Kconfig 39 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310
  1. config ARM64
  2. def_bool y
  3. select ACPI_CCA_REQUIRED if ACPI
  4. select ACPI_GENERIC_GSI if ACPI
  5. select ACPI_REDUCED_HARDWARE_ONLY if ACPI
  6. select ACPI_MCFG if ACPI
  7. select ACPI_SPCR_TABLE if ACPI
  8. select ARCH_CLOCKSOURCE_DATA
  9. select ARCH_HAS_DEVMEM_IS_ALLOWED
  10. select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
  11. select ARCH_HAS_ELF_RANDOMIZE
  12. select ARCH_HAS_FORTIFY_SOURCE
  13. select ARCH_HAS_GCOV_PROFILE_ALL
  14. select ARCH_HAS_GIGANTIC_PAGE
  15. select ARCH_HAS_KCOV
  16. select ARCH_HAS_SG_CHAIN
  17. select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
  18. select ARCH_USE_CMPXCHG_LOCKREF
  19. select ARCH_SUPPORTS_LTO_CLANG
  20. select ARCH_SUPPORTS_SHADOW_CALL_STACK
  21. select ARCH_SUPPORTS_ATOMIC_RMW
  22. select ARCH_SUPPORTS_NUMA_BALANCING
  23. select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
  24. select ARCH_WANT_FRAME_POINTERS
  25. select ARCH_HAS_UBSAN_SANITIZE_ALL
  26. select ARM_AMBA
  27. select ARM_ARCH_TIMER
  28. select HAVE_KERNEL_GZIP
  29. select HAVE_KERNEL_LZ4
  30. select ARM_GIC
  31. select AUDIT_ARCH_COMPAT_GENERIC
  32. select ARM_GIC_V2M if PCI
  33. select ARM_GIC_V3
  34. select ARM_GIC_V3_ITS if PCI
  35. select ARM_PSCI_FW
  36. select BUILDTIME_EXTABLE_SORT
  37. select CLONE_BACKWARDS
  38. select COMMON_CLK if !ARCH_QCOM
  39. select CPU_PM if (SUSPEND || CPU_IDLE)
  40. select DCACHE_WORD_ACCESS
  41. select EDAC_SUPPORT
  42. select FRAME_POINTER
  43. select GENERIC_ALLOCATOR
  44. select GENERIC_CLOCKEVENTS
  45. select GENERIC_CLOCKEVENTS_BROADCAST
  46. select GENERIC_CPU_AUTOPROBE
  47. select GENERIC_EARLY_IOREMAP
  48. select GENERIC_IDLE_POLL_SETUP
  49. select GENERIC_IRQ_PROBE
  50. select GENERIC_IRQ_SHOW
  51. select GENERIC_IRQ_SHOW_LEVEL
  52. select GENERIC_PCI_IOMAP
  53. select GENERIC_SCHED_CLOCK
  54. select GENERIC_SMP_IDLE_THREAD
  55. select GENERIC_STRNCPY_FROM_USER
  56. select GENERIC_STRNLEN_USER
  57. select GENERIC_TIME_VSYSCALL
  58. select HANDLE_DOMAIN_IRQ
  59. select HARDIRQS_SW_RESEND
  60. select HAVE_ALIGNED_STRUCT_PAGE if SLUB
  61. select HAVE_ARCH_AUDITSYSCALL
  62. select HAVE_ARCH_BITREVERSE
  63. select HAVE_ARCH_HARDENED_USERCOPY
  64. select HAVE_ARCH_HUGE_VMAP
  65. select HAVE_ARCH_JUMP_LABEL
  66. select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48)
  67. select HAVE_ARCH_KGDB
  68. select HAVE_ARCH_MMAP_RND_BITS
  69. select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
  70. select HAVE_ARCH_SECCOMP_FILTER
  71. select HAVE_ARCH_TRACEHOOK
  72. select HAVE_ARCH_TRANSPARENT_HUGEPAGE
  73. select HAVE_ARCH_VMAP_STACK
  74. select HAVE_ARM_SMCCC
  75. select HAVE_EBPF_JIT
  76. select HAVE_C_RECORDMCOUNT
  77. select HAVE_CC_STACKPROTECTOR
  78. select HAVE_CMPXCHG_DOUBLE
  79. select HAVE_CMPXCHG_LOCAL
  80. select HAVE_CONTEXT_TRACKING
  81. select HAVE_DEBUG_BUGVERBOSE
  82. select HAVE_DEBUG_KMEMLEAK
  83. select HAVE_DMA_API_DEBUG
  84. select HAVE_DMA_CONTIGUOUS
  85. select HAVE_DYNAMIC_FTRACE
  86. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  87. select HAVE_FTRACE_MCOUNT_RECORD
  88. select HAVE_FUNCTION_TRACER
  89. select HAVE_FUNCTION_GRAPH_TRACER
  90. select HAVE_GCC_PLUGINS
  91. select HAVE_GENERIC_DMA_COHERENT
  92. select HAVE_HW_BREAKPOINT if PERF_EVENTS
  93. select HAVE_IRQ_TIME_ACCOUNTING
  94. select HAVE_MEMBLOCK
  95. select HAVE_MEMBLOCK_NODE_MAP if NUMA
  96. select HAVE_PATA_PLATFORM
  97. select HAVE_PERF_EVENTS
  98. select HAVE_PERF_REGS
  99. select HAVE_PERF_USER_STACK_DUMP
  100. select HAVE_REGS_AND_STACK_ACCESS_API
  101. select HAVE_RCU_TABLE_FREE
  102. select HAVE_SYSCALL_TRACEPOINTS
  103. select HAVE_KPROBES
  104. select HAVE_KRETPROBES if HAVE_KPROBES
  105. select IOMMU_DMA if IOMMU_SUPPORT
  106. select IRQ_DOMAIN
  107. select IRQ_FORCED_THREADING
  108. select MODULES_USE_ELF_RELA
  109. select NO_BOOTMEM
  110. select OF
  111. select OF_EARLY_FLATTREE
  112. select OF_RESERVED_MEM
  113. select PCI_ECAM if ACPI
  114. select POWER_RESET
  115. select POWER_SUPPLY
  116. select SPARSE_IRQ
  117. select SYSCTL_EXCEPTION_TRACE
  118. select THREAD_INFO_IN_TASK
  119. help
  120. ARM 64-bit (AArch64) Linux support.
  121. config 64BIT
  122. def_bool y
  123. config ARCH_PHYS_ADDR_T_64BIT
  124. def_bool y
  125. config MMU
  126. def_bool y
  127. config DEBUG_RODATA
  128. def_bool y
  129. config ARM64_PAGE_SHIFT
  130. int
  131. default 16 if ARM64_64K_PAGES
  132. default 14 if ARM64_16K_PAGES
  133. default 12
  134. config ARM64_CONT_SHIFT
  135. int
  136. default 5 if ARM64_64K_PAGES
  137. default 7 if ARM64_16K_PAGES
  138. default 4
  139. config ARCH_MMAP_RND_BITS_MIN
  140. default 14 if ARM64_64K_PAGES
  141. default 16 if ARM64_16K_PAGES
  142. default 18
  143. # max bits determined by the following formula:
  144. # VA_BITS - PAGE_SHIFT - 3
  145. config ARCH_MMAP_RND_BITS_MAX
  146. default 19 if ARM64_VA_BITS=36
  147. default 24 if ARM64_VA_BITS=39
  148. default 27 if ARM64_VA_BITS=42
  149. default 30 if ARM64_VA_BITS=47
  150. default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES
  151. default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES
  152. default 33 if ARM64_VA_BITS=48
  153. default 14 if ARM64_64K_PAGES
  154. default 16 if ARM64_16K_PAGES
  155. default 18
  156. config ARCH_MMAP_RND_COMPAT_BITS_MIN
  157. default 7 if ARM64_64K_PAGES
  158. default 9 if ARM64_16K_PAGES
  159. default 11
  160. config ARCH_MMAP_RND_COMPAT_BITS_MAX
  161. default 16
  162. config NO_IOPORT_MAP
  163. def_bool y if !PCI
  164. config ILLEGAL_POINTER_VALUE
  165. hex
  166. default 0xdead000000000000
  167. config STACKTRACE_SUPPORT
  168. def_bool y
  169. config ILLEGAL_POINTER_VALUE
  170. hex
  171. default 0xdead000000000000
  172. config LOCKDEP_SUPPORT
  173. def_bool y
  174. config TRACE_IRQFLAGS_SUPPORT
  175. def_bool y
  176. config RWSEM_XCHGADD_ALGORITHM
  177. def_bool y
  178. config GENERIC_BUG
  179. def_bool y
  180. depends on BUG
  181. config GENERIC_BUG_RELATIVE_POINTERS
  182. def_bool y
  183. depends on GENERIC_BUG
  184. config GENERIC_HWEIGHT
  185. def_bool y
  186. config GENERIC_CSUM
  187. def_bool y
  188. config GENERIC_CALIBRATE_DELAY
  189. def_bool y
  190. config ZONE_DMA
  191. def_bool y
  192. config HAVE_GENERIC_RCU_GUP
  193. def_bool y
  194. config ARCH_DMA_ADDR_T_64BIT
  195. def_bool y
  196. config NEED_DMA_MAP_STATE
  197. def_bool y
  198. config NEED_SG_DMA_LENGTH
  199. def_bool y
  200. config SMP
  201. def_bool y
  202. config SWIOTLB
  203. def_bool y
  204. config IOMMU_HELPER
  205. def_bool SWIOTLB
  206. config KERNEL_MODE_NEON
  207. def_bool y
  208. config FIX_EARLYCON_MEM
  209. def_bool y
  210. config PGTABLE_LEVELS
  211. int
  212. default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
  213. default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
  214. default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
  215. default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
  216. default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
  217. default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
  218. source "init/Kconfig"
  219. source "kernel/Kconfig.freezer"
  220. source "arch/arm64/Kconfig.platforms"
  221. menu "Bus support"
  222. config PCI
  223. bool "PCI support"
  224. help
  225. This feature enables support for PCI bus system. If you say Y
  226. here, the kernel will include drivers and infrastructure code
  227. to support PCI bus devices.
  228. config PCI_DOMAINS
  229. def_bool PCI
  230. config PCI_DOMAINS_GENERIC
  231. def_bool PCI
  232. config PCI_SYSCALL
  233. def_bool PCI
  234. source "drivers/pci/Kconfig"
  235. endmenu
  236. menu "Kernel Features"
  237. menu "ARM errata workarounds via the alternatives framework"
  238. config ARM64_ERRATUM_826319
  239. bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted"
  240. default y
  241. help
  242. This option adds an alternative code sequence to work around ARM
  243. erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or
  244. AXI master interface and an L2 cache.
  245. If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors
  246. and is unable to accept a certain write via this interface, it will
  247. not progress on read data presented on the read data channel and the
  248. system can deadlock.
  249. The workaround promotes data cache clean instructions to
  250. data cache clean-and-invalidate.
  251. Please note that this does not necessarily enable the workaround,
  252. as it depends on the alternative framework, which will only patch
  253. the kernel if an affected CPU is detected.
  254. If unsure, say Y.
  255. config ARM64_ERRATUM_827319
  256. bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
  257. default y
  258. help
  259. This option adds an alternative code sequence to work around ARM
  260. erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
  261. master interface and an L2 cache.
  262. Under certain conditions this erratum can cause a clean line eviction
  263. to occur at the same time as another transaction to the same address
  264. on the AMBA 5 CHI interface, which can cause data corruption if the
  265. interconnect reorders the two transactions.
  266. The workaround promotes data cache clean instructions to
  267. data cache clean-and-invalidate.
  268. Please note that this does not necessarily enable the workaround,
  269. as it depends on the alternative framework, which will only patch
  270. the kernel if an affected CPU is detected.
  271. If unsure, say Y.
  272. config ARM64_ERRATUM_824069
  273. bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
  274. default y
  275. help
  276. This option adds an alternative code sequence to work around ARM
  277. erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
  278. to a coherent interconnect.
  279. If a Cortex-A53 processor is executing a store or prefetch for
  280. write instruction at the same time as a processor in another
  281. cluster is executing a cache maintenance operation to the same
  282. address, then this erratum might cause a clean cache line to be
  283. incorrectly marked as dirty.
  284. The workaround promotes data cache clean instructions to
  285. data cache clean-and-invalidate.
  286. Please note that this option does not necessarily enable the
  287. workaround, as it depends on the alternative framework, which will
  288. only patch the kernel if an affected CPU is detected.
  289. If unsure, say Y.
  290. config ARM64_ERRATUM_819472
  291. bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
  292. default y
  293. help
  294. This option adds an alternative code sequence to work around ARM
  295. erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
  296. present when it is connected to a coherent interconnect.
  297. If the processor is executing a load and store exclusive sequence at
  298. the same time as a processor in another cluster is executing a cache
  299. maintenance operation to the same address, then this erratum might
  300. cause data corruption.
  301. The workaround promotes data cache clean instructions to
  302. data cache clean-and-invalidate.
  303. Please note that this does not necessarily enable the workaround,
  304. as it depends on the alternative framework, which will only patch
  305. the kernel if an affected CPU is detected.
  306. If unsure, say Y.
  307. config ARM64_ERRATUM_832075
  308. bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
  309. default y
  310. help
  311. This option adds an alternative code sequence to work around ARM
  312. erratum 832075 on Cortex-A57 parts up to r1p2.
  313. Affected Cortex-A57 parts might deadlock when exclusive load/store
  314. instructions to Write-Back memory are mixed with Device loads.
  315. The workaround is to promote device loads to use Load-Acquire
  316. semantics.
  317. Please note that this does not necessarily enable the workaround,
  318. as it depends on the alternative framework, which will only patch
  319. the kernel if an affected CPU is detected.
  320. If unsure, say Y.
  321. config ARM64_ERRATUM_834220
  322. bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault"
  323. depends on KVM
  324. default y
  325. help
  326. This option adds an alternative code sequence to work around ARM
  327. erratum 834220 on Cortex-A57 parts up to r1p2.
  328. Affected Cortex-A57 parts might report a Stage 2 translation
  329. fault as the result of a Stage 1 fault for load crossing a
  330. page boundary when there is a permission or device memory
  331. alignment fault at Stage 1 and a translation fault at Stage 2.
  332. The workaround is to verify that the Stage 1 translation
  333. doesn't generate a fault before handling the Stage 2 fault.
  334. Please note that this does not necessarily enable the workaround,
  335. as it depends on the alternative framework, which will only patch
  336. the kernel if an affected CPU is detected.
  337. If unsure, say Y.
  338. config ARM64_ERRATUM_845719
  339. bool "Cortex-A53: 845719: a load might read incorrect data"
  340. depends on COMPAT
  341. default y
  342. help
  343. This option adds an alternative code sequence to work around ARM
  344. erratum 845719 on Cortex-A53 parts up to r0p4.
  345. When running a compat (AArch32) userspace on an affected Cortex-A53
  346. part, a load at EL0 from a virtual address that matches the bottom 32
  347. bits of the virtual address used by a recent load at (AArch64) EL1
  348. might return incorrect data.
  349. The workaround is to write the contextidr_el1 register on exception
  350. return to a 32-bit task.
  351. Please note that this does not necessarily enable the workaround,
  352. as it depends on the alternative framework, which will only patch
  353. the kernel if an affected CPU is detected.
  354. If unsure, say Y.
  355. config ARM64_ERRATUM_843419
  356. bool "Cortex-A53: 843419: A load or store might access an incorrect address"
  357. default y if !LTO_CLANG
  358. select ARM64_MODULE_CMODEL_LARGE if MODULES
  359. help
  360. This option links the kernel with '--fix-cortex-a53-843419' and
  361. builds modules using the large memory model in order to avoid the use
  362. of the ADRP instruction, which can cause a subsequent memory access
  363. to use an incorrect address on Cortex-A53 parts up to r0p4.
  364. If unsure, say Y.
  365. config ARM64_ERRATUM_1024718
  366. bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
  367. default y
  368. help
  369. This option adds work around for Arm Cortex-A55 Erratum 1024718.
  370. Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
  371. update of the hardware dirty bit when the DBM/AP bits are updated
  372. without a break-before-make. The work around is to disable the usage
  373. of hardware DBM locally on the affected cores. CPUs not affected by
  374. erratum will continue to use the feature.
  375. If unsure, say Y.
  376. config CAVIUM_ERRATUM_22375
  377. bool "Cavium erratum 22375, 24313"
  378. default y
  379. help
  380. Enable workaround for erratum 22375, 24313.
  381. This implements two gicv3-its errata workarounds for ThunderX. Both
  382. with small impact affecting only ITS table allocation.
  383. erratum 22375: only alloc 8MB table size
  384. erratum 24313: ignore memory access type
  385. The fixes are in ITS initialization and basically ignore memory access
  386. type and table size provided by the TYPER and BASER registers.
  387. If unsure, say Y.
  388. config CAVIUM_ERRATUM_23144
  389. bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
  390. depends on NUMA
  391. default y
  392. help
  393. ITS SYNC command hang for cross node io and collections/cpu mapping.
  394. If unsure, say Y.
  395. config CAVIUM_ERRATUM_23154
  396. bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
  397. default y
  398. help
  399. The gicv3 of ThunderX requires a modified version for
  400. reading the IAR status to ensure data synchronization
  401. (access to icc_iar1_el1 is not sync'ed before and after).
  402. If unsure, say Y.
  403. config CAVIUM_ERRATUM_27456
  404. bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption"
  405. default y
  406. help
  407. On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
  408. instructions may cause the icache to become corrupted if it
  409. contains data for a non-current ASID. The fix is to
  410. invalidate the icache when changing the mm context.
  411. If unsure, say Y.
  412. config QCOM_QDF2400_ERRATUM_0065
  413. bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size"
  414. default y
  415. help
  416. On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports
  417. ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have
  418. been indicated as 16Bytes (0xf), not 8Bytes (0x7).
  419. If unsure, say Y.
  420. endmenu
  421. choice
  422. prompt "Page size"
  423. default ARM64_4K_PAGES
  424. help
  425. Page size (translation granule) configuration.
  426. config ARM64_4K_PAGES
  427. bool "4KB"
  428. help
  429. This feature enables 4KB pages support.
  430. config ARM64_16K_PAGES
  431. bool "16KB"
  432. help
  433. The system will use 16KB pages support. AArch32 emulation
  434. requires applications compiled with 16K (or a multiple of 16K)
  435. aligned segments.
  436. config ARM64_64K_PAGES
  437. bool "64KB"
  438. help
  439. This feature enables 64KB pages support (4KB by default)
  440. allowing only two levels of page tables and faster TLB
  441. look-up. AArch32 emulation requires applications compiled
  442. with 64K aligned segments.
  443. endchoice
  444. choice
  445. prompt "Virtual address space size"
  446. default ARM64_VA_BITS_39 if ARM64_4K_PAGES
  447. default ARM64_VA_BITS_47 if ARM64_16K_PAGES
  448. default ARM64_VA_BITS_42 if ARM64_64K_PAGES
  449. help
  450. Allows choosing one of multiple possible virtual address
  451. space sizes. The level of translation table is determined by
  452. a combination of page size and virtual address space size.
  453. config ARM64_VA_BITS_36
  454. bool "36-bit" if EXPERT
  455. depends on ARM64_16K_PAGES
  456. config ARM64_VA_BITS_39
  457. bool "39-bit"
  458. depends on ARM64_4K_PAGES
  459. config ARM64_VA_BITS_42
  460. bool "42-bit"
  461. depends on ARM64_64K_PAGES
  462. config ARM64_VA_BITS_47
  463. bool "47-bit"
  464. depends on ARM64_16K_PAGES
  465. config ARM64_VA_BITS_48
  466. bool "48-bit"
  467. endchoice
  468. config ARM64_VA_BITS
  469. int
  470. default 36 if ARM64_VA_BITS_36
  471. default 39 if ARM64_VA_BITS_39
  472. default 42 if ARM64_VA_BITS_42
  473. default 47 if ARM64_VA_BITS_47
  474. default 48 if ARM64_VA_BITS_48
  475. config CPU_BIG_ENDIAN
  476. bool "Build big-endian kernel"
  477. help
  478. Say Y if you plan on running a kernel in big-endian mode.
  479. config SCHED_MC
  480. bool "Multi-core scheduler support"
  481. help
  482. Multi-core scheduler support improves the CPU scheduler's decision
  483. making when dealing with multi-core CPU chips at a cost of slightly
  484. increased overhead in some places. If unsure say N here.
  485. config SCHED_SMT
  486. bool "SMT scheduler support"
  487. help
  488. Improves the CPU scheduler's decision making when dealing with
  489. MultiThreading at a cost of slightly increased overhead in some
  490. places. If unsure say N here.
  491. config NR_CPUS
  492. int "Maximum number of CPUs (2-4096)"
  493. range 2 4096
  494. # These have to remain sorted largest to smallest
  495. default "64"
  496. config HOTPLUG_CPU
  497. bool "Support for hot-pluggable CPUs"
  498. select GENERIC_IRQ_MIGRATION
  499. help
  500. Say Y here to experiment with turning CPUs off and on. CPUs
  501. can be controlled through /sys/devices/system/cpu.
  502. # The GPIO number here must be sorted by descending number. In case of
  503. # a multiplatform kernel, we just want the highest value required by the
  504. # selected platforms.
  505. config ARCH_NR_GPIO
  506. int
  507. default 1280 if ARCH_QCOM
  508. default 256
  509. help
  510. Maximum number of GPIOs in the system.
  511. If unsure, leave the default value.
  512. # Common NUMA Features
  513. config NUMA
  514. bool "Numa Memory Allocation and Scheduler Support"
  515. select ACPI_NUMA if ACPI
  516. select OF_NUMA
  517. help
  518. Enable NUMA (Non Uniform Memory Access) support.
  519. The kernel will try to allocate memory used by a CPU on the
  520. local memory of the CPU and add some more
  521. NUMA awareness to the kernel.
  522. config NODES_SHIFT
  523. int "Maximum NUMA Nodes (as a power of 2)"
  524. range 1 10
  525. default "2"
  526. depends on NEED_MULTIPLE_NODES
  527. help
  528. Specify the maximum number of NUMA Nodes available on the target
  529. system. Increases memory reserved to accommodate various tables.
  530. config USE_PERCPU_NUMA_NODE_ID
  531. def_bool y
  532. depends on NUMA
  533. config HAVE_SETUP_PER_CPU_AREA
  534. def_bool y
  535. depends on NUMA
  536. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  537. def_bool y
  538. depends on NUMA
  539. source kernel/Kconfig.preempt
  540. source kernel/Kconfig.hz
  541. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  542. def_bool y
  543. config ARCH_HAS_HOLES_MEMORYMODEL
  544. def_bool y if SPARSEMEM
  545. config ARCH_SPARSEMEM_ENABLE
  546. def_bool y
  547. select SPARSEMEM_VMEMMAP_ENABLE
  548. config ARCH_SPARSEMEM_DEFAULT
  549. def_bool ARCH_SPARSEMEM_ENABLE
  550. config ARCH_SELECT_MEMORY_MODEL
  551. def_bool ARCH_SPARSEMEM_ENABLE
  552. config HAVE_ARCH_PFN_VALID
  553. def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
  554. config HW_PERF_EVENTS
  555. def_bool y
  556. depends on ARM_PMU
  557. config SYS_SUPPORTS_HUGETLBFS
  558. def_bool y
  559. config ARCH_WANT_HUGE_PMD_SHARE
  560. def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
  561. config ARCH_HAS_CACHE_LINE_SIZE
  562. def_bool y
  563. source "mm/Kconfig"
  564. config ARM64_DMA_USE_IOMMU
  565. bool "ARM64 DMA iommu integration"
  566. select ARM_HAS_SG_CHAIN
  567. select NEED_SG_DMA_LENGTH
  568. help
  569. Enable using iommu through the standard dma apis.
  570. dma_alloc_coherent() will allocate scatter-gather memory
  571. which is made virtually contiguous via iommu.
  572. Enable if system contains IOMMU hardware.
  573. if ARM64_DMA_USE_IOMMU
  574. config ARM64_DMA_IOMMU_ALIGNMENT
  575. int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
  576. range 4 9
  577. default 9
  578. help
  579. DMA mapping framework by default aligns all buffers to the smallest
  580. PAGE_SIZE order which is greater than or equal to the requested buffer
  581. size. This works well for buffers up to a few hundreds kilobytes, but
  582. for larger buffers it just a waste of address space. Drivers which has
  583. relatively small addressing window (like 64Mib) might run out of
  584. virtual space with just a few allocations.
  585. With this parameter you can specify the maximum PAGE_SIZE order for
  586. DMA IOMMU buffers. Larger buffers will be aligned only to this
  587. specified order. The order is expressed as a power of two multiplied
  588. by the PAGE_SIZE.
  589. endif
  590. config SECCOMP
  591. bool "Enable seccomp to safely compute untrusted bytecode"
  592. ---help---
  593. This kernel feature is useful for number crunching applications
  594. that may need to compute untrusted bytecode during their
  595. execution. By using pipes or other transports made available to
  596. the process as file descriptors supporting the read/write
  597. syscalls, it's possible to isolate those applications in
  598. their own address space using seccomp. Once seccomp is
  599. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  600. and the task is only allowed to execute a few safe syscalls
  601. defined by each seccomp mode.
  602. config PARAVIRT
  603. bool "Enable paravirtualization code"
  604. help
  605. This changes the kernel so it can modify itself when it is run
  606. under a hypervisor, potentially improving performance significantly
  607. over full virtualization.
  608. config PARAVIRT_TIME_ACCOUNTING
  609. bool "Paravirtual steal time accounting"
  610. select PARAVIRT
  611. default n
  612. help
  613. Select this option to enable fine granularity task steal time
  614. accounting. Time spent executing other tasks in parallel with
  615. the current vCPU is discounted from the vCPU power. To account for
  616. that, there can be a small performance impact.
  617. If in doubt, say N here.
  618. config KEXEC
  619. depends on PM_SLEEP_SMP
  620. select KEXEC_CORE
  621. bool "kexec system call"
  622. ---help---
  623. kexec is a system call that implements the ability to shutdown your
  624. current kernel, and to start another kernel. It is like a reboot
  625. but it is independent of the system firmware. And like a reboot
  626. you can start any kernel with it, not just Linux.
  627. config XEN_DOM0
  628. def_bool y
  629. depends on XEN
  630. config XEN
  631. bool "Xen guest support on ARM64"
  632. depends on ARM64 && OF
  633. select SWIOTLB_XEN
  634. select PARAVIRT
  635. help
  636. Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64.
  637. config FORCE_MAX_ZONEORDER
  638. int
  639. default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE)
  640. default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE)
  641. default "11"
  642. help
  643. The kernel memory allocator divides physically contiguous memory
  644. blocks into "zones", where each zone is a power of two number of
  645. pages. This option selects the largest power of two that the kernel
  646. keeps in the memory allocator. If you need to allocate very large
  647. blocks of physically contiguous memory, then you may need to
  648. increase this value.
  649. This config option is actually maximum order plus one. For example,
  650. a value of 11 means that the largest free memory block is 2^10 pages.
  651. We make sure that we can allocate upto a HugePage size for each configuration.
  652. Hence we have :
  653. MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2
  654. However for 4K, we choose a higher default value, 11 as opposed to 10, giving us
  655. 4M allocations matching the default size used by generic code.
  656. config UNMAP_KERNEL_AT_EL0
  657. bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
  658. default y
  659. help
  660. Speculation attacks against some high-performance processors can
  661. be used to bypass MMU permission checks and leak kernel data to
  662. userspace. This can be defended against by unmapping the kernel
  663. when running in userspace, mapping it back in on exception entry
  664. via a trampoline page in the vector table.
  665. If unsure, say Y.
  666. config HARDEN_BRANCH_PREDICTOR
  667. bool "Harden the branch predictor against aliasing attacks" if EXPERT
  668. help
  669. Speculation attacks against some high-performance processors rely on
  670. being able to manipulate the branch predictor for a victim context by
  671. executing aliasing branches in the attacker context. Such attacks
  672. can be partially mitigated against by clearing internal branch
  673. predictor state and limiting the prediction logic in some situations.
  674. This config option will take CPU-specific actions to harden the
  675. branch predictor against aliasing attacks and may rely on specific
  676. instruction sequences or control bits being set by the system
  677. firmware.
  678. If unsure, say Y.
  679. config PSCI_BP_HARDENING
  680. depends on HARDEN_BRANCH_PREDICTOR
  681. bool "Use PSCI get version to enable branch predictor hardening"
  682. help
  683. If the mitigation for branch prediction is supported using psci
  684. get version by the firmware then enable this option. Some older
  685. versions of firmwares may not be using new SMCCC convention in
  686. such cases use psci get version method to enable hardening for
  687. branch prediction attacks.
  688. If unsure, say N.
  689. config ARM64_SSBD
  690. bool "Speculative Store Bypass Disable" if EXPERT
  691. default y
  692. help
  693. This enables mitigation of the bypassing of previous stores
  694. by speculative loads.
  695. If unsure, say Y.
  696. menuconfig ARMV8_DEPRECATED
  697. bool "Emulate deprecated/obsolete ARMv8 instructions"
  698. depends on COMPAT
  699. help
  700. Legacy software support may require certain instructions
  701. that have been deprecated or obsoleted in the architecture.
  702. Enable this config to enable selective emulation of these
  703. features.
  704. If unsure, say Y
  705. if ARMV8_DEPRECATED
  706. config SWP_EMULATION
  707. bool "Emulate SWP/SWPB instructions"
  708. help
  709. ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that
  710. they are always undefined. Say Y here to enable software
  711. emulation of these instructions for userspace using LDXR/STXR.
  712. In some older versions of glibc [<=2.8] SWP is used during futex
  713. trylock() operations with the assumption that the code will not
  714. be preempted. This invalid assumption may be more likely to fail
  715. with SWP emulation enabled, leading to deadlock of the user
  716. application.
  717. NOTE: when accessing uncached shared regions, LDXR/STXR rely
  718. on an external transaction monitoring block called a global
  719. monitor to maintain update atomicity. If your system does not
  720. implement a global monitor, this option can cause programs that
  721. perform SWP operations to uncached memory to deadlock.
  722. If unsure, say Y
  723. config CP15_BARRIER_EMULATION
  724. bool "Emulate CP15 Barrier instructions"
  725. help
  726. The CP15 barrier instructions - CP15ISB, CP15DSB, and
  727. CP15DMB - are deprecated in ARMv8 (and ARMv7). It is
  728. strongly recommended to use the ISB, DSB, and DMB
  729. instructions instead.
  730. Say Y here to enable software emulation of these
  731. instructions for AArch32 userspace code. When this option is
  732. enabled, CP15 barrier usage is traced which can help
  733. identify software that needs updating.
  734. If unsure, say Y
  735. config SETEND_EMULATION
  736. bool "Emulate SETEND instruction"
  737. help
  738. The SETEND instruction alters the data-endianness of the
  739. AArch32 EL0, and is deprecated in ARMv8.
  740. Say Y here to enable software emulation of the instruction
  741. for AArch32 userspace code.
  742. Note: All the cpus on the system must have mixed endian support at EL0
  743. for this feature to be enabled. If a new CPU - which doesn't support mixed
  744. endian - is hotplugged in after this feature has been enabled, there could
  745. be unexpected results in the applications.
  746. If unsure, say Y
  747. endif
  748. config ARM64_SW_TTBR0_PAN
  749. bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
  750. help
  751. Enabling this option prevents the kernel from accessing
  752. user-space memory directly by pointing TTBR0_EL1 to a reserved
  753. zeroed area and reserved ASID. The user access routines
  754. restore the valid TTBR0_EL1 temporarily.
  755. menu "ARMv8.1 architectural features"
  756. config ARM64_HW_AFDBM
  757. bool "Support for hardware updates of the Access and Dirty page flags"
  758. default y
  759. help
  760. The ARMv8.1 architecture extensions introduce support for
  761. hardware updates of the access and dirty information in page
  762. table entries. When enabled in TCR_EL1 (HA and HD bits) on
  763. capable processors, accesses to pages with PTE_AF cleared will
  764. set this bit instead of raising an access flag fault.
  765. Similarly, writes to read-only pages with the DBM bit set will
  766. clear the read-only bit (AP[2]) instead of raising a
  767. permission fault.
  768. Kernels built with this configuration option enabled continue
  769. to work on pre-ARMv8.1 hardware and the performance impact is
  770. minimal. If unsure, say Y.
  771. config ARM64_PAN
  772. bool "Enable support for Privileged Access Never (PAN)"
  773. default y
  774. help
  775. Privileged Access Never (PAN; part of the ARMv8.1 Extensions)
  776. prevents the kernel or hypervisor from accessing user-space (EL0)
  777. memory directly.
  778. Choosing this option will cause any unprotected (not using
  779. copy_to_user et al) memory access to fail with a permission fault.
  780. The feature is detected at runtime, and will remain as a 'nop'
  781. instruction if the cpu does not implement the feature.
  782. config ARM64_LSE_ATOMICS
  783. bool "Atomic instructions"
  784. help
  785. As part of the Large System Extensions, ARMv8.1 introduces new
  786. atomic instructions that are designed specifically to scale in
  787. very large systems.
  788. Say Y here to make use of these instructions for the in-kernel
  789. atomic routines. This incurs a small overhead on CPUs that do
  790. not support these instructions and requires the kernel to be
  791. built with binutils >= 2.25.
  792. config ARM64_VHE
  793. bool "Enable support for Virtualization Host Extensions (VHE)"
  794. default y
  795. help
  796. Virtualization Host Extensions (VHE) allow the kernel to run
  797. directly at EL2 (instead of EL1) on processors that support
  798. it. This leads to better performance for KVM, as they reduce
  799. the cost of the world switch.
  800. Selecting this option allows the VHE feature to be detected
  801. at runtime, and does not affect processors that do not
  802. implement this feature.
  803. endmenu
  804. menu "ARMv8.2 architectural features"
  805. config ARM64_UAO
  806. bool "Enable support for User Access Override (UAO)"
  807. default y
  808. help
  809. User Access Override (UAO; part of the ARMv8.2 Extensions)
  810. causes the 'unprivileged' variant of the load/store instructions to
  811. be overriden to be privileged.
  812. This option changes get_user() and friends to use the 'unprivileged'
  813. variant of the load/store instructions. This ensures that user-space
  814. really did have access to the supplied memory. When addr_limit is
  815. set to kernel memory the UAO bit will be set, allowing privileged
  816. access to kernel memory.
  817. Choosing this option will cause copy_to_user() et al to use user-space
  818. memory permissions.
  819. The feature is detected at runtime, the kernel will use the
  820. regular load/store instructions if the cpu does not implement the
  821. feature.
  822. endmenu
  823. config ARM64_MODULE_CMODEL_LARGE
  824. bool
  825. config ARM64_MODULE_PLTS
  826. bool
  827. select ARM64_MODULE_CMODEL_LARGE
  828. select HAVE_MOD_ARCH_SPECIFIC
  829. config RELOCATABLE
  830. bool
  831. help
  832. This builds the kernel as a Position Independent Executable (PIE),
  833. which retains all relocation metadata required to relocate the
  834. kernel binary at runtime to a different virtual address than the
  835. address it was linked at.
  836. Since AArch64 uses the RELA relocation format, this requires a
  837. relocation pass at runtime even if the kernel is loaded at the
  838. same address it was linked at.
  839. config RANDOMIZE_BASE
  840. bool "Randomize the address of the kernel image"
  841. select ARM64_MODULE_PLTS if MODULES
  842. select RELOCATABLE
  843. help
  844. Randomizes the virtual address at which the kernel image is
  845. loaded, as a security feature that deters exploit attempts
  846. relying on knowledge of the location of kernel internals.
  847. It is the bootloader's job to provide entropy, by passing a
  848. random u64 value in /chosen/kaslr-seed at kernel entry.
  849. When booting via the UEFI stub, it will invoke the firmware's
  850. EFI_RNG_PROTOCOL implementation (if available) to supply entropy
  851. to the kernel proper. In addition, it will randomise the physical
  852. location of the kernel Image as well.
  853. If unsure, say N.
  854. config RANDOMIZE_MODULE_REGION_FULL
  855. bool "Randomize the module region independently from the core kernel"
  856. depends on RANDOMIZE_BASE && !DYNAMIC_FTRACE && !LTO_CLANG
  857. default y
  858. help
  859. Randomizes the location of the module region without considering the
  860. location of the core kernel. This way, it is impossible for modules
  861. to leak information about the location of core kernel data structures
  862. but it does imply that function calls between modules and the core
  863. kernel will need to be resolved via veneers in the module PLT.
  864. When this option is not set, the module region will be randomized over
  865. a limited range that contains the [_stext, _etext] interval of the
  866. core kernel, so branch relocations are always in range.
  867. endmenu
  868. menu "Boot options"
  869. config ARM64_ACPI_PARKING_PROTOCOL
  870. bool "Enable support for the ARM64 ACPI parking protocol"
  871. depends on ACPI
  872. help
  873. Enable support for the ARM64 ACPI parking protocol. If disabled
  874. the kernel will not allow booting through the ARM64 ACPI parking
  875. protocol even if the corresponding data is present in the ACPI
  876. MADT table.
  877. config CMDLINE
  878. string "Default kernel command string"
  879. default ""
  880. help
  881. Provide a set of default command-line options at build time by
  882. entering them here. As a minimum, you should specify the the
  883. root device (e.g. root=/dev/nfs).
  884. choice
  885. prompt "Kernel command line type" if CMDLINE != ""
  886. default CMDLINE_FROM_BOOTLOADER
  887. config CMDLINE_FROM_BOOTLOADER
  888. bool "Use bootloader kernel arguments if available"
  889. help
  890. Uses the command-line options passed by the boot loader. If
  891. the boot loader doesn't provide any, the default kernel command
  892. string provided in CMDLINE will be used.
  893. config CMDLINE_EXTEND
  894. bool "Extend bootloader kernel arguments"
  895. help
  896. The command-line arguments provided by the boot loader will be
  897. appended to the default kernel command string.
  898. config CMDLINE_FORCE
  899. bool "Always use the default kernel command string"
  900. help
  901. Always use the default kernel command string, even if the boot
  902. loader passes other arguments to the kernel.
  903. This is useful if you cannot or don't want to change the
  904. command-line options your boot loader passes to the kernel.
  905. endchoice
  906. config EFI_STUB
  907. bool
  908. config EFI
  909. bool "UEFI runtime support"
  910. depends on OF && !CPU_BIG_ENDIAN
  911. select LIBFDT
  912. select UCS2_STRING
  913. select EFI_PARAMS_FROM_FDT
  914. select EFI_RUNTIME_WRAPPERS
  915. select EFI_STUB
  916. select EFI_ARMSTUB
  917. default y
  918. help
  919. This option provides support for runtime services provided
  920. by UEFI firmware (such as non-volatile variables, realtime
  921. clock, and platform reset). A UEFI stub is also provided to
  922. allow the kernel to be booted as an EFI application. This
  923. is only useful on systems that have UEFI firmware.
  924. config DMI
  925. bool "Enable support for SMBIOS (DMI) tables"
  926. depends on EFI
  927. default y
  928. help
  929. This enables SMBIOS/DMI feature for systems.
  930. This option is only useful on systems that have UEFI firmware.
  931. However, even with this option, the resultant kernel should
  932. continue to boot on existing non-UEFI platforms.
  933. config BUILD_ARM64_APPENDED_DTB_IMAGE
  934. bool "Build a concatenated Image.gz/dtb by default"
  935. depends on OF
  936. help
  937. Enabling this option will cause a concatenated Image.gz and list of
  938. DTBs to be built by default (instead of a standalone Image.gz.)
  939. The image will built in arch/arm64/boot/Image.gz-dtb
  940. config BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES
  941. string "Default dtb names"
  942. depends on BUILD_ARM64_APPENDED_DTB_IMAGE
  943. help
  944. Space separated list of names of dtbs to append when
  945. building a concatenated Image.gz-dtb.
  946. config BUILD_ARM64_DTC
  947. string "dtc to use"
  948. config BUILD_ARM64_DTC_FLAGS
  949. string "extra dtc flags"
  950. config BUILD_ARM64_APPLY_DTBO
  951. bool "apply device tree overlay"
  952. config BUILD_ARM64_DT_OVERLAY
  953. bool "enable DT overlay compilation support"
  954. depends on OF
  955. help
  956. This option enables support for DT overlay compilation.
  957. endmenu
  958. menu "Userspace binary formats"
  959. source "fs/Kconfig.binfmt"
  960. config COMPAT
  961. bool "Kernel support for 32-bit EL0"
  962. depends on ARM64_4K_PAGES || EXPERT
  963. select COMPAT_BINFMT_ELF if BINFMT_ELF
  964. select HAVE_UID16
  965. select OLD_SIGSUSPEND3
  966. select COMPAT_OLD_SIGACTION
  967. help
  968. This option enables support for a 32-bit EL0 running under a 64-bit
  969. kernel at EL1. AArch32-specific components such as system calls,
  970. the user helper functions, VFP support and the ptrace interface are
  971. handled appropriately by the kernel.
  972. If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware
  973. that you will only be able to execute AArch32 binaries that were compiled
  974. with page size aligned segments.
  975. If you want to execute 32-bit userspace applications, say Y.
  976. config KUSER_HELPERS
  977. bool "Enable the kuser helpers page in 32-bit processes"
  978. depends on COMPAT
  979. default y
  980. help
  981. Warning: disabling this option may break 32-bit applications.
  982. Provide kuser helpers in a special purpose fixed-address page. The
  983. kernel provides helper code to userspace in read-only form at a fixed
  984. location to allow userspace to be independent of the CPU type fitted
  985. to the system. This permits 32-bit binaries to be run on ARMv6 through
  986. to ARMv8 without modification.
  987. See Documentation/arm/kernel_user_helpers.txt for details.
  988. However, the fixed-address nature of these helpers can be used by ROP
  989. (return-orientated programming) authors when creating exploits.
  990. If all of the 32-bit binaries and libraries that run on your platform
  991. are built specifically for your platform, and make no use of these
  992. helpers, then you can turn this option off to hinder such exploits.
  993. However, in that case, if a binary or library relying on those helpers
  994. is run, it will receive a SIGSEGV signal, which will terminate the
  995. program. Typically, binaries compiled for ARMv7 or later do not use
  996. the kuser helpers.
  997. Say N here only if you are absolutely certain that you do not need
  998. these helpers; otherwise, the safe option is to say Y (the default
  999. for now)
  1000. config SYSVIPC_COMPAT
  1001. def_bool y
  1002. depends on COMPAT && SYSVIPC
  1003. config KEYS_COMPAT
  1004. def_bool y
  1005. depends on COMPAT && KEYS
  1006. config COMPAT_VDSO
  1007. bool "32-bit vDSO"
  1008. depends on COMPAT
  1009. select ARM_ARCH_TIMER_VCT_ACCESS
  1010. default n
  1011. help
  1012. Warning: a 32-bit toolchain is necessary to build the vDSO. You
  1013. must explicitly define which toolchain should be used by setting
  1014. CROSS_COMPILE_ARM32 to the prefix of the 32-bit toolchain (same format
  1015. as CROSS_COMPILE). If CROSS_COMPILE_ARM32 is empty, a warning will be
  1016. printed and the kernel will be built as if COMPAT_VDSO had not been
  1017. set. If CROSS_COMPILE_ARM32 is set to an invalid prefix, compilation
  1018. will be aborted.
  1019. Provide a vDSO to 32-bit processes. It includes the symbols provided
  1020. by the vDSO from the 32-bit kernel, so that a 32-bit libc can use
  1021. the compat vDSO without modification. It also provides sigreturn
  1022. trampolines, replacing the sigreturn page.
  1023. config CROSS_COMPILE_ARM32
  1024. string "32-bit toolchain prefix"
  1025. help
  1026. Same as setting CROSS_COMPILE_ARM32 in the environment, but saved for
  1027. future builds. The environment variable overrides this config option.
  1028. endmenu
  1029. menu "Power management options"
  1030. source "kernel/power/Kconfig"
  1031. config ARCH_HIBERNATION_POSSIBLE
  1032. def_bool y
  1033. depends on CPU_PM
  1034. config ARCH_HIBERNATION_HEADER
  1035. def_bool y
  1036. depends on HIBERNATION
  1037. config ARCH_SUSPEND_POSSIBLE
  1038. def_bool y
  1039. endmenu
  1040. menu "CPU Power Management"
  1041. source "drivers/cpuidle/Kconfig"
  1042. source "drivers/cpufreq/Kconfig"
  1043. endmenu
  1044. source "net/Kconfig"
  1045. source "drivers/Kconfig"
  1046. source "drivers/firmware/Kconfig"
  1047. source "drivers/acpi/Kconfig"
  1048. source "fs/Kconfig"
  1049. source "arch/arm64/kvm/Kconfig"
  1050. source "arch/arm64/Kconfig.debug"
  1051. source "security/Kconfig"
  1052. source "crypto/Kconfig"
  1053. if CRYPTO
  1054. source "arch/arm64/crypto/Kconfig"
  1055. endif
  1056. source "lib/Kconfig"