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arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
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b2441318 1# SPDX-License-Identifier: GPL-2.0
daa93fab
SR
2# Select 32 or 64 bit
3config 64BIT
104daea1
MY
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
a7f7f624 6 help
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SR
7 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
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JB
11 def_bool y
12 depends on !64BIT
341c787e
IM
13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
157e118b 17 select GENERIC_VDSO_32
117ed454 18 select HAVE_DEBUG_STACKOVERFLOW
157e118b 19 select KMAP_LOCAL
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IM
20 select MODULES_USE_ELF_REL
21 select OLD_SIGACTION
2ca408d9 22 select ARCH_SPLIT_ARG64
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SR
23
24config X86_64
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JB
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
0bff0aae 30 select ARCH_SUPPORTS_PER_VMA_LOCK
d94e0685
IM
31 select ARCH_USE_CMPXCHG_LOCKREF
32 select HAVE_ARCH_SOFT_DIRTY
33 select MODULES_USE_ELF_RELA
f616ab59 34 select NEED_DMA_MAP_STATE
09230cbc 35 select SWIOTLB
7facdc42 36 select ARCH_HAS_ELFCORE_COMPAT
63703f37 37 select ZONE_DMA32
1032c0ba 38
518049d9
SRV
39config FORCE_DYNAMIC_FTRACE
40 def_bool y
41 depends on X86_32
42 depends on FUNCTION_TRACER
43 select DYNAMIC_FTRACE
44 help
758cd94a
JH
45 We keep the static function tracing (!DYNAMIC_FTRACE) around
46 in order to test the non static function tracing in the
47 generic code, as other architectures still use it. But we
48 only need to keep it around for x86_64. No need to keep it
49 for x86_32. For x86_32, force DYNAMIC_FTRACE.
d94e0685
IM
50#
51# Arch settings
52#
53# ( Note that options that are marked 'if X86_64' could in principle be
54# ported to 32-bit as well. )
55#
8d5fffb9 56config X86
3c2362e6 57 def_bool y
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IM
58 #
59 # Note: keep this list sorted alphabetically
60 #
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IM
61 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
62 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 63 select ARCH_32BIT_OFF_T if X86_32
2a21ad57 64 select ARCH_CLOCKSOURCE_INIT
1f6d3a8f 65 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
1e866974 66 select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
5c11f00b 67 select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
91024b3c 68 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
cebc774f 69 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
1e866974 70 select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
c763ea26 71 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
c2280be8 72 select ARCH_HAS_CACHE_LINE_SIZE
1156b441 73 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
2792d84e 74 select ARCH_HAS_CURRENT_STACK_POINTER
fa5b6ec9 75 select ARCH_HAS_DEBUG_VIRTUAL
399145f9 76 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
21266be9 77 select ARCH_HAS_DEVMEM_IS_ALLOWED
b1a57bbf 78 select ARCH_HAS_EARLY_DEBUG if KGDB
6471b825 79 select ARCH_HAS_ELF_RANDOMIZE
72d93104 80 select ARCH_HAS_FAST_MULTIPLIER
6974f0c4 81 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 82 select ARCH_HAS_GCOV_PROFILE_ALL
bece04b5 83 select ARCH_HAS_KCOV if X86_64
0c9c1d56 84 select ARCH_HAS_MEM_ENCRYPT
10bcc80e 85 select ARCH_HAS_MEMBARRIER_SYNC_CORE
49f88c70 86 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
0ebeea8c 87 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
c763ea26 88 select ARCH_HAS_PMEM_API if X86_64
17596731 89 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 90 select ARCH_HAS_PTE_SPECIAL
eed9a328 91 select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2
0aed55af 92 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
ec6347bb 93 select ARCH_HAS_COPY_MC if X86_64
d2852a22 94 select ARCH_HAS_SET_MEMORY
d253ca0c 95 select ARCH_HAS_SET_DIRECT_MAP
ad21fc4f
LA
96 select ARCH_HAS_STRICT_KERNEL_RWX
97 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 98 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
25c619e5 99 select ARCH_HAS_SYSCALL_WRAPPER
c6d30853 100 select ARCH_HAS_UBSAN_SANITIZE_ALL
7e01ccb4 101 select ARCH_HAS_DEBUG_WX
63703f37 102 select ARCH_HAS_ZONE_DMA_SET if EXPERT
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IM
103 select ARCH_HAVE_NMI_SAFE_CMPXCHG
104 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 105 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 106 select ARCH_MIGHT_HAVE_PC_SERIO
3599fe12 107 select ARCH_STACKWALK
2c870e61 108 select ARCH_SUPPORTS_ACPI
6471b825 109 select ARCH_SUPPORTS_ATOMIC_RMW
5d6ad668 110 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
d283d422 111 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64
6471b825 112 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
14df3267 113 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
3c516f89
ST
114 select ARCH_SUPPORTS_CFI_CLANG if X86_64
115 select ARCH_USES_CFI_TRAPS if X86_64 && CFI_CLANG
583bfd48
NC
116 select ARCH_SUPPORTS_LTO_CLANG
117 select ARCH_SUPPORTS_LTO_CLANG_THIN
6471b825 118 select ARCH_USE_BUILTIN_BSWAP
dce44566 119 select ARCH_USE_MEMTEST
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IM
120 select ARCH_USE_QUEUED_RWLOCKS
121 select ARCH_USE_QUEUED_SPINLOCKS
2ce0d7f9 122 select ARCH_USE_SYM_ANNOTATIONS
ce4a4e56 123 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
81c22041 124 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
c763ea26 125 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
51c2ee6d 126 select ARCH_WANTS_NO_INSTR
07431506 127 select ARCH_WANT_GENERAL_HUGETLB
3876d4a3 128 select ARCH_WANT_HUGE_PMD_SHARE
59612b24 129 select ARCH_WANT_LD_ORPHAN_WARN
0b376f1e 130 select ARCH_WANT_OPTIMIZE_VMEMMAP if X86_64
38d8b4e6 131 select ARCH_WANTS_THP_SWAP if X86_64
b5f06f64 132 select ARCH_HAS_PARANOID_L1D_FLUSH
10916706 133 select BUILDTIME_TABLE_SORT
6471b825 134 select CLKEVT_I8253
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IM
135 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
136 select CLOCKSOURCE_WATCHDOG
7cf8f44a
AP
137 # Word-size accesses may read uninitialized data past the trailing \0
138 # in strings and cause false KMSAN reports.
139 select DCACHE_WORD_ACCESS if !KMSAN
3aac3ebe 140 select DYNAMIC_SIGFRAME
45471cd9
LT
141 select EDAC_ATOMIC_SCRUB
142 select EDAC_SUPPORT
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IM
143 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
144 select GENERIC_CLOCKEVENTS_MIN_ADJUST
145 select GENERIC_CMOS_UPDATE
146 select GENERIC_CPU_AUTOPROBE
61dc0f55 147 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 148 select GENERIC_EARLY_IOREMAP
27d6b4d1 149 select GENERIC_ENTRY
6471b825 150 select GENERIC_IOMAP
c7d6c9dd 151 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 152 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 153 select GENERIC_IRQ_MIGRATION if SMP
6471b825 154 select GENERIC_IRQ_PROBE
c201c917 155 select GENERIC_IRQ_RESERVATION_MODE
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IM
156 select GENERIC_IRQ_SHOW
157 select GENERIC_PENDING_IRQ if SMP
2ae27137 158 select GENERIC_PTDUMP
6471b825 159 select GENERIC_SMP_IDLE_THREAD
6471b825 160 select GENERIC_TIME_VSYSCALL
7ac87074 161 select GENERIC_GETTIMEOFDAY
550a77a7 162 select GENERIC_VDSO_TIME_NS
6ca297d4 163 select GUP_GET_PXX_LOW_HIGH if X86_PAE
17e5888e 164 select HARDIRQS_SW_RESEND
7edaeb68 165 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
fcbfe812 166 select HAS_IOPORT
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IM
167 select HAVE_ACPI_APEI if ACPI
168 select HAVE_ACPI_APEI_NMI if ACPI
169 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
170 select HAVE_ARCH_AUDITSYSCALL
171 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
eed1fcee 172 select HAVE_ARCH_HUGE_VMALLOC if X86_64
6471b825 173 select HAVE_ARCH_JUMP_LABEL
b34006c4 174 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 175 select HAVE_ARCH_KASAN if X86_64
0609ae01 176 select HAVE_ARCH_KASAN_VMALLOC if X86_64
1dc0da6e 177 select HAVE_ARCH_KFENCE
4ca8cc8d 178 select HAVE_ARCH_KMSAN if X86_64
6471b825 179 select HAVE_ARCH_KGDB
9e08f57d
DC
180 select HAVE_ARCH_MMAP_RND_BITS if MMU
181 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 182 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 183 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 184 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 185 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 186 select HAVE_ARCH_STACKLEAK
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IM
187 select HAVE_ARCH_TRACEHOOK
188 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 189 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
b64d8d1e 190 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
7677f7fd 191 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD
e37e43a4 192 select HAVE_ARCH_VMAP_STACK if X86_64
fe950f60 193 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
c763ea26 194 select HAVE_ARCH_WITHIN_STACK_FRAMES
2ff2b7ec 195 select HAVE_ASM_MODVERSIONS
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IM
196 select HAVE_CMPXCHG_DOUBLE
197 select HAVE_CMPXCHG_LOCAL
24a9c541
FW
198 select HAVE_CONTEXT_TRACKING_USER if X86_64
199 select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER
cf4db259 200 select HAVE_C_RECORDMCOUNT
03f16cd0 201 select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL
280981d6 202 select HAVE_OBJTOOL_NOP_MCOUNT if HAVE_OBJTOOL_MCOUNT
4ed308c4 203 select HAVE_BUILDTIME_MCOUNT_SORT
6471b825 204 select HAVE_DEBUG_KMEMLEAK
6471b825 205 select HAVE_DMA_CONTIGUOUS
677aa9f7 206 select HAVE_DYNAMIC_FTRACE
06aeaaea 207 select HAVE_DYNAMIC_FTRACE_WITH_REGS
02a474ca 208 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
562955fe 209 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
c316eb44 210 select HAVE_SAMPLE_FTRACE_DIRECT if X86_64
503e4510 211 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64
03f5781b 212 select HAVE_EBPF_JIT
58340a07 213 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 214 select HAVE_EISA
5f56a5df 215 select HAVE_EXIT_THREAD
67a929e0 216 select HAVE_FAST_GUP
644e0e8d 217 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 218 select HAVE_FTRACE_MCOUNT_RECORD
4a30e4c9 219 select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
6471b825 220 select HAVE_FUNCTION_TRACER
6b90bd4b 221 select HAVE_GCC_PLUGINS
6471b825 222 select HAVE_HW_BREAKPOINT
6471b825 223 select HAVE_IOREMAP_PROT
624db9ea 224 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
6471b825 225 select HAVE_IRQ_TIME_ACCOUNTING
4ab7674f 226 select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL
2e9f3bdd 227 select HAVE_KERNEL_BZIP2
6471b825
IM
228 select HAVE_KERNEL_GZIP
229 select HAVE_KERNEL_LZ4
2e9f3bdd 230 select HAVE_KERNEL_LZMA
13510997 231 select HAVE_KERNEL_LZO
6471b825 232 select HAVE_KERNEL_XZ
fb46d057 233 select HAVE_KERNEL_ZSTD
6471b825
IM
234 select HAVE_KPROBES
235 select HAVE_KPROBES_ON_FTRACE
540adea3 236 select HAVE_FUNCTION_ERROR_INJECTION
6471b825 237 select HAVE_KRETPROBES
f3a112c0 238 select HAVE_RETHOOK
6471b825
IM
239 select HAVE_KVM
240 select HAVE_LIVEPATCH if X86_64
0102752e 241 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 242 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 243 select HAVE_MOVE_PMD
be37c98d 244 select HAVE_MOVE_PUD
22102f45 245 select HAVE_NOINSTR_HACK if HAVE_OBJTOOL
42a0bb3f 246 select HAVE_NMI
489e355b 247 select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL
03f16cd0 248 select HAVE_OBJTOOL if X86_64
6471b825
IM
249 select HAVE_OPTPROBES
250 select HAVE_PCSPKR_PLATFORM
251 select HAVE_PERF_EVENTS
c01d4323 252 select HAVE_PERF_EVENTS_NMI
92e5aae4 253 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 254 select HAVE_PCI
c5e63197 255 select HAVE_PERF_REGS
c5ebcedb 256 select HAVE_PERF_USER_STACK_DUMP
03f16cd0 257 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
1e9fdf21 258 select MMU_GATHER_MERGE_VMAS
00998085 259 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
6471b825 260 select HAVE_REGS_AND_STACK_ACCESS_API
03f16cd0 261 select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION
3c88ee19 262 select HAVE_FUNCTION_ARG_ACCESS_API
7ecd19cf 263 select HAVE_SETUP_PER_CPU_AREA
cd1a41ce 264 select HAVE_SOFTIRQ_ON_OWN_STACK
d148eac0 265 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
03f16cd0 266 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL
e6d6c071 267 select HAVE_STATIC_CALL
03f16cd0 268 select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL
99cf983c 269 select HAVE_PREEMPT_DYNAMIC_CALL
d6761b8f 270 select HAVE_RSEQ
09498135 271 select HAVE_RUST if X86_64
6471b825 272 select HAVE_SYSCALL_TRACEPOINTS
5f3da8c0 273 select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL
6471b825 274 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 275 select HAVE_USER_RETURN_NOTIFIER
7ac87074 276 select HAVE_GENERIC_VDSO
05736e4a 277 select HOTPLUG_SMT if SMP
c0185808 278 select IRQ_FORCED_THREADING
7ecd19cf
KW
279 select NEED_PER_CPU_EMBED_FIRST_CHUNK
280 select NEED_PER_CPU_PAGE_FIRST_CHUNK
86596f0a 281 select NEED_SG_DMA_LENGTH
2eac9c2d 282 select PCI_DOMAINS if PCI
625210cf 283 select PCI_LOCKLESS_CONFIG if PCI
6471b825 284 select PERF_EVENTS
3195ef59 285 select RTC_LIB
d6faca40 286 select RTC_MC146818_LIB
6471b825 287 select SPARSE_IRQ
6471b825 288 select SYSCTL_EXCEPTION_TRACE
15f4eae7 289 select THREAD_INFO_IN_TASK
4aae683f 290 select TRACE_IRQFLAGS_SUPPORT
4510bffb 291 select TRACE_IRQFLAGS_NMI_SUPPORT
6471b825 292 select USER_STACKTRACE_SUPPORT
3b02a051 293 select HAVE_ARCH_KCSAN if X86_64
6471b825 294 select X86_FEATURE_NAMES if PROC_FS
0c608dad 295 select PROC_PID_ARCH_STATUS if PROC_FS
50468e43 296 select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX
d49a0626
PZ
297 select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16
298 select FUNCTION_ALIGNMENT_4B
9e2b4be3 299 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
ceea991a 300 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
7d8330a5 301
ba7e4d13 302config INSTRUCTION_DECODER
3120e25e
JB
303 def_bool y
304 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 305
51b26ada
LT
306config OUTPUT_FORMAT
307 string
308 default "elf32-i386" if X86_32
309 default "elf64-x86-64" if X86_64
310
8d5fffb9 311config LOCKDEP_SUPPORT
3c2362e6 312 def_bool y
8d5fffb9
SR
313
314config STACKTRACE_SUPPORT
3c2362e6 315 def_bool y
8d5fffb9 316
8d5fffb9 317config MMU
3c2362e6 318 def_bool y
8d5fffb9 319
9e08f57d
DC
320config ARCH_MMAP_RND_BITS_MIN
321 default 28 if 64BIT
322 default 8
323
324config ARCH_MMAP_RND_BITS_MAX
325 default 32 if 64BIT
326 default 16
327
328config ARCH_MMAP_RND_COMPAT_BITS_MIN
329 default 8
330
331config ARCH_MMAP_RND_COMPAT_BITS_MAX
332 default 16
333
8d5fffb9
SR
334config SBUS
335 bool
336
337config GENERIC_ISA_DMA
3120e25e
JB
338 def_bool y
339 depends on ISA_DMA_API
8d5fffb9 340
d911c67e
AP
341config GENERIC_CSUM
342 bool
343 default y if KMSAN || KASAN
344
8d5fffb9 345config GENERIC_BUG
3c2362e6 346 def_bool y
8d5fffb9 347 depends on BUG
b93a531e
JB
348 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
349
350config GENERIC_BUG_RELATIVE_POINTERS
351 bool
8d5fffb9 352
8d5fffb9 353config ARCH_MAY_HAVE_PC_FDC
3120e25e
JB
354 def_bool y
355 depends on ISA_DMA_API
8d5fffb9 356
1032c0ba
SR
357config GENERIC_CALIBRATE_DELAY
358 def_bool y
359
9a0b8415 360config ARCH_HAS_CPU_RELAX
361 def_bool y
362
801e4062
JB
363config ARCH_HIBERNATION_POSSIBLE
364 def_bool y
801e4062 365
f4cb5700
JB
366config ARCH_SUSPEND_POSSIBLE
367 def_bool y
f4cb5700 368
8d5fffb9 369config AUDIT_ARCH
e0fd24a3 370 def_bool y if X86_64
8d5fffb9 371
d6f2d75a
AR
372config KASAN_SHADOW_OFFSET
373 hex
374 depends on KASAN
375 default 0xdffffc0000000000
376
69575d38
SW
377config HAVE_INTEL_TXT
378 def_bool y
6ea30386 379 depends on INTEL_IOMMU && ACPI
69575d38 380
6b0c3d44
SR
381config X86_32_SMP
382 def_bool y
383 depends on X86_32 && SMP
384
385config X86_64_SMP
386 def_bool y
387 depends on X86_64 && SMP
388
2b144498
SD
389config ARCH_SUPPORTS_UPROBES
390 def_bool y
391
d20642f0
RH
392config FIX_EARLYCON_MEM
393 def_bool y
394
94d49eb3
KS
395config DYNAMIC_PHYSICAL_MASK
396 bool
397
98233368
KS
398config PGTABLE_LEVELS
399 int
77ef56e4 400 default 5 if X86_5LEVEL
98233368
KS
401 default 4 if X86_64
402 default 3 if X86_PAE
403 default 2
404
2a61f474
MY
405config CC_HAS_SANE_STACKPROTECTOR
406 bool
1b866781
NC
407 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
408 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
2a61f474 409 help
758cd94a
JH
410 We have to make sure stack protector is unconditionally disabled if
411 the compiler produces broken code or if it does not let us control
412 the segment on 32-bit kernels.
2a61f474 413
506f1d07
SR
414menu "Processor type and features"
415
506f1d07
SR
416config SMP
417 bool "Symmetric multi-processing support"
a7f7f624 418 help
506f1d07 419 This enables support for systems with more than one CPU. If you have
4a474157
RG
420 a system with only one CPU, say N. If you have a system with more
421 than one CPU, say Y.
506f1d07 422
4a474157 423 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
424 machines, but will use only one CPU of a multiprocessor machine. If
425 you say Y here, the kernel will run on many, but not all,
4a474157 426 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
427 will run faster if you say N here.
428
429 Note that if you say Y here and choose architecture "586" or
430 "Pentium" under "Processor family", the kernel will not work on 486
431 architectures. Similarly, multiprocessor kernels for the "PPro"
432 architecture may not work on all Pentium based boards.
433
434 People using multiprocessor machines who say Y here should also say
435 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
436 Management" code will be disabled if you say Y here.
437
ff61f079 438 See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
4f4cfa6c 439 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
506f1d07
SR
440 <http://www.tldp.org/docs.html#howto>.
441
442 If you don't know what to do here, say N.
443
9def39be
JT
444config X86_FEATURE_NAMES
445 bool "Processor feature human-readable names" if EMBEDDED
446 default y
a7f7f624 447 help
9def39be
JT
448 This option compiles in a table of x86 feature bits and corresponding
449 names. This is required to support /proc/cpuinfo and a few kernel
450 messages. You can disable this to save space, at the expense of
451 making those few kernel messages show numeric feature bits instead.
452
453 If in doubt, say Y.
454
06cd9a7d
YL
455config X86_X2APIC
456 bool "Support x2apic"
19e3d60d 457 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
a7f7f624 458 help
06cd9a7d
YL
459 This enables x2apic support on CPUs that have this feature.
460
461 This allows 32-bit apic IDs (so it can support very large systems),
462 and accesses the local apic via MSRs not via mmio.
463
b8d1d163
DS
464 Some Intel systems circa 2022 and later are locked into x2APIC mode
465 and can not fall back to the legacy APIC modes if SGX or TDX are
e3998434
MJ
466 enabled in the BIOS. They will boot with very reduced functionality
467 without enabling this option.
b8d1d163 468
06cd9a7d
YL
469 If you don't know what to do here, say N.
470
6695c85b 471config X86_MPPARSE
4590d98f 472 bool "Enable MPS table" if ACPI
7a527688 473 default y
5ab74722 474 depends on X86_LOCAL_APIC
a7f7f624 475 help
6695c85b
YL
476 For old smp systems that do not have proper acpi support. Newer systems
477 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 478
ddd70cf9 479config GOLDFISH
b03b016f
KK
480 def_bool y
481 depends on X86_GOLDFISH
ddd70cf9 482
e6d42931
JW
483config X86_CPU_RESCTRL
484 bool "x86 CPU resource control support"
6fe07ce3 485 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 486 select KERNFS
e79f15a4 487 select PROC_CPU_RESCTRL if PROC_FS
78e99b4a 488 help
e6d42931 489 Enable x86 CPU resource control support.
6fe07ce3
BM
490
491 Provide support for the allocation and monitoring of system resources
492 usage by the CPU.
493
494 Intel calls this Intel Resource Director Technology
495 (Intel(R) RDT). More information about RDT can be found in the
496 Intel x86 Architecture Software Developer Manual.
497
498 AMD calls this AMD Platform Quality of Service (AMD QoS).
499 More information about AMD QoS can be found in the AMD64 Technology
500 Platform Quality of Service Extensions manual.
78e99b4a
FY
501
502 Say N if unsure.
503
8425091f 504if X86_32
a0d0bb4d
RD
505config X86_BIGSMP
506 bool "Support for big SMP systems with more than 8 CPUs"
507 depends on SMP
a7f7f624 508 help
e133f6ea 509 This option is needed for the systems that have more than 8 CPUs.
a0d0bb4d 510
c5c606d9
RT
511config X86_EXTENDED_PLATFORM
512 bool "Support for extended (non-PC) x86 platforms"
513 default y
a7f7f624 514 help
06ac8346
IM
515 If you disable this option then the kernel will only support
516 standard PC platforms. (which covers the vast majority of
517 systems out there.)
518
8425091f
RT
519 If you enable this option then you'll be able to select support
520 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 521 Goldfish (Android emulator)
8425091f 522 AMD Elan
8425091f
RT
523 RDC R-321x SoC
524 SGI 320/540 (Visual Workstation)
83125a3a 525 STA2X11-based (e.g. Northville)
3f4110a4 526 Moorestown MID devices
06ac8346
IM
527
528 If you have one of these systems, or if you want to build a
529 generic distribution kernel, say Y here - otherwise say N.
758cd94a 530endif # X86_32
06ac8346 531
8425091f
RT
532if X86_64
533config X86_EXTENDED_PLATFORM
534 bool "Support for extended (non-PC) x86 platforms"
535 default y
a7f7f624 536 help
8425091f
RT
537 If you disable this option then the kernel will only support
538 standard PC platforms. (which covers the vast majority of
539 systems out there.)
540
541 If you enable this option then you'll be able to select support
542 for the following (non-PC) 64 bit x86 platforms:
44b111b5 543 Numascale NumaChip
8425091f
RT
544 ScaleMP vSMP
545 SGI Ultraviolet
546
547 If you have one of these systems, or if you want to build a
548 generic distribution kernel, say Y here - otherwise say N.
758cd94a 549endif # X86_64
c5c606d9
RT
550# This is an alphabetically sorted list of 64 bit extended platforms
551# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
552config X86_NUMACHIP
553 bool "Numascale NumaChip"
554 depends on X86_64
555 depends on X86_EXTENDED_PLATFORM
556 depends on NUMA
557 depends on SMP
558 depends on X86_X2APIC
f9726bfd 559 depends on PCI_MMCONFIG
a7f7f624 560 help
44b111b5
SP
561 Adds support for Numascale NumaChip large-SMP systems. Needed to
562 enable more than ~168 cores.
563 If you don't have one of these, you should say N here.
506f1d07 564
c5c606d9
RT
565config X86_VSMP
566 bool "ScaleMP vSMP"
6276a074 567 select HYPERVISOR_GUEST
c5c606d9
RT
568 select PARAVIRT
569 depends on X86_64 && PCI
570 depends on X86_EXTENDED_PLATFORM
ead91d4b 571 depends on SMP
a7f7f624 572 help
c5c606d9
RT
573 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
574 supposed to run on these EM64T-based machines. Only choose this option
575 if you have one of these machines.
5e3a77e9 576
03b48632
NP
577config X86_UV
578 bool "SGI Ultraviolet"
579 depends on X86_64
c5c606d9 580 depends on X86_EXTENDED_PLATFORM
54c28d29 581 depends on NUMA
1ecb4ae5 582 depends on EFI
c2209ea5 583 depends on KEXEC_CORE
9d6c26e7 584 depends on X86_X2APIC
1222e564 585 depends on PCI
a7f7f624 586 help
03b48632
NP
587 This option is needed in order to support SGI Ultraviolet systems.
588 If you don't have one of these, you should say N here.
589
c5c606d9
RT
590# Following is an alphabetically sorted list of 32 bit extended platforms
591# Please maintain the alphabetic order if and when there are additions
506f1d07 592
ddd70cf9 593config X86_GOLDFISH
b03b016f
KK
594 bool "Goldfish (Virtual Platform)"
595 depends on X86_EXTENDED_PLATFORM
a7f7f624 596 help
758cd94a
JH
597 Enable support for the Goldfish virtual platform used primarily
598 for Android development. Unless you are building for the Android
599 Goldfish emulator say N here.
ddd70cf9 600
c751e17b
TG
601config X86_INTEL_CE
602 bool "CE4100 TV platform"
603 depends on PCI
604 depends on PCI_GODIRECT
6084a6e2 605 depends on X86_IO_APIC
c751e17b
TG
606 depends on X86_32
607 depends on X86_EXTENDED_PLATFORM
37bc9f50 608 select X86_REBOOTFIXUPS
da6b737b
SAS
609 select OF
610 select OF_EARLY_FLATTREE
a7f7f624 611 help
c751e17b
TG
612 Select for the Intel CE media processor (CE4100) SOC.
613 This option compiles in support for the CE4100 SOC for settop
614 boxes and media devices.
615
4cb9b00f 616config X86_INTEL_MID
43605ef1 617 bool "Intel MID platform support"
43605ef1 618 depends on X86_EXTENDED_PLATFORM
edc6bc78 619 depends on X86_PLATFORM_DEVICES
1ea7c673 620 depends on PCI
3fda5bb4 621 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 622 depends on X86_IO_APIC
4cb9b00f 623 select I2C
7c9c3a1e 624 select DW_APB_TIMER
54b34aa0 625 select INTEL_SCU_PCI
a7f7f624 626 help
4cb9b00f
DC
627 Select to build a kernel capable of supporting Intel MID (Mobile
628 Internet Device) platform systems which do not have the PCI legacy
629 interfaces. If you are building for a PC class system say N here.
1ea7c673 630
4cb9b00f
DC
631 Intel MID platforms are based on an Intel processor and chipset which
632 consume less power than most of the x86 derivatives.
43605ef1 633
8bbc2a13
BD
634config X86_INTEL_QUARK
635 bool "Intel Quark platform support"
636 depends on X86_32
637 depends on X86_EXTENDED_PLATFORM
638 depends on X86_PLATFORM_DEVICES
639 depends on X86_TSC
640 depends on PCI
641 depends on PCI_GOANY
642 depends on X86_IO_APIC
643 select IOSF_MBI
644 select INTEL_IMR
9ab6eb51 645 select COMMON_CLK
a7f7f624 646 help
8bbc2a13
BD
647 Select to include support for Quark X1000 SoC.
648 Say Y here if you have a Quark based system such as the Arduino
649 compatible Intel Galileo.
650
3d48aab1
MW
651config X86_INTEL_LPSS
652 bool "Intel Low Power Subsystem Support"
5962dd22 653 depends on X86 && ACPI && PCI
3d48aab1 654 select COMMON_CLK
0f531431 655 select PINCTRL
eebb3e8d 656 select IOSF_MBI
a7f7f624 657 help
3d48aab1
MW
658 Select to build support for Intel Low Power Subsystem such as
659 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
660 things like clock tree (common clock framework) and pincontrol
661 which are needed by the LPSS peripheral drivers.
3d48aab1 662
92082a88
KX
663config X86_AMD_PLATFORM_DEVICE
664 bool "AMD ACPI2Platform devices support"
665 depends on ACPI
666 select COMMON_CLK
667 select PINCTRL
a7f7f624 668 help
92082a88
KX
669 Select to interpret AMD specific ACPI device to platform device
670 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
671 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
672 implemented under PINCTRL subsystem.
673
ced3ce76
DB
674config IOSF_MBI
675 tristate "Intel SoC IOSF Sideband support for SoC platforms"
676 depends on PCI
a7f7f624 677 help
ced3ce76
DB
678 This option enables sideband register access support for Intel SoC
679 platforms. On these platforms the IOSF sideband is used in lieu of
680 MSR's for some register accesses, mostly but not limited to thermal
681 and power. Drivers may query the availability of this device to
682 determine if they need the sideband in order to work on these
683 platforms. The sideband is available on the following SoC products.
684 This list is not meant to be exclusive.
685 - BayTrail
686 - Braswell
687 - Quark
688
689 You should say Y if you are running a kernel on one of these SoC's.
690
ed2226bd
DB
691config IOSF_MBI_DEBUG
692 bool "Enable IOSF sideband access through debugfs"
693 depends on IOSF_MBI && DEBUG_FS
a7f7f624 694 help
ed2226bd
DB
695 Select this option to expose the IOSF sideband access registers (MCR,
696 MDR, MCRX) through debugfs to write and read register information from
697 different units on the SoC. This is most useful for obtaining device
698 state information for debug and analysis. As this is a general access
699 mechanism, users of this option would have specific knowledge of the
700 device they want to access.
701
702 If you don't require the option or are in doubt, say N.
703
c5c606d9
RT
704config X86_RDC321X
705 bool "RDC R-321x SoC"
506f1d07 706 depends on X86_32
c5c606d9
RT
707 depends on X86_EXTENDED_PLATFORM
708 select M486
709 select X86_REBOOTFIXUPS
a7f7f624 710 help
c5c606d9
RT
711 This option is needed for RDC R-321x system-on-chip, also known
712 as R-8610-(G).
713 If you don't have one of these chips, you should say N here.
714
e0c7ae37 715config X86_32_NON_STANDARD
9c398017
IM
716 bool "Support non-standard 32-bit SMP architectures"
717 depends on X86_32 && SMP
c5c606d9 718 depends on X86_EXTENDED_PLATFORM
a7f7f624 719 help
b5660ba7
PA
720 This option compiles in the bigsmp and STA2X11 default
721 subarchitectures. It is intended for a generic binary
722 kernel. If you select them all, kernel will probe it one by
723 one and will fallback to default.
d49c4288 724
c5c606d9 725# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 726
d949f36f 727config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 728 def_bool y
d949f36f
LT
729 # MCE code calls memory_failure():
730 depends on X86_MCE
731 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
732 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
733 depends on X86_64 || !SPARSEMEM
734 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 735
83125a3a
AR
736config STA2X11
737 bool "STA2X11 Companion Chip Support"
738 depends on X86_32_NON_STANDARD && PCI
83125a3a
AR
739 select SWIOTLB
740 select MFD_STA2X11
0145071b 741 select GPIOLIB
a7f7f624 742 help
83125a3a
AR
743 This adds support for boards based on the STA2X11 IO-Hub,
744 a.k.a. "ConneXt". The chip is used in place of the standard
745 PC chipset, so all "standard" peripherals are missing. If this
746 option is selected the kernel will still be able to boot on
747 standard PC machines.
748
82148d1d
S
749config X86_32_IRIS
750 tristate "Eurobraille/Iris poweroff module"
751 depends on X86_32
a7f7f624 752 help
82148d1d
S
753 The Iris machines from EuroBraille do not have APM or ACPI support
754 to shut themselves down properly. A special I/O sequence is
755 needed to do so, which is what this module does at
756 kernel shutdown.
757
758 This is only for Iris machines from EuroBraille.
759
760 If unused, say N.
761
ae1e9130 762config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
763 def_bool y
764 prompt "Single-depth WCHAN output"
a87d0914 765 depends on X86
a7f7f624 766 help
506f1d07
SR
767 Calculate simpler /proc/<PID>/wchan values. If this option
768 is disabled then wchan values will recurse back to the
769 caller function. This provides more accurate wchan values,
770 at the expense of slightly more scheduling overhead.
771
772 If in doubt, say "Y".
773
6276a074
BP
774menuconfig HYPERVISOR_GUEST
775 bool "Linux guest support"
a7f7f624 776 help
6276a074
BP
777 Say Y here to enable options for running Linux under various hyper-
778 visors. This option enables basic hypervisor detection and platform
779 setup.
506f1d07 780
6276a074
BP
781 If you say N, all options in this submenu will be skipped and
782 disabled, and Linux guest support won't be built in.
506f1d07 783
6276a074 784if HYPERVISOR_GUEST
506f1d07 785
e61bd94a
EPH
786config PARAVIRT
787 bool "Enable paravirtualization code"
a0e2bf7c 788 depends on HAVE_STATIC_CALL
a7f7f624 789 help
e61bd94a
EPH
790 This changes the kernel so it can modify itself when it is run
791 under a hypervisor, potentially improving performance significantly
792 over full virtualization. However, when run without a hypervisor
793 the kernel is theoretically slower and slightly larger.
794
c00a280a
JG
795config PARAVIRT_XXL
796 bool
797
6276a074
BP
798config PARAVIRT_DEBUG
799 bool "paravirt-ops debugging"
800 depends on PARAVIRT && DEBUG_KERNEL
a7f7f624 801 help
6276a074
BP
802 Enable to debug paravirt_ops internals. Specifically, BUG if
803 a paravirt_op is missing when it is called.
804
b4ecc126
JF
805config PARAVIRT_SPINLOCKS
806 bool "Paravirtualization layer for spinlocks"
6ea30386 807 depends on PARAVIRT && SMP
a7f7f624 808 help
b4ecc126
JF
809 Paravirtualized spinlocks allow a pvops backend to replace the
810 spinlock implementation with something virtualization-friendly
811 (for example, block the virtual CPU rather than spinning).
812
4c4e4f61
R
813 It has a minimal impact on native kernels and gives a nice performance
814 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 815
4c4e4f61 816 If you are unsure how to answer this question, answer Y.
b4ecc126 817
ecca2502
ZY
818config X86_HV_CALLBACK_VECTOR
819 def_bool n
820
6276a074 821source "arch/x86/xen/Kconfig"
7af192c9 822
6276a074
BP
823config KVM_GUEST
824 bool "KVM Guest support (including kvmclock)"
825 depends on PARAVIRT
826 select PARAVIRT_CLOCK
a1c4423b 827 select ARCH_CPUIDLE_HALTPOLL
b1d40575 828 select X86_HV_CALLBACK_VECTOR
6276a074 829 default y
a7f7f624 830 help
6276a074
BP
831 This option enables various optimizations for running under the KVM
832 hypervisor. It includes a paravirtualized clock, so that instead
833 of relying on a PIT (or probably other) emulation by the
834 underlying device model, the host provides the guest with
835 timing infrastructure such as time of day, and system time
506f1d07 836
a1c4423b 837config ARCH_CPUIDLE_HALTPOLL
b03b016f
KK
838 def_bool n
839 prompt "Disable host haltpoll when loading haltpoll driver"
840 help
a1c4423b
MT
841 If virtualized under KVM, disable host haltpoll.
842
7733607f
MW
843config PVH
844 bool "Support for running PVH guests"
a7f7f624 845 help
7733607f
MW
846 This option enables the PVH entry point for guest virtual machines
847 as specified in the x86/HVM direct boot ABI.
848
6276a074
BP
849config PARAVIRT_TIME_ACCOUNTING
850 bool "Paravirtual steal time accounting"
851 depends on PARAVIRT
a7f7f624 852 help
6276a074
BP
853 Select this option to enable fine granularity task steal time
854 accounting. Time spent executing other tasks in parallel with
855 the current vCPU is discounted from the vCPU power. To account for
856 that, there can be a small performance impact.
857
858 If in doubt, say N here.
859
860config PARAVIRT_CLOCK
861 bool
97349135 862
4a362601
JK
863config JAILHOUSE_GUEST
864 bool "Jailhouse non-root cell support"
abde587b 865 depends on X86_64 && PCI
87e65d05 866 select X86_PM_TIMER
a7f7f624 867 help
4a362601
JK
868 This option allows to run Linux as guest in a Jailhouse non-root
869 cell. You can leave this option disabled if you only want to start
870 Jailhouse and run Linux afterwards in the root cell.
871
ec7972c9
ZY
872config ACRN_GUEST
873 bool "ACRN Guest support"
874 depends on X86_64
498ad393 875 select X86_HV_CALLBACK_VECTOR
ec7972c9
ZY
876 help
877 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
878 a flexible, lightweight reference open-source hypervisor, built with
879 real-time and safety-criticality in mind. It is built for embedded
880 IOT with small footprint and real-time features. More details can be
881 found in https://projectacrn.org/.
882
59bd54a8
KS
883config INTEL_TDX_GUEST
884 bool "Intel TDX (Trust Domain Extensions) - Guest Support"
885 depends on X86_64 && CPU_SUP_INTEL
886 depends on X86_X2APIC
41394e33 887 select ARCH_HAS_CC_PLATFORM
968b4931 888 select X86_MEM_ENCRYPT
77a512e3 889 select X86_MCE
59bd54a8
KS
890 help
891 Support running as a guest under Intel TDX. Without this support,
892 the guest kernel can not boot or run under TDX.
893 TDX includes memory encryption and integrity capabilities
894 which protect the confidentiality and integrity of guest
895 memory contents and CPU state. TDX guests are protected from
896 some attacks from the VMM.
897
758cd94a 898endif # HYPERVISOR_GUEST
97349135 899
506f1d07
SR
900source "arch/x86/Kconfig.cpu"
901
902config HPET_TIMER
3c2362e6 903 def_bool X86_64
506f1d07 904 prompt "HPET Timer Support" if X86_32
a7f7f624 905 help
8f9ca475
IM
906 Use the IA-PC HPET (High Precision Event Timer) to manage
907 time in preference to the PIT and RTC, if a HPET is
908 present.
909 HPET is the next generation timer replacing legacy 8254s.
910 The HPET provides a stable time base on SMP
911 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
912 as it is off-chip. The interface used is documented
913 in the HPET spec, revision 1.
506f1d07 914
8f9ca475
IM
915 You can safely choose Y here. However, HPET will only be
916 activated if the platform and the BIOS support this feature.
917 Otherwise the 8254 will be used for timing services.
506f1d07 918
8f9ca475 919 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
920
921config HPET_EMULATE_RTC
3c2362e6 922 def_bool y
3228e1dc 923 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 924
6a108a14 925# Mark as expert because too many people got it wrong.
506f1d07 926# The code disables itself when not needed.
7ae9392c
TP
927config DMI
928 default y
cf074402 929 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 930 bool "Enable DMI scanning" if EXPERT
a7f7f624 931 help
7ae9392c
TP
932 Enabled scanning of DMI to identify machine quirks. Say Y
933 here unless you have verified that your setup is not
934 affected by entries in the DMI blacklist. Required by PNP
935 BIOS code.
936
506f1d07 937config GART_IOMMU
38901f1c 938 bool "Old AMD GART IOMMU support"
2f9237d4 939 select DMA_OPS
a4ce5a48 940 select IOMMU_HELPER
506f1d07 941 select SWIOTLB
23ac4ae8 942 depends on X86_64 && PCI && AMD_NB
a7f7f624 943 help
ced3c42c
IM
944 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
945 GART based hardware IOMMUs.
946
947 The GART supports full DMA access for devices with 32-bit access
948 limitations, on systems with more than 3 GB. This is usually needed
949 for USB, sound, many IDE/SATA chipsets and some other devices.
950
951 Newer systems typically have a modern AMD IOMMU, supported via
952 the CONFIG_AMD_IOMMU=y config option.
953
954 In normal configurations this driver is only active when needed:
955 there's more than 3 GB of memory and the system contains a
956 32-bit limited device.
957
958 If unsure, say Y.
506f1d07 959
8b766b0f
MS
960config BOOT_VESA_SUPPORT
961 bool
962 help
963 If true, at least one selected framebuffer driver can take advantage
964 of VESA video modes set at an early boot stage via the vga= parameter.
506f1d07 965
1184dc2f 966config MAXSMP
ddb0c5a6 967 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 968 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 969 select CPUMASK_OFFSTACK
a7f7f624 970 help
ddb0c5a6 971 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 972 If unsure, say N.
506f1d07 973
aec6487e
IM
974#
975# The maximum number of CPUs supported:
976#
977# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
978# and which can be configured interactively in the
979# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
980#
981# The ranges are different on 32-bit and 64-bit kernels, depending on
982# hardware capabilities and scalability features of the kernel.
983#
984# ( If MAXSMP is enabled we just use the highest possible value and disable
985# interactive configuration. )
986#
987
988config NR_CPUS_RANGE_BEGIN
a0d0bb4d 989 int
aec6487e
IM
990 default NR_CPUS_RANGE_END if MAXSMP
991 default 1 if !SMP
992 default 2
a0d0bb4d 993
aec6487e 994config NR_CPUS_RANGE_END
a0d0bb4d 995 int
aec6487e
IM
996 depends on X86_32
997 default 64 if SMP && X86_BIGSMP
998 default 8 if SMP && !X86_BIGSMP
999 default 1 if !SMP
a0d0bb4d 1000
aec6487e 1001config NR_CPUS_RANGE_END
a0d0bb4d 1002 int
aec6487e 1003 depends on X86_64
1edae1ae
SW
1004 default 8192 if SMP && CPUMASK_OFFSTACK
1005 default 512 if SMP && !CPUMASK_OFFSTACK
aec6487e 1006 default 1 if !SMP
a0d0bb4d 1007
aec6487e 1008config NR_CPUS_DEFAULT
a0d0bb4d
RD
1009 int
1010 depends on X86_32
aec6487e
IM
1011 default 32 if X86_BIGSMP
1012 default 8 if SMP
1013 default 1 if !SMP
a0d0bb4d 1014
aec6487e 1015config NR_CPUS_DEFAULT
a0d0bb4d
RD
1016 int
1017 depends on X86_64
aec6487e
IM
1018 default 8192 if MAXSMP
1019 default 64 if SMP
1020 default 1 if !SMP
a0d0bb4d 1021
506f1d07 1022config NR_CPUS
36f5101a 1023 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
1024 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1025 default NR_CPUS_DEFAULT
a7f7f624 1026 help
506f1d07 1027 This allows you to specify the maximum number of CPUs which this
bb61ccc7 1028 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 1029 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
1030 minimum value which makes sense is 2.
1031
aec6487e
IM
1032 This is purely to save memory: each supported CPU adds about 8KB
1033 to the kernel image.
506f1d07 1034
66558b73
TC
1035config SCHED_CLUSTER
1036 bool "Cluster scheduler support"
1037 depends on SMP
1038 default y
1039 help
1040 Cluster scheduler support improves the CPU scheduler's decision
1041 making when dealing with machines that have clusters of CPUs.
1042 Cluster usually means a couple of CPUs which are placed closely
1043 by sharing mid-level caches, last-level cache tags or internal
1044 busses.
1045
506f1d07 1046config SCHED_SMT
dbe73364 1047 def_bool y if SMP
506f1d07
SR
1048
1049config SCHED_MC
3c2362e6
HH
1050 def_bool y
1051 prompt "Multi-core scheduler support"
c8e56d20 1052 depends on SMP
a7f7f624 1053 help
506f1d07
SR
1054 Multi-core scheduler support improves the CPU scheduler's decision
1055 making when dealing with multi-core CPU chips at a cost of slightly
1056 increased overhead in some places. If unsure say N here.
1057
de966cf4
TC
1058config SCHED_MC_PRIO
1059 bool "CPU core priorities scheduler support"
0a21fc12
IM
1060 depends on SCHED_MC && CPU_SUP_INTEL
1061 select X86_INTEL_PSTATE
1062 select CPU_FREQ
de966cf4 1063 default y
a7f7f624 1064 help
0a21fc12
IM
1065 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1066 core ordering determined at manufacturing time, which allows
1067 certain cores to reach higher turbo frequencies (when running
1068 single threaded workloads) than others.
de966cf4 1069
0a21fc12
IM
1070 Enabling this kernel feature teaches the scheduler about
1071 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1072 scheduler's CPU selection logic accordingly, so that higher
1073 overall system performance can be achieved.
de966cf4 1074
0a21fc12 1075 This feature will have no effect on CPUs without this feature.
de966cf4 1076
0a21fc12 1077 If unsure say Y here.
5e76b2ab 1078
30b8b006 1079config UP_LATE_INIT
b03b016f
KK
1080 def_bool y
1081 depends on !SMP && X86_LOCAL_APIC
30b8b006 1082
506f1d07 1083config X86_UP_APIC
50849eef
JB
1084 bool "Local APIC support on uniprocessors" if !PCI_MSI
1085 default PCI_MSI
38a1dfda 1086 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
a7f7f624 1087 help
506f1d07
SR
1088 A local APIC (Advanced Programmable Interrupt Controller) is an
1089 integrated interrupt controller in the CPU. If you have a single-CPU
1090 system which has a processor with a local APIC, you can say Y here to
1091 enable and use it. If you say Y here even though your machine doesn't
1092 have a local APIC, then the kernel will still run with no slowdown at
1093 all. The local APIC supports CPU-generated self-interrupts (timer,
1094 performance counters), and the NMI watchdog which detects hard
1095 lockups.
1096
1097config X86_UP_IOAPIC
1098 bool "IO-APIC support on uniprocessors"
1099 depends on X86_UP_APIC
a7f7f624 1100 help
506f1d07
SR
1101 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1102 SMP-capable replacement for PC-style interrupt controllers. Most
1103 SMP systems and many recent uniprocessor systems have one.
1104
1105 If you have a single-CPU system with an IO-APIC, you can say Y here
1106 to use it. If you say Y here even though your machine doesn't have
1107 an IO-APIC, then the kernel will still run with no slowdown at all.
1108
1109config X86_LOCAL_APIC
3c2362e6 1110 def_bool y
0dbc6078 1111 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1112 select IRQ_DOMAIN_HIERARCHY
506f1d07
SR
1113
1114config X86_IO_APIC
b1da1e71
JB
1115 def_bool y
1116 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1117
41b9eb26
SA
1118config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1119 bool "Reroute for broken boot IRQs"
41b9eb26 1120 depends on X86_IO_APIC
a7f7f624 1121 help
41b9eb26
SA
1122 This option enables a workaround that fixes a source of
1123 spurious interrupts. This is recommended when threaded
1124 interrupt handling is used on systems where the generation of
1125 superfluous "boot interrupts" cannot be disabled.
1126
1127 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1128 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1129 kernel does during interrupt handling). On chipsets where this
1130 boot IRQ generation cannot be disabled, this workaround keeps
1131 the original IRQ line masked so that only the equivalent "boot
1132 IRQ" is delivered to the CPUs. The workaround also tells the
1133 kernel to set up the IRQ handler on the boot IRQ line. In this
1134 way only one interrupt is delivered to the kernel. Otherwise
1135 the spurious second interrupt may cause the kernel to bring
1136 down (vital) interrupt lines.
1137
1138 Only affects "broken" chipsets. Interrupt sharing may be
1139 increased on these systems.
1140
506f1d07 1141config X86_MCE
bab9bc65 1142 bool "Machine Check / overheating reporting"
648ed940 1143 select GENERIC_ALLOCATOR
e57dbaf7 1144 default y
a7f7f624 1145 help
bab9bc65
AK
1146 Machine Check support allows the processor to notify the
1147 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1148 The action the kernel takes depends on the severity of the problem,
bab9bc65 1149 ranging from warning messages to halting the machine.
4efc0670 1150
5de97c9f
TL
1151config X86_MCELOG_LEGACY
1152 bool "Support for deprecated /dev/mcelog character device"
1153 depends on X86_MCE
a7f7f624 1154 help
5de97c9f
TL
1155 Enable support for /dev/mcelog which is needed by the old mcelog
1156 userspace logging daemon. Consider switching to the new generation
1157 rasdaemon solution.
1158
506f1d07 1159config X86_MCE_INTEL
3c2362e6
HH
1160 def_bool y
1161 prompt "Intel MCE features"
c1ebf835 1162 depends on X86_MCE && X86_LOCAL_APIC
a7f7f624 1163 help
758cd94a
JH
1164 Additional support for intel specific MCE features such as
1165 the thermal monitor.
506f1d07
SR
1166
1167config X86_MCE_AMD
3c2362e6
HH
1168 def_bool y
1169 prompt "AMD MCE features"
f5382de9 1170 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
a7f7f624 1171 help
758cd94a
JH
1172 Additional support for AMD specific MCE features such as
1173 the DRAM Error Threshold.
506f1d07 1174
4efc0670 1175config X86_ANCIENT_MCE
6fc108a0 1176 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1177 depends on X86_32 && X86_MCE
a7f7f624 1178 help
cd13adcc 1179 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1180 systems. These typically need to be enabled explicitly on the command
cd13adcc 1181 line.
4efc0670 1182
b2762686
AK
1183config X86_MCE_THRESHOLD
1184 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1185 def_bool y
b2762686 1186
ea149b36 1187config X86_MCE_INJECT
bc8e80d5 1188 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36 1189 tristate "Machine check injector support"
a7f7f624 1190 help
ea149b36
AK
1191 Provide support for injecting machine checks for testing purposes.
1192 If you don't know what a machine check is and you don't do kernel
1193 QA it is safe to say n.
1194
07dc900e 1195source "arch/x86/events/Kconfig"
e633c65a 1196
5aef51c3 1197config X86_LEGACY_VM86
1e642812 1198 bool "Legacy VM86 support"
506f1d07 1199 depends on X86_32
a7f7f624 1200 help
5aef51c3
AL
1201 This option allows user programs to put the CPU into V8086
1202 mode, which is an 80286-era approximation of 16-bit real mode.
1203
1204 Some very old versions of X and/or vbetool require this option
1205 for user mode setting. Similarly, DOSEMU will use it if
1206 available to accelerate real mode DOS programs. However, any
1207 recent version of DOSEMU, X, or vbetool should be fully
1208 functional even without kernel VM86 support, as they will all
1e642812
IM
1209 fall back to software emulation. Nevertheless, if you are using
1210 a 16-bit DOS program where 16-bit performance matters, vm86
1211 mode might be faster than emulation and you might want to
1212 enable this option.
5aef51c3 1213
1e642812
IM
1214 Note that any app that works on a 64-bit kernel is unlikely to
1215 need this option, as 64-bit kernels don't, and can't, support
1216 V8086 mode. This option is also unrelated to 16-bit protected
1217 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1218
1e642812
IM
1219 Enabling this option increases the complexity of the kernel
1220 and slows down exception handling a tiny bit.
5aef51c3 1221
1e642812 1222 If unsure, say N here.
5aef51c3
AL
1223
1224config VM86
b03b016f
KK
1225 bool
1226 default X86_LEGACY_VM86
34273f41
PA
1227
1228config X86_16BIT
1229 bool "Enable support for 16-bit segments" if EXPERT
1230 default y
a5b9e5a2 1231 depends on MODIFY_LDT_SYSCALL
a7f7f624 1232 help
34273f41
PA
1233 This option is required by programs like Wine to run 16-bit
1234 protected mode legacy code on x86 processors. Disabling
1235 this option saves about 300 bytes on i386, or around 6K text
1236 plus 16K runtime memory on x86-64,
1237
1238config X86_ESPFIX32
1239 def_bool y
1240 depends on X86_16BIT && X86_32
506f1d07 1241
197725de
PA
1242config X86_ESPFIX64
1243 def_bool y
34273f41 1244 depends on X86_16BIT && X86_64
506f1d07 1245
1ad83c85 1246config X86_VSYSCALL_EMULATION
b03b016f
KK
1247 bool "Enable vsyscall emulation" if EXPERT
1248 default y
1249 depends on X86_64
a7f7f624 1250 help
758cd94a
JH
1251 This enables emulation of the legacy vsyscall page. Disabling
1252 it is roughly equivalent to booting with vsyscall=none, except
1253 that it will also disable the helpful warning if a program
1254 tries to use a vsyscall. With this option set to N, offending
1255 programs will just segfault, citing addresses of the form
1256 0xffffffffff600?00.
1ad83c85 1257
758cd94a
JH
1258 This option is required by many programs built before 2013, and
1259 care should be used even with newer programs if set to N.
1ad83c85 1260
758cd94a
JH
1261 Disabling this option saves about 7K of kernel size and
1262 possibly 4K of additional runtime pagetable memory.
1ad83c85 1263
111e7b15
TG
1264config X86_IOPL_IOPERM
1265 bool "IOPERM and IOPL Emulation"
a24ca997 1266 default y
a7f7f624 1267 help
111e7b15
TG
1268 This enables the ioperm() and iopl() syscalls which are necessary
1269 for legacy applications.
1270
c8137ace
TG
1271 Legacy IOPL support is an overbroad mechanism which allows user
1272 space aside of accessing all 65536 I/O ports also to disable
1273 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1274 capabilities and permission from potentially active security
1275 modules.
1276
1277 The emulation restricts the functionality of the syscall to
1278 only allowing the full range I/O port access, but prevents the
a24ca997
TG
1279 ability to disable interrupts from user space which would be
1280 granted if the hardware IOPL mechanism would be used.
c8137ace 1281
506f1d07
SR
1282config TOSHIBA
1283 tristate "Toshiba Laptop support"
1284 depends on X86_32
a7f7f624 1285 help
506f1d07
SR
1286 This adds a driver to safely access the System Management Mode of
1287 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1288 not work on models with a Phoenix BIOS. The System Management Mode
1289 is used to set the BIOS and power saving options on Toshiba portables.
1290
1291 For information on utilities to make use of this driver see the
1292 Toshiba Linux utilities web site at:
1293 <http://www.buzzard.org.uk/toshiba/>.
1294
1295 Say Y if you intend to run this kernel on a Toshiba portable.
1296 Say N otherwise.
1297
506f1d07 1298config X86_REBOOTFIXUPS
9ba16087
JB
1299 bool "Enable X86 board specific fixups for reboot"
1300 depends on X86_32
a7f7f624 1301 help
506f1d07
SR
1302 This enables chipset and/or board specific fixups to be done
1303 in order to get reboot to work correctly. This is only needed on
1304 some combinations of hardware and BIOS. The symptom, for which
1305 this config is intended, is when reboot ends with a stalled/hung
1306 system.
1307
1308 Currently, the only fixup is for the Geode machines using
5e3a77e9 1309 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1310
1311 Say Y if you want to enable the fixup. Currently, it's safe to
1312 enable this option even if you don't need it.
1313 Say N otherwise.
1314
1315config MICROCODE
9a2bc335
BP
1316 bool "CPU microcode loading support"
1317 default y
80030e3d 1318 depends on CPU_SUP_AMD || CPU_SUP_INTEL
a7f7f624 1319 help
506f1d07 1320 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1321 Intel and AMD processors. The Intel support is for the IA32 family,
1322 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1323 AMD support is for families 0x10 and later. You will obviously need
1324 the actual microcode binary data itself which is not shipped with
1325 the Linux kernel.
1326
1327 The preferred method to load microcode from a detached initrd is described
ff61f079 1328 in Documentation/arch/x86/microcode.rst. For that you need to enable
5f9c01aa
BP
1329 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1330 initrd for microcode blobs.
1331
c508c46e
BG
1332 In addition, you can build the microcode into the kernel. For that you
1333 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1334 config option.
506f1d07 1335
8d86f390 1336config MICROCODE_INTEL
e43f6e67 1337 bool "Intel microcode loading support"
9c55d99e 1338 depends on CPU_SUP_INTEL && MICROCODE
8f9ca475 1339 default MICROCODE
a7f7f624 1340 help
8f9ca475
IM
1341 This options enables microcode patch loading support for Intel
1342 processors.
1343
b8989db9
A
1344 For the current Intel microcode data package go to
1345 <https://downloadcenter.intel.com> and search for
1346 'Linux Processor Microcode Data File'.
8d86f390 1347
80cc9f10 1348config MICROCODE_AMD
e43f6e67 1349 bool "AMD microcode loading support"
9c55d99e 1350 depends on CPU_SUP_AMD && MICROCODE
a7f7f624 1351 help
8f9ca475
IM
1352 If you select this option, microcode patch loading support for AMD
1353 processors will be enabled.
80cc9f10 1354
a77a94f8
BP
1355config MICROCODE_LATE_LOADING
1356 bool "Late microcode loading (DANGEROUS)"
c02f48e0 1357 default n
506f1d07 1358 depends on MICROCODE
a7f7f624 1359 help
a77a94f8
BP
1360 Loading microcode late, when the system is up and executing instructions
1361 is a tricky business and should be avoided if possible. Just the sequence
1362 of synchronizing all cores and SMT threads is one fragile dance which does
1363 not guarantee that cores might not softlock after the loading. Therefore,
1364 use this at your own risk. Late loading taints the kernel too.
506f1d07
SR
1365
1366config X86_MSR
1367 tristate "/dev/cpu/*/msr - Model-specific register support"
a7f7f624 1368 help
506f1d07
SR
1369 This device gives privileged processes access to the x86
1370 Model-Specific Registers (MSRs). It is a character device with
1371 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1372 MSR accesses are directed to a specific CPU on multi-processor
1373 systems.
1374
1375config X86_CPUID
1376 tristate "/dev/cpu/*/cpuid - CPU information support"
a7f7f624 1377 help
506f1d07
SR
1378 This device gives processes access to the x86 CPUID instruction to
1379 be executed on a specific processor. It is a character device
1380 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1381 /dev/cpu/31/cpuid.
1382
1383choice
1384 prompt "High Memory Support"
6fc108a0 1385 default HIGHMEM4G
506f1d07
SR
1386 depends on X86_32
1387
1388config NOHIGHMEM
1389 bool "off"
a7f7f624 1390 help
506f1d07
SR
1391 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1392 However, the address space of 32-bit x86 processors is only 4
1393 Gigabytes large. That means that, if you have a large amount of
1394 physical memory, not all of it can be "permanently mapped" by the
1395 kernel. The physical memory that's not permanently mapped is called
1396 "high memory".
1397
1398 If you are compiling a kernel which will never run on a machine with
1399 more than 1 Gigabyte total physical RAM, answer "off" here (default
1400 choice and suitable for most users). This will result in a "3GB/1GB"
1401 split: 3GB are mapped so that each process sees a 3GB virtual memory
1402 space and the remaining part of the 4GB virtual memory space is used
1403 by the kernel to permanently map as much physical memory as
1404 possible.
1405
1406 If the machine has between 1 and 4 Gigabytes physical RAM, then
1407 answer "4GB" here.
1408
1409 If more than 4 Gigabytes is used then answer "64GB" here. This
1410 selection turns Intel PAE (Physical Address Extension) mode on.
1411 PAE implements 3-level paging on IA32 processors. PAE is fully
1412 supported by Linux, PAE mode is implemented on all recent Intel
1413 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1414 then the kernel will not boot on CPUs that don't support PAE!
1415
1416 The actual amount of total physical memory will either be
1417 auto detected or can be forced by using a kernel command line option
1418 such as "mem=256M". (Try "man bootparam" or see the documentation of
1419 your boot loader (lilo or loadlin) about how to pass options to the
1420 kernel at boot time.)
1421
1422 If unsure, say "off".
1423
1424config HIGHMEM4G
1425 bool "4GB"
a7f7f624 1426 help
506f1d07
SR
1427 Select this if you have a 32-bit processor and between 1 and 4
1428 gigabytes of physical RAM.
1429
1430config HIGHMEM64G
1431 bool "64GB"
225bac2d 1432 depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
506f1d07 1433 select X86_PAE
a7f7f624 1434 help
506f1d07
SR
1435 Select this if you have a 32-bit processor and more than 4
1436 gigabytes of physical RAM.
1437
1438endchoice
1439
1440choice
6a108a14 1441 prompt "Memory split" if EXPERT
506f1d07
SR
1442 default VMSPLIT_3G
1443 depends on X86_32
a7f7f624 1444 help
506f1d07
SR
1445 Select the desired split between kernel and user memory.
1446
1447 If the address range available to the kernel is less than the
1448 physical memory installed, the remaining memory will be available
1449 as "high memory". Accessing high memory is a little more costly
1450 than low memory, as it needs to be mapped into the kernel first.
1451 Note that increasing the kernel address space limits the range
1452 available to user programs, making the address space there
1453 tighter. Selecting anything other than the default 3G/1G split
1454 will also likely make your kernel incompatible with binary-only
1455 kernel modules.
1456
1457 If you are not absolutely sure what you are doing, leave this
1458 option alone!
1459
1460 config VMSPLIT_3G
1461 bool "3G/1G user/kernel split"
1462 config VMSPLIT_3G_OPT
1463 depends on !X86_PAE
1464 bool "3G/1G user/kernel split (for full 1G low memory)"
1465 config VMSPLIT_2G
1466 bool "2G/2G user/kernel split"
1467 config VMSPLIT_2G_OPT
1468 depends on !X86_PAE
1469 bool "2G/2G user/kernel split (for full 2G low memory)"
1470 config VMSPLIT_1G
1471 bool "1G/3G user/kernel split"
1472endchoice
1473
1474config PAGE_OFFSET
1475 hex
1476 default 0xB0000000 if VMSPLIT_3G_OPT
1477 default 0x80000000 if VMSPLIT_2G
1478 default 0x78000000 if VMSPLIT_2G_OPT
1479 default 0x40000000 if VMSPLIT_1G
1480 default 0xC0000000
1481 depends on X86_32
1482
1483config HIGHMEM
3c2362e6 1484 def_bool y
506f1d07 1485 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1486
1487config X86_PAE
9ba16087 1488 bool "PAE (Physical Address Extension) Support"
506f1d07 1489 depends on X86_32 && !HIGHMEM4G
d4a451d5 1490 select PHYS_ADDR_T_64BIT
9d99c712 1491 select SWIOTLB
a7f7f624 1492 help
506f1d07
SR
1493 PAE is required for NX support, and furthermore enables
1494 larger swapspace support for non-overcommit purposes. It
1495 has the cost of more pagetable lookup overhead, and also
1496 consumes more pagetable space per process.
1497
77ef56e4
KS
1498config X86_5LEVEL
1499 bool "Enable 5-level page tables support"
18ec1eaf 1500 default y
eedb92ab 1501 select DYNAMIC_MEMORY_LAYOUT
162434e7 1502 select SPARSEMEM_VMEMMAP
77ef56e4 1503 depends on X86_64
a7f7f624 1504 help
77ef56e4 1505 5-level paging enables access to larger address space:
54628de6 1506 up to 128 PiB of virtual address space and 4 PiB of
77ef56e4
KS
1507 physical address space.
1508
1509 It will be supported by future Intel CPUs.
1510
6657fca0
KS
1511 A kernel with the option enabled can be booted on machines that
1512 support 4- or 5-level paging.
77ef56e4 1513
ff61f079 1514 See Documentation/arch/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1515 information.
1516
1517 Say N if unsure.
1518
10971ab2 1519config X86_DIRECT_GBPAGES
e5008abe 1520 def_bool y
2e1da13f 1521 depends on X86_64
a7f7f624 1522 help
10971ab2
IM
1523 Certain kernel features effectively disable kernel
1524 linear 1 GB mappings (even if the CPU otherwise
1525 supports them), so don't confuse the user by printing
1526 that we have them enabled.
9e899816 1527
5c280cf6
TG
1528config X86_CPA_STATISTICS
1529 bool "Enable statistic for Change Page Attribute"
1530 depends on DEBUG_FS
a7f7f624 1531 help
b75baaf3 1532 Expose statistics about the Change Page Attribute mechanism, which
a943245a 1533 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1534 page mappings when mapping protections are changed.
1535
20f07a04
KS
1536config X86_MEM_ENCRYPT
1537 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1538 select DYNAMIC_PHYSICAL_MASK
20f07a04
KS
1539 def_bool n
1540
7744ccdb
TL
1541config AMD_MEM_ENCRYPT
1542 bool "AMD Secure Memory Encryption (SME) support"
1543 depends on X86_64 && CPU_SUP_AMD
82fef0ad 1544 select DMA_COHERENT_POOL
ce9084ba 1545 select ARCH_USE_MEMREMAP_PROT
597cfe48 1546 select INSTRUCTION_DECODER
aa5a4611 1547 select ARCH_HAS_CC_PLATFORM
20f07a04 1548 select X86_MEM_ENCRYPT
a7f7f624 1549 help
7744ccdb
TL
1550 Say yes to enable support for the encryption of system memory.
1551 This requires an AMD processor that supports Secure Memory
1552 Encryption (SME).
1553
1554config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1555 bool "Activate AMD Secure Memory Encryption (SME) by default"
7744ccdb 1556 depends on AMD_MEM_ENCRYPT
a7f7f624 1557 help
7744ccdb
TL
1558 Say yes to have system memory encrypted by default if running on
1559 an AMD processor that supports Secure Memory Encryption (SME).
1560
1561 If set to Y, then the encryption of system memory can be
1562 deactivated with the mem_encrypt=off command line option.
1563
1564 If set to N, then the encryption of system memory can be
1565 activated with the mem_encrypt=on command line option.
1566
506f1d07
SR
1567# Common NUMA Features
1568config NUMA
e133f6ea 1569 bool "NUMA Memory Allocation and Scheduler Support"
506f1d07 1570 depends on SMP
b5660ba7
PA
1571 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1572 default y if X86_BIGSMP
7ecd19cf 1573 select USE_PERCPU_NUMA_NODE_ID
a7f7f624 1574 help
e133f6ea 1575 Enable NUMA (Non-Uniform Memory Access) support.
fd51b2d7 1576
506f1d07
SR
1577 The kernel will try to allocate memory used by a CPU on the
1578 local memory controller of the CPU and add some more
1579 NUMA awareness to the kernel.
1580
c280ea5e 1581 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1582 (or later), AMD Opteron, or EM64T NUMA.
1583
b5660ba7 1584 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1585 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1586
1587 Otherwise, you should say N.
506f1d07 1588
eec1d4fa 1589config AMD_NUMA
3c2362e6
HH
1590 def_bool y
1591 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1592 depends on X86_64 && NUMA && PCI
a7f7f624 1593 help
eec1d4fa
HR
1594 Enable AMD NUMA node topology detection. You should say Y here if
1595 you have a multi processor AMD system. This uses an old method to
1596 read the NUMA configuration directly from the builtin Northbridge
1597 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1598 which also takes priority if both are compiled in.
506f1d07
SR
1599
1600config X86_64_ACPI_NUMA
3c2362e6
HH
1601 def_bool y
1602 prompt "ACPI NUMA detection"
506f1d07
SR
1603 depends on X86_64 && NUMA && ACPI && PCI
1604 select ACPI_NUMA
a7f7f624 1605 help
506f1d07
SR
1606 Enable ACPI SRAT based node topology detection.
1607
1608config NUMA_EMU
1609 bool "NUMA emulation"
1b7e03ef 1610 depends on NUMA
a7f7f624 1611 help
506f1d07
SR
1612 Enable NUMA emulation. A flat machine will be split
1613 into virtual nodes when booted with "numa=fake=N", where N is the
1614 number of nodes. This is only useful for debugging.
1615
1616config NODES_SHIFT
d25e26b6 1617 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1618 range 1 10
1619 default "10" if MAXSMP
506f1d07 1620 default "6" if X86_64
506f1d07 1621 default "3"
a9ee6cf5 1622 depends on NUMA
a7f7f624 1623 help
1184dc2f 1624 Specify the maximum number of NUMA Nodes available on the target
692105b8 1625 system. Increases memory reserved to accommodate various tables.
506f1d07 1626
506f1d07
SR
1627config ARCH_FLATMEM_ENABLE
1628 def_bool y
3b16651f 1629 depends on X86_32 && !NUMA
506f1d07 1630
506f1d07
SR
1631config ARCH_SPARSEMEM_ENABLE
1632 def_bool y
6ea30386 1633 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1634 select SPARSEMEM_STATIC if X86_32
1635 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1636
3b16651f 1637config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1638 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1639
506f1d07
SR
1640config ARCH_SELECT_MEMORY_MODEL
1641 def_bool y
4eda2bc3 1642 depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
506f1d07
SR
1643
1644config ARCH_MEMORY_PROBE
a0842b70 1645 bool "Enable sysfs memory/probe interface"
5c11f00b 1646 depends on MEMORY_HOTPLUG
a0842b70
TK
1647 help
1648 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1649 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1650 If you are unsure how to answer this question, answer N.
506f1d07 1651
3b16651f
TH
1652config ARCH_PROC_KCORE_TEXT
1653 def_bool y
1654 depends on X86_64 && PROC_KCORE
1655
a29815a3 1656config ILLEGAL_POINTER_VALUE
b03b016f
KK
1657 hex
1658 default 0 if X86_32
1659 default 0xdead000000000000 if X86_64
a29815a3 1660
7a67832c
DW
1661config X86_PMEM_LEGACY_DEVICE
1662 bool
1663
ec776ef6 1664config X86_PMEM_LEGACY
7a67832c 1665 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1666 depends on PHYS_ADDR_T_64BIT
1667 depends on BLK_DEV
7a67832c 1668 select X86_PMEM_LEGACY_DEVICE
7b27a862 1669 select NUMA_KEEP_MEMINFO if NUMA
9f53f9fa 1670 select LIBNVDIMM
ec776ef6
CH
1671 help
1672 Treat memory marked using the non-standard e820 type of 12 as used
1673 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1674 The kernel will offer these regions to the 'pmem' driver so
1675 they can be used for persistent storage.
1676
1677 Say Y if unsure.
1678
506f1d07
SR
1679config HIGHPTE
1680 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1681 depends on HIGHMEM
a7f7f624 1682 help
506f1d07
SR
1683 The VM uses one page table entry for each page of physical memory.
1684 For systems with a lot of RAM, this can be wasteful of precious
1685 low memory. Setting this option will put user-space page table
1686 entries in high memory.
1687
9f077871 1688config X86_CHECK_BIOS_CORRUPTION
8f9ca475 1689 bool "Check for low memory corruption"
a7f7f624 1690 help
8f9ca475
IM
1691 Periodically check for memory corruption in low memory, which
1692 is suspected to be caused by BIOS. Even when enabled in the
1693 configuration, it is disabled at runtime. Enable it by
1694 setting "memory_corruption_check=1" on the kernel command
1695 line. By default it scans the low 64k of memory every 60
1696 seconds; see the memory_corruption_check_size and
1697 memory_corruption_check_period parameters in
8c27ceff 1698 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1699
1700 When enabled with the default parameters, this option has
1701 almost no overhead, as it reserves a relatively small amount
1702 of memory and scans it infrequently. It both detects corruption
1703 and prevents it from affecting the running system.
1704
1705 It is, however, intended as a diagnostic tool; if repeatable
1706 BIOS-originated corruption always affects the same memory,
1707 you can use memmap= to prevent the kernel from using that
1708 memory.
9f077871 1709
c885df50 1710config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1711 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1712 depends on X86_CHECK_BIOS_CORRUPTION
1713 default y
a7f7f624 1714 help
8f9ca475
IM
1715 Set whether the default state of memory_corruption_check is
1716 on or off.
c885df50 1717
506f1d07
SR
1718config MATH_EMULATION
1719 bool
a5b9e5a2 1720 depends on MODIFY_LDT_SYSCALL
87d6021b 1721 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
a7f7f624 1722 help
506f1d07
SR
1723 Linux can emulate a math coprocessor (used for floating point
1724 operations) if you don't have one. 486DX and Pentium processors have
1725 a math coprocessor built in, 486SX and 386 do not, unless you added
1726 a 487DX or 387, respectively. (The messages during boot time can
1727 give you some hints here ["man dmesg"].) Everyone needs either a
1728 coprocessor or this emulation.
1729
1730 If you don't have a math coprocessor, you need to say Y here; if you
1731 say Y here even though you have a coprocessor, the coprocessor will
1732 be used nevertheless. (This behavior can be changed with the kernel
1733 command line option "no387", which comes handy if your coprocessor
1734 is broken. Try "man bootparam" or see the documentation of your boot
1735 loader (lilo or loadlin) about how to pass options to the kernel at
1736 boot time.) This means that it is a good idea to say Y here if you
1737 intend to use this kernel on different machines.
1738
1739 More information about the internals of the Linux math coprocessor
1740 emulation can be found in <file:arch/x86/math-emu/README>.
1741
1742 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1743 kernel, it won't hurt.
1744
1745config MTRR
6fc108a0 1746 def_bool y
6a108a14 1747 prompt "MTRR (Memory Type Range Register) support" if EXPERT
a7f7f624 1748 help
506f1d07
SR
1749 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1750 the Memory Type Range Registers (MTRRs) may be used to control
1751 processor access to memory ranges. This is most useful if you have
1752 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1753 allows bus write transfers to be combined into a larger transfer
1754 before bursting over the PCI/AGP bus. This can increase performance
1755 of image write operations 2.5 times or more. Saying Y here creates a
1756 /proc/mtrr file which may be used to manipulate your processor's
1757 MTRRs. Typically the X server should use this.
1758
1759 This code has a reasonably generic interface so that similar
1760 control registers on other processors can be easily supported
1761 as well:
1762
1763 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1764 Registers (ARRs) which provide a similar functionality to MTRRs. For
1765 these, the ARRs are used to emulate the MTRRs.
1766 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1767 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1768 write-combining. All of these processors are supported by this code
1769 and it makes sense to say Y here if you have one of them.
1770
1771 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1772 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1773 can lead to all sorts of problems, so it's good to say Y here.
1774
1775 You can safely say Y even if your machine doesn't have MTRRs, you'll
1776 just add about 9 KB to your kernel.
1777
ff61f079 1778 See <file:Documentation/arch/x86/mtrr.rst> for more information.
506f1d07 1779
95ffa243 1780config MTRR_SANITIZER
2ffb3501 1781 def_bool y
95ffa243
YL
1782 prompt "MTRR cleanup support"
1783 depends on MTRR
a7f7f624 1784 help
aba3728c
TG
1785 Convert MTRR layout from continuous to discrete, so X drivers can
1786 add writeback entries.
95ffa243 1787
aba3728c 1788 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1789 The largest mtrr entry size for a continuous block can be set with
aba3728c 1790 mtrr_chunk_size.
95ffa243 1791
2ffb3501 1792 If unsure, say Y.
95ffa243
YL
1793
1794config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1795 int "MTRR cleanup enable value (0-1)"
1796 range 0 1
1797 default "0"
95ffa243 1798 depends on MTRR_SANITIZER
a7f7f624 1799 help
f5098d62 1800 Enable mtrr cleanup default value
95ffa243 1801
12031a62
YL
1802config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1803 int "MTRR cleanup spare reg num (0-7)"
1804 range 0 7
1805 default "1"
1806 depends on MTRR_SANITIZER
a7f7f624 1807 help
12031a62 1808 mtrr cleanup spare entries default, it can be changed via
aba3728c 1809 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1810
2e5d9c85 1811config X86_PAT
6fc108a0 1812 def_bool y
6a108a14 1813 prompt "x86 PAT support" if EXPERT
2a8a2719 1814 depends on MTRR
a7f7f624 1815 help
2e5d9c85 1816 Use PAT attributes to setup page level cache control.
042b78e4 1817
2e5d9c85 1818 PATs are the modern equivalents of MTRRs and are much more
1819 flexible than MTRRs.
1820
1821 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1822 spontaneous reboots) or a non-working video driver.
2e5d9c85 1823
1824 If unsure, say Y.
1825
46cf98cd
VP
1826config ARCH_USES_PG_UNCACHED
1827 def_bool y
1828 depends on X86_PAT
1829
b971880f 1830config X86_UMIP
796ebc81 1831 def_bool y
b971880f 1832 prompt "User Mode Instruction Prevention" if EXPERT
a7f7f624 1833 help
b971880f
BM
1834 User Mode Instruction Prevention (UMIP) is a security feature in
1835 some x86 processors. If enabled, a general protection fault is
1836 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1837 executed in user mode. These instructions unnecessarily expose
1838 information about the hardware state.
796ebc81
RN
1839
1840 The vast majority of applications do not use these instructions.
1841 For the very few that do, software emulation is provided in
1842 specific cases in protected and virtual-8086 modes. Emulated
1843 results are dummy.
aa35f896 1844
156ff4a5
PZ
1845config CC_HAS_IBT
1846 # GCC >= 9 and binutils >= 2.29
1847 # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1848 # Clang/LLVM >= 14
262448f3
NC
1849 # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1850 # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
156ff4a5 1851 def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
262448f3 1852 (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
156ff4a5
PZ
1853 $(as-instr,endbr64)
1854
1855config X86_KERNEL_IBT
1856 prompt "Indirect Branch Tracking"
4fd5f70c 1857 def_bool y
03f16cd0 1858 depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
f6a2c2b2
NC
1859 # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1860 depends on !LD_IS_LLD || LLD_VERSION >= 140000
03f16cd0 1861 select OBJTOOL
156ff4a5
PZ
1862 help
1863 Build the kernel with support for Indirect Branch Tracking, a
1864 hardware support course-grain forward-edge Control Flow Integrity
1865 protection. It enforces that all indirect calls must land on
1866 an ENDBR instruction, as such, the compiler will instrument the
1867 code with them to make this happen.
1868
ed53a0d9 1869 In addition to building the kernel with IBT, seal all functions that
4cdfc11b 1870 are not indirect call targets, avoiding them ever becoming one.
ed53a0d9
PZ
1871
1872 This requires LTO like objtool runs and will slow down the build. It
1873 does significantly reduce the number of ENDBR instructions in the
1874 kernel image.
1875
35e97790 1876config X86_INTEL_MEMORY_PROTECTION_KEYS
38f3e775 1877 prompt "Memory Protection Keys"
35e97790 1878 def_bool y
284244a9 1879 # Note: only available in 64-bit mode
38f3e775 1880 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
52c8e601
IM
1881 select ARCH_USES_HIGH_VMA_FLAGS
1882 select ARCH_HAS_PKEYS
a7f7f624 1883 help
284244a9
DH
1884 Memory Protection Keys provides a mechanism for enforcing
1885 page-based protections, but without requiring modification of the
1886 page tables when an application changes protection domains.
1887
1eecbcdc 1888 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1889
1890 If unsure, say y.
35e97790 1891
db616173
MH
1892choice
1893 prompt "TSX enable mode"
1894 depends on CPU_SUP_INTEL
1895 default X86_INTEL_TSX_MODE_OFF
1896 help
1897 Intel's TSX (Transactional Synchronization Extensions) feature
1898 allows to optimize locking protocols through lock elision which
1899 can lead to a noticeable performance boost.
1900
1901 On the other hand it has been shown that TSX can be exploited
1902 to form side channel attacks (e.g. TAA) and chances are there
1903 will be more of those attacks discovered in the future.
1904
1905 Therefore TSX is not enabled by default (aka tsx=off). An admin
1906 might override this decision by tsx=on the command line parameter.
1907 Even with TSX enabled, the kernel will attempt to enable the best
1908 possible TAA mitigation setting depending on the microcode available
1909 for the particular machine.
1910
1911 This option allows to set the default tsx mode between tsx=on, =off
1912 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1913 details.
1914
1915 Say off if not sure, auto if TSX is in use but it should be used on safe
1916 platforms or on if TSX is in use and the security aspect of tsx is not
1917 relevant.
1918
1919config X86_INTEL_TSX_MODE_OFF
1920 bool "off"
1921 help
1922 TSX is disabled if possible - equals to tsx=off command line parameter.
1923
1924config X86_INTEL_TSX_MODE_ON
1925 bool "on"
1926 help
1927 TSX is always enabled on TSX capable HW - equals the tsx=on command
1928 line parameter.
1929
1930config X86_INTEL_TSX_MODE_AUTO
1931 bool "auto"
1932 help
1933 TSX is enabled on TSX capable HW that is believed to be safe against
1934 side channel attacks- equals the tsx=auto command line parameter.
1935endchoice
1936
e7e05452
SC
1937config X86_SGX
1938 bool "Software Guard eXtensions (SGX)"
b8d1d163 1939 depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
e7e05452
SC
1940 depends on CRYPTO=y
1941 depends on CRYPTO_SHA256=y
e7e05452 1942 select MMU_NOTIFIER
901ddbb9 1943 select NUMA_KEEP_MEMINFO if NUMA
40e0e784 1944 select XARRAY_MULTI
e7e05452
SC
1945 help
1946 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1947 that can be used by applications to set aside private regions of code
1948 and data, referred to as enclaves. An enclave's private memory can
1949 only be accessed by code running within the enclave. Accesses from
1950 outside the enclave, including other enclaves, are disallowed by
1951 hardware.
1952
1953 If unsure, say N.
1954
506f1d07 1955config EFI
9ba16087 1956 bool "EFI runtime service support"
5b83683f 1957 depends on ACPI
f6ce5002 1958 select UCS2_STRING
022ee6c5 1959 select EFI_RUNTIME_WRAPPERS
1ff2fc02 1960 select ARCH_USE_MEMREMAP_PROT
a7f7f624 1961 help
8f9ca475
IM
1962 This enables the kernel to use EFI runtime services that are
1963 available (such as the EFI variable services).
506f1d07 1964
8f9ca475
IM
1965 This option is only useful on systems that have EFI firmware.
1966 In addition, you should use the latest ELILO loader available
1967 at <http://elilo.sourceforge.net> in order to take advantage
1968 of EFI runtime services. However, even with this option, the
1969 resultant kernel should continue to boot on existing non-EFI
1970 platforms.
506f1d07 1971
291f3632 1972config EFI_STUB
8f24f8c2 1973 bool "EFI stub support"
c6dbd3e5 1974 depends on EFI
8f24f8c2 1975 select RELOCATABLE
a7f7f624 1976 help
8f24f8c2 1977 This kernel feature allows a bzImage to be loaded directly
291f3632
MF
1978 by EFI firmware without the use of a bootloader.
1979
4f4cfa6c 1980 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 1981
cc3fdda2
AB
1982config EFI_HANDOVER_PROTOCOL
1983 bool "EFI handover protocol (DEPRECATED)"
1984 depends on EFI_STUB
1985 default y
1986 help
1987 Select this in order to include support for the deprecated EFI
1988 handover protocol, which defines alternative entry points into the
1989 EFI stub. This is a practice that has no basis in the UEFI
1990 specification, and requires a priori knowledge on the part of the
1991 bootloader about Linux/x86 specific ways of passing the command line
1992 and initrd, and where in memory those assets may be loaded.
1993
1994 If in doubt, say Y. Even though the corresponding support is not
1995 present in upstream GRUB or other bootloaders, most distros build
1996 GRUB with numerous downstream patches applied, and may rely on the
1997 handover protocol as as result.
1998
7d453eee
MF
1999config EFI_MIXED
2000 bool "EFI mixed-mode support"
2001 depends on EFI_STUB && X86_64
a7f7f624 2002 help
758cd94a
JH
2003 Enabling this feature allows a 64-bit kernel to be booted
2004 on a 32-bit firmware, provided that your CPU supports 64-bit
2005 mode.
7d453eee 2006
758cd94a
JH
2007 Note that it is not possible to boot a mixed-mode enabled
2008 kernel via the EFI boot stub - a bootloader that supports
2009 the EFI handover protocol must be used.
7d453eee 2010
758cd94a 2011 If unsure, say N.
7d453eee 2012
4059ba65
AB
2013config EFI_FAKE_MEMMAP
2014 bool "Enable EFI fake memory map"
2015 depends on EFI
2016 help
2017 Saying Y here will enable "efi_fake_mem" boot option. By specifying
2018 this parameter, you can add arbitrary attribute to specific memory
2019 range by updating original (firmware provided) EFI memmap. This is
2020 useful for debugging of EFI memmap related feature, e.g., Address
2021 Range Mirroring feature.
2022
2023config EFI_MAX_FAKE_MEM
2024 int "maximum allowable number of ranges in efi_fake_mem boot option"
2025 depends on EFI_FAKE_MEMMAP
2026 range 1 128
2027 default 8
2028 help
2029 Maximum allowable number of ranges in efi_fake_mem boot option.
2030 Ranges can be set up to this value using comma-separated list.
2031 The default value is 8.
2032
1fff234d
AB
2033config EFI_RUNTIME_MAP
2034 bool "Export EFI runtime maps to sysfs" if EXPERT
2035 depends on EFI
2036 default KEXEC_CORE
2037 help
2038 Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2039 That memory map is required by the 2nd kernel to set up EFI virtual
2040 mappings after kexec, but can also be used for debugging purposes.
2041
2042 See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2043
8636a1f9 2044source "kernel/Kconfig.hz"
506f1d07
SR
2045
2046config KEXEC
2047 bool "kexec system call"
2965faa5 2048 select KEXEC_CORE
a7f7f624 2049 help
506f1d07
SR
2050 kexec is a system call that implements the ability to shutdown your
2051 current kernel, and to start another kernel. It is like a reboot
2052 but it is independent of the system firmware. And like a reboot
2053 you can start any kernel with it, not just Linux.
2054
2055 The name comes from the similarity to the exec system call.
2056
2057 It is an ongoing process to be certain the hardware in a machine
2058 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
2059 initially work for you. As of this writing the exact hardware
2060 interface is strongly in flux, so no good recommendation can be
2061 made.
506f1d07 2062
74ca317c
VG
2063config KEXEC_FILE
2064 bool "kexec file based system call"
2965faa5 2065 select KEXEC_CORE
b69a2afd 2066 select HAVE_IMA_KEXEC if IMA
74ca317c
VG
2067 depends on X86_64
2068 depends on CRYPTO=y
2069 depends on CRYPTO_SHA256=y
a7f7f624 2070 help
74ca317c
VG
2071 This is new version of kexec system call. This system call is
2072 file based and takes file descriptors as system call argument
2073 for kernel and initramfs as opposed to list of segments as
2074 accepted by previous system call.
2075
b799a09f
AT
2076config ARCH_HAS_KEXEC_PURGATORY
2077 def_bool KEXEC_FILE
2078
99d5cadf 2079config KEXEC_SIG
8e7d8381 2080 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2081 depends on KEXEC_FILE
a7f7f624 2082 help
d8eb8940 2083
99d5cadf
JB
2084 This option makes the kexec_file_load() syscall check for a valid
2085 signature of the kernel image. The image can still be loaded without
2086 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2087 there's a signature that we can check, then it must be valid.
2088
2089 In addition to this option, you need to enable signature
d8eb8940
BP
2090 verification for the corresponding kernel image type being
2091 loaded in order for this to work.
8e7d8381 2092
99d5cadf
JB
2093config KEXEC_SIG_FORCE
2094 bool "Require a valid signature in kexec_file_load() syscall"
2095 depends on KEXEC_SIG
a7f7f624 2096 help
99d5cadf
JB
2097 This option makes kernel signature verification mandatory for
2098 the kexec_file_load() syscall.
2099
8e7d8381
VG
2100config KEXEC_BZIMAGE_VERIFY_SIG
2101 bool "Enable bzImage signature verification support"
99d5cadf 2102 depends on KEXEC_SIG
8e7d8381
VG
2103 depends on SIGNED_PE_FILE_VERIFICATION
2104 select SYSTEM_TRUSTED_KEYRING
a7f7f624 2105 help
8e7d8381
VG
2106 Enable bzImage signature verification support.
2107
506f1d07 2108config CRASH_DUMP
04b69447 2109 bool "kernel crash dumps"
506f1d07 2110 depends on X86_64 || (X86_32 && HIGHMEM)
a7f7f624 2111 help
506f1d07
SR
2112 Generate crash dump after being started by kexec.
2113 This should be normally only set in special crash dump kernels
2114 which are loaded in the main kernel with kexec-tools into
2115 a specially reserved region and then later executed after
2116 a crash by kdump/kexec. The crash dump kernel must be compiled
2117 to a memory address not used by the main kernel or BIOS using
2118 PHYSICAL_START, or it must be built as a relocatable image
2119 (CONFIG_RELOCATABLE=y).
330d4810 2120 For more details see Documentation/admin-guide/kdump/kdump.rst
506f1d07 2121
3ab83521 2122config KEXEC_JUMP
6ea30386 2123 bool "kexec jump"
fee7b0d8 2124 depends on KEXEC && HIBERNATION
a7f7f624 2125 help
89081d17
HY
2126 Jump between original kernel and kexeced kernel and invoke
2127 code in physical address mode via KEXEC
3ab83521 2128
506f1d07 2129config PHYSICAL_START
6a108a14 2130 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2131 default "0x1000000"
a7f7f624 2132 help
506f1d07
SR
2133 This gives the physical address where the kernel is loaded.
2134
2135 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2136 bzImage will decompress itself to above physical address and
2137 run from there. Otherwise, bzImage will run from the address where
2138 it has been loaded by the boot loader and will ignore above physical
2139 address.
2140
2141 In normal kdump cases one does not have to set/change this option
2142 as now bzImage can be compiled as a completely relocatable image
2143 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2144 address. This option is mainly useful for the folks who don't want
2145 to use a bzImage for capturing the crash dump and want to use a
2146 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2147 to be specifically compiled to run from a specific memory area
2148 (normally a reserved region) and this option comes handy.
2149
ceefccc9
PA
2150 So if you are using bzImage for capturing the crash dump,
2151 leave the value here unchanged to 0x1000000 and set
2152 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2153 for capturing the crash dump change this value to start of
2154 the reserved region. In other words, it can be set based on
2155 the "X" value as specified in the "crashkernel=YM@XM"
2156 command line boot parameter passed to the panic-ed
330d4810 2157 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
ceefccc9 2158 for more details about crash dumps.
506f1d07
SR
2159
2160 Usage of bzImage for capturing the crash dump is recommended as
2161 one does not have to build two kernels. Same kernel can be used
2162 as production kernel and capture kernel. Above option should have
2163 gone away after relocatable bzImage support is introduced. But it
2164 is present because there are users out there who continue to use
2165 vmlinux for dump capture. This option should go away down the
2166 line.
2167
2168 Don't change this unless you know what you are doing.
2169
2170config RELOCATABLE
26717808
PA
2171 bool "Build a relocatable kernel"
2172 default y
a7f7f624 2173 help
506f1d07
SR
2174 This builds a kernel image that retains relocation information
2175 so it can be loaded someplace besides the default 1MB.
2176 The relocations tend to make the kernel binary about 10% larger,
2177 but are discarded at runtime.
2178
2179 One use is for the kexec on panic case where the recovery kernel
2180 must live at a different physical address than the primary
2181 kernel.
2182
2183 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2184 it has been loaded at and the compile time physical address
8ab3820f 2185 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2186
8ab3820f 2187config RANDOMIZE_BASE
e8581e3d 2188 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2189 depends on RELOCATABLE
6807c846 2190 default y
a7f7f624 2191 help
e8581e3d
BH
2192 In support of Kernel Address Space Layout Randomization (KASLR),
2193 this randomizes the physical address at which the kernel image
2194 is decompressed and the virtual address where the kernel
2195 image is mapped, as a security feature that deters exploit
2196 attempts relying on knowledge of the location of kernel
2197 code internals.
2198
ed9f007e
KC
2199 On 64-bit, the kernel physical and virtual addresses are
2200 randomized separately. The physical address will be anywhere
2201 between 16MB and the top of physical memory (up to 64TB). The
2202 virtual address will be randomized from 16MB up to 1GB (9 bits
2203 of entropy). Note that this also reduces the memory space
2204 available to kernel modules from 1.5GB to 1GB.
2205
2206 On 32-bit, the kernel physical and virtual addresses are
2207 randomized together. They will be randomized from 16MB up to
2208 512MB (8 bits of entropy).
e8581e3d
BH
2209
2210 Entropy is generated using the RDRAND instruction if it is
2211 supported. If RDTSC is supported, its value is mixed into
2212 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2213 supported, then entropy is read from the i8254 timer. The
2214 usable entropy is limited by the kernel being built using
2215 2GB addressing, and that PHYSICAL_ALIGN must be at a
2216 minimum of 2MB. As a result, only 10 bits of entropy are
2217 theoretically possible, but the implementations are further
2218 limited due to memory layouts.
e8581e3d 2219
6807c846 2220 If unsure, say Y.
8ab3820f
KC
2221
2222# Relocation on x86 needs some additional build support
845adf72
PA
2223config X86_NEED_RELOCS
2224 def_bool y
8ab3820f 2225 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2226
506f1d07 2227config PHYSICAL_ALIGN
a0215061 2228 hex "Alignment value to which kernel should be aligned"
8ab3820f 2229 default "0x200000"
a0215061
KC
2230 range 0x2000 0x1000000 if X86_32
2231 range 0x200000 0x1000000 if X86_64
a7f7f624 2232 help
506f1d07
SR
2233 This value puts the alignment restrictions on physical address
2234 where kernel is loaded and run from. Kernel is compiled for an
2235 address which meets above alignment restriction.
2236
2237 If bootloader loads the kernel at a non-aligned address and
2238 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2239 address aligned to above value and run from there.
2240
2241 If bootloader loads the kernel at a non-aligned address and
2242 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2243 load address and decompress itself to the address it has been
2244 compiled for and run from there. The address for which kernel is
2245 compiled already meets above alignment restrictions. Hence the
2246 end result is that kernel runs from a physical address meeting
2247 above alignment restrictions.
2248
a0215061
KC
2249 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2250 this value must be a multiple of 0x200000.
2251
506f1d07
SR
2252 Don't change this unless you know what you are doing.
2253
eedb92ab
KS
2254config DYNAMIC_MEMORY_LAYOUT
2255 bool
a7f7f624 2256 help
eedb92ab
KS
2257 This option makes base addresses of vmalloc and vmemmap as well as
2258 __PAGE_OFFSET movable during boot.
2259
0483e1fa
TG
2260config RANDOMIZE_MEMORY
2261 bool "Randomize the kernel memory sections"
2262 depends on X86_64
2263 depends on RANDOMIZE_BASE
eedb92ab 2264 select DYNAMIC_MEMORY_LAYOUT
0483e1fa 2265 default RANDOMIZE_BASE
a7f7f624 2266 help
758cd94a
JH
2267 Randomizes the base virtual address of kernel memory sections
2268 (physical memory mapping, vmalloc & vmemmap). This security feature
2269 makes exploits relying on predictable memory locations less reliable.
0483e1fa 2270
758cd94a
JH
2271 The order of allocations remains unchanged. Entropy is generated in
2272 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2273 configuration have in average 30,000 different possible virtual
2274 addresses for each memory section.
0483e1fa 2275
758cd94a 2276 If unsure, say Y.
0483e1fa 2277
90397a41
TG
2278config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2279 hex "Physical memory mapping padding" if EXPERT
2280 depends on RANDOMIZE_MEMORY
2281 default "0xa" if MEMORY_HOTPLUG
2282 default "0x0"
2283 range 0x1 0x40 if MEMORY_HOTPLUG
2284 range 0x0 0x40
a7f7f624 2285 help
758cd94a
JH
2286 Define the padding in terabytes added to the existing physical
2287 memory size during kernel memory randomization. It is useful
2288 for memory hotplug support but reduces the entropy available for
2289 address randomization.
90397a41 2290
758cd94a 2291 If unsure, leave at the default value.
90397a41 2292
6449dcb0
KS
2293config ADDRESS_MASKING
2294 bool "Linear Address Masking support"
2295 depends on X86_64
2296 help
2297 Linear Address Masking (LAM) modifies the checking that is applied
2298 to 64-bit linear addresses, allowing software to use of the
2299 untranslated address bits for metadata.
2300
2301 The capability can be used for efficient address sanitizers (ASAN)
2302 implementation and for optimizations in JITs.
2303
506f1d07 2304config HOTPLUG_CPU
bebd024e 2305 def_bool y
40b31360 2306 depends on SMP
506f1d07 2307
80aa1dff
FY
2308config BOOTPARAM_HOTPLUG_CPU0
2309 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2310 depends on HOTPLUG_CPU
a7f7f624 2311 help
80aa1dff
FY
2312 Set whether default state of cpu0_hotpluggable is on or off.
2313
2314 Say Y here to enable CPU0 hotplug by default. If this switch
2315 is turned on, there is no need to give cpu0_hotplug kernel
2316 parameter and the CPU0 hotplug feature is enabled by default.
2317
2318 Please note: there are two known CPU0 dependencies if you want
2319 to enable the CPU0 hotplug feature either by this switch or by
2320 cpu0_hotplug kernel parameter.
2321
2322 First, resume from hibernate or suspend always starts from CPU0.
2323 So hibernate and suspend are prevented if CPU0 is offline.
2324
2325 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2326 offline if any interrupt can not migrate out of CPU0. There may
2327 be other CPU0 dependencies.
2328
2329 Please make sure the dependencies are under your control before
2330 you enable this feature.
2331
2332 Say N if you don't want to enable CPU0 hotplug feature by default.
2333 You still can enable the CPU0 hotplug feature at boot by kernel
2334 parameter cpu0_hotplug.
2335
a71c8bc5
FY
2336config DEBUG_HOTPLUG_CPU0
2337 def_bool n
2338 prompt "Debug CPU0 hotplug"
2c922cd0 2339 depends on HOTPLUG_CPU
a7f7f624 2340 help
a71c8bc5
FY
2341 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2342 soon as possible and boots up userspace with CPU0 offlined. User
2343 can online CPU0 back after boot time.
2344
2345 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2346 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2347 compilation or giving cpu0_hotplug kernel parameter at boot.
2348
2349 If unsure, say N.
2350
506f1d07 2351config COMPAT_VDSO
b0b49f26
AL
2352 def_bool n
2353 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2354 depends on COMPAT_32
a7f7f624 2355 help
b0b49f26
AL
2356 Certain buggy versions of glibc will crash if they are
2357 presented with a 32-bit vDSO that is not mapped at the address
2358 indicated in its segment table.
e84446de 2359
b0b49f26
AL
2360 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2361 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2362 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2363 the only released version with the bug, but OpenSUSE 9
2364 contains a buggy "glibc 2.3.2".
506f1d07 2365
b0b49f26
AL
2366 The symptom of the bug is that everything crashes on startup, saying:
2367 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2368
2369 Saying Y here changes the default value of the vdso32 boot
2370 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2371 This works around the glibc bug but hurts performance.
2372
2373 If unsure, say N: if you are compiling your own kernel, you
2374 are unlikely to be using a buggy version of glibc.
506f1d07 2375
3dc33bd3
KC
2376choice
2377 prompt "vsyscall table for legacy applications"
2378 depends on X86_64
625b7b7f 2379 default LEGACY_VSYSCALL_XONLY
3dc33bd3
KC
2380 help
2381 Legacy user code that does not know how to find the vDSO expects
2382 to be able to issue three syscalls by calling fixed addresses in
2383 kernel space. Since this location is not randomized with ASLR,
2384 it can be used to assist security vulnerability exploitation.
2385
2386 This setting can be changed at boot time via the kernel command
bf00745e
AL
2387 line parameter vsyscall=[emulate|xonly|none]. Emulate mode
2388 is deprecated and can only be enabled using the kernel command
2389 line.
3dc33bd3
KC
2390
2391 On a system with recent enough glibc (2.14 or newer) and no
2392 static binaries, you can say None without a performance penalty
2393 to improve security.
2394
bd49e16e 2395 If unsure, select "Emulate execution only".
3dc33bd3 2396
bd49e16e
AL
2397 config LEGACY_VSYSCALL_XONLY
2398 bool "Emulate execution only"
2399 help
2400 The kernel traps and emulates calls into the fixed vsyscall
2401 address mapping and does not allow reads. This
2402 configuration is recommended when userspace might use the
2403 legacy vsyscall area but support for legacy binary
2404 instrumentation of legacy code is not needed. It mitigates
2405 certain uses of the vsyscall area as an ASLR-bypassing
2406 buffer.
3dc33bd3
KC
2407
2408 config LEGACY_VSYSCALL_NONE
2409 bool "None"
2410 help
2411 There will be no vsyscall mapping at all. This will
2412 eliminate any risk of ASLR bypass due to the vsyscall
2413 fixed address mapping. Attempts to use the vsyscalls
2414 will be reported to dmesg, so that either old or
2415 malicious userspace programs can be identified.
2416
2417endchoice
2418
516cbf37
TB
2419config CMDLINE_BOOL
2420 bool "Built-in kernel command line"
a7f7f624 2421 help
516cbf37
TB
2422 Allow for specifying boot arguments to the kernel at
2423 build time. On some systems (e.g. embedded ones), it is
2424 necessary or convenient to provide some or all of the
2425 kernel boot arguments with the kernel itself (that is,
2426 to not rely on the boot loader to provide them.)
2427
2428 To compile command line arguments into the kernel,
2429 set this option to 'Y', then fill in the
69711ca1 2430 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2431
2432 Systems with fully functional boot loaders (i.e. non-embedded)
2433 should leave this option set to 'N'.
2434
2435config CMDLINE
2436 string "Built-in kernel command string"
2437 depends on CMDLINE_BOOL
2438 default ""
a7f7f624 2439 help
516cbf37
TB
2440 Enter arguments here that should be compiled into the kernel
2441 image and used at boot time. If the boot loader provides a
2442 command line at boot time, it is appended to this string to
2443 form the full kernel command line, when the system boots.
2444
2445 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2446 change this behavior.
2447
2448 In most cases, the command line (whether built-in or provided
2449 by the boot loader) should specify the device for the root
2450 file system.
2451
2452config CMDLINE_OVERRIDE
2453 bool "Built-in command line overrides boot loader arguments"
645e6466 2454 depends on CMDLINE_BOOL && CMDLINE != ""
a7f7f624 2455 help
516cbf37
TB
2456 Set this option to 'Y' to have the kernel ignore the boot loader
2457 command line, and use ONLY the built-in command line.
2458
2459 This is used to work around broken boot loaders. This should
2460 be set to 'N' under normal conditions.
2461
a5b9e5a2
AL
2462config MODIFY_LDT_SYSCALL
2463 bool "Enable the LDT (local descriptor table)" if EXPERT
2464 default y
a7f7f624 2465 help
a5b9e5a2
AL
2466 Linux can allow user programs to install a per-process x86
2467 Local Descriptor Table (LDT) using the modify_ldt(2) system
2468 call. This is required to run 16-bit or segmented code such as
2469 DOSEMU or some Wine programs. It is also used by some very old
2470 threading libraries.
2471
2472 Enabling this feature adds a small amount of overhead to
2473 context switches and increases the low-level kernel attack
2474 surface. Disabling it removes the modify_ldt(2) system call.
2475
2476 Saying 'N' here may make sense for embedded or server kernels.
2477
3aac3ebe
TG
2478config STRICT_SIGALTSTACK_SIZE
2479 bool "Enforce strict size checking for sigaltstack"
2480 depends on DYNAMIC_SIGFRAME
2481 help
2482 For historical reasons MINSIGSTKSZ is a constant which became
2483 already too small with AVX512 support. Add a mechanism to
2484 enforce strict checking of the sigaltstack size against the
2485 real size of the FPU frame. This option enables the check
2486 by default. It can also be controlled via the kernel command
2487 line option 'strict_sas_size' independent of this config
2488 switch. Enabling it might break existing applications which
2489 allocate a too small sigaltstack but 'work' because they
2490 never get a signal delivered.
2491
2492 Say 'N' unless you want to really enforce this check.
2493
b700e7f0
SJ
2494source "kernel/livepatch/Kconfig"
2495
506f1d07
SR
2496endmenu
2497
f43b9876
PZ
2498config CC_HAS_SLS
2499 def_bool $(cc-option,-mharden-sls=all)
2500
2501config CC_HAS_RETURN_THUNK
2502 def_bool $(cc-option,-mfunction-return=thunk-extern)
2503
bea75b33
TG
2504config CC_HAS_ENTRY_PADDING
2505 def_bool $(cc-option,-fpatchable-function-entry=16,16)
2506
2507config FUNCTION_PADDING_CFI
2508 int
2509 default 59 if FUNCTION_ALIGNMENT_64B
2510 default 27 if FUNCTION_ALIGNMENT_32B
2511 default 11 if FUNCTION_ALIGNMENT_16B
2512 default 3 if FUNCTION_ALIGNMENT_8B
2513 default 0
2514
2515# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2516# except Kconfig can't do arithmetic :/
2517config FUNCTION_PADDING_BYTES
2518 int
2519 default FUNCTION_PADDING_CFI if CFI_CLANG
2520 default FUNCTION_ALIGNMENT
2521
931ab636
PZ
2522config CALL_PADDING
2523 def_bool n
2524 depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2525 select FUNCTION_ALIGNMENT_16B
2526
2527config FINEIBT
2528 def_bool y
2529 depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2530 select CALL_PADDING
2531
8f7c0d8b
TG
2532config HAVE_CALL_THUNKS
2533 def_bool y
bea75b33 2534 depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
8f7c0d8b
TG
2535
2536config CALL_THUNKS
2537 def_bool n
931ab636 2538 select CALL_PADDING
8f7c0d8b 2539
b341b20d
PZ
2540config PREFIX_SYMBOLS
2541 def_bool y
931ab636 2542 depends on CALL_PADDING && !CFI_CLANG
b341b20d 2543
f43b9876
PZ
2544menuconfig SPECULATION_MITIGATIONS
2545 bool "Mitigations for speculative execution vulnerabilities"
2546 default y
2547 help
2548 Say Y here to enable options which enable mitigations for
2549 speculative execution hardware vulnerabilities.
2550
2551 If you say N, all mitigations will be disabled. You really
2552 should know what you are doing to say so.
2553
2554if SPECULATION_MITIGATIONS
2555
2556config PAGE_TABLE_ISOLATION
2557 bool "Remove the kernel mapping in user mode"
2558 default y
2559 depends on (X86_64 || X86_PAE)
2560 help
2561 This feature reduces the number of hardware side channels by
2562 ensuring that the majority of kernel addresses are not mapped
2563 into userspace.
2564
ff61f079 2565 See Documentation/arch/x86/pti.rst for more details.
f43b9876
PZ
2566
2567config RETPOLINE
2568 bool "Avoid speculative indirect branches in kernel"
2569 select OBJTOOL if HAVE_OBJTOOL
2570 default y
2571 help
2572 Compile kernel with the retpoline compiler options to guard against
2573 kernel-to-user data leaks by avoiding speculative indirect
2574 branches. Requires a compiler with -mindirect-branch=thunk-extern
2575 support for full protection. The kernel may run slower.
2576
2577config RETHUNK
2578 bool "Enable return-thunks"
2579 depends on RETPOLINE && CC_HAS_RETURN_THUNK
2580 select OBJTOOL if HAVE_OBJTOOL
b648ab48 2581 default y if X86_64
f43b9876
PZ
2582 help
2583 Compile the kernel with the return-thunks compiler option to guard
2584 against kernel-to-user data leaks by avoiding return speculation.
2585 Requires a compiler with -mfunction-return=thunk-extern
2586 support for full protection. The kernel may run slower.
2587
2588config CPU_UNRET_ENTRY
2589 bool "Enable UNRET on kernel entry"
b648ab48 2590 depends on CPU_SUP_AMD && RETHUNK && X86_64
f43b9876
PZ
2591 default y
2592 help
2593 Compile the kernel with support for the retbleed=unret mitigation.
2594
80e4c1cd
TG
2595config CALL_DEPTH_TRACKING
2596 bool "Mitigate RSB underflow with call depth tracking"
2597 depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2598 select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2599 select CALL_THUNKS
2600 default y
2601 help
2602 Compile the kernel with call depth tracking to mitigate the Intel
2603 SKL Return-Speculation-Buffer (RSB) underflow issue. The
2604 mitigation is off by default and needs to be enabled on the
2605 kernel command line via the retbleed=stuff option. For
2606 non-affected systems the overhead of this option is marginal as
2607 the call depth tracking is using run-time generated call thunks
2608 in a compiler generated padding area and call patching. This
2609 increases text size by ~5%. For non affected systems this space
2610 is unused. On affected SKL systems this results in a significant
2611 performance gain over the IBRS mitigation.
2612
e81dc127
TG
2613config CALL_THUNKS_DEBUG
2614 bool "Enable call thunks and call depth tracking debugging"
2615 depends on CALL_DEPTH_TRACKING
2616 select FUNCTION_ALIGNMENT_32B
2617 default n
2618 help
2619 Enable call/ret counters for imbalance detection and build in
2620 a noisy dmesg about callthunks generation and call patching for
2621 trouble shooting. The debug prints need to be enabled on the
2622 kernel command line with 'debug-callthunks'.
54628de6
RD
2623 Only enable this when you are debugging call thunks as this
2624 creates a noticeable runtime overhead. If unsure say N.
80e4c1cd 2625
f43b9876
PZ
2626config CPU_IBPB_ENTRY
2627 bool "Enable IBPB on kernel entry"
b648ab48 2628 depends on CPU_SUP_AMD && X86_64
f43b9876
PZ
2629 default y
2630 help
2631 Compile the kernel with support for the retbleed=ibpb mitigation.
2632
2633config CPU_IBRS_ENTRY
2634 bool "Enable IBRS on kernel entry"
b648ab48 2635 depends on CPU_SUP_INTEL && X86_64
f43b9876
PZ
2636 default y
2637 help
2638 Compile the kernel with support for the spectre_v2=ibrs mitigation.
2639 This mitigates both spectre_v2 and retbleed at great cost to
2640 performance.
2641
2642config SLS
2643 bool "Mitigate Straight-Line-Speculation"
2644 depends on CC_HAS_SLS && X86_64
2645 select OBJTOOL if HAVE_OBJTOOL
2646 default n
2647 help
2648 Compile the kernel with straight-line-speculation options to guard
2649 against straight line speculation. The kernel image might be slightly
2650 larger.
2651
2652endif
2653
3072e413
MH
2654config ARCH_HAS_ADD_PAGES
2655 def_bool y
5c11f00b 2656 depends on ARCH_ENABLE_MEMORY_HOTPLUG
3072e413 2657
f91ef222
OS
2658config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2659 def_bool y
2660
da85f865 2661menu "Power management and ACPI options"
e279b6c1
SR
2662
2663config ARCH_HIBERNATION_HEADER
3c2362e6 2664 def_bool y
44556530 2665 depends on HIBERNATION
e279b6c1
SR
2666
2667source "kernel/power/Kconfig"
2668
2669source "drivers/acpi/Kconfig"
2670
a6b68076 2671config X86_APM_BOOT
6fc108a0 2672 def_bool y
282e5aab 2673 depends on APM
a6b68076 2674
e279b6c1
SR
2675menuconfig APM
2676 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2677 depends on X86_32 && PM_SLEEP
a7f7f624 2678 help
e279b6c1
SR
2679 APM is a BIOS specification for saving power using several different
2680 techniques. This is mostly useful for battery powered laptops with
2681 APM compliant BIOSes. If you say Y here, the system time will be
2682 reset after a RESUME operation, the /proc/apm device will provide
2683 battery status information, and user-space programs will receive
2684 notification of APM "events" (e.g. battery status change).
2685
2686 If you select "Y" here, you can disable actual use of the APM
2687 BIOS by passing the "apm=off" option to the kernel at boot time.
2688
2689 Note that the APM support is almost completely disabled for
2690 machines with more than one CPU.
2691
2692 In order to use APM, you will need supporting software. For location
151f4e2b 2693 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2694 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2695 <http://www.tldp.org/docs.html#howto>.
2696
2697 This driver does not spin down disk drives (see the hdparm(8)
2698 manpage ("man 8 hdparm") for that), and it doesn't turn off
2699 VESA-compliant "green" monitors.
2700
2701 This driver does not support the TI 4000M TravelMate and the ACER
2702 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2703 desktop machines also don't have compliant BIOSes, and this driver
2704 may cause those machines to panic during the boot phase.
2705
2706 Generally, if you don't have a battery in your machine, there isn't
2707 much point in using this driver and you should say N. If you get
2708 random kernel OOPSes or reboots that don't seem to be related to
2709 anything, try disabling/enabling this option (or disabling/enabling
2710 APM in your BIOS).
2711
2712 Some other things you should try when experiencing seemingly random,
2713 "weird" problems:
2714
2715 1) make sure that you have enough swap space and that it is
2716 enabled.
7987448f 2717 2) pass the "idle=poll" option to the kernel
e279b6c1
SR
2718 3) switch on floating point emulation in the kernel and pass
2719 the "no387" option to the kernel
2720 4) pass the "floppy=nodma" option to the kernel
2721 5) pass the "mem=4M" option to the kernel (thereby disabling
2722 all but the first 4 MB of RAM)
2723 6) make sure that the CPU is not over clocked.
2724 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2725 8) disable the cache from your BIOS settings
2726 9) install a fan for the video card or exchange video RAM
2727 10) install a better fan for the CPU
2728 11) exchange RAM chips
2729 12) exchange the motherboard.
2730
2731 To compile this driver as a module, choose M here: the
2732 module will be called apm.
2733
2734if APM
2735
2736config APM_IGNORE_USER_SUSPEND
2737 bool "Ignore USER SUSPEND"
a7f7f624 2738 help
e279b6c1
SR
2739 This option will ignore USER SUSPEND requests. On machines with a
2740 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2741 series notebooks, it is necessary to say Y because of a BIOS bug.
2742
2743config APM_DO_ENABLE
2744 bool "Enable PM at boot time"
a7f7f624 2745 help
e279b6c1
SR
2746 Enable APM features at boot time. From page 36 of the APM BIOS
2747 specification: "When disabled, the APM BIOS does not automatically
2748 power manage devices, enter the Standby State, enter the Suspend
2749 State, or take power saving steps in response to CPU Idle calls."
2750 This driver will make CPU Idle calls when Linux is idle (unless this
2751 feature is turned off -- see "Do CPU IDLE calls", below). This
2752 should always save battery power, but more complicated APM features
2753 will be dependent on your BIOS implementation. You may need to turn
2754 this option off if your computer hangs at boot time when using APM
2755 support, or if it beeps continuously instead of suspending. Turn
2756 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2757 T400CDT. This is off by default since most machines do fine without
2758 this feature.
2759
2760config APM_CPU_IDLE
dd8af076 2761 depends on CPU_IDLE
e279b6c1 2762 bool "Make CPU Idle calls when idle"
a7f7f624 2763 help
e279b6c1
SR
2764 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2765 On some machines, this can activate improved power savings, such as
2766 a slowed CPU clock rate, when the machine is idle. These idle calls
2767 are made after the idle loop has run for some length of time (e.g.,
2768 333 mS). On some machines, this will cause a hang at boot time or
2769 whenever the CPU becomes idle. (On machines with more than one CPU,
2770 this option does nothing.)
2771
2772config APM_DISPLAY_BLANK
2773 bool "Enable console blanking using APM"
a7f7f624 2774 help
e279b6c1
SR
2775 Enable console blanking using the APM. Some laptops can use this to
2776 turn off the LCD backlight when the screen blanker of the Linux
2777 virtual console blanks the screen. Note that this is only used by
2778 the virtual console screen blanker, and won't turn off the backlight
2779 when using the X Window system. This also doesn't have anything to
2780 do with your VESA-compliant power-saving monitor. Further, this
2781 option doesn't work for all laptops -- it might not turn off your
2782 backlight at all, or it might print a lot of errors to the console,
2783 especially if you are using gpm.
2784
2785config APM_ALLOW_INTS
2786 bool "Allow interrupts during APM BIOS calls"
a7f7f624 2787 help
e279b6c1
SR
2788 Normally we disable external interrupts while we are making calls to
2789 the APM BIOS as a measure to lessen the effects of a badly behaving
2790 BIOS implementation. The BIOS should reenable interrupts if it
2791 needs to. Unfortunately, some BIOSes do not -- especially those in
2792 many of the newer IBM Thinkpads. If you experience hangs when you
2793 suspend, try setting this to Y. Otherwise, say N.
2794
e279b6c1
SR
2795endif # APM
2796
bb0a56ec 2797source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2798
2799source "drivers/cpuidle/Kconfig"
2800
27471fdb
AH
2801source "drivers/idle/Kconfig"
2802
e279b6c1
SR
2803endmenu
2804
e279b6c1
SR
2805menu "Bus options (PCI etc.)"
2806
e279b6c1
SR
2807choice
2808 prompt "PCI access mode"
efefa6f6 2809 depends on X86_32 && PCI
e279b6c1 2810 default PCI_GOANY
a7f7f624 2811 help
e279b6c1
SR
2812 On PCI systems, the BIOS can be used to detect the PCI devices and
2813 determine their configuration. However, some old PCI motherboards
2814 have BIOS bugs and may crash if this is done. Also, some embedded
2815 PCI-based systems don't have any BIOS at all. Linux can also try to
2816 detect the PCI hardware directly without using the BIOS.
2817
2818 With this option, you can specify how Linux should detect the
2819 PCI devices. If you choose "BIOS", the BIOS will be used,
2820 if you choose "Direct", the BIOS won't be used, and if you
2821 choose "MMConfig", then PCI Express MMCONFIG will be used.
2822 If you choose "Any", the kernel will try MMCONFIG, then the
2823 direct access method and falls back to the BIOS if that doesn't
2824 work. If unsure, go with the default, which is "Any".
2825
2826config PCI_GOBIOS
2827 bool "BIOS"
2828
2829config PCI_GOMMCONFIG
2830 bool "MMConfig"
2831
2832config PCI_GODIRECT
2833 bool "Direct"
2834
3ef0e1f8 2835config PCI_GOOLPC
76fb6570 2836 bool "OLPC XO-1"
3ef0e1f8
AS
2837 depends on OLPC
2838
2bdd1b03
AS
2839config PCI_GOANY
2840 bool "Any"
2841
e279b6c1
SR
2842endchoice
2843
2844config PCI_BIOS
3c2362e6 2845 def_bool y
efefa6f6 2846 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2847
2848# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2849config PCI_DIRECT
3c2362e6 2850 def_bool y
0aba496f 2851 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2852
2853config PCI_MMCONFIG
b45c9f36
JK
2854 bool "Support mmconfig PCI config space access" if X86_64
2855 default y
4590d98f 2856 depends on PCI && (ACPI || JAILHOUSE_GUEST)
b45c9f36 2857 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2858
3ef0e1f8 2859config PCI_OLPC
2bdd1b03
AS
2860 def_bool y
2861 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2862
b5401a96
AN
2863config PCI_XEN
2864 def_bool y
2865 depends on PCI && XEN
b5401a96 2866
8364e1f8
JK
2867config MMCONF_FAM10H
2868 def_bool y
2869 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2870
3f6ea84a 2871config PCI_CNB20LE_QUIRK
6a108a14 2872 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2873 depends on PCI
3f6ea84a
IS
2874 help
2875 Read the PCI windows out of the CNB20LE host bridge. This allows
2876 PCI hotplug to work on systems with the CNB20LE chipset which do
2877 not have ACPI.
2878
64a5fed6
BH
2879 There's no public spec for this chipset, and this functionality
2880 is known to be incomplete.
2881
2882 You should say N unless you know you need this.
2883
3a495511 2884config ISA_BUS
17a2a129 2885 bool "ISA bus support on modern systems" if EXPERT
3a495511 2886 help
17a2a129
WBG
2887 Expose ISA bus device drivers and options available for selection and
2888 configuration. Enable this option if your target machine has an ISA
2889 bus. ISA is an older system, displaced by PCI and newer bus
2890 architectures -- if your target machine is modern, it probably does
2891 not have an ISA bus.
3a495511
WBG
2892
2893 If unsure, say N.
2894
1c00f016 2895# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2896config ISA_DMA_API
1c00f016
DR
2897 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2898 default y
2899 help
2900 Enables ISA-style DMA support for devices requiring such controllers.
2901 If unsure, say Y.
e279b6c1 2902
51e68d05
LT
2903if X86_32
2904
e279b6c1
SR
2905config ISA
2906 bool "ISA support"
a7f7f624 2907 help
e279b6c1
SR
2908 Find out whether you have ISA slots on your motherboard. ISA is the
2909 name of a bus system, i.e. the way the CPU talks to the other stuff
2910 inside your box. Other bus systems are PCI, EISA, MicroChannel
2911 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2912 newer boards don't support it. If you have ISA, say Y, otherwise N.
2913
e279b6c1
SR
2914config SCx200
2915 tristate "NatSemi SCx200 support"
a7f7f624 2916 help
e279b6c1
SR
2917 This provides basic support for National Semiconductor's
2918 (now AMD's) Geode processors. The driver probes for the
2919 PCI-IDs of several on-chip devices, so its a good dependency
2920 for other scx200_* drivers.
2921
2922 If compiled as a module, the driver is named scx200.
2923
2924config SCx200HR_TIMER
2925 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2926 depends on SCx200
e279b6c1 2927 default y
a7f7f624 2928 help
e279b6c1
SR
2929 This driver provides a clocksource built upon the on-chip
2930 27MHz high-resolution timer. Its also a workaround for
2931 NSC Geode SC-1100's buggy TSC, which loses time when the
2932 processor goes idle (as is done by the scheduler). The
2933 other workaround is idle=poll boot option.
2934
3ef0e1f8
AS
2935config OLPC
2936 bool "One Laptop Per Child support"
54008979 2937 depends on !X86_PAE
3c554946 2938 select GPIOLIB
dc3119e7 2939 select OF
45bb1674 2940 select OF_PROMTREE
b4e51854 2941 select IRQ_DOMAIN
0c3d931b 2942 select OLPC_EC
a7f7f624 2943 help
3ef0e1f8
AS
2944 Add support for detecting the unique features of the OLPC
2945 XO hardware.
2946
a3128588
DD
2947config OLPC_XO1_PM
2948 bool "OLPC XO-1 Power Management"
fa112cf1 2949 depends on OLPC && MFD_CS5535=y && PM_SLEEP
a7f7f624 2950 help
97c4cb71 2951 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2952
cfee9597
DD
2953config OLPC_XO1_RTC
2954 bool "OLPC XO-1 Real Time Clock"
2955 depends on OLPC_XO1_PM && RTC_DRV_CMOS
a7f7f624 2956 help
cfee9597
DD
2957 Add support for the XO-1 real time clock, which can be used as a
2958 programmable wakeup source.
2959
7feda8e9
DD
2960config OLPC_XO1_SCI
2961 bool "OLPC XO-1 SCI extras"
92e830f2 2962 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2963 depends on INPUT=y
d8d01a63 2964 select POWER_SUPPLY
a7f7f624 2965 help
7feda8e9 2966 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2967 - EC-driven system wakeups
7feda8e9 2968 - Power button
7bc74b3d 2969 - Ebook switch
2cf2baea 2970 - Lid switch
e1040ac6
DD
2971 - AC adapter status updates
2972 - Battery status updates
7feda8e9 2973
a0f30f59
DD
2974config OLPC_XO15_SCI
2975 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2976 depends on OLPC && ACPI
2977 select POWER_SUPPLY
a7f7f624 2978 help
a0f30f59
DD
2979 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2980 - EC-driven system wakeups
2981 - AC adapter status updates
2982 - Battery status updates
bf1ebf00 2983
d4f3e350
EW
2984config ALIX
2985 bool "PCEngines ALIX System Support (LED setup)"
2986 select GPIOLIB
a7f7f624 2987 help
d4f3e350
EW
2988 This option enables system support for the PCEngines ALIX.
2989 At present this just sets up LEDs for GPIO control on
2990 ALIX2/3/6 boards. However, other system specific setup should
2991 get added here.
2992
2993 Note: You must still enable the drivers for GPIO and LED support
2994 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2995
2996 Note: You have to set alix.force=1 for boards with Award BIOS.
2997
da4e3302
PP
2998config NET5501
2999 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
3000 select GPIOLIB
a7f7f624 3001 help
da4e3302
PP
3002 This option enables system support for the Soekris Engineering net5501.
3003
3197059a
PP
3004config GEOS
3005 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
3006 select GPIOLIB
3007 depends on DMI
a7f7f624 3008 help
3197059a
PP
3009 This option enables system support for the Traverse Technologies GEOS.
3010
7d029125
VD
3011config TS5500
3012 bool "Technologic Systems TS-5500 platform support"
3013 depends on MELAN
3014 select CHECK_SIGNATURE
3015 select NEW_LEDS
3016 select LEDS_CLASS
a7f7f624 3017 help
7d029125
VD
3018 This option enables system support for the Technologic Systems TS-5500.
3019
bc0120fd
SR
3020endif # X86_32
3021
23ac4ae8 3022config AMD_NB
e279b6c1 3023 def_bool y
0e152cd7 3024 depends on CPU_SUP_AMD && PCI
e279b6c1 3025
e279b6c1
SR
3026endmenu
3027
1572497c 3028menu "Binary Emulations"
e279b6c1
SR
3029
3030config IA32_EMULATION
3031 bool "IA32 Emulation"
3032 depends on X86_64
39f88911 3033 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 3034 select BINFMT_ELF
39f88911 3035 select COMPAT_OLD_SIGACTION
a7f7f624 3036 help
5fd92e65
L
3037 Include code to run legacy 32-bit programs under a
3038 64-bit kernel. You should likely turn this on, unless you're
3039 100% sure that you don't have any 32-bit programs left.
e279b6c1 3040
83a44a4f 3041config X86_X32_ABI
6ea30386 3042 bool "x32 ABI for 64-bit mode"
9b54050b 3043 depends on X86_64
aaeed6ec
NC
3044 # llvm-objcopy does not convert x86_64 .note.gnu.property or
3045 # compressed debug sections to x86_x32 properly:
3046 # https://github.com/ClangBuiltLinux/linux/issues/514
3047 # https://github.com/ClangBuiltLinux/linux/issues/1141
3048 depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
a7f7f624 3049 help
5fd92e65
L
3050 Include code to run binaries for the x32 native 32-bit ABI
3051 for 64-bit processors. An x32 process gets access to the
3052 full 64-bit register file and wide data path while leaving
3053 pointers at 32 bits for smaller memory footprint.
3054
953fee1d
IM
3055config COMPAT_32
3056 def_bool y
3057 depends on IA32_EMULATION || X86_32
3058 select HAVE_UID16
3059 select OLD_SIGSUSPEND3
3060
e279b6c1 3061config COMPAT
3c2362e6 3062 def_bool y
83a44a4f 3063 depends on IA32_EMULATION || X86_X32_ABI
e279b6c1
SR
3064
3065config COMPAT_FOR_U64_ALIGNMENT
3120e25e 3066 def_bool y
a9251280 3067 depends on COMPAT
ee009e4a 3068
e279b6c1
SR
3069endmenu
3070
e5beae16
KP
3071config HAVE_ATOMIC_IOMAP
3072 def_bool y
3073 depends on X86_32
3074
edf88417 3075source "arch/x86/kvm/Kconfig"
5e8ebd84
JD
3076
3077source "arch/x86/Kconfig.assembler"