x86/mce: Drop AMD-specific "DEFERRED" case from Intel severity rule list
[linux-block.git] / arch / x86 / Kconfig
CommitLineData
b2441318 1# SPDX-License-Identifier: GPL-2.0
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SR
2# Select 32 or 64 bit
3config 64BIT
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MY
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
a7f7f624 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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JB
11 def_bool y
12 depends on !64BIT
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IM
13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
117ed454 17 select HAVE_DEBUG_STACKOVERFLOW
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IM
18 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
7ac87074 20 select GENERIC_VDSO_32
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SR
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
1032c0ba 33
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SRV
34config FORCE_DYNAMIC_FTRACE
35 def_bool y
36 depends on X86_32
37 depends on FUNCTION_TRACER
38 select DYNAMIC_FTRACE
39 help
40 We keep the static function tracing (!DYNAMIC_FTRACE) around
41 in order to test the non static function tracing in the
42 generic code, as other architectures still use it. But we
43 only need to keep it around for x86_64. No need to keep it
44 for x86_32. For x86_32, force DYNAMIC_FTRACE.
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IM
45#
46# Arch settings
47#
48# ( Note that options that are marked 'if X86_64' could in principle be
49# ported to 32-bit as well. )
50#
8d5fffb9 51config X86
3c2362e6 52 def_bool y
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53 #
54 # Note: keep this list sorted alphabetically
55 #
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56 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
57 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 58 select ARCH_32BIT_OFF_T if X86_32
2a21ad57 59 select ARCH_CLOCKSOURCE_INIT
c763ea26 60 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 61 select ARCH_HAS_DEBUG_VIRTUAL
399145f9 62 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
21266be9 63 select ARCH_HAS_DEVMEM_IS_ALLOWED
b1a57bbf 64 select ARCH_HAS_EARLY_DEBUG if KGDB
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
0f1441b4 70 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
0c9c1d56 71 select ARCH_HAS_MEM_ENCRYPT
10bcc80e 72 select ARCH_HAS_MEMBARRIER_SYNC_CORE
0ebeea8c 73 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
c763ea26 74 select ARCH_HAS_PMEM_API if X86_64
17596731 75 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 76 select ARCH_HAS_PTE_SPECIAL
0aed55af 77 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
092b31aa 78 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
d2852a22 79 select ARCH_HAS_SET_MEMORY
d253ca0c 80 select ARCH_HAS_SET_DIRECT_MAP
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LA
81 select ARCH_HAS_STRICT_KERNEL_RWX
82 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 83 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
25c619e5 84 select ARCH_HAS_SYSCALL_WRAPPER
c6d30853 85 select ARCH_HAS_UBSAN_SANITIZE_ALL
7e01ccb4 86 select ARCH_HAS_DEBUG_WX
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IM
87 select ARCH_HAVE_NMI_SAFE_CMPXCHG
88 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 89 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 90 select ARCH_MIGHT_HAVE_PC_SERIO
3599fe12 91 select ARCH_STACKWALK
2c870e61 92 select ARCH_SUPPORTS_ACPI
6471b825 93 select ARCH_SUPPORTS_ATOMIC_RMW
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IM
94 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
95 select ARCH_USE_BUILTIN_BSWAP
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IM
96 select ARCH_USE_QUEUED_RWLOCKS
97 select ARCH_USE_QUEUED_SPINLOCKS
2ce0d7f9 98 select ARCH_USE_SYM_ANNOTATIONS
ce4a4e56 99 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
81c22041 100 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
c763ea26 101 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
3876d4a3 102 select ARCH_WANT_HUGE_PMD_SHARE
38d8b4e6 103 select ARCH_WANTS_THP_SWAP if X86_64
10916706 104 select BUILDTIME_TABLE_SORT
6471b825 105 select CLKEVT_I8253
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IM
106 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107 select CLOCKSOURCE_WATCHDOG
6471b825 108 select DCACHE_WORD_ACCESS
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LT
109 select EDAC_ATOMIC_SCRUB
110 select EDAC_SUPPORT
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111 select GENERIC_CLOCKEVENTS
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_CLOCKEVENTS_MIN_ADJUST
114 select GENERIC_CMOS_UPDATE
115 select GENERIC_CPU_AUTOPROBE
61dc0f55 116 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 117 select GENERIC_EARLY_IOREMAP
27d6b4d1 118 select GENERIC_ENTRY
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IM
119 select GENERIC_FIND_FIRST_BIT
120 select GENERIC_IOMAP
c7d6c9dd 121 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 122 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 123 select GENERIC_IRQ_MIGRATION if SMP
6471b825 124 select GENERIC_IRQ_PROBE
c201c917 125 select GENERIC_IRQ_RESERVATION_MODE
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126 select GENERIC_IRQ_SHOW
127 select GENERIC_PENDING_IRQ if SMP
2ae27137 128 select GENERIC_PTDUMP
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129 select GENERIC_SMP_IDLE_THREAD
130 select GENERIC_STRNCPY_FROM_USER
131 select GENERIC_STRNLEN_USER
132 select GENERIC_TIME_VSYSCALL
7ac87074 133 select GENERIC_GETTIMEOFDAY
550a77a7 134 select GENERIC_VDSO_TIME_NS
39656e83 135 select GUP_GET_PTE_LOW_HIGH if X86_PAE
17e5888e 136 select HARDIRQS_SW_RESEND
7edaeb68 137 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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138 select HAVE_ACPI_APEI if ACPI
139 select HAVE_ACPI_APEI_NMI if ACPI
140 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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141 select HAVE_ARCH_AUDITSYSCALL
142 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
143 select HAVE_ARCH_JUMP_LABEL
b34006c4 144 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 145 select HAVE_ARCH_KASAN if X86_64
0609ae01 146 select HAVE_ARCH_KASAN_VMALLOC if X86_64
6471b825 147 select HAVE_ARCH_KGDB
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DC
148 select HAVE_ARCH_MMAP_RND_BITS if MMU
149 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 150 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 151 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 152 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 153 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 154 select HAVE_ARCH_STACKLEAK
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155 select HAVE_ARCH_TRACEHOOK
156 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 157 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
b64d8d1e 158 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
e37e43a4 159 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 160 select HAVE_ARCH_WITHIN_STACK_FRAMES
2ff2b7ec 161 select HAVE_ASM_MODVERSIONS
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162 select HAVE_CMPXCHG_DOUBLE
163 select HAVE_CMPXCHG_LOCAL
164 select HAVE_CONTEXT_TRACKING if X86_64
cf4db259 165 select HAVE_C_RECORDMCOUNT
6471b825 166 select HAVE_DEBUG_KMEMLEAK
6471b825 167 select HAVE_DMA_CONTIGUOUS
677aa9f7 168 select HAVE_DYNAMIC_FTRACE
06aeaaea 169 select HAVE_DYNAMIC_FTRACE_WITH_REGS
562955fe 170 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
03f5781b 171 select HAVE_EBPF_JIT
58340a07 172 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 173 select HAVE_EISA
5f56a5df 174 select HAVE_EXIT_THREAD
67a929e0 175 select HAVE_FAST_GUP
644e0e8d 176 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 177 select HAVE_FTRACE_MCOUNT_RECORD
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178 select HAVE_FUNCTION_GRAPH_TRACER
179 select HAVE_FUNCTION_TRACER
6b90bd4b 180 select HAVE_GCC_PLUGINS
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181 select HAVE_HW_BREAKPOINT
182 select HAVE_IDE
183 select HAVE_IOREMAP_PROT
6471b825 184 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 185 select HAVE_KERNEL_BZIP2
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IM
186 select HAVE_KERNEL_GZIP
187 select HAVE_KERNEL_LZ4
2e9f3bdd 188 select HAVE_KERNEL_LZMA
13510997 189 select HAVE_KERNEL_LZO
6471b825 190 select HAVE_KERNEL_XZ
fb46d057 191 select HAVE_KERNEL_ZSTD
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192 select HAVE_KPROBES
193 select HAVE_KPROBES_ON_FTRACE
540adea3 194 select HAVE_FUNCTION_ERROR_INJECTION
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195 select HAVE_KRETPROBES
196 select HAVE_KVM
197 select HAVE_LIVEPATCH if X86_64
0102752e 198 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 199 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 200 select HAVE_MOVE_PMD
42a0bb3f 201 select HAVE_NMI
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202 select HAVE_OPROFILE
203 select HAVE_OPTPROBES
204 select HAVE_PCSPKR_PLATFORM
205 select HAVE_PERF_EVENTS
c01d4323 206 select HAVE_PERF_EVENTS_NMI
92e5aae4 207 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 208 select HAVE_PCI
c5e63197 209 select HAVE_PERF_REGS
c5ebcedb 210 select HAVE_PERF_USER_STACK_DUMP
ff2e6d72 211 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
00998085 212 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
6471b825 213 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 214 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 215 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 216 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 217 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 218 select HAVE_RSEQ
6471b825 219 select HAVE_SYSCALL_TRACEPOINTS
6471b825 220 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 221 select HAVE_USER_RETURN_NOTIFIER
7ac87074 222 select HAVE_GENERIC_VDSO
05736e4a 223 select HOTPLUG_SMT if SMP
c0185808 224 select IRQ_FORCED_THREADING
86596f0a 225 select NEED_SG_DMA_LENGTH
2eac9c2d 226 select PCI_DOMAINS if PCI
625210cf 227 select PCI_LOCKLESS_CONFIG if PCI
6471b825 228 select PERF_EVENTS
3195ef59 229 select RTC_LIB
d6faca40 230 select RTC_MC146818_LIB
6471b825 231 select SPARSE_IRQ
83fe27ea 232 select SRCU
6471b825 233 select SYSCTL_EXCEPTION_TRACE
15f4eae7 234 select THREAD_INFO_IN_TASK
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IM
235 select USER_STACKTRACE_SUPPORT
236 select VIRT_TO_BUS
3b02a051 237 select HAVE_ARCH_KCSAN if X86_64
6471b825 238 select X86_FEATURE_NAMES if PROC_FS
0c608dad 239 select PROC_PID_ARCH_STATUS if PROC_FS
9e2b4be3 240 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
7d8330a5 241
ba7e4d13 242config INSTRUCTION_DECODER
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JB
243 def_bool y
244 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 245
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LT
246config OUTPUT_FORMAT
247 string
248 default "elf32-i386" if X86_32
249 default "elf64-x86-64" if X86_64
250
8d5fffb9 251config LOCKDEP_SUPPORT
3c2362e6 252 def_bool y
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SR
253
254config STACKTRACE_SUPPORT
3c2362e6 255 def_bool y
8d5fffb9 256
8d5fffb9 257config MMU
3c2362e6 258 def_bool y
8d5fffb9 259
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DC
260config ARCH_MMAP_RND_BITS_MIN
261 default 28 if 64BIT
262 default 8
263
264config ARCH_MMAP_RND_BITS_MAX
265 default 32 if 64BIT
266 default 16
267
268config ARCH_MMAP_RND_COMPAT_BITS_MIN
269 default 8
270
271config ARCH_MMAP_RND_COMPAT_BITS_MAX
272 default 16
273
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SR
274config SBUS
275 bool
276
277config GENERIC_ISA_DMA
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JB
278 def_bool y
279 depends on ISA_DMA_API
8d5fffb9 280
8d5fffb9 281config GENERIC_BUG
3c2362e6 282 def_bool y
8d5fffb9 283 depends on BUG
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JB
284 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
285
286config GENERIC_BUG_RELATIVE_POINTERS
287 bool
8d5fffb9 288
8d5fffb9 289config ARCH_MAY_HAVE_PC_FDC
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JB
290 def_bool y
291 depends on ISA_DMA_API
8d5fffb9 292
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SR
293config GENERIC_CALIBRATE_DELAY
294 def_bool y
295
9a0b8415 296config ARCH_HAS_CPU_RELAX
297 def_bool y
298
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299config ARCH_HAS_CACHE_LINE_SIZE
300 def_bool y
301
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DH
302config ARCH_HAS_FILTER_PGPROT
303 def_bool y
304
dd5af90a 305config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 306 def_bool y
b32ef636 307
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TH
308config NEED_PER_CPU_EMBED_FIRST_CHUNK
309 def_bool y
310
311config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
312 def_bool y
313
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JB
314config ARCH_HIBERNATION_POSSIBLE
315 def_bool y
801e4062 316
f4cb5700
JB
317config ARCH_SUSPEND_POSSIBLE
318 def_bool y
f4cb5700 319
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SC
320config ARCH_WANT_GENERAL_HUGETLB
321 def_bool y
322
8d5fffb9 323config ZONE_DMA32
e0fd24a3 324 def_bool y if X86_64
8d5fffb9 325
8d5fffb9 326config AUDIT_ARCH
e0fd24a3 327 def_bool y if X86_64
8d5fffb9 328
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AM
329config ARCH_SUPPORTS_DEBUG_PAGEALLOC
330 def_bool y
331
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332config KASAN_SHADOW_OFFSET
333 hex
334 depends on KASAN
335 default 0xdffffc0000000000
336
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337config HAVE_INTEL_TXT
338 def_bool y
6ea30386 339 depends on INTEL_IOMMU && ACPI
69575d38 340
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SR
341config X86_32_SMP
342 def_bool y
343 depends on X86_32 && SMP
344
345config X86_64_SMP
346 def_bool y
347 depends on X86_64 && SMP
348
ccbeed3a
TH
349config X86_32_LAZY_GS
350 def_bool y
8458f8c2 351 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 352
2b144498
SD
353config ARCH_SUPPORTS_UPROBES
354 def_bool y
355
d20642f0
RH
356config FIX_EARLYCON_MEM
357 def_bool y
358
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KS
359config DYNAMIC_PHYSICAL_MASK
360 bool
361
98233368
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362config PGTABLE_LEVELS
363 int
77ef56e4 364 default 5 if X86_5LEVEL
98233368
KS
365 default 4 if X86_64
366 default 3 if X86_PAE
367 default 2
368
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MY
369config CC_HAS_SANE_STACKPROTECTOR
370 bool
371 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
372 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
373 help
374 We have to make sure stack protector is unconditionally disabled if
375 the compiler produces broken code.
376
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SR
377menu "Processor type and features"
378
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RD
379config ZONE_DMA
380 bool "DMA memory allocation support" if EXPERT
381 default y
382 help
383 DMA memory allocation support allows devices with less than 32-bit
384 addressing to allocate within the first 16MB of address space.
385 Disable if no such devices will be used.
386
387 If unsure, say Y.
388
506f1d07
SR
389config SMP
390 bool "Symmetric multi-processing support"
a7f7f624 391 help
506f1d07 392 This enables support for systems with more than one CPU. If you have
4a474157
RG
393 a system with only one CPU, say N. If you have a system with more
394 than one CPU, say Y.
506f1d07 395
4a474157 396 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
397 machines, but will use only one CPU of a multiprocessor machine. If
398 you say Y here, the kernel will run on many, but not all,
4a474157 399 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
400 will run faster if you say N here.
401
402 Note that if you say Y here and choose architecture "586" or
403 "Pentium" under "Processor family", the kernel will not work on 486
404 architectures. Similarly, multiprocessor kernels for the "PPro"
405 architecture may not work on all Pentium based boards.
406
407 People using multiprocessor machines who say Y here should also say
408 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
409 Management" code will be disabled if you say Y here.
410
cb1aaebe 411 See also <file:Documentation/x86/i386/IO-APIC.rst>,
4f4cfa6c 412 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
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SR
413 <http://www.tldp.org/docs.html#howto>.
414
415 If you don't know what to do here, say N.
416
9def39be
JT
417config X86_FEATURE_NAMES
418 bool "Processor feature human-readable names" if EMBEDDED
419 default y
a7f7f624 420 help
9def39be
JT
421 This option compiles in a table of x86 feature bits and corresponding
422 names. This is required to support /proc/cpuinfo and a few kernel
423 messages. You can disable this to save space, at the expense of
424 making those few kernel messages show numeric feature bits instead.
425
426 If in doubt, say Y.
427
06cd9a7d
YL
428config X86_X2APIC
429 bool "Support x2apic"
19e3d60d 430 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
a7f7f624 431 help
06cd9a7d
YL
432 This enables x2apic support on CPUs that have this feature.
433
434 This allows 32-bit apic IDs (so it can support very large systems),
435 and accesses the local apic via MSRs not via mmio.
436
06cd9a7d
YL
437 If you don't know what to do here, say N.
438
6695c85b 439config X86_MPPARSE
6e87f9b7 440 bool "Enable MPS table" if ACPI || SFI
7a527688 441 default y
5ab74722 442 depends on X86_LOCAL_APIC
a7f7f624 443 help
6695c85b
YL
444 For old smp systems that do not have proper acpi support. Newer systems
445 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 446
ddd70cf9 447config GOLDFISH
b03b016f
KK
448 def_bool y
449 depends on X86_GOLDFISH
ddd70cf9 450
76b04384
DW
451config RETPOLINE
452 bool "Avoid speculative indirect branches in kernel"
453 default y
d5028ba8 454 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
455 help
456 Compile kernel with the retpoline compiler options to guard against
457 kernel-to-user data leaks by avoiding speculative indirect
458 branches. Requires a compiler with -mindirect-branch=thunk-extern
459 support for full protection. The kernel may run slower.
460
e6d42931
JW
461config X86_CPU_RESCTRL
462 bool "x86 CPU resource control support"
6fe07ce3 463 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 464 select KERNFS
e79f15a4 465 select PROC_CPU_RESCTRL if PROC_FS
78e99b4a 466 help
e6d42931 467 Enable x86 CPU resource control support.
6fe07ce3
BM
468
469 Provide support for the allocation and monitoring of system resources
470 usage by the CPU.
471
472 Intel calls this Intel Resource Director Technology
473 (Intel(R) RDT). More information about RDT can be found in the
474 Intel x86 Architecture Software Developer Manual.
475
476 AMD calls this AMD Platform Quality of Service (AMD QoS).
477 More information about AMD QoS can be found in the AMD64 Technology
478 Platform Quality of Service Extensions manual.
78e99b4a
FY
479
480 Say N if unsure.
481
8425091f 482if X86_32
a0d0bb4d
RD
483config X86_BIGSMP
484 bool "Support for big SMP systems with more than 8 CPUs"
485 depends on SMP
a7f7f624 486 help
e133f6ea 487 This option is needed for the systems that have more than 8 CPUs.
a0d0bb4d 488
c5c606d9
RT
489config X86_EXTENDED_PLATFORM
490 bool "Support for extended (non-PC) x86 platforms"
491 default y
a7f7f624 492 help
06ac8346
IM
493 If you disable this option then the kernel will only support
494 standard PC platforms. (which covers the vast majority of
495 systems out there.)
496
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RT
497 If you enable this option then you'll be able to select support
498 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 499 Goldfish (Android emulator)
8425091f 500 AMD Elan
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RT
501 RDC R-321x SoC
502 SGI 320/540 (Visual Workstation)
83125a3a 503 STA2X11-based (e.g. Northville)
3f4110a4 504 Moorestown MID devices
06ac8346
IM
505
506 If you have one of these systems, or if you want to build a
507 generic distribution kernel, say Y here - otherwise say N.
8425091f 508endif
06ac8346 509
8425091f
RT
510if X86_64
511config X86_EXTENDED_PLATFORM
512 bool "Support for extended (non-PC) x86 platforms"
513 default y
a7f7f624 514 help
8425091f
RT
515 If you disable this option then the kernel will only support
516 standard PC platforms. (which covers the vast majority of
517 systems out there.)
518
519 If you enable this option then you'll be able to select support
520 for the following (non-PC) 64 bit x86 platforms:
44b111b5 521 Numascale NumaChip
8425091f
RT
522 ScaleMP vSMP
523 SGI Ultraviolet
524
525 If you have one of these systems, or if you want to build a
526 generic distribution kernel, say Y here - otherwise say N.
527endif
c5c606d9
RT
528# This is an alphabetically sorted list of 64 bit extended platforms
529# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
530config X86_NUMACHIP
531 bool "Numascale NumaChip"
532 depends on X86_64
533 depends on X86_EXTENDED_PLATFORM
534 depends on NUMA
535 depends on SMP
536 depends on X86_X2APIC
f9726bfd 537 depends on PCI_MMCONFIG
a7f7f624 538 help
44b111b5
SP
539 Adds support for Numascale NumaChip large-SMP systems. Needed to
540 enable more than ~168 cores.
541 If you don't have one of these, you should say N here.
506f1d07 542
c5c606d9
RT
543config X86_VSMP
544 bool "ScaleMP vSMP"
6276a074 545 select HYPERVISOR_GUEST
c5c606d9
RT
546 select PARAVIRT
547 depends on X86_64 && PCI
548 depends on X86_EXTENDED_PLATFORM
ead91d4b 549 depends on SMP
a7f7f624 550 help
c5c606d9
RT
551 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
552 supposed to run on these EM64T-based machines. Only choose this option
553 if you have one of these machines.
5e3a77e9 554
03b48632
NP
555config X86_UV
556 bool "SGI Ultraviolet"
557 depends on X86_64
c5c606d9 558 depends on X86_EXTENDED_PLATFORM
54c28d29 559 depends on NUMA
1ecb4ae5 560 depends on EFI
9d6c26e7 561 depends on X86_X2APIC
1222e564 562 depends on PCI
a7f7f624 563 help
03b48632
NP
564 This option is needed in order to support SGI Ultraviolet systems.
565 If you don't have one of these, you should say N here.
566
c5c606d9
RT
567# Following is an alphabetically sorted list of 32 bit extended platforms
568# Please maintain the alphabetic order if and when there are additions
506f1d07 569
ddd70cf9 570config X86_GOLDFISH
b03b016f
KK
571 bool "Goldfish (Virtual Platform)"
572 depends on X86_EXTENDED_PLATFORM
a7f7f624 573 help
ddd70cf9
JN
574 Enable support for the Goldfish virtual platform used primarily
575 for Android development. Unless you are building for the Android
576 Goldfish emulator say N here.
577
c751e17b
TG
578config X86_INTEL_CE
579 bool "CE4100 TV platform"
580 depends on PCI
581 depends on PCI_GODIRECT
6084a6e2 582 depends on X86_IO_APIC
c751e17b
TG
583 depends on X86_32
584 depends on X86_EXTENDED_PLATFORM
37bc9f50 585 select X86_REBOOTFIXUPS
da6b737b
SAS
586 select OF
587 select OF_EARLY_FLATTREE
a7f7f624 588 help
c751e17b
TG
589 Select for the Intel CE media processor (CE4100) SOC.
590 This option compiles in support for the CE4100 SOC for settop
591 boxes and media devices.
592
4cb9b00f 593config X86_INTEL_MID
43605ef1 594 bool "Intel MID platform support"
43605ef1 595 depends on X86_EXTENDED_PLATFORM
edc6bc78 596 depends on X86_PLATFORM_DEVICES
1ea7c673 597 depends on PCI
3fda5bb4 598 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 599 depends on X86_IO_APIC
7c9c3a1e 600 select SFI
4cb9b00f 601 select I2C
7c9c3a1e 602 select DW_APB_TIMER
1ea7c673 603 select APB_TIMER
54b34aa0 604 select INTEL_SCU_PCI
15a713df 605 select MFD_INTEL_MSIC
a7f7f624 606 help
4cb9b00f
DC
607 Select to build a kernel capable of supporting Intel MID (Mobile
608 Internet Device) platform systems which do not have the PCI legacy
609 interfaces. If you are building for a PC class system say N here.
1ea7c673 610
4cb9b00f
DC
611 Intel MID platforms are based on an Intel processor and chipset which
612 consume less power than most of the x86 derivatives.
43605ef1 613
8bbc2a13
BD
614config X86_INTEL_QUARK
615 bool "Intel Quark platform support"
616 depends on X86_32
617 depends on X86_EXTENDED_PLATFORM
618 depends on X86_PLATFORM_DEVICES
619 depends on X86_TSC
620 depends on PCI
621 depends on PCI_GOANY
622 depends on X86_IO_APIC
623 select IOSF_MBI
624 select INTEL_IMR
9ab6eb51 625 select COMMON_CLK
a7f7f624 626 help
8bbc2a13
BD
627 Select to include support for Quark X1000 SoC.
628 Say Y here if you have a Quark based system such as the Arduino
629 compatible Intel Galileo.
630
3d48aab1
MW
631config X86_INTEL_LPSS
632 bool "Intel Low Power Subsystem Support"
5962dd22 633 depends on X86 && ACPI && PCI
3d48aab1 634 select COMMON_CLK
0f531431 635 select PINCTRL
eebb3e8d 636 select IOSF_MBI
a7f7f624 637 help
3d48aab1
MW
638 Select to build support for Intel Low Power Subsystem such as
639 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
640 things like clock tree (common clock framework) and pincontrol
641 which are needed by the LPSS peripheral drivers.
3d48aab1 642
92082a88
KX
643config X86_AMD_PLATFORM_DEVICE
644 bool "AMD ACPI2Platform devices support"
645 depends on ACPI
646 select COMMON_CLK
647 select PINCTRL
a7f7f624 648 help
92082a88
KX
649 Select to interpret AMD specific ACPI device to platform device
650 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
651 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
652 implemented under PINCTRL subsystem.
653
ced3ce76
DB
654config IOSF_MBI
655 tristate "Intel SoC IOSF Sideband support for SoC platforms"
656 depends on PCI
a7f7f624 657 help
ced3ce76
DB
658 This option enables sideband register access support for Intel SoC
659 platforms. On these platforms the IOSF sideband is used in lieu of
660 MSR's for some register accesses, mostly but not limited to thermal
661 and power. Drivers may query the availability of this device to
662 determine if they need the sideband in order to work on these
663 platforms. The sideband is available on the following SoC products.
664 This list is not meant to be exclusive.
665 - BayTrail
666 - Braswell
667 - Quark
668
669 You should say Y if you are running a kernel on one of these SoC's.
670
ed2226bd
DB
671config IOSF_MBI_DEBUG
672 bool "Enable IOSF sideband access through debugfs"
673 depends on IOSF_MBI && DEBUG_FS
a7f7f624 674 help
ed2226bd
DB
675 Select this option to expose the IOSF sideband access registers (MCR,
676 MDR, MCRX) through debugfs to write and read register information from
677 different units on the SoC. This is most useful for obtaining device
678 state information for debug and analysis. As this is a general access
679 mechanism, users of this option would have specific knowledge of the
680 device they want to access.
681
682 If you don't require the option or are in doubt, say N.
683
c5c606d9
RT
684config X86_RDC321X
685 bool "RDC R-321x SoC"
506f1d07 686 depends on X86_32
c5c606d9
RT
687 depends on X86_EXTENDED_PLATFORM
688 select M486
689 select X86_REBOOTFIXUPS
a7f7f624 690 help
c5c606d9
RT
691 This option is needed for RDC R-321x system-on-chip, also known
692 as R-8610-(G).
693 If you don't have one of these chips, you should say N here.
694
e0c7ae37 695config X86_32_NON_STANDARD
9c398017
IM
696 bool "Support non-standard 32-bit SMP architectures"
697 depends on X86_32 && SMP
c5c606d9 698 depends on X86_EXTENDED_PLATFORM
a7f7f624 699 help
b5660ba7
PA
700 This option compiles in the bigsmp and STA2X11 default
701 subarchitectures. It is intended for a generic binary
702 kernel. If you select them all, kernel will probe it one by
703 one and will fallback to default.
d49c4288 704
c5c606d9 705# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 706
d949f36f 707config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 708 def_bool y
d949f36f
LT
709 # MCE code calls memory_failure():
710 depends on X86_MCE
711 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
712 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
713 depends on X86_64 || !SPARSEMEM
714 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 715
83125a3a
AR
716config STA2X11
717 bool "STA2X11 Companion Chip Support"
718 depends on X86_32_NON_STANDARD && PCI
83125a3a
AR
719 select SWIOTLB
720 select MFD_STA2X11
0145071b 721 select GPIOLIB
a7f7f624 722 help
83125a3a
AR
723 This adds support for boards based on the STA2X11 IO-Hub,
724 a.k.a. "ConneXt". The chip is used in place of the standard
725 PC chipset, so all "standard" peripherals are missing. If this
726 option is selected the kernel will still be able to boot on
727 standard PC machines.
728
82148d1d
S
729config X86_32_IRIS
730 tristate "Eurobraille/Iris poweroff module"
731 depends on X86_32
a7f7f624 732 help
82148d1d
S
733 The Iris machines from EuroBraille do not have APM or ACPI support
734 to shut themselves down properly. A special I/O sequence is
735 needed to do so, which is what this module does at
736 kernel shutdown.
737
738 This is only for Iris machines from EuroBraille.
739
740 If unused, say N.
741
ae1e9130 742config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
743 def_bool y
744 prompt "Single-depth WCHAN output"
a87d0914 745 depends on X86
a7f7f624 746 help
506f1d07
SR
747 Calculate simpler /proc/<PID>/wchan values. If this option
748 is disabled then wchan values will recurse back to the
749 caller function. This provides more accurate wchan values,
750 at the expense of slightly more scheduling overhead.
751
752 If in doubt, say "Y".
753
6276a074
BP
754menuconfig HYPERVISOR_GUEST
755 bool "Linux guest support"
a7f7f624 756 help
6276a074
BP
757 Say Y here to enable options for running Linux under various hyper-
758 visors. This option enables basic hypervisor detection and platform
759 setup.
506f1d07 760
6276a074
BP
761 If you say N, all options in this submenu will be skipped and
762 disabled, and Linux guest support won't be built in.
506f1d07 763
6276a074 764if HYPERVISOR_GUEST
506f1d07 765
e61bd94a
EPH
766config PARAVIRT
767 bool "Enable paravirtualization code"
a7f7f624 768 help
e61bd94a
EPH
769 This changes the kernel so it can modify itself when it is run
770 under a hypervisor, potentially improving performance significantly
771 over full virtualization. However, when run without a hypervisor
772 the kernel is theoretically slower and slightly larger.
773
c00a280a
JG
774config PARAVIRT_XXL
775 bool
776
6276a074
BP
777config PARAVIRT_DEBUG
778 bool "paravirt-ops debugging"
779 depends on PARAVIRT && DEBUG_KERNEL
a7f7f624 780 help
6276a074
BP
781 Enable to debug paravirt_ops internals. Specifically, BUG if
782 a paravirt_op is missing when it is called.
783
b4ecc126
JF
784config PARAVIRT_SPINLOCKS
785 bool "Paravirtualization layer for spinlocks"
6ea30386 786 depends on PARAVIRT && SMP
a7f7f624 787 help
b4ecc126
JF
788 Paravirtualized spinlocks allow a pvops backend to replace the
789 spinlock implementation with something virtualization-friendly
790 (for example, block the virtual CPU rather than spinning).
791
4c4e4f61
R
792 It has a minimal impact on native kernels and gives a nice performance
793 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 794
4c4e4f61 795 If you are unsure how to answer this question, answer Y.
b4ecc126 796
ecca2502
ZY
797config X86_HV_CALLBACK_VECTOR
798 def_bool n
799
6276a074 800source "arch/x86/xen/Kconfig"
7af192c9 801
6276a074
BP
802config KVM_GUEST
803 bool "KVM Guest support (including kvmclock)"
804 depends on PARAVIRT
805 select PARAVIRT_CLOCK
a1c4423b 806 select ARCH_CPUIDLE_HALTPOLL
b1d40575 807 select X86_HV_CALLBACK_VECTOR
6276a074 808 default y
a7f7f624 809 help
6276a074
BP
810 This option enables various optimizations for running under the KVM
811 hypervisor. It includes a paravirtualized clock, so that instead
812 of relying on a PIT (or probably other) emulation by the
813 underlying device model, the host provides the guest with
814 timing infrastructure such as time of day, and system time
506f1d07 815
a1c4423b 816config ARCH_CPUIDLE_HALTPOLL
b03b016f
KK
817 def_bool n
818 prompt "Disable host haltpoll when loading haltpoll driver"
819 help
a1c4423b
MT
820 If virtualized under KVM, disable host haltpoll.
821
7733607f
MW
822config PVH
823 bool "Support for running PVH guests"
a7f7f624 824 help
7733607f
MW
825 This option enables the PVH entry point for guest virtual machines
826 as specified in the x86/HVM direct boot ABI.
827
6276a074
BP
828config PARAVIRT_TIME_ACCOUNTING
829 bool "Paravirtual steal time accounting"
830 depends on PARAVIRT
a7f7f624 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
a7f7f624 846 help
4a362601
JK
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
a7f7f624 869 help
8f9ca475
IM
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
b03b016f
KK
890 def_bool y if X86_INTEL_MID
891 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
892 select DW_APB_TIMER
893 depends on X86_INTEL_MID && SFI
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.
bb24c471 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
a7f7f624 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"
2f9237d4 915 select DMA_OPS
a4ce5a48 916 select IOMMU_HELPER
506f1d07 917 select SWIOTLB
23ac4ae8 918 depends on X86_64 && PCI && AMD_NB
a7f7f624 919 help
ced3c42c
IM
920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921 GART based hardware IOMMUs.
922
923 The GART supports full DMA access for devices with 32-bit access
924 limitations, on systems with more than 3 GB. This is usually needed
925 for USB, sound, many IDE/SATA chipsets and some other devices.
926
927 Newer systems typically have a modern AMD IOMMU, supported via
928 the CONFIG_AMD_IOMMU=y config option.
929
930 In normal configurations this driver is only active when needed:
931 there's more than 3 GB of memory and the system contains a
932 32-bit limited device.
933
934 If unsure, say Y.
506f1d07 935
1184dc2f 936config MAXSMP
ddb0c5a6 937 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 938 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 939 select CPUMASK_OFFSTACK
a7f7f624 940 help
ddb0c5a6 941 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 942 If unsure, say N.
506f1d07 943
aec6487e
IM
944#
945# The maximum number of CPUs supported:
946#
947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948# and which can be configured interactively in the
949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950#
951# The ranges are different on 32-bit and 64-bit kernels, depending on
952# hardware capabilities and scalability features of the kernel.
953#
954# ( If MAXSMP is enabled we just use the highest possible value and disable
955# interactive configuration. )
956#
957
958config NR_CPUS_RANGE_BEGIN
a0d0bb4d 959 int
aec6487e
IM
960 default NR_CPUS_RANGE_END if MAXSMP
961 default 1 if !SMP
962 default 2
a0d0bb4d 963
aec6487e 964config NR_CPUS_RANGE_END
a0d0bb4d 965 int
aec6487e
IM
966 depends on X86_32
967 default 64 if SMP && X86_BIGSMP
968 default 8 if SMP && !X86_BIGSMP
969 default 1 if !SMP
a0d0bb4d 970
aec6487e 971config NR_CPUS_RANGE_END
a0d0bb4d 972 int
aec6487e 973 depends on X86_64
1edae1ae
SW
974 default 8192 if SMP && CPUMASK_OFFSTACK
975 default 512 if SMP && !CPUMASK_OFFSTACK
aec6487e 976 default 1 if !SMP
a0d0bb4d 977
aec6487e 978config NR_CPUS_DEFAULT
a0d0bb4d
RD
979 int
980 depends on X86_32
aec6487e
IM
981 default 32 if X86_BIGSMP
982 default 8 if SMP
983 default 1 if !SMP
a0d0bb4d 984
aec6487e 985config NR_CPUS_DEFAULT
a0d0bb4d
RD
986 int
987 depends on X86_64
aec6487e
IM
988 default 8192 if MAXSMP
989 default 64 if SMP
990 default 1 if !SMP
a0d0bb4d 991
506f1d07 992config NR_CPUS
36f5101a 993 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995 default NR_CPUS_DEFAULT
a7f7f624 996 help
506f1d07 997 This allows you to specify the maximum number of CPUs which this
bb61ccc7 998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 999 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
1000 minimum value which makes sense is 2.
1001
aec6487e
IM
1002 This is purely to save memory: each supported CPU adds about 8KB
1003 to the kernel image.
506f1d07
SR
1004
1005config SCHED_SMT
dbe73364 1006 def_bool y if SMP
506f1d07
SR
1007
1008config SCHED_MC
3c2362e6
HH
1009 def_bool y
1010 prompt "Multi-core scheduler support"
c8e56d20 1011 depends on SMP
a7f7f624 1012 help
506f1d07
SR
1013 Multi-core scheduler support improves the CPU scheduler's decision
1014 making when dealing with multi-core CPU chips at a cost of slightly
1015 increased overhead in some places. If unsure say N here.
1016
de966cf4
TC
1017config SCHED_MC_PRIO
1018 bool "CPU core priorities scheduler support"
0a21fc12
IM
1019 depends on SCHED_MC && CPU_SUP_INTEL
1020 select X86_INTEL_PSTATE
1021 select CPU_FREQ
de966cf4 1022 default y
a7f7f624 1023 help
0a21fc12
IM
1024 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025 core ordering determined at manufacturing time, which allows
1026 certain cores to reach higher turbo frequencies (when running
1027 single threaded workloads) than others.
de966cf4 1028
0a21fc12
IM
1029 Enabling this kernel feature teaches the scheduler about
1030 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031 scheduler's CPU selection logic accordingly, so that higher
1032 overall system performance can be achieved.
de966cf4 1033
0a21fc12 1034 This feature will have no effect on CPUs without this feature.
de966cf4 1035
0a21fc12 1036 If unsure say Y here.
5e76b2ab 1037
30b8b006 1038config UP_LATE_INIT
b03b016f
KK
1039 def_bool y
1040 depends on !SMP && X86_LOCAL_APIC
30b8b006 1041
506f1d07 1042config X86_UP_APIC
50849eef
JB
1043 bool "Local APIC support on uniprocessors" if !PCI_MSI
1044 default PCI_MSI
38a1dfda 1045 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
a7f7f624 1046 help
506f1d07
SR
1047 A local APIC (Advanced Programmable Interrupt Controller) is an
1048 integrated interrupt controller in the CPU. If you have a single-CPU
1049 system which has a processor with a local APIC, you can say Y here to
1050 enable and use it. If you say Y here even though your machine doesn't
1051 have a local APIC, then the kernel will still run with no slowdown at
1052 all. The local APIC supports CPU-generated self-interrupts (timer,
1053 performance counters), and the NMI watchdog which detects hard
1054 lockups.
1055
1056config X86_UP_IOAPIC
1057 bool "IO-APIC support on uniprocessors"
1058 depends on X86_UP_APIC
a7f7f624 1059 help
506f1d07
SR
1060 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061 SMP-capable replacement for PC-style interrupt controllers. Most
1062 SMP systems and many recent uniprocessor systems have one.
1063
1064 If you have a single-CPU system with an IO-APIC, you can say Y here
1065 to use it. If you say Y here even though your machine doesn't have
1066 an IO-APIC, then the kernel will still run with no slowdown at all.
1067
1068config X86_LOCAL_APIC
3c2362e6 1069 def_bool y
0dbc6078 1070 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1071 select IRQ_DOMAIN_HIERARCHY
52f518a3 1072 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1073
1074config X86_IO_APIC
b1da1e71
JB
1075 def_bool y
1076 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1077
41b9eb26
SA
1078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1079 bool "Reroute for broken boot IRQs"
41b9eb26 1080 depends on X86_IO_APIC
a7f7f624 1081 help
41b9eb26
SA
1082 This option enables a workaround that fixes a source of
1083 spurious interrupts. This is recommended when threaded
1084 interrupt handling is used on systems where the generation of
1085 superfluous "boot interrupts" cannot be disabled.
1086
1087 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1088 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1089 kernel does during interrupt handling). On chipsets where this
1090 boot IRQ generation cannot be disabled, this workaround keeps
1091 the original IRQ line masked so that only the equivalent "boot
1092 IRQ" is delivered to the CPUs. The workaround also tells the
1093 kernel to set up the IRQ handler on the boot IRQ line. In this
1094 way only one interrupt is delivered to the kernel. Otherwise
1095 the spurious second interrupt may cause the kernel to bring
1096 down (vital) interrupt lines.
1097
1098 Only affects "broken" chipsets. Interrupt sharing may be
1099 increased on these systems.
1100
506f1d07 1101config X86_MCE
bab9bc65 1102 bool "Machine Check / overheating reporting"
648ed940 1103 select GENERIC_ALLOCATOR
e57dbaf7 1104 default y
a7f7f624 1105 help
bab9bc65
AK
1106 Machine Check support allows the processor to notify the
1107 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1108 The action the kernel takes depends on the severity of the problem,
bab9bc65 1109 ranging from warning messages to halting the machine.
4efc0670 1110
5de97c9f
TL
1111config X86_MCELOG_LEGACY
1112 bool "Support for deprecated /dev/mcelog character device"
1113 depends on X86_MCE
a7f7f624 1114 help
5de97c9f
TL
1115 Enable support for /dev/mcelog which is needed by the old mcelog
1116 userspace logging daemon. Consider switching to the new generation
1117 rasdaemon solution.
1118
506f1d07 1119config X86_MCE_INTEL
3c2362e6
HH
1120 def_bool y
1121 prompt "Intel MCE features"
c1ebf835 1122 depends on X86_MCE && X86_LOCAL_APIC
a7f7f624 1123 help
506f1d07
SR
1124 Additional support for intel specific MCE features such as
1125 the thermal monitor.
1126
1127config X86_MCE_AMD
3c2362e6
HH
1128 def_bool y
1129 prompt "AMD MCE features"
f5382de9 1130 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
a7f7f624 1131 help
506f1d07
SR
1132 Additional support for AMD specific MCE features such as
1133 the DRAM Error Threshold.
1134
4efc0670 1135config X86_ANCIENT_MCE
6fc108a0 1136 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1137 depends on X86_32 && X86_MCE
a7f7f624 1138 help
cd13adcc 1139 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1140 systems. These typically need to be enabled explicitly on the command
cd13adcc 1141 line.
4efc0670 1142
b2762686
AK
1143config X86_MCE_THRESHOLD
1144 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1145 def_bool y
b2762686 1146
ea149b36 1147config X86_MCE_INJECT
bc8e80d5 1148 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36 1149 tristate "Machine check injector support"
a7f7f624 1150 help
ea149b36
AK
1151 Provide support for injecting machine checks for testing purposes.
1152 If you don't know what a machine check is and you don't do kernel
1153 QA it is safe to say n.
1154
4efc0670
AK
1155config X86_THERMAL_VECTOR
1156 def_bool y
5bb38adc 1157 depends on X86_MCE_INTEL
4efc0670 1158
07dc900e 1159source "arch/x86/events/Kconfig"
e633c65a 1160
5aef51c3 1161config X86_LEGACY_VM86
1e642812 1162 bool "Legacy VM86 support"
506f1d07 1163 depends on X86_32
a7f7f624 1164 help
5aef51c3
AL
1165 This option allows user programs to put the CPU into V8086
1166 mode, which is an 80286-era approximation of 16-bit real mode.
1167
1168 Some very old versions of X and/or vbetool require this option
1169 for user mode setting. Similarly, DOSEMU will use it if
1170 available to accelerate real mode DOS programs. However, any
1171 recent version of DOSEMU, X, or vbetool should be fully
1172 functional even without kernel VM86 support, as they will all
1e642812
IM
1173 fall back to software emulation. Nevertheless, if you are using
1174 a 16-bit DOS program where 16-bit performance matters, vm86
1175 mode might be faster than emulation and you might want to
1176 enable this option.
5aef51c3 1177
1e642812
IM
1178 Note that any app that works on a 64-bit kernel is unlikely to
1179 need this option, as 64-bit kernels don't, and can't, support
1180 V8086 mode. This option is also unrelated to 16-bit protected
1181 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1182
1e642812
IM
1183 Enabling this option increases the complexity of the kernel
1184 and slows down exception handling a tiny bit.
5aef51c3 1185
1e642812 1186 If unsure, say N here.
5aef51c3
AL
1187
1188config VM86
b03b016f
KK
1189 bool
1190 default X86_LEGACY_VM86
34273f41
PA
1191
1192config X86_16BIT
1193 bool "Enable support for 16-bit segments" if EXPERT
1194 default y
a5b9e5a2 1195 depends on MODIFY_LDT_SYSCALL
a7f7f624 1196 help
34273f41
PA
1197 This option is required by programs like Wine to run 16-bit
1198 protected mode legacy code on x86 processors. Disabling
1199 this option saves about 300 bytes on i386, or around 6K text
1200 plus 16K runtime memory on x86-64,
1201
1202config X86_ESPFIX32
1203 def_bool y
1204 depends on X86_16BIT && X86_32
506f1d07 1205
197725de
PA
1206config X86_ESPFIX64
1207 def_bool y
34273f41 1208 depends on X86_16BIT && X86_64
506f1d07 1209
1ad83c85 1210config X86_VSYSCALL_EMULATION
b03b016f
KK
1211 bool "Enable vsyscall emulation" if EXPERT
1212 default y
1213 depends on X86_64
a7f7f624 1214 help
1ad83c85
AL
1215 This enables emulation of the legacy vsyscall page. Disabling
1216 it is roughly equivalent to booting with vsyscall=none, except
1217 that it will also disable the helpful warning if a program
1218 tries to use a vsyscall. With this option set to N, offending
1219 programs will just segfault, citing addresses of the form
1220 0xffffffffff600?00.
1221
1222 This option is required by many programs built before 2013, and
1223 care should be used even with newer programs if set to N.
1224
1225 Disabling this option saves about 7K of kernel size and
1226 possibly 4K of additional runtime pagetable memory.
1227
111e7b15
TG
1228config X86_IOPL_IOPERM
1229 bool "IOPERM and IOPL Emulation"
a24ca997 1230 default y
a7f7f624 1231 help
111e7b15
TG
1232 This enables the ioperm() and iopl() syscalls which are necessary
1233 for legacy applications.
1234
c8137ace
TG
1235 Legacy IOPL support is an overbroad mechanism which allows user
1236 space aside of accessing all 65536 I/O ports also to disable
1237 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238 capabilities and permission from potentially active security
1239 modules.
1240
1241 The emulation restricts the functionality of the syscall to
1242 only allowing the full range I/O port access, but prevents the
a24ca997
TG
1243 ability to disable interrupts from user space which would be
1244 granted if the hardware IOPL mechanism would be used.
c8137ace 1245
506f1d07
SR
1246config TOSHIBA
1247 tristate "Toshiba Laptop support"
1248 depends on X86_32
a7f7f624 1249 help
506f1d07
SR
1250 This adds a driver to safely access the System Management Mode of
1251 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252 not work on models with a Phoenix BIOS. The System Management Mode
1253 is used to set the BIOS and power saving options on Toshiba portables.
1254
1255 For information on utilities to make use of this driver see the
1256 Toshiba Linux utilities web site at:
1257 <http://www.buzzard.org.uk/toshiba/>.
1258
1259 Say Y if you intend to run this kernel on a Toshiba portable.
1260 Say N otherwise.
1261
1262config I8K
039ae585 1263 tristate "Dell i8k legacy laptop support"
949a9d70 1264 select HWMON
039ae585 1265 select SENSORS_DELL_SMM
a7f7f624 1266 help
039ae585
PR
1267 This option enables legacy /proc/i8k userspace interface in hwmon
1268 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269 temperature and allows controlling fan speeds of Dell laptops via
1270 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271 it reports also power and hotkey status. For fan speed control is
1272 needed userspace package i8kutils.
1273
1274 Say Y if you intend to run this kernel on old Dell laptops or want to
1275 use userspace package i8kutils.
506f1d07
SR
1276 Say N otherwise.
1277
1278config X86_REBOOTFIXUPS
9ba16087
JB
1279 bool "Enable X86 board specific fixups for reboot"
1280 depends on X86_32
a7f7f624 1281 help
506f1d07
SR
1282 This enables chipset and/or board specific fixups to be done
1283 in order to get reboot to work correctly. This is only needed on
1284 some combinations of hardware and BIOS. The symptom, for which
1285 this config is intended, is when reboot ends with a stalled/hung
1286 system.
1287
1288 Currently, the only fixup is for the Geode machines using
5e3a77e9 1289 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1290
1291 Say Y if you want to enable the fixup. Currently, it's safe to
1292 enable this option even if you don't need it.
1293 Say N otherwise.
1294
1295config MICROCODE
9a2bc335
BP
1296 bool "CPU microcode loading support"
1297 default y
80030e3d 1298 depends on CPU_SUP_AMD || CPU_SUP_INTEL
a7f7f624 1299 help
506f1d07 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
a7f7f624 1320 help
8f9ca475
IM
1321 This options enables microcode patch loading support for Intel
1322 processors.
1323
b8989db9
A
1324 For the current Intel microcode data package go to
1325 <https://downloadcenter.intel.com> and search for
1326 'Linux Processor Microcode Data File'.
8d86f390 1327
80cc9f10 1328config MICROCODE_AMD
e43f6e67 1329 bool "AMD microcode loading support"
8f9ca475 1330 depends on MICROCODE
a7f7f624 1331 help
8f9ca475
IM
1332 If you select this option, microcode patch loading support for AMD
1333 processors will be enabled.
80cc9f10 1334
8f9ca475 1335config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1336 bool "Ancient loading interface (DEPRECATED)"
1337 default n
506f1d07 1338 depends on MICROCODE
a7f7f624 1339 help
c02f48e0
BP
1340 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1341 which was used by userspace tools like iucode_tool and microcode.ctl.
1342 It is inadequate because it runs too late to be able to properly
1343 load microcode on a machine and it needs special tools. Instead, you
1344 should've switched to the early loading method with the initrd or
cb1aaebe 1345 builtin microcode by now: Documentation/x86/microcode.rst
506f1d07
SR
1346
1347config X86_MSR
1348 tristate "/dev/cpu/*/msr - Model-specific register support"
a7f7f624 1349 help
506f1d07
SR
1350 This device gives privileged processes access to the x86
1351 Model-Specific Registers (MSRs). It is a character device with
1352 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1353 MSR accesses are directed to a specific CPU on multi-processor
1354 systems.
1355
1356config X86_CPUID
1357 tristate "/dev/cpu/*/cpuid - CPU information support"
a7f7f624 1358 help
506f1d07
SR
1359 This device gives processes access to the x86 CPUID instruction to
1360 be executed on a specific processor. It is a character device
1361 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1362 /dev/cpu/31/cpuid.
1363
1364choice
1365 prompt "High Memory Support"
6fc108a0 1366 default HIGHMEM4G
506f1d07
SR
1367 depends on X86_32
1368
1369config NOHIGHMEM
1370 bool "off"
a7f7f624 1371 help
506f1d07
SR
1372 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1373 However, the address space of 32-bit x86 processors is only 4
1374 Gigabytes large. That means that, if you have a large amount of
1375 physical memory, not all of it can be "permanently mapped" by the
1376 kernel. The physical memory that's not permanently mapped is called
1377 "high memory".
1378
1379 If you are compiling a kernel which will never run on a machine with
1380 more than 1 Gigabyte total physical RAM, answer "off" here (default
1381 choice and suitable for most users). This will result in a "3GB/1GB"
1382 split: 3GB are mapped so that each process sees a 3GB virtual memory
1383 space and the remaining part of the 4GB virtual memory space is used
1384 by the kernel to permanently map as much physical memory as
1385 possible.
1386
1387 If the machine has between 1 and 4 Gigabytes physical RAM, then
1388 answer "4GB" here.
1389
1390 If more than 4 Gigabytes is used then answer "64GB" here. This
1391 selection turns Intel PAE (Physical Address Extension) mode on.
1392 PAE implements 3-level paging on IA32 processors. PAE is fully
1393 supported by Linux, PAE mode is implemented on all recent Intel
1394 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1395 then the kernel will not boot on CPUs that don't support PAE!
1396
1397 The actual amount of total physical memory will either be
1398 auto detected or can be forced by using a kernel command line option
1399 such as "mem=256M". (Try "man bootparam" or see the documentation of
1400 your boot loader (lilo or loadlin) about how to pass options to the
1401 kernel at boot time.)
1402
1403 If unsure, say "off".
1404
1405config HIGHMEM4G
1406 bool "4GB"
a7f7f624 1407 help
506f1d07
SR
1408 Select this if you have a 32-bit processor and between 1 and 4
1409 gigabytes of physical RAM.
1410
1411config HIGHMEM64G
1412 bool "64GB"
69b8d3fc 1413 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1414 select X86_PAE
a7f7f624 1415 help
506f1d07
SR
1416 Select this if you have a 32-bit processor and more than 4
1417 gigabytes of physical RAM.
1418
1419endchoice
1420
1421choice
6a108a14 1422 prompt "Memory split" if EXPERT
506f1d07
SR
1423 default VMSPLIT_3G
1424 depends on X86_32
a7f7f624 1425 help
506f1d07
SR
1426 Select the desired split between kernel and user memory.
1427
1428 If the address range available to the kernel is less than the
1429 physical memory installed, the remaining memory will be available
1430 as "high memory". Accessing high memory is a little more costly
1431 than low memory, as it needs to be mapped into the kernel first.
1432 Note that increasing the kernel address space limits the range
1433 available to user programs, making the address space there
1434 tighter. Selecting anything other than the default 3G/1G split
1435 will also likely make your kernel incompatible with binary-only
1436 kernel modules.
1437
1438 If you are not absolutely sure what you are doing, leave this
1439 option alone!
1440
1441 config VMSPLIT_3G
1442 bool "3G/1G user/kernel split"
1443 config VMSPLIT_3G_OPT
1444 depends on !X86_PAE
1445 bool "3G/1G user/kernel split (for full 1G low memory)"
1446 config VMSPLIT_2G
1447 bool "2G/2G user/kernel split"
1448 config VMSPLIT_2G_OPT
1449 depends on !X86_PAE
1450 bool "2G/2G user/kernel split (for full 2G low memory)"
1451 config VMSPLIT_1G
1452 bool "1G/3G user/kernel split"
1453endchoice
1454
1455config PAGE_OFFSET
1456 hex
1457 default 0xB0000000 if VMSPLIT_3G_OPT
1458 default 0x80000000 if VMSPLIT_2G
1459 default 0x78000000 if VMSPLIT_2G_OPT
1460 default 0x40000000 if VMSPLIT_1G
1461 default 0xC0000000
1462 depends on X86_32
1463
1464config HIGHMEM
3c2362e6 1465 def_bool y
506f1d07 1466 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1467
1468config X86_PAE
9ba16087 1469 bool "PAE (Physical Address Extension) Support"
506f1d07 1470 depends on X86_32 && !HIGHMEM4G
d4a451d5 1471 select PHYS_ADDR_T_64BIT
9d99c712 1472 select SWIOTLB
a7f7f624 1473 help
506f1d07
SR
1474 PAE is required for NX support, and furthermore enables
1475 larger swapspace support for non-overcommit purposes. It
1476 has the cost of more pagetable lookup overhead, and also
1477 consumes more pagetable space per process.
1478
77ef56e4
KS
1479config X86_5LEVEL
1480 bool "Enable 5-level page tables support"
18ec1eaf 1481 default y
eedb92ab 1482 select DYNAMIC_MEMORY_LAYOUT
162434e7 1483 select SPARSEMEM_VMEMMAP
77ef56e4 1484 depends on X86_64
a7f7f624 1485 help
77ef56e4
KS
1486 5-level paging enables access to larger address space:
1487 upto 128 PiB of virtual address space and 4 PiB of
1488 physical address space.
1489
1490 It will be supported by future Intel CPUs.
1491
6657fca0
KS
1492 A kernel with the option enabled can be booted on machines that
1493 support 4- or 5-level paging.
77ef56e4 1494
cb1aaebe 1495 See Documentation/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1496 information.
1497
1498 Say N if unsure.
1499
10971ab2 1500config X86_DIRECT_GBPAGES
e5008abe 1501 def_bool y
2e1da13f 1502 depends on X86_64
a7f7f624 1503 help
10971ab2
IM
1504 Certain kernel features effectively disable kernel
1505 linear 1 GB mappings (even if the CPU otherwise
1506 supports them), so don't confuse the user by printing
1507 that we have them enabled.
9e899816 1508
5c280cf6
TG
1509config X86_CPA_STATISTICS
1510 bool "Enable statistic for Change Page Attribute"
1511 depends on DEBUG_FS
a7f7f624 1512 help
b75baaf3 1513 Expose statistics about the Change Page Attribute mechanism, which
a943245a 1514 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1515 page mappings when mapping protections are changed.
1516
7744ccdb
TL
1517config AMD_MEM_ENCRYPT
1518 bool "AMD Secure Memory Encryption (SME) support"
1519 depends on X86_64 && CPU_SUP_AMD
82fef0ad 1520 select DMA_COHERENT_POOL
94d49eb3 1521 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1522 select ARCH_USE_MEMREMAP_PROT
9087c375 1523 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
a7f7f624 1524 help
7744ccdb
TL
1525 Say yes to enable support for the encryption of system memory.
1526 This requires an AMD processor that supports Secure Memory
1527 Encryption (SME).
1528
1529config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1530 bool "Activate AMD Secure Memory Encryption (SME) by default"
1531 default y
1532 depends on AMD_MEM_ENCRYPT
a7f7f624 1533 help
7744ccdb
TL
1534 Say yes to have system memory encrypted by default if running on
1535 an AMD processor that supports Secure Memory Encryption (SME).
1536
1537 If set to Y, then the encryption of system memory can be
1538 deactivated with the mem_encrypt=off command line option.
1539
1540 If set to N, then the encryption of system memory can be
1541 activated with the mem_encrypt=on command line option.
1542
506f1d07
SR
1543# Common NUMA Features
1544config NUMA
e133f6ea 1545 bool "NUMA Memory Allocation and Scheduler Support"
506f1d07 1546 depends on SMP
b5660ba7
PA
1547 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1548 default y if X86_BIGSMP
a7f7f624 1549 help
e133f6ea 1550 Enable NUMA (Non-Uniform Memory Access) support.
fd51b2d7 1551
506f1d07
SR
1552 The kernel will try to allocate memory used by a CPU on the
1553 local memory controller of the CPU and add some more
1554 NUMA awareness to the kernel.
1555
c280ea5e 1556 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1557 (or later), AMD Opteron, or EM64T NUMA.
1558
b5660ba7 1559 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1560 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1561
1562 Otherwise, you should say N.
506f1d07 1563
eec1d4fa 1564config AMD_NUMA
3c2362e6
HH
1565 def_bool y
1566 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1567 depends on X86_64 && NUMA && PCI
a7f7f624 1568 help
eec1d4fa
HR
1569 Enable AMD NUMA node topology detection. You should say Y here if
1570 you have a multi processor AMD system. This uses an old method to
1571 read the NUMA configuration directly from the builtin Northbridge
1572 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1573 which also takes priority if both are compiled in.
506f1d07
SR
1574
1575config X86_64_ACPI_NUMA
3c2362e6
HH
1576 def_bool y
1577 prompt "ACPI NUMA detection"
506f1d07
SR
1578 depends on X86_64 && NUMA && ACPI && PCI
1579 select ACPI_NUMA
a7f7f624 1580 help
506f1d07
SR
1581 Enable ACPI SRAT based node topology detection.
1582
1583config NUMA_EMU
1584 bool "NUMA emulation"
1b7e03ef 1585 depends on NUMA
a7f7f624 1586 help
506f1d07
SR
1587 Enable NUMA emulation. A flat machine will be split
1588 into virtual nodes when booted with "numa=fake=N", where N is the
1589 number of nodes. This is only useful for debugging.
1590
1591config NODES_SHIFT
d25e26b6 1592 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1593 range 1 10
1594 default "10" if MAXSMP
506f1d07 1595 default "6" if X86_64
506f1d07
SR
1596 default "3"
1597 depends on NEED_MULTIPLE_NODES
a7f7f624 1598 help
1184dc2f 1599 Specify the maximum number of NUMA Nodes available on the target
692105b8 1600 system. Increases memory reserved to accommodate various tables.
506f1d07 1601
506f1d07
SR
1602config ARCH_FLATMEM_ENABLE
1603 def_bool y
3b16651f 1604 depends on X86_32 && !NUMA
506f1d07 1605
506f1d07
SR
1606config ARCH_SPARSEMEM_ENABLE
1607 def_bool y
6ea30386 1608 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1609 select SPARSEMEM_STATIC if X86_32
1610 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1611
3b16651f 1612config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1613 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1614
506f1d07
SR
1615config ARCH_SELECT_MEMORY_MODEL
1616 def_bool y
b263295d 1617 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1618
1619config ARCH_MEMORY_PROBE
a0842b70 1620 bool "Enable sysfs memory/probe interface"
3120e25e 1621 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1622 help
1623 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1624 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1625 If you are unsure how to answer this question, answer N.
506f1d07 1626
3b16651f
TH
1627config ARCH_PROC_KCORE_TEXT
1628 def_bool y
1629 depends on X86_64 && PROC_KCORE
1630
a29815a3 1631config ILLEGAL_POINTER_VALUE
b03b016f
KK
1632 hex
1633 default 0 if X86_32
1634 default 0xdead000000000000 if X86_64
a29815a3 1635
7a67832c
DW
1636config X86_PMEM_LEGACY_DEVICE
1637 bool
1638
ec776ef6 1639config X86_PMEM_LEGACY
7a67832c 1640 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1641 depends on PHYS_ADDR_T_64BIT
1642 depends on BLK_DEV
7a67832c 1643 select X86_PMEM_LEGACY_DEVICE
7b27a862 1644 select NUMA_KEEP_MEMINFO if NUMA
9f53f9fa 1645 select LIBNVDIMM
ec776ef6
CH
1646 help
1647 Treat memory marked using the non-standard e820 type of 12 as used
1648 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1649 The kernel will offer these regions to the 'pmem' driver so
1650 they can be used for persistent storage.
1651
1652 Say Y if unsure.
1653
506f1d07
SR
1654config HIGHPTE
1655 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1656 depends on HIGHMEM
a7f7f624 1657 help
506f1d07
SR
1658 The VM uses one page table entry for each page of physical memory.
1659 For systems with a lot of RAM, this can be wasteful of precious
1660 low memory. Setting this option will put user-space page table
1661 entries in high memory.
1662
9f077871 1663config X86_CHECK_BIOS_CORRUPTION
8f9ca475 1664 bool "Check for low memory corruption"
a7f7f624 1665 help
8f9ca475
IM
1666 Periodically check for memory corruption in low memory, which
1667 is suspected to be caused by BIOS. Even when enabled in the
1668 configuration, it is disabled at runtime. Enable it by
1669 setting "memory_corruption_check=1" on the kernel command
1670 line. By default it scans the low 64k of memory every 60
1671 seconds; see the memory_corruption_check_size and
1672 memory_corruption_check_period parameters in
8c27ceff 1673 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1674
1675 When enabled with the default parameters, this option has
1676 almost no overhead, as it reserves a relatively small amount
1677 of memory and scans it infrequently. It both detects corruption
1678 and prevents it from affecting the running system.
1679
1680 It is, however, intended as a diagnostic tool; if repeatable
1681 BIOS-originated corruption always affects the same memory,
1682 you can use memmap= to prevent the kernel from using that
1683 memory.
9f077871 1684
c885df50 1685config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1686 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1687 depends on X86_CHECK_BIOS_CORRUPTION
1688 default y
a7f7f624 1689 help
8f9ca475
IM
1690 Set whether the default state of memory_corruption_check is
1691 on or off.
c885df50 1692
9ea77bdb 1693config X86_RESERVE_LOW
d0cd7425
PA
1694 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1695 default 64
1696 range 4 640
a7f7f624 1697 help
d0cd7425
PA
1698 Specify the amount of low memory to reserve for the BIOS.
1699
1700 The first page contains BIOS data structures that the kernel
1701 must not use, so that page must always be reserved.
1702
1703 By default we reserve the first 64K of physical RAM, as a
1704 number of BIOSes are known to corrupt that memory range
1705 during events such as suspend/resume or monitor cable
1706 insertion, so it must not be used by the kernel.
fc381519 1707
d0cd7425
PA
1708 You can set this to 4 if you are absolutely sure that you
1709 trust the BIOS to get all its memory reservations and usages
1710 right. If you know your BIOS have problems beyond the
1711 default 64K area, you can set this to 640 to avoid using the
1712 entire low memory range.
fc381519 1713
d0cd7425
PA
1714 If you have doubts about the BIOS (e.g. suspend/resume does
1715 not work or there's kernel crashes after certain hardware
1716 hotplug events) then you might want to enable
1717 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1718 typical corruption patterns.
fc381519 1719
d0cd7425 1720 Leave this to the default value of 64 if you are unsure.
fc381519 1721
506f1d07
SR
1722config MATH_EMULATION
1723 bool
a5b9e5a2 1724 depends on MODIFY_LDT_SYSCALL
87d6021b 1725 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
a7f7f624 1726 help
506f1d07
SR
1727 Linux can emulate a math coprocessor (used for floating point
1728 operations) if you don't have one. 486DX and Pentium processors have
1729 a math coprocessor built in, 486SX and 386 do not, unless you added
1730 a 487DX or 387, respectively. (The messages during boot time can
1731 give you some hints here ["man dmesg"].) Everyone needs either a
1732 coprocessor or this emulation.
1733
1734 If you don't have a math coprocessor, you need to say Y here; if you
1735 say Y here even though you have a coprocessor, the coprocessor will
1736 be used nevertheless. (This behavior can be changed with the kernel
1737 command line option "no387", which comes handy if your coprocessor
1738 is broken. Try "man bootparam" or see the documentation of your boot
1739 loader (lilo or loadlin) about how to pass options to the kernel at
1740 boot time.) This means that it is a good idea to say Y here if you
1741 intend to use this kernel on different machines.
1742
1743 More information about the internals of the Linux math coprocessor
1744 emulation can be found in <file:arch/x86/math-emu/README>.
1745
1746 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1747 kernel, it won't hurt.
1748
1749config MTRR
6fc108a0 1750 def_bool y
6a108a14 1751 prompt "MTRR (Memory Type Range Register) support" if EXPERT
a7f7f624 1752 help
506f1d07
SR
1753 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1754 the Memory Type Range Registers (MTRRs) may be used to control
1755 processor access to memory ranges. This is most useful if you have
1756 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1757 allows bus write transfers to be combined into a larger transfer
1758 before bursting over the PCI/AGP bus. This can increase performance
1759 of image write operations 2.5 times or more. Saying Y here creates a
1760 /proc/mtrr file which may be used to manipulate your processor's
1761 MTRRs. Typically the X server should use this.
1762
1763 This code has a reasonably generic interface so that similar
1764 control registers on other processors can be easily supported
1765 as well:
1766
1767 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1768 Registers (ARRs) which provide a similar functionality to MTRRs. For
1769 these, the ARRs are used to emulate the MTRRs.
1770 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1771 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1772 write-combining. All of these processors are supported by this code
1773 and it makes sense to say Y here if you have one of them.
1774
1775 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1776 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1777 can lead to all sorts of problems, so it's good to say Y here.
1778
1779 You can safely say Y even if your machine doesn't have MTRRs, you'll
1780 just add about 9 KB to your kernel.
1781
cb1aaebe 1782 See <file:Documentation/x86/mtrr.rst> for more information.
506f1d07 1783
95ffa243 1784config MTRR_SANITIZER
2ffb3501 1785 def_bool y
95ffa243
YL
1786 prompt "MTRR cleanup support"
1787 depends on MTRR
a7f7f624 1788 help
aba3728c
TG
1789 Convert MTRR layout from continuous to discrete, so X drivers can
1790 add writeback entries.
95ffa243 1791
aba3728c 1792 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1793 The largest mtrr entry size for a continuous block can be set with
aba3728c 1794 mtrr_chunk_size.
95ffa243 1795
2ffb3501 1796 If unsure, say Y.
95ffa243
YL
1797
1798config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1799 int "MTRR cleanup enable value (0-1)"
1800 range 0 1
1801 default "0"
95ffa243 1802 depends on MTRR_SANITIZER
a7f7f624 1803 help
f5098d62 1804 Enable mtrr cleanup default value
95ffa243 1805
12031a62
YL
1806config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1807 int "MTRR cleanup spare reg num (0-7)"
1808 range 0 7
1809 default "1"
1810 depends on MTRR_SANITIZER
a7f7f624 1811 help
12031a62 1812 mtrr cleanup spare entries default, it can be changed via
aba3728c 1813 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1814
2e5d9c85 1815config X86_PAT
6fc108a0 1816 def_bool y
6a108a14 1817 prompt "x86 PAT support" if EXPERT
2a8a2719 1818 depends on MTRR
a7f7f624 1819 help
2e5d9c85 1820 Use PAT attributes to setup page level cache control.
042b78e4 1821
2e5d9c85 1822 PATs are the modern equivalents of MTRRs and are much more
1823 flexible than MTRRs.
1824
1825 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1826 spontaneous reboots) or a non-working video driver.
2e5d9c85 1827
1828 If unsure, say Y.
1829
46cf98cd
VP
1830config ARCH_USES_PG_UNCACHED
1831 def_bool y
1832 depends on X86_PAT
1833
628c6246
PA
1834config ARCH_RANDOM
1835 def_bool y
1836 prompt "x86 architectural random number generator" if EXPERT
a7f7f624 1837 help
628c6246
PA
1838 Enable the x86 architectural RDRAND instruction
1839 (Intel Bull Mountain technology) to generate random numbers.
1840 If supported, this is a high bandwidth, cryptographically
1841 secure hardware random number generator.
1842
51ae4a2d
PA
1843config X86_SMAP
1844 def_bool y
1845 prompt "Supervisor Mode Access Prevention" if EXPERT
a7f7f624 1846 help
51ae4a2d
PA
1847 Supervisor Mode Access Prevention (SMAP) is a security
1848 feature in newer Intel processors. There is a small
1849 performance cost if this enabled and turned on; there is
1850 also a small increase in the kernel size if this is enabled.
1851
1852 If unsure, say Y.
1853
b971880f 1854config X86_UMIP
796ebc81 1855 def_bool y
b971880f 1856 prompt "User Mode Instruction Prevention" if EXPERT
a7f7f624 1857 help
b971880f
BM
1858 User Mode Instruction Prevention (UMIP) is a security feature in
1859 some x86 processors. If enabled, a general protection fault is
1860 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1861 executed in user mode. These instructions unnecessarily expose
1862 information about the hardware state.
796ebc81
RN
1863
1864 The vast majority of applications do not use these instructions.
1865 For the very few that do, software emulation is provided in
1866 specific cases in protected and virtual-8086 modes. Emulated
1867 results are dummy.
aa35f896 1868
35e97790 1869config X86_INTEL_MEMORY_PROTECTION_KEYS
38f3e775 1870 prompt "Memory Protection Keys"
35e97790 1871 def_bool y
284244a9 1872 # Note: only available in 64-bit mode
38f3e775 1873 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
52c8e601
IM
1874 select ARCH_USES_HIGH_VMA_FLAGS
1875 select ARCH_HAS_PKEYS
a7f7f624 1876 help
284244a9
DH
1877 Memory Protection Keys provides a mechanism for enforcing
1878 page-based protections, but without requiring modification of the
1879 page tables when an application changes protection domains.
1880
1eecbcdc 1881 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1882
1883 If unsure, say y.
35e97790 1884
db616173
MH
1885choice
1886 prompt "TSX enable mode"
1887 depends on CPU_SUP_INTEL
1888 default X86_INTEL_TSX_MODE_OFF
1889 help
1890 Intel's TSX (Transactional Synchronization Extensions) feature
1891 allows to optimize locking protocols through lock elision which
1892 can lead to a noticeable performance boost.
1893
1894 On the other hand it has been shown that TSX can be exploited
1895 to form side channel attacks (e.g. TAA) and chances are there
1896 will be more of those attacks discovered in the future.
1897
1898 Therefore TSX is not enabled by default (aka tsx=off). An admin
1899 might override this decision by tsx=on the command line parameter.
1900 Even with TSX enabled, the kernel will attempt to enable the best
1901 possible TAA mitigation setting depending on the microcode available
1902 for the particular machine.
1903
1904 This option allows to set the default tsx mode between tsx=on, =off
1905 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1906 details.
1907
1908 Say off if not sure, auto if TSX is in use but it should be used on safe
1909 platforms or on if TSX is in use and the security aspect of tsx is not
1910 relevant.
1911
1912config X86_INTEL_TSX_MODE_OFF
1913 bool "off"
1914 help
1915 TSX is disabled if possible - equals to tsx=off command line parameter.
1916
1917config X86_INTEL_TSX_MODE_ON
1918 bool "on"
1919 help
1920 TSX is always enabled on TSX capable HW - equals the tsx=on command
1921 line parameter.
1922
1923config X86_INTEL_TSX_MODE_AUTO
1924 bool "auto"
1925 help
1926 TSX is enabled on TSX capable HW that is believed to be safe against
1927 side channel attacks- equals the tsx=auto command line parameter.
1928endchoice
1929
506f1d07 1930config EFI
9ba16087 1931 bool "EFI runtime service support"
5b83683f 1932 depends on ACPI
f6ce5002 1933 select UCS2_STRING
022ee6c5 1934 select EFI_RUNTIME_WRAPPERS
a7f7f624 1935 help
8f9ca475
IM
1936 This enables the kernel to use EFI runtime services that are
1937 available (such as the EFI variable services).
506f1d07 1938
8f9ca475
IM
1939 This option is only useful on systems that have EFI firmware.
1940 In addition, you should use the latest ELILO loader available
1941 at <http://elilo.sourceforge.net> in order to take advantage
1942 of EFI runtime services. However, even with this option, the
1943 resultant kernel should continue to boot on existing non-EFI
1944 platforms.
506f1d07 1945
291f3632 1946config EFI_STUB
8f24f8c2
AB
1947 bool "EFI stub support"
1948 depends on EFI && !X86_USE_3DNOW
1949 depends on $(cc-option,-mabi=ms) || X86_32
1950 select RELOCATABLE
a7f7f624 1951 help
8f24f8c2 1952 This kernel feature allows a bzImage to be loaded directly
291f3632
MF
1953 by EFI firmware without the use of a bootloader.
1954
4f4cfa6c 1955 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 1956
7d453eee
MF
1957config EFI_MIXED
1958 bool "EFI mixed-mode support"
1959 depends on EFI_STUB && X86_64
a7f7f624 1960 help
7d453eee
MF
1961 Enabling this feature allows a 64-bit kernel to be booted
1962 on a 32-bit firmware, provided that your CPU supports 64-bit
1963 mode.
1964
1965 Note that it is not possible to boot a mixed-mode enabled
1966 kernel via the EFI boot stub - a bootloader that supports
1967 the EFI handover protocol must be used.
1968
1969 If unsure, say N.
1970
506f1d07 1971config SECCOMP
3c2362e6
HH
1972 def_bool y
1973 prompt "Enable seccomp to safely compute untrusted bytecode"
a7f7f624 1974 help
506f1d07
SR
1975 This kernel feature is useful for number crunching applications
1976 that may need to compute untrusted bytecode during their
1977 execution. By using pipes or other transports made available to
1978 the process as file descriptors supporting the read/write
1979 syscalls, it's possible to isolate those applications in
1980 their own address space using seccomp. Once seccomp is
9c0bbee8 1981 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1982 and the task is only allowed to execute a few safe syscalls
1983 defined by each seccomp mode.
1984
1985 If unsure, say Y. Only embedded should say N here.
1986
8636a1f9 1987source "kernel/Kconfig.hz"
506f1d07
SR
1988
1989config KEXEC
1990 bool "kexec system call"
2965faa5 1991 select KEXEC_CORE
a7f7f624 1992 help
506f1d07
SR
1993 kexec is a system call that implements the ability to shutdown your
1994 current kernel, and to start another kernel. It is like a reboot
1995 but it is independent of the system firmware. And like a reboot
1996 you can start any kernel with it, not just Linux.
1997
1998 The name comes from the similarity to the exec system call.
1999
2000 It is an ongoing process to be certain the hardware in a machine
2001 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
2002 initially work for you. As of this writing the exact hardware
2003 interface is strongly in flux, so no good recommendation can be
2004 made.
506f1d07 2005
74ca317c
VG
2006config KEXEC_FILE
2007 bool "kexec file based system call"
2965faa5 2008 select KEXEC_CORE
74ca317c 2009 select BUILD_BIN2C
74ca317c
VG
2010 depends on X86_64
2011 depends on CRYPTO=y
2012 depends on CRYPTO_SHA256=y
a7f7f624 2013 help
74ca317c
VG
2014 This is new version of kexec system call. This system call is
2015 file based and takes file descriptors as system call argument
2016 for kernel and initramfs as opposed to list of segments as
2017 accepted by previous system call.
2018
b799a09f
AT
2019config ARCH_HAS_KEXEC_PURGATORY
2020 def_bool KEXEC_FILE
2021
99d5cadf 2022config KEXEC_SIG
8e7d8381 2023 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2024 depends on KEXEC_FILE
a7f7f624 2025 help
d8eb8940 2026
99d5cadf
JB
2027 This option makes the kexec_file_load() syscall check for a valid
2028 signature of the kernel image. The image can still be loaded without
2029 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2030 there's a signature that we can check, then it must be valid.
2031
2032 In addition to this option, you need to enable signature
d8eb8940
BP
2033 verification for the corresponding kernel image type being
2034 loaded in order for this to work.
8e7d8381 2035
99d5cadf
JB
2036config KEXEC_SIG_FORCE
2037 bool "Require a valid signature in kexec_file_load() syscall"
2038 depends on KEXEC_SIG
a7f7f624 2039 help
99d5cadf
JB
2040 This option makes kernel signature verification mandatory for
2041 the kexec_file_load() syscall.
2042
8e7d8381
VG
2043config KEXEC_BZIMAGE_VERIFY_SIG
2044 bool "Enable bzImage signature verification support"
99d5cadf 2045 depends on KEXEC_SIG
8e7d8381
VG
2046 depends on SIGNED_PE_FILE_VERIFICATION
2047 select SYSTEM_TRUSTED_KEYRING
a7f7f624 2048 help
8e7d8381
VG
2049 Enable bzImage signature verification support.
2050
506f1d07 2051config CRASH_DUMP
04b69447 2052 bool "kernel crash dumps"
506f1d07 2053 depends on X86_64 || (X86_32 && HIGHMEM)
a7f7f624 2054 help
506f1d07
SR
2055 Generate crash dump after being started by kexec.
2056 This should be normally only set in special crash dump kernels
2057 which are loaded in the main kernel with kexec-tools into
2058 a specially reserved region and then later executed after
2059 a crash by kdump/kexec. The crash dump kernel must be compiled
2060 to a memory address not used by the main kernel or BIOS using
2061 PHYSICAL_START, or it must be built as a relocatable image
2062 (CONFIG_RELOCATABLE=y).
330d4810 2063 For more details see Documentation/admin-guide/kdump/kdump.rst
506f1d07 2064
3ab83521 2065config KEXEC_JUMP
6ea30386 2066 bool "kexec jump"
fee7b0d8 2067 depends on KEXEC && HIBERNATION
a7f7f624 2068 help
89081d17
HY
2069 Jump between original kernel and kexeced kernel and invoke
2070 code in physical address mode via KEXEC
3ab83521 2071
506f1d07 2072config PHYSICAL_START
6a108a14 2073 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2074 default "0x1000000"
a7f7f624 2075 help
506f1d07
SR
2076 This gives the physical address where the kernel is loaded.
2077
2078 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2079 bzImage will decompress itself to above physical address and
2080 run from there. Otherwise, bzImage will run from the address where
2081 it has been loaded by the boot loader and will ignore above physical
2082 address.
2083
2084 In normal kdump cases one does not have to set/change this option
2085 as now bzImage can be compiled as a completely relocatable image
2086 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2087 address. This option is mainly useful for the folks who don't want
2088 to use a bzImage for capturing the crash dump and want to use a
2089 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2090 to be specifically compiled to run from a specific memory area
2091 (normally a reserved region) and this option comes handy.
2092
ceefccc9
PA
2093 So if you are using bzImage for capturing the crash dump,
2094 leave the value here unchanged to 0x1000000 and set
2095 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2096 for capturing the crash dump change this value to start of
2097 the reserved region. In other words, it can be set based on
2098 the "X" value as specified in the "crashkernel=YM@XM"
2099 command line boot parameter passed to the panic-ed
330d4810 2100 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
ceefccc9 2101 for more details about crash dumps.
506f1d07
SR
2102
2103 Usage of bzImage for capturing the crash dump is recommended as
2104 one does not have to build two kernels. Same kernel can be used
2105 as production kernel and capture kernel. Above option should have
2106 gone away after relocatable bzImage support is introduced. But it
2107 is present because there are users out there who continue to use
2108 vmlinux for dump capture. This option should go away down the
2109 line.
2110
2111 Don't change this unless you know what you are doing.
2112
2113config RELOCATABLE
26717808
PA
2114 bool "Build a relocatable kernel"
2115 default y
a7f7f624 2116 help
506f1d07
SR
2117 This builds a kernel image that retains relocation information
2118 so it can be loaded someplace besides the default 1MB.
2119 The relocations tend to make the kernel binary about 10% larger,
2120 but are discarded at runtime.
2121
2122 One use is for the kexec on panic case where the recovery kernel
2123 must live at a different physical address than the primary
2124 kernel.
2125
2126 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2127 it has been loaded at and the compile time physical address
8ab3820f 2128 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2129
8ab3820f 2130config RANDOMIZE_BASE
e8581e3d 2131 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2132 depends on RELOCATABLE
6807c846 2133 default y
a7f7f624 2134 help
e8581e3d
BH
2135 In support of Kernel Address Space Layout Randomization (KASLR),
2136 this randomizes the physical address at which the kernel image
2137 is decompressed and the virtual address where the kernel
2138 image is mapped, as a security feature that deters exploit
2139 attempts relying on knowledge of the location of kernel
2140 code internals.
2141
ed9f007e
KC
2142 On 64-bit, the kernel physical and virtual addresses are
2143 randomized separately. The physical address will be anywhere
2144 between 16MB and the top of physical memory (up to 64TB). The
2145 virtual address will be randomized from 16MB up to 1GB (9 bits
2146 of entropy). Note that this also reduces the memory space
2147 available to kernel modules from 1.5GB to 1GB.
2148
2149 On 32-bit, the kernel physical and virtual addresses are
2150 randomized together. They will be randomized from 16MB up to
2151 512MB (8 bits of entropy).
e8581e3d
BH
2152
2153 Entropy is generated using the RDRAND instruction if it is
2154 supported. If RDTSC is supported, its value is mixed into
2155 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2156 supported, then entropy is read from the i8254 timer. The
2157 usable entropy is limited by the kernel being built using
2158 2GB addressing, and that PHYSICAL_ALIGN must be at a
2159 minimum of 2MB. As a result, only 10 bits of entropy are
2160 theoretically possible, but the implementations are further
2161 limited due to memory layouts.
e8581e3d 2162
6807c846 2163 If unsure, say Y.
8ab3820f
KC
2164
2165# Relocation on x86 needs some additional build support
845adf72
PA
2166config X86_NEED_RELOCS
2167 def_bool y
8ab3820f 2168 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2169
506f1d07 2170config PHYSICAL_ALIGN
a0215061 2171 hex "Alignment value to which kernel should be aligned"
8ab3820f 2172 default "0x200000"
a0215061
KC
2173 range 0x2000 0x1000000 if X86_32
2174 range 0x200000 0x1000000 if X86_64
a7f7f624 2175 help
506f1d07
SR
2176 This value puts the alignment restrictions on physical address
2177 where kernel is loaded and run from. Kernel is compiled for an
2178 address which meets above alignment restriction.
2179
2180 If bootloader loads the kernel at a non-aligned address and
2181 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2182 address aligned to above value and run from there.
2183
2184 If bootloader loads the kernel at a non-aligned address and
2185 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2186 load address and decompress itself to the address it has been
2187 compiled for and run from there. The address for which kernel is
2188 compiled already meets above alignment restrictions. Hence the
2189 end result is that kernel runs from a physical address meeting
2190 above alignment restrictions.
2191
a0215061
KC
2192 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2193 this value must be a multiple of 0x200000.
2194
506f1d07
SR
2195 Don't change this unless you know what you are doing.
2196
eedb92ab
KS
2197config DYNAMIC_MEMORY_LAYOUT
2198 bool
a7f7f624 2199 help
eedb92ab
KS
2200 This option makes base addresses of vmalloc and vmemmap as well as
2201 __PAGE_OFFSET movable during boot.
2202
0483e1fa
TG
2203config RANDOMIZE_MEMORY
2204 bool "Randomize the kernel memory sections"
2205 depends on X86_64
2206 depends on RANDOMIZE_BASE
eedb92ab 2207 select DYNAMIC_MEMORY_LAYOUT
0483e1fa 2208 default RANDOMIZE_BASE
a7f7f624 2209 help
0483e1fa
TG
2210 Randomizes the base virtual address of kernel memory sections
2211 (physical memory mapping, vmalloc & vmemmap). This security feature
2212 makes exploits relying on predictable memory locations less reliable.
2213
2214 The order of allocations remains unchanged. Entropy is generated in
2215 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2216 configuration have in average 30,000 different possible virtual
2217 addresses for each memory section.
2218
6807c846 2219 If unsure, say Y.
0483e1fa 2220
90397a41
TG
2221config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2222 hex "Physical memory mapping padding" if EXPERT
2223 depends on RANDOMIZE_MEMORY
2224 default "0xa" if MEMORY_HOTPLUG
2225 default "0x0"
2226 range 0x1 0x40 if MEMORY_HOTPLUG
2227 range 0x0 0x40
a7f7f624 2228 help
90397a41
TG
2229 Define the padding in terabytes added to the existing physical
2230 memory size during kernel memory randomization. It is useful
2231 for memory hotplug support but reduces the entropy available for
2232 address randomization.
2233
2234 If unsure, leave at the default value.
2235
506f1d07 2236config HOTPLUG_CPU
bebd024e 2237 def_bool y
40b31360 2238 depends on SMP
506f1d07 2239
80aa1dff
FY
2240config BOOTPARAM_HOTPLUG_CPU0
2241 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2242 depends on HOTPLUG_CPU
a7f7f624 2243 help
80aa1dff
FY
2244 Set whether default state of cpu0_hotpluggable is on or off.
2245
2246 Say Y here to enable CPU0 hotplug by default. If this switch
2247 is turned on, there is no need to give cpu0_hotplug kernel
2248 parameter and the CPU0 hotplug feature is enabled by default.
2249
2250 Please note: there are two known CPU0 dependencies if you want
2251 to enable the CPU0 hotplug feature either by this switch or by
2252 cpu0_hotplug kernel parameter.
2253
2254 First, resume from hibernate or suspend always starts from CPU0.
2255 So hibernate and suspend are prevented if CPU0 is offline.
2256
2257 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2258 offline if any interrupt can not migrate out of CPU0. There may
2259 be other CPU0 dependencies.
2260
2261 Please make sure the dependencies are under your control before
2262 you enable this feature.
2263
2264 Say N if you don't want to enable CPU0 hotplug feature by default.
2265 You still can enable the CPU0 hotplug feature at boot by kernel
2266 parameter cpu0_hotplug.
2267
a71c8bc5
FY
2268config DEBUG_HOTPLUG_CPU0
2269 def_bool n
2270 prompt "Debug CPU0 hotplug"
2c922cd0 2271 depends on HOTPLUG_CPU
a7f7f624 2272 help
a71c8bc5
FY
2273 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2274 soon as possible and boots up userspace with CPU0 offlined. User
2275 can online CPU0 back after boot time.
2276
2277 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2278 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2279 compilation or giving cpu0_hotplug kernel parameter at boot.
2280
2281 If unsure, say N.
2282
506f1d07 2283config COMPAT_VDSO
b0b49f26
AL
2284 def_bool n
2285 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2286 depends on COMPAT_32
a7f7f624 2287 help
b0b49f26
AL
2288 Certain buggy versions of glibc will crash if they are
2289 presented with a 32-bit vDSO that is not mapped at the address
2290 indicated in its segment table.
e84446de 2291
b0b49f26
AL
2292 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2293 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2294 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2295 the only released version with the bug, but OpenSUSE 9
2296 contains a buggy "glibc 2.3.2".
506f1d07 2297
b0b49f26
AL
2298 The symptom of the bug is that everything crashes on startup, saying:
2299 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2300
2301 Saying Y here changes the default value of the vdso32 boot
2302 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2303 This works around the glibc bug but hurts performance.
2304
2305 If unsure, say N: if you are compiling your own kernel, you
2306 are unlikely to be using a buggy version of glibc.
506f1d07 2307
3dc33bd3
KC
2308choice
2309 prompt "vsyscall table for legacy applications"
2310 depends on X86_64
625b7b7f 2311 default LEGACY_VSYSCALL_XONLY
3dc33bd3
KC
2312 help
2313 Legacy user code that does not know how to find the vDSO expects
2314 to be able to issue three syscalls by calling fixed addresses in
2315 kernel space. Since this location is not randomized with ASLR,
2316 it can be used to assist security vulnerability exploitation.
2317
2318 This setting can be changed at boot time via the kernel command
bd49e16e 2319 line parameter vsyscall=[emulate|xonly|none].
3dc33bd3
KC
2320
2321 On a system with recent enough glibc (2.14 or newer) and no
2322 static binaries, you can say None without a performance penalty
2323 to improve security.
2324
bd49e16e 2325 If unsure, select "Emulate execution only".
3dc33bd3 2326
3dc33bd3 2327 config LEGACY_VSYSCALL_EMULATE
bd49e16e 2328 bool "Full emulation"
3dc33bd3 2329 help
bd49e16e
AL
2330 The kernel traps and emulates calls into the fixed vsyscall
2331 address mapping. This makes the mapping non-executable, but
2332 it still contains readable known contents, which could be
2333 used in certain rare security vulnerability exploits. This
2334 configuration is recommended when using legacy userspace
2335 that still uses vsyscalls along with legacy binary
2336 instrumentation tools that require code to be readable.
2337
2338 An example of this type of legacy userspace is running
2339 Pin on an old binary that still uses vsyscalls.
2340
2341 config LEGACY_VSYSCALL_XONLY
2342 bool "Emulate execution only"
2343 help
2344 The kernel traps and emulates calls into the fixed vsyscall
2345 address mapping and does not allow reads. This
2346 configuration is recommended when userspace might use the
2347 legacy vsyscall area but support for legacy binary
2348 instrumentation of legacy code is not needed. It mitigates
2349 certain uses of the vsyscall area as an ASLR-bypassing
2350 buffer.
3dc33bd3
KC
2351
2352 config LEGACY_VSYSCALL_NONE
2353 bool "None"
2354 help
2355 There will be no vsyscall mapping at all. This will
2356 eliminate any risk of ASLR bypass due to the vsyscall
2357 fixed address mapping. Attempts to use the vsyscalls
2358 will be reported to dmesg, so that either old or
2359 malicious userspace programs can be identified.
2360
2361endchoice
2362
516cbf37
TB
2363config CMDLINE_BOOL
2364 bool "Built-in kernel command line"
a7f7f624 2365 help
516cbf37
TB
2366 Allow for specifying boot arguments to the kernel at
2367 build time. On some systems (e.g. embedded ones), it is
2368 necessary or convenient to provide some or all of the
2369 kernel boot arguments with the kernel itself (that is,
2370 to not rely on the boot loader to provide them.)
2371
2372 To compile command line arguments into the kernel,
2373 set this option to 'Y', then fill in the
69711ca1 2374 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2375
2376 Systems with fully functional boot loaders (i.e. non-embedded)
2377 should leave this option set to 'N'.
2378
2379config CMDLINE
2380 string "Built-in kernel command string"
2381 depends on CMDLINE_BOOL
2382 default ""
a7f7f624 2383 help
516cbf37
TB
2384 Enter arguments here that should be compiled into the kernel
2385 image and used at boot time. If the boot loader provides a
2386 command line at boot time, it is appended to this string to
2387 form the full kernel command line, when the system boots.
2388
2389 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2390 change this behavior.
2391
2392 In most cases, the command line (whether built-in or provided
2393 by the boot loader) should specify the device for the root
2394 file system.
2395
2396config CMDLINE_OVERRIDE
2397 bool "Built-in command line overrides boot loader arguments"
645e6466 2398 depends on CMDLINE_BOOL && CMDLINE != ""
a7f7f624 2399 help
516cbf37
TB
2400 Set this option to 'Y' to have the kernel ignore the boot loader
2401 command line, and use ONLY the built-in command line.
2402
2403 This is used to work around broken boot loaders. This should
2404 be set to 'N' under normal conditions.
2405
a5b9e5a2
AL
2406config MODIFY_LDT_SYSCALL
2407 bool "Enable the LDT (local descriptor table)" if EXPERT
2408 default y
a7f7f624 2409 help
a5b9e5a2
AL
2410 Linux can allow user programs to install a per-process x86
2411 Local Descriptor Table (LDT) using the modify_ldt(2) system
2412 call. This is required to run 16-bit or segmented code such as
2413 DOSEMU or some Wine programs. It is also used by some very old
2414 threading libraries.
2415
2416 Enabling this feature adds a small amount of overhead to
2417 context switches and increases the low-level kernel attack
2418 surface. Disabling it removes the modify_ldt(2) system call.
2419
2420 Saying 'N' here may make sense for embedded or server kernels.
2421
b700e7f0
SJ
2422source "kernel/livepatch/Kconfig"
2423
506f1d07
SR
2424endmenu
2425
3072e413
MH
2426config ARCH_HAS_ADD_PAGES
2427 def_bool y
2428 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2429
506f1d07
SR
2430config ARCH_ENABLE_MEMORY_HOTPLUG
2431 def_bool y
2432 depends on X86_64 || (X86_32 && HIGHMEM)
2433
35551053
GH
2434config ARCH_ENABLE_MEMORY_HOTREMOVE
2435 def_bool y
2436 depends on MEMORY_HOTPLUG
2437
e534c7c5 2438config USE_PERCPU_NUMA_NODE_ID
645a7919 2439 def_bool y
e534c7c5
LS
2440 depends on NUMA
2441
9491846f
KS
2442config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2443 def_bool y
2444 depends on X86_64 || X86_PAE
2445
c177c81e
NH
2446config ARCH_ENABLE_HUGEPAGE_MIGRATION
2447 def_bool y
2448 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2449
9c670ea3
NH
2450config ARCH_ENABLE_THP_MIGRATION
2451 def_bool y
2452 depends on X86_64 && TRANSPARENT_HUGEPAGE
2453
da85f865 2454menu "Power management and ACPI options"
e279b6c1
SR
2455
2456config ARCH_HIBERNATION_HEADER
3c2362e6 2457 def_bool y
44556530 2458 depends on HIBERNATION
e279b6c1
SR
2459
2460source "kernel/power/Kconfig"
2461
2462source "drivers/acpi/Kconfig"
2463
efafc8b2
FT
2464source "drivers/sfi/Kconfig"
2465
a6b68076 2466config X86_APM_BOOT
6fc108a0 2467 def_bool y
282e5aab 2468 depends on APM
a6b68076 2469
e279b6c1
SR
2470menuconfig APM
2471 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2472 depends on X86_32 && PM_SLEEP
a7f7f624 2473 help
e279b6c1
SR
2474 APM is a BIOS specification for saving power using several different
2475 techniques. This is mostly useful for battery powered laptops with
2476 APM compliant BIOSes. If you say Y here, the system time will be
2477 reset after a RESUME operation, the /proc/apm device will provide
2478 battery status information, and user-space programs will receive
2479 notification of APM "events" (e.g. battery status change).
2480
2481 If you select "Y" here, you can disable actual use of the APM
2482 BIOS by passing the "apm=off" option to the kernel at boot time.
2483
2484 Note that the APM support is almost completely disabled for
2485 machines with more than one CPU.
2486
2487 In order to use APM, you will need supporting software. For location
151f4e2b 2488 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2489 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2490 <http://www.tldp.org/docs.html#howto>.
2491
2492 This driver does not spin down disk drives (see the hdparm(8)
2493 manpage ("man 8 hdparm") for that), and it doesn't turn off
2494 VESA-compliant "green" monitors.
2495
2496 This driver does not support the TI 4000M TravelMate and the ACER
2497 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2498 desktop machines also don't have compliant BIOSes, and this driver
2499 may cause those machines to panic during the boot phase.
2500
2501 Generally, if you don't have a battery in your machine, there isn't
2502 much point in using this driver and you should say N. If you get
2503 random kernel OOPSes or reboots that don't seem to be related to
2504 anything, try disabling/enabling this option (or disabling/enabling
2505 APM in your BIOS).
2506
2507 Some other things you should try when experiencing seemingly random,
2508 "weird" problems:
2509
2510 1) make sure that you have enough swap space and that it is
2511 enabled.
2512 2) pass the "no-hlt" option to the kernel
2513 3) switch on floating point emulation in the kernel and pass
2514 the "no387" option to the kernel
2515 4) pass the "floppy=nodma" option to the kernel
2516 5) pass the "mem=4M" option to the kernel (thereby disabling
2517 all but the first 4 MB of RAM)
2518 6) make sure that the CPU is not over clocked.
2519 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2520 8) disable the cache from your BIOS settings
2521 9) install a fan for the video card or exchange video RAM
2522 10) install a better fan for the CPU
2523 11) exchange RAM chips
2524 12) exchange the motherboard.
2525
2526 To compile this driver as a module, choose M here: the
2527 module will be called apm.
2528
2529if APM
2530
2531config APM_IGNORE_USER_SUSPEND
2532 bool "Ignore USER SUSPEND"
a7f7f624 2533 help
e279b6c1
SR
2534 This option will ignore USER SUSPEND requests. On machines with a
2535 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2536 series notebooks, it is necessary to say Y because of a BIOS bug.
2537
2538config APM_DO_ENABLE
2539 bool "Enable PM at boot time"
a7f7f624 2540 help
e279b6c1
SR
2541 Enable APM features at boot time. From page 36 of the APM BIOS
2542 specification: "When disabled, the APM BIOS does not automatically
2543 power manage devices, enter the Standby State, enter the Suspend
2544 State, or take power saving steps in response to CPU Idle calls."
2545 This driver will make CPU Idle calls when Linux is idle (unless this
2546 feature is turned off -- see "Do CPU IDLE calls", below). This
2547 should always save battery power, but more complicated APM features
2548 will be dependent on your BIOS implementation. You may need to turn
2549 this option off if your computer hangs at boot time when using APM
2550 support, or if it beeps continuously instead of suspending. Turn
2551 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2552 T400CDT. This is off by default since most machines do fine without
2553 this feature.
2554
2555config APM_CPU_IDLE
dd8af076 2556 depends on CPU_IDLE
e279b6c1 2557 bool "Make CPU Idle calls when idle"
a7f7f624 2558 help
e279b6c1
SR
2559 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2560 On some machines, this can activate improved power savings, such as
2561 a slowed CPU clock rate, when the machine is idle. These idle calls
2562 are made after the idle loop has run for some length of time (e.g.,
2563 333 mS). On some machines, this will cause a hang at boot time or
2564 whenever the CPU becomes idle. (On machines with more than one CPU,
2565 this option does nothing.)
2566
2567config APM_DISPLAY_BLANK
2568 bool "Enable console blanking using APM"
a7f7f624 2569 help
e279b6c1
SR
2570 Enable console blanking using the APM. Some laptops can use this to
2571 turn off the LCD backlight when the screen blanker of the Linux
2572 virtual console blanks the screen. Note that this is only used by
2573 the virtual console screen blanker, and won't turn off the backlight
2574 when using the X Window system. This also doesn't have anything to
2575 do with your VESA-compliant power-saving monitor. Further, this
2576 option doesn't work for all laptops -- it might not turn off your
2577 backlight at all, or it might print a lot of errors to the console,
2578 especially if you are using gpm.
2579
2580config APM_ALLOW_INTS
2581 bool "Allow interrupts during APM BIOS calls"
a7f7f624 2582 help
e279b6c1
SR
2583 Normally we disable external interrupts while we are making calls to
2584 the APM BIOS as a measure to lessen the effects of a badly behaving
2585 BIOS implementation. The BIOS should reenable interrupts if it
2586 needs to. Unfortunately, some BIOSes do not -- especially those in
2587 many of the newer IBM Thinkpads. If you experience hangs when you
2588 suspend, try setting this to Y. Otherwise, say N.
2589
e279b6c1
SR
2590endif # APM
2591
bb0a56ec 2592source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2593
2594source "drivers/cpuidle/Kconfig"
2595
27471fdb
AH
2596source "drivers/idle/Kconfig"
2597
e279b6c1
SR
2598endmenu
2599
2600
2601menu "Bus options (PCI etc.)"
2602
e279b6c1
SR
2603choice
2604 prompt "PCI access mode"
efefa6f6 2605 depends on X86_32 && PCI
e279b6c1 2606 default PCI_GOANY
a7f7f624 2607 help
e279b6c1
SR
2608 On PCI systems, the BIOS can be used to detect the PCI devices and
2609 determine their configuration. However, some old PCI motherboards
2610 have BIOS bugs and may crash if this is done. Also, some embedded
2611 PCI-based systems don't have any BIOS at all. Linux can also try to
2612 detect the PCI hardware directly without using the BIOS.
2613
2614 With this option, you can specify how Linux should detect the
2615 PCI devices. If you choose "BIOS", the BIOS will be used,
2616 if you choose "Direct", the BIOS won't be used, and if you
2617 choose "MMConfig", then PCI Express MMCONFIG will be used.
2618 If you choose "Any", the kernel will try MMCONFIG, then the
2619 direct access method and falls back to the BIOS if that doesn't
2620 work. If unsure, go with the default, which is "Any".
2621
2622config PCI_GOBIOS
2623 bool "BIOS"
2624
2625config PCI_GOMMCONFIG
2626 bool "MMConfig"
2627
2628config PCI_GODIRECT
2629 bool "Direct"
2630
3ef0e1f8 2631config PCI_GOOLPC
76fb6570 2632 bool "OLPC XO-1"
3ef0e1f8
AS
2633 depends on OLPC
2634
2bdd1b03
AS
2635config PCI_GOANY
2636 bool "Any"
2637
e279b6c1
SR
2638endchoice
2639
2640config PCI_BIOS
3c2362e6 2641 def_bool y
efefa6f6 2642 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2643
2644# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2645config PCI_DIRECT
3c2362e6 2646 def_bool y
0aba496f 2647 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2648
2649config PCI_MMCONFIG
b45c9f36
JK
2650 bool "Support mmconfig PCI config space access" if X86_64
2651 default y
8364e1f8 2652 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2653 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2654
3ef0e1f8 2655config PCI_OLPC
2bdd1b03
AS
2656 def_bool y
2657 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2658
b5401a96
AN
2659config PCI_XEN
2660 def_bool y
2661 depends on PCI && XEN
2662 select SWIOTLB_XEN
2663
8364e1f8
JK
2664config MMCONF_FAM10H
2665 def_bool y
2666 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2667
3f6ea84a 2668config PCI_CNB20LE_QUIRK
6a108a14 2669 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2670 depends on PCI
3f6ea84a
IS
2671 help
2672 Read the PCI windows out of the CNB20LE host bridge. This allows
2673 PCI hotplug to work on systems with the CNB20LE chipset which do
2674 not have ACPI.
2675
64a5fed6
BH
2676 There's no public spec for this chipset, and this functionality
2677 is known to be incomplete.
2678
2679 You should say N unless you know you need this.
2680
3a495511 2681config ISA_BUS
17a2a129 2682 bool "ISA bus support on modern systems" if EXPERT
3a495511 2683 help
17a2a129
WBG
2684 Expose ISA bus device drivers and options available for selection and
2685 configuration. Enable this option if your target machine has an ISA
2686 bus. ISA is an older system, displaced by PCI and newer bus
2687 architectures -- if your target machine is modern, it probably does
2688 not have an ISA bus.
3a495511
WBG
2689
2690 If unsure, say N.
2691
1c00f016 2692# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2693config ISA_DMA_API
1c00f016
DR
2694 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2695 default y
2696 help
2697 Enables ISA-style DMA support for devices requiring such controllers.
2698 If unsure, say Y.
e279b6c1 2699
51e68d05
LT
2700if X86_32
2701
e279b6c1
SR
2702config ISA
2703 bool "ISA support"
a7f7f624 2704 help
e279b6c1
SR
2705 Find out whether you have ISA slots on your motherboard. ISA is the
2706 name of a bus system, i.e. the way the CPU talks to the other stuff
2707 inside your box. Other bus systems are PCI, EISA, MicroChannel
2708 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2709 newer boards don't support it. If you have ISA, say Y, otherwise N.
2710
e279b6c1
SR
2711config SCx200
2712 tristate "NatSemi SCx200 support"
a7f7f624 2713 help
e279b6c1
SR
2714 This provides basic support for National Semiconductor's
2715 (now AMD's) Geode processors. The driver probes for the
2716 PCI-IDs of several on-chip devices, so its a good dependency
2717 for other scx200_* drivers.
2718
2719 If compiled as a module, the driver is named scx200.
2720
2721config SCx200HR_TIMER
2722 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2723 depends on SCx200
e279b6c1 2724 default y
a7f7f624 2725 help
e279b6c1
SR
2726 This driver provides a clocksource built upon the on-chip
2727 27MHz high-resolution timer. Its also a workaround for
2728 NSC Geode SC-1100's buggy TSC, which loses time when the
2729 processor goes idle (as is done by the scheduler). The
2730 other workaround is idle=poll boot option.
2731
3ef0e1f8
AS
2732config OLPC
2733 bool "One Laptop Per Child support"
54008979 2734 depends on !X86_PAE
3c554946 2735 select GPIOLIB
dc3119e7 2736 select OF
45bb1674 2737 select OF_PROMTREE
b4e51854 2738 select IRQ_DOMAIN
0c3d931b 2739 select OLPC_EC
a7f7f624 2740 help
3ef0e1f8
AS
2741 Add support for detecting the unique features of the OLPC
2742 XO hardware.
2743
a3128588
DD
2744config OLPC_XO1_PM
2745 bool "OLPC XO-1 Power Management"
fa112cf1 2746 depends on OLPC && MFD_CS5535=y && PM_SLEEP
a7f7f624 2747 help
97c4cb71 2748 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2749
cfee9597
DD
2750config OLPC_XO1_RTC
2751 bool "OLPC XO-1 Real Time Clock"
2752 depends on OLPC_XO1_PM && RTC_DRV_CMOS
a7f7f624 2753 help
cfee9597
DD
2754 Add support for the XO-1 real time clock, which can be used as a
2755 programmable wakeup source.
2756
7feda8e9
DD
2757config OLPC_XO1_SCI
2758 bool "OLPC XO-1 SCI extras"
92e830f2 2759 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2760 depends on INPUT=y
d8d01a63 2761 select POWER_SUPPLY
a7f7f624 2762 help
7feda8e9 2763 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2764 - EC-driven system wakeups
7feda8e9 2765 - Power button
7bc74b3d 2766 - Ebook switch
2cf2baea 2767 - Lid switch
e1040ac6
DD
2768 - AC adapter status updates
2769 - Battery status updates
7feda8e9 2770
a0f30f59
DD
2771config OLPC_XO15_SCI
2772 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2773 depends on OLPC && ACPI
2774 select POWER_SUPPLY
a7f7f624 2775 help
a0f30f59
DD
2776 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2777 - EC-driven system wakeups
2778 - AC adapter status updates
2779 - Battery status updates
bf1ebf00 2780
d4f3e350
EW
2781config ALIX
2782 bool "PCEngines ALIX System Support (LED setup)"
2783 select GPIOLIB
a7f7f624 2784 help
d4f3e350
EW
2785 This option enables system support for the PCEngines ALIX.
2786 At present this just sets up LEDs for GPIO control on
2787 ALIX2/3/6 boards. However, other system specific setup should
2788 get added here.
2789
2790 Note: You must still enable the drivers for GPIO and LED support
2791 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2792
2793 Note: You have to set alix.force=1 for boards with Award BIOS.
2794
da4e3302
PP
2795config NET5501
2796 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2797 select GPIOLIB
a7f7f624 2798 help
da4e3302
PP
2799 This option enables system support for the Soekris Engineering net5501.
2800
3197059a
PP
2801config GEOS
2802 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2803 select GPIOLIB
2804 depends on DMI
a7f7f624 2805 help
3197059a
PP
2806 This option enables system support for the Traverse Technologies GEOS.
2807
7d029125
VD
2808config TS5500
2809 bool "Technologic Systems TS-5500 platform support"
2810 depends on MELAN
2811 select CHECK_SIGNATURE
2812 select NEW_LEDS
2813 select LEDS_CLASS
a7f7f624 2814 help
7d029125
VD
2815 This option enables system support for the Technologic Systems TS-5500.
2816
bc0120fd
SR
2817endif # X86_32
2818
23ac4ae8 2819config AMD_NB
e279b6c1 2820 def_bool y
0e152cd7 2821 depends on CPU_SUP_AMD && PCI
e279b6c1 2822
e3263ab3
DH
2823config X86_SYSFB
2824 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2825 help
2826 Firmwares often provide initial graphics framebuffers so the BIOS,
2827 bootloader or kernel can show basic video-output during boot for
2828 user-guidance and debugging. Historically, x86 used the VESA BIOS
2829 Extensions and EFI-framebuffers for this, which are mostly limited
2830 to x86.
2831 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2832 framebuffers so the new generic system-framebuffer drivers can be
2833 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2834 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DH
2835 drivers like efifb, vesafb and uvesafb can pick it up.
2836 If this option is not selected, all system framebuffers are always
2837 marked as fallback platform framebuffers as usual.
2838
2839 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2840 not be able to pick up generic system framebuffers if this option
2841 is selected. You are highly encouraged to enable simplefb as
2842 replacement if you select this option. simplefb can correctly deal
2843 with generic system framebuffers. But you should still keep vesafb
2844 and others enabled as fallback if a system framebuffer is
2845 incompatible with simplefb.
2846
2847 If unsure, say Y.
2848
e279b6c1
SR
2849endmenu
2850
2851
1572497c 2852menu "Binary Emulations"
e279b6c1
SR
2853
2854config IA32_EMULATION
2855 bool "IA32 Emulation"
2856 depends on X86_64
39f88911 2857 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2858 select BINFMT_ELF
a97f52e6 2859 select COMPAT_BINFMT_ELF
39f88911 2860 select COMPAT_OLD_SIGACTION
a7f7f624 2861 help
5fd92e65
L
2862 Include code to run legacy 32-bit programs under a
2863 64-bit kernel. You should likely turn this on, unless you're
2864 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2865
2866config IA32_AOUT
8f9ca475
IM
2867 tristate "IA32 a.out support"
2868 depends on IA32_EMULATION
eac61655 2869 depends on BROKEN
a7f7f624 2870 help
8f9ca475 2871 Support old a.out binaries in the 32bit emulation.
e279b6c1 2872
0bf62763 2873config X86_X32
6ea30386 2874 bool "x32 ABI for 64-bit mode"
9b54050b 2875 depends on X86_64
a7f7f624 2876 help
5fd92e65
L
2877 Include code to run binaries for the x32 native 32-bit ABI
2878 for 64-bit processors. An x32 process gets access to the
2879 full 64-bit register file and wide data path while leaving
2880 pointers at 32 bits for smaller memory footprint.
2881
2882 You will need a recent binutils (2.22 or later) with
2883 elf32_x86_64 support enabled to compile a kernel with this
2884 option set.
2885
953fee1d
IM
2886config COMPAT_32
2887 def_bool y
2888 depends on IA32_EMULATION || X86_32
2889 select HAVE_UID16
2890 select OLD_SIGSUSPEND3
2891
e279b6c1 2892config COMPAT
3c2362e6 2893 def_bool y
0bf62763 2894 depends on IA32_EMULATION || X86_X32
e279b6c1 2895
3120e25e 2896if COMPAT
e279b6c1 2897config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2898 def_bool y
e279b6c1
SR
2899
2900config SYSVIPC_COMPAT
3c2362e6 2901 def_bool y
3120e25e 2902 depends on SYSVIPC
3120e25e 2903endif
ee009e4a 2904
e279b6c1
SR
2905endmenu
2906
2907
e5beae16
KP
2908config HAVE_ATOMIC_IOMAP
2909 def_bool y
2910 depends on X86_32
2911
e279b6c1
SR
2912source "drivers/firmware/Kconfig"
2913
edf88417 2914source "arch/x86/kvm/Kconfig"
5e8ebd84
JD
2915
2916source "arch/x86/Kconfig.assembler"