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_CORRECT_STACKTRACE_ON_KRETPROBE 15 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 16 select ARCH_ENABLE_MEMORY_HOTPLUG 17 select ARCH_ENABLE_MEMORY_HOTREMOVE 18 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 19 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 20 select ARCH_HAS_CACHE_LINE_SIZE 21 select ARCH_HAS_DEBUG_VIRTUAL 22 select ARCH_HAS_DEBUG_VM_PGTABLE 23 select ARCH_HAS_DMA_PREP_COHERENT 24 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 25 select ARCH_HAS_FAST_MULTIPLIER 26 select ARCH_HAS_FORTIFY_SOURCE 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_HAS_GIGANTIC_PAGE 29 select ARCH_HAS_KCOV 30 select ARCH_HAS_KEEPINITRD 31 select ARCH_HAS_MEMBARRIER_SYNC_CORE 32 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 33 select ARCH_HAS_PTE_DEVMAP 34 select ARCH_HAS_PTE_SPECIAL 35 select ARCH_HAS_SETUP_DMA_OPS 36 select ARCH_HAS_SET_DIRECT_MAP 37 select ARCH_HAS_SET_MEMORY 38 select ARCH_STACKWALK 39 select ARCH_HAS_STRICT_KERNEL_RWX 40 select ARCH_HAS_STRICT_MODULE_RWX 41 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 42 select ARCH_HAS_SYNC_DMA_FOR_CPU 43 select ARCH_HAS_SYSCALL_WRAPPER 44 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 45 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 46 select ARCH_HAS_ZONE_DMA_SET if EXPERT 47 select ARCH_HAVE_ELF_PROT 48 select ARCH_HAVE_NMI_SAFE_CMPXCHG 49 select ARCH_INLINE_READ_LOCK if !PREEMPTION 50 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 51 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 52 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 53 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 54 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 55 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 56 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 57 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 58 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 59 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 60 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 61 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 62 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 63 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 64 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 65 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 66 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 67 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 68 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 69 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 70 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 71 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 72 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 73 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 74 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 75 select ARCH_KEEP_MEMBLOCK 76 select ARCH_USE_CMPXCHG_LOCKREF 77 select ARCH_USE_GNU_PROPERTY 78 select ARCH_USE_MEMTEST 79 select ARCH_USE_QUEUED_RWLOCKS 80 select ARCH_USE_QUEUED_SPINLOCKS 81 select ARCH_USE_SYM_ANNOTATIONS 82 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 83 select ARCH_SUPPORTS_HUGETLBFS 84 select ARCH_SUPPORTS_MEMORY_FAILURE 85 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 86 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 87 select ARCH_SUPPORTS_LTO_CLANG_THIN 88 select ARCH_SUPPORTS_CFI_CLANG 89 select ARCH_SUPPORTS_ATOMIC_RMW 90 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 91 select ARCH_SUPPORTS_NUMA_BALANCING 92 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 93 select ARCH_WANT_DEFAULT_BPF_JIT 94 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 95 select ARCH_WANT_FRAME_POINTERS 96 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 97 select ARCH_WANT_LD_ORPHAN_WARN 98 select ARCH_WANTS_NO_INSTR 99 select ARCH_HAS_UBSAN_SANITIZE_ALL 100 select ARM_AMBA 101 select ARM_ARCH_TIMER 102 select ARM_GIC 103 select AUDIT_ARCH_COMPAT_GENERIC 104 select ARM_GIC_V2M if PCI 105 select ARM_GIC_V3 106 select ARM_GIC_V3_ITS if PCI 107 select ARM_PSCI_FW 108 select BUILDTIME_TABLE_SORT 109 select CLONE_BACKWARDS 110 select COMMON_CLK 111 select CPU_PM if (SUSPEND || CPU_IDLE) 112 select CRC32 113 select DCACHE_WORD_ACCESS 114 select DMA_DIRECT_REMAP 115 select EDAC_SUPPORT 116 select FRAME_POINTER 117 select GENERIC_ALLOCATOR 118 select GENERIC_ARCH_TOPOLOGY 119 select GENERIC_CLOCKEVENTS_BROADCAST 120 select GENERIC_CPU_AUTOPROBE 121 select GENERIC_CPU_VULNERABILITIES 122 select GENERIC_EARLY_IOREMAP 123 select GENERIC_FIND_FIRST_BIT 124 select GENERIC_IDLE_POLL_SETUP 125 select GENERIC_IRQ_IPI 126 select GENERIC_IRQ_PROBE 127 select GENERIC_IRQ_SHOW 128 select GENERIC_IRQ_SHOW_LEVEL 129 select GENERIC_LIB_DEVMEM_IS_ALLOWED 130 select GENERIC_PCI_IOMAP 131 select GENERIC_PTDUMP 132 select GENERIC_SCHED_CLOCK 133 select GENERIC_SMP_IDLE_THREAD 134 select GENERIC_TIME_VSYSCALL 135 select GENERIC_GETTIMEOFDAY 136 select GENERIC_VDSO_TIME_NS 137 select HARDIRQS_SW_RESEND 138 select HAVE_MOVE_PMD 139 select HAVE_MOVE_PUD 140 select HAVE_PCI 141 select HAVE_ACPI_APEI if (ACPI && EFI) 142 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 143 select HAVE_ARCH_AUDITSYSCALL 144 select HAVE_ARCH_BITREVERSE 145 select HAVE_ARCH_COMPILER_H 146 select HAVE_ARCH_HUGE_VMAP 147 select HAVE_ARCH_JUMP_LABEL 148 select HAVE_ARCH_JUMP_LABEL_RELATIVE 149 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 150 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 151 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 152 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 153 # Some instrumentation may be unsound, hence EXPERT 154 select HAVE_ARCH_KCSAN if EXPERT 155 select HAVE_ARCH_KFENCE 156 select HAVE_ARCH_KGDB 157 select HAVE_ARCH_MMAP_RND_BITS 158 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 159 select HAVE_ARCH_PREL32_RELOCATIONS 160 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 161 select HAVE_ARCH_SECCOMP_FILTER 162 select HAVE_ARCH_STACKLEAK 163 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 164 select HAVE_ARCH_TRACEHOOK 165 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 166 select HAVE_ARCH_VMAP_STACK 167 select HAVE_ARM_SMCCC 168 select HAVE_ASM_MODVERSIONS 169 select HAVE_EBPF_JIT 170 select HAVE_C_RECORDMCOUNT 171 select HAVE_CMPXCHG_DOUBLE 172 select HAVE_CMPXCHG_LOCAL 173 select HAVE_CONTEXT_TRACKING 174 select HAVE_DEBUG_KMEMLEAK 175 select HAVE_DMA_CONTIGUOUS 176 select HAVE_DYNAMIC_FTRACE 177 select HAVE_DYNAMIC_FTRACE_WITH_REGS \ 178 if $(cc-option,-fpatchable-function-entry=2) 179 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 180 if DYNAMIC_FTRACE_WITH_REGS 181 select HAVE_EFFICIENT_UNALIGNED_ACCESS 182 select HAVE_FAST_GUP 183 select HAVE_FTRACE_MCOUNT_RECORD 184 select HAVE_FUNCTION_TRACER 185 select HAVE_FUNCTION_ERROR_INJECTION 186 select HAVE_FUNCTION_GRAPH_TRACER 187 select HAVE_GCC_PLUGINS 188 select HAVE_HW_BREAKPOINT if PERF_EVENTS 189 select HAVE_IRQ_TIME_ACCOUNTING 190 select HAVE_KVM 191 select HAVE_NMI 192 select HAVE_PATA_PLATFORM 193 select HAVE_PERF_EVENTS 194 select HAVE_PERF_REGS 195 select HAVE_PERF_USER_STACK_DUMP 196 select HAVE_REGS_AND_STACK_ACCESS_API 197 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 198 select HAVE_FUNCTION_ARG_ACCESS_API 199 select HAVE_FUTEX_CMPXCHG if FUTEX 200 select MMU_GATHER_RCU_TABLE_FREE 201 select HAVE_RSEQ 202 select HAVE_STACKPROTECTOR 203 select HAVE_SYSCALL_TRACEPOINTS 204 select HAVE_KPROBES 205 select HAVE_KRETPROBES 206 select HAVE_GENERIC_VDSO 207 select IOMMU_DMA if IOMMU_SUPPORT 208 select IRQ_DOMAIN 209 select IRQ_FORCED_THREADING 210 select KASAN_VMALLOC if KASAN_GENERIC 211 select MODULES_USE_ELF_RELA 212 select NEED_DMA_MAP_STATE 213 select NEED_SG_DMA_LENGTH 214 select OF 215 select OF_EARLY_FLATTREE 216 select PCI_DOMAINS_GENERIC if PCI 217 select PCI_ECAM if (ACPI && PCI) 218 select PCI_SYSCALL if PCI 219 select POWER_RESET 220 select POWER_SUPPLY 221 select SPARSE_IRQ 222 select SWIOTLB 223 select SYSCTL_EXCEPTION_TRACE 224 select THREAD_INFO_IN_TASK 225 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 226 select TRACE_IRQFLAGS_SUPPORT 227 help 228 ARM 64-bit (AArch64) Linux support. 229 230config 64BIT 231 def_bool y 232 233config MMU 234 def_bool y 235 236config ARM64_PAGE_SHIFT 237 int 238 default 16 if ARM64_64K_PAGES 239 default 14 if ARM64_16K_PAGES 240 default 12 241 242config ARM64_CONT_PTE_SHIFT 243 int 244 default 5 if ARM64_64K_PAGES 245 default 7 if ARM64_16K_PAGES 246 default 4 247 248config ARM64_CONT_PMD_SHIFT 249 int 250 default 5 if ARM64_64K_PAGES 251 default 5 if ARM64_16K_PAGES 252 default 4 253 254config ARCH_MMAP_RND_BITS_MIN 255 default 14 if ARM64_64K_PAGES 256 default 16 if ARM64_16K_PAGES 257 default 18 258 259# max bits determined by the following formula: 260# VA_BITS - PAGE_SHIFT - 3 261config ARCH_MMAP_RND_BITS_MAX 262 default 19 if ARM64_VA_BITS=36 263 default 24 if ARM64_VA_BITS=39 264 default 27 if ARM64_VA_BITS=42 265 default 30 if ARM64_VA_BITS=47 266 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 267 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 268 default 33 if ARM64_VA_BITS=48 269 default 14 if ARM64_64K_PAGES 270 default 16 if ARM64_16K_PAGES 271 default 18 272 273config ARCH_MMAP_RND_COMPAT_BITS_MIN 274 default 7 if ARM64_64K_PAGES 275 default 9 if ARM64_16K_PAGES 276 default 11 277 278config ARCH_MMAP_RND_COMPAT_BITS_MAX 279 default 16 280 281config NO_IOPORT_MAP 282 def_bool y if !PCI 283 284config STACKTRACE_SUPPORT 285 def_bool y 286 287config ILLEGAL_POINTER_VALUE 288 hex 289 default 0xdead000000000000 290 291config LOCKDEP_SUPPORT 292 def_bool y 293 294config GENERIC_BUG 295 def_bool y 296 depends on BUG 297 298config GENERIC_BUG_RELATIVE_POINTERS 299 def_bool y 300 depends on GENERIC_BUG 301 302config GENERIC_HWEIGHT 303 def_bool y 304 305config GENERIC_CSUM 306 def_bool y 307 308config GENERIC_CALIBRATE_DELAY 309 def_bool y 310 311config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 312 def_bool y 313 314config SMP 315 def_bool y 316 317config KERNEL_MODE_NEON 318 def_bool y 319 320config FIX_EARLYCON_MEM 321 def_bool y 322 323config PGTABLE_LEVELS 324 int 325 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 326 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 327 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 328 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 329 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 330 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 331 332config ARCH_SUPPORTS_UPROBES 333 def_bool y 334 335config ARCH_PROC_KCORE_TEXT 336 def_bool y 337 338config BROKEN_GAS_INST 339 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 340 341config KASAN_SHADOW_OFFSET 342 hex 343 depends on KASAN_GENERIC || KASAN_SW_TAGS 344 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 345 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 346 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 347 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 348 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 349 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 350 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 351 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 352 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 353 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 354 default 0xffffffffffffffff 355 356source "arch/arm64/Kconfig.platforms" 357 358menu "Kernel Features" 359 360menu "ARM errata workarounds via the alternatives framework" 361 362config ARM64_WORKAROUND_CLEAN_CACHE 363 bool 364 365config ARM64_ERRATUM_826319 366 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 367 default y 368 select ARM64_WORKAROUND_CLEAN_CACHE 369 help 370 This option adds an alternative code sequence to work around ARM 371 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 372 AXI master interface and an L2 cache. 373 374 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 375 and is unable to accept a certain write via this interface, it will 376 not progress on read data presented on the read data channel and the 377 system can deadlock. 378 379 The workaround promotes data cache clean instructions to 380 data cache clean-and-invalidate. 381 Please note that this does not necessarily enable the workaround, 382 as it depends on the alternative framework, which will only patch 383 the kernel if an affected CPU is detected. 384 385 If unsure, say Y. 386 387config ARM64_ERRATUM_827319 388 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 389 default y 390 select ARM64_WORKAROUND_CLEAN_CACHE 391 help 392 This option adds an alternative code sequence to work around ARM 393 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 394 master interface and an L2 cache. 395 396 Under certain conditions this erratum can cause a clean line eviction 397 to occur at the same time as another transaction to the same address 398 on the AMBA 5 CHI interface, which can cause data corruption if the 399 interconnect reorders the two transactions. 400 401 The workaround promotes data cache clean instructions to 402 data cache clean-and-invalidate. 403 Please note that this does not necessarily enable the workaround, 404 as it depends on the alternative framework, which will only patch 405 the kernel if an affected CPU is detected. 406 407 If unsure, say Y. 408 409config ARM64_ERRATUM_824069 410 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 411 default y 412 select ARM64_WORKAROUND_CLEAN_CACHE 413 help 414 This option adds an alternative code sequence to work around ARM 415 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 416 to a coherent interconnect. 417 418 If a Cortex-A53 processor is executing a store or prefetch for 419 write instruction at the same time as a processor in another 420 cluster is executing a cache maintenance operation to the same 421 address, then this erratum might cause a clean cache line to be 422 incorrectly marked as dirty. 423 424 The workaround promotes data cache clean instructions to 425 data cache clean-and-invalidate. 426 Please note that this option does not necessarily enable the 427 workaround, as it depends on the alternative framework, which will 428 only patch the kernel if an affected CPU is detected. 429 430 If unsure, say Y. 431 432config ARM64_ERRATUM_819472 433 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 434 default y 435 select ARM64_WORKAROUND_CLEAN_CACHE 436 help 437 This option adds an alternative code sequence to work around ARM 438 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 439 present when it is connected to a coherent interconnect. 440 441 If the processor is executing a load and store exclusive sequence at 442 the same time as a processor in another cluster is executing a cache 443 maintenance operation to the same address, then this erratum might 444 cause data corruption. 445 446 The workaround promotes data cache clean instructions to 447 data cache clean-and-invalidate. 448 Please note that this does not necessarily enable the workaround, 449 as it depends on the alternative framework, which will only patch 450 the kernel if an affected CPU is detected. 451 452 If unsure, say Y. 453 454config ARM64_ERRATUM_832075 455 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 456 default y 457 help 458 This option adds an alternative code sequence to work around ARM 459 erratum 832075 on Cortex-A57 parts up to r1p2. 460 461 Affected Cortex-A57 parts might deadlock when exclusive load/store 462 instructions to Write-Back memory are mixed with Device loads. 463 464 The workaround is to promote device loads to use Load-Acquire 465 semantics. 466 Please note that this does not necessarily enable the workaround, 467 as it depends on the alternative framework, which will only patch 468 the kernel if an affected CPU is detected. 469 470 If unsure, say Y. 471 472config ARM64_ERRATUM_834220 473 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 474 depends on KVM 475 default y 476 help 477 This option adds an alternative code sequence to work around ARM 478 erratum 834220 on Cortex-A57 parts up to r1p2. 479 480 Affected Cortex-A57 parts might report a Stage 2 translation 481 fault as the result of a Stage 1 fault for load crossing a 482 page boundary when there is a permission or device memory 483 alignment fault at Stage 1 and a translation fault at Stage 2. 484 485 The workaround is to verify that the Stage 1 translation 486 doesn't generate a fault before handling the Stage 2 fault. 487 Please note that this does not necessarily enable the workaround, 488 as it depends on the alternative framework, which will only patch 489 the kernel if an affected CPU is detected. 490 491 If unsure, say Y. 492 493config ARM64_ERRATUM_845719 494 bool "Cortex-A53: 845719: a load might read incorrect data" 495 depends on COMPAT 496 default y 497 help 498 This option adds an alternative code sequence to work around ARM 499 erratum 845719 on Cortex-A53 parts up to r0p4. 500 501 When running a compat (AArch32) userspace on an affected Cortex-A53 502 part, a load at EL0 from a virtual address that matches the bottom 32 503 bits of the virtual address used by a recent load at (AArch64) EL1 504 might return incorrect data. 505 506 The workaround is to write the contextidr_el1 register on exception 507 return to a 32-bit task. 508 Please note that this does not necessarily enable the workaround, 509 as it depends on the alternative framework, which will only patch 510 the kernel if an affected CPU is detected. 511 512 If unsure, say Y. 513 514config ARM64_ERRATUM_843419 515 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 516 default y 517 select ARM64_MODULE_PLTS if MODULES 518 help 519 This option links the kernel with '--fix-cortex-a53-843419' and 520 enables PLT support to replace certain ADRP instructions, which can 521 cause subsequent memory accesses to use an incorrect address on 522 Cortex-A53 parts up to r0p4. 523 524 If unsure, say Y. 525 526config ARM64_LD_HAS_FIX_ERRATUM_843419 527 def_bool $(ld-option,--fix-cortex-a53-843419) 528 529config ARM64_ERRATUM_1024718 530 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 531 default y 532 help 533 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 534 535 Affected Cortex-A55 cores (all revisions) could cause incorrect 536 update of the hardware dirty bit when the DBM/AP bits are updated 537 without a break-before-make. The workaround is to disable the usage 538 of hardware DBM locally on the affected cores. CPUs not affected by 539 this erratum will continue to use the feature. 540 541 If unsure, say Y. 542 543config ARM64_ERRATUM_1418040 544 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 545 default y 546 depends on COMPAT 547 help 548 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 549 errata 1188873 and 1418040. 550 551 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 552 cause register corruption when accessing the timer registers 553 from AArch32 userspace. 554 555 If unsure, say Y. 556 557config ARM64_WORKAROUND_SPECULATIVE_AT 558 bool 559 560config ARM64_ERRATUM_1165522 561 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 562 default y 563 select ARM64_WORKAROUND_SPECULATIVE_AT 564 help 565 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 566 567 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 568 corrupted TLBs by speculating an AT instruction during a guest 569 context switch. 570 571 If unsure, say Y. 572 573config ARM64_ERRATUM_1319367 574 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 575 default y 576 select ARM64_WORKAROUND_SPECULATIVE_AT 577 help 578 This option adds work arounds for ARM Cortex-A57 erratum 1319537 579 and A72 erratum 1319367 580 581 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 582 speculating an AT instruction during a guest context switch. 583 584 If unsure, say Y. 585 586config ARM64_ERRATUM_1530923 587 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 588 default y 589 select ARM64_WORKAROUND_SPECULATIVE_AT 590 help 591 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 592 593 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 594 corrupted TLBs by speculating an AT instruction during a guest 595 context switch. 596 597 If unsure, say Y. 598 599config ARM64_WORKAROUND_REPEAT_TLBI 600 bool 601 602config ARM64_ERRATUM_1286807 603 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 604 default y 605 select ARM64_WORKAROUND_REPEAT_TLBI 606 help 607 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 608 609 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 610 address for a cacheable mapping of a location is being 611 accessed by a core while another core is remapping the virtual 612 address to a new physical page using the recommended 613 break-before-make sequence, then under very rare circumstances 614 TLBI+DSB completes before a read using the translation being 615 invalidated has been observed by other observers. The 616 workaround repeats the TLBI+DSB operation. 617 618config ARM64_ERRATUM_1463225 619 bool "Cortex-A76: Software Step might prevent interrupt recognition" 620 default y 621 help 622 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 623 624 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 625 of a system call instruction (SVC) can prevent recognition of 626 subsequent interrupts when software stepping is disabled in the 627 exception handler of the system call and either kernel debugging 628 is enabled or VHE is in use. 629 630 Work around the erratum by triggering a dummy step exception 631 when handling a system call from a task that is being stepped 632 in a VHE configuration of the kernel. 633 634 If unsure, say Y. 635 636config ARM64_ERRATUM_1542419 637 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 638 default y 639 help 640 This option adds a workaround for ARM Neoverse-N1 erratum 641 1542419. 642 643 Affected Neoverse-N1 cores could execute a stale instruction when 644 modified by another CPU. The workaround depends on a firmware 645 counterpart. 646 647 Workaround the issue by hiding the DIC feature from EL0. This 648 forces user-space to perform cache maintenance. 649 650 If unsure, say Y. 651 652config ARM64_ERRATUM_1508412 653 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 654 default y 655 help 656 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 657 658 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 659 of a store-exclusive or read of PAR_EL1 and a load with device or 660 non-cacheable memory attributes. The workaround depends on a firmware 661 counterpart. 662 663 KVM guests must also have the workaround implemented or they can 664 deadlock the system. 665 666 Work around the issue by inserting DMB SY barriers around PAR_EL1 667 register reads and warning KVM users. The DMB barrier is sufficient 668 to prevent a speculative PAR_EL1 read. 669 670 If unsure, say Y. 671 672config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 673 bool 674 675config ARM64_ERRATUM_2119858 676 bool "Cortex-A710: 2119858: workaround TRBE overwriting trace data in FILL mode" 677 default y 678 depends on CORESIGHT_TRBE 679 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 680 help 681 This option adds the workaround for ARM Cortex-A710 erratum 2119858. 682 683 Affected Cortex-A710 cores could overwrite up to 3 cache lines of trace 684 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 685 the event of a WRAP event. 686 687 Work around the issue by always making sure we move the TRBPTR_EL1 by 688 256 bytes before enabling the buffer and filling the first 256 bytes of 689 the buffer with ETM ignore packets upon disabling. 690 691 If unsure, say Y. 692 693config ARM64_ERRATUM_2139208 694 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 695 default y 696 depends on CORESIGHT_TRBE 697 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 698 help 699 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 700 701 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 702 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 703 the event of a WRAP event. 704 705 Work around the issue by always making sure we move the TRBPTR_EL1 by 706 256 bytes before enabling the buffer and filling the first 256 bytes of 707 the buffer with ETM ignore packets upon disabling. 708 709 If unsure, say Y. 710 711config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 712 bool 713 714config ARM64_ERRATUM_2054223 715 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 716 default y 717 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 718 help 719 Enable workaround for ARM Cortex-A710 erratum 2054223 720 721 Affected cores may fail to flush the trace data on a TSB instruction, when 722 the PE is in trace prohibited state. This will cause losing a few bytes 723 of the trace cached. 724 725 Workaround is to issue two TSB consecutively on affected cores. 726 727 If unsure, say Y. 728 729config ARM64_ERRATUM_2067961 730 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 731 default y 732 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 733 help 734 Enable workaround for ARM Neoverse-N2 erratum 2067961 735 736 Affected cores may fail to flush the trace data on a TSB instruction, when 737 the PE is in trace prohibited state. This will cause losing a few bytes 738 of the trace cached. 739 740 Workaround is to issue two TSB consecutively on affected cores. 741 742 If unsure, say Y. 743 744config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 745 bool 746 747config ARM64_ERRATUM_2253138 748 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 749 depends on CORESIGHT_TRBE 750 default y 751 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 752 help 753 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 754 755 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 756 for TRBE. Under some conditions, the TRBE might generate a write to the next 757 virtually addressed page following the last page of the TRBE address space 758 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 759 760 Work around this in the driver by always making sure that there is a 761 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 762 763 If unsure, say Y. 764 765config ARM64_ERRATUM_2224489 766 bool "Cortex-A710: 2224489: workaround TRBE writing to address out-of-range" 767 depends on CORESIGHT_TRBE 768 default y 769 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 770 help 771 This option adds the workaround for ARM Cortex-A710 erratum 2224489. 772 773 Affected Cortex-A710 cores might write to an out-of-range address, not reserved 774 for TRBE. Under some conditions, the TRBE might generate a write to the next 775 virtually addressed page following the last page of the TRBE address space 776 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 777 778 Work around this in the driver by always making sure that there is a 779 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 780 781 If unsure, say Y. 782 783config CAVIUM_ERRATUM_22375 784 bool "Cavium erratum 22375, 24313" 785 default y 786 help 787 Enable workaround for errata 22375 and 24313. 788 789 This implements two gicv3-its errata workarounds for ThunderX. Both 790 with a small impact affecting only ITS table allocation. 791 792 erratum 22375: only alloc 8MB table size 793 erratum 24313: ignore memory access type 794 795 The fixes are in ITS initialization and basically ignore memory access 796 type and table size provided by the TYPER and BASER registers. 797 798 If unsure, say Y. 799 800config CAVIUM_ERRATUM_23144 801 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 802 depends on NUMA 803 default y 804 help 805 ITS SYNC command hang for cross node io and collections/cpu mapping. 806 807 If unsure, say Y. 808 809config CAVIUM_ERRATUM_23154 810 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 811 default y 812 help 813 The gicv3 of ThunderX requires a modified version for 814 reading the IAR status to ensure data synchronization 815 (access to icc_iar1_el1 is not sync'ed before and after). 816 817 If unsure, say Y. 818 819config CAVIUM_ERRATUM_27456 820 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 821 default y 822 help 823 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 824 instructions may cause the icache to become corrupted if it 825 contains data for a non-current ASID. The fix is to 826 invalidate the icache when changing the mm context. 827 828 If unsure, say Y. 829 830config CAVIUM_ERRATUM_30115 831 bool "Cavium erratum 30115: Guest may disable interrupts in host" 832 default y 833 help 834 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 835 1.2, and T83 Pass 1.0, KVM guest execution may disable 836 interrupts in host. Trapping both GICv3 group-0 and group-1 837 accesses sidesteps the issue. 838 839 If unsure, say Y. 840 841config CAVIUM_TX2_ERRATUM_219 842 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 843 default y 844 help 845 On Cavium ThunderX2, a load, store or prefetch instruction between a 846 TTBR update and the corresponding context synchronizing operation can 847 cause a spurious Data Abort to be delivered to any hardware thread in 848 the CPU core. 849 850 Work around the issue by avoiding the problematic code sequence and 851 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 852 trap handler performs the corresponding register access, skips the 853 instruction and ensures context synchronization by virtue of the 854 exception return. 855 856 If unsure, say Y. 857 858config FUJITSU_ERRATUM_010001 859 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 860 default y 861 help 862 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 863 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 864 accesses may cause undefined fault (Data abort, DFSC=0b111111). 865 This fault occurs under a specific hardware condition when a 866 load/store instruction performs an address translation using: 867 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 868 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 869 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 870 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 871 872 The workaround is to ensure these bits are clear in TCR_ELx. 873 The workaround only affects the Fujitsu-A64FX. 874 875 If unsure, say Y. 876 877config HISILICON_ERRATUM_161600802 878 bool "Hip07 161600802: Erroneous redistributor VLPI base" 879 default y 880 help 881 The HiSilicon Hip07 SoC uses the wrong redistributor base 882 when issued ITS commands such as VMOVP and VMAPP, and requires 883 a 128kB offset to be applied to the target address in this commands. 884 885 If unsure, say Y. 886 887config QCOM_FALKOR_ERRATUM_1003 888 bool "Falkor E1003: Incorrect translation due to ASID change" 889 default y 890 help 891 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 892 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 893 in TTBR1_EL1, this situation only occurs in the entry trampoline and 894 then only for entries in the walk cache, since the leaf translation 895 is unchanged. Work around the erratum by invalidating the walk cache 896 entries for the trampoline before entering the kernel proper. 897 898config QCOM_FALKOR_ERRATUM_1009 899 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 900 default y 901 select ARM64_WORKAROUND_REPEAT_TLBI 902 help 903 On Falkor v1, the CPU may prematurely complete a DSB following a 904 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 905 one more time to fix the issue. 906 907 If unsure, say Y. 908 909config QCOM_QDF2400_ERRATUM_0065 910 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 911 default y 912 help 913 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 914 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 915 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 916 917 If unsure, say Y. 918 919config QCOM_FALKOR_ERRATUM_E1041 920 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 921 default y 922 help 923 Falkor CPU may speculatively fetch instructions from an improper 924 memory location when MMU translation is changed from SCTLR_ELn[M]=1 925 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 926 927 If unsure, say Y. 928 929config NVIDIA_CARMEL_CNP_ERRATUM 930 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 931 default y 932 help 933 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 934 invalidate shared TLB entries installed by a different core, as it would 935 on standard ARM cores. 936 937 If unsure, say Y. 938 939config SOCIONEXT_SYNQUACER_PREITS 940 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 941 default y 942 help 943 Socionext Synquacer SoCs implement a separate h/w block to generate 944 MSI doorbell writes with non-zero values for the device ID. 945 946 If unsure, say Y. 947 948endmenu 949 950 951choice 952 prompt "Page size" 953 default ARM64_4K_PAGES 954 help 955 Page size (translation granule) configuration. 956 957config ARM64_4K_PAGES 958 bool "4KB" 959 help 960 This feature enables 4KB pages support. 961 962config ARM64_16K_PAGES 963 bool "16KB" 964 help 965 The system will use 16KB pages support. AArch32 emulation 966 requires applications compiled with 16K (or a multiple of 16K) 967 aligned segments. 968 969config ARM64_64K_PAGES 970 bool "64KB" 971 help 972 This feature enables 64KB pages support (4KB by default) 973 allowing only two levels of page tables and faster TLB 974 look-up. AArch32 emulation requires applications compiled 975 with 64K aligned segments. 976 977endchoice 978 979choice 980 prompt "Virtual address space size" 981 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 982 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 983 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 984 help 985 Allows choosing one of multiple possible virtual address 986 space sizes. The level of translation table is determined by 987 a combination of page size and virtual address space size. 988 989config ARM64_VA_BITS_36 990 bool "36-bit" if EXPERT 991 depends on ARM64_16K_PAGES 992 993config ARM64_VA_BITS_39 994 bool "39-bit" 995 depends on ARM64_4K_PAGES 996 997config ARM64_VA_BITS_42 998 bool "42-bit" 999 depends on ARM64_64K_PAGES 1000 1001config ARM64_VA_BITS_47 1002 bool "47-bit" 1003 depends on ARM64_16K_PAGES 1004 1005config ARM64_VA_BITS_48 1006 bool "48-bit" 1007 1008config ARM64_VA_BITS_52 1009 bool "52-bit" 1010 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1011 help 1012 Enable 52-bit virtual addressing for userspace when explicitly 1013 requested via a hint to mmap(). The kernel will also use 52-bit 1014 virtual addresses for its own mappings (provided HW support for 1015 this feature is available, otherwise it reverts to 48-bit). 1016 1017 NOTE: Enabling 52-bit virtual addressing in conjunction with 1018 ARMv8.3 Pointer Authentication will result in the PAC being 1019 reduced from 7 bits to 3 bits, which may have a significant 1020 impact on its susceptibility to brute-force attacks. 1021 1022 If unsure, select 48-bit virtual addressing instead. 1023 1024endchoice 1025 1026config ARM64_FORCE_52BIT 1027 bool "Force 52-bit virtual addresses for userspace" 1028 depends on ARM64_VA_BITS_52 && EXPERT 1029 help 1030 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1031 to maintain compatibility with older software by providing 48-bit VAs 1032 unless a hint is supplied to mmap. 1033 1034 This configuration option disables the 48-bit compatibility logic, and 1035 forces all userspace addresses to be 52-bit on HW that supports it. One 1036 should only enable this configuration option for stress testing userspace 1037 memory management code. If unsure say N here. 1038 1039config ARM64_VA_BITS 1040 int 1041 default 36 if ARM64_VA_BITS_36 1042 default 39 if ARM64_VA_BITS_39 1043 default 42 if ARM64_VA_BITS_42 1044 default 47 if ARM64_VA_BITS_47 1045 default 48 if ARM64_VA_BITS_48 1046 default 52 if ARM64_VA_BITS_52 1047 1048choice 1049 prompt "Physical address space size" 1050 default ARM64_PA_BITS_48 1051 help 1052 Choose the maximum physical address range that the kernel will 1053 support. 1054 1055config ARM64_PA_BITS_48 1056 bool "48-bit" 1057 1058config ARM64_PA_BITS_52 1059 bool "52-bit (ARMv8.2)" 1060 depends on ARM64_64K_PAGES 1061 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1062 help 1063 Enable support for a 52-bit physical address space, introduced as 1064 part of the ARMv8.2-LPA extension. 1065 1066 With this enabled, the kernel will also continue to work on CPUs that 1067 do not support ARMv8.2-LPA, but with some added memory overhead (and 1068 minor performance overhead). 1069 1070endchoice 1071 1072config ARM64_PA_BITS 1073 int 1074 default 48 if ARM64_PA_BITS_48 1075 default 52 if ARM64_PA_BITS_52 1076 1077choice 1078 prompt "Endianness" 1079 default CPU_LITTLE_ENDIAN 1080 help 1081 Select the endianness of data accesses performed by the CPU. Userspace 1082 applications will need to be compiled and linked for the endianness 1083 that is selected here. 1084 1085config CPU_BIG_ENDIAN 1086 bool "Build big-endian kernel" 1087 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1088 help 1089 Say Y if you plan on running a kernel with a big-endian userspace. 1090 1091config CPU_LITTLE_ENDIAN 1092 bool "Build little-endian kernel" 1093 help 1094 Say Y if you plan on running a kernel with a little-endian userspace. 1095 This is usually the case for distributions targeting arm64. 1096 1097endchoice 1098 1099config SCHED_MC 1100 bool "Multi-core scheduler support" 1101 help 1102 Multi-core scheduler support improves the CPU scheduler's decision 1103 making when dealing with multi-core CPU chips at a cost of slightly 1104 increased overhead in some places. If unsure say N here. 1105 1106config SCHED_CLUSTER 1107 bool "Cluster scheduler support" 1108 help 1109 Cluster scheduler support improves the CPU scheduler's decision 1110 making when dealing with machines that have clusters of CPUs. 1111 Cluster usually means a couple of CPUs which are placed closely 1112 by sharing mid-level caches, last-level cache tags or internal 1113 busses. 1114 1115config SCHED_SMT 1116 bool "SMT scheduler support" 1117 help 1118 Improves the CPU scheduler's decision making when dealing with 1119 MultiThreading at a cost of slightly increased overhead in some 1120 places. If unsure say N here. 1121 1122config NR_CPUS 1123 int "Maximum number of CPUs (2-4096)" 1124 range 2 4096 1125 default "256" 1126 1127config HOTPLUG_CPU 1128 bool "Support for hot-pluggable CPUs" 1129 select GENERIC_IRQ_MIGRATION 1130 help 1131 Say Y here to experiment with turning CPUs off and on. CPUs 1132 can be controlled through /sys/devices/system/cpu. 1133 1134# Common NUMA Features 1135config NUMA 1136 bool "NUMA Memory Allocation and Scheduler Support" 1137 select GENERIC_ARCH_NUMA 1138 select ACPI_NUMA if ACPI 1139 select OF_NUMA 1140 help 1141 Enable NUMA (Non-Uniform Memory Access) support. 1142 1143 The kernel will try to allocate memory used by a CPU on the 1144 local memory of the CPU and add some more 1145 NUMA awareness to the kernel. 1146 1147config NODES_SHIFT 1148 int "Maximum NUMA Nodes (as a power of 2)" 1149 range 1 10 1150 default "4" 1151 depends on NUMA 1152 help 1153 Specify the maximum number of NUMA Nodes available on the target 1154 system. Increases memory reserved to accommodate various tables. 1155 1156config USE_PERCPU_NUMA_NODE_ID 1157 def_bool y 1158 depends on NUMA 1159 1160config HAVE_SETUP_PER_CPU_AREA 1161 def_bool y 1162 depends on NUMA 1163 1164config NEED_PER_CPU_EMBED_FIRST_CHUNK 1165 def_bool y 1166 depends on NUMA 1167 1168config NEED_PER_CPU_PAGE_FIRST_CHUNK 1169 def_bool y 1170 depends on NUMA 1171 1172source "kernel/Kconfig.hz" 1173 1174config ARCH_SPARSEMEM_ENABLE 1175 def_bool y 1176 select SPARSEMEM_VMEMMAP_ENABLE 1177 select SPARSEMEM_VMEMMAP 1178 1179config HW_PERF_EVENTS 1180 def_bool y 1181 depends on ARM_PMU 1182 1183config ARCH_HAS_FILTER_PGPROT 1184 def_bool y 1185 1186# Supported by clang >= 7.0 1187config CC_HAVE_SHADOW_CALL_STACK 1188 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1189 1190config PARAVIRT 1191 bool "Enable paravirtualization code" 1192 help 1193 This changes the kernel so it can modify itself when it is run 1194 under a hypervisor, potentially improving performance significantly 1195 over full virtualization. 1196 1197config PARAVIRT_TIME_ACCOUNTING 1198 bool "Paravirtual steal time accounting" 1199 select PARAVIRT 1200 help 1201 Select this option to enable fine granularity task steal time 1202 accounting. Time spent executing other tasks in parallel with 1203 the current vCPU is discounted from the vCPU power. To account for 1204 that, there can be a small performance impact. 1205 1206 If in doubt, say N here. 1207 1208config KEXEC 1209 depends on PM_SLEEP_SMP 1210 select KEXEC_CORE 1211 bool "kexec system call" 1212 help 1213 kexec is a system call that implements the ability to shutdown your 1214 current kernel, and to start another kernel. It is like a reboot 1215 but it is independent of the system firmware. And like a reboot 1216 you can start any kernel with it, not just Linux. 1217 1218config KEXEC_FILE 1219 bool "kexec file based system call" 1220 select KEXEC_CORE 1221 select HAVE_IMA_KEXEC if IMA 1222 help 1223 This is new version of kexec system call. This system call is 1224 file based and takes file descriptors as system call argument 1225 for kernel and initramfs as opposed to list of segments as 1226 accepted by previous system call. 1227 1228config KEXEC_SIG 1229 bool "Verify kernel signature during kexec_file_load() syscall" 1230 depends on KEXEC_FILE 1231 help 1232 Select this option to verify a signature with loaded kernel 1233 image. If configured, any attempt of loading a image without 1234 valid signature will fail. 1235 1236 In addition to that option, you need to enable signature 1237 verification for the corresponding kernel image type being 1238 loaded in order for this to work. 1239 1240config KEXEC_IMAGE_VERIFY_SIG 1241 bool "Enable Image signature verification support" 1242 default y 1243 depends on KEXEC_SIG 1244 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1245 help 1246 Enable Image signature verification support. 1247 1248comment "Support for PE file signature verification disabled" 1249 depends on KEXEC_SIG 1250 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1251 1252config CRASH_DUMP 1253 bool "Build kdump crash kernel" 1254 help 1255 Generate crash dump after being started by kexec. This should 1256 be normally only set in special crash dump kernels which are 1257 loaded in the main kernel with kexec-tools into a specially 1258 reserved region and then later executed after a crash by 1259 kdump/kexec. 1260 1261 For more details see Documentation/admin-guide/kdump/kdump.rst 1262 1263config TRANS_TABLE 1264 def_bool y 1265 depends on HIBERNATION || KEXEC_CORE 1266 1267config XEN_DOM0 1268 def_bool y 1269 depends on XEN 1270 1271config XEN 1272 bool "Xen guest support on ARM64" 1273 depends on ARM64 && OF 1274 select SWIOTLB_XEN 1275 select PARAVIRT 1276 help 1277 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1278 1279config FORCE_MAX_ZONEORDER 1280 int 1281 default "14" if ARM64_64K_PAGES 1282 default "12" if ARM64_16K_PAGES 1283 default "11" 1284 help 1285 The kernel memory allocator divides physically contiguous memory 1286 blocks into "zones", where each zone is a power of two number of 1287 pages. This option selects the largest power of two that the kernel 1288 keeps in the memory allocator. If you need to allocate very large 1289 blocks of physically contiguous memory, then you may need to 1290 increase this value. 1291 1292 This config option is actually maximum order plus one. For example, 1293 a value of 11 means that the largest free memory block is 2^10 pages. 1294 1295 We make sure that we can allocate upto a HugePage size for each configuration. 1296 Hence we have : 1297 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1298 1299 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1300 4M allocations matching the default size used by generic code. 1301 1302config UNMAP_KERNEL_AT_EL0 1303 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1304 default y 1305 help 1306 Speculation attacks against some high-performance processors can 1307 be used to bypass MMU permission checks and leak kernel data to 1308 userspace. This can be defended against by unmapping the kernel 1309 when running in userspace, mapping it back in on exception entry 1310 via a trampoline page in the vector table. 1311 1312 If unsure, say Y. 1313 1314config RODATA_FULL_DEFAULT_ENABLED 1315 bool "Apply r/o permissions of VM areas also to their linear aliases" 1316 default y 1317 help 1318 Apply read-only attributes of VM areas to the linear alias of 1319 the backing pages as well. This prevents code or read-only data 1320 from being modified (inadvertently or intentionally) via another 1321 mapping of the same memory page. This additional enhancement can 1322 be turned off at runtime by passing rodata=[off|on] (and turned on 1323 with rodata=full if this option is set to 'n') 1324 1325 This requires the linear region to be mapped down to pages, 1326 which may adversely affect performance in some cases. 1327 1328config ARM64_SW_TTBR0_PAN 1329 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1330 help 1331 Enabling this option prevents the kernel from accessing 1332 user-space memory directly by pointing TTBR0_EL1 to a reserved 1333 zeroed area and reserved ASID. The user access routines 1334 restore the valid TTBR0_EL1 temporarily. 1335 1336config ARM64_TAGGED_ADDR_ABI 1337 bool "Enable the tagged user addresses syscall ABI" 1338 default y 1339 help 1340 When this option is enabled, user applications can opt in to a 1341 relaxed ABI via prctl() allowing tagged addresses to be passed 1342 to system calls as pointer arguments. For details, see 1343 Documentation/arm64/tagged-address-abi.rst. 1344 1345menuconfig COMPAT 1346 bool "Kernel support for 32-bit EL0" 1347 depends on ARM64_4K_PAGES || EXPERT 1348 select HAVE_UID16 1349 select OLD_SIGSUSPEND3 1350 select COMPAT_OLD_SIGACTION 1351 help 1352 This option enables support for a 32-bit EL0 running under a 64-bit 1353 kernel at EL1. AArch32-specific components such as system calls, 1354 the user helper functions, VFP support and the ptrace interface are 1355 handled appropriately by the kernel. 1356 1357 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1358 that you will only be able to execute AArch32 binaries that were compiled 1359 with page size aligned segments. 1360 1361 If you want to execute 32-bit userspace applications, say Y. 1362 1363if COMPAT 1364 1365config KUSER_HELPERS 1366 bool "Enable kuser helpers page for 32-bit applications" 1367 default y 1368 help 1369 Warning: disabling this option may break 32-bit user programs. 1370 1371 Provide kuser helpers to compat tasks. The kernel provides 1372 helper code to userspace in read only form at a fixed location 1373 to allow userspace to be independent of the CPU type fitted to 1374 the system. This permits binaries to be run on ARMv4 through 1375 to ARMv8 without modification. 1376 1377 See Documentation/arm/kernel_user_helpers.rst for details. 1378 1379 However, the fixed address nature of these helpers can be used 1380 by ROP (return orientated programming) authors when creating 1381 exploits. 1382 1383 If all of the binaries and libraries which run on your platform 1384 are built specifically for your platform, and make no use of 1385 these helpers, then you can turn this option off to hinder 1386 such exploits. However, in that case, if a binary or library 1387 relying on those helpers is run, it will not function correctly. 1388 1389 Say N here only if you are absolutely certain that you do not 1390 need these helpers; otherwise, the safe option is to say Y. 1391 1392config COMPAT_VDSO 1393 bool "Enable vDSO for 32-bit applications" 1394 depends on !CPU_BIG_ENDIAN 1395 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1396 select GENERIC_COMPAT_VDSO 1397 default y 1398 help 1399 Place in the process address space of 32-bit applications an 1400 ELF shared object providing fast implementations of gettimeofday 1401 and clock_gettime. 1402 1403 You must have a 32-bit build of glibc 2.22 or later for programs 1404 to seamlessly take advantage of this. 1405 1406config THUMB2_COMPAT_VDSO 1407 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1408 depends on COMPAT_VDSO 1409 default y 1410 help 1411 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1412 otherwise with '-marm'. 1413 1414menuconfig ARMV8_DEPRECATED 1415 bool "Emulate deprecated/obsolete ARMv8 instructions" 1416 depends on SYSCTL 1417 help 1418 Legacy software support may require certain instructions 1419 that have been deprecated or obsoleted in the architecture. 1420 1421 Enable this config to enable selective emulation of these 1422 features. 1423 1424 If unsure, say Y 1425 1426if ARMV8_DEPRECATED 1427 1428config SWP_EMULATION 1429 bool "Emulate SWP/SWPB instructions" 1430 help 1431 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1432 they are always undefined. Say Y here to enable software 1433 emulation of these instructions for userspace using LDXR/STXR. 1434 This feature can be controlled at runtime with the abi.swp 1435 sysctl which is disabled by default. 1436 1437 In some older versions of glibc [<=2.8] SWP is used during futex 1438 trylock() operations with the assumption that the code will not 1439 be preempted. This invalid assumption may be more likely to fail 1440 with SWP emulation enabled, leading to deadlock of the user 1441 application. 1442 1443 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1444 on an external transaction monitoring block called a global 1445 monitor to maintain update atomicity. If your system does not 1446 implement a global monitor, this option can cause programs that 1447 perform SWP operations to uncached memory to deadlock. 1448 1449 If unsure, say Y 1450 1451config CP15_BARRIER_EMULATION 1452 bool "Emulate CP15 Barrier instructions" 1453 help 1454 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1455 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1456 strongly recommended to use the ISB, DSB, and DMB 1457 instructions instead. 1458 1459 Say Y here to enable software emulation of these 1460 instructions for AArch32 userspace code. When this option is 1461 enabled, CP15 barrier usage is traced which can help 1462 identify software that needs updating. This feature can be 1463 controlled at runtime with the abi.cp15_barrier sysctl. 1464 1465 If unsure, say Y 1466 1467config SETEND_EMULATION 1468 bool "Emulate SETEND instruction" 1469 help 1470 The SETEND instruction alters the data-endianness of the 1471 AArch32 EL0, and is deprecated in ARMv8. 1472 1473 Say Y here to enable software emulation of the instruction 1474 for AArch32 userspace code. This feature can be controlled 1475 at runtime with the abi.setend sysctl. 1476 1477 Note: All the cpus on the system must have mixed endian support at EL0 1478 for this feature to be enabled. If a new CPU - which doesn't support mixed 1479 endian - is hotplugged in after this feature has been enabled, there could 1480 be unexpected results in the applications. 1481 1482 If unsure, say Y 1483endif 1484 1485endif 1486 1487menu "ARMv8.1 architectural features" 1488 1489config ARM64_HW_AFDBM 1490 bool "Support for hardware updates of the Access and Dirty page flags" 1491 default y 1492 help 1493 The ARMv8.1 architecture extensions introduce support for 1494 hardware updates of the access and dirty information in page 1495 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1496 capable processors, accesses to pages with PTE_AF cleared will 1497 set this bit instead of raising an access flag fault. 1498 Similarly, writes to read-only pages with the DBM bit set will 1499 clear the read-only bit (AP[2]) instead of raising a 1500 permission fault. 1501 1502 Kernels built with this configuration option enabled continue 1503 to work on pre-ARMv8.1 hardware and the performance impact is 1504 minimal. If unsure, say Y. 1505 1506config ARM64_PAN 1507 bool "Enable support for Privileged Access Never (PAN)" 1508 default y 1509 help 1510 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1511 prevents the kernel or hypervisor from accessing user-space (EL0) 1512 memory directly. 1513 1514 Choosing this option will cause any unprotected (not using 1515 copy_to_user et al) memory access to fail with a permission fault. 1516 1517 The feature is detected at runtime, and will remain as a 'nop' 1518 instruction if the cpu does not implement the feature. 1519 1520config AS_HAS_LDAPR 1521 def_bool $(as-instr,.arch_extension rcpc) 1522 1523config AS_HAS_LSE_ATOMICS 1524 def_bool $(as-instr,.arch_extension lse) 1525 1526config ARM64_LSE_ATOMICS 1527 bool 1528 default ARM64_USE_LSE_ATOMICS 1529 depends on AS_HAS_LSE_ATOMICS 1530 1531config ARM64_USE_LSE_ATOMICS 1532 bool "Atomic instructions" 1533 depends on JUMP_LABEL 1534 default y 1535 help 1536 As part of the Large System Extensions, ARMv8.1 introduces new 1537 atomic instructions that are designed specifically to scale in 1538 very large systems. 1539 1540 Say Y here to make use of these instructions for the in-kernel 1541 atomic routines. This incurs a small overhead on CPUs that do 1542 not support these instructions and requires the kernel to be 1543 built with binutils >= 2.25 in order for the new instructions 1544 to be used. 1545 1546endmenu 1547 1548menu "ARMv8.2 architectural features" 1549 1550config AS_HAS_ARMV8_2 1551 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1552 1553config AS_HAS_SHA3 1554 def_bool $(as-instr,.arch armv8.2-a+sha3) 1555 1556config ARM64_PMEM 1557 bool "Enable support for persistent memory" 1558 select ARCH_HAS_PMEM_API 1559 select ARCH_HAS_UACCESS_FLUSHCACHE 1560 help 1561 Say Y to enable support for the persistent memory API based on the 1562 ARMv8.2 DCPoP feature. 1563 1564 The feature is detected at runtime, and the kernel will use DC CVAC 1565 operations if DC CVAP is not supported (following the behaviour of 1566 DC CVAP itself if the system does not define a point of persistence). 1567 1568config ARM64_RAS_EXTN 1569 bool "Enable support for RAS CPU Extensions" 1570 default y 1571 help 1572 CPUs that support the Reliability, Availability and Serviceability 1573 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1574 errors, classify them and report them to software. 1575 1576 On CPUs with these extensions system software can use additional 1577 barriers to determine if faults are pending and read the 1578 classification from a new set of registers. 1579 1580 Selecting this feature will allow the kernel to use these barriers 1581 and access the new registers if the system supports the extension. 1582 Platform RAS features may additionally depend on firmware support. 1583 1584config ARM64_CNP 1585 bool "Enable support for Common Not Private (CNP) translations" 1586 default y 1587 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1588 help 1589 Common Not Private (CNP) allows translation table entries to 1590 be shared between different PEs in the same inner shareable 1591 domain, so the hardware can use this fact to optimise the 1592 caching of such entries in the TLB. 1593 1594 Selecting this option allows the CNP feature to be detected 1595 at runtime, and does not affect PEs that do not implement 1596 this feature. 1597 1598endmenu 1599 1600menu "ARMv8.3 architectural features" 1601 1602config ARM64_PTR_AUTH 1603 bool "Enable support for pointer authentication" 1604 default y 1605 help 1606 Pointer authentication (part of the ARMv8.3 Extensions) provides 1607 instructions for signing and authenticating pointers against secret 1608 keys, which can be used to mitigate Return Oriented Programming (ROP) 1609 and other attacks. 1610 1611 This option enables these instructions at EL0 (i.e. for userspace). 1612 Choosing this option will cause the kernel to initialise secret keys 1613 for each process at exec() time, with these keys being 1614 context-switched along with the process. 1615 1616 The feature is detected at runtime. If the feature is not present in 1617 hardware it will not be advertised to userspace/KVM guest nor will it 1618 be enabled. 1619 1620 If the feature is present on the boot CPU but not on a late CPU, then 1621 the late CPU will be parked. Also, if the boot CPU does not have 1622 address auth and the late CPU has then the late CPU will still boot 1623 but with the feature disabled. On such a system, this option should 1624 not be selected. 1625 1626config ARM64_PTR_AUTH_KERNEL 1627 bool "Use pointer authentication for kernel" 1628 default y 1629 depends on ARM64_PTR_AUTH 1630 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1631 # Modern compilers insert a .note.gnu.property section note for PAC 1632 # which is only understood by binutils starting with version 2.33.1. 1633 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1634 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1635 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1636 help 1637 If the compiler supports the -mbranch-protection or 1638 -msign-return-address flag (e.g. GCC 7 or later), then this option 1639 will cause the kernel itself to be compiled with return address 1640 protection. In this case, and if the target hardware is known to 1641 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1642 disabled with minimal loss of protection. 1643 1644 This feature works with FUNCTION_GRAPH_TRACER option only if 1645 DYNAMIC_FTRACE_WITH_REGS is enabled. 1646 1647config CC_HAS_BRANCH_PROT_PAC_RET 1648 # GCC 9 or later, clang 8 or later 1649 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1650 1651config CC_HAS_SIGN_RETURN_ADDRESS 1652 # GCC 7, 8 1653 def_bool $(cc-option,-msign-return-address=all) 1654 1655config AS_HAS_PAC 1656 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1657 1658config AS_HAS_CFI_NEGATE_RA_STATE 1659 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1660 1661endmenu 1662 1663menu "ARMv8.4 architectural features" 1664 1665config ARM64_AMU_EXTN 1666 bool "Enable support for the Activity Monitors Unit CPU extension" 1667 default y 1668 help 1669 The activity monitors extension is an optional extension introduced 1670 by the ARMv8.4 CPU architecture. This enables support for version 1 1671 of the activity monitors architecture, AMUv1. 1672 1673 To enable the use of this extension on CPUs that implement it, say Y. 1674 1675 Note that for architectural reasons, firmware _must_ implement AMU 1676 support when running on CPUs that present the activity monitors 1677 extension. The required support is present in: 1678 * Version 1.5 and later of the ARM Trusted Firmware 1679 1680 For kernels that have this configuration enabled but boot with broken 1681 firmware, you may need to say N here until the firmware is fixed. 1682 Otherwise you may experience firmware panics or lockups when 1683 accessing the counter registers. Even if you are not observing these 1684 symptoms, the values returned by the register reads might not 1685 correctly reflect reality. Most commonly, the value read will be 0, 1686 indicating that the counter is not enabled. 1687 1688config AS_HAS_ARMV8_4 1689 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1690 1691config ARM64_TLB_RANGE 1692 bool "Enable support for tlbi range feature" 1693 default y 1694 depends on AS_HAS_ARMV8_4 1695 help 1696 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1697 range of input addresses. 1698 1699 The feature introduces new assembly instructions, and they were 1700 support when binutils >= 2.30. 1701 1702endmenu 1703 1704menu "ARMv8.5 architectural features" 1705 1706config AS_HAS_ARMV8_5 1707 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1708 1709config ARM64_BTI 1710 bool "Branch Target Identification support" 1711 default y 1712 help 1713 Branch Target Identification (part of the ARMv8.5 Extensions) 1714 provides a mechanism to limit the set of locations to which computed 1715 branch instructions such as BR or BLR can jump. 1716 1717 To make use of BTI on CPUs that support it, say Y. 1718 1719 BTI is intended to provide complementary protection to other control 1720 flow integrity protection mechanisms, such as the Pointer 1721 authentication mechanism provided as part of the ARMv8.3 Extensions. 1722 For this reason, it does not make sense to enable this option without 1723 also enabling support for pointer authentication. Thus, when 1724 enabling this option you should also select ARM64_PTR_AUTH=y. 1725 1726 Userspace binaries must also be specifically compiled to make use of 1727 this mechanism. If you say N here or the hardware does not support 1728 BTI, such binaries can still run, but you get no additional 1729 enforcement of branch destinations. 1730 1731config ARM64_BTI_KERNEL 1732 bool "Use Branch Target Identification for kernel" 1733 default y 1734 depends on ARM64_BTI 1735 depends on ARM64_PTR_AUTH_KERNEL 1736 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1737 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1738 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1739 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1740 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1741 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1742 help 1743 Build the kernel with Branch Target Identification annotations 1744 and enable enforcement of this for kernel code. When this option 1745 is enabled and the system supports BTI all kernel code including 1746 modular code must have BTI enabled. 1747 1748config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1749 # GCC 9 or later, clang 8 or later 1750 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1751 1752config ARM64_E0PD 1753 bool "Enable support for E0PD" 1754 default y 1755 help 1756 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1757 that EL0 accesses made via TTBR1 always fault in constant time, 1758 providing similar benefits to KASLR as those provided by KPTI, but 1759 with lower overhead and without disrupting legitimate access to 1760 kernel memory such as SPE. 1761 1762 This option enables E0PD for TTBR1 where available. 1763 1764config ARCH_RANDOM 1765 bool "Enable support for random number generation" 1766 default y 1767 help 1768 Random number generation (part of the ARMv8.5 Extensions) 1769 provides a high bandwidth, cryptographically secure 1770 hardware random number generator. 1771 1772config ARM64_AS_HAS_MTE 1773 # Initial support for MTE went in binutils 2.32.0, checked with 1774 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1775 # as a late addition to the final architecture spec (LDGM/STGM) 1776 # is only supported in the newer 2.32.x and 2.33 binutils 1777 # versions, hence the extra "stgm" instruction check below. 1778 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1779 1780config ARM64_MTE 1781 bool "Memory Tagging Extension support" 1782 default y 1783 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1784 depends on AS_HAS_ARMV8_5 1785 depends on AS_HAS_LSE_ATOMICS 1786 # Required for tag checking in the uaccess routines 1787 depends on ARM64_PAN 1788 select ARCH_USES_HIGH_VMA_FLAGS 1789 help 1790 Memory Tagging (part of the ARMv8.5 Extensions) provides 1791 architectural support for run-time, always-on detection of 1792 various classes of memory error to aid with software debugging 1793 to eliminate vulnerabilities arising from memory-unsafe 1794 languages. 1795 1796 This option enables the support for the Memory Tagging 1797 Extension at EL0 (i.e. for userspace). 1798 1799 Selecting this option allows the feature to be detected at 1800 runtime. Any secondary CPU not implementing this feature will 1801 not be allowed a late bring-up. 1802 1803 Userspace binaries that want to use this feature must 1804 explicitly opt in. The mechanism for the userspace is 1805 described in: 1806 1807 Documentation/arm64/memory-tagging-extension.rst. 1808 1809endmenu 1810 1811menu "ARMv8.7 architectural features" 1812 1813config ARM64_EPAN 1814 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 1815 default y 1816 depends on ARM64_PAN 1817 help 1818 Enhanced Privileged Access Never (EPAN) allows Privileged 1819 Access Never to be used with Execute-only mappings. 1820 1821 The feature is detected at runtime, and will remain disabled 1822 if the cpu does not implement the feature. 1823endmenu 1824 1825config ARM64_SVE 1826 bool "ARM Scalable Vector Extension support" 1827 default y 1828 help 1829 The Scalable Vector Extension (SVE) is an extension to the AArch64 1830 execution state which complements and extends the SIMD functionality 1831 of the base architecture to support much larger vectors and to enable 1832 additional vectorisation opportunities. 1833 1834 To enable use of this extension on CPUs that implement it, say Y. 1835 1836 On CPUs that support the SVE2 extensions, this option will enable 1837 those too. 1838 1839 Note that for architectural reasons, firmware _must_ implement SVE 1840 support when running on SVE capable hardware. The required support 1841 is present in: 1842 1843 * version 1.5 and later of the ARM Trusted Firmware 1844 * the AArch64 boot wrapper since commit 5e1261e08abf 1845 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1846 1847 For other firmware implementations, consult the firmware documentation 1848 or vendor. 1849 1850 If you need the kernel to boot on SVE-capable hardware with broken 1851 firmware, you may need to say N here until you get your firmware 1852 fixed. Otherwise, you may experience firmware panics or lockups when 1853 booting the kernel. If unsure and you are not observing these 1854 symptoms, you should assume that it is safe to say Y. 1855 1856config ARM64_MODULE_PLTS 1857 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1858 depends on MODULES 1859 select HAVE_MOD_ARCH_SPECIFIC 1860 help 1861 Allocate PLTs when loading modules so that jumps and calls whose 1862 targets are too far away for their relative offsets to be encoded 1863 in the instructions themselves can be bounced via veneers in the 1864 module's PLT. This allows modules to be allocated in the generic 1865 vmalloc area after the dedicated module memory area has been 1866 exhausted. 1867 1868 When running with address space randomization (KASLR), the module 1869 region itself may be too far away for ordinary relative jumps and 1870 calls, and so in that case, module PLTs are required and cannot be 1871 disabled. 1872 1873 Specific errata workaround(s) might also force module PLTs to be 1874 enabled (ARM64_ERRATUM_843419). 1875 1876config ARM64_PSEUDO_NMI 1877 bool "Support for NMI-like interrupts" 1878 select ARM_GIC_V3 1879 help 1880 Adds support for mimicking Non-Maskable Interrupts through the use of 1881 GIC interrupt priority. This support requires version 3 or later of 1882 ARM GIC. 1883 1884 This high priority configuration for interrupts needs to be 1885 explicitly enabled by setting the kernel parameter 1886 "irqchip.gicv3_pseudo_nmi" to 1. 1887 1888 If unsure, say N 1889 1890if ARM64_PSEUDO_NMI 1891config ARM64_DEBUG_PRIORITY_MASKING 1892 bool "Debug interrupt priority masking" 1893 help 1894 This adds runtime checks to functions enabling/disabling 1895 interrupts when using priority masking. The additional checks verify 1896 the validity of ICC_PMR_EL1 when calling concerned functions. 1897 1898 If unsure, say N 1899endif 1900 1901config RELOCATABLE 1902 bool "Build a relocatable kernel image" if EXPERT 1903 select ARCH_HAS_RELR 1904 default y 1905 help 1906 This builds the kernel as a Position Independent Executable (PIE), 1907 which retains all relocation metadata required to relocate the 1908 kernel binary at runtime to a different virtual address than the 1909 address it was linked at. 1910 Since AArch64 uses the RELA relocation format, this requires a 1911 relocation pass at runtime even if the kernel is loaded at the 1912 same address it was linked at. 1913 1914config RANDOMIZE_BASE 1915 bool "Randomize the address of the kernel image" 1916 select ARM64_MODULE_PLTS if MODULES 1917 select RELOCATABLE 1918 help 1919 Randomizes the virtual address at which the kernel image is 1920 loaded, as a security feature that deters exploit attempts 1921 relying on knowledge of the location of kernel internals. 1922 1923 It is the bootloader's job to provide entropy, by passing a 1924 random u64 value in /chosen/kaslr-seed at kernel entry. 1925 1926 When booting via the UEFI stub, it will invoke the firmware's 1927 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1928 to the kernel proper. In addition, it will randomise the physical 1929 location of the kernel Image as well. 1930 1931 If unsure, say N. 1932 1933config RANDOMIZE_MODULE_REGION_FULL 1934 bool "Randomize the module region over a 2 GB range" 1935 depends on RANDOMIZE_BASE 1936 default y 1937 help 1938 Randomizes the location of the module region inside a 2 GB window 1939 covering the core kernel. This way, it is less likely for modules 1940 to leak information about the location of core kernel data structures 1941 but it does imply that function calls between modules and the core 1942 kernel will need to be resolved via veneers in the module PLT. 1943 1944 When this option is not set, the module region will be randomized over 1945 a limited range that contains the [_stext, _etext] interval of the 1946 core kernel, so branch relocations are almost always in range unless 1947 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 1948 particular case of region exhaustion, modules might be able to fall 1949 back to a larger 2GB area. 1950 1951config CC_HAVE_STACKPROTECTOR_SYSREG 1952 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1953 1954config STACKPROTECTOR_PER_TASK 1955 def_bool y 1956 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1957 1958endmenu 1959 1960menu "Boot options" 1961 1962config ARM64_ACPI_PARKING_PROTOCOL 1963 bool "Enable support for the ARM64 ACPI parking protocol" 1964 depends on ACPI 1965 help 1966 Enable support for the ARM64 ACPI parking protocol. If disabled 1967 the kernel will not allow booting through the ARM64 ACPI parking 1968 protocol even if the corresponding data is present in the ACPI 1969 MADT table. 1970 1971config CMDLINE 1972 string "Default kernel command string" 1973 default "" 1974 help 1975 Provide a set of default command-line options at build time by 1976 entering them here. As a minimum, you should specify the the 1977 root device (e.g. root=/dev/nfs). 1978 1979choice 1980 prompt "Kernel command line type" if CMDLINE != "" 1981 default CMDLINE_FROM_BOOTLOADER 1982 help 1983 Choose how the kernel will handle the provided default kernel 1984 command line string. 1985 1986config CMDLINE_FROM_BOOTLOADER 1987 bool "Use bootloader kernel arguments if available" 1988 help 1989 Uses the command-line options passed by the boot loader. If 1990 the boot loader doesn't provide any, the default kernel command 1991 string provided in CMDLINE will be used. 1992 1993config CMDLINE_FORCE 1994 bool "Always use the default kernel command string" 1995 help 1996 Always use the default kernel command string, even if the boot 1997 loader passes other arguments to the kernel. 1998 This is useful if you cannot or don't want to change the 1999 command-line options your boot loader passes to the kernel. 2000 2001endchoice 2002 2003config EFI_STUB 2004 bool 2005 2006config EFI 2007 bool "UEFI runtime support" 2008 depends on OF && !CPU_BIG_ENDIAN 2009 depends on KERNEL_MODE_NEON 2010 select ARCH_SUPPORTS_ACPI 2011 select LIBFDT 2012 select UCS2_STRING 2013 select EFI_PARAMS_FROM_FDT 2014 select EFI_RUNTIME_WRAPPERS 2015 select EFI_STUB 2016 select EFI_GENERIC_STUB 2017 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2018 default y 2019 help 2020 This option provides support for runtime services provided 2021 by UEFI firmware (such as non-volatile variables, realtime 2022 clock, and platform reset). A UEFI stub is also provided to 2023 allow the kernel to be booted as an EFI application. This 2024 is only useful on systems that have UEFI firmware. 2025 2026config DMI 2027 bool "Enable support for SMBIOS (DMI) tables" 2028 depends on EFI 2029 default y 2030 help 2031 This enables SMBIOS/DMI feature for systems. 2032 2033 This option is only useful on systems that have UEFI firmware. 2034 However, even with this option, the resultant kernel should 2035 continue to boot on existing non-UEFI platforms. 2036 2037endmenu 2038 2039config SYSVIPC_COMPAT 2040 def_bool y 2041 depends on COMPAT && SYSVIPC 2042 2043menu "Power management options" 2044 2045source "kernel/power/Kconfig" 2046 2047config ARCH_HIBERNATION_POSSIBLE 2048 def_bool y 2049 depends on CPU_PM 2050 2051config ARCH_HIBERNATION_HEADER 2052 def_bool y 2053 depends on HIBERNATION 2054 2055config ARCH_SUSPEND_POSSIBLE 2056 def_bool y 2057 2058endmenu 2059 2060menu "CPU Power Management" 2061 2062source "drivers/cpuidle/Kconfig" 2063 2064source "drivers/cpufreq/Kconfig" 2065 2066endmenu 2067 2068source "drivers/acpi/Kconfig" 2069 2070source "arch/arm64/kvm/Kconfig" 2071 2072if CRYPTO 2073source "arch/arm64/crypto/Kconfig" 2074endif 2075