mm: generalize SYS_SUPPORTS_HUGETLBFS (rename as ARCH_SUPPORTS_HUGETLBFS)
[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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11 def_bool y
12 depends on !64BIT
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13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
157e118b 17 select GENERIC_VDSO_32
117ed454 18 select HAVE_DEBUG_STACKOVERFLOW
157e118b 19 select KMAP_LOCAL
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20 select MODULES_USE_ELF_REL
21 select OLD_SIGACTION
2ca408d9 22 select ARCH_SPLIT_ARG64
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23
24config X86_64
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25 def_bool y
26 depends on 64BIT
d94e0685 27 # Options that are inherently 64-bit kernel only:
4eb0716e 28 select ARCH_HAS_GIGANTIC_PAGE
c12d3362 29 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
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IM
30 select ARCH_USE_CMPXCHG_LOCKREF
31 select HAVE_ARCH_SOFT_DIRTY
32 select MODULES_USE_ELF_RELA
f616ab59 33 select NEED_DMA_MAP_STATE
09230cbc 34 select SWIOTLB
7facdc42 35 select ARCH_HAS_ELFCORE_COMPAT
1032c0ba 36
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SRV
37config FORCE_DYNAMIC_FTRACE
38 def_bool y
39 depends on X86_32
40 depends on FUNCTION_TRACER
41 select DYNAMIC_FTRACE
42 help
43 We keep the static function tracing (!DYNAMIC_FTRACE) around
44 in order to test the non static function tracing in the
45 generic code, as other architectures still use it. But we
46 only need to keep it around for x86_64. No need to keep it
47 for x86_32. For x86_32, force DYNAMIC_FTRACE.
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48#
49# Arch settings
50#
51# ( Note that options that are marked 'if X86_64' could in principle be
52# ported to 32-bit as well. )
53#
8d5fffb9 54config X86
3c2362e6 55 def_bool y
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56 #
57 # Note: keep this list sorted alphabetically
58 #
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59 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
60 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 61 select ARCH_32BIT_OFF_T if X86_32
2a21ad57 62 select ARCH_CLOCKSOURCE_INIT
c763ea26 63 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
c2280be8 64 select ARCH_HAS_CACHE_LINE_SIZE
fa5b6ec9 65 select ARCH_HAS_DEBUG_VIRTUAL
399145f9 66 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
21266be9 67 select ARCH_HAS_DEVMEM_IS_ALLOWED
b1a57bbf 68 select ARCH_HAS_EARLY_DEBUG if KGDB
6471b825 69 select ARCH_HAS_ELF_RANDOMIZE
72d93104 70 select ARCH_HAS_FAST_MULTIPLIER
316d097c 71 select ARCH_HAS_FILTER_PGPROT
6974f0c4 72 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 73 select ARCH_HAS_GCOV_PROFILE_ALL
0f1441b4 74 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
0c9c1d56 75 select ARCH_HAS_MEM_ENCRYPT
10bcc80e 76 select ARCH_HAS_MEMBARRIER_SYNC_CORE
0ebeea8c 77 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
c763ea26 78 select ARCH_HAS_PMEM_API if X86_64
17596731 79 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 80 select ARCH_HAS_PTE_SPECIAL
0aed55af 81 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
ec6347bb 82 select ARCH_HAS_COPY_MC if X86_64
d2852a22 83 select ARCH_HAS_SET_MEMORY
d253ca0c 84 select ARCH_HAS_SET_DIRECT_MAP
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LA
85 select ARCH_HAS_STRICT_KERNEL_RWX
86 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 87 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
25c619e5 88 select ARCH_HAS_SYSCALL_WRAPPER
c6d30853 89 select ARCH_HAS_UBSAN_SANITIZE_ALL
7e01ccb4 90 select ARCH_HAS_DEBUG_WX
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IM
91 select ARCH_HAVE_NMI_SAFE_CMPXCHG
92 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 93 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 94 select ARCH_MIGHT_HAVE_PC_SERIO
3599fe12 95 select ARCH_STACKWALK
2c870e61 96 select ARCH_SUPPORTS_ACPI
6471b825 97 select ARCH_SUPPORTS_ATOMIC_RMW
5d6ad668 98 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
6471b825 99 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
14df3267 100 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
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ST
101 select ARCH_SUPPORTS_LTO_CLANG if X86_64
102 select ARCH_SUPPORTS_LTO_CLANG_THIN if X86_64
6471b825 103 select ARCH_USE_BUILTIN_BSWAP
dce44566 104 select ARCH_USE_MEMTEST
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IM
105 select ARCH_USE_QUEUED_RWLOCKS
106 select ARCH_USE_QUEUED_SPINLOCKS
2ce0d7f9 107 select ARCH_USE_SYM_ANNOTATIONS
ce4a4e56 108 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
81c22041 109 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
c763ea26 110 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
3876d4a3 111 select ARCH_WANT_HUGE_PMD_SHARE
59612b24 112 select ARCH_WANT_LD_ORPHAN_WARN
38d8b4e6 113 select ARCH_WANTS_THP_SWAP if X86_64
10916706 114 select BUILDTIME_TABLE_SORT
6471b825 115 select CLKEVT_I8253
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IM
116 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
117 select CLOCKSOURCE_WATCHDOG
6471b825 118 select DCACHE_WORD_ACCESS
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119 select EDAC_ATOMIC_SCRUB
120 select EDAC_SUPPORT
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IM
121 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
122 select GENERIC_CLOCKEVENTS_MIN_ADJUST
123 select GENERIC_CMOS_UPDATE
124 select GENERIC_CPU_AUTOPROBE
61dc0f55 125 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 126 select GENERIC_EARLY_IOREMAP
27d6b4d1 127 select GENERIC_ENTRY
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128 select GENERIC_FIND_FIRST_BIT
129 select GENERIC_IOMAP
c7d6c9dd 130 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 131 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 132 select GENERIC_IRQ_MIGRATION if SMP
6471b825 133 select GENERIC_IRQ_PROBE
c201c917 134 select GENERIC_IRQ_RESERVATION_MODE
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IM
135 select GENERIC_IRQ_SHOW
136 select GENERIC_PENDING_IRQ if SMP
2ae27137 137 select GENERIC_PTDUMP
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138 select GENERIC_SMP_IDLE_THREAD
139 select GENERIC_STRNCPY_FROM_USER
140 select GENERIC_STRNLEN_USER
141 select GENERIC_TIME_VSYSCALL
7ac87074 142 select GENERIC_GETTIMEOFDAY
550a77a7 143 select GENERIC_VDSO_TIME_NS
39656e83 144 select GUP_GET_PTE_LOW_HIGH if X86_PAE
17e5888e 145 select HARDIRQS_SW_RESEND
7edaeb68 146 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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147 select HAVE_ACPI_APEI if ACPI
148 select HAVE_ACPI_APEI_NMI if ACPI
149 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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150 select HAVE_ARCH_AUDITSYSCALL
151 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
152 select HAVE_ARCH_JUMP_LABEL
b34006c4 153 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 154 select HAVE_ARCH_KASAN if X86_64
0609ae01 155 select HAVE_ARCH_KASAN_VMALLOC if X86_64
1dc0da6e 156 select HAVE_ARCH_KFENCE
6471b825 157 select HAVE_ARCH_KGDB
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158 select HAVE_ARCH_MMAP_RND_BITS if MMU
159 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 160 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 161 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 162 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 163 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 164 select HAVE_ARCH_STACKLEAK
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165 select HAVE_ARCH_TRACEHOOK
166 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 167 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
b64d8d1e 168 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
7677f7fd 169 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD
e37e43a4 170 select HAVE_ARCH_VMAP_STACK if X86_64
fe950f60 171 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
c763ea26 172 select HAVE_ARCH_WITHIN_STACK_FRAMES
2ff2b7ec 173 select HAVE_ASM_MODVERSIONS
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IM
174 select HAVE_CMPXCHG_DOUBLE
175 select HAVE_CMPXCHG_LOCAL
176 select HAVE_CONTEXT_TRACKING if X86_64
d1f250e2 177 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
cf4db259 178 select HAVE_C_RECORDMCOUNT
6dafca97 179 select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION
6471b825 180 select HAVE_DEBUG_KMEMLEAK
6471b825 181 select HAVE_DMA_CONTIGUOUS
677aa9f7 182 select HAVE_DYNAMIC_FTRACE
06aeaaea 183 select HAVE_DYNAMIC_FTRACE_WITH_REGS
02a474ca 184 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
562955fe 185 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
03f5781b 186 select HAVE_EBPF_JIT
58340a07 187 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 188 select HAVE_EISA
5f56a5df 189 select HAVE_EXIT_THREAD
67a929e0 190 select HAVE_FAST_GUP
644e0e8d 191 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 192 select HAVE_FTRACE_MCOUNT_RECORD
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193 select HAVE_FUNCTION_GRAPH_TRACER
194 select HAVE_FUNCTION_TRACER
6b90bd4b 195 select HAVE_GCC_PLUGINS
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196 select HAVE_HW_BREAKPOINT
197 select HAVE_IDE
198 select HAVE_IOREMAP_PROT
624db9ea 199 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
6471b825 200 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 201 select HAVE_KERNEL_BZIP2
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IM
202 select HAVE_KERNEL_GZIP
203 select HAVE_KERNEL_LZ4
2e9f3bdd 204 select HAVE_KERNEL_LZMA
13510997 205 select HAVE_KERNEL_LZO
6471b825 206 select HAVE_KERNEL_XZ
fb46d057 207 select HAVE_KERNEL_ZSTD
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208 select HAVE_KPROBES
209 select HAVE_KPROBES_ON_FTRACE
540adea3 210 select HAVE_FUNCTION_ERROR_INJECTION
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211 select HAVE_KRETPROBES
212 select HAVE_KVM
213 select HAVE_LIVEPATCH if X86_64
0102752e 214 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 215 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 216 select HAVE_MOVE_PMD
be37c98d 217 select HAVE_MOVE_PUD
42a0bb3f 218 select HAVE_NMI
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IM
219 select HAVE_OPTPROBES
220 select HAVE_PCSPKR_PLATFORM
221 select HAVE_PERF_EVENTS
c01d4323 222 select HAVE_PERF_EVENTS_NMI
92e5aae4 223 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 224 select HAVE_PCI
c5e63197 225 select HAVE_PERF_REGS
c5ebcedb 226 select HAVE_PERF_USER_STACK_DUMP
ff2e6d72 227 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
00998085 228 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
6471b825 229 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 230 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 231 select HAVE_FUNCTION_ARG_ACCESS_API
cd1a41ce 232 select HAVE_SOFTIRQ_ON_OWN_STACK
d148eac0 233 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 234 select HAVE_STACK_VALIDATION if X86_64
e6d6c071 235 select HAVE_STATIC_CALL
1e7e4788 236 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
6ef869e0 237 select HAVE_PREEMPT_DYNAMIC
d6761b8f 238 select HAVE_RSEQ
6471b825 239 select HAVE_SYSCALL_TRACEPOINTS
6471b825 240 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 241 select HAVE_USER_RETURN_NOTIFIER
7ac87074 242 select HAVE_GENERIC_VDSO
05736e4a 243 select HOTPLUG_SMT if SMP
c0185808 244 select IRQ_FORCED_THREADING
86596f0a 245 select NEED_SG_DMA_LENGTH
2eac9c2d 246 select PCI_DOMAINS if PCI
625210cf 247 select PCI_LOCKLESS_CONFIG if PCI
6471b825 248 select PERF_EVENTS
3195ef59 249 select RTC_LIB
d6faca40 250 select RTC_MC146818_LIB
6471b825 251 select SPARSE_IRQ
83fe27ea 252 select SRCU
1e7e4788 253 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
6471b825 254 select SYSCTL_EXCEPTION_TRACE
15f4eae7 255 select THREAD_INFO_IN_TASK
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IM
256 select USER_STACKTRACE_SUPPORT
257 select VIRT_TO_BUS
3b02a051 258 select HAVE_ARCH_KCSAN if X86_64
6471b825 259 select X86_FEATURE_NAMES if PROC_FS
0c608dad 260 select PROC_PID_ARCH_STATUS if PROC_FS
9e2b4be3 261 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
7d8330a5 262
ba7e4d13 263config INSTRUCTION_DECODER
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264 def_bool y
265 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 266
51b26ada
LT
267config OUTPUT_FORMAT
268 string
269 default "elf32-i386" if X86_32
270 default "elf64-x86-64" if X86_64
271
8d5fffb9 272config LOCKDEP_SUPPORT
3c2362e6 273 def_bool y
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SR
274
275config STACKTRACE_SUPPORT
3c2362e6 276 def_bool y
8d5fffb9 277
8d5fffb9 278config MMU
3c2362e6 279 def_bool y
8d5fffb9 280
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DC
281config ARCH_MMAP_RND_BITS_MIN
282 default 28 if 64BIT
283 default 8
284
285config ARCH_MMAP_RND_BITS_MAX
286 default 32 if 64BIT
287 default 16
288
289config ARCH_MMAP_RND_COMPAT_BITS_MIN
290 default 8
291
292config ARCH_MMAP_RND_COMPAT_BITS_MAX
293 default 16
294
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SR
295config SBUS
296 bool
297
298config GENERIC_ISA_DMA
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JB
299 def_bool y
300 depends on ISA_DMA_API
8d5fffb9 301
8d5fffb9 302config GENERIC_BUG
3c2362e6 303 def_bool y
8d5fffb9 304 depends on BUG
b93a531e
JB
305 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
306
307config GENERIC_BUG_RELATIVE_POINTERS
308 bool
8d5fffb9 309
8d5fffb9 310config ARCH_MAY_HAVE_PC_FDC
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311 def_bool y
312 depends on ISA_DMA_API
8d5fffb9 313
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SR
314config GENERIC_CALIBRATE_DELAY
315 def_bool y
316
9a0b8415 317config ARCH_HAS_CPU_RELAX
318 def_bool y
319
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DH
320config ARCH_HAS_FILTER_PGPROT
321 def_bool y
322
dd5af90a 323config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 324 def_bool y
b32ef636 325
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TH
326config NEED_PER_CPU_EMBED_FIRST_CHUNK
327 def_bool y
328
329config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
330 def_bool y
331
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JB
332config ARCH_HIBERNATION_POSSIBLE
333 def_bool y
801e4062 334
f4cb5700
JB
335config ARCH_SUSPEND_POSSIBLE
336 def_bool y
f4cb5700 337
53313b2c
SC
338config ARCH_WANT_GENERAL_HUGETLB
339 def_bool y
340
8d5fffb9 341config ZONE_DMA32
e0fd24a3 342 def_bool y if X86_64
8d5fffb9 343
8d5fffb9 344config AUDIT_ARCH
e0fd24a3 345 def_bool y if X86_64
8d5fffb9 346
d6f2d75a
AR
347config KASAN_SHADOW_OFFSET
348 hex
349 depends on KASAN
350 default 0xdffffc0000000000
351
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352config HAVE_INTEL_TXT
353 def_bool y
6ea30386 354 depends on INTEL_IOMMU && ACPI
69575d38 355
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SR
356config X86_32_SMP
357 def_bool y
358 depends on X86_32 && SMP
359
360config X86_64_SMP
361 def_bool y
362 depends on X86_64 && SMP
363
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SD
364config ARCH_SUPPORTS_UPROBES
365 def_bool y
366
d20642f0
RH
367config FIX_EARLYCON_MEM
368 def_bool y
369
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KS
370config DYNAMIC_PHYSICAL_MASK
371 bool
372
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373config PGTABLE_LEVELS
374 int
77ef56e4 375 default 5 if X86_5LEVEL
98233368
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376 default 4 if X86_64
377 default 3 if X86_PAE
378 default 2
379
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MY
380config CC_HAS_SANE_STACKPROTECTOR
381 bool
382 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
383 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
384 help
385 We have to make sure stack protector is unconditionally disabled if
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AL
386 the compiler produces broken code or if it does not let us control
387 the segment on 32-bit kernels.
2a61f474 388
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SR
389menu "Processor type and features"
390
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RD
391config ZONE_DMA
392 bool "DMA memory allocation support" if EXPERT
393 default y
394 help
395 DMA memory allocation support allows devices with less than 32-bit
396 addressing to allocate within the first 16MB of address space.
397 Disable if no such devices will be used.
398
399 If unsure, say Y.
400
506f1d07
SR
401config SMP
402 bool "Symmetric multi-processing support"
a7f7f624 403 help
506f1d07 404 This enables support for systems with more than one CPU. If you have
4a474157
RG
405 a system with only one CPU, say N. If you have a system with more
406 than one CPU, say Y.
506f1d07 407
4a474157 408 If you say N here, the kernel will run on uni- and multiprocessor
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SR
409 machines, but will use only one CPU of a multiprocessor machine. If
410 you say Y here, the kernel will run on many, but not all,
4a474157 411 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
412 will run faster if you say N here.
413
414 Note that if you say Y here and choose architecture "586" or
415 "Pentium" under "Processor family", the kernel will not work on 486
416 architectures. Similarly, multiprocessor kernels for the "PPro"
417 architecture may not work on all Pentium based boards.
418
419 People using multiprocessor machines who say Y here should also say
420 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
421 Management" code will be disabled if you say Y here.
422
cb1aaebe 423 See also <file:Documentation/x86/i386/IO-APIC.rst>,
4f4cfa6c 424 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
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SR
425 <http://www.tldp.org/docs.html#howto>.
426
427 If you don't know what to do here, say N.
428
9def39be
JT
429config X86_FEATURE_NAMES
430 bool "Processor feature human-readable names" if EMBEDDED
431 default y
a7f7f624 432 help
9def39be
JT
433 This option compiles in a table of x86 feature bits and corresponding
434 names. This is required to support /proc/cpuinfo and a few kernel
435 messages. You can disable this to save space, at the expense of
436 making those few kernel messages show numeric feature bits instead.
437
438 If in doubt, say Y.
439
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YL
440config X86_X2APIC
441 bool "Support x2apic"
19e3d60d 442 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
a7f7f624 443 help
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YL
444 This enables x2apic support on CPUs that have this feature.
445
446 This allows 32-bit apic IDs (so it can support very large systems),
447 and accesses the local apic via MSRs not via mmio.
448
06cd9a7d
YL
449 If you don't know what to do here, say N.
450
6695c85b 451config X86_MPPARSE
4590d98f 452 bool "Enable MPS table" if ACPI
7a527688 453 default y
5ab74722 454 depends on X86_LOCAL_APIC
a7f7f624 455 help
6695c85b
YL
456 For old smp systems that do not have proper acpi support. Newer systems
457 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 458
ddd70cf9 459config GOLDFISH
b03b016f
KK
460 def_bool y
461 depends on X86_GOLDFISH
ddd70cf9 462
76b04384
DW
463config RETPOLINE
464 bool "Avoid speculative indirect branches in kernel"
465 default y
466 help
467 Compile kernel with the retpoline compiler options to guard against
468 kernel-to-user data leaks by avoiding speculative indirect
469 branches. Requires a compiler with -mindirect-branch=thunk-extern
470 support for full protection. The kernel may run slower.
471
e6d42931
JW
472config X86_CPU_RESCTRL
473 bool "x86 CPU resource control support"
6fe07ce3 474 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 475 select KERNFS
e79f15a4 476 select PROC_CPU_RESCTRL if PROC_FS
78e99b4a 477 help
e6d42931 478 Enable x86 CPU resource control support.
6fe07ce3
BM
479
480 Provide support for the allocation and monitoring of system resources
481 usage by the CPU.
482
483 Intel calls this Intel Resource Director Technology
484 (Intel(R) RDT). More information about RDT can be found in the
485 Intel x86 Architecture Software Developer Manual.
486
487 AMD calls this AMD Platform Quality of Service (AMD QoS).
488 More information about AMD QoS can be found in the AMD64 Technology
489 Platform Quality of Service Extensions manual.
78e99b4a
FY
490
491 Say N if unsure.
492
8425091f 493if X86_32
a0d0bb4d
RD
494config X86_BIGSMP
495 bool "Support for big SMP systems with more than 8 CPUs"
496 depends on SMP
a7f7f624 497 help
e133f6ea 498 This option is needed for the systems that have more than 8 CPUs.
a0d0bb4d 499
c5c606d9
RT
500config X86_EXTENDED_PLATFORM
501 bool "Support for extended (non-PC) x86 platforms"
502 default y
a7f7f624 503 help
06ac8346
IM
504 If you disable this option then the kernel will only support
505 standard PC platforms. (which covers the vast majority of
506 systems out there.)
507
8425091f
RT
508 If you enable this option then you'll be able to select support
509 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 510 Goldfish (Android emulator)
8425091f 511 AMD Elan
8425091f
RT
512 RDC R-321x SoC
513 SGI 320/540 (Visual Workstation)
83125a3a 514 STA2X11-based (e.g. Northville)
3f4110a4 515 Moorestown MID devices
06ac8346
IM
516
517 If you have one of these systems, or if you want to build a
518 generic distribution kernel, say Y here - otherwise say N.
8425091f 519endif
06ac8346 520
8425091f
RT
521if X86_64
522config X86_EXTENDED_PLATFORM
523 bool "Support for extended (non-PC) x86 platforms"
524 default y
a7f7f624 525 help
8425091f
RT
526 If you disable this option then the kernel will only support
527 standard PC platforms. (which covers the vast majority of
528 systems out there.)
529
530 If you enable this option then you'll be able to select support
531 for the following (non-PC) 64 bit x86 platforms:
44b111b5 532 Numascale NumaChip
8425091f
RT
533 ScaleMP vSMP
534 SGI Ultraviolet
535
536 If you have one of these systems, or if you want to build a
537 generic distribution kernel, say Y here - otherwise say N.
538endif
c5c606d9
RT
539# This is an alphabetically sorted list of 64 bit extended platforms
540# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
541config X86_NUMACHIP
542 bool "Numascale NumaChip"
543 depends on X86_64
544 depends on X86_EXTENDED_PLATFORM
545 depends on NUMA
546 depends on SMP
547 depends on X86_X2APIC
f9726bfd 548 depends on PCI_MMCONFIG
a7f7f624 549 help
44b111b5
SP
550 Adds support for Numascale NumaChip large-SMP systems. Needed to
551 enable more than ~168 cores.
552 If you don't have one of these, you should say N here.
506f1d07 553
c5c606d9
RT
554config X86_VSMP
555 bool "ScaleMP vSMP"
6276a074 556 select HYPERVISOR_GUEST
c5c606d9
RT
557 select PARAVIRT
558 depends on X86_64 && PCI
559 depends on X86_EXTENDED_PLATFORM
ead91d4b 560 depends on SMP
a7f7f624 561 help
c5c606d9
RT
562 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
563 supposed to run on these EM64T-based machines. Only choose this option
564 if you have one of these machines.
5e3a77e9 565
03b48632
NP
566config X86_UV
567 bool "SGI Ultraviolet"
568 depends on X86_64
c5c606d9 569 depends on X86_EXTENDED_PLATFORM
54c28d29 570 depends on NUMA
1ecb4ae5 571 depends on EFI
c2209ea5 572 depends on KEXEC_CORE
9d6c26e7 573 depends on X86_X2APIC
1222e564 574 depends on PCI
a7f7f624 575 help
03b48632
NP
576 This option is needed in order to support SGI Ultraviolet systems.
577 If you don't have one of these, you should say N here.
578
c5c606d9
RT
579# Following is an alphabetically sorted list of 32 bit extended platforms
580# Please maintain the alphabetic order if and when there are additions
506f1d07 581
ddd70cf9 582config X86_GOLDFISH
b03b016f
KK
583 bool "Goldfish (Virtual Platform)"
584 depends on X86_EXTENDED_PLATFORM
a7f7f624 585 help
ddd70cf9
JN
586 Enable support for the Goldfish virtual platform used primarily
587 for Android development. Unless you are building for the Android
588 Goldfish emulator say N here.
589
c751e17b
TG
590config X86_INTEL_CE
591 bool "CE4100 TV platform"
592 depends on PCI
593 depends on PCI_GODIRECT
6084a6e2 594 depends on X86_IO_APIC
c751e17b
TG
595 depends on X86_32
596 depends on X86_EXTENDED_PLATFORM
37bc9f50 597 select X86_REBOOTFIXUPS
da6b737b
SAS
598 select OF
599 select OF_EARLY_FLATTREE
a7f7f624 600 help
c751e17b
TG
601 Select for the Intel CE media processor (CE4100) SOC.
602 This option compiles in support for the CE4100 SOC for settop
603 boxes and media devices.
604
4cb9b00f 605config X86_INTEL_MID
43605ef1 606 bool "Intel MID platform support"
43605ef1 607 depends on X86_EXTENDED_PLATFORM
edc6bc78 608 depends on X86_PLATFORM_DEVICES
1ea7c673 609 depends on PCI
3fda5bb4 610 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 611 depends on X86_IO_APIC
4cb9b00f 612 select I2C
7c9c3a1e 613 select DW_APB_TIMER
1ea7c673 614 select APB_TIMER
54b34aa0 615 select INTEL_SCU_PCI
15a713df 616 select MFD_INTEL_MSIC
a7f7f624 617 help
4cb9b00f
DC
618 Select to build a kernel capable of supporting Intel MID (Mobile
619 Internet Device) platform systems which do not have the PCI legacy
620 interfaces. If you are building for a PC class system say N here.
1ea7c673 621
4cb9b00f
DC
622 Intel MID platforms are based on an Intel processor and chipset which
623 consume less power than most of the x86 derivatives.
43605ef1 624
8bbc2a13
BD
625config X86_INTEL_QUARK
626 bool "Intel Quark platform support"
627 depends on X86_32
628 depends on X86_EXTENDED_PLATFORM
629 depends on X86_PLATFORM_DEVICES
630 depends on X86_TSC
631 depends on PCI
632 depends on PCI_GOANY
633 depends on X86_IO_APIC
634 select IOSF_MBI
635 select INTEL_IMR
9ab6eb51 636 select COMMON_CLK
a7f7f624 637 help
8bbc2a13
BD
638 Select to include support for Quark X1000 SoC.
639 Say Y here if you have a Quark based system such as the Arduino
640 compatible Intel Galileo.
641
3d48aab1
MW
642config X86_INTEL_LPSS
643 bool "Intel Low Power Subsystem Support"
5962dd22 644 depends on X86 && ACPI && PCI
3d48aab1 645 select COMMON_CLK
0f531431 646 select PINCTRL
eebb3e8d 647 select IOSF_MBI
a7f7f624 648 help
3d48aab1
MW
649 Select to build support for Intel Low Power Subsystem such as
650 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
651 things like clock tree (common clock framework) and pincontrol
652 which are needed by the LPSS peripheral drivers.
3d48aab1 653
92082a88
KX
654config X86_AMD_PLATFORM_DEVICE
655 bool "AMD ACPI2Platform devices support"
656 depends on ACPI
657 select COMMON_CLK
658 select PINCTRL
a7f7f624 659 help
92082a88
KX
660 Select to interpret AMD specific ACPI device to platform device
661 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
662 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
663 implemented under PINCTRL subsystem.
664
ced3ce76
DB
665config IOSF_MBI
666 tristate "Intel SoC IOSF Sideband support for SoC platforms"
667 depends on PCI
a7f7f624 668 help
ced3ce76
DB
669 This option enables sideband register access support for Intel SoC
670 platforms. On these platforms the IOSF sideband is used in lieu of
671 MSR's for some register accesses, mostly but not limited to thermal
672 and power. Drivers may query the availability of this device to
673 determine if they need the sideband in order to work on these
674 platforms. The sideband is available on the following SoC products.
675 This list is not meant to be exclusive.
676 - BayTrail
677 - Braswell
678 - Quark
679
680 You should say Y if you are running a kernel on one of these SoC's.
681
ed2226bd
DB
682config IOSF_MBI_DEBUG
683 bool "Enable IOSF sideband access through debugfs"
684 depends on IOSF_MBI && DEBUG_FS
a7f7f624 685 help
ed2226bd
DB
686 Select this option to expose the IOSF sideband access registers (MCR,
687 MDR, MCRX) through debugfs to write and read register information from
688 different units on the SoC. This is most useful for obtaining device
689 state information for debug and analysis. As this is a general access
690 mechanism, users of this option would have specific knowledge of the
691 device they want to access.
692
693 If you don't require the option or are in doubt, say N.
694
c5c606d9
RT
695config X86_RDC321X
696 bool "RDC R-321x SoC"
506f1d07 697 depends on X86_32
c5c606d9
RT
698 depends on X86_EXTENDED_PLATFORM
699 select M486
700 select X86_REBOOTFIXUPS
a7f7f624 701 help
c5c606d9
RT
702 This option is needed for RDC R-321x system-on-chip, also known
703 as R-8610-(G).
704 If you don't have one of these chips, you should say N here.
705
e0c7ae37 706config X86_32_NON_STANDARD
9c398017
IM
707 bool "Support non-standard 32-bit SMP architectures"
708 depends on X86_32 && SMP
c5c606d9 709 depends on X86_EXTENDED_PLATFORM
a7f7f624 710 help
b5660ba7
PA
711 This option compiles in the bigsmp and STA2X11 default
712 subarchitectures. It is intended for a generic binary
713 kernel. If you select them all, kernel will probe it one by
714 one and will fallback to default.
d49c4288 715
c5c606d9 716# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 717
d949f36f 718config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 719 def_bool y
d949f36f
LT
720 # MCE code calls memory_failure():
721 depends on X86_MCE
722 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
723 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
724 depends on X86_64 || !SPARSEMEM
725 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 726
83125a3a
AR
727config STA2X11
728 bool "STA2X11 Companion Chip Support"
729 depends on X86_32_NON_STANDARD && PCI
83125a3a
AR
730 select SWIOTLB
731 select MFD_STA2X11
0145071b 732 select GPIOLIB
a7f7f624 733 help
83125a3a
AR
734 This adds support for boards based on the STA2X11 IO-Hub,
735 a.k.a. "ConneXt". The chip is used in place of the standard
736 PC chipset, so all "standard" peripherals are missing. If this
737 option is selected the kernel will still be able to boot on
738 standard PC machines.
739
82148d1d
S
740config X86_32_IRIS
741 tristate "Eurobraille/Iris poweroff module"
742 depends on X86_32
a7f7f624 743 help
82148d1d
S
744 The Iris machines from EuroBraille do not have APM or ACPI support
745 to shut themselves down properly. A special I/O sequence is
746 needed to do so, which is what this module does at
747 kernel shutdown.
748
749 This is only for Iris machines from EuroBraille.
750
751 If unused, say N.
752
ae1e9130 753config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
754 def_bool y
755 prompt "Single-depth WCHAN output"
a87d0914 756 depends on X86
a7f7f624 757 help
506f1d07
SR
758 Calculate simpler /proc/<PID>/wchan values. If this option
759 is disabled then wchan values will recurse back to the
760 caller function. This provides more accurate wchan values,
761 at the expense of slightly more scheduling overhead.
762
763 If in doubt, say "Y".
764
6276a074
BP
765menuconfig HYPERVISOR_GUEST
766 bool "Linux guest support"
a7f7f624 767 help
6276a074
BP
768 Say Y here to enable options for running Linux under various hyper-
769 visors. This option enables basic hypervisor detection and platform
770 setup.
506f1d07 771
6276a074
BP
772 If you say N, all options in this submenu will be skipped and
773 disabled, and Linux guest support won't be built in.
506f1d07 774
6276a074 775if HYPERVISOR_GUEST
506f1d07 776
e61bd94a
EPH
777config PARAVIRT
778 bool "Enable paravirtualization code"
a0e2bf7c 779 depends on HAVE_STATIC_CALL
a7f7f624 780 help
e61bd94a
EPH
781 This changes the kernel so it can modify itself when it is run
782 under a hypervisor, potentially improving performance significantly
783 over full virtualization. However, when run without a hypervisor
784 the kernel is theoretically slower and slightly larger.
785
c00a280a
JG
786config PARAVIRT_XXL
787 bool
788
6276a074
BP
789config PARAVIRT_DEBUG
790 bool "paravirt-ops debugging"
791 depends on PARAVIRT && DEBUG_KERNEL
a7f7f624 792 help
6276a074
BP
793 Enable to debug paravirt_ops internals. Specifically, BUG if
794 a paravirt_op is missing when it is called.
795
b4ecc126
JF
796config PARAVIRT_SPINLOCKS
797 bool "Paravirtualization layer for spinlocks"
6ea30386 798 depends on PARAVIRT && SMP
a7f7f624 799 help
b4ecc126
JF
800 Paravirtualized spinlocks allow a pvops backend to replace the
801 spinlock implementation with something virtualization-friendly
802 (for example, block the virtual CPU rather than spinning).
803
4c4e4f61
R
804 It has a minimal impact on native kernels and gives a nice performance
805 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 806
4c4e4f61 807 If you are unsure how to answer this question, answer Y.
b4ecc126 808
ecca2502
ZY
809config X86_HV_CALLBACK_VECTOR
810 def_bool n
811
6276a074 812source "arch/x86/xen/Kconfig"
7af192c9 813
6276a074
BP
814config KVM_GUEST
815 bool "KVM Guest support (including kvmclock)"
816 depends on PARAVIRT
817 select PARAVIRT_CLOCK
a1c4423b 818 select ARCH_CPUIDLE_HALTPOLL
b1d40575 819 select X86_HV_CALLBACK_VECTOR
6276a074 820 default y
a7f7f624 821 help
6276a074
BP
822 This option enables various optimizations for running under the KVM
823 hypervisor. It includes a paravirtualized clock, so that instead
824 of relying on a PIT (or probably other) emulation by the
825 underlying device model, the host provides the guest with
826 timing infrastructure such as time of day, and system time
506f1d07 827
a1c4423b 828config ARCH_CPUIDLE_HALTPOLL
b03b016f
KK
829 def_bool n
830 prompt "Disable host haltpoll when loading haltpoll driver"
831 help
a1c4423b
MT
832 If virtualized under KVM, disable host haltpoll.
833
7733607f
MW
834config PVH
835 bool "Support for running PVH guests"
a7f7f624 836 help
7733607f
MW
837 This option enables the PVH entry point for guest virtual machines
838 as specified in the x86/HVM direct boot ABI.
839
6276a074
BP
840config PARAVIRT_TIME_ACCOUNTING
841 bool "Paravirtual steal time accounting"
842 depends on PARAVIRT
a7f7f624 843 help
6276a074
BP
844 Select this option to enable fine granularity task steal time
845 accounting. Time spent executing other tasks in parallel with
846 the current vCPU is discounted from the vCPU power. To account for
847 that, there can be a small performance impact.
848
849 If in doubt, say N here.
850
851config PARAVIRT_CLOCK
852 bool
97349135 853
4a362601
JK
854config JAILHOUSE_GUEST
855 bool "Jailhouse non-root cell support"
abde587b 856 depends on X86_64 && PCI
87e65d05 857 select X86_PM_TIMER
a7f7f624 858 help
4a362601
JK
859 This option allows to run Linux as guest in a Jailhouse non-root
860 cell. You can leave this option disabled if you only want to start
861 Jailhouse and run Linux afterwards in the root cell.
862
ec7972c9
ZY
863config ACRN_GUEST
864 bool "ACRN Guest support"
865 depends on X86_64
498ad393 866 select X86_HV_CALLBACK_VECTOR
ec7972c9
ZY
867 help
868 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
869 a flexible, lightweight reference open-source hypervisor, built with
870 real-time and safety-criticality in mind. It is built for embedded
871 IOT with small footprint and real-time features. More details can be
872 found in https://projectacrn.org/.
873
6276a074 874endif #HYPERVISOR_GUEST
97349135 875
506f1d07
SR
876source "arch/x86/Kconfig.cpu"
877
878config HPET_TIMER
3c2362e6 879 def_bool X86_64
506f1d07 880 prompt "HPET Timer Support" if X86_32
a7f7f624 881 help
8f9ca475
IM
882 Use the IA-PC HPET (High Precision Event Timer) to manage
883 time in preference to the PIT and RTC, if a HPET is
884 present.
885 HPET is the next generation timer replacing legacy 8254s.
886 The HPET provides a stable time base on SMP
887 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
888 as it is off-chip. The interface used is documented
889 in the HPET spec, revision 1.
506f1d07 890
8f9ca475
IM
891 You can safely choose Y here. However, HPET will only be
892 activated if the platform and the BIOS support this feature.
893 Otherwise the 8254 will be used for timing services.
506f1d07 894
8f9ca475 895 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
896
897config HPET_EMULATE_RTC
3c2362e6 898 def_bool y
3228e1dc 899 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 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
07dc900e 1155source "arch/x86/events/Kconfig"
e633c65a 1156
5aef51c3 1157config X86_LEGACY_VM86
1e642812 1158 bool "Legacy VM86 support"
506f1d07 1159 depends on X86_32
a7f7f624 1160 help
5aef51c3
AL
1161 This option allows user programs to put the CPU into V8086
1162 mode, which is an 80286-era approximation of 16-bit real mode.
1163
1164 Some very old versions of X and/or vbetool require this option
1165 for user mode setting. Similarly, DOSEMU will use it if
1166 available to accelerate real mode DOS programs. However, any
1167 recent version of DOSEMU, X, or vbetool should be fully
1168 functional even without kernel VM86 support, as they will all
1e642812
IM
1169 fall back to software emulation. Nevertheless, if you are using
1170 a 16-bit DOS program where 16-bit performance matters, vm86
1171 mode might be faster than emulation and you might want to
1172 enable this option.
5aef51c3 1173
1e642812
IM
1174 Note that any app that works on a 64-bit kernel is unlikely to
1175 need this option, as 64-bit kernels don't, and can't, support
1176 V8086 mode. This option is also unrelated to 16-bit protected
1177 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1178
1e642812
IM
1179 Enabling this option increases the complexity of the kernel
1180 and slows down exception handling a tiny bit.
5aef51c3 1181
1e642812 1182 If unsure, say N here.
5aef51c3
AL
1183
1184config VM86
b03b016f
KK
1185 bool
1186 default X86_LEGACY_VM86
34273f41
PA
1187
1188config X86_16BIT
1189 bool "Enable support for 16-bit segments" if EXPERT
1190 default y
a5b9e5a2 1191 depends on MODIFY_LDT_SYSCALL
a7f7f624 1192 help
34273f41
PA
1193 This option is required by programs like Wine to run 16-bit
1194 protected mode legacy code on x86 processors. Disabling
1195 this option saves about 300 bytes on i386, or around 6K text
1196 plus 16K runtime memory on x86-64,
1197
1198config X86_ESPFIX32
1199 def_bool y
1200 depends on X86_16BIT && X86_32
506f1d07 1201
197725de
PA
1202config X86_ESPFIX64
1203 def_bool y
34273f41 1204 depends on X86_16BIT && X86_64
506f1d07 1205
1ad83c85 1206config X86_VSYSCALL_EMULATION
b03b016f
KK
1207 bool "Enable vsyscall emulation" if EXPERT
1208 default y
1209 depends on X86_64
a7f7f624 1210 help
1ad83c85
AL
1211 This enables emulation of the legacy vsyscall page. Disabling
1212 it is roughly equivalent to booting with vsyscall=none, except
1213 that it will also disable the helpful warning if a program
1214 tries to use a vsyscall. With this option set to N, offending
1215 programs will just segfault, citing addresses of the form
1216 0xffffffffff600?00.
1217
1218 This option is required by many programs built before 2013, and
1219 care should be used even with newer programs if set to N.
1220
1221 Disabling this option saves about 7K of kernel size and
1222 possibly 4K of additional runtime pagetable memory.
1223
111e7b15
TG
1224config X86_IOPL_IOPERM
1225 bool "IOPERM and IOPL Emulation"
a24ca997 1226 default y
a7f7f624 1227 help
111e7b15
TG
1228 This enables the ioperm() and iopl() syscalls which are necessary
1229 for legacy applications.
1230
c8137ace
TG
1231 Legacy IOPL support is an overbroad mechanism which allows user
1232 space aside of accessing all 65536 I/O ports also to disable
1233 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1234 capabilities and permission from potentially active security
1235 modules.
1236
1237 The emulation restricts the functionality of the syscall to
1238 only allowing the full range I/O port access, but prevents the
a24ca997
TG
1239 ability to disable interrupts from user space which would be
1240 granted if the hardware IOPL mechanism would be used.
c8137ace 1241
506f1d07
SR
1242config TOSHIBA
1243 tristate "Toshiba Laptop support"
1244 depends on X86_32
a7f7f624 1245 help
506f1d07
SR
1246 This adds a driver to safely access the System Management Mode of
1247 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248 not work on models with a Phoenix BIOS. The System Management Mode
1249 is used to set the BIOS and power saving options on Toshiba portables.
1250
1251 For information on utilities to make use of this driver see the
1252 Toshiba Linux utilities web site at:
1253 <http://www.buzzard.org.uk/toshiba/>.
1254
1255 Say Y if you intend to run this kernel on a Toshiba portable.
1256 Say N otherwise.
1257
1258config I8K
039ae585 1259 tristate "Dell i8k legacy laptop support"
949a9d70 1260 select HWMON
039ae585 1261 select SENSORS_DELL_SMM
a7f7f624 1262 help
039ae585
PR
1263 This option enables legacy /proc/i8k userspace interface in hwmon
1264 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265 temperature and allows controlling fan speeds of Dell laptops via
1266 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267 it reports also power and hotkey status. For fan speed control is
1268 needed userspace package i8kutils.
1269
1270 Say Y if you intend to run this kernel on old Dell laptops or want to
1271 use userspace package i8kutils.
506f1d07
SR
1272 Say N otherwise.
1273
1274config X86_REBOOTFIXUPS
9ba16087
JB
1275 bool "Enable X86 board specific fixups for reboot"
1276 depends on X86_32
a7f7f624 1277 help
506f1d07
SR
1278 This enables chipset and/or board specific fixups to be done
1279 in order to get reboot to work correctly. This is only needed on
1280 some combinations of hardware and BIOS. The symptom, for which
1281 this config is intended, is when reboot ends with a stalled/hung
1282 system.
1283
1284 Currently, the only fixup is for the Geode machines using
5e3a77e9 1285 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1286
1287 Say Y if you want to enable the fixup. Currently, it's safe to
1288 enable this option even if you don't need it.
1289 Say N otherwise.
1290
1291config MICROCODE
9a2bc335
BP
1292 bool "CPU microcode loading support"
1293 default y
80030e3d 1294 depends on CPU_SUP_AMD || CPU_SUP_INTEL
a7f7f624 1295 help
506f1d07 1296 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1297 Intel and AMD processors. The Intel support is for the IA32 family,
1298 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1299 AMD support is for families 0x10 and later. You will obviously need
1300 the actual microcode binary data itself which is not shipped with
1301 the Linux kernel.
1302
1303 The preferred method to load microcode from a detached initrd is described
cb1aaebe 1304 in Documentation/x86/microcode.rst. For that you need to enable
5f9c01aa
BP
1305 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1306 initrd for microcode blobs.
1307
c508c46e
BG
1308 In addition, you can build the microcode into the kernel. For that you
1309 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1310 config option.
506f1d07 1311
8d86f390 1312config MICROCODE_INTEL
e43f6e67 1313 bool "Intel microcode loading support"
8f9ca475
IM
1314 depends on MICROCODE
1315 default MICROCODE
a7f7f624 1316 help
8f9ca475
IM
1317 This options enables microcode patch loading support for Intel
1318 processors.
1319
b8989db9
A
1320 For the current Intel microcode data package go to
1321 <https://downloadcenter.intel.com> and search for
1322 'Linux Processor Microcode Data File'.
8d86f390 1323
80cc9f10 1324config MICROCODE_AMD
e43f6e67 1325 bool "AMD microcode loading support"
8f9ca475 1326 depends on MICROCODE
a7f7f624 1327 help
8f9ca475
IM
1328 If you select this option, microcode patch loading support for AMD
1329 processors will be enabled.
80cc9f10 1330
8f9ca475 1331config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1332 bool "Ancient loading interface (DEPRECATED)"
1333 default n
506f1d07 1334 depends on MICROCODE
a7f7f624 1335 help
c02f48e0
BP
1336 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1337 which was used by userspace tools like iucode_tool and microcode.ctl.
1338 It is inadequate because it runs too late to be able to properly
1339 load microcode on a machine and it needs special tools. Instead, you
1340 should've switched to the early loading method with the initrd or
cb1aaebe 1341 builtin microcode by now: Documentation/x86/microcode.rst
506f1d07
SR
1342
1343config X86_MSR
1344 tristate "/dev/cpu/*/msr - Model-specific register support"
a7f7f624 1345 help
506f1d07
SR
1346 This device gives privileged processes access to the x86
1347 Model-Specific Registers (MSRs). It is a character device with
1348 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1349 MSR accesses are directed to a specific CPU on multi-processor
1350 systems.
1351
1352config X86_CPUID
1353 tristate "/dev/cpu/*/cpuid - CPU information support"
a7f7f624 1354 help
506f1d07
SR
1355 This device gives processes access to the x86 CPUID instruction to
1356 be executed on a specific processor. It is a character device
1357 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1358 /dev/cpu/31/cpuid.
1359
1360choice
1361 prompt "High Memory Support"
6fc108a0 1362 default HIGHMEM4G
506f1d07
SR
1363 depends on X86_32
1364
1365config NOHIGHMEM
1366 bool "off"
a7f7f624 1367 help
506f1d07
SR
1368 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1369 However, the address space of 32-bit x86 processors is only 4
1370 Gigabytes large. That means that, if you have a large amount of
1371 physical memory, not all of it can be "permanently mapped" by the
1372 kernel. The physical memory that's not permanently mapped is called
1373 "high memory".
1374
1375 If you are compiling a kernel which will never run on a machine with
1376 more than 1 Gigabyte total physical RAM, answer "off" here (default
1377 choice and suitable for most users). This will result in a "3GB/1GB"
1378 split: 3GB are mapped so that each process sees a 3GB virtual memory
1379 space and the remaining part of the 4GB virtual memory space is used
1380 by the kernel to permanently map as much physical memory as
1381 possible.
1382
1383 If the machine has between 1 and 4 Gigabytes physical RAM, then
1384 answer "4GB" here.
1385
1386 If more than 4 Gigabytes is used then answer "64GB" here. This
1387 selection turns Intel PAE (Physical Address Extension) mode on.
1388 PAE implements 3-level paging on IA32 processors. PAE is fully
1389 supported by Linux, PAE mode is implemented on all recent Intel
1390 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1391 then the kernel will not boot on CPUs that don't support PAE!
1392
1393 The actual amount of total physical memory will either be
1394 auto detected or can be forced by using a kernel command line option
1395 such as "mem=256M". (Try "man bootparam" or see the documentation of
1396 your boot loader (lilo or loadlin) about how to pass options to the
1397 kernel at boot time.)
1398
1399 If unsure, say "off".
1400
1401config HIGHMEM4G
1402 bool "4GB"
a7f7f624 1403 help
506f1d07
SR
1404 Select this if you have a 32-bit processor and between 1 and 4
1405 gigabytes of physical RAM.
1406
1407config HIGHMEM64G
1408 bool "64GB"
0ef3439c 1409 depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1410 select X86_PAE
a7f7f624 1411 help
506f1d07
SR
1412 Select this if you have a 32-bit processor and more than 4
1413 gigabytes of physical RAM.
1414
1415endchoice
1416
1417choice
6a108a14 1418 prompt "Memory split" if EXPERT
506f1d07
SR
1419 default VMSPLIT_3G
1420 depends on X86_32
a7f7f624 1421 help
506f1d07
SR
1422 Select the desired split between kernel and user memory.
1423
1424 If the address range available to the kernel is less than the
1425 physical memory installed, the remaining memory will be available
1426 as "high memory". Accessing high memory is a little more costly
1427 than low memory, as it needs to be mapped into the kernel first.
1428 Note that increasing the kernel address space limits the range
1429 available to user programs, making the address space there
1430 tighter. Selecting anything other than the default 3G/1G split
1431 will also likely make your kernel incompatible with binary-only
1432 kernel modules.
1433
1434 If you are not absolutely sure what you are doing, leave this
1435 option alone!
1436
1437 config VMSPLIT_3G
1438 bool "3G/1G user/kernel split"
1439 config VMSPLIT_3G_OPT
1440 depends on !X86_PAE
1441 bool "3G/1G user/kernel split (for full 1G low memory)"
1442 config VMSPLIT_2G
1443 bool "2G/2G user/kernel split"
1444 config VMSPLIT_2G_OPT
1445 depends on !X86_PAE
1446 bool "2G/2G user/kernel split (for full 2G low memory)"
1447 config VMSPLIT_1G
1448 bool "1G/3G user/kernel split"
1449endchoice
1450
1451config PAGE_OFFSET
1452 hex
1453 default 0xB0000000 if VMSPLIT_3G_OPT
1454 default 0x80000000 if VMSPLIT_2G
1455 default 0x78000000 if VMSPLIT_2G_OPT
1456 default 0x40000000 if VMSPLIT_1G
1457 default 0xC0000000
1458 depends on X86_32
1459
1460config HIGHMEM
3c2362e6 1461 def_bool y
506f1d07 1462 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1463
1464config X86_PAE
9ba16087 1465 bool "PAE (Physical Address Extension) Support"
506f1d07 1466 depends on X86_32 && !HIGHMEM4G
d4a451d5 1467 select PHYS_ADDR_T_64BIT
9d99c712 1468 select SWIOTLB
a7f7f624 1469 help
506f1d07
SR
1470 PAE is required for NX support, and furthermore enables
1471 larger swapspace support for non-overcommit purposes. It
1472 has the cost of more pagetable lookup overhead, and also
1473 consumes more pagetable space per process.
1474
77ef56e4
KS
1475config X86_5LEVEL
1476 bool "Enable 5-level page tables support"
18ec1eaf 1477 default y
eedb92ab 1478 select DYNAMIC_MEMORY_LAYOUT
162434e7 1479 select SPARSEMEM_VMEMMAP
77ef56e4 1480 depends on X86_64
a7f7f624 1481 help
77ef56e4
KS
1482 5-level paging enables access to larger address space:
1483 upto 128 PiB of virtual address space and 4 PiB of
1484 physical address space.
1485
1486 It will be supported by future Intel CPUs.
1487
6657fca0
KS
1488 A kernel with the option enabled can be booted on machines that
1489 support 4- or 5-level paging.
77ef56e4 1490
cb1aaebe 1491 See Documentation/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1492 information.
1493
1494 Say N if unsure.
1495
10971ab2 1496config X86_DIRECT_GBPAGES
e5008abe 1497 def_bool y
2e1da13f 1498 depends on X86_64
a7f7f624 1499 help
10971ab2
IM
1500 Certain kernel features effectively disable kernel
1501 linear 1 GB mappings (even if the CPU otherwise
1502 supports them), so don't confuse the user by printing
1503 that we have them enabled.
9e899816 1504
5c280cf6
TG
1505config X86_CPA_STATISTICS
1506 bool "Enable statistic for Change Page Attribute"
1507 depends on DEBUG_FS
a7f7f624 1508 help
b75baaf3 1509 Expose statistics about the Change Page Attribute mechanism, which
a943245a 1510 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1511 page mappings when mapping protections are changed.
1512
7744ccdb
TL
1513config AMD_MEM_ENCRYPT
1514 bool "AMD Secure Memory Encryption (SME) support"
1515 depends on X86_64 && CPU_SUP_AMD
82fef0ad 1516 select DMA_COHERENT_POOL
94d49eb3 1517 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1518 select ARCH_USE_MEMREMAP_PROT
9087c375 1519 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
597cfe48 1520 select INSTRUCTION_DECODER
22916417 1521 select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
a7f7f624 1522 help
7744ccdb
TL
1523 Say yes to enable support for the encryption of system memory.
1524 This requires an AMD processor that supports Secure Memory
1525 Encryption (SME).
1526
1527config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1528 bool "Activate AMD Secure Memory Encryption (SME) by default"
1529 default y
1530 depends on AMD_MEM_ENCRYPT
a7f7f624 1531 help
7744ccdb
TL
1532 Say yes to have system memory encrypted by default if running on
1533 an AMD processor that supports Secure Memory Encryption (SME).
1534
1535 If set to Y, then the encryption of system memory can be
1536 deactivated with the mem_encrypt=off command line option.
1537
1538 If set to N, then the encryption of system memory can be
1539 activated with the mem_encrypt=on command line option.
1540
506f1d07
SR
1541# Common NUMA Features
1542config NUMA
e133f6ea 1543 bool "NUMA Memory Allocation and Scheduler Support"
506f1d07 1544 depends on SMP
b5660ba7
PA
1545 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1546 default y if X86_BIGSMP
a7f7f624 1547 help
e133f6ea 1548 Enable NUMA (Non-Uniform Memory Access) support.
fd51b2d7 1549
506f1d07
SR
1550 The kernel will try to allocate memory used by a CPU on the
1551 local memory controller of the CPU and add some more
1552 NUMA awareness to the kernel.
1553
c280ea5e 1554 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1555 (or later), AMD Opteron, or EM64T NUMA.
1556
b5660ba7 1557 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1558 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1559
1560 Otherwise, you should say N.
506f1d07 1561
eec1d4fa 1562config AMD_NUMA
3c2362e6
HH
1563 def_bool y
1564 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1565 depends on X86_64 && NUMA && PCI
a7f7f624 1566 help
eec1d4fa
HR
1567 Enable AMD NUMA node topology detection. You should say Y here if
1568 you have a multi processor AMD system. This uses an old method to
1569 read the NUMA configuration directly from the builtin Northbridge
1570 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1571 which also takes priority if both are compiled in.
506f1d07
SR
1572
1573config X86_64_ACPI_NUMA
3c2362e6
HH
1574 def_bool y
1575 prompt "ACPI NUMA detection"
506f1d07
SR
1576 depends on X86_64 && NUMA && ACPI && PCI
1577 select ACPI_NUMA
a7f7f624 1578 help
506f1d07
SR
1579 Enable ACPI SRAT based node topology detection.
1580
1581config NUMA_EMU
1582 bool "NUMA emulation"
1b7e03ef 1583 depends on NUMA
a7f7f624 1584 help
506f1d07
SR
1585 Enable NUMA emulation. A flat machine will be split
1586 into virtual nodes when booted with "numa=fake=N", where N is the
1587 number of nodes. This is only useful for debugging.
1588
1589config NODES_SHIFT
d25e26b6 1590 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1591 range 1 10
1592 default "10" if MAXSMP
506f1d07 1593 default "6" if X86_64
506f1d07
SR
1594 default "3"
1595 depends on NEED_MULTIPLE_NODES
a7f7f624 1596 help
1184dc2f 1597 Specify the maximum number of NUMA Nodes available on the target
692105b8 1598 system. Increases memory reserved to accommodate various tables.
506f1d07 1599
506f1d07
SR
1600config ARCH_FLATMEM_ENABLE
1601 def_bool y
3b16651f 1602 depends on X86_32 && !NUMA
506f1d07 1603
506f1d07
SR
1604config ARCH_SPARSEMEM_ENABLE
1605 def_bool y
6ea30386 1606 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1607 select SPARSEMEM_STATIC if X86_32
1608 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1609
3b16651f 1610config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1611 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1612
506f1d07
SR
1613config ARCH_SELECT_MEMORY_MODEL
1614 def_bool y
b263295d 1615 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1616
1617config ARCH_MEMORY_PROBE
a0842b70 1618 bool "Enable sysfs memory/probe interface"
3120e25e 1619 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1620 help
1621 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1622 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1623 If you are unsure how to answer this question, answer N.
506f1d07 1624
3b16651f
TH
1625config ARCH_PROC_KCORE_TEXT
1626 def_bool y
1627 depends on X86_64 && PROC_KCORE
1628
a29815a3 1629config ILLEGAL_POINTER_VALUE
b03b016f
KK
1630 hex
1631 default 0 if X86_32
1632 default 0xdead000000000000 if X86_64
a29815a3 1633
7a67832c
DW
1634config X86_PMEM_LEGACY_DEVICE
1635 bool
1636
ec776ef6 1637config X86_PMEM_LEGACY
7a67832c 1638 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1639 depends on PHYS_ADDR_T_64BIT
1640 depends on BLK_DEV
7a67832c 1641 select X86_PMEM_LEGACY_DEVICE
7b27a862 1642 select NUMA_KEEP_MEMINFO if NUMA
9f53f9fa 1643 select LIBNVDIMM
ec776ef6
CH
1644 help
1645 Treat memory marked using the non-standard e820 type of 12 as used
1646 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1647 The kernel will offer these regions to the 'pmem' driver so
1648 they can be used for persistent storage.
1649
1650 Say Y if unsure.
1651
506f1d07
SR
1652config HIGHPTE
1653 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1654 depends on HIGHMEM
a7f7f624 1655 help
506f1d07
SR
1656 The VM uses one page table entry for each page of physical memory.
1657 For systems with a lot of RAM, this can be wasteful of precious
1658 low memory. Setting this option will put user-space page table
1659 entries in high memory.
1660
9f077871 1661config X86_CHECK_BIOS_CORRUPTION
8f9ca475 1662 bool "Check for low memory corruption"
a7f7f624 1663 help
8f9ca475
IM
1664 Periodically check for memory corruption in low memory, which
1665 is suspected to be caused by BIOS. Even when enabled in the
1666 configuration, it is disabled at runtime. Enable it by
1667 setting "memory_corruption_check=1" on the kernel command
1668 line. By default it scans the low 64k of memory every 60
1669 seconds; see the memory_corruption_check_size and
1670 memory_corruption_check_period parameters in
8c27ceff 1671 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1672
1673 When enabled with the default parameters, this option has
1674 almost no overhead, as it reserves a relatively small amount
1675 of memory and scans it infrequently. It both detects corruption
1676 and prevents it from affecting the running system.
1677
1678 It is, however, intended as a diagnostic tool; if repeatable
1679 BIOS-originated corruption always affects the same memory,
1680 you can use memmap= to prevent the kernel from using that
1681 memory.
9f077871 1682
c885df50 1683config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1684 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1685 depends on X86_CHECK_BIOS_CORRUPTION
1686 default y
a7f7f624 1687 help
8f9ca475
IM
1688 Set whether the default state of memory_corruption_check is
1689 on or off.
c885df50 1690
9ea77bdb 1691config X86_RESERVE_LOW
d0cd7425
PA
1692 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1693 default 64
1694 range 4 640
a7f7f624 1695 help
d0cd7425
PA
1696 Specify the amount of low memory to reserve for the BIOS.
1697
1698 The first page contains BIOS data structures that the kernel
1699 must not use, so that page must always be reserved.
1700
1701 By default we reserve the first 64K of physical RAM, as a
1702 number of BIOSes are known to corrupt that memory range
1703 during events such as suspend/resume or monitor cable
1704 insertion, so it must not be used by the kernel.
fc381519 1705
d0cd7425
PA
1706 You can set this to 4 if you are absolutely sure that you
1707 trust the BIOS to get all its memory reservations and usages
1708 right. If you know your BIOS have problems beyond the
1709 default 64K area, you can set this to 640 to avoid using the
1710 entire low memory range.
fc381519 1711
d0cd7425
PA
1712 If you have doubts about the BIOS (e.g. suspend/resume does
1713 not work or there's kernel crashes after certain hardware
1714 hotplug events) then you might want to enable
1715 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1716 typical corruption patterns.
fc381519 1717
d0cd7425 1718 Leave this to the default value of 64 if you are unsure.
fc381519 1719
506f1d07
SR
1720config MATH_EMULATION
1721 bool
a5b9e5a2 1722 depends on MODIFY_LDT_SYSCALL
87d6021b 1723 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
a7f7f624 1724 help
506f1d07
SR
1725 Linux can emulate a math coprocessor (used for floating point
1726 operations) if you don't have one. 486DX and Pentium processors have
1727 a math coprocessor built in, 486SX and 386 do not, unless you added
1728 a 487DX or 387, respectively. (The messages during boot time can
1729 give you some hints here ["man dmesg"].) Everyone needs either a
1730 coprocessor or this emulation.
1731
1732 If you don't have a math coprocessor, you need to say Y here; if you
1733 say Y here even though you have a coprocessor, the coprocessor will
1734 be used nevertheless. (This behavior can be changed with the kernel
1735 command line option "no387", which comes handy if your coprocessor
1736 is broken. Try "man bootparam" or see the documentation of your boot
1737 loader (lilo or loadlin) about how to pass options to the kernel at
1738 boot time.) This means that it is a good idea to say Y here if you
1739 intend to use this kernel on different machines.
1740
1741 More information about the internals of the Linux math coprocessor
1742 emulation can be found in <file:arch/x86/math-emu/README>.
1743
1744 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1745 kernel, it won't hurt.
1746
1747config MTRR
6fc108a0 1748 def_bool y
6a108a14 1749 prompt "MTRR (Memory Type Range Register) support" if EXPERT
a7f7f624 1750 help
506f1d07
SR
1751 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1752 the Memory Type Range Registers (MTRRs) may be used to control
1753 processor access to memory ranges. This is most useful if you have
1754 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1755 allows bus write transfers to be combined into a larger transfer
1756 before bursting over the PCI/AGP bus. This can increase performance
1757 of image write operations 2.5 times or more. Saying Y here creates a
1758 /proc/mtrr file which may be used to manipulate your processor's
1759 MTRRs. Typically the X server should use this.
1760
1761 This code has a reasonably generic interface so that similar
1762 control registers on other processors can be easily supported
1763 as well:
1764
1765 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1766 Registers (ARRs) which provide a similar functionality to MTRRs. For
1767 these, the ARRs are used to emulate the MTRRs.
1768 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1769 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1770 write-combining. All of these processors are supported by this code
1771 and it makes sense to say Y here if you have one of them.
1772
1773 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1774 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1775 can lead to all sorts of problems, so it's good to say Y here.
1776
1777 You can safely say Y even if your machine doesn't have MTRRs, you'll
1778 just add about 9 KB to your kernel.
1779
cb1aaebe 1780 See <file:Documentation/x86/mtrr.rst> for more information.
506f1d07 1781
95ffa243 1782config MTRR_SANITIZER
2ffb3501 1783 def_bool y
95ffa243
YL
1784 prompt "MTRR cleanup support"
1785 depends on MTRR
a7f7f624 1786 help
aba3728c
TG
1787 Convert MTRR layout from continuous to discrete, so X drivers can
1788 add writeback entries.
95ffa243 1789
aba3728c 1790 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1791 The largest mtrr entry size for a continuous block can be set with
aba3728c 1792 mtrr_chunk_size.
95ffa243 1793
2ffb3501 1794 If unsure, say Y.
95ffa243
YL
1795
1796config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1797 int "MTRR cleanup enable value (0-1)"
1798 range 0 1
1799 default "0"
95ffa243 1800 depends on MTRR_SANITIZER
a7f7f624 1801 help
f5098d62 1802 Enable mtrr cleanup default value
95ffa243 1803
12031a62
YL
1804config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1805 int "MTRR cleanup spare reg num (0-7)"
1806 range 0 7
1807 default "1"
1808 depends on MTRR_SANITIZER
a7f7f624 1809 help
12031a62 1810 mtrr cleanup spare entries default, it can be changed via
aba3728c 1811 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1812
2e5d9c85 1813config X86_PAT
6fc108a0 1814 def_bool y
6a108a14 1815 prompt "x86 PAT support" if EXPERT
2a8a2719 1816 depends on MTRR
a7f7f624 1817 help
2e5d9c85 1818 Use PAT attributes to setup page level cache control.
042b78e4 1819
2e5d9c85 1820 PATs are the modern equivalents of MTRRs and are much more
1821 flexible than MTRRs.
1822
1823 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1824 spontaneous reboots) or a non-working video driver.
2e5d9c85 1825
1826 If unsure, say Y.
1827
46cf98cd
VP
1828config ARCH_USES_PG_UNCACHED
1829 def_bool y
1830 depends on X86_PAT
1831
628c6246
PA
1832config ARCH_RANDOM
1833 def_bool y
1834 prompt "x86 architectural random number generator" if EXPERT
a7f7f624 1835 help
628c6246
PA
1836 Enable the x86 architectural RDRAND instruction
1837 (Intel Bull Mountain technology) to generate random numbers.
1838 If supported, this is a high bandwidth, cryptographically
1839 secure hardware random number generator.
1840
51ae4a2d
PA
1841config X86_SMAP
1842 def_bool y
1843 prompt "Supervisor Mode Access Prevention" if EXPERT
a7f7f624 1844 help
51ae4a2d
PA
1845 Supervisor Mode Access Prevention (SMAP) is a security
1846 feature in newer Intel processors. There is a small
1847 performance cost if this enabled and turned on; there is
1848 also a small increase in the kernel size if this is enabled.
1849
1850 If unsure, say Y.
1851
b971880f 1852config X86_UMIP
796ebc81 1853 def_bool y
b971880f 1854 prompt "User Mode Instruction Prevention" if EXPERT
a7f7f624 1855 help
b971880f
BM
1856 User Mode Instruction Prevention (UMIP) is a security feature in
1857 some x86 processors. If enabled, a general protection fault is
1858 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1859 executed in user mode. These instructions unnecessarily expose
1860 information about the hardware state.
796ebc81
RN
1861
1862 The vast majority of applications do not use these instructions.
1863 For the very few that do, software emulation is provided in
1864 specific cases in protected and virtual-8086 modes. Emulated
1865 results are dummy.
aa35f896 1866
35e97790 1867config X86_INTEL_MEMORY_PROTECTION_KEYS
38f3e775 1868 prompt "Memory Protection Keys"
35e97790 1869 def_bool y
284244a9 1870 # Note: only available in 64-bit mode
38f3e775 1871 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
52c8e601
IM
1872 select ARCH_USES_HIGH_VMA_FLAGS
1873 select ARCH_HAS_PKEYS
a7f7f624 1874 help
284244a9
DH
1875 Memory Protection Keys provides a mechanism for enforcing
1876 page-based protections, but without requiring modification of the
1877 page tables when an application changes protection domains.
1878
1eecbcdc 1879 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1880
1881 If unsure, say y.
35e97790 1882
db616173
MH
1883choice
1884 prompt "TSX enable mode"
1885 depends on CPU_SUP_INTEL
1886 default X86_INTEL_TSX_MODE_OFF
1887 help
1888 Intel's TSX (Transactional Synchronization Extensions) feature
1889 allows to optimize locking protocols through lock elision which
1890 can lead to a noticeable performance boost.
1891
1892 On the other hand it has been shown that TSX can be exploited
1893 to form side channel attacks (e.g. TAA) and chances are there
1894 will be more of those attacks discovered in the future.
1895
1896 Therefore TSX is not enabled by default (aka tsx=off). An admin
1897 might override this decision by tsx=on the command line parameter.
1898 Even with TSX enabled, the kernel will attempt to enable the best
1899 possible TAA mitigation setting depending on the microcode available
1900 for the particular machine.
1901
1902 This option allows to set the default tsx mode between tsx=on, =off
1903 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1904 details.
1905
1906 Say off if not sure, auto if TSX is in use but it should be used on safe
1907 platforms or on if TSX is in use and the security aspect of tsx is not
1908 relevant.
1909
1910config X86_INTEL_TSX_MODE_OFF
1911 bool "off"
1912 help
1913 TSX is disabled if possible - equals to tsx=off command line parameter.
1914
1915config X86_INTEL_TSX_MODE_ON
1916 bool "on"
1917 help
1918 TSX is always enabled on TSX capable HW - equals the tsx=on command
1919 line parameter.
1920
1921config X86_INTEL_TSX_MODE_AUTO
1922 bool "auto"
1923 help
1924 TSX is enabled on TSX capable HW that is believed to be safe against
1925 side channel attacks- equals the tsx=auto command line parameter.
1926endchoice
1927
e7e05452
SC
1928config X86_SGX
1929 bool "Software Guard eXtensions (SGX)"
1930 depends on X86_64 && CPU_SUP_INTEL
1931 depends on CRYPTO=y
1932 depends on CRYPTO_SHA256=y
1933 select SRCU
1934 select MMU_NOTIFIER
901ddbb9 1935 select NUMA_KEEP_MEMINFO if NUMA
e7e05452
SC
1936 help
1937 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1938 that can be used by applications to set aside private regions of code
1939 and data, referred to as enclaves. An enclave's private memory can
1940 only be accessed by code running within the enclave. Accesses from
1941 outside the enclave, including other enclaves, are disallowed by
1942 hardware.
1943
1944 If unsure, say N.
1945
506f1d07 1946config EFI
9ba16087 1947 bool "EFI runtime service support"
5b83683f 1948 depends on ACPI
f6ce5002 1949 select UCS2_STRING
022ee6c5 1950 select EFI_RUNTIME_WRAPPERS
a7f7f624 1951 help
8f9ca475
IM
1952 This enables the kernel to use EFI runtime services that are
1953 available (such as the EFI variable services).
506f1d07 1954
8f9ca475
IM
1955 This option is only useful on systems that have EFI firmware.
1956 In addition, you should use the latest ELILO loader available
1957 at <http://elilo.sourceforge.net> in order to take advantage
1958 of EFI runtime services. However, even with this option, the
1959 resultant kernel should continue to boot on existing non-EFI
1960 platforms.
506f1d07 1961
291f3632 1962config EFI_STUB
8f24f8c2
AB
1963 bool "EFI stub support"
1964 depends on EFI && !X86_USE_3DNOW
1965 depends on $(cc-option,-mabi=ms) || X86_32
1966 select RELOCATABLE
a7f7f624 1967 help
8f24f8c2 1968 This kernel feature allows a bzImage to be loaded directly
291f3632
MF
1969 by EFI firmware without the use of a bootloader.
1970
4f4cfa6c 1971 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 1972
7d453eee
MF
1973config EFI_MIXED
1974 bool "EFI mixed-mode support"
1975 depends on EFI_STUB && X86_64
a7f7f624 1976 help
7d453eee
MF
1977 Enabling this feature allows a 64-bit kernel to be booted
1978 on a 32-bit firmware, provided that your CPU supports 64-bit
1979 mode.
1980
1981 Note that it is not possible to boot a mixed-mode enabled
1982 kernel via the EFI boot stub - a bootloader that supports
1983 the EFI handover protocol must be used.
1984
1985 If unsure, say N.
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
a6b68076 2464config X86_APM_BOOT
6fc108a0 2465 def_bool y
282e5aab 2466 depends on APM
a6b68076 2467
e279b6c1
SR
2468menuconfig APM
2469 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2470 depends on X86_32 && PM_SLEEP
a7f7f624 2471 help
e279b6c1
SR
2472 APM is a BIOS specification for saving power using several different
2473 techniques. This is mostly useful for battery powered laptops with
2474 APM compliant BIOSes. If you say Y here, the system time will be
2475 reset after a RESUME operation, the /proc/apm device will provide
2476 battery status information, and user-space programs will receive
2477 notification of APM "events" (e.g. battery status change).
2478
2479 If you select "Y" here, you can disable actual use of the APM
2480 BIOS by passing the "apm=off" option to the kernel at boot time.
2481
2482 Note that the APM support is almost completely disabled for
2483 machines with more than one CPU.
2484
2485 In order to use APM, you will need supporting software. For location
151f4e2b 2486 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2487 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2488 <http://www.tldp.org/docs.html#howto>.
2489
2490 This driver does not spin down disk drives (see the hdparm(8)
2491 manpage ("man 8 hdparm") for that), and it doesn't turn off
2492 VESA-compliant "green" monitors.
2493
2494 This driver does not support the TI 4000M TravelMate and the ACER
2495 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2496 desktop machines also don't have compliant BIOSes, and this driver
2497 may cause those machines to panic during the boot phase.
2498
2499 Generally, if you don't have a battery in your machine, there isn't
2500 much point in using this driver and you should say N. If you get
2501 random kernel OOPSes or reboots that don't seem to be related to
2502 anything, try disabling/enabling this option (or disabling/enabling
2503 APM in your BIOS).
2504
2505 Some other things you should try when experiencing seemingly random,
2506 "weird" problems:
2507
2508 1) make sure that you have enough swap space and that it is
2509 enabled.
2510 2) pass the "no-hlt" option to the kernel
2511 3) switch on floating point emulation in the kernel and pass
2512 the "no387" option to the kernel
2513 4) pass the "floppy=nodma" option to the kernel
2514 5) pass the "mem=4M" option to the kernel (thereby disabling
2515 all but the first 4 MB of RAM)
2516 6) make sure that the CPU is not over clocked.
2517 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2518 8) disable the cache from your BIOS settings
2519 9) install a fan for the video card or exchange video RAM
2520 10) install a better fan for the CPU
2521 11) exchange RAM chips
2522 12) exchange the motherboard.
2523
2524 To compile this driver as a module, choose M here: the
2525 module will be called apm.
2526
2527if APM
2528
2529config APM_IGNORE_USER_SUSPEND
2530 bool "Ignore USER SUSPEND"
a7f7f624 2531 help
e279b6c1
SR
2532 This option will ignore USER SUSPEND requests. On machines with a
2533 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2534 series notebooks, it is necessary to say Y because of a BIOS bug.
2535
2536config APM_DO_ENABLE
2537 bool "Enable PM at boot time"
a7f7f624 2538 help
e279b6c1
SR
2539 Enable APM features at boot time. From page 36 of the APM BIOS
2540 specification: "When disabled, the APM BIOS does not automatically
2541 power manage devices, enter the Standby State, enter the Suspend
2542 State, or take power saving steps in response to CPU Idle calls."
2543 This driver will make CPU Idle calls when Linux is idle (unless this
2544 feature is turned off -- see "Do CPU IDLE calls", below). This
2545 should always save battery power, but more complicated APM features
2546 will be dependent on your BIOS implementation. You may need to turn
2547 this option off if your computer hangs at boot time when using APM
2548 support, or if it beeps continuously instead of suspending. Turn
2549 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2550 T400CDT. This is off by default since most machines do fine without
2551 this feature.
2552
2553config APM_CPU_IDLE
dd8af076 2554 depends on CPU_IDLE
e279b6c1 2555 bool "Make CPU Idle calls when idle"
a7f7f624 2556 help
e279b6c1
SR
2557 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2558 On some machines, this can activate improved power savings, such as
2559 a slowed CPU clock rate, when the machine is idle. These idle calls
2560 are made after the idle loop has run for some length of time (e.g.,
2561 333 mS). On some machines, this will cause a hang at boot time or
2562 whenever the CPU becomes idle. (On machines with more than one CPU,
2563 this option does nothing.)
2564
2565config APM_DISPLAY_BLANK
2566 bool "Enable console blanking using APM"
a7f7f624 2567 help
e279b6c1
SR
2568 Enable console blanking using the APM. Some laptops can use this to
2569 turn off the LCD backlight when the screen blanker of the Linux
2570 virtual console blanks the screen. Note that this is only used by
2571 the virtual console screen blanker, and won't turn off the backlight
2572 when using the X Window system. This also doesn't have anything to
2573 do with your VESA-compliant power-saving monitor. Further, this
2574 option doesn't work for all laptops -- it might not turn off your
2575 backlight at all, or it might print a lot of errors to the console,
2576 especially if you are using gpm.
2577
2578config APM_ALLOW_INTS
2579 bool "Allow interrupts during APM BIOS calls"
a7f7f624 2580 help
e279b6c1
SR
2581 Normally we disable external interrupts while we are making calls to
2582 the APM BIOS as a measure to lessen the effects of a badly behaving
2583 BIOS implementation. The BIOS should reenable interrupts if it
2584 needs to. Unfortunately, some BIOSes do not -- especially those in
2585 many of the newer IBM Thinkpads. If you experience hangs when you
2586 suspend, try setting this to Y. Otherwise, say N.
2587
e279b6c1
SR
2588endif # APM
2589
bb0a56ec 2590source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2591
2592source "drivers/cpuidle/Kconfig"
2593
27471fdb
AH
2594source "drivers/idle/Kconfig"
2595
e279b6c1
SR
2596endmenu
2597
2598
2599menu "Bus options (PCI etc.)"
2600
e279b6c1
SR
2601choice
2602 prompt "PCI access mode"
efefa6f6 2603 depends on X86_32 && PCI
e279b6c1 2604 default PCI_GOANY
a7f7f624 2605 help
e279b6c1
SR
2606 On PCI systems, the BIOS can be used to detect the PCI devices and
2607 determine their configuration. However, some old PCI motherboards
2608 have BIOS bugs and may crash if this is done. Also, some embedded
2609 PCI-based systems don't have any BIOS at all. Linux can also try to
2610 detect the PCI hardware directly without using the BIOS.
2611
2612 With this option, you can specify how Linux should detect the
2613 PCI devices. If you choose "BIOS", the BIOS will be used,
2614 if you choose "Direct", the BIOS won't be used, and if you
2615 choose "MMConfig", then PCI Express MMCONFIG will be used.
2616 If you choose "Any", the kernel will try MMCONFIG, then the
2617 direct access method and falls back to the BIOS if that doesn't
2618 work. If unsure, go with the default, which is "Any".
2619
2620config PCI_GOBIOS
2621 bool "BIOS"
2622
2623config PCI_GOMMCONFIG
2624 bool "MMConfig"
2625
2626config PCI_GODIRECT
2627 bool "Direct"
2628
3ef0e1f8 2629config PCI_GOOLPC
76fb6570 2630 bool "OLPC XO-1"
3ef0e1f8
AS
2631 depends on OLPC
2632
2bdd1b03
AS
2633config PCI_GOANY
2634 bool "Any"
2635
e279b6c1
SR
2636endchoice
2637
2638config PCI_BIOS
3c2362e6 2639 def_bool y
efefa6f6 2640 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2641
2642# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2643config PCI_DIRECT
3c2362e6 2644 def_bool y
0aba496f 2645 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2646
2647config PCI_MMCONFIG
b45c9f36
JK
2648 bool "Support mmconfig PCI config space access" if X86_64
2649 default y
4590d98f 2650 depends on PCI && (ACPI || JAILHOUSE_GUEST)
b45c9f36 2651 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2652
3ef0e1f8 2653config PCI_OLPC
2bdd1b03
AS
2654 def_bool y
2655 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2656
b5401a96
AN
2657config PCI_XEN
2658 def_bool y
2659 depends on PCI && XEN
2660 select SWIOTLB_XEN
2661
8364e1f8
JK
2662config MMCONF_FAM10H
2663 def_bool y
2664 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2665
3f6ea84a 2666config PCI_CNB20LE_QUIRK
6a108a14 2667 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2668 depends on PCI
3f6ea84a
IS
2669 help
2670 Read the PCI windows out of the CNB20LE host bridge. This allows
2671 PCI hotplug to work on systems with the CNB20LE chipset which do
2672 not have ACPI.
2673
64a5fed6
BH
2674 There's no public spec for this chipset, and this functionality
2675 is known to be incomplete.
2676
2677 You should say N unless you know you need this.
2678
3a495511 2679config ISA_BUS
17a2a129 2680 bool "ISA bus support on modern systems" if EXPERT
3a495511 2681 help
17a2a129
WBG
2682 Expose ISA bus device drivers and options available for selection and
2683 configuration. Enable this option if your target machine has an ISA
2684 bus. ISA is an older system, displaced by PCI and newer bus
2685 architectures -- if your target machine is modern, it probably does
2686 not have an ISA bus.
3a495511
WBG
2687
2688 If unsure, say N.
2689
1c00f016 2690# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2691config ISA_DMA_API
1c00f016
DR
2692 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2693 default y
2694 help
2695 Enables ISA-style DMA support for devices requiring such controllers.
2696 If unsure, say Y.
e279b6c1 2697
51e68d05
LT
2698if X86_32
2699
e279b6c1
SR
2700config ISA
2701 bool "ISA support"
a7f7f624 2702 help
e279b6c1
SR
2703 Find out whether you have ISA slots on your motherboard. ISA is the
2704 name of a bus system, i.e. the way the CPU talks to the other stuff
2705 inside your box. Other bus systems are PCI, EISA, MicroChannel
2706 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2707 newer boards don't support it. If you have ISA, say Y, otherwise N.
2708
e279b6c1
SR
2709config SCx200
2710 tristate "NatSemi SCx200 support"
a7f7f624 2711 help
e279b6c1
SR
2712 This provides basic support for National Semiconductor's
2713 (now AMD's) Geode processors. The driver probes for the
2714 PCI-IDs of several on-chip devices, so its a good dependency
2715 for other scx200_* drivers.
2716
2717 If compiled as a module, the driver is named scx200.
2718
2719config SCx200HR_TIMER
2720 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2721 depends on SCx200
e279b6c1 2722 default y
a7f7f624 2723 help
e279b6c1
SR
2724 This driver provides a clocksource built upon the on-chip
2725 27MHz high-resolution timer. Its also a workaround for
2726 NSC Geode SC-1100's buggy TSC, which loses time when the
2727 processor goes idle (as is done by the scheduler). The
2728 other workaround is idle=poll boot option.
2729
3ef0e1f8
AS
2730config OLPC
2731 bool "One Laptop Per Child support"
54008979 2732 depends on !X86_PAE
3c554946 2733 select GPIOLIB
dc3119e7 2734 select OF
45bb1674 2735 select OF_PROMTREE
b4e51854 2736 select IRQ_DOMAIN
0c3d931b 2737 select OLPC_EC
a7f7f624 2738 help
3ef0e1f8
AS
2739 Add support for detecting the unique features of the OLPC
2740 XO hardware.
2741
a3128588
DD
2742config OLPC_XO1_PM
2743 bool "OLPC XO-1 Power Management"
fa112cf1 2744 depends on OLPC && MFD_CS5535=y && PM_SLEEP
a7f7f624 2745 help
97c4cb71 2746 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2747
cfee9597
DD
2748config OLPC_XO1_RTC
2749 bool "OLPC XO-1 Real Time Clock"
2750 depends on OLPC_XO1_PM && RTC_DRV_CMOS
a7f7f624 2751 help
cfee9597
DD
2752 Add support for the XO-1 real time clock, which can be used as a
2753 programmable wakeup source.
2754
7feda8e9
DD
2755config OLPC_XO1_SCI
2756 bool "OLPC XO-1 SCI extras"
92e830f2 2757 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2758 depends on INPUT=y
d8d01a63 2759 select POWER_SUPPLY
a7f7f624 2760 help
7feda8e9 2761 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2762 - EC-driven system wakeups
7feda8e9 2763 - Power button
7bc74b3d 2764 - Ebook switch
2cf2baea 2765 - Lid switch
e1040ac6
DD
2766 - AC adapter status updates
2767 - Battery status updates
7feda8e9 2768
a0f30f59
DD
2769config OLPC_XO15_SCI
2770 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2771 depends on OLPC && ACPI
2772 select POWER_SUPPLY
a7f7f624 2773 help
a0f30f59
DD
2774 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2775 - EC-driven system wakeups
2776 - AC adapter status updates
2777 - Battery status updates
bf1ebf00 2778
d4f3e350
EW
2779config ALIX
2780 bool "PCEngines ALIX System Support (LED setup)"
2781 select GPIOLIB
a7f7f624 2782 help
d4f3e350
EW
2783 This option enables system support for the PCEngines ALIX.
2784 At present this just sets up LEDs for GPIO control on
2785 ALIX2/3/6 boards. However, other system specific setup should
2786 get added here.
2787
2788 Note: You must still enable the drivers for GPIO and LED support
2789 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2790
2791 Note: You have to set alix.force=1 for boards with Award BIOS.
2792
da4e3302
PP
2793config NET5501
2794 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2795 select GPIOLIB
a7f7f624 2796 help
da4e3302
PP
2797 This option enables system support for the Soekris Engineering net5501.
2798
3197059a
PP
2799config GEOS
2800 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2801 select GPIOLIB
2802 depends on DMI
a7f7f624 2803 help
3197059a
PP
2804 This option enables system support for the Traverse Technologies GEOS.
2805
7d029125
VD
2806config TS5500
2807 bool "Technologic Systems TS-5500 platform support"
2808 depends on MELAN
2809 select CHECK_SIGNATURE
2810 select NEW_LEDS
2811 select LEDS_CLASS
a7f7f624 2812 help
7d029125
VD
2813 This option enables system support for the Technologic Systems TS-5500.
2814
bc0120fd
SR
2815endif # X86_32
2816
23ac4ae8 2817config AMD_NB
e279b6c1 2818 def_bool y
0e152cd7 2819 depends on CPU_SUP_AMD && PCI
e279b6c1 2820
e3263ab3
DH
2821config X86_SYSFB
2822 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2823 help
2824 Firmwares often provide initial graphics framebuffers so the BIOS,
2825 bootloader or kernel can show basic video-output during boot for
2826 user-guidance and debugging. Historically, x86 used the VESA BIOS
2827 Extensions and EFI-framebuffers for this, which are mostly limited
2828 to x86.
2829 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2830 framebuffers so the new generic system-framebuffer drivers can be
2831 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2832 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DH
2833 drivers like efifb, vesafb and uvesafb can pick it up.
2834 If this option is not selected, all system framebuffers are always
2835 marked as fallback platform framebuffers as usual.
2836
2837 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2838 not be able to pick up generic system framebuffers if this option
2839 is selected. You are highly encouraged to enable simplefb as
2840 replacement if you select this option. simplefb can correctly deal
2841 with generic system framebuffers. But you should still keep vesafb
2842 and others enabled as fallback if a system framebuffer is
2843 incompatible with simplefb.
2844
2845 If unsure, say Y.
2846
e279b6c1
SR
2847endmenu
2848
2849
1572497c 2850menu "Binary Emulations"
e279b6c1
SR
2851
2852config IA32_EMULATION
2853 bool "IA32 Emulation"
2854 depends on X86_64
39f88911 2855 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2856 select BINFMT_ELF
39f88911 2857 select COMPAT_OLD_SIGACTION
a7f7f624 2858 help
5fd92e65
L
2859 Include code to run legacy 32-bit programs under a
2860 64-bit kernel. You should likely turn this on, unless you're
2861 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2862
2863config IA32_AOUT
8f9ca475
IM
2864 tristate "IA32 a.out support"
2865 depends on IA32_EMULATION
eac61655 2866 depends on BROKEN
a7f7f624 2867 help
8f9ca475 2868 Support old a.out binaries in the 32bit emulation.
e279b6c1 2869
0bf62763 2870config X86_X32
6ea30386 2871 bool "x32 ABI for 64-bit mode"
9b54050b 2872 depends on X86_64
a7f7f624 2873 help
5fd92e65
L
2874 Include code to run binaries for the x32 native 32-bit ABI
2875 for 64-bit processors. An x32 process gets access to the
2876 full 64-bit register file and wide data path while leaving
2877 pointers at 32 bits for smaller memory footprint.
2878
2879 You will need a recent binutils (2.22 or later) with
2880 elf32_x86_64 support enabled to compile a kernel with this
2881 option set.
2882
953fee1d
IM
2883config COMPAT_32
2884 def_bool y
2885 depends on IA32_EMULATION || X86_32
2886 select HAVE_UID16
2887 select OLD_SIGSUSPEND3
2888
e279b6c1 2889config COMPAT
3c2362e6 2890 def_bool y
0bf62763 2891 depends on IA32_EMULATION || X86_X32
e279b6c1 2892
3120e25e 2893if COMPAT
e279b6c1 2894config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2895 def_bool y
e279b6c1
SR
2896
2897config SYSVIPC_COMPAT
3c2362e6 2898 def_bool y
3120e25e 2899 depends on SYSVIPC
3120e25e 2900endif
ee009e4a 2901
e279b6c1
SR
2902endmenu
2903
2904
e5beae16
KP
2905config HAVE_ATOMIC_IOMAP
2906 def_bool y
2907 depends on X86_32
2908
e279b6c1
SR
2909source "drivers/firmware/Kconfig"
2910
edf88417 2911source "arch/x86/kvm/Kconfig"
5e8ebd84
JD
2912
2913source "arch/x86/Kconfig.assembler"