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 CAVIUM_ERRATUM_22375 976 bool "Cavium erratum 22375, 24313" 977 default y 978 help 979 Enable workaround for errata 22375 and 24313. 980 981 This implements two gicv3-its errata workarounds for ThunderX. Both 982 with a small impact affecting only ITS table allocation. 983 984 erratum 22375: only alloc 8MB table size 985 erratum 24313: ignore memory access type 986 987 The fixes are in ITS initialization and basically ignore memory access 988 type and table size provided by the TYPER and BASER registers. 989 990 If unsure, say Y. 991 992config CAVIUM_ERRATUM_23144 993 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 994 depends on NUMA 995 default y 996 help 997 ITS SYNC command hang for cross node io and collections/cpu mapping. 998 999 If unsure, say Y. 1000 1001config CAVIUM_ERRATUM_23154 1002 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1003 default y 1004 help 1005 The ThunderX GICv3 implementation requires a modified version for 1006 reading the IAR status to ensure data synchronization 1007 (access to icc_iar1_el1 is not sync'ed before and after). 1008 1009 It also suffers from erratum 38545 (also present on Marvell's 1010 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1011 spuriously presented to the CPU interface. 1012 1013 If unsure, say Y. 1014 1015config CAVIUM_ERRATUM_27456 1016 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1017 default y 1018 help 1019 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1020 instructions may cause the icache to become corrupted if it 1021 contains data for a non-current ASID. The fix is to 1022 invalidate the icache when changing the mm context. 1023 1024 If unsure, say Y. 1025 1026config CAVIUM_ERRATUM_30115 1027 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1028 default y 1029 help 1030 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1031 1.2, and T83 Pass 1.0, KVM guest execution may disable 1032 interrupts in host. Trapping both GICv3 group-0 and group-1 1033 accesses sidesteps the issue. 1034 1035 If unsure, say Y. 1036 1037config CAVIUM_TX2_ERRATUM_219 1038 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1039 default y 1040 help 1041 On Cavium ThunderX2, a load, store or prefetch instruction between a 1042 TTBR update and the corresponding context synchronizing operation can 1043 cause a spurious Data Abort to be delivered to any hardware thread in 1044 the CPU core. 1045 1046 Work around the issue by avoiding the problematic code sequence and 1047 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1048 trap handler performs the corresponding register access, skips the 1049 instruction and ensures context synchronization by virtue of the 1050 exception return. 1051 1052 If unsure, say Y. 1053 1054config FUJITSU_ERRATUM_010001 1055 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1056 default y 1057 help 1058 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1059 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1060 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1061 This fault occurs under a specific hardware condition when a 1062 load/store instruction performs an address translation using: 1063 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1064 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1065 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1066 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1067 1068 The workaround is to ensure these bits are clear in TCR_ELx. 1069 The workaround only affects the Fujitsu-A64FX. 1070 1071 If unsure, say Y. 1072 1073config HISILICON_ERRATUM_161600802 1074 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1075 default y 1076 help 1077 The HiSilicon Hip07 SoC uses the wrong redistributor base 1078 when issued ITS commands such as VMOVP and VMAPP, and requires 1079 a 128kB offset to be applied to the target address in this commands. 1080 1081 If unsure, say Y. 1082 1083config QCOM_FALKOR_ERRATUM_1003 1084 bool "Falkor E1003: Incorrect translation due to ASID change" 1085 default y 1086 help 1087 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1088 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1089 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1090 then only for entries in the walk cache, since the leaf translation 1091 is unchanged. Work around the erratum by invalidating the walk cache 1092 entries for the trampoline before entering the kernel proper. 1093 1094config QCOM_FALKOR_ERRATUM_1009 1095 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1096 default y 1097 select ARM64_WORKAROUND_REPEAT_TLBI 1098 help 1099 On Falkor v1, the CPU may prematurely complete a DSB following a 1100 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1101 one more time to fix the issue. 1102 1103 If unsure, say Y. 1104 1105config QCOM_QDF2400_ERRATUM_0065 1106 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1107 default y 1108 help 1109 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1110 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1111 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1112 1113 If unsure, say Y. 1114 1115config QCOM_FALKOR_ERRATUM_E1041 1116 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1117 default y 1118 help 1119 Falkor CPU may speculatively fetch instructions from an improper 1120 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1121 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1122 1123 If unsure, say Y. 1124 1125config NVIDIA_CARMEL_CNP_ERRATUM 1126 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1127 default y 1128 help 1129 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1130 invalidate shared TLB entries installed by a different core, as it would 1131 on standard ARM cores. 1132 1133 If unsure, say Y. 1134 1135config SOCIONEXT_SYNQUACER_PREITS 1136 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1137 default y 1138 help 1139 Socionext Synquacer SoCs implement a separate h/w block to generate 1140 MSI doorbell writes with non-zero values for the device ID. 1141 1142 If unsure, say Y. 1143 1144endmenu # "ARM errata workarounds via the alternatives framework" 1145 1146choice 1147 prompt "Page size" 1148 default ARM64_4K_PAGES 1149 help 1150 Page size (translation granule) configuration. 1151 1152config ARM64_4K_PAGES 1153 bool "4KB" 1154 help 1155 This feature enables 4KB pages support. 1156 1157config ARM64_16K_PAGES 1158 bool "16KB" 1159 help 1160 The system will use 16KB pages support. AArch32 emulation 1161 requires applications compiled with 16K (or a multiple of 16K) 1162 aligned segments. 1163 1164config ARM64_64K_PAGES 1165 bool "64KB" 1166 help 1167 This feature enables 64KB pages support (4KB by default) 1168 allowing only two levels of page tables and faster TLB 1169 look-up. AArch32 emulation requires applications compiled 1170 with 64K aligned segments. 1171 1172endchoice 1173 1174choice 1175 prompt "Virtual address space size" 1176 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1177 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1178 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1179 help 1180 Allows choosing one of multiple possible virtual address 1181 space sizes. The level of translation table is determined by 1182 a combination of page size and virtual address space size. 1183 1184config ARM64_VA_BITS_36 1185 bool "36-bit" if EXPERT 1186 depends on ARM64_16K_PAGES 1187 1188config ARM64_VA_BITS_39 1189 bool "39-bit" 1190 depends on ARM64_4K_PAGES 1191 1192config ARM64_VA_BITS_42 1193 bool "42-bit" 1194 depends on ARM64_64K_PAGES 1195 1196config ARM64_VA_BITS_47 1197 bool "47-bit" 1198 depends on ARM64_16K_PAGES 1199 1200config ARM64_VA_BITS_48 1201 bool "48-bit" 1202 1203config ARM64_VA_BITS_52 1204 bool "52-bit" 1205 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1206 help 1207 Enable 52-bit virtual addressing for userspace when explicitly 1208 requested via a hint to mmap(). The kernel will also use 52-bit 1209 virtual addresses for its own mappings (provided HW support for 1210 this feature is available, otherwise it reverts to 48-bit). 1211 1212 NOTE: Enabling 52-bit virtual addressing in conjunction with 1213 ARMv8.3 Pointer Authentication will result in the PAC being 1214 reduced from 7 bits to 3 bits, which may have a significant 1215 impact on its susceptibility to brute-force attacks. 1216 1217 If unsure, select 48-bit virtual addressing instead. 1218 1219endchoice 1220 1221config ARM64_FORCE_52BIT 1222 bool "Force 52-bit virtual addresses for userspace" 1223 depends on ARM64_VA_BITS_52 && EXPERT 1224 help 1225 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1226 to maintain compatibility with older software by providing 48-bit VAs 1227 unless a hint is supplied to mmap. 1228 1229 This configuration option disables the 48-bit compatibility logic, and 1230 forces all userspace addresses to be 52-bit on HW that supports it. One 1231 should only enable this configuration option for stress testing userspace 1232 memory management code. If unsure say N here. 1233 1234config ARM64_VA_BITS 1235 int 1236 default 36 if ARM64_VA_BITS_36 1237 default 39 if ARM64_VA_BITS_39 1238 default 42 if ARM64_VA_BITS_42 1239 default 47 if ARM64_VA_BITS_47 1240 default 48 if ARM64_VA_BITS_48 1241 default 52 if ARM64_VA_BITS_52 1242 1243choice 1244 prompt "Physical address space size" 1245 default ARM64_PA_BITS_48 1246 help 1247 Choose the maximum physical address range that the kernel will 1248 support. 1249 1250config ARM64_PA_BITS_48 1251 bool "48-bit" 1252 1253config ARM64_PA_BITS_52 1254 bool "52-bit (ARMv8.2)" 1255 depends on ARM64_64K_PAGES 1256 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1257 help 1258 Enable support for a 52-bit physical address space, introduced as 1259 part of the ARMv8.2-LPA extension. 1260 1261 With this enabled, the kernel will also continue to work on CPUs that 1262 do not support ARMv8.2-LPA, but with some added memory overhead (and 1263 minor performance overhead). 1264 1265endchoice 1266 1267config ARM64_PA_BITS 1268 int 1269 default 48 if ARM64_PA_BITS_48 1270 default 52 if ARM64_PA_BITS_52 1271 1272choice 1273 prompt "Endianness" 1274 default CPU_LITTLE_ENDIAN 1275 help 1276 Select the endianness of data accesses performed by the CPU. Userspace 1277 applications will need to be compiled and linked for the endianness 1278 that is selected here. 1279 1280config CPU_BIG_ENDIAN 1281 bool "Build big-endian kernel" 1282 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1283 help 1284 Say Y if you plan on running a kernel with a big-endian userspace. 1285 1286config CPU_LITTLE_ENDIAN 1287 bool "Build little-endian kernel" 1288 help 1289 Say Y if you plan on running a kernel with a little-endian userspace. 1290 This is usually the case for distributions targeting arm64. 1291 1292endchoice 1293 1294config SCHED_MC 1295 bool "Multi-core scheduler support" 1296 help 1297 Multi-core scheduler support improves the CPU scheduler's decision 1298 making when dealing with multi-core CPU chips at a cost of slightly 1299 increased overhead in some places. If unsure say N here. 1300 1301config SCHED_CLUSTER 1302 bool "Cluster scheduler support" 1303 help 1304 Cluster scheduler support improves the CPU scheduler's decision 1305 making when dealing with machines that have clusters of CPUs. 1306 Cluster usually means a couple of CPUs which are placed closely 1307 by sharing mid-level caches, last-level cache tags or internal 1308 busses. 1309 1310config SCHED_SMT 1311 bool "SMT scheduler support" 1312 help 1313 Improves the CPU scheduler's decision making when dealing with 1314 MultiThreading at a cost of slightly increased overhead in some 1315 places. If unsure say N here. 1316 1317config NR_CPUS 1318 int "Maximum number of CPUs (2-4096)" 1319 range 2 4096 1320 default "256" 1321 1322config HOTPLUG_CPU 1323 bool "Support for hot-pluggable CPUs" 1324 select GENERIC_IRQ_MIGRATION 1325 help 1326 Say Y here to experiment with turning CPUs off and on. CPUs 1327 can be controlled through /sys/devices/system/cpu. 1328 1329# Common NUMA Features 1330config NUMA 1331 bool "NUMA Memory Allocation and Scheduler Support" 1332 select GENERIC_ARCH_NUMA 1333 select ACPI_NUMA if ACPI 1334 select OF_NUMA 1335 select HAVE_SETUP_PER_CPU_AREA 1336 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1337 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1338 select USE_PERCPU_NUMA_NODE_ID 1339 help 1340 Enable NUMA (Non-Uniform Memory Access) support. 1341 1342 The kernel will try to allocate memory used by a CPU on the 1343 local memory of the CPU and add some more 1344 NUMA awareness to the kernel. 1345 1346config NODES_SHIFT 1347 int "Maximum NUMA Nodes (as a power of 2)" 1348 range 1 10 1349 default "4" 1350 depends on NUMA 1351 help 1352 Specify the maximum number of NUMA Nodes available on the target 1353 system. Increases memory reserved to accommodate various tables. 1354 1355source "kernel/Kconfig.hz" 1356 1357config ARCH_SPARSEMEM_ENABLE 1358 def_bool y 1359 select SPARSEMEM_VMEMMAP_ENABLE 1360 select SPARSEMEM_VMEMMAP 1361 1362config HW_PERF_EVENTS 1363 def_bool y 1364 depends on ARM_PMU 1365 1366# Supported by clang >= 7.0 or GCC >= 12.0.0 1367config CC_HAVE_SHADOW_CALL_STACK 1368 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1369 1370config PARAVIRT 1371 bool "Enable paravirtualization code" 1372 help 1373 This changes the kernel so it can modify itself when it is run 1374 under a hypervisor, potentially improving performance significantly 1375 over full virtualization. 1376 1377config PARAVIRT_TIME_ACCOUNTING 1378 bool "Paravirtual steal time accounting" 1379 select PARAVIRT 1380 help 1381 Select this option to enable fine granularity task steal time 1382 accounting. Time spent executing other tasks in parallel with 1383 the current vCPU is discounted from the vCPU power. To account for 1384 that, there can be a small performance impact. 1385 1386 If in doubt, say N here. 1387 1388config KEXEC 1389 depends on PM_SLEEP_SMP 1390 select KEXEC_CORE 1391 bool "kexec system call" 1392 help 1393 kexec is a system call that implements the ability to shutdown your 1394 current kernel, and to start another kernel. It is like a reboot 1395 but it is independent of the system firmware. And like a reboot 1396 you can start any kernel with it, not just Linux. 1397 1398config KEXEC_FILE 1399 bool "kexec file based system call" 1400 select KEXEC_CORE 1401 select HAVE_IMA_KEXEC if IMA 1402 help 1403 This is new version of kexec system call. This system call is 1404 file based and takes file descriptors as system call argument 1405 for kernel and initramfs as opposed to list of segments as 1406 accepted by previous system call. 1407 1408config KEXEC_SIG 1409 bool "Verify kernel signature during kexec_file_load() syscall" 1410 depends on KEXEC_FILE 1411 help 1412 Select this option to verify a signature with loaded kernel 1413 image. If configured, any attempt of loading a image without 1414 valid signature will fail. 1415 1416 In addition to that option, you need to enable signature 1417 verification for the corresponding kernel image type being 1418 loaded in order for this to work. 1419 1420config KEXEC_IMAGE_VERIFY_SIG 1421 bool "Enable Image signature verification support" 1422 default y 1423 depends on KEXEC_SIG 1424 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1425 help 1426 Enable Image signature verification support. 1427 1428comment "Support for PE file signature verification disabled" 1429 depends on KEXEC_SIG 1430 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1431 1432config CRASH_DUMP 1433 bool "Build kdump crash kernel" 1434 help 1435 Generate crash dump after being started by kexec. This should 1436 be normally only set in special crash dump kernels which are 1437 loaded in the main kernel with kexec-tools into a specially 1438 reserved region and then later executed after a crash by 1439 kdump/kexec. 1440 1441 For more details see Documentation/admin-guide/kdump/kdump.rst 1442 1443config TRANS_TABLE 1444 def_bool y 1445 depends on HIBERNATION || KEXEC_CORE 1446 1447config XEN_DOM0 1448 def_bool y 1449 depends on XEN 1450 1451config XEN 1452 bool "Xen guest support on ARM64" 1453 depends on ARM64 && OF 1454 select SWIOTLB_XEN 1455 select PARAVIRT 1456 help 1457 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1458 1459config ARCH_FORCE_MAX_ORDER 1460 int 1461 default "14" if ARM64_64K_PAGES 1462 default "12" if ARM64_16K_PAGES 1463 default "11" 1464 help 1465 The kernel memory allocator divides physically contiguous memory 1466 blocks into "zones", where each zone is a power of two number of 1467 pages. This option selects the largest power of two that the kernel 1468 keeps in the memory allocator. If you need to allocate very large 1469 blocks of physically contiguous memory, then you may need to 1470 increase this value. 1471 1472 This config option is actually maximum order plus one. For example, 1473 a value of 11 means that the largest free memory block is 2^10 pages. 1474 1475 We make sure that we can allocate upto a HugePage size for each configuration. 1476 Hence we have : 1477 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1478 1479 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1480 4M allocations matching the default size used by generic code. 1481 1482config UNMAP_KERNEL_AT_EL0 1483 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1484 default y 1485 help 1486 Speculation attacks against some high-performance processors can 1487 be used to bypass MMU permission checks and leak kernel data to 1488 userspace. This can be defended against by unmapping the kernel 1489 when running in userspace, mapping it back in on exception entry 1490 via a trampoline page in the vector table. 1491 1492 If unsure, say Y. 1493 1494config MITIGATE_SPECTRE_BRANCH_HISTORY 1495 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1496 default y 1497 help 1498 Speculation attacks against some high-performance processors can 1499 make use of branch history to influence future speculation. 1500 When taking an exception from user-space, a sequence of branches 1501 or a firmware call overwrites the branch history. 1502 1503config RODATA_FULL_DEFAULT_ENABLED 1504 bool "Apply r/o permissions of VM areas also to their linear aliases" 1505 default y 1506 help 1507 Apply read-only attributes of VM areas to the linear alias of 1508 the backing pages as well. This prevents code or read-only data 1509 from being modified (inadvertently or intentionally) via another 1510 mapping of the same memory page. This additional enhancement can 1511 be turned off at runtime by passing rodata=[off|on] (and turned on 1512 with rodata=full if this option is set to 'n') 1513 1514 This requires the linear region to be mapped down to pages, 1515 which may adversely affect performance in some cases. 1516 1517config ARM64_SW_TTBR0_PAN 1518 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1519 help 1520 Enabling this option prevents the kernel from accessing 1521 user-space memory directly by pointing TTBR0_EL1 to a reserved 1522 zeroed area and reserved ASID. The user access routines 1523 restore the valid TTBR0_EL1 temporarily. 1524 1525config ARM64_TAGGED_ADDR_ABI 1526 bool "Enable the tagged user addresses syscall ABI" 1527 default y 1528 help 1529 When this option is enabled, user applications can opt in to a 1530 relaxed ABI via prctl() allowing tagged addresses to be passed 1531 to system calls as pointer arguments. For details, see 1532 Documentation/arm64/tagged-address-abi.rst. 1533 1534menuconfig COMPAT 1535 bool "Kernel support for 32-bit EL0" 1536 depends on ARM64_4K_PAGES || EXPERT 1537 select HAVE_UID16 1538 select OLD_SIGSUSPEND3 1539 select COMPAT_OLD_SIGACTION 1540 help 1541 This option enables support for a 32-bit EL0 running under a 64-bit 1542 kernel at EL1. AArch32-specific components such as system calls, 1543 the user helper functions, VFP support and the ptrace interface are 1544 handled appropriately by the kernel. 1545 1546 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1547 that you will only be able to execute AArch32 binaries that were compiled 1548 with page size aligned segments. 1549 1550 If you want to execute 32-bit userspace applications, say Y. 1551 1552if COMPAT 1553 1554config KUSER_HELPERS 1555 bool "Enable kuser helpers page for 32-bit applications" 1556 default y 1557 help 1558 Warning: disabling this option may break 32-bit user programs. 1559 1560 Provide kuser helpers to compat tasks. The kernel provides 1561 helper code to userspace in read only form at a fixed location 1562 to allow userspace to be independent of the CPU type fitted to 1563 the system. This permits binaries to be run on ARMv4 through 1564 to ARMv8 without modification. 1565 1566 See Documentation/arm/kernel_user_helpers.rst for details. 1567 1568 However, the fixed address nature of these helpers can be used 1569 by ROP (return orientated programming) authors when creating 1570 exploits. 1571 1572 If all of the binaries and libraries which run on your platform 1573 are built specifically for your platform, and make no use of 1574 these helpers, then you can turn this option off to hinder 1575 such exploits. However, in that case, if a binary or library 1576 relying on those helpers is run, it will not function correctly. 1577 1578 Say N here only if you are absolutely certain that you do not 1579 need these helpers; otherwise, the safe option is to say Y. 1580 1581config COMPAT_VDSO 1582 bool "Enable vDSO for 32-bit applications" 1583 depends on !CPU_BIG_ENDIAN 1584 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1585 select GENERIC_COMPAT_VDSO 1586 default y 1587 help 1588 Place in the process address space of 32-bit applications an 1589 ELF shared object providing fast implementations of gettimeofday 1590 and clock_gettime. 1591 1592 You must have a 32-bit build of glibc 2.22 or later for programs 1593 to seamlessly take advantage of this. 1594 1595config THUMB2_COMPAT_VDSO 1596 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1597 depends on COMPAT_VDSO 1598 default y 1599 help 1600 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1601 otherwise with '-marm'. 1602 1603config COMPAT_ALIGNMENT_FIXUPS 1604 bool "Fix up misaligned multi-word loads and stores in user space" 1605 1606menuconfig ARMV8_DEPRECATED 1607 bool "Emulate deprecated/obsolete ARMv8 instructions" 1608 depends on SYSCTL 1609 help 1610 Legacy software support may require certain instructions 1611 that have been deprecated or obsoleted in the architecture. 1612 1613 Enable this config to enable selective emulation of these 1614 features. 1615 1616 If unsure, say Y 1617 1618if ARMV8_DEPRECATED 1619 1620config SWP_EMULATION 1621 bool "Emulate SWP/SWPB instructions" 1622 help 1623 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1624 they are always undefined. Say Y here to enable software 1625 emulation of these instructions for userspace using LDXR/STXR. 1626 This feature can be controlled at runtime with the abi.swp 1627 sysctl which is disabled by default. 1628 1629 In some older versions of glibc [<=2.8] SWP is used during futex 1630 trylock() operations with the assumption that the code will not 1631 be preempted. This invalid assumption may be more likely to fail 1632 with SWP emulation enabled, leading to deadlock of the user 1633 application. 1634 1635 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1636 on an external transaction monitoring block called a global 1637 monitor to maintain update atomicity. If your system does not 1638 implement a global monitor, this option can cause programs that 1639 perform SWP operations to uncached memory to deadlock. 1640 1641 If unsure, say Y 1642 1643config CP15_BARRIER_EMULATION 1644 bool "Emulate CP15 Barrier instructions" 1645 help 1646 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1647 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1648 strongly recommended to use the ISB, DSB, and DMB 1649 instructions instead. 1650 1651 Say Y here to enable software emulation of these 1652 instructions for AArch32 userspace code. When this option is 1653 enabled, CP15 barrier usage is traced which can help 1654 identify software that needs updating. This feature can be 1655 controlled at runtime with the abi.cp15_barrier sysctl. 1656 1657 If unsure, say Y 1658 1659config SETEND_EMULATION 1660 bool "Emulate SETEND instruction" 1661 help 1662 The SETEND instruction alters the data-endianness of the 1663 AArch32 EL0, and is deprecated in ARMv8. 1664 1665 Say Y here to enable software emulation of the instruction 1666 for AArch32 userspace code. This feature can be controlled 1667 at runtime with the abi.setend sysctl. 1668 1669 Note: All the cpus on the system must have mixed endian support at EL0 1670 for this feature to be enabled. If a new CPU - which doesn't support mixed 1671 endian - is hotplugged in after this feature has been enabled, there could 1672 be unexpected results in the applications. 1673 1674 If unsure, say Y 1675endif # ARMV8_DEPRECATED 1676 1677endif # COMPAT 1678 1679menu "ARMv8.1 architectural features" 1680 1681config ARM64_HW_AFDBM 1682 bool "Support for hardware updates of the Access and Dirty page flags" 1683 default y 1684 help 1685 The ARMv8.1 architecture extensions introduce support for 1686 hardware updates of the access and dirty information in page 1687 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1688 capable processors, accesses to pages with PTE_AF cleared will 1689 set this bit instead of raising an access flag fault. 1690 Similarly, writes to read-only pages with the DBM bit set will 1691 clear the read-only bit (AP[2]) instead of raising a 1692 permission fault. 1693 1694 Kernels built with this configuration option enabled continue 1695 to work on pre-ARMv8.1 hardware and the performance impact is 1696 minimal. If unsure, say Y. 1697 1698config ARM64_PAN 1699 bool "Enable support for Privileged Access Never (PAN)" 1700 default y 1701 help 1702 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1703 prevents the kernel or hypervisor from accessing user-space (EL0) 1704 memory directly. 1705 1706 Choosing this option will cause any unprotected (not using 1707 copy_to_user et al) memory access to fail with a permission fault. 1708 1709 The feature is detected at runtime, and will remain as a 'nop' 1710 instruction if the cpu does not implement the feature. 1711 1712config AS_HAS_LDAPR 1713 def_bool $(as-instr,.arch_extension rcpc) 1714 1715config AS_HAS_LSE_ATOMICS 1716 def_bool $(as-instr,.arch_extension lse) 1717 1718config ARM64_LSE_ATOMICS 1719 bool 1720 default ARM64_USE_LSE_ATOMICS 1721 depends on AS_HAS_LSE_ATOMICS 1722 1723config ARM64_USE_LSE_ATOMICS 1724 bool "Atomic instructions" 1725 default y 1726 help 1727 As part of the Large System Extensions, ARMv8.1 introduces new 1728 atomic instructions that are designed specifically to scale in 1729 very large systems. 1730 1731 Say Y here to make use of these instructions for the in-kernel 1732 atomic routines. This incurs a small overhead on CPUs that do 1733 not support these instructions and requires the kernel to be 1734 built with binutils >= 2.25 in order for the new instructions 1735 to be used. 1736 1737endmenu # "ARMv8.1 architectural features" 1738 1739menu "ARMv8.2 architectural features" 1740 1741config AS_HAS_ARMV8_2 1742 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1743 1744config AS_HAS_SHA3 1745 def_bool $(as-instr,.arch armv8.2-a+sha3) 1746 1747config ARM64_PMEM 1748 bool "Enable support for persistent memory" 1749 select ARCH_HAS_PMEM_API 1750 select ARCH_HAS_UACCESS_FLUSHCACHE 1751 help 1752 Say Y to enable support for the persistent memory API based on the 1753 ARMv8.2 DCPoP feature. 1754 1755 The feature is detected at runtime, and the kernel will use DC CVAC 1756 operations if DC CVAP is not supported (following the behaviour of 1757 DC CVAP itself if the system does not define a point of persistence). 1758 1759config ARM64_RAS_EXTN 1760 bool "Enable support for RAS CPU Extensions" 1761 default y 1762 help 1763 CPUs that support the Reliability, Availability and Serviceability 1764 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1765 errors, classify them and report them to software. 1766 1767 On CPUs with these extensions system software can use additional 1768 barriers to determine if faults are pending and read the 1769 classification from a new set of registers. 1770 1771 Selecting this feature will allow the kernel to use these barriers 1772 and access the new registers if the system supports the extension. 1773 Platform RAS features may additionally depend on firmware support. 1774 1775config ARM64_CNP 1776 bool "Enable support for Common Not Private (CNP) translations" 1777 default y 1778 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1779 help 1780 Common Not Private (CNP) allows translation table entries to 1781 be shared between different PEs in the same inner shareable 1782 domain, so the hardware can use this fact to optimise the 1783 caching of such entries in the TLB. 1784 1785 Selecting this option allows the CNP feature to be detected 1786 at runtime, and does not affect PEs that do not implement 1787 this feature. 1788 1789endmenu # "ARMv8.2 architectural features" 1790 1791menu "ARMv8.3 architectural features" 1792 1793config ARM64_PTR_AUTH 1794 bool "Enable support for pointer authentication" 1795 default y 1796 help 1797 Pointer authentication (part of the ARMv8.3 Extensions) provides 1798 instructions for signing and authenticating pointers against secret 1799 keys, which can be used to mitigate Return Oriented Programming (ROP) 1800 and other attacks. 1801 1802 This option enables these instructions at EL0 (i.e. for userspace). 1803 Choosing this option will cause the kernel to initialise secret keys 1804 for each process at exec() time, with these keys being 1805 context-switched along with the process. 1806 1807 The feature is detected at runtime. If the feature is not present in 1808 hardware it will not be advertised to userspace/KVM guest nor will it 1809 be enabled. 1810 1811 If the feature is present on the boot CPU but not on a late CPU, then 1812 the late CPU will be parked. Also, if the boot CPU does not have 1813 address auth and the late CPU has then the late CPU will still boot 1814 but with the feature disabled. On such a system, this option should 1815 not be selected. 1816 1817config ARM64_PTR_AUTH_KERNEL 1818 bool "Use pointer authentication for kernel" 1819 default y 1820 depends on ARM64_PTR_AUTH 1821 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1822 # Modern compilers insert a .note.gnu.property section note for PAC 1823 # which is only understood by binutils starting with version 2.33.1. 1824 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1825 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1826 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1827 help 1828 If the compiler supports the -mbranch-protection or 1829 -msign-return-address flag (e.g. GCC 7 or later), then this option 1830 will cause the kernel itself to be compiled with return address 1831 protection. In this case, and if the target hardware is known to 1832 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1833 disabled with minimal loss of protection. 1834 1835 This feature works with FUNCTION_GRAPH_TRACER option only if 1836 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1837 1838config CC_HAS_BRANCH_PROT_PAC_RET 1839 # GCC 9 or later, clang 8 or later 1840 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1841 1842config CC_HAS_SIGN_RETURN_ADDRESS 1843 # GCC 7, 8 1844 def_bool $(cc-option,-msign-return-address=all) 1845 1846config AS_HAS_PAC 1847 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1848 1849config AS_HAS_CFI_NEGATE_RA_STATE 1850 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1851 1852endmenu # "ARMv8.3 architectural features" 1853 1854menu "ARMv8.4 architectural features" 1855 1856config ARM64_AMU_EXTN 1857 bool "Enable support for the Activity Monitors Unit CPU extension" 1858 default y 1859 help 1860 The activity monitors extension is an optional extension introduced 1861 by the ARMv8.4 CPU architecture. This enables support for version 1 1862 of the activity monitors architecture, AMUv1. 1863 1864 To enable the use of this extension on CPUs that implement it, say Y. 1865 1866 Note that for architectural reasons, firmware _must_ implement AMU 1867 support when running on CPUs that present the activity monitors 1868 extension. The required support is present in: 1869 * Version 1.5 and later of the ARM Trusted Firmware 1870 1871 For kernels that have this configuration enabled but boot with broken 1872 firmware, you may need to say N here until the firmware is fixed. 1873 Otherwise you may experience firmware panics or lockups when 1874 accessing the counter registers. Even if you are not observing these 1875 symptoms, the values returned by the register reads might not 1876 correctly reflect reality. Most commonly, the value read will be 0, 1877 indicating that the counter is not enabled. 1878 1879config AS_HAS_ARMV8_4 1880 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1881 1882config ARM64_TLB_RANGE 1883 bool "Enable support for tlbi range feature" 1884 default y 1885 depends on AS_HAS_ARMV8_4 1886 help 1887 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1888 range of input addresses. 1889 1890 The feature introduces new assembly instructions, and they were 1891 support when binutils >= 2.30. 1892 1893endmenu # "ARMv8.4 architectural features" 1894 1895menu "ARMv8.5 architectural features" 1896 1897config AS_HAS_ARMV8_5 1898 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1899 1900config ARM64_BTI 1901 bool "Branch Target Identification support" 1902 default y 1903 help 1904 Branch Target Identification (part of the ARMv8.5 Extensions) 1905 provides a mechanism to limit the set of locations to which computed 1906 branch instructions such as BR or BLR can jump. 1907 1908 To make use of BTI on CPUs that support it, say Y. 1909 1910 BTI is intended to provide complementary protection to other control 1911 flow integrity protection mechanisms, such as the Pointer 1912 authentication mechanism provided as part of the ARMv8.3 Extensions. 1913 For this reason, it does not make sense to enable this option without 1914 also enabling support for pointer authentication. Thus, when 1915 enabling this option you should also select ARM64_PTR_AUTH=y. 1916 1917 Userspace binaries must also be specifically compiled to make use of 1918 this mechanism. If you say N here or the hardware does not support 1919 BTI, such binaries can still run, but you get no additional 1920 enforcement of branch destinations. 1921 1922config ARM64_BTI_KERNEL 1923 bool "Use Branch Target Identification for kernel" 1924 default y 1925 depends on ARM64_BTI 1926 depends on ARM64_PTR_AUTH_KERNEL 1927 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1928 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1929 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1930 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1931 depends on !CC_IS_GCC 1932 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1933 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1934 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1935 help 1936 Build the kernel with Branch Target Identification annotations 1937 and enable enforcement of this for kernel code. When this option 1938 is enabled and the system supports BTI all kernel code including 1939 modular code must have BTI enabled. 1940 1941config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1942 # GCC 9 or later, clang 8 or later 1943 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1944 1945config ARM64_E0PD 1946 bool "Enable support for E0PD" 1947 default y 1948 help 1949 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1950 that EL0 accesses made via TTBR1 always fault in constant time, 1951 providing similar benefits to KASLR as those provided by KPTI, but 1952 with lower overhead and without disrupting legitimate access to 1953 kernel memory such as SPE. 1954 1955 This option enables E0PD for TTBR1 where available. 1956 1957config ARM64_AS_HAS_MTE 1958 # Initial support for MTE went in binutils 2.32.0, checked with 1959 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1960 # as a late addition to the final architecture spec (LDGM/STGM) 1961 # is only supported in the newer 2.32.x and 2.33 binutils 1962 # versions, hence the extra "stgm" instruction check below. 1963 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1964 1965config ARM64_MTE 1966 bool "Memory Tagging Extension support" 1967 default y 1968 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1969 depends on AS_HAS_ARMV8_5 1970 depends on AS_HAS_LSE_ATOMICS 1971 # Required for tag checking in the uaccess routines 1972 depends on ARM64_PAN 1973 select ARCH_HAS_SUBPAGE_FAULTS 1974 select ARCH_USES_HIGH_VMA_FLAGS 1975 select ARCH_USES_PG_ARCH_X 1976 help 1977 Memory Tagging (part of the ARMv8.5 Extensions) provides 1978 architectural support for run-time, always-on detection of 1979 various classes of memory error to aid with software debugging 1980 to eliminate vulnerabilities arising from memory-unsafe 1981 languages. 1982 1983 This option enables the support for the Memory Tagging 1984 Extension at EL0 (i.e. for userspace). 1985 1986 Selecting this option allows the feature to be detected at 1987 runtime. Any secondary CPU not implementing this feature will 1988 not be allowed a late bring-up. 1989 1990 Userspace binaries that want to use this feature must 1991 explicitly opt in. The mechanism for the userspace is 1992 described in: 1993 1994 Documentation/arm64/memory-tagging-extension.rst. 1995 1996endmenu # "ARMv8.5 architectural features" 1997 1998menu "ARMv8.7 architectural features" 1999 2000config ARM64_EPAN 2001 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2002 default y 2003 depends on ARM64_PAN 2004 help 2005 Enhanced Privileged Access Never (EPAN) allows Privileged 2006 Access Never to be used with Execute-only mappings. 2007 2008 The feature is detected at runtime, and will remain disabled 2009 if the cpu does not implement the feature. 2010endmenu # "ARMv8.7 architectural features" 2011 2012config ARM64_SVE 2013 bool "ARM Scalable Vector Extension support" 2014 default y 2015 help 2016 The Scalable Vector Extension (SVE) is an extension to the AArch64 2017 execution state which complements and extends the SIMD functionality 2018 of the base architecture to support much larger vectors and to enable 2019 additional vectorisation opportunities. 2020 2021 To enable use of this extension on CPUs that implement it, say Y. 2022 2023 On CPUs that support the SVE2 extensions, this option will enable 2024 those too. 2025 2026 Note that for architectural reasons, firmware _must_ implement SVE 2027 support when running on SVE capable hardware. The required support 2028 is present in: 2029 2030 * version 1.5 and later of the ARM Trusted Firmware 2031 * the AArch64 boot wrapper since commit 5e1261e08abf 2032 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2033 2034 For other firmware implementations, consult the firmware documentation 2035 or vendor. 2036 2037 If you need the kernel to boot on SVE-capable hardware with broken 2038 firmware, you may need to say N here until you get your firmware 2039 fixed. Otherwise, you may experience firmware panics or lockups when 2040 booting the kernel. If unsure and you are not observing these 2041 symptoms, you should assume that it is safe to say Y. 2042 2043config ARM64_SME 2044 bool "ARM Scalable Matrix Extension support" 2045 default y 2046 depends on ARM64_SVE 2047 help 2048 The Scalable Matrix Extension (SME) is an extension to the AArch64 2049 execution state which utilises a substantial subset of the SVE 2050 instruction set, together with the addition of new architectural 2051 register state capable of holding two dimensional matrix tiles to 2052 enable various matrix operations. 2053 2054config ARM64_MODULE_PLTS 2055 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2056 depends on MODULES 2057 select HAVE_MOD_ARCH_SPECIFIC 2058 help 2059 Allocate PLTs when loading modules so that jumps and calls whose 2060 targets are too far away for their relative offsets to be encoded 2061 in the instructions themselves can be bounced via veneers in the 2062 module's PLT. This allows modules to be allocated in the generic 2063 vmalloc area after the dedicated module memory area has been 2064 exhausted. 2065 2066 When running with address space randomization (KASLR), the module 2067 region itself may be too far away for ordinary relative jumps and 2068 calls, and so in that case, module PLTs are required and cannot be 2069 disabled. 2070 2071 Specific errata workaround(s) might also force module PLTs to be 2072 enabled (ARM64_ERRATUM_843419). 2073 2074config ARM64_PSEUDO_NMI 2075 bool "Support for NMI-like interrupts" 2076 select ARM_GIC_V3 2077 help 2078 Adds support for mimicking Non-Maskable Interrupts through the use of 2079 GIC interrupt priority. This support requires version 3 or later of 2080 ARM GIC. 2081 2082 This high priority configuration for interrupts needs to be 2083 explicitly enabled by setting the kernel parameter 2084 "irqchip.gicv3_pseudo_nmi" to 1. 2085 2086 If unsure, say N 2087 2088if ARM64_PSEUDO_NMI 2089config ARM64_DEBUG_PRIORITY_MASKING 2090 bool "Debug interrupt priority masking" 2091 help 2092 This adds runtime checks to functions enabling/disabling 2093 interrupts when using priority masking. The additional checks verify 2094 the validity of ICC_PMR_EL1 when calling concerned functions. 2095 2096 If unsure, say N 2097endif # ARM64_PSEUDO_NMI 2098 2099config RELOCATABLE 2100 bool "Build a relocatable kernel image" if EXPERT 2101 select ARCH_HAS_RELR 2102 default y 2103 help 2104 This builds the kernel as a Position Independent Executable (PIE), 2105 which retains all relocation metadata required to relocate the 2106 kernel binary at runtime to a different virtual address than the 2107 address it was linked at. 2108 Since AArch64 uses the RELA relocation format, this requires a 2109 relocation pass at runtime even if the kernel is loaded at the 2110 same address it was linked at. 2111 2112config RANDOMIZE_BASE 2113 bool "Randomize the address of the kernel image" 2114 select ARM64_MODULE_PLTS if MODULES 2115 select RELOCATABLE 2116 help 2117 Randomizes the virtual address at which the kernel image is 2118 loaded, as a security feature that deters exploit attempts 2119 relying on knowledge of the location of kernel internals. 2120 2121 It is the bootloader's job to provide entropy, by passing a 2122 random u64 value in /chosen/kaslr-seed at kernel entry. 2123 2124 When booting via the UEFI stub, it will invoke the firmware's 2125 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2126 to the kernel proper. In addition, it will randomise the physical 2127 location of the kernel Image as well. 2128 2129 If unsure, say N. 2130 2131config RANDOMIZE_MODULE_REGION_FULL 2132 bool "Randomize the module region over a 2 GB range" 2133 depends on RANDOMIZE_BASE 2134 default y 2135 help 2136 Randomizes the location of the module region inside a 2 GB window 2137 covering the core kernel. This way, it is less likely for modules 2138 to leak information about the location of core kernel data structures 2139 but it does imply that function calls between modules and the core 2140 kernel will need to be resolved via veneers in the module PLT. 2141 2142 When this option is not set, the module region will be randomized over 2143 a limited range that contains the [_stext, _etext] interval of the 2144 core kernel, so branch relocations are almost always in range unless 2145 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2146 particular case of region exhaustion, modules might be able to fall 2147 back to a larger 2GB area. 2148 2149config CC_HAVE_STACKPROTECTOR_SYSREG 2150 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2151 2152config STACKPROTECTOR_PER_TASK 2153 def_bool y 2154 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2155 2156config UNWIND_PATCH_PAC_INTO_SCS 2157 bool "Enable shadow call stack dynamically using code patching" 2158 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2159 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2160 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2161 depends on SHADOW_CALL_STACK 2162 select UNWIND_TABLES 2163 select DYNAMIC_SCS 2164 2165endmenu # "Kernel Features" 2166 2167menu "Boot options" 2168 2169config ARM64_ACPI_PARKING_PROTOCOL 2170 bool "Enable support for the ARM64 ACPI parking protocol" 2171 depends on ACPI 2172 help 2173 Enable support for the ARM64 ACPI parking protocol. If disabled 2174 the kernel will not allow booting through the ARM64 ACPI parking 2175 protocol even if the corresponding data is present in the ACPI 2176 MADT table. 2177 2178config CMDLINE 2179 string "Default kernel command string" 2180 default "" 2181 help 2182 Provide a set of default command-line options at build time by 2183 entering them here. As a minimum, you should specify the the 2184 root device (e.g. root=/dev/nfs). 2185 2186choice 2187 prompt "Kernel command line type" if CMDLINE != "" 2188 default CMDLINE_FROM_BOOTLOADER 2189 help 2190 Choose how the kernel will handle the provided default kernel 2191 command line string. 2192 2193config CMDLINE_FROM_BOOTLOADER 2194 bool "Use bootloader kernel arguments if available" 2195 help 2196 Uses the command-line options passed by the boot loader. If 2197 the boot loader doesn't provide any, the default kernel command 2198 string provided in CMDLINE will be used. 2199 2200config CMDLINE_FORCE 2201 bool "Always use the default kernel command string" 2202 help 2203 Always use the default kernel command string, even if the boot 2204 loader passes other arguments to the kernel. 2205 This is useful if you cannot or don't want to change the 2206 command-line options your boot loader passes to the kernel. 2207 2208endchoice 2209 2210config EFI_STUB 2211 bool 2212 2213config EFI 2214 bool "UEFI runtime support" 2215 depends on OF && !CPU_BIG_ENDIAN 2216 depends on KERNEL_MODE_NEON 2217 select ARCH_SUPPORTS_ACPI 2218 select LIBFDT 2219 select UCS2_STRING 2220 select EFI_PARAMS_FROM_FDT 2221 select EFI_RUNTIME_WRAPPERS 2222 select EFI_STUB 2223 select EFI_GENERIC_STUB 2224 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2225 default y 2226 help 2227 This option provides support for runtime services provided 2228 by UEFI firmware (such as non-volatile variables, realtime 2229 clock, and platform reset). A UEFI stub is also provided to 2230 allow the kernel to be booted as an EFI application. This 2231 is only useful on systems that have UEFI firmware. 2232 2233config DMI 2234 bool "Enable support for SMBIOS (DMI) tables" 2235 depends on EFI 2236 default y 2237 help 2238 This enables SMBIOS/DMI feature for systems. 2239 2240 This option is only useful on systems that have UEFI firmware. 2241 However, even with this option, the resultant kernel should 2242 continue to boot on existing non-UEFI platforms. 2243 2244endmenu # "Boot options" 2245 2246menu "Power management options" 2247 2248source "kernel/power/Kconfig" 2249 2250config ARCH_HIBERNATION_POSSIBLE 2251 def_bool y 2252 depends on CPU_PM 2253 2254config ARCH_HIBERNATION_HEADER 2255 def_bool y 2256 depends on HIBERNATION 2257 2258config ARCH_SUSPEND_POSSIBLE 2259 def_bool y 2260 2261endmenu # "Power management options" 2262 2263menu "CPU Power Management" 2264 2265source "drivers/cpuidle/Kconfig" 2266 2267source "drivers/cpufreq/Kconfig" 2268 2269endmenu # "CPU Power Management" 2270 2271source "drivers/acpi/Kconfig" 2272 2273source "arch/arm64/kvm/Kconfig" 2274 2275