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_SET_MEMORY 20 select ARCH_HAS_SG_CHAIN 21 select ARCH_HAS_STRICT_KERNEL_RWX 22 select ARCH_HAS_STRICT_MODULE_RWX 23 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 24 select ARCH_HAVE_NMI_SAFE_CMPXCHG if ACPI_APEI_SEA 25 select ARCH_USE_CMPXCHG_LOCKREF 26 select ARCH_SUPPORTS_MEMORY_FAILURE 27 select ARCH_SUPPORTS_LTO_CLANG 28 select ARCH_SUPPORTS_ATOMIC_RMW 29 select ARCH_SUPPORTS_NUMA_BALANCING 30 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 31 select ARCH_WANT_FRAME_POINTERS 32 select ARCH_HAS_UBSAN_SANITIZE_ALL 33 select ARM_AMBA 34 select ARM_ARCH_TIMER 35 select ARM_GIC 36 select AUDIT_ARCH_COMPAT_GENERIC 37 select ARM_GIC_V2M if PCI 38 select ARM_GIC_V3 39 select ARM_GIC_V3_ITS if PCI 40 select ARM_PSCI_FW 41 select BUILDTIME_EXTABLE_SORT 42 select CLONE_BACKWARDS 43 select COMMON_CLK 44 select CPU_PM if (SUSPEND || CPU_IDLE) 45 select DCACHE_WORD_ACCESS 46 select EDAC_SUPPORT 47 select FRAME_POINTER 48 select GENERIC_ALLOCATOR 49 select GENERIC_ARCH_TOPOLOGY 50 select GENERIC_CLOCKEVENTS 51 select GENERIC_CLOCKEVENTS_BROADCAST 52 select GENERIC_CPU_AUTOPROBE 53 select GENERIC_CPU_VULNERABILITIES 54 select GENERIC_EARLY_IOREMAP 55 select GENERIC_IDLE_POLL_SETUP 56 select GENERIC_IRQ_PROBE 57 select GENERIC_IRQ_SHOW 58 select GENERIC_IRQ_SHOW_LEVEL 59 select GENERIC_PCI_IOMAP 60 select GENERIC_SCHED_CLOCK 61 select GENERIC_SMP_IDLE_THREAD 62 select GENERIC_STRNCPY_FROM_USER 63 select GENERIC_STRNLEN_USER 64 select GENERIC_TIME_VSYSCALL 65 select HANDLE_DOMAIN_IRQ 66 select HARDIRQS_SW_RESEND 67 select HAVE_ACPI_APEI if (ACPI && EFI) 68 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 69 select HAVE_ARCH_AUDITSYSCALL 70 select HAVE_ARCH_BITREVERSE 71 select HAVE_ARCH_HUGE_VMAP 72 select HAVE_ARCH_JUMP_LABEL 73 select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 74 select HAVE_ARCH_KGDB 75 select HAVE_ARCH_MMAP_RND_BITS 76 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 77 select HAVE_ARCH_SECCOMP_FILTER 78 select HAVE_ARCH_TRACEHOOK 79 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 80 select HAVE_ARCH_VMAP_STACK 81 select HAVE_ARM_SMCCC 82 select HAVE_EBPF_JIT 83 select HAVE_C_RECORDMCOUNT 84 select HAVE_CC_STACKPROTECTOR 85 select HAVE_CMPXCHG_DOUBLE 86 select HAVE_CMPXCHG_LOCAL 87 select HAVE_CONTEXT_TRACKING 88 select HAVE_DEBUG_BUGVERBOSE 89 select HAVE_DEBUG_KMEMLEAK 90 select HAVE_DMA_API_DEBUG 91 select HAVE_DMA_CONTIGUOUS 92 select HAVE_DYNAMIC_FTRACE 93 select HAVE_EFFICIENT_UNALIGNED_ACCESS 94 select HAVE_FTRACE_MCOUNT_RECORD 95 select HAVE_FUNCTION_TRACER 96 select HAVE_FUNCTION_GRAPH_TRACER 97 select HAVE_GCC_PLUGINS 98 select HAVE_GENERIC_DMA_COHERENT 99 select HAVE_HW_BREAKPOINT if PERF_EVENTS 100 select HAVE_IRQ_TIME_ACCOUNTING 101 select HAVE_MEMBLOCK 102 select HAVE_MEMBLOCK_NODE_MAP if NUMA 103 select HAVE_NMI if ACPI_APEI_SEA 104 select HAVE_PATA_PLATFORM 105 select HAVE_PERF_EVENTS 106 select HAVE_PERF_REGS 107 select HAVE_PERF_USER_STACK_DUMP 108 select HAVE_REGS_AND_STACK_ACCESS_API 109 select HAVE_RCU_TABLE_FREE 110 select HAVE_SYSCALL_TRACEPOINTS 111 select HAVE_KPROBES 112 select HAVE_KRETPROBES 113 select IOMMU_DMA if IOMMU_SUPPORT 114 select IRQ_DOMAIN 115 select IRQ_FORCED_THREADING 116 select MODULES_USE_ELF_RELA 117 select NO_BOOTMEM 118 select OF 119 select OF_EARLY_FLATTREE 120 select OF_RESERVED_MEM 121 select PCI_ECAM if ACPI 122 select POWER_RESET 123 select POWER_SUPPLY 124 select SPARSE_IRQ 125 select SYSCTL_EXCEPTION_TRACE 126 select THREAD_INFO_IN_TASK 127 help 128 ARM 64-bit (AArch64) Linux support. 129 130config 64BIT 131 def_bool y 132 133config ARCH_PHYS_ADDR_T_64BIT 134 def_bool y 135 136config MMU 137 def_bool y 138 139config ARM64_PAGE_SHIFT 140 int 141 default 16 if ARM64_64K_PAGES 142 default 14 if ARM64_16K_PAGES 143 default 12 144 145config ARM64_CONT_SHIFT 146 int 147 default 5 if ARM64_64K_PAGES 148 default 7 if ARM64_16K_PAGES 149 default 4 150 151config ARCH_MMAP_RND_BITS_MIN 152 default 14 if ARM64_64K_PAGES 153 default 16 if ARM64_16K_PAGES 154 default 18 155 156# max bits determined by the following formula: 157# VA_BITS - PAGE_SHIFT - 3 158config ARCH_MMAP_RND_BITS_MAX 159 default 19 if ARM64_VA_BITS=36 160 default 24 if ARM64_VA_BITS=39 161 default 27 if ARM64_VA_BITS=42 162 default 30 if ARM64_VA_BITS=47 163 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 164 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 165 default 33 if ARM64_VA_BITS=48 166 default 14 if ARM64_64K_PAGES 167 default 16 if ARM64_16K_PAGES 168 default 18 169 170config ARCH_MMAP_RND_COMPAT_BITS_MIN 171 default 7 if ARM64_64K_PAGES 172 default 9 if ARM64_16K_PAGES 173 default 11 174 175config ARCH_MMAP_RND_COMPAT_BITS_MAX 176 default 16 177 178config NO_IOPORT_MAP 179 def_bool y if !PCI 180 181config STACKTRACE_SUPPORT 182 def_bool y 183 184config ILLEGAL_POINTER_VALUE 185 hex 186 default 0xdead000000000000 187 188config LOCKDEP_SUPPORT 189 def_bool y 190 191config TRACE_IRQFLAGS_SUPPORT 192 def_bool y 193 194config RWSEM_XCHGADD_ALGORITHM 195 def_bool y 196 197config GENERIC_BUG 198 def_bool y 199 depends on BUG 200 201config GENERIC_BUG_RELATIVE_POINTERS 202 def_bool y 203 depends on GENERIC_BUG 204 205config GENERIC_HWEIGHT 206 def_bool y 207 208config GENERIC_CSUM 209 def_bool y 210 211config GENERIC_CALIBRATE_DELAY 212 def_bool y 213 214config ZONE_DMA 215 def_bool y 216 217config HAVE_GENERIC_GUP 218 def_bool y 219 220config ARCH_DMA_ADDR_T_64BIT 221 def_bool y 222 223config NEED_DMA_MAP_STATE 224 def_bool y 225 226config NEED_SG_DMA_LENGTH 227 def_bool y 228 229config SMP 230 def_bool y 231 232config SWIOTLB 233 def_bool y 234 235config IOMMU_HELPER 236 def_bool SWIOTLB 237 238config KERNEL_MODE_NEON 239 def_bool y 240 241config FIX_EARLYCON_MEM 242 def_bool y 243 244config PGTABLE_LEVELS 245 int 246 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 247 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 248 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 249 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 250 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 251 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 252 253config ARCH_SUPPORTS_UPROBES 254 def_bool y 255 256config ARCH_PROC_KCORE_TEXT 257 def_bool y 258 259source "init/Kconfig" 260 261source "kernel/Kconfig.freezer" 262 263source "arch/arm64/Kconfig.platforms" 264 265menu "Bus support" 266 267config PCI 268 bool "PCI support" 269 help 270 This feature enables support for PCI bus system. If you say Y 271 here, the kernel will include drivers and infrastructure code 272 to support PCI bus devices. 273 274config PCI_DOMAINS 275 def_bool PCI 276 277config PCI_DOMAINS_GENERIC 278 def_bool PCI 279 280config PCI_SYSCALL 281 def_bool PCI 282 283source "drivers/pci/Kconfig" 284 285endmenu 286 287menu "Kernel Features" 288 289menu "ARM errata workarounds via the alternatives framework" 290 291config ARM64_ERRATUM_826319 292 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 293 default y 294 help 295 This option adds an alternative code sequence to work around ARM 296 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 297 AXI master interface and an L2 cache. 298 299 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 300 and is unable to accept a certain write via this interface, it will 301 not progress on read data presented on the read data channel and the 302 system can deadlock. 303 304 The workaround promotes data cache clean instructions to 305 data cache clean-and-invalidate. 306 Please note that this does not necessarily enable the workaround, 307 as it depends on the alternative framework, which will only patch 308 the kernel if an affected CPU is detected. 309 310 If unsure, say Y. 311 312config ARM64_ERRATUM_827319 313 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 314 default y 315 help 316 This option adds an alternative code sequence to work around ARM 317 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 318 master interface and an L2 cache. 319 320 Under certain conditions this erratum can cause a clean line eviction 321 to occur at the same time as another transaction to the same address 322 on the AMBA 5 CHI interface, which can cause data corruption if the 323 interconnect reorders the two transactions. 324 325 The workaround promotes data cache clean instructions to 326 data cache clean-and-invalidate. 327 Please note that this does not necessarily enable the workaround, 328 as it depends on the alternative framework, which will only patch 329 the kernel if an affected CPU is detected. 330 331 If unsure, say Y. 332 333config ARM64_ERRATUM_824069 334 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 335 default y 336 help 337 This option adds an alternative code sequence to work around ARM 338 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 339 to a coherent interconnect. 340 341 If a Cortex-A53 processor is executing a store or prefetch for 342 write instruction at the same time as a processor in another 343 cluster is executing a cache maintenance operation to the same 344 address, then this erratum might cause a clean cache line to be 345 incorrectly marked as dirty. 346 347 The workaround promotes data cache clean instructions to 348 data cache clean-and-invalidate. 349 Please note that this option does not necessarily enable the 350 workaround, as it depends on the alternative framework, which will 351 only patch the kernel if an affected CPU is detected. 352 353 If unsure, say Y. 354 355config ARM64_ERRATUM_819472 356 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 357 default y 358 help 359 This option adds an alternative code sequence to work around ARM 360 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 361 present when it is connected to a coherent interconnect. 362 363 If the processor is executing a load and store exclusive sequence at 364 the same time as a processor in another cluster is executing a cache 365 maintenance operation to the same address, then this erratum might 366 cause data corruption. 367 368 The workaround promotes data cache clean instructions to 369 data cache clean-and-invalidate. 370 Please note that this does not necessarily enable the workaround, 371 as it depends on the alternative framework, which will only patch 372 the kernel if an affected CPU is detected. 373 374 If unsure, say Y. 375 376config ARM64_ERRATUM_832075 377 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 378 default y 379 help 380 This option adds an alternative code sequence to work around ARM 381 erratum 832075 on Cortex-A57 parts up to r1p2. 382 383 Affected Cortex-A57 parts might deadlock when exclusive load/store 384 instructions to Write-Back memory are mixed with Device loads. 385 386 The workaround is to promote device loads to use Load-Acquire 387 semantics. 388 Please note that this does not necessarily enable the workaround, 389 as it depends on the alternative framework, which will only patch 390 the kernel if an affected CPU is detected. 391 392 If unsure, say Y. 393 394config ARM64_ERRATUM_834220 395 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 396 depends on KVM 397 default y 398 help 399 This option adds an alternative code sequence to work around ARM 400 erratum 834220 on Cortex-A57 parts up to r1p2. 401 402 Affected Cortex-A57 parts might report a Stage 2 translation 403 fault as the result of a Stage 1 fault for load crossing a 404 page boundary when there is a permission or device memory 405 alignment fault at Stage 1 and a translation fault at Stage 2. 406 407 The workaround is to verify that the Stage 1 translation 408 doesn't generate a fault before handling the Stage 2 fault. 409 Please note that this does not necessarily enable the workaround, 410 as it depends on the alternative framework, which will only patch 411 the kernel if an affected CPU is detected. 412 413 If unsure, say Y. 414 415config ARM64_ERRATUM_845719 416 bool "Cortex-A53: 845719: a load might read incorrect data" 417 depends on COMPAT 418 default y 419 help 420 This option adds an alternative code sequence to work around ARM 421 erratum 845719 on Cortex-A53 parts up to r0p4. 422 423 When running a compat (AArch32) userspace on an affected Cortex-A53 424 part, a load at EL0 from a virtual address that matches the bottom 32 425 bits of the virtual address used by a recent load at (AArch64) EL1 426 might return incorrect data. 427 428 The workaround is to write the contextidr_el1 register on exception 429 return to a 32-bit task. 430 Please note that this does not necessarily enable the workaround, 431 as it depends on the alternative framework, which will only patch 432 the kernel if an affected CPU is detected. 433 434 If unsure, say Y. 435 436config ARM64_ERRATUM_843419 437 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 438 default y if !LTO_CLANG 439 select ARM64_MODULE_CMODEL_LARGE if MODULES 440 help 441 This option links the kernel with '--fix-cortex-a53-843419' and 442 builds modules using the large memory model in order to avoid the use 443 of the ADRP instruction, which can cause a subsequent memory access 444 to use an incorrect address on Cortex-A53 parts up to r0p4. 445 446 If unsure, say Y. 447 448config ARM64_ERRATUM_1024718 449 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 450 default y 451 help 452 This option adds work around for Arm Cortex-A55 Erratum 1024718. 453 454 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 455 update of the hardware dirty bit when the DBM/AP bits are updated 456 without a break-before-make. The work around is to disable the usage 457 of hardware DBM locally on the affected cores. CPUs not affected by 458 erratum will continue to use the feature. 459 460 If unsure, say Y. 461 462config CAVIUM_ERRATUM_22375 463 bool "Cavium erratum 22375, 24313" 464 default y 465 help 466 Enable workaround for erratum 22375, 24313. 467 468 This implements two gicv3-its errata workarounds for ThunderX. Both 469 with small impact affecting only ITS table allocation. 470 471 erratum 22375: only alloc 8MB table size 472 erratum 24313: ignore memory access type 473 474 The fixes are in ITS initialization and basically ignore memory access 475 type and table size provided by the TYPER and BASER registers. 476 477 If unsure, say Y. 478 479config CAVIUM_ERRATUM_23144 480 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 481 depends on NUMA 482 default y 483 help 484 ITS SYNC command hang for cross node io and collections/cpu mapping. 485 486 If unsure, say Y. 487 488config CAVIUM_ERRATUM_23154 489 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 490 default y 491 help 492 The gicv3 of ThunderX requires a modified version for 493 reading the IAR status to ensure data synchronization 494 (access to icc_iar1_el1 is not sync'ed before and after). 495 496 If unsure, say Y. 497 498config CAVIUM_ERRATUM_27456 499 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 500 default y 501 help 502 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 503 instructions may cause the icache to become corrupted if it 504 contains data for a non-current ASID. The fix is to 505 invalidate the icache when changing the mm context. 506 507 If unsure, say Y. 508 509config CAVIUM_ERRATUM_30115 510 bool "Cavium erratum 30115: Guest may disable interrupts in host" 511 default y 512 help 513 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 514 1.2, and T83 Pass 1.0, KVM guest execution may disable 515 interrupts in host. Trapping both GICv3 group-0 and group-1 516 accesses sidesteps the issue. 517 518 If unsure, say Y. 519 520config QCOM_FALKOR_ERRATUM_1003 521 bool "Falkor E1003: Incorrect translation due to ASID change" 522 default y 523 help 524 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 525 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 526 in TTBR1_EL1, this situation only occurs in the entry trampoline and 527 then only for entries in the walk cache, since the leaf translation 528 is unchanged. Work around the erratum by invalidating the walk cache 529 entries for the trampoline before entering the kernel proper. 530 531config QCOM_FALKOR_ERRATUM_1009 532 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 533 default y 534 help 535 On Falkor v1, the CPU may prematurely complete a DSB following a 536 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 537 one more time to fix the issue. 538 539 If unsure, say Y. 540 541config QCOM_QDF2400_ERRATUM_0065 542 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 543 default y 544 help 545 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 546 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 547 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 548 549 If unsure, say Y. 550 551config QCOM_FALKOR_ERRATUM_E1041 552 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 553 default y 554 help 555 Falkor CPU may speculatively fetch instructions from an improper 556 memory location when MMU translation is changed from SCTLR_ELn[M]=1 557 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 558 559 If unsure, say Y. 560 561endmenu 562 563 564choice 565 prompt "Page size" 566 default ARM64_4K_PAGES 567 help 568 Page size (translation granule) configuration. 569 570config ARM64_4K_PAGES 571 bool "4KB" 572 help 573 This feature enables 4KB pages support. 574 575config ARM64_16K_PAGES 576 bool "16KB" 577 help 578 The system will use 16KB pages support. AArch32 emulation 579 requires applications compiled with 16K (or a multiple of 16K) 580 aligned segments. 581 582config ARM64_64K_PAGES 583 bool "64KB" 584 help 585 This feature enables 64KB pages support (4KB by default) 586 allowing only two levels of page tables and faster TLB 587 look-up. AArch32 emulation requires applications compiled 588 with 64K aligned segments. 589 590endchoice 591 592choice 593 prompt "Virtual address space size" 594 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 595 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 596 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 597 help 598 Allows choosing one of multiple possible virtual address 599 space sizes. The level of translation table is determined by 600 a combination of page size and virtual address space size. 601 602config ARM64_VA_BITS_36 603 bool "36-bit" if EXPERT 604 depends on ARM64_16K_PAGES 605 606config ARM64_VA_BITS_39 607 bool "39-bit" 608 depends on ARM64_4K_PAGES 609 610config ARM64_VA_BITS_42 611 bool "42-bit" 612 depends on ARM64_64K_PAGES 613 614config ARM64_VA_BITS_47 615 bool "47-bit" 616 depends on ARM64_16K_PAGES 617 618config ARM64_VA_BITS_48 619 bool "48-bit" 620 621endchoice 622 623config ARM64_VA_BITS 624 int 625 default 36 if ARM64_VA_BITS_36 626 default 39 if ARM64_VA_BITS_39 627 default 42 if ARM64_VA_BITS_42 628 default 47 if ARM64_VA_BITS_47 629 default 48 if ARM64_VA_BITS_48 630 631config CPU_BIG_ENDIAN 632 bool "Build big-endian kernel" 633 help 634 Say Y if you plan on running a kernel in big-endian mode. 635 636config SCHED_MC 637 bool "Multi-core scheduler support" 638 help 639 Multi-core scheduler support improves the CPU scheduler's decision 640 making when dealing with multi-core CPU chips at a cost of slightly 641 increased overhead in some places. If unsure say N here. 642 643config SCHED_SMT 644 bool "SMT scheduler support" 645 help 646 Improves the CPU scheduler's decision making when dealing with 647 MultiThreading at a cost of slightly increased overhead in some 648 places. If unsure say N here. 649 650config NR_CPUS 651 int "Maximum number of CPUs (2-4096)" 652 range 2 4096 653 # These have to remain sorted largest to smallest 654 default "64" 655 656config HOTPLUG_CPU 657 bool "Support for hot-pluggable CPUs" 658 select GENERIC_IRQ_MIGRATION 659 help 660 Say Y here to experiment with turning CPUs off and on. CPUs 661 can be controlled through /sys/devices/system/cpu. 662 663# Common NUMA Features 664config NUMA 665 bool "Numa Memory Allocation and Scheduler Support" 666 select ACPI_NUMA if ACPI 667 select OF_NUMA 668 help 669 Enable NUMA (Non Uniform Memory Access) support. 670 671 The kernel will try to allocate memory used by a CPU on the 672 local memory of the CPU and add some more 673 NUMA awareness to the kernel. 674 675config NODES_SHIFT 676 int "Maximum NUMA Nodes (as a power of 2)" 677 range 1 10 678 default "2" 679 depends on NEED_MULTIPLE_NODES 680 help 681 Specify the maximum number of NUMA Nodes available on the target 682 system. Increases memory reserved to accommodate various tables. 683 684config USE_PERCPU_NUMA_NODE_ID 685 def_bool y 686 depends on NUMA 687 688config HAVE_SETUP_PER_CPU_AREA 689 def_bool y 690 depends on NUMA 691 692config NEED_PER_CPU_EMBED_FIRST_CHUNK 693 def_bool y 694 depends on NUMA 695 696config HOLES_IN_ZONE 697 def_bool y 698 699source kernel/Kconfig.preempt 700source kernel/Kconfig.hz 701 702config ARCH_SUPPORTS_DEBUG_PAGEALLOC 703 def_bool y 704 705config ARCH_HAS_HOLES_MEMORYMODEL 706 def_bool y if SPARSEMEM 707 708config ARCH_SPARSEMEM_ENABLE 709 def_bool y 710 select SPARSEMEM_VMEMMAP_ENABLE 711 712config ARCH_SPARSEMEM_DEFAULT 713 def_bool ARCH_SPARSEMEM_ENABLE 714 715config ARCH_SELECT_MEMORY_MODEL 716 def_bool ARCH_SPARSEMEM_ENABLE 717 718config HAVE_ARCH_PFN_VALID 719 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM 720 721config HW_PERF_EVENTS 722 def_bool y 723 depends on ARM_PMU 724 725config SYS_SUPPORTS_HUGETLBFS 726 def_bool y 727 728config ARCH_WANT_HUGE_PMD_SHARE 729 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 730 731config ARCH_HAS_CACHE_LINE_SIZE 732 def_bool y 733 734source "mm/Kconfig" 735 736config SECCOMP 737 bool "Enable seccomp to safely compute untrusted bytecode" 738 ---help--- 739 This kernel feature is useful for number crunching applications 740 that may need to compute untrusted bytecode during their 741 execution. By using pipes or other transports made available to 742 the process as file descriptors supporting the read/write 743 syscalls, it's possible to isolate those applications in 744 their own address space using seccomp. Once seccomp is 745 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 746 and the task is only allowed to execute a few safe syscalls 747 defined by each seccomp mode. 748 749config PARAVIRT 750 bool "Enable paravirtualization code" 751 help 752 This changes the kernel so it can modify itself when it is run 753 under a hypervisor, potentially improving performance significantly 754 over full virtualization. 755 756config PARAVIRT_TIME_ACCOUNTING 757 bool "Paravirtual steal time accounting" 758 select PARAVIRT 759 default n 760 help 761 Select this option to enable fine granularity task steal time 762 accounting. Time spent executing other tasks in parallel with 763 the current vCPU is discounted from the vCPU power. To account for 764 that, there can be a small performance impact. 765 766 If in doubt, say N here. 767 768config KEXEC 769 depends on PM_SLEEP_SMP 770 select KEXEC_CORE 771 bool "kexec system call" 772 ---help--- 773 kexec is a system call that implements the ability to shutdown your 774 current kernel, and to start another kernel. It is like a reboot 775 but it is independent of the system firmware. And like a reboot 776 you can start any kernel with it, not just Linux. 777 778config CRASH_DUMP 779 bool "Build kdump crash kernel" 780 help 781 Generate crash dump after being started by kexec. This should 782 be normally only set in special crash dump kernels which are 783 loaded in the main kernel with kexec-tools into a specially 784 reserved region and then later executed after a crash by 785 kdump/kexec. 786 787 For more details see Documentation/kdump/kdump.txt 788 789config XEN_DOM0 790 def_bool y 791 depends on XEN 792 793config XEN 794 bool "Xen guest support on ARM64" 795 depends on ARM64 && OF 796 select SWIOTLB_XEN 797 select PARAVIRT 798 help 799 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 800 801config FORCE_MAX_ZONEORDER 802 int 803 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 804 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 805 default "11" 806 help 807 The kernel memory allocator divides physically contiguous memory 808 blocks into "zones", where each zone is a power of two number of 809 pages. This option selects the largest power of two that the kernel 810 keeps in the memory allocator. If you need to allocate very large 811 blocks of physically contiguous memory, then you may need to 812 increase this value. 813 814 This config option is actually maximum order plus one. For example, 815 a value of 11 means that the largest free memory block is 2^10 pages. 816 817 We make sure that we can allocate upto a HugePage size for each configuration. 818 Hence we have : 819 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 820 821 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 822 4M allocations matching the default size used by generic code. 823 824config UNMAP_KERNEL_AT_EL0 825 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 826 default y 827 help 828 Speculation attacks against some high-performance processors can 829 be used to bypass MMU permission checks and leak kernel data to 830 userspace. This can be defended against by unmapping the kernel 831 when running in userspace, mapping it back in on exception entry 832 via a trampoline page in the vector table. 833 834 If unsure, say Y. 835 836config HARDEN_BRANCH_PREDICTOR 837 bool "Harden the branch predictor against aliasing attacks" if EXPERT 838 default y 839 help 840 Speculation attacks against some high-performance processors rely on 841 being able to manipulate the branch predictor for a victim context by 842 executing aliasing branches in the attacker context. Such attacks 843 can be partially mitigated against by clearing internal branch 844 predictor state and limiting the prediction logic in some situations. 845 846 This config option will take CPU-specific actions to harden the 847 branch predictor against aliasing attacks and may rely on specific 848 instruction sequences or control bits being set by the system 849 firmware. 850 851 If unsure, say Y. 852 853config ARM64_SSBD 854 bool "Speculative Store Bypass Disable" if EXPERT 855 default y 856 help 857 This enables mitigation of the bypassing of previous stores 858 by speculative loads. 859 860 If unsure, say Y. 861 862menuconfig ARMV8_DEPRECATED 863 bool "Emulate deprecated/obsolete ARMv8 instructions" 864 depends on COMPAT 865 help 866 Legacy software support may require certain instructions 867 that have been deprecated or obsoleted in the architecture. 868 869 Enable this config to enable selective emulation of these 870 features. 871 872 If unsure, say Y 873 874if ARMV8_DEPRECATED 875 876config SWP_EMULATION 877 bool "Emulate SWP/SWPB instructions" 878 help 879 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 880 they are always undefined. Say Y here to enable software 881 emulation of these instructions for userspace using LDXR/STXR. 882 883 In some older versions of glibc [<=2.8] SWP is used during futex 884 trylock() operations with the assumption that the code will not 885 be preempted. This invalid assumption may be more likely to fail 886 with SWP emulation enabled, leading to deadlock of the user 887 application. 888 889 NOTE: when accessing uncached shared regions, LDXR/STXR rely 890 on an external transaction monitoring block called a global 891 monitor to maintain update atomicity. If your system does not 892 implement a global monitor, this option can cause programs that 893 perform SWP operations to uncached memory to deadlock. 894 895 If unsure, say Y 896 897config CP15_BARRIER_EMULATION 898 bool "Emulate CP15 Barrier instructions" 899 help 900 The CP15 barrier instructions - CP15ISB, CP15DSB, and 901 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 902 strongly recommended to use the ISB, DSB, and DMB 903 instructions instead. 904 905 Say Y here to enable software emulation of these 906 instructions for AArch32 userspace code. When this option is 907 enabled, CP15 barrier usage is traced which can help 908 identify software that needs updating. 909 910 If unsure, say Y 911 912config SETEND_EMULATION 913 bool "Emulate SETEND instruction" 914 help 915 The SETEND instruction alters the data-endianness of the 916 AArch32 EL0, and is deprecated in ARMv8. 917 918 Say Y here to enable software emulation of the instruction 919 for AArch32 userspace code. 920 921 Note: All the cpus on the system must have mixed endian support at EL0 922 for this feature to be enabled. If a new CPU - which doesn't support mixed 923 endian - is hotplugged in after this feature has been enabled, there could 924 be unexpected results in the applications. 925 926 If unsure, say Y 927endif 928 929config ARM64_SW_TTBR0_PAN 930 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 931 help 932 Enabling this option prevents the kernel from accessing 933 user-space memory directly by pointing TTBR0_EL1 to a reserved 934 zeroed area and reserved ASID. The user access routines 935 restore the valid TTBR0_EL1 temporarily. 936 937menu "ARMv8.1 architectural features" 938 939config ARM64_HW_AFDBM 940 bool "Support for hardware updates of the Access and Dirty page flags" 941 default y 942 help 943 The ARMv8.1 architecture extensions introduce support for 944 hardware updates of the access and dirty information in page 945 table entries. When enabled in TCR_EL1 (HA and HD bits) on 946 capable processors, accesses to pages with PTE_AF cleared will 947 set this bit instead of raising an access flag fault. 948 Similarly, writes to read-only pages with the DBM bit set will 949 clear the read-only bit (AP[2]) instead of raising a 950 permission fault. 951 952 Kernels built with this configuration option enabled continue 953 to work on pre-ARMv8.1 hardware and the performance impact is 954 minimal. If unsure, say Y. 955 956config ARM64_PAN 957 bool "Enable support for Privileged Access Never (PAN)" 958 default y 959 help 960 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 961 prevents the kernel or hypervisor from accessing user-space (EL0) 962 memory directly. 963 964 Choosing this option will cause any unprotected (not using 965 copy_to_user et al) memory access to fail with a permission fault. 966 967 The feature is detected at runtime, and will remain as a 'nop' 968 instruction if the cpu does not implement the feature. 969 970config ARM64_LSE_ATOMICS 971 bool "Atomic instructions" 972 help 973 As part of the Large System Extensions, ARMv8.1 introduces new 974 atomic instructions that are designed specifically to scale in 975 very large systems. 976 977 Say Y here to make use of these instructions for the in-kernel 978 atomic routines. This incurs a small overhead on CPUs that do 979 not support these instructions and requires the kernel to be 980 built with binutils >= 2.25. 981 982config ARM64_VHE 983 bool "Enable support for Virtualization Host Extensions (VHE)" 984 default y 985 help 986 Virtualization Host Extensions (VHE) allow the kernel to run 987 directly at EL2 (instead of EL1) on processors that support 988 it. This leads to better performance for KVM, as they reduce 989 the cost of the world switch. 990 991 Selecting this option allows the VHE feature to be detected 992 at runtime, and does not affect processors that do not 993 implement this feature. 994 995endmenu 996 997menu "ARMv8.2 architectural features" 998 999config ARM64_UAO 1000 bool "Enable support for User Access Override (UAO)" 1001 default y 1002 help 1003 User Access Override (UAO; part of the ARMv8.2 Extensions) 1004 causes the 'unprivileged' variant of the load/store instructions to 1005 be overriden to be privileged. 1006 1007 This option changes get_user() and friends to use the 'unprivileged' 1008 variant of the load/store instructions. This ensures that user-space 1009 really did have access to the supplied memory. When addr_limit is 1010 set to kernel memory the UAO bit will be set, allowing privileged 1011 access to kernel memory. 1012 1013 Choosing this option will cause copy_to_user() et al to use user-space 1014 memory permissions. 1015 1016 The feature is detected at runtime, the kernel will use the 1017 regular load/store instructions if the cpu does not implement the 1018 feature. 1019 1020config ARM64_PMEM 1021 bool "Enable support for persistent memory" 1022 select ARCH_HAS_PMEM_API 1023 select ARCH_HAS_UACCESS_FLUSHCACHE 1024 help 1025 Say Y to enable support for the persistent memory API based on the 1026 ARMv8.2 DCPoP feature. 1027 1028 The feature is detected at runtime, and the kernel will use DC CVAC 1029 operations if DC CVAP is not supported (following the behaviour of 1030 DC CVAP itself if the system does not define a point of persistence). 1031 1032endmenu 1033 1034config ARM64_MODULE_CMODEL_LARGE 1035 bool 1036 1037config ARM64_MODULE_PLTS 1038 bool 1039 select ARM64_MODULE_CMODEL_LARGE 1040 select HAVE_MOD_ARCH_SPECIFIC 1041 1042config RELOCATABLE 1043 bool 1044 help 1045 This builds the kernel as a Position Independent Executable (PIE), 1046 which retains all relocation metadata required to relocate the 1047 kernel binary at runtime to a different virtual address than the 1048 address it was linked at. 1049 Since AArch64 uses the RELA relocation format, this requires a 1050 relocation pass at runtime even if the kernel is loaded at the 1051 same address it was linked at. 1052 1053config RANDOMIZE_BASE 1054 bool "Randomize the address of the kernel image" 1055 select ARM64_MODULE_PLTS if MODULES 1056 select RELOCATABLE 1057 help 1058 Randomizes the virtual address at which the kernel image is 1059 loaded, as a security feature that deters exploit attempts 1060 relying on knowledge of the location of kernel internals. 1061 1062 It is the bootloader's job to provide entropy, by passing a 1063 random u64 value in /chosen/kaslr-seed at kernel entry. 1064 1065 When booting via the UEFI stub, it will invoke the firmware's 1066 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1067 to the kernel proper. In addition, it will randomise the physical 1068 location of the kernel Image as well. 1069 1070 If unsure, say N. 1071 1072config RANDOMIZE_MODULE_REGION_FULL 1073 bool "Randomize the module region independently from the core kernel" 1074 depends on RANDOMIZE_BASE && !LTO_CLANG 1075 default y 1076 help 1077 Randomizes the location of the module region without considering the 1078 location of the core kernel. This way, it is impossible for modules 1079 to leak information about the location of core kernel data structures 1080 but it does imply that function calls between modules and the core 1081 kernel will need to be resolved via veneers in the module PLT. 1082 1083 When this option is not set, the module region will be randomized over 1084 a limited range that contains the [_stext, _etext] interval of the 1085 core kernel, so branch relocations are always in range. 1086 1087endmenu 1088 1089menu "Boot options" 1090 1091config ARM64_ACPI_PARKING_PROTOCOL 1092 bool "Enable support for the ARM64 ACPI parking protocol" 1093 depends on ACPI 1094 help 1095 Enable support for the ARM64 ACPI parking protocol. If disabled 1096 the kernel will not allow booting through the ARM64 ACPI parking 1097 protocol even if the corresponding data is present in the ACPI 1098 MADT table. 1099 1100config CMDLINE 1101 string "Default kernel command string" 1102 default "" 1103 help 1104 Provide a set of default command-line options at build time by 1105 entering them here. As a minimum, you should specify the the 1106 root device (e.g. root=/dev/nfs). 1107 1108choice 1109 prompt "Kernel command line type" if CMDLINE != "" 1110 default CMDLINE_FROM_BOOTLOADER 1111 1112config CMDLINE_FROM_BOOTLOADER 1113 bool "Use bootloader kernel arguments if available" 1114 help 1115 Uses the command-line options passed by the boot loader. If 1116 the boot loader doesn't provide any, the default kernel command 1117 string provided in CMDLINE will be used. 1118 1119config CMDLINE_EXTEND 1120 bool "Extend bootloader kernel arguments" 1121 help 1122 The command-line arguments provided by the boot loader will be 1123 appended to the default kernel command string. 1124 1125config CMDLINE_FORCE 1126 bool "Always use the default kernel command string" 1127 help 1128 Always use the default kernel command string, even if the boot 1129 loader passes other arguments to the kernel. 1130 This is useful if you cannot or don't want to change the 1131 command-line options your boot loader passes to the kernel. 1132endchoice 1133 1134config EFI_STUB 1135 bool 1136 1137config EFI 1138 bool "UEFI runtime support" 1139 depends on OF && !CPU_BIG_ENDIAN 1140 select LIBFDT 1141 select UCS2_STRING 1142 select EFI_PARAMS_FROM_FDT 1143 select EFI_RUNTIME_WRAPPERS 1144 select EFI_STUB 1145 select EFI_ARMSTUB 1146 default y 1147 help 1148 This option provides support for runtime services provided 1149 by UEFI firmware (such as non-volatile variables, realtime 1150 clock, and platform reset). A UEFI stub is also provided to 1151 allow the kernel to be booted as an EFI application. This 1152 is only useful on systems that have UEFI firmware. 1153 1154config DMI 1155 bool "Enable support for SMBIOS (DMI) tables" 1156 depends on EFI 1157 default y 1158 help 1159 This enables SMBIOS/DMI feature for systems. 1160 1161 This option is only useful on systems that have UEFI firmware. 1162 However, even with this option, the resultant kernel should 1163 continue to boot on existing non-UEFI platforms. 1164 1165config BUILD_ARM64_APPENDED_DTB_IMAGE 1166 bool "Build a concatenated Image.gz/dtb by default" 1167 depends on OF 1168 help 1169 Enabling this option will cause a concatenated Image.gz and list of 1170 DTBs to be built by default (instead of a standalone Image.gz.) 1171 The image will built in arch/arm64/boot/Image.gz-dtb 1172 1173choice 1174 prompt "Appended DTB Kernel Image name" 1175 depends on BUILD_ARM64_APPENDED_DTB_IMAGE 1176 help 1177 Enabling this option will cause a specific kernel image Image or 1178 Image.gz to be used for final image creation. 1179 The image will built in arch/arm64/boot/IMAGE-NAME-dtb 1180 1181 config IMG_GZ_DTB 1182 bool "Image.gz-dtb" 1183 config IMG_DTB 1184 bool "Image-dtb" 1185endchoice 1186 1187config BUILD_ARM64_APPENDED_KERNEL_IMAGE_NAME 1188 string 1189 depends on BUILD_ARM64_APPENDED_DTB_IMAGE 1190 default "Image.gz-dtb" if IMG_GZ_DTB 1191 default "Image-dtb" if IMG_DTB 1192 1193config BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES 1194 string "Default dtb names" 1195 depends on BUILD_ARM64_APPENDED_DTB_IMAGE 1196 help 1197 Space separated list of names of dtbs to append when 1198 building a concatenated Image.gz-dtb. 1199 1200endmenu 1201 1202menu "Userspace binary formats" 1203 1204source "fs/Kconfig.binfmt" 1205 1206config COMPAT 1207 bool "Kernel support for 32-bit EL0" 1208 depends on ARM64_4K_PAGES || EXPERT 1209 select COMPAT_BINFMT_ELF if BINFMT_ELF 1210 select HAVE_UID16 1211 select OLD_SIGSUSPEND3 1212 select COMPAT_OLD_SIGACTION 1213 help 1214 This option enables support for a 32-bit EL0 running under a 64-bit 1215 kernel at EL1. AArch32-specific components such as system calls, 1216 the user helper functions, VFP support and the ptrace interface are 1217 handled appropriately by the kernel. 1218 1219 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1220 that you will only be able to execute AArch32 binaries that were compiled 1221 with page size aligned segments. 1222 1223 If you want to execute 32-bit userspace applications, say Y. 1224 1225config SYSVIPC_COMPAT 1226 def_bool y 1227 depends on COMPAT && SYSVIPC 1228 1229endmenu 1230 1231menu "Power management options" 1232 1233source "kernel/power/Kconfig" 1234 1235config ARCH_HIBERNATION_POSSIBLE 1236 def_bool y 1237 depends on CPU_PM 1238 1239config ARCH_HIBERNATION_HEADER 1240 def_bool y 1241 depends on HIBERNATION 1242 1243config ARCH_SUSPEND_POSSIBLE 1244 def_bool y 1245 1246endmenu 1247 1248menu "CPU Power Management" 1249 1250source "drivers/cpuidle/Kconfig" 1251 1252source "drivers/cpufreq/Kconfig" 1253 1254endmenu 1255 1256source "net/Kconfig" 1257 1258source "drivers/Kconfig" 1259 1260source "drivers/firmware/Kconfig" 1261 1262source "drivers/acpi/Kconfig" 1263 1264source "fs/Kconfig" 1265 1266source "arch/arm64/kvm/Kconfig" 1267 1268source "arch/arm64/Kconfig.debug" 1269 1270source "security/Kconfig" 1271 1272source "crypto/Kconfig" 1273if CRYPTO 1274source "arch/arm64/crypto/Kconfig" 1275endif 1276 1277source "lib/Kconfig" 1278