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_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 20 select ARCH_HAS_PMD_SOFTLEAVES if TRANSPARENT_HUGEPAGE 21 select ARCH_HAS_CACHE_LINE_SIZE 22 select ARCH_HAS_CC_PLATFORM 23 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 24 select ARCH_HAS_CURRENT_STACK_POINTER 25 select ARCH_HAS_DEBUG_VIRTUAL 26 select ARCH_HAS_DEBUG_VM_PGTABLE 27 select ARCH_HAS_DMA_OPS if XEN 28 select ARCH_HAS_DMA_PREP_COHERENT 29 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 30 select ARCH_HAS_FAST_MULTIPLIER 31 select ARCH_HAS_FORTIFY_SOURCE 32 select ARCH_HAS_GCOV_PROFILE_ALL 33 select ARCH_HAS_GIGANTIC_PAGE 34 select ARCH_HAS_KCOV 35 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 36 select ARCH_HAS_KEEPINITRD 37 select ARCH_HAS_LAZY_MMU_MODE 38 select ARCH_HAS_MEMBARRIER_SYNC_CORE 39 select ARCH_HAS_MEM_ENCRYPT 40 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 41 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 42 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 43 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 44 select ARCH_HAS_PREEMPT_LAZY 45 select ARCH_HAS_PTDUMP 46 select ARCH_HAS_PTE_SPECIAL 47 select ARCH_HAS_HW_PTE_YOUNG 48 select ARCH_HAS_SETUP_DMA_OPS 49 select ARCH_HAS_SET_DIRECT_MAP 50 select ARCH_HAS_SET_MEMORY 51 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 52 select ARCH_STACKWALK 53 select ARCH_HAS_STRICT_KERNEL_RWX 54 select ARCH_HAS_STRICT_MODULE_RWX 55 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 56 select ARCH_HAS_SYNC_DMA_FOR_CPU 57 select ARCH_HAS_BATCHED_DMA_SYNC 58 select ARCH_HAS_SYSCALL_WRAPPER 59 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 60 select ARCH_HAS_ZONE_DMA_SET if EXPERT 61 select ARCH_HAVE_ELF_PROT 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_HAVE_TRACE_MMIO_ACCESS 64 select ARCH_KEEP_MEMBLOCK 65 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 66 select ARCH_USE_CMPXCHG_LOCKREF 67 select ARCH_USE_GNU_PROPERTY 68 select ARCH_USE_MEMTEST 69 select ARCH_USE_QUEUED_RWLOCKS 70 select ARCH_USE_QUEUED_SPINLOCKS 71 select ARCH_USE_SYM_ANNOTATIONS 72 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 73 select ARCH_SUPPORTS_HUGETLBFS 74 select ARCH_SUPPORTS_MEMORY_FAILURE 75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 76 select ARCH_SUPPORTS_LTO_CLANG 77 select ARCH_SUPPORTS_LTO_CLANG_THIN 78 select ARCH_SUPPORTS_CFI 79 select ARCH_SUPPORTS_ATOMIC_RMW 80 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 81 select ARCH_HAS_PTE_PROTNONE 82 select ARCH_SUPPORTS_NUMA_BALANCING 83 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 84 select ARCH_SUPPORTS_PER_VMA_LOCK 85 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 86 select ARCH_SUPPORTS_RMM 87 select ARCH_SUPPORTS_RT 88 select ARCH_SUPPORTS_SCHED_SMT 89 select ARCH_SUPPORTS_SCHED_CLUSTER 90 select ARCH_SUPPORTS_SCHED_MC 91 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 92 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 93 select ARCH_WANT_DEFAULT_BPF_JIT 94 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 95 select ARCH_WANT_FRAME_POINTERS 96 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 97 select ARCH_WANT_LD_ORPHAN_WARN 98 select ARCH_WANTS_EXECMEM_LATE 99 select ARCH_WANTS_NO_INSTR 100 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 101 select ARCH_HAS_UBSAN 102 select ARM_AMBA 103 select ARM_ARCH_TIMER 104 select ARM_GIC 105 select AUDIT_ARCH_COMPAT_GENERIC 106 select ARM_GIC_V2M if PCI 107 select ARM_GIC_V3 108 select ARM_GIC_V3_ITS if PCI 109 select ARM_GIC_V5 110 select ARM_PSCI_FW 111 select BUILDTIME_TABLE_SORT 112 select CLONE_BACKWARDS 113 select COMMON_CLK 114 select CPU_PM if (SUSPEND || CPU_IDLE) 115 select CPUMASK_OFFSTACK if NR_CPUS > 256 116 select DCACHE_WORD_ACCESS 117 select HAVE_EXTRA_IPI_TRACEPOINTS 118 select DYNAMIC_FTRACE if FUNCTION_TRACER 119 select DMA_BOUNCE_UNALIGNED_KMALLOC 120 select DMA_DIRECT_REMAP 121 select EDAC_SUPPORT 122 select FRAME_POINTER 123 select FUNCTION_ALIGNMENT_4B 124 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 125 select GENERIC_ALLOCATOR 126 select GENERIC_ARCH_TOPOLOGY 127 select GENERIC_CLOCKEVENTS_BROADCAST 128 select GENERIC_CPU_AUTOPROBE 129 select GENERIC_CPU_CACHE_MAINTENANCE 130 select GENERIC_CPU_DEVICES 131 select GENERIC_CPU_VULNERABILITIES 132 select GENERIC_EARLY_IOREMAP 133 select GENERIC_IDLE_POLL_SETUP 134 select GENERIC_IOREMAP 135 select GENERIC_IRQ_ENTRY 136 select GENERIC_IRQ_IPI 137 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 138 select GENERIC_IRQ_PROBE 139 select GENERIC_IRQ_SHOW 140 select GENERIC_IRQ_SHOW_LEVEL 141 select GENERIC_LIB_DEVMEM_IS_ALLOWED 142 select GENERIC_PCI_IOMAP 143 select GENERIC_SCHED_CLOCK 144 select GENERIC_SMP_IDLE_THREAD 145 select GENERIC_GETTIMEOFDAY 146 select HARDIRQS_SW_RESEND 147 select HAS_IOPORT 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 153 select HAVE_ARCH_AUDITSYSCALL 154 select HAVE_ARCH_BITREVERSE if 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 161 select HAVE_ARCH_KASAN_VMALLOC 162 select HAVE_ARCH_KASAN_SW_TAGS 163 select HAVE_ARCH_KASAN_HW_TAGS if 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_KSTACK_ERASE 169 select HAVE_ARCH_MMAP_RND_BITS 170 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 171 select HAVE_ARCH_PREL32_RELOCATIONS 172 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 173 select HAVE_ARCH_SECCOMP_FILTER 174 select HAVE_ARCH_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_ARGS \ 189 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 190 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 191 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 192 if DYNAMIC_FTRACE_WITH_ARGS 193 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 194 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ 195 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 196 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 197 if DYNAMIC_FTRACE_WITH_ARGS 198 select HAVE_SAMPLE_FTRACE_DIRECT 199 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 200 select HAVE_SHARED_GPIOS 201 select HAVE_BUILDTIME_MCOUNT_SORT 202 select HAVE_EFFICIENT_UNALIGNED_ACCESS 203 select HAVE_GUP_FAST 204 select HAVE_FTRACE_GRAPH_FUNC 205 select HAVE_FUNCTION_TRACER 206 select HAVE_FUNCTION_ERROR_INJECTION 207 select HAVE_FUNCTION_GRAPH_FREGS 208 select HAVE_FUNCTION_GRAPH_TRACER 209 select HAVE_GCC_PLUGINS 210 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 211 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 212 select HAVE_HW_BREAKPOINT if PERF_EVENTS 213 select HAVE_IOREMAP_PROT 214 select HAVE_IRQ_TIME_ACCOUNTING 215 select HAVE_LIVEPATCH 216 select HAVE_MOD_ARCH_SPECIFIC 217 select HAVE_NMI 218 select HAVE_PERF_EVENTS 219 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 220 select HAVE_PERF_REGS 221 select HAVE_PERF_USER_STACK_DUMP 222 select HAVE_REGS_AND_STACK_ACCESS_API 223 select HAVE_RELIABLE_STACKTRACE 224 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 225 select HAVE_FUNCTION_ARG_ACCESS_API 226 select MMU_GATHER_RCU_TABLE_FREE 227 select HAVE_RSEQ 228 select HAVE_RUST 229 select HAVE_STACKPROTECTOR 230 select HAVE_STATIC_CALL if CFI 231 select HAVE_SYSCALL_TRACEPOINTS 232 select HAVE_KPROBES 233 select HAVE_KRETPROBES 234 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 235 select HOTPLUG_SMT if HOTPLUG_CPU 236 select IRQ_DOMAIN 237 select IRQ_FORCED_THREADING 238 select JUMP_LABEL 239 select KASAN_VMALLOC if KASAN 240 select LOCK_MM_AND_FIND_VMA 241 select MODULES_USE_ELF_RELA 242 select NEED_DMA_MAP_STATE 243 select NEED_SG_DMA_LENGTH 244 select OF 245 select OF_EARLY_FLATTREE 246 select PCI_DOMAINS_GENERIC if PCI 247 select PCI_ECAM if (ACPI && PCI) 248 select PCI_SYSCALL if PCI 249 select POWER_RESET 250 select POWER_SUPPLY 251 select HAS_SEPARATE_PREEMPT_RESCHED_BITS 252 select SPARSE_IRQ 253 select SWIOTLB 254 select SYSCTL_EXCEPTION_TRACE 255 select THREAD_INFO_IN_TASK 256 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 257 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 258 select TRACE_IRQFLAGS_SUPPORT 259 select TRACE_IRQFLAGS_NMI_SUPPORT 260 select HAVE_SOFTIRQ_ON_OWN_STACK 261 select USER_STACKTRACE_SUPPORT 262 select VDSO_GETRANDOM 263 select VMAP_STACK 264 help 265 ARM 64-bit (AArch64) Linux support. 266 267config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 268 def_bool CC_IS_CLANG 269 # https://github.com/ClangBuiltLinux/linux/issues/1507 270 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 271 272config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 273 def_bool CC_IS_GCC 274 depends on $(cc-option,-fpatchable-function-entry=2) 275 276config 64BIT 277 def_bool y 278 279config MMU 280 def_bool y 281 282config ARM64_CONT_PTE_SHIFT 283 int 284 default 5 if PAGE_SIZE_64KB 285 default 7 if PAGE_SIZE_16KB 286 default 4 287 288config ARM64_CONT_PMD_SHIFT 289 int 290 default 5 if PAGE_SIZE_64KB 291 default 5 if PAGE_SIZE_16KB 292 default 4 293 294config ARCH_MMAP_RND_BITS_MIN 295 default 14 if PAGE_SIZE_64KB 296 default 16 if PAGE_SIZE_16KB 297 default 18 298 299# max bits determined by the following formula: 300# VA_BITS - PTDESC_TABLE_SHIFT 301config ARCH_MMAP_RND_BITS_MAX 302 default 19 if ARM64_VA_BITS=36 303 default 24 if ARM64_VA_BITS=39 304 default 27 if ARM64_VA_BITS=42 305 default 30 if ARM64_VA_BITS=47 306 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 307 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 308 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 309 default 14 if ARM64_64K_PAGES 310 default 16 if ARM64_16K_PAGES 311 default 18 312 313# default to 1 TiB (5 bits below ARCH_MMAP_RND_BITS_MAX) on 48-bit and 314# 52-bit VA; smaller VA sizes fall back to ARCH_MMAP_RND_BITS_MIN in 315# arch/Kconfig 316config ARCH_MMAP_RND_BITS 317 default 24 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 318 default 26 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 319 default 28 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 320 321config ARCH_MMAP_RND_COMPAT_BITS_MIN 322 default 7 if ARM64_64K_PAGES 323 default 9 if ARM64_16K_PAGES 324 default 11 325 326config ARCH_MMAP_RND_COMPAT_BITS_MAX 327 default 16 328 329config NO_IOPORT_MAP 330 def_bool y if !PCI 331 332config STACKTRACE_SUPPORT 333 def_bool y 334 335config ILLEGAL_POINTER_VALUE 336 hex 337 default 0xdead000000000000 338 339config LOCKDEP_SUPPORT 340 def_bool y 341 342config GENERIC_BUG 343 def_bool y 344 depends on BUG 345 346config GENERIC_BUG_RELATIVE_POINTERS 347 def_bool y 348 depends on GENERIC_BUG 349 350config GENERIC_HWEIGHT 351 def_bool y 352 353config GENERIC_CSUM 354 def_bool y 355 356config GENERIC_CALIBRATE_DELAY 357 def_bool y 358 359config SMP 360 def_bool y 361 362config KERNEL_MODE_NEON 363 def_bool y 364 365config FIX_EARLYCON_MEM 366 def_bool y 367 368config PGTABLE_LEVELS 369 int 370 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 371 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 372 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 373 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 374 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 375 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 376 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 377 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 378 379config ARCH_SUPPORTS_UPROBES 380 def_bool y 381 382config ARCH_PROC_KCORE_TEXT 383 def_bool y 384 385config BROKEN_GAS_INST 386 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 387 388config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 389 bool 390 # Clang's __builtin_return_address() strips the PAC since 12.0.0 391 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 392 default y if CC_IS_CLANG 393 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 394 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 395 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 396 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 397 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 398 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 399 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 400 default n 401 402config KASAN_SHADOW_OFFSET 403 hex 404 depends on KASAN_GENERIC || KASAN_SW_TAGS 405 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 406 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 407 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 408 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 409 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 410 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 411 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 412 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 413 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 414 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 415 default 0xffffffffffffffff 416 417config UNWIND_TABLES 418 bool 419 420source "arch/arm64/Kconfig.platforms" 421 422menu "Kernel Features" 423 424menu "ARM errata workarounds via the alternatives framework" 425 426config AMPERE_ERRATUM_AC03_CPU_38 427 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 428 default y 429 help 430 This option adds an alternative code sequence to work around Ampere 431 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 432 433 The affected design reports FEAT_HAFDBS as not implemented in 434 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 435 as required by the architecture. The unadvertised HAFDBS 436 implementation suffers from an additional erratum where hardware 437 A/D updates can occur after a PTE has been marked invalid. 438 439 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 440 which avoids enabling unadvertised hardware Access Flag management 441 at stage-2. 442 443 If unsure, say Y. 444 445config AMPERE_ERRATUM_AC04_CPU_23 446 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 447 default y 448 help 449 This option adds an alternative code sequence to work around Ampere 450 errata AC04_CPU_23 on AmpereOne. 451 452 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 453 data addresses initiated by load/store instructions. Only 454 instruction initiated translations are vulnerable, not translations 455 from prefetches for example. A DSB before the store to HCR_EL2 is 456 sufficient to prevent older instructions from hitting the window 457 for corruption, and an ISB after is sufficient to prevent younger 458 instructions from hitting the window for corruption. 459 460 If unsure, say Y. 461 462config ARM64_WORKAROUND_CLEAN_CACHE 463 bool 464 465config ARM64_ERRATUM_826319 466 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 467 default y 468 select ARM64_WORKAROUND_CLEAN_CACHE 469 help 470 This option adds an alternative code sequence to work around ARM 471 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 472 AXI master interface and an L2 cache. 473 474 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 475 and is unable to accept a certain write via this interface, it will 476 not progress on read data presented on the read data channel and the 477 system can deadlock. 478 479 The workaround promotes data cache clean instructions to 480 data cache clean-and-invalidate. 481 Please note that this does not necessarily enable the workaround, 482 as it depends on the alternative framework, which will only patch 483 the kernel if an affected CPU is detected. 484 485 If unsure, say Y. 486 487config ARM64_ERRATUM_827319 488 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 489 default y 490 select ARM64_WORKAROUND_CLEAN_CACHE 491 help 492 This option adds an alternative code sequence to work around ARM 493 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 494 master interface and an L2 cache. 495 496 Under certain conditions this erratum can cause a clean line eviction 497 to occur at the same time as another transaction to the same address 498 on the AMBA 5 CHI interface, which can cause data corruption if the 499 interconnect reorders the two transactions. 500 501 The workaround promotes data cache clean instructions to 502 data cache clean-and-invalidate. 503 Please note that this does not necessarily enable the workaround, 504 as it depends on the alternative framework, which will only patch 505 the kernel if an affected CPU is detected. 506 507 If unsure, say Y. 508 509config ARM64_ERRATUM_824069 510 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 511 default y 512 select ARM64_WORKAROUND_CLEAN_CACHE 513 help 514 This option adds an alternative code sequence to work around ARM 515 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 516 to a coherent interconnect. 517 518 If a Cortex-A53 processor is executing a store or prefetch for 519 write instruction at the same time as a processor in another 520 cluster is executing a cache maintenance operation to the same 521 address, then this erratum might cause a clean cache line to be 522 incorrectly marked as dirty. 523 524 The workaround promotes data cache clean instructions to 525 data cache clean-and-invalidate. 526 Please note that this option does not necessarily enable the 527 workaround, as it depends on the alternative framework, which will 528 only patch the kernel if an affected CPU is detected. 529 530 If unsure, say Y. 531 532config ARM64_ERRATUM_819472 533 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 534 default y 535 select ARM64_WORKAROUND_CLEAN_CACHE 536 help 537 This option adds an alternative code sequence to work around ARM 538 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 539 present when it is connected to a coherent interconnect. 540 541 If the processor is executing a load and store exclusive sequence at 542 the same time as a processor in another cluster is executing a cache 543 maintenance operation to the same address, then this erratum might 544 cause data corruption. 545 546 The workaround promotes data cache clean instructions to 547 data cache clean-and-invalidate. 548 Please note that this does not necessarily enable the workaround, 549 as it depends on the alternative framework, which will only patch 550 the kernel if an affected CPU is detected. 551 552 If unsure, say Y. 553 554config ARM64_ERRATUM_832075 555 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 556 default y 557 help 558 This option adds an alternative code sequence to work around ARM 559 erratum 832075 on Cortex-A57 parts up to r1p2. 560 561 Affected Cortex-A57 parts might deadlock when exclusive load/store 562 instructions to Write-Back memory are mixed with Device loads. 563 564 The workaround is to promote device loads to use Load-Acquire 565 semantics. 566 Please note that this does not necessarily enable the workaround, 567 as it depends on the alternative framework, which will only patch 568 the kernel if an affected CPU is detected. 569 570 If unsure, say Y. 571 572config ARM64_ERRATUM_834220 573 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 574 depends on KVM 575 help 576 This option adds an alternative code sequence to work around ARM 577 erratum 834220 on Cortex-A57 parts up to r1p2. 578 579 Affected Cortex-A57 parts might report a Stage 2 translation 580 fault as the result of a Stage 1 fault for load crossing a 581 page boundary when there is a permission or device memory 582 alignment fault at Stage 1 and a translation fault at Stage 2. 583 584 The workaround is to verify that the Stage 1 translation 585 doesn't generate a fault before handling the Stage 2 fault. 586 Please note that this does not necessarily enable the workaround, 587 as it depends on the alternative framework, which will only patch 588 the kernel if an affected CPU is detected. 589 590 If unsure, say N. 591 592config ARM64_ERRATUM_1742098 593 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 594 depends on COMPAT 595 default y 596 help 597 This option removes the AES hwcap for aarch32 user-space to 598 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 599 600 Affected parts may corrupt the AES state if an interrupt is 601 taken between a pair of AES instructions. These instructions 602 are only present if the cryptography extensions are present. 603 All software should have a fallback implementation for CPUs 604 that don't implement the cryptography extensions. 605 606 If unsure, say Y. 607 608config ARM64_ERRATUM_845719 609 bool "Cortex-A53: 845719: a load might read incorrect data" 610 depends on COMPAT 611 default y 612 help 613 This option adds an alternative code sequence to work around ARM 614 erratum 845719 on Cortex-A53 parts up to r0p4. 615 616 When running a compat (AArch32) userspace on an affected Cortex-A53 617 part, a load at EL0 from a virtual address that matches the bottom 32 618 bits of the virtual address used by a recent load at (AArch64) EL1 619 might return incorrect data. 620 621 The workaround is to write the contextidr_el1 register on exception 622 return to a 32-bit task. 623 Please note that this does not necessarily enable the workaround, 624 as it depends on the alternative framework, which will only patch 625 the kernel if an affected CPU is detected. 626 627 If unsure, say Y. 628 629config ARM64_ERRATUM_843419 630 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 631 default y 632 help 633 This option links the kernel with '--fix-cortex-a53-843419' and 634 enables PLT support to replace certain ADRP instructions, which can 635 cause subsequent memory accesses to use an incorrect address on 636 Cortex-A53 parts up to r0p4. 637 638 If unsure, say Y. 639 640config ARM64_ERRATUM_1024718 641 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 642 default y 643 help 644 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 645 646 Affected Cortex-A55 cores (all revisions) could cause incorrect 647 update of the hardware dirty bit when the DBM/AP bits are updated 648 without a break-before-make. The workaround is to disable the usage 649 of hardware DBM locally on the affected cores. CPUs not affected by 650 this erratum will continue to use the feature. 651 652 If unsure, say Y. 653 654config ARM64_ERRATUM_1418040 655 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 656 default y 657 depends on COMPAT 658 help 659 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 660 errata 1188873 and 1418040. 661 662 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 663 cause register corruption when accessing the timer registers 664 from AArch32 userspace. 665 666 If unsure, say Y. 667 668config ARM64_WORKAROUND_SPECULATIVE_AT 669 bool 670 671config ARM64_ERRATUM_1165522 672 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 673 default y 674 select ARM64_WORKAROUND_SPECULATIVE_AT 675 help 676 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 677 678 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 679 corrupted TLBs by speculating an AT instruction during a guest 680 context switch. 681 682 If unsure, say Y. 683 684config ARM64_ERRATUM_1319367 685 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 686 default y 687 select ARM64_WORKAROUND_SPECULATIVE_AT 688 help 689 This option adds work arounds for ARM Cortex-A57 erratum 1319537 690 and A72 erratum 1319367 691 692 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 693 speculating an AT instruction during a guest context switch. 694 695 If unsure, say Y. 696 697config ARM64_ERRATUM_1530923 698 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 699 default y 700 select ARM64_WORKAROUND_SPECULATIVE_AT 701 help 702 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 703 704 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 705 corrupted TLBs by speculating an AT instruction during a guest 706 context switch. 707 708 If unsure, say Y. 709 710config ARM64_WORKAROUND_REPEAT_TLBI_SYNC 711 bool 712 # This workaround is (only) suitable for TLB invalidation errata where 713 # all of the following conditions are true: 714 # 715 # - The effects of the errata are only a loss of ordering/completion 716 # for explicit memory accesses when the TLBI is completed with a DSB. 717 # The removal of TLB entries is not affected. 718 # 719 # Note that architecturally, S2-only invalidation does not remove 720 # combined S1+S2 entries, and does not complete accesses translated 721 # via those S1+S2 entries. Consequently, where this condition holds, 722 # the errata do not affect S2-only invalidation. 723 # 724 # - The errata only affect broadcast TLB invalidation operations (e.g. 725 # TLBI VMALLE1IS), and do not affect local TLB invalidation 726 # operations (e.g. TLBI VMALLE1). 727 # 728 # - After any number of affected TLBI operations are completed with a 729 # DSB, the errata can be mitigated by executing a single arbitrary 730 # broadcast TLBI (which targets an arbitrary translation regime), 731 # followed by a DSB. 732 # 733 # For more rationale, see commit a8f78680ee6bf795. 734 735config ARM64_ERRATUM_2441007 736 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 737 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 738 help 739 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 740 741 Under very rare circumstances, affected Cortex-A55 CPUs 742 may not handle a race between a break-before-make sequence on one 743 CPU, and another CPU accessing the same page. This could allow a 744 store to a page that has been unmapped. 745 746 Work around this by adding the affected CPUs to the list that needs 747 TLB sequences to be done twice. 748 749 If unsure, say N. 750 751config ARM64_ERRATUM_1286807 752 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 753 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 754 help 755 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 756 757 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 758 address for a cacheable mapping of a location is being 759 accessed by a core while another core is remapping the virtual 760 address to a new physical page using the recommended 761 break-before-make sequence, then under very rare circumstances 762 TLBI+DSB completes before a read using the translation being 763 invalidated has been observed by other observers. The 764 workaround repeats the TLBI+DSB operation. 765 766 If unsure, say N. 767 768config ARM64_ERRATUM_1463225 769 bool "Cortex-A76: Software Step might prevent interrupt recognition" 770 default y 771 help 772 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 773 774 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 775 of a system call instruction (SVC) can prevent recognition of 776 subsequent interrupts when software stepping is disabled in the 777 exception handler of the system call and either kernel debugging 778 is enabled or VHE is in use. 779 780 Work around the erratum by triggering a dummy step exception 781 when handling a system call from a task that is being stepped 782 in a VHE configuration of the kernel. 783 784 If unsure, say Y. 785 786config ARM64_ERRATUM_1542419 787 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 788 help 789 This option adds a workaround for ARM Neoverse-N1 erratum 790 1542419. 791 792 Affected Neoverse-N1 cores could execute a stale instruction when 793 modified by another CPU. The workaround depends on a firmware 794 counterpart. 795 796 Workaround the issue by hiding the DIC feature from EL0. This 797 forces user-space to perform cache maintenance. 798 799 If unsure, say N. 800 801config ARM64_ERRATUM_1508412 802 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 803 default y 804 help 805 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 806 807 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 808 of a store-exclusive or read of PAR_EL1 and a load with device or 809 non-cacheable memory attributes. The workaround depends on a firmware 810 counterpart. 811 812 KVM guests must also have the workaround implemented or they can 813 deadlock the system. 814 815 Work around the issue by inserting DMB SY barriers around PAR_EL1 816 register reads and warning KVM users. The DMB barrier is sufficient 817 to prevent a speculative PAR_EL1 read. 818 819 If unsure, say Y. 820 821config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 822 bool 823 824config ARM64_ERRATUM_2051678 825 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 826 default y 827 help 828 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 829 Affected Cortex-A510 might not respect the ordering rules for 830 hardware update of the page table's dirty bit. The workaround 831 is to not enable the feature on affected CPUs. 832 833 If unsure, say Y. 834 835config ARM64_ERRATUM_2077057 836 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 837 default y 838 help 839 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 840 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 841 expected, but a Pointer Authentication trap is taken instead. The 842 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 843 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 844 845 This can only happen when EL2 is stepping EL1. 846 847 When these conditions occur, the SPSR_EL2 value is unchanged from the 848 previous guest entry, and can be restored from the in-memory copy. 849 850 If unsure, say Y. 851 852config ARM64_ERRATUM_2658417 853 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 854 default y 855 help 856 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 857 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 858 BFMMLA or VMMLA instructions in rare circumstances when a pair of 859 A510 CPUs are using shared neon hardware. As the sharing is not 860 discoverable by the kernel, hide the BF16 HWCAP to indicate that 861 user-space should not be using these instructions. 862 863 If unsure, say Y. 864 865config ARM64_ERRATUM_2119858 866 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 867 default y 868 depends on CORESIGHT_TRBE 869 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 870 help 871 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 872 873 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 874 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 875 the event of a WRAP event. 876 877 Work around the issue by always making sure we move the TRBPTR_EL1 by 878 256 bytes before enabling the buffer and filling the first 256 bytes of 879 the buffer with ETM ignore packets upon disabling. 880 881 If unsure, say Y. 882 883config ARM64_ERRATUM_2139208 884 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 885 default y 886 depends on CORESIGHT_TRBE 887 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 888 help 889 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 890 891 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 892 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 893 the event of a WRAP event. 894 895 Work around the issue by always making sure we move the TRBPTR_EL1 by 896 256 bytes before enabling the buffer and filling the first 256 bytes of 897 the buffer with ETM ignore packets upon disabling. 898 899 If unsure, say Y. 900 901config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 902 bool 903 904config ARM64_ERRATUM_2054223 905 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 906 default y 907 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 908 help 909 Enable workaround for ARM Cortex-A710 erratum 2054223 910 911 Affected cores may fail to flush the trace data on a TSB instruction, when 912 the PE is in trace prohibited state. This will cause losing a few bytes 913 of the trace cached. 914 915 Workaround is to issue two TSB consecutively on affected cores. 916 917 If unsure, say Y. 918 919config ARM64_ERRATUM_2067961 920 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 921 default y 922 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 923 help 924 Enable workaround for ARM Neoverse-N2 erratum 2067961 925 926 Affected cores may fail to flush the trace data on a TSB instruction, when 927 the PE is in trace prohibited state. This will cause losing a few bytes 928 of the trace cached. 929 930 Workaround is to issue two TSB consecutively on affected cores. 931 932 If unsure, say Y. 933 934config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 935 bool 936 937config ARM64_ERRATUM_2253138 938 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 939 depends on CORESIGHT_TRBE 940 default y 941 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 942 help 943 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 944 945 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 946 for TRBE. Under some conditions, the TRBE might generate a write to the next 947 virtually addressed page following the last page of the TRBE address space 948 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 949 950 Work around this in the driver by always making sure that there is a 951 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 952 953 If unsure, say Y. 954 955config ARM64_ERRATUM_2224489 956 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 957 depends on CORESIGHT_TRBE 958 default y 959 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 960 help 961 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 962 963 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 964 for TRBE. Under some conditions, the TRBE might generate a write to the next 965 virtually addressed page following the last page of the TRBE address space 966 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 967 968 Work around this in the driver by always making sure that there is a 969 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 970 971 If unsure, say Y. 972 973config ARM64_ERRATUM_2441009 974 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 975 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 976 help 977 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 978 979 Under very rare circumstances, affected Cortex-A510 CPUs 980 may not handle a race between a break-before-make sequence on one 981 CPU, and another CPU accessing the same page. This could allow a 982 store to a page that has been unmapped. 983 984 Work around this by adding the affected CPUs to the list that needs 985 TLB sequences to be done twice. 986 987 If unsure, say N. 988 989config ARM64_ERRATUM_2064142 990 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 991 depends on CORESIGHT_TRBE 992 default y 993 help 994 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 995 996 Affected Cortex-A510 core might fail to write into system registers after the 997 TRBE has been disabled. Under some conditions after the TRBE has been disabled 998 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 999 and TRBTRG_EL1 will be ignored and will not be effected. 1000 1001 Work around this in the driver by executing TSB CSYNC and DSB after collection 1002 is stopped and before performing a system register write to one of the affected 1003 registers. 1004 1005 If unsure, say Y. 1006 1007config ARM64_ERRATUM_2038923 1008 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1009 depends on CORESIGHT_TRBE 1010 default y 1011 help 1012 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1013 1014 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1015 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1016 might be corrupted. This happens after TRBE buffer has been enabled by setting 1017 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1018 execution changes from a context, in which trace is prohibited to one where it 1019 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1020 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1021 the trace buffer state might be corrupted. 1022 1023 Work around this in the driver by preventing an inconsistent view of whether the 1024 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1025 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1026 two ISB instructions if no ERET is to take place. 1027 1028 If unsure, say Y. 1029 1030config ARM64_ERRATUM_1902691 1031 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1032 depends on CORESIGHT_TRBE 1033 default y 1034 help 1035 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1036 1037 Affected Cortex-A510 core might cause trace data corruption, when being written 1038 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1039 trace data. 1040 1041 Work around this problem in the driver by just preventing TRBE initialization on 1042 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1043 on such implementations. This will cover the kernel for any firmware that doesn't 1044 do this already. 1045 1046 If unsure, say Y. 1047 1048config ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT 1049 bool 1050 # Targeting errata affecting AMEVCNTR01, the AMU constant counter. 1051 # On affected CPUs the counter may not increment at the expected rate, 1052 # making it unreliable. As a result, AMU users should treat it as 1053 # unavailable rather than relying on misleading counter values. 1054 1055config ARM64_ERRATUM_2457168 1056 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1057 depends on ARM64_AMU_EXTN 1058 select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT 1059 default y 1060 help 1061 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1062 1063 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1064 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1065 incorrectly giving a significantly higher output value. 1066 1067 Work around this problem by returning 0 when reading the affected counter in 1068 key locations that results in disabling all users of this counter. This effect 1069 is the same to firmware disabling affected counters. 1070 1071 If unsure, say Y. 1072 1073config ARM64_ERRATUM_2645198 1074 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1075 default y 1076 help 1077 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1078 1079 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1080 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1081 next instruction abort caused by permission fault. 1082 1083 Only user-space does executable to non-executable permission transition via 1084 mprotect() system call. Workaround the problem by doing a break-before-make 1085 TLB invalidation, for all changes to executable user space mappings. 1086 1087 If unsure, say Y. 1088 1089config ARM64_ERRATUM_3821522 1090 bool "Cortex-A725: 3821522: workaround for possible CNT_CYCLES increment error due to WFE/WFI" 1091 depends on ARM64_AMU_EXTN 1092 select ARM64_WORKAROUND_BROKEN_AMU_CONSTCNT 1093 default y 1094 help 1095 This option adds the workaround for ARM Cortex-A725 erratum 3821522. 1096 1097 On affected A725 cores, the CNT_CYCLES event may incur a significant 1098 increment error when entering and subsequently exiting WFx. 1099 As a result, the CNT_CYCLES may diverge from the system counter 1100 frequency at which it is expected to increment. 1101 This renders the AMU counter AMEVCNTR01, that implements CNT_CYCLES, 1102 being unreliable and unsuitable for use. 1103 1104 Since there is no hardware workaround, reads of the affected CNT_CYCLES 1105 counter return 0 in the relevant paths. This causes users of the counter 1106 to treat it as unavailable and is functionally equivalent to firmware 1107 disabling the affected counter. 1108 1109 If unsure, say Y. 1110 1111config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1112 bool 1113 1114config ARM64_ERRATUM_2966298 1115 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1116 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1117 default y 1118 help 1119 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1120 1121 On an affected Cortex-A520 core, a speculatively executed unprivileged 1122 load might leak data from a privileged level via a cache side channel. 1123 1124 Work around this problem by executing a TLBI before returning to EL0. 1125 1126 If unsure, say Y. 1127 1128config ARM64_ERRATUM_3117295 1129 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1130 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1131 default y 1132 help 1133 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1134 1135 On an affected Cortex-A510 core, a speculatively executed unprivileged 1136 load might leak data from a privileged level via a cache side channel. 1137 1138 Work around this problem by executing a TLBI before returning to EL0. 1139 1140 If unsure, say Y. 1141 1142config ARM64_ERRATUM_3194386 1143 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1144 default y 1145 help 1146 This option adds the workaround for the following errata: 1147 1148 * ARM Cortex-A76 erratum 3324349 1149 * ARM Cortex-A77 erratum 3324348 1150 * ARM Cortex-A78 erratum 3324344 1151 * ARM Cortex-A78C erratum 3324346 1152 * ARM Cortex-A78C erratum 3324347 1153 * ARM Cortex-A710 erratam 3324338 1154 * ARM Cortex-A715 errartum 3456084 1155 * ARM Cortex-A720 erratum 3456091 1156 * ARM Cortex-A725 erratum 3456106 1157 * ARM Cortex-X1 erratum 3324344 1158 * ARM Cortex-X1C erratum 3324346 1159 * ARM Cortex-X2 erratum 3324338 1160 * ARM Cortex-X3 erratum 3324335 1161 * ARM Cortex-X4 erratum 3194386 1162 * ARM Cortex-X925 erratum 3324334 1163 * ARM Neoverse-N1 erratum 3324349 1164 * ARM Neoverse N2 erratum 3324339 1165 * ARM Neoverse-N3 erratum 3456111 1166 * ARM Neoverse-V1 erratum 3324341 1167 * ARM Neoverse V2 erratum 3324336 1168 * ARM Neoverse-V3 erratum 3312417 1169 * ARM Neoverse-V3AE erratum 3312417 1170 1171 On affected cores "MSR SSBS, #0" instructions may not affect 1172 subsequent speculative instructions, which may permit unexepected 1173 speculative store bypassing. 1174 1175 Work around this problem by placing a Speculation Barrier (SB) or 1176 Instruction Synchronization Barrier (ISB) after kernel changes to 1177 SSBS. The presence of the SSBS special-purpose register is hidden 1178 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1179 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1180 1181 If unsure, say Y. 1182 1183config ARM64_ERRATUM_4311569 1184 bool "SI L1: 4311569: workaround for premature CMO completion erratum" 1185 default y 1186 help 1187 This option adds the workaround for ARM SI L1 erratum 4311569. 1188 1189 The erratum of SI L1 can cause an early response to a combined write 1190 and cache maintenance operation (WR+CMO) before the operation is fully 1191 completed to the Point of Serialization (POS). 1192 This can result in a non-I/O coherent agent observing stale data, 1193 potentially leading to system instability or incorrect behavior. 1194 1195 Enabling this option implements a software workaround by inserting a 1196 second loop of Cache Maintenance Operation (CMO) immediately following the 1197 end of function to do CMOs. This ensures that the data is correctly serialized 1198 before the buffer is handed off to a non-coherent agent. 1199 1200 If unsure, say Y. 1201 1202config ARM64_ERRATUM_4193714 1203 bool "C1-Pro: 4193714: SME DVMSync early acknowledgement" 1204 depends on ARM64_SME 1205 default y 1206 help 1207 Enable workaround for C1-Pro acknowledging the DVMSync before 1208 the SME memory accesses are complete. This will cause TLB 1209 maintenance for processes using SME to also issue an IPI to 1210 the affected CPUs. 1211 1212 If unsure, say Y. 1213 1214config ARM64_ERRATUM_4118414 1215 bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 1216 default y 1217 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 1218 help 1219 This option adds a workaround for the following errata: 1220 1221 * ARM C1-Premium erratum 4193780 1222 * ARM C1-Ultra erratum 4193780 1223 * ARM Cortex-A76 erratum 4193800 1224 * ARM Cortex-A76AE erratum 4193801 1225 * ARM Cortex-A77 erratum 4193798 1226 * ARM Cortex-A78 erratum 4193791 1227 * ARM Cortex-A78AE erratum 4193793 1228 * ARM Cortex-A78C erratum 4193794 1229 * ARM Cortex-A710 erratum 4193788 1230 * ARM Cortex-X1 erratum 4193791 1231 * ARM Cortex-X1C erratum 4193792 1232 * ARM Cortex-X2 erratum 4193788 1233 * ARM Cortex-X3 erratum 4193786 1234 * ARM Cortex-X4 erratum 4118414 1235 * ARM Cortex-X925 erratum 4193781 1236 * ARM Neoverse-N1 erratum 4193800 1237 * ARM Neoverse-N2 erratum 4193789 1238 * ARM Neoverse-V1 erratum 4193790 1239 * ARM Neoverse-V2 erratum 4193787 1240 * ARM Neoverse-V3 erratum 4193784 1241 * ARM Neoverse-V3AE erratum 4193784 1242 * Microsoft Azure Cobalt 100 4193789 1243 * NVIDIA Olympus erratum T410-OLY-1029 1244 1245 On affected cores, some memory accesses might not be completed by 1246 broadcast TLB invalidation. 1247 1248 This issue is also known as CVE-2025-10263. 1249 1250 If unsure, say Y. 1251 1252config CAVIUM_ERRATUM_22375 1253 bool "Cavium erratum 22375, 24313" 1254 default y 1255 help 1256 Enable workaround for errata 22375 and 24313. 1257 1258 This implements two gicv3-its errata workarounds for ThunderX. Both 1259 with a small impact affecting only ITS table allocation. 1260 1261 erratum 22375: only alloc 8MB table size 1262 erratum 24313: ignore memory access type 1263 1264 The fixes are in ITS initialization and basically ignore memory access 1265 type and table size provided by the TYPER and BASER registers. 1266 1267 If unsure, say Y. 1268 1269config CAVIUM_ERRATUM_23144 1270 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1271 depends on NUMA 1272 default y 1273 help 1274 ITS SYNC command hang for cross node io and collections/cpu mapping. 1275 1276 If unsure, say Y. 1277 1278config CAVIUM_ERRATUM_23154 1279 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1280 default y 1281 help 1282 The ThunderX GICv3 implementation requires a modified version for 1283 reading the IAR status to ensure data synchronization 1284 (access to icc_iar1_el1 is not sync'ed before and after). 1285 1286 It also suffers from erratum 38545 (also present on Marvell's 1287 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1288 spuriously presented to the CPU interface. 1289 1290 If unsure, say Y. 1291 1292config CAVIUM_ERRATUM_27456 1293 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1294 default y 1295 help 1296 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1297 instructions may cause the icache to become corrupted if it 1298 contains data for a non-current ASID. The fix is to 1299 invalidate the icache when changing the mm context. 1300 1301 If unsure, say Y. 1302 1303config CAVIUM_ERRATUM_30115 1304 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1305 default y 1306 help 1307 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1308 1.2, and T83 Pass 1.0, KVM guest execution may disable 1309 interrupts in host. Trapping both GICv3 group-0 and group-1 1310 accesses sidesteps the issue. 1311 1312 If unsure, say Y. 1313 1314config CAVIUM_TX2_ERRATUM_219 1315 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1316 default y 1317 help 1318 On Cavium ThunderX2, a load, store or prefetch instruction between a 1319 TTBR update and the corresponding context synchronizing operation can 1320 cause a spurious Data Abort to be delivered to any hardware thread in 1321 the CPU core. 1322 1323 Work around the issue by avoiding the problematic code sequence and 1324 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1325 trap handler performs the corresponding register access, skips the 1326 instruction and ensures context synchronization by virtue of the 1327 exception return. 1328 1329 If unsure, say Y. 1330 1331config FUJITSU_ERRATUM_010001 1332 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1333 default y 1334 help 1335 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1336 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1337 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1338 This fault occurs under a specific hardware condition when a 1339 load/store instruction performs an address translation using: 1340 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1341 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1342 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1343 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1344 1345 The workaround is to ensure these bits are clear in TCR_ELx. 1346 The workaround only affects the Fujitsu-A64FX. 1347 1348 If unsure, say Y. 1349 1350config HISILICON_ERRATUM_161600802 1351 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1352 default y 1353 help 1354 The HiSilicon Hip07 SoC uses the wrong redistributor base 1355 when issued ITS commands such as VMOVP and VMAPP, and requires 1356 a 128kB offset to be applied to the target address in this commands. 1357 1358 If unsure, say Y. 1359 1360config HISILICON_ERRATUM_162100801 1361 bool "Hip09 162100801 erratum support" 1362 default y 1363 help 1364 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1365 during unmapping operation, which will cause some vSGIs lost. 1366 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1367 after VMOVP. 1368 1369 If unsure, say Y. 1370 1371config HISILICON_ERRATUM_162100125 1372 bool "Hisilicon erratum 162100125" 1373 default y 1374 select ARM64_WORKAROUND_DISABLE_CNP 1375 help 1376 On HiSilicon HIP09, TLB entry matching behavior when CNP 1377 (TTBRx.CNP=1) is enabled differs from the ARM architecture 1378 specification. 1379 1380 TLB entries may be incorrectly shared between CPUs, potentially 1381 causing TLB conflicts and stale mappings. 1382 1383 Disable CNP support for affected HiSilicon HIP09 cores. 1384 1385 If unsure, say Y. 1386 1387config QCOM_FALKOR_ERRATUM_1003 1388 bool "Falkor E1003: Incorrect translation due to ASID change" 1389 default y 1390 help 1391 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1392 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1393 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1394 then only for entries in the walk cache, since the leaf translation 1395 is unchanged. Work around the erratum by invalidating the walk cache 1396 entries for the trampoline before entering the kernel proper. 1397 1398config QCOM_FALKOR_ERRATUM_1009 1399 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1400 default y 1401 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 1402 help 1403 On Falkor v1, the CPU may prematurely complete a DSB following a 1404 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1405 one more time to fix the issue. 1406 1407 If unsure, say Y. 1408 1409config QCOM_QDF2400_ERRATUM_0065 1410 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1411 default y 1412 help 1413 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1414 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1415 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1416 1417 If unsure, say Y. 1418 1419config QCOM_FALKOR_ERRATUM_E1041 1420 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1421 default y 1422 help 1423 Falkor CPU may speculatively fetch instructions from an improper 1424 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1425 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1426 1427 If unsure, say Y. 1428 1429config ARM64_WORKAROUND_DISABLE_CNP 1430 bool 1431 1432config NVIDIA_CARMEL_CNP_ERRATUM 1433 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1434 default y 1435 select ARM64_WORKAROUND_DISABLE_CNP 1436 help 1437 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1438 invalidate shared TLB entries installed by a different core, as it would 1439 on standard ARM cores. 1440 1441 If unsure, say Y. 1442 1443config NVIDIA_OLYMPUS_1027_ERRATUM 1444 bool "NVIDIA Olympus: device store/load ordering erratum" 1445 default y 1446 help 1447 This option adds an alternative code sequence to work around an 1448 NVIDIA Olympus core erratum where a Device-nGnR* store can be 1449 observed by a peripheral after a younger Device-nGnR* load to the 1450 same peripheral. This breaks the program order that drivers rely 1451 on for MMIO and can leave a device in an incorrect state. 1452 1453 The workaround inserts a DMB OSH immediately before raw MMIO loads. 1454 The erratum cannot occur when a DMB that orders loads appears 1455 between the store and load, preventing the younger load from being 1456 observed before the older store. 1457 1458 The alternatives framework patches in DMB OSH only when an affected 1459 CPU is detected. Other CPUs execute a NOP in its place. Disabling 1460 this option leaves the original MMIO read instruction stream 1461 unchanged. 1462 1463 If unsure, say Y. 1464 1465config ALTERA_ERRATUM_AGILEX5_2_1_23 1466 bool 1467 help 1468 The Altera SoCFPGA Agilex5 GIC600 SoC integration has ACE-lite 1469 addressing limited to the first 32bit of physical address space, 1470 so the ITS cannot access memory above 4GB. 1471 1472 Selected by ARCH_INTEL_SOCFPGA, as all Agilex5 devices are affected. 1473 1474config RENESAS_ERRATUM_GEN4GICITS1 1475 bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB" 1476 default y 1477 help 1478 The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI 1479 addressing limited to the first 32-bit of physical address space. 1480 1481 If unsure, say Y. 1482 1483config ROCKCHIP_ERRATUM_3568002 1484 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1485 default y 1486 help 1487 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1488 addressing limited to the first 32bit of physical address space. 1489 1490 If unsure, say Y. 1491 1492config ROCKCHIP_ERRATUM_3588001 1493 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1494 default y 1495 help 1496 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1497 This means, that its sharability feature may not be used, even though it 1498 is supported by the IP itself. 1499 1500 If unsure, say Y. 1501 1502config NXP_IMX8QM_ERRATUM_ERR050104 1503 bool "NXP iMX8QM/QP ERR050104: broken cache/TLB invalidation broadcast" 1504 default y 1505 help 1506 On iMX8QM (QuadMax) and iMX8QP (QuadPlus), address bits above bit 35 1507 in the A53 subsystem ARADDR and ACADDR buses are incorrectly 1508 connected. This corrupts targeted TLBI and IC broadcasts exchanged 1509 between the A53 and A72 core clusters. 1510 1511 Work around this by redirecting targeted TLBI operations to 1512 broadcast-all variants (VMALLE1IS) in the high-level TLB flush 1513 functions, upgrading IC IVAU to IC IALLUIS for both kernel and 1514 user-space, and disabling KVM since correct TLB maintenance 1515 cannot be guaranteed for guests. 1516 1517 The user-space IC IVAU is upgraded by trapping it to the kernel 1518 (SCTLR_EL1.UCI cleared). This also traps the user DC CVAU, DC CVAC, 1519 DC CVAP, DC CVADP and DC CIVAC instructions, making user cache 1520 maintenance slower on the affected SoCs. 1521 1522 If unsure, say Y. 1523 1524config SOCIONEXT_SYNQUACER_PREITS 1525 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1526 default y 1527 help 1528 Socionext Synquacer SoCs implement a separate h/w block to generate 1529 MSI doorbell writes with non-zero values for the device ID. 1530 1531 If unsure, say Y. 1532 1533endmenu # "ARM errata workarounds via the alternatives framework" 1534 1535choice 1536 prompt "Page size" 1537 default ARM64_4K_PAGES 1538 help 1539 Page size (translation granule) configuration. 1540 1541config ARM64_4K_PAGES 1542 bool "4KB" 1543 select HAVE_PAGE_SIZE_4KB 1544 help 1545 This feature enables 4KB pages support. 1546 1547config ARM64_16K_PAGES 1548 bool "16KB" 1549 select HAVE_PAGE_SIZE_16KB 1550 help 1551 The system will use 16KB pages support. AArch32 emulation 1552 requires applications compiled with 16K (or a multiple of 16K) 1553 aligned segments. 1554 1555config ARM64_64K_PAGES 1556 bool "64KB" 1557 select HAVE_PAGE_SIZE_64KB 1558 help 1559 This feature enables 64KB pages support (4KB by default) 1560 allowing only two levels of page tables and faster TLB 1561 look-up. AArch32 emulation requires applications compiled 1562 with 64K aligned segments. 1563 1564endchoice 1565 1566choice 1567 prompt "Virtual address space size" 1568 default ARM64_VA_BITS_52 1569 help 1570 Allows choosing one of multiple possible virtual address 1571 space sizes. The level of translation table is determined by 1572 a combination of page size and virtual address space size. 1573 1574config ARM64_VA_BITS_36 1575 bool "36-bit" if EXPERT 1576 depends on PAGE_SIZE_16KB 1577 1578config ARM64_VA_BITS_39 1579 bool "39-bit" 1580 depends on PAGE_SIZE_4KB 1581 1582config ARM64_VA_BITS_42 1583 bool "42-bit" 1584 depends on PAGE_SIZE_64KB 1585 1586config ARM64_VA_BITS_47 1587 bool "47-bit" 1588 depends on PAGE_SIZE_16KB 1589 1590config ARM64_VA_BITS_48 1591 bool "48-bit" 1592 1593config ARM64_VA_BITS_52 1594 bool "52-bit" 1595 help 1596 Enable 52-bit virtual addressing for userspace when explicitly 1597 requested via a hint to mmap(). The kernel will also use 52-bit 1598 virtual addresses for its own mappings (provided HW support for 1599 this feature is available, otherwise it reverts to 48-bit). 1600 1601 NOTE: Enabling 52-bit virtual addressing in conjunction with 1602 ARMv8.3 Pointer Authentication will result in the PAC being 1603 reduced from 7 bits to 3 bits, which may have a significant 1604 impact on its susceptibility to brute-force attacks. 1605 1606 If unsure, select 48-bit virtual addressing instead. 1607 1608endchoice 1609 1610config ARM64_FORCE_52BIT 1611 bool "Force 52-bit virtual addresses for userspace" 1612 depends on ARM64_VA_BITS_52 && EXPERT 1613 help 1614 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1615 to maintain compatibility with older software by providing 48-bit VAs 1616 unless a hint is supplied to mmap. 1617 1618 This configuration option disables the 48-bit compatibility logic, and 1619 forces all userspace addresses to be 52-bit on HW that supports it. One 1620 should only enable this configuration option for stress testing userspace 1621 memory management code. If unsure say N here. 1622 1623config ARM64_VA_BITS 1624 int 1625 default 36 if ARM64_VA_BITS_36 1626 default 39 if ARM64_VA_BITS_39 1627 default 42 if ARM64_VA_BITS_42 1628 default 47 if ARM64_VA_BITS_47 1629 default 48 if ARM64_VA_BITS_48 1630 default 52 if ARM64_VA_BITS_52 1631 1632choice 1633 prompt "Physical address space size" 1634 default ARM64_PA_BITS_48 1635 help 1636 Choose the maximum physical address range that the kernel will 1637 support. 1638 1639config ARM64_PA_BITS_48 1640 bool "48-bit" 1641 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1642 1643config ARM64_PA_BITS_52 1644 bool "52-bit" 1645 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1646 help 1647 Enable support for a 52-bit physical address space, introduced as 1648 part of the ARMv8.2-LPA extension. 1649 1650 With this enabled, the kernel will also continue to work on CPUs that 1651 do not support ARMv8.2-LPA, but with some added memory overhead (and 1652 minor performance overhead). 1653 1654endchoice 1655 1656config ARM64_PA_BITS 1657 int 1658 default 48 if ARM64_PA_BITS_48 1659 default 52 if ARM64_PA_BITS_52 1660 1661config ARM64_LPA2 1662 def_bool y 1663 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1664 1665config NR_CPUS 1666 int "Maximum number of CPUs (2-4096)" 1667 range 2 4096 1668 default "512" 1669 1670config HOTPLUG_CPU 1671 bool "Support for hot-pluggable CPUs" 1672 select GENERIC_IRQ_MIGRATION 1673 help 1674 Say Y here to experiment with turning CPUs off and on. CPUs 1675 can be controlled through /sys/devices/system/cpu. 1676 1677# Common NUMA Features 1678config NUMA 1679 bool "NUMA Memory Allocation and Scheduler Support" 1680 select GENERIC_ARCH_NUMA 1681 select OF_NUMA 1682 select HAVE_SETUP_PER_CPU_AREA 1683 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1684 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1685 select USE_PERCPU_NUMA_NODE_ID 1686 help 1687 Enable NUMA (Non-Uniform Memory Access) support. 1688 1689 The kernel will try to allocate memory used by a CPU on the 1690 local memory of the CPU and add some more 1691 NUMA awareness to the kernel. 1692 1693config NODES_SHIFT 1694 int "Maximum NUMA Nodes (as a power of 2)" 1695 range 1 10 1696 default "4" 1697 depends on NUMA 1698 help 1699 Specify the maximum number of NUMA Nodes available on the target 1700 system. Increases memory reserved to accommodate various tables. 1701 1702source "kernel/Kconfig.hz" 1703 1704config ARCH_SPARSEMEM_ENABLE 1705 def_bool y 1706 select SPARSEMEM_VMEMMAP_ENABLE 1707 1708config HW_PERF_EVENTS 1709 def_bool y 1710 depends on ARM_PMU 1711 1712# Supported by clang >= 7.0 or GCC >= 12.0.0 1713config CC_HAVE_SHADOW_CALL_STACK 1714 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1715 1716config PARAVIRT 1717 bool "Enable paravirtualization code" 1718 select HAVE_PV_STEAL_CLOCK_GEN 1719 help 1720 This changes the kernel so it can modify itself when it is run 1721 under a hypervisor, potentially improving performance significantly 1722 over full virtualization. 1723 1724config PARAVIRT_TIME_ACCOUNTING 1725 bool "Paravirtual steal time accounting" 1726 select PARAVIRT 1727 help 1728 Select this option to enable fine granularity task steal time 1729 accounting. Time spent executing other tasks in parallel with 1730 the current vCPU is discounted from the vCPU power. To account for 1731 that, there can be a small performance impact. 1732 1733 If in doubt, say N here. 1734 1735config ARCH_SUPPORTS_KEXEC 1736 def_bool PM_SLEEP_SMP 1737 1738config ARCH_SUPPORTS_KEXEC_FILE 1739 def_bool y 1740 1741config ARCH_SELECTS_KEXEC_FILE 1742 def_bool y 1743 depends on KEXEC_FILE 1744 select HAVE_IMA_KEXEC if IMA 1745 1746config ARCH_SUPPORTS_KEXEC_SIG 1747 def_bool y 1748 1749config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1750 def_bool y 1751 1752config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1753 def_bool y 1754 1755config ARCH_SUPPORTS_KEXEC_HANDOVER 1756 def_bool y 1757 1758config ARCH_SUPPORTS_CRASH_DUMP 1759 def_bool y 1760 1761config ARCH_DEFAULT_CRASH_DUMP 1762 def_bool y 1763 1764config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1765 def_bool CRASH_RESERVE 1766 1767config TRANS_TABLE 1768 def_bool y 1769 depends on HIBERNATION || KEXEC_CORE 1770 1771config XEN_DOM0 1772 def_bool y 1773 depends on XEN 1774 1775config XEN 1776 bool "Xen guest support on ARM64" 1777 depends on ARM64 && OF 1778 select SWIOTLB_XEN 1779 select PARAVIRT 1780 help 1781 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1782 1783# include/linux/mmzone.h requires the following to be true: 1784# 1785# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1786# 1787# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1788# 1789# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1790# ----+-------------------+--------------+----------------------+-------------------------+ 1791# 4K | 27 | 12 | 15 | 10 | 1792# 16K | 27 | 14 | 13 | 11 | 1793# 64K | 29 | 16 | 13 | 13 | 1794config ARCH_FORCE_MAX_ORDER 1795 int 1796 default "13" if ARM64_64K_PAGES 1797 default "11" if ARM64_16K_PAGES 1798 default "10" 1799 help 1800 The kernel page allocator limits the size of maximal physically 1801 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1802 defines the maximal power of two of number of pages that can be 1803 allocated as a single contiguous block. This option allows 1804 overriding the default setting when ability to allocate very 1805 large blocks of physically contiguous memory is required. 1806 1807 The maximal size of allocation cannot exceed the size of the 1808 section, so the value of MAX_PAGE_ORDER should satisfy 1809 1810 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1811 1812 Don't change if unsure. 1813 1814config UNMAP_KERNEL_AT_EL0 1815 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1816 default y 1817 help 1818 Speculation attacks against some high-performance processors can 1819 be used to bypass MMU permission checks and leak kernel data to 1820 userspace. This can be defended against by unmapping the kernel 1821 when running in userspace, mapping it back in on exception entry 1822 via a trampoline page in the vector table. 1823 1824 If unsure, say Y. 1825 1826config MITIGATE_SPECTRE_BRANCH_HISTORY 1827 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1828 default y 1829 help 1830 Speculation attacks against some high-performance processors can 1831 make use of branch history to influence future speculation. 1832 When taking an exception from user-space, a sequence of branches 1833 or a firmware call overwrites the branch history. 1834 1835config ARM64_SW_TTBR0_PAN 1836 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1837 depends on !KCSAN 1838 help 1839 Enabling this option prevents the kernel from accessing 1840 user-space memory directly by pointing TTBR0_EL1 to a reserved 1841 zeroed area and reserved ASID. The user access routines 1842 restore the valid TTBR0_EL1 temporarily. 1843 1844config ARM64_TAGGED_ADDR_ABI 1845 bool "Enable the tagged user addresses syscall ABI" 1846 default y 1847 help 1848 When this option is enabled, user applications can opt in to a 1849 relaxed ABI via prctl() allowing tagged addresses to be passed 1850 to system calls as pointer arguments. For details, see 1851 Documentation/arch/arm64/tagged-address-abi.rst. 1852 1853menuconfig COMPAT 1854 bool "Kernel support for 32-bit EL0" 1855 depends on ARM64_4K_PAGES || EXPERT 1856 select HAVE_UID16 1857 select OLD_SIGSUSPEND3 1858 select COMPAT_OLD_SIGACTION 1859 help 1860 This option enables support for a 32-bit EL0 running under a 64-bit 1861 kernel at EL1. AArch32-specific components such as system calls, 1862 the user helper functions, VFP support and the ptrace interface are 1863 handled appropriately by the kernel. 1864 1865 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1866 that you will only be able to execute AArch32 binaries that were compiled 1867 with page size aligned segments. 1868 1869 If you want to execute 32-bit userspace applications, say Y. 1870 1871if COMPAT 1872 1873config KUSER_HELPERS 1874 bool "Enable kuser helpers page for 32-bit applications" 1875 default y 1876 help 1877 Warning: disabling this option may break 32-bit user programs. 1878 1879 Provide kuser helpers to compat tasks. The kernel provides 1880 helper code to userspace in read only form at a fixed location 1881 to allow userspace to be independent of the CPU type fitted to 1882 the system. This permits binaries to be run on ARMv4 through 1883 to ARMv8 without modification. 1884 1885 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1886 1887 However, the fixed address nature of these helpers can be used 1888 by ROP (return orientated programming) authors when creating 1889 exploits. 1890 1891 If all of the binaries and libraries which run on your platform 1892 are built specifically for your platform, and make no use of 1893 these helpers, then you can turn this option off to hinder 1894 such exploits. However, in that case, if a binary or library 1895 relying on those helpers is run, it will not function correctly. 1896 1897 Say N here only if you are absolutely certain that you do not 1898 need these helpers; otherwise, the safe option is to say Y. 1899 1900config COMPAT_VDSO 1901 bool "Enable vDSO for 32-bit applications" 1902 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1903 default y 1904 help 1905 Place in the process address space of 32-bit applications an 1906 ELF shared object providing fast implementations of gettimeofday 1907 and clock_gettime. 1908 1909 You must have a 32-bit build of glibc 2.22 or later for programs 1910 to seamlessly take advantage of this. 1911 1912config THUMB2_COMPAT_VDSO 1913 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1914 depends on COMPAT_VDSO 1915 default y 1916 help 1917 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1918 otherwise with '-marm'. 1919 1920config COMPAT_ALIGNMENT_FIXUPS 1921 bool "Fix up misaligned multi-word loads and stores in user space" 1922 1923menuconfig ARMV8_DEPRECATED 1924 bool "Emulate deprecated/obsolete ARMv8 instructions" 1925 depends on SYSCTL 1926 help 1927 Legacy software support may require certain instructions 1928 that have been deprecated or obsoleted in the architecture. 1929 1930 Enable this config to enable selective emulation of these 1931 features. 1932 1933 If unsure, say Y 1934 1935if ARMV8_DEPRECATED 1936 1937config SWP_EMULATION 1938 bool "Emulate SWP/SWPB instructions" 1939 help 1940 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1941 they are always undefined. Say Y here to enable software 1942 emulation of these instructions for userspace using LDXR/STXR. 1943 This feature can be controlled at runtime with the abi.swp 1944 sysctl which is disabled by default. 1945 1946 In some older versions of glibc [<=2.8] SWP is used during futex 1947 trylock() operations with the assumption that the code will not 1948 be preempted. This invalid assumption may be more likely to fail 1949 with SWP emulation enabled, leading to deadlock of the user 1950 application. 1951 1952 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1953 on an external transaction monitoring block called a global 1954 monitor to maintain update atomicity. If your system does not 1955 implement a global monitor, this option can cause programs that 1956 perform SWP operations to uncached memory to deadlock. 1957 1958 If unsure, say Y 1959 1960config CP15_BARRIER_EMULATION 1961 bool "Emulate CP15 Barrier instructions" 1962 help 1963 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1964 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1965 strongly recommended to use the ISB, DSB, and DMB 1966 instructions instead. 1967 1968 Say Y here to enable software emulation of these 1969 instructions for AArch32 userspace code. When this option is 1970 enabled, CP15 barrier usage is traced which can help 1971 identify software that needs updating. This feature can be 1972 controlled at runtime with the abi.cp15_barrier sysctl. 1973 1974 If unsure, say Y 1975 1976config SETEND_EMULATION 1977 bool "Emulate SETEND instruction" 1978 help 1979 The SETEND instruction alters the data-endianness of the 1980 AArch32 EL0, and is deprecated in ARMv8. 1981 1982 Say Y here to enable software emulation of the instruction 1983 for AArch32 userspace code. This feature can be controlled 1984 at runtime with the abi.setend sysctl. 1985 1986 Note: All the cpus on the system must have mixed endian support at EL0 1987 for this feature to be enabled. If a new CPU - which doesn't support mixed 1988 endian - is hotplugged in after this feature has been enabled, there could 1989 be unexpected results in the applications. 1990 1991 If unsure, say Y 1992endif # ARMV8_DEPRECATED 1993 1994endif # COMPAT 1995 1996menu "ARMv8.1 architectural features" 1997 1998config ARM64_HW_AFDBM 1999 bool "Support for hardware updates of the Access and Dirty page flags" 2000 default y 2001 help 2002 The ARMv8.1 architecture extensions introduce support for 2003 hardware updates of the access and dirty information in page 2004 table entries. When enabled in TCR_EL1 (HA and HD bits) on 2005 capable processors, accesses to pages with PTE_AF cleared will 2006 set this bit instead of raising an access flag fault. 2007 Similarly, writes to read-only pages with the DBM bit set will 2008 clear the read-only bit (AP[2]) instead of raising a 2009 permission fault. 2010 2011 Kernels built with this configuration option enabled continue 2012 to work on pre-ARMv8.1 hardware and the performance impact is 2013 minimal. If unsure, say Y. 2014 2015endmenu # "ARMv8.1 architectural features" 2016 2017menu "ARMv8.2 architectural features" 2018 2019config ARM64_PMEM 2020 bool "Enable support for persistent memory" 2021 select ARCH_HAS_PMEM_API 2022 select ARCH_HAS_UACCESS_FLUSHCACHE 2023 help 2024 Say Y to enable support for the persistent memory API based on the 2025 ARMv8.2 DCPoP feature. 2026 2027 The feature is detected at runtime, and the kernel will use DC CVAC 2028 operations if DC CVAP is not supported (following the behaviour of 2029 DC CVAP itself if the system does not define a point of persistence). 2030 2031config ARM64_RAS_EXTN 2032 bool "Enable support for RAS CPU Extensions" 2033 default y 2034 help 2035 CPUs that support the Reliability, Availability and Serviceability 2036 (RAS) Extensions, part of ARMv8.2 are able to track faults and 2037 errors, classify them and report them to software. 2038 2039 On CPUs with these extensions system software can use additional 2040 barriers to determine if faults are pending and read the 2041 classification from a new set of registers. 2042 2043 Selecting this feature will allow the kernel to use these barriers 2044 and access the new registers if the system supports the extension. 2045 Platform RAS features may additionally depend on firmware support. 2046 2047config ARM64_CNP 2048 bool "Enable support for Common Not Private (CNP) translations" 2049 default y 2050 help 2051 Common Not Private (CNP) allows translation table entries to 2052 be shared between different PEs in the same inner shareable 2053 domain, so the hardware can use this fact to optimise the 2054 caching of such entries in the TLB. 2055 2056 Selecting this option allows the CNP feature to be detected 2057 at runtime, and does not affect PEs that do not implement 2058 this feature. 2059 2060endmenu # "ARMv8.2 architectural features" 2061 2062menu "ARMv8.3 architectural features" 2063 2064config ARM64_PTR_AUTH 2065 bool "Enable support for pointer authentication" 2066 default y 2067 help 2068 Pointer authentication (part of the ARMv8.3 Extensions) provides 2069 instructions for signing and authenticating pointers against secret 2070 keys, which can be used to mitigate Return Oriented Programming (ROP) 2071 and other attacks. 2072 2073 This option enables these instructions at EL0 (i.e. for userspace). 2074 Choosing this option will cause the kernel to initialise secret keys 2075 for each process at exec() time, with these keys being 2076 context-switched along with the process. 2077 2078 The feature is detected at runtime. If the feature is not present in 2079 hardware it will not be advertised to userspace/KVM guest nor will it 2080 be enabled. 2081 2082 If the feature is present on the boot CPU but not on a late CPU, then 2083 the late CPU will be parked. Also, if the boot CPU does not have 2084 address auth and the late CPU has then the late CPU will still boot 2085 but with the feature disabled. On such a system, this option should 2086 not be selected. 2087 2088config ARM64_PTR_AUTH_KERNEL 2089 bool "Use pointer authentication for kernel" 2090 default y 2091 depends on ARM64_PTR_AUTH 2092 # Modern compilers insert a .note.gnu.property section note for PAC 2093 # which is only understood by binutils starting with version 2.33.1. 2094 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2095 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2096 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2097 help 2098 If the compiler supports the -mbranch-protection or 2099 -msign-return-address flag (e.g. GCC 7 or later), then this option 2100 will cause the kernel itself to be compiled with return address 2101 protection. In this case, and if the target hardware is known to 2102 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2103 disabled with minimal loss of protection. 2104 2105 This feature works with FUNCTION_GRAPH_TRACER option only if 2106 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2107 2108config CC_HAS_BRANCH_PROT_PAC_RET 2109 # GCC 9 or later, clang 8 or later 2110 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2111 2112config AS_HAS_CFI_NEGATE_RA_STATE 2113 # binutils 2.34+ 2114 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2115 2116endmenu # "ARMv8.3 architectural features" 2117 2118menu "ARMv8.4 architectural features" 2119 2120config ARM64_AMU_EXTN 2121 bool "Enable support for the Activity Monitors Unit CPU extension" 2122 default y 2123 help 2124 The activity monitors extension is an optional extension introduced 2125 by the ARMv8.4 CPU architecture. This enables support for version 1 2126 of the activity monitors architecture, AMUv1. 2127 2128 To enable the use of this extension on CPUs that implement it, say Y. 2129 2130 Note that for architectural reasons, firmware _must_ implement AMU 2131 support when running on CPUs that present the activity monitors 2132 extension. The required support is present in: 2133 * Version 1.5 and later of the ARM Trusted Firmware 2134 2135 For kernels that have this configuration enabled but boot with broken 2136 firmware, you may need to say N here until the firmware is fixed. 2137 Otherwise you may experience firmware panics or lockups when 2138 accessing the counter registers. Even if you are not observing these 2139 symptoms, the values returned by the register reads might not 2140 correctly reflect reality. Most commonly, the value read will be 0, 2141 indicating that the counter is not enabled. 2142 2143config ARM64_TLB_RANGE 2144 bool "Enable support for tlbi range feature" 2145 default y 2146 help 2147 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2148 range of input addresses. 2149 2150config ARM64_MPAM 2151 bool "Enable support for MPAM" 2152 select ARM64_MPAM_DRIVER 2153 select ARCH_HAS_CPU_RESCTRL 2154 help 2155 Memory System Resource Partitioning and Monitoring (MPAM) is an 2156 optional extension to the Arm architecture that allows each 2157 transaction issued to the memory system to be labelled with a 2158 Partition identifier (PARTID) and Performance Monitoring Group 2159 identifier (PMG). 2160 2161 Memory system components, such as the caches, can be configured with 2162 policies to control how much of various physical resources (such as 2163 memory bandwidth or cache memory) the transactions labelled with each 2164 PARTID can consume. Depending on the capabilities of the hardware, 2165 the PARTID and PMG can also be used as filtering criteria to measure 2166 the memory system resource consumption of different parts of a 2167 workload. 2168 2169 Use of this extension requires CPU support, support in the 2170 Memory System Components (MSC), and a description from firmware 2171 of where the MSCs are in the address space. 2172 2173 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2174 2175 This option enables the extra context switch code. 2176 2177endmenu # "ARMv8.4 architectural features" 2178 2179menu "ARMv8.5 architectural features" 2180 2181config AS_HAS_ARMV8_5 2182 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2183 2184config ARM64_BTI 2185 bool "Branch Target Identification support" 2186 default y 2187 help 2188 Branch Target Identification (part of the ARMv8.5 Extensions) 2189 provides a mechanism to limit the set of locations to which computed 2190 branch instructions such as BR or BLR can jump. 2191 2192 To make use of BTI on CPUs that support it, say Y. 2193 2194 BTI is intended to provide complementary protection to other control 2195 flow integrity protection mechanisms, such as the Pointer 2196 authentication mechanism provided as part of the ARMv8.3 Extensions. 2197 For this reason, it does not make sense to enable this option without 2198 also enabling support for pointer authentication. Thus, when 2199 enabling this option you should also select ARM64_PTR_AUTH=y. 2200 2201 Userspace binaries must also be specifically compiled to make use of 2202 this mechanism. If you say N here or the hardware does not support 2203 BTI, such binaries can still run, but you get no additional 2204 enforcement of branch destinations. 2205 2206config ARM64_BTI_KERNEL 2207 bool "Use Branch Target Identification for kernel" 2208 default y 2209 depends on ARM64_BTI 2210 depends on ARM64_PTR_AUTH_KERNEL 2211 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2212 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2213 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2214 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2215 depends on !CC_IS_GCC 2216 # https://github.com/llvm/llvm-project/issues/215547 2217 depends on !CC_IS_CLANG || CLANG_VERSION < 210000 2218 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2219 help 2220 Build the kernel with Branch Target Identification annotations 2221 and enable enforcement of this for kernel code. When this option 2222 is enabled and the system supports BTI all kernel code including 2223 modular code must have BTI enabled. 2224 2225config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2226 # GCC 9 or later, clang 8 or later 2227 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2228 2229config ARM64_E0PD 2230 bool "Enable support for E0PD" 2231 default y 2232 help 2233 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2234 that EL0 accesses made via TTBR1 always fault in constant time, 2235 providing similar benefits to KASLR as those provided by KPTI, but 2236 with lower overhead and without disrupting legitimate access to 2237 kernel memory such as SPE. 2238 2239 This option enables E0PD for TTBR1 where available. 2240 2241config ARM64_AS_HAS_MTE 2242 # Initial support for MTE went in binutils 2.32.0, checked with 2243 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2244 # as a late addition to the final architecture spec (LDGM/STGM) 2245 # is only supported in the newer 2.32.x and 2.33 binutils 2246 # versions, hence the extra "stgm" instruction check below. 2247 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2248 2249config ARM64_MTE 2250 bool "Memory Tagging Extension support" 2251 default y 2252 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2253 depends on AS_HAS_ARMV8_5 2254 # Required for tag checking in the uaccess routines 2255 select ARCH_HAS_SUBPAGE_FAULTS 2256 select ARCH_USES_HIGH_VMA_FLAGS 2257 select ARCH_USES_PG_ARCH_2 2258 select ARCH_USES_PG_ARCH_3 2259 help 2260 Memory Tagging (part of the ARMv8.5 Extensions) provides 2261 architectural support for run-time, always-on detection of 2262 various classes of memory error to aid with software debugging 2263 to eliminate vulnerabilities arising from memory-unsafe 2264 languages. 2265 2266 This option enables the support for the Memory Tagging 2267 Extension at EL0 (i.e. for userspace). 2268 2269 Selecting this option allows the feature to be detected at 2270 runtime. Any secondary CPU not implementing this feature will 2271 not be allowed a late bring-up. 2272 2273 Userspace binaries that want to use this feature must 2274 explicitly opt in. The mechanism for the userspace is 2275 described in: 2276 2277 Documentation/arch/arm64/memory-tagging-extension.rst. 2278 2279endmenu # "ARMv8.5 architectural features" 2280 2281menu "ARMv8.7 architectural features" 2282 2283config ARM64_EPAN 2284 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2285 default y 2286 help 2287 Enhanced Privileged Access Never (EPAN) allows Privileged 2288 Access Never to be used with Execute-only mappings. 2289 2290 The feature is detected at runtime, and will remain disabled 2291 if the cpu does not implement the feature. 2292endmenu # "ARMv8.7 architectural features" 2293 2294config AS_HAS_MOPS 2295 def_bool $(as-instr,.arch_extension mops) 2296 2297menu "ARMv8.9 architectural features" 2298 2299config ARM64_POE 2300 prompt "Permission Overlay Extension" 2301 def_bool y 2302 select ARCH_USES_HIGH_VMA_FLAGS 2303 select ARCH_HAS_PKEYS 2304 help 2305 The Permission Overlay Extension is used to implement Memory 2306 Protection Keys. Memory Protection Keys provides a mechanism for 2307 enforcing page-based protections, but without requiring modification 2308 of the page tables when an application changes protection domains. 2309 2310 For details, see Documentation/core-api/protection-keys.rst 2311 2312 If unsure, say y. 2313 2314config ARCH_PKEY_BITS 2315 int 2316 default 3 2317 2318config ARM64_HAFT 2319 bool "Support for Hardware managed Access Flag for Table Descriptors" 2320 depends on ARM64_HW_AFDBM 2321 default y 2322 help 2323 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2324 Flag for Table descriptors. When enabled an architectural executed 2325 memory access will update the Access Flag in each Table descriptor 2326 which is accessed during the translation table walk and for which 2327 the Access Flag is 0. The Access Flag of the Table descriptor use 2328 the same bit of PTE_AF. 2329 2330 The feature will only be enabled if all the CPUs in the system 2331 support this feature. If unsure, say Y. 2332 2333endmenu # "ARMv8.9 architectural features" 2334 2335menu "ARMv9.4 architectural features" 2336 2337config ARM64_GCS 2338 bool "Enable support for Guarded Control Stack (GCS)" 2339 default y 2340 select ARCH_HAS_USER_SHADOW_STACK 2341 select ARCH_USES_HIGH_VMA_FLAGS 2342 help 2343 Guarded Control Stack (GCS) provides support for a separate 2344 stack with restricted access which contains only return 2345 addresses. This can be used to harden against some attacks 2346 by comparing return address used by the program with what is 2347 stored in the GCS, and may also be used to efficiently obtain 2348 the call stack for applications such as profiling. 2349 2350 The feature is detected at runtime, and will remain disabled 2351 if the system does not implement the feature. 2352 2353endmenu # "ARMv9.4 architectural features" 2354 2355config AS_HAS_LSUI 2356 def_bool $(as-instr,.arch_extension lsui) 2357 help 2358 Supported by LLVM 20+ and binutils 2.45+. 2359 2360menu "ARMv9.6 architectural features" 2361 2362config ARM64_LSUI 2363 bool "Support Unprivileged Load Store Instructions (LSUI)" 2364 default y 2365 depends on AS_HAS_LSUI 2366 help 2367 The Unprivileged Load Store Instructions (LSUI) provides 2368 variants load/store instructions that access user-space memory 2369 from the kernel without clearing PSTATE.PAN bit. 2370 2371 This feature is supported by LLVM 20+ and binutils 2.45+. 2372 2373endmenu # "ARMv9.6 architectural feature" 2374 2375config ARM64_SVE 2376 bool "ARM Scalable Vector Extension support" 2377 default y 2378 help 2379 The Scalable Vector Extension (SVE) is an extension to the AArch64 2380 execution state which complements and extends the SIMD functionality 2381 of the base architecture to support much larger vectors and to enable 2382 additional vectorisation opportunities. 2383 2384 To enable use of this extension on CPUs that implement it, say Y. 2385 2386 On CPUs that support the SVE2 extensions, this option will enable 2387 those too. 2388 2389 Note that for architectural reasons, firmware _must_ implement SVE 2390 support when running on SVE capable hardware. The required support 2391 is present in: 2392 2393 * version 1.5 and later of the ARM Trusted Firmware 2394 * the AArch64 boot wrapper since commit 5e1261e08abf 2395 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2396 2397 For other firmware implementations, consult the firmware documentation 2398 or vendor. 2399 2400 If you need the kernel to boot on SVE-capable hardware with broken 2401 firmware, you may need to say N here until you get your firmware 2402 fixed. Otherwise, you may experience firmware panics or lockups when 2403 booting the kernel. If unsure and you are not observing these 2404 symptoms, you should assume that it is safe to say Y. 2405 2406config AS_HAS_SME 2407 # Supported by LLVM 13+ and binutils 2.38+ 2408 def_bool $(as-instr,.arch_extension sme) 2409 2410config ARM64_SME 2411 bool "ARM Scalable Matrix Extension support" 2412 default y 2413 depends on ARM64_SVE 2414 depends on AS_HAS_SME 2415 help 2416 The Scalable Matrix Extension (SME) is an extension to the AArch64 2417 execution state which utilises a substantial subset of the SVE 2418 instruction set, together with the addition of new architectural 2419 register state capable of holding two dimensional matrix tiles to 2420 enable various matrix operations. 2421 2422config ARM64_PSEUDO_NMI 2423 bool "Support for NMI-like interrupts" 2424 select ARM_GIC_V3 2425 help 2426 Adds support for mimicking Non-Maskable Interrupts through the use of 2427 GIC interrupt priority. This support requires version 3 or later of 2428 ARM GIC. 2429 2430 This high priority configuration for interrupts needs to be 2431 explicitly enabled by setting the kernel parameter 2432 "irqchip.gicv3_pseudo_nmi" to 1. 2433 2434 If unsure, say N 2435 2436if ARM64_PSEUDO_NMI 2437config ARM64_DEBUG_PRIORITY_MASKING 2438 bool "Debug interrupt priority masking" 2439 help 2440 This adds runtime checks to functions enabling/disabling 2441 interrupts when using priority masking. The additional checks verify 2442 the validity of ICC_PMR_EL1 when calling concerned functions. 2443 2444 If unsure, say N 2445endif # ARM64_PSEUDO_NMI 2446 2447config RELOCATABLE 2448 bool "Build a relocatable kernel image" if EXPERT 2449 select ARCH_HAS_RELR 2450 default y 2451 help 2452 This builds the kernel as a Position Independent Executable (PIE), 2453 which retains all relocation metadata required to relocate the 2454 kernel binary at runtime to a different virtual address than the 2455 address it was linked at. 2456 Since AArch64 uses the RELA relocation format, this requires a 2457 relocation pass at runtime even if the kernel is loaded at the 2458 same address it was linked at. 2459 2460config RANDOMIZE_BASE 2461 bool "Randomize the address of the kernel image" 2462 select RELOCATABLE 2463 help 2464 Randomizes the virtual address at which the kernel image is 2465 loaded, as a security feature that deters exploit attempts 2466 relying on knowledge of the location of kernel internals. 2467 2468 It is the bootloader's job to provide entropy, by passing a 2469 random u64 value in /chosen/kaslr-seed at kernel entry. 2470 2471 When booting via the UEFI stub, it will invoke the firmware's 2472 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2473 to the kernel proper. In addition, it will randomise the physical 2474 location of the kernel Image as well. 2475 2476 If unsure, say N. 2477 2478config RANDOMIZE_MODULE_REGION_FULL 2479 bool "Randomize the module region over a 2 GB range" 2480 depends on RANDOMIZE_BASE 2481 default y 2482 help 2483 Randomizes the location of the module region inside a 2 GB window 2484 covering the core kernel. This way, it is less likely for modules 2485 to leak information about the location of core kernel data structures 2486 but it does imply that function calls between modules and the core 2487 kernel will need to be resolved via veneers in the module PLT. 2488 2489 When this option is not set, the module region will be randomized over 2490 a limited range that contains the [_stext, _etext] interval of the 2491 core kernel, so branch relocations are almost always in range unless 2492 the region is exhausted. In this particular case of region 2493 exhaustion, modules might be able to fall back to a larger 2GB area. 2494 2495config CC_HAVE_STACKPROTECTOR_SYSREG 2496 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2497 2498config STACKPROTECTOR_PER_TASK 2499 def_bool y 2500 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2501 2502config UNWIND_PATCH_PAC_INTO_SCS 2503 bool "Enable shadow call stack dynamically using code patching" 2504 depends on CC_IS_CLANG 2505 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2506 depends on SHADOW_CALL_STACK 2507 select UNWIND_TABLES 2508 select DYNAMIC_SCS 2509 2510config ARM64_CONTPTE 2511 bool "Contiguous PTE mappings for user memory" if EXPERT 2512 depends on TRANSPARENT_HUGEPAGE 2513 default y 2514 help 2515 When enabled, user mappings are configured using the PTE contiguous 2516 bit, for any mappings that meet the size and alignment requirements. 2517 This reduces TLB pressure and improves performance. 2518 2519endmenu # "Kernel Features" 2520 2521menu "Boot options" 2522 2523config ARM64_ACPI_PARKING_PROTOCOL 2524 bool "Enable support for the ARM64 ACPI parking protocol" 2525 depends on ACPI 2526 help 2527 Enable support for the ARM64 ACPI parking protocol. If disabled 2528 the kernel will not allow booting through the ARM64 ACPI parking 2529 protocol even if the corresponding data is present in the ACPI 2530 MADT table. 2531 2532config CMDLINE 2533 string "Default kernel command string" 2534 default "" 2535 help 2536 Provide a set of default command-line options at build time by 2537 entering them here. As a minimum, you should specify the 2538 root device (e.g. root=/dev/nfs). 2539 2540choice 2541 prompt "Kernel command line type" 2542 depends on CMDLINE != "" 2543 default CMDLINE_FROM_BOOTLOADER 2544 help 2545 Choose how the kernel will handle the provided default kernel 2546 command line string. 2547 2548config CMDLINE_FROM_BOOTLOADER 2549 bool "Use bootloader kernel arguments if available" 2550 help 2551 Uses the command-line options passed by the boot loader. If 2552 the boot loader doesn't provide any, the default kernel command 2553 string provided in CMDLINE will be used. 2554 2555config CMDLINE_FORCE 2556 bool "Always use the default kernel command string" 2557 help 2558 Always use the default kernel command string, even if the boot 2559 loader passes other arguments to the kernel. 2560 This is useful if you cannot or don't want to change the 2561 command-line options your boot loader passes to the kernel. 2562 2563endchoice 2564 2565config EFI_STUB 2566 bool 2567 2568config EFI 2569 bool "UEFI runtime support" 2570 depends on OF 2571 depends on KERNEL_MODE_NEON 2572 select ARCH_SUPPORTS_ACPI 2573 select LIBFDT 2574 select UCS2_STRING 2575 select EFI_PARAMS_FROM_FDT 2576 select EFI_RUNTIME_WRAPPERS 2577 select EFI_STUB 2578 select EFI_GENERIC_STUB 2579 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2580 default y 2581 help 2582 This option provides support for runtime services provided 2583 by UEFI firmware (such as non-volatile variables, realtime 2584 clock, and platform reset). A UEFI stub is also provided to 2585 allow the kernel to be booted as an EFI application. This 2586 is only useful on systems that have UEFI firmware. 2587 2588config COMPRESSED_INSTALL 2589 bool "Install compressed image by default" 2590 help 2591 This makes the regular "make install" install the compressed 2592 image we built, not the legacy uncompressed one. 2593 2594 You can check that a compressed image works for you by doing 2595 "make zinstall" first, and verifying that everything is fine 2596 in your environment before making "make install" do this for 2597 you. 2598 2599config DMI 2600 bool "Enable support for SMBIOS (DMI) tables" 2601 depends on EFI 2602 default y 2603 help 2604 This enables SMBIOS/DMI feature for systems. 2605 2606 This option is only useful on systems that have UEFI firmware. 2607 However, even with this option, the resultant kernel should 2608 continue to boot on existing non-UEFI platforms. 2609 2610endmenu # "Boot options" 2611 2612menu "Power management options" 2613 2614source "kernel/power/Kconfig" 2615 2616config ARCH_HIBERNATION_POSSIBLE 2617 def_bool y 2618 depends on CPU_PM 2619 2620config ARCH_HIBERNATION_HEADER 2621 def_bool y 2622 depends on HIBERNATION 2623 2624config ARCH_SUSPEND_POSSIBLE 2625 def_bool y 2626 2627endmenu # "Power management options" 2628 2629menu "CPU Power Management" 2630 2631source "drivers/cpuidle/Kconfig" 2632 2633source "drivers/cpufreq/Kconfig" 2634 2635endmenu # "CPU Power Management" 2636 2637source "drivers/acpi/Kconfig" 2638 2639source "arch/arm64/kvm/Kconfig" 2640 2641source "kernel/livepatch/Kconfig" 2642