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