blob: 1a54aeb40626bbe61ac948e3eace836aef258f57 [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
Anshuman Khandual399145f2020-06-04 16:47:15 -070062 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
Dan Williams21266be2015-11-19 18:19:29 -080063 select ARCH_HAS_DEVMEM_IS_ALLOWED
Douglas Andersonb1a57bb2020-05-07 13:08:42 -070064 select ARCH_HAS_EARLY_DEBUG if KGDB
Ingo Molnar6471b822015-06-03 10:00:13 +020065 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070066 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070067 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070068 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080069 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070070 select ARCH_HAS_KCOV if X86_64
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030071 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050072 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Daniel Borkmann0ebeea82020-05-15 12:11:16 +020073 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Ingo Molnarc763ea22016-11-15 10:26:39 +010074 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070075 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070076 select ARCH_HAS_PTE_SPECIAL
Dan Williams0aed55a2017-05-29 12:22:50 -070077 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070078 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010079 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070080 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080081 select ARCH_HAS_STRICT_KERNEL_RWX
82 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050083 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Brian Gerst25c619e2020-03-13 15:51:42 -040084 select ARCH_HAS_SYSCALL_WRAPPER
Andrey Ryabininc6d30852016-01-20 15:00:55 -080085 select ARCH_HAS_UBSAN_SANITIZE_ALL
Zong Li7e01ccb2020-06-03 16:03:58 -070086 select ARCH_HAS_DEBUG_WX
Ingo Molnar6471b822015-06-03 10:00:13 +020087 select ARCH_HAVE_NMI_SAFE_CMPXCHG
88 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040089 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080090 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020091 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020092 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020093 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
95 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020096 select ARCH_USE_QUEUED_RWLOCKS
97 select ARCH_USE_QUEUED_SPINLOCKS
Mark Brown2ce0d7f2020-04-16 19:24:02 +010098 select ARCH_USE_SYM_ANNOTATIONS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070099 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Daniel Borkmann81c22042019-12-09 16:08:03 +0100100 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100101 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700102 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -0700103 select ARCH_WANTS_THP_SWAP if X86_64
Shile Zhang10916702019-12-04 08:46:31 +0800104 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200105 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200108 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700109 select EDAC_ATOMIC_SCRUB
110 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select GENERIC_CLOCKEVENTS
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_CLOCKEVENTS_MIN_ADJUST
114 select GENERIC_CMOS_UPDATE
115 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100116 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200117 select GENERIC_EARLY_IOREMAP
118 select GENERIC_FIND_FIRST_BIT
119 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200120 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200121 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200122 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200123 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200124 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200125 select GENERIC_IRQ_SHOW
126 select GENERIC_PENDING_IRQ if SMP
Steven Price2ae27132020-02-03 17:36:24 -0800127 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200128 select GENERIC_SMP_IDLE_THREAD
129 select GENERIC_STRNCPY_FROM_USER
130 select GENERIC_STRNLEN_USER
131 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100132 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000133 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700134 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Hans de Goede17e58882020-01-23 22:02:42 +0100135 select HARDIRQS_SW_RESEND
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200136 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200137 select HAVE_ACPI_APEI if ACPI
138 select HAVE_ACPI_APEI_NMI if ACPI
139 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200140 select HAVE_ARCH_AUDITSYSCALL
141 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
142 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700143 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800144 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800145 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800147 select HAVE_ARCH_MMAP_RND_BITS if MMU
148 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300149 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700150 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200151 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700152 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300153 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200154 select HAVE_ARCH_TRACEHOOK
155 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800156 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Peter Xub64d8d12020-04-20 18:13:45 -0700157 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700158 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100159 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900160 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200161 select HAVE_CMPXCHG_DOUBLE
162 select HAVE_CMPXCHG_LOCAL
163 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700164 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200165 select HAVE_C_RECORDMCOUNT
166 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700167 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400168 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900169 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500170 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800171 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700172 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100173 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700174 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700175 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400176 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200177 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200178 select HAVE_FUNCTION_GRAPH_TRACER
179 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200180 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530181 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200182 select HAVE_IDE
183 select HAVE_IOREMAP_PROT
184 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
185 select HAVE_IRQ_TIME_ACCOUNTING
186 select HAVE_KERNEL_BZIP2
187 select HAVE_KERNEL_GZIP
188 select HAVE_KERNEL_LZ4
189 select HAVE_KERNEL_LZMA
190 select HAVE_KERNEL_LZO
191 select HAVE_KERNEL_XZ
192 select HAVE_KPROBES
193 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900194 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200195 select HAVE_KRETPROBES
196 select HAVE_KVM
197 select HAVE_LIVEPATCH if X86_64
Frederic Weisbecker01027522010-04-11 18:55:56 +0200198 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500199 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800200 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700201 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200202 select HAVE_OPROFILE
203 select HAVE_OPTPROBES
204 select HAVE_PCSPKR_PLATFORM
205 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200206 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700207 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100208 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200209 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200210 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800211 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200212 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200213 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900214 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900215 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100216 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400217 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200218 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200219 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300220 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100221 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200222 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100223 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200224 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100225 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000226 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500228 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200229 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200230 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500231 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200232 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700233 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200234 select USER_STACKTRACE_SUPPORT
235 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200236 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800237 select PROC_PID_ARCH_STATUS if PROC_FS
Nayna Jain9e2b4be2020-03-08 20:57:51 -0400238 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
Balbir Singh7d8330a2008-02-10 12:46:28 +0530239
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200240config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100241 def_bool y
242 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200243
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700244config OUTPUT_FORMAT
245 string
246 default "elf32-i386" if X86_32
247 default "elf64-x86-64" if X86_64
248
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100249config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100250 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100251
252config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100253 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100254
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100255config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100256 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100257
Daniel Cashman9e08f572016-01-14 15:20:06 -0800258config ARCH_MMAP_RND_BITS_MIN
259 default 28 if 64BIT
260 default 8
261
262config ARCH_MMAP_RND_BITS_MAX
263 default 32 if 64BIT
264 default 16
265
266config ARCH_MMAP_RND_COMPAT_BITS_MIN
267 default 8
268
269config ARCH_MMAP_RND_COMPAT_BITS_MAX
270 default 16
271
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100272config SBUS
273 bool
274
275config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100276 def_bool y
277 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100278
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100279config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100280 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100281 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000282 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
283
284config GENERIC_BUG_RELATIVE_POINTERS
285 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100286
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100287config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100288 def_bool y
289 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100290
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100291config GENERIC_CALIBRATE_DELAY
292 def_bool y
293
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800294config ARCH_HAS_CPU_RELAX
295 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100296
Pekka Enberg1b27d052008-04-28 02:12:22 -0700297config ARCH_HAS_CACHE_LINE_SIZE
298 def_bool y
299
Dave Hansen316d0972018-04-20 15:20:28 -0700300config ARCH_HAS_FILTER_PGPROT
301 def_bool y
302
Mike Travisdd5af902008-01-30 13:33:32 +0100303config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900304 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100305
Tejun Heo08fc4582009-08-14 15:00:49 +0900306config NEED_PER_CPU_EMBED_FIRST_CHUNK
307 def_bool y
308
309config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900310 def_bool y
311
Johannes Berg801e4062007-12-08 02:12:39 +0100312config ARCH_HIBERNATION_POSSIBLE
313 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100314
Johannes Bergf4cb5702007-12-08 02:14:00 +0100315config ARCH_SUSPEND_POSSIBLE
316 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100317
Steve Capper53313b22013-04-30 08:03:42 +0100318config ARCH_WANT_GENERAL_HUGETLB
319 def_bool y
320
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000322 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100323
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100324config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000325 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100326
Akinobu Mita6a11f752009-03-31 15:23:17 -0700327config ARCH_SUPPORTS_DEBUG_PAGEALLOC
328 def_bool y
329
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300330config KASAN_SHADOW_OFFSET
331 hex
332 depends on KASAN
333 default 0xdffffc0000000000
334
Shane Wang69575d32009-09-01 18:25:07 -0700335config HAVE_INTEL_TXT
336 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700337 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700338
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100339config X86_32_SMP
340 def_bool y
341 depends on X86_32 && SMP
342
343config X86_64_SMP
344 def_bool y
345 depends on X86_64 && SMP
346
Tejun Heoccbeed32009-02-09 22:17:40 +0900347config X86_32_LAZY_GS
348 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900349 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900350
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530351config ARCH_SUPPORTS_UPROBES
352 def_bool y
353
Rob Herringd20642f2014-04-18 17:19:54 -0500354config FIX_EARLYCON_MEM
355 def_bool y
356
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300357config DYNAMIC_PHYSICAL_MASK
358 bool
359
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700360config PGTABLE_LEVELS
361 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300362 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700363 default 4 if X86_64
364 default 3 if X86_PAE
365 default 2
366
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900367config CC_HAS_SANE_STACKPROTECTOR
368 bool
369 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
370 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
371 help
372 We have to make sure stack protector is unconditionally disabled if
373 the compiler produces broken code.
374
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100375menu "Processor type and features"
376
Randy Dunlap5ee71532012-01-16 11:57:18 -0800377config ZONE_DMA
378 bool "DMA memory allocation support" if EXPERT
379 default y
380 help
381 DMA memory allocation support allows devices with less than 32-bit
382 addressing to allocate within the first 16MB of address space.
383 Disable if no such devices will be used.
384
385 If unsure, say Y.
386
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100387config SMP
388 bool "Symmetric multi-processing support"
389 ---help---
390 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800391 a system with only one CPU, say N. If you have a system with more
392 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100393
Robert Graffham4a474152014-01-23 15:55:29 -0800394 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100395 machines, but will use only one CPU of a multiprocessor machine. If
396 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800397 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100398 will run faster if you say N here.
399
400 Note that if you say Y here and choose architecture "586" or
401 "Pentium" under "Processor family", the kernel will not work on 486
402 architectures. Similarly, multiprocessor kernels for the "PPro"
403 architecture may not work on all Pentium based boards.
404
405 People using multiprocessor machines who say Y here should also say
406 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
407 Management" code will be disabled if you say Y here.
408
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300409 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300410 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100411 <http://www.tldp.org/docs.html#howto>.
412
413 If you don't know what to do here, say N.
414
Josh Triplett9def39be2013-10-30 08:09:45 -0700415config X86_FEATURE_NAMES
416 bool "Processor feature human-readable names" if EMBEDDED
417 default y
418 ---help---
419 This option compiles in a table of x86 feature bits and corresponding
420 names. This is required to support /proc/cpuinfo and a few kernel
421 messages. You can disable this to save space, at the expense of
422 making those few kernel messages show numeric feature bits instead.
423
424 If in doubt, say Y.
425
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800426config X86_X2APIC
427 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200428 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800429 ---help---
430 This enables x2apic support on CPUs that have this feature.
431
432 This allows 32-bit apic IDs (so it can support very large systems),
433 and accesses the local apic via MSRs not via mmio.
434
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800435 If you don't know what to do here, say N.
436
Yinghai Lu6695c852008-06-19 12:13:09 -0700437config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700438 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000439 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200440 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100441 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700442 For old smp systems that do not have proper acpi support. Newer systems
443 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700444
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000445config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100446 def_bool y
447 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000448
David Woodhouse76b04382018-01-11 21:46:25 +0000449config RETPOLINE
450 bool "Avoid speculative indirect branches in kernel"
451 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100452 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000453 help
454 Compile kernel with the retpoline compiler options to guard against
455 kernel-to-user data leaks by avoiding speculative indirect
456 branches. Requires a compiler with -mindirect-branch=thunk-extern
457 support for full protection. The kernel may run slower.
458
Johannes Weinere6d42932019-01-29 17:44:36 -0500459config X86_CPU_RESCTRL
460 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000461 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100462 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800463 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700464 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500465 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000466
467 Provide support for the allocation and monitoring of system resources
468 usage by the CPU.
469
470 Intel calls this Intel Resource Director Technology
471 (Intel(R) RDT). More information about RDT can be found in the
472 Intel x86 Architecture Software Developer Manual.
473
474 AMD calls this AMD Platform Quality of Service (AMD QoS).
475 More information about AMD QoS can be found in the AMD64 Technology
476 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700477
478 Say N if unsure.
479
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800480if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800481config X86_BIGSMP
482 bool "Support for big SMP systems with more than 8 CPUs"
483 depends on SMP
484 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -0800485 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800486
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800487config X86_EXTENDED_PLATFORM
488 bool "Support for extended (non-PC) x86 platforms"
489 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100490 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100491 If you disable this option then the kernel will only support
492 standard PC platforms. (which covers the vast majority of
493 systems out there.)
494
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800495 If you enable this option then you'll be able to select support
496 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100497 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800498 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800499 RDC R-321x SoC
500 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200501 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200502 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100503
504 If you have one of these systems, or if you want to build a
505 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800506endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100507
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800508if X86_64
509config X86_EXTENDED_PLATFORM
510 bool "Support for extended (non-PC) x86 platforms"
511 default y
512 ---help---
513 If you disable this option then the kernel will only support
514 standard PC platforms. (which covers the vast majority of
515 systems out there.)
516
517 If you enable this option then you'll be able to select support
518 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800519 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800520 ScaleMP vSMP
521 SGI Ultraviolet
522
523 If you have one of these systems, or if you want to build a
524 generic distribution kernel, say Y here - otherwise say N.
525endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800526# This is an alphabetically sorted list of 64 bit extended platforms
527# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800528config X86_NUMACHIP
529 bool "Numascale NumaChip"
530 depends on X86_64
531 depends on X86_EXTENDED_PLATFORM
532 depends on NUMA
533 depends on SMP
534 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700535 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800536 ---help---
537 Adds support for Numascale NumaChip large-SMP systems. Needed to
538 enable more than ~168 cores.
539 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100540
Ingo Molnar6a485652009-01-27 18:29:13 +0100541config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800542 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100543 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100544 select PARAVIRT
545 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800546 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300547 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100548 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100549 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
550 supposed to run on these EM64T-based machines. Only choose this option
551 if you have one of these machines.
552
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800553config X86_UV
554 bool "SGI Ultraviolet"
555 depends on X86_64
556 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500557 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800558 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700559 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200560 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800561 ---help---
562 This option is needed in order to support SGI Ultraviolet systems.
563 If you don't have one of these, you should say N here.
564
565# Following is an alphabetically sorted list of 32 bit extended platforms
566# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100567
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000568config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100569 bool "Goldfish (Virtual Platform)"
570 depends on X86_EXTENDED_PLATFORM
571 ---help---
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000572 Enable support for the Goldfish virtual platform used primarily
573 for Android development. Unless you are building for the Android
574 Goldfish emulator say N here.
575
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800576config X86_INTEL_CE
577 bool "CE4100 TV platform"
578 depends on PCI
579 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800580 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800581 depends on X86_32
582 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800583 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100584 select OF
585 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800586 ---help---
587 Select for the Intel CE media processor (CE4100) SOC.
588 This option compiles in support for the CE4100 SOC for settop
589 boxes and media devices.
590
David Cohen4cb9b002013-12-16 17:37:26 -0800591config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100592 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100593 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800594 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000595 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200596 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000597 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000598 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800599 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000600 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000601 select APB_TIMER
Mika Westerberg54b34aa2020-04-16 11:15:33 +0300602 select INTEL_SCU_PCI
Mika Westerberg15a713d2012-01-26 17:35:05 +0000603 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000604 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800605 Select to build a kernel capable of supporting Intel MID (Mobile
606 Internet Device) platform systems which do not have the PCI legacy
607 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000608
David Cohen4cb9b002013-12-16 17:37:26 -0800609 Intel MID platforms are based on an Intel processor and chipset which
610 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100611
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000612config X86_INTEL_QUARK
613 bool "Intel Quark platform support"
614 depends on X86_32
615 depends on X86_EXTENDED_PLATFORM
616 depends on X86_PLATFORM_DEVICES
617 depends on X86_TSC
618 depends on PCI
619 depends on PCI_GOANY
620 depends on X86_IO_APIC
621 select IOSF_MBI
622 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200623 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000624 ---help---
625 Select to include support for Quark X1000 SoC.
626 Say Y here if you have a Quark based system such as the Arduino
627 compatible Intel Galileo.
628
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000629config X86_INTEL_LPSS
630 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000631 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000632 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300633 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100634 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000635 ---help---
636 Select to build support for Intel Low Power Subsystem such as
637 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300638 things like clock tree (common clock framework) and pincontrol
639 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000640
Ken Xue92082a82015-02-06 08:27:51 +0800641config X86_AMD_PLATFORM_DEVICE
642 bool "AMD ACPI2Platform devices support"
643 depends on ACPI
644 select COMMON_CLK
645 select PINCTRL
646 ---help---
647 Select to interpret AMD specific ACPI device to platform device
648 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
649 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
650 implemented under PINCTRL subsystem.
651
David E. Boxced3ce72014-09-17 22:13:50 -0700652config IOSF_MBI
653 tristate "Intel SoC IOSF Sideband support for SoC platforms"
654 depends on PCI
655 ---help---
656 This option enables sideband register access support for Intel SoC
657 platforms. On these platforms the IOSF sideband is used in lieu of
658 MSR's for some register accesses, mostly but not limited to thermal
659 and power. Drivers may query the availability of this device to
660 determine if they need the sideband in order to work on these
661 platforms. The sideband is available on the following SoC products.
662 This list is not meant to be exclusive.
663 - BayTrail
664 - Braswell
665 - Quark
666
667 You should say Y if you are running a kernel on one of these SoC's.
668
David E. Boxed2226b2014-09-17 22:13:51 -0700669config IOSF_MBI_DEBUG
670 bool "Enable IOSF sideband access through debugfs"
671 depends on IOSF_MBI && DEBUG_FS
672 ---help---
673 Select this option to expose the IOSF sideband access registers (MCR,
674 MDR, MCRX) through debugfs to write and read register information from
675 different units on the SoC. This is most useful for obtaining device
676 state information for debug and analysis. As this is a general access
677 mechanism, users of this option would have specific knowledge of the
678 device they want to access.
679
680 If you don't require the option or are in doubt, say N.
681
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800682config X86_RDC321X
683 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100684 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800685 depends on X86_EXTENDED_PLATFORM
686 select M486
687 select X86_REBOOTFIXUPS
688 ---help---
689 This option is needed for RDC R-321x system-on-chip, also known
690 as R-8610-(G).
691 If you don't have one of these chips, you should say N here.
692
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100693config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100694 bool "Support non-standard 32-bit SMP architectures"
695 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800696 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100697 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800698 This option compiles in the bigsmp and STA2X11 default
699 subarchitectures. It is intended for a generic binary
700 kernel. If you select them all, kernel will probe it one by
701 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700702
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800703# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700704
Linus Torvaldsd949f362009-09-26 09:35:07 -0700705config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100706 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700707 # MCE code calls memory_failure():
708 depends on X86_MCE
709 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700710 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
711 depends on X86_64 || !SPARSEMEM
712 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700713
Alessandro Rubini83125a32012-04-04 19:40:21 +0200714config STA2X11
715 bool "STA2X11 Companion Chip Support"
716 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200717 select SWIOTLB
718 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200719 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200720 ---help---
721 This adds support for boards based on the STA2X11 IO-Hub,
722 a.k.a. "ConneXt". The chip is used in place of the standard
723 PC chipset, so all "standard" peripherals are missing. If this
724 option is selected the kernel will still be able to boot on
725 standard PC machines.
726
Shérab82148d12010-09-25 06:06:57 +0200727config X86_32_IRIS
728 tristate "Eurobraille/Iris poweroff module"
729 depends on X86_32
730 ---help---
731 The Iris machines from EuroBraille do not have APM or ACPI support
732 to shut themselves down properly. A special I/O sequence is
733 needed to do so, which is what this module does at
734 kernel shutdown.
735
736 This is only for Iris machines from EuroBraille.
737
738 If unused, say N.
739
Ingo Molnarae1e9132008-11-11 09:05:16 +0100740config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100741 def_bool y
742 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800743 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100744 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100745 Calculate simpler /proc/<PID>/wchan values. If this option
746 is disabled then wchan values will recurse back to the
747 caller function. This provides more accurate wchan values,
748 at the expense of slightly more scheduling overhead.
749
750 If in doubt, say "Y".
751
Borislav Petkov6276a072013-03-04 21:20:21 +0100752menuconfig HYPERVISOR_GUEST
753 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100754 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100755 Say Y here to enable options for running Linux under various hyper-
756 visors. This option enables basic hypervisor detection and platform
757 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100758
Borislav Petkov6276a072013-03-04 21:20:21 +0100759 If you say N, all options in this submenu will be skipped and
760 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100761
Borislav Petkov6276a072013-03-04 21:20:21 +0100762if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100763
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100764config PARAVIRT
765 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100766 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100767 This changes the kernel so it can modify itself when it is run
768 under a hypervisor, potentially improving performance significantly
769 over full virtualization. However, when run without a hypervisor
770 the kernel is theoretically slower and slightly larger.
771
Juergen Grossc00a2802018-08-28 09:40:21 +0200772config PARAVIRT_XXL
773 bool
774
Borislav Petkov6276a072013-03-04 21:20:21 +0100775config PARAVIRT_DEBUG
776 bool "paravirt-ops debugging"
777 depends on PARAVIRT && DEBUG_KERNEL
778 ---help---
779 Enable to debug paravirt_ops internals. Specifically, BUG if
780 a paravirt_op is missing when it is called.
781
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700782config PARAVIRT_SPINLOCKS
783 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700784 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700785 ---help---
786 Paravirtualized spinlocks allow a pvops backend to replace the
787 spinlock implementation with something virtualization-friendly
788 (for example, block the virtual CPU rather than spinning).
789
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530790 It has a minimal impact on native kernels and gives a nice performance
791 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700792
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530793 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700794
Zhao Yakuiecca25022019-04-30 11:45:23 +0800795config X86_HV_CALLBACK_VECTOR
796 def_bool n
797
Borislav Petkov6276a072013-03-04 21:20:21 +0100798source "arch/x86/xen/Kconfig"
799
800config KVM_GUEST
801 bool "KVM Guest support (including kvmclock)"
802 depends on PARAVIRT
803 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300804 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100805 default y
806 ---help---
807 This option enables various optimizations for running under the KVM
808 hypervisor. It includes a paravirtualized clock, so that instead
809 of relying on a PIT (or probably other) emulation by the
810 underlying device model, the host provides the guest with
811 timing infrastructure such as time of day, and system time
812
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300813config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100814 def_bool n
815 prompt "Disable host haltpoll when loading haltpoll driver"
816 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300817 If virtualized under KVM, disable host haltpoll.
818
Maran Wilson77336072018-12-10 11:07:28 -0800819config PVH
820 bool "Support for running PVH guests"
821 ---help---
822 This option enables the PVH entry point for guest virtual machines
823 as specified in the x86/HVM direct boot ABI.
824
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530825config KVM_DEBUG_FS
826 bool "Enable debug information for KVM Guests in debugfs"
827 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530828 ---help---
829 This option enables collection of various statistics for KVM guest.
830 Statistics are displayed in debugfs filesystem. Enabling this option
831 may incur significant overhead.
832
Borislav Petkov6276a072013-03-04 21:20:21 +0100833config PARAVIRT_TIME_ACCOUNTING
834 bool "Paravirtual steal time accounting"
835 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100836 ---help---
837 Select this option to enable fine granularity task steal time
838 accounting. Time spent executing other tasks in parallel with
839 the current vCPU is discounted from the vCPU power. To account for
840 that, there can be a small performance impact.
841
842 If in doubt, say N here.
843
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200844config PARAVIRT_CLOCK
845 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200846
Jan Kiszka4a362602017-11-27 09:11:46 +0100847config JAILHOUSE_GUEST
848 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100849 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100850 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100851 ---help---
852 This option allows to run Linux as guest in a Jailhouse non-root
853 cell. You can leave this option disabled if you only want to start
854 Jailhouse and run Linux afterwards in the root cell.
855
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800856config ACRN_GUEST
857 bool "ACRN Guest support"
858 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800859 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800860 help
861 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
862 a flexible, lightweight reference open-source hypervisor, built with
863 real-time and safety-criticality in mind. It is built for embedded
864 IOT with small footprint and real-time features. More details can be
865 found in https://projectacrn.org/.
866
Borislav Petkov6276a072013-03-04 21:20:21 +0100867endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400868
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100869source "arch/x86/Kconfig.cpu"
870
871config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100872 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100873 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100874 ---help---
875 Use the IA-PC HPET (High Precision Event Timer) to manage
876 time in preference to the PIT and RTC, if a HPET is
877 present.
878 HPET is the next generation timer replacing legacy 8254s.
879 The HPET provides a stable time base on SMP
880 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200881 as it is off-chip. The interface used is documented
882 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100883
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100884 You can safely choose Y here. However, HPET will only be
885 activated if the platform and the BIOS support this feature.
886 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100887
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100888 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100889
890config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100891 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800892 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100893
Jacob Panbb24c472009-09-02 07:37:17 -0700894config APB_TIMER
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100895 def_bool y if X86_INTEL_MID
896 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
897 select DW_APB_TIMER
898 depends on X86_INTEL_MID && SFI
899 help
900 APB timer is the replacement for 8254, HPET on X86 MID platforms.
901 The APBT provides a stable time base on SMP
902 systems, unlike the TSC, but it is more expensive to access,
903 as it is off-chip. APB timers are always running regardless of CPU
904 C states, they are used as per CPU clockevent device when possible.
Jacob Panbb24c472009-09-02 07:37:17 -0700905
David Rientjes6a108a12011-01-20 14:44:16 -0800906# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100907# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700908config DMI
909 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800910 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800911 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100912 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700913 Enabled scanning of DMI to identify machine quirks. Say Y
914 here unless you have verified that your setup is not
915 affected by entries in the DMI blacklist. Required by PNP
916 BIOS code.
917
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100918config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700919 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200920 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100921 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200922 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100923 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200924 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
925 GART based hardware IOMMUs.
926
927 The GART supports full DMA access for devices with 32-bit access
928 limitations, on systems with more than 3 GB. This is usually needed
929 for USB, sound, many IDE/SATA chipsets and some other devices.
930
931 Newer systems typically have a modern AMD IOMMU, supported via
932 the CONFIG_AMD_IOMMU=y config option.
933
934 In normal configurations this driver is only active when needed:
935 there's more than 3 GB of memory and the system contains a
936 32-bit limited device.
937
938 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100939
Mike Travis1184dc22008-05-12 21:21:12 +0200940config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200941 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700942 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800943 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100944 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200945 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200946 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100947
Ingo Molnaraec64872018-02-10 12:36:29 +0100948#
949# The maximum number of CPUs supported:
950#
951# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
952# and which can be configured interactively in the
953# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
954#
955# The ranges are different on 32-bit and 64-bit kernels, depending on
956# hardware capabilities and scalability features of the kernel.
957#
958# ( If MAXSMP is enabled we just use the highest possible value and disable
959# interactive configuration. )
960#
961
962config NR_CPUS_RANGE_BEGIN
963 int
964 default NR_CPUS_RANGE_END if MAXSMP
965 default 1 if !SMP
966 default 2
967
968config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800969 int
970 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100971 default 64 if SMP && X86_BIGSMP
972 default 8 if SMP && !X86_BIGSMP
973 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800974
Ingo Molnaraec64872018-02-10 12:36:29 +0100975config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800976 int
977 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500978 default 8192 if SMP && CPUMASK_OFFSTACK
979 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100980 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800981
Ingo Molnaraec64872018-02-10 12:36:29 +0100982config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800983 int
984 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100985 default 32 if X86_BIGSMP
986 default 8 if SMP
987 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800988
Ingo Molnaraec64872018-02-10 12:36:29 +0100989config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800990 int
991 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100992 default 8192 if MAXSMP
993 default 64 if SMP
994 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800995
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100996config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800997 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100998 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
999 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001000 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001001 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001002 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001003 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001004 minimum value which makes sense is 2.
1005
Ingo Molnaraec64872018-02-10 12:36:29 +01001006 This is purely to save memory: each supported CPU adds about 8KB
1007 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001008
1009config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001010 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001011
1012config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001013 def_bool y
1014 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001015 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001016 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001017 Multi-core scheduler support improves the CPU scheduler's decision
1018 making when dealing with multi-core CPU chips at a cost of slightly
1019 increased overhead in some places. If unsure say N here.
1020
Tim Chende966cf2016-11-29 10:43:27 -08001021config SCHED_MC_PRIO
1022 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001023 depends on SCHED_MC && CPU_SUP_INTEL
1024 select X86_INTEL_PSTATE
1025 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001026 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001027 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001028 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1029 core ordering determined at manufacturing time, which allows
1030 certain cores to reach higher turbo frequencies (when running
1031 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001032
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001033 Enabling this kernel feature teaches the scheduler about
1034 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1035 scheduler's CPU selection logic accordingly, so that higher
1036 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001037
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001038 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001039
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001040 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001041
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001042config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001043 def_bool y
1044 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001045
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001046config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001047 bool "Local APIC support on uniprocessors" if !PCI_MSI
1048 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001049 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001050 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001051 A local APIC (Advanced Programmable Interrupt Controller) is an
1052 integrated interrupt controller in the CPU. If you have a single-CPU
1053 system which has a processor with a local APIC, you can say Y here to
1054 enable and use it. If you say Y here even though your machine doesn't
1055 have a local APIC, then the kernel will still run with no slowdown at
1056 all. The local APIC supports CPU-generated self-interrupts (timer,
1057 performance counters), and the NMI watchdog which detects hard
1058 lockups.
1059
1060config X86_UP_IOAPIC
1061 bool "IO-APIC support on uniprocessors"
1062 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001063 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001064 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1065 SMP-capable replacement for PC-style interrupt controllers. Most
1066 SMP systems and many recent uniprocessor systems have one.
1067
1068 If you have a single-CPU system with an IO-APIC, you can say Y here
1069 to use it. If you say Y here even though your machine doesn't have
1070 an IO-APIC, then the kernel will still run with no slowdown at all.
1071
1072config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001073 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001074 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001075 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001076 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001077
1078config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001079 def_bool y
1080 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001081
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001082config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1083 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001084 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001085 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001086 This option enables a workaround that fixes a source of
1087 spurious interrupts. This is recommended when threaded
1088 interrupt handling is used on systems where the generation of
1089 superfluous "boot interrupts" cannot be disabled.
1090
1091 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1092 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1093 kernel does during interrupt handling). On chipsets where this
1094 boot IRQ generation cannot be disabled, this workaround keeps
1095 the original IRQ line masked so that only the equivalent "boot
1096 IRQ" is delivered to the CPUs. The workaround also tells the
1097 kernel to set up the IRQ handler on the boot IRQ line. In this
1098 way only one interrupt is delivered to the kernel. Otherwise
1099 the spurious second interrupt may cause the kernel to bring
1100 down (vital) interrupt lines.
1101
1102 Only affects "broken" chipsets. Interrupt sharing may be
1103 increased on these systems.
1104
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001105config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001106 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001107 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001108 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001109 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001110 Machine Check support allows the processor to notify the
1111 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001112 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001113 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001114
Tony Luck5de97c92017-03-27 11:33:03 +02001115config X86_MCELOG_LEGACY
1116 bool "Support for deprecated /dev/mcelog character device"
1117 depends on X86_MCE
1118 ---help---
1119 Enable support for /dev/mcelog which is needed by the old mcelog
1120 userspace logging daemon. Consider switching to the new generation
1121 rasdaemon solution.
1122
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001123config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001124 def_bool y
1125 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001126 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001127 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001128 Additional support for intel specific MCE features such as
1129 the thermal monitor.
1130
1131config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001132 def_bool y
1133 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001134 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001135 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001136 Additional support for AMD specific MCE features such as
1137 the DRAM Error Threshold.
1138
Andi Kleen4efc0672009-04-28 19:07:31 +02001139config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001140 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001141 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001142 ---help---
1143 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001144 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001145 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001146
Andi Kleenb2762682009-02-12 13:49:31 +01001147config X86_MCE_THRESHOLD
1148 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001149 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001150
Andi Kleenea149b32009-04-29 19:31:00 +02001151config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001152 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001153 tristate "Machine check injector support"
1154 ---help---
1155 Provide support for injecting machine checks for testing purposes.
1156 If you don't know what a machine check is and you don't do kernel
1157 QA it is safe to say n.
1158
Andi Kleen4efc0672009-04-28 19:07:31 +02001159config X86_THERMAL_VECTOR
1160 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001161 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001162
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001163source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001164
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001165config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001166 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001167 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001168 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001169 This option allows user programs to put the CPU into V8086
1170 mode, which is an 80286-era approximation of 16-bit real mode.
1171
1172 Some very old versions of X and/or vbetool require this option
1173 for user mode setting. Similarly, DOSEMU will use it if
1174 available to accelerate real mode DOS programs. However, any
1175 recent version of DOSEMU, X, or vbetool should be fully
1176 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001177 fall back to software emulation. Nevertheless, if you are using
1178 a 16-bit DOS program where 16-bit performance matters, vm86
1179 mode might be faster than emulation and you might want to
1180 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001181
Ingo Molnar1e642812015-09-05 08:58:10 +02001182 Note that any app that works on a 64-bit kernel is unlikely to
1183 need this option, as 64-bit kernels don't, and can't, support
1184 V8086 mode. This option is also unrelated to 16-bit protected
1185 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001186
Ingo Molnar1e642812015-09-05 08:58:10 +02001187 Enabling this option increases the complexity of the kernel
1188 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001189
Ingo Molnar1e642812015-09-05 08:58:10 +02001190 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001191
1192config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001193 bool
1194 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001195
1196config X86_16BIT
1197 bool "Enable support for 16-bit segments" if EXPERT
1198 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001199 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001200 ---help---
1201 This option is required by programs like Wine to run 16-bit
1202 protected mode legacy code on x86 processors. Disabling
1203 this option saves about 300 bytes on i386, or around 6K text
1204 plus 16K runtime memory on x86-64,
1205
1206config X86_ESPFIX32
1207 def_bool y
1208 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001209
H. Peter Anvin197725d2014-05-04 10:00:49 -07001210config X86_ESPFIX64
1211 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001212 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001213
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001214config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001215 bool "Enable vsyscall emulation" if EXPERT
1216 default y
1217 depends on X86_64
1218 ---help---
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001219 This enables emulation of the legacy vsyscall page. Disabling
1220 it is roughly equivalent to booting with vsyscall=none, except
1221 that it will also disable the helpful warning if a program
1222 tries to use a vsyscall. With this option set to N, offending
1223 programs will just segfault, citing addresses of the form
1224 0xffffffffff600?00.
1225
1226 This option is required by many programs built before 2013, and
1227 care should be used even with newer programs if set to N.
1228
1229 Disabling this option saves about 7K of kernel size and
1230 possibly 4K of additional runtime pagetable memory.
1231
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001232config X86_IOPL_IOPERM
1233 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001234 default y
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001235 ---help---
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001236 This enables the ioperm() and iopl() syscalls which are necessary
1237 for legacy applications.
1238
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001239 Legacy IOPL support is an overbroad mechanism which allows user
1240 space aside of accessing all 65536 I/O ports also to disable
1241 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1242 capabilities and permission from potentially active security
1243 modules.
1244
1245 The emulation restricts the functionality of the syscall to
1246 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001247 ability to disable interrupts from user space which would be
1248 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001249
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001250config TOSHIBA
1251 tristate "Toshiba Laptop support"
1252 depends on X86_32
1253 ---help---
1254 This adds a driver to safely access the System Management Mode of
1255 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256 not work on models with a Phoenix BIOS. The System Management Mode
1257 is used to set the BIOS and power saving options on Toshiba portables.
1258
1259 For information on utilities to make use of this driver see the
1260 Toshiba Linux utilities web site at:
1261 <http://www.buzzard.org.uk/toshiba/>.
1262
1263 Say Y if you intend to run this kernel on a Toshiba portable.
1264 Say N otherwise.
1265
1266config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001267 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001268 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001269 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001270 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001271 This option enables legacy /proc/i8k userspace interface in hwmon
1272 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273 temperature and allows controlling fan speeds of Dell laptops via
1274 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275 it reports also power and hotkey status. For fan speed control is
1276 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001277
Pali Rohár039ae582015-05-14 13:16:37 +02001278 Say Y if you intend to run this kernel on old Dell laptops or want to
1279 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001280 Say N otherwise.
1281
1282config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001283 bool "Enable X86 board specific fixups for reboot"
1284 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001285 ---help---
1286 This enables chipset and/or board specific fixups to be done
1287 in order to get reboot to work correctly. This is only needed on
1288 some combinations of hardware and BIOS. The symptom, for which
1289 this config is intended, is when reboot ends with a stalled/hung
1290 system.
1291
1292 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001293 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001294
1295 Say Y if you want to enable the fixup. Currently, it's safe to
1296 enable this option even if you don't need it.
1297 Say N otherwise.
1298
1299config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001300 bool "CPU microcode loading support"
1301 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001302 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001303 select FW_LOADER
1304 ---help---
1305 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001306 Intel and AMD processors. The Intel support is for the IA32 family,
1307 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1308 AMD support is for families 0x10 and later. You will obviously need
1309 the actual microcode binary data itself which is not shipped with
1310 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001312 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001313 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001314 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1315 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001316
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001317 In addition, you can build the microcode into the kernel. For that you
1318 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1319 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001320
Peter Oruba8d86f392008-07-28 18:44:21 +02001321config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001322 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001323 depends on MICROCODE
1324 default MICROCODE
1325 select FW_LOADER
1326 ---help---
1327 This options enables microcode patch loading support for Intel
1328 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001329
Alanb8989db2014-01-20 18:01:56 +00001330 For the current Intel microcode data package go to
1331 <https://downloadcenter.intel.com> and search for
1332 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001333
Peter Oruba80cc9f12008-07-28 18:44:22 +02001334config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001335 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001336 depends on MICROCODE
1337 select FW_LOADER
1338 ---help---
1339 If you select this option, microcode patch loading support for AMD
1340 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001341
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001342config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001343 bool "Ancient loading interface (DEPRECATED)"
1344 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001345 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001346 ---help---
1347 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1348 which was used by userspace tools like iucode_tool and microcode.ctl.
1349 It is inadequate because it runs too late to be able to properly
1350 load microcode on a machine and it needs special tools. Instead, you
1351 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001352 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001353
1354config X86_MSR
1355 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001356 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001357 This device gives privileged processes access to the x86
1358 Model-Specific Registers (MSRs). It is a character device with
1359 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360 MSR accesses are directed to a specific CPU on multi-processor
1361 systems.
1362
1363config X86_CPUID
1364 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001365 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001366 This device gives processes access to the x86 CPUID instruction to
1367 be executed on a specific processor. It is a character device
1368 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369 /dev/cpu/31/cpuid.
1370
1371choice
1372 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001373 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001374 depends on X86_32
1375
1376config NOHIGHMEM
1377 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001378 ---help---
1379 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380 However, the address space of 32-bit x86 processors is only 4
1381 Gigabytes large. That means that, if you have a large amount of
1382 physical memory, not all of it can be "permanently mapped" by the
1383 kernel. The physical memory that's not permanently mapped is called
1384 "high memory".
1385
1386 If you are compiling a kernel which will never run on a machine with
1387 more than 1 Gigabyte total physical RAM, answer "off" here (default
1388 choice and suitable for most users). This will result in a "3GB/1GB"
1389 split: 3GB are mapped so that each process sees a 3GB virtual memory
1390 space and the remaining part of the 4GB virtual memory space is used
1391 by the kernel to permanently map as much physical memory as
1392 possible.
1393
1394 If the machine has between 1 and 4 Gigabytes physical RAM, then
1395 answer "4GB" here.
1396
1397 If more than 4 Gigabytes is used then answer "64GB" here. This
1398 selection turns Intel PAE (Physical Address Extension) mode on.
1399 PAE implements 3-level paging on IA32 processors. PAE is fully
1400 supported by Linux, PAE mode is implemented on all recent Intel
1401 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402 then the kernel will not boot on CPUs that don't support PAE!
1403
1404 The actual amount of total physical memory will either be
1405 auto detected or can be forced by using a kernel command line option
1406 such as "mem=256M". (Try "man bootparam" or see the documentation of
1407 your boot loader (lilo or loadlin) about how to pass options to the
1408 kernel at boot time.)
1409
1410 If unsure, say "off".
1411
1412config HIGHMEM4G
1413 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001414 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001415 Select this if you have a 32-bit processor and between 1 and 4
1416 gigabytes of physical RAM.
1417
1418config HIGHMEM64G
1419 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001420 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001421 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001422 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001423 Select this if you have a 32-bit processor and more than 4
1424 gigabytes of physical RAM.
1425
1426endchoice
1427
1428choice
David Rientjes6a108a12011-01-20 14:44:16 -08001429 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001430 default VMSPLIT_3G
1431 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001432 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001433 Select the desired split between kernel and user memory.
1434
1435 If the address range available to the kernel is less than the
1436 physical memory installed, the remaining memory will be available
1437 as "high memory". Accessing high memory is a little more costly
1438 than low memory, as it needs to be mapped into the kernel first.
1439 Note that increasing the kernel address space limits the range
1440 available to user programs, making the address space there
1441 tighter. Selecting anything other than the default 3G/1G split
1442 will also likely make your kernel incompatible with binary-only
1443 kernel modules.
1444
1445 If you are not absolutely sure what you are doing, leave this
1446 option alone!
1447
1448 config VMSPLIT_3G
1449 bool "3G/1G user/kernel split"
1450 config VMSPLIT_3G_OPT
1451 depends on !X86_PAE
1452 bool "3G/1G user/kernel split (for full 1G low memory)"
1453 config VMSPLIT_2G
1454 bool "2G/2G user/kernel split"
1455 config VMSPLIT_2G_OPT
1456 depends on !X86_PAE
1457 bool "2G/2G user/kernel split (for full 2G low memory)"
1458 config VMSPLIT_1G
1459 bool "1G/3G user/kernel split"
1460endchoice
1461
1462config PAGE_OFFSET
1463 hex
1464 default 0xB0000000 if VMSPLIT_3G_OPT
1465 default 0x80000000 if VMSPLIT_2G
1466 default 0x78000000 if VMSPLIT_2G_OPT
1467 default 0x40000000 if VMSPLIT_1G
1468 default 0xC0000000
1469 depends on X86_32
1470
1471config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001472 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001473 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001474
1475config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001476 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001477 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001478 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001479 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001480 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001481 PAE is required for NX support, and furthermore enables
1482 larger swapspace support for non-overcommit purposes. It
1483 has the cost of more pagetable lookup overhead, and also
1484 consumes more pagetable space per process.
1485
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001486config X86_5LEVEL
1487 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001488 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001489 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001490 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001491 depends on X86_64
1492 ---help---
1493 5-level paging enables access to larger address space:
1494 upto 128 PiB of virtual address space and 4 PiB of
1495 physical address space.
1496
1497 It will be supported by future Intel CPUs.
1498
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001499 A kernel with the option enabled can be booted on machines that
1500 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001501
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001502 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001503 information.
1504
1505 Say N if unsure.
1506
Ingo Molnar10971ab2015-03-05 08:18:23 +01001507config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001508 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001509 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001510 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001511 Certain kernel features effectively disable kernel
1512 linear 1 GB mappings (even if the CPU otherwise
1513 supports them), so don't confuse the user by printing
1514 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001515
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001516config X86_CPA_STATISTICS
1517 bool "Enable statistic for Change Page Attribute"
1518 depends on DEBUG_FS
1519 ---help---
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001520 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001521 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001522 page mappings when mapping protections are changed.
1523
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001524config AMD_MEM_ENCRYPT
1525 bool "AMD Secure Memory Encryption (SME) support"
1526 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001527 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001528 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001529 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001530 ---help---
1531 Say yes to enable support for the encryption of system memory.
1532 This requires an AMD processor that supports Secure Memory
1533 Encryption (SME).
1534
1535config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1536 bool "Activate AMD Secure Memory Encryption (SME) by default"
1537 default y
1538 depends on AMD_MEM_ENCRYPT
1539 ---help---
1540 Say yes to have system memory encrypted by default if running on
1541 an AMD processor that supports Secure Memory Encryption (SME).
1542
1543 If set to Y, then the encryption of system memory can be
1544 deactivated with the mem_encrypt=off command line option.
1545
1546 If set to N, then the encryption of system memory can be
1547 activated with the mem_encrypt=on command line option.
1548
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001549# Common NUMA Features
1550config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001551 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001552 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001553 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001555 ---help---
Randy Dunlape133f6e2019-12-03 16:06:47 -08001556 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001557
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001558 The kernel will try to allocate memory used by a CPU on the
1559 local memory controller of the CPU and add some more
1560 NUMA awareness to the kernel.
1561
Ingo Molnarc280ea52008-11-08 13:29:45 +01001562 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001563 (or later), AMD Opteron, or EM64T NUMA.
1564
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001565 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001566 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001567
1568 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001569
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001570config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001571 def_bool y
1572 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001573 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001574 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001575 Enable AMD NUMA node topology detection. You should say Y here if
1576 you have a multi processor AMD system. This uses an old method to
1577 read the NUMA configuration directly from the builtin Northbridge
1578 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1579 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001580
1581config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001582 def_bool y
1583 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001584 depends on X86_64 && NUMA && ACPI && PCI
1585 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001586 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001587 Enable ACPI SRAT based node topology detection.
1588
1589config NUMA_EMU
1590 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001591 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001592 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001593 Enable NUMA emulation. A flat machine will be split
1594 into virtual nodes when booted with "numa=fake=N", where N is the
1595 number of nodes. This is only useful for debugging.
1596
1597config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001598 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001599 range 1 10
1600 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001601 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001602 default "3"
1603 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001604 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001605 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001606 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001607
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001608config ARCH_FLATMEM_ENABLE
1609 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001610 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001611
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001612config ARCH_SPARSEMEM_ENABLE
1613 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001614 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615 select SPARSEMEM_STATIC if X86_32
1616 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1617
Tejun Heo3b166512011-04-01 11:15:12 +02001618config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001619 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001620
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001621config ARCH_SELECT_MEMORY_MODEL
1622 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001623 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001624
1625config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001626 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001627 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001628 help
1629 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001630 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001631 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001632
Tejun Heo3b166512011-04-01 11:15:12 +02001633config ARCH_PROC_KCORE_TEXT
1634 def_bool y
1635 depends on X86_64 && PROC_KCORE
1636
Avi Kivitya29815a2010-01-10 16:28:09 +02001637config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001638 hex
1639 default 0 if X86_32
1640 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001641
Dan Williams7a678322015-08-19 00:34:34 -04001642config X86_PMEM_LEGACY_DEVICE
1643 bool
1644
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001645config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001646 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001647 depends on PHYS_ADDR_T_64BIT
1648 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001649 select X86_PMEM_LEGACY_DEVICE
Dan Williams7b27a862020-02-16 12:01:16 -08001650 select NUMA_KEEP_MEMINFO if NUMA
Dan Williams9f53f9f2015-06-09 15:33:45 -04001651 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001652 help
1653 Treat memory marked using the non-standard e820 type of 12 as used
1654 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1655 The kernel will offer these regions to the 'pmem' driver so
1656 they can be used for persistent storage.
1657
1658 Say Y if unsure.
1659
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001660config HIGHPTE
1661 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001662 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001663 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001664 The VM uses one page table entry for each page of physical memory.
1665 For systems with a lot of RAM, this can be wasteful of precious
1666 low memory. Setting this option will put user-space page table
1667 entries in high memory.
1668
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001669config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001670 bool "Check for low memory corruption"
1671 ---help---
1672 Periodically check for memory corruption in low memory, which
1673 is suspected to be caused by BIOS. Even when enabled in the
1674 configuration, it is disabled at runtime. Enable it by
1675 setting "memory_corruption_check=1" on the kernel command
1676 line. By default it scans the low 64k of memory every 60
1677 seconds; see the memory_corruption_check_size and
1678 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001679 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001680
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001681 When enabled with the default parameters, this option has
1682 almost no overhead, as it reserves a relatively small amount
1683 of memory and scans it infrequently. It both detects corruption
1684 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001685
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001686 It is, however, intended as a diagnostic tool; if repeatable
1687 BIOS-originated corruption always affects the same memory,
1688 you can use memmap= to prevent the kernel from using that
1689 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001690
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001691config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001692 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001693 depends on X86_CHECK_BIOS_CORRUPTION
1694 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001695 ---help---
1696 Set whether the default state of memory_corruption_check is
1697 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001698
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001699config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001700 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1701 default 64
1702 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001703 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001704 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001705
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001706 The first page contains BIOS data structures that the kernel
1707 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001708
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001709 By default we reserve the first 64K of physical RAM, as a
1710 number of BIOSes are known to corrupt that memory range
1711 during events such as suspend/resume or monitor cable
1712 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001713
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001714 You can set this to 4 if you are absolutely sure that you
1715 trust the BIOS to get all its memory reservations and usages
1716 right. If you know your BIOS have problems beyond the
1717 default 64K area, you can set this to 640 to avoid using the
1718 entire low memory range.
1719
1720 If you have doubts about the BIOS (e.g. suspend/resume does
1721 not work or there's kernel crashes after certain hardware
1722 hotplug events) then you might want to enable
1723 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1724 typical corruption patterns.
1725
1726 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001727
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001728config MATH_EMULATION
1729 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001730 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001731 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001732 ---help---
1733 Linux can emulate a math coprocessor (used for floating point
1734 operations) if you don't have one. 486DX and Pentium processors have
1735 a math coprocessor built in, 486SX and 386 do not, unless you added
1736 a 487DX or 387, respectively. (The messages during boot time can
1737 give you some hints here ["man dmesg"].) Everyone needs either a
1738 coprocessor or this emulation.
1739
1740 If you don't have a math coprocessor, you need to say Y here; if you
1741 say Y here even though you have a coprocessor, the coprocessor will
1742 be used nevertheless. (This behavior can be changed with the kernel
1743 command line option "no387", which comes handy if your coprocessor
1744 is broken. Try "man bootparam" or see the documentation of your boot
1745 loader (lilo or loadlin) about how to pass options to the kernel at
1746 boot time.) This means that it is a good idea to say Y here if you
1747 intend to use this kernel on different machines.
1748
1749 More information about the internals of the Linux math coprocessor
1750 emulation can be found in <file:arch/x86/math-emu/README>.
1751
1752 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1753 kernel, it won't hurt.
1754
1755config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001756 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001757 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001758 ---help---
1759 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1760 the Memory Type Range Registers (MTRRs) may be used to control
1761 processor access to memory ranges. This is most useful if you have
1762 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1763 allows bus write transfers to be combined into a larger transfer
1764 before bursting over the PCI/AGP bus. This can increase performance
1765 of image write operations 2.5 times or more. Saying Y here creates a
1766 /proc/mtrr file which may be used to manipulate your processor's
1767 MTRRs. Typically the X server should use this.
1768
1769 This code has a reasonably generic interface so that similar
1770 control registers on other processors can be easily supported
1771 as well:
1772
1773 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1774 Registers (ARRs) which provide a similar functionality to MTRRs. For
1775 these, the ARRs are used to emulate the MTRRs.
1776 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1777 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1778 write-combining. All of these processors are supported by this code
1779 and it makes sense to say Y here if you have one of them.
1780
1781 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1782 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1783 can lead to all sorts of problems, so it's good to say Y here.
1784
1785 You can safely say Y even if your machine doesn't have MTRRs, you'll
1786 just add about 9 KB to your kernel.
1787
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001788 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001789
Yinghai Lu95ffa242008-04-29 03:52:33 -07001790config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001791 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001792 prompt "MTRR cleanup support"
1793 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001794 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001795 Convert MTRR layout from continuous to discrete, so X drivers can
1796 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001797
Thomas Gleixneraba37282008-07-15 14:48:48 +02001798 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001799 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001800 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001801
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001802 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001803
1804config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001805 int "MTRR cleanup enable value (0-1)"
1806 range 0 1
1807 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001808 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001809 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001810 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001811
Yinghai Lu12031a62008-05-02 02:40:22 -07001812config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1813 int "MTRR cleanup spare reg num (0-7)"
1814 range 0 7
1815 default "1"
1816 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001817 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001818 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001819 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001820
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001821config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001822 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001823 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001824 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001825 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001826 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001827
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001828 PATs are the modern equivalents of MTRRs and are much more
1829 flexible than MTRRs.
1830
1831 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001832 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001833
1834 If unsure, say Y.
1835
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001836config ARCH_USES_PG_UNCACHED
1837 def_bool y
1838 depends on X86_PAT
1839
H. Peter Anvin628c6242011-07-31 13:59:29 -07001840config ARCH_RANDOM
1841 def_bool y
1842 prompt "x86 architectural random number generator" if EXPERT
1843 ---help---
1844 Enable the x86 architectural RDRAND instruction
1845 (Intel Bull Mountain technology) to generate random numbers.
1846 If supported, this is a high bandwidth, cryptographically
1847 secure hardware random number generator.
1848
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001849config X86_SMAP
1850 def_bool y
1851 prompt "Supervisor Mode Access Prevention" if EXPERT
1852 ---help---
1853 Supervisor Mode Access Prevention (SMAP) is a security
1854 feature in newer Intel processors. There is a small
1855 performance cost if this enabled and turned on; there is
1856 also a small increase in the kernel size if this is enabled.
1857
1858 If unsure, say Y.
1859
Babu Mogerb9718802019-11-05 21:25:32 +00001860config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001861 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001862 prompt "User Mode Instruction Prevention" if EXPERT
Ricardo Neriaa35f892017-11-05 18:27:54 -08001863 ---help---
Babu Mogerb9718802019-11-05 21:25:32 +00001864 User Mode Instruction Prevention (UMIP) is a security feature in
1865 some x86 processors. If enabled, a general protection fault is
1866 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1867 executed in user mode. These instructions unnecessarily expose
1868 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001869
1870 The vast majority of applications do not use these instructions.
1871 For the very few that do, software emulation is provided in
1872 specific cases in protected and virtual-8086 modes. Emulated
1873 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001874
Dave Hansen35e97792016-02-12 13:02:00 -08001875config X86_INTEL_MEMORY_PROTECTION_KEYS
Babu Moger38f3e772020-05-28 11:08:23 -05001876 prompt "Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001877 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001878 # Note: only available in 64-bit mode
Babu Moger38f3e772020-05-28 11:08:23 -05001879 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Ingo Molnar52c8e602016-11-15 10:15:03 +01001880 select ARCH_USES_HIGH_VMA_FLAGS
1881 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001882 ---help---
1883 Memory Protection Keys provides a mechanism for enforcing
1884 page-based protections, but without requiring modification of the
1885 page tables when an application changes protection domains.
1886
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001887 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001888
1889 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001890
Michal Hockodb616172019-10-23 12:35:50 +02001891choice
1892 prompt "TSX enable mode"
1893 depends on CPU_SUP_INTEL
1894 default X86_INTEL_TSX_MODE_OFF
1895 help
1896 Intel's TSX (Transactional Synchronization Extensions) feature
1897 allows to optimize locking protocols through lock elision which
1898 can lead to a noticeable performance boost.
1899
1900 On the other hand it has been shown that TSX can be exploited
1901 to form side channel attacks (e.g. TAA) and chances are there
1902 will be more of those attacks discovered in the future.
1903
1904 Therefore TSX is not enabled by default (aka tsx=off). An admin
1905 might override this decision by tsx=on the command line parameter.
1906 Even with TSX enabled, the kernel will attempt to enable the best
1907 possible TAA mitigation setting depending on the microcode available
1908 for the particular machine.
1909
1910 This option allows to set the default tsx mode between tsx=on, =off
1911 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1912 details.
1913
1914 Say off if not sure, auto if TSX is in use but it should be used on safe
1915 platforms or on if TSX is in use and the security aspect of tsx is not
1916 relevant.
1917
1918config X86_INTEL_TSX_MODE_OFF
1919 bool "off"
1920 help
1921 TSX is disabled if possible - equals to tsx=off command line parameter.
1922
1923config X86_INTEL_TSX_MODE_ON
1924 bool "on"
1925 help
1926 TSX is always enabled on TSX capable HW - equals the tsx=on command
1927 line parameter.
1928
1929config X86_INTEL_TSX_MODE_AUTO
1930 bool "auto"
1931 help
1932 TSX is enabled on TSX capable HW that is believed to be safe against
1933 side channel attacks- equals the tsx=auto command line parameter.
1934endchoice
1935
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001936config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001937 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001938 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001939 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001940 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001941 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001942 This enables the kernel to use EFI runtime services that are
1943 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001944
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001945 This option is only useful on systems that have EFI firmware.
1946 In addition, you should use the latest ELILO loader available
1947 at <http://elilo.sourceforge.net> in order to take advantage
1948 of EFI runtime services. However, even with this option, the
1949 resultant kernel should continue to boot on existing non-EFI
1950 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001951
Matt Fleming291f3632011-12-12 21:27:52 +00001952config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001953 bool "EFI stub support"
1954 depends on EFI && !X86_USE_3DNOW
1955 depends on $(cc-option,-mabi=ms) || X86_32
1956 select RELOCATABLE
1957 ---help---
1958 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001959 by EFI firmware without the use of a bootloader.
1960
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001961 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001962
Matt Fleming7d453ee2014-01-10 18:52:06 +00001963config EFI_MIXED
1964 bool "EFI mixed-mode support"
1965 depends on EFI_STUB && X86_64
1966 ---help---
1967 Enabling this feature allows a 64-bit kernel to be booted
1968 on a 32-bit firmware, provided that your CPU supports 64-bit
1969 mode.
1970
1971 Note that it is not possible to boot a mixed-mode enabled
1972 kernel via the EFI boot stub - a bootloader that supports
1973 the EFI handover protocol must be used.
1974
1975 If unsure, say N.
1976
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001977config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001978 def_bool y
1979 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001980 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001981 This kernel feature is useful for number crunching applications
1982 that may need to compute untrusted bytecode during their
1983 execution. By using pipes or other transports made available to
1984 the process as file descriptors supporting the read/write
1985 syscalls, it's possible to isolate those applications in
1986 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001987 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001988 and the task is only allowed to execute a few safe syscalls
1989 defined by each seccomp mode.
1990
1991 If unsure, say Y. Only embedded should say N here.
1992
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09001993source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001994
1995config KEXEC
1996 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001997 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001998 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001999 kexec is a system call that implements the ability to shutdown your
2000 current kernel, and to start another kernel. It is like a reboot
2001 but it is independent of the system firmware. And like a reboot
2002 you can start any kernel with it, not just Linux.
2003
2004 The name comes from the similarity to the exec system call.
2005
2006 It is an ongoing process to be certain the hardware in a machine
2007 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002008 initially work for you. As of this writing the exact hardware
2009 interface is strongly in flux, so no good recommendation can be
2010 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002011
Vivek Goyal74ca3172014-08-29 15:18:46 -07002012config KEXEC_FILE
2013 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002014 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002015 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002016 depends on X86_64
2017 depends on CRYPTO=y
2018 depends on CRYPTO_SHA256=y
2019 ---help---
2020 This is new version of kexec system call. This system call is
2021 file based and takes file descriptors as system call argument
2022 for kernel and initramfs as opposed to list of segments as
2023 accepted by previous system call.
2024
AKASHI Takahirob799a092018-04-13 15:35:45 -07002025config ARCH_HAS_KEXEC_PURGATORY
2026 def_bool KEXEC_FILE
2027
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002028config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002029 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002030 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002031 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002032
2033 This option makes the kexec_file_load() syscall check for a valid
2034 signature of the kernel image. The image can still be loaded without
2035 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2036 there's a signature that we can check, then it must be valid.
2037
2038 In addition to this option, you need to enable signature
2039 verification for the corresponding kernel image type being
2040 loaded in order for this to work.
2041
2042config KEXEC_SIG_FORCE
2043 bool "Require a valid signature in kexec_file_load() syscall"
2044 depends on KEXEC_SIG
2045 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002046 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002047 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002048
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002049config KEXEC_BZIMAGE_VERIFY_SIG
2050 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002051 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002052 depends on SIGNED_PE_FILE_VERIFICATION
2053 select SYSTEM_TRUSTED_KEYRING
2054 ---help---
2055 Enable bzImage signature verification support.
2056
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002057config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002058 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002059 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002060 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002061 Generate crash dump after being started by kexec.
2062 This should be normally only set in special crash dump kernels
2063 which are loaded in the main kernel with kexec-tools into
2064 a specially reserved region and then later executed after
2065 a crash by kdump/kexec. The crash dump kernel must be compiled
2066 to a memory address not used by the main kernel or BIOS using
2067 PHYSICAL_START, or it must be built as a relocatable image
2068 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002069 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002070
Huang Ying3ab83522008-07-25 19:45:07 -07002071config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002072 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002073 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002074 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002075 Jump between original kernel and kexeced kernel and invoke
2076 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002077
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002078config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002079 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002080 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002081 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002082 This gives the physical address where the kernel is loaded.
2083
2084 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2085 bzImage will decompress itself to above physical address and
2086 run from there. Otherwise, bzImage will run from the address where
2087 it has been loaded by the boot loader and will ignore above physical
2088 address.
2089
2090 In normal kdump cases one does not have to set/change this option
2091 as now bzImage can be compiled as a completely relocatable image
2092 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2093 address. This option is mainly useful for the folks who don't want
2094 to use a bzImage for capturing the crash dump and want to use a
2095 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2096 to be specifically compiled to run from a specific memory area
2097 (normally a reserved region) and this option comes handy.
2098
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002099 So if you are using bzImage for capturing the crash dump,
2100 leave the value here unchanged to 0x1000000 and set
2101 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2102 for capturing the crash dump change this value to start of
2103 the reserved region. In other words, it can be set based on
2104 the "X" value as specified in the "crashkernel=YM@XM"
2105 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002106 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002107 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002108
2109 Usage of bzImage for capturing the crash dump is recommended as
2110 one does not have to build two kernels. Same kernel can be used
2111 as production kernel and capture kernel. Above option should have
2112 gone away after relocatable bzImage support is introduced. But it
2113 is present because there are users out there who continue to use
2114 vmlinux for dump capture. This option should go away down the
2115 line.
2116
2117 Don't change this unless you know what you are doing.
2118
2119config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002120 bool "Build a relocatable kernel"
2121 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002122 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002123 This builds a kernel image that retains relocation information
2124 so it can be loaded someplace besides the default 1MB.
2125 The relocations tend to make the kernel binary about 10% larger,
2126 but are discarded at runtime.
2127
2128 One use is for the kexec on panic case where the recovery kernel
2129 must live at a different physical address than the primary
2130 kernel.
2131
2132 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2133 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002134 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002135
Kees Cook8ab38202013-10-10 17:18:14 -07002136config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002137 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002138 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002139 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002140 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002141 In support of Kernel Address Space Layout Randomization (KASLR),
2142 this randomizes the physical address at which the kernel image
2143 is decompressed and the virtual address where the kernel
2144 image is mapped, as a security feature that deters exploit
2145 attempts relying on knowledge of the location of kernel
2146 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002147
Kees Cooked9f0072016-05-25 15:45:33 -07002148 On 64-bit, the kernel physical and virtual addresses are
2149 randomized separately. The physical address will be anywhere
2150 between 16MB and the top of physical memory (up to 64TB). The
2151 virtual address will be randomized from 16MB up to 1GB (9 bits
2152 of entropy). Note that this also reduces the memory space
2153 available to kernel modules from 1.5GB to 1GB.
2154
2155 On 32-bit, the kernel physical and virtual addresses are
2156 randomized together. They will be randomized from 16MB up to
2157 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002158
Baoquan Hee8581e32016-04-20 13:55:43 -07002159 Entropy is generated using the RDRAND instruction if it is
2160 supported. If RDTSC is supported, its value is mixed into
2161 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002162 supported, then entropy is read from the i8254 timer. The
2163 usable entropy is limited by the kernel being built using
2164 2GB addressing, and that PHYSICAL_ALIGN must be at a
2165 minimum of 2MB. As a result, only 10 bits of entropy are
2166 theoretically possible, but the implementations are further
2167 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002168
Ingo Molnar6807c842017-04-18 11:08:12 +02002169 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002170
2171# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002172config X86_NEED_RELOCS
2173 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002174 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002175
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002176config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002177 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002178 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002179 range 0x2000 0x1000000 if X86_32
2180 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002181 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002182 This value puts the alignment restrictions on physical address
2183 where kernel is loaded and run from. Kernel is compiled for an
2184 address which meets above alignment restriction.
2185
2186 If bootloader loads the kernel at a non-aligned address and
2187 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2188 address aligned to above value and run from there.
2189
2190 If bootloader loads the kernel at a non-aligned address and
2191 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2192 load address and decompress itself to the address it has been
2193 compiled for and run from there. The address for which kernel is
2194 compiled already meets above alignment restrictions. Hence the
2195 end result is that kernel runs from a physical address meeting
2196 above alignment restrictions.
2197
Kees Cooka0215062013-07-08 09:15:17 -07002198 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2199 this value must be a multiple of 0x200000.
2200
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002201 Don't change this unless you know what you are doing.
2202
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002203config DYNAMIC_MEMORY_LAYOUT
2204 bool
2205 ---help---
2206 This option makes base addresses of vmalloc and vmemmap as well as
2207 __PAGE_OFFSET movable during boot.
2208
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002209config RANDOMIZE_MEMORY
2210 bool "Randomize the kernel memory sections"
2211 depends on X86_64
2212 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002213 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002214 default RANDOMIZE_BASE
2215 ---help---
2216 Randomizes the base virtual address of kernel memory sections
2217 (physical memory mapping, vmalloc & vmemmap). This security feature
2218 makes exploits relying on predictable memory locations less reliable.
2219
2220 The order of allocations remains unchanged. Entropy is generated in
2221 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2222 configuration have in average 30,000 different possible virtual
2223 addresses for each memory section.
2224
Ingo Molnar6807c842017-04-18 11:08:12 +02002225 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002226
Thomas Garnier90397a42016-06-21 17:47:06 -07002227config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2228 hex "Physical memory mapping padding" if EXPERT
2229 depends on RANDOMIZE_MEMORY
2230 default "0xa" if MEMORY_HOTPLUG
2231 default "0x0"
2232 range 0x1 0x40 if MEMORY_HOTPLUG
2233 range 0x0 0x40
2234 ---help---
2235 Define the padding in terabytes added to the existing physical
2236 memory size during kernel memory randomization. It is useful
2237 for memory hotplug support but reduces the entropy available for
2238 address randomization.
2239
2240 If unsure, leave at the default value.
2241
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002242config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002243 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002244 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002245
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002246config BOOTPARAM_HOTPLUG_CPU0
2247 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002248 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002249 ---help---
2250 Set whether default state of cpu0_hotpluggable is on or off.
2251
2252 Say Y here to enable CPU0 hotplug by default. If this switch
2253 is turned on, there is no need to give cpu0_hotplug kernel
2254 parameter and the CPU0 hotplug feature is enabled by default.
2255
2256 Please note: there are two known CPU0 dependencies if you want
2257 to enable the CPU0 hotplug feature either by this switch or by
2258 cpu0_hotplug kernel parameter.
2259
2260 First, resume from hibernate or suspend always starts from CPU0.
2261 So hibernate and suspend are prevented if CPU0 is offline.
2262
2263 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2264 offline if any interrupt can not migrate out of CPU0. There may
2265 be other CPU0 dependencies.
2266
2267 Please make sure the dependencies are under your control before
2268 you enable this feature.
2269
2270 Say N if you don't want to enable CPU0 hotplug feature by default.
2271 You still can enable the CPU0 hotplug feature at boot by kernel
2272 parameter cpu0_hotplug.
2273
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002274config DEBUG_HOTPLUG_CPU0
2275 def_bool n
2276 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002277 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002278 ---help---
2279 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2280 soon as possible and boots up userspace with CPU0 offlined. User
2281 can online CPU0 back after boot time.
2282
2283 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2284 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2285 compilation or giving cpu0_hotplug kernel parameter at boot.
2286
2287 If unsure, say N.
2288
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002289config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002290 def_bool n
2291 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002292 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002293 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002294 Certain buggy versions of glibc will crash if they are
2295 presented with a 32-bit vDSO that is not mapped at the address
2296 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002297
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002298 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2299 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2300 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2301 the only released version with the bug, but OpenSUSE 9
2302 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002303
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002304 The symptom of the bug is that everything crashes on startup, saying:
2305 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2306
2307 Saying Y here changes the default value of the vdso32 boot
2308 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2309 This works around the glibc bug but hurts performance.
2310
2311 If unsure, say N: if you are compiling your own kernel, you
2312 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002313
Kees Cook3dc33bd2015-08-12 17:55:19 -07002314choice
2315 prompt "vsyscall table for legacy applications"
2316 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002317 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002318 help
2319 Legacy user code that does not know how to find the vDSO expects
2320 to be able to issue three syscalls by calling fixed addresses in
2321 kernel space. Since this location is not randomized with ASLR,
2322 it can be used to assist security vulnerability exploitation.
2323
2324 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002325 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002326
2327 On a system with recent enough glibc (2.14 or newer) and no
2328 static binaries, you can say None without a performance penalty
2329 to improve security.
2330
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002331 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002332
Kees Cook3dc33bd2015-08-12 17:55:19 -07002333 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002334 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002335 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002336 The kernel traps and emulates calls into the fixed vsyscall
2337 address mapping. This makes the mapping non-executable, but
2338 it still contains readable known contents, which could be
2339 used in certain rare security vulnerability exploits. This
2340 configuration is recommended when using legacy userspace
2341 that still uses vsyscalls along with legacy binary
2342 instrumentation tools that require code to be readable.
2343
2344 An example of this type of legacy userspace is running
2345 Pin on an old binary that still uses vsyscalls.
2346
2347 config LEGACY_VSYSCALL_XONLY
2348 bool "Emulate execution only"
2349 help
2350 The kernel traps and emulates calls into the fixed vsyscall
2351 address mapping and does not allow reads. This
2352 configuration is recommended when userspace might use the
2353 legacy vsyscall area but support for legacy binary
2354 instrumentation of legacy code is not needed. It mitigates
2355 certain uses of the vsyscall area as an ASLR-bypassing
2356 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002357
2358 config LEGACY_VSYSCALL_NONE
2359 bool "None"
2360 help
2361 There will be no vsyscall mapping at all. This will
2362 eliminate any risk of ASLR bypass due to the vsyscall
2363 fixed address mapping. Attempts to use the vsyscalls
2364 will be reported to dmesg, so that either old or
2365 malicious userspace programs can be identified.
2366
2367endchoice
2368
Tim Bird516cbf32008-08-12 12:52:36 -07002369config CMDLINE_BOOL
2370 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002371 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002372 Allow for specifying boot arguments to the kernel at
2373 build time. On some systems (e.g. embedded ones), it is
2374 necessary or convenient to provide some or all of the
2375 kernel boot arguments with the kernel itself (that is,
2376 to not rely on the boot loader to provide them.)
2377
2378 To compile command line arguments into the kernel,
2379 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002380 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002381
2382 Systems with fully functional boot loaders (i.e. non-embedded)
2383 should leave this option set to 'N'.
2384
2385config CMDLINE
2386 string "Built-in kernel command string"
2387 depends on CMDLINE_BOOL
2388 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002389 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002390 Enter arguments here that should be compiled into the kernel
2391 image and used at boot time. If the boot loader provides a
2392 command line at boot time, it is appended to this string to
2393 form the full kernel command line, when the system boots.
2394
2395 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2396 change this behavior.
2397
2398 In most cases, the command line (whether built-in or provided
2399 by the boot loader) should specify the device for the root
2400 file system.
2401
2402config CMDLINE_OVERRIDE
2403 bool "Built-in command line overrides boot loader arguments"
Anders Roxell645e6462020-01-24 12:46:15 +01002404 depends on CMDLINE_BOOL && CMDLINE != ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002405 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002406 Set this option to 'Y' to have the kernel ignore the boot loader
2407 command line, and use ONLY the built-in command line.
2408
2409 This is used to work around broken boot loaders. This should
2410 be set to 'N' under normal conditions.
2411
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002412config MODIFY_LDT_SYSCALL
2413 bool "Enable the LDT (local descriptor table)" if EXPERT
2414 default y
2415 ---help---
2416 Linux can allow user programs to install a per-process x86
2417 Local Descriptor Table (LDT) using the modify_ldt(2) system
2418 call. This is required to run 16-bit or segmented code such as
2419 DOSEMU or some Wine programs. It is also used by some very old
2420 threading libraries.
2421
2422 Enabling this feature adds a small amount of overhead to
2423 context switches and increases the low-level kernel attack
2424 surface. Disabling it removes the modify_ldt(2) system call.
2425
2426 Saying 'N' here may make sense for embedded or server kernels.
2427
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002428source "kernel/livepatch/Kconfig"
2429
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002430endmenu
2431
Michal Hocko3072e412017-09-08 16:11:39 -07002432config ARCH_HAS_ADD_PAGES
2433 def_bool y
2434 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2435
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002436config ARCH_ENABLE_MEMORY_HOTPLUG
2437 def_bool y
2438 depends on X86_64 || (X86_32 && HIGHMEM)
2439
Gary Hade35551052008-10-31 10:52:03 -07002440config ARCH_ENABLE_MEMORY_HOTREMOVE
2441 def_bool y
2442 depends on MEMORY_HOTPLUG
2443
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002444config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002445 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002446 depends on NUMA
2447
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002448config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2449 def_bool y
2450 depends on X86_64 || X86_PAE
2451
Naoya Horiguchic177c812014-06-04 16:05:35 -07002452config ARCH_ENABLE_HUGEPAGE_MIGRATION
2453 def_bool y
2454 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2455
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002456config ARCH_ENABLE_THP_MIGRATION
2457 def_bool y
2458 depends on X86_64 && TRANSPARENT_HUGEPAGE
2459
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002460menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002461
2462config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002463 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002464 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002465
2466source "kernel/power/Kconfig"
2467
2468source "drivers/acpi/Kconfig"
2469
Feng Tangefafc8b2009-08-14 15:23:29 -04002470source "drivers/sfi/Kconfig"
2471
Andi Kleena6b68072008-01-30 13:32:49 +01002472config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002473 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002474 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002475
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002476menuconfig APM
2477 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002478 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002479 ---help---
2480 APM is a BIOS specification for saving power using several different
2481 techniques. This is mostly useful for battery powered laptops with
2482 APM compliant BIOSes. If you say Y here, the system time will be
2483 reset after a RESUME operation, the /proc/apm device will provide
2484 battery status information, and user-space programs will receive
2485 notification of APM "events" (e.g. battery status change).
2486
2487 If you select "Y" here, you can disable actual use of the APM
2488 BIOS by passing the "apm=off" option to the kernel at boot time.
2489
2490 Note that the APM support is almost completely disabled for
2491 machines with more than one CPU.
2492
2493 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002494 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002495 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002496 <http://www.tldp.org/docs.html#howto>.
2497
2498 This driver does not spin down disk drives (see the hdparm(8)
2499 manpage ("man 8 hdparm") for that), and it doesn't turn off
2500 VESA-compliant "green" monitors.
2501
2502 This driver does not support the TI 4000M TravelMate and the ACER
2503 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2504 desktop machines also don't have compliant BIOSes, and this driver
2505 may cause those machines to panic during the boot phase.
2506
2507 Generally, if you don't have a battery in your machine, there isn't
2508 much point in using this driver and you should say N. If you get
2509 random kernel OOPSes or reboots that don't seem to be related to
2510 anything, try disabling/enabling this option (or disabling/enabling
2511 APM in your BIOS).
2512
2513 Some other things you should try when experiencing seemingly random,
2514 "weird" problems:
2515
2516 1) make sure that you have enough swap space and that it is
2517 enabled.
2518 2) pass the "no-hlt" option to the kernel
2519 3) switch on floating point emulation in the kernel and pass
2520 the "no387" option to the kernel
2521 4) pass the "floppy=nodma" option to the kernel
2522 5) pass the "mem=4M" option to the kernel (thereby disabling
2523 all but the first 4 MB of RAM)
2524 6) make sure that the CPU is not over clocked.
2525 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2526 8) disable the cache from your BIOS settings
2527 9) install a fan for the video card or exchange video RAM
2528 10) install a better fan for the CPU
2529 11) exchange RAM chips
2530 12) exchange the motherboard.
2531
2532 To compile this driver as a module, choose M here: the
2533 module will be called apm.
2534
2535if APM
2536
2537config APM_IGNORE_USER_SUSPEND
2538 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002539 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002540 This option will ignore USER SUSPEND requests. On machines with a
2541 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2542 series notebooks, it is necessary to say Y because of a BIOS bug.
2543
2544config APM_DO_ENABLE
2545 bool "Enable PM at boot time"
2546 ---help---
2547 Enable APM features at boot time. From page 36 of the APM BIOS
2548 specification: "When disabled, the APM BIOS does not automatically
2549 power manage devices, enter the Standby State, enter the Suspend
2550 State, or take power saving steps in response to CPU Idle calls."
2551 This driver will make CPU Idle calls when Linux is idle (unless this
2552 feature is turned off -- see "Do CPU IDLE calls", below). This
2553 should always save battery power, but more complicated APM features
2554 will be dependent on your BIOS implementation. You may need to turn
2555 this option off if your computer hangs at boot time when using APM
2556 support, or if it beeps continuously instead of suspending. Turn
2557 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2558 T400CDT. This is off by default since most machines do fine without
2559 this feature.
2560
2561config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002562 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002563 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002564 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002565 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2566 On some machines, this can activate improved power savings, such as
2567 a slowed CPU clock rate, when the machine is idle. These idle calls
2568 are made after the idle loop has run for some length of time (e.g.,
2569 333 mS). On some machines, this will cause a hang at boot time or
2570 whenever the CPU becomes idle. (On machines with more than one CPU,
2571 this option does nothing.)
2572
2573config APM_DISPLAY_BLANK
2574 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002575 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002576 Enable console blanking using the APM. Some laptops can use this to
2577 turn off the LCD backlight when the screen blanker of the Linux
2578 virtual console blanks the screen. Note that this is only used by
2579 the virtual console screen blanker, and won't turn off the backlight
2580 when using the X Window system. This also doesn't have anything to
2581 do with your VESA-compliant power-saving monitor. Further, this
2582 option doesn't work for all laptops -- it might not turn off your
2583 backlight at all, or it might print a lot of errors to the console,
2584 especially if you are using gpm.
2585
2586config APM_ALLOW_INTS
2587 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002588 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002589 Normally we disable external interrupts while we are making calls to
2590 the APM BIOS as a measure to lessen the effects of a badly behaving
2591 BIOS implementation. The BIOS should reenable interrupts if it
2592 needs to. Unfortunately, some BIOSes do not -- especially those in
2593 many of the newer IBM Thinkpads. If you experience hangs when you
2594 suspend, try setting this to Y. Otherwise, say N.
2595
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002596endif # APM
2597
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002598source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002599
2600source "drivers/cpuidle/Kconfig"
2601
Andy Henroid27471fd2008-10-09 11:45:22 -07002602source "drivers/idle/Kconfig"
2603
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002604endmenu
2605
2606
2607menu "Bus options (PCI etc.)"
2608
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002609choice
2610 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002611 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002612 default PCI_GOANY
2613 ---help---
2614 On PCI systems, the BIOS can be used to detect the PCI devices and
2615 determine their configuration. However, some old PCI motherboards
2616 have BIOS bugs and may crash if this is done. Also, some embedded
2617 PCI-based systems don't have any BIOS at all. Linux can also try to
2618 detect the PCI hardware directly without using the BIOS.
2619
2620 With this option, you can specify how Linux should detect the
2621 PCI devices. If you choose "BIOS", the BIOS will be used,
2622 if you choose "Direct", the BIOS won't be used, and if you
2623 choose "MMConfig", then PCI Express MMCONFIG will be used.
2624 If you choose "Any", the kernel will try MMCONFIG, then the
2625 direct access method and falls back to the BIOS if that doesn't
2626 work. If unsure, go with the default, which is "Any".
2627
2628config PCI_GOBIOS
2629 bool "BIOS"
2630
2631config PCI_GOMMCONFIG
2632 bool "MMConfig"
2633
2634config PCI_GODIRECT
2635 bool "Direct"
2636
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002637config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002638 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002639 depends on OLPC
2640
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002641config PCI_GOANY
2642 bool "Any"
2643
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002644endchoice
2645
2646config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002647 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002648 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002649
2650# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2651config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002652 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002653 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002654
2655config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002656 bool "Support mmconfig PCI config space access" if X86_64
2657 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002658 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002659 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002660
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002661config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002662 def_bool y
2663 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002664
Alex Nixonb5401a92010-03-18 16:31:34 -04002665config PCI_XEN
2666 def_bool y
2667 depends on PCI && XEN
2668 select SWIOTLB_XEN
2669
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002670config MMCONF_FAM10H
2671 def_bool y
2672 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002673
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002674config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002675 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002676 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002677 help
2678 Read the PCI windows out of the CNB20LE host bridge. This allows
2679 PCI hotplug to work on systems with the CNB20LE chipset which do
2680 not have ACPI.
2681
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002682 There's no public spec for this chipset, and this functionality
2683 is known to be incomplete.
2684
2685 You should say N unless you know you need this.
2686
William Breathitt Gray3a495512016-05-27 18:08:27 -04002687config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002688 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002689 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002690 Expose ISA bus device drivers and options available for selection and
2691 configuration. Enable this option if your target machine has an ISA
2692 bus. ISA is an older system, displaced by PCI and newer bus
2693 architectures -- if your target machine is modern, it probably does
2694 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002695
2696 If unsure, say N.
2697
David Rientjes1c00f012011-03-22 16:34:59 -07002698# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002699config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002700 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2701 default y
2702 help
2703 Enables ISA-style DMA support for devices requiring such controllers.
2704 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002705
Linus Torvalds51e68d02016-05-21 10:25:19 -07002706if X86_32
2707
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002708config ISA
2709 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002710 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002711 Find out whether you have ISA slots on your motherboard. ISA is the
2712 name of a bus system, i.e. the way the CPU talks to the other stuff
2713 inside your box. Other bus systems are PCI, EISA, MicroChannel
2714 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2715 newer boards don't support it. If you have ISA, say Y, otherwise N.
2716
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002717config SCx200
2718 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002719 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002720 This provides basic support for National Semiconductor's
2721 (now AMD's) Geode processors. The driver probes for the
2722 PCI-IDs of several on-chip devices, so its a good dependency
2723 for other scx200_* drivers.
2724
2725 If compiled as a module, the driver is named scx200.
2726
2727config SCx200HR_TIMER
2728 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002729 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002730 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002731 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002732 This driver provides a clocksource built upon the on-chip
2733 27MHz high-resolution timer. Its also a workaround for
2734 NSC Geode SC-1100's buggy TSC, which loses time when the
2735 processor goes idle (as is done by the scheduler). The
2736 other workaround is idle=poll boot option.
2737
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002738config OLPC
2739 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002740 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002741 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002742 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002743 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002744 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002745 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002746 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002747 Add support for detecting the unique features of the OLPC
2748 XO hardware.
2749
Daniel Drakea3128582011-06-25 17:34:10 +01002750config OLPC_XO1_PM
2751 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002752 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002753 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002754 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002755
Daniel Drakecfee9592011-06-25 17:34:17 +01002756config OLPC_XO1_RTC
2757 bool "OLPC XO-1 Real Time Clock"
2758 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2759 ---help---
2760 Add support for the XO-1 real time clock, which can be used as a
2761 programmable wakeup source.
2762
Daniel Drake7feda8e2011-06-25 17:34:12 +01002763config OLPC_XO1_SCI
2764 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002765 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002766 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002767 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002768 ---help---
2769 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002770 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002771 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002772 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002773 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002774 - AC adapter status updates
2775 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002776
Daniel Drakea0f30f52011-06-25 17:34:18 +01002777config OLPC_XO15_SCI
2778 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002779 depends on OLPC && ACPI
2780 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002781 ---help---
2782 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2783 - EC-driven system wakeups
2784 - AC adapter status updates
2785 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002786
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002787config ALIX
2788 bool "PCEngines ALIX System Support (LED setup)"
2789 select GPIOLIB
2790 ---help---
2791 This option enables system support for the PCEngines ALIX.
2792 At present this just sets up LEDs for GPIO control on
2793 ALIX2/3/6 boards. However, other system specific setup should
2794 get added here.
2795
2796 Note: You must still enable the drivers for GPIO and LED support
2797 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2798
2799 Note: You have to set alix.force=1 for boards with Award BIOS.
2800
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002801config NET5501
2802 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2803 select GPIOLIB
2804 ---help---
2805 This option enables system support for the Soekris Engineering net5501.
2806
Philip A. Prindeville31970592012-01-14 01:45:39 -07002807config GEOS
2808 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2809 select GPIOLIB
2810 depends on DMI
2811 ---help---
2812 This option enables system support for the Traverse Technologies GEOS.
2813
Vivien Didelot7d029122013-01-04 16:18:14 -05002814config TS5500
2815 bool "Technologic Systems TS-5500 platform support"
2816 depends on MELAN
2817 select CHECK_SIGNATURE
2818 select NEW_LEDS
2819 select LEDS_CLASS
2820 ---help---
2821 This option enables system support for the Technologic Systems TS-5500.
2822
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002823endif # X86_32
2824
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002825config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002826 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002827 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002828
David Herrmanne3263ab2013-08-02 14:05:22 +02002829config X86_SYSFB
2830 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2831 help
2832 Firmwares often provide initial graphics framebuffers so the BIOS,
2833 bootloader or kernel can show basic video-output during boot for
2834 user-guidance and debugging. Historically, x86 used the VESA BIOS
2835 Extensions and EFI-framebuffers for this, which are mostly limited
2836 to x86.
2837 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2838 framebuffers so the new generic system-framebuffer drivers can be
2839 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002840 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002841 drivers like efifb, vesafb and uvesafb can pick it up.
2842 If this option is not selected, all system framebuffers are always
2843 marked as fallback platform framebuffers as usual.
2844
2845 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2846 not be able to pick up generic system framebuffers if this option
2847 is selected. You are highly encouraged to enable simplefb as
2848 replacement if you select this option. simplefb can correctly deal
2849 with generic system framebuffers. But you should still keep vesafb
2850 and others enabled as fallback if a system framebuffer is
2851 incompatible with simplefb.
2852
2853 If unsure, say Y.
2854
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002855endmenu
2856
2857
Christoph Hellwig15724972018-07-31 13:39:30 +02002858menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002859
2860config IA32_EMULATION
2861 bool "IA32 Emulation"
2862 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002863 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002864 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002865 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002866 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002867 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002868 Include code to run legacy 32-bit programs under a
2869 64-bit kernel. You should likely turn this on, unless you're
2870 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002871
2872config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002873 tristate "IA32 a.out support"
2874 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002875 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002876 ---help---
2877 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002878
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002879config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002880 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002881 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002882 ---help---
2883 Include code to run binaries for the x32 native 32-bit ABI
2884 for 64-bit processors. An x32 process gets access to the
2885 full 64-bit register file and wide data path while leaving
2886 pointers at 32 bits for smaller memory footprint.
2887
2888 You will need a recent binutils (2.22 or later) with
2889 elf32_x86_64 support enabled to compile a kernel with this
2890 option set.
2891
Ingo Molnar953fee12016-11-15 10:22:52 +01002892config COMPAT_32
2893 def_bool y
2894 depends on IA32_EMULATION || X86_32
2895 select HAVE_UID16
2896 select OLD_SIGSUSPEND3
2897
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002898config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002899 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002900 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002901
Jan Beulich3120e252012-09-10 12:41:45 +01002902if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002903config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002904 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002905
2906config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002907 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002908 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002909endif
David Howellsee009e4a02011-03-07 15:06:20 +00002910
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002911endmenu
2912
2913
Keith Packarde5beae12008-11-03 18:21:45 +01002914config HAVE_ATOMIC_IOMAP
2915 def_bool y
2916 depends on X86_32
2917
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002918source "drivers/firmware/Kconfig"
2919
Avi Kivityedf88412007-12-16 11:02:48 +02002920source "arch/x86/kvm/Kconfig"
Jason A. Donenfeld5e8ebd82020-03-26 17:00:58 +09002921
2922source "arch/x86/Kconfig.assembler"