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 MULTI_IRQ_HANDLER 163 select NEED_DMA_MAP_STATE 164 select NEED_SG_DMA_LENGTH 165 select OF 166 select OF_EARLY_FLATTREE 167 select PCI_DOMAINS_GENERIC if PCI 168 select PCI_ECAM if (ACPI && PCI) 169 select PCI_SYSCALL if PCI 170 select POWER_RESET 171 select POWER_SUPPLY 172 select REFCOUNT_FULL 173 select SPARSE_IRQ 174 select SWIOTLB 175 select SYSCTL_EXCEPTION_TRACE 176 select THREAD_INFO_IN_TASK 177 help 178 ARM 64-bit (AArch64) Linux support. 179 180config 64BIT 181 def_bool y 182 183config MMU 184 def_bool y 185 186config ARM64_PAGE_SHIFT 187 int 188 default 16 if ARM64_64K_PAGES 189 default 14 if ARM64_16K_PAGES 190 default 12 191 192config ARM64_CONT_SHIFT 193 int 194 default 5 if ARM64_64K_PAGES 195 default 7 if ARM64_16K_PAGES 196 default 4 197 198config ARCH_MMAP_RND_BITS_MIN 199 default 14 if ARM64_64K_PAGES 200 default 16 if ARM64_16K_PAGES 201 default 18 202 203# max bits determined by the following formula: 204# VA_BITS - PAGE_SHIFT - 3 205config ARCH_MMAP_RND_BITS_MAX 206 default 19 if ARM64_VA_BITS=36 207 default 24 if ARM64_VA_BITS=39 208 default 27 if ARM64_VA_BITS=42 209 default 30 if ARM64_VA_BITS=47 210 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 211 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 212 default 33 if ARM64_VA_BITS=48 213 default 14 if ARM64_64K_PAGES 214 default 16 if ARM64_16K_PAGES 215 default 18 216 217config ARCH_MMAP_RND_COMPAT_BITS_MIN 218 default 7 if ARM64_64K_PAGES 219 default 9 if ARM64_16K_PAGES 220 default 11 221 222config ARCH_MMAP_RND_COMPAT_BITS_MAX 223 default 16 224 225config NO_IOPORT_MAP 226 def_bool y if !PCI 227 228config STACKTRACE_SUPPORT 229 def_bool y 230 231config ILLEGAL_POINTER_VALUE 232 hex 233 default 0xdead000000000000 234 235config LOCKDEP_SUPPORT 236 def_bool y 237 238config TRACE_IRQFLAGS_SUPPORT 239 def_bool y 240 241config RWSEM_XCHGADD_ALGORITHM 242 def_bool y 243 244config GENERIC_BUG 245 def_bool y 246 depends on BUG 247 248config GENERIC_BUG_RELATIVE_POINTERS 249 def_bool y 250 depends on GENERIC_BUG 251 252config GENERIC_HWEIGHT 253 def_bool y 254 255config GENERIC_CSUM 256 def_bool y 257 258config GENERIC_CALIBRATE_DELAY 259 def_bool y 260 261config ZONE_DMA32 262 def_bool y 263 264config HAVE_GENERIC_GUP 265 def_bool y 266 267config ARCH_ENABLE_MEMORY_HOTPLUG 268 def_bool y 269 270config SMP 271 def_bool y 272 273config KERNEL_MODE_NEON 274 def_bool y 275 276config FIX_EARLYCON_MEM 277 def_bool y 278 279config PGTABLE_LEVELS 280 int 281 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 282 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 283 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52) 284 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 285 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 286 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 287 288config ARCH_SUPPORTS_UPROBES 289 def_bool y 290 291config ARCH_PROC_KCORE_TEXT 292 def_bool y 293 294source "arch/arm64/Kconfig.platforms" 295 296menu "Kernel Features" 297 298menu "ARM errata workarounds via the alternatives framework" 299 300config ARM64_WORKAROUND_CLEAN_CACHE 301 def_bool n 302 303config ARM64_ERRATUM_826319 304 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 305 default y 306 select ARM64_WORKAROUND_CLEAN_CACHE 307 help 308 This option adds an alternative code sequence to work around ARM 309 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 310 AXI master interface and an L2 cache. 311 312 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 313 and is unable to accept a certain write via this interface, it will 314 not progress on read data presented on the read data channel and the 315 system can deadlock. 316 317 The workaround promotes data cache clean instructions to 318 data cache clean-and-invalidate. 319 Please note that this does not necessarily enable the workaround, 320 as it depends on the alternative framework, which will only patch 321 the kernel if an affected CPU is detected. 322 323 If unsure, say Y. 324 325config ARM64_ERRATUM_827319 326 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 327 default y 328 select ARM64_WORKAROUND_CLEAN_CACHE 329 help 330 This option adds an alternative code sequence to work around ARM 331 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 332 master interface and an L2 cache. 333 334 Under certain conditions this erratum can cause a clean line eviction 335 to occur at the same time as another transaction to the same address 336 on the AMBA 5 CHI interface, which can cause data corruption if the 337 interconnect reorders the two transactions. 338 339 The workaround promotes data cache clean instructions to 340 data cache clean-and-invalidate. 341 Please note that this does not necessarily enable the workaround, 342 as it depends on the alternative framework, which will only patch 343 the kernel if an affected CPU is detected. 344 345 If unsure, say Y. 346 347config ARM64_ERRATUM_824069 348 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 349 default y 350 select ARM64_WORKAROUND_CLEAN_CACHE 351 help 352 This option adds an alternative code sequence to work around ARM 353 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 354 to a coherent interconnect. 355 356 If a Cortex-A53 processor is executing a store or prefetch for 357 write instruction at the same time as a processor in another 358 cluster is executing a cache maintenance operation to the same 359 address, then this erratum might cause a clean cache line to be 360 incorrectly marked as dirty. 361 362 The workaround promotes data cache clean instructions to 363 data cache clean-and-invalidate. 364 Please note that this option does not necessarily enable the 365 workaround, as it depends on the alternative framework, which will 366 only patch the kernel if an affected CPU is detected. 367 368 If unsure, say Y. 369 370config ARM64_ERRATUM_819472 371 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 372 default y 373 select ARM64_WORKAROUND_CLEAN_CACHE 374 help 375 This option adds an alternative code sequence to work around ARM 376 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 377 present when it is connected to a coherent interconnect. 378 379 If the processor is executing a load and store exclusive sequence at 380 the same time as a processor in another cluster is executing a cache 381 maintenance operation to the same address, then this erratum might 382 cause data corruption. 383 384 The workaround promotes data cache clean instructions to 385 data cache clean-and-invalidate. 386 Please note that this does not necessarily enable the workaround, 387 as it depends on the alternative framework, which will only patch 388 the kernel if an affected CPU is detected. 389 390 If unsure, say Y. 391 392config ARM64_ERRATUM_832075 393 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 394 default y 395 help 396 This option adds an alternative code sequence to work around ARM 397 erratum 832075 on Cortex-A57 parts up to r1p2. 398 399 Affected Cortex-A57 parts might deadlock when exclusive load/store 400 instructions to Write-Back memory are mixed with Device loads. 401 402 The workaround is to promote device loads to use Load-Acquire 403 semantics. 404 Please note that this does not necessarily enable the workaround, 405 as it depends on the alternative framework, which will only patch 406 the kernel if an affected CPU is detected. 407 408 If unsure, say Y. 409 410config ARM64_ERRATUM_834220 411 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 412 depends on KVM 413 default y 414 help 415 This option adds an alternative code sequence to work around ARM 416 erratum 834220 on Cortex-A57 parts up to r1p2. 417 418 Affected Cortex-A57 parts might report a Stage 2 translation 419 fault as the result of a Stage 1 fault for load crossing a 420 page boundary when there is a permission or device memory 421 alignment fault at Stage 1 and a translation fault at Stage 2. 422 423 The workaround is to verify that the Stage 1 translation 424 doesn't generate a fault before handling the Stage 2 fault. 425 Please note that this does not necessarily enable the workaround, 426 as it depends on the alternative framework, which will only patch 427 the kernel if an affected CPU is detected. 428 429 If unsure, say Y. 430 431config ARM64_ERRATUM_845719 432 bool "Cortex-A53: 845719: a load might read incorrect data" 433 depends on COMPAT 434 default y 435 help 436 This option adds an alternative code sequence to work around ARM 437 erratum 845719 on Cortex-A53 parts up to r0p4. 438 439 When running a compat (AArch32) userspace on an affected Cortex-A53 440 part, a load at EL0 from a virtual address that matches the bottom 32 441 bits of the virtual address used by a recent load at (AArch64) EL1 442 might return incorrect data. 443 444 The workaround is to write the contextidr_el1 register on exception 445 return to a 32-bit task. 446 Please note that this does not necessarily enable the workaround, 447 as it depends on the alternative framework, which will only patch 448 the kernel if an affected CPU is detected. 449 450 If unsure, say Y. 451 452config ARM64_ERRATUM_843419 453 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 454 default y 455 select ARM64_MODULE_PLTS if MODULES 456 help 457 This option links the kernel with '--fix-cortex-a53-843419' and 458 enables PLT support to replace certain ADRP instructions, which can 459 cause subsequent memory accesses to use an incorrect address on 460 Cortex-A53 parts up to r0p4. 461 462 If unsure, say Y. 463 464config ARM64_ERRATUM_1024718 465 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 466 default y 467 help 468 This option adds work around for Arm Cortex-A55 Erratum 1024718. 469 470 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 471 update of the hardware dirty bit when the DBM/AP bits are updated 472 without a break-before-make. The work around is to disable the usage 473 of hardware DBM locally on the affected cores. CPUs not affected by 474 erratum will continue to use the feature. 475 476 If unsure, say Y. 477 478config ARM64_ERRATUM_1188873 479 bool "Cortex-A76: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 480 default y 481 select ARM_ARCH_TIMER_OOL_WORKAROUND 482 help 483 This option adds work arounds for ARM Cortex-A76 erratum 1188873 484 485 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could cause 486 register corruption when accessing the timer registers from 487 AArch32 userspace. 488 489 If unsure, say Y. 490 491config ARM64_ERRATUM_1165522 492 bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 493 default y 494 help 495 This option adds work arounds for ARM Cortex-A76 erratum 1165522 496 497 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 498 corrupted TLBs by speculating an AT instruction during a guest 499 context switch. 500 501 If unsure, say Y. 502 503config ARM64_ERRATUM_1286807 504 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 505 default y 506 select ARM64_WORKAROUND_REPEAT_TLBI 507 help 508 This option adds workaround for ARM Cortex-A76 erratum 1286807 509 510 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 511 address for a cacheable mapping of a location is being 512 accessed by a core while another core is remapping the virtual 513 address to a new physical page using the recommended 514 break-before-make sequence, then under very rare circumstances 515 TLBI+DSB completes before a read using the translation being 516 invalidated has been observed by other observers. The 517 workaround repeats the TLBI+DSB operation. 518 519 If unsure, say Y. 520 521config CAVIUM_ERRATUM_22375 522 bool "Cavium erratum 22375, 24313" 523 default y 524 help 525 Enable workaround for erratum 22375, 24313. 526 527 This implements two gicv3-its errata workarounds for ThunderX. Both 528 with small impact affecting only ITS table allocation. 529 530 erratum 22375: only alloc 8MB table size 531 erratum 24313: ignore memory access type 532 533 The fixes are in ITS initialization and basically ignore memory access 534 type and table size provided by the TYPER and BASER registers. 535 536 If unsure, say Y. 537 538config CAVIUM_ERRATUM_23144 539 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 540 depends on NUMA 541 default y 542 help 543 ITS SYNC command hang for cross node io and collections/cpu mapping. 544 545 If unsure, say Y. 546 547config CAVIUM_ERRATUM_23154 548 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 549 default y 550 help 551 The gicv3 of ThunderX requires a modified version for 552 reading the IAR status to ensure data synchronization 553 (access to icc_iar1_el1 is not sync'ed before and after). 554 555 If unsure, say Y. 556 557config CAVIUM_ERRATUM_27456 558 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 559 default y 560 help 561 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 562 instructions may cause the icache to become corrupted if it 563 contains data for a non-current ASID. The fix is to 564 invalidate the icache when changing the mm context. 565 566 If unsure, say Y. 567 568config CAVIUM_ERRATUM_30115 569 bool "Cavium erratum 30115: Guest may disable interrupts in host" 570 default y 571 help 572 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 573 1.2, and T83 Pass 1.0, KVM guest execution may disable 574 interrupts in host. Trapping both GICv3 group-0 and group-1 575 accesses sidesteps the issue. 576 577 If unsure, say Y. 578 579config QCOM_FALKOR_ERRATUM_1003 580 bool "Falkor E1003: Incorrect translation due to ASID change" 581 default y 582 help 583 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 584 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 585 in TTBR1_EL1, this situation only occurs in the entry trampoline and 586 then only for entries in the walk cache, since the leaf translation 587 is unchanged. Work around the erratum by invalidating the walk cache 588 entries for the trampoline before entering the kernel proper. 589 590config ARM64_WORKAROUND_REPEAT_TLBI 591 bool 592 help 593 Enable the repeat TLBI workaround for Falkor erratum 1009 and 594 Cortex-A76 erratum 1286807. 595 596config QCOM_FALKOR_ERRATUM_1009 597 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 598 default y 599 select ARM64_WORKAROUND_REPEAT_TLBI 600 help 601 On Falkor v1, the CPU may prematurely complete a DSB following a 602 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 603 one more time to fix the issue. 604 605 If unsure, say Y. 606 607config QCOM_QDF2400_ERRATUM_0065 608 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 609 default y 610 help 611 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 612 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 613 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 614 615 If unsure, say Y. 616 617config SOCIONEXT_SYNQUACER_PREITS 618 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 619 default y 620 help 621 Socionext Synquacer SoCs implement a separate h/w block to generate 622 MSI doorbell writes with non-zero values for the device ID. 623 624 If unsure, say Y. 625 626config HISILICON_ERRATUM_161600802 627 bool "Hip07 161600802: Erroneous redistributor VLPI base" 628 default y 629 help 630 The HiSilicon Hip07 SoC usees the wrong redistributor base 631 when issued ITS commands such as VMOVP and VMAPP, and requires 632 a 128kB offset to be applied to the target address in this commands. 633 634 If unsure, say Y. 635 636config QCOM_FALKOR_ERRATUM_E1041 637 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 638 default y 639 help 640 Falkor CPU may speculatively fetch instructions from an improper 641 memory location when MMU translation is changed from SCTLR_ELn[M]=1 642 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 643 644 If unsure, say Y. 645 646config FUJITSU_ERRATUM_010001 647 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 648 default y 649 help 650 This option adds workaround for Fujitsu-A64FX erratum E#010001. 651 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 652 accesses may cause undefined fault (Data abort, DFSC=0b111111). 653 This fault occurs under a specific hardware condition when a 654 load/store instruction performs an address translation using: 655 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 656 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 657 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 658 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 659 660 The workaround is to ensure these bits are clear in TCR_ELx. 661 The workaround only affect the Fujitsu-A64FX. 662 663 If unsure, say Y. 664 665endmenu 666 667 668choice 669 prompt "Page size" 670 default ARM64_4K_PAGES 671 help 672 Page size (translation granule) configuration. 673 674config ARM64_4K_PAGES 675 bool "4KB" 676 help 677 This feature enables 4KB pages support. 678 679config ARM64_16K_PAGES 680 bool "16KB" 681 help 682 The system will use 16KB pages support. AArch32 emulation 683 requires applications compiled with 16K (or a multiple of 16K) 684 aligned segments. 685 686config ARM64_64K_PAGES 687 bool "64KB" 688 help 689 This feature enables 64KB pages support (4KB by default) 690 allowing only two levels of page tables and faster TLB 691 look-up. AArch32 emulation requires applications compiled 692 with 64K aligned segments. 693 694endchoice 695 696choice 697 prompt "Virtual address space size" 698 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 699 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 700 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 701 help 702 Allows choosing one of multiple possible virtual address 703 space sizes. The level of translation table is determined by 704 a combination of page size and virtual address space size. 705 706config ARM64_VA_BITS_36 707 bool "36-bit" if EXPERT 708 depends on ARM64_16K_PAGES 709 710config ARM64_VA_BITS_39 711 bool "39-bit" 712 depends on ARM64_4K_PAGES 713 714config ARM64_VA_BITS_42 715 bool "42-bit" 716 depends on ARM64_64K_PAGES 717 718config ARM64_VA_BITS_47 719 bool "47-bit" 720 depends on ARM64_16K_PAGES 721 722config ARM64_VA_BITS_48 723 bool "48-bit" 724 725config ARM64_USER_VA_BITS_52 726 bool "52-bit (user)" 727 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 728 help 729 Enable 52-bit virtual addressing for userspace when explicitly 730 requested via a hint to mmap(). The kernel will continue to 731 use 48-bit virtual addresses for its own mappings. 732 733 NOTE: Enabling 52-bit virtual addressing in conjunction with 734 ARMv8.3 Pointer Authentication will result in the PAC being 735 reduced from 7 bits to 3 bits, which may have a significant 736 impact on its susceptibility to brute-force attacks. 737 738 If unsure, select 48-bit virtual addressing instead. 739 740endchoice 741 742config ARM64_FORCE_52BIT 743 bool "Force 52-bit virtual addresses for userspace" 744 depends on ARM64_USER_VA_BITS_52 && EXPERT 745 help 746 For systems with 52-bit userspace VAs enabled, the kernel will attempt 747 to maintain compatibility with older software by providing 48-bit VAs 748 unless a hint is supplied to mmap. 749 750 This configuration option disables the 48-bit compatibility logic, and 751 forces all userspace addresses to be 52-bit on HW that supports it. One 752 should only enable this configuration option for stress testing userspace 753 memory management code. If unsure say N here. 754 755config ARM64_VA_BITS 756 int 757 default 36 if ARM64_VA_BITS_36 758 default 39 if ARM64_VA_BITS_39 759 default 42 if ARM64_VA_BITS_42 760 default 47 if ARM64_VA_BITS_47 761 default 48 if ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52 762 763choice 764 prompt "Physical address space size" 765 default ARM64_PA_BITS_48 766 help 767 Choose the maximum physical address range that the kernel will 768 support. 769 770config ARM64_PA_BITS_48 771 bool "48-bit" 772 773config ARM64_PA_BITS_52 774 bool "52-bit (ARMv8.2)" 775 depends on ARM64_64K_PAGES 776 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 777 help 778 Enable support for a 52-bit physical address space, introduced as 779 part of the ARMv8.2-LPA extension. 780 781 With this enabled, the kernel will also continue to work on CPUs that 782 do not support ARMv8.2-LPA, but with some added memory overhead (and 783 minor performance overhead). 784 785endchoice 786 787config ARM64_PA_BITS 788 int 789 default 48 if ARM64_PA_BITS_48 790 default 52 if ARM64_PA_BITS_52 791 792config CPU_BIG_ENDIAN 793 bool "Build big-endian kernel" 794 help 795 Say Y if you plan on running a kernel in big-endian mode. 796 797config SCHED_MC 798 bool "Multi-core scheduler support" 799 help 800 Multi-core scheduler support improves the CPU scheduler's decision 801 making when dealing with multi-core CPU chips at a cost of slightly 802 increased overhead in some places. If unsure say N here. 803 804config SCHED_SMT 805 bool "SMT scheduler support" 806 help 807 Improves the CPU scheduler's decision making when dealing with 808 MultiThreading at a cost of slightly increased overhead in some 809 places. If unsure say N here. 810 811config NR_CPUS 812 int "Maximum number of CPUs (2-4096)" 813 range 2 4096 814 default "256" 815 816config HOTPLUG_CPU 817 bool "Support for hot-pluggable CPUs" 818 select GENERIC_IRQ_MIGRATION 819 help 820 Say Y here to experiment with turning CPUs off and on. CPUs 821 can be controlled through /sys/devices/system/cpu. 822 823# Common NUMA Features 824config NUMA 825 bool "Numa Memory Allocation and Scheduler Support" 826 select ACPI_NUMA if ACPI 827 select OF_NUMA 828 help 829 Enable NUMA (Non Uniform Memory Access) support. 830 831 The kernel will try to allocate memory used by a CPU on the 832 local memory of the CPU and add some more 833 NUMA awareness to the kernel. 834 835config NODES_SHIFT 836 int "Maximum NUMA Nodes (as a power of 2)" 837 range 1 10 838 default "2" 839 depends on NEED_MULTIPLE_NODES 840 help 841 Specify the maximum number of NUMA Nodes available on the target 842 system. Increases memory reserved to accommodate various tables. 843 844config USE_PERCPU_NUMA_NODE_ID 845 def_bool y 846 depends on NUMA 847 848config HAVE_SETUP_PER_CPU_AREA 849 def_bool y 850 depends on NUMA 851 852config NEED_PER_CPU_EMBED_FIRST_CHUNK 853 def_bool y 854 depends on NUMA 855 856config HOLES_IN_ZONE 857 def_bool y 858 859source "kernel/Kconfig.hz" 860 861config ARCH_SUPPORTS_DEBUG_PAGEALLOC 862 def_bool y 863 864config ARCH_SPARSEMEM_ENABLE 865 def_bool y 866 select SPARSEMEM_VMEMMAP_ENABLE 867 868config ARCH_SPARSEMEM_DEFAULT 869 def_bool ARCH_SPARSEMEM_ENABLE 870 871config ARCH_SELECT_MEMORY_MODEL 872 def_bool ARCH_SPARSEMEM_ENABLE 873 874config ARCH_FLATMEM_ENABLE 875 def_bool !NUMA 876 877config HAVE_ARCH_PFN_VALID 878 def_bool y 879 880config HW_PERF_EVENTS 881 def_bool y 882 depends on ARM_PMU 883 884config SYS_SUPPORTS_HUGETLBFS 885 def_bool y 886 887config ARCH_WANT_HUGE_PMD_SHARE 888 def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 889 890config ARCH_HAS_CACHE_LINE_SIZE 891 def_bool y 892 893config SECCOMP 894 bool "Enable seccomp to safely compute untrusted bytecode" 895 ---help--- 896 This kernel feature is useful for number crunching applications 897 that may need to compute untrusted bytecode during their 898 execution. By using pipes or other transports made available to 899 the process as file descriptors supporting the read/write 900 syscalls, it's possible to isolate those applications in 901 their own address space using seccomp. Once seccomp is 902 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 903 and the task is only allowed to execute a few safe syscalls 904 defined by each seccomp mode. 905 906config PARAVIRT 907 bool "Enable paravirtualization code" 908 help 909 This changes the kernel so it can modify itself when it is run 910 under a hypervisor, potentially improving performance significantly 911 over full virtualization. 912 913config PARAVIRT_TIME_ACCOUNTING 914 bool "Paravirtual steal time accounting" 915 select PARAVIRT 916 default n 917 help 918 Select this option to enable fine granularity task steal time 919 accounting. Time spent executing other tasks in parallel with 920 the current vCPU is discounted from the vCPU power. To account for 921 that, there can be a small performance impact. 922 923 If in doubt, say N here. 924 925config KEXEC 926 depends on PM_SLEEP_SMP 927 select KEXEC_CORE 928 bool "kexec system call" 929 ---help--- 930 kexec is a system call that implements the ability to shutdown your 931 current kernel, and to start another kernel. It is like a reboot 932 but it is independent of the system firmware. And like a reboot 933 you can start any kernel with it, not just Linux. 934 935config KEXEC_FILE 936 bool "kexec file based system call" 937 select KEXEC_CORE 938 help 939 This is new version of kexec system call. This system call is 940 file based and takes file descriptors as system call argument 941 for kernel and initramfs as opposed to list of segments as 942 accepted by previous system call. 943 944config KEXEC_VERIFY_SIG 945 bool "Verify kernel signature during kexec_file_load() syscall" 946 depends on KEXEC_FILE 947 help 948 Select this option to verify a signature with loaded kernel 949 image. If configured, any attempt of loading a image without 950 valid signature will fail. 951 952 In addition to that option, you need to enable signature 953 verification for the corresponding kernel image type being 954 loaded in order for this to work. 955 956config KEXEC_IMAGE_VERIFY_SIG 957 bool "Enable Image signature verification support" 958 default y 959 depends on KEXEC_VERIFY_SIG 960 depends on EFI && SIGNED_PE_FILE_VERIFICATION 961 help 962 Enable Image signature verification support. 963 964comment "Support for PE file signature verification disabled" 965 depends on KEXEC_VERIFY_SIG 966 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 967 968config CRASH_DUMP 969 bool "Build kdump crash kernel" 970 help 971 Generate crash dump after being started by kexec. This should 972 be normally only set in special crash dump kernels which are 973 loaded in the main kernel with kexec-tools into a specially 974 reserved region and then later executed after a crash by 975 kdump/kexec. 976 977 For more details see Documentation/kdump/kdump.txt 978 979config XEN_DOM0 980 def_bool y 981 depends on XEN 982 983config XEN 984 bool "Xen guest support on ARM64" 985 depends on ARM64 && OF 986 select SWIOTLB_XEN 987 select PARAVIRT 988 help 989 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 990 991config FORCE_MAX_ZONEORDER 992 int 993 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 994 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 995 default "11" 996 help 997 The kernel memory allocator divides physically contiguous memory 998 blocks into "zones", where each zone is a power of two number of 999 pages. This option selects the largest power of two that the kernel 1000 keeps in the memory allocator. If you need to allocate very large 1001 blocks of physically contiguous memory, then you may need to 1002 increase this value. 1003 1004 This config option is actually maximum order plus one. For example, 1005 a value of 11 means that the largest free memory block is 2^10 pages. 1006 1007 We make sure that we can allocate upto a HugePage size for each configuration. 1008 Hence we have : 1009 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1010 1011 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1012 4M allocations matching the default size used by generic code. 1013 1014config UNMAP_KERNEL_AT_EL0 1015 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1016 default y 1017 help 1018 Speculation attacks against some high-performance processors can 1019 be used to bypass MMU permission checks and leak kernel data to 1020 userspace. This can be defended against by unmapping the kernel 1021 when running in userspace, mapping it back in on exception entry 1022 via a trampoline page in the vector table. 1023 1024 If unsure, say Y. 1025 1026config HARDEN_BRANCH_PREDICTOR 1027 bool "Harden the branch predictor against aliasing attacks" if EXPERT 1028 default y 1029 help 1030 Speculation attacks against some high-performance processors rely on 1031 being able to manipulate the branch predictor for a victim context by 1032 executing aliasing branches in the attacker context. Such attacks 1033 can be partially mitigated against by clearing internal branch 1034 predictor state and limiting the prediction logic in some situations. 1035 1036 This config option will take CPU-specific actions to harden the 1037 branch predictor against aliasing attacks and may rely on specific 1038 instruction sequences or control bits being set by the system 1039 firmware. 1040 1041 If unsure, say Y. 1042 1043config HARDEN_EL2_VECTORS 1044 bool "Harden EL2 vector mapping against system register leak" if EXPERT 1045 default y 1046 help 1047 Speculation attacks against some high-performance processors can 1048 be used to leak privileged information such as the vector base 1049 register, resulting in a potential defeat of the EL2 layout 1050 randomization. 1051 1052 This config option will map the vectors to a fixed location, 1053 independent of the EL2 code mapping, so that revealing VBAR_EL2 1054 to an attacker does not give away any extra information. This 1055 only gets enabled on affected CPUs. 1056 1057 If unsure, say Y. 1058 1059config ARM64_SSBD 1060 bool "Speculative Store Bypass Disable" if EXPERT 1061 default y 1062 help 1063 This enables mitigation of the bypassing of previous stores 1064 by speculative loads. 1065 1066 If unsure, say Y. 1067 1068config RODATA_FULL_DEFAULT_ENABLED 1069 bool "Apply r/o permissions of VM areas also to their linear aliases" 1070 default y 1071 help 1072 Apply read-only attributes of VM areas to the linear alias of 1073 the backing pages as well. This prevents code or read-only data 1074 from being modified (inadvertently or intentionally) via another 1075 mapping of the same memory page. This additional enhancement can 1076 be turned off at runtime by passing rodata=[off|on] (and turned on 1077 with rodata=full if this option is set to 'n') 1078 1079 This requires the linear region to be mapped down to pages, 1080 which may adversely affect performance in some cases. 1081 1082menuconfig ARMV8_DEPRECATED 1083 bool "Emulate deprecated/obsolete ARMv8 instructions" 1084 depends on COMPAT 1085 depends on SYSCTL 1086 help 1087 Legacy software support may require certain instructions 1088 that have been deprecated or obsoleted in the architecture. 1089 1090 Enable this config to enable selective emulation of these 1091 features. 1092 1093 If unsure, say Y 1094 1095if ARMV8_DEPRECATED 1096 1097config SWP_EMULATION 1098 bool "Emulate SWP/SWPB instructions" 1099 help 1100 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1101 they are always undefined. Say Y here to enable software 1102 emulation of these instructions for userspace using LDXR/STXR. 1103 1104 In some older versions of glibc [<=2.8] SWP is used during futex 1105 trylock() operations with the assumption that the code will not 1106 be preempted. This invalid assumption may be more likely to fail 1107 with SWP emulation enabled, leading to deadlock of the user 1108 application. 1109 1110 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1111 on an external transaction monitoring block called a global 1112 monitor to maintain update atomicity. If your system does not 1113 implement a global monitor, this option can cause programs that 1114 perform SWP operations to uncached memory to deadlock. 1115 1116 If unsure, say Y 1117 1118config CP15_BARRIER_EMULATION 1119 bool "Emulate CP15 Barrier instructions" 1120 help 1121 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1122 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1123 strongly recommended to use the ISB, DSB, and DMB 1124 instructions instead. 1125 1126 Say Y here to enable software emulation of these 1127 instructions for AArch32 userspace code. When this option is 1128 enabled, CP15 barrier usage is traced which can help 1129 identify software that needs updating. 1130 1131 If unsure, say Y 1132 1133config SETEND_EMULATION 1134 bool "Emulate SETEND instruction" 1135 help 1136 The SETEND instruction alters the data-endianness of the 1137 AArch32 EL0, and is deprecated in ARMv8. 1138 1139 Say Y here to enable software emulation of the instruction 1140 for AArch32 userspace code. 1141 1142 Note: All the cpus on the system must have mixed endian support at EL0 1143 for this feature to be enabled. If a new CPU - which doesn't support mixed 1144 endian - is hotplugged in after this feature has been enabled, there could 1145 be unexpected results in the applications. 1146 1147 If unsure, say Y 1148endif 1149 1150config ARM64_SW_TTBR0_PAN 1151 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1152 help 1153 Enabling this option prevents the kernel from accessing 1154 user-space memory directly by pointing TTBR0_EL1 to a reserved 1155 zeroed area and reserved ASID. The user access routines 1156 restore the valid TTBR0_EL1 temporarily. 1157 1158menu "ARMv8.1 architectural features" 1159 1160config ARM64_HW_AFDBM 1161 bool "Support for hardware updates of the Access and Dirty page flags" 1162 default y 1163 help 1164 The ARMv8.1 architecture extensions introduce support for 1165 hardware updates of the access and dirty information in page 1166 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1167 capable processors, accesses to pages with PTE_AF cleared will 1168 set this bit instead of raising an access flag fault. 1169 Similarly, writes to read-only pages with the DBM bit set will 1170 clear the read-only bit (AP[2]) instead of raising a 1171 permission fault. 1172 1173 Kernels built with this configuration option enabled continue 1174 to work on pre-ARMv8.1 hardware and the performance impact is 1175 minimal. If unsure, say Y. 1176 1177config ARM64_PAN 1178 bool "Enable support for Privileged Access Never (PAN)" 1179 default y 1180 help 1181 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1182 prevents the kernel or hypervisor from accessing user-space (EL0) 1183 memory directly. 1184 1185 Choosing this option will cause any unprotected (not using 1186 copy_to_user et al) memory access to fail with a permission fault. 1187 1188 The feature is detected at runtime, and will remain as a 'nop' 1189 instruction if the cpu does not implement the feature. 1190 1191config ARM64_LSE_ATOMICS 1192 bool "Atomic instructions" 1193 default y 1194 help 1195 As part of the Large System Extensions, ARMv8.1 introduces new 1196 atomic instructions that are designed specifically to scale in 1197 very large systems. 1198 1199 Say Y here to make use of these instructions for the in-kernel 1200 atomic routines. This incurs a small overhead on CPUs that do 1201 not support these instructions and requires the kernel to be 1202 built with binutils >= 2.25 in order for the new instructions 1203 to be used. 1204 1205config ARM64_VHE 1206 bool "Enable support for Virtualization Host Extensions (VHE)" 1207 default y 1208 help 1209 Virtualization Host Extensions (VHE) allow the kernel to run 1210 directly at EL2 (instead of EL1) on processors that support 1211 it. This leads to better performance for KVM, as they reduce 1212 the cost of the world switch. 1213 1214 Selecting this option allows the VHE feature to be detected 1215 at runtime, and does not affect processors that do not 1216 implement this feature. 1217 1218endmenu 1219 1220menu "ARMv8.2 architectural features" 1221 1222config ARM64_UAO 1223 bool "Enable support for User Access Override (UAO)" 1224 default y 1225 help 1226 User Access Override (UAO; part of the ARMv8.2 Extensions) 1227 causes the 'unprivileged' variant of the load/store instructions to 1228 be overridden to be privileged. 1229 1230 This option changes get_user() and friends to use the 'unprivileged' 1231 variant of the load/store instructions. This ensures that user-space 1232 really did have access to the supplied memory. When addr_limit is 1233 set to kernel memory the UAO bit will be set, allowing privileged 1234 access to kernel memory. 1235 1236 Choosing this option will cause copy_to_user() et al to use user-space 1237 memory permissions. 1238 1239 The feature is detected at runtime, the kernel will use the 1240 regular load/store instructions if the cpu does not implement the 1241 feature. 1242 1243config ARM64_PMEM 1244 bool "Enable support for persistent memory" 1245 select ARCH_HAS_PMEM_API 1246 select ARCH_HAS_UACCESS_FLUSHCACHE 1247 help 1248 Say Y to enable support for the persistent memory API based on the 1249 ARMv8.2 DCPoP feature. 1250 1251 The feature is detected at runtime, and the kernel will use DC CVAC 1252 operations if DC CVAP is not supported (following the behaviour of 1253 DC CVAP itself if the system does not define a point of persistence). 1254 1255config ARM64_RAS_EXTN 1256 bool "Enable support for RAS CPU Extensions" 1257 default y 1258 help 1259 CPUs that support the Reliability, Availability and Serviceability 1260 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1261 errors, classify them and report them to software. 1262 1263 On CPUs with these extensions system software can use additional 1264 barriers to determine if faults are pending and read the 1265 classification from a new set of registers. 1266 1267 Selecting this feature will allow the kernel to use these barriers 1268 and access the new registers if the system supports the extension. 1269 Platform RAS features may additionally depend on firmware support. 1270 1271config ARM64_CNP 1272 bool "Enable support for Common Not Private (CNP) translations" 1273 default y 1274 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1275 help 1276 Common Not Private (CNP) allows translation table entries to 1277 be shared between different PEs in the same inner shareable 1278 domain, so the hardware can use this fact to optimise the 1279 caching of such entries in the TLB. 1280 1281 Selecting this option allows the CNP feature to be detected 1282 at runtime, and does not affect PEs that do not implement 1283 this feature. 1284 1285endmenu 1286 1287menu "ARMv8.3 architectural features" 1288 1289config ARM64_PTR_AUTH 1290 bool "Enable support for pointer authentication" 1291 default y 1292 help 1293 Pointer authentication (part of the ARMv8.3 Extensions) provides 1294 instructions for signing and authenticating pointers against secret 1295 keys, which can be used to mitigate Return Oriented Programming (ROP) 1296 and other attacks. 1297 1298 This option enables these instructions at EL0 (i.e. for userspace). 1299 1300 Choosing this option will cause the kernel to initialise secret keys 1301 for each process at exec() time, with these keys being 1302 context-switched along with the process. 1303 1304 The feature is detected at runtime. If the feature is not present in 1305 hardware it will not be advertised to userspace nor will it be 1306 enabled. 1307 1308endmenu 1309 1310config ARM64_SVE 1311 bool "ARM Scalable Vector Extension support" 1312 default y 1313 depends on !KVM || ARM64_VHE 1314 help 1315 The Scalable Vector Extension (SVE) is an extension to the AArch64 1316 execution state which complements and extends the SIMD functionality 1317 of the base architecture to support much larger vectors and to enable 1318 additional vectorisation opportunities. 1319 1320 To enable use of this extension on CPUs that implement it, say Y. 1321 1322 Note that for architectural reasons, firmware _must_ implement SVE 1323 support when running on SVE capable hardware. The required support 1324 is present in: 1325 1326 * version 1.5 and later of the ARM Trusted Firmware 1327 * the AArch64 boot wrapper since commit 5e1261e08abf 1328 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1329 1330 For other firmware implementations, consult the firmware documentation 1331 or vendor. 1332 1333 If you need the kernel to boot on SVE-capable hardware with broken 1334 firmware, you may need to say N here until you get your firmware 1335 fixed. Otherwise, you may experience firmware panics or lockups when 1336 booting the kernel. If unsure and you are not observing these 1337 symptoms, you should assume that it is safe to say Y. 1338 1339 CPUs that support SVE are architecturally required to support the 1340 Virtualization Host Extensions (VHE), so the kernel makes no 1341 provision for supporting SVE alongside KVM without VHE enabled. 1342 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1343 KVM in the same kernel image. 1344 1345config ARM64_MODULE_PLTS 1346 bool 1347 select HAVE_MOD_ARCH_SPECIFIC 1348 1349config ARM64_PSEUDO_NMI 1350 bool "Support for NMI-like interrupts" 1351 select CONFIG_ARM_GIC_V3 1352 help 1353 Adds support for mimicking Non-Maskable Interrupts through the use of 1354 GIC interrupt priority. This support requires version 3 or later of 1355 Arm GIC. 1356 1357 This high priority configuration for interrupts needs to be 1358 explicitly enabled by setting the kernel parameter 1359 "irqchip.gicv3_pseudo_nmi" to 1. 1360 1361 If unsure, say N 1362 1363config RELOCATABLE 1364 bool 1365 help 1366 This builds the kernel as a Position Independent Executable (PIE), 1367 which retains all relocation metadata required to relocate the 1368 kernel binary at runtime to a different virtual address than the 1369 address it was linked at. 1370 Since AArch64 uses the RELA relocation format, this requires a 1371 relocation pass at runtime even if the kernel is loaded at the 1372 same address it was linked at. 1373 1374config RANDOMIZE_BASE 1375 bool "Randomize the address of the kernel image" 1376 select ARM64_MODULE_PLTS if MODULES 1377 select RELOCATABLE 1378 help 1379 Randomizes the virtual address at which the kernel image is 1380 loaded, as a security feature that deters exploit attempts 1381 relying on knowledge of the location of kernel internals. 1382 1383 It is the bootloader's job to provide entropy, by passing a 1384 random u64 value in /chosen/kaslr-seed at kernel entry. 1385 1386 When booting via the UEFI stub, it will invoke the firmware's 1387 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1388 to the kernel proper. In addition, it will randomise the physical 1389 location of the kernel Image as well. 1390 1391 If unsure, say N. 1392 1393config RANDOMIZE_MODULE_REGION_FULL 1394 bool "Randomize the module region over a 4 GB range" 1395 depends on RANDOMIZE_BASE 1396 default y 1397 help 1398 Randomizes the location of the module region inside a 4 GB window 1399 covering the core kernel. This way, it is less likely for modules 1400 to leak information about the location of core kernel data structures 1401 but it does imply that function calls between modules and the core 1402 kernel will need to be resolved via veneers in the module PLT. 1403 1404 When this option is not set, the module region will be randomized over 1405 a limited range that contains the [_stext, _etext] interval of the 1406 core kernel, so branch relocations are always in range. 1407 1408config CC_HAVE_STACKPROTECTOR_SYSREG 1409 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1410 1411config STACKPROTECTOR_PER_TASK 1412 def_bool y 1413 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1414 1415endmenu 1416 1417menu "Boot options" 1418 1419config ARM64_ACPI_PARKING_PROTOCOL 1420 bool "Enable support for the ARM64 ACPI parking protocol" 1421 depends on ACPI 1422 help 1423 Enable support for the ARM64 ACPI parking protocol. If disabled 1424 the kernel will not allow booting through the ARM64 ACPI parking 1425 protocol even if the corresponding data is present in the ACPI 1426 MADT table. 1427 1428config CMDLINE 1429 string "Default kernel command string" 1430 default "" 1431 help 1432 Provide a set of default command-line options at build time by 1433 entering them here. As a minimum, you should specify the the 1434 root device (e.g. root=/dev/nfs). 1435 1436config CMDLINE_FORCE 1437 bool "Always use the default kernel command string" 1438 help 1439 Always use the default kernel command string, even if the boot 1440 loader passes other arguments to the kernel. 1441 This is useful if you cannot or don't want to change the 1442 command-line options your boot loader passes to the kernel. 1443 1444config EFI_STUB 1445 bool 1446 1447config EFI 1448 bool "UEFI runtime support" 1449 depends on OF && !CPU_BIG_ENDIAN 1450 depends on KERNEL_MODE_NEON 1451 select ARCH_SUPPORTS_ACPI 1452 select LIBFDT 1453 select UCS2_STRING 1454 select EFI_PARAMS_FROM_FDT 1455 select EFI_RUNTIME_WRAPPERS 1456 select EFI_STUB 1457 select EFI_ARMSTUB 1458 default y 1459 help 1460 This option provides support for runtime services provided 1461 by UEFI firmware (such as non-volatile variables, realtime 1462 clock, and platform reset). A UEFI stub is also provided to 1463 allow the kernel to be booted as an EFI application. This 1464 is only useful on systems that have UEFI firmware. 1465 1466config DMI 1467 bool "Enable support for SMBIOS (DMI) tables" 1468 depends on EFI 1469 default y 1470 help 1471 This enables SMBIOS/DMI feature for systems. 1472 1473 This option is only useful on systems that have UEFI firmware. 1474 However, even with this option, the resultant kernel should 1475 continue to boot on existing non-UEFI platforms. 1476 1477endmenu 1478 1479config COMPAT 1480 bool "Kernel support for 32-bit EL0" 1481 depends on ARM64_4K_PAGES || EXPERT 1482 select COMPAT_BINFMT_ELF if BINFMT_ELF 1483 select HAVE_UID16 1484 select OLD_SIGSUSPEND3 1485 select COMPAT_OLD_SIGACTION 1486 help 1487 This option enables support for a 32-bit EL0 running under a 64-bit 1488 kernel at EL1. AArch32-specific components such as system calls, 1489 the user helper functions, VFP support and the ptrace interface are 1490 handled appropriately by the kernel. 1491 1492 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1493 that you will only be able to execute AArch32 binaries that were compiled 1494 with page size aligned segments. 1495 1496 If you want to execute 32-bit userspace applications, say Y. 1497 1498config SYSVIPC_COMPAT 1499 def_bool y 1500 depends on COMPAT && SYSVIPC 1501 1502config ARCH_ENABLE_HUGEPAGE_MIGRATION 1503 def_bool y 1504 depends on HUGETLB_PAGE && MIGRATION 1505 1506menu "Power management options" 1507 1508source "kernel/power/Kconfig" 1509 1510config ARCH_HIBERNATION_POSSIBLE 1511 def_bool y 1512 depends on CPU_PM 1513 1514config ARCH_HIBERNATION_HEADER 1515 def_bool y 1516 depends on HIBERNATION 1517 1518config ARCH_SUSPEND_POSSIBLE 1519 def_bool y 1520 1521endmenu 1522 1523menu "CPU Power Management" 1524 1525source "drivers/cpuidle/Kconfig" 1526 1527source "drivers/cpufreq/Kconfig" 1528 1529endmenu 1530 1531source "drivers/firmware/Kconfig" 1532 1533source "drivers/acpi/Kconfig" 1534 1535source "arch/arm64/kvm/Kconfig" 1536 1537if CRYPTO 1538source "arch/arm64/crypto/Kconfig" 1539endif 1540