mm/vmstat.c: standardize file operations variable names
[linux-2.6-block.git] / arch / x86 / Kconfig
CommitLineData
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1# Select 32 or 64 bit
2config 64BIT
6840999b 3 bool "64-bit kernel" if ARCH = "x86"
ffee0de4 4 default ARCH != "i386"
8f9ca475 5 ---help---
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6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
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10 def_bool y
11 depends on !64BIT
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12 # Options that are inherently 32-bit kernel only:
13 select ARCH_WANT_IPC_PARSE_VERSION
14 select CLKSRC_I8253
15 select CLONE_BACKWARDS
16 select HAVE_AOUT
17 select HAVE_GENERIC_DMA_COHERENT
18 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
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20
21config X86_64
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22 def_bool y
23 depends on 64BIT
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24 # Options that are inherently 64-bit kernel only:
25 select ARCH_HAS_GIGANTIC_PAGE
26 select ARCH_SUPPORTS_INT128
27 select ARCH_USE_CMPXCHG_LOCKREF
28 select HAVE_ARCH_SOFT_DIRTY
29 select MODULES_USE_ELF_RELA
30 select X86_DEV_DMA_OPS
1032c0ba 31
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32#
33# Arch settings
34#
35# ( Note that options that are marked 'if X86_64' could in principle be
36# ported to 32-bit as well. )
37#
8d5fffb9 38config X86
3c2362e6 39 def_bool y
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40 #
41 # Note: keep this list sorted alphabetically
42 #
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43 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
44 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
45 select ANON_INODES
46 select ARCH_CLOCKSOURCE_DATA
47 select ARCH_DISCARD_MEMBLOCK
c763ea26 48 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 49 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 50 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 51 select ARCH_HAS_ELF_RANDOMIZE
72d93104 52 select ARCH_HAS_FAST_MULTIPLIER
957e3fac 53 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 54 select ARCH_HAS_KCOV if X86_64
67a3e8fe 55 select ARCH_HAS_MMIO_FLUSH
c763ea26 56 select ARCH_HAS_PMEM_API if X86_64
d2852a22 57 select ARCH_HAS_SET_MEMORY
6471b825 58 select ARCH_HAS_SG_CHAIN
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59 select ARCH_HAS_STRICT_KERNEL_RWX
60 select ARCH_HAS_STRICT_MODULE_RWX
c6d30853 61 select ARCH_HAS_UBSAN_SANITIZE_ALL
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62 select ARCH_HAVE_NMI_SAFE_CMPXCHG
63 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 64 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 65 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 66 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 67 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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68 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
69 select ARCH_USE_BUILTIN_BSWAP
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70 select ARCH_USE_QUEUED_RWLOCKS
71 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 72 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
da4276b8 73 select ARCH_WANT_FRAME_POINTERS
c763ea26 74 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
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75 select BUILDTIME_EXTABLE_SORT
76 select CLKEVT_I8253
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77 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
78 select CLOCKSOURCE_WATCHDOG
6471b825 79 select DCACHE_WORD_ACCESS
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80 select EDAC_ATOMIC_SCRUB
81 select EDAC_SUPPORT
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82 select GENERIC_CLOCKEVENTS
83 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
84 select GENERIC_CLOCKEVENTS_MIN_ADJUST
85 select GENERIC_CMOS_UPDATE
86 select GENERIC_CPU_AUTOPROBE
5b7c73e0 87 select GENERIC_EARLY_IOREMAP
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88 select GENERIC_FIND_FIRST_BIT
89 select GENERIC_IOMAP
c7d6c9dd 90 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
ad7a929f 91 select GENERIC_IRQ_MIGRATION if SMP
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92 select GENERIC_IRQ_PROBE
93 select GENERIC_IRQ_SHOW
94 select GENERIC_PENDING_IRQ if SMP
95 select GENERIC_SMP_IDLE_THREAD
96 select GENERIC_STRNCPY_FROM_USER
97 select GENERIC_STRNLEN_USER
98 select GENERIC_TIME_VSYSCALL
99 select HAVE_ACPI_APEI if ACPI
100 select HAVE_ACPI_APEI_NMI if ACPI
101 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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102 select HAVE_ARCH_AUDITSYSCALL
103 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
104 select HAVE_ARCH_JUMP_LABEL
105 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
106 select HAVE_ARCH_KGDB
107 select HAVE_ARCH_KMEMCHECK
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108 select HAVE_ARCH_MMAP_RND_BITS if MMU
109 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 110 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
6471b825 111 select HAVE_ARCH_SECCOMP_FILTER
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112 select HAVE_ARCH_TRACEHOOK
113 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 114 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 115 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 116 select HAVE_ARCH_WITHIN_STACK_FRAMES
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117 select HAVE_CC_STACKPROTECTOR
118 select HAVE_CMPXCHG_DOUBLE
119 select HAVE_CMPXCHG_LOCAL
120 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 121 select HAVE_COPY_THREAD_TLS
cf4db259 122 select HAVE_C_RECORDMCOUNT
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123 select HAVE_DEBUG_KMEMLEAK
124 select HAVE_DEBUG_STACKOVERFLOW
125 select HAVE_DMA_API_DEBUG
6471b825 126 select HAVE_DMA_CONTIGUOUS
677aa9f7 127 select HAVE_DYNAMIC_FTRACE
06aeaaea 128 select HAVE_DYNAMIC_FTRACE_WITH_REGS
c763ea26 129 select HAVE_EBPF_JIT if X86_64
58340a07 130 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 131 select HAVE_EXIT_THREAD
644e0e8d 132 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 133 select HAVE_FTRACE_MCOUNT_RECORD
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134 select HAVE_FUNCTION_GRAPH_TRACER
135 select HAVE_FUNCTION_TRACER
6b90bd4b 136 select HAVE_GCC_PLUGINS
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137 select HAVE_HW_BREAKPOINT
138 select HAVE_IDE
139 select HAVE_IOREMAP_PROT
140 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
141 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 142 select HAVE_KERNEL_BZIP2
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143 select HAVE_KERNEL_GZIP
144 select HAVE_KERNEL_LZ4
2e9f3bdd 145 select HAVE_KERNEL_LZMA
13510997 146 select HAVE_KERNEL_LZO
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147 select HAVE_KERNEL_XZ
148 select HAVE_KPROBES
149 select HAVE_KPROBES_ON_FTRACE
150 select HAVE_KRETPROBES
151 select HAVE_KVM
152 select HAVE_LIVEPATCH if X86_64
153 select HAVE_MEMBLOCK
154 select HAVE_MEMBLOCK_NODE_MAP
0102752e 155 select HAVE_MIXED_BREAKPOINTS_REGS
42a0bb3f 156 select HAVE_NMI
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157 select HAVE_OPROFILE
158 select HAVE_OPTPROBES
159 select HAVE_PCSPKR_PLATFORM
160 select HAVE_PERF_EVENTS
c01d4323 161 select HAVE_PERF_EVENTS_NMI
c5e63197 162 select HAVE_PERF_REGS
c5ebcedb 163 select HAVE_PERF_USER_STACK_DUMP
6471b825 164 select HAVE_REGS_AND_STACK_ACCESS_API
af085d90 165 select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER && STACK_VALIDATION
c763ea26 166 select HAVE_STACK_VALIDATION if X86_64
6471b825 167 select HAVE_SYSCALL_TRACEPOINTS
6471b825 168 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 169 select HAVE_USER_RETURN_NOTIFIER
c0185808 170 select IRQ_FORCED_THREADING
df65c1bc 171 select PCI_LOCKLESS_CONFIG
6471b825 172 select PERF_EVENTS
3195ef59 173 select RTC_LIB
d6faca40 174 select RTC_MC146818_LIB
6471b825 175 select SPARSE_IRQ
83fe27ea 176 select SRCU
6471b825 177 select SYSCTL_EXCEPTION_TRACE
15f4eae7 178 select THREAD_INFO_IN_TASK
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179 select USER_STACKTRACE_SUPPORT
180 select VIRT_TO_BUS
6471b825 181 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 182
ba7e4d13 183config INSTRUCTION_DECODER
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184 def_bool y
185 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 186
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187config OUTPUT_FORMAT
188 string
189 default "elf32-i386" if X86_32
190 default "elf64-x86-64" if X86_64
191
73531905 192config ARCH_DEFCONFIG
b9b39bfb 193 string
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194 default "arch/x86/configs/i386_defconfig" if X86_32
195 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 196
8d5fffb9 197config LOCKDEP_SUPPORT
3c2362e6 198 def_bool y
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199
200config STACKTRACE_SUPPORT
3c2362e6 201 def_bool y
8d5fffb9 202
8d5fffb9 203config MMU
3c2362e6 204 def_bool y
8d5fffb9 205
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206config ARCH_MMAP_RND_BITS_MIN
207 default 28 if 64BIT
208 default 8
209
210config ARCH_MMAP_RND_BITS_MAX
211 default 32 if 64BIT
212 default 16
213
214config ARCH_MMAP_RND_COMPAT_BITS_MIN
215 default 8
216
217config ARCH_MMAP_RND_COMPAT_BITS_MAX
218 default 16
219
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220config SBUS
221 bool
222
3bc4e459 223config NEED_DMA_MAP_STATE
3120e25e 224 def_bool y
a6dfa128 225 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 226
18e98307 227config NEED_SG_DMA_LENGTH
4a14d84e 228 def_bool y
18e98307 229
8d5fffb9 230config GENERIC_ISA_DMA
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231 def_bool y
232 depends on ISA_DMA_API
8d5fffb9 233
8d5fffb9 234config GENERIC_BUG
3c2362e6 235 def_bool y
8d5fffb9 236 depends on BUG
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237 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
238
239config GENERIC_BUG_RELATIVE_POINTERS
240 bool
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241
242config GENERIC_HWEIGHT
3c2362e6 243 def_bool y
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244
245config ARCH_MAY_HAVE_PC_FDC
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246 def_bool y
247 depends on ISA_DMA_API
8d5fffb9 248
1032c0ba 249config RWSEM_XCHGADD_ALGORITHM
3120e25e 250 def_bool y
1032c0ba 251
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252config GENERIC_CALIBRATE_DELAY
253 def_bool y
254
9a0b8415 255config ARCH_HAS_CPU_RELAX
256 def_bool y
257
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258config ARCH_HAS_CACHE_LINE_SIZE
259 def_bool y
260
dd5af90a 261config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 262 def_bool y
b32ef636 263
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264config NEED_PER_CPU_EMBED_FIRST_CHUNK
265 def_bool y
266
267config NEED_PER_CPU_PAGE_FIRST_CHUNK
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268 def_bool y
269
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270config ARCH_HIBERNATION_POSSIBLE
271 def_bool y
801e4062 272
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273config ARCH_SUSPEND_POSSIBLE
274 def_bool y
f4cb5700 275
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276config ARCH_WANT_HUGE_PMD_SHARE
277 def_bool y
278
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279config ARCH_WANT_GENERAL_HUGETLB
280 def_bool y
281
8d5fffb9 282config ZONE_DMA32
e0fd24a3 283 def_bool y if X86_64
8d5fffb9 284
8d5fffb9 285config AUDIT_ARCH
e0fd24a3 286 def_bool y if X86_64
8d5fffb9 287
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288config ARCH_SUPPORTS_OPTIMIZED_INLINING
289 def_bool y
290
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291config ARCH_SUPPORTS_DEBUG_PAGEALLOC
292 def_bool y
293
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294config KASAN_SHADOW_OFFSET
295 hex
296 depends on KASAN
4c7c4483 297 default 0xdff8000000000000 if X86_5LEVEL
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298 default 0xdffffc0000000000
299
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300config HAVE_INTEL_TXT
301 def_bool y
6ea30386 302 depends on INTEL_IOMMU && ACPI
69575d38 303
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304config X86_32_SMP
305 def_bool y
306 depends on X86_32 && SMP
307
308config X86_64_SMP
309 def_bool y
310 depends on X86_64 && SMP
311
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312config X86_32_LAZY_GS
313 def_bool y
60a5317f 314 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 315
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316config ARCH_SUPPORTS_UPROBES
317 def_bool y
318
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319config FIX_EARLYCON_MEM
320 def_bool y
321
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322config PGTABLE_LEVELS
323 int
324 default 4 if X86_64
325 default 3 if X86_PAE
326 default 2
327
506f1d07 328source "init/Kconfig"
dc52ddc0 329source "kernel/Kconfig.freezer"
8d5fffb9 330
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331menu "Processor type and features"
332
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333config ZONE_DMA
334 bool "DMA memory allocation support" if EXPERT
335 default y
336 help
337 DMA memory allocation support allows devices with less than 32-bit
338 addressing to allocate within the first 16MB of address space.
339 Disable if no such devices will be used.
340
341 If unsure, say Y.
342
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343config SMP
344 bool "Symmetric multi-processing support"
345 ---help---
346 This enables support for systems with more than one CPU. If you have
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347 a system with only one CPU, say N. If you have a system with more
348 than one CPU, say Y.
506f1d07 349
4a474157 350 If you say N here, the kernel will run on uni- and multiprocessor
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351 machines, but will use only one CPU of a multiprocessor machine. If
352 you say Y here, the kernel will run on many, but not all,
4a474157 353 uniprocessor machines. On a uniprocessor machine, the kernel
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SR
354 will run faster if you say N here.
355
356 Note that if you say Y here and choose architecture "586" or
357 "Pentium" under "Processor family", the kernel will not work on 486
358 architectures. Similarly, multiprocessor kernels for the "PPro"
359 architecture may not work on all Pentium based boards.
360
361 People using multiprocessor machines who say Y here should also say
362 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
363 Management" code will be disabled if you say Y here.
364
395cf969 365 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 366 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
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367 <http://www.tldp.org/docs.html#howto>.
368
369 If you don't know what to do here, say N.
370
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371config X86_FEATURE_NAMES
372 bool "Processor feature human-readable names" if EMBEDDED
373 default y
374 ---help---
375 This option compiles in a table of x86 feature bits and corresponding
376 names. This is required to support /proc/cpuinfo and a few kernel
377 messages. You can disable this to save space, at the expense of
378 making those few kernel messages show numeric feature bits instead.
379
380 If in doubt, say Y.
381
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382config X86_FAST_FEATURE_TESTS
383 bool "Fast CPU feature tests" if EMBEDDED
384 default y
385 ---help---
386 Some fast-paths in the kernel depend on the capabilities of the CPU.
387 Say Y here for the kernel to patch in the appropriate code at runtime
388 based on the capabilities of the CPU. The infrastructure for patching
389 code at runtime takes up some additional space; space-constrained
390 embedded systems may wish to say N here to produce smaller, slightly
391 slower code.
392
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393config X86_X2APIC
394 bool "Support x2apic"
19e3d60d 395 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
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396 ---help---
397 This enables x2apic support on CPUs that have this feature.
398
399 This allows 32-bit apic IDs (so it can support very large systems),
400 and accesses the local apic via MSRs not via mmio.
401
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402 If you don't know what to do here, say N.
403
6695c85b 404config X86_MPPARSE
6e87f9b7 405 bool "Enable MPS table" if ACPI || SFI
7a527688 406 default y
5ab74722 407 depends on X86_LOCAL_APIC
8f9ca475 408 ---help---
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409 For old smp systems that do not have proper acpi support. Newer systems
410 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 411
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412config X86_BIGSMP
413 bool "Support for big SMP systems with more than 8 CPUs"
414 depends on X86_32 && SMP
8f9ca475 415 ---help---
26f7ef14 416 This option is needed for the systems that have more than 8 CPUs
506f1d07 417
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418config GOLDFISH
419 def_bool y
420 depends on X86_GOLDFISH
421
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422config INTEL_RDT_A
423 bool "Intel Resource Director Technology Allocation support"
424 default n
425 depends on X86 && CPU_SUP_INTEL
59fe5a77 426 select KERNFS
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427 help
428 Select to enable resource allocation which is a sub-feature of
429 Intel Resource Director Technology(RDT). More information about
430 RDT can be found in the Intel x86 Architecture Software
431 Developer Manual.
432
433 Say N if unsure.
434
8425091f 435if X86_32
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436config X86_EXTENDED_PLATFORM
437 bool "Support for extended (non-PC) x86 platforms"
438 default y
8f9ca475 439 ---help---
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440 If you disable this option then the kernel will only support
441 standard PC platforms. (which covers the vast majority of
442 systems out there.)
443
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444 If you enable this option then you'll be able to select support
445 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 446 Goldfish (Android emulator)
8425091f 447 AMD Elan
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448 RDC R-321x SoC
449 SGI 320/540 (Visual Workstation)
83125a3a 450 STA2X11-based (e.g. Northville)
3f4110a4 451 Moorestown MID devices
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452
453 If you have one of these systems, or if you want to build a
454 generic distribution kernel, say Y here - otherwise say N.
8425091f 455endif
06ac8346 456
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457if X86_64
458config X86_EXTENDED_PLATFORM
459 bool "Support for extended (non-PC) x86 platforms"
460 default y
461 ---help---
462 If you disable this option then the kernel will only support
463 standard PC platforms. (which covers the vast majority of
464 systems out there.)
465
466 If you enable this option then you'll be able to select support
467 for the following (non-PC) 64 bit x86 platforms:
44b111b5 468 Numascale NumaChip
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469 ScaleMP vSMP
470 SGI Ultraviolet
471
472 If you have one of these systems, or if you want to build a
473 generic distribution kernel, say Y here - otherwise say N.
474endif
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475# This is an alphabetically sorted list of 64 bit extended platforms
476# Please maintain the alphabetic order if and when there are additions
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SP
477config X86_NUMACHIP
478 bool "Numascale NumaChip"
479 depends on X86_64
480 depends on X86_EXTENDED_PLATFORM
481 depends on NUMA
482 depends on SMP
483 depends on X86_X2APIC
f9726bfd 484 depends on PCI_MMCONFIG
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SP
485 ---help---
486 Adds support for Numascale NumaChip large-SMP systems. Needed to
487 enable more than ~168 cores.
488 If you don't have one of these, you should say N here.
506f1d07 489
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490config X86_VSMP
491 bool "ScaleMP vSMP"
6276a074 492 select HYPERVISOR_GUEST
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493 select PARAVIRT
494 depends on X86_64 && PCI
495 depends on X86_EXTENDED_PLATFORM
ead91d4b 496 depends on SMP
8f9ca475 497 ---help---
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498 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
499 supposed to run on these EM64T-based machines. Only choose this option
500 if you have one of these machines.
5e3a77e9 501
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502config X86_UV
503 bool "SGI Ultraviolet"
504 depends on X86_64
c5c606d9 505 depends on X86_EXTENDED_PLATFORM
54c28d29 506 depends on NUMA
1ecb4ae5 507 depends on EFI
9d6c26e7 508 depends on X86_X2APIC
1222e564 509 depends on PCI
8f9ca475 510 ---help---
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511 This option is needed in order to support SGI Ultraviolet systems.
512 If you don't have one of these, you should say N here.
513
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514# Following is an alphabetically sorted list of 32 bit extended platforms
515# Please maintain the alphabetic order if and when there are additions
506f1d07 516
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517config X86_GOLDFISH
518 bool "Goldfish (Virtual Platform)"
cb7b8023 519 depends on X86_EXTENDED_PLATFORM
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520 ---help---
521 Enable support for the Goldfish virtual platform used primarily
522 for Android development. Unless you are building for the Android
523 Goldfish emulator say N here.
524
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TG
525config X86_INTEL_CE
526 bool "CE4100 TV platform"
527 depends on PCI
528 depends on PCI_GODIRECT
6084a6e2 529 depends on X86_IO_APIC
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TG
530 depends on X86_32
531 depends on X86_EXTENDED_PLATFORM
37bc9f50 532 select X86_REBOOTFIXUPS
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533 select OF
534 select OF_EARLY_FLATTREE
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TG
535 ---help---
536 Select for the Intel CE media processor (CE4100) SOC.
537 This option compiles in support for the CE4100 SOC for settop
538 boxes and media devices.
539
4cb9b00f 540config X86_INTEL_MID
43605ef1 541 bool "Intel MID platform support"
43605ef1 542 depends on X86_EXTENDED_PLATFORM
edc6bc78 543 depends on X86_PLATFORM_DEVICES
1ea7c673 544 depends on PCI
3fda5bb4 545 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 546 depends on X86_IO_APIC
7c9c3a1e 547 select SFI
4cb9b00f 548 select I2C
7c9c3a1e 549 select DW_APB_TIMER
1ea7c673 550 select APB_TIMER
1ea7c673 551 select INTEL_SCU_IPC
15a713df 552 select MFD_INTEL_MSIC
1ea7c673 553 ---help---
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DC
554 Select to build a kernel capable of supporting Intel MID (Mobile
555 Internet Device) platform systems which do not have the PCI legacy
556 interfaces. If you are building for a PC class system say N here.
1ea7c673 557
4cb9b00f
DC
558 Intel MID platforms are based on an Intel processor and chipset which
559 consume less power than most of the x86 derivatives.
43605ef1 560
8bbc2a13
BD
561config X86_INTEL_QUARK
562 bool "Intel Quark platform support"
563 depends on X86_32
564 depends on X86_EXTENDED_PLATFORM
565 depends on X86_PLATFORM_DEVICES
566 depends on X86_TSC
567 depends on PCI
568 depends on PCI_GOANY
569 depends on X86_IO_APIC
570 select IOSF_MBI
571 select INTEL_IMR
9ab6eb51 572 select COMMON_CLK
8bbc2a13
BD
573 ---help---
574 Select to include support for Quark X1000 SoC.
575 Say Y here if you have a Quark based system such as the Arduino
576 compatible Intel Galileo.
577
3d48aab1
MW
578config X86_INTEL_LPSS
579 bool "Intel Low Power Subsystem Support"
eebb3e8d 580 depends on X86 && ACPI
3d48aab1 581 select COMMON_CLK
0f531431 582 select PINCTRL
eebb3e8d 583 select IOSF_MBI
3d48aab1
MW
584 ---help---
585 Select to build support for Intel Low Power Subsystem such as
586 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
587 things like clock tree (common clock framework) and pincontrol
588 which are needed by the LPSS peripheral drivers.
3d48aab1 589
92082a88
KX
590config X86_AMD_PLATFORM_DEVICE
591 bool "AMD ACPI2Platform devices support"
592 depends on ACPI
593 select COMMON_CLK
594 select PINCTRL
595 ---help---
596 Select to interpret AMD specific ACPI device to platform device
597 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
598 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
599 implemented under PINCTRL subsystem.
600
ced3ce76
DB
601config IOSF_MBI
602 tristate "Intel SoC IOSF Sideband support for SoC platforms"
603 depends on PCI
604 ---help---
605 This option enables sideband register access support for Intel SoC
606 platforms. On these platforms the IOSF sideband is used in lieu of
607 MSR's for some register accesses, mostly but not limited to thermal
608 and power. Drivers may query the availability of this device to
609 determine if they need the sideband in order to work on these
610 platforms. The sideband is available on the following SoC products.
611 This list is not meant to be exclusive.
612 - BayTrail
613 - Braswell
614 - Quark
615
616 You should say Y if you are running a kernel on one of these SoC's.
617
ed2226bd
DB
618config IOSF_MBI_DEBUG
619 bool "Enable IOSF sideband access through debugfs"
620 depends on IOSF_MBI && DEBUG_FS
621 ---help---
622 Select this option to expose the IOSF sideband access registers (MCR,
623 MDR, MCRX) through debugfs to write and read register information from
624 different units on the SoC. This is most useful for obtaining device
625 state information for debug and analysis. As this is a general access
626 mechanism, users of this option would have specific knowledge of the
627 device they want to access.
628
629 If you don't require the option or are in doubt, say N.
630
c5c606d9
RT
631config X86_RDC321X
632 bool "RDC R-321x SoC"
506f1d07 633 depends on X86_32
c5c606d9
RT
634 depends on X86_EXTENDED_PLATFORM
635 select M486
636 select X86_REBOOTFIXUPS
637 ---help---
638 This option is needed for RDC R-321x system-on-chip, also known
639 as R-8610-(G).
640 If you don't have one of these chips, you should say N here.
641
e0c7ae37 642config X86_32_NON_STANDARD
9c398017
IM
643 bool "Support non-standard 32-bit SMP architectures"
644 depends on X86_32 && SMP
c5c606d9 645 depends on X86_EXTENDED_PLATFORM
8f9ca475 646 ---help---
b5660ba7
PA
647 This option compiles in the bigsmp and STA2X11 default
648 subarchitectures. It is intended for a generic binary
649 kernel. If you select them all, kernel will probe it one by
650 one and will fallback to default.
d49c4288 651
c5c606d9 652# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 653
d949f36f 654config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 655 def_bool y
d949f36f
LT
656 # MCE code calls memory_failure():
657 depends on X86_MCE
658 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
659 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
660 depends on X86_64 || !SPARSEMEM
661 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 662
83125a3a
AR
663config STA2X11
664 bool "STA2X11 Companion Chip Support"
665 depends on X86_32_NON_STANDARD && PCI
666 select X86_DEV_DMA_OPS
667 select X86_DMA_REMAP
668 select SWIOTLB
669 select MFD_STA2X11
0145071b 670 select GPIOLIB
83125a3a
AR
671 default n
672 ---help---
673 This adds support for boards based on the STA2X11 IO-Hub,
674 a.k.a. "ConneXt". The chip is used in place of the standard
675 PC chipset, so all "standard" peripherals are missing. If this
676 option is selected the kernel will still be able to boot on
677 standard PC machines.
678
82148d1d
S
679config X86_32_IRIS
680 tristate "Eurobraille/Iris poweroff module"
681 depends on X86_32
682 ---help---
683 The Iris machines from EuroBraille do not have APM or ACPI support
684 to shut themselves down properly. A special I/O sequence is
685 needed to do so, which is what this module does at
686 kernel shutdown.
687
688 This is only for Iris machines from EuroBraille.
689
690 If unused, say N.
691
ae1e9130 692config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
693 def_bool y
694 prompt "Single-depth WCHAN output"
a87d0914 695 depends on X86
8f9ca475 696 ---help---
506f1d07
SR
697 Calculate simpler /proc/<PID>/wchan values. If this option
698 is disabled then wchan values will recurse back to the
699 caller function. This provides more accurate wchan values,
700 at the expense of slightly more scheduling overhead.
701
702 If in doubt, say "Y".
703
6276a074
BP
704menuconfig HYPERVISOR_GUEST
705 bool "Linux guest support"
8f9ca475 706 ---help---
6276a074
BP
707 Say Y here to enable options for running Linux under various hyper-
708 visors. This option enables basic hypervisor detection and platform
709 setup.
506f1d07 710
6276a074
BP
711 If you say N, all options in this submenu will be skipped and
712 disabled, and Linux guest support won't be built in.
506f1d07 713
6276a074 714if HYPERVISOR_GUEST
506f1d07 715
e61bd94a
EPH
716config PARAVIRT
717 bool "Enable paravirtualization code"
8f9ca475 718 ---help---
e61bd94a
EPH
719 This changes the kernel so it can modify itself when it is run
720 under a hypervisor, potentially improving performance significantly
721 over full virtualization. However, when run without a hypervisor
722 the kernel is theoretically slower and slightly larger.
723
6276a074
BP
724config PARAVIRT_DEBUG
725 bool "paravirt-ops debugging"
726 depends on PARAVIRT && DEBUG_KERNEL
727 ---help---
728 Enable to debug paravirt_ops internals. Specifically, BUG if
729 a paravirt_op is missing when it is called.
730
b4ecc126
JF
731config PARAVIRT_SPINLOCKS
732 bool "Paravirtualization layer for spinlocks"
6ea30386 733 depends on PARAVIRT && SMP
b4ecc126
JF
734 ---help---
735 Paravirtualized spinlocks allow a pvops backend to replace the
736 spinlock implementation with something virtualization-friendly
737 (for example, block the virtual CPU rather than spinning).
738
4c4e4f61
R
739 It has a minimal impact on native kernels and gives a nice performance
740 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 741
4c4e4f61 742 If you are unsure how to answer this question, answer Y.
b4ecc126 743
45e898b7
WL
744config QUEUED_LOCK_STAT
745 bool "Paravirt queued spinlock statistics"
cfd8983f 746 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
747 ---help---
748 Enable the collection of statistical data on the slowpath
749 behavior of paravirtualized queued spinlocks and report
750 them on debugfs.
751
6276a074 752source "arch/x86/xen/Kconfig"
7af192c9 753
6276a074
BP
754config KVM_GUEST
755 bool "KVM Guest support (including kvmclock)"
756 depends on PARAVIRT
757 select PARAVIRT_CLOCK
758 default y
8f9ca475 759 ---help---
6276a074
BP
760 This option enables various optimizations for running under the KVM
761 hypervisor. It includes a paravirtualized clock, so that instead
762 of relying on a PIT (or probably other) emulation by the
763 underlying device model, the host provides the guest with
764 timing infrastructure such as time of day, and system time
506f1d07 765
1e20eb85
SV
766config KVM_DEBUG_FS
767 bool "Enable debug information for KVM Guests in debugfs"
768 depends on KVM_GUEST && DEBUG_FS
769 default n
770 ---help---
771 This option enables collection of various statistics for KVM guest.
772 Statistics are displayed in debugfs filesystem. Enabling this option
773 may incur significant overhead.
774
6276a074
BP
775source "arch/x86/lguest/Kconfig"
776
777config PARAVIRT_TIME_ACCOUNTING
778 bool "Paravirtual steal time accounting"
779 depends on PARAVIRT
780 default n
8f9ca475 781 ---help---
6276a074
BP
782 Select this option to enable fine granularity task steal time
783 accounting. Time spent executing other tasks in parallel with
784 the current vCPU is discounted from the vCPU power. To account for
785 that, there can be a small performance impact.
786
787 If in doubt, say N here.
788
789config PARAVIRT_CLOCK
790 bool
97349135 791
6276a074 792endif #HYPERVISOR_GUEST
97349135 793
08677214 794config NO_BOOTMEM
774ea0bc 795 def_bool y
08677214 796
506f1d07
SR
797source "arch/x86/Kconfig.cpu"
798
799config HPET_TIMER
3c2362e6 800 def_bool X86_64
506f1d07 801 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
802 ---help---
803 Use the IA-PC HPET (High Precision Event Timer) to manage
804 time in preference to the PIT and RTC, if a HPET is
805 present.
806 HPET is the next generation timer replacing legacy 8254s.
807 The HPET provides a stable time base on SMP
808 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
809 as it is off-chip. The interface used is documented
810 in the HPET spec, revision 1.
506f1d07 811
8f9ca475
IM
812 You can safely choose Y here. However, HPET will only be
813 activated if the platform and the BIOS support this feature.
814 Otherwise the 8254 will be used for timing services.
506f1d07 815
8f9ca475 816 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
817
818config HPET_EMULATE_RTC
3c2362e6 819 def_bool y
9d8af78b 820 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 821
bb24c471 822config APB_TIMER
933b9463
AC
823 def_bool y if X86_INTEL_MID
824 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 825 select DW_APB_TIMER
a0c3832a 826 depends on X86_INTEL_MID && SFI
bb24c471
JP
827 help
828 APB timer is the replacement for 8254, HPET on X86 MID platforms.
829 The APBT provides a stable time base on SMP
830 systems, unlike the TSC, but it is more expensive to access,
831 as it is off-chip. APB timers are always running regardless of CPU
832 C states, they are used as per CPU clockevent device when possible.
833
6a108a14 834# Mark as expert because too many people got it wrong.
506f1d07 835# The code disables itself when not needed.
7ae9392c
TP
836config DMI
837 default y
cf074402 838 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 839 bool "Enable DMI scanning" if EXPERT
8f9ca475 840 ---help---
7ae9392c
TP
841 Enabled scanning of DMI to identify machine quirks. Say Y
842 here unless you have verified that your setup is not
843 affected by entries in the DMI blacklist. Required by PNP
844 BIOS code.
845
506f1d07 846config GART_IOMMU
38901f1c 847 bool "Old AMD GART IOMMU support"
506f1d07 848 select SWIOTLB
23ac4ae8 849 depends on X86_64 && PCI && AMD_NB
8f9ca475 850 ---help---
ced3c42c
IM
851 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
852 GART based hardware IOMMUs.
853
854 The GART supports full DMA access for devices with 32-bit access
855 limitations, on systems with more than 3 GB. This is usually needed
856 for USB, sound, many IDE/SATA chipsets and some other devices.
857
858 Newer systems typically have a modern AMD IOMMU, supported via
859 the CONFIG_AMD_IOMMU=y config option.
860
861 In normal configurations this driver is only active when needed:
862 there's more than 3 GB of memory and the system contains a
863 32-bit limited device.
864
865 If unsure, say Y.
506f1d07
SR
866
867config CALGARY_IOMMU
868 bool "IBM Calgary IOMMU support"
869 select SWIOTLB
6ea30386 870 depends on X86_64 && PCI
8f9ca475 871 ---help---
506f1d07
SR
872 Support for hardware IOMMUs in IBM's xSeries x366 and x460
873 systems. Needed to run systems with more than 3GB of memory
874 properly with 32-bit PCI devices that do not support DAC
875 (Double Address Cycle). Calgary also supports bus level
876 isolation, where all DMAs pass through the IOMMU. This
877 prevents them from going anywhere except their intended
878 destination. This catches hard-to-find kernel bugs and
879 mis-behaving drivers and devices that do not use the DMA-API
880 properly to set up their DMA buffers. The IOMMU can be
881 turned off at boot time with the iommu=off parameter.
882 Normally the kernel will make the right choice by itself.
883 If unsure, say Y.
884
885config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
886 def_bool y
887 prompt "Should Calgary be enabled by default?"
506f1d07 888 depends on CALGARY_IOMMU
8f9ca475 889 ---help---
506f1d07
SR
890 Should Calgary be enabled by default? if you choose 'y', Calgary
891 will be used (if it exists). If you choose 'n', Calgary will not be
892 used even if it exists. If you choose 'n' and would like to use
893 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
894 If unsure, say Y.
895
896# need this always selected by IOMMU for the VIA workaround
897config SWIOTLB
a1afd01c 898 def_bool y if X86_64
8f9ca475 899 ---help---
506f1d07 900 Support for software bounce buffers used on x86-64 systems
4454d327
JM
901 which don't have a hardware IOMMU. Using this PCI devices
902 which can only access 32-bits of memory can be used on systems
903 with more than 3 GB of memory.
904 If unsure, say Y.
506f1d07 905
a8522509 906config IOMMU_HELPER
3120e25e
JB
907 def_bool y
908 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 909
1184dc2f 910config MAXSMP
ddb0c5a6 911 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 912 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 913 select CPUMASK_OFFSTACK
8f9ca475 914 ---help---
ddb0c5a6 915 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 916 If unsure, say N.
506f1d07
SR
917
918config NR_CPUS
36f5101a 919 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 920 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 921 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 922 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 923 default "1" if !SMP
b53b5eda 924 default "8192" if MAXSMP
b5660ba7 925 default "32" if SMP && X86_BIGSMP
c5c19941
KS
926 default "8" if SMP && X86_32
927 default "64" if SMP
8f9ca475 928 ---help---
506f1d07 929 This allows you to specify the maximum number of CPUs which this
bb61ccc7 930 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 931 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
932 minimum value which makes sense is 2.
933
934 This is purely to save memory - each supported CPU adds
935 approximately eight kilobytes to the kernel image.
936
937config SCHED_SMT
938 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 939 depends on SMP
8f9ca475 940 ---help---
506f1d07
SR
941 SMT scheduler support improves the CPU scheduler's decision making
942 when dealing with Intel Pentium 4 chips with HyperThreading at a
943 cost of slightly increased overhead in some places. If unsure say
944 N here.
945
946config SCHED_MC
3c2362e6
HH
947 def_bool y
948 prompt "Multi-core scheduler support"
c8e56d20 949 depends on SMP
8f9ca475 950 ---help---
506f1d07
SR
951 Multi-core scheduler support improves the CPU scheduler's decision
952 making when dealing with multi-core CPU chips at a cost of slightly
953 increased overhead in some places. If unsure say N here.
954
de966cf4
TC
955config SCHED_MC_PRIO
956 bool "CPU core priorities scheduler support"
0a21fc12
IM
957 depends on SCHED_MC && CPU_SUP_INTEL
958 select X86_INTEL_PSTATE
959 select CPU_FREQ
de966cf4 960 default y
5e76b2ab 961 ---help---
0a21fc12
IM
962 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
963 core ordering determined at manufacturing time, which allows
964 certain cores to reach higher turbo frequencies (when running
965 single threaded workloads) than others.
de966cf4 966
0a21fc12
IM
967 Enabling this kernel feature teaches the scheduler about
968 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
969 scheduler's CPU selection logic accordingly, so that higher
970 overall system performance can be achieved.
de966cf4 971
0a21fc12 972 This feature will have no effect on CPUs without this feature.
de966cf4 973
0a21fc12 974 If unsure say Y here.
5e76b2ab 975
506f1d07
SR
976source "kernel/Kconfig.preempt"
977
30b8b006
TG
978config UP_LATE_INIT
979 def_bool y
ba360f88 980 depends on !SMP && X86_LOCAL_APIC
30b8b006 981
506f1d07 982config X86_UP_APIC
50849eef
JB
983 bool "Local APIC support on uniprocessors" if !PCI_MSI
984 default PCI_MSI
38a1dfda 985 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 986 ---help---
506f1d07
SR
987 A local APIC (Advanced Programmable Interrupt Controller) is an
988 integrated interrupt controller in the CPU. If you have a single-CPU
989 system which has a processor with a local APIC, you can say Y here to
990 enable and use it. If you say Y here even though your machine doesn't
991 have a local APIC, then the kernel will still run with no slowdown at
992 all. The local APIC supports CPU-generated self-interrupts (timer,
993 performance counters), and the NMI watchdog which detects hard
994 lockups.
995
996config X86_UP_IOAPIC
997 bool "IO-APIC support on uniprocessors"
998 depends on X86_UP_APIC
8f9ca475 999 ---help---
506f1d07
SR
1000 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1001 SMP-capable replacement for PC-style interrupt controllers. Most
1002 SMP systems and many recent uniprocessor systems have one.
1003
1004 If you have a single-CPU system with an IO-APIC, you can say Y here
1005 to use it. If you say Y here even though your machine doesn't have
1006 an IO-APIC, then the kernel will still run with no slowdown at all.
1007
1008config X86_LOCAL_APIC
3c2362e6 1009 def_bool y
0dbc6078 1010 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1011 select IRQ_DOMAIN_HIERARCHY
52f518a3 1012 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1013
1014config X86_IO_APIC
b1da1e71
JB
1015 def_bool y
1016 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1017
41b9eb26
SA
1018config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1019 bool "Reroute for broken boot IRQs"
41b9eb26 1020 depends on X86_IO_APIC
8f9ca475 1021 ---help---
41b9eb26
SA
1022 This option enables a workaround that fixes a source of
1023 spurious interrupts. This is recommended when threaded
1024 interrupt handling is used on systems where the generation of
1025 superfluous "boot interrupts" cannot be disabled.
1026
1027 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1028 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1029 kernel does during interrupt handling). On chipsets where this
1030 boot IRQ generation cannot be disabled, this workaround keeps
1031 the original IRQ line masked so that only the equivalent "boot
1032 IRQ" is delivered to the CPUs. The workaround also tells the
1033 kernel to set up the IRQ handler on the boot IRQ line. In this
1034 way only one interrupt is delivered to the kernel. Otherwise
1035 the spurious second interrupt may cause the kernel to bring
1036 down (vital) interrupt lines.
1037
1038 Only affects "broken" chipsets. Interrupt sharing may be
1039 increased on these systems.
1040
506f1d07 1041config X86_MCE
bab9bc65 1042 bool "Machine Check / overheating reporting"
648ed940 1043 select GENERIC_ALLOCATOR
e57dbaf7 1044 default y
506f1d07 1045 ---help---
bab9bc65
AK
1046 Machine Check support allows the processor to notify the
1047 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1048 The action the kernel takes depends on the severity of the problem,
bab9bc65 1049 ranging from warning messages to halting the machine.
4efc0670 1050
5de97c9f
TL
1051config X86_MCELOG_LEGACY
1052 bool "Support for deprecated /dev/mcelog character device"
1053 depends on X86_MCE
1054 ---help---
1055 Enable support for /dev/mcelog which is needed by the old mcelog
1056 userspace logging daemon. Consider switching to the new generation
1057 rasdaemon solution.
1058
506f1d07 1059config X86_MCE_INTEL
3c2362e6
HH
1060 def_bool y
1061 prompt "Intel MCE features"
c1ebf835 1062 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1063 ---help---
506f1d07
SR
1064 Additional support for intel specific MCE features such as
1065 the thermal monitor.
1066
1067config X86_MCE_AMD
3c2362e6
HH
1068 def_bool y
1069 prompt "AMD MCE features"
f5382de9 1070 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1071 ---help---
506f1d07
SR
1072 Additional support for AMD specific MCE features such as
1073 the DRAM Error Threshold.
1074
4efc0670 1075config X86_ANCIENT_MCE
6fc108a0 1076 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1077 depends on X86_32 && X86_MCE
cd13adcc
HS
1078 ---help---
1079 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1080 systems. These typically need to be enabled explicitly on the command
cd13adcc 1081 line.
4efc0670 1082
b2762686
AK
1083config X86_MCE_THRESHOLD
1084 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1085 def_bool y
b2762686 1086
ea149b36 1087config X86_MCE_INJECT
bc8e80d5 1088 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1089 tristate "Machine check injector support"
1090 ---help---
1091 Provide support for injecting machine checks for testing purposes.
1092 If you don't know what a machine check is and you don't do kernel
1093 QA it is safe to say n.
1094
4efc0670
AK
1095config X86_THERMAL_VECTOR
1096 def_bool y
5bb38adc 1097 depends on X86_MCE_INTEL
4efc0670 1098
07dc900e 1099source "arch/x86/events/Kconfig"
e633c65a 1100
5aef51c3 1101config X86_LEGACY_VM86
1e642812 1102 bool "Legacy VM86 support"
5aef51c3 1103 default n
506f1d07 1104 depends on X86_32
8f9ca475 1105 ---help---
5aef51c3
AL
1106 This option allows user programs to put the CPU into V8086
1107 mode, which is an 80286-era approximation of 16-bit real mode.
1108
1109 Some very old versions of X and/or vbetool require this option
1110 for user mode setting. Similarly, DOSEMU will use it if
1111 available to accelerate real mode DOS programs. However, any
1112 recent version of DOSEMU, X, or vbetool should be fully
1113 functional even without kernel VM86 support, as they will all
1e642812
IM
1114 fall back to software emulation. Nevertheless, if you are using
1115 a 16-bit DOS program where 16-bit performance matters, vm86
1116 mode might be faster than emulation and you might want to
1117 enable this option.
5aef51c3 1118
1e642812
IM
1119 Note that any app that works on a 64-bit kernel is unlikely to
1120 need this option, as 64-bit kernels don't, and can't, support
1121 V8086 mode. This option is also unrelated to 16-bit protected
1122 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1123
1e642812
IM
1124 Enabling this option increases the complexity of the kernel
1125 and slows down exception handling a tiny bit.
5aef51c3 1126
1e642812 1127 If unsure, say N here.
5aef51c3
AL
1128
1129config VM86
1130 bool
1131 default X86_LEGACY_VM86
34273f41
PA
1132
1133config X86_16BIT
1134 bool "Enable support for 16-bit segments" if EXPERT
1135 default y
a5b9e5a2 1136 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1137 ---help---
1138 This option is required by programs like Wine to run 16-bit
1139 protected mode legacy code on x86 processors. Disabling
1140 this option saves about 300 bytes on i386, or around 6K text
1141 plus 16K runtime memory on x86-64,
1142
1143config X86_ESPFIX32
1144 def_bool y
1145 depends on X86_16BIT && X86_32
506f1d07 1146
197725de
PA
1147config X86_ESPFIX64
1148 def_bool y
34273f41 1149 depends on X86_16BIT && X86_64
506f1d07 1150
1ad83c85
AL
1151config X86_VSYSCALL_EMULATION
1152 bool "Enable vsyscall emulation" if EXPERT
1153 default y
1154 depends on X86_64
1155 ---help---
1156 This enables emulation of the legacy vsyscall page. Disabling
1157 it is roughly equivalent to booting with vsyscall=none, except
1158 that it will also disable the helpful warning if a program
1159 tries to use a vsyscall. With this option set to N, offending
1160 programs will just segfault, citing addresses of the form
1161 0xffffffffff600?00.
1162
1163 This option is required by many programs built before 2013, and
1164 care should be used even with newer programs if set to N.
1165
1166 Disabling this option saves about 7K of kernel size and
1167 possibly 4K of additional runtime pagetable memory.
1168
506f1d07
SR
1169config TOSHIBA
1170 tristate "Toshiba Laptop support"
1171 depends on X86_32
1172 ---help---
1173 This adds a driver to safely access the System Management Mode of
1174 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1175 not work on models with a Phoenix BIOS. The System Management Mode
1176 is used to set the BIOS and power saving options on Toshiba portables.
1177
1178 For information on utilities to make use of this driver see the
1179 Toshiba Linux utilities web site at:
1180 <http://www.buzzard.org.uk/toshiba/>.
1181
1182 Say Y if you intend to run this kernel on a Toshiba portable.
1183 Say N otherwise.
1184
1185config I8K
039ae585 1186 tristate "Dell i8k legacy laptop support"
949a9d70 1187 select HWMON
039ae585 1188 select SENSORS_DELL_SMM
506f1d07 1189 ---help---
039ae585
PR
1190 This option enables legacy /proc/i8k userspace interface in hwmon
1191 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1192 temperature and allows controlling fan speeds of Dell laptops via
1193 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1194 it reports also power and hotkey status. For fan speed control is
1195 needed userspace package i8kutils.
1196
1197 Say Y if you intend to run this kernel on old Dell laptops or want to
1198 use userspace package i8kutils.
506f1d07
SR
1199 Say N otherwise.
1200
1201config X86_REBOOTFIXUPS
9ba16087
JB
1202 bool "Enable X86 board specific fixups for reboot"
1203 depends on X86_32
506f1d07
SR
1204 ---help---
1205 This enables chipset and/or board specific fixups to be done
1206 in order to get reboot to work correctly. This is only needed on
1207 some combinations of hardware and BIOS. The symptom, for which
1208 this config is intended, is when reboot ends with a stalled/hung
1209 system.
1210
1211 Currently, the only fixup is for the Geode machines using
5e3a77e9 1212 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1213
1214 Say Y if you want to enable the fixup. Currently, it's safe to
1215 enable this option even if you don't need it.
1216 Say N otherwise.
1217
1218config MICROCODE
9a2bc335
BP
1219 bool "CPU microcode loading support"
1220 default y
80030e3d 1221 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1222 select FW_LOADER
1223 ---help---
1224 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1225 Intel and AMD processors. The Intel support is for the IA32 family,
1226 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1227 AMD support is for families 0x10 and later. You will obviously need
1228 the actual microcode binary data itself which is not shipped with
1229 the Linux kernel.
1230
1231 The preferred method to load microcode from a detached initrd is described
1232 in Documentation/x86/early-microcode.txt. For that you need to enable
1233 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1234 initrd for microcode blobs.
1235
1236 In addition, you can build-in the microcode into the kernel. For that you
1237 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1238 to the CONFIG_EXTRA_FIRMWARE config option.
506f1d07 1239
8d86f390 1240config MICROCODE_INTEL
e43f6e67 1241 bool "Intel microcode loading support"
8f9ca475
IM
1242 depends on MICROCODE
1243 default MICROCODE
1244 select FW_LOADER
1245 ---help---
1246 This options enables microcode patch loading support for Intel
1247 processors.
1248
b8989db9
A
1249 For the current Intel microcode data package go to
1250 <https://downloadcenter.intel.com> and search for
1251 'Linux Processor Microcode Data File'.
8d86f390 1252
80cc9f10 1253config MICROCODE_AMD
e43f6e67 1254 bool "AMD microcode loading support"
8f9ca475
IM
1255 depends on MICROCODE
1256 select FW_LOADER
1257 ---help---
1258 If you select this option, microcode patch loading support for AMD
1259 processors will be enabled.
80cc9f10 1260
8f9ca475 1261config MICROCODE_OLD_INTERFACE
3c2362e6 1262 def_bool y
506f1d07 1263 depends on MICROCODE
506f1d07
SR
1264
1265config X86_MSR
1266 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1267 ---help---
506f1d07
SR
1268 This device gives privileged processes access to the x86
1269 Model-Specific Registers (MSRs). It is a character device with
1270 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1271 MSR accesses are directed to a specific CPU on multi-processor
1272 systems.
1273
1274config X86_CPUID
1275 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1276 ---help---
506f1d07
SR
1277 This device gives processes access to the x86 CPUID instruction to
1278 be executed on a specific processor. It is a character device
1279 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1280 /dev/cpu/31/cpuid.
1281
1282choice
1283 prompt "High Memory Support"
6fc108a0 1284 default HIGHMEM4G
506f1d07
SR
1285 depends on X86_32
1286
1287config NOHIGHMEM
1288 bool "off"
506f1d07
SR
1289 ---help---
1290 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1291 However, the address space of 32-bit x86 processors is only 4
1292 Gigabytes large. That means that, if you have a large amount of
1293 physical memory, not all of it can be "permanently mapped" by the
1294 kernel. The physical memory that's not permanently mapped is called
1295 "high memory".
1296
1297 If you are compiling a kernel which will never run on a machine with
1298 more than 1 Gigabyte total physical RAM, answer "off" here (default
1299 choice and suitable for most users). This will result in a "3GB/1GB"
1300 split: 3GB are mapped so that each process sees a 3GB virtual memory
1301 space and the remaining part of the 4GB virtual memory space is used
1302 by the kernel to permanently map as much physical memory as
1303 possible.
1304
1305 If the machine has between 1 and 4 Gigabytes physical RAM, then
1306 answer "4GB" here.
1307
1308 If more than 4 Gigabytes is used then answer "64GB" here. This
1309 selection turns Intel PAE (Physical Address Extension) mode on.
1310 PAE implements 3-level paging on IA32 processors. PAE is fully
1311 supported by Linux, PAE mode is implemented on all recent Intel
1312 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1313 then the kernel will not boot on CPUs that don't support PAE!
1314
1315 The actual amount of total physical memory will either be
1316 auto detected or can be forced by using a kernel command line option
1317 such as "mem=256M". (Try "man bootparam" or see the documentation of
1318 your boot loader (lilo or loadlin) about how to pass options to the
1319 kernel at boot time.)
1320
1321 If unsure, say "off".
1322
1323config HIGHMEM4G
1324 bool "4GB"
8f9ca475 1325 ---help---
506f1d07
SR
1326 Select this if you have a 32-bit processor and between 1 and 4
1327 gigabytes of physical RAM.
1328
1329config HIGHMEM64G
1330 bool "64GB"
eb068e78 1331 depends on !M486
506f1d07 1332 select X86_PAE
8f9ca475 1333 ---help---
506f1d07
SR
1334 Select this if you have a 32-bit processor and more than 4
1335 gigabytes of physical RAM.
1336
1337endchoice
1338
1339choice
6a108a14 1340 prompt "Memory split" if EXPERT
506f1d07
SR
1341 default VMSPLIT_3G
1342 depends on X86_32
8f9ca475 1343 ---help---
506f1d07
SR
1344 Select the desired split between kernel and user memory.
1345
1346 If the address range available to the kernel is less than the
1347 physical memory installed, the remaining memory will be available
1348 as "high memory". Accessing high memory is a little more costly
1349 than low memory, as it needs to be mapped into the kernel first.
1350 Note that increasing the kernel address space limits the range
1351 available to user programs, making the address space there
1352 tighter. Selecting anything other than the default 3G/1G split
1353 will also likely make your kernel incompatible with binary-only
1354 kernel modules.
1355
1356 If you are not absolutely sure what you are doing, leave this
1357 option alone!
1358
1359 config VMSPLIT_3G
1360 bool "3G/1G user/kernel split"
1361 config VMSPLIT_3G_OPT
1362 depends on !X86_PAE
1363 bool "3G/1G user/kernel split (for full 1G low memory)"
1364 config VMSPLIT_2G
1365 bool "2G/2G user/kernel split"
1366 config VMSPLIT_2G_OPT
1367 depends on !X86_PAE
1368 bool "2G/2G user/kernel split (for full 2G low memory)"
1369 config VMSPLIT_1G
1370 bool "1G/3G user/kernel split"
1371endchoice
1372
1373config PAGE_OFFSET
1374 hex
1375 default 0xB0000000 if VMSPLIT_3G_OPT
1376 default 0x80000000 if VMSPLIT_2G
1377 default 0x78000000 if VMSPLIT_2G_OPT
1378 default 0x40000000 if VMSPLIT_1G
1379 default 0xC0000000
1380 depends on X86_32
1381
1382config HIGHMEM
3c2362e6 1383 def_bool y
506f1d07 1384 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1385
1386config X86_PAE
9ba16087 1387 bool "PAE (Physical Address Extension) Support"
506f1d07 1388 depends on X86_32 && !HIGHMEM4G
9d99c712 1389 select SWIOTLB
8f9ca475 1390 ---help---
506f1d07
SR
1391 PAE is required for NX support, and furthermore enables
1392 larger swapspace support for non-overcommit purposes. It
1393 has the cost of more pagetable lookup overhead, and also
1394 consumes more pagetable space per process.
1395
600715dc 1396config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1397 def_bool y
1398 depends on X86_64 || X86_PAE
600715dc 1399
66f2b061 1400config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1401 def_bool y
1402 depends on X86_64 || HIGHMEM64G
66f2b061 1403
10971ab2 1404config X86_DIRECT_GBPAGES
e5008abe
LR
1405 def_bool y
1406 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1407 ---help---
10971ab2
IM
1408 Certain kernel features effectively disable kernel
1409 linear 1 GB mappings (even if the CPU otherwise
1410 supports them), so don't confuse the user by printing
1411 that we have them enabled.
9e899816 1412
506f1d07
SR
1413# Common NUMA Features
1414config NUMA
fd51b2d7 1415 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1416 depends on SMP
b5660ba7
PA
1417 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1418 default y if X86_BIGSMP
8f9ca475 1419 ---help---
506f1d07 1420 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1421
506f1d07
SR
1422 The kernel will try to allocate memory used by a CPU on the
1423 local memory controller of the CPU and add some more
1424 NUMA awareness to the kernel.
1425
c280ea5e 1426 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1427 (or later), AMD Opteron, or EM64T NUMA.
1428
b5660ba7 1429 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1430 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1431
1432 Otherwise, you should say N.
506f1d07 1433
eec1d4fa 1434config AMD_NUMA
3c2362e6
HH
1435 def_bool y
1436 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1437 depends on X86_64 && NUMA && PCI
8f9ca475 1438 ---help---
eec1d4fa
HR
1439 Enable AMD NUMA node topology detection. You should say Y here if
1440 you have a multi processor AMD system. This uses an old method to
1441 read the NUMA configuration directly from the builtin Northbridge
1442 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1443 which also takes priority if both are compiled in.
506f1d07
SR
1444
1445config X86_64_ACPI_NUMA
3c2362e6
HH
1446 def_bool y
1447 prompt "ACPI NUMA detection"
506f1d07
SR
1448 depends on X86_64 && NUMA && ACPI && PCI
1449 select ACPI_NUMA
8f9ca475 1450 ---help---
506f1d07
SR
1451 Enable ACPI SRAT based node topology detection.
1452
6ec6e0d9
SS
1453# Some NUMA nodes have memory ranges that span
1454# other nodes. Even though a pfn is valid and
1455# between a node's start and end pfns, it may not
1456# reside on that node. See memmap_init_zone()
1457# for details.
1458config NODES_SPAN_OTHER_NODES
1459 def_bool y
1460 depends on X86_64_ACPI_NUMA
1461
506f1d07
SR
1462config NUMA_EMU
1463 bool "NUMA emulation"
1b7e03ef 1464 depends on NUMA
8f9ca475 1465 ---help---
506f1d07
SR
1466 Enable NUMA emulation. A flat machine will be split
1467 into virtual nodes when booted with "numa=fake=N", where N is the
1468 number of nodes. This is only useful for debugging.
1469
1470config NODES_SHIFT
d25e26b6 1471 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1472 range 1 10
1473 default "10" if MAXSMP
506f1d07 1474 default "6" if X86_64
506f1d07
SR
1475 default "3"
1476 depends on NEED_MULTIPLE_NODES
8f9ca475 1477 ---help---
1184dc2f 1478 Specify the maximum number of NUMA Nodes available on the target
692105b8 1479 system. Increases memory reserved to accommodate various tables.
506f1d07 1480
506f1d07 1481config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1482 def_bool y
506f1d07 1483 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1484
1485config NEED_NODE_MEMMAP_SIZE
3c2362e6 1486 def_bool y
506f1d07 1487 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1488
506f1d07
SR
1489config ARCH_FLATMEM_ENABLE
1490 def_bool y
3b16651f 1491 depends on X86_32 && !NUMA
506f1d07
SR
1492
1493config ARCH_DISCONTIGMEM_ENABLE
1494 def_bool y
b263295d 1495 depends on NUMA && X86_32
506f1d07
SR
1496
1497config ARCH_DISCONTIGMEM_DEFAULT
1498 def_bool y
b263295d
CL
1499 depends on NUMA && X86_32
1500
506f1d07
SR
1501config ARCH_SPARSEMEM_ENABLE
1502 def_bool y
6ea30386 1503 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1504 select SPARSEMEM_STATIC if X86_32
1505 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1506
3b16651f
TH
1507config ARCH_SPARSEMEM_DEFAULT
1508 def_bool y
1509 depends on X86_64
1510
506f1d07
SR
1511config ARCH_SELECT_MEMORY_MODEL
1512 def_bool y
b263295d 1513 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1514
1515config ARCH_MEMORY_PROBE
a0842b70 1516 bool "Enable sysfs memory/probe interface"
3120e25e 1517 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1518 help
1519 This option enables a sysfs memory/probe interface for testing.
1520 See Documentation/memory-hotplug.txt for more information.
1521 If you are unsure how to answer this question, answer N.
506f1d07 1522
3b16651f
TH
1523config ARCH_PROC_KCORE_TEXT
1524 def_bool y
1525 depends on X86_64 && PROC_KCORE
1526
a29815a3
AK
1527config ILLEGAL_POINTER_VALUE
1528 hex
1529 default 0 if X86_32
1530 default 0xdead000000000000 if X86_64
1531
506f1d07
SR
1532source "mm/Kconfig"
1533
7a67832c
DW
1534config X86_PMEM_LEGACY_DEVICE
1535 bool
1536
ec776ef6 1537config X86_PMEM_LEGACY
7a67832c 1538 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1539 depends on PHYS_ADDR_T_64BIT
1540 depends on BLK_DEV
7a67832c 1541 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1542 select LIBNVDIMM
ec776ef6
CH
1543 help
1544 Treat memory marked using the non-standard e820 type of 12 as used
1545 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1546 The kernel will offer these regions to the 'pmem' driver so
1547 they can be used for persistent storage.
1548
1549 Say Y if unsure.
1550
506f1d07
SR
1551config HIGHPTE
1552 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1553 depends on HIGHMEM
8f9ca475 1554 ---help---
506f1d07
SR
1555 The VM uses one page table entry for each page of physical memory.
1556 For systems with a lot of RAM, this can be wasteful of precious
1557 low memory. Setting this option will put user-space page table
1558 entries in high memory.
1559
9f077871 1560config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1561 bool "Check for low memory corruption"
1562 ---help---
1563 Periodically check for memory corruption in low memory, which
1564 is suspected to be caused by BIOS. Even when enabled in the
1565 configuration, it is disabled at runtime. Enable it by
1566 setting "memory_corruption_check=1" on the kernel command
1567 line. By default it scans the low 64k of memory every 60
1568 seconds; see the memory_corruption_check_size and
1569 memory_corruption_check_period parameters in
8c27ceff 1570 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1571
1572 When enabled with the default parameters, this option has
1573 almost no overhead, as it reserves a relatively small amount
1574 of memory and scans it infrequently. It both detects corruption
1575 and prevents it from affecting the running system.
1576
1577 It is, however, intended as a diagnostic tool; if repeatable
1578 BIOS-originated corruption always affects the same memory,
1579 you can use memmap= to prevent the kernel from using that
1580 memory.
9f077871 1581
c885df50 1582config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1583 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1584 depends on X86_CHECK_BIOS_CORRUPTION
1585 default y
8f9ca475
IM
1586 ---help---
1587 Set whether the default state of memory_corruption_check is
1588 on or off.
c885df50 1589
9ea77bdb 1590config X86_RESERVE_LOW
d0cd7425
PA
1591 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1592 default 64
1593 range 4 640
8f9ca475 1594 ---help---
d0cd7425
PA
1595 Specify the amount of low memory to reserve for the BIOS.
1596
1597 The first page contains BIOS data structures that the kernel
1598 must not use, so that page must always be reserved.
1599
1600 By default we reserve the first 64K of physical RAM, as a
1601 number of BIOSes are known to corrupt that memory range
1602 during events such as suspend/resume or monitor cable
1603 insertion, so it must not be used by the kernel.
fc381519 1604
d0cd7425
PA
1605 You can set this to 4 if you are absolutely sure that you
1606 trust the BIOS to get all its memory reservations and usages
1607 right. If you know your BIOS have problems beyond the
1608 default 64K area, you can set this to 640 to avoid using the
1609 entire low memory range.
fc381519 1610
d0cd7425
PA
1611 If you have doubts about the BIOS (e.g. suspend/resume does
1612 not work or there's kernel crashes after certain hardware
1613 hotplug events) then you might want to enable
1614 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1615 typical corruption patterns.
fc381519 1616
d0cd7425 1617 Leave this to the default value of 64 if you are unsure.
fc381519 1618
506f1d07
SR
1619config MATH_EMULATION
1620 bool
a5b9e5a2 1621 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1622 prompt "Math emulation" if X86_32
1623 ---help---
1624 Linux can emulate a math coprocessor (used for floating point
1625 operations) if you don't have one. 486DX and Pentium processors have
1626 a math coprocessor built in, 486SX and 386 do not, unless you added
1627 a 487DX or 387, respectively. (The messages during boot time can
1628 give you some hints here ["man dmesg"].) Everyone needs either a
1629 coprocessor or this emulation.
1630
1631 If you don't have a math coprocessor, you need to say Y here; if you
1632 say Y here even though you have a coprocessor, the coprocessor will
1633 be used nevertheless. (This behavior can be changed with the kernel
1634 command line option "no387", which comes handy if your coprocessor
1635 is broken. Try "man bootparam" or see the documentation of your boot
1636 loader (lilo or loadlin) about how to pass options to the kernel at
1637 boot time.) This means that it is a good idea to say Y here if you
1638 intend to use this kernel on different machines.
1639
1640 More information about the internals of the Linux math coprocessor
1641 emulation can be found in <file:arch/x86/math-emu/README>.
1642
1643 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1644 kernel, it won't hurt.
1645
1646config MTRR
6fc108a0 1647 def_bool y
6a108a14 1648 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1649 ---help---
1650 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1651 the Memory Type Range Registers (MTRRs) may be used to control
1652 processor access to memory ranges. This is most useful if you have
1653 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1654 allows bus write transfers to be combined into a larger transfer
1655 before bursting over the PCI/AGP bus. This can increase performance
1656 of image write operations 2.5 times or more. Saying Y here creates a
1657 /proc/mtrr file which may be used to manipulate your processor's
1658 MTRRs. Typically the X server should use this.
1659
1660 This code has a reasonably generic interface so that similar
1661 control registers on other processors can be easily supported
1662 as well:
1663
1664 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1665 Registers (ARRs) which provide a similar functionality to MTRRs. For
1666 these, the ARRs are used to emulate the MTRRs.
1667 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1668 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1669 write-combining. All of these processors are supported by this code
1670 and it makes sense to say Y here if you have one of them.
1671
1672 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1673 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1674 can lead to all sorts of problems, so it's good to say Y here.
1675
1676 You can safely say Y even if your machine doesn't have MTRRs, you'll
1677 just add about 9 KB to your kernel.
1678
7225e751 1679 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1680
95ffa243 1681config MTRR_SANITIZER
2ffb3501 1682 def_bool y
95ffa243
YL
1683 prompt "MTRR cleanup support"
1684 depends on MTRR
8f9ca475 1685 ---help---
aba3728c
TG
1686 Convert MTRR layout from continuous to discrete, so X drivers can
1687 add writeback entries.
95ffa243 1688
aba3728c 1689 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1690 The largest mtrr entry size for a continuous block can be set with
aba3728c 1691 mtrr_chunk_size.
95ffa243 1692
2ffb3501 1693 If unsure, say Y.
95ffa243
YL
1694
1695config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1696 int "MTRR cleanup enable value (0-1)"
1697 range 0 1
1698 default "0"
95ffa243 1699 depends on MTRR_SANITIZER
8f9ca475 1700 ---help---
f5098d62 1701 Enable mtrr cleanup default value
95ffa243 1702
12031a62
YL
1703config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1704 int "MTRR cleanup spare reg num (0-7)"
1705 range 0 7
1706 default "1"
1707 depends on MTRR_SANITIZER
8f9ca475 1708 ---help---
12031a62 1709 mtrr cleanup spare entries default, it can be changed via
aba3728c 1710 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1711
2e5d9c85 1712config X86_PAT
6fc108a0 1713 def_bool y
6a108a14 1714 prompt "x86 PAT support" if EXPERT
2a8a2719 1715 depends on MTRR
8f9ca475 1716 ---help---
2e5d9c85 1717 Use PAT attributes to setup page level cache control.
042b78e4 1718
2e5d9c85 1719 PATs are the modern equivalents of MTRRs and are much more
1720 flexible than MTRRs.
1721
1722 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1723 spontaneous reboots) or a non-working video driver.
2e5d9c85 1724
1725 If unsure, say Y.
1726
46cf98cd
VP
1727config ARCH_USES_PG_UNCACHED
1728 def_bool y
1729 depends on X86_PAT
1730
628c6246
PA
1731config ARCH_RANDOM
1732 def_bool y
1733 prompt "x86 architectural random number generator" if EXPERT
1734 ---help---
1735 Enable the x86 architectural RDRAND instruction
1736 (Intel Bull Mountain technology) to generate random numbers.
1737 If supported, this is a high bandwidth, cryptographically
1738 secure hardware random number generator.
1739
51ae4a2d
PA
1740config X86_SMAP
1741 def_bool y
1742 prompt "Supervisor Mode Access Prevention" if EXPERT
1743 ---help---
1744 Supervisor Mode Access Prevention (SMAP) is a security
1745 feature in newer Intel processors. There is a small
1746 performance cost if this enabled and turned on; there is
1747 also a small increase in the kernel size if this is enabled.
1748
1749 If unsure, say Y.
1750
72e9b5fe
DH
1751config X86_INTEL_MPX
1752 prompt "Intel MPX (Memory Protection Extensions)"
1753 def_bool n
1754 depends on CPU_SUP_INTEL
1755 ---help---
1756 MPX provides hardware features that can be used in
1757 conjunction with compiler-instrumented code to check
1758 memory references. It is designed to detect buffer
1759 overflow or underflow bugs.
1760
1761 This option enables running applications which are
1762 instrumented or otherwise use MPX. It does not use MPX
1763 itself inside the kernel or to protect the kernel
1764 against bad memory references.
1765
1766 Enabling this option will make the kernel larger:
1767 ~8k of kernel text and 36 bytes of data on a 64-bit
1768 defconfig. It adds a long to the 'mm_struct' which
1769 will increase the kernel memory overhead of each
1770 process and adds some branches to paths used during
1771 exec() and munmap().
1772
1773 For details, see Documentation/x86/intel_mpx.txt
1774
1775 If unsure, say N.
1776
35e97790 1777config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1778 prompt "Intel Memory Protection Keys"
35e97790 1779 def_bool y
284244a9 1780 # Note: only available in 64-bit mode
35e97790 1781 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1782 select ARCH_USES_HIGH_VMA_FLAGS
1783 select ARCH_HAS_PKEYS
284244a9
DH
1784 ---help---
1785 Memory Protection Keys provides a mechanism for enforcing
1786 page-based protections, but without requiring modification of the
1787 page tables when an application changes protection domains.
1788
1789 For details, see Documentation/x86/protection-keys.txt
1790
1791 If unsure, say y.
35e97790 1792
506f1d07 1793config EFI
9ba16087 1794 bool "EFI runtime service support"
5b83683f 1795 depends on ACPI
f6ce5002 1796 select UCS2_STRING
022ee6c5 1797 select EFI_RUNTIME_WRAPPERS
506f1d07 1798 ---help---
8f9ca475
IM
1799 This enables the kernel to use EFI runtime services that are
1800 available (such as the EFI variable services).
506f1d07 1801
8f9ca475
IM
1802 This option is only useful on systems that have EFI firmware.
1803 In addition, you should use the latest ELILO loader available
1804 at <http://elilo.sourceforge.net> in order to take advantage
1805 of EFI runtime services. However, even with this option, the
1806 resultant kernel should continue to boot on existing non-EFI
1807 platforms.
506f1d07 1808
291f3632
MF
1809config EFI_STUB
1810 bool "EFI stub support"
b16d8c23 1811 depends on EFI && !X86_USE_3DNOW
7b2a583a 1812 select RELOCATABLE
291f3632
MF
1813 ---help---
1814 This kernel feature allows a bzImage to be loaded directly
1815 by EFI firmware without the use of a bootloader.
1816
4172fe2f 1817 See Documentation/efi-stub.txt for more information.
0c759662 1818
7d453eee
MF
1819config EFI_MIXED
1820 bool "EFI mixed-mode support"
1821 depends on EFI_STUB && X86_64
1822 ---help---
1823 Enabling this feature allows a 64-bit kernel to be booted
1824 on a 32-bit firmware, provided that your CPU supports 64-bit
1825 mode.
1826
1827 Note that it is not possible to boot a mixed-mode enabled
1828 kernel via the EFI boot stub - a bootloader that supports
1829 the EFI handover protocol must be used.
1830
1831 If unsure, say N.
1832
506f1d07 1833config SECCOMP
3c2362e6
HH
1834 def_bool y
1835 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1836 ---help---
506f1d07
SR
1837 This kernel feature is useful for number crunching applications
1838 that may need to compute untrusted bytecode during their
1839 execution. By using pipes or other transports made available to
1840 the process as file descriptors supporting the read/write
1841 syscalls, it's possible to isolate those applications in
1842 their own address space using seccomp. Once seccomp is
9c0bbee8 1843 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1844 and the task is only allowed to execute a few safe syscalls
1845 defined by each seccomp mode.
1846
1847 If unsure, say Y. Only embedded should say N here.
1848
506f1d07
SR
1849source kernel/Kconfig.hz
1850
1851config KEXEC
1852 bool "kexec system call"
2965faa5 1853 select KEXEC_CORE
8f9ca475 1854 ---help---
506f1d07
SR
1855 kexec is a system call that implements the ability to shutdown your
1856 current kernel, and to start another kernel. It is like a reboot
1857 but it is independent of the system firmware. And like a reboot
1858 you can start any kernel with it, not just Linux.
1859
1860 The name comes from the similarity to the exec system call.
1861
1862 It is an ongoing process to be certain the hardware in a machine
1863 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1864 initially work for you. As of this writing the exact hardware
1865 interface is strongly in flux, so no good recommendation can be
1866 made.
506f1d07 1867
74ca317c
VG
1868config KEXEC_FILE
1869 bool "kexec file based system call"
2965faa5 1870 select KEXEC_CORE
74ca317c 1871 select BUILD_BIN2C
74ca317c
VG
1872 depends on X86_64
1873 depends on CRYPTO=y
1874 depends on CRYPTO_SHA256=y
1875 ---help---
1876 This is new version of kexec system call. This system call is
1877 file based and takes file descriptors as system call argument
1878 for kernel and initramfs as opposed to list of segments as
1879 accepted by previous system call.
1880
8e7d8381
VG
1881config KEXEC_VERIFY_SIG
1882 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1883 depends on KEXEC_FILE
8e7d8381
VG
1884 ---help---
1885 This option makes kernel signature verification mandatory for
d8eb8940
BP
1886 the kexec_file_load() syscall.
1887
1888 In addition to that option, you need to enable signature
1889 verification for the corresponding kernel image type being
1890 loaded in order for this to work.
8e7d8381
VG
1891
1892config KEXEC_BZIMAGE_VERIFY_SIG
1893 bool "Enable bzImage signature verification support"
1894 depends on KEXEC_VERIFY_SIG
1895 depends on SIGNED_PE_FILE_VERIFICATION
1896 select SYSTEM_TRUSTED_KEYRING
1897 ---help---
1898 Enable bzImage signature verification support.
1899
506f1d07 1900config CRASH_DUMP
04b69447 1901 bool "kernel crash dumps"
506f1d07 1902 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1903 ---help---
506f1d07
SR
1904 Generate crash dump after being started by kexec.
1905 This should be normally only set in special crash dump kernels
1906 which are loaded in the main kernel with kexec-tools into
1907 a specially reserved region and then later executed after
1908 a crash by kdump/kexec. The crash dump kernel must be compiled
1909 to a memory address not used by the main kernel or BIOS using
1910 PHYSICAL_START, or it must be built as a relocatable image
1911 (CONFIG_RELOCATABLE=y).
1912 For more details see Documentation/kdump/kdump.txt
1913
3ab83521 1914config KEXEC_JUMP
6ea30386 1915 bool "kexec jump"
fee7b0d8 1916 depends on KEXEC && HIBERNATION
8f9ca475 1917 ---help---
89081d17
HY
1918 Jump between original kernel and kexeced kernel and invoke
1919 code in physical address mode via KEXEC
3ab83521 1920
506f1d07 1921config PHYSICAL_START
6a108a14 1922 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1923 default "0x1000000"
8f9ca475 1924 ---help---
506f1d07
SR
1925 This gives the physical address where the kernel is loaded.
1926
1927 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1928 bzImage will decompress itself to above physical address and
1929 run from there. Otherwise, bzImage will run from the address where
1930 it has been loaded by the boot loader and will ignore above physical
1931 address.
1932
1933 In normal kdump cases one does not have to set/change this option
1934 as now bzImage can be compiled as a completely relocatable image
1935 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1936 address. This option is mainly useful for the folks who don't want
1937 to use a bzImage for capturing the crash dump and want to use a
1938 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1939 to be specifically compiled to run from a specific memory area
1940 (normally a reserved region) and this option comes handy.
1941
ceefccc9
PA
1942 So if you are using bzImage for capturing the crash dump,
1943 leave the value here unchanged to 0x1000000 and set
1944 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1945 for capturing the crash dump change this value to start of
1946 the reserved region. In other words, it can be set based on
1947 the "X" value as specified in the "crashkernel=YM@XM"
1948 command line boot parameter passed to the panic-ed
1949 kernel. Please take a look at Documentation/kdump/kdump.txt
1950 for more details about crash dumps.
506f1d07
SR
1951
1952 Usage of bzImage for capturing the crash dump is recommended as
1953 one does not have to build two kernels. Same kernel can be used
1954 as production kernel and capture kernel. Above option should have
1955 gone away after relocatable bzImage support is introduced. But it
1956 is present because there are users out there who continue to use
1957 vmlinux for dump capture. This option should go away down the
1958 line.
1959
1960 Don't change this unless you know what you are doing.
1961
1962config RELOCATABLE
26717808
PA
1963 bool "Build a relocatable kernel"
1964 default y
8f9ca475 1965 ---help---
506f1d07
SR
1966 This builds a kernel image that retains relocation information
1967 so it can be loaded someplace besides the default 1MB.
1968 The relocations tend to make the kernel binary about 10% larger,
1969 but are discarded at runtime.
1970
1971 One use is for the kexec on panic case where the recovery kernel
1972 must live at a different physical address than the primary
1973 kernel.
1974
1975 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1976 it has been loaded at and the compile time physical address
8ab3820f 1977 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1978
8ab3820f 1979config RANDOMIZE_BASE
e8581e3d 1980 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 1981 depends on RELOCATABLE
6807c846 1982 default y
8ab3820f 1983 ---help---
e8581e3d
BH
1984 In support of Kernel Address Space Layout Randomization (KASLR),
1985 this randomizes the physical address at which the kernel image
1986 is decompressed and the virtual address where the kernel
1987 image is mapped, as a security feature that deters exploit
1988 attempts relying on knowledge of the location of kernel
1989 code internals.
1990
ed9f007e
KC
1991 On 64-bit, the kernel physical and virtual addresses are
1992 randomized separately. The physical address will be anywhere
1993 between 16MB and the top of physical memory (up to 64TB). The
1994 virtual address will be randomized from 16MB up to 1GB (9 bits
1995 of entropy). Note that this also reduces the memory space
1996 available to kernel modules from 1.5GB to 1GB.
1997
1998 On 32-bit, the kernel physical and virtual addresses are
1999 randomized together. They will be randomized from 16MB up to
2000 512MB (8 bits of entropy).
e8581e3d
BH
2001
2002 Entropy is generated using the RDRAND instruction if it is
2003 supported. If RDTSC is supported, its value is mixed into
2004 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2005 supported, then entropy is read from the i8254 timer. The
2006 usable entropy is limited by the kernel being built using
2007 2GB addressing, and that PHYSICAL_ALIGN must be at a
2008 minimum of 2MB. As a result, only 10 bits of entropy are
2009 theoretically possible, but the implementations are further
2010 limited due to memory layouts.
e8581e3d 2011
6807c846 2012 If unsure, say Y.
8ab3820f
KC
2013
2014# Relocation on x86 needs some additional build support
845adf72
PA
2015config X86_NEED_RELOCS
2016 def_bool y
8ab3820f 2017 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2018
506f1d07 2019config PHYSICAL_ALIGN
a0215061 2020 hex "Alignment value to which kernel should be aligned"
8ab3820f 2021 default "0x200000"
a0215061
KC
2022 range 0x2000 0x1000000 if X86_32
2023 range 0x200000 0x1000000 if X86_64
8f9ca475 2024 ---help---
506f1d07
SR
2025 This value puts the alignment restrictions on physical address
2026 where kernel is loaded and run from. Kernel is compiled for an
2027 address which meets above alignment restriction.
2028
2029 If bootloader loads the kernel at a non-aligned address and
2030 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2031 address aligned to above value and run from there.
2032
2033 If bootloader loads the kernel at a non-aligned address and
2034 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2035 load address and decompress itself to the address it has been
2036 compiled for and run from there. The address for which kernel is
2037 compiled already meets above alignment restrictions. Hence the
2038 end result is that kernel runs from a physical address meeting
2039 above alignment restrictions.
2040
a0215061
KC
2041 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2042 this value must be a multiple of 0x200000.
2043
506f1d07
SR
2044 Don't change this unless you know what you are doing.
2045
0483e1fa
TG
2046config RANDOMIZE_MEMORY
2047 bool "Randomize the kernel memory sections"
2048 depends on X86_64
2049 depends on RANDOMIZE_BASE
2050 default RANDOMIZE_BASE
2051 ---help---
2052 Randomizes the base virtual address of kernel memory sections
2053 (physical memory mapping, vmalloc & vmemmap). This security feature
2054 makes exploits relying on predictable memory locations less reliable.
2055
2056 The order of allocations remains unchanged. Entropy is generated in
2057 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2058 configuration have in average 30,000 different possible virtual
2059 addresses for each memory section.
2060
6807c846 2061 If unsure, say Y.
0483e1fa 2062
90397a41
TG
2063config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2064 hex "Physical memory mapping padding" if EXPERT
2065 depends on RANDOMIZE_MEMORY
2066 default "0xa" if MEMORY_HOTPLUG
2067 default "0x0"
2068 range 0x1 0x40 if MEMORY_HOTPLUG
2069 range 0x0 0x40
2070 ---help---
2071 Define the padding in terabytes added to the existing physical
2072 memory size during kernel memory randomization. It is useful
2073 for memory hotplug support but reduces the entropy available for
2074 address randomization.
2075
2076 If unsure, leave at the default value.
2077
506f1d07 2078config HOTPLUG_CPU
7c13e6a3 2079 bool "Support for hot-pluggable CPUs"
40b31360 2080 depends on SMP
506f1d07 2081 ---help---
7c13e6a3
DS
2082 Say Y here to allow turning CPUs off and on. CPUs can be
2083 controlled through /sys/devices/system/cpu.
2084 ( Note: power management support will enable this option
2085 automatically on SMP systems. )
2086 Say N if you want to disable CPU hotplug.
506f1d07 2087
80aa1dff
FY
2088config BOOTPARAM_HOTPLUG_CPU0
2089 bool "Set default setting of cpu0_hotpluggable"
2090 default n
2c922cd0 2091 depends on HOTPLUG_CPU
80aa1dff
FY
2092 ---help---
2093 Set whether default state of cpu0_hotpluggable is on or off.
2094
2095 Say Y here to enable CPU0 hotplug by default. If this switch
2096 is turned on, there is no need to give cpu0_hotplug kernel
2097 parameter and the CPU0 hotplug feature is enabled by default.
2098
2099 Please note: there are two known CPU0 dependencies if you want
2100 to enable the CPU0 hotplug feature either by this switch or by
2101 cpu0_hotplug kernel parameter.
2102
2103 First, resume from hibernate or suspend always starts from CPU0.
2104 So hibernate and suspend are prevented if CPU0 is offline.
2105
2106 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2107 offline if any interrupt can not migrate out of CPU0. There may
2108 be other CPU0 dependencies.
2109
2110 Please make sure the dependencies are under your control before
2111 you enable this feature.
2112
2113 Say N if you don't want to enable CPU0 hotplug feature by default.
2114 You still can enable the CPU0 hotplug feature at boot by kernel
2115 parameter cpu0_hotplug.
2116
a71c8bc5
FY
2117config DEBUG_HOTPLUG_CPU0
2118 def_bool n
2119 prompt "Debug CPU0 hotplug"
2c922cd0 2120 depends on HOTPLUG_CPU
a71c8bc5
FY
2121 ---help---
2122 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2123 soon as possible and boots up userspace with CPU0 offlined. User
2124 can online CPU0 back after boot time.
2125
2126 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2127 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2128 compilation or giving cpu0_hotplug kernel parameter at boot.
2129
2130 If unsure, say N.
2131
506f1d07 2132config COMPAT_VDSO
b0b49f26
AL
2133 def_bool n
2134 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2135 depends on COMPAT_32
8f9ca475 2136 ---help---
b0b49f26
AL
2137 Certain buggy versions of glibc will crash if they are
2138 presented with a 32-bit vDSO that is not mapped at the address
2139 indicated in its segment table.
e84446de 2140
b0b49f26
AL
2141 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2142 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2143 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2144 the only released version with the bug, but OpenSUSE 9
2145 contains a buggy "glibc 2.3.2".
506f1d07 2146
b0b49f26
AL
2147 The symptom of the bug is that everything crashes on startup, saying:
2148 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2149
2150 Saying Y here changes the default value of the vdso32 boot
2151 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2152 This works around the glibc bug but hurts performance.
2153
2154 If unsure, say N: if you are compiling your own kernel, you
2155 are unlikely to be using a buggy version of glibc.
506f1d07 2156
3dc33bd3
KC
2157choice
2158 prompt "vsyscall table for legacy applications"
2159 depends on X86_64
2160 default LEGACY_VSYSCALL_EMULATE
2161 help
2162 Legacy user code that does not know how to find the vDSO expects
2163 to be able to issue three syscalls by calling fixed addresses in
2164 kernel space. Since this location is not randomized with ASLR,
2165 it can be used to assist security vulnerability exploitation.
2166
2167 This setting can be changed at boot time via the kernel command
2168 line parameter vsyscall=[native|emulate|none].
2169
2170 On a system with recent enough glibc (2.14 or newer) and no
2171 static binaries, you can say None without a performance penalty
2172 to improve security.
2173
2174 If unsure, select "Emulate".
2175
2176 config LEGACY_VSYSCALL_NATIVE
2177 bool "Native"
2178 help
2179 Actual executable code is located in the fixed vsyscall
2180 address mapping, implementing time() efficiently. Since
2181 this makes the mapping executable, it can be used during
2182 security vulnerability exploitation (traditionally as
2183 ROP gadgets). This configuration is not recommended.
2184
2185 config LEGACY_VSYSCALL_EMULATE
2186 bool "Emulate"
2187 help
2188 The kernel traps and emulates calls into the fixed
2189 vsyscall address mapping. This makes the mapping
2190 non-executable, but it still contains known contents,
2191 which could be used in certain rare security vulnerability
2192 exploits. This configuration is recommended when userspace
2193 still uses the vsyscall area.
2194
2195 config LEGACY_VSYSCALL_NONE
2196 bool "None"
2197 help
2198 There will be no vsyscall mapping at all. This will
2199 eliminate any risk of ASLR bypass due to the vsyscall
2200 fixed address mapping. Attempts to use the vsyscalls
2201 will be reported to dmesg, so that either old or
2202 malicious userspace programs can be identified.
2203
2204endchoice
2205
516cbf37
TB
2206config CMDLINE_BOOL
2207 bool "Built-in kernel command line"
8f9ca475 2208 ---help---
516cbf37
TB
2209 Allow for specifying boot arguments to the kernel at
2210 build time. On some systems (e.g. embedded ones), it is
2211 necessary or convenient to provide some or all of the
2212 kernel boot arguments with the kernel itself (that is,
2213 to not rely on the boot loader to provide them.)
2214
2215 To compile command line arguments into the kernel,
2216 set this option to 'Y', then fill in the
69711ca1 2217 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2218
2219 Systems with fully functional boot loaders (i.e. non-embedded)
2220 should leave this option set to 'N'.
2221
2222config CMDLINE
2223 string "Built-in kernel command string"
2224 depends on CMDLINE_BOOL
2225 default ""
8f9ca475 2226 ---help---
516cbf37
TB
2227 Enter arguments here that should be compiled into the kernel
2228 image and used at boot time. If the boot loader provides a
2229 command line at boot time, it is appended to this string to
2230 form the full kernel command line, when the system boots.
2231
2232 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2233 change this behavior.
2234
2235 In most cases, the command line (whether built-in or provided
2236 by the boot loader) should specify the device for the root
2237 file system.
2238
2239config CMDLINE_OVERRIDE
2240 bool "Built-in command line overrides boot loader arguments"
516cbf37 2241 depends on CMDLINE_BOOL
8f9ca475 2242 ---help---
516cbf37
TB
2243 Set this option to 'Y' to have the kernel ignore the boot loader
2244 command line, and use ONLY the built-in command line.
2245
2246 This is used to work around broken boot loaders. This should
2247 be set to 'N' under normal conditions.
2248
a5b9e5a2
AL
2249config MODIFY_LDT_SYSCALL
2250 bool "Enable the LDT (local descriptor table)" if EXPERT
2251 default y
2252 ---help---
2253 Linux can allow user programs to install a per-process x86
2254 Local Descriptor Table (LDT) using the modify_ldt(2) system
2255 call. This is required to run 16-bit or segmented code such as
2256 DOSEMU or some Wine programs. It is also used by some very old
2257 threading libraries.
2258
2259 Enabling this feature adds a small amount of overhead to
2260 context switches and increases the low-level kernel attack
2261 surface. Disabling it removes the modify_ldt(2) system call.
2262
2263 Saying 'N' here may make sense for embedded or server kernels.
2264
b700e7f0
SJ
2265source "kernel/livepatch/Kconfig"
2266
506f1d07
SR
2267endmenu
2268
2269config ARCH_ENABLE_MEMORY_HOTPLUG
2270 def_bool y
2271 depends on X86_64 || (X86_32 && HIGHMEM)
2272
35551053
GH
2273config ARCH_ENABLE_MEMORY_HOTREMOVE
2274 def_bool y
2275 depends on MEMORY_HOTPLUG
2276
e534c7c5 2277config USE_PERCPU_NUMA_NODE_ID
645a7919 2278 def_bool y
e534c7c5
LS
2279 depends on NUMA
2280
9491846f
KS
2281config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2282 def_bool y
2283 depends on X86_64 || X86_PAE
2284
c177c81e
NH
2285config ARCH_ENABLE_HUGEPAGE_MIGRATION
2286 def_bool y
2287 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2288
da85f865 2289menu "Power management and ACPI options"
e279b6c1
SR
2290
2291config ARCH_HIBERNATION_HEADER
3c2362e6 2292 def_bool y
e279b6c1 2293 depends on X86_64 && HIBERNATION
e279b6c1
SR
2294
2295source "kernel/power/Kconfig"
2296
2297source "drivers/acpi/Kconfig"
2298
efafc8b2
FT
2299source "drivers/sfi/Kconfig"
2300
a6b68076 2301config X86_APM_BOOT
6fc108a0 2302 def_bool y
282e5aab 2303 depends on APM
a6b68076 2304
e279b6c1
SR
2305menuconfig APM
2306 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2307 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2308 ---help---
2309 APM is a BIOS specification for saving power using several different
2310 techniques. This is mostly useful for battery powered laptops with
2311 APM compliant BIOSes. If you say Y here, the system time will be
2312 reset after a RESUME operation, the /proc/apm device will provide
2313 battery status information, and user-space programs will receive
2314 notification of APM "events" (e.g. battery status change).
2315
2316 If you select "Y" here, you can disable actual use of the APM
2317 BIOS by passing the "apm=off" option to the kernel at boot time.
2318
2319 Note that the APM support is almost completely disabled for
2320 machines with more than one CPU.
2321
2322 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2323 and more information, read <file:Documentation/power/apm-acpi.txt>
2324 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2325 <http://www.tldp.org/docs.html#howto>.
2326
2327 This driver does not spin down disk drives (see the hdparm(8)
2328 manpage ("man 8 hdparm") for that), and it doesn't turn off
2329 VESA-compliant "green" monitors.
2330
2331 This driver does not support the TI 4000M TravelMate and the ACER
2332 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2333 desktop machines also don't have compliant BIOSes, and this driver
2334 may cause those machines to panic during the boot phase.
2335
2336 Generally, if you don't have a battery in your machine, there isn't
2337 much point in using this driver and you should say N. If you get
2338 random kernel OOPSes or reboots that don't seem to be related to
2339 anything, try disabling/enabling this option (or disabling/enabling
2340 APM in your BIOS).
2341
2342 Some other things you should try when experiencing seemingly random,
2343 "weird" problems:
2344
2345 1) make sure that you have enough swap space and that it is
2346 enabled.
2347 2) pass the "no-hlt" option to the kernel
2348 3) switch on floating point emulation in the kernel and pass
2349 the "no387" option to the kernel
2350 4) pass the "floppy=nodma" option to the kernel
2351 5) pass the "mem=4M" option to the kernel (thereby disabling
2352 all but the first 4 MB of RAM)
2353 6) make sure that the CPU is not over clocked.
2354 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2355 8) disable the cache from your BIOS settings
2356 9) install a fan for the video card or exchange video RAM
2357 10) install a better fan for the CPU
2358 11) exchange RAM chips
2359 12) exchange the motherboard.
2360
2361 To compile this driver as a module, choose M here: the
2362 module will be called apm.
2363
2364if APM
2365
2366config APM_IGNORE_USER_SUSPEND
2367 bool "Ignore USER SUSPEND"
8f9ca475 2368 ---help---
e279b6c1
SR
2369 This option will ignore USER SUSPEND requests. On machines with a
2370 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2371 series notebooks, it is necessary to say Y because of a BIOS bug.
2372
2373config APM_DO_ENABLE
2374 bool "Enable PM at boot time"
2375 ---help---
2376 Enable APM features at boot time. From page 36 of the APM BIOS
2377 specification: "When disabled, the APM BIOS does not automatically
2378 power manage devices, enter the Standby State, enter the Suspend
2379 State, or take power saving steps in response to CPU Idle calls."
2380 This driver will make CPU Idle calls when Linux is idle (unless this
2381 feature is turned off -- see "Do CPU IDLE calls", below). This
2382 should always save battery power, but more complicated APM features
2383 will be dependent on your BIOS implementation. You may need to turn
2384 this option off if your computer hangs at boot time when using APM
2385 support, or if it beeps continuously instead of suspending. Turn
2386 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2387 T400CDT. This is off by default since most machines do fine without
2388 this feature.
2389
2390config APM_CPU_IDLE
dd8af076 2391 depends on CPU_IDLE
e279b6c1 2392 bool "Make CPU Idle calls when idle"
8f9ca475 2393 ---help---
e279b6c1
SR
2394 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2395 On some machines, this can activate improved power savings, such as
2396 a slowed CPU clock rate, when the machine is idle. These idle calls
2397 are made after the idle loop has run for some length of time (e.g.,
2398 333 mS). On some machines, this will cause a hang at boot time or
2399 whenever the CPU becomes idle. (On machines with more than one CPU,
2400 this option does nothing.)
2401
2402config APM_DISPLAY_BLANK
2403 bool "Enable console blanking using APM"
8f9ca475 2404 ---help---
e279b6c1
SR
2405 Enable console blanking using the APM. Some laptops can use this to
2406 turn off the LCD backlight when the screen blanker of the Linux
2407 virtual console blanks the screen. Note that this is only used by
2408 the virtual console screen blanker, and won't turn off the backlight
2409 when using the X Window system. This also doesn't have anything to
2410 do with your VESA-compliant power-saving monitor. Further, this
2411 option doesn't work for all laptops -- it might not turn off your
2412 backlight at all, or it might print a lot of errors to the console,
2413 especially if you are using gpm.
2414
2415config APM_ALLOW_INTS
2416 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2417 ---help---
e279b6c1
SR
2418 Normally we disable external interrupts while we are making calls to
2419 the APM BIOS as a measure to lessen the effects of a badly behaving
2420 BIOS implementation. The BIOS should reenable interrupts if it
2421 needs to. Unfortunately, some BIOSes do not -- especially those in
2422 many of the newer IBM Thinkpads. If you experience hangs when you
2423 suspend, try setting this to Y. Otherwise, say N.
2424
e279b6c1
SR
2425endif # APM
2426
bb0a56ec 2427source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2428
2429source "drivers/cpuidle/Kconfig"
2430
27471fdb
AH
2431source "drivers/idle/Kconfig"
2432
e279b6c1
SR
2433endmenu
2434
2435
2436menu "Bus options (PCI etc.)"
2437
2438config PCI
1ac97018 2439 bool "PCI support"
1c858087 2440 default y
8f9ca475 2441 ---help---
e279b6c1
SR
2442 Find out whether you have a PCI motherboard. PCI is the name of a
2443 bus system, i.e. the way the CPU talks to the other stuff inside
2444 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2445 VESA. If you have PCI, say Y, otherwise N.
2446
e279b6c1
SR
2447choice
2448 prompt "PCI access mode"
efefa6f6 2449 depends on X86_32 && PCI
e279b6c1
SR
2450 default PCI_GOANY
2451 ---help---
2452 On PCI systems, the BIOS can be used to detect the PCI devices and
2453 determine their configuration. However, some old PCI motherboards
2454 have BIOS bugs and may crash if this is done. Also, some embedded
2455 PCI-based systems don't have any BIOS at all. Linux can also try to
2456 detect the PCI hardware directly without using the BIOS.
2457
2458 With this option, you can specify how Linux should detect the
2459 PCI devices. If you choose "BIOS", the BIOS will be used,
2460 if you choose "Direct", the BIOS won't be used, and if you
2461 choose "MMConfig", then PCI Express MMCONFIG will be used.
2462 If you choose "Any", the kernel will try MMCONFIG, then the
2463 direct access method and falls back to the BIOS if that doesn't
2464 work. If unsure, go with the default, which is "Any".
2465
2466config PCI_GOBIOS
2467 bool "BIOS"
2468
2469config PCI_GOMMCONFIG
2470 bool "MMConfig"
2471
2472config PCI_GODIRECT
2473 bool "Direct"
2474
3ef0e1f8 2475config PCI_GOOLPC
76fb6570 2476 bool "OLPC XO-1"
3ef0e1f8
AS
2477 depends on OLPC
2478
2bdd1b03
AS
2479config PCI_GOANY
2480 bool "Any"
2481
e279b6c1
SR
2482endchoice
2483
2484config PCI_BIOS
3c2362e6 2485 def_bool y
efefa6f6 2486 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2487
2488# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2489config PCI_DIRECT
3c2362e6 2490 def_bool y
0aba496f 2491 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2492
2493config PCI_MMCONFIG
3c2362e6 2494 def_bool y
5f0db7a2 2495 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2496
3ef0e1f8 2497config PCI_OLPC
2bdd1b03
AS
2498 def_bool y
2499 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2500
b5401a96
AN
2501config PCI_XEN
2502 def_bool y
2503 depends on PCI && XEN
2504 select SWIOTLB_XEN
2505
e279b6c1 2506config PCI_DOMAINS
3c2362e6 2507 def_bool y
e279b6c1 2508 depends on PCI
e279b6c1
SR
2509
2510config PCI_MMCONFIG
2511 bool "Support mmconfig PCI config space access"
2512 depends on X86_64 && PCI && ACPI
2513
3f6ea84a 2514config PCI_CNB20LE_QUIRK
6a108a14 2515 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2516 depends on PCI
3f6ea84a
IS
2517 help
2518 Read the PCI windows out of the CNB20LE host bridge. This allows
2519 PCI hotplug to work on systems with the CNB20LE chipset which do
2520 not have ACPI.
2521
64a5fed6
BH
2522 There's no public spec for this chipset, and this functionality
2523 is known to be incomplete.
2524
2525 You should say N unless you know you need this.
2526
e279b6c1
SR
2527source "drivers/pci/Kconfig"
2528
3a495511
WBG
2529config ISA_BUS
2530 bool "ISA-style bus support on modern systems" if EXPERT
2531 select ISA_BUS_API
2532 help
2533 Enables ISA-style drivers on modern systems. This is necessary to
2534 support PC/104 devices on X86_64 platforms.
2535
2536 If unsure, say N.
2537
1c00f016 2538# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2539config ISA_DMA_API
1c00f016
DR
2540 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2541 default y
2542 help
2543 Enables ISA-style DMA support for devices requiring such controllers.
2544 If unsure, say Y.
e279b6c1 2545
51e68d05
LT
2546if X86_32
2547
e279b6c1
SR
2548config ISA
2549 bool "ISA support"
8f9ca475 2550 ---help---
e279b6c1
SR
2551 Find out whether you have ISA slots on your motherboard. ISA is the
2552 name of a bus system, i.e. the way the CPU talks to the other stuff
2553 inside your box. Other bus systems are PCI, EISA, MicroChannel
2554 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2555 newer boards don't support it. If you have ISA, say Y, otherwise N.
2556
2557config EISA
2558 bool "EISA support"
2559 depends on ISA
2560 ---help---
2561 The Extended Industry Standard Architecture (EISA) bus was
2562 developed as an open alternative to the IBM MicroChannel bus.
2563
2564 The EISA bus provided some of the features of the IBM MicroChannel
2565 bus while maintaining backward compatibility with cards made for
2566 the older ISA bus. The EISA bus saw limited use between 1988 and
2567 1995 when it was made obsolete by the PCI bus.
2568
2569 Say Y here if you are building a kernel for an EISA-based machine.
2570
2571 Otherwise, say N.
2572
2573source "drivers/eisa/Kconfig"
2574
e279b6c1
SR
2575config SCx200
2576 tristate "NatSemi SCx200 support"
8f9ca475 2577 ---help---
e279b6c1
SR
2578 This provides basic support for National Semiconductor's
2579 (now AMD's) Geode processors. The driver probes for the
2580 PCI-IDs of several on-chip devices, so its a good dependency
2581 for other scx200_* drivers.
2582
2583 If compiled as a module, the driver is named scx200.
2584
2585config SCx200HR_TIMER
2586 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2587 depends on SCx200
e279b6c1 2588 default y
8f9ca475 2589 ---help---
e279b6c1
SR
2590 This driver provides a clocksource built upon the on-chip
2591 27MHz high-resolution timer. Its also a workaround for
2592 NSC Geode SC-1100's buggy TSC, which loses time when the
2593 processor goes idle (as is done by the scheduler). The
2594 other workaround is idle=poll boot option.
2595
3ef0e1f8
AS
2596config OLPC
2597 bool "One Laptop Per Child support"
54008979 2598 depends on !X86_PAE
3c554946 2599 select GPIOLIB
dc3119e7 2600 select OF
45bb1674 2601 select OF_PROMTREE
b4e51854 2602 select IRQ_DOMAIN
8f9ca475 2603 ---help---
3ef0e1f8
AS
2604 Add support for detecting the unique features of the OLPC
2605 XO hardware.
2606
a3128588
DD
2607config OLPC_XO1_PM
2608 bool "OLPC XO-1 Power Management"
97c4cb71 2609 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2610 select MFD_CORE
bf1ebf00 2611 ---help---
97c4cb71 2612 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2613
cfee9597
DD
2614config OLPC_XO1_RTC
2615 bool "OLPC XO-1 Real Time Clock"
2616 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2617 ---help---
2618 Add support for the XO-1 real time clock, which can be used as a
2619 programmable wakeup source.
2620
7feda8e9
DD
2621config OLPC_XO1_SCI
2622 bool "OLPC XO-1 SCI extras"
d8d01a63 2623 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2624 depends on INPUT=y
d8d01a63 2625 select POWER_SUPPLY
7feda8e9
DD
2626 select GPIO_CS5535
2627 select MFD_CORE
2628 ---help---
2629 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2630 - EC-driven system wakeups
7feda8e9 2631 - Power button
7bc74b3d 2632 - Ebook switch
2cf2baea 2633 - Lid switch
e1040ac6
DD
2634 - AC adapter status updates
2635 - Battery status updates
7feda8e9 2636
a0f30f59
DD
2637config OLPC_XO15_SCI
2638 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2639 depends on OLPC && ACPI
2640 select POWER_SUPPLY
a0f30f59
DD
2641 ---help---
2642 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2643 - EC-driven system wakeups
2644 - AC adapter status updates
2645 - Battery status updates
bf1ebf00 2646
d4f3e350
EW
2647config ALIX
2648 bool "PCEngines ALIX System Support (LED setup)"
2649 select GPIOLIB
2650 ---help---
2651 This option enables system support for the PCEngines ALIX.
2652 At present this just sets up LEDs for GPIO control on
2653 ALIX2/3/6 boards. However, other system specific setup should
2654 get added here.
2655
2656 Note: You must still enable the drivers for GPIO and LED support
2657 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2658
2659 Note: You have to set alix.force=1 for boards with Award BIOS.
2660
da4e3302
PP
2661config NET5501
2662 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2663 select GPIOLIB
2664 ---help---
2665 This option enables system support for the Soekris Engineering net5501.
2666
3197059a
PP
2667config GEOS
2668 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2669 select GPIOLIB
2670 depends on DMI
2671 ---help---
2672 This option enables system support for the Traverse Technologies GEOS.
2673
7d029125
VD
2674config TS5500
2675 bool "Technologic Systems TS-5500 platform support"
2676 depends on MELAN
2677 select CHECK_SIGNATURE
2678 select NEW_LEDS
2679 select LEDS_CLASS
2680 ---help---
2681 This option enables system support for the Technologic Systems TS-5500.
2682
bc0120fd
SR
2683endif # X86_32
2684
23ac4ae8 2685config AMD_NB
e279b6c1 2686 def_bool y
0e152cd7 2687 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2688
2689source "drivers/pcmcia/Kconfig"
2690
388b78ad 2691config RAPIDIO
fdf90abc 2692 tristate "RapidIO support"
388b78ad
AB
2693 depends on PCI
2694 default n
2695 help
fdf90abc 2696 If enabled this option will include drivers and the core
388b78ad
AB
2697 infrastructure code to support RapidIO interconnect devices.
2698
2699source "drivers/rapidio/Kconfig"
2700
e3263ab3
DH
2701config X86_SYSFB
2702 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2703 help
2704 Firmwares often provide initial graphics framebuffers so the BIOS,
2705 bootloader or kernel can show basic video-output during boot for
2706 user-guidance and debugging. Historically, x86 used the VESA BIOS
2707 Extensions and EFI-framebuffers for this, which are mostly limited
2708 to x86.
2709 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2710 framebuffers so the new generic system-framebuffer drivers can be
2711 used on x86. If the framebuffer is not compatible with the generic
2712 modes, it is adverticed as fallback platform framebuffer so legacy
2713 drivers like efifb, vesafb and uvesafb can pick it up.
2714 If this option is not selected, all system framebuffers are always
2715 marked as fallback platform framebuffers as usual.
2716
2717 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2718 not be able to pick up generic system framebuffers if this option
2719 is selected. You are highly encouraged to enable simplefb as
2720 replacement if you select this option. simplefb can correctly deal
2721 with generic system framebuffers. But you should still keep vesafb
2722 and others enabled as fallback if a system framebuffer is
2723 incompatible with simplefb.
2724
2725 If unsure, say Y.
2726
e279b6c1
SR
2727endmenu
2728
2729
2730menu "Executable file formats / Emulations"
2731
2732source "fs/Kconfig.binfmt"
2733
2734config IA32_EMULATION
2735 bool "IA32 Emulation"
2736 depends on X86_64
39f88911 2737 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2738 select BINFMT_ELF
a97f52e6 2739 select COMPAT_BINFMT_ELF
39f88911 2740 select COMPAT_OLD_SIGACTION
8f9ca475 2741 ---help---
5fd92e65
L
2742 Include code to run legacy 32-bit programs under a
2743 64-bit kernel. You should likely turn this on, unless you're
2744 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2745
2746config IA32_AOUT
8f9ca475
IM
2747 tristate "IA32 a.out support"
2748 depends on IA32_EMULATION
2749 ---help---
2750 Support old a.out binaries in the 32bit emulation.
e279b6c1 2751
0bf62763 2752config X86_X32
6ea30386 2753 bool "x32 ABI for 64-bit mode"
9b54050b 2754 depends on X86_64
5fd92e65
L
2755 ---help---
2756 Include code to run binaries for the x32 native 32-bit ABI
2757 for 64-bit processors. An x32 process gets access to the
2758 full 64-bit register file and wide data path while leaving
2759 pointers at 32 bits for smaller memory footprint.
2760
2761 You will need a recent binutils (2.22 or later) with
2762 elf32_x86_64 support enabled to compile a kernel with this
2763 option set.
2764
953fee1d
IM
2765config COMPAT_32
2766 def_bool y
2767 depends on IA32_EMULATION || X86_32
2768 select HAVE_UID16
2769 select OLD_SIGSUSPEND3
2770
e279b6c1 2771config COMPAT
3c2362e6 2772 def_bool y
0bf62763 2773 depends on IA32_EMULATION || X86_X32
e279b6c1 2774
3120e25e 2775if COMPAT
e279b6c1 2776config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2777 def_bool y
e279b6c1
SR
2778
2779config SYSVIPC_COMPAT
3c2362e6 2780 def_bool y
3120e25e 2781 depends on SYSVIPC
3120e25e 2782endif
ee009e4a 2783
e279b6c1
SR
2784endmenu
2785
2786
e5beae16
KP
2787config HAVE_ATOMIC_IOMAP
2788 def_bool y
2789 depends on X86_32
2790
4692d77f
AR
2791config X86_DEV_DMA_OPS
2792 bool
83125a3a 2793 depends on X86_64 || STA2X11
4692d77f 2794
f7219a53
AR
2795config X86_DMA_REMAP
2796 bool
83125a3a 2797 depends on STA2X11
f7219a53 2798
e585513b
KS
2799config HAVE_GENERIC_GUP
2800 def_bool y
2801
e279b6c1
SR
2802source "net/Kconfig"
2803
2804source "drivers/Kconfig"
2805
2806source "drivers/firmware/Kconfig"
2807
2808source "fs/Kconfig"
2809
e279b6c1
SR
2810source "arch/x86/Kconfig.debug"
2811
2812source "security/Kconfig"
2813
2814source "crypto/Kconfig"
2815
edf88417
AK
2816source "arch/x86/kvm/Kconfig"
2817
e279b6c1 2818source "lib/Kconfig"