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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
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030071 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050072 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Ingo Molnarc763ea22016-11-15 10:26:39 +010073 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070074 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070075 select ARCH_HAS_PTE_SPECIAL
Kees Cook39208aa2017-09-02 13:09:46 -070076 select ARCH_HAS_REFCOUNT
Dan Williams0aed55a2017-05-29 12:22:50 -070077 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070078 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010079 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070080 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080081 select ARCH_HAS_STRICT_KERNEL_RWX
82 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050083 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Andrey Ryabininc6d30852016-01-20 15:00:55 -080084 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020085 select ARCH_HAVE_NMI_SAFE_CMPXCHG
86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040087 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080088 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020089 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020090 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020092 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
93 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select ARCH_USE_QUEUED_RWLOCKS
95 select ARCH_USE_QUEUED_SPINLOCKS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070096 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Ingo Molnarc763ea22016-11-15 10:26:39 +010097 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -070098 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -070099 select ARCH_WANTS_THP_SWAP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select BUILDTIME_EXTABLE_SORT
101 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
103 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700105 select EDAC_ATOMIC_SCRUB
106 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200107 select GENERIC_CLOCKEVENTS
108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
109 select GENERIC_CLOCKEVENTS_MIN_ADJUST
110 select GENERIC_CMOS_UPDATE
111 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100112 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200113 select GENERIC_EARLY_IOREMAP
114 select GENERIC_FIND_FIRST_BIT
115 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200118 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200120 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200121 select GENERIC_IRQ_SHOW
122 select GENERIC_PENDING_IRQ if SMP
123 select GENERIC_SMP_IDLE_THREAD
124 select GENERIC_STRNCPY_FROM_USER
125 select GENERIC_STRNLEN_USER
126 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100127 select GENERIC_GETTIMEOFDAY
Christoph Hellwig39656e82019-07-11 20:56:49 -0700128 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200129 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200130 select HAVE_ACPI_APEI if ACPI
131 select HAVE_ACPI_APEI_NMI if ACPI
132 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200133 select HAVE_ARCH_AUDITSYSCALL
134 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
135 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700136 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800137 select HAVE_ARCH_KASAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800139 select HAVE_ARCH_MMAP_RND_BITS if MMU
140 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300141 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700142 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200143 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700144 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300145 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select HAVE_ARCH_TRACEHOOK
147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700149 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100150 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900151 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select HAVE_CMPXCHG_DOUBLE
153 select HAVE_CMPXCHG_LOCAL
154 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700155 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200156 select HAVE_C_RECORDMCOUNT
157 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700158 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400159 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900160 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Wang YanQing03f57812018-05-03 14:10:43 +0800161 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700162 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100163 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700164 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700165 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400166 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200167 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200168 select HAVE_FUNCTION_GRAPH_TRACER
169 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200170 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530171 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200172 select HAVE_IDE
173 select HAVE_IOREMAP_PROT
174 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
175 select HAVE_IRQ_TIME_ACCOUNTING
176 select HAVE_KERNEL_BZIP2
177 select HAVE_KERNEL_GZIP
178 select HAVE_KERNEL_LZ4
179 select HAVE_KERNEL_LZMA
180 select HAVE_KERNEL_LZO
181 select HAVE_KERNEL_XZ
182 select HAVE_KPROBES
183 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900184 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200185 select HAVE_KRETPROBES
186 select HAVE_KVM
187 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200188 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200189 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500190 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800191 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700192 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200193 select HAVE_OPROFILE
194 select HAVE_OPTPROBES
195 select HAVE_PCSPKR_PLATFORM
196 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200197 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700198 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100199 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200200 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200201 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstra48a8b972018-08-22 17:30:16 +0200202 select HAVE_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200203 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200204 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900205 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900206 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100207 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400208 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200209 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200210 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300211 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100212 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200213 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100214 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200215 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100216 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000217 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200218 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500219 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200220 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200221 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500222 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200223 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700224 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200225 select USER_STACKTRACE_SUPPORT
226 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800228 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530229
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200230config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100231 def_bool y
232 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200233
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700234config OUTPUT_FORMAT
235 string
236 default "elf32-i386" if X86_32
237 default "elf64-x86-64" if X86_64
238
Sam Ravnborg73531902008-05-25 23:03:18 +0200239config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200240 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200241 default "arch/x86/configs/i386_defconfig" if X86_32
242 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200243
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100244config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100245 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100246
247config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100248 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100249
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100250config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100251 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100252
Daniel Cashman9e08f572016-01-14 15:20:06 -0800253config ARCH_MMAP_RND_BITS_MIN
254 default 28 if 64BIT
255 default 8
256
257config ARCH_MMAP_RND_BITS_MAX
258 default 32 if 64BIT
259 default 16
260
261config ARCH_MMAP_RND_COMPAT_BITS_MIN
262 default 8
263
264config ARCH_MMAP_RND_COMPAT_BITS_MAX
265 default 16
266
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100267config SBUS
268 bool
269
270config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100271 def_bool y
272 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100273
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100274config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100275 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100276 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000277 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
278
279config GENERIC_BUG_RELATIVE_POINTERS
280 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100281
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100282config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100283 def_bool y
284 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100285
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100286config GENERIC_CALIBRATE_DELAY
287 def_bool y
288
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800289config ARCH_HAS_CPU_RELAX
290 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100291
Pekka Enberg1b27d052008-04-28 02:12:22 -0700292config ARCH_HAS_CACHE_LINE_SIZE
293 def_bool y
294
Dave Hansen316d0972018-04-20 15:20:28 -0700295config ARCH_HAS_FILTER_PGPROT
296 def_bool y
297
Mike Travisdd5af902008-01-30 13:33:32 +0100298config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900299 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100300
Tejun Heo08fc4582009-08-14 15:00:49 +0900301config NEED_PER_CPU_EMBED_FIRST_CHUNK
302 def_bool y
303
304config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900305 def_bool y
306
Johannes Berg801e4062007-12-08 02:12:39 +0100307config ARCH_HIBERNATION_POSSIBLE
308 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100309
Johannes Bergf4cb5702007-12-08 02:14:00 +0100310config ARCH_SUSPEND_POSSIBLE
311 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100312
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>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300405 <file:Documentation/admin-guide/lockup-watchdogs.rst> 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
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300799 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100800 default y
801 ---help---
802 This option enables various optimizations for running under the KVM
803 hypervisor. It includes a paravirtualized clock, so that instead
804 of relying on a PIT (or probably other) emulation by the
805 underlying device model, the host provides the guest with
806 timing infrastructure such as time of day, and system time
807
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300808config ARCH_CPUIDLE_HALTPOLL
809 def_bool n
810 prompt "Disable host haltpoll when loading haltpoll driver"
811 help
812 If virtualized under KVM, disable host haltpoll.
813
Maran Wilson77336072018-12-10 11:07:28 -0800814config PVH
815 bool "Support for running PVH guests"
816 ---help---
817 This option enables the PVH entry point for guest virtual machines
818 as specified in the x86/HVM direct boot ABI.
819
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530820config KVM_DEBUG_FS
821 bool "Enable debug information for KVM Guests in debugfs"
822 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530823 ---help---
824 This option enables collection of various statistics for KVM guest.
825 Statistics are displayed in debugfs filesystem. Enabling this option
826 may incur significant overhead.
827
Borislav Petkov6276a072013-03-04 21:20:21 +0100828config PARAVIRT_TIME_ACCOUNTING
829 bool "Paravirtual steal time accounting"
830 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100831 ---help---
832 Select this option to enable fine granularity task steal time
833 accounting. Time spent executing other tasks in parallel with
834 the current vCPU is discounted from the vCPU power. To account for
835 that, there can be a small performance impact.
836
837 If in doubt, say N here.
838
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200839config PARAVIRT_CLOCK
840 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200841
Jan Kiszka4a362602017-11-27 09:11:46 +0100842config JAILHOUSE_GUEST
843 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100844 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100845 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100846 ---help---
847 This option allows to run Linux as guest in a Jailhouse non-root
848 cell. You can leave this option disabled if you only want to start
849 Jailhouse and run Linux afterwards in the root cell.
850
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800851config ACRN_GUEST
852 bool "ACRN Guest support"
853 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800854 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800855 help
856 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
857 a flexible, lightweight reference open-source hypervisor, built with
858 real-time and safety-criticality in mind. It is built for embedded
859 IOT with small footprint and real-time features. More details can be
860 found in https://projectacrn.org/.
861
Borislav Petkov6276a072013-03-04 21:20:21 +0100862endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400863
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100864source "arch/x86/Kconfig.cpu"
865
866config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100867 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100868 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100869 ---help---
870 Use the IA-PC HPET (High Precision Event Timer) to manage
871 time in preference to the PIT and RTC, if a HPET is
872 present.
873 HPET is the next generation timer replacing legacy 8254s.
874 The HPET provides a stable time base on SMP
875 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200876 as it is off-chip. The interface used is documented
877 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100878
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100879 You can safely choose Y here. However, HPET will only be
880 activated if the platform and the BIOS support this feature.
881 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100882
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100883 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100884
885config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100886 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800887 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100888
Jacob Panbb24c472009-09-02 07:37:17 -0700889config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000890 def_bool y if X86_INTEL_MID
891 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100892 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000893 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700894 help
895 APB timer is the replacement for 8254, HPET on X86 MID platforms.
896 The APBT provides a stable time base on SMP
897 systems, unlike the TSC, but it is more expensive to access,
898 as it is off-chip. APB timers are always running regardless of CPU
899 C states, they are used as per CPU clockevent device when possible.
900
David Rientjes6a108a12011-01-20 14:44:16 -0800901# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100902# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700903config DMI
904 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800905 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800906 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100907 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700908 Enabled scanning of DMI to identify machine quirks. Say Y
909 here unless you have verified that your setup is not
910 affected by entries in the DMI blacklist. Required by PNP
911 BIOS code.
912
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100913config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700914 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200915 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100916 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200917 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100918 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200919 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
920 GART based hardware IOMMUs.
921
922 The GART supports full DMA access for devices with 32-bit access
923 limitations, on systems with more than 3 GB. This is usually needed
924 for USB, sound, many IDE/SATA chipsets and some other devices.
925
926 Newer systems typically have a modern AMD IOMMU, supported via
927 the CONFIG_AMD_IOMMU=y config option.
928
929 In normal configurations this driver is only active when needed:
930 there's more than 3 GB of memory and the system contains a
931 32-bit limited device.
932
933 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100934
935config CALGARY_IOMMU
936 bool "IBM Calgary IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200937 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100938 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700939 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100940 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100941 Support for hardware IOMMUs in IBM's xSeries x366 and x460
942 systems. Needed to run systems with more than 3GB of memory
943 properly with 32-bit PCI devices that do not support DAC
944 (Double Address Cycle). Calgary also supports bus level
945 isolation, where all DMAs pass through the IOMMU. This
946 prevents them from going anywhere except their intended
947 destination. This catches hard-to-find kernel bugs and
948 mis-behaving drivers and devices that do not use the DMA-API
949 properly to set up their DMA buffers. The IOMMU can be
950 turned off at boot time with the iommu=off parameter.
951 Normally the kernel will make the right choice by itself.
952 If unsure, say Y.
953
954config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100955 def_bool y
956 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100957 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100958 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100959 Should Calgary be enabled by default? if you choose 'y', Calgary
960 will be used (if it exists). If you choose 'n', Calgary will not be
961 used even if it exists. If you choose 'n' and would like to use
962 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
963 If unsure, say Y.
964
Mike Travis1184dc22008-05-12 21:21:12 +0200965config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200966 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700967 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800968 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100969 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200970 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200971 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100972
Ingo Molnaraec64872018-02-10 12:36:29 +0100973#
974# The maximum number of CPUs supported:
975#
976# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
977# and which can be configured interactively in the
978# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
979#
980# The ranges are different on 32-bit and 64-bit kernels, depending on
981# hardware capabilities and scalability features of the kernel.
982#
983# ( If MAXSMP is enabled we just use the highest possible value and disable
984# interactive configuration. )
985#
986
987config NR_CPUS_RANGE_BEGIN
988 int
989 default NR_CPUS_RANGE_END if MAXSMP
990 default 1 if !SMP
991 default 2
992
993config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800994 int
995 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100996 default 64 if SMP && X86_BIGSMP
997 default 8 if SMP && !X86_BIGSMP
998 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800999
Ingo Molnaraec64872018-02-10 12:36:29 +01001000config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001001 int
1002 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001003 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
1004 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
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_32
Ingo Molnaraec64872018-02-10 12:36:29 +01001010 default 32 if X86_BIGSMP
1011 default 8 if SMP
1012 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001013
Ingo Molnaraec64872018-02-10 12:36:29 +01001014config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001015 int
1016 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001017 default 8192 if MAXSMP
1018 default 64 if SMP
1019 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001020
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001021config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -08001022 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +01001023 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1024 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001025 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001026 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001027 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001028 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001029 minimum value which makes sense is 2.
1030
Ingo Molnaraec64872018-02-10 12:36:29 +01001031 This is purely to save memory: each supported CPU adds about 8KB
1032 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001033
1034config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001035 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001036
1037config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001038 def_bool y
1039 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001040 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001041 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001042 Multi-core scheduler support improves the CPU scheduler's decision
1043 making when dealing with multi-core CPU chips at a cost of slightly
1044 increased overhead in some places. If unsure say N here.
1045
Tim Chende966cf2016-11-29 10:43:27 -08001046config SCHED_MC_PRIO
1047 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001048 depends on SCHED_MC && CPU_SUP_INTEL
1049 select X86_INTEL_PSTATE
1050 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001051 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001052 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001053 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1054 core ordering determined at manufacturing time, which allows
1055 certain cores to reach higher turbo frequencies (when running
1056 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001057
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001058 Enabling this kernel feature teaches the scheduler about
1059 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1060 scheduler's CPU selection logic accordingly, so that higher
1061 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001062
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001063 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001064
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001065 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001066
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001067config UP_LATE_INIT
1068 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +01001069 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001070
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001071config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001072 bool "Local APIC support on uniprocessors" if !PCI_MSI
1073 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001074 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001075 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001076 A local APIC (Advanced Programmable Interrupt Controller) is an
1077 integrated interrupt controller in the CPU. If you have a single-CPU
1078 system which has a processor with a local APIC, you can say Y here to
1079 enable and use it. If you say Y here even though your machine doesn't
1080 have a local APIC, then the kernel will still run with no slowdown at
1081 all. The local APIC supports CPU-generated self-interrupts (timer,
1082 performance counters), and the NMI watchdog which detects hard
1083 lockups.
1084
1085config X86_UP_IOAPIC
1086 bool "IO-APIC support on uniprocessors"
1087 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001088 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001089 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1090 SMP-capable replacement for PC-style interrupt controllers. Most
1091 SMP systems and many recent uniprocessor systems have one.
1092
1093 If you have a single-CPU system with an IO-APIC, you can say Y here
1094 to use it. If you say Y here even though your machine doesn't have
1095 an IO-APIC, then the kernel will still run with no slowdown at all.
1096
1097config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001098 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001099 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001100 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001101 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001102
1103config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001104 def_bool y
1105 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001106
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001107config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1108 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001109 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001110 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001111 This option enables a workaround that fixes a source of
1112 spurious interrupts. This is recommended when threaded
1113 interrupt handling is used on systems where the generation of
1114 superfluous "boot interrupts" cannot be disabled.
1115
1116 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1117 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1118 kernel does during interrupt handling). On chipsets where this
1119 boot IRQ generation cannot be disabled, this workaround keeps
1120 the original IRQ line masked so that only the equivalent "boot
1121 IRQ" is delivered to the CPUs. The workaround also tells the
1122 kernel to set up the IRQ handler on the boot IRQ line. In this
1123 way only one interrupt is delivered to the kernel. Otherwise
1124 the spurious second interrupt may cause the kernel to bring
1125 down (vital) interrupt lines.
1126
1127 Only affects "broken" chipsets. Interrupt sharing may be
1128 increased on these systems.
1129
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001130config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001131 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001132 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001133 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001134 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001135 Machine Check support allows the processor to notify the
1136 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001137 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001138 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001139
Tony Luck5de97c92017-03-27 11:33:03 +02001140config X86_MCELOG_LEGACY
1141 bool "Support for deprecated /dev/mcelog character device"
1142 depends on X86_MCE
1143 ---help---
1144 Enable support for /dev/mcelog which is needed by the old mcelog
1145 userspace logging daemon. Consider switching to the new generation
1146 rasdaemon solution.
1147
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001148config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001149 def_bool y
1150 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001151 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001152 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001153 Additional support for intel specific MCE features such as
1154 the thermal monitor.
1155
1156config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001157 def_bool y
1158 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001159 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001160 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001161 Additional support for AMD specific MCE features such as
1162 the DRAM Error Threshold.
1163
Andi Kleen4efc0672009-04-28 19:07:31 +02001164config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001165 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001166 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001167 ---help---
1168 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001169 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001170 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001171
Andi Kleenb2762682009-02-12 13:49:31 +01001172config X86_MCE_THRESHOLD
1173 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001174 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001175
Andi Kleenea149b32009-04-29 19:31:00 +02001176config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001177 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001178 tristate "Machine check injector support"
1179 ---help---
1180 Provide support for injecting machine checks for testing purposes.
1181 If you don't know what a machine check is and you don't do kernel
1182 QA it is safe to say n.
1183
Andi Kleen4efc0672009-04-28 19:07:31 +02001184config X86_THERMAL_VECTOR
1185 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001186 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001187
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001188source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001189
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001190config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001191 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001192 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001193 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001194 This option allows user programs to put the CPU into V8086
1195 mode, which is an 80286-era approximation of 16-bit real mode.
1196
1197 Some very old versions of X and/or vbetool require this option
1198 for user mode setting. Similarly, DOSEMU will use it if
1199 available to accelerate real mode DOS programs. However, any
1200 recent version of DOSEMU, X, or vbetool should be fully
1201 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001202 fall back to software emulation. Nevertheless, if you are using
1203 a 16-bit DOS program where 16-bit performance matters, vm86
1204 mode might be faster than emulation and you might want to
1205 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001206
Ingo Molnar1e642812015-09-05 08:58:10 +02001207 Note that any app that works on a 64-bit kernel is unlikely to
1208 need this option, as 64-bit kernels don't, and can't, support
1209 V8086 mode. This option is also unrelated to 16-bit protected
1210 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001211
Ingo Molnar1e642812015-09-05 08:58:10 +02001212 Enabling this option increases the complexity of the kernel
1213 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001214
Ingo Molnar1e642812015-09-05 08:58:10 +02001215 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001216
1217config VM86
1218 bool
1219 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001220
1221config X86_16BIT
1222 bool "Enable support for 16-bit segments" if EXPERT
1223 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001224 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001225 ---help---
1226 This option is required by programs like Wine to run 16-bit
1227 protected mode legacy code on x86 processors. Disabling
1228 this option saves about 300 bytes on i386, or around 6K text
1229 plus 16K runtime memory on x86-64,
1230
1231config X86_ESPFIX32
1232 def_bool y
1233 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001234
H. Peter Anvin197725d2014-05-04 10:00:49 -07001235config X86_ESPFIX64
1236 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001237 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001238
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001239config X86_VSYSCALL_EMULATION
1240 bool "Enable vsyscall emulation" if EXPERT
1241 default y
1242 depends on X86_64
1243 ---help---
1244 This enables emulation of the legacy vsyscall page. Disabling
1245 it is roughly equivalent to booting with vsyscall=none, except
1246 that it will also disable the helpful warning if a program
1247 tries to use a vsyscall. With this option set to N, offending
1248 programs will just segfault, citing addresses of the form
1249 0xffffffffff600?00.
1250
1251 This option is required by many programs built before 2013, and
1252 care should be used even with newer programs if set to N.
1253
1254 Disabling this option saves about 7K of kernel size and
1255 possibly 4K of additional runtime pagetable memory.
1256
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001257config X86_IOPL_EMULATION
1258 bool "IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001259 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001260 ---help---
1261 Legacy IOPL support is an overbroad mechanism which allows user
1262 space aside of accessing all 65536 I/O ports also to disable
1263 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1264 capabilities and permission from potentially active security
1265 modules.
1266
1267 The emulation restricts the functionality of the syscall to
1268 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001269 ability to disable interrupts from user space which would be
1270 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001271
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001272config TOSHIBA
1273 tristate "Toshiba Laptop support"
1274 depends on X86_32
1275 ---help---
1276 This adds a driver to safely access the System Management Mode of
1277 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1278 not work on models with a Phoenix BIOS. The System Management Mode
1279 is used to set the BIOS and power saving options on Toshiba portables.
1280
1281 For information on utilities to make use of this driver see the
1282 Toshiba Linux utilities web site at:
1283 <http://www.buzzard.org.uk/toshiba/>.
1284
1285 Say Y if you intend to run this kernel on a Toshiba portable.
1286 Say N otherwise.
1287
1288config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001289 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001290 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001291 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001292 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001293 This option enables legacy /proc/i8k userspace interface in hwmon
1294 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1295 temperature and allows controlling fan speeds of Dell laptops via
1296 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1297 it reports also power and hotkey status. For fan speed control is
1298 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001299
Pali Rohár039ae582015-05-14 13:16:37 +02001300 Say Y if you intend to run this kernel on old Dell laptops or want to
1301 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001302 Say N otherwise.
1303
1304config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001305 bool "Enable X86 board specific fixups for reboot"
1306 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001307 ---help---
1308 This enables chipset and/or board specific fixups to be done
1309 in order to get reboot to work correctly. This is only needed on
1310 some combinations of hardware and BIOS. The symptom, for which
1311 this config is intended, is when reboot ends with a stalled/hung
1312 system.
1313
1314 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001315 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001316
1317 Say Y if you want to enable the fixup. Currently, it's safe to
1318 enable this option even if you don't need it.
1319 Say N otherwise.
1320
1321config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001322 bool "CPU microcode loading support"
1323 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001324 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001325 select FW_LOADER
1326 ---help---
1327 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001328 Intel and AMD processors. The Intel support is for the IA32 family,
1329 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1330 AMD support is for families 0x10 and later. You will obviously need
1331 the actual microcode binary data itself which is not shipped with
1332 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001333
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001334 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001335 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001336 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1337 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001338
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001339 In addition, you can build the microcode into the kernel. For that you
1340 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1341 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001342
Peter Oruba8d86f392008-07-28 18:44:21 +02001343config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001344 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001345 depends on MICROCODE
1346 default MICROCODE
1347 select FW_LOADER
1348 ---help---
1349 This options enables microcode patch loading support for Intel
1350 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001351
Alanb8989db2014-01-20 18:01:56 +00001352 For the current Intel microcode data package go to
1353 <https://downloadcenter.intel.com> and search for
1354 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001355
Peter Oruba80cc9f12008-07-28 18:44:22 +02001356config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001357 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001358 depends on MICROCODE
1359 select FW_LOADER
1360 ---help---
1361 If you select this option, microcode patch loading support for AMD
1362 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001363
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001364config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001365 bool "Ancient loading interface (DEPRECATED)"
1366 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001367 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001368 ---help---
1369 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1370 which was used by userspace tools like iucode_tool and microcode.ctl.
1371 It is inadequate because it runs too late to be able to properly
1372 load microcode on a machine and it needs special tools. Instead, you
1373 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001374 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001375
1376config X86_MSR
1377 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001378 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001379 This device gives privileged processes access to the x86
1380 Model-Specific Registers (MSRs). It is a character device with
1381 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1382 MSR accesses are directed to a specific CPU on multi-processor
1383 systems.
1384
1385config X86_CPUID
1386 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001387 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001388 This device gives processes access to the x86 CPUID instruction to
1389 be executed on a specific processor. It is a character device
1390 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1391 /dev/cpu/31/cpuid.
1392
1393choice
1394 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001395 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001396 depends on X86_32
1397
1398config NOHIGHMEM
1399 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001400 ---help---
1401 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1402 However, the address space of 32-bit x86 processors is only 4
1403 Gigabytes large. That means that, if you have a large amount of
1404 physical memory, not all of it can be "permanently mapped" by the
1405 kernel. The physical memory that's not permanently mapped is called
1406 "high memory".
1407
1408 If you are compiling a kernel which will never run on a machine with
1409 more than 1 Gigabyte total physical RAM, answer "off" here (default
1410 choice and suitable for most users). This will result in a "3GB/1GB"
1411 split: 3GB are mapped so that each process sees a 3GB virtual memory
1412 space and the remaining part of the 4GB virtual memory space is used
1413 by the kernel to permanently map as much physical memory as
1414 possible.
1415
1416 If the machine has between 1 and 4 Gigabytes physical RAM, then
1417 answer "4GB" here.
1418
1419 If more than 4 Gigabytes is used then answer "64GB" here. This
1420 selection turns Intel PAE (Physical Address Extension) mode on.
1421 PAE implements 3-level paging on IA32 processors. PAE is fully
1422 supported by Linux, PAE mode is implemented on all recent Intel
1423 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1424 then the kernel will not boot on CPUs that don't support PAE!
1425
1426 The actual amount of total physical memory will either be
1427 auto detected or can be forced by using a kernel command line option
1428 such as "mem=256M". (Try "man bootparam" or see the documentation of
1429 your boot loader (lilo or loadlin) about how to pass options to the
1430 kernel at boot time.)
1431
1432 If unsure, say "off".
1433
1434config HIGHMEM4G
1435 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001436 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001437 Select this if you have a 32-bit processor and between 1 and 4
1438 gigabytes of physical RAM.
1439
1440config HIGHMEM64G
1441 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001442 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001443 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001444 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001445 Select this if you have a 32-bit processor and more than 4
1446 gigabytes of physical RAM.
1447
1448endchoice
1449
1450choice
David Rientjes6a108a12011-01-20 14:44:16 -08001451 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001452 default VMSPLIT_3G
1453 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001454 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001455 Select the desired split between kernel and user memory.
1456
1457 If the address range available to the kernel is less than the
1458 physical memory installed, the remaining memory will be available
1459 as "high memory". Accessing high memory is a little more costly
1460 than low memory, as it needs to be mapped into the kernel first.
1461 Note that increasing the kernel address space limits the range
1462 available to user programs, making the address space there
1463 tighter. Selecting anything other than the default 3G/1G split
1464 will also likely make your kernel incompatible with binary-only
1465 kernel modules.
1466
1467 If you are not absolutely sure what you are doing, leave this
1468 option alone!
1469
1470 config VMSPLIT_3G
1471 bool "3G/1G user/kernel split"
1472 config VMSPLIT_3G_OPT
1473 depends on !X86_PAE
1474 bool "3G/1G user/kernel split (for full 1G low memory)"
1475 config VMSPLIT_2G
1476 bool "2G/2G user/kernel split"
1477 config VMSPLIT_2G_OPT
1478 depends on !X86_PAE
1479 bool "2G/2G user/kernel split (for full 2G low memory)"
1480 config VMSPLIT_1G
1481 bool "1G/3G user/kernel split"
1482endchoice
1483
1484config PAGE_OFFSET
1485 hex
1486 default 0xB0000000 if VMSPLIT_3G_OPT
1487 default 0x80000000 if VMSPLIT_2G
1488 default 0x78000000 if VMSPLIT_2G_OPT
1489 default 0x40000000 if VMSPLIT_1G
1490 default 0xC0000000
1491 depends on X86_32
1492
1493config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001494 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001495 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001496
1497config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001498 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001499 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001500 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001501 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001502 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001503 PAE is required for NX support, and furthermore enables
1504 larger swapspace support for non-overcommit purposes. It
1505 has the cost of more pagetable lookup overhead, and also
1506 consumes more pagetable space per process.
1507
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001508config X86_5LEVEL
1509 bool "Enable 5-level page tables support"
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001510 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001511 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001512 depends on X86_64
1513 ---help---
1514 5-level paging enables access to larger address space:
1515 upto 128 PiB of virtual address space and 4 PiB of
1516 physical address space.
1517
1518 It will be supported by future Intel CPUs.
1519
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001520 A kernel with the option enabled can be booted on machines that
1521 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001522
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001523 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001524 information.
1525
1526 Say N if unsure.
1527
Ingo Molnar10971ab2015-03-05 08:18:23 +01001528config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001529 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001530 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001531 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001532 Certain kernel features effectively disable kernel
1533 linear 1 GB mappings (even if the CPU otherwise
1534 supports them), so don't confuse the user by printing
1535 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001536
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001537config X86_CPA_STATISTICS
1538 bool "Enable statistic for Change Page Attribute"
1539 depends on DEBUG_FS
1540 ---help---
1541 Expose statistics about the Change Page Attribute mechanims, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001542 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001543 page mappings when mapping protections are changed.
1544
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001545config AMD_MEM_ENCRYPT
1546 bool "AMD Secure Memory Encryption (SME) support"
1547 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001548 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001549 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001550 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001551 ---help---
1552 Say yes to enable support for the encryption of system memory.
1553 This requires an AMD processor that supports Secure Memory
1554 Encryption (SME).
1555
1556config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1557 bool "Activate AMD Secure Memory Encryption (SME) by default"
1558 default y
1559 depends on AMD_MEM_ENCRYPT
1560 ---help---
1561 Say yes to have system memory encrypted by default if running on
1562 an AMD processor that supports Secure Memory Encryption (SME).
1563
1564 If set to Y, then the encryption of system memory can be
1565 deactivated with the mem_encrypt=off command line option.
1566
1567 If set to N, then the encryption of system memory can be
1568 activated with the mem_encrypt=on command line option.
1569
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001570# Common NUMA Features
1571config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001572 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001573 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001574 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1575 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001576 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001577 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001578
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001579 The kernel will try to allocate memory used by a CPU on the
1580 local memory controller of the CPU and add some more
1581 NUMA awareness to the kernel.
1582
Ingo Molnarc280ea52008-11-08 13:29:45 +01001583 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001584 (or later), AMD Opteron, or EM64T NUMA.
1585
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001586 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001587 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001588
1589 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001590
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001591config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001592 def_bool y
1593 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001594 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001595 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001596 Enable AMD NUMA node topology detection. You should say Y here if
1597 you have a multi processor AMD system. This uses an old method to
1598 read the NUMA configuration directly from the builtin Northbridge
1599 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1600 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001601
1602config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001603 def_bool y
1604 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001605 depends on X86_64 && NUMA && ACPI && PCI
1606 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001607 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001608 Enable ACPI SRAT based node topology detection.
1609
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001610# Some NUMA nodes have memory ranges that span
1611# other nodes. Even though a pfn is valid and
1612# between a node's start and end pfns, it may not
1613# reside on that node. See memmap_init_zone()
1614# for details.
1615config NODES_SPAN_OTHER_NODES
1616 def_bool y
1617 depends on X86_64_ACPI_NUMA
1618
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001619config NUMA_EMU
1620 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001621 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001622 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001623 Enable NUMA emulation. A flat machine will be split
1624 into virtual nodes when booted with "numa=fake=N", where N is the
1625 number of nodes. This is only useful for debugging.
1626
1627config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001628 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001629 range 1 10
1630 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001631 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001632 default "3"
1633 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001634 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001635 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001636 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001637
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001638config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001639 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001640 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001641
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001642config ARCH_FLATMEM_ENABLE
1643 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001644 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001645
1646config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001647 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001648 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001649 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001650
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001651config ARCH_SPARSEMEM_ENABLE
1652 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001653 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001654 select SPARSEMEM_STATIC if X86_32
1655 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1656
Tejun Heo3b166512011-04-01 11:15:12 +02001657config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001658 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001659
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001660config ARCH_SELECT_MEMORY_MODEL
1661 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001662 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001663
1664config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001665 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001666 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001667 help
1668 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001669 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001670 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001671
Tejun Heo3b166512011-04-01 11:15:12 +02001672config ARCH_PROC_KCORE_TEXT
1673 def_bool y
1674 depends on X86_64 && PROC_KCORE
1675
Avi Kivitya29815a2010-01-10 16:28:09 +02001676config ILLEGAL_POINTER_VALUE
1677 hex
1678 default 0 if X86_32
1679 default 0xdead000000000000 if X86_64
1680
Dan Williams7a678322015-08-19 00:34:34 -04001681config X86_PMEM_LEGACY_DEVICE
1682 bool
1683
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001684config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001685 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001686 depends on PHYS_ADDR_T_64BIT
1687 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001688 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001689 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001690 help
1691 Treat memory marked using the non-standard e820 type of 12 as used
1692 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1693 The kernel will offer these regions to the 'pmem' driver so
1694 they can be used for persistent storage.
1695
1696 Say Y if unsure.
1697
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001698config HIGHPTE
1699 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001700 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001701 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001702 The VM uses one page table entry for each page of physical memory.
1703 For systems with a lot of RAM, this can be wasteful of precious
1704 low memory. Setting this option will put user-space page table
1705 entries in high memory.
1706
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001707config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001708 bool "Check for low memory corruption"
1709 ---help---
1710 Periodically check for memory corruption in low memory, which
1711 is suspected to be caused by BIOS. Even when enabled in the
1712 configuration, it is disabled at runtime. Enable it by
1713 setting "memory_corruption_check=1" on the kernel command
1714 line. By default it scans the low 64k of memory every 60
1715 seconds; see the memory_corruption_check_size and
1716 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001717 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001718
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001719 When enabled with the default parameters, this option has
1720 almost no overhead, as it reserves a relatively small amount
1721 of memory and scans it infrequently. It both detects corruption
1722 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001723
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001724 It is, however, intended as a diagnostic tool; if repeatable
1725 BIOS-originated corruption always affects the same memory,
1726 you can use memmap= to prevent the kernel from using that
1727 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001728
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001729config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001730 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001731 depends on X86_CHECK_BIOS_CORRUPTION
1732 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001733 ---help---
1734 Set whether the default state of memory_corruption_check is
1735 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001736
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001737config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001738 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1739 default 64
1740 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001741 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001742 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001743
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001744 The first page contains BIOS data structures that the kernel
1745 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001746
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001747 By default we reserve the first 64K of physical RAM, as a
1748 number of BIOSes are known to corrupt that memory range
1749 during events such as suspend/resume or monitor cable
1750 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001751
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001752 You can set this to 4 if you are absolutely sure that you
1753 trust the BIOS to get all its memory reservations and usages
1754 right. If you know your BIOS have problems beyond the
1755 default 64K area, you can set this to 640 to avoid using the
1756 entire low memory range.
1757
1758 If you have doubts about the BIOS (e.g. suspend/resume does
1759 not work or there's kernel crashes after certain hardware
1760 hotplug events) then you might want to enable
1761 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1762 typical corruption patterns.
1763
1764 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001765
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001766config MATH_EMULATION
1767 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001768 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001769 prompt "Math emulation" if X86_32
1770 ---help---
1771 Linux can emulate a math coprocessor (used for floating point
1772 operations) if you don't have one. 486DX and Pentium processors have
1773 a math coprocessor built in, 486SX and 386 do not, unless you added
1774 a 487DX or 387, respectively. (The messages during boot time can
1775 give you some hints here ["man dmesg"].) Everyone needs either a
1776 coprocessor or this emulation.
1777
1778 If you don't have a math coprocessor, you need to say Y here; if you
1779 say Y here even though you have a coprocessor, the coprocessor will
1780 be used nevertheless. (This behavior can be changed with the kernel
1781 command line option "no387", which comes handy if your coprocessor
1782 is broken. Try "man bootparam" or see the documentation of your boot
1783 loader (lilo or loadlin) about how to pass options to the kernel at
1784 boot time.) This means that it is a good idea to say Y here if you
1785 intend to use this kernel on different machines.
1786
1787 More information about the internals of the Linux math coprocessor
1788 emulation can be found in <file:arch/x86/math-emu/README>.
1789
1790 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1791 kernel, it won't hurt.
1792
1793config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001794 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001795 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001796 ---help---
1797 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1798 the Memory Type Range Registers (MTRRs) may be used to control
1799 processor access to memory ranges. This is most useful if you have
1800 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1801 allows bus write transfers to be combined into a larger transfer
1802 before bursting over the PCI/AGP bus. This can increase performance
1803 of image write operations 2.5 times or more. Saying Y here creates a
1804 /proc/mtrr file which may be used to manipulate your processor's
1805 MTRRs. Typically the X server should use this.
1806
1807 This code has a reasonably generic interface so that similar
1808 control registers on other processors can be easily supported
1809 as well:
1810
1811 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1812 Registers (ARRs) which provide a similar functionality to MTRRs. For
1813 these, the ARRs are used to emulate the MTRRs.
1814 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1815 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1816 write-combining. All of these processors are supported by this code
1817 and it makes sense to say Y here if you have one of them.
1818
1819 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1820 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1821 can lead to all sorts of problems, so it's good to say Y here.
1822
1823 You can safely say Y even if your machine doesn't have MTRRs, you'll
1824 just add about 9 KB to your kernel.
1825
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001826 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001827
Yinghai Lu95ffa242008-04-29 03:52:33 -07001828config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001829 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001830 prompt "MTRR cleanup support"
1831 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001832 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001833 Convert MTRR layout from continuous to discrete, so X drivers can
1834 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001835
Thomas Gleixneraba37282008-07-15 14:48:48 +02001836 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001837 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001838 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001839
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001840 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001841
1842config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001843 int "MTRR cleanup enable value (0-1)"
1844 range 0 1
1845 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001846 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001847 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001848 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001849
Yinghai Lu12031a62008-05-02 02:40:22 -07001850config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1851 int "MTRR cleanup spare reg num (0-7)"
1852 range 0 7
1853 default "1"
1854 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001855 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001856 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001857 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001858
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001859config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001860 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001861 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001862 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001863 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001864 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001865
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001866 PATs are the modern equivalents of MTRRs and are much more
1867 flexible than MTRRs.
1868
1869 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001870 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001871
1872 If unsure, say Y.
1873
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001874config ARCH_USES_PG_UNCACHED
1875 def_bool y
1876 depends on X86_PAT
1877
H. Peter Anvin628c6242011-07-31 13:59:29 -07001878config ARCH_RANDOM
1879 def_bool y
1880 prompt "x86 architectural random number generator" if EXPERT
1881 ---help---
1882 Enable the x86 architectural RDRAND instruction
1883 (Intel Bull Mountain technology) to generate random numbers.
1884 If supported, this is a high bandwidth, cryptographically
1885 secure hardware random number generator.
1886
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001887config X86_SMAP
1888 def_bool y
1889 prompt "Supervisor Mode Access Prevention" if EXPERT
1890 ---help---
1891 Supervisor Mode Access Prevention (SMAP) is a security
1892 feature in newer Intel processors. There is a small
1893 performance cost if this enabled and turned on; there is
1894 also a small increase in the kernel size if this is enabled.
1895
1896 If unsure, say Y.
1897
Ricardo Neriaa35f892017-11-05 18:27:54 -08001898config X86_INTEL_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001899 def_bool y
Ricardo Neriaa35f892017-11-05 18:27:54 -08001900 depends on CPU_SUP_INTEL
1901 prompt "Intel User Mode Instruction Prevention" if EXPERT
1902 ---help---
1903 The User Mode Instruction Prevention (UMIP) is a security
1904 feature in newer Intel processors. If enabled, a general
Ricardo Neri796ebc82017-11-13 22:29:42 -08001905 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1906 or STR instructions are executed in user mode. These instructions
1907 unnecessarily expose information about the hardware state.
1908
1909 The vast majority of applications do not use these instructions.
1910 For the very few that do, software emulation is provided in
1911 specific cases in protected and virtual-8086 modes. Emulated
1912 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001913
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001914config X86_INTEL_MPX
1915 prompt "Intel MPX (Memory Protection Extensions)"
1916 def_bool n
Rik van Rieldf3735c2017-09-06 16:25:11 -07001917 # Note: only available in 64-bit mode due to VMA flags shortage
1918 depends on CPU_SUP_INTEL && X86_64
1919 select ARCH_USES_HIGH_VMA_FLAGS
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001920 ---help---
1921 MPX provides hardware features that can be used in
1922 conjunction with compiler-instrumented code to check
1923 memory references. It is designed to detect buffer
1924 overflow or underflow bugs.
1925
1926 This option enables running applications which are
1927 instrumented or otherwise use MPX. It does not use MPX
1928 itself inside the kernel or to protect the kernel
1929 against bad memory references.
1930
1931 Enabling this option will make the kernel larger:
1932 ~8k of kernel text and 36 bytes of data on a 64-bit
1933 defconfig. It adds a long to the 'mm_struct' which
1934 will increase the kernel memory overhead of each
1935 process and adds some branches to paths used during
1936 exec() and munmap().
1937
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001938 For details, see Documentation/x86/intel_mpx.rst
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001939
1940 If unsure, say N.
1941
Dave Hansen35e97792016-02-12 13:02:00 -08001942config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001943 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001944 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001945 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001946 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001947 select ARCH_USES_HIGH_VMA_FLAGS
1948 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001949 ---help---
1950 Memory Protection Keys provides a mechanism for enforcing
1951 page-based protections, but without requiring modification of the
1952 page tables when an application changes protection domains.
1953
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001954 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001955
1956 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001957
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001958config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001959 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001960 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001961 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001962 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001963 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001964 This enables the kernel to use EFI runtime services that are
1965 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001966
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001967 This option is only useful on systems that have EFI firmware.
1968 In addition, you should use the latest ELILO loader available
1969 at <http://elilo.sourceforge.net> in order to take advantage
1970 of EFI runtime services. However, even with this option, the
1971 resultant kernel should continue to boot on existing non-EFI
1972 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001973
Matt Fleming291f3632011-12-12 21:27:52 +00001974config EFI_STUB
1975 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001976 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001977 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001978 ---help---
1979 This kernel feature allows a bzImage to be loaded directly
1980 by EFI firmware without the use of a bootloader.
1981
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001982 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001983
Matt Fleming7d453ee2014-01-10 18:52:06 +00001984config EFI_MIXED
1985 bool "EFI mixed-mode support"
1986 depends on EFI_STUB && X86_64
1987 ---help---
1988 Enabling this feature allows a 64-bit kernel to be booted
1989 on a 32-bit firmware, provided that your CPU supports 64-bit
1990 mode.
1991
1992 Note that it is not possible to boot a mixed-mode enabled
1993 kernel via the EFI boot stub - a bootloader that supports
1994 the EFI handover protocol must be used.
1995
1996 If unsure, say N.
1997
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001998config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001999 def_bool y
2000 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002001 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002002 This kernel feature is useful for number crunching applications
2003 that may need to compute untrusted bytecode during their
2004 execution. By using pipes or other transports made available to
2005 the process as file descriptors supporting the read/write
2006 syscalls, it's possible to isolate those applications in
2007 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04002008 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002009 and the task is only allowed to execute a few safe syscalls
2010 defined by each seccomp mode.
2011
2012 If unsure, say Y. Only embedded should say N here.
2013
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002014source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002015
2016config KEXEC
2017 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07002018 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002019 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002020 kexec is a system call that implements the ability to shutdown your
2021 current kernel, and to start another kernel. It is like a reboot
2022 but it is independent of the system firmware. And like a reboot
2023 you can start any kernel with it, not just Linux.
2024
2025 The name comes from the similarity to the exec system call.
2026
2027 It is an ongoing process to be certain the hardware in a machine
2028 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002029 initially work for you. As of this writing the exact hardware
2030 interface is strongly in flux, so no good recommendation can be
2031 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002032
Vivek Goyal74ca3172014-08-29 15:18:46 -07002033config KEXEC_FILE
2034 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002035 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002036 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002037 depends on X86_64
2038 depends on CRYPTO=y
2039 depends on CRYPTO_SHA256=y
2040 ---help---
2041 This is new version of kexec system call. This system call is
2042 file based and takes file descriptors as system call argument
2043 for kernel and initramfs as opposed to list of segments as
2044 accepted by previous system call.
2045
AKASHI Takahirob799a092018-04-13 15:35:45 -07002046config ARCH_HAS_KEXEC_PURGATORY
2047 def_bool KEXEC_FILE
2048
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002049config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002050 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002051 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002052 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002053
2054 This option makes the kexec_file_load() syscall check for a valid
2055 signature of the kernel image. The image can still be loaded without
2056 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2057 there's a signature that we can check, then it must be valid.
2058
2059 In addition to this option, you need to enable signature
2060 verification for the corresponding kernel image type being
2061 loaded in order for this to work.
2062
2063config KEXEC_SIG_FORCE
2064 bool "Require a valid signature in kexec_file_load() syscall"
2065 depends on KEXEC_SIG
2066 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002067 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002068 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002069
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002070config KEXEC_BZIMAGE_VERIFY_SIG
2071 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002072 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002073 depends on SIGNED_PE_FILE_VERIFICATION
2074 select SYSTEM_TRUSTED_KEYRING
2075 ---help---
2076 Enable bzImage signature verification support.
2077
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002078config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002079 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002080 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002081 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002082 Generate crash dump after being started by kexec.
2083 This should be normally only set in special crash dump kernels
2084 which are loaded in the main kernel with kexec-tools into
2085 a specially reserved region and then later executed after
2086 a crash by kdump/kexec. The crash dump kernel must be compiled
2087 to a memory address not used by the main kernel or BIOS using
2088 PHYSICAL_START, or it must be built as a relocatable image
2089 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002090 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002091
Huang Ying3ab83522008-07-25 19:45:07 -07002092config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002093 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002094 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002095 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002096 Jump between original kernel and kexeced kernel and invoke
2097 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002098
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002099config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002100 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002101 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002102 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002103 This gives the physical address where the kernel is loaded.
2104
2105 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2106 bzImage will decompress itself to above physical address and
2107 run from there. Otherwise, bzImage will run from the address where
2108 it has been loaded by the boot loader and will ignore above physical
2109 address.
2110
2111 In normal kdump cases one does not have to set/change this option
2112 as now bzImage can be compiled as a completely relocatable image
2113 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2114 address. This option is mainly useful for the folks who don't want
2115 to use a bzImage for capturing the crash dump and want to use a
2116 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2117 to be specifically compiled to run from a specific memory area
2118 (normally a reserved region) and this option comes handy.
2119
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002120 So if you are using bzImage for capturing the crash dump,
2121 leave the value here unchanged to 0x1000000 and set
2122 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2123 for capturing the crash dump change this value to start of
2124 the reserved region. In other words, it can be set based on
2125 the "X" value as specified in the "crashkernel=YM@XM"
2126 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002127 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002128 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002129
2130 Usage of bzImage for capturing the crash dump is recommended as
2131 one does not have to build two kernels. Same kernel can be used
2132 as production kernel and capture kernel. Above option should have
2133 gone away after relocatable bzImage support is introduced. But it
2134 is present because there are users out there who continue to use
2135 vmlinux for dump capture. This option should go away down the
2136 line.
2137
2138 Don't change this unless you know what you are doing.
2139
2140config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002141 bool "Build a relocatable kernel"
2142 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002143 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002144 This builds a kernel image that retains relocation information
2145 so it can be loaded someplace besides the default 1MB.
2146 The relocations tend to make the kernel binary about 10% larger,
2147 but are discarded at runtime.
2148
2149 One use is for the kexec on panic case where the recovery kernel
2150 must live at a different physical address than the primary
2151 kernel.
2152
2153 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2154 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002155 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002156
Kees Cook8ab38202013-10-10 17:18:14 -07002157config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002158 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002159 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002160 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002161 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002162 In support of Kernel Address Space Layout Randomization (KASLR),
2163 this randomizes the physical address at which the kernel image
2164 is decompressed and the virtual address where the kernel
2165 image is mapped, as a security feature that deters exploit
2166 attempts relying on knowledge of the location of kernel
2167 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002168
Kees Cooked9f0072016-05-25 15:45:33 -07002169 On 64-bit, the kernel physical and virtual addresses are
2170 randomized separately. The physical address will be anywhere
2171 between 16MB and the top of physical memory (up to 64TB). The
2172 virtual address will be randomized from 16MB up to 1GB (9 bits
2173 of entropy). Note that this also reduces the memory space
2174 available to kernel modules from 1.5GB to 1GB.
2175
2176 On 32-bit, the kernel physical and virtual addresses are
2177 randomized together. They will be randomized from 16MB up to
2178 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002179
Baoquan Hee8581e32016-04-20 13:55:43 -07002180 Entropy is generated using the RDRAND instruction if it is
2181 supported. If RDTSC is supported, its value is mixed into
2182 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002183 supported, then entropy is read from the i8254 timer. The
2184 usable entropy is limited by the kernel being built using
2185 2GB addressing, and that PHYSICAL_ALIGN must be at a
2186 minimum of 2MB. As a result, only 10 bits of entropy are
2187 theoretically possible, but the implementations are further
2188 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002189
Ingo Molnar6807c842017-04-18 11:08:12 +02002190 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002191
2192# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002193config X86_NEED_RELOCS
2194 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002195 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002196
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002197config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002198 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002199 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002200 range 0x2000 0x1000000 if X86_32
2201 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002202 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002203 This value puts the alignment restrictions on physical address
2204 where kernel is loaded and run from. Kernel is compiled for an
2205 address which meets above alignment restriction.
2206
2207 If bootloader loads the kernel at a non-aligned address and
2208 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2209 address aligned to above value and run from there.
2210
2211 If bootloader loads the kernel at a non-aligned address and
2212 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2213 load address and decompress itself to the address it has been
2214 compiled for and run from there. The address for which kernel is
2215 compiled already meets above alignment restrictions. Hence the
2216 end result is that kernel runs from a physical address meeting
2217 above alignment restrictions.
2218
Kees Cooka0215062013-07-08 09:15:17 -07002219 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2220 this value must be a multiple of 0x200000.
2221
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002222 Don't change this unless you know what you are doing.
2223
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002224config DYNAMIC_MEMORY_LAYOUT
2225 bool
2226 ---help---
2227 This option makes base addresses of vmalloc and vmemmap as well as
2228 __PAGE_OFFSET movable during boot.
2229
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002230config RANDOMIZE_MEMORY
2231 bool "Randomize the kernel memory sections"
2232 depends on X86_64
2233 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002234 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002235 default RANDOMIZE_BASE
2236 ---help---
2237 Randomizes the base virtual address of kernel memory sections
2238 (physical memory mapping, vmalloc & vmemmap). This security feature
2239 makes exploits relying on predictable memory locations less reliable.
2240
2241 The order of allocations remains unchanged. Entropy is generated in
2242 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2243 configuration have in average 30,000 different possible virtual
2244 addresses for each memory section.
2245
Ingo Molnar6807c842017-04-18 11:08:12 +02002246 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002247
Thomas Garnier90397a42016-06-21 17:47:06 -07002248config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2249 hex "Physical memory mapping padding" if EXPERT
2250 depends on RANDOMIZE_MEMORY
2251 default "0xa" if MEMORY_HOTPLUG
2252 default "0x0"
2253 range 0x1 0x40 if MEMORY_HOTPLUG
2254 range 0x0 0x40
2255 ---help---
2256 Define the padding in terabytes added to the existing physical
2257 memory size during kernel memory randomization. It is useful
2258 for memory hotplug support but reduces the entropy available for
2259 address randomization.
2260
2261 If unsure, leave at the default value.
2262
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002263config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002264 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002265 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002266
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002267config BOOTPARAM_HOTPLUG_CPU0
2268 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002269 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002270 ---help---
2271 Set whether default state of cpu0_hotpluggable is on or off.
2272
2273 Say Y here to enable CPU0 hotplug by default. If this switch
2274 is turned on, there is no need to give cpu0_hotplug kernel
2275 parameter and the CPU0 hotplug feature is enabled by default.
2276
2277 Please note: there are two known CPU0 dependencies if you want
2278 to enable the CPU0 hotplug feature either by this switch or by
2279 cpu0_hotplug kernel parameter.
2280
2281 First, resume from hibernate or suspend always starts from CPU0.
2282 So hibernate and suspend are prevented if CPU0 is offline.
2283
2284 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2285 offline if any interrupt can not migrate out of CPU0. There may
2286 be other CPU0 dependencies.
2287
2288 Please make sure the dependencies are under your control before
2289 you enable this feature.
2290
2291 Say N if you don't want to enable CPU0 hotplug feature by default.
2292 You still can enable the CPU0 hotplug feature at boot by kernel
2293 parameter cpu0_hotplug.
2294
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002295config DEBUG_HOTPLUG_CPU0
2296 def_bool n
2297 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002298 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002299 ---help---
2300 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2301 soon as possible and boots up userspace with CPU0 offlined. User
2302 can online CPU0 back after boot time.
2303
2304 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2305 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2306 compilation or giving cpu0_hotplug kernel parameter at boot.
2307
2308 If unsure, say N.
2309
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002310config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002311 def_bool n
2312 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002313 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002314 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002315 Certain buggy versions of glibc will crash if they are
2316 presented with a 32-bit vDSO that is not mapped at the address
2317 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002318
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002319 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2320 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2321 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2322 the only released version with the bug, but OpenSUSE 9
2323 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002324
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002325 The symptom of the bug is that everything crashes on startup, saying:
2326 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2327
2328 Saying Y here changes the default value of the vdso32 boot
2329 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2330 This works around the glibc bug but hurts performance.
2331
2332 If unsure, say N: if you are compiling your own kernel, you
2333 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002334
Kees Cook3dc33bd2015-08-12 17:55:19 -07002335choice
2336 prompt "vsyscall table for legacy applications"
2337 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002338 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002339 help
2340 Legacy user code that does not know how to find the vDSO expects
2341 to be able to issue three syscalls by calling fixed addresses in
2342 kernel space. Since this location is not randomized with ASLR,
2343 it can be used to assist security vulnerability exploitation.
2344
2345 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002346 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002347
2348 On a system with recent enough glibc (2.14 or newer) and no
2349 static binaries, you can say None without a performance penalty
2350 to improve security.
2351
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002352 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002353
Kees Cook3dc33bd2015-08-12 17:55:19 -07002354 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002355 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002356 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002357 The kernel traps and emulates calls into the fixed vsyscall
2358 address mapping. This makes the mapping non-executable, but
2359 it still contains readable known contents, which could be
2360 used in certain rare security vulnerability exploits. This
2361 configuration is recommended when using legacy userspace
2362 that still uses vsyscalls along with legacy binary
2363 instrumentation tools that require code to be readable.
2364
2365 An example of this type of legacy userspace is running
2366 Pin on an old binary that still uses vsyscalls.
2367
2368 config LEGACY_VSYSCALL_XONLY
2369 bool "Emulate execution only"
2370 help
2371 The kernel traps and emulates calls into the fixed vsyscall
2372 address mapping and does not allow reads. This
2373 configuration is recommended when userspace might use the
2374 legacy vsyscall area but support for legacy binary
2375 instrumentation of legacy code is not needed. It mitigates
2376 certain uses of the vsyscall area as an ASLR-bypassing
2377 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002378
2379 config LEGACY_VSYSCALL_NONE
2380 bool "None"
2381 help
2382 There will be no vsyscall mapping at all. This will
2383 eliminate any risk of ASLR bypass due to the vsyscall
2384 fixed address mapping. Attempts to use the vsyscalls
2385 will be reported to dmesg, so that either old or
2386 malicious userspace programs can be identified.
2387
2388endchoice
2389
Tim Bird516cbf32008-08-12 12:52:36 -07002390config CMDLINE_BOOL
2391 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002392 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002393 Allow for specifying boot arguments to the kernel at
2394 build time. On some systems (e.g. embedded ones), it is
2395 necessary or convenient to provide some or all of the
2396 kernel boot arguments with the kernel itself (that is,
2397 to not rely on the boot loader to provide them.)
2398
2399 To compile command line arguments into the kernel,
2400 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002401 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002402
2403 Systems with fully functional boot loaders (i.e. non-embedded)
2404 should leave this option set to 'N'.
2405
2406config CMDLINE
2407 string "Built-in kernel command string"
2408 depends on CMDLINE_BOOL
2409 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002410 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002411 Enter arguments here that should be compiled into the kernel
2412 image and used at boot time. If the boot loader provides a
2413 command line at boot time, it is appended to this string to
2414 form the full kernel command line, when the system boots.
2415
2416 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2417 change this behavior.
2418
2419 In most cases, the command line (whether built-in or provided
2420 by the boot loader) should specify the device for the root
2421 file system.
2422
2423config CMDLINE_OVERRIDE
2424 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002425 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002426 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002427 Set this option to 'Y' to have the kernel ignore the boot loader
2428 command line, and use ONLY the built-in command line.
2429
2430 This is used to work around broken boot loaders. This should
2431 be set to 'N' under normal conditions.
2432
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002433config MODIFY_LDT_SYSCALL
2434 bool "Enable the LDT (local descriptor table)" if EXPERT
2435 default y
2436 ---help---
2437 Linux can allow user programs to install a per-process x86
2438 Local Descriptor Table (LDT) using the modify_ldt(2) system
2439 call. This is required to run 16-bit or segmented code such as
2440 DOSEMU or some Wine programs. It is also used by some very old
2441 threading libraries.
2442
2443 Enabling this feature adds a small amount of overhead to
2444 context switches and increases the low-level kernel attack
2445 surface. Disabling it removes the modify_ldt(2) system call.
2446
2447 Saying 'N' here may make sense for embedded or server kernels.
2448
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002449source "kernel/livepatch/Kconfig"
2450
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002451endmenu
2452
Michal Hocko3072e412017-09-08 16:11:39 -07002453config ARCH_HAS_ADD_PAGES
2454 def_bool y
2455 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2456
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002457config ARCH_ENABLE_MEMORY_HOTPLUG
2458 def_bool y
2459 depends on X86_64 || (X86_32 && HIGHMEM)
2460
Gary Hade35551052008-10-31 10:52:03 -07002461config ARCH_ENABLE_MEMORY_HOTREMOVE
2462 def_bool y
2463 depends on MEMORY_HOTPLUG
2464
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002465config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002466 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002467 depends on NUMA
2468
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002469config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2470 def_bool y
2471 depends on X86_64 || X86_PAE
2472
Naoya Horiguchic177c812014-06-04 16:05:35 -07002473config ARCH_ENABLE_HUGEPAGE_MIGRATION
2474 def_bool y
2475 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2476
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002477config ARCH_ENABLE_THP_MIGRATION
2478 def_bool y
2479 depends on X86_64 && TRANSPARENT_HUGEPAGE
2480
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002481menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002482
2483config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002484 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002485 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002486
2487source "kernel/power/Kconfig"
2488
2489source "drivers/acpi/Kconfig"
2490
Feng Tangefafc8b2009-08-14 15:23:29 -04002491source "drivers/sfi/Kconfig"
2492
Andi Kleena6b68072008-01-30 13:32:49 +01002493config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002494 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002495 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002496
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002497menuconfig APM
2498 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002499 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002500 ---help---
2501 APM is a BIOS specification for saving power using several different
2502 techniques. This is mostly useful for battery powered laptops with
2503 APM compliant BIOSes. If you say Y here, the system time will be
2504 reset after a RESUME operation, the /proc/apm device will provide
2505 battery status information, and user-space programs will receive
2506 notification of APM "events" (e.g. battery status change).
2507
2508 If you select "Y" here, you can disable actual use of the APM
2509 BIOS by passing the "apm=off" option to the kernel at boot time.
2510
2511 Note that the APM support is almost completely disabled for
2512 machines with more than one CPU.
2513
2514 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002515 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002516 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002517 <http://www.tldp.org/docs.html#howto>.
2518
2519 This driver does not spin down disk drives (see the hdparm(8)
2520 manpage ("man 8 hdparm") for that), and it doesn't turn off
2521 VESA-compliant "green" monitors.
2522
2523 This driver does not support the TI 4000M TravelMate and the ACER
2524 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2525 desktop machines also don't have compliant BIOSes, and this driver
2526 may cause those machines to panic during the boot phase.
2527
2528 Generally, if you don't have a battery in your machine, there isn't
2529 much point in using this driver and you should say N. If you get
2530 random kernel OOPSes or reboots that don't seem to be related to
2531 anything, try disabling/enabling this option (or disabling/enabling
2532 APM in your BIOS).
2533
2534 Some other things you should try when experiencing seemingly random,
2535 "weird" problems:
2536
2537 1) make sure that you have enough swap space and that it is
2538 enabled.
2539 2) pass the "no-hlt" option to the kernel
2540 3) switch on floating point emulation in the kernel and pass
2541 the "no387" option to the kernel
2542 4) pass the "floppy=nodma" option to the kernel
2543 5) pass the "mem=4M" option to the kernel (thereby disabling
2544 all but the first 4 MB of RAM)
2545 6) make sure that the CPU is not over clocked.
2546 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2547 8) disable the cache from your BIOS settings
2548 9) install a fan for the video card or exchange video RAM
2549 10) install a better fan for the CPU
2550 11) exchange RAM chips
2551 12) exchange the motherboard.
2552
2553 To compile this driver as a module, choose M here: the
2554 module will be called apm.
2555
2556if APM
2557
2558config APM_IGNORE_USER_SUSPEND
2559 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002560 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002561 This option will ignore USER SUSPEND requests. On machines with a
2562 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2563 series notebooks, it is necessary to say Y because of a BIOS bug.
2564
2565config APM_DO_ENABLE
2566 bool "Enable PM at boot time"
2567 ---help---
2568 Enable APM features at boot time. From page 36 of the APM BIOS
2569 specification: "When disabled, the APM BIOS does not automatically
2570 power manage devices, enter the Standby State, enter the Suspend
2571 State, or take power saving steps in response to CPU Idle calls."
2572 This driver will make CPU Idle calls when Linux is idle (unless this
2573 feature is turned off -- see "Do CPU IDLE calls", below). This
2574 should always save battery power, but more complicated APM features
2575 will be dependent on your BIOS implementation. You may need to turn
2576 this option off if your computer hangs at boot time when using APM
2577 support, or if it beeps continuously instead of suspending. Turn
2578 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2579 T400CDT. This is off by default since most machines do fine without
2580 this feature.
2581
2582config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002583 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002584 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002585 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002586 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2587 On some machines, this can activate improved power savings, such as
2588 a slowed CPU clock rate, when the machine is idle. These idle calls
2589 are made after the idle loop has run for some length of time (e.g.,
2590 333 mS). On some machines, this will cause a hang at boot time or
2591 whenever the CPU becomes idle. (On machines with more than one CPU,
2592 this option does nothing.)
2593
2594config APM_DISPLAY_BLANK
2595 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002596 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002597 Enable console blanking using the APM. Some laptops can use this to
2598 turn off the LCD backlight when the screen blanker of the Linux
2599 virtual console blanks the screen. Note that this is only used by
2600 the virtual console screen blanker, and won't turn off the backlight
2601 when using the X Window system. This also doesn't have anything to
2602 do with your VESA-compliant power-saving monitor. Further, this
2603 option doesn't work for all laptops -- it might not turn off your
2604 backlight at all, or it might print a lot of errors to the console,
2605 especially if you are using gpm.
2606
2607config APM_ALLOW_INTS
2608 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002609 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002610 Normally we disable external interrupts while we are making calls to
2611 the APM BIOS as a measure to lessen the effects of a badly behaving
2612 BIOS implementation. The BIOS should reenable interrupts if it
2613 needs to. Unfortunately, some BIOSes do not -- especially those in
2614 many of the newer IBM Thinkpads. If you experience hangs when you
2615 suspend, try setting this to Y. Otherwise, say N.
2616
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002617endif # APM
2618
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002619source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002620
2621source "drivers/cpuidle/Kconfig"
2622
Andy Henroid27471fd2008-10-09 11:45:22 -07002623source "drivers/idle/Kconfig"
2624
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002625endmenu
2626
2627
2628menu "Bus options (PCI etc.)"
2629
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002630choice
2631 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002632 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002633 default PCI_GOANY
2634 ---help---
2635 On PCI systems, the BIOS can be used to detect the PCI devices and
2636 determine their configuration. However, some old PCI motherboards
2637 have BIOS bugs and may crash if this is done. Also, some embedded
2638 PCI-based systems don't have any BIOS at all. Linux can also try to
2639 detect the PCI hardware directly without using the BIOS.
2640
2641 With this option, you can specify how Linux should detect the
2642 PCI devices. If you choose "BIOS", the BIOS will be used,
2643 if you choose "Direct", the BIOS won't be used, and if you
2644 choose "MMConfig", then PCI Express MMCONFIG will be used.
2645 If you choose "Any", the kernel will try MMCONFIG, then the
2646 direct access method and falls back to the BIOS if that doesn't
2647 work. If unsure, go with the default, which is "Any".
2648
2649config PCI_GOBIOS
2650 bool "BIOS"
2651
2652config PCI_GOMMCONFIG
2653 bool "MMConfig"
2654
2655config PCI_GODIRECT
2656 bool "Direct"
2657
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002658config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002659 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002660 depends on OLPC
2661
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002662config PCI_GOANY
2663 bool "Any"
2664
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002665endchoice
2666
2667config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002668 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002669 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002670
2671# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2672config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002673 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002674 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002675
2676config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002677 bool "Support mmconfig PCI config space access" if X86_64
2678 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002679 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002680 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002681
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002682config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002683 def_bool y
2684 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002685
Alex Nixonb5401a92010-03-18 16:31:34 -04002686config PCI_XEN
2687 def_bool y
2688 depends on PCI && XEN
2689 select SWIOTLB_XEN
2690
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002691config MMCONF_FAM10H
2692 def_bool y
2693 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002694
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002695config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002696 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002697 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002698 help
2699 Read the PCI windows out of the CNB20LE host bridge. This allows
2700 PCI hotplug to work on systems with the CNB20LE chipset which do
2701 not have ACPI.
2702
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002703 There's no public spec for this chipset, and this functionality
2704 is known to be incomplete.
2705
2706 You should say N unless you know you need this.
2707
William Breathitt Gray3a495512016-05-27 18:08:27 -04002708config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002709 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002710 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002711 Expose ISA bus device drivers and options available for selection and
2712 configuration. Enable this option if your target machine has an ISA
2713 bus. ISA is an older system, displaced by PCI and newer bus
2714 architectures -- if your target machine is modern, it probably does
2715 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002716
2717 If unsure, say N.
2718
David Rientjes1c00f012011-03-22 16:34:59 -07002719# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002720config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002721 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2722 default y
2723 help
2724 Enables ISA-style DMA support for devices requiring such controllers.
2725 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726
Linus Torvalds51e68d02016-05-21 10:25:19 -07002727if X86_32
2728
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002729config ISA
2730 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002731 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002732 Find out whether you have ISA slots on your motherboard. ISA is the
2733 name of a bus system, i.e. the way the CPU talks to the other stuff
2734 inside your box. Other bus systems are PCI, EISA, MicroChannel
2735 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2736 newer boards don't support it. If you have ISA, say Y, otherwise N.
2737
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002738config SCx200
2739 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002740 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002741 This provides basic support for National Semiconductor's
2742 (now AMD's) Geode processors. The driver probes for the
2743 PCI-IDs of several on-chip devices, so its a good dependency
2744 for other scx200_* drivers.
2745
2746 If compiled as a module, the driver is named scx200.
2747
2748config SCx200HR_TIMER
2749 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002750 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002751 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002752 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002753 This driver provides a clocksource built upon the on-chip
2754 27MHz high-resolution timer. Its also a workaround for
2755 NSC Geode SC-1100's buggy TSC, which loses time when the
2756 processor goes idle (as is done by the scheduler). The
2757 other workaround is idle=poll boot option.
2758
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002759config OLPC
2760 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002761 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002762 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002763 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002764 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002765 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002766 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002767 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002768 Add support for detecting the unique features of the OLPC
2769 XO hardware.
2770
Daniel Drakea3128582011-06-25 17:34:10 +01002771config OLPC_XO1_PM
2772 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002773 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002774 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002775 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002776
Daniel Drakecfee9592011-06-25 17:34:17 +01002777config OLPC_XO1_RTC
2778 bool "OLPC XO-1 Real Time Clock"
2779 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2780 ---help---
2781 Add support for the XO-1 real time clock, which can be used as a
2782 programmable wakeup source.
2783
Daniel Drake7feda8e2011-06-25 17:34:12 +01002784config OLPC_XO1_SCI
2785 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002786 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002787 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002788 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002789 ---help---
2790 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002791 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002792 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002793 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002794 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002795 - AC adapter status updates
2796 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002797
Daniel Drakea0f30f52011-06-25 17:34:18 +01002798config OLPC_XO15_SCI
2799 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002800 depends on OLPC && ACPI
2801 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002802 ---help---
2803 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2804 - EC-driven system wakeups
2805 - AC adapter status updates
2806 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002807
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002808config ALIX
2809 bool "PCEngines ALIX System Support (LED setup)"
2810 select GPIOLIB
2811 ---help---
2812 This option enables system support for the PCEngines ALIX.
2813 At present this just sets up LEDs for GPIO control on
2814 ALIX2/3/6 boards. However, other system specific setup should
2815 get added here.
2816
2817 Note: You must still enable the drivers for GPIO and LED support
2818 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2819
2820 Note: You have to set alix.force=1 for boards with Award BIOS.
2821
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002822config NET5501
2823 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2824 select GPIOLIB
2825 ---help---
2826 This option enables system support for the Soekris Engineering net5501.
2827
Philip A. Prindeville31970592012-01-14 01:45:39 -07002828config GEOS
2829 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2830 select GPIOLIB
2831 depends on DMI
2832 ---help---
2833 This option enables system support for the Traverse Technologies GEOS.
2834
Vivien Didelot7d029122013-01-04 16:18:14 -05002835config TS5500
2836 bool "Technologic Systems TS-5500 platform support"
2837 depends on MELAN
2838 select CHECK_SIGNATURE
2839 select NEW_LEDS
2840 select LEDS_CLASS
2841 ---help---
2842 This option enables system support for the Technologic Systems TS-5500.
2843
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002844endif # X86_32
2845
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002846config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002847 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002848 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002849
David Herrmanne3263ab2013-08-02 14:05:22 +02002850config X86_SYSFB
2851 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2852 help
2853 Firmwares often provide initial graphics framebuffers so the BIOS,
2854 bootloader or kernel can show basic video-output during boot for
2855 user-guidance and debugging. Historically, x86 used the VESA BIOS
2856 Extensions and EFI-framebuffers for this, which are mostly limited
2857 to x86.
2858 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2859 framebuffers so the new generic system-framebuffer drivers can be
2860 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002861 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002862 drivers like efifb, vesafb and uvesafb can pick it up.
2863 If this option is not selected, all system framebuffers are always
2864 marked as fallback platform framebuffers as usual.
2865
2866 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2867 not be able to pick up generic system framebuffers if this option
2868 is selected. You are highly encouraged to enable simplefb as
2869 replacement if you select this option. simplefb can correctly deal
2870 with generic system framebuffers. But you should still keep vesafb
2871 and others enabled as fallback if a system framebuffer is
2872 incompatible with simplefb.
2873
2874 If unsure, say Y.
2875
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002876endmenu
2877
2878
Christoph Hellwig15724972018-07-31 13:39:30 +02002879menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002880
2881config IA32_EMULATION
2882 bool "IA32 Emulation"
2883 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002884 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002885 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002886 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002887 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002888 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002889 Include code to run legacy 32-bit programs under a
2890 64-bit kernel. You should likely turn this on, unless you're
2891 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002892
2893config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002894 tristate "IA32 a.out support"
2895 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002896 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002897 ---help---
2898 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002899
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002900config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002901 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002902 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002903 ---help---
2904 Include code to run binaries for the x32 native 32-bit ABI
2905 for 64-bit processors. An x32 process gets access to the
2906 full 64-bit register file and wide data path while leaving
2907 pointers at 32 bits for smaller memory footprint.
2908
2909 You will need a recent binutils (2.22 or later) with
2910 elf32_x86_64 support enabled to compile a kernel with this
2911 option set.
2912
Ingo Molnar953fee12016-11-15 10:22:52 +01002913config COMPAT_32
2914 def_bool y
2915 depends on IA32_EMULATION || X86_32
2916 select HAVE_UID16
2917 select OLD_SIGSUSPEND3
2918
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002919config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002920 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002921 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002922
Jan Beulich3120e252012-09-10 12:41:45 +01002923if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002924config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002925 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002926
2927config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002928 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002929 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002930endif
David Howellsee009e4a02011-03-07 15:06:20 +00002931
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002932endmenu
2933
2934
Keith Packarde5beae12008-11-03 18:21:45 +01002935config HAVE_ATOMIC_IOMAP
2936 def_bool y
2937 depends on X86_32
2938
Alessandro Rubini4692d772012-04-04 19:39:58 +02002939config X86_DEV_DMA_OPS
2940 bool
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002941
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002942source "drivers/firmware/Kconfig"
2943
Avi Kivityedf88412007-12-16 11:02:48 +02002944source "arch/x86/kvm/Kconfig"