1config ARM64 2 def_bool y 3 select ACPI_CCA_REQUIRED if ACPI 4 select ACPI_GENERIC_GSI if ACPI 5 select ACPI_GTDT if ACPI 6 select ACPI_IORT if ACPI 7 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 8 select ACPI_MCFG if ACPI 9 select ACPI_SPCR_TABLE if ACPI 10 select ARCH_CLOCKSOURCE_DATA 11 select ARCH_HAS_DEBUG_VIRTUAL 12 select ARCH_HAS_DEVMEM_IS_ALLOWED 13 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 14 select ARCH_HAS_ELF_RANDOMIZE 15 select ARCH_HAS_FORTIFY_SOURCE 16 select ARCH_HAS_GCOV_PROFILE_ALL 17 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 18 select ARCH_HAS_KCOV 19 select ARCH_HAS_MEMBARRIER_SYNC_CORE 20 select ARCH_HAS_SET_MEMORY 21 select ARCH_HAS_SG_CHAIN 22 select ARCH_HAS_STRICT_KERNEL_RWX 23 select ARCH_HAS_STRICT_MODULE_RWX 24 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 25 select ARCH_HAVE_NMI_SAFE_CMPXCHG 26 select ARCH_INLINE_READ_LOCK if !PREEMPT 27 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT 28 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT 29 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT 30 select ARCH_INLINE_READ_UNLOCK if !PREEMPT 31 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT 32 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT 33 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT 34 select ARCH_INLINE_WRITE_LOCK if !PREEMPT 35 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT 36 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT 37 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT 38 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT 39 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT 40 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT 41 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT 42 select ARCH_USE_CMPXCHG_LOCKREF 43 select ARCH_USE_QUEUED_RWLOCKS 44 select ARCH_SUPPORTS_MEMORY_FAILURE 45 select ARCH_SUPPORTS_ATOMIC_RMW 46 select ARCH_SUPPORTS_NUMA_BALANCING 47 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 48 select ARCH_WANT_FRAME_POINTERS 49 select ARCH_HAS_UBSAN_SANITIZE_ALL 50 select ARM_AMBA 51 select ARM_ARCH_TIMER 52 select ARM_GIC 53 select AUDIT_ARCH_COMPAT_GENERIC 54 select ARM_GIC_V2M if PCI 55 select ARM_GIC_V3 56 select ARM_GIC_V3_ITS if PCI 57 select ARM_PSCI_FW 58 select BUILDTIME_EXTABLE_SORT 59 select CLONE_BACKWARDS 60 select COMMON_CLK 61 select CPU_PM if (SUSPEND || CPU_IDLE) 62 select DCACHE_WORD_ACCESS 63 select DMA_DIRECT_OPS 64 select EDAC_SUPPORT 65 select FRAME_POINTER 66 select GENERIC_ALLOCATOR 67 select GENERIC_ARCH_TOPOLOGY 68 select GENERIC_CLOCKEVENTS 69 select GENERIC_CLOCKEVENTS_BROADCAST 70 select GENERIC_CPU_AUTOPROBE 71 select GENERIC_EARLY_IOREMAP 72 select GENERIC_IDLE_POLL_SETUP 73 select GENERIC_IRQ_PROBE 74 select GENERIC_IRQ_SHOW 75 select GENERIC_IRQ_SHOW_LEVEL 76 select GENERIC_PCI_IOMAP 77 select GENERIC_SCHED_CLOCK 78 select GENERIC_SMP_IDLE_THREAD 79 select GENERIC_STRNCPY_FROM_USER 80 select GENERIC_STRNLEN_USER 81 select GENERIC_TIME_VSYSCALL 82 select HANDLE_DOMAIN_IRQ 83 select HARDIRQS_SW_RESEND 84 select HAVE_ACPI_APEI if (ACPI && EFI) 85 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 86 select HAVE_ARCH_AUDITSYSCALL 87 select HAVE_ARCH_BITREVERSE 88 select HAVE_ARCH_HUGE_VMAP 89 select HAVE_ARCH_JUMP_LABEL 90 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 91 select HAVE_ARCH_KGDB 92 select HAVE_ARCH_MMAP_RND_BITS 93 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 94 select HAVE_ARCH_SECCOMP_FILTER 95 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 96 select HAVE_ARCH_TRACEHOOK 97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 98 select HAVE_ARCH_VMAP_STACK 99 select HAVE_ARM_SMCCC 100 select HAVE_EBPF_JIT 101 select HAVE_C_RECORDMCOUNT 102 select HAVE_CC_STACKPROTECTOR 103 select HAVE_CMPXCHG_DOUBLE 104 select HAVE_CMPXCHG_LOCAL 105 select HAVE_CONTEXT_TRACKING 106 select HAVE_DEBUG_BUGVERBOSE 107 select HAVE_DEBUG_KMEMLEAK 108 select HAVE_DMA_API_DEBUG 109 select HAVE_DMA_CONTIGUOUS 110 select HAVE_DYNAMIC_FTRACE 111 select HAVE_EFFICIENT_UNALIGNED_ACCESS 112 select HAVE_FTRACE_MCOUNT_RECORD 113 select HAVE_FUNCTION_TRACER 114 select HAVE_FUNCTION_GRAPH_TRACER 115 select HAVE_GCC_PLUGINS 116 select HAVE_GENERIC_DMA_COHERENT 117 select HAVE_HW_BREAKPOINT if PERF_EVENTS 118 select HAVE_IRQ_TIME_ACCOUNTING 119 select HAVE_MEMBLOCK 120 select HAVE_MEMBLOCK_NODE_MAP if NUMA 121 select HAVE_NMI 122 select HAVE_PATA_PLATFORM 123 select HAVE_PERF_EVENTS 124 select HAVE_PERF_REGS 125 select HAVE_PERF_USER_STACK_DUMP 126 select HAVE_REGS_AND_STACK_ACCESS_API 127 select HAVE_RCU_TABLE_FREE 128 select HAVE_SYSCALL_TRACEPOINTS 129 select HAVE_KPROBES 130 select HAVE_KRETPROBES 131 select IOMMU_DMA if IOMMU_SUPPORT 132 select IRQ_DOMAIN 133 select IRQ_FORCED_THREADING 134 select MODULES_USE_ELF_RELA 135 select MULTI_IRQ_HANDLER 136 select NO_BOOTMEM 137 select OF 138 select OF_EARLY_FLATTREE 139 select OF_RESERVED_MEM 140 select PCI_ECAM if ACPI 141 select POWER_RESET 142 select POWER_SUPPLY 143 select REFCOUNT_FULL 144 select SPARSE_IRQ 145 select SYSCTL_EXCEPTION_TRACE 146 select THREAD_INFO_IN_TASK 147 help 148 ARM 64-bit (AArch64) Linux support. 149 150config 64BIT 151 def_bool y 152 153config ARCH_PHYS_ADDR_T_64BIT 154 def_bool y 155 156config MMU 157 def_bool y 158 159config ARM64_PAGE_SHIFT 160 int 161 default 16 if ARM64_64K_PAGES 162 default 14 if ARM64_16K_PAGES 163 default 12 164 165config ARM64_CONT_SHIFT 166 int 167 default 5 if ARM64_64K_PAGES 168 default 7 if ARM64_16K_PAGES 169 default 4 170 171config ARCH_MMAP_RND_BITS_MIN 172 default 14 if ARM64_64K_PAGES 173 default 16 if ARM64_16K_PAGES 174 default 18 175 176# max bits determined by the following formula: 177# VA_BITS - PAGE_SHIFT - 3 178config ARCH_MMAP_RND_BITS_MAX 179 default 19 if ARM64_VA_BITS=36 180 default 24 if ARM64_VA_BITS=39 181 default 27 if ARM64_VA_BITS=42 182 default 30 if ARM64_VA_BITS=47 183 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 184 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 185 default 33 if ARM64_VA_BITS=48 186 default 14 if ARM64_64K_PAGES 187 default 16 if ARM64_16K_PAGES 188 default 18 189 190config ARCH_MMAP_RND_COMPAT_BITS_MIN 191 default 7 if ARM64_64K_PAGES 192 default 9 if ARM64_16K_PAGES 193 default 11 194 195config ARCH_MMAP_RND_COMPAT_BITS_MAX 196 default 16 197 198config NO_IOPORT_MAP 199 def_bool y if !PCI 200 201config STACKTRACE_SUPPORT 202 def_bool y 203 204config ILLEGAL_POINTER_VALUE 205 hex 206 default 0xdead000000000000 207 208config LOCKDEP_SUPPORT 209 def_bool y 210 211config TRACE_IRQFLAGS_SUPPORT 212 def_bool y 213 214config RWSEM_XCHGADD_ALGORITHM 215 def_bool y 216 217config GENERIC_BUG 218 def_bool y 219 depends on BUG 220 221config GENERIC_BUG_RELATIVE_POINTERS 222 def_bool y 223 depends on GENERIC_BUG 224 225config GENERIC_HWEIGHT 226 def_bool y 227 228config GENERIC_CSUM 229 def_bool y 230 231config GENERIC_CALIBRATE_DELAY 232 def_bool y 233 234config ZONE_DMA32 235 def_bool y 236 237config HAVE_GENERIC_GUP 238 def_bool y 239 240config ARCH_DMA_ADDR_T_64BIT 241 def_bool y 242 243config NEED_DMA_MAP_STATE 244 def_bool y 245 246config NEED_SG_DMA_LENGTH 247 def_bool y 248 249config SMP 250 def_bool y 251 252config SWIOTLB 253 def_bool y 254 255config IOMMU_HELPER 256 def_bool SWIOTLB 257 258config KERNEL_MODE_NEON 259 def_bool y 260 261config FIX_EARLYCON_MEM 262 def_bool y 263 264config PGTABLE_LEVELS 265 int 266 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 267 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 268 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 269 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 270 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 271 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 272 273config ARCH_SUPPORTS_UPROBES 274 def_bool y 275 276config ARCH_PROC_KCORE_TEXT 277 def_bool y 278 279config MULTI_IRQ_HANDLER 280 def_bool y 281 282source "init/Kconfig" 283 284source "kernel/Kconfig.freezer" 285 286source "arch/arm64/Kconfig.platforms" 287 288menu "Bus support" 289 290config PCI 291 bool "PCI support" 292 help 293 This feature enables support for PCI bus system. If you say Y 294 here, the kernel will include drivers and infrastructure code 295 to support PCI bus devices. 296 297config PCI_DOMAINS 298 def_bool PCI 299 300config PCI_DOMAINS_GENERIC 301 def_bool PCI 302 303config PCI_SYSCALL 304 def_bool PCI 305 306source "drivers/pci/Kconfig" 307 308endmenu 309 310menu "Kernel Features" 311 312menu "ARM errata workarounds via the alternatives framework" 313 314config ARM64_ERRATUM_826319 315 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 316 default y 317 help 318 This option adds an alternative code sequence to work around ARM 319 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 320 AXI master interface and an L2 cache. 321 322 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 323 and is unable to accept a certain write via this interface, it will 324 not progress on read data presented on the read data channel and the 325 system can deadlock. 326 327 The workaround promotes data cache clean instructions to 328 data cache clean-and-invalidate. 329 Please note that this does not necessarily enable the workaround, 330 as it depends on the alternative framework, which will only patch 331 the kernel if an affected CPU is detected. 332 333 If unsure, say Y. 334 335config ARM64_ERRATUM_827319 336 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 337 default y 338 help 339 This option adds an alternative code sequence to work around ARM 340 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 341 master interface and an L2 cache. 342 343 Under certain conditions this erratum can cause a clean line eviction 344 to occur at the same time as another transaction to the same address 345 on the AMBA 5 CHI interface, which can cause data corruption if the 346 interconnect reorders the two transactions. 347 348 The workaround promotes data cache clean instructions to 349 data cache clean-and-invalidate. 350 Please note that this does not necessarily enable the workaround, 351 as it depends on the alternative framework, which will only patch 352 the kernel if an affected CPU is detected. 353 354 If unsure, say Y. 355 356config ARM64_ERRATUM_824069 357 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 358 default y 359 help 360 This option adds an alternative code sequence to work around ARM 361 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 362 to a coherent interconnect. 363 364 If a Cortex-A53 processor is executing a store or prefetch for 365 write instruction at the same time as a processor in another 366 cluster is executing a cache maintenance operation to the same 367 address, then this erratum might cause a clean cache line to be 368 incorrectly marked as dirty. 369 370 The workaround promotes data cache clean instructions to 371 data cache clean-and-invalidate. 372 Please note that this option does not necessarily enable the 373 workaround, as it depends on the alternative framework, which will 374 only patch the kernel if an affected CPU is detected. 375 376 If unsure, say Y. 377 378config ARM64_ERRATUM_819472 379 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 380 default y 381 help 382 This option adds an alternative code sequence to work around ARM 383 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 384 present when it is connected to a coherent interconnect. 385 386 If the processor is executing a load and store exclusive sequence at 387 the same time as a processor in another cluster is executing a cache 388 maintenance operation to the same address, then this erratum might 389 cause data corruption. 390 391 The workaround promotes data cache clean instructions to 392 data cache clean-and-invalidate. 393 Please note that this does not necessarily enable the workaround, 394 as it depends on the alternative framework, which will only patch 395 the kernel if an affected CPU is detected. 396 397 If unsure, say Y. 398 399config ARM64_ERRATUM_832075 400 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 401 default y 402 help 403 This option adds an alternative code sequence to work around ARM 404 erratum 832075 on Cortex-A57 parts up to r1p2. 405 406 Affected Cortex-A57 parts might deadlock when exclusive load/store 407 instructions to Write-Back memory are mixed with Device loads. 408 409 The workaround is to promote device loads to use Load-Acquire 410 semantics. 411 Please note that this does not necessarily enable the workaround, 412 as it depends on the alternative framework, which will only patch 413 the kernel if an affected CPU is detected. 414 415 If unsure, say Y. 416 417config ARM64_ERRATUM_834220 418 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 419 depends on KVM 420 default y 421 help 422 This option adds an alternative code sequence to work around ARM 423 erratum 834220 on Cortex-A57 parts up to r1p2. 424 425 Affected Cortex-A57 parts might report a Stage 2 translation 426 fault as the result of a Stage 1 fault for load crossing a 427 page boundary when there is a permission or device memory 428 alignment fault at Stage 1 and a translation fault at Stage 2. 429 430 The workaround is to verify that the Stage 1 translation 431 doesn't generate a fault before handling the Stage 2 fault. 432 Please note that this does not necessarily enable the workaround, 433 as it depends on the alternative framework, which will only patch 434 the kernel if an affected CPU is detected. 435 436 If unsure, say Y. 437 438config ARM64_ERRATUM_845719 439 bool "Cortex-A53: 845719: a load might read incorrect data" 440 depends on COMPAT 441 default y 442 help 443 This option adds an alternative code sequence to work around ARM 444 erratum 845719 on Cortex-A53 parts up to r0p4. 445 446 When running a compat (AArch32) userspace on an affected Cortex-A53 447 part, a load at EL0 from a virtual address that matches the bottom 32 448 bits of the virtual address used by a recent load at (AArch64) EL1 449 might return incorrect data. 450 451 The workaround is to write the contextidr_el1 register on exception 452 return to a 32-bit task. 453 Please note that this does not necessarily enable the workaround, 454 as it depends on the alternative framework, which will only patch 455 the kernel if an affected CPU is detected. 456 457 If unsure, say Y. 458 459config ARM64_ERRATUM_843419 460 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 461 default y 462 select ARM64_MODULE_PLTS if MODULES 463 help 464 This option links the kernel with '--fix-cortex-a53-843419' and 465 enables PLT support to replace certain ADRP instructions, which can 466 cause subsequent memory accesses to use an incorrect address on 467 Cortex-A53 parts up to r0p4. 468 469 If unsure, say Y. 470 471config ARM64_ERRATUM_1024718 472 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 473 default y 474 help 475 This option adds work around for Arm Cortex-A55 Erratum 1024718. 476 477 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 478 update of the hardware dirty bit when the DBM/AP bits are updated 479 without a break-before-make. The work around is to disable the usage 480 of hardware DBM locally on the affected cores. CPUs not affected by 481 erratum will continue to use the feature. 482 483 If unsure, say Y. 484 485config CAVIUM_ERRATUM_22375 486 bool "Cavium erratum 22375, 24313" 487 default y 488 help 489 Enable workaround for erratum 22375, 24313. 490 491 This implements two gicv3-its errata workarounds for ThunderX. Both 492 with small impact affecting only ITS table allocation. 493 494 erratum 22375: only alloc 8MB table size 495 erratum 24313: ignore memory access type 496 497 The fixes are in ITS initialization and basically ignore memory access 498 type and table size provided by the TYPER and BASER registers. 499 500 If unsure, say Y. 501 502config CAVIUM_ERRATUM_23144 503 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 504 depends on NUMA 505 default y 506 help 507 ITS SYNC command hang for cross node io and collections/cpu mapping. 508 509 If unsure, say Y. 510 511config CAVIUM_ERRATUM_23154 512 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 513 default y 514 help 515 The gicv3 of ThunderX requires a modified version for 516 reading the IAR status to ensure data synchronization 517 (access to icc_iar1_el1 is not sync'ed before and after). 518 519 If unsure, say Y. 520 521config CAVIUM_ERRATUM_27456 522 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 523 default y 524 help 525 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 526 instructions may cause the icache to become corrupted if it 527 contains data for a non-current ASID. The fix is to 528 invalidate the icache when changing the mm context. 529 530 If unsure, say Y. 531 532config CAVIUM_ERRATUM_30115 533 bool "Cavium erratum 30115: Guest may disable interrupts in host" 534 default y 535 help 536 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 537 1.2, and T83 Pass 1.0, KVM guest execution may disable 538 interrupts in host. Trapping both GICv3 group-0 and group-1 539 accesses sidesteps the issue. 540 541 If unsure, say Y. 542 543config QCOM_FALKOR_ERRATUM_1003 544 bool "Falkor E1003: Incorrect translation due to ASID change" 545 default y 546 help 547 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 548 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 549 in TTBR1_EL1, this situation only occurs in the entry trampoline and 550 then only for entries in the walk cache, since the leaf translation 551 is unchanged. Work around the erratum by invalidating the walk cache 552 entries for the trampoline before entering the kernel proper. 553 554config QCOM_FALKOR_ERRATUM_1009 555 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 556 default y 557 help 558 On Falkor v1, the CPU may prematurely complete a DSB following a 559 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 560 one more time to fix the issue. 561 562 If unsure, say Y. 563 564config QCOM_QDF2400_ERRATUM_0065 565 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 566 default y 567 help 568 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 569 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 570 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 571 572 If unsure, say Y. 573 574config SOCIONEXT_SYNQUACER_PREITS 575 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 576 default y 577 help 578 Socionext Synquacer SoCs implement a separate h/w block to generate 579 MSI doorbell writes with non-zero values for the device ID. 580 581 If unsure, say Y. 582 583config HISILICON_ERRATUM_161600802 584 bool "Hip07 161600802: Erroneous redistributor VLPI base" 585 default y 586 help 587 The HiSilicon Hip07 SoC usees the wrong redistributor base 588 when issued ITS commands such as VMOVP and VMAPP, and requires 589 a 128kB offset to be applied to the target address in this commands. 590 591 If unsure, say Y. 592 593config QCOM_FALKOR_ERRATUM_E1041 594 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 595 default y 596 help 597 Falkor CPU may speculatively fetch instructions from an improper 598 memory location when MMU translation is changed from SCTLR_ELn[M]=1 599 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 600 601 If unsure, say Y. 602 603endmenu 604 605 606choice 607 prompt "Page size" 608 default ARM64_4K_PAGES 609 help 610 Page size (translation granule) configuration. 611 612config ARM64_4K_PAGES 613 bool "4KB" 614 help 615 This feature enables 4KB pages support. 616 617config ARM64_16K_PAGES 618 bool "16KB" 619 help 620 The system will use 16KB pages support. AArch32 emulation 621 requires applications compiled with 16K (or a multiple of 16K) 622 aligned segments. 623 624config ARM64_64K_PAGES 625 bool "64KB" 626 help 627 This feature enables 64KB pages support (4KB by default) 628 allowing only two levels of page tables and faster TLB 629 look-up. AArch32 emulation requires applications compiled 630 with 64K aligned segments. 631 632endchoice 633 634choice 635 prompt "Virtual address space size" 636 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 637 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 638 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 639 help 640 Allows choosing one of multiple possible virtual address 641 space sizes. The level of translation table is determined by 642 a combination of page size and virtual address space size. 643 644config ARM64_VA_BITS_36 645 bool "36-bit" if EXPERT 646 depends on ARM64_16K_PAGES 647 648config ARM64_VA_BITS_39 649 bool "39-bit" 650 depends on ARM64_4K_PAGES 651 652config ARM64_VA_BITS_42 653 bool "42-bit" 654 depends on ARM64_64K_PAGES 655 656config ARM64_VA_BITS_47 657 bool "47-bit" 658 depends on ARM64_16K_PAGES 659 660config ARM64_VA_BITS_48 661 bool "48-bit" 662 663endchoice 664 665config ARM64_VA_BITS 666 int 667 default 36 if ARM64_VA_BITS_36 668 default 39 if ARM64_VA_BITS_39 669 default 42 if ARM64_VA_BITS_42 670 default 47 if ARM64_VA_BITS_47 671 default 48 if ARM64_VA_BITS_48 672 673choice 674 prompt "Physical address space size" 675 default ARM64_PA_BITS_48 676 help 677 Choose the maximum physical address range that the kernel will 678 support. 679 680config ARM64_PA_BITS_48 681 bool "48-bit" 682 683config ARM64_PA_BITS_52 684 bool "52-bit (ARMv8.2)" 685 depends on ARM64_64K_PAGES 686 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 687 help 688 Enable support for a 52-bit physical address space, introduced as 689 part of the ARMv8.2-LPA extension. 690 691 With this enabled, the kernel will also continue to work on CPUs that 692 do not support ARMv8.2-LPA, but with some added memory overhead (and 693 minor performance overhead). 694 695endchoice 696 697config ARM64_PA_BITS 698 int 699 default 48 if ARM64_PA_BITS_48 700 default 52 if ARM64_PA_BITS_52 701 702config CPU_BIG_ENDIAN 703 bool "Build big-endian kernel" 704 help 705 Say Y if you plan on running a kernel in big-endian mode. 706 707config SCHED_MC 708 bool "Multi-core scheduler support" 709 help 710 Multi-core scheduler support improves the CPU scheduler's decision 711 making when dealing with multi-core CPU chips at a cost of slightly 712 increased overhead in some places. If unsure say N here. 713 714config SCHED_SMT 715 bool "SMT scheduler support" 716 help 717 Improves the CPU scheduler's decision making when dealing with 718 MultiThreading at a cost of slightly increased overhead in some 719 places. If unsure say N here. 720 721config NR_CPUS 722 int "Maximum number of CPUs (2-4096)" 723 range 2 4096 724 # These have to remain sorted largest to smallest 725 default "64" 726 727config HOTPLUG_CPU 728 bool "Support for hot-pluggable CPUs" 729 select GENERIC_IRQ_MIGRATION 730 help 731 Say Y here to experiment with turning CPUs off and on. CPUs 732 can be controlled through /sys/devices/system/cpu. 733 734# Common NUMA Features 735config NUMA 736 bool "Numa Memory Allocation and Scheduler Support" 737 select ACPI_NUMA if ACPI 738 select OF_NUMA 739 help 740 Enable NUMA (Non Uniform Memory Access) support. 741 742 The kernel will try to allocate memory used by a CPU on the 743 local memory of the CPU and add some more 744 NUMA awareness to the kernel. 745 746config NODES_SHIFT 747 int "Maximum NUMA Nodes (as a power of 2)" 748 range 1 10 749 default "2" 750 depends on NEED_MULTIPLE_NODES 751 help 752 Specify the maximum number of NUMA Nodes available on the target 753 system. Increases memory reserved to accommodate various tables. 754 755config USE_PERCPU_NUMA_NODE_ID 756 def_bool y 757 depends on NUMA 758 759config HAVE_SETUP_PER_CPU_AREA 760 def_bool y 761 depends on NUMA 762 763config NEED_PER_CPU_EMBED_FIRST_CHUNK 764 def_bool y 765 depends on NUMA 766 767config HOLES_IN_ZONE 768 def_bool y 769 depends on NUMA 770 771source kernel/Kconfig.preempt 772source kernel/Kconfig.hz 773 774config ARCH_SUPPORTS_DEBUG_PAGEALLOC 775 def_bool y 776 777config ARCH_HAS_HOLES_MEMORYMODEL 778 def_bool y if SPARSEMEM 779 780config ARCH_SPARSEMEM_ENABLE 781 def_bool y 782 select SPARSEMEM_VMEMMAP_ENABLE 783 784config ARCH_SPARSEMEM_DEFAULT 785 def_bool ARCH_SPARSEMEM_ENABLE 786 787config ARCH_SELECT_MEMORY_MODEL 788 def_bool ARCH_SPARSEMEM_ENABLE 789 790config HAVE_ARCH_PFN_VALID 791 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM 792 793config HW_PERF_EVENTS 794 def_bool y 795 depends on ARM_PMU 796 797config SYS_SUPPORTS_HUGETLBFS 798 def_bool y 799 800config ARCH_WANT_HUGE_PMD_SHARE 801 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 802 803config ARCH_HAS_CACHE_LINE_SIZE 804 def_bool y 805 806source "mm/Kconfig" 807 808config SECCOMP 809 bool "Enable seccomp to safely compute untrusted bytecode" 810 ---help--- 811 This kernel feature is useful for number crunching applications 812 that may need to compute untrusted bytecode during their 813 execution. By using pipes or other transports made available to 814 the process as file descriptors supporting the read/write 815 syscalls, it's possible to isolate those applications in 816 their own address space using seccomp. Once seccomp is 817 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 818 and the task is only allowed to execute a few safe syscalls 819 defined by each seccomp mode. 820 821config PARAVIRT 822 bool "Enable paravirtualization code" 823 help 824 This changes the kernel so it can modify itself when it is run 825 under a hypervisor, potentially improving performance significantly 826 over full virtualization. 827 828config PARAVIRT_TIME_ACCOUNTING 829 bool "Paravirtual steal time accounting" 830 select PARAVIRT 831 default n 832 help 833 Select this option to enable fine granularity task steal time 834 accounting. Time spent executing other tasks in parallel with 835 the current vCPU is discounted from the vCPU power. To account for 836 that, there can be a small performance impact. 837 838 If in doubt, say N here. 839 840config KEXEC 841 depends on PM_SLEEP_SMP 842 select KEXEC_CORE 843 bool "kexec system call" 844 ---help--- 845 kexec is a system call that implements the ability to shutdown your 846 current kernel, and to start another kernel. It is like a reboot 847 but it is independent of the system firmware. And like a reboot 848 you can start any kernel with it, not just Linux. 849 850config CRASH_DUMP 851 bool "Build kdump crash kernel" 852 help 853 Generate crash dump after being started by kexec. This should 854 be normally only set in special crash dump kernels which are 855 loaded in the main kernel with kexec-tools into a specially 856 reserved region and then later executed after a crash by 857 kdump/kexec. 858 859 For more details see Documentation/kdump/kdump.txt 860 861config XEN_DOM0 862 def_bool y 863 depends on XEN 864 865config XEN 866 bool "Xen guest support on ARM64" 867 depends on ARM64 && OF 868 select SWIOTLB_XEN 869 select PARAVIRT 870 help 871 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 872 873config FORCE_MAX_ZONEORDER 874 int 875 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 876 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 877 default "11" 878 help 879 The kernel memory allocator divides physically contiguous memory 880 blocks into "zones", where each zone is a power of two number of 881 pages. This option selects the largest power of two that the kernel 882 keeps in the memory allocator. If you need to allocate very large 883 blocks of physically contiguous memory, then you may need to 884 increase this value. 885 886 This config option is actually maximum order plus one. For example, 887 a value of 11 means that the largest free memory block is 2^10 pages. 888 889 We make sure that we can allocate upto a HugePage size for each configuration. 890 Hence we have : 891 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 892 893 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 894 4M allocations matching the default size used by generic code. 895 896config UNMAP_KERNEL_AT_EL0 897 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 898 default y 899 help 900 Speculation attacks against some high-performance processors can 901 be used to bypass MMU permission checks and leak kernel data to 902 userspace. This can be defended against by unmapping the kernel 903 when running in userspace, mapping it back in on exception entry 904 via a trampoline page in the vector table. 905 906 If unsure, say Y. 907 908config HARDEN_BRANCH_PREDICTOR 909 bool "Harden the branch predictor against aliasing attacks" if EXPERT 910 default y 911 help 912 Speculation attacks against some high-performance processors rely on 913 being able to manipulate the branch predictor for a victim context by 914 executing aliasing branches in the attacker context. Such attacks 915 can be partially mitigated against by clearing internal branch 916 predictor state and limiting the prediction logic in some situations. 917 918 This config option will take CPU-specific actions to harden the 919 branch predictor against aliasing attacks and may rely on specific 920 instruction sequences or control bits being set by the system 921 firmware. 922 923 If unsure, say Y. 924 925menuconfig ARMV8_DEPRECATED 926 bool "Emulate deprecated/obsolete ARMv8 instructions" 927 depends on COMPAT 928 depends on SYSCTL 929 help 930 Legacy software support may require certain instructions 931 that have been deprecated or obsoleted in the architecture. 932 933 Enable this config to enable selective emulation of these 934 features. 935 936 If unsure, say Y 937 938if ARMV8_DEPRECATED 939 940config SWP_EMULATION 941 bool "Emulate SWP/SWPB instructions" 942 help 943 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 944 they are always undefined. Say Y here to enable software 945 emulation of these instructions for userspace using LDXR/STXR. 946 947 In some older versions of glibc [<=2.8] SWP is used during futex 948 trylock() operations with the assumption that the code will not 949 be preempted. This invalid assumption may be more likely to fail 950 with SWP emulation enabled, leading to deadlock of the user 951 application. 952 953 NOTE: when accessing uncached shared regions, LDXR/STXR rely 954 on an external transaction monitoring block called a global 955 monitor to maintain update atomicity. If your system does not 956 implement a global monitor, this option can cause programs that 957 perform SWP operations to uncached memory to deadlock. 958 959 If unsure, say Y 960 961config CP15_BARRIER_EMULATION 962 bool "Emulate CP15 Barrier instructions" 963 help 964 The CP15 barrier instructions - CP15ISB, CP15DSB, and 965 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 966 strongly recommended to use the ISB, DSB, and DMB 967 instructions instead. 968 969 Say Y here to enable software emulation of these 970 instructions for AArch32 userspace code. When this option is 971 enabled, CP15 barrier usage is traced which can help 972 identify software that needs updating. 973 974 If unsure, say Y 975 976config SETEND_EMULATION 977 bool "Emulate SETEND instruction" 978 help 979 The SETEND instruction alters the data-endianness of the 980 AArch32 EL0, and is deprecated in ARMv8. 981 982 Say Y here to enable software emulation of the instruction 983 for AArch32 userspace code. 984 985 Note: All the cpus on the system must have mixed endian support at EL0 986 for this feature to be enabled. If a new CPU - which doesn't support mixed 987 endian - is hotplugged in after this feature has been enabled, there could 988 be unexpected results in the applications. 989 990 If unsure, say Y 991endif 992 993config ARM64_SW_TTBR0_PAN 994 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 995 help 996 Enabling this option prevents the kernel from accessing 997 user-space memory directly by pointing TTBR0_EL1 to a reserved 998 zeroed area and reserved ASID. The user access routines 999 restore the valid TTBR0_EL1 temporarily. 1000 1001menu "ARMv8.1 architectural features" 1002 1003config ARM64_HW_AFDBM 1004 bool "Support for hardware updates of the Access and Dirty page flags" 1005 default y 1006 help 1007 The ARMv8.1 architecture extensions introduce support for 1008 hardware updates of the access and dirty information in page 1009 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1010 capable processors, accesses to pages with PTE_AF cleared will 1011 set this bit instead of raising an access flag fault. 1012 Similarly, writes to read-only pages with the DBM bit set will 1013 clear the read-only bit (AP[2]) instead of raising a 1014 permission fault. 1015 1016 Kernels built with this configuration option enabled continue 1017 to work on pre-ARMv8.1 hardware and the performance impact is 1018 minimal. If unsure, say Y. 1019 1020config ARM64_PAN 1021 bool "Enable support for Privileged Access Never (PAN)" 1022 default y 1023 help 1024 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1025 prevents the kernel or hypervisor from accessing user-space (EL0) 1026 memory directly. 1027 1028 Choosing this option will cause any unprotected (not using 1029 copy_to_user et al) memory access to fail with a permission fault. 1030 1031 The feature is detected at runtime, and will remain as a 'nop' 1032 instruction if the cpu does not implement the feature. 1033 1034config ARM64_LSE_ATOMICS 1035 bool "Atomic instructions" 1036 help 1037 As part of the Large System Extensions, ARMv8.1 introduces new 1038 atomic instructions that are designed specifically to scale in 1039 very large systems. 1040 1041 Say Y here to make use of these instructions for the in-kernel 1042 atomic routines. This incurs a small overhead on CPUs that do 1043 not support these instructions and requires the kernel to be 1044 built with binutils >= 2.25. 1045 1046config ARM64_VHE 1047 bool "Enable support for Virtualization Host Extensions (VHE)" 1048 default y 1049 help 1050 Virtualization Host Extensions (VHE) allow the kernel to run 1051 directly at EL2 (instead of EL1) on processors that support 1052 it. This leads to better performance for KVM, as they reduce 1053 the cost of the world switch. 1054 1055 Selecting this option allows the VHE feature to be detected 1056 at runtime, and does not affect processors that do not 1057 implement this feature. 1058 1059endmenu 1060 1061menu "ARMv8.2 architectural features" 1062 1063config ARM64_UAO 1064 bool "Enable support for User Access Override (UAO)" 1065 default y 1066 help 1067 User Access Override (UAO; part of the ARMv8.2 Extensions) 1068 causes the 'unprivileged' variant of the load/store instructions to 1069 be overridden to be privileged. 1070 1071 This option changes get_user() and friends to use the 'unprivileged' 1072 variant of the load/store instructions. This ensures that user-space 1073 really did have access to the supplied memory. When addr_limit is 1074 set to kernel memory the UAO bit will be set, allowing privileged 1075 access to kernel memory. 1076 1077 Choosing this option will cause copy_to_user() et al to use user-space 1078 memory permissions. 1079 1080 The feature is detected at runtime, the kernel will use the 1081 regular load/store instructions if the cpu does not implement the 1082 feature. 1083 1084config ARM64_PMEM 1085 bool "Enable support for persistent memory" 1086 select ARCH_HAS_PMEM_API 1087 select ARCH_HAS_UACCESS_FLUSHCACHE 1088 help 1089 Say Y to enable support for the persistent memory API based on the 1090 ARMv8.2 DCPoP feature. 1091 1092 The feature is detected at runtime, and the kernel will use DC CVAC 1093 operations if DC CVAP is not supported (following the behaviour of 1094 DC CVAP itself if the system does not define a point of persistence). 1095 1096config ARM64_RAS_EXTN 1097 bool "Enable support for RAS CPU Extensions" 1098 default y 1099 help 1100 CPUs that support the Reliability, Availability and Serviceability 1101 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1102 errors, classify them and report them to software. 1103 1104 On CPUs with these extensions system software can use additional 1105 barriers to determine if faults are pending and read the 1106 classification from a new set of registers. 1107 1108 Selecting this feature will allow the kernel to use these barriers 1109 and access the new registers if the system supports the extension. 1110 Platform RAS features may additionally depend on firmware support. 1111 1112endmenu 1113 1114config ARM64_SVE 1115 bool "ARM Scalable Vector Extension support" 1116 default y 1117 help 1118 The Scalable Vector Extension (SVE) is an extension to the AArch64 1119 execution state which complements and extends the SIMD functionality 1120 of the base architecture to support much larger vectors and to enable 1121 additional vectorisation opportunities. 1122 1123 To enable use of this extension on CPUs that implement it, say Y. 1124 1125 Note that for architectural reasons, firmware _must_ implement SVE 1126 support when running on SVE capable hardware. The required support 1127 is present in: 1128 1129 * version 1.5 and later of the ARM Trusted Firmware 1130 * the AArch64 boot wrapper since commit 5e1261e08abf 1131 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1132 1133 For other firmware implementations, consult the firmware documentation 1134 or vendor. 1135 1136 If you need the kernel to boot on SVE-capable hardware with broken 1137 firmware, you may need to say N here until you get your firmware 1138 fixed. Otherwise, you may experience firmware panics or lockups when 1139 booting the kernel. If unsure and you are not observing these 1140 symptoms, you should assume that it is safe to say Y. 1141 1142config ARM64_MODULE_PLTS 1143 bool 1144 select HAVE_MOD_ARCH_SPECIFIC 1145 1146config RELOCATABLE 1147 bool 1148 help 1149 This builds the kernel as a Position Independent Executable (PIE), 1150 which retains all relocation metadata required to relocate the 1151 kernel binary at runtime to a different virtual address than the 1152 address it was linked at. 1153 Since AArch64 uses the RELA relocation format, this requires a 1154 relocation pass at runtime even if the kernel is loaded at the 1155 same address it was linked at. 1156 1157config RANDOMIZE_BASE 1158 bool "Randomize the address of the kernel image" 1159 select ARM64_MODULE_PLTS if MODULES 1160 select RELOCATABLE 1161 help 1162 Randomizes the virtual address at which the kernel image is 1163 loaded, as a security feature that deters exploit attempts 1164 relying on knowledge of the location of kernel internals. 1165 1166 It is the bootloader's job to provide entropy, by passing a 1167 random u64 value in /chosen/kaslr-seed at kernel entry. 1168 1169 When booting via the UEFI stub, it will invoke the firmware's 1170 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1171 to the kernel proper. In addition, it will randomise the physical 1172 location of the kernel Image as well. 1173 1174 If unsure, say N. 1175 1176config RANDOMIZE_MODULE_REGION_FULL 1177 bool "Randomize the module region over a 4 GB range" 1178 depends on RANDOMIZE_BASE 1179 default y 1180 help 1181 Randomizes the location of the module region inside a 4 GB window 1182 covering the core kernel. This way, it is less likely for modules 1183 to leak information about the location of core kernel data structures 1184 but it does imply that function calls between modules and the core 1185 kernel will need to be resolved via veneers in the module PLT. 1186 1187 When this option is not set, the module region will be randomized over 1188 a limited range that contains the [_stext, _etext] interval of the 1189 core kernel, so branch relocations are always in range. 1190 1191endmenu 1192 1193menu "Boot options" 1194 1195config ARM64_ACPI_PARKING_PROTOCOL 1196 bool "Enable support for the ARM64 ACPI parking protocol" 1197 depends on ACPI 1198 help 1199 Enable support for the ARM64 ACPI parking protocol. If disabled 1200 the kernel will not allow booting through the ARM64 ACPI parking 1201 protocol even if the corresponding data is present in the ACPI 1202 MADT table. 1203 1204config CMDLINE 1205 string "Default kernel command string" 1206 default "" 1207 help 1208 Provide a set of default command-line options at build time by 1209 entering them here. As a minimum, you should specify the the 1210 root device (e.g. root=/dev/nfs). 1211 1212config CMDLINE_FORCE 1213 bool "Always use the default kernel command string" 1214 help 1215 Always use the default kernel command string, even if the boot 1216 loader passes other arguments to the kernel. 1217 This is useful if you cannot or don't want to change the 1218 command-line options your boot loader passes to the kernel. 1219 1220config EFI_STUB 1221 bool 1222 1223config EFI 1224 bool "UEFI runtime support" 1225 depends on OF && !CPU_BIG_ENDIAN 1226 depends on KERNEL_MODE_NEON 1227 select LIBFDT 1228 select UCS2_STRING 1229 select EFI_PARAMS_FROM_FDT 1230 select EFI_RUNTIME_WRAPPERS 1231 select EFI_STUB 1232 select EFI_ARMSTUB 1233 default y 1234 help 1235 This option provides support for runtime services provided 1236 by UEFI firmware (such as non-volatile variables, realtime 1237 clock, and platform reset). A UEFI stub is also provided to 1238 allow the kernel to be booted as an EFI application. This 1239 is only useful on systems that have UEFI firmware. 1240 1241config DMI 1242 bool "Enable support for SMBIOS (DMI) tables" 1243 depends on EFI 1244 default y 1245 help 1246 This enables SMBIOS/DMI feature for systems. 1247 1248 This option is only useful on systems that have UEFI firmware. 1249 However, even with this option, the resultant kernel should 1250 continue to boot on existing non-UEFI platforms. 1251 1252endmenu 1253 1254menu "Userspace binary formats" 1255 1256source "fs/Kconfig.binfmt" 1257 1258config COMPAT 1259 bool "Kernel support for 32-bit EL0" 1260 depends on ARM64_4K_PAGES || EXPERT 1261 select COMPAT_BINFMT_ELF if BINFMT_ELF 1262 select HAVE_UID16 1263 select OLD_SIGSUSPEND3 1264 select COMPAT_OLD_SIGACTION 1265 help 1266 This option enables support for a 32-bit EL0 running under a 64-bit 1267 kernel at EL1. AArch32-specific components such as system calls, 1268 the user helper functions, VFP support and the ptrace interface are 1269 handled appropriately by the kernel. 1270 1271 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1272 that you will only be able to execute AArch32 binaries that were compiled 1273 with page size aligned segments. 1274 1275 If you want to execute 32-bit userspace applications, say Y. 1276 1277config SYSVIPC_COMPAT 1278 def_bool y 1279 depends on COMPAT && SYSVIPC 1280 1281endmenu 1282 1283menu "Power management options" 1284 1285source "kernel/power/Kconfig" 1286 1287config ARCH_HIBERNATION_POSSIBLE 1288 def_bool y 1289 depends on CPU_PM 1290 1291config ARCH_HIBERNATION_HEADER 1292 def_bool y 1293 depends on HIBERNATION 1294 1295config ARCH_SUSPEND_POSSIBLE 1296 def_bool y 1297 1298endmenu 1299 1300menu "CPU Power Management" 1301 1302source "drivers/cpuidle/Kconfig" 1303 1304source "drivers/cpufreq/Kconfig" 1305 1306endmenu 1307 1308source "net/Kconfig" 1309 1310source "drivers/Kconfig" 1311 1312source "drivers/firmware/Kconfig" 1313 1314source "drivers/acpi/Kconfig" 1315 1316source "fs/Kconfig" 1317 1318source "arch/arm64/kvm/Kconfig" 1319 1320source "arch/arm64/Kconfig.debug" 1321 1322source "security/Kconfig" 1323 1324source "crypto/Kconfig" 1325if CRYPTO 1326source "arch/arm64/crypto/Kconfig" 1327endif 1328 1329source "lib/Kconfig" 1330