xref: /linux/arch/x86/Kconfig (revision ff61f0791ce969d2db6c9f3b71d74ceec0a2e958)
1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0
2daa93fabSSam Ravnborg# Select 32 or 64 bit
3daa93fabSSam Ravnborgconfig 64BIT
4104daea1SMasahiro Yamada	bool "64-bit kernel" if "$(ARCH)" = "x86"
5104daea1SMasahiro Yamada	default "$(ARCH)" != "i386"
6a7f7f624SMasahiro Yamada	help
7daa93fabSSam Ravnborg	  Say yes to build a 64-bit kernel - formerly known as x86_64
8daa93fabSSam Ravnborg	  Say no to build a 32-bit kernel - formerly known as i386
9daa93fabSSam Ravnborg
10daa93fabSSam Ravnborgconfig X86_32
113120e25eSJan Beulich	def_bool y
123120e25eSJan Beulich	depends on !64BIT
13341c787eSIngo Molnar	# Options that are inherently 32-bit kernel only:
14341c787eSIngo Molnar	select ARCH_WANT_IPC_PARSE_VERSION
15341c787eSIngo Molnar	select CLKSRC_I8253
16341c787eSIngo Molnar	select CLONE_BACKWARDS
17157e118bSThomas Gleixner	select GENERIC_VDSO_32
18117ed454SThomas Gleixner	select HAVE_DEBUG_STACKOVERFLOW
19157e118bSThomas Gleixner	select KMAP_LOCAL
20341c787eSIngo Molnar	select MODULES_USE_ELF_REL
21341c787eSIngo Molnar	select OLD_SIGACTION
222ca408d9SBrian Gerst	select ARCH_SPLIT_ARG64
23daa93fabSSam Ravnborg
24daa93fabSSam Ravnborgconfig X86_64
253120e25eSJan Beulich	def_bool y
263120e25eSJan Beulich	depends on 64BIT
27d94e0685SIngo Molnar	# Options that are inherently 64-bit kernel only:
284eb0716eSAlexandre Ghiti	select ARCH_HAS_GIGANTIC_PAGE
29c12d3362SArd Biesheuvel	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30d94e0685SIngo Molnar	select ARCH_USE_CMPXCHG_LOCKREF
31d94e0685SIngo Molnar	select HAVE_ARCH_SOFT_DIRTY
32d94e0685SIngo Molnar	select MODULES_USE_ELF_RELA
33f616ab59SChristoph Hellwig	select NEED_DMA_MAP_STATE
3409230cbcSChristoph Hellwig	select SWIOTLB
357facdc42SAl Viro	select ARCH_HAS_ELFCORE_COMPAT
3663703f37SKefeng Wang	select ZONE_DMA32
371032c0baSSam Ravnborg
38518049d9SSteven Rostedt (VMware)config FORCE_DYNAMIC_FTRACE
39518049d9SSteven Rostedt (VMware)	def_bool y
40518049d9SSteven Rostedt (VMware)	depends on X86_32
41518049d9SSteven Rostedt (VMware)	depends on FUNCTION_TRACER
42518049d9SSteven Rostedt (VMware)	select DYNAMIC_FTRACE
43518049d9SSteven Rostedt (VMware)	help
44518049d9SSteven Rostedt (VMware)	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45518049d9SSteven Rostedt (VMware)	  in order to test the non static function tracing in the
46518049d9SSteven Rostedt (VMware)	  generic code, as other architectures still use it. But we
47518049d9SSteven Rostedt (VMware)	  only need to keep it around for x86_64. No need to keep it
48518049d9SSteven Rostedt (VMware)	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49d94e0685SIngo Molnar#
50d94e0685SIngo Molnar# Arch settings
51d94e0685SIngo Molnar#
52d94e0685SIngo Molnar# ( Note that options that are marked 'if X86_64' could in principle be
53d94e0685SIngo Molnar#   ported to 32-bit as well. )
54d94e0685SIngo Molnar#
558d5fffb9SSam Ravnborgconfig X86
563c2362e6SHarvey Harrison	def_bool y
57c763ea26SIngo Molnar	#
58c763ea26SIngo Molnar	# Note: keep this list sorted alphabetically
59c763ea26SIngo Molnar	#
606471b825SIngo Molnar	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
616e0a0ea1SGraeme Gregory	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62942fa985SYury Norov	select ARCH_32BIT_OFF_T			if X86_32
632a21ad57SThomas Gleixner	select ARCH_CLOCKSOURCE_INIT
641f6d3a8fSMasami Hiramatsu	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
651e866974SAnshuman Khandual	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
665c11f00bSDavid Hildenbrand	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
6791024b3cSAnshuman Khandual	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68cebc774fSAnshuman Khandual	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
691e866974SAnshuman Khandual	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
7091dda51aSAleksey Makarov	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71c2280be8SAnshuman Khandual	select ARCH_HAS_CACHE_LINE_SIZE
721156b441SDavidlohr Bueso	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
732792d84eSKees Cook	select ARCH_HAS_CURRENT_STACK_POINTER
74fa5b6ec9SLaura Abbott	select ARCH_HAS_DEBUG_VIRTUAL
75399145f9SAnshuman Khandual	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
7621266be9SDan Williams	select ARCH_HAS_DEVMEM_IS_ALLOWED
77b1a57bbfSDouglas Anderson	select ARCH_HAS_EARLY_DEBUG		if KGDB
786471b825SIngo Molnar	select ARCH_HAS_ELF_RANDOMIZE
7972d93104SLinus Torvalds	select ARCH_HAS_FAST_MULTIPLIER
806974f0c4SDaniel Micay	select ARCH_HAS_FORTIFY_SOURCE
81957e3facSRiku Voipio	select ARCH_HAS_GCOV_PROFILE_ALL
82bece04b5SMarco Elver	select ARCH_HAS_KCOV			if X86_64
830c9c1d56SThiago Jung Bauermann	select ARCH_HAS_MEM_ENCRYPT
8410bcc80eSMathieu Desnoyers	select ARCH_HAS_MEMBARRIER_SYNC_CORE
8549f88c70SPaul E. McKenney	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
860ebeea8cSDaniel Borkmann	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
87c763ea26SIngo Molnar	select ARCH_HAS_PMEM_API		if X86_64
8817596731SRobin Murphy	select ARCH_HAS_PTE_DEVMAP		if X86_64
893010a5eaSLaurent Dufour	select ARCH_HAS_PTE_SPECIAL
90eed9a328SYu Zhao	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
910aed55afSDan Williams	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
92ec6347bbSDan Williams	select ARCH_HAS_COPY_MC			if X86_64
93d2852a22SDaniel Borkmann	select ARCH_HAS_SET_MEMORY
94d253ca0cSRick Edgecombe	select ARCH_HAS_SET_DIRECT_MAP
95ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_KERNEL_RWX
96ad21fc4fSLaura Abbott	select ARCH_HAS_STRICT_MODULE_RWX
97ac1ab12aSMathieu Desnoyers	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
9825c619e5SBrian Gerst	select ARCH_HAS_SYSCALL_WRAPPER
99c6d30853SAndrey Ryabinin	select ARCH_HAS_UBSAN_SANITIZE_ALL
1007e01ccb4SZong Li	select ARCH_HAS_DEBUG_WX
10163703f37SKefeng Wang	select ARCH_HAS_ZONE_DMA_SET if EXPERT
1026471b825SIngo Molnar	select ARCH_HAVE_NMI_SAFE_CMPXCHG
1036471b825SIngo Molnar	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
10477fbbc81SMark Salter	select ARCH_MIGHT_HAVE_PC_PARPORT
1055e2c18c0SMark Salter	select ARCH_MIGHT_HAVE_PC_SERIO
1063599fe12SThomas Gleixner	select ARCH_STACKWALK
1072c870e61SArnd Bergmann	select ARCH_SUPPORTS_ACPI
1086471b825SIngo Molnar	select ARCH_SUPPORTS_ATOMIC_RMW
1095d6ad668SMike Rapoport	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
110d283d422SPasha Tatashin	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
1116471b825SIngo Molnar	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
11214df3267SThomas Gleixner	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
1133c516f89SSami Tolvanen	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
1143c516f89SSami Tolvanen	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
115583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG
116583bfd48SNathan Chancellor	select ARCH_SUPPORTS_LTO_CLANG_THIN
1176471b825SIngo Molnar	select ARCH_USE_BUILTIN_BSWAP
118dce44566SAnshuman Khandual	select ARCH_USE_MEMTEST
1196471b825SIngo Molnar	select ARCH_USE_QUEUED_RWLOCKS
1206471b825SIngo Molnar	select ARCH_USE_QUEUED_SPINLOCKS
1212ce0d7f9SMark Brown	select ARCH_USE_SYM_ANNOTATIONS
122ce4a4e56SAndy Lutomirski	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
12381c22041SDaniel Borkmann	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
124c763ea26SIngo Molnar	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
12551c2ee6dSNick Desaulniers	select ARCH_WANTS_NO_INSTR
12607431506SAnshuman Khandual	select ARCH_WANT_GENERAL_HUGETLB
1273876d4a3SAlexandre Ghiti	select ARCH_WANT_HUGE_PMD_SHARE
12847010c04SMuchun Song	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
12959612b24SNathan Chancellor	select ARCH_WANT_LD_ORPHAN_WARN
13038d8b4e6SHuang Ying	select ARCH_WANTS_THP_SWAP		if X86_64
131b5f06f64SBalbir Singh	select ARCH_HAS_PARANOID_L1D_FLUSH
13210916706SShile Zhang	select BUILDTIME_TABLE_SORT
1336471b825SIngo Molnar	select CLKEVT_I8253
1346471b825SIngo Molnar	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
1356471b825SIngo Molnar	select CLOCKSOURCE_WATCHDOG
1367cf8f44aSAlexander Potapenko	# Word-size accesses may read uninitialized data past the trailing \0
1377cf8f44aSAlexander Potapenko	# in strings and cause false KMSAN reports.
1387cf8f44aSAlexander Potapenko	select DCACHE_WORD_ACCESS		if !KMSAN
1393aac3ebeSThomas Gleixner	select DYNAMIC_SIGFRAME
14045471cd9SLinus Torvalds	select EDAC_ATOMIC_SCRUB
14145471cd9SLinus Torvalds	select EDAC_SUPPORT
1426471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
1436471b825SIngo Molnar	select GENERIC_CLOCKEVENTS_MIN_ADJUST
1446471b825SIngo Molnar	select GENERIC_CMOS_UPDATE
1456471b825SIngo Molnar	select GENERIC_CPU_AUTOPROBE
14661dc0f55SThomas Gleixner	select GENERIC_CPU_VULNERABILITIES
1476471b825SIngo Molnar	select GENERIC_EARLY_IOREMAP
14827d6b4d1SThomas Gleixner	select GENERIC_ENTRY
1496471b825SIngo Molnar	select GENERIC_IOMAP
150c7d6c9ddSThomas Gleixner	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
1510fa115daSThomas Gleixner	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
152ad7a929fSThomas Gleixner	select GENERIC_IRQ_MIGRATION		if SMP
1536471b825SIngo Molnar	select GENERIC_IRQ_PROBE
154c201c917SThomas Gleixner	select GENERIC_IRQ_RESERVATION_MODE
1556471b825SIngo Molnar	select GENERIC_IRQ_SHOW
1566471b825SIngo Molnar	select GENERIC_PENDING_IRQ		if SMP
1572ae27137SSteven Price	select GENERIC_PTDUMP
1586471b825SIngo Molnar	select GENERIC_SMP_IDLE_THREAD
1596471b825SIngo Molnar	select GENERIC_TIME_VSYSCALL
1607ac87074SVincenzo Frascino	select GENERIC_GETTIMEOFDAY
161550a77a7SDmitry Safonov	select GENERIC_VDSO_TIME_NS
1626ca297d4SPeter Zijlstra	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
16317e5888eSHans de Goede	select HARDIRQS_SW_RESEND
1647edaeb68SThomas Gleixner	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
1656471b825SIngo Molnar	select HAVE_ACPI_APEI			if ACPI
1666471b825SIngo Molnar	select HAVE_ACPI_APEI_NMI		if ACPI
1676471b825SIngo Molnar	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
1686471b825SIngo Molnar	select HAVE_ARCH_AUDITSYSCALL
1696471b825SIngo Molnar	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
170eed1fceeSSong Liu	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
1716471b825SIngo Molnar	select HAVE_ARCH_JUMP_LABEL
172b34006c4SArd Biesheuvel	select HAVE_ARCH_JUMP_LABEL_RELATIVE
173d17a1d97SAndrey Ryabinin	select HAVE_ARCH_KASAN			if X86_64
1740609ae01SDaniel Axtens	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
1751dc0da6eSAlexander Potapenko	select HAVE_ARCH_KFENCE
1764ca8cc8dSAlexander Potapenko	select HAVE_ARCH_KMSAN			if X86_64
1776471b825SIngo Molnar	select HAVE_ARCH_KGDB
1789e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_BITS		if MMU
1799e08f57dSDaniel Cashman	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
1801b028f78SDmitry Safonov	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
181271ca788SArd Biesheuvel	select HAVE_ARCH_PREL32_RELOCATIONS
1826471b825SIngo Molnar	select HAVE_ARCH_SECCOMP_FILTER
183f7d83c1cSKees Cook	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
184afaef01cSAlexander Popov	select HAVE_ARCH_STACKLEAK
1856471b825SIngo Molnar	select HAVE_ARCH_TRACEHOOK
1866471b825SIngo Molnar	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
187a00cc7d9SMatthew Wilcox	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
188b64d8d1eSPeter Xu	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
1897677f7fdSAxel Rasmussen	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
190e37e43a4SAndy Lutomirski	select HAVE_ARCH_VMAP_STACK		if X86_64
191fe950f60SKees Cook	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
192c763ea26SIngo Molnar	select HAVE_ARCH_WITHIN_STACK_FRAMES
1932ff2b7ecSMasahiro Yamada	select HAVE_ASM_MODVERSIONS
1946471b825SIngo Molnar	select HAVE_CMPXCHG_DOUBLE
1956471b825SIngo Molnar	select HAVE_CMPXCHG_LOCAL
19624a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER		if X86_64
19724a9c541SFrederic Weisbecker	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
1986471b825SIngo Molnar	select HAVE_C_RECORDMCOUNT
19903f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
200280981d6SSathvika Vasireddy	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
2014ed308c4SSteven Rostedt (Google)	select HAVE_BUILDTIME_MCOUNT_SORT
2026471b825SIngo Molnar	select HAVE_DEBUG_KMEMLEAK
2039c5a3621SAkinobu Mita	select HAVE_DMA_CONTIGUOUS
204677aa9f7SSteven Rostedt	select HAVE_DYNAMIC_FTRACE
20506aeaaeaSMasami Hiramatsu	select HAVE_DYNAMIC_FTRACE_WITH_REGS
20602a474caSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
207562955feSSteven Rostedt (VMware)	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
208c316eb44SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
209503e4510SHeiko Carstens	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
21003f5781bSWang YanQing	select HAVE_EBPF_JIT
21158340a07SJohannes Berg	select HAVE_EFFICIENT_UNALIGNED_ACCESS
2126630a8e5SChristoph Hellwig	select HAVE_EISA
2135f56a5dfSJiri Slaby	select HAVE_EXIT_THREAD
21467a929e0SChristoph Hellwig	select HAVE_FAST_GUP
215644e0e8dSSteven Rostedt (VMware)	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
2166471b825SIngo Molnar	select HAVE_FTRACE_MCOUNT_RECORD
2174a30e4c9SSteven Rostedt (VMware)	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
2186471b825SIngo Molnar	select HAVE_FUNCTION_TRACER
2196b90bd4bSEmese Revfy	select HAVE_GCC_PLUGINS
2200067f129SK.Prasad	select HAVE_HW_BREAKPOINT
2216471b825SIngo Molnar	select HAVE_IOREMAP_PROT
222624db9eaSThomas Gleixner	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
2236471b825SIngo Molnar	select HAVE_IRQ_TIME_ACCOUNTING
2244ab7674fSJosh Poimboeuf	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
2256471b825SIngo Molnar	select HAVE_KERNEL_BZIP2
2266471b825SIngo Molnar	select HAVE_KERNEL_GZIP
2276471b825SIngo Molnar	select HAVE_KERNEL_LZ4
2286471b825SIngo Molnar	select HAVE_KERNEL_LZMA
2296471b825SIngo Molnar	select HAVE_KERNEL_LZO
2306471b825SIngo Molnar	select HAVE_KERNEL_XZ
231fb46d057SNick Terrell	select HAVE_KERNEL_ZSTD
2326471b825SIngo Molnar	select HAVE_KPROBES
2336471b825SIngo Molnar	select HAVE_KPROBES_ON_FTRACE
234540adea3SMasami Hiramatsu	select HAVE_FUNCTION_ERROR_INJECTION
2356471b825SIngo Molnar	select HAVE_KRETPROBES
236f3a112c0SMasami Hiramatsu	select HAVE_RETHOOK
2376471b825SIngo Molnar	select HAVE_KVM
2386471b825SIngo Molnar	select HAVE_LIVEPATCH			if X86_64
2390102752eSFrederic Weisbecker	select HAVE_MIXED_BREAKPOINTS_REGS
240ee9f8fceSJosh Poimboeuf	select HAVE_MOD_ARCH_SPECIFIC
2419f132f7eSJoel Fernandes (Google)	select HAVE_MOVE_PMD
242be37c98dSKalesh Singh	select HAVE_MOVE_PUD
24322102f45SJosh Poimboeuf	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
24442a0bb3fSPetr Mladek	select HAVE_NMI
245489e355bSJosh Poimboeuf	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
24603f16cd0SJosh Poimboeuf	select HAVE_OBJTOOL			if X86_64
2476471b825SIngo Molnar	select HAVE_OPTPROBES
2486471b825SIngo Molnar	select HAVE_PCSPKR_PLATFORM
2496471b825SIngo Molnar	select HAVE_PERF_EVENTS
250c01d4323SFrederic Weisbecker	select HAVE_PERF_EVENTS_NMI
25192e5aae4SNicholas Piggin	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
252eb01d42aSChristoph Hellwig	select HAVE_PCI
253c5e63197SJiri Olsa	select HAVE_PERF_REGS
254c5ebcedbSJiri Olsa	select HAVE_PERF_USER_STACK_DUMP
255ff2e6d72SPeter Zijlstra	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
2561e9fdf21SPeter Zijlstra	select MMU_GATHER_MERGE_VMAS
25700998085SThomas Gleixner	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
2586471b825SIngo Molnar	select HAVE_REGS_AND_STACK_ACCESS_API
25903f16cd0SJosh Poimboeuf	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
2603c88ee19SMasami Hiramatsu	select HAVE_FUNCTION_ARG_ACCESS_API
2617ecd19cfSKefeng Wang	select HAVE_SETUP_PER_CPU_AREA
262cd1a41ceSThomas Gleixner	select HAVE_SOFTIRQ_ON_OWN_STACK
263d148eac0SMasahiro Yamada	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
26403f16cd0SJosh Poimboeuf	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
265e6d6c071SJosh Poimboeuf	select HAVE_STATIC_CALL
26603f16cd0SJosh Poimboeuf	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
26799cf983cSMark Rutland	select HAVE_PREEMPT_DYNAMIC_CALL
268d6761b8fSMathieu Desnoyers	select HAVE_RSEQ
26909498135SMiguel Ojeda	select HAVE_RUST			if X86_64
2706471b825SIngo Molnar	select HAVE_SYSCALL_TRACEPOINTS
2715f3da8c0SJosh Poimboeuf	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
2726471b825SIngo Molnar	select HAVE_UNSTABLE_SCHED_CLOCK
2737c68af6eSAvi Kivity	select HAVE_USER_RETURN_NOTIFIER
2747ac87074SVincenzo Frascino	select HAVE_GENERIC_VDSO
27505736e4aSThomas Gleixner	select HOTPLUG_SMT			if SMP
276c0185808SThomas Gleixner	select IRQ_FORCED_THREADING
2777ecd19cfSKefeng Wang	select NEED_PER_CPU_EMBED_FIRST_CHUNK
2787ecd19cfSKefeng Wang	select NEED_PER_CPU_PAGE_FIRST_CHUNK
27986596f0aSChristoph Hellwig	select NEED_SG_DMA_LENGTH
2802eac9c2dSChristoph Hellwig	select PCI_DOMAINS			if PCI
281625210cfSSinan Kaya	select PCI_LOCKLESS_CONFIG		if PCI
2826471b825SIngo Molnar	select PERF_EVENTS
2833195ef59SPrarit Bhargava	select RTC_LIB
284d6faca40SArnd Bergmann	select RTC_MC146818_LIB
2856471b825SIngo Molnar	select SPARSE_IRQ
28683fe27eaSPranith Kumar	select SRCU
2876471b825SIngo Molnar	select SYSCTL_EXCEPTION_TRACE
28815f4eae7SAndy Lutomirski	select THREAD_INFO_IN_TASK
2894aae683fSMasahiro Yamada	select TRACE_IRQFLAGS_SUPPORT
2904510bffbSMark Rutland	select TRACE_IRQFLAGS_NMI_SUPPORT
2916471b825SIngo Molnar	select USER_STACKTRACE_SUPPORT
2923b02a051SIngo Molnar	select HAVE_ARCH_KCSAN			if X86_64
2936471b825SIngo Molnar	select X86_FEATURE_NAMES		if PROC_FS
2940c608dadSAubrey Li	select PROC_PID_ARCH_STATUS		if PROC_FS
29550468e43SJarkko Sakkinen	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
296d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
297d49a0626SPeter Zijlstra	select FUNCTION_ALIGNMENT_4B
2989e2b4be3SNayna Jain	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
299ceea991aSJiri Olsa	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
3007d8330a5SBalbir Singh
301ba7e4d13SIngo Molnarconfig INSTRUCTION_DECODER
3023120e25eSJan Beulich	def_bool y
3033120e25eSJan Beulich	depends on KPROBES || PERF_EVENTS || UPROBES
304ba7e4d13SIngo Molnar
30551b26adaSLinus Torvaldsconfig OUTPUT_FORMAT
30651b26adaSLinus Torvalds	string
30751b26adaSLinus Torvalds	default "elf32-i386" if X86_32
30851b26adaSLinus Torvalds	default "elf64-x86-64" if X86_64
30951b26adaSLinus Torvalds
3108d5fffb9SSam Ravnborgconfig LOCKDEP_SUPPORT
3113c2362e6SHarvey Harrison	def_bool y
3128d5fffb9SSam Ravnborg
3138d5fffb9SSam Ravnborgconfig STACKTRACE_SUPPORT
3143c2362e6SHarvey Harrison	def_bool y
3158d5fffb9SSam Ravnborg
3168d5fffb9SSam Ravnborgconfig MMU
3173c2362e6SHarvey Harrison	def_bool y
3188d5fffb9SSam Ravnborg
3199e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN
3209e08f57dSDaniel Cashman	default 28 if 64BIT
3219e08f57dSDaniel Cashman	default 8
3229e08f57dSDaniel Cashman
3239e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX
3249e08f57dSDaniel Cashman	default 32 if 64BIT
3259e08f57dSDaniel Cashman	default 16
3269e08f57dSDaniel Cashman
3279e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
3289e08f57dSDaniel Cashman	default 8
3299e08f57dSDaniel Cashman
3309e08f57dSDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
3319e08f57dSDaniel Cashman	default 16
3329e08f57dSDaniel Cashman
3338d5fffb9SSam Ravnborgconfig SBUS
3348d5fffb9SSam Ravnborg	bool
3358d5fffb9SSam Ravnborg
3368d5fffb9SSam Ravnborgconfig GENERIC_ISA_DMA
3373120e25eSJan Beulich	def_bool y
3383120e25eSJan Beulich	depends on ISA_DMA_API
3398d5fffb9SSam Ravnborg
340d911c67eSAlexander Potapenkoconfig GENERIC_CSUM
341d911c67eSAlexander Potapenko	bool
342d911c67eSAlexander Potapenko	default y if KMSAN || KASAN
343d911c67eSAlexander Potapenko
3448d5fffb9SSam Ravnborgconfig GENERIC_BUG
3453c2362e6SHarvey Harrison	def_bool y
3468d5fffb9SSam Ravnborg	depends on BUG
347b93a531eSJan Beulich	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
348b93a531eSJan Beulich
349b93a531eSJan Beulichconfig GENERIC_BUG_RELATIVE_POINTERS
350b93a531eSJan Beulich	bool
3518d5fffb9SSam Ravnborg
3528d5fffb9SSam Ravnborgconfig ARCH_MAY_HAVE_PC_FDC
3533120e25eSJan Beulich	def_bool y
3543120e25eSJan Beulich	depends on ISA_DMA_API
3558d5fffb9SSam Ravnborg
3561032c0baSSam Ravnborgconfig GENERIC_CALIBRATE_DELAY
3571032c0baSSam Ravnborg	def_bool y
3581032c0baSSam Ravnborg
3599a0b8415Svenkatesh.pallipadi@intel.comconfig ARCH_HAS_CPU_RELAX
3609a0b8415Svenkatesh.pallipadi@intel.com	def_bool y
3618d5fffb9SSam Ravnborg
362801e4062SJohannes Bergconfig ARCH_HIBERNATION_POSSIBLE
363801e4062SJohannes Berg	def_bool y
364801e4062SJohannes Berg
365f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE
366f4cb5700SJohannes Berg	def_bool y
367f4cb5700SJohannes Berg
3688d5fffb9SSam Ravnborgconfig AUDIT_ARCH
369e0fd24a3SJan Beulich	def_bool y if X86_64
3708d5fffb9SSam Ravnborg
371d6f2d75aSAndrey Ryabininconfig KASAN_SHADOW_OFFSET
372d6f2d75aSAndrey Ryabinin	hex
373d6f2d75aSAndrey Ryabinin	depends on KASAN
374d6f2d75aSAndrey Ryabinin	default 0xdffffc0000000000
375d6f2d75aSAndrey Ryabinin
37669575d38SShane Wangconfig HAVE_INTEL_TXT
37769575d38SShane Wang	def_bool y
3786ea30386SKees Cook	depends on INTEL_IOMMU && ACPI
37969575d38SShane Wang
3806b0c3d44SSam Ravnborgconfig X86_32_SMP
3816b0c3d44SSam Ravnborg	def_bool y
3826b0c3d44SSam Ravnborg	depends on X86_32 && SMP
3836b0c3d44SSam Ravnborg
3846b0c3d44SSam Ravnborgconfig X86_64_SMP
3856b0c3d44SSam Ravnborg	def_bool y
3866b0c3d44SSam Ravnborg	depends on X86_64 && SMP
3876b0c3d44SSam Ravnborg
3882b144498SSrikar Dronamrajuconfig ARCH_SUPPORTS_UPROBES
3892b144498SSrikar Dronamraju	def_bool y
3902b144498SSrikar Dronamraju
391d20642f0SRob Herringconfig FIX_EARLYCON_MEM
392d20642f0SRob Herring	def_bool y
393d20642f0SRob Herring
39494d49eb3SKirill A. Shutemovconfig DYNAMIC_PHYSICAL_MASK
39594d49eb3SKirill A. Shutemov	bool
39694d49eb3SKirill A. Shutemov
39798233368SKirill A. Shutemovconfig PGTABLE_LEVELS
39898233368SKirill A. Shutemov	int
39977ef56e4SKirill A. Shutemov	default 5 if X86_5LEVEL
40098233368SKirill A. Shutemov	default 4 if X86_64
40198233368SKirill A. Shutemov	default 3 if X86_PAE
40298233368SKirill A. Shutemov	default 2
40398233368SKirill A. Shutemov
4042a61f474SMasahiro Yamadaconfig CC_HAS_SANE_STACKPROTECTOR
4052a61f474SMasahiro Yamada	bool
4061b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
4071b866781SNathan Chancellor	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
4082a61f474SMasahiro Yamada	help
4092a61f474SMasahiro Yamada	  We have to make sure stack protector is unconditionally disabled if
4103fb0fdb3SAndy Lutomirski	  the compiler produces broken code or if it does not let us control
4113fb0fdb3SAndy Lutomirski	  the segment on 32-bit kernels.
4122a61f474SMasahiro Yamada
413506f1d07SSam Ravnborgmenu "Processor type and features"
414506f1d07SSam Ravnborg
415506f1d07SSam Ravnborgconfig SMP
416506f1d07SSam Ravnborg	bool "Symmetric multi-processing support"
417a7f7f624SMasahiro Yamada	help
418506f1d07SSam Ravnborg	  This enables support for systems with more than one CPU. If you have
4194a474157SRobert Graffham	  a system with only one CPU, say N. If you have a system with more
4204a474157SRobert Graffham	  than one CPU, say Y.
421506f1d07SSam Ravnborg
4224a474157SRobert Graffham	  If you say N here, the kernel will run on uni- and multiprocessor
423506f1d07SSam Ravnborg	  machines, but will use only one CPU of a multiprocessor machine. If
424506f1d07SSam Ravnborg	  you say Y here, the kernel will run on many, but not all,
4254a474157SRobert Graffham	  uniprocessor machines. On a uniprocessor machine, the kernel
426506f1d07SSam Ravnborg	  will run faster if you say N here.
427506f1d07SSam Ravnborg
428506f1d07SSam Ravnborg	  Note that if you say Y here and choose architecture "586" or
429506f1d07SSam Ravnborg	  "Pentium" under "Processor family", the kernel will not work on 486
430506f1d07SSam Ravnborg	  architectures. Similarly, multiprocessor kernels for the "PPro"
431506f1d07SSam Ravnborg	  architecture may not work on all Pentium based boards.
432506f1d07SSam Ravnborg
433506f1d07SSam Ravnborg	  People using multiprocessor machines who say Y here should also say
434506f1d07SSam Ravnborg	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
435506f1d07SSam Ravnborg	  Management" code will be disabled if you say Y here.
436506f1d07SSam Ravnborg
437*ff61f079SJonathan Corbet	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
4384f4cfa6cSMauro Carvalho Chehab	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
439506f1d07SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
440506f1d07SSam Ravnborg
441506f1d07SSam Ravnborg	  If you don't know what to do here, say N.
442506f1d07SSam Ravnborg
4439def39beSJosh Triplettconfig X86_FEATURE_NAMES
4449def39beSJosh Triplett	bool "Processor feature human-readable names" if EMBEDDED
4459def39beSJosh Triplett	default y
446a7f7f624SMasahiro Yamada	help
4479def39beSJosh Triplett	  This option compiles in a table of x86 feature bits and corresponding
4489def39beSJosh Triplett	  names.  This is required to support /proc/cpuinfo and a few kernel
4499def39beSJosh Triplett	  messages.  You can disable this to save space, at the expense of
4509def39beSJosh Triplett	  making those few kernel messages show numeric feature bits instead.
4519def39beSJosh Triplett
4529def39beSJosh Triplett	  If in doubt, say Y.
4539def39beSJosh Triplett
45406cd9a7dSYinghai Luconfig X86_X2APIC
45506cd9a7dSYinghai Lu	bool "Support x2apic"
45619e3d60dSJan Kiszka	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
457a7f7f624SMasahiro Yamada	help
45806cd9a7dSYinghai Lu	  This enables x2apic support on CPUs that have this feature.
45906cd9a7dSYinghai Lu
46006cd9a7dSYinghai Lu	  This allows 32-bit apic IDs (so it can support very large systems),
46106cd9a7dSYinghai Lu	  and accesses the local apic via MSRs not via mmio.
46206cd9a7dSYinghai Lu
463b8d1d163SDaniel Sneddon	  Some Intel systems circa 2022 and later are locked into x2APIC mode
464b8d1d163SDaniel Sneddon	  and can not fall back to the legacy APIC modes if SGX or TDX are
465e3998434SMateusz Jończyk	  enabled in the BIOS. They will boot with very reduced functionality
466e3998434SMateusz Jończyk	  without enabling this option.
467b8d1d163SDaniel Sneddon
46806cd9a7dSYinghai Lu	  If you don't know what to do here, say N.
46906cd9a7dSYinghai Lu
4706695c85bSYinghai Luconfig X86_MPPARSE
4714590d98fSAndy Shevchenko	bool "Enable MPS table" if ACPI
4727a527688SJan Beulich	default y
4735ab74722SIngo Molnar	depends on X86_LOCAL_APIC
474a7f7f624SMasahiro Yamada	help
4756695c85bSYinghai Lu	  For old smp systems that do not have proper acpi support. Newer systems
4766695c85bSYinghai Lu	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
4776695c85bSYinghai Lu
478ddd70cf9SJun Nakajimaconfig GOLDFISH
479ddd70cf9SJun Nakajima	def_bool y
480ddd70cf9SJun Nakajima	depends on X86_GOLDFISH
481ddd70cf9SJun Nakajima
482e6d42931SJohannes Weinerconfig X86_CPU_RESCTRL
483e6d42931SJohannes Weiner	bool "x86 CPU resource control support"
4846fe07ce3SBabu Moger	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
48559fe5a77SThomas Gleixner	select KERNFS
486e79f15a4SChen Yu	select PROC_CPU_RESCTRL		if PROC_FS
48778e99b4aSFenghua Yu	help
488e6d42931SJohannes Weiner	  Enable x86 CPU resource control support.
4896fe07ce3SBabu Moger
4906fe07ce3SBabu Moger	  Provide support for the allocation and monitoring of system resources
4916fe07ce3SBabu Moger	  usage by the CPU.
4926fe07ce3SBabu Moger
4936fe07ce3SBabu Moger	  Intel calls this Intel Resource Director Technology
4946fe07ce3SBabu Moger	  (Intel(R) RDT). More information about RDT can be found in the
4956fe07ce3SBabu Moger	  Intel x86 Architecture Software Developer Manual.
4966fe07ce3SBabu Moger
4976fe07ce3SBabu Moger	  AMD calls this AMD Platform Quality of Service (AMD QoS).
4986fe07ce3SBabu Moger	  More information about AMD QoS can be found in the AMD64 Technology
4996fe07ce3SBabu Moger	  Platform Quality of Service Extensions manual.
50078e99b4aSFenghua Yu
50178e99b4aSFenghua Yu	  Say N if unsure.
50278e99b4aSFenghua Yu
5038425091fSRavikiran G Thirumalaiif X86_32
504a0d0bb4dSRandy Dunlapconfig X86_BIGSMP
505a0d0bb4dSRandy Dunlap	bool "Support for big SMP systems with more than 8 CPUs"
506a0d0bb4dSRandy Dunlap	depends on SMP
507a7f7f624SMasahiro Yamada	help
508e133f6eaSRandy Dunlap	  This option is needed for the systems that have more than 8 CPUs.
509a0d0bb4dSRandy Dunlap
510c5c606d9SRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
511c5c606d9SRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
512c5c606d9SRavikiran G Thirumalai	default y
513a7f7f624SMasahiro Yamada	help
51406ac8346SIngo Molnar	  If you disable this option then the kernel will only support
51506ac8346SIngo Molnar	  standard PC platforms. (which covers the vast majority of
51606ac8346SIngo Molnar	  systems out there.)
51706ac8346SIngo Molnar
5188425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5198425091fSRavikiran G Thirumalai	  for the following (non-PC) 32 bit x86 platforms:
520cb7b8023SBen Hutchings		Goldfish (Android emulator)
5218425091fSRavikiran G Thirumalai		AMD Elan
5228425091fSRavikiran G Thirumalai		RDC R-321x SoC
5238425091fSRavikiran G Thirumalai		SGI 320/540 (Visual Workstation)
52483125a3aSAlessandro Rubini		STA2X11-based (e.g. Northville)
5253f4110a4SThomas Gleixner		Moorestown MID devices
52606ac8346SIngo Molnar
52706ac8346SIngo Molnar	  If you have one of these systems, or if you want to build a
52806ac8346SIngo Molnar	  generic distribution kernel, say Y here - otherwise say N.
529758cd94aSJuerg Haefligerendif # X86_32
53006ac8346SIngo Molnar
5318425091fSRavikiran G Thirumalaiif X86_64
5328425091fSRavikiran G Thirumalaiconfig X86_EXTENDED_PLATFORM
5338425091fSRavikiran G Thirumalai	bool "Support for extended (non-PC) x86 platforms"
5348425091fSRavikiran G Thirumalai	default y
535a7f7f624SMasahiro Yamada	help
5368425091fSRavikiran G Thirumalai	  If you disable this option then the kernel will only support
5378425091fSRavikiran G Thirumalai	  standard PC platforms. (which covers the vast majority of
5388425091fSRavikiran G Thirumalai	  systems out there.)
5398425091fSRavikiran G Thirumalai
5408425091fSRavikiran G Thirumalai	  If you enable this option then you'll be able to select support
5418425091fSRavikiran G Thirumalai	  for the following (non-PC) 64 bit x86 platforms:
54244b111b5SSteffen Persvold		Numascale NumaChip
5438425091fSRavikiran G Thirumalai		ScaleMP vSMP
5448425091fSRavikiran G Thirumalai		SGI Ultraviolet
5458425091fSRavikiran G Thirumalai
5468425091fSRavikiran G Thirumalai	  If you have one of these systems, or if you want to build a
5478425091fSRavikiran G Thirumalai	  generic distribution kernel, say Y here - otherwise say N.
548758cd94aSJuerg Haefligerendif # X86_64
549c5c606d9SRavikiran G Thirumalai# This is an alphabetically sorted list of 64 bit extended platforms
550c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
55144b111b5SSteffen Persvoldconfig X86_NUMACHIP
55244b111b5SSteffen Persvold	bool "Numascale NumaChip"
55344b111b5SSteffen Persvold	depends on X86_64
55444b111b5SSteffen Persvold	depends on X86_EXTENDED_PLATFORM
55544b111b5SSteffen Persvold	depends on NUMA
55644b111b5SSteffen Persvold	depends on SMP
55744b111b5SSteffen Persvold	depends on X86_X2APIC
558f9726bfdSDaniel J Blueman	depends on PCI_MMCONFIG
559a7f7f624SMasahiro Yamada	help
56044b111b5SSteffen Persvold	  Adds support for Numascale NumaChip large-SMP systems. Needed to
56144b111b5SSteffen Persvold	  enable more than ~168 cores.
56244b111b5SSteffen Persvold	  If you don't have one of these, you should say N here.
56303b48632SNick Piggin
5646a48565eSIngo Molnarconfig X86_VSMP
565c5c606d9SRavikiran G Thirumalai	bool "ScaleMP vSMP"
5666276a074SBorislav Petkov	select HYPERVISOR_GUEST
5676a48565eSIngo Molnar	select PARAVIRT
5686a48565eSIngo Molnar	depends on X86_64 && PCI
569c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
570ead91d4bSShai Fultheim	depends on SMP
571a7f7f624SMasahiro Yamada	help
5726a48565eSIngo Molnar	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
5736a48565eSIngo Molnar	  supposed to run on these EM64T-based machines.  Only choose this option
5746a48565eSIngo Molnar	  if you have one of these machines.
5756a48565eSIngo Molnar
576c5c606d9SRavikiran G Thirumalaiconfig X86_UV
577c5c606d9SRavikiran G Thirumalai	bool "SGI Ultraviolet"
578c5c606d9SRavikiran G Thirumalai	depends on X86_64
579c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
58054c28d29SJack Steiner	depends on NUMA
5811ecb4ae5SAndrew Morton	depends on EFI
582c2209ea5SIngo Molnar	depends on KEXEC_CORE
5839d6c26e7SSuresh Siddha	depends on X86_X2APIC
5841222e564SIngo Molnar	depends on PCI
585a7f7f624SMasahiro Yamada	help
586c5c606d9SRavikiran G Thirumalai	  This option is needed in order to support SGI Ultraviolet systems.
587c5c606d9SRavikiran G Thirumalai	  If you don't have one of these, you should say N here.
588c5c606d9SRavikiran G Thirumalai
589c5c606d9SRavikiran G Thirumalai# Following is an alphabetically sorted list of 32 bit extended platforms
590c5c606d9SRavikiran G Thirumalai# Please maintain the alphabetic order if and when there are additions
591506f1d07SSam Ravnborg
592ddd70cf9SJun Nakajimaconfig X86_GOLDFISH
593ddd70cf9SJun Nakajima	bool "Goldfish (Virtual Platform)"
594cb7b8023SBen Hutchings	depends on X86_EXTENDED_PLATFORM
595a7f7f624SMasahiro Yamada	help
596ddd70cf9SJun Nakajima	  Enable support for the Goldfish virtual platform used primarily
597ddd70cf9SJun Nakajima	  for Android development. Unless you are building for the Android
598ddd70cf9SJun Nakajima	  Goldfish emulator say N here.
599ddd70cf9SJun Nakajima
600c751e17bSThomas Gleixnerconfig X86_INTEL_CE
601c751e17bSThomas Gleixner	bool "CE4100 TV platform"
602c751e17bSThomas Gleixner	depends on PCI
603c751e17bSThomas Gleixner	depends on PCI_GODIRECT
6046084a6e2SJiang Liu	depends on X86_IO_APIC
605c751e17bSThomas Gleixner	depends on X86_32
606c751e17bSThomas Gleixner	depends on X86_EXTENDED_PLATFORM
60737bc9f50SDirk Brandewie	select X86_REBOOTFIXUPS
608da6b737bSSebastian Andrzej Siewior	select OF
609da6b737bSSebastian Andrzej Siewior	select OF_EARLY_FLATTREE
610a7f7f624SMasahiro Yamada	help
611c751e17bSThomas Gleixner	  Select for the Intel CE media processor (CE4100) SOC.
612c751e17bSThomas Gleixner	  This option compiles in support for the CE4100 SOC for settop
613c751e17bSThomas Gleixner	  boxes and media devices.
614c751e17bSThomas Gleixner
6154cb9b00fSDavid Cohenconfig X86_INTEL_MID
61643605ef1SAlan Cox	bool "Intel MID platform support"
61743605ef1SAlan Cox	depends on X86_EXTENDED_PLATFORM
618edc6bc78SDavid Cohen	depends on X86_PLATFORM_DEVICES
6191ea7c673SAlan Cox	depends on PCI
6203fda5bb4SAndy Shevchenko	depends on X86_64 || (PCI_GOANY && X86_32)
6211ea7c673SAlan Cox	depends on X86_IO_APIC
6224cb9b00fSDavid Cohen	select I2C
6237c9c3a1eSAlan Cox	select DW_APB_TIMER
62454b34aa0SMika Westerberg	select INTEL_SCU_PCI
625a7f7f624SMasahiro Yamada	help
6264cb9b00fSDavid Cohen	  Select to build a kernel capable of supporting Intel MID (Mobile
6274cb9b00fSDavid Cohen	  Internet Device) platform systems which do not have the PCI legacy
6284cb9b00fSDavid Cohen	  interfaces. If you are building for a PC class system say N here.
6291ea7c673SAlan Cox
6304cb9b00fSDavid Cohen	  Intel MID platforms are based on an Intel processor and chipset which
6314cb9b00fSDavid Cohen	  consume less power than most of the x86 derivatives.
63243605ef1SAlan Cox
6338bbc2a13SBryan O'Donoghueconfig X86_INTEL_QUARK
6348bbc2a13SBryan O'Donoghue	bool "Intel Quark platform support"
6358bbc2a13SBryan O'Donoghue	depends on X86_32
6368bbc2a13SBryan O'Donoghue	depends on X86_EXTENDED_PLATFORM
6378bbc2a13SBryan O'Donoghue	depends on X86_PLATFORM_DEVICES
6388bbc2a13SBryan O'Donoghue	depends on X86_TSC
6398bbc2a13SBryan O'Donoghue	depends on PCI
6408bbc2a13SBryan O'Donoghue	depends on PCI_GOANY
6418bbc2a13SBryan O'Donoghue	depends on X86_IO_APIC
6428bbc2a13SBryan O'Donoghue	select IOSF_MBI
6438bbc2a13SBryan O'Donoghue	select INTEL_IMR
6449ab6eb51SAndy Shevchenko	select COMMON_CLK
645a7f7f624SMasahiro Yamada	help
6468bbc2a13SBryan O'Donoghue	  Select to include support for Quark X1000 SoC.
6478bbc2a13SBryan O'Donoghue	  Say Y here if you have a Quark based system such as the Arduino
6488bbc2a13SBryan O'Donoghue	  compatible Intel Galileo.
6498bbc2a13SBryan O'Donoghue
6503d48aab1SMika Westerbergconfig X86_INTEL_LPSS
6513d48aab1SMika Westerberg	bool "Intel Low Power Subsystem Support"
6525962dd22SSinan Kaya	depends on X86 && ACPI && PCI
6533d48aab1SMika Westerberg	select COMMON_CLK
6540f531431SMathias Nyman	select PINCTRL
655eebb3e8dSAndy Shevchenko	select IOSF_MBI
656a7f7f624SMasahiro Yamada	help
6573d48aab1SMika Westerberg	  Select to build support for Intel Low Power Subsystem such as
6583d48aab1SMika Westerberg	  found on Intel Lynxpoint PCH. Selecting this option enables
6590f531431SMathias Nyman	  things like clock tree (common clock framework) and pincontrol
6600f531431SMathias Nyman	  which are needed by the LPSS peripheral drivers.
6613d48aab1SMika Westerberg
66292082a88SKen Xueconfig X86_AMD_PLATFORM_DEVICE
66392082a88SKen Xue	bool "AMD ACPI2Platform devices support"
66492082a88SKen Xue	depends on ACPI
66592082a88SKen Xue	select COMMON_CLK
66692082a88SKen Xue	select PINCTRL
667a7f7f624SMasahiro Yamada	help
66892082a88SKen Xue	  Select to interpret AMD specific ACPI device to platform device
66992082a88SKen Xue	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
67092082a88SKen Xue	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
67192082a88SKen Xue	  implemented under PINCTRL subsystem.
67292082a88SKen Xue
673ced3ce76SDavid E. Boxconfig IOSF_MBI
674ced3ce76SDavid E. Box	tristate "Intel SoC IOSF Sideband support for SoC platforms"
675ced3ce76SDavid E. Box	depends on PCI
676a7f7f624SMasahiro Yamada	help
677ced3ce76SDavid E. Box	  This option enables sideband register access support for Intel SoC
678ced3ce76SDavid E. Box	  platforms. On these platforms the IOSF sideband is used in lieu of
679ced3ce76SDavid E. Box	  MSR's for some register accesses, mostly but not limited to thermal
680ced3ce76SDavid E. Box	  and power. Drivers may query the availability of this device to
681ced3ce76SDavid E. Box	  determine if they need the sideband in order to work on these
682ced3ce76SDavid E. Box	  platforms. The sideband is available on the following SoC products.
683ced3ce76SDavid E. Box	  This list is not meant to be exclusive.
684ced3ce76SDavid E. Box	   - BayTrail
685ced3ce76SDavid E. Box	   - Braswell
686ced3ce76SDavid E. Box	   - Quark
687ced3ce76SDavid E. Box
688ced3ce76SDavid E. Box	  You should say Y if you are running a kernel on one of these SoC's.
689ced3ce76SDavid E. Box
690ed2226bdSDavid E. Boxconfig IOSF_MBI_DEBUG
691ed2226bdSDavid E. Box	bool "Enable IOSF sideband access through debugfs"
692ed2226bdSDavid E. Box	depends on IOSF_MBI && DEBUG_FS
693a7f7f624SMasahiro Yamada	help
694ed2226bdSDavid E. Box	  Select this option to expose the IOSF sideband access registers (MCR,
695ed2226bdSDavid E. Box	  MDR, MCRX) through debugfs to write and read register information from
696ed2226bdSDavid E. Box	  different units on the SoC. This is most useful for obtaining device
697ed2226bdSDavid E. Box	  state information for debug and analysis. As this is a general access
698ed2226bdSDavid E. Box	  mechanism, users of this option would have specific knowledge of the
699ed2226bdSDavid E. Box	  device they want to access.
700ed2226bdSDavid E. Box
701ed2226bdSDavid E. Box	  If you don't require the option or are in doubt, say N.
702ed2226bdSDavid E. Box
703c5c606d9SRavikiran G Thirumalaiconfig X86_RDC321X
704c5c606d9SRavikiran G Thirumalai	bool "RDC R-321x SoC"
705506f1d07SSam Ravnborg	depends on X86_32
706c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
707c5c606d9SRavikiran G Thirumalai	select M486
708c5c606d9SRavikiran G Thirumalai	select X86_REBOOTFIXUPS
709a7f7f624SMasahiro Yamada	help
710c5c606d9SRavikiran G Thirumalai	  This option is needed for RDC R-321x system-on-chip, also known
711c5c606d9SRavikiran G Thirumalai	  as R-8610-(G).
712c5c606d9SRavikiran G Thirumalai	  If you don't have one of these chips, you should say N here.
713c5c606d9SRavikiran G Thirumalai
714e0c7ae37SIngo Molnarconfig X86_32_NON_STANDARD
7159c398017SIngo Molnar	bool "Support non-standard 32-bit SMP architectures"
7169c398017SIngo Molnar	depends on X86_32 && SMP
717c5c606d9SRavikiran G Thirumalai	depends on X86_EXTENDED_PLATFORM
718a7f7f624SMasahiro Yamada	help
719b5660ba7SH. Peter Anvin	  This option compiles in the bigsmp and STA2X11 default
720b5660ba7SH. Peter Anvin	  subarchitectures.  It is intended for a generic binary
721b5660ba7SH. Peter Anvin	  kernel. If you select them all, kernel will probe it one by
722b5660ba7SH. Peter Anvin	  one and will fallback to default.
723d49c4288SYinghai Lu
724c5c606d9SRavikiran G Thirumalai# Alphabetically sorted list of Non standard 32 bit platforms
725d49c4288SYinghai Lu
726d949f36fSLinus Torvaldsconfig X86_SUPPORTS_MEMORY_FAILURE
7276fc108a0SJan Beulich	def_bool y
728d949f36fSLinus Torvalds	# MCE code calls memory_failure():
729d949f36fSLinus Torvalds	depends on X86_MCE
730d949f36fSLinus Torvalds	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
731d949f36fSLinus Torvalds	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
732d949f36fSLinus Torvalds	depends on X86_64 || !SPARSEMEM
733d949f36fSLinus Torvalds	select ARCH_SUPPORTS_MEMORY_FAILURE
734d949f36fSLinus Torvalds
73583125a3aSAlessandro Rubiniconfig STA2X11
73683125a3aSAlessandro Rubini	bool "STA2X11 Companion Chip Support"
73783125a3aSAlessandro Rubini	depends on X86_32_NON_STANDARD && PCI
73883125a3aSAlessandro Rubini	select SWIOTLB
73983125a3aSAlessandro Rubini	select MFD_STA2X11
7400145071bSLinus Walleij	select GPIOLIB
741a7f7f624SMasahiro Yamada	help
74283125a3aSAlessandro Rubini	  This adds support for boards based on the STA2X11 IO-Hub,
74383125a3aSAlessandro Rubini	  a.k.a. "ConneXt". The chip is used in place of the standard
74483125a3aSAlessandro Rubini	  PC chipset, so all "standard" peripherals are missing. If this
74583125a3aSAlessandro Rubini	  option is selected the kernel will still be able to boot on
74683125a3aSAlessandro Rubini	  standard PC machines.
74783125a3aSAlessandro Rubini
74882148d1dSShérabconfig X86_32_IRIS
74982148d1dSShérab	tristate "Eurobraille/Iris poweroff module"
75082148d1dSShérab	depends on X86_32
751a7f7f624SMasahiro Yamada	help
75282148d1dSShérab	  The Iris machines from EuroBraille do not have APM or ACPI support
75382148d1dSShérab	  to shut themselves down properly.  A special I/O sequence is
75482148d1dSShérab	  needed to do so, which is what this module does at
75582148d1dSShérab	  kernel shutdown.
75682148d1dSShérab
75782148d1dSShérab	  This is only for Iris machines from EuroBraille.
75882148d1dSShérab
75982148d1dSShérab	  If unused, say N.
76082148d1dSShérab
761ae1e9130SIngo Molnarconfig SCHED_OMIT_FRAME_POINTER
7623c2362e6SHarvey Harrison	def_bool y
7633c2362e6SHarvey Harrison	prompt "Single-depth WCHAN output"
764a87d0914SKen Chen	depends on X86
765a7f7f624SMasahiro Yamada	help
766506f1d07SSam Ravnborg	  Calculate simpler /proc/<PID>/wchan values. If this option
767506f1d07SSam Ravnborg	  is disabled then wchan values will recurse back to the
768506f1d07SSam Ravnborg	  caller function. This provides more accurate wchan values,
769506f1d07SSam Ravnborg	  at the expense of slightly more scheduling overhead.
770506f1d07SSam Ravnborg
771506f1d07SSam Ravnborg	  If in doubt, say "Y".
772506f1d07SSam Ravnborg
7736276a074SBorislav Petkovmenuconfig HYPERVISOR_GUEST
7746276a074SBorislav Petkov	bool "Linux guest support"
775a7f7f624SMasahiro Yamada	help
7766276a074SBorislav Petkov	  Say Y here to enable options for running Linux under various hyper-
7776276a074SBorislav Petkov	  visors. This option enables basic hypervisor detection and platform
7786276a074SBorislav Petkov	  setup.
779506f1d07SSam Ravnborg
7806276a074SBorislav Petkov	  If you say N, all options in this submenu will be skipped and
7816276a074SBorislav Petkov	  disabled, and Linux guest support won't be built in.
782506f1d07SSam Ravnborg
7836276a074SBorislav Petkovif HYPERVISOR_GUEST
784506f1d07SSam Ravnborg
785e61bd94aSEduardo Pereira Habkostconfig PARAVIRT
786e61bd94aSEduardo Pereira Habkost	bool "Enable paravirtualization code"
787a0e2bf7cSJuergen Gross	depends on HAVE_STATIC_CALL
788a7f7f624SMasahiro Yamada	help
789e61bd94aSEduardo Pereira Habkost	  This changes the kernel so it can modify itself when it is run
790e61bd94aSEduardo Pereira Habkost	  under a hypervisor, potentially improving performance significantly
791e61bd94aSEduardo Pereira Habkost	  over full virtualization.  However, when run without a hypervisor
792e61bd94aSEduardo Pereira Habkost	  the kernel is theoretically slower and slightly larger.
793e61bd94aSEduardo Pereira Habkost
794c00a280aSJuergen Grossconfig PARAVIRT_XXL
795c00a280aSJuergen Gross	bool
796c00a280aSJuergen Gross
7976276a074SBorislav Petkovconfig PARAVIRT_DEBUG
7986276a074SBorislav Petkov	bool "paravirt-ops debugging"
7996276a074SBorislav Petkov	depends on PARAVIRT && DEBUG_KERNEL
800a7f7f624SMasahiro Yamada	help
8016276a074SBorislav Petkov	  Enable to debug paravirt_ops internals.  Specifically, BUG if
8026276a074SBorislav Petkov	  a paravirt_op is missing when it is called.
8036276a074SBorislav Petkov
804b4ecc126SJeremy Fitzhardingeconfig PARAVIRT_SPINLOCKS
805b4ecc126SJeremy Fitzhardinge	bool "Paravirtualization layer for spinlocks"
8066ea30386SKees Cook	depends on PARAVIRT && SMP
807a7f7f624SMasahiro Yamada	help
808b4ecc126SJeremy Fitzhardinge	  Paravirtualized spinlocks allow a pvops backend to replace the
809b4ecc126SJeremy Fitzhardinge	  spinlock implementation with something virtualization-friendly
810b4ecc126SJeremy Fitzhardinge	  (for example, block the virtual CPU rather than spinning).
811b4ecc126SJeremy Fitzhardinge
8124c4e4f61SRaghavendra K T	  It has a minimal impact on native kernels and gives a nice performance
8134c4e4f61SRaghavendra K T	  benefit on paravirtualized KVM / Xen kernels.
814b4ecc126SJeremy Fitzhardinge
8154c4e4f61SRaghavendra K T	  If you are unsure how to answer this question, answer Y.
816b4ecc126SJeremy Fitzhardinge
817ecca2502SZhao Yakuiconfig X86_HV_CALLBACK_VECTOR
818ecca2502SZhao Yakui	def_bool n
819ecca2502SZhao Yakui
8206276a074SBorislav Petkovsource "arch/x86/xen/Kconfig"
8216276a074SBorislav Petkov
8226276a074SBorislav Petkovconfig KVM_GUEST
8236276a074SBorislav Petkov	bool "KVM Guest support (including kvmclock)"
8246276a074SBorislav Petkov	depends on PARAVIRT
8256276a074SBorislav Petkov	select PARAVIRT_CLOCK
826a1c4423bSMarcelo Tosatti	select ARCH_CPUIDLE_HALTPOLL
827b1d40575SVitaly Kuznetsov	select X86_HV_CALLBACK_VECTOR
8286276a074SBorislav Petkov	default y
829a7f7f624SMasahiro Yamada	help
8306276a074SBorislav Petkov	  This option enables various optimizations for running under the KVM
8316276a074SBorislav Petkov	  hypervisor. It includes a paravirtualized clock, so that instead
8326276a074SBorislav Petkov	  of relying on a PIT (or probably other) emulation by the
8336276a074SBorislav Petkov	  underlying device model, the host provides the guest with
8346276a074SBorislav Petkov	  timing infrastructure such as time of day, and system time
8356276a074SBorislav Petkov
836a1c4423bSMarcelo Tosatticonfig ARCH_CPUIDLE_HALTPOLL
837a1c4423bSMarcelo Tosatti	def_bool n
838a1c4423bSMarcelo Tosatti	prompt "Disable host haltpoll when loading haltpoll driver"
839a1c4423bSMarcelo Tosatti	help
840a1c4423bSMarcelo Tosatti	  If virtualized under KVM, disable host haltpoll.
841a1c4423bSMarcelo Tosatti
8427733607fSMaran Wilsonconfig PVH
8437733607fSMaran Wilson	bool "Support for running PVH guests"
844a7f7f624SMasahiro Yamada	help
8457733607fSMaran Wilson	  This option enables the PVH entry point for guest virtual machines
8467733607fSMaran Wilson	  as specified in the x86/HVM direct boot ABI.
8477733607fSMaran Wilson
8486276a074SBorislav Petkovconfig PARAVIRT_TIME_ACCOUNTING
8496276a074SBorislav Petkov	bool "Paravirtual steal time accounting"
8506276a074SBorislav Petkov	depends on PARAVIRT
851a7f7f624SMasahiro Yamada	help
8526276a074SBorislav Petkov	  Select this option to enable fine granularity task steal time
8536276a074SBorislav Petkov	  accounting. Time spent executing other tasks in parallel with
8546276a074SBorislav Petkov	  the current vCPU is discounted from the vCPU power. To account for
8556276a074SBorislav Petkov	  that, there can be a small performance impact.
8566276a074SBorislav Petkov
8576276a074SBorislav Petkov	  If in doubt, say N here.
8586276a074SBorislav Petkov
8597af192c9SGerd Hoffmannconfig PARAVIRT_CLOCK
8607af192c9SGerd Hoffmann	bool
8617af192c9SGerd Hoffmann
8624a362601SJan Kiszkaconfig JAILHOUSE_GUEST
8634a362601SJan Kiszka	bool "Jailhouse non-root cell support"
864abde587bSArnd Bergmann	depends on X86_64 && PCI
86587e65d05SJan Kiszka	select X86_PM_TIMER
866a7f7f624SMasahiro Yamada	help
8674a362601SJan Kiszka	  This option allows to run Linux as guest in a Jailhouse non-root
8684a362601SJan Kiszka	  cell. You can leave this option disabled if you only want to start
8694a362601SJan Kiszka	  Jailhouse and run Linux afterwards in the root cell.
8704a362601SJan Kiszka
871ec7972c9SZhao Yakuiconfig ACRN_GUEST
872ec7972c9SZhao Yakui	bool "ACRN Guest support"
873ec7972c9SZhao Yakui	depends on X86_64
874498ad393SZhao Yakui	select X86_HV_CALLBACK_VECTOR
875ec7972c9SZhao Yakui	help
876ec7972c9SZhao Yakui	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
877ec7972c9SZhao Yakui	  a flexible, lightweight reference open-source hypervisor, built with
878ec7972c9SZhao Yakui	  real-time and safety-criticality in mind. It is built for embedded
879ec7972c9SZhao Yakui	  IOT with small footprint and real-time features. More details can be
880ec7972c9SZhao Yakui	  found in https://projectacrn.org/.
881ec7972c9SZhao Yakui
88259bd54a8SKuppuswamy Sathyanarayananconfig INTEL_TDX_GUEST
88359bd54a8SKuppuswamy Sathyanarayanan	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
88459bd54a8SKuppuswamy Sathyanarayanan	depends on X86_64 && CPU_SUP_INTEL
88559bd54a8SKuppuswamy Sathyanarayanan	depends on X86_X2APIC
88641394e33SKirill A. Shutemov	select ARCH_HAS_CC_PLATFORM
887968b4931SKirill A. Shutemov	select X86_MEM_ENCRYPT
88877a512e3SSean Christopherson	select X86_MCE
88959bd54a8SKuppuswamy Sathyanarayanan	help
89059bd54a8SKuppuswamy Sathyanarayanan	  Support running as a guest under Intel TDX.  Without this support,
89159bd54a8SKuppuswamy Sathyanarayanan	  the guest kernel can not boot or run under TDX.
89259bd54a8SKuppuswamy Sathyanarayanan	  TDX includes memory encryption and integrity capabilities
89359bd54a8SKuppuswamy Sathyanarayanan	  which protect the confidentiality and integrity of guest
89459bd54a8SKuppuswamy Sathyanarayanan	  memory contents and CPU state. TDX guests are protected from
89559bd54a8SKuppuswamy Sathyanarayanan	  some attacks from the VMM.
89659bd54a8SKuppuswamy Sathyanarayanan
8976276a074SBorislav Petkovendif # HYPERVISOR_GUEST
89897349135SJeremy Fitzhardinge
899506f1d07SSam Ravnborgsource "arch/x86/Kconfig.cpu"
900506f1d07SSam Ravnborg
901506f1d07SSam Ravnborgconfig HPET_TIMER
9023c2362e6SHarvey Harrison	def_bool X86_64
903506f1d07SSam Ravnborg	prompt "HPET Timer Support" if X86_32
904a7f7f624SMasahiro Yamada	help
905506f1d07SSam Ravnborg	  Use the IA-PC HPET (High Precision Event Timer) to manage
906506f1d07SSam Ravnborg	  time in preference to the PIT and RTC, if a HPET is
907506f1d07SSam Ravnborg	  present.
908506f1d07SSam Ravnborg	  HPET is the next generation timer replacing legacy 8254s.
909506f1d07SSam Ravnborg	  The HPET provides a stable time base on SMP
910506f1d07SSam Ravnborg	  systems, unlike the TSC, but it is more expensive to access,
9114e7f9df2SMichael S. Tsirkin	  as it is off-chip.  The interface used is documented
9124e7f9df2SMichael S. Tsirkin	  in the HPET spec, revision 1.
913506f1d07SSam Ravnborg
914506f1d07SSam Ravnborg	  You can safely choose Y here.  However, HPET will only be
915506f1d07SSam Ravnborg	  activated if the platform and the BIOS support this feature.
916506f1d07SSam Ravnborg	  Otherwise the 8254 will be used for timing services.
917506f1d07SSam Ravnborg
918506f1d07SSam Ravnborg	  Choose N to continue using the legacy 8254 timer.
919506f1d07SSam Ravnborg
920506f1d07SSam Ravnborgconfig HPET_EMULATE_RTC
9213c2362e6SHarvey Harrison	def_bool y
9223228e1dcSAnand K Mistry	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
923506f1d07SSam Ravnborg
9246a108a14SDavid Rientjes# Mark as expert because too many people got it wrong.
925506f1d07SSam Ravnborg# The code disables itself when not needed.
9267ae9392cSThomas Petazzoniconfig DMI
9277ae9392cSThomas Petazzoni	default y
928cf074402SArd Biesheuvel	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
9296a108a14SDavid Rientjes	bool "Enable DMI scanning" if EXPERT
930a7f7f624SMasahiro Yamada	help
9317ae9392cSThomas Petazzoni	  Enabled scanning of DMI to identify machine quirks. Say Y
9327ae9392cSThomas Petazzoni	  here unless you have verified that your setup is not
9337ae9392cSThomas Petazzoni	  affected by entries in the DMI blacklist. Required by PNP
9347ae9392cSThomas Petazzoni	  BIOS code.
9357ae9392cSThomas Petazzoni
936506f1d07SSam Ravnborgconfig GART_IOMMU
93738901f1cSAndi Kleen	bool "Old AMD GART IOMMU support"
9382f9237d4SChristoph Hellwig	select DMA_OPS
939a4ce5a48SChristoph Hellwig	select IOMMU_HELPER
940506f1d07SSam Ravnborg	select SWIOTLB
94123ac4ae8SAndreas Herrmann	depends on X86_64 && PCI && AMD_NB
942a7f7f624SMasahiro Yamada	help
943ced3c42cSIngo Molnar	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
944ced3c42cSIngo Molnar	  GART based hardware IOMMUs.
945ced3c42cSIngo Molnar
946ced3c42cSIngo Molnar	  The GART supports full DMA access for devices with 32-bit access
947ced3c42cSIngo Molnar	  limitations, on systems with more than 3 GB. This is usually needed
948ced3c42cSIngo Molnar	  for USB, sound, many IDE/SATA chipsets and some other devices.
949ced3c42cSIngo Molnar
950ced3c42cSIngo Molnar	  Newer systems typically have a modern AMD IOMMU, supported via
951ced3c42cSIngo Molnar	  the CONFIG_AMD_IOMMU=y config option.
952ced3c42cSIngo Molnar
953ced3c42cSIngo Molnar	  In normal configurations this driver is only active when needed:
954ced3c42cSIngo Molnar	  there's more than 3 GB of memory and the system contains a
955ced3c42cSIngo Molnar	  32-bit limited device.
956ced3c42cSIngo Molnar
957ced3c42cSIngo Molnar	  If unsure, say Y.
958506f1d07SSam Ravnborg
9598b766b0fSMichal Suchanekconfig BOOT_VESA_SUPPORT
9608b766b0fSMichal Suchanek	bool
9618b766b0fSMichal Suchanek	help
9628b766b0fSMichal Suchanek	  If true, at least one selected framebuffer driver can take advantage
9638b766b0fSMichal Suchanek	  of VESA video modes set at an early boot stage via the vga= parameter.
9648b766b0fSMichal Suchanek
9651184dc2fSMike Travisconfig MAXSMP
966ddb0c5a6SSamuel Thibault	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
9676ea30386SKees Cook	depends on X86_64 && SMP && DEBUG_KERNEL
96836f5101aSMike Travis	select CPUMASK_OFFSTACK
969a7f7f624SMasahiro Yamada	help
970ddb0c5a6SSamuel Thibault	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
9711184dc2fSMike Travis	  If unsure, say N.
972506f1d07SSam Ravnborg
973aec6487eSIngo Molnar#
974aec6487eSIngo Molnar# The maximum number of CPUs supported:
975aec6487eSIngo Molnar#
976aec6487eSIngo Molnar# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
977aec6487eSIngo Molnar# and which can be configured interactively in the
978aec6487eSIngo Molnar# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
979aec6487eSIngo Molnar#
980aec6487eSIngo Molnar# The ranges are different on 32-bit and 64-bit kernels, depending on
981aec6487eSIngo Molnar# hardware capabilities and scalability features of the kernel.
982aec6487eSIngo Molnar#
983aec6487eSIngo Molnar# ( If MAXSMP is enabled we just use the highest possible value and disable
984aec6487eSIngo Molnar#   interactive configuration. )
985aec6487eSIngo Molnar#
986a0d0bb4dSRandy Dunlap
987aec6487eSIngo Molnarconfig NR_CPUS_RANGE_BEGIN
988a0d0bb4dSRandy Dunlap	int
989aec6487eSIngo Molnar	default NR_CPUS_RANGE_END if MAXSMP
990a0d0bb4dSRandy Dunlap	default    1 if !SMP
991a0d0bb4dSRandy Dunlap	default    2
992a0d0bb4dSRandy Dunlap
993aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
994a0d0bb4dSRandy Dunlap	int
995a0d0bb4dSRandy Dunlap	depends on X86_32
996aec6487eSIngo Molnar	default   64 if  SMP &&  X86_BIGSMP
997aec6487eSIngo Molnar	default    8 if  SMP && !X86_BIGSMP
998a0d0bb4dSRandy Dunlap	default    1 if !SMP
999a0d0bb4dSRandy Dunlap
1000aec6487eSIngo Molnarconfig NR_CPUS_RANGE_END
1001a0d0bb4dSRandy Dunlap	int
1002a0d0bb4dSRandy Dunlap	depends on X86_64
10031edae1aeSScott Wood	default 8192 if  SMP && CPUMASK_OFFSTACK
10041edae1aeSScott Wood	default  512 if  SMP && !CPUMASK_OFFSTACK
1005a0d0bb4dSRandy Dunlap	default    1 if !SMP
1006aec6487eSIngo Molnar
1007aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1008aec6487eSIngo Molnar	int
1009aec6487eSIngo Molnar	depends on X86_32
1010aec6487eSIngo Molnar	default   32 if  X86_BIGSMP
1011aec6487eSIngo Molnar	default    8 if  SMP
1012aec6487eSIngo Molnar	default    1 if !SMP
1013aec6487eSIngo Molnar
1014aec6487eSIngo Molnarconfig NR_CPUS_DEFAULT
1015aec6487eSIngo Molnar	int
1016aec6487eSIngo Molnar	depends on X86_64
1017a0d0bb4dSRandy Dunlap	default 8192 if  MAXSMP
1018a0d0bb4dSRandy Dunlap	default   64 if  SMP
1019aec6487eSIngo Molnar	default    1 if !SMP
1020a0d0bb4dSRandy Dunlap
1021506f1d07SSam Ravnborgconfig NR_CPUS
102236f5101aSMike Travis	int "Maximum number of CPUs" if SMP && !MAXSMP
1023aec6487eSIngo Molnar	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1024aec6487eSIngo Molnar	default NR_CPUS_DEFAULT
1025a7f7f624SMasahiro Yamada	help
1026506f1d07SSam Ravnborg	  This allows you to specify the maximum number of CPUs which this
1027bb61ccc7SJosh Boyer	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1028cad14bb9SKirill A. Shutemov	  supported value is 8192, otherwise the maximum value is 512.  The
1029506f1d07SSam Ravnborg	  minimum value which makes sense is 2.
1030506f1d07SSam Ravnborg
1031aec6487eSIngo Molnar	  This is purely to save memory: each supported CPU adds about 8KB
1032aec6487eSIngo Molnar	  to the kernel image.
1033506f1d07SSam Ravnborg
103466558b73STim Chenconfig SCHED_CLUSTER
103566558b73STim Chen	bool "Cluster scheduler support"
103666558b73STim Chen	depends on SMP
103766558b73STim Chen	default y
103866558b73STim Chen	help
103966558b73STim Chen	  Cluster scheduler support improves the CPU scheduler's decision
104066558b73STim Chen	  making when dealing with machines that have clusters of CPUs.
104166558b73STim Chen	  Cluster usually means a couple of CPUs which are placed closely
104266558b73STim Chen	  by sharing mid-level caches, last-level cache tags or internal
104366558b73STim Chen	  busses.
104466558b73STim Chen
1045506f1d07SSam Ravnborgconfig SCHED_SMT
1046dbe73364SThomas Gleixner	def_bool y if SMP
1047506f1d07SSam Ravnborg
1048506f1d07SSam Ravnborgconfig SCHED_MC
10493c2362e6SHarvey Harrison	def_bool y
10503c2362e6SHarvey Harrison	prompt "Multi-core scheduler support"
1051c8e56d20SBorislav Petkov	depends on SMP
1052a7f7f624SMasahiro Yamada	help
1053506f1d07SSam Ravnborg	  Multi-core scheduler support improves the CPU scheduler's decision
1054506f1d07SSam Ravnborg	  making when dealing with multi-core CPU chips at a cost of slightly
1055506f1d07SSam Ravnborg	  increased overhead in some places. If unsure say N here.
1056506f1d07SSam Ravnborg
1057de966cf4STim Chenconfig SCHED_MC_PRIO
1058de966cf4STim Chen	bool "CPU core priorities scheduler support"
10590a21fc12SIngo Molnar	depends on SCHED_MC && CPU_SUP_INTEL
10600a21fc12SIngo Molnar	select X86_INTEL_PSTATE
10610a21fc12SIngo Molnar	select CPU_FREQ
1062de966cf4STim Chen	default y
1063a7f7f624SMasahiro Yamada	help
1064de966cf4STim Chen	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1065de966cf4STim Chen	  core ordering determined at manufacturing time, which allows
1066de966cf4STim Chen	  certain cores to reach higher turbo frequencies (when running
1067de966cf4STim Chen	  single threaded workloads) than others.
1068de966cf4STim Chen
1069de966cf4STim Chen	  Enabling this kernel feature teaches the scheduler about
1070de966cf4STim Chen	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1071de966cf4STim Chen	  scheduler's CPU selection logic accordingly, so that higher
1072de966cf4STim Chen	  overall system performance can be achieved.
1073de966cf4STim Chen
1074de966cf4STim Chen	  This feature will have no effect on CPUs without this feature.
1075de966cf4STim Chen
1076de966cf4STim Chen	  If unsure say Y here.
10775e76b2abSTim Chen
107830b8b006SThomas Gleixnerconfig UP_LATE_INIT
107930b8b006SThomas Gleixner	def_bool y
1080ba360f88SThomas Gleixner	depends on !SMP && X86_LOCAL_APIC
108130b8b006SThomas Gleixner
1082506f1d07SSam Ravnborgconfig X86_UP_APIC
108350849eefSJan Beulich	bool "Local APIC support on uniprocessors" if !PCI_MSI
108450849eefSJan Beulich	default PCI_MSI
108538a1dfdaSBryan O'Donoghue	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1086a7f7f624SMasahiro Yamada	help
1087506f1d07SSam Ravnborg	  A local APIC (Advanced Programmable Interrupt Controller) is an
1088506f1d07SSam Ravnborg	  integrated interrupt controller in the CPU. If you have a single-CPU
1089506f1d07SSam Ravnborg	  system which has a processor with a local APIC, you can say Y here to
1090506f1d07SSam Ravnborg	  enable and use it. If you say Y here even though your machine doesn't
1091506f1d07SSam Ravnborg	  have a local APIC, then the kernel will still run with no slowdown at
1092506f1d07SSam Ravnborg	  all. The local APIC supports CPU-generated self-interrupts (timer,
1093506f1d07SSam Ravnborg	  performance counters), and the NMI watchdog which detects hard
1094506f1d07SSam Ravnborg	  lockups.
1095506f1d07SSam Ravnborg
1096506f1d07SSam Ravnborgconfig X86_UP_IOAPIC
1097506f1d07SSam Ravnborg	bool "IO-APIC support on uniprocessors"
1098506f1d07SSam Ravnborg	depends on X86_UP_APIC
1099a7f7f624SMasahiro Yamada	help
1100506f1d07SSam Ravnborg	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1101506f1d07SSam Ravnborg	  SMP-capable replacement for PC-style interrupt controllers. Most
1102506f1d07SSam Ravnborg	  SMP systems and many recent uniprocessor systems have one.
1103506f1d07SSam Ravnborg
1104506f1d07SSam Ravnborg	  If you have a single-CPU system with an IO-APIC, you can say Y here
1105506f1d07SSam Ravnborg	  to use it. If you say Y here even though your machine doesn't have
1106506f1d07SSam Ravnborg	  an IO-APIC, then the kernel will still run with no slowdown at all.
1107506f1d07SSam Ravnborg
1108506f1d07SSam Ravnborgconfig X86_LOCAL_APIC
11093c2362e6SHarvey Harrison	def_bool y
11100dbc6078SThomas Petazzoni	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1111b5dc8e6cSJiang Liu	select IRQ_DOMAIN_HIERARCHY
1112506f1d07SSam Ravnborg
1113506f1d07SSam Ravnborgconfig X86_IO_APIC
1114b1da1e71SJan Beulich	def_bool y
1115b1da1e71SJan Beulich	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1116506f1d07SSam Ravnborg
111741b9eb26SStefan Assmannconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
111841b9eb26SStefan Assmann	bool "Reroute for broken boot IRQs"
111941b9eb26SStefan Assmann	depends on X86_IO_APIC
1120a7f7f624SMasahiro Yamada	help
112141b9eb26SStefan Assmann	  This option enables a workaround that fixes a source of
112241b9eb26SStefan Assmann	  spurious interrupts. This is recommended when threaded
112341b9eb26SStefan Assmann	  interrupt handling is used on systems where the generation of
112441b9eb26SStefan Assmann	  superfluous "boot interrupts" cannot be disabled.
112541b9eb26SStefan Assmann
112641b9eb26SStefan Assmann	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
112741b9eb26SStefan Assmann	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
112841b9eb26SStefan Assmann	  kernel does during interrupt handling). On chipsets where this
112941b9eb26SStefan Assmann	  boot IRQ generation cannot be disabled, this workaround keeps
113041b9eb26SStefan Assmann	  the original IRQ line masked so that only the equivalent "boot
113141b9eb26SStefan Assmann	  IRQ" is delivered to the CPUs. The workaround also tells the
113241b9eb26SStefan Assmann	  kernel to set up the IRQ handler on the boot IRQ line. In this
113341b9eb26SStefan Assmann	  way only one interrupt is delivered to the kernel. Otherwise
113441b9eb26SStefan Assmann	  the spurious second interrupt may cause the kernel to bring
113541b9eb26SStefan Assmann	  down (vital) interrupt lines.
113641b9eb26SStefan Assmann
113741b9eb26SStefan Assmann	  Only affects "broken" chipsets. Interrupt sharing may be
113841b9eb26SStefan Assmann	  increased on these systems.
113941b9eb26SStefan Assmann
1140506f1d07SSam Ravnborgconfig X86_MCE
1141bab9bc65SAndi Kleen	bool "Machine Check / overheating reporting"
1142648ed940SChen, Gong	select GENERIC_ALLOCATOR
1143e57dbaf7SBorislav Petkov	default y
1144a7f7f624SMasahiro Yamada	help
1145bab9bc65SAndi Kleen	  Machine Check support allows the processor to notify the
1146bab9bc65SAndi Kleen	  kernel if it detects a problem (e.g. overheating, data corruption).
1147506f1d07SSam Ravnborg	  The action the kernel takes depends on the severity of the problem,
1148bab9bc65SAndi Kleen	  ranging from warning messages to halting the machine.
11494efc0670SAndi Kleen
11505de97c9fSTony Luckconfig X86_MCELOG_LEGACY
11515de97c9fSTony Luck	bool "Support for deprecated /dev/mcelog character device"
11525de97c9fSTony Luck	depends on X86_MCE
1153a7f7f624SMasahiro Yamada	help
11545de97c9fSTony Luck	  Enable support for /dev/mcelog which is needed by the old mcelog
11555de97c9fSTony Luck	  userspace logging daemon. Consider switching to the new generation
11565de97c9fSTony Luck	  rasdaemon solution.
11575de97c9fSTony Luck
1158506f1d07SSam Ravnborgconfig X86_MCE_INTEL
11593c2362e6SHarvey Harrison	def_bool y
11603c2362e6SHarvey Harrison	prompt "Intel MCE features"
1161c1ebf835SAndi Kleen	depends on X86_MCE && X86_LOCAL_APIC
1162a7f7f624SMasahiro Yamada	help
1163506f1d07SSam Ravnborg	  Additional support for intel specific MCE features such as
1164506f1d07SSam Ravnborg	  the thermal monitor.
1165506f1d07SSam Ravnborg
1166506f1d07SSam Ravnborgconfig X86_MCE_AMD
11673c2362e6SHarvey Harrison	def_bool y
11683c2362e6SHarvey Harrison	prompt "AMD MCE features"
1169f5382de9SYazen Ghannam	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1170a7f7f624SMasahiro Yamada	help
1171506f1d07SSam Ravnborg	  Additional support for AMD specific MCE features such as
1172506f1d07SSam Ravnborg	  the DRAM Error Threshold.
1173506f1d07SSam Ravnborg
11744efc0670SAndi Kleenconfig X86_ANCIENT_MCE
11756fc108a0SJan Beulich	bool "Support for old Pentium 5 / WinChip machine checks"
1176c31d9633SAndi Kleen	depends on X86_32 && X86_MCE
1177a7f7f624SMasahiro Yamada	help
11784efc0670SAndi Kleen	  Include support for machine check handling on old Pentium 5 or WinChip
11795065a706SMasanari Iida	  systems. These typically need to be enabled explicitly on the command
11804efc0670SAndi Kleen	  line.
11814efc0670SAndi Kleen
1182b2762686SAndi Kleenconfig X86_MCE_THRESHOLD
1183b2762686SAndi Kleen	depends on X86_MCE_AMD || X86_MCE_INTEL
11846fc108a0SJan Beulich	def_bool y
1185b2762686SAndi Kleen
1186ea149b36SAndi Kleenconfig X86_MCE_INJECT
1187bc8e80d5SBorislav Petkov	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1188ea149b36SAndi Kleen	tristate "Machine check injector support"
1189a7f7f624SMasahiro Yamada	help
1190ea149b36SAndi Kleen	  Provide support for injecting machine checks for testing purposes.
1191ea149b36SAndi Kleen	  If you don't know what a machine check is and you don't do kernel
1192ea149b36SAndi Kleen	  QA it is safe to say n.
1193ea149b36SAndi Kleen
119407dc900eSPeter Zijlstrasource "arch/x86/events/Kconfig"
1195e633c65aSKan Liang
11965aef51c3SAndy Lutomirskiconfig X86_LEGACY_VM86
11971e642812SIngo Molnar	bool "Legacy VM86 support"
1198506f1d07SSam Ravnborg	depends on X86_32
1199a7f7f624SMasahiro Yamada	help
12005aef51c3SAndy Lutomirski	  This option allows user programs to put the CPU into V8086
12015aef51c3SAndy Lutomirski	  mode, which is an 80286-era approximation of 16-bit real mode.
12025aef51c3SAndy Lutomirski
12035aef51c3SAndy Lutomirski	  Some very old versions of X and/or vbetool require this option
12045aef51c3SAndy Lutomirski	  for user mode setting.  Similarly, DOSEMU will use it if
12055aef51c3SAndy Lutomirski	  available to accelerate real mode DOS programs.  However, any
12065aef51c3SAndy Lutomirski	  recent version of DOSEMU, X, or vbetool should be fully
12075aef51c3SAndy Lutomirski	  functional even without kernel VM86 support, as they will all
12081e642812SIngo Molnar	  fall back to software emulation. Nevertheless, if you are using
12091e642812SIngo Molnar	  a 16-bit DOS program where 16-bit performance matters, vm86
12101e642812SIngo Molnar	  mode might be faster than emulation and you might want to
12111e642812SIngo Molnar	  enable this option.
12125aef51c3SAndy Lutomirski
12131e642812SIngo Molnar	  Note that any app that works on a 64-bit kernel is unlikely to
12141e642812SIngo Molnar	  need this option, as 64-bit kernels don't, and can't, support
12151e642812SIngo Molnar	  V8086 mode. This option is also unrelated to 16-bit protected
12161e642812SIngo Molnar	  mode and is not needed to run most 16-bit programs under Wine.
12175aef51c3SAndy Lutomirski
12181e642812SIngo Molnar	  Enabling this option increases the complexity of the kernel
12191e642812SIngo Molnar	  and slows down exception handling a tiny bit.
12205aef51c3SAndy Lutomirski
12211e642812SIngo Molnar	  If unsure, say N here.
12225aef51c3SAndy Lutomirski
12235aef51c3SAndy Lutomirskiconfig VM86
12245aef51c3SAndy Lutomirski	bool
12255aef51c3SAndy Lutomirski	default X86_LEGACY_VM86
122634273f41SH. Peter Anvin
122734273f41SH. Peter Anvinconfig X86_16BIT
122834273f41SH. Peter Anvin	bool "Enable support for 16-bit segments" if EXPERT
122934273f41SH. Peter Anvin	default y
1230a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
1231a7f7f624SMasahiro Yamada	help
123234273f41SH. Peter Anvin	  This option is required by programs like Wine to run 16-bit
123334273f41SH. Peter Anvin	  protected mode legacy code on x86 processors.  Disabling
123434273f41SH. Peter Anvin	  this option saves about 300 bytes on i386, or around 6K text
123534273f41SH. Peter Anvin	  plus 16K runtime memory on x86-64,
123634273f41SH. Peter Anvin
123734273f41SH. Peter Anvinconfig X86_ESPFIX32
123834273f41SH. Peter Anvin	def_bool y
123934273f41SH. Peter Anvin	depends on X86_16BIT && X86_32
1240506f1d07SSam Ravnborg
1241197725deSH. Peter Anvinconfig X86_ESPFIX64
1242197725deSH. Peter Anvin	def_bool y
124334273f41SH. Peter Anvin	depends on X86_16BIT && X86_64
1244506f1d07SSam Ravnborg
12451ad83c85SAndy Lutomirskiconfig X86_VSYSCALL_EMULATION
12461ad83c85SAndy Lutomirski	bool "Enable vsyscall emulation" if EXPERT
12471ad83c85SAndy Lutomirski	default y
12481ad83c85SAndy Lutomirski	depends on X86_64
1249a7f7f624SMasahiro Yamada	help
12501ad83c85SAndy Lutomirski	  This enables emulation of the legacy vsyscall page.  Disabling
12511ad83c85SAndy Lutomirski	  it is roughly equivalent to booting with vsyscall=none, except
12521ad83c85SAndy Lutomirski	  that it will also disable the helpful warning if a program
12531ad83c85SAndy Lutomirski	  tries to use a vsyscall.  With this option set to N, offending
12541ad83c85SAndy Lutomirski	  programs will just segfault, citing addresses of the form
12551ad83c85SAndy Lutomirski	  0xffffffffff600?00.
12561ad83c85SAndy Lutomirski
12571ad83c85SAndy Lutomirski	  This option is required by many programs built before 2013, and
12581ad83c85SAndy Lutomirski	  care should be used even with newer programs if set to N.
12591ad83c85SAndy Lutomirski
12601ad83c85SAndy Lutomirski	  Disabling this option saves about 7K of kernel size and
12611ad83c85SAndy Lutomirski	  possibly 4K of additional runtime pagetable memory.
12621ad83c85SAndy Lutomirski
1263111e7b15SThomas Gleixnerconfig X86_IOPL_IOPERM
1264111e7b15SThomas Gleixner	bool "IOPERM and IOPL Emulation"
1265a24ca997SThomas Gleixner	default y
1266a7f7f624SMasahiro Yamada	help
1267111e7b15SThomas Gleixner	  This enables the ioperm() and iopl() syscalls which are necessary
1268111e7b15SThomas Gleixner	  for legacy applications.
1269111e7b15SThomas Gleixner
1270c8137aceSThomas Gleixner	  Legacy IOPL support is an overbroad mechanism which allows user
1271c8137aceSThomas Gleixner	  space aside of accessing all 65536 I/O ports also to disable
1272c8137aceSThomas Gleixner	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1273c8137aceSThomas Gleixner	  capabilities and permission from potentially active security
1274c8137aceSThomas Gleixner	  modules.
1275c8137aceSThomas Gleixner
1276c8137aceSThomas Gleixner	  The emulation restricts the functionality of the syscall to
1277c8137aceSThomas Gleixner	  only allowing the full range I/O port access, but prevents the
1278a24ca997SThomas Gleixner	  ability to disable interrupts from user space which would be
1279a24ca997SThomas Gleixner	  granted if the hardware IOPL mechanism would be used.
1280c8137aceSThomas Gleixner
1281506f1d07SSam Ravnborgconfig TOSHIBA
1282506f1d07SSam Ravnborg	tristate "Toshiba Laptop support"
1283506f1d07SSam Ravnborg	depends on X86_32
1284a7f7f624SMasahiro Yamada	help
1285506f1d07SSam Ravnborg	  This adds a driver to safely access the System Management Mode of
1286506f1d07SSam Ravnborg	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1287506f1d07SSam Ravnborg	  not work on models with a Phoenix BIOS. The System Management Mode
1288506f1d07SSam Ravnborg	  is used to set the BIOS and power saving options on Toshiba portables.
1289506f1d07SSam Ravnborg
1290506f1d07SSam Ravnborg	  For information on utilities to make use of this driver see the
1291506f1d07SSam Ravnborg	  Toshiba Linux utilities web site at:
1292506f1d07SSam Ravnborg	  <http://www.buzzard.org.uk/toshiba/>.
1293506f1d07SSam Ravnborg
1294506f1d07SSam Ravnborg	  Say Y if you intend to run this kernel on a Toshiba portable.
1295506f1d07SSam Ravnborg	  Say N otherwise.
1296506f1d07SSam Ravnborg
1297506f1d07SSam Ravnborgconfig X86_REBOOTFIXUPS
12989ba16087SJan Beulich	bool "Enable X86 board specific fixups for reboot"
12999ba16087SJan Beulich	depends on X86_32
1300a7f7f624SMasahiro Yamada	help
1301506f1d07SSam Ravnborg	  This enables chipset and/or board specific fixups to be done
1302506f1d07SSam Ravnborg	  in order to get reboot to work correctly. This is only needed on
1303506f1d07SSam Ravnborg	  some combinations of hardware and BIOS. The symptom, for which
1304506f1d07SSam Ravnborg	  this config is intended, is when reboot ends with a stalled/hung
1305506f1d07SSam Ravnborg	  system.
1306506f1d07SSam Ravnborg
1307506f1d07SSam Ravnborg	  Currently, the only fixup is for the Geode machines using
13085e3a77e9SFlorian Fainelli	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1309506f1d07SSam Ravnborg
1310506f1d07SSam Ravnborg	  Say Y if you want to enable the fixup. Currently, it's safe to
1311506f1d07SSam Ravnborg	  enable this option even if you don't need it.
1312506f1d07SSam Ravnborg	  Say N otherwise.
1313506f1d07SSam Ravnborg
1314506f1d07SSam Ravnborgconfig MICROCODE
13159a2bc335SBorislav Petkov	bool "CPU microcode loading support"
13169a2bc335SBorislav Petkov	default y
131780030e3dSBorislav Petkov	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1318a7f7f624SMasahiro Yamada	help
1319506f1d07SSam Ravnborg	  If you say Y here, you will be able to update the microcode on
13205f9c01aaSBorislav Petkov	  Intel and AMD processors. The Intel support is for the IA32 family,
13215f9c01aaSBorislav Petkov	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
13225f9c01aaSBorislav Petkov	  AMD support is for families 0x10 and later. You will obviously need
13235f9c01aaSBorislav Petkov	  the actual microcode binary data itself which is not shipped with
13245f9c01aaSBorislav Petkov	  the Linux kernel.
1325506f1d07SSam Ravnborg
13265f9c01aaSBorislav Petkov	  The preferred method to load microcode from a detached initrd is described
1327*ff61f079SJonathan Corbet	  in Documentation/arch/x86/microcode.rst. For that you need to enable
13285f9c01aaSBorislav Petkov	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
13295f9c01aaSBorislav Petkov	  initrd for microcode blobs.
1330506f1d07SSam Ravnborg
1331c508c46eSBenjamin Gilbert	  In addition, you can build the microcode into the kernel. For that you
1332c508c46eSBenjamin Gilbert	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1333c508c46eSBenjamin Gilbert	  config option.
1334506f1d07SSam Ravnborg
13358d86f390SPeter Orubaconfig MICROCODE_INTEL
1336e43f6e67SBorislav Petkov	bool "Intel microcode loading support"
13379c55d99eSBorislav Petkov	depends on CPU_SUP_INTEL && MICROCODE
13388d86f390SPeter Oruba	default MICROCODE
1339a7f7f624SMasahiro Yamada	help
13408d86f390SPeter Oruba	  This options enables microcode patch loading support for Intel
13418d86f390SPeter Oruba	  processors.
13428d86f390SPeter Oruba
1343b8989db9SAlan	  For the current Intel microcode data package go to
1344b8989db9SAlan	  <https://downloadcenter.intel.com> and search for
1345b8989db9SAlan	  'Linux Processor Microcode Data File'.
13468d86f390SPeter Oruba
134780cc9f10SPeter Orubaconfig MICROCODE_AMD
1348e43f6e67SBorislav Petkov	bool "AMD microcode loading support"
13499c55d99eSBorislav Petkov	depends on CPU_SUP_AMD && MICROCODE
1350a7f7f624SMasahiro Yamada	help
135180cc9f10SPeter Oruba	  If you select this option, microcode patch loading support for AMD
135280cc9f10SPeter Oruba	  processors will be enabled.
135380cc9f10SPeter Oruba
1354a77a94f8SBorislav Petkovconfig MICROCODE_LATE_LOADING
1355a77a94f8SBorislav Petkov	bool "Late microcode loading (DANGEROUS)"
1356c02f48e0SBorislav Petkov	default n
1357506f1d07SSam Ravnborg	depends on MICROCODE
1358a7f7f624SMasahiro Yamada	help
1359a77a94f8SBorislav Petkov	  Loading microcode late, when the system is up and executing instructions
1360a77a94f8SBorislav Petkov	  is a tricky business and should be avoided if possible. Just the sequence
1361a77a94f8SBorislav Petkov	  of synchronizing all cores and SMT threads is one fragile dance which does
1362a77a94f8SBorislav Petkov	  not guarantee that cores might not softlock after the loading. Therefore,
1363a77a94f8SBorislav Petkov	  use this at your own risk. Late loading taints the kernel too.
1364506f1d07SSam Ravnborg
1365506f1d07SSam Ravnborgconfig X86_MSR
1366506f1d07SSam Ravnborg	tristate "/dev/cpu/*/msr - Model-specific register support"
1367a7f7f624SMasahiro Yamada	help
1368506f1d07SSam Ravnborg	  This device gives privileged processes access to the x86
1369506f1d07SSam Ravnborg	  Model-Specific Registers (MSRs).  It is a character device with
1370506f1d07SSam Ravnborg	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1371506f1d07SSam Ravnborg	  MSR accesses are directed to a specific CPU on multi-processor
1372506f1d07SSam Ravnborg	  systems.
1373506f1d07SSam Ravnborg
1374506f1d07SSam Ravnborgconfig X86_CPUID
1375506f1d07SSam Ravnborg	tristate "/dev/cpu/*/cpuid - CPU information support"
1376a7f7f624SMasahiro Yamada	help
1377506f1d07SSam Ravnborg	  This device gives processes access to the x86 CPUID instruction to
1378506f1d07SSam Ravnborg	  be executed on a specific processor.  It is a character device
1379506f1d07SSam Ravnborg	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1380506f1d07SSam Ravnborg	  /dev/cpu/31/cpuid.
1381506f1d07SSam Ravnborg
1382506f1d07SSam Ravnborgchoice
1383506f1d07SSam Ravnborg	prompt "High Memory Support"
13846fc108a0SJan Beulich	default HIGHMEM4G
1385506f1d07SSam Ravnborg	depends on X86_32
1386506f1d07SSam Ravnborg
1387506f1d07SSam Ravnborgconfig NOHIGHMEM
1388506f1d07SSam Ravnborg	bool "off"
1389a7f7f624SMasahiro Yamada	help
1390506f1d07SSam Ravnborg	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1391506f1d07SSam Ravnborg	  However, the address space of 32-bit x86 processors is only 4
1392506f1d07SSam Ravnborg	  Gigabytes large. That means that, if you have a large amount of
1393506f1d07SSam Ravnborg	  physical memory, not all of it can be "permanently mapped" by the
1394506f1d07SSam Ravnborg	  kernel. The physical memory that's not permanently mapped is called
1395506f1d07SSam Ravnborg	  "high memory".
1396506f1d07SSam Ravnborg
1397506f1d07SSam Ravnborg	  If you are compiling a kernel which will never run on a machine with
1398506f1d07SSam Ravnborg	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1399506f1d07SSam Ravnborg	  choice and suitable for most users). This will result in a "3GB/1GB"
1400506f1d07SSam Ravnborg	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1401506f1d07SSam Ravnborg	  space and the remaining part of the 4GB virtual memory space is used
1402506f1d07SSam Ravnborg	  by the kernel to permanently map as much physical memory as
1403506f1d07SSam Ravnborg	  possible.
1404506f1d07SSam Ravnborg
1405506f1d07SSam Ravnborg	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1406506f1d07SSam Ravnborg	  answer "4GB" here.
1407506f1d07SSam Ravnborg
1408506f1d07SSam Ravnborg	  If more than 4 Gigabytes is used then answer "64GB" here. This
1409506f1d07SSam Ravnborg	  selection turns Intel PAE (Physical Address Extension) mode on.
1410506f1d07SSam Ravnborg	  PAE implements 3-level paging on IA32 processors. PAE is fully
1411506f1d07SSam Ravnborg	  supported by Linux, PAE mode is implemented on all recent Intel
1412506f1d07SSam Ravnborg	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1413506f1d07SSam Ravnborg	  then the kernel will not boot on CPUs that don't support PAE!
1414506f1d07SSam Ravnborg
1415506f1d07SSam Ravnborg	  The actual amount of total physical memory will either be
1416506f1d07SSam Ravnborg	  auto detected or can be forced by using a kernel command line option
1417506f1d07SSam Ravnborg	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1418506f1d07SSam Ravnborg	  your boot loader (lilo or loadlin) about how to pass options to the
1419506f1d07SSam Ravnborg	  kernel at boot time.)
1420506f1d07SSam Ravnborg
1421506f1d07SSam Ravnborg	  If unsure, say "off".
1422506f1d07SSam Ravnborg
1423506f1d07SSam Ravnborgconfig HIGHMEM4G
1424506f1d07SSam Ravnborg	bool "4GB"
1425a7f7f624SMasahiro Yamada	help
1426506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and between 1 and 4
1427506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1428506f1d07SSam Ravnborg
1429506f1d07SSam Ravnborgconfig HIGHMEM64G
1430506f1d07SSam Ravnborg	bool "64GB"
1431225bac2dSLukas Bulwahn	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1432506f1d07SSam Ravnborg	select X86_PAE
1433a7f7f624SMasahiro Yamada	help
1434506f1d07SSam Ravnborg	  Select this if you have a 32-bit processor and more than 4
1435506f1d07SSam Ravnborg	  gigabytes of physical RAM.
1436506f1d07SSam Ravnborg
1437506f1d07SSam Ravnborgendchoice
1438506f1d07SSam Ravnborg
1439506f1d07SSam Ravnborgchoice
14406a108a14SDavid Rientjes	prompt "Memory split" if EXPERT
1441506f1d07SSam Ravnborg	default VMSPLIT_3G
1442506f1d07SSam Ravnborg	depends on X86_32
1443a7f7f624SMasahiro Yamada	help
1444506f1d07SSam Ravnborg	  Select the desired split between kernel and user memory.
1445506f1d07SSam Ravnborg
1446506f1d07SSam Ravnborg	  If the address range available to the kernel is less than the
1447506f1d07SSam Ravnborg	  physical memory installed, the remaining memory will be available
1448506f1d07SSam Ravnborg	  as "high memory". Accessing high memory is a little more costly
1449506f1d07SSam Ravnborg	  than low memory, as it needs to be mapped into the kernel first.
1450506f1d07SSam Ravnborg	  Note that increasing the kernel address space limits the range
1451506f1d07SSam Ravnborg	  available to user programs, making the address space there
1452506f1d07SSam Ravnborg	  tighter.  Selecting anything other than the default 3G/1G split
1453506f1d07SSam Ravnborg	  will also likely make your kernel incompatible with binary-only
1454506f1d07SSam Ravnborg	  kernel modules.
1455506f1d07SSam Ravnborg
1456506f1d07SSam Ravnborg	  If you are not absolutely sure what you are doing, leave this
1457506f1d07SSam Ravnborg	  option alone!
1458506f1d07SSam Ravnborg
1459506f1d07SSam Ravnborg	config VMSPLIT_3G
1460506f1d07SSam Ravnborg		bool "3G/1G user/kernel split"
1461506f1d07SSam Ravnborg	config VMSPLIT_3G_OPT
1462506f1d07SSam Ravnborg		depends on !X86_PAE
1463506f1d07SSam Ravnborg		bool "3G/1G user/kernel split (for full 1G low memory)"
1464506f1d07SSam Ravnborg	config VMSPLIT_2G
1465506f1d07SSam Ravnborg		bool "2G/2G user/kernel split"
1466506f1d07SSam Ravnborg	config VMSPLIT_2G_OPT
1467506f1d07SSam Ravnborg		depends on !X86_PAE
1468506f1d07SSam Ravnborg		bool "2G/2G user/kernel split (for full 2G low memory)"
1469506f1d07SSam Ravnborg	config VMSPLIT_1G
1470506f1d07SSam Ravnborg		bool "1G/3G user/kernel split"
1471506f1d07SSam Ravnborgendchoice
1472506f1d07SSam Ravnborg
1473506f1d07SSam Ravnborgconfig PAGE_OFFSET
1474506f1d07SSam Ravnborg	hex
1475506f1d07SSam Ravnborg	default 0xB0000000 if VMSPLIT_3G_OPT
1476506f1d07SSam Ravnborg	default 0x80000000 if VMSPLIT_2G
1477506f1d07SSam Ravnborg	default 0x78000000 if VMSPLIT_2G_OPT
1478506f1d07SSam Ravnborg	default 0x40000000 if VMSPLIT_1G
1479506f1d07SSam Ravnborg	default 0xC0000000
1480506f1d07SSam Ravnborg	depends on X86_32
1481506f1d07SSam Ravnborg
1482506f1d07SSam Ravnborgconfig HIGHMEM
14833c2362e6SHarvey Harrison	def_bool y
1484506f1d07SSam Ravnborg	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1485506f1d07SSam Ravnborg
1486506f1d07SSam Ravnborgconfig X86_PAE
14879ba16087SJan Beulich	bool "PAE (Physical Address Extension) Support"
1488506f1d07SSam Ravnborg	depends on X86_32 && !HIGHMEM4G
1489d4a451d5SChristoph Hellwig	select PHYS_ADDR_T_64BIT
14909d99c712SChristian Melki	select SWIOTLB
1491a7f7f624SMasahiro Yamada	help
1492506f1d07SSam Ravnborg	  PAE is required for NX support, and furthermore enables
1493506f1d07SSam Ravnborg	  larger swapspace support for non-overcommit purposes. It
1494506f1d07SSam Ravnborg	  has the cost of more pagetable lookup overhead, and also
1495506f1d07SSam Ravnborg	  consumes more pagetable space per process.
1496506f1d07SSam Ravnborg
149777ef56e4SKirill A. Shutemovconfig X86_5LEVEL
149877ef56e4SKirill A. Shutemov	bool "Enable 5-level page tables support"
149918ec1eafSKirill A. Shutemov	default y
1500eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
1501162434e7SKirill A. Shutemov	select SPARSEMEM_VMEMMAP
150277ef56e4SKirill A. Shutemov	depends on X86_64
1503a7f7f624SMasahiro Yamada	help
150477ef56e4SKirill A. Shutemov	  5-level paging enables access to larger address space:
150577ef56e4SKirill A. Shutemov	  up to 128 PiB of virtual address space and 4 PiB of
150677ef56e4SKirill A. Shutemov	  physical address space.
150777ef56e4SKirill A. Shutemov
150877ef56e4SKirill A. Shutemov	  It will be supported by future Intel CPUs.
150977ef56e4SKirill A. Shutemov
15106657fca0SKirill A. Shutemov	  A kernel with the option enabled can be booted on machines that
15116657fca0SKirill A. Shutemov	  support 4- or 5-level paging.
151277ef56e4SKirill A. Shutemov
1513*ff61f079SJonathan Corbet	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
151477ef56e4SKirill A. Shutemov	  information.
151577ef56e4SKirill A. Shutemov
151677ef56e4SKirill A. Shutemov	  Say N if unsure.
151777ef56e4SKirill A. Shutemov
151810971ab2SIngo Molnarconfig X86_DIRECT_GBPAGES
1519e5008abeSLuis R. Rodriguez	def_bool y
15202e1da13fSVlastimil Babka	depends on X86_64
1521a7f7f624SMasahiro Yamada	help
152210971ab2SIngo Molnar	  Certain kernel features effectively disable kernel
152310971ab2SIngo Molnar	  linear 1 GB mappings (even if the CPU otherwise
152410971ab2SIngo Molnar	  supports them), so don't confuse the user by printing
152510971ab2SIngo Molnar	  that we have them enabled.
15269e899816SNick Piggin
15275c280cf6SThomas Gleixnerconfig X86_CPA_STATISTICS
15285c280cf6SThomas Gleixner	bool "Enable statistic for Change Page Attribute"
15295c280cf6SThomas Gleixner	depends on DEBUG_FS
1530a7f7f624SMasahiro Yamada	help
1531b75baaf3SIngo Molnar	  Expose statistics about the Change Page Attribute mechanism, which
1532a943245aSColin Ian King	  helps to determine the effectiveness of preserving large and huge
15335c280cf6SThomas Gleixner	  page mappings when mapping protections are changed.
15345c280cf6SThomas Gleixner
153520f07a04SKirill A. Shutemovconfig X86_MEM_ENCRYPT
153620f07a04SKirill A. Shutemov	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
153720f07a04SKirill A. Shutemov	select DYNAMIC_PHYSICAL_MASK
153820f07a04SKirill A. Shutemov	def_bool n
153920f07a04SKirill A. Shutemov
15407744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT
15417744ccdbSTom Lendacky	bool "AMD Secure Memory Encryption (SME) support"
15427744ccdbSTom Lendacky	depends on X86_64 && CPU_SUP_AMD
154382fef0adSDavid Rientjes	select DMA_COHERENT_POOL
1544ce9084baSArd Biesheuvel	select ARCH_USE_MEMREMAP_PROT
1545597cfe48SJoerg Roedel	select INSTRUCTION_DECODER
1546aa5a4611STom Lendacky	select ARCH_HAS_CC_PLATFORM
154720f07a04SKirill A. Shutemov	select X86_MEM_ENCRYPT
1548a7f7f624SMasahiro Yamada	help
15497744ccdbSTom Lendacky	  Say yes to enable support for the encryption of system memory.
15507744ccdbSTom Lendacky	  This requires an AMD processor that supports Secure Memory
15517744ccdbSTom Lendacky	  Encryption (SME).
15527744ccdbSTom Lendacky
15537744ccdbSTom Lendackyconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
15547744ccdbSTom Lendacky	bool "Activate AMD Secure Memory Encryption (SME) by default"
15557744ccdbSTom Lendacky	depends on AMD_MEM_ENCRYPT
1556a7f7f624SMasahiro Yamada	help
15577744ccdbSTom Lendacky	  Say yes to have system memory encrypted by default if running on
15587744ccdbSTom Lendacky	  an AMD processor that supports Secure Memory Encryption (SME).
15597744ccdbSTom Lendacky
15607744ccdbSTom Lendacky	  If set to Y, then the encryption of system memory can be
15617744ccdbSTom Lendacky	  deactivated with the mem_encrypt=off command line option.
15627744ccdbSTom Lendacky
15637744ccdbSTom Lendacky	  If set to N, then the encryption of system memory can be
15647744ccdbSTom Lendacky	  activated with the mem_encrypt=on command line option.
15657744ccdbSTom Lendacky
1566506f1d07SSam Ravnborg# Common NUMA Features
1567506f1d07SSam Ravnborgconfig NUMA
1568e133f6eaSRandy Dunlap	bool "NUMA Memory Allocation and Scheduler Support"
1569506f1d07SSam Ravnborg	depends on SMP
1570b5660ba7SH. Peter Anvin	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1571b5660ba7SH. Peter Anvin	default y if X86_BIGSMP
15727ecd19cfSKefeng Wang	select USE_PERCPU_NUMA_NODE_ID
1573a7f7f624SMasahiro Yamada	help
1574e133f6eaSRandy Dunlap	  Enable NUMA (Non-Uniform Memory Access) support.
1575fd51b2d7SKOSAKI Motohiro
1576506f1d07SSam Ravnborg	  The kernel will try to allocate memory used by a CPU on the
1577506f1d07SSam Ravnborg	  local memory controller of the CPU and add some more
1578506f1d07SSam Ravnborg	  NUMA awareness to the kernel.
1579506f1d07SSam Ravnborg
1580c280ea5eSIngo Molnar	  For 64-bit this is recommended if the system is Intel Core i7
1581fd51b2d7SKOSAKI Motohiro	  (or later), AMD Opteron, or EM64T NUMA.
1582fd51b2d7SKOSAKI Motohiro
1583b5660ba7SH. Peter Anvin	  For 32-bit this is only needed if you boot a 32-bit
15847cf6c945SDavid Rientjes	  kernel on a 64-bit NUMA platform.
1585fd51b2d7SKOSAKI Motohiro
1586fd51b2d7SKOSAKI Motohiro	  Otherwise, you should say N.
1587506f1d07SSam Ravnborg
1588eec1d4faSHans Rosenfeldconfig AMD_NUMA
15893c2362e6SHarvey Harrison	def_bool y
15903c2362e6SHarvey Harrison	prompt "Old style AMD Opteron NUMA detection"
15915da0ef9aSTejun Heo	depends on X86_64 && NUMA && PCI
1592a7f7f624SMasahiro Yamada	help
1593eec1d4faSHans Rosenfeld	  Enable AMD NUMA node topology detection.  You should say Y here if
1594eec1d4faSHans Rosenfeld	  you have a multi processor AMD system. This uses an old method to
1595eec1d4faSHans Rosenfeld	  read the NUMA configuration directly from the builtin Northbridge
1596eec1d4faSHans Rosenfeld	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1597eec1d4faSHans Rosenfeld	  which also takes priority if both are compiled in.
1598506f1d07SSam Ravnborg
1599506f1d07SSam Ravnborgconfig X86_64_ACPI_NUMA
16003c2362e6SHarvey Harrison	def_bool y
16013c2362e6SHarvey Harrison	prompt "ACPI NUMA detection"
1602506f1d07SSam Ravnborg	depends on X86_64 && NUMA && ACPI && PCI
1603506f1d07SSam Ravnborg	select ACPI_NUMA
1604a7f7f624SMasahiro Yamada	help
1605506f1d07SSam Ravnborg	  Enable ACPI SRAT based node topology detection.
1606506f1d07SSam Ravnborg
1607506f1d07SSam Ravnborgconfig NUMA_EMU
1608506f1d07SSam Ravnborg	bool "NUMA emulation"
16091b7e03efSTejun Heo	depends on NUMA
1610a7f7f624SMasahiro Yamada	help
1611506f1d07SSam Ravnborg	  Enable NUMA emulation. A flat machine will be split
1612506f1d07SSam Ravnborg	  into virtual nodes when booted with "numa=fake=N", where N is the
1613506f1d07SSam Ravnborg	  number of nodes. This is only useful for debugging.
1614506f1d07SSam Ravnborg
1615506f1d07SSam Ravnborgconfig NODES_SHIFT
1616d25e26b6SLinus Torvalds	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
161751591e31SDavid Rientjes	range 1 10
161851591e31SDavid Rientjes	default "10" if MAXSMP
1619506f1d07SSam Ravnborg	default "6" if X86_64
1620506f1d07SSam Ravnborg	default "3"
1621a9ee6cf5SMike Rapoport	depends on NUMA
1622a7f7f624SMasahiro Yamada	help
16231184dc2fSMike Travis	  Specify the maximum number of NUMA Nodes available on the target
1624692105b8SMatt LaPlante	  system.  Increases memory reserved to accommodate various tables.
1625506f1d07SSam Ravnborg
1626506f1d07SSam Ravnborgconfig ARCH_FLATMEM_ENABLE
1627506f1d07SSam Ravnborg	def_bool y
16283b16651fSTejun Heo	depends on X86_32 && !NUMA
1629506f1d07SSam Ravnborg
1630506f1d07SSam Ravnborgconfig ARCH_SPARSEMEM_ENABLE
1631506f1d07SSam Ravnborg	def_bool y
16326ea30386SKees Cook	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1633506f1d07SSam Ravnborg	select SPARSEMEM_STATIC if X86_32
1634506f1d07SSam Ravnborg	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1635506f1d07SSam Ravnborg
16363b16651fSTejun Heoconfig ARCH_SPARSEMEM_DEFAULT
16376ad57f7fSMike Rapoport	def_bool X86_64 || (NUMA && X86_32)
16383b16651fSTejun Heo
1639506f1d07SSam Ravnborgconfig ARCH_SELECT_MEMORY_MODEL
1640506f1d07SSam Ravnborg	def_bool y
16414eda2bc3SDavid Hildenbrand	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1642506f1d07SSam Ravnborg
1643506f1d07SSam Ravnborgconfig ARCH_MEMORY_PROBE
1644a0842b70SToshi Kani	bool "Enable sysfs memory/probe interface"
16455c11f00bSDavid Hildenbrand	depends on MEMORY_HOTPLUG
1646a0842b70SToshi Kani	help
1647a0842b70SToshi Kani	  This option enables a sysfs memory/probe interface for testing.
1648cb1aaebeSMauro Carvalho Chehab	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1649a0842b70SToshi Kani	  If you are unsure how to answer this question, answer N.
1650506f1d07SSam Ravnborg
16513b16651fSTejun Heoconfig ARCH_PROC_KCORE_TEXT
16523b16651fSTejun Heo	def_bool y
16533b16651fSTejun Heo	depends on X86_64 && PROC_KCORE
16543b16651fSTejun Heo
1655a29815a3SAvi Kivityconfig ILLEGAL_POINTER_VALUE
1656a29815a3SAvi Kivity	hex
1657a29815a3SAvi Kivity	default 0 if X86_32
1658a29815a3SAvi Kivity	default 0xdead000000000000 if X86_64
1659a29815a3SAvi Kivity
16607a67832cSDan Williamsconfig X86_PMEM_LEGACY_DEVICE
16617a67832cSDan Williams	bool
16627a67832cSDan Williams
1663ec776ef6SChristoph Hellwigconfig X86_PMEM_LEGACY
16647a67832cSDan Williams	tristate "Support non-standard NVDIMMs and ADR protected memory"
16659f53f9faSDan Williams	depends on PHYS_ADDR_T_64BIT
16669f53f9faSDan Williams	depends on BLK_DEV
16677a67832cSDan Williams	select X86_PMEM_LEGACY_DEVICE
16687b27a862SDan Williams	select NUMA_KEEP_MEMINFO if NUMA
16699f53f9faSDan Williams	select LIBNVDIMM
1670ec776ef6SChristoph Hellwig	help
1671ec776ef6SChristoph Hellwig	  Treat memory marked using the non-standard e820 type of 12 as used
1672ec776ef6SChristoph Hellwig	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1673ec776ef6SChristoph Hellwig	  The kernel will offer these regions to the 'pmem' driver so
1674ec776ef6SChristoph Hellwig	  they can be used for persistent storage.
1675ec776ef6SChristoph Hellwig
1676ec776ef6SChristoph Hellwig	  Say Y if unsure.
1677ec776ef6SChristoph Hellwig
1678506f1d07SSam Ravnborgconfig HIGHPTE
1679506f1d07SSam Ravnborg	bool "Allocate 3rd-level pagetables from highmem"
16806fc108a0SJan Beulich	depends on HIGHMEM
1681a7f7f624SMasahiro Yamada	help
1682506f1d07SSam Ravnborg	  The VM uses one page table entry for each page of physical memory.
1683506f1d07SSam Ravnborg	  For systems with a lot of RAM, this can be wasteful of precious
1684506f1d07SSam Ravnborg	  low memory.  Setting this option will put user-space page table
1685506f1d07SSam Ravnborg	  entries in high memory.
1686506f1d07SSam Ravnborg
16879f077871SJeremy Fitzhardingeconfig X86_CHECK_BIOS_CORRUPTION
16889f077871SJeremy Fitzhardinge	bool "Check for low memory corruption"
1689a7f7f624SMasahiro Yamada	help
16909f077871SJeremy Fitzhardinge	  Periodically check for memory corruption in low memory, which
16919f077871SJeremy Fitzhardinge	  is suspected to be caused by BIOS.  Even when enabled in the
16929f077871SJeremy Fitzhardinge	  configuration, it is disabled at runtime.  Enable it by
16939f077871SJeremy Fitzhardinge	  setting "memory_corruption_check=1" on the kernel command
16949f077871SJeremy Fitzhardinge	  line.  By default it scans the low 64k of memory every 60
16959f077871SJeremy Fitzhardinge	  seconds; see the memory_corruption_check_size and
16969f077871SJeremy Fitzhardinge	  memory_corruption_check_period parameters in
16978c27ceffSMauro Carvalho Chehab	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
16989f077871SJeremy Fitzhardinge
16999f077871SJeremy Fitzhardinge	  When enabled with the default parameters, this option has
17009f077871SJeremy Fitzhardinge	  almost no overhead, as it reserves a relatively small amount
17019f077871SJeremy Fitzhardinge	  of memory and scans it infrequently.  It both detects corruption
17029f077871SJeremy Fitzhardinge	  and prevents it from affecting the running system.
17039f077871SJeremy Fitzhardinge
17049f077871SJeremy Fitzhardinge	  It is, however, intended as a diagnostic tool; if repeatable
17059f077871SJeremy Fitzhardinge	  BIOS-originated corruption always affects the same memory,
17069f077871SJeremy Fitzhardinge	  you can use memmap= to prevent the kernel from using that
17079f077871SJeremy Fitzhardinge	  memory.
17089f077871SJeremy Fitzhardinge
1709c885df50SJeremy Fitzhardingeconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1710c885df50SJeremy Fitzhardinge	bool "Set the default setting of memory_corruption_check"
1711c885df50SJeremy Fitzhardinge	depends on X86_CHECK_BIOS_CORRUPTION
1712c885df50SJeremy Fitzhardinge	default y
1713a7f7f624SMasahiro Yamada	help
1714c885df50SJeremy Fitzhardinge	  Set whether the default state of memory_corruption_check is
1715c885df50SJeremy Fitzhardinge	  on or off.
1716c885df50SJeremy Fitzhardinge
1717506f1d07SSam Ravnborgconfig MATH_EMULATION
1718506f1d07SSam Ravnborg	bool
1719a5b9e5a2SAndy Lutomirski	depends on MODIFY_LDT_SYSCALL
172087d6021bSArnd Bergmann	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1721a7f7f624SMasahiro Yamada	help
1722506f1d07SSam Ravnborg	  Linux can emulate a math coprocessor (used for floating point
1723506f1d07SSam Ravnborg	  operations) if you don't have one. 486DX and Pentium processors have
1724506f1d07SSam Ravnborg	  a math coprocessor built in, 486SX and 386 do not, unless you added
1725506f1d07SSam Ravnborg	  a 487DX or 387, respectively. (The messages during boot time can
1726506f1d07SSam Ravnborg	  give you some hints here ["man dmesg"].) Everyone needs either a
1727506f1d07SSam Ravnborg	  coprocessor or this emulation.
1728506f1d07SSam Ravnborg
1729506f1d07SSam Ravnborg	  If you don't have a math coprocessor, you need to say Y here; if you
1730506f1d07SSam Ravnborg	  say Y here even though you have a coprocessor, the coprocessor will
1731506f1d07SSam Ravnborg	  be used nevertheless. (This behavior can be changed with the kernel
1732506f1d07SSam Ravnborg	  command line option "no387", which comes handy if your coprocessor
1733506f1d07SSam Ravnborg	  is broken. Try "man bootparam" or see the documentation of your boot
1734506f1d07SSam Ravnborg	  loader (lilo or loadlin) about how to pass options to the kernel at
1735506f1d07SSam Ravnborg	  boot time.) This means that it is a good idea to say Y here if you
1736506f1d07SSam Ravnborg	  intend to use this kernel on different machines.
1737506f1d07SSam Ravnborg
1738506f1d07SSam Ravnborg	  More information about the internals of the Linux math coprocessor
1739506f1d07SSam Ravnborg	  emulation can be found in <file:arch/x86/math-emu/README>.
1740506f1d07SSam Ravnborg
1741506f1d07SSam Ravnborg	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1742506f1d07SSam Ravnborg	  kernel, it won't hurt.
1743506f1d07SSam Ravnborg
1744506f1d07SSam Ravnborgconfig MTRR
17456fc108a0SJan Beulich	def_bool y
17466a108a14SDavid Rientjes	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1747a7f7f624SMasahiro Yamada	help
1748506f1d07SSam Ravnborg	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1749506f1d07SSam Ravnborg	  the Memory Type Range Registers (MTRRs) may be used to control
1750506f1d07SSam Ravnborg	  processor access to memory ranges. This is most useful if you have
1751506f1d07SSam Ravnborg	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1752506f1d07SSam Ravnborg	  allows bus write transfers to be combined into a larger transfer
1753506f1d07SSam Ravnborg	  before bursting over the PCI/AGP bus. This can increase performance
1754506f1d07SSam Ravnborg	  of image write operations 2.5 times or more. Saying Y here creates a
1755506f1d07SSam Ravnborg	  /proc/mtrr file which may be used to manipulate your processor's
1756506f1d07SSam Ravnborg	  MTRRs. Typically the X server should use this.
1757506f1d07SSam Ravnborg
1758506f1d07SSam Ravnborg	  This code has a reasonably generic interface so that similar
1759506f1d07SSam Ravnborg	  control registers on other processors can be easily supported
1760506f1d07SSam Ravnborg	  as well:
1761506f1d07SSam Ravnborg
1762506f1d07SSam Ravnborg	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1763506f1d07SSam Ravnborg	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1764506f1d07SSam Ravnborg	  these, the ARRs are used to emulate the MTRRs.
1765506f1d07SSam Ravnborg	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1766506f1d07SSam Ravnborg	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1767506f1d07SSam Ravnborg	  write-combining. All of these processors are supported by this code
1768506f1d07SSam Ravnborg	  and it makes sense to say Y here if you have one of them.
1769506f1d07SSam Ravnborg
1770506f1d07SSam Ravnborg	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1771506f1d07SSam Ravnborg	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1772506f1d07SSam Ravnborg	  can lead to all sorts of problems, so it's good to say Y here.
1773506f1d07SSam Ravnborg
1774506f1d07SSam Ravnborg	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1775506f1d07SSam Ravnborg	  just add about 9 KB to your kernel.
1776506f1d07SSam Ravnborg
1777*ff61f079SJonathan Corbet	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1778506f1d07SSam Ravnborg
177995ffa243SYinghai Luconfig MTRR_SANITIZER
17802ffb3501SYinghai Lu	def_bool y
178195ffa243SYinghai Lu	prompt "MTRR cleanup support"
178295ffa243SYinghai Lu	depends on MTRR
1783a7f7f624SMasahiro Yamada	help
1784aba3728cSThomas Gleixner	  Convert MTRR layout from continuous to discrete, so X drivers can
1785aba3728cSThomas Gleixner	  add writeback entries.
178695ffa243SYinghai Lu
1787aba3728cSThomas Gleixner	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1788692105b8SMatt LaPlante	  The largest mtrr entry size for a continuous block can be set with
1789aba3728cSThomas Gleixner	  mtrr_chunk_size.
179095ffa243SYinghai Lu
17912ffb3501SYinghai Lu	  If unsure, say Y.
179295ffa243SYinghai Lu
179395ffa243SYinghai Luconfig MTRR_SANITIZER_ENABLE_DEFAULT
1794f5098d62SYinghai Lu	int "MTRR cleanup enable value (0-1)"
1795f5098d62SYinghai Lu	range 0 1
1796f5098d62SYinghai Lu	default "0"
179795ffa243SYinghai Lu	depends on MTRR_SANITIZER
1798a7f7f624SMasahiro Yamada	help
1799f5098d62SYinghai Lu	  Enable mtrr cleanup default value
180095ffa243SYinghai Lu
180112031a62SYinghai Luconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
180212031a62SYinghai Lu	int "MTRR cleanup spare reg num (0-7)"
180312031a62SYinghai Lu	range 0 7
180412031a62SYinghai Lu	default "1"
180512031a62SYinghai Lu	depends on MTRR_SANITIZER
1806a7f7f624SMasahiro Yamada	help
180712031a62SYinghai Lu	  mtrr cleanup spare entries default, it can be changed via
1808aba3728cSThomas Gleixner	  mtrr_spare_reg_nr=N on the kernel command line.
180912031a62SYinghai Lu
18102e5d9c85Svenkatesh.pallipadi@intel.comconfig X86_PAT
18116fc108a0SJan Beulich	def_bool y
18126a108a14SDavid Rientjes	prompt "x86 PAT support" if EXPERT
18132a8a2719SIngo Molnar	depends on MTRR
1814a7f7f624SMasahiro Yamada	help
18152e5d9c85Svenkatesh.pallipadi@intel.com	  Use PAT attributes to setup page level cache control.
1816042b78e4SVenki Pallipadi
18172e5d9c85Svenkatesh.pallipadi@intel.com	  PATs are the modern equivalents of MTRRs and are much more
18182e5d9c85Svenkatesh.pallipadi@intel.com	  flexible than MTRRs.
18192e5d9c85Svenkatesh.pallipadi@intel.com
18202e5d9c85Svenkatesh.pallipadi@intel.com	  Say N here if you see bootup problems (boot crash, boot hang,
1821042b78e4SVenki Pallipadi	  spontaneous reboots) or a non-working video driver.
18222e5d9c85Svenkatesh.pallipadi@intel.com
18232e5d9c85Svenkatesh.pallipadi@intel.com	  If unsure, say Y.
18242e5d9c85Svenkatesh.pallipadi@intel.com
182546cf98cdSVenkatesh Pallipadiconfig ARCH_USES_PG_UNCACHED
182646cf98cdSVenkatesh Pallipadi	def_bool y
182746cf98cdSVenkatesh Pallipadi	depends on X86_PAT
182846cf98cdSVenkatesh Pallipadi
1829b971880fSBabu Mogerconfig X86_UMIP
1830796ebc81SRicardo Neri	def_bool y
1831b971880fSBabu Moger	prompt "User Mode Instruction Prevention" if EXPERT
1832a7f7f624SMasahiro Yamada	help
1833b971880fSBabu Moger	  User Mode Instruction Prevention (UMIP) is a security feature in
1834b971880fSBabu Moger	  some x86 processors. If enabled, a general protection fault is
1835b971880fSBabu Moger	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1836b971880fSBabu Moger	  executed in user mode. These instructions unnecessarily expose
1837b971880fSBabu Moger	  information about the hardware state.
1838796ebc81SRicardo Neri
1839796ebc81SRicardo Neri	  The vast majority of applications do not use these instructions.
1840796ebc81SRicardo Neri	  For the very few that do, software emulation is provided in
1841796ebc81SRicardo Neri	  specific cases in protected and virtual-8086 modes. Emulated
1842796ebc81SRicardo Neri	  results are dummy.
1843aa35f896SRicardo Neri
1844156ff4a5SPeter Zijlstraconfig CC_HAS_IBT
1845156ff4a5SPeter Zijlstra	# GCC >= 9 and binutils >= 2.29
1846156ff4a5SPeter Zijlstra	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1847156ff4a5SPeter Zijlstra	# Clang/LLVM >= 14
1848262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1849262448f3SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1850156ff4a5SPeter Zijlstra	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1851262448f3SNathan Chancellor		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1852156ff4a5SPeter Zijlstra		  $(as-instr,endbr64)
1853156ff4a5SPeter Zijlstra
1854156ff4a5SPeter Zijlstraconfig X86_KERNEL_IBT
1855156ff4a5SPeter Zijlstra	prompt "Indirect Branch Tracking"
18564fd5f70cSKees Cook	def_bool y
185703f16cd0SJosh Poimboeuf	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1858f6a2c2b2SNathan Chancellor	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1859f6a2c2b2SNathan Chancellor	depends on !LD_IS_LLD || LLD_VERSION >= 140000
186003f16cd0SJosh Poimboeuf	select OBJTOOL
1861156ff4a5SPeter Zijlstra	help
1862156ff4a5SPeter Zijlstra	  Build the kernel with support for Indirect Branch Tracking, a
1863156ff4a5SPeter Zijlstra	  hardware support course-grain forward-edge Control Flow Integrity
1864156ff4a5SPeter Zijlstra	  protection. It enforces that all indirect calls must land on
1865156ff4a5SPeter Zijlstra	  an ENDBR instruction, as such, the compiler will instrument the
1866156ff4a5SPeter Zijlstra	  code with them to make this happen.
1867156ff4a5SPeter Zijlstra
1868ed53a0d9SPeter Zijlstra	  In addition to building the kernel with IBT, seal all functions that
18694cdfc11bSNur Hussein	  are not indirect call targets, avoiding them ever becoming one.
1870ed53a0d9SPeter Zijlstra
1871ed53a0d9SPeter Zijlstra	  This requires LTO like objtool runs and will slow down the build. It
1872ed53a0d9SPeter Zijlstra	  does significantly reduce the number of ENDBR instructions in the
1873ed53a0d9SPeter Zijlstra	  kernel image.
1874ed53a0d9SPeter Zijlstra
187535e97790SDave Hansenconfig X86_INTEL_MEMORY_PROTECTION_KEYS
187638f3e775SBabu Moger	prompt "Memory Protection Keys"
187735e97790SDave Hansen	def_bool y
1878284244a9SDave Hansen	# Note: only available in 64-bit mode
187938f3e775SBabu Moger	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
188052c8e601SIngo Molnar	select ARCH_USES_HIGH_VMA_FLAGS
188152c8e601SIngo Molnar	select ARCH_HAS_PKEYS
1882a7f7f624SMasahiro Yamada	help
1883284244a9SDave Hansen	  Memory Protection Keys provides a mechanism for enforcing
1884284244a9SDave Hansen	  page-based protections, but without requiring modification of the
1885284244a9SDave Hansen	  page tables when an application changes protection domains.
1886284244a9SDave Hansen
18871eecbcdcSMauro Carvalho Chehab	  For details, see Documentation/core-api/protection-keys.rst
1888284244a9SDave Hansen
1889284244a9SDave Hansen	  If unsure, say y.
189035e97790SDave Hansen
1891db616173SMichal Hockochoice
1892db616173SMichal Hocko	prompt "TSX enable mode"
1893db616173SMichal Hocko	depends on CPU_SUP_INTEL
1894db616173SMichal Hocko	default X86_INTEL_TSX_MODE_OFF
1895db616173SMichal Hocko	help
1896db616173SMichal Hocko	  Intel's TSX (Transactional Synchronization Extensions) feature
1897db616173SMichal Hocko	  allows to optimize locking protocols through lock elision which
1898db616173SMichal Hocko	  can lead to a noticeable performance boost.
1899db616173SMichal Hocko
1900db616173SMichal Hocko	  On the other hand it has been shown that TSX can be exploited
1901db616173SMichal Hocko	  to form side channel attacks (e.g. TAA) and chances are there
1902db616173SMichal Hocko	  will be more of those attacks discovered in the future.
1903db616173SMichal Hocko
1904db616173SMichal Hocko	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1905db616173SMichal Hocko	  might override this decision by tsx=on the command line parameter.
1906db616173SMichal Hocko	  Even with TSX enabled, the kernel will attempt to enable the best
1907db616173SMichal Hocko	  possible TAA mitigation setting depending on the microcode available
1908db616173SMichal Hocko	  for the particular machine.
1909db616173SMichal Hocko
1910db616173SMichal Hocko	  This option allows to set the default tsx mode between tsx=on, =off
1911db616173SMichal Hocko	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1912db616173SMichal Hocko	  details.
1913db616173SMichal Hocko
1914db616173SMichal Hocko	  Say off if not sure, auto if TSX is in use but it should be used on safe
1915db616173SMichal Hocko	  platforms or on if TSX is in use and the security aspect of tsx is not
1916db616173SMichal Hocko	  relevant.
1917db616173SMichal Hocko
1918db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_OFF
1919db616173SMichal Hocko	bool "off"
1920db616173SMichal Hocko	help
1921db616173SMichal Hocko	  TSX is disabled if possible - equals to tsx=off command line parameter.
1922db616173SMichal Hocko
1923db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_ON
1924db616173SMichal Hocko	bool "on"
1925db616173SMichal Hocko	help
1926db616173SMichal Hocko	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1927db616173SMichal Hocko	  line parameter.
1928db616173SMichal Hocko
1929db616173SMichal Hockoconfig X86_INTEL_TSX_MODE_AUTO
1930db616173SMichal Hocko	bool "auto"
1931db616173SMichal Hocko	help
1932db616173SMichal Hocko	  TSX is enabled on TSX capable HW that is believed to be safe against
1933db616173SMichal Hocko	  side channel attacks- equals the tsx=auto command line parameter.
1934db616173SMichal Hockoendchoice
1935db616173SMichal Hocko
1936e7e05452SSean Christophersonconfig X86_SGX
1937e7e05452SSean Christopherson	bool "Software Guard eXtensions (SGX)"
1938b8d1d163SDaniel Sneddon	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1939e7e05452SSean Christopherson	depends on CRYPTO=y
1940e7e05452SSean Christopherson	depends on CRYPTO_SHA256=y
1941e7e05452SSean Christopherson	select SRCU
1942e7e05452SSean Christopherson	select MMU_NOTIFIER
1943901ddbb9SJarkko Sakkinen	select NUMA_KEEP_MEMINFO if NUMA
194440e0e784STony Luck	select XARRAY_MULTI
1945e7e05452SSean Christopherson	help
1946e7e05452SSean Christopherson	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1947e7e05452SSean Christopherson	  that can be used by applications to set aside private regions of code
1948e7e05452SSean Christopherson	  and data, referred to as enclaves. An enclave's private memory can
1949e7e05452SSean Christopherson	  only be accessed by code running within the enclave. Accesses from
1950e7e05452SSean Christopherson	  outside the enclave, including other enclaves, are disallowed by
1951e7e05452SSean Christopherson	  hardware.
1952e7e05452SSean Christopherson
1953e7e05452SSean Christopherson	  If unsure, say N.
1954e7e05452SSean Christopherson
1955506f1d07SSam Ravnborgconfig EFI
19569ba16087SJan Beulich	bool "EFI runtime service support"
19575b83683fSHuang, Ying	depends on ACPI
1958f6ce5002SSergey Vlasov	select UCS2_STRING
1959022ee6c5SArd Biesheuvel	select EFI_RUNTIME_WRAPPERS
19601ff2fc02STom Lendacky	select ARCH_USE_MEMREMAP_PROT
1961a7f7f624SMasahiro Yamada	help
19628b2cb7a8SHuang, Ying	  This enables the kernel to use EFI runtime services that are
1963506f1d07SSam Ravnborg	  available (such as the EFI variable services).
1964506f1d07SSam Ravnborg
19658b2cb7a8SHuang, Ying	  This option is only useful on systems that have EFI firmware.
19668b2cb7a8SHuang, Ying	  In addition, you should use the latest ELILO loader available
19678b2cb7a8SHuang, Ying	  at <http://elilo.sourceforge.net> in order to take advantage
19688b2cb7a8SHuang, Ying	  of EFI runtime services. However, even with this option, the
19698b2cb7a8SHuang, Ying	  resultant kernel should continue to boot on existing non-EFI
19708b2cb7a8SHuang, Ying	  platforms.
1971506f1d07SSam Ravnborg
1972291f3632SMatt Flemingconfig EFI_STUB
1973291f3632SMatt Fleming	bool "EFI stub support"
1974c6dbd3e5SPeter Zijlstra	depends on EFI
19757b2a583aSMatt Fleming	select RELOCATABLE
1976a7f7f624SMasahiro Yamada	help
1977291f3632SMatt Fleming	  This kernel feature allows a bzImage to be loaded directly
1978291f3632SMatt Fleming	  by EFI firmware without the use of a bootloader.
1979291f3632SMatt Fleming
19804f4cfa6cSMauro Carvalho Chehab	  See Documentation/admin-guide/efi-stub.rst for more information.
19810c759662SMatt Fleming
1982cc3fdda2SArd Biesheuvelconfig EFI_HANDOVER_PROTOCOL
1983cc3fdda2SArd Biesheuvel	bool "EFI handover protocol (DEPRECATED)"
1984cc3fdda2SArd Biesheuvel	depends on EFI_STUB
1985cc3fdda2SArd Biesheuvel	default y
1986cc3fdda2SArd Biesheuvel	help
1987cc3fdda2SArd Biesheuvel	  Select this in order to include support for the deprecated EFI
1988cc3fdda2SArd Biesheuvel	  handover protocol, which defines alternative entry points into the
1989cc3fdda2SArd Biesheuvel	  EFI stub.  This is a practice that has no basis in the UEFI
1990cc3fdda2SArd Biesheuvel	  specification, and requires a priori knowledge on the part of the
1991cc3fdda2SArd Biesheuvel	  bootloader about Linux/x86 specific ways of passing the command line
1992cc3fdda2SArd Biesheuvel	  and initrd, and where in memory those assets may be loaded.
1993cc3fdda2SArd Biesheuvel
1994cc3fdda2SArd Biesheuvel	  If in doubt, say Y. Even though the corresponding support is not
1995cc3fdda2SArd Biesheuvel	  present in upstream GRUB or other bootloaders, most distros build
1996cc3fdda2SArd Biesheuvel	  GRUB with numerous downstream patches applied, and may rely on the
1997cc3fdda2SArd Biesheuvel	  handover protocol as as result.
1998cc3fdda2SArd Biesheuvel
19997d453eeeSMatt Flemingconfig EFI_MIXED
20007d453eeeSMatt Fleming	bool "EFI mixed-mode support"
20017d453eeeSMatt Fleming	depends on EFI_STUB && X86_64
2002a7f7f624SMasahiro Yamada	help
20037d453eeeSMatt Fleming	  Enabling this feature allows a 64-bit kernel to be booted
20047d453eeeSMatt Fleming	  on a 32-bit firmware, provided that your CPU supports 64-bit
20057d453eeeSMatt Fleming	  mode.
20067d453eeeSMatt Fleming
20077d453eeeSMatt Fleming	  Note that it is not possible to boot a mixed-mode enabled
20087d453eeeSMatt Fleming	  kernel via the EFI boot stub - a bootloader that supports
20097d453eeeSMatt Fleming	  the EFI handover protocol must be used.
20107d453eeeSMatt Fleming
20117d453eeeSMatt Fleming	  If unsure, say N.
20127d453eeeSMatt Fleming
20134059ba65SArd Biesheuvelconfig EFI_FAKE_MEMMAP
20144059ba65SArd Biesheuvel	bool "Enable EFI fake memory map"
20154059ba65SArd Biesheuvel	depends on EFI
20164059ba65SArd Biesheuvel	help
20174059ba65SArd Biesheuvel	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
20184059ba65SArd Biesheuvel	  this parameter, you can add arbitrary attribute to specific memory
20194059ba65SArd Biesheuvel	  range by updating original (firmware provided) EFI memmap.  This is
20204059ba65SArd Biesheuvel	  useful for debugging of EFI memmap related feature, e.g., Address
20214059ba65SArd Biesheuvel	  Range Mirroring feature.
20224059ba65SArd Biesheuvel
20234059ba65SArd Biesheuvelconfig EFI_MAX_FAKE_MEM
20244059ba65SArd Biesheuvel	int "maximum allowable number of ranges in efi_fake_mem boot option"
20254059ba65SArd Biesheuvel	depends on EFI_FAKE_MEMMAP
20264059ba65SArd Biesheuvel	range 1 128
20274059ba65SArd Biesheuvel	default 8
20284059ba65SArd Biesheuvel	help
20294059ba65SArd Biesheuvel	  Maximum allowable number of ranges in efi_fake_mem boot option.
20304059ba65SArd Biesheuvel	  Ranges can be set up to this value using comma-separated list.
20314059ba65SArd Biesheuvel	  The default value is 8.
20324059ba65SArd Biesheuvel
20331fff234dSArd Biesheuvelconfig EFI_RUNTIME_MAP
20341fff234dSArd Biesheuvel	bool "Export EFI runtime maps to sysfs" if EXPERT
20351fff234dSArd Biesheuvel	depends on EFI
20361fff234dSArd Biesheuvel	default KEXEC_CORE
20371fff234dSArd Biesheuvel	help
20381fff234dSArd Biesheuvel	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
20391fff234dSArd Biesheuvel	  That memory map is required by the 2nd kernel to set up EFI virtual
20401fff234dSArd Biesheuvel	  mappings after kexec, but can also be used for debugging purposes.
20411fff234dSArd Biesheuvel
20421fff234dSArd Biesheuvel	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
20431fff234dSArd Biesheuvel
20448636a1f9SMasahiro Yamadasource "kernel/Kconfig.hz"
2045506f1d07SSam Ravnborg
2046506f1d07SSam Ravnborgconfig KEXEC
2047506f1d07SSam Ravnborg	bool "kexec system call"
20482965faa5SDave Young	select KEXEC_CORE
2049a7f7f624SMasahiro Yamada	help
2050506f1d07SSam Ravnborg	  kexec is a system call that implements the ability to shutdown your
2051506f1d07SSam Ravnborg	  current kernel, and to start another kernel.  It is like a reboot
2052506f1d07SSam Ravnborg	  but it is independent of the system firmware.   And like a reboot
2053506f1d07SSam Ravnborg	  you can start any kernel with it, not just Linux.
2054506f1d07SSam Ravnborg
2055506f1d07SSam Ravnborg	  The name comes from the similarity to the exec system call.
2056506f1d07SSam Ravnborg
2057506f1d07SSam Ravnborg	  It is an ongoing process to be certain the hardware in a machine
2058506f1d07SSam Ravnborg	  is properly shutdown, so do not be surprised if this code does not
2059bf220695SGeert Uytterhoeven	  initially work for you.  As of this writing the exact hardware
2060bf220695SGeert Uytterhoeven	  interface is strongly in flux, so no good recommendation can be
2061bf220695SGeert Uytterhoeven	  made.
2062506f1d07SSam Ravnborg
206374ca317cSVivek Goyalconfig KEXEC_FILE
206474ca317cSVivek Goyal	bool "kexec file based system call"
20652965faa5SDave Young	select KEXEC_CORE
2066b69a2afdSJonathan McDowell	select HAVE_IMA_KEXEC if IMA
206774ca317cSVivek Goyal	depends on X86_64
206874ca317cSVivek Goyal	depends on CRYPTO=y
206974ca317cSVivek Goyal	depends on CRYPTO_SHA256=y
2070a7f7f624SMasahiro Yamada	help
207174ca317cSVivek Goyal	  This is new version of kexec system call. This system call is
207274ca317cSVivek Goyal	  file based and takes file descriptors as system call argument
207374ca317cSVivek Goyal	  for kernel and initramfs as opposed to list of segments as
207474ca317cSVivek Goyal	  accepted by previous system call.
207574ca317cSVivek Goyal
2076b799a09fSAKASHI Takahiroconfig ARCH_HAS_KEXEC_PURGATORY
2077b799a09fSAKASHI Takahiro	def_bool KEXEC_FILE
2078b799a09fSAKASHI Takahiro
207999d5cadfSJiri Bohacconfig KEXEC_SIG
20808e7d8381SVivek Goyal	bool "Verify kernel signature during kexec_file_load() syscall"
208174ca317cSVivek Goyal	depends on KEXEC_FILE
2082a7f7f624SMasahiro Yamada	help
208399d5cadfSJiri Bohac
208499d5cadfSJiri Bohac	  This option makes the kexec_file_load() syscall check for a valid
208599d5cadfSJiri Bohac	  signature of the kernel image.  The image can still be loaded without
208699d5cadfSJiri Bohac	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
208799d5cadfSJiri Bohac	  there's a signature that we can check, then it must be valid.
208899d5cadfSJiri Bohac
208999d5cadfSJiri Bohac	  In addition to this option, you need to enable signature
209099d5cadfSJiri Bohac	  verification for the corresponding kernel image type being
209199d5cadfSJiri Bohac	  loaded in order for this to work.
209299d5cadfSJiri Bohac
209399d5cadfSJiri Bohacconfig KEXEC_SIG_FORCE
209499d5cadfSJiri Bohac	bool "Require a valid signature in kexec_file_load() syscall"
209599d5cadfSJiri Bohac	depends on KEXEC_SIG
2096a7f7f624SMasahiro Yamada	help
20978e7d8381SVivek Goyal	  This option makes kernel signature verification mandatory for
2098d8eb8940SBorislav Petkov	  the kexec_file_load() syscall.
20998e7d8381SVivek Goyal
21008e7d8381SVivek Goyalconfig KEXEC_BZIMAGE_VERIFY_SIG
21018e7d8381SVivek Goyal	bool "Enable bzImage signature verification support"
210299d5cadfSJiri Bohac	depends on KEXEC_SIG
21038e7d8381SVivek Goyal	depends on SIGNED_PE_FILE_VERIFICATION
21048e7d8381SVivek Goyal	select SYSTEM_TRUSTED_KEYRING
2105a7f7f624SMasahiro Yamada	help
21068e7d8381SVivek Goyal	  Enable bzImage signature verification support.
21078e7d8381SVivek Goyal
2108506f1d07SSam Ravnborgconfig CRASH_DUMP
210904b69447SPavel Machek	bool "kernel crash dumps"
2110506f1d07SSam Ravnborg	depends on X86_64 || (X86_32 && HIGHMEM)
2111a7f7f624SMasahiro Yamada	help
2112506f1d07SSam Ravnborg	  Generate crash dump after being started by kexec.
2113506f1d07SSam Ravnborg	  This should be normally only set in special crash dump kernels
2114506f1d07SSam Ravnborg	  which are loaded in the main kernel with kexec-tools into
2115506f1d07SSam Ravnborg	  a specially reserved region and then later executed after
2116506f1d07SSam Ravnborg	  a crash by kdump/kexec. The crash dump kernel must be compiled
2117506f1d07SSam Ravnborg	  to a memory address not used by the main kernel or BIOS using
2118506f1d07SSam Ravnborg	  PHYSICAL_START, or it must be built as a relocatable image
2119506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y).
2120330d4810SMauro Carvalho Chehab	  For more details see Documentation/admin-guide/kdump/kdump.rst
2121506f1d07SSam Ravnborg
21223ab83521SHuang Yingconfig KEXEC_JUMP
21236ea30386SKees Cook	bool "kexec jump"
2124fee7b0d8SHuang Ying	depends on KEXEC && HIBERNATION
2125a7f7f624SMasahiro Yamada	help
212689081d17SHuang Ying	  Jump between original kernel and kexeced kernel and invoke
212789081d17SHuang Ying	  code in physical address mode via KEXEC
21283ab83521SHuang Ying
2129506f1d07SSam Ravnborgconfig PHYSICAL_START
21306a108a14SDavid Rientjes	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2131ceefccc9SH. Peter Anvin	default "0x1000000"
2132a7f7f624SMasahiro Yamada	help
2133506f1d07SSam Ravnborg	  This gives the physical address where the kernel is loaded.
2134506f1d07SSam Ravnborg
2135506f1d07SSam Ravnborg	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2136506f1d07SSam Ravnborg	  bzImage will decompress itself to above physical address and
2137506f1d07SSam Ravnborg	  run from there. Otherwise, bzImage will run from the address where
2138506f1d07SSam Ravnborg	  it has been loaded by the boot loader and will ignore above physical
2139506f1d07SSam Ravnborg	  address.
2140506f1d07SSam Ravnborg
2141506f1d07SSam Ravnborg	  In normal kdump cases one does not have to set/change this option
2142506f1d07SSam Ravnborg	  as now bzImage can be compiled as a completely relocatable image
2143506f1d07SSam Ravnborg	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2144506f1d07SSam Ravnborg	  address. This option is mainly useful for the folks who don't want
2145506f1d07SSam Ravnborg	  to use a bzImage for capturing the crash dump and want to use a
2146506f1d07SSam Ravnborg	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2147506f1d07SSam Ravnborg	  to be specifically compiled to run from a specific memory area
2148506f1d07SSam Ravnborg	  (normally a reserved region) and this option comes handy.
2149506f1d07SSam Ravnborg
2150ceefccc9SH. Peter Anvin	  So if you are using bzImage for capturing the crash dump,
2151ceefccc9SH. Peter Anvin	  leave the value here unchanged to 0x1000000 and set
2152ceefccc9SH. Peter Anvin	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2153ceefccc9SH. Peter Anvin	  for capturing the crash dump change this value to start of
2154ceefccc9SH. Peter Anvin	  the reserved region.  In other words, it can be set based on
2155ceefccc9SH. Peter Anvin	  the "X" value as specified in the "crashkernel=YM@XM"
2156ceefccc9SH. Peter Anvin	  command line boot parameter passed to the panic-ed
2157330d4810SMauro Carvalho Chehab	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2158ceefccc9SH. Peter Anvin	  for more details about crash dumps.
2159506f1d07SSam Ravnborg
2160506f1d07SSam Ravnborg	  Usage of bzImage for capturing the crash dump is recommended as
2161506f1d07SSam Ravnborg	  one does not have to build two kernels. Same kernel can be used
2162506f1d07SSam Ravnborg	  as production kernel and capture kernel. Above option should have
2163506f1d07SSam Ravnborg	  gone away after relocatable bzImage support is introduced. But it
2164506f1d07SSam Ravnborg	  is present because there are users out there who continue to use
2165506f1d07SSam Ravnborg	  vmlinux for dump capture. This option should go away down the
2166506f1d07SSam Ravnborg	  line.
2167506f1d07SSam Ravnborg
2168506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2169506f1d07SSam Ravnborg
2170506f1d07SSam Ravnborgconfig RELOCATABLE
217126717808SH. Peter Anvin	bool "Build a relocatable kernel"
217226717808SH. Peter Anvin	default y
2173a7f7f624SMasahiro Yamada	help
2174506f1d07SSam Ravnborg	  This builds a kernel image that retains relocation information
2175506f1d07SSam Ravnborg	  so it can be loaded someplace besides the default 1MB.
2176506f1d07SSam Ravnborg	  The relocations tend to make the kernel binary about 10% larger,
2177506f1d07SSam Ravnborg	  but are discarded at runtime.
2178506f1d07SSam Ravnborg
2179506f1d07SSam Ravnborg	  One use is for the kexec on panic case where the recovery kernel
2180506f1d07SSam Ravnborg	  must live at a different physical address than the primary
2181506f1d07SSam Ravnborg	  kernel.
2182506f1d07SSam Ravnborg
2183506f1d07SSam Ravnborg	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2184506f1d07SSam Ravnborg	  it has been loaded at and the compile time physical address
21858ab3820fSKees Cook	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2186506f1d07SSam Ravnborg
21878ab3820fSKees Cookconfig RANDOMIZE_BASE
2188e8581e3dSBaoquan He	bool "Randomize the address of the kernel image (KASLR)"
21898ab3820fSKees Cook	depends on RELOCATABLE
21906807c846SIngo Molnar	default y
2191a7f7f624SMasahiro Yamada	help
2192e8581e3dSBaoquan He	  In support of Kernel Address Space Layout Randomization (KASLR),
2193e8581e3dSBaoquan He	  this randomizes the physical address at which the kernel image
2194e8581e3dSBaoquan He	  is decompressed and the virtual address where the kernel
2195e8581e3dSBaoquan He	  image is mapped, as a security feature that deters exploit
2196e8581e3dSBaoquan He	  attempts relying on knowledge of the location of kernel
2197e8581e3dSBaoquan He	  code internals.
2198e8581e3dSBaoquan He
2199ed9f007eSKees Cook	  On 64-bit, the kernel physical and virtual addresses are
2200ed9f007eSKees Cook	  randomized separately. The physical address will be anywhere
2201ed9f007eSKees Cook	  between 16MB and the top of physical memory (up to 64TB). The
2202ed9f007eSKees Cook	  virtual address will be randomized from 16MB up to 1GB (9 bits
2203ed9f007eSKees Cook	  of entropy). Note that this also reduces the memory space
2204ed9f007eSKees Cook	  available to kernel modules from 1.5GB to 1GB.
2205ed9f007eSKees Cook
2206ed9f007eSKees Cook	  On 32-bit, the kernel physical and virtual addresses are
2207ed9f007eSKees Cook	  randomized together. They will be randomized from 16MB up to
2208ed9f007eSKees Cook	  512MB (8 bits of entropy).
22098ab3820fSKees Cook
2210a653f356SKees Cook	  Entropy is generated using the RDRAND instruction if it is
2211e8581e3dSBaoquan He	  supported. If RDTSC is supported, its value is mixed into
2212e8581e3dSBaoquan He	  the entropy pool as well. If neither RDRAND nor RDTSC are
2213ed9f007eSKees Cook	  supported, then entropy is read from the i8254 timer. The
2214ed9f007eSKees Cook	  usable entropy is limited by the kernel being built using
2215ed9f007eSKees Cook	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2216ed9f007eSKees Cook	  minimum of 2MB. As a result, only 10 bits of entropy are
2217ed9f007eSKees Cook	  theoretically possible, but the implementations are further
2218ed9f007eSKees Cook	  limited due to memory layouts.
2219e8581e3dSBaoquan He
22206807c846SIngo Molnar	  If unsure, say Y.
2221da2b6fb9SKees Cook
22228ab3820fSKees Cook# Relocation on x86 needs some additional build support
2223845adf72SH. Peter Anvinconfig X86_NEED_RELOCS
2224845adf72SH. Peter Anvin	def_bool y
22258ab3820fSKees Cook	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2226845adf72SH. Peter Anvin
2227506f1d07SSam Ravnborgconfig PHYSICAL_ALIGN
2228a0215061SKees Cook	hex "Alignment value to which kernel should be aligned"
22298ab3820fSKees Cook	default "0x200000"
2230a0215061SKees Cook	range 0x2000 0x1000000 if X86_32
2231a0215061SKees Cook	range 0x200000 0x1000000 if X86_64
2232a7f7f624SMasahiro Yamada	help
2233506f1d07SSam Ravnborg	  This value puts the alignment restrictions on physical address
2234506f1d07SSam Ravnborg	  where kernel is loaded and run from. Kernel is compiled for an
2235506f1d07SSam Ravnborg	  address which meets above alignment restriction.
2236506f1d07SSam Ravnborg
2237506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2238506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2239506f1d07SSam Ravnborg	  address aligned to above value and run from there.
2240506f1d07SSam Ravnborg
2241506f1d07SSam Ravnborg	  If bootloader loads the kernel at a non-aligned address and
2242506f1d07SSam Ravnborg	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2243506f1d07SSam Ravnborg	  load address and decompress itself to the address it has been
2244506f1d07SSam Ravnborg	  compiled for and run from there. The address for which kernel is
2245506f1d07SSam Ravnborg	  compiled already meets above alignment restrictions. Hence the
2246506f1d07SSam Ravnborg	  end result is that kernel runs from a physical address meeting
2247506f1d07SSam Ravnborg	  above alignment restrictions.
2248506f1d07SSam Ravnborg
2249a0215061SKees Cook	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2250a0215061SKees Cook	  this value must be a multiple of 0x200000.
2251a0215061SKees Cook
2252506f1d07SSam Ravnborg	  Don't change this unless you know what you are doing.
2253506f1d07SSam Ravnborg
2254eedb92abSKirill A. Shutemovconfig DYNAMIC_MEMORY_LAYOUT
2255eedb92abSKirill A. Shutemov	bool
2256a7f7f624SMasahiro Yamada	help
2257eedb92abSKirill A. Shutemov	  This option makes base addresses of vmalloc and vmemmap as well as
2258eedb92abSKirill A. Shutemov	  __PAGE_OFFSET movable during boot.
2259eedb92abSKirill A. Shutemov
22600483e1faSThomas Garnierconfig RANDOMIZE_MEMORY
22610483e1faSThomas Garnier	bool "Randomize the kernel memory sections"
22620483e1faSThomas Garnier	depends on X86_64
22630483e1faSThomas Garnier	depends on RANDOMIZE_BASE
2264eedb92abSKirill A. Shutemov	select DYNAMIC_MEMORY_LAYOUT
22650483e1faSThomas Garnier	default RANDOMIZE_BASE
2266a7f7f624SMasahiro Yamada	help
22670483e1faSThomas Garnier	  Randomizes the base virtual address of kernel memory sections
22680483e1faSThomas Garnier	  (physical memory mapping, vmalloc & vmemmap). This security feature
22690483e1faSThomas Garnier	  makes exploits relying on predictable memory locations less reliable.
22700483e1faSThomas Garnier
22710483e1faSThomas Garnier	  The order of allocations remains unchanged. Entropy is generated in
22720483e1faSThomas Garnier	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
22730483e1faSThomas Garnier	  configuration have in average 30,000 different possible virtual
22740483e1faSThomas Garnier	  addresses for each memory section.
22750483e1faSThomas Garnier
22766807c846SIngo Molnar	  If unsure, say Y.
22770483e1faSThomas Garnier
227890397a41SThomas Garnierconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
227990397a41SThomas Garnier	hex "Physical memory mapping padding" if EXPERT
228090397a41SThomas Garnier	depends on RANDOMIZE_MEMORY
228190397a41SThomas Garnier	default "0xa" if MEMORY_HOTPLUG
228290397a41SThomas Garnier	default "0x0"
228390397a41SThomas Garnier	range 0x1 0x40 if MEMORY_HOTPLUG
228490397a41SThomas Garnier	range 0x0 0x40
2285a7f7f624SMasahiro Yamada	help
228690397a41SThomas Garnier	  Define the padding in terabytes added to the existing physical
228790397a41SThomas Garnier	  memory size during kernel memory randomization. It is useful
228890397a41SThomas Garnier	  for memory hotplug support but reduces the entropy available for
228990397a41SThomas Garnier	  address randomization.
229090397a41SThomas Garnier
229190397a41SThomas Garnier	  If unsure, leave at the default value.
229290397a41SThomas Garnier
2293506f1d07SSam Ravnborgconfig HOTPLUG_CPU
2294bebd024eSThomas Gleixner	def_bool y
229540b31360SStephen Rothwell	depends on SMP
2296506f1d07SSam Ravnborg
229780aa1dffSFenghua Yuconfig BOOTPARAM_HOTPLUG_CPU0
229880aa1dffSFenghua Yu	bool "Set default setting of cpu0_hotpluggable"
22992c922cd0SKees Cook	depends on HOTPLUG_CPU
2300a7f7f624SMasahiro Yamada	help
230180aa1dffSFenghua Yu	  Set whether default state of cpu0_hotpluggable is on or off.
230280aa1dffSFenghua Yu
230380aa1dffSFenghua Yu	  Say Y here to enable CPU0 hotplug by default. If this switch
230480aa1dffSFenghua Yu	  is turned on, there is no need to give cpu0_hotplug kernel
230580aa1dffSFenghua Yu	  parameter and the CPU0 hotplug feature is enabled by default.
230680aa1dffSFenghua Yu
230780aa1dffSFenghua Yu	  Please note: there are two known CPU0 dependencies if you want
230880aa1dffSFenghua Yu	  to enable the CPU0 hotplug feature either by this switch or by
230980aa1dffSFenghua Yu	  cpu0_hotplug kernel parameter.
231080aa1dffSFenghua Yu
231180aa1dffSFenghua Yu	  First, resume from hibernate or suspend always starts from CPU0.
231280aa1dffSFenghua Yu	  So hibernate and suspend are prevented if CPU0 is offline.
231380aa1dffSFenghua Yu
231480aa1dffSFenghua Yu	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
231580aa1dffSFenghua Yu	  offline if any interrupt can not migrate out of CPU0. There may
231680aa1dffSFenghua Yu	  be other CPU0 dependencies.
231780aa1dffSFenghua Yu
231880aa1dffSFenghua Yu	  Please make sure the dependencies are under your control before
231980aa1dffSFenghua Yu	  you enable this feature.
232080aa1dffSFenghua Yu
232180aa1dffSFenghua Yu	  Say N if you don't want to enable CPU0 hotplug feature by default.
232280aa1dffSFenghua Yu	  You still can enable the CPU0 hotplug feature at boot by kernel
232380aa1dffSFenghua Yu	  parameter cpu0_hotplug.
232480aa1dffSFenghua Yu
2325a71c8bc5SFenghua Yuconfig DEBUG_HOTPLUG_CPU0
2326a71c8bc5SFenghua Yu	def_bool n
2327a71c8bc5SFenghua Yu	prompt "Debug CPU0 hotplug"
23282c922cd0SKees Cook	depends on HOTPLUG_CPU
2329a7f7f624SMasahiro Yamada	help
2330a71c8bc5SFenghua Yu	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2331a71c8bc5SFenghua Yu	  soon as possible and boots up userspace with CPU0 offlined. User
2332a71c8bc5SFenghua Yu	  can online CPU0 back after boot time.
2333a71c8bc5SFenghua Yu
2334a71c8bc5SFenghua Yu	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2335a71c8bc5SFenghua Yu	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2336a71c8bc5SFenghua Yu	  compilation or giving cpu0_hotplug kernel parameter at boot.
2337a71c8bc5SFenghua Yu
2338a71c8bc5SFenghua Yu	  If unsure, say N.
2339a71c8bc5SFenghua Yu
2340506f1d07SSam Ravnborgconfig COMPAT_VDSO
2341b0b49f26SAndy Lutomirski	def_bool n
2342b0b49f26SAndy Lutomirski	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2343953fee1dSIngo Molnar	depends on COMPAT_32
2344a7f7f624SMasahiro Yamada	help
2345b0b49f26SAndy Lutomirski	  Certain buggy versions of glibc will crash if they are
2346b0b49f26SAndy Lutomirski	  presented with a 32-bit vDSO that is not mapped at the address
2347b0b49f26SAndy Lutomirski	  indicated in its segment table.
2348e84446deSRandy Dunlap
2349b0b49f26SAndy Lutomirski	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2350b0b49f26SAndy Lutomirski	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2351b0b49f26SAndy Lutomirski	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2352b0b49f26SAndy Lutomirski	  the only released version with the bug, but OpenSUSE 9
2353b0b49f26SAndy Lutomirski	  contains a buggy "glibc 2.3.2".
2354506f1d07SSam Ravnborg
2355b0b49f26SAndy Lutomirski	  The symptom of the bug is that everything crashes on startup, saying:
2356b0b49f26SAndy Lutomirski	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2357b0b49f26SAndy Lutomirski
2358b0b49f26SAndy Lutomirski	  Saying Y here changes the default value of the vdso32 boot
2359b0b49f26SAndy Lutomirski	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2360b0b49f26SAndy Lutomirski	  This works around the glibc bug but hurts performance.
2361b0b49f26SAndy Lutomirski
2362b0b49f26SAndy Lutomirski	  If unsure, say N: if you are compiling your own kernel, you
2363b0b49f26SAndy Lutomirski	  are unlikely to be using a buggy version of glibc.
2364506f1d07SSam Ravnborg
23653dc33bd3SKees Cookchoice
23663dc33bd3SKees Cook	prompt "vsyscall table for legacy applications"
23673dc33bd3SKees Cook	depends on X86_64
2368625b7b7fSAndy Lutomirski	default LEGACY_VSYSCALL_XONLY
23693dc33bd3SKees Cook	help
23703dc33bd3SKees Cook	  Legacy user code that does not know how to find the vDSO expects
23713dc33bd3SKees Cook	  to be able to issue three syscalls by calling fixed addresses in
23723dc33bd3SKees Cook	  kernel space. Since this location is not randomized with ASLR,
23733dc33bd3SKees Cook	  it can be used to assist security vulnerability exploitation.
23743dc33bd3SKees Cook
23753dc33bd3SKees Cook	  This setting can be changed at boot time via the kernel command
2376bf00745eSAndy Lutomirski	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2377bf00745eSAndy Lutomirski	  is deprecated and can only be enabled using the kernel command
2378bf00745eSAndy Lutomirski	  line.
23793dc33bd3SKees Cook
23803dc33bd3SKees Cook	  On a system with recent enough glibc (2.14 or newer) and no
23813dc33bd3SKees Cook	  static binaries, you can say None without a performance penalty
23823dc33bd3SKees Cook	  to improve security.
23833dc33bd3SKees Cook
2384bd49e16eSAndy Lutomirski	  If unsure, select "Emulate execution only".
23853dc33bd3SKees Cook
2386bd49e16eSAndy Lutomirski	config LEGACY_VSYSCALL_XONLY
2387bd49e16eSAndy Lutomirski		bool "Emulate execution only"
2388bd49e16eSAndy Lutomirski		help
2389bd49e16eSAndy Lutomirski		  The kernel traps and emulates calls into the fixed vsyscall
2390bd49e16eSAndy Lutomirski		  address mapping and does not allow reads.  This
2391bd49e16eSAndy Lutomirski		  configuration is recommended when userspace might use the
2392bd49e16eSAndy Lutomirski		  legacy vsyscall area but support for legacy binary
2393bd49e16eSAndy Lutomirski		  instrumentation of legacy code is not needed.  It mitigates
2394bd49e16eSAndy Lutomirski		  certain uses of the vsyscall area as an ASLR-bypassing
2395bd49e16eSAndy Lutomirski		  buffer.
23963dc33bd3SKees Cook
23973dc33bd3SKees Cook	config LEGACY_VSYSCALL_NONE
23983dc33bd3SKees Cook		bool "None"
23993dc33bd3SKees Cook		help
24003dc33bd3SKees Cook		  There will be no vsyscall mapping at all. This will
24013dc33bd3SKees Cook		  eliminate any risk of ASLR bypass due to the vsyscall
24023dc33bd3SKees Cook		  fixed address mapping. Attempts to use the vsyscalls
24033dc33bd3SKees Cook		  will be reported to dmesg, so that either old or
24043dc33bd3SKees Cook		  malicious userspace programs can be identified.
24053dc33bd3SKees Cook
24063dc33bd3SKees Cookendchoice
24073dc33bd3SKees Cook
2408516cbf37STim Birdconfig CMDLINE_BOOL
2409516cbf37STim Bird	bool "Built-in kernel command line"
2410a7f7f624SMasahiro Yamada	help
2411516cbf37STim Bird	  Allow for specifying boot arguments to the kernel at
2412516cbf37STim Bird	  build time.  On some systems (e.g. embedded ones), it is
2413516cbf37STim Bird	  necessary or convenient to provide some or all of the
2414516cbf37STim Bird	  kernel boot arguments with the kernel itself (that is,
2415516cbf37STim Bird	  to not rely on the boot loader to provide them.)
2416516cbf37STim Bird
2417516cbf37STim Bird	  To compile command line arguments into the kernel,
2418516cbf37STim Bird	  set this option to 'Y', then fill in the
241969711ca1SSébastien Hinderer	  boot arguments in CONFIG_CMDLINE.
2420516cbf37STim Bird
2421516cbf37STim Bird	  Systems with fully functional boot loaders (i.e. non-embedded)
2422516cbf37STim Bird	  should leave this option set to 'N'.
2423516cbf37STim Bird
2424516cbf37STim Birdconfig CMDLINE
2425516cbf37STim Bird	string "Built-in kernel command string"
2426516cbf37STim Bird	depends on CMDLINE_BOOL
2427516cbf37STim Bird	default ""
2428a7f7f624SMasahiro Yamada	help
2429516cbf37STim Bird	  Enter arguments here that should be compiled into the kernel
2430516cbf37STim Bird	  image and used at boot time.  If the boot loader provides a
2431516cbf37STim Bird	  command line at boot time, it is appended to this string to
2432516cbf37STim Bird	  form the full kernel command line, when the system boots.
2433516cbf37STim Bird
2434516cbf37STim Bird	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2435516cbf37STim Bird	  change this behavior.
2436516cbf37STim Bird
2437516cbf37STim Bird	  In most cases, the command line (whether built-in or provided
2438516cbf37STim Bird	  by the boot loader) should specify the device for the root
2439516cbf37STim Bird	  file system.
2440516cbf37STim Bird
2441516cbf37STim Birdconfig CMDLINE_OVERRIDE
2442516cbf37STim Bird	bool "Built-in command line overrides boot loader arguments"
2443645e6466SAnders Roxell	depends on CMDLINE_BOOL && CMDLINE != ""
2444a7f7f624SMasahiro Yamada	help
2445516cbf37STim Bird	  Set this option to 'Y' to have the kernel ignore the boot loader
2446516cbf37STim Bird	  command line, and use ONLY the built-in command line.
2447516cbf37STim Bird
2448516cbf37STim Bird	  This is used to work around broken boot loaders.  This should
2449516cbf37STim Bird	  be set to 'N' under normal conditions.
2450516cbf37STim Bird
2451a5b9e5a2SAndy Lutomirskiconfig MODIFY_LDT_SYSCALL
2452a5b9e5a2SAndy Lutomirski	bool "Enable the LDT (local descriptor table)" if EXPERT
2453a5b9e5a2SAndy Lutomirski	default y
2454a7f7f624SMasahiro Yamada	help
2455a5b9e5a2SAndy Lutomirski	  Linux can allow user programs to install a per-process x86
2456a5b9e5a2SAndy Lutomirski	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2457a5b9e5a2SAndy Lutomirski	  call.  This is required to run 16-bit or segmented code such as
2458a5b9e5a2SAndy Lutomirski	  DOSEMU or some Wine programs.  It is also used by some very old
2459a5b9e5a2SAndy Lutomirski	  threading libraries.
2460a5b9e5a2SAndy Lutomirski
2461a5b9e5a2SAndy Lutomirski	  Enabling this feature adds a small amount of overhead to
2462a5b9e5a2SAndy Lutomirski	  context switches and increases the low-level kernel attack
2463a5b9e5a2SAndy Lutomirski	  surface.  Disabling it removes the modify_ldt(2) system call.
2464a5b9e5a2SAndy Lutomirski
2465a5b9e5a2SAndy Lutomirski	  Saying 'N' here may make sense for embedded or server kernels.
2466a5b9e5a2SAndy Lutomirski
24673aac3ebeSThomas Gleixnerconfig STRICT_SIGALTSTACK_SIZE
24683aac3ebeSThomas Gleixner	bool "Enforce strict size checking for sigaltstack"
24693aac3ebeSThomas Gleixner	depends on DYNAMIC_SIGFRAME
24703aac3ebeSThomas Gleixner	help
24713aac3ebeSThomas Gleixner	  For historical reasons MINSIGSTKSZ is a constant which became
24723aac3ebeSThomas Gleixner	  already too small with AVX512 support. Add a mechanism to
24733aac3ebeSThomas Gleixner	  enforce strict checking of the sigaltstack size against the
24743aac3ebeSThomas Gleixner	  real size of the FPU frame. This option enables the check
24753aac3ebeSThomas Gleixner	  by default. It can also be controlled via the kernel command
24763aac3ebeSThomas Gleixner	  line option 'strict_sas_size' independent of this config
24773aac3ebeSThomas Gleixner	  switch. Enabling it might break existing applications which
24783aac3ebeSThomas Gleixner	  allocate a too small sigaltstack but 'work' because they
24793aac3ebeSThomas Gleixner	  never get a signal delivered.
24803aac3ebeSThomas Gleixner
24813aac3ebeSThomas Gleixner	  Say 'N' unless you want to really enforce this check.
24823aac3ebeSThomas Gleixner
2483b700e7f0SSeth Jenningssource "kernel/livepatch/Kconfig"
2484b700e7f0SSeth Jennings
2485506f1d07SSam Ravnborgendmenu
2486506f1d07SSam Ravnborg
2487f43b9876SPeter Zijlstraconfig CC_HAS_SLS
2488f43b9876SPeter Zijlstra	def_bool $(cc-option,-mharden-sls=all)
2489f43b9876SPeter Zijlstra
2490f43b9876SPeter Zijlstraconfig CC_HAS_RETURN_THUNK
2491f43b9876SPeter Zijlstra	def_bool $(cc-option,-mfunction-return=thunk-extern)
2492f43b9876SPeter Zijlstra
2493bea75b33SThomas Gleixnerconfig CC_HAS_ENTRY_PADDING
2494bea75b33SThomas Gleixner	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2495bea75b33SThomas Gleixner
2496bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_CFI
2497bea75b33SThomas Gleixner	int
2498bea75b33SThomas Gleixner	default 59 if FUNCTION_ALIGNMENT_64B
2499bea75b33SThomas Gleixner	default 27 if FUNCTION_ALIGNMENT_32B
2500bea75b33SThomas Gleixner	default 11 if FUNCTION_ALIGNMENT_16B
2501bea75b33SThomas Gleixner	default  3 if FUNCTION_ALIGNMENT_8B
2502bea75b33SThomas Gleixner	default  0
2503bea75b33SThomas Gleixner
2504bea75b33SThomas Gleixner# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2505bea75b33SThomas Gleixner# except Kconfig can't do arithmetic :/
2506bea75b33SThomas Gleixnerconfig FUNCTION_PADDING_BYTES
2507bea75b33SThomas Gleixner	int
2508bea75b33SThomas Gleixner	default FUNCTION_PADDING_CFI if CFI_CLANG
2509bea75b33SThomas Gleixner	default FUNCTION_ALIGNMENT
2510bea75b33SThomas Gleixner
2511931ab636SPeter Zijlstraconfig CALL_PADDING
2512931ab636SPeter Zijlstra	def_bool n
2513931ab636SPeter Zijlstra	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2514931ab636SPeter Zijlstra	select FUNCTION_ALIGNMENT_16B
2515931ab636SPeter Zijlstra
2516931ab636SPeter Zijlstraconfig FINEIBT
2517931ab636SPeter Zijlstra	def_bool y
2518931ab636SPeter Zijlstra	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2519931ab636SPeter Zijlstra	select CALL_PADDING
2520931ab636SPeter Zijlstra
25218f7c0d8bSThomas Gleixnerconfig HAVE_CALL_THUNKS
25228f7c0d8bSThomas Gleixner	def_bool y
2523bea75b33SThomas Gleixner	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
25248f7c0d8bSThomas Gleixner
25258f7c0d8bSThomas Gleixnerconfig CALL_THUNKS
25268f7c0d8bSThomas Gleixner	def_bool n
2527931ab636SPeter Zijlstra	select CALL_PADDING
25288f7c0d8bSThomas Gleixner
2529b341b20dSPeter Zijlstraconfig PREFIX_SYMBOLS
2530b341b20dSPeter Zijlstra	def_bool y
2531931ab636SPeter Zijlstra	depends on CALL_PADDING && !CFI_CLANG
2532b341b20dSPeter Zijlstra
2533f43b9876SPeter Zijlstramenuconfig SPECULATION_MITIGATIONS
2534f43b9876SPeter Zijlstra	bool "Mitigations for speculative execution vulnerabilities"
2535f43b9876SPeter Zijlstra	default y
2536f43b9876SPeter Zijlstra	help
2537f43b9876SPeter Zijlstra	  Say Y here to enable options which enable mitigations for
2538f43b9876SPeter Zijlstra	  speculative execution hardware vulnerabilities.
2539f43b9876SPeter Zijlstra
2540f43b9876SPeter Zijlstra	  If you say N, all mitigations will be disabled. You really
2541f43b9876SPeter Zijlstra	  should know what you are doing to say so.
2542f43b9876SPeter Zijlstra
2543f43b9876SPeter Zijlstraif SPECULATION_MITIGATIONS
2544f43b9876SPeter Zijlstra
2545f43b9876SPeter Zijlstraconfig PAGE_TABLE_ISOLATION
2546f43b9876SPeter Zijlstra	bool "Remove the kernel mapping in user mode"
2547f43b9876SPeter Zijlstra	default y
2548f43b9876SPeter Zijlstra	depends on (X86_64 || X86_PAE)
2549f43b9876SPeter Zijlstra	help
2550f43b9876SPeter Zijlstra	  This feature reduces the number of hardware side channels by
2551f43b9876SPeter Zijlstra	  ensuring that the majority of kernel addresses are not mapped
2552f43b9876SPeter Zijlstra	  into userspace.
2553f43b9876SPeter Zijlstra
2554*ff61f079SJonathan Corbet	  See Documentation/arch/x86/pti.rst for more details.
2555f43b9876SPeter Zijlstra
2556f43b9876SPeter Zijlstraconfig RETPOLINE
2557f43b9876SPeter Zijlstra	bool "Avoid speculative indirect branches in kernel"
2558f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2559f43b9876SPeter Zijlstra	default y
2560f43b9876SPeter Zijlstra	help
2561f43b9876SPeter Zijlstra	  Compile kernel with the retpoline compiler options to guard against
2562f43b9876SPeter Zijlstra	  kernel-to-user data leaks by avoiding speculative indirect
2563f43b9876SPeter Zijlstra	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2564f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2565f43b9876SPeter Zijlstra
2566f43b9876SPeter Zijlstraconfig RETHUNK
2567f43b9876SPeter Zijlstra	bool "Enable return-thunks"
2568f43b9876SPeter Zijlstra	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2569f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2570b648ab48SBen Hutchings	default y if X86_64
2571f43b9876SPeter Zijlstra	help
2572f43b9876SPeter Zijlstra	  Compile the kernel with the return-thunks compiler option to guard
2573f43b9876SPeter Zijlstra	  against kernel-to-user data leaks by avoiding return speculation.
2574f43b9876SPeter Zijlstra	  Requires a compiler with -mfunction-return=thunk-extern
2575f43b9876SPeter Zijlstra	  support for full protection. The kernel may run slower.
2576f43b9876SPeter Zijlstra
2577f43b9876SPeter Zijlstraconfig CPU_UNRET_ENTRY
2578f43b9876SPeter Zijlstra	bool "Enable UNRET on kernel entry"
2579b648ab48SBen Hutchings	depends on CPU_SUP_AMD && RETHUNK && X86_64
2580f43b9876SPeter Zijlstra	default y
2581f43b9876SPeter Zijlstra	help
2582f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=unret mitigation.
2583f43b9876SPeter Zijlstra
258480e4c1cdSThomas Gleixnerconfig CALL_DEPTH_TRACKING
258580e4c1cdSThomas Gleixner	bool "Mitigate RSB underflow with call depth tracking"
258680e4c1cdSThomas Gleixner	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
258780e4c1cdSThomas Gleixner	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
258880e4c1cdSThomas Gleixner	select CALL_THUNKS
258980e4c1cdSThomas Gleixner	default y
259080e4c1cdSThomas Gleixner	help
259180e4c1cdSThomas Gleixner	  Compile the kernel with call depth tracking to mitigate the Intel
259280e4c1cdSThomas Gleixner	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
259380e4c1cdSThomas Gleixner	  mitigation is off by default and needs to be enabled on the
259480e4c1cdSThomas Gleixner	  kernel command line via the retbleed=stuff option. For
259580e4c1cdSThomas Gleixner	  non-affected systems the overhead of this option is marginal as
259680e4c1cdSThomas Gleixner	  the call depth tracking is using run-time generated call thunks
259780e4c1cdSThomas Gleixner	  in a compiler generated padding area and call patching. This
259880e4c1cdSThomas Gleixner	  increases text size by ~5%. For non affected systems this space
259980e4c1cdSThomas Gleixner	  is unused. On affected SKL systems this results in a significant
260080e4c1cdSThomas Gleixner	  performance gain over the IBRS mitigation.
260180e4c1cdSThomas Gleixner
2602e81dc127SThomas Gleixnerconfig CALL_THUNKS_DEBUG
2603e81dc127SThomas Gleixner	bool "Enable call thunks and call depth tracking debugging"
2604e81dc127SThomas Gleixner	depends on CALL_DEPTH_TRACKING
2605e81dc127SThomas Gleixner	select FUNCTION_ALIGNMENT_32B
2606e81dc127SThomas Gleixner	default n
2607e81dc127SThomas Gleixner	help
2608e81dc127SThomas Gleixner	  Enable call/ret counters for imbalance detection and build in
2609e81dc127SThomas Gleixner	  a noisy dmesg about callthunks generation and call patching for
2610e81dc127SThomas Gleixner	  trouble shooting. The debug prints need to be enabled on the
2611e81dc127SThomas Gleixner	  kernel command line with 'debug-callthunks'.
261254628de6SRandy Dunlap	  Only enable this when you are debugging call thunks as this
261354628de6SRandy Dunlap	  creates a noticeable runtime overhead. If unsure say N.
261480e4c1cdSThomas Gleixner
2615f43b9876SPeter Zijlstraconfig CPU_IBPB_ENTRY
2616f43b9876SPeter Zijlstra	bool "Enable IBPB on kernel entry"
2617b648ab48SBen Hutchings	depends on CPU_SUP_AMD && X86_64
2618f43b9876SPeter Zijlstra	default y
2619f43b9876SPeter Zijlstra	help
2620f43b9876SPeter Zijlstra	  Compile the kernel with support for the retbleed=ibpb mitigation.
2621f43b9876SPeter Zijlstra
2622f43b9876SPeter Zijlstraconfig CPU_IBRS_ENTRY
2623f43b9876SPeter Zijlstra	bool "Enable IBRS on kernel entry"
2624b648ab48SBen Hutchings	depends on CPU_SUP_INTEL && X86_64
2625f43b9876SPeter Zijlstra	default y
2626f43b9876SPeter Zijlstra	help
2627f43b9876SPeter Zijlstra	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2628f43b9876SPeter Zijlstra	  This mitigates both spectre_v2 and retbleed at great cost to
2629f43b9876SPeter Zijlstra	  performance.
2630f43b9876SPeter Zijlstra
2631f43b9876SPeter Zijlstraconfig SLS
2632f43b9876SPeter Zijlstra	bool "Mitigate Straight-Line-Speculation"
2633f43b9876SPeter Zijlstra	depends on CC_HAS_SLS && X86_64
2634f43b9876SPeter Zijlstra	select OBJTOOL if HAVE_OBJTOOL
2635f43b9876SPeter Zijlstra	default n
2636f43b9876SPeter Zijlstra	help
2637f43b9876SPeter Zijlstra	  Compile the kernel with straight-line-speculation options to guard
2638f43b9876SPeter Zijlstra	  against straight line speculation. The kernel image might be slightly
2639f43b9876SPeter Zijlstra	  larger.
2640f43b9876SPeter Zijlstra
2641f43b9876SPeter Zijlstraendif
2642f43b9876SPeter Zijlstra
26433072e413SMichal Hockoconfig ARCH_HAS_ADD_PAGES
26443072e413SMichal Hocko	def_bool y
26455c11f00bSDavid Hildenbrand	depends on ARCH_ENABLE_MEMORY_HOTPLUG
26463072e413SMichal Hocko
2647f91ef222SOscar Salvadorconfig ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2648f91ef222SOscar Salvador	def_bool y
2649f91ef222SOscar Salvador
2650da85f865SBjorn Helgaasmenu "Power management and ACPI options"
2651e279b6c1SSam Ravnborg
2652e279b6c1SSam Ravnborgconfig ARCH_HIBERNATION_HEADER
26533c2362e6SHarvey Harrison	def_bool y
265444556530SZhimin Gu	depends on HIBERNATION
2655e279b6c1SSam Ravnborg
2656e279b6c1SSam Ravnborgsource "kernel/power/Kconfig"
2657e279b6c1SSam Ravnborg
2658e279b6c1SSam Ravnborgsource "drivers/acpi/Kconfig"
2659e279b6c1SSam Ravnborg
2660a6b68076SAndi Kleenconfig X86_APM_BOOT
26616fc108a0SJan Beulich	def_bool y
2662282e5aabSPaul Bolle	depends on APM
2663a6b68076SAndi Kleen
2664e279b6c1SSam Ravnborgmenuconfig APM
2665e279b6c1SSam Ravnborg	tristate "APM (Advanced Power Management) BIOS support"
2666efefa6f6SIngo Molnar	depends on X86_32 && PM_SLEEP
2667a7f7f624SMasahiro Yamada	help
2668e279b6c1SSam Ravnborg	  APM is a BIOS specification for saving power using several different
2669e279b6c1SSam Ravnborg	  techniques. This is mostly useful for battery powered laptops with
2670e279b6c1SSam Ravnborg	  APM compliant BIOSes. If you say Y here, the system time will be
2671e279b6c1SSam Ravnborg	  reset after a RESUME operation, the /proc/apm device will provide
2672e279b6c1SSam Ravnborg	  battery status information, and user-space programs will receive
2673e279b6c1SSam Ravnborg	  notification of APM "events" (e.g. battery status change).
2674e279b6c1SSam Ravnborg
2675e279b6c1SSam Ravnborg	  If you select "Y" here, you can disable actual use of the APM
2676e279b6c1SSam Ravnborg	  BIOS by passing the "apm=off" option to the kernel at boot time.
2677e279b6c1SSam Ravnborg
2678e279b6c1SSam Ravnborg	  Note that the APM support is almost completely disabled for
2679e279b6c1SSam Ravnborg	  machines with more than one CPU.
2680e279b6c1SSam Ravnborg
2681e279b6c1SSam Ravnborg	  In order to use APM, you will need supporting software. For location
2682151f4e2bSMauro Carvalho Chehab	  and more information, read <file:Documentation/power/apm-acpi.rst>
26832dc98fd3SMichael Witten	  and the Battery Powered Linux mini-HOWTO, available from
2684e279b6c1SSam Ravnborg	  <http://www.tldp.org/docs.html#howto>.
2685e279b6c1SSam Ravnborg
2686e279b6c1SSam Ravnborg	  This driver does not spin down disk drives (see the hdparm(8)
2687e279b6c1SSam Ravnborg	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2688e279b6c1SSam Ravnborg	  VESA-compliant "green" monitors.
2689e279b6c1SSam Ravnborg
2690e279b6c1SSam Ravnborg	  This driver does not support the TI 4000M TravelMate and the ACER
2691e279b6c1SSam Ravnborg	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2692e279b6c1SSam Ravnborg	  desktop machines also don't have compliant BIOSes, and this driver
2693e279b6c1SSam Ravnborg	  may cause those machines to panic during the boot phase.
2694e279b6c1SSam Ravnborg
2695e279b6c1SSam Ravnborg	  Generally, if you don't have a battery in your machine, there isn't
2696e279b6c1SSam Ravnborg	  much point in using this driver and you should say N. If you get
2697e279b6c1SSam Ravnborg	  random kernel OOPSes or reboots that don't seem to be related to
2698e279b6c1SSam Ravnborg	  anything, try disabling/enabling this option (or disabling/enabling
2699e279b6c1SSam Ravnborg	  APM in your BIOS).
2700e279b6c1SSam Ravnborg
2701e279b6c1SSam Ravnborg	  Some other things you should try when experiencing seemingly random,
2702e279b6c1SSam Ravnborg	  "weird" problems:
2703e279b6c1SSam Ravnborg
2704e279b6c1SSam Ravnborg	  1) make sure that you have enough swap space and that it is
2705e279b6c1SSam Ravnborg	  enabled.
27067987448fSStephen Kitt	  2) pass the "idle=poll" option to the kernel
2707e279b6c1SSam Ravnborg	  3) switch on floating point emulation in the kernel and pass
2708e279b6c1SSam Ravnborg	  the "no387" option to the kernel
2709e279b6c1SSam Ravnborg	  4) pass the "floppy=nodma" option to the kernel
2710e279b6c1SSam Ravnborg	  5) pass the "mem=4M" option to the kernel (thereby disabling
2711e279b6c1SSam Ravnborg	  all but the first 4 MB of RAM)
2712e279b6c1SSam Ravnborg	  6) make sure that the CPU is not over clocked.
2713e279b6c1SSam Ravnborg	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2714e279b6c1SSam Ravnborg	  8) disable the cache from your BIOS settings
2715e279b6c1SSam Ravnborg	  9) install a fan for the video card or exchange video RAM
2716e279b6c1SSam Ravnborg	  10) install a better fan for the CPU
2717e279b6c1SSam Ravnborg	  11) exchange RAM chips
2718e279b6c1SSam Ravnborg	  12) exchange the motherboard.
2719e279b6c1SSam Ravnborg
2720e279b6c1SSam Ravnborg	  To compile this driver as a module, choose M here: the
2721e279b6c1SSam Ravnborg	  module will be called apm.
2722e279b6c1SSam Ravnborg
2723e279b6c1SSam Ravnborgif APM
2724e279b6c1SSam Ravnborg
2725e279b6c1SSam Ravnborgconfig APM_IGNORE_USER_SUSPEND
2726e279b6c1SSam Ravnborg	bool "Ignore USER SUSPEND"
2727a7f7f624SMasahiro Yamada	help
2728e279b6c1SSam Ravnborg	  This option will ignore USER SUSPEND requests. On machines with a
2729e279b6c1SSam Ravnborg	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2730e279b6c1SSam Ravnborg	  series notebooks, it is necessary to say Y because of a BIOS bug.
2731e279b6c1SSam Ravnborg
2732e279b6c1SSam Ravnborgconfig APM_DO_ENABLE
2733e279b6c1SSam Ravnborg	bool "Enable PM at boot time"
2734a7f7f624SMasahiro Yamada	help
2735e279b6c1SSam Ravnborg	  Enable APM features at boot time. From page 36 of the APM BIOS
2736e279b6c1SSam Ravnborg	  specification: "When disabled, the APM BIOS does not automatically
2737e279b6c1SSam Ravnborg	  power manage devices, enter the Standby State, enter the Suspend
2738e279b6c1SSam Ravnborg	  State, or take power saving steps in response to CPU Idle calls."
2739e279b6c1SSam Ravnborg	  This driver will make CPU Idle calls when Linux is idle (unless this
2740e279b6c1SSam Ravnborg	  feature is turned off -- see "Do CPU IDLE calls", below). This
2741e279b6c1SSam Ravnborg	  should always save battery power, but more complicated APM features
2742e279b6c1SSam Ravnborg	  will be dependent on your BIOS implementation. You may need to turn
2743e279b6c1SSam Ravnborg	  this option off if your computer hangs at boot time when using APM
2744e279b6c1SSam Ravnborg	  support, or if it beeps continuously instead of suspending. Turn
2745e279b6c1SSam Ravnborg	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2746e279b6c1SSam Ravnborg	  T400CDT. This is off by default since most machines do fine without
2747e279b6c1SSam Ravnborg	  this feature.
2748e279b6c1SSam Ravnborg
2749e279b6c1SSam Ravnborgconfig APM_CPU_IDLE
2750dd8af076SLen Brown	depends on CPU_IDLE
2751e279b6c1SSam Ravnborg	bool "Make CPU Idle calls when idle"
2752a7f7f624SMasahiro Yamada	help
2753e279b6c1SSam Ravnborg	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2754e279b6c1SSam Ravnborg	  On some machines, this can activate improved power savings, such as
2755e279b6c1SSam Ravnborg	  a slowed CPU clock rate, when the machine is idle. These idle calls
2756e279b6c1SSam Ravnborg	  are made after the idle loop has run for some length of time (e.g.,
2757e279b6c1SSam Ravnborg	  333 mS). On some machines, this will cause a hang at boot time or
2758e279b6c1SSam Ravnborg	  whenever the CPU becomes idle. (On machines with more than one CPU,
2759e279b6c1SSam Ravnborg	  this option does nothing.)
2760e279b6c1SSam Ravnborg
2761e279b6c1SSam Ravnborgconfig APM_DISPLAY_BLANK
2762e279b6c1SSam Ravnborg	bool "Enable console blanking using APM"
2763a7f7f624SMasahiro Yamada	help
2764e279b6c1SSam Ravnborg	  Enable console blanking using the APM. Some laptops can use this to
2765e279b6c1SSam Ravnborg	  turn off the LCD backlight when the screen blanker of the Linux
2766e279b6c1SSam Ravnborg	  virtual console blanks the screen. Note that this is only used by
2767e279b6c1SSam Ravnborg	  the virtual console screen blanker, and won't turn off the backlight
2768e279b6c1SSam Ravnborg	  when using the X Window system. This also doesn't have anything to
2769e279b6c1SSam Ravnborg	  do with your VESA-compliant power-saving monitor. Further, this
2770e279b6c1SSam Ravnborg	  option doesn't work for all laptops -- it might not turn off your
2771e279b6c1SSam Ravnborg	  backlight at all, or it might print a lot of errors to the console,
2772e279b6c1SSam Ravnborg	  especially if you are using gpm.
2773e279b6c1SSam Ravnborg
2774e279b6c1SSam Ravnborgconfig APM_ALLOW_INTS
2775e279b6c1SSam Ravnborg	bool "Allow interrupts during APM BIOS calls"
2776a7f7f624SMasahiro Yamada	help
2777e279b6c1SSam Ravnborg	  Normally we disable external interrupts while we are making calls to
2778e279b6c1SSam Ravnborg	  the APM BIOS as a measure to lessen the effects of a badly behaving
2779e279b6c1SSam Ravnborg	  BIOS implementation.  The BIOS should reenable interrupts if it
2780e279b6c1SSam Ravnborg	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2781e279b6c1SSam Ravnborg	  many of the newer IBM Thinkpads.  If you experience hangs when you
2782e279b6c1SSam Ravnborg	  suspend, try setting this to Y.  Otherwise, say N.
2783e279b6c1SSam Ravnborg
2784e279b6c1SSam Ravnborgendif # APM
2785e279b6c1SSam Ravnborg
2786bb0a56ecSDave Jonessource "drivers/cpufreq/Kconfig"
2787e279b6c1SSam Ravnborg
2788e279b6c1SSam Ravnborgsource "drivers/cpuidle/Kconfig"
2789e279b6c1SSam Ravnborg
279027471fdbSAndy Henroidsource "drivers/idle/Kconfig"
279127471fdbSAndy Henroid
2792e279b6c1SSam Ravnborgendmenu
2793e279b6c1SSam Ravnborg
2794e279b6c1SSam Ravnborgmenu "Bus options (PCI etc.)"
2795e279b6c1SSam Ravnborg
2796e279b6c1SSam Ravnborgchoice
2797e279b6c1SSam Ravnborg	prompt "PCI access mode"
2798efefa6f6SIngo Molnar	depends on X86_32 && PCI
2799e279b6c1SSam Ravnborg	default PCI_GOANY
2800a7f7f624SMasahiro Yamada	help
2801e279b6c1SSam Ravnborg	  On PCI systems, the BIOS can be used to detect the PCI devices and
2802e279b6c1SSam Ravnborg	  determine their configuration. However, some old PCI motherboards
2803e279b6c1SSam Ravnborg	  have BIOS bugs and may crash if this is done. Also, some embedded
2804e279b6c1SSam Ravnborg	  PCI-based systems don't have any BIOS at all. Linux can also try to
2805e279b6c1SSam Ravnborg	  detect the PCI hardware directly without using the BIOS.
2806e279b6c1SSam Ravnborg
2807e279b6c1SSam Ravnborg	  With this option, you can specify how Linux should detect the
2808e279b6c1SSam Ravnborg	  PCI devices. If you choose "BIOS", the BIOS will be used,
2809e279b6c1SSam Ravnborg	  if you choose "Direct", the BIOS won't be used, and if you
2810e279b6c1SSam Ravnborg	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2811e279b6c1SSam Ravnborg	  If you choose "Any", the kernel will try MMCONFIG, then the
2812e279b6c1SSam Ravnborg	  direct access method and falls back to the BIOS if that doesn't
2813e279b6c1SSam Ravnborg	  work. If unsure, go with the default, which is "Any".
2814e279b6c1SSam Ravnborg
2815e279b6c1SSam Ravnborgconfig PCI_GOBIOS
2816e279b6c1SSam Ravnborg	bool "BIOS"
2817e279b6c1SSam Ravnborg
2818e279b6c1SSam Ravnborgconfig PCI_GOMMCONFIG
2819e279b6c1SSam Ravnborg	bool "MMConfig"
2820e279b6c1SSam Ravnborg
2821e279b6c1SSam Ravnborgconfig PCI_GODIRECT
2822e279b6c1SSam Ravnborg	bool "Direct"
2823e279b6c1SSam Ravnborg
28243ef0e1f8SAndres Salomonconfig PCI_GOOLPC
282576fb6570SDaniel Drake	bool "OLPC XO-1"
28263ef0e1f8SAndres Salomon	depends on OLPC
28273ef0e1f8SAndres Salomon
28282bdd1b03SAndres Salomonconfig PCI_GOANY
28292bdd1b03SAndres Salomon	bool "Any"
28302bdd1b03SAndres Salomon
2831e279b6c1SSam Ravnborgendchoice
2832e279b6c1SSam Ravnborg
2833e279b6c1SSam Ravnborgconfig PCI_BIOS
28343c2362e6SHarvey Harrison	def_bool y
2835efefa6f6SIngo Molnar	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2836e279b6c1SSam Ravnborg
2837e279b6c1SSam Ravnborg# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2838e279b6c1SSam Ravnborgconfig PCI_DIRECT
28393c2362e6SHarvey Harrison	def_bool y
28400aba496fSShaohua Li	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2841e279b6c1SSam Ravnborg
2842e279b6c1SSam Ravnborgconfig PCI_MMCONFIG
2843b45c9f36SJan Kiszka	bool "Support mmconfig PCI config space access" if X86_64
2844b45c9f36SJan Kiszka	default y
28454590d98fSAndy Shevchenko	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2846b45c9f36SJan Kiszka	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2847e279b6c1SSam Ravnborg
28483ef0e1f8SAndres Salomonconfig PCI_OLPC
28492bdd1b03SAndres Salomon	def_bool y
28502bdd1b03SAndres Salomon	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
28513ef0e1f8SAndres Salomon
2852b5401a96SAlex Nixonconfig PCI_XEN
2853b5401a96SAlex Nixon	def_bool y
2854b5401a96SAlex Nixon	depends on PCI && XEN
2855b5401a96SAlex Nixon
28568364e1f8SJan Kiszkaconfig MMCONF_FAM10H
28578364e1f8SJan Kiszka	def_bool y
28588364e1f8SJan Kiszka	depends on X86_64 && PCI_MMCONFIG && ACPI
2859e279b6c1SSam Ravnborg
28603f6ea84aSIra W. Snyderconfig PCI_CNB20LE_QUIRK
28616a108a14SDavid Rientjes	bool "Read CNB20LE Host Bridge Windows" if EXPERT
28626ea30386SKees Cook	depends on PCI
28633f6ea84aSIra W. Snyder	help
28643f6ea84aSIra W. Snyder	  Read the PCI windows out of the CNB20LE host bridge. This allows
28653f6ea84aSIra W. Snyder	  PCI hotplug to work on systems with the CNB20LE chipset which do
28663f6ea84aSIra W. Snyder	  not have ACPI.
28673f6ea84aSIra W. Snyder
286864a5fed6SBjorn Helgaas	  There's no public spec for this chipset, and this functionality
286964a5fed6SBjorn Helgaas	  is known to be incomplete.
287064a5fed6SBjorn Helgaas
287164a5fed6SBjorn Helgaas	  You should say N unless you know you need this.
287264a5fed6SBjorn Helgaas
28733a495511SWilliam Breathitt Grayconfig ISA_BUS
287417a2a129SWilliam Breathitt Gray	bool "ISA bus support on modern systems" if EXPERT
28753a495511SWilliam Breathitt Gray	help
287617a2a129SWilliam Breathitt Gray	  Expose ISA bus device drivers and options available for selection and
287717a2a129SWilliam Breathitt Gray	  configuration. Enable this option if your target machine has an ISA
287817a2a129SWilliam Breathitt Gray	  bus. ISA is an older system, displaced by PCI and newer bus
287917a2a129SWilliam Breathitt Gray	  architectures -- if your target machine is modern, it probably does
288017a2a129SWilliam Breathitt Gray	  not have an ISA bus.
28813a495511SWilliam Breathitt Gray
28823a495511SWilliam Breathitt Gray	  If unsure, say N.
28833a495511SWilliam Breathitt Gray
28841c00f016SDavid Rientjes# x86_64 have no ISA slots, but can have ISA-style DMA.
2885e279b6c1SSam Ravnborgconfig ISA_DMA_API
28861c00f016SDavid Rientjes	bool "ISA-style DMA support" if (X86_64 && EXPERT)
28871c00f016SDavid Rientjes	default y
28881c00f016SDavid Rientjes	help
28891c00f016SDavid Rientjes	  Enables ISA-style DMA support for devices requiring such controllers.
28901c00f016SDavid Rientjes	  If unsure, say Y.
2891e279b6c1SSam Ravnborg
289251e68d05SLinus Torvaldsif X86_32
289351e68d05SLinus Torvalds
2894e279b6c1SSam Ravnborgconfig ISA
2895e279b6c1SSam Ravnborg	bool "ISA support"
2896a7f7f624SMasahiro Yamada	help
2897e279b6c1SSam Ravnborg	  Find out whether you have ISA slots on your motherboard.  ISA is the
2898e279b6c1SSam Ravnborg	  name of a bus system, i.e. the way the CPU talks to the other stuff
2899e279b6c1SSam Ravnborg	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2900e279b6c1SSam Ravnborg	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2901e279b6c1SSam Ravnborg	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2902e279b6c1SSam Ravnborg
2903e279b6c1SSam Ravnborgconfig SCx200
2904e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 support"
2905a7f7f624SMasahiro Yamada	help
2906e279b6c1SSam Ravnborg	  This provides basic support for National Semiconductor's
2907e279b6c1SSam Ravnborg	  (now AMD's) Geode processors.  The driver probes for the
2908e279b6c1SSam Ravnborg	  PCI-IDs of several on-chip devices, so its a good dependency
2909e279b6c1SSam Ravnborg	  for other scx200_* drivers.
2910e279b6c1SSam Ravnborg
2911e279b6c1SSam Ravnborg	  If compiled as a module, the driver is named scx200.
2912e279b6c1SSam Ravnborg
2913e279b6c1SSam Ravnborgconfig SCx200HR_TIMER
2914e279b6c1SSam Ravnborg	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2915592913ecSJohn Stultz	depends on SCx200
2916e279b6c1SSam Ravnborg	default y
2917a7f7f624SMasahiro Yamada	help
2918e279b6c1SSam Ravnborg	  This driver provides a clocksource built upon the on-chip
2919e279b6c1SSam Ravnborg	  27MHz high-resolution timer.  Its also a workaround for
2920e279b6c1SSam Ravnborg	  NSC Geode SC-1100's buggy TSC, which loses time when the
2921e279b6c1SSam Ravnborg	  processor goes idle (as is done by the scheduler).  The
2922e279b6c1SSam Ravnborg	  other workaround is idle=poll boot option.
2923e279b6c1SSam Ravnborg
29243ef0e1f8SAndres Salomonconfig OLPC
29253ef0e1f8SAndres Salomon	bool "One Laptop Per Child support"
292654008979SThomas Gleixner	depends on !X86_PAE
29273c554946SAndres Salomon	select GPIOLIB
2928dc3119e7SThomas Gleixner	select OF
292945bb1674SDaniel Drake	select OF_PROMTREE
2930b4e51854SGrant Likely	select IRQ_DOMAIN
29310c3d931bSLubomir Rintel	select OLPC_EC
2932a7f7f624SMasahiro Yamada	help
29333ef0e1f8SAndres Salomon	  Add support for detecting the unique features of the OLPC
29343ef0e1f8SAndres Salomon	  XO hardware.
29353ef0e1f8SAndres Salomon
2936a3128588SDaniel Drakeconfig OLPC_XO1_PM
2937a3128588SDaniel Drake	bool "OLPC XO-1 Power Management"
2938fa112cf1SBorislav Petkov	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2939a7f7f624SMasahiro Yamada	help
294097c4cb71SDaniel Drake	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2941bf1ebf00SDaniel Drake
2942cfee9597SDaniel Drakeconfig OLPC_XO1_RTC
2943cfee9597SDaniel Drake	bool "OLPC XO-1 Real Time Clock"
2944cfee9597SDaniel Drake	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2945a7f7f624SMasahiro Yamada	help
2946cfee9597SDaniel Drake	  Add support for the XO-1 real time clock, which can be used as a
2947cfee9597SDaniel Drake	  programmable wakeup source.
2948cfee9597SDaniel Drake
29497feda8e9SDaniel Drakeconfig OLPC_XO1_SCI
29507feda8e9SDaniel Drake	bool "OLPC XO-1 SCI extras"
295192e830f2SArnd Bergmann	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2952ed8e47feSRandy Dunlap	depends on INPUT=y
2953d8d01a63SDaniel Drake	select POWER_SUPPLY
2954a7f7f624SMasahiro Yamada	help
29557feda8e9SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1 laptop:
29567bc74b3dSDaniel Drake	   - EC-driven system wakeups
29577feda8e9SDaniel Drake	   - Power button
29587bc74b3dSDaniel Drake	   - Ebook switch
29592cf2baeaSDaniel Drake	   - Lid switch
2960e1040ac6SDaniel Drake	   - AC adapter status updates
2961e1040ac6SDaniel Drake	   - Battery status updates
29627feda8e9SDaniel Drake
2963a0f30f59SDaniel Drakeconfig OLPC_XO15_SCI
2964a0f30f59SDaniel Drake	bool "OLPC XO-1.5 SCI extras"
2965d8d01a63SDaniel Drake	depends on OLPC && ACPI
2966d8d01a63SDaniel Drake	select POWER_SUPPLY
2967a7f7f624SMasahiro Yamada	help
2968a0f30f59SDaniel Drake	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2969a0f30f59SDaniel Drake	   - EC-driven system wakeups
2970a0f30f59SDaniel Drake	   - AC adapter status updates
2971a0f30f59SDaniel Drake	   - Battery status updates
2972e279b6c1SSam Ravnborg
2973d4f3e350SEd Wildgooseconfig ALIX
2974d4f3e350SEd Wildgoose	bool "PCEngines ALIX System Support (LED setup)"
2975d4f3e350SEd Wildgoose	select GPIOLIB
2976a7f7f624SMasahiro Yamada	help
2977d4f3e350SEd Wildgoose	  This option enables system support for the PCEngines ALIX.
2978d4f3e350SEd Wildgoose	  At present this just sets up LEDs for GPIO control on
2979d4f3e350SEd Wildgoose	  ALIX2/3/6 boards.  However, other system specific setup should
2980d4f3e350SEd Wildgoose	  get added here.
2981d4f3e350SEd Wildgoose
2982d4f3e350SEd Wildgoose	  Note: You must still enable the drivers for GPIO and LED support
2983d4f3e350SEd Wildgoose	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2984d4f3e350SEd Wildgoose
2985d4f3e350SEd Wildgoose	  Note: You have to set alix.force=1 for boards with Award BIOS.
2986d4f3e350SEd Wildgoose
2987da4e3302SPhilip Prindevilleconfig NET5501
2988da4e3302SPhilip Prindeville	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2989da4e3302SPhilip Prindeville	select GPIOLIB
2990a7f7f624SMasahiro Yamada	help
2991da4e3302SPhilip Prindeville	  This option enables system support for the Soekris Engineering net5501.
2992da4e3302SPhilip Prindeville
29933197059aSPhilip A. Prindevilleconfig GEOS
29943197059aSPhilip A. Prindeville	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
29953197059aSPhilip A. Prindeville	select GPIOLIB
29963197059aSPhilip A. Prindeville	depends on DMI
2997a7f7f624SMasahiro Yamada	help
29983197059aSPhilip A. Prindeville	  This option enables system support for the Traverse Technologies GEOS.
29993197059aSPhilip A. Prindeville
30007d029125SVivien Didelotconfig TS5500
30017d029125SVivien Didelot	bool "Technologic Systems TS-5500 platform support"
30027d029125SVivien Didelot	depends on MELAN
30037d029125SVivien Didelot	select CHECK_SIGNATURE
30047d029125SVivien Didelot	select NEW_LEDS
30057d029125SVivien Didelot	select LEDS_CLASS
3006a7f7f624SMasahiro Yamada	help
30077d029125SVivien Didelot	  This option enables system support for the Technologic Systems TS-5500.
30087d029125SVivien Didelot
3009e279b6c1SSam Ravnborgendif # X86_32
3010e279b6c1SSam Ravnborg
301123ac4ae8SAndreas Herrmannconfig AMD_NB
3012e279b6c1SSam Ravnborg	def_bool y
30130e152cd7SBorislav Petkov	depends on CPU_SUP_AMD && PCI
3014e279b6c1SSam Ravnborg
3015e279b6c1SSam Ravnborgendmenu
3016e279b6c1SSam Ravnborg
30171572497cSChristoph Hellwigmenu "Binary Emulations"
3018e279b6c1SSam Ravnborg
3019e279b6c1SSam Ravnborgconfig IA32_EMULATION
3020e279b6c1SSam Ravnborg	bool "IA32 Emulation"
3021e279b6c1SSam Ravnborg	depends on X86_64
302239f88911SIngo Molnar	select ARCH_WANT_OLD_COMPAT_IPC
3023d1603990SRandy Dunlap	select BINFMT_ELF
302439f88911SIngo Molnar	select COMPAT_OLD_SIGACTION
3025a7f7f624SMasahiro Yamada	help
30265fd92e65SH. J. Lu	  Include code to run legacy 32-bit programs under a
30275fd92e65SH. J. Lu	  64-bit kernel. You should likely turn this on, unless you're
30285fd92e65SH. J. Lu	  100% sure that you don't have any 32-bit programs left.
3029e279b6c1SSam Ravnborg
303083a44a4fSMasahiro Yamadaconfig X86_X32_ABI
30316ea30386SKees Cook	bool "x32 ABI for 64-bit mode"
30329b54050bSBrian Gerst	depends on X86_64
3033aaeed6ecSNathan Chancellor	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3034aaeed6ecSNathan Chancellor	# compressed debug sections to x86_x32 properly:
3035aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/514
3036aaeed6ecSNathan Chancellor	# https://github.com/ClangBuiltLinux/linux/issues/1141
3037aaeed6ecSNathan Chancellor	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3038a7f7f624SMasahiro Yamada	help
30395fd92e65SH. J. Lu	  Include code to run binaries for the x32 native 32-bit ABI
30405fd92e65SH. J. Lu	  for 64-bit processors.  An x32 process gets access to the
30415fd92e65SH. J. Lu	  full 64-bit register file and wide data path while leaving
30425fd92e65SH. J. Lu	  pointers at 32 bits for smaller memory footprint.
30435fd92e65SH. J. Lu
3044953fee1dSIngo Molnarconfig COMPAT_32
3045953fee1dSIngo Molnar	def_bool y
3046953fee1dSIngo Molnar	depends on IA32_EMULATION || X86_32
3047953fee1dSIngo Molnar	select HAVE_UID16
3048953fee1dSIngo Molnar	select OLD_SIGSUSPEND3
3049953fee1dSIngo Molnar
3050e279b6c1SSam Ravnborgconfig COMPAT
30513c2362e6SHarvey Harrison	def_bool y
305283a44a4fSMasahiro Yamada	depends on IA32_EMULATION || X86_X32_ABI
3053e279b6c1SSam Ravnborg
3054e279b6c1SSam Ravnborgconfig COMPAT_FOR_U64_ALIGNMENT
30553120e25eSJan Beulich	def_bool y
3056a9251280SLinus Torvalds	depends on COMPAT
3057ee009e4aSDavid Howells
3058e279b6c1SSam Ravnborgendmenu
3059e279b6c1SSam Ravnborg
3060e5beae16SKeith Packardconfig HAVE_ATOMIC_IOMAP
3061e5beae16SKeith Packard	def_bool y
3062e5beae16SKeith Packard	depends on X86_32
3063e5beae16SKeith Packard
3064edf88417SAvi Kivitysource "arch/x86/kvm/Kconfig"
30655e8ebd84SJason A. Donenfeld
30665e8ebd84SJason A. Donenfeldsource "arch/x86/Kconfig.assembler"
3067