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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"
8f9ca475 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
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
daa93fab
SR
21
22config X86_64
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JB
23 def_bool y
24 depends on 64BIT
d94e0685 25 # Options that are inherently 64-bit kernel only:
e1073d1e 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
d94e0685
IM
27 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
f616ab59 31 select NEED_DMA_MAP_STATE
09230cbc 32 select SWIOTLB
d94e0685 33 select X86_DEV_DMA_OPS
f8781c4a 34 select ARCH_HAS_SYSCALL_WRAPPER
1032c0ba 35
d94e0685
IM
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40# ported to 32-bit as well. )
41#
8d5fffb9 42config X86
3c2362e6 43 def_bool y
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IM
44 #
45 # Note: keep this list sorted alphabetically
46 #
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IM
47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
49 select ANON_INODES
50 select ARCH_CLOCKSOURCE_DATA
2a21ad57 51 select ARCH_CLOCKSOURCE_INIT
6471b825 52 select ARCH_DISCARD_MEMBLOCK
c763ea26 53 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 54 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 55 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 56 select ARCH_HAS_ELF_RANDOMIZE
72d93104 57 select ARCH_HAS_FAST_MULTIPLIER
316d097c 58 select ARCH_HAS_FILTER_PGPROT
6974f0c4 59 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 60 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 61 select ARCH_HAS_KCOV if X86_64
10bcc80e 62 select ARCH_HAS_MEMBARRIER_SYNC_CORE
c763ea26 63 select ARCH_HAS_PMEM_API if X86_64
3010a5ea 64 select ARCH_HAS_PTE_SPECIAL
39208aa7 65 select ARCH_HAS_REFCOUNT
0aed55af 66 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
092b31aa 67 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
d2852a22 68 select ARCH_HAS_SET_MEMORY
6471b825 69 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
70 select ARCH_HAS_STRICT_KERNEL_RWX
71 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 72 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
c6d30853 73 select ARCH_HAS_UBSAN_SANITIZE_ALL
65f7d049 74 select ARCH_HAS_ZONE_DEVICE if X86_64
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IM
75 select ARCH_HAVE_NMI_SAFE_CMPXCHG
76 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 77 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 78 select ARCH_MIGHT_HAVE_PC_SERIO
2c870e61 79 select ARCH_SUPPORTS_ACPI
6471b825 80 select ARCH_SUPPORTS_ATOMIC_RMW
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IM
81 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
82 select ARCH_USE_BUILTIN_BSWAP
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IM
83 select ARCH_USE_QUEUED_RWLOCKS
84 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 85 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 86 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
38d8b4e6 87 select ARCH_WANTS_THP_SWAP if X86_64
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IM
88 select BUILDTIME_EXTABLE_SORT
89 select CLKEVT_I8253
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IM
90 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
91 select CLOCKSOURCE_WATCHDOG
6471b825 92 select DCACHE_WORD_ACCESS
fec777c3 93 select DMA_DIRECT_OPS
45471cd9
LT
94 select EDAC_ATOMIC_SCRUB
95 select EDAC_SUPPORT
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IM
96 select GENERIC_CLOCKEVENTS
97 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
98 select GENERIC_CLOCKEVENTS_MIN_ADJUST
99 select GENERIC_CMOS_UPDATE
100 select GENERIC_CPU_AUTOPROBE
61dc0f55 101 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 102 select GENERIC_EARLY_IOREMAP
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IM
103 select GENERIC_FIND_FIRST_BIT
104 select GENERIC_IOMAP
c7d6c9dd 105 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 106 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 107 select GENERIC_IRQ_MIGRATION if SMP
6471b825 108 select GENERIC_IRQ_PROBE
c201c917 109 select GENERIC_IRQ_RESERVATION_MODE
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IM
110 select GENERIC_IRQ_SHOW
111 select GENERIC_PENDING_IRQ if SMP
112 select GENERIC_SMP_IDLE_THREAD
113 select GENERIC_STRNCPY_FROM_USER
114 select GENERIC_STRNLEN_USER
115 select GENERIC_TIME_VSYSCALL
7edaeb68 116 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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IM
117 select HAVE_ACPI_APEI if ACPI
118 select HAVE_ACPI_APEI_NMI if ACPI
119 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
120 select HAVE_ARCH_AUDITSYSCALL
121 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
122 select HAVE_ARCH_JUMP_LABEL
b34006c4 123 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 124 select HAVE_ARCH_KASAN if X86_64
6471b825 125 select HAVE_ARCH_KGDB
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DC
126 select HAVE_ARCH_MMAP_RND_BITS if MMU
127 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 128 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 129 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 130 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 131 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 132 select HAVE_ARCH_STACKLEAK
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IM
133 select HAVE_ARCH_TRACEHOOK
134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 136 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 137 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
138 select HAVE_CMPXCHG_DOUBLE
139 select HAVE_CMPXCHG_LOCAL
140 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 141 select HAVE_COPY_THREAD_TLS
cf4db259 142 select HAVE_C_RECORDMCOUNT
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IM
143 select HAVE_DEBUG_KMEMLEAK
144 select HAVE_DEBUG_STACKOVERFLOW
6471b825 145 select HAVE_DMA_CONTIGUOUS
677aa9f7 146 select HAVE_DYNAMIC_FTRACE
06aeaaea 147 select HAVE_DYNAMIC_FTRACE_WITH_REGS
03f5781b 148 select HAVE_EBPF_JIT
58340a07 149 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 150 select HAVE_EXIT_THREAD
644e0e8d 151 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 152 select HAVE_FTRACE_MCOUNT_RECORD
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IM
153 select HAVE_FUNCTION_GRAPH_TRACER
154 select HAVE_FUNCTION_TRACER
6b90bd4b 155 select HAVE_GCC_PLUGINS
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IM
156 select HAVE_HW_BREAKPOINT
157 select HAVE_IDE
158 select HAVE_IOREMAP_PROT
159 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
160 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 161 select HAVE_KERNEL_BZIP2
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IM
162 select HAVE_KERNEL_GZIP
163 select HAVE_KERNEL_LZ4
2e9f3bdd 164 select HAVE_KERNEL_LZMA
13510997 165 select HAVE_KERNEL_LZO
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IM
166 select HAVE_KERNEL_XZ
167 select HAVE_KPROBES
168 select HAVE_KPROBES_ON_FTRACE
540adea3 169 select HAVE_FUNCTION_ERROR_INJECTION
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IM
170 select HAVE_KRETPROBES
171 select HAVE_KVM
172 select HAVE_LIVEPATCH if X86_64
6471b825 173 select HAVE_MEMBLOCK_NODE_MAP
0102752e 174 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 175 select HAVE_MOD_ARCH_SPECIFIC
42a0bb3f 176 select HAVE_NMI
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IM
177 select HAVE_OPROFILE
178 select HAVE_OPTPROBES
179 select HAVE_PCSPKR_PLATFORM
180 select HAVE_PERF_EVENTS
c01d4323 181 select HAVE_PERF_EVENTS_NMI
92e5aae4 182 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
c5e63197 183 select HAVE_PERF_REGS
c5ebcedb 184 select HAVE_PERF_USER_STACK_DUMP
48a8b97c 185 select HAVE_RCU_TABLE_FREE if PARAVIRT
d86564a2 186 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE
6471b825 187 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 188 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 189 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 190 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 191 select HAVE_STACK_VALIDATION if X86_64
d6761b8f 192 select HAVE_RSEQ
6471b825 193 select HAVE_SYSCALL_TRACEPOINTS
6471b825 194 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 195 select HAVE_USER_RETURN_NOTIFIER
05736e4a 196 select HOTPLUG_SMT if SMP
c0185808 197 select IRQ_FORCED_THREADING
86596f0a 198 select NEED_SG_DMA_LENGTH
df65c1bc 199 select PCI_LOCKLESS_CONFIG
6471b825 200 select PERF_EVENTS
3195ef59 201 select RTC_LIB
d6faca40 202 select RTC_MC146818_LIB
6471b825 203 select SPARSE_IRQ
83fe27ea 204 select SRCU
6471b825 205 select SYSCTL_EXCEPTION_TRACE
15f4eae7 206 select THREAD_INFO_IN_TASK
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IM
207 select USER_STACKTRACE_SUPPORT
208 select VIRT_TO_BUS
6471b825 209 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 210
ba7e4d13 211config INSTRUCTION_DECODER
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JB
212 def_bool y
213 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 214
51b26ada
LT
215config OUTPUT_FORMAT
216 string
217 default "elf32-i386" if X86_32
218 default "elf64-x86-64" if X86_64
219
73531905 220config ARCH_DEFCONFIG
b9b39bfb 221 string
73531905
SR
222 default "arch/x86/configs/i386_defconfig" if X86_32
223 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 224
8d5fffb9 225config LOCKDEP_SUPPORT
3c2362e6 226 def_bool y
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SR
227
228config STACKTRACE_SUPPORT
3c2362e6 229 def_bool y
8d5fffb9 230
8d5fffb9 231config MMU
3c2362e6 232 def_bool y
8d5fffb9 233
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DC
234config ARCH_MMAP_RND_BITS_MIN
235 default 28 if 64BIT
236 default 8
237
238config ARCH_MMAP_RND_BITS_MAX
239 default 32 if 64BIT
240 default 16
241
242config ARCH_MMAP_RND_COMPAT_BITS_MIN
243 default 8
244
245config ARCH_MMAP_RND_COMPAT_BITS_MAX
246 default 16
247
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SR
248config SBUS
249 bool
250
251config GENERIC_ISA_DMA
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JB
252 def_bool y
253 depends on ISA_DMA_API
8d5fffb9 254
8d5fffb9 255config GENERIC_BUG
3c2362e6 256 def_bool y
8d5fffb9 257 depends on BUG
b93a531e
JB
258 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
259
260config GENERIC_BUG_RELATIVE_POINTERS
261 bool
8d5fffb9
SR
262
263config GENERIC_HWEIGHT
3c2362e6 264 def_bool y
8d5fffb9
SR
265
266config ARCH_MAY_HAVE_PC_FDC
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JB
267 def_bool y
268 depends on ISA_DMA_API
8d5fffb9 269
1032c0ba 270config RWSEM_XCHGADD_ALGORITHM
3120e25e 271 def_bool y
1032c0ba 272
1032c0ba
SR
273config GENERIC_CALIBRATE_DELAY
274 def_bool y
275
9a0b8415 276config ARCH_HAS_CPU_RELAX
277 def_bool y
278
1b27d05b
PE
279config ARCH_HAS_CACHE_LINE_SIZE
280 def_bool y
281
316d097c
DH
282config ARCH_HAS_FILTER_PGPROT
283 def_bool y
284
dd5af90a 285config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 286 def_bool y
b32ef636 287
08fc4580
TH
288config NEED_PER_CPU_EMBED_FIRST_CHUNK
289 def_bool y
290
291config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
292 def_bool y
293
801e4062
JB
294config ARCH_HIBERNATION_POSSIBLE
295 def_bool y
801e4062 296
f4cb5700
JB
297config ARCH_SUSPEND_POSSIBLE
298 def_bool y
f4cb5700 299
cfe28c5d
SC
300config ARCH_WANT_HUGE_PMD_SHARE
301 def_bool y
302
53313b2c
SC
303config ARCH_WANT_GENERAL_HUGETLB
304 def_bool y
305
8d5fffb9 306config ZONE_DMA32
e0fd24a3 307 def_bool y if X86_64
8d5fffb9 308
8d5fffb9 309config AUDIT_ARCH
e0fd24a3 310 def_bool y if X86_64
8d5fffb9 311
765c68bd
IM
312config ARCH_SUPPORTS_OPTIMIZED_INLINING
313 def_bool y
314
6a11f75b
AM
315config ARCH_SUPPORTS_DEBUG_PAGEALLOC
316 def_bool y
317
d6f2d75a
AR
318config KASAN_SHADOW_OFFSET
319 hex
320 depends on KASAN
321 default 0xdffffc0000000000
322
69575d38
SW
323config HAVE_INTEL_TXT
324 def_bool y
6ea30386 325 depends on INTEL_IOMMU && ACPI
69575d38 326
6b0c3d44
SR
327config X86_32_SMP
328 def_bool y
329 depends on X86_32 && SMP
330
331config X86_64_SMP
332 def_bool y
333 depends on X86_64 && SMP
334
ccbeed3a
TH
335config X86_32_LAZY_GS
336 def_bool y
8458f8c2 337 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 338
2b144498
SD
339config ARCH_SUPPORTS_UPROBES
340 def_bool y
341
d20642f0
RH
342config FIX_EARLYCON_MEM
343 def_bool y
344
94d49eb3
KS
345config DYNAMIC_PHYSICAL_MASK
346 bool
347
98233368
KS
348config PGTABLE_LEVELS
349 int
77ef56e4 350 default 5 if X86_5LEVEL
98233368
KS
351 default 4 if X86_64
352 default 3 if X86_PAE
353 default 2
354
2a61f474
MY
355config CC_HAS_SANE_STACKPROTECTOR
356 bool
357 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
358 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
359 help
360 We have to make sure stack protector is unconditionally disabled if
361 the compiler produces broken code.
362
506f1d07
SR
363menu "Processor type and features"
364
5ee71535
RD
365config ZONE_DMA
366 bool "DMA memory allocation support" if EXPERT
367 default y
368 help
369 DMA memory allocation support allows devices with less than 32-bit
370 addressing to allocate within the first 16MB of address space.
371 Disable if no such devices will be used.
372
373 If unsure, say Y.
374
506f1d07
SR
375config SMP
376 bool "Symmetric multi-processing support"
377 ---help---
378 This enables support for systems with more than one CPU. If you have
4a474157
RG
379 a system with only one CPU, say N. If you have a system with more
380 than one CPU, say Y.
506f1d07 381
4a474157 382 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
383 machines, but will use only one CPU of a multiprocessor machine. If
384 you say Y here, the kernel will run on many, but not all,
4a474157 385 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
386 will run faster if you say N here.
387
388 Note that if you say Y here and choose architecture "586" or
389 "Pentium" under "Processor family", the kernel will not work on 486
390 architectures. Similarly, multiprocessor kernels for the "PPro"
391 architecture may not work on all Pentium based boards.
392
393 People using multiprocessor machines who say Y here should also say
394 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
395 Management" code will be disabled if you say Y here.
396
395cf969 397 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 398 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
506f1d07
SR
399 <http://www.tldp.org/docs.html#howto>.
400
401 If you don't know what to do here, say N.
402
9def39be
JT
403config X86_FEATURE_NAMES
404 bool "Processor feature human-readable names" if EMBEDDED
405 default y
406 ---help---
407 This option compiles in a table of x86 feature bits and corresponding
408 names. This is required to support /proc/cpuinfo and a few kernel
409 messages. You can disable this to save space, at the expense of
410 making those few kernel messages show numeric feature bits instead.
411
412 If in doubt, say Y.
413
06cd9a7d
YL
414config X86_X2APIC
415 bool "Support x2apic"
19e3d60d 416 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
417 ---help---
418 This enables x2apic support on CPUs that have this feature.
419
420 This allows 32-bit apic IDs (so it can support very large systems),
421 and accesses the local apic via MSRs not via mmio.
422
06cd9a7d
YL
423 If you don't know what to do here, say N.
424
6695c85b 425config X86_MPPARSE
6e87f9b7 426 bool "Enable MPS table" if ACPI || SFI
7a527688 427 default y
5ab74722 428 depends on X86_LOCAL_APIC
8f9ca475 429 ---help---
6695c85b
YL
430 For old smp systems that do not have proper acpi support. Newer systems
431 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 432
ddd70cf9
JN
433config GOLDFISH
434 def_bool y
435 depends on X86_GOLDFISH
436
76b04384
DW
437config RETPOLINE
438 bool "Avoid speculative indirect branches in kernel"
439 default y
d5028ba8 440 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
441 help
442 Compile kernel with the retpoline compiler options to guard against
443 kernel-to-user data leaks by avoiding speculative indirect
444 branches. Requires a compiler with -mindirect-branch=thunk-extern
445 support for full protection. The kernel may run slower.
446
f01d7d51
VS
447config INTEL_RDT
448 bool "Intel Resource Director Technology support"
78e99b4a 449 depends on X86 && CPU_SUP_INTEL
59fe5a77 450 select KERNFS
78e99b4a 451 help
f01d7d51
VS
452 Select to enable resource allocation and monitoring which are
453 sub-features of Intel Resource Director Technology(RDT). More
454 information about RDT can be found in the Intel x86
455 Architecture Software Developer Manual.
78e99b4a
FY
456
457 Say N if unsure.
458
8425091f 459if X86_32
a0d0bb4d
RD
460config X86_BIGSMP
461 bool "Support for big SMP systems with more than 8 CPUs"
462 depends on SMP
463 ---help---
464 This option is needed for the systems that have more than 8 CPUs
465
c5c606d9
RT
466config X86_EXTENDED_PLATFORM
467 bool "Support for extended (non-PC) x86 platforms"
468 default y
8f9ca475 469 ---help---
06ac8346
IM
470 If you disable this option then the kernel will only support
471 standard PC platforms. (which covers the vast majority of
472 systems out there.)
473
8425091f
RT
474 If you enable this option then you'll be able to select support
475 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 476 Goldfish (Android emulator)
8425091f 477 AMD Elan
8425091f
RT
478 RDC R-321x SoC
479 SGI 320/540 (Visual Workstation)
83125a3a 480 STA2X11-based (e.g. Northville)
3f4110a4 481 Moorestown MID devices
06ac8346
IM
482
483 If you have one of these systems, or if you want to build a
484 generic distribution kernel, say Y here - otherwise say N.
8425091f 485endif
06ac8346 486
8425091f
RT
487if X86_64
488config X86_EXTENDED_PLATFORM
489 bool "Support for extended (non-PC) x86 platforms"
490 default y
491 ---help---
492 If you disable this option then the kernel will only support
493 standard PC platforms. (which covers the vast majority of
494 systems out there.)
495
496 If you enable this option then you'll be able to select support
497 for the following (non-PC) 64 bit x86 platforms:
44b111b5 498 Numascale NumaChip
8425091f
RT
499 ScaleMP vSMP
500 SGI Ultraviolet
501
502 If you have one of these systems, or if you want to build a
503 generic distribution kernel, say Y here - otherwise say N.
504endif
c5c606d9
RT
505# This is an alphabetically sorted list of 64 bit extended platforms
506# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
507config X86_NUMACHIP
508 bool "Numascale NumaChip"
509 depends on X86_64
510 depends on X86_EXTENDED_PLATFORM
511 depends on NUMA
512 depends on SMP
513 depends on X86_X2APIC
f9726bfd 514 depends on PCI_MMCONFIG
44b111b5
SP
515 ---help---
516 Adds support for Numascale NumaChip large-SMP systems. Needed to
517 enable more than ~168 cores.
518 If you don't have one of these, you should say N here.
506f1d07 519
c5c606d9
RT
520config X86_VSMP
521 bool "ScaleMP vSMP"
6276a074 522 select HYPERVISOR_GUEST
c5c606d9
RT
523 select PARAVIRT
524 depends on X86_64 && PCI
525 depends on X86_EXTENDED_PLATFORM
ead91d4b 526 depends on SMP
8f9ca475 527 ---help---
c5c606d9
RT
528 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
529 supposed to run on these EM64T-based machines. Only choose this option
530 if you have one of these machines.
5e3a77e9 531
03b48632
NP
532config X86_UV
533 bool "SGI Ultraviolet"
534 depends on X86_64
c5c606d9 535 depends on X86_EXTENDED_PLATFORM
54c28d29 536 depends on NUMA
1ecb4ae5 537 depends on EFI
9d6c26e7 538 depends on X86_X2APIC
1222e564 539 depends on PCI
8f9ca475 540 ---help---
03b48632
NP
541 This option is needed in order to support SGI Ultraviolet systems.
542 If you don't have one of these, you should say N here.
543
c5c606d9
RT
544# Following is an alphabetically sorted list of 32 bit extended platforms
545# Please maintain the alphabetic order if and when there are additions
506f1d07 546
ddd70cf9
JN
547config X86_GOLDFISH
548 bool "Goldfish (Virtual Platform)"
cb7b8023 549 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
550 ---help---
551 Enable support for the Goldfish virtual platform used primarily
552 for Android development. Unless you are building for the Android
553 Goldfish emulator say N here.
554
c751e17b
TG
555config X86_INTEL_CE
556 bool "CE4100 TV platform"
557 depends on PCI
558 depends on PCI_GODIRECT
6084a6e2 559 depends on X86_IO_APIC
c751e17b
TG
560 depends on X86_32
561 depends on X86_EXTENDED_PLATFORM
37bc9f50 562 select X86_REBOOTFIXUPS
da6b737b
SAS
563 select OF
564 select OF_EARLY_FLATTREE
c751e17b
TG
565 ---help---
566 Select for the Intel CE media processor (CE4100) SOC.
567 This option compiles in support for the CE4100 SOC for settop
568 boxes and media devices.
569
4cb9b00f 570config X86_INTEL_MID
43605ef1 571 bool "Intel MID platform support"
43605ef1 572 depends on X86_EXTENDED_PLATFORM
edc6bc78 573 depends on X86_PLATFORM_DEVICES
1ea7c673 574 depends on PCI
3fda5bb4 575 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 576 depends on X86_IO_APIC
7c9c3a1e 577 select SFI
4cb9b00f 578 select I2C
7c9c3a1e 579 select DW_APB_TIMER
1ea7c673 580 select APB_TIMER
1ea7c673 581 select INTEL_SCU_IPC
15a713df 582 select MFD_INTEL_MSIC
1ea7c673 583 ---help---
4cb9b00f
DC
584 Select to build a kernel capable of supporting Intel MID (Mobile
585 Internet Device) platform systems which do not have the PCI legacy
586 interfaces. If you are building for a PC class system say N here.
1ea7c673 587
4cb9b00f
DC
588 Intel MID platforms are based on an Intel processor and chipset which
589 consume less power than most of the x86 derivatives.
43605ef1 590
8bbc2a13
BD
591config X86_INTEL_QUARK
592 bool "Intel Quark platform support"
593 depends on X86_32
594 depends on X86_EXTENDED_PLATFORM
595 depends on X86_PLATFORM_DEVICES
596 depends on X86_TSC
597 depends on PCI
598 depends on PCI_GOANY
599 depends on X86_IO_APIC
600 select IOSF_MBI
601 select INTEL_IMR
9ab6eb51 602 select COMMON_CLK
8bbc2a13
BD
603 ---help---
604 Select to include support for Quark X1000 SoC.
605 Say Y here if you have a Quark based system such as the Arduino
606 compatible Intel Galileo.
607
3d48aab1
MW
608config X86_INTEL_LPSS
609 bool "Intel Low Power Subsystem Support"
eebb3e8d 610 depends on X86 && ACPI
3d48aab1 611 select COMMON_CLK
0f531431 612 select PINCTRL
eebb3e8d 613 select IOSF_MBI
3d48aab1
MW
614 ---help---
615 Select to build support for Intel Low Power Subsystem such as
616 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
617 things like clock tree (common clock framework) and pincontrol
618 which are needed by the LPSS peripheral drivers.
3d48aab1 619
92082a88
KX
620config X86_AMD_PLATFORM_DEVICE
621 bool "AMD ACPI2Platform devices support"
622 depends on ACPI
623 select COMMON_CLK
624 select PINCTRL
625 ---help---
626 Select to interpret AMD specific ACPI device to platform device
627 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
628 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
629 implemented under PINCTRL subsystem.
630
ced3ce76
DB
631config IOSF_MBI
632 tristate "Intel SoC IOSF Sideband support for SoC platforms"
633 depends on PCI
634 ---help---
635 This option enables sideband register access support for Intel SoC
636 platforms. On these platforms the IOSF sideband is used in lieu of
637 MSR's for some register accesses, mostly but not limited to thermal
638 and power. Drivers may query the availability of this device to
639 determine if they need the sideband in order to work on these
640 platforms. The sideband is available on the following SoC products.
641 This list is not meant to be exclusive.
642 - BayTrail
643 - Braswell
644 - Quark
645
646 You should say Y if you are running a kernel on one of these SoC's.
647
ed2226bd
DB
648config IOSF_MBI_DEBUG
649 bool "Enable IOSF sideband access through debugfs"
650 depends on IOSF_MBI && DEBUG_FS
651 ---help---
652 Select this option to expose the IOSF sideband access registers (MCR,
653 MDR, MCRX) through debugfs to write and read register information from
654 different units on the SoC. This is most useful for obtaining device
655 state information for debug and analysis. As this is a general access
656 mechanism, users of this option would have specific knowledge of the
657 device they want to access.
658
659 If you don't require the option or are in doubt, say N.
660
c5c606d9
RT
661config X86_RDC321X
662 bool "RDC R-321x SoC"
506f1d07 663 depends on X86_32
c5c606d9
RT
664 depends on X86_EXTENDED_PLATFORM
665 select M486
666 select X86_REBOOTFIXUPS
667 ---help---
668 This option is needed for RDC R-321x system-on-chip, also known
669 as R-8610-(G).
670 If you don't have one of these chips, you should say N here.
671
e0c7ae37 672config X86_32_NON_STANDARD
9c398017
IM
673 bool "Support non-standard 32-bit SMP architectures"
674 depends on X86_32 && SMP
c5c606d9 675 depends on X86_EXTENDED_PLATFORM
8f9ca475 676 ---help---
b5660ba7
PA
677 This option compiles in the bigsmp and STA2X11 default
678 subarchitectures. It is intended for a generic binary
679 kernel. If you select them all, kernel will probe it one by
680 one and will fallback to default.
d49c4288 681
c5c606d9 682# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 683
d949f36f 684config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 685 def_bool y
d949f36f
LT
686 # MCE code calls memory_failure():
687 depends on X86_MCE
688 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
689 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
690 depends on X86_64 || !SPARSEMEM
691 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 692
83125a3a
AR
693config STA2X11
694 bool "STA2X11 Companion Chip Support"
695 depends on X86_32_NON_STANDARD && PCI
b6e05477 696 select ARCH_HAS_PHYS_TO_DMA
83125a3a
AR
697 select X86_DEV_DMA_OPS
698 select X86_DMA_REMAP
699 select SWIOTLB
700 select MFD_STA2X11
0145071b 701 select GPIOLIB
83125a3a
AR
702 ---help---
703 This adds support for boards based on the STA2X11 IO-Hub,
704 a.k.a. "ConneXt". The chip is used in place of the standard
705 PC chipset, so all "standard" peripherals are missing. If this
706 option is selected the kernel will still be able to boot on
707 standard PC machines.
708
82148d1d
S
709config X86_32_IRIS
710 tristate "Eurobraille/Iris poweroff module"
711 depends on X86_32
712 ---help---
713 The Iris machines from EuroBraille do not have APM or ACPI support
714 to shut themselves down properly. A special I/O sequence is
715 needed to do so, which is what this module does at
716 kernel shutdown.
717
718 This is only for Iris machines from EuroBraille.
719
720 If unused, say N.
721
ae1e9130 722config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
723 def_bool y
724 prompt "Single-depth WCHAN output"
a87d0914 725 depends on X86
8f9ca475 726 ---help---
506f1d07
SR
727 Calculate simpler /proc/<PID>/wchan values. If this option
728 is disabled then wchan values will recurse back to the
729 caller function. This provides more accurate wchan values,
730 at the expense of slightly more scheduling overhead.
731
732 If in doubt, say "Y".
733
6276a074
BP
734menuconfig HYPERVISOR_GUEST
735 bool "Linux guest support"
8f9ca475 736 ---help---
6276a074
BP
737 Say Y here to enable options for running Linux under various hyper-
738 visors. This option enables basic hypervisor detection and platform
739 setup.
506f1d07 740
6276a074
BP
741 If you say N, all options in this submenu will be skipped and
742 disabled, and Linux guest support won't be built in.
506f1d07 743
6276a074 744if HYPERVISOR_GUEST
506f1d07 745
e61bd94a
EPH
746config PARAVIRT
747 bool "Enable paravirtualization code"
8f9ca475 748 ---help---
e61bd94a
EPH
749 This changes the kernel so it can modify itself when it is run
750 under a hypervisor, potentially improving performance significantly
751 over full virtualization. However, when run without a hypervisor
752 the kernel is theoretically slower and slightly larger.
753
c00a280a
JG
754config PARAVIRT_XXL
755 bool
756
6276a074
BP
757config PARAVIRT_DEBUG
758 bool "paravirt-ops debugging"
759 depends on PARAVIRT && DEBUG_KERNEL
760 ---help---
761 Enable to debug paravirt_ops internals. Specifically, BUG if
762 a paravirt_op is missing when it is called.
763
b4ecc126
JF
764config PARAVIRT_SPINLOCKS
765 bool "Paravirtualization layer for spinlocks"
6ea30386 766 depends on PARAVIRT && SMP
b4ecc126
JF
767 ---help---
768 Paravirtualized spinlocks allow a pvops backend to replace the
769 spinlock implementation with something virtualization-friendly
770 (for example, block the virtual CPU rather than spinning).
771
4c4e4f61
R
772 It has a minimal impact on native kernels and gives a nice performance
773 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 774
4c4e4f61 775 If you are unsure how to answer this question, answer Y.
b4ecc126 776
45e898b7
WL
777config QUEUED_LOCK_STAT
778 bool "Paravirt queued spinlock statistics"
cfd8983f 779 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
780 ---help---
781 Enable the collection of statistical data on the slowpath
782 behavior of paravirtualized queued spinlocks and report
783 them on debugfs.
784
6276a074 785source "arch/x86/xen/Kconfig"
7af192c9 786
6276a074
BP
787config KVM_GUEST
788 bool "KVM Guest support (including kvmclock)"
789 depends on PARAVIRT
790 select PARAVIRT_CLOCK
791 default y
8f9ca475 792 ---help---
6276a074
BP
793 This option enables various optimizations for running under the KVM
794 hypervisor. It includes a paravirtualized clock, so that instead
795 of relying on a PIT (or probably other) emulation by the
796 underlying device model, the host provides the guest with
797 timing infrastructure such as time of day, and system time
506f1d07 798
1e20eb85
SV
799config KVM_DEBUG_FS
800 bool "Enable debug information for KVM Guests in debugfs"
801 depends on KVM_GUEST && DEBUG_FS
1e20eb85
SV
802 ---help---
803 This option enables collection of various statistics for KVM guest.
804 Statistics are displayed in debugfs filesystem. Enabling this option
805 may incur significant overhead.
806
6276a074
BP
807config PARAVIRT_TIME_ACCOUNTING
808 bool "Paravirtual steal time accounting"
809 depends on PARAVIRT
8f9ca475 810 ---help---
6276a074
BP
811 Select this option to enable fine granularity task steal time
812 accounting. Time spent executing other tasks in parallel with
813 the current vCPU is discounted from the vCPU power. To account for
814 that, there can be a small performance impact.
815
816 If in doubt, say N here.
817
818config PARAVIRT_CLOCK
819 bool
97349135 820
4a362601
JK
821config JAILHOUSE_GUEST
822 bool "Jailhouse non-root cell support"
abde587b 823 depends on X86_64 && PCI
87e65d05 824 select X86_PM_TIMER
4a362601
JK
825 ---help---
826 This option allows to run Linux as guest in a Jailhouse non-root
827 cell. You can leave this option disabled if you only want to start
828 Jailhouse and run Linux afterwards in the root cell.
829
6276a074 830endif #HYPERVISOR_GUEST
97349135 831
506f1d07
SR
832source "arch/x86/Kconfig.cpu"
833
834config HPET_TIMER
3c2362e6 835 def_bool X86_64
506f1d07 836 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
837 ---help---
838 Use the IA-PC HPET (High Precision Event Timer) to manage
839 time in preference to the PIT and RTC, if a HPET is
840 present.
841 HPET is the next generation timer replacing legacy 8254s.
842 The HPET provides a stable time base on SMP
843 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
844 as it is off-chip. The interface used is documented
845 in the HPET spec, revision 1.
506f1d07 846
8f9ca475
IM
847 You can safely choose Y here. However, HPET will only be
848 activated if the platform and the BIOS support this feature.
849 Otherwise the 8254 will be used for timing services.
506f1d07 850
8f9ca475 851 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
852
853config HPET_EMULATE_RTC
3c2362e6 854 def_bool y
9d8af78b 855 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 856
bb24c471 857config APB_TIMER
933b9463
AC
858 def_bool y if X86_INTEL_MID
859 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 860 select DW_APB_TIMER
a0c3832a 861 depends on X86_INTEL_MID && SFI
bb24c471
JP
862 help
863 APB timer is the replacement for 8254, HPET on X86 MID platforms.
864 The APBT provides a stable time base on SMP
865 systems, unlike the TSC, but it is more expensive to access,
866 as it is off-chip. APB timers are always running regardless of CPU
867 C states, they are used as per CPU clockevent device when possible.
868
6a108a14 869# Mark as expert because too many people got it wrong.
506f1d07 870# The code disables itself when not needed.
7ae9392c
TP
871config DMI
872 default y
cf074402 873 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 874 bool "Enable DMI scanning" if EXPERT
8f9ca475 875 ---help---
7ae9392c
TP
876 Enabled scanning of DMI to identify machine quirks. Say Y
877 here unless you have verified that your setup is not
878 affected by entries in the DMI blacklist. Required by PNP
879 BIOS code.
880
506f1d07 881config GART_IOMMU
38901f1c 882 bool "Old AMD GART IOMMU support"
a4ce5a48 883 select IOMMU_HELPER
506f1d07 884 select SWIOTLB
23ac4ae8 885 depends on X86_64 && PCI && AMD_NB
8f9ca475 886 ---help---
ced3c42c
IM
887 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
888 GART based hardware IOMMUs.
889
890 The GART supports full DMA access for devices with 32-bit access
891 limitations, on systems with more than 3 GB. This is usually needed
892 for USB, sound, many IDE/SATA chipsets and some other devices.
893
894 Newer systems typically have a modern AMD IOMMU, supported via
895 the CONFIG_AMD_IOMMU=y config option.
896
897 In normal configurations this driver is only active when needed:
898 there's more than 3 GB of memory and the system contains a
899 32-bit limited device.
900
901 If unsure, say Y.
506f1d07
SR
902
903config CALGARY_IOMMU
904 bool "IBM Calgary IOMMU support"
a4ce5a48 905 select IOMMU_HELPER
506f1d07 906 select SWIOTLB
6ea30386 907 depends on X86_64 && PCI
8f9ca475 908 ---help---
506f1d07
SR
909 Support for hardware IOMMUs in IBM's xSeries x366 and x460
910 systems. Needed to run systems with more than 3GB of memory
911 properly with 32-bit PCI devices that do not support DAC
912 (Double Address Cycle). Calgary also supports bus level
913 isolation, where all DMAs pass through the IOMMU. This
914 prevents them from going anywhere except their intended
915 destination. This catches hard-to-find kernel bugs and
916 mis-behaving drivers and devices that do not use the DMA-API
917 properly to set up their DMA buffers. The IOMMU can be
918 turned off at boot time with the iommu=off parameter.
919 Normally the kernel will make the right choice by itself.
920 If unsure, say Y.
921
922config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
923 def_bool y
924 prompt "Should Calgary be enabled by default?"
506f1d07 925 depends on CALGARY_IOMMU
8f9ca475 926 ---help---
506f1d07
SR
927 Should Calgary be enabled by default? if you choose 'y', Calgary
928 will be used (if it exists). If you choose 'n', Calgary will not be
929 used even if it exists. If you choose 'n' and would like to use
930 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
931 If unsure, say Y.
506f1d07 932
1184dc2f 933config MAXSMP
ddb0c5a6 934 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 935 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 936 select CPUMASK_OFFSTACK
8f9ca475 937 ---help---
ddb0c5a6 938 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 939 If unsure, say N.
506f1d07 940
aec6487e
IM
941#
942# The maximum number of CPUs supported:
943#
944# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
945# and which can be configured interactively in the
946# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
947#
948# The ranges are different on 32-bit and 64-bit kernels, depending on
949# hardware capabilities and scalability features of the kernel.
950#
951# ( If MAXSMP is enabled we just use the highest possible value and disable
952# interactive configuration. )
953#
954
955config NR_CPUS_RANGE_BEGIN
a0d0bb4d 956 int
aec6487e
IM
957 default NR_CPUS_RANGE_END if MAXSMP
958 default 1 if !SMP
959 default 2
a0d0bb4d 960
aec6487e 961config NR_CPUS_RANGE_END
a0d0bb4d 962 int
aec6487e
IM
963 depends on X86_32
964 default 64 if SMP && X86_BIGSMP
965 default 8 if SMP && !X86_BIGSMP
966 default 1 if !SMP
a0d0bb4d 967
aec6487e 968config NR_CPUS_RANGE_END
a0d0bb4d 969 int
aec6487e
IM
970 depends on X86_64
971 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
972 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
973 default 1 if !SMP
a0d0bb4d 974
aec6487e 975config NR_CPUS_DEFAULT
a0d0bb4d
RD
976 int
977 depends on X86_32
aec6487e
IM
978 default 32 if X86_BIGSMP
979 default 8 if SMP
980 default 1 if !SMP
a0d0bb4d 981
aec6487e 982config NR_CPUS_DEFAULT
a0d0bb4d
RD
983 int
984 depends on X86_64
aec6487e
IM
985 default 8192 if MAXSMP
986 default 64 if SMP
987 default 1 if !SMP
a0d0bb4d 988
506f1d07 989config NR_CPUS
36f5101a 990 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
991 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
992 default NR_CPUS_DEFAULT
8f9ca475 993 ---help---
506f1d07 994 This allows you to specify the maximum number of CPUs which this
bb61ccc7 995 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 996 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
997 minimum value which makes sense is 2.
998
aec6487e
IM
999 This is purely to save memory: each supported CPU adds about 8KB
1000 to the kernel image.
506f1d07
SR
1001
1002config SCHED_SMT
1003 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 1004 depends on SMP
8f9ca475 1005 ---help---
506f1d07
SR
1006 SMT scheduler support improves the CPU scheduler's decision making
1007 when dealing with Intel Pentium 4 chips with HyperThreading at a
1008 cost of slightly increased overhead in some places. If unsure say
1009 N here.
1010
1011config SCHED_MC
3c2362e6
HH
1012 def_bool y
1013 prompt "Multi-core scheduler support"
c8e56d20 1014 depends on SMP
8f9ca475 1015 ---help---
506f1d07
SR
1016 Multi-core scheduler support improves the CPU scheduler's decision
1017 making when dealing with multi-core CPU chips at a cost of slightly
1018 increased overhead in some places. If unsure say N here.
1019
de966cf4
TC
1020config SCHED_MC_PRIO
1021 bool "CPU core priorities scheduler support"
0a21fc12
IM
1022 depends on SCHED_MC && CPU_SUP_INTEL
1023 select X86_INTEL_PSTATE
1024 select CPU_FREQ
de966cf4 1025 default y
5e76b2ab 1026 ---help---
0a21fc12
IM
1027 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1028 core ordering determined at manufacturing time, which allows
1029 certain cores to reach higher turbo frequencies (when running
1030 single threaded workloads) than others.
de966cf4 1031
0a21fc12
IM
1032 Enabling this kernel feature teaches the scheduler about
1033 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1034 scheduler's CPU selection logic accordingly, so that higher
1035 overall system performance can be achieved.
de966cf4 1036
0a21fc12 1037 This feature will have no effect on CPUs without this feature.
de966cf4 1038
0a21fc12 1039 If unsure say Y here.
5e76b2ab 1040
30b8b006
TG
1041config UP_LATE_INIT
1042 def_bool y
ba360f88 1043 depends on !SMP && X86_LOCAL_APIC
30b8b006 1044
506f1d07 1045config X86_UP_APIC
50849eef
JB
1046 bool "Local APIC support on uniprocessors" if !PCI_MSI
1047 default PCI_MSI
38a1dfda 1048 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1049 ---help---
506f1d07
SR
1050 A local APIC (Advanced Programmable Interrupt Controller) is an
1051 integrated interrupt controller in the CPU. If you have a single-CPU
1052 system which has a processor with a local APIC, you can say Y here to
1053 enable and use it. If you say Y here even though your machine doesn't
1054 have a local APIC, then the kernel will still run with no slowdown at
1055 all. The local APIC supports CPU-generated self-interrupts (timer,
1056 performance counters), and the NMI watchdog which detects hard
1057 lockups.
1058
1059config X86_UP_IOAPIC
1060 bool "IO-APIC support on uniprocessors"
1061 depends on X86_UP_APIC
8f9ca475 1062 ---help---
506f1d07
SR
1063 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1064 SMP-capable replacement for PC-style interrupt controllers. Most
1065 SMP systems and many recent uniprocessor systems have one.
1066
1067 If you have a single-CPU system with an IO-APIC, you can say Y here
1068 to use it. If you say Y here even though your machine doesn't have
1069 an IO-APIC, then the kernel will still run with no slowdown at all.
1070
1071config X86_LOCAL_APIC
3c2362e6 1072 def_bool y
0dbc6078 1073 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1074 select IRQ_DOMAIN_HIERARCHY
52f518a3 1075 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1076
1077config X86_IO_APIC
b1da1e71
JB
1078 def_bool y
1079 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1080
41b9eb26
SA
1081config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1082 bool "Reroute for broken boot IRQs"
41b9eb26 1083 depends on X86_IO_APIC
8f9ca475 1084 ---help---
41b9eb26
SA
1085 This option enables a workaround that fixes a source of
1086 spurious interrupts. This is recommended when threaded
1087 interrupt handling is used on systems where the generation of
1088 superfluous "boot interrupts" cannot be disabled.
1089
1090 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1091 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1092 kernel does during interrupt handling). On chipsets where this
1093 boot IRQ generation cannot be disabled, this workaround keeps
1094 the original IRQ line masked so that only the equivalent "boot
1095 IRQ" is delivered to the CPUs. The workaround also tells the
1096 kernel to set up the IRQ handler on the boot IRQ line. In this
1097 way only one interrupt is delivered to the kernel. Otherwise
1098 the spurious second interrupt may cause the kernel to bring
1099 down (vital) interrupt lines.
1100
1101 Only affects "broken" chipsets. Interrupt sharing may be
1102 increased on these systems.
1103
506f1d07 1104config X86_MCE
bab9bc65 1105 bool "Machine Check / overheating reporting"
648ed940 1106 select GENERIC_ALLOCATOR
e57dbaf7 1107 default y
506f1d07 1108 ---help---
bab9bc65
AK
1109 Machine Check support allows the processor to notify the
1110 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1111 The action the kernel takes depends on the severity of the problem,
bab9bc65 1112 ranging from warning messages to halting the machine.
4efc0670 1113
5de97c9f
TL
1114config X86_MCELOG_LEGACY
1115 bool "Support for deprecated /dev/mcelog character device"
1116 depends on X86_MCE
1117 ---help---
1118 Enable support for /dev/mcelog which is needed by the old mcelog
1119 userspace logging daemon. Consider switching to the new generation
1120 rasdaemon solution.
1121
506f1d07 1122config X86_MCE_INTEL
3c2362e6
HH
1123 def_bool y
1124 prompt "Intel MCE features"
c1ebf835 1125 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1126 ---help---
506f1d07
SR
1127 Additional support for intel specific MCE features such as
1128 the thermal monitor.
1129
1130config X86_MCE_AMD
3c2362e6
HH
1131 def_bool y
1132 prompt "AMD MCE features"
f5382de9 1133 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1134 ---help---
506f1d07
SR
1135 Additional support for AMD specific MCE features such as
1136 the DRAM Error Threshold.
1137
4efc0670 1138config X86_ANCIENT_MCE
6fc108a0 1139 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1140 depends on X86_32 && X86_MCE
cd13adcc
HS
1141 ---help---
1142 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1143 systems. These typically need to be enabled explicitly on the command
cd13adcc 1144 line.
4efc0670 1145
b2762686
AK
1146config X86_MCE_THRESHOLD
1147 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1148 def_bool y
b2762686 1149
ea149b36 1150config X86_MCE_INJECT
bc8e80d5 1151 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1152 tristate "Machine check injector support"
1153 ---help---
1154 Provide support for injecting machine checks for testing purposes.
1155 If you don't know what a machine check is and you don't do kernel
1156 QA it is safe to say n.
1157
4efc0670
AK
1158config X86_THERMAL_VECTOR
1159 def_bool y
5bb38adc 1160 depends on X86_MCE_INTEL
4efc0670 1161
07dc900e 1162source "arch/x86/events/Kconfig"
e633c65a 1163
5aef51c3 1164config X86_LEGACY_VM86
1e642812 1165 bool "Legacy VM86 support"
506f1d07 1166 depends on X86_32
8f9ca475 1167 ---help---
5aef51c3
AL
1168 This option allows user programs to put the CPU into V8086
1169 mode, which is an 80286-era approximation of 16-bit real mode.
1170
1171 Some very old versions of X and/or vbetool require this option
1172 for user mode setting. Similarly, DOSEMU will use it if
1173 available to accelerate real mode DOS programs. However, any
1174 recent version of DOSEMU, X, or vbetool should be fully
1175 functional even without kernel VM86 support, as they will all
1e642812
IM
1176 fall back to software emulation. Nevertheless, if you are using
1177 a 16-bit DOS program where 16-bit performance matters, vm86
1178 mode might be faster than emulation and you might want to
1179 enable this option.
5aef51c3 1180
1e642812
IM
1181 Note that any app that works on a 64-bit kernel is unlikely to
1182 need this option, as 64-bit kernels don't, and can't, support
1183 V8086 mode. This option is also unrelated to 16-bit protected
1184 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1185
1e642812
IM
1186 Enabling this option increases the complexity of the kernel
1187 and slows down exception handling a tiny bit.
5aef51c3 1188
1e642812 1189 If unsure, say N here.
5aef51c3
AL
1190
1191config VM86
1192 bool
1193 default X86_LEGACY_VM86
34273f41
PA
1194
1195config X86_16BIT
1196 bool "Enable support for 16-bit segments" if EXPERT
1197 default y
a5b9e5a2 1198 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1199 ---help---
1200 This option is required by programs like Wine to run 16-bit
1201 protected mode legacy code on x86 processors. Disabling
1202 this option saves about 300 bytes on i386, or around 6K text
1203 plus 16K runtime memory on x86-64,
1204
1205config X86_ESPFIX32
1206 def_bool y
1207 depends on X86_16BIT && X86_32
506f1d07 1208
197725de
PA
1209config X86_ESPFIX64
1210 def_bool y
34273f41 1211 depends on X86_16BIT && X86_64
506f1d07 1212
1ad83c85
AL
1213config X86_VSYSCALL_EMULATION
1214 bool "Enable vsyscall emulation" if EXPERT
1215 default y
1216 depends on X86_64
1217 ---help---
1218 This enables emulation of the legacy vsyscall page. Disabling
1219 it is roughly equivalent to booting with vsyscall=none, except
1220 that it will also disable the helpful warning if a program
1221 tries to use a vsyscall. With this option set to N, offending
1222 programs will just segfault, citing addresses of the form
1223 0xffffffffff600?00.
1224
1225 This option is required by many programs built before 2013, and
1226 care should be used even with newer programs if set to N.
1227
1228 Disabling this option saves about 7K of kernel size and
1229 possibly 4K of additional runtime pagetable memory.
1230
506f1d07
SR
1231config TOSHIBA
1232 tristate "Toshiba Laptop support"
1233 depends on X86_32
1234 ---help---
1235 This adds a driver to safely access the System Management Mode of
1236 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1237 not work on models with a Phoenix BIOS. The System Management Mode
1238 is used to set the BIOS and power saving options on Toshiba portables.
1239
1240 For information on utilities to make use of this driver see the
1241 Toshiba Linux utilities web site at:
1242 <http://www.buzzard.org.uk/toshiba/>.
1243
1244 Say Y if you intend to run this kernel on a Toshiba portable.
1245 Say N otherwise.
1246
1247config I8K
039ae585 1248 tristate "Dell i8k legacy laptop support"
949a9d70 1249 select HWMON
039ae585 1250 select SENSORS_DELL_SMM
506f1d07 1251 ---help---
039ae585
PR
1252 This option enables legacy /proc/i8k userspace interface in hwmon
1253 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1254 temperature and allows controlling fan speeds of Dell laptops via
1255 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1256 it reports also power and hotkey status. For fan speed control is
1257 needed userspace package i8kutils.
1258
1259 Say Y if you intend to run this kernel on old Dell laptops or want to
1260 use userspace package i8kutils.
506f1d07
SR
1261 Say N otherwise.
1262
1263config X86_REBOOTFIXUPS
9ba16087
JB
1264 bool "Enable X86 board specific fixups for reboot"
1265 depends on X86_32
506f1d07
SR
1266 ---help---
1267 This enables chipset and/or board specific fixups to be done
1268 in order to get reboot to work correctly. This is only needed on
1269 some combinations of hardware and BIOS. The symptom, for which
1270 this config is intended, is when reboot ends with a stalled/hung
1271 system.
1272
1273 Currently, the only fixup is for the Geode machines using
5e3a77e9 1274 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1275
1276 Say Y if you want to enable the fixup. Currently, it's safe to
1277 enable this option even if you don't need it.
1278 Say N otherwise.
1279
1280config MICROCODE
9a2bc335
BP
1281 bool "CPU microcode loading support"
1282 default y
80030e3d 1283 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1284 select FW_LOADER
1285 ---help---
1286 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1287 Intel and AMD processors. The Intel support is for the IA32 family,
1288 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1289 AMD support is for families 0x10 and later. You will obviously need
1290 the actual microcode binary data itself which is not shipped with
1291 the Linux kernel.
1292
1293 The preferred method to load microcode from a detached initrd is described
1897a969 1294 in Documentation/x86/microcode.txt. For that you need to enable
5f9c01aa
BP
1295 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1296 initrd for microcode blobs.
1297
c508c46e
BG
1298 In addition, you can build the microcode into the kernel. For that you
1299 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1300 config option.
506f1d07 1301
8d86f390 1302config MICROCODE_INTEL
e43f6e67 1303 bool "Intel microcode loading support"
8f9ca475
IM
1304 depends on MICROCODE
1305 default MICROCODE
1306 select FW_LOADER
1307 ---help---
1308 This options enables microcode patch loading support for Intel
1309 processors.
1310
b8989db9
A
1311 For the current Intel microcode data package go to
1312 <https://downloadcenter.intel.com> and search for
1313 'Linux Processor Microcode Data File'.
8d86f390 1314
80cc9f10 1315config MICROCODE_AMD
e43f6e67 1316 bool "AMD microcode loading support"
8f9ca475
IM
1317 depends on MICROCODE
1318 select FW_LOADER
1319 ---help---
1320 If you select this option, microcode patch loading support for AMD
1321 processors will be enabled.
80cc9f10 1322
8f9ca475 1323config MICROCODE_OLD_INTERFACE
3c2362e6 1324 def_bool y
506f1d07 1325 depends on MICROCODE
506f1d07
SR
1326
1327config X86_MSR
1328 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1329 ---help---
506f1d07
SR
1330 This device gives privileged processes access to the x86
1331 Model-Specific Registers (MSRs). It is a character device with
1332 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1333 MSR accesses are directed to a specific CPU on multi-processor
1334 systems.
1335
1336config X86_CPUID
1337 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1338 ---help---
506f1d07
SR
1339 This device gives processes access to the x86 CPUID instruction to
1340 be executed on a specific processor. It is a character device
1341 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1342 /dev/cpu/31/cpuid.
1343
1344choice
1345 prompt "High Memory Support"
6fc108a0 1346 default HIGHMEM4G
506f1d07
SR
1347 depends on X86_32
1348
1349config NOHIGHMEM
1350 bool "off"
506f1d07
SR
1351 ---help---
1352 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1353 However, the address space of 32-bit x86 processors is only 4
1354 Gigabytes large. That means that, if you have a large amount of
1355 physical memory, not all of it can be "permanently mapped" by the
1356 kernel. The physical memory that's not permanently mapped is called
1357 "high memory".
1358
1359 If you are compiling a kernel which will never run on a machine with
1360 more than 1 Gigabyte total physical RAM, answer "off" here (default
1361 choice and suitable for most users). This will result in a "3GB/1GB"
1362 split: 3GB are mapped so that each process sees a 3GB virtual memory
1363 space and the remaining part of the 4GB virtual memory space is used
1364 by the kernel to permanently map as much physical memory as
1365 possible.
1366
1367 If the machine has between 1 and 4 Gigabytes physical RAM, then
1368 answer "4GB" here.
1369
1370 If more than 4 Gigabytes is used then answer "64GB" here. This
1371 selection turns Intel PAE (Physical Address Extension) mode on.
1372 PAE implements 3-level paging on IA32 processors. PAE is fully
1373 supported by Linux, PAE mode is implemented on all recent Intel
1374 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1375 then the kernel will not boot on CPUs that don't support PAE!
1376
1377 The actual amount of total physical memory will either be
1378 auto detected or can be forced by using a kernel command line option
1379 such as "mem=256M". (Try "man bootparam" or see the documentation of
1380 your boot loader (lilo or loadlin) about how to pass options to the
1381 kernel at boot time.)
1382
1383 If unsure, say "off".
1384
1385config HIGHMEM4G
1386 bool "4GB"
8f9ca475 1387 ---help---
506f1d07
SR
1388 Select this if you have a 32-bit processor and between 1 and 4
1389 gigabytes of physical RAM.
1390
1391config HIGHMEM64G
1392 bool "64GB"
69b8d3fc 1393 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1394 select X86_PAE
8f9ca475 1395 ---help---
506f1d07
SR
1396 Select this if you have a 32-bit processor and more than 4
1397 gigabytes of physical RAM.
1398
1399endchoice
1400
1401choice
6a108a14 1402 prompt "Memory split" if EXPERT
506f1d07
SR
1403 default VMSPLIT_3G
1404 depends on X86_32
8f9ca475 1405 ---help---
506f1d07
SR
1406 Select the desired split between kernel and user memory.
1407
1408 If the address range available to the kernel is less than the
1409 physical memory installed, the remaining memory will be available
1410 as "high memory". Accessing high memory is a little more costly
1411 than low memory, as it needs to be mapped into the kernel first.
1412 Note that increasing the kernel address space limits the range
1413 available to user programs, making the address space there
1414 tighter. Selecting anything other than the default 3G/1G split
1415 will also likely make your kernel incompatible with binary-only
1416 kernel modules.
1417
1418 If you are not absolutely sure what you are doing, leave this
1419 option alone!
1420
1421 config VMSPLIT_3G
1422 bool "3G/1G user/kernel split"
1423 config VMSPLIT_3G_OPT
1424 depends on !X86_PAE
1425 bool "3G/1G user/kernel split (for full 1G low memory)"
1426 config VMSPLIT_2G
1427 bool "2G/2G user/kernel split"
1428 config VMSPLIT_2G_OPT
1429 depends on !X86_PAE
1430 bool "2G/2G user/kernel split (for full 2G low memory)"
1431 config VMSPLIT_1G
1432 bool "1G/3G user/kernel split"
1433endchoice
1434
1435config PAGE_OFFSET
1436 hex
1437 default 0xB0000000 if VMSPLIT_3G_OPT
1438 default 0x80000000 if VMSPLIT_2G
1439 default 0x78000000 if VMSPLIT_2G_OPT
1440 default 0x40000000 if VMSPLIT_1G
1441 default 0xC0000000
1442 depends on X86_32
1443
1444config HIGHMEM
3c2362e6 1445 def_bool y
506f1d07 1446 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1447
1448config X86_PAE
9ba16087 1449 bool "PAE (Physical Address Extension) Support"
506f1d07 1450 depends on X86_32 && !HIGHMEM4G
d4a451d5 1451 select PHYS_ADDR_T_64BIT
9d99c712 1452 select SWIOTLB
8f9ca475 1453 ---help---
506f1d07
SR
1454 PAE is required for NX support, and furthermore enables
1455 larger swapspace support for non-overcommit purposes. It
1456 has the cost of more pagetable lookup overhead, and also
1457 consumes more pagetable space per process.
1458
77ef56e4
KS
1459config X86_5LEVEL
1460 bool "Enable 5-level page tables support"
eedb92ab 1461 select DYNAMIC_MEMORY_LAYOUT
162434e7 1462 select SPARSEMEM_VMEMMAP
77ef56e4
KS
1463 depends on X86_64
1464 ---help---
1465 5-level paging enables access to larger address space:
1466 upto 128 PiB of virtual address space and 4 PiB of
1467 physical address space.
1468
1469 It will be supported by future Intel CPUs.
1470
6657fca0
KS
1471 A kernel with the option enabled can be booted on machines that
1472 support 4- or 5-level paging.
77ef56e4
KS
1473
1474 See Documentation/x86/x86_64/5level-paging.txt for more
1475 information.
1476
1477 Say N if unsure.
1478
10971ab2 1479config X86_DIRECT_GBPAGES
e5008abe 1480 def_bool y
4675ff05 1481 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1482 ---help---
10971ab2
IM
1483 Certain kernel features effectively disable kernel
1484 linear 1 GB mappings (even if the CPU otherwise
1485 supports them), so don't confuse the user by printing
1486 that we have them enabled.
9e899816 1487
5c280cf6
TG
1488config X86_CPA_STATISTICS
1489 bool "Enable statistic for Change Page Attribute"
1490 depends on DEBUG_FS
1491 ---help---
1492 Expose statistics about the Change Page Attribute mechanims, which
1493 helps to determine the effectivness of preserving large and huge
1494 page mappings when mapping protections are changed.
1495
7744ccdb
TL
1496config ARCH_HAS_MEM_ENCRYPT
1497 def_bool y
1498
1499config AMD_MEM_ENCRYPT
1500 bool "AMD Secure Memory Encryption (SME) support"
1501 depends on X86_64 && CPU_SUP_AMD
94d49eb3 1502 select DYNAMIC_PHYSICAL_MASK
7744ccdb
TL
1503 ---help---
1504 Say yes to enable support for the encryption of system memory.
1505 This requires an AMD processor that supports Secure Memory
1506 Encryption (SME).
1507
1508config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1509 bool "Activate AMD Secure Memory Encryption (SME) by default"
1510 default y
1511 depends on AMD_MEM_ENCRYPT
1512 ---help---
1513 Say yes to have system memory encrypted by default if running on
1514 an AMD processor that supports Secure Memory Encryption (SME).
1515
1516 If set to Y, then the encryption of system memory can be
1517 deactivated with the mem_encrypt=off command line option.
1518
1519 If set to N, then the encryption of system memory can be
1520 activated with the mem_encrypt=on command line option.
1521
f88a68fa
TL
1522config ARCH_USE_MEMREMAP_PROT
1523 def_bool y
1524 depends on AMD_MEM_ENCRYPT
1525
506f1d07
SR
1526# Common NUMA Features
1527config NUMA
fd51b2d7 1528 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1529 depends on SMP
b5660ba7
PA
1530 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1531 default y if X86_BIGSMP
8f9ca475 1532 ---help---
506f1d07 1533 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1534
506f1d07
SR
1535 The kernel will try to allocate memory used by a CPU on the
1536 local memory controller of the CPU and add some more
1537 NUMA awareness to the kernel.
1538
c280ea5e 1539 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1540 (or later), AMD Opteron, or EM64T NUMA.
1541
b5660ba7 1542 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1543 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1544
1545 Otherwise, you should say N.
506f1d07 1546
eec1d4fa 1547config AMD_NUMA
3c2362e6
HH
1548 def_bool y
1549 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1550 depends on X86_64 && NUMA && PCI
8f9ca475 1551 ---help---
eec1d4fa
HR
1552 Enable AMD NUMA node topology detection. You should say Y here if
1553 you have a multi processor AMD system. This uses an old method to
1554 read the NUMA configuration directly from the builtin Northbridge
1555 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1556 which also takes priority if both are compiled in.
506f1d07
SR
1557
1558config X86_64_ACPI_NUMA
3c2362e6
HH
1559 def_bool y
1560 prompt "ACPI NUMA detection"
506f1d07
SR
1561 depends on X86_64 && NUMA && ACPI && PCI
1562 select ACPI_NUMA
8f9ca475 1563 ---help---
506f1d07
SR
1564 Enable ACPI SRAT based node topology detection.
1565
6ec6e0d9
SS
1566# Some NUMA nodes have memory ranges that span
1567# other nodes. Even though a pfn is valid and
1568# between a node's start and end pfns, it may not
1569# reside on that node. See memmap_init_zone()
1570# for details.
1571config NODES_SPAN_OTHER_NODES
1572 def_bool y
1573 depends on X86_64_ACPI_NUMA
1574
506f1d07
SR
1575config NUMA_EMU
1576 bool "NUMA emulation"
1b7e03ef 1577 depends on NUMA
8f9ca475 1578 ---help---
506f1d07
SR
1579 Enable NUMA emulation. A flat machine will be split
1580 into virtual nodes when booted with "numa=fake=N", where N is the
1581 number of nodes. This is only useful for debugging.
1582
1583config NODES_SHIFT
d25e26b6 1584 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1585 range 1 10
1586 default "10" if MAXSMP
506f1d07 1587 default "6" if X86_64
506f1d07
SR
1588 default "3"
1589 depends on NEED_MULTIPLE_NODES
8f9ca475 1590 ---help---
1184dc2f 1591 Specify the maximum number of NUMA Nodes available on the target
692105b8 1592 system. Increases memory reserved to accommodate various tables.
506f1d07 1593
506f1d07 1594config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1595 def_bool y
506f1d07 1596 depends on X86_32 && DISCONTIGMEM
506f1d07 1597
506f1d07
SR
1598config ARCH_FLATMEM_ENABLE
1599 def_bool y
3b16651f 1600 depends on X86_32 && !NUMA
506f1d07
SR
1601
1602config ARCH_DISCONTIGMEM_ENABLE
1603 def_bool y
b263295d 1604 depends on NUMA && X86_32
506f1d07
SR
1605
1606config ARCH_DISCONTIGMEM_DEFAULT
1607 def_bool y
b263295d
CL
1608 depends on NUMA && X86_32
1609
506f1d07
SR
1610config ARCH_SPARSEMEM_ENABLE
1611 def_bool y
6ea30386 1612 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1613 select SPARSEMEM_STATIC if X86_32
1614 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1615
3b16651f
TH
1616config ARCH_SPARSEMEM_DEFAULT
1617 def_bool y
1618 depends on X86_64
1619
506f1d07
SR
1620config ARCH_SELECT_MEMORY_MODEL
1621 def_bool y
b263295d 1622 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1623
1624config ARCH_MEMORY_PROBE
a0842b70 1625 bool "Enable sysfs memory/probe interface"
3120e25e 1626 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1627 help
1628 This option enables a sysfs memory/probe interface for testing.
1629 See Documentation/memory-hotplug.txt for more information.
1630 If you are unsure how to answer this question, answer N.
506f1d07 1631
3b16651f
TH
1632config ARCH_PROC_KCORE_TEXT
1633 def_bool y
1634 depends on X86_64 && PROC_KCORE
1635
a29815a3
AK
1636config ILLEGAL_POINTER_VALUE
1637 hex
1638 default 0 if X86_32
1639 default 0xdead000000000000 if X86_64
1640
7a67832c
DW
1641config X86_PMEM_LEGACY_DEVICE
1642 bool
1643
ec776ef6 1644config X86_PMEM_LEGACY
7a67832c 1645 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1646 depends on PHYS_ADDR_T_64BIT
1647 depends on BLK_DEV
7a67832c 1648 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1649 select LIBNVDIMM
ec776ef6
CH
1650 help
1651 Treat memory marked using the non-standard e820 type of 12 as used
1652 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1653 The kernel will offer these regions to the 'pmem' driver so
1654 they can be used for persistent storage.
1655
1656 Say Y if unsure.
1657
506f1d07
SR
1658config HIGHPTE
1659 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1660 depends on HIGHMEM
8f9ca475 1661 ---help---
506f1d07
SR
1662 The VM uses one page table entry for each page of physical memory.
1663 For systems with a lot of RAM, this can be wasteful of precious
1664 low memory. Setting this option will put user-space page table
1665 entries in high memory.
1666
9f077871 1667config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1668 bool "Check for low memory corruption"
1669 ---help---
1670 Periodically check for memory corruption in low memory, which
1671 is suspected to be caused by BIOS. Even when enabled in the
1672 configuration, it is disabled at runtime. Enable it by
1673 setting "memory_corruption_check=1" on the kernel command
1674 line. By default it scans the low 64k of memory every 60
1675 seconds; see the memory_corruption_check_size and
1676 memory_corruption_check_period parameters in
8c27ceff 1677 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1678
1679 When enabled with the default parameters, this option has
1680 almost no overhead, as it reserves a relatively small amount
1681 of memory and scans it infrequently. It both detects corruption
1682 and prevents it from affecting the running system.
1683
1684 It is, however, intended as a diagnostic tool; if repeatable
1685 BIOS-originated corruption always affects the same memory,
1686 you can use memmap= to prevent the kernel from using that
1687 memory.
9f077871 1688
c885df50 1689config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1690 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1691 depends on X86_CHECK_BIOS_CORRUPTION
1692 default y
8f9ca475
IM
1693 ---help---
1694 Set whether the default state of memory_corruption_check is
1695 on or off.
c885df50 1696
9ea77bdb 1697config X86_RESERVE_LOW
d0cd7425
PA
1698 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1699 default 64
1700 range 4 640
8f9ca475 1701 ---help---
d0cd7425
PA
1702 Specify the amount of low memory to reserve for the BIOS.
1703
1704 The first page contains BIOS data structures that the kernel
1705 must not use, so that page must always be reserved.
1706
1707 By default we reserve the first 64K of physical RAM, as a
1708 number of BIOSes are known to corrupt that memory range
1709 during events such as suspend/resume or monitor cable
1710 insertion, so it must not be used by the kernel.
fc381519 1711
d0cd7425
PA
1712 You can set this to 4 if you are absolutely sure that you
1713 trust the BIOS to get all its memory reservations and usages
1714 right. If you know your BIOS have problems beyond the
1715 default 64K area, you can set this to 640 to avoid using the
1716 entire low memory range.
fc381519 1717
d0cd7425
PA
1718 If you have doubts about the BIOS (e.g. suspend/resume does
1719 not work or there's kernel crashes after certain hardware
1720 hotplug events) then you might want to enable
1721 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1722 typical corruption patterns.
fc381519 1723
d0cd7425 1724 Leave this to the default value of 64 if you are unsure.
fc381519 1725
506f1d07
SR
1726config MATH_EMULATION
1727 bool
a5b9e5a2 1728 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1729 prompt "Math emulation" if X86_32
1730 ---help---
1731 Linux can emulate a math coprocessor (used for floating point
1732 operations) if you don't have one. 486DX and Pentium processors have
1733 a math coprocessor built in, 486SX and 386 do not, unless you added
1734 a 487DX or 387, respectively. (The messages during boot time can
1735 give you some hints here ["man dmesg"].) Everyone needs either a
1736 coprocessor or this emulation.
1737
1738 If you don't have a math coprocessor, you need to say Y here; if you
1739 say Y here even though you have a coprocessor, the coprocessor will
1740 be used nevertheless. (This behavior can be changed with the kernel
1741 command line option "no387", which comes handy if your coprocessor
1742 is broken. Try "man bootparam" or see the documentation of your boot
1743 loader (lilo or loadlin) about how to pass options to the kernel at
1744 boot time.) This means that it is a good idea to say Y here if you
1745 intend to use this kernel on different machines.
1746
1747 More information about the internals of the Linux math coprocessor
1748 emulation can be found in <file:arch/x86/math-emu/README>.
1749
1750 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1751 kernel, it won't hurt.
1752
1753config MTRR
6fc108a0 1754 def_bool y
6a108a14 1755 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1756 ---help---
1757 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1758 the Memory Type Range Registers (MTRRs) may be used to control
1759 processor access to memory ranges. This is most useful if you have
1760 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1761 allows bus write transfers to be combined into a larger transfer
1762 before bursting over the PCI/AGP bus. This can increase performance
1763 of image write operations 2.5 times or more. Saying Y here creates a
1764 /proc/mtrr file which may be used to manipulate your processor's
1765 MTRRs. Typically the X server should use this.
1766
1767 This code has a reasonably generic interface so that similar
1768 control registers on other processors can be easily supported
1769 as well:
1770
1771 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1772 Registers (ARRs) which provide a similar functionality to MTRRs. For
1773 these, the ARRs are used to emulate the MTRRs.
1774 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1775 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1776 write-combining. All of these processors are supported by this code
1777 and it makes sense to say Y here if you have one of them.
1778
1779 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1780 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1781 can lead to all sorts of problems, so it's good to say Y here.
1782
1783 You can safely say Y even if your machine doesn't have MTRRs, you'll
1784 just add about 9 KB to your kernel.
1785
7225e751 1786 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1787
95ffa243 1788config MTRR_SANITIZER
2ffb3501 1789 def_bool y
95ffa243
YL
1790 prompt "MTRR cleanup support"
1791 depends on MTRR
8f9ca475 1792 ---help---
aba3728c
TG
1793 Convert MTRR layout from continuous to discrete, so X drivers can
1794 add writeback entries.
95ffa243 1795
aba3728c 1796 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1797 The largest mtrr entry size for a continuous block can be set with
aba3728c 1798 mtrr_chunk_size.
95ffa243 1799
2ffb3501 1800 If unsure, say Y.
95ffa243
YL
1801
1802config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1803 int "MTRR cleanup enable value (0-1)"
1804 range 0 1
1805 default "0"
95ffa243 1806 depends on MTRR_SANITIZER
8f9ca475 1807 ---help---
f5098d62 1808 Enable mtrr cleanup default value
95ffa243 1809
12031a62
YL
1810config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1811 int "MTRR cleanup spare reg num (0-7)"
1812 range 0 7
1813 default "1"
1814 depends on MTRR_SANITIZER
8f9ca475 1815 ---help---
12031a62 1816 mtrr cleanup spare entries default, it can be changed via
aba3728c 1817 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1818
2e5d9c85 1819config X86_PAT
6fc108a0 1820 def_bool y
6a108a14 1821 prompt "x86 PAT support" if EXPERT
2a8a2719 1822 depends on MTRR
8f9ca475 1823 ---help---
2e5d9c85 1824 Use PAT attributes to setup page level cache control.
042b78e4 1825
2e5d9c85 1826 PATs are the modern equivalents of MTRRs and are much more
1827 flexible than MTRRs.
1828
1829 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1830 spontaneous reboots) or a non-working video driver.
2e5d9c85 1831
1832 If unsure, say Y.
1833
46cf98cd
VP
1834config ARCH_USES_PG_UNCACHED
1835 def_bool y
1836 depends on X86_PAT
1837
628c6246
PA
1838config ARCH_RANDOM
1839 def_bool y
1840 prompt "x86 architectural random number generator" if EXPERT
1841 ---help---
1842 Enable the x86 architectural RDRAND instruction
1843 (Intel Bull Mountain technology) to generate random numbers.
1844 If supported, this is a high bandwidth, cryptographically
1845 secure hardware random number generator.
1846
51ae4a2d
PA
1847config X86_SMAP
1848 def_bool y
1849 prompt "Supervisor Mode Access Prevention" if EXPERT
1850 ---help---
1851 Supervisor Mode Access Prevention (SMAP) is a security
1852 feature in newer Intel processors. There is a small
1853 performance cost if this enabled and turned on; there is
1854 also a small increase in the kernel size if this is enabled.
1855
1856 If unsure, say Y.
1857
aa35f896 1858config X86_INTEL_UMIP
796ebc81 1859 def_bool y
aa35f896
RN
1860 depends on CPU_SUP_INTEL
1861 prompt "Intel User Mode Instruction Prevention" if EXPERT
1862 ---help---
1863 The User Mode Instruction Prevention (UMIP) is a security
1864 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1865 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1866 or STR instructions are executed in user mode. These instructions
1867 unnecessarily expose information about the hardware state.
1868
1869 The vast majority of applications do not use these instructions.
1870 For the very few that do, software emulation is provided in
1871 specific cases in protected and virtual-8086 modes. Emulated
1872 results are dummy.
aa35f896 1873
72e9b5fe
DH
1874config X86_INTEL_MPX
1875 prompt "Intel MPX (Memory Protection Extensions)"
1876 def_bool n
df3735c5
RR
1877 # Note: only available in 64-bit mode due to VMA flags shortage
1878 depends on CPU_SUP_INTEL && X86_64
1879 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1880 ---help---
1881 MPX provides hardware features that can be used in
1882 conjunction with compiler-instrumented code to check
1883 memory references. It is designed to detect buffer
1884 overflow or underflow bugs.
1885
1886 This option enables running applications which are
1887 instrumented or otherwise use MPX. It does not use MPX
1888 itself inside the kernel or to protect the kernel
1889 against bad memory references.
1890
1891 Enabling this option will make the kernel larger:
1892 ~8k of kernel text and 36 bytes of data on a 64-bit
1893 defconfig. It adds a long to the 'mm_struct' which
1894 will increase the kernel memory overhead of each
1895 process and adds some branches to paths used during
1896 exec() and munmap().
1897
1898 For details, see Documentation/x86/intel_mpx.txt
1899
1900 If unsure, say N.
1901
35e97790 1902config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1903 prompt "Intel Memory Protection Keys"
35e97790 1904 def_bool y
284244a9 1905 # Note: only available in 64-bit mode
35e97790 1906 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1907 select ARCH_USES_HIGH_VMA_FLAGS
1908 select ARCH_HAS_PKEYS
284244a9
DH
1909 ---help---
1910 Memory Protection Keys provides a mechanism for enforcing
1911 page-based protections, but without requiring modification of the
1912 page tables when an application changes protection domains.
1913
1914 For details, see Documentation/x86/protection-keys.txt
1915
1916 If unsure, say y.
35e97790 1917
506f1d07 1918config EFI
9ba16087 1919 bool "EFI runtime service support"
5b83683f 1920 depends on ACPI
f6ce5002 1921 select UCS2_STRING
022ee6c5 1922 select EFI_RUNTIME_WRAPPERS
506f1d07 1923 ---help---
8f9ca475
IM
1924 This enables the kernel to use EFI runtime services that are
1925 available (such as the EFI variable services).
506f1d07 1926
8f9ca475
IM
1927 This option is only useful on systems that have EFI firmware.
1928 In addition, you should use the latest ELILO loader available
1929 at <http://elilo.sourceforge.net> in order to take advantage
1930 of EFI runtime services. However, even with this option, the
1931 resultant kernel should continue to boot on existing non-EFI
1932 platforms.
506f1d07 1933
291f3632
MF
1934config EFI_STUB
1935 bool "EFI stub support"
b16d8c23 1936 depends on EFI && !X86_USE_3DNOW
7b2a583a 1937 select RELOCATABLE
291f3632
MF
1938 ---help---
1939 This kernel feature allows a bzImage to be loaded directly
1940 by EFI firmware without the use of a bootloader.
1941
4172fe2f 1942 See Documentation/efi-stub.txt for more information.
0c759662 1943
7d453eee
MF
1944config EFI_MIXED
1945 bool "EFI mixed-mode support"
1946 depends on EFI_STUB && X86_64
1947 ---help---
1948 Enabling this feature allows a 64-bit kernel to be booted
1949 on a 32-bit firmware, provided that your CPU supports 64-bit
1950 mode.
1951
1952 Note that it is not possible to boot a mixed-mode enabled
1953 kernel via the EFI boot stub - a bootloader that supports
1954 the EFI handover protocol must be used.
1955
1956 If unsure, say N.
1957
506f1d07 1958config SECCOMP
3c2362e6
HH
1959 def_bool y
1960 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1961 ---help---
506f1d07
SR
1962 This kernel feature is useful for number crunching applications
1963 that may need to compute untrusted bytecode during their
1964 execution. By using pipes or other transports made available to
1965 the process as file descriptors supporting the read/write
1966 syscalls, it's possible to isolate those applications in
1967 their own address space using seccomp. Once seccomp is
9c0bbee8 1968 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1969 and the task is only allowed to execute a few safe syscalls
1970 defined by each seccomp mode.
1971
1972 If unsure, say Y. Only embedded should say N here.
1973
506f1d07
SR
1974source kernel/Kconfig.hz
1975
1976config KEXEC
1977 bool "kexec system call"
2965faa5 1978 select KEXEC_CORE
8f9ca475 1979 ---help---
506f1d07
SR
1980 kexec is a system call that implements the ability to shutdown your
1981 current kernel, and to start another kernel. It is like a reboot
1982 but it is independent of the system firmware. And like a reboot
1983 you can start any kernel with it, not just Linux.
1984
1985 The name comes from the similarity to the exec system call.
1986
1987 It is an ongoing process to be certain the hardware in a machine
1988 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1989 initially work for you. As of this writing the exact hardware
1990 interface is strongly in flux, so no good recommendation can be
1991 made.
506f1d07 1992
74ca317c
VG
1993config KEXEC_FILE
1994 bool "kexec file based system call"
2965faa5 1995 select KEXEC_CORE
74ca317c 1996 select BUILD_BIN2C
74ca317c
VG
1997 depends on X86_64
1998 depends on CRYPTO=y
1999 depends on CRYPTO_SHA256=y
2000 ---help---
2001 This is new version of kexec system call. This system call is
2002 file based and takes file descriptors as system call argument
2003 for kernel and initramfs as opposed to list of segments as
2004 accepted by previous system call.
2005
b799a09f
AT
2006config ARCH_HAS_KEXEC_PURGATORY
2007 def_bool KEXEC_FILE
2008
8e7d8381
VG
2009config KEXEC_VERIFY_SIG
2010 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2011 depends on KEXEC_FILE
8e7d8381
VG
2012 ---help---
2013 This option makes kernel signature verification mandatory for
d8eb8940
BP
2014 the kexec_file_load() syscall.
2015
2016 In addition to that option, you need to enable signature
2017 verification for the corresponding kernel image type being
2018 loaded in order for this to work.
8e7d8381
VG
2019
2020config KEXEC_BZIMAGE_VERIFY_SIG
2021 bool "Enable bzImage signature verification support"
2022 depends on KEXEC_VERIFY_SIG
2023 depends on SIGNED_PE_FILE_VERIFICATION
2024 select SYSTEM_TRUSTED_KEYRING
2025 ---help---
2026 Enable bzImage signature verification support.
2027
506f1d07 2028config CRASH_DUMP
04b69447 2029 bool "kernel crash dumps"
506f1d07 2030 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 2031 ---help---
506f1d07
SR
2032 Generate crash dump after being started by kexec.
2033 This should be normally only set in special crash dump kernels
2034 which are loaded in the main kernel with kexec-tools into
2035 a specially reserved region and then later executed after
2036 a crash by kdump/kexec. The crash dump kernel must be compiled
2037 to a memory address not used by the main kernel or BIOS using
2038 PHYSICAL_START, or it must be built as a relocatable image
2039 (CONFIG_RELOCATABLE=y).
2040 For more details see Documentation/kdump/kdump.txt
2041
3ab83521 2042config KEXEC_JUMP
6ea30386 2043 bool "kexec jump"
fee7b0d8 2044 depends on KEXEC && HIBERNATION
8f9ca475 2045 ---help---
89081d17
HY
2046 Jump between original kernel and kexeced kernel and invoke
2047 code in physical address mode via KEXEC
3ab83521 2048
506f1d07 2049config PHYSICAL_START
6a108a14 2050 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2051 default "0x1000000"
8f9ca475 2052 ---help---
506f1d07
SR
2053 This gives the physical address where the kernel is loaded.
2054
2055 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2056 bzImage will decompress itself to above physical address and
2057 run from there. Otherwise, bzImage will run from the address where
2058 it has been loaded by the boot loader and will ignore above physical
2059 address.
2060
2061 In normal kdump cases one does not have to set/change this option
2062 as now bzImage can be compiled as a completely relocatable image
2063 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2064 address. This option is mainly useful for the folks who don't want
2065 to use a bzImage for capturing the crash dump and want to use a
2066 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2067 to be specifically compiled to run from a specific memory area
2068 (normally a reserved region) and this option comes handy.
2069
ceefccc9
PA
2070 So if you are using bzImage for capturing the crash dump,
2071 leave the value here unchanged to 0x1000000 and set
2072 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2073 for capturing the crash dump change this value to start of
2074 the reserved region. In other words, it can be set based on
2075 the "X" value as specified in the "crashkernel=YM@XM"
2076 command line boot parameter passed to the panic-ed
2077 kernel. Please take a look at Documentation/kdump/kdump.txt
2078 for more details about crash dumps.
506f1d07
SR
2079
2080 Usage of bzImage for capturing the crash dump is recommended as
2081 one does not have to build two kernels. Same kernel can be used
2082 as production kernel and capture kernel. Above option should have
2083 gone away after relocatable bzImage support is introduced. But it
2084 is present because there are users out there who continue to use
2085 vmlinux for dump capture. This option should go away down the
2086 line.
2087
2088 Don't change this unless you know what you are doing.
2089
2090config RELOCATABLE
26717808
PA
2091 bool "Build a relocatable kernel"
2092 default y
8f9ca475 2093 ---help---
506f1d07
SR
2094 This builds a kernel image that retains relocation information
2095 so it can be loaded someplace besides the default 1MB.
2096 The relocations tend to make the kernel binary about 10% larger,
2097 but are discarded at runtime.
2098
2099 One use is for the kexec on panic case where the recovery kernel
2100 must live at a different physical address than the primary
2101 kernel.
2102
2103 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2104 it has been loaded at and the compile time physical address
8ab3820f 2105 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2106
8ab3820f 2107config RANDOMIZE_BASE
e8581e3d 2108 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2109 depends on RELOCATABLE
6807c846 2110 default y
8ab3820f 2111 ---help---
e8581e3d
BH
2112 In support of Kernel Address Space Layout Randomization (KASLR),
2113 this randomizes the physical address at which the kernel image
2114 is decompressed and the virtual address where the kernel
2115 image is mapped, as a security feature that deters exploit
2116 attempts relying on knowledge of the location of kernel
2117 code internals.
2118
ed9f007e
KC
2119 On 64-bit, the kernel physical and virtual addresses are
2120 randomized separately. The physical address will be anywhere
2121 between 16MB and the top of physical memory (up to 64TB). The
2122 virtual address will be randomized from 16MB up to 1GB (9 bits
2123 of entropy). Note that this also reduces the memory space
2124 available to kernel modules from 1.5GB to 1GB.
2125
2126 On 32-bit, the kernel physical and virtual addresses are
2127 randomized together. They will be randomized from 16MB up to
2128 512MB (8 bits of entropy).
e8581e3d
BH
2129
2130 Entropy is generated using the RDRAND instruction if it is
2131 supported. If RDTSC is supported, its value is mixed into
2132 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2133 supported, then entropy is read from the i8254 timer. The
2134 usable entropy is limited by the kernel being built using
2135 2GB addressing, and that PHYSICAL_ALIGN must be at a
2136 minimum of 2MB. As a result, only 10 bits of entropy are
2137 theoretically possible, but the implementations are further
2138 limited due to memory layouts.
e8581e3d 2139
6807c846 2140 If unsure, say Y.
8ab3820f
KC
2141
2142# Relocation on x86 needs some additional build support
845adf72
PA
2143config X86_NEED_RELOCS
2144 def_bool y
8ab3820f 2145 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2146
506f1d07 2147config PHYSICAL_ALIGN
a0215061 2148 hex "Alignment value to which kernel should be aligned"
8ab3820f 2149 default "0x200000"
a0215061
KC
2150 range 0x2000 0x1000000 if X86_32
2151 range 0x200000 0x1000000 if X86_64
8f9ca475 2152 ---help---
506f1d07
SR
2153 This value puts the alignment restrictions on physical address
2154 where kernel is loaded and run from. Kernel is compiled for an
2155 address which meets above alignment restriction.
2156
2157 If bootloader loads the kernel at a non-aligned address and
2158 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2159 address aligned to above value and run from there.
2160
2161 If bootloader loads the kernel at a non-aligned address and
2162 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2163 load address and decompress itself to the address it has been
2164 compiled for and run from there. The address for which kernel is
2165 compiled already meets above alignment restrictions. Hence the
2166 end result is that kernel runs from a physical address meeting
2167 above alignment restrictions.
2168
a0215061
KC
2169 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2170 this value must be a multiple of 0x200000.
2171
506f1d07
SR
2172 Don't change this unless you know what you are doing.
2173
eedb92ab
KS
2174config DYNAMIC_MEMORY_LAYOUT
2175 bool
2176 ---help---
2177 This option makes base addresses of vmalloc and vmemmap as well as
2178 __PAGE_OFFSET movable during boot.
2179
0483e1fa
TG
2180config RANDOMIZE_MEMORY
2181 bool "Randomize the kernel memory sections"
2182 depends on X86_64
2183 depends on RANDOMIZE_BASE
eedb92ab 2184 select DYNAMIC_MEMORY_LAYOUT
0483e1fa
TG
2185 default RANDOMIZE_BASE
2186 ---help---
2187 Randomizes the base virtual address of kernel memory sections
2188 (physical memory mapping, vmalloc & vmemmap). This security feature
2189 makes exploits relying on predictable memory locations less reliable.
2190
2191 The order of allocations remains unchanged. Entropy is generated in
2192 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2193 configuration have in average 30,000 different possible virtual
2194 addresses for each memory section.
2195
6807c846 2196 If unsure, say Y.
0483e1fa 2197
90397a41
TG
2198config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2199 hex "Physical memory mapping padding" if EXPERT
2200 depends on RANDOMIZE_MEMORY
2201 default "0xa" if MEMORY_HOTPLUG
2202 default "0x0"
2203 range 0x1 0x40 if MEMORY_HOTPLUG
2204 range 0x0 0x40
2205 ---help---
2206 Define the padding in terabytes added to the existing physical
2207 memory size during kernel memory randomization. It is useful
2208 for memory hotplug support but reduces the entropy available for
2209 address randomization.
2210
2211 If unsure, leave at the default value.
2212
506f1d07 2213config HOTPLUG_CPU
7c13e6a3 2214 bool "Support for hot-pluggable CPUs"
40b31360 2215 depends on SMP
506f1d07 2216 ---help---
7c13e6a3
DS
2217 Say Y here to allow turning CPUs off and on. CPUs can be
2218 controlled through /sys/devices/system/cpu.
2219 ( Note: power management support will enable this option
2220 automatically on SMP systems. )
2221 Say N if you want to disable CPU hotplug.
506f1d07 2222
80aa1dff
FY
2223config BOOTPARAM_HOTPLUG_CPU0
2224 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2225 depends on HOTPLUG_CPU
80aa1dff
FY
2226 ---help---
2227 Set whether default state of cpu0_hotpluggable is on or off.
2228
2229 Say Y here to enable CPU0 hotplug by default. If this switch
2230 is turned on, there is no need to give cpu0_hotplug kernel
2231 parameter and the CPU0 hotplug feature is enabled by default.
2232
2233 Please note: there are two known CPU0 dependencies if you want
2234 to enable the CPU0 hotplug feature either by this switch or by
2235 cpu0_hotplug kernel parameter.
2236
2237 First, resume from hibernate or suspend always starts from CPU0.
2238 So hibernate and suspend are prevented if CPU0 is offline.
2239
2240 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2241 offline if any interrupt can not migrate out of CPU0. There may
2242 be other CPU0 dependencies.
2243
2244 Please make sure the dependencies are under your control before
2245 you enable this feature.
2246
2247 Say N if you don't want to enable CPU0 hotplug feature by default.
2248 You still can enable the CPU0 hotplug feature at boot by kernel
2249 parameter cpu0_hotplug.
2250
a71c8bc5
FY
2251config DEBUG_HOTPLUG_CPU0
2252 def_bool n
2253 prompt "Debug CPU0 hotplug"
2c922cd0 2254 depends on HOTPLUG_CPU
a71c8bc5
FY
2255 ---help---
2256 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2257 soon as possible and boots up userspace with CPU0 offlined. User
2258 can online CPU0 back after boot time.
2259
2260 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2261 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2262 compilation or giving cpu0_hotplug kernel parameter at boot.
2263
2264 If unsure, say N.
2265
506f1d07 2266config COMPAT_VDSO
b0b49f26
AL
2267 def_bool n
2268 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2269 depends on COMPAT_32
8f9ca475 2270 ---help---
b0b49f26
AL
2271 Certain buggy versions of glibc will crash if they are
2272 presented with a 32-bit vDSO that is not mapped at the address
2273 indicated in its segment table.
e84446de 2274
b0b49f26
AL
2275 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2276 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2277 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2278 the only released version with the bug, but OpenSUSE 9
2279 contains a buggy "glibc 2.3.2".
506f1d07 2280
b0b49f26
AL
2281 The symptom of the bug is that everything crashes on startup, saying:
2282 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2283
2284 Saying Y here changes the default value of the vdso32 boot
2285 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2286 This works around the glibc bug but hurts performance.
2287
2288 If unsure, say N: if you are compiling your own kernel, you
2289 are unlikely to be using a buggy version of glibc.
506f1d07 2290
3dc33bd3
KC
2291choice
2292 prompt "vsyscall table for legacy applications"
2293 depends on X86_64
2294 default LEGACY_VSYSCALL_EMULATE
2295 help
2296 Legacy user code that does not know how to find the vDSO expects
2297 to be able to issue three syscalls by calling fixed addresses in
2298 kernel space. Since this location is not randomized with ASLR,
2299 it can be used to assist security vulnerability exploitation.
2300
2301 This setting can be changed at boot time via the kernel command
076ca272 2302 line parameter vsyscall=[emulate|none].
3dc33bd3
KC
2303
2304 On a system with recent enough glibc (2.14 or newer) and no
2305 static binaries, you can say None without a performance penalty
2306 to improve security.
2307
2308 If unsure, select "Emulate".
2309
3dc33bd3
KC
2310 config LEGACY_VSYSCALL_EMULATE
2311 bool "Emulate"
2312 help
2313 The kernel traps and emulates calls into the fixed
2314 vsyscall address mapping. This makes the mapping
2315 non-executable, but it still contains known contents,
2316 which could be used in certain rare security vulnerability
2317 exploits. This configuration is recommended when userspace
2318 still uses the vsyscall area.
2319
2320 config LEGACY_VSYSCALL_NONE
2321 bool "None"
2322 help
2323 There will be no vsyscall mapping at all. This will
2324 eliminate any risk of ASLR bypass due to the vsyscall
2325 fixed address mapping. Attempts to use the vsyscalls
2326 will be reported to dmesg, so that either old or
2327 malicious userspace programs can be identified.
2328
2329endchoice
2330
516cbf37
TB
2331config CMDLINE_BOOL
2332 bool "Built-in kernel command line"
8f9ca475 2333 ---help---
516cbf37
TB
2334 Allow for specifying boot arguments to the kernel at
2335 build time. On some systems (e.g. embedded ones), it is
2336 necessary or convenient to provide some or all of the
2337 kernel boot arguments with the kernel itself (that is,
2338 to not rely on the boot loader to provide them.)
2339
2340 To compile command line arguments into the kernel,
2341 set this option to 'Y', then fill in the
69711ca1 2342 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2343
2344 Systems with fully functional boot loaders (i.e. non-embedded)
2345 should leave this option set to 'N'.
2346
2347config CMDLINE
2348 string "Built-in kernel command string"
2349 depends on CMDLINE_BOOL
2350 default ""
8f9ca475 2351 ---help---
516cbf37
TB
2352 Enter arguments here that should be compiled into the kernel
2353 image and used at boot time. If the boot loader provides a
2354 command line at boot time, it is appended to this string to
2355 form the full kernel command line, when the system boots.
2356
2357 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2358 change this behavior.
2359
2360 In most cases, the command line (whether built-in or provided
2361 by the boot loader) should specify the device for the root
2362 file system.
2363
2364config CMDLINE_OVERRIDE
2365 bool "Built-in command line overrides boot loader arguments"
516cbf37 2366 depends on CMDLINE_BOOL
8f9ca475 2367 ---help---
516cbf37
TB
2368 Set this option to 'Y' to have the kernel ignore the boot loader
2369 command line, and use ONLY the built-in command line.
2370
2371 This is used to work around broken boot loaders. This should
2372 be set to 'N' under normal conditions.
2373
a5b9e5a2
AL
2374config MODIFY_LDT_SYSCALL
2375 bool "Enable the LDT (local descriptor table)" if EXPERT
2376 default y
2377 ---help---
2378 Linux can allow user programs to install a per-process x86
2379 Local Descriptor Table (LDT) using the modify_ldt(2) system
2380 call. This is required to run 16-bit or segmented code such as
2381 DOSEMU or some Wine programs. It is also used by some very old
2382 threading libraries.
2383
2384 Enabling this feature adds a small amount of overhead to
2385 context switches and increases the low-level kernel attack
2386 surface. Disabling it removes the modify_ldt(2) system call.
2387
2388 Saying 'N' here may make sense for embedded or server kernels.
2389
b700e7f0
SJ
2390source "kernel/livepatch/Kconfig"
2391
506f1d07
SR
2392endmenu
2393
3072e413
MH
2394config ARCH_HAS_ADD_PAGES
2395 def_bool y
2396 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2397
506f1d07
SR
2398config ARCH_ENABLE_MEMORY_HOTPLUG
2399 def_bool y
2400 depends on X86_64 || (X86_32 && HIGHMEM)
2401
35551053
GH
2402config ARCH_ENABLE_MEMORY_HOTREMOVE
2403 def_bool y
2404 depends on MEMORY_HOTPLUG
2405
e534c7c5 2406config USE_PERCPU_NUMA_NODE_ID
645a7919 2407 def_bool y
e534c7c5
LS
2408 depends on NUMA
2409
9491846f
KS
2410config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2411 def_bool y
2412 depends on X86_64 || X86_PAE
2413
c177c81e
NH
2414config ARCH_ENABLE_HUGEPAGE_MIGRATION
2415 def_bool y
2416 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2417
9c670ea3
NH
2418config ARCH_ENABLE_THP_MIGRATION
2419 def_bool y
2420 depends on X86_64 && TRANSPARENT_HUGEPAGE
2421
da85f865 2422menu "Power management and ACPI options"
e279b6c1
SR
2423
2424config ARCH_HIBERNATION_HEADER
3c2362e6 2425 def_bool y
44556530 2426 depends on HIBERNATION
e279b6c1
SR
2427
2428source "kernel/power/Kconfig"
2429
2430source "drivers/acpi/Kconfig"
2431
efafc8b2
FT
2432source "drivers/sfi/Kconfig"
2433
a6b68076 2434config X86_APM_BOOT
6fc108a0 2435 def_bool y
282e5aab 2436 depends on APM
a6b68076 2437
e279b6c1
SR
2438menuconfig APM
2439 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2440 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2441 ---help---
2442 APM is a BIOS specification for saving power using several different
2443 techniques. This is mostly useful for battery powered laptops with
2444 APM compliant BIOSes. If you say Y here, the system time will be
2445 reset after a RESUME operation, the /proc/apm device will provide
2446 battery status information, and user-space programs will receive
2447 notification of APM "events" (e.g. battery status change).
2448
2449 If you select "Y" here, you can disable actual use of the APM
2450 BIOS by passing the "apm=off" option to the kernel at boot time.
2451
2452 Note that the APM support is almost completely disabled for
2453 machines with more than one CPU.
2454
2455 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2456 and more information, read <file:Documentation/power/apm-acpi.txt>
2457 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2458 <http://www.tldp.org/docs.html#howto>.
2459
2460 This driver does not spin down disk drives (see the hdparm(8)
2461 manpage ("man 8 hdparm") for that), and it doesn't turn off
2462 VESA-compliant "green" monitors.
2463
2464 This driver does not support the TI 4000M TravelMate and the ACER
2465 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2466 desktop machines also don't have compliant BIOSes, and this driver
2467 may cause those machines to panic during the boot phase.
2468
2469 Generally, if you don't have a battery in your machine, there isn't
2470 much point in using this driver and you should say N. If you get
2471 random kernel OOPSes or reboots that don't seem to be related to
2472 anything, try disabling/enabling this option (or disabling/enabling
2473 APM in your BIOS).
2474
2475 Some other things you should try when experiencing seemingly random,
2476 "weird" problems:
2477
2478 1) make sure that you have enough swap space and that it is
2479 enabled.
2480 2) pass the "no-hlt" option to the kernel
2481 3) switch on floating point emulation in the kernel and pass
2482 the "no387" option to the kernel
2483 4) pass the "floppy=nodma" option to the kernel
2484 5) pass the "mem=4M" option to the kernel (thereby disabling
2485 all but the first 4 MB of RAM)
2486 6) make sure that the CPU is not over clocked.
2487 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2488 8) disable the cache from your BIOS settings
2489 9) install a fan for the video card or exchange video RAM
2490 10) install a better fan for the CPU
2491 11) exchange RAM chips
2492 12) exchange the motherboard.
2493
2494 To compile this driver as a module, choose M here: the
2495 module will be called apm.
2496
2497if APM
2498
2499config APM_IGNORE_USER_SUSPEND
2500 bool "Ignore USER SUSPEND"
8f9ca475 2501 ---help---
e279b6c1
SR
2502 This option will ignore USER SUSPEND requests. On machines with a
2503 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2504 series notebooks, it is necessary to say Y because of a BIOS bug.
2505
2506config APM_DO_ENABLE
2507 bool "Enable PM at boot time"
2508 ---help---
2509 Enable APM features at boot time. From page 36 of the APM BIOS
2510 specification: "When disabled, the APM BIOS does not automatically
2511 power manage devices, enter the Standby State, enter the Suspend
2512 State, or take power saving steps in response to CPU Idle calls."
2513 This driver will make CPU Idle calls when Linux is idle (unless this
2514 feature is turned off -- see "Do CPU IDLE calls", below). This
2515 should always save battery power, but more complicated APM features
2516 will be dependent on your BIOS implementation. You may need to turn
2517 this option off if your computer hangs at boot time when using APM
2518 support, or if it beeps continuously instead of suspending. Turn
2519 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2520 T400CDT. This is off by default since most machines do fine without
2521 this feature.
2522
2523config APM_CPU_IDLE
dd8af076 2524 depends on CPU_IDLE
e279b6c1 2525 bool "Make CPU Idle calls when idle"
8f9ca475 2526 ---help---
e279b6c1
SR
2527 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2528 On some machines, this can activate improved power savings, such as
2529 a slowed CPU clock rate, when the machine is idle. These idle calls
2530 are made after the idle loop has run for some length of time (e.g.,
2531 333 mS). On some machines, this will cause a hang at boot time or
2532 whenever the CPU becomes idle. (On machines with more than one CPU,
2533 this option does nothing.)
2534
2535config APM_DISPLAY_BLANK
2536 bool "Enable console blanking using APM"
8f9ca475 2537 ---help---
e279b6c1
SR
2538 Enable console blanking using the APM. Some laptops can use this to
2539 turn off the LCD backlight when the screen blanker of the Linux
2540 virtual console blanks the screen. Note that this is only used by
2541 the virtual console screen blanker, and won't turn off the backlight
2542 when using the X Window system. This also doesn't have anything to
2543 do with your VESA-compliant power-saving monitor. Further, this
2544 option doesn't work for all laptops -- it might not turn off your
2545 backlight at all, or it might print a lot of errors to the console,
2546 especially if you are using gpm.
2547
2548config APM_ALLOW_INTS
2549 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2550 ---help---
e279b6c1
SR
2551 Normally we disable external interrupts while we are making calls to
2552 the APM BIOS as a measure to lessen the effects of a badly behaving
2553 BIOS implementation. The BIOS should reenable interrupts if it
2554 needs to. Unfortunately, some BIOSes do not -- especially those in
2555 many of the newer IBM Thinkpads. If you experience hangs when you
2556 suspend, try setting this to Y. Otherwise, say N.
2557
e279b6c1
SR
2558endif # APM
2559
bb0a56ec 2560source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2561
2562source "drivers/cpuidle/Kconfig"
2563
27471fdb
AH
2564source "drivers/idle/Kconfig"
2565
e279b6c1
SR
2566endmenu
2567
2568
2569menu "Bus options (PCI etc.)"
2570
2571config PCI
1ac97018 2572 bool "PCI support"
1c858087 2573 default y
8f9ca475 2574 ---help---
e279b6c1
SR
2575 Find out whether you have a PCI motherboard. PCI is the name of a
2576 bus system, i.e. the way the CPU talks to the other stuff inside
2577 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2578 VESA. If you have PCI, say Y, otherwise N.
2579
e279b6c1
SR
2580choice
2581 prompt "PCI access mode"
efefa6f6 2582 depends on X86_32 && PCI
e279b6c1
SR
2583 default PCI_GOANY
2584 ---help---
2585 On PCI systems, the BIOS can be used to detect the PCI devices and
2586 determine their configuration. However, some old PCI motherboards
2587 have BIOS bugs and may crash if this is done. Also, some embedded
2588 PCI-based systems don't have any BIOS at all. Linux can also try to
2589 detect the PCI hardware directly without using the BIOS.
2590
2591 With this option, you can specify how Linux should detect the
2592 PCI devices. If you choose "BIOS", the BIOS will be used,
2593 if you choose "Direct", the BIOS won't be used, and if you
2594 choose "MMConfig", then PCI Express MMCONFIG will be used.
2595 If you choose "Any", the kernel will try MMCONFIG, then the
2596 direct access method and falls back to the BIOS if that doesn't
2597 work. If unsure, go with the default, which is "Any".
2598
2599config PCI_GOBIOS
2600 bool "BIOS"
2601
2602config PCI_GOMMCONFIG
2603 bool "MMConfig"
2604
2605config PCI_GODIRECT
2606 bool "Direct"
2607
3ef0e1f8 2608config PCI_GOOLPC
76fb6570 2609 bool "OLPC XO-1"
3ef0e1f8
AS
2610 depends on OLPC
2611
2bdd1b03
AS
2612config PCI_GOANY
2613 bool "Any"
2614
e279b6c1
SR
2615endchoice
2616
2617config PCI_BIOS
3c2362e6 2618 def_bool y
efefa6f6 2619 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2620
2621# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2622config PCI_DIRECT
3c2362e6 2623 def_bool y
0aba496f 2624 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2625
2626config PCI_MMCONFIG
b45c9f36
JK
2627 bool "Support mmconfig PCI config space access" if X86_64
2628 default y
8364e1f8 2629 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2630 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2631
3ef0e1f8 2632config PCI_OLPC
2bdd1b03
AS
2633 def_bool y
2634 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2635
b5401a96
AN
2636config PCI_XEN
2637 def_bool y
2638 depends on PCI && XEN
2639 select SWIOTLB_XEN
2640
e279b6c1 2641config PCI_DOMAINS
3c2362e6 2642 def_bool y
e279b6c1 2643 depends on PCI
e279b6c1 2644
8364e1f8
JK
2645config MMCONF_FAM10H
2646 def_bool y
2647 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2648
3f6ea84a 2649config PCI_CNB20LE_QUIRK
6a108a14 2650 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2651 depends on PCI
3f6ea84a
IS
2652 help
2653 Read the PCI windows out of the CNB20LE host bridge. This allows
2654 PCI hotplug to work on systems with the CNB20LE chipset which do
2655 not have ACPI.
2656
64a5fed6
BH
2657 There's no public spec for this chipset, and this functionality
2658 is known to be incomplete.
2659
2660 You should say N unless you know you need this.
2661
e279b6c1
SR
2662source "drivers/pci/Kconfig"
2663
3a495511 2664config ISA_BUS
17a2a129 2665 bool "ISA bus support on modern systems" if EXPERT
3a495511 2666 help
17a2a129
WBG
2667 Expose ISA bus device drivers and options available for selection and
2668 configuration. Enable this option if your target machine has an ISA
2669 bus. ISA is an older system, displaced by PCI and newer bus
2670 architectures -- if your target machine is modern, it probably does
2671 not have an ISA bus.
3a495511
WBG
2672
2673 If unsure, say N.
2674
1c00f016 2675# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2676config ISA_DMA_API
1c00f016
DR
2677 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2678 default y
2679 help
2680 Enables ISA-style DMA support for devices requiring such controllers.
2681 If unsure, say Y.
e279b6c1 2682
51e68d05
LT
2683if X86_32
2684
e279b6c1
SR
2685config ISA
2686 bool "ISA support"
8f9ca475 2687 ---help---
e279b6c1
SR
2688 Find out whether you have ISA slots on your motherboard. ISA is the
2689 name of a bus system, i.e. the way the CPU talks to the other stuff
2690 inside your box. Other bus systems are PCI, EISA, MicroChannel
2691 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2692 newer boards don't support it. If you have ISA, say Y, otherwise N.
2693
2694config EISA
2695 bool "EISA support"
2696 depends on ISA
2697 ---help---
2698 The Extended Industry Standard Architecture (EISA) bus was
2699 developed as an open alternative to the IBM MicroChannel bus.
2700
2701 The EISA bus provided some of the features of the IBM MicroChannel
2702 bus while maintaining backward compatibility with cards made for
2703 the older ISA bus. The EISA bus saw limited use between 1988 and
2704 1995 when it was made obsolete by the PCI bus.
2705
2706 Say Y here if you are building a kernel for an EISA-based machine.
2707
2708 Otherwise, say N.
2709
2710source "drivers/eisa/Kconfig"
2711
e279b6c1
SR
2712config SCx200
2713 tristate "NatSemi SCx200 support"
8f9ca475 2714 ---help---
e279b6c1
SR
2715 This provides basic support for National Semiconductor's
2716 (now AMD's) Geode processors. The driver probes for the
2717 PCI-IDs of several on-chip devices, so its a good dependency
2718 for other scx200_* drivers.
2719
2720 If compiled as a module, the driver is named scx200.
2721
2722config SCx200HR_TIMER
2723 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2724 depends on SCx200
e279b6c1 2725 default y
8f9ca475 2726 ---help---
e279b6c1
SR
2727 This driver provides a clocksource built upon the on-chip
2728 27MHz high-resolution timer. Its also a workaround for
2729 NSC Geode SC-1100's buggy TSC, which loses time when the
2730 processor goes idle (as is done by the scheduler). The
2731 other workaround is idle=poll boot option.
2732
3ef0e1f8
AS
2733config OLPC
2734 bool "One Laptop Per Child support"
54008979 2735 depends on !X86_PAE
3c554946 2736 select GPIOLIB
dc3119e7 2737 select OF
45bb1674 2738 select OF_PROMTREE
b4e51854 2739 select IRQ_DOMAIN
8f9ca475 2740 ---help---
3ef0e1f8
AS
2741 Add support for detecting the unique features of the OLPC
2742 XO hardware.
2743
a3128588
DD
2744config OLPC_XO1_PM
2745 bool "OLPC XO-1 Power Management"
fa112cf1 2746 depends on OLPC && MFD_CS5535=y && PM_SLEEP
bf1ebf00 2747 ---help---
97c4cb71 2748 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2749
cfee9597
DD
2750config OLPC_XO1_RTC
2751 bool "OLPC XO-1 Real Time Clock"
2752 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2753 ---help---
2754 Add support for the XO-1 real time clock, which can be used as a
2755 programmable wakeup source.
2756
7feda8e9
DD
2757config OLPC_XO1_SCI
2758 bool "OLPC XO-1 SCI extras"
92e830f2 2759 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2760 depends on INPUT=y
d8d01a63 2761 select POWER_SUPPLY
7feda8e9
DD
2762 ---help---
2763 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2764 - EC-driven system wakeups
7feda8e9 2765 - Power button
7bc74b3d 2766 - Ebook switch
2cf2baea 2767 - Lid switch
e1040ac6
DD
2768 - AC adapter status updates
2769 - Battery status updates
7feda8e9 2770
a0f30f59
DD
2771config OLPC_XO15_SCI
2772 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2773 depends on OLPC && ACPI
2774 select POWER_SUPPLY
a0f30f59
DD
2775 ---help---
2776 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2777 - EC-driven system wakeups
2778 - AC adapter status updates
2779 - Battery status updates
bf1ebf00 2780
d4f3e350
EW
2781config ALIX
2782 bool "PCEngines ALIX System Support (LED setup)"
2783 select GPIOLIB
2784 ---help---
2785 This option enables system support for the PCEngines ALIX.
2786 At present this just sets up LEDs for GPIO control on
2787 ALIX2/3/6 boards. However, other system specific setup should
2788 get added here.
2789
2790 Note: You must still enable the drivers for GPIO and LED support
2791 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2792
2793 Note: You have to set alix.force=1 for boards with Award BIOS.
2794
da4e3302
PP
2795config NET5501
2796 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2797 select GPIOLIB
2798 ---help---
2799 This option enables system support for the Soekris Engineering net5501.
2800
3197059a
PP
2801config GEOS
2802 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2803 select GPIOLIB
2804 depends on DMI
2805 ---help---
2806 This option enables system support for the Traverse Technologies GEOS.
2807
7d029125
VD
2808config TS5500
2809 bool "Technologic Systems TS-5500 platform support"
2810 depends on MELAN
2811 select CHECK_SIGNATURE
2812 select NEW_LEDS
2813 select LEDS_CLASS
2814 ---help---
2815 This option enables system support for the Technologic Systems TS-5500.
2816
bc0120fd
SR
2817endif # X86_32
2818
23ac4ae8 2819config AMD_NB
e279b6c1 2820 def_bool y
0e152cd7 2821 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2822
2823source "drivers/pcmcia/Kconfig"
2824
388b78ad 2825config RAPIDIO
fdf90abc 2826 tristate "RapidIO support"
388b78ad 2827 depends on PCI
388b78ad 2828 help
fdf90abc 2829 If enabled this option will include drivers and the core
388b78ad
AB
2830 infrastructure code to support RapidIO interconnect devices.
2831
2832source "drivers/rapidio/Kconfig"
2833
e3263ab3
DR
2834config X86_SYSFB
2835 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2836 help
2837 Firmwares often provide initial graphics framebuffers so the BIOS,
2838 bootloader or kernel can show basic video-output during boot for
2839 user-guidance and debugging. Historically, x86 used the VESA BIOS
2840 Extensions and EFI-framebuffers for this, which are mostly limited
2841 to x86.
2842 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2843 framebuffers so the new generic system-framebuffer drivers can be
2844 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2845 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DR
2846 drivers like efifb, vesafb and uvesafb can pick it up.
2847 If this option is not selected, all system framebuffers are always
2848 marked as fallback platform framebuffers as usual.
2849
2850 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2851 not be able to pick up generic system framebuffers if this option
2852 is selected. You are highly encouraged to enable simplefb as
2853 replacement if you select this option. simplefb can correctly deal
2854 with generic system framebuffers. But you should still keep vesafb
2855 and others enabled as fallback if a system framebuffer is
2856 incompatible with simplefb.
2857
2858 If unsure, say Y.
2859
e279b6c1
SR
2860endmenu
2861
2862
1572497c 2863menu "Binary Emulations"
e279b6c1
SR
2864
2865config IA32_EMULATION
2866 bool "IA32 Emulation"
2867 depends on X86_64
39f88911 2868 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2869 select BINFMT_ELF
a97f52e6 2870 select COMPAT_BINFMT_ELF
39f88911 2871 select COMPAT_OLD_SIGACTION
8f9ca475 2872 ---help---
5fd92e65
L
2873 Include code to run legacy 32-bit programs under a
2874 64-bit kernel. You should likely turn this on, unless you're
2875 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2876
2877config IA32_AOUT
8f9ca475
IM
2878 tristate "IA32 a.out support"
2879 depends on IA32_EMULATION
2880 ---help---
2881 Support old a.out binaries in the 32bit emulation.
e279b6c1 2882
0bf62763 2883config X86_X32
6ea30386 2884 bool "x32 ABI for 64-bit mode"
9b54050b 2885 depends on X86_64
5fd92e65
L
2886 ---help---
2887 Include code to run binaries for the x32 native 32-bit ABI
2888 for 64-bit processors. An x32 process gets access to the
2889 full 64-bit register file and wide data path while leaving
2890 pointers at 32 bits for smaller memory footprint.
2891
2892 You will need a recent binutils (2.22 or later) with
2893 elf32_x86_64 support enabled to compile a kernel with this
2894 option set.
2895
953fee1d
IM
2896config COMPAT_32
2897 def_bool y
2898 depends on IA32_EMULATION || X86_32
2899 select HAVE_UID16
2900 select OLD_SIGSUSPEND3
2901
e279b6c1 2902config COMPAT
3c2362e6 2903 def_bool y
0bf62763 2904 depends on IA32_EMULATION || X86_X32
e279b6c1 2905
3120e25e 2906if COMPAT
e279b6c1 2907config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2908 def_bool y
e279b6c1
SR
2909
2910config SYSVIPC_COMPAT
3c2362e6 2911 def_bool y
3120e25e 2912 depends on SYSVIPC
3120e25e 2913endif
ee009e4a 2914
e279b6c1
SR
2915endmenu
2916
2917
e5beae16
KP
2918config HAVE_ATOMIC_IOMAP
2919 def_bool y
2920 depends on X86_32
2921
4692d77f
AR
2922config X86_DEV_DMA_OPS
2923 bool
83125a3a 2924 depends on X86_64 || STA2X11
4692d77f 2925
f7219a53
AR
2926config X86_DMA_REMAP
2927 bool
83125a3a 2928 depends on STA2X11
f7219a53 2929
e585513b
KS
2930config HAVE_GENERIC_GUP
2931 def_bool y
2932
e279b6c1
SR
2933source "drivers/firmware/Kconfig"
2934
edf88417 2935source "arch/x86/kvm/Kconfig"