blob: 329d9c729ba335608a4176606624cf49fb41301c [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
Ingo Molnard94e0682016-11-15 10:11:57 +010027 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
Christoph Hellwigf616ab52018-05-09 06:53:49 +020031 select NEED_DMA_MAP_STATE
Christoph Hellwig09230cb2018-04-24 09:00:54 +020032 select SWIOTLB
Dominik Brodowskif8781c42018-04-05 11:53:05 +020033 select ARCH_HAS_SYSCALL_WRAPPER
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010034
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040035config FORCE_DYNAMIC_FTRACE
36 def_bool y
37 depends on X86_32
38 depends on FUNCTION_TRACER
39 select DYNAMIC_FTRACE
40 help
41 We keep the static function tracing (!DYNAMIC_FTRACE) around
42 in order to test the non static function tracing in the
43 generic code, as other architectures still use it. But we
44 only need to keep it around for x86_64. No need to keep it
45 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010046#
47# Arch settings
48#
49# ( Note that options that are marked 'if X86_64' could in principle be
50# ported to 32-bit as well. )
51#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010052config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010053 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010054 #
55 # Note: keep this list sorted alphabetically
56 #
Ingo Molnar6471b822015-06-03 10:00:13 +020057 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030059 select ARCH_32BIT_OFF_T if X86_32
Ingo Molnar6471b822015-06-03 10:00:13 +020060 select ARCH_CLOCKSOURCE_DATA
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020061 select ARCH_CLOCKSOURCE_INIT
Ingo Molnarc763ea22016-11-15 10:26:39 +010062 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080063 select ARCH_HAS_DEBUG_VIRTUAL
Dan Williams21266be2015-11-19 18:19:29 -080064 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020065 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070066 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070067 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070068 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080069 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070070 select ARCH_HAS_KCOV if X86_64
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030071 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050072 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Ingo Molnarc763ea22016-11-15 10:26:39 +010073 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070074 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070075 select ARCH_HAS_PTE_SPECIAL
Kees Cook39208aa2017-09-02 13:09:46 -070076 select ARCH_HAS_REFCOUNT
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
Andrey Ryabininc6d30852016-01-20 15:00:55 -080084 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020085 select ARCH_HAVE_NMI_SAFE_CMPXCHG
86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040087 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080088 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020089 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020090 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020092 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
93 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select ARCH_USE_QUEUED_RWLOCKS
95 select ARCH_USE_QUEUED_SPINLOCKS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070096 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Ingo Molnarc763ea22016-11-15 10:26:39 +010097 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -070098 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -070099 select ARCH_WANTS_THP_SWAP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select BUILDTIME_EXTABLE_SORT
101 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
103 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700105 select EDAC_ATOMIC_SCRUB
106 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200107 select GENERIC_CLOCKEVENTS
108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
109 select GENERIC_CLOCKEVENTS_MIN_ADJUST
110 select GENERIC_CMOS_UPDATE
111 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100112 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200113 select GENERIC_EARLY_IOREMAP
114 select GENERIC_FIND_FIRST_BIT
115 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200118 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200120 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200121 select GENERIC_IRQ_SHOW
122 select GENERIC_PENDING_IRQ if SMP
123 select GENERIC_SMP_IDLE_THREAD
124 select GENERIC_STRNCPY_FROM_USER
125 select GENERIC_STRNLEN_USER
126 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100127 select GENERIC_GETTIMEOFDAY
Christoph Hellwig39656e82019-07-11 20:56:49 -0700128 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200129 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200130 select HAVE_ACPI_APEI if ACPI
131 select HAVE_ACPI_APEI_NMI if ACPI
132 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200133 select HAVE_ARCH_AUDITSYSCALL
134 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
135 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700136 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800137 select HAVE_ARCH_KASAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800139 select HAVE_ARCH_MMAP_RND_BITS if MMU
140 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300141 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700142 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200143 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700144 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300145 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select HAVE_ARCH_TRACEHOOK
147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700149 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100150 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900151 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select HAVE_CMPXCHG_DOUBLE
153 select HAVE_CMPXCHG_LOCAL
154 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700155 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200156 select HAVE_C_RECORDMCOUNT
157 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700158 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400159 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900160 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500161 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800162 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700163 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100164 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700165 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700166 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400167 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200168 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200169 select HAVE_FUNCTION_GRAPH_TRACER
170 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200171 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530172 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200173 select HAVE_IDE
174 select HAVE_IOREMAP_PROT
175 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
176 select HAVE_IRQ_TIME_ACCOUNTING
177 select HAVE_KERNEL_BZIP2
178 select HAVE_KERNEL_GZIP
179 select HAVE_KERNEL_LZ4
180 select HAVE_KERNEL_LZMA
181 select HAVE_KERNEL_LZO
182 select HAVE_KERNEL_XZ
183 select HAVE_KPROBES
184 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900185 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200186 select HAVE_KRETPROBES
187 select HAVE_KVM
188 select HAVE_LIVEPATCH if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200189 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200190 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500191 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800192 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700193 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200194 select HAVE_OPROFILE
195 select HAVE_OPTPROBES
196 select HAVE_PCSPKR_PLATFORM
197 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200198 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700199 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100200 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200201 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200202 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstra48a8b972018-08-22 17:30:16 +0200203 select HAVE_RCU_TABLE_FREE if PARAVIRT
Ingo Molnar6471b822015-06-03 10:00:13 +0200204 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200205 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900206 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900207 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100208 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400209 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200210 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200211 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300212 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100213 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200214 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100215 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200216 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100217 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000218 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200219 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500220 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200221 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200222 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500223 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200224 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700225 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200226 select USER_STACKTRACE_SUPPORT
227 select VIRT_TO_BUS
Ingo Molnar6471b822015-06-03 10:00:13 +0200228 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800229 select PROC_PID_ARCH_STATUS if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530230
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200231config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100232 def_bool y
233 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200234
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700235config OUTPUT_FORMAT
236 string
237 default "elf32-i386" if X86_32
238 default "elf64-x86-64" if X86_64
239
Sam Ravnborg73531902008-05-25 23:03:18 +0200240config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200241 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200242 default "arch/x86/configs/i386_defconfig" if X86_32
243 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200244
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100245config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100246 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100247
248config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100249 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100250
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100251config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100252 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253
Daniel Cashman9e08f572016-01-14 15:20:06 -0800254config ARCH_MMAP_RND_BITS_MIN
255 default 28 if 64BIT
256 default 8
257
258config ARCH_MMAP_RND_BITS_MAX
259 default 32 if 64BIT
260 default 16
261
262config ARCH_MMAP_RND_COMPAT_BITS_MIN
263 default 8
264
265config ARCH_MMAP_RND_COMPAT_BITS_MAX
266 default 16
267
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100268config SBUS
269 bool
270
271config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100272 def_bool y
273 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100274
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100275config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100276 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100277 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000278 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
279
280config GENERIC_BUG_RELATIVE_POINTERS
281 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100282
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100283config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100284 def_bool y
285 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100286
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100287config GENERIC_CALIBRATE_DELAY
288 def_bool y
289
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800290config ARCH_HAS_CPU_RELAX
291 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100292
Pekka Enberg1b27d052008-04-28 02:12:22 -0700293config ARCH_HAS_CACHE_LINE_SIZE
294 def_bool y
295
Dave Hansen316d0972018-04-20 15:20:28 -0700296config ARCH_HAS_FILTER_PGPROT
297 def_bool y
298
Mike Travisdd5af902008-01-30 13:33:32 +0100299config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900300 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100301
Tejun Heo08fc4582009-08-14 15:00:49 +0900302config NEED_PER_CPU_EMBED_FIRST_CHUNK
303 def_bool y
304
305config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900306 def_bool y
307
Johannes Berg801e4062007-12-08 02:12:39 +0100308config ARCH_HIBERNATION_POSSIBLE
309 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100310
Johannes Bergf4cb5702007-12-08 02:14:00 +0100311config ARCH_SUSPEND_POSSIBLE
312 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100313
Steve Capper53313b22013-04-30 08:03:42 +0100314config ARCH_WANT_GENERAL_HUGETLB
315 def_bool y
316
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100317config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000318 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100319
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100320config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000321 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100322
Akinobu Mita6a11f752009-03-31 15:23:17 -0700323config ARCH_SUPPORTS_DEBUG_PAGEALLOC
324 def_bool y
325
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300326config KASAN_SHADOW_OFFSET
327 hex
328 depends on KASAN
329 default 0xdffffc0000000000
330
Shane Wang69575d32009-09-01 18:25:07 -0700331config HAVE_INTEL_TXT
332 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700333 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700334
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100335config X86_32_SMP
336 def_bool y
337 depends on X86_32 && SMP
338
339config X86_64_SMP
340 def_bool y
341 depends on X86_64 && SMP
342
Tejun Heoccbeed32009-02-09 22:17:40 +0900343config X86_32_LAZY_GS
344 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900345 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900346
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530347config ARCH_SUPPORTS_UPROBES
348 def_bool y
349
Rob Herringd20642f2014-04-18 17:19:54 -0500350config FIX_EARLYCON_MEM
351 def_bool y
352
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300353config DYNAMIC_PHYSICAL_MASK
354 bool
355
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700356config PGTABLE_LEVELS
357 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300358 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700359 default 4 if X86_64
360 default 3 if X86_PAE
361 default 2
362
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900363config CC_HAS_SANE_STACKPROTECTOR
364 bool
365 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
366 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
367 help
368 We have to make sure stack protector is unconditionally disabled if
369 the compiler produces broken code.
370
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100371menu "Processor type and features"
372
Randy Dunlap5ee71532012-01-16 11:57:18 -0800373config ZONE_DMA
374 bool "DMA memory allocation support" if EXPERT
375 default y
376 help
377 DMA memory allocation support allows devices with less than 32-bit
378 addressing to allocate within the first 16MB of address space.
379 Disable if no such devices will be used.
380
381 If unsure, say Y.
382
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100383config SMP
384 bool "Symmetric multi-processing support"
385 ---help---
386 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800387 a system with only one CPU, say N. If you have a system with more
388 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100389
Robert Graffham4a474152014-01-23 15:55:29 -0800390 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100391 machines, but will use only one CPU of a multiprocessor machine. If
392 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800393 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100394 will run faster if you say N here.
395
396 Note that if you say Y here and choose architecture "586" or
397 "Pentium" under "Processor family", the kernel will not work on 486
398 architectures. Similarly, multiprocessor kernels for the "PPro"
399 architecture may not work on all Pentium based boards.
400
401 People using multiprocessor machines who say Y here should also say
402 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
403 Management" code will be disabled if you say Y here.
404
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300405 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300406 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100407 <http://www.tldp.org/docs.html#howto>.
408
409 If you don't know what to do here, say N.
410
Josh Triplett9def39be2013-10-30 08:09:45 -0700411config X86_FEATURE_NAMES
412 bool "Processor feature human-readable names" if EMBEDDED
413 default y
414 ---help---
415 This option compiles in a table of x86 feature bits and corresponding
416 names. This is required to support /proc/cpuinfo and a few kernel
417 messages. You can disable this to save space, at the expense of
418 making those few kernel messages show numeric feature bits instead.
419
420 If in doubt, say Y.
421
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800422config X86_X2APIC
423 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200424 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800425 ---help---
426 This enables x2apic support on CPUs that have this feature.
427
428 This allows 32-bit apic IDs (so it can support very large systems),
429 and accesses the local apic via MSRs not via mmio.
430
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800431 If you don't know what to do here, say N.
432
Yinghai Lu6695c852008-06-19 12:13:09 -0700433config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700434 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000435 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200436 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100437 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700438 For old smp systems that do not have proper acpi support. Newer systems
439 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700440
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000441config GOLDFISH
442 def_bool y
443 depends on X86_GOLDFISH
444
David Woodhouse76b04382018-01-11 21:46:25 +0000445config RETPOLINE
446 bool "Avoid speculative indirect branches in kernel"
447 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100448 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000449 help
450 Compile kernel with the retpoline compiler options to guard against
451 kernel-to-user data leaks by avoiding speculative indirect
452 branches. Requires a compiler with -mindirect-branch=thunk-extern
453 support for full protection. The kernel may run slower.
454
Johannes Weinere6d42932019-01-29 17:44:36 -0500455config X86_CPU_RESCTRL
456 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000457 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100458 select KERNFS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700459 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500460 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000461
462 Provide support for the allocation and monitoring of system resources
463 usage by the CPU.
464
465 Intel calls this Intel Resource Director Technology
466 (Intel(R) RDT). More information about RDT can be found in the
467 Intel x86 Architecture Software Developer Manual.
468
469 AMD calls this AMD Platform Quality of Service (AMD QoS).
470 More information about AMD QoS can be found in the AMD64 Technology
471 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700472
473 Say N if unsure.
474
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800475if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800476config X86_BIGSMP
477 bool "Support for big SMP systems with more than 8 CPUs"
478 depends on SMP
479 ---help---
480 This option is needed for the systems that have more than 8 CPUs
481
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800482config X86_EXTENDED_PLATFORM
483 bool "Support for extended (non-PC) x86 platforms"
484 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100485 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100486 If you disable this option then the kernel will only support
487 standard PC platforms. (which covers the vast majority of
488 systems out there.)
489
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800490 If you enable this option then you'll be able to select support
491 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100492 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800493 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800494 RDC R-321x SoC
495 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200496 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200497 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100498
499 If you have one of these systems, or if you want to build a
500 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800501endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100502
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800503if X86_64
504config X86_EXTENDED_PLATFORM
505 bool "Support for extended (non-PC) x86 platforms"
506 default y
507 ---help---
508 If you disable this option then the kernel will only support
509 standard PC platforms. (which covers the vast majority of
510 systems out there.)
511
512 If you enable this option then you'll be able to select support
513 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800514 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800515 ScaleMP vSMP
516 SGI Ultraviolet
517
518 If you have one of these systems, or if you want to build a
519 generic distribution kernel, say Y here - otherwise say N.
520endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800521# This is an alphabetically sorted list of 64 bit extended platforms
522# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800523config X86_NUMACHIP
524 bool "Numascale NumaChip"
525 depends on X86_64
526 depends on X86_EXTENDED_PLATFORM
527 depends on NUMA
528 depends on SMP
529 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700530 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800531 ---help---
532 Adds support for Numascale NumaChip large-SMP systems. Needed to
533 enable more than ~168 cores.
534 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100535
Ingo Molnar6a485652009-01-27 18:29:13 +0100536config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800537 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100538 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100539 select PARAVIRT
540 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800541 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300542 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100543 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100544 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
545 supposed to run on these EM64T-based machines. Only choose this option
546 if you have one of these machines.
547
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800548config X86_UV
549 bool "SGI Ultraviolet"
550 depends on X86_64
551 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500552 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800553 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700554 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200555 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800556 ---help---
557 This option is needed in order to support SGI Ultraviolet systems.
558 If you don't have one of these, you should say N here.
559
560# Following is an alphabetically sorted list of 32 bit extended platforms
561# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100562
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000563config X86_GOLDFISH
564 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100565 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000566 ---help---
567 Enable support for the Goldfish virtual platform used primarily
568 for Android development. Unless you are building for the Android
569 Goldfish emulator say N here.
570
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800571config X86_INTEL_CE
572 bool "CE4100 TV platform"
573 depends on PCI
574 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800575 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800576 depends on X86_32
577 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800578 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100579 select OF
580 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800581 ---help---
582 Select for the Intel CE media processor (CE4100) SOC.
583 This option compiles in support for the CE4100 SOC for settop
584 boxes and media devices.
585
David Cohen4cb9b002013-12-16 17:37:26 -0800586config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100587 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100588 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800589 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000590 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200591 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000592 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000593 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800594 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000595 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000596 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000597 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000598 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000599 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800600 Select to build a kernel capable of supporting Intel MID (Mobile
601 Internet Device) platform systems which do not have the PCI legacy
602 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000603
David Cohen4cb9b002013-12-16 17:37:26 -0800604 Intel MID platforms are based on an Intel processor and chipset which
605 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100606
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000607config X86_INTEL_QUARK
608 bool "Intel Quark platform support"
609 depends on X86_32
610 depends on X86_EXTENDED_PLATFORM
611 depends on X86_PLATFORM_DEVICES
612 depends on X86_TSC
613 depends on PCI
614 depends on PCI_GOANY
615 depends on X86_IO_APIC
616 select IOSF_MBI
617 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200618 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000619 ---help---
620 Select to include support for Quark X1000 SoC.
621 Say Y here if you have a Quark based system such as the Arduino
622 compatible Intel Galileo.
623
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000624config X86_INTEL_LPSS
625 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000626 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000627 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300628 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100629 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000630 ---help---
631 Select to build support for Intel Low Power Subsystem such as
632 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300633 things like clock tree (common clock framework) and pincontrol
634 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000635
Ken Xue92082a82015-02-06 08:27:51 +0800636config X86_AMD_PLATFORM_DEVICE
637 bool "AMD ACPI2Platform devices support"
638 depends on ACPI
639 select COMMON_CLK
640 select PINCTRL
641 ---help---
642 Select to interpret AMD specific ACPI device to platform device
643 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
644 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
645 implemented under PINCTRL subsystem.
646
David E. Boxced3ce72014-09-17 22:13:50 -0700647config IOSF_MBI
648 tristate "Intel SoC IOSF Sideband support for SoC platforms"
649 depends on PCI
650 ---help---
651 This option enables sideband register access support for Intel SoC
652 platforms. On these platforms the IOSF sideband is used in lieu of
653 MSR's for some register accesses, mostly but not limited to thermal
654 and power. Drivers may query the availability of this device to
655 determine if they need the sideband in order to work on these
656 platforms. The sideband is available on the following SoC products.
657 This list is not meant to be exclusive.
658 - BayTrail
659 - Braswell
660 - Quark
661
662 You should say Y if you are running a kernel on one of these SoC's.
663
David E. Boxed2226b2014-09-17 22:13:51 -0700664config IOSF_MBI_DEBUG
665 bool "Enable IOSF sideband access through debugfs"
666 depends on IOSF_MBI && DEBUG_FS
667 ---help---
668 Select this option to expose the IOSF sideband access registers (MCR,
669 MDR, MCRX) through debugfs to write and read register information from
670 different units on the SoC. This is most useful for obtaining device
671 state information for debug and analysis. As this is a general access
672 mechanism, users of this option would have specific knowledge of the
673 device they want to access.
674
675 If you don't require the option or are in doubt, say N.
676
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800677config X86_RDC321X
678 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100679 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800680 depends on X86_EXTENDED_PLATFORM
681 select M486
682 select X86_REBOOTFIXUPS
683 ---help---
684 This option is needed for RDC R-321x system-on-chip, also known
685 as R-8610-(G).
686 If you don't have one of these chips, you should say N here.
687
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100688config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100689 bool "Support non-standard 32-bit SMP architectures"
690 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800691 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100692 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800693 This option compiles in the bigsmp and STA2X11 default
694 subarchitectures. It is intended for a generic binary
695 kernel. If you select them all, kernel will probe it one by
696 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700697
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800698# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700699
Linus Torvaldsd949f362009-09-26 09:35:07 -0700700config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100701 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700702 # MCE code calls memory_failure():
703 depends on X86_MCE
704 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700705 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
706 depends on X86_64 || !SPARSEMEM
707 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700708
Alessandro Rubini83125a32012-04-04 19:40:21 +0200709config STA2X11
710 bool "STA2X11 Companion Chip Support"
711 depends on X86_32_NON_STANDARD && PCI
Christoph Hellwigb6e05472018-03-19 11:38:24 +0100712 select ARCH_HAS_PHYS_TO_DMA
Alessandro Rubini83125a32012-04-04 19:40:21 +0200713 select SWIOTLB
714 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200715 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200716 ---help---
717 This adds support for boards based on the STA2X11 IO-Hub,
718 a.k.a. "ConneXt". The chip is used in place of the standard
719 PC chipset, so all "standard" peripherals are missing. If this
720 option is selected the kernel will still be able to boot on
721 standard PC machines.
722
Shérab82148d12010-09-25 06:06:57 +0200723config X86_32_IRIS
724 tristate "Eurobraille/Iris poweroff module"
725 depends on X86_32
726 ---help---
727 The Iris machines from EuroBraille do not have APM or ACPI support
728 to shut themselves down properly. A special I/O sequence is
729 needed to do so, which is what this module does at
730 kernel shutdown.
731
732 This is only for Iris machines from EuroBraille.
733
734 If unused, say N.
735
Ingo Molnarae1e9132008-11-11 09:05:16 +0100736config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100737 def_bool y
738 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800739 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100740 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100741 Calculate simpler /proc/<PID>/wchan values. If this option
742 is disabled then wchan values will recurse back to the
743 caller function. This provides more accurate wchan values,
744 at the expense of slightly more scheduling overhead.
745
746 If in doubt, say "Y".
747
Borislav Petkov6276a072013-03-04 21:20:21 +0100748menuconfig HYPERVISOR_GUEST
749 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100750 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100751 Say Y here to enable options for running Linux under various hyper-
752 visors. This option enables basic hypervisor detection and platform
753 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100754
Borislav Petkov6276a072013-03-04 21:20:21 +0100755 If you say N, all options in this submenu will be skipped and
756 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100757
Borislav Petkov6276a072013-03-04 21:20:21 +0100758if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100759
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100760config PARAVIRT
761 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100762 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100763 This changes the kernel so it can modify itself when it is run
764 under a hypervisor, potentially improving performance significantly
765 over full virtualization. However, when run without a hypervisor
766 the kernel is theoretically slower and slightly larger.
767
Juergen Grossc00a2802018-08-28 09:40:21 +0200768config PARAVIRT_XXL
769 bool
770
Borislav Petkov6276a072013-03-04 21:20:21 +0100771config PARAVIRT_DEBUG
772 bool "paravirt-ops debugging"
773 depends on PARAVIRT && DEBUG_KERNEL
774 ---help---
775 Enable to debug paravirt_ops internals. Specifically, BUG if
776 a paravirt_op is missing when it is called.
777
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700778config PARAVIRT_SPINLOCKS
779 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700780 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700781 ---help---
782 Paravirtualized spinlocks allow a pvops backend to replace the
783 spinlock implementation with something virtualization-friendly
784 (for example, block the virtual CPU rather than spinning).
785
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530786 It has a minimal impact on native kernels and gives a nice performance
787 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700788
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530789 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700790
Zhao Yakuiecca25022019-04-30 11:45:23 +0800791config X86_HV_CALLBACK_VECTOR
792 def_bool n
793
Borislav Petkov6276a072013-03-04 21:20:21 +0100794source "arch/x86/xen/Kconfig"
795
796config KVM_GUEST
797 bool "KVM Guest support (including kvmclock)"
798 depends on PARAVIRT
799 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300800 select ARCH_CPUIDLE_HALTPOLL
Borislav Petkov6276a072013-03-04 21:20:21 +0100801 default y
802 ---help---
803 This option enables various optimizations for running under the KVM
804 hypervisor. It includes a paravirtualized clock, so that instead
805 of relying on a PIT (or probably other) emulation by the
806 underlying device model, the host provides the guest with
807 timing infrastructure such as time of day, and system time
808
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300809config ARCH_CPUIDLE_HALTPOLL
810 def_bool n
811 prompt "Disable host haltpoll when loading haltpoll driver"
812 help
813 If virtualized under KVM, disable host haltpoll.
814
Maran Wilson77336072018-12-10 11:07:28 -0800815config PVH
816 bool "Support for running PVH guests"
817 ---help---
818 This option enables the PVH entry point for guest virtual machines
819 as specified in the x86/HVM direct boot ABI.
820
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530821config KVM_DEBUG_FS
822 bool "Enable debug information for KVM Guests in debugfs"
823 depends on KVM_GUEST && DEBUG_FS
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530824 ---help---
825 This option enables collection of various statistics for KVM guest.
826 Statistics are displayed in debugfs filesystem. Enabling this option
827 may incur significant overhead.
828
Borislav Petkov6276a072013-03-04 21:20:21 +0100829config PARAVIRT_TIME_ACCOUNTING
830 bool "Paravirtual steal time accounting"
831 depends on PARAVIRT
Borislav Petkov6276a072013-03-04 21:20:21 +0100832 ---help---
833 Select this option to enable fine granularity task steal time
834 accounting. Time spent executing other tasks in parallel with
835 the current vCPU is discounted from the vCPU power. To account for
836 that, there can be a small performance impact.
837
838 If in doubt, say N here.
839
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200840config PARAVIRT_CLOCK
841 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200842
Jan Kiszka4a362602017-11-27 09:11:46 +0100843config JAILHOUSE_GUEST
844 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100845 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100846 select X86_PM_TIMER
Jan Kiszka4a362602017-11-27 09:11:46 +0100847 ---help---
848 This option allows to run Linux as guest in a Jailhouse non-root
849 cell. You can leave this option disabled if you only want to start
850 Jailhouse and run Linux afterwards in the root cell.
851
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800852config ACRN_GUEST
853 bool "ACRN Guest support"
854 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800855 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800856 help
857 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
858 a flexible, lightweight reference open-source hypervisor, built with
859 real-time and safety-criticality in mind. It is built for embedded
860 IOT with small footprint and real-time features. More details can be
861 found in https://projectacrn.org/.
862
Borislav Petkov6276a072013-03-04 21:20:21 +0100863endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400864
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100865source "arch/x86/Kconfig.cpu"
866
867config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100868 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100869 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100870 ---help---
871 Use the IA-PC HPET (High Precision Event Timer) to manage
872 time in preference to the PIT and RTC, if a HPET is
873 present.
874 HPET is the next generation timer replacing legacy 8254s.
875 The HPET provides a stable time base on SMP
876 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200877 as it is off-chip. The interface used is documented
878 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100879
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100880 You can safely choose Y here. However, HPET will only be
881 activated if the platform and the BIOS support this feature.
882 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100883
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100884 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100885
886config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100887 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800888 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100889
Jacob Panbb24c472009-09-02 07:37:17 -0700890config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000891 def_bool y if X86_INTEL_MID
892 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100893 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000894 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700895 help
896 APB timer is the replacement for 8254, HPET on X86 MID platforms.
897 The APBT provides a stable time base on SMP
898 systems, unlike the TSC, but it is more expensive to access,
899 as it is off-chip. APB timers are always running regardless of CPU
900 C states, they are used as per CPU clockevent device when possible.
901
David Rientjes6a108a12011-01-20 14:44:16 -0800902# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100903# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700904config DMI
905 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800906 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800907 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100908 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700909 Enabled scanning of DMI to identify machine quirks. Say Y
910 here unless you have verified that your setup is not
911 affected by entries in the DMI blacklist. Required by PNP
912 BIOS code.
913
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100914config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700915 bool "Old AMD GART IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200916 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100917 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200918 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100919 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921 GART based hardware IOMMUs.
922
923 The GART supports full DMA access for devices with 32-bit access
924 limitations, on systems with more than 3 GB. This is usually needed
925 for USB, sound, many IDE/SATA chipsets and some other devices.
926
927 Newer systems typically have a modern AMD IOMMU, supported via
928 the CONFIG_AMD_IOMMU=y config option.
929
930 In normal configurations this driver is only active when needed:
931 there's more than 3 GB of memory and the system contains a
932 32-bit limited device.
933
934 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100935
936config CALGARY_IOMMU
937 bool "IBM Calgary IOMMU support"
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200938 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100939 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700940 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100941 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100942 Support for hardware IOMMUs in IBM's xSeries x366 and x460
943 systems. Needed to run systems with more than 3GB of memory
944 properly with 32-bit PCI devices that do not support DAC
945 (Double Address Cycle). Calgary also supports bus level
946 isolation, where all DMAs pass through the IOMMU. This
947 prevents them from going anywhere except their intended
948 destination. This catches hard-to-find kernel bugs and
949 mis-behaving drivers and devices that do not use the DMA-API
950 properly to set up their DMA buffers. The IOMMU can be
951 turned off at boot time with the iommu=off parameter.
952 Normally the kernel will make the right choice by itself.
953 If unsure, say Y.
954
955config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100956 def_bool y
957 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100958 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100959 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100960 Should Calgary be enabled by default? if you choose 'y', Calgary
961 will be used (if it exists). If you choose 'n', Calgary will not be
962 used even if it exists. If you choose 'n' and would like to use
963 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
964 If unsure, say Y.
965
Mike Travis1184dc22008-05-12 21:21:12 +0200966config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200967 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700968 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800969 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100970 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200971 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200972 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100973
Ingo Molnaraec64872018-02-10 12:36:29 +0100974#
975# The maximum number of CPUs supported:
976#
977# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
978# and which can be configured interactively in the
979# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
980#
981# The ranges are different on 32-bit and 64-bit kernels, depending on
982# hardware capabilities and scalability features of the kernel.
983#
984# ( If MAXSMP is enabled we just use the highest possible value and disable
985# interactive configuration. )
986#
987
988config NR_CPUS_RANGE_BEGIN
989 int
990 default NR_CPUS_RANGE_END if MAXSMP
991 default 1 if !SMP
992 default 2
993
994config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800995 int
996 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100997 default 64 if SMP && X86_BIGSMP
998 default 8 if SMP && !X86_BIGSMP
999 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001000
Ingo Molnaraec64872018-02-10 12:36:29 +01001001config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001002 int
1003 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001004 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
1005 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
1006 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001007
Ingo Molnaraec64872018-02-10 12:36:29 +01001008config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001009 int
1010 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +01001011 default 32 if X86_BIGSMP
1012 default 8 if SMP
1013 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001014
Ingo Molnaraec64872018-02-10 12:36:29 +01001015config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001016 int
1017 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +01001018 default 8192 if MAXSMP
1019 default 64 if SMP
1020 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -08001021
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001022config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -08001023 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +01001024 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1025 default NR_CPUS_DEFAULT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001026 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001027 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -05001028 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +03001029 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001030 minimum value which makes sense is 2.
1031
Ingo Molnaraec64872018-02-10 12:36:29 +01001032 This is purely to save memory: each supported CPU adds about 8KB
1033 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001034
1035config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001036 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001037
1038config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001039 def_bool y
1040 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001041 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001042 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001043 Multi-core scheduler support improves the CPU scheduler's decision
1044 making when dealing with multi-core CPU chips at a cost of slightly
1045 increased overhead in some places. If unsure say N here.
1046
Tim Chende966cf2016-11-29 10:43:27 -08001047config SCHED_MC_PRIO
1048 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001049 depends on SCHED_MC && CPU_SUP_INTEL
1050 select X86_INTEL_PSTATE
1051 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001052 default y
Tim Chen5e76b2a2016-11-22 12:23:55 -08001053 ---help---
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001054 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1055 core ordering determined at manufacturing time, which allows
1056 certain cores to reach higher turbo frequencies (when running
1057 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001058
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001059 Enabling this kernel feature teaches the scheduler about
1060 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1061 scheduler's CPU selection logic accordingly, so that higher
1062 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001063
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001064 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001065
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001066 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001067
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001068config UP_LATE_INIT
1069 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +01001070 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001071
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001072config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001073 bool "Local APIC support on uniprocessors" if !PCI_MSI
1074 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001075 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001076 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001077 A local APIC (Advanced Programmable Interrupt Controller) is an
1078 integrated interrupt controller in the CPU. If you have a single-CPU
1079 system which has a processor with a local APIC, you can say Y here to
1080 enable and use it. If you say Y here even though your machine doesn't
1081 have a local APIC, then the kernel will still run with no slowdown at
1082 all. The local APIC supports CPU-generated self-interrupts (timer,
1083 performance counters), and the NMI watchdog which detects hard
1084 lockups.
1085
1086config X86_UP_IOAPIC
1087 bool "IO-APIC support on uniprocessors"
1088 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001089 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001090 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1091 SMP-capable replacement for PC-style interrupt controllers. Most
1092 SMP systems and many recent uniprocessor systems have one.
1093
1094 If you have a single-CPU system with an IO-APIC, you can say Y here
1095 to use it. If you say Y here even though your machine doesn't have
1096 an IO-APIC, then the kernel will still run with no slowdown at all.
1097
1098config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001099 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001100 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001101 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001102 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001103
1104config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001105 def_bool y
1106 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001107
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001108config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1109 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001110 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001111 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001112 This option enables a workaround that fixes a source of
1113 spurious interrupts. This is recommended when threaded
1114 interrupt handling is used on systems where the generation of
1115 superfluous "boot interrupts" cannot be disabled.
1116
1117 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1118 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1119 kernel does during interrupt handling). On chipsets where this
1120 boot IRQ generation cannot be disabled, this workaround keeps
1121 the original IRQ line masked so that only the equivalent "boot
1122 IRQ" is delivered to the CPUs. The workaround also tells the
1123 kernel to set up the IRQ handler on the boot IRQ line. In this
1124 way only one interrupt is delivered to the kernel. Otherwise
1125 the spurious second interrupt may cause the kernel to bring
1126 down (vital) interrupt lines.
1127
1128 Only affects "broken" chipsets. Interrupt sharing may be
1129 increased on these systems.
1130
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001131config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001132 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001133 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001134 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001135 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001136 Machine Check support allows the processor to notify the
1137 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001138 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001139 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001140
Tony Luck5de97c92017-03-27 11:33:03 +02001141config X86_MCELOG_LEGACY
1142 bool "Support for deprecated /dev/mcelog character device"
1143 depends on X86_MCE
1144 ---help---
1145 Enable support for /dev/mcelog which is needed by the old mcelog
1146 userspace logging daemon. Consider switching to the new generation
1147 rasdaemon solution.
1148
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001149config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001150 def_bool y
1151 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001152 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001153 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001154 Additional support for intel specific MCE features such as
1155 the thermal monitor.
1156
1157config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001158 def_bool y
1159 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001160 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001161 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001162 Additional support for AMD specific MCE features such as
1163 the DRAM Error Threshold.
1164
Andi Kleen4efc0672009-04-28 19:07:31 +02001165config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001166 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001167 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001168 ---help---
1169 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001170 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001171 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001172
Andi Kleenb2762682009-02-12 13:49:31 +01001173config X86_MCE_THRESHOLD
1174 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001175 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001176
Andi Kleenea149b32009-04-29 19:31:00 +02001177config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001178 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001179 tristate "Machine check injector support"
1180 ---help---
1181 Provide support for injecting machine checks for testing purposes.
1182 If you don't know what a machine check is and you don't do kernel
1183 QA it is safe to say n.
1184
Andi Kleen4efc0672009-04-28 19:07:31 +02001185config X86_THERMAL_VECTOR
1186 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001187 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001188
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001189source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001190
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001191config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001192 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001193 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001194 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001195 This option allows user programs to put the CPU into V8086
1196 mode, which is an 80286-era approximation of 16-bit real mode.
1197
1198 Some very old versions of X and/or vbetool require this option
1199 for user mode setting. Similarly, DOSEMU will use it if
1200 available to accelerate real mode DOS programs. However, any
1201 recent version of DOSEMU, X, or vbetool should be fully
1202 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001203 fall back to software emulation. Nevertheless, if you are using
1204 a 16-bit DOS program where 16-bit performance matters, vm86
1205 mode might be faster than emulation and you might want to
1206 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001207
Ingo Molnar1e642812015-09-05 08:58:10 +02001208 Note that any app that works on a 64-bit kernel is unlikely to
1209 need this option, as 64-bit kernels don't, and can't, support
1210 V8086 mode. This option is also unrelated to 16-bit protected
1211 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001212
Ingo Molnar1e642812015-09-05 08:58:10 +02001213 Enabling this option increases the complexity of the kernel
1214 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001215
Ingo Molnar1e642812015-09-05 08:58:10 +02001216 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001217
1218config VM86
1219 bool
1220 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001221
1222config X86_16BIT
1223 bool "Enable support for 16-bit segments" if EXPERT
1224 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001225 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001226 ---help---
1227 This option is required by programs like Wine to run 16-bit
1228 protected mode legacy code on x86 processors. Disabling
1229 this option saves about 300 bytes on i386, or around 6K text
1230 plus 16K runtime memory on x86-64,
1231
1232config X86_ESPFIX32
1233 def_bool y
1234 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001235
H. Peter Anvin197725d2014-05-04 10:00:49 -07001236config X86_ESPFIX64
1237 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001238 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001239
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001240config X86_VSYSCALL_EMULATION
1241 bool "Enable vsyscall emulation" if EXPERT
1242 default y
1243 depends on X86_64
1244 ---help---
1245 This enables emulation of the legacy vsyscall page. Disabling
1246 it is roughly equivalent to booting with vsyscall=none, except
1247 that it will also disable the helpful warning if a program
1248 tries to use a vsyscall. With this option set to N, offending
1249 programs will just segfault, citing addresses of the form
1250 0xffffffffff600?00.
1251
1252 This option is required by many programs built before 2013, and
1253 care should be used even with newer programs if set to N.
1254
1255 Disabling this option saves about 7K of kernel size and
1256 possibly 4K of additional runtime pagetable memory.
1257
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001258config TOSHIBA
1259 tristate "Toshiba Laptop support"
1260 depends on X86_32
1261 ---help---
1262 This adds a driver to safely access the System Management Mode of
1263 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1264 not work on models with a Phoenix BIOS. The System Management Mode
1265 is used to set the BIOS and power saving options on Toshiba portables.
1266
1267 For information on utilities to make use of this driver see the
1268 Toshiba Linux utilities web site at:
1269 <http://www.buzzard.org.uk/toshiba/>.
1270
1271 Say Y if you intend to run this kernel on a Toshiba portable.
1272 Say N otherwise.
1273
1274config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001275 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001276 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001277 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001278 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001279 This option enables legacy /proc/i8k userspace interface in hwmon
1280 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1281 temperature and allows controlling fan speeds of Dell laptops via
1282 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1283 it reports also power and hotkey status. For fan speed control is
1284 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001285
Pali Rohár039ae582015-05-14 13:16:37 +02001286 Say Y if you intend to run this kernel on old Dell laptops or want to
1287 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001288 Say N otherwise.
1289
1290config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001291 bool "Enable X86 board specific fixups for reboot"
1292 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001293 ---help---
1294 This enables chipset and/or board specific fixups to be done
1295 in order to get reboot to work correctly. This is only needed on
1296 some combinations of hardware and BIOS. The symptom, for which
1297 this config is intended, is when reboot ends with a stalled/hung
1298 system.
1299
1300 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001301 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001302
1303 Say Y if you want to enable the fixup. Currently, it's safe to
1304 enable this option even if you don't need it.
1305 Say N otherwise.
1306
1307config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001308 bool "CPU microcode loading support"
1309 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001310 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311 select FW_LOADER
1312 ---help---
1313 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001314 Intel and AMD processors. The Intel support is for the IA32 family,
1315 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1316 AMD support is for families 0x10 and later. You will obviously need
1317 the actual microcode binary data itself which is not shipped with
1318 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001319
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001320 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001321 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001322 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1323 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001324
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001325 In addition, you can build the microcode into the kernel. For that you
1326 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1327 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001328
Peter Oruba8d86f392008-07-28 18:44:21 +02001329config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001330 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001331 depends on MICROCODE
1332 default MICROCODE
1333 select FW_LOADER
1334 ---help---
1335 This options enables microcode patch loading support for Intel
1336 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001337
Alanb8989db2014-01-20 18:01:56 +00001338 For the current Intel microcode data package go to
1339 <https://downloadcenter.intel.com> and search for
1340 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001341
Peter Oruba80cc9f12008-07-28 18:44:22 +02001342config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001343 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001344 depends on MICROCODE
1345 select FW_LOADER
1346 ---help---
1347 If you select this option, microcode patch loading support for AMD
1348 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001349
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001350config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001351 bool "Ancient loading interface (DEPRECATED)"
1352 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001353 depends on MICROCODE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001354 ---help---
1355 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1356 which was used by userspace tools like iucode_tool and microcode.ctl.
1357 It is inadequate because it runs too late to be able to properly
1358 load microcode on a machine and it needs special tools. Instead, you
1359 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001360 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001361
1362config X86_MSR
1363 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001364 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001365 This device gives privileged processes access to the x86
1366 Model-Specific Registers (MSRs). It is a character device with
1367 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1368 MSR accesses are directed to a specific CPU on multi-processor
1369 systems.
1370
1371config X86_CPUID
1372 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001373 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001374 This device gives processes access to the x86 CPUID instruction to
1375 be executed on a specific processor. It is a character device
1376 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1377 /dev/cpu/31/cpuid.
1378
1379choice
1380 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001381 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001382 depends on X86_32
1383
1384config NOHIGHMEM
1385 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001386 ---help---
1387 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1388 However, the address space of 32-bit x86 processors is only 4
1389 Gigabytes large. That means that, if you have a large amount of
1390 physical memory, not all of it can be "permanently mapped" by the
1391 kernel. The physical memory that's not permanently mapped is called
1392 "high memory".
1393
1394 If you are compiling a kernel which will never run on a machine with
1395 more than 1 Gigabyte total physical RAM, answer "off" here (default
1396 choice and suitable for most users). This will result in a "3GB/1GB"
1397 split: 3GB are mapped so that each process sees a 3GB virtual memory
1398 space and the remaining part of the 4GB virtual memory space is used
1399 by the kernel to permanently map as much physical memory as
1400 possible.
1401
1402 If the machine has between 1 and 4 Gigabytes physical RAM, then
1403 answer "4GB" here.
1404
1405 If more than 4 Gigabytes is used then answer "64GB" here. This
1406 selection turns Intel PAE (Physical Address Extension) mode on.
1407 PAE implements 3-level paging on IA32 processors. PAE is fully
1408 supported by Linux, PAE mode is implemented on all recent Intel
1409 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1410 then the kernel will not boot on CPUs that don't support PAE!
1411
1412 The actual amount of total physical memory will either be
1413 auto detected or can be forced by using a kernel command line option
1414 such as "mem=256M". (Try "man bootparam" or see the documentation of
1415 your boot loader (lilo or loadlin) about how to pass options to the
1416 kernel at boot time.)
1417
1418 If unsure, say "off".
1419
1420config HIGHMEM4G
1421 bool "4GB"
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 between 1 and 4
1424 gigabytes of physical RAM.
1425
1426config HIGHMEM64G
1427 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001428 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001429 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001430 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001431 Select this if you have a 32-bit processor and more than 4
1432 gigabytes of physical RAM.
1433
1434endchoice
1435
1436choice
David Rientjes6a108a12011-01-20 14:44:16 -08001437 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001438 default VMSPLIT_3G
1439 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001440 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001441 Select the desired split between kernel and user memory.
1442
1443 If the address range available to the kernel is less than the
1444 physical memory installed, the remaining memory will be available
1445 as "high memory". Accessing high memory is a little more costly
1446 than low memory, as it needs to be mapped into the kernel first.
1447 Note that increasing the kernel address space limits the range
1448 available to user programs, making the address space there
1449 tighter. Selecting anything other than the default 3G/1G split
1450 will also likely make your kernel incompatible with binary-only
1451 kernel modules.
1452
1453 If you are not absolutely sure what you are doing, leave this
1454 option alone!
1455
1456 config VMSPLIT_3G
1457 bool "3G/1G user/kernel split"
1458 config VMSPLIT_3G_OPT
1459 depends on !X86_PAE
1460 bool "3G/1G user/kernel split (for full 1G low memory)"
1461 config VMSPLIT_2G
1462 bool "2G/2G user/kernel split"
1463 config VMSPLIT_2G_OPT
1464 depends on !X86_PAE
1465 bool "2G/2G user/kernel split (for full 2G low memory)"
1466 config VMSPLIT_1G
1467 bool "1G/3G user/kernel split"
1468endchoice
1469
1470config PAGE_OFFSET
1471 hex
1472 default 0xB0000000 if VMSPLIT_3G_OPT
1473 default 0x80000000 if VMSPLIT_2G
1474 default 0x78000000 if VMSPLIT_2G_OPT
1475 default 0x40000000 if VMSPLIT_1G
1476 default 0xC0000000
1477 depends on X86_32
1478
1479config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001480 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001481 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001482
1483config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001484 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001485 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001486 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001487 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001488 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001489 PAE is required for NX support, and furthermore enables
1490 larger swapspace support for non-overcommit purposes. It
1491 has the cost of more pagetable lookup overhead, and also
1492 consumes more pagetable space per process.
1493
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001494config X86_5LEVEL
1495 bool "Enable 5-level page tables support"
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001496 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001497 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001498 depends on X86_64
1499 ---help---
1500 5-level paging enables access to larger address space:
1501 upto 128 PiB of virtual address space and 4 PiB of
1502 physical address space.
1503
1504 It will be supported by future Intel CPUs.
1505
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001506 A kernel with the option enabled can be booted on machines that
1507 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001508
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001509 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001510 information.
1511
1512 Say N if unsure.
1513
Ingo Molnar10971ab2015-03-05 08:18:23 +01001514config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001515 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001516 depends on X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001517 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001518 Certain kernel features effectively disable kernel
1519 linear 1 GB mappings (even if the CPU otherwise
1520 supports them), so don't confuse the user by printing
1521 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001522
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001523config X86_CPA_STATISTICS
1524 bool "Enable statistic for Change Page Attribute"
1525 depends on DEBUG_FS
1526 ---help---
1527 Expose statistics about the Change Page Attribute mechanims, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001528 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001529 page mappings when mapping protections are changed.
1530
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001531config AMD_MEM_ENCRYPT
1532 bool "AMD Secure Memory Encryption (SME) support"
1533 depends on X86_64 && CPU_SUP_AMD
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001534 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001535 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001536 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001537 ---help---
1538 Say yes to enable support for the encryption of system memory.
1539 This requires an AMD processor that supports Secure Memory
1540 Encryption (SME).
1541
1542config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1543 bool "Activate AMD Secure Memory Encryption (SME) by default"
1544 default y
1545 depends on AMD_MEM_ENCRYPT
1546 ---help---
1547 Say yes to have system memory encrypted by default if running on
1548 an AMD processor that supports Secure Memory Encryption (SME).
1549
1550 If set to Y, then the encryption of system memory can be
1551 deactivated with the mem_encrypt=off command line option.
1552
1553 If set to N, then the encryption of system memory can be
1554 activated with the mem_encrypt=on command line option.
1555
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001556# Common NUMA Features
1557config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001558 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001559 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001560 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1561 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001562 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001563 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001564
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001565 The kernel will try to allocate memory used by a CPU on the
1566 local memory controller of the CPU and add some more
1567 NUMA awareness to the kernel.
1568
Ingo Molnarc280ea52008-11-08 13:29:45 +01001569 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001570 (or later), AMD Opteron, or EM64T NUMA.
1571
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001572 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001573 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001574
1575 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001576
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001577config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001578 def_bool y
1579 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001580 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001581 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001582 Enable AMD NUMA node topology detection. You should say Y here if
1583 you have a multi processor AMD system. This uses an old method to
1584 read the NUMA configuration directly from the builtin Northbridge
1585 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1586 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001587
1588config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001589 def_bool y
1590 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001591 depends on X86_64 && NUMA && ACPI && PCI
1592 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001593 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001594 Enable ACPI SRAT based node topology detection.
1595
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001596# Some NUMA nodes have memory ranges that span
1597# other nodes. Even though a pfn is valid and
1598# between a node's start and end pfns, it may not
1599# reside on that node. See memmap_init_zone()
1600# for details.
1601config NODES_SPAN_OTHER_NODES
1602 def_bool y
1603 depends on X86_64_ACPI_NUMA
1604
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001605config NUMA_EMU
1606 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001607 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001608 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001609 Enable NUMA emulation. A flat machine will be split
1610 into virtual nodes when booted with "numa=fake=N", where N is the
1611 number of nodes. This is only useful for debugging.
1612
1613config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001614 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001615 range 1 10
1616 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001617 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001618 default "3"
1619 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001620 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001621 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001622 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001623
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001624config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001625 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001626 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001627
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001628config ARCH_FLATMEM_ENABLE
1629 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001630 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001631
1632config ARCH_DISCONTIGMEM_ENABLE
Mike Rapoport27921072019-04-24 16:24:12 +03001633 def_bool n
Christoph Lameterb2632952008-01-30 13:30:47 +01001634 depends on NUMA && X86_32
Mike Rapoport27921072019-04-24 16:24:12 +03001635 depends on BROKEN
Christoph Lameterb2632952008-01-30 13:30:47 +01001636
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001637config ARCH_SPARSEMEM_ENABLE
1638 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001639 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001640 select SPARSEMEM_STATIC if X86_32
1641 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1642
Tejun Heo3b166512011-04-01 11:15:12 +02001643config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001644 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001645
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001646config ARCH_SELECT_MEMORY_MODEL
1647 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001648 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001649
1650config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001651 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001652 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001653 help
1654 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001655 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001656 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001657
Tejun Heo3b166512011-04-01 11:15:12 +02001658config ARCH_PROC_KCORE_TEXT
1659 def_bool y
1660 depends on X86_64 && PROC_KCORE
1661
Avi Kivitya29815a2010-01-10 16:28:09 +02001662config ILLEGAL_POINTER_VALUE
1663 hex
1664 default 0 if X86_32
1665 default 0xdead000000000000 if X86_64
1666
Dan Williams7a678322015-08-19 00:34:34 -04001667config X86_PMEM_LEGACY_DEVICE
1668 bool
1669
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001670config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001671 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001672 depends on PHYS_ADDR_T_64BIT
1673 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001674 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001675 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001676 help
1677 Treat memory marked using the non-standard e820 type of 12 as used
1678 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1679 The kernel will offer these regions to the 'pmem' driver so
1680 they can be used for persistent storage.
1681
1682 Say Y if unsure.
1683
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001684config HIGHPTE
1685 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001686 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001687 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001688 The VM uses one page table entry for each page of physical memory.
1689 For systems with a lot of RAM, this can be wasteful of precious
1690 low memory. Setting this option will put user-space page table
1691 entries in high memory.
1692
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001693config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001694 bool "Check for low memory corruption"
1695 ---help---
1696 Periodically check for memory corruption in low memory, which
1697 is suspected to be caused by BIOS. Even when enabled in the
1698 configuration, it is disabled at runtime. Enable it by
1699 setting "memory_corruption_check=1" on the kernel command
1700 line. By default it scans the low 64k of memory every 60
1701 seconds; see the memory_corruption_check_size and
1702 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001703 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001704
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001705 When enabled with the default parameters, this option has
1706 almost no overhead, as it reserves a relatively small amount
1707 of memory and scans it infrequently. It both detects corruption
1708 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001709
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001710 It is, however, intended as a diagnostic tool; if repeatable
1711 BIOS-originated corruption always affects the same memory,
1712 you can use memmap= to prevent the kernel from using that
1713 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001714
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001715config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001716 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001717 depends on X86_CHECK_BIOS_CORRUPTION
1718 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001719 ---help---
1720 Set whether the default state of memory_corruption_check is
1721 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001722
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001723config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001724 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1725 default 64
1726 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001727 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001728 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001729
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001730 The first page contains BIOS data structures that the kernel
1731 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001732
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001733 By default we reserve the first 64K of physical RAM, as a
1734 number of BIOSes are known to corrupt that memory range
1735 during events such as suspend/resume or monitor cable
1736 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001737
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001738 You can set this to 4 if you are absolutely sure that you
1739 trust the BIOS to get all its memory reservations and usages
1740 right. If you know your BIOS have problems beyond the
1741 default 64K area, you can set this to 640 to avoid using the
1742 entire low memory range.
1743
1744 If you have doubts about the BIOS (e.g. suspend/resume does
1745 not work or there's kernel crashes after certain hardware
1746 hotplug events) then you might want to enable
1747 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1748 typical corruption patterns.
1749
1750 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001751
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001752config MATH_EMULATION
1753 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001754 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001755 prompt "Math emulation" if X86_32
1756 ---help---
1757 Linux can emulate a math coprocessor (used for floating point
1758 operations) if you don't have one. 486DX and Pentium processors have
1759 a math coprocessor built in, 486SX and 386 do not, unless you added
1760 a 487DX or 387, respectively. (The messages during boot time can
1761 give you some hints here ["man dmesg"].) Everyone needs either a
1762 coprocessor or this emulation.
1763
1764 If you don't have a math coprocessor, you need to say Y here; if you
1765 say Y here even though you have a coprocessor, the coprocessor will
1766 be used nevertheless. (This behavior can be changed with the kernel
1767 command line option "no387", which comes handy if your coprocessor
1768 is broken. Try "man bootparam" or see the documentation of your boot
1769 loader (lilo or loadlin) about how to pass options to the kernel at
1770 boot time.) This means that it is a good idea to say Y here if you
1771 intend to use this kernel on different machines.
1772
1773 More information about the internals of the Linux math coprocessor
1774 emulation can be found in <file:arch/x86/math-emu/README>.
1775
1776 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1777 kernel, it won't hurt.
1778
1779config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001780 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001781 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001782 ---help---
1783 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1784 the Memory Type Range Registers (MTRRs) may be used to control
1785 processor access to memory ranges. This is most useful if you have
1786 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1787 allows bus write transfers to be combined into a larger transfer
1788 before bursting over the PCI/AGP bus. This can increase performance
1789 of image write operations 2.5 times or more. Saying Y here creates a
1790 /proc/mtrr file which may be used to manipulate your processor's
1791 MTRRs. Typically the X server should use this.
1792
1793 This code has a reasonably generic interface so that similar
1794 control registers on other processors can be easily supported
1795 as well:
1796
1797 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1798 Registers (ARRs) which provide a similar functionality to MTRRs. For
1799 these, the ARRs are used to emulate the MTRRs.
1800 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1801 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1802 write-combining. All of these processors are supported by this code
1803 and it makes sense to say Y here if you have one of them.
1804
1805 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1806 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1807 can lead to all sorts of problems, so it's good to say Y here.
1808
1809 You can safely say Y even if your machine doesn't have MTRRs, you'll
1810 just add about 9 KB to your kernel.
1811
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001812 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001813
Yinghai Lu95ffa242008-04-29 03:52:33 -07001814config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001815 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001816 prompt "MTRR cleanup support"
1817 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001818 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001819 Convert MTRR layout from continuous to discrete, so X drivers can
1820 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001821
Thomas Gleixneraba37282008-07-15 14:48:48 +02001822 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001823 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001824 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001825
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001826 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001827
1828config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001829 int "MTRR cleanup enable value (0-1)"
1830 range 0 1
1831 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001832 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001833 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001834 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001835
Yinghai Lu12031a62008-05-02 02:40:22 -07001836config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1837 int "MTRR cleanup spare reg num (0-7)"
1838 range 0 7
1839 default "1"
1840 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001841 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001842 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001843 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001844
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001845config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001846 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001847 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001848 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001849 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001850 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001851
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001852 PATs are the modern equivalents of MTRRs and are much more
1853 flexible than MTRRs.
1854
1855 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001856 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001857
1858 If unsure, say Y.
1859
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001860config ARCH_USES_PG_UNCACHED
1861 def_bool y
1862 depends on X86_PAT
1863
H. Peter Anvin628c6242011-07-31 13:59:29 -07001864config ARCH_RANDOM
1865 def_bool y
1866 prompt "x86 architectural random number generator" if EXPERT
1867 ---help---
1868 Enable the x86 architectural RDRAND instruction
1869 (Intel Bull Mountain technology) to generate random numbers.
1870 If supported, this is a high bandwidth, cryptographically
1871 secure hardware random number generator.
1872
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001873config X86_SMAP
1874 def_bool y
1875 prompt "Supervisor Mode Access Prevention" if EXPERT
1876 ---help---
1877 Supervisor Mode Access Prevention (SMAP) is a security
1878 feature in newer Intel processors. There is a small
1879 performance cost if this enabled and turned on; there is
1880 also a small increase in the kernel size if this is enabled.
1881
1882 If unsure, say Y.
1883
Ricardo Neriaa35f892017-11-05 18:27:54 -08001884config X86_INTEL_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001885 def_bool y
Ricardo Neriaa35f892017-11-05 18:27:54 -08001886 depends on CPU_SUP_INTEL
1887 prompt "Intel User Mode Instruction Prevention" if EXPERT
1888 ---help---
1889 The User Mode Instruction Prevention (UMIP) is a security
1890 feature in newer Intel processors. If enabled, a general
Ricardo Neri796ebc82017-11-13 22:29:42 -08001891 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1892 or STR instructions are executed in user mode. These instructions
1893 unnecessarily expose information about the hardware state.
1894
1895 The vast majority of applications do not use these instructions.
1896 For the very few that do, software emulation is provided in
1897 specific cases in protected and virtual-8086 modes. Emulated
1898 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001899
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001900config X86_INTEL_MPX
1901 prompt "Intel MPX (Memory Protection Extensions)"
1902 def_bool n
Rik van Rieldf3735c2017-09-06 16:25:11 -07001903 # Note: only available in 64-bit mode due to VMA flags shortage
1904 depends on CPU_SUP_INTEL && X86_64
1905 select ARCH_USES_HIGH_VMA_FLAGS
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001906 ---help---
1907 MPX provides hardware features that can be used in
1908 conjunction with compiler-instrumented code to check
1909 memory references. It is designed to detect buffer
1910 overflow or underflow bugs.
1911
1912 This option enables running applications which are
1913 instrumented or otherwise use MPX. It does not use MPX
1914 itself inside the kernel or to protect the kernel
1915 against bad memory references.
1916
1917 Enabling this option will make the kernel larger:
1918 ~8k of kernel text and 36 bytes of data on a 64-bit
1919 defconfig. It adds a long to the 'mm_struct' which
1920 will increase the kernel memory overhead of each
1921 process and adds some branches to paths used during
1922 exec() and munmap().
1923
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001924 For details, see Documentation/x86/intel_mpx.rst
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001925
1926 If unsure, say N.
1927
Dave Hansen35e97792016-02-12 13:02:00 -08001928config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001929 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001930 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001931 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001932 depends on CPU_SUP_INTEL && X86_64
Ingo Molnar52c8e602016-11-15 10:15:03 +01001933 select ARCH_USES_HIGH_VMA_FLAGS
1934 select ARCH_HAS_PKEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001935 ---help---
1936 Memory Protection Keys provides a mechanism for enforcing
1937 page-based protections, but without requiring modification of the
1938 page tables when an application changes protection domains.
1939
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001940 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001941
1942 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001943
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001944config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001945 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001946 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001947 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001948 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001949 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001950 This enables the kernel to use EFI runtime services that are
1951 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001952
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001953 This option is only useful on systems that have EFI firmware.
1954 In addition, you should use the latest ELILO loader available
1955 at <http://elilo.sourceforge.net> in order to take advantage
1956 of EFI runtime services. However, even with this option, the
1957 resultant kernel should continue to boot on existing non-EFI
1958 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001959
Matt Fleming291f3632011-12-12 21:27:52 +00001960config EFI_STUB
1961 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001962 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001963 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001964 ---help---
1965 This kernel feature allows a bzImage to be loaded directly
1966 by EFI firmware without the use of a bootloader.
1967
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001968 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001969
Matt Fleming7d453ee2014-01-10 18:52:06 +00001970config EFI_MIXED
1971 bool "EFI mixed-mode support"
1972 depends on EFI_STUB && X86_64
1973 ---help---
1974 Enabling this feature allows a 64-bit kernel to be booted
1975 on a 32-bit firmware, provided that your CPU supports 64-bit
1976 mode.
1977
1978 Note that it is not possible to boot a mixed-mode enabled
1979 kernel via the EFI boot stub - a bootloader that supports
1980 the EFI handover protocol must be used.
1981
1982 If unsure, say N.
1983
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001984config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001985 def_bool y
1986 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001987 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001988 This kernel feature is useful for number crunching applications
1989 that may need to compute untrusted bytecode during their
1990 execution. By using pipes or other transports made available to
1991 the process as file descriptors supporting the read/write
1992 syscalls, it's possible to isolate those applications in
1993 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001994 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001995 and the task is only allowed to execute a few safe syscalls
1996 defined by each seccomp mode.
1997
1998 If unsure, say Y. Only embedded should say N here.
1999
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09002000source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002001
2002config KEXEC
2003 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07002004 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002005 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002006 kexec is a system call that implements the ability to shutdown your
2007 current kernel, and to start another kernel. It is like a reboot
2008 but it is independent of the system firmware. And like a reboot
2009 you can start any kernel with it, not just Linux.
2010
2011 The name comes from the similarity to the exec system call.
2012
2013 It is an ongoing process to be certain the hardware in a machine
2014 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002015 initially work for you. As of this writing the exact hardware
2016 interface is strongly in flux, so no good recommendation can be
2017 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002018
Vivek Goyal74ca3172014-08-29 15:18:46 -07002019config KEXEC_FILE
2020 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002021 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002022 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002023 depends on X86_64
2024 depends on CRYPTO=y
2025 depends on CRYPTO_SHA256=y
2026 ---help---
2027 This is new version of kexec system call. This system call is
2028 file based and takes file descriptors as system call argument
2029 for kernel and initramfs as opposed to list of segments as
2030 accepted by previous system call.
2031
AKASHI Takahirob799a092018-04-13 15:35:45 -07002032config ARCH_HAS_KEXEC_PURGATORY
2033 def_bool KEXEC_FILE
2034
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002035config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002036 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002037 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002038 ---help---
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002039
2040 This option makes the kexec_file_load() syscall check for a valid
2041 signature of the kernel image. The image can still be loaded without
2042 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2043 there's a signature that we can check, then it must be valid.
2044
2045 In addition to this option, you need to enable signature
2046 verification for the corresponding kernel image type being
2047 loaded in order for this to work.
2048
2049config KEXEC_SIG_FORCE
2050 bool "Require a valid signature in kexec_file_load() syscall"
2051 depends on KEXEC_SIG
2052 ---help---
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002053 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002054 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002055
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002056config KEXEC_BZIMAGE_VERIFY_SIG
2057 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002058 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002059 depends on SIGNED_PE_FILE_VERIFICATION
2060 select SYSTEM_TRUSTED_KEYRING
2061 ---help---
2062 Enable bzImage signature verification support.
2063
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002064config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002065 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002066 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002067 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002068 Generate crash dump after being started by kexec.
2069 This should be normally only set in special crash dump kernels
2070 which are loaded in the main kernel with kexec-tools into
2071 a specially reserved region and then later executed after
2072 a crash by kdump/kexec. The crash dump kernel must be compiled
2073 to a memory address not used by the main kernel or BIOS using
2074 PHYSICAL_START, or it must be built as a relocatable image
2075 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002076 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002077
Huang Ying3ab83522008-07-25 19:45:07 -07002078config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002079 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002080 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002081 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07002082 Jump between original kernel and kexeced kernel and invoke
2083 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002084
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002085config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002086 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002087 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002088 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002089 This gives the physical address where the kernel is loaded.
2090
2091 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2092 bzImage will decompress itself to above physical address and
2093 run from there. Otherwise, bzImage will run from the address where
2094 it has been loaded by the boot loader and will ignore above physical
2095 address.
2096
2097 In normal kdump cases one does not have to set/change this option
2098 as now bzImage can be compiled as a completely relocatable image
2099 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2100 address. This option is mainly useful for the folks who don't want
2101 to use a bzImage for capturing the crash dump and want to use a
2102 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2103 to be specifically compiled to run from a specific memory area
2104 (normally a reserved region) and this option comes handy.
2105
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002106 So if you are using bzImage for capturing the crash dump,
2107 leave the value here unchanged to 0x1000000 and set
2108 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2109 for capturing the crash dump change this value to start of
2110 the reserved region. In other words, it can be set based on
2111 the "X" value as specified in the "crashkernel=YM@XM"
2112 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002113 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002114 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002115
2116 Usage of bzImage for capturing the crash dump is recommended as
2117 one does not have to build two kernels. Same kernel can be used
2118 as production kernel and capture kernel. Above option should have
2119 gone away after relocatable bzImage support is introduced. But it
2120 is present because there are users out there who continue to use
2121 vmlinux for dump capture. This option should go away down the
2122 line.
2123
2124 Don't change this unless you know what you are doing.
2125
2126config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002127 bool "Build a relocatable kernel"
2128 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002129 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002130 This builds a kernel image that retains relocation information
2131 so it can be loaded someplace besides the default 1MB.
2132 The relocations tend to make the kernel binary about 10% larger,
2133 but are discarded at runtime.
2134
2135 One use is for the kexec on panic case where the recovery kernel
2136 must live at a different physical address than the primary
2137 kernel.
2138
2139 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2140 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002141 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002142
Kees Cook8ab38202013-10-10 17:18:14 -07002143config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002144 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002145 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002146 default y
Kees Cook8ab38202013-10-10 17:18:14 -07002147 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07002148 In support of Kernel Address Space Layout Randomization (KASLR),
2149 this randomizes the physical address at which the kernel image
2150 is decompressed and the virtual address where the kernel
2151 image is mapped, as a security feature that deters exploit
2152 attempts relying on knowledge of the location of kernel
2153 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002154
Kees Cooked9f0072016-05-25 15:45:33 -07002155 On 64-bit, the kernel physical and virtual addresses are
2156 randomized separately. The physical address will be anywhere
2157 between 16MB and the top of physical memory (up to 64TB). The
2158 virtual address will be randomized from 16MB up to 1GB (9 bits
2159 of entropy). Note that this also reduces the memory space
2160 available to kernel modules from 1.5GB to 1GB.
2161
2162 On 32-bit, the kernel physical and virtual addresses are
2163 randomized together. They will be randomized from 16MB up to
2164 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002165
Baoquan Hee8581e32016-04-20 13:55:43 -07002166 Entropy is generated using the RDRAND instruction if it is
2167 supported. If RDTSC is supported, its value is mixed into
2168 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002169 supported, then entropy is read from the i8254 timer. The
2170 usable entropy is limited by the kernel being built using
2171 2GB addressing, and that PHYSICAL_ALIGN must be at a
2172 minimum of 2MB. As a result, only 10 bits of entropy are
2173 theoretically possible, but the implementations are further
2174 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002175
Ingo Molnar6807c842017-04-18 11:08:12 +02002176 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002177
2178# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002179config X86_NEED_RELOCS
2180 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002181 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002182
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002183config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002184 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002185 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002186 range 0x2000 0x1000000 if X86_32
2187 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002188 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002189 This value puts the alignment restrictions on physical address
2190 where kernel is loaded and run from. Kernel is compiled for an
2191 address which meets above alignment restriction.
2192
2193 If bootloader loads the kernel at a non-aligned address and
2194 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2195 address aligned to above value and run from there.
2196
2197 If bootloader loads the kernel at a non-aligned address and
2198 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2199 load address and decompress itself to the address it has been
2200 compiled for and run from there. The address for which kernel is
2201 compiled already meets above alignment restrictions. Hence the
2202 end result is that kernel runs from a physical address meeting
2203 above alignment restrictions.
2204
Kees Cooka0215062013-07-08 09:15:17 -07002205 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2206 this value must be a multiple of 0x200000.
2207
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002208 Don't change this unless you know what you are doing.
2209
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002210config DYNAMIC_MEMORY_LAYOUT
2211 bool
2212 ---help---
2213 This option makes base addresses of vmalloc and vmemmap as well as
2214 __PAGE_OFFSET movable during boot.
2215
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002216config RANDOMIZE_MEMORY
2217 bool "Randomize the kernel memory sections"
2218 depends on X86_64
2219 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002220 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002221 default RANDOMIZE_BASE
2222 ---help---
2223 Randomizes the base virtual address of kernel memory sections
2224 (physical memory mapping, vmalloc & vmemmap). This security feature
2225 makes exploits relying on predictable memory locations less reliable.
2226
2227 The order of allocations remains unchanged. Entropy is generated in
2228 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2229 configuration have in average 30,000 different possible virtual
2230 addresses for each memory section.
2231
Ingo Molnar6807c842017-04-18 11:08:12 +02002232 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002233
Thomas Garnier90397a42016-06-21 17:47:06 -07002234config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2235 hex "Physical memory mapping padding" if EXPERT
2236 depends on RANDOMIZE_MEMORY
2237 default "0xa" if MEMORY_HOTPLUG
2238 default "0x0"
2239 range 0x1 0x40 if MEMORY_HOTPLUG
2240 range 0x0 0x40
2241 ---help---
2242 Define the padding in terabytes added to the existing physical
2243 memory size during kernel memory randomization. It is useful
2244 for memory hotplug support but reduces the entropy available for
2245 address randomization.
2246
2247 If unsure, leave at the default value.
2248
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002249config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002250 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002251 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002252
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002253config BOOTPARAM_HOTPLUG_CPU0
2254 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002255 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002256 ---help---
2257 Set whether default state of cpu0_hotpluggable is on or off.
2258
2259 Say Y here to enable CPU0 hotplug by default. If this switch
2260 is turned on, there is no need to give cpu0_hotplug kernel
2261 parameter and the CPU0 hotplug feature is enabled by default.
2262
2263 Please note: there are two known CPU0 dependencies if you want
2264 to enable the CPU0 hotplug feature either by this switch or by
2265 cpu0_hotplug kernel parameter.
2266
2267 First, resume from hibernate or suspend always starts from CPU0.
2268 So hibernate and suspend are prevented if CPU0 is offline.
2269
2270 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2271 offline if any interrupt can not migrate out of CPU0. There may
2272 be other CPU0 dependencies.
2273
2274 Please make sure the dependencies are under your control before
2275 you enable this feature.
2276
2277 Say N if you don't want to enable CPU0 hotplug feature by default.
2278 You still can enable the CPU0 hotplug feature at boot by kernel
2279 parameter cpu0_hotplug.
2280
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002281config DEBUG_HOTPLUG_CPU0
2282 def_bool n
2283 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002284 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002285 ---help---
2286 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2287 soon as possible and boots up userspace with CPU0 offlined. User
2288 can online CPU0 back after boot time.
2289
2290 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2291 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2292 compilation or giving cpu0_hotplug kernel parameter at boot.
2293
2294 If unsure, say N.
2295
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002296config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002297 def_bool n
2298 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002299 depends on COMPAT_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002300 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002301 Certain buggy versions of glibc will crash if they are
2302 presented with a 32-bit vDSO that is not mapped at the address
2303 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002304
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002305 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2306 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2307 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2308 the only released version with the bug, but OpenSUSE 9
2309 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002310
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002311 The symptom of the bug is that everything crashes on startup, saying:
2312 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2313
2314 Saying Y here changes the default value of the vdso32 boot
2315 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2316 This works around the glibc bug but hurts performance.
2317
2318 If unsure, say N: if you are compiling your own kernel, you
2319 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002320
Kees Cook3dc33bd2015-08-12 17:55:19 -07002321choice
2322 prompt "vsyscall table for legacy applications"
2323 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002324 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002325 help
2326 Legacy user code that does not know how to find the vDSO expects
2327 to be able to issue three syscalls by calling fixed addresses in
2328 kernel space. Since this location is not randomized with ASLR,
2329 it can be used to assist security vulnerability exploitation.
2330
2331 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002332 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002333
2334 On a system with recent enough glibc (2.14 or newer) and no
2335 static binaries, you can say None without a performance penalty
2336 to improve security.
2337
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002338 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002339
Kees Cook3dc33bd2015-08-12 17:55:19 -07002340 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002341 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002342 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002343 The kernel traps and emulates calls into the fixed vsyscall
2344 address mapping. This makes the mapping non-executable, but
2345 it still contains readable known contents, which could be
2346 used in certain rare security vulnerability exploits. This
2347 configuration is recommended when using legacy userspace
2348 that still uses vsyscalls along with legacy binary
2349 instrumentation tools that require code to be readable.
2350
2351 An example of this type of legacy userspace is running
2352 Pin on an old binary that still uses vsyscalls.
2353
2354 config LEGACY_VSYSCALL_XONLY
2355 bool "Emulate execution only"
2356 help
2357 The kernel traps and emulates calls into the fixed vsyscall
2358 address mapping and does not allow reads. This
2359 configuration is recommended when userspace might use the
2360 legacy vsyscall area but support for legacy binary
2361 instrumentation of legacy code is not needed. It mitigates
2362 certain uses of the vsyscall area as an ASLR-bypassing
2363 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002364
2365 config LEGACY_VSYSCALL_NONE
2366 bool "None"
2367 help
2368 There will be no vsyscall mapping at all. This will
2369 eliminate any risk of ASLR bypass due to the vsyscall
2370 fixed address mapping. Attempts to use the vsyscalls
2371 will be reported to dmesg, so that either old or
2372 malicious userspace programs can be identified.
2373
2374endchoice
2375
Tim Bird516cbf32008-08-12 12:52:36 -07002376config CMDLINE_BOOL
2377 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002378 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002379 Allow for specifying boot arguments to the kernel at
2380 build time. On some systems (e.g. embedded ones), it is
2381 necessary or convenient to provide some or all of the
2382 kernel boot arguments with the kernel itself (that is,
2383 to not rely on the boot loader to provide them.)
2384
2385 To compile command line arguments into the kernel,
2386 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002387 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002388
2389 Systems with fully functional boot loaders (i.e. non-embedded)
2390 should leave this option set to 'N'.
2391
2392config CMDLINE
2393 string "Built-in kernel command string"
2394 depends on CMDLINE_BOOL
2395 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002396 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002397 Enter arguments here that should be compiled into the kernel
2398 image and used at boot time. If the boot loader provides a
2399 command line at boot time, it is appended to this string to
2400 form the full kernel command line, when the system boots.
2401
2402 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2403 change this behavior.
2404
2405 In most cases, the command line (whether built-in or provided
2406 by the boot loader) should specify the device for the root
2407 file system.
2408
2409config CMDLINE_OVERRIDE
2410 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002411 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002412 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002413 Set this option to 'Y' to have the kernel ignore the boot loader
2414 command line, and use ONLY the built-in command line.
2415
2416 This is used to work around broken boot loaders. This should
2417 be set to 'N' under normal conditions.
2418
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002419config MODIFY_LDT_SYSCALL
2420 bool "Enable the LDT (local descriptor table)" if EXPERT
2421 default y
2422 ---help---
2423 Linux can allow user programs to install a per-process x86
2424 Local Descriptor Table (LDT) using the modify_ldt(2) system
2425 call. This is required to run 16-bit or segmented code such as
2426 DOSEMU or some Wine programs. It is also used by some very old
2427 threading libraries.
2428
2429 Enabling this feature adds a small amount of overhead to
2430 context switches and increases the low-level kernel attack
2431 surface. Disabling it removes the modify_ldt(2) system call.
2432
2433 Saying 'N' here may make sense for embedded or server kernels.
2434
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002435source "kernel/livepatch/Kconfig"
2436
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002437endmenu
2438
Michal Hocko3072e412017-09-08 16:11:39 -07002439config ARCH_HAS_ADD_PAGES
2440 def_bool y
2441 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2442
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002443config ARCH_ENABLE_MEMORY_HOTPLUG
2444 def_bool y
2445 depends on X86_64 || (X86_32 && HIGHMEM)
2446
Gary Hade35551052008-10-31 10:52:03 -07002447config ARCH_ENABLE_MEMORY_HOTREMOVE
2448 def_bool y
2449 depends on MEMORY_HOTPLUG
2450
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002451config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002452 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002453 depends on NUMA
2454
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002455config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2456 def_bool y
2457 depends on X86_64 || X86_PAE
2458
Naoya Horiguchic177c812014-06-04 16:05:35 -07002459config ARCH_ENABLE_HUGEPAGE_MIGRATION
2460 def_bool y
2461 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2462
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002463config ARCH_ENABLE_THP_MIGRATION
2464 def_bool y
2465 depends on X86_64 && TRANSPARENT_HUGEPAGE
2466
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002467menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002468
2469config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002470 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002471 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002472
2473source "kernel/power/Kconfig"
2474
2475source "drivers/acpi/Kconfig"
2476
Feng Tangefafc8b2009-08-14 15:23:29 -04002477source "drivers/sfi/Kconfig"
2478
Andi Kleena6b68072008-01-30 13:32:49 +01002479config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002480 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002481 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002482
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002483menuconfig APM
2484 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002485 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002486 ---help---
2487 APM is a BIOS specification for saving power using several different
2488 techniques. This is mostly useful for battery powered laptops with
2489 APM compliant BIOSes. If you say Y here, the system time will be
2490 reset after a RESUME operation, the /proc/apm device will provide
2491 battery status information, and user-space programs will receive
2492 notification of APM "events" (e.g. battery status change).
2493
2494 If you select "Y" here, you can disable actual use of the APM
2495 BIOS by passing the "apm=off" option to the kernel at boot time.
2496
2497 Note that the APM support is almost completely disabled for
2498 machines with more than one CPU.
2499
2500 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002501 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002502 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002503 <http://www.tldp.org/docs.html#howto>.
2504
2505 This driver does not spin down disk drives (see the hdparm(8)
2506 manpage ("man 8 hdparm") for that), and it doesn't turn off
2507 VESA-compliant "green" monitors.
2508
2509 This driver does not support the TI 4000M TravelMate and the ACER
2510 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2511 desktop machines also don't have compliant BIOSes, and this driver
2512 may cause those machines to panic during the boot phase.
2513
2514 Generally, if you don't have a battery in your machine, there isn't
2515 much point in using this driver and you should say N. If you get
2516 random kernel OOPSes or reboots that don't seem to be related to
2517 anything, try disabling/enabling this option (or disabling/enabling
2518 APM in your BIOS).
2519
2520 Some other things you should try when experiencing seemingly random,
2521 "weird" problems:
2522
2523 1) make sure that you have enough swap space and that it is
2524 enabled.
2525 2) pass the "no-hlt" option to the kernel
2526 3) switch on floating point emulation in the kernel and pass
2527 the "no387" option to the kernel
2528 4) pass the "floppy=nodma" option to the kernel
2529 5) pass the "mem=4M" option to the kernel (thereby disabling
2530 all but the first 4 MB of RAM)
2531 6) make sure that the CPU is not over clocked.
2532 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2533 8) disable the cache from your BIOS settings
2534 9) install a fan for the video card or exchange video RAM
2535 10) install a better fan for the CPU
2536 11) exchange RAM chips
2537 12) exchange the motherboard.
2538
2539 To compile this driver as a module, choose M here: the
2540 module will be called apm.
2541
2542if APM
2543
2544config APM_IGNORE_USER_SUSPEND
2545 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002546 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002547 This option will ignore USER SUSPEND requests. On machines with a
2548 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2549 series notebooks, it is necessary to say Y because of a BIOS bug.
2550
2551config APM_DO_ENABLE
2552 bool "Enable PM at boot time"
2553 ---help---
2554 Enable APM features at boot time. From page 36 of the APM BIOS
2555 specification: "When disabled, the APM BIOS does not automatically
2556 power manage devices, enter the Standby State, enter the Suspend
2557 State, or take power saving steps in response to CPU Idle calls."
2558 This driver will make CPU Idle calls when Linux is idle (unless this
2559 feature is turned off -- see "Do CPU IDLE calls", below). This
2560 should always save battery power, but more complicated APM features
2561 will be dependent on your BIOS implementation. You may need to turn
2562 this option off if your computer hangs at boot time when using APM
2563 support, or if it beeps continuously instead of suspending. Turn
2564 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2565 T400CDT. This is off by default since most machines do fine without
2566 this feature.
2567
2568config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002569 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002570 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002571 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002572 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2573 On some machines, this can activate improved power savings, such as
2574 a slowed CPU clock rate, when the machine is idle. These idle calls
2575 are made after the idle loop has run for some length of time (e.g.,
2576 333 mS). On some machines, this will cause a hang at boot time or
2577 whenever the CPU becomes idle. (On machines with more than one CPU,
2578 this option does nothing.)
2579
2580config APM_DISPLAY_BLANK
2581 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002582 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002583 Enable console blanking using the APM. Some laptops can use this to
2584 turn off the LCD backlight when the screen blanker of the Linux
2585 virtual console blanks the screen. Note that this is only used by
2586 the virtual console screen blanker, and won't turn off the backlight
2587 when using the X Window system. This also doesn't have anything to
2588 do with your VESA-compliant power-saving monitor. Further, this
2589 option doesn't work for all laptops -- it might not turn off your
2590 backlight at all, or it might print a lot of errors to the console,
2591 especially if you are using gpm.
2592
2593config APM_ALLOW_INTS
2594 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002595 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002596 Normally we disable external interrupts while we are making calls to
2597 the APM BIOS as a measure to lessen the effects of a badly behaving
2598 BIOS implementation. The BIOS should reenable interrupts if it
2599 needs to. Unfortunately, some BIOSes do not -- especially those in
2600 many of the newer IBM Thinkpads. If you experience hangs when you
2601 suspend, try setting this to Y. Otherwise, say N.
2602
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002603endif # APM
2604
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002605source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606
2607source "drivers/cpuidle/Kconfig"
2608
Andy Henroid27471fd2008-10-09 11:45:22 -07002609source "drivers/idle/Kconfig"
2610
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002611endmenu
2612
2613
2614menu "Bus options (PCI etc.)"
2615
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002616choice
2617 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002618 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002619 default PCI_GOANY
2620 ---help---
2621 On PCI systems, the BIOS can be used to detect the PCI devices and
2622 determine their configuration. However, some old PCI motherboards
2623 have BIOS bugs and may crash if this is done. Also, some embedded
2624 PCI-based systems don't have any BIOS at all. Linux can also try to
2625 detect the PCI hardware directly without using the BIOS.
2626
2627 With this option, you can specify how Linux should detect the
2628 PCI devices. If you choose "BIOS", the BIOS will be used,
2629 if you choose "Direct", the BIOS won't be used, and if you
2630 choose "MMConfig", then PCI Express MMCONFIG will be used.
2631 If you choose "Any", the kernel will try MMCONFIG, then the
2632 direct access method and falls back to the BIOS if that doesn't
2633 work. If unsure, go with the default, which is "Any".
2634
2635config PCI_GOBIOS
2636 bool "BIOS"
2637
2638config PCI_GOMMCONFIG
2639 bool "MMConfig"
2640
2641config PCI_GODIRECT
2642 bool "Direct"
2643
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002644config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002645 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002646 depends on OLPC
2647
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002648config PCI_GOANY
2649 bool "Any"
2650
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002651endchoice
2652
2653config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002654 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002655 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002656
2657# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2658config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002659 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002660 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002661
2662config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002663 bool "Support mmconfig PCI config space access" if X86_64
2664 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002665 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002666 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002667
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002668config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002669 def_bool y
2670 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002671
Alex Nixonb5401a92010-03-18 16:31:34 -04002672config PCI_XEN
2673 def_bool y
2674 depends on PCI && XEN
2675 select SWIOTLB_XEN
2676
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002677config MMCONF_FAM10H
2678 def_bool y
2679 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002681config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002682 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002683 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002684 help
2685 Read the PCI windows out of the CNB20LE host bridge. This allows
2686 PCI hotplug to work on systems with the CNB20LE chipset which do
2687 not have ACPI.
2688
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002689 There's no public spec for this chipset, and this functionality
2690 is known to be incomplete.
2691
2692 You should say N unless you know you need this.
2693
William Breathitt Gray3a495512016-05-27 18:08:27 -04002694config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002695 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002696 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002697 Expose ISA bus device drivers and options available for selection and
2698 configuration. Enable this option if your target machine has an ISA
2699 bus. ISA is an older system, displaced by PCI and newer bus
2700 architectures -- if your target machine is modern, it probably does
2701 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002702
2703 If unsure, say N.
2704
David Rientjes1c00f012011-03-22 16:34:59 -07002705# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002706config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002707 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2708 default y
2709 help
2710 Enables ISA-style DMA support for devices requiring such controllers.
2711 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002712
Linus Torvalds51e68d02016-05-21 10:25:19 -07002713if X86_32
2714
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002715config ISA
2716 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002717 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002718 Find out whether you have ISA slots on your motherboard. ISA is the
2719 name of a bus system, i.e. the way the CPU talks to the other stuff
2720 inside your box. Other bus systems are PCI, EISA, MicroChannel
2721 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2722 newer boards don't support it. If you have ISA, say Y, otherwise N.
2723
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002724config SCx200
2725 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002726 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002727 This provides basic support for National Semiconductor's
2728 (now AMD's) Geode processors. The driver probes for the
2729 PCI-IDs of several on-chip devices, so its a good dependency
2730 for other scx200_* drivers.
2731
2732 If compiled as a module, the driver is named scx200.
2733
2734config SCx200HR_TIMER
2735 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002736 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002737 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002738 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002739 This driver provides a clocksource built upon the on-chip
2740 27MHz high-resolution timer. Its also a workaround for
2741 NSC Geode SC-1100's buggy TSC, which loses time when the
2742 processor goes idle (as is done by the scheduler). The
2743 other workaround is idle=poll boot option.
2744
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002745config OLPC
2746 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002747 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002748 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002749 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002750 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002751 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002752 select OLPC_EC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002753 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002754 Add support for detecting the unique features of the OLPC
2755 XO hardware.
2756
Daniel Drakea3128582011-06-25 17:34:10 +01002757config OLPC_XO1_PM
2758 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002759 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002760 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002761 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002762
Daniel Drakecfee9592011-06-25 17:34:17 +01002763config OLPC_XO1_RTC
2764 bool "OLPC XO-1 Real Time Clock"
2765 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2766 ---help---
2767 Add support for the XO-1 real time clock, which can be used as a
2768 programmable wakeup source.
2769
Daniel Drake7feda8e2011-06-25 17:34:12 +01002770config OLPC_XO1_SCI
2771 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002772 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002773 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002774 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002775 ---help---
2776 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002777 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002778 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002779 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002780 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002781 - AC adapter status updates
2782 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002783
Daniel Drakea0f30f52011-06-25 17:34:18 +01002784config OLPC_XO15_SCI
2785 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002786 depends on OLPC && ACPI
2787 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002788 ---help---
2789 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2790 - EC-driven system wakeups
2791 - AC adapter status updates
2792 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002793
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002794config ALIX
2795 bool "PCEngines ALIX System Support (LED setup)"
2796 select GPIOLIB
2797 ---help---
2798 This option enables system support for the PCEngines ALIX.
2799 At present this just sets up LEDs for GPIO control on
2800 ALIX2/3/6 boards. However, other system specific setup should
2801 get added here.
2802
2803 Note: You must still enable the drivers for GPIO and LED support
2804 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2805
2806 Note: You have to set alix.force=1 for boards with Award BIOS.
2807
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002808config NET5501
2809 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2810 select GPIOLIB
2811 ---help---
2812 This option enables system support for the Soekris Engineering net5501.
2813
Philip A. Prindeville31970592012-01-14 01:45:39 -07002814config GEOS
2815 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2816 select GPIOLIB
2817 depends on DMI
2818 ---help---
2819 This option enables system support for the Traverse Technologies GEOS.
2820
Vivien Didelot7d029122013-01-04 16:18:14 -05002821config TS5500
2822 bool "Technologic Systems TS-5500 platform support"
2823 depends on MELAN
2824 select CHECK_SIGNATURE
2825 select NEW_LEDS
2826 select LEDS_CLASS
2827 ---help---
2828 This option enables system support for the Technologic Systems TS-5500.
2829
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002830endif # X86_32
2831
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002832config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002833 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002834 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002835
David Herrmanne3263ab2013-08-02 14:05:22 +02002836config X86_SYSFB
2837 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2838 help
2839 Firmwares often provide initial graphics framebuffers so the BIOS,
2840 bootloader or kernel can show basic video-output during boot for
2841 user-guidance and debugging. Historically, x86 used the VESA BIOS
2842 Extensions and EFI-framebuffers for this, which are mostly limited
2843 to x86.
2844 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2845 framebuffers so the new generic system-framebuffer drivers can be
2846 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002847 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002848 drivers like efifb, vesafb and uvesafb can pick it up.
2849 If this option is not selected, all system framebuffers are always
2850 marked as fallback platform framebuffers as usual.
2851
2852 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2853 not be able to pick up generic system framebuffers if this option
2854 is selected. You are highly encouraged to enable simplefb as
2855 replacement if you select this option. simplefb can correctly deal
2856 with generic system framebuffers. But you should still keep vesafb
2857 and others enabled as fallback if a system framebuffer is
2858 incompatible with simplefb.
2859
2860 If unsure, say Y.
2861
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002862endmenu
2863
2864
Christoph Hellwig15724972018-07-31 13:39:30 +02002865menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002866
2867config IA32_EMULATION
2868 bool "IA32 Emulation"
2869 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002870 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002871 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002872 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002873 select COMPAT_OLD_SIGACTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002874 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002875 Include code to run legacy 32-bit programs under a
2876 64-bit kernel. You should likely turn this on, unless you're
2877 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002878
2879config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002880 tristate "IA32 a.out support"
2881 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002882 depends on BROKEN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002883 ---help---
2884 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002885
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002886config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002887 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002888 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002889 ---help---
2890 Include code to run binaries for the x32 native 32-bit ABI
2891 for 64-bit processors. An x32 process gets access to the
2892 full 64-bit register file and wide data path while leaving
2893 pointers at 32 bits for smaller memory footprint.
2894
2895 You will need a recent binutils (2.22 or later) with
2896 elf32_x86_64 support enabled to compile a kernel with this
2897 option set.
2898
Ingo Molnar953fee12016-11-15 10:22:52 +01002899config COMPAT_32
2900 def_bool y
2901 depends on IA32_EMULATION || X86_32
2902 select HAVE_UID16
2903 select OLD_SIGSUSPEND3
2904
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002905config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002906 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002907 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002908
Jan Beulich3120e252012-09-10 12:41:45 +01002909if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002910config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002911 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002912
2913config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002914 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002915 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002916endif
David Howellsee009e4a02011-03-07 15:06:20 +00002917
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002918endmenu
2919
2920
Keith Packarde5beae12008-11-03 18:21:45 +01002921config HAVE_ATOMIC_IOMAP
2922 def_bool y
2923 depends on X86_32
2924
Alessandro Rubini4692d772012-04-04 19:39:58 +02002925config X86_DEV_DMA_OPS
2926 bool
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002927
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002928source "drivers/firmware/Kconfig"
2929
Avi Kivityedf88412007-12-16 11:02:48 +02002930source "arch/x86/kvm/Kconfig"