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_ENABLE_THP_MIGRATION 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_SUPPORTS_NUMA_BALANCING 82 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 83 select ARCH_SUPPORTS_PER_VMA_LOCK 84 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 85 select ARCH_SUPPORTS_RT 86 select ARCH_SUPPORTS_SCHED_SMT 87 select ARCH_SUPPORTS_SCHED_CLUSTER 88 select ARCH_SUPPORTS_SCHED_MC 89 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 90 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 91 select ARCH_WANT_DEFAULT_BPF_JIT 92 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 93 select ARCH_WANT_FRAME_POINTERS 94 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 95 select ARCH_WANT_LD_ORPHAN_WARN 96 select ARCH_WANTS_EXECMEM_LATE 97 select ARCH_WANTS_NO_INSTR 98 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 99 select ARCH_HAS_UBSAN 100 select ARM_AMBA 101 select ARM_ARCH_TIMER 102 select ARM_GIC 103 select AUDIT_ARCH_COMPAT_GENERIC 104 select ARM_GIC_V2M if PCI 105 select ARM_GIC_V3 106 select ARM_GIC_V3_ITS if PCI 107 select ARM_GIC_V5 108 select ARM_PSCI_FW 109 select BUILDTIME_TABLE_SORT 110 select CLONE_BACKWARDS 111 select COMMON_CLK 112 select CPU_PM if (SUSPEND || CPU_IDLE) 113 select CPUMASK_OFFSTACK if NR_CPUS > 256 114 select DCACHE_WORD_ACCESS 115 select HAVE_EXTRA_IPI_TRACEPOINTS 116 select DYNAMIC_FTRACE if FUNCTION_TRACER 117 select DMA_BOUNCE_UNALIGNED_KMALLOC 118 select DMA_DIRECT_REMAP 119 select EDAC_SUPPORT 120 select FRAME_POINTER 121 select FUNCTION_ALIGNMENT_4B 122 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 123 select GENERIC_ALLOCATOR 124 select GENERIC_ARCH_TOPOLOGY 125 select GENERIC_CLOCKEVENTS_BROADCAST 126 select GENERIC_CPU_AUTOPROBE 127 select GENERIC_CPU_CACHE_MAINTENANCE 128 select GENERIC_CPU_DEVICES 129 select GENERIC_CPU_VULNERABILITIES 130 select GENERIC_EARLY_IOREMAP 131 select GENERIC_IDLE_POLL_SETUP 132 select GENERIC_IOREMAP 133 select GENERIC_IRQ_ENTRY 134 select GENERIC_IRQ_IPI 135 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 136 select GENERIC_IRQ_PROBE 137 select GENERIC_IRQ_SHOW 138 select GENERIC_IRQ_SHOW_LEVEL 139 select GENERIC_LIB_DEVMEM_IS_ALLOWED 140 select GENERIC_PCI_IOMAP 141 select GENERIC_SCHED_CLOCK 142 select GENERIC_SMP_IDLE_THREAD 143 select GENERIC_GETTIMEOFDAY 144 select HARDIRQS_SW_RESEND 145 select HAS_IOPORT 146 select HAVE_MOVE_PMD 147 select HAVE_MOVE_PUD 148 select HAVE_PCI 149 select HAVE_ACPI_APEI if (ACPI && EFI) 150 select HAVE_ALIGNED_STRUCT_PAGE 151 select HAVE_ARCH_AUDITSYSCALL 152 select HAVE_ARCH_BITREVERSE 153 select HAVE_ARCH_COMPILER_H 154 select HAVE_ARCH_HUGE_VMALLOC 155 select HAVE_ARCH_HUGE_VMAP 156 select HAVE_ARCH_JUMP_LABEL 157 select HAVE_ARCH_JUMP_LABEL_RELATIVE 158 select HAVE_ARCH_KASAN 159 select HAVE_ARCH_KASAN_VMALLOC 160 select HAVE_ARCH_KASAN_SW_TAGS 161 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 162 # Some instrumentation may be unsound, hence EXPERT 163 select HAVE_ARCH_KCSAN if EXPERT 164 select HAVE_ARCH_KFENCE 165 select HAVE_ARCH_KGDB 166 select HAVE_ARCH_KSTACK_ERASE 167 select HAVE_ARCH_MMAP_RND_BITS 168 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 169 select HAVE_ARCH_PREL32_RELOCATIONS 170 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 171 select HAVE_ARCH_SECCOMP_FILTER 172 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 173 select HAVE_ARCH_TRACEHOOK 174 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 175 select HAVE_ARCH_VMAP_STACK 176 select HAVE_ARM_SMCCC 177 select HAVE_ASM_MODVERSIONS 178 select HAVE_EBPF_JIT 179 select HAVE_C_RECORDMCOUNT 180 select HAVE_CMPXCHG_DOUBLE 181 select HAVE_CMPXCHG_LOCAL 182 select HAVE_CONTEXT_TRACKING_USER 183 select HAVE_DEBUG_KMEMLEAK 184 select HAVE_DMA_CONTIGUOUS 185 select HAVE_DYNAMIC_FTRACE 186 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 187 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 188 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 189 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 190 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 191 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 192 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ 193 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 194 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 195 if DYNAMIC_FTRACE_WITH_ARGS 196 select HAVE_SAMPLE_FTRACE_DIRECT 197 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 198 select HAVE_BUILDTIME_MCOUNT_SORT 199 select HAVE_EFFICIENT_UNALIGNED_ACCESS 200 select HAVE_GUP_FAST 201 select HAVE_FTRACE_GRAPH_FUNC 202 select HAVE_FUNCTION_TRACER 203 select HAVE_FUNCTION_ERROR_INJECTION 204 select HAVE_FUNCTION_GRAPH_FREGS 205 select HAVE_FUNCTION_GRAPH_TRACER 206 select HAVE_GCC_PLUGINS 207 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 208 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 209 select HAVE_HW_BREAKPOINT if PERF_EVENTS 210 select HAVE_IOREMAP_PROT 211 select HAVE_IRQ_TIME_ACCOUNTING 212 select HAVE_LIVEPATCH 213 select HAVE_MOD_ARCH_SPECIFIC 214 select HAVE_NMI 215 select HAVE_PERF_EVENTS 216 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 217 select HAVE_PERF_REGS 218 select HAVE_PERF_USER_STACK_DUMP 219 select HAVE_PREEMPT_DYNAMIC_KEY 220 select HAVE_REGS_AND_STACK_ACCESS_API 221 select HAVE_RELIABLE_STACKTRACE 222 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 223 select HAVE_FUNCTION_ARG_ACCESS_API 224 select MMU_GATHER_RCU_TABLE_FREE 225 select HAVE_RSEQ 226 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 227 select HAVE_STACKPROTECTOR 228 select HAVE_STATIC_CALL if CFI 229 select HAVE_SYSCALL_TRACEPOINTS 230 select HAVE_KPROBES 231 select HAVE_KRETPROBES 232 select HAVE_GENERIC_VDSO 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 SPARSE_IRQ 251 select SWIOTLB 252 select SYSCTL_EXCEPTION_TRACE 253 select THREAD_INFO_IN_TASK 254 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 255 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 256 select TRACE_IRQFLAGS_SUPPORT 257 select TRACE_IRQFLAGS_NMI_SUPPORT 258 select HAVE_SOFTIRQ_ON_OWN_STACK 259 select USER_STACKTRACE_SUPPORT 260 select VDSO_GETRANDOM 261 select VMAP_STACK 262 help 263 ARM 64-bit (AArch64) Linux support. 264 265config RUSTC_SUPPORTS_ARM64 266 def_bool y 267 depends on CPU_LITTLE_ENDIAN 268 269config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 270 def_bool CC_IS_CLANG 271 # https://github.com/ClangBuiltLinux/linux/issues/1507 272 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 273 274config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 275 def_bool CC_IS_GCC 276 depends on $(cc-option,-fpatchable-function-entry=2) 277 278config 64BIT 279 def_bool y 280 281config MMU 282 def_bool y 283 284config ARM64_CONT_PTE_SHIFT 285 int 286 default 5 if PAGE_SIZE_64KB 287 default 7 if PAGE_SIZE_16KB 288 default 4 289 290config ARM64_CONT_PMD_SHIFT 291 int 292 default 5 if PAGE_SIZE_64KB 293 default 5 if PAGE_SIZE_16KB 294 default 4 295 296config ARCH_MMAP_RND_BITS_MIN 297 default 14 if PAGE_SIZE_64KB 298 default 16 if PAGE_SIZE_16KB 299 default 18 300 301# max bits determined by the following formula: 302# VA_BITS - PTDESC_TABLE_SHIFT 303config ARCH_MMAP_RND_BITS_MAX 304 default 19 if ARM64_VA_BITS=36 305 default 24 if ARM64_VA_BITS=39 306 default 27 if ARM64_VA_BITS=42 307 default 30 if ARM64_VA_BITS=47 308 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 309 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 310 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 311 default 14 if ARM64_64K_PAGES 312 default 16 if ARM64_16K_PAGES 313 default 18 314 315config ARCH_MMAP_RND_COMPAT_BITS_MIN 316 default 7 if ARM64_64K_PAGES 317 default 9 if ARM64_16K_PAGES 318 default 11 319 320config ARCH_MMAP_RND_COMPAT_BITS_MAX 321 default 16 322 323config NO_IOPORT_MAP 324 def_bool y if !PCI 325 326config STACKTRACE_SUPPORT 327 def_bool y 328 329config ILLEGAL_POINTER_VALUE 330 hex 331 default 0xdead000000000000 332 333config LOCKDEP_SUPPORT 334 def_bool y 335 336config GENERIC_BUG 337 def_bool y 338 depends on BUG 339 340config GENERIC_BUG_RELATIVE_POINTERS 341 def_bool y 342 depends on GENERIC_BUG 343 344config GENERIC_HWEIGHT 345 def_bool y 346 347config GENERIC_CSUM 348 def_bool y 349 350config GENERIC_CALIBRATE_DELAY 351 def_bool y 352 353config SMP 354 def_bool y 355 356config KERNEL_MODE_NEON 357 def_bool y 358 359config FIX_EARLYCON_MEM 360 def_bool y 361 362config PGTABLE_LEVELS 363 int 364 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 365 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 366 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 367 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 368 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 369 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 370 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 371 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 372 373config ARCH_SUPPORTS_UPROBES 374 def_bool y 375 376config ARCH_PROC_KCORE_TEXT 377 def_bool y 378 379config BROKEN_GAS_INST 380 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 381 382config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 383 bool 384 # Clang's __builtin_return_address() strips the PAC since 12.0.0 385 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 386 default y if CC_IS_CLANG 387 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 388 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 389 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 390 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 391 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 392 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 393 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 394 default n 395 396config KASAN_SHADOW_OFFSET 397 hex 398 depends on KASAN_GENERIC || KASAN_SW_TAGS 399 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 400 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 401 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 402 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 403 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 404 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 405 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 406 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 407 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 408 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 409 default 0xffffffffffffffff 410 411config UNWIND_TABLES 412 bool 413 414source "arch/arm64/Kconfig.platforms" 415 416menu "Kernel Features" 417 418menu "ARM errata workarounds via the alternatives framework" 419 420config AMPERE_ERRATUM_AC03_CPU_38 421 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 422 default y 423 help 424 This option adds an alternative code sequence to work around Ampere 425 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 426 427 The affected design reports FEAT_HAFDBS as not implemented in 428 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 429 as required by the architecture. The unadvertised HAFDBS 430 implementation suffers from an additional erratum where hardware 431 A/D updates can occur after a PTE has been marked invalid. 432 433 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 434 which avoids enabling unadvertised hardware Access Flag management 435 at stage-2. 436 437 If unsure, say Y. 438 439config AMPERE_ERRATUM_AC04_CPU_23 440 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 441 default y 442 help 443 This option adds an alternative code sequence to work around Ampere 444 errata AC04_CPU_23 on AmpereOne. 445 446 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 447 data addresses initiated by load/store instructions. Only 448 instruction initiated translations are vulnerable, not translations 449 from prefetches for example. A DSB before the store to HCR_EL2 is 450 sufficient to prevent older instructions from hitting the window 451 for corruption, and an ISB after is sufficient to prevent younger 452 instructions from hitting the window for corruption. 453 454 If unsure, say Y. 455 456config ARM64_WORKAROUND_CLEAN_CACHE 457 bool 458 459config ARM64_ERRATUM_826319 460 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 461 default y 462 select ARM64_WORKAROUND_CLEAN_CACHE 463 help 464 This option adds an alternative code sequence to work around ARM 465 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 466 AXI master interface and an L2 cache. 467 468 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 469 and is unable to accept a certain write via this interface, it will 470 not progress on read data presented on the read data channel and the 471 system can deadlock. 472 473 The workaround promotes data cache clean instructions to 474 data cache clean-and-invalidate. 475 Please note that this does not necessarily enable the workaround, 476 as it depends on the alternative framework, which will only patch 477 the kernel if an affected CPU is detected. 478 479 If unsure, say Y. 480 481config ARM64_ERRATUM_827319 482 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 483 default y 484 select ARM64_WORKAROUND_CLEAN_CACHE 485 help 486 This option adds an alternative code sequence to work around ARM 487 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 488 master interface and an L2 cache. 489 490 Under certain conditions this erratum can cause a clean line eviction 491 to occur at the same time as another transaction to the same address 492 on the AMBA 5 CHI interface, which can cause data corruption if the 493 interconnect reorders the two transactions. 494 495 The workaround promotes data cache clean instructions to 496 data cache clean-and-invalidate. 497 Please note that this does not necessarily enable the workaround, 498 as it depends on the alternative framework, which will only patch 499 the kernel if an affected CPU is detected. 500 501 If unsure, say Y. 502 503config ARM64_ERRATUM_824069 504 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 505 default y 506 select ARM64_WORKAROUND_CLEAN_CACHE 507 help 508 This option adds an alternative code sequence to work around ARM 509 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 510 to a coherent interconnect. 511 512 If a Cortex-A53 processor is executing a store or prefetch for 513 write instruction at the same time as a processor in another 514 cluster is executing a cache maintenance operation to the same 515 address, then this erratum might cause a clean cache line to be 516 incorrectly marked as dirty. 517 518 The workaround promotes data cache clean instructions to 519 data cache clean-and-invalidate. 520 Please note that this option does not necessarily enable the 521 workaround, as it depends on the alternative framework, which will 522 only patch the kernel if an affected CPU is detected. 523 524 If unsure, say Y. 525 526config ARM64_ERRATUM_819472 527 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 528 default y 529 select ARM64_WORKAROUND_CLEAN_CACHE 530 help 531 This option adds an alternative code sequence to work around ARM 532 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 533 present when it is connected to a coherent interconnect. 534 535 If the processor is executing a load and store exclusive sequence at 536 the same time as a processor in another cluster is executing a cache 537 maintenance operation to the same address, then this erratum might 538 cause data corruption. 539 540 The workaround promotes data cache clean instructions to 541 data cache clean-and-invalidate. 542 Please note that this does not necessarily enable the workaround, 543 as it depends on the alternative framework, which will only patch 544 the kernel if an affected CPU is detected. 545 546 If unsure, say Y. 547 548config ARM64_ERRATUM_832075 549 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 550 default y 551 help 552 This option adds an alternative code sequence to work around ARM 553 erratum 832075 on Cortex-A57 parts up to r1p2. 554 555 Affected Cortex-A57 parts might deadlock when exclusive load/store 556 instructions to Write-Back memory are mixed with Device loads. 557 558 The workaround is to promote device loads to use Load-Acquire 559 semantics. 560 Please note that this does not necessarily enable the workaround, 561 as it depends on the alternative framework, which will only patch 562 the kernel if an affected CPU is detected. 563 564 If unsure, say Y. 565 566config ARM64_ERRATUM_834220 567 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 568 depends on KVM 569 help 570 This option adds an alternative code sequence to work around ARM 571 erratum 834220 on Cortex-A57 parts up to r1p2. 572 573 Affected Cortex-A57 parts might report a Stage 2 translation 574 fault as the result of a Stage 1 fault for load crossing a 575 page boundary when there is a permission or device memory 576 alignment fault at Stage 1 and a translation fault at Stage 2. 577 578 The workaround is to verify that the Stage 1 translation 579 doesn't generate a fault before handling the Stage 2 fault. 580 Please note that this does not necessarily enable the workaround, 581 as it depends on the alternative framework, which will only patch 582 the kernel if an affected CPU is detected. 583 584 If unsure, say N. 585 586config ARM64_ERRATUM_1742098 587 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 588 depends on COMPAT 589 default y 590 help 591 This option removes the AES hwcap for aarch32 user-space to 592 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 593 594 Affected parts may corrupt the AES state if an interrupt is 595 taken between a pair of AES instructions. These instructions 596 are only present if the cryptography extensions are present. 597 All software should have a fallback implementation for CPUs 598 that don't implement the cryptography extensions. 599 600 If unsure, say Y. 601 602config ARM64_ERRATUM_845719 603 bool "Cortex-A53: 845719: a load might read incorrect data" 604 depends on COMPAT 605 default y 606 help 607 This option adds an alternative code sequence to work around ARM 608 erratum 845719 on Cortex-A53 parts up to r0p4. 609 610 When running a compat (AArch32) userspace on an affected Cortex-A53 611 part, a load at EL0 from a virtual address that matches the bottom 32 612 bits of the virtual address used by a recent load at (AArch64) EL1 613 might return incorrect data. 614 615 The workaround is to write the contextidr_el1 register on exception 616 return to a 32-bit task. 617 Please note that this does not necessarily enable the workaround, 618 as it depends on the alternative framework, which will only patch 619 the kernel if an affected CPU is detected. 620 621 If unsure, say Y. 622 623config ARM64_ERRATUM_843419 624 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 625 default y 626 help 627 This option links the kernel with '--fix-cortex-a53-843419' and 628 enables PLT support to replace certain ADRP instructions, which can 629 cause subsequent memory accesses to use an incorrect address on 630 Cortex-A53 parts up to r0p4. 631 632 If unsure, say Y. 633 634config ARM64_ERRATUM_1024718 635 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 636 default y 637 help 638 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 639 640 Affected Cortex-A55 cores (all revisions) could cause incorrect 641 update of the hardware dirty bit when the DBM/AP bits are updated 642 without a break-before-make. The workaround is to disable the usage 643 of hardware DBM locally on the affected cores. CPUs not affected by 644 this erratum will continue to use the feature. 645 646 If unsure, say Y. 647 648config ARM64_ERRATUM_1418040 649 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 650 default y 651 depends on COMPAT 652 help 653 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 654 errata 1188873 and 1418040. 655 656 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 657 cause register corruption when accessing the timer registers 658 from AArch32 userspace. 659 660 If unsure, say Y. 661 662config ARM64_WORKAROUND_SPECULATIVE_AT 663 bool 664 665config ARM64_ERRATUM_1165522 666 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 667 default y 668 select ARM64_WORKAROUND_SPECULATIVE_AT 669 help 670 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 671 672 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 673 corrupted TLBs by speculating an AT instruction during a guest 674 context switch. 675 676 If unsure, say Y. 677 678config ARM64_ERRATUM_1319367 679 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 680 default y 681 select ARM64_WORKAROUND_SPECULATIVE_AT 682 help 683 This option adds work arounds for ARM Cortex-A57 erratum 1319537 684 and A72 erratum 1319367 685 686 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 687 speculating an AT instruction during a guest context switch. 688 689 If unsure, say Y. 690 691config ARM64_ERRATUM_1530923 692 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 693 default y 694 select ARM64_WORKAROUND_SPECULATIVE_AT 695 help 696 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 697 698 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 699 corrupted TLBs by speculating an AT instruction during a guest 700 context switch. 701 702 If unsure, say Y. 703 704config ARM64_WORKAROUND_REPEAT_TLBI 705 bool 706 707config ARM64_ERRATUM_2441007 708 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 709 select ARM64_WORKAROUND_REPEAT_TLBI 710 help 711 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 712 713 Under very rare circumstances, affected Cortex-A55 CPUs 714 may not handle a race between a break-before-make sequence on one 715 CPU, and another CPU accessing the same page. This could allow a 716 store to a page that has been unmapped. 717 718 Work around this by adding the affected CPUs to the list that needs 719 TLB sequences to be done twice. 720 721 If unsure, say N. 722 723config ARM64_ERRATUM_1286807 724 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 725 select ARM64_WORKAROUND_REPEAT_TLBI 726 help 727 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 728 729 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 730 address for a cacheable mapping of a location is being 731 accessed by a core while another core is remapping the virtual 732 address to a new physical page using the recommended 733 break-before-make sequence, then under very rare circumstances 734 TLBI+DSB completes before a read using the translation being 735 invalidated has been observed by other observers. The 736 workaround repeats the TLBI+DSB operation. 737 738 If unsure, say N. 739 740config ARM64_ERRATUM_1463225 741 bool "Cortex-A76: Software Step might prevent interrupt recognition" 742 default y 743 help 744 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 745 746 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 747 of a system call instruction (SVC) can prevent recognition of 748 subsequent interrupts when software stepping is disabled in the 749 exception handler of the system call and either kernel debugging 750 is enabled or VHE is in use. 751 752 Work around the erratum by triggering a dummy step exception 753 when handling a system call from a task that is being stepped 754 in a VHE configuration of the kernel. 755 756 If unsure, say Y. 757 758config ARM64_ERRATUM_1542419 759 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 760 help 761 This option adds a workaround for ARM Neoverse-N1 erratum 762 1542419. 763 764 Affected Neoverse-N1 cores could execute a stale instruction when 765 modified by another CPU. The workaround depends on a firmware 766 counterpart. 767 768 Workaround the issue by hiding the DIC feature from EL0. This 769 forces user-space to perform cache maintenance. 770 771 If unsure, say N. 772 773config ARM64_ERRATUM_1508412 774 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 775 default y 776 help 777 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 778 779 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 780 of a store-exclusive or read of PAR_EL1 and a load with device or 781 non-cacheable memory attributes. The workaround depends on a firmware 782 counterpart. 783 784 KVM guests must also have the workaround implemented or they can 785 deadlock the system. 786 787 Work around the issue by inserting DMB SY barriers around PAR_EL1 788 register reads and warning KVM users. The DMB barrier is sufficient 789 to prevent a speculative PAR_EL1 read. 790 791 If unsure, say Y. 792 793config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 794 bool 795 796config ARM64_ERRATUM_2051678 797 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 798 default y 799 help 800 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 801 Affected Cortex-A510 might not respect the ordering rules for 802 hardware update of the page table's dirty bit. The workaround 803 is to not enable the feature on affected CPUs. 804 805 If unsure, say Y. 806 807config ARM64_ERRATUM_2077057 808 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 809 default y 810 help 811 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 812 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 813 expected, but a Pointer Authentication trap is taken instead. The 814 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 815 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 816 817 This can only happen when EL2 is stepping EL1. 818 819 When these conditions occur, the SPSR_EL2 value is unchanged from the 820 previous guest entry, and can be restored from the in-memory copy. 821 822 If unsure, say Y. 823 824config ARM64_ERRATUM_2658417 825 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 826 default y 827 help 828 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 829 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 830 BFMMLA or VMMLA instructions in rare circumstances when a pair of 831 A510 CPUs are using shared neon hardware. As the sharing is not 832 discoverable by the kernel, hide the BF16 HWCAP to indicate that 833 user-space should not be using these instructions. 834 835 If unsure, say Y. 836 837config ARM64_ERRATUM_2119858 838 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 839 default y 840 depends on CORESIGHT_TRBE 841 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 842 help 843 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 844 845 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 846 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 847 the event of a WRAP event. 848 849 Work around the issue by always making sure we move the TRBPTR_EL1 by 850 256 bytes before enabling the buffer and filling the first 256 bytes of 851 the buffer with ETM ignore packets upon disabling. 852 853 If unsure, say Y. 854 855config ARM64_ERRATUM_2139208 856 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 857 default y 858 depends on CORESIGHT_TRBE 859 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 860 help 861 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 862 863 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 864 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 865 the event of a WRAP event. 866 867 Work around the issue by always making sure we move the TRBPTR_EL1 by 868 256 bytes before enabling the buffer and filling the first 256 bytes of 869 the buffer with ETM ignore packets upon disabling. 870 871 If unsure, say Y. 872 873config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 874 bool 875 876config ARM64_ERRATUM_2054223 877 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 878 default y 879 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 880 help 881 Enable workaround for ARM Cortex-A710 erratum 2054223 882 883 Affected cores may fail to flush the trace data on a TSB instruction, when 884 the PE is in trace prohibited state. This will cause losing a few bytes 885 of the trace cached. 886 887 Workaround is to issue two TSB consecutively on affected cores. 888 889 If unsure, say Y. 890 891config ARM64_ERRATUM_2067961 892 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 893 default y 894 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 895 help 896 Enable workaround for ARM Neoverse-N2 erratum 2067961 897 898 Affected cores may fail to flush the trace data on a TSB instruction, when 899 the PE is in trace prohibited state. This will cause losing a few bytes 900 of the trace cached. 901 902 Workaround is to issue two TSB consecutively on affected cores. 903 904 If unsure, say Y. 905 906config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 907 bool 908 909config ARM64_ERRATUM_2253138 910 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 911 depends on CORESIGHT_TRBE 912 default y 913 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 914 help 915 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 916 917 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 918 for TRBE. Under some conditions, the TRBE might generate a write to the next 919 virtually addressed page following the last page of the TRBE address space 920 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 921 922 Work around this in the driver by always making sure that there is a 923 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 924 925 If unsure, say Y. 926 927config ARM64_ERRATUM_2224489 928 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 929 depends on CORESIGHT_TRBE 930 default y 931 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 932 help 933 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 934 935 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 936 for TRBE. Under some conditions, the TRBE might generate a write to the next 937 virtually addressed page following the last page of the TRBE address space 938 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 939 940 Work around this in the driver by always making sure that there is a 941 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 942 943 If unsure, say Y. 944 945config ARM64_ERRATUM_2441009 946 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 947 select ARM64_WORKAROUND_REPEAT_TLBI 948 help 949 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 950 951 Under very rare circumstances, affected Cortex-A510 CPUs 952 may not handle a race between a break-before-make sequence on one 953 CPU, and another CPU accessing the same page. This could allow a 954 store to a page that has been unmapped. 955 956 Work around this by adding the affected CPUs to the list that needs 957 TLB sequences to be done twice. 958 959 If unsure, say N. 960 961config ARM64_ERRATUM_2064142 962 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 963 depends on CORESIGHT_TRBE 964 default y 965 help 966 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 967 968 Affected Cortex-A510 core might fail to write into system registers after the 969 TRBE has been disabled. Under some conditions after the TRBE has been disabled 970 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 971 and TRBTRG_EL1 will be ignored and will not be effected. 972 973 Work around this in the driver by executing TSB CSYNC and DSB after collection 974 is stopped and before performing a system register write to one of the affected 975 registers. 976 977 If unsure, say Y. 978 979config ARM64_ERRATUM_2038923 980 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 981 depends on CORESIGHT_TRBE 982 default y 983 help 984 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 985 986 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 987 prohibited within the CPU. As a result, the trace buffer or trace buffer state 988 might be corrupted. This happens after TRBE buffer has been enabled by setting 989 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 990 execution changes from a context, in which trace is prohibited to one where it 991 isn't, or vice versa. In these mentioned conditions, the view of whether trace 992 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 993 the trace buffer state might be corrupted. 994 995 Work around this in the driver by preventing an inconsistent view of whether the 996 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 997 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 998 two ISB instructions if no ERET is to take place. 999 1000 If unsure, say Y. 1001 1002config ARM64_ERRATUM_1902691 1003 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1004 depends on CORESIGHT_TRBE 1005 default y 1006 help 1007 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1008 1009 Affected Cortex-A510 core might cause trace data corruption, when being written 1010 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1011 trace data. 1012 1013 Work around this problem in the driver by just preventing TRBE initialization on 1014 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1015 on such implementations. This will cover the kernel for any firmware that doesn't 1016 do this already. 1017 1018 If unsure, say Y. 1019 1020config ARM64_ERRATUM_2457168 1021 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1022 depends on ARM64_AMU_EXTN 1023 default y 1024 help 1025 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1026 1027 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1028 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1029 incorrectly giving a significantly higher output value. 1030 1031 Work around this problem by returning 0 when reading the affected counter in 1032 key locations that results in disabling all users of this counter. This effect 1033 is the same to firmware disabling affected counters. 1034 1035 If unsure, say Y. 1036 1037config ARM64_ERRATUM_2645198 1038 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1039 default y 1040 help 1041 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1042 1043 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1044 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1045 next instruction abort caused by permission fault. 1046 1047 Only user-space does executable to non-executable permission transition via 1048 mprotect() system call. Workaround the problem by doing a break-before-make 1049 TLB invalidation, for all changes to executable user space mappings. 1050 1051 If unsure, say Y. 1052 1053config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1054 bool 1055 1056config ARM64_ERRATUM_2966298 1057 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1058 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1059 default y 1060 help 1061 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1062 1063 On an affected Cortex-A520 core, a speculatively executed unprivileged 1064 load might leak data from a privileged level via a cache side channel. 1065 1066 Work around this problem by executing a TLBI before returning to EL0. 1067 1068 If unsure, say Y. 1069 1070config ARM64_ERRATUM_3117295 1071 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1072 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1073 default y 1074 help 1075 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1076 1077 On an affected Cortex-A510 core, a speculatively executed unprivileged 1078 load might leak data from a privileged level via a cache side channel. 1079 1080 Work around this problem by executing a TLBI before returning to EL0. 1081 1082 If unsure, say Y. 1083 1084config ARM64_ERRATUM_3194386 1085 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1086 default y 1087 help 1088 This option adds the workaround for the following errata: 1089 1090 * ARM Cortex-A76 erratum 3324349 1091 * ARM Cortex-A77 erratum 3324348 1092 * ARM Cortex-A78 erratum 3324344 1093 * ARM Cortex-A78C erratum 3324346 1094 * ARM Cortex-A78C erratum 3324347 1095 * ARM Cortex-A710 erratam 3324338 1096 * ARM Cortex-A715 errartum 3456084 1097 * ARM Cortex-A720 erratum 3456091 1098 * ARM Cortex-A725 erratum 3456106 1099 * ARM Cortex-X1 erratum 3324344 1100 * ARM Cortex-X1C erratum 3324346 1101 * ARM Cortex-X2 erratum 3324338 1102 * ARM Cortex-X3 erratum 3324335 1103 * ARM Cortex-X4 erratum 3194386 1104 * ARM Cortex-X925 erratum 3324334 1105 * ARM Neoverse-N1 erratum 3324349 1106 * ARM Neoverse N2 erratum 3324339 1107 * ARM Neoverse-N3 erratum 3456111 1108 * ARM Neoverse-V1 erratum 3324341 1109 * ARM Neoverse V2 erratum 3324336 1110 * ARM Neoverse-V3 erratum 3312417 1111 * ARM Neoverse-V3AE erratum 3312417 1112 1113 On affected cores "MSR SSBS, #0" instructions may not affect 1114 subsequent speculative instructions, which may permit unexepected 1115 speculative store bypassing. 1116 1117 Work around this problem by placing a Speculation Barrier (SB) or 1118 Instruction Synchronization Barrier (ISB) after kernel changes to 1119 SSBS. The presence of the SSBS special-purpose register is hidden 1120 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1121 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1122 1123 If unsure, say Y. 1124 1125config ARM64_ERRATUM_4311569 1126 bool "SI L1: 4311569: workaround for premature CMO completion erratum" 1127 default y 1128 help 1129 This option adds the workaround for ARM SI L1 erratum 4311569. 1130 1131 The erratum of SI L1 can cause an early response to a combined write 1132 and cache maintenance operation (WR+CMO) before the operation is fully 1133 completed to the Point of Serialization (POS). 1134 This can result in a non-I/O coherent agent observing stale data, 1135 potentially leading to system instability or incorrect behavior. 1136 1137 Enabling this option implements a software workaround by inserting a 1138 second loop of Cache Maintenance Operation (CMO) immediately following the 1139 end of function to do CMOs. This ensures that the data is correctly serialized 1140 before the buffer is handed off to a non-coherent agent. 1141 1142 If unsure, say Y. 1143 1144config ARM64_ERRATUM_4193714 1145 bool "C1-Pro: 4193714: SME DVMSync early acknowledgement" 1146 depends on ARM64_SME 1147 default y 1148 help 1149 Enable workaround for C1-Pro acknowledging the DVMSync before 1150 the SME memory accesses are complete. This will cause TLB 1151 maintenance for processes using SME to also issue an IPI to 1152 the affected CPUs. 1153 1154 If unsure, say Y. 1155 1156config ARM64_ERRATUM_4118414 1157 bool "Various: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 1158 default y 1159 select ARM64_WORKAROUND_REPEAT_TLBI 1160 help 1161 This option adds a workaround for the following errata: 1162 1163 * ARM C1-Premium erratum 4193780 1164 * ARM C1-Ultra erratum 4193780 1165 * ARM Cortex-A76 erratum 4193800 1166 * ARM Cortex-A76AE erratum 4193801 1167 * ARM Cortex-A77 erratum 4193798 1168 * ARM Cortex-A78 erratum 4193791 1169 * ARM Cortex-A78AE erratum 4193793 1170 * ARM Cortex-A78C erratum 4193794 1171 * ARM Cortex-A710 erratum 4193788 1172 * ARM Cortex-X1 erratum 4193791 1173 * ARM Cortex-X1C erratum 4193792 1174 * ARM Cortex-X2 erratum 4193788 1175 * ARM Cortex-X3 erratum 4193786 1176 * ARM Cortex-X4 erratum 4118414 1177 * ARM Cortex-X925 erratum 4193781 1178 * ARM Neoverse-N1 erratum 4193800 1179 * ARM Neoverse-N2 erratum 4193789 1180 * ARM Neoverse-V1 erratum 4193790 1181 * ARM Neoverse-V2 erratum 4193787 1182 * ARM Neoverse-V3 erratum 4193784 1183 * ARM Neoverse-V3AE erratum 4193784 1184 * Microsoft Azure Cobalt 100 4193789 1185 * NVIDIA Olympus erratum T410-OLY-1029 1186 1187 On affected cores, some memory accesses might not be completed by 1188 broadcast TLB invalidation. 1189 1190 This issue is also known as CVE-2025-10263. 1191 1192 If unsure, say Y. 1193 1194config CAVIUM_ERRATUM_22375 1195 bool "Cavium erratum 22375, 24313" 1196 default y 1197 help 1198 Enable workaround for errata 22375 and 24313. 1199 1200 This implements two gicv3-its errata workarounds for ThunderX. Both 1201 with a small impact affecting only ITS table allocation. 1202 1203 erratum 22375: only alloc 8MB table size 1204 erratum 24313: ignore memory access type 1205 1206 The fixes are in ITS initialization and basically ignore memory access 1207 type and table size provided by the TYPER and BASER registers. 1208 1209 If unsure, say Y. 1210 1211config CAVIUM_ERRATUM_23144 1212 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1213 depends on NUMA 1214 default y 1215 help 1216 ITS SYNC command hang for cross node io and collections/cpu mapping. 1217 1218 If unsure, say Y. 1219 1220config CAVIUM_ERRATUM_23154 1221 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1222 default y 1223 help 1224 The ThunderX GICv3 implementation requires a modified version for 1225 reading the IAR status to ensure data synchronization 1226 (access to icc_iar1_el1 is not sync'ed before and after). 1227 1228 It also suffers from erratum 38545 (also present on Marvell's 1229 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1230 spuriously presented to the CPU interface. 1231 1232 If unsure, say Y. 1233 1234config CAVIUM_ERRATUM_27456 1235 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1236 default y 1237 help 1238 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1239 instructions may cause the icache to become corrupted if it 1240 contains data for a non-current ASID. The fix is to 1241 invalidate the icache when changing the mm context. 1242 1243 If unsure, say Y. 1244 1245config CAVIUM_ERRATUM_30115 1246 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1247 default y 1248 help 1249 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1250 1.2, and T83 Pass 1.0, KVM guest execution may disable 1251 interrupts in host. Trapping both GICv3 group-0 and group-1 1252 accesses sidesteps the issue. 1253 1254 If unsure, say Y. 1255 1256config CAVIUM_TX2_ERRATUM_219 1257 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1258 default y 1259 help 1260 On Cavium ThunderX2, a load, store or prefetch instruction between a 1261 TTBR update and the corresponding context synchronizing operation can 1262 cause a spurious Data Abort to be delivered to any hardware thread in 1263 the CPU core. 1264 1265 Work around the issue by avoiding the problematic code sequence and 1266 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1267 trap handler performs the corresponding register access, skips the 1268 instruction and ensures context synchronization by virtue of the 1269 exception return. 1270 1271 If unsure, say Y. 1272 1273config FUJITSU_ERRATUM_010001 1274 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1275 default y 1276 help 1277 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1278 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1279 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1280 This fault occurs under a specific hardware condition when a 1281 load/store instruction performs an address translation using: 1282 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1283 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1284 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1285 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1286 1287 The workaround is to ensure these bits are clear in TCR_ELx. 1288 The workaround only affects the Fujitsu-A64FX. 1289 1290 If unsure, say Y. 1291 1292config HISILICON_ERRATUM_161600802 1293 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1294 default y 1295 help 1296 The HiSilicon Hip07 SoC uses the wrong redistributor base 1297 when issued ITS commands such as VMOVP and VMAPP, and requires 1298 a 128kB offset to be applied to the target address in this commands. 1299 1300 If unsure, say Y. 1301 1302config HISILICON_ERRATUM_162100801 1303 bool "Hip09 162100801 erratum support" 1304 default y 1305 help 1306 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1307 during unmapping operation, which will cause some vSGIs lost. 1308 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1309 after VMOVP. 1310 1311 If unsure, say Y. 1312 1313config HISILICON_ERRATUM_162100125 1314 bool "Hisilicon erratum 162100125" 1315 default y 1316 select ARM64_WORKAROUND_DISABLE_CNP 1317 help 1318 On HiSilicon HIP09, TLB entry matching behavior when CNP 1319 (TTBRx.CNP=1) is enabled differs from the ARM architecture 1320 specification. 1321 1322 TLB entries may be incorrectly shared between CPUs, potentially 1323 causing TLB conflicts and stale mappings. 1324 1325 Disable CNP support for affected HiSilicon HIP09 cores. 1326 1327 If unsure, say Y. 1328 1329config QCOM_FALKOR_ERRATUM_1003 1330 bool "Falkor E1003: Incorrect translation due to ASID change" 1331 default y 1332 help 1333 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1334 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1335 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1336 then only for entries in the walk cache, since the leaf translation 1337 is unchanged. Work around the erratum by invalidating the walk cache 1338 entries for the trampoline before entering the kernel proper. 1339 1340config QCOM_FALKOR_ERRATUM_1009 1341 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1342 default y 1343 select ARM64_WORKAROUND_REPEAT_TLBI 1344 help 1345 On Falkor v1, the CPU may prematurely complete a DSB following a 1346 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1347 one more time to fix the issue. 1348 1349 If unsure, say Y. 1350 1351config QCOM_QDF2400_ERRATUM_0065 1352 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1353 default y 1354 help 1355 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1356 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1357 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1358 1359 If unsure, say Y. 1360 1361config QCOM_FALKOR_ERRATUM_E1041 1362 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1363 default y 1364 help 1365 Falkor CPU may speculatively fetch instructions from an improper 1366 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1367 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1368 1369 If unsure, say Y. 1370 1371config ARM64_WORKAROUND_DISABLE_CNP 1372 bool 1373 1374config NVIDIA_CARMEL_CNP_ERRATUM 1375 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1376 default y 1377 select ARM64_WORKAROUND_DISABLE_CNP 1378 help 1379 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1380 invalidate shared TLB entries installed by a different core, as it would 1381 on standard ARM cores. 1382 1383 If unsure, say Y. 1384 1385config ROCKCHIP_ERRATUM_3568002 1386 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1387 default y 1388 help 1389 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1390 addressing limited to the first 32bit of physical address space. 1391 1392 If unsure, say Y. 1393 1394config ROCKCHIP_ERRATUM_3588001 1395 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1396 default y 1397 help 1398 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1399 This means, that its sharability feature may not be used, even though it 1400 is supported by the IP itself. 1401 1402 If unsure, say Y. 1403 1404config SOCIONEXT_SYNQUACER_PREITS 1405 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1406 default y 1407 help 1408 Socionext Synquacer SoCs implement a separate h/w block to generate 1409 MSI doorbell writes with non-zero values for the device ID. 1410 1411 If unsure, say Y. 1412 1413endmenu # "ARM errata workarounds via the alternatives framework" 1414 1415choice 1416 prompt "Page size" 1417 default ARM64_4K_PAGES 1418 help 1419 Page size (translation granule) configuration. 1420 1421config ARM64_4K_PAGES 1422 bool "4KB" 1423 select HAVE_PAGE_SIZE_4KB 1424 help 1425 This feature enables 4KB pages support. 1426 1427config ARM64_16K_PAGES 1428 bool "16KB" 1429 select HAVE_PAGE_SIZE_16KB 1430 help 1431 The system will use 16KB pages support. AArch32 emulation 1432 requires applications compiled with 16K (or a multiple of 16K) 1433 aligned segments. 1434 1435config ARM64_64K_PAGES 1436 bool "64KB" 1437 select HAVE_PAGE_SIZE_64KB 1438 help 1439 This feature enables 64KB pages support (4KB by default) 1440 allowing only two levels of page tables and faster TLB 1441 look-up. AArch32 emulation requires applications compiled 1442 with 64K aligned segments. 1443 1444endchoice 1445 1446choice 1447 prompt "Virtual address space size" 1448 default ARM64_VA_BITS_52 1449 help 1450 Allows choosing one of multiple possible virtual address 1451 space sizes. The level of translation table is determined by 1452 a combination of page size and virtual address space size. 1453 1454config ARM64_VA_BITS_36 1455 bool "36-bit" if EXPERT 1456 depends on PAGE_SIZE_16KB 1457 1458config ARM64_VA_BITS_39 1459 bool "39-bit" 1460 depends on PAGE_SIZE_4KB 1461 1462config ARM64_VA_BITS_42 1463 bool "42-bit" 1464 depends on PAGE_SIZE_64KB 1465 1466config ARM64_VA_BITS_47 1467 bool "47-bit" 1468 depends on PAGE_SIZE_16KB 1469 1470config ARM64_VA_BITS_48 1471 bool "48-bit" 1472 1473config ARM64_VA_BITS_52 1474 bool "52-bit" 1475 help 1476 Enable 52-bit virtual addressing for userspace when explicitly 1477 requested via a hint to mmap(). The kernel will also use 52-bit 1478 virtual addresses for its own mappings (provided HW support for 1479 this feature is available, otherwise it reverts to 48-bit). 1480 1481 NOTE: Enabling 52-bit virtual addressing in conjunction with 1482 ARMv8.3 Pointer Authentication will result in the PAC being 1483 reduced from 7 bits to 3 bits, which may have a significant 1484 impact on its susceptibility to brute-force attacks. 1485 1486 If unsure, select 48-bit virtual addressing instead. 1487 1488endchoice 1489 1490config ARM64_FORCE_52BIT 1491 bool "Force 52-bit virtual addresses for userspace" 1492 depends on ARM64_VA_BITS_52 && EXPERT 1493 help 1494 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1495 to maintain compatibility with older software by providing 48-bit VAs 1496 unless a hint is supplied to mmap. 1497 1498 This configuration option disables the 48-bit compatibility logic, and 1499 forces all userspace addresses to be 52-bit on HW that supports it. One 1500 should only enable this configuration option for stress testing userspace 1501 memory management code. If unsure say N here. 1502 1503config ARM64_VA_BITS 1504 int 1505 default 36 if ARM64_VA_BITS_36 1506 default 39 if ARM64_VA_BITS_39 1507 default 42 if ARM64_VA_BITS_42 1508 default 47 if ARM64_VA_BITS_47 1509 default 48 if ARM64_VA_BITS_48 1510 default 52 if ARM64_VA_BITS_52 1511 1512choice 1513 prompt "Physical address space size" 1514 default ARM64_PA_BITS_48 1515 help 1516 Choose the maximum physical address range that the kernel will 1517 support. 1518 1519config ARM64_PA_BITS_48 1520 bool "48-bit" 1521 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1522 1523config ARM64_PA_BITS_52 1524 bool "52-bit" 1525 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1526 help 1527 Enable support for a 52-bit physical address space, introduced as 1528 part of the ARMv8.2-LPA extension. 1529 1530 With this enabled, the kernel will also continue to work on CPUs that 1531 do not support ARMv8.2-LPA, but with some added memory overhead (and 1532 minor performance overhead). 1533 1534endchoice 1535 1536config ARM64_PA_BITS 1537 int 1538 default 48 if ARM64_PA_BITS_48 1539 default 52 if ARM64_PA_BITS_52 1540 1541config ARM64_LPA2 1542 def_bool y 1543 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1544 1545choice 1546 prompt "Endianness" 1547 default CPU_LITTLE_ENDIAN 1548 help 1549 Select the endianness of data accesses performed by the CPU. Userspace 1550 applications will need to be compiled and linked for the endianness 1551 that is selected here. 1552 1553config CPU_BIG_ENDIAN 1554 bool "Build big-endian kernel" 1555 depends on BROKEN 1556 help 1557 Say Y if you plan on running a kernel with a big-endian userspace. 1558 1559config CPU_LITTLE_ENDIAN 1560 bool "Build little-endian kernel" 1561 help 1562 Say Y if you plan on running a kernel with a little-endian userspace. 1563 This is usually the case for distributions targeting arm64. 1564 1565endchoice 1566 1567config NR_CPUS 1568 int "Maximum number of CPUs (2-4096)" 1569 range 2 4096 1570 default "512" 1571 1572config HOTPLUG_CPU 1573 bool "Support for hot-pluggable CPUs" 1574 select GENERIC_IRQ_MIGRATION 1575 help 1576 Say Y here to experiment with turning CPUs off and on. CPUs 1577 can be controlled through /sys/devices/system/cpu. 1578 1579# Common NUMA Features 1580config NUMA 1581 bool "NUMA Memory Allocation and Scheduler Support" 1582 select GENERIC_ARCH_NUMA 1583 select OF_NUMA 1584 select HAVE_SETUP_PER_CPU_AREA 1585 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1586 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1587 select USE_PERCPU_NUMA_NODE_ID 1588 help 1589 Enable NUMA (Non-Uniform Memory Access) support. 1590 1591 The kernel will try to allocate memory used by a CPU on the 1592 local memory of the CPU and add some more 1593 NUMA awareness to the kernel. 1594 1595config NODES_SHIFT 1596 int "Maximum NUMA Nodes (as a power of 2)" 1597 range 1 10 1598 default "4" 1599 depends on NUMA 1600 help 1601 Specify the maximum number of NUMA Nodes available on the target 1602 system. Increases memory reserved to accommodate various tables. 1603 1604source "kernel/Kconfig.hz" 1605 1606config ARCH_SPARSEMEM_ENABLE 1607 def_bool y 1608 select SPARSEMEM_VMEMMAP_ENABLE 1609 1610config HW_PERF_EVENTS 1611 def_bool y 1612 depends on ARM_PMU 1613 1614# Supported by clang >= 7.0 or GCC >= 12.0.0 1615config CC_HAVE_SHADOW_CALL_STACK 1616 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1617 1618config PARAVIRT 1619 bool "Enable paravirtualization code" 1620 select HAVE_PV_STEAL_CLOCK_GEN 1621 help 1622 This changes the kernel so it can modify itself when it is run 1623 under a hypervisor, potentially improving performance significantly 1624 over full virtualization. 1625 1626config PARAVIRT_TIME_ACCOUNTING 1627 bool "Paravirtual steal time accounting" 1628 select PARAVIRT 1629 help 1630 Select this option to enable fine granularity task steal time 1631 accounting. Time spent executing other tasks in parallel with 1632 the current vCPU is discounted from the vCPU power. To account for 1633 that, there can be a small performance impact. 1634 1635 If in doubt, say N here. 1636 1637config ARCH_SUPPORTS_KEXEC 1638 def_bool PM_SLEEP_SMP 1639 1640config ARCH_SUPPORTS_KEXEC_FILE 1641 def_bool y 1642 1643config ARCH_SELECTS_KEXEC_FILE 1644 def_bool y 1645 depends on KEXEC_FILE 1646 select HAVE_IMA_KEXEC if IMA 1647 1648config ARCH_SUPPORTS_KEXEC_SIG 1649 def_bool y 1650 1651config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1652 def_bool y 1653 1654config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1655 def_bool y 1656 1657config ARCH_SUPPORTS_KEXEC_HANDOVER 1658 def_bool y 1659 1660config ARCH_SUPPORTS_CRASH_DUMP 1661 def_bool y 1662 1663config ARCH_DEFAULT_CRASH_DUMP 1664 def_bool y 1665 1666config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1667 def_bool CRASH_RESERVE 1668 1669config TRANS_TABLE 1670 def_bool y 1671 depends on HIBERNATION || KEXEC_CORE 1672 1673config XEN_DOM0 1674 def_bool y 1675 depends on XEN 1676 1677config XEN 1678 bool "Xen guest support on ARM64" 1679 depends on ARM64 && OF 1680 select SWIOTLB_XEN 1681 select PARAVIRT 1682 help 1683 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1684 1685# include/linux/mmzone.h requires the following to be true: 1686# 1687# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1688# 1689# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1690# 1691# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1692# ----+-------------------+--------------+----------------------+-------------------------+ 1693# 4K | 27 | 12 | 15 | 10 | 1694# 16K | 27 | 14 | 13 | 11 | 1695# 64K | 29 | 16 | 13 | 13 | 1696config ARCH_FORCE_MAX_ORDER 1697 int 1698 default "13" if ARM64_64K_PAGES 1699 default "11" if ARM64_16K_PAGES 1700 default "10" 1701 help 1702 The kernel page allocator limits the size of maximal physically 1703 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1704 defines the maximal power of two of number of pages that can be 1705 allocated as a single contiguous block. This option allows 1706 overriding the default setting when ability to allocate very 1707 large blocks of physically contiguous memory is required. 1708 1709 The maximal size of allocation cannot exceed the size of the 1710 section, so the value of MAX_PAGE_ORDER should satisfy 1711 1712 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1713 1714 Don't change if unsure. 1715 1716config UNMAP_KERNEL_AT_EL0 1717 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1718 default y 1719 help 1720 Speculation attacks against some high-performance processors can 1721 be used to bypass MMU permission checks and leak kernel data to 1722 userspace. This can be defended against by unmapping the kernel 1723 when running in userspace, mapping it back in on exception entry 1724 via a trampoline page in the vector table. 1725 1726 If unsure, say Y. 1727 1728config MITIGATE_SPECTRE_BRANCH_HISTORY 1729 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1730 default y 1731 help 1732 Speculation attacks against some high-performance processors can 1733 make use of branch history to influence future speculation. 1734 When taking an exception from user-space, a sequence of branches 1735 or a firmware call overwrites the branch history. 1736 1737config ARM64_SW_TTBR0_PAN 1738 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1739 depends on !KCSAN 1740 help 1741 Enabling this option prevents the kernel from accessing 1742 user-space memory directly by pointing TTBR0_EL1 to a reserved 1743 zeroed area and reserved ASID. The user access routines 1744 restore the valid TTBR0_EL1 temporarily. 1745 1746config ARM64_TAGGED_ADDR_ABI 1747 bool "Enable the tagged user addresses syscall ABI" 1748 default y 1749 help 1750 When this option is enabled, user applications can opt in to a 1751 relaxed ABI via prctl() allowing tagged addresses to be passed 1752 to system calls as pointer arguments. For details, see 1753 Documentation/arch/arm64/tagged-address-abi.rst. 1754 1755menuconfig COMPAT 1756 bool "Kernel support for 32-bit EL0" 1757 depends on ARM64_4K_PAGES || EXPERT 1758 select HAVE_UID16 1759 select OLD_SIGSUSPEND3 1760 select COMPAT_OLD_SIGACTION 1761 help 1762 This option enables support for a 32-bit EL0 running under a 64-bit 1763 kernel at EL1. AArch32-specific components such as system calls, 1764 the user helper functions, VFP support and the ptrace interface are 1765 handled appropriately by the kernel. 1766 1767 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1768 that you will only be able to execute AArch32 binaries that were compiled 1769 with page size aligned segments. 1770 1771 If you want to execute 32-bit userspace applications, say Y. 1772 1773if COMPAT 1774 1775config KUSER_HELPERS 1776 bool "Enable kuser helpers page for 32-bit applications" 1777 default y 1778 help 1779 Warning: disabling this option may break 32-bit user programs. 1780 1781 Provide kuser helpers to compat tasks. The kernel provides 1782 helper code to userspace in read only form at a fixed location 1783 to allow userspace to be independent of the CPU type fitted to 1784 the system. This permits binaries to be run on ARMv4 through 1785 to ARMv8 without modification. 1786 1787 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1788 1789 However, the fixed address nature of these helpers can be used 1790 by ROP (return orientated programming) authors when creating 1791 exploits. 1792 1793 If all of the binaries and libraries which run on your platform 1794 are built specifically for your platform, and make no use of 1795 these helpers, then you can turn this option off to hinder 1796 such exploits. However, in that case, if a binary or library 1797 relying on those helpers is run, it will not function correctly. 1798 1799 Say N here only if you are absolutely certain that you do not 1800 need these helpers; otherwise, the safe option is to say Y. 1801 1802config COMPAT_VDSO 1803 bool "Enable vDSO for 32-bit applications" 1804 depends on !CPU_BIG_ENDIAN 1805 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1806 default y 1807 help 1808 Place in the process address space of 32-bit applications an 1809 ELF shared object providing fast implementations of gettimeofday 1810 and clock_gettime. 1811 1812 You must have a 32-bit build of glibc 2.22 or later for programs 1813 to seamlessly take advantage of this. 1814 1815config THUMB2_COMPAT_VDSO 1816 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1817 depends on COMPAT_VDSO 1818 default y 1819 help 1820 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1821 otherwise with '-marm'. 1822 1823config COMPAT_ALIGNMENT_FIXUPS 1824 bool "Fix up misaligned multi-word loads and stores in user space" 1825 1826menuconfig ARMV8_DEPRECATED 1827 bool "Emulate deprecated/obsolete ARMv8 instructions" 1828 depends on SYSCTL 1829 help 1830 Legacy software support may require certain instructions 1831 that have been deprecated or obsoleted in the architecture. 1832 1833 Enable this config to enable selective emulation of these 1834 features. 1835 1836 If unsure, say Y 1837 1838if ARMV8_DEPRECATED 1839 1840config SWP_EMULATION 1841 bool "Emulate SWP/SWPB instructions" 1842 help 1843 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1844 they are always undefined. Say Y here to enable software 1845 emulation of these instructions for userspace using LDXR/STXR. 1846 This feature can be controlled at runtime with the abi.swp 1847 sysctl which is disabled by default. 1848 1849 In some older versions of glibc [<=2.8] SWP is used during futex 1850 trylock() operations with the assumption that the code will not 1851 be preempted. This invalid assumption may be more likely to fail 1852 with SWP emulation enabled, leading to deadlock of the user 1853 application. 1854 1855 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1856 on an external transaction monitoring block called a global 1857 monitor to maintain update atomicity. If your system does not 1858 implement a global monitor, this option can cause programs that 1859 perform SWP operations to uncached memory to deadlock. 1860 1861 If unsure, say Y 1862 1863config CP15_BARRIER_EMULATION 1864 bool "Emulate CP15 Barrier instructions" 1865 help 1866 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1867 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1868 strongly recommended to use the ISB, DSB, and DMB 1869 instructions instead. 1870 1871 Say Y here to enable software emulation of these 1872 instructions for AArch32 userspace code. When this option is 1873 enabled, CP15 barrier usage is traced which can help 1874 identify software that needs updating. This feature can be 1875 controlled at runtime with the abi.cp15_barrier sysctl. 1876 1877 If unsure, say Y 1878 1879config SETEND_EMULATION 1880 bool "Emulate SETEND instruction" 1881 help 1882 The SETEND instruction alters the data-endianness of the 1883 AArch32 EL0, and is deprecated in ARMv8. 1884 1885 Say Y here to enable software emulation of the instruction 1886 for AArch32 userspace code. This feature can be controlled 1887 at runtime with the abi.setend sysctl. 1888 1889 Note: All the cpus on the system must have mixed endian support at EL0 1890 for this feature to be enabled. If a new CPU - which doesn't support mixed 1891 endian - is hotplugged in after this feature has been enabled, there could 1892 be unexpected results in the applications. 1893 1894 If unsure, say Y 1895endif # ARMV8_DEPRECATED 1896 1897endif # COMPAT 1898 1899menu "ARMv8.1 architectural features" 1900 1901config ARM64_HW_AFDBM 1902 bool "Support for hardware updates of the Access and Dirty page flags" 1903 default y 1904 help 1905 The ARMv8.1 architecture extensions introduce support for 1906 hardware updates of the access and dirty information in page 1907 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1908 capable processors, accesses to pages with PTE_AF cleared will 1909 set this bit instead of raising an access flag fault. 1910 Similarly, writes to read-only pages with the DBM bit set will 1911 clear the read-only bit (AP[2]) instead of raising a 1912 permission fault. 1913 1914 Kernels built with this configuration option enabled continue 1915 to work on pre-ARMv8.1 hardware and the performance impact is 1916 minimal. If unsure, say Y. 1917 1918endmenu # "ARMv8.1 architectural features" 1919 1920menu "ARMv8.2 architectural features" 1921 1922config ARM64_PMEM 1923 bool "Enable support for persistent memory" 1924 select ARCH_HAS_PMEM_API 1925 select ARCH_HAS_UACCESS_FLUSHCACHE 1926 help 1927 Say Y to enable support for the persistent memory API based on the 1928 ARMv8.2 DCPoP feature. 1929 1930 The feature is detected at runtime, and the kernel will use DC CVAC 1931 operations if DC CVAP is not supported (following the behaviour of 1932 DC CVAP itself if the system does not define a point of persistence). 1933 1934config ARM64_RAS_EXTN 1935 bool "Enable support for RAS CPU Extensions" 1936 default y 1937 help 1938 CPUs that support the Reliability, Availability and Serviceability 1939 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1940 errors, classify them and report them to software. 1941 1942 On CPUs with these extensions system software can use additional 1943 barriers to determine if faults are pending and read the 1944 classification from a new set of registers. 1945 1946 Selecting this feature will allow the kernel to use these barriers 1947 and access the new registers if the system supports the extension. 1948 Platform RAS features may additionally depend on firmware support. 1949 1950config ARM64_CNP 1951 bool "Enable support for Common Not Private (CNP) translations" 1952 default y 1953 help 1954 Common Not Private (CNP) allows translation table entries to 1955 be shared between different PEs in the same inner shareable 1956 domain, so the hardware can use this fact to optimise the 1957 caching of such entries in the TLB. 1958 1959 Selecting this option allows the CNP feature to be detected 1960 at runtime, and does not affect PEs that do not implement 1961 this feature. 1962 1963endmenu # "ARMv8.2 architectural features" 1964 1965menu "ARMv8.3 architectural features" 1966 1967config ARM64_PTR_AUTH 1968 bool "Enable support for pointer authentication" 1969 default y 1970 help 1971 Pointer authentication (part of the ARMv8.3 Extensions) provides 1972 instructions for signing and authenticating pointers against secret 1973 keys, which can be used to mitigate Return Oriented Programming (ROP) 1974 and other attacks. 1975 1976 This option enables these instructions at EL0 (i.e. for userspace). 1977 Choosing this option will cause the kernel to initialise secret keys 1978 for each process at exec() time, with these keys being 1979 context-switched along with the process. 1980 1981 The feature is detected at runtime. If the feature is not present in 1982 hardware it will not be advertised to userspace/KVM guest nor will it 1983 be enabled. 1984 1985 If the feature is present on the boot CPU but not on a late CPU, then 1986 the late CPU will be parked. Also, if the boot CPU does not have 1987 address auth and the late CPU has then the late CPU will still boot 1988 but with the feature disabled. On such a system, this option should 1989 not be selected. 1990 1991config ARM64_PTR_AUTH_KERNEL 1992 bool "Use pointer authentication for kernel" 1993 default y 1994 depends on ARM64_PTR_AUTH 1995 # Modern compilers insert a .note.gnu.property section note for PAC 1996 # which is only understood by binutils starting with version 2.33.1. 1997 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1998 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1999 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2000 help 2001 If the compiler supports the -mbranch-protection or 2002 -msign-return-address flag (e.g. GCC 7 or later), then this option 2003 will cause the kernel itself to be compiled with return address 2004 protection. In this case, and if the target hardware is known to 2005 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2006 disabled with minimal loss of protection. 2007 2008 This feature works with FUNCTION_GRAPH_TRACER option only if 2009 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2010 2011config CC_HAS_BRANCH_PROT_PAC_RET 2012 # GCC 9 or later, clang 8 or later 2013 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2014 2015config AS_HAS_CFI_NEGATE_RA_STATE 2016 # binutils 2.34+ 2017 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2018 2019endmenu # "ARMv8.3 architectural features" 2020 2021menu "ARMv8.4 architectural features" 2022 2023config ARM64_AMU_EXTN 2024 bool "Enable support for the Activity Monitors Unit CPU extension" 2025 default y 2026 help 2027 The activity monitors extension is an optional extension introduced 2028 by the ARMv8.4 CPU architecture. This enables support for version 1 2029 of the activity monitors architecture, AMUv1. 2030 2031 To enable the use of this extension on CPUs that implement it, say Y. 2032 2033 Note that for architectural reasons, firmware _must_ implement AMU 2034 support when running on CPUs that present the activity monitors 2035 extension. The required support is present in: 2036 * Version 1.5 and later of the ARM Trusted Firmware 2037 2038 For kernels that have this configuration enabled but boot with broken 2039 firmware, you may need to say N here until the firmware is fixed. 2040 Otherwise you may experience firmware panics or lockups when 2041 accessing the counter registers. Even if you are not observing these 2042 symptoms, the values returned by the register reads might not 2043 correctly reflect reality. Most commonly, the value read will be 0, 2044 indicating that the counter is not enabled. 2045 2046config ARM64_TLB_RANGE 2047 bool "Enable support for tlbi range feature" 2048 default y 2049 help 2050 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2051 range of input addresses. 2052 2053config ARM64_MPAM 2054 bool "Enable support for MPAM" 2055 select ARM64_MPAM_DRIVER 2056 select ARCH_HAS_CPU_RESCTRL 2057 help 2058 Memory System Resource Partitioning and Monitoring (MPAM) is an 2059 optional extension to the Arm architecture that allows each 2060 transaction issued to the memory system to be labelled with a 2061 Partition identifier (PARTID) and Performance Monitoring Group 2062 identifier (PMG). 2063 2064 Memory system components, such as the caches, can be configured with 2065 policies to control how much of various physical resources (such as 2066 memory bandwidth or cache memory) the transactions labelled with each 2067 PARTID can consume. Depending on the capabilities of the hardware, 2068 the PARTID and PMG can also be used as filtering criteria to measure 2069 the memory system resource consumption of different parts of a 2070 workload. 2071 2072 Use of this extension requires CPU support, support in the 2073 Memory System Components (MSC), and a description from firmware 2074 of where the MSCs are in the address space. 2075 2076 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2077 2078 This option enables the extra context switch code. 2079 2080endmenu # "ARMv8.4 architectural features" 2081 2082menu "ARMv8.5 architectural features" 2083 2084config AS_HAS_ARMV8_5 2085 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2086 2087config ARM64_BTI 2088 bool "Branch Target Identification support" 2089 default y 2090 help 2091 Branch Target Identification (part of the ARMv8.5 Extensions) 2092 provides a mechanism to limit the set of locations to which computed 2093 branch instructions such as BR or BLR can jump. 2094 2095 To make use of BTI on CPUs that support it, say Y. 2096 2097 BTI is intended to provide complementary protection to other control 2098 flow integrity protection mechanisms, such as the Pointer 2099 authentication mechanism provided as part of the ARMv8.3 Extensions. 2100 For this reason, it does not make sense to enable this option without 2101 also enabling support for pointer authentication. Thus, when 2102 enabling this option you should also select ARM64_PTR_AUTH=y. 2103 2104 Userspace binaries must also be specifically compiled to make use of 2105 this mechanism. If you say N here or the hardware does not support 2106 BTI, such binaries can still run, but you get no additional 2107 enforcement of branch destinations. 2108 2109config ARM64_BTI_KERNEL 2110 bool "Use Branch Target Identification for kernel" 2111 default y 2112 depends on ARM64_BTI 2113 depends on ARM64_PTR_AUTH_KERNEL 2114 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2115 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2116 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2117 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2118 depends on !CC_IS_GCC 2119 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2120 help 2121 Build the kernel with Branch Target Identification annotations 2122 and enable enforcement of this for kernel code. When this option 2123 is enabled and the system supports BTI all kernel code including 2124 modular code must have BTI enabled. 2125 2126config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2127 # GCC 9 or later, clang 8 or later 2128 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2129 2130config ARM64_E0PD 2131 bool "Enable support for E0PD" 2132 default y 2133 help 2134 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2135 that EL0 accesses made via TTBR1 always fault in constant time, 2136 providing similar benefits to KASLR as those provided by KPTI, but 2137 with lower overhead and without disrupting legitimate access to 2138 kernel memory such as SPE. 2139 2140 This option enables E0PD for TTBR1 where available. 2141 2142config ARM64_AS_HAS_MTE 2143 # Initial support for MTE went in binutils 2.32.0, checked with 2144 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2145 # as a late addition to the final architecture spec (LDGM/STGM) 2146 # is only supported in the newer 2.32.x and 2.33 binutils 2147 # versions, hence the extra "stgm" instruction check below. 2148 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2149 2150config ARM64_MTE 2151 bool "Memory Tagging Extension support" 2152 default y 2153 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2154 depends on AS_HAS_ARMV8_5 2155 # Required for tag checking in the uaccess routines 2156 select ARCH_HAS_SUBPAGE_FAULTS 2157 select ARCH_USES_HIGH_VMA_FLAGS 2158 select ARCH_USES_PG_ARCH_2 2159 select ARCH_USES_PG_ARCH_3 2160 help 2161 Memory Tagging (part of the ARMv8.5 Extensions) provides 2162 architectural support for run-time, always-on detection of 2163 various classes of memory error to aid with software debugging 2164 to eliminate vulnerabilities arising from memory-unsafe 2165 languages. 2166 2167 This option enables the support for the Memory Tagging 2168 Extension at EL0 (i.e. for userspace). 2169 2170 Selecting this option allows the feature to be detected at 2171 runtime. Any secondary CPU not implementing this feature will 2172 not be allowed a late bring-up. 2173 2174 Userspace binaries that want to use this feature must 2175 explicitly opt in. The mechanism for the userspace is 2176 described in: 2177 2178 Documentation/arch/arm64/memory-tagging-extension.rst. 2179 2180endmenu # "ARMv8.5 architectural features" 2181 2182menu "ARMv8.7 architectural features" 2183 2184config ARM64_EPAN 2185 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2186 default y 2187 help 2188 Enhanced Privileged Access Never (EPAN) allows Privileged 2189 Access Never to be used with Execute-only mappings. 2190 2191 The feature is detected at runtime, and will remain disabled 2192 if the cpu does not implement the feature. 2193endmenu # "ARMv8.7 architectural features" 2194 2195config AS_HAS_MOPS 2196 def_bool $(as-instr,.arch_extension mops) 2197 2198menu "ARMv8.9 architectural features" 2199 2200config ARM64_POE 2201 prompt "Permission Overlay Extension" 2202 def_bool y 2203 select ARCH_USES_HIGH_VMA_FLAGS 2204 select ARCH_HAS_PKEYS 2205 help 2206 The Permission Overlay Extension is used to implement Memory 2207 Protection Keys. Memory Protection Keys provides a mechanism for 2208 enforcing page-based protections, but without requiring modification 2209 of the page tables when an application changes protection domains. 2210 2211 For details, see Documentation/core-api/protection-keys.rst 2212 2213 If unsure, say y. 2214 2215config ARCH_PKEY_BITS 2216 int 2217 default 3 2218 2219config ARM64_HAFT 2220 bool "Support for Hardware managed Access Flag for Table Descriptors" 2221 depends on ARM64_HW_AFDBM 2222 default y 2223 help 2224 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2225 Flag for Table descriptors. When enabled an architectural executed 2226 memory access will update the Access Flag in each Table descriptor 2227 which is accessed during the translation table walk and for which 2228 the Access Flag is 0. The Access Flag of the Table descriptor use 2229 the same bit of PTE_AF. 2230 2231 The feature will only be enabled if all the CPUs in the system 2232 support this feature. If unsure, say Y. 2233 2234endmenu # "ARMv8.9 architectural features" 2235 2236menu "ARMv9.4 architectural features" 2237 2238config ARM64_GCS 2239 bool "Enable support for Guarded Control Stack (GCS)" 2240 default y 2241 select ARCH_HAS_USER_SHADOW_STACK 2242 select ARCH_USES_HIGH_VMA_FLAGS 2243 help 2244 Guarded Control Stack (GCS) provides support for a separate 2245 stack with restricted access which contains only return 2246 addresses. This can be used to harden against some attacks 2247 by comparing return address used by the program with what is 2248 stored in the GCS, and may also be used to efficiently obtain 2249 the call stack for applications such as profiling. 2250 2251 The feature is detected at runtime, and will remain disabled 2252 if the system does not implement the feature. 2253 2254endmenu # "ARMv9.4 architectural features" 2255 2256config AS_HAS_LSUI 2257 def_bool $(as-instr,.arch_extension lsui) 2258 help 2259 Supported by LLVM 20+ and binutils 2.45+. 2260 2261menu "ARMv9.6 architectural features" 2262 2263config ARM64_LSUI 2264 bool "Support Unprivileged Load Store Instructions (LSUI)" 2265 default y 2266 depends on AS_HAS_LSUI && !CPU_BIG_ENDIAN 2267 help 2268 The Unprivileged Load Store Instructions (LSUI) provides 2269 variants load/store instructions that access user-space memory 2270 from the kernel without clearing PSTATE.PAN bit. 2271 2272 This feature is supported by LLVM 20+ and binutils 2.45+. 2273 2274endmenu # "ARMv9.6 architectural feature" 2275 2276config ARM64_SVE 2277 bool "ARM Scalable Vector Extension support" 2278 default y 2279 help 2280 The Scalable Vector Extension (SVE) is an extension to the AArch64 2281 execution state which complements and extends the SIMD functionality 2282 of the base architecture to support much larger vectors and to enable 2283 additional vectorisation opportunities. 2284 2285 To enable use of this extension on CPUs that implement it, say Y. 2286 2287 On CPUs that support the SVE2 extensions, this option will enable 2288 those too. 2289 2290 Note that for architectural reasons, firmware _must_ implement SVE 2291 support when running on SVE capable hardware. The required support 2292 is present in: 2293 2294 * version 1.5 and later of the ARM Trusted Firmware 2295 * the AArch64 boot wrapper since commit 5e1261e08abf 2296 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2297 2298 For other firmware implementations, consult the firmware documentation 2299 or vendor. 2300 2301 If you need the kernel to boot on SVE-capable hardware with broken 2302 firmware, you may need to say N here until you get your firmware 2303 fixed. Otherwise, you may experience firmware panics or lockups when 2304 booting the kernel. If unsure and you are not observing these 2305 symptoms, you should assume that it is safe to say Y. 2306 2307config AS_HAS_SME 2308 # Supported by LLVM 13+ and binutils 2.38+ 2309 def_bool $(as-instr,.arch_extension sme) 2310 2311config ARM64_SME 2312 bool "ARM Scalable Matrix Extension support" 2313 default y 2314 depends on ARM64_SVE 2315 depends on AS_HAS_SME 2316 help 2317 The Scalable Matrix Extension (SME) is an extension to the AArch64 2318 execution state which utilises a substantial subset of the SVE 2319 instruction set, together with the addition of new architectural 2320 register state capable of holding two dimensional matrix tiles to 2321 enable various matrix operations. 2322 2323config ARM64_PSEUDO_NMI 2324 bool "Support for NMI-like interrupts" 2325 select ARM_GIC_V3 2326 help 2327 Adds support for mimicking Non-Maskable Interrupts through the use of 2328 GIC interrupt priority. This support requires version 3 or later of 2329 ARM GIC. 2330 2331 This high priority configuration for interrupts needs to be 2332 explicitly enabled by setting the kernel parameter 2333 "irqchip.gicv3_pseudo_nmi" to 1. 2334 2335 If unsure, say N 2336 2337if ARM64_PSEUDO_NMI 2338config ARM64_DEBUG_PRIORITY_MASKING 2339 bool "Debug interrupt priority masking" 2340 help 2341 This adds runtime checks to functions enabling/disabling 2342 interrupts when using priority masking. The additional checks verify 2343 the validity of ICC_PMR_EL1 when calling concerned functions. 2344 2345 If unsure, say N 2346endif # ARM64_PSEUDO_NMI 2347 2348config RELOCATABLE 2349 bool "Build a relocatable kernel image" if EXPERT 2350 select ARCH_HAS_RELR 2351 default y 2352 help 2353 This builds the kernel as a Position Independent Executable (PIE), 2354 which retains all relocation metadata required to relocate the 2355 kernel binary at runtime to a different virtual address than the 2356 address it was linked at. 2357 Since AArch64 uses the RELA relocation format, this requires a 2358 relocation pass at runtime even if the kernel is loaded at the 2359 same address it was linked at. 2360 2361config RANDOMIZE_BASE 2362 bool "Randomize the address of the kernel image" 2363 select RELOCATABLE 2364 help 2365 Randomizes the virtual address at which the kernel image is 2366 loaded, as a security feature that deters exploit attempts 2367 relying on knowledge of the location of kernel internals. 2368 2369 It is the bootloader's job to provide entropy, by passing a 2370 random u64 value in /chosen/kaslr-seed at kernel entry. 2371 2372 When booting via the UEFI stub, it will invoke the firmware's 2373 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2374 to the kernel proper. In addition, it will randomise the physical 2375 location of the kernel Image as well. 2376 2377 If unsure, say N. 2378 2379config RANDOMIZE_MODULE_REGION_FULL 2380 bool "Randomize the module region over a 2 GB range" 2381 depends on RANDOMIZE_BASE 2382 default y 2383 help 2384 Randomizes the location of the module region inside a 2 GB window 2385 covering the core kernel. This way, it is less likely for modules 2386 to leak information about the location of core kernel data structures 2387 but it does imply that function calls between modules and the core 2388 kernel will need to be resolved via veneers in the module PLT. 2389 2390 When this option is not set, the module region will be randomized over 2391 a limited range that contains the [_stext, _etext] interval of the 2392 core kernel, so branch relocations are almost always in range unless 2393 the region is exhausted. In this particular case of region 2394 exhaustion, modules might be able to fall back to a larger 2GB area. 2395 2396config CC_HAVE_STACKPROTECTOR_SYSREG 2397 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2398 2399config STACKPROTECTOR_PER_TASK 2400 def_bool y 2401 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2402 2403config UNWIND_PATCH_PAC_INTO_SCS 2404 bool "Enable shadow call stack dynamically using code patching" 2405 depends on CC_IS_CLANG 2406 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2407 depends on SHADOW_CALL_STACK 2408 select UNWIND_TABLES 2409 select DYNAMIC_SCS 2410 2411config ARM64_CONTPTE 2412 bool "Contiguous PTE mappings for user memory" if EXPERT 2413 depends on TRANSPARENT_HUGEPAGE 2414 default y 2415 help 2416 When enabled, user mappings are configured using the PTE contiguous 2417 bit, for any mappings that meet the size and alignment requirements. 2418 This reduces TLB pressure and improves performance. 2419 2420endmenu # "Kernel Features" 2421 2422menu "Boot options" 2423 2424config ARM64_ACPI_PARKING_PROTOCOL 2425 bool "Enable support for the ARM64 ACPI parking protocol" 2426 depends on ACPI 2427 help 2428 Enable support for the ARM64 ACPI parking protocol. If disabled 2429 the kernel will not allow booting through the ARM64 ACPI parking 2430 protocol even if the corresponding data is present in the ACPI 2431 MADT table. 2432 2433config CMDLINE 2434 string "Default kernel command string" 2435 default "" 2436 help 2437 Provide a set of default command-line options at build time by 2438 entering them here. As a minimum, you should specify the 2439 root device (e.g. root=/dev/nfs). 2440 2441choice 2442 prompt "Kernel command line type" 2443 depends on CMDLINE != "" 2444 default CMDLINE_FROM_BOOTLOADER 2445 help 2446 Choose how the kernel will handle the provided default kernel 2447 command line string. 2448 2449config CMDLINE_FROM_BOOTLOADER 2450 bool "Use bootloader kernel arguments if available" 2451 help 2452 Uses the command-line options passed by the boot loader. If 2453 the boot loader doesn't provide any, the default kernel command 2454 string provided in CMDLINE will be used. 2455 2456config CMDLINE_FORCE 2457 bool "Always use the default kernel command string" 2458 help 2459 Always use the default kernel command string, even if the boot 2460 loader passes other arguments to the kernel. 2461 This is useful if you cannot or don't want to change the 2462 command-line options your boot loader passes to the kernel. 2463 2464endchoice 2465 2466config EFI_STUB 2467 bool 2468 2469config EFI 2470 bool "UEFI runtime support" 2471 depends on OF && !CPU_BIG_ENDIAN 2472 depends on KERNEL_MODE_NEON 2473 select ARCH_SUPPORTS_ACPI 2474 select LIBFDT 2475 select UCS2_STRING 2476 select EFI_PARAMS_FROM_FDT 2477 select EFI_RUNTIME_WRAPPERS 2478 select EFI_STUB 2479 select EFI_GENERIC_STUB 2480 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2481 default y 2482 help 2483 This option provides support for runtime services provided 2484 by UEFI firmware (such as non-volatile variables, realtime 2485 clock, and platform reset). A UEFI stub is also provided to 2486 allow the kernel to be booted as an EFI application. This 2487 is only useful on systems that have UEFI firmware. 2488 2489config COMPRESSED_INSTALL 2490 bool "Install compressed image by default" 2491 help 2492 This makes the regular "make install" install the compressed 2493 image we built, not the legacy uncompressed one. 2494 2495 You can check that a compressed image works for you by doing 2496 "make zinstall" first, and verifying that everything is fine 2497 in your environment before making "make install" do this for 2498 you. 2499 2500config DMI 2501 bool "Enable support for SMBIOS (DMI) tables" 2502 depends on EFI 2503 default y 2504 help 2505 This enables SMBIOS/DMI feature for systems. 2506 2507 This option is only useful on systems that have UEFI firmware. 2508 However, even with this option, the resultant kernel should 2509 continue to boot on existing non-UEFI platforms. 2510 2511endmenu # "Boot options" 2512 2513menu "Power management options" 2514 2515source "kernel/power/Kconfig" 2516 2517config ARCH_HIBERNATION_POSSIBLE 2518 def_bool y 2519 depends on CPU_PM 2520 2521config ARCH_HIBERNATION_HEADER 2522 def_bool y 2523 depends on HIBERNATION 2524 2525config ARCH_SUSPEND_POSSIBLE 2526 def_bool y 2527 2528endmenu # "Power management options" 2529 2530menu "CPU Power Management" 2531 2532source "drivers/cpuidle/Kconfig" 2533 2534source "drivers/cpufreq/Kconfig" 2535 2536endmenu # "CPU Power Management" 2537 2538source "drivers/acpi/Kconfig" 2539 2540source "arch/arm64/kvm/Kconfig" 2541 2542source "kernel/livepatch/Kconfig" 2543