1# SPDX-License-Identifier: GPL-2.0
   2config 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)
 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
 166config ARM_HAS_GROUP_RELOCS
 167	def_bool y
 168	depends on !LD_IS_LLD || LLD_VERSION >= 140000
 169	depends on !COMPILE_TEST
 170	help
 171	  Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group
 172	  relocations, which have been around for a long time, but were not
 173	  supported in LLD until version 14. The combined range is -/+ 256 MiB,
 174	  which is usually sufficient, but not for allyesconfig, so we disable
 175	  this feature when doing compile testing.
 176
 177config ARM_DMA_USE_IOMMU
 178	bool
 
 179	select NEED_SG_DMA_LENGTH
 180
 181if ARM_DMA_USE_IOMMU
 182
 183config ARM_DMA_IOMMU_ALIGNMENT
 184	int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
 185	range 4 9
 186	default 8
 187	help
 188	  DMA mapping framework by default aligns all buffers to the smallest
 189	  PAGE_SIZE order which is greater than or equal to the requested buffer
 190	  size. This works well for buffers up to a few hundreds kilobytes, but
 191	  for larger buffers it just a waste of address space. Drivers which has
 192	  relatively small addressing window (like 64Mib) might run out of
 193	  virtual space with just a few allocations.
 194
 195	  With this parameter you can specify the maximum PAGE_SIZE order for
 196	  DMA IOMMU buffers. Larger buffers will be aligned only to this
 197	  specified order. The order is expressed as a power of two multiplied
 198	  by the PAGE_SIZE.
 199
 200endif
 201
 202config SYS_SUPPORTS_APM_EMULATION
 203	bool
 204
 205config HAVE_TCM
 206	bool
 207	select GENERIC_ALLOCATOR
 208
 209config HAVE_PROC_CPU
 210	bool
 211
 212config NO_IOPORT_MAP
 213	bool
 214
 215config SBUS
 216	bool
 217
 218config STACKTRACE_SUPPORT
 219	bool
 220	default y
 221
 222config LOCKDEP_SUPPORT
 223	bool
 224	default y
 225
 
 
 
 
 226config ARCH_HAS_ILOG2_U32
 227	bool
 228
 229config ARCH_HAS_ILOG2_U64
 230	bool
 231
 232config ARCH_HAS_BANDGAP
 233	bool
 234
 235config FIX_EARLYCON_MEM
 236	def_bool y if MMU
 237
 238config GENERIC_HWEIGHT
 239	bool
 240	default y
 241
 242config GENERIC_CALIBRATE_DELAY
 243	bool
 244	default y
 245
 246config ARCH_MAY_HAVE_PC_FDC
 247	bool
 248
 249config ARCH_SUPPORTS_UPROBES
 250	def_bool y
 251
 
 
 
 252config GENERIC_ISA_DMA
 253	bool
 254
 255config FIQ
 256	bool
 257
 
 
 
 258config ARCH_MTD_XIP
 259	bool
 260
 261config ARM_PATCH_PHYS_VIRT
 262	bool "Patch physical to virtual translations at runtime" if !ARCH_MULTIPLATFORM
 263	default y
 264	depends on MMU
 265	help
 266	  Patch phys-to-virt and virt-to-phys translation functions at
 267	  boot and module load time according to the position of the
 268	  kernel in system memory.
 269
 270	  This can only be used with non-XIP MMU kernels where the base
 271	  of physical memory is at a 2 MiB boundary.
 272
 273	  Only disable this option if you know that you do not require
 274	  this feature (eg, building a kernel for a single machine) and
 275	  you need to shrink the kernel to the minimal size.
 276
 277config NEED_MACH_IO_H
 278	bool
 279	help
 280	  Select this when mach/io.h is required to provide special
 281	  definitions for this platform.  The need for mach/io.h should
 282	  be avoided when possible.
 283
 284config NEED_MACH_MEMORY_H
 285	bool
 286	help
 287	  Select this when mach/memory.h is required to provide special
 288	  definitions for this platform.  The need for mach/memory.h should
 289	  be avoided when possible.
 290
 291config PHYS_OFFSET
 292	hex "Physical address of main memory" if MMU
 293	depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR
 294	default DRAM_BASE if !MMU
 295	default 0x00000000 if ARCH_FOOTBRIDGE
 296	default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
 297	default 0xa0000000 if ARCH_PXA
 298	default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100
 299	default 0
 300	help
 301	  Please provide the physical address corresponding to the
 302	  location of main memory in your system.
 303
 304config GENERIC_BUG
 305	def_bool y
 306	depends on BUG
 307
 308config PGTABLE_LEVELS
 309	int
 310	default 3 if ARM_LPAE
 311	default 2
 312
 313menu "System Type"
 314
 315config MMU
 316	bool "MMU-based Paged Memory Management Support"
 317	default y
 318	help
 319	  Select if you want MMU-based virtualised addressing space
 320	  support by paged memory management. If unsure, say 'Y'.
 321
 322config ARM_SINGLE_ARMV7M
 323	def_bool !MMU
 324	select ARM_NVIC
 325	select CPU_V7M
 326	select NO_IOPORT_MAP
 327
 328config ARCH_MMAP_RND_BITS_MIN
 329	default 8
 330
 331config ARCH_MMAP_RND_BITS_MAX
 332	default 14 if PAGE_OFFSET=0x40000000
 333	default 15 if PAGE_OFFSET=0x80000000
 334	default 16
 335
 
 
 
 
 
 
 
 
 
 336config ARCH_MULTIPLATFORM
 337	bool "Require kernel to be portable to multiple machines" if EXPERT
 338	depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
 339	default y
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 340	help
 341	  In general, all Arm machines can be supported in a single
 342	  kernel image, covering either Armv4/v5 or Armv6/v7.
 343
 344	  However, some configuration options require hardcoding machine
 345	  specific physical addresses or enable errata workarounds that may
 346	  break other machines.
 
 
 
 
 
 
 
 
 
 347
 348	  Selecting N here allows using those options, including
 349	  DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 350
 351source "arch/arm/Kconfig.platforms"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 352
 353#
 354# This is sorted alphabetically by mach-* pathname.  However, plat-*
 355# Kconfigs may be included either alphabetically (according to the
 356# plat- suffix) or along side the corresponding mach-* source.
 357#
 358source "arch/arm/mach-actions/Kconfig"
 359
 360source "arch/arm/mach-alpine/Kconfig"
 361
 362source "arch/arm/mach-artpec/Kconfig"
 363
 
 
 364source "arch/arm/mach-aspeed/Kconfig"
 365
 366source "arch/arm/mach-at91/Kconfig"
 367
 368source "arch/arm/mach-axxia/Kconfig"
 369
 370source "arch/arm/mach-bcm/Kconfig"
 371
 372source "arch/arm/mach-berlin/Kconfig"
 373
 374source "arch/arm/mach-clps711x/Kconfig"
 375
 
 
 376source "arch/arm/mach-davinci/Kconfig"
 377
 378source "arch/arm/mach-digicolor/Kconfig"
 379
 380source "arch/arm/mach-dove/Kconfig"
 381
 382source "arch/arm/mach-ep93xx/Kconfig"
 383
 384source "arch/arm/mach-exynos/Kconfig"
 385
 386source "arch/arm/mach-footbridge/Kconfig"
 387
 388source "arch/arm/mach-gemini/Kconfig"
 389
 390source "arch/arm/mach-highbank/Kconfig"
 391
 392source "arch/arm/mach-hisi/Kconfig"
 393
 394source "arch/arm/mach-hpe/Kconfig"
 395
 396source "arch/arm/mach-imx/Kconfig"
 397
 
 
 
 
 398source "arch/arm/mach-ixp4xx/Kconfig"
 399
 400source "arch/arm/mach-keystone/Kconfig"
 401
 402source "arch/arm/mach-lpc32xx/Kconfig"
 403
 404source "arch/arm/mach-mediatek/Kconfig"
 405
 406source "arch/arm/mach-meson/Kconfig"
 407
 408source "arch/arm/mach-milbeaut/Kconfig"
 409
 410source "arch/arm/mach-mmp/Kconfig"
 411
 
 
 412source "arch/arm/mach-mstar/Kconfig"
 413
 414source "arch/arm/mach-mv78xx0/Kconfig"
 415
 416source "arch/arm/mach-mvebu/Kconfig"
 417
 418source "arch/arm/mach-mxs/Kconfig"
 419
 420source "arch/arm/mach-nomadik/Kconfig"
 421
 422source "arch/arm/mach-npcm/Kconfig"
 423
 
 
 
 
 424source "arch/arm/mach-omap1/Kconfig"
 425
 426source "arch/arm/mach-omap2/Kconfig"
 427
 428source "arch/arm/mach-orion5x/Kconfig"
 429
 
 
 430source "arch/arm/mach-pxa/Kconfig"
 
 431
 432source "arch/arm/mach-qcom/Kconfig"
 433
 
 
 434source "arch/arm/mach-realtek/Kconfig"
 435
 436source "arch/arm/mach-rpc/Kconfig"
 437
 438source "arch/arm/mach-rockchip/Kconfig"
 439
 440source "arch/arm/mach-s3c/Kconfig"
 441
 442source "arch/arm/mach-s5pv210/Kconfig"
 443
 444source "arch/arm/mach-sa1100/Kconfig"
 445
 446source "arch/arm/mach-shmobile/Kconfig"
 447
 448source "arch/arm/mach-socfpga/Kconfig"
 449
 450source "arch/arm/mach-spear/Kconfig"
 451
 452source "arch/arm/mach-sti/Kconfig"
 453
 454source "arch/arm/mach-stm32/Kconfig"
 455
 456source "arch/arm/mach-sunxi/Kconfig"
 457
 458source "arch/arm/mach-tegra/Kconfig"
 459
 
 
 460source "arch/arm/mach-ux500/Kconfig"
 461
 462source "arch/arm/mach-versatile/Kconfig"
 463
 
 
 464source "arch/arm/mach-vt8500/Kconfig"
 465
 466source "arch/arm/mach-zynq/Kconfig"
 467
 468# ARMv7-M architecture
 469config ARCH_LPC18XX
 470	bool "NXP LPC18xx/LPC43xx"
 471	depends on ARM_SINGLE_ARMV7M
 472	select ARCH_HAS_RESET_CONTROLLER
 473	select ARM_AMBA
 474	select CLKSRC_LPC32XX
 475	select PINCTRL
 476	help
 477	  Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
 478	  high performance microcontrollers.
 479
 480config ARCH_MPS2
 481	bool "ARM MPS2 platform"
 482	depends on ARM_SINGLE_ARMV7M
 483	select ARM_AMBA
 484	select CLKSRC_MPS2
 485	help
 486	  Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
 487	  with a range of available cores like Cortex-M3/M4/M7.
 488
 489	  Please, note that depends which Application Note is used memory map
 490	  for the platform may vary, so adjustment of RAM base might be needed.
 491
 492# Definitions to make life easier
 493config ARCH_ACORN
 494	bool
 495
 
 
 
 496config PLAT_ORION
 497	bool
 498	select CLKSRC_MMIO
 
 499	select GENERIC_IRQ_CHIP
 500	select IRQ_DOMAIN
 501
 502config PLAT_ORION_LEGACY
 503	bool
 504	select PLAT_ORION
 505
 
 
 
 506config PLAT_VERSATILE
 507	bool
 508
 509source "arch/arm/mm/Kconfig"
 510
 511config IWMMXT
 512	bool "Enable iWMMXt support"
 513	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
 514	default y if PXA27x || PXA3xx || ARCH_MMP
 515	help
 516	  Enable support for iWMMXt context switching at run time if
 517	  running on a CPU that supports it.
 518
 519if !MMU
 520source "arch/arm/Kconfig-nommu"
 521endif
 522
 523config PJ4B_ERRATA_4742
 524	bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
 525	depends on CPU_PJ4B && MACH_ARMADA_370
 526	default y
 527	help
 528	  When coming out of either a Wait for Interrupt (WFI) or a Wait for
 529	  Event (WFE) IDLE states, a specific timing sensitivity exists between
 530	  the retiring WFI/WFE instructions and the newly issued subsequent
 531	  instructions.  This sensitivity can result in a CPU hang scenario.
 532	  Workaround:
 533	  The software must insert either a Data Synchronization Barrier (DSB)
 534	  or Data Memory Barrier (DMB) command immediately after the WFI/WFE
 535	  instruction
 536
 537config ARM_ERRATA_326103
 538	bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
 539	depends on CPU_V6
 540	help
 541	  Executing a SWP instruction to read-only memory does not set bit 11
 542	  of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
 543	  treat the access as a read, preventing a COW from occurring and
 544	  causing the faulting task to livelock.
 545
 546config ARM_ERRATA_411920
 547	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
 548	depends on CPU_V6 || CPU_V6K
 549	help
 550	  Invalidation of the Instruction Cache operation can
 551	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
 552	  It does not affect the MPCore. This option enables the ARM Ltd.
 553	  recommended workaround.
 554
 555config ARM_ERRATA_430973
 556	bool "ARM errata: Stale prediction on replaced interworking branch"
 557	depends on CPU_V7
 558	help
 559	  This option enables the workaround for the 430973 Cortex-A8
 560	  r1p* erratum. If a code sequence containing an ARM/Thumb
 561	  interworking branch is replaced with another code sequence at the
 562	  same virtual address, whether due to self-modifying code or virtual
 563	  to physical address re-mapping, Cortex-A8 does not recover from the
 564	  stale interworking branch prediction. This results in Cortex-A8
 565	  executing the new code sequence in the incorrect ARM or Thumb state.
 566	  The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
 567	  and also flushes the branch target cache at every context switch.
 568	  Note that setting specific bits in the ACTLR register may not be
 569	  available in non-secure mode.
 570
 571config ARM_ERRATA_458693
 572	bool "ARM errata: Processor deadlock when a false hazard is created"
 573	depends on CPU_V7
 574	depends on !ARCH_MULTIPLATFORM
 575	help
 576	  This option enables the workaround for the 458693 Cortex-A8 (r2p0)
 577	  erratum. For very specific sequences of memory operations, it is
 578	  possible for a hazard condition intended for a cache line to instead
 579	  be incorrectly associated with a different cache line. This false
 580	  hazard might then cause a processor deadlock. The workaround enables
 581	  the L1 caching of the NEON accesses and disables the PLD instruction
 582	  in the ACTLR register. Note that setting specific bits in the ACTLR
 583	  register may not be available in non-secure mode and thus is not
 584	  available on a multiplatform kernel. This should be applied by the
 585	  bootloader instead.
 586
 587config ARM_ERRATA_460075
 588	bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
 589	depends on CPU_V7
 590	depends on !ARCH_MULTIPLATFORM
 591	help
 592	  This option enables the workaround for the 460075 Cortex-A8 (r2p0)
 593	  erratum. Any asynchronous access to the L2 cache may encounter a
 594	  situation in which recent store transactions to the L2 cache are lost
 595	  and overwritten with stale memory contents from external memory. The
 596	  workaround disables the write-allocate mode for the L2 cache via the
 597	  ACTLR register. Note that setting specific bits in the ACTLR register
 598	  may not be available in non-secure mode and thus is not available on
 599	  a multiplatform kernel. This should be applied by the bootloader
 600	  instead.
 601
 602config ARM_ERRATA_742230
 603	bool "ARM errata: DMB operation may be faulty"
 604	depends on CPU_V7 && SMP
 605	depends on !ARCH_MULTIPLATFORM
 606	help
 607	  This option enables the workaround for the 742230 Cortex-A9
 608	  (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
 609	  between two write operations may not ensure the correct visibility
 610	  ordering of the two writes. This workaround sets a specific bit in
 611	  the diagnostic register of the Cortex-A9 which causes the DMB
 612	  instruction to behave as a DSB, ensuring the correct behaviour of
 613	  the two writes. Note that setting specific bits in the diagnostics
 614	  register may not be available in non-secure mode and thus is not
 615	  available on a multiplatform kernel. This should be applied by the
 616	  bootloader instead.
 617
 618config ARM_ERRATA_742231
 619	bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
 620	depends on CPU_V7 && SMP
 621	depends on !ARCH_MULTIPLATFORM
 622	help
 623	  This option enables the workaround for the 742231 Cortex-A9
 624	  (r2p0..r2p2) erratum. Under certain conditions, specific to the
 625	  Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
 626	  accessing some data located in the same cache line, may get corrupted
 627	  data due to bad handling of the address hazard when the line gets
 628	  replaced from one of the CPUs at the same time as another CPU is
 629	  accessing it. This workaround sets specific bits in the diagnostic
 630	  register of the Cortex-A9 which reduces the linefill issuing
 631	  capabilities of the processor. Note that setting specific bits in the
 632	  diagnostics register may not be available in non-secure mode and thus
 633	  is not available on a multiplatform kernel. This should be applied by
 634	  the bootloader instead.
 635
 636config ARM_ERRATA_643719
 637	bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
 638	depends on CPU_V7 && SMP
 639	default y
 640	help
 641	  This option enables the workaround for the 643719 Cortex-A9 (prior to
 642	  r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
 643	  register returns zero when it should return one. The workaround
 644	  corrects this value, ensuring cache maintenance operations which use
 645	  it behave as intended and avoiding data corruption.
 646
 647config ARM_ERRATA_720789
 648	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
 649	depends on CPU_V7
 650	help
 651	  This option enables the workaround for the 720789 Cortex-A9 (prior to
 652	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
 653	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
 654	  As a consequence of this erratum, some TLB entries which should be
 655	  invalidated are not, resulting in an incoherency in the system page
 656	  tables. The workaround changes the TLB flushing routines to invalidate
 657	  entries regardless of the ASID.
 658
 659config ARM_ERRATA_743622
 660	bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
 661	depends on CPU_V7
 662	depends on !ARCH_MULTIPLATFORM
 663	help
 664	  This option enables the workaround for the 743622 Cortex-A9
 665	  (r2p*) erratum. Under very rare conditions, a faulty
 666	  optimisation in the Cortex-A9 Store Buffer may lead to data
 667	  corruption. This workaround sets a specific bit in the diagnostic
 668	  register of the Cortex-A9 which disables the Store Buffer
 669	  optimisation, preventing the defect from occurring. This has no
 670	  visible impact on the overall performance or power consumption of the
 671	  processor. Note that setting specific bits in the diagnostics register
 672	  may not be available in non-secure mode and thus is not available on a
 673	  multiplatform kernel. This should be applied by the bootloader instead.
 674
 675config ARM_ERRATA_751472
 676	bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
 677	depends on CPU_V7
 678	depends on !ARCH_MULTIPLATFORM
 679	help
 680	  This option enables the workaround for the 751472 Cortex-A9 (prior
 681	  to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
 682	  completion of a following broadcasted operation if the second
 683	  operation is received by a CPU before the ICIALLUIS has completed,
 684	  potentially leading to corrupted entries in the cache or TLB.
 685	  Note that setting specific bits in the diagnostics register may
 686	  not be available in non-secure mode and thus is not available on
 687	  a multiplatform kernel. This should be applied by the bootloader
 688	  instead.
 689
 690config ARM_ERRATA_754322
 691	bool "ARM errata: possible faulty MMU translations following an ASID switch"
 692	depends on CPU_V7
 693	help
 694	  This option enables the workaround for the 754322 Cortex-A9 (r2p*,
 695	  r3p*) erratum. A speculative memory access may cause a page table walk
 696	  which starts prior to an ASID switch but completes afterwards. This
 697	  can populate the micro-TLB with a stale entry which may be hit with
 698	  the new ASID. This workaround places two dsb instructions in the mm
 699	  switching code so that no page table walks can cross the ASID switch.
 700
 701config ARM_ERRATA_754327
 702	bool "ARM errata: no automatic Store Buffer drain"
 703	depends on CPU_V7 && SMP
 704	help
 705	  This option enables the workaround for the 754327 Cortex-A9 (prior to
 706	  r2p0) erratum. The Store Buffer does not have any automatic draining
 707	  mechanism and therefore a livelock may occur if an external agent
 708	  continuously polls a memory location waiting to observe an update.
 709	  This workaround defines cpu_relax() as smp_mb(), preventing correctly
 710	  written polling loops from denying visibility of updates to memory.
 711
 712config ARM_ERRATA_364296
 713	bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
 714	depends on CPU_V6
 715	help
 716	  This options enables the workaround for the 364296 ARM1136
 717	  r0p2 erratum (possible cache data corruption with
 718	  hit-under-miss enabled). It sets the undocumented bit 31 in
 719	  the auxiliary control register and the FI bit in the control
 720	  register, thus disabling hit-under-miss without putting the
 721	  processor into full low interrupt latency mode. ARM11MPCore
 722	  is not affected.
 723
 724config ARM_ERRATA_764369
 725	bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
 726	depends on CPU_V7 && SMP
 727	help
 728	  This option enables the workaround for erratum 764369
 729	  affecting Cortex-A9 MPCore with two or more processors (all
 730	  current revisions). Under certain timing circumstances, a data
 731	  cache line maintenance operation by MVA targeting an Inner
 732	  Shareable memory region may fail to proceed up to either the
 733	  Point of Coherency or to the Point of Unification of the
 734	  system. This workaround adds a DSB instruction before the
 735	  relevant cache maintenance functions and sets a specific bit
 736	  in the diagnostic control register of the SCU.
 737
 738config ARM_ERRATA_764319
 739	bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction"
 740	depends on CPU_V7
 741	help
 742	  This option enables the workaround for the 764319 Cortex-A9 erratum.
 743	  CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an
 744	  unexpected Undefined Instruction exception when the DBGSWENABLE
 745	  external pin is set to 0, even when the CP14 accesses are performed
 746	  from a privileged mode. This work around catches the exception in a
 747	  way the kernel does not stop execution.
 748
 749config ARM_ERRATA_775420
 750       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
 751       depends on CPU_V7
 752       help
 753	 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
 754	 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
 755	 operation aborts with MMU exception, it might cause the processor
 756	 to deadlock. This workaround puts DSB before executing ISB if
 757	 an abort may occur on cache maintenance.
 758
 759config ARM_ERRATA_798181
 760	bool "ARM errata: TLBI/DSB failure on Cortex-A15"
 761	depends on CPU_V7 && SMP
 762	help
 763	  On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
 764	  adequately shooting down all use of the old entries. This
 765	  option enables the Linux kernel workaround for this erratum
 766	  which sends an IPI to the CPUs that are running the same ASID
 767	  as the one being invalidated.
 768
 769config ARM_ERRATA_773022
 770	bool "ARM errata: incorrect instructions may be executed from loop buffer"
 771	depends on CPU_V7
 772	help
 773	  This option enables the workaround for the 773022 Cortex-A15
 774	  (up to r0p4) erratum. In certain rare sequences of code, the
 775	  loop buffer may deliver incorrect instructions. This
 776	  workaround disables the loop buffer to avoid the erratum.
 777
 778config ARM_ERRATA_818325_852422
 779	bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
 780	depends on CPU_V7
 781	help
 782	  This option enables the workaround for:
 783	  - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
 784	    instruction might deadlock.  Fixed in r0p1.
 785	  - Cortex-A12 852422: Execution of a sequence of instructions might
 786	    lead to either a data corruption or a CPU deadlock.  Not fixed in
 787	    any Cortex-A12 cores yet.
 788	  This workaround for all both errata involves setting bit[12] of the
 789	  Feature Register. This bit disables an optimisation applied to a
 790	  sequence of 2 instructions that use opposing condition codes.
 791
 792config ARM_ERRATA_821420
 793	bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
 794	depends on CPU_V7
 795	help
 796	  This option enables the workaround for the 821420 Cortex-A12
 797	  (all revs) erratum. In very rare timing conditions, a sequence
 798	  of VMOV to Core registers instructions, for which the second
 799	  one is in the shadow of a branch or abort, can lead to a
 800	  deadlock when the VMOV instructions are issued out-of-order.
 801
 802config ARM_ERRATA_825619
 803	bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
 804	depends on CPU_V7
 805	help
 806	  This option enables the workaround for the 825619 Cortex-A12
 807	  (all revs) erratum. Within rare timing constraints, executing a
 808	  DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
 809	  and Device/Strongly-Ordered loads and stores might cause deadlock
 810
 811config ARM_ERRATA_857271
 812	bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
 813	depends on CPU_V7
 814	help
 815	  This option enables the workaround for the 857271 Cortex-A12
 816	  (all revs) erratum. Under very rare timing conditions, the CPU might
 817	  hang. The workaround is expected to have a < 1% performance impact.
 818
 819config ARM_ERRATA_852421
 820	bool "ARM errata: A17: DMB ST might fail to create order between stores"
 821	depends on CPU_V7
 822	help
 823	  This option enables the workaround for the 852421 Cortex-A17
 824	  (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
 825	  execution of a DMB ST instruction might fail to properly order
 826	  stores from GroupA and stores from GroupB.
 827
 828config ARM_ERRATA_852423
 829	bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
 830	depends on CPU_V7
 831	help
 832	  This option enables the workaround for:
 833	  - Cortex-A17 852423: Execution of a sequence of instructions might
 834	    lead to either a data corruption or a CPU deadlock.  Not fixed in
 835	    any Cortex-A17 cores yet.
 836	  This is identical to Cortex-A12 erratum 852422.  It is a separate
 837	  config option from the A12 erratum due to the way errata are checked
 838	  for and handled.
 839
 840config ARM_ERRATA_857272
 841	bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
 842	depends on CPU_V7
 843	help
 844	  This option enables the workaround for the 857272 Cortex-A17 erratum.
 845	  This erratum is not known to be fixed in any A17 revision.
 846	  This is identical to Cortex-A12 erratum 857271.  It is a separate
 847	  config option from the A12 erratum due to the way errata are checked
 848	  for and handled.
 849
 850endmenu
 851
 852source "arch/arm/common/Kconfig"
 853
 854menu "Bus support"
 855
 856config ISA
 857	bool
 858	help
 859	  Find out whether you have ISA slots on your motherboard.  ISA is the
 860	  name of a bus system, i.e. the way the CPU talks to the other stuff
 861	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
 862	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
 863	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
 864
 
 
 
 
 
 865# Select ISA DMA interface
 866config ISA_DMA_API
 867	bool
 868
 
 
 
 
 
 
 869config ARM_ERRATA_814220
 870	bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
 871	depends on CPU_V7
 872	help
 873	  The v7 ARM states that all cache and branch predictor maintenance
 874	  operations that do not specify an address execute, relative to
 875	  each other, in program order.
 876	  However, because of this erratum, an L2 set/way cache maintenance
 877	  operation can overtake an L1 set/way cache maintenance operation.
 878	  This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
 879	  r0p4, r0p5.
 880
 881endmenu
 882
 883menu "Kernel Features"
 884
 885config HAVE_SMP
 886	bool
 887	help
 888	  This option should be selected by machines which have an SMP-
 889	  capable CPU.
 890
 891	  The only effect of this option is to make the SMP-related
 892	  options available to the user for configuration.
 893
 894config SMP
 895	bool "Symmetric Multi-Processing"
 896	depends on CPU_V6K || CPU_V7
 897	depends on HAVE_SMP
 898	depends on MMU || ARM_MPU
 899	select IRQ_WORK
 900	help
 901	  This enables support for systems with more than one CPU. If you have
 902	  a system with only one CPU, say N. If you have a system with more
 903	  than one CPU, say Y.
 904
 905	  If you say N here, the kernel will run on uni- and multiprocessor
 906	  machines, but will use only one CPU of a multiprocessor machine. If
 907	  you say Y here, the kernel will run on many, but not all,
 908	  uniprocessor machines. On a uniprocessor machine, the kernel
 909	  will run faster if you say N here.
 910
 911	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
 912	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
 913	  <http://tldp.org/HOWTO/SMP-HOWTO.html>.
 914
 915	  If you don't know what to do here, say N.
 916
 917config SMP_ON_UP
 918	bool "Allow booting SMP kernel on uniprocessor systems"
 919	depends on SMP && MMU
 920	default y
 921	help
 922	  SMP kernels contain instructions which fail on non-SMP processors.
 923	  Enabling this option allows the kernel to modify itself to make
 924	  these instructions safe.  Disabling it allows about 1K of space
 925	  savings.
 926
 927	  If you don't know what to do here, say Y.
 928
 929
 930config CURRENT_POINTER_IN_TPIDRURO
 931	def_bool y
 932	depends on CPU_32v6K && !CPU_V6
 933
 934config IRQSTACKS
 935	def_bool y
 936	select HAVE_IRQ_EXIT_ON_IRQ_STACK
 937	select HAVE_SOFTIRQ_ON_OWN_STACK
 938
 939config ARM_CPU_TOPOLOGY
 940	bool "Support cpu topology definition"
 941	depends on SMP && CPU_V7
 942	default y
 943	help
 944	  Support ARM cpu topology definition. The MPIDR register defines
 945	  affinity between processors which is then used to describe the cpu
 946	  topology of an ARM System.
 947
 948config SCHED_MC
 949	bool "Multi-core scheduler support"
 950	depends on ARM_CPU_TOPOLOGY
 951	help
 952	  Multi-core scheduler support improves the CPU scheduler's decision
 953	  making when dealing with multi-core CPU chips at a cost of slightly
 954	  increased overhead in some places. If unsure say N here.
 955
 956config SCHED_SMT
 957	bool "SMT scheduler support"
 958	depends on ARM_CPU_TOPOLOGY
 959	help
 960	  Improves the CPU scheduler's decision making when dealing with
 961	  MultiThreading at a cost of slightly increased overhead in some
 962	  places. If unsure say N here.
 963
 964config HAVE_ARM_SCU
 965	bool
 966	help
 967	  This option enables support for the ARM snoop control unit
 968
 969config HAVE_ARM_ARCH_TIMER
 970	bool "Architected timer support"
 971	depends on CPU_V7
 972	select ARM_ARCH_TIMER
 973	help
 974	  This option enables support for the ARM architected timer
 975
 976config HAVE_ARM_TWD
 977	bool
 978	help
 979	  This options enables support for the ARM timer and watchdog unit
 980
 981config MCPM
 982	bool "Multi-Cluster Power Management"
 983	depends on CPU_V7 && SMP
 984	help
 985	  This option provides the common power management infrastructure
 986	  for (multi-)cluster based systems, such as big.LITTLE based
 987	  systems.
 988
 989config MCPM_QUAD_CLUSTER
 990	bool
 991	depends on MCPM
 992	help
 993	  To avoid wasting resources unnecessarily, MCPM only supports up
 994	  to 2 clusters by default.
 995	  Platforms with 3 or 4 clusters that use MCPM must select this
 996	  option to allow the additional clusters to be managed.
 997
 998config BIG_LITTLE
 999	bool "big.LITTLE support (Experimental)"
1000	depends on CPU_V7 && SMP
1001	select MCPM
1002	help
1003	  This option enables support selections for the big.LITTLE
1004	  system architecture.
1005
1006config BL_SWITCHER
1007	bool "big.LITTLE switcher support"
1008	depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1009	select CPU_PM
1010	help
1011	  The big.LITTLE "switcher" provides the core functionality to
1012	  transparently handle transition between a cluster of A15's
1013	  and a cluster of A7's in a big.LITTLE system.
1014
1015config BL_SWITCHER_DUMMY_IF
1016	tristate "Simple big.LITTLE switcher user interface"
1017	depends on BL_SWITCHER && DEBUG_KERNEL
1018	help
1019	  This is a simple and dummy char dev interface to control
1020	  the big.LITTLE switcher core code.  It is meant for
1021	  debugging purposes only.
1022
1023choice
1024	prompt "Memory split"
1025	depends on MMU
1026	default VMSPLIT_3G
1027	help
1028	  Select the desired split between kernel and user memory.
1029
1030	  If you are not absolutely sure what you are doing, leave this
1031	  option alone!
1032
1033	config VMSPLIT_3G
1034		bool "3G/1G user/kernel split"
1035	config VMSPLIT_3G_OPT
1036		depends on !ARM_LPAE
1037		bool "3G/1G user/kernel split (for full 1G low memory)"
1038	config VMSPLIT_2G
1039		bool "2G/2G user/kernel split"
1040	config VMSPLIT_1G
1041		bool "1G/3G user/kernel split"
1042endchoice
1043
1044config PAGE_OFFSET
1045	hex
1046	default PHYS_OFFSET if !MMU
1047	default 0x40000000 if VMSPLIT_1G
1048	default 0x80000000 if VMSPLIT_2G
1049	default 0xB0000000 if VMSPLIT_3G_OPT
1050	default 0xC0000000
1051
1052config KASAN_SHADOW_OFFSET
1053	hex
1054	depends on KASAN
1055	default 0x1f000000 if PAGE_OFFSET=0x40000000
1056	default 0x5f000000 if PAGE_OFFSET=0x80000000
1057	default 0x9f000000 if PAGE_OFFSET=0xC0000000
1058	default 0x8f000000 if PAGE_OFFSET=0xB0000000
1059	default 0xffffffff
1060
1061config NR_CPUS
1062	int "Maximum number of CPUs (2-32)"
1063	range 2 16 if DEBUG_KMAP_LOCAL
1064	range 2 32 if !DEBUG_KMAP_LOCAL
1065	depends on SMP
1066	default "4"
1067	help
1068	  The maximum number of CPUs that the kernel can support.
1069	  Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1070	  debugging is enabled, which uses half of the per-CPU fixmap
1071	  slots as guard regions.
1072
1073config HOTPLUG_CPU
1074	bool "Support for hot-pluggable CPUs"
1075	depends on SMP
1076	select GENERIC_IRQ_MIGRATION
1077	help
1078	  Say Y here to experiment with turning CPUs off and on.  CPUs
1079	  can be controlled through /sys/devices/system/cpu.
1080
1081config ARM_PSCI
1082	bool "Support for the ARM Power State Coordination Interface (PSCI)"
1083	depends on HAVE_ARM_SMCCC
1084	select ARM_PSCI_FW
1085	help
1086	  Say Y here if you want Linux to communicate with system firmware
1087	  implementing the PSCI specification for CPU-centric power
1088	  management operations described in ARM document number ARM DEN
1089	  0022A ("Power State Coordination Interface System Software on
1090	  ARM processors").
1091
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1092config HZ_FIXED
1093	int
1094	default 128 if SOC_AT91RM9200
1095	default 0
1096
1097choice
1098	depends on HZ_FIXED = 0
1099	prompt "Timer frequency"
1100
1101config HZ_100
1102	bool "100 Hz"
1103
1104config HZ_200
1105	bool "200 Hz"
1106
1107config HZ_250
1108	bool "250 Hz"
1109
1110config HZ_300
1111	bool "300 Hz"
1112
1113config HZ_500
1114	bool "500 Hz"
1115
1116config HZ_1000
1117	bool "1000 Hz"
1118
1119endchoice
1120
1121config HZ
1122	int
1123	default HZ_FIXED if HZ_FIXED != 0
1124	default 100 if HZ_100
1125	default 200 if HZ_200
1126	default 250 if HZ_250
1127	default 300 if HZ_300
1128	default 500 if HZ_500
1129	default 1000
1130
1131config SCHED_HRTICK
1132	def_bool HIGH_RES_TIMERS
1133
1134config THUMB2_KERNEL
1135	bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1136	depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1137	default y if CPU_THUMBONLY
1138	select ARM_UNWIND
1139	help
1140	  By enabling this option, the kernel will be compiled in
1141	  Thumb-2 mode.
1142
1143	  If unsure, say N.
1144
1145config ARM_PATCH_IDIV
1146	bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1147	depends on CPU_32v7
1148	default y
1149	help
1150	  The ARM compiler inserts calls to __aeabi_idiv() and
1151	  __aeabi_uidiv() when it needs to perform division on signed
1152	  and unsigned integers. Some v7 CPUs have support for the sdiv
1153	  and udiv instructions that can be used to implement those
1154	  functions.
1155
1156	  Enabling this option allows the kernel to modify itself to
1157	  replace the first two instructions of these library functions
1158	  with the sdiv or udiv plus "bx lr" instructions when the CPU
1159	  it is running on supports them. Typically this will be faster
1160	  and less power intensive than running the original library
1161	  code to do integer division.
1162
1163config AEABI
1164	bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1165		!CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1166	default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1167	help
1168	  This option allows for the kernel to be compiled using the latest
1169	  ARM ABI (aka EABI).  This is only useful if you are using a user
1170	  space environment that is also compiled with EABI.
1171
1172	  Since there are major incompatibilities between the legacy ABI and
1173	  EABI, especially with regard to structure member alignment, this
1174	  option also changes the kernel syscall calling convention to
1175	  disambiguate both ABIs and allow for backward compatibility support
1176	  (selected with CONFIG_OABI_COMPAT).
1177
1178	  To use this you need GCC version 4.0.0 or later.
1179
1180config OABI_COMPAT
1181	bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1182	depends on AEABI && !THUMB2_KERNEL
1183	help
1184	  This option preserves the old syscall interface along with the
1185	  new (ARM EABI) one. It also provides a compatibility layer to
1186	  intercept syscalls that have structure arguments which layout
1187	  in memory differs between the legacy ABI and the new ARM EABI
1188	  (only for non "thumb" binaries). This option adds a tiny
1189	  overhead to all syscalls and produces a slightly larger kernel.
1190
1191	  The seccomp filter system will not be available when this is
1192	  selected, since there is no way yet to sensibly distinguish
1193	  between calling conventions during filtering.
1194
1195	  If you know you'll be using only pure EABI user space then you
1196	  can say N here. If this option is not selected and you attempt
1197	  to execute a legacy ABI binary then the result will be
1198	  UNPREDICTABLE (in fact it can be predicted that it won't work
1199	  at all). If in doubt say N.
1200
1201config ARCH_SELECT_MEMORY_MODEL
1202	def_bool y
1203
1204config ARCH_FLATMEM_ENABLE
1205	def_bool !(ARCH_RPC || ARCH_SA1100)
1206
1207config ARCH_SPARSEMEM_ENABLE
1208	def_bool !ARCH_FOOTBRIDGE
1209	select SPARSEMEM_STATIC if SPARSEMEM
1210
1211config HIGHMEM
1212	bool "High Memory Support"
1213	depends on MMU
1214	select KMAP_LOCAL
1215	select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY
1216	help
1217	  The address space of ARM processors is only 4 Gigabytes large
1218	  and it has to accommodate user address space, kernel address
1219	  space as well as some memory mapped IO. That means that, if you
1220	  have a large amount of physical memory and/or IO, not all of the
1221	  memory can be "permanently mapped" by the kernel. The physical
1222	  memory that is not permanently mapped is called "high memory".
1223
1224	  Depending on the selected kernel/user memory split, minimum
1225	  vmalloc space and actual amount of RAM, you may not need this
1226	  option which should result in a slightly faster kernel.
1227
1228	  If unsure, say n.
1229
1230config HIGHPTE
1231	bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1232	depends on HIGHMEM
1233	default y
1234	help
1235	  The VM uses one page of physical memory for each page table.
1236	  For systems with a lot of processes, this can use a lot of
1237	  precious low memory, eventually leading to low memory being
1238	  consumed by page tables.  Setting this option will allow
1239	  user-space 2nd level page tables to reside in high memory.
1240
1241config ARM_PAN
1242	bool "Enable privileged no-access"
1243	depends on MMU
1244	default y
1245	help
1246	  Increase kernel security by ensuring that normal kernel accesses
1247	  are unable to access userspace addresses.  This can help prevent
1248	  use-after-free bugs becoming an exploitable privilege escalation
1249	  by ensuring that magic values (such as LIST_POISON) will always
1250	  fault when dereferenced.
1251
1252	  The implementation uses CPU domains when !CONFIG_ARM_LPAE and
1253	  disabling of TTBR0 page table walks with CONFIG_ARM_LPAE.
1254
1255config CPU_SW_DOMAIN_PAN
1256	def_bool y
1257	depends on ARM_PAN && !ARM_LPAE
1258	help
1259	  Enable use of CPU domains to implement privileged no-access.
1260
1261	  CPUs with low-vector mappings use a best-efforts implementation.
1262	  Their lower 1MB needs to remain accessible for the vectors, but
1263	  the remainder of userspace will become appropriately inaccessible.
1264
1265config CPU_TTBR0_PAN
1266	def_bool y
1267	depends on ARM_PAN && ARM_LPAE
1268	help
1269	  Enable privileged no-access by disabling TTBR0 page table walks when
1270	  running in kernel mode.
1271
1272config HW_PERF_EVENTS
1273	def_bool y
1274	depends on ARM_PMU
1275
 
 
 
1276config ARM_MODULE_PLTS
1277	bool "Use PLTs to allow module memory to spill over into vmalloc area"
1278	depends on MODULES
1279	select KASAN_VMALLOC if KASAN
1280	default y
1281	help
1282	  Allocate PLTs when loading modules so that jumps and calls whose
1283	  targets are too far away for their relative offsets to be encoded
1284	  in the instructions themselves can be bounced via veneers in the
1285	  module's PLT. This allows modules to be allocated in the generic
1286	  vmalloc area after the dedicated module memory area has been
1287	  exhausted. The modules will use slightly more memory, but after
1288	  rounding up to page size, the actual memory footprint is usually
1289	  the same.
1290
1291	  Disabling this is usually safe for small single-platform
1292	  configurations. If unsure, say y.
1293
1294config ARCH_FORCE_MAX_ORDER
1295	int "Order of maximal physically contiguous allocations"
1296	default "11" if SOC_AM33XX
1297	default "8" if SA1111
1298	default "10"
1299	help
1300	  The kernel page allocator limits the size of maximal physically
1301	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
1302	  defines the maximal power of two of number of pages that can be
1303	  allocated as a single contiguous block. This option allows
1304	  overriding the default setting when ability to allocate very
1305	  large blocks of physically contiguous memory is required.
1306
1307	  Don't change if unsure.
 
1308
1309config ALIGNMENT_TRAP
1310	def_bool CPU_CP15_MMU
1311	select HAVE_PROC_CPU if PROC_FS
1312	help
1313	  ARM processors cannot fetch/store information which is not
1314	  naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1315	  address divisible by 4. On 32-bit ARM processors, these non-aligned
1316	  fetch/store instructions will be emulated in software if you say
1317	  here, which has a severe performance impact. This is necessary for
1318	  correct operation of some network protocols. With an IP-only
1319	  configuration it is safe to say N, otherwise say Y.
1320
1321config UACCESS_WITH_MEMCPY
1322	bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1323	depends on MMU
1324	default y if CPU_FEROCEON
1325	help
1326	  Implement faster copy_to_user and clear_user methods for CPU
1327	  cores where a 8-word STM instruction give significantly higher
1328	  memory write throughput than a sequence of individual 32bit stores.
1329
1330	  A possible side effect is a slight increase in scheduling latency
1331	  between threads sharing the same address space if they invoke
1332	  such copy operations with large buffers.
1333
1334	  However, if the CPU data cache is using a write-allocate mode,
1335	  this option is unlikely to provide any performance gain.
1336
1337config PARAVIRT
1338	bool "Enable paravirtualization code"
1339	help
1340	  This changes the kernel so it can modify itself when it is run
1341	  under a hypervisor, potentially improving performance significantly
1342	  over full virtualization.
1343
1344config PARAVIRT_TIME_ACCOUNTING
1345	bool "Paravirtual steal time accounting"
1346	select PARAVIRT
1347	help
1348	  Select this option to enable fine granularity task steal time
1349	  accounting. Time spent executing other tasks in parallel with
1350	  the current vCPU is discounted from the vCPU power. To account for
1351	  that, there can be a small performance impact.
1352
1353	  If in doubt, say N here.
1354
1355config XEN_DOM0
1356	def_bool y
1357	depends on XEN
1358
1359config XEN
1360	bool "Xen guest support on ARM"
1361	depends on ARM && AEABI && OF
1362	depends on CPU_V7 && !CPU_V6
1363	depends on !GENERIC_ATOMIC64
1364	depends on MMU
1365	select ARCH_DMA_ADDR_T_64BIT
1366	select ARM_PSCI
1367	select SWIOTLB
1368	select SWIOTLB_XEN
1369	select PARAVIRT
1370	help
1371	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1372
1373config CC_HAVE_STACKPROTECTOR_TLS
1374	def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0)
1375
1376config STACKPROTECTOR_PER_TASK
1377	bool "Use a unique stack canary value for each task"
1378	depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA
1379	depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS
1380	select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS
1381	default y
1382	help
1383	  Due to the fact that GCC uses an ordinary symbol reference from
1384	  which to load the value of the stack canary, this value can only
1385	  change at reboot time on SMP systems, and all tasks running in the
1386	  kernel's address space are forced to use the same canary value for
1387	  the entire duration that the system is up.
1388
1389	  Enable this option to switch to a different method that uses a
1390	  different canary value for each task.
1391
1392endmenu
1393
1394menu "Boot options"
1395
1396config USE_OF
1397	bool "Flattened Device Tree support"
1398	select IRQ_DOMAIN
1399	select OF
1400	help
1401	  Include support for flattened device tree machine descriptions.
1402
1403config ARCH_WANT_FLAT_DTB_INSTALL
1404	def_bool y
1405
1406config ATAGS
1407	bool "Support for the traditional ATAGS boot data passing"
1408	default y
1409	help
1410	  This is the traditional way of passing data to the kernel at boot
1411	  time. If you are solely relying on the flattened device tree (or
1412	  the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1413	  to remove ATAGS support from your kernel binary.
 
1414
1415config DEPRECATED_PARAM_STRUCT
1416	bool "Provide old way to pass kernel parameters"
1417	depends on ATAGS
1418	help
1419	  This was deprecated in 2001 and announced to live on for 5 years.
1420	  Some old boot loaders still use this way.
1421
1422# Compressed boot loader in ROM.  Yes, we really want to ask about
1423# TEXT and BSS so we preserve their values in the config files.
1424config ZBOOT_ROM_TEXT
1425	hex "Compressed ROM boot loader base address"
1426	default 0x0
1427	help
1428	  The physical address at which the ROM-able zImage is to be
1429	  placed in the target.  Platforms which normally make use of
1430	  ROM-able zImage formats normally set this to a suitable
1431	  value in their defconfig file.
1432
1433	  If ZBOOT_ROM is not enabled, this has no effect.
1434
1435config ZBOOT_ROM_BSS
1436	hex "Compressed ROM boot loader BSS address"
1437	default 0x0
1438	help
1439	  The base address of an area of read/write memory in the target
1440	  for the ROM-able zImage which must be available while the
1441	  decompressor is running. It must be large enough to hold the
1442	  entire decompressed kernel plus an additional 128 KiB.
1443	  Platforms which normally make use of ROM-able zImage formats
1444	  normally set this to a suitable value in their defconfig file.
1445
1446	  If ZBOOT_ROM is not enabled, this has no effect.
1447
1448config ZBOOT_ROM
1449	bool "Compressed boot loader in ROM/flash"
1450	depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1451	depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1452	help
1453	  Say Y here if you intend to execute your compressed kernel image
1454	  (zImage) directly from ROM or flash.  If unsure, say N.
1455
1456config ARM_APPENDED_DTB
1457	bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1458	depends on OF
1459	help
1460	  With this option, the boot code will look for a device tree binary
1461	  (DTB) appended to zImage
1462	  (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1463
1464	  This is meant as a backward compatibility convenience for those
1465	  systems with a bootloader that can't be upgraded to accommodate
1466	  the documented boot protocol using a device tree.
1467
1468	  Beware that there is very little in terms of protection against
1469	  this option being confused by leftover garbage in memory that might
1470	  look like a DTB header after a reboot if no actual DTB is appended
1471	  to zImage.  Do not leave this option active in a production kernel
1472	  if you don't intend to always append a DTB.  Proper passing of the
1473	  location into r2 of a bootloader provided DTB is always preferable
1474	  to this option.
1475
1476config ARM_ATAG_DTB_COMPAT
1477	bool "Supplement the appended DTB with traditional ATAG information"
1478	depends on ARM_APPENDED_DTB
1479	help
1480	  Some old bootloaders can't be updated to a DTB capable one, yet
1481	  they provide ATAGs with memory configuration, the ramdisk address,
1482	  the kernel cmdline string, etc.  Such information is dynamically
1483	  provided by the bootloader and can't always be stored in a static
1484	  DTB.  To allow a device tree enabled kernel to be used with such
1485	  bootloaders, this option allows zImage to extract the information
1486	  from the ATAG list and store it at run time into the appended DTB.
1487
1488choice
1489	prompt "Kernel command line type"
1490	depends on ARM_ATAG_DTB_COMPAT
1491	default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1492
1493config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1494	bool "Use bootloader kernel arguments if available"
1495	help
1496	  Uses the command-line options passed by the boot loader instead of
1497	  the device tree bootargs property. If the boot loader doesn't provide
1498	  any, the device tree bootargs property will be used.
1499
1500config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1501	bool "Extend with bootloader kernel arguments"
1502	help
1503	  The command-line arguments provided by the boot loader will be
1504	  appended to the the device tree bootargs property.
1505
1506endchoice
1507
1508config CMDLINE
1509	string "Default kernel command string"
1510	default ""
1511	help
1512	  On some architectures (e.g. CATS), there is currently no way
1513	  for the boot loader to pass arguments to the kernel. For these
1514	  architectures, you should supply some command-line options at build
1515	  time by entering them here. As a minimum, you should specify the
1516	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
1517
1518choice
1519	prompt "Kernel command line type"
1520	depends on CMDLINE != ""
1521	default CMDLINE_FROM_BOOTLOADER
 
1522
1523config CMDLINE_FROM_BOOTLOADER
1524	bool "Use bootloader kernel arguments if available"
1525	help
1526	  Uses the command-line options passed by the boot loader. If
1527	  the boot loader doesn't provide any, the default kernel command
1528	  string provided in CMDLINE will be used.
1529
1530config CMDLINE_EXTEND
1531	bool "Extend bootloader kernel arguments"
1532	help
1533	  The command-line arguments provided by the boot loader will be
1534	  appended to the default kernel command string.
1535
1536config CMDLINE_FORCE
1537	bool "Always use the default kernel command string"
1538	help
1539	  Always use the default kernel command string, even if the boot
1540	  loader passes other arguments to the kernel.
1541	  This is useful if you cannot or don't want to change the
1542	  command-line options your boot loader passes to the kernel.
1543endchoice
1544
1545config XIP_KERNEL
1546	bool "Kernel Execute-In-Place from ROM"
1547	depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1548	depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP
1549	help
1550	  Execute-In-Place allows the kernel to run from non-volatile storage
1551	  directly addressable by the CPU, such as NOR flash. This saves RAM
1552	  space since the text section of the kernel is not loaded from flash
1553	  to RAM.  Read-write sections, such as the data section and stack,
1554	  are still copied to RAM.  The XIP kernel is not compressed since
1555	  it has to run directly from flash, so it will take more space to
1556	  store it.  The flash address used to link the kernel object files,
1557	  and for storing it, is configuration dependent. Therefore, if you
1558	  say Y here, you must know the proper physical address where to
1559	  store the kernel image depending on your own flash memory usage.
1560
1561	  Also note that the make target becomes "make xipImage" rather than
1562	  "make zImage" or "make Image".  The final kernel binary to put in
1563	  ROM memory will be arch/arm/boot/xipImage.
1564
1565	  If unsure, say N.
1566
1567config XIP_PHYS_ADDR
1568	hex "XIP Kernel Physical Location"
1569	depends on XIP_KERNEL
1570	default "0x00080000"
1571	help
1572	  This is the physical address in your flash memory the kernel will
1573	  be linked for and stored to.  This address is dependent on your
1574	  own flash usage.
1575
1576config XIP_DEFLATED_DATA
1577	bool "Store kernel .data section compressed in ROM"
1578	depends on XIP_KERNEL
1579	select ZLIB_INFLATE
1580	help
1581	  Before the kernel is actually executed, its .data section has to be
1582	  copied to RAM from ROM. This option allows for storing that data
1583	  in compressed form and decompressed to RAM rather than merely being
1584	  copied, saving some precious ROM space. A possible drawback is a
1585	  slightly longer boot delay.
1586
1587config ARCH_SUPPORTS_KEXEC
1588	def_bool (!SMP || PM_SLEEP_SMP) && MMU
 
 
 
 
 
 
 
 
 
 
 
 
1589
1590config ATAGS_PROC
1591	bool "Export atags in procfs"
1592	depends on ATAGS && KEXEC
1593	default y
1594	help
1595	  Should the atags used to boot the kernel be exported in an "atags"
1596	  file in procfs. Useful with kexec.
1597
1598config ARCH_SUPPORTS_CRASH_DUMP
1599	def_bool y
 
 
 
 
 
 
 
1600
1601config ARCH_DEFAULT_CRASH_DUMP
1602	def_bool y
1603
1604config AUTO_ZRELADDR
1605	bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM
1606	default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100)
1607	help
1608	  ZRELADDR is the physical address where the decompressed kernel
1609	  image will be placed. If AUTO_ZRELADDR is selected, the address
1610	  will be determined at run-time, either by masking the current IP
1611	  with 0xf8000000, or, if invalid, from the DTB passed in r2.
1612	  This assumes the zImage being placed in the first 128MB from
1613	  start of memory.
1614
1615config EFI_STUB
1616	bool
1617
1618config EFI
1619	bool "UEFI runtime support"
1620	depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1621	select UCS2_STRING
1622	select EFI_PARAMS_FROM_FDT
1623	select EFI_STUB
1624	select EFI_GENERIC_STUB
1625	select EFI_RUNTIME_WRAPPERS
1626	help
1627	  This option provides support for runtime services provided
1628	  by UEFI firmware (such as non-volatile variables, realtime
1629	  clock, and platform reset). A UEFI stub is also provided to
1630	  allow the kernel to be booted as an EFI application. This
1631	  is only useful for kernels that may run on systems that have
1632	  UEFI firmware.
1633
1634config DMI
1635	bool "Enable support for SMBIOS (DMI) tables"
1636	depends on EFI
1637	default y
1638	help
1639	  This enables SMBIOS/DMI feature for systems.
1640
1641	  This option is only useful on systems that have UEFI firmware.
1642	  However, even with this option, the resultant kernel should
1643	  continue to boot on existing non-UEFI platforms.
1644
1645	  NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1646	  i.e., the the practice of identifying the platform via DMI to
1647	  decide whether certain workarounds for buggy hardware and/or
1648	  firmware need to be enabled. This would require the DMI subsystem
1649	  to be enabled much earlier than we do on ARM, which is non-trivial.
1650
1651endmenu
1652
1653menu "CPU Power Management"
1654
1655source "drivers/cpufreq/Kconfig"
1656
1657source "drivers/cpuidle/Kconfig"
1658
1659endmenu
1660
1661menu "Floating point emulation"
1662
1663comment "At least one emulation must be selected"
1664
1665config FPE_NWFPE
1666	bool "NWFPE math emulation"
1667	depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1668	help
1669	  Say Y to include the NWFPE floating point emulator in the kernel.
1670	  This is necessary to run most binaries. Linux does not currently
1671	  support floating point hardware so you need to say Y here even if
1672	  your machine has an FPA or floating point co-processor podule.
1673
1674	  You may say N here if you are going to load the Acorn FPEmulator
1675	  early in the bootup.
1676
1677config FPE_NWFPE_XP
1678	bool "Support extended precision"
1679	depends on FPE_NWFPE
1680	help
1681	  Say Y to include 80-bit support in the kernel floating-point
1682	  emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1683	  Note that gcc does not generate 80-bit operations by default,
1684	  so in most cases this option only enlarges the size of the
1685	  floating point emulator without any good reason.
1686
1687	  You almost surely want to say N here.
1688
1689config FPE_FASTFPE
1690	bool "FastFPE math emulation (EXPERIMENTAL)"
1691	depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1692	help
1693	  Say Y here to include the FAST floating point emulator in the kernel.
1694	  This is an experimental much faster emulator which now also has full
1695	  precision for the mantissa.  It does not support any exceptions.
1696	  It is very simple, and approximately 3-6 times faster than NWFPE.
1697
1698	  It should be sufficient for most programs.  It may be not suitable
1699	  for scientific calculations, but you have to check this for yourself.
1700	  If you do not feel you need a faster FP emulation you should better
1701	  choose NWFPE.
1702
1703config VFP
1704	bool "VFP-format floating point maths"
1705	depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1706	help
1707	  Say Y to include VFP support code in the kernel. This is needed
1708	  if your hardware includes a VFP unit.
1709
1710	  Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for
1711	  release notes and additional status information.
1712
1713	  Say N if your target does not have VFP hardware.
1714
1715config VFPv3
1716	bool
1717	depends on VFP
1718	default y if CPU_V7
1719
1720config NEON
1721	bool "Advanced SIMD (NEON) Extension support"
1722	depends on VFPv3 && CPU_V7
1723	help
1724	  Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1725	  Extension.
1726
1727config KERNEL_MODE_NEON
1728	bool "Support for NEON in kernel mode"
1729	depends on NEON && AEABI
1730	help
1731	  Say Y to include support for NEON in kernel mode.
1732
1733endmenu
1734
1735menu "Power management options"
1736
1737source "kernel/power/Kconfig"
1738
1739config ARCH_SUSPEND_POSSIBLE
1740	depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1741		CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1742	def_bool y
1743
1744config ARM_CPU_SUSPEND
1745	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1746	depends on ARCH_SUSPEND_POSSIBLE
1747
1748config ARCH_HIBERNATION_POSSIBLE
1749	bool
1750	depends on MMU
1751	default y if ARCH_SUSPEND_POSSIBLE
1752
1753endmenu
 
 
 
 
 
 
1754
1755source "arch/arm/Kconfig.assembler"