1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_CCA_REQUIRED if ACPI 5 select ACPI_GENERIC_GSI if ACPI 6 select ACPI_GTDT if ACPI 7 select ACPI_IORT if ACPI 8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 9 select ACPI_MCFG if (ACPI && PCI) 10 select ACPI_SPCR_TABLE if ACPI 11 select ACPI_PPTT if ACPI 12 select ARCH_CLOCKSOURCE_DATA 13 select ARCH_HAS_DEBUG_VIRTUAL 14 select ARCH_HAS_DEVMEM_IS_ALLOWED 15 select ARCH_HAS_DMA_COHERENT_TO_PFN 16 select ARCH_HAS_DMA_MMAP_PGPROT 17 select ARCH_HAS_DMA_PREP_COHERENT 18 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 19 select ARCH_HAS_ELF_RANDOMIZE 20 select ARCH_HAS_FAST_MULTIPLIER 21 select ARCH_HAS_FORTIFY_SOURCE 22 select ARCH_HAS_GCOV_PROFILE_ALL 23 select ARCH_HAS_GIGANTIC_PAGE 24 select ARCH_HAS_KCOV 25 select ARCH_HAS_KEEPINITRD 26 select ARCH_HAS_MEMBARRIER_SYNC_CORE 27 select ARCH_HAS_PTE_SPECIAL 28 select ARCH_HAS_SETUP_DMA_OPS 29 select ARCH_HAS_SET_MEMORY 30 select ARCH_HAS_STRICT_KERNEL_RWX 31 select ARCH_HAS_STRICT_MODULE_RWX 32 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 33 select ARCH_HAS_SYNC_DMA_FOR_CPU 34 select ARCH_HAS_SYSCALL_WRAPPER 35 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 36 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 37 select ARCH_HAVE_NMI_SAFE_CMPXCHG 38 select ARCH_INLINE_READ_LOCK if !PREEMPT 39 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT 40 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT 41 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT 42 select ARCH_INLINE_READ_UNLOCK if !PREEMPT 43 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT 44 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT 45 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT 46 select ARCH_INLINE_WRITE_LOCK if !PREEMPT 47 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT 48 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT 49 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT 50 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT 51 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT 52 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT 53 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT 54 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT 55 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT 56 select ARCH_INLINE_SPIN_LOCK if !PREEMPT 57 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT 58 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT 59 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT 60 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT 61 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT 62 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT 63 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT 64 select ARCH_KEEP_MEMBLOCK 65 select ARCH_USE_CMPXCHG_LOCKREF 66 select ARCH_USE_QUEUED_RWLOCKS 67 select ARCH_USE_QUEUED_SPINLOCKS 68 select ARCH_SUPPORTS_MEMORY_FAILURE 69 select ARCH_SUPPORTS_ATOMIC_RMW 70 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG 71 select ARCH_SUPPORTS_NUMA_BALANCING 72 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 73 select ARCH_WANT_FRAME_POINTERS 74 select ARCH_HAS_UBSAN_SANITIZE_ALL 75 select ARM_AMBA 76 select ARM_ARCH_TIMER 77 select ARM_GIC 78 select AUDIT_ARCH_COMPAT_GENERIC 79 select ARM_GIC_V2M if PCI 80 select ARM_GIC_V3 81 select ARM_GIC_V3_ITS if PCI 82 select ARM_PSCI_FW 83 select BUILDTIME_EXTABLE_SORT 84 select CLONE_BACKWARDS 85 select COMMON_CLK 86 select CPU_PM if (SUSPEND || CPU_IDLE) 87 select CRC32 88 select DCACHE_WORD_ACCESS 89 select DMA_DIRECT_REMAP 90 select EDAC_SUPPORT 91 select FRAME_POINTER 92 select GENERIC_ALLOCATOR 93 select GENERIC_ARCH_TOPOLOGY 94 select GENERIC_CLOCKEVENTS 95 select GENERIC_CLOCKEVENTS_BROADCAST 96 select GENERIC_CPU_AUTOPROBE 97 select GENERIC_CPU_VULNERABILITIES 98 select GENERIC_EARLY_IOREMAP 99 select GENERIC_IDLE_POLL_SETUP 100 select GENERIC_IRQ_MULTI_HANDLER 101 select GENERIC_IRQ_PROBE 102 select GENERIC_IRQ_SHOW 103 select GENERIC_IRQ_SHOW_LEVEL 104 select GENERIC_PCI_IOMAP 105 select GENERIC_SCHED_CLOCK 106 select GENERIC_SMP_IDLE_THREAD 107 select GENERIC_STRNCPY_FROM_USER 108 select GENERIC_STRNLEN_USER 109 select GENERIC_TIME_VSYSCALL 110 select HANDLE_DOMAIN_IRQ 111 select HARDIRQS_SW_RESEND 112 select HAVE_PCI 113 select HAVE_ACPI_APEI if (ACPI && EFI) 114 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 115 select HAVE_ARCH_AUDITSYSCALL 116 select HAVE_ARCH_BITREVERSE 117 select HAVE_ARCH_HUGE_VMAP 118 select HAVE_ARCH_JUMP_LABEL 119 select HAVE_ARCH_JUMP_LABEL_RELATIVE 120 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 121 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 122 select HAVE_ARCH_KGDB 123 select HAVE_ARCH_MMAP_RND_BITS 124 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 125 select HAVE_ARCH_PREL32_RELOCATIONS 126 select HAVE_ARCH_SECCOMP_FILTER 127 select HAVE_ARCH_STACKLEAK 128 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 129 select HAVE_ARCH_TRACEHOOK 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 131 select HAVE_ARCH_VMAP_STACK 132 select HAVE_ARM_SMCCC 133 select HAVE_EBPF_JIT 134 select HAVE_C_RECORDMCOUNT 135 select HAVE_CMPXCHG_DOUBLE 136 select HAVE_CMPXCHG_LOCAL 137 select HAVE_CONTEXT_TRACKING 138 select HAVE_DEBUG_BUGVERBOSE 139 select HAVE_DEBUG_KMEMLEAK 140 select HAVE_DMA_CONTIGUOUS 141 select HAVE_DYNAMIC_FTRACE 142 select HAVE_EFFICIENT_UNALIGNED_ACCESS 143 select HAVE_FTRACE_MCOUNT_RECORD 144 select HAVE_FUNCTION_TRACER 145 select HAVE_FUNCTION_GRAPH_TRACER 146 select HAVE_GCC_PLUGINS 147 select HAVE_HW_BREAKPOINT if PERF_EVENTS 148 select HAVE_IRQ_TIME_ACCOUNTING 149 select HAVE_MEMBLOCK_NODE_MAP if NUMA 150 select HAVE_NMI 151 select HAVE_PATA_PLATFORM 152 select HAVE_PERF_EVENTS 153 select HAVE_PERF_REGS 154 select HAVE_PERF_USER_STACK_DUMP 155 select HAVE_REGS_AND_STACK_ACCESS_API 156 select HAVE_FUNCTION_ARG_ACCESS_API 157 select HAVE_RCU_TABLE_FREE 158 select HAVE_RSEQ 159 select HAVE_STACKPROTECTOR 160 select HAVE_SYSCALL_TRACEPOINTS 161 select HAVE_KPROBES 162 select HAVE_KRETPROBES 163 select IOMMU_DMA if IOMMU_SUPPORT 164 select IRQ_DOMAIN 165 select IRQ_FORCED_THREADING 166 select MODULES_USE_ELF_RELA 167 select NEED_DMA_MAP_STATE 168 select NEED_SG_DMA_LENGTH 169 select OF 170 select OF_EARLY_FLATTREE 171 select PCI_DOMAINS_GENERIC if PCI 172 select PCI_ECAM if (ACPI && PCI) 173 select PCI_SYSCALL if PCI 174 select POWER_RESET 175 select POWER_SUPPLY 176 select REFCOUNT_FULL 177 select SPARSE_IRQ 178 select SWIOTLB 179 select SYSCTL_EXCEPTION_TRACE 180 select THREAD_INFO_IN_TASK 181 help 182 ARM 64-bit (AArch64) Linux support. 183 184config 64BIT 185 def_bool y 186 187config MMU 188 def_bool y 189 190config ARM64_PAGE_SHIFT 191 int 192 default 16 if ARM64_64K_PAGES 193 default 14 if ARM64_16K_PAGES 194 default 12 195 196config ARM64_CONT_SHIFT 197 int 198 default 5 if ARM64_64K_PAGES 199 default 7 if ARM64_16K_PAGES 200 default 4 201 202config ARCH_MMAP_RND_BITS_MIN 203 default 14 if ARM64_64K_PAGES 204 default 16 if ARM64_16K_PAGES 205 default 18 206 207# max bits determined by the following formula: 208# VA_BITS - PAGE_SHIFT - 3 209config ARCH_MMAP_RND_BITS_MAX 210 default 19 if ARM64_VA_BITS=36 211 default 24 if ARM64_VA_BITS=39 212 default 27 if ARM64_VA_BITS=42 213 default 30 if ARM64_VA_BITS=47 214 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 215 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 216 default 33 if ARM64_VA_BITS=48 217 default 14 if ARM64_64K_PAGES 218 default 16 if ARM64_16K_PAGES 219 default 18 220 221config ARCH_MMAP_RND_COMPAT_BITS_MIN 222 default 7 if ARM64_64K_PAGES 223 default 9 if ARM64_16K_PAGES 224 default 11 225 226config ARCH_MMAP_RND_COMPAT_BITS_MAX 227 default 16 228 229config NO_IOPORT_MAP 230 def_bool y if !PCI 231 232config STACKTRACE_SUPPORT 233 def_bool y 234 235config ILLEGAL_POINTER_VALUE 236 hex 237 default 0xdead000000000000 238 239config LOCKDEP_SUPPORT 240 def_bool y 241 242config TRACE_IRQFLAGS_SUPPORT 243 def_bool y 244 245config GENERIC_BUG 246 def_bool y 247 depends on BUG 248 249config GENERIC_BUG_RELATIVE_POINTERS 250 def_bool y 251 depends on GENERIC_BUG 252 253config GENERIC_HWEIGHT 254 def_bool y 255 256config GENERIC_CSUM 257 def_bool y 258 259config GENERIC_CALIBRATE_DELAY 260 def_bool y 261 262config ZONE_DMA32 263 def_bool y 264 265config HAVE_GENERIC_GUP 266 def_bool y 267 268config ARCH_ENABLE_MEMORY_HOTPLUG 269 def_bool y 270 271config SMP 272 def_bool y 273 274config KERNEL_MODE_NEON 275 def_bool y 276 277config FIX_EARLYCON_MEM 278 def_bool y 279 280config PGTABLE_LEVELS 281 int 282 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 283 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 284 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_USER_VA_BITS_52) 285 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 286 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 287 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 288 289config ARCH_SUPPORTS_UPROBES 290 def_bool y 291 292config ARCH_PROC_KCORE_TEXT 293 def_bool y 294 295source "arch/arm64/Kconfig.platforms" 296 297menu "Kernel Features" 298 299menu "ARM errata workarounds via the alternatives framework" 300 301config ARM64_WORKAROUND_CLEAN_CACHE 302 bool 303 304config ARM64_ERRATUM_826319 305 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 306 default y 307 select ARM64_WORKAROUND_CLEAN_CACHE 308 help 309 This option adds an alternative code sequence to work around ARM 310 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 311 AXI master interface and an L2 cache. 312 313 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 314 and is unable to accept a certain write via this interface, it will 315 not progress on read data presented on the read data channel and the 316 system can deadlock. 317 318 The workaround promotes data cache clean instructions to 319 data cache clean-and-invalidate. 320 Please note that this does not necessarily enable the workaround, 321 as it depends on the alternative framework, which will only patch 322 the kernel if an affected CPU is detected. 323 324 If unsure, say Y. 325 326config ARM64_ERRATUM_827319 327 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 328 default y 329 select ARM64_WORKAROUND_CLEAN_CACHE 330 help 331 This option adds an alternative code sequence to work around ARM 332 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 333 master interface and an L2 cache. 334 335 Under certain conditions this erratum can cause a clean line eviction 336 to occur at the same time as another transaction to the same address 337 on the AMBA 5 CHI interface, which can cause data corruption if the 338 interconnect reorders the two transactions. 339 340 The workaround promotes data cache clean instructions to 341 data cache clean-and-invalidate. 342 Please note that this does not necessarily enable the workaround, 343 as it depends on the alternative framework, which will only patch 344 the kernel if an affected CPU is detected. 345 346 If unsure, say Y. 347 348config ARM64_ERRATUM_824069 349 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 350 default y 351 select ARM64_WORKAROUND_CLEAN_CACHE 352 help 353 This option adds an alternative code sequence to work around ARM 354 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 355 to a coherent interconnect. 356 357 If a Cortex-A53 processor is executing a store or prefetch for 358 write instruction at the same time as a processor in another 359 cluster is executing a cache maintenance operation to the same 360 address, then this erratum might cause a clean cache line to be 361 incorrectly marked as dirty. 362 363 The workaround promotes data cache clean instructions to 364 data cache clean-and-invalidate. 365 Please note that this option does not necessarily enable the 366 workaround, as it depends on the alternative framework, which will 367 only patch the kernel if an affected CPU is detected. 368 369 If unsure, say Y. 370 371config ARM64_ERRATUM_819472 372 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 373 default y 374 select ARM64_WORKAROUND_CLEAN_CACHE 375 help 376 This option adds an alternative code sequence to work around ARM 377 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 378 present when it is connected to a coherent interconnect. 379 380 If the processor is executing a load and store exclusive sequence at 381 the same time as a processor in another cluster is executing a cache 382 maintenance operation to the same address, then this erratum might 383 cause data corruption. 384 385 The workaround promotes data cache clean instructions to 386 data cache clean-and-invalidate. 387 Please note that this does not necessarily enable the workaround, 388 as it depends on the alternative framework, which will only patch 389 the kernel if an affected CPU is detected. 390 391 If unsure, say Y. 392 393config ARM64_ERRATUM_832075 394 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 395 default y 396 help 397 This option adds an alternative code sequence to work around ARM 398 erratum 832075 on Cortex-A57 parts up to r1p2. 399 400 Affected Cortex-A57 parts might deadlock when exclusive load/store 401 instructions to Write-Back memory are mixed with Device loads. 402 403 The workaround is to promote device loads to use Load-Acquire 404 semantics. 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_834220 412 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 413 depends on KVM 414 default y 415 help 416 This option adds an alternative code sequence to work around ARM 417 erratum 834220 on Cortex-A57 parts up to r1p2. 418 419 Affected Cortex-A57 parts might report a Stage 2 translation 420 fault as the result of a Stage 1 fault for load crossing a 421 page boundary when there is a permission or device memory 422 alignment fault at Stage 1 and a translation fault at Stage 2. 423 424 The workaround is to verify that the Stage 1 translation 425 doesn't generate a fault before handling the Stage 2 fault. 426 Please note that this does not necessarily enable the workaround, 427 as it depends on the alternative framework, which will only patch 428 the kernel if an affected CPU is detected. 429 430 If unsure, say Y. 431 432config ARM64_ERRATUM_845719 433 bool "Cortex-A53: 845719: a load might read incorrect data" 434 depends on COMPAT 435 default y 436 help 437 This option adds an alternative code sequence to work around ARM 438 erratum 845719 on Cortex-A53 parts up to r0p4. 439 440 When running a compat (AArch32) userspace on an affected Cortex-A53 441 part, a load at EL0 from a virtual address that matches the bottom 32 442 bits of the virtual address used by a recent load at (AArch64) EL1 443 might return incorrect data. 444 445 The workaround is to write the contextidr_el1 register on exception 446 return to a 32-bit task. 447 Please note that this does not necessarily enable the workaround, 448 as it depends on the alternative framework, which will only patch 449 the kernel if an affected CPU is detected. 450 451 If unsure, say Y. 452 453config ARM64_ERRATUM_843419 454 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 455 default y 456 select ARM64_MODULE_PLTS if MODULES 457 help 458 This option links the kernel with '--fix-cortex-a53-843419' and 459 enables PLT support to replace certain ADRP instructions, which can 460 cause subsequent memory accesses to use an incorrect address on 461 Cortex-A53 parts up to r0p4. 462 463 If unsure, say Y. 464 465config ARM64_ERRATUM_1024718 466 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 467 default y 468 help 469 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 470 471 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 472 update of the hardware dirty bit when the DBM/AP bits are updated 473 without a break-before-make. The workaround is to disable the usage 474 of hardware DBM locally on the affected cores. CPUs not affected by 475 this erratum will continue to use the feature. 476 477 If unsure, say Y. 478 479config ARM64_ERRATUM_1188873 480 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 481 default y 482 depends on COMPAT 483 select ARM_ARCH_TIMER_OOL_WORKAROUND 484 help 485 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 486 erratum 1188873. 487 488 Affected Cortex-A76/Neoverse-N1 cores (r0p0, r1p0, r2p0) could 489 cause register corruption when accessing the timer registers 490 from AArch32 userspace. 491 492 If unsure, say Y. 493 494config ARM64_ERRATUM_1165522 495 bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 496 default y 497 help 498 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 499 500 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 501 corrupted TLBs by speculating an AT instruction during a guest 502 context switch. 503 504 If unsure, say Y. 505 506config ARM64_ERRATUM_1286807 507 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 508 default y 509 select ARM64_WORKAROUND_REPEAT_TLBI 510 help 511 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 512 513 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 514 address for a cacheable mapping of a location is being 515 accessed by a core while another core is remapping the virtual 516 address to a new physical page using the recommended 517 break-before-make sequence, then under very rare circumstances 518 TLBI+DSB completes before a read using the translation being 519 invalidated has been observed by other observers. The 520 workaround repeats the TLBI+DSB operation. 521 522 If unsure, say Y. 523 524config CAVIUM_ERRATUM_22375 525 bool "Cavium erratum 22375, 24313" 526 default y 527 help 528 Enable workaround for errata 22375 and 24313. 529 530 This implements two gicv3-its errata workarounds for ThunderX. Both 531 with a small impact affecting only ITS table allocation. 532 533 erratum 22375: only alloc 8MB table size 534 erratum 24313: ignore memory access type 535 536 The fixes are in ITS initialization and basically ignore memory access 537 type and table size provided by the TYPER and BASER registers. 538 539 If unsure, say Y. 540 541config CAVIUM_ERRATUM_23144 542 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 543 depends on NUMA 544 default y 545 help 546 ITS SYNC command hang for cross node io and collections/cpu mapping. 547 548 If unsure, say Y. 549 550config CAVIUM_ERRATUM_23154 551 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 552 default y 553 help 554 The gicv3 of ThunderX requires a modified version for 555 reading the IAR status to ensure data synchronization 556 (access to icc_iar1_el1 is not sync'ed before and after). 557 558 If unsure, say Y. 559 560config CAVIUM_ERRATUM_27456 561 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 562 default y 563 help 564 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 565 instructions may cause the icache to become corrupted if it 566 contains data for a non-current ASID. The fix is to 567 invalidate the icache when changing the mm context. 568 569 If unsure, say Y. 570 571config CAVIUM_ERRATUM_30115 572 bool "Cavium erratum 30115: Guest may disable interrupts in host" 573 default y 574 help 575 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 576 1.2, and T83 Pass 1.0, KVM guest execution may disable 577 interrupts in host. Trapping both GICv3 group-0 and group-1 578 accesses sidesteps the issue. 579 580 If unsure, say Y. 581 582config QCOM_FALKOR_ERRATUM_1003 583 bool "Falkor E1003: Incorrect translation due to ASID change" 584 default y 585 help 586 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 587 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 588 in TTBR1_EL1, this situation only occurs in the entry trampoline and 589 then only for entries in the walk cache, since the leaf translation 590 is unchanged. Work around the erratum by invalidating the walk cache 591 entries for the trampoline before entering the kernel proper. 592 593config ARM64_WORKAROUND_REPEAT_TLBI 594 bool 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 uses 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 a 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 affects 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 ARCH_ENABLE_SPLIT_PMD_PTLOCK 894 def_bool y if PGTABLE_LEVELS > 2 895 896config SECCOMP 897 bool "Enable seccomp to safely compute untrusted bytecode" 898 ---help--- 899 This kernel feature is useful for number crunching applications 900 that may need to compute untrusted bytecode during their 901 execution. By using pipes or other transports made available to 902 the process as file descriptors supporting the read/write 903 syscalls, it's possible to isolate those applications in 904 their own address space using seccomp. Once seccomp is 905 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 906 and the task is only allowed to execute a few safe syscalls 907 defined by each seccomp mode. 908 909config PARAVIRT 910 bool "Enable paravirtualization code" 911 help 912 This changes the kernel so it can modify itself when it is run 913 under a hypervisor, potentially improving performance significantly 914 over full virtualization. 915 916config PARAVIRT_TIME_ACCOUNTING 917 bool "Paravirtual steal time accounting" 918 select PARAVIRT 919 default n 920 help 921 Select this option to enable fine granularity task steal time 922 accounting. Time spent executing other tasks in parallel with 923 the current vCPU is discounted from the vCPU power. To account for 924 that, there can be a small performance impact. 925 926 If in doubt, say N here. 927 928config KEXEC 929 depends on PM_SLEEP_SMP 930 select KEXEC_CORE 931 bool "kexec system call" 932 ---help--- 933 kexec is a system call that implements the ability to shutdown your 934 current kernel, and to start another kernel. It is like a reboot 935 but it is independent of the system firmware. And like a reboot 936 you can start any kernel with it, not just Linux. 937 938config KEXEC_FILE 939 bool "kexec file based system call" 940 select KEXEC_CORE 941 help 942 This is new version of kexec system call. This system call is 943 file based and takes file descriptors as system call argument 944 for kernel and initramfs as opposed to list of segments as 945 accepted by previous system call. 946 947config KEXEC_VERIFY_SIG 948 bool "Verify kernel signature during kexec_file_load() syscall" 949 depends on KEXEC_FILE 950 help 951 Select this option to verify a signature with loaded kernel 952 image. If configured, any attempt of loading a image without 953 valid signature will fail. 954 955 In addition to that option, you need to enable signature 956 verification for the corresponding kernel image type being 957 loaded in order for this to work. 958 959config KEXEC_IMAGE_VERIFY_SIG 960 bool "Enable Image signature verification support" 961 default y 962 depends on KEXEC_VERIFY_SIG 963 depends on EFI && SIGNED_PE_FILE_VERIFICATION 964 help 965 Enable Image signature verification support. 966 967comment "Support for PE file signature verification disabled" 968 depends on KEXEC_VERIFY_SIG 969 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 970 971config CRASH_DUMP 972 bool "Build kdump crash kernel" 973 help 974 Generate crash dump after being started by kexec. This should 975 be normally only set in special crash dump kernels which are 976 loaded in the main kernel with kexec-tools into a specially 977 reserved region and then later executed after a crash by 978 kdump/kexec. 979 980 For more details see Documentation/kdump/kdump.txt 981 982config XEN_DOM0 983 def_bool y 984 depends on XEN 985 986config XEN 987 bool "Xen guest support on ARM64" 988 depends on ARM64 && OF 989 select SWIOTLB_XEN 990 select PARAVIRT 991 help 992 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 993 994config FORCE_MAX_ZONEORDER 995 int 996 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 997 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 998 default "11" 999 help 1000 The kernel memory allocator divides physically contiguous memory 1001 blocks into "zones", where each zone is a power of two number of 1002 pages. This option selects the largest power of two that the kernel 1003 keeps in the memory allocator. If you need to allocate very large 1004 blocks of physically contiguous memory, then you may need to 1005 increase this value. 1006 1007 This config option is actually maximum order plus one. For example, 1008 a value of 11 means that the largest free memory block is 2^10 pages. 1009 1010 We make sure that we can allocate upto a HugePage size for each configuration. 1011 Hence we have : 1012 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1013 1014 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1015 4M allocations matching the default size used by generic code. 1016 1017config UNMAP_KERNEL_AT_EL0 1018 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1019 default y 1020 help 1021 Speculation attacks against some high-performance processors can 1022 be used to bypass MMU permission checks and leak kernel data to 1023 userspace. This can be defended against by unmapping the kernel 1024 when running in userspace, mapping it back in on exception entry 1025 via a trampoline page in the vector table. 1026 1027 If unsure, say Y. 1028 1029config HARDEN_BRANCH_PREDICTOR 1030 bool "Harden the branch predictor against aliasing attacks" if EXPERT 1031 default y 1032 help 1033 Speculation attacks against some high-performance processors rely on 1034 being able to manipulate the branch predictor for a victim context by 1035 executing aliasing branches in the attacker context. Such attacks 1036 can be partially mitigated against by clearing internal branch 1037 predictor state and limiting the prediction logic in some situations. 1038 1039 This config option will take CPU-specific actions to harden the 1040 branch predictor against aliasing attacks and may rely on specific 1041 instruction sequences or control bits being set by the system 1042 firmware. 1043 1044 If unsure, say Y. 1045 1046config HARDEN_EL2_VECTORS 1047 bool "Harden EL2 vector mapping against system register leak" if EXPERT 1048 default y 1049 help 1050 Speculation attacks against some high-performance processors can 1051 be used to leak privileged information such as the vector base 1052 register, resulting in a potential defeat of the EL2 layout 1053 randomization. 1054 1055 This config option will map the vectors to a fixed location, 1056 independent of the EL2 code mapping, so that revealing VBAR_EL2 1057 to an attacker does not give away any extra information. This 1058 only gets enabled on affected CPUs. 1059 1060 If unsure, say Y. 1061 1062config ARM64_SSBD 1063 bool "Speculative Store Bypass Disable" if EXPERT 1064 default y 1065 help 1066 This enables mitigation of the bypassing of previous stores 1067 by speculative loads. 1068 1069 If unsure, say Y. 1070 1071config RODATA_FULL_DEFAULT_ENABLED 1072 bool "Apply r/o permissions of VM areas also to their linear aliases" 1073 default y 1074 help 1075 Apply read-only attributes of VM areas to the linear alias of 1076 the backing pages as well. This prevents code or read-only data 1077 from being modified (inadvertently or intentionally) via another 1078 mapping of the same memory page. This additional enhancement can 1079 be turned off at runtime by passing rodata=[off|on] (and turned on 1080 with rodata=full if this option is set to 'n') 1081 1082 This requires the linear region to be mapped down to pages, 1083 which may adversely affect performance in some cases. 1084 1085config ARM64_SW_TTBR0_PAN 1086 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1087 help 1088 Enabling this option prevents the kernel from accessing 1089 user-space memory directly by pointing TTBR0_EL1 to a reserved 1090 zeroed area and reserved ASID. The user access routines 1091 restore the valid TTBR0_EL1 temporarily. 1092 1093menuconfig COMPAT 1094 bool "Kernel support for 32-bit EL0" 1095 depends on ARM64_4K_PAGES || EXPERT 1096 select COMPAT_BINFMT_ELF if BINFMT_ELF 1097 select HAVE_UID16 1098 select OLD_SIGSUSPEND3 1099 select COMPAT_OLD_SIGACTION 1100 help 1101 This option enables support for a 32-bit EL0 running under a 64-bit 1102 kernel at EL1. AArch32-specific components such as system calls, 1103 the user helper functions, VFP support and the ptrace interface are 1104 handled appropriately by the kernel. 1105 1106 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1107 that you will only be able to execute AArch32 binaries that were compiled 1108 with page size aligned segments. 1109 1110 If you want to execute 32-bit userspace applications, say Y. 1111 1112if COMPAT 1113 1114config KUSER_HELPERS 1115 bool "Enable kuser helpers page for 32 bit applications" 1116 default y 1117 help 1118 Warning: disabling this option may break 32-bit user programs. 1119 1120 Provide kuser helpers to compat tasks. The kernel provides 1121 helper code to userspace in read only form at a fixed location 1122 to allow userspace to be independent of the CPU type fitted to 1123 the system. This permits binaries to be run on ARMv4 through 1124 to ARMv8 without modification. 1125 1126 See Documentation/arm/kernel_user_helpers.txt for details. 1127 1128 However, the fixed address nature of these helpers can be used 1129 by ROP (return orientated programming) authors when creating 1130 exploits. 1131 1132 If all of the binaries and libraries which run on your platform 1133 are built specifically for your platform, and make no use of 1134 these helpers, then you can turn this option off to hinder 1135 such exploits. However, in that case, if a binary or library 1136 relying on those helpers is run, it will not function correctly. 1137 1138 Say N here only if you are absolutely certain that you do not 1139 need these helpers; otherwise, the safe option is to say Y. 1140 1141 1142menuconfig ARMV8_DEPRECATED 1143 bool "Emulate deprecated/obsolete ARMv8 instructions" 1144 depends on SYSCTL 1145 help 1146 Legacy software support may require certain instructions 1147 that have been deprecated or obsoleted in the architecture. 1148 1149 Enable this config to enable selective emulation of these 1150 features. 1151 1152 If unsure, say Y 1153 1154if ARMV8_DEPRECATED 1155 1156config SWP_EMULATION 1157 bool "Emulate SWP/SWPB instructions" 1158 help 1159 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1160 they are always undefined. Say Y here to enable software 1161 emulation of these instructions for userspace using LDXR/STXR. 1162 1163 In some older versions of glibc [<=2.8] SWP is used during futex 1164 trylock() operations with the assumption that the code will not 1165 be preempted. This invalid assumption may be more likely to fail 1166 with SWP emulation enabled, leading to deadlock of the user 1167 application. 1168 1169 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1170 on an external transaction monitoring block called a global 1171 monitor to maintain update atomicity. If your system does not 1172 implement a global monitor, this option can cause programs that 1173 perform SWP operations to uncached memory to deadlock. 1174 1175 If unsure, say Y 1176 1177config CP15_BARRIER_EMULATION 1178 bool "Emulate CP15 Barrier instructions" 1179 help 1180 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1181 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1182 strongly recommended to use the ISB, DSB, and DMB 1183 instructions instead. 1184 1185 Say Y here to enable software emulation of these 1186 instructions for AArch32 userspace code. When this option is 1187 enabled, CP15 barrier usage is traced which can help 1188 identify software that needs updating. 1189 1190 If unsure, say Y 1191 1192config SETEND_EMULATION 1193 bool "Emulate SETEND instruction" 1194 help 1195 The SETEND instruction alters the data-endianness of the 1196 AArch32 EL0, and is deprecated in ARMv8. 1197 1198 Say Y here to enable software emulation of the instruction 1199 for AArch32 userspace code. 1200 1201 Note: All the cpus on the system must have mixed endian support at EL0 1202 for this feature to be enabled. If a new CPU - which doesn't support mixed 1203 endian - is hotplugged in after this feature has been enabled, there could 1204 be unexpected results in the applications. 1205 1206 If unsure, say Y 1207endif 1208 1209endif 1210 1211menu "ARMv8.1 architectural features" 1212 1213config ARM64_HW_AFDBM 1214 bool "Support for hardware updates of the Access and Dirty page flags" 1215 default y 1216 help 1217 The ARMv8.1 architecture extensions introduce support for 1218 hardware updates of the access and dirty information in page 1219 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1220 capable processors, accesses to pages with PTE_AF cleared will 1221 set this bit instead of raising an access flag fault. 1222 Similarly, writes to read-only pages with the DBM bit set will 1223 clear the read-only bit (AP[2]) instead of raising a 1224 permission fault. 1225 1226 Kernels built with this configuration option enabled continue 1227 to work on pre-ARMv8.1 hardware and the performance impact is 1228 minimal. If unsure, say Y. 1229 1230config ARM64_PAN 1231 bool "Enable support for Privileged Access Never (PAN)" 1232 default y 1233 help 1234 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1235 prevents the kernel or hypervisor from accessing user-space (EL0) 1236 memory directly. 1237 1238 Choosing this option will cause any unprotected (not using 1239 copy_to_user et al) memory access to fail with a permission fault. 1240 1241 The feature is detected at runtime, and will remain as a 'nop' 1242 instruction if the cpu does not implement the feature. 1243 1244config ARM64_LSE_ATOMICS 1245 bool "Atomic instructions" 1246 default y 1247 help 1248 As part of the Large System Extensions, ARMv8.1 introduces new 1249 atomic instructions that are designed specifically to scale in 1250 very large systems. 1251 1252 Say Y here to make use of these instructions for the in-kernel 1253 atomic routines. This incurs a small overhead on CPUs that do 1254 not support these instructions and requires the kernel to be 1255 built with binutils >= 2.25 in order for the new instructions 1256 to be used. 1257 1258config ARM64_VHE 1259 bool "Enable support for Virtualization Host Extensions (VHE)" 1260 default y 1261 help 1262 Virtualization Host Extensions (VHE) allow the kernel to run 1263 directly at EL2 (instead of EL1) on processors that support 1264 it. This leads to better performance for KVM, as they reduce 1265 the cost of the world switch. 1266 1267 Selecting this option allows the VHE feature to be detected 1268 at runtime, and does not affect processors that do not 1269 implement this feature. 1270 1271endmenu 1272 1273menu "ARMv8.2 architectural features" 1274 1275config ARM64_UAO 1276 bool "Enable support for User Access Override (UAO)" 1277 default y 1278 help 1279 User Access Override (UAO; part of the ARMv8.2 Extensions) 1280 causes the 'unprivileged' variant of the load/store instructions to 1281 be overridden to be privileged. 1282 1283 This option changes get_user() and friends to use the 'unprivileged' 1284 variant of the load/store instructions. This ensures that user-space 1285 really did have access to the supplied memory. When addr_limit is 1286 set to kernel memory the UAO bit will be set, allowing privileged 1287 access to kernel memory. 1288 1289 Choosing this option will cause copy_to_user() et al to use user-space 1290 memory permissions. 1291 1292 The feature is detected at runtime, the kernel will use the 1293 regular load/store instructions if the cpu does not implement the 1294 feature. 1295 1296config ARM64_PMEM 1297 bool "Enable support for persistent memory" 1298 select ARCH_HAS_PMEM_API 1299 select ARCH_HAS_UACCESS_FLUSHCACHE 1300 help 1301 Say Y to enable support for the persistent memory API based on the 1302 ARMv8.2 DCPoP feature. 1303 1304 The feature is detected at runtime, and the kernel will use DC CVAC 1305 operations if DC CVAP is not supported (following the behaviour of 1306 DC CVAP itself if the system does not define a point of persistence). 1307 1308config ARM64_RAS_EXTN 1309 bool "Enable support for RAS CPU Extensions" 1310 default y 1311 help 1312 CPUs that support the Reliability, Availability and Serviceability 1313 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1314 errors, classify them and report them to software. 1315 1316 On CPUs with these extensions system software can use additional 1317 barriers to determine if faults are pending and read the 1318 classification from a new set of registers. 1319 1320 Selecting this feature will allow the kernel to use these barriers 1321 and access the new registers if the system supports the extension. 1322 Platform RAS features may additionally depend on firmware support. 1323 1324config ARM64_CNP 1325 bool "Enable support for Common Not Private (CNP) translations" 1326 default y 1327 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1328 help 1329 Common Not Private (CNP) allows translation table entries to 1330 be shared between different PEs in the same inner shareable 1331 domain, so the hardware can use this fact to optimise the 1332 caching of such entries in the TLB. 1333 1334 Selecting this option allows the CNP feature to be detected 1335 at runtime, and does not affect PEs that do not implement 1336 this feature. 1337 1338endmenu 1339 1340menu "ARMv8.3 architectural features" 1341 1342config ARM64_PTR_AUTH 1343 bool "Enable support for pointer authentication" 1344 default y 1345 depends on !KVM || ARM64_VHE 1346 help 1347 Pointer authentication (part of the ARMv8.3 Extensions) provides 1348 instructions for signing and authenticating pointers against secret 1349 keys, which can be used to mitigate Return Oriented Programming (ROP) 1350 and other attacks. 1351 1352 This option enables these instructions at EL0 (i.e. for userspace). 1353 1354 Choosing this option will cause the kernel to initialise secret keys 1355 for each process at exec() time, with these keys being 1356 context-switched along with the process. 1357 1358 The feature is detected at runtime. If the feature is not present in 1359 hardware it will not be advertised to userspace/KVM guest nor will it 1360 be enabled. However, KVM guest also require VHE mode and hence 1361 CONFIG_ARM64_VHE=y option to use this feature. 1362 1363endmenu 1364 1365config ARM64_SVE 1366 bool "ARM Scalable Vector Extension support" 1367 default y 1368 depends on !KVM || ARM64_VHE 1369 help 1370 The Scalable Vector Extension (SVE) is an extension to the AArch64 1371 execution state which complements and extends the SIMD functionality 1372 of the base architecture to support much larger vectors and to enable 1373 additional vectorisation opportunities. 1374 1375 To enable use of this extension on CPUs that implement it, say Y. 1376 1377 On CPUs that support the SVE2 extensions, this option will enable 1378 those too. 1379 1380 Note that for architectural reasons, firmware _must_ implement SVE 1381 support when running on SVE capable hardware. The required support 1382 is present in: 1383 1384 * version 1.5 and later of the ARM Trusted Firmware 1385 * the AArch64 boot wrapper since commit 5e1261e08abf 1386 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1387 1388 For other firmware implementations, consult the firmware documentation 1389 or vendor. 1390 1391 If you need the kernel to boot on SVE-capable hardware with broken 1392 firmware, you may need to say N here until you get your firmware 1393 fixed. Otherwise, you may experience firmware panics or lockups when 1394 booting the kernel. If unsure and you are not observing these 1395 symptoms, you should assume that it is safe to say Y. 1396 1397 CPUs that support SVE are architecturally required to support the 1398 Virtualization Host Extensions (VHE), so the kernel makes no 1399 provision for supporting SVE alongside KVM without VHE enabled. 1400 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1401 KVM in the same kernel image. 1402 1403config ARM64_MODULE_PLTS 1404 bool 1405 select HAVE_MOD_ARCH_SPECIFIC 1406 1407config ARM64_PSEUDO_NMI 1408 bool "Support for NMI-like interrupts" 1409 select CONFIG_ARM_GIC_V3 1410 help 1411 Adds support for mimicking Non-Maskable Interrupts through the use of 1412 GIC interrupt priority. This support requires version 3 or later of 1413 ARM GIC. 1414 1415 This high priority configuration for interrupts needs to be 1416 explicitly enabled by setting the kernel parameter 1417 "irqchip.gicv3_pseudo_nmi" to 1. 1418 1419 If unsure, say N 1420 1421config RELOCATABLE 1422 bool 1423 help 1424 This builds the kernel as a Position Independent Executable (PIE), 1425 which retains all relocation metadata required to relocate the 1426 kernel binary at runtime to a different virtual address than the 1427 address it was linked at. 1428 Since AArch64 uses the RELA relocation format, this requires a 1429 relocation pass at runtime even if the kernel is loaded at the 1430 same address it was linked at. 1431 1432config RANDOMIZE_BASE 1433 bool "Randomize the address of the kernel image" 1434 select ARM64_MODULE_PLTS if MODULES 1435 select RELOCATABLE 1436 help 1437 Randomizes the virtual address at which the kernel image is 1438 loaded, as a security feature that deters exploit attempts 1439 relying on knowledge of the location of kernel internals. 1440 1441 It is the bootloader's job to provide entropy, by passing a 1442 random u64 value in /chosen/kaslr-seed at kernel entry. 1443 1444 When booting via the UEFI stub, it will invoke the firmware's 1445 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1446 to the kernel proper. In addition, it will randomise the physical 1447 location of the kernel Image as well. 1448 1449 If unsure, say N. 1450 1451config RANDOMIZE_MODULE_REGION_FULL 1452 bool "Randomize the module region over a 4 GB range" 1453 depends on RANDOMIZE_BASE 1454 default y 1455 help 1456 Randomizes the location of the module region inside a 4 GB window 1457 covering the core kernel. This way, it is less likely for modules 1458 to leak information about the location of core kernel data structures 1459 but it does imply that function calls between modules and the core 1460 kernel will need to be resolved via veneers in the module PLT. 1461 1462 When this option is not set, the module region will be randomized over 1463 a limited range that contains the [_stext, _etext] interval of the 1464 core kernel, so branch relocations are always in range. 1465 1466config CC_HAVE_STACKPROTECTOR_SYSREG 1467 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1468 1469config STACKPROTECTOR_PER_TASK 1470 def_bool y 1471 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1472 1473endmenu 1474 1475menu "Boot options" 1476 1477config ARM64_ACPI_PARKING_PROTOCOL 1478 bool "Enable support for the ARM64 ACPI parking protocol" 1479 depends on ACPI 1480 help 1481 Enable support for the ARM64 ACPI parking protocol. If disabled 1482 the kernel will not allow booting through the ARM64 ACPI parking 1483 protocol even if the corresponding data is present in the ACPI 1484 MADT table. 1485 1486config CMDLINE 1487 string "Default kernel command string" 1488 default "" 1489 help 1490 Provide a set of default command-line options at build time by 1491 entering them here. As a minimum, you should specify the the 1492 root device (e.g. root=/dev/nfs). 1493 1494config CMDLINE_FORCE 1495 bool "Always use the default kernel command string" 1496 help 1497 Always use the default kernel command string, even if the boot 1498 loader passes other arguments to the kernel. 1499 This is useful if you cannot or don't want to change the 1500 command-line options your boot loader passes to the kernel. 1501 1502config EFI_STUB 1503 bool 1504 1505config EFI 1506 bool "UEFI runtime support" 1507 depends on OF && !CPU_BIG_ENDIAN 1508 depends on KERNEL_MODE_NEON 1509 select ARCH_SUPPORTS_ACPI 1510 select LIBFDT 1511 select UCS2_STRING 1512 select EFI_PARAMS_FROM_FDT 1513 select EFI_RUNTIME_WRAPPERS 1514 select EFI_STUB 1515 select EFI_ARMSTUB 1516 default y 1517 help 1518 This option provides support for runtime services provided 1519 by UEFI firmware (such as non-volatile variables, realtime 1520 clock, and platform reset). A UEFI stub is also provided to 1521 allow the kernel to be booted as an EFI application. This 1522 is only useful on systems that have UEFI firmware. 1523 1524config DMI 1525 bool "Enable support for SMBIOS (DMI) tables" 1526 depends on EFI 1527 default y 1528 help 1529 This enables SMBIOS/DMI feature for systems. 1530 1531 This option is only useful on systems that have UEFI firmware. 1532 However, even with this option, the resultant kernel should 1533 continue to boot on existing non-UEFI platforms. 1534 1535endmenu 1536 1537config SYSVIPC_COMPAT 1538 def_bool y 1539 depends on COMPAT && SYSVIPC 1540 1541config ARCH_ENABLE_HUGEPAGE_MIGRATION 1542 def_bool y 1543 depends on HUGETLB_PAGE && MIGRATION 1544 1545menu "Power management options" 1546 1547source "kernel/power/Kconfig" 1548 1549config ARCH_HIBERNATION_POSSIBLE 1550 def_bool y 1551 depends on CPU_PM 1552 1553config ARCH_HIBERNATION_HEADER 1554 def_bool y 1555 depends on HIBERNATION 1556 1557config ARCH_SUSPEND_POSSIBLE 1558 def_bool y 1559 1560endmenu 1561 1562menu "CPU Power Management" 1563 1564source "drivers/cpuidle/Kconfig" 1565 1566source "drivers/cpufreq/Kconfig" 1567 1568endmenu 1569 1570source "drivers/firmware/Kconfig" 1571 1572source "drivers/acpi/Kconfig" 1573 1574source "arch/arm64/kvm/Kconfig" 1575 1576if CRYPTO 1577source "arch/arm64/crypto/Kconfig" 1578endif 1579