Kconfig 58 KB

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  1. # SPDX-License-Identifier: GPL-2.0
  2. config ARM
  3. bool
  4. default y
  5. select ARCH_32BIT_OFF_T
  6. select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND
  7. select ARCH_HAS_BINFMT_FLAT
  8. select ARCH_HAS_CPU_CACHE_ALIASING
  9. select ARCH_HAS_CPU_FINALIZE_INIT if MMU
  10. select ARCH_HAS_CURRENT_STACK_POINTER
  11. select ARCH_HAS_DEBUG_VIRTUAL if MMU
  12. select ARCH_HAS_DMA_ALLOC if MMU
  13. select ARCH_HAS_DMA_OPS
  14. select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
  15. select ARCH_HAS_ELF_RANDOMIZE
  16. select ARCH_HAS_FORTIFY_SOURCE
  17. select ARCH_HAS_KEEPINITRD
  18. select ARCH_HAS_KCOV
  19. select ARCH_HAS_MEMBARRIER_SYNC_CORE
  20. select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
  21. select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
  22. select ARCH_HAS_SETUP_DMA_OPS
  23. select ARCH_HAS_SET_MEMORY
  24. select ARCH_STACKWALK
  25. select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
  26. select ARCH_HAS_STRICT_MODULE_RWX if MMU
  27. select ARCH_HAS_SYNC_DMA_FOR_DEVICE
  28. select ARCH_HAS_SYNC_DMA_FOR_CPU
  29. select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
  30. select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
  31. select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
  32. select ARCH_HAS_GCOV_PROFILE_ALL
  33. select ARCH_KEEP_MEMBLOCK
  34. select ARCH_HAS_UBSAN
  35. select ARCH_MIGHT_HAVE_PC_PARPORT
  36. select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
  37. select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
  38. select ARCH_NEED_CMPXCHG_1_EMU if CPU_V6
  39. select ARCH_SUPPORTS_ATOMIC_RMW
  40. select ARCH_SUPPORTS_CFI_CLANG
  41. select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
  42. select ARCH_SUPPORTS_PER_VMA_LOCK
  43. select ARCH_USE_BUILTIN_BSWAP
  44. select ARCH_USE_CMPXCHG_LOCKREF
  45. select ARCH_USE_MEMTEST
  46. select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
  47. select ARCH_WANT_GENERAL_HUGETLB
  48. select ARCH_WANT_IPC_PARSE_VERSION
  49. select ARCH_WANT_LD_ORPHAN_WARN
  50. select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
  51. select BUILDTIME_TABLE_SORT if MMU
  52. select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE)
  53. select CLONE_BACKWARDS
  54. select CPU_PM if SUSPEND || CPU_IDLE
  55. select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
  56. select DMA_DECLARE_COHERENT
  57. select DMA_GLOBAL_POOL if !MMU
  58. select DMA_NONCOHERENT_MMAP if MMU
  59. select EDAC_SUPPORT
  60. select EDAC_ATOMIC_SCRUB
  61. select GENERIC_ALLOCATOR
  62. select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
  63. select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
  64. select GENERIC_CLOCKEVENTS_BROADCAST if SMP
  65. select GENERIC_IRQ_IPI if SMP
  66. select GENERIC_CPU_AUTOPROBE
  67. select GENERIC_CPU_DEVICES
  68. select GENERIC_EARLY_IOREMAP
  69. select GENERIC_IDLE_POLL_SETUP
  70. select GENERIC_IRQ_MULTI_HANDLER
  71. select GENERIC_IRQ_PROBE
  72. select GENERIC_IRQ_SHOW
  73. select GENERIC_IRQ_SHOW_LEVEL
  74. select GENERIC_LIB_DEVMEM_IS_ALLOWED
  75. select GENERIC_PCI_IOMAP
  76. select GENERIC_SCHED_CLOCK
  77. select GENERIC_SMP_IDLE_THREAD
  78. select HARDIRQS_SW_RESEND
  79. select HAS_IOPORT
  80. select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
  81. select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
  82. select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  83. select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL
  84. select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
  85. select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
  86. select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
  87. select HAVE_ARCH_MMAP_RND_BITS if MMU
  88. select HAVE_ARCH_PFN_VALID
  89. select HAVE_ARCH_SECCOMP
  90. select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
  91. select HAVE_ARCH_STACKLEAK
  92. select HAVE_ARCH_THREAD_STRUCT_WHITELIST
  93. select HAVE_ARCH_TRACEHOOK
  94. select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
  95. select HAVE_ARM_SMCCC if CPU_V7
  96. select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
  97. select HAVE_CONTEXT_TRACKING_USER
  98. select HAVE_C_RECORDMCOUNT
  99. select HAVE_BUILDTIME_MCOUNT_SORT
  100. select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
  101. select HAVE_DMA_CONTIGUOUS if MMU
  102. select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  103. select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
  104. select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
  105. select HAVE_EXIT_THREAD
  106. select HAVE_GUP_FAST if ARM_LPAE
  107. select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
  108. select HAVE_FUNCTION_ERROR_INJECTION
  109. select HAVE_FUNCTION_GRAPH_TRACER
  110. select HAVE_FUNCTION_TRACER if !XIP_KERNEL
  111. select HAVE_GCC_PLUGINS
  112. select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
  113. select HAVE_IRQ_TIME_ACCOUNTING
  114. select HAVE_KERNEL_GZIP
  115. select HAVE_KERNEL_LZ4
  116. select HAVE_KERNEL_LZMA
  117. select HAVE_KERNEL_LZO
  118. select HAVE_KERNEL_XZ
  119. select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
  120. select HAVE_KRETPROBES if HAVE_KPROBES
  121. select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD) && LD_CAN_USE_KEEP_IN_OVERLAY
  122. select HAVE_MOD_ARCH_SPECIFIC
  123. select HAVE_NMI
  124. select HAVE_OPTPROBES if !THUMB2_KERNEL
  125. select HAVE_PAGE_SIZE_4KB
  126. select HAVE_PCI if MMU
  127. select HAVE_PERF_EVENTS
  128. select HAVE_PERF_REGS
  129. select HAVE_PERF_USER_STACK_DUMP
  130. select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
  131. select HAVE_REGS_AND_STACK_ACCESS_API
  132. select HAVE_RSEQ
  133. select HAVE_STACKPROTECTOR
  134. select HAVE_SYSCALL_TRACEPOINTS
  135. select HAVE_UID16
  136. select HAVE_VIRT_CPU_ACCOUNTING_GEN
  137. select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
  138. select IRQ_FORCED_THREADING
  139. select LOCK_MM_AND_FIND_VMA
  140. select MODULES_USE_ELF_REL
  141. select NEED_DMA_MAP_STATE
  142. select OF_EARLY_FLATTREE if OF
  143. select OLD_SIGACTION
  144. select OLD_SIGSUSPEND3
  145. select PCI_DOMAINS_GENERIC if PCI
  146. select PCI_SYSCALL if PCI
  147. select PERF_USE_VMALLOC
  148. select RTC_LIB
  149. select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC)
  150. select SYS_SUPPORTS_APM_EMULATION
  151. select THREAD_INFO_IN_TASK
  152. select TIMER_OF if OF
  153. select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS
  154. select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
  155. select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
  156. # Above selects are sorted alphabetically; please add new ones
  157. # according to that. Thanks.
  158. help
  159. The ARM series is a line of low-power-consumption RISC chip designs
  160. licensed by ARM Ltd and targeted at embedded applications and
  161. handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
  162. manufactured, but legacy ARM-based PC hardware remains popular in
  163. Europe. There is an ARM Linux project with a web page at
  164. <http://www.arm.linux.org.uk/>.
  165. config ARM_HAS_GROUP_RELOCS
  166. def_bool y
  167. depends on !LD_IS_LLD || LLD_VERSION >= 140000
  168. depends on !COMPILE_TEST
  169. help
  170. Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
  171. relocations, which have been around for a long time, but were not
  172. supported in LLD until version 14. The combined range is -/+ 256 MiB,
  173. which is usually sufficient, but not for allyesconfig, so we disable
  174. this feature when doing compile testing.
  175. config ARM_DMA_USE_IOMMU
  176. bool
  177. select NEED_SG_DMA_LENGTH
  178. if ARM_DMA_USE_IOMMU
  179. config ARM_DMA_IOMMU_ALIGNMENT
  180. int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
  181. range 4 9
  182. default 8
  183. help
  184. DMA mapping framework by default aligns all buffers to the smallest
  185. PAGE_SIZE order which is greater than or equal to the requested buffer
  186. size. This works well for buffers up to a few hundreds kilobytes, but
  187. for larger buffers it just a waste of address space. Drivers which has
  188. relatively small addressing window (like 64Mib) might run out of
  189. virtual space with just a few allocations.
  190. With this parameter you can specify the maximum PAGE_SIZE order for
  191. DMA IOMMU buffers. Larger buffers will be aligned only to this
  192. specified order. The order is expressed as a power of two multiplied
  193. by the PAGE_SIZE.
  194. endif
  195. config SYS_SUPPORTS_APM_EMULATION
  196. bool
  197. config HAVE_TCM
  198. bool
  199. select GENERIC_ALLOCATOR
  200. config HAVE_PROC_CPU
  201. bool
  202. config NO_IOPORT_MAP
  203. bool
  204. config SBUS
  205. bool
  206. config STACKTRACE_SUPPORT
  207. bool
  208. default y
  209. config LOCKDEP_SUPPORT
  210. bool
  211. default y
  212. config ARCH_HAS_ILOG2_U32
  213. bool
  214. config ARCH_HAS_ILOG2_U64
  215. bool
  216. config ARCH_HAS_BANDGAP
  217. bool
  218. config FIX_EARLYCON_MEM
  219. def_bool y if MMU
  220. config GENERIC_HWEIGHT
  221. bool
  222. default y
  223. config GENERIC_CALIBRATE_DELAY
  224. bool
  225. default y
  226. config ARCH_MAY_HAVE_PC_FDC
  227. bool
  228. config ARCH_SUPPORTS_UPROBES
  229. def_bool y
  230. config GENERIC_ISA_DMA
  231. bool
  232. config FIQ
  233. bool
  234. config ARCH_MTD_XIP
  235. bool
  236. config ARM_PATCH_PHYS_VIRT
  237. bool "Patch physical to virtual translations at runtime" if !ARCH_MULTIPLATFORM
  238. default y
  239. depends on MMU
  240. help
  241. Patch phys-to-virt and virt-to-phys translation functions at
  242. boot and module load time according to the position of the
  243. kernel in system memory.
  244. This can only be used with non-XIP MMU kernels where the base
  245. of physical memory is at a 2 MiB boundary.
  246. Only disable this option if you know that you do not require
  247. this feature (eg, building a kernel for a single machine) and
  248. you need to shrink the kernel to the minimal size.
  249. config NEED_MACH_IO_H
  250. bool
  251. help
  252. Select this when mach/io.h is required to provide special
  253. definitions for this platform. The need for mach/io.h should
  254. be avoided when possible.
  255. config NEED_MACH_MEMORY_H
  256. bool
  257. help
  258. Select this when mach/memory.h is required to provide special
  259. definitions for this platform. The need for mach/memory.h should
  260. be avoided when possible.
  261. config PHYS_OFFSET
  262. hex "Physical address of main memory" if MMU
  263. depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
  264. default DRAM_BASE if !MMU
  265. default 0x00000000 if ARCH_FOOTBRIDGE
  266. default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
  267. default 0xa0000000 if ARCH_PXA
  268. default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
  269. default 0
  270. help
  271. Please provide the physical address corresponding to the
  272. location of main memory in your system.
  273. config GENERIC_BUG
  274. def_bool y
  275. depends on BUG
  276. config PGTABLE_LEVELS
  277. int
  278. default 3 if ARM_LPAE
  279. default 2
  280. menu "System Type"
  281. config MMU
  282. bool "MMU-based Paged Memory Management Support"
  283. default y
  284. help
  285. Select if you want MMU-based virtualised addressing space
  286. support by paged memory management. If unsure, say 'Y'.
  287. config ARM_SINGLE_ARMV7M
  288. def_bool !MMU
  289. select ARM_NVIC
  290. select CPU_V7M
  291. select NO_IOPORT_MAP
  292. config ARCH_MMAP_RND_BITS_MIN
  293. default 8
  294. config ARCH_MMAP_RND_BITS_MAX
  295. default 14 if PAGE_OFFSET=0x40000000
  296. default 15 if PAGE_OFFSET=0x80000000
  297. default 16
  298. config ARCH_MULTIPLATFORM
  299. bool "Require kernel to be portable to multiple machines" if EXPERT
  300. depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
  301. default y
  302. help
  303. In general, all Arm machines can be supported in a single
  304. kernel image, covering either Armv4/v5 or Armv6/v7.
  305. However, some configuration options require hardcoding machine
  306. specific physical addresses or enable errata workarounds that may
  307. break other machines.
  308. Selecting N here allows using those options, including
  309. DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
  310. source "arch/arm/Kconfig.platforms"
  311. #
  312. # This is sorted alphabetically by mach-* pathname. However, plat-*
  313. # Kconfigs may be included either alphabetically (according to the
  314. # plat- suffix) or along side the corresponding mach-* source.
  315. #
  316. source "arch/arm/mach-actions/Kconfig"
  317. source "arch/arm/mach-alpine/Kconfig"
  318. source "arch/arm/mach-artpec/Kconfig"
  319. source "arch/arm/mach-aspeed/Kconfig"
  320. source "arch/arm/mach-at91/Kconfig"
  321. source "arch/arm/mach-axxia/Kconfig"
  322. source "arch/arm/mach-bcm/Kconfig"
  323. source "arch/arm/mach-berlin/Kconfig"
  324. source "arch/arm/mach-clps711x/Kconfig"
  325. source "arch/arm/mach-davinci/Kconfig"
  326. source "arch/arm/mach-digicolor/Kconfig"
  327. source "arch/arm/mach-dove/Kconfig"
  328. source "arch/arm/mach-ep93xx/Kconfig"
  329. source "arch/arm/mach-exynos/Kconfig"
  330. source "arch/arm/mach-footbridge/Kconfig"
  331. source "arch/arm/mach-gemini/Kconfig"
  332. source "arch/arm/mach-highbank/Kconfig"
  333. source "arch/arm/mach-hisi/Kconfig"
  334. source "arch/arm/mach-hpe/Kconfig"
  335. source "arch/arm/mach-imx/Kconfig"
  336. source "arch/arm/mach-ixp4xx/Kconfig"
  337. source "arch/arm/mach-keystone/Kconfig"
  338. source "arch/arm/mach-lpc32xx/Kconfig"
  339. source "arch/arm/mach-mediatek/Kconfig"
  340. source "arch/arm/mach-meson/Kconfig"
  341. source "arch/arm/mach-milbeaut/Kconfig"
  342. source "arch/arm/mach-mmp/Kconfig"
  343. source "arch/arm/mach-mstar/Kconfig"
  344. source "arch/arm/mach-mv78xx0/Kconfig"
  345. source "arch/arm/mach-mvebu/Kconfig"
  346. source "arch/arm/mach-mxs/Kconfig"
  347. source "arch/arm/mach-nomadik/Kconfig"
  348. source "arch/arm/mach-npcm/Kconfig"
  349. source "arch/arm/mach-omap1/Kconfig"
  350. source "arch/arm/mach-omap2/Kconfig"
  351. source "arch/arm/mach-orion5x/Kconfig"
  352. source "arch/arm/mach-pxa/Kconfig"
  353. source "arch/arm/mach-qcom/Kconfig"
  354. source "arch/arm/mach-realtek/Kconfig"
  355. source "arch/arm/mach-rpc/Kconfig"
  356. source "arch/arm/mach-rockchip/Kconfig"
  357. source "arch/arm/mach-s3c/Kconfig"
  358. source "arch/arm/mach-s5pv210/Kconfig"
  359. source "arch/arm/mach-sa1100/Kconfig"
  360. source "arch/arm/mach-shmobile/Kconfig"
  361. source "arch/arm/mach-socfpga/Kconfig"
  362. source "arch/arm/mach-spear/Kconfig"
  363. source "arch/arm/mach-sti/Kconfig"
  364. source "arch/arm/mach-stm32/Kconfig"
  365. source "arch/arm/mach-sunxi/Kconfig"
  366. source "arch/arm/mach-tegra/Kconfig"
  367. source "arch/arm/mach-ux500/Kconfig"
  368. source "arch/arm/mach-versatile/Kconfig"
  369. source "arch/arm/mach-vt8500/Kconfig"
  370. source "arch/arm/mach-zynq/Kconfig"
  371. source "arch/arm/mach-arkmicro/Kconfig"
  372. # ARMv7-M architecture
  373. config ARCH_LPC18XX
  374. bool "NXP LPC18xx/LPC43xx"
  375. depends on ARM_SINGLE_ARMV7M
  376. select ARCH_HAS_RESET_CONTROLLER
  377. select ARM_AMBA
  378. select CLKSRC_LPC32XX
  379. select PINCTRL
  380. help
  381. Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
  382. high performance microcontrollers.
  383. config ARCH_MPS2
  384. bool "ARM MPS2 platform"
  385. depends on ARM_SINGLE_ARMV7M
  386. select ARM_AMBA
  387. select CLKSRC_MPS2
  388. help
  389. Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
  390. with a range of available cores like Cortex-M3/M4/M7.
  391. Please, note that depends which Application Note is used memory map
  392. for the platform may vary, so adjustment of RAM base might be needed.
  393. # Definitions to make life easier
  394. config ARCH_ACORN
  395. bool
  396. config PLAT_ORION
  397. bool
  398. select CLKSRC_MMIO
  399. select GENERIC_IRQ_CHIP
  400. select IRQ_DOMAIN
  401. config PLAT_ORION_LEGACY
  402. bool
  403. select PLAT_ORION
  404. config PLAT_VERSATILE
  405. bool
  406. source "arch/arm/mm/Kconfig"
  407. config IWMMXT
  408. bool "Enable iWMMXt support"
  409. depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
  410. default y if PXA27x || PXA3xx || ARCH_MMP
  411. help
  412. Enable support for iWMMXt context switching at run time if
  413. running on a CPU that supports it.
  414. if !MMU
  415. source "arch/arm/Kconfig-nommu"
  416. endif
  417. config PJ4B_ERRATA_4742
  418. bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
  419. depends on CPU_PJ4B && MACH_ARMADA_370
  420. default y
  421. help
  422. When coming out of either a Wait for Interrupt (WFI) or a Wait for
  423. Event (WFE) IDLE states, a specific timing sensitivity exists between
  424. the retiring WFI/WFE instructions and the newly issued subsequent
  425. instructions. This sensitivity can result in a CPU hang scenario.
  426. Workaround:
  427. The software must insert either a Data Synchronization Barrier (DSB)
  428. or Data Memory Barrier (DMB) command immediately after the WFI/WFE
  429. instruction
  430. config ARM_ERRATA_326103
  431. bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
  432. depends on CPU_V6
  433. help
  434. Executing a SWP instruction to read-only memory does not set bit 11
  435. of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
  436. treat the access as a read, preventing a COW from occurring and
  437. causing the faulting task to livelock.
  438. config ARM_ERRATA_411920
  439. bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
  440. depends on CPU_V6 || CPU_V6K
  441. help
  442. Invalidation of the Instruction Cache operation can
  443. fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
  444. It does not affect the MPCore. This option enables the ARM Ltd.
  445. recommended workaround.
  446. config ARM_ERRATA_430973
  447. bool "ARM errata: Stale prediction on replaced interworking branch"
  448. depends on CPU_V7
  449. help
  450. This option enables the workaround for the 430973 Cortex-A8
  451. r1p* erratum. If a code sequence containing an ARM/Thumb
  452. interworking branch is replaced with another code sequence at the
  453. same virtual address, whether due to self-modifying code or virtual
  454. to physical address re-mapping, Cortex-A8 does not recover from the
  455. stale interworking branch prediction. This results in Cortex-A8
  456. executing the new code sequence in the incorrect ARM or Thumb state.
  457. The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
  458. and also flushes the branch target cache at every context switch.
  459. Note that setting specific bits in the ACTLR register may not be
  460. available in non-secure mode.
  461. config ARM_ERRATA_458693
  462. bool "ARM errata: Processor deadlock when a false hazard is created"
  463. depends on CPU_V7
  464. depends on !ARCH_MULTIPLATFORM
  465. help
  466. This option enables the workaround for the 458693 Cortex-A8 (r2p0)
  467. erratum. For very specific sequences of memory operations, it is
  468. possible for a hazard condition intended for a cache line to instead
  469. be incorrectly associated with a different cache line. This false
  470. hazard might then cause a processor deadlock. The workaround enables
  471. the L1 caching of the NEON accesses and disables the PLD instruction
  472. in the ACTLR register. Note that setting specific bits in the ACTLR
  473. register may not be available in non-secure mode and thus is not
  474. available on a multiplatform kernel. This should be applied by the
  475. bootloader instead.
  476. config ARM_ERRATA_460075
  477. bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
  478. depends on CPU_V7
  479. depends on !ARCH_MULTIPLATFORM
  480. help
  481. This option enables the workaround for the 460075 Cortex-A8 (r2p0)
  482. erratum. Any asynchronous access to the L2 cache may encounter a
  483. situation in which recent store transactions to the L2 cache are lost
  484. and overwritten with stale memory contents from external memory. The
  485. workaround disables the write-allocate mode for the L2 cache via the
  486. ACTLR register. Note that setting specific bits in the ACTLR register
  487. may not be available in non-secure mode and thus is not available on
  488. a multiplatform kernel. This should be applied by the bootloader
  489. instead.
  490. config ARM_ERRATA_742230
  491. bool "ARM errata: DMB operation may be faulty"
  492. depends on CPU_V7 && SMP
  493. depends on !ARCH_MULTIPLATFORM
  494. help
  495. This option enables the workaround for the 742230 Cortex-A9
  496. (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
  497. between two write operations may not ensure the correct visibility
  498. ordering of the two writes. This workaround sets a specific bit in
  499. the diagnostic register of the Cortex-A9 which causes the DMB
  500. instruction to behave as a DSB, ensuring the correct behaviour of
  501. the two writes. Note that setting specific bits in the diagnostics
  502. register may not be available in non-secure mode and thus is not
  503. available on a multiplatform kernel. This should be applied by the
  504. bootloader instead.
  505. config ARM_ERRATA_742231
  506. bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
  507. depends on CPU_V7 && SMP
  508. depends on !ARCH_MULTIPLATFORM
  509. help
  510. This option enables the workaround for the 742231 Cortex-A9
  511. (r2p0..r2p2) erratum. Under certain conditions, specific to the
  512. Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
  513. accessing some data located in the same cache line, may get corrupted
  514. data due to bad handling of the address hazard when the line gets
  515. replaced from one of the CPUs at the same time as another CPU is
  516. accessing it. This workaround sets specific bits in the diagnostic
  517. register of the Cortex-A9 which reduces the linefill issuing
  518. capabilities of the processor. Note that setting specific bits in the
  519. diagnostics register may not be available in non-secure mode and thus
  520. is not available on a multiplatform kernel. This should be applied by
  521. the bootloader instead.
  522. config ARM_ERRATA_643719
  523. bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
  524. depends on CPU_V7 && SMP
  525. default y
  526. help
  527. This option enables the workaround for the 643719 Cortex-A9 (prior to
  528. r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
  529. register returns zero when it should return one. The workaround
  530. corrects this value, ensuring cache maintenance operations which use
  531. it behave as intended and avoiding data corruption.
  532. config ARM_ERRATA_720789
  533. bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
  534. depends on CPU_V7
  535. help
  536. This option enables the workaround for the 720789 Cortex-A9 (prior to
  537. r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
  538. broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
  539. As a consequence of this erratum, some TLB entries which should be
  540. invalidated are not, resulting in an incoherency in the system page
  541. tables. The workaround changes the TLB flushing routines to invalidate
  542. entries regardless of the ASID.
  543. config ARM_ERRATA_743622
  544. bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
  545. depends on CPU_V7
  546. depends on !ARCH_MULTIPLATFORM
  547. help
  548. This option enables the workaround for the 743622 Cortex-A9
  549. (r2p*) erratum. Under very rare conditions, a faulty
  550. optimisation in the Cortex-A9 Store Buffer may lead to data
  551. corruption. This workaround sets a specific bit in the diagnostic
  552. register of the Cortex-A9 which disables the Store Buffer
  553. optimisation, preventing the defect from occurring. This has no
  554. visible impact on the overall performance or power consumption of the
  555. processor. Note that setting specific bits in the diagnostics register
  556. may not be available in non-secure mode and thus is not available on a
  557. multiplatform kernel. This should be applied by the bootloader instead.
  558. config ARM_ERRATA_751472
  559. bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
  560. depends on CPU_V7
  561. depends on !ARCH_MULTIPLATFORM
  562. help
  563. This option enables the workaround for the 751472 Cortex-A9 (prior
  564. to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
  565. completion of a following broadcasted operation if the second
  566. operation is received by a CPU before the ICIALLUIS has completed,
  567. potentially leading to corrupted entries in the cache or TLB.
  568. Note that setting specific bits in the diagnostics register may
  569. not be available in non-secure mode and thus is not available on
  570. a multiplatform kernel. This should be applied by the bootloader
  571. instead.
  572. config ARM_ERRATA_754322
  573. bool "ARM errata: possible faulty MMU translations following an ASID switch"
  574. depends on CPU_V7
  575. help
  576. This option enables the workaround for the 754322 Cortex-A9 (r2p*,
  577. r3p*) erratum. A speculative memory access may cause a page table walk
  578. which starts prior to an ASID switch but completes afterwards. This
  579. can populate the micro-TLB with a stale entry which may be hit with
  580. the new ASID. This workaround places two dsb instructions in the mm
  581. switching code so that no page table walks can cross the ASID switch.
  582. config ARM_ERRATA_754327
  583. bool "ARM errata: no automatic Store Buffer drain"
  584. depends on CPU_V7 && SMP
  585. help
  586. This option enables the workaround for the 754327 Cortex-A9 (prior to
  587. r2p0) erratum. The Store Buffer does not have any automatic draining
  588. mechanism and therefore a livelock may occur if an external agent
  589. continuously polls a memory location waiting to observe an update.
  590. This workaround defines cpu_relax() as smp_mb(), preventing correctly
  591. written polling loops from denying visibility of updates to memory.
  592. config ARM_ERRATA_364296
  593. bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
  594. depends on CPU_V6
  595. help
  596. This options enables the workaround for the 364296 ARM1136
  597. r0p2 erratum (possible cache data corruption with
  598. hit-under-miss enabled). It sets the undocumented bit 31 in
  599. the auxiliary control register and the FI bit in the control
  600. register, thus disabling hit-under-miss without putting the
  601. processor into full low interrupt latency mode. ARM11MPCore
  602. is not affected.
  603. config ARM_ERRATA_764369
  604. bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
  605. depends on CPU_V7 && SMP
  606. help
  607. This option enables the workaround for erratum 764369
  608. affecting Cortex-A9 MPCore with two or more processors (all
  609. current revisions). Under certain timing circumstances, a data
  610. cache line maintenance operation by MVA targeting an Inner
  611. Shareable memory region may fail to proceed up to either the
  612. Point of Coherency or to the Point of Unification of the
  613. system. This workaround adds a DSB instruction before the
  614. relevant cache maintenance functions and sets a specific bit
  615. in the diagnostic control register of the SCU.
  616. config ARM_ERRATA_764319
  617. bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
  618. depends on CPU_V7
  619. help
  620. This option enables the workaround for the 764319 Cortex-A9 erratum.
  621. CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
  622. unexpected Undefined Instruction exception when the DBGSWENABLE
  623. external pin is set to 0, even when the CP14 accesses are performed
  624. from a privileged mode. This work around catches the exception in a
  625. way the kernel does not stop execution.
  626. config ARM_ERRATA_775420
  627. bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
  628. depends on CPU_V7
  629. help
  630. This option enables the workaround for the 775420 Cortex-A9 (r2p2,
  631. r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
  632. operation aborts with MMU exception, it might cause the processor
  633. to deadlock. This workaround puts DSB before executing ISB if
  634. an abort may occur on cache maintenance.
  635. config ARM_ERRATA_798181
  636. bool "ARM errata: TLBI/DSB failure on Cortex-A15"
  637. depends on CPU_V7 && SMP
  638. help
  639. On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
  640. adequately shooting down all use of the old entries. This
  641. option enables the Linux kernel workaround for this erratum
  642. which sends an IPI to the CPUs that are running the same ASID
  643. as the one being invalidated.
  644. config ARM_ERRATA_773022
  645. bool "ARM errata: incorrect instructions may be executed from loop buffer"
  646. depends on CPU_V7
  647. help
  648. This option enables the workaround for the 773022 Cortex-A15
  649. (up to r0p4) erratum. In certain rare sequences of code, the
  650. loop buffer may deliver incorrect instructions. This
  651. workaround disables the loop buffer to avoid the erratum.
  652. config ARM_ERRATA_818325_852422
  653. bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
  654. depends on CPU_V7
  655. help
  656. This option enables the workaround for:
  657. - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
  658. instruction might deadlock. Fixed in r0p1.
  659. - Cortex-A12 852422: Execution of a sequence of instructions might
  660. lead to either a data corruption or a CPU deadlock. Not fixed in
  661. any Cortex-A12 cores yet.
  662. This workaround for all both errata involves setting bit[12] of the
  663. Feature Register. This bit disables an optimisation applied to a
  664. sequence of 2 instructions that use opposing condition codes.
  665. config ARM_ERRATA_821420
  666. bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
  667. depends on CPU_V7
  668. help
  669. This option enables the workaround for the 821420 Cortex-A12
  670. (all revs) erratum. In very rare timing conditions, a sequence
  671. of VMOV to Core registers instructions, for which the second
  672. one is in the shadow of a branch or abort, can lead to a
  673. deadlock when the VMOV instructions are issued out-of-order.
  674. config ARM_ERRATA_825619
  675. bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
  676. depends on CPU_V7
  677. help
  678. This option enables the workaround for the 825619 Cortex-A12
  679. (all revs) erratum. Within rare timing constraints, executing a
  680. DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
  681. and Device/Strongly-Ordered loads and stores might cause deadlock
  682. config ARM_ERRATA_857271
  683. bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
  684. depends on CPU_V7
  685. help
  686. This option enables the workaround for the 857271 Cortex-A12
  687. (all revs) erratum. Under very rare timing conditions, the CPU might
  688. hang. The workaround is expected to have a < 1% performance impact.
  689. config ARM_ERRATA_852421
  690. bool "ARM errata: A17: DMB ST might fail to create order between stores"
  691. depends on CPU_V7
  692. help
  693. This option enables the workaround for the 852421 Cortex-A17
  694. (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
  695. execution of a DMB ST instruction might fail to properly order
  696. stores from GroupA and stores from GroupB.
  697. config ARM_ERRATA_852423
  698. bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
  699. depends on CPU_V7
  700. help
  701. This option enables the workaround for:
  702. - Cortex-A17 852423: Execution of a sequence of instructions might
  703. lead to either a data corruption or a CPU deadlock. Not fixed in
  704. any Cortex-A17 cores yet.
  705. This is identical to Cortex-A12 erratum 852422. It is a separate
  706. config option from the A12 erratum due to the way errata are checked
  707. for and handled.
  708. config ARM_ERRATA_857272
  709. bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
  710. depends on CPU_V7
  711. help
  712. This option enables the workaround for the 857272 Cortex-A17 erratum.
  713. This erratum is not known to be fixed in any A17 revision.
  714. This is identical to Cortex-A12 erratum 857271. It is a separate
  715. config option from the A12 erratum due to the way errata are checked
  716. for and handled.
  717. endmenu
  718. source "arch/arm/common/Kconfig"
  719. menu "Bus support"
  720. config ISA
  721. bool
  722. help
  723. Find out whether you have ISA slots on your motherboard. ISA is the
  724. name of a bus system, i.e. the way the CPU talks to the other stuff
  725. inside your box. Other bus systems are PCI, EISA, MicroChannel
  726. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  727. newer boards don't support it. If you have ISA, say Y, otherwise N.
  728. # Select ISA DMA interface
  729. config ISA_DMA_API
  730. bool
  731. config ARM_ERRATA_814220
  732. bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
  733. depends on CPU_V7
  734. help
  735. The v7 ARM states that all cache and branch predictor maintenance
  736. operations that do not specify an address execute, relative to
  737. each other, in program order.
  738. However, because of this erratum, an L2 set/way cache maintenance
  739. operation can overtake an L1 set/way cache maintenance operation.
  740. This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
  741. r0p4, r0p5.
  742. endmenu
  743. menu "Kernel Features"
  744. config HAVE_SMP
  745. bool
  746. help
  747. This option should be selected by machines which have an SMP-
  748. capable CPU.
  749. The only effect of this option is to make the SMP-related
  750. options available to the user for configuration.
  751. config SMP
  752. bool "Symmetric Multi-Processing"
  753. depends on CPU_V6K || CPU_V7
  754. depends on HAVE_SMP
  755. depends on MMU || ARM_MPU
  756. select IRQ_WORK
  757. help
  758. This enables support for systems with more than one CPU. If you have
  759. a system with only one CPU, say N. If you have a system with more
  760. than one CPU, say Y.
  761. If you say N here, the kernel will run on uni- and multiprocessor
  762. machines, but will use only one CPU of a multiprocessor machine. If
  763. you say Y here, the kernel will run on many, but not all,
  764. uniprocessor machines. On a uniprocessor machine, the kernel
  765. will run faster if you say N here.
  766. See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
  767. <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
  768. <http://tldp.org/HOWTO/SMP-HOWTO.html>.
  769. If you don't know what to do here, say N.
  770. config SMP_ON_UP
  771. bool "Allow booting SMP kernel on uniprocessor systems"
  772. depends on SMP && MMU
  773. default y
  774. help
  775. SMP kernels contain instructions which fail on non-SMP processors.
  776. Enabling this option allows the kernel to modify itself to make
  777. these instructions safe. Disabling it allows about 1K of space
  778. savings.
  779. If you don't know what to do here, say Y.
  780. config CURRENT_POINTER_IN_TPIDRURO
  781. def_bool y
  782. depends on CPU_32v6K && !CPU_V6
  783. config IRQSTACKS
  784. def_bool y
  785. select HAVE_IRQ_EXIT_ON_IRQ_STACK
  786. select HAVE_SOFTIRQ_ON_OWN_STACK
  787. config ARM_CPU_TOPOLOGY
  788. bool "Support cpu topology definition"
  789. depends on SMP && CPU_V7
  790. default y
  791. help
  792. Support ARM cpu topology definition. The MPIDR register defines
  793. affinity between processors which is then used to describe the cpu
  794. topology of an ARM System.
  795. config SCHED_MC
  796. bool "Multi-core scheduler support"
  797. depends on ARM_CPU_TOPOLOGY
  798. help
  799. Multi-core scheduler support improves the CPU scheduler's decision
  800. making when dealing with multi-core CPU chips at a cost of slightly
  801. increased overhead in some places. If unsure say N here.
  802. config SCHED_SMT
  803. bool "SMT scheduler support"
  804. depends on ARM_CPU_TOPOLOGY
  805. help
  806. Improves the CPU scheduler's decision making when dealing with
  807. MultiThreading at a cost of slightly increased overhead in some
  808. places. If unsure say N here.
  809. config HAVE_ARM_SCU
  810. bool
  811. help
  812. This option enables support for the ARM snoop control unit
  813. config HAVE_ARM_ARCH_TIMER
  814. bool "Architected timer support"
  815. depends on CPU_V7
  816. select ARM_ARCH_TIMER
  817. help
  818. This option enables support for the ARM architected timer
  819. config HAVE_ARM_TWD
  820. bool
  821. help
  822. This options enables support for the ARM timer and watchdog unit
  823. config MCPM
  824. bool "Multi-Cluster Power Management"
  825. depends on CPU_V7 && SMP
  826. help
  827. This option provides the common power management infrastructure
  828. for (multi-)cluster based systems, such as big.LITTLE based
  829. systems.
  830. config MCPM_QUAD_CLUSTER
  831. bool
  832. depends on MCPM
  833. help
  834. To avoid wasting resources unnecessarily, MCPM only supports up
  835. to 2 clusters by default.
  836. Platforms with 3 or 4 clusters that use MCPM must select this
  837. option to allow the additional clusters to be managed.
  838. config BIG_LITTLE
  839. bool "big.LITTLE support (Experimental)"
  840. depends on CPU_V7 && SMP
  841. select MCPM
  842. help
  843. This option enables support selections for the big.LITTLE
  844. system architecture.
  845. config BL_SWITCHER
  846. bool "big.LITTLE switcher support"
  847. depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
  848. select CPU_PM
  849. help
  850. The big.LITTLE "switcher" provides the core functionality to
  851. transparently handle transition between a cluster of A15's
  852. and a cluster of A7's in a big.LITTLE system.
  853. config BL_SWITCHER_DUMMY_IF
  854. tristate "Simple big.LITTLE switcher user interface"
  855. depends on BL_SWITCHER && DEBUG_KERNEL
  856. help
  857. This is a simple and dummy char dev interface to control
  858. the big.LITTLE switcher core code. It is meant for
  859. debugging purposes only.
  860. choice
  861. prompt "Memory split"
  862. depends on MMU
  863. default VMSPLIT_3G
  864. help
  865. Select the desired split between kernel and user memory.
  866. If you are not absolutely sure what you are doing, leave this
  867. option alone!
  868. config VMSPLIT_3G
  869. bool "3G/1G user/kernel split"
  870. config VMSPLIT_3G_OPT
  871. depends on !ARM_LPAE
  872. bool "3G/1G user/kernel split (for full 1G low memory)"
  873. config VMSPLIT_2G
  874. bool "2G/2G user/kernel split"
  875. config VMSPLIT_1G
  876. bool "1G/3G user/kernel split"
  877. endchoice
  878. config PAGE_OFFSET
  879. hex
  880. default PHYS_OFFSET if !MMU
  881. default 0x40000000 if VMSPLIT_1G
  882. default 0x80000000 if VMSPLIT_2G
  883. default 0xB0000000 if VMSPLIT_3G_OPT
  884. default 0xC0000000
  885. config KASAN_SHADOW_OFFSET
  886. hex
  887. depends on KASAN
  888. default 0x1f000000 if PAGE_OFFSET=0x40000000
  889. default 0x5f000000 if PAGE_OFFSET=0x80000000
  890. default 0x9f000000 if PAGE_OFFSET=0xC0000000
  891. default 0x8f000000 if PAGE_OFFSET=0xB0000000
  892. default 0xffffffff
  893. config NR_CPUS
  894. int "Maximum number of CPUs (2-32)"
  895. range 2 16 if DEBUG_KMAP_LOCAL
  896. range 2 32 if !DEBUG_KMAP_LOCAL
  897. depends on SMP
  898. default "4"
  899. help
  900. The maximum number of CPUs that the kernel can support.
  901. Up to 32 CPUs can be supported, or up to 16 if kmap_local()
  902. debugging is enabled, which uses half of the per-CPU fixmap
  903. slots as guard regions.
  904. config HOTPLUG_CPU
  905. bool "Support for hot-pluggable CPUs"
  906. depends on SMP
  907. select GENERIC_IRQ_MIGRATION
  908. help
  909. Say Y here to experiment with turning CPUs off and on. CPUs
  910. can be controlled through /sys/devices/system/cpu.
  911. config ARM_PSCI
  912. bool "Support for the ARM Power State Coordination Interface (PSCI)"
  913. depends on HAVE_ARM_SMCCC
  914. select ARM_PSCI_FW
  915. help
  916. Say Y here if you want Linux to communicate with system firmware
  917. implementing the PSCI specification for CPU-centric power
  918. management operations described in ARM document number ARM DEN
  919. 0022A ("Power State Coordination Interface System Software on
  920. ARM processors").
  921. config HZ_FIXED
  922. int
  923. default 128 if SOC_AT91RM9200
  924. default 0
  925. choice
  926. depends on HZ_FIXED = 0
  927. prompt "Timer frequency"
  928. config HZ_100
  929. bool "100 Hz"
  930. config HZ_200
  931. bool "200 Hz"
  932. config HZ_250
  933. bool "250 Hz"
  934. config HZ_300
  935. bool "300 Hz"
  936. config HZ_500
  937. bool "500 Hz"
  938. config HZ_1000
  939. bool "1000 Hz"
  940. endchoice
  941. config HZ
  942. int
  943. default HZ_FIXED if HZ_FIXED != 0
  944. default 100 if HZ_100
  945. default 200 if HZ_200
  946. default 250 if HZ_250
  947. default 300 if HZ_300
  948. default 500 if HZ_500
  949. default 1000
  950. config SCHED_HRTICK
  951. def_bool HIGH_RES_TIMERS
  952. config THUMB2_KERNEL
  953. bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
  954. depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
  955. default y if CPU_THUMBONLY
  956. select ARM_UNWIND
  957. help
  958. By enabling this option, the kernel will be compiled in
  959. Thumb-2 mode.
  960. If unsure, say N.
  961. config ARM_PATCH_IDIV
  962. bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
  963. depends on CPU_32v7
  964. default y
  965. help
  966. The ARM compiler inserts calls to __aeabi_idiv() and
  967. __aeabi_uidiv() when it needs to perform division on signed
  968. and unsigned integers. Some v7 CPUs have support for the sdiv
  969. and udiv instructions that can be used to implement those
  970. functions.
  971. Enabling this option allows the kernel to modify itself to
  972. replace the first two instructions of these library functions
  973. with the sdiv or udiv plus "bx lr" instructions when the CPU
  974. it is running on supports them. Typically this will be faster
  975. and less power intensive than running the original library
  976. code to do integer division.
  977. config AEABI
  978. bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
  979. !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
  980. default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
  981. help
  982. This option allows for the kernel to be compiled using the latest
  983. ARM ABI (aka EABI). This is only useful if you are using a user
  984. space environment that is also compiled with EABI.
  985. Since there are major incompatibilities between the legacy ABI and
  986. EABI, especially with regard to structure member alignment, this
  987. option also changes the kernel syscall calling convention to
  988. disambiguate both ABIs and allow for backward compatibility support
  989. (selected with CONFIG_OABI_COMPAT).
  990. To use this you need GCC version 4.0.0 or later.
  991. config OABI_COMPAT
  992. bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
  993. depends on AEABI && !THUMB2_KERNEL
  994. help
  995. This option preserves the old syscall interface along with the
  996. new (ARM EABI) one. It also provides a compatibility layer to
  997. intercept syscalls that have structure arguments which layout
  998. in memory differs between the legacy ABI and the new ARM EABI
  999. (only for non "thumb" binaries). This option adds a tiny
  1000. overhead to all syscalls and produces a slightly larger kernel.
  1001. The seccomp filter system will not be available when this is
  1002. selected, since there is no way yet to sensibly distinguish
  1003. between calling conventions during filtering.
  1004. If you know you'll be using only pure EABI user space then you
  1005. can say N here. If this option is not selected and you attempt
  1006. to execute a legacy ABI binary then the result will be
  1007. UNPREDICTABLE (in fact it can be predicted that it won't work
  1008. at all). If in doubt say N.
  1009. config ARCH_SELECT_MEMORY_MODEL
  1010. def_bool y
  1011. config ARCH_FLATMEM_ENABLE
  1012. def_bool !(ARCH_RPC || ARCH_SA1100)
  1013. config ARCH_SPARSEMEM_ENABLE
  1014. def_bool !ARCH_FOOTBRIDGE
  1015. select SPARSEMEM_STATIC if SPARSEMEM
  1016. config HIGHMEM
  1017. bool "High Memory Support"
  1018. depends on MMU
  1019. select KMAP_LOCAL
  1020. select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
  1021. help
  1022. The address space of ARM processors is only 4 Gigabytes large
  1023. and it has to accommodate user address space, kernel address
  1024. space as well as some memory mapped IO. That means that, if you
  1025. have a large amount of physical memory and/or IO, not all of the
  1026. memory can be "permanently mapped" by the kernel. The physical
  1027. memory that is not permanently mapped is called "high memory".
  1028. Depending on the selected kernel/user memory split, minimum
  1029. vmalloc space and actual amount of RAM, you may not need this
  1030. option which should result in a slightly faster kernel.
  1031. If unsure, say n.
  1032. config HIGHPTE
  1033. bool "Allocate 2nd-level pagetables from highmem" if EXPERT
  1034. depends on HIGHMEM
  1035. default y
  1036. help
  1037. The VM uses one page of physical memory for each page table.
  1038. For systems with a lot of processes, this can use a lot of
  1039. precious low memory, eventually leading to low memory being
  1040. consumed by page tables. Setting this option will allow
  1041. user-space 2nd level page tables to reside in high memory.
  1042. config ARM_PAN
  1043. bool "Enable privileged no-access"
  1044. depends on MMU
  1045. default y
  1046. help
  1047. Increase kernel security by ensuring that normal kernel accesses
  1048. are unable to access userspace addresses. This can help prevent
  1049. use-after-free bugs becoming an exploitable privilege escalation
  1050. by ensuring that magic values (such as LIST_POISON) will always
  1051. fault when dereferenced.
  1052. The implementation uses CPU domains when !CONFIG_ARM_LPAE and
  1053. disabling of TTBR0 page table walks with CONFIG_ARM_LPAE.
  1054. config CPU_SW_DOMAIN_PAN
  1055. def_bool y
  1056. depends on ARM_PAN && !ARM_LPAE
  1057. help
  1058. Enable use of CPU domains to implement privileged no-access.
  1059. CPUs with low-vector mappings use a best-efforts implementation.
  1060. Their lower 1MB needs to remain accessible for the vectors, but
  1061. the remainder of userspace will become appropriately inaccessible.
  1062. config CPU_TTBR0_PAN
  1063. def_bool y
  1064. depends on ARM_PAN && ARM_LPAE
  1065. help
  1066. Enable privileged no-access by disabling TTBR0 page table walks when
  1067. running in kernel mode.
  1068. config HW_PERF_EVENTS
  1069. def_bool y
  1070. depends on ARM_PMU
  1071. config ARM_MODULE_PLTS
  1072. bool "Use PLTs to allow module memory to spill over into vmalloc area"
  1073. depends on MODULES
  1074. select KASAN_VMALLOC if KASAN
  1075. default y
  1076. help
  1077. Allocate PLTs when loading modules so that jumps and calls whose
  1078. targets are too far away for their relative offsets to be encoded
  1079. in the instructions themselves can be bounced via veneers in the
  1080. module's PLT. This allows modules to be allocated in the generic
  1081. vmalloc area after the dedicated module memory area has been
  1082. exhausted. The modules will use slightly more memory, but after
  1083. rounding up to page size, the actual memory footprint is usually
  1084. the same.
  1085. Disabling this is usually safe for small single-platform
  1086. configurations. If unsure, say y.
  1087. config ARCH_FORCE_MAX_ORDER
  1088. int "Order of maximal physically contiguous allocations"
  1089. default "11" if SOC_AM33XX
  1090. default "8" if SA1111
  1091. default "10"
  1092. help
  1093. The kernel page allocator limits the size of maximal physically
  1094. contiguous allocations. The limit is called MAX_PAGE_ORDER and it
  1095. defines the maximal power of two of number of pages that can be
  1096. allocated as a single contiguous block. This option allows
  1097. overriding the default setting when ability to allocate very
  1098. large blocks of physically contiguous memory is required.
  1099. Don't change if unsure.
  1100. config ALIGNMENT_TRAP
  1101. def_bool CPU_CP15_MMU
  1102. select HAVE_PROC_CPU if PROC_FS
  1103. help
  1104. ARM processors cannot fetch/store information which is not
  1105. naturally aligned on the bus, i.e., a 4 byte fetch must start at an
  1106. address divisible by 4. On 32-bit ARM processors, these non-aligned
  1107. fetch/store instructions will be emulated in software if you say
  1108. here, which has a severe performance impact. This is necessary for
  1109. correct operation of some network protocols. With an IP-only
  1110. configuration it is safe to say N, otherwise say Y.
  1111. config UACCESS_WITH_MEMCPY
  1112. bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
  1113. depends on MMU
  1114. default y if CPU_FEROCEON
  1115. help
  1116. Implement faster copy_to_user and clear_user methods for CPU
  1117. cores where a 8-word STM instruction give significantly higher
  1118. memory write throughput than a sequence of individual 32bit stores.
  1119. A possible side effect is a slight increase in scheduling latency
  1120. between threads sharing the same address space if they invoke
  1121. such copy operations with large buffers.
  1122. However, if the CPU data cache is using a write-allocate mode,
  1123. this option is unlikely to provide any performance gain.
  1124. config PARAVIRT
  1125. bool "Enable paravirtualization code"
  1126. help
  1127. This changes the kernel so it can modify itself when it is run
  1128. under a hypervisor, potentially improving performance significantly
  1129. over full virtualization.
  1130. config PARAVIRT_TIME_ACCOUNTING
  1131. bool "Paravirtual steal time accounting"
  1132. select PARAVIRT
  1133. help
  1134. Select this option to enable fine granularity task steal time
  1135. accounting. Time spent executing other tasks in parallel with
  1136. the current vCPU is discounted from the vCPU power. To account for
  1137. that, there can be a small performance impact.
  1138. If in doubt, say N here.
  1139. config XEN_DOM0
  1140. def_bool y
  1141. depends on XEN
  1142. config XEN
  1143. bool "Xen guest support on ARM"
  1144. depends on ARM && AEABI && OF
  1145. depends on CPU_V7 && !CPU_V6
  1146. depends on !GENERIC_ATOMIC64
  1147. depends on MMU
  1148. select ARCH_DMA_ADDR_T_64BIT
  1149. select ARM_PSCI
  1150. select SWIOTLB
  1151. select SWIOTLB_XEN
  1152. select PARAVIRT
  1153. help
  1154. Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
  1155. config CC_HAVE_STACKPROTECTOR_TLS
  1156. def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
  1157. config STACKPROTECTOR_PER_TASK
  1158. bool "Use a unique stack canary value for each task"
  1159. depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
  1160. depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
  1161. select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
  1162. default y
  1163. help
  1164. Due to the fact that GCC uses an ordinary symbol reference from
  1165. which to load the value of the stack canary, this value can only
  1166. change at reboot time on SMP systems, and all tasks running in the
  1167. kernel's address space are forced to use the same canary value for
  1168. the entire duration that the system is up.
  1169. Enable this option to switch to a different method that uses a
  1170. different canary value for each task.
  1171. endmenu
  1172. menu "Boot options"
  1173. config USE_OF
  1174. bool "Flattened Device Tree support"
  1175. select IRQ_DOMAIN
  1176. select OF
  1177. help
  1178. Include support for flattened device tree machine descriptions.
  1179. config ARCH_WANT_FLAT_DTB_INSTALL
  1180. def_bool y
  1181. config ATAGS
  1182. bool "Support for the traditional ATAGS boot data passing"
  1183. default y
  1184. help
  1185. This is the traditional way of passing data to the kernel at boot
  1186. time. If you are solely relying on the flattened device tree (or
  1187. the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
  1188. to remove ATAGS support from your kernel binary.
  1189. config DEPRECATED_PARAM_STRUCT
  1190. bool "Provide old way to pass kernel parameters"
  1191. depends on ATAGS
  1192. help
  1193. This was deprecated in 2001 and announced to live on for 5 years.
  1194. Some old boot loaders still use this way.
  1195. # Compressed boot loader in ROM. Yes, we really want to ask about
  1196. # TEXT and BSS so we preserve their values in the config files.
  1197. config ZBOOT_ROM_TEXT
  1198. hex "Compressed ROM boot loader base address"
  1199. default 0x0
  1200. help
  1201. The physical address at which the ROM-able zImage is to be
  1202. placed in the target. Platforms which normally make use of
  1203. ROM-able zImage formats normally set this to a suitable
  1204. value in their defconfig file.
  1205. If ZBOOT_ROM is not enabled, this has no effect.
  1206. config ZBOOT_ROM_BSS
  1207. hex "Compressed ROM boot loader BSS address"
  1208. default 0x0
  1209. help
  1210. The base address of an area of read/write memory in the target
  1211. for the ROM-able zImage which must be available while the
  1212. decompressor is running. It must be large enough to hold the
  1213. entire decompressed kernel plus an additional 128 KiB.
  1214. Platforms which normally make use of ROM-able zImage formats
  1215. normally set this to a suitable value in their defconfig file.
  1216. If ZBOOT_ROM is not enabled, this has no effect.
  1217. config ZBOOT_ROM
  1218. bool "Compressed boot loader in ROM/flash"
  1219. depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
  1220. depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
  1221. help
  1222. Say Y here if you intend to execute your compressed kernel image
  1223. (zImage) directly from ROM or flash. If unsure, say N.
  1224. config ARM_APPENDED_DTB
  1225. bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
  1226. depends on OF
  1227. help
  1228. With this option, the boot code will look for a device tree binary
  1229. (DTB) appended to zImage
  1230. (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
  1231. This is meant as a backward compatibility convenience for those
  1232. systems with a bootloader that can't be upgraded to accommodate
  1233. the documented boot protocol using a device tree.
  1234. Beware that there is very little in terms of protection against
  1235. this option being confused by leftover garbage in memory that might
  1236. look like a DTB header after a reboot if no actual DTB is appended
  1237. to zImage. Do not leave this option active in a production kernel
  1238. if you don't intend to always append a DTB. Proper passing of the
  1239. location into r2 of a bootloader provided DTB is always preferable
  1240. to this option.
  1241. config ARM_ATAG_DTB_COMPAT
  1242. bool "Supplement the appended DTB with traditional ATAG information"
  1243. depends on ARM_APPENDED_DTB
  1244. help
  1245. Some old bootloaders can't be updated to a DTB capable one, yet
  1246. they provide ATAGs with memory configuration, the ramdisk address,
  1247. the kernel cmdline string, etc. Such information is dynamically
  1248. provided by the bootloader and can't always be stored in a static
  1249. DTB. To allow a device tree enabled kernel to be used with such
  1250. bootloaders, this option allows zImage to extract the information
  1251. from the ATAG list and store it at run time into the appended DTB.
  1252. choice
  1253. prompt "Kernel command line type"
  1254. depends on ARM_ATAG_DTB_COMPAT
  1255. default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
  1256. config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
  1257. bool "Use bootloader kernel arguments if available"
  1258. help
  1259. Uses the command-line options passed by the boot loader instead of
  1260. the device tree bootargs property. If the boot loader doesn't provide
  1261. any, the device tree bootargs property will be used.
  1262. config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
  1263. bool "Extend with bootloader kernel arguments"
  1264. help
  1265. The command-line arguments provided by the boot loader will be
  1266. appended to the the device tree bootargs property.
  1267. endchoice
  1268. config CMDLINE
  1269. string "Default kernel command string"
  1270. default ""
  1271. help
  1272. On some architectures (e.g. CATS), there is currently no way
  1273. for the boot loader to pass arguments to the kernel. For these
  1274. architectures, you should supply some command-line options at build
  1275. time by entering them here. As a minimum, you should specify the
  1276. memory size and the root device (e.g., mem=64M root=/dev/nfs).
  1277. choice
  1278. prompt "Kernel command line type"
  1279. depends on CMDLINE != ""
  1280. default CMDLINE_FROM_BOOTLOADER
  1281. config CMDLINE_FROM_BOOTLOADER
  1282. bool "Use bootloader kernel arguments if available"
  1283. help
  1284. Uses the command-line options passed by the boot loader. If
  1285. the boot loader doesn't provide any, the default kernel command
  1286. string provided in CMDLINE will be used.
  1287. config CMDLINE_EXTEND
  1288. bool "Extend bootloader kernel arguments"
  1289. help
  1290. The command-line arguments provided by the boot loader will be
  1291. appended to the default kernel command string.
  1292. config CMDLINE_FORCE
  1293. bool "Always use the default kernel command string"
  1294. help
  1295. Always use the default kernel command string, even if the boot
  1296. loader passes other arguments to the kernel.
  1297. This is useful if you cannot or don't want to change the
  1298. command-line options your boot loader passes to the kernel.
  1299. endchoice
  1300. config XIP_KERNEL
  1301. bool "Kernel Execute-In-Place from ROM"
  1302. depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
  1303. depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
  1304. help
  1305. Execute-In-Place allows the kernel to run from non-volatile storage
  1306. directly addressable by the CPU, such as NOR flash. This saves RAM
  1307. space since the text section of the kernel is not loaded from flash
  1308. to RAM. Read-write sections, such as the data section and stack,
  1309. are still copied to RAM. The XIP kernel is not compressed since
  1310. it has to run directly from flash, so it will take more space to
  1311. store it. The flash address used to link the kernel object files,
  1312. and for storing it, is configuration dependent. Therefore, if you
  1313. say Y here, you must know the proper physical address where to
  1314. store the kernel image depending on your own flash memory usage.
  1315. Also note that the make target becomes "make xipImage" rather than
  1316. "make zImage" or "make Image". The final kernel binary to put in
  1317. ROM memory will be arch/arm/boot/xipImage.
  1318. If unsure, say N.
  1319. config XIP_PHYS_ADDR
  1320. hex "XIP Kernel Physical Location"
  1321. depends on XIP_KERNEL
  1322. default "0x00080000"
  1323. help
  1324. This is the physical address in your flash memory the kernel will
  1325. be linked for and stored to. This address is dependent on your
  1326. own flash usage.
  1327. config XIP_DEFLATED_DATA
  1328. bool "Store kernel .data section compressed in ROM"
  1329. depends on XIP_KERNEL
  1330. select ZLIB_INFLATE
  1331. help
  1332. Before the kernel is actually executed, its .data section has to be
  1333. copied to RAM from ROM. This option allows for storing that data
  1334. in compressed form and decompressed to RAM rather than merely being
  1335. copied, saving some precious ROM space. A possible drawback is a
  1336. slightly longer boot delay.
  1337. config ARCH_SUPPORTS_KEXEC
  1338. def_bool (!SMP || PM_SLEEP_SMP) && MMU
  1339. config ATAGS_PROC
  1340. bool "Export atags in procfs"
  1341. depends on ATAGS && KEXEC
  1342. default y
  1343. help
  1344. Should the atags used to boot the kernel be exported in an "atags"
  1345. file in procfs. Useful with kexec.
  1346. config ARCH_SUPPORTS_CRASH_DUMP
  1347. def_bool y
  1348. config ARCH_DEFAULT_CRASH_DUMP
  1349. def_bool y
  1350. config AUTO_ZRELADDR
  1351. bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
  1352. default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
  1353. help
  1354. ZRELADDR is the physical address where the decompressed kernel
  1355. image will be placed. If AUTO_ZRELADDR is selected, the address
  1356. will be determined at run-time, either by masking the current IP
  1357. with 0xf8000000, or, if invalid, from the DTB passed in r2.
  1358. This assumes the zImage being placed in the first 128MB from
  1359. start of memory.
  1360. config EFI_STUB
  1361. bool
  1362. config EFI
  1363. bool "UEFI runtime support"
  1364. depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
  1365. select UCS2_STRING
  1366. select EFI_PARAMS_FROM_FDT
  1367. select EFI_STUB
  1368. select EFI_GENERIC_STUB
  1369. select EFI_RUNTIME_WRAPPERS
  1370. help
  1371. This option provides support for runtime services provided
  1372. by UEFI firmware (such as non-volatile variables, realtime
  1373. clock, and platform reset). A UEFI stub is also provided to
  1374. allow the kernel to be booted as an EFI application. This
  1375. is only useful for kernels that may run on systems that have
  1376. UEFI firmware.
  1377. config DMI
  1378. bool "Enable support for SMBIOS (DMI) tables"
  1379. depends on EFI
  1380. default y
  1381. help
  1382. This enables SMBIOS/DMI feature for systems.
  1383. This option is only useful on systems that have UEFI firmware.
  1384. However, even with this option, the resultant kernel should
  1385. continue to boot on existing non-UEFI platforms.
  1386. NOTE: This does *NOT* enable or encourage the use of DMI quirks,
  1387. i.e., the the practice of identifying the platform via DMI to
  1388. decide whether certain workarounds for buggy hardware and/or
  1389. firmware need to be enabled. This would require the DMI subsystem
  1390. to be enabled much earlier than we do on ARM, which is non-trivial.
  1391. endmenu
  1392. menu "CPU Power Management"
  1393. source "drivers/cpufreq/Kconfig"
  1394. source "drivers/cpuidle/Kconfig"
  1395. endmenu
  1396. menu "Floating point emulation"
  1397. comment "At least one emulation must be selected"
  1398. config FPE_NWFPE
  1399. bool "NWFPE math emulation"
  1400. depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
  1401. help
  1402. Say Y to include the NWFPE floating point emulator in the kernel.
  1403. This is necessary to run most binaries. Linux does not currently
  1404. support floating point hardware so you need to say Y here even if
  1405. your machine has an FPA or floating point co-processor podule.
  1406. You may say N here if you are going to load the Acorn FPEmulator
  1407. early in the bootup.
  1408. config FPE_NWFPE_XP
  1409. bool "Support extended precision"
  1410. depends on FPE_NWFPE
  1411. help
  1412. Say Y to include 80-bit support in the kernel floating-point
  1413. emulator. Otherwise, only 32 and 64-bit support is compiled in.
  1414. Note that gcc does not generate 80-bit operations by default,
  1415. so in most cases this option only enlarges the size of the
  1416. floating point emulator without any good reason.
  1417. You almost surely want to say N here.
  1418. config FPE_FASTFPE
  1419. bool "FastFPE math emulation (EXPERIMENTAL)"
  1420. depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
  1421. help
  1422. Say Y here to include the FAST floating point emulator in the kernel.
  1423. This is an experimental much faster emulator which now also has full
  1424. precision for the mantissa. It does not support any exceptions.
  1425. It is very simple, and approximately 3-6 times faster than NWFPE.
  1426. It should be sufficient for most programs. It may be not suitable
  1427. for scientific calculations, but you have to check this for yourself.
  1428. If you do not feel you need a faster FP emulation you should better
  1429. choose NWFPE.
  1430. config VFP
  1431. bool "VFP-format floating point maths"
  1432. depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
  1433. help
  1434. Say Y to include VFP support code in the kernel. This is needed
  1435. if your hardware includes a VFP unit.
  1436. Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
  1437. release notes and additional status information.
  1438. Say N if your target does not have VFP hardware.
  1439. config VFPv3
  1440. bool
  1441. depends on VFP
  1442. default y if CPU_V7
  1443. config NEON
  1444. bool "Advanced SIMD (NEON) Extension support"
  1445. depends on VFPv3 && CPU_V7
  1446. help
  1447. Say Y to include support code for NEON, the ARMv7 Advanced SIMD
  1448. Extension.
  1449. config KERNEL_MODE_NEON
  1450. bool "Support for NEON in kernel mode"
  1451. depends on NEON && AEABI
  1452. help
  1453. Say Y to include support for NEON in kernel mode.
  1454. endmenu
  1455. menu "Power management options"
  1456. source "kernel/power/Kconfig"
  1457. config ARCH_SUSPEND_POSSIBLE
  1458. depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
  1459. CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
  1460. def_bool y
  1461. config ARM_CPU_SUSPEND
  1462. def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
  1463. depends on ARCH_SUSPEND_POSSIBLE
  1464. config ARCH_HIBERNATION_POSSIBLE
  1465. bool
  1466. depends on MMU
  1467. default y if ARCH_SUSPEND_POSSIBLE
  1468. endmenu
  1469. source "arch/arm/Kconfig.assembler"