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_HAS_DEBUG_WX 13 select ARCH_BINFMT_ELF_STATE 14 select ARCH_HAS_CACHE_LINE_SIZE 15 select ARCH_HAS_DEBUG_VIRTUAL 16 select ARCH_HAS_DEBUG_VM_PGTABLE 17 select ARCH_HAS_DEVMEM_IS_ALLOWED 18 select ARCH_HAS_DMA_PREP_COHERENT 19 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 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_NON_OVERLAPPING_ADDRESS_SPACE 28 select ARCH_HAS_PTE_DEVMAP 29 select ARCH_HAS_PTE_SPECIAL 30 select ARCH_HAS_SETUP_DMA_OPS 31 select ARCH_HAS_SET_DIRECT_MAP 32 select ARCH_HAS_SET_MEMORY 33 select ARCH_STACKWALK 34 select ARCH_HAS_STRICT_KERNEL_RWX 35 select ARCH_HAS_STRICT_MODULE_RWX 36 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 37 select ARCH_HAS_SYNC_DMA_FOR_CPU 38 select ARCH_HAS_SYSCALL_WRAPPER 39 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 40 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 41 select ARCH_HAVE_ELF_PROT 42 select ARCH_HAVE_NMI_SAFE_CMPXCHG 43 select ARCH_INLINE_READ_LOCK if !PREEMPTION 44 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 45 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 46 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 47 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 48 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 49 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 50 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 51 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 52 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 53 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 54 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 55 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 56 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 57 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 58 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 59 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 60 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 61 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 62 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 63 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 64 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 65 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 66 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 67 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 68 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 69 select ARCH_KEEP_MEMBLOCK 70 select ARCH_USE_CMPXCHG_LOCKREF 71 select ARCH_USE_GNU_PROPERTY 72 select ARCH_USE_QUEUED_RWLOCKS 73 select ARCH_USE_QUEUED_SPINLOCKS 74 select ARCH_USE_SYM_ANNOTATIONS 75 select ARCH_SUPPORTS_MEMORY_FAILURE 76 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 77 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 78 select ARCH_SUPPORTS_LTO_CLANG_THIN 79 select ARCH_SUPPORTS_CFI_CLANG 80 select ARCH_SUPPORTS_ATOMIC_RMW 81 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) 82 select ARCH_SUPPORTS_NUMA_BALANCING 83 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 84 select ARCH_WANT_DEFAULT_BPF_JIT 85 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 86 select ARCH_WANT_FRAME_POINTERS 87 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 88 select ARCH_WANT_LD_ORPHAN_WARN 89 select ARCH_HAS_UBSAN_SANITIZE_ALL 90 select ARM_AMBA 91 select ARM_ARCH_TIMER 92 select ARM_GIC 93 select AUDIT_ARCH_COMPAT_GENERIC 94 select ARM_GIC_V2M if PCI 95 select ARM_GIC_V3 96 select ARM_GIC_V3_ITS if PCI 97 select ARM_PSCI_FW 98 select BUILDTIME_TABLE_SORT 99 select CLONE_BACKWARDS 100 select COMMON_CLK 101 select CPU_PM if (SUSPEND || CPU_IDLE) 102 select CRC32 103 select DCACHE_WORD_ACCESS 104 select DMA_DIRECT_REMAP 105 select EDAC_SUPPORT 106 select FRAME_POINTER 107 select GENERIC_ALLOCATOR 108 select GENERIC_ARCH_TOPOLOGY 109 select GENERIC_CLOCKEVENTS 110 select GENERIC_CLOCKEVENTS_BROADCAST 111 select GENERIC_CPU_AUTOPROBE 112 select GENERIC_CPU_VULNERABILITIES 113 select GENERIC_EARLY_IOREMAP 114 select GENERIC_IDLE_POLL_SETUP 115 select GENERIC_IRQ_IPI 116 select GENERIC_IRQ_MULTI_HANDLER 117 select GENERIC_IRQ_PROBE 118 select GENERIC_IRQ_SHOW 119 select GENERIC_IRQ_SHOW_LEVEL 120 select GENERIC_PCI_IOMAP 121 select GENERIC_PTDUMP 122 select GENERIC_SCHED_CLOCK 123 select GENERIC_SMP_IDLE_THREAD 124 select GENERIC_STRNCPY_FROM_USER 125 select GENERIC_STRNLEN_USER 126 select GENERIC_TIME_VSYSCALL 127 select GENERIC_GETTIMEOFDAY 128 select GENERIC_VDSO_TIME_NS 129 select HANDLE_DOMAIN_IRQ 130 select HARDIRQS_SW_RESEND 131 select HAVE_MOVE_PMD 132 select HAVE_PCI 133 select HAVE_ACPI_APEI if (ACPI && EFI) 134 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 135 select HAVE_ARCH_AUDITSYSCALL 136 select HAVE_ARCH_BITREVERSE 137 select HAVE_ARCH_COMPILER_H 138 select HAVE_ARCH_HUGE_VMAP 139 select HAVE_ARCH_JUMP_LABEL 140 select HAVE_ARCH_JUMP_LABEL_RELATIVE 141 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 142 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 143 select HAVE_ARCH_KGDB 144 select HAVE_ARCH_MMAP_RND_BITS 145 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 146 select HAVE_ARCH_PREL32_RELOCATIONS 147 select HAVE_ARCH_SECCOMP_FILTER 148 select HAVE_ARCH_STACKLEAK 149 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 150 select HAVE_ARCH_TRACEHOOK 151 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 152 select HAVE_ARCH_VMAP_STACK 153 select HAVE_ARM_SMCCC 154 select HAVE_ASM_MODVERSIONS 155 select HAVE_EBPF_JIT 156 select HAVE_C_RECORDMCOUNT 157 select HAVE_CMPXCHG_DOUBLE 158 select HAVE_CMPXCHG_LOCAL 159 select HAVE_CONTEXT_TRACKING 160 select HAVE_DEBUG_BUGVERBOSE 161 select HAVE_DEBUG_KMEMLEAK 162 select HAVE_DMA_CONTIGUOUS 163 select HAVE_DYNAMIC_FTRACE 164 select HAVE_DYNAMIC_FTRACE_WITH_REGS \ 165 if $(cc-option,-fpatchable-function-entry=2) 166 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 167 if DYNAMIC_FTRACE_WITH_REGS 168 select HAVE_EFFICIENT_UNALIGNED_ACCESS 169 select HAVE_FAST_GUP 170 select HAVE_FTRACE_MCOUNT_RECORD 171 select HAVE_FUNCTION_TRACER 172 select HAVE_FUNCTION_ERROR_INJECTION 173 select HAVE_FUNCTION_GRAPH_TRACER 174 select HAVE_GCC_PLUGINS 175 select HAVE_HW_BREAKPOINT if PERF_EVENTS 176 select HAVE_IRQ_TIME_ACCOUNTING 177 select HAVE_NMI 178 select HAVE_PATA_PLATFORM 179 select HAVE_PERF_EVENTS 180 select HAVE_PERF_REGS 181 select HAVE_PERF_USER_STACK_DUMP 182 select HAVE_REGS_AND_STACK_ACCESS_API 183 select HAVE_FUNCTION_ARG_ACCESS_API 184 select HAVE_FUTEX_CMPXCHG if FUTEX 185 select MMU_GATHER_RCU_TABLE_FREE 186 select HAVE_RSEQ 187 select HAVE_STACKPROTECTOR 188 select HAVE_SYSCALL_TRACEPOINTS 189 select HAVE_KPROBES 190 select HAVE_KRETPROBES 191 select HAVE_GENERIC_VDSO 192 select HOLES_IN_ZONE 193 select IOMMU_DMA if IOMMU_SUPPORT 194 select IRQ_DOMAIN 195 select IRQ_FORCED_THREADING 196 select MODULES_USE_ELF_RELA 197 select NEED_DMA_MAP_STATE 198 select NEED_SG_DMA_LENGTH 199 select OF 200 select OF_EARLY_FLATTREE 201 select PCI_DOMAINS_GENERIC if PCI 202 select PCI_ECAM if (ACPI && PCI) 203 select PCI_SYSCALL if PCI 204 select POWER_RESET 205 select POWER_SUPPLY 206 select SET_FS 207 select SPARSE_IRQ 208 select SWIOTLB 209 select SYSCTL_EXCEPTION_TRACE 210 select THREAD_INFO_IN_TASK 211 help 212 ARM 64-bit (AArch64) Linux support. 213 214config 64BIT 215 def_bool y 216 217config MMU 218 def_bool y 219 220config ARM64_PAGE_SHIFT 221 int 222 default 16 if ARM64_64K_PAGES 223 default 14 if ARM64_16K_PAGES 224 default 12 225 226config ARM64_CONT_PTE_SHIFT 227 int 228 default 5 if ARM64_64K_PAGES 229 default 7 if ARM64_16K_PAGES 230 default 4 231 232config ARM64_CONT_PMD_SHIFT 233 int 234 default 5 if ARM64_64K_PAGES 235 default 5 if ARM64_16K_PAGES 236 default 4 237 238config ARCH_MMAP_RND_BITS_MIN 239 default 14 if ARM64_64K_PAGES 240 default 16 if ARM64_16K_PAGES 241 default 18 242 243# max bits determined by the following formula: 244# VA_BITS - PAGE_SHIFT - 3 245config ARCH_MMAP_RND_BITS_MAX 246 default 19 if ARM64_VA_BITS=36 247 default 24 if ARM64_VA_BITS=39 248 default 27 if ARM64_VA_BITS=42 249 default 30 if ARM64_VA_BITS=47 250 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 251 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 252 default 33 if ARM64_VA_BITS=48 253 default 14 if ARM64_64K_PAGES 254 default 16 if ARM64_16K_PAGES 255 default 18 256 257config ARCH_MMAP_RND_COMPAT_BITS_MIN 258 default 7 if ARM64_64K_PAGES 259 default 9 if ARM64_16K_PAGES 260 default 11 261 262config ARCH_MMAP_RND_COMPAT_BITS_MAX 263 default 16 264 265config NO_IOPORT_MAP 266 def_bool y if !PCI 267 268config STACKTRACE_SUPPORT 269 def_bool y 270 271config ILLEGAL_POINTER_VALUE 272 hex 273 default 0xdead000000000000 274 275config LOCKDEP_SUPPORT 276 def_bool y 277 278config TRACE_IRQFLAGS_SUPPORT 279 def_bool y 280 281config GENERIC_BUG 282 def_bool y 283 depends on BUG 284 285config GENERIC_BUG_RELATIVE_POINTERS 286 def_bool y 287 depends on GENERIC_BUG 288 289config GENERIC_HWEIGHT 290 def_bool y 291 292config GENERIC_CSUM 293 def_bool y 294 295config GENERIC_CALIBRATE_DELAY 296 def_bool y 297 298config ZONE_DMA 299 bool "Support DMA zone" if EXPERT 300 default y 301 302config ZONE_DMA32 303 bool "Support DMA32 zone" if EXPERT 304 default y 305 306config ARCH_ENABLE_MEMORY_HOTPLUG 307 def_bool y 308 309config ARCH_ENABLE_MEMORY_HOTREMOVE 310 def_bool y 311 312config SMP 313 def_bool y 314 315config KERNEL_MODE_NEON 316 def_bool y 317 318config FIX_EARLYCON_MEM 319 def_bool y 320 321config PGTABLE_LEVELS 322 int 323 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 324 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 325 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 326 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 327 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 328 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 329 330config ARCH_SUPPORTS_UPROBES 331 def_bool y 332 333config ARCH_PROC_KCORE_TEXT 334 def_bool y 335 336config BROKEN_GAS_INST 337 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 338 339config KASAN_SHADOW_OFFSET 340 hex 341 depends on KASAN 342 default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 343 default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 344 default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 345 default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 346 default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 347 default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 348 default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 349 default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 350 default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 351 default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 352 default 0xffffffffffffffff 353 354source "arch/arm64/Kconfig.platforms" 355 356menu "Kernel Features" 357 358menu "ARM errata workarounds via the alternatives framework" 359 360config ARM64_WORKAROUND_CLEAN_CACHE 361 bool 362 363config ARM64_ERRATUM_826319 364 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 365 default y 366 select ARM64_WORKAROUND_CLEAN_CACHE 367 help 368 This option adds an alternative code sequence to work around ARM 369 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 370 AXI master interface and an L2 cache. 371 372 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 373 and is unable to accept a certain write via this interface, it will 374 not progress on read data presented on the read data channel and the 375 system can deadlock. 376 377 The workaround promotes data cache clean instructions to 378 data cache clean-and-invalidate. 379 Please note that this does not necessarily enable the workaround, 380 as it depends on the alternative framework, which will only patch 381 the kernel if an affected CPU is detected. 382 383 If unsure, say Y. 384 385config ARM64_ERRATUM_827319 386 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 387 default y 388 select ARM64_WORKAROUND_CLEAN_CACHE 389 help 390 This option adds an alternative code sequence to work around ARM 391 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 392 master interface and an L2 cache. 393 394 Under certain conditions this erratum can cause a clean line eviction 395 to occur at the same time as another transaction to the same address 396 on the AMBA 5 CHI interface, which can cause data corruption if the 397 interconnect reorders the two transactions. 398 399 The workaround promotes data cache clean instructions to 400 data cache clean-and-invalidate. 401 Please note that this does not necessarily enable the workaround, 402 as it depends on the alternative framework, which will only patch 403 the kernel if an affected CPU is detected. 404 405 If unsure, say Y. 406 407config ARM64_ERRATUM_824069 408 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 409 default y 410 select ARM64_WORKAROUND_CLEAN_CACHE 411 help 412 This option adds an alternative code sequence to work around ARM 413 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 414 to a coherent interconnect. 415 416 If a Cortex-A53 processor is executing a store or prefetch for 417 write instruction at the same time as a processor in another 418 cluster is executing a cache maintenance operation to the same 419 address, then this erratum might cause a clean cache line to be 420 incorrectly marked as dirty. 421 422 The workaround promotes data cache clean instructions to 423 data cache clean-and-invalidate. 424 Please note that this option does not necessarily enable the 425 workaround, as it depends on the alternative framework, which will 426 only patch the kernel if an affected CPU is detected. 427 428 If unsure, say Y. 429 430config ARM64_ERRATUM_819472 431 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 432 default y 433 select ARM64_WORKAROUND_CLEAN_CACHE 434 help 435 This option adds an alternative code sequence to work around ARM 436 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 437 present when it is connected to a coherent interconnect. 438 439 If the processor is executing a load and store exclusive sequence at 440 the same time as a processor in another cluster is executing a cache 441 maintenance operation to the same address, then this erratum might 442 cause data corruption. 443 444 The workaround promotes data cache clean instructions to 445 data cache clean-and-invalidate. 446 Please note that this does not necessarily enable the workaround, 447 as it depends on the alternative framework, which will only patch 448 the kernel if an affected CPU is detected. 449 450 If unsure, say Y. 451 452config ARM64_ERRATUM_832075 453 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 454 default y 455 help 456 This option adds an alternative code sequence to work around ARM 457 erratum 832075 on Cortex-A57 parts up to r1p2. 458 459 Affected Cortex-A57 parts might deadlock when exclusive load/store 460 instructions to Write-Back memory are mixed with Device loads. 461 462 The workaround is to promote device loads to use Load-Acquire 463 semantics. 464 Please note that this does not necessarily enable the workaround, 465 as it depends on the alternative framework, which will only patch 466 the kernel if an affected CPU is detected. 467 468 If unsure, say Y. 469 470config ARM64_ERRATUM_834220 471 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 472 depends on KVM 473 default y 474 help 475 This option adds an alternative code sequence to work around ARM 476 erratum 834220 on Cortex-A57 parts up to r1p2. 477 478 Affected Cortex-A57 parts might report a Stage 2 translation 479 fault as the result of a Stage 1 fault for load crossing a 480 page boundary when there is a permission or device memory 481 alignment fault at Stage 1 and a translation fault at Stage 2. 482 483 The workaround is to verify that the Stage 1 translation 484 doesn't generate a fault before handling the Stage 2 fault. 485 Please note that this does not necessarily enable the workaround, 486 as it depends on the alternative framework, which will only patch 487 the kernel if an affected CPU is detected. 488 489 If unsure, say Y. 490 491config ARM64_ERRATUM_1742098 492 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 493 depends on COMPAT 494 default y 495 help 496 This option removes the AES hwcap for aarch32 user-space to 497 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 498 499 Affected parts may corrupt the AES state if an interrupt is 500 taken between a pair of AES instructions. These instructions 501 are only present if the cryptography extensions are present. 502 All software should have a fallback implementation for CPUs 503 that don't implement the cryptography extensions. 504 505 If unsure, say Y. 506 507config ARM64_ERRATUM_845719 508 bool "Cortex-A53: 845719: a load might read incorrect data" 509 depends on COMPAT 510 default y 511 help 512 This option adds an alternative code sequence to work around ARM 513 erratum 845719 on Cortex-A53 parts up to r0p4. 514 515 When running a compat (AArch32) userspace on an affected Cortex-A53 516 part, a load at EL0 from a virtual address that matches the bottom 32 517 bits of the virtual address used by a recent load at (AArch64) EL1 518 might return incorrect data. 519 520 The workaround is to write the contextidr_el1 register on exception 521 return to a 32-bit task. 522 Please note that this does not necessarily enable the workaround, 523 as it depends on the alternative framework, which will only patch 524 the kernel if an affected CPU is detected. 525 526 If unsure, say Y. 527 528config ARM64_ERRATUM_843419 529 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 530 default y 531 select ARM64_MODULE_PLTS if MODULES 532 help 533 This option links the kernel with '--fix-cortex-a53-843419' and 534 enables PLT support to replace certain ADRP instructions, which can 535 cause subsequent memory accesses to use an incorrect address on 536 Cortex-A53 parts up to r0p4. 537 538 If unsure, say Y. 539 540config ARM64_ERRATUM_1024718 541 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 542 default y 543 help 544 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 545 546 Affected Cortex-A55 cores (all revisions) could cause incorrect 547 update of the hardware dirty bit when the DBM/AP bits are updated 548 without a break-before-make. The workaround is to disable the usage 549 of hardware DBM locally on the affected cores. CPUs not affected by 550 this erratum will continue to use the feature. 551 552 If unsure, say Y. 553 554config ARM64_ERRATUM_1418040 555 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 556 default y 557 depends on COMPAT 558 help 559 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 560 errata 1188873 and 1418040. 561 562 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 563 cause register corruption when accessing the timer registers 564 from AArch32 userspace. 565 566 If unsure, say Y. 567 568config ARM64_WORKAROUND_SPECULATIVE_AT 569 bool 570 571config ARM64_ERRATUM_1165522 572 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 573 default y 574 select ARM64_WORKAROUND_SPECULATIVE_AT 575 help 576 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 577 578 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 579 corrupted TLBs by speculating an AT instruction during a guest 580 context switch. 581 582 If unsure, say Y. 583 584config ARM64_ERRATUM_1319367 585 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 586 default y 587 select ARM64_WORKAROUND_SPECULATIVE_AT 588 help 589 This option adds work arounds for ARM Cortex-A57 erratum 1319537 590 and A72 erratum 1319367 591 592 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 593 speculating an AT instruction during a guest context switch. 594 595 If unsure, say Y. 596 597config ARM64_ERRATUM_1530923 598 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 599 default y 600 select ARM64_WORKAROUND_SPECULATIVE_AT 601 help 602 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 603 604 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 605 corrupted TLBs by speculating an AT instruction during a guest 606 context switch. 607 608 If unsure, say Y. 609 610config ARM64_WORKAROUND_REPEAT_TLBI 611 bool 612 613config ARM64_ERRATUM_1286807 614 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 615 default y 616 select ARM64_WORKAROUND_REPEAT_TLBI 617 help 618 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 619 620 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 621 address for a cacheable mapping of a location is being 622 accessed by a core while another core is remapping the virtual 623 address to a new physical page using the recommended 624 break-before-make sequence, then under very rare circumstances 625 TLBI+DSB completes before a read using the translation being 626 invalidated has been observed by other observers. The 627 workaround repeats the TLBI+DSB operation. 628 629config ARM64_ERRATUM_1463225 630 bool "Cortex-A76: Software Step might prevent interrupt recognition" 631 default y 632 help 633 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 634 635 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 636 of a system call instruction (SVC) can prevent recognition of 637 subsequent interrupts when software stepping is disabled in the 638 exception handler of the system call and either kernel debugging 639 is enabled or VHE is in use. 640 641 Work around the erratum by triggering a dummy step exception 642 when handling a system call from a task that is being stepped 643 in a VHE configuration of the kernel. 644 645 If unsure, say Y. 646 647config ARM64_ERRATUM_1542419 648 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 649 default y 650 help 651 This option adds a workaround for ARM Neoverse-N1 erratum 652 1542419. 653 654 Affected Neoverse-N1 cores could execute a stale instruction when 655 modified by another CPU. The workaround depends on a firmware 656 counterpart. 657 658 Workaround the issue by hiding the DIC feature from EL0. This 659 forces user-space to perform cache maintenance. 660 661 If unsure, say Y. 662 663config ARM64_ERRATUM_1508412 664 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 665 default y 666 help 667 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 668 669 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 670 of a store-exclusive or read of PAR_EL1 and a load with device or 671 non-cacheable memory attributes. The workaround depends on a firmware 672 counterpart. 673 674 KVM guests must also have the workaround implemented or they can 675 deadlock the system. 676 677 Work around the issue by inserting DMB SY barriers around PAR_EL1 678 register reads and warning KVM users. The DMB barrier is sufficient 679 to prevent a speculative PAR_EL1 read. 680 681 If unsure, say Y. 682 683config ARM64_ERRATUM_2457168 684 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 685 depends on ARM64_AMU_EXTN 686 default y 687 help 688 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 689 690 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 691 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 692 incorrectly giving a significantly higher output value. 693 694 Work around this problem by keeping the reference values of affected counters 695 to 0 thus signaling an error case. This effect is the same to firmware disabling 696 affected counters, in which case 0 will be returned when reading the disabled 697 counters. 698 699 If unsure, say Y. 700 701config CAVIUM_ERRATUM_22375 702 bool "Cavium erratum 22375, 24313" 703 default y 704 help 705 Enable workaround for errata 22375 and 24313. 706 707 This implements two gicv3-its errata workarounds for ThunderX. Both 708 with a small impact affecting only ITS table allocation. 709 710 erratum 22375: only alloc 8MB table size 711 erratum 24313: ignore memory access type 712 713 The fixes are in ITS initialization and basically ignore memory access 714 type and table size provided by the TYPER and BASER registers. 715 716 If unsure, say Y. 717 718config CAVIUM_ERRATUM_23144 719 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 720 depends on NUMA 721 default y 722 help 723 ITS SYNC command hang for cross node io and collections/cpu mapping. 724 725 If unsure, say Y. 726 727config CAVIUM_ERRATUM_23154 728 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 729 default y 730 help 731 The gicv3 of ThunderX requires a modified version for 732 reading the IAR status to ensure data synchronization 733 (access to icc_iar1_el1 is not sync'ed before and after). 734 735 If unsure, say Y. 736 737config CAVIUM_ERRATUM_27456 738 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 739 default y 740 help 741 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 742 instructions may cause the icache to become corrupted if it 743 contains data for a non-current ASID. The fix is to 744 invalidate the icache when changing the mm context. 745 746 If unsure, say Y. 747 748config CAVIUM_ERRATUM_30115 749 bool "Cavium erratum 30115: Guest may disable interrupts in host" 750 default y 751 help 752 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 753 1.2, and T83 Pass 1.0, KVM guest execution may disable 754 interrupts in host. Trapping both GICv3 group-0 and group-1 755 accesses sidesteps the issue. 756 757 If unsure, say Y. 758 759config CAVIUM_TX2_ERRATUM_219 760 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 761 default y 762 help 763 On Cavium ThunderX2, a load, store or prefetch instruction between a 764 TTBR update and the corresponding context synchronizing operation can 765 cause a spurious Data Abort to be delivered to any hardware thread in 766 the CPU core. 767 768 Work around the issue by avoiding the problematic code sequence and 769 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 770 trap handler performs the corresponding register access, skips the 771 instruction and ensures context synchronization by virtue of the 772 exception return. 773 774 If unsure, say Y. 775 776config FUJITSU_ERRATUM_010001 777 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 778 default y 779 help 780 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 781 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 782 accesses may cause undefined fault (Data abort, DFSC=0b111111). 783 This fault occurs under a specific hardware condition when a 784 load/store instruction performs an address translation using: 785 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 786 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 787 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 788 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 789 790 The workaround is to ensure these bits are clear in TCR_ELx. 791 The workaround only affects the Fujitsu-A64FX. 792 793 If unsure, say Y. 794 795config HISILICON_ERRATUM_161600802 796 bool "Hip07 161600802: Erroneous redistributor VLPI base" 797 default y 798 help 799 The HiSilicon Hip07 SoC uses the wrong redistributor base 800 when issued ITS commands such as VMOVP and VMAPP, and requires 801 a 128kB offset to be applied to the target address in this commands. 802 803 If unsure, say Y. 804 805config QCOM_FALKOR_ERRATUM_1003 806 bool "Falkor E1003: Incorrect translation due to ASID change" 807 default y 808 help 809 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 810 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 811 in TTBR1_EL1, this situation only occurs in the entry trampoline and 812 then only for entries in the walk cache, since the leaf translation 813 is unchanged. Work around the erratum by invalidating the walk cache 814 entries for the trampoline before entering the kernel proper. 815 816config QCOM_FALKOR_ERRATUM_1009 817 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 818 default y 819 select ARM64_WORKAROUND_REPEAT_TLBI 820 help 821 On Falkor v1, the CPU may prematurely complete a DSB following a 822 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 823 one more time to fix the issue. 824 825 If unsure, say Y. 826 827config QCOM_QDF2400_ERRATUM_0065 828 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 829 default y 830 help 831 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 832 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 833 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 834 835 If unsure, say Y. 836 837config QCOM_FALKOR_ERRATUM_E1041 838 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 839 default y 840 help 841 Falkor CPU may speculatively fetch instructions from an improper 842 memory location when MMU translation is changed from SCTLR_ELn[M]=1 843 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 844 845 If unsure, say Y. 846 847config SOCIONEXT_SYNQUACER_PREITS 848 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 849 default y 850 help 851 Socionext Synquacer SoCs implement a separate h/w block to generate 852 MSI doorbell writes with non-zero values for the device ID. 853 854 If unsure, say Y. 855 856endmenu 857 858 859choice 860 prompt "Page size" 861 default ARM64_4K_PAGES 862 help 863 Page size (translation granule) configuration. 864 865config ARM64_4K_PAGES 866 bool "4KB" 867 help 868 This feature enables 4KB pages support. 869 870config ARM64_16K_PAGES 871 bool "16KB" 872 help 873 The system will use 16KB pages support. AArch32 emulation 874 requires applications compiled with 16K (or a multiple of 16K) 875 aligned segments. 876 877config ARM64_64K_PAGES 878 bool "64KB" 879 help 880 This feature enables 64KB pages support (4KB by default) 881 allowing only two levels of page tables and faster TLB 882 look-up. AArch32 emulation requires applications compiled 883 with 64K aligned segments. 884 885endchoice 886 887choice 888 prompt "Virtual address space size" 889 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 890 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 891 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 892 help 893 Allows choosing one of multiple possible virtual address 894 space sizes. The level of translation table is determined by 895 a combination of page size and virtual address space size. 896 897config ARM64_VA_BITS_36 898 bool "36-bit" if EXPERT 899 depends on ARM64_16K_PAGES 900 901config ARM64_VA_BITS_39 902 bool "39-bit" 903 depends on ARM64_4K_PAGES 904 905config ARM64_VA_BITS_42 906 bool "42-bit" 907 depends on ARM64_64K_PAGES 908 909config ARM64_VA_BITS_47 910 bool "47-bit" 911 depends on ARM64_16K_PAGES 912 913config ARM64_VA_BITS_48 914 bool "48-bit" 915 916config ARM64_VA_BITS_52 917 bool "52-bit" 918 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 919 help 920 Enable 52-bit virtual addressing for userspace when explicitly 921 requested via a hint to mmap(). The kernel will also use 52-bit 922 virtual addresses for its own mappings (provided HW support for 923 this feature is available, otherwise it reverts to 48-bit). 924 925 NOTE: Enabling 52-bit virtual addressing in conjunction with 926 ARMv8.3 Pointer Authentication will result in the PAC being 927 reduced from 7 bits to 3 bits, which may have a significant 928 impact on its susceptibility to brute-force attacks. 929 930 If unsure, select 48-bit virtual addressing instead. 931 932endchoice 933 934config ARM64_FORCE_52BIT 935 bool "Force 52-bit virtual addresses for userspace" 936 depends on ARM64_VA_BITS_52 && EXPERT 937 help 938 For systems with 52-bit userspace VAs enabled, the kernel will attempt 939 to maintain compatibility with older software by providing 48-bit VAs 940 unless a hint is supplied to mmap. 941 942 This configuration option disables the 48-bit compatibility logic, and 943 forces all userspace addresses to be 52-bit on HW that supports it. One 944 should only enable this configuration option for stress testing userspace 945 memory management code. If unsure say N here. 946 947config ARM64_VA_BITS 948 int 949 default 36 if ARM64_VA_BITS_36 950 default 39 if ARM64_VA_BITS_39 951 default 42 if ARM64_VA_BITS_42 952 default 47 if ARM64_VA_BITS_47 953 default 48 if ARM64_VA_BITS_48 954 default 52 if ARM64_VA_BITS_52 955 956choice 957 prompt "Physical address space size" 958 default ARM64_PA_BITS_48 959 help 960 Choose the maximum physical address range that the kernel will 961 support. 962 963config ARM64_PA_BITS_48 964 bool "48-bit" 965 966config ARM64_PA_BITS_52 967 bool "52-bit (ARMv8.2)" 968 depends on ARM64_64K_PAGES 969 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 970 help 971 Enable support for a 52-bit physical address space, introduced as 972 part of the ARMv8.2-LPA extension. 973 974 With this enabled, the kernel will also continue to work on CPUs that 975 do not support ARMv8.2-LPA, but with some added memory overhead (and 976 minor performance overhead). 977 978endchoice 979 980config ARM64_PA_BITS 981 int 982 default 48 if ARM64_PA_BITS_48 983 default 52 if ARM64_PA_BITS_52 984 985choice 986 prompt "Endianness" 987 default CPU_LITTLE_ENDIAN 988 help 989 Select the endianness of data accesses performed by the CPU. Userspace 990 applications will need to be compiled and linked for the endianness 991 that is selected here. 992 993config CPU_BIG_ENDIAN 994 bool "Build big-endian kernel" 995 depends on !LD_IS_LLD || LLD_VERSION >= 130000 996 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 997 depends on AS_IS_GNU || AS_VERSION >= 150000 998 help 999 Say Y if you plan on running a kernel with a big-endian userspace. 1000 1001config CPU_LITTLE_ENDIAN 1002 bool "Build little-endian kernel" 1003 help 1004 Say Y if you plan on running a kernel with a little-endian userspace. 1005 This is usually the case for distributions targeting arm64. 1006 1007endchoice 1008 1009config SCHED_MC 1010 bool "Multi-core scheduler support" 1011 help 1012 Multi-core scheduler support improves the CPU scheduler's decision 1013 making when dealing with multi-core CPU chips at a cost of slightly 1014 increased overhead in some places. If unsure say N here. 1015 1016config SCHED_SMT 1017 bool "SMT scheduler support" 1018 help 1019 Improves the CPU scheduler's decision making when dealing with 1020 MultiThreading at a cost of slightly increased overhead in some 1021 places. If unsure say N here. 1022 1023config NR_CPUS 1024 int "Maximum number of CPUs (2-4096)" 1025 range 2 4096 1026 default "256" 1027 1028config HOTPLUG_CPU 1029 bool "Support for hot-pluggable CPUs" 1030 select GENERIC_IRQ_MIGRATION 1031 help 1032 Say Y here to experiment with turning CPUs off and on. CPUs 1033 can be controlled through /sys/devices/system/cpu. 1034 1035# Common NUMA Features 1036config NUMA 1037 bool "NUMA Memory Allocation and Scheduler Support" 1038 select ACPI_NUMA if ACPI 1039 select OF_NUMA 1040 help 1041 Enable NUMA (Non-Uniform Memory Access) support. 1042 1043 The kernel will try to allocate memory used by a CPU on the 1044 local memory of the CPU and add some more 1045 NUMA awareness to the kernel. 1046 1047config NODES_SHIFT 1048 int "Maximum NUMA Nodes (as a power of 2)" 1049 range 1 10 1050 default "4" 1051 depends on NEED_MULTIPLE_NODES 1052 help 1053 Specify the maximum number of NUMA Nodes available on the target 1054 system. Increases memory reserved to accommodate various tables. 1055 1056config USE_PERCPU_NUMA_NODE_ID 1057 def_bool y 1058 depends on NUMA 1059 1060config HAVE_SETUP_PER_CPU_AREA 1061 def_bool y 1062 depends on NUMA 1063 1064config NEED_PER_CPU_EMBED_FIRST_CHUNK 1065 def_bool y 1066 depends on NUMA 1067 1068source "kernel/Kconfig.hz" 1069 1070config ARCH_SUPPORTS_DEBUG_PAGEALLOC 1071 def_bool y 1072 1073config ARCH_SPARSEMEM_ENABLE 1074 def_bool y 1075 select SPARSEMEM_VMEMMAP_ENABLE 1076 1077config ARCH_SPARSEMEM_DEFAULT 1078 def_bool ARCH_SPARSEMEM_ENABLE 1079 1080config ARCH_SELECT_MEMORY_MODEL 1081 def_bool ARCH_SPARSEMEM_ENABLE 1082 1083config ARCH_FLATMEM_ENABLE 1084 def_bool !NUMA 1085 1086config HAVE_ARCH_PFN_VALID 1087 def_bool y 1088 1089config HW_PERF_EVENTS 1090 def_bool y 1091 depends on ARM_PMU 1092 1093config SYS_SUPPORTS_HUGETLBFS 1094 def_bool y 1095 1096config ARCH_WANT_HUGE_PMD_SHARE 1097 1098config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1099 def_bool y if PGTABLE_LEVELS > 2 1100 1101# Supported by clang >= 7.0 1102config CC_HAVE_SHADOW_CALL_STACK 1103 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1104 1105config PARAVIRT 1106 bool "Enable paravirtualization code" 1107 help 1108 This changes the kernel so it can modify itself when it is run 1109 under a hypervisor, potentially improving performance significantly 1110 over full virtualization. 1111 1112config PARAVIRT_TIME_ACCOUNTING 1113 bool "Paravirtual steal time accounting" 1114 select PARAVIRT 1115 help 1116 Select this option to enable fine granularity task steal time 1117 accounting. Time spent executing other tasks in parallel with 1118 the current vCPU is discounted from the vCPU power. To account for 1119 that, there can be a small performance impact. 1120 1121 If in doubt, say N here. 1122 1123config KEXEC 1124 depends on PM_SLEEP_SMP 1125 select KEXEC_CORE 1126 bool "kexec system call" 1127 help 1128 kexec is a system call that implements the ability to shutdown your 1129 current kernel, and to start another kernel. It is like a reboot 1130 but it is independent of the system firmware. And like a reboot 1131 you can start any kernel with it, not just Linux. 1132 1133config KEXEC_FILE 1134 bool "kexec file based system call" 1135 select KEXEC_CORE 1136 help 1137 This is new version of kexec system call. This system call is 1138 file based and takes file descriptors as system call argument 1139 for kernel and initramfs as opposed to list of segments as 1140 accepted by previous system call. 1141 1142config KEXEC_SIG 1143 bool "Verify kernel signature during kexec_file_load() syscall" 1144 depends on KEXEC_FILE 1145 help 1146 Select this option to verify a signature with loaded kernel 1147 image. If configured, any attempt of loading a image without 1148 valid signature will fail. 1149 1150 In addition to that option, you need to enable signature 1151 verification for the corresponding kernel image type being 1152 loaded in order for this to work. 1153 1154config KEXEC_IMAGE_VERIFY_SIG 1155 bool "Enable Image signature verification support" 1156 default y 1157 depends on KEXEC_SIG 1158 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1159 help 1160 Enable Image signature verification support. 1161 1162comment "Support for PE file signature verification disabled" 1163 depends on KEXEC_SIG 1164 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1165 1166config CRASH_DUMP 1167 bool "Build kdump crash kernel" 1168 help 1169 Generate crash dump after being started by kexec. This should 1170 be normally only set in special crash dump kernels which are 1171 loaded in the main kernel with kexec-tools into a specially 1172 reserved region and then later executed after a crash by 1173 kdump/kexec. 1174 1175 For more details see Documentation/admin-guide/kdump/kdump.rst 1176 1177config XEN_DOM0 1178 def_bool y 1179 depends on XEN 1180 1181config XEN 1182 bool "Xen guest support on ARM64" 1183 depends on ARM64 && OF 1184 select SWIOTLB_XEN 1185 select PARAVIRT 1186 help 1187 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1188 1189config FORCE_MAX_ZONEORDER 1190 int 1191 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 1192 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 1193 default "11" 1194 help 1195 The kernel memory allocator divides physically contiguous memory 1196 blocks into "zones", where each zone is a power of two number of 1197 pages. This option selects the largest power of two that the kernel 1198 keeps in the memory allocator. If you need to allocate very large 1199 blocks of physically contiguous memory, then you may need to 1200 increase this value. 1201 1202 This config option is actually maximum order plus one. For example, 1203 a value of 11 means that the largest free memory block is 2^10 pages. 1204 1205 We make sure that we can allocate upto a HugePage size for each configuration. 1206 Hence we have : 1207 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1208 1209 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1210 4M allocations matching the default size used by generic code. 1211 1212config UNMAP_KERNEL_AT_EL0 1213 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1214 default y 1215 help 1216 Speculation attacks against some high-performance processors can 1217 be used to bypass MMU permission checks and leak kernel data to 1218 userspace. This can be defended against by unmapping the kernel 1219 when running in userspace, mapping it back in on exception entry 1220 via a trampoline page in the vector table. 1221 1222 If unsure, say Y. 1223 1224config MITIGATE_SPECTRE_BRANCH_HISTORY 1225 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1226 default y 1227 help 1228 Speculation attacks against some high-performance processors can 1229 make use of branch history to influence future speculation. 1230 When taking an exception from user-space, a sequence of branches 1231 or a firmware call overwrites the branch history. 1232 1233config RODATA_FULL_DEFAULT_ENABLED 1234 bool "Apply r/o permissions of VM areas also to their linear aliases" 1235 default y 1236 help 1237 Apply read-only attributes of VM areas to the linear alias of 1238 the backing pages as well. This prevents code or read-only data 1239 from being modified (inadvertently or intentionally) via another 1240 mapping of the same memory page. This additional enhancement can 1241 be turned off at runtime by passing rodata=[off|on] (and turned on 1242 with rodata=full if this option is set to 'n') 1243 1244 This requires the linear region to be mapped down to pages, 1245 which may adversely affect performance in some cases. 1246 1247config ARM64_SW_TTBR0_PAN 1248 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1249 help 1250 Enabling this option prevents the kernel from accessing 1251 user-space memory directly by pointing TTBR0_EL1 to a reserved 1252 zeroed area and reserved ASID. The user access routines 1253 restore the valid TTBR0_EL1 temporarily. 1254 1255config ARM64_TAGGED_ADDR_ABI 1256 bool "Enable the tagged user addresses syscall ABI" 1257 default y 1258 help 1259 When this option is enabled, user applications can opt in to a 1260 relaxed ABI via prctl() allowing tagged addresses to be passed 1261 to system calls as pointer arguments. For details, see 1262 Documentation/arm64/tagged-address-abi.rst. 1263 1264menuconfig COMPAT 1265 bool "Kernel support for 32-bit EL0" 1266 depends on ARM64_4K_PAGES || EXPERT 1267 select COMPAT_BINFMT_ELF if BINFMT_ELF 1268 select HAVE_UID16 1269 select OLD_SIGSUSPEND3 1270 select COMPAT_OLD_SIGACTION 1271 help 1272 This option enables support for a 32-bit EL0 running under a 64-bit 1273 kernel at EL1. AArch32-specific components such as system calls, 1274 the user helper functions, VFP support and the ptrace interface are 1275 handled appropriately by the kernel. 1276 1277 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1278 that you will only be able to execute AArch32 binaries that were compiled 1279 with page size aligned segments. 1280 1281 If you want to execute 32-bit userspace applications, say Y. 1282 1283if COMPAT 1284 1285config KUSER_HELPERS 1286 bool "Enable kuser helpers page for 32-bit applications" 1287 default y 1288 help 1289 Warning: disabling this option may break 32-bit user programs. 1290 1291 Provide kuser helpers to compat tasks. The kernel provides 1292 helper code to userspace in read only form at a fixed location 1293 to allow userspace to be independent of the CPU type fitted to 1294 the system. This permits binaries to be run on ARMv4 through 1295 to ARMv8 without modification. 1296 1297 See Documentation/arm/kernel_user_helpers.rst for details. 1298 1299 However, the fixed address nature of these helpers can be used 1300 by ROP (return orientated programming) authors when creating 1301 exploits. 1302 1303 If all of the binaries and libraries which run on your platform 1304 are built specifically for your platform, and make no use of 1305 these helpers, then you can turn this option off to hinder 1306 such exploits. However, in that case, if a binary or library 1307 relying on those helpers is run, it will not function correctly. 1308 1309 Say N here only if you are absolutely certain that you do not 1310 need these helpers; otherwise, the safe option is to say Y. 1311 1312config COMPAT_VDSO 1313 bool "Enable vDSO for 32-bit applications" 1314 depends on !CPU_BIG_ENDIAN 1315 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1316 select GENERIC_COMPAT_VDSO 1317 default y 1318 help 1319 Place in the process address space of 32-bit applications an 1320 ELF shared object providing fast implementations of gettimeofday 1321 and clock_gettime. 1322 1323 You must have a 32-bit build of glibc 2.22 or later for programs 1324 to seamlessly take advantage of this. 1325 1326config THUMB2_COMPAT_VDSO 1327 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1328 depends on COMPAT_VDSO 1329 default y 1330 help 1331 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1332 otherwise with '-marm'. 1333 1334menuconfig ARMV8_DEPRECATED 1335 bool "Emulate deprecated/obsolete ARMv8 instructions" 1336 depends on SYSCTL 1337 help 1338 Legacy software support may require certain instructions 1339 that have been deprecated or obsoleted in the architecture. 1340 1341 Enable this config to enable selective emulation of these 1342 features. 1343 1344 If unsure, say Y 1345 1346if ARMV8_DEPRECATED 1347 1348config SWP_EMULATION 1349 bool "Emulate SWP/SWPB instructions" 1350 help 1351 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1352 they are always undefined. Say Y here to enable software 1353 emulation of these instructions for userspace using LDXR/STXR. 1354 This feature can be controlled at runtime with the abi.swp 1355 sysctl which is disabled by default. 1356 1357 In some older versions of glibc [<=2.8] SWP is used during futex 1358 trylock() operations with the assumption that the code will not 1359 be preempted. This invalid assumption may be more likely to fail 1360 with SWP emulation enabled, leading to deadlock of the user 1361 application. 1362 1363 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1364 on an external transaction monitoring block called a global 1365 monitor to maintain update atomicity. If your system does not 1366 implement a global monitor, this option can cause programs that 1367 perform SWP operations to uncached memory to deadlock. 1368 1369 If unsure, say Y 1370 1371config CP15_BARRIER_EMULATION 1372 bool "Emulate CP15 Barrier instructions" 1373 help 1374 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1375 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1376 strongly recommended to use the ISB, DSB, and DMB 1377 instructions instead. 1378 1379 Say Y here to enable software emulation of these 1380 instructions for AArch32 userspace code. When this option is 1381 enabled, CP15 barrier usage is traced which can help 1382 identify software that needs updating. This feature can be 1383 controlled at runtime with the abi.cp15_barrier sysctl. 1384 1385 If unsure, say Y 1386 1387config SETEND_EMULATION 1388 bool "Emulate SETEND instruction" 1389 help 1390 The SETEND instruction alters the data-endianness of the 1391 AArch32 EL0, and is deprecated in ARMv8. 1392 1393 Say Y here to enable software emulation of the instruction 1394 for AArch32 userspace code. This feature can be controlled 1395 at runtime with the abi.setend sysctl. 1396 1397 Note: All the cpus on the system must have mixed endian support at EL0 1398 for this feature to be enabled. If a new CPU - which doesn't support mixed 1399 endian - is hotplugged in after this feature has been enabled, there could 1400 be unexpected results in the applications. 1401 1402 If unsure, say Y 1403endif 1404 1405endif 1406 1407menu "ARMv8.1 architectural features" 1408 1409config ARM64_HW_AFDBM 1410 bool "Support for hardware updates of the Access and Dirty page flags" 1411 default y 1412 help 1413 The ARMv8.1 architecture extensions introduce support for 1414 hardware updates of the access and dirty information in page 1415 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1416 capable processors, accesses to pages with PTE_AF cleared will 1417 set this bit instead of raising an access flag fault. 1418 Similarly, writes to read-only pages with the DBM bit set will 1419 clear the read-only bit (AP[2]) instead of raising a 1420 permission fault. 1421 1422 Kernels built with this configuration option enabled continue 1423 to work on pre-ARMv8.1 hardware and the performance impact is 1424 minimal. If unsure, say Y. 1425 1426config ARM64_PAN 1427 bool "Enable support for Privileged Access Never (PAN)" 1428 default y 1429 help 1430 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1431 prevents the kernel or hypervisor from accessing user-space (EL0) 1432 memory directly. 1433 1434 Choosing this option will cause any unprotected (not using 1435 copy_to_user et al) memory access to fail with a permission fault. 1436 1437 The feature is detected at runtime, and will remain as a 'nop' 1438 instruction if the cpu does not implement the feature. 1439 1440config AS_HAS_LSE_ATOMICS 1441 def_bool $(as-instr,.arch_extension lse) 1442 1443config ARM64_LSE_ATOMICS 1444 bool 1445 default ARM64_USE_LSE_ATOMICS 1446 depends on AS_HAS_LSE_ATOMICS 1447 1448config ARM64_USE_LSE_ATOMICS 1449 bool "Atomic instructions" 1450 depends on JUMP_LABEL 1451 default y 1452 help 1453 As part of the Large System Extensions, ARMv8.1 introduces new 1454 atomic instructions that are designed specifically to scale in 1455 very large systems. 1456 1457 Say Y here to make use of these instructions for the in-kernel 1458 atomic routines. This incurs a small overhead on CPUs that do 1459 not support these instructions and requires the kernel to be 1460 built with binutils >= 2.25 in order for the new instructions 1461 to be used. 1462 1463config ARM64_VHE 1464 bool "Enable support for Virtualization Host Extensions (VHE)" 1465 default y 1466 help 1467 Virtualization Host Extensions (VHE) allow the kernel to run 1468 directly at EL2 (instead of EL1) on processors that support 1469 it. This leads to better performance for KVM, as they reduce 1470 the cost of the world switch. 1471 1472 Selecting this option allows the VHE feature to be detected 1473 at runtime, and does not affect processors that do not 1474 implement this feature. 1475 1476endmenu 1477 1478menu "ARMv8.2 architectural features" 1479 1480config ARM64_UAO 1481 bool "Enable support for User Access Override (UAO)" 1482 default y 1483 help 1484 User Access Override (UAO; part of the ARMv8.2 Extensions) 1485 causes the 'unprivileged' variant of the load/store instructions to 1486 be overridden to be privileged. 1487 1488 This option changes get_user() and friends to use the 'unprivileged' 1489 variant of the load/store instructions. This ensures that user-space 1490 really did have access to the supplied memory. When addr_limit is 1491 set to kernel memory the UAO bit will be set, allowing privileged 1492 access to kernel memory. 1493 1494 Choosing this option will cause copy_to_user() et al to use user-space 1495 memory permissions. 1496 1497 The feature is detected at runtime, the kernel will use the 1498 regular load/store instructions if the cpu does not implement the 1499 feature. 1500 1501config ARM64_PMEM 1502 bool "Enable support for persistent memory" 1503 select ARCH_HAS_PMEM_API 1504 select ARCH_HAS_UACCESS_FLUSHCACHE 1505 help 1506 Say Y to enable support for the persistent memory API based on the 1507 ARMv8.2 DCPoP feature. 1508 1509 The feature is detected at runtime, and the kernel will use DC CVAC 1510 operations if DC CVAP is not supported (following the behaviour of 1511 DC CVAP itself if the system does not define a point of persistence). 1512 1513config ARM64_RAS_EXTN 1514 bool "Enable support for RAS CPU Extensions" 1515 default y 1516 help 1517 CPUs that support the Reliability, Availability and Serviceability 1518 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1519 errors, classify them and report them to software. 1520 1521 On CPUs with these extensions system software can use additional 1522 barriers to determine if faults are pending and read the 1523 classification from a new set of registers. 1524 1525 Selecting this feature will allow the kernel to use these barriers 1526 and access the new registers if the system supports the extension. 1527 Platform RAS features may additionally depend on firmware support. 1528 1529config ARM64_CNP 1530 bool "Enable support for Common Not Private (CNP) translations" 1531 default y 1532 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1533 help 1534 Common Not Private (CNP) allows translation table entries to 1535 be shared between different PEs in the same inner shareable 1536 domain, so the hardware can use this fact to optimise the 1537 caching of such entries in the TLB. 1538 1539 Selecting this option allows the CNP feature to be detected 1540 at runtime, and does not affect PEs that do not implement 1541 this feature. 1542 1543endmenu 1544 1545menu "ARMv8.3 architectural features" 1546 1547config ARM64_PTR_AUTH 1548 bool "Enable support for pointer authentication" 1549 default y 1550 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1551 # Modern compilers insert a .note.gnu.property section note for PAC 1552 # which is only understood by binutils starting with version 2.33.1. 1553 depends on LD_IS_LLD || LD_VERSION >= 233010000 || (CC_IS_GCC && GCC_VERSION < 90100) 1554 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1555 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1556 help 1557 Pointer authentication (part of the ARMv8.3 Extensions) provides 1558 instructions for signing and authenticating pointers against secret 1559 keys, which can be used to mitigate Return Oriented Programming (ROP) 1560 and other attacks. 1561 1562 This option enables these instructions at EL0 (i.e. for userspace). 1563 Choosing this option will cause the kernel to initialise secret keys 1564 for each process at exec() time, with these keys being 1565 context-switched along with the process. 1566 1567 If the compiler supports the -mbranch-protection or 1568 -msign-return-address flag (e.g. GCC 7 or later), then this option 1569 will also cause the kernel itself to be compiled with return address 1570 protection. In this case, and if the target hardware is known to 1571 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1572 disabled with minimal loss of protection. 1573 1574 The feature is detected at runtime. If the feature is not present in 1575 hardware it will not be advertised to userspace/KVM guest nor will it 1576 be enabled. 1577 1578 If the feature is present on the boot CPU but not on a late CPU, then 1579 the late CPU will be parked. Also, if the boot CPU does not have 1580 address auth and the late CPU has then the late CPU will still boot 1581 but with the feature disabled. On such a system, this option should 1582 not be selected. 1583 1584 This feature works with FUNCTION_GRAPH_TRACER option only if 1585 DYNAMIC_FTRACE_WITH_REGS is enabled. 1586 1587config CC_HAS_BRANCH_PROT_PAC_RET 1588 # GCC 9 or later, clang 8 or later 1589 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1590 1591config CC_HAS_SIGN_RETURN_ADDRESS 1592 # GCC 7, 8 1593 def_bool $(cc-option,-msign-return-address=all) 1594 1595config AS_HAS_PAC 1596 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1597 1598config AS_HAS_CFI_NEGATE_RA_STATE 1599 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1600 1601endmenu 1602 1603menu "ARMv8.4 architectural features" 1604 1605config ARM64_AMU_EXTN 1606 bool "Enable support for the Activity Monitors Unit CPU extension" 1607 default y 1608 help 1609 The activity monitors extension is an optional extension introduced 1610 by the ARMv8.4 CPU architecture. This enables support for version 1 1611 of the activity monitors architecture, AMUv1. 1612 1613 To enable the use of this extension on CPUs that implement it, say Y. 1614 1615 Note that for architectural reasons, firmware _must_ implement AMU 1616 support when running on CPUs that present the activity monitors 1617 extension. The required support is present in: 1618 * Version 1.5 and later of the ARM Trusted Firmware 1619 1620 For kernels that have this configuration enabled but boot with broken 1621 firmware, you may need to say N here until the firmware is fixed. 1622 Otherwise you may experience firmware panics or lockups when 1623 accessing the counter registers. Even if you are not observing these 1624 symptoms, the values returned by the register reads might not 1625 correctly reflect reality. Most commonly, the value read will be 0, 1626 indicating that the counter is not enabled. 1627 1628config AS_HAS_ARMV8_4 1629 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1630 1631config ARM64_TLB_RANGE 1632 bool "Enable support for tlbi range feature" 1633 default y 1634 depends on AS_HAS_ARMV8_4 1635 help 1636 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1637 range of input addresses. 1638 1639 The feature introduces new assembly instructions, and they were 1640 support when binutils >= 2.30. 1641 1642endmenu 1643 1644menu "ARMv8.5 architectural features" 1645 1646config ARM64_BTI 1647 bool "Branch Target Identification support" 1648 default y 1649 help 1650 Branch Target Identification (part of the ARMv8.5 Extensions) 1651 provides a mechanism to limit the set of locations to which computed 1652 branch instructions such as BR or BLR can jump. 1653 1654 To make use of BTI on CPUs that support it, say Y. 1655 1656 BTI is intended to provide complementary protection to other control 1657 flow integrity protection mechanisms, such as the Pointer 1658 authentication mechanism provided as part of the ARMv8.3 Extensions. 1659 For this reason, it does not make sense to enable this option without 1660 also enabling support for pointer authentication. Thus, when 1661 enabling this option you should also select ARM64_PTR_AUTH=y. 1662 1663 Userspace binaries must also be specifically compiled to make use of 1664 this mechanism. If you say N here or the hardware does not support 1665 BTI, such binaries can still run, but you get no additional 1666 enforcement of branch destinations. 1667 1668config ARM64_BTI_KERNEL 1669 bool "Use Branch Target Identification for kernel" 1670 default y 1671 depends on ARM64_BTI 1672 depends on ARM64_PTR_AUTH 1673 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1674 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1675 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1676 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1677 depends on !CC_IS_GCC 1678 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1679 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1680 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1681 help 1682 Build the kernel with Branch Target Identification annotations 1683 and enable enforcement of this for kernel code. When this option 1684 is enabled and the system supports BTI all kernel code including 1685 modular code must have BTI enabled. 1686 1687config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1688 # GCC 9 or later, clang 8 or later 1689 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1690 1691config ARM64_E0PD 1692 bool "Enable support for E0PD" 1693 default y 1694 help 1695 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1696 that EL0 accesses made via TTBR1 always fault in constant time, 1697 providing similar benefits to KASLR as those provided by KPTI, but 1698 with lower overhead and without disrupting legitimate access to 1699 kernel memory such as SPE. 1700 1701 This option enables E0PD for TTBR1 where available. 1702 1703config ARCH_RANDOM 1704 bool "Enable support for random number generation" 1705 default y 1706 help 1707 Random number generation (part of the ARMv8.5 Extensions) 1708 provides a high bandwidth, cryptographically secure 1709 hardware random number generator. 1710 1711config ARM64_AS_HAS_MTE 1712 # Initial support for MTE went in binutils 2.32.0, checked with 1713 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1714 # as a late addition to the final architecture spec (LDGM/STGM) 1715 # is only supported in the newer 2.32.x and 2.33 binutils 1716 # versions, hence the extra "stgm" instruction check below. 1717 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1718 1719config ARM64_MTE 1720 bool "Memory Tagging Extension support" 1721 default y 1722 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1723 depends on AS_HAS_LSE_ATOMICS 1724 select ARCH_USES_HIGH_VMA_FLAGS 1725 help 1726 Memory Tagging (part of the ARMv8.5 Extensions) provides 1727 architectural support for run-time, always-on detection of 1728 various classes of memory error to aid with software debugging 1729 to eliminate vulnerabilities arising from memory-unsafe 1730 languages. 1731 1732 This option enables the support for the Memory Tagging 1733 Extension at EL0 (i.e. for userspace). 1734 1735 Selecting this option allows the feature to be detected at 1736 runtime. Any secondary CPU not implementing this feature will 1737 not be allowed a late bring-up. 1738 1739 Userspace binaries that want to use this feature must 1740 explicitly opt in. The mechanism for the userspace is 1741 described in: 1742 1743 Documentation/arm64/memory-tagging-extension.rst. 1744 1745endmenu 1746 1747config ARM64_SVE 1748 bool "ARM Scalable Vector Extension support" 1749 default y 1750 depends on !KVM || ARM64_VHE 1751 help 1752 The Scalable Vector Extension (SVE) is an extension to the AArch64 1753 execution state which complements and extends the SIMD functionality 1754 of the base architecture to support much larger vectors and to enable 1755 additional vectorisation opportunities. 1756 1757 To enable use of this extension on CPUs that implement it, say Y. 1758 1759 On CPUs that support the SVE2 extensions, this option will enable 1760 those too. 1761 1762 Note that for architectural reasons, firmware _must_ implement SVE 1763 support when running on SVE capable hardware. The required support 1764 is present in: 1765 1766 * version 1.5 and later of the ARM Trusted Firmware 1767 * the AArch64 boot wrapper since commit 5e1261e08abf 1768 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1769 1770 For other firmware implementations, consult the firmware documentation 1771 or vendor. 1772 1773 If you need the kernel to boot on SVE-capable hardware with broken 1774 firmware, you may need to say N here until you get your firmware 1775 fixed. Otherwise, you may experience firmware panics or lockups when 1776 booting the kernel. If unsure and you are not observing these 1777 symptoms, you should assume that it is safe to say Y. 1778 1779 CPUs that support SVE are architecturally required to support the 1780 Virtualization Host Extensions (VHE), so the kernel makes no 1781 provision for supporting SVE alongside KVM without VHE enabled. 1782 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1783 KVM in the same kernel image. 1784 1785config ARM64_MODULE_PLTS 1786 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1787 depends on MODULES 1788 select HAVE_MOD_ARCH_SPECIFIC 1789 help 1790 Allocate PLTs when loading modules so that jumps and calls whose 1791 targets are too far away for their relative offsets to be encoded 1792 in the instructions themselves can be bounced via veneers in the 1793 module's PLT. This allows modules to be allocated in the generic 1794 vmalloc area after the dedicated module memory area has been 1795 exhausted. 1796 1797 When running with address space randomization (KASLR), the module 1798 region itself may be too far away for ordinary relative jumps and 1799 calls, and so in that case, module PLTs are required and cannot be 1800 disabled. 1801 1802 Specific errata workaround(s) might also force module PLTs to be 1803 enabled (ARM64_ERRATUM_843419). 1804 1805config ARM64_PSEUDO_NMI 1806 bool "Support for NMI-like interrupts" 1807 select ARM_GIC_V3 1808 help 1809 Adds support for mimicking Non-Maskable Interrupts through the use of 1810 GIC interrupt priority. This support requires version 3 or later of 1811 ARM GIC. 1812 1813 This high priority configuration for interrupts needs to be 1814 explicitly enabled by setting the kernel parameter 1815 "irqchip.gicv3_pseudo_nmi" to 1. 1816 1817 If unsure, say N 1818 1819if ARM64_PSEUDO_NMI 1820config ARM64_DEBUG_PRIORITY_MASKING 1821 bool "Debug interrupt priority masking" 1822 help 1823 This adds runtime checks to functions enabling/disabling 1824 interrupts when using priority masking. The additional checks verify 1825 the validity of ICC_PMR_EL1 when calling concerned functions. 1826 1827 If unsure, say N 1828endif 1829 1830config RELOCATABLE 1831 bool "Build a relocatable kernel image" if EXPERT 1832 select ARCH_HAS_RELR 1833 default y 1834 help 1835 This builds the kernel as a Position Independent Executable (PIE), 1836 which retains all relocation metadata required to relocate the 1837 kernel binary at runtime to a different virtual address than the 1838 address it was linked at. 1839 Since AArch64 uses the RELA relocation format, this requires a 1840 relocation pass at runtime even if the kernel is loaded at the 1841 same address it was linked at. 1842 1843config RANDOMIZE_BASE 1844 bool "Randomize the address of the kernel image" 1845 select ARM64_MODULE_PLTS if MODULES 1846 select RELOCATABLE 1847 help 1848 Randomizes the virtual address at which the kernel image is 1849 loaded, as a security feature that deters exploit attempts 1850 relying on knowledge of the location of kernel internals. 1851 1852 It is the bootloader's job to provide entropy, by passing a 1853 random u64 value in /chosen/kaslr-seed at kernel entry. 1854 1855 When booting via the UEFI stub, it will invoke the firmware's 1856 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1857 to the kernel proper. In addition, it will randomise the physical 1858 location of the kernel Image as well. 1859 1860 If unsure, say N. 1861 1862config RANDOMIZE_MODULE_REGION_FULL 1863 bool "Randomize the module region over a 4 GB range" 1864 depends on RANDOMIZE_BASE 1865 default y 1866 help 1867 Randomizes the location of the module region inside a 4 GB window 1868 covering the core kernel. This way, it is less likely for modules 1869 to leak information about the location of core kernel data structures 1870 but it does imply that function calls between modules and the core 1871 kernel will need to be resolved via veneers in the module PLT. 1872 1873 When this option is not set, the module region will be randomized over 1874 a limited range that contains the [_stext, _etext] interval of the 1875 core kernel, so branch relocations are always in range. 1876 1877config CC_HAVE_STACKPROTECTOR_SYSREG 1878 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1879 1880config STACKPROTECTOR_PER_TASK 1881 def_bool y 1882 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1883 1884endmenu 1885 1886menu "Boot options" 1887 1888config ARM64_ACPI_PARKING_PROTOCOL 1889 bool "Enable support for the ARM64 ACPI parking protocol" 1890 depends on ACPI 1891 help 1892 Enable support for the ARM64 ACPI parking protocol. If disabled 1893 the kernel will not allow booting through the ARM64 ACPI parking 1894 protocol even if the corresponding data is present in the ACPI 1895 MADT table. 1896 1897config CMDLINE 1898 string "Default kernel command string" 1899 default "" 1900 help 1901 Provide a set of default command-line options at build time by 1902 entering them here. As a minimum, you should specify the the 1903 root device (e.g. root=/dev/nfs). 1904 1905config CMDLINE_FORCE 1906 bool "Always use the default kernel command string" 1907 depends on CMDLINE != "" 1908 help 1909 Always use the default kernel command string, even if the boot 1910 loader passes other arguments to the kernel. 1911 This is useful if you cannot or don't want to change the 1912 command-line options your boot loader passes to the kernel. 1913 1914config EFI_STUB 1915 bool 1916 1917config EFI 1918 bool "UEFI runtime support" 1919 depends on OF && !CPU_BIG_ENDIAN 1920 depends on KERNEL_MODE_NEON 1921 select ARCH_SUPPORTS_ACPI 1922 select LIBFDT 1923 select UCS2_STRING 1924 select EFI_PARAMS_FROM_FDT 1925 select EFI_RUNTIME_WRAPPERS 1926 select EFI_STUB 1927 select EFI_GENERIC_STUB 1928 default y 1929 help 1930 This option provides support for runtime services provided 1931 by UEFI firmware (such as non-volatile variables, realtime 1932 clock, and platform reset). A UEFI stub is also provided to 1933 allow the kernel to be booted as an EFI application. This 1934 is only useful on systems that have UEFI firmware. 1935 1936config DMI 1937 bool "Enable support for SMBIOS (DMI) tables" 1938 depends on EFI 1939 default y 1940 help 1941 This enables SMBIOS/DMI feature for systems. 1942 1943 This option is only useful on systems that have UEFI firmware. 1944 However, even with this option, the resultant kernel should 1945 continue to boot on existing non-UEFI platforms. 1946 1947endmenu 1948 1949config SYSVIPC_COMPAT 1950 def_bool y 1951 depends on COMPAT && SYSVIPC 1952 1953config ARCH_ENABLE_HUGEPAGE_MIGRATION 1954 def_bool y 1955 depends on HUGETLB_PAGE && MIGRATION 1956 1957config ARCH_ENABLE_THP_MIGRATION 1958 def_bool y 1959 depends on TRANSPARENT_HUGEPAGE 1960 1961menu "Power management options" 1962 1963source "kernel/power/Kconfig" 1964 1965config ARCH_HIBERNATION_POSSIBLE 1966 def_bool y 1967 depends on CPU_PM 1968 1969config ARCH_HIBERNATION_HEADER 1970 def_bool y 1971 depends on HIBERNATION 1972 1973config ARCH_SUSPEND_POSSIBLE 1974 def_bool y 1975 1976endmenu 1977 1978menu "CPU Power Management" 1979 1980source "drivers/cpuidle/Kconfig" 1981 1982source "drivers/cpufreq/Kconfig" 1983 1984endmenu 1985 1986source "drivers/firmware/Kconfig" 1987 1988source "drivers/acpi/Kconfig" 1989 1990source "arch/arm64/kvm/Kconfig" 1991 1992if CRYPTO 1993source "arch/arm64/crypto/Kconfig" 1994endif 1995