blob: 5534b4335802ef481df997d6c779962450d0b2ad [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
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010033
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040034config FORCE_DYNAMIC_FTRACE
35 def_bool y
36 depends on X86_32
37 depends on FUNCTION_TRACER
38 select DYNAMIC_FTRACE
39 help
40 We keep the static function tracing (!DYNAMIC_FTRACE) around
41 in order to test the non static function tracing in the
42 generic code, as other architectures still use it. But we
43 only need to keep it around for x86_64. No need to keep it
44 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010045#
46# Arch settings
47#
48# ( Note that options that are marked 'if X86_64' could in principle be
49# ported to 32-bit as well. )
50#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010051config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010052 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010053 #
54 # Note: keep this list sorted alphabetically
55 #
Ingo Molnar6471b822015-06-03 10:00:13 +020056 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
57 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030058 select ARCH_32BIT_OFF_T if X86_32
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020059 select ARCH_CLOCKSOURCE_INIT
Ingo Molnarc763ea22016-11-15 10:26:39 +010060 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080061 select ARCH_HAS_DEBUG_VIRTUAL
Dan Williams21266be2015-11-19 18:19:29 -080062 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070064 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070065 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070066 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080067 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070068 select ARCH_HAS_KCOV if X86_64
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030069 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050070 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Daniel Borkmann0ebeea82020-05-15 12:11:16 +020071 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Ingo Molnarc763ea22016-11-15 10:26:39 +010072 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070073 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070074 select ARCH_HAS_PTE_SPECIAL
Dan Williams0aed55a2017-05-29 12:22:50 -070075 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070076 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010077 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070078 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080079 select ARCH_HAS_STRICT_KERNEL_RWX
80 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050081 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Brian Gerst25c619e2020-03-13 15:51:42 -040082 select ARCH_HAS_SYSCALL_WRAPPER
Andrey Ryabininc6d30852016-01-20 15:00:55 -080083 select ARCH_HAS_UBSAN_SANITIZE_ALL
Zong Li7e01ccb2020-06-03 16:03:58 -070084 select ARCH_HAS_DEBUG_WX
Ingo Molnar6471b822015-06-03 10:00:13 +020085 select ARCH_HAVE_NMI_SAFE_CMPXCHG
86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040087 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080088 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020089 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020090 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020092 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
93 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select ARCH_USE_QUEUED_RWLOCKS
95 select ARCH_USE_QUEUED_SPINLOCKS
Mark Brown2ce0d7f2020-04-16 19:24:02 +010096 select ARCH_USE_SYM_ANNOTATIONS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070097 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Daniel Borkmann81c22042019-12-09 16:08:03 +010098 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +010099 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700100 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -0700101 select ARCH_WANTS_THP_SWAP if X86_64
Shile Zhang10916702019-12-04 08:46:31 +0800102 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200103 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
105 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700107 select EDAC_ATOMIC_SCRUB
108 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200109 select GENERIC_CLOCKEVENTS
110 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
111 select GENERIC_CLOCKEVENTS_MIN_ADJUST
112 select GENERIC_CMOS_UPDATE
113 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100114 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200115 select GENERIC_EARLY_IOREMAP
116 select GENERIC_FIND_FIRST_BIT
117 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200118 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200119 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200120 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200121 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200122 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200123 select GENERIC_IRQ_SHOW
124 select GENERIC_PENDING_IRQ if SMP
Steven Price2ae27132020-02-03 17:36:24 -0800125 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200126 select GENERIC_SMP_IDLE_THREAD
127 select GENERIC_STRNCPY_FROM_USER
128 select GENERIC_STRNLEN_USER
129 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100130 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000131 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700132 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Hans de Goede17e58882020-01-23 22:02:42 +0100133 select HARDIRQS_SW_RESEND
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200134 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200135 select HAVE_ACPI_APEI if ACPI
136 select HAVE_ACPI_APEI_NMI if ACPI
137 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select HAVE_ARCH_AUDITSYSCALL
139 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
140 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700141 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800142 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800143 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800145 select HAVE_ARCH_MMAP_RND_BITS if MMU
146 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300147 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700148 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200149 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700150 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300151 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select HAVE_ARCH_TRACEHOOK
153 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800154 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Peter Xub64d8d12020-04-20 18:13:45 -0700155 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700156 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100157 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900158 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200159 select HAVE_CMPXCHG_DOUBLE
160 select HAVE_CMPXCHG_LOCAL
161 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700162 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200163 select HAVE_C_RECORDMCOUNT
164 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700165 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400166 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900167 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500168 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800169 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700170 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100171 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700172 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700173 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400174 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200175 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200176 select HAVE_FUNCTION_GRAPH_TRACER
177 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200178 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530179 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200180 select HAVE_IDE
181 select HAVE_IOREMAP_PROT
182 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
183 select HAVE_IRQ_TIME_ACCOUNTING
184 select HAVE_KERNEL_BZIP2
185 select HAVE_KERNEL_GZIP
186 select HAVE_KERNEL_LZ4
187 select HAVE_KERNEL_LZMA
188 select HAVE_KERNEL_LZO
189 select HAVE_KERNEL_XZ
190 select HAVE_KPROBES
191 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900192 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200193 select HAVE_KRETPROBES
194 select HAVE_KVM
195 select HAVE_LIVEPATCH if X86_64
Frederic Weisbecker01027522010-04-11 18:55:56 +0200196 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500197 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800198 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700199 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200200 select HAVE_OPROFILE
201 select HAVE_OPTPROBES
202 select HAVE_PCSPKR_PLATFORM
203 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200204 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700205 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100206 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200207 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200208 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800209 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200210 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200211 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900212 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900213 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100214 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400215 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200216 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200217 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300218 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100219 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200220 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100221 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200222 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100223 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000224 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200225 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500226 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200227 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200228 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500229 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200230 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700231 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200232 select USER_STACKTRACE_SUPPORT
233 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200234 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800235 select PROC_PID_ARCH_STATUS if PROC_FS
Nayna Jain9e2b4be2020-03-08 20:57:51 -0400236 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
Balbir Singh7d8330a2008-02-10 12:46:28 +0530237
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200238config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100239 def_bool y
240 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200241
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700242config OUTPUT_FORMAT
243 string
244 default "elf32-i386" if X86_32
245 default "elf64-x86-64" if X86_64
246
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100247config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100248 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100249
250config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100251 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100252
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100254 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100255
Daniel Cashman9e08f572016-01-14 15:20:06 -0800256config ARCH_MMAP_RND_BITS_MIN
257 default 28 if 64BIT
258 default 8
259
260config ARCH_MMAP_RND_BITS_MAX
261 default 32 if 64BIT
262 default 16
263
264config ARCH_MMAP_RND_COMPAT_BITS_MIN
265 default 8
266
267config ARCH_MMAP_RND_COMPAT_BITS_MAX
268 default 16
269
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100270config SBUS
271 bool
272
273config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100274 def_bool y
275 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100276
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100277config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100278 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100279 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000280 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
281
282config GENERIC_BUG_RELATIVE_POINTERS
283 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100284
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100285config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100286 def_bool y
287 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100288
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100289config GENERIC_CALIBRATE_DELAY
290 def_bool y
291
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800292config ARCH_HAS_CPU_RELAX
293 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100294
Pekka Enberg1b27d052008-04-28 02:12:22 -0700295config ARCH_HAS_CACHE_LINE_SIZE
296 def_bool y
297
Dave Hansen316d0972018-04-20 15:20:28 -0700298config ARCH_HAS_FILTER_PGPROT
299 def_bool y
300
Mike Travisdd5af902008-01-30 13:33:32 +0100301config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900302 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100303
Tejun Heo08fc4582009-08-14 15:00:49 +0900304config NEED_PER_CPU_EMBED_FIRST_CHUNK
305 def_bool y
306
307config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900308 def_bool y
309
Johannes Berg801e4062007-12-08 02:12:39 +0100310config ARCH_HIBERNATION_POSSIBLE
311 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100312
Johannes Bergf4cb5702007-12-08 02:14:00 +0100313config ARCH_SUSPEND_POSSIBLE
314 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100315
Steve Capper53313b22013-04-30 08:03:42 +0100316config ARCH_WANT_GENERAL_HUGETLB
317 def_bool y
318
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100319config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000320 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100322config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000323 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100324
Akinobu Mita6a11f752009-03-31 15:23:17 -0700325config ARCH_SUPPORTS_DEBUG_PAGEALLOC
326 def_bool y
327
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300328config KASAN_SHADOW_OFFSET
329 hex
330 depends on KASAN
331 default 0xdffffc0000000000
332
Shane Wang69575d32009-09-01 18:25:07 -0700333config HAVE_INTEL_TXT
334 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700335 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700336
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100337config X86_32_SMP
338 def_bool y
339 depends on X86_32 && SMP
340
341config X86_64_SMP
342 def_bool y
343 depends on X86_64 && SMP
344
Tejun Heoccbeed32009-02-09 22:17:40 +0900345config X86_32_LAZY_GS
346 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900347 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900348
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530349config ARCH_SUPPORTS_UPROBES
350 def_bool y
351
Rob Herringd20642f2014-04-18 17:19:54 -0500352config FIX_EARLYCON_MEM
353 def_bool y
354
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300355config DYNAMIC_PHYSICAL_MASK
356 bool
357
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700358config PGTABLE_LEVELS
359 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300360 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700361 default 4 if X86_64
362 default 3 if X86_PAE
363 default 2
364
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900365config CC_HAS_SANE_STACKPROTECTOR
366 bool
367 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
368 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
369 help
370 We have to make sure stack protector is unconditionally disabled if
371 the compiler produces broken code.
372
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100373menu "Processor type and features"
374
Randy Dunlap5ee71532012-01-16 11:57:18 -0800375config ZONE_DMA
376 bool "DMA memory allocation support" if EXPERT
377 default y
378 help
379 DMA memory allocation support allows devices with less than 32-bit
380 addressing to allocate within the first 16MB of address space.
381 Disable if no such devices will be used.
382
383 If unsure, say Y.
384
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100385config SMP
386 bool "Symmetric multi-processing support"
387 ---help---
388 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800389 a system with only one CPU, say N. If you have a system with more
390 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100391
Robert Graffham4a474152014-01-23 15:55:29 -0800392 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100393 machines, but will use only one CPU of a multiprocessor machine. If
394 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800395 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100396 will run faster if you say N here.
397
398 Note that if you say Y here and choose architecture "586" or
399 "Pentium" under "Processor family", the kernel will not work on 486
400 architectures. Similarly, multiprocessor kernels for the "PPro"
401 architecture may not work on all Pentium based boards.
402
403 People using multiprocessor machines who say Y here should also say
404 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
405 Management" code will be disabled if you say Y here.
406
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300407 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300408 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100409 <http://www.tldp.org/docs.html#howto>.
410
411 If you don't know what to do here, say N.
412
Josh Triplett9def39be2013-10-30 08:09:45 -0700413config X86_FEATURE_NAMES
414 bool "Processor feature human-readable names" if EMBEDDED
415 default y
416 ---help---
417 This option compiles in a table of x86 feature bits and corresponding
418 names. This is required to support /proc/cpuinfo and a few kernel
419 messages. You can disable this to save space, at the expense of
420 making those few kernel messages show numeric feature bits instead.
421
422 If in doubt, say Y.
423
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800424config X86_X2APIC
425 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200426 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800427 ---help---
428 This enables x2apic support on CPUs that have this feature.
429
430 This allows 32-bit apic IDs (so it can support very large systems),
431 and accesses the local apic via MSRs not via mmio.
432
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800433 If you don't know what to do here, say N.
434
Yinghai Lu6695c852008-06-19 12:13:09 -0700435config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700436 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000437 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200438 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100439 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700440 For old smp systems that do not have proper acpi support. Newer systems
441 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700442
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000443config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100444 def_bool y
445 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000446
David Woodhouse76b04382018-01-11 21:46:25 +0000447config RETPOLINE
448 bool "Avoid speculative indirect branches in kernel"
449 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100450 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000451 help
452 Compile kernel with the retpoline compiler options to guard against
453 kernel-to-user data leaks by avoiding speculative indirect
454 branches. Requires a compiler with -mindirect-branch=thunk-extern
455 support for full protection. The kernel may run slower.
456
Johannes Weinere6d42932019-01-29 17:44:36 -0500457config X86_CPU_RESCTRL
458 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000459 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100460 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800461 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700462 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500463 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000464
465 Provide support for the allocation and monitoring of system resources
466 usage by the CPU.
467
468 Intel calls this Intel Resource Director Technology
469 (Intel(R) RDT). More information about RDT can be found in the
470 Intel x86 Architecture Software Developer Manual.
471
472 AMD calls this AMD Platform Quality of Service (AMD QoS).
473 More information about AMD QoS can be found in the AMD64 Technology
474 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700475
476 Say N if unsure.
477
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800478if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800479config X86_BIGSMP
480 bool "Support for big SMP systems with more than 8 CPUs"
481 depends on SMP
482 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -0800483 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800484
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800485config X86_EXTENDED_PLATFORM
486 bool "Support for extended (non-PC) x86 platforms"
487 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100488 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100489 If you disable this option then the kernel will only support
490 standard PC platforms. (which covers the vast majority of
491 systems out there.)
492
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800493 If you enable this option then you'll be able to select support
494 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100495 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800496 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800497 RDC R-321x SoC
498 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200499 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200500 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100501
502 If you have one of these systems, or if you want to build a
503 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800504endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100505
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800506if X86_64
507config X86_EXTENDED_PLATFORM
508 bool "Support for extended (non-PC) x86 platforms"
509 default y
510 ---help---
511 If you disable this option then the kernel will only support
512 standard PC platforms. (which covers the vast majority of
513 systems out there.)
514
515 If you enable this option then you'll be able to select support
516 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800517 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800518 ScaleMP vSMP
519 SGI Ultraviolet
520
521 If you have one of these systems, or if you want to build a
522 generic distribution kernel, say Y here - otherwise say N.
523endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800524# This is an alphabetically sorted list of 64 bit extended platforms
525# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800526config X86_NUMACHIP
527 bool "Numascale NumaChip"
528 depends on X86_64
529 depends on X86_EXTENDED_PLATFORM
530 depends on NUMA
531 depends on SMP
532 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700533 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800534 ---help---
535 Adds support for Numascale NumaChip large-SMP systems. Needed to
536 enable more than ~168 cores.
537 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100538
Ingo Molnar6a485652009-01-27 18:29:13 +0100539config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800540 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100541 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100542 select PARAVIRT
543 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800544 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300545 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100546 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100547 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
548 supposed to run on these EM64T-based machines. Only choose this option
549 if you have one of these machines.
550
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800551config X86_UV
552 bool "SGI Ultraviolet"
553 depends on X86_64
554 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500555 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800556 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700557 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200558 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800559 ---help---
560 This option is needed in order to support SGI Ultraviolet systems.
561 If you don't have one of these, you should say N here.
562
563# Following is an alphabetically sorted list of 32 bit extended platforms
564# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100565
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000566config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100567 bool "Goldfish (Virtual Platform)"
568 depends on X86_EXTENDED_PLATFORM
569 ---help---
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000570 Enable support for the Goldfish virtual platform used primarily
571 for Android development. Unless you are building for the Android
572 Goldfish emulator say N here.
573
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800574config X86_INTEL_CE
575 bool "CE4100 TV platform"
576 depends on PCI
577 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800578 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800579 depends on X86_32
580 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800581 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100582 select OF
583 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800584 ---help---
585 Select for the Intel CE media processor (CE4100) SOC.
586 This option compiles in support for the CE4100 SOC for settop
587 boxes and media devices.
588
David Cohen4cb9b002013-12-16 17:37:26 -0800589config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100590 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100591 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800592 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000593 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200594 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000595 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000596 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800597 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000598 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000599 select APB_TIMER
Mika Westerberg54b34aa2020-04-16 11:15:33 +0300600 select INTEL_SCU_PCI
Mika Westerberg15a713d2012-01-26 17:35:05 +0000601 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000602 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800603 Select to build a kernel capable of supporting Intel MID (Mobile
604 Internet Device) platform systems which do not have the PCI legacy
605 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000606
David Cohen4cb9b002013-12-16 17:37:26 -0800607 Intel MID platforms are based on an Intel processor and chipset which
608 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100609
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000610config X86_INTEL_QUARK
611 bool "Intel Quark platform support"
612 depends on X86_32
613 depends on X86_EXTENDED_PLATFORM
614 depends on X86_PLATFORM_DEVICES
615 depends on X86_TSC
616 depends on PCI
617 depends on PCI_GOANY
618 depends on X86_IO_APIC
619 select IOSF_MBI
620 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200621 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000622 ---help---
623 Select to include support for Quark X1000 SoC.
624 Say Y here if you have a Quark based system such as the Arduino
625 compatible Intel Galileo.
626
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000627config X86_INTEL_LPSS
628 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000629 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000630 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300631 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100632 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000633 ---help---
634 Select to build support for Intel Low Power Subsystem such as
635 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300636 things like clock tree (common clock framework) and pincontrol
637 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000638
Ken Xue92082a82015-02-06 08:27:51 +0800639config X86_AMD_PLATFORM_DEVICE
640 bool "AMD ACPI2Platform devices support"
641 depends on ACPI
642 select COMMON_CLK
643 select PINCTRL
644 ---help---
645 Select to interpret AMD specific ACPI device to platform device
646 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
647 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
648 implemented under PINCTRL subsystem.
649
David E. Boxced3ce72014-09-17 22:13:50 -0700650config IOSF_MBI
651 tristate "Intel SoC IOSF Sideband support for SoC platforms"
652 depends on PCI
653 ---help---
654 This option enables sideband register access support for Intel SoC
655 platforms. On these platforms the IOSF sideband is used in lieu of
656 MSR's for some register accesses, mostly but not limited to thermal
657 and power. Drivers may query the availability of this device to
658 determine if they need the sideband in order to work on these
659 platforms. The sideband is available on the following SoC products.
660 This list is not meant to be exclusive.
661 - BayTrail
662 - Braswell
663 - Quark
664
665 You should say Y if you are running a kernel on one of these SoC's.
666
David E. Boxed2226b2014-09-17 22:13:51 -0700667config IOSF_MBI_DEBUG
668 bool "Enable IOSF sideband access through debugfs"
669 depends on IOSF_MBI && DEBUG_FS
670 ---help---
671 Select this option to expose the IOSF sideband access registers (MCR,
672 MDR, MCRX) through debugfs to write and read register information from
673 different units on the SoC. This is most useful for obtaining device
674 state information for debug and analysis. As this is a general access
675 mechanism, users of this option would have specific knowledge of the
676 device they want to access.
677
678 If you don't require the option or are in doubt, say N.
679
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800680config X86_RDC321X
681 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100682 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800683 depends on X86_EXTENDED_PLATFORM
684 select M486
685 select X86_REBOOTFIXUPS
686 ---help---
687 This option is needed for RDC R-321x system-on-chip, also known
688 as R-8610-(G).
689 If you don't have one of these chips, you should say N here.
690
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100691config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100692 bool "Support non-standard 32-bit SMP architectures"
693 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800694 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100695 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800696 This option compiles in the bigsmp and STA2X11 default
697 subarchitectures. It is intended for a generic binary
698 kernel. If you select them all, kernel will probe it one by
699 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700700
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800701# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700702
Linus Torvaldsd949f362009-09-26 09:35:07 -0700703config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100704 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700705 # MCE code calls memory_failure():
706 depends on X86_MCE
707 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700708 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
709 depends on X86_64 || !SPARSEMEM
710 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700711
Alessandro Rubini83125a32012-04-04 19:40:21 +0200712config STA2X11
713 bool "STA2X11 Companion Chip Support"
714 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200715 select SWIOTLB
716 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200717 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200718 ---help---
719 This adds support for boards based on the STA2X11 IO-Hub,
720 a.k.a. "ConneXt". The chip is used in place of the standard
721 PC chipset, so all "standard" peripherals are missing. If this
722 option is selected the kernel will still be able to boot on
723 standard PC machines.
724
Shérab82148d12010-09-25 06:06:57 +0200725config X86_32_IRIS
726 tristate "Eurobraille/Iris poweroff module"
727 depends on X86_32
728 ---help---
729 The Iris machines from EuroBraille do not have APM or ACPI support
730 to shut themselves down properly. A special I/O sequence is
731 needed to do so, which is what this module does at
732 kernel shutdown.
733
734 This is only for Iris machines from EuroBraille.
735
736 If unused, say N.
737
Ingo Molnarae1e9132008-11-11 09:05:16 +0100738config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100739 def_bool y
740 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800741 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100742 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100743 Calculate simpler /proc/<PID>/wchan values. If this option
744 is disabled then wchan values will recurse back to the
745 caller function. This provides more accurate wchan values,
746 at the expense of slightly more scheduling overhead.
747
748 If in doubt, say "Y".
749
Borislav Petkov6276a072013-03-04 21:20:21 +0100750menuconfig HYPERVISOR_GUEST
751 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100752 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100753 Say Y here to enable options for running Linux under various hyper-
754 visors. This option enables basic hypervisor detection and platform
755 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100756
Borislav Petkov6276a072013-03-04 21:20:21 +0100757 If you say N, all options in this submenu will be skipped and
758 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100759
Borislav Petkov6276a072013-03-04 21:20:21 +0100760if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100761
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100762config PARAVIRT
763 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100764 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100765 This changes the kernel so it can modify itself when it is run
766 under a hypervisor, potentially improving performance significantly
767 over full virtualization. However, when run without a hypervisor
768 the kernel is theoretically slower and slightly larger.
769
Juergen Grossc00a2802018-08-28 09:40:21 +0200770config PARAVIRT_XXL
771 bool
772
Borislav Petkov6276a072013-03-04 21:20:21 +0100773config PARAVIRT_DEBUG
774 bool "paravirt-ops debugging"
775 depends on PARAVIRT && DEBUG_KERNEL
776 ---help---
777 Enable to debug paravirt_ops internals. Specifically, BUG if
778 a paravirt_op is missing when it is called.
779
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700780config PARAVIRT_SPINLOCKS
781 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700782 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700783 ---help---
784 Paravirtualized spinlocks allow a pvops backend to replace the
785 spinlock implementation with something virtualization-friendly
786 (for example, block the virtual CPU rather than spinning).
787
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530788 It has a minimal impact on native kernels and gives a nice performance
789 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700790
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530791 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700792
Zhao Yakuiecca25022019-04-30 11:45:23 +0800793config X86_HV_CALLBACK_VECTOR
794 def_bool n
795
Borislav Petkov6276a072013-03-04 21:20:21 +0100796source "arch/x86/xen/Kconfig"
797
798config KVM_GUEST
799 bool "KVM Guest support (including kvmclock)"
800 depends on PARAVIRT
801 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300802 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100803 default y
804 ---help---
805 This option enables various optimizations for running under the KVM
806 hypervisor. It includes a paravirtualized clock, so that instead
807 of relying on a PIT (or probably other) emulation by the
808 underlying device model, the host provides the guest with
809 timing infrastructure such as time of day, and system time
810
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300811config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100812 def_bool n
813 prompt "Disable host haltpoll when loading haltpoll driver"
814 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300815 If virtualized under KVM, disable host haltpoll.
816
Maran Wilson77336072018-12-10 11:07:28 -0800817config PVH
818 bool "Support for running PVH guests"
819 ---help---
820 This option enables the PVH entry point for guest virtual machines
821 as specified in the x86/HVM direct boot ABI.
822
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530823config KVM_DEBUG_FS
824 bool "Enable debug information for KVM Guests in debugfs"
825 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530826 ---help---
827 This option enables collection of various statistics for KVM guest.
828 Statistics are displayed in debugfs filesystem. Enabling this option
829 may incur significant overhead.
830
Borislav Petkov6276a072013-03-04 21:20:21 +0100831config PARAVIRT_TIME_ACCOUNTING
832 bool "Paravirtual steal time accounting"
833 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100834 ---help---
835 Select this option to enable fine granularity task steal time
836 accounting. Time spent executing other tasks in parallel with
837 the current vCPU is discounted from the vCPU power. To account for
838 that, there can be a small performance impact.
839
840 If in doubt, say N here.
841
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200842config PARAVIRT_CLOCK
843 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200844
Jan Kiszka4a362602017-11-27 09:11:46 +0100845config JAILHOUSE_GUEST
846 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100847 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100848 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100849 ---help---
850 This option allows to run Linux as guest in a Jailhouse non-root
851 cell. You can leave this option disabled if you only want to start
852 Jailhouse and run Linux afterwards in the root cell.
853
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800854config ACRN_GUEST
855 bool "ACRN Guest support"
856 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800857 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800858 help
859 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
860 a flexible, lightweight reference open-source hypervisor, built with
861 real-time and safety-criticality in mind. It is built for embedded
862 IOT with small footprint and real-time features. More details can be
863 found in https://projectacrn.org/.
864
Borislav Petkov6276a072013-03-04 21:20:21 +0100865endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400866
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100867source "arch/x86/Kconfig.cpu"
868
869config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100870 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100871 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100872 ---help---
873 Use the IA-PC HPET (High Precision Event Timer) to manage
874 time in preference to the PIT and RTC, if a HPET is
875 present.
876 HPET is the next generation timer replacing legacy 8254s.
877 The HPET provides a stable time base on SMP
878 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200879 as it is off-chip. The interface used is documented
880 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100881
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100882 You can safely choose Y here. However, HPET will only be
883 activated if the platform and the BIOS support this feature.
884 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100885
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100886 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100887
888config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100889 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800890 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100891
Jacob Panbb24c472009-09-02 07:37:17 -0700892config APB_TIMER
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100893 def_bool y if X86_INTEL_MID
894 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
895 select DW_APB_TIMER
896 depends on X86_INTEL_MID && SFI
897 help
898 APB timer is the replacement for 8254, HPET on X86 MID platforms.
899 The APBT provides a stable time base on SMP
900 systems, unlike the TSC, but it is more expensive to access,
901 as it is off-chip. APB timers are always running regardless of CPU
902 C states, they are used as per CPU clockevent device when possible.
Jacob Panbb24c472009-09-02 07:37:17 -0700903
David Rientjes6a108a12011-01-20 14:44:16 -0800904# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100905# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700906config DMI
907 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800908 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800909 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100910 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700911 Enabled scanning of DMI to identify machine quirks. Say Y
912 here unless you have verified that your setup is not
913 affected by entries in the DMI blacklist. Required by PNP
914 BIOS code.
915
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100916config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700917 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200918 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100919 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200920 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100921 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200922 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
923 GART based hardware IOMMUs.
924
925 The GART supports full DMA access for devices with 32-bit access
926 limitations, on systems with more than 3 GB. This is usually needed
927 for USB, sound, many IDE/SATA chipsets and some other devices.
928
929 Newer systems typically have a modern AMD IOMMU, supported via
930 the CONFIG_AMD_IOMMU=y config option.
931
932 In normal configurations this driver is only active when needed:
933 there's more than 3 GB of memory and the system contains a
934 32-bit limited device.
935
936 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100937
Mike Travis1184dc22008-05-12 21:21:12 +0200938config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200939 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700940 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800941 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100942 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200943 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200944 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100945
Ingo Molnaraec64872018-02-10 12:36:29 +0100946#
947# The maximum number of CPUs supported:
948#
949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
950# and which can be configured interactively in the
951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
952#
953# The ranges are different on 32-bit and 64-bit kernels, depending on
954# hardware capabilities and scalability features of the kernel.
955#
956# ( If MAXSMP is enabled we just use the highest possible value and disable
957# interactive configuration. )
958#
959
960config NR_CPUS_RANGE_BEGIN
961 int
962 default NR_CPUS_RANGE_END if MAXSMP
963 default 1 if !SMP
964 default 2
965
966config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800967 int
968 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100969 default 64 if SMP && X86_BIGSMP
970 default 8 if SMP && !X86_BIGSMP
971 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800972
Ingo Molnaraec64872018-02-10 12:36:29 +0100973config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800974 int
975 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500976 default 8192 if SMP && CPUMASK_OFFSTACK
977 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100978 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800979
Ingo Molnaraec64872018-02-10 12:36:29 +0100980config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800981 int
982 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100983 default 32 if X86_BIGSMP
984 default 8 if SMP
985 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800986
Ingo Molnaraec64872018-02-10 12:36:29 +0100987config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800988 int
989 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100990 default 8192 if MAXSMP
991 default 64 if SMP
992 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800993
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100994config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800995 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100996 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
997 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100998 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100999 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001000 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001001 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001002 minimum value which makes sense is 2.
1003
Ingo Molnaraec64872018-02-10 12:36:29 +01001004 This is purely to save memory: each supported CPU adds about 8KB
1005 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001006
1007config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001008 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001009
1010config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001011 def_bool y
1012 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001013 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001014 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001015 Multi-core scheduler support improves the CPU scheduler's decision
1016 making when dealing with multi-core CPU chips at a cost of slightly
1017 increased overhead in some places. If unsure say N here.
1018
Tim Chende966cf2016-11-29 10:43:27 -08001019config SCHED_MC_PRIO
1020 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001021 depends on SCHED_MC && CPU_SUP_INTEL
1022 select X86_INTEL_PSTATE
1023 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001024 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001025 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001026 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1027 core ordering determined at manufacturing time, which allows
1028 certain cores to reach higher turbo frequencies (when running
1029 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001030
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001031 Enabling this kernel feature teaches the scheduler about
1032 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1033 scheduler's CPU selection logic accordingly, so that higher
1034 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001035
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001036 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001037
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001038 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001039
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001040config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001041 def_bool y
1042 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001043
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001044config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001045 bool "Local APIC support on uniprocessors" if !PCI_MSI
1046 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001047 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001048 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001049 A local APIC (Advanced Programmable Interrupt Controller) is an
1050 integrated interrupt controller in the CPU. If you have a single-CPU
1051 system which has a processor with a local APIC, you can say Y here to
1052 enable and use it. If you say Y here even though your machine doesn't
1053 have a local APIC, then the kernel will still run with no slowdown at
1054 all. The local APIC supports CPU-generated self-interrupts (timer,
1055 performance counters), and the NMI watchdog which detects hard
1056 lockups.
1057
1058config X86_UP_IOAPIC
1059 bool "IO-APIC support on uniprocessors"
1060 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001061 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001062 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1063 SMP-capable replacement for PC-style interrupt controllers. Most
1064 SMP systems and many recent uniprocessor systems have one.
1065
1066 If you have a single-CPU system with an IO-APIC, you can say Y here
1067 to use it. If you say Y here even though your machine doesn't have
1068 an IO-APIC, then the kernel will still run with no slowdown at all.
1069
1070config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001071 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001072 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001073 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001074 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001075
1076config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001077 def_bool y
1078 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001079
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001080config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1081 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001082 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001083 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001084 This option enables a workaround that fixes a source of
1085 spurious interrupts. This is recommended when threaded
1086 interrupt handling is used on systems where the generation of
1087 superfluous "boot interrupts" cannot be disabled.
1088
1089 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1090 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1091 kernel does during interrupt handling). On chipsets where this
1092 boot IRQ generation cannot be disabled, this workaround keeps
1093 the original IRQ line masked so that only the equivalent "boot
1094 IRQ" is delivered to the CPUs. The workaround also tells the
1095 kernel to set up the IRQ handler on the boot IRQ line. In this
1096 way only one interrupt is delivered to the kernel. Otherwise
1097 the spurious second interrupt may cause the kernel to bring
1098 down (vital) interrupt lines.
1099
1100 Only affects "broken" chipsets. Interrupt sharing may be
1101 increased on these systems.
1102
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001103config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001104 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001105 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001106 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001107 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001108 Machine Check support allows the processor to notify the
1109 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001110 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001111 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001112
Tony Luck5de97c92017-03-27 11:33:03 +02001113config X86_MCELOG_LEGACY
1114 bool "Support for deprecated /dev/mcelog character device"
1115 depends on X86_MCE
1116 ---help---
1117 Enable support for /dev/mcelog which is needed by the old mcelog
1118 userspace logging daemon. Consider switching to the new generation
1119 rasdaemon solution.
1120
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001121config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001122 def_bool y
1123 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001124 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001125 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001126 Additional support for intel specific MCE features such as
1127 the thermal monitor.
1128
1129config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001130 def_bool y
1131 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001132 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001133 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001134 Additional support for AMD specific MCE features such as
1135 the DRAM Error Threshold.
1136
Andi Kleen4efc0672009-04-28 19:07:31 +02001137config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001138 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001139 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001140 ---help---
1141 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001142 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001143 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001144
Andi Kleenb2762682009-02-12 13:49:31 +01001145config X86_MCE_THRESHOLD
1146 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001147 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001148
Andi Kleenea149b32009-04-29 19:31:00 +02001149config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001150 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001151 tristate "Machine check injector support"
1152 ---help---
1153 Provide support for injecting machine checks for testing purposes.
1154 If you don't know what a machine check is and you don't do kernel
1155 QA it is safe to say n.
1156
Andi Kleen4efc0672009-04-28 19:07:31 +02001157config X86_THERMAL_VECTOR
1158 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001159 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001160
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001161source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001162
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001163config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001164 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001165 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001166 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001167 This option allows user programs to put the CPU into V8086
1168 mode, which is an 80286-era approximation of 16-bit real mode.
1169
1170 Some very old versions of X and/or vbetool require this option
1171 for user mode setting. Similarly, DOSEMU will use it if
1172 available to accelerate real mode DOS programs. However, any
1173 recent version of DOSEMU, X, or vbetool should be fully
1174 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001175 fall back to software emulation. Nevertheless, if you are using
1176 a 16-bit DOS program where 16-bit performance matters, vm86
1177 mode might be faster than emulation and you might want to
1178 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001179
Ingo Molnar1e642812015-09-05 08:58:10 +02001180 Note that any app that works on a 64-bit kernel is unlikely to
1181 need this option, as 64-bit kernels don't, and can't, support
1182 V8086 mode. This option is also unrelated to 16-bit protected
1183 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001184
Ingo Molnar1e642812015-09-05 08:58:10 +02001185 Enabling this option increases the complexity of the kernel
1186 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001187
Ingo Molnar1e642812015-09-05 08:58:10 +02001188 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001189
1190config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001191 bool
1192 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001193
1194config X86_16BIT
1195 bool "Enable support for 16-bit segments" if EXPERT
1196 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001197 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001198 ---help---
1199 This option is required by programs like Wine to run 16-bit
1200 protected mode legacy code on x86 processors. Disabling
1201 this option saves about 300 bytes on i386, or around 6K text
1202 plus 16K runtime memory on x86-64,
1203
1204config X86_ESPFIX32
1205 def_bool y
1206 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001207
H. Peter Anvin197725d2014-05-04 10:00:49 -07001208config X86_ESPFIX64
1209 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001210 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001211
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001212config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001213 bool "Enable vsyscall emulation" if EXPERT
1214 default y
1215 depends on X86_64
1216 ---help---
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001217 This enables emulation of the legacy vsyscall page. Disabling
1218 it is roughly equivalent to booting with vsyscall=none, except
1219 that it will also disable the helpful warning if a program
1220 tries to use a vsyscall. With this option set to N, offending
1221 programs will just segfault, citing addresses of the form
1222 0xffffffffff600?00.
1223
1224 This option is required by many programs built before 2013, and
1225 care should be used even with newer programs if set to N.
1226
1227 Disabling this option saves about 7K of kernel size and
1228 possibly 4K of additional runtime pagetable memory.
1229
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001230config X86_IOPL_IOPERM
1231 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001232 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001233 ---help---
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001234 This enables the ioperm() and iopl() syscalls which are necessary
1235 for legacy applications.
1236
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001237 Legacy IOPL support is an overbroad mechanism which allows user
1238 space aside of accessing all 65536 I/O ports also to disable
1239 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1240 capabilities and permission from potentially active security
1241 modules.
1242
1243 The emulation restricts the functionality of the syscall to
1244 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001245 ability to disable interrupts from user space which would be
1246 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001247
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001248config TOSHIBA
1249 tristate "Toshiba Laptop support"
1250 depends on X86_32
1251 ---help---
1252 This adds a driver to safely access the System Management Mode of
1253 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1254 not work on models with a Phoenix BIOS. The System Management Mode
1255 is used to set the BIOS and power saving options on Toshiba portables.
1256
1257 For information on utilities to make use of this driver see the
1258 Toshiba Linux utilities web site at:
1259 <http://www.buzzard.org.uk/toshiba/>.
1260
1261 Say Y if you intend to run this kernel on a Toshiba portable.
1262 Say N otherwise.
1263
1264config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001265 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001266 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001267 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001268 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001269 This option enables legacy /proc/i8k userspace interface in hwmon
1270 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1271 temperature and allows controlling fan speeds of Dell laptops via
1272 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1273 it reports also power and hotkey status. For fan speed control is
1274 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001275
Pali Rohár039ae582015-05-14 13:16:37 +02001276 Say Y if you intend to run this kernel on old Dell laptops or want to
1277 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001278 Say N otherwise.
1279
1280config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001281 bool "Enable X86 board specific fixups for reboot"
1282 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001283 ---help---
1284 This enables chipset and/or board specific fixups to be done
1285 in order to get reboot to work correctly. This is only needed on
1286 some combinations of hardware and BIOS. The symptom, for which
1287 this config is intended, is when reboot ends with a stalled/hung
1288 system.
1289
1290 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001291 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001292
1293 Say Y if you want to enable the fixup. Currently, it's safe to
1294 enable this option even if you don't need it.
1295 Say N otherwise.
1296
1297config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001298 bool "CPU microcode loading support"
1299 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001300 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001301 select FW_LOADER
1302 ---help---
1303 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001304 Intel and AMD processors. The Intel support is for the IA32 family,
1305 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1306 AMD support is for families 0x10 and later. You will obviously need
1307 the actual microcode binary data itself which is not shipped with
1308 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001309
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001310 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001311 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001312 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1313 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001314
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001315 In addition, you can build the microcode into the kernel. For that you
1316 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1317 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001318
Peter Oruba8d86f392008-07-28 18:44:21 +02001319config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001320 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001321 depends on MICROCODE
1322 default MICROCODE
1323 select FW_LOADER
1324 ---help---
1325 This options enables microcode patch loading support for Intel
1326 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001327
Alanb8989db2014-01-20 18:01:56 +00001328 For the current Intel microcode data package go to
1329 <https://downloadcenter.intel.com> and search for
1330 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001331
Peter Oruba80cc9f12008-07-28 18:44:22 +02001332config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001333 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001334 depends on MICROCODE
1335 select FW_LOADER
1336 ---help---
1337 If you select this option, microcode patch loading support for AMD
1338 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001339
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001340config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001341 bool "Ancient loading interface (DEPRECATED)"
1342 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001343 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001344 ---help---
1345 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1346 which was used by userspace tools like iucode_tool and microcode.ctl.
1347 It is inadequate because it runs too late to be able to properly
1348 load microcode on a machine and it needs special tools. Instead, you
1349 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001350 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001351
1352config X86_MSR
1353 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001354 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001355 This device gives privileged processes access to the x86
1356 Model-Specific Registers (MSRs). It is a character device with
1357 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1358 MSR accesses are directed to a specific CPU on multi-processor
1359 systems.
1360
1361config X86_CPUID
1362 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001363 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001364 This device gives processes access to the x86 CPUID instruction to
1365 be executed on a specific processor. It is a character device
1366 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1367 /dev/cpu/31/cpuid.
1368
1369choice
1370 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001371 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001372 depends on X86_32
1373
1374config NOHIGHMEM
1375 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001376 ---help---
1377 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1378 However, the address space of 32-bit x86 processors is only 4
1379 Gigabytes large. That means that, if you have a large amount of
1380 physical memory, not all of it can be "permanently mapped" by the
1381 kernel. The physical memory that's not permanently mapped is called
1382 "high memory".
1383
1384 If you are compiling a kernel which will never run on a machine with
1385 more than 1 Gigabyte total physical RAM, answer "off" here (default
1386 choice and suitable for most users). This will result in a "3GB/1GB"
1387 split: 3GB are mapped so that each process sees a 3GB virtual memory
1388 space and the remaining part of the 4GB virtual memory space is used
1389 by the kernel to permanently map as much physical memory as
1390 possible.
1391
1392 If the machine has between 1 and 4 Gigabytes physical RAM, then
1393 answer "4GB" here.
1394
1395 If more than 4 Gigabytes is used then answer "64GB" here. This
1396 selection turns Intel PAE (Physical Address Extension) mode on.
1397 PAE implements 3-level paging on IA32 processors. PAE is fully
1398 supported by Linux, PAE mode is implemented on all recent Intel
1399 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1400 then the kernel will not boot on CPUs that don't support PAE!
1401
1402 The actual amount of total physical memory will either be
1403 auto detected or can be forced by using a kernel command line option
1404 such as "mem=256M". (Try "man bootparam" or see the documentation of
1405 your boot loader (lilo or loadlin) about how to pass options to the
1406 kernel at boot time.)
1407
1408 If unsure, say "off".
1409
1410config HIGHMEM4G
1411 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001412 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001413 Select this if you have a 32-bit processor and between 1 and 4
1414 gigabytes of physical RAM.
1415
1416config HIGHMEM64G
1417 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001418 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001419 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001420 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001421 Select this if you have a 32-bit processor and more than 4
1422 gigabytes of physical RAM.
1423
1424endchoice
1425
1426choice
David Rientjes6a108a12011-01-20 14:44:16 -08001427 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001428 default VMSPLIT_3G
1429 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001430 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001431 Select the desired split between kernel and user memory.
1432
1433 If the address range available to the kernel is less than the
1434 physical memory installed, the remaining memory will be available
1435 as "high memory". Accessing high memory is a little more costly
1436 than low memory, as it needs to be mapped into the kernel first.
1437 Note that increasing the kernel address space limits the range
1438 available to user programs, making the address space there
1439 tighter. Selecting anything other than the default 3G/1G split
1440 will also likely make your kernel incompatible with binary-only
1441 kernel modules.
1442
1443 If you are not absolutely sure what you are doing, leave this
1444 option alone!
1445
1446 config VMSPLIT_3G
1447 bool "3G/1G user/kernel split"
1448 config VMSPLIT_3G_OPT
1449 depends on !X86_PAE
1450 bool "3G/1G user/kernel split (for full 1G low memory)"
1451 config VMSPLIT_2G
1452 bool "2G/2G user/kernel split"
1453 config VMSPLIT_2G_OPT
1454 depends on !X86_PAE
1455 bool "2G/2G user/kernel split (for full 2G low memory)"
1456 config VMSPLIT_1G
1457 bool "1G/3G user/kernel split"
1458endchoice
1459
1460config PAGE_OFFSET
1461 hex
1462 default 0xB0000000 if VMSPLIT_3G_OPT
1463 default 0x80000000 if VMSPLIT_2G
1464 default 0x78000000 if VMSPLIT_2G_OPT
1465 default 0x40000000 if VMSPLIT_1G
1466 default 0xC0000000
1467 depends on X86_32
1468
1469config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001470 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001471 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001472
1473config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001474 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001475 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001476 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001477 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001478 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001479 PAE is required for NX support, and furthermore enables
1480 larger swapspace support for non-overcommit purposes. It
1481 has the cost of more pagetable lookup overhead, and also
1482 consumes more pagetable space per process.
1483
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001484config X86_5LEVEL
1485 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001486 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001487 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001488 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001489 depends on X86_64
1490 ---help---
1491 5-level paging enables access to larger address space:
1492 upto 128 PiB of virtual address space and 4 PiB of
1493 physical address space.
1494
1495 It will be supported by future Intel CPUs.
1496
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001497 A kernel with the option enabled can be booted on machines that
1498 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001499
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001500 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001501 information.
1502
1503 Say N if unsure.
1504
Ingo Molnar10971ab2015-03-05 08:18:23 +01001505config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001506 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001507 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001508 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001509 Certain kernel features effectively disable kernel
1510 linear 1 GB mappings (even if the CPU otherwise
1511 supports them), so don't confuse the user by printing
1512 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001513
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001514config X86_CPA_STATISTICS
1515 bool "Enable statistic for Change Page Attribute"
1516 depends on DEBUG_FS
1517 ---help---
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001518 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001519 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001520 page mappings when mapping protections are changed.
1521
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001522config AMD_MEM_ENCRYPT
1523 bool "AMD Secure Memory Encryption (SME) support"
1524 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001525 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001526 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001527 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001528 ---help---
1529 Say yes to enable support for the encryption of system memory.
1530 This requires an AMD processor that supports Secure Memory
1531 Encryption (SME).
1532
1533config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1534 bool "Activate AMD Secure Memory Encryption (SME) by default"
1535 default y
1536 depends on AMD_MEM_ENCRYPT
1537 ---help---
1538 Say yes to have system memory encrypted by default if running on
1539 an AMD processor that supports Secure Memory Encryption (SME).
1540
1541 If set to Y, then the encryption of system memory can be
1542 deactivated with the mem_encrypt=off command line option.
1543
1544 If set to N, then the encryption of system memory can be
1545 activated with the mem_encrypt=on command line option.
1546
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001547# Common NUMA Features
1548config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001549 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001550 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001551 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1552 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001553 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -08001554 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001555
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001556 The kernel will try to allocate memory used by a CPU on the
1557 local memory controller of the CPU and add some more
1558 NUMA awareness to the kernel.
1559
Ingo Molnarc280ea52008-11-08 13:29:45 +01001560 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001561 (or later), AMD Opteron, or EM64T NUMA.
1562
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001563 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001564 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001565
1566 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001567
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001568config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001569 def_bool y
1570 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001571 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001572 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001573 Enable AMD NUMA node topology detection. You should say Y here if
1574 you have a multi processor AMD system. This uses an old method to
1575 read the NUMA configuration directly from the builtin Northbridge
1576 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1577 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001578
1579config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001580 def_bool y
1581 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001582 depends on X86_64 && NUMA && ACPI && PCI
1583 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001584 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001585 Enable ACPI SRAT based node topology detection.
1586
1587config NUMA_EMU
1588 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001589 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001590 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001591 Enable NUMA emulation. A flat machine will be split
1592 into virtual nodes when booted with "numa=fake=N", where N is the
1593 number of nodes. This is only useful for debugging.
1594
1595config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001596 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001597 range 1 10
1598 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001599 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001600 default "3"
1601 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001602 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001603 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001604 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001605
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001606config ARCH_FLATMEM_ENABLE
1607 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001608 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001609
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001610config ARCH_SPARSEMEM_ENABLE
1611 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001612 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001613 select SPARSEMEM_STATIC if X86_32
1614 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1615
Tejun Heo3b166512011-04-01 11:15:12 +02001616config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001617 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001618
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001619config ARCH_SELECT_MEMORY_MODEL
1620 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001621 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001622
1623config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001624 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001625 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001626 help
1627 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001628 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001629 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001630
Tejun Heo3b166512011-04-01 11:15:12 +02001631config ARCH_PROC_KCORE_TEXT
1632 def_bool y
1633 depends on X86_64 && PROC_KCORE
1634
Avi Kivitya29815a2010-01-10 16:28:09 +02001635config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001636 hex
1637 default 0 if X86_32
1638 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001639
Dan Williams7a678322015-08-19 00:34:34 -04001640config X86_PMEM_LEGACY_DEVICE
1641 bool
1642
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001643config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001644 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001645 depends on PHYS_ADDR_T_64BIT
1646 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001647 select X86_PMEM_LEGACY_DEVICE
Dan Williams7b27a862020-02-16 12:01:16 -08001648 select NUMA_KEEP_MEMINFO if NUMA
Dan Williams9f53f9f2015-06-09 15:33:45 -04001649 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001650 help
1651 Treat memory marked using the non-standard e820 type of 12 as used
1652 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1653 The kernel will offer these regions to the 'pmem' driver so
1654 they can be used for persistent storage.
1655
1656 Say Y if unsure.
1657
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001658config HIGHPTE
1659 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001660 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001661 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001662 The VM uses one page table entry for each page of physical memory.
1663 For systems with a lot of RAM, this can be wasteful of precious
1664 low memory. Setting this option will put user-space page table
1665 entries in high memory.
1666
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001667config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001668 bool "Check for low memory corruption"
1669 ---help---
1670 Periodically check for memory corruption in low memory, which
1671 is suspected to be caused by BIOS. Even when enabled in the
1672 configuration, it is disabled at runtime. Enable it by
1673 setting "memory_corruption_check=1" on the kernel command
1674 line. By default it scans the low 64k of memory every 60
1675 seconds; see the memory_corruption_check_size and
1676 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001677 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001678
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001679 When enabled with the default parameters, this option has
1680 almost no overhead, as it reserves a relatively small amount
1681 of memory and scans it infrequently. It both detects corruption
1682 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001683
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001684 It is, however, intended as a diagnostic tool; if repeatable
1685 BIOS-originated corruption always affects the same memory,
1686 you can use memmap= to prevent the kernel from using that
1687 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001688
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001689config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001690 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001691 depends on X86_CHECK_BIOS_CORRUPTION
1692 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001693 ---help---
1694 Set whether the default state of memory_corruption_check is
1695 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001696
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001697config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001698 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1699 default 64
1700 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001701 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001702 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001703
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001704 The first page contains BIOS data structures that the kernel
1705 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001706
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001707 By default we reserve the first 64K of physical RAM, as a
1708 number of BIOSes are known to corrupt that memory range
1709 during events such as suspend/resume or monitor cable
1710 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001711
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001712 You can set this to 4 if you are absolutely sure that you
1713 trust the BIOS to get all its memory reservations and usages
1714 right. If you know your BIOS have problems beyond the
1715 default 64K area, you can set this to 640 to avoid using the
1716 entire low memory range.
1717
1718 If you have doubts about the BIOS (e.g. suspend/resume does
1719 not work or there's kernel crashes after certain hardware
1720 hotplug events) then you might want to enable
1721 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1722 typical corruption patterns.
1723
1724 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001725
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001726config MATH_EMULATION
1727 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001728 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001729 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001730 ---help---
1731 Linux can emulate a math coprocessor (used for floating point
1732 operations) if you don't have one. 486DX and Pentium processors have
1733 a math coprocessor built in, 486SX and 386 do not, unless you added
1734 a 487DX or 387, respectively. (The messages during boot time can
1735 give you some hints here ["man dmesg"].) Everyone needs either a
1736 coprocessor or this emulation.
1737
1738 If you don't have a math coprocessor, you need to say Y here; if you
1739 say Y here even though you have a coprocessor, the coprocessor will
1740 be used nevertheless. (This behavior can be changed with the kernel
1741 command line option "no387", which comes handy if your coprocessor
1742 is broken. Try "man bootparam" or see the documentation of your boot
1743 loader (lilo or loadlin) about how to pass options to the kernel at
1744 boot time.) This means that it is a good idea to say Y here if you
1745 intend to use this kernel on different machines.
1746
1747 More information about the internals of the Linux math coprocessor
1748 emulation can be found in <file:arch/x86/math-emu/README>.
1749
1750 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1751 kernel, it won't hurt.
1752
1753config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001754 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001755 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001756 ---help---
1757 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1758 the Memory Type Range Registers (MTRRs) may be used to control
1759 processor access to memory ranges. This is most useful if you have
1760 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1761 allows bus write transfers to be combined into a larger transfer
1762 before bursting over the PCI/AGP bus. This can increase performance
1763 of image write operations 2.5 times or more. Saying Y here creates a
1764 /proc/mtrr file which may be used to manipulate your processor's
1765 MTRRs. Typically the X server should use this.
1766
1767 This code has a reasonably generic interface so that similar
1768 control registers on other processors can be easily supported
1769 as well:
1770
1771 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1772 Registers (ARRs) which provide a similar functionality to MTRRs. For
1773 these, the ARRs are used to emulate the MTRRs.
1774 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1775 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1776 write-combining. All of these processors are supported by this code
1777 and it makes sense to say Y here if you have one of them.
1778
1779 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1780 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1781 can lead to all sorts of problems, so it's good to say Y here.
1782
1783 You can safely say Y even if your machine doesn't have MTRRs, you'll
1784 just add about 9 KB to your kernel.
1785
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001786 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001787
Yinghai Lu95ffa242008-04-29 03:52:33 -07001788config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001789 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001790 prompt "MTRR cleanup support"
1791 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001792 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001793 Convert MTRR layout from continuous to discrete, so X drivers can
1794 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001795
Thomas Gleixneraba37282008-07-15 14:48:48 +02001796 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001797 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001798 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001799
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001800 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001801
1802config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001803 int "MTRR cleanup enable value (0-1)"
1804 range 0 1
1805 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001806 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001807 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001808 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001809
Yinghai Lu12031a62008-05-02 02:40:22 -07001810config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1811 int "MTRR cleanup spare reg num (0-7)"
1812 range 0 7
1813 default "1"
1814 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001815 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001816 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001817 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001818
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001819config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001820 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001821 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001822 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001823 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001824 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001825
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001826 PATs are the modern equivalents of MTRRs and are much more
1827 flexible than MTRRs.
1828
1829 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001830 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001831
1832 If unsure, say Y.
1833
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001834config ARCH_USES_PG_UNCACHED
1835 def_bool y
1836 depends on X86_PAT
1837
H. Peter Anvin628c6242011-07-31 13:59:29 -07001838config ARCH_RANDOM
1839 def_bool y
1840 prompt "x86 architectural random number generator" if EXPERT
1841 ---help---
1842 Enable the x86 architectural RDRAND instruction
1843 (Intel Bull Mountain technology) to generate random numbers.
1844 If supported, this is a high bandwidth, cryptographically
1845 secure hardware random number generator.
1846
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001847config X86_SMAP
1848 def_bool y
1849 prompt "Supervisor Mode Access Prevention" if EXPERT
1850 ---help---
1851 Supervisor Mode Access Prevention (SMAP) is a security
1852 feature in newer Intel processors. There is a small
1853 performance cost if this enabled and turned on; there is
1854 also a small increase in the kernel size if this is enabled.
1855
1856 If unsure, say Y.
1857
Babu Mogerb9718802019-11-05 21:25:32 +00001858config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001859 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001860 prompt "User Mode Instruction Prevention" if EXPERT
Ricardo Neriaa35f892017-11-05 18:27:54 -08001861 ---help---
Babu Mogerb9718802019-11-05 21:25:32 +00001862 User Mode Instruction Prevention (UMIP) is a security feature in
1863 some x86 processors. If enabled, a general protection fault is
1864 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1865 executed in user mode. These instructions unnecessarily expose
1866 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001867
1868 The vast majority of applications do not use these instructions.
1869 For the very few that do, software emulation is provided in
1870 specific cases in protected and virtual-8086 modes. Emulated
1871 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001872
Dave Hansen35e97792016-02-12 13:02:00 -08001873config X86_INTEL_MEMORY_PROTECTION_KEYS
Babu Moger38f3e772020-05-28 11:08:23 -05001874 prompt "Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001875 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001876 # Note: only available in 64-bit mode
Babu Moger38f3e772020-05-28 11:08:23 -05001877 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Ingo Molnar52c8e602016-11-15 10:15:03 +01001878 select ARCH_USES_HIGH_VMA_FLAGS
1879 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001880 ---help---
1881 Memory Protection Keys provides a mechanism for enforcing
1882 page-based protections, but without requiring modification of the
1883 page tables when an application changes protection domains.
1884
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001885 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001886
1887 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001888
Michal Hockodb616172019-10-23 12:35:50 +02001889choice
1890 prompt "TSX enable mode"
1891 depends on CPU_SUP_INTEL
1892 default X86_INTEL_TSX_MODE_OFF
1893 help
1894 Intel's TSX (Transactional Synchronization Extensions) feature
1895 allows to optimize locking protocols through lock elision which
1896 can lead to a noticeable performance boost.
1897
1898 On the other hand it has been shown that TSX can be exploited
1899 to form side channel attacks (e.g. TAA) and chances are there
1900 will be more of those attacks discovered in the future.
1901
1902 Therefore TSX is not enabled by default (aka tsx=off). An admin
1903 might override this decision by tsx=on the command line parameter.
1904 Even with TSX enabled, the kernel will attempt to enable the best
1905 possible TAA mitigation setting depending on the microcode available
1906 for the particular machine.
1907
1908 This option allows to set the default tsx mode between tsx=on, =off
1909 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1910 details.
1911
1912 Say off if not sure, auto if TSX is in use but it should be used on safe
1913 platforms or on if TSX is in use and the security aspect of tsx is not
1914 relevant.
1915
1916config X86_INTEL_TSX_MODE_OFF
1917 bool "off"
1918 help
1919 TSX is disabled if possible - equals to tsx=off command line parameter.
1920
1921config X86_INTEL_TSX_MODE_ON
1922 bool "on"
1923 help
1924 TSX is always enabled on TSX capable HW - equals the tsx=on command
1925 line parameter.
1926
1927config X86_INTEL_TSX_MODE_AUTO
1928 bool "auto"
1929 help
1930 TSX is enabled on TSX capable HW that is believed to be safe against
1931 side channel attacks- equals the tsx=auto command line parameter.
1932endchoice
1933
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001934config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001935 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001936 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001937 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001938 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001939 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001940 This enables the kernel to use EFI runtime services that are
1941 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001942
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001943 This option is only useful on systems that have EFI firmware.
1944 In addition, you should use the latest ELILO loader available
1945 at <http://elilo.sourceforge.net> in order to take advantage
1946 of EFI runtime services. However, even with this option, the
1947 resultant kernel should continue to boot on existing non-EFI
1948 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001949
Matt Fleming291f3632011-12-12 21:27:52 +00001950config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001951 bool "EFI stub support"
1952 depends on EFI && !X86_USE_3DNOW
1953 depends on $(cc-option,-mabi=ms) || X86_32
1954 select RELOCATABLE
1955 ---help---
1956 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001957 by EFI firmware without the use of a bootloader.
1958
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001959 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001960
Matt Fleming7d453ee2014-01-10 18:52:06 +00001961config EFI_MIXED
1962 bool "EFI mixed-mode support"
1963 depends on EFI_STUB && X86_64
1964 ---help---
1965 Enabling this feature allows a 64-bit kernel to be booted
1966 on a 32-bit firmware, provided that your CPU supports 64-bit
1967 mode.
1968
1969 Note that it is not possible to boot a mixed-mode enabled
1970 kernel via the EFI boot stub - a bootloader that supports
1971 the EFI handover protocol must be used.
1972
1973 If unsure, say N.
1974
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001975config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001976 def_bool y
1977 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001978 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001979 This kernel feature is useful for number crunching applications
1980 that may need to compute untrusted bytecode during their
1981 execution. By using pipes or other transports made available to
1982 the process as file descriptors supporting the read/write
1983 syscalls, it's possible to isolate those applications in
1984 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001985 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001986 and the task is only allowed to execute a few safe syscalls
1987 defined by each seccomp mode.
1988
1989 If unsure, say Y. Only embedded should say N here.
1990
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09001991source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001992
1993config KEXEC
1994 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001995 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001996 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001997 kexec is a system call that implements the ability to shutdown your
1998 current kernel, and to start another kernel. It is like a reboot
1999 but it is independent of the system firmware. And like a reboot
2000 you can start any kernel with it, not just Linux.
2001
2002 The name comes from the similarity to the exec system call.
2003
2004 It is an ongoing process to be certain the hardware in a machine
2005 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002006 initially work for you. As of this writing the exact hardware
2007 interface is strongly in flux, so no good recommendation can be
2008 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002009
Vivek Goyal74ca3172014-08-29 15:18:46 -07002010config KEXEC_FILE
2011 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002012 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002013 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002014 depends on X86_64
2015 depends on CRYPTO=y
2016 depends on CRYPTO_SHA256=y
2017 ---help---
2018 This is new version of kexec system call. This system call is
2019 file based and takes file descriptors as system call argument
2020 for kernel and initramfs as opposed to list of segments as
2021 accepted by previous system call.
2022
AKASHI Takahirob799a092018-04-13 15:35:45 -07002023config ARCH_HAS_KEXEC_PURGATORY
2024 def_bool KEXEC_FILE
2025
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002026config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002027 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002028 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002029 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002030
2031 This option makes the kexec_file_load() syscall check for a valid
2032 signature of the kernel image. The image can still be loaded without
2033 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2034 there's a signature that we can check, then it must be valid.
2035
2036 In addition to this option, you need to enable signature
2037 verification for the corresponding kernel image type being
2038 loaded in order for this to work.
2039
2040config KEXEC_SIG_FORCE
2041 bool "Require a valid signature in kexec_file_load() syscall"
2042 depends on KEXEC_SIG
2043 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002044 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002045 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002046
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002047config KEXEC_BZIMAGE_VERIFY_SIG
2048 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002049 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002050 depends on SIGNED_PE_FILE_VERIFICATION
2051 select SYSTEM_TRUSTED_KEYRING
2052 ---help---
2053 Enable bzImage signature verification support.
2054
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002055config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002056 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002057 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002058 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002059 Generate crash dump after being started by kexec.
2060 This should be normally only set in special crash dump kernels
2061 which are loaded in the main kernel with kexec-tools into
2062 a specially reserved region and then later executed after
2063 a crash by kdump/kexec. The crash dump kernel must be compiled
2064 to a memory address not used by the main kernel or BIOS using
2065 PHYSICAL_START, or it must be built as a relocatable image
2066 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002067 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002068
Huang Ying3ab83522008-07-25 19:45:07 -07002069config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002070 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002071 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002072 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002073 Jump between original kernel and kexeced kernel and invoke
2074 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002075
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002076config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002077 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002078 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002079 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002080 This gives the physical address where the kernel is loaded.
2081
2082 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2083 bzImage will decompress itself to above physical address and
2084 run from there. Otherwise, bzImage will run from the address where
2085 it has been loaded by the boot loader and will ignore above physical
2086 address.
2087
2088 In normal kdump cases one does not have to set/change this option
2089 as now bzImage can be compiled as a completely relocatable image
2090 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2091 address. This option is mainly useful for the folks who don't want
2092 to use a bzImage for capturing the crash dump and want to use a
2093 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2094 to be specifically compiled to run from a specific memory area
2095 (normally a reserved region) and this option comes handy.
2096
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002097 So if you are using bzImage for capturing the crash dump,
2098 leave the value here unchanged to 0x1000000 and set
2099 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2100 for capturing the crash dump change this value to start of
2101 the reserved region. In other words, it can be set based on
2102 the "X" value as specified in the "crashkernel=YM@XM"
2103 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002104 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002105 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002106
2107 Usage of bzImage for capturing the crash dump is recommended as
2108 one does not have to build two kernels. Same kernel can be used
2109 as production kernel and capture kernel. Above option should have
2110 gone away after relocatable bzImage support is introduced. But it
2111 is present because there are users out there who continue to use
2112 vmlinux for dump capture. This option should go away down the
2113 line.
2114
2115 Don't change this unless you know what you are doing.
2116
2117config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002118 bool "Build a relocatable kernel"
2119 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002120 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002121 This builds a kernel image that retains relocation information
2122 so it can be loaded someplace besides the default 1MB.
2123 The relocations tend to make the kernel binary about 10% larger,
2124 but are discarded at runtime.
2125
2126 One use is for the kexec on panic case where the recovery kernel
2127 must live at a different physical address than the primary
2128 kernel.
2129
2130 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2131 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002132 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002133
Kees Cook8ab38202013-10-10 17:18:14 -07002134config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002135 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002136 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002137 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002138 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002139 In support of Kernel Address Space Layout Randomization (KASLR),
2140 this randomizes the physical address at which the kernel image
2141 is decompressed and the virtual address where the kernel
2142 image is mapped, as a security feature that deters exploit
2143 attempts relying on knowledge of the location of kernel
2144 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002145
Kees Cooked9f0072016-05-25 15:45:33 -07002146 On 64-bit, the kernel physical and virtual addresses are
2147 randomized separately. The physical address will be anywhere
2148 between 16MB and the top of physical memory (up to 64TB). The
2149 virtual address will be randomized from 16MB up to 1GB (9 bits
2150 of entropy). Note that this also reduces the memory space
2151 available to kernel modules from 1.5GB to 1GB.
2152
2153 On 32-bit, the kernel physical and virtual addresses are
2154 randomized together. They will be randomized from 16MB up to
2155 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002156
Baoquan Hee8581e32016-04-20 13:55:43 -07002157 Entropy is generated using the RDRAND instruction if it is
2158 supported. If RDTSC is supported, its value is mixed into
2159 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002160 supported, then entropy is read from the i8254 timer. The
2161 usable entropy is limited by the kernel being built using
2162 2GB addressing, and that PHYSICAL_ALIGN must be at a
2163 minimum of 2MB. As a result, only 10 bits of entropy are
2164 theoretically possible, but the implementations are further
2165 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002166
Ingo Molnar6807c842017-04-18 11:08:12 +02002167 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002168
2169# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002170config X86_NEED_RELOCS
2171 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002172 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002173
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002174config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002175 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002176 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002177 range 0x2000 0x1000000 if X86_32
2178 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002179 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002180 This value puts the alignment restrictions on physical address
2181 where kernel is loaded and run from. Kernel is compiled for an
2182 address which meets above alignment restriction.
2183
2184 If bootloader loads the kernel at a non-aligned address and
2185 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2186 address aligned to above value and run from there.
2187
2188 If bootloader loads the kernel at a non-aligned address and
2189 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2190 load address and decompress itself to the address it has been
2191 compiled for and run from there. The address for which kernel is
2192 compiled already meets above alignment restrictions. Hence the
2193 end result is that kernel runs from a physical address meeting
2194 above alignment restrictions.
2195
Kees Cooka0215062013-07-08 09:15:17 -07002196 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2197 this value must be a multiple of 0x200000.
2198
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002199 Don't change this unless you know what you are doing.
2200
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002201config DYNAMIC_MEMORY_LAYOUT
2202 bool
2203 ---help---
2204 This option makes base addresses of vmalloc and vmemmap as well as
2205 __PAGE_OFFSET movable during boot.
2206
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002207config RANDOMIZE_MEMORY
2208 bool "Randomize the kernel memory sections"
2209 depends on X86_64
2210 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002211 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002212 default RANDOMIZE_BASE
2213 ---help---
2214 Randomizes the base virtual address of kernel memory sections
2215 (physical memory mapping, vmalloc & vmemmap). This security feature
2216 makes exploits relying on predictable memory locations less reliable.
2217
2218 The order of allocations remains unchanged. Entropy is generated in
2219 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2220 configuration have in average 30,000 different possible virtual
2221 addresses for each memory section.
2222
Ingo Molnar6807c842017-04-18 11:08:12 +02002223 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002224
Thomas Garnier90397a42016-06-21 17:47:06 -07002225config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2226 hex "Physical memory mapping padding" if EXPERT
2227 depends on RANDOMIZE_MEMORY
2228 default "0xa" if MEMORY_HOTPLUG
2229 default "0x0"
2230 range 0x1 0x40 if MEMORY_HOTPLUG
2231 range 0x0 0x40
2232 ---help---
2233 Define the padding in terabytes added to the existing physical
2234 memory size during kernel memory randomization. It is useful
2235 for memory hotplug support but reduces the entropy available for
2236 address randomization.
2237
2238 If unsure, leave at the default value.
2239
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002240config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002241 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002242 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002243
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002244config BOOTPARAM_HOTPLUG_CPU0
2245 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002246 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002247 ---help---
2248 Set whether default state of cpu0_hotpluggable is on or off.
2249
2250 Say Y here to enable CPU0 hotplug by default. If this switch
2251 is turned on, there is no need to give cpu0_hotplug kernel
2252 parameter and the CPU0 hotplug feature is enabled by default.
2253
2254 Please note: there are two known CPU0 dependencies if you want
2255 to enable the CPU0 hotplug feature either by this switch or by
2256 cpu0_hotplug kernel parameter.
2257
2258 First, resume from hibernate or suspend always starts from CPU0.
2259 So hibernate and suspend are prevented if CPU0 is offline.
2260
2261 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2262 offline if any interrupt can not migrate out of CPU0. There may
2263 be other CPU0 dependencies.
2264
2265 Please make sure the dependencies are under your control before
2266 you enable this feature.
2267
2268 Say N if you don't want to enable CPU0 hotplug feature by default.
2269 You still can enable the CPU0 hotplug feature at boot by kernel
2270 parameter cpu0_hotplug.
2271
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002272config DEBUG_HOTPLUG_CPU0
2273 def_bool n
2274 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002275 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002276 ---help---
2277 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2278 soon as possible and boots up userspace with CPU0 offlined. User
2279 can online CPU0 back after boot time.
2280
2281 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2282 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2283 compilation or giving cpu0_hotplug kernel parameter at boot.
2284
2285 If unsure, say N.
2286
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002287config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002288 def_bool n
2289 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002290 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002291 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002292 Certain buggy versions of glibc will crash if they are
2293 presented with a 32-bit vDSO that is not mapped at the address
2294 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002295
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002296 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2297 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2298 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2299 the only released version with the bug, but OpenSUSE 9
2300 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002301
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002302 The symptom of the bug is that everything crashes on startup, saying:
2303 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2304
2305 Saying Y here changes the default value of the vdso32 boot
2306 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2307 This works around the glibc bug but hurts performance.
2308
2309 If unsure, say N: if you are compiling your own kernel, you
2310 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002311
Kees Cook3dc33bd2015-08-12 17:55:19 -07002312choice
2313 prompt "vsyscall table for legacy applications"
2314 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002315 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002316 help
2317 Legacy user code that does not know how to find the vDSO expects
2318 to be able to issue three syscalls by calling fixed addresses in
2319 kernel space. Since this location is not randomized with ASLR,
2320 it can be used to assist security vulnerability exploitation.
2321
2322 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002323 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002324
2325 On a system with recent enough glibc (2.14 or newer) and no
2326 static binaries, you can say None without a performance penalty
2327 to improve security.
2328
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002329 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002330
Kees Cook3dc33bd2015-08-12 17:55:19 -07002331 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002332 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002333 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002334 The kernel traps and emulates calls into the fixed vsyscall
2335 address mapping. This makes the mapping non-executable, but
2336 it still contains readable known contents, which could be
2337 used in certain rare security vulnerability exploits. This
2338 configuration is recommended when using legacy userspace
2339 that still uses vsyscalls along with legacy binary
2340 instrumentation tools that require code to be readable.
2341
2342 An example of this type of legacy userspace is running
2343 Pin on an old binary that still uses vsyscalls.
2344
2345 config LEGACY_VSYSCALL_XONLY
2346 bool "Emulate execution only"
2347 help
2348 The kernel traps and emulates calls into the fixed vsyscall
2349 address mapping and does not allow reads. This
2350 configuration is recommended when userspace might use the
2351 legacy vsyscall area but support for legacy binary
2352 instrumentation of legacy code is not needed. It mitigates
2353 certain uses of the vsyscall area as an ASLR-bypassing
2354 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002355
2356 config LEGACY_VSYSCALL_NONE
2357 bool "None"
2358 help
2359 There will be no vsyscall mapping at all. This will
2360 eliminate any risk of ASLR bypass due to the vsyscall
2361 fixed address mapping. Attempts to use the vsyscalls
2362 will be reported to dmesg, so that either old or
2363 malicious userspace programs can be identified.
2364
2365endchoice
2366
Tim Bird516cbf32008-08-12 12:52:36 -07002367config CMDLINE_BOOL
2368 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002369 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002370 Allow for specifying boot arguments to the kernel at
2371 build time. On some systems (e.g. embedded ones), it is
2372 necessary or convenient to provide some or all of the
2373 kernel boot arguments with the kernel itself (that is,
2374 to not rely on the boot loader to provide them.)
2375
2376 To compile command line arguments into the kernel,
2377 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002378 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002379
2380 Systems with fully functional boot loaders (i.e. non-embedded)
2381 should leave this option set to 'N'.
2382
2383config CMDLINE
2384 string "Built-in kernel command string"
2385 depends on CMDLINE_BOOL
2386 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002387 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002388 Enter arguments here that should be compiled into the kernel
2389 image and used at boot time. If the boot loader provides a
2390 command line at boot time, it is appended to this string to
2391 form the full kernel command line, when the system boots.
2392
2393 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2394 change this behavior.
2395
2396 In most cases, the command line (whether built-in or provided
2397 by the boot loader) should specify the device for the root
2398 file system.
2399
2400config CMDLINE_OVERRIDE
2401 bool "Built-in command line overrides boot loader arguments"
Anders Roxell645e6462020-01-24 12:46:15 +01002402 depends on CMDLINE_BOOL && CMDLINE != ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002403 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002404 Set this option to 'Y' to have the kernel ignore the boot loader
2405 command line, and use ONLY the built-in command line.
2406
2407 This is used to work around broken boot loaders. This should
2408 be set to 'N' under normal conditions.
2409
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002410config MODIFY_LDT_SYSCALL
2411 bool "Enable the LDT (local descriptor table)" if EXPERT
2412 default y
2413 ---help---
2414 Linux can allow user programs to install a per-process x86
2415 Local Descriptor Table (LDT) using the modify_ldt(2) system
2416 call. This is required to run 16-bit or segmented code such as
2417 DOSEMU or some Wine programs. It is also used by some very old
2418 threading libraries.
2419
2420 Enabling this feature adds a small amount of overhead to
2421 context switches and increases the low-level kernel attack
2422 surface. Disabling it removes the modify_ldt(2) system call.
2423
2424 Saying 'N' here may make sense for embedded or server kernels.
2425
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002426source "kernel/livepatch/Kconfig"
2427
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002428endmenu
2429
Michal Hocko3072e412017-09-08 16:11:39 -07002430config ARCH_HAS_ADD_PAGES
2431 def_bool y
2432 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2433
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002434config ARCH_ENABLE_MEMORY_HOTPLUG
2435 def_bool y
2436 depends on X86_64 || (X86_32 && HIGHMEM)
2437
Gary Hade35551052008-10-31 10:52:03 -07002438config ARCH_ENABLE_MEMORY_HOTREMOVE
2439 def_bool y
2440 depends on MEMORY_HOTPLUG
2441
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002442config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002443 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002444 depends on NUMA
2445
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002446config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2447 def_bool y
2448 depends on X86_64 || X86_PAE
2449
Naoya Horiguchic177c812014-06-04 16:05:35 -07002450config ARCH_ENABLE_HUGEPAGE_MIGRATION
2451 def_bool y
2452 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2453
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002454config ARCH_ENABLE_THP_MIGRATION
2455 def_bool y
2456 depends on X86_64 && TRANSPARENT_HUGEPAGE
2457
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002458menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002459
2460config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002461 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002462 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002463
2464source "kernel/power/Kconfig"
2465
2466source "drivers/acpi/Kconfig"
2467
Feng Tangefafc8b2009-08-14 15:23:29 -04002468source "drivers/sfi/Kconfig"
2469
Andi Kleena6b68072008-01-30 13:32:49 +01002470config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002471 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002472 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002473
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002474menuconfig APM
2475 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002476 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002477 ---help---
2478 APM is a BIOS specification for saving power using several different
2479 techniques. This is mostly useful for battery powered laptops with
2480 APM compliant BIOSes. If you say Y here, the system time will be
2481 reset after a RESUME operation, the /proc/apm device will provide
2482 battery status information, and user-space programs will receive
2483 notification of APM "events" (e.g. battery status change).
2484
2485 If you select "Y" here, you can disable actual use of the APM
2486 BIOS by passing the "apm=off" option to the kernel at boot time.
2487
2488 Note that the APM support is almost completely disabled for
2489 machines with more than one CPU.
2490
2491 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002492 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002493 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002494 <http://www.tldp.org/docs.html#howto>.
2495
2496 This driver does not spin down disk drives (see the hdparm(8)
2497 manpage ("man 8 hdparm") for that), and it doesn't turn off
2498 VESA-compliant "green" monitors.
2499
2500 This driver does not support the TI 4000M TravelMate and the ACER
2501 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2502 desktop machines also don't have compliant BIOSes, and this driver
2503 may cause those machines to panic during the boot phase.
2504
2505 Generally, if you don't have a battery in your machine, there isn't
2506 much point in using this driver and you should say N. If you get
2507 random kernel OOPSes or reboots that don't seem to be related to
2508 anything, try disabling/enabling this option (or disabling/enabling
2509 APM in your BIOS).
2510
2511 Some other things you should try when experiencing seemingly random,
2512 "weird" problems:
2513
2514 1) make sure that you have enough swap space and that it is
2515 enabled.
2516 2) pass the "no-hlt" option to the kernel
2517 3) switch on floating point emulation in the kernel and pass
2518 the "no387" option to the kernel
2519 4) pass the "floppy=nodma" option to the kernel
2520 5) pass the "mem=4M" option to the kernel (thereby disabling
2521 all but the first 4 MB of RAM)
2522 6) make sure that the CPU is not over clocked.
2523 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2524 8) disable the cache from your BIOS settings
2525 9) install a fan for the video card or exchange video RAM
2526 10) install a better fan for the CPU
2527 11) exchange RAM chips
2528 12) exchange the motherboard.
2529
2530 To compile this driver as a module, choose M here: the
2531 module will be called apm.
2532
2533if APM
2534
2535config APM_IGNORE_USER_SUSPEND
2536 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002537 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002538 This option will ignore USER SUSPEND requests. On machines with a
2539 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2540 series notebooks, it is necessary to say Y because of a BIOS bug.
2541
2542config APM_DO_ENABLE
2543 bool "Enable PM at boot time"
2544 ---help---
2545 Enable APM features at boot time. From page 36 of the APM BIOS
2546 specification: "When disabled, the APM BIOS does not automatically
2547 power manage devices, enter the Standby State, enter the Suspend
2548 State, or take power saving steps in response to CPU Idle calls."
2549 This driver will make CPU Idle calls when Linux is idle (unless this
2550 feature is turned off -- see "Do CPU IDLE calls", below). This
2551 should always save battery power, but more complicated APM features
2552 will be dependent on your BIOS implementation. You may need to turn
2553 this option off if your computer hangs at boot time when using APM
2554 support, or if it beeps continuously instead of suspending. Turn
2555 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2556 T400CDT. This is off by default since most machines do fine without
2557 this feature.
2558
2559config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002560 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002561 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002562 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002563 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2564 On some machines, this can activate improved power savings, such as
2565 a slowed CPU clock rate, when the machine is idle. These idle calls
2566 are made after the idle loop has run for some length of time (e.g.,
2567 333 mS). On some machines, this will cause a hang at boot time or
2568 whenever the CPU becomes idle. (On machines with more than one CPU,
2569 this option does nothing.)
2570
2571config APM_DISPLAY_BLANK
2572 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002573 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002574 Enable console blanking using the APM. Some laptops can use this to
2575 turn off the LCD backlight when the screen blanker of the Linux
2576 virtual console blanks the screen. Note that this is only used by
2577 the virtual console screen blanker, and won't turn off the backlight
2578 when using the X Window system. This also doesn't have anything to
2579 do with your VESA-compliant power-saving monitor. Further, this
2580 option doesn't work for all laptops -- it might not turn off your
2581 backlight at all, or it might print a lot of errors to the console,
2582 especially if you are using gpm.
2583
2584config APM_ALLOW_INTS
2585 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002586 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002587 Normally we disable external interrupts while we are making calls to
2588 the APM BIOS as a measure to lessen the effects of a badly behaving
2589 BIOS implementation. The BIOS should reenable interrupts if it
2590 needs to. Unfortunately, some BIOSes do not -- especially those in
2591 many of the newer IBM Thinkpads. If you experience hangs when you
2592 suspend, try setting this to Y. Otherwise, say N.
2593
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002594endif # APM
2595
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002596source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002597
2598source "drivers/cpuidle/Kconfig"
2599
Andy Henroid27471fd2008-10-09 11:45:22 -07002600source "drivers/idle/Kconfig"
2601
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002602endmenu
2603
2604
2605menu "Bus options (PCI etc.)"
2606
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002607choice
2608 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002609 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002610 default PCI_GOANY
2611 ---help---
2612 On PCI systems, the BIOS can be used to detect the PCI devices and
2613 determine their configuration. However, some old PCI motherboards
2614 have BIOS bugs and may crash if this is done. Also, some embedded
2615 PCI-based systems don't have any BIOS at all. Linux can also try to
2616 detect the PCI hardware directly without using the BIOS.
2617
2618 With this option, you can specify how Linux should detect the
2619 PCI devices. If you choose "BIOS", the BIOS will be used,
2620 if you choose "Direct", the BIOS won't be used, and if you
2621 choose "MMConfig", then PCI Express MMCONFIG will be used.
2622 If you choose "Any", the kernel will try MMCONFIG, then the
2623 direct access method and falls back to the BIOS if that doesn't
2624 work. If unsure, go with the default, which is "Any".
2625
2626config PCI_GOBIOS
2627 bool "BIOS"
2628
2629config PCI_GOMMCONFIG
2630 bool "MMConfig"
2631
2632config PCI_GODIRECT
2633 bool "Direct"
2634
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002635config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002636 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002637 depends on OLPC
2638
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002639config PCI_GOANY
2640 bool "Any"
2641
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002642endchoice
2643
2644config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002645 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002646 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002647
2648# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2649config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002650 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002651 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002652
2653config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002654 bool "Support mmconfig PCI config space access" if X86_64
2655 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002656 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002657 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002658
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002659config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002660 def_bool y
2661 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002662
Alex Nixonb5401a92010-03-18 16:31:34 -04002663config PCI_XEN
2664 def_bool y
2665 depends on PCI && XEN
2666 select SWIOTLB_XEN
2667
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002668config MMCONF_FAM10H
2669 def_bool y
2670 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002671
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002672config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002673 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002674 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002675 help
2676 Read the PCI windows out of the CNB20LE host bridge. This allows
2677 PCI hotplug to work on systems with the CNB20LE chipset which do
2678 not have ACPI.
2679
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002680 There's no public spec for this chipset, and this functionality
2681 is known to be incomplete.
2682
2683 You should say N unless you know you need this.
2684
William Breathitt Gray3a495512016-05-27 18:08:27 -04002685config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002686 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002687 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002688 Expose ISA bus device drivers and options available for selection and
2689 configuration. Enable this option if your target machine has an ISA
2690 bus. ISA is an older system, displaced by PCI and newer bus
2691 architectures -- if your target machine is modern, it probably does
2692 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002693
2694 If unsure, say N.
2695
David Rientjes1c00f012011-03-22 16:34:59 -07002696# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002697config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002698 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2699 default y
2700 help
2701 Enables ISA-style DMA support for devices requiring such controllers.
2702 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002703
Linus Torvalds51e68d02016-05-21 10:25:19 -07002704if X86_32
2705
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002706config ISA
2707 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002708 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002709 Find out whether you have ISA slots on your motherboard. ISA is the
2710 name of a bus system, i.e. the way the CPU talks to the other stuff
2711 inside your box. Other bus systems are PCI, EISA, MicroChannel
2712 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2713 newer boards don't support it. If you have ISA, say Y, otherwise N.
2714
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002715config SCx200
2716 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002717 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002718 This provides basic support for National Semiconductor's
2719 (now AMD's) Geode processors. The driver probes for the
2720 PCI-IDs of several on-chip devices, so its a good dependency
2721 for other scx200_* drivers.
2722
2723 If compiled as a module, the driver is named scx200.
2724
2725config SCx200HR_TIMER
2726 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002727 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002729 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002730 This driver provides a clocksource built upon the on-chip
2731 27MHz high-resolution timer. Its also a workaround for
2732 NSC Geode SC-1100's buggy TSC, which loses time when the
2733 processor goes idle (as is done by the scheduler). The
2734 other workaround is idle=poll boot option.
2735
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002736config OLPC
2737 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002738 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002739 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002740 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002741 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002742 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002743 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002744 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002745 Add support for detecting the unique features of the OLPC
2746 XO hardware.
2747
Daniel Drakea3128582011-06-25 17:34:10 +01002748config OLPC_XO1_PM
2749 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002750 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002751 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002752 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002753
Daniel Drakecfee9592011-06-25 17:34:17 +01002754config OLPC_XO1_RTC
2755 bool "OLPC XO-1 Real Time Clock"
2756 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2757 ---help---
2758 Add support for the XO-1 real time clock, which can be used as a
2759 programmable wakeup source.
2760
Daniel Drake7feda8e2011-06-25 17:34:12 +01002761config OLPC_XO1_SCI
2762 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002763 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002764 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002765 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002766 ---help---
2767 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002768 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002769 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002770 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002771 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002772 - AC adapter status updates
2773 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002774
Daniel Drakea0f30f52011-06-25 17:34:18 +01002775config OLPC_XO15_SCI
2776 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002777 depends on OLPC && ACPI
2778 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002779 ---help---
2780 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2781 - EC-driven system wakeups
2782 - AC adapter status updates
2783 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002784
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002785config ALIX
2786 bool "PCEngines ALIX System Support (LED setup)"
2787 select GPIOLIB
2788 ---help---
2789 This option enables system support for the PCEngines ALIX.
2790 At present this just sets up LEDs for GPIO control on
2791 ALIX2/3/6 boards. However, other system specific setup should
2792 get added here.
2793
2794 Note: You must still enable the drivers for GPIO and LED support
2795 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2796
2797 Note: You have to set alix.force=1 for boards with Award BIOS.
2798
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002799config NET5501
2800 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2801 select GPIOLIB
2802 ---help---
2803 This option enables system support for the Soekris Engineering net5501.
2804
Philip A. Prindeville31970592012-01-14 01:45:39 -07002805config GEOS
2806 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2807 select GPIOLIB
2808 depends on DMI
2809 ---help---
2810 This option enables system support for the Traverse Technologies GEOS.
2811
Vivien Didelot7d029122013-01-04 16:18:14 -05002812config TS5500
2813 bool "Technologic Systems TS-5500 platform support"
2814 depends on MELAN
2815 select CHECK_SIGNATURE
2816 select NEW_LEDS
2817 select LEDS_CLASS
2818 ---help---
2819 This option enables system support for the Technologic Systems TS-5500.
2820
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002821endif # X86_32
2822
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002823config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002824 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002825 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002826
David Herrmanne3263ab2013-08-02 14:05:22 +02002827config X86_SYSFB
2828 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2829 help
2830 Firmwares often provide initial graphics framebuffers so the BIOS,
2831 bootloader or kernel can show basic video-output during boot for
2832 user-guidance and debugging. Historically, x86 used the VESA BIOS
2833 Extensions and EFI-framebuffers for this, which are mostly limited
2834 to x86.
2835 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2836 framebuffers so the new generic system-framebuffer drivers can be
2837 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002838 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002839 drivers like efifb, vesafb and uvesafb can pick it up.
2840 If this option is not selected, all system framebuffers are always
2841 marked as fallback platform framebuffers as usual.
2842
2843 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2844 not be able to pick up generic system framebuffers if this option
2845 is selected. You are highly encouraged to enable simplefb as
2846 replacement if you select this option. simplefb can correctly deal
2847 with generic system framebuffers. But you should still keep vesafb
2848 and others enabled as fallback if a system framebuffer is
2849 incompatible with simplefb.
2850
2851 If unsure, say Y.
2852
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002853endmenu
2854
2855
Christoph Hellwig15724972018-07-31 13:39:30 +02002856menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002857
2858config IA32_EMULATION
2859 bool "IA32 Emulation"
2860 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002861 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002862 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002863 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002864 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002865 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002866 Include code to run legacy 32-bit programs under a
2867 64-bit kernel. You should likely turn this on, unless you're
2868 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002869
2870config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002871 tristate "IA32 a.out support"
2872 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002873 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002874 ---help---
2875 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002876
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002877config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002878 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002879 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002880 ---help---
2881 Include code to run binaries for the x32 native 32-bit ABI
2882 for 64-bit processors. An x32 process gets access to the
2883 full 64-bit register file and wide data path while leaving
2884 pointers at 32 bits for smaller memory footprint.
2885
2886 You will need a recent binutils (2.22 or later) with
2887 elf32_x86_64 support enabled to compile a kernel with this
2888 option set.
2889
Ingo Molnar953fee12016-11-15 10:22:52 +01002890config COMPAT_32
2891 def_bool y
2892 depends on IA32_EMULATION || X86_32
2893 select HAVE_UID16
2894 select OLD_SIGSUSPEND3
2895
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002896config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002897 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002898 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002899
Jan Beulich3120e252012-09-10 12:41:45 +01002900if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002901config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002902 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002903
2904config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002905 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002906 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002907endif
David Howellsee009e4a02011-03-07 15:06:20 +00002908
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002909endmenu
2910
2911
Keith Packarde5beae12008-11-03 18:21:45 +01002912config HAVE_ATOMIC_IOMAP
2913 def_bool y
2914 depends on X86_32
2915
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002916source "drivers/firmware/Kconfig"
2917
Avi Kivityedf88412007-12-16 11:02:48 +02002918source "arch/x86/kvm/Kconfig"
Jason A. Donenfeld5e8ebd82020-03-26 17:00:58 +09002919
2920source "arch/x86/Kconfig.assembler"