blob: beea77046f9bab3eef998e8dd4c3248932dbc004 [file] [log] [blame]
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
Steven Price2ae27132020-02-03 17:36:24 -0800123 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200124 select GENERIC_SMP_IDLE_THREAD
125 select GENERIC_STRNCPY_FROM_USER
126 select GENERIC_STRNLEN_USER
127 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100128 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000129 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700130 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200131 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200132 select HAVE_ACPI_APEI if ACPI
133 select HAVE_ACPI_APEI_NMI if ACPI
134 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200135 select HAVE_ARCH_AUDITSYSCALL
136 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
137 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700138 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800139 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800140 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200141 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800142 select HAVE_ARCH_MMAP_RND_BITS if MMU
143 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300144 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700145 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700147 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300148 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200149 select HAVE_ARCH_TRACEHOOK
150 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800151 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700152 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100153 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900154 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200155 select HAVE_CMPXCHG_DOUBLE
156 select HAVE_CMPXCHG_LOCAL
157 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700158 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200159 select HAVE_C_RECORDMCOUNT
160 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700161 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400162 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900163 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500164 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800165 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700166 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100167 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700168 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700169 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400170 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200171 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200172 select HAVE_FUNCTION_GRAPH_TRACER
173 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200174 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530175 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200176 select HAVE_IDE
177 select HAVE_IOREMAP_PROT
178 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
179 select HAVE_IRQ_TIME_ACCOUNTING
180 select HAVE_KERNEL_BZIP2
181 select HAVE_KERNEL_GZIP
182 select HAVE_KERNEL_LZ4
183 select HAVE_KERNEL_LZMA
184 select HAVE_KERNEL_LZO
185 select HAVE_KERNEL_XZ
186 select HAVE_KPROBES
187 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900188 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200189 select HAVE_KRETPROBES
190 select HAVE_KVM
191 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200192 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200193 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500194 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800195 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700196 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200197 select HAVE_OPROFILE
198 select HAVE_OPTPROBES
199 select HAVE_PCSPKR_PLATFORM
200 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200201 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700202 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100203 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200204 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200205 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800206 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200207 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200208 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900209 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900210 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100211 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400212 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200213 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200214 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300215 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100216 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200217 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100218 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200219 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100220 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000221 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200222 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500223 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200224 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200225 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500226 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700228 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200229 select USER_STACKTRACE_SUPPORT
230 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200231 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800232 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530233
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200234config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100235 def_bool y
236 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200237
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700238config OUTPUT_FORMAT
239 string
240 default "elf32-i386" if X86_32
241 default "elf64-x86-64" if X86_64
242
Sam Ravnborg73531902008-05-25 23:03:18 +0200243config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200244 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200245 default "arch/x86/configs/i386_defconfig" if X86_32
246 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200247
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100248config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100249 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100250
251config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100252 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100254config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100255 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100256
Daniel Cashman9e08f572016-01-14 15:20:06 -0800257config ARCH_MMAP_RND_BITS_MIN
258 default 28 if 64BIT
259 default 8
260
261config ARCH_MMAP_RND_BITS_MAX
262 default 32 if 64BIT
263 default 16
264
265config ARCH_MMAP_RND_COMPAT_BITS_MIN
266 default 8
267
268config ARCH_MMAP_RND_COMPAT_BITS_MAX
269 default 16
270
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100271config SBUS
272 bool
273
274config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100275 def_bool y
276 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100277
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100278config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100279 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100280 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000281 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
282
283config GENERIC_BUG_RELATIVE_POINTERS
284 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100285
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100286config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100287 def_bool y
288 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100289
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100290config GENERIC_CALIBRATE_DELAY
291 def_bool y
292
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800293config ARCH_HAS_CPU_RELAX
294 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100295
Pekka Enberg1b27d052008-04-28 02:12:22 -0700296config ARCH_HAS_CACHE_LINE_SIZE
297 def_bool y
298
Dave Hansen316d0972018-04-20 15:20:28 -0700299config ARCH_HAS_FILTER_PGPROT
300 def_bool y
301
Mike Travisdd5af902008-01-30 13:33:32 +0100302config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900303 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100304
Tejun Heo08fc4582009-08-14 15:00:49 +0900305config NEED_PER_CPU_EMBED_FIRST_CHUNK
306 def_bool y
307
308config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900309 def_bool y
310
Johannes Berg801e4062007-12-08 02:12:39 +0100311config ARCH_HIBERNATION_POSSIBLE
312 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100313
Johannes Bergf4cb5702007-12-08 02:14:00 +0100314config ARCH_SUSPEND_POSSIBLE
315 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100316
Steve Capper53313b22013-04-30 08:03:42 +0100317config ARCH_WANT_GENERAL_HUGETLB
318 def_bool y
319
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100320config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000321 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100322
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100323config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000324 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100325
Akinobu Mita6a11f752009-03-31 15:23:17 -0700326config ARCH_SUPPORTS_DEBUG_PAGEALLOC
327 def_bool y
328
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300329config KASAN_SHADOW_OFFSET
330 hex
331 depends on KASAN
332 default 0xdffffc0000000000
333
Shane Wang69575d32009-09-01 18:25:07 -0700334config HAVE_INTEL_TXT
335 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700336 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700337
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100338config X86_32_SMP
339 def_bool y
340 depends on X86_32 && SMP
341
342config X86_64_SMP
343 def_bool y
344 depends on X86_64 && SMP
345
Tejun Heoccbeed32009-02-09 22:17:40 +0900346config X86_32_LAZY_GS
347 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900348 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900349
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530350config ARCH_SUPPORTS_UPROBES
351 def_bool y
352
Rob Herringd20642f2014-04-18 17:19:54 -0500353config FIX_EARLYCON_MEM
354 def_bool y
355
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300356config DYNAMIC_PHYSICAL_MASK
357 bool
358
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700359config PGTABLE_LEVELS
360 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300361 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700362 default 4 if X86_64
363 default 3 if X86_PAE
364 default 2
365
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900366config CC_HAS_SANE_STACKPROTECTOR
367 bool
368 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
369 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
370 help
371 We have to make sure stack protector is unconditionally disabled if
372 the compiler produces broken code.
373
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100374menu "Processor type and features"
375
Randy Dunlap5ee71532012-01-16 11:57:18 -0800376config ZONE_DMA
377 bool "DMA memory allocation support" if EXPERT
378 default y
379 help
380 DMA memory allocation support allows devices with less than 32-bit
381 addressing to allocate within the first 16MB of address space.
382 Disable if no such devices will be used.
383
384 If unsure, say Y.
385
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100386config SMP
387 bool "Symmetric multi-processing support"
388 ---help---
389 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800390 a system with only one CPU, say N. If you have a system with more
391 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100392
Robert Graffham4a474152014-01-23 15:55:29 -0800393 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100394 machines, but will use only one CPU of a multiprocessor machine. If
395 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800396 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100397 will run faster if you say N here.
398
399 Note that if you say Y here and choose architecture "586" or
400 "Pentium" under "Processor family", the kernel will not work on 486
401 architectures. Similarly, multiprocessor kernels for the "PPro"
402 architecture may not work on all Pentium based boards.
403
404 People using multiprocessor machines who say Y here should also say
405 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
406 Management" code will be disabled if you say Y here.
407
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300408 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300409 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100410 <http://www.tldp.org/docs.html#howto>.
411
412 If you don't know what to do here, say N.
413
Josh Triplett9def39be2013-10-30 08:09:45 -0700414config X86_FEATURE_NAMES
415 bool "Processor feature human-readable names" if EMBEDDED
416 default y
417 ---help---
418 This option compiles in a table of x86 feature bits and corresponding
419 names. This is required to support /proc/cpuinfo and a few kernel
420 messages. You can disable this to save space, at the expense of
421 making those few kernel messages show numeric feature bits instead.
422
423 If in doubt, say Y.
424
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800425config X86_X2APIC
426 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200427 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800428 ---help---
429 This enables x2apic support on CPUs that have this feature.
430
431 This allows 32-bit apic IDs (so it can support very large systems),
432 and accesses the local apic via MSRs not via mmio.
433
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800434 If you don't know what to do here, say N.
435
Yinghai Lu6695c852008-06-19 12:13:09 -0700436config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700437 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000438 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200439 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100440 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700441 For old smp systems that do not have proper acpi support. Newer systems
442 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700443
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000444config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100445 def_bool y
446 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000447
David Woodhouse76b04382018-01-11 21:46:25 +0000448config RETPOLINE
449 bool "Avoid speculative indirect branches in kernel"
450 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100451 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000452 help
453 Compile kernel with the retpoline compiler options to guard against
454 kernel-to-user data leaks by avoiding speculative indirect
455 branches. Requires a compiler with -mindirect-branch=thunk-extern
456 support for full protection. The kernel may run slower.
457
Johannes Weinere6d42932019-01-29 17:44:36 -0500458config X86_CPU_RESCTRL
459 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000460 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100461 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800462 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700463 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500464 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000465
466 Provide support for the allocation and monitoring of system resources
467 usage by the CPU.
468
469 Intel calls this Intel Resource Director Technology
470 (Intel(R) RDT). More information about RDT can be found in the
471 Intel x86 Architecture Software Developer Manual.
472
473 AMD calls this AMD Platform Quality of Service (AMD QoS).
474 More information about AMD QoS can be found in the AMD64 Technology
475 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700476
477 Say N if unsure.
478
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800479if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800480config X86_BIGSMP
481 bool "Support for big SMP systems with more than 8 CPUs"
482 depends on SMP
483 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -0800484 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800485
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800486config X86_EXTENDED_PLATFORM
487 bool "Support for extended (non-PC) x86 platforms"
488 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100489 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100490 If you disable this option then the kernel will only support
491 standard PC platforms. (which covers the vast majority of
492 systems out there.)
493
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800494 If you enable this option then you'll be able to select support
495 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100496 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800497 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800498 RDC R-321x SoC
499 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200500 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200501 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100502
503 If you have one of these systems, or if you want to build a
504 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800505endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100506
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800507if X86_64
508config X86_EXTENDED_PLATFORM
509 bool "Support for extended (non-PC) x86 platforms"
510 default y
511 ---help---
512 If you disable this option then the kernel will only support
513 standard PC platforms. (which covers the vast majority of
514 systems out there.)
515
516 If you enable this option then you'll be able to select support
517 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800518 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800519 ScaleMP vSMP
520 SGI Ultraviolet
521
522 If you have one of these systems, or if you want to build a
523 generic distribution kernel, say Y here - otherwise say N.
524endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800525# This is an alphabetically sorted list of 64 bit extended platforms
526# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800527config X86_NUMACHIP
528 bool "Numascale NumaChip"
529 depends on X86_64
530 depends on X86_EXTENDED_PLATFORM
531 depends on NUMA
532 depends on SMP
533 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700534 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800535 ---help---
536 Adds support for Numascale NumaChip large-SMP systems. Needed to
537 enable more than ~168 cores.
538 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100539
Ingo Molnar6a485652009-01-27 18:29:13 +0100540config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800541 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100542 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100543 select PARAVIRT
544 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800545 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300546 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100547 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100548 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
549 supposed to run on these EM64T-based machines. Only choose this option
550 if you have one of these machines.
551
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800552config X86_UV
553 bool "SGI Ultraviolet"
554 depends on X86_64
555 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500556 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800557 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700558 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200559 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800560 ---help---
561 This option is needed in order to support SGI Ultraviolet systems.
562 If you don't have one of these, you should say N here.
563
564# Following is an alphabetically sorted list of 32 bit extended platforms
565# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100566
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000567config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100568 bool "Goldfish (Virtual Platform)"
569 depends on X86_EXTENDED_PLATFORM
570 ---help---
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000571 Enable support for the Goldfish virtual platform used primarily
572 for Android development. Unless you are building for the Android
573 Goldfish emulator say N here.
574
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800575config X86_INTEL_CE
576 bool "CE4100 TV platform"
577 depends on PCI
578 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800579 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800580 depends on X86_32
581 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800582 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100583 select OF
584 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800585 ---help---
586 Select for the Intel CE media processor (CE4100) SOC.
587 This option compiles in support for the CE4100 SOC for settop
588 boxes and media devices.
589
David Cohen4cb9b002013-12-16 17:37:26 -0800590config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100591 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100592 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800593 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000594 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200595 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000596 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000597 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800598 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000599 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000600 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000601 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000602 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000603 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800604 Select to build a kernel capable of supporting Intel MID (Mobile
605 Internet Device) platform systems which do not have the PCI legacy
606 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000607
David Cohen4cb9b002013-12-16 17:37:26 -0800608 Intel MID platforms are based on an Intel processor and chipset which
609 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100610
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000611config X86_INTEL_QUARK
612 bool "Intel Quark platform support"
613 depends on X86_32
614 depends on X86_EXTENDED_PLATFORM
615 depends on X86_PLATFORM_DEVICES
616 depends on X86_TSC
617 depends on PCI
618 depends on PCI_GOANY
619 depends on X86_IO_APIC
620 select IOSF_MBI
621 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200622 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000623 ---help---
624 Select to include support for Quark X1000 SoC.
625 Say Y here if you have a Quark based system such as the Arduino
626 compatible Intel Galileo.
627
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000628config X86_INTEL_LPSS
629 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000630 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000631 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300632 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100633 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000634 ---help---
635 Select to build support for Intel Low Power Subsystem such as
636 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300637 things like clock tree (common clock framework) and pincontrol
638 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000639
Ken Xue92082a82015-02-06 08:27:51 +0800640config X86_AMD_PLATFORM_DEVICE
641 bool "AMD ACPI2Platform devices support"
642 depends on ACPI
643 select COMMON_CLK
644 select PINCTRL
645 ---help---
646 Select to interpret AMD specific ACPI device to platform device
647 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
648 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
649 implemented under PINCTRL subsystem.
650
David E. Boxced3ce72014-09-17 22:13:50 -0700651config IOSF_MBI
652 tristate "Intel SoC IOSF Sideband support for SoC platforms"
653 depends on PCI
654 ---help---
655 This option enables sideband register access support for Intel SoC
656 platforms. On these platforms the IOSF sideband is used in lieu of
657 MSR's for some register accesses, mostly but not limited to thermal
658 and power. Drivers may query the availability of this device to
659 determine if they need the sideband in order to work on these
660 platforms. The sideband is available on the following SoC products.
661 This list is not meant to be exclusive.
662 - BayTrail
663 - Braswell
664 - Quark
665
666 You should say Y if you are running a kernel on one of these SoC's.
667
David E. Boxed2226b2014-09-17 22:13:51 -0700668config IOSF_MBI_DEBUG
669 bool "Enable IOSF sideband access through debugfs"
670 depends on IOSF_MBI && DEBUG_FS
671 ---help---
672 Select this option to expose the IOSF sideband access registers (MCR,
673 MDR, MCRX) through debugfs to write and read register information from
674 different units on the SoC. This is most useful for obtaining device
675 state information for debug and analysis. As this is a general access
676 mechanism, users of this option would have specific knowledge of the
677 device they want to access.
678
679 If you don't require the option or are in doubt, say N.
680
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800681config X86_RDC321X
682 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100683 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800684 depends on X86_EXTENDED_PLATFORM
685 select M486
686 select X86_REBOOTFIXUPS
687 ---help---
688 This option is needed for RDC R-321x system-on-chip, also known
689 as R-8610-(G).
690 If you don't have one of these chips, you should say N here.
691
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100692config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100693 bool "Support non-standard 32-bit SMP architectures"
694 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800695 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100696 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800697 This option compiles in the bigsmp and STA2X11 default
698 subarchitectures. It is intended for a generic binary
699 kernel. If you select them all, kernel will probe it one by
700 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700701
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800702# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700703
Linus Torvaldsd949f362009-09-26 09:35:07 -0700704config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100705 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700706 # MCE code calls memory_failure():
707 depends on X86_MCE
708 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700709 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
710 depends on X86_64 || !SPARSEMEM
711 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700712
Alessandro Rubini83125a32012-04-04 19:40:21 +0200713config STA2X11
714 bool "STA2X11 Companion Chip Support"
715 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200716 select SWIOTLB
717 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200718 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200719 ---help---
720 This adds support for boards based on the STA2X11 IO-Hub,
721 a.k.a. "ConneXt". The chip is used in place of the standard
722 PC chipset, so all "standard" peripherals are missing. If this
723 option is selected the kernel will still be able to boot on
724 standard PC machines.
725
Shérab82148d12010-09-25 06:06:57 +0200726config X86_32_IRIS
727 tristate "Eurobraille/Iris poweroff module"
728 depends on X86_32
729 ---help---
730 The Iris machines from EuroBraille do not have APM or ACPI support
731 to shut themselves down properly. A special I/O sequence is
732 needed to do so, which is what this module does at
733 kernel shutdown.
734
735 This is only for Iris machines from EuroBraille.
736
737 If unused, say N.
738
Ingo Molnarae1e9132008-11-11 09:05:16 +0100739config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100740 def_bool y
741 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800742 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100743 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100744 Calculate simpler /proc/<PID>/wchan values. If this option
745 is disabled then wchan values will recurse back to the
746 caller function. This provides more accurate wchan values,
747 at the expense of slightly more scheduling overhead.
748
749 If in doubt, say "Y".
750
Borislav Petkov6276a072013-03-04 21:20:21 +0100751menuconfig HYPERVISOR_GUEST
752 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100753 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100754 Say Y here to enable options for running Linux under various hyper-
755 visors. This option enables basic hypervisor detection and platform
756 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100757
Borislav Petkov6276a072013-03-04 21:20:21 +0100758 If you say N, all options in this submenu will be skipped and
759 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100760
Borislav Petkov6276a072013-03-04 21:20:21 +0100761if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100762
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100763config PARAVIRT
764 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100765 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100766 This changes the kernel so it can modify itself when it is run
767 under a hypervisor, potentially improving performance significantly
768 over full virtualization. However, when run without a hypervisor
769 the kernel is theoretically slower and slightly larger.
770
Juergen Grossc00a2802018-08-28 09:40:21 +0200771config PARAVIRT_XXL
772 bool
773
Borislav Petkov6276a072013-03-04 21:20:21 +0100774config PARAVIRT_DEBUG
775 bool "paravirt-ops debugging"
776 depends on PARAVIRT && DEBUG_KERNEL
777 ---help---
778 Enable to debug paravirt_ops internals. Specifically, BUG if
779 a paravirt_op is missing when it is called.
780
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700781config PARAVIRT_SPINLOCKS
782 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700783 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700784 ---help---
785 Paravirtualized spinlocks allow a pvops backend to replace the
786 spinlock implementation with something virtualization-friendly
787 (for example, block the virtual CPU rather than spinning).
788
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530789 It has a minimal impact on native kernels and gives a nice performance
790 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700791
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530792 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700793
Zhao Yakuiecca25022019-04-30 11:45:23 +0800794config X86_HV_CALLBACK_VECTOR
795 def_bool n
796
Borislav Petkov6276a072013-03-04 21:20:21 +0100797source "arch/x86/xen/Kconfig"
798
799config KVM_GUEST
800 bool "KVM Guest support (including kvmclock)"
801 depends on PARAVIRT
802 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300803 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100804 default y
805 ---help---
806 This option enables various optimizations for running under the KVM
807 hypervisor. It includes a paravirtualized clock, so that instead
808 of relying on a PIT (or probably other) emulation by the
809 underlying device model, the host provides the guest with
810 timing infrastructure such as time of day, and system time
811
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300812config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100813 def_bool n
814 prompt "Disable host haltpoll when loading haltpoll driver"
815 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300816 If virtualized under KVM, disable host haltpoll.
817
Maran Wilson77336072018-12-10 11:07:28 -0800818config PVH
819 bool "Support for running PVH guests"
820 ---help---
821 This option enables the PVH entry point for guest virtual machines
822 as specified in the x86/HVM direct boot ABI.
823
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530824config KVM_DEBUG_FS
825 bool "Enable debug information for KVM Guests in debugfs"
826 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530827 ---help---
828 This option enables collection of various statistics for KVM guest.
829 Statistics are displayed in debugfs filesystem. Enabling this option
830 may incur significant overhead.
831
Borislav Petkov6276a072013-03-04 21:20:21 +0100832config PARAVIRT_TIME_ACCOUNTING
833 bool "Paravirtual steal time accounting"
834 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100835 ---help---
836 Select this option to enable fine granularity task steal time
837 accounting. Time spent executing other tasks in parallel with
838 the current vCPU is discounted from the vCPU power. To account for
839 that, there can be a small performance impact.
840
841 If in doubt, say N here.
842
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200843config PARAVIRT_CLOCK
844 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200845
Jan Kiszka4a362602017-11-27 09:11:46 +0100846config JAILHOUSE_GUEST
847 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100848 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100849 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100850 ---help---
851 This option allows to run Linux as guest in a Jailhouse non-root
852 cell. You can leave this option disabled if you only want to start
853 Jailhouse and run Linux afterwards in the root cell.
854
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800855config ACRN_GUEST
856 bool "ACRN Guest support"
857 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800858 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800859 help
860 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
861 a flexible, lightweight reference open-source hypervisor, built with
862 real-time and safety-criticality in mind. It is built for embedded
863 IOT with small footprint and real-time features. More details can be
864 found in https://projectacrn.org/.
865
Borislav Petkov6276a072013-03-04 21:20:21 +0100866endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400867
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100868source "arch/x86/Kconfig.cpu"
869
870config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100871 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100872 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100873 ---help---
874 Use the IA-PC HPET (High Precision Event Timer) to manage
875 time in preference to the PIT and RTC, if a HPET is
876 present.
877 HPET is the next generation timer replacing legacy 8254s.
878 The HPET provides a stable time base on SMP
879 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200880 as it is off-chip. The interface used is documented
881 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100882
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100883 You can safely choose Y here. However, HPET will only be
884 activated if the platform and the BIOS support this feature.
885 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100886
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100887 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100888
889config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100890 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800891 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100892
Jacob Panbb24c472009-09-02 07:37:17 -0700893config APB_TIMER
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100894 def_bool y if X86_INTEL_MID
895 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
896 select DW_APB_TIMER
897 depends on X86_INTEL_MID && SFI
898 help
899 APB timer is the replacement for 8254, HPET on X86 MID platforms.
900 The APBT provides a stable time base on SMP
901 systems, unlike the TSC, but it is more expensive to access,
902 as it is off-chip. APB timers are always running regardless of CPU
903 C states, they are used as per CPU clockevent device when possible.
Jacob Panbb24c472009-09-02 07:37:17 -0700904
David Rientjes6a108a12011-01-20 14:44:16 -0800905# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100906# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700907config DMI
908 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800909 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800910 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100911 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700912 Enabled scanning of DMI to identify machine quirks. Say Y
913 here unless you have verified that your setup is not
914 affected by entries in the DMI blacklist. Required by PNP
915 BIOS code.
916
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100917config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700918 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200919 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100920 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200921 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100922 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200923 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
924 GART based hardware IOMMUs.
925
926 The GART supports full DMA access for devices with 32-bit access
927 limitations, on systems with more than 3 GB. This is usually needed
928 for USB, sound, many IDE/SATA chipsets and some other devices.
929
930 Newer systems typically have a modern AMD IOMMU, supported via
931 the CONFIG_AMD_IOMMU=y config option.
932
933 In normal configurations this driver is only active when needed:
934 there's more than 3 GB of memory and the system contains a
935 32-bit limited device.
936
937 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100938
Mike Travis1184dc22008-05-12 21:21:12 +0200939config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200940 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700941 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800942 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100943 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200944 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200945 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100946
Ingo Molnaraec64872018-02-10 12:36:29 +0100947#
948# The maximum number of CPUs supported:
949#
950# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951# and which can be configured interactively in the
952# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953#
954# The ranges are different on 32-bit and 64-bit kernels, depending on
955# hardware capabilities and scalability features of the kernel.
956#
957# ( If MAXSMP is enabled we just use the highest possible value and disable
958# interactive configuration. )
959#
960
961config NR_CPUS_RANGE_BEGIN
962 int
963 default NR_CPUS_RANGE_END if MAXSMP
964 default 1 if !SMP
965 default 2
966
967config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800968 int
969 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100970 default 64 if SMP && X86_BIGSMP
971 default 8 if SMP && !X86_BIGSMP
972 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800973
Ingo Molnaraec64872018-02-10 12:36:29 +0100974config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800975 int
976 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500977 default 8192 if SMP && CPUMASK_OFFSTACK
978 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100979 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800980
Ingo Molnaraec64872018-02-10 12:36:29 +0100981config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800982 int
983 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100984 default 32 if X86_BIGSMP
985 default 8 if SMP
986 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800987
Ingo Molnaraec64872018-02-10 12:36:29 +0100988config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800989 int
990 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100991 default 8192 if MAXSMP
992 default 64 if SMP
993 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800994
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100995config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800996 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100997 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100999 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001000 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001001 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001002 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001003 minimum value which makes sense is 2.
1004
Ingo Molnaraec64872018-02-10 12:36:29 +01001005 This is purely to save memory: each supported CPU adds about 8KB
1006 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001007
1008config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001009 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001010
1011config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001012 def_bool y
1013 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001014 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001015 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001016 Multi-core scheduler support improves the CPU scheduler's decision
1017 making when dealing with multi-core CPU chips at a cost of slightly
1018 increased overhead in some places. If unsure say N here.
1019
Tim Chende966cf2016-11-29 10:43:27 -08001020config SCHED_MC_PRIO
1021 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001022 depends on SCHED_MC && CPU_SUP_INTEL
1023 select X86_INTEL_PSTATE
1024 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001025 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001026 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001027 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1028 core ordering determined at manufacturing time, which allows
1029 certain cores to reach higher turbo frequencies (when running
1030 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001031
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001032 Enabling this kernel feature teaches the scheduler about
1033 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1034 scheduler's CPU selection logic accordingly, so that higher
1035 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001036
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001037 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001038
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001039 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001040
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001041config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001042 def_bool y
1043 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001044
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001045config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001046 bool "Local APIC support on uniprocessors" if !PCI_MSI
1047 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001048 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001049 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001050 A local APIC (Advanced Programmable Interrupt Controller) is an
1051 integrated interrupt controller in the CPU. If you have a single-CPU
1052 system which has a processor with a local APIC, you can say Y here to
1053 enable and use it. If you say Y here even though your machine doesn't
1054 have a local APIC, then the kernel will still run with no slowdown at
1055 all. The local APIC supports CPU-generated self-interrupts (timer,
1056 performance counters), and the NMI watchdog which detects hard
1057 lockups.
1058
1059config X86_UP_IOAPIC
1060 bool "IO-APIC support on uniprocessors"
1061 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001062 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001063 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1064 SMP-capable replacement for PC-style interrupt controllers. Most
1065 SMP systems and many recent uniprocessor systems have one.
1066
1067 If you have a single-CPU system with an IO-APIC, you can say Y here
1068 to use it. If you say Y here even though your machine doesn't have
1069 an IO-APIC, then the kernel will still run with no slowdown at all.
1070
1071config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001072 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001073 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001074 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001075 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001076
1077config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001078 def_bool y
1079 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001080
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001081config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1082 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001083 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001084 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001085 This option enables a workaround that fixes a source of
1086 spurious interrupts. This is recommended when threaded
1087 interrupt handling is used on systems where the generation of
1088 superfluous "boot interrupts" cannot be disabled.
1089
1090 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1091 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1092 kernel does during interrupt handling). On chipsets where this
1093 boot IRQ generation cannot be disabled, this workaround keeps
1094 the original IRQ line masked so that only the equivalent "boot
1095 IRQ" is delivered to the CPUs. The workaround also tells the
1096 kernel to set up the IRQ handler on the boot IRQ line. In this
1097 way only one interrupt is delivered to the kernel. Otherwise
1098 the spurious second interrupt may cause the kernel to bring
1099 down (vital) interrupt lines.
1100
1101 Only affects "broken" chipsets. Interrupt sharing may be
1102 increased on these systems.
1103
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001104config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001105 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001106 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001107 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001108 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001109 Machine Check support allows the processor to notify the
1110 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001111 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001112 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001113
Tony Luck5de97c92017-03-27 11:33:03 +02001114config X86_MCELOG_LEGACY
1115 bool "Support for deprecated /dev/mcelog character device"
1116 depends on X86_MCE
1117 ---help---
1118 Enable support for /dev/mcelog which is needed by the old mcelog
1119 userspace logging daemon. Consider switching to the new generation
1120 rasdaemon solution.
1121
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001122config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001123 def_bool y
1124 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001125 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001126 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001127 Additional support for intel specific MCE features such as
1128 the thermal monitor.
1129
1130config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001131 def_bool y
1132 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001133 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001134 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001135 Additional support for AMD specific MCE features such as
1136 the DRAM Error Threshold.
1137
Andi Kleen4efc0672009-04-28 19:07:31 +02001138config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001139 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001140 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001141 ---help---
1142 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001143 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001144 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001145
Andi Kleenb2762682009-02-12 13:49:31 +01001146config X86_MCE_THRESHOLD
1147 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001148 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001149
Andi Kleenea149b32009-04-29 19:31:00 +02001150config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001151 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001152 tristate "Machine check injector support"
1153 ---help---
1154 Provide support for injecting machine checks for testing purposes.
1155 If you don't know what a machine check is and you don't do kernel
1156 QA it is safe to say n.
1157
Andi Kleen4efc0672009-04-28 19:07:31 +02001158config X86_THERMAL_VECTOR
1159 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001160 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001161
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001162source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001163
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001164config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001165 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001166 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001167 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001168 This option allows user programs to put the CPU into V8086
1169 mode, which is an 80286-era approximation of 16-bit real mode.
1170
1171 Some very old versions of X and/or vbetool require this option
1172 for user mode setting. Similarly, DOSEMU will use it if
1173 available to accelerate real mode DOS programs. However, any
1174 recent version of DOSEMU, X, or vbetool should be fully
1175 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001176 fall back to software emulation. Nevertheless, if you are using
1177 a 16-bit DOS program where 16-bit performance matters, vm86
1178 mode might be faster than emulation and you might want to
1179 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001180
Ingo Molnar1e642812015-09-05 08:58:10 +02001181 Note that any app that works on a 64-bit kernel is unlikely to
1182 need this option, as 64-bit kernels don't, and can't, support
1183 V8086 mode. This option is also unrelated to 16-bit protected
1184 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001185
Ingo Molnar1e642812015-09-05 08:58:10 +02001186 Enabling this option increases the complexity of the kernel
1187 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001188
Ingo Molnar1e642812015-09-05 08:58:10 +02001189 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001190
1191config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001192 bool
1193 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001194
1195config X86_16BIT
1196 bool "Enable support for 16-bit segments" if EXPERT
1197 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001198 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001199 ---help---
1200 This option is required by programs like Wine to run 16-bit
1201 protected mode legacy code on x86 processors. Disabling
1202 this option saves about 300 bytes on i386, or around 6K text
1203 plus 16K runtime memory on x86-64,
1204
1205config X86_ESPFIX32
1206 def_bool y
1207 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001208
H. Peter Anvin197725d2014-05-04 10:00:49 -07001209config X86_ESPFIX64
1210 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001211 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001212
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001213config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001214 bool "Enable vsyscall emulation" if EXPERT
1215 default y
1216 depends on X86_64
1217 ---help---
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001218 This enables emulation of the legacy vsyscall page. Disabling
1219 it is roughly equivalent to booting with vsyscall=none, except
1220 that it will also disable the helpful warning if a program
1221 tries to use a vsyscall. With this option set to N, offending
1222 programs will just segfault, citing addresses of the form
1223 0xffffffffff600?00.
1224
1225 This option is required by many programs built before 2013, and
1226 care should be used even with newer programs if set to N.
1227
1228 Disabling this option saves about 7K of kernel size and
1229 possibly 4K of additional runtime pagetable memory.
1230
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001231config X86_IOPL_IOPERM
1232 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001233 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001234 ---help---
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001235 This enables the ioperm() and iopl() syscalls which are necessary
1236 for legacy applications.
1237
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001238 Legacy IOPL support is an overbroad mechanism which allows user
1239 space aside of accessing all 65536 I/O ports also to disable
1240 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1241 capabilities and permission from potentially active security
1242 modules.
1243
1244 The emulation restricts the functionality of the syscall to
1245 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001246 ability to disable interrupts from user space which would be
1247 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001248
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001249config TOSHIBA
1250 tristate "Toshiba Laptop support"
1251 depends on X86_32
1252 ---help---
1253 This adds a driver to safely access the System Management Mode of
1254 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1255 not work on models with a Phoenix BIOS. The System Management Mode
1256 is used to set the BIOS and power saving options on Toshiba portables.
1257
1258 For information on utilities to make use of this driver see the
1259 Toshiba Linux utilities web site at:
1260 <http://www.buzzard.org.uk/toshiba/>.
1261
1262 Say Y if you intend to run this kernel on a Toshiba portable.
1263 Say N otherwise.
1264
1265config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001266 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001267 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001268 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001269 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001270 This option enables legacy /proc/i8k userspace interface in hwmon
1271 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1272 temperature and allows controlling fan speeds of Dell laptops via
1273 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1274 it reports also power and hotkey status. For fan speed control is
1275 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001276
Pali Rohár039ae582015-05-14 13:16:37 +02001277 Say Y if you intend to run this kernel on old Dell laptops or want to
1278 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001279 Say N otherwise.
1280
1281config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001282 bool "Enable X86 board specific fixups for reboot"
1283 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001284 ---help---
1285 This enables chipset and/or board specific fixups to be done
1286 in order to get reboot to work correctly. This is only needed on
1287 some combinations of hardware and BIOS. The symptom, for which
1288 this config is intended, is when reboot ends with a stalled/hung
1289 system.
1290
1291 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001292 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001293
1294 Say Y if you want to enable the fixup. Currently, it's safe to
1295 enable this option even if you don't need it.
1296 Say N otherwise.
1297
1298config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001299 bool "CPU microcode loading support"
1300 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001301 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001302 select FW_LOADER
1303 ---help---
1304 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001305 Intel and AMD processors. The Intel support is for the IA32 family,
1306 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1307 AMD support is for families 0x10 and later. You will obviously need
1308 the actual microcode binary data itself which is not shipped with
1309 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001310
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001311 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001312 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001313 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1314 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001315
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001316 In addition, you can build the microcode into the kernel. For that you
1317 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1318 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001319
Peter Oruba8d86f392008-07-28 18:44:21 +02001320config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001321 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001322 depends on MICROCODE
1323 default MICROCODE
1324 select FW_LOADER
1325 ---help---
1326 This options enables microcode patch loading support for Intel
1327 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001328
Alanb8989db2014-01-20 18:01:56 +00001329 For the current Intel microcode data package go to
1330 <https://downloadcenter.intel.com> and search for
1331 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001332
Peter Oruba80cc9f12008-07-28 18:44:22 +02001333config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001334 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001335 depends on MICROCODE
1336 select FW_LOADER
1337 ---help---
1338 If you select this option, microcode patch loading support for AMD
1339 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001340
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001341config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001342 bool "Ancient loading interface (DEPRECATED)"
1343 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001344 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001345 ---help---
1346 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1347 which was used by userspace tools like iucode_tool and microcode.ctl.
1348 It is inadequate because it runs too late to be able to properly
1349 load microcode on a machine and it needs special tools. Instead, you
1350 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001351 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001352
1353config X86_MSR
1354 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001355 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001356 This device gives privileged processes access to the x86
1357 Model-Specific Registers (MSRs). It is a character device with
1358 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1359 MSR accesses are directed to a specific CPU on multi-processor
1360 systems.
1361
1362config X86_CPUID
1363 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001364 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001365 This device gives processes access to the x86 CPUID instruction to
1366 be executed on a specific processor. It is a character device
1367 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1368 /dev/cpu/31/cpuid.
1369
1370choice
1371 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001372 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001373 depends on X86_32
1374
1375config NOHIGHMEM
1376 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001377 ---help---
1378 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1379 However, the address space of 32-bit x86 processors is only 4
1380 Gigabytes large. That means that, if you have a large amount of
1381 physical memory, not all of it can be "permanently mapped" by the
1382 kernel. The physical memory that's not permanently mapped is called
1383 "high memory".
1384
1385 If you are compiling a kernel which will never run on a machine with
1386 more than 1 Gigabyte total physical RAM, answer "off" here (default
1387 choice and suitable for most users). This will result in a "3GB/1GB"
1388 split: 3GB are mapped so that each process sees a 3GB virtual memory
1389 space and the remaining part of the 4GB virtual memory space is used
1390 by the kernel to permanently map as much physical memory as
1391 possible.
1392
1393 If the machine has between 1 and 4 Gigabytes physical RAM, then
1394 answer "4GB" here.
1395
1396 If more than 4 Gigabytes is used then answer "64GB" here. This
1397 selection turns Intel PAE (Physical Address Extension) mode on.
1398 PAE implements 3-level paging on IA32 processors. PAE is fully
1399 supported by Linux, PAE mode is implemented on all recent Intel
1400 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1401 then the kernel will not boot on CPUs that don't support PAE!
1402
1403 The actual amount of total physical memory will either be
1404 auto detected or can be forced by using a kernel command line option
1405 such as "mem=256M". (Try "man bootparam" or see the documentation of
1406 your boot loader (lilo or loadlin) about how to pass options to the
1407 kernel at boot time.)
1408
1409 If unsure, say "off".
1410
1411config HIGHMEM4G
1412 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001413 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001414 Select this if you have a 32-bit processor and between 1 and 4
1415 gigabytes of physical RAM.
1416
1417config HIGHMEM64G
1418 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001419 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001420 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001421 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001422 Select this if you have a 32-bit processor and more than 4
1423 gigabytes of physical RAM.
1424
1425endchoice
1426
1427choice
David Rientjes6a108a12011-01-20 14:44:16 -08001428 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001429 default VMSPLIT_3G
1430 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001431 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001432 Select the desired split between kernel and user memory.
1433
1434 If the address range available to the kernel is less than the
1435 physical memory installed, the remaining memory will be available
1436 as "high memory". Accessing high memory is a little more costly
1437 than low memory, as it needs to be mapped into the kernel first.
1438 Note that increasing the kernel address space limits the range
1439 available to user programs, making the address space there
1440 tighter. Selecting anything other than the default 3G/1G split
1441 will also likely make your kernel incompatible with binary-only
1442 kernel modules.
1443
1444 If you are not absolutely sure what you are doing, leave this
1445 option alone!
1446
1447 config VMSPLIT_3G
1448 bool "3G/1G user/kernel split"
1449 config VMSPLIT_3G_OPT
1450 depends on !X86_PAE
1451 bool "3G/1G user/kernel split (for full 1G low memory)"
1452 config VMSPLIT_2G
1453 bool "2G/2G user/kernel split"
1454 config VMSPLIT_2G_OPT
1455 depends on !X86_PAE
1456 bool "2G/2G user/kernel split (for full 2G low memory)"
1457 config VMSPLIT_1G
1458 bool "1G/3G user/kernel split"
1459endchoice
1460
1461config PAGE_OFFSET
1462 hex
1463 default 0xB0000000 if VMSPLIT_3G_OPT
1464 default 0x80000000 if VMSPLIT_2G
1465 default 0x78000000 if VMSPLIT_2G_OPT
1466 default 0x40000000 if VMSPLIT_1G
1467 default 0xC0000000
1468 depends on X86_32
1469
1470config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001471 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001472 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001473
1474config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001475 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001476 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001477 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001478 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001479 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001480 PAE is required for NX support, and furthermore enables
1481 larger swapspace support for non-overcommit purposes. It
1482 has the cost of more pagetable lookup overhead, and also
1483 consumes more pagetable space per process.
1484
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001485config X86_5LEVEL
1486 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001487 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001488 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001489 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001490 depends on X86_64
1491 ---help---
1492 5-level paging enables access to larger address space:
1493 upto 128 PiB of virtual address space and 4 PiB of
1494 physical address space.
1495
1496 It will be supported by future Intel CPUs.
1497
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001498 A kernel with the option enabled can be booted on machines that
1499 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001500
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001501 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001502 information.
1503
1504 Say N if unsure.
1505
Ingo Molnar10971ab2015-03-05 08:18:23 +01001506config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001507 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001508 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001509 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001510 Certain kernel features effectively disable kernel
1511 linear 1 GB mappings (even if the CPU otherwise
1512 supports them), so don't confuse the user by printing
1513 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001514
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001515config X86_CPA_STATISTICS
1516 bool "Enable statistic for Change Page Attribute"
1517 depends on DEBUG_FS
1518 ---help---
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001519 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001520 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001521 page mappings when mapping protections are changed.
1522
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001523config AMD_MEM_ENCRYPT
1524 bool "AMD Secure Memory Encryption (SME) support"
1525 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001526 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001527 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001528 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001529 ---help---
1530 Say yes to enable support for the encryption of system memory.
1531 This requires an AMD processor that supports Secure Memory
1532 Encryption (SME).
1533
1534config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1535 bool "Activate AMD Secure Memory Encryption (SME) by default"
1536 default y
1537 depends on AMD_MEM_ENCRYPT
1538 ---help---
1539 Say yes to have system memory encrypted by default if running on
1540 an AMD processor that supports Secure Memory Encryption (SME).
1541
1542 If set to Y, then the encryption of system memory can be
1543 deactivated with the mem_encrypt=off command line option.
1544
1545 If set to N, then the encryption of system memory can be
1546 activated with the mem_encrypt=on command line option.
1547
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001548# Common NUMA Features
1549config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001550 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001551 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001552 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001554 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -08001555 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001556
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001557 The kernel will try to allocate memory used by a CPU on the
1558 local memory controller of the CPU and add some more
1559 NUMA awareness to the kernel.
1560
Ingo Molnarc280ea52008-11-08 13:29:45 +01001561 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001562 (or later), AMD Opteron, or EM64T NUMA.
1563
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001564 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001565 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001566
1567 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001568
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001569config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001570 def_bool y
1571 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001572 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001573 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001574 Enable AMD NUMA node topology detection. You should say Y here if
1575 you have a multi processor AMD system. This uses an old method to
1576 read the NUMA configuration directly from the builtin Northbridge
1577 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1578 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001579
1580config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001581 def_bool y
1582 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001583 depends on X86_64 && NUMA && ACPI && PCI
1584 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001585 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001586 Enable ACPI SRAT based node topology detection.
1587
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001588# Some NUMA nodes have memory ranges that span
1589# other nodes. Even though a pfn is valid and
1590# between a node's start and end pfns, it may not
1591# reside on that node. See memmap_init_zone()
1592# for details.
1593config NODES_SPAN_OTHER_NODES
1594 def_bool y
1595 depends on X86_64_ACPI_NUMA
1596
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001597config NUMA_EMU
1598 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001599 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001600 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001601 Enable NUMA emulation. A flat machine will be split
1602 into virtual nodes when booted with "numa=fake=N", where N is the
1603 number of nodes. This is only useful for debugging.
1604
1605config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001606 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001607 range 1 10
1608 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001609 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001610 default "3"
1611 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001612 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001613 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001614 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001616config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001617 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001618 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001619
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001620config ARCH_FLATMEM_ENABLE
1621 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001622 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001623
1624config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001625 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001626 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001627 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001628
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001629config ARCH_SPARSEMEM_ENABLE
1630 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001631 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001632 select SPARSEMEM_STATIC if X86_32
1633 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1634
Tejun Heo3b166512011-04-01 11:15:12 +02001635config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001636 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001637
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001638config ARCH_SELECT_MEMORY_MODEL
1639 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001640 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001641
1642config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001643 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001644 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001645 help
1646 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001647 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001648 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001649
Tejun Heo3b166512011-04-01 11:15:12 +02001650config ARCH_PROC_KCORE_TEXT
1651 def_bool y
1652 depends on X86_64 && PROC_KCORE
1653
Avi Kivitya29815a2010-01-10 16:28:09 +02001654config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001655 hex
1656 default 0 if X86_32
1657 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001658
Dan Williams7a678322015-08-19 00:34:34 -04001659config X86_PMEM_LEGACY_DEVICE
1660 bool
1661
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001662config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001663 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001664 depends on PHYS_ADDR_T_64BIT
1665 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001666 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001667 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001668 help
1669 Treat memory marked using the non-standard e820 type of 12 as used
1670 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1671 The kernel will offer these regions to the 'pmem' driver so
1672 they can be used for persistent storage.
1673
1674 Say Y if unsure.
1675
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001676config HIGHPTE
1677 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001678 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001679 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001680 The VM uses one page table entry for each page of physical memory.
1681 For systems with a lot of RAM, this can be wasteful of precious
1682 low memory. Setting this option will put user-space page table
1683 entries in high memory.
1684
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001685config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001686 bool "Check for low memory corruption"
1687 ---help---
1688 Periodically check for memory corruption in low memory, which
1689 is suspected to be caused by BIOS. Even when enabled in the
1690 configuration, it is disabled at runtime. Enable it by
1691 setting "memory_corruption_check=1" on the kernel command
1692 line. By default it scans the low 64k of memory every 60
1693 seconds; see the memory_corruption_check_size and
1694 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001695 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001696
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001697 When enabled with the default parameters, this option has
1698 almost no overhead, as it reserves a relatively small amount
1699 of memory and scans it infrequently. It both detects corruption
1700 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001701
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001702 It is, however, intended as a diagnostic tool; if repeatable
1703 BIOS-originated corruption always affects the same memory,
1704 you can use memmap= to prevent the kernel from using that
1705 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001706
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001707config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001708 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001709 depends on X86_CHECK_BIOS_CORRUPTION
1710 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001711 ---help---
1712 Set whether the default state of memory_corruption_check is
1713 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001714
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001715config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001716 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1717 default 64
1718 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001719 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001720 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001721
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001722 The first page contains BIOS data structures that the kernel
1723 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001724
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001725 By default we reserve the first 64K of physical RAM, as a
1726 number of BIOSes are known to corrupt that memory range
1727 during events such as suspend/resume or monitor cable
1728 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001729
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001730 You can set this to 4 if you are absolutely sure that you
1731 trust the BIOS to get all its memory reservations and usages
1732 right. If you know your BIOS have problems beyond the
1733 default 64K area, you can set this to 640 to avoid using the
1734 entire low memory range.
1735
1736 If you have doubts about the BIOS (e.g. suspend/resume does
1737 not work or there's kernel crashes after certain hardware
1738 hotplug events) then you might want to enable
1739 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1740 typical corruption patterns.
1741
1742 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001743
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001744config MATH_EMULATION
1745 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001746 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001747 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001748 ---help---
1749 Linux can emulate a math coprocessor (used for floating point
1750 operations) if you don't have one. 486DX and Pentium processors have
1751 a math coprocessor built in, 486SX and 386 do not, unless you added
1752 a 487DX or 387, respectively. (The messages during boot time can
1753 give you some hints here ["man dmesg"].) Everyone needs either a
1754 coprocessor or this emulation.
1755
1756 If you don't have a math coprocessor, you need to say Y here; if you
1757 say Y here even though you have a coprocessor, the coprocessor will
1758 be used nevertheless. (This behavior can be changed with the kernel
1759 command line option "no387", which comes handy if your coprocessor
1760 is broken. Try "man bootparam" or see the documentation of your boot
1761 loader (lilo or loadlin) about how to pass options to the kernel at
1762 boot time.) This means that it is a good idea to say Y here if you
1763 intend to use this kernel on different machines.
1764
1765 More information about the internals of the Linux math coprocessor
1766 emulation can be found in <file:arch/x86/math-emu/README>.
1767
1768 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1769 kernel, it won't hurt.
1770
1771config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001772 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001773 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001774 ---help---
1775 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1776 the Memory Type Range Registers (MTRRs) may be used to control
1777 processor access to memory ranges. This is most useful if you have
1778 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1779 allows bus write transfers to be combined into a larger transfer
1780 before bursting over the PCI/AGP bus. This can increase performance
1781 of image write operations 2.5 times or more. Saying Y here creates a
1782 /proc/mtrr file which may be used to manipulate your processor's
1783 MTRRs. Typically the X server should use this.
1784
1785 This code has a reasonably generic interface so that similar
1786 control registers on other processors can be easily supported
1787 as well:
1788
1789 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1790 Registers (ARRs) which provide a similar functionality to MTRRs. For
1791 these, the ARRs are used to emulate the MTRRs.
1792 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1793 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1794 write-combining. All of these processors are supported by this code
1795 and it makes sense to say Y here if you have one of them.
1796
1797 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1798 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1799 can lead to all sorts of problems, so it's good to say Y here.
1800
1801 You can safely say Y even if your machine doesn't have MTRRs, you'll
1802 just add about 9 KB to your kernel.
1803
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001804 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001805
Yinghai Lu95ffa242008-04-29 03:52:33 -07001806config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001807 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001808 prompt "MTRR cleanup support"
1809 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001810 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001811 Convert MTRR layout from continuous to discrete, so X drivers can
1812 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001813
Thomas Gleixneraba37282008-07-15 14:48:48 +02001814 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001815 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001816 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001817
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001818 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001819
1820config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001821 int "MTRR cleanup enable value (0-1)"
1822 range 0 1
1823 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001824 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001825 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001826 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001827
Yinghai Lu12031a62008-05-02 02:40:22 -07001828config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1829 int "MTRR cleanup spare reg num (0-7)"
1830 range 0 7
1831 default "1"
1832 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001833 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001834 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001835 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001836
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001837config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001838 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001839 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001840 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001841 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001842 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001843
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001844 PATs are the modern equivalents of MTRRs and are much more
1845 flexible than MTRRs.
1846
1847 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001848 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001849
1850 If unsure, say Y.
1851
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001852config ARCH_USES_PG_UNCACHED
1853 def_bool y
1854 depends on X86_PAT
1855
H. Peter Anvin628c6242011-07-31 13:59:29 -07001856config ARCH_RANDOM
1857 def_bool y
1858 prompt "x86 architectural random number generator" if EXPERT
1859 ---help---
1860 Enable the x86 architectural RDRAND instruction
1861 (Intel Bull Mountain technology) to generate random numbers.
1862 If supported, this is a high bandwidth, cryptographically
1863 secure hardware random number generator.
1864
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001865config X86_SMAP
1866 def_bool y
1867 prompt "Supervisor Mode Access Prevention" if EXPERT
1868 ---help---
1869 Supervisor Mode Access Prevention (SMAP) is a security
1870 feature in newer Intel processors. There is a small
1871 performance cost if this enabled and turned on; there is
1872 also a small increase in the kernel size if this is enabled.
1873
1874 If unsure, say Y.
1875
Babu Mogerb9718802019-11-05 21:25:32 +00001876config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001877 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001878 depends on CPU_SUP_INTEL || CPU_SUP_AMD
1879 prompt "User Mode Instruction Prevention" if EXPERT
Ricardo Neriaa35f892017-11-05 18:27:54 -08001880 ---help---
Babu Mogerb9718802019-11-05 21:25:32 +00001881 User Mode Instruction Prevention (UMIP) is a security feature in
1882 some x86 processors. If enabled, a general protection fault is
1883 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1884 executed in user mode. These instructions unnecessarily expose
1885 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001886
1887 The vast majority of applications do not use these instructions.
1888 For the very few that do, software emulation is provided in
1889 specific cases in protected and virtual-8086 modes. Emulated
1890 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001891
Dave Hansen35e97792016-02-12 13:02:00 -08001892config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001893 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001894 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001895 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001896 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001897 select ARCH_USES_HIGH_VMA_FLAGS
1898 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001899 ---help---
1900 Memory Protection Keys provides a mechanism for enforcing
1901 page-based protections, but without requiring modification of the
1902 page tables when an application changes protection domains.
1903
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001904 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001905
1906 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001907
Michal Hockodb616172019-10-23 12:35:50 +02001908choice
1909 prompt "TSX enable mode"
1910 depends on CPU_SUP_INTEL
1911 default X86_INTEL_TSX_MODE_OFF
1912 help
1913 Intel's TSX (Transactional Synchronization Extensions) feature
1914 allows to optimize locking protocols through lock elision which
1915 can lead to a noticeable performance boost.
1916
1917 On the other hand it has been shown that TSX can be exploited
1918 to form side channel attacks (e.g. TAA) and chances are there
1919 will be more of those attacks discovered in the future.
1920
1921 Therefore TSX is not enabled by default (aka tsx=off). An admin
1922 might override this decision by tsx=on the command line parameter.
1923 Even with TSX enabled, the kernel will attempt to enable the best
1924 possible TAA mitigation setting depending on the microcode available
1925 for the particular machine.
1926
1927 This option allows to set the default tsx mode between tsx=on, =off
1928 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1929 details.
1930
1931 Say off if not sure, auto if TSX is in use but it should be used on safe
1932 platforms or on if TSX is in use and the security aspect of tsx is not
1933 relevant.
1934
1935config X86_INTEL_TSX_MODE_OFF
1936 bool "off"
1937 help
1938 TSX is disabled if possible - equals to tsx=off command line parameter.
1939
1940config X86_INTEL_TSX_MODE_ON
1941 bool "on"
1942 help
1943 TSX is always enabled on TSX capable HW - equals the tsx=on command
1944 line parameter.
1945
1946config X86_INTEL_TSX_MODE_AUTO
1947 bool "auto"
1948 help
1949 TSX is enabled on TSX capable HW that is believed to be safe against
1950 side channel attacks- equals the tsx=auto command line parameter.
1951endchoice
1952
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001953config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001954 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001955 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001956 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001957 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001958 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001959 This enables the kernel to use EFI runtime services that are
1960 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001961
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001962 This option is only useful on systems that have EFI firmware.
1963 In addition, you should use the latest ELILO loader available
1964 at <http://elilo.sourceforge.net> in order to take advantage
1965 of EFI runtime services. However, even with this option, the
1966 resultant kernel should continue to boot on existing non-EFI
1967 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001968
Matt Fleming291f3632011-12-12 21:27:52 +00001969config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001970 bool "EFI stub support"
1971 depends on EFI && !X86_USE_3DNOW
1972 depends on $(cc-option,-mabi=ms) || X86_32
1973 select RELOCATABLE
1974 ---help---
1975 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001976 by EFI firmware without the use of a bootloader.
1977
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001978 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001979
Matt Fleming7d453ee2014-01-10 18:52:06 +00001980config EFI_MIXED
1981 bool "EFI mixed-mode support"
1982 depends on EFI_STUB && X86_64
1983 ---help---
1984 Enabling this feature allows a 64-bit kernel to be booted
1985 on a 32-bit firmware, provided that your CPU supports 64-bit
1986 mode.
1987
1988 Note that it is not possible to boot a mixed-mode enabled
1989 kernel via the EFI boot stub - a bootloader that supports
1990 the EFI handover protocol must be used.
1991
1992 If unsure, say N.
1993
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001994config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001995 def_bool y
1996 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001997 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001998 This kernel feature is useful for number crunching applications
1999 that may need to compute untrusted bytecode during their
2000 execution. By using pipes or other transports made available to
2001 the process as file descriptors supporting the read/write
2002 syscalls, it's possible to isolate those applications in
2003 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04002004 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002005 and the task is only allowed to execute a few safe syscalls
2006 defined by each seccomp mode.
2007
2008 If unsure, say Y. Only embedded should say N here.
2009
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002010source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002011
2012config KEXEC
2013 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07002014 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002015 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002016 kexec is a system call that implements the ability to shutdown your
2017 current kernel, and to start another kernel. It is like a reboot
2018 but it is independent of the system firmware. And like a reboot
2019 you can start any kernel with it, not just Linux.
2020
2021 The name comes from the similarity to the exec system call.
2022
2023 It is an ongoing process to be certain the hardware in a machine
2024 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002025 initially work for you. As of this writing the exact hardware
2026 interface is strongly in flux, so no good recommendation can be
2027 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002028
Vivek Goyal74ca3172014-08-29 15:18:46 -07002029config KEXEC_FILE
2030 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002031 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002032 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002033 depends on X86_64
2034 depends on CRYPTO=y
2035 depends on CRYPTO_SHA256=y
2036 ---help---
2037 This is new version of kexec system call. This system call is
2038 file based and takes file descriptors as system call argument
2039 for kernel and initramfs as opposed to list of segments as
2040 accepted by previous system call.
2041
AKASHI Takahirob799a092018-04-13 15:35:45 -07002042config ARCH_HAS_KEXEC_PURGATORY
2043 def_bool KEXEC_FILE
2044
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002045config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002046 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002047 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002048 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002049
2050 This option makes the kexec_file_load() syscall check for a valid
2051 signature of the kernel image. The image can still be loaded without
2052 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2053 there's a signature that we can check, then it must be valid.
2054
2055 In addition to this option, you need to enable signature
2056 verification for the corresponding kernel image type being
2057 loaded in order for this to work.
2058
2059config KEXEC_SIG_FORCE
2060 bool "Require a valid signature in kexec_file_load() syscall"
2061 depends on KEXEC_SIG
2062 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002063 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002064 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002065
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002066config KEXEC_BZIMAGE_VERIFY_SIG
2067 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002068 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002069 depends on SIGNED_PE_FILE_VERIFICATION
2070 select SYSTEM_TRUSTED_KEYRING
2071 ---help---
2072 Enable bzImage signature verification support.
2073
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002074config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002075 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002076 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002077 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002078 Generate crash dump after being started by kexec.
2079 This should be normally only set in special crash dump kernels
2080 which are loaded in the main kernel with kexec-tools into
2081 a specially reserved region and then later executed after
2082 a crash by kdump/kexec. The crash dump kernel must be compiled
2083 to a memory address not used by the main kernel or BIOS using
2084 PHYSICAL_START, or it must be built as a relocatable image
2085 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002086 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002087
Huang Ying3ab83522008-07-25 19:45:07 -07002088config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002089 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002090 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002091 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002092 Jump between original kernel and kexeced kernel and invoke
2093 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002094
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002095config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002096 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002097 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002098 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002099 This gives the physical address where the kernel is loaded.
2100
2101 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2102 bzImage will decompress itself to above physical address and
2103 run from there. Otherwise, bzImage will run from the address where
2104 it has been loaded by the boot loader and will ignore above physical
2105 address.
2106
2107 In normal kdump cases one does not have to set/change this option
2108 as now bzImage can be compiled as a completely relocatable image
2109 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2110 address. This option is mainly useful for the folks who don't want
2111 to use a bzImage for capturing the crash dump and want to use a
2112 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2113 to be specifically compiled to run from a specific memory area
2114 (normally a reserved region) and this option comes handy.
2115
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002116 So if you are using bzImage for capturing the crash dump,
2117 leave the value here unchanged to 0x1000000 and set
2118 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2119 for capturing the crash dump change this value to start of
2120 the reserved region. In other words, it can be set based on
2121 the "X" value as specified in the "crashkernel=YM@XM"
2122 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002123 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002124 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002125
2126 Usage of bzImage for capturing the crash dump is recommended as
2127 one does not have to build two kernels. Same kernel can be used
2128 as production kernel and capture kernel. Above option should have
2129 gone away after relocatable bzImage support is introduced. But it
2130 is present because there are users out there who continue to use
2131 vmlinux for dump capture. This option should go away down the
2132 line.
2133
2134 Don't change this unless you know what you are doing.
2135
2136config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002137 bool "Build a relocatable kernel"
2138 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002139 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002140 This builds a kernel image that retains relocation information
2141 so it can be loaded someplace besides the default 1MB.
2142 The relocations tend to make the kernel binary about 10% larger,
2143 but are discarded at runtime.
2144
2145 One use is for the kexec on panic case where the recovery kernel
2146 must live at a different physical address than the primary
2147 kernel.
2148
2149 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2150 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002151 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002152
Kees Cook8ab38202013-10-10 17:18:14 -07002153config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002154 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002155 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002156 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002157 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002158 In support of Kernel Address Space Layout Randomization (KASLR),
2159 this randomizes the physical address at which the kernel image
2160 is decompressed and the virtual address where the kernel
2161 image is mapped, as a security feature that deters exploit
2162 attempts relying on knowledge of the location of kernel
2163 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002164
Kees Cooked9f0072016-05-25 15:45:33 -07002165 On 64-bit, the kernel physical and virtual addresses are
2166 randomized separately. The physical address will be anywhere
2167 between 16MB and the top of physical memory (up to 64TB). The
2168 virtual address will be randomized from 16MB up to 1GB (9 bits
2169 of entropy). Note that this also reduces the memory space
2170 available to kernel modules from 1.5GB to 1GB.
2171
2172 On 32-bit, the kernel physical and virtual addresses are
2173 randomized together. They will be randomized from 16MB up to
2174 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002175
Baoquan Hee8581e32016-04-20 13:55:43 -07002176 Entropy is generated using the RDRAND instruction if it is
2177 supported. If RDTSC is supported, its value is mixed into
2178 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002179 supported, then entropy is read from the i8254 timer. The
2180 usable entropy is limited by the kernel being built using
2181 2GB addressing, and that PHYSICAL_ALIGN must be at a
2182 minimum of 2MB. As a result, only 10 bits of entropy are
2183 theoretically possible, but the implementations are further
2184 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002185
Ingo Molnar6807c842017-04-18 11:08:12 +02002186 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002187
2188# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002189config X86_NEED_RELOCS
2190 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002191 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002192
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002193config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002194 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002195 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002196 range 0x2000 0x1000000 if X86_32
2197 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002198 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002199 This value puts the alignment restrictions on physical address
2200 where kernel is loaded and run from. Kernel is compiled for an
2201 address which meets above alignment restriction.
2202
2203 If bootloader loads the kernel at a non-aligned address and
2204 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2205 address aligned to above value and run from there.
2206
2207 If bootloader loads the kernel at a non-aligned address and
2208 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2209 load address and decompress itself to the address it has been
2210 compiled for and run from there. The address for which kernel is
2211 compiled already meets above alignment restrictions. Hence the
2212 end result is that kernel runs from a physical address meeting
2213 above alignment restrictions.
2214
Kees Cooka0215062013-07-08 09:15:17 -07002215 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2216 this value must be a multiple of 0x200000.
2217
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002218 Don't change this unless you know what you are doing.
2219
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002220config DYNAMIC_MEMORY_LAYOUT
2221 bool
2222 ---help---
2223 This option makes base addresses of vmalloc and vmemmap as well as
2224 __PAGE_OFFSET movable during boot.
2225
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002226config RANDOMIZE_MEMORY
2227 bool "Randomize the kernel memory sections"
2228 depends on X86_64
2229 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002230 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002231 default RANDOMIZE_BASE
2232 ---help---
2233 Randomizes the base virtual address of kernel memory sections
2234 (physical memory mapping, vmalloc & vmemmap). This security feature
2235 makes exploits relying on predictable memory locations less reliable.
2236
2237 The order of allocations remains unchanged. Entropy is generated in
2238 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2239 configuration have in average 30,000 different possible virtual
2240 addresses for each memory section.
2241
Ingo Molnar6807c842017-04-18 11:08:12 +02002242 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002243
Thomas Garnier90397a42016-06-21 17:47:06 -07002244config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2245 hex "Physical memory mapping padding" if EXPERT
2246 depends on RANDOMIZE_MEMORY
2247 default "0xa" if MEMORY_HOTPLUG
2248 default "0x0"
2249 range 0x1 0x40 if MEMORY_HOTPLUG
2250 range 0x0 0x40
2251 ---help---
2252 Define the padding in terabytes added to the existing physical
2253 memory size during kernel memory randomization. It is useful
2254 for memory hotplug support but reduces the entropy available for
2255 address randomization.
2256
2257 If unsure, leave at the default value.
2258
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002259config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002260 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002261 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002262
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002263config BOOTPARAM_HOTPLUG_CPU0
2264 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002265 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002266 ---help---
2267 Set whether default state of cpu0_hotpluggable is on or off.
2268
2269 Say Y here to enable CPU0 hotplug by default. If this switch
2270 is turned on, there is no need to give cpu0_hotplug kernel
2271 parameter and the CPU0 hotplug feature is enabled by default.
2272
2273 Please note: there are two known CPU0 dependencies if you want
2274 to enable the CPU0 hotplug feature either by this switch or by
2275 cpu0_hotplug kernel parameter.
2276
2277 First, resume from hibernate or suspend always starts from CPU0.
2278 So hibernate and suspend are prevented if CPU0 is offline.
2279
2280 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2281 offline if any interrupt can not migrate out of CPU0. There may
2282 be other CPU0 dependencies.
2283
2284 Please make sure the dependencies are under your control before
2285 you enable this feature.
2286
2287 Say N if you don't want to enable CPU0 hotplug feature by default.
2288 You still can enable the CPU0 hotplug feature at boot by kernel
2289 parameter cpu0_hotplug.
2290
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002291config DEBUG_HOTPLUG_CPU0
2292 def_bool n
2293 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002294 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002295 ---help---
2296 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2297 soon as possible and boots up userspace with CPU0 offlined. User
2298 can online CPU0 back after boot time.
2299
2300 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2301 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2302 compilation or giving cpu0_hotplug kernel parameter at boot.
2303
2304 If unsure, say N.
2305
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002306config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002307 def_bool n
2308 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002309 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002310 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002311 Certain buggy versions of glibc will crash if they are
2312 presented with a 32-bit vDSO that is not mapped at the address
2313 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002314
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002315 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2316 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2317 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2318 the only released version with the bug, but OpenSUSE 9
2319 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002320
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002321 The symptom of the bug is that everything crashes on startup, saying:
2322 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2323
2324 Saying Y here changes the default value of the vdso32 boot
2325 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2326 This works around the glibc bug but hurts performance.
2327
2328 If unsure, say N: if you are compiling your own kernel, you
2329 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002330
Kees Cook3dc33bd2015-08-12 17:55:19 -07002331choice
2332 prompt "vsyscall table for legacy applications"
2333 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002334 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002335 help
2336 Legacy user code that does not know how to find the vDSO expects
2337 to be able to issue three syscalls by calling fixed addresses in
2338 kernel space. Since this location is not randomized with ASLR,
2339 it can be used to assist security vulnerability exploitation.
2340
2341 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002342 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002343
2344 On a system with recent enough glibc (2.14 or newer) and no
2345 static binaries, you can say None without a performance penalty
2346 to improve security.
2347
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002348 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002349
Kees Cook3dc33bd2015-08-12 17:55:19 -07002350 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002351 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002352 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002353 The kernel traps and emulates calls into the fixed vsyscall
2354 address mapping. This makes the mapping non-executable, but
2355 it still contains readable known contents, which could be
2356 used in certain rare security vulnerability exploits. This
2357 configuration is recommended when using legacy userspace
2358 that still uses vsyscalls along with legacy binary
2359 instrumentation tools that require code to be readable.
2360
2361 An example of this type of legacy userspace is running
2362 Pin on an old binary that still uses vsyscalls.
2363
2364 config LEGACY_VSYSCALL_XONLY
2365 bool "Emulate execution only"
2366 help
2367 The kernel traps and emulates calls into the fixed vsyscall
2368 address mapping and does not allow reads. This
2369 configuration is recommended when userspace might use the
2370 legacy vsyscall area but support for legacy binary
2371 instrumentation of legacy code is not needed. It mitigates
2372 certain uses of the vsyscall area as an ASLR-bypassing
2373 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002374
2375 config LEGACY_VSYSCALL_NONE
2376 bool "None"
2377 help
2378 There will be no vsyscall mapping at all. This will
2379 eliminate any risk of ASLR bypass due to the vsyscall
2380 fixed address mapping. Attempts to use the vsyscalls
2381 will be reported to dmesg, so that either old or
2382 malicious userspace programs can be identified.
2383
2384endchoice
2385
Tim Bird516cbf32008-08-12 12:52:36 -07002386config CMDLINE_BOOL
2387 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002388 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002389 Allow for specifying boot arguments to the kernel at
2390 build time. On some systems (e.g. embedded ones), it is
2391 necessary or convenient to provide some or all of the
2392 kernel boot arguments with the kernel itself (that is,
2393 to not rely on the boot loader to provide them.)
2394
2395 To compile command line arguments into the kernel,
2396 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002397 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002398
2399 Systems with fully functional boot loaders (i.e. non-embedded)
2400 should leave this option set to 'N'.
2401
2402config CMDLINE
2403 string "Built-in kernel command string"
2404 depends on CMDLINE_BOOL
2405 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002406 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002407 Enter arguments here that should be compiled into the kernel
2408 image and used at boot time. If the boot loader provides a
2409 command line at boot time, it is appended to this string to
2410 form the full kernel command line, when the system boots.
2411
2412 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2413 change this behavior.
2414
2415 In most cases, the command line (whether built-in or provided
2416 by the boot loader) should specify the device for the root
2417 file system.
2418
2419config CMDLINE_OVERRIDE
2420 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002421 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002422 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002423 Set this option to 'Y' to have the kernel ignore the boot loader
2424 command line, and use ONLY the built-in command line.
2425
2426 This is used to work around broken boot loaders. This should
2427 be set to 'N' under normal conditions.
2428
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002429config MODIFY_LDT_SYSCALL
2430 bool "Enable the LDT (local descriptor table)" if EXPERT
2431 default y
2432 ---help---
2433 Linux can allow user programs to install a per-process x86
2434 Local Descriptor Table (LDT) using the modify_ldt(2) system
2435 call. This is required to run 16-bit or segmented code such as
2436 DOSEMU or some Wine programs. It is also used by some very old
2437 threading libraries.
2438
2439 Enabling this feature adds a small amount of overhead to
2440 context switches and increases the low-level kernel attack
2441 surface. Disabling it removes the modify_ldt(2) system call.
2442
2443 Saying 'N' here may make sense for embedded or server kernels.
2444
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002445source "kernel/livepatch/Kconfig"
2446
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002447endmenu
2448
Michal Hocko3072e412017-09-08 16:11:39 -07002449config ARCH_HAS_ADD_PAGES
2450 def_bool y
2451 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2452
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002453config ARCH_ENABLE_MEMORY_HOTPLUG
2454 def_bool y
2455 depends on X86_64 || (X86_32 && HIGHMEM)
2456
Gary Hade35551052008-10-31 10:52:03 -07002457config ARCH_ENABLE_MEMORY_HOTREMOVE
2458 def_bool y
2459 depends on MEMORY_HOTPLUG
2460
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002461config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002462 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002463 depends on NUMA
2464
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002465config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2466 def_bool y
2467 depends on X86_64 || X86_PAE
2468
Naoya Horiguchic177c812014-06-04 16:05:35 -07002469config ARCH_ENABLE_HUGEPAGE_MIGRATION
2470 def_bool y
2471 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2472
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002473config ARCH_ENABLE_THP_MIGRATION
2474 def_bool y
2475 depends on X86_64 && TRANSPARENT_HUGEPAGE
2476
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002477menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002478
2479config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002480 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002481 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002482
2483source "kernel/power/Kconfig"
2484
2485source "drivers/acpi/Kconfig"
2486
Feng Tangefafc8b2009-08-14 15:23:29 -04002487source "drivers/sfi/Kconfig"
2488
Andi Kleena6b68072008-01-30 13:32:49 +01002489config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002490 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002491 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002492
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493menuconfig APM
2494 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002495 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002496 ---help---
2497 APM is a BIOS specification for saving power using several different
2498 techniques. This is mostly useful for battery powered laptops with
2499 APM compliant BIOSes. If you say Y here, the system time will be
2500 reset after a RESUME operation, the /proc/apm device will provide
2501 battery status information, and user-space programs will receive
2502 notification of APM "events" (e.g. battery status change).
2503
2504 If you select "Y" here, you can disable actual use of the APM
2505 BIOS by passing the "apm=off" option to the kernel at boot time.
2506
2507 Note that the APM support is almost completely disabled for
2508 machines with more than one CPU.
2509
2510 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002511 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002512 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002513 <http://www.tldp.org/docs.html#howto>.
2514
2515 This driver does not spin down disk drives (see the hdparm(8)
2516 manpage ("man 8 hdparm") for that), and it doesn't turn off
2517 VESA-compliant "green" monitors.
2518
2519 This driver does not support the TI 4000M TravelMate and the ACER
2520 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2521 desktop machines also don't have compliant BIOSes, and this driver
2522 may cause those machines to panic during the boot phase.
2523
2524 Generally, if you don't have a battery in your machine, there isn't
2525 much point in using this driver and you should say N. If you get
2526 random kernel OOPSes or reboots that don't seem to be related to
2527 anything, try disabling/enabling this option (or disabling/enabling
2528 APM in your BIOS).
2529
2530 Some other things you should try when experiencing seemingly random,
2531 "weird" problems:
2532
2533 1) make sure that you have enough swap space and that it is
2534 enabled.
2535 2) pass the "no-hlt" option to the kernel
2536 3) switch on floating point emulation in the kernel and pass
2537 the "no387" option to the kernel
2538 4) pass the "floppy=nodma" option to the kernel
2539 5) pass the "mem=4M" option to the kernel (thereby disabling
2540 all but the first 4 MB of RAM)
2541 6) make sure that the CPU is not over clocked.
2542 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2543 8) disable the cache from your BIOS settings
2544 9) install a fan for the video card or exchange video RAM
2545 10) install a better fan for the CPU
2546 11) exchange RAM chips
2547 12) exchange the motherboard.
2548
2549 To compile this driver as a module, choose M here: the
2550 module will be called apm.
2551
2552if APM
2553
2554config APM_IGNORE_USER_SUSPEND
2555 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002556 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002557 This option will ignore USER SUSPEND requests. On machines with a
2558 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2559 series notebooks, it is necessary to say Y because of a BIOS bug.
2560
2561config APM_DO_ENABLE
2562 bool "Enable PM at boot time"
2563 ---help---
2564 Enable APM features at boot time. From page 36 of the APM BIOS
2565 specification: "When disabled, the APM BIOS does not automatically
2566 power manage devices, enter the Standby State, enter the Suspend
2567 State, or take power saving steps in response to CPU Idle calls."
2568 This driver will make CPU Idle calls when Linux is idle (unless this
2569 feature is turned off -- see "Do CPU IDLE calls", below). This
2570 should always save battery power, but more complicated APM features
2571 will be dependent on your BIOS implementation. You may need to turn
2572 this option off if your computer hangs at boot time when using APM
2573 support, or if it beeps continuously instead of suspending. Turn
2574 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2575 T400CDT. This is off by default since most machines do fine without
2576 this feature.
2577
2578config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002579 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002580 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002581 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002582 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2583 On some machines, this can activate improved power savings, such as
2584 a slowed CPU clock rate, when the machine is idle. These idle calls
2585 are made after the idle loop has run for some length of time (e.g.,
2586 333 mS). On some machines, this will cause a hang at boot time or
2587 whenever the CPU becomes idle. (On machines with more than one CPU,
2588 this option does nothing.)
2589
2590config APM_DISPLAY_BLANK
2591 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002592 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002593 Enable console blanking using the APM. Some laptops can use this to
2594 turn off the LCD backlight when the screen blanker of the Linux
2595 virtual console blanks the screen. Note that this is only used by
2596 the virtual console screen blanker, and won't turn off the backlight
2597 when using the X Window system. This also doesn't have anything to
2598 do with your VESA-compliant power-saving monitor. Further, this
2599 option doesn't work for all laptops -- it might not turn off your
2600 backlight at all, or it might print a lot of errors to the console,
2601 especially if you are using gpm.
2602
2603config APM_ALLOW_INTS
2604 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002605 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606 Normally we disable external interrupts while we are making calls to
2607 the APM BIOS as a measure to lessen the effects of a badly behaving
2608 BIOS implementation. The BIOS should reenable interrupts if it
2609 needs to. Unfortunately, some BIOSes do not -- especially those in
2610 many of the newer IBM Thinkpads. If you experience hangs when you
2611 suspend, try setting this to Y. Otherwise, say N.
2612
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002613endif # APM
2614
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002615source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002616
2617source "drivers/cpuidle/Kconfig"
2618
Andy Henroid27471fd2008-10-09 11:45:22 -07002619source "drivers/idle/Kconfig"
2620
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002621endmenu
2622
2623
2624menu "Bus options (PCI etc.)"
2625
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002626choice
2627 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002628 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002629 default PCI_GOANY
2630 ---help---
2631 On PCI systems, the BIOS can be used to detect the PCI devices and
2632 determine their configuration. However, some old PCI motherboards
2633 have BIOS bugs and may crash if this is done. Also, some embedded
2634 PCI-based systems don't have any BIOS at all. Linux can also try to
2635 detect the PCI hardware directly without using the BIOS.
2636
2637 With this option, you can specify how Linux should detect the
2638 PCI devices. If you choose "BIOS", the BIOS will be used,
2639 if you choose "Direct", the BIOS won't be used, and if you
2640 choose "MMConfig", then PCI Express MMCONFIG will be used.
2641 If you choose "Any", the kernel will try MMCONFIG, then the
2642 direct access method and falls back to the BIOS if that doesn't
2643 work. If unsure, go with the default, which is "Any".
2644
2645config PCI_GOBIOS
2646 bool "BIOS"
2647
2648config PCI_GOMMCONFIG
2649 bool "MMConfig"
2650
2651config PCI_GODIRECT
2652 bool "Direct"
2653
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002654config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002655 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002656 depends on OLPC
2657
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002658config PCI_GOANY
2659 bool "Any"
2660
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002661endchoice
2662
2663config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002664 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002665 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002666
2667# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2668config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002669 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002670 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002671
2672config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002673 bool "Support mmconfig PCI config space access" if X86_64
2674 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002675 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002676 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002677
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002678config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002679 def_bool y
2680 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002681
Alex Nixonb5401a92010-03-18 16:31:34 -04002682config PCI_XEN
2683 def_bool y
2684 depends on PCI && XEN
2685 select SWIOTLB_XEN
2686
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002687config MMCONF_FAM10H
2688 def_bool y
2689 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002690
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002691config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002692 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002693 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002694 help
2695 Read the PCI windows out of the CNB20LE host bridge. This allows
2696 PCI hotplug to work on systems with the CNB20LE chipset which do
2697 not have ACPI.
2698
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002699 There's no public spec for this chipset, and this functionality
2700 is known to be incomplete.
2701
2702 You should say N unless you know you need this.
2703
William Breathitt Gray3a495512016-05-27 18:08:27 -04002704config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002705 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002706 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002707 Expose ISA bus device drivers and options available for selection and
2708 configuration. Enable this option if your target machine has an ISA
2709 bus. ISA is an older system, displaced by PCI and newer bus
2710 architectures -- if your target machine is modern, it probably does
2711 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002712
2713 If unsure, say N.
2714
David Rientjes1c00f012011-03-22 16:34:59 -07002715# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002716config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002717 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2718 default y
2719 help
2720 Enables ISA-style DMA support for devices requiring such controllers.
2721 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002722
Linus Torvalds51e68d02016-05-21 10:25:19 -07002723if X86_32
2724
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002725config ISA
2726 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002727 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728 Find out whether you have ISA slots on your motherboard. ISA is the
2729 name of a bus system, i.e. the way the CPU talks to the other stuff
2730 inside your box. Other bus systems are PCI, EISA, MicroChannel
2731 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2732 newer boards don't support it. If you have ISA, say Y, otherwise N.
2733
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002734config SCx200
2735 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002736 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002737 This provides basic support for National Semiconductor's
2738 (now AMD's) Geode processors. The driver probes for the
2739 PCI-IDs of several on-chip devices, so its a good dependency
2740 for other scx200_* drivers.
2741
2742 If compiled as a module, the driver is named scx200.
2743
2744config SCx200HR_TIMER
2745 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002746 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002747 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002748 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002749 This driver provides a clocksource built upon the on-chip
2750 27MHz high-resolution timer. Its also a workaround for
2751 NSC Geode SC-1100's buggy TSC, which loses time when the
2752 processor goes idle (as is done by the scheduler). The
2753 other workaround is idle=poll boot option.
2754
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002755config OLPC
2756 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002757 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002758 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002759 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002760 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002761 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002762 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002763 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002764 Add support for detecting the unique features of the OLPC
2765 XO hardware.
2766
Daniel Drakea3128582011-06-25 17:34:10 +01002767config OLPC_XO1_PM
2768 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002769 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002770 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002771 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002772
Daniel Drakecfee9592011-06-25 17:34:17 +01002773config OLPC_XO1_RTC
2774 bool "OLPC XO-1 Real Time Clock"
2775 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2776 ---help---
2777 Add support for the XO-1 real time clock, which can be used as a
2778 programmable wakeup source.
2779
Daniel Drake7feda8e2011-06-25 17:34:12 +01002780config OLPC_XO1_SCI
2781 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002782 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002783 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002784 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002785 ---help---
2786 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002787 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002788 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002789 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002790 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002791 - AC adapter status updates
2792 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002793
Daniel Drakea0f30f52011-06-25 17:34:18 +01002794config OLPC_XO15_SCI
2795 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002796 depends on OLPC && ACPI
2797 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002798 ---help---
2799 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2800 - EC-driven system wakeups
2801 - AC adapter status updates
2802 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002803
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002804config ALIX
2805 bool "PCEngines ALIX System Support (LED setup)"
2806 select GPIOLIB
2807 ---help---
2808 This option enables system support for the PCEngines ALIX.
2809 At present this just sets up LEDs for GPIO control on
2810 ALIX2/3/6 boards. However, other system specific setup should
2811 get added here.
2812
2813 Note: You must still enable the drivers for GPIO and LED support
2814 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2815
2816 Note: You have to set alix.force=1 for boards with Award BIOS.
2817
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002818config NET5501
2819 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2820 select GPIOLIB
2821 ---help---
2822 This option enables system support for the Soekris Engineering net5501.
2823
Philip A. Prindeville31970592012-01-14 01:45:39 -07002824config GEOS
2825 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2826 select GPIOLIB
2827 depends on DMI
2828 ---help---
2829 This option enables system support for the Traverse Technologies GEOS.
2830
Vivien Didelot7d029122013-01-04 16:18:14 -05002831config TS5500
2832 bool "Technologic Systems TS-5500 platform support"
2833 depends on MELAN
2834 select CHECK_SIGNATURE
2835 select NEW_LEDS
2836 select LEDS_CLASS
2837 ---help---
2838 This option enables system support for the Technologic Systems TS-5500.
2839
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002840endif # X86_32
2841
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002842config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002843 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002844 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002845
David Herrmanne3263ab2013-08-02 14:05:22 +02002846config X86_SYSFB
2847 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2848 help
2849 Firmwares often provide initial graphics framebuffers so the BIOS,
2850 bootloader or kernel can show basic video-output during boot for
2851 user-guidance and debugging. Historically, x86 used the VESA BIOS
2852 Extensions and EFI-framebuffers for this, which are mostly limited
2853 to x86.
2854 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2855 framebuffers so the new generic system-framebuffer drivers can be
2856 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002857 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002858 drivers like efifb, vesafb and uvesafb can pick it up.
2859 If this option is not selected, all system framebuffers are always
2860 marked as fallback platform framebuffers as usual.
2861
2862 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2863 not be able to pick up generic system framebuffers if this option
2864 is selected. You are highly encouraged to enable simplefb as
2865 replacement if you select this option. simplefb can correctly deal
2866 with generic system framebuffers. But you should still keep vesafb
2867 and others enabled as fallback if a system framebuffer is
2868 incompatible with simplefb.
2869
2870 If unsure, say Y.
2871
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002872endmenu
2873
2874
Christoph Hellwig15724972018-07-31 13:39:30 +02002875menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002876
2877config IA32_EMULATION
2878 bool "IA32 Emulation"
2879 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002880 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002881 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002882 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002883 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002884 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002885 Include code to run legacy 32-bit programs under a
2886 64-bit kernel. You should likely turn this on, unless you're
2887 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002888
2889config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002890 tristate "IA32 a.out support"
2891 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002892 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002893 ---help---
2894 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002895
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002896config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002897 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002898 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002899 ---help---
2900 Include code to run binaries for the x32 native 32-bit ABI
2901 for 64-bit processors. An x32 process gets access to the
2902 full 64-bit register file and wide data path while leaving
2903 pointers at 32 bits for smaller memory footprint.
2904
2905 You will need a recent binutils (2.22 or later) with
2906 elf32_x86_64 support enabled to compile a kernel with this
2907 option set.
2908
Ingo Molnar953fee12016-11-15 10:22:52 +01002909config COMPAT_32
2910 def_bool y
2911 depends on IA32_EMULATION || X86_32
2912 select HAVE_UID16
2913 select OLD_SIGSUSPEND3
2914
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002915config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002916 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002917 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002918
Jan Beulich3120e252012-09-10 12:41:45 +01002919if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002920config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002921 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002922
2923config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002924 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002925 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002926endif
David Howellsee009e4a02011-03-07 15:06:20 +00002927
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002928endmenu
2929
2930
Keith Packarde5beae12008-11-03 18:21:45 +01002931config HAVE_ATOMIC_IOMAP
2932 def_bool y
2933 depends on X86_32
2934
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002935source "drivers/firmware/Kconfig"
2936
Avi Kivityedf88412007-12-16 11:02:48 +02002937source "arch/x86/kvm/Kconfig"