1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_IORT if ACPI 9 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 10 select ACPI_MCFG if (ACPI && PCI) 11 select ACPI_SPCR_TABLE if ACPI 12 select ACPI_PPTT if ACPI 13 select ARCH_HAS_DEBUG_WX 14 select ARCH_BINFMT_ELF_EXTRA_PHDRS 15 select ARCH_BINFMT_ELF_STATE 16 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CURRENT_STACK_POINTER 24 select ARCH_HAS_DEBUG_VIRTUAL 25 select ARCH_HAS_DEBUG_VM_PGTABLE 26 select ARCH_HAS_DMA_PREP_COHERENT 27 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 28 select ARCH_HAS_FAST_MULTIPLIER 29 select ARCH_HAS_FORTIFY_SOURCE 30 select ARCH_HAS_GCOV_PROFILE_ALL 31 select ARCH_HAS_GIGANTIC_PAGE 32 select ARCH_HAS_KCOV 33 select ARCH_HAS_KEEPINITRD 34 select ARCH_HAS_MEMBARRIER_SYNC_CORE 35 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 36 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 37 select ARCH_HAS_PTE_DEVMAP 38 select ARCH_HAS_PTE_SPECIAL 39 select ARCH_HAS_SETUP_DMA_OPS 40 select ARCH_HAS_SET_DIRECT_MAP 41 select ARCH_HAS_SET_MEMORY 42 select ARCH_STACKWALK 43 select ARCH_HAS_STRICT_KERNEL_RWX 44 select ARCH_HAS_STRICT_MODULE_RWX 45 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 46 select ARCH_HAS_SYNC_DMA_FOR_CPU 47 select ARCH_HAS_SYSCALL_WRAPPER 48 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 49 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 50 select ARCH_HAS_ZONE_DMA_SET if EXPERT 51 select ARCH_HAVE_ELF_PROT 52 select ARCH_HAVE_NMI_SAFE_CMPXCHG 53 select ARCH_HAVE_TRACE_MMIO_ACCESS 54 select ARCH_INLINE_READ_LOCK if !PREEMPTION 55 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 56 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 57 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 58 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 59 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 60 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 61 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 62 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 63 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 64 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 65 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 66 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 67 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 68 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 69 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 70 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 71 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 72 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 73 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_KEEP_MEMBLOCK 81 select ARCH_USE_CMPXCHG_LOCKREF 82 select ARCH_USE_GNU_PROPERTY 83 select ARCH_USE_MEMTEST 84 select ARCH_USE_QUEUED_RWLOCKS 85 select ARCH_USE_QUEUED_SPINLOCKS 86 select ARCH_USE_SYM_ANNOTATIONS 87 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 88 select ARCH_SUPPORTS_HUGETLBFS 89 select ARCH_SUPPORTS_MEMORY_FAILURE 90 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 91 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 92 select ARCH_SUPPORTS_LTO_CLANG_THIN 93 select ARCH_SUPPORTS_CFI_CLANG 94 select ARCH_SUPPORTS_ATOMIC_RMW 95 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 96 select ARCH_SUPPORTS_NUMA_BALANCING 97 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 98 select ARCH_SUPPORTS_PER_VMA_LOCK 99 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 100 select ARCH_WANT_DEFAULT_BPF_JIT 101 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 102 select ARCH_WANT_FRAME_POINTERS 103 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 104 select ARCH_WANT_LD_ORPHAN_WARN 105 select ARCH_WANTS_NO_INSTR 106 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 107 select ARCH_HAS_UBSAN_SANITIZE_ALL 108 select ARM_AMBA 109 select ARM_ARCH_TIMER 110 select ARM_GIC 111 select AUDIT_ARCH_COMPAT_GENERIC 112 select ARM_GIC_V2M if PCI 113 select ARM_GIC_V3 114 select ARM_GIC_V3_ITS if PCI 115 select ARM_PSCI_FW 116 select BUILDTIME_TABLE_SORT 117 select CLONE_BACKWARDS 118 select COMMON_CLK 119 select CPU_PM if (SUSPEND || CPU_IDLE) 120 select CRC32 121 select DCACHE_WORD_ACCESS 122 select DYNAMIC_FTRACE if FUNCTION_TRACER 123 select DMA_DIRECT_REMAP 124 select EDAC_SUPPORT 125 select FRAME_POINTER 126 select FUNCTION_ALIGNMENT_4B 127 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 128 select GENERIC_ALLOCATOR 129 select GENERIC_ARCH_TOPOLOGY 130 select GENERIC_CLOCKEVENTS_BROADCAST 131 select GENERIC_CPU_AUTOPROBE 132 select GENERIC_CPU_VULNERABILITIES 133 select GENERIC_EARLY_IOREMAP 134 select GENERIC_IDLE_POLL_SETUP 135 select GENERIC_IOREMAP 136 select GENERIC_IRQ_IPI 137 select GENERIC_IRQ_PROBE 138 select GENERIC_IRQ_SHOW 139 select GENERIC_IRQ_SHOW_LEVEL 140 select GENERIC_LIB_DEVMEM_IS_ALLOWED 141 select GENERIC_PCI_IOMAP 142 select GENERIC_PTDUMP 143 select GENERIC_SCHED_CLOCK 144 select GENERIC_SMP_IDLE_THREAD 145 select GENERIC_TIME_VSYSCALL 146 select GENERIC_GETTIMEOFDAY 147 select GENERIC_VDSO_TIME_NS 148 select HARDIRQS_SW_RESEND 149 select HAVE_MOVE_PMD 150 select HAVE_MOVE_PUD 151 select HAVE_PCI 152 select HAVE_ACPI_APEI if (ACPI && EFI) 153 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 154 select HAVE_ARCH_AUDITSYSCALL 155 select HAVE_ARCH_BITREVERSE 156 select HAVE_ARCH_COMPILER_H 157 select HAVE_ARCH_HUGE_VMALLOC 158 select HAVE_ARCH_HUGE_VMAP 159 select HAVE_ARCH_JUMP_LABEL 160 select HAVE_ARCH_JUMP_LABEL_RELATIVE 161 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 162 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 163 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 164 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 165 # Some instrumentation may be unsound, hence EXPERT 166 select HAVE_ARCH_KCSAN if EXPERT 167 select HAVE_ARCH_KFENCE 168 select HAVE_ARCH_KGDB 169 select HAVE_ARCH_MMAP_RND_BITS 170 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 171 select HAVE_ARCH_PREL32_RELOCATIONS 172 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 173 select HAVE_ARCH_SECCOMP_FILTER 174 select HAVE_ARCH_STACKLEAK 175 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 176 select HAVE_ARCH_TRACEHOOK 177 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 178 select HAVE_ARCH_VMAP_STACK 179 select HAVE_ARM_SMCCC 180 select HAVE_ASM_MODVERSIONS 181 select HAVE_EBPF_JIT 182 select HAVE_C_RECORDMCOUNT 183 select HAVE_CMPXCHG_DOUBLE 184 select HAVE_CMPXCHG_LOCAL 185 select HAVE_CONTEXT_TRACKING_USER 186 select HAVE_DEBUG_KMEMLEAK 187 select HAVE_DMA_CONTIGUOUS 188 select HAVE_DYNAMIC_FTRACE 189 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 190 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 191 !CC_OPTIMIZE_FOR_SIZE) 192 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 193 if DYNAMIC_FTRACE_WITH_ARGS 194 select HAVE_EFFICIENT_UNALIGNED_ACCESS 195 select HAVE_FAST_GUP 196 select HAVE_FTRACE_MCOUNT_RECORD 197 select HAVE_FUNCTION_TRACER 198 select HAVE_FUNCTION_ERROR_INJECTION 199 select HAVE_FUNCTION_GRAPH_TRACER 200 select HAVE_GCC_PLUGINS 201 select HAVE_HW_BREAKPOINT if PERF_EVENTS 202 select HAVE_IOREMAP_PROT 203 select HAVE_IRQ_TIME_ACCOUNTING 204 select HAVE_KVM 205 select HAVE_NMI 206 select HAVE_PERF_EVENTS 207 select HAVE_PERF_REGS 208 select HAVE_PERF_USER_STACK_DUMP 209 select HAVE_PREEMPT_DYNAMIC_KEY 210 select HAVE_REGS_AND_STACK_ACCESS_API 211 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 212 select HAVE_FUNCTION_ARG_ACCESS_API 213 select MMU_GATHER_RCU_TABLE_FREE 214 select HAVE_RSEQ 215 select HAVE_STACKPROTECTOR 216 select HAVE_SYSCALL_TRACEPOINTS 217 select HAVE_KPROBES 218 select HAVE_KRETPROBES 219 select HAVE_GENERIC_VDSO 220 select IRQ_DOMAIN 221 select IRQ_FORCED_THREADING 222 select KASAN_VMALLOC if KASAN 223 select MODULES_USE_ELF_RELA 224 select NEED_DMA_MAP_STATE 225 select NEED_SG_DMA_LENGTH 226 select OF 227 select OF_EARLY_FLATTREE 228 select PCI_DOMAINS_GENERIC if PCI 229 select PCI_ECAM if (ACPI && PCI) 230 select PCI_SYSCALL if PCI 231 select POWER_RESET 232 select POWER_SUPPLY 233 select SPARSE_IRQ 234 select SWIOTLB 235 select SYSCTL_EXCEPTION_TRACE 236 select THREAD_INFO_IN_TASK 237 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 238 select TRACE_IRQFLAGS_SUPPORT 239 select TRACE_IRQFLAGS_NMI_SUPPORT 240 select HAVE_SOFTIRQ_ON_OWN_STACK 241 help 242 ARM 64-bit (AArch64) Linux support. 243 244config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 245 def_bool CC_IS_CLANG 246 # https://github.com/ClangBuiltLinux/linux/issues/1507 247 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 248 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 249 250config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 251 def_bool CC_IS_GCC 252 depends on $(cc-option,-fpatchable-function-entry=2) 253 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 254 255config 64BIT 256 def_bool y 257 258config MMU 259 def_bool y 260 261config ARM64_PAGE_SHIFT 262 int 263 default 16 if ARM64_64K_PAGES 264 default 14 if ARM64_16K_PAGES 265 default 12 266 267config ARM64_CONT_PTE_SHIFT 268 int 269 default 5 if ARM64_64K_PAGES 270 default 7 if ARM64_16K_PAGES 271 default 4 272 273config ARM64_CONT_PMD_SHIFT 274 int 275 default 5 if ARM64_64K_PAGES 276 default 5 if ARM64_16K_PAGES 277 default 4 278 279config ARCH_MMAP_RND_BITS_MIN 280 default 14 if ARM64_64K_PAGES 281 default 16 if ARM64_16K_PAGES 282 default 18 283 284# max bits determined by the following formula: 285# VA_BITS - PAGE_SHIFT - 3 286config ARCH_MMAP_RND_BITS_MAX 287 default 19 if ARM64_VA_BITS=36 288 default 24 if ARM64_VA_BITS=39 289 default 27 if ARM64_VA_BITS=42 290 default 30 if ARM64_VA_BITS=47 291 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 292 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 293 default 33 if ARM64_VA_BITS=48 294 default 14 if ARM64_64K_PAGES 295 default 16 if ARM64_16K_PAGES 296 default 18 297 298config ARCH_MMAP_RND_COMPAT_BITS_MIN 299 default 7 if ARM64_64K_PAGES 300 default 9 if ARM64_16K_PAGES 301 default 11 302 303config ARCH_MMAP_RND_COMPAT_BITS_MAX 304 default 16 305 306config NO_IOPORT_MAP 307 def_bool y if !PCI 308 309config STACKTRACE_SUPPORT 310 def_bool y 311 312config ILLEGAL_POINTER_VALUE 313 hex 314 default 0xdead000000000000 315 316config LOCKDEP_SUPPORT 317 def_bool y 318 319config GENERIC_BUG 320 def_bool y 321 depends on BUG 322 323config GENERIC_BUG_RELATIVE_POINTERS 324 def_bool y 325 depends on GENERIC_BUG 326 327config GENERIC_HWEIGHT 328 def_bool y 329 330config GENERIC_CSUM 331 def_bool y 332 333config GENERIC_CALIBRATE_DELAY 334 def_bool y 335 336config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 337 def_bool y 338 339config SMP 340 def_bool y 341 342config KERNEL_MODE_NEON 343 def_bool y 344 345config FIX_EARLYCON_MEM 346 def_bool y 347 348config PGTABLE_LEVELS 349 int 350 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 351 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 352 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 353 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 354 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 355 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 356 357config ARCH_SUPPORTS_UPROBES 358 def_bool y 359 360config ARCH_PROC_KCORE_TEXT 361 def_bool y 362 363config BROKEN_GAS_INST 364 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 365 366config KASAN_SHADOW_OFFSET 367 hex 368 depends on KASAN_GENERIC || KASAN_SW_TAGS 369 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 370 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 371 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 372 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 373 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 374 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 375 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 376 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 377 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 378 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 379 default 0xffffffffffffffff 380 381config UNWIND_TABLES 382 bool 383 384source "arch/arm64/Kconfig.platforms" 385 386menu "Kernel Features" 387 388menu "ARM errata workarounds via the alternatives framework" 389 390config ARM64_WORKAROUND_CLEAN_CACHE 391 bool 392 393config ARM64_ERRATUM_826319 394 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 395 default y 396 select ARM64_WORKAROUND_CLEAN_CACHE 397 help 398 This option adds an alternative code sequence to work around ARM 399 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 400 AXI master interface and an L2 cache. 401 402 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 403 and is unable to accept a certain write via this interface, it will 404 not progress on read data presented on the read data channel and the 405 system can deadlock. 406 407 The workaround promotes data cache clean instructions to 408 data cache clean-and-invalidate. 409 Please note that this does not necessarily enable the workaround, 410 as it depends on the alternative framework, which will only patch 411 the kernel if an affected CPU is detected. 412 413 If unsure, say Y. 414 415config ARM64_ERRATUM_827319 416 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 417 default y 418 select ARM64_WORKAROUND_CLEAN_CACHE 419 help 420 This option adds an alternative code sequence to work around ARM 421 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 422 master interface and an L2 cache. 423 424 Under certain conditions this erratum can cause a clean line eviction 425 to occur at the same time as another transaction to the same address 426 on the AMBA 5 CHI interface, which can cause data corruption if the 427 interconnect reorders the two transactions. 428 429 The workaround promotes data cache clean instructions to 430 data cache clean-and-invalidate. 431 Please note that this does not necessarily enable the workaround, 432 as it depends on the alternative framework, which will only patch 433 the kernel if an affected CPU is detected. 434 435 If unsure, say Y. 436 437config ARM64_ERRATUM_824069 438 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 439 default y 440 select ARM64_WORKAROUND_CLEAN_CACHE 441 help 442 This option adds an alternative code sequence to work around ARM 443 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 444 to a coherent interconnect. 445 446 If a Cortex-A53 processor is executing a store or prefetch for 447 write instruction at the same time as a processor in another 448 cluster is executing a cache maintenance operation to the same 449 address, then this erratum might cause a clean cache line to be 450 incorrectly marked as dirty. 451 452 The workaround promotes data cache clean instructions to 453 data cache clean-and-invalidate. 454 Please note that this option does not necessarily enable the 455 workaround, as it depends on the alternative framework, which will 456 only patch the kernel if an affected CPU is detected. 457 458 If unsure, say Y. 459 460config ARM64_ERRATUM_819472 461 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 462 default y 463 select ARM64_WORKAROUND_CLEAN_CACHE 464 help 465 This option adds an alternative code sequence to work around ARM 466 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 467 present when it is connected to a coherent interconnect. 468 469 If the processor is executing a load and store exclusive sequence at 470 the same time as a processor in another cluster is executing a cache 471 maintenance operation to the same address, then this erratum might 472 cause data corruption. 473 474 The workaround promotes data cache clean instructions to 475 data cache clean-and-invalidate. 476 Please note that this does not necessarily enable the workaround, 477 as it depends on the alternative framework, which will only patch 478 the kernel if an affected CPU is detected. 479 480 If unsure, say Y. 481 482config ARM64_ERRATUM_832075 483 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 484 default y 485 help 486 This option adds an alternative code sequence to work around ARM 487 erratum 832075 on Cortex-A57 parts up to r1p2. 488 489 Affected Cortex-A57 parts might deadlock when exclusive load/store 490 instructions to Write-Back memory are mixed with Device loads. 491 492 The workaround is to promote device loads to use Load-Acquire 493 semantics. 494 Please note that this does not necessarily enable the workaround, 495 as it depends on the alternative framework, which will only patch 496 the kernel if an affected CPU is detected. 497 498 If unsure, say Y. 499 500config ARM64_ERRATUM_834220 501 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 502 depends on KVM 503 default y 504 help 505 This option adds an alternative code sequence to work around ARM 506 erratum 834220 on Cortex-A57 parts up to r1p2. 507 508 Affected Cortex-A57 parts might report a Stage 2 translation 509 fault as the result of a Stage 1 fault for load crossing a 510 page boundary when there is a permission or device memory 511 alignment fault at Stage 1 and a translation fault at Stage 2. 512 513 The workaround is to verify that the Stage 1 translation 514 doesn't generate a fault before handling the Stage 2 fault. 515 Please note that this does not necessarily enable the workaround, 516 as it depends on the alternative framework, which will only patch 517 the kernel if an affected CPU is detected. 518 519 If unsure, say Y. 520 521config ARM64_ERRATUM_1742098 522 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 523 depends on COMPAT 524 default y 525 help 526 This option removes the AES hwcap for aarch32 user-space to 527 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 528 529 Affected parts may corrupt the AES state if an interrupt is 530 taken between a pair of AES instructions. These instructions 531 are only present if the cryptography extensions are present. 532 All software should have a fallback implementation for CPUs 533 that don't implement the cryptography extensions. 534 535 If unsure, say Y. 536 537config ARM64_ERRATUM_845719 538 bool "Cortex-A53: 845719: a load might read incorrect data" 539 depends on COMPAT 540 default y 541 help 542 This option adds an alternative code sequence to work around ARM 543 erratum 845719 on Cortex-A53 parts up to r0p4. 544 545 When running a compat (AArch32) userspace on an affected Cortex-A53 546 part, a load at EL0 from a virtual address that matches the bottom 32 547 bits of the virtual address used by a recent load at (AArch64) EL1 548 might return incorrect data. 549 550 The workaround is to write the contextidr_el1 register on exception 551 return to a 32-bit task. 552 Please note that this does not necessarily enable the workaround, 553 as it depends on the alternative framework, which will only patch 554 the kernel if an affected CPU is detected. 555 556 If unsure, say Y. 557 558config ARM64_ERRATUM_843419 559 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 560 default y 561 select ARM64_MODULE_PLTS if MODULES 562 help 563 This option links the kernel with '--fix-cortex-a53-843419' and 564 enables PLT support to replace certain ADRP instructions, which can 565 cause subsequent memory accesses to use an incorrect address on 566 Cortex-A53 parts up to r0p4. 567 568 If unsure, say Y. 569 570config ARM64_LD_HAS_FIX_ERRATUM_843419 571 def_bool $(ld-option,--fix-cortex-a53-843419) 572 573config ARM64_ERRATUM_1024718 574 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 575 default y 576 help 577 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 578 579 Affected Cortex-A55 cores (all revisions) could cause incorrect 580 update of the hardware dirty bit when the DBM/AP bits are updated 581 without a break-before-make. The workaround is to disable the usage 582 of hardware DBM locally on the affected cores. CPUs not affected by 583 this erratum will continue to use the feature. 584 585 If unsure, say Y. 586 587config ARM64_ERRATUM_1418040 588 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 589 default y 590 depends on COMPAT 591 help 592 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 593 errata 1188873 and 1418040. 594 595 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 596 cause register corruption when accessing the timer registers 597 from AArch32 userspace. 598 599 If unsure, say Y. 600 601config ARM64_WORKAROUND_SPECULATIVE_AT 602 bool 603 604config ARM64_ERRATUM_1165522 605 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 606 default y 607 select ARM64_WORKAROUND_SPECULATIVE_AT 608 help 609 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 610 611 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 612 corrupted TLBs by speculating an AT instruction during a guest 613 context switch. 614 615 If unsure, say Y. 616 617config ARM64_ERRATUM_1319367 618 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 619 default y 620 select ARM64_WORKAROUND_SPECULATIVE_AT 621 help 622 This option adds work arounds for ARM Cortex-A57 erratum 1319537 623 and A72 erratum 1319367 624 625 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 626 speculating an AT instruction during a guest context switch. 627 628 If unsure, say Y. 629 630config ARM64_ERRATUM_1530923 631 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 632 default y 633 select ARM64_WORKAROUND_SPECULATIVE_AT 634 help 635 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 636 637 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 638 corrupted TLBs by speculating an AT instruction during a guest 639 context switch. 640 641 If unsure, say Y. 642 643config ARM64_WORKAROUND_REPEAT_TLBI 644 bool 645 646config ARM64_ERRATUM_2441007 647 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 648 default y 649 select ARM64_WORKAROUND_REPEAT_TLBI 650 help 651 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 652 653 Under very rare circumstances, affected Cortex-A55 CPUs 654 may not handle a race between a break-before-make sequence on one 655 CPU, and another CPU accessing the same page. This could allow a 656 store to a page that has been unmapped. 657 658 Work around this by adding the affected CPUs to the list that needs 659 TLB sequences to be done twice. 660 661 If unsure, say Y. 662 663config ARM64_ERRATUM_1286807 664 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 665 default y 666 select ARM64_WORKAROUND_REPEAT_TLBI 667 help 668 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 669 670 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 671 address for a cacheable mapping of a location is being 672 accessed by a core while another core is remapping the virtual 673 address to a new physical page using the recommended 674 break-before-make sequence, then under very rare circumstances 675 TLBI+DSB completes before a read using the translation being 676 invalidated has been observed by other observers. The 677 workaround repeats the TLBI+DSB operation. 678 679config ARM64_ERRATUM_1463225 680 bool "Cortex-A76: Software Step might prevent interrupt recognition" 681 default y 682 help 683 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 684 685 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 686 of a system call instruction (SVC) can prevent recognition of 687 subsequent interrupts when software stepping is disabled in the 688 exception handler of the system call and either kernel debugging 689 is enabled or VHE is in use. 690 691 Work around the erratum by triggering a dummy step exception 692 when handling a system call from a task that is being stepped 693 in a VHE configuration of the kernel. 694 695 If unsure, say Y. 696 697config ARM64_ERRATUM_1542419 698 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 699 default y 700 help 701 This option adds a workaround for ARM Neoverse-N1 erratum 702 1542419. 703 704 Affected Neoverse-N1 cores could execute a stale instruction when 705 modified by another CPU. The workaround depends on a firmware 706 counterpart. 707 708 Workaround the issue by hiding the DIC feature from EL0. This 709 forces user-space to perform cache maintenance. 710 711 If unsure, say Y. 712 713config ARM64_ERRATUM_1508412 714 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 715 default y 716 help 717 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 718 719 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 720 of a store-exclusive or read of PAR_EL1 and a load with device or 721 non-cacheable memory attributes. The workaround depends on a firmware 722 counterpart. 723 724 KVM guests must also have the workaround implemented or they can 725 deadlock the system. 726 727 Work around the issue by inserting DMB SY barriers around PAR_EL1 728 register reads and warning KVM users. The DMB barrier is sufficient 729 to prevent a speculative PAR_EL1 read. 730 731 If unsure, say Y. 732 733config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 734 bool 735 736config ARM64_ERRATUM_2051678 737 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 738 default y 739 help 740 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 741 Affected Cortex-A510 might not respect the ordering rules for 742 hardware update of the page table's dirty bit. The workaround 743 is to not enable the feature on affected CPUs. 744 745 If unsure, say Y. 746 747config ARM64_ERRATUM_2077057 748 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 749 default y 750 help 751 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 752 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 753 expected, but a Pointer Authentication trap is taken instead. The 754 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 755 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 756 757 This can only happen when EL2 is stepping EL1. 758 759 When these conditions occur, the SPSR_EL2 value is unchanged from the 760 previous guest entry, and can be restored from the in-memory copy. 761 762 If unsure, say Y. 763 764config ARM64_ERRATUM_2658417 765 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 766 default y 767 help 768 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 769 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 770 BFMMLA or VMMLA instructions in rare circumstances when a pair of 771 A510 CPUs are using shared neon hardware. As the sharing is not 772 discoverable by the kernel, hide the BF16 HWCAP to indicate that 773 user-space should not be using these instructions. 774 775 If unsure, say Y. 776 777config ARM64_ERRATUM_2119858 778 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 779 default y 780 depends on CORESIGHT_TRBE 781 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 782 help 783 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 784 785 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 786 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 787 the event of a WRAP event. 788 789 Work around the issue by always making sure we move the TRBPTR_EL1 by 790 256 bytes before enabling the buffer and filling the first 256 bytes of 791 the buffer with ETM ignore packets upon disabling. 792 793 If unsure, say Y. 794 795config ARM64_ERRATUM_2139208 796 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 797 default y 798 depends on CORESIGHT_TRBE 799 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 800 help 801 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 802 803 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 804 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 805 the event of a WRAP event. 806 807 Work around the issue by always making sure we move the TRBPTR_EL1 by 808 256 bytes before enabling the buffer and filling the first 256 bytes of 809 the buffer with ETM ignore packets upon disabling. 810 811 If unsure, say Y. 812 813config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 814 bool 815 816config ARM64_ERRATUM_2054223 817 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 818 default y 819 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 820 help 821 Enable workaround for ARM Cortex-A710 erratum 2054223 822 823 Affected cores may fail to flush the trace data on a TSB instruction, when 824 the PE is in trace prohibited state. This will cause losing a few bytes 825 of the trace cached. 826 827 Workaround is to issue two TSB consecutively on affected cores. 828 829 If unsure, say Y. 830 831config ARM64_ERRATUM_2067961 832 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 833 default y 834 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 835 help 836 Enable workaround for ARM Neoverse-N2 erratum 2067961 837 838 Affected cores may fail to flush the trace data on a TSB instruction, when 839 the PE is in trace prohibited state. This will cause losing a few bytes 840 of the trace cached. 841 842 Workaround is to issue two TSB consecutively on affected cores. 843 844 If unsure, say Y. 845 846config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 847 bool 848 849config ARM64_ERRATUM_2253138 850 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 851 depends on CORESIGHT_TRBE 852 default y 853 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 854 help 855 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 856 857 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 858 for TRBE. Under some conditions, the TRBE might generate a write to the next 859 virtually addressed page following the last page of the TRBE address space 860 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 861 862 Work around this in the driver by always making sure that there is a 863 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 864 865 If unsure, say Y. 866 867config ARM64_ERRATUM_2224489 868 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 869 depends on CORESIGHT_TRBE 870 default y 871 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 872 help 873 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 874 875 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 876 for TRBE. Under some conditions, the TRBE might generate a write to the next 877 virtually addressed page following the last page of the TRBE address space 878 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 879 880 Work around this in the driver by always making sure that there is a 881 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 882 883 If unsure, say Y. 884 885config ARM64_ERRATUM_2441009 886 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 887 default y 888 select ARM64_WORKAROUND_REPEAT_TLBI 889 help 890 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 891 892 Under very rare circumstances, affected Cortex-A510 CPUs 893 may not handle a race between a break-before-make sequence on one 894 CPU, and another CPU accessing the same page. This could allow a 895 store to a page that has been unmapped. 896 897 Work around this by adding the affected CPUs to the list that needs 898 TLB sequences to be done twice. 899 900 If unsure, say Y. 901 902config ARM64_ERRATUM_2064142 903 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 904 depends on CORESIGHT_TRBE 905 default y 906 help 907 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 908 909 Affected Cortex-A510 core might fail to write into system registers after the 910 TRBE has been disabled. Under some conditions after the TRBE has been disabled 911 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 912 and TRBTRG_EL1 will be ignored and will not be effected. 913 914 Work around this in the driver by executing TSB CSYNC and DSB after collection 915 is stopped and before performing a system register write to one of the affected 916 registers. 917 918 If unsure, say Y. 919 920config ARM64_ERRATUM_2038923 921 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 922 depends on CORESIGHT_TRBE 923 default y 924 help 925 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 926 927 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 928 prohibited within the CPU. As a result, the trace buffer or trace buffer state 929 might be corrupted. This happens after TRBE buffer has been enabled by setting 930 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 931 execution changes from a context, in which trace is prohibited to one where it 932 isn't, or vice versa. In these mentioned conditions, the view of whether trace 933 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 934 the trace buffer state might be corrupted. 935 936 Work around this in the driver by preventing an inconsistent view of whether the 937 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 938 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 939 two ISB instructions if no ERET is to take place. 940 941 If unsure, say Y. 942 943config ARM64_ERRATUM_1902691 944 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 945 depends on CORESIGHT_TRBE 946 default y 947 help 948 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 949 950 Affected Cortex-A510 core might cause trace data corruption, when being written 951 into the memory. Effectively TRBE is broken and hence cannot be used to capture 952 trace data. 953 954 Work around this problem in the driver by just preventing TRBE initialization on 955 affected cpus. The firmware must have disabled the access to TRBE for the kernel 956 on such implementations. This will cover the kernel for any firmware that doesn't 957 do this already. 958 959 If unsure, say Y. 960 961config ARM64_ERRATUM_2457168 962 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 963 depends on ARM64_AMU_EXTN 964 default y 965 help 966 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 967 968 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 969 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 970 incorrectly giving a significantly higher output value. 971 972 Work around this problem by returning 0 when reading the affected counter in 973 key locations that results in disabling all users of this counter. This effect 974 is the same to firmware disabling affected counters. 975 976 If unsure, say Y. 977 978config ARM64_ERRATUM_2645198 979 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 980 default y 981 help 982 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 983 984 If a Cortex-A715 cpu sees a page mapping permissions change from executable 985 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 986 next instruction abort caused by permission fault. 987 988 Only user-space does executable to non-executable permission transition via 989 mprotect() system call. Workaround the problem by doing a break-before-make 990 TLB invalidation, for all changes to executable user space mappings. 991 992 If unsure, say Y. 993 994config CAVIUM_ERRATUM_22375 995 bool "Cavium erratum 22375, 24313" 996 default y 997 help 998 Enable workaround for errata 22375 and 24313. 999 1000 This implements two gicv3-its errata workarounds for ThunderX. Both 1001 with a small impact affecting only ITS table allocation. 1002 1003 erratum 22375: only alloc 8MB table size 1004 erratum 24313: ignore memory access type 1005 1006 The fixes are in ITS initialization and basically ignore memory access 1007 type and table size provided by the TYPER and BASER registers. 1008 1009 If unsure, say Y. 1010 1011config CAVIUM_ERRATUM_23144 1012 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1013 depends on NUMA 1014 default y 1015 help 1016 ITS SYNC command hang for cross node io and collections/cpu mapping. 1017 1018 If unsure, say Y. 1019 1020config CAVIUM_ERRATUM_23154 1021 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1022 default y 1023 help 1024 The ThunderX GICv3 implementation requires a modified version for 1025 reading the IAR status to ensure data synchronization 1026 (access to icc_iar1_el1 is not sync'ed before and after). 1027 1028 It also suffers from erratum 38545 (also present on Marvell's 1029 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1030 spuriously presented to the CPU interface. 1031 1032 If unsure, say Y. 1033 1034config CAVIUM_ERRATUM_27456 1035 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1036 default y 1037 help 1038 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1039 instructions may cause the icache to become corrupted if it 1040 contains data for a non-current ASID. The fix is to 1041 invalidate the icache when changing the mm context. 1042 1043 If unsure, say Y. 1044 1045config CAVIUM_ERRATUM_30115 1046 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1047 default y 1048 help 1049 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1050 1.2, and T83 Pass 1.0, KVM guest execution may disable 1051 interrupts in host. Trapping both GICv3 group-0 and group-1 1052 accesses sidesteps the issue. 1053 1054 If unsure, say Y. 1055 1056config CAVIUM_TX2_ERRATUM_219 1057 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1058 default y 1059 help 1060 On Cavium ThunderX2, a load, store or prefetch instruction between a 1061 TTBR update and the corresponding context synchronizing operation can 1062 cause a spurious Data Abort to be delivered to any hardware thread in 1063 the CPU core. 1064 1065 Work around the issue by avoiding the problematic code sequence and 1066 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1067 trap handler performs the corresponding register access, skips the 1068 instruction and ensures context synchronization by virtue of the 1069 exception return. 1070 1071 If unsure, say Y. 1072 1073config FUJITSU_ERRATUM_010001 1074 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1075 default y 1076 help 1077 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1078 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1079 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1080 This fault occurs under a specific hardware condition when a 1081 load/store instruction performs an address translation using: 1082 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1083 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1084 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1085 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1086 1087 The workaround is to ensure these bits are clear in TCR_ELx. 1088 The workaround only affects the Fujitsu-A64FX. 1089 1090 If unsure, say Y. 1091 1092config HISILICON_ERRATUM_161600802 1093 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1094 default y 1095 help 1096 The HiSilicon Hip07 SoC uses the wrong redistributor base 1097 when issued ITS commands such as VMOVP and VMAPP, and requires 1098 a 128kB offset to be applied to the target address in this commands. 1099 1100 If unsure, say Y. 1101 1102config QCOM_FALKOR_ERRATUM_1003 1103 bool "Falkor E1003: Incorrect translation due to ASID change" 1104 default y 1105 help 1106 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1107 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1108 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1109 then only for entries in the walk cache, since the leaf translation 1110 is unchanged. Work around the erratum by invalidating the walk cache 1111 entries for the trampoline before entering the kernel proper. 1112 1113config QCOM_FALKOR_ERRATUM_1009 1114 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1115 default y 1116 select ARM64_WORKAROUND_REPEAT_TLBI 1117 help 1118 On Falkor v1, the CPU may prematurely complete a DSB following a 1119 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1120 one more time to fix the issue. 1121 1122 If unsure, say Y. 1123 1124config QCOM_QDF2400_ERRATUM_0065 1125 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1126 default y 1127 help 1128 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1129 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1130 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1131 1132 If unsure, say Y. 1133 1134config QCOM_FALKOR_ERRATUM_E1041 1135 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1136 default y 1137 help 1138 Falkor CPU may speculatively fetch instructions from an improper 1139 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1140 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1141 1142 If unsure, say Y. 1143 1144config NVIDIA_CARMEL_CNP_ERRATUM 1145 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1146 default y 1147 help 1148 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1149 invalidate shared TLB entries installed by a different core, as it would 1150 on standard ARM cores. 1151 1152 If unsure, say Y. 1153 1154config SOCIONEXT_SYNQUACER_PREITS 1155 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1156 default y 1157 help 1158 Socionext Synquacer SoCs implement a separate h/w block to generate 1159 MSI doorbell writes with non-zero values for the device ID. 1160 1161 If unsure, say Y. 1162 1163endmenu # "ARM errata workarounds via the alternatives framework" 1164 1165choice 1166 prompt "Page size" 1167 default ARM64_4K_PAGES 1168 help 1169 Page size (translation granule) configuration. 1170 1171config ARM64_4K_PAGES 1172 bool "4KB" 1173 help 1174 This feature enables 4KB pages support. 1175 1176config ARM64_16K_PAGES 1177 bool "16KB" 1178 help 1179 The system will use 16KB pages support. AArch32 emulation 1180 requires applications compiled with 16K (or a multiple of 16K) 1181 aligned segments. 1182 1183config ARM64_64K_PAGES 1184 bool "64KB" 1185 help 1186 This feature enables 64KB pages support (4KB by default) 1187 allowing only two levels of page tables and faster TLB 1188 look-up. AArch32 emulation requires applications compiled 1189 with 64K aligned segments. 1190 1191endchoice 1192 1193choice 1194 prompt "Virtual address space size" 1195 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1196 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1197 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1198 help 1199 Allows choosing one of multiple possible virtual address 1200 space sizes. The level of translation table is determined by 1201 a combination of page size and virtual address space size. 1202 1203config ARM64_VA_BITS_36 1204 bool "36-bit" if EXPERT 1205 depends on ARM64_16K_PAGES 1206 1207config ARM64_VA_BITS_39 1208 bool "39-bit" 1209 depends on ARM64_4K_PAGES 1210 1211config ARM64_VA_BITS_42 1212 bool "42-bit" 1213 depends on ARM64_64K_PAGES 1214 1215config ARM64_VA_BITS_47 1216 bool "47-bit" 1217 depends on ARM64_16K_PAGES 1218 1219config ARM64_VA_BITS_48 1220 bool "48-bit" 1221 1222config ARM64_VA_BITS_52 1223 bool "52-bit" 1224 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1225 help 1226 Enable 52-bit virtual addressing for userspace when explicitly 1227 requested via a hint to mmap(). The kernel will also use 52-bit 1228 virtual addresses for its own mappings (provided HW support for 1229 this feature is available, otherwise it reverts to 48-bit). 1230 1231 NOTE: Enabling 52-bit virtual addressing in conjunction with 1232 ARMv8.3 Pointer Authentication will result in the PAC being 1233 reduced from 7 bits to 3 bits, which may have a significant 1234 impact on its susceptibility to brute-force attacks. 1235 1236 If unsure, select 48-bit virtual addressing instead. 1237 1238endchoice 1239 1240config ARM64_FORCE_52BIT 1241 bool "Force 52-bit virtual addresses for userspace" 1242 depends on ARM64_VA_BITS_52 && EXPERT 1243 help 1244 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1245 to maintain compatibility with older software by providing 48-bit VAs 1246 unless a hint is supplied to mmap. 1247 1248 This configuration option disables the 48-bit compatibility logic, and 1249 forces all userspace addresses to be 52-bit on HW that supports it. One 1250 should only enable this configuration option for stress testing userspace 1251 memory management code. If unsure say N here. 1252 1253config ARM64_VA_BITS 1254 int 1255 default 36 if ARM64_VA_BITS_36 1256 default 39 if ARM64_VA_BITS_39 1257 default 42 if ARM64_VA_BITS_42 1258 default 47 if ARM64_VA_BITS_47 1259 default 48 if ARM64_VA_BITS_48 1260 default 52 if ARM64_VA_BITS_52 1261 1262choice 1263 prompt "Physical address space size" 1264 default ARM64_PA_BITS_48 1265 help 1266 Choose the maximum physical address range that the kernel will 1267 support. 1268 1269config ARM64_PA_BITS_48 1270 bool "48-bit" 1271 1272config ARM64_PA_BITS_52 1273 bool "52-bit (ARMv8.2)" 1274 depends on ARM64_64K_PAGES 1275 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1276 help 1277 Enable support for a 52-bit physical address space, introduced as 1278 part of the ARMv8.2-LPA extension. 1279 1280 With this enabled, the kernel will also continue to work on CPUs that 1281 do not support ARMv8.2-LPA, but with some added memory overhead (and 1282 minor performance overhead). 1283 1284endchoice 1285 1286config ARM64_PA_BITS 1287 int 1288 default 48 if ARM64_PA_BITS_48 1289 default 52 if ARM64_PA_BITS_52 1290 1291choice 1292 prompt "Endianness" 1293 default CPU_LITTLE_ENDIAN 1294 help 1295 Select the endianness of data accesses performed by the CPU. Userspace 1296 applications will need to be compiled and linked for the endianness 1297 that is selected here. 1298 1299config CPU_BIG_ENDIAN 1300 bool "Build big-endian kernel" 1301 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1302 help 1303 Say Y if you plan on running a kernel with a big-endian userspace. 1304 1305config CPU_LITTLE_ENDIAN 1306 bool "Build little-endian kernel" 1307 help 1308 Say Y if you plan on running a kernel with a little-endian userspace. 1309 This is usually the case for distributions targeting arm64. 1310 1311endchoice 1312 1313config SCHED_MC 1314 bool "Multi-core scheduler support" 1315 help 1316 Multi-core scheduler support improves the CPU scheduler's decision 1317 making when dealing with multi-core CPU chips at a cost of slightly 1318 increased overhead in some places. If unsure say N here. 1319 1320config SCHED_CLUSTER 1321 bool "Cluster scheduler support" 1322 help 1323 Cluster scheduler support improves the CPU scheduler's decision 1324 making when dealing with machines that have clusters of CPUs. 1325 Cluster usually means a couple of CPUs which are placed closely 1326 by sharing mid-level caches, last-level cache tags or internal 1327 busses. 1328 1329config SCHED_SMT 1330 bool "SMT scheduler support" 1331 help 1332 Improves the CPU scheduler's decision making when dealing with 1333 MultiThreading at a cost of slightly increased overhead in some 1334 places. If unsure say N here. 1335 1336config NR_CPUS 1337 int "Maximum number of CPUs (2-4096)" 1338 range 2 4096 1339 default "256" 1340 1341config HOTPLUG_CPU 1342 bool "Support for hot-pluggable CPUs" 1343 select GENERIC_IRQ_MIGRATION 1344 help 1345 Say Y here to experiment with turning CPUs off and on. CPUs 1346 can be controlled through /sys/devices/system/cpu. 1347 1348# Common NUMA Features 1349config NUMA 1350 bool "NUMA Memory Allocation and Scheduler Support" 1351 select GENERIC_ARCH_NUMA 1352 select ACPI_NUMA if ACPI 1353 select OF_NUMA 1354 select HAVE_SETUP_PER_CPU_AREA 1355 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1356 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1357 select USE_PERCPU_NUMA_NODE_ID 1358 help 1359 Enable NUMA (Non-Uniform Memory Access) support. 1360 1361 The kernel will try to allocate memory used by a CPU on the 1362 local memory of the CPU and add some more 1363 NUMA awareness to the kernel. 1364 1365config NODES_SHIFT 1366 int "Maximum NUMA Nodes (as a power of 2)" 1367 range 1 10 1368 default "4" 1369 depends on NUMA 1370 help 1371 Specify the maximum number of NUMA Nodes available on the target 1372 system. Increases memory reserved to accommodate various tables. 1373 1374source "kernel/Kconfig.hz" 1375 1376config ARCH_SPARSEMEM_ENABLE 1377 def_bool y 1378 select SPARSEMEM_VMEMMAP_ENABLE 1379 select SPARSEMEM_VMEMMAP 1380 1381config HW_PERF_EVENTS 1382 def_bool y 1383 depends on ARM_PMU 1384 1385# Supported by clang >= 7.0 or GCC >= 12.0.0 1386config CC_HAVE_SHADOW_CALL_STACK 1387 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1388 1389config PARAVIRT 1390 bool "Enable paravirtualization code" 1391 help 1392 This changes the kernel so it can modify itself when it is run 1393 under a hypervisor, potentially improving performance significantly 1394 over full virtualization. 1395 1396config PARAVIRT_TIME_ACCOUNTING 1397 bool "Paravirtual steal time accounting" 1398 select PARAVIRT 1399 help 1400 Select this option to enable fine granularity task steal time 1401 accounting. Time spent executing other tasks in parallel with 1402 the current vCPU is discounted from the vCPU power. To account for 1403 that, there can be a small performance impact. 1404 1405 If in doubt, say N here. 1406 1407config KEXEC 1408 depends on PM_SLEEP_SMP 1409 select KEXEC_CORE 1410 bool "kexec system call" 1411 help 1412 kexec is a system call that implements the ability to shutdown your 1413 current kernel, and to start another kernel. It is like a reboot 1414 but it is independent of the system firmware. And like a reboot 1415 you can start any kernel with it, not just Linux. 1416 1417config KEXEC_FILE 1418 bool "kexec file based system call" 1419 select KEXEC_CORE 1420 select HAVE_IMA_KEXEC if IMA 1421 help 1422 This is new version of kexec system call. This system call is 1423 file based and takes file descriptors as system call argument 1424 for kernel and initramfs as opposed to list of segments as 1425 accepted by previous system call. 1426 1427config KEXEC_SIG 1428 bool "Verify kernel signature during kexec_file_load() syscall" 1429 depends on KEXEC_FILE 1430 help 1431 Select this option to verify a signature with loaded kernel 1432 image. If configured, any attempt of loading a image without 1433 valid signature will fail. 1434 1435 In addition to that option, you need to enable signature 1436 verification for the corresponding kernel image type being 1437 loaded in order for this to work. 1438 1439config KEXEC_IMAGE_VERIFY_SIG 1440 bool "Enable Image signature verification support" 1441 default y 1442 depends on KEXEC_SIG 1443 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1444 help 1445 Enable Image signature verification support. 1446 1447comment "Support for PE file signature verification disabled" 1448 depends on KEXEC_SIG 1449 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1450 1451config CRASH_DUMP 1452 bool "Build kdump crash kernel" 1453 help 1454 Generate crash dump after being started by kexec. This should 1455 be normally only set in special crash dump kernels which are 1456 loaded in the main kernel with kexec-tools into a specially 1457 reserved region and then later executed after a crash by 1458 kdump/kexec. 1459 1460 For more details see Documentation/admin-guide/kdump/kdump.rst 1461 1462config TRANS_TABLE 1463 def_bool y 1464 depends on HIBERNATION || KEXEC_CORE 1465 1466config XEN_DOM0 1467 def_bool y 1468 depends on XEN 1469 1470config XEN 1471 bool "Xen guest support on ARM64" 1472 depends on ARM64 && OF 1473 select SWIOTLB_XEN 1474 select PARAVIRT 1475 help 1476 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1477 1478# include/linux/mmzone.h requires the following to be true: 1479# 1480# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1481# 1482# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1483# 1484# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1485# ----+-------------------+--------------+-----------------+--------------------+ 1486# 4K | 27 | 12 | 15 | 10 | 1487# 16K | 27 | 14 | 13 | 11 | 1488# 64K | 29 | 16 | 13 | 13 | 1489config ARCH_FORCE_MAX_ORDER 1490 int "Order of maximal physically contiguous allocations" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES) 1491 default "13" if ARM64_64K_PAGES 1492 default "11" if ARM64_16K_PAGES 1493 default "10" 1494 help 1495 The kernel page allocator limits the size of maximal physically 1496 contiguous allocations. The limit is called MAX_ORDER and it 1497 defines the maximal power of two of number of pages that can be 1498 allocated as a single contiguous block. This option allows 1499 overriding the default setting when ability to allocate very 1500 large blocks of physically contiguous memory is required. 1501 1502 The maximal size of allocation cannot exceed the size of the 1503 section, so the value of MAX_ORDER should satisfy 1504 1505 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1506 1507 Don't change if unsure. 1508 1509config UNMAP_KERNEL_AT_EL0 1510 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1511 default y 1512 help 1513 Speculation attacks against some high-performance processors can 1514 be used to bypass MMU permission checks and leak kernel data to 1515 userspace. This can be defended against by unmapping the kernel 1516 when running in userspace, mapping it back in on exception entry 1517 via a trampoline page in the vector table. 1518 1519 If unsure, say Y. 1520 1521config MITIGATE_SPECTRE_BRANCH_HISTORY 1522 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1523 default y 1524 help 1525 Speculation attacks against some high-performance processors can 1526 make use of branch history to influence future speculation. 1527 When taking an exception from user-space, a sequence of branches 1528 or a firmware call overwrites the branch history. 1529 1530config RODATA_FULL_DEFAULT_ENABLED 1531 bool "Apply r/o permissions of VM areas also to their linear aliases" 1532 default y 1533 help 1534 Apply read-only attributes of VM areas to the linear alias of 1535 the backing pages as well. This prevents code or read-only data 1536 from being modified (inadvertently or intentionally) via another 1537 mapping of the same memory page. This additional enhancement can 1538 be turned off at runtime by passing rodata=[off|on] (and turned on 1539 with rodata=full if this option is set to 'n') 1540 1541 This requires the linear region to be mapped down to pages, 1542 which may adversely affect performance in some cases. 1543 1544config ARM64_SW_TTBR0_PAN 1545 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1546 help 1547 Enabling this option prevents the kernel from accessing 1548 user-space memory directly by pointing TTBR0_EL1 to a reserved 1549 zeroed area and reserved ASID. The user access routines 1550 restore the valid TTBR0_EL1 temporarily. 1551 1552config ARM64_TAGGED_ADDR_ABI 1553 bool "Enable the tagged user addresses syscall ABI" 1554 default y 1555 help 1556 When this option is enabled, user applications can opt in to a 1557 relaxed ABI via prctl() allowing tagged addresses to be passed 1558 to system calls as pointer arguments. For details, see 1559 Documentation/arm64/tagged-address-abi.rst. 1560 1561menuconfig COMPAT 1562 bool "Kernel support for 32-bit EL0" 1563 depends on ARM64_4K_PAGES || EXPERT 1564 select HAVE_UID16 1565 select OLD_SIGSUSPEND3 1566 select COMPAT_OLD_SIGACTION 1567 help 1568 This option enables support for a 32-bit EL0 running under a 64-bit 1569 kernel at EL1. AArch32-specific components such as system calls, 1570 the user helper functions, VFP support and the ptrace interface are 1571 handled appropriately by the kernel. 1572 1573 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1574 that you will only be able to execute AArch32 binaries that were compiled 1575 with page size aligned segments. 1576 1577 If you want to execute 32-bit userspace applications, say Y. 1578 1579if COMPAT 1580 1581config KUSER_HELPERS 1582 bool "Enable kuser helpers page for 32-bit applications" 1583 default y 1584 help 1585 Warning: disabling this option may break 32-bit user programs. 1586 1587 Provide kuser helpers to compat tasks. The kernel provides 1588 helper code to userspace in read only form at a fixed location 1589 to allow userspace to be independent of the CPU type fitted to 1590 the system. This permits binaries to be run on ARMv4 through 1591 to ARMv8 without modification. 1592 1593 See Documentation/arm/kernel_user_helpers.rst for details. 1594 1595 However, the fixed address nature of these helpers can be used 1596 by ROP (return orientated programming) authors when creating 1597 exploits. 1598 1599 If all of the binaries and libraries which run on your platform 1600 are built specifically for your platform, and make no use of 1601 these helpers, then you can turn this option off to hinder 1602 such exploits. However, in that case, if a binary or library 1603 relying on those helpers is run, it will not function correctly. 1604 1605 Say N here only if you are absolutely certain that you do not 1606 need these helpers; otherwise, the safe option is to say Y. 1607 1608config COMPAT_VDSO 1609 bool "Enable vDSO for 32-bit applications" 1610 depends on !CPU_BIG_ENDIAN 1611 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1612 select GENERIC_COMPAT_VDSO 1613 default y 1614 help 1615 Place in the process address space of 32-bit applications an 1616 ELF shared object providing fast implementations of gettimeofday 1617 and clock_gettime. 1618 1619 You must have a 32-bit build of glibc 2.22 or later for programs 1620 to seamlessly take advantage of this. 1621 1622config THUMB2_COMPAT_VDSO 1623 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1624 depends on COMPAT_VDSO 1625 default y 1626 help 1627 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1628 otherwise with '-marm'. 1629 1630config COMPAT_ALIGNMENT_FIXUPS 1631 bool "Fix up misaligned multi-word loads and stores in user space" 1632 1633menuconfig ARMV8_DEPRECATED 1634 bool "Emulate deprecated/obsolete ARMv8 instructions" 1635 depends on SYSCTL 1636 help 1637 Legacy software support may require certain instructions 1638 that have been deprecated or obsoleted in the architecture. 1639 1640 Enable this config to enable selective emulation of these 1641 features. 1642 1643 If unsure, say Y 1644 1645if ARMV8_DEPRECATED 1646 1647config SWP_EMULATION 1648 bool "Emulate SWP/SWPB instructions" 1649 help 1650 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1651 they are always undefined. Say Y here to enable software 1652 emulation of these instructions for userspace using LDXR/STXR. 1653 This feature can be controlled at runtime with the abi.swp 1654 sysctl which is disabled by default. 1655 1656 In some older versions of glibc [<=2.8] SWP is used during futex 1657 trylock() operations with the assumption that the code will not 1658 be preempted. This invalid assumption may be more likely to fail 1659 with SWP emulation enabled, leading to deadlock of the user 1660 application. 1661 1662 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1663 on an external transaction monitoring block called a global 1664 monitor to maintain update atomicity. If your system does not 1665 implement a global monitor, this option can cause programs that 1666 perform SWP operations to uncached memory to deadlock. 1667 1668 If unsure, say Y 1669 1670config CP15_BARRIER_EMULATION 1671 bool "Emulate CP15 Barrier instructions" 1672 help 1673 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1674 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1675 strongly recommended to use the ISB, DSB, and DMB 1676 instructions instead. 1677 1678 Say Y here to enable software emulation of these 1679 instructions for AArch32 userspace code. When this option is 1680 enabled, CP15 barrier usage is traced which can help 1681 identify software that needs updating. This feature can be 1682 controlled at runtime with the abi.cp15_barrier sysctl. 1683 1684 If unsure, say Y 1685 1686config SETEND_EMULATION 1687 bool "Emulate SETEND instruction" 1688 help 1689 The SETEND instruction alters the data-endianness of the 1690 AArch32 EL0, and is deprecated in ARMv8. 1691 1692 Say Y here to enable software emulation of the instruction 1693 for AArch32 userspace code. This feature can be controlled 1694 at runtime with the abi.setend sysctl. 1695 1696 Note: All the cpus on the system must have mixed endian support at EL0 1697 for this feature to be enabled. If a new CPU - which doesn't support mixed 1698 endian - is hotplugged in after this feature has been enabled, there could 1699 be unexpected results in the applications. 1700 1701 If unsure, say Y 1702endif # ARMV8_DEPRECATED 1703 1704endif # COMPAT 1705 1706menu "ARMv8.1 architectural features" 1707 1708config ARM64_HW_AFDBM 1709 bool "Support for hardware updates of the Access and Dirty page flags" 1710 default y 1711 help 1712 The ARMv8.1 architecture extensions introduce support for 1713 hardware updates of the access and dirty information in page 1714 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1715 capable processors, accesses to pages with PTE_AF cleared will 1716 set this bit instead of raising an access flag fault. 1717 Similarly, writes to read-only pages with the DBM bit set will 1718 clear the read-only bit (AP[2]) instead of raising a 1719 permission fault. 1720 1721 Kernels built with this configuration option enabled continue 1722 to work on pre-ARMv8.1 hardware and the performance impact is 1723 minimal. If unsure, say Y. 1724 1725config ARM64_PAN 1726 bool "Enable support for Privileged Access Never (PAN)" 1727 default y 1728 help 1729 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1730 prevents the kernel or hypervisor from accessing user-space (EL0) 1731 memory directly. 1732 1733 Choosing this option will cause any unprotected (not using 1734 copy_to_user et al) memory access to fail with a permission fault. 1735 1736 The feature is detected at runtime, and will remain as a 'nop' 1737 instruction if the cpu does not implement the feature. 1738 1739config AS_HAS_LDAPR 1740 def_bool $(as-instr,.arch_extension rcpc) 1741 1742config AS_HAS_LSE_ATOMICS 1743 def_bool $(as-instr,.arch_extension lse) 1744 1745config ARM64_LSE_ATOMICS 1746 bool 1747 default ARM64_USE_LSE_ATOMICS 1748 depends on AS_HAS_LSE_ATOMICS 1749 1750config ARM64_USE_LSE_ATOMICS 1751 bool "Atomic instructions" 1752 default y 1753 help 1754 As part of the Large System Extensions, ARMv8.1 introduces new 1755 atomic instructions that are designed specifically to scale in 1756 very large systems. 1757 1758 Say Y here to make use of these instructions for the in-kernel 1759 atomic routines. This incurs a small overhead on CPUs that do 1760 not support these instructions and requires the kernel to be 1761 built with binutils >= 2.25 in order for the new instructions 1762 to be used. 1763 1764endmenu # "ARMv8.1 architectural features" 1765 1766menu "ARMv8.2 architectural features" 1767 1768config AS_HAS_ARMV8_2 1769 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1770 1771config AS_HAS_SHA3 1772 def_bool $(as-instr,.arch armv8.2-a+sha3) 1773 1774config ARM64_PMEM 1775 bool "Enable support for persistent memory" 1776 select ARCH_HAS_PMEM_API 1777 select ARCH_HAS_UACCESS_FLUSHCACHE 1778 help 1779 Say Y to enable support for the persistent memory API based on the 1780 ARMv8.2 DCPoP feature. 1781 1782 The feature is detected at runtime, and the kernel will use DC CVAC 1783 operations if DC CVAP is not supported (following the behaviour of 1784 DC CVAP itself if the system does not define a point of persistence). 1785 1786config ARM64_RAS_EXTN 1787 bool "Enable support for RAS CPU Extensions" 1788 default y 1789 help 1790 CPUs that support the Reliability, Availability and Serviceability 1791 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1792 errors, classify them and report them to software. 1793 1794 On CPUs with these extensions system software can use additional 1795 barriers to determine if faults are pending and read the 1796 classification from a new set of registers. 1797 1798 Selecting this feature will allow the kernel to use these barriers 1799 and access the new registers if the system supports the extension. 1800 Platform RAS features may additionally depend on firmware support. 1801 1802config ARM64_CNP 1803 bool "Enable support for Common Not Private (CNP) translations" 1804 default y 1805 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1806 help 1807 Common Not Private (CNP) allows translation table entries to 1808 be shared between different PEs in the same inner shareable 1809 domain, so the hardware can use this fact to optimise the 1810 caching of such entries in the TLB. 1811 1812 Selecting this option allows the CNP feature to be detected 1813 at runtime, and does not affect PEs that do not implement 1814 this feature. 1815 1816endmenu # "ARMv8.2 architectural features" 1817 1818menu "ARMv8.3 architectural features" 1819 1820config ARM64_PTR_AUTH 1821 bool "Enable support for pointer authentication" 1822 default y 1823 help 1824 Pointer authentication (part of the ARMv8.3 Extensions) provides 1825 instructions for signing and authenticating pointers against secret 1826 keys, which can be used to mitigate Return Oriented Programming (ROP) 1827 and other attacks. 1828 1829 This option enables these instructions at EL0 (i.e. for userspace). 1830 Choosing this option will cause the kernel to initialise secret keys 1831 for each process at exec() time, with these keys being 1832 context-switched along with the process. 1833 1834 The feature is detected at runtime. If the feature is not present in 1835 hardware it will not be advertised to userspace/KVM guest nor will it 1836 be enabled. 1837 1838 If the feature is present on the boot CPU but not on a late CPU, then 1839 the late CPU will be parked. Also, if the boot CPU does not have 1840 address auth and the late CPU has then the late CPU will still boot 1841 but with the feature disabled. On such a system, this option should 1842 not be selected. 1843 1844config ARM64_PTR_AUTH_KERNEL 1845 bool "Use pointer authentication for kernel" 1846 default y 1847 depends on ARM64_PTR_AUTH 1848 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1849 # Modern compilers insert a .note.gnu.property section note for PAC 1850 # which is only understood by binutils starting with version 2.33.1. 1851 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1852 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1853 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1854 help 1855 If the compiler supports the -mbranch-protection or 1856 -msign-return-address flag (e.g. GCC 7 or later), then this option 1857 will cause the kernel itself to be compiled with return address 1858 protection. In this case, and if the target hardware is known to 1859 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1860 disabled with minimal loss of protection. 1861 1862 This feature works with FUNCTION_GRAPH_TRACER option only if 1863 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1864 1865config CC_HAS_BRANCH_PROT_PAC_RET 1866 # GCC 9 or later, clang 8 or later 1867 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1868 1869config CC_HAS_SIGN_RETURN_ADDRESS 1870 # GCC 7, 8 1871 def_bool $(cc-option,-msign-return-address=all) 1872 1873config AS_HAS_ARMV8_3 1874 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1875 1876config AS_HAS_CFI_NEGATE_RA_STATE 1877 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1878 1879endmenu # "ARMv8.3 architectural features" 1880 1881menu "ARMv8.4 architectural features" 1882 1883config ARM64_AMU_EXTN 1884 bool "Enable support for the Activity Monitors Unit CPU extension" 1885 default y 1886 help 1887 The activity monitors extension is an optional extension introduced 1888 by the ARMv8.4 CPU architecture. This enables support for version 1 1889 of the activity monitors architecture, AMUv1. 1890 1891 To enable the use of this extension on CPUs that implement it, say Y. 1892 1893 Note that for architectural reasons, firmware _must_ implement AMU 1894 support when running on CPUs that present the activity monitors 1895 extension. The required support is present in: 1896 * Version 1.5 and later of the ARM Trusted Firmware 1897 1898 For kernels that have this configuration enabled but boot with broken 1899 firmware, you may need to say N here until the firmware is fixed. 1900 Otherwise you may experience firmware panics or lockups when 1901 accessing the counter registers. Even if you are not observing these 1902 symptoms, the values returned by the register reads might not 1903 correctly reflect reality. Most commonly, the value read will be 0, 1904 indicating that the counter is not enabled. 1905 1906config AS_HAS_ARMV8_4 1907 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1908 1909config ARM64_TLB_RANGE 1910 bool "Enable support for tlbi range feature" 1911 default y 1912 depends on AS_HAS_ARMV8_4 1913 help 1914 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1915 range of input addresses. 1916 1917 The feature introduces new assembly instructions, and they were 1918 support when binutils >= 2.30. 1919 1920endmenu # "ARMv8.4 architectural features" 1921 1922menu "ARMv8.5 architectural features" 1923 1924config AS_HAS_ARMV8_5 1925 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1926 1927config ARM64_BTI 1928 bool "Branch Target Identification support" 1929 default y 1930 help 1931 Branch Target Identification (part of the ARMv8.5 Extensions) 1932 provides a mechanism to limit the set of locations to which computed 1933 branch instructions such as BR or BLR can jump. 1934 1935 To make use of BTI on CPUs that support it, say Y. 1936 1937 BTI is intended to provide complementary protection to other control 1938 flow integrity protection mechanisms, such as the Pointer 1939 authentication mechanism provided as part of the ARMv8.3 Extensions. 1940 For this reason, it does not make sense to enable this option without 1941 also enabling support for pointer authentication. Thus, when 1942 enabling this option you should also select ARM64_PTR_AUTH=y. 1943 1944 Userspace binaries must also be specifically compiled to make use of 1945 this mechanism. If you say N here or the hardware does not support 1946 BTI, such binaries can still run, but you get no additional 1947 enforcement of branch destinations. 1948 1949config ARM64_BTI_KERNEL 1950 bool "Use Branch Target Identification for kernel" 1951 default y 1952 depends on ARM64_BTI 1953 depends on ARM64_PTR_AUTH_KERNEL 1954 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1955 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1956 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1957 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1958 depends on !CC_IS_GCC 1959 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1960 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1961 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1962 help 1963 Build the kernel with Branch Target Identification annotations 1964 and enable enforcement of this for kernel code. When this option 1965 is enabled and the system supports BTI all kernel code including 1966 modular code must have BTI enabled. 1967 1968config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1969 # GCC 9 or later, clang 8 or later 1970 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1971 1972config ARM64_E0PD 1973 bool "Enable support for E0PD" 1974 default y 1975 help 1976 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1977 that EL0 accesses made via TTBR1 always fault in constant time, 1978 providing similar benefits to KASLR as those provided by KPTI, but 1979 with lower overhead and without disrupting legitimate access to 1980 kernel memory such as SPE. 1981 1982 This option enables E0PD for TTBR1 where available. 1983 1984config ARM64_AS_HAS_MTE 1985 # Initial support for MTE went in binutils 2.32.0, checked with 1986 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1987 # as a late addition to the final architecture spec (LDGM/STGM) 1988 # is only supported in the newer 2.32.x and 2.33 binutils 1989 # versions, hence the extra "stgm" instruction check below. 1990 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1991 1992config ARM64_MTE 1993 bool "Memory Tagging Extension support" 1994 default y 1995 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1996 depends on AS_HAS_ARMV8_5 1997 depends on AS_HAS_LSE_ATOMICS 1998 # Required for tag checking in the uaccess routines 1999 depends on ARM64_PAN 2000 select ARCH_HAS_SUBPAGE_FAULTS 2001 select ARCH_USES_HIGH_VMA_FLAGS 2002 select ARCH_USES_PG_ARCH_X 2003 help 2004 Memory Tagging (part of the ARMv8.5 Extensions) provides 2005 architectural support for run-time, always-on detection of 2006 various classes of memory error to aid with software debugging 2007 to eliminate vulnerabilities arising from memory-unsafe 2008 languages. 2009 2010 This option enables the support for the Memory Tagging 2011 Extension at EL0 (i.e. for userspace). 2012 2013 Selecting this option allows the feature to be detected at 2014 runtime. Any secondary CPU not implementing this feature will 2015 not be allowed a late bring-up. 2016 2017 Userspace binaries that want to use this feature must 2018 explicitly opt in. The mechanism for the userspace is 2019 described in: 2020 2021 Documentation/arm64/memory-tagging-extension.rst. 2022 2023endmenu # "ARMv8.5 architectural features" 2024 2025menu "ARMv8.7 architectural features" 2026 2027config ARM64_EPAN 2028 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2029 default y 2030 depends on ARM64_PAN 2031 help 2032 Enhanced Privileged Access Never (EPAN) allows Privileged 2033 Access Never to be used with Execute-only mappings. 2034 2035 The feature is detected at runtime, and will remain disabled 2036 if the cpu does not implement the feature. 2037endmenu # "ARMv8.7 architectural features" 2038 2039config ARM64_SVE 2040 bool "ARM Scalable Vector Extension support" 2041 default y 2042 help 2043 The Scalable Vector Extension (SVE) is an extension to the AArch64 2044 execution state which complements and extends the SIMD functionality 2045 of the base architecture to support much larger vectors and to enable 2046 additional vectorisation opportunities. 2047 2048 To enable use of this extension on CPUs that implement it, say Y. 2049 2050 On CPUs that support the SVE2 extensions, this option will enable 2051 those too. 2052 2053 Note that for architectural reasons, firmware _must_ implement SVE 2054 support when running on SVE capable hardware. The required support 2055 is present in: 2056 2057 * version 1.5 and later of the ARM Trusted Firmware 2058 * the AArch64 boot wrapper since commit 5e1261e08abf 2059 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2060 2061 For other firmware implementations, consult the firmware documentation 2062 or vendor. 2063 2064 If you need the kernel to boot on SVE-capable hardware with broken 2065 firmware, you may need to say N here until you get your firmware 2066 fixed. Otherwise, you may experience firmware panics or lockups when 2067 booting the kernel. If unsure and you are not observing these 2068 symptoms, you should assume that it is safe to say Y. 2069 2070config ARM64_SME 2071 bool "ARM Scalable Matrix Extension support" 2072 default y 2073 depends on ARM64_SVE 2074 help 2075 The Scalable Matrix Extension (SME) is an extension to the AArch64 2076 execution state which utilises a substantial subset of the SVE 2077 instruction set, together with the addition of new architectural 2078 register state capable of holding two dimensional matrix tiles to 2079 enable various matrix operations. 2080 2081config ARM64_MODULE_PLTS 2082 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2083 depends on MODULES 2084 select HAVE_MOD_ARCH_SPECIFIC 2085 help 2086 Allocate PLTs when loading modules so that jumps and calls whose 2087 targets are too far away for their relative offsets to be encoded 2088 in the instructions themselves can be bounced via veneers in the 2089 module's PLT. This allows modules to be allocated in the generic 2090 vmalloc area after the dedicated module memory area has been 2091 exhausted. 2092 2093 When running with address space randomization (KASLR), the module 2094 region itself may be too far away for ordinary relative jumps and 2095 calls, and so in that case, module PLTs are required and cannot be 2096 disabled. 2097 2098 Specific errata workaround(s) might also force module PLTs to be 2099 enabled (ARM64_ERRATUM_843419). 2100 2101config ARM64_PSEUDO_NMI 2102 bool "Support for NMI-like interrupts" 2103 select ARM_GIC_V3 2104 help 2105 Adds support for mimicking Non-Maskable Interrupts through the use of 2106 GIC interrupt priority. This support requires version 3 or later of 2107 ARM GIC. 2108 2109 This high priority configuration for interrupts needs to be 2110 explicitly enabled by setting the kernel parameter 2111 "irqchip.gicv3_pseudo_nmi" to 1. 2112 2113 If unsure, say N 2114 2115if ARM64_PSEUDO_NMI 2116config ARM64_DEBUG_PRIORITY_MASKING 2117 bool "Debug interrupt priority masking" 2118 help 2119 This adds runtime checks to functions enabling/disabling 2120 interrupts when using priority masking. The additional checks verify 2121 the validity of ICC_PMR_EL1 when calling concerned functions. 2122 2123 If unsure, say N 2124endif # ARM64_PSEUDO_NMI 2125 2126config RELOCATABLE 2127 bool "Build a relocatable kernel image" if EXPERT 2128 select ARCH_HAS_RELR 2129 default y 2130 help 2131 This builds the kernel as a Position Independent Executable (PIE), 2132 which retains all relocation metadata required to relocate the 2133 kernel binary at runtime to a different virtual address than the 2134 address it was linked at. 2135 Since AArch64 uses the RELA relocation format, this requires a 2136 relocation pass at runtime even if the kernel is loaded at the 2137 same address it was linked at. 2138 2139config RANDOMIZE_BASE 2140 bool "Randomize the address of the kernel image" 2141 select ARM64_MODULE_PLTS if MODULES 2142 select RELOCATABLE 2143 help 2144 Randomizes the virtual address at which the kernel image is 2145 loaded, as a security feature that deters exploit attempts 2146 relying on knowledge of the location of kernel internals. 2147 2148 It is the bootloader's job to provide entropy, by passing a 2149 random u64 value in /chosen/kaslr-seed at kernel entry. 2150 2151 When booting via the UEFI stub, it will invoke the firmware's 2152 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2153 to the kernel proper. In addition, it will randomise the physical 2154 location of the kernel Image as well. 2155 2156 If unsure, say N. 2157 2158config RANDOMIZE_MODULE_REGION_FULL 2159 bool "Randomize the module region over a 2 GB range" 2160 depends on RANDOMIZE_BASE 2161 default y 2162 help 2163 Randomizes the location of the module region inside a 2 GB window 2164 covering the core kernel. This way, it is less likely for modules 2165 to leak information about the location of core kernel data structures 2166 but it does imply that function calls between modules and the core 2167 kernel will need to be resolved via veneers in the module PLT. 2168 2169 When this option is not set, the module region will be randomized over 2170 a limited range that contains the [_stext, _etext] interval of the 2171 core kernel, so branch relocations are almost always in range unless 2172 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2173 particular case of region exhaustion, modules might be able to fall 2174 back to a larger 2GB area. 2175 2176config CC_HAVE_STACKPROTECTOR_SYSREG 2177 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2178 2179config STACKPROTECTOR_PER_TASK 2180 def_bool y 2181 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2182 2183config UNWIND_PATCH_PAC_INTO_SCS 2184 bool "Enable shadow call stack dynamically using code patching" 2185 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2186 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2187 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2188 depends on SHADOW_CALL_STACK 2189 select UNWIND_TABLES 2190 select DYNAMIC_SCS 2191 2192endmenu # "Kernel Features" 2193 2194menu "Boot options" 2195 2196config ARM64_ACPI_PARKING_PROTOCOL 2197 bool "Enable support for the ARM64 ACPI parking protocol" 2198 depends on ACPI 2199 help 2200 Enable support for the ARM64 ACPI parking protocol. If disabled 2201 the kernel will not allow booting through the ARM64 ACPI parking 2202 protocol even if the corresponding data is present in the ACPI 2203 MADT table. 2204 2205config CMDLINE 2206 string "Default kernel command string" 2207 default "" 2208 help 2209 Provide a set of default command-line options at build time by 2210 entering them here. As a minimum, you should specify the the 2211 root device (e.g. root=/dev/nfs). 2212 2213choice 2214 prompt "Kernel command line type" if CMDLINE != "" 2215 default CMDLINE_FROM_BOOTLOADER 2216 help 2217 Choose how the kernel will handle the provided default kernel 2218 command line string. 2219 2220config CMDLINE_FROM_BOOTLOADER 2221 bool "Use bootloader kernel arguments if available" 2222 help 2223 Uses the command-line options passed by the boot loader. If 2224 the boot loader doesn't provide any, the default kernel command 2225 string provided in CMDLINE will be used. 2226 2227config CMDLINE_FORCE 2228 bool "Always use the default kernel command string" 2229 help 2230 Always use the default kernel command string, even if the boot 2231 loader passes other arguments to the kernel. 2232 This is useful if you cannot or don't want to change the 2233 command-line options your boot loader passes to the kernel. 2234 2235endchoice 2236 2237config EFI_STUB 2238 bool 2239 2240config EFI 2241 bool "UEFI runtime support" 2242 depends on OF && !CPU_BIG_ENDIAN 2243 depends on KERNEL_MODE_NEON 2244 select ARCH_SUPPORTS_ACPI 2245 select LIBFDT 2246 select UCS2_STRING 2247 select EFI_PARAMS_FROM_FDT 2248 select EFI_RUNTIME_WRAPPERS 2249 select EFI_STUB 2250 select EFI_GENERIC_STUB 2251 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2252 default y 2253 help 2254 This option provides support for runtime services provided 2255 by UEFI firmware (such as non-volatile variables, realtime 2256 clock, and platform reset). A UEFI stub is also provided to 2257 allow the kernel to be booted as an EFI application. This 2258 is only useful on systems that have UEFI firmware. 2259 2260config DMI 2261 bool "Enable support for SMBIOS (DMI) tables" 2262 depends on EFI 2263 default y 2264 help 2265 This enables SMBIOS/DMI feature for systems. 2266 2267 This option is only useful on systems that have UEFI firmware. 2268 However, even with this option, the resultant kernel should 2269 continue to boot on existing non-UEFI platforms. 2270 2271endmenu # "Boot options" 2272 2273menu "Power management options" 2274 2275source "kernel/power/Kconfig" 2276 2277config ARCH_HIBERNATION_POSSIBLE 2278 def_bool y 2279 depends on CPU_PM 2280 2281config ARCH_HIBERNATION_HEADER 2282 def_bool y 2283 depends on HIBERNATION 2284 2285config ARCH_SUSPEND_POSSIBLE 2286 def_bool y 2287 2288endmenu # "Power management options" 2289 2290menu "CPU Power Management" 2291 2292source "drivers/cpuidle/Kconfig" 2293 2294source "drivers/cpufreq/Kconfig" 2295 2296endmenu # "CPU Power Management" 2297 2298source "drivers/acpi/Kconfig" 2299 2300source "arch/arm64/kvm/Kconfig" 2301 2302