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 if CPU_LITTLE_ENDIAN 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_RT 87 select ARCH_SUPPORTS_SCHED_SMT 88 select ARCH_SUPPORTS_SCHED_CLUSTER 89 select ARCH_SUPPORTS_SCHED_MC 90 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 91 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 92 select ARCH_WANT_DEFAULT_BPF_JIT 93 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 94 select ARCH_WANT_FRAME_POINTERS 95 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 96 select ARCH_WANT_LD_ORPHAN_WARN 97 select ARCH_WANTS_EXECMEM_LATE 98 select ARCH_WANTS_NO_INSTR 99 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 100 select ARCH_HAS_UBSAN 101 select ARM_AMBA 102 select ARM_ARCH_TIMER 103 select ARM_GIC 104 select AUDIT_ARCH_COMPAT_GENERIC 105 select ARM_GIC_V2M if PCI 106 select ARM_GIC_V3 107 select ARM_GIC_V3_ITS if PCI 108 select ARM_GIC_V5 109 select ARM_PSCI_FW 110 select BUILDTIME_TABLE_SORT 111 select CLONE_BACKWARDS 112 select COMMON_CLK 113 select CPU_PM if (SUSPEND || CPU_IDLE) 114 select CPUMASK_OFFSTACK if NR_CPUS > 256 115 select DCACHE_WORD_ACCESS 116 select HAVE_EXTRA_IPI_TRACEPOINTS 117 select DYNAMIC_FTRACE if FUNCTION_TRACER 118 select DMA_BOUNCE_UNALIGNED_KMALLOC 119 select DMA_DIRECT_REMAP 120 select EDAC_SUPPORT 121 select FRAME_POINTER 122 select FUNCTION_ALIGNMENT_4B 123 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 124 select GENERIC_ALLOCATOR 125 select GENERIC_ARCH_TOPOLOGY 126 select GENERIC_CLOCKEVENTS_BROADCAST 127 select GENERIC_CPU_AUTOPROBE 128 select GENERIC_CPU_CACHE_MAINTENANCE 129 select GENERIC_CPU_DEVICES 130 select GENERIC_CPU_VULNERABILITIES 131 select GENERIC_EARLY_IOREMAP 132 select GENERIC_IDLE_POLL_SETUP 133 select GENERIC_IOREMAP 134 select GENERIC_IRQ_ENTRY 135 select GENERIC_IRQ_IPI 136 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 137 select GENERIC_IRQ_PROBE 138 select GENERIC_IRQ_SHOW 139 select GENERIC_IRQ_SHOW_LEVEL 140 select GENERIC_LIB_DEVMEM_IS_ALLOWED 141 select GENERIC_PCI_IOMAP 142 select GENERIC_SCHED_CLOCK 143 select GENERIC_SMP_IDLE_THREAD 144 select GENERIC_GETTIMEOFDAY 145 select HARDIRQS_SW_RESEND 146 select HAS_IOPORT 147 select HAVE_MOVE_PMD 148 select HAVE_MOVE_PUD 149 select HAVE_PCI 150 select HAVE_ACPI_APEI if (ACPI && EFI) 151 select HAVE_ALIGNED_STRUCT_PAGE 152 select HAVE_ARCH_AUDITSYSCALL 153 select HAVE_ARCH_BITREVERSE if BITREVERSE 154 select HAVE_ARCH_COMPILER_H 155 select HAVE_ARCH_HUGE_VMALLOC 156 select HAVE_ARCH_HUGE_VMAP 157 select HAVE_ARCH_JUMP_LABEL 158 select HAVE_ARCH_JUMP_LABEL_RELATIVE 159 select HAVE_ARCH_KASAN 160 select HAVE_ARCH_KASAN_VMALLOC 161 select HAVE_ARCH_KASAN_SW_TAGS 162 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 163 # Some instrumentation may be unsound, hence EXPERT 164 select HAVE_ARCH_KCSAN if EXPERT 165 select HAVE_ARCH_KFENCE 166 select HAVE_ARCH_KGDB 167 select HAVE_ARCH_KSTACK_ERASE 168 select HAVE_ARCH_MMAP_RND_BITS 169 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 170 select HAVE_ARCH_PREL32_RELOCATIONS 171 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 172 select HAVE_ARCH_SECCOMP_FILTER 173 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 174 select HAVE_ARCH_TRACEHOOK 175 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 176 select HAVE_ARCH_VMAP_STACK 177 select HAVE_ARM_SMCCC 178 select HAVE_ASM_MODVERSIONS 179 select HAVE_EBPF_JIT 180 select HAVE_C_RECORDMCOUNT 181 select HAVE_CMPXCHG_DOUBLE 182 select HAVE_CMPXCHG_LOCAL 183 select HAVE_CONTEXT_TRACKING_USER 184 select HAVE_DEBUG_KMEMLEAK 185 select HAVE_DMA_CONTIGUOUS 186 select HAVE_DYNAMIC_FTRACE 187 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 188 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 189 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 190 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 191 if DYNAMIC_FTRACE_WITH_ARGS 192 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 193 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ 194 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 195 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 196 if DYNAMIC_FTRACE_WITH_ARGS 197 select HAVE_SAMPLE_FTRACE_DIRECT 198 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 199 select HAVE_BUILDTIME_MCOUNT_SORT 200 select HAVE_EFFICIENT_UNALIGNED_ACCESS 201 select HAVE_GUP_FAST 202 select HAVE_FTRACE_GRAPH_FUNC 203 select HAVE_FUNCTION_TRACER 204 select HAVE_FUNCTION_ERROR_INJECTION 205 select HAVE_FUNCTION_GRAPH_FREGS 206 select HAVE_FUNCTION_GRAPH_TRACER 207 select HAVE_GCC_PLUGINS 208 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 209 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 210 select HAVE_HW_BREAKPOINT if PERF_EVENTS 211 select HAVE_IOREMAP_PROT 212 select HAVE_IRQ_TIME_ACCOUNTING 213 select HAVE_LIVEPATCH 214 select HAVE_MOD_ARCH_SPECIFIC 215 select HAVE_NMI 216 select HAVE_PERF_EVENTS 217 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 218 select HAVE_PERF_REGS 219 select HAVE_PERF_USER_STACK_DUMP 220 select HAVE_PREEMPT_DYNAMIC_KEY 221 select HAVE_REGS_AND_STACK_ACCESS_API 222 select HAVE_RELIABLE_STACKTRACE 223 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 224 select HAVE_FUNCTION_ARG_ACCESS_API 225 select MMU_GATHER_RCU_TABLE_FREE 226 select HAVE_RSEQ 227 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 228 select HAVE_STACKPROTECTOR 229 select HAVE_STATIC_CALL if CFI 230 select HAVE_SYSCALL_TRACEPOINTS 231 select HAVE_KPROBES 232 select HAVE_KRETPROBES 233 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 234 select HOTPLUG_SMT if HOTPLUG_CPU 235 select IRQ_DOMAIN 236 select IRQ_FORCED_THREADING 237 select JUMP_LABEL 238 select KASAN_VMALLOC if KASAN 239 select LOCK_MM_AND_FIND_VMA 240 select MODULES_USE_ELF_RELA 241 select NEED_DMA_MAP_STATE 242 select NEED_SG_DMA_LENGTH 243 select OF 244 select OF_EARLY_FLATTREE 245 select PCI_DOMAINS_GENERIC if PCI 246 select PCI_ECAM if (ACPI && PCI) 247 select PCI_SYSCALL if PCI 248 select POWER_RESET 249 select POWER_SUPPLY 250 select HAS_SEPARATE_PREEMPT_RESCHED_BITS 251 select SPARSE_IRQ 252 select SWIOTLB 253 select SYSCTL_EXCEPTION_TRACE 254 select THREAD_INFO_IN_TASK 255 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 256 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 257 select TRACE_IRQFLAGS_SUPPORT 258 select TRACE_IRQFLAGS_NMI_SUPPORT 259 select HAVE_SOFTIRQ_ON_OWN_STACK 260 select USER_STACKTRACE_SUPPORT 261 select VDSO_GETRANDOM 262 select VMAP_STACK 263 help 264 ARM 64-bit (AArch64) Linux support. 265 266config RUSTC_SUPPORTS_ARM64 267 def_bool y 268 depends on CPU_LITTLE_ENDIAN 269 270config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 271 def_bool CC_IS_CLANG 272 # https://github.com/ClangBuiltLinux/linux/issues/1507 273 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 274 275config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 276 def_bool CC_IS_GCC 277 depends on $(cc-option,-fpatchable-function-entry=2) 278 279config 64BIT 280 def_bool y 281 282config MMU 283 def_bool y 284 285config ARM64_CONT_PTE_SHIFT 286 int 287 default 5 if PAGE_SIZE_64KB 288 default 7 if PAGE_SIZE_16KB 289 default 4 290 291config ARM64_CONT_PMD_SHIFT 292 int 293 default 5 if PAGE_SIZE_64KB 294 default 5 if PAGE_SIZE_16KB 295 default 4 296 297config ARCH_MMAP_RND_BITS_MIN 298 default 14 if PAGE_SIZE_64KB 299 default 16 if PAGE_SIZE_16KB 300 default 18 301 302# max bits determined by the following formula: 303# VA_BITS - PTDESC_TABLE_SHIFT 304config ARCH_MMAP_RND_BITS_MAX 305 default 19 if ARM64_VA_BITS=36 306 default 24 if ARM64_VA_BITS=39 307 default 27 if ARM64_VA_BITS=42 308 default 30 if ARM64_VA_BITS=47 309 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 310 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 311 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 312 default 14 if ARM64_64K_PAGES 313 default 16 if ARM64_16K_PAGES 314 default 18 315 316config ARCH_MMAP_RND_COMPAT_BITS_MIN 317 default 7 if ARM64_64K_PAGES 318 default 9 if ARM64_16K_PAGES 319 default 11 320 321config ARCH_MMAP_RND_COMPAT_BITS_MAX 322 default 16 323 324config NO_IOPORT_MAP 325 def_bool y if !PCI 326 327config STACKTRACE_SUPPORT 328 def_bool y 329 330config ILLEGAL_POINTER_VALUE 331 hex 332 default 0xdead000000000000 333 334config LOCKDEP_SUPPORT 335 def_bool y 336 337config GENERIC_BUG 338 def_bool y 339 depends on BUG 340 341config GENERIC_BUG_RELATIVE_POINTERS 342 def_bool y 343 depends on GENERIC_BUG 344 345config GENERIC_HWEIGHT 346 def_bool y 347 348config GENERIC_CSUM 349 def_bool y 350 351config GENERIC_CALIBRATE_DELAY 352 def_bool y 353 354config SMP 355 def_bool y 356 357config KERNEL_MODE_NEON 358 def_bool y 359 360config FIX_EARLYCON_MEM 361 def_bool y 362 363config PGTABLE_LEVELS 364 int 365 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 366 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 367 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 368 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 369 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 370 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 371 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 372 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 373 374config ARCH_SUPPORTS_UPROBES 375 def_bool y 376 377config ARCH_PROC_KCORE_TEXT 378 def_bool y 379 380config BROKEN_GAS_INST 381 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 382 383config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 384 bool 385 # Clang's __builtin_return_address() strips the PAC since 12.0.0 386 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 387 default y if CC_IS_CLANG 388 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 389 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 390 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 391 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 392 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 393 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 394 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 395 default n 396 397config KASAN_SHADOW_OFFSET 398 hex 399 depends on KASAN_GENERIC || KASAN_SW_TAGS 400 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 401 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 402 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 403 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 404 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 405 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 406 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 407 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 408 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 409 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 410 default 0xffffffffffffffff 411 412config UNWIND_TABLES 413 bool 414 415source "arch/arm64/Kconfig.platforms" 416 417menu "Kernel Features" 418 419menu "ARM errata workarounds via the alternatives framework" 420 421config AMPERE_ERRATUM_AC03_CPU_38 422 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 423 default y 424 help 425 This option adds an alternative code sequence to work around Ampere 426 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 427 428 The affected design reports FEAT_HAFDBS as not implemented in 429 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 430 as required by the architecture. The unadvertised HAFDBS 431 implementation suffers from an additional erratum where hardware 432 A/D updates can occur after a PTE has been marked invalid. 433 434 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 435 which avoids enabling unadvertised hardware Access Flag management 436 at stage-2. 437 438 If unsure, say Y. 439 440config AMPERE_ERRATUM_AC04_CPU_23 441 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 442 default y 443 help 444 This option adds an alternative code sequence to work around Ampere 445 errata AC04_CPU_23 on AmpereOne. 446 447 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 448 data addresses initiated by load/store instructions. Only 449 instruction initiated translations are vulnerable, not translations 450 from prefetches for example. A DSB before the store to HCR_EL2 is 451 sufficient to prevent older instructions from hitting the window 452 for corruption, and an ISB after is sufficient to prevent younger 453 instructions from hitting the window for corruption. 454 455 If unsure, say Y. 456 457config ARM64_WORKAROUND_CLEAN_CACHE 458 bool 459 460config ARM64_ERRATUM_826319 461 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 462 default y 463 select ARM64_WORKAROUND_CLEAN_CACHE 464 help 465 This option adds an alternative code sequence to work around ARM 466 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 467 AXI master interface and an L2 cache. 468 469 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 470 and is unable to accept a certain write via this interface, it will 471 not progress on read data presented on the read data channel and the 472 system can deadlock. 473 474 The workaround promotes data cache clean instructions to 475 data cache clean-and-invalidate. 476 Please note that this does not necessarily enable the workaround, 477 as it depends on the alternative framework, which will only patch 478 the kernel if an affected CPU is detected. 479 480 If unsure, say Y. 481 482config ARM64_ERRATUM_827319 483 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 484 default y 485 select ARM64_WORKAROUND_CLEAN_CACHE 486 help 487 This option adds an alternative code sequence to work around ARM 488 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 489 master interface and an L2 cache. 490 491 Under certain conditions this erratum can cause a clean line eviction 492 to occur at the same time as another transaction to the same address 493 on the AMBA 5 CHI interface, which can cause data corruption if the 494 interconnect reorders the two transactions. 495 496 The workaround promotes data cache clean instructions to 497 data cache clean-and-invalidate. 498 Please note that this does not necessarily enable the workaround, 499 as it depends on the alternative framework, which will only patch 500 the kernel if an affected CPU is detected. 501 502 If unsure, say Y. 503 504config ARM64_ERRATUM_824069 505 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 506 default y 507 select ARM64_WORKAROUND_CLEAN_CACHE 508 help 509 This option adds an alternative code sequence to work around ARM 510 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 511 to a coherent interconnect. 512 513 If a Cortex-A53 processor is executing a store or prefetch for 514 write instruction at the same time as a processor in another 515 cluster is executing a cache maintenance operation to the same 516 address, then this erratum might cause a clean cache line to be 517 incorrectly marked as dirty. 518 519 The workaround promotes data cache clean instructions to 520 data cache clean-and-invalidate. 521 Please note that this option does not necessarily enable the 522 workaround, as it depends on the alternative framework, which will 523 only patch the kernel if an affected CPU is detected. 524 525 If unsure, say Y. 526 527config ARM64_ERRATUM_819472 528 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 529 default y 530 select ARM64_WORKAROUND_CLEAN_CACHE 531 help 532 This option adds an alternative code sequence to work around ARM 533 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 534 present when it is connected to a coherent interconnect. 535 536 If the processor is executing a load and store exclusive sequence at 537 the same time as a processor in another cluster is executing a cache 538 maintenance operation to the same address, then this erratum might 539 cause data corruption. 540 541 The workaround promotes data cache clean instructions to 542 data cache clean-and-invalidate. 543 Please note that this does not necessarily enable the workaround, 544 as it depends on the alternative framework, which will only patch 545 the kernel if an affected CPU is detected. 546 547 If unsure, say Y. 548 549config ARM64_ERRATUM_832075 550 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 551 default y 552 help 553 This option adds an alternative code sequence to work around ARM 554 erratum 832075 on Cortex-A57 parts up to r1p2. 555 556 Affected Cortex-A57 parts might deadlock when exclusive load/store 557 instructions to Write-Back memory are mixed with Device loads. 558 559 The workaround is to promote device loads to use Load-Acquire 560 semantics. 561 Please note that this does not necessarily enable the workaround, 562 as it depends on the alternative framework, which will only patch 563 the kernel if an affected CPU is detected. 564 565 If unsure, say Y. 566 567config ARM64_ERRATUM_834220 568 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 569 depends on KVM 570 help 571 This option adds an alternative code sequence to work around ARM 572 erratum 834220 on Cortex-A57 parts up to r1p2. 573 574 Affected Cortex-A57 parts might report a Stage 2 translation 575 fault as the result of a Stage 1 fault for load crossing a 576 page boundary when there is a permission or device memory 577 alignment fault at Stage 1 and a translation fault at Stage 2. 578 579 The workaround is to verify that the Stage 1 translation 580 doesn't generate a fault before handling the Stage 2 fault. 581 Please note that this does not necessarily enable the workaround, 582 as it depends on the alternative framework, which will only patch 583 the kernel if an affected CPU is detected. 584 585 If unsure, say N. 586 587config ARM64_ERRATUM_1742098 588 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 589 depends on COMPAT 590 default y 591 help 592 This option removes the AES hwcap for aarch32 user-space to 593 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 594 595 Affected parts may corrupt the AES state if an interrupt is 596 taken between a pair of AES instructions. These instructions 597 are only present if the cryptography extensions are present. 598 All software should have a fallback implementation for CPUs 599 that don't implement the cryptography extensions. 600 601 If unsure, say Y. 602 603config ARM64_ERRATUM_845719 604 bool "Cortex-A53: 845719: a load might read incorrect data" 605 depends on COMPAT 606 default y 607 help 608 This option adds an alternative code sequence to work around ARM 609 erratum 845719 on Cortex-A53 parts up to r0p4. 610 611 When running a compat (AArch32) userspace on an affected Cortex-A53 612 part, a load at EL0 from a virtual address that matches the bottom 32 613 bits of the virtual address used by a recent load at (AArch64) EL1 614 might return incorrect data. 615 616 The workaround is to write the contextidr_el1 register on exception 617 return to a 32-bit task. 618 Please note that this does not necessarily enable the workaround, 619 as it depends on the alternative framework, which will only patch 620 the kernel if an affected CPU is detected. 621 622 If unsure, say Y. 623 624config ARM64_ERRATUM_843419 625 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 626 default y 627 help 628 This option links the kernel with '--fix-cortex-a53-843419' and 629 enables PLT support to replace certain ADRP instructions, which can 630 cause subsequent memory accesses to use an incorrect address on 631 Cortex-A53 parts up to r0p4. 632 633 If unsure, say Y. 634 635config ARM64_ERRATUM_1024718 636 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 637 default y 638 help 639 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 640 641 Affected Cortex-A55 cores (all revisions) could cause incorrect 642 update of the hardware dirty bit when the DBM/AP bits are updated 643 without a break-before-make. The workaround is to disable the usage 644 of hardware DBM locally on the affected cores. CPUs not affected by 645 this erratum will continue to use the feature. 646 647 If unsure, say Y. 648 649config ARM64_ERRATUM_1418040 650 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 651 default y 652 depends on COMPAT 653 help 654 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 655 errata 1188873 and 1418040. 656 657 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 658 cause register corruption when accessing the timer registers 659 from AArch32 userspace. 660 661 If unsure, say Y. 662 663config ARM64_WORKAROUND_SPECULATIVE_AT 664 bool 665 666config ARM64_ERRATUM_1165522 667 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 668 default y 669 select ARM64_WORKAROUND_SPECULATIVE_AT 670 help 671 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 672 673 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 674 corrupted TLBs by speculating an AT instruction during a guest 675 context switch. 676 677 If unsure, say Y. 678 679config ARM64_ERRATUM_1319367 680 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 681 default y 682 select ARM64_WORKAROUND_SPECULATIVE_AT 683 help 684 This option adds work arounds for ARM Cortex-A57 erratum 1319537 685 and A72 erratum 1319367 686 687 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 688 speculating an AT instruction during a guest context switch. 689 690 If unsure, say Y. 691 692config ARM64_ERRATUM_1530923 693 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 694 default y 695 select ARM64_WORKAROUND_SPECULATIVE_AT 696 help 697 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 698 699 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 700 corrupted TLBs by speculating an AT instruction during a guest 701 context switch. 702 703 If unsure, say Y. 704 705config ARM64_WORKAROUND_REPEAT_TLBI_SYNC 706 bool 707 # This workaround is (only) suitable for TLB invalidation errata where 708 # all of the following conditions are true: 709 # 710 # - The effects of the errata are only a loss of ordering/completion 711 # for explicit memory accesses when the TLBI is completed with a DSB. 712 # The removal of TLB entries is not affected. 713 # 714 # Note that architecturally, S2-only invalidation does not remove 715 # combined S1+S2 entries, and does not complete accesses translated 716 # via those S1+S2 entries. Consequently, where this condition holds, 717 # the errata do not affect S2-only invalidation. 718 # 719 # - The errata only affect broadcast TLB invalidation operations (e.g. 720 # TLBI VMALLE1IS), and do not affect local TLB invalidation 721 # operations (e.g. TLBI VMALLE1). 722 # 723 # - After any number of affected TLBI operations are completed with a 724 # DSB, the errata can be mitigated by executing a single arbitrary 725 # broadcast TLBI (which targets an arbitrary translation regime), 726 # followed by a DSB. 727 # 728 # For more rationale, see commit a8f78680ee6bf795. 729 730config ARM64_ERRATUM_2441007 731 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 732 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 733 help 734 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 735 736 Under very rare circumstances, affected Cortex-A55 CPUs 737 may not handle a race between a break-before-make sequence on one 738 CPU, and another CPU accessing the same page. This could allow a 739 store to a page that has been unmapped. 740 741 Work around this by adding the affected CPUs to the list that needs 742 TLB sequences to be done twice. 743 744 If unsure, say N. 745 746config ARM64_ERRATUM_1286807 747 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 748 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 749 help 750 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 751 752 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 753 address for a cacheable mapping of a location is being 754 accessed by a core while another core is remapping the virtual 755 address to a new physical page using the recommended 756 break-before-make sequence, then under very rare circumstances 757 TLBI+DSB completes before a read using the translation being 758 invalidated has been observed by other observers. The 759 workaround repeats the TLBI+DSB operation. 760 761 If unsure, say N. 762 763config ARM64_ERRATUM_1463225 764 bool "Cortex-A76: Software Step might prevent interrupt recognition" 765 default y 766 help 767 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 768 769 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 770 of a system call instruction (SVC) can prevent recognition of 771 subsequent interrupts when software stepping is disabled in the 772 exception handler of the system call and either kernel debugging 773 is enabled or VHE is in use. 774 775 Work around the erratum by triggering a dummy step exception 776 when handling a system call from a task that is being stepped 777 in a VHE configuration of the kernel. 778 779 If unsure, say Y. 780 781config ARM64_ERRATUM_1542419 782 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 783 help 784 This option adds a workaround for ARM Neoverse-N1 erratum 785 1542419. 786 787 Affected Neoverse-N1 cores could execute a stale instruction when 788 modified by another CPU. The workaround depends on a firmware 789 counterpart. 790 791 Workaround the issue by hiding the DIC feature from EL0. This 792 forces user-space to perform cache maintenance. 793 794 If unsure, say N. 795 796config ARM64_ERRATUM_1508412 797 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 798 default y 799 help 800 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 801 802 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 803 of a store-exclusive or read of PAR_EL1 and a load with device or 804 non-cacheable memory attributes. The workaround depends on a firmware 805 counterpart. 806 807 KVM guests must also have the workaround implemented or they can 808 deadlock the system. 809 810 Work around the issue by inserting DMB SY barriers around PAR_EL1 811 register reads and warning KVM users. The DMB barrier is sufficient 812 to prevent a speculative PAR_EL1 read. 813 814 If unsure, say Y. 815 816config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 817 bool 818 819config ARM64_ERRATUM_2051678 820 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 821 default y 822 help 823 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 824 Affected Cortex-A510 might not respect the ordering rules for 825 hardware update of the page table's dirty bit. The workaround 826 is to not enable the feature on affected CPUs. 827 828 If unsure, say Y. 829 830config ARM64_ERRATUM_2077057 831 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 832 default y 833 help 834 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 835 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 836 expected, but a Pointer Authentication trap is taken instead. The 837 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 838 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 839 840 This can only happen when EL2 is stepping EL1. 841 842 When these conditions occur, the SPSR_EL2 value is unchanged from the 843 previous guest entry, and can be restored from the in-memory copy. 844 845 If unsure, say Y. 846 847config ARM64_ERRATUM_2658417 848 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 849 default y 850 help 851 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 852 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 853 BFMMLA or VMMLA instructions in rare circumstances when a pair of 854 A510 CPUs are using shared neon hardware. As the sharing is not 855 discoverable by the kernel, hide the BF16 HWCAP to indicate that 856 user-space should not be using these instructions. 857 858 If unsure, say Y. 859 860config ARM64_ERRATUM_2119858 861 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 862 default y 863 depends on CORESIGHT_TRBE 864 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 865 help 866 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 867 868 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 869 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 870 the event of a WRAP event. 871 872 Work around the issue by always making sure we move the TRBPTR_EL1 by 873 256 bytes before enabling the buffer and filling the first 256 bytes of 874 the buffer with ETM ignore packets upon disabling. 875 876 If unsure, say Y. 877 878config ARM64_ERRATUM_2139208 879 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 880 default y 881 depends on CORESIGHT_TRBE 882 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 883 help 884 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 885 886 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 887 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 888 the event of a WRAP event. 889 890 Work around the issue by always making sure we move the TRBPTR_EL1 by 891 256 bytes before enabling the buffer and filling the first 256 bytes of 892 the buffer with ETM ignore packets upon disabling. 893 894 If unsure, say Y. 895 896config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 897 bool 898 899config ARM64_ERRATUM_2054223 900 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 901 default y 902 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 903 help 904 Enable workaround for ARM Cortex-A710 erratum 2054223 905 906 Affected cores may fail to flush the trace data on a TSB instruction, when 907 the PE is in trace prohibited state. This will cause losing a few bytes 908 of the trace cached. 909 910 Workaround is to issue two TSB consecutively on affected cores. 911 912 If unsure, say Y. 913 914config ARM64_ERRATUM_2067961 915 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 916 default y 917 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 918 help 919 Enable workaround for ARM Neoverse-N2 erratum 2067961 920 921 Affected cores may fail to flush the trace data on a TSB instruction, when 922 the PE is in trace prohibited state. This will cause losing a few bytes 923 of the trace cached. 924 925 Workaround is to issue two TSB consecutively on affected cores. 926 927 If unsure, say Y. 928 929config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 930 bool 931 932config ARM64_ERRATUM_2253138 933 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 934 depends on CORESIGHT_TRBE 935 default y 936 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 937 help 938 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 939 940 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 941 for TRBE. Under some conditions, the TRBE might generate a write to the next 942 virtually addressed page following the last page of the TRBE address space 943 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 944 945 Work around this in the driver by always making sure that there is a 946 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 947 948 If unsure, say Y. 949 950config ARM64_ERRATUM_2224489 951 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 952 depends on CORESIGHT_TRBE 953 default y 954 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 955 help 956 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 957 958 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 959 for TRBE. Under some conditions, the TRBE might generate a write to the next 960 virtually addressed page following the last page of the TRBE address space 961 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 962 963 Work around this in the driver by always making sure that there is a 964 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 965 966 If unsure, say Y. 967 968config ARM64_ERRATUM_2441009 969 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 970 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 971 help 972 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 973 974 Under very rare circumstances, affected Cortex-A510 CPUs 975 may not handle a race between a break-before-make sequence on one 976 CPU, and another CPU accessing the same page. This could allow a 977 store to a page that has been unmapped. 978 979 Work around this by adding the affected CPUs to the list that needs 980 TLB sequences to be done twice. 981 982 If unsure, say N. 983 984config ARM64_ERRATUM_2064142 985 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 986 depends on CORESIGHT_TRBE 987 default y 988 help 989 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 990 991 Affected Cortex-A510 core might fail to write into system registers after the 992 TRBE has been disabled. Under some conditions after the TRBE has been disabled 993 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 994 and TRBTRG_EL1 will be ignored and will not be effected. 995 996 Work around this in the driver by executing TSB CSYNC and DSB after collection 997 is stopped and before performing a system register write to one of the affected 998 registers. 999 1000 If unsure, say Y. 1001 1002config ARM64_ERRATUM_2038923 1003 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1004 depends on CORESIGHT_TRBE 1005 default y 1006 help 1007 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1008 1009 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1010 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1011 might be corrupted. This happens after TRBE buffer has been enabled by setting 1012 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1013 execution changes from a context, in which trace is prohibited to one where it 1014 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1015 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1016 the trace buffer state might be corrupted. 1017 1018 Work around this in the driver by preventing an inconsistent view of whether the 1019 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1020 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1021 two ISB instructions if no ERET is to take place. 1022 1023 If unsure, say Y. 1024 1025config ARM64_ERRATUM_1902691 1026 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1027 depends on CORESIGHT_TRBE 1028 default y 1029 help 1030 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1031 1032 Affected Cortex-A510 core might cause trace data corruption, when being written 1033 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1034 trace data. 1035 1036 Work around this problem in the driver by just preventing TRBE initialization on 1037 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1038 on such implementations. This will cover the kernel for any firmware that doesn't 1039 do this already. 1040 1041 If unsure, say Y. 1042 1043config ARM64_ERRATUM_2457168 1044 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1045 depends on ARM64_AMU_EXTN 1046 default y 1047 help 1048 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1049 1050 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1051 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1052 incorrectly giving a significantly higher output value. 1053 1054 Work around this problem by returning 0 when reading the affected counter in 1055 key locations that results in disabling all users of this counter. This effect 1056 is the same to firmware disabling affected counters. 1057 1058 If unsure, say Y. 1059 1060config ARM64_ERRATUM_2645198 1061 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1062 default y 1063 help 1064 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1065 1066 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1067 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1068 next instruction abort caused by permission fault. 1069 1070 Only user-space does executable to non-executable permission transition via 1071 mprotect() system call. Workaround the problem by doing a break-before-make 1072 TLB invalidation, for all changes to executable user space mappings. 1073 1074 If unsure, say Y. 1075 1076config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1077 bool 1078 1079config ARM64_ERRATUM_2966298 1080 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1081 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1082 default y 1083 help 1084 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1085 1086 On an affected Cortex-A520 core, a speculatively executed unprivileged 1087 load might leak data from a privileged level via a cache side channel. 1088 1089 Work around this problem by executing a TLBI before returning to EL0. 1090 1091 If unsure, say Y. 1092 1093config ARM64_ERRATUM_3117295 1094 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1095 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1096 default y 1097 help 1098 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1099 1100 On an affected Cortex-A510 core, a speculatively executed unprivileged 1101 load might leak data from a privileged level via a cache side channel. 1102 1103 Work around this problem by executing a TLBI before returning to EL0. 1104 1105 If unsure, say Y. 1106 1107config ARM64_ERRATUM_3194386 1108 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1109 default y 1110 help 1111 This option adds the workaround for the following errata: 1112 1113 * ARM Cortex-A76 erratum 3324349 1114 * ARM Cortex-A77 erratum 3324348 1115 * ARM Cortex-A78 erratum 3324344 1116 * ARM Cortex-A78C erratum 3324346 1117 * ARM Cortex-A78C erratum 3324347 1118 * ARM Cortex-A710 erratam 3324338 1119 * ARM Cortex-A715 errartum 3456084 1120 * ARM Cortex-A720 erratum 3456091 1121 * ARM Cortex-A725 erratum 3456106 1122 * ARM Cortex-X1 erratum 3324344 1123 * ARM Cortex-X1C erratum 3324346 1124 * ARM Cortex-X2 erratum 3324338 1125 * ARM Cortex-X3 erratum 3324335 1126 * ARM Cortex-X4 erratum 3194386 1127 * ARM Cortex-X925 erratum 3324334 1128 * ARM Neoverse-N1 erratum 3324349 1129 * ARM Neoverse N2 erratum 3324339 1130 * ARM Neoverse-N3 erratum 3456111 1131 * ARM Neoverse-V1 erratum 3324341 1132 * ARM Neoverse V2 erratum 3324336 1133 * ARM Neoverse-V3 erratum 3312417 1134 * ARM Neoverse-V3AE erratum 3312417 1135 1136 On affected cores "MSR SSBS, #0" instructions may not affect 1137 subsequent speculative instructions, which may permit unexepected 1138 speculative store bypassing. 1139 1140 Work around this problem by placing a Speculation Barrier (SB) or 1141 Instruction Synchronization Barrier (ISB) after kernel changes to 1142 SSBS. The presence of the SSBS special-purpose register is hidden 1143 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1144 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1145 1146 If unsure, say Y. 1147 1148config ARM64_ERRATUM_4311569 1149 bool "SI L1: 4311569: workaround for premature CMO completion erratum" 1150 default y 1151 help 1152 This option adds the workaround for ARM SI L1 erratum 4311569. 1153 1154 The erratum of SI L1 can cause an early response to a combined write 1155 and cache maintenance operation (WR+CMO) before the operation is fully 1156 completed to the Point of Serialization (POS). 1157 This can result in a non-I/O coherent agent observing stale data, 1158 potentially leading to system instability or incorrect behavior. 1159 1160 Enabling this option implements a software workaround by inserting a 1161 second loop of Cache Maintenance Operation (CMO) immediately following the 1162 end of function to do CMOs. This ensures that the data is correctly serialized 1163 before the buffer is handed off to a non-coherent agent. 1164 1165 If unsure, say Y. 1166 1167config ARM64_ERRATUM_4193714 1168 bool "C1-Pro: 4193714: SME DVMSync early acknowledgement" 1169 depends on ARM64_SME 1170 default y 1171 help 1172 Enable workaround for C1-Pro acknowledging the DVMSync before 1173 the SME memory accesses are complete. This will cause TLB 1174 maintenance for processes using SME to also issue an IPI to 1175 the affected CPUs. 1176 1177 If unsure, say Y. 1178 1179config ARM64_ERRATUM_4118414 1180 bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 1181 default y 1182 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 1183 help 1184 This option adds a workaround for the following errata: 1185 1186 * ARM C1-Premium erratum 4193780 1187 * ARM C1-Ultra erratum 4193780 1188 * ARM Cortex-A76 erratum 4193800 1189 * ARM Cortex-A76AE erratum 4193801 1190 * ARM Cortex-A77 erratum 4193798 1191 * ARM Cortex-A78 erratum 4193791 1192 * ARM Cortex-A78AE erratum 4193793 1193 * ARM Cortex-A78C erratum 4193794 1194 * ARM Cortex-A710 erratum 4193788 1195 * ARM Cortex-X1 erratum 4193791 1196 * ARM Cortex-X1C erratum 4193792 1197 * ARM Cortex-X2 erratum 4193788 1198 * ARM Cortex-X3 erratum 4193786 1199 * ARM Cortex-X4 erratum 4118414 1200 * ARM Cortex-X925 erratum 4193781 1201 * ARM Neoverse-N1 erratum 4193800 1202 * ARM Neoverse-N2 erratum 4193789 1203 * ARM Neoverse-V1 erratum 4193790 1204 * ARM Neoverse-V2 erratum 4193787 1205 * ARM Neoverse-V3 erratum 4193784 1206 * ARM Neoverse-V3AE erratum 4193784 1207 * Microsoft Azure Cobalt 100 4193789 1208 * NVIDIA Olympus erratum T410-OLY-1029 1209 1210 On affected cores, some memory accesses might not be completed by 1211 broadcast TLB invalidation. 1212 1213 This issue is also known as CVE-2025-10263. 1214 1215 If unsure, say Y. 1216 1217config CAVIUM_ERRATUM_22375 1218 bool "Cavium erratum 22375, 24313" 1219 default y 1220 help 1221 Enable workaround for errata 22375 and 24313. 1222 1223 This implements two gicv3-its errata workarounds for ThunderX. Both 1224 with a small impact affecting only ITS table allocation. 1225 1226 erratum 22375: only alloc 8MB table size 1227 erratum 24313: ignore memory access type 1228 1229 The fixes are in ITS initialization and basically ignore memory access 1230 type and table size provided by the TYPER and BASER registers. 1231 1232 If unsure, say Y. 1233 1234config CAVIUM_ERRATUM_23144 1235 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1236 depends on NUMA 1237 default y 1238 help 1239 ITS SYNC command hang for cross node io and collections/cpu mapping. 1240 1241 If unsure, say Y. 1242 1243config CAVIUM_ERRATUM_23154 1244 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1245 default y 1246 help 1247 The ThunderX GICv3 implementation requires a modified version for 1248 reading the IAR status to ensure data synchronization 1249 (access to icc_iar1_el1 is not sync'ed before and after). 1250 1251 It also suffers from erratum 38545 (also present on Marvell's 1252 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1253 spuriously presented to the CPU interface. 1254 1255 If unsure, say Y. 1256 1257config CAVIUM_ERRATUM_27456 1258 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1259 default y 1260 help 1261 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1262 instructions may cause the icache to become corrupted if it 1263 contains data for a non-current ASID. The fix is to 1264 invalidate the icache when changing the mm context. 1265 1266 If unsure, say Y. 1267 1268config CAVIUM_ERRATUM_30115 1269 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1270 default y 1271 help 1272 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1273 1.2, and T83 Pass 1.0, KVM guest execution may disable 1274 interrupts in host. Trapping both GICv3 group-0 and group-1 1275 accesses sidesteps the issue. 1276 1277 If unsure, say Y. 1278 1279config CAVIUM_TX2_ERRATUM_219 1280 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1281 default y 1282 help 1283 On Cavium ThunderX2, a load, store or prefetch instruction between a 1284 TTBR update and the corresponding context synchronizing operation can 1285 cause a spurious Data Abort to be delivered to any hardware thread in 1286 the CPU core. 1287 1288 Work around the issue by avoiding the problematic code sequence and 1289 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1290 trap handler performs the corresponding register access, skips the 1291 instruction and ensures context synchronization by virtue of the 1292 exception return. 1293 1294 If unsure, say Y. 1295 1296config FUJITSU_ERRATUM_010001 1297 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1298 default y 1299 help 1300 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1301 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1302 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1303 This fault occurs under a specific hardware condition when a 1304 load/store instruction performs an address translation using: 1305 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1306 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1307 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1308 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1309 1310 The workaround is to ensure these bits are clear in TCR_ELx. 1311 The workaround only affects the Fujitsu-A64FX. 1312 1313 If unsure, say Y. 1314 1315config HISILICON_ERRATUM_161600802 1316 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1317 default y 1318 help 1319 The HiSilicon Hip07 SoC uses the wrong redistributor base 1320 when issued ITS commands such as VMOVP and VMAPP, and requires 1321 a 128kB offset to be applied to the target address in this commands. 1322 1323 If unsure, say Y. 1324 1325config HISILICON_ERRATUM_162100801 1326 bool "Hip09 162100801 erratum support" 1327 default y 1328 help 1329 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1330 during unmapping operation, which will cause some vSGIs lost. 1331 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1332 after VMOVP. 1333 1334 If unsure, say Y. 1335 1336config HISILICON_ERRATUM_162100125 1337 bool "Hisilicon erratum 162100125" 1338 default y 1339 select ARM64_WORKAROUND_DISABLE_CNP 1340 help 1341 On HiSilicon HIP09, TLB entry matching behavior when CNP 1342 (TTBRx.CNP=1) is enabled differs from the ARM architecture 1343 specification. 1344 1345 TLB entries may be incorrectly shared between CPUs, potentially 1346 causing TLB conflicts and stale mappings. 1347 1348 Disable CNP support for affected HiSilicon HIP09 cores. 1349 1350 If unsure, say Y. 1351 1352config QCOM_FALKOR_ERRATUM_1003 1353 bool "Falkor E1003: Incorrect translation due to ASID change" 1354 default y 1355 help 1356 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1357 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1358 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1359 then only for entries in the walk cache, since the leaf translation 1360 is unchanged. Work around the erratum by invalidating the walk cache 1361 entries for the trampoline before entering the kernel proper. 1362 1363config QCOM_FALKOR_ERRATUM_1009 1364 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1365 default y 1366 select ARM64_WORKAROUND_REPEAT_TLBI_SYNC 1367 help 1368 On Falkor v1, the CPU may prematurely complete a DSB following a 1369 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1370 one more time to fix the issue. 1371 1372 If unsure, say Y. 1373 1374config QCOM_QDF2400_ERRATUM_0065 1375 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1376 default y 1377 help 1378 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1379 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1380 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1381 1382 If unsure, say Y. 1383 1384config QCOM_FALKOR_ERRATUM_E1041 1385 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1386 default y 1387 help 1388 Falkor CPU may speculatively fetch instructions from an improper 1389 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1390 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1391 1392 If unsure, say Y. 1393 1394config ARM64_WORKAROUND_DISABLE_CNP 1395 bool 1396 1397config NVIDIA_CARMEL_CNP_ERRATUM 1398 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1399 default y 1400 select ARM64_WORKAROUND_DISABLE_CNP 1401 help 1402 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1403 invalidate shared TLB entries installed by a different core, as it would 1404 on standard ARM cores. 1405 1406 If unsure, say Y. 1407 1408config NVIDIA_OLYMPUS_1027_ERRATUM 1409 bool "NVIDIA Olympus: device store/load ordering erratum" 1410 default y 1411 help 1412 This option adds an alternative code sequence to work around an 1413 NVIDIA Olympus core erratum where a Device-nGnR* store can be 1414 observed by a peripheral after a younger Device-nGnR* load to the 1415 same peripheral. This breaks the program order that drivers rely 1416 on for MMIO and can leave a device in an incorrect state. 1417 1418 The workaround inserts a DMB OSH immediately before raw MMIO loads. 1419 The erratum cannot occur when a DMB that orders loads appears 1420 between the store and load, preventing the younger load from being 1421 observed before the older store. 1422 1423 The alternatives framework patches in DMB OSH only when an affected 1424 CPU is detected. Other CPUs execute a NOP in its place. Disabling 1425 this option leaves the original MMIO read instruction stream 1426 unchanged. 1427 1428 If unsure, say Y. 1429 1430config RENESAS_ERRATUM_GEN4GICITS1 1431 bool "Renesas R-Car Gen4: GIC600 can not access physical addresses above 4 GiB" 1432 default y 1433 help 1434 The Renesas R-Car Gen4 S4/V4H/V4M GIC600 SoC integrations have AXI 1435 addressing limited to the first 32-bit of physical address space. 1436 1437 If unsure, say Y. 1438 1439config ROCKCHIP_ERRATUM_3568002 1440 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1441 default y 1442 help 1443 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1444 addressing limited to the first 32bit of physical address space. 1445 1446 If unsure, say Y. 1447 1448config ROCKCHIP_ERRATUM_3588001 1449 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1450 default y 1451 help 1452 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1453 This means, that its sharability feature may not be used, even though it 1454 is supported by the IP itself. 1455 1456 If unsure, say Y. 1457 1458config SOCIONEXT_SYNQUACER_PREITS 1459 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1460 default y 1461 help 1462 Socionext Synquacer SoCs implement a separate h/w block to generate 1463 MSI doorbell writes with non-zero values for the device ID. 1464 1465 If unsure, say Y. 1466 1467endmenu # "ARM errata workarounds via the alternatives framework" 1468 1469choice 1470 prompt "Page size" 1471 default ARM64_4K_PAGES 1472 help 1473 Page size (translation granule) configuration. 1474 1475config ARM64_4K_PAGES 1476 bool "4KB" 1477 select HAVE_PAGE_SIZE_4KB 1478 help 1479 This feature enables 4KB pages support. 1480 1481config ARM64_16K_PAGES 1482 bool "16KB" 1483 select HAVE_PAGE_SIZE_16KB 1484 help 1485 The system will use 16KB pages support. AArch32 emulation 1486 requires applications compiled with 16K (or a multiple of 16K) 1487 aligned segments. 1488 1489config ARM64_64K_PAGES 1490 bool "64KB" 1491 select HAVE_PAGE_SIZE_64KB 1492 help 1493 This feature enables 64KB pages support (4KB by default) 1494 allowing only two levels of page tables and faster TLB 1495 look-up. AArch32 emulation requires applications compiled 1496 with 64K aligned segments. 1497 1498endchoice 1499 1500choice 1501 prompt "Virtual address space size" 1502 default ARM64_VA_BITS_52 1503 help 1504 Allows choosing one of multiple possible virtual address 1505 space sizes. The level of translation table is determined by 1506 a combination of page size and virtual address space size. 1507 1508config ARM64_VA_BITS_36 1509 bool "36-bit" if EXPERT 1510 depends on PAGE_SIZE_16KB 1511 1512config ARM64_VA_BITS_39 1513 bool "39-bit" 1514 depends on PAGE_SIZE_4KB 1515 1516config ARM64_VA_BITS_42 1517 bool "42-bit" 1518 depends on PAGE_SIZE_64KB 1519 1520config ARM64_VA_BITS_47 1521 bool "47-bit" 1522 depends on PAGE_SIZE_16KB 1523 1524config ARM64_VA_BITS_48 1525 bool "48-bit" 1526 1527config ARM64_VA_BITS_52 1528 bool "52-bit" 1529 help 1530 Enable 52-bit virtual addressing for userspace when explicitly 1531 requested via a hint to mmap(). The kernel will also use 52-bit 1532 virtual addresses for its own mappings (provided HW support for 1533 this feature is available, otherwise it reverts to 48-bit). 1534 1535 NOTE: Enabling 52-bit virtual addressing in conjunction with 1536 ARMv8.3 Pointer Authentication will result in the PAC being 1537 reduced from 7 bits to 3 bits, which may have a significant 1538 impact on its susceptibility to brute-force attacks. 1539 1540 If unsure, select 48-bit virtual addressing instead. 1541 1542endchoice 1543 1544config ARM64_FORCE_52BIT 1545 bool "Force 52-bit virtual addresses for userspace" 1546 depends on ARM64_VA_BITS_52 && EXPERT 1547 help 1548 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1549 to maintain compatibility with older software by providing 48-bit VAs 1550 unless a hint is supplied to mmap. 1551 1552 This configuration option disables the 48-bit compatibility logic, and 1553 forces all userspace addresses to be 52-bit on HW that supports it. One 1554 should only enable this configuration option for stress testing userspace 1555 memory management code. If unsure say N here. 1556 1557config ARM64_VA_BITS 1558 int 1559 default 36 if ARM64_VA_BITS_36 1560 default 39 if ARM64_VA_BITS_39 1561 default 42 if ARM64_VA_BITS_42 1562 default 47 if ARM64_VA_BITS_47 1563 default 48 if ARM64_VA_BITS_48 1564 default 52 if ARM64_VA_BITS_52 1565 1566choice 1567 prompt "Physical address space size" 1568 default ARM64_PA_BITS_48 1569 help 1570 Choose the maximum physical address range that the kernel will 1571 support. 1572 1573config ARM64_PA_BITS_48 1574 bool "48-bit" 1575 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1576 1577config ARM64_PA_BITS_52 1578 bool "52-bit" 1579 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1580 help 1581 Enable support for a 52-bit physical address space, introduced as 1582 part of the ARMv8.2-LPA extension. 1583 1584 With this enabled, the kernel will also continue to work on CPUs that 1585 do not support ARMv8.2-LPA, but with some added memory overhead (and 1586 minor performance overhead). 1587 1588endchoice 1589 1590config ARM64_PA_BITS 1591 int 1592 default 48 if ARM64_PA_BITS_48 1593 default 52 if ARM64_PA_BITS_52 1594 1595config ARM64_LPA2 1596 def_bool y 1597 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1598 1599choice 1600 prompt "Endianness" 1601 default CPU_LITTLE_ENDIAN 1602 help 1603 Select the endianness of data accesses performed by the CPU. Userspace 1604 applications will need to be compiled and linked for the endianness 1605 that is selected here. 1606 1607config CPU_BIG_ENDIAN 1608 bool "Build big-endian kernel" 1609 depends on BROKEN 1610 help 1611 Say Y if you plan on running a kernel with a big-endian userspace. 1612 1613config CPU_LITTLE_ENDIAN 1614 bool "Build little-endian kernel" 1615 help 1616 Say Y if you plan on running a kernel with a little-endian userspace. 1617 This is usually the case for distributions targeting arm64. 1618 1619endchoice 1620 1621config NR_CPUS 1622 int "Maximum number of CPUs (2-4096)" 1623 range 2 4096 1624 default "512" 1625 1626config HOTPLUG_CPU 1627 bool "Support for hot-pluggable CPUs" 1628 select GENERIC_IRQ_MIGRATION 1629 help 1630 Say Y here to experiment with turning CPUs off and on. CPUs 1631 can be controlled through /sys/devices/system/cpu. 1632 1633# Common NUMA Features 1634config NUMA 1635 bool "NUMA Memory Allocation and Scheduler Support" 1636 select GENERIC_ARCH_NUMA 1637 select OF_NUMA 1638 select HAVE_SETUP_PER_CPU_AREA 1639 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1640 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1641 select USE_PERCPU_NUMA_NODE_ID 1642 help 1643 Enable NUMA (Non-Uniform Memory Access) support. 1644 1645 The kernel will try to allocate memory used by a CPU on the 1646 local memory of the CPU and add some more 1647 NUMA awareness to the kernel. 1648 1649config NODES_SHIFT 1650 int "Maximum NUMA Nodes (as a power of 2)" 1651 range 1 10 1652 default "4" 1653 depends on NUMA 1654 help 1655 Specify the maximum number of NUMA Nodes available on the target 1656 system. Increases memory reserved to accommodate various tables. 1657 1658source "kernel/Kconfig.hz" 1659 1660config ARCH_SPARSEMEM_ENABLE 1661 def_bool y 1662 select SPARSEMEM_VMEMMAP_ENABLE 1663 1664config HW_PERF_EVENTS 1665 def_bool y 1666 depends on ARM_PMU 1667 1668# Supported by clang >= 7.0 or GCC >= 12.0.0 1669config CC_HAVE_SHADOW_CALL_STACK 1670 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1671 1672config PARAVIRT 1673 bool "Enable paravirtualization code" 1674 select HAVE_PV_STEAL_CLOCK_GEN 1675 help 1676 This changes the kernel so it can modify itself when it is run 1677 under a hypervisor, potentially improving performance significantly 1678 over full virtualization. 1679 1680config PARAVIRT_TIME_ACCOUNTING 1681 bool "Paravirtual steal time accounting" 1682 select PARAVIRT 1683 help 1684 Select this option to enable fine granularity task steal time 1685 accounting. Time spent executing other tasks in parallel with 1686 the current vCPU is discounted from the vCPU power. To account for 1687 that, there can be a small performance impact. 1688 1689 If in doubt, say N here. 1690 1691config ARCH_SUPPORTS_KEXEC 1692 def_bool PM_SLEEP_SMP 1693 1694config ARCH_SUPPORTS_KEXEC_FILE 1695 def_bool y 1696 1697config ARCH_SELECTS_KEXEC_FILE 1698 def_bool y 1699 depends on KEXEC_FILE 1700 select HAVE_IMA_KEXEC if IMA 1701 1702config ARCH_SUPPORTS_KEXEC_SIG 1703 def_bool y 1704 1705config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1706 def_bool y 1707 1708config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1709 def_bool y 1710 1711config ARCH_SUPPORTS_KEXEC_HANDOVER 1712 def_bool y 1713 1714config ARCH_SUPPORTS_CRASH_DUMP 1715 def_bool y 1716 1717config ARCH_DEFAULT_CRASH_DUMP 1718 def_bool y 1719 1720config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1721 def_bool CRASH_RESERVE 1722 1723config TRANS_TABLE 1724 def_bool y 1725 depends on HIBERNATION || KEXEC_CORE 1726 1727config XEN_DOM0 1728 def_bool y 1729 depends on XEN 1730 1731config XEN 1732 bool "Xen guest support on ARM64" 1733 depends on ARM64 && OF 1734 select SWIOTLB_XEN 1735 select PARAVIRT 1736 help 1737 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1738 1739# include/linux/mmzone.h requires the following to be true: 1740# 1741# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1742# 1743# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1744# 1745# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1746# ----+-------------------+--------------+----------------------+-------------------------+ 1747# 4K | 27 | 12 | 15 | 10 | 1748# 16K | 27 | 14 | 13 | 11 | 1749# 64K | 29 | 16 | 13 | 13 | 1750config ARCH_FORCE_MAX_ORDER 1751 int 1752 default "13" if ARM64_64K_PAGES 1753 default "11" if ARM64_16K_PAGES 1754 default "10" 1755 help 1756 The kernel page allocator limits the size of maximal physically 1757 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1758 defines the maximal power of two of number of pages that can be 1759 allocated as a single contiguous block. This option allows 1760 overriding the default setting when ability to allocate very 1761 large blocks of physically contiguous memory is required. 1762 1763 The maximal size of allocation cannot exceed the size of the 1764 section, so the value of MAX_PAGE_ORDER should satisfy 1765 1766 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1767 1768 Don't change if unsure. 1769 1770config UNMAP_KERNEL_AT_EL0 1771 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1772 default y 1773 help 1774 Speculation attacks against some high-performance processors can 1775 be used to bypass MMU permission checks and leak kernel data to 1776 userspace. This can be defended against by unmapping the kernel 1777 when running in userspace, mapping it back in on exception entry 1778 via a trampoline page in the vector table. 1779 1780 If unsure, say Y. 1781 1782config MITIGATE_SPECTRE_BRANCH_HISTORY 1783 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1784 default y 1785 help 1786 Speculation attacks against some high-performance processors can 1787 make use of branch history to influence future speculation. 1788 When taking an exception from user-space, a sequence of branches 1789 or a firmware call overwrites the branch history. 1790 1791config ARM64_SW_TTBR0_PAN 1792 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1793 depends on !KCSAN 1794 help 1795 Enabling this option prevents the kernel from accessing 1796 user-space memory directly by pointing TTBR0_EL1 to a reserved 1797 zeroed area and reserved ASID. The user access routines 1798 restore the valid TTBR0_EL1 temporarily. 1799 1800config ARM64_TAGGED_ADDR_ABI 1801 bool "Enable the tagged user addresses syscall ABI" 1802 default y 1803 help 1804 When this option is enabled, user applications can opt in to a 1805 relaxed ABI via prctl() allowing tagged addresses to be passed 1806 to system calls as pointer arguments. For details, see 1807 Documentation/arch/arm64/tagged-address-abi.rst. 1808 1809menuconfig COMPAT 1810 bool "Kernel support for 32-bit EL0" 1811 depends on ARM64_4K_PAGES || EXPERT 1812 select HAVE_UID16 1813 select OLD_SIGSUSPEND3 1814 select COMPAT_OLD_SIGACTION 1815 help 1816 This option enables support for a 32-bit EL0 running under a 64-bit 1817 kernel at EL1. AArch32-specific components such as system calls, 1818 the user helper functions, VFP support and the ptrace interface are 1819 handled appropriately by the kernel. 1820 1821 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1822 that you will only be able to execute AArch32 binaries that were compiled 1823 with page size aligned segments. 1824 1825 If you want to execute 32-bit userspace applications, say Y. 1826 1827if COMPAT 1828 1829config KUSER_HELPERS 1830 bool "Enable kuser helpers page for 32-bit applications" 1831 default y 1832 help 1833 Warning: disabling this option may break 32-bit user programs. 1834 1835 Provide kuser helpers to compat tasks. The kernel provides 1836 helper code to userspace in read only form at a fixed location 1837 to allow userspace to be independent of the CPU type fitted to 1838 the system. This permits binaries to be run on ARMv4 through 1839 to ARMv8 without modification. 1840 1841 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1842 1843 However, the fixed address nature of these helpers can be used 1844 by ROP (return orientated programming) authors when creating 1845 exploits. 1846 1847 If all of the binaries and libraries which run on your platform 1848 are built specifically for your platform, and make no use of 1849 these helpers, then you can turn this option off to hinder 1850 such exploits. However, in that case, if a binary or library 1851 relying on those helpers is run, it will not function correctly. 1852 1853 Say N here only if you are absolutely certain that you do not 1854 need these helpers; otherwise, the safe option is to say Y. 1855 1856config COMPAT_VDSO 1857 bool "Enable vDSO for 32-bit applications" 1858 depends on !CPU_BIG_ENDIAN 1859 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1860 default y 1861 help 1862 Place in the process address space of 32-bit applications an 1863 ELF shared object providing fast implementations of gettimeofday 1864 and clock_gettime. 1865 1866 You must have a 32-bit build of glibc 2.22 or later for programs 1867 to seamlessly take advantage of this. 1868 1869config THUMB2_COMPAT_VDSO 1870 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1871 depends on COMPAT_VDSO 1872 default y 1873 help 1874 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1875 otherwise with '-marm'. 1876 1877config COMPAT_ALIGNMENT_FIXUPS 1878 bool "Fix up misaligned multi-word loads and stores in user space" 1879 1880menuconfig ARMV8_DEPRECATED 1881 bool "Emulate deprecated/obsolete ARMv8 instructions" 1882 depends on SYSCTL 1883 help 1884 Legacy software support may require certain instructions 1885 that have been deprecated or obsoleted in the architecture. 1886 1887 Enable this config to enable selective emulation of these 1888 features. 1889 1890 If unsure, say Y 1891 1892if ARMV8_DEPRECATED 1893 1894config SWP_EMULATION 1895 bool "Emulate SWP/SWPB instructions" 1896 help 1897 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1898 they are always undefined. Say Y here to enable software 1899 emulation of these instructions for userspace using LDXR/STXR. 1900 This feature can be controlled at runtime with the abi.swp 1901 sysctl which is disabled by default. 1902 1903 In some older versions of glibc [<=2.8] SWP is used during futex 1904 trylock() operations with the assumption that the code will not 1905 be preempted. This invalid assumption may be more likely to fail 1906 with SWP emulation enabled, leading to deadlock of the user 1907 application. 1908 1909 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1910 on an external transaction monitoring block called a global 1911 monitor to maintain update atomicity. If your system does not 1912 implement a global monitor, this option can cause programs that 1913 perform SWP operations to uncached memory to deadlock. 1914 1915 If unsure, say Y 1916 1917config CP15_BARRIER_EMULATION 1918 bool "Emulate CP15 Barrier instructions" 1919 help 1920 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1921 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1922 strongly recommended to use the ISB, DSB, and DMB 1923 instructions instead. 1924 1925 Say Y here to enable software emulation of these 1926 instructions for AArch32 userspace code. When this option is 1927 enabled, CP15 barrier usage is traced which can help 1928 identify software that needs updating. This feature can be 1929 controlled at runtime with the abi.cp15_barrier sysctl. 1930 1931 If unsure, say Y 1932 1933config SETEND_EMULATION 1934 bool "Emulate SETEND instruction" 1935 help 1936 The SETEND instruction alters the data-endianness of the 1937 AArch32 EL0, and is deprecated in ARMv8. 1938 1939 Say Y here to enable software emulation of the instruction 1940 for AArch32 userspace code. This feature can be controlled 1941 at runtime with the abi.setend sysctl. 1942 1943 Note: All the cpus on the system must have mixed endian support at EL0 1944 for this feature to be enabled. If a new CPU - which doesn't support mixed 1945 endian - is hotplugged in after this feature has been enabled, there could 1946 be unexpected results in the applications. 1947 1948 If unsure, say Y 1949endif # ARMV8_DEPRECATED 1950 1951endif # COMPAT 1952 1953menu "ARMv8.1 architectural features" 1954 1955config ARM64_HW_AFDBM 1956 bool "Support for hardware updates of the Access and Dirty page flags" 1957 default y 1958 help 1959 The ARMv8.1 architecture extensions introduce support for 1960 hardware updates of the access and dirty information in page 1961 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1962 capable processors, accesses to pages with PTE_AF cleared will 1963 set this bit instead of raising an access flag fault. 1964 Similarly, writes to read-only pages with the DBM bit set will 1965 clear the read-only bit (AP[2]) instead of raising a 1966 permission fault. 1967 1968 Kernels built with this configuration option enabled continue 1969 to work on pre-ARMv8.1 hardware and the performance impact is 1970 minimal. If unsure, say Y. 1971 1972endmenu # "ARMv8.1 architectural features" 1973 1974menu "ARMv8.2 architectural features" 1975 1976config ARM64_PMEM 1977 bool "Enable support for persistent memory" 1978 select ARCH_HAS_PMEM_API 1979 select ARCH_HAS_UACCESS_FLUSHCACHE 1980 help 1981 Say Y to enable support for the persistent memory API based on the 1982 ARMv8.2 DCPoP feature. 1983 1984 The feature is detected at runtime, and the kernel will use DC CVAC 1985 operations if DC CVAP is not supported (following the behaviour of 1986 DC CVAP itself if the system does not define a point of persistence). 1987 1988config ARM64_RAS_EXTN 1989 bool "Enable support for RAS CPU Extensions" 1990 default y 1991 help 1992 CPUs that support the Reliability, Availability and Serviceability 1993 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1994 errors, classify them and report them to software. 1995 1996 On CPUs with these extensions system software can use additional 1997 barriers to determine if faults are pending and read the 1998 classification from a new set of registers. 1999 2000 Selecting this feature will allow the kernel to use these barriers 2001 and access the new registers if the system supports the extension. 2002 Platform RAS features may additionally depend on firmware support. 2003 2004config ARM64_CNP 2005 bool "Enable support for Common Not Private (CNP) translations" 2006 default y 2007 help 2008 Common Not Private (CNP) allows translation table entries to 2009 be shared between different PEs in the same inner shareable 2010 domain, so the hardware can use this fact to optimise the 2011 caching of such entries in the TLB. 2012 2013 Selecting this option allows the CNP feature to be detected 2014 at runtime, and does not affect PEs that do not implement 2015 this feature. 2016 2017endmenu # "ARMv8.2 architectural features" 2018 2019menu "ARMv8.3 architectural features" 2020 2021config ARM64_PTR_AUTH 2022 bool "Enable support for pointer authentication" 2023 default y 2024 help 2025 Pointer authentication (part of the ARMv8.3 Extensions) provides 2026 instructions for signing and authenticating pointers against secret 2027 keys, which can be used to mitigate Return Oriented Programming (ROP) 2028 and other attacks. 2029 2030 This option enables these instructions at EL0 (i.e. for userspace). 2031 Choosing this option will cause the kernel to initialise secret keys 2032 for each process at exec() time, with these keys being 2033 context-switched along with the process. 2034 2035 The feature is detected at runtime. If the feature is not present in 2036 hardware it will not be advertised to userspace/KVM guest nor will it 2037 be enabled. 2038 2039 If the feature is present on the boot CPU but not on a late CPU, then 2040 the late CPU will be parked. Also, if the boot CPU does not have 2041 address auth and the late CPU has then the late CPU will still boot 2042 but with the feature disabled. On such a system, this option should 2043 not be selected. 2044 2045config ARM64_PTR_AUTH_KERNEL 2046 bool "Use pointer authentication for kernel" 2047 default y 2048 depends on ARM64_PTR_AUTH 2049 # Modern compilers insert a .note.gnu.property section note for PAC 2050 # which is only understood by binutils starting with version 2.33.1. 2051 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2052 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2053 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2054 help 2055 If the compiler supports the -mbranch-protection or 2056 -msign-return-address flag (e.g. GCC 7 or later), then this option 2057 will cause the kernel itself to be compiled with return address 2058 protection. In this case, and if the target hardware is known to 2059 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2060 disabled with minimal loss of protection. 2061 2062 This feature works with FUNCTION_GRAPH_TRACER option only if 2063 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2064 2065config CC_HAS_BRANCH_PROT_PAC_RET 2066 # GCC 9 or later, clang 8 or later 2067 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2068 2069config AS_HAS_CFI_NEGATE_RA_STATE 2070 # binutils 2.34+ 2071 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2072 2073endmenu # "ARMv8.3 architectural features" 2074 2075menu "ARMv8.4 architectural features" 2076 2077config ARM64_AMU_EXTN 2078 bool "Enable support for the Activity Monitors Unit CPU extension" 2079 default y 2080 help 2081 The activity monitors extension is an optional extension introduced 2082 by the ARMv8.4 CPU architecture. This enables support for version 1 2083 of the activity monitors architecture, AMUv1. 2084 2085 To enable the use of this extension on CPUs that implement it, say Y. 2086 2087 Note that for architectural reasons, firmware _must_ implement AMU 2088 support when running on CPUs that present the activity monitors 2089 extension. The required support is present in: 2090 * Version 1.5 and later of the ARM Trusted Firmware 2091 2092 For kernels that have this configuration enabled but boot with broken 2093 firmware, you may need to say N here until the firmware is fixed. 2094 Otherwise you may experience firmware panics or lockups when 2095 accessing the counter registers. Even if you are not observing these 2096 symptoms, the values returned by the register reads might not 2097 correctly reflect reality. Most commonly, the value read will be 0, 2098 indicating that the counter is not enabled. 2099 2100config ARM64_TLB_RANGE 2101 bool "Enable support for tlbi range feature" 2102 default y 2103 help 2104 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2105 range of input addresses. 2106 2107config ARM64_MPAM 2108 bool "Enable support for MPAM" 2109 select ARM64_MPAM_DRIVER 2110 select ARCH_HAS_CPU_RESCTRL 2111 help 2112 Memory System Resource Partitioning and Monitoring (MPAM) is an 2113 optional extension to the Arm architecture that allows each 2114 transaction issued to the memory system to be labelled with a 2115 Partition identifier (PARTID) and Performance Monitoring Group 2116 identifier (PMG). 2117 2118 Memory system components, such as the caches, can be configured with 2119 policies to control how much of various physical resources (such as 2120 memory bandwidth or cache memory) the transactions labelled with each 2121 PARTID can consume. Depending on the capabilities of the hardware, 2122 the PARTID and PMG can also be used as filtering criteria to measure 2123 the memory system resource consumption of different parts of a 2124 workload. 2125 2126 Use of this extension requires CPU support, support in the 2127 Memory System Components (MSC), and a description from firmware 2128 of where the MSCs are in the address space. 2129 2130 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2131 2132 This option enables the extra context switch code. 2133 2134endmenu # "ARMv8.4 architectural features" 2135 2136menu "ARMv8.5 architectural features" 2137 2138config AS_HAS_ARMV8_5 2139 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2140 2141config ARM64_BTI 2142 bool "Branch Target Identification support" 2143 default y 2144 help 2145 Branch Target Identification (part of the ARMv8.5 Extensions) 2146 provides a mechanism to limit the set of locations to which computed 2147 branch instructions such as BR or BLR can jump. 2148 2149 To make use of BTI on CPUs that support it, say Y. 2150 2151 BTI is intended to provide complementary protection to other control 2152 flow integrity protection mechanisms, such as the Pointer 2153 authentication mechanism provided as part of the ARMv8.3 Extensions. 2154 For this reason, it does not make sense to enable this option without 2155 also enabling support for pointer authentication. Thus, when 2156 enabling this option you should also select ARM64_PTR_AUTH=y. 2157 2158 Userspace binaries must also be specifically compiled to make use of 2159 this mechanism. If you say N here or the hardware does not support 2160 BTI, such binaries can still run, but you get no additional 2161 enforcement of branch destinations. 2162 2163config ARM64_BTI_KERNEL 2164 bool "Use Branch Target Identification for kernel" 2165 default y 2166 depends on ARM64_BTI 2167 depends on ARM64_PTR_AUTH_KERNEL 2168 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2169 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2170 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2171 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2172 depends on !CC_IS_GCC 2173 # https://github.com/llvm/llvm-project/issues/215547 2174 depends on !CC_IS_CLANG || CLANG_VERSION < 210000 2175 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2176 help 2177 Build the kernel with Branch Target Identification annotations 2178 and enable enforcement of this for kernel code. When this option 2179 is enabled and the system supports BTI all kernel code including 2180 modular code must have BTI enabled. 2181 2182config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2183 # GCC 9 or later, clang 8 or later 2184 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2185 2186config ARM64_E0PD 2187 bool "Enable support for E0PD" 2188 default y 2189 help 2190 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2191 that EL0 accesses made via TTBR1 always fault in constant time, 2192 providing similar benefits to KASLR as those provided by KPTI, but 2193 with lower overhead and without disrupting legitimate access to 2194 kernel memory such as SPE. 2195 2196 This option enables E0PD for TTBR1 where available. 2197 2198config ARM64_AS_HAS_MTE 2199 # Initial support for MTE went in binutils 2.32.0, checked with 2200 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2201 # as a late addition to the final architecture spec (LDGM/STGM) 2202 # is only supported in the newer 2.32.x and 2.33 binutils 2203 # versions, hence the extra "stgm" instruction check below. 2204 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2205 2206config ARM64_MTE 2207 bool "Memory Tagging Extension support" 2208 default y 2209 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2210 depends on AS_HAS_ARMV8_5 2211 # Required for tag checking in the uaccess routines 2212 select ARCH_HAS_SUBPAGE_FAULTS 2213 select ARCH_USES_HIGH_VMA_FLAGS 2214 select ARCH_USES_PG_ARCH_2 2215 select ARCH_USES_PG_ARCH_3 2216 help 2217 Memory Tagging (part of the ARMv8.5 Extensions) provides 2218 architectural support for run-time, always-on detection of 2219 various classes of memory error to aid with software debugging 2220 to eliminate vulnerabilities arising from memory-unsafe 2221 languages. 2222 2223 This option enables the support for the Memory Tagging 2224 Extension at EL0 (i.e. for userspace). 2225 2226 Selecting this option allows the feature to be detected at 2227 runtime. Any secondary CPU not implementing this feature will 2228 not be allowed a late bring-up. 2229 2230 Userspace binaries that want to use this feature must 2231 explicitly opt in. The mechanism for the userspace is 2232 described in: 2233 2234 Documentation/arch/arm64/memory-tagging-extension.rst. 2235 2236endmenu # "ARMv8.5 architectural features" 2237 2238menu "ARMv8.7 architectural features" 2239 2240config ARM64_EPAN 2241 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2242 default y 2243 help 2244 Enhanced Privileged Access Never (EPAN) allows Privileged 2245 Access Never to be used with Execute-only mappings. 2246 2247 The feature is detected at runtime, and will remain disabled 2248 if the cpu does not implement the feature. 2249endmenu # "ARMv8.7 architectural features" 2250 2251config AS_HAS_MOPS 2252 def_bool $(as-instr,.arch_extension mops) 2253 2254menu "ARMv8.9 architectural features" 2255 2256config ARM64_POE 2257 prompt "Permission Overlay Extension" 2258 def_bool y 2259 select ARCH_USES_HIGH_VMA_FLAGS 2260 select ARCH_HAS_PKEYS 2261 help 2262 The Permission Overlay Extension is used to implement Memory 2263 Protection Keys. Memory Protection Keys provides a mechanism for 2264 enforcing page-based protections, but without requiring modification 2265 of the page tables when an application changes protection domains. 2266 2267 For details, see Documentation/core-api/protection-keys.rst 2268 2269 If unsure, say y. 2270 2271config ARCH_PKEY_BITS 2272 int 2273 default 3 2274 2275config ARM64_HAFT 2276 bool "Support for Hardware managed Access Flag for Table Descriptors" 2277 depends on ARM64_HW_AFDBM 2278 default y 2279 help 2280 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2281 Flag for Table descriptors. When enabled an architectural executed 2282 memory access will update the Access Flag in each Table descriptor 2283 which is accessed during the translation table walk and for which 2284 the Access Flag is 0. The Access Flag of the Table descriptor use 2285 the same bit of PTE_AF. 2286 2287 The feature will only be enabled if all the CPUs in the system 2288 support this feature. If unsure, say Y. 2289 2290endmenu # "ARMv8.9 architectural features" 2291 2292menu "ARMv9.4 architectural features" 2293 2294config ARM64_GCS 2295 bool "Enable support for Guarded Control Stack (GCS)" 2296 default y 2297 select ARCH_HAS_USER_SHADOW_STACK 2298 select ARCH_USES_HIGH_VMA_FLAGS 2299 help 2300 Guarded Control Stack (GCS) provides support for a separate 2301 stack with restricted access which contains only return 2302 addresses. This can be used to harden against some attacks 2303 by comparing return address used by the program with what is 2304 stored in the GCS, and may also be used to efficiently obtain 2305 the call stack for applications such as profiling. 2306 2307 The feature is detected at runtime, and will remain disabled 2308 if the system does not implement the feature. 2309 2310endmenu # "ARMv9.4 architectural features" 2311 2312config AS_HAS_LSUI 2313 def_bool $(as-instr,.arch_extension lsui) 2314 help 2315 Supported by LLVM 20+ and binutils 2.45+. 2316 2317menu "ARMv9.6 architectural features" 2318 2319config ARM64_LSUI 2320 bool "Support Unprivileged Load Store Instructions (LSUI)" 2321 default y 2322 depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN 2323 help 2324 The Unprivileged Load Store Instructions (LSUI) provides 2325 variants load/store instructions that access user-space memory 2326 from the kernel without clearing PSTATE.PAN bit. 2327 2328 This feature is supported by LLVM 20+ and binutils 2.45+. 2329 2330endmenu # "ARMv9.6 architectural feature" 2331 2332config ARM64_SVE 2333 bool "ARM Scalable Vector Extension support" 2334 default y 2335 help 2336 The Scalable Vector Extension (SVE) is an extension to the AArch64 2337 execution state which complements and extends the SIMD functionality 2338 of the base architecture to support much larger vectors and to enable 2339 additional vectorisation opportunities. 2340 2341 To enable use of this extension on CPUs that implement it, say Y. 2342 2343 On CPUs that support the SVE2 extensions, this option will enable 2344 those too. 2345 2346 Note that for architectural reasons, firmware _must_ implement SVE 2347 support when running on SVE capable hardware. The required support 2348 is present in: 2349 2350 * version 1.5 and later of the ARM Trusted Firmware 2351 * the AArch64 boot wrapper since commit 5e1261e08abf 2352 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2353 2354 For other firmware implementations, consult the firmware documentation 2355 or vendor. 2356 2357 If you need the kernel to boot on SVE-capable hardware with broken 2358 firmware, you may need to say N here until you get your firmware 2359 fixed. Otherwise, you may experience firmware panics or lockups when 2360 booting the kernel. If unsure and you are not observing these 2361 symptoms, you should assume that it is safe to say Y. 2362 2363config AS_HAS_SME 2364 # Supported by LLVM 13+ and binutils 2.38+ 2365 def_bool $(as-instr,.arch_extension sme) 2366 2367config ARM64_SME 2368 bool "ARM Scalable Matrix Extension support" 2369 default y 2370 depends on ARM64_SVE 2371 depends on AS_HAS_SME 2372 help 2373 The Scalable Matrix Extension (SME) is an extension to the AArch64 2374 execution state which utilises a substantial subset of the SVE 2375 instruction set, together with the addition of new architectural 2376 register state capable of holding two dimensional matrix tiles to 2377 enable various matrix operations. 2378 2379config ARM64_PSEUDO_NMI 2380 bool "Support for NMI-like interrupts" 2381 select ARM_GIC_V3 2382 help 2383 Adds support for mimicking Non-Maskable Interrupts through the use of 2384 GIC interrupt priority. This support requires version 3 or later of 2385 ARM GIC. 2386 2387 This high priority configuration for interrupts needs to be 2388 explicitly enabled by setting the kernel parameter 2389 "irqchip.gicv3_pseudo_nmi" to 1. 2390 2391 If unsure, say N 2392 2393if ARM64_PSEUDO_NMI 2394config ARM64_DEBUG_PRIORITY_MASKING 2395 bool "Debug interrupt priority masking" 2396 help 2397 This adds runtime checks to functions enabling/disabling 2398 interrupts when using priority masking. The additional checks verify 2399 the validity of ICC_PMR_EL1 when calling concerned functions. 2400 2401 If unsure, say N 2402endif # ARM64_PSEUDO_NMI 2403 2404config RELOCATABLE 2405 bool "Build a relocatable kernel image" if EXPERT 2406 select ARCH_HAS_RELR 2407 default y 2408 help 2409 This builds the kernel as a Position Independent Executable (PIE), 2410 which retains all relocation metadata required to relocate the 2411 kernel binary at runtime to a different virtual address than the 2412 address it was linked at. 2413 Since AArch64 uses the RELA relocation format, this requires a 2414 relocation pass at runtime even if the kernel is loaded at the 2415 same address it was linked at. 2416 2417config RANDOMIZE_BASE 2418 bool "Randomize the address of the kernel image" 2419 select RELOCATABLE 2420 help 2421 Randomizes the virtual address at which the kernel image is 2422 loaded, as a security feature that deters exploit attempts 2423 relying on knowledge of the location of kernel internals. 2424 2425 It is the bootloader's job to provide entropy, by passing a 2426 random u64 value in /chosen/kaslr-seed at kernel entry. 2427 2428 When booting via the UEFI stub, it will invoke the firmware's 2429 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2430 to the kernel proper. In addition, it will randomise the physical 2431 location of the kernel Image as well. 2432 2433 If unsure, say N. 2434 2435config RANDOMIZE_MODULE_REGION_FULL 2436 bool "Randomize the module region over a 2 GB range" 2437 depends on RANDOMIZE_BASE 2438 default y 2439 help 2440 Randomizes the location of the module region inside a 2 GB window 2441 covering the core kernel. This way, it is less likely for modules 2442 to leak information about the location of core kernel data structures 2443 but it does imply that function calls between modules and the core 2444 kernel will need to be resolved via veneers in the module PLT. 2445 2446 When this option is not set, the module region will be randomized over 2447 a limited range that contains the [_stext, _etext] interval of the 2448 core kernel, so branch relocations are almost always in range unless 2449 the region is exhausted. In this particular case of region 2450 exhaustion, modules might be able to fall back to a larger 2GB area. 2451 2452config CC_HAVE_STACKPROTECTOR_SYSREG 2453 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2454 2455config STACKPROTECTOR_PER_TASK 2456 def_bool y 2457 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2458 2459config UNWIND_PATCH_PAC_INTO_SCS 2460 bool "Enable shadow call stack dynamically using code patching" 2461 depends on CC_IS_CLANG 2462 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2463 depends on SHADOW_CALL_STACK 2464 select UNWIND_TABLES 2465 select DYNAMIC_SCS 2466 2467config ARM64_CONTPTE 2468 bool "Contiguous PTE mappings for user memory" if EXPERT 2469 depends on TRANSPARENT_HUGEPAGE 2470 default y 2471 help 2472 When enabled, user mappings are configured using the PTE contiguous 2473 bit, for any mappings that meet the size and alignment requirements. 2474 This reduces TLB pressure and improves performance. 2475 2476endmenu # "Kernel Features" 2477 2478menu "Boot options" 2479 2480config ARM64_ACPI_PARKING_PROTOCOL 2481 bool "Enable support for the ARM64 ACPI parking protocol" 2482 depends on ACPI 2483 help 2484 Enable support for the ARM64 ACPI parking protocol. If disabled 2485 the kernel will not allow booting through the ARM64 ACPI parking 2486 protocol even if the corresponding data is present in the ACPI 2487 MADT table. 2488 2489config CMDLINE 2490 string "Default kernel command string" 2491 default "" 2492 help 2493 Provide a set of default command-line options at build time by 2494 entering them here. As a minimum, you should specify the 2495 root device (e.g. root=/dev/nfs). 2496 2497choice 2498 prompt "Kernel command line type" 2499 depends on CMDLINE != "" 2500 default CMDLINE_FROM_BOOTLOADER 2501 help 2502 Choose how the kernel will handle the provided default kernel 2503 command line string. 2504 2505config CMDLINE_FROM_BOOTLOADER 2506 bool "Use bootloader kernel arguments if available" 2507 help 2508 Uses the command-line options passed by the boot loader. If 2509 the boot loader doesn't provide any, the default kernel command 2510 string provided in CMDLINE will be used. 2511 2512config CMDLINE_FORCE 2513 bool "Always use the default kernel command string" 2514 help 2515 Always use the default kernel command string, even if the boot 2516 loader passes other arguments to the kernel. 2517 This is useful if you cannot or don't want to change the 2518 command-line options your boot loader passes to the kernel. 2519 2520endchoice 2521 2522config EFI_STUB 2523 bool 2524 2525config EFI 2526 bool "UEFI runtime support" 2527 depends on OF && !CPU_BIG_ENDIAN 2528 depends on KERNEL_MODE_NEON 2529 select ARCH_SUPPORTS_ACPI 2530 select LIBFDT 2531 select UCS2_STRING 2532 select EFI_PARAMS_FROM_FDT 2533 select EFI_RUNTIME_WRAPPERS 2534 select EFI_STUB 2535 select EFI_GENERIC_STUB 2536 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2537 default y 2538 help 2539 This option provides support for runtime services provided 2540 by UEFI firmware (such as non-volatile variables, realtime 2541 clock, and platform reset). A UEFI stub is also provided to 2542 allow the kernel to be booted as an EFI application. This 2543 is only useful on systems that have UEFI firmware. 2544 2545config COMPRESSED_INSTALL 2546 bool "Install compressed image by default" 2547 help 2548 This makes the regular "make install" install the compressed 2549 image we built, not the legacy uncompressed one. 2550 2551 You can check that a compressed image works for you by doing 2552 "make zinstall" first, and verifying that everything is fine 2553 in your environment before making "make install" do this for 2554 you. 2555 2556config DMI 2557 bool "Enable support for SMBIOS (DMI) tables" 2558 depends on EFI 2559 default y 2560 help 2561 This enables SMBIOS/DMI feature for systems. 2562 2563 This option is only useful on systems that have UEFI firmware. 2564 However, even with this option, the resultant kernel should 2565 continue to boot on existing non-UEFI platforms. 2566 2567endmenu # "Boot options" 2568 2569menu "Power management options" 2570 2571source "kernel/power/Kconfig" 2572 2573config ARCH_HIBERNATION_POSSIBLE 2574 def_bool y 2575 depends on CPU_PM 2576 2577config ARCH_HIBERNATION_HEADER 2578 def_bool y 2579 depends on HIBERNATION 2580 2581config ARCH_SUSPEND_POSSIBLE 2582 def_bool y 2583 2584endmenu # "Power management options" 2585 2586menu "CPU Power Management" 2587 2588source "drivers/cpuidle/Kconfig" 2589 2590source "drivers/cpufreq/Kconfig" 2591 2592endmenu # "CPU Power Management" 2593 2594source "drivers/acpi/Kconfig" 2595 2596source "arch/arm64/kvm/Kconfig" 2597 2598source "kernel/livepatch/Kconfig" 2599