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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
Ard Biesheuvelc12d3362019-11-08 13:22:27 +010027 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
Ingo Molnard94e0682016-11-15 10:11:57 +010028 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
Dan Williams0aed55a2017-05-29 12:22:50 -070076 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070077 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010078 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070079 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080080 select ARCH_HAS_STRICT_KERNEL_RWX
81 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050082 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Andrey Ryabininc6d30852016-01-20 15:00:55 -080083 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020084 select ARCH_HAVE_NMI_SAFE_CMPXCHG
85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040086 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080087 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020088 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020089 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
92 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020093 select ARCH_USE_QUEUED_RWLOCKS
94 select ARCH_USE_QUEUED_SPINLOCKS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070095 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Ingo Molnarc763ea22016-11-15 10:26:39 +010096 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -070097 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -070098 select ARCH_WANTS_THP_SWAP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020099 select BUILDTIME_EXTABLE_SORT
100 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200101 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
102 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200103 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700104 select EDAC_ATOMIC_SCRUB
105 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select GENERIC_CLOCKEVENTS
107 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
108 select GENERIC_CLOCKEVENTS_MIN_ADJUST
109 select GENERIC_CMOS_UPDATE
110 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100111 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200112 select GENERIC_EARLY_IOREMAP
113 select GENERIC_FIND_FIRST_BIT
114 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200115 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200116 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200117 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200118 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200119 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200120 select GENERIC_IRQ_SHOW
121 select GENERIC_PENDING_IRQ if SMP
122 select GENERIC_SMP_IDLE_THREAD
123 select GENERIC_STRNCPY_FROM_USER
124 select GENERIC_STRNLEN_USER
125 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100126 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000127 select GENERIC_VDSO_TIME_NS
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
Daniel Axtens0609ae02019-11-30 17:55:00 -0800138 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200139 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800140 select HAVE_ARCH_MMAP_RND_BITS if MMU
141 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300142 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700143 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700145 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300146 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200147 select HAVE_ARCH_TRACEHOOK
148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800149 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700150 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100151 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900152 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200153 select HAVE_CMPXCHG_DOUBLE
154 select HAVE_CMPXCHG_LOCAL
155 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700156 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200157 select HAVE_C_RECORDMCOUNT
158 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700159 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400160 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900161 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500162 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800163 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700164 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100165 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700166 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700167 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400168 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200169 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200170 select HAVE_FUNCTION_GRAPH_TRACER
171 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200172 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530173 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200174 select HAVE_IDE
175 select HAVE_IOREMAP_PROT
176 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
177 select HAVE_IRQ_TIME_ACCOUNTING
178 select HAVE_KERNEL_BZIP2
179 select HAVE_KERNEL_GZIP
180 select HAVE_KERNEL_LZ4
181 select HAVE_KERNEL_LZMA
182 select HAVE_KERNEL_LZO
183 select HAVE_KERNEL_XZ
184 select HAVE_KPROBES
185 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900186 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200187 select HAVE_KRETPROBES
188 select HAVE_KVM
189 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200190 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200191 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500192 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800193 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700194 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200195 select HAVE_OPROFILE
196 select HAVE_OPTPROBES
197 select HAVE_PCSPKR_PLATFORM
198 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200199 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700200 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100201 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200202 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200203 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstra48a8b972018-08-22 17:30:16 +0200204 select HAVE_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200205 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200206 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900207 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900208 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100209 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400210 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200211 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200212 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300213 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100214 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200215 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100216 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200217 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100218 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000219 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200220 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500221 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200222 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200223 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500224 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200225 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700226 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select USER_STACKTRACE_SUPPORT
228 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200229 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800230 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530231
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200232config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100233 def_bool y
234 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200235
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700236config OUTPUT_FORMAT
237 string
238 default "elf32-i386" if X86_32
239 default "elf64-x86-64" if X86_64
240
Sam Ravnborg73531902008-05-25 23:03:18 +0200241config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200242 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200243 default "arch/x86/configs/i386_defconfig" if X86_32
244 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200245
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100246config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100247 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100248
249config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100250 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100251
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100252config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100253 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100254
Daniel Cashman9e08f572016-01-14 15:20:06 -0800255config ARCH_MMAP_RND_BITS_MIN
256 default 28 if 64BIT
257 default 8
258
259config ARCH_MMAP_RND_BITS_MAX
260 default 32 if 64BIT
261 default 16
262
263config ARCH_MMAP_RND_COMPAT_BITS_MIN
264 default 8
265
266config ARCH_MMAP_RND_COMPAT_BITS_MAX
267 default 16
268
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100269config SBUS
270 bool
271
272config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100273 def_bool y
274 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100275
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100276config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100277 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100278 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000279 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
280
281config GENERIC_BUG_RELATIVE_POINTERS
282 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100283
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100284config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100285 def_bool y
286 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100287
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100288config GENERIC_CALIBRATE_DELAY
289 def_bool y
290
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800291config ARCH_HAS_CPU_RELAX
292 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100293
Pekka Enberg1b27d052008-04-28 02:12:22 -0700294config ARCH_HAS_CACHE_LINE_SIZE
295 def_bool y
296
Dave Hansen316d0972018-04-20 15:20:28 -0700297config ARCH_HAS_FILTER_PGPROT
298 def_bool y
299
Mike Travisdd5af902008-01-30 13:33:32 +0100300config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900301 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100302
Tejun Heo08fc4582009-08-14 15:00:49 +0900303config NEED_PER_CPU_EMBED_FIRST_CHUNK
304 def_bool y
305
306config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900307 def_bool y
308
Johannes Berg801e4062007-12-08 02:12:39 +0100309config ARCH_HIBERNATION_POSSIBLE
310 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100311
Johannes Bergf4cb5702007-12-08 02:14:00 +0100312config ARCH_SUSPEND_POSSIBLE
313 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100314
Steve Capper53313b22013-04-30 08:03:42 +0100315config ARCH_WANT_GENERAL_HUGETLB
316 def_bool y
317
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100318config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000319 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100320
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000322 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100323
Akinobu Mita6a11f752009-03-31 15:23:17 -0700324config ARCH_SUPPORTS_DEBUG_PAGEALLOC
325 def_bool y
326
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300327config KASAN_SHADOW_OFFSET
328 hex
329 depends on KASAN
330 default 0xdffffc0000000000
331
Shane Wang69575d32009-09-01 18:25:07 -0700332config HAVE_INTEL_TXT
333 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700334 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700335
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100336config X86_32_SMP
337 def_bool y
338 depends on X86_32 && SMP
339
340config X86_64_SMP
341 def_bool y
342 depends on X86_64 && SMP
343
Tejun Heoccbeed32009-02-09 22:17:40 +0900344config X86_32_LAZY_GS
345 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900346 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900347
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530348config ARCH_SUPPORTS_UPROBES
349 def_bool y
350
Rob Herringd20642f2014-04-18 17:19:54 -0500351config FIX_EARLYCON_MEM
352 def_bool y
353
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300354config DYNAMIC_PHYSICAL_MASK
355 bool
356
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700357config PGTABLE_LEVELS
358 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300359 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700360 default 4 if X86_64
361 default 3 if X86_PAE
362 default 2
363
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900364config CC_HAS_SANE_STACKPROTECTOR
365 bool
366 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
367 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
368 help
369 We have to make sure stack protector is unconditionally disabled if
370 the compiler produces broken code.
371
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100372menu "Processor type and features"
373
Randy Dunlap5ee71532012-01-16 11:57:18 -0800374config ZONE_DMA
375 bool "DMA memory allocation support" if EXPERT
376 default y
377 help
378 DMA memory allocation support allows devices with less than 32-bit
379 addressing to allocate within the first 16MB of address space.
380 Disable if no such devices will be used.
381
382 If unsure, say Y.
383
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100384config SMP
385 bool "Symmetric multi-processing support"
386 ---help---
387 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800388 a system with only one CPU, say N. If you have a system with more
389 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100390
Robert Graffham4a474152014-01-23 15:55:29 -0800391 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100392 machines, but will use only one CPU of a multiprocessor machine. If
393 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800394 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100395 will run faster if you say N here.
396
397 Note that if you say Y here and choose architecture "586" or
398 "Pentium" under "Processor family", the kernel will not work on 486
399 architectures. Similarly, multiprocessor kernels for the "PPro"
400 architecture may not work on all Pentium based boards.
401
402 People using multiprocessor machines who say Y here should also say
403 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
404 Management" code will be disabled if you say Y here.
405
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300406 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300407 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100408 <http://www.tldp.org/docs.html#howto>.
409
410 If you don't know what to do here, say N.
411
Josh Triplett9def39be2013-10-30 08:09:45 -0700412config X86_FEATURE_NAMES
413 bool "Processor feature human-readable names" if EMBEDDED
414 default y
415 ---help---
416 This option compiles in a table of x86 feature bits and corresponding
417 names. This is required to support /proc/cpuinfo and a few kernel
418 messages. You can disable this to save space, at the expense of
419 making those few kernel messages show numeric feature bits instead.
420
421 If in doubt, say Y.
422
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800423config X86_X2APIC
424 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200425 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800426 ---help---
427 This enables x2apic support on CPUs that have this feature.
428
429 This allows 32-bit apic IDs (so it can support very large systems),
430 and accesses the local apic via MSRs not via mmio.
431
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800432 If you don't know what to do here, say N.
433
Yinghai Lu6695c852008-06-19 12:13:09 -0700434config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700435 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000436 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200437 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100438 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700439 For old smp systems that do not have proper acpi support. Newer systems
440 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700441
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000442config GOLDFISH
443 def_bool y
444 depends on X86_GOLDFISH
445
David Woodhouse76b04382018-01-11 21:46:25 +0000446config RETPOLINE
447 bool "Avoid speculative indirect branches in kernel"
448 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100449 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000450 help
451 Compile kernel with the retpoline compiler options to guard against
452 kernel-to-user data leaks by avoiding speculative indirect
453 branches. Requires a compiler with -mindirect-branch=thunk-extern
454 support for full protection. The kernel may run slower.
455
Johannes Weinere6d42932019-01-29 17:44:36 -0500456config X86_CPU_RESCTRL
457 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000458 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100459 select KERNFS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700460 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500461 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000462
463 Provide support for the allocation and monitoring of system resources
464 usage by the CPU.
465
466 Intel calls this Intel Resource Director Technology
467 (Intel(R) RDT). More information about RDT can be found in the
468 Intel x86 Architecture Software Developer Manual.
469
470 AMD calls this AMD Platform Quality of Service (AMD QoS).
471 More information about AMD QoS can be found in the AMD64 Technology
472 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700473
474 Say N if unsure.
475
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800476if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800477config X86_BIGSMP
478 bool "Support for big SMP systems with more than 8 CPUs"
479 depends on SMP
480 ---help---
481 This option is needed for the systems that have more than 8 CPUs
482
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800483config X86_EXTENDED_PLATFORM
484 bool "Support for extended (non-PC) x86 platforms"
485 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100486 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100487 If you disable this option then the kernel will only support
488 standard PC platforms. (which covers the vast majority of
489 systems out there.)
490
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800491 If you enable this option then you'll be able to select support
492 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100493 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800494 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800495 RDC R-321x SoC
496 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200497 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200498 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100499
500 If you have one of these systems, or if you want to build a
501 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800502endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100503
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800504if X86_64
505config X86_EXTENDED_PLATFORM
506 bool "Support for extended (non-PC) x86 platforms"
507 default y
508 ---help---
509 If you disable this option then the kernel will only support
510 standard PC platforms. (which covers the vast majority of
511 systems out there.)
512
513 If you enable this option then you'll be able to select support
514 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800515 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800516 ScaleMP vSMP
517 SGI Ultraviolet
518
519 If you have one of these systems, or if you want to build a
520 generic distribution kernel, say Y here - otherwise say N.
521endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800522# This is an alphabetically sorted list of 64 bit extended platforms
523# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800524config X86_NUMACHIP
525 bool "Numascale NumaChip"
526 depends on X86_64
527 depends on X86_EXTENDED_PLATFORM
528 depends on NUMA
529 depends on SMP
530 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700531 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800532 ---help---
533 Adds support for Numascale NumaChip large-SMP systems. Needed to
534 enable more than ~168 cores.
535 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100536
Ingo Molnar6a485652009-01-27 18:29:13 +0100537config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800538 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100539 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100540 select PARAVIRT
541 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800542 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300543 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100544 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100545 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
546 supposed to run on these EM64T-based machines. Only choose this option
547 if you have one of these machines.
548
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800549config X86_UV
550 bool "SGI Ultraviolet"
551 depends on X86_64
552 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500553 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800554 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700555 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200556 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800557 ---help---
558 This option is needed in order to support SGI Ultraviolet systems.
559 If you don't have one of these, you should say N here.
560
561# Following is an alphabetically sorted list of 32 bit extended platforms
562# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100563
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000564config X86_GOLDFISH
565 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100566 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000567 ---help---
568 Enable support for the Goldfish virtual platform used primarily
569 for Android development. Unless you are building for the Android
570 Goldfish emulator say N here.
571
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800572config X86_INTEL_CE
573 bool "CE4100 TV platform"
574 depends on PCI
575 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800576 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800577 depends on X86_32
578 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800579 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100580 select OF
581 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800582 ---help---
583 Select for the Intel CE media processor (CE4100) SOC.
584 This option compiles in support for the CE4100 SOC for settop
585 boxes and media devices.
586
David Cohen4cb9b002013-12-16 17:37:26 -0800587config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100588 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100589 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800590 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000591 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200592 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000593 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000594 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800595 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000596 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000597 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000598 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000599 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000600 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800601 Select to build a kernel capable of supporting Intel MID (Mobile
602 Internet Device) platform systems which do not have the PCI legacy
603 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000604
David Cohen4cb9b002013-12-16 17:37:26 -0800605 Intel MID platforms are based on an Intel processor and chipset which
606 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100607
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000608config X86_INTEL_QUARK
609 bool "Intel Quark platform support"
610 depends on X86_32
611 depends on X86_EXTENDED_PLATFORM
612 depends on X86_PLATFORM_DEVICES
613 depends on X86_TSC
614 depends on PCI
615 depends on PCI_GOANY
616 depends on X86_IO_APIC
617 select IOSF_MBI
618 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200619 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000620 ---help---
621 Select to include support for Quark X1000 SoC.
622 Say Y here if you have a Quark based system such as the Arduino
623 compatible Intel Galileo.
624
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000625config X86_INTEL_LPSS
626 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000627 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000628 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300629 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100630 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000631 ---help---
632 Select to build support for Intel Low Power Subsystem such as
633 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300634 things like clock tree (common clock framework) and pincontrol
635 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000636
Ken Xue92082a82015-02-06 08:27:51 +0800637config X86_AMD_PLATFORM_DEVICE
638 bool "AMD ACPI2Platform devices support"
639 depends on ACPI
640 select COMMON_CLK
641 select PINCTRL
642 ---help---
643 Select to interpret AMD specific ACPI device to platform device
644 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
645 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
646 implemented under PINCTRL subsystem.
647
David E. Boxced3ce72014-09-17 22:13:50 -0700648config IOSF_MBI
649 tristate "Intel SoC IOSF Sideband support for SoC platforms"
650 depends on PCI
651 ---help---
652 This option enables sideband register access support for Intel SoC
653 platforms. On these platforms the IOSF sideband is used in lieu of
654 MSR's for some register accesses, mostly but not limited to thermal
655 and power. Drivers may query the availability of this device to
656 determine if they need the sideband in order to work on these
657 platforms. The sideband is available on the following SoC products.
658 This list is not meant to be exclusive.
659 - BayTrail
660 - Braswell
661 - Quark
662
663 You should say Y if you are running a kernel on one of these SoC's.
664
David E. Boxed2226b2014-09-17 22:13:51 -0700665config IOSF_MBI_DEBUG
666 bool "Enable IOSF sideband access through debugfs"
667 depends on IOSF_MBI && DEBUG_FS
668 ---help---
669 Select this option to expose the IOSF sideband access registers (MCR,
670 MDR, MCRX) through debugfs to write and read register information from
671 different units on the SoC. This is most useful for obtaining device
672 state information for debug and analysis. As this is a general access
673 mechanism, users of this option would have specific knowledge of the
674 device they want to access.
675
676 If you don't require the option or are in doubt, say N.
677
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800678config X86_RDC321X
679 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100680 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800681 depends on X86_EXTENDED_PLATFORM
682 select M486
683 select X86_REBOOTFIXUPS
684 ---help---
685 This option is needed for RDC R-321x system-on-chip, also known
686 as R-8610-(G).
687 If you don't have one of these chips, you should say N here.
688
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100689config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100690 bool "Support non-standard 32-bit SMP architectures"
691 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800692 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100693 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800694 This option compiles in the bigsmp and STA2X11 default
695 subarchitectures. It is intended for a generic binary
696 kernel. If you select them all, kernel will probe it one by
697 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700698
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800699# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700700
Linus Torvaldsd949f362009-09-26 09:35:07 -0700701config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100702 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700703 # MCE code calls memory_failure():
704 depends on X86_MCE
705 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700706 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
707 depends on X86_64 || !SPARSEMEM
708 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700709
Alessandro Rubini83125a32012-04-04 19:40:21 +0200710config STA2X11
711 bool "STA2X11 Companion Chip Support"
712 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200713 select SWIOTLB
714 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200715 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200716 ---help---
717 This adds support for boards based on the STA2X11 IO-Hub,
718 a.k.a. "ConneXt". The chip is used in place of the standard
719 PC chipset, so all "standard" peripherals are missing. If this
720 option is selected the kernel will still be able to boot on
721 standard PC machines.
722
Shérab82148d12010-09-25 06:06:57 +0200723config X86_32_IRIS
724 tristate "Eurobraille/Iris poweroff module"
725 depends on X86_32
726 ---help---
727 The Iris machines from EuroBraille do not have APM or ACPI support
728 to shut themselves down properly. A special I/O sequence is
729 needed to do so, which is what this module does at
730 kernel shutdown.
731
732 This is only for Iris machines from EuroBraille.
733
734 If unused, say N.
735
Ingo Molnarae1e9132008-11-11 09:05:16 +0100736config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100737 def_bool y
738 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800739 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100740 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100741 Calculate simpler /proc/<PID>/wchan values. If this option
742 is disabled then wchan values will recurse back to the
743 caller function. This provides more accurate wchan values,
744 at the expense of slightly more scheduling overhead.
745
746 If in doubt, say "Y".
747
Borislav Petkov6276a072013-03-04 21:20:21 +0100748menuconfig HYPERVISOR_GUEST
749 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100750 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100751 Say Y here to enable options for running Linux under various hyper-
752 visors. This option enables basic hypervisor detection and platform
753 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100754
Borislav Petkov6276a072013-03-04 21:20:21 +0100755 If you say N, all options in this submenu will be skipped and
756 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100757
Borislav Petkov6276a072013-03-04 21:20:21 +0100758if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100759
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100760config PARAVIRT
761 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100762 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100763 This changes the kernel so it can modify itself when it is run
764 under a hypervisor, potentially improving performance significantly
765 over full virtualization. However, when run without a hypervisor
766 the kernel is theoretically slower and slightly larger.
767
Juergen Grossc00a2802018-08-28 09:40:21 +0200768config PARAVIRT_XXL
769 bool
770
Borislav Petkov6276a072013-03-04 21:20:21 +0100771config PARAVIRT_DEBUG
772 bool "paravirt-ops debugging"
773 depends on PARAVIRT && DEBUG_KERNEL
774 ---help---
775 Enable to debug paravirt_ops internals. Specifically, BUG if
776 a paravirt_op is missing when it is called.
777
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700778config PARAVIRT_SPINLOCKS
779 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700780 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700781 ---help---
782 Paravirtualized spinlocks allow a pvops backend to replace the
783 spinlock implementation with something virtualization-friendly
784 (for example, block the virtual CPU rather than spinning).
785
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530786 It has a minimal impact on native kernels and gives a nice performance
787 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700788
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530789 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700790
Zhao Yakuiecca25022019-04-30 11:45:23 +0800791config X86_HV_CALLBACK_VECTOR
792 def_bool n
793
Borislav Petkov6276a072013-03-04 21:20:21 +0100794source "arch/x86/xen/Kconfig"
795
796config KVM_GUEST
797 bool "KVM Guest support (including kvmclock)"
798 depends on PARAVIRT
799 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300800 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100801 default y
802 ---help---
803 This option enables various optimizations for running under the KVM
804 hypervisor. It includes a paravirtualized clock, so that instead
805 of relying on a PIT (or probably other) emulation by the
806 underlying device model, the host provides the guest with
807 timing infrastructure such as time of day, and system time
808
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300809config ARCH_CPUIDLE_HALTPOLL
810 def_bool n
811 prompt "Disable host haltpoll when loading haltpoll driver"
812 help
813 If virtualized under KVM, disable host haltpoll.
814
Maran Wilson77336072018-12-10 11:07:28 -0800815config PVH
816 bool "Support for running PVH guests"
817 ---help---
818 This option enables the PVH entry point for guest virtual machines
819 as specified in the x86/HVM direct boot ABI.
820
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530821config KVM_DEBUG_FS
822 bool "Enable debug information for KVM Guests in debugfs"
823 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530824 ---help---
825 This option enables collection of various statistics for KVM guest.
826 Statistics are displayed in debugfs filesystem. Enabling this option
827 may incur significant overhead.
828
Borislav Petkov6276a072013-03-04 21:20:21 +0100829config PARAVIRT_TIME_ACCOUNTING
830 bool "Paravirtual steal time accounting"
831 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100832 ---help---
833 Select this option to enable fine granularity task steal time
834 accounting. Time spent executing other tasks in parallel with
835 the current vCPU is discounted from the vCPU power. To account for
836 that, there can be a small performance impact.
837
838 If in doubt, say N here.
839
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200840config PARAVIRT_CLOCK
841 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200842
Jan Kiszka4a362602017-11-27 09:11:46 +0100843config JAILHOUSE_GUEST
844 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100845 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100846 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100847 ---help---
848 This option allows to run Linux as guest in a Jailhouse non-root
849 cell. You can leave this option disabled if you only want to start
850 Jailhouse and run Linux afterwards in the root cell.
851
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800852config ACRN_GUEST
853 bool "ACRN Guest support"
854 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800855 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800856 help
857 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
858 a flexible, lightweight reference open-source hypervisor, built with
859 real-time and safety-criticality in mind. It is built for embedded
860 IOT with small footprint and real-time features. More details can be
861 found in https://projectacrn.org/.
862
Borislav Petkov6276a072013-03-04 21:20:21 +0100863endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400864
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100865source "arch/x86/Kconfig.cpu"
866
867config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100868 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100869 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100870 ---help---
871 Use the IA-PC HPET (High Precision Event Timer) to manage
872 time in preference to the PIT and RTC, if a HPET is
873 present.
874 HPET is the next generation timer replacing legacy 8254s.
875 The HPET provides a stable time base on SMP
876 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200877 as it is off-chip. The interface used is documented
878 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100879
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100880 You can safely choose Y here. However, HPET will only be
881 activated if the platform and the BIOS support this feature.
882 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100883
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100884 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100885
886config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100887 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800888 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100889
Jacob Panbb24c472009-09-02 07:37:17 -0700890config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000891 def_bool y if X86_INTEL_MID
892 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100893 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000894 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700895 help
896 APB timer is the replacement for 8254, HPET on X86 MID platforms.
897 The APBT provides a stable time base on SMP
898 systems, unlike the TSC, but it is more expensive to access,
899 as it is off-chip. APB timers are always running regardless of CPU
900 C states, they are used as per CPU clockevent device when possible.
901
David Rientjes6a108a12011-01-20 14:44:16 -0800902# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100903# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700904config DMI
905 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800906 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800907 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100908 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700909 Enabled scanning of DMI to identify machine quirks. Say Y
910 here unless you have verified that your setup is not
911 affected by entries in the DMI blacklist. Required by PNP
912 BIOS code.
913
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100914config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700915 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200916 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100917 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200918 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100919 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921 GART based hardware IOMMUs.
922
923 The GART supports full DMA access for devices with 32-bit access
924 limitations, on systems with more than 3 GB. This is usually needed
925 for USB, sound, many IDE/SATA chipsets and some other devices.
926
927 Newer systems typically have a modern AMD IOMMU, supported via
928 the CONFIG_AMD_IOMMU=y config option.
929
930 In normal configurations this driver is only active when needed:
931 there's more than 3 GB of memory and the system contains a
932 32-bit limited device.
933
934 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100935
Mike Travis1184dc22008-05-12 21:21:12 +0200936config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200937 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700938 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800939 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100940 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200941 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200942 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100943
Ingo Molnaraec64872018-02-10 12:36:29 +0100944#
945# The maximum number of CPUs supported:
946#
947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948# and which can be configured interactively in the
949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950#
951# The ranges are different on 32-bit and 64-bit kernels, depending on
952# hardware capabilities and scalability features of the kernel.
953#
954# ( If MAXSMP is enabled we just use the highest possible value and disable
955# interactive configuration. )
956#
957
958config NR_CPUS_RANGE_BEGIN
959 int
960 default NR_CPUS_RANGE_END if MAXSMP
961 default 1 if !SMP
962 default 2
963
964config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800965 int
966 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100967 default 64 if SMP && X86_BIGSMP
968 default 8 if SMP && !X86_BIGSMP
969 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800970
Ingo Molnaraec64872018-02-10 12:36:29 +0100971config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800972 int
973 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500974 default 8192 if SMP && CPUMASK_OFFSTACK
975 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100976 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800977
Ingo Molnaraec64872018-02-10 12:36:29 +0100978config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800979 int
980 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100981 default 32 if X86_BIGSMP
982 default 8 if SMP
983 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800984
Ingo Molnaraec64872018-02-10 12:36:29 +0100985config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800986 int
987 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100988 default 8192 if MAXSMP
989 default 64 if SMP
990 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800991
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100992config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800993 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100996 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100997 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300999 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001000 minimum value which makes sense is 2.
1001
Ingo Molnaraec64872018-02-10 12:36:29 +01001002 This is purely to save memory: each supported CPU adds about 8KB
1003 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001004
1005config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001006 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001007
1008config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001009 def_bool y
1010 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001011 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001012 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001013 Multi-core scheduler support improves the CPU scheduler's decision
1014 making when dealing with multi-core CPU chips at a cost of slightly
1015 increased overhead in some places. If unsure say N here.
1016
Tim Chende966cf2016-11-29 10:43:27 -08001017config SCHED_MC_PRIO
1018 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001019 depends on SCHED_MC && CPU_SUP_INTEL
1020 select X86_INTEL_PSTATE
1021 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001022 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001023 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001024 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025 core ordering determined at manufacturing time, which allows
1026 certain cores to reach higher turbo frequencies (when running
1027 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001028
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001029 Enabling this kernel feature teaches the scheduler about
1030 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031 scheduler's CPU selection logic accordingly, so that higher
1032 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001033
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001034 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001035
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001036 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001037
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001038config UP_LATE_INIT
1039 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +01001040 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001041
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001042config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001043 bool "Local APIC support on uniprocessors" if !PCI_MSI
1044 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001045 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001046 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001047 A local APIC (Advanced Programmable Interrupt Controller) is an
1048 integrated interrupt controller in the CPU. If you have a single-CPU
1049 system which has a processor with a local APIC, you can say Y here to
1050 enable and use it. If you say Y here even though your machine doesn't
1051 have a local APIC, then the kernel will still run with no slowdown at
1052 all. The local APIC supports CPU-generated self-interrupts (timer,
1053 performance counters), and the NMI watchdog which detects hard
1054 lockups.
1055
1056config X86_UP_IOAPIC
1057 bool "IO-APIC support on uniprocessors"
1058 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001059 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001060 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061 SMP-capable replacement for PC-style interrupt controllers. Most
1062 SMP systems and many recent uniprocessor systems have one.
1063
1064 If you have a single-CPU system with an IO-APIC, you can say Y here
1065 to use it. If you say Y here even though your machine doesn't have
1066 an IO-APIC, then the kernel will still run with no slowdown at all.
1067
1068config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001069 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001070 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001071 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001072 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001073
1074config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001075 def_bool y
1076 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001077
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1079 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001080 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001081 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001082 This option enables a workaround that fixes a source of
1083 spurious interrupts. This is recommended when threaded
1084 interrupt handling is used on systems where the generation of
1085 superfluous "boot interrupts" cannot be disabled.
1086
1087 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1088 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1089 kernel does during interrupt handling). On chipsets where this
1090 boot IRQ generation cannot be disabled, this workaround keeps
1091 the original IRQ line masked so that only the equivalent "boot
1092 IRQ" is delivered to the CPUs. The workaround also tells the
1093 kernel to set up the IRQ handler on the boot IRQ line. In this
1094 way only one interrupt is delivered to the kernel. Otherwise
1095 the spurious second interrupt may cause the kernel to bring
1096 down (vital) interrupt lines.
1097
1098 Only affects "broken" chipsets. Interrupt sharing may be
1099 increased on these systems.
1100
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001101config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001102 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001103 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001104 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001105 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001106 Machine Check support allows the processor to notify the
1107 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001108 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001109 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001110
Tony Luck5de97c92017-03-27 11:33:03 +02001111config X86_MCELOG_LEGACY
1112 bool "Support for deprecated /dev/mcelog character device"
1113 depends on X86_MCE
1114 ---help---
1115 Enable support for /dev/mcelog which is needed by the old mcelog
1116 userspace logging daemon. Consider switching to the new generation
1117 rasdaemon solution.
1118
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001119config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001120 def_bool y
1121 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001122 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001123 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001124 Additional support for intel specific MCE features such as
1125 the thermal monitor.
1126
1127config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001128 def_bool y
1129 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001130 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001131 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001132 Additional support for AMD specific MCE features such as
1133 the DRAM Error Threshold.
1134
Andi Kleen4efc0672009-04-28 19:07:31 +02001135config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001136 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001137 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001138 ---help---
1139 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001140 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001141 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001142
Andi Kleenb2762682009-02-12 13:49:31 +01001143config X86_MCE_THRESHOLD
1144 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001145 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001146
Andi Kleenea149b32009-04-29 19:31:00 +02001147config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001148 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001149 tristate "Machine check injector support"
1150 ---help---
1151 Provide support for injecting machine checks for testing purposes.
1152 If you don't know what a machine check is and you don't do kernel
1153 QA it is safe to say n.
1154
Andi Kleen4efc0672009-04-28 19:07:31 +02001155config X86_THERMAL_VECTOR
1156 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001157 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001158
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001159source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001160
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001161config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001162 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001163 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001164 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001165 This option allows user programs to put the CPU into V8086
1166 mode, which is an 80286-era approximation of 16-bit real mode.
1167
1168 Some very old versions of X and/or vbetool require this option
1169 for user mode setting. Similarly, DOSEMU will use it if
1170 available to accelerate real mode DOS programs. However, any
1171 recent version of DOSEMU, X, or vbetool should be fully
1172 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001173 fall back to software emulation. Nevertheless, if you are using
1174 a 16-bit DOS program where 16-bit performance matters, vm86
1175 mode might be faster than emulation and you might want to
1176 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001177
Ingo Molnar1e642812015-09-05 08:58:10 +02001178 Note that any app that works on a 64-bit kernel is unlikely to
1179 need this option, as 64-bit kernels don't, and can't, support
1180 V8086 mode. This option is also unrelated to 16-bit protected
1181 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001182
Ingo Molnar1e642812015-09-05 08:58:10 +02001183 Enabling this option increases the complexity of the kernel
1184 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001185
Ingo Molnar1e642812015-09-05 08:58:10 +02001186 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001187
1188config VM86
1189 bool
1190 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001191
1192config X86_16BIT
1193 bool "Enable support for 16-bit segments" if EXPERT
1194 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001195 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001196 ---help---
1197 This option is required by programs like Wine to run 16-bit
1198 protected mode legacy code on x86 processors. Disabling
1199 this option saves about 300 bytes on i386, or around 6K text
1200 plus 16K runtime memory on x86-64,
1201
1202config X86_ESPFIX32
1203 def_bool y
1204 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001205
H. Peter Anvin197725d2014-05-04 10:00:49 -07001206config X86_ESPFIX64
1207 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001208 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001209
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001210config X86_VSYSCALL_EMULATION
1211 bool "Enable vsyscall emulation" if EXPERT
1212 default y
1213 depends on X86_64
1214 ---help---
1215 This enables emulation of the legacy vsyscall page. Disabling
1216 it is roughly equivalent to booting with vsyscall=none, except
1217 that it will also disable the helpful warning if a program
1218 tries to use a vsyscall. With this option set to N, offending
1219 programs will just segfault, citing addresses of the form
1220 0xffffffffff600?00.
1221
1222 This option is required by many programs built before 2013, and
1223 care should be used even with newer programs if set to N.
1224
1225 Disabling this option saves about 7K of kernel size and
1226 possibly 4K of additional runtime pagetable memory.
1227
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001228config X86_IOPL_IOPERM
1229 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001230 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001231 ---help---
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001232 This enables the ioperm() and iopl() syscalls which are necessary
1233 for legacy applications.
1234
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001235 Legacy IOPL support is an overbroad mechanism which allows user
1236 space aside of accessing all 65536 I/O ports also to disable
1237 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238 capabilities and permission from potentially active security
1239 modules.
1240
1241 The emulation restricts the functionality of the syscall to
1242 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001243 ability to disable interrupts from user space which would be
1244 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001245
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001246config TOSHIBA
1247 tristate "Toshiba Laptop support"
1248 depends on X86_32
1249 ---help---
1250 This adds a driver to safely access the System Management Mode of
1251 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252 not work on models with a Phoenix BIOS. The System Management Mode
1253 is used to set the BIOS and power saving options on Toshiba portables.
1254
1255 For information on utilities to make use of this driver see the
1256 Toshiba Linux utilities web site at:
1257 <http://www.buzzard.org.uk/toshiba/>.
1258
1259 Say Y if you intend to run this kernel on a Toshiba portable.
1260 Say N otherwise.
1261
1262config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001263 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001264 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001265 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001266 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001267 This option enables legacy /proc/i8k userspace interface in hwmon
1268 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269 temperature and allows controlling fan speeds of Dell laptops via
1270 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271 it reports also power and hotkey status. For fan speed control is
1272 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001273
Pali Rohár039ae582015-05-14 13:16:37 +02001274 Say Y if you intend to run this kernel on old Dell laptops or want to
1275 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001276 Say N otherwise.
1277
1278config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001279 bool "Enable X86 board specific fixups for reboot"
1280 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001281 ---help---
1282 This enables chipset and/or board specific fixups to be done
1283 in order to get reboot to work correctly. This is only needed on
1284 some combinations of hardware and BIOS. The symptom, for which
1285 this config is intended, is when reboot ends with a stalled/hung
1286 system.
1287
1288 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001289 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001290
1291 Say Y if you want to enable the fixup. Currently, it's safe to
1292 enable this option even if you don't need it.
1293 Say N otherwise.
1294
1295config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001296 bool "CPU microcode loading support"
1297 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001298 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001299 select FW_LOADER
1300 ---help---
1301 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001302 Intel and AMD processors. The Intel support is for the IA32 family,
1303 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1304 AMD support is for families 0x10 and later. You will obviously need
1305 the actual microcode binary data itself which is not shipped with
1306 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001307
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001308 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001309 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001310 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1311 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001312
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001313 In addition, you can build the microcode into the kernel. For that you
1314 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1315 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001316
Peter Oruba8d86f392008-07-28 18:44:21 +02001317config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001318 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001319 depends on MICROCODE
1320 default MICROCODE
1321 select FW_LOADER
1322 ---help---
1323 This options enables microcode patch loading support for Intel
1324 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001325
Alanb8989db2014-01-20 18:01:56 +00001326 For the current Intel microcode data package go to
1327 <https://downloadcenter.intel.com> and search for
1328 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001329
Peter Oruba80cc9f12008-07-28 18:44:22 +02001330config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001331 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001332 depends on MICROCODE
1333 select FW_LOADER
1334 ---help---
1335 If you select this option, microcode patch loading support for AMD
1336 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001337
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001338config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001339 bool "Ancient loading interface (DEPRECATED)"
1340 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001341 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001342 ---help---
1343 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1344 which was used by userspace tools like iucode_tool and microcode.ctl.
1345 It is inadequate because it runs too late to be able to properly
1346 load microcode on a machine and it needs special tools. Instead, you
1347 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001348 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001349
1350config X86_MSR
1351 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001352 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001353 This device gives privileged processes access to the x86
1354 Model-Specific Registers (MSRs). It is a character device with
1355 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1356 MSR accesses are directed to a specific CPU on multi-processor
1357 systems.
1358
1359config X86_CPUID
1360 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001361 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001362 This device gives processes access to the x86 CPUID instruction to
1363 be executed on a specific processor. It is a character device
1364 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1365 /dev/cpu/31/cpuid.
1366
1367choice
1368 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001369 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001370 depends on X86_32
1371
1372config NOHIGHMEM
1373 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001374 ---help---
1375 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1376 However, the address space of 32-bit x86 processors is only 4
1377 Gigabytes large. That means that, if you have a large amount of
1378 physical memory, not all of it can be "permanently mapped" by the
1379 kernel. The physical memory that's not permanently mapped is called
1380 "high memory".
1381
1382 If you are compiling a kernel which will never run on a machine with
1383 more than 1 Gigabyte total physical RAM, answer "off" here (default
1384 choice and suitable for most users). This will result in a "3GB/1GB"
1385 split: 3GB are mapped so that each process sees a 3GB virtual memory
1386 space and the remaining part of the 4GB virtual memory space is used
1387 by the kernel to permanently map as much physical memory as
1388 possible.
1389
1390 If the machine has between 1 and 4 Gigabytes physical RAM, then
1391 answer "4GB" here.
1392
1393 If more than 4 Gigabytes is used then answer "64GB" here. This
1394 selection turns Intel PAE (Physical Address Extension) mode on.
1395 PAE implements 3-level paging on IA32 processors. PAE is fully
1396 supported by Linux, PAE mode is implemented on all recent Intel
1397 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1398 then the kernel will not boot on CPUs that don't support PAE!
1399
1400 The actual amount of total physical memory will either be
1401 auto detected or can be forced by using a kernel command line option
1402 such as "mem=256M". (Try "man bootparam" or see the documentation of
1403 your boot loader (lilo or loadlin) about how to pass options to the
1404 kernel at boot time.)
1405
1406 If unsure, say "off".
1407
1408config HIGHMEM4G
1409 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001410 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001411 Select this if you have a 32-bit processor and between 1 and 4
1412 gigabytes of physical RAM.
1413
1414config HIGHMEM64G
1415 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001416 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001417 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001418 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001419 Select this if you have a 32-bit processor and more than 4
1420 gigabytes of physical RAM.
1421
1422endchoice
1423
1424choice
David Rientjes6a108a12011-01-20 14:44:16 -08001425 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001426 default VMSPLIT_3G
1427 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001428 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001429 Select the desired split between kernel and user memory.
1430
1431 If the address range available to the kernel is less than the
1432 physical memory installed, the remaining memory will be available
1433 as "high memory". Accessing high memory is a little more costly
1434 than low memory, as it needs to be mapped into the kernel first.
1435 Note that increasing the kernel address space limits the range
1436 available to user programs, making the address space there
1437 tighter. Selecting anything other than the default 3G/1G split
1438 will also likely make your kernel incompatible with binary-only
1439 kernel modules.
1440
1441 If you are not absolutely sure what you are doing, leave this
1442 option alone!
1443
1444 config VMSPLIT_3G
1445 bool "3G/1G user/kernel split"
1446 config VMSPLIT_3G_OPT
1447 depends on !X86_PAE
1448 bool "3G/1G user/kernel split (for full 1G low memory)"
1449 config VMSPLIT_2G
1450 bool "2G/2G user/kernel split"
1451 config VMSPLIT_2G_OPT
1452 depends on !X86_PAE
1453 bool "2G/2G user/kernel split (for full 2G low memory)"
1454 config VMSPLIT_1G
1455 bool "1G/3G user/kernel split"
1456endchoice
1457
1458config PAGE_OFFSET
1459 hex
1460 default 0xB0000000 if VMSPLIT_3G_OPT
1461 default 0x80000000 if VMSPLIT_2G
1462 default 0x78000000 if VMSPLIT_2G_OPT
1463 default 0x40000000 if VMSPLIT_1G
1464 default 0xC0000000
1465 depends on X86_32
1466
1467config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001468 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001469 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001470
1471config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001472 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001473 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001474 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001475 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001476 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001477 PAE is required for NX support, and furthermore enables
1478 larger swapspace support for non-overcommit purposes. It
1479 has the cost of more pagetable lookup overhead, and also
1480 consumes more pagetable space per process.
1481
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001482config X86_5LEVEL
1483 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001484 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001485 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001486 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001487 depends on X86_64
1488 ---help---
1489 5-level paging enables access to larger address space:
1490 upto 128 PiB of virtual address space and 4 PiB of
1491 physical address space.
1492
1493 It will be supported by future Intel CPUs.
1494
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001495 A kernel with the option enabled can be booted on machines that
1496 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001497
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001498 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001499 information.
1500
1501 Say N if unsure.
1502
Ingo Molnar10971ab2015-03-05 08:18:23 +01001503config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001504 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001505 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001506 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001507 Certain kernel features effectively disable kernel
1508 linear 1 GB mappings (even if the CPU otherwise
1509 supports them), so don't confuse the user by printing
1510 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001511
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001512config X86_CPA_STATISTICS
1513 bool "Enable statistic for Change Page Attribute"
1514 depends on DEBUG_FS
1515 ---help---
1516 Expose statistics about the Change Page Attribute mechanims, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001517 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001518 page mappings when mapping protections are changed.
1519
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001520config AMD_MEM_ENCRYPT
1521 bool "AMD Secure Memory Encryption (SME) support"
1522 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001523 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001524 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001525 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001526 ---help---
1527 Say yes to enable support for the encryption of system memory.
1528 This requires an AMD processor that supports Secure Memory
1529 Encryption (SME).
1530
1531config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1532 bool "Activate AMD Secure Memory Encryption (SME) by default"
1533 default y
1534 depends on AMD_MEM_ENCRYPT
1535 ---help---
1536 Say yes to have system memory encrypted by default if running on
1537 an AMD processor that supports Secure Memory Encryption (SME).
1538
1539 If set to Y, then the encryption of system memory can be
1540 deactivated with the mem_encrypt=off command line option.
1541
1542 If set to N, then the encryption of system memory can be
1543 activated with the mem_encrypt=on command line option.
1544
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001545# Common NUMA Features
1546config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001547 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001548 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001549 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1550 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001551 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001552 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001553
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001554 The kernel will try to allocate memory used by a CPU on the
1555 local memory controller of the CPU and add some more
1556 NUMA awareness to the kernel.
1557
Ingo Molnarc280ea52008-11-08 13:29:45 +01001558 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001559 (or later), AMD Opteron, or EM64T NUMA.
1560
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001561 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001562 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001563
1564 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001565
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001566config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001567 def_bool y
1568 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001569 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001570 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001571 Enable AMD NUMA node topology detection. You should say Y here if
1572 you have a multi processor AMD system. This uses an old method to
1573 read the NUMA configuration directly from the builtin Northbridge
1574 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1575 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001576
1577config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001578 def_bool y
1579 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001580 depends on X86_64 && NUMA && ACPI && PCI
1581 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001582 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001583 Enable ACPI SRAT based node topology detection.
1584
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001585# Some NUMA nodes have memory ranges that span
1586# other nodes. Even though a pfn is valid and
1587# between a node's start and end pfns, it may not
1588# reside on that node. See memmap_init_zone()
1589# for details.
1590config NODES_SPAN_OTHER_NODES
1591 def_bool y
1592 depends on X86_64_ACPI_NUMA
1593
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001594config NUMA_EMU
1595 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001596 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001597 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001598 Enable NUMA emulation. A flat machine will be split
1599 into virtual nodes when booted with "numa=fake=N", where N is the
1600 number of nodes. This is only useful for debugging.
1601
1602config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001603 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001604 range 1 10
1605 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001606 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001607 default "3"
1608 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001609 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001610 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001611 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001612
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001613config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001614 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001616
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001617config ARCH_FLATMEM_ENABLE
1618 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001619 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001620
1621config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001622 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001623 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001624 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001625
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001626config ARCH_SPARSEMEM_ENABLE
1627 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001628 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001629 select SPARSEMEM_STATIC if X86_32
1630 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1631
Tejun Heo3b166512011-04-01 11:15:12 +02001632config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001633 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001634
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001635config ARCH_SELECT_MEMORY_MODEL
1636 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001637 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001638
1639config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001640 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001641 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001642 help
1643 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001644 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001645 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001646
Tejun Heo3b166512011-04-01 11:15:12 +02001647config ARCH_PROC_KCORE_TEXT
1648 def_bool y
1649 depends on X86_64 && PROC_KCORE
1650
Avi Kivitya29815a2010-01-10 16:28:09 +02001651config ILLEGAL_POINTER_VALUE
1652 hex
1653 default 0 if X86_32
1654 default 0xdead000000000000 if X86_64
1655
Dan Williams7a678322015-08-19 00:34:34 -04001656config X86_PMEM_LEGACY_DEVICE
1657 bool
1658
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001659config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001660 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001661 depends on PHYS_ADDR_T_64BIT
1662 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001663 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001664 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001665 help
1666 Treat memory marked using the non-standard e820 type of 12 as used
1667 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1668 The kernel will offer these regions to the 'pmem' driver so
1669 they can be used for persistent storage.
1670
1671 Say Y if unsure.
1672
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001673config HIGHPTE
1674 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001675 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001676 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001677 The VM uses one page table entry for each page of physical memory.
1678 For systems with a lot of RAM, this can be wasteful of precious
1679 low memory. Setting this option will put user-space page table
1680 entries in high memory.
1681
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001682config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001683 bool "Check for low memory corruption"
1684 ---help---
1685 Periodically check for memory corruption in low memory, which
1686 is suspected to be caused by BIOS. Even when enabled in the
1687 configuration, it is disabled at runtime. Enable it by
1688 setting "memory_corruption_check=1" on the kernel command
1689 line. By default it scans the low 64k of memory every 60
1690 seconds; see the memory_corruption_check_size and
1691 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001692 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001693
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001694 When enabled with the default parameters, this option has
1695 almost no overhead, as it reserves a relatively small amount
1696 of memory and scans it infrequently. It both detects corruption
1697 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001698
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001699 It is, however, intended as a diagnostic tool; if repeatable
1700 BIOS-originated corruption always affects the same memory,
1701 you can use memmap= to prevent the kernel from using that
1702 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001703
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001704config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001705 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001706 depends on X86_CHECK_BIOS_CORRUPTION
1707 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001708 ---help---
1709 Set whether the default state of memory_corruption_check is
1710 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001711
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001712config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001713 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1714 default 64
1715 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001716 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001717 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001718
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001719 The first page contains BIOS data structures that the kernel
1720 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001721
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001722 By default we reserve the first 64K of physical RAM, as a
1723 number of BIOSes are known to corrupt that memory range
1724 during events such as suspend/resume or monitor cable
1725 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001726
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001727 You can set this to 4 if you are absolutely sure that you
1728 trust the BIOS to get all its memory reservations and usages
1729 right. If you know your BIOS have problems beyond the
1730 default 64K area, you can set this to 640 to avoid using the
1731 entire low memory range.
1732
1733 If you have doubts about the BIOS (e.g. suspend/resume does
1734 not work or there's kernel crashes after certain hardware
1735 hotplug events) then you might want to enable
1736 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1737 typical corruption patterns.
1738
1739 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001740
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001741config MATH_EMULATION
1742 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001743 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001744 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001745 ---help---
1746 Linux can emulate a math coprocessor (used for floating point
1747 operations) if you don't have one. 486DX and Pentium processors have
1748 a math coprocessor built in, 486SX and 386 do not, unless you added
1749 a 487DX or 387, respectively. (The messages during boot time can
1750 give you some hints here ["man dmesg"].) Everyone needs either a
1751 coprocessor or this emulation.
1752
1753 If you don't have a math coprocessor, you need to say Y here; if you
1754 say Y here even though you have a coprocessor, the coprocessor will
1755 be used nevertheless. (This behavior can be changed with the kernel
1756 command line option "no387", which comes handy if your coprocessor
1757 is broken. Try "man bootparam" or see the documentation of your boot
1758 loader (lilo or loadlin) about how to pass options to the kernel at
1759 boot time.) This means that it is a good idea to say Y here if you
1760 intend to use this kernel on different machines.
1761
1762 More information about the internals of the Linux math coprocessor
1763 emulation can be found in <file:arch/x86/math-emu/README>.
1764
1765 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1766 kernel, it won't hurt.
1767
1768config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001769 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001770 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001771 ---help---
1772 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1773 the Memory Type Range Registers (MTRRs) may be used to control
1774 processor access to memory ranges. This is most useful if you have
1775 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1776 allows bus write transfers to be combined into a larger transfer
1777 before bursting over the PCI/AGP bus. This can increase performance
1778 of image write operations 2.5 times or more. Saying Y here creates a
1779 /proc/mtrr file which may be used to manipulate your processor's
1780 MTRRs. Typically the X server should use this.
1781
1782 This code has a reasonably generic interface so that similar
1783 control registers on other processors can be easily supported
1784 as well:
1785
1786 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1787 Registers (ARRs) which provide a similar functionality to MTRRs. For
1788 these, the ARRs are used to emulate the MTRRs.
1789 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1790 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1791 write-combining. All of these processors are supported by this code
1792 and it makes sense to say Y here if you have one of them.
1793
1794 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1795 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1796 can lead to all sorts of problems, so it's good to say Y here.
1797
1798 You can safely say Y even if your machine doesn't have MTRRs, you'll
1799 just add about 9 KB to your kernel.
1800
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001801 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001802
Yinghai Lu95ffa242008-04-29 03:52:33 -07001803config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001804 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001805 prompt "MTRR cleanup support"
1806 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001807 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001808 Convert MTRR layout from continuous to discrete, so X drivers can
1809 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001810
Thomas Gleixneraba37282008-07-15 14:48:48 +02001811 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001812 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001813 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001814
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001815 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001816
1817config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001818 int "MTRR cleanup enable value (0-1)"
1819 range 0 1
1820 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001821 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001822 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001823 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001824
Yinghai Lu12031a62008-05-02 02:40:22 -07001825config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1826 int "MTRR cleanup spare reg num (0-7)"
1827 range 0 7
1828 default "1"
1829 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001830 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001831 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001832 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001833
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001834config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001835 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001836 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001837 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001838 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001839 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001840
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001841 PATs are the modern equivalents of MTRRs and are much more
1842 flexible than MTRRs.
1843
1844 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001845 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001846
1847 If unsure, say Y.
1848
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001849config ARCH_USES_PG_UNCACHED
1850 def_bool y
1851 depends on X86_PAT
1852
H. Peter Anvin628c6242011-07-31 13:59:29 -07001853config ARCH_RANDOM
1854 def_bool y
1855 prompt "x86 architectural random number generator" if EXPERT
1856 ---help---
1857 Enable the x86 architectural RDRAND instruction
1858 (Intel Bull Mountain technology) to generate random numbers.
1859 If supported, this is a high bandwidth, cryptographically
1860 secure hardware random number generator.
1861
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001862config X86_SMAP
1863 def_bool y
1864 prompt "Supervisor Mode Access Prevention" if EXPERT
1865 ---help---
1866 Supervisor Mode Access Prevention (SMAP) is a security
1867 feature in newer Intel processors. There is a small
1868 performance cost if this enabled and turned on; there is
1869 also a small increase in the kernel size if this is enabled.
1870
1871 If unsure, say Y.
1872
Babu Mogerb9718802019-11-05 21:25:32 +00001873config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001874 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001875 depends on CPU_SUP_INTEL || CPU_SUP_AMD
1876 prompt "User Mode Instruction Prevention" if EXPERT
Ricardo Neriaa35f892017-11-05 18:27:54 -08001877 ---help---
Babu Mogerb9718802019-11-05 21:25:32 +00001878 User Mode Instruction Prevention (UMIP) is a security feature in
1879 some x86 processors. If enabled, a general protection fault is
1880 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1881 executed in user mode. These instructions unnecessarily expose
1882 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001883
1884 The vast majority of applications do not use these instructions.
1885 For the very few that do, software emulation is provided in
1886 specific cases in protected and virtual-8086 modes. Emulated
1887 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001888
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001889config X86_INTEL_MPX
1890 prompt "Intel MPX (Memory Protection Extensions)"
1891 def_bool n
Rik van Rieldf3735c2017-09-06 16:25:11 -07001892 # Note: only available in 64-bit mode due to VMA flags shortage
1893 depends on CPU_SUP_INTEL && X86_64
1894 select ARCH_USES_HIGH_VMA_FLAGS
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001895 ---help---
1896 MPX provides hardware features that can be used in
1897 conjunction with compiler-instrumented code to check
1898 memory references. It is designed to detect buffer
1899 overflow or underflow bugs.
1900
1901 This option enables running applications which are
1902 instrumented or otherwise use MPX. It does not use MPX
1903 itself inside the kernel or to protect the kernel
1904 against bad memory references.
1905
1906 Enabling this option will make the kernel larger:
1907 ~8k of kernel text and 36 bytes of data on a 64-bit
1908 defconfig. It adds a long to the 'mm_struct' which
1909 will increase the kernel memory overhead of each
1910 process and adds some branches to paths used during
1911 exec() and munmap().
1912
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001913 For details, see Documentation/x86/intel_mpx.rst
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001914
1915 If unsure, say N.
1916
Dave Hansen35e97792016-02-12 13:02:00 -08001917config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001918 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001919 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001920 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001921 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001922 select ARCH_USES_HIGH_VMA_FLAGS
1923 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001924 ---help---
1925 Memory Protection Keys provides a mechanism for enforcing
1926 page-based protections, but without requiring modification of the
1927 page tables when an application changes protection domains.
1928
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001929 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001930
1931 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001932
Michal Hockodb616172019-10-23 12:35:50 +02001933choice
1934 prompt "TSX enable mode"
1935 depends on CPU_SUP_INTEL
1936 default X86_INTEL_TSX_MODE_OFF
1937 help
1938 Intel's TSX (Transactional Synchronization Extensions) feature
1939 allows to optimize locking protocols through lock elision which
1940 can lead to a noticeable performance boost.
1941
1942 On the other hand it has been shown that TSX can be exploited
1943 to form side channel attacks (e.g. TAA) and chances are there
1944 will be more of those attacks discovered in the future.
1945
1946 Therefore TSX is not enabled by default (aka tsx=off). An admin
1947 might override this decision by tsx=on the command line parameter.
1948 Even with TSX enabled, the kernel will attempt to enable the best
1949 possible TAA mitigation setting depending on the microcode available
1950 for the particular machine.
1951
1952 This option allows to set the default tsx mode between tsx=on, =off
1953 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1954 details.
1955
1956 Say off if not sure, auto if TSX is in use but it should be used on safe
1957 platforms or on if TSX is in use and the security aspect of tsx is not
1958 relevant.
1959
1960config X86_INTEL_TSX_MODE_OFF
1961 bool "off"
1962 help
1963 TSX is disabled if possible - equals to tsx=off command line parameter.
1964
1965config X86_INTEL_TSX_MODE_ON
1966 bool "on"
1967 help
1968 TSX is always enabled on TSX capable HW - equals the tsx=on command
1969 line parameter.
1970
1971config X86_INTEL_TSX_MODE_AUTO
1972 bool "auto"
1973 help
1974 TSX is enabled on TSX capable HW that is believed to be safe against
1975 side channel attacks- equals the tsx=auto command line parameter.
1976endchoice
1977
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001978config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001979 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001980 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001981 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001982 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001983 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001984 This enables the kernel to use EFI runtime services that are
1985 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001986
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001987 This option is only useful on systems that have EFI firmware.
1988 In addition, you should use the latest ELILO loader available
1989 at <http://elilo.sourceforge.net> in order to take advantage
1990 of EFI runtime services. However, even with this option, the
1991 resultant kernel should continue to boot on existing non-EFI
1992 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001993
Matt Fleming291f3632011-12-12 21:27:52 +00001994config EFI_STUB
1995 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001996 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001997 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001998 ---help---
1999 This kernel feature allows a bzImage to be loaded directly
2000 by EFI firmware without the use of a bootloader.
2001
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03002002 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00002003
Matt Fleming7d453ee2014-01-10 18:52:06 +00002004config EFI_MIXED
2005 bool "EFI mixed-mode support"
2006 depends on EFI_STUB && X86_64
2007 ---help---
2008 Enabling this feature allows a 64-bit kernel to be booted
2009 on a 32-bit firmware, provided that your CPU supports 64-bit
2010 mode.
2011
2012 Note that it is not possible to boot a mixed-mode enabled
2013 kernel via the EFI boot stub - a bootloader that supports
2014 the EFI handover protocol must be used.
2015
2016 If unsure, say N.
2017
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002018config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002019 def_bool y
2020 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002021 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002022 This kernel feature is useful for number crunching applications
2023 that may need to compute untrusted bytecode during their
2024 execution. By using pipes or other transports made available to
2025 the process as file descriptors supporting the read/write
2026 syscalls, it's possible to isolate those applications in
2027 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04002028 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002029 and the task is only allowed to execute a few safe syscalls
2030 defined by each seccomp mode.
2031
2032 If unsure, say Y. Only embedded should say N here.
2033
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002034source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002035
2036config KEXEC
2037 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07002038 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002039 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002040 kexec is a system call that implements the ability to shutdown your
2041 current kernel, and to start another kernel. It is like a reboot
2042 but it is independent of the system firmware. And like a reboot
2043 you can start any kernel with it, not just Linux.
2044
2045 The name comes from the similarity to the exec system call.
2046
2047 It is an ongoing process to be certain the hardware in a machine
2048 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002049 initially work for you. As of this writing the exact hardware
2050 interface is strongly in flux, so no good recommendation can be
2051 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002052
Vivek Goyal74ca3172014-08-29 15:18:46 -07002053config KEXEC_FILE
2054 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002055 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002056 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002057 depends on X86_64
2058 depends on CRYPTO=y
2059 depends on CRYPTO_SHA256=y
2060 ---help---
2061 This is new version of kexec system call. This system call is
2062 file based and takes file descriptors as system call argument
2063 for kernel and initramfs as opposed to list of segments as
2064 accepted by previous system call.
2065
AKASHI Takahirob799a092018-04-13 15:35:45 -07002066config ARCH_HAS_KEXEC_PURGATORY
2067 def_bool KEXEC_FILE
2068
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002069config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002070 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002071 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002072 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002073
2074 This option makes the kexec_file_load() syscall check for a valid
2075 signature of the kernel image. The image can still be loaded without
2076 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2077 there's a signature that we can check, then it must be valid.
2078
2079 In addition to this option, you need to enable signature
2080 verification for the corresponding kernel image type being
2081 loaded in order for this to work.
2082
2083config KEXEC_SIG_FORCE
2084 bool "Require a valid signature in kexec_file_load() syscall"
2085 depends on KEXEC_SIG
2086 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002087 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002088 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002089
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002090config KEXEC_BZIMAGE_VERIFY_SIG
2091 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002092 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002093 depends on SIGNED_PE_FILE_VERIFICATION
2094 select SYSTEM_TRUSTED_KEYRING
2095 ---help---
2096 Enable bzImage signature verification support.
2097
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002098config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002099 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002100 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002101 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002102 Generate crash dump after being started by kexec.
2103 This should be normally only set in special crash dump kernels
2104 which are loaded in the main kernel with kexec-tools into
2105 a specially reserved region and then later executed after
2106 a crash by kdump/kexec. The crash dump kernel must be compiled
2107 to a memory address not used by the main kernel or BIOS using
2108 PHYSICAL_START, or it must be built as a relocatable image
2109 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002110 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002111
Huang Ying3ab83522008-07-25 19:45:07 -07002112config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002113 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002114 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002115 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002116 Jump between original kernel and kexeced kernel and invoke
2117 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002118
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002119config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002120 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002121 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002122 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002123 This gives the physical address where the kernel is loaded.
2124
2125 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2126 bzImage will decompress itself to above physical address and
2127 run from there. Otherwise, bzImage will run from the address where
2128 it has been loaded by the boot loader and will ignore above physical
2129 address.
2130
2131 In normal kdump cases one does not have to set/change this option
2132 as now bzImage can be compiled as a completely relocatable image
2133 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2134 address. This option is mainly useful for the folks who don't want
2135 to use a bzImage for capturing the crash dump and want to use a
2136 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2137 to be specifically compiled to run from a specific memory area
2138 (normally a reserved region) and this option comes handy.
2139
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002140 So if you are using bzImage for capturing the crash dump,
2141 leave the value here unchanged to 0x1000000 and set
2142 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2143 for capturing the crash dump change this value to start of
2144 the reserved region. In other words, it can be set based on
2145 the "X" value as specified in the "crashkernel=YM@XM"
2146 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002147 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002148 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002149
2150 Usage of bzImage for capturing the crash dump is recommended as
2151 one does not have to build two kernels. Same kernel can be used
2152 as production kernel and capture kernel. Above option should have
2153 gone away after relocatable bzImage support is introduced. But it
2154 is present because there are users out there who continue to use
2155 vmlinux for dump capture. This option should go away down the
2156 line.
2157
2158 Don't change this unless you know what you are doing.
2159
2160config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002161 bool "Build a relocatable kernel"
2162 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002163 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002164 This builds a kernel image that retains relocation information
2165 so it can be loaded someplace besides the default 1MB.
2166 The relocations tend to make the kernel binary about 10% larger,
2167 but are discarded at runtime.
2168
2169 One use is for the kexec on panic case where the recovery kernel
2170 must live at a different physical address than the primary
2171 kernel.
2172
2173 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2174 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002175 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002176
Kees Cook8ab38202013-10-10 17:18:14 -07002177config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002178 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002179 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002180 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002181 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002182 In support of Kernel Address Space Layout Randomization (KASLR),
2183 this randomizes the physical address at which the kernel image
2184 is decompressed and the virtual address where the kernel
2185 image is mapped, as a security feature that deters exploit
2186 attempts relying on knowledge of the location of kernel
2187 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002188
Kees Cooked9f0072016-05-25 15:45:33 -07002189 On 64-bit, the kernel physical and virtual addresses are
2190 randomized separately. The physical address will be anywhere
2191 between 16MB and the top of physical memory (up to 64TB). The
2192 virtual address will be randomized from 16MB up to 1GB (9 bits
2193 of entropy). Note that this also reduces the memory space
2194 available to kernel modules from 1.5GB to 1GB.
2195
2196 On 32-bit, the kernel physical and virtual addresses are
2197 randomized together. They will be randomized from 16MB up to
2198 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002199
Baoquan Hee8581e32016-04-20 13:55:43 -07002200 Entropy is generated using the RDRAND instruction if it is
2201 supported. If RDTSC is supported, its value is mixed into
2202 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002203 supported, then entropy is read from the i8254 timer. The
2204 usable entropy is limited by the kernel being built using
2205 2GB addressing, and that PHYSICAL_ALIGN must be at a
2206 minimum of 2MB. As a result, only 10 bits of entropy are
2207 theoretically possible, but the implementations are further
2208 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002209
Ingo Molnar6807c842017-04-18 11:08:12 +02002210 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002211
2212# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002213config X86_NEED_RELOCS
2214 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002215 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002216
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002217config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002218 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002219 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002220 range 0x2000 0x1000000 if X86_32
2221 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002222 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002223 This value puts the alignment restrictions on physical address
2224 where kernel is loaded and run from. Kernel is compiled for an
2225 address which meets above alignment restriction.
2226
2227 If bootloader loads the kernel at a non-aligned address and
2228 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2229 address aligned to above value and run from there.
2230
2231 If bootloader loads the kernel at a non-aligned address and
2232 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2233 load address and decompress itself to the address it has been
2234 compiled for and run from there. The address for which kernel is
2235 compiled already meets above alignment restrictions. Hence the
2236 end result is that kernel runs from a physical address meeting
2237 above alignment restrictions.
2238
Kees Cooka0215062013-07-08 09:15:17 -07002239 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2240 this value must be a multiple of 0x200000.
2241
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002242 Don't change this unless you know what you are doing.
2243
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002244config DYNAMIC_MEMORY_LAYOUT
2245 bool
2246 ---help---
2247 This option makes base addresses of vmalloc and vmemmap as well as
2248 __PAGE_OFFSET movable during boot.
2249
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002250config RANDOMIZE_MEMORY
2251 bool "Randomize the kernel memory sections"
2252 depends on X86_64
2253 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002254 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002255 default RANDOMIZE_BASE
2256 ---help---
2257 Randomizes the base virtual address of kernel memory sections
2258 (physical memory mapping, vmalloc & vmemmap). This security feature
2259 makes exploits relying on predictable memory locations less reliable.
2260
2261 The order of allocations remains unchanged. Entropy is generated in
2262 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2263 configuration have in average 30,000 different possible virtual
2264 addresses for each memory section.
2265
Ingo Molnar6807c842017-04-18 11:08:12 +02002266 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002267
Thomas Garnier90397a42016-06-21 17:47:06 -07002268config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2269 hex "Physical memory mapping padding" if EXPERT
2270 depends on RANDOMIZE_MEMORY
2271 default "0xa" if MEMORY_HOTPLUG
2272 default "0x0"
2273 range 0x1 0x40 if MEMORY_HOTPLUG
2274 range 0x0 0x40
2275 ---help---
2276 Define the padding in terabytes added to the existing physical
2277 memory size during kernel memory randomization. It is useful
2278 for memory hotplug support but reduces the entropy available for
2279 address randomization.
2280
2281 If unsure, leave at the default value.
2282
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002283config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002284 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002285 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002286
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002287config BOOTPARAM_HOTPLUG_CPU0
2288 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002289 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002290 ---help---
2291 Set whether default state of cpu0_hotpluggable is on or off.
2292
2293 Say Y here to enable CPU0 hotplug by default. If this switch
2294 is turned on, there is no need to give cpu0_hotplug kernel
2295 parameter and the CPU0 hotplug feature is enabled by default.
2296
2297 Please note: there are two known CPU0 dependencies if you want
2298 to enable the CPU0 hotplug feature either by this switch or by
2299 cpu0_hotplug kernel parameter.
2300
2301 First, resume from hibernate or suspend always starts from CPU0.
2302 So hibernate and suspend are prevented if CPU0 is offline.
2303
2304 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2305 offline if any interrupt can not migrate out of CPU0. There may
2306 be other CPU0 dependencies.
2307
2308 Please make sure the dependencies are under your control before
2309 you enable this feature.
2310
2311 Say N if you don't want to enable CPU0 hotplug feature by default.
2312 You still can enable the CPU0 hotplug feature at boot by kernel
2313 parameter cpu0_hotplug.
2314
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002315config DEBUG_HOTPLUG_CPU0
2316 def_bool n
2317 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002318 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002319 ---help---
2320 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2321 soon as possible and boots up userspace with CPU0 offlined. User
2322 can online CPU0 back after boot time.
2323
2324 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2325 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2326 compilation or giving cpu0_hotplug kernel parameter at boot.
2327
2328 If unsure, say N.
2329
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002330config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002331 def_bool n
2332 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002333 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002334 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002335 Certain buggy versions of glibc will crash if they are
2336 presented with a 32-bit vDSO that is not mapped at the address
2337 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002338
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002339 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2340 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2341 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2342 the only released version with the bug, but OpenSUSE 9
2343 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002344
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002345 The symptom of the bug is that everything crashes on startup, saying:
2346 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2347
2348 Saying Y here changes the default value of the vdso32 boot
2349 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2350 This works around the glibc bug but hurts performance.
2351
2352 If unsure, say N: if you are compiling your own kernel, you
2353 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002354
Kees Cook3dc33bd2015-08-12 17:55:19 -07002355choice
2356 prompt "vsyscall table for legacy applications"
2357 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002358 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002359 help
2360 Legacy user code that does not know how to find the vDSO expects
2361 to be able to issue three syscalls by calling fixed addresses in
2362 kernel space. Since this location is not randomized with ASLR,
2363 it can be used to assist security vulnerability exploitation.
2364
2365 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002366 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002367
2368 On a system with recent enough glibc (2.14 or newer) and no
2369 static binaries, you can say None without a performance penalty
2370 to improve security.
2371
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002372 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002373
Kees Cook3dc33bd2015-08-12 17:55:19 -07002374 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002375 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002376 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002377 The kernel traps and emulates calls into the fixed vsyscall
2378 address mapping. This makes the mapping non-executable, but
2379 it still contains readable known contents, which could be
2380 used in certain rare security vulnerability exploits. This
2381 configuration is recommended when using legacy userspace
2382 that still uses vsyscalls along with legacy binary
2383 instrumentation tools that require code to be readable.
2384
2385 An example of this type of legacy userspace is running
2386 Pin on an old binary that still uses vsyscalls.
2387
2388 config LEGACY_VSYSCALL_XONLY
2389 bool "Emulate execution only"
2390 help
2391 The kernel traps and emulates calls into the fixed vsyscall
2392 address mapping and does not allow reads. This
2393 configuration is recommended when userspace might use the
2394 legacy vsyscall area but support for legacy binary
2395 instrumentation of legacy code is not needed. It mitigates
2396 certain uses of the vsyscall area as an ASLR-bypassing
2397 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002398
2399 config LEGACY_VSYSCALL_NONE
2400 bool "None"
2401 help
2402 There will be no vsyscall mapping at all. This will
2403 eliminate any risk of ASLR bypass due to the vsyscall
2404 fixed address mapping. Attempts to use the vsyscalls
2405 will be reported to dmesg, so that either old or
2406 malicious userspace programs can be identified.
2407
2408endchoice
2409
Tim Bird516cbf32008-08-12 12:52:36 -07002410config CMDLINE_BOOL
2411 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002412 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002413 Allow for specifying boot arguments to the kernel at
2414 build time. On some systems (e.g. embedded ones), it is
2415 necessary or convenient to provide some or all of the
2416 kernel boot arguments with the kernel itself (that is,
2417 to not rely on the boot loader to provide them.)
2418
2419 To compile command line arguments into the kernel,
2420 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002421 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002422
2423 Systems with fully functional boot loaders (i.e. non-embedded)
2424 should leave this option set to 'N'.
2425
2426config CMDLINE
2427 string "Built-in kernel command string"
2428 depends on CMDLINE_BOOL
2429 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002430 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002431 Enter arguments here that should be compiled into the kernel
2432 image and used at boot time. If the boot loader provides a
2433 command line at boot time, it is appended to this string to
2434 form the full kernel command line, when the system boots.
2435
2436 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2437 change this behavior.
2438
2439 In most cases, the command line (whether built-in or provided
2440 by the boot loader) should specify the device for the root
2441 file system.
2442
2443config CMDLINE_OVERRIDE
2444 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002445 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002446 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002447 Set this option to 'Y' to have the kernel ignore the boot loader
2448 command line, and use ONLY the built-in command line.
2449
2450 This is used to work around broken boot loaders. This should
2451 be set to 'N' under normal conditions.
2452
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002453config MODIFY_LDT_SYSCALL
2454 bool "Enable the LDT (local descriptor table)" if EXPERT
2455 default y
2456 ---help---
2457 Linux can allow user programs to install a per-process x86
2458 Local Descriptor Table (LDT) using the modify_ldt(2) system
2459 call. This is required to run 16-bit or segmented code such as
2460 DOSEMU or some Wine programs. It is also used by some very old
2461 threading libraries.
2462
2463 Enabling this feature adds a small amount of overhead to
2464 context switches and increases the low-level kernel attack
2465 surface. Disabling it removes the modify_ldt(2) system call.
2466
2467 Saying 'N' here may make sense for embedded or server kernels.
2468
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002469source "kernel/livepatch/Kconfig"
2470
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002471endmenu
2472
Michal Hocko3072e412017-09-08 16:11:39 -07002473config ARCH_HAS_ADD_PAGES
2474 def_bool y
2475 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2476
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002477config ARCH_ENABLE_MEMORY_HOTPLUG
2478 def_bool y
2479 depends on X86_64 || (X86_32 && HIGHMEM)
2480
Gary Hade35551052008-10-31 10:52:03 -07002481config ARCH_ENABLE_MEMORY_HOTREMOVE
2482 def_bool y
2483 depends on MEMORY_HOTPLUG
2484
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002485config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002486 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002487 depends on NUMA
2488
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002489config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2490 def_bool y
2491 depends on X86_64 || X86_PAE
2492
Naoya Horiguchic177c812014-06-04 16:05:35 -07002493config ARCH_ENABLE_HUGEPAGE_MIGRATION
2494 def_bool y
2495 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2496
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002497config ARCH_ENABLE_THP_MIGRATION
2498 def_bool y
2499 depends on X86_64 && TRANSPARENT_HUGEPAGE
2500
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002501menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002502
2503config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002504 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002505 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002506
2507source "kernel/power/Kconfig"
2508
2509source "drivers/acpi/Kconfig"
2510
Feng Tangefafc8b2009-08-14 15:23:29 -04002511source "drivers/sfi/Kconfig"
2512
Andi Kleena6b68072008-01-30 13:32:49 +01002513config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002514 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002515 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002516
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002517menuconfig APM
2518 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002519 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002520 ---help---
2521 APM is a BIOS specification for saving power using several different
2522 techniques. This is mostly useful for battery powered laptops with
2523 APM compliant BIOSes. If you say Y here, the system time will be
2524 reset after a RESUME operation, the /proc/apm device will provide
2525 battery status information, and user-space programs will receive
2526 notification of APM "events" (e.g. battery status change).
2527
2528 If you select "Y" here, you can disable actual use of the APM
2529 BIOS by passing the "apm=off" option to the kernel at boot time.
2530
2531 Note that the APM support is almost completely disabled for
2532 machines with more than one CPU.
2533
2534 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002535 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002536 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002537 <http://www.tldp.org/docs.html#howto>.
2538
2539 This driver does not spin down disk drives (see the hdparm(8)
2540 manpage ("man 8 hdparm") for that), and it doesn't turn off
2541 VESA-compliant "green" monitors.
2542
2543 This driver does not support the TI 4000M TravelMate and the ACER
2544 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2545 desktop machines also don't have compliant BIOSes, and this driver
2546 may cause those machines to panic during the boot phase.
2547
2548 Generally, if you don't have a battery in your machine, there isn't
2549 much point in using this driver and you should say N. If you get
2550 random kernel OOPSes or reboots that don't seem to be related to
2551 anything, try disabling/enabling this option (or disabling/enabling
2552 APM in your BIOS).
2553
2554 Some other things you should try when experiencing seemingly random,
2555 "weird" problems:
2556
2557 1) make sure that you have enough swap space and that it is
2558 enabled.
2559 2) pass the "no-hlt" option to the kernel
2560 3) switch on floating point emulation in the kernel and pass
2561 the "no387" option to the kernel
2562 4) pass the "floppy=nodma" option to the kernel
2563 5) pass the "mem=4M" option to the kernel (thereby disabling
2564 all but the first 4 MB of RAM)
2565 6) make sure that the CPU is not over clocked.
2566 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2567 8) disable the cache from your BIOS settings
2568 9) install a fan for the video card or exchange video RAM
2569 10) install a better fan for the CPU
2570 11) exchange RAM chips
2571 12) exchange the motherboard.
2572
2573 To compile this driver as a module, choose M here: the
2574 module will be called apm.
2575
2576if APM
2577
2578config APM_IGNORE_USER_SUSPEND
2579 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002580 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002581 This option will ignore USER SUSPEND requests. On machines with a
2582 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2583 series notebooks, it is necessary to say Y because of a BIOS bug.
2584
2585config APM_DO_ENABLE
2586 bool "Enable PM at boot time"
2587 ---help---
2588 Enable APM features at boot time. From page 36 of the APM BIOS
2589 specification: "When disabled, the APM BIOS does not automatically
2590 power manage devices, enter the Standby State, enter the Suspend
2591 State, or take power saving steps in response to CPU Idle calls."
2592 This driver will make CPU Idle calls when Linux is idle (unless this
2593 feature is turned off -- see "Do CPU IDLE calls", below). This
2594 should always save battery power, but more complicated APM features
2595 will be dependent on your BIOS implementation. You may need to turn
2596 this option off if your computer hangs at boot time when using APM
2597 support, or if it beeps continuously instead of suspending. Turn
2598 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2599 T400CDT. This is off by default since most machines do fine without
2600 this feature.
2601
2602config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002603 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002604 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002605 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2607 On some machines, this can activate improved power savings, such as
2608 a slowed CPU clock rate, when the machine is idle. These idle calls
2609 are made after the idle loop has run for some length of time (e.g.,
2610 333 mS). On some machines, this will cause a hang at boot time or
2611 whenever the CPU becomes idle. (On machines with more than one CPU,
2612 this option does nothing.)
2613
2614config APM_DISPLAY_BLANK
2615 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002616 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002617 Enable console blanking using the APM. Some laptops can use this to
2618 turn off the LCD backlight when the screen blanker of the Linux
2619 virtual console blanks the screen. Note that this is only used by
2620 the virtual console screen blanker, and won't turn off the backlight
2621 when using the X Window system. This also doesn't have anything to
2622 do with your VESA-compliant power-saving monitor. Further, this
2623 option doesn't work for all laptops -- it might not turn off your
2624 backlight at all, or it might print a lot of errors to the console,
2625 especially if you are using gpm.
2626
2627config APM_ALLOW_INTS
2628 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002629 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002630 Normally we disable external interrupts while we are making calls to
2631 the APM BIOS as a measure to lessen the effects of a badly behaving
2632 BIOS implementation. The BIOS should reenable interrupts if it
2633 needs to. Unfortunately, some BIOSes do not -- especially those in
2634 many of the newer IBM Thinkpads. If you experience hangs when you
2635 suspend, try setting this to Y. Otherwise, say N.
2636
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002637endif # APM
2638
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002639source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002640
2641source "drivers/cpuidle/Kconfig"
2642
Andy Henroid27471fd2008-10-09 11:45:22 -07002643source "drivers/idle/Kconfig"
2644
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002645endmenu
2646
2647
2648menu "Bus options (PCI etc.)"
2649
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002650choice
2651 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002652 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002653 default PCI_GOANY
2654 ---help---
2655 On PCI systems, the BIOS can be used to detect the PCI devices and
2656 determine their configuration. However, some old PCI motherboards
2657 have BIOS bugs and may crash if this is done. Also, some embedded
2658 PCI-based systems don't have any BIOS at all. Linux can also try to
2659 detect the PCI hardware directly without using the BIOS.
2660
2661 With this option, you can specify how Linux should detect the
2662 PCI devices. If you choose "BIOS", the BIOS will be used,
2663 if you choose "Direct", the BIOS won't be used, and if you
2664 choose "MMConfig", then PCI Express MMCONFIG will be used.
2665 If you choose "Any", the kernel will try MMCONFIG, then the
2666 direct access method and falls back to the BIOS if that doesn't
2667 work. If unsure, go with the default, which is "Any".
2668
2669config PCI_GOBIOS
2670 bool "BIOS"
2671
2672config PCI_GOMMCONFIG
2673 bool "MMConfig"
2674
2675config PCI_GODIRECT
2676 bool "Direct"
2677
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002678config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002679 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002680 depends on OLPC
2681
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002682config PCI_GOANY
2683 bool "Any"
2684
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002685endchoice
2686
2687config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002688 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002689 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002690
2691# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2692config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002693 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002694 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002695
2696config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002697 bool "Support mmconfig PCI config space access" if X86_64
2698 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002699 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002700 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002701
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002702config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002703 def_bool y
2704 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002705
Alex Nixonb5401a92010-03-18 16:31:34 -04002706config PCI_XEN
2707 def_bool y
2708 depends on PCI && XEN
2709 select SWIOTLB_XEN
2710
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002711config MMCONF_FAM10H
2712 def_bool y
2713 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002714
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002715config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002716 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002717 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002718 help
2719 Read the PCI windows out of the CNB20LE host bridge. This allows
2720 PCI hotplug to work on systems with the CNB20LE chipset which do
2721 not have ACPI.
2722
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002723 There's no public spec for this chipset, and this functionality
2724 is known to be incomplete.
2725
2726 You should say N unless you know you need this.
2727
William Breathitt Gray3a495512016-05-27 18:08:27 -04002728config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002729 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002730 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002731 Expose ISA bus device drivers and options available for selection and
2732 configuration. Enable this option if your target machine has an ISA
2733 bus. ISA is an older system, displaced by PCI and newer bus
2734 architectures -- if your target machine is modern, it probably does
2735 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002736
2737 If unsure, say N.
2738
David Rientjes1c00f012011-03-22 16:34:59 -07002739# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002740config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002741 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2742 default y
2743 help
2744 Enables ISA-style DMA support for devices requiring such controllers.
2745 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002746
Linus Torvalds51e68d02016-05-21 10:25:19 -07002747if X86_32
2748
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002749config ISA
2750 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002751 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002752 Find out whether you have ISA slots on your motherboard. ISA is the
2753 name of a bus system, i.e. the way the CPU talks to the other stuff
2754 inside your box. Other bus systems are PCI, EISA, MicroChannel
2755 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2756 newer boards don't support it. If you have ISA, say Y, otherwise N.
2757
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002758config SCx200
2759 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002760 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002761 This provides basic support for National Semiconductor's
2762 (now AMD's) Geode processors. The driver probes for the
2763 PCI-IDs of several on-chip devices, so its a good dependency
2764 for other scx200_* drivers.
2765
2766 If compiled as a module, the driver is named scx200.
2767
2768config SCx200HR_TIMER
2769 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002770 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002771 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002772 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002773 This driver provides a clocksource built upon the on-chip
2774 27MHz high-resolution timer. Its also a workaround for
2775 NSC Geode SC-1100's buggy TSC, which loses time when the
2776 processor goes idle (as is done by the scheduler). The
2777 other workaround is idle=poll boot option.
2778
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002779config OLPC
2780 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002781 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002782 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002783 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002784 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002785 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002786 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002787 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002788 Add support for detecting the unique features of the OLPC
2789 XO hardware.
2790
Daniel Drakea3128582011-06-25 17:34:10 +01002791config OLPC_XO1_PM
2792 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002793 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002794 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002795 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002796
Daniel Drakecfee9592011-06-25 17:34:17 +01002797config OLPC_XO1_RTC
2798 bool "OLPC XO-1 Real Time Clock"
2799 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2800 ---help---
2801 Add support for the XO-1 real time clock, which can be used as a
2802 programmable wakeup source.
2803
Daniel Drake7feda8e2011-06-25 17:34:12 +01002804config OLPC_XO1_SCI
2805 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002806 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002807 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002808 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002809 ---help---
2810 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002811 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002812 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002813 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002814 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002815 - AC adapter status updates
2816 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002817
Daniel Drakea0f30f52011-06-25 17:34:18 +01002818config OLPC_XO15_SCI
2819 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002820 depends on OLPC && ACPI
2821 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002822 ---help---
2823 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2824 - EC-driven system wakeups
2825 - AC adapter status updates
2826 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002827
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002828config ALIX
2829 bool "PCEngines ALIX System Support (LED setup)"
2830 select GPIOLIB
2831 ---help---
2832 This option enables system support for the PCEngines ALIX.
2833 At present this just sets up LEDs for GPIO control on
2834 ALIX2/3/6 boards. However, other system specific setup should
2835 get added here.
2836
2837 Note: You must still enable the drivers for GPIO and LED support
2838 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2839
2840 Note: You have to set alix.force=1 for boards with Award BIOS.
2841
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002842config NET5501
2843 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2844 select GPIOLIB
2845 ---help---
2846 This option enables system support for the Soekris Engineering net5501.
2847
Philip A. Prindeville31970592012-01-14 01:45:39 -07002848config GEOS
2849 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2850 select GPIOLIB
2851 depends on DMI
2852 ---help---
2853 This option enables system support for the Traverse Technologies GEOS.
2854
Vivien Didelot7d029122013-01-04 16:18:14 -05002855config TS5500
2856 bool "Technologic Systems TS-5500 platform support"
2857 depends on MELAN
2858 select CHECK_SIGNATURE
2859 select NEW_LEDS
2860 select LEDS_CLASS
2861 ---help---
2862 This option enables system support for the Technologic Systems TS-5500.
2863
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002864endif # X86_32
2865
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002866config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002867 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002868 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002869
David Herrmanne3263ab2013-08-02 14:05:22 +02002870config X86_SYSFB
2871 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2872 help
2873 Firmwares often provide initial graphics framebuffers so the BIOS,
2874 bootloader or kernel can show basic video-output during boot for
2875 user-guidance and debugging. Historically, x86 used the VESA BIOS
2876 Extensions and EFI-framebuffers for this, which are mostly limited
2877 to x86.
2878 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2879 framebuffers so the new generic system-framebuffer drivers can be
2880 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002881 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002882 drivers like efifb, vesafb and uvesafb can pick it up.
2883 If this option is not selected, all system framebuffers are always
2884 marked as fallback platform framebuffers as usual.
2885
2886 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2887 not be able to pick up generic system framebuffers if this option
2888 is selected. You are highly encouraged to enable simplefb as
2889 replacement if you select this option. simplefb can correctly deal
2890 with generic system framebuffers. But you should still keep vesafb
2891 and others enabled as fallback if a system framebuffer is
2892 incompatible with simplefb.
2893
2894 If unsure, say Y.
2895
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002896endmenu
2897
2898
Christoph Hellwig15724972018-07-31 13:39:30 +02002899menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002900
2901config IA32_EMULATION
2902 bool "IA32 Emulation"
2903 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002904 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002905 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002906 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002907 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002908 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002909 Include code to run legacy 32-bit programs under a
2910 64-bit kernel. You should likely turn this on, unless you're
2911 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002912
2913config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002914 tristate "IA32 a.out support"
2915 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002916 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002917 ---help---
2918 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002919
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002920config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002921 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002922 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002923 ---help---
2924 Include code to run binaries for the x32 native 32-bit ABI
2925 for 64-bit processors. An x32 process gets access to the
2926 full 64-bit register file and wide data path while leaving
2927 pointers at 32 bits for smaller memory footprint.
2928
2929 You will need a recent binutils (2.22 or later) with
2930 elf32_x86_64 support enabled to compile a kernel with this
2931 option set.
2932
Ingo Molnar953fee12016-11-15 10:22:52 +01002933config COMPAT_32
2934 def_bool y
2935 depends on IA32_EMULATION || X86_32
2936 select HAVE_UID16
2937 select OLD_SIGSUSPEND3
2938
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002939config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002940 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002941 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002942
Jan Beulich3120e252012-09-10 12:41:45 +01002943if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002944config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002945 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002946
2947config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002948 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002949 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002950endif
David Howellsee009e4a02011-03-07 15:06:20 +00002951
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002952endmenu
2953
2954
Keith Packarde5beae12008-11-03 18:21:45 +01002955config HAVE_ATOMIC_IOMAP
2956 def_bool y
2957 depends on X86_32
2958
Alessandro Rubini4692d772012-04-04 19:39:58 +02002959config X86_DEV_DMA_OPS
2960 bool
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002961
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002962source "drivers/firmware/Kconfig"
2963
Avi Kivityedf88412007-12-16 11:02:48 +02002964source "arch/x86/kvm/Kconfig"