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_LD_ORPHAN_WARN 104 select ARCH_WANTS_NO_INSTR 105 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 106 select ARCH_HAS_UBSAN_SANITIZE_ALL 107 select ARM_AMBA 108 select ARM_ARCH_TIMER 109 select ARM_GIC 110 select AUDIT_ARCH_COMPAT_GENERIC 111 select ARM_GIC_V2M if PCI 112 select ARM_GIC_V3 113 select ARM_GIC_V3_ITS if PCI 114 select ARM_PSCI_FW 115 select BUILDTIME_TABLE_SORT 116 select CLONE_BACKWARDS 117 select COMMON_CLK 118 select CPU_PM if (SUSPEND || CPU_IDLE) 119 select CRC32 120 select DCACHE_WORD_ACCESS 121 select DYNAMIC_FTRACE if FUNCTION_TRACER 122 select DMA_DIRECT_REMAP 123 select EDAC_SUPPORT 124 select FRAME_POINTER 125 select FUNCTION_ALIGNMENT_4B 126 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 127 select GENERIC_ALLOCATOR 128 select GENERIC_ARCH_TOPOLOGY 129 select GENERIC_CLOCKEVENTS_BROADCAST 130 select GENERIC_CPU_AUTOPROBE 131 select GENERIC_CPU_VULNERABILITIES 132 select GENERIC_EARLY_IOREMAP 133 select GENERIC_IDLE_POLL_SETUP 134 select GENERIC_IOREMAP 135 select GENERIC_IRQ_IPI 136 select GENERIC_IRQ_PROBE 137 select GENERIC_IRQ_SHOW 138 select GENERIC_IRQ_SHOW_LEVEL 139 select GENERIC_LIB_DEVMEM_IS_ALLOWED 140 select GENERIC_PCI_IOMAP 141 select GENERIC_PTDUMP 142 select GENERIC_SCHED_CLOCK 143 select GENERIC_SMP_IDLE_THREAD 144 select GENERIC_TIME_VSYSCALL 145 select GENERIC_GETTIMEOFDAY 146 select GENERIC_VDSO_TIME_NS 147 select HARDIRQS_SW_RESEND 148 select HAVE_MOVE_PMD 149 select HAVE_MOVE_PUD 150 select HAVE_PCI 151 select HAVE_ACPI_APEI if (ACPI && EFI) 152 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 153 select HAVE_ARCH_AUDITSYSCALL 154 select HAVE_ARCH_BITREVERSE 155 select HAVE_ARCH_COMPILER_H 156 select HAVE_ARCH_HUGE_VMALLOC 157 select HAVE_ARCH_HUGE_VMAP 158 select HAVE_ARCH_JUMP_LABEL 159 select HAVE_ARCH_JUMP_LABEL_RELATIVE 160 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 161 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 162 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 163 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 164 # Some instrumentation may be unsound, hence EXPERT 165 select HAVE_ARCH_KCSAN if EXPERT 166 select HAVE_ARCH_KFENCE 167 select HAVE_ARCH_KGDB 168 select HAVE_ARCH_MMAP_RND_BITS 169 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 170 select HAVE_ARCH_PREL32_RELOCATIONS 171 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 172 select HAVE_ARCH_SECCOMP_FILTER 173 select HAVE_ARCH_STACKLEAK 174 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 175 select HAVE_ARCH_TRACEHOOK 176 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 177 select HAVE_ARCH_VMAP_STACK 178 select HAVE_ARM_SMCCC 179 select HAVE_ASM_MODVERSIONS 180 select HAVE_EBPF_JIT 181 select HAVE_C_RECORDMCOUNT 182 select HAVE_CMPXCHG_DOUBLE 183 select HAVE_CMPXCHG_LOCAL 184 select HAVE_CONTEXT_TRACKING_USER 185 select HAVE_DEBUG_KMEMLEAK 186 select HAVE_DMA_CONTIGUOUS 187 select HAVE_DYNAMIC_FTRACE 188 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 189 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 190 !CC_OPTIMIZE_FOR_SIZE) 191 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 192 if DYNAMIC_FTRACE_WITH_ARGS 193 select HAVE_EFFICIENT_UNALIGNED_ACCESS 194 select HAVE_FAST_GUP 195 select HAVE_FTRACE_MCOUNT_RECORD 196 select HAVE_FUNCTION_TRACER 197 select HAVE_FUNCTION_ERROR_INJECTION 198 select HAVE_FUNCTION_GRAPH_TRACER 199 select HAVE_GCC_PLUGINS 200 select HAVE_HW_BREAKPOINT if PERF_EVENTS 201 select HAVE_IOREMAP_PROT 202 select HAVE_IRQ_TIME_ACCOUNTING 203 select HAVE_KVM 204 select HAVE_NMI 205 select HAVE_PERF_EVENTS 206 select HAVE_PERF_REGS 207 select HAVE_PERF_USER_STACK_DUMP 208 select HAVE_PREEMPT_DYNAMIC_KEY 209 select HAVE_REGS_AND_STACK_ACCESS_API 210 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 211 select HAVE_FUNCTION_ARG_ACCESS_API 212 select MMU_GATHER_RCU_TABLE_FREE 213 select HAVE_RSEQ 214 select HAVE_STACKPROTECTOR 215 select HAVE_SYSCALL_TRACEPOINTS 216 select HAVE_KPROBES 217 select HAVE_KRETPROBES 218 select HAVE_GENERIC_VDSO 219 select IRQ_DOMAIN 220 select IRQ_FORCED_THREADING 221 select KASAN_VMALLOC if KASAN 222 select MODULES_USE_ELF_RELA 223 select NEED_DMA_MAP_STATE 224 select NEED_SG_DMA_LENGTH 225 select OF 226 select OF_EARLY_FLATTREE 227 select PCI_DOMAINS_GENERIC if PCI 228 select PCI_ECAM if (ACPI && PCI) 229 select PCI_SYSCALL if PCI 230 select POWER_RESET 231 select POWER_SUPPLY 232 select SPARSE_IRQ 233 select SWIOTLB 234 select SYSCTL_EXCEPTION_TRACE 235 select THREAD_INFO_IN_TASK 236 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 237 select TRACE_IRQFLAGS_SUPPORT 238 select TRACE_IRQFLAGS_NMI_SUPPORT 239 select HAVE_SOFTIRQ_ON_OWN_STACK 240 help 241 ARM 64-bit (AArch64) Linux support. 242 243config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 244 def_bool CC_IS_CLANG 245 # https://github.com/ClangBuiltLinux/linux/issues/1507 246 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 247 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 248 249config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 250 def_bool CC_IS_GCC 251 depends on $(cc-option,-fpatchable-function-entry=2) 252 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 253 254config 64BIT 255 def_bool y 256 257config MMU 258 def_bool y 259 260config ARM64_PAGE_SHIFT 261 int 262 default 16 if ARM64_64K_PAGES 263 default 14 if ARM64_16K_PAGES 264 default 12 265 266config ARM64_CONT_PTE_SHIFT 267 int 268 default 5 if ARM64_64K_PAGES 269 default 7 if ARM64_16K_PAGES 270 default 4 271 272config ARM64_CONT_PMD_SHIFT 273 int 274 default 5 if ARM64_64K_PAGES 275 default 5 if ARM64_16K_PAGES 276 default 4 277 278config ARCH_MMAP_RND_BITS_MIN 279 default 14 if ARM64_64K_PAGES 280 default 16 if ARM64_16K_PAGES 281 default 18 282 283# max bits determined by the following formula: 284# VA_BITS - PAGE_SHIFT - 3 285config ARCH_MMAP_RND_BITS_MAX 286 default 19 if ARM64_VA_BITS=36 287 default 24 if ARM64_VA_BITS=39 288 default 27 if ARM64_VA_BITS=42 289 default 30 if ARM64_VA_BITS=47 290 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 291 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 292 default 33 if ARM64_VA_BITS=48 293 default 14 if ARM64_64K_PAGES 294 default 16 if ARM64_16K_PAGES 295 default 18 296 297config ARCH_MMAP_RND_COMPAT_BITS_MIN 298 default 7 if ARM64_64K_PAGES 299 default 9 if ARM64_16K_PAGES 300 default 11 301 302config ARCH_MMAP_RND_COMPAT_BITS_MAX 303 default 16 304 305config NO_IOPORT_MAP 306 def_bool y if !PCI 307 308config STACKTRACE_SUPPORT 309 def_bool y 310 311config ILLEGAL_POINTER_VALUE 312 hex 313 default 0xdead000000000000 314 315config LOCKDEP_SUPPORT 316 def_bool y 317 318config GENERIC_BUG 319 def_bool y 320 depends on BUG 321 322config GENERIC_BUG_RELATIVE_POINTERS 323 def_bool y 324 depends on GENERIC_BUG 325 326config GENERIC_HWEIGHT 327 def_bool y 328 329config GENERIC_CSUM 330 def_bool y 331 332config GENERIC_CALIBRATE_DELAY 333 def_bool y 334 335config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 336 def_bool y 337 338config SMP 339 def_bool y 340 341config KERNEL_MODE_NEON 342 def_bool y 343 344config FIX_EARLYCON_MEM 345 def_bool y 346 347config PGTABLE_LEVELS 348 int 349 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 350 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 351 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 352 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 353 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 354 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 355 356config ARCH_SUPPORTS_UPROBES 357 def_bool y 358 359config ARCH_PROC_KCORE_TEXT 360 def_bool y 361 362config BROKEN_GAS_INST 363 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 364 365config KASAN_SHADOW_OFFSET 366 hex 367 depends on KASAN_GENERIC || KASAN_SW_TAGS 368 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 369 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 370 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 371 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 372 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 373 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 374 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 375 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 376 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 377 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 378 default 0xffffffffffffffff 379 380config UNWIND_TABLES 381 bool 382 383source "arch/arm64/Kconfig.platforms" 384 385menu "Kernel Features" 386 387menu "ARM errata workarounds via the alternatives framework" 388 389config ARM64_WORKAROUND_CLEAN_CACHE 390 bool 391 392config ARM64_ERRATUM_826319 393 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 394 default y 395 select ARM64_WORKAROUND_CLEAN_CACHE 396 help 397 This option adds an alternative code sequence to work around ARM 398 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 399 AXI master interface and an L2 cache. 400 401 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 402 and is unable to accept a certain write via this interface, it will 403 not progress on read data presented on the read data channel and the 404 system can deadlock. 405 406 The workaround promotes data cache clean instructions to 407 data cache clean-and-invalidate. 408 Please note that this does not necessarily enable the workaround, 409 as it depends on the alternative framework, which will only patch 410 the kernel if an affected CPU is detected. 411 412 If unsure, say Y. 413 414config ARM64_ERRATUM_827319 415 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 416 default y 417 select ARM64_WORKAROUND_CLEAN_CACHE 418 help 419 This option adds an alternative code sequence to work around ARM 420 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 421 master interface and an L2 cache. 422 423 Under certain conditions this erratum can cause a clean line eviction 424 to occur at the same time as another transaction to the same address 425 on the AMBA 5 CHI interface, which can cause data corruption if the 426 interconnect reorders the two transactions. 427 428 The workaround promotes data cache clean instructions to 429 data cache clean-and-invalidate. 430 Please note that this does not necessarily enable the workaround, 431 as it depends on the alternative framework, which will only patch 432 the kernel if an affected CPU is detected. 433 434 If unsure, say Y. 435 436config ARM64_ERRATUM_824069 437 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 438 default y 439 select ARM64_WORKAROUND_CLEAN_CACHE 440 help 441 This option adds an alternative code sequence to work around ARM 442 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 443 to a coherent interconnect. 444 445 If a Cortex-A53 processor is executing a store or prefetch for 446 write instruction at the same time as a processor in another 447 cluster is executing a cache maintenance operation to the same 448 address, then this erratum might cause a clean cache line to be 449 incorrectly marked as dirty. 450 451 The workaround promotes data cache clean instructions to 452 data cache clean-and-invalidate. 453 Please note that this option does not necessarily enable the 454 workaround, as it depends on the alternative framework, which will 455 only patch the kernel if an affected CPU is detected. 456 457 If unsure, say Y. 458 459config ARM64_ERRATUM_819472 460 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 461 default y 462 select ARM64_WORKAROUND_CLEAN_CACHE 463 help 464 This option adds an alternative code sequence to work around ARM 465 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 466 present when it is connected to a coherent interconnect. 467 468 If the processor is executing a load and store exclusive sequence at 469 the same time as a processor in another cluster is executing a cache 470 maintenance operation to the same address, then this erratum might 471 cause data corruption. 472 473 The workaround promotes data cache clean instructions to 474 data cache clean-and-invalidate. 475 Please note that this does not necessarily enable the workaround, 476 as it depends on the alternative framework, which will only patch 477 the kernel if an affected CPU is detected. 478 479 If unsure, say Y. 480 481config ARM64_ERRATUM_832075 482 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 483 default y 484 help 485 This option adds an alternative code sequence to work around ARM 486 erratum 832075 on Cortex-A57 parts up to r1p2. 487 488 Affected Cortex-A57 parts might deadlock when exclusive load/store 489 instructions to Write-Back memory are mixed with Device loads. 490 491 The workaround is to promote device loads to use Load-Acquire 492 semantics. 493 Please note that this does not necessarily enable the workaround, 494 as it depends on the alternative framework, which will only patch 495 the kernel if an affected CPU is detected. 496 497 If unsure, say Y. 498 499config ARM64_ERRATUM_834220 500 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 501 depends on KVM 502 default y 503 help 504 This option adds an alternative code sequence to work around ARM 505 erratum 834220 on Cortex-A57 parts up to r1p2. 506 507 Affected Cortex-A57 parts might report a Stage 2 translation 508 fault as the result of a Stage 1 fault for load crossing a 509 page boundary when there is a permission or device memory 510 alignment fault at Stage 1 and a translation fault at Stage 2. 511 512 The workaround is to verify that the Stage 1 translation 513 doesn't generate a fault before handling the Stage 2 fault. 514 Please note that this does not necessarily enable the workaround, 515 as it depends on the alternative framework, which will only patch 516 the kernel if an affected CPU is detected. 517 518 If unsure, say Y. 519 520config ARM64_ERRATUM_1742098 521 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 522 depends on COMPAT 523 default y 524 help 525 This option removes the AES hwcap for aarch32 user-space to 526 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 527 528 Affected parts may corrupt the AES state if an interrupt is 529 taken between a pair of AES instructions. These instructions 530 are only present if the cryptography extensions are present. 531 All software should have a fallback implementation for CPUs 532 that don't implement the cryptography extensions. 533 534 If unsure, say Y. 535 536config ARM64_ERRATUM_845719 537 bool "Cortex-A53: 845719: a load might read incorrect data" 538 depends on COMPAT 539 default y 540 help 541 This option adds an alternative code sequence to work around ARM 542 erratum 845719 on Cortex-A53 parts up to r0p4. 543 544 When running a compat (AArch32) userspace on an affected Cortex-A53 545 part, a load at EL0 from a virtual address that matches the bottom 32 546 bits of the virtual address used by a recent load at (AArch64) EL1 547 might return incorrect data. 548 549 The workaround is to write the contextidr_el1 register on exception 550 return to a 32-bit task. 551 Please note that this does not necessarily enable the workaround, 552 as it depends on the alternative framework, which will only patch 553 the kernel if an affected CPU is detected. 554 555 If unsure, say Y. 556 557config ARM64_ERRATUM_843419 558 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 559 default y 560 select ARM64_MODULE_PLTS if MODULES 561 help 562 This option links the kernel with '--fix-cortex-a53-843419' and 563 enables PLT support to replace certain ADRP instructions, which can 564 cause subsequent memory accesses to use an incorrect address on 565 Cortex-A53 parts up to r0p4. 566 567 If unsure, say Y. 568 569config ARM64_LD_HAS_FIX_ERRATUM_843419 570 def_bool $(ld-option,--fix-cortex-a53-843419) 571 572config ARM64_ERRATUM_1024718 573 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 574 default y 575 help 576 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 577 578 Affected Cortex-A55 cores (all revisions) could cause incorrect 579 update of the hardware dirty bit when the DBM/AP bits are updated 580 without a break-before-make. The workaround is to disable the usage 581 of hardware DBM locally on the affected cores. CPUs not affected by 582 this erratum will continue to use the feature. 583 584 If unsure, say Y. 585 586config ARM64_ERRATUM_1418040 587 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 588 default y 589 depends on COMPAT 590 help 591 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 592 errata 1188873 and 1418040. 593 594 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 595 cause register corruption when accessing the timer registers 596 from AArch32 userspace. 597 598 If unsure, say Y. 599 600config ARM64_WORKAROUND_SPECULATIVE_AT 601 bool 602 603config ARM64_ERRATUM_1165522 604 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 605 default y 606 select ARM64_WORKAROUND_SPECULATIVE_AT 607 help 608 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 609 610 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 611 corrupted TLBs by speculating an AT instruction during a guest 612 context switch. 613 614 If unsure, say Y. 615 616config ARM64_ERRATUM_1319367 617 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 618 default y 619 select ARM64_WORKAROUND_SPECULATIVE_AT 620 help 621 This option adds work arounds for ARM Cortex-A57 erratum 1319537 622 and A72 erratum 1319367 623 624 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 625 speculating an AT instruction during a guest context switch. 626 627 If unsure, say Y. 628 629config ARM64_ERRATUM_1530923 630 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 631 default y 632 select ARM64_WORKAROUND_SPECULATIVE_AT 633 help 634 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 635 636 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 637 corrupted TLBs by speculating an AT instruction during a guest 638 context switch. 639 640 If unsure, say Y. 641 642config ARM64_WORKAROUND_REPEAT_TLBI 643 bool 644 645config ARM64_ERRATUM_2441007 646 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 647 default y 648 select ARM64_WORKAROUND_REPEAT_TLBI 649 help 650 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 651 652 Under very rare circumstances, affected Cortex-A55 CPUs 653 may not handle a race between a break-before-make sequence on one 654 CPU, and another CPU accessing the same page. This could allow a 655 store to a page that has been unmapped. 656 657 Work around this by adding the affected CPUs to the list that needs 658 TLB sequences to be done twice. 659 660 If unsure, say Y. 661 662config ARM64_ERRATUM_1286807 663 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 664 default y 665 select ARM64_WORKAROUND_REPEAT_TLBI 666 help 667 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 668 669 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 670 address for a cacheable mapping of a location is being 671 accessed by a core while another core is remapping the virtual 672 address to a new physical page using the recommended 673 break-before-make sequence, then under very rare circumstances 674 TLBI+DSB completes before a read using the translation being 675 invalidated has been observed by other observers. The 676 workaround repeats the TLBI+DSB operation. 677 678config ARM64_ERRATUM_1463225 679 bool "Cortex-A76: Software Step might prevent interrupt recognition" 680 default y 681 help 682 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 683 684 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 685 of a system call instruction (SVC) can prevent recognition of 686 subsequent interrupts when software stepping is disabled in the 687 exception handler of the system call and either kernel debugging 688 is enabled or VHE is in use. 689 690 Work around the erratum by triggering a dummy step exception 691 when handling a system call from a task that is being stepped 692 in a VHE configuration of the kernel. 693 694 If unsure, say Y. 695 696config ARM64_ERRATUM_1542419 697 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 698 default y 699 help 700 This option adds a workaround for ARM Neoverse-N1 erratum 701 1542419. 702 703 Affected Neoverse-N1 cores could execute a stale instruction when 704 modified by another CPU. The workaround depends on a firmware 705 counterpart. 706 707 Workaround the issue by hiding the DIC feature from EL0. This 708 forces user-space to perform cache maintenance. 709 710 If unsure, say Y. 711 712config ARM64_ERRATUM_1508412 713 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 714 default y 715 help 716 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 717 718 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 719 of a store-exclusive or read of PAR_EL1 and a load with device or 720 non-cacheable memory attributes. The workaround depends on a firmware 721 counterpart. 722 723 KVM guests must also have the workaround implemented or they can 724 deadlock the system. 725 726 Work around the issue by inserting DMB SY barriers around PAR_EL1 727 register reads and warning KVM users. The DMB barrier is sufficient 728 to prevent a speculative PAR_EL1 read. 729 730 If unsure, say Y. 731 732config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 733 bool 734 735config ARM64_ERRATUM_2051678 736 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 737 default y 738 help 739 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 740 Affected Cortex-A510 might not respect the ordering rules for 741 hardware update of the page table's dirty bit. The workaround 742 is to not enable the feature on affected CPUs. 743 744 If unsure, say Y. 745 746config ARM64_ERRATUM_2077057 747 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 748 default y 749 help 750 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 751 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 752 expected, but a Pointer Authentication trap is taken instead. The 753 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 754 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 755 756 This can only happen when EL2 is stepping EL1. 757 758 When these conditions occur, the SPSR_EL2 value is unchanged from the 759 previous guest entry, and can be restored from the in-memory copy. 760 761 If unsure, say Y. 762 763config ARM64_ERRATUM_2658417 764 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 765 default y 766 help 767 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 768 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 769 BFMMLA or VMMLA instructions in rare circumstances when a pair of 770 A510 CPUs are using shared neon hardware. As the sharing is not 771 discoverable by the kernel, hide the BF16 HWCAP to indicate that 772 user-space should not be using these instructions. 773 774 If unsure, say Y. 775 776config ARM64_ERRATUM_2119858 777 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 778 default y 779 depends on CORESIGHT_TRBE 780 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 781 help 782 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 783 784 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 785 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 786 the event of a WRAP event. 787 788 Work around the issue by always making sure we move the TRBPTR_EL1 by 789 256 bytes before enabling the buffer and filling the first 256 bytes of 790 the buffer with ETM ignore packets upon disabling. 791 792 If unsure, say Y. 793 794config ARM64_ERRATUM_2139208 795 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 796 default y 797 depends on CORESIGHT_TRBE 798 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 799 help 800 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 801 802 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 803 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 804 the event of a WRAP event. 805 806 Work around the issue by always making sure we move the TRBPTR_EL1 by 807 256 bytes before enabling the buffer and filling the first 256 bytes of 808 the buffer with ETM ignore packets upon disabling. 809 810 If unsure, say Y. 811 812config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 813 bool 814 815config ARM64_ERRATUM_2054223 816 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 817 default y 818 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 819 help 820 Enable workaround for ARM Cortex-A710 erratum 2054223 821 822 Affected cores may fail to flush the trace data on a TSB instruction, when 823 the PE is in trace prohibited state. This will cause losing a few bytes 824 of the trace cached. 825 826 Workaround is to issue two TSB consecutively on affected cores. 827 828 If unsure, say Y. 829 830config ARM64_ERRATUM_2067961 831 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 832 default y 833 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 834 help 835 Enable workaround for ARM Neoverse-N2 erratum 2067961 836 837 Affected cores may fail to flush the trace data on a TSB instruction, when 838 the PE is in trace prohibited state. This will cause losing a few bytes 839 of the trace cached. 840 841 Workaround is to issue two TSB consecutively on affected cores. 842 843 If unsure, say Y. 844 845config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 846 bool 847 848config ARM64_ERRATUM_2253138 849 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 850 depends on CORESIGHT_TRBE 851 default y 852 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 853 help 854 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 855 856 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 857 for TRBE. Under some conditions, the TRBE might generate a write to the next 858 virtually addressed page following the last page of the TRBE address space 859 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 860 861 Work around this in the driver by always making sure that there is a 862 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 863 864 If unsure, say Y. 865 866config ARM64_ERRATUM_2224489 867 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 868 depends on CORESIGHT_TRBE 869 default y 870 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 871 help 872 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 873 874 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 875 for TRBE. Under some conditions, the TRBE might generate a write to the next 876 virtually addressed page following the last page of the TRBE address space 877 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 878 879 Work around this in the driver by always making sure that there is a 880 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 881 882 If unsure, say Y. 883 884config ARM64_ERRATUM_2441009 885 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 886 default y 887 select ARM64_WORKAROUND_REPEAT_TLBI 888 help 889 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 890 891 Under very rare circumstances, affected Cortex-A510 CPUs 892 may not handle a race between a break-before-make sequence on one 893 CPU, and another CPU accessing the same page. This could allow a 894 store to a page that has been unmapped. 895 896 Work around this by adding the affected CPUs to the list that needs 897 TLB sequences to be done twice. 898 899 If unsure, say Y. 900 901config ARM64_ERRATUM_2064142 902 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 903 depends on CORESIGHT_TRBE 904 default y 905 help 906 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 907 908 Affected Cortex-A510 core might fail to write into system registers after the 909 TRBE has been disabled. Under some conditions after the TRBE has been disabled 910 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 911 and TRBTRG_EL1 will be ignored and will not be effected. 912 913 Work around this in the driver by executing TSB CSYNC and DSB after collection 914 is stopped and before performing a system register write to one of the affected 915 registers. 916 917 If unsure, say Y. 918 919config ARM64_ERRATUM_2038923 920 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 921 depends on CORESIGHT_TRBE 922 default y 923 help 924 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 925 926 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 927 prohibited within the CPU. As a result, the trace buffer or trace buffer state 928 might be corrupted. This happens after TRBE buffer has been enabled by setting 929 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 930 execution changes from a context, in which trace is prohibited to one where it 931 isn't, or vice versa. In these mentioned conditions, the view of whether trace 932 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 933 the trace buffer state might be corrupted. 934 935 Work around this in the driver by preventing an inconsistent view of whether the 936 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 937 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 938 two ISB instructions if no ERET is to take place. 939 940 If unsure, say Y. 941 942config ARM64_ERRATUM_1902691 943 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 944 depends on CORESIGHT_TRBE 945 default y 946 help 947 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 948 949 Affected Cortex-A510 core might cause trace data corruption, when being written 950 into the memory. Effectively TRBE is broken and hence cannot be used to capture 951 trace data. 952 953 Work around this problem in the driver by just preventing TRBE initialization on 954 affected cpus. The firmware must have disabled the access to TRBE for the kernel 955 on such implementations. This will cover the kernel for any firmware that doesn't 956 do this already. 957 958 If unsure, say Y. 959 960config ARM64_ERRATUM_2457168 961 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 962 depends on ARM64_AMU_EXTN 963 default y 964 help 965 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 966 967 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 968 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 969 incorrectly giving a significantly higher output value. 970 971 Work around this problem by returning 0 when reading the affected counter in 972 key locations that results in disabling all users of this counter. This effect 973 is the same to firmware disabling affected counters. 974 975 If unsure, say Y. 976 977config ARM64_ERRATUM_2645198 978 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 979 default y 980 help 981 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 982 983 If a Cortex-A715 cpu sees a page mapping permissions change from executable 984 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 985 next instruction abort caused by permission fault. 986 987 Only user-space does executable to non-executable permission transition via 988 mprotect() system call. Workaround the problem by doing a break-before-make 989 TLB invalidation, for all changes to executable user space mappings. 990 991 If unsure, say Y. 992 993config CAVIUM_ERRATUM_22375 994 bool "Cavium erratum 22375, 24313" 995 default y 996 help 997 Enable workaround for errata 22375 and 24313. 998 999 This implements two gicv3-its errata workarounds for ThunderX. Both 1000 with a small impact affecting only ITS table allocation. 1001 1002 erratum 22375: only alloc 8MB table size 1003 erratum 24313: ignore memory access type 1004 1005 The fixes are in ITS initialization and basically ignore memory access 1006 type and table size provided by the TYPER and BASER registers. 1007 1008 If unsure, say Y. 1009 1010config CAVIUM_ERRATUM_23144 1011 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1012 depends on NUMA 1013 default y 1014 help 1015 ITS SYNC command hang for cross node io and collections/cpu mapping. 1016 1017 If unsure, say Y. 1018 1019config CAVIUM_ERRATUM_23154 1020 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1021 default y 1022 help 1023 The ThunderX GICv3 implementation requires a modified version for 1024 reading the IAR status to ensure data synchronization 1025 (access to icc_iar1_el1 is not sync'ed before and after). 1026 1027 It also suffers from erratum 38545 (also present on Marvell's 1028 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1029 spuriously presented to the CPU interface. 1030 1031 If unsure, say Y. 1032 1033config CAVIUM_ERRATUM_27456 1034 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1035 default y 1036 help 1037 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1038 instructions may cause the icache to become corrupted if it 1039 contains data for a non-current ASID. The fix is to 1040 invalidate the icache when changing the mm context. 1041 1042 If unsure, say Y. 1043 1044config CAVIUM_ERRATUM_30115 1045 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1046 default y 1047 help 1048 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1049 1.2, and T83 Pass 1.0, KVM guest execution may disable 1050 interrupts in host. Trapping both GICv3 group-0 and group-1 1051 accesses sidesteps the issue. 1052 1053 If unsure, say Y. 1054 1055config CAVIUM_TX2_ERRATUM_219 1056 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1057 default y 1058 help 1059 On Cavium ThunderX2, a load, store or prefetch instruction between a 1060 TTBR update and the corresponding context synchronizing operation can 1061 cause a spurious Data Abort to be delivered to any hardware thread in 1062 the CPU core. 1063 1064 Work around the issue by avoiding the problematic code sequence and 1065 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1066 trap handler performs the corresponding register access, skips the 1067 instruction and ensures context synchronization by virtue of the 1068 exception return. 1069 1070 If unsure, say Y. 1071 1072config FUJITSU_ERRATUM_010001 1073 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1074 default y 1075 help 1076 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1077 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1078 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1079 This fault occurs under a specific hardware condition when a 1080 load/store instruction performs an address translation using: 1081 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1082 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1083 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1084 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1085 1086 The workaround is to ensure these bits are clear in TCR_ELx. 1087 The workaround only affects the Fujitsu-A64FX. 1088 1089 If unsure, say Y. 1090 1091config HISILICON_ERRATUM_161600802 1092 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1093 default y 1094 help 1095 The HiSilicon Hip07 SoC uses the wrong redistributor base 1096 when issued ITS commands such as VMOVP and VMAPP, and requires 1097 a 128kB offset to be applied to the target address in this commands. 1098 1099 If unsure, say Y. 1100 1101config QCOM_FALKOR_ERRATUM_1003 1102 bool "Falkor E1003: Incorrect translation due to ASID change" 1103 default y 1104 help 1105 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1106 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1107 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1108 then only for entries in the walk cache, since the leaf translation 1109 is unchanged. Work around the erratum by invalidating the walk cache 1110 entries for the trampoline before entering the kernel proper. 1111 1112config QCOM_FALKOR_ERRATUM_1009 1113 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1114 default y 1115 select ARM64_WORKAROUND_REPEAT_TLBI 1116 help 1117 On Falkor v1, the CPU may prematurely complete a DSB following a 1118 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1119 one more time to fix the issue. 1120 1121 If unsure, say Y. 1122 1123config QCOM_QDF2400_ERRATUM_0065 1124 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1125 default y 1126 help 1127 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1128 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1129 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1130 1131 If unsure, say Y. 1132 1133config QCOM_FALKOR_ERRATUM_E1041 1134 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1135 default y 1136 help 1137 Falkor CPU may speculatively fetch instructions from an improper 1138 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1139 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1140 1141 If unsure, say Y. 1142 1143config NVIDIA_CARMEL_CNP_ERRATUM 1144 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1145 default y 1146 help 1147 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1148 invalidate shared TLB entries installed by a different core, as it would 1149 on standard ARM cores. 1150 1151 If unsure, say Y. 1152 1153config SOCIONEXT_SYNQUACER_PREITS 1154 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1155 default y 1156 help 1157 Socionext Synquacer SoCs implement a separate h/w block to generate 1158 MSI doorbell writes with non-zero values for the device ID. 1159 1160 If unsure, say Y. 1161 1162endmenu # "ARM errata workarounds via the alternatives framework" 1163 1164choice 1165 prompt "Page size" 1166 default ARM64_4K_PAGES 1167 help 1168 Page size (translation granule) configuration. 1169 1170config ARM64_4K_PAGES 1171 bool "4KB" 1172 help 1173 This feature enables 4KB pages support. 1174 1175config ARM64_16K_PAGES 1176 bool "16KB" 1177 help 1178 The system will use 16KB pages support. AArch32 emulation 1179 requires applications compiled with 16K (or a multiple of 16K) 1180 aligned segments. 1181 1182config ARM64_64K_PAGES 1183 bool "64KB" 1184 help 1185 This feature enables 64KB pages support (4KB by default) 1186 allowing only two levels of page tables and faster TLB 1187 look-up. AArch32 emulation requires applications compiled 1188 with 64K aligned segments. 1189 1190endchoice 1191 1192choice 1193 prompt "Virtual address space size" 1194 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1195 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1196 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1197 help 1198 Allows choosing one of multiple possible virtual address 1199 space sizes. The level of translation table is determined by 1200 a combination of page size and virtual address space size. 1201 1202config ARM64_VA_BITS_36 1203 bool "36-bit" if EXPERT 1204 depends on ARM64_16K_PAGES 1205 1206config ARM64_VA_BITS_39 1207 bool "39-bit" 1208 depends on ARM64_4K_PAGES 1209 1210config ARM64_VA_BITS_42 1211 bool "42-bit" 1212 depends on ARM64_64K_PAGES 1213 1214config ARM64_VA_BITS_47 1215 bool "47-bit" 1216 depends on ARM64_16K_PAGES 1217 1218config ARM64_VA_BITS_48 1219 bool "48-bit" 1220 1221config ARM64_VA_BITS_52 1222 bool "52-bit" 1223 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1224 help 1225 Enable 52-bit virtual addressing for userspace when explicitly 1226 requested via a hint to mmap(). The kernel will also use 52-bit 1227 virtual addresses for its own mappings (provided HW support for 1228 this feature is available, otherwise it reverts to 48-bit). 1229 1230 NOTE: Enabling 52-bit virtual addressing in conjunction with 1231 ARMv8.3 Pointer Authentication will result in the PAC being 1232 reduced from 7 bits to 3 bits, which may have a significant 1233 impact on its susceptibility to brute-force attacks. 1234 1235 If unsure, select 48-bit virtual addressing instead. 1236 1237endchoice 1238 1239config ARM64_FORCE_52BIT 1240 bool "Force 52-bit virtual addresses for userspace" 1241 depends on ARM64_VA_BITS_52 && EXPERT 1242 help 1243 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1244 to maintain compatibility with older software by providing 48-bit VAs 1245 unless a hint is supplied to mmap. 1246 1247 This configuration option disables the 48-bit compatibility logic, and 1248 forces all userspace addresses to be 52-bit on HW that supports it. One 1249 should only enable this configuration option for stress testing userspace 1250 memory management code. If unsure say N here. 1251 1252config ARM64_VA_BITS 1253 int 1254 default 36 if ARM64_VA_BITS_36 1255 default 39 if ARM64_VA_BITS_39 1256 default 42 if ARM64_VA_BITS_42 1257 default 47 if ARM64_VA_BITS_47 1258 default 48 if ARM64_VA_BITS_48 1259 default 52 if ARM64_VA_BITS_52 1260 1261choice 1262 prompt "Physical address space size" 1263 default ARM64_PA_BITS_48 1264 help 1265 Choose the maximum physical address range that the kernel will 1266 support. 1267 1268config ARM64_PA_BITS_48 1269 bool "48-bit" 1270 1271config ARM64_PA_BITS_52 1272 bool "52-bit (ARMv8.2)" 1273 depends on ARM64_64K_PAGES 1274 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1275 help 1276 Enable support for a 52-bit physical address space, introduced as 1277 part of the ARMv8.2-LPA extension. 1278 1279 With this enabled, the kernel will also continue to work on CPUs that 1280 do not support ARMv8.2-LPA, but with some added memory overhead (and 1281 minor performance overhead). 1282 1283endchoice 1284 1285config ARM64_PA_BITS 1286 int 1287 default 48 if ARM64_PA_BITS_48 1288 default 52 if ARM64_PA_BITS_52 1289 1290choice 1291 prompt "Endianness" 1292 default CPU_LITTLE_ENDIAN 1293 help 1294 Select the endianness of data accesses performed by the CPU. Userspace 1295 applications will need to be compiled and linked for the endianness 1296 that is selected here. 1297 1298config CPU_BIG_ENDIAN 1299 bool "Build big-endian kernel" 1300 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1301 help 1302 Say Y if you plan on running a kernel with a big-endian userspace. 1303 1304config CPU_LITTLE_ENDIAN 1305 bool "Build little-endian kernel" 1306 help 1307 Say Y if you plan on running a kernel with a little-endian userspace. 1308 This is usually the case for distributions targeting arm64. 1309 1310endchoice 1311 1312config SCHED_MC 1313 bool "Multi-core scheduler support" 1314 help 1315 Multi-core scheduler support improves the CPU scheduler's decision 1316 making when dealing with multi-core CPU chips at a cost of slightly 1317 increased overhead in some places. If unsure say N here. 1318 1319config SCHED_CLUSTER 1320 bool "Cluster scheduler support" 1321 help 1322 Cluster scheduler support improves the CPU scheduler's decision 1323 making when dealing with machines that have clusters of CPUs. 1324 Cluster usually means a couple of CPUs which are placed closely 1325 by sharing mid-level caches, last-level cache tags or internal 1326 busses. 1327 1328config SCHED_SMT 1329 bool "SMT scheduler support" 1330 help 1331 Improves the CPU scheduler's decision making when dealing with 1332 MultiThreading at a cost of slightly increased overhead in some 1333 places. If unsure say N here. 1334 1335config NR_CPUS 1336 int "Maximum number of CPUs (2-4096)" 1337 range 2 4096 1338 default "256" 1339 1340config HOTPLUG_CPU 1341 bool "Support for hot-pluggable CPUs" 1342 select GENERIC_IRQ_MIGRATION 1343 help 1344 Say Y here to experiment with turning CPUs off and on. CPUs 1345 can be controlled through /sys/devices/system/cpu. 1346 1347# Common NUMA Features 1348config NUMA 1349 bool "NUMA Memory Allocation and Scheduler Support" 1350 select GENERIC_ARCH_NUMA 1351 select ACPI_NUMA if ACPI 1352 select OF_NUMA 1353 select HAVE_SETUP_PER_CPU_AREA 1354 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1355 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1356 select USE_PERCPU_NUMA_NODE_ID 1357 help 1358 Enable NUMA (Non-Uniform Memory Access) support. 1359 1360 The kernel will try to allocate memory used by a CPU on the 1361 local memory of the CPU and add some more 1362 NUMA awareness to the kernel. 1363 1364config NODES_SHIFT 1365 int "Maximum NUMA Nodes (as a power of 2)" 1366 range 1 10 1367 default "4" 1368 depends on NUMA 1369 help 1370 Specify the maximum number of NUMA Nodes available on the target 1371 system. Increases memory reserved to accommodate various tables. 1372 1373source "kernel/Kconfig.hz" 1374 1375config ARCH_SPARSEMEM_ENABLE 1376 def_bool y 1377 select SPARSEMEM_VMEMMAP_ENABLE 1378 select SPARSEMEM_VMEMMAP 1379 1380config HW_PERF_EVENTS 1381 def_bool y 1382 depends on ARM_PMU 1383 1384# Supported by clang >= 7.0 or GCC >= 12.0.0 1385config CC_HAVE_SHADOW_CALL_STACK 1386 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1387 1388config PARAVIRT 1389 bool "Enable paravirtualization code" 1390 help 1391 This changes the kernel so it can modify itself when it is run 1392 under a hypervisor, potentially improving performance significantly 1393 over full virtualization. 1394 1395config PARAVIRT_TIME_ACCOUNTING 1396 bool "Paravirtual steal time accounting" 1397 select PARAVIRT 1398 help 1399 Select this option to enable fine granularity task steal time 1400 accounting. Time spent executing other tasks in parallel with 1401 the current vCPU is discounted from the vCPU power. To account for 1402 that, there can be a small performance impact. 1403 1404 If in doubt, say N here. 1405 1406config KEXEC 1407 depends on PM_SLEEP_SMP 1408 select KEXEC_CORE 1409 bool "kexec system call" 1410 help 1411 kexec is a system call that implements the ability to shutdown your 1412 current kernel, and to start another kernel. It is like a reboot 1413 but it is independent of the system firmware. And like a reboot 1414 you can start any kernel with it, not just Linux. 1415 1416config KEXEC_FILE 1417 bool "kexec file based system call" 1418 select KEXEC_CORE 1419 select HAVE_IMA_KEXEC if IMA 1420 help 1421 This is new version of kexec system call. This system call is 1422 file based and takes file descriptors as system call argument 1423 for kernel and initramfs as opposed to list of segments as 1424 accepted by previous system call. 1425 1426config KEXEC_SIG 1427 bool "Verify kernel signature during kexec_file_load() syscall" 1428 depends on KEXEC_FILE 1429 help 1430 Select this option to verify a signature with loaded kernel 1431 image. If configured, any attempt of loading a image without 1432 valid signature will fail. 1433 1434 In addition to that option, you need to enable signature 1435 verification for the corresponding kernel image type being 1436 loaded in order for this to work. 1437 1438config KEXEC_IMAGE_VERIFY_SIG 1439 bool "Enable Image signature verification support" 1440 default y 1441 depends on KEXEC_SIG 1442 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1443 help 1444 Enable Image signature verification support. 1445 1446comment "Support for PE file signature verification disabled" 1447 depends on KEXEC_SIG 1448 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1449 1450config CRASH_DUMP 1451 bool "Build kdump crash kernel" 1452 help 1453 Generate crash dump after being started by kexec. This should 1454 be normally only set in special crash dump kernels which are 1455 loaded in the main kernel with kexec-tools into a specially 1456 reserved region and then later executed after a crash by 1457 kdump/kexec. 1458 1459 For more details see Documentation/admin-guide/kdump/kdump.rst 1460 1461config TRANS_TABLE 1462 def_bool y 1463 depends on HIBERNATION || KEXEC_CORE 1464 1465config XEN_DOM0 1466 def_bool y 1467 depends on XEN 1468 1469config XEN 1470 bool "Xen guest support on ARM64" 1471 depends on ARM64 && OF 1472 select SWIOTLB_XEN 1473 select PARAVIRT 1474 help 1475 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1476 1477# include/linux/mmzone.h requires the following to be true: 1478# 1479# MAX_ORDER - 1 + PAGE_SHIFT <= SECTION_SIZE_BITS 1480# 1481# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS + 1 - PAGE_SHIFT: 1482# 1483# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1484# ----+-------------------+--------------+-----------------+--------------------+ 1485# 4K | 27 | 12 | 16 | 11 | 1486# 16K | 27 | 14 | 14 | 12 | 1487# 64K | 29 | 16 | 14 | 14 | 1488config ARCH_FORCE_MAX_ORDER 1489 int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES 1490 default "14" if ARM64_64K_PAGES 1491 range 12 14 if ARM64_16K_PAGES 1492 default "12" if ARM64_16K_PAGES 1493 range 11 16 if ARM64_4K_PAGES 1494 default "11" 1495 help 1496 The kernel memory allocator divides physically contiguous memory 1497 blocks into "zones", where each zone is a power of two number of 1498 pages. This option selects the largest power of two that the kernel 1499 keeps in the memory allocator. If you need to allocate very large 1500 blocks of physically contiguous memory, then you may need to 1501 increase this value. 1502 1503 This config option is actually maximum order plus one. For example, 1504 a value of 11 means that the largest free memory block is 2^10 pages. 1505 1506 We make sure that we can allocate up to a HugePage size for each configuration. 1507 Hence we have : 1508 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1509 1510 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1511 4M allocations matching the default size used by generic code. 1512 1513config UNMAP_KERNEL_AT_EL0 1514 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1515 default y 1516 help 1517 Speculation attacks against some high-performance processors can 1518 be used to bypass MMU permission checks and leak kernel data to 1519 userspace. This can be defended against by unmapping the kernel 1520 when running in userspace, mapping it back in on exception entry 1521 via a trampoline page in the vector table. 1522 1523 If unsure, say Y. 1524 1525config MITIGATE_SPECTRE_BRANCH_HISTORY 1526 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1527 default y 1528 help 1529 Speculation attacks against some high-performance processors can 1530 make use of branch history to influence future speculation. 1531 When taking an exception from user-space, a sequence of branches 1532 or a firmware call overwrites the branch history. 1533 1534config RODATA_FULL_DEFAULT_ENABLED 1535 bool "Apply r/o permissions of VM areas also to their linear aliases" 1536 default y 1537 help 1538 Apply read-only attributes of VM areas to the linear alias of 1539 the backing pages as well. This prevents code or read-only data 1540 from being modified (inadvertently or intentionally) via another 1541 mapping of the same memory page. This additional enhancement can 1542 be turned off at runtime by passing rodata=[off|on] (and turned on 1543 with rodata=full if this option is set to 'n') 1544 1545 This requires the linear region to be mapped down to pages, 1546 which may adversely affect performance in some cases. 1547 1548config ARM64_SW_TTBR0_PAN 1549 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1550 help 1551 Enabling this option prevents the kernel from accessing 1552 user-space memory directly by pointing TTBR0_EL1 to a reserved 1553 zeroed area and reserved ASID. The user access routines 1554 restore the valid TTBR0_EL1 temporarily. 1555 1556config ARM64_TAGGED_ADDR_ABI 1557 bool "Enable the tagged user addresses syscall ABI" 1558 default y 1559 help 1560 When this option is enabled, user applications can opt in to a 1561 relaxed ABI via prctl() allowing tagged addresses to be passed 1562 to system calls as pointer arguments. For details, see 1563 Documentation/arm64/tagged-address-abi.rst. 1564 1565menuconfig COMPAT 1566 bool "Kernel support for 32-bit EL0" 1567 depends on ARM64_4K_PAGES || EXPERT 1568 select HAVE_UID16 1569 select OLD_SIGSUSPEND3 1570 select COMPAT_OLD_SIGACTION 1571 help 1572 This option enables support for a 32-bit EL0 running under a 64-bit 1573 kernel at EL1. AArch32-specific components such as system calls, 1574 the user helper functions, VFP support and the ptrace interface are 1575 handled appropriately by the kernel. 1576 1577 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1578 that you will only be able to execute AArch32 binaries that were compiled 1579 with page size aligned segments. 1580 1581 If you want to execute 32-bit userspace applications, say Y. 1582 1583if COMPAT 1584 1585config KUSER_HELPERS 1586 bool "Enable kuser helpers page for 32-bit applications" 1587 default y 1588 help 1589 Warning: disabling this option may break 32-bit user programs. 1590 1591 Provide kuser helpers to compat tasks. The kernel provides 1592 helper code to userspace in read only form at a fixed location 1593 to allow userspace to be independent of the CPU type fitted to 1594 the system. This permits binaries to be run on ARMv4 through 1595 to ARMv8 without modification. 1596 1597 See Documentation/arm/kernel_user_helpers.rst for details. 1598 1599 However, the fixed address nature of these helpers can be used 1600 by ROP (return orientated programming) authors when creating 1601 exploits. 1602 1603 If all of the binaries and libraries which run on your platform 1604 are built specifically for your platform, and make no use of 1605 these helpers, then you can turn this option off to hinder 1606 such exploits. However, in that case, if a binary or library 1607 relying on those helpers is run, it will not function correctly. 1608 1609 Say N here only if you are absolutely certain that you do not 1610 need these helpers; otherwise, the safe option is to say Y. 1611 1612config COMPAT_VDSO 1613 bool "Enable vDSO for 32-bit applications" 1614 depends on !CPU_BIG_ENDIAN 1615 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1616 select GENERIC_COMPAT_VDSO 1617 default y 1618 help 1619 Place in the process address space of 32-bit applications an 1620 ELF shared object providing fast implementations of gettimeofday 1621 and clock_gettime. 1622 1623 You must have a 32-bit build of glibc 2.22 or later for programs 1624 to seamlessly take advantage of this. 1625 1626config THUMB2_COMPAT_VDSO 1627 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1628 depends on COMPAT_VDSO 1629 default y 1630 help 1631 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1632 otherwise with '-marm'. 1633 1634config COMPAT_ALIGNMENT_FIXUPS 1635 bool "Fix up misaligned multi-word loads and stores in user space" 1636 1637menuconfig ARMV8_DEPRECATED 1638 bool "Emulate deprecated/obsolete ARMv8 instructions" 1639 depends on SYSCTL 1640 help 1641 Legacy software support may require certain instructions 1642 that have been deprecated or obsoleted in the architecture. 1643 1644 Enable this config to enable selective emulation of these 1645 features. 1646 1647 If unsure, say Y 1648 1649if ARMV8_DEPRECATED 1650 1651config SWP_EMULATION 1652 bool "Emulate SWP/SWPB instructions" 1653 help 1654 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1655 they are always undefined. Say Y here to enable software 1656 emulation of these instructions for userspace using LDXR/STXR. 1657 This feature can be controlled at runtime with the abi.swp 1658 sysctl which is disabled by default. 1659 1660 In some older versions of glibc [<=2.8] SWP is used during futex 1661 trylock() operations with the assumption that the code will not 1662 be preempted. This invalid assumption may be more likely to fail 1663 with SWP emulation enabled, leading to deadlock of the user 1664 application. 1665 1666 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1667 on an external transaction monitoring block called a global 1668 monitor to maintain update atomicity. If your system does not 1669 implement a global monitor, this option can cause programs that 1670 perform SWP operations to uncached memory to deadlock. 1671 1672 If unsure, say Y 1673 1674config CP15_BARRIER_EMULATION 1675 bool "Emulate CP15 Barrier instructions" 1676 help 1677 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1678 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1679 strongly recommended to use the ISB, DSB, and DMB 1680 instructions instead. 1681 1682 Say Y here to enable software emulation of these 1683 instructions for AArch32 userspace code. When this option is 1684 enabled, CP15 barrier usage is traced which can help 1685 identify software that needs updating. This feature can be 1686 controlled at runtime with the abi.cp15_barrier sysctl. 1687 1688 If unsure, say Y 1689 1690config SETEND_EMULATION 1691 bool "Emulate SETEND instruction" 1692 help 1693 The SETEND instruction alters the data-endianness of the 1694 AArch32 EL0, and is deprecated in ARMv8. 1695 1696 Say Y here to enable software emulation of the instruction 1697 for AArch32 userspace code. This feature can be controlled 1698 at runtime with the abi.setend sysctl. 1699 1700 Note: All the cpus on the system must have mixed endian support at EL0 1701 for this feature to be enabled. If a new CPU - which doesn't support mixed 1702 endian - is hotplugged in after this feature has been enabled, there could 1703 be unexpected results in the applications. 1704 1705 If unsure, say Y 1706endif # ARMV8_DEPRECATED 1707 1708endif # COMPAT 1709 1710menu "ARMv8.1 architectural features" 1711 1712config ARM64_HW_AFDBM 1713 bool "Support for hardware updates of the Access and Dirty page flags" 1714 default y 1715 help 1716 The ARMv8.1 architecture extensions introduce support for 1717 hardware updates of the access and dirty information in page 1718 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1719 capable processors, accesses to pages with PTE_AF cleared will 1720 set this bit instead of raising an access flag fault. 1721 Similarly, writes to read-only pages with the DBM bit set will 1722 clear the read-only bit (AP[2]) instead of raising a 1723 permission fault. 1724 1725 Kernels built with this configuration option enabled continue 1726 to work on pre-ARMv8.1 hardware and the performance impact is 1727 minimal. If unsure, say Y. 1728 1729config ARM64_PAN 1730 bool "Enable support for Privileged Access Never (PAN)" 1731 default y 1732 help 1733 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1734 prevents the kernel or hypervisor from accessing user-space (EL0) 1735 memory directly. 1736 1737 Choosing this option will cause any unprotected (not using 1738 copy_to_user et al) memory access to fail with a permission fault. 1739 1740 The feature is detected at runtime, and will remain as a 'nop' 1741 instruction if the cpu does not implement the feature. 1742 1743config AS_HAS_LDAPR 1744 def_bool $(as-instr,.arch_extension rcpc) 1745 1746config AS_HAS_LSE_ATOMICS 1747 def_bool $(as-instr,.arch_extension lse) 1748 1749config ARM64_LSE_ATOMICS 1750 bool 1751 default ARM64_USE_LSE_ATOMICS 1752 depends on AS_HAS_LSE_ATOMICS 1753 1754config ARM64_USE_LSE_ATOMICS 1755 bool "Atomic instructions" 1756 default y 1757 help 1758 As part of the Large System Extensions, ARMv8.1 introduces new 1759 atomic instructions that are designed specifically to scale in 1760 very large systems. 1761 1762 Say Y here to make use of these instructions for the in-kernel 1763 atomic routines. This incurs a small overhead on CPUs that do 1764 not support these instructions and requires the kernel to be 1765 built with binutils >= 2.25 in order for the new instructions 1766 to be used. 1767 1768endmenu # "ARMv8.1 architectural features" 1769 1770menu "ARMv8.2 architectural features" 1771 1772config AS_HAS_ARMV8_2 1773 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1774 1775config AS_HAS_SHA3 1776 def_bool $(as-instr,.arch armv8.2-a+sha3) 1777 1778config ARM64_PMEM 1779 bool "Enable support for persistent memory" 1780 select ARCH_HAS_PMEM_API 1781 select ARCH_HAS_UACCESS_FLUSHCACHE 1782 help 1783 Say Y to enable support for the persistent memory API based on the 1784 ARMv8.2 DCPoP feature. 1785 1786 The feature is detected at runtime, and the kernel will use DC CVAC 1787 operations if DC CVAP is not supported (following the behaviour of 1788 DC CVAP itself if the system does not define a point of persistence). 1789 1790config ARM64_RAS_EXTN 1791 bool "Enable support for RAS CPU Extensions" 1792 default y 1793 help 1794 CPUs that support the Reliability, Availability and Serviceability 1795 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1796 errors, classify them and report them to software. 1797 1798 On CPUs with these extensions system software can use additional 1799 barriers to determine if faults are pending and read the 1800 classification from a new set of registers. 1801 1802 Selecting this feature will allow the kernel to use these barriers 1803 and access the new registers if the system supports the extension. 1804 Platform RAS features may additionally depend on firmware support. 1805 1806config ARM64_CNP 1807 bool "Enable support for Common Not Private (CNP) translations" 1808 default y 1809 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1810 help 1811 Common Not Private (CNP) allows translation table entries to 1812 be shared between different PEs in the same inner shareable 1813 domain, so the hardware can use this fact to optimise the 1814 caching of such entries in the TLB. 1815 1816 Selecting this option allows the CNP feature to be detected 1817 at runtime, and does not affect PEs that do not implement 1818 this feature. 1819 1820endmenu # "ARMv8.2 architectural features" 1821 1822menu "ARMv8.3 architectural features" 1823 1824config ARM64_PTR_AUTH 1825 bool "Enable support for pointer authentication" 1826 default y 1827 help 1828 Pointer authentication (part of the ARMv8.3 Extensions) provides 1829 instructions for signing and authenticating pointers against secret 1830 keys, which can be used to mitigate Return Oriented Programming (ROP) 1831 and other attacks. 1832 1833 This option enables these instructions at EL0 (i.e. for userspace). 1834 Choosing this option will cause the kernel to initialise secret keys 1835 for each process at exec() time, with these keys being 1836 context-switched along with the process. 1837 1838 The feature is detected at runtime. If the feature is not present in 1839 hardware it will not be advertised to userspace/KVM guest nor will it 1840 be enabled. 1841 1842 If the feature is present on the boot CPU but not on a late CPU, then 1843 the late CPU will be parked. Also, if the boot CPU does not have 1844 address auth and the late CPU has then the late CPU will still boot 1845 but with the feature disabled. On such a system, this option should 1846 not be selected. 1847 1848config ARM64_PTR_AUTH_KERNEL 1849 bool "Use pointer authentication for kernel" 1850 default y 1851 depends on ARM64_PTR_AUTH 1852 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1853 # Modern compilers insert a .note.gnu.property section note for PAC 1854 # which is only understood by binutils starting with version 2.33.1. 1855 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1856 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1857 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1858 help 1859 If the compiler supports the -mbranch-protection or 1860 -msign-return-address flag (e.g. GCC 7 or later), then this option 1861 will cause the kernel itself to be compiled with return address 1862 protection. In this case, and if the target hardware is known to 1863 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1864 disabled with minimal loss of protection. 1865 1866 This feature works with FUNCTION_GRAPH_TRACER option only if 1867 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1868 1869config CC_HAS_BRANCH_PROT_PAC_RET 1870 # GCC 9 or later, clang 8 or later 1871 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1872 1873config CC_HAS_SIGN_RETURN_ADDRESS 1874 # GCC 7, 8 1875 def_bool $(cc-option,-msign-return-address=all) 1876 1877config AS_HAS_ARMV8_3 1878 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1879 1880config AS_HAS_CFI_NEGATE_RA_STATE 1881 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1882 1883endmenu # "ARMv8.3 architectural features" 1884 1885menu "ARMv8.4 architectural features" 1886 1887config ARM64_AMU_EXTN 1888 bool "Enable support for the Activity Monitors Unit CPU extension" 1889 default y 1890 help 1891 The activity monitors extension is an optional extension introduced 1892 by the ARMv8.4 CPU architecture. This enables support for version 1 1893 of the activity monitors architecture, AMUv1. 1894 1895 To enable the use of this extension on CPUs that implement it, say Y. 1896 1897 Note that for architectural reasons, firmware _must_ implement AMU 1898 support when running on CPUs that present the activity monitors 1899 extension. The required support is present in: 1900 * Version 1.5 and later of the ARM Trusted Firmware 1901 1902 For kernels that have this configuration enabled but boot with broken 1903 firmware, you may need to say N here until the firmware is fixed. 1904 Otherwise you may experience firmware panics or lockups when 1905 accessing the counter registers. Even if you are not observing these 1906 symptoms, the values returned by the register reads might not 1907 correctly reflect reality. Most commonly, the value read will be 0, 1908 indicating that the counter is not enabled. 1909 1910config AS_HAS_ARMV8_4 1911 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1912 1913config ARM64_TLB_RANGE 1914 bool "Enable support for tlbi range feature" 1915 default y 1916 depends on AS_HAS_ARMV8_4 1917 help 1918 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1919 range of input addresses. 1920 1921 The feature introduces new assembly instructions, and they were 1922 support when binutils >= 2.30. 1923 1924endmenu # "ARMv8.4 architectural features" 1925 1926menu "ARMv8.5 architectural features" 1927 1928config AS_HAS_ARMV8_5 1929 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1930 1931config ARM64_BTI 1932 bool "Branch Target Identification support" 1933 default y 1934 help 1935 Branch Target Identification (part of the ARMv8.5 Extensions) 1936 provides a mechanism to limit the set of locations to which computed 1937 branch instructions such as BR or BLR can jump. 1938 1939 To make use of BTI on CPUs that support it, say Y. 1940 1941 BTI is intended to provide complementary protection to other control 1942 flow integrity protection mechanisms, such as the Pointer 1943 authentication mechanism provided as part of the ARMv8.3 Extensions. 1944 For this reason, it does not make sense to enable this option without 1945 also enabling support for pointer authentication. Thus, when 1946 enabling this option you should also select ARM64_PTR_AUTH=y. 1947 1948 Userspace binaries must also be specifically compiled to make use of 1949 this mechanism. If you say N here or the hardware does not support 1950 BTI, such binaries can still run, but you get no additional 1951 enforcement of branch destinations. 1952 1953config ARM64_BTI_KERNEL 1954 bool "Use Branch Target Identification for kernel" 1955 default y 1956 depends on ARM64_BTI 1957 depends on ARM64_PTR_AUTH_KERNEL 1958 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1959 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1960 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1961 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1962 depends on !CC_IS_GCC 1963 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1964 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1965 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1966 help 1967 Build the kernel with Branch Target Identification annotations 1968 and enable enforcement of this for kernel code. When this option 1969 is enabled and the system supports BTI all kernel code including 1970 modular code must have BTI enabled. 1971 1972config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1973 # GCC 9 or later, clang 8 or later 1974 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1975 1976config ARM64_E0PD 1977 bool "Enable support for E0PD" 1978 default y 1979 help 1980 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1981 that EL0 accesses made via TTBR1 always fault in constant time, 1982 providing similar benefits to KASLR as those provided by KPTI, but 1983 with lower overhead and without disrupting legitimate access to 1984 kernel memory such as SPE. 1985 1986 This option enables E0PD for TTBR1 where available. 1987 1988config ARM64_AS_HAS_MTE 1989 # Initial support for MTE went in binutils 2.32.0, checked with 1990 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1991 # as a late addition to the final architecture spec (LDGM/STGM) 1992 # is only supported in the newer 2.32.x and 2.33 binutils 1993 # versions, hence the extra "stgm" instruction check below. 1994 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1995 1996config ARM64_MTE 1997 bool "Memory Tagging Extension support" 1998 default y 1999 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2000 depends on AS_HAS_ARMV8_5 2001 depends on AS_HAS_LSE_ATOMICS 2002 # Required for tag checking in the uaccess routines 2003 depends on ARM64_PAN 2004 select ARCH_HAS_SUBPAGE_FAULTS 2005 select ARCH_USES_HIGH_VMA_FLAGS 2006 select ARCH_USES_PG_ARCH_X 2007 help 2008 Memory Tagging (part of the ARMv8.5 Extensions) provides 2009 architectural support for run-time, always-on detection of 2010 various classes of memory error to aid with software debugging 2011 to eliminate vulnerabilities arising from memory-unsafe 2012 languages. 2013 2014 This option enables the support for the Memory Tagging 2015 Extension at EL0 (i.e. for userspace). 2016 2017 Selecting this option allows the feature to be detected at 2018 runtime. Any secondary CPU not implementing this feature will 2019 not be allowed a late bring-up. 2020 2021 Userspace binaries that want to use this feature must 2022 explicitly opt in. The mechanism for the userspace is 2023 described in: 2024 2025 Documentation/arm64/memory-tagging-extension.rst. 2026 2027endmenu # "ARMv8.5 architectural features" 2028 2029menu "ARMv8.7 architectural features" 2030 2031config ARM64_EPAN 2032 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2033 default y 2034 depends on ARM64_PAN 2035 help 2036 Enhanced Privileged Access Never (EPAN) allows Privileged 2037 Access Never to be used with Execute-only mappings. 2038 2039 The feature is detected at runtime, and will remain disabled 2040 if the cpu does not implement the feature. 2041endmenu # "ARMv8.7 architectural features" 2042 2043config ARM64_SVE 2044 bool "ARM Scalable Vector Extension support" 2045 default y 2046 help 2047 The Scalable Vector Extension (SVE) is an extension to the AArch64 2048 execution state which complements and extends the SIMD functionality 2049 of the base architecture to support much larger vectors and to enable 2050 additional vectorisation opportunities. 2051 2052 To enable use of this extension on CPUs that implement it, say Y. 2053 2054 On CPUs that support the SVE2 extensions, this option will enable 2055 those too. 2056 2057 Note that for architectural reasons, firmware _must_ implement SVE 2058 support when running on SVE capable hardware. The required support 2059 is present in: 2060 2061 * version 1.5 and later of the ARM Trusted Firmware 2062 * the AArch64 boot wrapper since commit 5e1261e08abf 2063 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2064 2065 For other firmware implementations, consult the firmware documentation 2066 or vendor. 2067 2068 If you need the kernel to boot on SVE-capable hardware with broken 2069 firmware, you may need to say N here until you get your firmware 2070 fixed. Otherwise, you may experience firmware panics or lockups when 2071 booting the kernel. If unsure and you are not observing these 2072 symptoms, you should assume that it is safe to say Y. 2073 2074config ARM64_SME 2075 bool "ARM Scalable Matrix Extension support" 2076 default y 2077 depends on ARM64_SVE 2078 help 2079 The Scalable Matrix Extension (SME) is an extension to the AArch64 2080 execution state which utilises a substantial subset of the SVE 2081 instruction set, together with the addition of new architectural 2082 register state capable of holding two dimensional matrix tiles to 2083 enable various matrix operations. 2084 2085config ARM64_MODULE_PLTS 2086 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2087 depends on MODULES 2088 select HAVE_MOD_ARCH_SPECIFIC 2089 help 2090 Allocate PLTs when loading modules so that jumps and calls whose 2091 targets are too far away for their relative offsets to be encoded 2092 in the instructions themselves can be bounced via veneers in the 2093 module's PLT. This allows modules to be allocated in the generic 2094 vmalloc area after the dedicated module memory area has been 2095 exhausted. 2096 2097 When running with address space randomization (KASLR), the module 2098 region itself may be too far away for ordinary relative jumps and 2099 calls, and so in that case, module PLTs are required and cannot be 2100 disabled. 2101 2102 Specific errata workaround(s) might also force module PLTs to be 2103 enabled (ARM64_ERRATUM_843419). 2104 2105config ARM64_PSEUDO_NMI 2106 bool "Support for NMI-like interrupts" 2107 select ARM_GIC_V3 2108 help 2109 Adds support for mimicking Non-Maskable Interrupts through the use of 2110 GIC interrupt priority. This support requires version 3 or later of 2111 ARM GIC. 2112 2113 This high priority configuration for interrupts needs to be 2114 explicitly enabled by setting the kernel parameter 2115 "irqchip.gicv3_pseudo_nmi" to 1. 2116 2117 If unsure, say N 2118 2119if ARM64_PSEUDO_NMI 2120config ARM64_DEBUG_PRIORITY_MASKING 2121 bool "Debug interrupt priority masking" 2122 help 2123 This adds runtime checks to functions enabling/disabling 2124 interrupts when using priority masking. The additional checks verify 2125 the validity of ICC_PMR_EL1 when calling concerned functions. 2126 2127 If unsure, say N 2128endif # ARM64_PSEUDO_NMI 2129 2130config RELOCATABLE 2131 bool "Build a relocatable kernel image" if EXPERT 2132 select ARCH_HAS_RELR 2133 default y 2134 help 2135 This builds the kernel as a Position Independent Executable (PIE), 2136 which retains all relocation metadata required to relocate the 2137 kernel binary at runtime to a different virtual address than the 2138 address it was linked at. 2139 Since AArch64 uses the RELA relocation format, this requires a 2140 relocation pass at runtime even if the kernel is loaded at the 2141 same address it was linked at. 2142 2143config RANDOMIZE_BASE 2144 bool "Randomize the address of the kernel image" 2145 select ARM64_MODULE_PLTS if MODULES 2146 select RELOCATABLE 2147 help 2148 Randomizes the virtual address at which the kernel image is 2149 loaded, as a security feature that deters exploit attempts 2150 relying on knowledge of the location of kernel internals. 2151 2152 It is the bootloader's job to provide entropy, by passing a 2153 random u64 value in /chosen/kaslr-seed at kernel entry. 2154 2155 When booting via the UEFI stub, it will invoke the firmware's 2156 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2157 to the kernel proper. In addition, it will randomise the physical 2158 location of the kernel Image as well. 2159 2160 If unsure, say N. 2161 2162config RANDOMIZE_MODULE_REGION_FULL 2163 bool "Randomize the module region over a 2 GB range" 2164 depends on RANDOMIZE_BASE 2165 default y 2166 help 2167 Randomizes the location of the module region inside a 2 GB window 2168 covering the core kernel. This way, it is less likely for modules 2169 to leak information about the location of core kernel data structures 2170 but it does imply that function calls between modules and the core 2171 kernel will need to be resolved via veneers in the module PLT. 2172 2173 When this option is not set, the module region will be randomized over 2174 a limited range that contains the [_stext, _etext] interval of the 2175 core kernel, so branch relocations are almost always in range unless 2176 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2177 particular case of region exhaustion, modules might be able to fall 2178 back to a larger 2GB area. 2179 2180config CC_HAVE_STACKPROTECTOR_SYSREG 2181 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2182 2183config STACKPROTECTOR_PER_TASK 2184 def_bool y 2185 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2186 2187config UNWIND_PATCH_PAC_INTO_SCS 2188 bool "Enable shadow call stack dynamically using code patching" 2189 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2190 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2191 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2192 depends on SHADOW_CALL_STACK 2193 select UNWIND_TABLES 2194 select DYNAMIC_SCS 2195 2196endmenu # "Kernel Features" 2197 2198menu "Boot options" 2199 2200config ARM64_ACPI_PARKING_PROTOCOL 2201 bool "Enable support for the ARM64 ACPI parking protocol" 2202 depends on ACPI 2203 help 2204 Enable support for the ARM64 ACPI parking protocol. If disabled 2205 the kernel will not allow booting through the ARM64 ACPI parking 2206 protocol even if the corresponding data is present in the ACPI 2207 MADT table. 2208 2209config CMDLINE 2210 string "Default kernel command string" 2211 default "" 2212 help 2213 Provide a set of default command-line options at build time by 2214 entering them here. As a minimum, you should specify the the 2215 root device (e.g. root=/dev/nfs). 2216 2217choice 2218 prompt "Kernel command line type" if CMDLINE != "" 2219 default CMDLINE_FROM_BOOTLOADER 2220 help 2221 Choose how the kernel will handle the provided default kernel 2222 command line string. 2223 2224config CMDLINE_FROM_BOOTLOADER 2225 bool "Use bootloader kernel arguments if available" 2226 help 2227 Uses the command-line options passed by the boot loader. If 2228 the boot loader doesn't provide any, the default kernel command 2229 string provided in CMDLINE will be used. 2230 2231config CMDLINE_FORCE 2232 bool "Always use the default kernel command string" 2233 help 2234 Always use the default kernel command string, even if the boot 2235 loader passes other arguments to the kernel. 2236 This is useful if you cannot or don't want to change the 2237 command-line options your boot loader passes to the kernel. 2238 2239endchoice 2240 2241config EFI_STUB 2242 bool 2243 2244config EFI 2245 bool "UEFI runtime support" 2246 depends on OF && !CPU_BIG_ENDIAN 2247 depends on KERNEL_MODE_NEON 2248 select ARCH_SUPPORTS_ACPI 2249 select LIBFDT 2250 select UCS2_STRING 2251 select EFI_PARAMS_FROM_FDT 2252 select EFI_RUNTIME_WRAPPERS 2253 select EFI_STUB 2254 select EFI_GENERIC_STUB 2255 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2256 default y 2257 help 2258 This option provides support for runtime services provided 2259 by UEFI firmware (such as non-volatile variables, realtime 2260 clock, and platform reset). A UEFI stub is also provided to 2261 allow the kernel to be booted as an EFI application. This 2262 is only useful on systems that have UEFI firmware. 2263 2264config DMI 2265 bool "Enable support for SMBIOS (DMI) tables" 2266 depends on EFI 2267 default y 2268 help 2269 This enables SMBIOS/DMI feature for systems. 2270 2271 This option is only useful on systems that have UEFI firmware. 2272 However, even with this option, the resultant kernel should 2273 continue to boot on existing non-UEFI platforms. 2274 2275endmenu # "Boot options" 2276 2277menu "Power management options" 2278 2279source "kernel/power/Kconfig" 2280 2281config ARCH_HIBERNATION_POSSIBLE 2282 def_bool y 2283 depends on CPU_PM 2284 2285config ARCH_HIBERNATION_HEADER 2286 def_bool y 2287 depends on HIBERNATION 2288 2289config ARCH_SUSPEND_POSSIBLE 2290 def_bool y 2291 2292endmenu # "Power management options" 2293 2294menu "CPU Power Management" 2295 2296source "drivers/cpuidle/Kconfig" 2297 2298source "drivers/cpufreq/Kconfig" 2299 2300endmenu # "CPU Power Management" 2301 2302source "drivers/acpi/Kconfig" 2303 2304source "arch/arm64/kvm/Kconfig" 2305 2306