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