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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001# SPDX-License-Identifier: GPL-2.0
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01002# Select 32 or 64 bit
3config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01004 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00005 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01006 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01007 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010011 def_bool y
12 depends on !64BIT
Ingo Molnar341c7872016-11-15 10:04:55 +010013 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010021
22config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010023 def_bool y
24 depends on 64BIT
Ingo Molnard94e0682016-11-15 10:11:57 +010025 # Options that are inherently 64-bit kernel only:
Aneesh Kumar K.Ve1073d12017-07-06 15:39:17 -070026 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
Ingo Molnard94e0682016-11-15 10:11:57 +010027 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
31 select X86_DEV_DMA_OPS
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010032
Ingo Molnard94e0682016-11-15 10:11:57 +010033#
34# Arch settings
35#
36# ( Note that options that are marked 'if X86_64' could in principle be
37# ported to 32-bit as well. )
38#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010039config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010040 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010041 #
42 # Note: keep this list sorted alphabetically
43 #
Ingo Molnar6471b822015-06-03 10:00:13 +020044 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
46 select ANON_INODES
47 select ARCH_CLOCKSOURCE_DATA
48 select ARCH_DISCARD_MEMBLOCK
Ingo Molnarc763ea22016-11-15 10:26:39 +010049 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080050 select ARCH_HAS_DEBUG_VIRTUAL
Dan Williams21266be2015-11-19 18:19:29 -080051 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020052 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070053 select ARCH_HAS_FAST_MULTIPLIER
Daniel Micay6974f0c2017-07-12 14:36:10 -070054 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080055 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070056 select ARCH_HAS_KCOV if X86_64
Christoph Hellwigea8c64a2018-01-10 16:21:13 +010057 select ARCH_HAS_PHYS_TO_DMA
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050058 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Ingo Molnarc763ea22016-11-15 10:26:39 +010059 select ARCH_HAS_PMEM_API if X86_64
Kees Cook39208aa2017-09-02 13:09:46 -070060 select ARCH_HAS_REFCOUNT
Dan Williams0aed55a2017-05-29 12:22:50 -070061 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Daniel Borkmannd2852a22017-02-21 16:09:33 +010062 select ARCH_HAS_SET_MEMORY
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select ARCH_HAS_SG_CHAIN
Laura Abbottad21fc42017-02-06 16:31:57 -080064 select ARCH_HAS_STRICT_KERNEL_RWX
65 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050066 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Andrey Ryabininc6d30852016-01-20 15:00:55 -080067 select ARCH_HAS_UBSAN_SANITIZE_ALL
Oliver O'Halloran65f7d042017-06-28 11:32:31 +100068 select ARCH_HAS_ZONE_DEVICE if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020069 select ARCH_HAVE_NMI_SAFE_CMPXCHG
70 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040071 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080072 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020073 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020074 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
75 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020076 select ARCH_USE_QUEUED_RWLOCKS
77 select ARCH_USE_QUEUED_SPINLOCKS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070078 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Ingo Molnarc763ea22016-11-15 10:26:39 +010079 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Huang Ying38d8b4e2017-07-06 15:37:18 -070080 select ARCH_WANTS_THP_SWAP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020081 select BUILDTIME_EXTABLE_SORT
82 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +020083 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
84 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +020085 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070086 select EDAC_ATOMIC_SCRUB
87 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020088 select GENERIC_CLOCKEVENTS
89 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
90 select GENERIC_CLOCKEVENTS_MIN_ADJUST
91 select GENERIC_CMOS_UPDATE
92 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +010093 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select GENERIC_EARLY_IOREMAP
95 select GENERIC_FIND_FIRST_BIT
96 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +020097 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +020098 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +020099 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200101 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select GENERIC_IRQ_SHOW
103 select GENERIC_PENDING_IRQ if SMP
104 select GENERIC_SMP_IDLE_THREAD
105 select GENERIC_STRNCPY_FROM_USER
106 select GENERIC_STRNLEN_USER
107 select GENERIC_TIME_VSYSCALL
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200108 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200109 select HAVE_ACPI_APEI if ACPI
110 select HAVE_ACPI_APEI_NMI if ACPI
111 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200112 select HAVE_ARCH_AUDITSYSCALL
113 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
114 select HAVE_ARCH_JUMP_LABEL
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800115 select HAVE_ARCH_KASAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200116 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800117 select HAVE_ARCH_MMAP_RND_BITS if MMU
118 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300119 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +0200120 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700121 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Ingo Molnar6471b822015-06-03 10:00:13 +0200122 select HAVE_ARCH_TRACEHOOK
123 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800124 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700125 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100126 select HAVE_ARCH_WITHIN_STACK_FRAMES
Ingo Molnar6471b822015-06-03 10:00:13 +0200127 select HAVE_CC_STACKPROTECTOR
128 select HAVE_CMPXCHG_DOUBLE
129 select HAVE_CMPXCHG_LOCAL
130 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700131 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200132 select HAVE_C_RECORDMCOUNT
133 select HAVE_DEBUG_KMEMLEAK
134 select HAVE_DEBUG_STACKOVERFLOW
135 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700136 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400137 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900138 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Ingo Molnarc763ea22016-11-15 10:26:39 +0100139 select HAVE_EBPF_JIT if X86_64
Johannes Berg58340a02008-07-25 01:45:33 -0700140 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700141 select HAVE_EXIT_THREAD
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400142 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200143 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_FUNCTION_GRAPH_TRACER
145 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200146 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530147 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200148 select HAVE_IDE
149 select HAVE_IOREMAP_PROT
150 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
151 select HAVE_IRQ_TIME_ACCOUNTING
152 select HAVE_KERNEL_BZIP2
153 select HAVE_KERNEL_GZIP
154 select HAVE_KERNEL_LZ4
155 select HAVE_KERNEL_LZMA
156 select HAVE_KERNEL_LZO
157 select HAVE_KERNEL_XZ
158 select HAVE_KPROBES
159 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900160 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200161 select HAVE_KRETPROBES
162 select HAVE_KVM
163 select HAVE_LIVEPATCH if X86_64
164 select HAVE_MEMBLOCK
165 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200166 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500167 select HAVE_MOD_ARCH_SPECIFIC
Petr Mladek42a0bb32016-05-20 17:00:33 -0700168 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200169 select HAVE_OPROFILE
170 select HAVE_OPTPROBES
171 select HAVE_PCSPKR_PLATFORM
172 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200173 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700174 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200175 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200176 select HAVE_PERF_USER_STACK_DUMP
Vitaly Kuznetsov9e52fc22017-08-28 10:22:51 +0200177 select HAVE_RCU_TABLE_FREE
Ingo Molnar6471b822015-06-03 10:00:13 +0200178 select HAVE_REGS_AND_STACK_ACCESS_API
Josh Poimboeuf11af8472017-10-13 15:02:00 -0500179 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
Ingo Molnarc763ea22016-11-15 10:26:39 +0100180 select HAVE_STACK_VALIDATION if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200181 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200182 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300183 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100184 select IRQ_FORCED_THREADING
Thomas Gleixnerdf65c1b2017-03-16 22:50:07 +0100185 select PCI_LOCKLESS_CONFIG
Ingo Molnar6471b822015-06-03 10:00:13 +0200186 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500187 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200188 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200189 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500190 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200191 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700192 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200193 select USER_STACKTRACE_SUPPORT
194 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200195 select X86_FEATURE_NAMES if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530196
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200197config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100198 def_bool y
199 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200200
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700201config OUTPUT_FORMAT
202 string
203 default "elf32-i386" if X86_32
204 default "elf64-x86-64" if X86_64
205
Sam Ravnborg73531902008-05-25 23:03:18 +0200206config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200207 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200208 default "arch/x86/configs/i386_defconfig" if X86_32
209 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200210
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100211config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100212 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100213
214config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100215 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100216
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100217config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100218 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100219
Daniel Cashman9e08f572016-01-14 15:20:06 -0800220config ARCH_MMAP_RND_BITS_MIN
221 default 28 if 64BIT
222 default 8
223
224config ARCH_MMAP_RND_BITS_MAX
225 default 32 if 64BIT
226 default 16
227
228config ARCH_MMAP_RND_COMPAT_BITS_MIN
229 default 8
230
231config ARCH_MMAP_RND_COMPAT_BITS_MAX
232 default 16
233
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100234config SBUS
235 bool
236
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800237config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100238 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400239 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800240
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700241config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700242 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700243
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100244config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100245 def_bool y
246 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100247
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100248config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100249 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100250 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000251 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
252
253config GENERIC_BUG_RELATIVE_POINTERS
254 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100255
256config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100257 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100258
259config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100260 def_bool y
261 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100262
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100263config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100264 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100265
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100266config GENERIC_CALIBRATE_DELAY
267 def_bool y
268
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800269config ARCH_HAS_CPU_RELAX
270 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100271
Pekka Enberg1b27d052008-04-28 02:12:22 -0700272config ARCH_HAS_CACHE_LINE_SIZE
273 def_bool y
274
Mike Travisdd5af902008-01-30 13:33:32 +0100275config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900276 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100277
Tejun Heo08fc4582009-08-14 15:00:49 +0900278config NEED_PER_CPU_EMBED_FIRST_CHUNK
279 def_bool y
280
281config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900282 def_bool y
283
Johannes Berg801e4062007-12-08 02:12:39 +0100284config ARCH_HIBERNATION_POSSIBLE
285 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100286
Johannes Bergf4cb5702007-12-08 02:14:00 +0100287config ARCH_SUSPEND_POSSIBLE
288 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100289
Steve Cappercfe28c52013-04-29 14:29:48 +0100290config ARCH_WANT_HUGE_PMD_SHARE
291 def_bool y
292
Steve Capper53313b22013-04-30 08:03:42 +0100293config ARCH_WANT_GENERAL_HUGETLB
294 def_bool y
295
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100296config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000297 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100298
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100299config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000300 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100301
Ingo Molnar765c68b2008-04-09 11:03:37 +0200302config ARCH_SUPPORTS_OPTIMIZED_INLINING
303 def_bool y
304
Akinobu Mita6a11f752009-03-31 15:23:17 -0700305config ARCH_SUPPORTS_DEBUG_PAGEALLOC
306 def_bool y
307
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300308config KASAN_SHADOW_OFFSET
309 hex
310 depends on KASAN
311 default 0xdffffc0000000000
312
Shane Wang69575d32009-09-01 18:25:07 -0700313config HAVE_INTEL_TXT
314 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700315 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700316
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100317config X86_32_SMP
318 def_bool y
319 depends on X86_32 && SMP
320
321config X86_64_SMP
322 def_bool y
323 depends on X86_64 && SMP
324
Tejun Heoccbeed32009-02-09 22:17:40 +0900325config X86_32_LAZY_GS
326 def_bool y
Kees Cook2bc2f682018-02-06 15:37:41 -0800327 depends on X86_32 && CC_STACKPROTECTOR_NONE
Tejun Heoccbeed32009-02-09 22:17:40 +0900328
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530329config ARCH_SUPPORTS_UPROBES
330 def_bool y
331
Rob Herringd20642f2014-04-18 17:19:54 -0500332config FIX_EARLYCON_MEM
333 def_bool y
334
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700335config PGTABLE_LEVELS
336 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300337 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700338 default 4 if X86_64
339 default 3 if X86_PAE
340 default 2
341
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100342source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700343source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100344
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100345menu "Processor type and features"
346
Randy Dunlap5ee71532012-01-16 11:57:18 -0800347config ZONE_DMA
348 bool "DMA memory allocation support" if EXPERT
349 default y
350 help
351 DMA memory allocation support allows devices with less than 32-bit
352 addressing to allocate within the first 16MB of address space.
353 Disable if no such devices will be used.
354
355 If unsure, say Y.
356
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100357config SMP
358 bool "Symmetric multi-processing support"
359 ---help---
360 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800361 a system with only one CPU, say N. If you have a system with more
362 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100363
Robert Graffham4a474152014-01-23 15:55:29 -0800364 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100365 machines, but will use only one CPU of a multiprocessor machine. If
366 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800367 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100368 will run faster if you say N here.
369
370 Note that if you say Y here and choose architecture "586" or
371 "Pentium" under "Processor family", the kernel will not work on 486
372 architectures. Similarly, multiprocessor kernels for the "PPro"
373 architecture may not work on all Pentium based boards.
374
375 People using multiprocessor machines who say Y here should also say
376 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
377 Management" code will be disabled if you say Y here.
378
Paul Bolle395cf962011-08-15 02:02:26 +0200379 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Benjamin Petersonc9525a32017-05-20 17:20:16 -0700380 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100381 <http://www.tldp.org/docs.html#howto>.
382
383 If you don't know what to do here, say N.
384
Josh Triplett9def39be2013-10-30 08:09:45 -0700385config X86_FEATURE_NAMES
386 bool "Processor feature human-readable names" if EMBEDDED
387 default y
388 ---help---
389 This option compiles in a table of x86 feature bits and corresponding
390 names. This is required to support /proc/cpuinfo and a few kernel
391 messages. You can disable this to save space, at the expense of
392 making those few kernel messages show numeric feature bits instead.
393
394 If in doubt, say Y.
395
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100396config X86_FAST_FEATURE_TESTS
397 bool "Fast CPU feature tests" if EMBEDDED
398 default y
399 ---help---
400 Some fast-paths in the kernel depend on the capabilities of the CPU.
401 Say Y here for the kernel to patch in the appropriate code at runtime
402 based on the capabilities of the CPU. The infrastructure for patching
403 code at runtime takes up some additional space; space-constrained
404 embedded systems may wish to say N here to produce smaller, slightly
405 slower code.
406
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800407config X86_X2APIC
408 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200409 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800410 ---help---
411 This enables x2apic support on CPUs that have this feature.
412
413 This allows 32-bit apic IDs (so it can support very large systems),
414 and accesses the local apic via MSRs not via mmio.
415
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800416 If you don't know what to do here, say N.
417
Yinghai Lu6695c852008-06-19 12:13:09 -0700418config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700419 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000420 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200421 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100422 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700423 For old smp systems that do not have proper acpi support. Newer systems
424 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700425
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000426config GOLDFISH
427 def_bool y
428 depends on X86_GOLDFISH
429
David Woodhouse76b04382018-01-11 21:46:25 +0000430config RETPOLINE
431 bool "Avoid speculative indirect branches in kernel"
432 default y
433 help
434 Compile kernel with the retpoline compiler options to guard against
435 kernel-to-user data leaks by avoiding speculative indirect
436 branches. Requires a compiler with -mindirect-branch=thunk-extern
437 support for full protection. The kernel may run slower.
438
439 Without compiler support, at least indirect branches in assembler
440 code are eliminated. Since this includes the syscall entry path,
441 it is not entirely pointless.
442
Vikas Shivappaf01d7d512017-07-25 14:14:22 -0700443config INTEL_RDT
444 bool "Intel Resource Director Technology support"
Fenghua Yu78e99b42016-10-22 06:19:53 -0700445 default n
446 depends on X86 && CPU_SUP_INTEL
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100447 select KERNFS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700448 help
Vikas Shivappaf01d7d512017-07-25 14:14:22 -0700449 Select to enable resource allocation and monitoring which are
450 sub-features of Intel Resource Director Technology(RDT). More
451 information about RDT can be found in the Intel x86
452 Architecture Software Developer Manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700453
454 Say N if unsure.
455
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800456if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800457config X86_BIGSMP
458 bool "Support for big SMP systems with more than 8 CPUs"
459 depends on SMP
460 ---help---
461 This option is needed for the systems that have more than 8 CPUs
462
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800463config X86_EXTENDED_PLATFORM
464 bool "Support for extended (non-PC) x86 platforms"
465 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100466 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100467 If you disable this option then the kernel will only support
468 standard PC platforms. (which covers the vast majority of
469 systems out there.)
470
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800471 If you enable this option then you'll be able to select support
472 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100473 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800474 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800475 RDC R-321x SoC
476 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200477 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200478 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100479
480 If you have one of these systems, or if you want to build a
481 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800482endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100483
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800484if X86_64
485config X86_EXTENDED_PLATFORM
486 bool "Support for extended (non-PC) x86 platforms"
487 default y
488 ---help---
489 If you disable this option then the kernel will only support
490 standard PC platforms. (which covers the vast majority of
491 systems out there.)
492
493 If you enable this option then you'll be able to select support
494 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800495 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800496 ScaleMP vSMP
497 SGI Ultraviolet
498
499 If you have one of these systems, or if you want to build a
500 generic distribution kernel, say Y here - otherwise say N.
501endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800502# This is an alphabetically sorted list of 64 bit extended platforms
503# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800504config X86_NUMACHIP
505 bool "Numascale NumaChip"
506 depends on X86_64
507 depends on X86_EXTENDED_PLATFORM
508 depends on NUMA
509 depends on SMP
510 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700511 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800512 ---help---
513 Adds support for Numascale NumaChip large-SMP systems. Needed to
514 enable more than ~168 cores.
515 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100516
Ingo Molnar6a485652009-01-27 18:29:13 +0100517config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800518 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100519 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100520 select PARAVIRT
521 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800522 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300523 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100524 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100525 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
526 supposed to run on these EM64T-based machines. Only choose this option
527 if you have one of these machines.
528
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800529config X86_UV
530 bool "SGI Ultraviolet"
531 depends on X86_64
532 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500533 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800534 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700535 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200536 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800537 ---help---
538 This option is needed in order to support SGI Ultraviolet systems.
539 If you don't have one of these, you should say N here.
540
541# Following is an alphabetically sorted list of 32 bit extended platforms
542# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100543
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000544config X86_GOLDFISH
545 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100546 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000547 ---help---
548 Enable support for the Goldfish virtual platform used primarily
549 for Android development. Unless you are building for the Android
550 Goldfish emulator say N here.
551
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800552config X86_INTEL_CE
553 bool "CE4100 TV platform"
554 depends on PCI
555 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800556 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800557 depends on X86_32
558 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800559 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100560 select OF
561 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800562 ---help---
563 Select for the Intel CE media processor (CE4100) SOC.
564 This option compiles in support for the CE4100 SOC for settop
565 boxes and media devices.
566
David Cohen4cb9b002013-12-16 17:37:26 -0800567config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100568 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100569 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800570 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000571 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200572 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000573 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000574 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800575 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000576 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000577 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000578 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000579 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000580 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800581 Select to build a kernel capable of supporting Intel MID (Mobile
582 Internet Device) platform systems which do not have the PCI legacy
583 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000584
David Cohen4cb9b002013-12-16 17:37:26 -0800585 Intel MID platforms are based on an Intel processor and chipset which
586 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100587
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000588config X86_INTEL_QUARK
589 bool "Intel Quark platform support"
590 depends on X86_32
591 depends on X86_EXTENDED_PLATFORM
592 depends on X86_PLATFORM_DEVICES
593 depends on X86_TSC
594 depends on PCI
595 depends on PCI_GOANY
596 depends on X86_IO_APIC
597 select IOSF_MBI
598 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200599 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000600 ---help---
601 Select to include support for Quark X1000 SoC.
602 Say Y here if you have a Quark based system such as the Arduino
603 compatible Intel Galileo.
604
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000605config X86_INTEL_LPSS
606 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100607 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000608 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300609 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100610 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000611 ---help---
612 Select to build support for Intel Low Power Subsystem such as
613 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300614 things like clock tree (common clock framework) and pincontrol
615 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000616
Ken Xue92082a82015-02-06 08:27:51 +0800617config X86_AMD_PLATFORM_DEVICE
618 bool "AMD ACPI2Platform devices support"
619 depends on ACPI
620 select COMMON_CLK
621 select PINCTRL
622 ---help---
623 Select to interpret AMD specific ACPI device to platform device
624 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
625 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
626 implemented under PINCTRL subsystem.
627
David E. Boxced3ce72014-09-17 22:13:50 -0700628config IOSF_MBI
629 tristate "Intel SoC IOSF Sideband support for SoC platforms"
630 depends on PCI
631 ---help---
632 This option enables sideband register access support for Intel SoC
633 platforms. On these platforms the IOSF sideband is used in lieu of
634 MSR's for some register accesses, mostly but not limited to thermal
635 and power. Drivers may query the availability of this device to
636 determine if they need the sideband in order to work on these
637 platforms. The sideband is available on the following SoC products.
638 This list is not meant to be exclusive.
639 - BayTrail
640 - Braswell
641 - Quark
642
643 You should say Y if you are running a kernel on one of these SoC's.
644
David E. Boxed2226b2014-09-17 22:13:51 -0700645config IOSF_MBI_DEBUG
646 bool "Enable IOSF sideband access through debugfs"
647 depends on IOSF_MBI && DEBUG_FS
648 ---help---
649 Select this option to expose the IOSF sideband access registers (MCR,
650 MDR, MCRX) through debugfs to write and read register information from
651 different units on the SoC. This is most useful for obtaining device
652 state information for debug and analysis. As this is a general access
653 mechanism, users of this option would have specific knowledge of the
654 device they want to access.
655
656 If you don't require the option or are in doubt, say N.
657
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800658config X86_RDC321X
659 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100660 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800661 depends on X86_EXTENDED_PLATFORM
662 select M486
663 select X86_REBOOTFIXUPS
664 ---help---
665 This option is needed for RDC R-321x system-on-chip, also known
666 as R-8610-(G).
667 If you don't have one of these chips, you should say N here.
668
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100669config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100670 bool "Support non-standard 32-bit SMP architectures"
671 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800672 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100673 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800674 This option compiles in the bigsmp and STA2X11 default
675 subarchitectures. It is intended for a generic binary
676 kernel. If you select them all, kernel will probe it one by
677 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700678
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800679# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700680
Linus Torvaldsd949f362009-09-26 09:35:07 -0700681config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100682 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700683 # MCE code calls memory_failure():
684 depends on X86_MCE
685 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700686 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
687 depends on X86_64 || !SPARSEMEM
688 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700689
Alessandro Rubini83125a32012-04-04 19:40:21 +0200690config STA2X11
691 bool "STA2X11 Companion Chip Support"
692 depends on X86_32_NON_STANDARD && PCI
693 select X86_DEV_DMA_OPS
694 select X86_DMA_REMAP
695 select SWIOTLB
696 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200697 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200698 default n
699 ---help---
700 This adds support for boards based on the STA2X11 IO-Hub,
701 a.k.a. "ConneXt". The chip is used in place of the standard
702 PC chipset, so all "standard" peripherals are missing. If this
703 option is selected the kernel will still be able to boot on
704 standard PC machines.
705
Shérab82148d12010-09-25 06:06:57 +0200706config X86_32_IRIS
707 tristate "Eurobraille/Iris poweroff module"
708 depends on X86_32
709 ---help---
710 The Iris machines from EuroBraille do not have APM or ACPI support
711 to shut themselves down properly. A special I/O sequence is
712 needed to do so, which is what this module does at
713 kernel shutdown.
714
715 This is only for Iris machines from EuroBraille.
716
717 If unused, say N.
718
Ingo Molnarae1e9132008-11-11 09:05:16 +0100719config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100720 def_bool y
721 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800722 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100723 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100724 Calculate simpler /proc/<PID>/wchan values. If this option
725 is disabled then wchan values will recurse back to the
726 caller function. This provides more accurate wchan values,
727 at the expense of slightly more scheduling overhead.
728
729 If in doubt, say "Y".
730
Borislav Petkov6276a072013-03-04 21:20:21 +0100731menuconfig HYPERVISOR_GUEST
732 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100733 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100734 Say Y here to enable options for running Linux under various hyper-
735 visors. This option enables basic hypervisor detection and platform
736 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100737
Borislav Petkov6276a072013-03-04 21:20:21 +0100738 If you say N, all options in this submenu will be skipped and
739 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100740
Borislav Petkov6276a072013-03-04 21:20:21 +0100741if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100742
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100743config PARAVIRT
744 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100745 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100746 This changes the kernel so it can modify itself when it is run
747 under a hypervisor, potentially improving performance significantly
748 over full virtualization. However, when run without a hypervisor
749 the kernel is theoretically slower and slightly larger.
750
Borislav Petkov6276a072013-03-04 21:20:21 +0100751config PARAVIRT_DEBUG
752 bool "paravirt-ops debugging"
753 depends on PARAVIRT && DEBUG_KERNEL
754 ---help---
755 Enable to debug paravirt_ops internals. Specifically, BUG if
756 a paravirt_op is missing when it is called.
757
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700758config PARAVIRT_SPINLOCKS
759 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700760 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700761 ---help---
762 Paravirtualized spinlocks allow a pvops backend to replace the
763 spinlock implementation with something virtualization-friendly
764 (for example, block the virtual CPU rather than spinning).
765
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530766 It has a minimal impact on native kernels and gives a nice performance
767 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700768
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530769 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700770
Waiman Long45e898b2015-11-09 19:09:25 -0500771config QUEUED_LOCK_STAT
772 bool "Paravirt queued spinlock statistics"
Peter Zijlstracfd89832016-05-18 20:43:02 +0200773 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
Waiman Long45e898b2015-11-09 19:09:25 -0500774 ---help---
775 Enable the collection of statistical data on the slowpath
776 behavior of paravirtualized queued spinlocks and report
777 them on debugfs.
778
Borislav Petkov6276a072013-03-04 21:20:21 +0100779source "arch/x86/xen/Kconfig"
780
781config KVM_GUEST
782 bool "KVM Guest support (including kvmclock)"
783 depends on PARAVIRT
784 select PARAVIRT_CLOCK
785 default y
786 ---help---
787 This option enables various optimizations for running under the KVM
788 hypervisor. It includes a paravirtualized clock, so that instead
789 of relying on a PIT (or probably other) emulation by the
790 underlying device model, the host provides the guest with
791 timing infrastructure such as time of day, and system time
792
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530793config KVM_DEBUG_FS
794 bool "Enable debug information for KVM Guests in debugfs"
795 depends on KVM_GUEST && DEBUG_FS
796 default n
797 ---help---
798 This option enables collection of various statistics for KVM guest.
799 Statistics are displayed in debugfs filesystem. Enabling this option
800 may incur significant overhead.
801
Borislav Petkov6276a072013-03-04 21:20:21 +0100802config PARAVIRT_TIME_ACCOUNTING
803 bool "Paravirtual steal time accounting"
804 depends on PARAVIRT
805 default n
806 ---help---
807 Select this option to enable fine granularity task steal time
808 accounting. Time spent executing other tasks in parallel with
809 the current vCPU is discounted from the vCPU power. To account for
810 that, there can be a small performance impact.
811
812 If in doubt, say N here.
813
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200814config PARAVIRT_CLOCK
815 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200816
Jan Kiszka4a362602017-11-27 09:11:46 +0100817config JAILHOUSE_GUEST
818 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100819 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100820 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100821 ---help---
822 This option allows to run Linux as guest in a Jailhouse non-root
823 cell. You can leave this option disabled if you only want to start
824 Jailhouse and run Linux afterwards in the root cell.
825
Borislav Petkov6276a072013-03-04 21:20:21 +0100826endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400827
Yinghai Lu08677212010-02-10 01:20:20 -0800828config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700829 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800830
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100831source "arch/x86/Kconfig.cpu"
832
833config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100834 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100835 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100836 ---help---
837 Use the IA-PC HPET (High Precision Event Timer) to manage
838 time in preference to the PIT and RTC, if a HPET is
839 present.
840 HPET is the next generation timer replacing legacy 8254s.
841 The HPET provides a stable time base on SMP
842 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200843 as it is off-chip. The interface used is documented
844 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100845
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100846 You can safely choose Y here. However, HPET will only be
847 activated if the platform and the BIOS support this feature.
848 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100849
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100850 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100851
852config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100853 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800854 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100855
Jacob Panbb24c472009-09-02 07:37:17 -0700856config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000857 def_bool y if X86_INTEL_MID
858 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100859 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000860 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700861 help
862 APB timer is the replacement for 8254, HPET on X86 MID platforms.
863 The APBT provides a stable time base on SMP
864 systems, unlike the TSC, but it is more expensive to access,
865 as it is off-chip. APB timers are always running regardless of CPU
866 C states, they are used as per CPU clockevent device when possible.
867
David Rientjes6a108a12011-01-20 14:44:16 -0800868# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100869# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700870config DMI
871 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800872 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800873 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100874 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700875 Enabled scanning of DMI to identify machine quirks. Say Y
876 here unless you have verified that your setup is not
877 affected by entries in the DMI blacklist. Required by PNP
878 BIOS code.
879
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100880config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700881 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100882 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200883 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100884 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200885 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
886 GART based hardware IOMMUs.
887
888 The GART supports full DMA access for devices with 32-bit access
889 limitations, on systems with more than 3 GB. This is usually needed
890 for USB, sound, many IDE/SATA chipsets and some other devices.
891
892 Newer systems typically have a modern AMD IOMMU, supported via
893 the CONFIG_AMD_IOMMU=y config option.
894
895 In normal configurations this driver is only active when needed:
896 there's more than 3 GB of memory and the system contains a
897 32-bit limited device.
898
899 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100900
901config CALGARY_IOMMU
902 bool "IBM Calgary IOMMU support"
903 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700904 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100905 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100906 Support for hardware IOMMUs in IBM's xSeries x366 and x460
907 systems. Needed to run systems with more than 3GB of memory
908 properly with 32-bit PCI devices that do not support DAC
909 (Double Address Cycle). Calgary also supports bus level
910 isolation, where all DMAs pass through the IOMMU. This
911 prevents them from going anywhere except their intended
912 destination. This catches hard-to-find kernel bugs and
913 mis-behaving drivers and devices that do not use the DMA-API
914 properly to set up their DMA buffers. The IOMMU can be
915 turned off at boot time with the iommu=off parameter.
916 Normally the kernel will make the right choice by itself.
917 If unsure, say Y.
918
919config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100920 def_bool y
921 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100922 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100923 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100924 Should Calgary be enabled by default? if you choose 'y', Calgary
925 will be used (if it exists). If you choose 'n', Calgary will not be
926 used even if it exists. If you choose 'n' and would like to use
927 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
928 If unsure, say Y.
929
930# need this always selected by IOMMU for the VIA workaround
931config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100932 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100933 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100934 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700935 which don't have a hardware IOMMU. Using this PCI devices
936 which can only access 32-bits of memory can be used on systems
937 with more than 3 GB of memory.
938 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100939
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700940config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100941 def_bool y
942 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700943
Mike Travis1184dc22008-05-12 21:21:12 +0200944config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200945 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700946 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800947 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100948 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200949 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200950 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100951
Ingo Molnaraec64872018-02-10 12:36:29 +0100952#
953# The maximum number of CPUs supported:
954#
955# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
956# and which can be configured interactively in the
957# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
958#
959# The ranges are different on 32-bit and 64-bit kernels, depending on
960# hardware capabilities and scalability features of the kernel.
961#
962# ( If MAXSMP is enabled we just use the highest possible value and disable
963# interactive configuration. )
964#
965
966config NR_CPUS_RANGE_BEGIN
967 int
968 default NR_CPUS_RANGE_END if MAXSMP
969 default 1 if !SMP
970 default 2
971
972config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800973 int
974 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100975 default 64 if SMP && X86_BIGSMP
976 default 8 if SMP && !X86_BIGSMP
977 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800978
Ingo Molnaraec64872018-02-10 12:36:29 +0100979config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800980 int
981 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100982 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
983 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
984 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800985
Ingo Molnaraec64872018-02-10 12:36:29 +0100986config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800987 int
988 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100989 default 32 if X86_BIGSMP
990 default 8 if SMP
991 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800992
Ingo Molnaraec64872018-02-10 12:36:29 +0100993config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800994 int
995 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100996 default 8192 if MAXSMP
997 default 64 if SMP
998 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800999
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001000config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -08001001 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +01001002 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1003 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001004 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001005 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001006 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001007 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001008 minimum value which makes sense is 2.
1009
Ingo Molnaraec64872018-02-10 12:36:29 +01001010 This is purely to save memory: each supported CPU adds about 8KB
1011 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001012
1013config SCHED_SMT
1014 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001015 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001016 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001017 SMT scheduler support improves the CPU scheduler's decision making
1018 when dealing with Intel Pentium 4 chips with HyperThreading at a
1019 cost of slightly increased overhead in some places. If unsure say
1020 N here.
1021
1022config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001023 def_bool y
1024 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001025 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001026 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001027 Multi-core scheduler support improves the CPU scheduler's decision
1028 making when dealing with multi-core CPU chips at a cost of slightly
1029 increased overhead in some places. If unsure say N here.
1030
Tim Chende966cf2016-11-29 10:43:27 -08001031config SCHED_MC_PRIO
1032 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001033 depends on SCHED_MC && CPU_SUP_INTEL
1034 select X86_INTEL_PSTATE
1035 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001036 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001037 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001038 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1039 core ordering determined at manufacturing time, which allows
1040 certain cores to reach higher turbo frequencies (when running
1041 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001042
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001043 Enabling this kernel feature teaches the scheduler about
1044 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1045 scheduler's CPU selection logic accordingly, so that higher
1046 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001047
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001048 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001049
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001050 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001051
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001052source "kernel/Kconfig.preempt"
1053
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001054config UP_LATE_INIT
1055 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +01001056 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001057
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001058config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001059 bool "Local APIC support on uniprocessors" if !PCI_MSI
1060 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001061 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001062 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001063 A local APIC (Advanced Programmable Interrupt Controller) is an
1064 integrated interrupt controller in the CPU. If you have a single-CPU
1065 system which has a processor with a local APIC, you can say Y here to
1066 enable and use it. If you say Y here even though your machine doesn't
1067 have a local APIC, then the kernel will still run with no slowdown at
1068 all. The local APIC supports CPU-generated self-interrupts (timer,
1069 performance counters), and the NMI watchdog which detects hard
1070 lockups.
1071
1072config X86_UP_IOAPIC
1073 bool "IO-APIC support on uniprocessors"
1074 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001075 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001076 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1077 SMP-capable replacement for PC-style interrupt controllers. Most
1078 SMP systems and many recent uniprocessor systems have one.
1079
1080 If you have a single-CPU system with an IO-APIC, you can say Y here
1081 to use it. If you say Y here even though your machine doesn't have
1082 an IO-APIC, then the kernel will still run with no slowdown at all.
1083
1084config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001085 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001086 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001087 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001088 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001089
1090config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001091 def_bool y
1092 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001093
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001094config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1095 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001096 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001097 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001098 This option enables a workaround that fixes a source of
1099 spurious interrupts. This is recommended when threaded
1100 interrupt handling is used on systems where the generation of
1101 superfluous "boot interrupts" cannot be disabled.
1102
1103 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1104 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1105 kernel does during interrupt handling). On chipsets where this
1106 boot IRQ generation cannot be disabled, this workaround keeps
1107 the original IRQ line masked so that only the equivalent "boot
1108 IRQ" is delivered to the CPUs. The workaround also tells the
1109 kernel to set up the IRQ handler on the boot IRQ line. In this
1110 way only one interrupt is delivered to the kernel. Otherwise
1111 the spurious second interrupt may cause the kernel to bring
1112 down (vital) interrupt lines.
1113
1114 Only affects "broken" chipsets. Interrupt sharing may be
1115 increased on these systems.
1116
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001117config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001118 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001119 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001120 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001121 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001122 Machine Check support allows the processor to notify the
1123 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001124 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001125 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001126
Tony Luck5de97c92017-03-27 11:33:03 +02001127config X86_MCELOG_LEGACY
1128 bool "Support for deprecated /dev/mcelog character device"
1129 depends on X86_MCE
1130 ---help---
1131 Enable support for /dev/mcelog which is needed by the old mcelog
1132 userspace logging daemon. Consider switching to the new generation
1133 rasdaemon solution.
1134
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001135config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001136 def_bool y
1137 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001138 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001139 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001140 Additional support for intel specific MCE features such as
1141 the thermal monitor.
1142
1143config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001144 def_bool y
1145 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001146 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001147 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001148 Additional support for AMD specific MCE features such as
1149 the DRAM Error Threshold.
1150
Andi Kleen4efc0672009-04-28 19:07:31 +02001151config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001152 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001153 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001154 ---help---
1155 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001156 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001157 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001158
Andi Kleenb2762682009-02-12 13:49:31 +01001159config X86_MCE_THRESHOLD
1160 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001161 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001162
Andi Kleenea149b32009-04-29 19:31:00 +02001163config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001164 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001165 tristate "Machine check injector support"
1166 ---help---
1167 Provide support for injecting machine checks for testing purposes.
1168 If you don't know what a machine check is and you don't do kernel
1169 QA it is safe to say n.
1170
Andi Kleen4efc0672009-04-28 19:07:31 +02001171config X86_THERMAL_VECTOR
1172 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001173 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001174
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001175source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001176
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001177config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001178 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001179 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001180 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001181 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001182 This option allows user programs to put the CPU into V8086
1183 mode, which is an 80286-era approximation of 16-bit real mode.
1184
1185 Some very old versions of X and/or vbetool require this option
1186 for user mode setting. Similarly, DOSEMU will use it if
1187 available to accelerate real mode DOS programs. However, any
1188 recent version of DOSEMU, X, or vbetool should be fully
1189 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001190 fall back to software emulation. Nevertheless, if you are using
1191 a 16-bit DOS program where 16-bit performance matters, vm86
1192 mode might be faster than emulation and you might want to
1193 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001194
Ingo Molnar1e642812015-09-05 08:58:10 +02001195 Note that any app that works on a 64-bit kernel is unlikely to
1196 need this option, as 64-bit kernels don't, and can't, support
1197 V8086 mode. This option is also unrelated to 16-bit protected
1198 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001199
Ingo Molnar1e642812015-09-05 08:58:10 +02001200 Enabling this option increases the complexity of the kernel
1201 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001202
Ingo Molnar1e642812015-09-05 08:58:10 +02001203 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001204
1205config VM86
1206 bool
1207 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001208
1209config X86_16BIT
1210 bool "Enable support for 16-bit segments" if EXPERT
1211 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001212 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001213 ---help---
1214 This option is required by programs like Wine to run 16-bit
1215 protected mode legacy code on x86 processors. Disabling
1216 this option saves about 300 bytes on i386, or around 6K text
1217 plus 16K runtime memory on x86-64,
1218
1219config X86_ESPFIX32
1220 def_bool y
1221 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001222
H. Peter Anvin197725d2014-05-04 10:00:49 -07001223config X86_ESPFIX64
1224 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001225 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001226
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001227config X86_VSYSCALL_EMULATION
1228 bool "Enable vsyscall emulation" if EXPERT
1229 default y
1230 depends on X86_64
1231 ---help---
1232 This enables emulation of the legacy vsyscall page. Disabling
1233 it is roughly equivalent to booting with vsyscall=none, except
1234 that it will also disable the helpful warning if a program
1235 tries to use a vsyscall. With this option set to N, offending
1236 programs will just segfault, citing addresses of the form
1237 0xffffffffff600?00.
1238
1239 This option is required by many programs built before 2013, and
1240 care should be used even with newer programs if set to N.
1241
1242 Disabling this option saves about 7K of kernel size and
1243 possibly 4K of additional runtime pagetable memory.
1244
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001245config TOSHIBA
1246 tristate "Toshiba Laptop support"
1247 depends on X86_32
1248 ---help---
1249 This adds a driver to safely access the System Management Mode of
1250 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1251 not work on models with a Phoenix BIOS. The System Management Mode
1252 is used to set the BIOS and power saving options on Toshiba portables.
1253
1254 For information on utilities to make use of this driver see the
1255 Toshiba Linux utilities web site at:
1256 <http://www.buzzard.org.uk/toshiba/>.
1257
1258 Say Y if you intend to run this kernel on a Toshiba portable.
1259 Say N otherwise.
1260
1261config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001262 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001263 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001264 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001265 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001266 This option enables legacy /proc/i8k userspace interface in hwmon
1267 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1268 temperature and allows controlling fan speeds of Dell laptops via
1269 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1270 it reports also power and hotkey status. For fan speed control is
1271 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001272
Pali Rohár039ae582015-05-14 13:16:37 +02001273 Say Y if you intend to run this kernel on old Dell laptops or want to
1274 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001275 Say N otherwise.
1276
1277config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001278 bool "Enable X86 board specific fixups for reboot"
1279 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001280 ---help---
1281 This enables chipset and/or board specific fixups to be done
1282 in order to get reboot to work correctly. This is only needed on
1283 some combinations of hardware and BIOS. The symptom, for which
1284 this config is intended, is when reboot ends with a stalled/hung
1285 system.
1286
1287 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001288 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001289
1290 Say Y if you want to enable the fixup. Currently, it's safe to
1291 enable this option even if you don't need it.
1292 Say N otherwise.
1293
1294config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001295 bool "CPU microcode loading support"
1296 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001297 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001298 select FW_LOADER
1299 ---help---
1300 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001301 Intel and AMD processors. The Intel support is for the IA32 family,
1302 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1303 AMD support is for families 0x10 and later. You will obviously need
1304 the actual microcode binary data itself which is not shipped with
1305 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001306
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001307 The preferred method to load microcode from a detached initrd is described
1308 in Documentation/x86/early-microcode.txt. For that you need to enable
1309 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1310 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001312 In addition, you can build the microcode into the kernel. For that you
1313 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1314 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001315
Peter Oruba8d86f392008-07-28 18:44:21 +02001316config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001317 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001318 depends on MICROCODE
1319 default MICROCODE
1320 select FW_LOADER
1321 ---help---
1322 This options enables microcode patch loading support for Intel
1323 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001324
Alanb8989db2014-01-20 18:01:56 +00001325 For the current Intel microcode data package go to
1326 <https://downloadcenter.intel.com> and search for
1327 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001328
Peter Oruba80cc9f12008-07-28 18:44:22 +02001329config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001330 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001331 depends on MICROCODE
1332 select FW_LOADER
1333 ---help---
1334 If you select this option, microcode patch loading support for AMD
1335 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001336
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001337config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001338 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001339 depends on MICROCODE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001340
1341config X86_MSR
1342 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001343 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001344 This device gives privileged processes access to the x86
1345 Model-Specific Registers (MSRs). It is a character device with
1346 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1347 MSR accesses are directed to a specific CPU on multi-processor
1348 systems.
1349
1350config X86_CPUID
1351 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001352 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001353 This device gives processes access to the x86 CPUID instruction to
1354 be executed on a specific processor. It is a character device
1355 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1356 /dev/cpu/31/cpuid.
1357
1358choice
1359 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001360 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001361 depends on X86_32
1362
1363config NOHIGHMEM
1364 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001365 ---help---
1366 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1367 However, the address space of 32-bit x86 processors is only 4
1368 Gigabytes large. That means that, if you have a large amount of
1369 physical memory, not all of it can be "permanently mapped" by the
1370 kernel. The physical memory that's not permanently mapped is called
1371 "high memory".
1372
1373 If you are compiling a kernel which will never run on a machine with
1374 more than 1 Gigabyte total physical RAM, answer "off" here (default
1375 choice and suitable for most users). This will result in a "3GB/1GB"
1376 split: 3GB are mapped so that each process sees a 3GB virtual memory
1377 space and the remaining part of the 4GB virtual memory space is used
1378 by the kernel to permanently map as much physical memory as
1379 possible.
1380
1381 If the machine has between 1 and 4 Gigabytes physical RAM, then
1382 answer "4GB" here.
1383
1384 If more than 4 Gigabytes is used then answer "64GB" here. This
1385 selection turns Intel PAE (Physical Address Extension) mode on.
1386 PAE implements 3-level paging on IA32 processors. PAE is fully
1387 supported by Linux, PAE mode is implemented on all recent Intel
1388 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1389 then the kernel will not boot on CPUs that don't support PAE!
1390
1391 The actual amount of total physical memory will either be
1392 auto detected or can be forced by using a kernel command line option
1393 such as "mem=256M". (Try "man bootparam" or see the documentation of
1394 your boot loader (lilo or loadlin) about how to pass options to the
1395 kernel at boot time.)
1396
1397 If unsure, say "off".
1398
1399config HIGHMEM4G
1400 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001401 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001402 Select this if you have a 32-bit processor and between 1 and 4
1403 gigabytes of physical RAM.
1404
1405config HIGHMEM64G
1406 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001407 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001408 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001409 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001410 Select this if you have a 32-bit processor and more than 4
1411 gigabytes of physical RAM.
1412
1413endchoice
1414
1415choice
David Rientjes6a108a12011-01-20 14:44:16 -08001416 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001417 default VMSPLIT_3G
1418 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001419 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001420 Select the desired split between kernel and user memory.
1421
1422 If the address range available to the kernel is less than the
1423 physical memory installed, the remaining memory will be available
1424 as "high memory". Accessing high memory is a little more costly
1425 than low memory, as it needs to be mapped into the kernel first.
1426 Note that increasing the kernel address space limits the range
1427 available to user programs, making the address space there
1428 tighter. Selecting anything other than the default 3G/1G split
1429 will also likely make your kernel incompatible with binary-only
1430 kernel modules.
1431
1432 If you are not absolutely sure what you are doing, leave this
1433 option alone!
1434
1435 config VMSPLIT_3G
1436 bool "3G/1G user/kernel split"
1437 config VMSPLIT_3G_OPT
1438 depends on !X86_PAE
1439 bool "3G/1G user/kernel split (for full 1G low memory)"
1440 config VMSPLIT_2G
1441 bool "2G/2G user/kernel split"
1442 config VMSPLIT_2G_OPT
1443 depends on !X86_PAE
1444 bool "2G/2G user/kernel split (for full 2G low memory)"
1445 config VMSPLIT_1G
1446 bool "1G/3G user/kernel split"
1447endchoice
1448
1449config PAGE_OFFSET
1450 hex
1451 default 0xB0000000 if VMSPLIT_3G_OPT
1452 default 0x80000000 if VMSPLIT_2G
1453 default 0x78000000 if VMSPLIT_2G_OPT
1454 default 0x40000000 if VMSPLIT_1G
1455 default 0xC0000000
1456 depends on X86_32
1457
1458config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001459 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001460 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001461
1462config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001463 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001464 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001465 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001466 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001467 PAE is required for NX support, and furthermore enables
1468 larger swapspace support for non-overcommit purposes. It
1469 has the cost of more pagetable lookup overhead, and also
1470 consumes more pagetable space per process.
1471
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001472config X86_5LEVEL
1473 bool "Enable 5-level page tables support"
1474 depends on X86_64
1475 ---help---
1476 5-level paging enables access to larger address space:
1477 upto 128 PiB of virtual address space and 4 PiB of
1478 physical address space.
1479
1480 It will be supported by future Intel CPUs.
1481
1482 Note: a kernel with this option enabled can only be booted
1483 on machines that support the feature.
1484
1485 See Documentation/x86/x86_64/5level-paging.txt for more
1486 information.
1487
1488 Say N if unsure.
1489
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001490config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001491 def_bool y
1492 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001493
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001494config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001495 def_bool y
1496 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001497
Ingo Molnar10971ab2015-03-05 08:18:23 +01001498config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001499 def_bool y
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -08001500 depends on X86_64 && !DEBUG_PAGEALLOC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001501 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001502 Certain kernel features effectively disable kernel
1503 linear 1 GB mappings (even if the CPU otherwise
1504 supports them), so don't confuse the user by printing
1505 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001506
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001507config ARCH_HAS_MEM_ENCRYPT
1508 def_bool y
1509
1510config AMD_MEM_ENCRYPT
1511 bool "AMD Secure Memory Encryption (SME) support"
1512 depends on X86_64 && CPU_SUP_AMD
1513 ---help---
1514 Say yes to enable support for the encryption of system memory.
1515 This requires an AMD processor that supports Secure Memory
1516 Encryption (SME).
1517
1518config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1519 bool "Activate AMD Secure Memory Encryption (SME) by default"
1520 default y
1521 depends on AMD_MEM_ENCRYPT
1522 ---help---
1523 Say yes to have system memory encrypted by default if running on
1524 an AMD processor that supports Secure Memory Encryption (SME).
1525
1526 If set to Y, then the encryption of system memory can be
1527 deactivated with the mem_encrypt=off command line option.
1528
1529 If set to N, then the encryption of system memory can be
1530 activated with the mem_encrypt=on command line option.
1531
Tom Lendackyf88a68f2017-07-17 16:10:09 -05001532config ARCH_USE_MEMREMAP_PROT
1533 def_bool y
1534 depends on AMD_MEM_ENCRYPT
1535
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001536# Common NUMA Features
1537config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001538 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001539 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001540 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1541 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001542 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001543 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001544
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001545 The kernel will try to allocate memory used by a CPU on the
1546 local memory controller of the CPU and add some more
1547 NUMA awareness to the kernel.
1548
Ingo Molnarc280ea52008-11-08 13:29:45 +01001549 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001550 (or later), AMD Opteron, or EM64T NUMA.
1551
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001552 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001553 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001554
1555 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001556
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001557config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001558 def_bool y
1559 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001560 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001561 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001562 Enable AMD NUMA node topology detection. You should say Y here if
1563 you have a multi processor AMD system. This uses an old method to
1564 read the NUMA configuration directly from the builtin Northbridge
1565 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1566 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001567
1568config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001569 def_bool y
1570 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001571 depends on X86_64 && NUMA && ACPI && PCI
1572 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001573 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001574 Enable ACPI SRAT based node topology detection.
1575
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001576# Some NUMA nodes have memory ranges that span
1577# other nodes. Even though a pfn is valid and
1578# between a node's start and end pfns, it may not
1579# reside on that node. See memmap_init_zone()
1580# for details.
1581config NODES_SPAN_OTHER_NODES
1582 def_bool y
1583 depends on X86_64_ACPI_NUMA
1584
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001585config NUMA_EMU
1586 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001587 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001588 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001589 Enable NUMA emulation. A flat machine will be split
1590 into virtual nodes when booted with "numa=fake=N", where N is the
1591 number of nodes. This is only useful for debugging.
1592
1593config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001594 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001595 range 1 10
1596 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001597 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001598 default "3"
1599 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001600 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001601 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001602 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001603
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001604config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001605 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001606 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001607
1608config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001609 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001610 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001611
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001612config ARCH_FLATMEM_ENABLE
1613 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001614 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615
1616config ARCH_DISCONTIGMEM_ENABLE
1617 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001618 depends on NUMA && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001619
1620config ARCH_DISCONTIGMEM_DEFAULT
1621 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001622 depends on NUMA && X86_32
1623
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001624config ARCH_SPARSEMEM_ENABLE
1625 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001626 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001627 select SPARSEMEM_STATIC if X86_32
1628 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1629
Tejun Heo3b166512011-04-01 11:15:12 +02001630config ARCH_SPARSEMEM_DEFAULT
1631 def_bool y
1632 depends on X86_64
1633
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001634config ARCH_SELECT_MEMORY_MODEL
1635 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001636 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001637
1638config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001639 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001640 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001641 help
1642 This option enables a sysfs memory/probe interface for testing.
1643 See Documentation/memory-hotplug.txt for more information.
1644 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001645
Tejun Heo3b166512011-04-01 11:15:12 +02001646config ARCH_PROC_KCORE_TEXT
1647 def_bool y
1648 depends on X86_64 && PROC_KCORE
1649
Avi Kivitya29815a2010-01-10 16:28:09 +02001650config ILLEGAL_POINTER_VALUE
1651 hex
1652 default 0 if X86_32
1653 default 0xdead000000000000 if X86_64
1654
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001655source "mm/Kconfig"
1656
Dan Williams7a678322015-08-19 00:34:34 -04001657config X86_PMEM_LEGACY_DEVICE
1658 bool
1659
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001660config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001661 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001662 depends on PHYS_ADDR_T_64BIT
1663 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001664 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001665 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001666 help
1667 Treat memory marked using the non-standard e820 type of 12 as used
1668 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1669 The kernel will offer these regions to the 'pmem' driver so
1670 they can be used for persistent storage.
1671
1672 Say Y if unsure.
1673
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001674config HIGHPTE
1675 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001676 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001677 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001678 The VM uses one page table entry for each page of physical memory.
1679 For systems with a lot of RAM, this can be wasteful of precious
1680 low memory. Setting this option will put user-space page table
1681 entries in high memory.
1682
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001683config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001684 bool "Check for low memory corruption"
1685 ---help---
1686 Periodically check for memory corruption in low memory, which
1687 is suspected to be caused by BIOS. Even when enabled in the
1688 configuration, it is disabled at runtime. Enable it by
1689 setting "memory_corruption_check=1" on the kernel command
1690 line. By default it scans the low 64k of memory every 60
1691 seconds; see the memory_corruption_check_size and
1692 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001693 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001694
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001695 When enabled with the default parameters, this option has
1696 almost no overhead, as it reserves a relatively small amount
1697 of memory and scans it infrequently. It both detects corruption
1698 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001699
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001700 It is, however, intended as a diagnostic tool; if repeatable
1701 BIOS-originated corruption always affects the same memory,
1702 you can use memmap= to prevent the kernel from using that
1703 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001704
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001705config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001706 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001707 depends on X86_CHECK_BIOS_CORRUPTION
1708 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001709 ---help---
1710 Set whether the default state of memory_corruption_check is
1711 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001712
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001713config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001714 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1715 default 64
1716 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001717 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001718 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001719
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001720 The first page contains BIOS data structures that the kernel
1721 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001722
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001723 By default we reserve the first 64K of physical RAM, as a
1724 number of BIOSes are known to corrupt that memory range
1725 during events such as suspend/resume or monitor cable
1726 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001727
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001728 You can set this to 4 if you are absolutely sure that you
1729 trust the BIOS to get all its memory reservations and usages
1730 right. If you know your BIOS have problems beyond the
1731 default 64K area, you can set this to 640 to avoid using the
1732 entire low memory range.
1733
1734 If you have doubts about the BIOS (e.g. suspend/resume does
1735 not work or there's kernel crashes after certain hardware
1736 hotplug events) then you might want to enable
1737 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1738 typical corruption patterns.
1739
1740 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001741
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001742config MATH_EMULATION
1743 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001744 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001745 prompt "Math emulation" if X86_32
1746 ---help---
1747 Linux can emulate a math coprocessor (used for floating point
1748 operations) if you don't have one. 486DX and Pentium processors have
1749 a math coprocessor built in, 486SX and 386 do not, unless you added
1750 a 487DX or 387, respectively. (The messages during boot time can
1751 give you some hints here ["man dmesg"].) Everyone needs either a
1752 coprocessor or this emulation.
1753
1754 If you don't have a math coprocessor, you need to say Y here; if you
1755 say Y here even though you have a coprocessor, the coprocessor will
1756 be used nevertheless. (This behavior can be changed with the kernel
1757 command line option "no387", which comes handy if your coprocessor
1758 is broken. Try "man bootparam" or see the documentation of your boot
1759 loader (lilo or loadlin) about how to pass options to the kernel at
1760 boot time.) This means that it is a good idea to say Y here if you
1761 intend to use this kernel on different machines.
1762
1763 More information about the internals of the Linux math coprocessor
1764 emulation can be found in <file:arch/x86/math-emu/README>.
1765
1766 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1767 kernel, it won't hurt.
1768
1769config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001770 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001771 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001772 ---help---
1773 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1774 the Memory Type Range Registers (MTRRs) may be used to control
1775 processor access to memory ranges. This is most useful if you have
1776 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1777 allows bus write transfers to be combined into a larger transfer
1778 before bursting over the PCI/AGP bus. This can increase performance
1779 of image write operations 2.5 times or more. Saying Y here creates a
1780 /proc/mtrr file which may be used to manipulate your processor's
1781 MTRRs. Typically the X server should use this.
1782
1783 This code has a reasonably generic interface so that similar
1784 control registers on other processors can be easily supported
1785 as well:
1786
1787 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1788 Registers (ARRs) which provide a similar functionality to MTRRs. For
1789 these, the ARRs are used to emulate the MTRRs.
1790 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1791 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1792 write-combining. All of these processors are supported by this code
1793 and it makes sense to say Y here if you have one of them.
1794
1795 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1796 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1797 can lead to all sorts of problems, so it's good to say Y here.
1798
1799 You can safely say Y even if your machine doesn't have MTRRs, you'll
1800 just add about 9 KB to your kernel.
1801
Randy Dunlap7225e752008-07-26 17:54:22 -07001802 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001803
Yinghai Lu95ffa242008-04-29 03:52:33 -07001804config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001805 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001806 prompt "MTRR cleanup support"
1807 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001808 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001809 Convert MTRR layout from continuous to discrete, so X drivers can
1810 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001811
Thomas Gleixneraba37282008-07-15 14:48:48 +02001812 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001813 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001814 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001815
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001816 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001817
1818config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001819 int "MTRR cleanup enable value (0-1)"
1820 range 0 1
1821 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001822 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001823 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001824 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001825
Yinghai Lu12031a62008-05-02 02:40:22 -07001826config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1827 int "MTRR cleanup spare reg num (0-7)"
1828 range 0 7
1829 default "1"
1830 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001831 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001832 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001833 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001834
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001835config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001836 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001837 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001838 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001839 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001840 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001841
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001842 PATs are the modern equivalents of MTRRs and are much more
1843 flexible than MTRRs.
1844
1845 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001846 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001847
1848 If unsure, say Y.
1849
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001850config ARCH_USES_PG_UNCACHED
1851 def_bool y
1852 depends on X86_PAT
1853
H. Peter Anvin628c6242011-07-31 13:59:29 -07001854config ARCH_RANDOM
1855 def_bool y
1856 prompt "x86 architectural random number generator" if EXPERT
1857 ---help---
1858 Enable the x86 architectural RDRAND instruction
1859 (Intel Bull Mountain technology) to generate random numbers.
1860 If supported, this is a high bandwidth, cryptographically
1861 secure hardware random number generator.
1862
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001863config X86_SMAP
1864 def_bool y
1865 prompt "Supervisor Mode Access Prevention" if EXPERT
1866 ---help---
1867 Supervisor Mode Access Prevention (SMAP) is a security
1868 feature in newer Intel processors. There is a small
1869 performance cost if this enabled and turned on; there is
1870 also a small increase in the kernel size if this is enabled.
1871
1872 If unsure, say Y.
1873
Ricardo Neriaa35f892017-11-05 18:27:54 -08001874config X86_INTEL_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001875 def_bool y
Ricardo Neriaa35f892017-11-05 18:27:54 -08001876 depends on CPU_SUP_INTEL
1877 prompt "Intel User Mode Instruction Prevention" if EXPERT
1878 ---help---
1879 The User Mode Instruction Prevention (UMIP) is a security
1880 feature in newer Intel processors. If enabled, a general
Ricardo Neri796ebc82017-11-13 22:29:42 -08001881 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1882 or STR instructions are executed in user mode. These instructions
1883 unnecessarily expose information about the hardware state.
1884
1885 The vast majority of applications do not use these instructions.
1886 For the very few that do, software emulation is provided in
1887 specific cases in protected and virtual-8086 modes. Emulated
1888 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001889
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001890config X86_INTEL_MPX
1891 prompt "Intel MPX (Memory Protection Extensions)"
1892 def_bool n
Rik van Rieldf3735c2017-09-06 16:25:11 -07001893 # Note: only available in 64-bit mode due to VMA flags shortage
1894 depends on CPU_SUP_INTEL && X86_64
1895 select ARCH_USES_HIGH_VMA_FLAGS
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001896 ---help---
1897 MPX provides hardware features that can be used in
1898 conjunction with compiler-instrumented code to check
1899 memory references. It is designed to detect buffer
1900 overflow or underflow bugs.
1901
1902 This option enables running applications which are
1903 instrumented or otherwise use MPX. It does not use MPX
1904 itself inside the kernel or to protect the kernel
1905 against bad memory references.
1906
1907 Enabling this option will make the kernel larger:
1908 ~8k of kernel text and 36 bytes of data on a 64-bit
1909 defconfig. It adds a long to the 'mm_struct' which
1910 will increase the kernel memory overhead of each
1911 process and adds some branches to paths used during
1912 exec() and munmap().
1913
1914 For details, see Documentation/x86/intel_mpx.txt
1915
1916 If unsure, say N.
1917
Dave Hansen35e97792016-02-12 13:02:00 -08001918config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001919 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001920 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001921 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001922 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001923 select ARCH_USES_HIGH_VMA_FLAGS
1924 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001925 ---help---
1926 Memory Protection Keys provides a mechanism for enforcing
1927 page-based protections, but without requiring modification of the
1928 page tables when an application changes protection domains.
1929
1930 For details, see Documentation/x86/protection-keys.txt
1931
1932 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001933
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001934config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001935 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001936 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001937 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001938 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001939 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001940 This enables the kernel to use EFI runtime services that are
1941 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001942
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001943 This option is only useful on systems that have EFI firmware.
1944 In addition, you should use the latest ELILO loader available
1945 at <http://elilo.sourceforge.net> in order to take advantage
1946 of EFI runtime services. However, even with this option, the
1947 resultant kernel should continue to boot on existing non-EFI
1948 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001949
Matt Fleming291f3632011-12-12 21:27:52 +00001950config EFI_STUB
1951 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001952 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001953 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001954 ---help---
1955 This kernel feature allows a bzImage to be loaded directly
1956 by EFI firmware without the use of a bootloader.
1957
Roy Franz4172fe22013-09-22 15:45:25 -07001958 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001959
Matt Fleming7d453ee2014-01-10 18:52:06 +00001960config EFI_MIXED
1961 bool "EFI mixed-mode support"
1962 depends on EFI_STUB && X86_64
1963 ---help---
1964 Enabling this feature allows a 64-bit kernel to be booted
1965 on a 32-bit firmware, provided that your CPU supports 64-bit
1966 mode.
1967
1968 Note that it is not possible to boot a mixed-mode enabled
1969 kernel via the EFI boot stub - a bootloader that supports
1970 the EFI handover protocol must be used.
1971
1972 If unsure, say N.
1973
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001974config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001975 def_bool y
1976 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001977 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001978 This kernel feature is useful for number crunching applications
1979 that may need to compute untrusted bytecode during their
1980 execution. By using pipes or other transports made available to
1981 the process as file descriptors supporting the read/write
1982 syscalls, it's possible to isolate those applications in
1983 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001984 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001985 and the task is only allowed to execute a few safe syscalls
1986 defined by each seccomp mode.
1987
1988 If unsure, say Y. Only embedded should say N here.
1989
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001990source kernel/Kconfig.hz
1991
1992config KEXEC
1993 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001994 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001995 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001996 kexec is a system call that implements the ability to shutdown your
1997 current kernel, and to start another kernel. It is like a reboot
1998 but it is independent of the system firmware. And like a reboot
1999 you can start any kernel with it, not just Linux.
2000
2001 The name comes from the similarity to the exec system call.
2002
2003 It is an ongoing process to be certain the hardware in a machine
2004 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002005 initially work for you. As of this writing the exact hardware
2006 interface is strongly in flux, so no good recommendation can be
2007 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002008
Vivek Goyal74ca3172014-08-29 15:18:46 -07002009config KEXEC_FILE
2010 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002011 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002012 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002013 depends on X86_64
2014 depends on CRYPTO=y
2015 depends on CRYPTO_SHA256=y
2016 ---help---
2017 This is new version of kexec system call. This system call is
2018 file based and takes file descriptors as system call argument
2019 for kernel and initramfs as opposed to list of segments as
2020 accepted by previous system call.
2021
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002022config KEXEC_VERIFY_SIG
2023 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002024 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002025 ---help---
2026 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002027 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002028
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002029 In addition to that option, you need to enable signature
2030 verification for the corresponding kernel image type being
2031 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002032
2033config KEXEC_BZIMAGE_VERIFY_SIG
2034 bool "Enable bzImage signature verification support"
2035 depends on KEXEC_VERIFY_SIG
2036 depends on SIGNED_PE_FILE_VERIFICATION
2037 select SYSTEM_TRUSTED_KEYRING
2038 ---help---
2039 Enable bzImage signature verification support.
2040
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002041config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002042 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002043 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002044 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002045 Generate crash dump after being started by kexec.
2046 This should be normally only set in special crash dump kernels
2047 which are loaded in the main kernel with kexec-tools into
2048 a specially reserved region and then later executed after
2049 a crash by kdump/kexec. The crash dump kernel must be compiled
2050 to a memory address not used by the main kernel or BIOS using
2051 PHYSICAL_START, or it must be built as a relocatable image
2052 (CONFIG_RELOCATABLE=y).
2053 For more details see Documentation/kdump/kdump.txt
2054
Huang Ying3ab83522008-07-25 19:45:07 -07002055config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002056 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002057 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002058 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002059 Jump between original kernel and kexeced kernel and invoke
2060 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002061
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002062config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002063 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002064 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002065 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002066 This gives the physical address where the kernel is loaded.
2067
2068 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2069 bzImage will decompress itself to above physical address and
2070 run from there. Otherwise, bzImage will run from the address where
2071 it has been loaded by the boot loader and will ignore above physical
2072 address.
2073
2074 In normal kdump cases one does not have to set/change this option
2075 as now bzImage can be compiled as a completely relocatable image
2076 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2077 address. This option is mainly useful for the folks who don't want
2078 to use a bzImage for capturing the crash dump and want to use a
2079 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2080 to be specifically compiled to run from a specific memory area
2081 (normally a reserved region) and this option comes handy.
2082
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002083 So if you are using bzImage for capturing the crash dump,
2084 leave the value here unchanged to 0x1000000 and set
2085 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2086 for capturing the crash dump change this value to start of
2087 the reserved region. In other words, it can be set based on
2088 the "X" value as specified in the "crashkernel=YM@XM"
2089 command line boot parameter passed to the panic-ed
2090 kernel. Please take a look at Documentation/kdump/kdump.txt
2091 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002092
2093 Usage of bzImage for capturing the crash dump is recommended as
2094 one does not have to build two kernels. Same kernel can be used
2095 as production kernel and capture kernel. Above option should have
2096 gone away after relocatable bzImage support is introduced. But it
2097 is present because there are users out there who continue to use
2098 vmlinux for dump capture. This option should go away down the
2099 line.
2100
2101 Don't change this unless you know what you are doing.
2102
2103config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002104 bool "Build a relocatable kernel"
2105 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002106 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002107 This builds a kernel image that retains relocation information
2108 so it can be loaded someplace besides the default 1MB.
2109 The relocations tend to make the kernel binary about 10% larger,
2110 but are discarded at runtime.
2111
2112 One use is for the kexec on panic case where the recovery kernel
2113 must live at a different physical address than the primary
2114 kernel.
2115
2116 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2117 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002118 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002119
Kees Cook8ab38202013-10-10 17:18:14 -07002120config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002121 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002122 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002123 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002124 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002125 In support of Kernel Address Space Layout Randomization (KASLR),
2126 this randomizes the physical address at which the kernel image
2127 is decompressed and the virtual address where the kernel
2128 image is mapped, as a security feature that deters exploit
2129 attempts relying on knowledge of the location of kernel
2130 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002131
Kees Cooked9f0072016-05-25 15:45:33 -07002132 On 64-bit, the kernel physical and virtual addresses are
2133 randomized separately. The physical address will be anywhere
2134 between 16MB and the top of physical memory (up to 64TB). The
2135 virtual address will be randomized from 16MB up to 1GB (9 bits
2136 of entropy). Note that this also reduces the memory space
2137 available to kernel modules from 1.5GB to 1GB.
2138
2139 On 32-bit, the kernel physical and virtual addresses are
2140 randomized together. They will be randomized from 16MB up to
2141 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002142
Baoquan Hee8581e32016-04-20 13:55:43 -07002143 Entropy is generated using the RDRAND instruction if it is
2144 supported. If RDTSC is supported, its value is mixed into
2145 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002146 supported, then entropy is read from the i8254 timer. The
2147 usable entropy is limited by the kernel being built using
2148 2GB addressing, and that PHYSICAL_ALIGN must be at a
2149 minimum of 2MB. As a result, only 10 bits of entropy are
2150 theoretically possible, but the implementations are further
2151 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002152
Ingo Molnar6807c842017-04-18 11:08:12 +02002153 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002154
2155# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002156config X86_NEED_RELOCS
2157 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002158 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002159
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002160config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002161 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002162 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002163 range 0x2000 0x1000000 if X86_32
2164 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002165 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002166 This value puts the alignment restrictions on physical address
2167 where kernel is loaded and run from. Kernel is compiled for an
2168 address which meets above alignment restriction.
2169
2170 If bootloader loads the kernel at a non-aligned address and
2171 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2172 address aligned to above value and run from there.
2173
2174 If bootloader loads the kernel at a non-aligned address and
2175 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2176 load address and decompress itself to the address it has been
2177 compiled for and run from there. The address for which kernel is
2178 compiled already meets above alignment restrictions. Hence the
2179 end result is that kernel runs from a physical address meeting
2180 above alignment restrictions.
2181
Kees Cooka0215062013-07-08 09:15:17 -07002182 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2183 this value must be a multiple of 0x200000.
2184
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002185 Don't change this unless you know what you are doing.
2186
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002187config RANDOMIZE_MEMORY
2188 bool "Randomize the kernel memory sections"
2189 depends on X86_64
2190 depends on RANDOMIZE_BASE
2191 default RANDOMIZE_BASE
2192 ---help---
2193 Randomizes the base virtual address of kernel memory sections
2194 (physical memory mapping, vmalloc & vmemmap). This security feature
2195 makes exploits relying on predictable memory locations less reliable.
2196
2197 The order of allocations remains unchanged. Entropy is generated in
2198 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2199 configuration have in average 30,000 different possible virtual
2200 addresses for each memory section.
2201
Ingo Molnar6807c842017-04-18 11:08:12 +02002202 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002203
Thomas Garnier90397a42016-06-21 17:47:06 -07002204config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2205 hex "Physical memory mapping padding" if EXPERT
2206 depends on RANDOMIZE_MEMORY
2207 default "0xa" if MEMORY_HOTPLUG
2208 default "0x0"
2209 range 0x1 0x40 if MEMORY_HOTPLUG
2210 range 0x0 0x40
2211 ---help---
2212 Define the padding in terabytes added to the existing physical
2213 memory size during kernel memory randomization. It is useful
2214 for memory hotplug support but reduces the entropy available for
2215 address randomization.
2216
2217 If unsure, leave at the default value.
2218
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002219config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002220 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10002221 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002222 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002223 Say Y here to allow turning CPUs off and on. CPUs can be
2224 controlled through /sys/devices/system/cpu.
2225 ( Note: power management support will enable this option
2226 automatically on SMP systems. )
2227 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002228
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002229config BOOTPARAM_HOTPLUG_CPU0
2230 bool "Set default setting of cpu0_hotpluggable"
2231 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002232 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002233 ---help---
2234 Set whether default state of cpu0_hotpluggable is on or off.
2235
2236 Say Y here to enable CPU0 hotplug by default. If this switch
2237 is turned on, there is no need to give cpu0_hotplug kernel
2238 parameter and the CPU0 hotplug feature is enabled by default.
2239
2240 Please note: there are two known CPU0 dependencies if you want
2241 to enable the CPU0 hotplug feature either by this switch or by
2242 cpu0_hotplug kernel parameter.
2243
2244 First, resume from hibernate or suspend always starts from CPU0.
2245 So hibernate and suspend are prevented if CPU0 is offline.
2246
2247 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2248 offline if any interrupt can not migrate out of CPU0. There may
2249 be other CPU0 dependencies.
2250
2251 Please make sure the dependencies are under your control before
2252 you enable this feature.
2253
2254 Say N if you don't want to enable CPU0 hotplug feature by default.
2255 You still can enable the CPU0 hotplug feature at boot by kernel
2256 parameter cpu0_hotplug.
2257
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002258config DEBUG_HOTPLUG_CPU0
2259 def_bool n
2260 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002261 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002262 ---help---
2263 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2264 soon as possible and boots up userspace with CPU0 offlined. User
2265 can online CPU0 back after boot time.
2266
2267 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2268 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2269 compilation or giving cpu0_hotplug kernel parameter at boot.
2270
2271 If unsure, say N.
2272
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002273config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002274 def_bool n
2275 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002276 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002277 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002278 Certain buggy versions of glibc will crash if they are
2279 presented with a 32-bit vDSO that is not mapped at the address
2280 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002281
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002282 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2283 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2284 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2285 the only released version with the bug, but OpenSUSE 9
2286 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002287
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002288 The symptom of the bug is that everything crashes on startup, saying:
2289 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2290
2291 Saying Y here changes the default value of the vdso32 boot
2292 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2293 This works around the glibc bug but hurts performance.
2294
2295 If unsure, say N: if you are compiling your own kernel, you
2296 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002297
Kees Cook3dc33bd2015-08-12 17:55:19 -07002298choice
2299 prompt "vsyscall table for legacy applications"
2300 depends on X86_64
2301 default LEGACY_VSYSCALL_EMULATE
2302 help
2303 Legacy user code that does not know how to find the vDSO expects
2304 to be able to issue three syscalls by calling fixed addresses in
2305 kernel space. Since this location is not randomized with ASLR,
2306 it can be used to assist security vulnerability exploitation.
2307
2308 This setting can be changed at boot time via the kernel command
2309 line parameter vsyscall=[native|emulate|none].
2310
2311 On a system with recent enough glibc (2.14 or newer) and no
2312 static binaries, you can say None without a performance penalty
2313 to improve security.
2314
2315 If unsure, select "Emulate".
2316
2317 config LEGACY_VSYSCALL_NATIVE
2318 bool "Native"
2319 help
2320 Actual executable code is located in the fixed vsyscall
2321 address mapping, implementing time() efficiently. Since
2322 this makes the mapping executable, it can be used during
2323 security vulnerability exploitation (traditionally as
2324 ROP gadgets). This configuration is not recommended.
2325
2326 config LEGACY_VSYSCALL_EMULATE
2327 bool "Emulate"
2328 help
2329 The kernel traps and emulates calls into the fixed
2330 vsyscall address mapping. This makes the mapping
2331 non-executable, but it still contains known contents,
2332 which could be used in certain rare security vulnerability
2333 exploits. This configuration is recommended when userspace
2334 still uses the vsyscall area.
2335
2336 config LEGACY_VSYSCALL_NONE
2337 bool "None"
2338 help
2339 There will be no vsyscall mapping at all. This will
2340 eliminate any risk of ASLR bypass due to the vsyscall
2341 fixed address mapping. Attempts to use the vsyscalls
2342 will be reported to dmesg, so that either old or
2343 malicious userspace programs can be identified.
2344
2345endchoice
2346
Tim Bird516cbf32008-08-12 12:52:36 -07002347config CMDLINE_BOOL
2348 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002349 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002350 Allow for specifying boot arguments to the kernel at
2351 build time. On some systems (e.g. embedded ones), it is
2352 necessary or convenient to provide some or all of the
2353 kernel boot arguments with the kernel itself (that is,
2354 to not rely on the boot loader to provide them.)
2355
2356 To compile command line arguments into the kernel,
2357 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002358 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002359
2360 Systems with fully functional boot loaders (i.e. non-embedded)
2361 should leave this option set to 'N'.
2362
2363config CMDLINE
2364 string "Built-in kernel command string"
2365 depends on CMDLINE_BOOL
2366 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002367 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002368 Enter arguments here that should be compiled into the kernel
2369 image and used at boot time. If the boot loader provides a
2370 command line at boot time, it is appended to this string to
2371 form the full kernel command line, when the system boots.
2372
2373 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2374 change this behavior.
2375
2376 In most cases, the command line (whether built-in or provided
2377 by the boot loader) should specify the device for the root
2378 file system.
2379
2380config CMDLINE_OVERRIDE
2381 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002382 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002383 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002384 Set this option to 'Y' to have the kernel ignore the boot loader
2385 command line, and use ONLY the built-in command line.
2386
2387 This is used to work around broken boot loaders. This should
2388 be set to 'N' under normal conditions.
2389
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002390config MODIFY_LDT_SYSCALL
2391 bool "Enable the LDT (local descriptor table)" if EXPERT
2392 default y
2393 ---help---
2394 Linux can allow user programs to install a per-process x86
2395 Local Descriptor Table (LDT) using the modify_ldt(2) system
2396 call. This is required to run 16-bit or segmented code such as
2397 DOSEMU or some Wine programs. It is also used by some very old
2398 threading libraries.
2399
2400 Enabling this feature adds a small amount of overhead to
2401 context switches and increases the low-level kernel attack
2402 surface. Disabling it removes the modify_ldt(2) system call.
2403
2404 Saying 'N' here may make sense for embedded or server kernels.
2405
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002406source "kernel/livepatch/Kconfig"
2407
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002408endmenu
2409
Michal Hocko3072e412017-09-08 16:11:39 -07002410config ARCH_HAS_ADD_PAGES
2411 def_bool y
2412 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2413
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002414config ARCH_ENABLE_MEMORY_HOTPLUG
2415 def_bool y
2416 depends on X86_64 || (X86_32 && HIGHMEM)
2417
Gary Hade35551052008-10-31 10:52:03 -07002418config ARCH_ENABLE_MEMORY_HOTREMOVE
2419 def_bool y
2420 depends on MEMORY_HOTPLUG
2421
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002422config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002423 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002424 depends on NUMA
2425
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002426config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2427 def_bool y
2428 depends on X86_64 || X86_PAE
2429
Naoya Horiguchic177c812014-06-04 16:05:35 -07002430config ARCH_ENABLE_HUGEPAGE_MIGRATION
2431 def_bool y
2432 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2433
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002434config ARCH_ENABLE_THP_MIGRATION
2435 def_bool y
2436 depends on X86_64 && TRANSPARENT_HUGEPAGE
2437
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002438menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002439
2440config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002441 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002442 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002443
2444source "kernel/power/Kconfig"
2445
2446source "drivers/acpi/Kconfig"
2447
Feng Tangefafc8b2009-08-14 15:23:29 -04002448source "drivers/sfi/Kconfig"
2449
Andi Kleena6b68072008-01-30 13:32:49 +01002450config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002451 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002452 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002453
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002454menuconfig APM
2455 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002456 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002457 ---help---
2458 APM is a BIOS specification for saving power using several different
2459 techniques. This is mostly useful for battery powered laptops with
2460 APM compliant BIOSes. If you say Y here, the system time will be
2461 reset after a RESUME operation, the /proc/apm device will provide
2462 battery status information, and user-space programs will receive
2463 notification of APM "events" (e.g. battery status change).
2464
2465 If you select "Y" here, you can disable actual use of the APM
2466 BIOS by passing the "apm=off" option to the kernel at boot time.
2467
2468 Note that the APM support is almost completely disabled for
2469 machines with more than one CPU.
2470
2471 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002472 and more information, read <file:Documentation/power/apm-acpi.txt>
2473 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002474 <http://www.tldp.org/docs.html#howto>.
2475
2476 This driver does not spin down disk drives (see the hdparm(8)
2477 manpage ("man 8 hdparm") for that), and it doesn't turn off
2478 VESA-compliant "green" monitors.
2479
2480 This driver does not support the TI 4000M TravelMate and the ACER
2481 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2482 desktop machines also don't have compliant BIOSes, and this driver
2483 may cause those machines to panic during the boot phase.
2484
2485 Generally, if you don't have a battery in your machine, there isn't
2486 much point in using this driver and you should say N. If you get
2487 random kernel OOPSes or reboots that don't seem to be related to
2488 anything, try disabling/enabling this option (or disabling/enabling
2489 APM in your BIOS).
2490
2491 Some other things you should try when experiencing seemingly random,
2492 "weird" problems:
2493
2494 1) make sure that you have enough swap space and that it is
2495 enabled.
2496 2) pass the "no-hlt" option to the kernel
2497 3) switch on floating point emulation in the kernel and pass
2498 the "no387" option to the kernel
2499 4) pass the "floppy=nodma" option to the kernel
2500 5) pass the "mem=4M" option to the kernel (thereby disabling
2501 all but the first 4 MB of RAM)
2502 6) make sure that the CPU is not over clocked.
2503 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2504 8) disable the cache from your BIOS settings
2505 9) install a fan for the video card or exchange video RAM
2506 10) install a better fan for the CPU
2507 11) exchange RAM chips
2508 12) exchange the motherboard.
2509
2510 To compile this driver as a module, choose M here: the
2511 module will be called apm.
2512
2513if APM
2514
2515config APM_IGNORE_USER_SUSPEND
2516 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002517 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002518 This option will ignore USER SUSPEND requests. On machines with a
2519 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2520 series notebooks, it is necessary to say Y because of a BIOS bug.
2521
2522config APM_DO_ENABLE
2523 bool "Enable PM at boot time"
2524 ---help---
2525 Enable APM features at boot time. From page 36 of the APM BIOS
2526 specification: "When disabled, the APM BIOS does not automatically
2527 power manage devices, enter the Standby State, enter the Suspend
2528 State, or take power saving steps in response to CPU Idle calls."
2529 This driver will make CPU Idle calls when Linux is idle (unless this
2530 feature is turned off -- see "Do CPU IDLE calls", below). This
2531 should always save battery power, but more complicated APM features
2532 will be dependent on your BIOS implementation. You may need to turn
2533 this option off if your computer hangs at boot time when using APM
2534 support, or if it beeps continuously instead of suspending. Turn
2535 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2536 T400CDT. This is off by default since most machines do fine without
2537 this feature.
2538
2539config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002540 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002541 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002542 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002543 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2544 On some machines, this can activate improved power savings, such as
2545 a slowed CPU clock rate, when the machine is idle. These idle calls
2546 are made after the idle loop has run for some length of time (e.g.,
2547 333 mS). On some machines, this will cause a hang at boot time or
2548 whenever the CPU becomes idle. (On machines with more than one CPU,
2549 this option does nothing.)
2550
2551config APM_DISPLAY_BLANK
2552 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002553 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002554 Enable console blanking using the APM. Some laptops can use this to
2555 turn off the LCD backlight when the screen blanker of the Linux
2556 virtual console blanks the screen. Note that this is only used by
2557 the virtual console screen blanker, and won't turn off the backlight
2558 when using the X Window system. This also doesn't have anything to
2559 do with your VESA-compliant power-saving monitor. Further, this
2560 option doesn't work for all laptops -- it might not turn off your
2561 backlight at all, or it might print a lot of errors to the console,
2562 especially if you are using gpm.
2563
2564config APM_ALLOW_INTS
2565 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002566 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002567 Normally we disable external interrupts while we are making calls to
2568 the APM BIOS as a measure to lessen the effects of a badly behaving
2569 BIOS implementation. The BIOS should reenable interrupts if it
2570 needs to. Unfortunately, some BIOSes do not -- especially those in
2571 many of the newer IBM Thinkpads. If you experience hangs when you
2572 suspend, try setting this to Y. Otherwise, say N.
2573
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002574endif # APM
2575
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002576source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002577
2578source "drivers/cpuidle/Kconfig"
2579
Andy Henroid27471fd2008-10-09 11:45:22 -07002580source "drivers/idle/Kconfig"
2581
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002582endmenu
2583
2584
2585menu "Bus options (PCI etc.)"
2586
2587config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002588 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002589 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002590 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591 Find out whether you have a PCI motherboard. PCI is the name of a
2592 bus system, i.e. the way the CPU talks to the other stuff inside
2593 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2594 VESA. If you have PCI, say Y, otherwise N.
2595
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002596choice
2597 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002598 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002599 default PCI_GOANY
2600 ---help---
2601 On PCI systems, the BIOS can be used to detect the PCI devices and
2602 determine their configuration. However, some old PCI motherboards
2603 have BIOS bugs and may crash if this is done. Also, some embedded
2604 PCI-based systems don't have any BIOS at all. Linux can also try to
2605 detect the PCI hardware directly without using the BIOS.
2606
2607 With this option, you can specify how Linux should detect the
2608 PCI devices. If you choose "BIOS", the BIOS will be used,
2609 if you choose "Direct", the BIOS won't be used, and if you
2610 choose "MMConfig", then PCI Express MMCONFIG will be used.
2611 If you choose "Any", the kernel will try MMCONFIG, then the
2612 direct access method and falls back to the BIOS if that doesn't
2613 work. If unsure, go with the default, which is "Any".
2614
2615config PCI_GOBIOS
2616 bool "BIOS"
2617
2618config PCI_GOMMCONFIG
2619 bool "MMConfig"
2620
2621config PCI_GODIRECT
2622 bool "Direct"
2623
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002624config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002625 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002626 depends on OLPC
2627
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002628config PCI_GOANY
2629 bool "Any"
2630
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002631endchoice
2632
2633config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002634 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002635 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002636
2637# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2638config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002639 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002640 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002641
2642config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002643 bool "Support mmconfig PCI config space access" if X86_64
2644 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002645 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002646 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002647
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002648config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002649 def_bool y
2650 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002651
Alex Nixonb5401a92010-03-18 16:31:34 -04002652config PCI_XEN
2653 def_bool y
2654 depends on PCI && XEN
2655 select SWIOTLB_XEN
2656
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002657config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002658 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002659 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002660
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002661config MMCONF_FAM10H
2662 def_bool y
2663 depends on X86_64 && PCI_MMCONFIG && ACPI
2664
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002665config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002666 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002667 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002668 help
2669 Read the PCI windows out of the CNB20LE host bridge. This allows
2670 PCI hotplug to work on systems with the CNB20LE chipset which do
2671 not have ACPI.
2672
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002673 There's no public spec for this chipset, and this functionality
2674 is known to be incomplete.
2675
2676 You should say N unless you know you need this.
2677
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002678source "drivers/pci/Kconfig"
2679
William Breathitt Gray3a495512016-05-27 18:08:27 -04002680config ISA_BUS
2681 bool "ISA-style bus support on modern systems" if EXPERT
2682 select ISA_BUS_API
2683 help
2684 Enables ISA-style drivers on modern systems. This is necessary to
2685 support PC/104 devices on X86_64 platforms.
2686
2687 If unsure, say N.
2688
David Rientjes1c00f012011-03-22 16:34:59 -07002689# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002690config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002691 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2692 default y
2693 help
2694 Enables ISA-style DMA support for devices requiring such controllers.
2695 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002696
Linus Torvalds51e68d02016-05-21 10:25:19 -07002697if X86_32
2698
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002699config ISA
2700 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002701 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002702 Find out whether you have ISA slots on your motherboard. ISA is the
2703 name of a bus system, i.e. the way the CPU talks to the other stuff
2704 inside your box. Other bus systems are PCI, EISA, MicroChannel
2705 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2706 newer boards don't support it. If you have ISA, say Y, otherwise N.
2707
2708config EISA
2709 bool "EISA support"
2710 depends on ISA
2711 ---help---
2712 The Extended Industry Standard Architecture (EISA) bus was
2713 developed as an open alternative to the IBM MicroChannel bus.
2714
2715 The EISA bus provided some of the features of the IBM MicroChannel
2716 bus while maintaining backward compatibility with cards made for
2717 the older ISA bus. The EISA bus saw limited use between 1988 and
2718 1995 when it was made obsolete by the PCI bus.
2719
2720 Say Y here if you are building a kernel for an EISA-based machine.
2721
2722 Otherwise, say N.
2723
2724source "drivers/eisa/Kconfig"
2725
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726config SCx200
2727 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002728 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002729 This provides basic support for National Semiconductor's
2730 (now AMD's) Geode processors. The driver probes for the
2731 PCI-IDs of several on-chip devices, so its a good dependency
2732 for other scx200_* drivers.
2733
2734 If compiled as a module, the driver is named scx200.
2735
2736config SCx200HR_TIMER
2737 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002738 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002739 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002740 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002741 This driver provides a clocksource built upon the on-chip
2742 27MHz high-resolution timer. Its also a workaround for
2743 NSC Geode SC-1100's buggy TSC, which loses time when the
2744 processor goes idle (as is done by the scheduler). The
2745 other workaround is idle=poll boot option.
2746
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002747config OLPC
2748 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002749 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002750 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002751 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002752 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002753 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002754 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002755 Add support for detecting the unique features of the OLPC
2756 XO hardware.
2757
Daniel Drakea3128582011-06-25 17:34:10 +01002758config OLPC_XO1_PM
2759 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002760 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002761 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002762 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002763 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002764
Daniel Drakecfee9592011-06-25 17:34:17 +01002765config OLPC_XO1_RTC
2766 bool "OLPC XO-1 Real Time Clock"
2767 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2768 ---help---
2769 Add support for the XO-1 real time clock, which can be used as a
2770 programmable wakeup source.
2771
Daniel Drake7feda8e2011-06-25 17:34:12 +01002772config OLPC_XO1_SCI
2773 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002774 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002775 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002776 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002777 select GPIO_CS5535
2778 select MFD_CORE
2779 ---help---
2780 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002781 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002782 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002783 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002784 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002785 - AC adapter status updates
2786 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002787
Daniel Drakea0f30f52011-06-25 17:34:18 +01002788config OLPC_XO15_SCI
2789 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002790 depends on OLPC && ACPI
2791 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002792 ---help---
2793 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2794 - EC-driven system wakeups
2795 - AC adapter status updates
2796 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002797
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002798config ALIX
2799 bool "PCEngines ALIX System Support (LED setup)"
2800 select GPIOLIB
2801 ---help---
2802 This option enables system support for the PCEngines ALIX.
2803 At present this just sets up LEDs for GPIO control on
2804 ALIX2/3/6 boards. However, other system specific setup should
2805 get added here.
2806
2807 Note: You must still enable the drivers for GPIO and LED support
2808 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2809
2810 Note: You have to set alix.force=1 for boards with Award BIOS.
2811
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002812config NET5501
2813 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2814 select GPIOLIB
2815 ---help---
2816 This option enables system support for the Soekris Engineering net5501.
2817
Philip A. Prindeville31970592012-01-14 01:45:39 -07002818config GEOS
2819 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2820 select GPIOLIB
2821 depends on DMI
2822 ---help---
2823 This option enables system support for the Traverse Technologies GEOS.
2824
Vivien Didelot7d029122013-01-04 16:18:14 -05002825config TS5500
2826 bool "Technologic Systems TS-5500 platform support"
2827 depends on MELAN
2828 select CHECK_SIGNATURE
2829 select NEW_LEDS
2830 select LEDS_CLASS
2831 ---help---
2832 This option enables system support for the Technologic Systems TS-5500.
2833
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002834endif # X86_32
2835
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002836config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002837 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002838 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002839
2840source "drivers/pcmcia/Kconfig"
2841
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002842config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002843 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002844 depends on PCI
2845 default n
2846 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002847 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002848 infrastructure code to support RapidIO interconnect devices.
2849
2850source "drivers/rapidio/Kconfig"
2851
David Herrmanne3263ab2013-08-02 14:05:22 +02002852config X86_SYSFB
2853 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2854 help
2855 Firmwares often provide initial graphics framebuffers so the BIOS,
2856 bootloader or kernel can show basic video-output during boot for
2857 user-guidance and debugging. Historically, x86 used the VESA BIOS
2858 Extensions and EFI-framebuffers for this, which are mostly limited
2859 to x86.
2860 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2861 framebuffers so the new generic system-framebuffer drivers can be
2862 used on x86. If the framebuffer is not compatible with the generic
2863 modes, it is adverticed as fallback platform framebuffer so legacy
2864 drivers like efifb, vesafb and uvesafb can pick it up.
2865 If this option is not selected, all system framebuffers are always
2866 marked as fallback platform framebuffers as usual.
2867
2868 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2869 not be able to pick up generic system framebuffers if this option
2870 is selected. You are highly encouraged to enable simplefb as
2871 replacement if you select this option. simplefb can correctly deal
2872 with generic system framebuffers. But you should still keep vesafb
2873 and others enabled as fallback if a system framebuffer is
2874 incompatible with simplefb.
2875
2876 If unsure, say Y.
2877
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002878endmenu
2879
2880
2881menu "Executable file formats / Emulations"
2882
2883source "fs/Kconfig.binfmt"
2884
2885config IA32_EMULATION
2886 bool "IA32 Emulation"
2887 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002888 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002889 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002890 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002891 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002892 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002893 Include code to run legacy 32-bit programs under a
2894 64-bit kernel. You should likely turn this on, unless you're
2895 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002896
2897config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002898 tristate "IA32 a.out support"
2899 depends on IA32_EMULATION
2900 ---help---
2901 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002902
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002903config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002904 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002905 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002906 ---help---
2907 Include code to run binaries for the x32 native 32-bit ABI
2908 for 64-bit processors. An x32 process gets access to the
2909 full 64-bit register file and wide data path while leaving
2910 pointers at 32 bits for smaller memory footprint.
2911
2912 You will need a recent binutils (2.22 or later) with
2913 elf32_x86_64 support enabled to compile a kernel with this
2914 option set.
2915
Ingo Molnar953fee12016-11-15 10:22:52 +01002916config COMPAT_32
2917 def_bool y
2918 depends on IA32_EMULATION || X86_32
2919 select HAVE_UID16
2920 select OLD_SIGSUSPEND3
2921
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002922config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002923 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002924 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002925
Jan Beulich3120e252012-09-10 12:41:45 +01002926if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002927config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002928 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002929
2930config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002931 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002932 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002933endif
David Howellsee009e4a02011-03-07 15:06:20 +00002934
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002935endmenu
2936
2937
Keith Packarde5beae12008-11-03 18:21:45 +01002938config HAVE_ATOMIC_IOMAP
2939 def_bool y
2940 depends on X86_32
2941
Alessandro Rubini4692d772012-04-04 19:39:58 +02002942config X86_DEV_DMA_OPS
2943 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002944 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002945
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002946config X86_DMA_REMAP
2947 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002948 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002949
Kirill A. Shutemove5855132017-06-06 14:31:20 +03002950config HAVE_GENERIC_GUP
2951 def_bool y
2952
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002953source "net/Kconfig"
2954
2955source "drivers/Kconfig"
2956
2957source "drivers/firmware/Kconfig"
2958
2959source "fs/Kconfig"
2960
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002961source "arch/x86/Kconfig.debug"
2962
2963source "security/Kconfig"
2964
2965source "crypto/Kconfig"
2966
Avi Kivityedf88412007-12-16 11:02:48 +02002967source "arch/x86/kvm/Kconfig"
2968
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002969source "lib/Kconfig"