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 && PCI) 9 select ACPI_SPCR_TABLE if ACPI 10 select ACPI_PPTT if ACPI 11 select ARCH_CLOCKSOURCE_DATA 12 select ARCH_HAS_DEBUG_VIRTUAL 13 select ARCH_HAS_DEVMEM_IS_ALLOWED 14 select ARCH_HAS_DMA_COHERENT_TO_PFN 15 select ARCH_HAS_DMA_MMAP_PGPROT 16 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 17 select ARCH_HAS_ELF_RANDOMIZE 18 select ARCH_HAS_FAST_MULTIPLIER 19 select ARCH_HAS_FORTIFY_SOURCE 20 select ARCH_HAS_GCOV_PROFILE_ALL 21 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 22 select ARCH_HAS_KCOV 23 select ARCH_HAS_MEMBARRIER_SYNC_CORE 24 select ARCH_HAS_PTE_SPECIAL 25 select ARCH_HAS_SETUP_DMA_OPS 26 select ARCH_HAS_SET_MEMORY 27 select ARCH_HAS_STRICT_KERNEL_RWX 28 select ARCH_HAS_STRICT_MODULE_RWX 29 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 30 select ARCH_HAS_SYNC_DMA_FOR_CPU 31 select ARCH_HAS_SYSCALL_WRAPPER 32 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 33 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 34 select ARCH_HAVE_NMI_SAFE_CMPXCHG 35 select ARCH_INLINE_READ_LOCK if !PREEMPT 36 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT 37 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT 38 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT 39 select ARCH_INLINE_READ_UNLOCK if !PREEMPT 40 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT 41 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT 42 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT 43 select ARCH_INLINE_WRITE_LOCK if !PREEMPT 44 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT 45 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT 46 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT 47 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT 48 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT 49 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT 50 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT 51 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT 52 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT 53 select ARCH_INLINE_SPIN_LOCK if !PREEMPT 54 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT 55 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT 56 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT 57 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT 58 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT 59 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT 60 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT 61 select ARCH_USE_CMPXCHG_LOCKREF 62 select ARCH_USE_QUEUED_RWLOCKS 63 select ARCH_USE_QUEUED_SPINLOCKS 64 select ARCH_SUPPORTS_MEMORY_FAILURE 65 select ARCH_SUPPORTS_ATOMIC_RMW 66 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG 67 select ARCH_SUPPORTS_NUMA_BALANCING 68 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 69 select ARCH_WANT_FRAME_POINTERS 70 select ARCH_HAS_UBSAN_SANITIZE_ALL 71 select ARM_AMBA 72 select ARM_ARCH_TIMER 73 select ARM_GIC 74 select AUDIT_ARCH_COMPAT_GENERIC 75 select ARM_GIC_V2M if PCI 76 select ARM_GIC_V3 77 select ARM_GIC_V3_ITS if PCI 78 select ARM_PSCI_FW 79 select BUILDTIME_EXTABLE_SORT 80 select CLONE_BACKWARDS 81 select COMMON_CLK 82 select CPU_PM if (SUSPEND || CPU_IDLE) 83 select CRC32 84 select DCACHE_WORD_ACCESS 85 select DMA_DIRECT_REMAP 86 select EDAC_SUPPORT 87 select FRAME_POINTER 88 select GENERIC_ALLOCATOR 89 select GENERIC_ARCH_TOPOLOGY 90 select GENERIC_CLOCKEVENTS 91 select GENERIC_CLOCKEVENTS_BROADCAST 92 select GENERIC_CPU_AUTOPROBE 93 select GENERIC_EARLY_IOREMAP 94 select GENERIC_IDLE_POLL_SETUP 95 select GENERIC_IRQ_MULTI_HANDLER 96 select GENERIC_IRQ_PROBE 97 select GENERIC_IRQ_SHOW 98 select GENERIC_IRQ_SHOW_LEVEL 99 select GENERIC_PCI_IOMAP 100 select GENERIC_SCHED_CLOCK 101 select GENERIC_SMP_IDLE_THREAD 102 select GENERIC_STRNCPY_FROM_USER 103 select GENERIC_STRNLEN_USER 104 select GENERIC_TIME_VSYSCALL 105 select HANDLE_DOMAIN_IRQ 106 select HARDIRQS_SW_RESEND 107 select HAVE_PCI 108 select HAVE_ACPI_APEI if (ACPI && EFI) 109 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 110 select HAVE_ARCH_AUDITSYSCALL 111 select HAVE_ARCH_BITREVERSE 112 select HAVE_ARCH_HUGE_VMAP 113 select HAVE_ARCH_JUMP_LABEL 114 select HAVE_ARCH_JUMP_LABEL_RELATIVE 115 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 116 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 117 select HAVE_ARCH_KGDB 118 select HAVE_ARCH_MMAP_RND_BITS 119 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 120 select HAVE_ARCH_PREL32_RELOCATIONS 121 select HAVE_ARCH_SECCOMP_FILTER 122 select HAVE_ARCH_STACKLEAK 123 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 124 select HAVE_ARCH_TRACEHOOK 125 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 126 select HAVE_ARCH_VMAP_STACK 127 select HAVE_ARM_SMCCC 128 select HAVE_EBPF_JIT 129 select HAVE_C_RECORDMCOUNT 130 select HAVE_CMPXCHG_DOUBLE 131 select HAVE_CMPXCHG_LOCAL 132 select HAVE_CONTEXT_TRACKING 133 select HAVE_DEBUG_BUGVERBOSE 134 select HAVE_DEBUG_KMEMLEAK 135 select HAVE_DMA_CONTIGUOUS 136 select HAVE_DYNAMIC_FTRACE 137 select HAVE_EFFICIENT_UNALIGNED_ACCESS 138 select HAVE_FTRACE_MCOUNT_RECORD 139 select HAVE_FUNCTION_TRACER 140 select HAVE_FUNCTION_GRAPH_TRACER 141 select HAVE_GCC_PLUGINS 142 select HAVE_HW_BREAKPOINT if PERF_EVENTS 143 select HAVE_IRQ_TIME_ACCOUNTING 144 select HAVE_MEMBLOCK_NODE_MAP if NUMA 145 select HAVE_NMI 146 select HAVE_PATA_PLATFORM 147 select HAVE_PERF_EVENTS 148 select HAVE_PERF_REGS 149 select HAVE_PERF_USER_STACK_DUMP 150 select HAVE_REGS_AND_STACK_ACCESS_API 151 select HAVE_RCU_TABLE_FREE 152 select HAVE_RCU_TABLE_INVALIDATE 153 select HAVE_RSEQ 154 select HAVE_STACKPROTECTOR 155 select HAVE_SYSCALL_TRACEPOINTS 156 select HAVE_KPROBES 157 select HAVE_KRETPROBES 158 select IOMMU_DMA if IOMMU_SUPPORT 159 select IRQ_DOMAIN 160 select IRQ_FORCED_THREADING 161 select MODULES_USE_ELF_RELA 162 select NEED_DMA_MAP_STATE 163 select NEED_SG_DMA_LENGTH 164 select OF 165 select OF_EARLY_FLATTREE 166 select PCI_DOMAINS_GENERIC if PCI 167 select PCI_ECAM if (ACPI && PCI) 168 select PCI_SYSCALL if PCI 169 select POWER_RESET 170 select POWER_SUPPLY 171 select REFCOUNT_FULL 172 select SPARSE_IRQ 173 select SWIOTLB 174 select SYSCTL_EXCEPTION_TRACE 175 select THREAD_INFO_IN_TASK 176 help 177 ARM 64-bit (AArch64) Linux support. 178 179config 64BIT 180 def_bool y 181 182config MMU 183 def_bool y 184 185config ARM64_PAGE_SHIFT 186 int 187 default 16 if ARM64_64K_PAGES 188 default 14 if ARM64_16K_PAGES 189 default 12 190 191config ARM64_CONT_SHIFT 192 int 193 default 5 if ARM64_64K_PAGES 194 default 7 if ARM64_16K_PAGES 195 default 4 196 197config ARCH_MMAP_RND_BITS_MIN 198 default 14 if ARM64_64K_PAGES 199 default 16 if ARM64_16K_PAGES 200 default 18 201 202# max bits determined by the following formula: 203# VA_BITS - PAGE_SHIFT - 3 204config ARCH_MMAP_RND_BITS_MAX 205 default 19 if ARM64_VA_BITS=36 206 default 24 if ARM64_VA_BITS=39 207 default 27 if ARM64_VA_BITS=42 208 default 30 if ARM64_VA_BITS=47 209 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 210 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 211 default 33 if ARM64_VA_BITS=48 212 default 14 if ARM64_64K_PAGES 213 default 16 if ARM64_16K_PAGES 214 default 18 215 216config ARCH_MMAP_RND_COMPAT_BITS_MIN 217 default 7 if ARM64_64K_PAGES 218 default 9 if ARM64_16K_PAGES 219 default 11 220 221config ARCH_MMAP_RND_COMPAT_BITS_MAX 222 default 16 223 224config NO_IOPORT_MAP 225 def_bool y if !PCI 226 227config STACKTRACE_SUPPORT 228 def_bool y 229 230config ILLEGAL_POINTER_VALUE 231 hex 232 default 0xdead000000000000 233 234config LOCKDEP_SUPPORT 235 def_bool y 236 237config TRACE_IRQFLAGS_SUPPORT 238 def_bool y 239 240config RWSEM_XCHGADD_ALGORITHM 241 def_bool y 242 243config GENERIC_BUG 244 def_bool y 245 depends on BUG 246 247config GENERIC_BUG_RELATIVE_POINTERS 248 def_bool y 249 depends on GENERIC_BUG 250 251config GENERIC_HWEIGHT 252 def_bool y 253 254config GENERIC_CSUM 255 def_bool y 256 257config GENERIC_CALIBRATE_DELAY 258 def_bool y 259 260config ZONE_DMA32 261 def_bool y 262 263config HAVE_GENERIC_GUP 264 def_bool y 265 266config ARCH_ENABLE_MEMORY_HOTPLUG 267 def_bool y 268 269config SMP 270 def_bool y 271 272config KERNEL_MODE_NEON 273 def_bool y 274 275config FIX_EARLYCON_MEM 276 def_bool y 277 278config PGTABLE_LEVELS 279 int 280 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 281 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 282 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52) 283 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 284 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 285 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 286 287config ARCH_SUPPORTS_UPROBES 288 def_bool y 289 290config ARCH_PROC_KCORE_TEXT 291 def_bool y 292 293source "arch/arm64/Kconfig.platforms" 294 295menu "Kernel Features" 296 297menu "ARM errata workarounds via the alternatives framework" 298 299config ARM64_WORKAROUND_CLEAN_CACHE 300 def_bool n 301 302config ARM64_ERRATUM_826319 303 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 304 default y 305 select ARM64_WORKAROUND_CLEAN_CACHE 306 help 307 This option adds an alternative code sequence to work around ARM 308 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 309 AXI master interface and an L2 cache. 310 311 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 312 and is unable to accept a certain write via this interface, it will 313 not progress on read data presented on the read data channel and the 314 system can deadlock. 315 316 The workaround promotes data cache clean instructions to 317 data cache clean-and-invalidate. 318 Please note that this does not necessarily enable the workaround, 319 as it depends on the alternative framework, which will only patch 320 the kernel if an affected CPU is detected. 321 322 If unsure, say Y. 323 324config ARM64_ERRATUM_827319 325 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 326 default y 327 select ARM64_WORKAROUND_CLEAN_CACHE 328 help 329 This option adds an alternative code sequence to work around ARM 330 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 331 master interface and an L2 cache. 332 333 Under certain conditions this erratum can cause a clean line eviction 334 to occur at the same time as another transaction to the same address 335 on the AMBA 5 CHI interface, which can cause data corruption if the 336 interconnect reorders the two transactions. 337 338 The workaround promotes data cache clean instructions to 339 data cache clean-and-invalidate. 340 Please note that this does not necessarily enable the workaround, 341 as it depends on the alternative framework, which will only patch 342 the kernel if an affected CPU is detected. 343 344 If unsure, say Y. 345 346config ARM64_ERRATUM_824069 347 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 348 default y 349 select ARM64_WORKAROUND_CLEAN_CACHE 350 help 351 This option adds an alternative code sequence to work around ARM 352 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 353 to a coherent interconnect. 354 355 If a Cortex-A53 processor is executing a store or prefetch for 356 write instruction at the same time as a processor in another 357 cluster is executing a cache maintenance operation to the same 358 address, then this erratum might cause a clean cache line to be 359 incorrectly marked as dirty. 360 361 The workaround promotes data cache clean instructions to 362 data cache clean-and-invalidate. 363 Please note that this option does not necessarily enable the 364 workaround, as it depends on the alternative framework, which will 365 only patch the kernel if an affected CPU is detected. 366 367 If unsure, say Y. 368 369config ARM64_ERRATUM_819472 370 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 371 default y 372 select ARM64_WORKAROUND_CLEAN_CACHE 373 help 374 This option adds an alternative code sequence to work around ARM 375 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 376 present when it is connected to a coherent interconnect. 377 378 If the processor is executing a load and store exclusive sequence at 379 the same time as a processor in another cluster is executing a cache 380 maintenance operation to the same address, then this erratum might 381 cause data corruption. 382 383 The workaround promotes data cache clean instructions to 384 data cache clean-and-invalidate. 385 Please note that this does not necessarily enable the workaround, 386 as it depends on the alternative framework, which will only patch 387 the kernel if an affected CPU is detected. 388 389 If unsure, say Y. 390 391config ARM64_ERRATUM_832075 392 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 393 default y 394 help 395 This option adds an alternative code sequence to work around ARM 396 erratum 832075 on Cortex-A57 parts up to r1p2. 397 398 Affected Cortex-A57 parts might deadlock when exclusive load/store 399 instructions to Write-Back memory are mixed with Device loads. 400 401 The workaround is to promote device loads to use Load-Acquire 402 semantics. 403 Please note that this does not necessarily enable the workaround, 404 as it depends on the alternative framework, which will only patch 405 the kernel if an affected CPU is detected. 406 407 If unsure, say Y. 408 409config ARM64_ERRATUM_834220 410 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 411 depends on KVM 412 default y 413 help 414 This option adds an alternative code sequence to work around ARM 415 erratum 834220 on Cortex-A57 parts up to r1p2. 416 417 Affected Cortex-A57 parts might report a Stage 2 translation 418 fault as the result of a Stage 1 fault for load crossing a 419 page boundary when there is a permission or device memory 420 alignment fault at Stage 1 and a translation fault at Stage 2. 421 422 The workaround is to verify that the Stage 1 translation 423 doesn't generate a fault before handling the Stage 2 fault. 424 Please note that this does not necessarily enable the workaround, 425 as it depends on the alternative framework, which will only patch 426 the kernel if an affected CPU is detected. 427 428 If unsure, say Y. 429 430config ARM64_ERRATUM_845719 431 bool "Cortex-A53: 845719: a load might read incorrect data" 432 depends on COMPAT 433 default y 434 help 435 This option adds an alternative code sequence to work around ARM 436 erratum 845719 on Cortex-A53 parts up to r0p4. 437 438 When running a compat (AArch32) userspace on an affected Cortex-A53 439 part, a load at EL0 from a virtual address that matches the bottom 32 440 bits of the virtual address used by a recent load at (AArch64) EL1 441 might return incorrect data. 442 443 The workaround is to write the contextidr_el1 register on exception 444 return to a 32-bit task. 445 Please note that this does not necessarily enable the workaround, 446 as it depends on the alternative framework, which will only patch 447 the kernel if an affected CPU is detected. 448 449 If unsure, say Y. 450 451config ARM64_ERRATUM_843419 452 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 453 default y 454 select ARM64_MODULE_PLTS if MODULES 455 help 456 This option links the kernel with '--fix-cortex-a53-843419' and 457 enables PLT support to replace certain ADRP instructions, which can 458 cause subsequent memory accesses to use an incorrect address on 459 Cortex-A53 parts up to r0p4. 460 461 If unsure, say Y. 462 463config ARM64_ERRATUM_1024718 464 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 465 default y 466 help 467 This option adds work around for Arm Cortex-A55 Erratum 1024718. 468 469 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 470 update of the hardware dirty bit when the DBM/AP bits are updated 471 without a break-before-make. The work around is to disable the usage 472 of hardware DBM locally on the affected cores. CPUs not affected by 473 erratum will continue to use the feature. 474 475 If unsure, say Y. 476 477config ARM64_ERRATUM_1188873 478 bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 479 default y 480 select ARM_ARCH_TIMER_OOL_WORKAROUND 481 help 482 This option adds work arounds for ARM Cortex-A76 erratum 1188873 483 484 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause 485 register corruption when accessing the timer registers from 486 AArch32 userspace. 487 488 If unsure, say Y. 489 490config ARM64_ERRATUM_1165522 491 bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 492 default y 493 help 494 This option adds work arounds for ARM Cortex-A76 erratum 1165522 495 496 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 497 corrupted TLBs by speculating an AT instruction during a guest 498 context switch. 499 500 If unsure, say Y. 501 502config ARM64_ERRATUM_1286807 503 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 504 default y 505 select ARM64_WORKAROUND_REPEAT_TLBI 506 help 507 This option adds workaround for ARM Cortex-A76 erratum 1286807 508 509 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 510 address for a cacheable mapping of a location is being 511 accessed by a core while another core is remapping the virtual 512 address to a new physical page using the recommended 513 break-before-make sequence, then under very rare circumstances 514 TLBI+DSB completes before a read using the translation being 515 invalidated has been observed by other observers. The 516 workaround repeats the TLBI+DSB operation. 517 518 If unsure, say Y. 519 520config CAVIUM_ERRATUM_22375 521 bool "Cavium erratum 22375, 24313" 522 default y 523 help 524 Enable workaround for erratum 22375, 24313. 525 526 This implements two gicv3-its errata workarounds for ThunderX. Both 527 with small impact affecting only ITS table allocation. 528 529 erratum 22375: only alloc 8MB table size 530 erratum 24313: ignore memory access type 531 532 The fixes are in ITS initialization and basically ignore memory access 533 type and table size provided by the TYPER and BASER registers. 534 535 If unsure, say Y. 536 537config CAVIUM_ERRATUM_23144 538 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 539 depends on NUMA 540 default y 541 help 542 ITS SYNC command hang for cross node io and collections/cpu mapping. 543 544 If unsure, say Y. 545 546config CAVIUM_ERRATUM_23154 547 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 548 default y 549 help 550 The gicv3 of ThunderX requires a modified version for 551 reading the IAR status to ensure data synchronization 552 (access to icc_iar1_el1 is not sync'ed before and after). 553 554 If unsure, say Y. 555 556config CAVIUM_ERRATUM_27456 557 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 558 default y 559 help 560 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 561 instructions may cause the icache to become corrupted if it 562 contains data for a non-current ASID. The fix is to 563 invalidate the icache when changing the mm context. 564 565 If unsure, say Y. 566 567config CAVIUM_ERRATUM_30115 568 bool "Cavium erratum 30115: Guest may disable interrupts in host" 569 default y 570 help 571 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 572 1.2, and T83 Pass 1.0, KVM guest execution may disable 573 interrupts in host. Trapping both GICv3 group-0 and group-1 574 accesses sidesteps the issue. 575 576 If unsure, say Y. 577 578config QCOM_FALKOR_ERRATUM_1003 579 bool "Falkor E1003: Incorrect translation due to ASID change" 580 default y 581 help 582 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 583 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 584 in TTBR1_EL1, this situation only occurs in the entry trampoline and 585 then only for entries in the walk cache, since the leaf translation 586 is unchanged. Work around the erratum by invalidating the walk cache 587 entries for the trampoline before entering the kernel proper. 588 589config ARM64_WORKAROUND_REPEAT_TLBI 590 bool 591 help 592 Enable the repeat TLBI workaround for Falkor erratum 1009 and 593 Cortex-A76 erratum 1286807. 594 595config QCOM_FALKOR_ERRATUM_1009 596 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 597 default y 598 select ARM64_WORKAROUND_REPEAT_TLBI 599 help 600 On Falkor v1, the CPU may prematurely complete a DSB following a 601 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 602 one more time to fix the issue. 603 604 If unsure, say Y. 605 606config QCOM_QDF2400_ERRATUM_0065 607 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 608 default y 609 help 610 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 611 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 612 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 613 614 If unsure, say Y. 615 616config SOCIONEXT_SYNQUACER_PREITS 617 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 618 default y 619 help 620 Socionext Synquacer SoCs implement a separate h/w block to generate 621 MSI doorbell writes with non-zero values for the device ID. 622 623 If unsure, say Y. 624 625config HISILICON_ERRATUM_161600802 626 bool "Hip07 161600802: Erroneous redistributor VLPI base" 627 default y 628 help 629 The HiSilicon Hip07 SoC usees the wrong redistributor base 630 when issued ITS commands such as VMOVP and VMAPP, and requires 631 a 128kB offset to be applied to the target address in this commands. 632 633 If unsure, say Y. 634 635config QCOM_FALKOR_ERRATUM_E1041 636 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 637 default y 638 help 639 Falkor CPU may speculatively fetch instructions from an improper 640 memory location when MMU translation is changed from SCTLR_ELn[M]=1 641 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 642 643 If unsure, say Y. 644 645config FUJITSU_ERRATUM_010001 646 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 647 default y 648 help 649 This option adds workaround for Fujitsu-A64FX erratum E#010001. 650 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 651 accesses may cause undefined fault (Data abort, DFSC=0b111111). 652 This fault occurs under a specific hardware condition when a 653 load/store instruction performs an address translation using: 654 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 655 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 656 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 657 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 658 659 The workaround is to ensure these bits are clear in TCR_ELx. 660 The workaround only affect the Fujitsu-A64FX. 661 662 If unsure, say Y. 663 664endmenu 665 666 667choice 668 prompt "Page size" 669 default ARM64_4K_PAGES 670 help 671 Page size (translation granule) configuration. 672 673config ARM64_4K_PAGES 674 bool "4KB" 675 help 676 This feature enables 4KB pages support. 677 678config ARM64_16K_PAGES 679 bool "16KB" 680 help 681 The system will use 16KB pages support. AArch32 emulation 682 requires applications compiled with 16K (or a multiple of 16K) 683 aligned segments. 684 685config ARM64_64K_PAGES 686 bool "64KB" 687 help 688 This feature enables 64KB pages support (4KB by default) 689 allowing only two levels of page tables and faster TLB 690 look-up. AArch32 emulation requires applications compiled 691 with 64K aligned segments. 692 693endchoice 694 695choice 696 prompt "Virtual address space size" 697 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 698 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 699 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 700 help 701 Allows choosing one of multiple possible virtual address 702 space sizes. The level of translation table is determined by 703 a combination of page size and virtual address space size. 704 705config ARM64_VA_BITS_36 706 bool "36-bit" if EXPERT 707 depends on ARM64_16K_PAGES 708 709config ARM64_VA_BITS_39 710 bool "39-bit" 711 depends on ARM64_4K_PAGES 712 713config ARM64_VA_BITS_42 714 bool "42-bit" 715 depends on ARM64_64K_PAGES 716 717config ARM64_VA_BITS_47 718 bool "47-bit" 719 depends on ARM64_16K_PAGES 720 721config ARM64_VA_BITS_48 722 bool "48-bit" 723 724config ARM64_USER_VA_BITS_52 725 bool "52-bit (user)" 726 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 727 help 728 Enable 52-bit virtual addressing for userspace when explicitly 729 requested via a hint to mmap(). The kernel will continue to 730 use 48-bit virtual addresses for its own mappings. 731 732 NOTE: Enabling 52-bit virtual addressing in conjunction with 733 ARMv8.3 Pointer Authentication will result in the PAC being 734 reduced from 7 bits to 3 bits, which may have a significant 735 impact on its susceptibility to brute-force attacks. 736 737 If unsure, select 48-bit virtual addressing instead. 738 739endchoice 740 741config ARM64_FORCE_52BIT 742 bool "Force 52-bit virtual addresses for userspace" 743 depends on ARM64_USER_VA_BITS_52 && EXPERT 744 help 745 For systems with 52-bit userspace VAs enabled, the kernel will attempt 746 to maintain compatibility with older software by providing 48-bit VAs 747 unless a hint is supplied to mmap. 748 749 This configuration option disables the 48-bit compatibility logic, and 750 forces all userspace addresses to be 52-bit on HW that supports it. One 751 should only enable this configuration option for stress testing userspace 752 memory management code. If unsure say N here. 753 754config ARM64_VA_BITS 755 int 756 default 36 if ARM64_VA_BITS_36 757 default 39 if ARM64_VA_BITS_39 758 default 42 if ARM64_VA_BITS_42 759 default 47 if ARM64_VA_BITS_47 760 default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52 761 762choice 763 prompt "Physical address space size" 764 default ARM64_PA_BITS_48 765 help 766 Choose the maximum physical address range that the kernel will 767 support. 768 769config ARM64_PA_BITS_48 770 bool "48-bit" 771 772config ARM64_PA_BITS_52 773 bool "52-bit (ARMv8.2)" 774 depends on ARM64_64K_PAGES 775 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 776 help 777 Enable support for a 52-bit physical address space, introduced as 778 part of the ARMv8.2-LPA extension. 779 780 With this enabled, the kernel will also continue to work on CPUs that 781 do not support ARMv8.2-LPA, but with some added memory overhead (and 782 minor performance overhead). 783 784endchoice 785 786config ARM64_PA_BITS 787 int 788 default 48 if ARM64_PA_BITS_48 789 default 52 if ARM64_PA_BITS_52 790 791config CPU_BIG_ENDIAN 792 bool "Build big-endian kernel" 793 help 794 Say Y if you plan on running a kernel in big-endian mode. 795 796config SCHED_MC 797 bool "Multi-core scheduler support" 798 help 799 Multi-core scheduler support improves the CPU scheduler's decision 800 making when dealing with multi-core CPU chips at a cost of slightly 801 increased overhead in some places. If unsure say N here. 802 803config SCHED_SMT 804 bool "SMT scheduler support" 805 help 806 Improves the CPU scheduler's decision making when dealing with 807 MultiThreading at a cost of slightly increased overhead in some 808 places. If unsure say N here. 809 810config NR_CPUS 811 int "Maximum number of CPUs (2-4096)" 812 range 2 4096 813 default "256" 814 815config HOTPLUG_CPU 816 bool "Support for hot-pluggable CPUs" 817 select GENERIC_IRQ_MIGRATION 818 help 819 Say Y here to experiment with turning CPUs off and on. CPUs 820 can be controlled through /sys/devices/system/cpu. 821 822# Common NUMA Features 823config NUMA 824 bool "Numa Memory Allocation and Scheduler Support" 825 select ACPI_NUMA if ACPI 826 select OF_NUMA 827 help 828 Enable NUMA (Non Uniform Memory Access) support. 829 830 The kernel will try to allocate memory used by a CPU on the 831 local memory of the CPU and add some more 832 NUMA awareness to the kernel. 833 834config NODES_SHIFT 835 int "Maximum NUMA Nodes (as a power of 2)" 836 range 1 10 837 default "2" 838 depends on NEED_MULTIPLE_NODES 839 help 840 Specify the maximum number of NUMA Nodes available on the target 841 system. Increases memory reserved to accommodate various tables. 842 843config USE_PERCPU_NUMA_NODE_ID 844 def_bool y 845 depends on NUMA 846 847config HAVE_SETUP_PER_CPU_AREA 848 def_bool y 849 depends on NUMA 850 851config NEED_PER_CPU_EMBED_FIRST_CHUNK 852 def_bool y 853 depends on NUMA 854 855config HOLES_IN_ZONE 856 def_bool y 857 858source "kernel/Kconfig.hz" 859 860config ARCH_SUPPORTS_DEBUG_PAGEALLOC 861 def_bool y 862 863config ARCH_SPARSEMEM_ENABLE 864 def_bool y 865 select SPARSEMEM_VMEMMAP_ENABLE 866 867config ARCH_SPARSEMEM_DEFAULT 868 def_bool ARCH_SPARSEMEM_ENABLE 869 870config ARCH_SELECT_MEMORY_MODEL 871 def_bool ARCH_SPARSEMEM_ENABLE 872 873config ARCH_FLATMEM_ENABLE 874 def_bool !NUMA 875 876config HAVE_ARCH_PFN_VALID 877 def_bool y 878 879config HW_PERF_EVENTS 880 def_bool y 881 depends on ARM_PMU 882 883config SYS_SUPPORTS_HUGETLBFS 884 def_bool y 885 886config ARCH_WANT_HUGE_PMD_SHARE 887 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 888 889config ARCH_HAS_CACHE_LINE_SIZE 890 def_bool y 891 892config SECCOMP 893 bool "Enable seccomp to safely compute untrusted bytecode" 894 ---help--- 895 This kernel feature is useful for number crunching applications 896 that may need to compute untrusted bytecode during their 897 execution. By using pipes or other transports made available to 898 the process as file descriptors supporting the read/write 899 syscalls, it's possible to isolate those applications in 900 their own address space using seccomp. Once seccomp is 901 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 902 and the task is only allowed to execute a few safe syscalls 903 defined by each seccomp mode. 904 905config PARAVIRT 906 bool "Enable paravirtualization code" 907 help 908 This changes the kernel so it can modify itself when it is run 909 under a hypervisor, potentially improving performance significantly 910 over full virtualization. 911 912config PARAVIRT_TIME_ACCOUNTING 913 bool "Paravirtual steal time accounting" 914 select PARAVIRT 915 default n 916 help 917 Select this option to enable fine granularity task steal time 918 accounting. Time spent executing other tasks in parallel with 919 the current vCPU is discounted from the vCPU power. To account for 920 that, there can be a small performance impact. 921 922 If in doubt, say N here. 923 924config KEXEC 925 depends on PM_SLEEP_SMP 926 select KEXEC_CORE 927 bool "kexec system call" 928 ---help--- 929 kexec is a system call that implements the ability to shutdown your 930 current kernel, and to start another kernel. It is like a reboot 931 but it is independent of the system firmware. And like a reboot 932 you can start any kernel with it, not just Linux. 933 934config KEXEC_FILE 935 bool "kexec file based system call" 936 select KEXEC_CORE 937 help 938 This is new version of kexec system call. This system call is 939 file based and takes file descriptors as system call argument 940 for kernel and initramfs as opposed to list of segments as 941 accepted by previous system call. 942 943config KEXEC_VERIFY_SIG 944 bool "Verify kernel signature during kexec_file_load() syscall" 945 depends on KEXEC_FILE 946 help 947 Select this option to verify a signature with loaded kernel 948 image. If configured, any attempt of loading a image without 949 valid signature will fail. 950 951 In addition to that option, you need to enable signature 952 verification for the corresponding kernel image type being 953 loaded in order for this to work. 954 955config KEXEC_IMAGE_VERIFY_SIG 956 bool "Enable Image signature verification support" 957 default y 958 depends on KEXEC_VERIFY_SIG 959 depends on EFI && SIGNED_PE_FILE_VERIFICATION 960 help 961 Enable Image signature verification support. 962 963comment "Support for PE file signature verification disabled" 964 depends on KEXEC_VERIFY_SIG 965 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 966 967config CRASH_DUMP 968 bool "Build kdump crash kernel" 969 help 970 Generate crash dump after being started by kexec. This should 971 be normally only set in special crash dump kernels which are 972 loaded in the main kernel with kexec-tools into a specially 973 reserved region and then later executed after a crash by 974 kdump/kexec. 975 976 For more details see Documentation/kdump/kdump.txt 977 978config XEN_DOM0 979 def_bool y 980 depends on XEN 981 982config XEN 983 bool "Xen guest support on ARM64" 984 depends on ARM64 && OF 985 select SWIOTLB_XEN 986 select PARAVIRT 987 help 988 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 989 990config FORCE_MAX_ZONEORDER 991 int 992 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 993 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 994 default "11" 995 help 996 The kernel memory allocator divides physically contiguous memory 997 blocks into "zones", where each zone is a power of two number of 998 pages. This option selects the largest power of two that the kernel 999 keeps in the memory allocator. If you need to allocate very large 1000 blocks of physically contiguous memory, then you may need to 1001 increase this value. 1002 1003 This config option is actually maximum order plus one. For example, 1004 a value of 11 means that the largest free memory block is 2^10 pages. 1005 1006 We make sure that we can allocate upto a HugePage size for each configuration. 1007 Hence we have : 1008 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1009 1010 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1011 4M allocations matching the default size used by generic code. 1012 1013config UNMAP_KERNEL_AT_EL0 1014 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1015 default y 1016 help 1017 Speculation attacks against some high-performance processors can 1018 be used to bypass MMU permission checks and leak kernel data to 1019 userspace. This can be defended against by unmapping the kernel 1020 when running in userspace, mapping it back in on exception entry 1021 via a trampoline page in the vector table. 1022 1023 If unsure, say Y. 1024 1025config HARDEN_BRANCH_PREDICTOR 1026 bool "Harden the branch predictor against aliasing attacks" if EXPERT 1027 default y 1028 help 1029 Speculation attacks against some high-performance processors rely on 1030 being able to manipulate the branch predictor for a victim context by 1031 executing aliasing branches in the attacker context. Such attacks 1032 can be partially mitigated against by clearing internal branch 1033 predictor state and limiting the prediction logic in some situations. 1034 1035 This config option will take CPU-specific actions to harden the 1036 branch predictor against aliasing attacks and may rely on specific 1037 instruction sequences or control bits being set by the system 1038 firmware. 1039 1040 If unsure, say Y. 1041 1042config HARDEN_EL2_VECTORS 1043 bool "Harden EL2 vector mapping against system register leak" if EXPERT 1044 default y 1045 help 1046 Speculation attacks against some high-performance processors can 1047 be used to leak privileged information such as the vector base 1048 register, resulting in a potential defeat of the EL2 layout 1049 randomization. 1050 1051 This config option will map the vectors to a fixed location, 1052 independent of the EL2 code mapping, so that revealing VBAR_EL2 1053 to an attacker does not give away any extra information. This 1054 only gets enabled on affected CPUs. 1055 1056 If unsure, say Y. 1057 1058config ARM64_SSBD 1059 bool "Speculative Store Bypass Disable" if EXPERT 1060 default y 1061 help 1062 This enables mitigation of the bypassing of previous stores 1063 by speculative loads. 1064 1065 If unsure, say Y. 1066 1067config RODATA_FULL_DEFAULT_ENABLED 1068 bool "Apply r/o permissions of VM areas also to their linear aliases" 1069 default y 1070 help 1071 Apply read-only attributes of VM areas to the linear alias of 1072 the backing pages as well. This prevents code or read-only data 1073 from being modified (inadvertently or intentionally) via another 1074 mapping of the same memory page. This additional enhancement can 1075 be turned off at runtime by passing rodata=[off|on] (and turned on 1076 with rodata=full if this option is set to 'n') 1077 1078 This requires the linear region to be mapped down to pages, 1079 which may adversely affect performance in some cases. 1080 1081menuconfig ARMV8_DEPRECATED 1082 bool "Emulate deprecated/obsolete ARMv8 instructions" 1083 depends on COMPAT 1084 depends on SYSCTL 1085 help 1086 Legacy software support may require certain instructions 1087 that have been deprecated or obsoleted in the architecture. 1088 1089 Enable this config to enable selective emulation of these 1090 features. 1091 1092 If unsure, say Y 1093 1094if ARMV8_DEPRECATED 1095 1096config SWP_EMULATION 1097 bool "Emulate SWP/SWPB instructions" 1098 help 1099 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1100 they are always undefined. Say Y here to enable software 1101 emulation of these instructions for userspace using LDXR/STXR. 1102 1103 In some older versions of glibc [<=2.8] SWP is used during futex 1104 trylock() operations with the assumption that the code will not 1105 be preempted. This invalid assumption may be more likely to fail 1106 with SWP emulation enabled, leading to deadlock of the user 1107 application. 1108 1109 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1110 on an external transaction monitoring block called a global 1111 monitor to maintain update atomicity. If your system does not 1112 implement a global monitor, this option can cause programs that 1113 perform SWP operations to uncached memory to deadlock. 1114 1115 If unsure, say Y 1116 1117config CP15_BARRIER_EMULATION 1118 bool "Emulate CP15 Barrier instructions" 1119 help 1120 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1121 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1122 strongly recommended to use the ISB, DSB, and DMB 1123 instructions instead. 1124 1125 Say Y here to enable software emulation of these 1126 instructions for AArch32 userspace code. When this option is 1127 enabled, CP15 barrier usage is traced which can help 1128 identify software that needs updating. 1129 1130 If unsure, say Y 1131 1132config SETEND_EMULATION 1133 bool "Emulate SETEND instruction" 1134 help 1135 The SETEND instruction alters the data-endianness of the 1136 AArch32 EL0, and is deprecated in ARMv8. 1137 1138 Say Y here to enable software emulation of the instruction 1139 for AArch32 userspace code. 1140 1141 Note: All the cpus on the system must have mixed endian support at EL0 1142 for this feature to be enabled. If a new CPU - which doesn't support mixed 1143 endian - is hotplugged in after this feature has been enabled, there could 1144 be unexpected results in the applications. 1145 1146 If unsure, say Y 1147endif 1148 1149config ARM64_SW_TTBR0_PAN 1150 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1151 help 1152 Enabling this option prevents the kernel from accessing 1153 user-space memory directly by pointing TTBR0_EL1 to a reserved 1154 zeroed area and reserved ASID. The user access routines 1155 restore the valid TTBR0_EL1 temporarily. 1156 1157menu "ARMv8.1 architectural features" 1158 1159config ARM64_HW_AFDBM 1160 bool "Support for hardware updates of the Access and Dirty page flags" 1161 default y 1162 help 1163 The ARMv8.1 architecture extensions introduce support for 1164 hardware updates of the access and dirty information in page 1165 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1166 capable processors, accesses to pages with PTE_AF cleared will 1167 set this bit instead of raising an access flag fault. 1168 Similarly, writes to read-only pages with the DBM bit set will 1169 clear the read-only bit (AP[2]) instead of raising a 1170 permission fault. 1171 1172 Kernels built with this configuration option enabled continue 1173 to work on pre-ARMv8.1 hardware and the performance impact is 1174 minimal. If unsure, say Y. 1175 1176config ARM64_PAN 1177 bool "Enable support for Privileged Access Never (PAN)" 1178 default y 1179 help 1180 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1181 prevents the kernel or hypervisor from accessing user-space (EL0) 1182 memory directly. 1183 1184 Choosing this option will cause any unprotected (not using 1185 copy_to_user et al) memory access to fail with a permission fault. 1186 1187 The feature is detected at runtime, and will remain as a 'nop' 1188 instruction if the cpu does not implement the feature. 1189 1190config ARM64_LSE_ATOMICS 1191 bool "Atomic instructions" 1192 default y 1193 help 1194 As part of the Large System Extensions, ARMv8.1 introduces new 1195 atomic instructions that are designed specifically to scale in 1196 very large systems. 1197 1198 Say Y here to make use of these instructions for the in-kernel 1199 atomic routines. This incurs a small overhead on CPUs that do 1200 not support these instructions and requires the kernel to be 1201 built with binutils >= 2.25 in order for the new instructions 1202 to be used. 1203 1204config ARM64_VHE 1205 bool "Enable support for Virtualization Host Extensions (VHE)" 1206 default y 1207 help 1208 Virtualization Host Extensions (VHE) allow the kernel to run 1209 directly at EL2 (instead of EL1) on processors that support 1210 it. This leads to better performance for KVM, as they reduce 1211 the cost of the world switch. 1212 1213 Selecting this option allows the VHE feature to be detected 1214 at runtime, and does not affect processors that do not 1215 implement this feature. 1216 1217endmenu 1218 1219menu "ARMv8.2 architectural features" 1220 1221config ARM64_UAO 1222 bool "Enable support for User Access Override (UAO)" 1223 default y 1224 help 1225 User Access Override (UAO; part of the ARMv8.2 Extensions) 1226 causes the 'unprivileged' variant of the load/store instructions to 1227 be overridden to be privileged. 1228 1229 This option changes get_user() and friends to use the 'unprivileged' 1230 variant of the load/store instructions. This ensures that user-space 1231 really did have access to the supplied memory. When addr_limit is 1232 set to kernel memory the UAO bit will be set, allowing privileged 1233 access to kernel memory. 1234 1235 Choosing this option will cause copy_to_user() et al to use user-space 1236 memory permissions. 1237 1238 The feature is detected at runtime, the kernel will use the 1239 regular load/store instructions if the cpu does not implement the 1240 feature. 1241 1242config ARM64_PMEM 1243 bool "Enable support for persistent memory" 1244 select ARCH_HAS_PMEM_API 1245 select ARCH_HAS_UACCESS_FLUSHCACHE 1246 help 1247 Say Y to enable support for the persistent memory API based on the 1248 ARMv8.2 DCPoP feature. 1249 1250 The feature is detected at runtime, and the kernel will use DC CVAC 1251 operations if DC CVAP is not supported (following the behaviour of 1252 DC CVAP itself if the system does not define a point of persistence). 1253 1254config ARM64_RAS_EXTN 1255 bool "Enable support for RAS CPU Extensions" 1256 default y 1257 help 1258 CPUs that support the Reliability, Availability and Serviceability 1259 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1260 errors, classify them and report them to software. 1261 1262 On CPUs with these extensions system software can use additional 1263 barriers to determine if faults are pending and read the 1264 classification from a new set of registers. 1265 1266 Selecting this feature will allow the kernel to use these barriers 1267 and access the new registers if the system supports the extension. 1268 Platform RAS features may additionally depend on firmware support. 1269 1270config ARM64_CNP 1271 bool "Enable support for Common Not Private (CNP) translations" 1272 default y 1273 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1274 help 1275 Common Not Private (CNP) allows translation table entries to 1276 be shared between different PEs in the same inner shareable 1277 domain, so the hardware can use this fact to optimise the 1278 caching of such entries in the TLB. 1279 1280 Selecting this option allows the CNP feature to be detected 1281 at runtime, and does not affect PEs that do not implement 1282 this feature. 1283 1284endmenu 1285 1286menu "ARMv8.3 architectural features" 1287 1288config ARM64_PTR_AUTH 1289 bool "Enable support for pointer authentication" 1290 default y 1291 help 1292 Pointer authentication (part of the ARMv8.3 Extensions) provides 1293 instructions for signing and authenticating pointers against secret 1294 keys, which can be used to mitigate Return Oriented Programming (ROP) 1295 and other attacks. 1296 1297 This option enables these instructions at EL0 (i.e. for userspace). 1298 1299 Choosing this option will cause the kernel to initialise secret keys 1300 for each process at exec() time, with these keys being 1301 context-switched along with the process. 1302 1303 The feature is detected at runtime. If the feature is not present in 1304 hardware it will not be advertised to userspace nor will it be 1305 enabled. 1306 1307endmenu 1308 1309config ARM64_SVE 1310 bool "ARM Scalable Vector Extension support" 1311 default y 1312 depends on !KVM || ARM64_VHE 1313 help 1314 The Scalable Vector Extension (SVE) is an extension to the AArch64 1315 execution state which complements and extends the SIMD functionality 1316 of the base architecture to support much larger vectors and to enable 1317 additional vectorisation opportunities. 1318 1319 To enable use of this extension on CPUs that implement it, say Y. 1320 1321 Note that for architectural reasons, firmware _must_ implement SVE 1322 support when running on SVE capable hardware. The required support 1323 is present in: 1324 1325 * version 1.5 and later of the ARM Trusted Firmware 1326 * the AArch64 boot wrapper since commit 5e1261e08abf 1327 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1328 1329 For other firmware implementations, consult the firmware documentation 1330 or vendor. 1331 1332 If you need the kernel to boot on SVE-capable hardware with broken 1333 firmware, you may need to say N here until you get your firmware 1334 fixed. Otherwise, you may experience firmware panics or lockups when 1335 booting the kernel. If unsure and you are not observing these 1336 symptoms, you should assume that it is safe to say Y. 1337 1338 CPUs that support SVE are architecturally required to support the 1339 Virtualization Host Extensions (VHE), so the kernel makes no 1340 provision for supporting SVE alongside KVM without VHE enabled. 1341 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1342 KVM in the same kernel image. 1343 1344config ARM64_MODULE_PLTS 1345 bool 1346 select HAVE_MOD_ARCH_SPECIFIC 1347 1348config ARM64_PSEUDO_NMI 1349 bool "Support for NMI-like interrupts" 1350 select CONFIG_ARM_GIC_V3 1351 help 1352 Adds support for mimicking Non-Maskable Interrupts through the use of 1353 GIC interrupt priority. This support requires version 3 or later of 1354 Arm GIC. 1355 1356 This high priority configuration for interrupts needs to be 1357 explicitly enabled by setting the kernel parameter 1358 "irqchip.gicv3_pseudo_nmi" to 1. 1359 1360 If unsure, say N 1361 1362config RELOCATABLE 1363 bool 1364 help 1365 This builds the kernel as a Position Independent Executable (PIE), 1366 which retains all relocation metadata required to relocate the 1367 kernel binary at runtime to a different virtual address than the 1368 address it was linked at. 1369 Since AArch64 uses the RELA relocation format, this requires a 1370 relocation pass at runtime even if the kernel is loaded at the 1371 same address it was linked at. 1372 1373config RANDOMIZE_BASE 1374 bool "Randomize the address of the kernel image" 1375 select ARM64_MODULE_PLTS if MODULES 1376 select RELOCATABLE 1377 help 1378 Randomizes the virtual address at which the kernel image is 1379 loaded, as a security feature that deters exploit attempts 1380 relying on knowledge of the location of kernel internals. 1381 1382 It is the bootloader's job to provide entropy, by passing a 1383 random u64 value in /chosen/kaslr-seed at kernel entry. 1384 1385 When booting via the UEFI stub, it will invoke the firmware's 1386 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1387 to the kernel proper. In addition, it will randomise the physical 1388 location of the kernel Image as well. 1389 1390 If unsure, say N. 1391 1392config RANDOMIZE_MODULE_REGION_FULL 1393 bool "Randomize the module region over a 4 GB range" 1394 depends on RANDOMIZE_BASE 1395 default y 1396 help 1397 Randomizes the location of the module region inside a 4 GB window 1398 covering the core kernel. This way, it is less likely for modules 1399 to leak information about the location of core kernel data structures 1400 but it does imply that function calls between modules and the core 1401 kernel will need to be resolved via veneers in the module PLT. 1402 1403 When this option is not set, the module region will be randomized over 1404 a limited range that contains the [_stext, _etext] interval of the 1405 core kernel, so branch relocations are always in range. 1406 1407config CC_HAVE_STACKPROTECTOR_SYSREG 1408 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1409 1410config STACKPROTECTOR_PER_TASK 1411 def_bool y 1412 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1413 1414endmenu 1415 1416menu "Boot options" 1417 1418config ARM64_ACPI_PARKING_PROTOCOL 1419 bool "Enable support for the ARM64 ACPI parking protocol" 1420 depends on ACPI 1421 help 1422 Enable support for the ARM64 ACPI parking protocol. If disabled 1423 the kernel will not allow booting through the ARM64 ACPI parking 1424 protocol even if the corresponding data is present in the ACPI 1425 MADT table. 1426 1427config CMDLINE 1428 string "Default kernel command string" 1429 default "" 1430 help 1431 Provide a set of default command-line options at build time by 1432 entering them here. As a minimum, you should specify the the 1433 root device (e.g. root=/dev/nfs). 1434 1435config CMDLINE_FORCE 1436 bool "Always use the default kernel command string" 1437 help 1438 Always use the default kernel command string, even if the boot 1439 loader passes other arguments to the kernel. 1440 This is useful if you cannot or don't want to change the 1441 command-line options your boot loader passes to the kernel. 1442 1443config EFI_STUB 1444 bool 1445 1446config EFI 1447 bool "UEFI runtime support" 1448 depends on OF && !CPU_BIG_ENDIAN 1449 depends on KERNEL_MODE_NEON 1450 select ARCH_SUPPORTS_ACPI 1451 select LIBFDT 1452 select UCS2_STRING 1453 select EFI_PARAMS_FROM_FDT 1454 select EFI_RUNTIME_WRAPPERS 1455 select EFI_STUB 1456 select EFI_ARMSTUB 1457 default y 1458 help 1459 This option provides support for runtime services provided 1460 by UEFI firmware (such as non-volatile variables, realtime 1461 clock, and platform reset). A UEFI stub is also provided to 1462 allow the kernel to be booted as an EFI application. This 1463 is only useful on systems that have UEFI firmware. 1464 1465config DMI 1466 bool "Enable support for SMBIOS (DMI) tables" 1467 depends on EFI 1468 default y 1469 help 1470 This enables SMBIOS/DMI feature for systems. 1471 1472 This option is only useful on systems that have UEFI firmware. 1473 However, even with this option, the resultant kernel should 1474 continue to boot on existing non-UEFI platforms. 1475 1476endmenu 1477 1478config COMPAT 1479 bool "Kernel support for 32-bit EL0" 1480 depends on ARM64_4K_PAGES || EXPERT 1481 select COMPAT_BINFMT_ELF if BINFMT_ELF 1482 select HAVE_UID16 1483 select OLD_SIGSUSPEND3 1484 select COMPAT_OLD_SIGACTION 1485 help 1486 This option enables support for a 32-bit EL0 running under a 64-bit 1487 kernel at EL1. AArch32-specific components such as system calls, 1488 the user helper functions, VFP support and the ptrace interface are 1489 handled appropriately by the kernel. 1490 1491 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1492 that you will only be able to execute AArch32 binaries that were compiled 1493 with page size aligned segments. 1494 1495 If you want to execute 32-bit userspace applications, say Y. 1496 1497config SYSVIPC_COMPAT 1498 def_bool y 1499 depends on COMPAT && SYSVIPC 1500 1501config ARCH_ENABLE_HUGEPAGE_MIGRATION 1502 def_bool y 1503 depends on HUGETLB_PAGE && MIGRATION 1504 1505menu "Power management options" 1506 1507source "kernel/power/Kconfig" 1508 1509config ARCH_HIBERNATION_POSSIBLE 1510 def_bool y 1511 depends on CPU_PM 1512 1513config ARCH_HIBERNATION_HEADER 1514 def_bool y 1515 depends on HIBERNATION 1516 1517config ARCH_SUSPEND_POSSIBLE 1518 def_bool y 1519 1520endmenu 1521 1522menu "CPU Power Management" 1523 1524source "drivers/cpuidle/Kconfig" 1525 1526source "drivers/cpufreq/Kconfig" 1527 1528endmenu 1529 1530source "drivers/firmware/Kconfig" 1531 1532source "drivers/acpi/Kconfig" 1533 1534source "arch/arm64/kvm/Kconfig" 1535 1536if CRYPTO 1537source "arch/arm64/crypto/Kconfig" 1538endif 1539