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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
Masahiro Yamada104daea2018-05-28 18:21:40 +09004 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(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
Thomas Gleixner117ed452019-04-14 18:00:08 +020017 select HAVE_DEBUG_STACKOVERFLOW
Ingo Molnar341c7872016-11-15 10:04:55 +010018 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
Vincenzo Frascino7ac87072019-06-21 10:52:49 +010020 select GENERIC_VDSO_32
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:
Alexandre Ghiti4eb07162019-05-13 17:19:04 -070026 select ARCH_HAS_GIGANTIC_PAGE
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
Christoph Hellwigf616ab52018-05-09 06:53:49 +020031 select NEED_DMA_MAP_STATE
Christoph Hellwig09230cb2018-04-24 09:00:54 +020032 select SWIOTLB
Dominik Brodowskif8781c42018-04-05 11:53:05 +020033 select ARCH_HAS_SYSCALL_WRAPPER
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010034
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040035config FORCE_DYNAMIC_FTRACE
36 def_bool y
37 depends on X86_32
38 depends on FUNCTION_TRACER
39 select DYNAMIC_FTRACE
40 help
41 We keep the static function tracing (!DYNAMIC_FTRACE) around
42 in order to test the non static function tracing in the
43 generic code, as other architectures still use it. But we
44 only need to keep it around for x86_64. No need to keep it
45 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010046#
47# Arch settings
48#
49# ( Note that options that are marked 'if X86_64' could in principle be
50# ported to 32-bit as well. )
51#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010052config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010053 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010054 #
55 # Note: keep this list sorted alphabetically
56 #
Ingo Molnar6471b822015-06-03 10:00:13 +020057 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030059 select ARCH_32BIT_OFF_T if X86_32
Ingo Molnar6471b822015-06-03 10:00:13 +020060 select ARCH_CLOCKSOURCE_DATA
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020061 select ARCH_CLOCKSOURCE_INIT
Ingo Molnarc763ea22016-11-15 10:26:39 +010062 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080063 select ARCH_HAS_DEBUG_VIRTUAL
Dan Williams21266be2015-11-19 18:19:29 -080064 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020065 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070066 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070067 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070068 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080069 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070070 select ARCH_HAS_KCOV if X86_64
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050071 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Ingo Molnarc763ea22016-11-15 10:26:39 +010072 select ARCH_HAS_PMEM_API if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070073 select ARCH_HAS_PTE_SPECIAL
Kees Cook39208aa2017-09-02 13:09:46 -070074 select ARCH_HAS_REFCOUNT
Dan Williams0aed55a2017-05-29 12:22:50 -070075 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070076 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010077 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070078 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080079 select ARCH_HAS_STRICT_KERNEL_RWX
80 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050081 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Andrey Ryabininc6d30852016-01-20 15:00:55 -080082 select ARCH_HAS_UBSAN_SANITIZE_ALL
Oliver O'Halloran65f7d042017-06-28 11:32:31 +100083 select ARCH_HAS_ZONE_DEVICE if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020084 select ARCH_HAVE_NMI_SAFE_CMPXCHG
85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040086 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080087 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020088 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020089 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
92 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020093 select ARCH_USE_QUEUED_RWLOCKS
94 select ARCH_USE_QUEUED_SPINLOCKS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070095 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Ingo Molnarc763ea22016-11-15 10:26:39 +010096 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Huang Ying38d8b4e2017-07-06 15:37:18 -070097 select ARCH_WANTS_THP_SWAP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020098 select BUILDTIME_EXTABLE_SORT
99 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
101 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700103 select EDAC_ATOMIC_SCRUB
104 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200105 select GENERIC_CLOCKEVENTS
106 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
107 select GENERIC_CLOCKEVENTS_MIN_ADJUST
108 select GENERIC_CMOS_UPDATE
109 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100110 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select GENERIC_EARLY_IOREMAP
112 select GENERIC_FIND_FIRST_BIT
113 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200114 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200115 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200116 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200117 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200118 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select GENERIC_IRQ_SHOW
120 select GENERIC_PENDING_IRQ if SMP
121 select GENERIC_SMP_IDLE_THREAD
122 select GENERIC_STRNCPY_FROM_USER
123 select GENERIC_STRNLEN_USER
124 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100125 select GENERIC_GETTIMEOFDAY
Christoph Hellwig39656e82019-07-11 20:56:49 -0700126 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200127 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200128 select HAVE_ACPI_APEI if ACPI
129 select HAVE_ACPI_APEI_NMI if ACPI
130 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200131 select HAVE_ARCH_AUDITSYSCALL
132 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
133 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700134 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800135 select HAVE_ARCH_KASAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200136 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800137 select HAVE_ARCH_MMAP_RND_BITS if MMU
138 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300139 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700140 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200141 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700142 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300143 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_ARCH_TRACEHOOK
145 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800146 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700147 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100148 select HAVE_ARCH_WITHIN_STACK_FRAMES
Ingo Molnar6471b822015-06-03 10:00:13 +0200149 select HAVE_CMPXCHG_DOUBLE
150 select HAVE_CMPXCHG_LOCAL
151 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700152 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200153 select HAVE_C_RECORDMCOUNT
154 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700155 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400156 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900157 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Wang YanQing03f57812018-05-03 14:10:43 +0800158 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700159 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100160 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700161 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700162 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400163 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200164 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200165 select HAVE_FUNCTION_GRAPH_TRACER
166 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200167 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530168 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200169 select HAVE_IDE
170 select HAVE_IOREMAP_PROT
171 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
172 select HAVE_IRQ_TIME_ACCOUNTING
173 select HAVE_KERNEL_BZIP2
174 select HAVE_KERNEL_GZIP
175 select HAVE_KERNEL_LZ4
176 select HAVE_KERNEL_LZMA
177 select HAVE_KERNEL_LZO
178 select HAVE_KERNEL_XZ
179 select HAVE_KPROBES
180 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900181 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200182 select HAVE_KRETPROBES
183 select HAVE_KVM
184 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200185 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200186 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500187 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800188 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700189 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200190 select HAVE_OPROFILE
191 select HAVE_OPTPROBES
192 select HAVE_PCSPKR_PLATFORM
193 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200194 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700195 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100196 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200197 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200198 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstra48a8b972018-08-22 17:30:16 +0200199 select HAVE_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200200 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200201 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900202 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900203 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100204 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400205 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200206 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200207 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300208 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100209 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200210 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100211 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200212 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100213 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000214 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200215 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500216 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200217 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200218 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500219 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200220 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700221 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200222 select USER_STACKTRACE_SUPPORT
223 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200224 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800225 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530226
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200227config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100228 def_bool y
229 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200230
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700231config OUTPUT_FORMAT
232 string
233 default "elf32-i386" if X86_32
234 default "elf64-x86-64" if X86_64
235
Sam Ravnborg73531902008-05-25 23:03:18 +0200236config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200237 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200238 default "arch/x86/configs/i386_defconfig" if X86_32
239 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200240
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100241config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100242 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100243
244config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100245 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100246
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100247config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100248 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100249
Daniel Cashman9e08f572016-01-14 15:20:06 -0800250config ARCH_MMAP_RND_BITS_MIN
251 default 28 if 64BIT
252 default 8
253
254config ARCH_MMAP_RND_BITS_MAX
255 default 32 if 64BIT
256 default 16
257
258config ARCH_MMAP_RND_COMPAT_BITS_MIN
259 default 8
260
261config ARCH_MMAP_RND_COMPAT_BITS_MAX
262 default 16
263
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100264config SBUS
265 bool
266
267config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100268 def_bool y
269 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100270
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100271config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100272 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100273 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000274 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
275
276config GENERIC_BUG_RELATIVE_POINTERS
277 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100278
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100279config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100280 def_bool y
281 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100282
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100283config GENERIC_CALIBRATE_DELAY
284 def_bool y
285
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800286config ARCH_HAS_CPU_RELAX
287 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100288
Pekka Enberg1b27d052008-04-28 02:12:22 -0700289config ARCH_HAS_CACHE_LINE_SIZE
290 def_bool y
291
Dave Hansen316d0972018-04-20 15:20:28 -0700292config ARCH_HAS_FILTER_PGPROT
293 def_bool y
294
Mike Travisdd5af902008-01-30 13:33:32 +0100295config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900296 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100297
Tejun Heo08fc4582009-08-14 15:00:49 +0900298config NEED_PER_CPU_EMBED_FIRST_CHUNK
299 def_bool y
300
301config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900302 def_bool y
303
Johannes Berg801e4062007-12-08 02:12:39 +0100304config ARCH_HIBERNATION_POSSIBLE
305 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100306
Johannes Bergf4cb5702007-12-08 02:14:00 +0100307config ARCH_SUSPEND_POSSIBLE
308 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100309
Steve Cappercfe28c52013-04-29 14:29:48 +0100310config ARCH_WANT_HUGE_PMD_SHARE
311 def_bool y
312
Steve Capper53313b22013-04-30 08:03:42 +0100313config ARCH_WANT_GENERAL_HUGETLB
314 def_bool y
315
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100316config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000317 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100318
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100319config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000320 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321
Akinobu Mita6a11f752009-03-31 15:23:17 -0700322config ARCH_SUPPORTS_DEBUG_PAGEALLOC
323 def_bool y
324
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300325config KASAN_SHADOW_OFFSET
326 hex
327 depends on KASAN
328 default 0xdffffc0000000000
329
Shane Wang69575d32009-09-01 18:25:07 -0700330config HAVE_INTEL_TXT
331 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700332 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700333
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100334config X86_32_SMP
335 def_bool y
336 depends on X86_32 && SMP
337
338config X86_64_SMP
339 def_bool y
340 depends on X86_64 && SMP
341
Tejun Heoccbeed32009-02-09 22:17:40 +0900342config X86_32_LAZY_GS
343 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900344 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900345
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530346config ARCH_SUPPORTS_UPROBES
347 def_bool y
348
Rob Herringd20642f2014-04-18 17:19:54 -0500349config FIX_EARLYCON_MEM
350 def_bool y
351
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300352config DYNAMIC_PHYSICAL_MASK
353 bool
354
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700355config PGTABLE_LEVELS
356 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300357 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700358 default 4 if X86_64
359 default 3 if X86_PAE
360 default 2
361
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900362config CC_HAS_SANE_STACKPROTECTOR
363 bool
364 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
365 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
366 help
367 We have to make sure stack protector is unconditionally disabled if
368 the compiler produces broken code.
369
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100370menu "Processor type and features"
371
Randy Dunlap5ee71532012-01-16 11:57:18 -0800372config ZONE_DMA
373 bool "DMA memory allocation support" if EXPERT
374 default y
375 help
376 DMA memory allocation support allows devices with less than 32-bit
377 addressing to allocate within the first 16MB of address space.
378 Disable if no such devices will be used.
379
380 If unsure, say Y.
381
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100382config SMP
383 bool "Symmetric multi-processing support"
384 ---help---
385 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800386 a system with only one CPU, say N. If you have a system with more
387 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100388
Robert Graffham4a474152014-01-23 15:55:29 -0800389 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100390 machines, but will use only one CPU of a multiprocessor machine. If
391 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800392 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100393 will run faster if you say N here.
394
395 Note that if you say Y here and choose architecture "586" or
396 "Pentium" under "Processor family", the kernel will not work on 486
397 architectures. Similarly, multiprocessor kernels for the "PPro"
398 architecture may not work on all Pentium based boards.
399
400 People using multiprocessor machines who say Y here should also say
401 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
402 Management" code will be disabled if you say Y here.
403
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300404 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Benjamin Petersonc9525a32017-05-20 17:20:16 -0700405 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100406 <http://www.tldp.org/docs.html#howto>.
407
408 If you don't know what to do here, say N.
409
Josh Triplett9def39be2013-10-30 08:09:45 -0700410config X86_FEATURE_NAMES
411 bool "Processor feature human-readable names" if EMBEDDED
412 default y
413 ---help---
414 This option compiles in a table of x86 feature bits and corresponding
415 names. This is required to support /proc/cpuinfo and a few kernel
416 messages. You can disable this to save space, at the expense of
417 making those few kernel messages show numeric feature bits instead.
418
419 If in doubt, say Y.
420
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800421config X86_X2APIC
422 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200423 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800424 ---help---
425 This enables x2apic support on CPUs that have this feature.
426
427 This allows 32-bit apic IDs (so it can support very large systems),
428 and accesses the local apic via MSRs not via mmio.
429
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800430 If you don't know what to do here, say N.
431
Yinghai Lu6695c852008-06-19 12:13:09 -0700432config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700433 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000434 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200435 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100436 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700437 For old smp systems that do not have proper acpi support. Newer systems
438 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700439
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000440config GOLDFISH
441 def_bool y
442 depends on X86_GOLDFISH
443
David Woodhouse76b04382018-01-11 21:46:25 +0000444config RETPOLINE
445 bool "Avoid speculative indirect branches in kernel"
446 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100447 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000448 help
449 Compile kernel with the retpoline compiler options to guard against
450 kernel-to-user data leaks by avoiding speculative indirect
451 branches. Requires a compiler with -mindirect-branch=thunk-extern
452 support for full protection. The kernel may run slower.
453
Johannes Weinere6d42932019-01-29 17:44:36 -0500454config X86_CPU_RESCTRL
455 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000456 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100457 select KERNFS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700458 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500459 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000460
461 Provide support for the allocation and monitoring of system resources
462 usage by the CPU.
463
464 Intel calls this Intel Resource Director Technology
465 (Intel(R) RDT). More information about RDT can be found in the
466 Intel x86 Architecture Software Developer Manual.
467
468 AMD calls this AMD Platform Quality of Service (AMD QoS).
469 More information about AMD QoS can be found in the AMD64 Technology
470 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700471
472 Say N if unsure.
473
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800474if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800475config X86_BIGSMP
476 bool "Support for big SMP systems with more than 8 CPUs"
477 depends on SMP
478 ---help---
479 This option is needed for the systems that have more than 8 CPUs
480
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800481config X86_EXTENDED_PLATFORM
482 bool "Support for extended (non-PC) x86 platforms"
483 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100484 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100485 If you disable this option then the kernel will only support
486 standard PC platforms. (which covers the vast majority of
487 systems out there.)
488
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800489 If you enable this option then you'll be able to select support
490 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100491 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800492 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800493 RDC R-321x SoC
494 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200495 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200496 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100497
498 If you have one of these systems, or if you want to build a
499 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800500endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100501
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800502if X86_64
503config X86_EXTENDED_PLATFORM
504 bool "Support for extended (non-PC) x86 platforms"
505 default y
506 ---help---
507 If you disable this option then the kernel will only support
508 standard PC platforms. (which covers the vast majority of
509 systems out there.)
510
511 If you enable this option then you'll be able to select support
512 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800513 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800514 ScaleMP vSMP
515 SGI Ultraviolet
516
517 If you have one of these systems, or if you want to build a
518 generic distribution kernel, say Y here - otherwise say N.
519endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800520# This is an alphabetically sorted list of 64 bit extended platforms
521# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800522config X86_NUMACHIP
523 bool "Numascale NumaChip"
524 depends on X86_64
525 depends on X86_EXTENDED_PLATFORM
526 depends on NUMA
527 depends on SMP
528 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700529 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800530 ---help---
531 Adds support for Numascale NumaChip large-SMP systems. Needed to
532 enable more than ~168 cores.
533 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100534
Ingo Molnar6a485652009-01-27 18:29:13 +0100535config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800536 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100537 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100538 select PARAVIRT
539 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800540 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300541 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100542 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100543 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
544 supposed to run on these EM64T-based machines. Only choose this option
545 if you have one of these machines.
546
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800547config X86_UV
548 bool "SGI Ultraviolet"
549 depends on X86_64
550 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500551 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800552 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700553 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200554 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800555 ---help---
556 This option is needed in order to support SGI Ultraviolet systems.
557 If you don't have one of these, you should say N here.
558
559# Following is an alphabetically sorted list of 32 bit extended platforms
560# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100561
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000562config X86_GOLDFISH
563 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100564 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000565 ---help---
566 Enable support for the Goldfish virtual platform used primarily
567 for Android development. Unless you are building for the Android
568 Goldfish emulator say N here.
569
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800570config X86_INTEL_CE
571 bool "CE4100 TV platform"
572 depends on PCI
573 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800574 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800575 depends on X86_32
576 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800577 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100578 select OF
579 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800580 ---help---
581 Select for the Intel CE media processor (CE4100) SOC.
582 This option compiles in support for the CE4100 SOC for settop
583 boxes and media devices.
584
David Cohen4cb9b002013-12-16 17:37:26 -0800585config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100586 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100587 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800588 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000589 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200590 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000591 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000592 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800593 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000594 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000595 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000596 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000597 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000598 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800599 Select to build a kernel capable of supporting Intel MID (Mobile
600 Internet Device) platform systems which do not have the PCI legacy
601 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000602
David Cohen4cb9b002013-12-16 17:37:26 -0800603 Intel MID platforms are based on an Intel processor and chipset which
604 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100605
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000606config X86_INTEL_QUARK
607 bool "Intel Quark platform support"
608 depends on X86_32
609 depends on X86_EXTENDED_PLATFORM
610 depends on X86_PLATFORM_DEVICES
611 depends on X86_TSC
612 depends on PCI
613 depends on PCI_GOANY
614 depends on X86_IO_APIC
615 select IOSF_MBI
616 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200617 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000618 ---help---
619 Select to include support for Quark X1000 SoC.
620 Say Y here if you have a Quark based system such as the Arduino
621 compatible Intel Galileo.
622
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000623config X86_INTEL_LPSS
624 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000625 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000626 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300627 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100628 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000629 ---help---
630 Select to build support for Intel Low Power Subsystem such as
631 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300632 things like clock tree (common clock framework) and pincontrol
633 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000634
Ken Xue92082a82015-02-06 08:27:51 +0800635config X86_AMD_PLATFORM_DEVICE
636 bool "AMD ACPI2Platform devices support"
637 depends on ACPI
638 select COMMON_CLK
639 select PINCTRL
640 ---help---
641 Select to interpret AMD specific ACPI device to platform device
642 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
643 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
644 implemented under PINCTRL subsystem.
645
David E. Boxced3ce72014-09-17 22:13:50 -0700646config IOSF_MBI
647 tristate "Intel SoC IOSF Sideband support for SoC platforms"
648 depends on PCI
649 ---help---
650 This option enables sideband register access support for Intel SoC
651 platforms. On these platforms the IOSF sideband is used in lieu of
652 MSR's for some register accesses, mostly but not limited to thermal
653 and power. Drivers may query the availability of this device to
654 determine if they need the sideband in order to work on these
655 platforms. The sideband is available on the following SoC products.
656 This list is not meant to be exclusive.
657 - BayTrail
658 - Braswell
659 - Quark
660
661 You should say Y if you are running a kernel on one of these SoC's.
662
David E. Boxed2226b2014-09-17 22:13:51 -0700663config IOSF_MBI_DEBUG
664 bool "Enable IOSF sideband access through debugfs"
665 depends on IOSF_MBI && DEBUG_FS
666 ---help---
667 Select this option to expose the IOSF sideband access registers (MCR,
668 MDR, MCRX) through debugfs to write and read register information from
669 different units on the SoC. This is most useful for obtaining device
670 state information for debug and analysis. As this is a general access
671 mechanism, users of this option would have specific knowledge of the
672 device they want to access.
673
674 If you don't require the option or are in doubt, say N.
675
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800676config X86_RDC321X
677 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100678 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800679 depends on X86_EXTENDED_PLATFORM
680 select M486
681 select X86_REBOOTFIXUPS
682 ---help---
683 This option is needed for RDC R-321x system-on-chip, also known
684 as R-8610-(G).
685 If you don't have one of these chips, you should say N here.
686
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100687config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100688 bool "Support non-standard 32-bit SMP architectures"
689 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800690 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100691 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800692 This option compiles in the bigsmp and STA2X11 default
693 subarchitectures. It is intended for a generic binary
694 kernel. If you select them all, kernel will probe it one by
695 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700696
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800697# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700698
Linus Torvaldsd949f362009-09-26 09:35:07 -0700699config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100700 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700701 # MCE code calls memory_failure():
702 depends on X86_MCE
703 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700704 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
705 depends on X86_64 || !SPARSEMEM
706 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700707
Alessandro Rubini83125a32012-04-04 19:40:21 +0200708config STA2X11
709 bool "STA2X11 Companion Chip Support"
710 depends on X86_32_NON_STANDARD && PCI
Christoph Hellwigb6e05472018-03-19 11:38:24 +0100711 select ARCH_HAS_PHYS_TO_DMA
Alessandro Rubini83125a32012-04-04 19:40:21 +0200712 select SWIOTLB
713 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200714 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200715 ---help---
716 This adds support for boards based on the STA2X11 IO-Hub,
717 a.k.a. "ConneXt". The chip is used in place of the standard
718 PC chipset, so all "standard" peripherals are missing. If this
719 option is selected the kernel will still be able to boot on
720 standard PC machines.
721
Shérab82148d12010-09-25 06:06:57 +0200722config X86_32_IRIS
723 tristate "Eurobraille/Iris poweroff module"
724 depends on X86_32
725 ---help---
726 The Iris machines from EuroBraille do not have APM or ACPI support
727 to shut themselves down properly. A special I/O sequence is
728 needed to do so, which is what this module does at
729 kernel shutdown.
730
731 This is only for Iris machines from EuroBraille.
732
733 If unused, say N.
734
Ingo Molnarae1e9132008-11-11 09:05:16 +0100735config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100736 def_bool y
737 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800738 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100739 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100740 Calculate simpler /proc/<PID>/wchan values. If this option
741 is disabled then wchan values will recurse back to the
742 caller function. This provides more accurate wchan values,
743 at the expense of slightly more scheduling overhead.
744
745 If in doubt, say "Y".
746
Borislav Petkov6276a072013-03-04 21:20:21 +0100747menuconfig HYPERVISOR_GUEST
748 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100749 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100750 Say Y here to enable options for running Linux under various hyper-
751 visors. This option enables basic hypervisor detection and platform
752 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100753
Borislav Petkov6276a072013-03-04 21:20:21 +0100754 If you say N, all options in this submenu will be skipped and
755 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100756
Borislav Petkov6276a072013-03-04 21:20:21 +0100757if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100758
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100759config PARAVIRT
760 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100761 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100762 This changes the kernel so it can modify itself when it is run
763 under a hypervisor, potentially improving performance significantly
764 over full virtualization. However, when run without a hypervisor
765 the kernel is theoretically slower and slightly larger.
766
Juergen Grossc00a2802018-08-28 09:40:21 +0200767config PARAVIRT_XXL
768 bool
769
Borislav Petkov6276a072013-03-04 21:20:21 +0100770config PARAVIRT_DEBUG
771 bool "paravirt-ops debugging"
772 depends on PARAVIRT && DEBUG_KERNEL
773 ---help---
774 Enable to debug paravirt_ops internals. Specifically, BUG if
775 a paravirt_op is missing when it is called.
776
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700777config PARAVIRT_SPINLOCKS
778 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700779 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700780 ---help---
781 Paravirtualized spinlocks allow a pvops backend to replace the
782 spinlock implementation with something virtualization-friendly
783 (for example, block the virtual CPU rather than spinning).
784
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530785 It has a minimal impact on native kernels and gives a nice performance
786 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700787
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530788 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700789
Zhao Yakuiecca25022019-04-30 11:45:23 +0800790config X86_HV_CALLBACK_VECTOR
791 def_bool n
792
Borislav Petkov6276a072013-03-04 21:20:21 +0100793source "arch/x86/xen/Kconfig"
794
795config KVM_GUEST
796 bool "KVM Guest support (including kvmclock)"
797 depends on PARAVIRT
798 select PARAVIRT_CLOCK
799 default y
800 ---help---
801 This option enables various optimizations for running under the KVM
802 hypervisor. It includes a paravirtualized clock, so that instead
803 of relying on a PIT (or probably other) emulation by the
804 underlying device model, the host provides the guest with
805 timing infrastructure such as time of day, and system time
806
Maran Wilson77336072018-12-10 11:07:28 -0800807config PVH
808 bool "Support for running PVH guests"
809 ---help---
810 This option enables the PVH entry point for guest virtual machines
811 as specified in the x86/HVM direct boot ABI.
812
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530813config KVM_DEBUG_FS
814 bool "Enable debug information for KVM Guests in debugfs"
815 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530816 ---help---
817 This option enables collection of various statistics for KVM guest.
818 Statistics are displayed in debugfs filesystem. Enabling this option
819 may incur significant overhead.
820
Borislav Petkov6276a072013-03-04 21:20:21 +0100821config PARAVIRT_TIME_ACCOUNTING
822 bool "Paravirtual steal time accounting"
823 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100824 ---help---
825 Select this option to enable fine granularity task steal time
826 accounting. Time spent executing other tasks in parallel with
827 the current vCPU is discounted from the vCPU power. To account for
828 that, there can be a small performance impact.
829
830 If in doubt, say N here.
831
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200832config PARAVIRT_CLOCK
833 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200834
Jan Kiszka4a362602017-11-27 09:11:46 +0100835config JAILHOUSE_GUEST
836 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100837 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100838 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100839 ---help---
840 This option allows to run Linux as guest in a Jailhouse non-root
841 cell. You can leave this option disabled if you only want to start
842 Jailhouse and run Linux afterwards in the root cell.
843
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800844config ACRN_GUEST
845 bool "ACRN Guest support"
846 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800847 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800848 help
849 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
850 a flexible, lightweight reference open-source hypervisor, built with
851 real-time and safety-criticality in mind. It is built for embedded
852 IOT with small footprint and real-time features. More details can be
853 found in https://projectacrn.org/.
854
Borislav Petkov6276a072013-03-04 21:20:21 +0100855endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400856
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100857source "arch/x86/Kconfig.cpu"
858
859config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100860 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100861 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100862 ---help---
863 Use the IA-PC HPET (High Precision Event Timer) to manage
864 time in preference to the PIT and RTC, if a HPET is
865 present.
866 HPET is the next generation timer replacing legacy 8254s.
867 The HPET provides a stable time base on SMP
868 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200869 as it is off-chip. The interface used is documented
870 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100871
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100872 You can safely choose Y here. However, HPET will only be
873 activated if the platform and the BIOS support this feature.
874 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100875
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100876 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100877
878config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100879 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800880 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100881
Jacob Panbb24c472009-09-02 07:37:17 -0700882config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000883 def_bool y if X86_INTEL_MID
884 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100885 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000886 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700887 help
888 APB timer is the replacement for 8254, HPET on X86 MID platforms.
889 The APBT provides a stable time base on SMP
890 systems, unlike the TSC, but it is more expensive to access,
891 as it is off-chip. APB timers are always running regardless of CPU
892 C states, they are used as per CPU clockevent device when possible.
893
David Rientjes6a108a12011-01-20 14:44:16 -0800894# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100895# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700896config DMI
897 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800898 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800899 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100900 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700901 Enabled scanning of DMI to identify machine quirks. Say Y
902 here unless you have verified that your setup is not
903 affected by entries in the DMI blacklist. Required by PNP
904 BIOS code.
905
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100906config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700907 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200908 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100909 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200910 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100911 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200912 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
913 GART based hardware IOMMUs.
914
915 The GART supports full DMA access for devices with 32-bit access
916 limitations, on systems with more than 3 GB. This is usually needed
917 for USB, sound, many IDE/SATA chipsets and some other devices.
918
919 Newer systems typically have a modern AMD IOMMU, supported via
920 the CONFIG_AMD_IOMMU=y config option.
921
922 In normal configurations this driver is only active when needed:
923 there's more than 3 GB of memory and the system contains a
924 32-bit limited device.
925
926 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100927
928config CALGARY_IOMMU
929 bool "IBM Calgary IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200930 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100931 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700932 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100933 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100934 Support for hardware IOMMUs in IBM's xSeries x366 and x460
935 systems. Needed to run systems with more than 3GB of memory
936 properly with 32-bit PCI devices that do not support DAC
937 (Double Address Cycle). Calgary also supports bus level
938 isolation, where all DMAs pass through the IOMMU. This
939 prevents them from going anywhere except their intended
940 destination. This catches hard-to-find kernel bugs and
941 mis-behaving drivers and devices that do not use the DMA-API
942 properly to set up their DMA buffers. The IOMMU can be
943 turned off at boot time with the iommu=off parameter.
944 Normally the kernel will make the right choice by itself.
945 If unsure, say Y.
946
947config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100948 def_bool y
949 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100950 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100951 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100952 Should Calgary be enabled by default? if you choose 'y', Calgary
953 will be used (if it exists). If you choose 'n', Calgary will not be
954 used even if it exists. If you choose 'n' and would like to use
955 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
956 If unsure, say Y.
957
Mike Travis1184dc22008-05-12 21:21:12 +0200958config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200959 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700960 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800961 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100962 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200963 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200964 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100965
Ingo Molnaraec64872018-02-10 12:36:29 +0100966#
967# The maximum number of CPUs supported:
968#
969# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
970# and which can be configured interactively in the
971# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
972#
973# The ranges are different on 32-bit and 64-bit kernels, depending on
974# hardware capabilities and scalability features of the kernel.
975#
976# ( If MAXSMP is enabled we just use the highest possible value and disable
977# interactive configuration. )
978#
979
980config NR_CPUS_RANGE_BEGIN
981 int
982 default NR_CPUS_RANGE_END if MAXSMP
983 default 1 if !SMP
984 default 2
985
986config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800987 int
988 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100989 default 64 if SMP && X86_BIGSMP
990 default 8 if SMP && !X86_BIGSMP
991 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800992
Ingo Molnaraec64872018-02-10 12:36:29 +0100993config NR_CPUS_RANGE_END
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 SMP && ( MAXSMP || CPUMASK_OFFSTACK)
997 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
998 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800999
Ingo Molnaraec64872018-02-10 12:36:29 +01001000config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001001 int
1002 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +01001003 default 32 if X86_BIGSMP
1004 default 8 if SMP
1005 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001006
Ingo Molnaraec64872018-02-10 12:36:29 +01001007config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001008 int
1009 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001010 default 8192 if MAXSMP
1011 default 64 if SMP
1012 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001013
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001014config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -08001015 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +01001016 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1017 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001018 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001019 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001020 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001021 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001022 minimum value which makes sense is 2.
1023
Ingo Molnaraec64872018-02-10 12:36:29 +01001024 This is purely to save memory: each supported CPU adds about 8KB
1025 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001026
1027config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001028 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001029
1030config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001031 def_bool y
1032 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001033 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001034 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001035 Multi-core scheduler support improves the CPU scheduler's decision
1036 making when dealing with multi-core CPU chips at a cost of slightly
1037 increased overhead in some places. If unsure say N here.
1038
Tim Chende966cf2016-11-29 10:43:27 -08001039config SCHED_MC_PRIO
1040 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001041 depends on SCHED_MC && CPU_SUP_INTEL
1042 select X86_INTEL_PSTATE
1043 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001044 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001045 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001046 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1047 core ordering determined at manufacturing time, which allows
1048 certain cores to reach higher turbo frequencies (when running
1049 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001050
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001051 Enabling this kernel feature teaches the scheduler about
1052 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1053 scheduler's CPU selection logic accordingly, so that higher
1054 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001055
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001056 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001057
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001058 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001059
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001060config UP_LATE_INIT
1061 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +01001062 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001063
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001064config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001065 bool "Local APIC support on uniprocessors" if !PCI_MSI
1066 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001067 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001068 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001069 A local APIC (Advanced Programmable Interrupt Controller) is an
1070 integrated interrupt controller in the CPU. If you have a single-CPU
1071 system which has a processor with a local APIC, you can say Y here to
1072 enable and use it. If you say Y here even though your machine doesn't
1073 have a local APIC, then the kernel will still run with no slowdown at
1074 all. The local APIC supports CPU-generated self-interrupts (timer,
1075 performance counters), and the NMI watchdog which detects hard
1076 lockups.
1077
1078config X86_UP_IOAPIC
1079 bool "IO-APIC support on uniprocessors"
1080 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001081 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001082 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1083 SMP-capable replacement for PC-style interrupt controllers. Most
1084 SMP systems and many recent uniprocessor systems have one.
1085
1086 If you have a single-CPU system with an IO-APIC, you can say Y here
1087 to use it. If you say Y here even though your machine doesn't have
1088 an IO-APIC, then the kernel will still run with no slowdown at all.
1089
1090config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001091 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001092 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001093 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001094 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001095
1096config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001097 def_bool y
1098 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001099
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001100config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1101 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001102 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001103 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001104 This option enables a workaround that fixes a source of
1105 spurious interrupts. This is recommended when threaded
1106 interrupt handling is used on systems where the generation of
1107 superfluous "boot interrupts" cannot be disabled.
1108
1109 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1110 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1111 kernel does during interrupt handling). On chipsets where this
1112 boot IRQ generation cannot be disabled, this workaround keeps
1113 the original IRQ line masked so that only the equivalent "boot
1114 IRQ" is delivered to the CPUs. The workaround also tells the
1115 kernel to set up the IRQ handler on the boot IRQ line. In this
1116 way only one interrupt is delivered to the kernel. Otherwise
1117 the spurious second interrupt may cause the kernel to bring
1118 down (vital) interrupt lines.
1119
1120 Only affects "broken" chipsets. Interrupt sharing may be
1121 increased on these systems.
1122
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001123config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001124 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001125 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001126 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001127 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001128 Machine Check support allows the processor to notify the
1129 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001130 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001131 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001132
Tony Luck5de97c92017-03-27 11:33:03 +02001133config X86_MCELOG_LEGACY
1134 bool "Support for deprecated /dev/mcelog character device"
1135 depends on X86_MCE
1136 ---help---
1137 Enable support for /dev/mcelog which is needed by the old mcelog
1138 userspace logging daemon. Consider switching to the new generation
1139 rasdaemon solution.
1140
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001141config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001142 def_bool y
1143 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001144 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001145 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001146 Additional support for intel specific MCE features such as
1147 the thermal monitor.
1148
1149config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001150 def_bool y
1151 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001152 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001153 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001154 Additional support for AMD specific MCE features such as
1155 the DRAM Error Threshold.
1156
Andi Kleen4efc0672009-04-28 19:07:31 +02001157config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001158 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001159 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001160 ---help---
1161 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001162 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001163 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001164
Andi Kleenb2762682009-02-12 13:49:31 +01001165config X86_MCE_THRESHOLD
1166 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001167 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001168
Andi Kleenea149b32009-04-29 19:31:00 +02001169config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001170 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001171 tristate "Machine check injector support"
1172 ---help---
1173 Provide support for injecting machine checks for testing purposes.
1174 If you don't know what a machine check is and you don't do kernel
1175 QA it is safe to say n.
1176
Andi Kleen4efc0672009-04-28 19:07:31 +02001177config X86_THERMAL_VECTOR
1178 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001179 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001180
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001181source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001182
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001183config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001184 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001185 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001186 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001187 This option allows user programs to put the CPU into V8086
1188 mode, which is an 80286-era approximation of 16-bit real mode.
1189
1190 Some very old versions of X and/or vbetool require this option
1191 for user mode setting. Similarly, DOSEMU will use it if
1192 available to accelerate real mode DOS programs. However, any
1193 recent version of DOSEMU, X, or vbetool should be fully
1194 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001195 fall back to software emulation. Nevertheless, if you are using
1196 a 16-bit DOS program where 16-bit performance matters, vm86
1197 mode might be faster than emulation and you might want to
1198 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001199
Ingo Molnar1e642812015-09-05 08:58:10 +02001200 Note that any app that works on a 64-bit kernel is unlikely to
1201 need this option, as 64-bit kernels don't, and can't, support
1202 V8086 mode. This option is also unrelated to 16-bit protected
1203 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001204
Ingo Molnar1e642812015-09-05 08:58:10 +02001205 Enabling this option increases the complexity of the kernel
1206 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001207
Ingo Molnar1e642812015-09-05 08:58:10 +02001208 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001209
1210config VM86
1211 bool
1212 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001213
1214config X86_16BIT
1215 bool "Enable support for 16-bit segments" if EXPERT
1216 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001217 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001218 ---help---
1219 This option is required by programs like Wine to run 16-bit
1220 protected mode legacy code on x86 processors. Disabling
1221 this option saves about 300 bytes on i386, or around 6K text
1222 plus 16K runtime memory on x86-64,
1223
1224config X86_ESPFIX32
1225 def_bool y
1226 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001227
H. Peter Anvin197725d2014-05-04 10:00:49 -07001228config X86_ESPFIX64
1229 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001230 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001231
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001232config X86_VSYSCALL_EMULATION
1233 bool "Enable vsyscall emulation" if EXPERT
1234 default y
1235 depends on X86_64
1236 ---help---
1237 This enables emulation of the legacy vsyscall page. Disabling
1238 it is roughly equivalent to booting with vsyscall=none, except
1239 that it will also disable the helpful warning if a program
1240 tries to use a vsyscall. With this option set to N, offending
1241 programs will just segfault, citing addresses of the form
1242 0xffffffffff600?00.
1243
1244 This option is required by many programs built before 2013, and
1245 care should be used even with newer programs if set to N.
1246
1247 Disabling this option saves about 7K of kernel size and
1248 possibly 4K of additional runtime pagetable memory.
1249
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001250config TOSHIBA
1251 tristate "Toshiba Laptop support"
1252 depends on X86_32
1253 ---help---
1254 This adds a driver to safely access the System Management Mode of
1255 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256 not work on models with a Phoenix BIOS. The System Management Mode
1257 is used to set the BIOS and power saving options on Toshiba portables.
1258
1259 For information on utilities to make use of this driver see the
1260 Toshiba Linux utilities web site at:
1261 <http://www.buzzard.org.uk/toshiba/>.
1262
1263 Say Y if you intend to run this kernel on a Toshiba portable.
1264 Say N otherwise.
1265
1266config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001267 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001268 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001269 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001270 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001271 This option enables legacy /proc/i8k userspace interface in hwmon
1272 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273 temperature and allows controlling fan speeds of Dell laptops via
1274 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275 it reports also power and hotkey status. For fan speed control is
1276 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001277
Pali Rohár039ae582015-05-14 13:16:37 +02001278 Say Y if you intend to run this kernel on old Dell laptops or want to
1279 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001280 Say N otherwise.
1281
1282config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001283 bool "Enable X86 board specific fixups for reboot"
1284 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001285 ---help---
1286 This enables chipset and/or board specific fixups to be done
1287 in order to get reboot to work correctly. This is only needed on
1288 some combinations of hardware and BIOS. The symptom, for which
1289 this config is intended, is when reboot ends with a stalled/hung
1290 system.
1291
1292 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001293 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001294
1295 Say Y if you want to enable the fixup. Currently, it's safe to
1296 enable this option even if you don't need it.
1297 Say N otherwise.
1298
1299config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001300 bool "CPU microcode loading support"
1301 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001302 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001303 select FW_LOADER
1304 ---help---
1305 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001306 Intel and AMD processors. The Intel support is for the IA32 family,
1307 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1308 AMD support is for families 0x10 and later. You will obviously need
1309 the actual microcode binary data itself which is not shipped with
1310 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001312 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001313 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001314 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1315 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001316
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001317 In addition, you can build the microcode into the kernel. For that you
1318 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1319 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001320
Peter Oruba8d86f392008-07-28 18:44:21 +02001321config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001322 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001323 depends on MICROCODE
1324 default MICROCODE
1325 select FW_LOADER
1326 ---help---
1327 This options enables microcode patch loading support for Intel
1328 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001329
Alanb8989db2014-01-20 18:01:56 +00001330 For the current Intel microcode data package go to
1331 <https://downloadcenter.intel.com> and search for
1332 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001333
Peter Oruba80cc9f12008-07-28 18:44:22 +02001334config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001335 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001336 depends on MICROCODE
1337 select FW_LOADER
1338 ---help---
1339 If you select this option, microcode patch loading support for AMD
1340 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001341
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001342config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001343 bool "Ancient loading interface (DEPRECATED)"
1344 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001345 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001346 ---help---
1347 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1348 which was used by userspace tools like iucode_tool and microcode.ctl.
1349 It is inadequate because it runs too late to be able to properly
1350 load microcode on a machine and it needs special tools. Instead, you
1351 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001352 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001353
1354config X86_MSR
1355 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001356 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001357 This device gives privileged processes access to the x86
1358 Model-Specific Registers (MSRs). It is a character device with
1359 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360 MSR accesses are directed to a specific CPU on multi-processor
1361 systems.
1362
1363config X86_CPUID
1364 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001365 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001366 This device gives processes access to the x86 CPUID instruction to
1367 be executed on a specific processor. It is a character device
1368 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369 /dev/cpu/31/cpuid.
1370
1371choice
1372 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001373 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001374 depends on X86_32
1375
1376config NOHIGHMEM
1377 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001378 ---help---
1379 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380 However, the address space of 32-bit x86 processors is only 4
1381 Gigabytes large. That means that, if you have a large amount of
1382 physical memory, not all of it can be "permanently mapped" by the
1383 kernel. The physical memory that's not permanently mapped is called
1384 "high memory".
1385
1386 If you are compiling a kernel which will never run on a machine with
1387 more than 1 Gigabyte total physical RAM, answer "off" here (default
1388 choice and suitable for most users). This will result in a "3GB/1GB"
1389 split: 3GB are mapped so that each process sees a 3GB virtual memory
1390 space and the remaining part of the 4GB virtual memory space is used
1391 by the kernel to permanently map as much physical memory as
1392 possible.
1393
1394 If the machine has between 1 and 4 Gigabytes physical RAM, then
1395 answer "4GB" here.
1396
1397 If more than 4 Gigabytes is used then answer "64GB" here. This
1398 selection turns Intel PAE (Physical Address Extension) mode on.
1399 PAE implements 3-level paging on IA32 processors. PAE is fully
1400 supported by Linux, PAE mode is implemented on all recent Intel
1401 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402 then the kernel will not boot on CPUs that don't support PAE!
1403
1404 The actual amount of total physical memory will either be
1405 auto detected or can be forced by using a kernel command line option
1406 such as "mem=256M". (Try "man bootparam" or see the documentation of
1407 your boot loader (lilo or loadlin) about how to pass options to the
1408 kernel at boot time.)
1409
1410 If unsure, say "off".
1411
1412config HIGHMEM4G
1413 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001414 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001415 Select this if you have a 32-bit processor and between 1 and 4
1416 gigabytes of physical RAM.
1417
1418config HIGHMEM64G
1419 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001420 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001421 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001422 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001423 Select this if you have a 32-bit processor and more than 4
1424 gigabytes of physical RAM.
1425
1426endchoice
1427
1428choice
David Rientjes6a108a12011-01-20 14:44:16 -08001429 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001430 default VMSPLIT_3G
1431 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001432 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001433 Select the desired split between kernel and user memory.
1434
1435 If the address range available to the kernel is less than the
1436 physical memory installed, the remaining memory will be available
1437 as "high memory". Accessing high memory is a little more costly
1438 than low memory, as it needs to be mapped into the kernel first.
1439 Note that increasing the kernel address space limits the range
1440 available to user programs, making the address space there
1441 tighter. Selecting anything other than the default 3G/1G split
1442 will also likely make your kernel incompatible with binary-only
1443 kernel modules.
1444
1445 If you are not absolutely sure what you are doing, leave this
1446 option alone!
1447
1448 config VMSPLIT_3G
1449 bool "3G/1G user/kernel split"
1450 config VMSPLIT_3G_OPT
1451 depends on !X86_PAE
1452 bool "3G/1G user/kernel split (for full 1G low memory)"
1453 config VMSPLIT_2G
1454 bool "2G/2G user/kernel split"
1455 config VMSPLIT_2G_OPT
1456 depends on !X86_PAE
1457 bool "2G/2G user/kernel split (for full 2G low memory)"
1458 config VMSPLIT_1G
1459 bool "1G/3G user/kernel split"
1460endchoice
1461
1462config PAGE_OFFSET
1463 hex
1464 default 0xB0000000 if VMSPLIT_3G_OPT
1465 default 0x80000000 if VMSPLIT_2G
1466 default 0x78000000 if VMSPLIT_2G_OPT
1467 default 0x40000000 if VMSPLIT_1G
1468 default 0xC0000000
1469 depends on X86_32
1470
1471config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001472 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001473 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001474
1475config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001476 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001477 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001478 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001479 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001480 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001481 PAE is required for NX support, and furthermore enables
1482 larger swapspace support for non-overcommit purposes. It
1483 has the cost of more pagetable lookup overhead, and also
1484 consumes more pagetable space per process.
1485
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001486config X86_5LEVEL
1487 bool "Enable 5-level page tables support"
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001488 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001489 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001490 depends on X86_64
1491 ---help---
1492 5-level paging enables access to larger address space:
1493 upto 128 PiB of virtual address space and 4 PiB of
1494 physical address space.
1495
1496 It will be supported by future Intel CPUs.
1497
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001498 A kernel with the option enabled can be booted on machines that
1499 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001500
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001501 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001502 information.
1503
1504 Say N if unsure.
1505
Ingo Molnar10971ab2015-03-05 08:18:23 +01001506config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001507 def_bool y
Levin, Alexander (Sasha Levin)4675ff02017-11-15 17:36:02 -08001508 depends on X86_64 && !DEBUG_PAGEALLOC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001509 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001510 Certain kernel features effectively disable kernel
1511 linear 1 GB mappings (even if the CPU otherwise
1512 supports them), so don't confuse the user by printing
1513 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001514
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001515config X86_CPA_STATISTICS
1516 bool "Enable statistic for Change Page Attribute"
1517 depends on DEBUG_FS
1518 ---help---
1519 Expose statistics about the Change Page Attribute mechanims, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001520 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001521 page mappings when mapping protections are changed.
1522
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001523config ARCH_HAS_MEM_ENCRYPT
1524 def_bool y
1525
1526config AMD_MEM_ENCRYPT
1527 bool "AMD Secure Memory Encryption (SME) support"
1528 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001529 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001530 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001531 ---help---
1532 Say yes to enable support for the encryption of system memory.
1533 This requires an AMD processor that supports Secure Memory
1534 Encryption (SME).
1535
1536config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1537 bool "Activate AMD Secure Memory Encryption (SME) by default"
1538 default y
1539 depends on AMD_MEM_ENCRYPT
1540 ---help---
1541 Say yes to have system memory encrypted by default if running on
1542 an AMD processor that supports Secure Memory Encryption (SME).
1543
1544 If set to Y, then the encryption of system memory can be
1545 deactivated with the mem_encrypt=off command line option.
1546
1547 If set to N, then the encryption of system memory can be
1548 activated with the mem_encrypt=on command line option.
1549
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001550# Common NUMA Features
1551config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001552 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001553 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001554 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1555 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001556 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001557 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001558
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001559 The kernel will try to allocate memory used by a CPU on the
1560 local memory controller of the CPU and add some more
1561 NUMA awareness to the kernel.
1562
Ingo Molnarc280ea52008-11-08 13:29:45 +01001563 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001564 (or later), AMD Opteron, or EM64T NUMA.
1565
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001566 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001567 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001568
1569 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001570
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001571config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001572 def_bool y
1573 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001574 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001575 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001576 Enable AMD NUMA node topology detection. You should say Y here if
1577 you have a multi processor AMD system. This uses an old method to
1578 read the NUMA configuration directly from the builtin Northbridge
1579 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1580 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001581
1582config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001583 def_bool y
1584 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001585 depends on X86_64 && NUMA && ACPI && PCI
1586 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001587 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001588 Enable ACPI SRAT based node topology detection.
1589
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001590# Some NUMA nodes have memory ranges that span
1591# other nodes. Even though a pfn is valid and
1592# between a node's start and end pfns, it may not
1593# reside on that node. See memmap_init_zone()
1594# for details.
1595config NODES_SPAN_OTHER_NODES
1596 def_bool y
1597 depends on X86_64_ACPI_NUMA
1598
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001599config NUMA_EMU
1600 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001601 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001602 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001603 Enable NUMA emulation. A flat machine will be split
1604 into virtual nodes when booted with "numa=fake=N", where N is the
1605 number of nodes. This is only useful for debugging.
1606
1607config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001608 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001609 range 1 10
1610 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001611 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001612 default "3"
1613 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001614 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001615 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001616 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001617
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001618config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001619 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001620 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001621
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001622config ARCH_FLATMEM_ENABLE
1623 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001624 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001625
1626config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001627 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001628 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001629 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001630
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001631config ARCH_SPARSEMEM_ENABLE
1632 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001633 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001634 select SPARSEMEM_STATIC if X86_32
1635 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1636
Tejun Heo3b166512011-04-01 11:15:12 +02001637config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001638 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001639
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001640config ARCH_SELECT_MEMORY_MODEL
1641 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001642 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001643
1644config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001645 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001646 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001647 help
1648 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001649 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001650 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001651
Tejun Heo3b166512011-04-01 11:15:12 +02001652config ARCH_PROC_KCORE_TEXT
1653 def_bool y
1654 depends on X86_64 && PROC_KCORE
1655
Avi Kivitya29815a2010-01-10 16:28:09 +02001656config ILLEGAL_POINTER_VALUE
1657 hex
1658 default 0 if X86_32
1659 default 0xdead000000000000 if X86_64
1660
Dan Williams7a678322015-08-19 00:34:34 -04001661config X86_PMEM_LEGACY_DEVICE
1662 bool
1663
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001664config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001665 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001666 depends on PHYS_ADDR_T_64BIT
1667 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001668 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001669 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001670 help
1671 Treat memory marked using the non-standard e820 type of 12 as used
1672 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1673 The kernel will offer these regions to the 'pmem' driver so
1674 they can be used for persistent storage.
1675
1676 Say Y if unsure.
1677
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001678config HIGHPTE
1679 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001680 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001681 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001682 The VM uses one page table entry for each page of physical memory.
1683 For systems with a lot of RAM, this can be wasteful of precious
1684 low memory. Setting this option will put user-space page table
1685 entries in high memory.
1686
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001687config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001688 bool "Check for low memory corruption"
1689 ---help---
1690 Periodically check for memory corruption in low memory, which
1691 is suspected to be caused by BIOS. Even when enabled in the
1692 configuration, it is disabled at runtime. Enable it by
1693 setting "memory_corruption_check=1" on the kernel command
1694 line. By default it scans the low 64k of memory every 60
1695 seconds; see the memory_corruption_check_size and
1696 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001697 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001698
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001699 When enabled with the default parameters, this option has
1700 almost no overhead, as it reserves a relatively small amount
1701 of memory and scans it infrequently. It both detects corruption
1702 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001703
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001704 It is, however, intended as a diagnostic tool; if repeatable
1705 BIOS-originated corruption always affects the same memory,
1706 you can use memmap= to prevent the kernel from using that
1707 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001708
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001709config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001710 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001711 depends on X86_CHECK_BIOS_CORRUPTION
1712 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001713 ---help---
1714 Set whether the default state of memory_corruption_check is
1715 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001716
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001717config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001718 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1719 default 64
1720 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001721 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001722 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001723
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001724 The first page contains BIOS data structures that the kernel
1725 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001726
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001727 By default we reserve the first 64K of physical RAM, as a
1728 number of BIOSes are known to corrupt that memory range
1729 during events such as suspend/resume or monitor cable
1730 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001731
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001732 You can set this to 4 if you are absolutely sure that you
1733 trust the BIOS to get all its memory reservations and usages
1734 right. If you know your BIOS have problems beyond the
1735 default 64K area, you can set this to 640 to avoid using the
1736 entire low memory range.
1737
1738 If you have doubts about the BIOS (e.g. suspend/resume does
1739 not work or there's kernel crashes after certain hardware
1740 hotplug events) then you might want to enable
1741 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1742 typical corruption patterns.
1743
1744 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001745
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001746config MATH_EMULATION
1747 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001748 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001749 prompt "Math emulation" if X86_32
1750 ---help---
1751 Linux can emulate a math coprocessor (used for floating point
1752 operations) if you don't have one. 486DX and Pentium processors have
1753 a math coprocessor built in, 486SX and 386 do not, unless you added
1754 a 487DX or 387, respectively. (The messages during boot time can
1755 give you some hints here ["man dmesg"].) Everyone needs either a
1756 coprocessor or this emulation.
1757
1758 If you don't have a math coprocessor, you need to say Y here; if you
1759 say Y here even though you have a coprocessor, the coprocessor will
1760 be used nevertheless. (This behavior can be changed with the kernel
1761 command line option "no387", which comes handy if your coprocessor
1762 is broken. Try "man bootparam" or see the documentation of your boot
1763 loader (lilo or loadlin) about how to pass options to the kernel at
1764 boot time.) This means that it is a good idea to say Y here if you
1765 intend to use this kernel on different machines.
1766
1767 More information about the internals of the Linux math coprocessor
1768 emulation can be found in <file:arch/x86/math-emu/README>.
1769
1770 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1771 kernel, it won't hurt.
1772
1773config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001774 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001775 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001776 ---help---
1777 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1778 the Memory Type Range Registers (MTRRs) may be used to control
1779 processor access to memory ranges. This is most useful if you have
1780 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1781 allows bus write transfers to be combined into a larger transfer
1782 before bursting over the PCI/AGP bus. This can increase performance
1783 of image write operations 2.5 times or more. Saying Y here creates a
1784 /proc/mtrr file which may be used to manipulate your processor's
1785 MTRRs. Typically the X server should use this.
1786
1787 This code has a reasonably generic interface so that similar
1788 control registers on other processors can be easily supported
1789 as well:
1790
1791 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1792 Registers (ARRs) which provide a similar functionality to MTRRs. For
1793 these, the ARRs are used to emulate the MTRRs.
1794 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1795 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1796 write-combining. All of these processors are supported by this code
1797 and it makes sense to say Y here if you have one of them.
1798
1799 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1800 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1801 can lead to all sorts of problems, so it's good to say Y here.
1802
1803 You can safely say Y even if your machine doesn't have MTRRs, you'll
1804 just add about 9 KB to your kernel.
1805
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001806 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001807
Yinghai Lu95ffa242008-04-29 03:52:33 -07001808config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001809 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001810 prompt "MTRR cleanup support"
1811 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001812 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001813 Convert MTRR layout from continuous to discrete, so X drivers can
1814 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001815
Thomas Gleixneraba37282008-07-15 14:48:48 +02001816 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001817 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001818 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001819
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001820 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001821
1822config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001823 int "MTRR cleanup enable value (0-1)"
1824 range 0 1
1825 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001826 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001827 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001828 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001829
Yinghai Lu12031a62008-05-02 02:40:22 -07001830config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1831 int "MTRR cleanup spare reg num (0-7)"
1832 range 0 7
1833 default "1"
1834 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001835 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001836 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001837 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001838
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001839config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001840 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001841 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001842 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001843 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001844 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001845
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001846 PATs are the modern equivalents of MTRRs and are much more
1847 flexible than MTRRs.
1848
1849 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001850 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001851
1852 If unsure, say Y.
1853
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001854config ARCH_USES_PG_UNCACHED
1855 def_bool y
1856 depends on X86_PAT
1857
H. Peter Anvin628c6242011-07-31 13:59:29 -07001858config ARCH_RANDOM
1859 def_bool y
1860 prompt "x86 architectural random number generator" if EXPERT
1861 ---help---
1862 Enable the x86 architectural RDRAND instruction
1863 (Intel Bull Mountain technology) to generate random numbers.
1864 If supported, this is a high bandwidth, cryptographically
1865 secure hardware random number generator.
1866
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001867config X86_SMAP
1868 def_bool y
1869 prompt "Supervisor Mode Access Prevention" if EXPERT
1870 ---help---
1871 Supervisor Mode Access Prevention (SMAP) is a security
1872 feature in newer Intel processors. There is a small
1873 performance cost if this enabled and turned on; there is
1874 also a small increase in the kernel size if this is enabled.
1875
1876 If unsure, say Y.
1877
Ricardo Neriaa35f892017-11-05 18:27:54 -08001878config X86_INTEL_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001879 def_bool y
Ricardo Neriaa35f892017-11-05 18:27:54 -08001880 depends on CPU_SUP_INTEL
1881 prompt "Intel User Mode Instruction Prevention" if EXPERT
1882 ---help---
1883 The User Mode Instruction Prevention (UMIP) is a security
1884 feature in newer Intel processors. If enabled, a general
Ricardo Neri796ebc82017-11-13 22:29:42 -08001885 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1886 or STR instructions are executed in user mode. These instructions
1887 unnecessarily expose information about the hardware state.
1888
1889 The vast majority of applications do not use these instructions.
1890 For the very few that do, software emulation is provided in
1891 specific cases in protected and virtual-8086 modes. Emulated
1892 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001893
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001894config X86_INTEL_MPX
1895 prompt "Intel MPX (Memory Protection Extensions)"
1896 def_bool n
Rik van Rieldf3735c2017-09-06 16:25:11 -07001897 # Note: only available in 64-bit mode due to VMA flags shortage
1898 depends on CPU_SUP_INTEL && X86_64
1899 select ARCH_USES_HIGH_VMA_FLAGS
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001900 ---help---
1901 MPX provides hardware features that can be used in
1902 conjunction with compiler-instrumented code to check
1903 memory references. It is designed to detect buffer
1904 overflow or underflow bugs.
1905
1906 This option enables running applications which are
1907 instrumented or otherwise use MPX. It does not use MPX
1908 itself inside the kernel or to protect the kernel
1909 against bad memory references.
1910
1911 Enabling this option will make the kernel larger:
1912 ~8k of kernel text and 36 bytes of data on a 64-bit
1913 defconfig. It adds a long to the 'mm_struct' which
1914 will increase the kernel memory overhead of each
1915 process and adds some branches to paths used during
1916 exec() and munmap().
1917
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001918 For details, see Documentation/x86/intel_mpx.rst
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001919
1920 If unsure, say N.
1921
Dave Hansen35e97792016-02-12 13:02:00 -08001922config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001923 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001924 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001925 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001926 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001927 select ARCH_USES_HIGH_VMA_FLAGS
1928 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001929 ---help---
1930 Memory Protection Keys provides a mechanism for enforcing
1931 page-based protections, but without requiring modification of the
1932 page tables when an application changes protection domains.
1933
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001934 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001935
1936 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001937
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001938config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001939 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001940 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001941 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001942 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001943 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001944 This enables the kernel to use EFI runtime services that are
1945 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001946
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001947 This option is only useful on systems that have EFI firmware.
1948 In addition, you should use the latest ELILO loader available
1949 at <http://elilo.sourceforge.net> in order to take advantage
1950 of EFI runtime services. However, even with this option, the
1951 resultant kernel should continue to boot on existing non-EFI
1952 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001953
Matt Fleming291f3632011-12-12 21:27:52 +00001954config EFI_STUB
1955 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001956 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001957 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001958 ---help---
1959 This kernel feature allows a bzImage to be loaded directly
1960 by EFI firmware without the use of a bootloader.
1961
Roy Franz4172fe22013-09-22 15:45:25 -07001962 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001963
Matt Fleming7d453ee2014-01-10 18:52:06 +00001964config EFI_MIXED
1965 bool "EFI mixed-mode support"
1966 depends on EFI_STUB && X86_64
1967 ---help---
1968 Enabling this feature allows a 64-bit kernel to be booted
1969 on a 32-bit firmware, provided that your CPU supports 64-bit
1970 mode.
1971
1972 Note that it is not possible to boot a mixed-mode enabled
1973 kernel via the EFI boot stub - a bootloader that supports
1974 the EFI handover protocol must be used.
1975
1976 If unsure, say N.
1977
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001978config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001979 def_bool y
1980 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001981 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001982 This kernel feature is useful for number crunching applications
1983 that may need to compute untrusted bytecode during their
1984 execution. By using pipes or other transports made available to
1985 the process as file descriptors supporting the read/write
1986 syscalls, it's possible to isolate those applications in
1987 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001988 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001989 and the task is only allowed to execute a few safe syscalls
1990 defined by each seccomp mode.
1991
1992 If unsure, say Y. Only embedded should say N here.
1993
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09001994source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001995
1996config KEXEC
1997 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001998 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001999 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002000 kexec is a system call that implements the ability to shutdown your
2001 current kernel, and to start another kernel. It is like a reboot
2002 but it is independent of the system firmware. And like a reboot
2003 you can start any kernel with it, not just Linux.
2004
2005 The name comes from the similarity to the exec system call.
2006
2007 It is an ongoing process to be certain the hardware in a machine
2008 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002009 initially work for you. As of this writing the exact hardware
2010 interface is strongly in flux, so no good recommendation can be
2011 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002012
Vivek Goyal74ca3172014-08-29 15:18:46 -07002013config KEXEC_FILE
2014 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002015 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002016 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002017 depends on X86_64
2018 depends on CRYPTO=y
2019 depends on CRYPTO_SHA256=y
2020 ---help---
2021 This is new version of kexec system call. This system call is
2022 file based and takes file descriptors as system call argument
2023 for kernel and initramfs as opposed to list of segments as
2024 accepted by previous system call.
2025
AKASHI Takahirob799a092018-04-13 15:35:45 -07002026config ARCH_HAS_KEXEC_PURGATORY
2027 def_bool KEXEC_FILE
2028
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002029config KEXEC_VERIFY_SIG
2030 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002031 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002032 ---help---
2033 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002034 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002035
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002036 In addition to that option, you need to enable signature
2037 verification for the corresponding kernel image type being
2038 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002039
2040config KEXEC_BZIMAGE_VERIFY_SIG
2041 bool "Enable bzImage signature verification support"
2042 depends on KEXEC_VERIFY_SIG
2043 depends on SIGNED_PE_FILE_VERIFICATION
2044 select SYSTEM_TRUSTED_KEYRING
2045 ---help---
2046 Enable bzImage signature verification support.
2047
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002048config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002049 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002050 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002051 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002052 Generate crash dump after being started by kexec.
2053 This should be normally only set in special crash dump kernels
2054 which are loaded in the main kernel with kexec-tools into
2055 a specially reserved region and then later executed after
2056 a crash by kdump/kexec. The crash dump kernel must be compiled
2057 to a memory address not used by the main kernel or BIOS using
2058 PHYSICAL_START, or it must be built as a relocatable image
2059 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehabd67297a2019-06-12 14:52:49 -03002060 For more details see Documentation/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002061
Huang Ying3ab83522008-07-25 19:45:07 -07002062config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002063 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002064 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002065 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002066 Jump between original kernel and kexeced kernel and invoke
2067 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002068
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002069config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002070 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002071 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002072 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002073 This gives the physical address where the kernel is loaded.
2074
2075 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2076 bzImage will decompress itself to above physical address and
2077 run from there. Otherwise, bzImage will run from the address where
2078 it has been loaded by the boot loader and will ignore above physical
2079 address.
2080
2081 In normal kdump cases one does not have to set/change this option
2082 as now bzImage can be compiled as a completely relocatable image
2083 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2084 address. This option is mainly useful for the folks who don't want
2085 to use a bzImage for capturing the crash dump and want to use a
2086 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2087 to be specifically compiled to run from a specific memory area
2088 (normally a reserved region) and this option comes handy.
2089
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002090 So if you are using bzImage for capturing the crash dump,
2091 leave the value here unchanged to 0x1000000 and set
2092 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2093 for capturing the crash dump change this value to start of
2094 the reserved region. In other words, it can be set based on
2095 the "X" value as specified in the "crashkernel=YM@XM"
2096 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehabd67297a2019-06-12 14:52:49 -03002097 kernel. Please take a look at Documentation/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002098 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002099
2100 Usage of bzImage for capturing the crash dump is recommended as
2101 one does not have to build two kernels. Same kernel can be used
2102 as production kernel and capture kernel. Above option should have
2103 gone away after relocatable bzImage support is introduced. But it
2104 is present because there are users out there who continue to use
2105 vmlinux for dump capture. This option should go away down the
2106 line.
2107
2108 Don't change this unless you know what you are doing.
2109
2110config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002111 bool "Build a relocatable kernel"
2112 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002113 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002114 This builds a kernel image that retains relocation information
2115 so it can be loaded someplace besides the default 1MB.
2116 The relocations tend to make the kernel binary about 10% larger,
2117 but are discarded at runtime.
2118
2119 One use is for the kexec on panic case where the recovery kernel
2120 must live at a different physical address than the primary
2121 kernel.
2122
2123 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2124 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002125 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002126
Kees Cook8ab38202013-10-10 17:18:14 -07002127config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002128 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002129 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002130 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002131 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002132 In support of Kernel Address Space Layout Randomization (KASLR),
2133 this randomizes the physical address at which the kernel image
2134 is decompressed and the virtual address where the kernel
2135 image is mapped, as a security feature that deters exploit
2136 attempts relying on knowledge of the location of kernel
2137 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002138
Kees Cooked9f0072016-05-25 15:45:33 -07002139 On 64-bit, the kernel physical and virtual addresses are
2140 randomized separately. The physical address will be anywhere
2141 between 16MB and the top of physical memory (up to 64TB). The
2142 virtual address will be randomized from 16MB up to 1GB (9 bits
2143 of entropy). Note that this also reduces the memory space
2144 available to kernel modules from 1.5GB to 1GB.
2145
2146 On 32-bit, the kernel physical and virtual addresses are
2147 randomized together. They will be randomized from 16MB up to
2148 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002149
Baoquan Hee8581e32016-04-20 13:55:43 -07002150 Entropy is generated using the RDRAND instruction if it is
2151 supported. If RDTSC is supported, its value is mixed into
2152 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002153 supported, then entropy is read from the i8254 timer. The
2154 usable entropy is limited by the kernel being built using
2155 2GB addressing, and that PHYSICAL_ALIGN must be at a
2156 minimum of 2MB. As a result, only 10 bits of entropy are
2157 theoretically possible, but the implementations are further
2158 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002159
Ingo Molnar6807c842017-04-18 11:08:12 +02002160 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002161
2162# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002163config X86_NEED_RELOCS
2164 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002165 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002166
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002167config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002168 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002169 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002170 range 0x2000 0x1000000 if X86_32
2171 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002172 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002173 This value puts the alignment restrictions on physical address
2174 where kernel is loaded and run from. Kernel is compiled for an
2175 address which meets above alignment restriction.
2176
2177 If bootloader loads the kernel at a non-aligned address and
2178 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2179 address aligned to above value and run from there.
2180
2181 If bootloader loads the kernel at a non-aligned address and
2182 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2183 load address and decompress itself to the address it has been
2184 compiled for and run from there. The address for which kernel is
2185 compiled already meets above alignment restrictions. Hence the
2186 end result is that kernel runs from a physical address meeting
2187 above alignment restrictions.
2188
Kees Cooka0215062013-07-08 09:15:17 -07002189 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2190 this value must be a multiple of 0x200000.
2191
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002192 Don't change this unless you know what you are doing.
2193
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002194config DYNAMIC_MEMORY_LAYOUT
2195 bool
2196 ---help---
2197 This option makes base addresses of vmalloc and vmemmap as well as
2198 __PAGE_OFFSET movable during boot.
2199
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002200config RANDOMIZE_MEMORY
2201 bool "Randomize the kernel memory sections"
2202 depends on X86_64
2203 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002204 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002205 default RANDOMIZE_BASE
2206 ---help---
2207 Randomizes the base virtual address of kernel memory sections
2208 (physical memory mapping, vmalloc & vmemmap). This security feature
2209 makes exploits relying on predictable memory locations less reliable.
2210
2211 The order of allocations remains unchanged. Entropy is generated in
2212 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2213 configuration have in average 30,000 different possible virtual
2214 addresses for each memory section.
2215
Ingo Molnar6807c842017-04-18 11:08:12 +02002216 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002217
Thomas Garnier90397a42016-06-21 17:47:06 -07002218config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2219 hex "Physical memory mapping padding" if EXPERT
2220 depends on RANDOMIZE_MEMORY
2221 default "0xa" if MEMORY_HOTPLUG
2222 default "0x0"
2223 range 0x1 0x40 if MEMORY_HOTPLUG
2224 range 0x0 0x40
2225 ---help---
2226 Define the padding in terabytes added to the existing physical
2227 memory size during kernel memory randomization. It is useful
2228 for memory hotplug support but reduces the entropy available for
2229 address randomization.
2230
2231 If unsure, leave at the default value.
2232
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002233config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002234 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002235 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002236
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002237config BOOTPARAM_HOTPLUG_CPU0
2238 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002239 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002240 ---help---
2241 Set whether default state of cpu0_hotpluggable is on or off.
2242
2243 Say Y here to enable CPU0 hotplug by default. If this switch
2244 is turned on, there is no need to give cpu0_hotplug kernel
2245 parameter and the CPU0 hotplug feature is enabled by default.
2246
2247 Please note: there are two known CPU0 dependencies if you want
2248 to enable the CPU0 hotplug feature either by this switch or by
2249 cpu0_hotplug kernel parameter.
2250
2251 First, resume from hibernate or suspend always starts from CPU0.
2252 So hibernate and suspend are prevented if CPU0 is offline.
2253
2254 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2255 offline if any interrupt can not migrate out of CPU0. There may
2256 be other CPU0 dependencies.
2257
2258 Please make sure the dependencies are under your control before
2259 you enable this feature.
2260
2261 Say N if you don't want to enable CPU0 hotplug feature by default.
2262 You still can enable the CPU0 hotplug feature at boot by kernel
2263 parameter cpu0_hotplug.
2264
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002265config DEBUG_HOTPLUG_CPU0
2266 def_bool n
2267 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002268 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002269 ---help---
2270 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2271 soon as possible and boots up userspace with CPU0 offlined. User
2272 can online CPU0 back after boot time.
2273
2274 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2275 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2276 compilation or giving cpu0_hotplug kernel parameter at boot.
2277
2278 If unsure, say N.
2279
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002280config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002281 def_bool n
2282 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002283 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002284 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002285 Certain buggy versions of glibc will crash if they are
2286 presented with a 32-bit vDSO that is not mapped at the address
2287 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002288
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002289 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2290 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2291 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2292 the only released version with the bug, but OpenSUSE 9
2293 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002294
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002295 The symptom of the bug is that everything crashes on startup, saying:
2296 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2297
2298 Saying Y here changes the default value of the vdso32 boot
2299 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2300 This works around the glibc bug but hurts performance.
2301
2302 If unsure, say N: if you are compiling your own kernel, you
2303 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002304
Kees Cook3dc33bd2015-08-12 17:55:19 -07002305choice
2306 prompt "vsyscall table for legacy applications"
2307 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002308 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002309 help
2310 Legacy user code that does not know how to find the vDSO expects
2311 to be able to issue three syscalls by calling fixed addresses in
2312 kernel space. Since this location is not randomized with ASLR,
2313 it can be used to assist security vulnerability exploitation.
2314
2315 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002316 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002317
2318 On a system with recent enough glibc (2.14 or newer) and no
2319 static binaries, you can say None without a performance penalty
2320 to improve security.
2321
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002322 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002323
Kees Cook3dc33bd2015-08-12 17:55:19 -07002324 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002325 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002326 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002327 The kernel traps and emulates calls into the fixed vsyscall
2328 address mapping. This makes the mapping non-executable, but
2329 it still contains readable known contents, which could be
2330 used in certain rare security vulnerability exploits. This
2331 configuration is recommended when using legacy userspace
2332 that still uses vsyscalls along with legacy binary
2333 instrumentation tools that require code to be readable.
2334
2335 An example of this type of legacy userspace is running
2336 Pin on an old binary that still uses vsyscalls.
2337
2338 config LEGACY_VSYSCALL_XONLY
2339 bool "Emulate execution only"
2340 help
2341 The kernel traps and emulates calls into the fixed vsyscall
2342 address mapping and does not allow reads. This
2343 configuration is recommended when userspace might use the
2344 legacy vsyscall area but support for legacy binary
2345 instrumentation of legacy code is not needed. It mitigates
2346 certain uses of the vsyscall area as an ASLR-bypassing
2347 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002348
2349 config LEGACY_VSYSCALL_NONE
2350 bool "None"
2351 help
2352 There will be no vsyscall mapping at all. This will
2353 eliminate any risk of ASLR bypass due to the vsyscall
2354 fixed address mapping. Attempts to use the vsyscalls
2355 will be reported to dmesg, so that either old or
2356 malicious userspace programs can be identified.
2357
2358endchoice
2359
Tim Bird516cbf32008-08-12 12:52:36 -07002360config CMDLINE_BOOL
2361 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002362 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002363 Allow for specifying boot arguments to the kernel at
2364 build time. On some systems (e.g. embedded ones), it is
2365 necessary or convenient to provide some or all of the
2366 kernel boot arguments with the kernel itself (that is,
2367 to not rely on the boot loader to provide them.)
2368
2369 To compile command line arguments into the kernel,
2370 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002371 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002372
2373 Systems with fully functional boot loaders (i.e. non-embedded)
2374 should leave this option set to 'N'.
2375
2376config CMDLINE
2377 string "Built-in kernel command string"
2378 depends on CMDLINE_BOOL
2379 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002380 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002381 Enter arguments here that should be compiled into the kernel
2382 image and used at boot time. If the boot loader provides a
2383 command line at boot time, it is appended to this string to
2384 form the full kernel command line, when the system boots.
2385
2386 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2387 change this behavior.
2388
2389 In most cases, the command line (whether built-in or provided
2390 by the boot loader) should specify the device for the root
2391 file system.
2392
2393config CMDLINE_OVERRIDE
2394 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002395 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002396 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002397 Set this option to 'Y' to have the kernel ignore the boot loader
2398 command line, and use ONLY the built-in command line.
2399
2400 This is used to work around broken boot loaders. This should
2401 be set to 'N' under normal conditions.
2402
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002403config MODIFY_LDT_SYSCALL
2404 bool "Enable the LDT (local descriptor table)" if EXPERT
2405 default y
2406 ---help---
2407 Linux can allow user programs to install a per-process x86
2408 Local Descriptor Table (LDT) using the modify_ldt(2) system
2409 call. This is required to run 16-bit or segmented code such as
2410 DOSEMU or some Wine programs. It is also used by some very old
2411 threading libraries.
2412
2413 Enabling this feature adds a small amount of overhead to
2414 context switches and increases the low-level kernel attack
2415 surface. Disabling it removes the modify_ldt(2) system call.
2416
2417 Saying 'N' here may make sense for embedded or server kernels.
2418
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002419source "kernel/livepatch/Kconfig"
2420
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002421endmenu
2422
Michal Hocko3072e412017-09-08 16:11:39 -07002423config ARCH_HAS_ADD_PAGES
2424 def_bool y
2425 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2426
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002427config ARCH_ENABLE_MEMORY_HOTPLUG
2428 def_bool y
2429 depends on X86_64 || (X86_32 && HIGHMEM)
2430
Gary Hade35551052008-10-31 10:52:03 -07002431config ARCH_ENABLE_MEMORY_HOTREMOVE
2432 def_bool y
2433 depends on MEMORY_HOTPLUG
2434
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002435config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002436 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002437 depends on NUMA
2438
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002439config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2440 def_bool y
2441 depends on X86_64 || X86_PAE
2442
Naoya Horiguchic177c812014-06-04 16:05:35 -07002443config ARCH_ENABLE_HUGEPAGE_MIGRATION
2444 def_bool y
2445 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2446
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002447config ARCH_ENABLE_THP_MIGRATION
2448 def_bool y
2449 depends on X86_64 && TRANSPARENT_HUGEPAGE
2450
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002451menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002452
2453config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002454 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002455 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002456
2457source "kernel/power/Kconfig"
2458
2459source "drivers/acpi/Kconfig"
2460
Feng Tangefafc8b2009-08-14 15:23:29 -04002461source "drivers/sfi/Kconfig"
2462
Andi Kleena6b68072008-01-30 13:32:49 +01002463config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002464 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002465 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002466
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002467menuconfig APM
2468 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002469 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002470 ---help---
2471 APM is a BIOS specification for saving power using several different
2472 techniques. This is mostly useful for battery powered laptops with
2473 APM compliant BIOSes. If you say Y here, the system time will be
2474 reset after a RESUME operation, the /proc/apm device will provide
2475 battery status information, and user-space programs will receive
2476 notification of APM "events" (e.g. battery status change).
2477
2478 If you select "Y" here, you can disable actual use of the APM
2479 BIOS by passing the "apm=off" option to the kernel at boot time.
2480
2481 Note that the APM support is almost completely disabled for
2482 machines with more than one CPU.
2483
2484 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002485 and more information, read <file:Documentation/power/apm-acpi.txt>
2486 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002487 <http://www.tldp.org/docs.html#howto>.
2488
2489 This driver does not spin down disk drives (see the hdparm(8)
2490 manpage ("man 8 hdparm") for that), and it doesn't turn off
2491 VESA-compliant "green" monitors.
2492
2493 This driver does not support the TI 4000M TravelMate and the ACER
2494 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2495 desktop machines also don't have compliant BIOSes, and this driver
2496 may cause those machines to panic during the boot phase.
2497
2498 Generally, if you don't have a battery in your machine, there isn't
2499 much point in using this driver and you should say N. If you get
2500 random kernel OOPSes or reboots that don't seem to be related to
2501 anything, try disabling/enabling this option (or disabling/enabling
2502 APM in your BIOS).
2503
2504 Some other things you should try when experiencing seemingly random,
2505 "weird" problems:
2506
2507 1) make sure that you have enough swap space and that it is
2508 enabled.
2509 2) pass the "no-hlt" option to the kernel
2510 3) switch on floating point emulation in the kernel and pass
2511 the "no387" option to the kernel
2512 4) pass the "floppy=nodma" option to the kernel
2513 5) pass the "mem=4M" option to the kernel (thereby disabling
2514 all but the first 4 MB of RAM)
2515 6) make sure that the CPU is not over clocked.
2516 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2517 8) disable the cache from your BIOS settings
2518 9) install a fan for the video card or exchange video RAM
2519 10) install a better fan for the CPU
2520 11) exchange RAM chips
2521 12) exchange the motherboard.
2522
2523 To compile this driver as a module, choose M here: the
2524 module will be called apm.
2525
2526if APM
2527
2528config APM_IGNORE_USER_SUSPEND
2529 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002530 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002531 This option will ignore USER SUSPEND requests. On machines with a
2532 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2533 series notebooks, it is necessary to say Y because of a BIOS bug.
2534
2535config APM_DO_ENABLE
2536 bool "Enable PM at boot time"
2537 ---help---
2538 Enable APM features at boot time. From page 36 of the APM BIOS
2539 specification: "When disabled, the APM BIOS does not automatically
2540 power manage devices, enter the Standby State, enter the Suspend
2541 State, or take power saving steps in response to CPU Idle calls."
2542 This driver will make CPU Idle calls when Linux is idle (unless this
2543 feature is turned off -- see "Do CPU IDLE calls", below). This
2544 should always save battery power, but more complicated APM features
2545 will be dependent on your BIOS implementation. You may need to turn
2546 this option off if your computer hangs at boot time when using APM
2547 support, or if it beeps continuously instead of suspending. Turn
2548 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2549 T400CDT. This is off by default since most machines do fine without
2550 this feature.
2551
2552config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002553 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002554 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002555 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002556 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2557 On some machines, this can activate improved power savings, such as
2558 a slowed CPU clock rate, when the machine is idle. These idle calls
2559 are made after the idle loop has run for some length of time (e.g.,
2560 333 mS). On some machines, this will cause a hang at boot time or
2561 whenever the CPU becomes idle. (On machines with more than one CPU,
2562 this option does nothing.)
2563
2564config APM_DISPLAY_BLANK
2565 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002566 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002567 Enable console blanking using the APM. Some laptops can use this to
2568 turn off the LCD backlight when the screen blanker of the Linux
2569 virtual console blanks the screen. Note that this is only used by
2570 the virtual console screen blanker, and won't turn off the backlight
2571 when using the X Window system. This also doesn't have anything to
2572 do with your VESA-compliant power-saving monitor. Further, this
2573 option doesn't work for all laptops -- it might not turn off your
2574 backlight at all, or it might print a lot of errors to the console,
2575 especially if you are using gpm.
2576
2577config APM_ALLOW_INTS
2578 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002579 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002580 Normally we disable external interrupts while we are making calls to
2581 the APM BIOS as a measure to lessen the effects of a badly behaving
2582 BIOS implementation. The BIOS should reenable interrupts if it
2583 needs to. Unfortunately, some BIOSes do not -- especially those in
2584 many of the newer IBM Thinkpads. If you experience hangs when you
2585 suspend, try setting this to Y. Otherwise, say N.
2586
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002587endif # APM
2588
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002589source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002590
2591source "drivers/cpuidle/Kconfig"
2592
Andy Henroid27471fd2008-10-09 11:45:22 -07002593source "drivers/idle/Kconfig"
2594
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002595endmenu
2596
2597
2598menu "Bus options (PCI etc.)"
2599
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002600choice
2601 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002602 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002603 default PCI_GOANY
2604 ---help---
2605 On PCI systems, the BIOS can be used to detect the PCI devices and
2606 determine their configuration. However, some old PCI motherboards
2607 have BIOS bugs and may crash if this is done. Also, some embedded
2608 PCI-based systems don't have any BIOS at all. Linux can also try to
2609 detect the PCI hardware directly without using the BIOS.
2610
2611 With this option, you can specify how Linux should detect the
2612 PCI devices. If you choose "BIOS", the BIOS will be used,
2613 if you choose "Direct", the BIOS won't be used, and if you
2614 choose "MMConfig", then PCI Express MMCONFIG will be used.
2615 If you choose "Any", the kernel will try MMCONFIG, then the
2616 direct access method and falls back to the BIOS if that doesn't
2617 work. If unsure, go with the default, which is "Any".
2618
2619config PCI_GOBIOS
2620 bool "BIOS"
2621
2622config PCI_GOMMCONFIG
2623 bool "MMConfig"
2624
2625config PCI_GODIRECT
2626 bool "Direct"
2627
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002628config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002629 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002630 depends on OLPC
2631
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002632config PCI_GOANY
2633 bool "Any"
2634
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002635endchoice
2636
2637config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002638 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002639 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002640
2641# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2642config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002643 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002644 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002645
2646config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002647 bool "Support mmconfig PCI config space access" if X86_64
2648 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002649 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002650 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002651
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002652config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002653 def_bool y
2654 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002655
Alex Nixonb5401a92010-03-18 16:31:34 -04002656config PCI_XEN
2657 def_bool y
2658 depends on PCI && XEN
2659 select SWIOTLB_XEN
2660
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002661config MMCONF_FAM10H
2662 def_bool y
2663 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002664
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
William Breathitt Gray3a495512016-05-27 18:08:27 -04002678config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002679 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002680 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002681 Expose ISA bus device drivers and options available for selection and
2682 configuration. Enable this option if your target machine has an ISA
2683 bus. ISA is an older system, displaced by PCI and newer bus
2684 architectures -- if your target machine is modern, it probably does
2685 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002686
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
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002708config SCx200
2709 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002710 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002711 This provides basic support for National Semiconductor's
2712 (now AMD's) Geode processors. The driver probes for the
2713 PCI-IDs of several on-chip devices, so its a good dependency
2714 for other scx200_* drivers.
2715
2716 If compiled as a module, the driver is named scx200.
2717
2718config SCx200HR_TIMER
2719 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002720 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002721 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002722 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002723 This driver provides a clocksource built upon the on-chip
2724 27MHz high-resolution timer. Its also a workaround for
2725 NSC Geode SC-1100's buggy TSC, which loses time when the
2726 processor goes idle (as is done by the scheduler). The
2727 other workaround is idle=poll boot option.
2728
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002729config OLPC
2730 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002731 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002732 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002733 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002734 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002735 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002736 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002737 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002738 Add support for detecting the unique features of the OLPC
2739 XO hardware.
2740
Daniel Drakea3128582011-06-25 17:34:10 +01002741config OLPC_XO1_PM
2742 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002743 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002744 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002745 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002746
Daniel Drakecfee9592011-06-25 17:34:17 +01002747config OLPC_XO1_RTC
2748 bool "OLPC XO-1 Real Time Clock"
2749 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2750 ---help---
2751 Add support for the XO-1 real time clock, which can be used as a
2752 programmable wakeup source.
2753
Daniel Drake7feda8e2011-06-25 17:34:12 +01002754config OLPC_XO1_SCI
2755 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002756 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002757 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002758 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002759 ---help---
2760 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002761 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002762 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002763 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002764 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002765 - AC adapter status updates
2766 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002767
Daniel Drakea0f30f52011-06-25 17:34:18 +01002768config OLPC_XO15_SCI
2769 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002770 depends on OLPC && ACPI
2771 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002772 ---help---
2773 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2774 - EC-driven system wakeups
2775 - AC adapter status updates
2776 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002777
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002778config ALIX
2779 bool "PCEngines ALIX System Support (LED setup)"
2780 select GPIOLIB
2781 ---help---
2782 This option enables system support for the PCEngines ALIX.
2783 At present this just sets up LEDs for GPIO control on
2784 ALIX2/3/6 boards. However, other system specific setup should
2785 get added here.
2786
2787 Note: You must still enable the drivers for GPIO and LED support
2788 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2789
2790 Note: You have to set alix.force=1 for boards with Award BIOS.
2791
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002792config NET5501
2793 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2794 select GPIOLIB
2795 ---help---
2796 This option enables system support for the Soekris Engineering net5501.
2797
Philip A. Prindeville31970592012-01-14 01:45:39 -07002798config GEOS
2799 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2800 select GPIOLIB
2801 depends on DMI
2802 ---help---
2803 This option enables system support for the Traverse Technologies GEOS.
2804
Vivien Didelot7d029122013-01-04 16:18:14 -05002805config TS5500
2806 bool "Technologic Systems TS-5500 platform support"
2807 depends on MELAN
2808 select CHECK_SIGNATURE
2809 select NEW_LEDS
2810 select LEDS_CLASS
2811 ---help---
2812 This option enables system support for the Technologic Systems TS-5500.
2813
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002814endif # X86_32
2815
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002816config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002817 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002818 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002819
David Herrmanne3263ab2013-08-02 14:05:22 +02002820config X86_SYSFB
2821 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2822 help
2823 Firmwares often provide initial graphics framebuffers so the BIOS,
2824 bootloader or kernel can show basic video-output during boot for
2825 user-guidance and debugging. Historically, x86 used the VESA BIOS
2826 Extensions and EFI-framebuffers for this, which are mostly limited
2827 to x86.
2828 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2829 framebuffers so the new generic system-framebuffer drivers can be
2830 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002831 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002832 drivers like efifb, vesafb and uvesafb can pick it up.
2833 If this option is not selected, all system framebuffers are always
2834 marked as fallback platform framebuffers as usual.
2835
2836 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2837 not be able to pick up generic system framebuffers if this option
2838 is selected. You are highly encouraged to enable simplefb as
2839 replacement if you select this option. simplefb can correctly deal
2840 with generic system framebuffers. But you should still keep vesafb
2841 and others enabled as fallback if a system framebuffer is
2842 incompatible with simplefb.
2843
2844 If unsure, say Y.
2845
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002846endmenu
2847
2848
Christoph Hellwig15724972018-07-31 13:39:30 +02002849menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002850
2851config IA32_EMULATION
2852 bool "IA32 Emulation"
2853 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002854 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002855 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002856 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002857 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002858 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002859 Include code to run legacy 32-bit programs under a
2860 64-bit kernel. You should likely turn this on, unless you're
2861 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002862
2863config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002864 tristate "IA32 a.out support"
2865 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002866 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002867 ---help---
2868 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002869
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002870config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002871 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002872 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002873 ---help---
2874 Include code to run binaries for the x32 native 32-bit ABI
2875 for 64-bit processors. An x32 process gets access to the
2876 full 64-bit register file and wide data path while leaving
2877 pointers at 32 bits for smaller memory footprint.
2878
2879 You will need a recent binutils (2.22 or later) with
2880 elf32_x86_64 support enabled to compile a kernel with this
2881 option set.
2882
Ingo Molnar953fee12016-11-15 10:22:52 +01002883config COMPAT_32
2884 def_bool y
2885 depends on IA32_EMULATION || X86_32
2886 select HAVE_UID16
2887 select OLD_SIGSUSPEND3
2888
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002889config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002890 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002891 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002892
Jan Beulich3120e252012-09-10 12:41:45 +01002893if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002894config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002895 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002896
2897config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002898 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002899 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002900endif
David Howellsee009e4a02011-03-07 15:06:20 +00002901
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002902endmenu
2903
2904
Keith Packarde5beae12008-11-03 18:21:45 +01002905config HAVE_ATOMIC_IOMAP
2906 def_bool y
2907 depends on X86_32
2908
Alessandro Rubini4692d772012-04-04 19:39:58 +02002909config X86_DEV_DMA_OPS
2910 bool
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002911
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002912source "drivers/firmware/Kconfig"
2913
Avi Kivityedf88412007-12-16 11:02:48 +02002914source "arch/x86/kvm/Kconfig"