1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_IORT if ACPI 9 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 10 select ACPI_MCFG if (ACPI && PCI) 11 select ACPI_SPCR_TABLE if ACPI 12 select ACPI_PPTT if ACPI 13 select ARCH_HAS_DEBUG_WX 14 select ARCH_BINFMT_ELF_EXTRA_PHDRS 15 select ARCH_BINFMT_ELF_STATE 16 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CURRENT_STACK_POINTER 24 select ARCH_HAS_DEBUG_VIRTUAL 25 select ARCH_HAS_DEBUG_VM_PGTABLE 26 select ARCH_HAS_DMA_PREP_COHERENT 27 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 28 select ARCH_HAS_FAST_MULTIPLIER 29 select ARCH_HAS_FORTIFY_SOURCE 30 select ARCH_HAS_GCOV_PROFILE_ALL 31 select ARCH_HAS_GIGANTIC_PAGE 32 select ARCH_HAS_KCOV 33 select ARCH_HAS_KEEPINITRD 34 select ARCH_HAS_MEMBARRIER_SYNC_CORE 35 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 36 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 37 select ARCH_HAS_PTE_DEVMAP 38 select ARCH_HAS_PTE_SPECIAL 39 select ARCH_HAS_SETUP_DMA_OPS 40 select ARCH_HAS_SET_DIRECT_MAP 41 select ARCH_HAS_SET_MEMORY 42 select ARCH_STACKWALK 43 select ARCH_HAS_STRICT_KERNEL_RWX 44 select ARCH_HAS_STRICT_MODULE_RWX 45 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 46 select ARCH_HAS_SYNC_DMA_FOR_CPU 47 select ARCH_HAS_SYSCALL_WRAPPER 48 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 49 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 50 select ARCH_HAS_ZONE_DMA_SET if EXPERT 51 select ARCH_HAVE_ELF_PROT 52 select ARCH_HAVE_NMI_SAFE_CMPXCHG 53 select ARCH_HAVE_TRACE_MMIO_ACCESS 54 select ARCH_INLINE_READ_LOCK if !PREEMPTION 55 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 56 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 57 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 58 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 59 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 60 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 61 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 62 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 63 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 64 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 65 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 66 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 67 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 68 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 69 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 70 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 71 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 72 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 73 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_KEEP_MEMBLOCK 81 select ARCH_USE_CMPXCHG_LOCKREF 82 select ARCH_USE_GNU_PROPERTY 83 select ARCH_USE_MEMTEST 84 select ARCH_USE_QUEUED_RWLOCKS 85 select ARCH_USE_QUEUED_SPINLOCKS 86 select ARCH_USE_SYM_ANNOTATIONS 87 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 88 select ARCH_SUPPORTS_HUGETLBFS 89 select ARCH_SUPPORTS_MEMORY_FAILURE 90 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 91 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 92 select ARCH_SUPPORTS_LTO_CLANG_THIN 93 select ARCH_SUPPORTS_CFI_CLANG 94 select ARCH_SUPPORTS_ATOMIC_RMW 95 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 96 select ARCH_SUPPORTS_NUMA_BALANCING 97 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 98 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 99 select ARCH_WANT_DEFAULT_BPF_JIT 100 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 101 select ARCH_WANT_FRAME_POINTERS 102 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 103 select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP 104 select ARCH_WANT_LD_ORPHAN_WARN 105 select ARCH_WANTS_NO_INSTR 106 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 107 select ARCH_HAS_UBSAN_SANITIZE_ALL 108 select ARM_AMBA 109 select ARM_ARCH_TIMER 110 select ARM_GIC 111 select AUDIT_ARCH_COMPAT_GENERIC 112 select ARM_GIC_V2M if PCI 113 select ARM_GIC_V3 114 select ARM_GIC_V3_ITS if PCI 115 select ARM_PSCI_FW 116 select BUILDTIME_TABLE_SORT 117 select CLONE_BACKWARDS 118 select COMMON_CLK 119 select CPU_PM if (SUSPEND || CPU_IDLE) 120 select CRC32 121 select DCACHE_WORD_ACCESS 122 select DYNAMIC_FTRACE if FUNCTION_TRACER 123 select DMA_DIRECT_REMAP 124 select EDAC_SUPPORT 125 select FRAME_POINTER 126 select FUNCTION_ALIGNMENT_4B 127 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 128 select GENERIC_ALLOCATOR 129 select GENERIC_ARCH_TOPOLOGY 130 select GENERIC_CLOCKEVENTS_BROADCAST 131 select GENERIC_CPU_AUTOPROBE 132 select GENERIC_CPU_VULNERABILITIES 133 select GENERIC_EARLY_IOREMAP 134 select GENERIC_IDLE_POLL_SETUP 135 select GENERIC_IOREMAP 136 select GENERIC_IRQ_IPI 137 select GENERIC_IRQ_PROBE 138 select GENERIC_IRQ_SHOW 139 select GENERIC_IRQ_SHOW_LEVEL 140 select GENERIC_LIB_DEVMEM_IS_ALLOWED 141 select GENERIC_PCI_IOMAP 142 select GENERIC_PTDUMP 143 select GENERIC_SCHED_CLOCK 144 select GENERIC_SMP_IDLE_THREAD 145 select GENERIC_TIME_VSYSCALL 146 select GENERIC_GETTIMEOFDAY 147 select GENERIC_VDSO_TIME_NS 148 select HARDIRQS_SW_RESEND 149 select HAVE_MOVE_PMD 150 select HAVE_MOVE_PUD 151 select HAVE_PCI 152 select HAVE_ACPI_APEI if (ACPI && EFI) 153 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 154 select HAVE_ARCH_AUDITSYSCALL 155 select HAVE_ARCH_BITREVERSE 156 select HAVE_ARCH_COMPILER_H 157 select HAVE_ARCH_HUGE_VMALLOC 158 select HAVE_ARCH_HUGE_VMAP 159 select HAVE_ARCH_JUMP_LABEL 160 select HAVE_ARCH_JUMP_LABEL_RELATIVE 161 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 162 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 163 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 164 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 165 # Some instrumentation may be unsound, hence EXPERT 166 select HAVE_ARCH_KCSAN if EXPERT 167 select HAVE_ARCH_KFENCE 168 select HAVE_ARCH_KGDB 169 select HAVE_ARCH_MMAP_RND_BITS 170 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 171 select HAVE_ARCH_PREL32_RELOCATIONS 172 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 173 select HAVE_ARCH_SECCOMP_FILTER 174 select HAVE_ARCH_STACKLEAK 175 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 176 select HAVE_ARCH_TRACEHOOK 177 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 178 select HAVE_ARCH_VMAP_STACK 179 select HAVE_ARM_SMCCC 180 select HAVE_ASM_MODVERSIONS 181 select HAVE_EBPF_JIT 182 select HAVE_C_RECORDMCOUNT 183 select HAVE_CMPXCHG_DOUBLE 184 select HAVE_CMPXCHG_LOCAL 185 select HAVE_CONTEXT_TRACKING_USER 186 select HAVE_DEBUG_KMEMLEAK 187 select HAVE_DMA_CONTIGUOUS 188 select HAVE_DYNAMIC_FTRACE 189 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 190 if $(cc-option,-fpatchable-function-entry=2) 191 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 192 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG) 193 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 194 if DYNAMIC_FTRACE_WITH_ARGS 195 select HAVE_EFFICIENT_UNALIGNED_ACCESS 196 select HAVE_FAST_GUP 197 select HAVE_FTRACE_MCOUNT_RECORD 198 select HAVE_FUNCTION_TRACER 199 select HAVE_FUNCTION_ERROR_INJECTION 200 select HAVE_FUNCTION_GRAPH_TRACER 201 select HAVE_GCC_PLUGINS 202 select HAVE_HW_BREAKPOINT if PERF_EVENTS 203 select HAVE_IOREMAP_PROT 204 select HAVE_IRQ_TIME_ACCOUNTING 205 select HAVE_KVM 206 select HAVE_NMI 207 select HAVE_PERF_EVENTS 208 select HAVE_PERF_REGS 209 select HAVE_PERF_USER_STACK_DUMP 210 select HAVE_PREEMPT_DYNAMIC_KEY 211 select HAVE_REGS_AND_STACK_ACCESS_API 212 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 213 select HAVE_FUNCTION_ARG_ACCESS_API 214 select MMU_GATHER_RCU_TABLE_FREE 215 select HAVE_RSEQ 216 select HAVE_STACKPROTECTOR 217 select HAVE_SYSCALL_TRACEPOINTS 218 select HAVE_KPROBES 219 select HAVE_KRETPROBES 220 select HAVE_GENERIC_VDSO 221 select IRQ_DOMAIN 222 select IRQ_FORCED_THREADING 223 select KASAN_VMALLOC if KASAN 224 select MODULES_USE_ELF_RELA 225 select NEED_DMA_MAP_STATE 226 select NEED_SG_DMA_LENGTH 227 select OF 228 select OF_EARLY_FLATTREE 229 select PCI_DOMAINS_GENERIC if PCI 230 select PCI_ECAM if (ACPI && PCI) 231 select PCI_SYSCALL if PCI 232 select POWER_RESET 233 select POWER_SUPPLY 234 select SPARSE_IRQ 235 select SWIOTLB 236 select SYSCTL_EXCEPTION_TRACE 237 select THREAD_INFO_IN_TASK 238 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 239 select TRACE_IRQFLAGS_SUPPORT 240 select TRACE_IRQFLAGS_NMI_SUPPORT 241 select HAVE_SOFTIRQ_ON_OWN_STACK 242 help 243 ARM 64-bit (AArch64) Linux support. 244 245config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 246 def_bool CC_IS_CLANG 247 # https://github.com/ClangBuiltLinux/linux/issues/1507 248 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 249 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 250 251config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 252 def_bool CC_IS_GCC 253 depends on $(cc-option,-fpatchable-function-entry=2) 254 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 255 256config 64BIT 257 def_bool y 258 259config MMU 260 def_bool y 261 262config ARM64_PAGE_SHIFT 263 int 264 default 16 if ARM64_64K_PAGES 265 default 14 if ARM64_16K_PAGES 266 default 12 267 268config ARM64_CONT_PTE_SHIFT 269 int 270 default 5 if ARM64_64K_PAGES 271 default 7 if ARM64_16K_PAGES 272 default 4 273 274config ARM64_CONT_PMD_SHIFT 275 int 276 default 5 if ARM64_64K_PAGES 277 default 5 if ARM64_16K_PAGES 278 default 4 279 280config ARCH_MMAP_RND_BITS_MIN 281 default 14 if ARM64_64K_PAGES 282 default 16 if ARM64_16K_PAGES 283 default 18 284 285# max bits determined by the following formula: 286# VA_BITS - PAGE_SHIFT - 3 287config ARCH_MMAP_RND_BITS_MAX 288 default 19 if ARM64_VA_BITS=36 289 default 24 if ARM64_VA_BITS=39 290 default 27 if ARM64_VA_BITS=42 291 default 30 if ARM64_VA_BITS=47 292 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 293 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 294 default 33 if ARM64_VA_BITS=48 295 default 14 if ARM64_64K_PAGES 296 default 16 if ARM64_16K_PAGES 297 default 18 298 299config ARCH_MMAP_RND_COMPAT_BITS_MIN 300 default 7 if ARM64_64K_PAGES 301 default 9 if ARM64_16K_PAGES 302 default 11 303 304config ARCH_MMAP_RND_COMPAT_BITS_MAX 305 default 16 306 307config NO_IOPORT_MAP 308 def_bool y if !PCI 309 310config STACKTRACE_SUPPORT 311 def_bool y 312 313config ILLEGAL_POINTER_VALUE 314 hex 315 default 0xdead000000000000 316 317config LOCKDEP_SUPPORT 318 def_bool y 319 320config GENERIC_BUG 321 def_bool y 322 depends on BUG 323 324config GENERIC_BUG_RELATIVE_POINTERS 325 def_bool y 326 depends on GENERIC_BUG 327 328config GENERIC_HWEIGHT 329 def_bool y 330 331config GENERIC_CSUM 332 def_bool y 333 334config GENERIC_CALIBRATE_DELAY 335 def_bool y 336 337config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 338 def_bool y 339 340config SMP 341 def_bool y 342 343config KERNEL_MODE_NEON 344 def_bool y 345 346config FIX_EARLYCON_MEM 347 def_bool y 348 349config PGTABLE_LEVELS 350 int 351 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 352 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 353 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 354 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 355 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 356 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 357 358config ARCH_SUPPORTS_UPROBES 359 def_bool y 360 361config ARCH_PROC_KCORE_TEXT 362 def_bool y 363 364config BROKEN_GAS_INST 365 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 366 367config KASAN_SHADOW_OFFSET 368 hex 369 depends on KASAN_GENERIC || KASAN_SW_TAGS 370 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 371 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 372 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 373 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 374 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 375 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 376 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 377 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 378 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 379 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 380 default 0xffffffffffffffff 381 382config UNWIND_TABLES 383 bool 384 385source "arch/arm64/Kconfig.platforms" 386 387menu "Kernel Features" 388 389menu "ARM errata workarounds via the alternatives framework" 390 391config ARM64_WORKAROUND_CLEAN_CACHE 392 bool 393 394config ARM64_ERRATUM_826319 395 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 396 default y 397 select ARM64_WORKAROUND_CLEAN_CACHE 398 help 399 This option adds an alternative code sequence to work around ARM 400 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 401 AXI master interface and an L2 cache. 402 403 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 404 and is unable to accept a certain write via this interface, it will 405 not progress on read data presented on the read data channel and the 406 system can deadlock. 407 408 The workaround promotes data cache clean instructions to 409 data cache clean-and-invalidate. 410 Please note that this does not necessarily enable the workaround, 411 as it depends on the alternative framework, which will only patch 412 the kernel if an affected CPU is detected. 413 414 If unsure, say Y. 415 416config ARM64_ERRATUM_827319 417 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 418 default y 419 select ARM64_WORKAROUND_CLEAN_CACHE 420 help 421 This option adds an alternative code sequence to work around ARM 422 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 423 master interface and an L2 cache. 424 425 Under certain conditions this erratum can cause a clean line eviction 426 to occur at the same time as another transaction to the same address 427 on the AMBA 5 CHI interface, which can cause data corruption if the 428 interconnect reorders the two transactions. 429 430 The workaround promotes data cache clean instructions to 431 data cache clean-and-invalidate. 432 Please note that this does not necessarily enable the workaround, 433 as it depends on the alternative framework, which will only patch 434 the kernel if an affected CPU is detected. 435 436 If unsure, say Y. 437 438config ARM64_ERRATUM_824069 439 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 440 default y 441 select ARM64_WORKAROUND_CLEAN_CACHE 442 help 443 This option adds an alternative code sequence to work around ARM 444 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 445 to a coherent interconnect. 446 447 If a Cortex-A53 processor is executing a store or prefetch for 448 write instruction at the same time as a processor in another 449 cluster is executing a cache maintenance operation to the same 450 address, then this erratum might cause a clean cache line to be 451 incorrectly marked as dirty. 452 453 The workaround promotes data cache clean instructions to 454 data cache clean-and-invalidate. 455 Please note that this option does not necessarily enable the 456 workaround, as it depends on the alternative framework, which will 457 only patch the kernel if an affected CPU is detected. 458 459 If unsure, say Y. 460 461config ARM64_ERRATUM_819472 462 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 463 default y 464 select ARM64_WORKAROUND_CLEAN_CACHE 465 help 466 This option adds an alternative code sequence to work around ARM 467 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 468 present when it is connected to a coherent interconnect. 469 470 If the processor is executing a load and store exclusive sequence at 471 the same time as a processor in another cluster is executing a cache 472 maintenance operation to the same address, then this erratum might 473 cause data corruption. 474 475 The workaround promotes data cache clean instructions to 476 data cache clean-and-invalidate. 477 Please note that this does not necessarily enable the workaround, 478 as it depends on the alternative framework, which will only patch 479 the kernel if an affected CPU is detected. 480 481 If unsure, say Y. 482 483config ARM64_ERRATUM_832075 484 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 485 default y 486 help 487 This option adds an alternative code sequence to work around ARM 488 erratum 832075 on Cortex-A57 parts up to r1p2. 489 490 Affected Cortex-A57 parts might deadlock when exclusive load/store 491 instructions to Write-Back memory are mixed with Device loads. 492 493 The workaround is to promote device loads to use Load-Acquire 494 semantics. 495 Please note that this does not necessarily enable the workaround, 496 as it depends on the alternative framework, which will only patch 497 the kernel if an affected CPU is detected. 498 499 If unsure, say Y. 500 501config ARM64_ERRATUM_834220 502 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 503 depends on KVM 504 default y 505 help 506 This option adds an alternative code sequence to work around ARM 507 erratum 834220 on Cortex-A57 parts up to r1p2. 508 509 Affected Cortex-A57 parts might report a Stage 2 translation 510 fault as the result of a Stage 1 fault for load crossing a 511 page boundary when there is a permission or device memory 512 alignment fault at Stage 1 and a translation fault at Stage 2. 513 514 The workaround is to verify that the Stage 1 translation 515 doesn't generate a fault before handling the Stage 2 fault. 516 Please note that this does not necessarily enable the workaround, 517 as it depends on the alternative framework, which will only patch 518 the kernel if an affected CPU is detected. 519 520 If unsure, say Y. 521 522config ARM64_ERRATUM_1742098 523 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 524 depends on COMPAT 525 default y 526 help 527 This option removes the AES hwcap for aarch32 user-space to 528 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 529 530 Affected parts may corrupt the AES state if an interrupt is 531 taken between a pair of AES instructions. These instructions 532 are only present if the cryptography extensions are present. 533 All software should have a fallback implementation for CPUs 534 that don't implement the cryptography extensions. 535 536 If unsure, say Y. 537 538config ARM64_ERRATUM_845719 539 bool "Cortex-A53: 845719: a load might read incorrect data" 540 depends on COMPAT 541 default y 542 help 543 This option adds an alternative code sequence to work around ARM 544 erratum 845719 on Cortex-A53 parts up to r0p4. 545 546 When running a compat (AArch32) userspace on an affected Cortex-A53 547 part, a load at EL0 from a virtual address that matches the bottom 32 548 bits of the virtual address used by a recent load at (AArch64) EL1 549 might return incorrect data. 550 551 The workaround is to write the contextidr_el1 register on exception 552 return to a 32-bit task. 553 Please note that this does not necessarily enable the workaround, 554 as it depends on the alternative framework, which will only patch 555 the kernel if an affected CPU is detected. 556 557 If unsure, say Y. 558 559config ARM64_ERRATUM_843419 560 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 561 default y 562 select ARM64_MODULE_PLTS if MODULES 563 help 564 This option links the kernel with '--fix-cortex-a53-843419' and 565 enables PLT support to replace certain ADRP instructions, which can 566 cause subsequent memory accesses to use an incorrect address on 567 Cortex-A53 parts up to r0p4. 568 569 If unsure, say Y. 570 571config ARM64_LD_HAS_FIX_ERRATUM_843419 572 def_bool $(ld-option,--fix-cortex-a53-843419) 573 574config ARM64_ERRATUM_1024718 575 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 576 default y 577 help 578 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 579 580 Affected Cortex-A55 cores (all revisions) could cause incorrect 581 update of the hardware dirty bit when the DBM/AP bits are updated 582 without a break-before-make. The workaround is to disable the usage 583 of hardware DBM locally on the affected cores. CPUs not affected by 584 this erratum will continue to use the feature. 585 586 If unsure, say Y. 587 588config ARM64_ERRATUM_1418040 589 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 590 default y 591 depends on COMPAT 592 help 593 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 594 errata 1188873 and 1418040. 595 596 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 597 cause register corruption when accessing the timer registers 598 from AArch32 userspace. 599 600 If unsure, say Y. 601 602config ARM64_WORKAROUND_SPECULATIVE_AT 603 bool 604 605config ARM64_ERRATUM_1165522 606 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 607 default y 608 select ARM64_WORKAROUND_SPECULATIVE_AT 609 help 610 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 611 612 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 613 corrupted TLBs by speculating an AT instruction during a guest 614 context switch. 615 616 If unsure, say Y. 617 618config ARM64_ERRATUM_1319367 619 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 620 default y 621 select ARM64_WORKAROUND_SPECULATIVE_AT 622 help 623 This option adds work arounds for ARM Cortex-A57 erratum 1319537 624 and A72 erratum 1319367 625 626 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 627 speculating an AT instruction during a guest context switch. 628 629 If unsure, say Y. 630 631config ARM64_ERRATUM_1530923 632 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 633 default y 634 select ARM64_WORKAROUND_SPECULATIVE_AT 635 help 636 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 637 638 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 639 corrupted TLBs by speculating an AT instruction during a guest 640 context switch. 641 642 If unsure, say Y. 643 644config ARM64_WORKAROUND_REPEAT_TLBI 645 bool 646 647config ARM64_ERRATUM_2441007 648 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 649 default y 650 select ARM64_WORKAROUND_REPEAT_TLBI 651 help 652 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 653 654 Under very rare circumstances, affected Cortex-A55 CPUs 655 may not handle a race between a break-before-make sequence on one 656 CPU, and another CPU accessing the same page. This could allow a 657 store to a page that has been unmapped. 658 659 Work around this by adding the affected CPUs to the list that needs 660 TLB sequences to be done twice. 661 662 If unsure, say Y. 663 664config ARM64_ERRATUM_1286807 665 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 666 default y 667 select ARM64_WORKAROUND_REPEAT_TLBI 668 help 669 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 670 671 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 672 address for a cacheable mapping of a location is being 673 accessed by a core while another core is remapping the virtual 674 address to a new physical page using the recommended 675 break-before-make sequence, then under very rare circumstances 676 TLBI+DSB completes before a read using the translation being 677 invalidated has been observed by other observers. The 678 workaround repeats the TLBI+DSB operation. 679 680config ARM64_ERRATUM_1463225 681 bool "Cortex-A76: Software Step might prevent interrupt recognition" 682 default y 683 help 684 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 685 686 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 687 of a system call instruction (SVC) can prevent recognition of 688 subsequent interrupts when software stepping is disabled in the 689 exception handler of the system call and either kernel debugging 690 is enabled or VHE is in use. 691 692 Work around the erratum by triggering a dummy step exception 693 when handling a system call from a task that is being stepped 694 in a VHE configuration of the kernel. 695 696 If unsure, say Y. 697 698config ARM64_ERRATUM_1542419 699 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 700 default y 701 help 702 This option adds a workaround for ARM Neoverse-N1 erratum 703 1542419. 704 705 Affected Neoverse-N1 cores could execute a stale instruction when 706 modified by another CPU. The workaround depends on a firmware 707 counterpart. 708 709 Workaround the issue by hiding the DIC feature from EL0. This 710 forces user-space to perform cache maintenance. 711 712 If unsure, say Y. 713 714config ARM64_ERRATUM_1508412 715 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 716 default y 717 help 718 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 719 720 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 721 of a store-exclusive or read of PAR_EL1 and a load with device or 722 non-cacheable memory attributes. The workaround depends on a firmware 723 counterpart. 724 725 KVM guests must also have the workaround implemented or they can 726 deadlock the system. 727 728 Work around the issue by inserting DMB SY barriers around PAR_EL1 729 register reads and warning KVM users. The DMB barrier is sufficient 730 to prevent a speculative PAR_EL1 read. 731 732 If unsure, say Y. 733 734config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 735 bool 736 737config ARM64_ERRATUM_2051678 738 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 739 default y 740 help 741 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 742 Affected Cortex-A510 might not respect the ordering rules for 743 hardware update of the page table's dirty bit. The workaround 744 is to not enable the feature on affected CPUs. 745 746 If unsure, say Y. 747 748config ARM64_ERRATUM_2077057 749 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 750 default y 751 help 752 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 753 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 754 expected, but a Pointer Authentication trap is taken instead. The 755 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 756 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 757 758 This can only happen when EL2 is stepping EL1. 759 760 When these conditions occur, the SPSR_EL2 value is unchanged from the 761 previous guest entry, and can be restored from the in-memory copy. 762 763 If unsure, say Y. 764 765config ARM64_ERRATUM_2658417 766 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 767 default y 768 help 769 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 770 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 771 BFMMLA or VMMLA instructions in rare circumstances when a pair of 772 A510 CPUs are using shared neon hardware. As the sharing is not 773 discoverable by the kernel, hide the BF16 HWCAP to indicate that 774 user-space should not be using these instructions. 775 776 If unsure, say Y. 777 778config ARM64_ERRATUM_2119858 779 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 780 default y 781 depends on CORESIGHT_TRBE 782 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 783 help 784 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 785 786 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 787 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 788 the event of a WRAP event. 789 790 Work around the issue by always making sure we move the TRBPTR_EL1 by 791 256 bytes before enabling the buffer and filling the first 256 bytes of 792 the buffer with ETM ignore packets upon disabling. 793 794 If unsure, say Y. 795 796config ARM64_ERRATUM_2139208 797 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 798 default y 799 depends on CORESIGHT_TRBE 800 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 801 help 802 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 803 804 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 805 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 806 the event of a WRAP event. 807 808 Work around the issue by always making sure we move the TRBPTR_EL1 by 809 256 bytes before enabling the buffer and filling the first 256 bytes of 810 the buffer with ETM ignore packets upon disabling. 811 812 If unsure, say Y. 813 814config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 815 bool 816 817config ARM64_ERRATUM_2054223 818 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 819 default y 820 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 821 help 822 Enable workaround for ARM Cortex-A710 erratum 2054223 823 824 Affected cores may fail to flush the trace data on a TSB instruction, when 825 the PE is in trace prohibited state. This will cause losing a few bytes 826 of the trace cached. 827 828 Workaround is to issue two TSB consecutively on affected cores. 829 830 If unsure, say Y. 831 832config ARM64_ERRATUM_2067961 833 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 834 default y 835 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 836 help 837 Enable workaround for ARM Neoverse-N2 erratum 2067961 838 839 Affected cores may fail to flush the trace data on a TSB instruction, when 840 the PE is in trace prohibited state. This will cause losing a few bytes 841 of the trace cached. 842 843 Workaround is to issue two TSB consecutively on affected cores. 844 845 If unsure, say Y. 846 847config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 848 bool 849 850config ARM64_ERRATUM_2253138 851 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 852 depends on CORESIGHT_TRBE 853 default y 854 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 855 help 856 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 857 858 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 859 for TRBE. Under some conditions, the TRBE might generate a write to the next 860 virtually addressed page following the last page of the TRBE address space 861 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 862 863 Work around this in the driver by always making sure that there is a 864 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 865 866 If unsure, say Y. 867 868config ARM64_ERRATUM_2224489 869 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 870 depends on CORESIGHT_TRBE 871 default y 872 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 873 help 874 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 875 876 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 877 for TRBE. Under some conditions, the TRBE might generate a write to the next 878 virtually addressed page following the last page of the TRBE address space 879 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 880 881 Work around this in the driver by always making sure that there is a 882 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 883 884 If unsure, say Y. 885 886config ARM64_ERRATUM_2441009 887 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 888 default y 889 select ARM64_WORKAROUND_REPEAT_TLBI 890 help 891 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 892 893 Under very rare circumstances, affected Cortex-A510 CPUs 894 may not handle a race between a break-before-make sequence on one 895 CPU, and another CPU accessing the same page. This could allow a 896 store to a page that has been unmapped. 897 898 Work around this by adding the affected CPUs to the list that needs 899 TLB sequences to be done twice. 900 901 If unsure, say Y. 902 903config ARM64_ERRATUM_2064142 904 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 905 depends on CORESIGHT_TRBE 906 default y 907 help 908 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 909 910 Affected Cortex-A510 core might fail to write into system registers after the 911 TRBE has been disabled. Under some conditions after the TRBE has been disabled 912 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 913 and TRBTRG_EL1 will be ignored and will not be effected. 914 915 Work around this in the driver by executing TSB CSYNC and DSB after collection 916 is stopped and before performing a system register write to one of the affected 917 registers. 918 919 If unsure, say Y. 920 921config ARM64_ERRATUM_2038923 922 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 923 depends on CORESIGHT_TRBE 924 default y 925 help 926 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 927 928 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 929 prohibited within the CPU. As a result, the trace buffer or trace buffer state 930 might be corrupted. This happens after TRBE buffer has been enabled by setting 931 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 932 execution changes from a context, in which trace is prohibited to one where it 933 isn't, or vice versa. In these mentioned conditions, the view of whether trace 934 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 935 the trace buffer state might be corrupted. 936 937 Work around this in the driver by preventing an inconsistent view of whether the 938 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 939 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 940 two ISB instructions if no ERET is to take place. 941 942 If unsure, say Y. 943 944config ARM64_ERRATUM_1902691 945 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 946 depends on CORESIGHT_TRBE 947 default y 948 help 949 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 950 951 Affected Cortex-A510 core might cause trace data corruption, when being written 952 into the memory. Effectively TRBE is broken and hence cannot be used to capture 953 trace data. 954 955 Work around this problem in the driver by just preventing TRBE initialization on 956 affected cpus. The firmware must have disabled the access to TRBE for the kernel 957 on such implementations. This will cover the kernel for any firmware that doesn't 958 do this already. 959 960 If unsure, say Y. 961 962config ARM64_ERRATUM_2457168 963 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 964 depends on ARM64_AMU_EXTN 965 default y 966 help 967 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 968 969 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 970 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 971 incorrectly giving a significantly higher output value. 972 973 Work around this problem by returning 0 when reading the affected counter in 974 key locations that results in disabling all users of this counter. This effect 975 is the same to firmware disabling affected counters. 976 977 If unsure, say Y. 978 979config CAVIUM_ERRATUM_22375 980 bool "Cavium erratum 22375, 24313" 981 default y 982 help 983 Enable workaround for errata 22375 and 24313. 984 985 This implements two gicv3-its errata workarounds for ThunderX. Both 986 with a small impact affecting only ITS table allocation. 987 988 erratum 22375: only alloc 8MB table size 989 erratum 24313: ignore memory access type 990 991 The fixes are in ITS initialization and basically ignore memory access 992 type and table size provided by the TYPER and BASER registers. 993 994 If unsure, say Y. 995 996config CAVIUM_ERRATUM_23144 997 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 998 depends on NUMA 999 default y 1000 help 1001 ITS SYNC command hang for cross node io and collections/cpu mapping. 1002 1003 If unsure, say Y. 1004 1005config CAVIUM_ERRATUM_23154 1006 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1007 default y 1008 help 1009 The ThunderX GICv3 implementation requires a modified version for 1010 reading the IAR status to ensure data synchronization 1011 (access to icc_iar1_el1 is not sync'ed before and after). 1012 1013 It also suffers from erratum 38545 (also present on Marvell's 1014 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1015 spuriously presented to the CPU interface. 1016 1017 If unsure, say Y. 1018 1019config CAVIUM_ERRATUM_27456 1020 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1021 default y 1022 help 1023 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1024 instructions may cause the icache to become corrupted if it 1025 contains data for a non-current ASID. The fix is to 1026 invalidate the icache when changing the mm context. 1027 1028 If unsure, say Y. 1029 1030config CAVIUM_ERRATUM_30115 1031 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1032 default y 1033 help 1034 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1035 1.2, and T83 Pass 1.0, KVM guest execution may disable 1036 interrupts in host. Trapping both GICv3 group-0 and group-1 1037 accesses sidesteps the issue. 1038 1039 If unsure, say Y. 1040 1041config CAVIUM_TX2_ERRATUM_219 1042 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1043 default y 1044 help 1045 On Cavium ThunderX2, a load, store or prefetch instruction between a 1046 TTBR update and the corresponding context synchronizing operation can 1047 cause a spurious Data Abort to be delivered to any hardware thread in 1048 the CPU core. 1049 1050 Work around the issue by avoiding the problematic code sequence and 1051 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1052 trap handler performs the corresponding register access, skips the 1053 instruction and ensures context synchronization by virtue of the 1054 exception return. 1055 1056 If unsure, say Y. 1057 1058config FUJITSU_ERRATUM_010001 1059 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1060 default y 1061 help 1062 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1063 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1064 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1065 This fault occurs under a specific hardware condition when a 1066 load/store instruction performs an address translation using: 1067 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1068 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1069 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1070 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1071 1072 The workaround is to ensure these bits are clear in TCR_ELx. 1073 The workaround only affects the Fujitsu-A64FX. 1074 1075 If unsure, say Y. 1076 1077config HISILICON_ERRATUM_161600802 1078 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1079 default y 1080 help 1081 The HiSilicon Hip07 SoC uses the wrong redistributor base 1082 when issued ITS commands such as VMOVP and VMAPP, and requires 1083 a 128kB offset to be applied to the target address in this commands. 1084 1085 If unsure, say Y. 1086 1087config QCOM_FALKOR_ERRATUM_1003 1088 bool "Falkor E1003: Incorrect translation due to ASID change" 1089 default y 1090 help 1091 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1092 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1093 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1094 then only for entries in the walk cache, since the leaf translation 1095 is unchanged. Work around the erratum by invalidating the walk cache 1096 entries for the trampoline before entering the kernel proper. 1097 1098config QCOM_FALKOR_ERRATUM_1009 1099 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1100 default y 1101 select ARM64_WORKAROUND_REPEAT_TLBI 1102 help 1103 On Falkor v1, the CPU may prematurely complete a DSB following a 1104 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1105 one more time to fix the issue. 1106 1107 If unsure, say Y. 1108 1109config QCOM_QDF2400_ERRATUM_0065 1110 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1111 default y 1112 help 1113 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1114 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1115 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1116 1117 If unsure, say Y. 1118 1119config QCOM_FALKOR_ERRATUM_E1041 1120 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1121 default y 1122 help 1123 Falkor CPU may speculatively fetch instructions from an improper 1124 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1125 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1126 1127 If unsure, say Y. 1128 1129config NVIDIA_CARMEL_CNP_ERRATUM 1130 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1131 default y 1132 help 1133 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1134 invalidate shared TLB entries installed by a different core, as it would 1135 on standard ARM cores. 1136 1137 If unsure, say Y. 1138 1139config SOCIONEXT_SYNQUACER_PREITS 1140 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1141 default y 1142 help 1143 Socionext Synquacer SoCs implement a separate h/w block to generate 1144 MSI doorbell writes with non-zero values for the device ID. 1145 1146 If unsure, say Y. 1147 1148endmenu # "ARM errata workarounds via the alternatives framework" 1149 1150choice 1151 prompt "Page size" 1152 default ARM64_4K_PAGES 1153 help 1154 Page size (translation granule) configuration. 1155 1156config ARM64_4K_PAGES 1157 bool "4KB" 1158 help 1159 This feature enables 4KB pages support. 1160 1161config ARM64_16K_PAGES 1162 bool "16KB" 1163 help 1164 The system will use 16KB pages support. AArch32 emulation 1165 requires applications compiled with 16K (or a multiple of 16K) 1166 aligned segments. 1167 1168config ARM64_64K_PAGES 1169 bool "64KB" 1170 help 1171 This feature enables 64KB pages support (4KB by default) 1172 allowing only two levels of page tables and faster TLB 1173 look-up. AArch32 emulation requires applications compiled 1174 with 64K aligned segments. 1175 1176endchoice 1177 1178choice 1179 prompt "Virtual address space size" 1180 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1181 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1182 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1183 help 1184 Allows choosing one of multiple possible virtual address 1185 space sizes. The level of translation table is determined by 1186 a combination of page size and virtual address space size. 1187 1188config ARM64_VA_BITS_36 1189 bool "36-bit" if EXPERT 1190 depends on ARM64_16K_PAGES 1191 1192config ARM64_VA_BITS_39 1193 bool "39-bit" 1194 depends on ARM64_4K_PAGES 1195 1196config ARM64_VA_BITS_42 1197 bool "42-bit" 1198 depends on ARM64_64K_PAGES 1199 1200config ARM64_VA_BITS_47 1201 bool "47-bit" 1202 depends on ARM64_16K_PAGES 1203 1204config ARM64_VA_BITS_48 1205 bool "48-bit" 1206 1207config ARM64_VA_BITS_52 1208 bool "52-bit" 1209 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1210 help 1211 Enable 52-bit virtual addressing for userspace when explicitly 1212 requested via a hint to mmap(). The kernel will also use 52-bit 1213 virtual addresses for its own mappings (provided HW support for 1214 this feature is available, otherwise it reverts to 48-bit). 1215 1216 NOTE: Enabling 52-bit virtual addressing in conjunction with 1217 ARMv8.3 Pointer Authentication will result in the PAC being 1218 reduced from 7 bits to 3 bits, which may have a significant 1219 impact on its susceptibility to brute-force attacks. 1220 1221 If unsure, select 48-bit virtual addressing instead. 1222 1223endchoice 1224 1225config ARM64_FORCE_52BIT 1226 bool "Force 52-bit virtual addresses for userspace" 1227 depends on ARM64_VA_BITS_52 && EXPERT 1228 help 1229 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1230 to maintain compatibility with older software by providing 48-bit VAs 1231 unless a hint is supplied to mmap. 1232 1233 This configuration option disables the 48-bit compatibility logic, and 1234 forces all userspace addresses to be 52-bit on HW that supports it. One 1235 should only enable this configuration option for stress testing userspace 1236 memory management code. If unsure say N here. 1237 1238config ARM64_VA_BITS 1239 int 1240 default 36 if ARM64_VA_BITS_36 1241 default 39 if ARM64_VA_BITS_39 1242 default 42 if ARM64_VA_BITS_42 1243 default 47 if ARM64_VA_BITS_47 1244 default 48 if ARM64_VA_BITS_48 1245 default 52 if ARM64_VA_BITS_52 1246 1247choice 1248 prompt "Physical address space size" 1249 default ARM64_PA_BITS_48 1250 help 1251 Choose the maximum physical address range that the kernel will 1252 support. 1253 1254config ARM64_PA_BITS_48 1255 bool "48-bit" 1256 1257config ARM64_PA_BITS_52 1258 bool "52-bit (ARMv8.2)" 1259 depends on ARM64_64K_PAGES 1260 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1261 help 1262 Enable support for a 52-bit physical address space, introduced as 1263 part of the ARMv8.2-LPA extension. 1264 1265 With this enabled, the kernel will also continue to work on CPUs that 1266 do not support ARMv8.2-LPA, but with some added memory overhead (and 1267 minor performance overhead). 1268 1269endchoice 1270 1271config ARM64_PA_BITS 1272 int 1273 default 48 if ARM64_PA_BITS_48 1274 default 52 if ARM64_PA_BITS_52 1275 1276choice 1277 prompt "Endianness" 1278 default CPU_LITTLE_ENDIAN 1279 help 1280 Select the endianness of data accesses performed by the CPU. Userspace 1281 applications will need to be compiled and linked for the endianness 1282 that is selected here. 1283 1284config CPU_BIG_ENDIAN 1285 bool "Build big-endian kernel" 1286 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1287 help 1288 Say Y if you plan on running a kernel with a big-endian userspace. 1289 1290config CPU_LITTLE_ENDIAN 1291 bool "Build little-endian kernel" 1292 help 1293 Say Y if you plan on running a kernel with a little-endian userspace. 1294 This is usually the case for distributions targeting arm64. 1295 1296endchoice 1297 1298config SCHED_MC 1299 bool "Multi-core scheduler support" 1300 help 1301 Multi-core scheduler support improves the CPU scheduler's decision 1302 making when dealing with multi-core CPU chips at a cost of slightly 1303 increased overhead in some places. If unsure say N here. 1304 1305config SCHED_CLUSTER 1306 bool "Cluster scheduler support" 1307 help 1308 Cluster scheduler support improves the CPU scheduler's decision 1309 making when dealing with machines that have clusters of CPUs. 1310 Cluster usually means a couple of CPUs which are placed closely 1311 by sharing mid-level caches, last-level cache tags or internal 1312 busses. 1313 1314config SCHED_SMT 1315 bool "SMT scheduler support" 1316 help 1317 Improves the CPU scheduler's decision making when dealing with 1318 MultiThreading at a cost of slightly increased overhead in some 1319 places. If unsure say N here. 1320 1321config NR_CPUS 1322 int "Maximum number of CPUs (2-4096)" 1323 range 2 4096 1324 default "256" 1325 1326config HOTPLUG_CPU 1327 bool "Support for hot-pluggable CPUs" 1328 select GENERIC_IRQ_MIGRATION 1329 help 1330 Say Y here to experiment with turning CPUs off and on. CPUs 1331 can be controlled through /sys/devices/system/cpu. 1332 1333# Common NUMA Features 1334config NUMA 1335 bool "NUMA Memory Allocation and Scheduler Support" 1336 select GENERIC_ARCH_NUMA 1337 select ACPI_NUMA if ACPI 1338 select OF_NUMA 1339 select HAVE_SETUP_PER_CPU_AREA 1340 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1341 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1342 select USE_PERCPU_NUMA_NODE_ID 1343 help 1344 Enable NUMA (Non-Uniform Memory Access) support. 1345 1346 The kernel will try to allocate memory used by a CPU on the 1347 local memory of the CPU and add some more 1348 NUMA awareness to the kernel. 1349 1350config NODES_SHIFT 1351 int "Maximum NUMA Nodes (as a power of 2)" 1352 range 1 10 1353 default "4" 1354 depends on NUMA 1355 help 1356 Specify the maximum number of NUMA Nodes available on the target 1357 system. Increases memory reserved to accommodate various tables. 1358 1359source "kernel/Kconfig.hz" 1360 1361config ARCH_SPARSEMEM_ENABLE 1362 def_bool y 1363 select SPARSEMEM_VMEMMAP_ENABLE 1364 select SPARSEMEM_VMEMMAP 1365 1366config HW_PERF_EVENTS 1367 def_bool y 1368 depends on ARM_PMU 1369 1370# Supported by clang >= 7.0 or GCC >= 12.0.0 1371config CC_HAVE_SHADOW_CALL_STACK 1372 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1373 1374config PARAVIRT 1375 bool "Enable paravirtualization code" 1376 help 1377 This changes the kernel so it can modify itself when it is run 1378 under a hypervisor, potentially improving performance significantly 1379 over full virtualization. 1380 1381config PARAVIRT_TIME_ACCOUNTING 1382 bool "Paravirtual steal time accounting" 1383 select PARAVIRT 1384 help 1385 Select this option to enable fine granularity task steal time 1386 accounting. Time spent executing other tasks in parallel with 1387 the current vCPU is discounted from the vCPU power. To account for 1388 that, there can be a small performance impact. 1389 1390 If in doubt, say N here. 1391 1392config KEXEC 1393 depends on PM_SLEEP_SMP 1394 select KEXEC_CORE 1395 bool "kexec system call" 1396 help 1397 kexec is a system call that implements the ability to shutdown your 1398 current kernel, and to start another kernel. It is like a reboot 1399 but it is independent of the system firmware. And like a reboot 1400 you can start any kernel with it, not just Linux. 1401 1402config KEXEC_FILE 1403 bool "kexec file based system call" 1404 select KEXEC_CORE 1405 select HAVE_IMA_KEXEC if IMA 1406 help 1407 This is new version of kexec system call. This system call is 1408 file based and takes file descriptors as system call argument 1409 for kernel and initramfs as opposed to list of segments as 1410 accepted by previous system call. 1411 1412config KEXEC_SIG 1413 bool "Verify kernel signature during kexec_file_load() syscall" 1414 depends on KEXEC_FILE 1415 help 1416 Select this option to verify a signature with loaded kernel 1417 image. If configured, any attempt of loading a image without 1418 valid signature will fail. 1419 1420 In addition to that option, you need to enable signature 1421 verification for the corresponding kernel image type being 1422 loaded in order for this to work. 1423 1424config KEXEC_IMAGE_VERIFY_SIG 1425 bool "Enable Image signature verification support" 1426 default y 1427 depends on KEXEC_SIG 1428 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1429 help 1430 Enable Image signature verification support. 1431 1432comment "Support for PE file signature verification disabled" 1433 depends on KEXEC_SIG 1434 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1435 1436config CRASH_DUMP 1437 bool "Build kdump crash kernel" 1438 help 1439 Generate crash dump after being started by kexec. This should 1440 be normally only set in special crash dump kernels which are 1441 loaded in the main kernel with kexec-tools into a specially 1442 reserved region and then later executed after a crash by 1443 kdump/kexec. 1444 1445 For more details see Documentation/admin-guide/kdump/kdump.rst 1446 1447config TRANS_TABLE 1448 def_bool y 1449 depends on HIBERNATION || KEXEC_CORE 1450 1451config XEN_DOM0 1452 def_bool y 1453 depends on XEN 1454 1455config XEN 1456 bool "Xen guest support on ARM64" 1457 depends on ARM64 && OF 1458 select SWIOTLB_XEN 1459 select PARAVIRT 1460 help 1461 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1462 1463# include/linux/mmzone.h requires the following to be true: 1464# 1465# MAX_ORDER - 1 + PAGE_SHIFT <= SECTION_SIZE_BITS 1466# 1467# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS + 1 - PAGE_SHIFT: 1468# 1469# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1470# ----+-------------------+--------------+-----------------+--------------------+ 1471# 4K | 27 | 12 | 16 | 11 | 1472# 16K | 27 | 14 | 14 | 12 | 1473# 64K | 29 | 16 | 14 | 14 | 1474config ARCH_FORCE_MAX_ORDER 1475 int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES 1476 default "14" if ARM64_64K_PAGES 1477 range 12 14 if ARM64_16K_PAGES 1478 default "12" if ARM64_16K_PAGES 1479 range 11 16 if ARM64_4K_PAGES 1480 default "11" 1481 help 1482 The kernel memory allocator divides physically contiguous memory 1483 blocks into "zones", where each zone is a power of two number of 1484 pages. This option selects the largest power of two that the kernel 1485 keeps in the memory allocator. If you need to allocate very large 1486 blocks of physically contiguous memory, then you may need to 1487 increase this value. 1488 1489 This config option is actually maximum order plus one. For example, 1490 a value of 11 means that the largest free memory block is 2^10 pages. 1491 1492 We make sure that we can allocate up to a HugePage size for each configuration. 1493 Hence we have : 1494 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1495 1496 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1497 4M allocations matching the default size used by generic code. 1498 1499config UNMAP_KERNEL_AT_EL0 1500 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1501 default y 1502 help 1503 Speculation attacks against some high-performance processors can 1504 be used to bypass MMU permission checks and leak kernel data to 1505 userspace. This can be defended against by unmapping the kernel 1506 when running in userspace, mapping it back in on exception entry 1507 via a trampoline page in the vector table. 1508 1509 If unsure, say Y. 1510 1511config MITIGATE_SPECTRE_BRANCH_HISTORY 1512 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1513 default y 1514 help 1515 Speculation attacks against some high-performance processors can 1516 make use of branch history to influence future speculation. 1517 When taking an exception from user-space, a sequence of branches 1518 or a firmware call overwrites the branch history. 1519 1520config RODATA_FULL_DEFAULT_ENABLED 1521 bool "Apply r/o permissions of VM areas also to their linear aliases" 1522 default y 1523 help 1524 Apply read-only attributes of VM areas to the linear alias of 1525 the backing pages as well. This prevents code or read-only data 1526 from being modified (inadvertently or intentionally) via another 1527 mapping of the same memory page. This additional enhancement can 1528 be turned off at runtime by passing rodata=[off|on] (and turned on 1529 with rodata=full if this option is set to 'n') 1530 1531 This requires the linear region to be mapped down to pages, 1532 which may adversely affect performance in some cases. 1533 1534config ARM64_SW_TTBR0_PAN 1535 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1536 help 1537 Enabling this option prevents the kernel from accessing 1538 user-space memory directly by pointing TTBR0_EL1 to a reserved 1539 zeroed area and reserved ASID. The user access routines 1540 restore the valid TTBR0_EL1 temporarily. 1541 1542config ARM64_TAGGED_ADDR_ABI 1543 bool "Enable the tagged user addresses syscall ABI" 1544 default y 1545 help 1546 When this option is enabled, user applications can opt in to a 1547 relaxed ABI via prctl() allowing tagged addresses to be passed 1548 to system calls as pointer arguments. For details, see 1549 Documentation/arm64/tagged-address-abi.rst. 1550 1551menuconfig COMPAT 1552 bool "Kernel support for 32-bit EL0" 1553 depends on ARM64_4K_PAGES || EXPERT 1554 select HAVE_UID16 1555 select OLD_SIGSUSPEND3 1556 select COMPAT_OLD_SIGACTION 1557 help 1558 This option enables support for a 32-bit EL0 running under a 64-bit 1559 kernel at EL1. AArch32-specific components such as system calls, 1560 the user helper functions, VFP support and the ptrace interface are 1561 handled appropriately by the kernel. 1562 1563 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1564 that you will only be able to execute AArch32 binaries that were compiled 1565 with page size aligned segments. 1566 1567 If you want to execute 32-bit userspace applications, say Y. 1568 1569if COMPAT 1570 1571config KUSER_HELPERS 1572 bool "Enable kuser helpers page for 32-bit applications" 1573 default y 1574 help 1575 Warning: disabling this option may break 32-bit user programs. 1576 1577 Provide kuser helpers to compat tasks. The kernel provides 1578 helper code to userspace in read only form at a fixed location 1579 to allow userspace to be independent of the CPU type fitted to 1580 the system. This permits binaries to be run on ARMv4 through 1581 to ARMv8 without modification. 1582 1583 See Documentation/arm/kernel_user_helpers.rst for details. 1584 1585 However, the fixed address nature of these helpers can be used 1586 by ROP (return orientated programming) authors when creating 1587 exploits. 1588 1589 If all of the binaries and libraries which run on your platform 1590 are built specifically for your platform, and make no use of 1591 these helpers, then you can turn this option off to hinder 1592 such exploits. However, in that case, if a binary or library 1593 relying on those helpers is run, it will not function correctly. 1594 1595 Say N here only if you are absolutely certain that you do not 1596 need these helpers; otherwise, the safe option is to say Y. 1597 1598config COMPAT_VDSO 1599 bool "Enable vDSO for 32-bit applications" 1600 depends on !CPU_BIG_ENDIAN 1601 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1602 select GENERIC_COMPAT_VDSO 1603 default y 1604 help 1605 Place in the process address space of 32-bit applications an 1606 ELF shared object providing fast implementations of gettimeofday 1607 and clock_gettime. 1608 1609 You must have a 32-bit build of glibc 2.22 or later for programs 1610 to seamlessly take advantage of this. 1611 1612config THUMB2_COMPAT_VDSO 1613 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1614 depends on COMPAT_VDSO 1615 default y 1616 help 1617 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1618 otherwise with '-marm'. 1619 1620config COMPAT_ALIGNMENT_FIXUPS 1621 bool "Fix up misaligned multi-word loads and stores in user space" 1622 1623menuconfig ARMV8_DEPRECATED 1624 bool "Emulate deprecated/obsolete ARMv8 instructions" 1625 depends on SYSCTL 1626 help 1627 Legacy software support may require certain instructions 1628 that have been deprecated or obsoleted in the architecture. 1629 1630 Enable this config to enable selective emulation of these 1631 features. 1632 1633 If unsure, say Y 1634 1635if ARMV8_DEPRECATED 1636 1637config SWP_EMULATION 1638 bool "Emulate SWP/SWPB instructions" 1639 help 1640 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1641 they are always undefined. Say Y here to enable software 1642 emulation of these instructions for userspace using LDXR/STXR. 1643 This feature can be controlled at runtime with the abi.swp 1644 sysctl which is disabled by default. 1645 1646 In some older versions of glibc [<=2.8] SWP is used during futex 1647 trylock() operations with the assumption that the code will not 1648 be preempted. This invalid assumption may be more likely to fail 1649 with SWP emulation enabled, leading to deadlock of the user 1650 application. 1651 1652 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1653 on an external transaction monitoring block called a global 1654 monitor to maintain update atomicity. If your system does not 1655 implement a global monitor, this option can cause programs that 1656 perform SWP operations to uncached memory to deadlock. 1657 1658 If unsure, say Y 1659 1660config CP15_BARRIER_EMULATION 1661 bool "Emulate CP15 Barrier instructions" 1662 help 1663 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1664 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1665 strongly recommended to use the ISB, DSB, and DMB 1666 instructions instead. 1667 1668 Say Y here to enable software emulation of these 1669 instructions for AArch32 userspace code. When this option is 1670 enabled, CP15 barrier usage is traced which can help 1671 identify software that needs updating. This feature can be 1672 controlled at runtime with the abi.cp15_barrier sysctl. 1673 1674 If unsure, say Y 1675 1676config SETEND_EMULATION 1677 bool "Emulate SETEND instruction" 1678 help 1679 The SETEND instruction alters the data-endianness of the 1680 AArch32 EL0, and is deprecated in ARMv8. 1681 1682 Say Y here to enable software emulation of the instruction 1683 for AArch32 userspace code. This feature can be controlled 1684 at runtime with the abi.setend sysctl. 1685 1686 Note: All the cpus on the system must have mixed endian support at EL0 1687 for this feature to be enabled. If a new CPU - which doesn't support mixed 1688 endian - is hotplugged in after this feature has been enabled, there could 1689 be unexpected results in the applications. 1690 1691 If unsure, say Y 1692endif # ARMV8_DEPRECATED 1693 1694endif # COMPAT 1695 1696menu "ARMv8.1 architectural features" 1697 1698config ARM64_HW_AFDBM 1699 bool "Support for hardware updates of the Access and Dirty page flags" 1700 default y 1701 help 1702 The ARMv8.1 architecture extensions introduce support for 1703 hardware updates of the access and dirty information in page 1704 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1705 capable processors, accesses to pages with PTE_AF cleared will 1706 set this bit instead of raising an access flag fault. 1707 Similarly, writes to read-only pages with the DBM bit set will 1708 clear the read-only bit (AP[2]) instead of raising a 1709 permission fault. 1710 1711 Kernels built with this configuration option enabled continue 1712 to work on pre-ARMv8.1 hardware and the performance impact is 1713 minimal. If unsure, say Y. 1714 1715config ARM64_PAN 1716 bool "Enable support for Privileged Access Never (PAN)" 1717 default y 1718 help 1719 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1720 prevents the kernel or hypervisor from accessing user-space (EL0) 1721 memory directly. 1722 1723 Choosing this option will cause any unprotected (not using 1724 copy_to_user et al) memory access to fail with a permission fault. 1725 1726 The feature is detected at runtime, and will remain as a 'nop' 1727 instruction if the cpu does not implement the feature. 1728 1729config AS_HAS_LDAPR 1730 def_bool $(as-instr,.arch_extension rcpc) 1731 1732config AS_HAS_LSE_ATOMICS 1733 def_bool $(as-instr,.arch_extension lse) 1734 1735config ARM64_LSE_ATOMICS 1736 bool 1737 default ARM64_USE_LSE_ATOMICS 1738 depends on AS_HAS_LSE_ATOMICS 1739 1740config ARM64_USE_LSE_ATOMICS 1741 bool "Atomic instructions" 1742 default y 1743 help 1744 As part of the Large System Extensions, ARMv8.1 introduces new 1745 atomic instructions that are designed specifically to scale in 1746 very large systems. 1747 1748 Say Y here to make use of these instructions for the in-kernel 1749 atomic routines. This incurs a small overhead on CPUs that do 1750 not support these instructions and requires the kernel to be 1751 built with binutils >= 2.25 in order for the new instructions 1752 to be used. 1753 1754endmenu # "ARMv8.1 architectural features" 1755 1756menu "ARMv8.2 architectural features" 1757 1758config AS_HAS_ARMV8_2 1759 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1760 1761config AS_HAS_SHA3 1762 def_bool $(as-instr,.arch armv8.2-a+sha3) 1763 1764config ARM64_PMEM 1765 bool "Enable support for persistent memory" 1766 select ARCH_HAS_PMEM_API 1767 select ARCH_HAS_UACCESS_FLUSHCACHE 1768 help 1769 Say Y to enable support for the persistent memory API based on the 1770 ARMv8.2 DCPoP feature. 1771 1772 The feature is detected at runtime, and the kernel will use DC CVAC 1773 operations if DC CVAP is not supported (following the behaviour of 1774 DC CVAP itself if the system does not define a point of persistence). 1775 1776config ARM64_RAS_EXTN 1777 bool "Enable support for RAS CPU Extensions" 1778 default y 1779 help 1780 CPUs that support the Reliability, Availability and Serviceability 1781 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1782 errors, classify them and report them to software. 1783 1784 On CPUs with these extensions system software can use additional 1785 barriers to determine if faults are pending and read the 1786 classification from a new set of registers. 1787 1788 Selecting this feature will allow the kernel to use these barriers 1789 and access the new registers if the system supports the extension. 1790 Platform RAS features may additionally depend on firmware support. 1791 1792config ARM64_CNP 1793 bool "Enable support for Common Not Private (CNP) translations" 1794 default y 1795 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1796 help 1797 Common Not Private (CNP) allows translation table entries to 1798 be shared between different PEs in the same inner shareable 1799 domain, so the hardware can use this fact to optimise the 1800 caching of such entries in the TLB. 1801 1802 Selecting this option allows the CNP feature to be detected 1803 at runtime, and does not affect PEs that do not implement 1804 this feature. 1805 1806endmenu # "ARMv8.2 architectural features" 1807 1808menu "ARMv8.3 architectural features" 1809 1810config ARM64_PTR_AUTH 1811 bool "Enable support for pointer authentication" 1812 default y 1813 help 1814 Pointer authentication (part of the ARMv8.3 Extensions) provides 1815 instructions for signing and authenticating pointers against secret 1816 keys, which can be used to mitigate Return Oriented Programming (ROP) 1817 and other attacks. 1818 1819 This option enables these instructions at EL0 (i.e. for userspace). 1820 Choosing this option will cause the kernel to initialise secret keys 1821 for each process at exec() time, with these keys being 1822 context-switched along with the process. 1823 1824 The feature is detected at runtime. If the feature is not present in 1825 hardware it will not be advertised to userspace/KVM guest nor will it 1826 be enabled. 1827 1828 If the feature is present on the boot CPU but not on a late CPU, then 1829 the late CPU will be parked. Also, if the boot CPU does not have 1830 address auth and the late CPU has then the late CPU will still boot 1831 but with the feature disabled. On such a system, this option should 1832 not be selected. 1833 1834config ARM64_PTR_AUTH_KERNEL 1835 bool "Use pointer authentication for kernel" 1836 default y 1837 depends on ARM64_PTR_AUTH 1838 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1839 # Modern compilers insert a .note.gnu.property section note for PAC 1840 # which is only understood by binutils starting with version 2.33.1. 1841 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1842 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1843 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1844 help 1845 If the compiler supports the -mbranch-protection or 1846 -msign-return-address flag (e.g. GCC 7 or later), then this option 1847 will cause the kernel itself to be compiled with return address 1848 protection. In this case, and if the target hardware is known to 1849 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1850 disabled with minimal loss of protection. 1851 1852 This feature works with FUNCTION_GRAPH_TRACER option only if 1853 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1854 1855config CC_HAS_BRANCH_PROT_PAC_RET 1856 # GCC 9 or later, clang 8 or later 1857 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1858 1859config CC_HAS_SIGN_RETURN_ADDRESS 1860 # GCC 7, 8 1861 def_bool $(cc-option,-msign-return-address=all) 1862 1863config AS_HAS_ARMV8_3 1864 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1865 1866config AS_HAS_CFI_NEGATE_RA_STATE 1867 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1868 1869endmenu # "ARMv8.3 architectural features" 1870 1871menu "ARMv8.4 architectural features" 1872 1873config ARM64_AMU_EXTN 1874 bool "Enable support for the Activity Monitors Unit CPU extension" 1875 default y 1876 help 1877 The activity monitors extension is an optional extension introduced 1878 by the ARMv8.4 CPU architecture. This enables support for version 1 1879 of the activity monitors architecture, AMUv1. 1880 1881 To enable the use of this extension on CPUs that implement it, say Y. 1882 1883 Note that for architectural reasons, firmware _must_ implement AMU 1884 support when running on CPUs that present the activity monitors 1885 extension. The required support is present in: 1886 * Version 1.5 and later of the ARM Trusted Firmware 1887 1888 For kernels that have this configuration enabled but boot with broken 1889 firmware, you may need to say N here until the firmware is fixed. 1890 Otherwise you may experience firmware panics or lockups when 1891 accessing the counter registers. Even if you are not observing these 1892 symptoms, the values returned by the register reads might not 1893 correctly reflect reality. Most commonly, the value read will be 0, 1894 indicating that the counter is not enabled. 1895 1896config AS_HAS_ARMV8_4 1897 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1898 1899config ARM64_TLB_RANGE 1900 bool "Enable support for tlbi range feature" 1901 default y 1902 depends on AS_HAS_ARMV8_4 1903 help 1904 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1905 range of input addresses. 1906 1907 The feature introduces new assembly instructions, and they were 1908 support when binutils >= 2.30. 1909 1910endmenu # "ARMv8.4 architectural features" 1911 1912menu "ARMv8.5 architectural features" 1913 1914config AS_HAS_ARMV8_5 1915 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1916 1917config ARM64_BTI 1918 bool "Branch Target Identification support" 1919 default y 1920 help 1921 Branch Target Identification (part of the ARMv8.5 Extensions) 1922 provides a mechanism to limit the set of locations to which computed 1923 branch instructions such as BR or BLR can jump. 1924 1925 To make use of BTI on CPUs that support it, say Y. 1926 1927 BTI is intended to provide complementary protection to other control 1928 flow integrity protection mechanisms, such as the Pointer 1929 authentication mechanism provided as part of the ARMv8.3 Extensions. 1930 For this reason, it does not make sense to enable this option without 1931 also enabling support for pointer authentication. Thus, when 1932 enabling this option you should also select ARM64_PTR_AUTH=y. 1933 1934 Userspace binaries must also be specifically compiled to make use of 1935 this mechanism. If you say N here or the hardware does not support 1936 BTI, such binaries can still run, but you get no additional 1937 enforcement of branch destinations. 1938 1939config ARM64_BTI_KERNEL 1940 bool "Use Branch Target Identification for kernel" 1941 default y 1942 depends on ARM64_BTI 1943 depends on ARM64_PTR_AUTH_KERNEL 1944 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1945 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1946 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1947 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1948 depends on !CC_IS_GCC 1949 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1950 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1951 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1952 help 1953 Build the kernel with Branch Target Identification annotations 1954 and enable enforcement of this for kernel code. When this option 1955 is enabled and the system supports BTI all kernel code including 1956 modular code must have BTI enabled. 1957 1958config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1959 # GCC 9 or later, clang 8 or later 1960 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1961 1962config ARM64_E0PD 1963 bool "Enable support for E0PD" 1964 default y 1965 help 1966 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1967 that EL0 accesses made via TTBR1 always fault in constant time, 1968 providing similar benefits to KASLR as those provided by KPTI, but 1969 with lower overhead and without disrupting legitimate access to 1970 kernel memory such as SPE. 1971 1972 This option enables E0PD for TTBR1 where available. 1973 1974config ARM64_AS_HAS_MTE 1975 # Initial support for MTE went in binutils 2.32.0, checked with 1976 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1977 # as a late addition to the final architecture spec (LDGM/STGM) 1978 # is only supported in the newer 2.32.x and 2.33 binutils 1979 # versions, hence the extra "stgm" instruction check below. 1980 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1981 1982config ARM64_MTE 1983 bool "Memory Tagging Extension support" 1984 default y 1985 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1986 depends on AS_HAS_ARMV8_5 1987 depends on AS_HAS_LSE_ATOMICS 1988 # Required for tag checking in the uaccess routines 1989 depends on ARM64_PAN 1990 select ARCH_HAS_SUBPAGE_FAULTS 1991 select ARCH_USES_HIGH_VMA_FLAGS 1992 select ARCH_USES_PG_ARCH_X 1993 help 1994 Memory Tagging (part of the ARMv8.5 Extensions) provides 1995 architectural support for run-time, always-on detection of 1996 various classes of memory error to aid with software debugging 1997 to eliminate vulnerabilities arising from memory-unsafe 1998 languages. 1999 2000 This option enables the support for the Memory Tagging 2001 Extension at EL0 (i.e. for userspace). 2002 2003 Selecting this option allows the feature to be detected at 2004 runtime. Any secondary CPU not implementing this feature will 2005 not be allowed a late bring-up. 2006 2007 Userspace binaries that want to use this feature must 2008 explicitly opt in. The mechanism for the userspace is 2009 described in: 2010 2011 Documentation/arm64/memory-tagging-extension.rst. 2012 2013endmenu # "ARMv8.5 architectural features" 2014 2015menu "ARMv8.7 architectural features" 2016 2017config ARM64_EPAN 2018 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2019 default y 2020 depends on ARM64_PAN 2021 help 2022 Enhanced Privileged Access Never (EPAN) allows Privileged 2023 Access Never to be used with Execute-only mappings. 2024 2025 The feature is detected at runtime, and will remain disabled 2026 if the cpu does not implement the feature. 2027endmenu # "ARMv8.7 architectural features" 2028 2029config ARM64_SVE 2030 bool "ARM Scalable Vector Extension support" 2031 default y 2032 help 2033 The Scalable Vector Extension (SVE) is an extension to the AArch64 2034 execution state which complements and extends the SIMD functionality 2035 of the base architecture to support much larger vectors and to enable 2036 additional vectorisation opportunities. 2037 2038 To enable use of this extension on CPUs that implement it, say Y. 2039 2040 On CPUs that support the SVE2 extensions, this option will enable 2041 those too. 2042 2043 Note that for architectural reasons, firmware _must_ implement SVE 2044 support when running on SVE capable hardware. The required support 2045 is present in: 2046 2047 * version 1.5 and later of the ARM Trusted Firmware 2048 * the AArch64 boot wrapper since commit 5e1261e08abf 2049 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2050 2051 For other firmware implementations, consult the firmware documentation 2052 or vendor. 2053 2054 If you need the kernel to boot on SVE-capable hardware with broken 2055 firmware, you may need to say N here until you get your firmware 2056 fixed. Otherwise, you may experience firmware panics or lockups when 2057 booting the kernel. If unsure and you are not observing these 2058 symptoms, you should assume that it is safe to say Y. 2059 2060config ARM64_SME 2061 bool "ARM Scalable Matrix Extension support" 2062 default y 2063 depends on ARM64_SVE 2064 help 2065 The Scalable Matrix Extension (SME) is an extension to the AArch64 2066 execution state which utilises a substantial subset of the SVE 2067 instruction set, together with the addition of new architectural 2068 register state capable of holding two dimensional matrix tiles to 2069 enable various matrix operations. 2070 2071config ARM64_MODULE_PLTS 2072 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2073 depends on MODULES 2074 select HAVE_MOD_ARCH_SPECIFIC 2075 help 2076 Allocate PLTs when loading modules so that jumps and calls whose 2077 targets are too far away for their relative offsets to be encoded 2078 in the instructions themselves can be bounced via veneers in the 2079 module's PLT. This allows modules to be allocated in the generic 2080 vmalloc area after the dedicated module memory area has been 2081 exhausted. 2082 2083 When running with address space randomization (KASLR), the module 2084 region itself may be too far away for ordinary relative jumps and 2085 calls, and so in that case, module PLTs are required and cannot be 2086 disabled. 2087 2088 Specific errata workaround(s) might also force module PLTs to be 2089 enabled (ARM64_ERRATUM_843419). 2090 2091config ARM64_PSEUDO_NMI 2092 bool "Support for NMI-like interrupts" 2093 select ARM_GIC_V3 2094 help 2095 Adds support for mimicking Non-Maskable Interrupts through the use of 2096 GIC interrupt priority. This support requires version 3 or later of 2097 ARM GIC. 2098 2099 This high priority configuration for interrupts needs to be 2100 explicitly enabled by setting the kernel parameter 2101 "irqchip.gicv3_pseudo_nmi" to 1. 2102 2103 If unsure, say N 2104 2105if ARM64_PSEUDO_NMI 2106config ARM64_DEBUG_PRIORITY_MASKING 2107 bool "Debug interrupt priority masking" 2108 help 2109 This adds runtime checks to functions enabling/disabling 2110 interrupts when using priority masking. The additional checks verify 2111 the validity of ICC_PMR_EL1 when calling concerned functions. 2112 2113 If unsure, say N 2114endif # ARM64_PSEUDO_NMI 2115 2116config RELOCATABLE 2117 bool "Build a relocatable kernel image" if EXPERT 2118 select ARCH_HAS_RELR 2119 default y 2120 help 2121 This builds the kernel as a Position Independent Executable (PIE), 2122 which retains all relocation metadata required to relocate the 2123 kernel binary at runtime to a different virtual address than the 2124 address it was linked at. 2125 Since AArch64 uses the RELA relocation format, this requires a 2126 relocation pass at runtime even if the kernel is loaded at the 2127 same address it was linked at. 2128 2129config RANDOMIZE_BASE 2130 bool "Randomize the address of the kernel image" 2131 select ARM64_MODULE_PLTS if MODULES 2132 select RELOCATABLE 2133 help 2134 Randomizes the virtual address at which the kernel image is 2135 loaded, as a security feature that deters exploit attempts 2136 relying on knowledge of the location of kernel internals. 2137 2138 It is the bootloader's job to provide entropy, by passing a 2139 random u64 value in /chosen/kaslr-seed at kernel entry. 2140 2141 When booting via the UEFI stub, it will invoke the firmware's 2142 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2143 to the kernel proper. In addition, it will randomise the physical 2144 location of the kernel Image as well. 2145 2146 If unsure, say N. 2147 2148config RANDOMIZE_MODULE_REGION_FULL 2149 bool "Randomize the module region over a 2 GB range" 2150 depends on RANDOMIZE_BASE 2151 default y 2152 help 2153 Randomizes the location of the module region inside a 2 GB window 2154 covering the core kernel. This way, it is less likely for modules 2155 to leak information about the location of core kernel data structures 2156 but it does imply that function calls between modules and the core 2157 kernel will need to be resolved via veneers in the module PLT. 2158 2159 When this option is not set, the module region will be randomized over 2160 a limited range that contains the [_stext, _etext] interval of the 2161 core kernel, so branch relocations are almost always in range unless 2162 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2163 particular case of region exhaustion, modules might be able to fall 2164 back to a larger 2GB area. 2165 2166config CC_HAVE_STACKPROTECTOR_SYSREG 2167 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2168 2169config STACKPROTECTOR_PER_TASK 2170 def_bool y 2171 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2172 2173config UNWIND_PATCH_PAC_INTO_SCS 2174 bool "Enable shadow call stack dynamically using code patching" 2175 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2176 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2177 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2178 depends on SHADOW_CALL_STACK 2179 select UNWIND_TABLES 2180 select DYNAMIC_SCS 2181 2182endmenu # "Kernel Features" 2183 2184menu "Boot options" 2185 2186config ARM64_ACPI_PARKING_PROTOCOL 2187 bool "Enable support for the ARM64 ACPI parking protocol" 2188 depends on ACPI 2189 help 2190 Enable support for the ARM64 ACPI parking protocol. If disabled 2191 the kernel will not allow booting through the ARM64 ACPI parking 2192 protocol even if the corresponding data is present in the ACPI 2193 MADT table. 2194 2195config CMDLINE 2196 string "Default kernel command string" 2197 default "" 2198 help 2199 Provide a set of default command-line options at build time by 2200 entering them here. As a minimum, you should specify the the 2201 root device (e.g. root=/dev/nfs). 2202 2203choice 2204 prompt "Kernel command line type" if CMDLINE != "" 2205 default CMDLINE_FROM_BOOTLOADER 2206 help 2207 Choose how the kernel will handle the provided default kernel 2208 command line string. 2209 2210config CMDLINE_FROM_BOOTLOADER 2211 bool "Use bootloader kernel arguments if available" 2212 help 2213 Uses the command-line options passed by the boot loader. If 2214 the boot loader doesn't provide any, the default kernel command 2215 string provided in CMDLINE will be used. 2216 2217config CMDLINE_FORCE 2218 bool "Always use the default kernel command string" 2219 help 2220 Always use the default kernel command string, even if the boot 2221 loader passes other arguments to the kernel. 2222 This is useful if you cannot or don't want to change the 2223 command-line options your boot loader passes to the kernel. 2224 2225endchoice 2226 2227config EFI_STUB 2228 bool 2229 2230config EFI 2231 bool "UEFI runtime support" 2232 depends on OF && !CPU_BIG_ENDIAN 2233 depends on KERNEL_MODE_NEON 2234 select ARCH_SUPPORTS_ACPI 2235 select LIBFDT 2236 select UCS2_STRING 2237 select EFI_PARAMS_FROM_FDT 2238 select EFI_RUNTIME_WRAPPERS 2239 select EFI_STUB 2240 select EFI_GENERIC_STUB 2241 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2242 default y 2243 help 2244 This option provides support for runtime services provided 2245 by UEFI firmware (such as non-volatile variables, realtime 2246 clock, and platform reset). A UEFI stub is also provided to 2247 allow the kernel to be booted as an EFI application. This 2248 is only useful on systems that have UEFI firmware. 2249 2250config DMI 2251 bool "Enable support for SMBIOS (DMI) tables" 2252 depends on EFI 2253 default y 2254 help 2255 This enables SMBIOS/DMI feature for systems. 2256 2257 This option is only useful on systems that have UEFI firmware. 2258 However, even with this option, the resultant kernel should 2259 continue to boot on existing non-UEFI platforms. 2260 2261endmenu # "Boot options" 2262 2263menu "Power management options" 2264 2265source "kernel/power/Kconfig" 2266 2267config ARCH_HIBERNATION_POSSIBLE 2268 def_bool y 2269 depends on CPU_PM 2270 2271config ARCH_HIBERNATION_HEADER 2272 def_bool y 2273 depends on HIBERNATION 2274 2275config ARCH_SUSPEND_POSSIBLE 2276 def_bool y 2277 2278endmenu # "Power management options" 2279 2280menu "CPU Power Management" 2281 2282source "drivers/cpuidle/Kconfig" 2283 2284source "drivers/cpufreq/Kconfig" 2285 2286endmenu # "CPU Power Management" 2287 2288source "drivers/acpi/Kconfig" 2289 2290source "arch/arm64/kvm/Kconfig" 2291 2292