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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
Daniel Borkmann81c22042019-12-09 16:08:03 +010096 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +010097 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -070098 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -070099 select ARCH_WANTS_THP_SWAP if X86_64
Shile Zhang10916702019-12-04 08:46:31 +0800100 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200101 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
103 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700105 select EDAC_ATOMIC_SCRUB
106 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200107 select GENERIC_CLOCKEVENTS
108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
109 select GENERIC_CLOCKEVENTS_MIN_ADJUST
110 select GENERIC_CMOS_UPDATE
111 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100112 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200113 select GENERIC_EARLY_IOREMAP
114 select GENERIC_FIND_FIRST_BIT
115 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200118 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200120 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200121 select GENERIC_IRQ_SHOW
122 select GENERIC_PENDING_IRQ if SMP
123 select GENERIC_SMP_IDLE_THREAD
124 select GENERIC_STRNCPY_FROM_USER
125 select GENERIC_STRNLEN_USER
126 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100127 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000128 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700129 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200130 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200131 select HAVE_ACPI_APEI if ACPI
132 select HAVE_ACPI_APEI_NMI if ACPI
133 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200134 select HAVE_ARCH_AUDITSYSCALL
135 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
136 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700137 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800138 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800139 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200140 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800141 select HAVE_ARCH_MMAP_RND_BITS if MMU
142 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300143 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700144 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200145 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700146 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300147 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200148 select HAVE_ARCH_TRACEHOOK
149 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800150 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700151 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100152 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900153 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200154 select HAVE_CMPXCHG_DOUBLE
155 select HAVE_CMPXCHG_LOCAL
156 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700157 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200158 select HAVE_C_RECORDMCOUNT
159 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700160 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400161 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900162 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500163 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800164 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700165 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100166 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700167 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700168 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400169 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200170 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200171 select HAVE_FUNCTION_GRAPH_TRACER
172 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200173 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530174 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200175 select HAVE_IDE
176 select HAVE_IOREMAP_PROT
177 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
178 select HAVE_IRQ_TIME_ACCOUNTING
179 select HAVE_KERNEL_BZIP2
180 select HAVE_KERNEL_GZIP
181 select HAVE_KERNEL_LZ4
182 select HAVE_KERNEL_LZMA
183 select HAVE_KERNEL_LZO
184 select HAVE_KERNEL_XZ
185 select HAVE_KPROBES
186 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900187 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200188 select HAVE_KRETPROBES
189 select HAVE_KVM
190 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200191 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200192 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500193 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800194 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700195 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200196 select HAVE_OPROFILE
197 select HAVE_OPTPROBES
198 select HAVE_PCSPKR_PLATFORM
199 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200200 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700201 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100202 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200203 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200204 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstra48a8b972018-08-22 17:30:16 +0200205 select HAVE_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200206 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200207 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900208 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900209 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100210 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400211 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200212 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200213 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300214 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100215 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200216 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100217 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200218 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100219 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000220 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200221 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500222 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200223 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200224 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500225 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200226 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700227 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200228 select USER_STACKTRACE_SUPPORT
229 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200230 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800231 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530232
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200233config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100234 def_bool y
235 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200236
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700237config OUTPUT_FORMAT
238 string
239 default "elf32-i386" if X86_32
240 default "elf64-x86-64" if X86_64
241
Sam Ravnborg73531902008-05-25 23:03:18 +0200242config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200243 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200244 default "arch/x86/configs/i386_defconfig" if X86_32
245 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200246
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100247config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100248 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100249
250config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100251 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100252
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100254 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100255
Daniel Cashman9e08f572016-01-14 15:20:06 -0800256config ARCH_MMAP_RND_BITS_MIN
257 default 28 if 64BIT
258 default 8
259
260config ARCH_MMAP_RND_BITS_MAX
261 default 32 if 64BIT
262 default 16
263
264config ARCH_MMAP_RND_COMPAT_BITS_MIN
265 default 8
266
267config ARCH_MMAP_RND_COMPAT_BITS_MAX
268 default 16
269
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100270config SBUS
271 bool
272
273config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100274 def_bool y
275 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100276
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100277config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100278 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100279 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000280 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
281
282config GENERIC_BUG_RELATIVE_POINTERS
283 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100284
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100285config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100286 def_bool y
287 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100288
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100289config GENERIC_CALIBRATE_DELAY
290 def_bool y
291
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800292config ARCH_HAS_CPU_RELAX
293 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100294
Pekka Enberg1b27d052008-04-28 02:12:22 -0700295config ARCH_HAS_CACHE_LINE_SIZE
296 def_bool y
297
Dave Hansen316d0972018-04-20 15:20:28 -0700298config ARCH_HAS_FILTER_PGPROT
299 def_bool y
300
Mike Travisdd5af902008-01-30 13:33:32 +0100301config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900302 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100303
Tejun Heo08fc4582009-08-14 15:00:49 +0900304config NEED_PER_CPU_EMBED_FIRST_CHUNK
305 def_bool y
306
307config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900308 def_bool y
309
Johannes Berg801e4062007-12-08 02:12:39 +0100310config ARCH_HIBERNATION_POSSIBLE
311 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100312
Johannes Bergf4cb5702007-12-08 02:14:00 +0100313config ARCH_SUSPEND_POSSIBLE
314 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100315
Steve Capper53313b22013-04-30 08:03:42 +0100316config ARCH_WANT_GENERAL_HUGETLB
317 def_bool y
318
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100319config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000320 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100322config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000323 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100324
Akinobu Mita6a11f752009-03-31 15:23:17 -0700325config ARCH_SUPPORTS_DEBUG_PAGEALLOC
326 def_bool y
327
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300328config KASAN_SHADOW_OFFSET
329 hex
330 depends on KASAN
331 default 0xdffffc0000000000
332
Shane Wang69575d32009-09-01 18:25:07 -0700333config HAVE_INTEL_TXT
334 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700335 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700336
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100337config X86_32_SMP
338 def_bool y
339 depends on X86_32 && SMP
340
341config X86_64_SMP
342 def_bool y
343 depends on X86_64 && SMP
344
Tejun Heoccbeed32009-02-09 22:17:40 +0900345config X86_32_LAZY_GS
346 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900347 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900348
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530349config ARCH_SUPPORTS_UPROBES
350 def_bool y
351
Rob Herringd20642f2014-04-18 17:19:54 -0500352config FIX_EARLYCON_MEM
353 def_bool y
354
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300355config DYNAMIC_PHYSICAL_MASK
356 bool
357
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700358config PGTABLE_LEVELS
359 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300360 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700361 default 4 if X86_64
362 default 3 if X86_PAE
363 default 2
364
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900365config CC_HAS_SANE_STACKPROTECTOR
366 bool
367 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
368 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
369 help
370 We have to make sure stack protector is unconditionally disabled if
371 the compiler produces broken code.
372
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100373menu "Processor type and features"
374
Randy Dunlap5ee71532012-01-16 11:57:18 -0800375config ZONE_DMA
376 bool "DMA memory allocation support" if EXPERT
377 default y
378 help
379 DMA memory allocation support allows devices with less than 32-bit
380 addressing to allocate within the first 16MB of address space.
381 Disable if no such devices will be used.
382
383 If unsure, say Y.
384
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100385config SMP
386 bool "Symmetric multi-processing support"
387 ---help---
388 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800389 a system with only one CPU, say N. If you have a system with more
390 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100391
Robert Graffham4a474152014-01-23 15:55:29 -0800392 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100393 machines, but will use only one CPU of a multiprocessor machine. If
394 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800395 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100396 will run faster if you say N here.
397
398 Note that if you say Y here and choose architecture "586" or
399 "Pentium" under "Processor family", the kernel will not work on 486
400 architectures. Similarly, multiprocessor kernels for the "PPro"
401 architecture may not work on all Pentium based boards.
402
403 People using multiprocessor machines who say Y here should also say
404 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
405 Management" code will be disabled if you say Y here.
406
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300407 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300408 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100409 <http://www.tldp.org/docs.html#howto>.
410
411 If you don't know what to do here, say N.
412
Josh Triplett9def39be2013-10-30 08:09:45 -0700413config X86_FEATURE_NAMES
414 bool "Processor feature human-readable names" if EMBEDDED
415 default y
416 ---help---
417 This option compiles in a table of x86 feature bits and corresponding
418 names. This is required to support /proc/cpuinfo and a few kernel
419 messages. You can disable this to save space, at the expense of
420 making those few kernel messages show numeric feature bits instead.
421
422 If in doubt, say Y.
423
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800424config X86_X2APIC
425 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200426 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800427 ---help---
428 This enables x2apic support on CPUs that have this feature.
429
430 This allows 32-bit apic IDs (so it can support very large systems),
431 and accesses the local apic via MSRs not via mmio.
432
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800433 If you don't know what to do here, say N.
434
Yinghai Lu6695c852008-06-19 12:13:09 -0700435config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700436 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000437 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200438 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100439 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700440 For old smp systems that do not have proper acpi support. Newer systems
441 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700442
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000443config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100444 def_bool y
445 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000446
David Woodhouse76b04382018-01-11 21:46:25 +0000447config RETPOLINE
448 bool "Avoid speculative indirect branches in kernel"
449 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100450 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000451 help
452 Compile kernel with the retpoline compiler options to guard against
453 kernel-to-user data leaks by avoiding speculative indirect
454 branches. Requires a compiler with -mindirect-branch=thunk-extern
455 support for full protection. The kernel may run slower.
456
Johannes Weinere6d42932019-01-29 17:44:36 -0500457config X86_CPU_RESCTRL
458 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000459 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100460 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800461 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700462 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500463 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000464
465 Provide support for the allocation and monitoring of system resources
466 usage by the CPU.
467
468 Intel calls this Intel Resource Director Technology
469 (Intel(R) RDT). More information about RDT can be found in the
470 Intel x86 Architecture Software Developer Manual.
471
472 AMD calls this AMD Platform Quality of Service (AMD QoS).
473 More information about AMD QoS can be found in the AMD64 Technology
474 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700475
476 Say N if unsure.
477
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800478if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800479config X86_BIGSMP
480 bool "Support for big SMP systems with more than 8 CPUs"
481 depends on SMP
482 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -0800483 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800484
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800485config X86_EXTENDED_PLATFORM
486 bool "Support for extended (non-PC) x86 platforms"
487 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100488 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100489 If you disable this option then the kernel will only support
490 standard PC platforms. (which covers the vast majority of
491 systems out there.)
492
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800493 If you enable this option then you'll be able to select support
494 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100495 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800496 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800497 RDC R-321x SoC
498 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200499 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200500 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100501
502 If you have one of these systems, or if you want to build a
503 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800504endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100505
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800506if X86_64
507config X86_EXTENDED_PLATFORM
508 bool "Support for extended (non-PC) x86 platforms"
509 default y
510 ---help---
511 If you disable this option then the kernel will only support
512 standard PC platforms. (which covers the vast majority of
513 systems out there.)
514
515 If you enable this option then you'll be able to select support
516 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800517 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800518 ScaleMP vSMP
519 SGI Ultraviolet
520
521 If you have one of these systems, or if you want to build a
522 generic distribution kernel, say Y here - otherwise say N.
523endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800524# This is an alphabetically sorted list of 64 bit extended platforms
525# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800526config X86_NUMACHIP
527 bool "Numascale NumaChip"
528 depends on X86_64
529 depends on X86_EXTENDED_PLATFORM
530 depends on NUMA
531 depends on SMP
532 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700533 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800534 ---help---
535 Adds support for Numascale NumaChip large-SMP systems. Needed to
536 enable more than ~168 cores.
537 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100538
Ingo Molnar6a485652009-01-27 18:29:13 +0100539config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800540 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100541 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100542 select PARAVIRT
543 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800544 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300545 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100546 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100547 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
548 supposed to run on these EM64T-based machines. Only choose this option
549 if you have one of these machines.
550
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800551config X86_UV
552 bool "SGI Ultraviolet"
553 depends on X86_64
554 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500555 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800556 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700557 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200558 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800559 ---help---
560 This option is needed in order to support SGI Ultraviolet systems.
561 If you don't have one of these, you should say N here.
562
563# Following is an alphabetically sorted list of 32 bit extended platforms
564# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100565
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000566config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100567 bool "Goldfish (Virtual Platform)"
568 depends on X86_EXTENDED_PLATFORM
569 ---help---
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000570 Enable support for the Goldfish virtual platform used primarily
571 for Android development. Unless you are building for the Android
572 Goldfish emulator say N here.
573
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800574config X86_INTEL_CE
575 bool "CE4100 TV platform"
576 depends on PCI
577 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800578 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800579 depends on X86_32
580 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800581 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100582 select OF
583 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800584 ---help---
585 Select for the Intel CE media processor (CE4100) SOC.
586 This option compiles in support for the CE4100 SOC for settop
587 boxes and media devices.
588
David Cohen4cb9b002013-12-16 17:37:26 -0800589config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100590 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100591 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800592 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000593 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200594 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000595 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000596 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800597 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000598 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000599 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000600 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000601 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000602 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800603 Select to build a kernel capable of supporting Intel MID (Mobile
604 Internet Device) platform systems which do not have the PCI legacy
605 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000606
David Cohen4cb9b002013-12-16 17:37:26 -0800607 Intel MID platforms are based on an Intel processor and chipset which
608 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100609
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000610config X86_INTEL_QUARK
611 bool "Intel Quark platform support"
612 depends on X86_32
613 depends on X86_EXTENDED_PLATFORM
614 depends on X86_PLATFORM_DEVICES
615 depends on X86_TSC
616 depends on PCI
617 depends on PCI_GOANY
618 depends on X86_IO_APIC
619 select IOSF_MBI
620 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200621 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000622 ---help---
623 Select to include support for Quark X1000 SoC.
624 Say Y here if you have a Quark based system such as the Arduino
625 compatible Intel Galileo.
626
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000627config X86_INTEL_LPSS
628 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000629 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000630 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300631 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100632 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000633 ---help---
634 Select to build support for Intel Low Power Subsystem such as
635 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300636 things like clock tree (common clock framework) and pincontrol
637 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000638
Ken Xue92082a82015-02-06 08:27:51 +0800639config X86_AMD_PLATFORM_DEVICE
640 bool "AMD ACPI2Platform devices support"
641 depends on ACPI
642 select COMMON_CLK
643 select PINCTRL
644 ---help---
645 Select to interpret AMD specific ACPI device to platform device
646 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
647 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
648 implemented under PINCTRL subsystem.
649
David E. Boxced3ce72014-09-17 22:13:50 -0700650config IOSF_MBI
651 tristate "Intel SoC IOSF Sideband support for SoC platforms"
652 depends on PCI
653 ---help---
654 This option enables sideband register access support for Intel SoC
655 platforms. On these platforms the IOSF sideband is used in lieu of
656 MSR's for some register accesses, mostly but not limited to thermal
657 and power. Drivers may query the availability of this device to
658 determine if they need the sideband in order to work on these
659 platforms. The sideband is available on the following SoC products.
660 This list is not meant to be exclusive.
661 - BayTrail
662 - Braswell
663 - Quark
664
665 You should say Y if you are running a kernel on one of these SoC's.
666
David E. Boxed2226b2014-09-17 22:13:51 -0700667config IOSF_MBI_DEBUG
668 bool "Enable IOSF sideband access through debugfs"
669 depends on IOSF_MBI && DEBUG_FS
670 ---help---
671 Select this option to expose the IOSF sideband access registers (MCR,
672 MDR, MCRX) through debugfs to write and read register information from
673 different units on the SoC. This is most useful for obtaining device
674 state information for debug and analysis. As this is a general access
675 mechanism, users of this option would have specific knowledge of the
676 device they want to access.
677
678 If you don't require the option or are in doubt, say N.
679
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800680config X86_RDC321X
681 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100682 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800683 depends on X86_EXTENDED_PLATFORM
684 select M486
685 select X86_REBOOTFIXUPS
686 ---help---
687 This option is needed for RDC R-321x system-on-chip, also known
688 as R-8610-(G).
689 If you don't have one of these chips, you should say N here.
690
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100691config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100692 bool "Support non-standard 32-bit SMP architectures"
693 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800694 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100695 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800696 This option compiles in the bigsmp and STA2X11 default
697 subarchitectures. It is intended for a generic binary
698 kernel. If you select them all, kernel will probe it one by
699 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700700
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800701# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700702
Linus Torvaldsd949f362009-09-26 09:35:07 -0700703config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100704 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700705 # MCE code calls memory_failure():
706 depends on X86_MCE
707 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700708 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
709 depends on X86_64 || !SPARSEMEM
710 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700711
Alessandro Rubini83125a32012-04-04 19:40:21 +0200712config STA2X11
713 bool "STA2X11 Companion Chip Support"
714 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200715 select SWIOTLB
716 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200717 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200718 ---help---
719 This adds support for boards based on the STA2X11 IO-Hub,
720 a.k.a. "ConneXt". The chip is used in place of the standard
721 PC chipset, so all "standard" peripherals are missing. If this
722 option is selected the kernel will still be able to boot on
723 standard PC machines.
724
Shérab82148d12010-09-25 06:06:57 +0200725config X86_32_IRIS
726 tristate "Eurobraille/Iris poweroff module"
727 depends on X86_32
728 ---help---
729 The Iris machines from EuroBraille do not have APM or ACPI support
730 to shut themselves down properly. A special I/O sequence is
731 needed to do so, which is what this module does at
732 kernel shutdown.
733
734 This is only for Iris machines from EuroBraille.
735
736 If unused, say N.
737
Ingo Molnarae1e9132008-11-11 09:05:16 +0100738config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100739 def_bool y
740 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800741 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100742 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100743 Calculate simpler /proc/<PID>/wchan values. If this option
744 is disabled then wchan values will recurse back to the
745 caller function. This provides more accurate wchan values,
746 at the expense of slightly more scheduling overhead.
747
748 If in doubt, say "Y".
749
Borislav Petkov6276a072013-03-04 21:20:21 +0100750menuconfig HYPERVISOR_GUEST
751 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100752 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100753 Say Y here to enable options for running Linux under various hyper-
754 visors. This option enables basic hypervisor detection and platform
755 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100756
Borislav Petkov6276a072013-03-04 21:20:21 +0100757 If you say N, all options in this submenu will be skipped and
758 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100759
Borislav Petkov6276a072013-03-04 21:20:21 +0100760if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100761
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100762config PARAVIRT
763 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100764 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100765 This changes the kernel so it can modify itself when it is run
766 under a hypervisor, potentially improving performance significantly
767 over full virtualization. However, when run without a hypervisor
768 the kernel is theoretically slower and slightly larger.
769
Juergen Grossc00a2802018-08-28 09:40:21 +0200770config PARAVIRT_XXL
771 bool
772
Borislav Petkov6276a072013-03-04 21:20:21 +0100773config PARAVIRT_DEBUG
774 bool "paravirt-ops debugging"
775 depends on PARAVIRT && DEBUG_KERNEL
776 ---help---
777 Enable to debug paravirt_ops internals. Specifically, BUG if
778 a paravirt_op is missing when it is called.
779
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700780config PARAVIRT_SPINLOCKS
781 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700782 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700783 ---help---
784 Paravirtualized spinlocks allow a pvops backend to replace the
785 spinlock implementation with something virtualization-friendly
786 (for example, block the virtual CPU rather than spinning).
787
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530788 It has a minimal impact on native kernels and gives a nice performance
789 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700790
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530791 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700792
Zhao Yakuiecca25022019-04-30 11:45:23 +0800793config X86_HV_CALLBACK_VECTOR
794 def_bool n
795
Borislav Petkov6276a072013-03-04 21:20:21 +0100796source "arch/x86/xen/Kconfig"
797
798config KVM_GUEST
799 bool "KVM Guest support (including kvmclock)"
800 depends on PARAVIRT
801 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300802 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100803 default y
804 ---help---
805 This option enables various optimizations for running under the KVM
806 hypervisor. It includes a paravirtualized clock, so that instead
807 of relying on a PIT (or probably other) emulation by the
808 underlying device model, the host provides the guest with
809 timing infrastructure such as time of day, and system time
810
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300811config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100812 def_bool n
813 prompt "Disable host haltpoll when loading haltpoll driver"
814 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300815 If virtualized under KVM, disable host haltpoll.
816
Maran Wilson77336072018-12-10 11:07:28 -0800817config PVH
818 bool "Support for running PVH guests"
819 ---help---
820 This option enables the PVH entry point for guest virtual machines
821 as specified in the x86/HVM direct boot ABI.
822
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530823config KVM_DEBUG_FS
824 bool "Enable debug information for KVM Guests in debugfs"
825 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530826 ---help---
827 This option enables collection of various statistics for KVM guest.
828 Statistics are displayed in debugfs filesystem. Enabling this option
829 may incur significant overhead.
830
Borislav Petkov6276a072013-03-04 21:20:21 +0100831config PARAVIRT_TIME_ACCOUNTING
832 bool "Paravirtual steal time accounting"
833 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100834 ---help---
835 Select this option to enable fine granularity task steal time
836 accounting. Time spent executing other tasks in parallel with
837 the current vCPU is discounted from the vCPU power. To account for
838 that, there can be a small performance impact.
839
840 If in doubt, say N here.
841
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200842config PARAVIRT_CLOCK
843 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200844
Jan Kiszka4a362602017-11-27 09:11:46 +0100845config JAILHOUSE_GUEST
846 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100847 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100848 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100849 ---help---
850 This option allows to run Linux as guest in a Jailhouse non-root
851 cell. You can leave this option disabled if you only want to start
852 Jailhouse and run Linux afterwards in the root cell.
853
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800854config ACRN_GUEST
855 bool "ACRN Guest support"
856 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800857 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800858 help
859 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
860 a flexible, lightweight reference open-source hypervisor, built with
861 real-time and safety-criticality in mind. It is built for embedded
862 IOT with small footprint and real-time features. More details can be
863 found in https://projectacrn.org/.
864
Borislav Petkov6276a072013-03-04 21:20:21 +0100865endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400866
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100867source "arch/x86/Kconfig.cpu"
868
869config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100870 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100871 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100872 ---help---
873 Use the IA-PC HPET (High Precision Event Timer) to manage
874 time in preference to the PIT and RTC, if a HPET is
875 present.
876 HPET is the next generation timer replacing legacy 8254s.
877 The HPET provides a stable time base on SMP
878 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200879 as it is off-chip. The interface used is documented
880 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100881
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100882 You can safely choose Y here. However, HPET will only be
883 activated if the platform and the BIOS support this feature.
884 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100885
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100886 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100887
888config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100889 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800890 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100891
Jacob Panbb24c472009-09-02 07:37:17 -0700892config APB_TIMER
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100893 def_bool y if X86_INTEL_MID
894 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
895 select DW_APB_TIMER
896 depends on X86_INTEL_MID && SFI
897 help
898 APB timer is the replacement for 8254, HPET on X86 MID platforms.
899 The APBT provides a stable time base on SMP
900 systems, unlike the TSC, but it is more expensive to access,
901 as it is off-chip. APB timers are always running regardless of CPU
902 C states, they are used as per CPU clockevent device when possible.
Jacob Panbb24c472009-09-02 07:37:17 -0700903
David Rientjes6a108a12011-01-20 14:44:16 -0800904# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100905# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700906config DMI
907 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800908 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800909 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100910 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700911 Enabled scanning of DMI to identify machine quirks. Say Y
912 here unless you have verified that your setup is not
913 affected by entries in the DMI blacklist. Required by PNP
914 BIOS code.
915
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100916config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700917 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200918 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100919 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200920 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100921 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200922 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
923 GART based hardware IOMMUs.
924
925 The GART supports full DMA access for devices with 32-bit access
926 limitations, on systems with more than 3 GB. This is usually needed
927 for USB, sound, many IDE/SATA chipsets and some other devices.
928
929 Newer systems typically have a modern AMD IOMMU, supported via
930 the CONFIG_AMD_IOMMU=y config option.
931
932 In normal configurations this driver is only active when needed:
933 there's more than 3 GB of memory and the system contains a
934 32-bit limited device.
935
936 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100937
Mike Travis1184dc22008-05-12 21:21:12 +0200938config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200939 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700940 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800941 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100942 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200943 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200944 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100945
Ingo Molnaraec64872018-02-10 12:36:29 +0100946#
947# The maximum number of CPUs supported:
948#
949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
950# and which can be configured interactively in the
951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
952#
953# The ranges are different on 32-bit and 64-bit kernels, depending on
954# hardware capabilities and scalability features of the kernel.
955#
956# ( If MAXSMP is enabled we just use the highest possible value and disable
957# interactive configuration. )
958#
959
960config NR_CPUS_RANGE_BEGIN
961 int
962 default NR_CPUS_RANGE_END if MAXSMP
963 default 1 if !SMP
964 default 2
965
966config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800967 int
968 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100969 default 64 if SMP && X86_BIGSMP
970 default 8 if SMP && !X86_BIGSMP
971 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800972
Ingo Molnaraec64872018-02-10 12:36:29 +0100973config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800974 int
975 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500976 default 8192 if SMP && CPUMASK_OFFSTACK
977 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100978 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800979
Ingo Molnaraec64872018-02-10 12:36:29 +0100980config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800981 int
982 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100983 default 32 if X86_BIGSMP
984 default 8 if SMP
985 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800986
Ingo Molnaraec64872018-02-10 12:36:29 +0100987config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800988 int
989 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100990 default 8192 if MAXSMP
991 default 64 if SMP
992 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800993
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100994config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800995 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100996 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
997 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100998 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100999 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001000 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001001 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001002 minimum value which makes sense is 2.
1003
Ingo Molnaraec64872018-02-10 12:36:29 +01001004 This is purely to save memory: each supported CPU adds about 8KB
1005 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001006
1007config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001008 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001009
1010config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001011 def_bool y
1012 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001013 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001014 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001015 Multi-core scheduler support improves the CPU scheduler's decision
1016 making when dealing with multi-core CPU chips at a cost of slightly
1017 increased overhead in some places. If unsure say N here.
1018
Tim Chende966cf2016-11-29 10:43:27 -08001019config SCHED_MC_PRIO
1020 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001021 depends on SCHED_MC && CPU_SUP_INTEL
1022 select X86_INTEL_PSTATE
1023 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001024 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001025 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001026 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1027 core ordering determined at manufacturing time, which allows
1028 certain cores to reach higher turbo frequencies (when running
1029 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001030
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001031 Enabling this kernel feature teaches the scheduler about
1032 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1033 scheduler's CPU selection logic accordingly, so that higher
1034 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001035
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001036 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001037
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001038 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001039
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001040config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001041 def_bool y
1042 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001043
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001044config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001045 bool "Local APIC support on uniprocessors" if !PCI_MSI
1046 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001047 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001048 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001049 A local APIC (Advanced Programmable Interrupt Controller) is an
1050 integrated interrupt controller in the CPU. If you have a single-CPU
1051 system which has a processor with a local APIC, you can say Y here to
1052 enable and use it. If you say Y here even though your machine doesn't
1053 have a local APIC, then the kernel will still run with no slowdown at
1054 all. The local APIC supports CPU-generated self-interrupts (timer,
1055 performance counters), and the NMI watchdog which detects hard
1056 lockups.
1057
1058config X86_UP_IOAPIC
1059 bool "IO-APIC support on uniprocessors"
1060 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001061 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001062 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1063 SMP-capable replacement for PC-style interrupt controllers. Most
1064 SMP systems and many recent uniprocessor systems have one.
1065
1066 If you have a single-CPU system with an IO-APIC, you can say Y here
1067 to use it. If you say Y here even though your machine doesn't have
1068 an IO-APIC, then the kernel will still run with no slowdown at all.
1069
1070config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001071 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001072 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001073 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001074 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001075
1076config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001077 def_bool y
1078 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001079
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001080config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1081 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001082 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001083 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001084 This option enables a workaround that fixes a source of
1085 spurious interrupts. This is recommended when threaded
1086 interrupt handling is used on systems where the generation of
1087 superfluous "boot interrupts" cannot be disabled.
1088
1089 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1090 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1091 kernel does during interrupt handling). On chipsets where this
1092 boot IRQ generation cannot be disabled, this workaround keeps
1093 the original IRQ line masked so that only the equivalent "boot
1094 IRQ" is delivered to the CPUs. The workaround also tells the
1095 kernel to set up the IRQ handler on the boot IRQ line. In this
1096 way only one interrupt is delivered to the kernel. Otherwise
1097 the spurious second interrupt may cause the kernel to bring
1098 down (vital) interrupt lines.
1099
1100 Only affects "broken" chipsets. Interrupt sharing may be
1101 increased on these systems.
1102
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001103config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001104 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001105 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001106 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001107 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001108 Machine Check support allows the processor to notify the
1109 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001110 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001111 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001112
Tony Luck5de97c92017-03-27 11:33:03 +02001113config X86_MCELOG_LEGACY
1114 bool "Support for deprecated /dev/mcelog character device"
1115 depends on X86_MCE
1116 ---help---
1117 Enable support for /dev/mcelog which is needed by the old mcelog
1118 userspace logging daemon. Consider switching to the new generation
1119 rasdaemon solution.
1120
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001121config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001122 def_bool y
1123 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001124 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001125 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001126 Additional support for intel specific MCE features such as
1127 the thermal monitor.
1128
1129config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001130 def_bool y
1131 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001132 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001133 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001134 Additional support for AMD specific MCE features such as
1135 the DRAM Error Threshold.
1136
Andi Kleen4efc0672009-04-28 19:07:31 +02001137config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001138 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001139 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001140 ---help---
1141 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001142 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001143 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001144
Andi Kleenb2762682009-02-12 13:49:31 +01001145config X86_MCE_THRESHOLD
1146 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001147 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001148
Andi Kleenea149b32009-04-29 19:31:00 +02001149config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001150 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001151 tristate "Machine check injector support"
1152 ---help---
1153 Provide support for injecting machine checks for testing purposes.
1154 If you don't know what a machine check is and you don't do kernel
1155 QA it is safe to say n.
1156
Andi Kleen4efc0672009-04-28 19:07:31 +02001157config X86_THERMAL_VECTOR
1158 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001159 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001160
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001161source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001162
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001163config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001164 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001165 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001166 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001167 This option allows user programs to put the CPU into V8086
1168 mode, which is an 80286-era approximation of 16-bit real mode.
1169
1170 Some very old versions of X and/or vbetool require this option
1171 for user mode setting. Similarly, DOSEMU will use it if
1172 available to accelerate real mode DOS programs. However, any
1173 recent version of DOSEMU, X, or vbetool should be fully
1174 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001175 fall back to software emulation. Nevertheless, if you are using
1176 a 16-bit DOS program where 16-bit performance matters, vm86
1177 mode might be faster than emulation and you might want to
1178 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001179
Ingo Molnar1e642812015-09-05 08:58:10 +02001180 Note that any app that works on a 64-bit kernel is unlikely to
1181 need this option, as 64-bit kernels don't, and can't, support
1182 V8086 mode. This option is also unrelated to 16-bit protected
1183 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001184
Ingo Molnar1e642812015-09-05 08:58:10 +02001185 Enabling this option increases the complexity of the kernel
1186 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001187
Ingo Molnar1e642812015-09-05 08:58:10 +02001188 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001189
1190config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001191 bool
1192 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001193
1194config X86_16BIT
1195 bool "Enable support for 16-bit segments" if EXPERT
1196 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001197 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001198 ---help---
1199 This option is required by programs like Wine to run 16-bit
1200 protected mode legacy code on x86 processors. Disabling
1201 this option saves about 300 bytes on i386, or around 6K text
1202 plus 16K runtime memory on x86-64,
1203
1204config X86_ESPFIX32
1205 def_bool y
1206 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001207
H. Peter Anvin197725d2014-05-04 10:00:49 -07001208config X86_ESPFIX64
1209 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001210 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001211
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001212config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001213 bool "Enable vsyscall emulation" if EXPERT
1214 default y
1215 depends on X86_64
1216 ---help---
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001217 This enables emulation of the legacy vsyscall page. Disabling
1218 it is roughly equivalent to booting with vsyscall=none, except
1219 that it will also disable the helpful warning if a program
1220 tries to use a vsyscall. With this option set to N, offending
1221 programs will just segfault, citing addresses of the form
1222 0xffffffffff600?00.
1223
1224 This option is required by many programs built before 2013, and
1225 care should be used even with newer programs if set to N.
1226
1227 Disabling this option saves about 7K of kernel size and
1228 possibly 4K of additional runtime pagetable memory.
1229
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001230config X86_IOPL_IOPERM
1231 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001232 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001233 ---help---
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001234 This enables the ioperm() and iopl() syscalls which are necessary
1235 for legacy applications.
1236
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001237 Legacy IOPL support is an overbroad mechanism which allows user
1238 space aside of accessing all 65536 I/O ports also to disable
1239 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1240 capabilities and permission from potentially active security
1241 modules.
1242
1243 The emulation restricts the functionality of the syscall to
1244 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001245 ability to disable interrupts from user space which would be
1246 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001247
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001248config TOSHIBA
1249 tristate "Toshiba Laptop support"
1250 depends on X86_32
1251 ---help---
1252 This adds a driver to safely access the System Management Mode of
1253 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254 not work on models with a Phoenix BIOS. The System Management Mode
1255 is used to set the BIOS and power saving options on Toshiba portables.
1256
1257 For information on utilities to make use of this driver see the
1258 Toshiba Linux utilities web site at:
1259 <http://www.buzzard.org.uk/toshiba/>.
1260
1261 Say Y if you intend to run this kernel on a Toshiba portable.
1262 Say N otherwise.
1263
1264config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001265 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001266 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001267 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001268 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001269 This option enables legacy /proc/i8k userspace interface in hwmon
1270 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1271 temperature and allows controlling fan speeds of Dell laptops via
1272 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1273 it reports also power and hotkey status. For fan speed control is
1274 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001275
Pali Rohár039ae582015-05-14 13:16:37 +02001276 Say Y if you intend to run this kernel on old Dell laptops or want to
1277 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001278 Say N otherwise.
1279
1280config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001281 bool "Enable X86 board specific fixups for reboot"
1282 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001283 ---help---
1284 This enables chipset and/or board specific fixups to be done
1285 in order to get reboot to work correctly. This is only needed on
1286 some combinations of hardware and BIOS. The symptom, for which
1287 this config is intended, is when reboot ends with a stalled/hung
1288 system.
1289
1290 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001291 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001292
1293 Say Y if you want to enable the fixup. Currently, it's safe to
1294 enable this option even if you don't need it.
1295 Say N otherwise.
1296
1297config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001298 bool "CPU microcode loading support"
1299 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001300 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001301 select FW_LOADER
1302 ---help---
1303 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001304 Intel and AMD processors. The Intel support is for the IA32 family,
1305 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1306 AMD support is for families 0x10 and later. You will obviously need
1307 the actual microcode binary data itself which is not shipped with
1308 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001309
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001310 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001311 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001312 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1313 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001314
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001315 In addition, you can build the microcode into the kernel. For that you
1316 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1317 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001318
Peter Oruba8d86f392008-07-28 18:44:21 +02001319config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001320 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001321 depends on MICROCODE
1322 default MICROCODE
1323 select FW_LOADER
1324 ---help---
1325 This options enables microcode patch loading support for Intel
1326 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001327
Alanb8989db2014-01-20 18:01:56 +00001328 For the current Intel microcode data package go to
1329 <https://downloadcenter.intel.com> and search for
1330 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001331
Peter Oruba80cc9f12008-07-28 18:44:22 +02001332config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001333 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001334 depends on MICROCODE
1335 select FW_LOADER
1336 ---help---
1337 If you select this option, microcode patch loading support for AMD
1338 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001339
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001340config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001341 bool "Ancient loading interface (DEPRECATED)"
1342 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001343 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001344 ---help---
1345 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1346 which was used by userspace tools like iucode_tool and microcode.ctl.
1347 It is inadequate because it runs too late to be able to properly
1348 load microcode on a machine and it needs special tools. Instead, you
1349 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001350 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001351
1352config X86_MSR
1353 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001354 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001355 This device gives privileged processes access to the x86
1356 Model-Specific Registers (MSRs). It is a character device with
1357 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358 MSR accesses are directed to a specific CPU on multi-processor
1359 systems.
1360
1361config X86_CPUID
1362 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001363 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001364 This device gives processes access to the x86 CPUID instruction to
1365 be executed on a specific processor. It is a character device
1366 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367 /dev/cpu/31/cpuid.
1368
1369choice
1370 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001371 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001372 depends on X86_32
1373
1374config NOHIGHMEM
1375 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001376 ---help---
1377 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378 However, the address space of 32-bit x86 processors is only 4
1379 Gigabytes large. That means that, if you have a large amount of
1380 physical memory, not all of it can be "permanently mapped" by the
1381 kernel. The physical memory that's not permanently mapped is called
1382 "high memory".
1383
1384 If you are compiling a kernel which will never run on a machine with
1385 more than 1 Gigabyte total physical RAM, answer "off" here (default
1386 choice and suitable for most users). This will result in a "3GB/1GB"
1387 split: 3GB are mapped so that each process sees a 3GB virtual memory
1388 space and the remaining part of the 4GB virtual memory space is used
1389 by the kernel to permanently map as much physical memory as
1390 possible.
1391
1392 If the machine has between 1 and 4 Gigabytes physical RAM, then
1393 answer "4GB" here.
1394
1395 If more than 4 Gigabytes is used then answer "64GB" here. This
1396 selection turns Intel PAE (Physical Address Extension) mode on.
1397 PAE implements 3-level paging on IA32 processors. PAE is fully
1398 supported by Linux, PAE mode is implemented on all recent Intel
1399 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400 then the kernel will not boot on CPUs that don't support PAE!
1401
1402 The actual amount of total physical memory will either be
1403 auto detected or can be forced by using a kernel command line option
1404 such as "mem=256M". (Try "man bootparam" or see the documentation of
1405 your boot loader (lilo or loadlin) about how to pass options to the
1406 kernel at boot time.)
1407
1408 If unsure, say "off".
1409
1410config HIGHMEM4G
1411 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001412 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001413 Select this if you have a 32-bit processor and between 1 and 4
1414 gigabytes of physical RAM.
1415
1416config HIGHMEM64G
1417 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001418 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001419 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001420 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001421 Select this if you have a 32-bit processor and more than 4
1422 gigabytes of physical RAM.
1423
1424endchoice
1425
1426choice
David Rientjes6a108a12011-01-20 14:44:16 -08001427 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001428 default VMSPLIT_3G
1429 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001430 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001431 Select the desired split between kernel and user memory.
1432
1433 If the address range available to the kernel is less than the
1434 physical memory installed, the remaining memory will be available
1435 as "high memory". Accessing high memory is a little more costly
1436 than low memory, as it needs to be mapped into the kernel first.
1437 Note that increasing the kernel address space limits the range
1438 available to user programs, making the address space there
1439 tighter. Selecting anything other than the default 3G/1G split
1440 will also likely make your kernel incompatible with binary-only
1441 kernel modules.
1442
1443 If you are not absolutely sure what you are doing, leave this
1444 option alone!
1445
1446 config VMSPLIT_3G
1447 bool "3G/1G user/kernel split"
1448 config VMSPLIT_3G_OPT
1449 depends on !X86_PAE
1450 bool "3G/1G user/kernel split (for full 1G low memory)"
1451 config VMSPLIT_2G
1452 bool "2G/2G user/kernel split"
1453 config VMSPLIT_2G_OPT
1454 depends on !X86_PAE
1455 bool "2G/2G user/kernel split (for full 2G low memory)"
1456 config VMSPLIT_1G
1457 bool "1G/3G user/kernel split"
1458endchoice
1459
1460config PAGE_OFFSET
1461 hex
1462 default 0xB0000000 if VMSPLIT_3G_OPT
1463 default 0x80000000 if VMSPLIT_2G
1464 default 0x78000000 if VMSPLIT_2G_OPT
1465 default 0x40000000 if VMSPLIT_1G
1466 default 0xC0000000
1467 depends on X86_32
1468
1469config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001470 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001471 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001472
1473config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001474 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001475 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001476 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001477 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001478 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001479 PAE is required for NX support, and furthermore enables
1480 larger swapspace support for non-overcommit purposes. It
1481 has the cost of more pagetable lookup overhead, and also
1482 consumes more pagetable space per process.
1483
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001484config X86_5LEVEL
1485 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001486 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001487 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001488 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001489 depends on X86_64
1490 ---help---
1491 5-level paging enables access to larger address space:
1492 upto 128 PiB of virtual address space and 4 PiB of
1493 physical address space.
1494
1495 It will be supported by future Intel CPUs.
1496
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001497 A kernel with the option enabled can be booted on machines that
1498 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001499
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001500 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001501 information.
1502
1503 Say N if unsure.
1504
Ingo Molnar10971ab2015-03-05 08:18:23 +01001505config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001506 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001507 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001508 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001509 Certain kernel features effectively disable kernel
1510 linear 1 GB mappings (even if the CPU otherwise
1511 supports them), so don't confuse the user by printing
1512 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001513
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001514config X86_CPA_STATISTICS
1515 bool "Enable statistic for Change Page Attribute"
1516 depends on DEBUG_FS
1517 ---help---
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001518 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001519 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001520 page mappings when mapping protections are changed.
1521
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001522config AMD_MEM_ENCRYPT
1523 bool "AMD Secure Memory Encryption (SME) support"
1524 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001525 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001526 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001527 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001528 ---help---
1529 Say yes to enable support for the encryption of system memory.
1530 This requires an AMD processor that supports Secure Memory
1531 Encryption (SME).
1532
1533config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1534 bool "Activate AMD Secure Memory Encryption (SME) by default"
1535 default y
1536 depends on AMD_MEM_ENCRYPT
1537 ---help---
1538 Say yes to have system memory encrypted by default if running on
1539 an AMD processor that supports Secure Memory Encryption (SME).
1540
1541 If set to Y, then the encryption of system memory can be
1542 deactivated with the mem_encrypt=off command line option.
1543
1544 If set to N, then the encryption of system memory can be
1545 activated with the mem_encrypt=on command line option.
1546
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001547# Common NUMA Features
1548config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001549 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001550 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001551 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1552 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001553 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -08001554 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001555
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001556 The kernel will try to allocate memory used by a CPU on the
1557 local memory controller of the CPU and add some more
1558 NUMA awareness to the kernel.
1559
Ingo Molnarc280ea52008-11-08 13:29:45 +01001560 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001561 (or later), AMD Opteron, or EM64T NUMA.
1562
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001563 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001564 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001565
1566 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001567
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001568config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001569 def_bool y
1570 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001571 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001572 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001573 Enable AMD NUMA node topology detection. You should say Y here if
1574 you have a multi processor AMD system. This uses an old method to
1575 read the NUMA configuration directly from the builtin Northbridge
1576 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1577 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001578
1579config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001580 def_bool y
1581 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001582 depends on X86_64 && NUMA && ACPI && PCI
1583 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001584 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001585 Enable ACPI SRAT based node topology detection.
1586
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001587# Some NUMA nodes have memory ranges that span
1588# other nodes. Even though a pfn is valid and
1589# between a node's start and end pfns, it may not
1590# reside on that node. See memmap_init_zone()
1591# for details.
1592config NODES_SPAN_OTHER_NODES
1593 def_bool y
1594 depends on X86_64_ACPI_NUMA
1595
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001596config NUMA_EMU
1597 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001598 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001599 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001600 Enable NUMA emulation. A flat machine will be split
1601 into virtual nodes when booted with "numa=fake=N", where N is the
1602 number of nodes. This is only useful for debugging.
1603
1604config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001605 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001606 range 1 10
1607 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001608 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001609 default "3"
1610 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001611 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001612 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001613 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001614
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001616 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001617 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001618
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001619config ARCH_FLATMEM_ENABLE
1620 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001621 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001622
1623config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001624 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001625 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001626 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001627
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001628config ARCH_SPARSEMEM_ENABLE
1629 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001630 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001631 select SPARSEMEM_STATIC if X86_32
1632 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1633
Tejun Heo3b166512011-04-01 11:15:12 +02001634config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001635 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001636
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001637config ARCH_SELECT_MEMORY_MODEL
1638 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001639 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001640
1641config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001642 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001643 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001644 help
1645 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001646 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001647 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001648
Tejun Heo3b166512011-04-01 11:15:12 +02001649config ARCH_PROC_KCORE_TEXT
1650 def_bool y
1651 depends on X86_64 && PROC_KCORE
1652
Avi Kivitya29815a2010-01-10 16:28:09 +02001653config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001654 hex
1655 default 0 if X86_32
1656 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001657
Dan Williams7a678322015-08-19 00:34:34 -04001658config X86_PMEM_LEGACY_DEVICE
1659 bool
1660
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001661config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001662 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001663 depends on PHYS_ADDR_T_64BIT
1664 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001665 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001666 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001667 help
1668 Treat memory marked using the non-standard e820 type of 12 as used
1669 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1670 The kernel will offer these regions to the 'pmem' driver so
1671 they can be used for persistent storage.
1672
1673 Say Y if unsure.
1674
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001675config HIGHPTE
1676 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001677 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001678 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001679 The VM uses one page table entry for each page of physical memory.
1680 For systems with a lot of RAM, this can be wasteful of precious
1681 low memory. Setting this option will put user-space page table
1682 entries in high memory.
1683
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001684config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001685 bool "Check for low memory corruption"
1686 ---help---
1687 Periodically check for memory corruption in low memory, which
1688 is suspected to be caused by BIOS. Even when enabled in the
1689 configuration, it is disabled at runtime. Enable it by
1690 setting "memory_corruption_check=1" on the kernel command
1691 line. By default it scans the low 64k of memory every 60
1692 seconds; see the memory_corruption_check_size and
1693 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001694 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001695
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001696 When enabled with the default parameters, this option has
1697 almost no overhead, as it reserves a relatively small amount
1698 of memory and scans it infrequently. It both detects corruption
1699 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001700
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001701 It is, however, intended as a diagnostic tool; if repeatable
1702 BIOS-originated corruption always affects the same memory,
1703 you can use memmap= to prevent the kernel from using that
1704 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001705
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001706config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001707 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001708 depends on X86_CHECK_BIOS_CORRUPTION
1709 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001710 ---help---
1711 Set whether the default state of memory_corruption_check is
1712 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001713
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001714config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001715 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1716 default 64
1717 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001718 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001719 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001720
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001721 The first page contains BIOS data structures that the kernel
1722 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001723
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001724 By default we reserve the first 64K of physical RAM, as a
1725 number of BIOSes are known to corrupt that memory range
1726 during events such as suspend/resume or monitor cable
1727 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001728
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001729 You can set this to 4 if you are absolutely sure that you
1730 trust the BIOS to get all its memory reservations and usages
1731 right. If you know your BIOS have problems beyond the
1732 default 64K area, you can set this to 640 to avoid using the
1733 entire low memory range.
1734
1735 If you have doubts about the BIOS (e.g. suspend/resume does
1736 not work or there's kernel crashes after certain hardware
1737 hotplug events) then you might want to enable
1738 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1739 typical corruption patterns.
1740
1741 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001742
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001743config MATH_EMULATION
1744 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001745 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001746 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001747 ---help---
1748 Linux can emulate a math coprocessor (used for floating point
1749 operations) if you don't have one. 486DX and Pentium processors have
1750 a math coprocessor built in, 486SX and 386 do not, unless you added
1751 a 487DX or 387, respectively. (The messages during boot time can
1752 give you some hints here ["man dmesg"].) Everyone needs either a
1753 coprocessor or this emulation.
1754
1755 If you don't have a math coprocessor, you need to say Y here; if you
1756 say Y here even though you have a coprocessor, the coprocessor will
1757 be used nevertheless. (This behavior can be changed with the kernel
1758 command line option "no387", which comes handy if your coprocessor
1759 is broken. Try "man bootparam" or see the documentation of your boot
1760 loader (lilo or loadlin) about how to pass options to the kernel at
1761 boot time.) This means that it is a good idea to say Y here if you
1762 intend to use this kernel on different machines.
1763
1764 More information about the internals of the Linux math coprocessor
1765 emulation can be found in <file:arch/x86/math-emu/README>.
1766
1767 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1768 kernel, it won't hurt.
1769
1770config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001771 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001772 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001773 ---help---
1774 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1775 the Memory Type Range Registers (MTRRs) may be used to control
1776 processor access to memory ranges. This is most useful if you have
1777 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1778 allows bus write transfers to be combined into a larger transfer
1779 before bursting over the PCI/AGP bus. This can increase performance
1780 of image write operations 2.5 times or more. Saying Y here creates a
1781 /proc/mtrr file which may be used to manipulate your processor's
1782 MTRRs. Typically the X server should use this.
1783
1784 This code has a reasonably generic interface so that similar
1785 control registers on other processors can be easily supported
1786 as well:
1787
1788 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1789 Registers (ARRs) which provide a similar functionality to MTRRs. For
1790 these, the ARRs are used to emulate the MTRRs.
1791 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1792 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1793 write-combining. All of these processors are supported by this code
1794 and it makes sense to say Y here if you have one of them.
1795
1796 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1797 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1798 can lead to all sorts of problems, so it's good to say Y here.
1799
1800 You can safely say Y even if your machine doesn't have MTRRs, you'll
1801 just add about 9 KB to your kernel.
1802
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001803 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001804
Yinghai Lu95ffa242008-04-29 03:52:33 -07001805config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001806 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001807 prompt "MTRR cleanup support"
1808 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001809 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001810 Convert MTRR layout from continuous to discrete, so X drivers can
1811 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001812
Thomas Gleixneraba37282008-07-15 14:48:48 +02001813 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001814 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001815 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001816
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001817 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001818
1819config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001820 int "MTRR cleanup enable value (0-1)"
1821 range 0 1
1822 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001823 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001824 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001825 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001826
Yinghai Lu12031a62008-05-02 02:40:22 -07001827config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1828 int "MTRR cleanup spare reg num (0-7)"
1829 range 0 7
1830 default "1"
1831 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001832 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001833 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001834 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001835
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001836config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001837 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001838 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001839 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001840 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001841 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001842
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001843 PATs are the modern equivalents of MTRRs and are much more
1844 flexible than MTRRs.
1845
1846 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001847 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001848
1849 If unsure, say Y.
1850
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001851config ARCH_USES_PG_UNCACHED
1852 def_bool y
1853 depends on X86_PAT
1854
H. Peter Anvin628c6242011-07-31 13:59:29 -07001855config ARCH_RANDOM
1856 def_bool y
1857 prompt "x86 architectural random number generator" if EXPERT
1858 ---help---
1859 Enable the x86 architectural RDRAND instruction
1860 (Intel Bull Mountain technology) to generate random numbers.
1861 If supported, this is a high bandwidth, cryptographically
1862 secure hardware random number generator.
1863
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001864config X86_SMAP
1865 def_bool y
1866 prompt "Supervisor Mode Access Prevention" if EXPERT
1867 ---help---
1868 Supervisor Mode Access Prevention (SMAP) is a security
1869 feature in newer Intel processors. There is a small
1870 performance cost if this enabled and turned on; there is
1871 also a small increase in the kernel size if this is enabled.
1872
1873 If unsure, say Y.
1874
Babu Mogerb9718802019-11-05 21:25:32 +00001875config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001876 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001877 depends on CPU_SUP_INTEL || CPU_SUP_AMD
1878 prompt "User Mode Instruction Prevention" if EXPERT
Ricardo Neriaa35f892017-11-05 18:27:54 -08001879 ---help---
Babu Mogerb9718802019-11-05 21:25:32 +00001880 User Mode Instruction Prevention (UMIP) is a security feature in
1881 some x86 processors. If enabled, a general protection fault is
1882 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1883 executed in user mode. These instructions unnecessarily expose
1884 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001885
1886 The vast majority of applications do not use these instructions.
1887 For the very few that do, software emulation is provided in
1888 specific cases in protected and virtual-8086 modes. Emulated
1889 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001890
Dave Hansen35e97792016-02-12 13:02:00 -08001891config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001892 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001893 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001894 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001895 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001896 select ARCH_USES_HIGH_VMA_FLAGS
1897 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001898 ---help---
1899 Memory Protection Keys provides a mechanism for enforcing
1900 page-based protections, but without requiring modification of the
1901 page tables when an application changes protection domains.
1902
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001903 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001904
1905 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001906
Michal Hockodb616172019-10-23 12:35:50 +02001907choice
1908 prompt "TSX enable mode"
1909 depends on CPU_SUP_INTEL
1910 default X86_INTEL_TSX_MODE_OFF
1911 help
1912 Intel's TSX (Transactional Synchronization Extensions) feature
1913 allows to optimize locking protocols through lock elision which
1914 can lead to a noticeable performance boost.
1915
1916 On the other hand it has been shown that TSX can be exploited
1917 to form side channel attacks (e.g. TAA) and chances are there
1918 will be more of those attacks discovered in the future.
1919
1920 Therefore TSX is not enabled by default (aka tsx=off). An admin
1921 might override this decision by tsx=on the command line parameter.
1922 Even with TSX enabled, the kernel will attempt to enable the best
1923 possible TAA mitigation setting depending on the microcode available
1924 for the particular machine.
1925
1926 This option allows to set the default tsx mode between tsx=on, =off
1927 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1928 details.
1929
1930 Say off if not sure, auto if TSX is in use but it should be used on safe
1931 platforms or on if TSX is in use and the security aspect of tsx is not
1932 relevant.
1933
1934config X86_INTEL_TSX_MODE_OFF
1935 bool "off"
1936 help
1937 TSX is disabled if possible - equals to tsx=off command line parameter.
1938
1939config X86_INTEL_TSX_MODE_ON
1940 bool "on"
1941 help
1942 TSX is always enabled on TSX capable HW - equals the tsx=on command
1943 line parameter.
1944
1945config X86_INTEL_TSX_MODE_AUTO
1946 bool "auto"
1947 help
1948 TSX is enabled on TSX capable HW that is believed to be safe against
1949 side channel attacks- equals the tsx=auto command line parameter.
1950endchoice
1951
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001952config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001953 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001954 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001955 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001956 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001957 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001958 This enables the kernel to use EFI runtime services that are
1959 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001960
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001961 This option is only useful on systems that have EFI firmware.
1962 In addition, you should use the latest ELILO loader available
1963 at <http://elilo.sourceforge.net> in order to take advantage
1964 of EFI runtime services. However, even with this option, the
1965 resultant kernel should continue to boot on existing non-EFI
1966 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001967
Matt Fleming291f3632011-12-12 21:27:52 +00001968config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001969 bool "EFI stub support"
1970 depends on EFI && !X86_USE_3DNOW
1971 depends on $(cc-option,-mabi=ms) || X86_32
1972 select RELOCATABLE
1973 ---help---
1974 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001975 by EFI firmware without the use of a bootloader.
1976
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001977 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001978
Matt Fleming7d453ee2014-01-10 18:52:06 +00001979config EFI_MIXED
1980 bool "EFI mixed-mode support"
1981 depends on EFI_STUB && X86_64
1982 ---help---
1983 Enabling this feature allows a 64-bit kernel to be booted
1984 on a 32-bit firmware, provided that your CPU supports 64-bit
1985 mode.
1986
1987 Note that it is not possible to boot a mixed-mode enabled
1988 kernel via the EFI boot stub - a bootloader that supports
1989 the EFI handover protocol must be used.
1990
1991 If unsure, say N.
1992
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001993config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001994 def_bool y
1995 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001996 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001997 This kernel feature is useful for number crunching applications
1998 that may need to compute untrusted bytecode during their
1999 execution. By using pipes or other transports made available to
2000 the process as file descriptors supporting the read/write
2001 syscalls, it's possible to isolate those applications in
2002 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04002003 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002004 and the task is only allowed to execute a few safe syscalls
2005 defined by each seccomp mode.
2006
2007 If unsure, say Y. Only embedded should say N here.
2008
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002009source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002010
2011config KEXEC
2012 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07002013 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002014 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002015 kexec is a system call that implements the ability to shutdown your
2016 current kernel, and to start another kernel. It is like a reboot
2017 but it is independent of the system firmware. And like a reboot
2018 you can start any kernel with it, not just Linux.
2019
2020 The name comes from the similarity to the exec system call.
2021
2022 It is an ongoing process to be certain the hardware in a machine
2023 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002024 initially work for you. As of this writing the exact hardware
2025 interface is strongly in flux, so no good recommendation can be
2026 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002027
Vivek Goyal74ca3172014-08-29 15:18:46 -07002028config KEXEC_FILE
2029 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002030 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002031 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002032 depends on X86_64
2033 depends on CRYPTO=y
2034 depends on CRYPTO_SHA256=y
2035 ---help---
2036 This is new version of kexec system call. This system call is
2037 file based and takes file descriptors as system call argument
2038 for kernel and initramfs as opposed to list of segments as
2039 accepted by previous system call.
2040
AKASHI Takahirob799a092018-04-13 15:35:45 -07002041config ARCH_HAS_KEXEC_PURGATORY
2042 def_bool KEXEC_FILE
2043
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002044config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002045 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002046 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002047 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002048
2049 This option makes the kexec_file_load() syscall check for a valid
2050 signature of the kernel image. The image can still be loaded without
2051 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2052 there's a signature that we can check, then it must be valid.
2053
2054 In addition to this option, you need to enable signature
2055 verification for the corresponding kernel image type being
2056 loaded in order for this to work.
2057
2058config KEXEC_SIG_FORCE
2059 bool "Require a valid signature in kexec_file_load() syscall"
2060 depends on KEXEC_SIG
2061 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002062 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002063 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002064
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002065config KEXEC_BZIMAGE_VERIFY_SIG
2066 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002067 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002068 depends on SIGNED_PE_FILE_VERIFICATION
2069 select SYSTEM_TRUSTED_KEYRING
2070 ---help---
2071 Enable bzImage signature verification support.
2072
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002073config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002074 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002075 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002076 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002077 Generate crash dump after being started by kexec.
2078 This should be normally only set in special crash dump kernels
2079 which are loaded in the main kernel with kexec-tools into
2080 a specially reserved region and then later executed after
2081 a crash by kdump/kexec. The crash dump kernel must be compiled
2082 to a memory address not used by the main kernel or BIOS using
2083 PHYSICAL_START, or it must be built as a relocatable image
2084 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002085 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002086
Huang Ying3ab83522008-07-25 19:45:07 -07002087config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002088 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002089 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002090 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002091 Jump between original kernel and kexeced kernel and invoke
2092 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002093
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002094config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002095 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002096 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002097 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002098 This gives the physical address where the kernel is loaded.
2099
2100 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2101 bzImage will decompress itself to above physical address and
2102 run from there. Otherwise, bzImage will run from the address where
2103 it has been loaded by the boot loader and will ignore above physical
2104 address.
2105
2106 In normal kdump cases one does not have to set/change this option
2107 as now bzImage can be compiled as a completely relocatable image
2108 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2109 address. This option is mainly useful for the folks who don't want
2110 to use a bzImage for capturing the crash dump and want to use a
2111 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2112 to be specifically compiled to run from a specific memory area
2113 (normally a reserved region) and this option comes handy.
2114
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002115 So if you are using bzImage for capturing the crash dump,
2116 leave the value here unchanged to 0x1000000 and set
2117 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2118 for capturing the crash dump change this value to start of
2119 the reserved region. In other words, it can be set based on
2120 the "X" value as specified in the "crashkernel=YM@XM"
2121 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002122 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002123 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002124
2125 Usage of bzImage for capturing the crash dump is recommended as
2126 one does not have to build two kernels. Same kernel can be used
2127 as production kernel and capture kernel. Above option should have
2128 gone away after relocatable bzImage support is introduced. But it
2129 is present because there are users out there who continue to use
2130 vmlinux for dump capture. This option should go away down the
2131 line.
2132
2133 Don't change this unless you know what you are doing.
2134
2135config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002136 bool "Build a relocatable kernel"
2137 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002138 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002139 This builds a kernel image that retains relocation information
2140 so it can be loaded someplace besides the default 1MB.
2141 The relocations tend to make the kernel binary about 10% larger,
2142 but are discarded at runtime.
2143
2144 One use is for the kexec on panic case where the recovery kernel
2145 must live at a different physical address than the primary
2146 kernel.
2147
2148 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2149 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002150 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002151
Kees Cook8ab38202013-10-10 17:18:14 -07002152config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002153 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002154 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002155 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002156 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002157 In support of Kernel Address Space Layout Randomization (KASLR),
2158 this randomizes the physical address at which the kernel image
2159 is decompressed and the virtual address where the kernel
2160 image is mapped, as a security feature that deters exploit
2161 attempts relying on knowledge of the location of kernel
2162 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002163
Kees Cooked9f0072016-05-25 15:45:33 -07002164 On 64-bit, the kernel physical and virtual addresses are
2165 randomized separately. The physical address will be anywhere
2166 between 16MB and the top of physical memory (up to 64TB). The
2167 virtual address will be randomized from 16MB up to 1GB (9 bits
2168 of entropy). Note that this also reduces the memory space
2169 available to kernel modules from 1.5GB to 1GB.
2170
2171 On 32-bit, the kernel physical and virtual addresses are
2172 randomized together. They will be randomized from 16MB up to
2173 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002174
Baoquan Hee8581e32016-04-20 13:55:43 -07002175 Entropy is generated using the RDRAND instruction if it is
2176 supported. If RDTSC is supported, its value is mixed into
2177 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002178 supported, then entropy is read from the i8254 timer. The
2179 usable entropy is limited by the kernel being built using
2180 2GB addressing, and that PHYSICAL_ALIGN must be at a
2181 minimum of 2MB. As a result, only 10 bits of entropy are
2182 theoretically possible, but the implementations are further
2183 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002184
Ingo Molnar6807c842017-04-18 11:08:12 +02002185 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002186
2187# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002188config X86_NEED_RELOCS
2189 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002190 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002191
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002192config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002193 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002194 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002195 range 0x2000 0x1000000 if X86_32
2196 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002197 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002198 This value puts the alignment restrictions on physical address
2199 where kernel is loaded and run from. Kernel is compiled for an
2200 address which meets above alignment restriction.
2201
2202 If bootloader loads the kernel at a non-aligned address and
2203 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2204 address aligned to above value and run from there.
2205
2206 If bootloader loads the kernel at a non-aligned address and
2207 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2208 load address and decompress itself to the address it has been
2209 compiled for and run from there. The address for which kernel is
2210 compiled already meets above alignment restrictions. Hence the
2211 end result is that kernel runs from a physical address meeting
2212 above alignment restrictions.
2213
Kees Cooka0215062013-07-08 09:15:17 -07002214 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2215 this value must be a multiple of 0x200000.
2216
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002217 Don't change this unless you know what you are doing.
2218
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002219config DYNAMIC_MEMORY_LAYOUT
2220 bool
2221 ---help---
2222 This option makes base addresses of vmalloc and vmemmap as well as
2223 __PAGE_OFFSET movable during boot.
2224
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002225config RANDOMIZE_MEMORY
2226 bool "Randomize the kernel memory sections"
2227 depends on X86_64
2228 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002229 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002230 default RANDOMIZE_BASE
2231 ---help---
2232 Randomizes the base virtual address of kernel memory sections
2233 (physical memory mapping, vmalloc & vmemmap). This security feature
2234 makes exploits relying on predictable memory locations less reliable.
2235
2236 The order of allocations remains unchanged. Entropy is generated in
2237 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2238 configuration have in average 30,000 different possible virtual
2239 addresses for each memory section.
2240
Ingo Molnar6807c842017-04-18 11:08:12 +02002241 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002242
Thomas Garnier90397a42016-06-21 17:47:06 -07002243config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2244 hex "Physical memory mapping padding" if EXPERT
2245 depends on RANDOMIZE_MEMORY
2246 default "0xa" if MEMORY_HOTPLUG
2247 default "0x0"
2248 range 0x1 0x40 if MEMORY_HOTPLUG
2249 range 0x0 0x40
2250 ---help---
2251 Define the padding in terabytes added to the existing physical
2252 memory size during kernel memory randomization. It is useful
2253 for memory hotplug support but reduces the entropy available for
2254 address randomization.
2255
2256 If unsure, leave at the default value.
2257
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002258config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002259 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002260 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002261
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002262config BOOTPARAM_HOTPLUG_CPU0
2263 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002264 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002265 ---help---
2266 Set whether default state of cpu0_hotpluggable is on or off.
2267
2268 Say Y here to enable CPU0 hotplug by default. If this switch
2269 is turned on, there is no need to give cpu0_hotplug kernel
2270 parameter and the CPU0 hotplug feature is enabled by default.
2271
2272 Please note: there are two known CPU0 dependencies if you want
2273 to enable the CPU0 hotplug feature either by this switch or by
2274 cpu0_hotplug kernel parameter.
2275
2276 First, resume from hibernate or suspend always starts from CPU0.
2277 So hibernate and suspend are prevented if CPU0 is offline.
2278
2279 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2280 offline if any interrupt can not migrate out of CPU0. There may
2281 be other CPU0 dependencies.
2282
2283 Please make sure the dependencies are under your control before
2284 you enable this feature.
2285
2286 Say N if you don't want to enable CPU0 hotplug feature by default.
2287 You still can enable the CPU0 hotplug feature at boot by kernel
2288 parameter cpu0_hotplug.
2289
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002290config DEBUG_HOTPLUG_CPU0
2291 def_bool n
2292 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002293 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002294 ---help---
2295 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2296 soon as possible and boots up userspace with CPU0 offlined. User
2297 can online CPU0 back after boot time.
2298
2299 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2300 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2301 compilation or giving cpu0_hotplug kernel parameter at boot.
2302
2303 If unsure, say N.
2304
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002305config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002306 def_bool n
2307 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002308 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002309 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002310 Certain buggy versions of glibc will crash if they are
2311 presented with a 32-bit vDSO that is not mapped at the address
2312 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002313
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002314 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2315 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2316 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2317 the only released version with the bug, but OpenSUSE 9
2318 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002319
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002320 The symptom of the bug is that everything crashes on startup, saying:
2321 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2322
2323 Saying Y here changes the default value of the vdso32 boot
2324 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2325 This works around the glibc bug but hurts performance.
2326
2327 If unsure, say N: if you are compiling your own kernel, you
2328 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002329
Kees Cook3dc33bd2015-08-12 17:55:19 -07002330choice
2331 prompt "vsyscall table for legacy applications"
2332 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002333 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002334 help
2335 Legacy user code that does not know how to find the vDSO expects
2336 to be able to issue three syscalls by calling fixed addresses in
2337 kernel space. Since this location is not randomized with ASLR,
2338 it can be used to assist security vulnerability exploitation.
2339
2340 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002341 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002342
2343 On a system with recent enough glibc (2.14 or newer) and no
2344 static binaries, you can say None without a performance penalty
2345 to improve security.
2346
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002347 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002348
Kees Cook3dc33bd2015-08-12 17:55:19 -07002349 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002350 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002351 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002352 The kernel traps and emulates calls into the fixed vsyscall
2353 address mapping. This makes the mapping non-executable, but
2354 it still contains readable known contents, which could be
2355 used in certain rare security vulnerability exploits. This
2356 configuration is recommended when using legacy userspace
2357 that still uses vsyscalls along with legacy binary
2358 instrumentation tools that require code to be readable.
2359
2360 An example of this type of legacy userspace is running
2361 Pin on an old binary that still uses vsyscalls.
2362
2363 config LEGACY_VSYSCALL_XONLY
2364 bool "Emulate execution only"
2365 help
2366 The kernel traps and emulates calls into the fixed vsyscall
2367 address mapping and does not allow reads. This
2368 configuration is recommended when userspace might use the
2369 legacy vsyscall area but support for legacy binary
2370 instrumentation of legacy code is not needed. It mitigates
2371 certain uses of the vsyscall area as an ASLR-bypassing
2372 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002373
2374 config LEGACY_VSYSCALL_NONE
2375 bool "None"
2376 help
2377 There will be no vsyscall mapping at all. This will
2378 eliminate any risk of ASLR bypass due to the vsyscall
2379 fixed address mapping. Attempts to use the vsyscalls
2380 will be reported to dmesg, so that either old or
2381 malicious userspace programs can be identified.
2382
2383endchoice
2384
Tim Bird516cbf32008-08-12 12:52:36 -07002385config CMDLINE_BOOL
2386 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002387 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002388 Allow for specifying boot arguments to the kernel at
2389 build time. On some systems (e.g. embedded ones), it is
2390 necessary or convenient to provide some or all of the
2391 kernel boot arguments with the kernel itself (that is,
2392 to not rely on the boot loader to provide them.)
2393
2394 To compile command line arguments into the kernel,
2395 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002396 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002397
2398 Systems with fully functional boot loaders (i.e. non-embedded)
2399 should leave this option set to 'N'.
2400
2401config CMDLINE
2402 string "Built-in kernel command string"
2403 depends on CMDLINE_BOOL
2404 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002405 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002406 Enter arguments here that should be compiled into the kernel
2407 image and used at boot time. If the boot loader provides a
2408 command line at boot time, it is appended to this string to
2409 form the full kernel command line, when the system boots.
2410
2411 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2412 change this behavior.
2413
2414 In most cases, the command line (whether built-in or provided
2415 by the boot loader) should specify the device for the root
2416 file system.
2417
2418config CMDLINE_OVERRIDE
2419 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002420 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002421 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002422 Set this option to 'Y' to have the kernel ignore the boot loader
2423 command line, and use ONLY the built-in command line.
2424
2425 This is used to work around broken boot loaders. This should
2426 be set to 'N' under normal conditions.
2427
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002428config MODIFY_LDT_SYSCALL
2429 bool "Enable the LDT (local descriptor table)" if EXPERT
2430 default y
2431 ---help---
2432 Linux can allow user programs to install a per-process x86
2433 Local Descriptor Table (LDT) using the modify_ldt(2) system
2434 call. This is required to run 16-bit or segmented code such as
2435 DOSEMU or some Wine programs. It is also used by some very old
2436 threading libraries.
2437
2438 Enabling this feature adds a small amount of overhead to
2439 context switches and increases the low-level kernel attack
2440 surface. Disabling it removes the modify_ldt(2) system call.
2441
2442 Saying 'N' here may make sense for embedded or server kernels.
2443
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002444source "kernel/livepatch/Kconfig"
2445
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002446endmenu
2447
Michal Hocko3072e412017-09-08 16:11:39 -07002448config ARCH_HAS_ADD_PAGES
2449 def_bool y
2450 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2451
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002452config ARCH_ENABLE_MEMORY_HOTPLUG
2453 def_bool y
2454 depends on X86_64 || (X86_32 && HIGHMEM)
2455
Gary Hade35551052008-10-31 10:52:03 -07002456config ARCH_ENABLE_MEMORY_HOTREMOVE
2457 def_bool y
2458 depends on MEMORY_HOTPLUG
2459
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002460config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002461 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002462 depends on NUMA
2463
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002464config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2465 def_bool y
2466 depends on X86_64 || X86_PAE
2467
Naoya Horiguchic177c812014-06-04 16:05:35 -07002468config ARCH_ENABLE_HUGEPAGE_MIGRATION
2469 def_bool y
2470 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2471
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002472config ARCH_ENABLE_THP_MIGRATION
2473 def_bool y
2474 depends on X86_64 && TRANSPARENT_HUGEPAGE
2475
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002476menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002477
2478config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002479 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002480 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002481
2482source "kernel/power/Kconfig"
2483
2484source "drivers/acpi/Kconfig"
2485
Feng Tangefafc8b2009-08-14 15:23:29 -04002486source "drivers/sfi/Kconfig"
2487
Andi Kleena6b68072008-01-30 13:32:49 +01002488config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002489 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002490 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002491
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002492menuconfig APM
2493 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002494 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002495 ---help---
2496 APM is a BIOS specification for saving power using several different
2497 techniques. This is mostly useful for battery powered laptops with
2498 APM compliant BIOSes. If you say Y here, the system time will be
2499 reset after a RESUME operation, the /proc/apm device will provide
2500 battery status information, and user-space programs will receive
2501 notification of APM "events" (e.g. battery status change).
2502
2503 If you select "Y" here, you can disable actual use of the APM
2504 BIOS by passing the "apm=off" option to the kernel at boot time.
2505
2506 Note that the APM support is almost completely disabled for
2507 machines with more than one CPU.
2508
2509 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002510 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002511 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002512 <http://www.tldp.org/docs.html#howto>.
2513
2514 This driver does not spin down disk drives (see the hdparm(8)
2515 manpage ("man 8 hdparm") for that), and it doesn't turn off
2516 VESA-compliant "green" monitors.
2517
2518 This driver does not support the TI 4000M TravelMate and the ACER
2519 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2520 desktop machines also don't have compliant BIOSes, and this driver
2521 may cause those machines to panic during the boot phase.
2522
2523 Generally, if you don't have a battery in your machine, there isn't
2524 much point in using this driver and you should say N. If you get
2525 random kernel OOPSes or reboots that don't seem to be related to
2526 anything, try disabling/enabling this option (or disabling/enabling
2527 APM in your BIOS).
2528
2529 Some other things you should try when experiencing seemingly random,
2530 "weird" problems:
2531
2532 1) make sure that you have enough swap space and that it is
2533 enabled.
2534 2) pass the "no-hlt" option to the kernel
2535 3) switch on floating point emulation in the kernel and pass
2536 the "no387" option to the kernel
2537 4) pass the "floppy=nodma" option to the kernel
2538 5) pass the "mem=4M" option to the kernel (thereby disabling
2539 all but the first 4 MB of RAM)
2540 6) make sure that the CPU is not over clocked.
2541 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2542 8) disable the cache from your BIOS settings
2543 9) install a fan for the video card or exchange video RAM
2544 10) install a better fan for the CPU
2545 11) exchange RAM chips
2546 12) exchange the motherboard.
2547
2548 To compile this driver as a module, choose M here: the
2549 module will be called apm.
2550
2551if APM
2552
2553config APM_IGNORE_USER_SUSPEND
2554 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002555 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002556 This option will ignore USER SUSPEND requests. On machines with a
2557 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2558 series notebooks, it is necessary to say Y because of a BIOS bug.
2559
2560config APM_DO_ENABLE
2561 bool "Enable PM at boot time"
2562 ---help---
2563 Enable APM features at boot time. From page 36 of the APM BIOS
2564 specification: "When disabled, the APM BIOS does not automatically
2565 power manage devices, enter the Standby State, enter the Suspend
2566 State, or take power saving steps in response to CPU Idle calls."
2567 This driver will make CPU Idle calls when Linux is idle (unless this
2568 feature is turned off -- see "Do CPU IDLE calls", below). This
2569 should always save battery power, but more complicated APM features
2570 will be dependent on your BIOS implementation. You may need to turn
2571 this option off if your computer hangs at boot time when using APM
2572 support, or if it beeps continuously instead of suspending. Turn
2573 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2574 T400CDT. This is off by default since most machines do fine without
2575 this feature.
2576
2577config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002578 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002579 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002580 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002581 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2582 On some machines, this can activate improved power savings, such as
2583 a slowed CPU clock rate, when the machine is idle. These idle calls
2584 are made after the idle loop has run for some length of time (e.g.,
2585 333 mS). On some machines, this will cause a hang at boot time or
2586 whenever the CPU becomes idle. (On machines with more than one CPU,
2587 this option does nothing.)
2588
2589config APM_DISPLAY_BLANK
2590 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002591 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002592 Enable console blanking using the APM. Some laptops can use this to
2593 turn off the LCD backlight when the screen blanker of the Linux
2594 virtual console blanks the screen. Note that this is only used by
2595 the virtual console screen blanker, and won't turn off the backlight
2596 when using the X Window system. This also doesn't have anything to
2597 do with your VESA-compliant power-saving monitor. Further, this
2598 option doesn't work for all laptops -- it might not turn off your
2599 backlight at all, or it might print a lot of errors to the console,
2600 especially if you are using gpm.
2601
2602config APM_ALLOW_INTS
2603 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002604 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002605 Normally we disable external interrupts while we are making calls to
2606 the APM BIOS as a measure to lessen the effects of a badly behaving
2607 BIOS implementation. The BIOS should reenable interrupts if it
2608 needs to. Unfortunately, some BIOSes do not -- especially those in
2609 many of the newer IBM Thinkpads. If you experience hangs when you
2610 suspend, try setting this to Y. Otherwise, say N.
2611
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002612endif # APM
2613
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002614source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002615
2616source "drivers/cpuidle/Kconfig"
2617
Andy Henroid27471fd2008-10-09 11:45:22 -07002618source "drivers/idle/Kconfig"
2619
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002620endmenu
2621
2622
2623menu "Bus options (PCI etc.)"
2624
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002625choice
2626 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002627 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002628 default PCI_GOANY
2629 ---help---
2630 On PCI systems, the BIOS can be used to detect the PCI devices and
2631 determine their configuration. However, some old PCI motherboards
2632 have BIOS bugs and may crash if this is done. Also, some embedded
2633 PCI-based systems don't have any BIOS at all. Linux can also try to
2634 detect the PCI hardware directly without using the BIOS.
2635
2636 With this option, you can specify how Linux should detect the
2637 PCI devices. If you choose "BIOS", the BIOS will be used,
2638 if you choose "Direct", the BIOS won't be used, and if you
2639 choose "MMConfig", then PCI Express MMCONFIG will be used.
2640 If you choose "Any", the kernel will try MMCONFIG, then the
2641 direct access method and falls back to the BIOS if that doesn't
2642 work. If unsure, go with the default, which is "Any".
2643
2644config PCI_GOBIOS
2645 bool "BIOS"
2646
2647config PCI_GOMMCONFIG
2648 bool "MMConfig"
2649
2650config PCI_GODIRECT
2651 bool "Direct"
2652
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002653config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002654 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002655 depends on OLPC
2656
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002657config PCI_GOANY
2658 bool "Any"
2659
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002660endchoice
2661
2662config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002663 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002664 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002665
2666# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2667config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002668 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002669 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002670
2671config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002672 bool "Support mmconfig PCI config space access" if X86_64
2673 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002674 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002675 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002676
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002677config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002678 def_bool y
2679 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002680
Alex Nixonb5401a92010-03-18 16:31:34 -04002681config PCI_XEN
2682 def_bool y
2683 depends on PCI && XEN
2684 select SWIOTLB_XEN
2685
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002686config MMCONF_FAM10H
2687 def_bool y
2688 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002689
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002690config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002691 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002692 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002693 help
2694 Read the PCI windows out of the CNB20LE host bridge. This allows
2695 PCI hotplug to work on systems with the CNB20LE chipset which do
2696 not have ACPI.
2697
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002698 There's no public spec for this chipset, and this functionality
2699 is known to be incomplete.
2700
2701 You should say N unless you know you need this.
2702
William Breathitt Gray3a495512016-05-27 18:08:27 -04002703config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002704 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002705 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002706 Expose ISA bus device drivers and options available for selection and
2707 configuration. Enable this option if your target machine has an ISA
2708 bus. ISA is an older system, displaced by PCI and newer bus
2709 architectures -- if your target machine is modern, it probably does
2710 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002711
2712 If unsure, say N.
2713
David Rientjes1c00f012011-03-22 16:34:59 -07002714# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002715config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002716 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2717 default y
2718 help
2719 Enables ISA-style DMA support for devices requiring such controllers.
2720 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002721
Linus Torvalds51e68d02016-05-21 10:25:19 -07002722if X86_32
2723
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002724config ISA
2725 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002726 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002727 Find out whether you have ISA slots on your motherboard. ISA is the
2728 name of a bus system, i.e. the way the CPU talks to the other stuff
2729 inside your box. Other bus systems are PCI, EISA, MicroChannel
2730 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2731 newer boards don't support it. If you have ISA, say Y, otherwise N.
2732
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002733config SCx200
2734 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002735 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002736 This provides basic support for National Semiconductor's
2737 (now AMD's) Geode processors. The driver probes for the
2738 PCI-IDs of several on-chip devices, so its a good dependency
2739 for other scx200_* drivers.
2740
2741 If compiled as a module, the driver is named scx200.
2742
2743config SCx200HR_TIMER
2744 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002745 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002746 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002747 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002748 This driver provides a clocksource built upon the on-chip
2749 27MHz high-resolution timer. Its also a workaround for
2750 NSC Geode SC-1100's buggy TSC, which loses time when the
2751 processor goes idle (as is done by the scheduler). The
2752 other workaround is idle=poll boot option.
2753
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002754config OLPC
2755 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002756 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002757 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002758 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002759 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002760 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002761 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002762 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002763 Add support for detecting the unique features of the OLPC
2764 XO hardware.
2765
Daniel Drakea3128582011-06-25 17:34:10 +01002766config OLPC_XO1_PM
2767 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002768 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002769 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002770 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002771
Daniel Drakecfee9592011-06-25 17:34:17 +01002772config OLPC_XO1_RTC
2773 bool "OLPC XO-1 Real Time Clock"
2774 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2775 ---help---
2776 Add support for the XO-1 real time clock, which can be used as a
2777 programmable wakeup source.
2778
Daniel Drake7feda8e2011-06-25 17:34:12 +01002779config OLPC_XO1_SCI
2780 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002781 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002782 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002783 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002784 ---help---
2785 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002786 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002787 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002788 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002789 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002790 - AC adapter status updates
2791 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002792
Daniel Drakea0f30f52011-06-25 17:34:18 +01002793config OLPC_XO15_SCI
2794 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002795 depends on OLPC && ACPI
2796 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002797 ---help---
2798 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2799 - EC-driven system wakeups
2800 - AC adapter status updates
2801 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002802
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002803config ALIX
2804 bool "PCEngines ALIX System Support (LED setup)"
2805 select GPIOLIB
2806 ---help---
2807 This option enables system support for the PCEngines ALIX.
2808 At present this just sets up LEDs for GPIO control on
2809 ALIX2/3/6 boards. However, other system specific setup should
2810 get added here.
2811
2812 Note: You must still enable the drivers for GPIO and LED support
2813 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2814
2815 Note: You have to set alix.force=1 for boards with Award BIOS.
2816
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002817config NET5501
2818 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2819 select GPIOLIB
2820 ---help---
2821 This option enables system support for the Soekris Engineering net5501.
2822
Philip A. Prindeville31970592012-01-14 01:45:39 -07002823config GEOS
2824 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2825 select GPIOLIB
2826 depends on DMI
2827 ---help---
2828 This option enables system support for the Traverse Technologies GEOS.
2829
Vivien Didelot7d029122013-01-04 16:18:14 -05002830config TS5500
2831 bool "Technologic Systems TS-5500 platform support"
2832 depends on MELAN
2833 select CHECK_SIGNATURE
2834 select NEW_LEDS
2835 select LEDS_CLASS
2836 ---help---
2837 This option enables system support for the Technologic Systems TS-5500.
2838
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002839endif # X86_32
2840
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002841config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002842 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002843 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002844
David Herrmanne3263ab2013-08-02 14:05:22 +02002845config X86_SYSFB
2846 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2847 help
2848 Firmwares often provide initial graphics framebuffers so the BIOS,
2849 bootloader or kernel can show basic video-output during boot for
2850 user-guidance and debugging. Historically, x86 used the VESA BIOS
2851 Extensions and EFI-framebuffers for this, which are mostly limited
2852 to x86.
2853 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2854 framebuffers so the new generic system-framebuffer drivers can be
2855 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002856 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002857 drivers like efifb, vesafb and uvesafb can pick it up.
2858 If this option is not selected, all system framebuffers are always
2859 marked as fallback platform framebuffers as usual.
2860
2861 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2862 not be able to pick up generic system framebuffers if this option
2863 is selected. You are highly encouraged to enable simplefb as
2864 replacement if you select this option. simplefb can correctly deal
2865 with generic system framebuffers. But you should still keep vesafb
2866 and others enabled as fallback if a system framebuffer is
2867 incompatible with simplefb.
2868
2869 If unsure, say Y.
2870
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002871endmenu
2872
2873
Christoph Hellwig15724972018-07-31 13:39:30 +02002874menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002875
2876config IA32_EMULATION
2877 bool "IA32 Emulation"
2878 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002879 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002880 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002881 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002882 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002883 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002884 Include code to run legacy 32-bit programs under a
2885 64-bit kernel. You should likely turn this on, unless you're
2886 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002887
2888config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002889 tristate "IA32 a.out support"
2890 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002891 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002892 ---help---
2893 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002894
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002895config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002896 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002897 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002898 ---help---
2899 Include code to run binaries for the x32 native 32-bit ABI
2900 for 64-bit processors. An x32 process gets access to the
2901 full 64-bit register file and wide data path while leaving
2902 pointers at 32 bits for smaller memory footprint.
2903
2904 You will need a recent binutils (2.22 or later) with
2905 elf32_x86_64 support enabled to compile a kernel with this
2906 option set.
2907
Ingo Molnar953fee12016-11-15 10:22:52 +01002908config COMPAT_32
2909 def_bool y
2910 depends on IA32_EMULATION || X86_32
2911 select HAVE_UID16
2912 select OLD_SIGSUSPEND3
2913
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002914config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002915 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002916 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002917
Jan Beulich3120e252012-09-10 12:41:45 +01002918if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002919config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002920 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002921
2922config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002923 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002924 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002925endif
David Howellsee009e4a02011-03-07 15:06:20 +00002926
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002927endmenu
2928
2929
Keith Packarde5beae12008-11-03 18:21:45 +01002930config HAVE_ATOMIC_IOMAP
2931 def_bool y
2932 depends on X86_32
2933
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002934source "drivers/firmware/Kconfig"
2935
Avi Kivityedf88412007-12-16 11:02:48 +02002936source "arch/x86/kvm/Kconfig"