will be reported to dmesg, so that either old or
2405 malicious userspace programs can be identified.
2406
2407endchoice
2408
516cbf37
TB
2409config CMDLINE_BOOL
2410 bool "Built-in kernel command line"
8f9ca475 2411 ---help---
516cbf37
TB
2412 Allow for specifying boot arguments to the kernel at
2413 build time. On some systems (e.g. embedded ones), it is
2414 necessary or convenient to provide some or all of the
2415 kernel boot arguments with the kernel itself (that is,
2416 to not rely on the boot loader to provide them.)
2417
2418 To compile command line arguments into the kernel,
2419 set this option to 'Y', then fill in the
69711ca1 2420 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2421
2422 Systems with fully functional boot loaders (i.e. non-embedded)
2423 should leave this option set to 'N'.
2424
2425config CMDLINE
2426 string "Built-in kernel command string"
2427 depends on CMDLINE_BOOL
2428 default ""
8f9ca475 2429 ---help---
516cbf37
TB
2430 Enter arguments here that should be compiled into the kernel
2431 image and used at boot time. If the boot loader provides a
2432 command line at boot time, it is appended to this string to
2433 form the full kernel command line, when the system boots.
2434
2435 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2436 change this behavior.
2437
2438 In most cases, the command line (whether built-in or provided
2439 by the boot loader) should specify the device for the root
2440 file system.
2441
2442config CMDLINE_OVERRIDE
2443 bool "Built-in command line overrides boot loader arguments"
516cbf37 2444 depends on CMDLINE_BOOL
8f9ca475 2445 ---help---
516cbf37
TB
2446 Set this option to 'Y' to have the kernel ignore the boot loader
2447 command line, and use ONLY the built-in command line.
2448
2449 This is used to work around broken boot loaders. This should
2450 be set to 'N' under normal conditions.
2451
a5b9e5a2
AL
2452config MODIFY_LDT_SYSCALL
2453 bool "Enable the LDT (local descriptor table)" if EXPERT
2454 default y
2455 ---help---
2456 Linux can allow user programs to install a per-process x86
2457 Local Descriptor Table (LDT) using the modify_ldt(2) system
2458 call. This is required to run 16-bit or segmented code such as
2459 DOSEMU or some Wine programs. It is also used by some very old
2460 threading libraries.
2461
2462 Enabling this feature adds a small amount of overhead to
2463 context switches and increases the low-level kernel attack
2464 surface. Disabling it removes the modify_ldt(2) system call.
2465
2466 Saying 'N' here may make sense for embedded or server kernels.
2467
b700e7f0
SJ
2468source "kernel/livepatch/Kconfig"
2469
506f1d07
SR
2470endmenu
2471
3072e413
MH
2472config ARCH_HAS_ADD_PAGES
2473 def_bool y
2474 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2475
506f1d07
SR
2476config ARCH_ENABLE_MEMORY_HOTPLUG
2477 def_bool y
2478 depends on X86_64 || (X86_32 && HIGHMEM)
2479
35551053
GH
2480config ARCH_ENABLE_MEMORY_HOTREMOVE
2481 def_bool y
2482 depends on MEMORY_HOTPLUG
2483
e534c7c5 2484config USE_PERCPU_NUMA_NODE_ID
645a7919 2485 def_bool y
e534c7c5
LS
2486 depends on NUMA
2487
9491846f
KS
2488config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2489 def_bool y
2490 depends on X86_64 || X86_PAE
2491
c177c81e
NH
2492config ARCH_ENABLE_HUGEPAGE_MIGRATION
2493 def_bool y
2494 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2495
9c670ea3
NH
2496config ARCH_ENABLE_THP_MIGRATION
2497 def_bool y
2498 depends on X86_64 && TRANSPARENT_HUGEPAGE
2499
da85f865 2500menu "Power management and ACPI options"
e279b6c1
SR
2501
2502config ARCH_HIBERNATION_HEADER
3c2362e6 2503 def_bool y
44556530 2504 depends on HIBERNATION
e279b6c1
SR
2505
2506source "kernel/power/Kconfig"
2507
2508source "drivers/acpi/Kconfig"
2509
efafc8b2
FT
2510source "drivers/sfi/Kconfig"
2511
a6b68076 2512config X86_APM_BOOT
6fc108a0 2513 def_bool y
282e5aab 2514 depends on APM
a6b68076 2515
e279b6c1
SR
2516menuconfig APM
2517 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2518 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2519 ---help---
2520 APM is a BIOS specification for saving power using several different
2521 techniques. This is mostly useful for battery powered laptops with
2522 APM compliant BIOSes. If you say Y here, the system time will be
2523 reset after a RESUME operation, the /proc/apm device will provide
2524 battery status information, and user-space programs will receive
2525 notification of APM "events" (e.g. battery status change).
2526
2527 If you select "Y" here, you can disable actual use of the APM
2528 BIOS by passing the "apm=off" option to the kernel at boot time.
2529
2530 Note that the APM support is almost completely disabled for
2531 machines with more than one CPU.
2532
2533 In order to use APM, you will need supporting software. For location
151f4e2b 2534 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2535 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2536 <http://www.tldp.org/docs.html#howto>.
2537
2538 This driver does not spin down disk drives (see the hdparm(8)
2539 manpage ("man 8 hdparm") for that), and it doesn't turn off
2540 VESA-compliant "green" monitors.
2541
2542 This driver does not support the TI 4000M TravelMate and the ACER
2543 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2544 desktop machines also don't have compliant BIOSes, and this driver
2545 may cause those machines to panic during the boot phase.
2546
2547 Generally, if you don't have a battery in your machine, there isn't
2548 much point in using this driver and you should say N. If you get
2549 random kernel OOPSes or reboots that don't seem to be related to
2550 anything, try disabling/enabling this option (or disabling/enabling
2551 APM in your BIOS).
2552
2553 Some other things you should try when experiencing seemingly random,
2554 "weird" problems:
2555
2556 1) make sure that you have enough swap space and that it is
2557 enabled.
2558 2) pass the "no-hlt" option to the kernel
2559 3) switch on floating point emulation in the kernel and pass
2560 the "no387" option to the kernel
2561 4) pass the "floppy=nodma" option to the kernel
2562 5) pass the "mem=4M" option to the kernel (thereby disabling
2563 all but the first 4 MB of RAM)
2564 6) make sure that the CPU is not over clocked.
2565 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2566 8) disable the cache from your BIOS settings
2567 9) install a fan for the video card or exchange video RAM
2568 10) install a better fan for the CPU
2569 11) exchange RAM chips
2570 12) exchange the motherboard.
2571
2572 To compile this driver as a module, choose M here: the
2573 module will be called apm.
2574
2575if APM
2576
2577config APM_IGNORE_USER_SUSPEND
2578 bool "Ignore USER SUSPEND"
8f9ca475 2579 ---help---
e279b6c1
SR
2580 This option will ignore USER SUSPEND requests. On machines with a
2581 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2582 series notebooks, it is necessary to say Y because of a BIOS bug.
2583
2584config APM_DO_ENABLE
2585 bool "Enable PM at boot time"
2586 ---help---
2587 Enable APM features at boot time. From page 36 of the APM BIOS
2588 specification: "When disabled, the APM BIOS does not automatically
2589 power manage devices, enter the Standby State, enter the Suspend
2590 State, or take power saving steps in response to CPU Idle calls."
2591 This driver will make CPU Idle calls when Linux is idle (unless this
2592 feature is turned off -- see "Do CPU IDLE calls", below). This
2593 should always save battery power, but more complicated APM features
2594 will be dependent on your BIOS implementation. You may need to turn
2595 this option off if your computer hangs at boot time when using APM
2596 support, or if it beeps continuously instead of suspending. Turn
2597 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2598 T400CDT. This is off by default since most machines do fine without
2599 this feature.
2600
2601config APM_CPU_IDLE
dd8af076 2602 depends on CPU_IDLE
e279b6c1 2603 bool "Make CPU Idle calls when idle"
8f9ca475 2604 ---help---
e279b6c1
SR
2605 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2606 On some machines, this can activate improved power savings, such as
2607 a slowed CPU clock rate, when the machine is idle. These idle calls
2608 are made after the idle loop has run for some length of time (e.g.,
2609 333 mS). On some machines, this will cause a hang at boot time or
2610 whenever the CPU becomes idle. (On machines with more than one CPU,
2611 this option does nothing.)
2612
2613config APM_DISPLAY_BLANK
2614 bool "Enable console blanking using APM"
8f9ca475 2615 ---help---
e279b6c1
SR
2616 Enable console blanking using the APM. Some laptops can use this to
2617 turn off the LCD backlight when the screen blanker of the Linux
2618 virtual console blanks the screen. Note that this is only used by
2619 the virtual console screen blanker, and won't turn off the backlight
2620 when using the X Window system. This also doesn't have anything to
2621 do with your VESA-compliant power-saving monitor. Further, this
2622 option doesn't work for all laptops -- it might not turn off your
2623 backlight at all, or it might print a lot of errors to the console,
2624 especially if you are using gpm.
2625
2626config APM_ALLOW_INTS
2627 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2628 ---help---
e279b6c1
SR
2629 Normally we disable external interrupts while we are making calls to
2630 the APM BIOS as a measure to lessen the effects of a badly behaving
2631 BIOS implementation. The BIOS should reenable interrupts if it
2632 needs to. Unfortunately, some BIOSes do not -- especially those in
2633 many of the newer IBM Thinkpads. If you experience hangs when you
2634 suspend, try setting this to Y. Otherwise, say N.
2635
e279b6c1
SR
2636endif # APM
2637
bb0a56ec 2638source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2639
2640source "drivers/cpuidle/Kconfig"
2641
27471fdb
AH
2642source "drivers/idle/Kconfig"
2643
e279b6c1
SR
2644endmenu
2645
2646
2647menu "Bus options (PCI etc.)"
2648
e279b6c1
SR
2649choice
2650 prompt "PCI access mode"
efefa6f6 2651 depends on X86_32 && PCI
e279b6c1
SR
2652 default PCI_GOANY
2653 ---help---
2654 On PCI systems, the BIOS can be used to detect the PCI devices and
2655 determine their configuration. However, some old PCI motherboards
2656 have BIOS bugs and may crash if this is done. Also, some embedded
2657 PCI-based systems don't have any BIOS at all. Linux can also try to
2658 detect the PCI hardware directly without using the BIOS.
2659
2660 With this option, you can specify how Linux should detect the
2661 PCI devices. If you choose "BIOS", the BIOS will be used,
2662 if you choose "Direct", the BIOS won't be used, and if you
2663 choose "MMConfig", then PCI Express MMCONFIG will be used.
2664 If you choose "Any", the kernel will try MMCONFIG, then the
2665 direct access method and falls back to the BIOS if that doesn't
2666 work. If unsure, go with the default, which is "Any".
2667
2668config PCI_GOBIOS
2669 bool "BIOS"
2670
2671config PCI_GOMMCONFIG
2672 bool "MMConfig"
2673
2674config PCI_GODIRECT
2675 bool "Direct"
2676
3ef0e1f8 2677config PCI_GOOLPC
76fb6570 2678 bool "OLPC XO-1"
3ef0e1f8
AS
2679 depends on OLPC
2680
2bdd1b03
AS
2681config PCI_GOANY
2682 bool "Any"
2683
e279b6c1
SR
2684endchoice
2685
2686config PCI_BIOS
3c2362e6 2687 def_bool y
efefa6f6 2688 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2689
2690# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2691config PCI_DIRECT
3c2362e6 2692 def_bool y
0aba496f 2693 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2694
2695config PCI_MMCONFIG
b45c9f36
JK
2696 bool "Support mmconfig PCI config space access" if X86_64
2697 default y
8364e1f8 2698 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2699 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2700
3ef0e1f8 2701config PCI_OLPC
2bdd1b03
AS
2702 def_bool y
2703 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2704
b5401a96
AN
2705config PCI_XEN
2706 def_bool y
2707 depends on PCI && XEN
2708 select SWIOTLB_XEN
2709
8364e1f8
JK
2710config MMCONF_FAM10H
2711 def_bool y
2712 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2713
3f6ea84a 2714config PCI_CNB20LE_QUIRK
6a108a14 2715 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2716 depends on PCI
3f6ea84a
IS
2717 help
2718 Read the PCI windows out of the CNB20LE host bridge. This allows
2719 PCI hotplug to work on systems with the CNB20LE chipset which do
2720 not have ACPI.
2721
64a5fed6
BH
2722 There's no public spec for this chipset, and this functionality
2723 is known to be incomplete.
2724
2725 You should say N unless you know you need this.
2726
3a495511 2727config ISA_BUS
17a2a129 2728 bool "ISA bus support on modern systems" if EXPERT
3a495511 2729 help
17a2a129
WBG
2730 Expose ISA bus device drivers and options available for selection and
2731 configuration. Enable this option if your target machine has an ISA
2732 bus. ISA is an older system, displaced by PCI and newer bus
2733 architectures -- if your target machine is modern, it probably does
2734 not have an ISA bus.
3a495511
WBG
2735
2736 If unsure, say N.
2737
1c00f016 2738# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2739config ISA_DMA_API
1c00f016
DR
2740 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2741 default y
2742 help
2743 Enables ISA-style DMA support for devices requiring such controllers.
2744 If unsure, say Y.
e279b6c1 2745
51e68d05
LT
2746if X86_32
2747
e279b6c1
SR
2748config ISA
2749 bool "ISA support"
8f9ca475 2750 ---help---
e279b6c1
SR
2751 Find out whether you have ISA slots on your motherboard. ISA is the
2752 name of a bus system, i.e. the way the CPU talks to the other stuff
2753 inside your box. Other bus systems are PCI, EISA, MicroChannel
2754 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2755 newer boards don't support it. If you have ISA, say Y, otherwise N.
2756
e279b6c1
SR
2757config SCx200
2758 tristate "NatSemi SCx200 support"
8f9ca475 2759 ---help---
e279b6c1
SR
2760 This provides basic support for National Semiconductor's
2761 (now AMD's) Geode processors. The driver probes for the
2762 PCI-IDs of several on-chip devices, so its a good dependency
2763 for other scx200_* drivers.
2764
2765 If compiled as a module, the driver is named scx200.
2766
2767config SCx200HR_TIMER
2768 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2769 depends on SCx200
e279b6c1 2770 default y
8f9ca475 2771 ---help---
e279b6c1
SR
2772 This driver provides a clocksource built upon the on-chip
2773 27MHz high-resolution timer. Its also a workaround for
2774 NSC Geode SC-1100's buggy TSC, which loses time when the
2775 processor goes idle (as is done by the scheduler). The
2776 other workaround is idle=poll boot option.
2777
3ef0e1f8
AS
2778config OLPC
2779 bool "One Laptop Per Child support"
54008979 2780 depends on !X86_PAE
3c554946 2781 select GPIOLIB
dc3119e7 2782 select OF
45bb1674 2783 select OF_PROMTREE
b4e51854 2784 select IRQ_DOMAIN
0c3d931b 2785 select OLPC_EC
8f9ca475 2786 ---help---
3ef0e1f8
AS
2787 Add support for detecting the unique features of the OLPC
2788 XO hardware.
2789
a3128588
DD
2790config OLPC_XO1_PM
2791 bool "OLPC XO-1 Power Management"
fa112cf1 2792 depends on OLPC && MFD_CS5535=y && PM_SLEEP
bf1ebf00 2793 ---help---
97c4cb71 2794 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2795
cfee9597
DD
2796config OLPC_XO1_RTC
2797 bool "OLPC XO-1 Real Time Clock"
2798 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2799 ---help---
2800 Add support for the XO-1 real time clock, which can be used as a
2801 programmable wakeup source.
2802
7feda8e9
DD
2803config OLPC_XO1_SCI
2804 bool "OLPC XO-1 SCI extras"
92e830f2 2805 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2806 depends on INPUT=y
d8d01a63 2807 select POWER_SUPPLY
7feda8e9
DD
2808 ---help---
2809 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2810 - EC-driven system wakeups
7feda8e9 2811 - Power button
7bc74b3d 2812 - Ebook switch
2cf2baea 2813 - Lid switch
e1040ac6
DD
2814 - AC adapter status updates
2815 - Battery status updates
7feda8e9 2816
a0f30f59
DD
2817config OLPC_XO15_SCI
2818 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2819 depends on OLPC && ACPI
2820 select POWER_SUPPLY
a0f30f59
DD
2821 ---help---
2822 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2823 - EC-driven system wakeups
2824 - AC adapter status updates
2825 - Battery status updates
bf1ebf00 2826
d4f3e350
EW
2827config ALIX
2828 bool "PCEngines ALIX System Support (LED setup)"
2829 select GPIOLIB
2830 ---help---
2831 This option enables system support for the PCEngines ALIX.
2832 At present this just sets up LEDs for GPIO control on
2833 ALIX2/3/6 boards. However, other system specific setup should
2834 get added here.
2835
2836 Note: You must still enable the drivers for GPIO and LED support
2837 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2838
2839 Note: You have to set alix.force=1 for boards with Award BIOS.
2840
da4e3302
PP
2841config NET5501
2842 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2843 select GPIOLIB
2844 ---help---
2845 This option enables system support for the Soekris Engineering net5501.
2846
3197059a
PP
2847config GEOS
2848 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2849 select GPIOLIB
2850 depends on DMI
2851 ---help---
2852 This option enables system support for the Traverse Technologies GEOS.
2853
7d029125
VD
2854config TS5500
2855 bool "Technologic Systems TS-5500 platform support"
2856 depends on MELAN
2857 select CHECK_SIGNATURE
2858 select NEW_LEDS
2859 select LEDS_CLASS
2860 ---help---
2861 This option enables system support for the Technologic Systems TS-5500.
2862
bc0120fd
SR
2863endif # X86_32
2864
23ac4ae8 2865config AMD_NB
e279b6c1 2866 def_bool y
0e152cd7 2867 depends on CPU_SUP_AMD && PCI
e279b6c1 2868
e3263ab3
DH
2869config X86_SYSFB
2870 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2871 help
2872 Firmwares often provide initial graphics framebuffers so the BIOS,
2873 bootloader or kernel can show basic video-output during boot for
2874 user-guidance and debugging. Historically, x86 used the VESA BIOS
2875 Extensions and EFI-framebuffers for this, which are mostly limited
2876 to x86.
2877 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2878 framebuffers so the new generic system-framebuffer drivers can be
2879 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2880 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DH
2881 drivers like efifb, vesafb and uvesafb can pick it up.
2882 If this option is not selected, all system framebuffers are always
2883 marked as fallback platform framebuffers as usual.
2884
2885 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2886 not be able to pick up generic system framebuffers if this option
2887 is selected. You are highly encouraged to enable simplefb as
2888 replacement if you select this option. simplefb can correctly deal
2889 with generic system framebuffers. But you should still keep vesafb
2890 and others enabled as fallback if a system framebuffer is
2891 incompatible with simplefb.
2892
2893 If unsure, say Y.
2894
e279b6c1
SR
2895endmenu
2896
2897
1572497c 2898menu "Binary Emulations"
e279b6c1
SR
2899
2900config IA32_EMULATION
2901 bool "IA32 Emulation"
2902 depends on X86_64
39f88911 2903 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2904 select BINFMT_ELF
a97f52e6 2905 select COMPAT_BINFMT_ELF
39f88911 2906 select COMPAT_OLD_SIGACTION
8f9ca475 2907 ---help---
5fd92e65
L
2908 Include code to run legacy 32-bit programs under a
2909 64-bit kernel. You should likely turn this on, unless you're
2910 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2911
2912config IA32_AOUT
8f9ca475
IM
2913 tristate "IA32 a.out support"
2914 depends on IA32_EMULATION
eac61655 2915 depends on BROKEN
8f9ca475
IM
2916 ---help---
2917 Support old a.out binaries in the 32bit emulation.
e279b6c1 2918
0bf62763 2919config X86_X32
6ea30386 2920 bool "x32 ABI for 64-bit mode"
9b54050b 2921 depends on X86_64
5fd92e65
L
2922 ---help---
2923 Include code to run binaries for the x32 native 32-bit ABI
2924 for 64-bit processors. An x32 process gets access to the
2925 full 64-bit register file and wide data path while leaving
2926 pointers at 32 bits for smaller memory footprint.
2927
2928 You will need a recent binutils (2.22 or later) with
2929 elf32_x86_64 support enabled to compile a kernel with this
2930 option set.
2931
953fee1d
IM
2932config COMPAT_32
2933 def_bool y
2934 depends on IA32_EMULATION || X86_32
2935 select HAVE_UID16
2936 select OLD_SIGSUSPEND3
2937
e279b6c1 2938config COMPAT
3c2362e6 2939 def_bool y
0bf62763 2940 depends on IA32_EMULATION || X86_X32
e279b6c1 2941
3120e25e 2942if COMPAT
e279b6c1 2943config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2944 def_bool y
e279b6c1
SR
2945
2946config SYSVIPC_COMPAT
3c2362e6 2947 def_bool y
3120e25e 2948 depends on SYSVIPC
3120e25e 2949endif
ee009e4a 2950
e279b6c1
SR
2951endmenu
2952
2953
e5beae16
KP
2954config HAVE_ATOMIC_IOMAP
2955 def_bool y
2956 depends on X86_32
2957
4692d77f
AR
2958config X86_DEV_DMA_OPS
2959 bool
f7219a53 2960
e279b6c1
SR
2961source "drivers/firmware/Kconfig"
2962
edf88417 2963source "arch/x86/kvm/Kconfig"