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Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 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
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080027 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020028 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070029 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080030 select ARCH_HAS_GCOV_PROFILE_ALL
Dan Williams96601ad2015-08-24 18:29:38 -040031 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060032 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020033 select ARCH_HAS_SG_CHAIN
Andrey Ryabininc6d30852016-01-20 15:00:55 -080034 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020035 select ARCH_HAVE_NMI_SAFE_CMPXCHG
36 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040037 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080038 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020039 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070040 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020041 select ARCH_SUPPORTS_INT128 if X86_64
42 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
43 select ARCH_USE_BUILTIN_BSWAP
44 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
45 select ARCH_USE_QUEUED_RWLOCKS
46 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070047 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020048 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010049 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020050 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
51 select ARCH_WANT_OPTIONAL_GPIOLIB
52 select BUILDTIME_EXTABLE_SORT
53 select CLKEVT_I8253
54 select CLKSRC_I8253 if X86_32
55 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
56 select CLOCKSOURCE_WATCHDOG
57 select CLONE_BACKWARDS if X86_32
58 select COMPAT_OLD_SIGACTION if IA32_EMULATION
59 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070060 select EDAC_ATOMIC_SCRUB
61 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020062 select GENERIC_CLOCKEVENTS
63 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
64 select GENERIC_CLOCKEVENTS_MIN_ADJUST
65 select GENERIC_CMOS_UPDATE
66 select GENERIC_CPU_AUTOPROBE
67 select GENERIC_EARLY_IOREMAP
68 select GENERIC_FIND_FIRST_BIT
69 select GENERIC_IOMAP
70 select GENERIC_IRQ_PROBE
71 select GENERIC_IRQ_SHOW
72 select GENERIC_PENDING_IRQ if SMP
73 select GENERIC_SMP_IDLE_THREAD
74 select GENERIC_STRNCPY_FROM_USER
75 select GENERIC_STRNLEN_USER
76 select GENERIC_TIME_VSYSCALL
77 select HAVE_ACPI_APEI if ACPI
78 select HAVE_ACPI_APEI_NMI if ACPI
79 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
80 select HAVE_AOUT if X86_32
81 select HAVE_ARCH_AUDITSYSCALL
82 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
83 select HAVE_ARCH_JUMP_LABEL
84 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
85 select HAVE_ARCH_KGDB
86 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080087 select HAVE_ARCH_MMAP_RND_BITS if MMU
88 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020089 select HAVE_ARCH_SECCOMP_FILTER
90 select HAVE_ARCH_SOFT_DIRTY if X86_64
91 select HAVE_ARCH_TRACEHOOK
92 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
93 select HAVE_BPF_JIT if X86_64
94 select HAVE_CC_STACKPROTECTOR
95 select HAVE_CMPXCHG_DOUBLE
96 select HAVE_CMPXCHG_LOCAL
97 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070098 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +020099 select HAVE_C_RECORDMCOUNT
100 select HAVE_DEBUG_KMEMLEAK
101 select HAVE_DEBUG_STACKOVERFLOW
102 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700103 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400104 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900105 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700106 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Ingo Molnar6471b822015-06-03 10:00:13 +0200107 select HAVE_FENTRY if X86_64
108 select HAVE_FTRACE_MCOUNT_RECORD
109 select HAVE_FUNCTION_GRAPH_FP_TEST
110 select HAVE_FUNCTION_GRAPH_TRACER
111 select HAVE_FUNCTION_TRACER
112 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530113 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200114 select HAVE_IDE
115 select HAVE_IOREMAP_PROT
116 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
118 select HAVE_KERNEL_BZIP2
119 select HAVE_KERNEL_GZIP
120 select HAVE_KERNEL_LZ4
121 select HAVE_KERNEL_LZMA
122 select HAVE_KERNEL_LZO
123 select HAVE_KERNEL_XZ
124 select HAVE_KPROBES
125 select HAVE_KPROBES_ON_FTRACE
126 select HAVE_KRETPROBES
127 select HAVE_KVM
128 select HAVE_LIVEPATCH if X86_64
129 select HAVE_MEMBLOCK
130 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200131 select HAVE_MIXED_BREAKPOINTS_REGS
Ingo Molnar6471b822015-06-03 10:00:13 +0200132 select HAVE_OPROFILE
133 select HAVE_OPTPROBES
134 select HAVE_PCSPKR_PLATFORM
135 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200136 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200137 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200138 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200139 select HAVE_REGS_AND_STACK_ACCESS_API
140 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400141 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200142 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300143 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100144 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200145 select MODULES_USE_ELF_RELA if X86_64
146 select MODULES_USE_ELF_REL if X86_32
147 select OLD_SIGACTION if X86_32
148 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
149 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500150 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200151 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500152 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200153 select SYSCTL_EXCEPTION_TRACE
154 select USER_STACKTRACE_SUPPORT
155 select VIRT_TO_BUS
156 select X86_DEV_DMA_OPS if X86_64
157 select X86_FEATURE_NAMES if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530158
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200159config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100160 def_bool y
161 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200162
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200163config PERF_EVENTS_INTEL_UNCORE
164 def_bool y
Peter Zijlstra (Intel)ce5686d2014-10-29 11:17:04 +0100165 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200166
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700167config OUTPUT_FORMAT
168 string
169 default "elf32-i386" if X86_32
170 default "elf64-x86-64" if X86_64
171
Sam Ravnborg73531902008-05-25 23:03:18 +0200172config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200173 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200174 default "arch/x86/configs/i386_defconfig" if X86_32
175 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200176
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100177config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100178 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100179
180config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100181 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100182
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100183config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100184 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100185
Daniel Cashman9e08f572016-01-14 15:20:06 -0800186config ARCH_MMAP_RND_BITS_MIN
187 default 28 if 64BIT
188 default 8
189
190config ARCH_MMAP_RND_BITS_MAX
191 default 32 if 64BIT
192 default 16
193
194config ARCH_MMAP_RND_COMPAT_BITS_MIN
195 default 8
196
197config ARCH_MMAP_RND_COMPAT_BITS_MAX
198 default 16
199
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100200config SBUS
201 bool
202
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800203config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100204 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400205 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800206
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700207config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700208 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700209
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100210config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100211 def_bool y
212 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100213
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100214config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100215 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100216 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000217 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
218
219config GENERIC_BUG_RELATIVE_POINTERS
220 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100221
222config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100223 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100224
225config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100226 def_bool y
227 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100228
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100229config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100230 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100231
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100232config GENERIC_CALIBRATE_DELAY
233 def_bool y
234
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800235config ARCH_HAS_CPU_RELAX
236 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100237
Pekka Enberg1b27d052008-04-28 02:12:22 -0700238config ARCH_HAS_CACHE_LINE_SIZE
239 def_bool y
240
Mike Travisdd5af902008-01-30 13:33:32 +0100241config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900242 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100243
Tejun Heo08fc4582009-08-14 15:00:49 +0900244config NEED_PER_CPU_EMBED_FIRST_CHUNK
245 def_bool y
246
247config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900248 def_bool y
249
Johannes Berg801e4062007-12-08 02:12:39 +0100250config ARCH_HIBERNATION_POSSIBLE
251 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100252
Johannes Bergf4cb5702007-12-08 02:14:00 +0100253config ARCH_SUSPEND_POSSIBLE
254 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100255
Steve Cappercfe28c52013-04-29 14:29:48 +0100256config ARCH_WANT_HUGE_PMD_SHARE
257 def_bool y
258
Steve Capper53313b22013-04-30 08:03:42 +0100259config ARCH_WANT_GENERAL_HUGETLB
260 def_bool y
261
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100262config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000263 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100264
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100265config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000266 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100267
Ingo Molnar765c68b2008-04-09 11:03:37 +0200268config ARCH_SUPPORTS_OPTIMIZED_INLINING
269 def_bool y
270
Akinobu Mita6a11f752009-03-31 15:23:17 -0700271config ARCH_SUPPORTS_DEBUG_PAGEALLOC
272 def_bool y
273
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300274config KASAN_SHADOW_OFFSET
275 hex
276 depends on KASAN
277 default 0xdffffc0000000000
278
Shane Wang69575d32009-09-01 18:25:07 -0700279config HAVE_INTEL_TXT
280 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700281 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700282
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100283config X86_32_SMP
284 def_bool y
285 depends on X86_32 && SMP
286
287config X86_64_SMP
288 def_bool y
289 depends on X86_64 && SMP
290
Tejun Heoccbeed32009-02-09 22:17:40 +0900291config X86_32_LAZY_GS
292 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900293 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900294
Borislav Petkovd61931d2010-03-05 17:34:46 +0100295config ARCH_HWEIGHT_CFLAGS
296 string
297 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
298 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
299
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530300config ARCH_SUPPORTS_UPROBES
301 def_bool y
302
Rob Herringd20642f2014-04-18 17:19:54 -0500303config FIX_EARLYCON_MEM
304 def_bool y
305
Kees Cook9ccaf772016-02-17 14:41:14 -0800306config DEBUG_RODATA
307 def_bool y
308
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700309config PGTABLE_LEVELS
310 int
311 default 4 if X86_64
312 default 3 if X86_PAE
313 default 2
314
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100315source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700316source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100317
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100318menu "Processor type and features"
319
Randy Dunlap5ee71532012-01-16 11:57:18 -0800320config ZONE_DMA
321 bool "DMA memory allocation support" if EXPERT
322 default y
323 help
324 DMA memory allocation support allows devices with less than 32-bit
325 addressing to allocate within the first 16MB of address space.
326 Disable if no such devices will be used.
327
328 If unsure, say Y.
329
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100330config SMP
331 bool "Symmetric multi-processing support"
332 ---help---
333 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800334 a system with only one CPU, say N. If you have a system with more
335 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100336
Robert Graffham4a474152014-01-23 15:55:29 -0800337 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100338 machines, but will use only one CPU of a multiprocessor machine. If
339 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800340 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100341 will run faster if you say N here.
342
343 Note that if you say Y here and choose architecture "586" or
344 "Pentium" under "Processor family", the kernel will not work on 486
345 architectures. Similarly, multiprocessor kernels for the "PPro"
346 architecture may not work on all Pentium based boards.
347
348 People using multiprocessor machines who say Y here should also say
349 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
350 Management" code will be disabled if you say Y here.
351
Paul Bolle395cf962011-08-15 02:02:26 +0200352 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100353 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
354 <http://www.tldp.org/docs.html#howto>.
355
356 If you don't know what to do here, say N.
357
Josh Triplett9def39be2013-10-30 08:09:45 -0700358config X86_FEATURE_NAMES
359 bool "Processor feature human-readable names" if EMBEDDED
360 default y
361 ---help---
362 This option compiles in a table of x86 feature bits and corresponding
363 names. This is required to support /proc/cpuinfo and a few kernel
364 messages. You can disable this to save space, at the expense of
365 making those few kernel messages show numeric feature bits instead.
366
367 If in doubt, say Y.
368
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100369config X86_FAST_FEATURE_TESTS
370 bool "Fast CPU feature tests" if EMBEDDED
371 default y
372 ---help---
373 Some fast-paths in the kernel depend on the capabilities of the CPU.
374 Say Y here for the kernel to patch in the appropriate code at runtime
375 based on the capabilities of the CPU. The infrastructure for patching
376 code at runtime takes up some additional space; space-constrained
377 embedded systems may wish to say N here to produce smaller, slightly
378 slower code.
379
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800380config X86_X2APIC
381 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200382 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800383 ---help---
384 This enables x2apic support on CPUs that have this feature.
385
386 This allows 32-bit apic IDs (so it can support very large systems),
387 and accesses the local apic via MSRs not via mmio.
388
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800389 If you don't know what to do here, say N.
390
Yinghai Lu6695c852008-06-19 12:13:09 -0700391config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700392 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000393 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200394 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100395 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700396 For old smp systems that do not have proper acpi support. Newer systems
397 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700398
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800399config X86_BIGSMP
400 bool "Support for big SMP systems with more than 8 CPUs"
401 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100402 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800403 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100404
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000405config GOLDFISH
406 def_bool y
407 depends on X86_GOLDFISH
408
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800409if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800410config X86_EXTENDED_PLATFORM
411 bool "Support for extended (non-PC) x86 platforms"
412 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100413 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100414 If you disable this option then the kernel will only support
415 standard PC platforms. (which covers the vast majority of
416 systems out there.)
417
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800418 If you enable this option then you'll be able to select support
419 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100420 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800421 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800422 RDC R-321x SoC
423 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200424 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200425 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100426
427 If you have one of these systems, or if you want to build a
428 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800429endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100430
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800431if X86_64
432config X86_EXTENDED_PLATFORM
433 bool "Support for extended (non-PC) x86 platforms"
434 default y
435 ---help---
436 If you disable this option then the kernel will only support
437 standard PC platforms. (which covers the vast majority of
438 systems out there.)
439
440 If you enable this option then you'll be able to select support
441 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b2011-12-06 00:07:26 +0800442 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800443 ScaleMP vSMP
444 SGI Ultraviolet
445
446 If you have one of these systems, or if you want to build a
447 generic distribution kernel, say Y here - otherwise say N.
448endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800449# This is an alphabetically sorted list of 64 bit extended platforms
450# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b2011-12-06 00:07:26 +0800451config X86_NUMACHIP
452 bool "Numascale NumaChip"
453 depends on X86_64
454 depends on X86_EXTENDED_PLATFORM
455 depends on NUMA
456 depends on SMP
457 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700458 depends on PCI_MMCONFIG
Steffen Persvold44b111b2011-12-06 00:07:26 +0800459 ---help---
460 Adds support for Numascale NumaChip large-SMP systems. Needed to
461 enable more than ~168 cores.
462 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100463
Ingo Molnar6a485652009-01-27 18:29:13 +0100464config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800465 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100466 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100467 select PARAVIRT
468 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800469 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300470 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100471 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100472 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
473 supposed to run on these EM64T-based machines. Only choose this option
474 if you have one of these machines.
475
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800476config X86_UV
477 bool "SGI Ultraviolet"
478 depends on X86_64
479 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500480 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800481 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700482 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200483 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800484 ---help---
485 This option is needed in order to support SGI Ultraviolet systems.
486 If you don't have one of these, you should say N here.
487
488# Following is an alphabetically sorted list of 32 bit extended platforms
489# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100490
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000491config X86_GOLDFISH
492 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100493 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000494 ---help---
495 Enable support for the Goldfish virtual platform used primarily
496 for Android development. Unless you are building for the Android
497 Goldfish emulator say N here.
498
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800499config X86_INTEL_CE
500 bool "CE4100 TV platform"
501 depends on PCI
502 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800503 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800504 depends on X86_32
505 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800506 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100507 select OF
508 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800509 ---help---
510 Select for the Intel CE media processor (CE4100) SOC.
511 This option compiles in support for the CE4100 SOC for settop
512 boxes and media devices.
513
David Cohen4cb9b002013-12-16 17:37:26 -0800514config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100515 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100516 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800517 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000518 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200519 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000520 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000521 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800522 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000523 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000524 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000525 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000526 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000527 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800528 Select to build a kernel capable of supporting Intel MID (Mobile
529 Internet Device) platform systems which do not have the PCI legacy
530 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000531
David Cohen4cb9b002013-12-16 17:37:26 -0800532 Intel MID platforms are based on an Intel processor and chipset which
533 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100534
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000535config X86_INTEL_QUARK
536 bool "Intel Quark platform support"
537 depends on X86_32
538 depends on X86_EXTENDED_PLATFORM
539 depends on X86_PLATFORM_DEVICES
540 depends on X86_TSC
541 depends on PCI
542 depends on PCI_GOANY
543 depends on X86_IO_APIC
544 select IOSF_MBI
545 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200546 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000547 ---help---
548 Select to include support for Quark X1000 SoC.
549 Say Y here if you have a Quark based system such as the Arduino
550 compatible Intel Galileo.
551
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000552config X86_INTEL_LPSS
553 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100554 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000555 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300556 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100557 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000558 ---help---
559 Select to build support for Intel Low Power Subsystem such as
560 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300561 things like clock tree (common clock framework) and pincontrol
562 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000563
Ken Xue92082a82015-02-06 08:27:51 +0800564config X86_AMD_PLATFORM_DEVICE
565 bool "AMD ACPI2Platform devices support"
566 depends on ACPI
567 select COMMON_CLK
568 select PINCTRL
569 ---help---
570 Select to interpret AMD specific ACPI device to platform device
571 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
572 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
573 implemented under PINCTRL subsystem.
574
David E. Boxced3ce72014-09-17 22:13:50 -0700575config IOSF_MBI
576 tristate "Intel SoC IOSF Sideband support for SoC platforms"
577 depends on PCI
578 ---help---
579 This option enables sideband register access support for Intel SoC
580 platforms. On these platforms the IOSF sideband is used in lieu of
581 MSR's for some register accesses, mostly but not limited to thermal
582 and power. Drivers may query the availability of this device to
583 determine if they need the sideband in order to work on these
584 platforms. The sideband is available on the following SoC products.
585 This list is not meant to be exclusive.
586 - BayTrail
587 - Braswell
588 - Quark
589
590 You should say Y if you are running a kernel on one of these SoC's.
591
David E. Boxed2226b2014-09-17 22:13:51 -0700592config IOSF_MBI_DEBUG
593 bool "Enable IOSF sideband access through debugfs"
594 depends on IOSF_MBI && DEBUG_FS
595 ---help---
596 Select this option to expose the IOSF sideband access registers (MCR,
597 MDR, MCRX) through debugfs to write and read register information from
598 different units on the SoC. This is most useful for obtaining device
599 state information for debug and analysis. As this is a general access
600 mechanism, users of this option would have specific knowledge of the
601 device they want to access.
602
603 If you don't require the option or are in doubt, say N.
604
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800605config X86_RDC321X
606 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100607 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800608 depends on X86_EXTENDED_PLATFORM
609 select M486
610 select X86_REBOOTFIXUPS
611 ---help---
612 This option is needed for RDC R-321x system-on-chip, also known
613 as R-8610-(G).
614 If you don't have one of these chips, you should say N here.
615
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100616config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100617 bool "Support non-standard 32-bit SMP architectures"
618 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800619 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100620 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800621 This option compiles in the bigsmp and STA2X11 default
622 subarchitectures. It is intended for a generic binary
623 kernel. If you select them all, kernel will probe it one by
624 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700625
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800626# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700627
Linus Torvaldsd949f362009-09-26 09:35:07 -0700628config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100629 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700630 # MCE code calls memory_failure():
631 depends on X86_MCE
632 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700633 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
634 depends on X86_64 || !SPARSEMEM
635 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700636
Alessandro Rubini83125a32012-04-04 19:40:21 +0200637config STA2X11
638 bool "STA2X11 Companion Chip Support"
639 depends on X86_32_NON_STANDARD && PCI
640 select X86_DEV_DMA_OPS
641 select X86_DMA_REMAP
642 select SWIOTLB
643 select MFD_STA2X11
644 select ARCH_REQUIRE_GPIOLIB
645 default n
646 ---help---
647 This adds support for boards based on the STA2X11 IO-Hub,
648 a.k.a. "ConneXt". The chip is used in place of the standard
649 PC chipset, so all "standard" peripherals are missing. If this
650 option is selected the kernel will still be able to boot on
651 standard PC machines.
652
Shérab82148d12010-09-25 06:06:57 +0200653config X86_32_IRIS
654 tristate "Eurobraille/Iris poweroff module"
655 depends on X86_32
656 ---help---
657 The Iris machines from EuroBraille do not have APM or ACPI support
658 to shut themselves down properly. A special I/O sequence is
659 needed to do so, which is what this module does at
660 kernel shutdown.
661
662 This is only for Iris machines from EuroBraille.
663
664 If unused, say N.
665
Ingo Molnarae1e9132008-11-11 09:05:16 +0100666config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100667 def_bool y
668 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800669 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100670 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100671 Calculate simpler /proc/<PID>/wchan values. If this option
672 is disabled then wchan values will recurse back to the
673 caller function. This provides more accurate wchan values,
674 at the expense of slightly more scheduling overhead.
675
676 If in doubt, say "Y".
677
Borislav Petkov6276a072013-03-04 21:20:21 +0100678menuconfig HYPERVISOR_GUEST
679 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100680 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100681 Say Y here to enable options for running Linux under various hyper-
682 visors. This option enables basic hypervisor detection and platform
683 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100684
Borislav Petkov6276a072013-03-04 21:20:21 +0100685 If you say N, all options in this submenu will be skipped and
686 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100687
Borislav Petkov6276a072013-03-04 21:20:21 +0100688if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100689
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100690config PARAVIRT
691 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100692 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100693 This changes the kernel so it can modify itself when it is run
694 under a hypervisor, potentially improving performance significantly
695 over full virtualization. However, when run without a hypervisor
696 the kernel is theoretically slower and slightly larger.
697
Borislav Petkov6276a072013-03-04 21:20:21 +0100698config PARAVIRT_DEBUG
699 bool "paravirt-ops debugging"
700 depends on PARAVIRT && DEBUG_KERNEL
701 ---help---
702 Enable to debug paravirt_ops internals. Specifically, BUG if
703 a paravirt_op is missing when it is called.
704
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700705config PARAVIRT_SPINLOCKS
706 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700707 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200708 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700709 ---help---
710 Paravirtualized spinlocks allow a pvops backend to replace the
711 spinlock implementation with something virtualization-friendly
712 (for example, block the virtual CPU rather than spinning).
713
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530714 It has a minimal impact on native kernels and gives a nice performance
715 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700716
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530717 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700718
Waiman Long45e898b2015-11-09 19:09:25 -0500719config QUEUED_LOCK_STAT
720 bool "Paravirt queued spinlock statistics"
721 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
722 ---help---
723 Enable the collection of statistical data on the slowpath
724 behavior of paravirtualized queued spinlocks and report
725 them on debugfs.
726
Borislav Petkov6276a072013-03-04 21:20:21 +0100727source "arch/x86/xen/Kconfig"
728
729config KVM_GUEST
730 bool "KVM Guest support (including kvmclock)"
731 depends on PARAVIRT
732 select PARAVIRT_CLOCK
733 default y
734 ---help---
735 This option enables various optimizations for running under the KVM
736 hypervisor. It includes a paravirtualized clock, so that instead
737 of relying on a PIT (or probably other) emulation by the
738 underlying device model, the host provides the guest with
739 timing infrastructure such as time of day, and system time
740
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530741config KVM_DEBUG_FS
742 bool "Enable debug information for KVM Guests in debugfs"
743 depends on KVM_GUEST && DEBUG_FS
744 default n
745 ---help---
746 This option enables collection of various statistics for KVM guest.
747 Statistics are displayed in debugfs filesystem. Enabling this option
748 may incur significant overhead.
749
Borislav Petkov6276a072013-03-04 21:20:21 +0100750source "arch/x86/lguest/Kconfig"
751
752config PARAVIRT_TIME_ACCOUNTING
753 bool "Paravirtual steal time accounting"
754 depends on PARAVIRT
755 default n
756 ---help---
757 Select this option to enable fine granularity task steal time
758 accounting. Time spent executing other tasks in parallel with
759 the current vCPU is discounted from the vCPU power. To account for
760 that, there can be a small performance impact.
761
762 If in doubt, say N here.
763
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200764config PARAVIRT_CLOCK
765 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200766
Borislav Petkov6276a072013-03-04 21:20:21 +0100767endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400768
Yinghai Lu08677212010-02-10 01:20:20 -0800769config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700770 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800771
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100772source "arch/x86/Kconfig.cpu"
773
774config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100775 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100776 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100777 ---help---
778 Use the IA-PC HPET (High Precision Event Timer) to manage
779 time in preference to the PIT and RTC, if a HPET is
780 present.
781 HPET is the next generation timer replacing legacy 8254s.
782 The HPET provides a stable time base on SMP
783 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200784 as it is off-chip. The interface used is documented
785 in the HPET spec, revision 1.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100786
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100787 You can safely choose Y here. However, HPET will only be
788 activated if the platform and the BIOS support this feature.
789 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100790
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100791 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100792
793config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100794 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800795 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100796
Jacob Panbb24c472009-09-02 07:37:17 -0700797config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000798 def_bool y if X86_INTEL_MID
799 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100800 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000801 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700802 help
803 APB timer is the replacement for 8254, HPET on X86 MID platforms.
804 The APBT provides a stable time base on SMP
805 systems, unlike the TSC, but it is more expensive to access,
806 as it is off-chip. APB timers are always running regardless of CPU
807 C states, they are used as per CPU clockevent device when possible.
808
David Rientjes6a108a12011-01-20 14:44:16 -0800809# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100810# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700811config DMI
812 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800813 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800814 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100815 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700816 Enabled scanning of DMI to identify machine quirks. Say Y
817 here unless you have verified that your setup is not
818 affected by entries in the DMI blacklist. Required by PNP
819 BIOS code.
820
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100821config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700822 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100823 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200824 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100825 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200826 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
827 GART based hardware IOMMUs.
828
829 The GART supports full DMA access for devices with 32-bit access
830 limitations, on systems with more than 3 GB. This is usually needed
831 for USB, sound, many IDE/SATA chipsets and some other devices.
832
833 Newer systems typically have a modern AMD IOMMU, supported via
834 the CONFIG_AMD_IOMMU=y config option.
835
836 In normal configurations this driver is only active when needed:
837 there's more than 3 GB of memory and the system contains a
838 32-bit limited device.
839
840 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100841
842config CALGARY_IOMMU
843 bool "IBM Calgary IOMMU support"
844 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700845 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100846 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100847 Support for hardware IOMMUs in IBM's xSeries x366 and x460
848 systems. Needed to run systems with more than 3GB of memory
849 properly with 32-bit PCI devices that do not support DAC
850 (Double Address Cycle). Calgary also supports bus level
851 isolation, where all DMAs pass through the IOMMU. This
852 prevents them from going anywhere except their intended
853 destination. This catches hard-to-find kernel bugs and
854 mis-behaving drivers and devices that do not use the DMA-API
855 properly to set up their DMA buffers. The IOMMU can be
856 turned off at boot time with the iommu=off parameter.
857 Normally the kernel will make the right choice by itself.
858 If unsure, say Y.
859
860config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100861 def_bool y
862 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100863 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100864 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100865 Should Calgary be enabled by default? if you choose 'y', Calgary
866 will be used (if it exists). If you choose 'n', Calgary will not be
867 used even if it exists. If you choose 'n' and would like to use
868 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
869 If unsure, say Y.
870
871# need this always selected by IOMMU for the VIA workaround
872config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100873 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100874 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100875 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700876 which don't have a hardware IOMMU. Using this PCI devices
877 which can only access 32-bits of memory can be used on systems
878 with more than 3 GB of memory.
879 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100880
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700881config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100882 def_bool y
883 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700884
Mike Travis1184dc22008-05-12 21:21:12 +0200885config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200886 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700887 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800888 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100889 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200890 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200891 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100892
893config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800894 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400895 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500896 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500897 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800898 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500899 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800900 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300901 default "8" if SMP && X86_32
902 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100903 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100904 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500905 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300906 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100907 minimum value which makes sense is 2.
908
909 This is purely to save memory - each supported CPU adds
910 approximately eight kilobytes to the kernel image.
911
912config SCHED_SMT
913 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200914 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100915 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100916 SMT scheduler support improves the CPU scheduler's decision making
917 when dealing with Intel Pentium 4 chips with HyperThreading at a
918 cost of slightly increased overhead in some places. If unsure say
919 N here.
920
921config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100922 def_bool y
923 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200924 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100925 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100926 Multi-core scheduler support improves the CPU scheduler's decision
927 making when dealing with multi-core CPU chips at a cost of slightly
928 increased overhead in some places. If unsure say N here.
929
930source "kernel/Kconfig.preempt"
931
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000932config UP_LATE_INIT
933 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100934 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000935
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100936config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000937 bool "Local APIC support on uniprocessors" if !PCI_MSI
938 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000939 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100940 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100941 A local APIC (Advanced Programmable Interrupt Controller) is an
942 integrated interrupt controller in the CPU. If you have a single-CPU
943 system which has a processor with a local APIC, you can say Y here to
944 enable and use it. If you say Y here even though your machine doesn't
945 have a local APIC, then the kernel will still run with no slowdown at
946 all. The local APIC supports CPU-generated self-interrupts (timer,
947 performance counters), and the NMI watchdog which detects hard
948 lockups.
949
950config X86_UP_IOAPIC
951 bool "IO-APIC support on uniprocessors"
952 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100953 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100954 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
955 SMP-capable replacement for PC-style interrupt controllers. Most
956 SMP systems and many recent uniprocessor systems have one.
957
958 If you have a single-CPU system with an IO-APIC, you can say Y here
959 to use it. If you say Y here even though your machine doesn't have
960 an IO-APIC, then the kernel will still run with no slowdown at all.
961
962config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100963 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200964 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800965 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800966 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100967
968config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000969 def_bool y
970 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100971
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200972config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
973 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200974 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100975 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200976 This option enables a workaround that fixes a source of
977 spurious interrupts. This is recommended when threaded
978 interrupt handling is used on systems where the generation of
979 superfluous "boot interrupts" cannot be disabled.
980
981 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
982 entry in the chipset's IO-APIC is masked (as, e.g. the RT
983 kernel does during interrupt handling). On chipsets where this
984 boot IRQ generation cannot be disabled, this workaround keeps
985 the original IRQ line masked so that only the equivalent "boot
986 IRQ" is delivered to the CPUs. The workaround also tells the
987 kernel to set up the IRQ handler on the boot IRQ line. In this
988 way only one interrupt is delivered to the kernel. Otherwise
989 the spurious second interrupt may cause the kernel to bring
990 down (vital) interrupt lines.
991
992 Only affects "broken" chipsets. Interrupt sharing may be
993 increased on these systems.
994
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100995config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200996 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +0200997 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +0200998 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100999 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001000 Machine Check support allows the processor to notify the
1001 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001002 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001003 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001004
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001005config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001006 def_bool y
1007 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001008 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001009 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001010 Additional support for intel specific MCE features such as
1011 the thermal monitor.
1012
1013config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001014 def_bool y
1015 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001016 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001017 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001018 Additional support for AMD specific MCE features such as
1019 the DRAM Error Threshold.
1020
Andi Kleen4efc0672009-04-28 19:07:31 +02001021config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001022 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001023 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001024 ---help---
1025 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001026 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001027 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001028
Andi Kleenb2762682009-02-12 13:49:31 +01001029config X86_MCE_THRESHOLD
1030 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001031 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001032
Andi Kleenea149b32009-04-29 19:31:00 +02001033config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001034 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001035 tristate "Machine check injector support"
1036 ---help---
1037 Provide support for injecting machine checks for testing purposes.
1038 If you don't know what a machine check is and you don't do kernel
1039 QA it is safe to say n.
1040
Andi Kleen4efc0672009-04-28 19:07:31 +02001041config X86_THERMAL_VECTOR
1042 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001043 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001044
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001045config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001046 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001047 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001048 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001049 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001050 This option allows user programs to put the CPU into V8086
1051 mode, which is an 80286-era approximation of 16-bit real mode.
1052
1053 Some very old versions of X and/or vbetool require this option
1054 for user mode setting. Similarly, DOSEMU will use it if
1055 available to accelerate real mode DOS programs. However, any
1056 recent version of DOSEMU, X, or vbetool should be fully
1057 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001058 fall back to software emulation. Nevertheless, if you are using
1059 a 16-bit DOS program where 16-bit performance matters, vm86
1060 mode might be faster than emulation and you might want to
1061 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001062
Ingo Molnar1e642812015-09-05 08:58:10 +02001063 Note that any app that works on a 64-bit kernel is unlikely to
1064 need this option, as 64-bit kernels don't, and can't, support
1065 V8086 mode. This option is also unrelated to 16-bit protected
1066 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001067
Ingo Molnar1e642812015-09-05 08:58:10 +02001068 Enabling this option increases the complexity of the kernel
1069 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001070
Ingo Molnar1e642812015-09-05 08:58:10 +02001071 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001072
1073config VM86
1074 bool
1075 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001076
1077config X86_16BIT
1078 bool "Enable support for 16-bit segments" if EXPERT
1079 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001080 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001081 ---help---
1082 This option is required by programs like Wine to run 16-bit
1083 protected mode legacy code on x86 processors. Disabling
1084 this option saves about 300 bytes on i386, or around 6K text
1085 plus 16K runtime memory on x86-64,
1086
1087config X86_ESPFIX32
1088 def_bool y
1089 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001090
H. Peter Anvin197725d2014-05-04 10:00:49 -07001091config X86_ESPFIX64
1092 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001093 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001094
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001095config X86_VSYSCALL_EMULATION
1096 bool "Enable vsyscall emulation" if EXPERT
1097 default y
1098 depends on X86_64
1099 ---help---
1100 This enables emulation of the legacy vsyscall page. Disabling
1101 it is roughly equivalent to booting with vsyscall=none, except
1102 that it will also disable the helpful warning if a program
1103 tries to use a vsyscall. With this option set to N, offending
1104 programs will just segfault, citing addresses of the form
1105 0xffffffffff600?00.
1106
1107 This option is required by many programs built before 2013, and
1108 care should be used even with newer programs if set to N.
1109
1110 Disabling this option saves about 7K of kernel size and
1111 possibly 4K of additional runtime pagetable memory.
1112
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001113config TOSHIBA
1114 tristate "Toshiba Laptop support"
1115 depends on X86_32
1116 ---help---
1117 This adds a driver to safely access the System Management Mode of
1118 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1119 not work on models with a Phoenix BIOS. The System Management Mode
1120 is used to set the BIOS and power saving options on Toshiba portables.
1121
1122 For information on utilities to make use of this driver see the
1123 Toshiba Linux utilities web site at:
1124 <http://www.buzzard.org.uk/toshiba/>.
1125
1126 Say Y if you intend to run this kernel on a Toshiba portable.
1127 Say N otherwise.
1128
1129config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001130 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001131 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001132 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001133 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001134 This option enables legacy /proc/i8k userspace interface in hwmon
1135 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1136 temperature and allows controlling fan speeds of Dell laptops via
1137 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1138 it reports also power and hotkey status. For fan speed control is
1139 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001140
Pali Rohár039ae582015-05-14 13:16:37 +02001141 Say Y if you intend to run this kernel on old Dell laptops or want to
1142 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001143 Say N otherwise.
1144
1145config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001146 bool "Enable X86 board specific fixups for reboot"
1147 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001148 ---help---
1149 This enables chipset and/or board specific fixups to be done
1150 in order to get reboot to work correctly. This is only needed on
1151 some combinations of hardware and BIOS. The symptom, for which
1152 this config is intended, is when reboot ends with a stalled/hung
1153 system.
1154
1155 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001156 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001157
1158 Say Y if you want to enable the fixup. Currently, it's safe to
1159 enable this option even if you don't need it.
1160 Say N otherwise.
1161
1162config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001163 bool "CPU microcode loading support"
1164 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001165 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Borislav Petkovfe055892015-10-20 11:54:45 +02001166 depends on BLK_DEV_INITRD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001167 select FW_LOADER
1168 ---help---
Borislav Petkove43f6e62012-08-01 19:17:01 +02001169
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001170 If you say Y here, you will be able to update the microcode on
Peter Oruba80cc9f12008-07-28 18:44:22 +02001171 certain Intel and AMD processors. The Intel support is for the
Borislav Petkove43f6e62012-08-01 19:17:01 +02001172 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1173 Xeon etc. The AMD support is for families 0x10 and later. You will
1174 obviously need the actual microcode binary data itself which is not
1175 shipped with the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001176
Peter Oruba8d86f392008-07-28 18:44:21 +02001177 This option selects the general module only, you need to select
1178 at least one vendor specific module as well.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001179
Borislav Petkove43f6e62012-08-01 19:17:01 +02001180 To compile this driver as a module, choose M here: the module
1181 will be called microcode.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001182
Peter Oruba8d86f392008-07-28 18:44:21 +02001183config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001184 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001185 depends on MICROCODE
1186 default MICROCODE
1187 select FW_LOADER
1188 ---help---
1189 This options enables microcode patch loading support for Intel
1190 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001191
Alanb8989db2014-01-20 18:01:56 +00001192 For the current Intel microcode data package go to
1193 <https://downloadcenter.intel.com> and search for
1194 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001195
Peter Oruba80cc9f12008-07-28 18:44:22 +02001196config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001197 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001198 depends on MICROCODE
1199 select FW_LOADER
1200 ---help---
1201 If you select this option, microcode patch loading support for AMD
1202 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001203
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001204config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001205 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001206 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001207
1208config X86_MSR
1209 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001210 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001211 This device gives privileged processes access to the x86
1212 Model-Specific Registers (MSRs). It is a character device with
1213 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1214 MSR accesses are directed to a specific CPU on multi-processor
1215 systems.
1216
1217config X86_CPUID
1218 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001219 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001220 This device gives processes access to the x86 CPUID instruction to
1221 be executed on a specific processor. It is a character device
1222 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1223 /dev/cpu/31/cpuid.
1224
1225choice
1226 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001227 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001228 depends on X86_32
1229
1230config NOHIGHMEM
1231 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001232 ---help---
1233 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1234 However, the address space of 32-bit x86 processors is only 4
1235 Gigabytes large. That means that, if you have a large amount of
1236 physical memory, not all of it can be "permanently mapped" by the
1237 kernel. The physical memory that's not permanently mapped is called
1238 "high memory".
1239
1240 If you are compiling a kernel which will never run on a machine with
1241 more than 1 Gigabyte total physical RAM, answer "off" here (default
1242 choice and suitable for most users). This will result in a "3GB/1GB"
1243 split: 3GB are mapped so that each process sees a 3GB virtual memory
1244 space and the remaining part of the 4GB virtual memory space is used
1245 by the kernel to permanently map as much physical memory as
1246 possible.
1247
1248 If the machine has between 1 and 4 Gigabytes physical RAM, then
1249 answer "4GB" here.
1250
1251 If more than 4 Gigabytes is used then answer "64GB" here. This
1252 selection turns Intel PAE (Physical Address Extension) mode on.
1253 PAE implements 3-level paging on IA32 processors. PAE is fully
1254 supported by Linux, PAE mode is implemented on all recent Intel
1255 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1256 then the kernel will not boot on CPUs that don't support PAE!
1257
1258 The actual amount of total physical memory will either be
1259 auto detected or can be forced by using a kernel command line option
1260 such as "mem=256M". (Try "man bootparam" or see the documentation of
1261 your boot loader (lilo or loadlin) about how to pass options to the
1262 kernel at boot time.)
1263
1264 If unsure, say "off".
1265
1266config HIGHMEM4G
1267 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001268 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001269 Select this if you have a 32-bit processor and between 1 and 4
1270 gigabytes of physical RAM.
1271
1272config HIGHMEM64G
1273 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001274 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001275 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001276 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001277 Select this if you have a 32-bit processor and more than 4
1278 gigabytes of physical RAM.
1279
1280endchoice
1281
1282choice
David Rientjes6a108a12011-01-20 14:44:16 -08001283 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001284 default VMSPLIT_3G
1285 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001286 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001287 Select the desired split between kernel and user memory.
1288
1289 If the address range available to the kernel is less than the
1290 physical memory installed, the remaining memory will be available
1291 as "high memory". Accessing high memory is a little more costly
1292 than low memory, as it needs to be mapped into the kernel first.
1293 Note that increasing the kernel address space limits the range
1294 available to user programs, making the address space there
1295 tighter. Selecting anything other than the default 3G/1G split
1296 will also likely make your kernel incompatible with binary-only
1297 kernel modules.
1298
1299 If you are not absolutely sure what you are doing, leave this
1300 option alone!
1301
1302 config VMSPLIT_3G
1303 bool "3G/1G user/kernel split"
1304 config VMSPLIT_3G_OPT
1305 depends on !X86_PAE
1306 bool "3G/1G user/kernel split (for full 1G low memory)"
1307 config VMSPLIT_2G
1308 bool "2G/2G user/kernel split"
1309 config VMSPLIT_2G_OPT
1310 depends on !X86_PAE
1311 bool "2G/2G user/kernel split (for full 2G low memory)"
1312 config VMSPLIT_1G
1313 bool "1G/3G user/kernel split"
1314endchoice
1315
1316config PAGE_OFFSET
1317 hex
1318 default 0xB0000000 if VMSPLIT_3G_OPT
1319 default 0x80000000 if VMSPLIT_2G
1320 default 0x78000000 if VMSPLIT_2G_OPT
1321 default 0x40000000 if VMSPLIT_1G
1322 default 0xC0000000
1323 depends on X86_32
1324
1325config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001326 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001327 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001328
1329config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001330 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001331 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001332 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001333 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001334 PAE is required for NX support, and furthermore enables
1335 larger swapspace support for non-overcommit purposes. It
1336 has the cost of more pagetable lookup overhead, and also
1337 consumes more pagetable space per process.
1338
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001339config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001340 def_bool y
1341 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001342
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001343config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001344 def_bool y
1345 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001346
Ingo Molnar10971ab2015-03-05 08:18:23 +01001347config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001348 def_bool y
1349 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001350 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001351 Certain kernel features effectively disable kernel
1352 linear 1 GB mappings (even if the CPU otherwise
1353 supports them), so don't confuse the user by printing
1354 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001355
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001356# Common NUMA Features
1357config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001358 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001359 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001360 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1361 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001362 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001363 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001364
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001365 The kernel will try to allocate memory used by a CPU on the
1366 local memory controller of the CPU and add some more
1367 NUMA awareness to the kernel.
1368
Ingo Molnarc280ea52008-11-08 13:29:45 +01001369 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001370 (or later), AMD Opteron, or EM64T NUMA.
1371
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001372 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001373 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001374
1375 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001376
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001377config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001378 def_bool y
1379 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001380 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001381 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001382 Enable AMD NUMA node topology detection. You should say Y here if
1383 you have a multi processor AMD system. This uses an old method to
1384 read the NUMA configuration directly from the builtin Northbridge
1385 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1386 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001387
1388config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001389 def_bool y
1390 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001391 depends on X86_64 && NUMA && ACPI && PCI
1392 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001393 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001394 Enable ACPI SRAT based node topology detection.
1395
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001396# Some NUMA nodes have memory ranges that span
1397# other nodes. Even though a pfn is valid and
1398# between a node's start and end pfns, it may not
1399# reside on that node. See memmap_init_zone()
1400# for details.
1401config NODES_SPAN_OTHER_NODES
1402 def_bool y
1403 depends on X86_64_ACPI_NUMA
1404
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001405config NUMA_EMU
1406 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001407 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001408 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001409 Enable NUMA emulation. A flat machine will be split
1410 into virtual nodes when booted with "numa=fake=N", where N is the
1411 number of nodes. This is only useful for debugging.
1412
1413config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001414 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001415 range 1 10
1416 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001417 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001418 default "3"
1419 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001420 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001421 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001422 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001423
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001424config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001425 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001426 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001427
1428config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001429 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001430 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001431
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001432config ARCH_FLATMEM_ENABLE
1433 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001434 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001435
1436config ARCH_DISCONTIGMEM_ENABLE
1437 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001438 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001439
1440config ARCH_DISCONTIGMEM_DEFAULT
1441 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001442 depends on NUMA && X86_32
1443
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001444config ARCH_SPARSEMEM_ENABLE
1445 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001446 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001447 select SPARSEMEM_STATIC if X86_32
1448 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1449
Tejun Heo3b166512011-04-01 11:15:12 +02001450config ARCH_SPARSEMEM_DEFAULT
1451 def_bool y
1452 depends on X86_64
1453
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001454config ARCH_SELECT_MEMORY_MODEL
1455 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001456 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001457
1458config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001459 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001460 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001461 help
1462 This option enables a sysfs memory/probe interface for testing.
1463 See Documentation/memory-hotplug.txt for more information.
1464 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001465
Tejun Heo3b166512011-04-01 11:15:12 +02001466config ARCH_PROC_KCORE_TEXT
1467 def_bool y
1468 depends on X86_64 && PROC_KCORE
1469
Avi Kivitya29815a2010-01-10 16:28:09 +02001470config ILLEGAL_POINTER_VALUE
1471 hex
1472 default 0 if X86_32
1473 default 0xdead000000000000 if X86_64
1474
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001475source "mm/Kconfig"
1476
Dan Williams7a678322015-08-19 00:34:34 -04001477config X86_PMEM_LEGACY_DEVICE
1478 bool
1479
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001480config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001481 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001482 depends on PHYS_ADDR_T_64BIT
1483 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001484 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001485 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001486 help
1487 Treat memory marked using the non-standard e820 type of 12 as used
1488 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1489 The kernel will offer these regions to the 'pmem' driver so
1490 they can be used for persistent storage.
1491
1492 Say Y if unsure.
1493
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001494config HIGHPTE
1495 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001496 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001497 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001498 The VM uses one page table entry for each page of physical memory.
1499 For systems with a lot of RAM, this can be wasteful of precious
1500 low memory. Setting this option will put user-space page table
1501 entries in high memory.
1502
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001503config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001504 bool "Check for low memory corruption"
1505 ---help---
1506 Periodically check for memory corruption in low memory, which
1507 is suspected to be caused by BIOS. Even when enabled in the
1508 configuration, it is disabled at runtime. Enable it by
1509 setting "memory_corruption_check=1" on the kernel command
1510 line. By default it scans the low 64k of memory every 60
1511 seconds; see the memory_corruption_check_size and
1512 memory_corruption_check_period parameters in
1513 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001514
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001515 When enabled with the default parameters, this option has
1516 almost no overhead, as it reserves a relatively small amount
1517 of memory and scans it infrequently. It both detects corruption
1518 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001519
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001520 It is, however, intended as a diagnostic tool; if repeatable
1521 BIOS-originated corruption always affects the same memory,
1522 you can use memmap= to prevent the kernel from using that
1523 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001524
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001525config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001526 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001527 depends on X86_CHECK_BIOS_CORRUPTION
1528 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001529 ---help---
1530 Set whether the default state of memory_corruption_check is
1531 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001532
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001533config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001534 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1535 default 64
1536 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001537 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001538 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001539
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001540 The first page contains BIOS data structures that the kernel
1541 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001542
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001543 By default we reserve the first 64K of physical RAM, as a
1544 number of BIOSes are known to corrupt that memory range
1545 during events such as suspend/resume or monitor cable
1546 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001547
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001548 You can set this to 4 if you are absolutely sure that you
1549 trust the BIOS to get all its memory reservations and usages
1550 right. If you know your BIOS have problems beyond the
1551 default 64K area, you can set this to 640 to avoid using the
1552 entire low memory range.
1553
1554 If you have doubts about the BIOS (e.g. suspend/resume does
1555 not work or there's kernel crashes after certain hardware
1556 hotplug events) then you might want to enable
1557 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1558 typical corruption patterns.
1559
1560 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001561
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001562config MATH_EMULATION
1563 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001564 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001565 prompt "Math emulation" if X86_32
1566 ---help---
1567 Linux can emulate a math coprocessor (used for floating point
1568 operations) if you don't have one. 486DX and Pentium processors have
1569 a math coprocessor built in, 486SX and 386 do not, unless you added
1570 a 487DX or 387, respectively. (The messages during boot time can
1571 give you some hints here ["man dmesg"].) Everyone needs either a
1572 coprocessor or this emulation.
1573
1574 If you don't have a math coprocessor, you need to say Y here; if you
1575 say Y here even though you have a coprocessor, the coprocessor will
1576 be used nevertheless. (This behavior can be changed with the kernel
1577 command line option "no387", which comes handy if your coprocessor
1578 is broken. Try "man bootparam" or see the documentation of your boot
1579 loader (lilo or loadlin) about how to pass options to the kernel at
1580 boot time.) This means that it is a good idea to say Y here if you
1581 intend to use this kernel on different machines.
1582
1583 More information about the internals of the Linux math coprocessor
1584 emulation can be found in <file:arch/x86/math-emu/README>.
1585
1586 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1587 kernel, it won't hurt.
1588
1589config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001590 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001591 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001592 ---help---
1593 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1594 the Memory Type Range Registers (MTRRs) may be used to control
1595 processor access to memory ranges. This is most useful if you have
1596 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1597 allows bus write transfers to be combined into a larger transfer
1598 before bursting over the PCI/AGP bus. This can increase performance
1599 of image write operations 2.5 times or more. Saying Y here creates a
1600 /proc/mtrr file which may be used to manipulate your processor's
1601 MTRRs. Typically the X server should use this.
1602
1603 This code has a reasonably generic interface so that similar
1604 control registers on other processors can be easily supported
1605 as well:
1606
1607 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1608 Registers (ARRs) which provide a similar functionality to MTRRs. For
1609 these, the ARRs are used to emulate the MTRRs.
1610 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1611 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1612 write-combining. All of these processors are supported by this code
1613 and it makes sense to say Y here if you have one of them.
1614
1615 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1616 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1617 can lead to all sorts of problems, so it's good to say Y here.
1618
1619 You can safely say Y even if your machine doesn't have MTRRs, you'll
1620 just add about 9 KB to your kernel.
1621
Randy Dunlap7225e752008-07-26 17:54:22 -07001622 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001623
Yinghai Lu95ffa242008-04-29 03:52:33 -07001624config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001625 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001626 prompt "MTRR cleanup support"
1627 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001628 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001629 Convert MTRR layout from continuous to discrete, so X drivers can
1630 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001631
Thomas Gleixneraba37282008-07-15 14:48:48 +02001632 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001633 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001634 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001635
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001636 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001637
1638config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001639 int "MTRR cleanup enable value (0-1)"
1640 range 0 1
1641 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001642 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001643 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001644 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001645
Yinghai Lu12031a62008-05-02 02:40:22 -07001646config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1647 int "MTRR cleanup spare reg num (0-7)"
1648 range 0 7
1649 default "1"
1650 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001651 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001652 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001653 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001654
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001655config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001656 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001657 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001658 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001659 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001660 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001661
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001662 PATs are the modern equivalents of MTRRs and are much more
1663 flexible than MTRRs.
1664
1665 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001666 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001667
1668 If unsure, say Y.
1669
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001670config ARCH_USES_PG_UNCACHED
1671 def_bool y
1672 depends on X86_PAT
1673
H. Peter Anvin628c6242011-07-31 13:59:29 -07001674config ARCH_RANDOM
1675 def_bool y
1676 prompt "x86 architectural random number generator" if EXPERT
1677 ---help---
1678 Enable the x86 architectural RDRAND instruction
1679 (Intel Bull Mountain technology) to generate random numbers.
1680 If supported, this is a high bandwidth, cryptographically
1681 secure hardware random number generator.
1682
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001683config X86_SMAP
1684 def_bool y
1685 prompt "Supervisor Mode Access Prevention" if EXPERT
1686 ---help---
1687 Supervisor Mode Access Prevention (SMAP) is a security
1688 feature in newer Intel processors. There is a small
1689 performance cost if this enabled and turned on; there is
1690 also a small increase in the kernel size if this is enabled.
1691
1692 If unsure, say Y.
1693
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001694config X86_INTEL_MPX
1695 prompt "Intel MPX (Memory Protection Extensions)"
1696 def_bool n
1697 depends on CPU_SUP_INTEL
1698 ---help---
1699 MPX provides hardware features that can be used in
1700 conjunction with compiler-instrumented code to check
1701 memory references. It is designed to detect buffer
1702 overflow or underflow bugs.
1703
1704 This option enables running applications which are
1705 instrumented or otherwise use MPX. It does not use MPX
1706 itself inside the kernel or to protect the kernel
1707 against bad memory references.
1708
1709 Enabling this option will make the kernel larger:
1710 ~8k of kernel text and 36 bytes of data on a 64-bit
1711 defconfig. It adds a long to the 'mm_struct' which
1712 will increase the kernel memory overhead of each
1713 process and adds some branches to paths used during
1714 exec() and munmap().
1715
1716 For details, see Documentation/x86/intel_mpx.txt
1717
1718 If unsure, say N.
1719
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001720config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001721 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001722 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001723 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001724 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001725 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001726 This enables the kernel to use EFI runtime services that are
1727 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001728
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001729 This option is only useful on systems that have EFI firmware.
1730 In addition, you should use the latest ELILO loader available
1731 at <http://elilo.sourceforge.net> in order to take advantage
1732 of EFI runtime services. However, even with this option, the
1733 resultant kernel should continue to boot on existing non-EFI
1734 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001735
Matt Fleming291f3632011-12-12 21:27:52 +00001736config EFI_STUB
1737 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001738 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001739 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001740 ---help---
1741 This kernel feature allows a bzImage to be loaded directly
1742 by EFI firmware without the use of a bootloader.
1743
Roy Franz4172fe22013-09-22 15:45:25 -07001744 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001745
Matt Fleming7d453ee2014-01-10 18:52:06 +00001746config EFI_MIXED
1747 bool "EFI mixed-mode support"
1748 depends on EFI_STUB && X86_64
1749 ---help---
1750 Enabling this feature allows a 64-bit kernel to be booted
1751 on a 32-bit firmware, provided that your CPU supports 64-bit
1752 mode.
1753
1754 Note that it is not possible to boot a mixed-mode enabled
1755 kernel via the EFI boot stub - a bootloader that supports
1756 the EFI handover protocol must be used.
1757
1758 If unsure, say N.
1759
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001760config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001761 def_bool y
1762 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001763 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001764 This kernel feature is useful for number crunching applications
1765 that may need to compute untrusted bytecode during their
1766 execution. By using pipes or other transports made available to
1767 the process as file descriptors supporting the read/write
1768 syscalls, it's possible to isolate those applications in
1769 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001770 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001771 and the task is only allowed to execute a few safe syscalls
1772 defined by each seccomp mode.
1773
1774 If unsure, say Y. Only embedded should say N here.
1775
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001776source kernel/Kconfig.hz
1777
1778config KEXEC
1779 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001780 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001781 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001782 kexec is a system call that implements the ability to shutdown your
1783 current kernel, and to start another kernel. It is like a reboot
1784 but it is independent of the system firmware. And like a reboot
1785 you can start any kernel with it, not just Linux.
1786
1787 The name comes from the similarity to the exec system call.
1788
1789 It is an ongoing process to be certain the hardware in a machine
1790 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001791 initially work for you. As of this writing the exact hardware
1792 interface is strongly in flux, so no good recommendation can be
1793 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001794
Vivek Goyal74ca3172014-08-29 15:18:46 -07001795config KEXEC_FILE
1796 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001797 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001798 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001799 depends on X86_64
1800 depends on CRYPTO=y
1801 depends on CRYPTO_SHA256=y
1802 ---help---
1803 This is new version of kexec system call. This system call is
1804 file based and takes file descriptors as system call argument
1805 for kernel and initramfs as opposed to list of segments as
1806 accepted by previous system call.
1807
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001808config KEXEC_VERIFY_SIG
1809 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001810 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001811 ---help---
1812 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001813 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001814
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001815 In addition to that option, you need to enable signature
1816 verification for the corresponding kernel image type being
1817 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001818
1819config KEXEC_BZIMAGE_VERIFY_SIG
1820 bool "Enable bzImage signature verification support"
1821 depends on KEXEC_VERIFY_SIG
1822 depends on SIGNED_PE_FILE_VERIFICATION
1823 select SYSTEM_TRUSTED_KEYRING
1824 ---help---
1825 Enable bzImage signature verification support.
1826
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001827config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001828 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001829 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001830 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001831 Generate crash dump after being started by kexec.
1832 This should be normally only set in special crash dump kernels
1833 which are loaded in the main kernel with kexec-tools into
1834 a specially reserved region and then later executed after
1835 a crash by kdump/kexec. The crash dump kernel must be compiled
1836 to a memory address not used by the main kernel or BIOS using
1837 PHYSICAL_START, or it must be built as a relocatable image
1838 (CONFIG_RELOCATABLE=y).
1839 For more details see Documentation/kdump/kdump.txt
1840
Huang Ying3ab83522008-07-25 19:45:07 -07001841config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001842 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001843 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001844 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001845 Jump between original kernel and kexeced kernel and invoke
1846 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001847
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001848config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001849 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001850 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001851 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001852 This gives the physical address where the kernel is loaded.
1853
1854 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1855 bzImage will decompress itself to above physical address and
1856 run from there. Otherwise, bzImage will run from the address where
1857 it has been loaded by the boot loader and will ignore above physical
1858 address.
1859
1860 In normal kdump cases one does not have to set/change this option
1861 as now bzImage can be compiled as a completely relocatable image
1862 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1863 address. This option is mainly useful for the folks who don't want
1864 to use a bzImage for capturing the crash dump and want to use a
1865 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1866 to be specifically compiled to run from a specific memory area
1867 (normally a reserved region) and this option comes handy.
1868
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001869 So if you are using bzImage for capturing the crash dump,
1870 leave the value here unchanged to 0x1000000 and set
1871 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1872 for capturing the crash dump change this value to start of
1873 the reserved region. In other words, it can be set based on
1874 the "X" value as specified in the "crashkernel=YM@XM"
1875 command line boot parameter passed to the panic-ed
1876 kernel. Please take a look at Documentation/kdump/kdump.txt
1877 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001878
1879 Usage of bzImage for capturing the crash dump is recommended as
1880 one does not have to build two kernels. Same kernel can be used
1881 as production kernel and capture kernel. Above option should have
1882 gone away after relocatable bzImage support is introduced. But it
1883 is present because there are users out there who continue to use
1884 vmlinux for dump capture. This option should go away down the
1885 line.
1886
1887 Don't change this unless you know what you are doing.
1888
1889config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001890 bool "Build a relocatable kernel"
1891 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001892 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001893 This builds a kernel image that retains relocation information
1894 so it can be loaded someplace besides the default 1MB.
1895 The relocations tend to make the kernel binary about 10% larger,
1896 but are discarded at runtime.
1897
1898 One use is for the kexec on panic case where the recovery kernel
1899 must live at a different physical address than the primary
1900 kernel.
1901
1902 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1903 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001904 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001905
Kees Cook8ab38202013-10-10 17:18:14 -07001906config RANDOMIZE_BASE
1907 bool "Randomize the address of the kernel image"
1908 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001909 default n
1910 ---help---
1911 Randomizes the physical and virtual address at which the
1912 kernel image is decompressed, as a security feature that
1913 deters exploit attempts relying on knowledge of the location
1914 of kernel internals.
1915
Kees Cooka653f352013-11-11 14:28:39 -08001916 Entropy is generated using the RDRAND instruction if it is
1917 supported. If RDTSC is supported, it is used as well. If
1918 neither RDRAND nor RDTSC are supported, then randomness is
1919 read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001920
1921 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
Kees Cooka653f352013-11-11 14:28:39 -08001922 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1923 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1924 minimum of 2MiB, only 10 bits of entropy is theoretically
1925 possible. At best, due to page table layouts, 64-bit can use
1926 9 bits of entropy and 32-bit uses 8 bits.
Kees Cook8ab38202013-10-10 17:18:14 -07001927
Kees Cookda2b6fb2013-12-10 12:27:45 -08001928 If unsure, say N.
1929
Kees Cook8ab38202013-10-10 17:18:14 -07001930config RANDOMIZE_BASE_MAX_OFFSET
Kees Cookda2b6fb2013-12-10 12:27:45 -08001931 hex "Maximum kASLR offset allowed" if EXPERT
Kees Cook8ab38202013-10-10 17:18:14 -07001932 depends on RANDOMIZE_BASE
Kees Cook6145cfe2013-10-10 17:18:18 -07001933 range 0x0 0x20000000 if X86_32
1934 default "0x20000000" if X86_32
1935 range 0x0 0x40000000 if X86_64
1936 default "0x40000000" if X86_64
Kees Cook8ab38202013-10-10 17:18:14 -07001937 ---help---
Kees Cookda2b6fb2013-12-10 12:27:45 -08001938 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1939 memory is used to determine the maximal offset in bytes that will
1940 be applied to the kernel when kernel Address Space Layout
1941 Randomization (kASLR) is active. This must be a multiple of
1942 PHYSICAL_ALIGN.
Kees Cook6145cfe2013-10-10 17:18:18 -07001943
Kees Cookda2b6fb2013-12-10 12:27:45 -08001944 On 32-bit this is limited to 512MiB by page table layouts. The
1945 default is 512MiB.
Kees Cook6145cfe2013-10-10 17:18:18 -07001946
Kees Cookda2b6fb2013-12-10 12:27:45 -08001947 On 64-bit this is limited by how the kernel fixmap page table is
1948 positioned, so this cannot be larger than 1GiB currently. Without
1949 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1950 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1951 modules area will shrink to compensate, up to the current maximum
1952 1GiB to 1GiB split. The default is 1GiB.
1953
1954 If unsure, leave at the default value.
Kees Cook8ab38202013-10-10 17:18:14 -07001955
1956# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001957config X86_NEED_RELOCS
1958 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001959 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001960
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001961config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001962 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001963 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001964 range 0x2000 0x1000000 if X86_32
1965 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001966 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001967 This value puts the alignment restrictions on physical address
1968 where kernel is loaded and run from. Kernel is compiled for an
1969 address which meets above alignment restriction.
1970
1971 If bootloader loads the kernel at a non-aligned address and
1972 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1973 address aligned to above value and run from there.
1974
1975 If bootloader loads the kernel at a non-aligned address and
1976 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1977 load address and decompress itself to the address it has been
1978 compiled for and run from there. The address for which kernel is
1979 compiled already meets above alignment restrictions. Hence the
1980 end result is that kernel runs from a physical address meeting
1981 above alignment restrictions.
1982
Kees Cooka0215062013-07-08 09:15:17 -07001983 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1984 this value must be a multiple of 0x200000.
1985
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001986 Don't change this unless you know what you are doing.
1987
1988config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001989 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001990 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001991 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001992 Say Y here to allow turning CPUs off and on. CPUs can be
1993 controlled through /sys/devices/system/cpu.
1994 ( Note: power management support will enable this option
1995 automatically on SMP systems. )
1996 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001997
Fenghua Yu80aa1df2012-11-13 11:32:39 -08001998config BOOTPARAM_HOTPLUG_CPU0
1999 bool "Set default setting of cpu0_hotpluggable"
2000 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002001 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002002 ---help---
2003 Set whether default state of cpu0_hotpluggable is on or off.
2004
2005 Say Y here to enable CPU0 hotplug by default. If this switch
2006 is turned on, there is no need to give cpu0_hotplug kernel
2007 parameter and the CPU0 hotplug feature is enabled by default.
2008
2009 Please note: there are two known CPU0 dependencies if you want
2010 to enable the CPU0 hotplug feature either by this switch or by
2011 cpu0_hotplug kernel parameter.
2012
2013 First, resume from hibernate or suspend always starts from CPU0.
2014 So hibernate and suspend are prevented if CPU0 is offline.
2015
2016 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2017 offline if any interrupt can not migrate out of CPU0. There may
2018 be other CPU0 dependencies.
2019
2020 Please make sure the dependencies are under your control before
2021 you enable this feature.
2022
2023 Say N if you don't want to enable CPU0 hotplug feature by default.
2024 You still can enable the CPU0 hotplug feature at boot by kernel
2025 parameter cpu0_hotplug.
2026
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002027config DEBUG_HOTPLUG_CPU0
2028 def_bool n
2029 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002030 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002031 ---help---
2032 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2033 soon as possible and boots up userspace with CPU0 offlined. User
2034 can online CPU0 back after boot time.
2035
2036 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2037 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2038 compilation or giving cpu0_hotplug kernel parameter at boot.
2039
2040 If unsure, say N.
2041
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002042config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002043 def_bool n
2044 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002045 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002046 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002047 Certain buggy versions of glibc will crash if they are
2048 presented with a 32-bit vDSO that is not mapped at the address
2049 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002050
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002051 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2052 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2053 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2054 the only released version with the bug, but OpenSUSE 9
2055 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002056
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002057 The symptom of the bug is that everything crashes on startup, saying:
2058 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2059
2060 Saying Y here changes the default value of the vdso32 boot
2061 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2062 This works around the glibc bug but hurts performance.
2063
2064 If unsure, say N: if you are compiling your own kernel, you
2065 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002066
Kees Cook3dc33bd2015-08-12 17:55:19 -07002067choice
2068 prompt "vsyscall table for legacy applications"
2069 depends on X86_64
2070 default LEGACY_VSYSCALL_EMULATE
2071 help
2072 Legacy user code that does not know how to find the vDSO expects
2073 to be able to issue three syscalls by calling fixed addresses in
2074 kernel space. Since this location is not randomized with ASLR,
2075 it can be used to assist security vulnerability exploitation.
2076
2077 This setting can be changed at boot time via the kernel command
2078 line parameter vsyscall=[native|emulate|none].
2079
2080 On a system with recent enough glibc (2.14 or newer) and no
2081 static binaries, you can say None without a performance penalty
2082 to improve security.
2083
2084 If unsure, select "Emulate".
2085
2086 config LEGACY_VSYSCALL_NATIVE
2087 bool "Native"
2088 help
2089 Actual executable code is located in the fixed vsyscall
2090 address mapping, implementing time() efficiently. Since
2091 this makes the mapping executable, it can be used during
2092 security vulnerability exploitation (traditionally as
2093 ROP gadgets). This configuration is not recommended.
2094
2095 config LEGACY_VSYSCALL_EMULATE
2096 bool "Emulate"
2097 help
2098 The kernel traps and emulates calls into the fixed
2099 vsyscall address mapping. This makes the mapping
2100 non-executable, but it still contains known contents,
2101 which could be used in certain rare security vulnerability
2102 exploits. This configuration is recommended when userspace
2103 still uses the vsyscall area.
2104
2105 config LEGACY_VSYSCALL_NONE
2106 bool "None"
2107 help
2108 There will be no vsyscall mapping at all. This will
2109 eliminate any risk of ASLR bypass due to the vsyscall
2110 fixed address mapping. Attempts to use the vsyscalls
2111 will be reported to dmesg, so that either old or
2112 malicious userspace programs can be identified.
2113
2114endchoice
2115
Tim Bird516cbf32008-08-12 12:52:36 -07002116config CMDLINE_BOOL
2117 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002118 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002119 Allow for specifying boot arguments to the kernel at
2120 build time. On some systems (e.g. embedded ones), it is
2121 necessary or convenient to provide some or all of the
2122 kernel boot arguments with the kernel itself (that is,
2123 to not rely on the boot loader to provide them.)
2124
2125 To compile command line arguments into the kernel,
2126 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002127 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002128
2129 Systems with fully functional boot loaders (i.e. non-embedded)
2130 should leave this option set to 'N'.
2131
2132config CMDLINE
2133 string "Built-in kernel command string"
2134 depends on CMDLINE_BOOL
2135 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002136 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002137 Enter arguments here that should be compiled into the kernel
2138 image and used at boot time. If the boot loader provides a
2139 command line at boot time, it is appended to this string to
2140 form the full kernel command line, when the system boots.
2141
2142 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2143 change this behavior.
2144
2145 In most cases, the command line (whether built-in or provided
2146 by the boot loader) should specify the device for the root
2147 file system.
2148
2149config CMDLINE_OVERRIDE
2150 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002151 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002152 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002153 Set this option to 'Y' to have the kernel ignore the boot loader
2154 command line, and use ONLY the built-in command line.
2155
2156 This is used to work around broken boot loaders. This should
2157 be set to 'N' under normal conditions.
2158
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002159config MODIFY_LDT_SYSCALL
2160 bool "Enable the LDT (local descriptor table)" if EXPERT
2161 default y
2162 ---help---
2163 Linux can allow user programs to install a per-process x86
2164 Local Descriptor Table (LDT) using the modify_ldt(2) system
2165 call. This is required to run 16-bit or segmented code such as
2166 DOSEMU or some Wine programs. It is also used by some very old
2167 threading libraries.
2168
2169 Enabling this feature adds a small amount of overhead to
2170 context switches and increases the low-level kernel attack
2171 surface. Disabling it removes the modify_ldt(2) system call.
2172
2173 Saying 'N' here may make sense for embedded or server kernels.
2174
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002175source "kernel/livepatch/Kconfig"
2176
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002177endmenu
2178
2179config ARCH_ENABLE_MEMORY_HOTPLUG
2180 def_bool y
2181 depends on X86_64 || (X86_32 && HIGHMEM)
2182
Gary Hade35551052008-10-31 10:52:03 -07002183config ARCH_ENABLE_MEMORY_HOTREMOVE
2184 def_bool y
2185 depends on MEMORY_HOTPLUG
2186
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002187config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002188 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002189 depends on NUMA
2190
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002191config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2192 def_bool y
2193 depends on X86_64 || X86_PAE
2194
Naoya Horiguchic177c812014-06-04 16:05:35 -07002195config ARCH_ENABLE_HUGEPAGE_MIGRATION
2196 def_bool y
2197 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2198
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002199menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002200
2201config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002202 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002203 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002204
2205source "kernel/power/Kconfig"
2206
2207source "drivers/acpi/Kconfig"
2208
Feng Tangefafc8b2009-08-14 15:23:29 -04002209source "drivers/sfi/Kconfig"
2210
Andi Kleena6b68072008-01-30 13:32:49 +01002211config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002212 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002213 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002214
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002215menuconfig APM
2216 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002217 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002218 ---help---
2219 APM is a BIOS specification for saving power using several different
2220 techniques. This is mostly useful for battery powered laptops with
2221 APM compliant BIOSes. If you say Y here, the system time will be
2222 reset after a RESUME operation, the /proc/apm device will provide
2223 battery status information, and user-space programs will receive
2224 notification of APM "events" (e.g. battery status change).
2225
2226 If you select "Y" here, you can disable actual use of the APM
2227 BIOS by passing the "apm=off" option to the kernel at boot time.
2228
2229 Note that the APM support is almost completely disabled for
2230 machines with more than one CPU.
2231
2232 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002233 and more information, read <file:Documentation/power/apm-acpi.txt>
2234 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002235 <http://www.tldp.org/docs.html#howto>.
2236
2237 This driver does not spin down disk drives (see the hdparm(8)
2238 manpage ("man 8 hdparm") for that), and it doesn't turn off
2239 VESA-compliant "green" monitors.
2240
2241 This driver does not support the TI 4000M TravelMate and the ACER
2242 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2243 desktop machines also don't have compliant BIOSes, and this driver
2244 may cause those machines to panic during the boot phase.
2245
2246 Generally, if you don't have a battery in your machine, there isn't
2247 much point in using this driver and you should say N. If you get
2248 random kernel OOPSes or reboots that don't seem to be related to
2249 anything, try disabling/enabling this option (or disabling/enabling
2250 APM in your BIOS).
2251
2252 Some other things you should try when experiencing seemingly random,
2253 "weird" problems:
2254
2255 1) make sure that you have enough swap space and that it is
2256 enabled.
2257 2) pass the "no-hlt" option to the kernel
2258 3) switch on floating point emulation in the kernel and pass
2259 the "no387" option to the kernel
2260 4) pass the "floppy=nodma" option to the kernel
2261 5) pass the "mem=4M" option to the kernel (thereby disabling
2262 all but the first 4 MB of RAM)
2263 6) make sure that the CPU is not over clocked.
2264 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2265 8) disable the cache from your BIOS settings
2266 9) install a fan for the video card or exchange video RAM
2267 10) install a better fan for the CPU
2268 11) exchange RAM chips
2269 12) exchange the motherboard.
2270
2271 To compile this driver as a module, choose M here: the
2272 module will be called apm.
2273
2274if APM
2275
2276config APM_IGNORE_USER_SUSPEND
2277 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002278 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002279 This option will ignore USER SUSPEND requests. On machines with a
2280 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2281 series notebooks, it is necessary to say Y because of a BIOS bug.
2282
2283config APM_DO_ENABLE
2284 bool "Enable PM at boot time"
2285 ---help---
2286 Enable APM features at boot time. From page 36 of the APM BIOS
2287 specification: "When disabled, the APM BIOS does not automatically
2288 power manage devices, enter the Standby State, enter the Suspend
2289 State, or take power saving steps in response to CPU Idle calls."
2290 This driver will make CPU Idle calls when Linux is idle (unless this
2291 feature is turned off -- see "Do CPU IDLE calls", below). This
2292 should always save battery power, but more complicated APM features
2293 will be dependent on your BIOS implementation. You may need to turn
2294 this option off if your computer hangs at boot time when using APM
2295 support, or if it beeps continuously instead of suspending. Turn
2296 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2297 T400CDT. This is off by default since most machines do fine without
2298 this feature.
2299
2300config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002301 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002302 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002303 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002304 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2305 On some machines, this can activate improved power savings, such as
2306 a slowed CPU clock rate, when the machine is idle. These idle calls
2307 are made after the idle loop has run for some length of time (e.g.,
2308 333 mS). On some machines, this will cause a hang at boot time or
2309 whenever the CPU becomes idle. (On machines with more than one CPU,
2310 this option does nothing.)
2311
2312config APM_DISPLAY_BLANK
2313 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002314 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002315 Enable console blanking using the APM. Some laptops can use this to
2316 turn off the LCD backlight when the screen blanker of the Linux
2317 virtual console blanks the screen. Note that this is only used by
2318 the virtual console screen blanker, and won't turn off the backlight
2319 when using the X Window system. This also doesn't have anything to
2320 do with your VESA-compliant power-saving monitor. Further, this
2321 option doesn't work for all laptops -- it might not turn off your
2322 backlight at all, or it might print a lot of errors to the console,
2323 especially if you are using gpm.
2324
2325config APM_ALLOW_INTS
2326 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002327 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002328 Normally we disable external interrupts while we are making calls to
2329 the APM BIOS as a measure to lessen the effects of a badly behaving
2330 BIOS implementation. The BIOS should reenable interrupts if it
2331 needs to. Unfortunately, some BIOSes do not -- especially those in
2332 many of the newer IBM Thinkpads. If you experience hangs when you
2333 suspend, try setting this to Y. Otherwise, say N.
2334
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002335endif # APM
2336
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002337source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002338
2339source "drivers/cpuidle/Kconfig"
2340
Andy Henroid27471fd2008-10-09 11:45:22 -07002341source "drivers/idle/Kconfig"
2342
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002343endmenu
2344
2345
2346menu "Bus options (PCI etc.)"
2347
2348config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002349 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002350 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002351 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002352 Find out whether you have a PCI motherboard. PCI is the name of a
2353 bus system, i.e. the way the CPU talks to the other stuff inside
2354 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2355 VESA. If you have PCI, say Y, otherwise N.
2356
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002357choice
2358 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002359 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002360 default PCI_GOANY
2361 ---help---
2362 On PCI systems, the BIOS can be used to detect the PCI devices and
2363 determine their configuration. However, some old PCI motherboards
2364 have BIOS bugs and may crash if this is done. Also, some embedded
2365 PCI-based systems don't have any BIOS at all. Linux can also try to
2366 detect the PCI hardware directly without using the BIOS.
2367
2368 With this option, you can specify how Linux should detect the
2369 PCI devices. If you choose "BIOS", the BIOS will be used,
2370 if you choose "Direct", the BIOS won't be used, and if you
2371 choose "MMConfig", then PCI Express MMCONFIG will be used.
2372 If you choose "Any", the kernel will try MMCONFIG, then the
2373 direct access method and falls back to the BIOS if that doesn't
2374 work. If unsure, go with the default, which is "Any".
2375
2376config PCI_GOBIOS
2377 bool "BIOS"
2378
2379config PCI_GOMMCONFIG
2380 bool "MMConfig"
2381
2382config PCI_GODIRECT
2383 bool "Direct"
2384
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002385config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002386 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002387 depends on OLPC
2388
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002389config PCI_GOANY
2390 bool "Any"
2391
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002392endchoice
2393
2394config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002395 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002396 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002397
2398# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2399config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002400 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002401 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002402
2403config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002404 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002405 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002406
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002407config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002408 def_bool y
2409 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002410
Alex Nixonb5401a92010-03-18 16:31:34 -04002411config PCI_XEN
2412 def_bool y
2413 depends on PCI && XEN
2414 select SWIOTLB_XEN
2415
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002416config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002417 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002418 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002419
2420config PCI_MMCONFIG
2421 bool "Support mmconfig PCI config space access"
2422 depends on X86_64 && PCI && ACPI
2423
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002424config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002425 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002426 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002427 help
2428 Read the PCI windows out of the CNB20LE host bridge. This allows
2429 PCI hotplug to work on systems with the CNB20LE chipset which do
2430 not have ACPI.
2431
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002432 There's no public spec for this chipset, and this functionality
2433 is known to be incomplete.
2434
2435 You should say N unless you know you need this.
2436
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002437source "drivers/pci/pcie/Kconfig"
2438
2439source "drivers/pci/Kconfig"
2440
David Rientjes1c00f012011-03-22 16:34:59 -07002441# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002442config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002443 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2444 default y
2445 help
2446 Enables ISA-style DMA support for devices requiring such controllers.
2447 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002448
2449if X86_32
2450
2451config ISA
2452 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002453 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002454 Find out whether you have ISA slots on your motherboard. ISA is the
2455 name of a bus system, i.e. the way the CPU talks to the other stuff
2456 inside your box. Other bus systems are PCI, EISA, MicroChannel
2457 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2458 newer boards don't support it. If you have ISA, say Y, otherwise N.
2459
2460config EISA
2461 bool "EISA support"
2462 depends on ISA
2463 ---help---
2464 The Extended Industry Standard Architecture (EISA) bus was
2465 developed as an open alternative to the IBM MicroChannel bus.
2466
2467 The EISA bus provided some of the features of the IBM MicroChannel
2468 bus while maintaining backward compatibility with cards made for
2469 the older ISA bus. The EISA bus saw limited use between 1988 and
2470 1995 when it was made obsolete by the PCI bus.
2471
2472 Say Y here if you are building a kernel for an EISA-based machine.
2473
2474 Otherwise, say N.
2475
2476source "drivers/eisa/Kconfig"
2477
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002478config SCx200
2479 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002480 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002481 This provides basic support for National Semiconductor's
2482 (now AMD's) Geode processors. The driver probes for the
2483 PCI-IDs of several on-chip devices, so its a good dependency
2484 for other scx200_* drivers.
2485
2486 If compiled as a module, the driver is named scx200.
2487
2488config SCx200HR_TIMER
2489 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002490 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002491 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002492 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 This driver provides a clocksource built upon the on-chip
2494 27MHz high-resolution timer. Its also a workaround for
2495 NSC Geode SC-1100's buggy TSC, which loses time when the
2496 processor goes idle (as is done by the scheduler). The
2497 other workaround is idle=poll boot option.
2498
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002499config OLPC
2500 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002501 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002502 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002503 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002504 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002505 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002506 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002507 Add support for detecting the unique features of the OLPC
2508 XO hardware.
2509
Daniel Drakea3128582011-06-25 17:34:10 +01002510config OLPC_XO1_PM
2511 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002512 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002513 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002514 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002515 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002516
Daniel Drakecfee9592011-06-25 17:34:17 +01002517config OLPC_XO1_RTC
2518 bool "OLPC XO-1 Real Time Clock"
2519 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2520 ---help---
2521 Add support for the XO-1 real time clock, which can be used as a
2522 programmable wakeup source.
2523
Daniel Drake7feda8e2011-06-25 17:34:12 +01002524config OLPC_XO1_SCI
2525 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002526 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002527 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002528 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002529 select GPIO_CS5535
2530 select MFD_CORE
2531 ---help---
2532 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002533 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002534 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002535 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002536 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002537 - AC adapter status updates
2538 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002539
Daniel Drakea0f30f52011-06-25 17:34:18 +01002540config OLPC_XO15_SCI
2541 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002542 depends on OLPC && ACPI
2543 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002544 ---help---
2545 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2546 - EC-driven system wakeups
2547 - AC adapter status updates
2548 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002549
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002550config ALIX
2551 bool "PCEngines ALIX System Support (LED setup)"
2552 select GPIOLIB
2553 ---help---
2554 This option enables system support for the PCEngines ALIX.
2555 At present this just sets up LEDs for GPIO control on
2556 ALIX2/3/6 boards. However, other system specific setup should
2557 get added here.
2558
2559 Note: You must still enable the drivers for GPIO and LED support
2560 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2561
2562 Note: You have to set alix.force=1 for boards with Award BIOS.
2563
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002564config NET5501
2565 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2566 select GPIOLIB
2567 ---help---
2568 This option enables system support for the Soekris Engineering net5501.
2569
Philip A. Prindeville31970592012-01-14 01:45:39 -07002570config GEOS
2571 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2572 select GPIOLIB
2573 depends on DMI
2574 ---help---
2575 This option enables system support for the Traverse Technologies GEOS.
2576
Vivien Didelot7d029122013-01-04 16:18:14 -05002577config TS5500
2578 bool "Technologic Systems TS-5500 platform support"
2579 depends on MELAN
2580 select CHECK_SIGNATURE
2581 select NEW_LEDS
2582 select LEDS_CLASS
2583 ---help---
2584 This option enables system support for the Technologic Systems TS-5500.
2585
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002586endif # X86_32
2587
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002588config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002589 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002590 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591
2592source "drivers/pcmcia/Kconfig"
2593
2594source "drivers/pci/hotplug/Kconfig"
2595
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002596config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002597 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002598 depends on PCI
2599 default n
2600 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002601 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002602 infrastructure code to support RapidIO interconnect devices.
2603
2604source "drivers/rapidio/Kconfig"
2605
David Herrmanne3263ab2013-08-02 14:05:22 +02002606config X86_SYSFB
2607 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2608 help
2609 Firmwares often provide initial graphics framebuffers so the BIOS,
2610 bootloader or kernel can show basic video-output during boot for
2611 user-guidance and debugging. Historically, x86 used the VESA BIOS
2612 Extensions and EFI-framebuffers for this, which are mostly limited
2613 to x86.
2614 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2615 framebuffers so the new generic system-framebuffer drivers can be
2616 used on x86. If the framebuffer is not compatible with the generic
2617 modes, it is adverticed as fallback platform framebuffer so legacy
2618 drivers like efifb, vesafb and uvesafb can pick it up.
2619 If this option is not selected, all system framebuffers are always
2620 marked as fallback platform framebuffers as usual.
2621
2622 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2623 not be able to pick up generic system framebuffers if this option
2624 is selected. You are highly encouraged to enable simplefb as
2625 replacement if you select this option. simplefb can correctly deal
2626 with generic system framebuffers. But you should still keep vesafb
2627 and others enabled as fallback if a system framebuffer is
2628 incompatible with simplefb.
2629
2630 If unsure, say Y.
2631
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002632endmenu
2633
2634
2635menu "Executable file formats / Emulations"
2636
2637source "fs/Kconfig.binfmt"
2638
2639config IA32_EMULATION
2640 bool "IA32 Emulation"
2641 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002642 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002643 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002644 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002645 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002646 Include code to run legacy 32-bit programs under a
2647 64-bit kernel. You should likely turn this on, unless you're
2648 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002649
2650config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002651 tristate "IA32 a.out support"
2652 depends on IA32_EMULATION
2653 ---help---
2654 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002655
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002656config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002657 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002658 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002659 ---help---
2660 Include code to run binaries for the x32 native 32-bit ABI
2661 for 64-bit processors. An x32 process gets access to the
2662 full 64-bit register file and wide data path while leaving
2663 pointers at 32 bits for smaller memory footprint.
2664
2665 You will need a recent binutils (2.22 or later) with
2666 elf32_x86_64 support enabled to compile a kernel with this
2667 option set.
2668
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002669config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002670 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002671 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002672
Jan Beulich3120e252012-09-10 12:41:45 +01002673if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002674config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002675 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002676
2677config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002678 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002679 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680
David Howellsee009e4a02011-03-07 15:06:20 +00002681config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002682 def_bool y
2683 depends on KEYS
2684endif
David Howellsee009e4a02011-03-07 15:06:20 +00002685
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002686endmenu
2687
2688
Keith Packarde5beae12008-11-03 18:21:45 +01002689config HAVE_ATOMIC_IOMAP
2690 def_bool y
2691 depends on X86_32
2692
Alessandro Rubini4692d772012-04-04 19:39:58 +02002693config X86_DEV_DMA_OPS
2694 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002695 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002696
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002697config X86_DMA_REMAP
2698 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002699 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002700
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002701config PMC_ATOM
2702 def_bool y
2703 depends on PCI
2704
Keith Busch185a3832016-01-12 13:18:10 -07002705config VMD
2706 depends on PCI_MSI
2707 tristate "Volume Management Device Driver"
2708 default N
2709 ---help---
2710 Adds support for the Intel Volume Management Device (VMD). VMD is a
2711 secondary PCI host bridge that allows PCI Express root ports,
2712 and devices attached to them, to be removed from the default
2713 PCI domain and placed within the VMD domain. This provides
2714 more bus resources than are otherwise possible with a
2715 single domain. If you know your system provides one of these and
2716 has devices attached to it, say Y; if you are not sure, say N.
2717
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002718source "net/Kconfig"
2719
2720source "drivers/Kconfig"
2721
2722source "drivers/firmware/Kconfig"
2723
2724source "fs/Kconfig"
2725
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726source "arch/x86/Kconfig.debug"
2727
2728source "security/Kconfig"
2729
2730source "crypto/Kconfig"
2731
Avi Kivityedf88412007-12-16 11:02:48 +02002732source "arch/x86/kvm/Kconfig"
2733
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002734source "lib/Kconfig"