1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_CCA_REQUIRED if ACPI 5 select ACPI_GENERIC_GSI if ACPI 6 select ACPI_GTDT if ACPI 7 select ACPI_IORT if ACPI 8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 9 select ACPI_MCFG if (ACPI && PCI) 10 select ACPI_SPCR_TABLE if ACPI 11 select ACPI_PPTT if ACPI 12 select ARCH_HAS_DEBUG_WX 13 select ARCH_BINFMT_ELF_EXTRA_PHDRS 14 select ARCH_BINFMT_ELF_STATE 15 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 17 select ARCH_ENABLE_MEMORY_HOTPLUG 18 select ARCH_ENABLE_MEMORY_HOTREMOVE 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_CURRENT_STACK_POINTER 23 select ARCH_HAS_DEBUG_VIRTUAL 24 select ARCH_HAS_DEBUG_VM_PGTABLE 25 select ARCH_HAS_DMA_PREP_COHERENT 26 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 27 select ARCH_HAS_FAST_MULTIPLIER 28 select ARCH_HAS_FORTIFY_SOURCE 29 select ARCH_HAS_GCOV_PROFILE_ALL 30 select ARCH_HAS_GIGANTIC_PAGE 31 select ARCH_HAS_KCOV 32 select ARCH_HAS_KEEPINITRD 33 select ARCH_HAS_MEMBARRIER_SYNC_CORE 34 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 35 select ARCH_HAS_PTE_DEVMAP 36 select ARCH_HAS_PTE_SPECIAL 37 select ARCH_HAS_SETUP_DMA_OPS 38 select ARCH_HAS_SET_DIRECT_MAP 39 select ARCH_HAS_SET_MEMORY 40 select ARCH_STACKWALK 41 select ARCH_HAS_STRICT_KERNEL_RWX 42 select ARCH_HAS_STRICT_MODULE_RWX 43 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 44 select ARCH_HAS_SYNC_DMA_FOR_CPU 45 select ARCH_HAS_SYSCALL_WRAPPER 46 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 47 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 48 select ARCH_HAS_ZONE_DMA_SET if EXPERT 49 select ARCH_HAVE_ELF_PROT 50 select ARCH_HAVE_NMI_SAFE_CMPXCHG 51 select ARCH_HAVE_TRACE_MMIO_ACCESS 52 select ARCH_INLINE_READ_LOCK if !PREEMPTION 53 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 54 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 55 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 56 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 57 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 58 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 59 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 60 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 61 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 62 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 63 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 64 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 65 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 66 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 67 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 68 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 69 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 70 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 71 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 72 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 73 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 74 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 75 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 76 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 77 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 78 select ARCH_KEEP_MEMBLOCK 79 select ARCH_USE_CMPXCHG_LOCKREF 80 select ARCH_USE_GNU_PROPERTY 81 select ARCH_USE_MEMTEST 82 select ARCH_USE_QUEUED_RWLOCKS 83 select ARCH_USE_QUEUED_SPINLOCKS 84 select ARCH_USE_SYM_ANNOTATIONS 85 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 86 select ARCH_SUPPORTS_HUGETLBFS 87 select ARCH_SUPPORTS_MEMORY_FAILURE 88 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 89 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 90 select ARCH_SUPPORTS_LTO_CLANG_THIN 91 select ARCH_SUPPORTS_CFI_CLANG 92 select ARCH_SUPPORTS_ATOMIC_RMW 93 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 94 select ARCH_SUPPORTS_NUMA_BALANCING 95 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 96 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 97 select ARCH_WANT_DEFAULT_BPF_JIT 98 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 99 select ARCH_WANT_FRAME_POINTERS 100 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 101 select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP 102 select ARCH_WANT_LD_ORPHAN_WARN 103 select ARCH_WANTS_NO_INSTR 104 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 105 select ARCH_HAS_UBSAN_SANITIZE_ALL 106 select ARM_AMBA 107 select ARM_ARCH_TIMER 108 select ARM_GIC 109 select AUDIT_ARCH_COMPAT_GENERIC 110 select ARM_GIC_V2M if PCI 111 select ARM_GIC_V3 112 select ARM_GIC_V3_ITS if PCI 113 select ARM_PSCI_FW 114 select BUILDTIME_TABLE_SORT 115 select CLONE_BACKWARDS 116 select COMMON_CLK 117 select CPU_PM if (SUSPEND || CPU_IDLE) 118 select CRC32 119 select DCACHE_WORD_ACCESS 120 select DMA_DIRECT_REMAP 121 select EDAC_SUPPORT 122 select FRAME_POINTER 123 select GENERIC_ALLOCATOR 124 select GENERIC_ARCH_TOPOLOGY 125 select GENERIC_CLOCKEVENTS_BROADCAST 126 select GENERIC_CPU_AUTOPROBE 127 select GENERIC_CPU_VULNERABILITIES 128 select GENERIC_EARLY_IOREMAP 129 select GENERIC_IDLE_POLL_SETUP 130 select GENERIC_IOREMAP 131 select GENERIC_IRQ_IPI 132 select GENERIC_IRQ_PROBE 133 select GENERIC_IRQ_SHOW 134 select GENERIC_IRQ_SHOW_LEVEL 135 select GENERIC_LIB_DEVMEM_IS_ALLOWED 136 select GENERIC_PCI_IOMAP 137 select GENERIC_PTDUMP 138 select GENERIC_SCHED_CLOCK 139 select GENERIC_SMP_IDLE_THREAD 140 select GENERIC_TIME_VSYSCALL 141 select GENERIC_GETTIMEOFDAY 142 select GENERIC_VDSO_TIME_NS 143 select HARDIRQS_SW_RESEND 144 select HAVE_MOVE_PMD 145 select HAVE_MOVE_PUD 146 select HAVE_PCI 147 select HAVE_ACPI_APEI if (ACPI && EFI) 148 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 149 select HAVE_ARCH_AUDITSYSCALL 150 select HAVE_ARCH_BITREVERSE 151 select HAVE_ARCH_COMPILER_H 152 select HAVE_ARCH_HUGE_VMAP 153 select HAVE_ARCH_JUMP_LABEL 154 select HAVE_ARCH_JUMP_LABEL_RELATIVE 155 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 156 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 157 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 158 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 159 # Some instrumentation may be unsound, hence EXPERT 160 select HAVE_ARCH_KCSAN if EXPERT 161 select HAVE_ARCH_KFENCE 162 select HAVE_ARCH_KGDB 163 select HAVE_ARCH_MMAP_RND_BITS 164 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 165 select HAVE_ARCH_PREL32_RELOCATIONS 166 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 167 select HAVE_ARCH_SECCOMP_FILTER 168 select HAVE_ARCH_STACKLEAK 169 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 170 select HAVE_ARCH_TRACEHOOK 171 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 172 select HAVE_ARCH_VMAP_STACK 173 select HAVE_ARM_SMCCC 174 select HAVE_ASM_MODVERSIONS 175 select HAVE_EBPF_JIT 176 select HAVE_C_RECORDMCOUNT 177 select HAVE_CMPXCHG_DOUBLE 178 select HAVE_CMPXCHG_LOCAL 179 select HAVE_CONTEXT_TRACKING_USER 180 select HAVE_DEBUG_KMEMLEAK 181 select HAVE_DMA_CONTIGUOUS 182 select HAVE_DYNAMIC_FTRACE 183 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 184 if DYNAMIC_FTRACE_WITH_REGS 185 select HAVE_EFFICIENT_UNALIGNED_ACCESS 186 select HAVE_FAST_GUP 187 select HAVE_FTRACE_MCOUNT_RECORD 188 select HAVE_FUNCTION_TRACER 189 select HAVE_FUNCTION_ERROR_INJECTION 190 select HAVE_FUNCTION_GRAPH_TRACER 191 select HAVE_GCC_PLUGINS 192 select HAVE_HW_BREAKPOINT if PERF_EVENTS 193 select HAVE_IOREMAP_PROT 194 select HAVE_IRQ_TIME_ACCOUNTING 195 select HAVE_KVM 196 select HAVE_NMI 197 select HAVE_PATA_PLATFORM 198 select HAVE_PERF_EVENTS 199 select HAVE_PERF_REGS 200 select HAVE_PERF_USER_STACK_DUMP 201 select HAVE_PREEMPT_DYNAMIC_KEY 202 select HAVE_REGS_AND_STACK_ACCESS_API 203 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 204 select HAVE_FUNCTION_ARG_ACCESS_API 205 select MMU_GATHER_RCU_TABLE_FREE 206 select HAVE_RSEQ 207 select HAVE_STACKPROTECTOR 208 select HAVE_SYSCALL_TRACEPOINTS 209 select HAVE_KPROBES 210 select HAVE_KRETPROBES 211 select HAVE_GENERIC_VDSO 212 select IOMMU_DMA if IOMMU_SUPPORT 213 select IRQ_DOMAIN 214 select IRQ_FORCED_THREADING 215 select KASAN_VMALLOC if KASAN 216 select MODULES_USE_ELF_RELA 217 select NEED_DMA_MAP_STATE 218 select NEED_SG_DMA_LENGTH 219 select OF 220 select OF_EARLY_FLATTREE 221 select PCI_DOMAINS_GENERIC if PCI 222 select PCI_ECAM if (ACPI && PCI) 223 select PCI_SYSCALL if PCI 224 select POWER_RESET 225 select POWER_SUPPLY 226 select SPARSE_IRQ 227 select SWIOTLB 228 select SYSCTL_EXCEPTION_TRACE 229 select THREAD_INFO_IN_TASK 230 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 231 select TRACE_IRQFLAGS_SUPPORT 232 select TRACE_IRQFLAGS_NMI_SUPPORT 233 help 234 ARM 64-bit (AArch64) Linux support. 235 236config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_REGS 237 def_bool CC_IS_CLANG 238 # https://github.com/ClangBuiltLinux/linux/issues/1507 239 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 240 select HAVE_DYNAMIC_FTRACE_WITH_REGS 241 242config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_REGS 243 def_bool CC_IS_GCC 244 depends on $(cc-option,-fpatchable-function-entry=2) 245 select HAVE_DYNAMIC_FTRACE_WITH_REGS 246 247config 64BIT 248 def_bool y 249 250config MMU 251 def_bool y 252 253config ARM64_PAGE_SHIFT 254 int 255 default 16 if ARM64_64K_PAGES 256 default 14 if ARM64_16K_PAGES 257 default 12 258 259config ARM64_CONT_PTE_SHIFT 260 int 261 default 5 if ARM64_64K_PAGES 262 default 7 if ARM64_16K_PAGES 263 default 4 264 265config ARM64_CONT_PMD_SHIFT 266 int 267 default 5 if ARM64_64K_PAGES 268 default 5 if ARM64_16K_PAGES 269 default 4 270 271config ARCH_MMAP_RND_BITS_MIN 272 default 14 if ARM64_64K_PAGES 273 default 16 if ARM64_16K_PAGES 274 default 18 275 276# max bits determined by the following formula: 277# VA_BITS - PAGE_SHIFT - 3 278config ARCH_MMAP_RND_BITS_MAX 279 default 19 if ARM64_VA_BITS=36 280 default 24 if ARM64_VA_BITS=39 281 default 27 if ARM64_VA_BITS=42 282 default 30 if ARM64_VA_BITS=47 283 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 284 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 285 default 33 if ARM64_VA_BITS=48 286 default 14 if ARM64_64K_PAGES 287 default 16 if ARM64_16K_PAGES 288 default 18 289 290config ARCH_MMAP_RND_COMPAT_BITS_MIN 291 default 7 if ARM64_64K_PAGES 292 default 9 if ARM64_16K_PAGES 293 default 11 294 295config ARCH_MMAP_RND_COMPAT_BITS_MAX 296 default 16 297 298config NO_IOPORT_MAP 299 def_bool y if !PCI 300 301config STACKTRACE_SUPPORT 302 def_bool y 303 304config ILLEGAL_POINTER_VALUE 305 hex 306 default 0xdead000000000000 307 308config LOCKDEP_SUPPORT 309 def_bool y 310 311config GENERIC_BUG 312 def_bool y 313 depends on BUG 314 315config GENERIC_BUG_RELATIVE_POINTERS 316 def_bool y 317 depends on GENERIC_BUG 318 319config GENERIC_HWEIGHT 320 def_bool y 321 322config GENERIC_CSUM 323 def_bool y 324 325config GENERIC_CALIBRATE_DELAY 326 def_bool y 327 328config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 329 def_bool y 330 331config SMP 332 def_bool y 333 334config KERNEL_MODE_NEON 335 def_bool y 336 337config FIX_EARLYCON_MEM 338 def_bool y 339 340config PGTABLE_LEVELS 341 int 342 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 343 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 344 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 345 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 346 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 347 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 348 349config ARCH_SUPPORTS_UPROBES 350 def_bool y 351 352config ARCH_PROC_KCORE_TEXT 353 def_bool y 354 355config BROKEN_GAS_INST 356 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 357 358config KASAN_SHADOW_OFFSET 359 hex 360 depends on KASAN_GENERIC || KASAN_SW_TAGS 361 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 362 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 363 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 364 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 365 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 366 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 367 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 368 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 369 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 370 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 371 default 0xffffffffffffffff 372 373source "arch/arm64/Kconfig.platforms" 374 375menu "Kernel Features" 376 377menu "ARM errata workarounds via the alternatives framework" 378 379config ARM64_WORKAROUND_CLEAN_CACHE 380 bool 381 382config ARM64_ERRATUM_826319 383 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 384 default y 385 select ARM64_WORKAROUND_CLEAN_CACHE 386 help 387 This option adds an alternative code sequence to work around ARM 388 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 389 AXI master interface and an L2 cache. 390 391 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 392 and is unable to accept a certain write via this interface, it will 393 not progress on read data presented on the read data channel and the 394 system can deadlock. 395 396 The workaround promotes data cache clean instructions to 397 data cache clean-and-invalidate. 398 Please note that this does not necessarily enable the workaround, 399 as it depends on the alternative framework, which will only patch 400 the kernel if an affected CPU is detected. 401 402 If unsure, say Y. 403 404config ARM64_ERRATUM_827319 405 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 406 default y 407 select ARM64_WORKAROUND_CLEAN_CACHE 408 help 409 This option adds an alternative code sequence to work around ARM 410 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 411 master interface and an L2 cache. 412 413 Under certain conditions this erratum can cause a clean line eviction 414 to occur at the same time as another transaction to the same address 415 on the AMBA 5 CHI interface, which can cause data corruption if the 416 interconnect reorders the two transactions. 417 418 The workaround promotes data cache clean instructions to 419 data cache clean-and-invalidate. 420 Please note that this does not necessarily enable the workaround, 421 as it depends on the alternative framework, which will only patch 422 the kernel if an affected CPU is detected. 423 424 If unsure, say Y. 425 426config ARM64_ERRATUM_824069 427 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 428 default y 429 select ARM64_WORKAROUND_CLEAN_CACHE 430 help 431 This option adds an alternative code sequence to work around ARM 432 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 433 to a coherent interconnect. 434 435 If a Cortex-A53 processor is executing a store or prefetch for 436 write instruction at the same time as a processor in another 437 cluster is executing a cache maintenance operation to the same 438 address, then this erratum might cause a clean cache line to be 439 incorrectly marked as dirty. 440 441 The workaround promotes data cache clean instructions to 442 data cache clean-and-invalidate. 443 Please note that this option does not necessarily enable the 444 workaround, as it depends on the alternative framework, which will 445 only patch the kernel if an affected CPU is detected. 446 447 If unsure, say Y. 448 449config ARM64_ERRATUM_819472 450 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 451 default y 452 select ARM64_WORKAROUND_CLEAN_CACHE 453 help 454 This option adds an alternative code sequence to work around ARM 455 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 456 present when it is connected to a coherent interconnect. 457 458 If the processor is executing a load and store exclusive sequence at 459 the same time as a processor in another cluster is executing a cache 460 maintenance operation to the same address, then this erratum might 461 cause data corruption. 462 463 The workaround promotes data cache clean instructions to 464 data cache clean-and-invalidate. 465 Please note that this does not necessarily enable the workaround, 466 as it depends on the alternative framework, which will only patch 467 the kernel if an affected CPU is detected. 468 469 If unsure, say Y. 470 471config ARM64_ERRATUM_832075 472 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 473 default y 474 help 475 This option adds an alternative code sequence to work around ARM 476 erratum 832075 on Cortex-A57 parts up to r1p2. 477 478 Affected Cortex-A57 parts might deadlock when exclusive load/store 479 instructions to Write-Back memory are mixed with Device loads. 480 481 The workaround is to promote device loads to use Load-Acquire 482 semantics. 483 Please note that this does not necessarily enable the workaround, 484 as it depends on the alternative framework, which will only patch 485 the kernel if an affected CPU is detected. 486 487 If unsure, say Y. 488 489config ARM64_ERRATUM_834220 490 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 491 depends on KVM 492 default y 493 help 494 This option adds an alternative code sequence to work around ARM 495 erratum 834220 on Cortex-A57 parts up to r1p2. 496 497 Affected Cortex-A57 parts might report a Stage 2 translation 498 fault as the result of a Stage 1 fault for load crossing a 499 page boundary when there is a permission or device memory 500 alignment fault at Stage 1 and a translation fault at Stage 2. 501 502 The workaround is to verify that the Stage 1 translation 503 doesn't generate a fault before handling the Stage 2 fault. 504 Please note that this does not necessarily enable the workaround, 505 as it depends on the alternative framework, which will only patch 506 the kernel if an affected CPU is detected. 507 508 If unsure, say Y. 509 510config ARM64_ERRATUM_1742098 511 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 512 depends on COMPAT 513 default y 514 help 515 This option removes the AES hwcap for aarch32 user-space to 516 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 517 518 Affected parts may corrupt the AES state if an interrupt is 519 taken between a pair of AES instructions. These instructions 520 are only present if the cryptography extensions are present. 521 All software should have a fallback implementation for CPUs 522 that don't implement the cryptography extensions. 523 524 If unsure, say Y. 525 526config ARM64_ERRATUM_845719 527 bool "Cortex-A53: 845719: a load might read incorrect data" 528 depends on COMPAT 529 default y 530 help 531 This option adds an alternative code sequence to work around ARM 532 erratum 845719 on Cortex-A53 parts up to r0p4. 533 534 When running a compat (AArch32) userspace on an affected Cortex-A53 535 part, a load at EL0 from a virtual address that matches the bottom 32 536 bits of the virtual address used by a recent load at (AArch64) EL1 537 might return incorrect data. 538 539 The workaround is to write the contextidr_el1 register on exception 540 return to a 32-bit task. 541 Please note that this does not necessarily enable the workaround, 542 as it depends on the alternative framework, which will only patch 543 the kernel if an affected CPU is detected. 544 545 If unsure, say Y. 546 547config ARM64_ERRATUM_843419 548 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 549 default y 550 select ARM64_MODULE_PLTS if MODULES 551 help 552 This option links the kernel with '--fix-cortex-a53-843419' and 553 enables PLT support to replace certain ADRP instructions, which can 554 cause subsequent memory accesses to use an incorrect address on 555 Cortex-A53 parts up to r0p4. 556 557 If unsure, say Y. 558 559config ARM64_LD_HAS_FIX_ERRATUM_843419 560 def_bool $(ld-option,--fix-cortex-a53-843419) 561 562config ARM64_ERRATUM_1024718 563 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 564 default y 565 help 566 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 567 568 Affected Cortex-A55 cores (all revisions) could cause incorrect 569 update of the hardware dirty bit when the DBM/AP bits are updated 570 without a break-before-make. The workaround is to disable the usage 571 of hardware DBM locally on the affected cores. CPUs not affected by 572 this erratum will continue to use the feature. 573 574 If unsure, say Y. 575 576config ARM64_ERRATUM_1418040 577 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 578 default y 579 depends on COMPAT 580 help 581 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 582 errata 1188873 and 1418040. 583 584 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 585 cause register corruption when accessing the timer registers 586 from AArch32 userspace. 587 588 If unsure, say Y. 589 590config ARM64_WORKAROUND_SPECULATIVE_AT 591 bool 592 593config ARM64_ERRATUM_1165522 594 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 595 default y 596 select ARM64_WORKAROUND_SPECULATIVE_AT 597 help 598 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 599 600 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 601 corrupted TLBs by speculating an AT instruction during a guest 602 context switch. 603 604 If unsure, say Y. 605 606config ARM64_ERRATUM_1319367 607 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 608 default y 609 select ARM64_WORKAROUND_SPECULATIVE_AT 610 help 611 This option adds work arounds for ARM Cortex-A57 erratum 1319537 612 and A72 erratum 1319367 613 614 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 615 speculating an AT instruction during a guest context switch. 616 617 If unsure, say Y. 618 619config ARM64_ERRATUM_1530923 620 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 621 default y 622 select ARM64_WORKAROUND_SPECULATIVE_AT 623 help 624 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 625 626 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 627 corrupted TLBs by speculating an AT instruction during a guest 628 context switch. 629 630 If unsure, say Y. 631 632config ARM64_WORKAROUND_REPEAT_TLBI 633 bool 634 635config ARM64_ERRATUM_1286807 636 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 637 default y 638 select ARM64_WORKAROUND_REPEAT_TLBI 639 help 640 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 641 642 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 643 address for a cacheable mapping of a location is being 644 accessed by a core while another core is remapping the virtual 645 address to a new physical page using the recommended 646 break-before-make sequence, then under very rare circumstances 647 TLBI+DSB completes before a read using the translation being 648 invalidated has been observed by other observers. The 649 workaround repeats the TLBI+DSB operation. 650 651config ARM64_ERRATUM_1463225 652 bool "Cortex-A76: Software Step might prevent interrupt recognition" 653 default y 654 help 655 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 656 657 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 658 of a system call instruction (SVC) can prevent recognition of 659 subsequent interrupts when software stepping is disabled in the 660 exception handler of the system call and either kernel debugging 661 is enabled or VHE is in use. 662 663 Work around the erratum by triggering a dummy step exception 664 when handling a system call from a task that is being stepped 665 in a VHE configuration of the kernel. 666 667 If unsure, say Y. 668 669config ARM64_ERRATUM_1542419 670 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 671 default y 672 help 673 This option adds a workaround for ARM Neoverse-N1 erratum 674 1542419. 675 676 Affected Neoverse-N1 cores could execute a stale instruction when 677 modified by another CPU. The workaround depends on a firmware 678 counterpart. 679 680 Workaround the issue by hiding the DIC feature from EL0. This 681 forces user-space to perform cache maintenance. 682 683 If unsure, say Y. 684 685config ARM64_ERRATUM_1508412 686 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 687 default y 688 help 689 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 690 691 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 692 of a store-exclusive or read of PAR_EL1 and a load with device or 693 non-cacheable memory attributes. The workaround depends on a firmware 694 counterpart. 695 696 KVM guests must also have the workaround implemented or they can 697 deadlock the system. 698 699 Work around the issue by inserting DMB SY barriers around PAR_EL1 700 register reads and warning KVM users. The DMB barrier is sufficient 701 to prevent a speculative PAR_EL1 read. 702 703 If unsure, say Y. 704 705config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 706 bool 707 708config ARM64_ERRATUM_2051678 709 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 710 default y 711 help 712 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 713 Affected Cortex-A510 might not respect the ordering rules for 714 hardware update of the page table's dirty bit. The workaround 715 is to not enable the feature on affected CPUs. 716 717 If unsure, say Y. 718 719config ARM64_ERRATUM_2077057 720 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 721 default y 722 help 723 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 724 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 725 expected, but a Pointer Authentication trap is taken instead. The 726 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 727 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 728 729 This can only happen when EL2 is stepping EL1. 730 731 When these conditions occur, the SPSR_EL2 value is unchanged from the 732 previous guest entry, and can be restored from the in-memory copy. 733 734 If unsure, say Y. 735 736config ARM64_ERRATUM_2119858 737 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 738 default y 739 depends on CORESIGHT_TRBE 740 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 741 help 742 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 743 744 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 745 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 746 the event of a WRAP event. 747 748 Work around the issue by always making sure we move the TRBPTR_EL1 by 749 256 bytes before enabling the buffer and filling the first 256 bytes of 750 the buffer with ETM ignore packets upon disabling. 751 752 If unsure, say Y. 753 754config ARM64_ERRATUM_2139208 755 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 756 default y 757 depends on CORESIGHT_TRBE 758 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 759 help 760 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 761 762 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 763 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 764 the event of a WRAP event. 765 766 Work around the issue by always making sure we move the TRBPTR_EL1 by 767 256 bytes before enabling the buffer and filling the first 256 bytes of 768 the buffer with ETM ignore packets upon disabling. 769 770 If unsure, say Y. 771 772config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 773 bool 774 775config ARM64_ERRATUM_2054223 776 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 777 default y 778 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 779 help 780 Enable workaround for ARM Cortex-A710 erratum 2054223 781 782 Affected cores may fail to flush the trace data on a TSB instruction, when 783 the PE is in trace prohibited state. This will cause losing a few bytes 784 of the trace cached. 785 786 Workaround is to issue two TSB consecutively on affected cores. 787 788 If unsure, say Y. 789 790config ARM64_ERRATUM_2067961 791 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 792 default y 793 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 794 help 795 Enable workaround for ARM Neoverse-N2 erratum 2067961 796 797 Affected cores may fail to flush the trace data on a TSB instruction, when 798 the PE is in trace prohibited state. This will cause losing a few bytes 799 of the trace cached. 800 801 Workaround is to issue two TSB consecutively on affected cores. 802 803 If unsure, say Y. 804 805config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 806 bool 807 808config ARM64_ERRATUM_2253138 809 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 810 depends on CORESIGHT_TRBE 811 default y 812 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 813 help 814 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 815 816 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 817 for TRBE. Under some conditions, the TRBE might generate a write to the next 818 virtually addressed page following the last page of the TRBE address space 819 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 820 821 Work around this in the driver by always making sure that there is a 822 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 823 824 If unsure, say Y. 825 826config ARM64_ERRATUM_2224489 827 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 828 depends on CORESIGHT_TRBE 829 default y 830 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 831 help 832 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 833 834 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 835 for TRBE. Under some conditions, the TRBE might generate a write to the next 836 virtually addressed page following the last page of the TRBE address space 837 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 838 839 Work around this in the driver by always making sure that there is a 840 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 841 842 If unsure, say Y. 843 844config ARM64_ERRATUM_2441009 845 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 846 default y 847 select ARM64_WORKAROUND_REPEAT_TLBI 848 help 849 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 850 851 Under very rare circumstances, affected Cortex-A510 CPUs 852 may not handle a race between a break-before-make sequence on one 853 CPU, and another CPU accessing the same page. This could allow a 854 store to a page that has been unmapped. 855 856 Work around this by adding the affected CPUs to the list that needs 857 TLB sequences to be done twice. 858 859 If unsure, say Y. 860 861config ARM64_ERRATUM_2064142 862 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 863 depends on CORESIGHT_TRBE 864 default y 865 help 866 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 867 868 Affected Cortex-A510 core might fail to write into system registers after the 869 TRBE has been disabled. Under some conditions after the TRBE has been disabled 870 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 871 and TRBTRG_EL1 will be ignored and will not be effected. 872 873 Work around this in the driver by executing TSB CSYNC and DSB after collection 874 is stopped and before performing a system register write to one of the affected 875 registers. 876 877 If unsure, say Y. 878 879config ARM64_ERRATUM_2038923 880 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 881 depends on CORESIGHT_TRBE 882 default y 883 help 884 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 885 886 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 887 prohibited within the CPU. As a result, the trace buffer or trace buffer state 888 might be corrupted. This happens after TRBE buffer has been enabled by setting 889 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 890 execution changes from a context, in which trace is prohibited to one where it 891 isn't, or vice versa. In these mentioned conditions, the view of whether trace 892 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 893 the trace buffer state might be corrupted. 894 895 Work around this in the driver by preventing an inconsistent view of whether the 896 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 897 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 898 two ISB instructions if no ERET is to take place. 899 900 If unsure, say Y. 901 902config ARM64_ERRATUM_1902691 903 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 904 depends on CORESIGHT_TRBE 905 default y 906 help 907 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 908 909 Affected Cortex-A510 core might cause trace data corruption, when being written 910 into the memory. Effectively TRBE is broken and hence cannot be used to capture 911 trace data. 912 913 Work around this problem in the driver by just preventing TRBE initialization on 914 affected cpus. The firmware must have disabled the access to TRBE for the kernel 915 on such implementations. This will cover the kernel for any firmware that doesn't 916 do this already. 917 918 If unsure, say Y. 919 920config CAVIUM_ERRATUM_22375 921 bool "Cavium erratum 22375, 24313" 922 default y 923 help 924 Enable workaround for errata 22375 and 24313. 925 926 This implements two gicv3-its errata workarounds for ThunderX. Both 927 with a small impact affecting only ITS table allocation. 928 929 erratum 22375: only alloc 8MB table size 930 erratum 24313: ignore memory access type 931 932 The fixes are in ITS initialization and basically ignore memory access 933 type and table size provided by the TYPER and BASER registers. 934 935 If unsure, say Y. 936 937config CAVIUM_ERRATUM_23144 938 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 939 depends on NUMA 940 default y 941 help 942 ITS SYNC command hang for cross node io and collections/cpu mapping. 943 944 If unsure, say Y. 945 946config CAVIUM_ERRATUM_23154 947 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 948 default y 949 help 950 The ThunderX GICv3 implementation requires a modified version for 951 reading the IAR status to ensure data synchronization 952 (access to icc_iar1_el1 is not sync'ed before and after). 953 954 It also suffers from erratum 38545 (also present on Marvell's 955 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 956 spuriously presented to the CPU interface. 957 958 If unsure, say Y. 959 960config CAVIUM_ERRATUM_27456 961 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 962 default y 963 help 964 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 965 instructions may cause the icache to become corrupted if it 966 contains data for a non-current ASID. The fix is to 967 invalidate the icache when changing the mm context. 968 969 If unsure, say Y. 970 971config CAVIUM_ERRATUM_30115 972 bool "Cavium erratum 30115: Guest may disable interrupts in host" 973 default y 974 help 975 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 976 1.2, and T83 Pass 1.0, KVM guest execution may disable 977 interrupts in host. Trapping both GICv3 group-0 and group-1 978 accesses sidesteps the issue. 979 980 If unsure, say Y. 981 982config CAVIUM_TX2_ERRATUM_219 983 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 984 default y 985 help 986 On Cavium ThunderX2, a load, store or prefetch instruction between a 987 TTBR update and the corresponding context synchronizing operation can 988 cause a spurious Data Abort to be delivered to any hardware thread in 989 the CPU core. 990 991 Work around the issue by avoiding the problematic code sequence and 992 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 993 trap handler performs the corresponding register access, skips the 994 instruction and ensures context synchronization by virtue of the 995 exception return. 996 997 If unsure, say Y. 998 999config FUJITSU_ERRATUM_010001 1000 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1001 default y 1002 help 1003 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1004 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1005 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1006 This fault occurs under a specific hardware condition when a 1007 load/store instruction performs an address translation using: 1008 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1009 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1010 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1011 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1012 1013 The workaround is to ensure these bits are clear in TCR_ELx. 1014 The workaround only affects the Fujitsu-A64FX. 1015 1016 If unsure, say Y. 1017 1018config HISILICON_ERRATUM_161600802 1019 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1020 default y 1021 help 1022 The HiSilicon Hip07 SoC uses the wrong redistributor base 1023 when issued ITS commands such as VMOVP and VMAPP, and requires 1024 a 128kB offset to be applied to the target address in this commands. 1025 1026 If unsure, say Y. 1027 1028config QCOM_FALKOR_ERRATUM_1003 1029 bool "Falkor E1003: Incorrect translation due to ASID change" 1030 default y 1031 help 1032 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1033 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1034 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1035 then only for entries in the walk cache, since the leaf translation 1036 is unchanged. Work around the erratum by invalidating the walk cache 1037 entries for the trampoline before entering the kernel proper. 1038 1039config QCOM_FALKOR_ERRATUM_1009 1040 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1041 default y 1042 select ARM64_WORKAROUND_REPEAT_TLBI 1043 help 1044 On Falkor v1, the CPU may prematurely complete a DSB following a 1045 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1046 one more time to fix the issue. 1047 1048 If unsure, say Y. 1049 1050config QCOM_QDF2400_ERRATUM_0065 1051 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1052 default y 1053 help 1054 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1055 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1056 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1057 1058 If unsure, say Y. 1059 1060config QCOM_FALKOR_ERRATUM_E1041 1061 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1062 default y 1063 help 1064 Falkor CPU may speculatively fetch instructions from an improper 1065 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1066 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1067 1068 If unsure, say Y. 1069 1070config NVIDIA_CARMEL_CNP_ERRATUM 1071 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1072 default y 1073 help 1074 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1075 invalidate shared TLB entries installed by a different core, as it would 1076 on standard ARM cores. 1077 1078 If unsure, say Y. 1079 1080config SOCIONEXT_SYNQUACER_PREITS 1081 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1082 default y 1083 help 1084 Socionext Synquacer SoCs implement a separate h/w block to generate 1085 MSI doorbell writes with non-zero values for the device ID. 1086 1087 If unsure, say Y. 1088 1089endmenu # "ARM errata workarounds via the alternatives framework" 1090 1091choice 1092 prompt "Page size" 1093 default ARM64_4K_PAGES 1094 help 1095 Page size (translation granule) configuration. 1096 1097config ARM64_4K_PAGES 1098 bool "4KB" 1099 help 1100 This feature enables 4KB pages support. 1101 1102config ARM64_16K_PAGES 1103 bool "16KB" 1104 help 1105 The system will use 16KB pages support. AArch32 emulation 1106 requires applications compiled with 16K (or a multiple of 16K) 1107 aligned segments. 1108 1109config ARM64_64K_PAGES 1110 bool "64KB" 1111 help 1112 This feature enables 64KB pages support (4KB by default) 1113 allowing only two levels of page tables and faster TLB 1114 look-up. AArch32 emulation requires applications compiled 1115 with 64K aligned segments. 1116 1117endchoice 1118 1119choice 1120 prompt "Virtual address space size" 1121 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1122 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1123 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1124 help 1125 Allows choosing one of multiple possible virtual address 1126 space sizes. The level of translation table is determined by 1127 a combination of page size and virtual address space size. 1128 1129config ARM64_VA_BITS_36 1130 bool "36-bit" if EXPERT 1131 depends on ARM64_16K_PAGES 1132 1133config ARM64_VA_BITS_39 1134 bool "39-bit" 1135 depends on ARM64_4K_PAGES 1136 1137config ARM64_VA_BITS_42 1138 bool "42-bit" 1139 depends on ARM64_64K_PAGES 1140 1141config ARM64_VA_BITS_47 1142 bool "47-bit" 1143 depends on ARM64_16K_PAGES 1144 1145config ARM64_VA_BITS_48 1146 bool "48-bit" 1147 1148config ARM64_VA_BITS_52 1149 bool "52-bit" 1150 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1151 help 1152 Enable 52-bit virtual addressing for userspace when explicitly 1153 requested via a hint to mmap(). The kernel will also use 52-bit 1154 virtual addresses for its own mappings (provided HW support for 1155 this feature is available, otherwise it reverts to 48-bit). 1156 1157 NOTE: Enabling 52-bit virtual addressing in conjunction with 1158 ARMv8.3 Pointer Authentication will result in the PAC being 1159 reduced from 7 bits to 3 bits, which may have a significant 1160 impact on its susceptibility to brute-force attacks. 1161 1162 If unsure, select 48-bit virtual addressing instead. 1163 1164endchoice 1165 1166config ARM64_FORCE_52BIT 1167 bool "Force 52-bit virtual addresses for userspace" 1168 depends on ARM64_VA_BITS_52 && EXPERT 1169 help 1170 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1171 to maintain compatibility with older software by providing 48-bit VAs 1172 unless a hint is supplied to mmap. 1173 1174 This configuration option disables the 48-bit compatibility logic, and 1175 forces all userspace addresses to be 52-bit on HW that supports it. One 1176 should only enable this configuration option for stress testing userspace 1177 memory management code. If unsure say N here. 1178 1179config ARM64_VA_BITS 1180 int 1181 default 36 if ARM64_VA_BITS_36 1182 default 39 if ARM64_VA_BITS_39 1183 default 42 if ARM64_VA_BITS_42 1184 default 47 if ARM64_VA_BITS_47 1185 default 48 if ARM64_VA_BITS_48 1186 default 52 if ARM64_VA_BITS_52 1187 1188choice 1189 prompt "Physical address space size" 1190 default ARM64_PA_BITS_48 1191 help 1192 Choose the maximum physical address range that the kernel will 1193 support. 1194 1195config ARM64_PA_BITS_48 1196 bool "48-bit" 1197 1198config ARM64_PA_BITS_52 1199 bool "52-bit (ARMv8.2)" 1200 depends on ARM64_64K_PAGES 1201 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1202 help 1203 Enable support for a 52-bit physical address space, introduced as 1204 part of the ARMv8.2-LPA extension. 1205 1206 With this enabled, the kernel will also continue to work on CPUs that 1207 do not support ARMv8.2-LPA, but with some added memory overhead (and 1208 minor performance overhead). 1209 1210endchoice 1211 1212config ARM64_PA_BITS 1213 int 1214 default 48 if ARM64_PA_BITS_48 1215 default 52 if ARM64_PA_BITS_52 1216 1217choice 1218 prompt "Endianness" 1219 default CPU_LITTLE_ENDIAN 1220 help 1221 Select the endianness of data accesses performed by the CPU. Userspace 1222 applications will need to be compiled and linked for the endianness 1223 that is selected here. 1224 1225config CPU_BIG_ENDIAN 1226 bool "Build big-endian kernel" 1227 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1228 help 1229 Say Y if you plan on running a kernel with a big-endian userspace. 1230 1231config CPU_LITTLE_ENDIAN 1232 bool "Build little-endian kernel" 1233 help 1234 Say Y if you plan on running a kernel with a little-endian userspace. 1235 This is usually the case for distributions targeting arm64. 1236 1237endchoice 1238 1239config SCHED_MC 1240 bool "Multi-core scheduler support" 1241 help 1242 Multi-core scheduler support improves the CPU scheduler's decision 1243 making when dealing with multi-core CPU chips at a cost of slightly 1244 increased overhead in some places. If unsure say N here. 1245 1246config SCHED_CLUSTER 1247 bool "Cluster scheduler support" 1248 help 1249 Cluster scheduler support improves the CPU scheduler's decision 1250 making when dealing with machines that have clusters of CPUs. 1251 Cluster usually means a couple of CPUs which are placed closely 1252 by sharing mid-level caches, last-level cache tags or internal 1253 busses. 1254 1255config SCHED_SMT 1256 bool "SMT scheduler support" 1257 help 1258 Improves the CPU scheduler's decision making when dealing with 1259 MultiThreading at a cost of slightly increased overhead in some 1260 places. If unsure say N here. 1261 1262config NR_CPUS 1263 int "Maximum number of CPUs (2-4096)" 1264 range 2 4096 1265 default "256" 1266 1267config HOTPLUG_CPU 1268 bool "Support for hot-pluggable CPUs" 1269 select GENERIC_IRQ_MIGRATION 1270 help 1271 Say Y here to experiment with turning CPUs off and on. CPUs 1272 can be controlled through /sys/devices/system/cpu. 1273 1274# Common NUMA Features 1275config NUMA 1276 bool "NUMA Memory Allocation and Scheduler Support" 1277 select GENERIC_ARCH_NUMA 1278 select ACPI_NUMA if ACPI 1279 select OF_NUMA 1280 select HAVE_SETUP_PER_CPU_AREA 1281 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1282 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1283 select USE_PERCPU_NUMA_NODE_ID 1284 help 1285 Enable NUMA (Non-Uniform Memory Access) support. 1286 1287 The kernel will try to allocate memory used by a CPU on the 1288 local memory of the CPU and add some more 1289 NUMA awareness to the kernel. 1290 1291config NODES_SHIFT 1292 int "Maximum NUMA Nodes (as a power of 2)" 1293 range 1 10 1294 default "4" 1295 depends on NUMA 1296 help 1297 Specify the maximum number of NUMA Nodes available on the target 1298 system. Increases memory reserved to accommodate various tables. 1299 1300source "kernel/Kconfig.hz" 1301 1302config ARCH_SPARSEMEM_ENABLE 1303 def_bool y 1304 select SPARSEMEM_VMEMMAP_ENABLE 1305 select SPARSEMEM_VMEMMAP 1306 1307config HW_PERF_EVENTS 1308 def_bool y 1309 depends on ARM_PMU 1310 1311# Supported by clang >= 7.0 or GCC >= 12.0.0 1312config CC_HAVE_SHADOW_CALL_STACK 1313 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1314 1315config PARAVIRT 1316 bool "Enable paravirtualization code" 1317 help 1318 This changes the kernel so it can modify itself when it is run 1319 under a hypervisor, potentially improving performance significantly 1320 over full virtualization. 1321 1322config PARAVIRT_TIME_ACCOUNTING 1323 bool "Paravirtual steal time accounting" 1324 select PARAVIRT 1325 help 1326 Select this option to enable fine granularity task steal time 1327 accounting. Time spent executing other tasks in parallel with 1328 the current vCPU is discounted from the vCPU power. To account for 1329 that, there can be a small performance impact. 1330 1331 If in doubt, say N here. 1332 1333config KEXEC 1334 depends on PM_SLEEP_SMP 1335 select KEXEC_CORE 1336 bool "kexec system call" 1337 help 1338 kexec is a system call that implements the ability to shutdown your 1339 current kernel, and to start another kernel. It is like a reboot 1340 but it is independent of the system firmware. And like a reboot 1341 you can start any kernel with it, not just Linux. 1342 1343config KEXEC_FILE 1344 bool "kexec file based system call" 1345 select KEXEC_CORE 1346 select HAVE_IMA_KEXEC if IMA 1347 help 1348 This is new version of kexec system call. This system call is 1349 file based and takes file descriptors as system call argument 1350 for kernel and initramfs as opposed to list of segments as 1351 accepted by previous system call. 1352 1353config KEXEC_SIG 1354 bool "Verify kernel signature during kexec_file_load() syscall" 1355 depends on KEXEC_FILE 1356 help 1357 Select this option to verify a signature with loaded kernel 1358 image. If configured, any attempt of loading a image without 1359 valid signature will fail. 1360 1361 In addition to that option, you need to enable signature 1362 verification for the corresponding kernel image type being 1363 loaded in order for this to work. 1364 1365config KEXEC_IMAGE_VERIFY_SIG 1366 bool "Enable Image signature verification support" 1367 default y 1368 depends on KEXEC_SIG 1369 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1370 help 1371 Enable Image signature verification support. 1372 1373comment "Support for PE file signature verification disabled" 1374 depends on KEXEC_SIG 1375 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1376 1377config CRASH_DUMP 1378 bool "Build kdump crash kernel" 1379 help 1380 Generate crash dump after being started by kexec. This should 1381 be normally only set in special crash dump kernels which are 1382 loaded in the main kernel with kexec-tools into a specially 1383 reserved region and then later executed after a crash by 1384 kdump/kexec. 1385 1386 For more details see Documentation/admin-guide/kdump/kdump.rst 1387 1388config TRANS_TABLE 1389 def_bool y 1390 depends on HIBERNATION || KEXEC_CORE 1391 1392config XEN_DOM0 1393 def_bool y 1394 depends on XEN 1395 1396config XEN 1397 bool "Xen guest support on ARM64" 1398 depends on ARM64 && OF 1399 select SWIOTLB_XEN 1400 select PARAVIRT 1401 help 1402 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1403 1404config FORCE_MAX_ZONEORDER 1405 int 1406 default "14" if ARM64_64K_PAGES 1407 default "12" if ARM64_16K_PAGES 1408 default "11" 1409 help 1410 The kernel memory allocator divides physically contiguous memory 1411 blocks into "zones", where each zone is a power of two number of 1412 pages. This option selects the largest power of two that the kernel 1413 keeps in the memory allocator. If you need to allocate very large 1414 blocks of physically contiguous memory, then you may need to 1415 increase this value. 1416 1417 This config option is actually maximum order plus one. For example, 1418 a value of 11 means that the largest free memory block is 2^10 pages. 1419 1420 We make sure that we can allocate upto a HugePage size for each configuration. 1421 Hence we have : 1422 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1423 1424 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1425 4M allocations matching the default size used by generic code. 1426 1427config UNMAP_KERNEL_AT_EL0 1428 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1429 default y 1430 help 1431 Speculation attacks against some high-performance processors can 1432 be used to bypass MMU permission checks and leak kernel data to 1433 userspace. This can be defended against by unmapping the kernel 1434 when running in userspace, mapping it back in on exception entry 1435 via a trampoline page in the vector table. 1436 1437 If unsure, say Y. 1438 1439config MITIGATE_SPECTRE_BRANCH_HISTORY 1440 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1441 default y 1442 help 1443 Speculation attacks against some high-performance processors can 1444 make use of branch history to influence future speculation. 1445 When taking an exception from user-space, a sequence of branches 1446 or a firmware call overwrites the branch history. 1447 1448config RODATA_FULL_DEFAULT_ENABLED 1449 bool "Apply r/o permissions of VM areas also to their linear aliases" 1450 default y 1451 help 1452 Apply read-only attributes of VM areas to the linear alias of 1453 the backing pages as well. This prevents code or read-only data 1454 from being modified (inadvertently or intentionally) via another 1455 mapping of the same memory page. This additional enhancement can 1456 be turned off at runtime by passing rodata=[off|on] (and turned on 1457 with rodata=full if this option is set to 'n') 1458 1459 This requires the linear region to be mapped down to pages, 1460 which may adversely affect performance in some cases. 1461 1462config ARM64_SW_TTBR0_PAN 1463 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1464 help 1465 Enabling this option prevents the kernel from accessing 1466 user-space memory directly by pointing TTBR0_EL1 to a reserved 1467 zeroed area and reserved ASID. The user access routines 1468 restore the valid TTBR0_EL1 temporarily. 1469 1470config ARM64_TAGGED_ADDR_ABI 1471 bool "Enable the tagged user addresses syscall ABI" 1472 default y 1473 help 1474 When this option is enabled, user applications can opt in to a 1475 relaxed ABI via prctl() allowing tagged addresses to be passed 1476 to system calls as pointer arguments. For details, see 1477 Documentation/arm64/tagged-address-abi.rst. 1478 1479menuconfig COMPAT 1480 bool "Kernel support for 32-bit EL0" 1481 depends on ARM64_4K_PAGES || EXPERT 1482 select HAVE_UID16 1483 select OLD_SIGSUSPEND3 1484 select COMPAT_OLD_SIGACTION 1485 help 1486 This option enables support for a 32-bit EL0 running under a 64-bit 1487 kernel at EL1. AArch32-specific components such as system calls, 1488 the user helper functions, VFP support and the ptrace interface are 1489 handled appropriately by the kernel. 1490 1491 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1492 that you will only be able to execute AArch32 binaries that were compiled 1493 with page size aligned segments. 1494 1495 If you want to execute 32-bit userspace applications, say Y. 1496 1497if COMPAT 1498 1499config KUSER_HELPERS 1500 bool "Enable kuser helpers page for 32-bit applications" 1501 default y 1502 help 1503 Warning: disabling this option may break 32-bit user programs. 1504 1505 Provide kuser helpers to compat tasks. The kernel provides 1506 helper code to userspace in read only form at a fixed location 1507 to allow userspace to be independent of the CPU type fitted to 1508 the system. This permits binaries to be run on ARMv4 through 1509 to ARMv8 without modification. 1510 1511 See Documentation/arm/kernel_user_helpers.rst for details. 1512 1513 However, the fixed address nature of these helpers can be used 1514 by ROP (return orientated programming) authors when creating 1515 exploits. 1516 1517 If all of the binaries and libraries which run on your platform 1518 are built specifically for your platform, and make no use of 1519 these helpers, then you can turn this option off to hinder 1520 such exploits. However, in that case, if a binary or library 1521 relying on those helpers is run, it will not function correctly. 1522 1523 Say N here only if you are absolutely certain that you do not 1524 need these helpers; otherwise, the safe option is to say Y. 1525 1526config COMPAT_VDSO 1527 bool "Enable vDSO for 32-bit applications" 1528 depends on !CPU_BIG_ENDIAN 1529 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1530 select GENERIC_COMPAT_VDSO 1531 default y 1532 help 1533 Place in the process address space of 32-bit applications an 1534 ELF shared object providing fast implementations of gettimeofday 1535 and clock_gettime. 1536 1537 You must have a 32-bit build of glibc 2.22 or later for programs 1538 to seamlessly take advantage of this. 1539 1540config THUMB2_COMPAT_VDSO 1541 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1542 depends on COMPAT_VDSO 1543 default y 1544 help 1545 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1546 otherwise with '-marm'. 1547 1548menuconfig ARMV8_DEPRECATED 1549 bool "Emulate deprecated/obsolete ARMv8 instructions" 1550 depends on SYSCTL 1551 help 1552 Legacy software support may require certain instructions 1553 that have been deprecated or obsoleted in the architecture. 1554 1555 Enable this config to enable selective emulation of these 1556 features. 1557 1558 If unsure, say Y 1559 1560if ARMV8_DEPRECATED 1561 1562config SWP_EMULATION 1563 bool "Emulate SWP/SWPB instructions" 1564 help 1565 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1566 they are always undefined. Say Y here to enable software 1567 emulation of these instructions for userspace using LDXR/STXR. 1568 This feature can be controlled at runtime with the abi.swp 1569 sysctl which is disabled by default. 1570 1571 In some older versions of glibc [<=2.8] SWP is used during futex 1572 trylock() operations with the assumption that the code will not 1573 be preempted. This invalid assumption may be more likely to fail 1574 with SWP emulation enabled, leading to deadlock of the user 1575 application. 1576 1577 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1578 on an external transaction monitoring block called a global 1579 monitor to maintain update atomicity. If your system does not 1580 implement a global monitor, this option can cause programs that 1581 perform SWP operations to uncached memory to deadlock. 1582 1583 If unsure, say Y 1584 1585config CP15_BARRIER_EMULATION 1586 bool "Emulate CP15 Barrier instructions" 1587 help 1588 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1589 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1590 strongly recommended to use the ISB, DSB, and DMB 1591 instructions instead. 1592 1593 Say Y here to enable software emulation of these 1594 instructions for AArch32 userspace code. When this option is 1595 enabled, CP15 barrier usage is traced which can help 1596 identify software that needs updating. This feature can be 1597 controlled at runtime with the abi.cp15_barrier sysctl. 1598 1599 If unsure, say Y 1600 1601config SETEND_EMULATION 1602 bool "Emulate SETEND instruction" 1603 help 1604 The SETEND instruction alters the data-endianness of the 1605 AArch32 EL0, and is deprecated in ARMv8. 1606 1607 Say Y here to enable software emulation of the instruction 1608 for AArch32 userspace code. This feature can be controlled 1609 at runtime with the abi.setend sysctl. 1610 1611 Note: All the cpus on the system must have mixed endian support at EL0 1612 for this feature to be enabled. If a new CPU - which doesn't support mixed 1613 endian - is hotplugged in after this feature has been enabled, there could 1614 be unexpected results in the applications. 1615 1616 If unsure, say Y 1617endif # ARMV8_DEPRECATED 1618 1619endif # COMPAT 1620 1621menu "ARMv8.1 architectural features" 1622 1623config ARM64_HW_AFDBM 1624 bool "Support for hardware updates of the Access and Dirty page flags" 1625 default y 1626 help 1627 The ARMv8.1 architecture extensions introduce support for 1628 hardware updates of the access and dirty information in page 1629 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1630 capable processors, accesses to pages with PTE_AF cleared will 1631 set this bit instead of raising an access flag fault. 1632 Similarly, writes to read-only pages with the DBM bit set will 1633 clear the read-only bit (AP[2]) instead of raising a 1634 permission fault. 1635 1636 Kernels built with this configuration option enabled continue 1637 to work on pre-ARMv8.1 hardware and the performance impact is 1638 minimal. If unsure, say Y. 1639 1640config ARM64_PAN 1641 bool "Enable support for Privileged Access Never (PAN)" 1642 default y 1643 help 1644 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1645 prevents the kernel or hypervisor from accessing user-space (EL0) 1646 memory directly. 1647 1648 Choosing this option will cause any unprotected (not using 1649 copy_to_user et al) memory access to fail with a permission fault. 1650 1651 The feature is detected at runtime, and will remain as a 'nop' 1652 instruction if the cpu does not implement the feature. 1653 1654config AS_HAS_LDAPR 1655 def_bool $(as-instr,.arch_extension rcpc) 1656 1657config AS_HAS_LSE_ATOMICS 1658 def_bool $(as-instr,.arch_extension lse) 1659 1660config ARM64_LSE_ATOMICS 1661 bool 1662 default ARM64_USE_LSE_ATOMICS 1663 depends on AS_HAS_LSE_ATOMICS 1664 1665config ARM64_USE_LSE_ATOMICS 1666 bool "Atomic instructions" 1667 depends on JUMP_LABEL 1668 default y 1669 help 1670 As part of the Large System Extensions, ARMv8.1 introduces new 1671 atomic instructions that are designed specifically to scale in 1672 very large systems. 1673 1674 Say Y here to make use of these instructions for the in-kernel 1675 atomic routines. This incurs a small overhead on CPUs that do 1676 not support these instructions and requires the kernel to be 1677 built with binutils >= 2.25 in order for the new instructions 1678 to be used. 1679 1680endmenu # "ARMv8.1 architectural features" 1681 1682menu "ARMv8.2 architectural features" 1683 1684config AS_HAS_ARMV8_2 1685 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1686 1687config AS_HAS_SHA3 1688 def_bool $(as-instr,.arch armv8.2-a+sha3) 1689 1690config ARM64_PMEM 1691 bool "Enable support for persistent memory" 1692 select ARCH_HAS_PMEM_API 1693 select ARCH_HAS_UACCESS_FLUSHCACHE 1694 help 1695 Say Y to enable support for the persistent memory API based on the 1696 ARMv8.2 DCPoP feature. 1697 1698 The feature is detected at runtime, and the kernel will use DC CVAC 1699 operations if DC CVAP is not supported (following the behaviour of 1700 DC CVAP itself if the system does not define a point of persistence). 1701 1702config ARM64_RAS_EXTN 1703 bool "Enable support for RAS CPU Extensions" 1704 default y 1705 help 1706 CPUs that support the Reliability, Availability and Serviceability 1707 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1708 errors, classify them and report them to software. 1709 1710 On CPUs with these extensions system software can use additional 1711 barriers to determine if faults are pending and read the 1712 classification from a new set of registers. 1713 1714 Selecting this feature will allow the kernel to use these barriers 1715 and access the new registers if the system supports the extension. 1716 Platform RAS features may additionally depend on firmware support. 1717 1718config ARM64_CNP 1719 bool "Enable support for Common Not Private (CNP) translations" 1720 default y 1721 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1722 help 1723 Common Not Private (CNP) allows translation table entries to 1724 be shared between different PEs in the same inner shareable 1725 domain, so the hardware can use this fact to optimise the 1726 caching of such entries in the TLB. 1727 1728 Selecting this option allows the CNP feature to be detected 1729 at runtime, and does not affect PEs that do not implement 1730 this feature. 1731 1732endmenu # "ARMv8.2 architectural features" 1733 1734menu "ARMv8.3 architectural features" 1735 1736config ARM64_PTR_AUTH 1737 bool "Enable support for pointer authentication" 1738 default y 1739 help 1740 Pointer authentication (part of the ARMv8.3 Extensions) provides 1741 instructions for signing and authenticating pointers against secret 1742 keys, which can be used to mitigate Return Oriented Programming (ROP) 1743 and other attacks. 1744 1745 This option enables these instructions at EL0 (i.e. for userspace). 1746 Choosing this option will cause the kernel to initialise secret keys 1747 for each process at exec() time, with these keys being 1748 context-switched along with the process. 1749 1750 The feature is detected at runtime. If the feature is not present in 1751 hardware it will not be advertised to userspace/KVM guest nor will it 1752 be enabled. 1753 1754 If the feature is present on the boot CPU but not on a late CPU, then 1755 the late CPU will be parked. Also, if the boot CPU does not have 1756 address auth and the late CPU has then the late CPU will still boot 1757 but with the feature disabled. On such a system, this option should 1758 not be selected. 1759 1760config ARM64_PTR_AUTH_KERNEL 1761 bool "Use pointer authentication for kernel" 1762 default y 1763 depends on ARM64_PTR_AUTH 1764 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1765 # Modern compilers insert a .note.gnu.property section note for PAC 1766 # which is only understood by binutils starting with version 2.33.1. 1767 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1768 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1769 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1770 help 1771 If the compiler supports the -mbranch-protection or 1772 -msign-return-address flag (e.g. GCC 7 or later), then this option 1773 will cause the kernel itself to be compiled with return address 1774 protection. In this case, and if the target hardware is known to 1775 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1776 disabled with minimal loss of protection. 1777 1778 This feature works with FUNCTION_GRAPH_TRACER option only if 1779 DYNAMIC_FTRACE_WITH_REGS is enabled. 1780 1781config CC_HAS_BRANCH_PROT_PAC_RET 1782 # GCC 9 or later, clang 8 or later 1783 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1784 1785config CC_HAS_SIGN_RETURN_ADDRESS 1786 # GCC 7, 8 1787 def_bool $(cc-option,-msign-return-address=all) 1788 1789config AS_HAS_PAC 1790 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1791 1792config AS_HAS_CFI_NEGATE_RA_STATE 1793 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1794 1795endmenu # "ARMv8.3 architectural features" 1796 1797menu "ARMv8.4 architectural features" 1798 1799config ARM64_AMU_EXTN 1800 bool "Enable support for the Activity Monitors Unit CPU extension" 1801 default y 1802 help 1803 The activity monitors extension is an optional extension introduced 1804 by the ARMv8.4 CPU architecture. This enables support for version 1 1805 of the activity monitors architecture, AMUv1. 1806 1807 To enable the use of this extension on CPUs that implement it, say Y. 1808 1809 Note that for architectural reasons, firmware _must_ implement AMU 1810 support when running on CPUs that present the activity monitors 1811 extension. The required support is present in: 1812 * Version 1.5 and later of the ARM Trusted Firmware 1813 1814 For kernels that have this configuration enabled but boot with broken 1815 firmware, you may need to say N here until the firmware is fixed. 1816 Otherwise you may experience firmware panics or lockups when 1817 accessing the counter registers. Even if you are not observing these 1818 symptoms, the values returned by the register reads might not 1819 correctly reflect reality. Most commonly, the value read will be 0, 1820 indicating that the counter is not enabled. 1821 1822config AS_HAS_ARMV8_4 1823 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1824 1825config ARM64_TLB_RANGE 1826 bool "Enable support for tlbi range feature" 1827 default y 1828 depends on AS_HAS_ARMV8_4 1829 help 1830 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1831 range of input addresses. 1832 1833 The feature introduces new assembly instructions, and they were 1834 support when binutils >= 2.30. 1835 1836endmenu # "ARMv8.4 architectural features" 1837 1838menu "ARMv8.5 architectural features" 1839 1840config AS_HAS_ARMV8_5 1841 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1842 1843config ARM64_BTI 1844 bool "Branch Target Identification support" 1845 default y 1846 help 1847 Branch Target Identification (part of the ARMv8.5 Extensions) 1848 provides a mechanism to limit the set of locations to which computed 1849 branch instructions such as BR or BLR can jump. 1850 1851 To make use of BTI on CPUs that support it, say Y. 1852 1853 BTI is intended to provide complementary protection to other control 1854 flow integrity protection mechanisms, such as the Pointer 1855 authentication mechanism provided as part of the ARMv8.3 Extensions. 1856 For this reason, it does not make sense to enable this option without 1857 also enabling support for pointer authentication. Thus, when 1858 enabling this option you should also select ARM64_PTR_AUTH=y. 1859 1860 Userspace binaries must also be specifically compiled to make use of 1861 this mechanism. If you say N here or the hardware does not support 1862 BTI, such binaries can still run, but you get no additional 1863 enforcement of branch destinations. 1864 1865config ARM64_BTI_KERNEL 1866 bool "Use Branch Target Identification for kernel" 1867 default y 1868 depends on ARM64_BTI 1869 depends on ARM64_PTR_AUTH_KERNEL 1870 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1871 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1872 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1873 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1874 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1875 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1876 help 1877 Build the kernel with Branch Target Identification annotations 1878 and enable enforcement of this for kernel code. When this option 1879 is enabled and the system supports BTI all kernel code including 1880 modular code must have BTI enabled. 1881 1882config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1883 # GCC 9 or later, clang 8 or later 1884 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1885 1886config ARM64_E0PD 1887 bool "Enable support for E0PD" 1888 default y 1889 help 1890 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1891 that EL0 accesses made via TTBR1 always fault in constant time, 1892 providing similar benefits to KASLR as those provided by KPTI, but 1893 with lower overhead and without disrupting legitimate access to 1894 kernel memory such as SPE. 1895 1896 This option enables E0PD for TTBR1 where available. 1897 1898config ARM64_AS_HAS_MTE 1899 # Initial support for MTE went in binutils 2.32.0, checked with 1900 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1901 # as a late addition to the final architecture spec (LDGM/STGM) 1902 # is only supported in the newer 2.32.x and 2.33 binutils 1903 # versions, hence the extra "stgm" instruction check below. 1904 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1905 1906config ARM64_MTE 1907 bool "Memory Tagging Extension support" 1908 default y 1909 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1910 depends on AS_HAS_ARMV8_5 1911 depends on AS_HAS_LSE_ATOMICS 1912 # Required for tag checking in the uaccess routines 1913 depends on ARM64_PAN 1914 select ARCH_HAS_SUBPAGE_FAULTS 1915 select ARCH_USES_HIGH_VMA_FLAGS 1916 help 1917 Memory Tagging (part of the ARMv8.5 Extensions) provides 1918 architectural support for run-time, always-on detection of 1919 various classes of memory error to aid with software debugging 1920 to eliminate vulnerabilities arising from memory-unsafe 1921 languages. 1922 1923 This option enables the support for the Memory Tagging 1924 Extension at EL0 (i.e. for userspace). 1925 1926 Selecting this option allows the feature to be detected at 1927 runtime. Any secondary CPU not implementing this feature will 1928 not be allowed a late bring-up. 1929 1930 Userspace binaries that want to use this feature must 1931 explicitly opt in. The mechanism for the userspace is 1932 described in: 1933 1934 Documentation/arm64/memory-tagging-extension.rst. 1935 1936endmenu # "ARMv8.5 architectural features" 1937 1938menu "ARMv8.7 architectural features" 1939 1940config ARM64_EPAN 1941 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 1942 default y 1943 depends on ARM64_PAN 1944 help 1945 Enhanced Privileged Access Never (EPAN) allows Privileged 1946 Access Never to be used with Execute-only mappings. 1947 1948 The feature is detected at runtime, and will remain disabled 1949 if the cpu does not implement the feature. 1950endmenu # "ARMv8.7 architectural features" 1951 1952config ARM64_SVE 1953 bool "ARM Scalable Vector Extension support" 1954 default y 1955 help 1956 The Scalable Vector Extension (SVE) is an extension to the AArch64 1957 execution state which complements and extends the SIMD functionality 1958 of the base architecture to support much larger vectors and to enable 1959 additional vectorisation opportunities. 1960 1961 To enable use of this extension on CPUs that implement it, say Y. 1962 1963 On CPUs that support the SVE2 extensions, this option will enable 1964 those too. 1965 1966 Note that for architectural reasons, firmware _must_ implement SVE 1967 support when running on SVE capable hardware. The required support 1968 is present in: 1969 1970 * version 1.5 and later of the ARM Trusted Firmware 1971 * the AArch64 boot wrapper since commit 5e1261e08abf 1972 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1973 1974 For other firmware implementations, consult the firmware documentation 1975 or vendor. 1976 1977 If you need the kernel to boot on SVE-capable hardware with broken 1978 firmware, you may need to say N here until you get your firmware 1979 fixed. Otherwise, you may experience firmware panics or lockups when 1980 booting the kernel. If unsure and you are not observing these 1981 symptoms, you should assume that it is safe to say Y. 1982 1983config ARM64_SME 1984 bool "ARM Scalable Matrix Extension support" 1985 default y 1986 depends on ARM64_SVE 1987 help 1988 The Scalable Matrix Extension (SME) is an extension to the AArch64 1989 execution state which utilises a substantial subset of the SVE 1990 instruction set, together with the addition of new architectural 1991 register state capable of holding two dimensional matrix tiles to 1992 enable various matrix operations. 1993 1994config ARM64_MODULE_PLTS 1995 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1996 depends on MODULES 1997 select HAVE_MOD_ARCH_SPECIFIC 1998 help 1999 Allocate PLTs when loading modules so that jumps and calls whose 2000 targets are too far away for their relative offsets to be encoded 2001 in the instructions themselves can be bounced via veneers in the 2002 module's PLT. This allows modules to be allocated in the generic 2003 vmalloc area after the dedicated module memory area has been 2004 exhausted. 2005 2006 When running with address space randomization (KASLR), the module 2007 region itself may be too far away for ordinary relative jumps and 2008 calls, and so in that case, module PLTs are required and cannot be 2009 disabled. 2010 2011 Specific errata workaround(s) might also force module PLTs to be 2012 enabled (ARM64_ERRATUM_843419). 2013 2014config ARM64_PSEUDO_NMI 2015 bool "Support for NMI-like interrupts" 2016 select ARM_GIC_V3 2017 help 2018 Adds support for mimicking Non-Maskable Interrupts through the use of 2019 GIC interrupt priority. This support requires version 3 or later of 2020 ARM GIC. 2021 2022 This high priority configuration for interrupts needs to be 2023 explicitly enabled by setting the kernel parameter 2024 "irqchip.gicv3_pseudo_nmi" to 1. 2025 2026 If unsure, say N 2027 2028if ARM64_PSEUDO_NMI 2029config ARM64_DEBUG_PRIORITY_MASKING 2030 bool "Debug interrupt priority masking" 2031 help 2032 This adds runtime checks to functions enabling/disabling 2033 interrupts when using priority masking. The additional checks verify 2034 the validity of ICC_PMR_EL1 when calling concerned functions. 2035 2036 If unsure, say N 2037endif # ARM64_PSEUDO_NMI 2038 2039config RELOCATABLE 2040 bool "Build a relocatable kernel image" if EXPERT 2041 select ARCH_HAS_RELR 2042 default y 2043 help 2044 This builds the kernel as a Position Independent Executable (PIE), 2045 which retains all relocation metadata required to relocate the 2046 kernel binary at runtime to a different virtual address than the 2047 address it was linked at. 2048 Since AArch64 uses the RELA relocation format, this requires a 2049 relocation pass at runtime even if the kernel is loaded at the 2050 same address it was linked at. 2051 2052config RANDOMIZE_BASE 2053 bool "Randomize the address of the kernel image" 2054 select ARM64_MODULE_PLTS if MODULES 2055 select RELOCATABLE 2056 help 2057 Randomizes the virtual address at which the kernel image is 2058 loaded, as a security feature that deters exploit attempts 2059 relying on knowledge of the location of kernel internals. 2060 2061 It is the bootloader's job to provide entropy, by passing a 2062 random u64 value in /chosen/kaslr-seed at kernel entry. 2063 2064 When booting via the UEFI stub, it will invoke the firmware's 2065 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2066 to the kernel proper. In addition, it will randomise the physical 2067 location of the kernel Image as well. 2068 2069 If unsure, say N. 2070 2071config RANDOMIZE_MODULE_REGION_FULL 2072 bool "Randomize the module region over a 2 GB range" 2073 depends on RANDOMIZE_BASE 2074 default y 2075 help 2076 Randomizes the location of the module region inside a 2 GB window 2077 covering the core kernel. This way, it is less likely for modules 2078 to leak information about the location of core kernel data structures 2079 but it does imply that function calls between modules and the core 2080 kernel will need to be resolved via veneers in the module PLT. 2081 2082 When this option is not set, the module region will be randomized over 2083 a limited range that contains the [_stext, _etext] interval of the 2084 core kernel, so branch relocations are almost always in range unless 2085 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2086 particular case of region exhaustion, modules might be able to fall 2087 back to a larger 2GB area. 2088 2089config CC_HAVE_STACKPROTECTOR_SYSREG 2090 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2091 2092config STACKPROTECTOR_PER_TASK 2093 def_bool y 2094 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2095 2096# The GPIO number here must be sorted by descending number. In case of 2097# a multiplatform kernel, we just want the highest value required by the 2098# selected platforms. 2099config ARCH_NR_GPIO 2100 int 2101 default 2048 if ARCH_APPLE 2102 default 0 2103 help 2104 Maximum number of GPIOs in the system. 2105 2106 If unsure, leave the default value. 2107 2108endmenu # "Kernel Features" 2109 2110menu "Boot options" 2111 2112config ARM64_ACPI_PARKING_PROTOCOL 2113 bool "Enable support for the ARM64 ACPI parking protocol" 2114 depends on ACPI 2115 help 2116 Enable support for the ARM64 ACPI parking protocol. If disabled 2117 the kernel will not allow booting through the ARM64 ACPI parking 2118 protocol even if the corresponding data is present in the ACPI 2119 MADT table. 2120 2121config CMDLINE 2122 string "Default kernel command string" 2123 default "" 2124 help 2125 Provide a set of default command-line options at build time by 2126 entering them here. As a minimum, you should specify the the 2127 root device (e.g. root=/dev/nfs). 2128 2129choice 2130 prompt "Kernel command line type" if CMDLINE != "" 2131 default CMDLINE_FROM_BOOTLOADER 2132 help 2133 Choose how the kernel will handle the provided default kernel 2134 command line string. 2135 2136config CMDLINE_FROM_BOOTLOADER 2137 bool "Use bootloader kernel arguments if available" 2138 help 2139 Uses the command-line options passed by the boot loader. If 2140 the boot loader doesn't provide any, the default kernel command 2141 string provided in CMDLINE will be used. 2142 2143config CMDLINE_FORCE 2144 bool "Always use the default kernel command string" 2145 help 2146 Always use the default kernel command string, even if the boot 2147 loader passes other arguments to the kernel. 2148 This is useful if you cannot or don't want to change the 2149 command-line options your boot loader passes to the kernel. 2150 2151endchoice 2152 2153config EFI_STUB 2154 bool 2155 2156config EFI 2157 bool "UEFI runtime support" 2158 depends on OF && !CPU_BIG_ENDIAN 2159 depends on KERNEL_MODE_NEON 2160 select ARCH_SUPPORTS_ACPI 2161 select LIBFDT 2162 select UCS2_STRING 2163 select EFI_PARAMS_FROM_FDT 2164 select EFI_RUNTIME_WRAPPERS 2165 select EFI_STUB 2166 select EFI_GENERIC_STUB 2167 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2168 default y 2169 help 2170 This option provides support for runtime services provided 2171 by UEFI firmware (such as non-volatile variables, realtime 2172 clock, and platform reset). A UEFI stub is also provided to 2173 allow the kernel to be booted as an EFI application. This 2174 is only useful on systems that have UEFI firmware. 2175 2176config DMI 2177 bool "Enable support for SMBIOS (DMI) tables" 2178 depends on EFI 2179 default y 2180 help 2181 This enables SMBIOS/DMI feature for systems. 2182 2183 This option is only useful on systems that have UEFI firmware. 2184 However, even with this option, the resultant kernel should 2185 continue to boot on existing non-UEFI platforms. 2186 2187endmenu # "Boot options" 2188 2189menu "Power management options" 2190 2191source "kernel/power/Kconfig" 2192 2193config ARCH_HIBERNATION_POSSIBLE 2194 def_bool y 2195 depends on CPU_PM 2196 2197config ARCH_HIBERNATION_HEADER 2198 def_bool y 2199 depends on HIBERNATION 2200 2201config ARCH_SUSPEND_POSSIBLE 2202 def_bool y 2203 2204endmenu # "Power management options" 2205 2206menu "CPU Power Management" 2207 2208source "drivers/cpuidle/Kconfig" 2209 2210source "drivers/cpufreq/Kconfig" 2211 2212endmenu # "CPU Power Management" 2213 2214source "drivers/acpi/Kconfig" 2215 2216source "arch/arm64/kvm/Kconfig" 2217 2218if CRYPTO 2219source "arch/arm64/crypto/Kconfig" 2220endif # CRYPTO 2221