blob: fb2ebeb9a6925ff5a2bf0e2395602f0ff0f8dc35 [file] [log] [blame]
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
Dave Hansen63c17fb2016-02-12 13:02:08 -0800158 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530159
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200160config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100161 def_bool y
162 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200163
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200164config PERF_EVENTS_INTEL_UNCORE
165 def_bool y
Peter Zijlstra (Intel)ce5686d2014-10-29 11:17:04 +0100166 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200167
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700168config OUTPUT_FORMAT
169 string
170 default "elf32-i386" if X86_32
171 default "elf64-x86-64" if X86_64
172
Sam Ravnborg73531902008-05-25 23:03:18 +0200173config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200174 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200175 default "arch/x86/configs/i386_defconfig" if X86_32
176 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200177
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100178config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100179 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100180
181config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100182 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100183
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100184config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100185 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100186
Daniel Cashman9e08f572016-01-14 15:20:06 -0800187config ARCH_MMAP_RND_BITS_MIN
188 default 28 if 64BIT
189 default 8
190
191config ARCH_MMAP_RND_BITS_MAX
192 default 32 if 64BIT
193 default 16
194
195config ARCH_MMAP_RND_COMPAT_BITS_MIN
196 default 8
197
198config ARCH_MMAP_RND_COMPAT_BITS_MAX
199 default 16
200
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100201config SBUS
202 bool
203
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800204config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100205 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400206 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800207
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700208config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700209 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700210
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100211config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100212 def_bool y
213 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100214
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100215config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100216 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100217 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000218 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
219
220config GENERIC_BUG_RELATIVE_POINTERS
221 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100222
223config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100224 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100225
226config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100227 def_bool y
228 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100229
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100230config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100231 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100232
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100233config GENERIC_CALIBRATE_DELAY
234 def_bool y
235
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800236config ARCH_HAS_CPU_RELAX
237 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100238
Pekka Enberg1b27d052008-04-28 02:12:22 -0700239config ARCH_HAS_CACHE_LINE_SIZE
240 def_bool y
241
Mike Travisdd5af902008-01-30 13:33:32 +0100242config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900243 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100244
Tejun Heo08fc4582009-08-14 15:00:49 +0900245config NEED_PER_CPU_EMBED_FIRST_CHUNK
246 def_bool y
247
248config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900249 def_bool y
250
Johannes Berg801e4062007-12-08 02:12:39 +0100251config ARCH_HIBERNATION_POSSIBLE
252 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100253
Johannes Bergf4cb5702007-12-08 02:14:00 +0100254config ARCH_SUSPEND_POSSIBLE
255 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100256
Steve Cappercfe28c52013-04-29 14:29:48 +0100257config ARCH_WANT_HUGE_PMD_SHARE
258 def_bool y
259
Steve Capper53313b22013-04-30 08:03:42 +0100260config ARCH_WANT_GENERAL_HUGETLB
261 def_bool y
262
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100263config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000264 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100265
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100266config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000267 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100268
Ingo Molnar765c68b2008-04-09 11:03:37 +0200269config ARCH_SUPPORTS_OPTIMIZED_INLINING
270 def_bool y
271
Akinobu Mita6a11f752009-03-31 15:23:17 -0700272config ARCH_SUPPORTS_DEBUG_PAGEALLOC
273 def_bool y
274
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300275config KASAN_SHADOW_OFFSET
276 hex
277 depends on KASAN
278 default 0xdffffc0000000000
279
Shane Wang69575d32009-09-01 18:25:07 -0700280config HAVE_INTEL_TXT
281 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700282 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700283
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100284config X86_32_SMP
285 def_bool y
286 depends on X86_32 && SMP
287
288config X86_64_SMP
289 def_bool y
290 depends on X86_64 && SMP
291
Tejun Heoccbeed32009-02-09 22:17:40 +0900292config X86_32_LAZY_GS
293 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900294 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900295
Borislav Petkovd61931d2010-03-05 17:34:46 +0100296config ARCH_HWEIGHT_CFLAGS
297 string
298 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
299 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
300
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530301config ARCH_SUPPORTS_UPROBES
302 def_bool y
303
Rob Herringd20642f2014-04-18 17:19:54 -0500304config FIX_EARLYCON_MEM
305 def_bool y
306
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700307config PGTABLE_LEVELS
308 int
309 default 4 if X86_64
310 default 3 if X86_PAE
311 default 2
312
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100313source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700314source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100315
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100316menu "Processor type and features"
317
Randy Dunlap5ee71532012-01-16 11:57:18 -0800318config ZONE_DMA
319 bool "DMA memory allocation support" if EXPERT
320 default y
321 help
322 DMA memory allocation support allows devices with less than 32-bit
323 addressing to allocate within the first 16MB of address space.
324 Disable if no such devices will be used.
325
326 If unsure, say Y.
327
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100328config SMP
329 bool "Symmetric multi-processing support"
330 ---help---
331 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800332 a system with only one CPU, say N. If you have a system with more
333 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100334
Robert Graffham4a474152014-01-23 15:55:29 -0800335 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100336 machines, but will use only one CPU of a multiprocessor machine. If
337 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800338 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100339 will run faster if you say N here.
340
341 Note that if you say Y here and choose architecture "586" or
342 "Pentium" under "Processor family", the kernel will not work on 486
343 architectures. Similarly, multiprocessor kernels for the "PPro"
344 architecture may not work on all Pentium based boards.
345
346 People using multiprocessor machines who say Y here should also say
347 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
348 Management" code will be disabled if you say Y here.
349
Paul Bolle395cf962011-08-15 02:02:26 +0200350 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100351 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
352 <http://www.tldp.org/docs.html#howto>.
353
354 If you don't know what to do here, say N.
355
Josh Triplett9def39be2013-10-30 08:09:45 -0700356config X86_FEATURE_NAMES
357 bool "Processor feature human-readable names" if EMBEDDED
358 default y
359 ---help---
360 This option compiles in a table of x86 feature bits and corresponding
361 names. This is required to support /proc/cpuinfo and a few kernel
362 messages. You can disable this to save space, at the expense of
363 making those few kernel messages show numeric feature bits instead.
364
365 If in doubt, say Y.
366
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100367config X86_FAST_FEATURE_TESTS
368 bool "Fast CPU feature tests" if EMBEDDED
369 default y
370 ---help---
371 Some fast-paths in the kernel depend on the capabilities of the CPU.
372 Say Y here for the kernel to patch in the appropriate code at runtime
373 based on the capabilities of the CPU. The infrastructure for patching
374 code at runtime takes up some additional space; space-constrained
375 embedded systems may wish to say N here to produce smaller, slightly
376 slower code.
377
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800378config X86_X2APIC
379 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200380 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800381 ---help---
382 This enables x2apic support on CPUs that have this feature.
383
384 This allows 32-bit apic IDs (so it can support very large systems),
385 and accesses the local apic via MSRs not via mmio.
386
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800387 If you don't know what to do here, say N.
388
Yinghai Lu6695c852008-06-19 12:13:09 -0700389config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700390 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000391 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200392 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100393 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700394 For old smp systems that do not have proper acpi support. Newer systems
395 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700396
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800397config X86_BIGSMP
398 bool "Support for big SMP systems with more than 8 CPUs"
399 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100400 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800401 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100402
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000403config GOLDFISH
404 def_bool y
405 depends on X86_GOLDFISH
406
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800407if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800408config X86_EXTENDED_PLATFORM
409 bool "Support for extended (non-PC) x86 platforms"
410 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100411 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100412 If you disable this option then the kernel will only support
413 standard PC platforms. (which covers the vast majority of
414 systems out there.)
415
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800416 If you enable this option then you'll be able to select support
417 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100418 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800419 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800420 RDC R-321x SoC
421 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200422 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200423 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100424
425 If you have one of these systems, or if you want to build a
426 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800427endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100428
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800429if X86_64
430config X86_EXTENDED_PLATFORM
431 bool "Support for extended (non-PC) x86 platforms"
432 default y
433 ---help---
434 If you disable this option then the kernel will only support
435 standard PC platforms. (which covers the vast majority of
436 systems out there.)
437
438 If you enable this option then you'll be able to select support
439 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b2011-12-06 00:07:26 +0800440 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800441 ScaleMP vSMP
442 SGI Ultraviolet
443
444 If you have one of these systems, or if you want to build a
445 generic distribution kernel, say Y here - otherwise say N.
446endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800447# This is an alphabetically sorted list of 64 bit extended platforms
448# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b2011-12-06 00:07:26 +0800449config X86_NUMACHIP
450 bool "Numascale NumaChip"
451 depends on X86_64
452 depends on X86_EXTENDED_PLATFORM
453 depends on NUMA
454 depends on SMP
455 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700456 depends on PCI_MMCONFIG
Steffen Persvold44b111b2011-12-06 00:07:26 +0800457 ---help---
458 Adds support for Numascale NumaChip large-SMP systems. Needed to
459 enable more than ~168 cores.
460 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100461
Ingo Molnar6a485652009-01-27 18:29:13 +0100462config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800463 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100464 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100465 select PARAVIRT
466 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800467 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300468 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100469 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100470 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
471 supposed to run on these EM64T-based machines. Only choose this option
472 if you have one of these machines.
473
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800474config X86_UV
475 bool "SGI Ultraviolet"
476 depends on X86_64
477 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500478 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800479 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700480 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200481 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800482 ---help---
483 This option is needed in order to support SGI Ultraviolet systems.
484 If you don't have one of these, you should say N here.
485
486# Following is an alphabetically sorted list of 32 bit extended platforms
487# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100488
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000489config X86_GOLDFISH
490 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100491 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000492 ---help---
493 Enable support for the Goldfish virtual platform used primarily
494 for Android development. Unless you are building for the Android
495 Goldfish emulator say N here.
496
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800497config X86_INTEL_CE
498 bool "CE4100 TV platform"
499 depends on PCI
500 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800501 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800502 depends on X86_32
503 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800504 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100505 select OF
506 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800507 ---help---
508 Select for the Intel CE media processor (CE4100) SOC.
509 This option compiles in support for the CE4100 SOC for settop
510 boxes and media devices.
511
David Cohen4cb9b002013-12-16 17:37:26 -0800512config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100513 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100514 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800515 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000516 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200517 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000518 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000519 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800520 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000521 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000522 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000523 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000524 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000525 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800526 Select to build a kernel capable of supporting Intel MID (Mobile
527 Internet Device) platform systems which do not have the PCI legacy
528 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000529
David Cohen4cb9b002013-12-16 17:37:26 -0800530 Intel MID platforms are based on an Intel processor and chipset which
531 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100532
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000533config X86_INTEL_QUARK
534 bool "Intel Quark platform support"
535 depends on X86_32
536 depends on X86_EXTENDED_PLATFORM
537 depends on X86_PLATFORM_DEVICES
538 depends on X86_TSC
539 depends on PCI
540 depends on PCI_GOANY
541 depends on X86_IO_APIC
542 select IOSF_MBI
543 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200544 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000545 ---help---
546 Select to include support for Quark X1000 SoC.
547 Say Y here if you have a Quark based system such as the Arduino
548 compatible Intel Galileo.
549
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000550config X86_INTEL_LPSS
551 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100552 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000553 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300554 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100555 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000556 ---help---
557 Select to build support for Intel Low Power Subsystem such as
558 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300559 things like clock tree (common clock framework) and pincontrol
560 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000561
Ken Xue92082a82015-02-06 08:27:51 +0800562config X86_AMD_PLATFORM_DEVICE
563 bool "AMD ACPI2Platform devices support"
564 depends on ACPI
565 select COMMON_CLK
566 select PINCTRL
567 ---help---
568 Select to interpret AMD specific ACPI device to platform device
569 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
570 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
571 implemented under PINCTRL subsystem.
572
David E. Boxced3ce72014-09-17 22:13:50 -0700573config IOSF_MBI
574 tristate "Intel SoC IOSF Sideband support for SoC platforms"
575 depends on PCI
576 ---help---
577 This option enables sideband register access support for Intel SoC
578 platforms. On these platforms the IOSF sideband is used in lieu of
579 MSR's for some register accesses, mostly but not limited to thermal
580 and power. Drivers may query the availability of this device to
581 determine if they need the sideband in order to work on these
582 platforms. The sideband is available on the following SoC products.
583 This list is not meant to be exclusive.
584 - BayTrail
585 - Braswell
586 - Quark
587
588 You should say Y if you are running a kernel on one of these SoC's.
589
David E. Boxed2226b2014-09-17 22:13:51 -0700590config IOSF_MBI_DEBUG
591 bool "Enable IOSF sideband access through debugfs"
592 depends on IOSF_MBI && DEBUG_FS
593 ---help---
594 Select this option to expose the IOSF sideband access registers (MCR,
595 MDR, MCRX) through debugfs to write and read register information from
596 different units on the SoC. This is most useful for obtaining device
597 state information for debug and analysis. As this is a general access
598 mechanism, users of this option would have specific knowledge of the
599 device they want to access.
600
601 If you don't require the option or are in doubt, say N.
602
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800603config X86_RDC321X
604 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100605 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800606 depends on X86_EXTENDED_PLATFORM
607 select M486
608 select X86_REBOOTFIXUPS
609 ---help---
610 This option is needed for RDC R-321x system-on-chip, also known
611 as R-8610-(G).
612 If you don't have one of these chips, you should say N here.
613
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100614config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100615 bool "Support non-standard 32-bit SMP architectures"
616 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800617 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100618 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800619 This option compiles in the bigsmp and STA2X11 default
620 subarchitectures. It is intended for a generic binary
621 kernel. If you select them all, kernel will probe it one by
622 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700623
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800624# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700625
Linus Torvaldsd949f362009-09-26 09:35:07 -0700626config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100627 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700628 # MCE code calls memory_failure():
629 depends on X86_MCE
630 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700631 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
632 depends on X86_64 || !SPARSEMEM
633 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700634
Alessandro Rubini83125a32012-04-04 19:40:21 +0200635config STA2X11
636 bool "STA2X11 Companion Chip Support"
637 depends on X86_32_NON_STANDARD && PCI
638 select X86_DEV_DMA_OPS
639 select X86_DMA_REMAP
640 select SWIOTLB
641 select MFD_STA2X11
642 select ARCH_REQUIRE_GPIOLIB
643 default n
644 ---help---
645 This adds support for boards based on the STA2X11 IO-Hub,
646 a.k.a. "ConneXt". The chip is used in place of the standard
647 PC chipset, so all "standard" peripherals are missing. If this
648 option is selected the kernel will still be able to boot on
649 standard PC machines.
650
Shérab82148d12010-09-25 06:06:57 +0200651config X86_32_IRIS
652 tristate "Eurobraille/Iris poweroff module"
653 depends on X86_32
654 ---help---
655 The Iris machines from EuroBraille do not have APM or ACPI support
656 to shut themselves down properly. A special I/O sequence is
657 needed to do so, which is what this module does at
658 kernel shutdown.
659
660 This is only for Iris machines from EuroBraille.
661
662 If unused, say N.
663
Ingo Molnarae1e9132008-11-11 09:05:16 +0100664config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100665 def_bool y
666 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800667 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100668 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100669 Calculate simpler /proc/<PID>/wchan values. If this option
670 is disabled then wchan values will recurse back to the
671 caller function. This provides more accurate wchan values,
672 at the expense of slightly more scheduling overhead.
673
674 If in doubt, say "Y".
675
Borislav Petkov6276a072013-03-04 21:20:21 +0100676menuconfig HYPERVISOR_GUEST
677 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100678 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100679 Say Y here to enable options for running Linux under various hyper-
680 visors. This option enables basic hypervisor detection and platform
681 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100682
Borislav Petkov6276a072013-03-04 21:20:21 +0100683 If you say N, all options in this submenu will be skipped and
684 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100685
Borislav Petkov6276a072013-03-04 21:20:21 +0100686if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100687
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100688config PARAVIRT
689 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100690 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100691 This changes the kernel so it can modify itself when it is run
692 under a hypervisor, potentially improving performance significantly
693 over full virtualization. However, when run without a hypervisor
694 the kernel is theoretically slower and slightly larger.
695
Borislav Petkov6276a072013-03-04 21:20:21 +0100696config PARAVIRT_DEBUG
697 bool "paravirt-ops debugging"
698 depends on PARAVIRT && DEBUG_KERNEL
699 ---help---
700 Enable to debug paravirt_ops internals. Specifically, BUG if
701 a paravirt_op is missing when it is called.
702
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700703config PARAVIRT_SPINLOCKS
704 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700705 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200706 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700707 ---help---
708 Paravirtualized spinlocks allow a pvops backend to replace the
709 spinlock implementation with something virtualization-friendly
710 (for example, block the virtual CPU rather than spinning).
711
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530712 It has a minimal impact on native kernels and gives a nice performance
713 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700714
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530715 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700716
Waiman Long45e898b2015-11-09 19:09:25 -0500717config QUEUED_LOCK_STAT
718 bool "Paravirt queued spinlock statistics"
719 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
720 ---help---
721 Enable the collection of statistical data on the slowpath
722 behavior of paravirtualized queued spinlocks and report
723 them on debugfs.
724
Borislav Petkov6276a072013-03-04 21:20:21 +0100725source "arch/x86/xen/Kconfig"
726
727config KVM_GUEST
728 bool "KVM Guest support (including kvmclock)"
729 depends on PARAVIRT
730 select PARAVIRT_CLOCK
731 default y
732 ---help---
733 This option enables various optimizations for running under the KVM
734 hypervisor. It includes a paravirtualized clock, so that instead
735 of relying on a PIT (or probably other) emulation by the
736 underlying device model, the host provides the guest with
737 timing infrastructure such as time of day, and system time
738
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530739config KVM_DEBUG_FS
740 bool "Enable debug information for KVM Guests in debugfs"
741 depends on KVM_GUEST && DEBUG_FS
742 default n
743 ---help---
744 This option enables collection of various statistics for KVM guest.
745 Statistics are displayed in debugfs filesystem. Enabling this option
746 may incur significant overhead.
747
Borislav Petkov6276a072013-03-04 21:20:21 +0100748source "arch/x86/lguest/Kconfig"
749
750config PARAVIRT_TIME_ACCOUNTING
751 bool "Paravirtual steal time accounting"
752 depends on PARAVIRT
753 default n
754 ---help---
755 Select this option to enable fine granularity task steal time
756 accounting. Time spent executing other tasks in parallel with
757 the current vCPU is discounted from the vCPU power. To account for
758 that, there can be a small performance impact.
759
760 If in doubt, say N here.
761
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200762config PARAVIRT_CLOCK
763 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200764
Borislav Petkov6276a072013-03-04 21:20:21 +0100765endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400766
Yinghai Lu08677212010-02-10 01:20:20 -0800767config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700768 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800769
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100770source "arch/x86/Kconfig.cpu"
771
772config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100773 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100774 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100775 ---help---
776 Use the IA-PC HPET (High Precision Event Timer) to manage
777 time in preference to the PIT and RTC, if a HPET is
778 present.
779 HPET is the next generation timer replacing legacy 8254s.
780 The HPET provides a stable time base on SMP
781 systems, unlike the TSC, but it is more expensive to access,
782 as it is off-chip. You can find the HPET spec at
783 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100784
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100785 You can safely choose Y here. However, HPET will only be
786 activated if the platform and the BIOS support this feature.
787 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100788
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100789 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100790
791config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100792 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800793 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100794
Jacob Panbb24c472009-09-02 07:37:17 -0700795config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000796 def_bool y if X86_INTEL_MID
797 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100798 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000799 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700800 help
801 APB timer is the replacement for 8254, HPET on X86 MID platforms.
802 The APBT provides a stable time base on SMP
803 systems, unlike the TSC, but it is more expensive to access,
804 as it is off-chip. APB timers are always running regardless of CPU
805 C states, they are used as per CPU clockevent device when possible.
806
David Rientjes6a108a12011-01-20 14:44:16 -0800807# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100808# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700809config DMI
810 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800811 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800812 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100813 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700814 Enabled scanning of DMI to identify machine quirks. Say Y
815 here unless you have verified that your setup is not
816 affected by entries in the DMI blacklist. Required by PNP
817 BIOS code.
818
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100819config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700820 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100821 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200822 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100823 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200824 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
825 GART based hardware IOMMUs.
826
827 The GART supports full DMA access for devices with 32-bit access
828 limitations, on systems with more than 3 GB. This is usually needed
829 for USB, sound, many IDE/SATA chipsets and some other devices.
830
831 Newer systems typically have a modern AMD IOMMU, supported via
832 the CONFIG_AMD_IOMMU=y config option.
833
834 In normal configurations this driver is only active when needed:
835 there's more than 3 GB of memory and the system contains a
836 32-bit limited device.
837
838 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100839
840config CALGARY_IOMMU
841 bool "IBM Calgary IOMMU support"
842 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700843 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100844 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100845 Support for hardware IOMMUs in IBM's xSeries x366 and x460
846 systems. Needed to run systems with more than 3GB of memory
847 properly with 32-bit PCI devices that do not support DAC
848 (Double Address Cycle). Calgary also supports bus level
849 isolation, where all DMAs pass through the IOMMU. This
850 prevents them from going anywhere except their intended
851 destination. This catches hard-to-find kernel bugs and
852 mis-behaving drivers and devices that do not use the DMA-API
853 properly to set up their DMA buffers. The IOMMU can be
854 turned off at boot time with the iommu=off parameter.
855 Normally the kernel will make the right choice by itself.
856 If unsure, say Y.
857
858config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100859 def_bool y
860 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100861 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100862 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100863 Should Calgary be enabled by default? if you choose 'y', Calgary
864 will be used (if it exists). If you choose 'n', Calgary will not be
865 used even if it exists. If you choose 'n' and would like to use
866 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
867 If unsure, say Y.
868
869# need this always selected by IOMMU for the VIA workaround
870config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100871 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100872 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100873 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700874 which don't have a hardware IOMMU. Using this PCI devices
875 which can only access 32-bits of memory can be used on systems
876 with more than 3 GB of memory.
877 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100878
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700879config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100880 def_bool y
881 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700882
Mike Travis1184dc22008-05-12 21:21:12 +0200883config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200884 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700885 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800886 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100887 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200888 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200889 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100890
891config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800892 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400893 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500894 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500895 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800896 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500897 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800898 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300899 default "8" if SMP && X86_32
900 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100901 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100902 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500903 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300904 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100905 minimum value which makes sense is 2.
906
907 This is purely to save memory - each supported CPU adds
908 approximately eight kilobytes to the kernel image.
909
910config SCHED_SMT
911 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200912 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100913 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100914 SMT scheduler support improves the CPU scheduler's decision making
915 when dealing with Intel Pentium 4 chips with HyperThreading at a
916 cost of slightly increased overhead in some places. If unsure say
917 N here.
918
919config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100920 def_bool y
921 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200922 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100923 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100924 Multi-core scheduler support improves the CPU scheduler's decision
925 making when dealing with multi-core CPU chips at a cost of slightly
926 increased overhead in some places. If unsure say N here.
927
928source "kernel/Kconfig.preempt"
929
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000930config UP_LATE_INIT
931 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100932 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000933
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100934config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000935 bool "Local APIC support on uniprocessors" if !PCI_MSI
936 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000937 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100938 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100939 A local APIC (Advanced Programmable Interrupt Controller) is an
940 integrated interrupt controller in the CPU. If you have a single-CPU
941 system which has a processor with a local APIC, you can say Y here to
942 enable and use it. If you say Y here even though your machine doesn't
943 have a local APIC, then the kernel will still run with no slowdown at
944 all. The local APIC supports CPU-generated self-interrupts (timer,
945 performance counters), and the NMI watchdog which detects hard
946 lockups.
947
948config X86_UP_IOAPIC
949 bool "IO-APIC support on uniprocessors"
950 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100951 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100952 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
953 SMP-capable replacement for PC-style interrupt controllers. Most
954 SMP systems and many recent uniprocessor systems have one.
955
956 If you have a single-CPU system with an IO-APIC, you can say Y here
957 to use it. If you say Y here even though your machine doesn't have
958 an IO-APIC, then the kernel will still run with no slowdown at all.
959
960config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100961 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200962 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800963 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800964 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100965
966config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000967 def_bool y
968 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100969
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200970config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
971 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200972 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100973 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200974 This option enables a workaround that fixes a source of
975 spurious interrupts. This is recommended when threaded
976 interrupt handling is used on systems where the generation of
977 superfluous "boot interrupts" cannot be disabled.
978
979 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
980 entry in the chipset's IO-APIC is masked (as, e.g. the RT
981 kernel does during interrupt handling). On chipsets where this
982 boot IRQ generation cannot be disabled, this workaround keeps
983 the original IRQ line masked so that only the equivalent "boot
984 IRQ" is delivered to the CPUs. The workaround also tells the
985 kernel to set up the IRQ handler on the boot IRQ line. In this
986 way only one interrupt is delivered to the kernel. Otherwise
987 the spurious second interrupt may cause the kernel to bring
988 down (vital) interrupt lines.
989
990 Only affects "broken" chipsets. Interrupt sharing may be
991 increased on these systems.
992
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100993config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200994 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +0200995 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +0200996 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100997 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +0200998 Machine Check support allows the processor to notify the
999 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001000 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001001 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001002
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001003config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001004 def_bool y
1005 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001006 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001007 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001008 Additional support for intel specific MCE features such as
1009 the thermal monitor.
1010
1011config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001012 def_bool y
1013 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001014 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001015 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001016 Additional support for AMD specific MCE features such as
1017 the DRAM Error Threshold.
1018
Andi Kleen4efc0672009-04-28 19:07:31 +02001019config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001020 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001021 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001022 ---help---
1023 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001024 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001025 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001026
Andi Kleenb2762682009-02-12 13:49:31 +01001027config X86_MCE_THRESHOLD
1028 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001029 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001030
Andi Kleenea149b32009-04-29 19:31:00 +02001031config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001032 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001033 tristate "Machine check injector support"
1034 ---help---
1035 Provide support for injecting machine checks for testing purposes.
1036 If you don't know what a machine check is and you don't do kernel
1037 QA it is safe to say n.
1038
Andi Kleen4efc0672009-04-28 19:07:31 +02001039config X86_THERMAL_VECTOR
1040 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001041 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001042
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001043config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001044 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001045 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001046 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001047 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001048 This option allows user programs to put the CPU into V8086
1049 mode, which is an 80286-era approximation of 16-bit real mode.
1050
1051 Some very old versions of X and/or vbetool require this option
1052 for user mode setting. Similarly, DOSEMU will use it if
1053 available to accelerate real mode DOS programs. However, any
1054 recent version of DOSEMU, X, or vbetool should be fully
1055 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001056 fall back to software emulation. Nevertheless, if you are using
1057 a 16-bit DOS program where 16-bit performance matters, vm86
1058 mode might be faster than emulation and you might want to
1059 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001060
Ingo Molnar1e642812015-09-05 08:58:10 +02001061 Note that any app that works on a 64-bit kernel is unlikely to
1062 need this option, as 64-bit kernels don't, and can't, support
1063 V8086 mode. This option is also unrelated to 16-bit protected
1064 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001065
Ingo Molnar1e642812015-09-05 08:58:10 +02001066 Enabling this option increases the complexity of the kernel
1067 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001068
Ingo Molnar1e642812015-09-05 08:58:10 +02001069 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001070
1071config VM86
1072 bool
1073 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001074
1075config X86_16BIT
1076 bool "Enable support for 16-bit segments" if EXPERT
1077 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001078 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001079 ---help---
1080 This option is required by programs like Wine to run 16-bit
1081 protected mode legacy code on x86 processors. Disabling
1082 this option saves about 300 bytes on i386, or around 6K text
1083 plus 16K runtime memory on x86-64,
1084
1085config X86_ESPFIX32
1086 def_bool y
1087 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001088
H. Peter Anvin197725d2014-05-04 10:00:49 -07001089config X86_ESPFIX64
1090 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001091 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001092
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001093config X86_VSYSCALL_EMULATION
1094 bool "Enable vsyscall emulation" if EXPERT
1095 default y
1096 depends on X86_64
1097 ---help---
1098 This enables emulation of the legacy vsyscall page. Disabling
1099 it is roughly equivalent to booting with vsyscall=none, except
1100 that it will also disable the helpful warning if a program
1101 tries to use a vsyscall. With this option set to N, offending
1102 programs will just segfault, citing addresses of the form
1103 0xffffffffff600?00.
1104
1105 This option is required by many programs built before 2013, and
1106 care should be used even with newer programs if set to N.
1107
1108 Disabling this option saves about 7K of kernel size and
1109 possibly 4K of additional runtime pagetable memory.
1110
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001111config TOSHIBA
1112 tristate "Toshiba Laptop support"
1113 depends on X86_32
1114 ---help---
1115 This adds a driver to safely access the System Management Mode of
1116 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1117 not work on models with a Phoenix BIOS. The System Management Mode
1118 is used to set the BIOS and power saving options on Toshiba portables.
1119
1120 For information on utilities to make use of this driver see the
1121 Toshiba Linux utilities web site at:
1122 <http://www.buzzard.org.uk/toshiba/>.
1123
1124 Say Y if you intend to run this kernel on a Toshiba portable.
1125 Say N otherwise.
1126
1127config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001128 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001129 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001130 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001131 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001132 This option enables legacy /proc/i8k userspace interface in hwmon
1133 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1134 temperature and allows controlling fan speeds of Dell laptops via
1135 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1136 it reports also power and hotkey status. For fan speed control is
1137 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001138
Pali Rohár039ae582015-05-14 13:16:37 +02001139 Say Y if you intend to run this kernel on old Dell laptops or want to
1140 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001141 Say N otherwise.
1142
1143config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001144 bool "Enable X86 board specific fixups for reboot"
1145 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001146 ---help---
1147 This enables chipset and/or board specific fixups to be done
1148 in order to get reboot to work correctly. This is only needed on
1149 some combinations of hardware and BIOS. The symptom, for which
1150 this config is intended, is when reboot ends with a stalled/hung
1151 system.
1152
1153 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001154 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001155
1156 Say Y if you want to enable the fixup. Currently, it's safe to
1157 enable this option even if you don't need it.
1158 Say N otherwise.
1159
1160config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001161 bool "CPU microcode loading support"
1162 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001163 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Borislav Petkovfe055892015-10-20 11:54:45 +02001164 depends on BLK_DEV_INITRD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001165 select FW_LOADER
1166 ---help---
Borislav Petkove43f6e62012-08-01 19:17:01 +02001167
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001168 If you say Y here, you will be able to update the microcode on
Peter Oruba80cc9f12008-07-28 18:44:22 +02001169 certain Intel and AMD processors. The Intel support is for the
Borislav Petkove43f6e62012-08-01 19:17:01 +02001170 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1171 Xeon etc. The AMD support is for families 0x10 and later. You will
1172 obviously need the actual microcode binary data itself which is not
1173 shipped with the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001174
Peter Oruba8d86f392008-07-28 18:44:21 +02001175 This option selects the general module only, you need to select
1176 at least one vendor specific module as well.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001177
Borislav Petkove43f6e62012-08-01 19:17:01 +02001178 To compile this driver as a module, choose M here: the module
1179 will be called microcode.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001180
Peter Oruba8d86f392008-07-28 18:44:21 +02001181config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001182 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001183 depends on MICROCODE
1184 default MICROCODE
1185 select FW_LOADER
1186 ---help---
1187 This options enables microcode patch loading support for Intel
1188 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001189
Alanb8989db2014-01-20 18:01:56 +00001190 For the current Intel microcode data package go to
1191 <https://downloadcenter.intel.com> and search for
1192 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001193
Peter Oruba80cc9f12008-07-28 18:44:22 +02001194config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001195 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001196 depends on MICROCODE
1197 select FW_LOADER
1198 ---help---
1199 If you select this option, microcode patch loading support for AMD
1200 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001201
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001202config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001203 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001204 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001205
1206config X86_MSR
1207 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001208 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001209 This device gives privileged processes access to the x86
1210 Model-Specific Registers (MSRs). It is a character device with
1211 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1212 MSR accesses are directed to a specific CPU on multi-processor
1213 systems.
1214
1215config X86_CPUID
1216 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001217 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001218 This device gives processes access to the x86 CPUID instruction to
1219 be executed on a specific processor. It is a character device
1220 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1221 /dev/cpu/31/cpuid.
1222
1223choice
1224 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001225 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001226 depends on X86_32
1227
1228config NOHIGHMEM
1229 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001230 ---help---
1231 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1232 However, the address space of 32-bit x86 processors is only 4
1233 Gigabytes large. That means that, if you have a large amount of
1234 physical memory, not all of it can be "permanently mapped" by the
1235 kernel. The physical memory that's not permanently mapped is called
1236 "high memory".
1237
1238 If you are compiling a kernel which will never run on a machine with
1239 more than 1 Gigabyte total physical RAM, answer "off" here (default
1240 choice and suitable for most users). This will result in a "3GB/1GB"
1241 split: 3GB are mapped so that each process sees a 3GB virtual memory
1242 space and the remaining part of the 4GB virtual memory space is used
1243 by the kernel to permanently map as much physical memory as
1244 possible.
1245
1246 If the machine has between 1 and 4 Gigabytes physical RAM, then
1247 answer "4GB" here.
1248
1249 If more than 4 Gigabytes is used then answer "64GB" here. This
1250 selection turns Intel PAE (Physical Address Extension) mode on.
1251 PAE implements 3-level paging on IA32 processors. PAE is fully
1252 supported by Linux, PAE mode is implemented on all recent Intel
1253 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1254 then the kernel will not boot on CPUs that don't support PAE!
1255
1256 The actual amount of total physical memory will either be
1257 auto detected or can be forced by using a kernel command line option
1258 such as "mem=256M". (Try "man bootparam" or see the documentation of
1259 your boot loader (lilo or loadlin) about how to pass options to the
1260 kernel at boot time.)
1261
1262 If unsure, say "off".
1263
1264config HIGHMEM4G
1265 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001266 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001267 Select this if you have a 32-bit processor and between 1 and 4
1268 gigabytes of physical RAM.
1269
1270config HIGHMEM64G
1271 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001272 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001273 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001274 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001275 Select this if you have a 32-bit processor and more than 4
1276 gigabytes of physical RAM.
1277
1278endchoice
1279
1280choice
David Rientjes6a108a12011-01-20 14:44:16 -08001281 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001282 default VMSPLIT_3G
1283 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001284 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001285 Select the desired split between kernel and user memory.
1286
1287 If the address range available to the kernel is less than the
1288 physical memory installed, the remaining memory will be available
1289 as "high memory". Accessing high memory is a little more costly
1290 than low memory, as it needs to be mapped into the kernel first.
1291 Note that increasing the kernel address space limits the range
1292 available to user programs, making the address space there
1293 tighter. Selecting anything other than the default 3G/1G split
1294 will also likely make your kernel incompatible with binary-only
1295 kernel modules.
1296
1297 If you are not absolutely sure what you are doing, leave this
1298 option alone!
1299
1300 config VMSPLIT_3G
1301 bool "3G/1G user/kernel split"
1302 config VMSPLIT_3G_OPT
1303 depends on !X86_PAE
1304 bool "3G/1G user/kernel split (for full 1G low memory)"
1305 config VMSPLIT_2G
1306 bool "2G/2G user/kernel split"
1307 config VMSPLIT_2G_OPT
1308 depends on !X86_PAE
1309 bool "2G/2G user/kernel split (for full 2G low memory)"
1310 config VMSPLIT_1G
1311 bool "1G/3G user/kernel split"
1312endchoice
1313
1314config PAGE_OFFSET
1315 hex
1316 default 0xB0000000 if VMSPLIT_3G_OPT
1317 default 0x80000000 if VMSPLIT_2G
1318 default 0x78000000 if VMSPLIT_2G_OPT
1319 default 0x40000000 if VMSPLIT_1G
1320 default 0xC0000000
1321 depends on X86_32
1322
1323config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001324 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001325 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001326
1327config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001328 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001329 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001330 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001331 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001332 PAE is required for NX support, and furthermore enables
1333 larger swapspace support for non-overcommit purposes. It
1334 has the cost of more pagetable lookup overhead, and also
1335 consumes more pagetable space per process.
1336
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001337config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001338 def_bool y
1339 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001340
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001341config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001342 def_bool y
1343 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001344
Ingo Molnar10971ab2015-03-05 08:18:23 +01001345config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001346 def_bool y
1347 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001348 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001349 Certain kernel features effectively disable kernel
1350 linear 1 GB mappings (even if the CPU otherwise
1351 supports them), so don't confuse the user by printing
1352 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001353
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001354# Common NUMA Features
1355config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001356 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001357 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001358 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1359 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001360 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001361 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001362
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001363 The kernel will try to allocate memory used by a CPU on the
1364 local memory controller of the CPU and add some more
1365 NUMA awareness to the kernel.
1366
Ingo Molnarc280ea52008-11-08 13:29:45 +01001367 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001368 (or later), AMD Opteron, or EM64T NUMA.
1369
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001370 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001371 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001372
1373 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001374
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001375config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001376 def_bool y
1377 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001378 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001379 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001380 Enable AMD NUMA node topology detection. You should say Y here if
1381 you have a multi processor AMD system. This uses an old method to
1382 read the NUMA configuration directly from the builtin Northbridge
1383 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1384 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001385
1386config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001387 def_bool y
1388 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001389 depends on X86_64 && NUMA && ACPI && PCI
1390 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001391 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001392 Enable ACPI SRAT based node topology detection.
1393
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001394# Some NUMA nodes have memory ranges that span
1395# other nodes. Even though a pfn is valid and
1396# between a node's start and end pfns, it may not
1397# reside on that node. See memmap_init_zone()
1398# for details.
1399config NODES_SPAN_OTHER_NODES
1400 def_bool y
1401 depends on X86_64_ACPI_NUMA
1402
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001403config NUMA_EMU
1404 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001405 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001406 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001407 Enable NUMA emulation. A flat machine will be split
1408 into virtual nodes when booted with "numa=fake=N", where N is the
1409 number of nodes. This is only useful for debugging.
1410
1411config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001412 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001413 range 1 10
1414 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001415 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001416 default "3"
1417 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001418 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001419 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001420 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001421
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001422config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001423 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001424 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001425
1426config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001427 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001428 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001429
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001430config ARCH_FLATMEM_ENABLE
1431 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001432 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001433
1434config ARCH_DISCONTIGMEM_ENABLE
1435 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001436 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001437
1438config ARCH_DISCONTIGMEM_DEFAULT
1439 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001440 depends on NUMA && X86_32
1441
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001442config ARCH_SPARSEMEM_ENABLE
1443 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001444 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001445 select SPARSEMEM_STATIC if X86_32
1446 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1447
Tejun Heo3b166512011-04-01 11:15:12 +02001448config ARCH_SPARSEMEM_DEFAULT
1449 def_bool y
1450 depends on X86_64
1451
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001452config ARCH_SELECT_MEMORY_MODEL
1453 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001454 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001455
1456config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001457 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001458 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001459 help
1460 This option enables a sysfs memory/probe interface for testing.
1461 See Documentation/memory-hotplug.txt for more information.
1462 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001463
Tejun Heo3b166512011-04-01 11:15:12 +02001464config ARCH_PROC_KCORE_TEXT
1465 def_bool y
1466 depends on X86_64 && PROC_KCORE
1467
Avi Kivitya29815a2010-01-10 16:28:09 +02001468config ILLEGAL_POINTER_VALUE
1469 hex
1470 default 0 if X86_32
1471 default 0xdead000000000000 if X86_64
1472
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001473source "mm/Kconfig"
1474
Dan Williams7a678322015-08-19 00:34:34 -04001475config X86_PMEM_LEGACY_DEVICE
1476 bool
1477
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001478config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001479 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001480 depends on PHYS_ADDR_T_64BIT
1481 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001482 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001483 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001484 help
1485 Treat memory marked using the non-standard e820 type of 12 as used
1486 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1487 The kernel will offer these regions to the 'pmem' driver so
1488 they can be used for persistent storage.
1489
1490 Say Y if unsure.
1491
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001492config HIGHPTE
1493 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001494 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001495 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001496 The VM uses one page table entry for each page of physical memory.
1497 For systems with a lot of RAM, this can be wasteful of precious
1498 low memory. Setting this option will put user-space page table
1499 entries in high memory.
1500
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001501config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001502 bool "Check for low memory corruption"
1503 ---help---
1504 Periodically check for memory corruption in low memory, which
1505 is suspected to be caused by BIOS. Even when enabled in the
1506 configuration, it is disabled at runtime. Enable it by
1507 setting "memory_corruption_check=1" on the kernel command
1508 line. By default it scans the low 64k of memory every 60
1509 seconds; see the memory_corruption_check_size and
1510 memory_corruption_check_period parameters in
1511 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001512
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001513 When enabled with the default parameters, this option has
1514 almost no overhead, as it reserves a relatively small amount
1515 of memory and scans it infrequently. It both detects corruption
1516 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001517
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001518 It is, however, intended as a diagnostic tool; if repeatable
1519 BIOS-originated corruption always affects the same memory,
1520 you can use memmap= to prevent the kernel from using that
1521 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001522
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001523config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001524 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001525 depends on X86_CHECK_BIOS_CORRUPTION
1526 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001527 ---help---
1528 Set whether the default state of memory_corruption_check is
1529 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001530
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001531config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001532 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1533 default 64
1534 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001535 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001536 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001537
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001538 The first page contains BIOS data structures that the kernel
1539 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001540
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001541 By default we reserve the first 64K of physical RAM, as a
1542 number of BIOSes are known to corrupt that memory range
1543 during events such as suspend/resume or monitor cable
1544 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001545
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001546 You can set this to 4 if you are absolutely sure that you
1547 trust the BIOS to get all its memory reservations and usages
1548 right. If you know your BIOS have problems beyond the
1549 default 64K area, you can set this to 640 to avoid using the
1550 entire low memory range.
1551
1552 If you have doubts about the BIOS (e.g. suspend/resume does
1553 not work or there's kernel crashes after certain hardware
1554 hotplug events) then you might want to enable
1555 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1556 typical corruption patterns.
1557
1558 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001559
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001560config MATH_EMULATION
1561 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001562 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001563 prompt "Math emulation" if X86_32
1564 ---help---
1565 Linux can emulate a math coprocessor (used for floating point
1566 operations) if you don't have one. 486DX and Pentium processors have
1567 a math coprocessor built in, 486SX and 386 do not, unless you added
1568 a 487DX or 387, respectively. (The messages during boot time can
1569 give you some hints here ["man dmesg"].) Everyone needs either a
1570 coprocessor or this emulation.
1571
1572 If you don't have a math coprocessor, you need to say Y here; if you
1573 say Y here even though you have a coprocessor, the coprocessor will
1574 be used nevertheless. (This behavior can be changed with the kernel
1575 command line option "no387", which comes handy if your coprocessor
1576 is broken. Try "man bootparam" or see the documentation of your boot
1577 loader (lilo or loadlin) about how to pass options to the kernel at
1578 boot time.) This means that it is a good idea to say Y here if you
1579 intend to use this kernel on different machines.
1580
1581 More information about the internals of the Linux math coprocessor
1582 emulation can be found in <file:arch/x86/math-emu/README>.
1583
1584 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1585 kernel, it won't hurt.
1586
1587config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001588 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001589 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001590 ---help---
1591 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1592 the Memory Type Range Registers (MTRRs) may be used to control
1593 processor access to memory ranges. This is most useful if you have
1594 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1595 allows bus write transfers to be combined into a larger transfer
1596 before bursting over the PCI/AGP bus. This can increase performance
1597 of image write operations 2.5 times or more. Saying Y here creates a
1598 /proc/mtrr file which may be used to manipulate your processor's
1599 MTRRs. Typically the X server should use this.
1600
1601 This code has a reasonably generic interface so that similar
1602 control registers on other processors can be easily supported
1603 as well:
1604
1605 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1606 Registers (ARRs) which provide a similar functionality to MTRRs. For
1607 these, the ARRs are used to emulate the MTRRs.
1608 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1609 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1610 write-combining. All of these processors are supported by this code
1611 and it makes sense to say Y here if you have one of them.
1612
1613 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1614 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1615 can lead to all sorts of problems, so it's good to say Y here.
1616
1617 You can safely say Y even if your machine doesn't have MTRRs, you'll
1618 just add about 9 KB to your kernel.
1619
Randy Dunlap7225e752008-07-26 17:54:22 -07001620 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001621
Yinghai Lu95ffa242008-04-29 03:52:33 -07001622config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001623 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001624 prompt "MTRR cleanup support"
1625 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001626 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001627 Convert MTRR layout from continuous to discrete, so X drivers can
1628 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001629
Thomas Gleixneraba37282008-07-15 14:48:48 +02001630 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001631 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001632 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001633
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001634 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001635
1636config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001637 int "MTRR cleanup enable value (0-1)"
1638 range 0 1
1639 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001640 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001641 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001642 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001643
Yinghai Lu12031a62008-05-02 02:40:22 -07001644config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1645 int "MTRR cleanup spare reg num (0-7)"
1646 range 0 7
1647 default "1"
1648 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001649 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001650 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001651 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001652
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001653config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001654 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001655 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001656 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001657 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001658 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001659
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001660 PATs are the modern equivalents of MTRRs and are much more
1661 flexible than MTRRs.
1662
1663 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001664 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001665
1666 If unsure, say Y.
1667
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001668config ARCH_USES_PG_UNCACHED
1669 def_bool y
1670 depends on X86_PAT
1671
H. Peter Anvin628c6242011-07-31 13:59:29 -07001672config ARCH_RANDOM
1673 def_bool y
1674 prompt "x86 architectural random number generator" if EXPERT
1675 ---help---
1676 Enable the x86 architectural RDRAND instruction
1677 (Intel Bull Mountain technology) to generate random numbers.
1678 If supported, this is a high bandwidth, cryptographically
1679 secure hardware random number generator.
1680
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001681config X86_SMAP
1682 def_bool y
1683 prompt "Supervisor Mode Access Prevention" if EXPERT
1684 ---help---
1685 Supervisor Mode Access Prevention (SMAP) is a security
1686 feature in newer Intel processors. There is a small
1687 performance cost if this enabled and turned on; there is
1688 also a small increase in the kernel size if this is enabled.
1689
1690 If unsure, say Y.
1691
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001692config X86_INTEL_MPX
1693 prompt "Intel MPX (Memory Protection Extensions)"
1694 def_bool n
1695 depends on CPU_SUP_INTEL
1696 ---help---
1697 MPX provides hardware features that can be used in
1698 conjunction with compiler-instrumented code to check
1699 memory references. It is designed to detect buffer
1700 overflow or underflow bugs.
1701
1702 This option enables running applications which are
1703 instrumented or otherwise use MPX. It does not use MPX
1704 itself inside the kernel or to protect the kernel
1705 against bad memory references.
1706
1707 Enabling this option will make the kernel larger:
1708 ~8k of kernel text and 36 bytes of data on a 64-bit
1709 defconfig. It adds a long to the 'mm_struct' which
1710 will increase the kernel memory overhead of each
1711 process and adds some branches to paths used during
1712 exec() and munmap().
1713
1714 For details, see Documentation/x86/intel_mpx.txt
1715
1716 If unsure, say N.
1717
Dave Hansen35e97792016-02-12 13:02:00 -08001718config X86_INTEL_MEMORY_PROTECTION_KEYS
1719 def_bool y
1720 depends on CPU_SUP_INTEL && X86_64
1721
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001722config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001723 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001724 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001725 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001726 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001727 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001728 This enables the kernel to use EFI runtime services that are
1729 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001730
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001731 This option is only useful on systems that have EFI firmware.
1732 In addition, you should use the latest ELILO loader available
1733 at <http://elilo.sourceforge.net> in order to take advantage
1734 of EFI runtime services. However, even with this option, the
1735 resultant kernel should continue to boot on existing non-EFI
1736 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001737
Matt Fleming291f3632011-12-12 21:27:52 +00001738config EFI_STUB
1739 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001740 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001741 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001742 ---help---
1743 This kernel feature allows a bzImage to be loaded directly
1744 by EFI firmware without the use of a bootloader.
1745
Roy Franz4172fe22013-09-22 15:45:25 -07001746 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001747
Matt Fleming7d453ee2014-01-10 18:52:06 +00001748config EFI_MIXED
1749 bool "EFI mixed-mode support"
1750 depends on EFI_STUB && X86_64
1751 ---help---
1752 Enabling this feature allows a 64-bit kernel to be booted
1753 on a 32-bit firmware, provided that your CPU supports 64-bit
1754 mode.
1755
1756 Note that it is not possible to boot a mixed-mode enabled
1757 kernel via the EFI boot stub - a bootloader that supports
1758 the EFI handover protocol must be used.
1759
1760 If unsure, say N.
1761
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001762config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001763 def_bool y
1764 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001765 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001766 This kernel feature is useful for number crunching applications
1767 that may need to compute untrusted bytecode during their
1768 execution. By using pipes or other transports made available to
1769 the process as file descriptors supporting the read/write
1770 syscalls, it's possible to isolate those applications in
1771 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001772 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001773 and the task is only allowed to execute a few safe syscalls
1774 defined by each seccomp mode.
1775
1776 If unsure, say Y. Only embedded should say N here.
1777
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001778source kernel/Kconfig.hz
1779
1780config KEXEC
1781 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001782 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001783 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001784 kexec is a system call that implements the ability to shutdown your
1785 current kernel, and to start another kernel. It is like a reboot
1786 but it is independent of the system firmware. And like a reboot
1787 you can start any kernel with it, not just Linux.
1788
1789 The name comes from the similarity to the exec system call.
1790
1791 It is an ongoing process to be certain the hardware in a machine
1792 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001793 initially work for you. As of this writing the exact hardware
1794 interface is strongly in flux, so no good recommendation can be
1795 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001796
Vivek Goyal74ca3172014-08-29 15:18:46 -07001797config KEXEC_FILE
1798 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001799 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001800 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001801 depends on X86_64
1802 depends on CRYPTO=y
1803 depends on CRYPTO_SHA256=y
1804 ---help---
1805 This is new version of kexec system call. This system call is
1806 file based and takes file descriptors as system call argument
1807 for kernel and initramfs as opposed to list of segments as
1808 accepted by previous system call.
1809
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001810config KEXEC_VERIFY_SIG
1811 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001812 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001813 ---help---
1814 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001815 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001816
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001817 In addition to that option, you need to enable signature
1818 verification for the corresponding kernel image type being
1819 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001820
1821config KEXEC_BZIMAGE_VERIFY_SIG
1822 bool "Enable bzImage signature verification support"
1823 depends on KEXEC_VERIFY_SIG
1824 depends on SIGNED_PE_FILE_VERIFICATION
1825 select SYSTEM_TRUSTED_KEYRING
1826 ---help---
1827 Enable bzImage signature verification support.
1828
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001829config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001830 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001831 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001832 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001833 Generate crash dump after being started by kexec.
1834 This should be normally only set in special crash dump kernels
1835 which are loaded in the main kernel with kexec-tools into
1836 a specially reserved region and then later executed after
1837 a crash by kdump/kexec. The crash dump kernel must be compiled
1838 to a memory address not used by the main kernel or BIOS using
1839 PHYSICAL_START, or it must be built as a relocatable image
1840 (CONFIG_RELOCATABLE=y).
1841 For more details see Documentation/kdump/kdump.txt
1842
Huang Ying3ab83522008-07-25 19:45:07 -07001843config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001844 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001845 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001846 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001847 Jump between original kernel and kexeced kernel and invoke
1848 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001849
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001850config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001851 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001852 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001853 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001854 This gives the physical address where the kernel is loaded.
1855
1856 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1857 bzImage will decompress itself to above physical address and
1858 run from there. Otherwise, bzImage will run from the address where
1859 it has been loaded by the boot loader and will ignore above physical
1860 address.
1861
1862 In normal kdump cases one does not have to set/change this option
1863 as now bzImage can be compiled as a completely relocatable image
1864 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1865 address. This option is mainly useful for the folks who don't want
1866 to use a bzImage for capturing the crash dump and want to use a
1867 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1868 to be specifically compiled to run from a specific memory area
1869 (normally a reserved region) and this option comes handy.
1870
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001871 So if you are using bzImage for capturing the crash dump,
1872 leave the value here unchanged to 0x1000000 and set
1873 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1874 for capturing the crash dump change this value to start of
1875 the reserved region. In other words, it can be set based on
1876 the "X" value as specified in the "crashkernel=YM@XM"
1877 command line boot parameter passed to the panic-ed
1878 kernel. Please take a look at Documentation/kdump/kdump.txt
1879 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001880
1881 Usage of bzImage for capturing the crash dump is recommended as
1882 one does not have to build two kernels. Same kernel can be used
1883 as production kernel and capture kernel. Above option should have
1884 gone away after relocatable bzImage support is introduced. But it
1885 is present because there are users out there who continue to use
1886 vmlinux for dump capture. This option should go away down the
1887 line.
1888
1889 Don't change this unless you know what you are doing.
1890
1891config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001892 bool "Build a relocatable kernel"
1893 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001894 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001895 This builds a kernel image that retains relocation information
1896 so it can be loaded someplace besides the default 1MB.
1897 The relocations tend to make the kernel binary about 10% larger,
1898 but are discarded at runtime.
1899
1900 One use is for the kexec on panic case where the recovery kernel
1901 must live at a different physical address than the primary
1902 kernel.
1903
1904 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1905 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001906 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001907
Kees Cook8ab38202013-10-10 17:18:14 -07001908config RANDOMIZE_BASE
1909 bool "Randomize the address of the kernel image"
1910 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001911 default n
1912 ---help---
1913 Randomizes the physical and virtual address at which the
1914 kernel image is decompressed, as a security feature that
1915 deters exploit attempts relying on knowledge of the location
1916 of kernel internals.
1917
Kees Cooka653f352013-11-11 14:28:39 -08001918 Entropy is generated using the RDRAND instruction if it is
1919 supported. If RDTSC is supported, it is used as well. If
1920 neither RDRAND nor RDTSC are supported, then randomness is
1921 read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001922
1923 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
Kees Cooka653f352013-11-11 14:28:39 -08001924 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1925 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1926 minimum of 2MiB, only 10 bits of entropy is theoretically
1927 possible. At best, due to page table layouts, 64-bit can use
1928 9 bits of entropy and 32-bit uses 8 bits.
Kees Cook8ab38202013-10-10 17:18:14 -07001929
Kees Cookda2b6fb2013-12-10 12:27:45 -08001930 If unsure, say N.
1931
Kees Cook8ab38202013-10-10 17:18:14 -07001932config RANDOMIZE_BASE_MAX_OFFSET
Kees Cookda2b6fb2013-12-10 12:27:45 -08001933 hex "Maximum kASLR offset allowed" if EXPERT
Kees Cook8ab38202013-10-10 17:18:14 -07001934 depends on RANDOMIZE_BASE
Kees Cook6145cfe2013-10-10 17:18:18 -07001935 range 0x0 0x20000000 if X86_32
1936 default "0x20000000" if X86_32
1937 range 0x0 0x40000000 if X86_64
1938 default "0x40000000" if X86_64
Kees Cook8ab38202013-10-10 17:18:14 -07001939 ---help---
Kees Cookda2b6fb2013-12-10 12:27:45 -08001940 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1941 memory is used to determine the maximal offset in bytes that will
1942 be applied to the kernel when kernel Address Space Layout
1943 Randomization (kASLR) is active. This must be a multiple of
1944 PHYSICAL_ALIGN.
Kees Cook6145cfe2013-10-10 17:18:18 -07001945
Kees Cookda2b6fb2013-12-10 12:27:45 -08001946 On 32-bit this is limited to 512MiB by page table layouts. The
1947 default is 512MiB.
Kees Cook6145cfe2013-10-10 17:18:18 -07001948
Kees Cookda2b6fb2013-12-10 12:27:45 -08001949 On 64-bit this is limited by how the kernel fixmap page table is
1950 positioned, so this cannot be larger than 1GiB currently. Without
1951 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1952 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1953 modules area will shrink to compensate, up to the current maximum
1954 1GiB to 1GiB split. The default is 1GiB.
1955
1956 If unsure, leave at the default value.
Kees Cook8ab38202013-10-10 17:18:14 -07001957
1958# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001959config X86_NEED_RELOCS
1960 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001961 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001962
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001963config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001964 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001965 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001966 range 0x2000 0x1000000 if X86_32
1967 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001968 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001969 This value puts the alignment restrictions on physical address
1970 where kernel is loaded and run from. Kernel is compiled for an
1971 address which meets above alignment restriction.
1972
1973 If bootloader loads the kernel at a non-aligned address and
1974 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1975 address aligned to above value and run from there.
1976
1977 If bootloader loads the kernel at a non-aligned address and
1978 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1979 load address and decompress itself to the address it has been
1980 compiled for and run from there. The address for which kernel is
1981 compiled already meets above alignment restrictions. Hence the
1982 end result is that kernel runs from a physical address meeting
1983 above alignment restrictions.
1984
Kees Cooka0215062013-07-08 09:15:17 -07001985 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1986 this value must be a multiple of 0x200000.
1987
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001988 Don't change this unless you know what you are doing.
1989
1990config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001991 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001992 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001993 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001994 Say Y here to allow turning CPUs off and on. CPUs can be
1995 controlled through /sys/devices/system/cpu.
1996 ( Note: power management support will enable this option
1997 automatically on SMP systems. )
1998 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001999
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002000config BOOTPARAM_HOTPLUG_CPU0
2001 bool "Set default setting of cpu0_hotpluggable"
2002 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002003 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002004 ---help---
2005 Set whether default state of cpu0_hotpluggable is on or off.
2006
2007 Say Y here to enable CPU0 hotplug by default. If this switch
2008 is turned on, there is no need to give cpu0_hotplug kernel
2009 parameter and the CPU0 hotplug feature is enabled by default.
2010
2011 Please note: there are two known CPU0 dependencies if you want
2012 to enable the CPU0 hotplug feature either by this switch or by
2013 cpu0_hotplug kernel parameter.
2014
2015 First, resume from hibernate or suspend always starts from CPU0.
2016 So hibernate and suspend are prevented if CPU0 is offline.
2017
2018 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2019 offline if any interrupt can not migrate out of CPU0. There may
2020 be other CPU0 dependencies.
2021
2022 Please make sure the dependencies are under your control before
2023 you enable this feature.
2024
2025 Say N if you don't want to enable CPU0 hotplug feature by default.
2026 You still can enable the CPU0 hotplug feature at boot by kernel
2027 parameter cpu0_hotplug.
2028
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002029config DEBUG_HOTPLUG_CPU0
2030 def_bool n
2031 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002032 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002033 ---help---
2034 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2035 soon as possible and boots up userspace with CPU0 offlined. User
2036 can online CPU0 back after boot time.
2037
2038 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2039 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2040 compilation or giving cpu0_hotplug kernel parameter at boot.
2041
2042 If unsure, say N.
2043
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002044config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002045 def_bool n
2046 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002047 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002048 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002049 Certain buggy versions of glibc will crash if they are
2050 presented with a 32-bit vDSO that is not mapped at the address
2051 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002052
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002053 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2054 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2055 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2056 the only released version with the bug, but OpenSUSE 9
2057 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002058
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002059 The symptom of the bug is that everything crashes on startup, saying:
2060 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2061
2062 Saying Y here changes the default value of the vdso32 boot
2063 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2064 This works around the glibc bug but hurts performance.
2065
2066 If unsure, say N: if you are compiling your own kernel, you
2067 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002068
Kees Cook3dc33bd2015-08-12 17:55:19 -07002069choice
2070 prompt "vsyscall table for legacy applications"
2071 depends on X86_64
2072 default LEGACY_VSYSCALL_EMULATE
2073 help
2074 Legacy user code that does not know how to find the vDSO expects
2075 to be able to issue three syscalls by calling fixed addresses in
2076 kernel space. Since this location is not randomized with ASLR,
2077 it can be used to assist security vulnerability exploitation.
2078
2079 This setting can be changed at boot time via the kernel command
2080 line parameter vsyscall=[native|emulate|none].
2081
2082 On a system with recent enough glibc (2.14 or newer) and no
2083 static binaries, you can say None without a performance penalty
2084 to improve security.
2085
2086 If unsure, select "Emulate".
2087
2088 config LEGACY_VSYSCALL_NATIVE
2089 bool "Native"
2090 help
2091 Actual executable code is located in the fixed vsyscall
2092 address mapping, implementing time() efficiently. Since
2093 this makes the mapping executable, it can be used during
2094 security vulnerability exploitation (traditionally as
2095 ROP gadgets). This configuration is not recommended.
2096
2097 config LEGACY_VSYSCALL_EMULATE
2098 bool "Emulate"
2099 help
2100 The kernel traps and emulates calls into the fixed
2101 vsyscall address mapping. This makes the mapping
2102 non-executable, but it still contains known contents,
2103 which could be used in certain rare security vulnerability
2104 exploits. This configuration is recommended when userspace
2105 still uses the vsyscall area.
2106
2107 config LEGACY_VSYSCALL_NONE
2108 bool "None"
2109 help
2110 There will be no vsyscall mapping at all. This will
2111 eliminate any risk of ASLR bypass due to the vsyscall
2112 fixed address mapping. Attempts to use the vsyscalls
2113 will be reported to dmesg, so that either old or
2114 malicious userspace programs can be identified.
2115
2116endchoice
2117
Tim Bird516cbf32008-08-12 12:52:36 -07002118config CMDLINE_BOOL
2119 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002120 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002121 Allow for specifying boot arguments to the kernel at
2122 build time. On some systems (e.g. embedded ones), it is
2123 necessary or convenient to provide some or all of the
2124 kernel boot arguments with the kernel itself (that is,
2125 to not rely on the boot loader to provide them.)
2126
2127 To compile command line arguments into the kernel,
2128 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002129 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002130
2131 Systems with fully functional boot loaders (i.e. non-embedded)
2132 should leave this option set to 'N'.
2133
2134config CMDLINE
2135 string "Built-in kernel command string"
2136 depends on CMDLINE_BOOL
2137 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002138 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002139 Enter arguments here that should be compiled into the kernel
2140 image and used at boot time. If the boot loader provides a
2141 command line at boot time, it is appended to this string to
2142 form the full kernel command line, when the system boots.
2143
2144 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2145 change this behavior.
2146
2147 In most cases, the command line (whether built-in or provided
2148 by the boot loader) should specify the device for the root
2149 file system.
2150
2151config CMDLINE_OVERRIDE
2152 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002153 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002154 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002155 Set this option to 'Y' to have the kernel ignore the boot loader
2156 command line, and use ONLY the built-in command line.
2157
2158 This is used to work around broken boot loaders. This should
2159 be set to 'N' under normal conditions.
2160
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002161config MODIFY_LDT_SYSCALL
2162 bool "Enable the LDT (local descriptor table)" if EXPERT
2163 default y
2164 ---help---
2165 Linux can allow user programs to install a per-process x86
2166 Local Descriptor Table (LDT) using the modify_ldt(2) system
2167 call. This is required to run 16-bit or segmented code such as
2168 DOSEMU or some Wine programs. It is also used by some very old
2169 threading libraries.
2170
2171 Enabling this feature adds a small amount of overhead to
2172 context switches and increases the low-level kernel attack
2173 surface. Disabling it removes the modify_ldt(2) system call.
2174
2175 Saying 'N' here may make sense for embedded or server kernels.
2176
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002177source "kernel/livepatch/Kconfig"
2178
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002179endmenu
2180
2181config ARCH_ENABLE_MEMORY_HOTPLUG
2182 def_bool y
2183 depends on X86_64 || (X86_32 && HIGHMEM)
2184
Gary Hade35551052008-10-31 10:52:03 -07002185config ARCH_ENABLE_MEMORY_HOTREMOVE
2186 def_bool y
2187 depends on MEMORY_HOTPLUG
2188
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002189config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002190 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002191 depends on NUMA
2192
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002193config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2194 def_bool y
2195 depends on X86_64 || X86_PAE
2196
Naoya Horiguchic177c812014-06-04 16:05:35 -07002197config ARCH_ENABLE_HUGEPAGE_MIGRATION
2198 def_bool y
2199 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2200
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002201menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002202
2203config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002204 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002205 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002206
2207source "kernel/power/Kconfig"
2208
2209source "drivers/acpi/Kconfig"
2210
Feng Tangefafc8b2009-08-14 15:23:29 -04002211source "drivers/sfi/Kconfig"
2212
Andi Kleena6b68072008-01-30 13:32:49 +01002213config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002214 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002215 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002216
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002217menuconfig APM
2218 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002219 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002220 ---help---
2221 APM is a BIOS specification for saving power using several different
2222 techniques. This is mostly useful for battery powered laptops with
2223 APM compliant BIOSes. If you say Y here, the system time will be
2224 reset after a RESUME operation, the /proc/apm device will provide
2225 battery status information, and user-space programs will receive
2226 notification of APM "events" (e.g. battery status change).
2227
2228 If you select "Y" here, you can disable actual use of the APM
2229 BIOS by passing the "apm=off" option to the kernel at boot time.
2230
2231 Note that the APM support is almost completely disabled for
2232 machines with more than one CPU.
2233
2234 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002235 and more information, read <file:Documentation/power/apm-acpi.txt>
2236 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002237 <http://www.tldp.org/docs.html#howto>.
2238
2239 This driver does not spin down disk drives (see the hdparm(8)
2240 manpage ("man 8 hdparm") for that), and it doesn't turn off
2241 VESA-compliant "green" monitors.
2242
2243 This driver does not support the TI 4000M TravelMate and the ACER
2244 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2245 desktop machines also don't have compliant BIOSes, and this driver
2246 may cause those machines to panic during the boot phase.
2247
2248 Generally, if you don't have a battery in your machine, there isn't
2249 much point in using this driver and you should say N. If you get
2250 random kernel OOPSes or reboots that don't seem to be related to
2251 anything, try disabling/enabling this option (or disabling/enabling
2252 APM in your BIOS).
2253
2254 Some other things you should try when experiencing seemingly random,
2255 "weird" problems:
2256
2257 1) make sure that you have enough swap space and that it is
2258 enabled.
2259 2) pass the "no-hlt" option to the kernel
2260 3) switch on floating point emulation in the kernel and pass
2261 the "no387" option to the kernel
2262 4) pass the "floppy=nodma" option to the kernel
2263 5) pass the "mem=4M" option to the kernel (thereby disabling
2264 all but the first 4 MB of RAM)
2265 6) make sure that the CPU is not over clocked.
2266 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2267 8) disable the cache from your BIOS settings
2268 9) install a fan for the video card or exchange video RAM
2269 10) install a better fan for the CPU
2270 11) exchange RAM chips
2271 12) exchange the motherboard.
2272
2273 To compile this driver as a module, choose M here: the
2274 module will be called apm.
2275
2276if APM
2277
2278config APM_IGNORE_USER_SUSPEND
2279 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002280 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002281 This option will ignore USER SUSPEND requests. On machines with a
2282 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2283 series notebooks, it is necessary to say Y because of a BIOS bug.
2284
2285config APM_DO_ENABLE
2286 bool "Enable PM at boot time"
2287 ---help---
2288 Enable APM features at boot time. From page 36 of the APM BIOS
2289 specification: "When disabled, the APM BIOS does not automatically
2290 power manage devices, enter the Standby State, enter the Suspend
2291 State, or take power saving steps in response to CPU Idle calls."
2292 This driver will make CPU Idle calls when Linux is idle (unless this
2293 feature is turned off -- see "Do CPU IDLE calls", below). This
2294 should always save battery power, but more complicated APM features
2295 will be dependent on your BIOS implementation. You may need to turn
2296 this option off if your computer hangs at boot time when using APM
2297 support, or if it beeps continuously instead of suspending. Turn
2298 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2299 T400CDT. This is off by default since most machines do fine without
2300 this feature.
2301
2302config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002303 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002304 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002305 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002306 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2307 On some machines, this can activate improved power savings, such as
2308 a slowed CPU clock rate, when the machine is idle. These idle calls
2309 are made after the idle loop has run for some length of time (e.g.,
2310 333 mS). On some machines, this will cause a hang at boot time or
2311 whenever the CPU becomes idle. (On machines with more than one CPU,
2312 this option does nothing.)
2313
2314config APM_DISPLAY_BLANK
2315 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002316 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002317 Enable console blanking using the APM. Some laptops can use this to
2318 turn off the LCD backlight when the screen blanker of the Linux
2319 virtual console blanks the screen. Note that this is only used by
2320 the virtual console screen blanker, and won't turn off the backlight
2321 when using the X Window system. This also doesn't have anything to
2322 do with your VESA-compliant power-saving monitor. Further, this
2323 option doesn't work for all laptops -- it might not turn off your
2324 backlight at all, or it might print a lot of errors to the console,
2325 especially if you are using gpm.
2326
2327config APM_ALLOW_INTS
2328 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002329 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002330 Normally we disable external interrupts while we are making calls to
2331 the APM BIOS as a measure to lessen the effects of a badly behaving
2332 BIOS implementation. The BIOS should reenable interrupts if it
2333 needs to. Unfortunately, some BIOSes do not -- especially those in
2334 many of the newer IBM Thinkpads. If you experience hangs when you
2335 suspend, try setting this to Y. Otherwise, say N.
2336
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002337endif # APM
2338
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002339source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002340
2341source "drivers/cpuidle/Kconfig"
2342
Andy Henroid27471fd2008-10-09 11:45:22 -07002343source "drivers/idle/Kconfig"
2344
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002345endmenu
2346
2347
2348menu "Bus options (PCI etc.)"
2349
2350config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002351 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002352 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002353 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002354 Find out whether you have a PCI motherboard. PCI is the name of a
2355 bus system, i.e. the way the CPU talks to the other stuff inside
2356 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2357 VESA. If you have PCI, say Y, otherwise N.
2358
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002359choice
2360 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002361 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002362 default PCI_GOANY
2363 ---help---
2364 On PCI systems, the BIOS can be used to detect the PCI devices and
2365 determine their configuration. However, some old PCI motherboards
2366 have BIOS bugs and may crash if this is done. Also, some embedded
2367 PCI-based systems don't have any BIOS at all. Linux can also try to
2368 detect the PCI hardware directly without using the BIOS.
2369
2370 With this option, you can specify how Linux should detect the
2371 PCI devices. If you choose "BIOS", the BIOS will be used,
2372 if you choose "Direct", the BIOS won't be used, and if you
2373 choose "MMConfig", then PCI Express MMCONFIG will be used.
2374 If you choose "Any", the kernel will try MMCONFIG, then the
2375 direct access method and falls back to the BIOS if that doesn't
2376 work. If unsure, go with the default, which is "Any".
2377
2378config PCI_GOBIOS
2379 bool "BIOS"
2380
2381config PCI_GOMMCONFIG
2382 bool "MMConfig"
2383
2384config PCI_GODIRECT
2385 bool "Direct"
2386
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002387config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002388 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002389 depends on OLPC
2390
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002391config PCI_GOANY
2392 bool "Any"
2393
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002394endchoice
2395
2396config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002397 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002398 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002399
2400# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2401config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002402 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002403 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002404
2405config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002406 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002407 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002408
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002409config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002410 def_bool y
2411 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002412
Alex Nixonb5401a92010-03-18 16:31:34 -04002413config PCI_XEN
2414 def_bool y
2415 depends on PCI && XEN
2416 select SWIOTLB_XEN
2417
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002418config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002419 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002420 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002421
2422config PCI_MMCONFIG
2423 bool "Support mmconfig PCI config space access"
2424 depends on X86_64 && PCI && ACPI
2425
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002426config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002427 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002428 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002429 help
2430 Read the PCI windows out of the CNB20LE host bridge. This allows
2431 PCI hotplug to work on systems with the CNB20LE chipset which do
2432 not have ACPI.
2433
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002434 There's no public spec for this chipset, and this functionality
2435 is known to be incomplete.
2436
2437 You should say N unless you know you need this.
2438
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002439source "drivers/pci/pcie/Kconfig"
2440
2441source "drivers/pci/Kconfig"
2442
David Rientjes1c00f012011-03-22 16:34:59 -07002443# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002444config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002445 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2446 default y
2447 help
2448 Enables ISA-style DMA support for devices requiring such controllers.
2449 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002450
2451if X86_32
2452
2453config ISA
2454 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002455 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002456 Find out whether you have ISA slots on your motherboard. ISA is the
2457 name of a bus system, i.e. the way the CPU talks to the other stuff
2458 inside your box. Other bus systems are PCI, EISA, MicroChannel
2459 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2460 newer boards don't support it. If you have ISA, say Y, otherwise N.
2461
2462config EISA
2463 bool "EISA support"
2464 depends on ISA
2465 ---help---
2466 The Extended Industry Standard Architecture (EISA) bus was
2467 developed as an open alternative to the IBM MicroChannel bus.
2468
2469 The EISA bus provided some of the features of the IBM MicroChannel
2470 bus while maintaining backward compatibility with cards made for
2471 the older ISA bus. The EISA bus saw limited use between 1988 and
2472 1995 when it was made obsolete by the PCI bus.
2473
2474 Say Y here if you are building a kernel for an EISA-based machine.
2475
2476 Otherwise, say N.
2477
2478source "drivers/eisa/Kconfig"
2479
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002480config SCx200
2481 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002482 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002483 This provides basic support for National Semiconductor's
2484 (now AMD's) Geode processors. The driver probes for the
2485 PCI-IDs of several on-chip devices, so its a good dependency
2486 for other scx200_* drivers.
2487
2488 If compiled as a module, the driver is named scx200.
2489
2490config SCx200HR_TIMER
2491 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002492 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002494 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002495 This driver provides a clocksource built upon the on-chip
2496 27MHz high-resolution timer. Its also a workaround for
2497 NSC Geode SC-1100's buggy TSC, which loses time when the
2498 processor goes idle (as is done by the scheduler). The
2499 other workaround is idle=poll boot option.
2500
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002501config OLPC
2502 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002503 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002504 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002505 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002506 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002507 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002508 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002509 Add support for detecting the unique features of the OLPC
2510 XO hardware.
2511
Daniel Drakea3128582011-06-25 17:34:10 +01002512config OLPC_XO1_PM
2513 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002514 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002515 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002516 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002517 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002518
Daniel Drakecfee9592011-06-25 17:34:17 +01002519config OLPC_XO1_RTC
2520 bool "OLPC XO-1 Real Time Clock"
2521 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2522 ---help---
2523 Add support for the XO-1 real time clock, which can be used as a
2524 programmable wakeup source.
2525
Daniel Drake7feda8e2011-06-25 17:34:12 +01002526config OLPC_XO1_SCI
2527 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002528 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002529 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002530 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002531 select GPIO_CS5535
2532 select MFD_CORE
2533 ---help---
2534 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002535 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002536 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002537 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002538 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002539 - AC adapter status updates
2540 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002541
Daniel Drakea0f30f52011-06-25 17:34:18 +01002542config OLPC_XO15_SCI
2543 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002544 depends on OLPC && ACPI
2545 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002546 ---help---
2547 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2548 - EC-driven system wakeups
2549 - AC adapter status updates
2550 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002551
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002552config ALIX
2553 bool "PCEngines ALIX System Support (LED setup)"
2554 select GPIOLIB
2555 ---help---
2556 This option enables system support for the PCEngines ALIX.
2557 At present this just sets up LEDs for GPIO control on
2558 ALIX2/3/6 boards. However, other system specific setup should
2559 get added here.
2560
2561 Note: You must still enable the drivers for GPIO and LED support
2562 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2563
2564 Note: You have to set alix.force=1 for boards with Award BIOS.
2565
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002566config NET5501
2567 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2568 select GPIOLIB
2569 ---help---
2570 This option enables system support for the Soekris Engineering net5501.
2571
Philip A. Prindeville31970592012-01-14 01:45:39 -07002572config GEOS
2573 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2574 select GPIOLIB
2575 depends on DMI
2576 ---help---
2577 This option enables system support for the Traverse Technologies GEOS.
2578
Vivien Didelot7d029122013-01-04 16:18:14 -05002579config TS5500
2580 bool "Technologic Systems TS-5500 platform support"
2581 depends on MELAN
2582 select CHECK_SIGNATURE
2583 select NEW_LEDS
2584 select LEDS_CLASS
2585 ---help---
2586 This option enables system support for the Technologic Systems TS-5500.
2587
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002588endif # X86_32
2589
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002590config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002592 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002593
2594source "drivers/pcmcia/Kconfig"
2595
2596source "drivers/pci/hotplug/Kconfig"
2597
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002598config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002599 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002600 depends on PCI
2601 default n
2602 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002603 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002604 infrastructure code to support RapidIO interconnect devices.
2605
2606source "drivers/rapidio/Kconfig"
2607
David Herrmanne3263ab2013-08-02 14:05:22 +02002608config X86_SYSFB
2609 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2610 help
2611 Firmwares often provide initial graphics framebuffers so the BIOS,
2612 bootloader or kernel can show basic video-output during boot for
2613 user-guidance and debugging. Historically, x86 used the VESA BIOS
2614 Extensions and EFI-framebuffers for this, which are mostly limited
2615 to x86.
2616 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2617 framebuffers so the new generic system-framebuffer drivers can be
2618 used on x86. If the framebuffer is not compatible with the generic
2619 modes, it is adverticed as fallback platform framebuffer so legacy
2620 drivers like efifb, vesafb and uvesafb can pick it up.
2621 If this option is not selected, all system framebuffers are always
2622 marked as fallback platform framebuffers as usual.
2623
2624 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2625 not be able to pick up generic system framebuffers if this option
2626 is selected. You are highly encouraged to enable simplefb as
2627 replacement if you select this option. simplefb can correctly deal
2628 with generic system framebuffers. But you should still keep vesafb
2629 and others enabled as fallback if a system framebuffer is
2630 incompatible with simplefb.
2631
2632 If unsure, say Y.
2633
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002634endmenu
2635
2636
2637menu "Executable file formats / Emulations"
2638
2639source "fs/Kconfig.binfmt"
2640
2641config IA32_EMULATION
2642 bool "IA32 Emulation"
2643 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002644 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002645 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002646 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002647 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002648 Include code to run legacy 32-bit programs under a
2649 64-bit kernel. You should likely turn this on, unless you're
2650 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002651
2652config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002653 tristate "IA32 a.out support"
2654 depends on IA32_EMULATION
2655 ---help---
2656 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002657
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002658config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002659 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002660 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002661 ---help---
2662 Include code to run binaries for the x32 native 32-bit ABI
2663 for 64-bit processors. An x32 process gets access to the
2664 full 64-bit register file and wide data path while leaving
2665 pointers at 32 bits for smaller memory footprint.
2666
2667 You will need a recent binutils (2.22 or later) with
2668 elf32_x86_64 support enabled to compile a kernel with this
2669 option set.
2670
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002671config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002672 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002673 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002674
Jan Beulich3120e252012-09-10 12:41:45 +01002675if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002676config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002677 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002678
2679config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002680 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002681 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002682
David Howellsee009e4a02011-03-07 15:06:20 +00002683config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002684 def_bool y
2685 depends on KEYS
2686endif
David Howellsee009e4a02011-03-07 15:06:20 +00002687
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002688endmenu
2689
2690
Keith Packarde5beae12008-11-03 18:21:45 +01002691config HAVE_ATOMIC_IOMAP
2692 def_bool y
2693 depends on X86_32
2694
Alessandro Rubini4692d772012-04-04 19:39:58 +02002695config X86_DEV_DMA_OPS
2696 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002697 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002698
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002699config X86_DMA_REMAP
2700 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002701 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002702
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002703config PMC_ATOM
2704 def_bool y
2705 depends on PCI
2706
Keith Busch185a3832016-01-12 13:18:10 -07002707config VMD
2708 depends on PCI_MSI
2709 tristate "Volume Management Device Driver"
2710 default N
2711 ---help---
2712 Adds support for the Intel Volume Management Device (VMD). VMD is a
2713 secondary PCI host bridge that allows PCI Express root ports,
2714 and devices attached to them, to be removed from the default
2715 PCI domain and placed within the VMD domain. This provides
2716 more bus resources than are otherwise possible with a
2717 single domain. If you know your system provides one of these and
2718 has devices attached to it, say Y; if you are not sure, say N.
2719
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002720source "net/Kconfig"
2721
2722source "drivers/Kconfig"
2723
2724source "drivers/firmware/Kconfig"
2725
2726source "fs/Kconfig"
2727
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728source "arch/x86/Kconfig.debug"
2729
2730source "security/Kconfig"
2731
2732source "crypto/Kconfig"
2733
Avi Kivityedf88412007-12-16 11:02:48 +02002734source "arch/x86/kvm/Kconfig"
2735
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002736source "lib/Kconfig"