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_SUPPORTS_PER_VMA_LOCK 99 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 100 select ARCH_WANT_DEFAULT_BPF_JIT 101 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 102 select ARCH_WANT_FRAME_POINTERS 103 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 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_BOUNCE_UNALIGNED_KMALLOC 124 select DMA_DIRECT_REMAP 125 select EDAC_SUPPORT 126 select FRAME_POINTER 127 select FUNCTION_ALIGNMENT_4B 128 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 129 select GENERIC_ALLOCATOR 130 select GENERIC_ARCH_TOPOLOGY 131 select GENERIC_CLOCKEVENTS_BROADCAST 132 select GENERIC_CPU_AUTOPROBE 133 select GENERIC_CPU_VULNERABILITIES 134 select GENERIC_EARLY_IOREMAP 135 select GENERIC_IDLE_POLL_SETUP 136 select GENERIC_IOREMAP 137 select GENERIC_IRQ_IPI 138 select GENERIC_IRQ_PROBE 139 select GENERIC_IRQ_SHOW 140 select GENERIC_IRQ_SHOW_LEVEL 141 select GENERIC_LIB_DEVMEM_IS_ALLOWED 142 select GENERIC_PCI_IOMAP 143 select GENERIC_PTDUMP 144 select GENERIC_SCHED_CLOCK 145 select GENERIC_SMP_IDLE_THREAD 146 select GENERIC_TIME_VSYSCALL 147 select GENERIC_GETTIMEOFDAY 148 select GENERIC_VDSO_TIME_NS 149 select HARDIRQS_SW_RESEND 150 select HAS_IOPORT 151 select HAVE_MOVE_PMD 152 select HAVE_MOVE_PUD 153 select HAVE_PCI 154 select HAVE_ACPI_APEI if (ACPI && EFI) 155 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 156 select HAVE_ARCH_AUDITSYSCALL 157 select HAVE_ARCH_BITREVERSE 158 select HAVE_ARCH_COMPILER_H 159 select HAVE_ARCH_HUGE_VMALLOC 160 select HAVE_ARCH_HUGE_VMAP 161 select HAVE_ARCH_JUMP_LABEL 162 select HAVE_ARCH_JUMP_LABEL_RELATIVE 163 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 164 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 165 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 166 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 167 # Some instrumentation may be unsound, hence EXPERT 168 select HAVE_ARCH_KCSAN if EXPERT 169 select HAVE_ARCH_KFENCE 170 select HAVE_ARCH_KGDB 171 select HAVE_ARCH_MMAP_RND_BITS 172 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 173 select HAVE_ARCH_PREL32_RELOCATIONS 174 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 175 select HAVE_ARCH_SECCOMP_FILTER 176 select HAVE_ARCH_STACKLEAK 177 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 178 select HAVE_ARCH_TRACEHOOK 179 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 180 select HAVE_ARCH_VMAP_STACK 181 select HAVE_ARM_SMCCC 182 select HAVE_ASM_MODVERSIONS 183 select HAVE_EBPF_JIT 184 select HAVE_C_RECORDMCOUNT 185 select HAVE_CMPXCHG_DOUBLE 186 select HAVE_CMPXCHG_LOCAL 187 select HAVE_CONTEXT_TRACKING_USER 188 select HAVE_DEBUG_KMEMLEAK 189 select HAVE_DMA_CONTIGUOUS 190 select HAVE_DYNAMIC_FTRACE 191 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 192 if $(cc-option,-fpatchable-function-entry=2) 193 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 194 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 195 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 196 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 197 !CC_OPTIMIZE_FOR_SIZE) 198 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 199 if DYNAMIC_FTRACE_WITH_ARGS 200 select HAVE_EFFICIENT_UNALIGNED_ACCESS 201 select HAVE_FAST_GUP 202 select HAVE_FTRACE_MCOUNT_RECORD 203 select HAVE_FUNCTION_TRACER 204 select HAVE_FUNCTION_ERROR_INJECTION 205 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 206 select HAVE_FUNCTION_GRAPH_TRACER 207 select HAVE_GCC_PLUGINS 208 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 209 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 210 select HAVE_HW_BREAKPOINT if PERF_EVENTS 211 select HAVE_IOREMAP_PROT 212 select HAVE_IRQ_TIME_ACCOUNTING 213 select HAVE_KVM 214 select HAVE_MOD_ARCH_SPECIFIC 215 select HAVE_NMI 216 select HAVE_PERF_EVENTS 217 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 218 select HAVE_PERF_REGS 219 select HAVE_PERF_USER_STACK_DUMP 220 select HAVE_PREEMPT_DYNAMIC_KEY 221 select HAVE_REGS_AND_STACK_ACCESS_API 222 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 223 select HAVE_FUNCTION_ARG_ACCESS_API 224 select MMU_GATHER_RCU_TABLE_FREE 225 select HAVE_RSEQ 226 select HAVE_STACKPROTECTOR 227 select HAVE_SYSCALL_TRACEPOINTS 228 select HAVE_KPROBES 229 select HAVE_KRETPROBES 230 select HAVE_GENERIC_VDSO 231 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 232 select IRQ_DOMAIN 233 select IRQ_FORCED_THREADING 234 select KASAN_VMALLOC if KASAN 235 select LOCK_MM_AND_FIND_VMA 236 select MODULES_USE_ELF_RELA 237 select NEED_DMA_MAP_STATE 238 select NEED_SG_DMA_LENGTH 239 select OF 240 select OF_EARLY_FLATTREE 241 select PCI_DOMAINS_GENERIC if PCI 242 select PCI_ECAM if (ACPI && PCI) 243 select PCI_SYSCALL if PCI 244 select POWER_RESET 245 select POWER_SUPPLY 246 select SPARSE_IRQ 247 select SWIOTLB 248 select SYSCTL_EXCEPTION_TRACE 249 select THREAD_INFO_IN_TASK 250 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 251 select TRACE_IRQFLAGS_SUPPORT 252 select TRACE_IRQFLAGS_NMI_SUPPORT 253 select HAVE_SOFTIRQ_ON_OWN_STACK 254 help 255 ARM 64-bit (AArch64) Linux support. 256 257config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 258 def_bool CC_IS_CLANG 259 # https://github.com/ClangBuiltLinux/linux/issues/1507 260 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 261 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 262 263config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 264 def_bool CC_IS_GCC 265 depends on $(cc-option,-fpatchable-function-entry=2) 266 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 267 268config 64BIT 269 def_bool y 270 271config MMU 272 def_bool y 273 274config ARM64_PAGE_SHIFT 275 int 276 default 16 if ARM64_64K_PAGES 277 default 14 if ARM64_16K_PAGES 278 default 12 279 280config ARM64_CONT_PTE_SHIFT 281 int 282 default 5 if ARM64_64K_PAGES 283 default 7 if ARM64_16K_PAGES 284 default 4 285 286config ARM64_CONT_PMD_SHIFT 287 int 288 default 5 if ARM64_64K_PAGES 289 default 5 if ARM64_16K_PAGES 290 default 4 291 292config ARCH_MMAP_RND_BITS_MIN 293 default 14 if ARM64_64K_PAGES 294 default 16 if ARM64_16K_PAGES 295 default 18 296 297# max bits determined by the following formula: 298# VA_BITS - PAGE_SHIFT - 3 299config ARCH_MMAP_RND_BITS_MAX 300 default 19 if ARM64_VA_BITS=36 301 default 24 if ARM64_VA_BITS=39 302 default 27 if ARM64_VA_BITS=42 303 default 30 if ARM64_VA_BITS=47 304 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 305 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 306 default 33 if ARM64_VA_BITS=48 307 default 14 if ARM64_64K_PAGES 308 default 16 if ARM64_16K_PAGES 309 default 18 310 311config ARCH_MMAP_RND_COMPAT_BITS_MIN 312 default 7 if ARM64_64K_PAGES 313 default 9 if ARM64_16K_PAGES 314 default 11 315 316config ARCH_MMAP_RND_COMPAT_BITS_MAX 317 default 16 318 319config NO_IOPORT_MAP 320 def_bool y if !PCI 321 322config STACKTRACE_SUPPORT 323 def_bool y 324 325config ILLEGAL_POINTER_VALUE 326 hex 327 default 0xdead000000000000 328 329config LOCKDEP_SUPPORT 330 def_bool y 331 332config GENERIC_BUG 333 def_bool y 334 depends on BUG 335 336config GENERIC_BUG_RELATIVE_POINTERS 337 def_bool y 338 depends on GENERIC_BUG 339 340config GENERIC_HWEIGHT 341 def_bool y 342 343config GENERIC_CSUM 344 def_bool y 345 346config GENERIC_CALIBRATE_DELAY 347 def_bool y 348 349config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 350 def_bool y 351 352config SMP 353 def_bool y 354 355config KERNEL_MODE_NEON 356 def_bool y 357 358config FIX_EARLYCON_MEM 359 def_bool y 360 361config PGTABLE_LEVELS 362 int 363 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 364 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 365 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 366 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 367 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 368 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 369 370config ARCH_SUPPORTS_UPROBES 371 def_bool y 372 373config ARCH_PROC_KCORE_TEXT 374 def_bool y 375 376config BROKEN_GAS_INST 377 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 378 379config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 380 bool 381 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 382 # https://reviews.llvm.org/D75044 383 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 384 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 385 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 386 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 387 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 388 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 389 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 390 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 391 default n 392 393config KASAN_SHADOW_OFFSET 394 hex 395 depends on KASAN_GENERIC || KASAN_SW_TAGS 396 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 397 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 398 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 399 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 400 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 401 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 402 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 403 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 404 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 405 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 406 default 0xffffffffffffffff 407 408config UNWIND_TABLES 409 bool 410 411source "arch/arm64/Kconfig.platforms" 412 413menu "Kernel Features" 414 415menu "ARM errata workarounds via the alternatives framework" 416 417config ARM64_WORKAROUND_CLEAN_CACHE 418 bool 419 420config ARM64_ERRATUM_826319 421 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 422 default y 423 select ARM64_WORKAROUND_CLEAN_CACHE 424 help 425 This option adds an alternative code sequence to work around ARM 426 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 427 AXI master interface and an L2 cache. 428 429 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 430 and is unable to accept a certain write via this interface, it will 431 not progress on read data presented on the read data channel and the 432 system can deadlock. 433 434 The workaround promotes data cache clean instructions to 435 data cache clean-and-invalidate. 436 Please note that this does not necessarily enable the workaround, 437 as it depends on the alternative framework, which will only patch 438 the kernel if an affected CPU is detected. 439 440 If unsure, say Y. 441 442config ARM64_ERRATUM_827319 443 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 444 default y 445 select ARM64_WORKAROUND_CLEAN_CACHE 446 help 447 This option adds an alternative code sequence to work around ARM 448 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 449 master interface and an L2 cache. 450 451 Under certain conditions this erratum can cause a clean line eviction 452 to occur at the same time as another transaction to the same address 453 on the AMBA 5 CHI interface, which can cause data corruption if the 454 interconnect reorders the two transactions. 455 456 The workaround promotes data cache clean instructions to 457 data cache clean-and-invalidate. 458 Please note that this does not necessarily enable the workaround, 459 as it depends on the alternative framework, which will only patch 460 the kernel if an affected CPU is detected. 461 462 If unsure, say Y. 463 464config ARM64_ERRATUM_824069 465 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 466 default y 467 select ARM64_WORKAROUND_CLEAN_CACHE 468 help 469 This option adds an alternative code sequence to work around ARM 470 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 471 to a coherent interconnect. 472 473 If a Cortex-A53 processor is executing a store or prefetch for 474 write instruction at the same time as a processor in another 475 cluster is executing a cache maintenance operation to the same 476 address, then this erratum might cause a clean cache line to be 477 incorrectly marked as dirty. 478 479 The workaround promotes data cache clean instructions to 480 data cache clean-and-invalidate. 481 Please note that this option does not necessarily enable the 482 workaround, as it depends on the alternative framework, which will 483 only patch the kernel if an affected CPU is detected. 484 485 If unsure, say Y. 486 487config ARM64_ERRATUM_819472 488 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 489 default y 490 select ARM64_WORKAROUND_CLEAN_CACHE 491 help 492 This option adds an alternative code sequence to work around ARM 493 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 494 present when it is connected to a coherent interconnect. 495 496 If the processor is executing a load and store exclusive sequence at 497 the same time as a processor in another cluster is executing a cache 498 maintenance operation to the same address, then this erratum might 499 cause data corruption. 500 501 The workaround promotes data cache clean instructions to 502 data cache clean-and-invalidate. 503 Please note that this does not necessarily enable the workaround, 504 as it depends on the alternative framework, which will only patch 505 the kernel if an affected CPU is detected. 506 507 If unsure, say Y. 508 509config ARM64_ERRATUM_832075 510 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 511 default y 512 help 513 This option adds an alternative code sequence to work around ARM 514 erratum 832075 on Cortex-A57 parts up to r1p2. 515 516 Affected Cortex-A57 parts might deadlock when exclusive load/store 517 instructions to Write-Back memory are mixed with Device loads. 518 519 The workaround is to promote device loads to use Load-Acquire 520 semantics. 521 Please note that this does not necessarily enable the workaround, 522 as it depends on the alternative framework, which will only patch 523 the kernel if an affected CPU is detected. 524 525 If unsure, say Y. 526 527config ARM64_ERRATUM_834220 528 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 529 depends on KVM 530 default y 531 help 532 This option adds an alternative code sequence to work around ARM 533 erratum 834220 on Cortex-A57 parts up to r1p2. 534 535 Affected Cortex-A57 parts might report a Stage 2 translation 536 fault as the result of a Stage 1 fault for load crossing a 537 page boundary when there is a permission or device memory 538 alignment fault at Stage 1 and a translation fault at Stage 2. 539 540 The workaround is to verify that the Stage 1 translation 541 doesn't generate a fault before handling the Stage 2 fault. 542 Please note that this does not necessarily enable the workaround, 543 as it depends on the alternative framework, which will only patch 544 the kernel if an affected CPU is detected. 545 546 If unsure, say Y. 547 548config ARM64_ERRATUM_1742098 549 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 550 depends on COMPAT 551 default y 552 help 553 This option removes the AES hwcap for aarch32 user-space to 554 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 555 556 Affected parts may corrupt the AES state if an interrupt is 557 taken between a pair of AES instructions. These instructions 558 are only present if the cryptography extensions are present. 559 All software should have a fallback implementation for CPUs 560 that don't implement the cryptography extensions. 561 562 If unsure, say Y. 563 564config ARM64_ERRATUM_845719 565 bool "Cortex-A53: 845719: a load might read incorrect data" 566 depends on COMPAT 567 default y 568 help 569 This option adds an alternative code sequence to work around ARM 570 erratum 845719 on Cortex-A53 parts up to r0p4. 571 572 When running a compat (AArch32) userspace on an affected Cortex-A53 573 part, a load at EL0 from a virtual address that matches the bottom 32 574 bits of the virtual address used by a recent load at (AArch64) EL1 575 might return incorrect data. 576 577 The workaround is to write the contextidr_el1 register on exception 578 return to a 32-bit task. 579 Please note that this does not necessarily enable the workaround, 580 as it depends on the alternative framework, which will only patch 581 the kernel if an affected CPU is detected. 582 583 If unsure, say Y. 584 585config ARM64_ERRATUM_843419 586 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 587 default y 588 help 589 This option links the kernel with '--fix-cortex-a53-843419' and 590 enables PLT support to replace certain ADRP instructions, which can 591 cause subsequent memory accesses to use an incorrect address on 592 Cortex-A53 parts up to r0p4. 593 594 If unsure, say Y. 595 596config ARM64_LD_HAS_FIX_ERRATUM_843419 597 def_bool $(ld-option,--fix-cortex-a53-843419) 598 599config ARM64_ERRATUM_1024718 600 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 601 default y 602 help 603 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 604 605 Affected Cortex-A55 cores (all revisions) could cause incorrect 606 update of the hardware dirty bit when the DBM/AP bits are updated 607 without a break-before-make. The workaround is to disable the usage 608 of hardware DBM locally on the affected cores. CPUs not affected by 609 this erratum will continue to use the feature. 610 611 If unsure, say Y. 612 613config ARM64_ERRATUM_1418040 614 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 615 default y 616 depends on COMPAT 617 help 618 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 619 errata 1188873 and 1418040. 620 621 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 622 cause register corruption when accessing the timer registers 623 from AArch32 userspace. 624 625 If unsure, say Y. 626 627config ARM64_WORKAROUND_SPECULATIVE_AT 628 bool 629 630config ARM64_ERRATUM_1165522 631 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 632 default y 633 select ARM64_WORKAROUND_SPECULATIVE_AT 634 help 635 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 636 637 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 638 corrupted TLBs by speculating an AT instruction during a guest 639 context switch. 640 641 If unsure, say Y. 642 643config ARM64_ERRATUM_1319367 644 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 645 default y 646 select ARM64_WORKAROUND_SPECULATIVE_AT 647 help 648 This option adds work arounds for ARM Cortex-A57 erratum 1319537 649 and A72 erratum 1319367 650 651 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 652 speculating an AT instruction during a guest context switch. 653 654 If unsure, say Y. 655 656config ARM64_ERRATUM_1530923 657 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 658 default y 659 select ARM64_WORKAROUND_SPECULATIVE_AT 660 help 661 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 662 663 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 664 corrupted TLBs by speculating an AT instruction during a guest 665 context switch. 666 667 If unsure, say Y. 668 669config ARM64_WORKAROUND_REPEAT_TLBI 670 bool 671 672config ARM64_ERRATUM_2441007 673 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 674 default y 675 select ARM64_WORKAROUND_REPEAT_TLBI 676 help 677 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 678 679 Under very rare circumstances, affected Cortex-A55 CPUs 680 may not handle a race between a break-before-make sequence on one 681 CPU, and another CPU accessing the same page. This could allow a 682 store to a page that has been unmapped. 683 684 Work around this by adding the affected CPUs to the list that needs 685 TLB sequences to be done twice. 686 687 If unsure, say Y. 688 689config ARM64_ERRATUM_1286807 690 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 691 default y 692 select ARM64_WORKAROUND_REPEAT_TLBI 693 help 694 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 695 696 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 697 address for a cacheable mapping of a location is being 698 accessed by a core while another core is remapping the virtual 699 address to a new physical page using the recommended 700 break-before-make sequence, then under very rare circumstances 701 TLBI+DSB completes before a read using the translation being 702 invalidated has been observed by other observers. The 703 workaround repeats the TLBI+DSB operation. 704 705config ARM64_ERRATUM_1463225 706 bool "Cortex-A76: Software Step might prevent interrupt recognition" 707 default y 708 help 709 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 710 711 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 712 of a system call instruction (SVC) can prevent recognition of 713 subsequent interrupts when software stepping is disabled in the 714 exception handler of the system call and either kernel debugging 715 is enabled or VHE is in use. 716 717 Work around the erratum by triggering a dummy step exception 718 when handling a system call from a task that is being stepped 719 in a VHE configuration of the kernel. 720 721 If unsure, say Y. 722 723config ARM64_ERRATUM_1542419 724 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 725 default y 726 help 727 This option adds a workaround for ARM Neoverse-N1 erratum 728 1542419. 729 730 Affected Neoverse-N1 cores could execute a stale instruction when 731 modified by another CPU. The workaround depends on a firmware 732 counterpart. 733 734 Workaround the issue by hiding the DIC feature from EL0. This 735 forces user-space to perform cache maintenance. 736 737 If unsure, say Y. 738 739config ARM64_ERRATUM_1508412 740 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 741 default y 742 help 743 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 744 745 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 746 of a store-exclusive or read of PAR_EL1 and a load with device or 747 non-cacheable memory attributes. The workaround depends on a firmware 748 counterpart. 749 750 KVM guests must also have the workaround implemented or they can 751 deadlock the system. 752 753 Work around the issue by inserting DMB SY barriers around PAR_EL1 754 register reads and warning KVM users. The DMB barrier is sufficient 755 to prevent a speculative PAR_EL1 read. 756 757 If unsure, say Y. 758 759config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 760 bool 761 762config ARM64_ERRATUM_2051678 763 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 764 default y 765 help 766 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 767 Affected Cortex-A510 might not respect the ordering rules for 768 hardware update of the page table's dirty bit. The workaround 769 is to not enable the feature on affected CPUs. 770 771 If unsure, say Y. 772 773config ARM64_ERRATUM_2077057 774 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 775 default y 776 help 777 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 778 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 779 expected, but a Pointer Authentication trap is taken instead. The 780 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 781 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 782 783 This can only happen when EL2 is stepping EL1. 784 785 When these conditions occur, the SPSR_EL2 value is unchanged from the 786 previous guest entry, and can be restored from the in-memory copy. 787 788 If unsure, say Y. 789 790config ARM64_ERRATUM_2658417 791 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 792 default y 793 help 794 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 795 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 796 BFMMLA or VMMLA instructions in rare circumstances when a pair of 797 A510 CPUs are using shared neon hardware. As the sharing is not 798 discoverable by the kernel, hide the BF16 HWCAP to indicate that 799 user-space should not be using these instructions. 800 801 If unsure, say Y. 802 803config ARM64_ERRATUM_2119858 804 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 805 default y 806 depends on CORESIGHT_TRBE 807 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 808 help 809 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 810 811 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 812 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 813 the event of a WRAP event. 814 815 Work around the issue by always making sure we move the TRBPTR_EL1 by 816 256 bytes before enabling the buffer and filling the first 256 bytes of 817 the buffer with ETM ignore packets upon disabling. 818 819 If unsure, say Y. 820 821config ARM64_ERRATUM_2139208 822 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 823 default y 824 depends on CORESIGHT_TRBE 825 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 826 help 827 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 828 829 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 830 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 831 the event of a WRAP event. 832 833 Work around the issue by always making sure we move the TRBPTR_EL1 by 834 256 bytes before enabling the buffer and filling the first 256 bytes of 835 the buffer with ETM ignore packets upon disabling. 836 837 If unsure, say Y. 838 839config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 840 bool 841 842config ARM64_ERRATUM_2054223 843 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 844 default y 845 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 846 help 847 Enable workaround for ARM Cortex-A710 erratum 2054223 848 849 Affected cores may fail to flush the trace data on a TSB instruction, when 850 the PE is in trace prohibited state. This will cause losing a few bytes 851 of the trace cached. 852 853 Workaround is to issue two TSB consecutively on affected cores. 854 855 If unsure, say Y. 856 857config ARM64_ERRATUM_2067961 858 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 859 default y 860 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 861 help 862 Enable workaround for ARM Neoverse-N2 erratum 2067961 863 864 Affected cores may fail to flush the trace data on a TSB instruction, when 865 the PE is in trace prohibited state. This will cause losing a few bytes 866 of the trace cached. 867 868 Workaround is to issue two TSB consecutively on affected cores. 869 870 If unsure, say Y. 871 872config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 873 bool 874 875config ARM64_ERRATUM_2253138 876 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 877 depends on CORESIGHT_TRBE 878 default y 879 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 880 help 881 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 882 883 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 884 for TRBE. Under some conditions, the TRBE might generate a write to the next 885 virtually addressed page following the last page of the TRBE address space 886 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 887 888 Work around this in the driver by always making sure that there is a 889 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 890 891 If unsure, say Y. 892 893config ARM64_ERRATUM_2224489 894 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 895 depends on CORESIGHT_TRBE 896 default y 897 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 898 help 899 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 900 901 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 902 for TRBE. Under some conditions, the TRBE might generate a write to the next 903 virtually addressed page following the last page of the TRBE address space 904 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 905 906 Work around this in the driver by always making sure that there is a 907 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 908 909 If unsure, say Y. 910 911config ARM64_ERRATUM_2441009 912 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 913 default y 914 select ARM64_WORKAROUND_REPEAT_TLBI 915 help 916 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 917 918 Under very rare circumstances, affected Cortex-A510 CPUs 919 may not handle a race between a break-before-make sequence on one 920 CPU, and another CPU accessing the same page. This could allow a 921 store to a page that has been unmapped. 922 923 Work around this by adding the affected CPUs to the list that needs 924 TLB sequences to be done twice. 925 926 If unsure, say Y. 927 928config ARM64_ERRATUM_2064142 929 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 930 depends on CORESIGHT_TRBE 931 default y 932 help 933 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 934 935 Affected Cortex-A510 core might fail to write into system registers after the 936 TRBE has been disabled. Under some conditions after the TRBE has been disabled 937 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 938 and TRBTRG_EL1 will be ignored and will not be effected. 939 940 Work around this in the driver by executing TSB CSYNC and DSB after collection 941 is stopped and before performing a system register write to one of the affected 942 registers. 943 944 If unsure, say Y. 945 946config ARM64_ERRATUM_2038923 947 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 948 depends on CORESIGHT_TRBE 949 default y 950 help 951 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 952 953 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 954 prohibited within the CPU. As a result, the trace buffer or trace buffer state 955 might be corrupted. This happens after TRBE buffer has been enabled by setting 956 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 957 execution changes from a context, in which trace is prohibited to one where it 958 isn't, or vice versa. In these mentioned conditions, the view of whether trace 959 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 960 the trace buffer state might be corrupted. 961 962 Work around this in the driver by preventing an inconsistent view of whether the 963 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 964 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 965 two ISB instructions if no ERET is to take place. 966 967 If unsure, say Y. 968 969config ARM64_ERRATUM_1902691 970 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 971 depends on CORESIGHT_TRBE 972 default y 973 help 974 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 975 976 Affected Cortex-A510 core might cause trace data corruption, when being written 977 into the memory. Effectively TRBE is broken and hence cannot be used to capture 978 trace data. 979 980 Work around this problem in the driver by just preventing TRBE initialization on 981 affected cpus. The firmware must have disabled the access to TRBE for the kernel 982 on such implementations. This will cover the kernel for any firmware that doesn't 983 do this already. 984 985 If unsure, say Y. 986 987config ARM64_ERRATUM_2457168 988 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 989 depends on ARM64_AMU_EXTN 990 default y 991 help 992 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 993 994 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 995 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 996 incorrectly giving a significantly higher output value. 997 998 Work around this problem by returning 0 when reading the affected counter in 999 key locations that results in disabling all users of this counter. This effect 1000 is the same to firmware disabling affected counters. 1001 1002 If unsure, say Y. 1003 1004config ARM64_ERRATUM_2645198 1005 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1006 default y 1007 help 1008 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1009 1010 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1011 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1012 next instruction abort caused by permission fault. 1013 1014 Only user-space does executable to non-executable permission transition via 1015 mprotect() system call. Workaround the problem by doing a break-before-make 1016 TLB invalidation, for all changes to executable user space mappings. 1017 1018 If unsure, say Y. 1019 1020config CAVIUM_ERRATUM_22375 1021 bool "Cavium erratum 22375, 24313" 1022 default y 1023 help 1024 Enable workaround for errata 22375 and 24313. 1025 1026 This implements two gicv3-its errata workarounds for ThunderX. Both 1027 with a small impact affecting only ITS table allocation. 1028 1029 erratum 22375: only alloc 8MB table size 1030 erratum 24313: ignore memory access type 1031 1032 The fixes are in ITS initialization and basically ignore memory access 1033 type and table size provided by the TYPER and BASER registers. 1034 1035 If unsure, say Y. 1036 1037config CAVIUM_ERRATUM_23144 1038 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1039 depends on NUMA 1040 default y 1041 help 1042 ITS SYNC command hang for cross node io and collections/cpu mapping. 1043 1044 If unsure, say Y. 1045 1046config CAVIUM_ERRATUM_23154 1047 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1048 default y 1049 help 1050 The ThunderX GICv3 implementation requires a modified version for 1051 reading the IAR status to ensure data synchronization 1052 (access to icc_iar1_el1 is not sync'ed before and after). 1053 1054 It also suffers from erratum 38545 (also present on Marvell's 1055 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1056 spuriously presented to the CPU interface. 1057 1058 If unsure, say Y. 1059 1060config CAVIUM_ERRATUM_27456 1061 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1062 default y 1063 help 1064 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1065 instructions may cause the icache to become corrupted if it 1066 contains data for a non-current ASID. The fix is to 1067 invalidate the icache when changing the mm context. 1068 1069 If unsure, say Y. 1070 1071config CAVIUM_ERRATUM_30115 1072 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1073 default y 1074 help 1075 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1076 1.2, and T83 Pass 1.0, KVM guest execution may disable 1077 interrupts in host. Trapping both GICv3 group-0 and group-1 1078 accesses sidesteps the issue. 1079 1080 If unsure, say Y. 1081 1082config CAVIUM_TX2_ERRATUM_219 1083 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1084 default y 1085 help 1086 On Cavium ThunderX2, a load, store or prefetch instruction between a 1087 TTBR update and the corresponding context synchronizing operation can 1088 cause a spurious Data Abort to be delivered to any hardware thread in 1089 the CPU core. 1090 1091 Work around the issue by avoiding the problematic code sequence and 1092 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1093 trap handler performs the corresponding register access, skips the 1094 instruction and ensures context synchronization by virtue of the 1095 exception return. 1096 1097 If unsure, say Y. 1098 1099config FUJITSU_ERRATUM_010001 1100 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1101 default y 1102 help 1103 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1104 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1105 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1106 This fault occurs under a specific hardware condition when a 1107 load/store instruction performs an address translation using: 1108 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1109 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1110 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1111 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1112 1113 The workaround is to ensure these bits are clear in TCR_ELx. 1114 The workaround only affects the Fujitsu-A64FX. 1115 1116 If unsure, say Y. 1117 1118config HISILICON_ERRATUM_161600802 1119 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1120 default y 1121 help 1122 The HiSilicon Hip07 SoC uses the wrong redistributor base 1123 when issued ITS commands such as VMOVP and VMAPP, and requires 1124 a 128kB offset to be applied to the target address in this commands. 1125 1126 If unsure, say Y. 1127 1128config QCOM_FALKOR_ERRATUM_1003 1129 bool "Falkor E1003: Incorrect translation due to ASID change" 1130 default y 1131 help 1132 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1133 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1134 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1135 then only for entries in the walk cache, since the leaf translation 1136 is unchanged. Work around the erratum by invalidating the walk cache 1137 entries for the trampoline before entering the kernel proper. 1138 1139config QCOM_FALKOR_ERRATUM_1009 1140 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1141 default y 1142 select ARM64_WORKAROUND_REPEAT_TLBI 1143 help 1144 On Falkor v1, the CPU may prematurely complete a DSB following a 1145 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1146 one more time to fix the issue. 1147 1148 If unsure, say Y. 1149 1150config QCOM_QDF2400_ERRATUM_0065 1151 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1152 default y 1153 help 1154 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1155 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1156 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1157 1158 If unsure, say Y. 1159 1160config QCOM_FALKOR_ERRATUM_E1041 1161 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1162 default y 1163 help 1164 Falkor CPU may speculatively fetch instructions from an improper 1165 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1166 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1167 1168 If unsure, say Y. 1169 1170config NVIDIA_CARMEL_CNP_ERRATUM 1171 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1172 default y 1173 help 1174 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1175 invalidate shared TLB entries installed by a different core, as it would 1176 on standard ARM cores. 1177 1178 If unsure, say Y. 1179 1180config ROCKCHIP_ERRATUM_3588001 1181 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1182 default y 1183 help 1184 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1185 This means, that its sharability feature may not be used, even though it 1186 is supported by the IP itself. 1187 1188 If unsure, say Y. 1189 1190config SOCIONEXT_SYNQUACER_PREITS 1191 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1192 default y 1193 help 1194 Socionext Synquacer SoCs implement a separate h/w block to generate 1195 MSI doorbell writes with non-zero values for the device ID. 1196 1197 If unsure, say Y. 1198 1199endmenu # "ARM errata workarounds via the alternatives framework" 1200 1201choice 1202 prompt "Page size" 1203 default ARM64_4K_PAGES 1204 help 1205 Page size (translation granule) configuration. 1206 1207config ARM64_4K_PAGES 1208 bool "4KB" 1209 help 1210 This feature enables 4KB pages support. 1211 1212config ARM64_16K_PAGES 1213 bool "16KB" 1214 help 1215 The system will use 16KB pages support. AArch32 emulation 1216 requires applications compiled with 16K (or a multiple of 16K) 1217 aligned segments. 1218 1219config ARM64_64K_PAGES 1220 bool "64KB" 1221 help 1222 This feature enables 64KB pages support (4KB by default) 1223 allowing only two levels of page tables and faster TLB 1224 look-up. AArch32 emulation requires applications compiled 1225 with 64K aligned segments. 1226 1227endchoice 1228 1229choice 1230 prompt "Virtual address space size" 1231 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1232 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1233 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1234 help 1235 Allows choosing one of multiple possible virtual address 1236 space sizes. The level of translation table is determined by 1237 a combination of page size and virtual address space size. 1238 1239config ARM64_VA_BITS_36 1240 bool "36-bit" if EXPERT 1241 depends on ARM64_16K_PAGES 1242 1243config ARM64_VA_BITS_39 1244 bool "39-bit" 1245 depends on ARM64_4K_PAGES 1246 1247config ARM64_VA_BITS_42 1248 bool "42-bit" 1249 depends on ARM64_64K_PAGES 1250 1251config ARM64_VA_BITS_47 1252 bool "47-bit" 1253 depends on ARM64_16K_PAGES 1254 1255config ARM64_VA_BITS_48 1256 bool "48-bit" 1257 1258config ARM64_VA_BITS_52 1259 bool "52-bit" 1260 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1261 help 1262 Enable 52-bit virtual addressing for userspace when explicitly 1263 requested via a hint to mmap(). The kernel will also use 52-bit 1264 virtual addresses for its own mappings (provided HW support for 1265 this feature is available, otherwise it reverts to 48-bit). 1266 1267 NOTE: Enabling 52-bit virtual addressing in conjunction with 1268 ARMv8.3 Pointer Authentication will result in the PAC being 1269 reduced from 7 bits to 3 bits, which may have a significant 1270 impact on its susceptibility to brute-force attacks. 1271 1272 If unsure, select 48-bit virtual addressing instead. 1273 1274endchoice 1275 1276config ARM64_FORCE_52BIT 1277 bool "Force 52-bit virtual addresses for userspace" 1278 depends on ARM64_VA_BITS_52 && EXPERT 1279 help 1280 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1281 to maintain compatibility with older software by providing 48-bit VAs 1282 unless a hint is supplied to mmap. 1283 1284 This configuration option disables the 48-bit compatibility logic, and 1285 forces all userspace addresses to be 52-bit on HW that supports it. One 1286 should only enable this configuration option for stress testing userspace 1287 memory management code. If unsure say N here. 1288 1289config ARM64_VA_BITS 1290 int 1291 default 36 if ARM64_VA_BITS_36 1292 default 39 if ARM64_VA_BITS_39 1293 default 42 if ARM64_VA_BITS_42 1294 default 47 if ARM64_VA_BITS_47 1295 default 48 if ARM64_VA_BITS_48 1296 default 52 if ARM64_VA_BITS_52 1297 1298choice 1299 prompt "Physical address space size" 1300 default ARM64_PA_BITS_48 1301 help 1302 Choose the maximum physical address range that the kernel will 1303 support. 1304 1305config ARM64_PA_BITS_48 1306 bool "48-bit" 1307 1308config ARM64_PA_BITS_52 1309 bool "52-bit (ARMv8.2)" 1310 depends on ARM64_64K_PAGES 1311 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1312 help 1313 Enable support for a 52-bit physical address space, introduced as 1314 part of the ARMv8.2-LPA extension. 1315 1316 With this enabled, the kernel will also continue to work on CPUs that 1317 do not support ARMv8.2-LPA, but with some added memory overhead (and 1318 minor performance overhead). 1319 1320endchoice 1321 1322config ARM64_PA_BITS 1323 int 1324 default 48 if ARM64_PA_BITS_48 1325 default 52 if ARM64_PA_BITS_52 1326 1327choice 1328 prompt "Endianness" 1329 default CPU_LITTLE_ENDIAN 1330 help 1331 Select the endianness of data accesses performed by the CPU. Userspace 1332 applications will need to be compiled and linked for the endianness 1333 that is selected here. 1334 1335config CPU_BIG_ENDIAN 1336 bool "Build big-endian kernel" 1337 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1338 help 1339 Say Y if you plan on running a kernel with a big-endian userspace. 1340 1341config CPU_LITTLE_ENDIAN 1342 bool "Build little-endian kernel" 1343 help 1344 Say Y if you plan on running a kernel with a little-endian userspace. 1345 This is usually the case for distributions targeting arm64. 1346 1347endchoice 1348 1349config SCHED_MC 1350 bool "Multi-core scheduler support" 1351 help 1352 Multi-core scheduler support improves the CPU scheduler's decision 1353 making when dealing with multi-core CPU chips at a cost of slightly 1354 increased overhead in some places. If unsure say N here. 1355 1356config SCHED_CLUSTER 1357 bool "Cluster scheduler support" 1358 help 1359 Cluster scheduler support improves the CPU scheduler's decision 1360 making when dealing with machines that have clusters of CPUs. 1361 Cluster usually means a couple of CPUs which are placed closely 1362 by sharing mid-level caches, last-level cache tags or internal 1363 busses. 1364 1365config SCHED_SMT 1366 bool "SMT scheduler support" 1367 help 1368 Improves the CPU scheduler's decision making when dealing with 1369 MultiThreading at a cost of slightly increased overhead in some 1370 places. If unsure say N here. 1371 1372config NR_CPUS 1373 int "Maximum number of CPUs (2-4096)" 1374 range 2 4096 1375 default "256" 1376 1377config HOTPLUG_CPU 1378 bool "Support for hot-pluggable CPUs" 1379 select GENERIC_IRQ_MIGRATION 1380 help 1381 Say Y here to experiment with turning CPUs off and on. CPUs 1382 can be controlled through /sys/devices/system/cpu. 1383 1384# Common NUMA Features 1385config NUMA 1386 bool "NUMA Memory Allocation and Scheduler Support" 1387 select GENERIC_ARCH_NUMA 1388 select ACPI_NUMA if ACPI 1389 select OF_NUMA 1390 select HAVE_SETUP_PER_CPU_AREA 1391 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1392 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1393 select USE_PERCPU_NUMA_NODE_ID 1394 help 1395 Enable NUMA (Non-Uniform Memory Access) support. 1396 1397 The kernel will try to allocate memory used by a CPU on the 1398 local memory of the CPU and add some more 1399 NUMA awareness to the kernel. 1400 1401config NODES_SHIFT 1402 int "Maximum NUMA Nodes (as a power of 2)" 1403 range 1 10 1404 default "4" 1405 depends on NUMA 1406 help 1407 Specify the maximum number of NUMA Nodes available on the target 1408 system. Increases memory reserved to accommodate various tables. 1409 1410source "kernel/Kconfig.hz" 1411 1412config ARCH_SPARSEMEM_ENABLE 1413 def_bool y 1414 select SPARSEMEM_VMEMMAP_ENABLE 1415 select SPARSEMEM_VMEMMAP 1416 1417config HW_PERF_EVENTS 1418 def_bool y 1419 depends on ARM_PMU 1420 1421# Supported by clang >= 7.0 or GCC >= 12.0.0 1422config CC_HAVE_SHADOW_CALL_STACK 1423 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1424 1425config PARAVIRT 1426 bool "Enable paravirtualization code" 1427 help 1428 This changes the kernel so it can modify itself when it is run 1429 under a hypervisor, potentially improving performance significantly 1430 over full virtualization. 1431 1432config PARAVIRT_TIME_ACCOUNTING 1433 bool "Paravirtual steal time accounting" 1434 select PARAVIRT 1435 help 1436 Select this option to enable fine granularity task steal time 1437 accounting. Time spent executing other tasks in parallel with 1438 the current vCPU is discounted from the vCPU power. To account for 1439 that, there can be a small performance impact. 1440 1441 If in doubt, say N here. 1442 1443config KEXEC 1444 depends on PM_SLEEP_SMP 1445 select KEXEC_CORE 1446 bool "kexec system call" 1447 help 1448 kexec is a system call that implements the ability to shutdown your 1449 current kernel, and to start another kernel. It is like a reboot 1450 but it is independent of the system firmware. And like a reboot 1451 you can start any kernel with it, not just Linux. 1452 1453config KEXEC_FILE 1454 bool "kexec file based system call" 1455 select KEXEC_CORE 1456 select HAVE_IMA_KEXEC if IMA 1457 help 1458 This is new version of kexec system call. This system call is 1459 file based and takes file descriptors as system call argument 1460 for kernel and initramfs as opposed to list of segments as 1461 accepted by previous system call. 1462 1463config KEXEC_SIG 1464 bool "Verify kernel signature during kexec_file_load() syscall" 1465 depends on KEXEC_FILE 1466 help 1467 Select this option to verify a signature with loaded kernel 1468 image. If configured, any attempt of loading a image without 1469 valid signature will fail. 1470 1471 In addition to that option, you need to enable signature 1472 verification for the corresponding kernel image type being 1473 loaded in order for this to work. 1474 1475config KEXEC_IMAGE_VERIFY_SIG 1476 bool "Enable Image signature verification support" 1477 default y 1478 depends on KEXEC_SIG 1479 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1480 help 1481 Enable Image signature verification support. 1482 1483comment "Support for PE file signature verification disabled" 1484 depends on KEXEC_SIG 1485 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1486 1487config CRASH_DUMP 1488 bool "Build kdump crash kernel" 1489 help 1490 Generate crash dump after being started by kexec. This should 1491 be normally only set in special crash dump kernels which are 1492 loaded in the main kernel with kexec-tools into a specially 1493 reserved region and then later executed after a crash by 1494 kdump/kexec. 1495 1496 For more details see Documentation/admin-guide/kdump/kdump.rst 1497 1498config TRANS_TABLE 1499 def_bool y 1500 depends on HIBERNATION || KEXEC_CORE 1501 1502config XEN_DOM0 1503 def_bool y 1504 depends on XEN 1505 1506config XEN 1507 bool "Xen guest support on ARM64" 1508 depends on ARM64 && OF 1509 select SWIOTLB_XEN 1510 select PARAVIRT 1511 help 1512 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1513 1514# include/linux/mmzone.h requires the following to be true: 1515# 1516# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1517# 1518# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1519# 1520# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1521# ----+-------------------+--------------+-----------------+--------------------+ 1522# 4K | 27 | 12 | 15 | 10 | 1523# 16K | 27 | 14 | 13 | 11 | 1524# 64K | 29 | 16 | 13 | 13 | 1525config ARCH_FORCE_MAX_ORDER 1526 int 1527 default "13" if ARM64_64K_PAGES 1528 default "11" if ARM64_16K_PAGES 1529 default "10" 1530 help 1531 The kernel page allocator limits the size of maximal physically 1532 contiguous allocations. The limit is called MAX_ORDER and it 1533 defines the maximal power of two of number of pages that can be 1534 allocated as a single contiguous block. This option allows 1535 overriding the default setting when ability to allocate very 1536 large blocks of physically contiguous memory is required. 1537 1538 The maximal size of allocation cannot exceed the size of the 1539 section, so the value of MAX_ORDER should satisfy 1540 1541 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1542 1543 Don't change if unsure. 1544 1545config UNMAP_KERNEL_AT_EL0 1546 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1547 default y 1548 help 1549 Speculation attacks against some high-performance processors can 1550 be used to bypass MMU permission checks and leak kernel data to 1551 userspace. This can be defended against by unmapping the kernel 1552 when running in userspace, mapping it back in on exception entry 1553 via a trampoline page in the vector table. 1554 1555 If unsure, say Y. 1556 1557config MITIGATE_SPECTRE_BRANCH_HISTORY 1558 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1559 default y 1560 help 1561 Speculation attacks against some high-performance processors can 1562 make use of branch history to influence future speculation. 1563 When taking an exception from user-space, a sequence of branches 1564 or a firmware call overwrites the branch history. 1565 1566config RODATA_FULL_DEFAULT_ENABLED 1567 bool "Apply r/o permissions of VM areas also to their linear aliases" 1568 default y 1569 help 1570 Apply read-only attributes of VM areas to the linear alias of 1571 the backing pages as well. This prevents code or read-only data 1572 from being modified (inadvertently or intentionally) via another 1573 mapping of the same memory page. This additional enhancement can 1574 be turned off at runtime by passing rodata=[off|on] (and turned on 1575 with rodata=full if this option is set to 'n') 1576 1577 This requires the linear region to be mapped down to pages, 1578 which may adversely affect performance in some cases. 1579 1580config ARM64_SW_TTBR0_PAN 1581 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1582 help 1583 Enabling this option prevents the kernel from accessing 1584 user-space memory directly by pointing TTBR0_EL1 to a reserved 1585 zeroed area and reserved ASID. The user access routines 1586 restore the valid TTBR0_EL1 temporarily. 1587 1588config ARM64_TAGGED_ADDR_ABI 1589 bool "Enable the tagged user addresses syscall ABI" 1590 default y 1591 help 1592 When this option is enabled, user applications can opt in to a 1593 relaxed ABI via prctl() allowing tagged addresses to be passed 1594 to system calls as pointer arguments. For details, see 1595 Documentation/arch/arm64/tagged-address-abi.rst. 1596 1597menuconfig COMPAT 1598 bool "Kernel support for 32-bit EL0" 1599 depends on ARM64_4K_PAGES || EXPERT 1600 select HAVE_UID16 1601 select OLD_SIGSUSPEND3 1602 select COMPAT_OLD_SIGACTION 1603 help 1604 This option enables support for a 32-bit EL0 running under a 64-bit 1605 kernel at EL1. AArch32-specific components such as system calls, 1606 the user helper functions, VFP support and the ptrace interface are 1607 handled appropriately by the kernel. 1608 1609 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1610 that you will only be able to execute AArch32 binaries that were compiled 1611 with page size aligned segments. 1612 1613 If you want to execute 32-bit userspace applications, say Y. 1614 1615if COMPAT 1616 1617config KUSER_HELPERS 1618 bool "Enable kuser helpers page for 32-bit applications" 1619 default y 1620 help 1621 Warning: disabling this option may break 32-bit user programs. 1622 1623 Provide kuser helpers to compat tasks. The kernel provides 1624 helper code to userspace in read only form at a fixed location 1625 to allow userspace to be independent of the CPU type fitted to 1626 the system. This permits binaries to be run on ARMv4 through 1627 to ARMv8 without modification. 1628 1629 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1630 1631 However, the fixed address nature of these helpers can be used 1632 by ROP (return orientated programming) authors when creating 1633 exploits. 1634 1635 If all of the binaries and libraries which run on your platform 1636 are built specifically for your platform, and make no use of 1637 these helpers, then you can turn this option off to hinder 1638 such exploits. However, in that case, if a binary or library 1639 relying on those helpers is run, it will not function correctly. 1640 1641 Say N here only if you are absolutely certain that you do not 1642 need these helpers; otherwise, the safe option is to say Y. 1643 1644config COMPAT_VDSO 1645 bool "Enable vDSO for 32-bit applications" 1646 depends on !CPU_BIG_ENDIAN 1647 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1648 select GENERIC_COMPAT_VDSO 1649 default y 1650 help 1651 Place in the process address space of 32-bit applications an 1652 ELF shared object providing fast implementations of gettimeofday 1653 and clock_gettime. 1654 1655 You must have a 32-bit build of glibc 2.22 or later for programs 1656 to seamlessly take advantage of this. 1657 1658config THUMB2_COMPAT_VDSO 1659 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1660 depends on COMPAT_VDSO 1661 default y 1662 help 1663 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1664 otherwise with '-marm'. 1665 1666config COMPAT_ALIGNMENT_FIXUPS 1667 bool "Fix up misaligned multi-word loads and stores in user space" 1668 1669menuconfig ARMV8_DEPRECATED 1670 bool "Emulate deprecated/obsolete ARMv8 instructions" 1671 depends on SYSCTL 1672 help 1673 Legacy software support may require certain instructions 1674 that have been deprecated or obsoleted in the architecture. 1675 1676 Enable this config to enable selective emulation of these 1677 features. 1678 1679 If unsure, say Y 1680 1681if ARMV8_DEPRECATED 1682 1683config SWP_EMULATION 1684 bool "Emulate SWP/SWPB instructions" 1685 help 1686 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1687 they are always undefined. Say Y here to enable software 1688 emulation of these instructions for userspace using LDXR/STXR. 1689 This feature can be controlled at runtime with the abi.swp 1690 sysctl which is disabled by default. 1691 1692 In some older versions of glibc [<=2.8] SWP is used during futex 1693 trylock() operations with the assumption that the code will not 1694 be preempted. This invalid assumption may be more likely to fail 1695 with SWP emulation enabled, leading to deadlock of the user 1696 application. 1697 1698 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1699 on an external transaction monitoring block called a global 1700 monitor to maintain update atomicity. If your system does not 1701 implement a global monitor, this option can cause programs that 1702 perform SWP operations to uncached memory to deadlock. 1703 1704 If unsure, say Y 1705 1706config CP15_BARRIER_EMULATION 1707 bool "Emulate CP15 Barrier instructions" 1708 help 1709 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1710 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1711 strongly recommended to use the ISB, DSB, and DMB 1712 instructions instead. 1713 1714 Say Y here to enable software emulation of these 1715 instructions for AArch32 userspace code. When this option is 1716 enabled, CP15 barrier usage is traced which can help 1717 identify software that needs updating. This feature can be 1718 controlled at runtime with the abi.cp15_barrier sysctl. 1719 1720 If unsure, say Y 1721 1722config SETEND_EMULATION 1723 bool "Emulate SETEND instruction" 1724 help 1725 The SETEND instruction alters the data-endianness of the 1726 AArch32 EL0, and is deprecated in ARMv8. 1727 1728 Say Y here to enable software emulation of the instruction 1729 for AArch32 userspace code. This feature can be controlled 1730 at runtime with the abi.setend sysctl. 1731 1732 Note: All the cpus on the system must have mixed endian support at EL0 1733 for this feature to be enabled. If a new CPU - which doesn't support mixed 1734 endian - is hotplugged in after this feature has been enabled, there could 1735 be unexpected results in the applications. 1736 1737 If unsure, say Y 1738endif # ARMV8_DEPRECATED 1739 1740endif # COMPAT 1741 1742menu "ARMv8.1 architectural features" 1743 1744config ARM64_HW_AFDBM 1745 bool "Support for hardware updates of the Access and Dirty page flags" 1746 default y 1747 help 1748 The ARMv8.1 architecture extensions introduce support for 1749 hardware updates of the access and dirty information in page 1750 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1751 capable processors, accesses to pages with PTE_AF cleared will 1752 set this bit instead of raising an access flag fault. 1753 Similarly, writes to read-only pages with the DBM bit set will 1754 clear the read-only bit (AP[2]) instead of raising a 1755 permission fault. 1756 1757 Kernels built with this configuration option enabled continue 1758 to work on pre-ARMv8.1 hardware and the performance impact is 1759 minimal. If unsure, say Y. 1760 1761config ARM64_PAN 1762 bool "Enable support for Privileged Access Never (PAN)" 1763 default y 1764 help 1765 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1766 prevents the kernel or hypervisor from accessing user-space (EL0) 1767 memory directly. 1768 1769 Choosing this option will cause any unprotected (not using 1770 copy_to_user et al) memory access to fail with a permission fault. 1771 1772 The feature is detected at runtime, and will remain as a 'nop' 1773 instruction if the cpu does not implement the feature. 1774 1775config AS_HAS_LDAPR 1776 def_bool $(as-instr,.arch_extension rcpc) 1777 1778config AS_HAS_LSE_ATOMICS 1779 def_bool $(as-instr,.arch_extension lse) 1780 1781config ARM64_LSE_ATOMICS 1782 bool 1783 default ARM64_USE_LSE_ATOMICS 1784 depends on AS_HAS_LSE_ATOMICS 1785 1786config ARM64_USE_LSE_ATOMICS 1787 bool "Atomic instructions" 1788 default y 1789 help 1790 As part of the Large System Extensions, ARMv8.1 introduces new 1791 atomic instructions that are designed specifically to scale in 1792 very large systems. 1793 1794 Say Y here to make use of these instructions for the in-kernel 1795 atomic routines. This incurs a small overhead on CPUs that do 1796 not support these instructions and requires the kernel to be 1797 built with binutils >= 2.25 in order for the new instructions 1798 to be used. 1799 1800endmenu # "ARMv8.1 architectural features" 1801 1802menu "ARMv8.2 architectural features" 1803 1804config AS_HAS_ARMV8_2 1805 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1806 1807config AS_HAS_SHA3 1808 def_bool $(as-instr,.arch armv8.2-a+sha3) 1809 1810config ARM64_PMEM 1811 bool "Enable support for persistent memory" 1812 select ARCH_HAS_PMEM_API 1813 select ARCH_HAS_UACCESS_FLUSHCACHE 1814 help 1815 Say Y to enable support for the persistent memory API based on the 1816 ARMv8.2 DCPoP feature. 1817 1818 The feature is detected at runtime, and the kernel will use DC CVAC 1819 operations if DC CVAP is not supported (following the behaviour of 1820 DC CVAP itself if the system does not define a point of persistence). 1821 1822config ARM64_RAS_EXTN 1823 bool "Enable support for RAS CPU Extensions" 1824 default y 1825 help 1826 CPUs that support the Reliability, Availability and Serviceability 1827 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1828 errors, classify them and report them to software. 1829 1830 On CPUs with these extensions system software can use additional 1831 barriers to determine if faults are pending and read the 1832 classification from a new set of registers. 1833 1834 Selecting this feature will allow the kernel to use these barriers 1835 and access the new registers if the system supports the extension. 1836 Platform RAS features may additionally depend on firmware support. 1837 1838config ARM64_CNP 1839 bool "Enable support for Common Not Private (CNP) translations" 1840 default y 1841 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1842 help 1843 Common Not Private (CNP) allows translation table entries to 1844 be shared between different PEs in the same inner shareable 1845 domain, so the hardware can use this fact to optimise the 1846 caching of such entries in the TLB. 1847 1848 Selecting this option allows the CNP feature to be detected 1849 at runtime, and does not affect PEs that do not implement 1850 this feature. 1851 1852endmenu # "ARMv8.2 architectural features" 1853 1854menu "ARMv8.3 architectural features" 1855 1856config ARM64_PTR_AUTH 1857 bool "Enable support for pointer authentication" 1858 default y 1859 help 1860 Pointer authentication (part of the ARMv8.3 Extensions) provides 1861 instructions for signing and authenticating pointers against secret 1862 keys, which can be used to mitigate Return Oriented Programming (ROP) 1863 and other attacks. 1864 1865 This option enables these instructions at EL0 (i.e. for userspace). 1866 Choosing this option will cause the kernel to initialise secret keys 1867 for each process at exec() time, with these keys being 1868 context-switched along with the process. 1869 1870 The feature is detected at runtime. If the feature is not present in 1871 hardware it will not be advertised to userspace/KVM guest nor will it 1872 be enabled. 1873 1874 If the feature is present on the boot CPU but not on a late CPU, then 1875 the late CPU will be parked. Also, if the boot CPU does not have 1876 address auth and the late CPU has then the late CPU will still boot 1877 but with the feature disabled. On such a system, this option should 1878 not be selected. 1879 1880config ARM64_PTR_AUTH_KERNEL 1881 bool "Use pointer authentication for kernel" 1882 default y 1883 depends on ARM64_PTR_AUTH 1884 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1885 # Modern compilers insert a .note.gnu.property section note for PAC 1886 # which is only understood by binutils starting with version 2.33.1. 1887 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1888 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1889 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1890 help 1891 If the compiler supports the -mbranch-protection or 1892 -msign-return-address flag (e.g. GCC 7 or later), then this option 1893 will cause the kernel itself to be compiled with return address 1894 protection. In this case, and if the target hardware is known to 1895 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1896 disabled with minimal loss of protection. 1897 1898 This feature works with FUNCTION_GRAPH_TRACER option only if 1899 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1900 1901config CC_HAS_BRANCH_PROT_PAC_RET 1902 # GCC 9 or later, clang 8 or later 1903 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1904 1905config CC_HAS_SIGN_RETURN_ADDRESS 1906 # GCC 7, 8 1907 def_bool $(cc-option,-msign-return-address=all) 1908 1909config AS_HAS_ARMV8_3 1910 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1911 1912config AS_HAS_CFI_NEGATE_RA_STATE 1913 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1914 1915endmenu # "ARMv8.3 architectural features" 1916 1917menu "ARMv8.4 architectural features" 1918 1919config ARM64_AMU_EXTN 1920 bool "Enable support for the Activity Monitors Unit CPU extension" 1921 default y 1922 help 1923 The activity monitors extension is an optional extension introduced 1924 by the ARMv8.4 CPU architecture. This enables support for version 1 1925 of the activity monitors architecture, AMUv1. 1926 1927 To enable the use of this extension on CPUs that implement it, say Y. 1928 1929 Note that for architectural reasons, firmware _must_ implement AMU 1930 support when running on CPUs that present the activity monitors 1931 extension. The required support is present in: 1932 * Version 1.5 and later of the ARM Trusted Firmware 1933 1934 For kernels that have this configuration enabled but boot with broken 1935 firmware, you may need to say N here until the firmware is fixed. 1936 Otherwise you may experience firmware panics or lockups when 1937 accessing the counter registers. Even if you are not observing these 1938 symptoms, the values returned by the register reads might not 1939 correctly reflect reality. Most commonly, the value read will be 0, 1940 indicating that the counter is not enabled. 1941 1942config AS_HAS_ARMV8_4 1943 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1944 1945config ARM64_TLB_RANGE 1946 bool "Enable support for tlbi range feature" 1947 default y 1948 depends on AS_HAS_ARMV8_4 1949 help 1950 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1951 range of input addresses. 1952 1953 The feature introduces new assembly instructions, and they were 1954 support when binutils >= 2.30. 1955 1956endmenu # "ARMv8.4 architectural features" 1957 1958menu "ARMv8.5 architectural features" 1959 1960config AS_HAS_ARMV8_5 1961 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1962 1963config ARM64_BTI 1964 bool "Branch Target Identification support" 1965 default y 1966 help 1967 Branch Target Identification (part of the ARMv8.5 Extensions) 1968 provides a mechanism to limit the set of locations to which computed 1969 branch instructions such as BR or BLR can jump. 1970 1971 To make use of BTI on CPUs that support it, say Y. 1972 1973 BTI is intended to provide complementary protection to other control 1974 flow integrity protection mechanisms, such as the Pointer 1975 authentication mechanism provided as part of the ARMv8.3 Extensions. 1976 For this reason, it does not make sense to enable this option without 1977 also enabling support for pointer authentication. Thus, when 1978 enabling this option you should also select ARM64_PTR_AUTH=y. 1979 1980 Userspace binaries must also be specifically compiled to make use of 1981 this mechanism. If you say N here or the hardware does not support 1982 BTI, such binaries can still run, but you get no additional 1983 enforcement of branch destinations. 1984 1985config ARM64_BTI_KERNEL 1986 bool "Use Branch Target Identification for kernel" 1987 default y 1988 depends on ARM64_BTI 1989 depends on ARM64_PTR_AUTH_KERNEL 1990 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1991 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1992 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1993 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1994 depends on !CC_IS_GCC 1995 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1996 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1997 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1998 help 1999 Build the kernel with Branch Target Identification annotations 2000 and enable enforcement of this for kernel code. When this option 2001 is enabled and the system supports BTI all kernel code including 2002 modular code must have BTI enabled. 2003 2004config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2005 # GCC 9 or later, clang 8 or later 2006 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2007 2008config ARM64_E0PD 2009 bool "Enable support for E0PD" 2010 default y 2011 help 2012 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2013 that EL0 accesses made via TTBR1 always fault in constant time, 2014 providing similar benefits to KASLR as those provided by KPTI, but 2015 with lower overhead and without disrupting legitimate access to 2016 kernel memory such as SPE. 2017 2018 This option enables E0PD for TTBR1 where available. 2019 2020config ARM64_AS_HAS_MTE 2021 # Initial support for MTE went in binutils 2.32.0, checked with 2022 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2023 # as a late addition to the final architecture spec (LDGM/STGM) 2024 # is only supported in the newer 2.32.x and 2.33 binutils 2025 # versions, hence the extra "stgm" instruction check below. 2026 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2027 2028config ARM64_MTE 2029 bool "Memory Tagging Extension support" 2030 default y 2031 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2032 depends on AS_HAS_ARMV8_5 2033 depends on AS_HAS_LSE_ATOMICS 2034 # Required for tag checking in the uaccess routines 2035 depends on ARM64_PAN 2036 select ARCH_HAS_SUBPAGE_FAULTS 2037 select ARCH_USES_HIGH_VMA_FLAGS 2038 select ARCH_USES_PG_ARCH_X 2039 help 2040 Memory Tagging (part of the ARMv8.5 Extensions) provides 2041 architectural support for run-time, always-on detection of 2042 various classes of memory error to aid with software debugging 2043 to eliminate vulnerabilities arising from memory-unsafe 2044 languages. 2045 2046 This option enables the support for the Memory Tagging 2047 Extension at EL0 (i.e. for userspace). 2048 2049 Selecting this option allows the feature to be detected at 2050 runtime. Any secondary CPU not implementing this feature will 2051 not be allowed a late bring-up. 2052 2053 Userspace binaries that want to use this feature must 2054 explicitly opt in. The mechanism for the userspace is 2055 described in: 2056 2057 Documentation/arch/arm64/memory-tagging-extension.rst. 2058 2059endmenu # "ARMv8.5 architectural features" 2060 2061menu "ARMv8.7 architectural features" 2062 2063config ARM64_EPAN 2064 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2065 default y 2066 depends on ARM64_PAN 2067 help 2068 Enhanced Privileged Access Never (EPAN) allows Privileged 2069 Access Never to be used with Execute-only mappings. 2070 2071 The feature is detected at runtime, and will remain disabled 2072 if the cpu does not implement the feature. 2073endmenu # "ARMv8.7 architectural features" 2074 2075config ARM64_SVE 2076 bool "ARM Scalable Vector Extension support" 2077 default y 2078 help 2079 The Scalable Vector Extension (SVE) is an extension to the AArch64 2080 execution state which complements and extends the SIMD functionality 2081 of the base architecture to support much larger vectors and to enable 2082 additional vectorisation opportunities. 2083 2084 To enable use of this extension on CPUs that implement it, say Y. 2085 2086 On CPUs that support the SVE2 extensions, this option will enable 2087 those too. 2088 2089 Note that for architectural reasons, firmware _must_ implement SVE 2090 support when running on SVE capable hardware. The required support 2091 is present in: 2092 2093 * version 1.5 and later of the ARM Trusted Firmware 2094 * the AArch64 boot wrapper since commit 5e1261e08abf 2095 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2096 2097 For other firmware implementations, consult the firmware documentation 2098 or vendor. 2099 2100 If you need the kernel to boot on SVE-capable hardware with broken 2101 firmware, you may need to say N here until you get your firmware 2102 fixed. Otherwise, you may experience firmware panics or lockups when 2103 booting the kernel. If unsure and you are not observing these 2104 symptoms, you should assume that it is safe to say Y. 2105 2106config ARM64_SME 2107 bool "ARM Scalable Matrix Extension support" 2108 default y 2109 depends on ARM64_SVE 2110 help 2111 The Scalable Matrix Extension (SME) is an extension to the AArch64 2112 execution state which utilises a substantial subset of the SVE 2113 instruction set, together with the addition of new architectural 2114 register state capable of holding two dimensional matrix tiles to 2115 enable various matrix operations. 2116 2117config ARM64_PSEUDO_NMI 2118 bool "Support for NMI-like interrupts" 2119 select ARM_GIC_V3 2120 help 2121 Adds support for mimicking Non-Maskable Interrupts through the use of 2122 GIC interrupt priority. This support requires version 3 or later of 2123 ARM GIC. 2124 2125 This high priority configuration for interrupts needs to be 2126 explicitly enabled by setting the kernel parameter 2127 "irqchip.gicv3_pseudo_nmi" to 1. 2128 2129 If unsure, say N 2130 2131if ARM64_PSEUDO_NMI 2132config ARM64_DEBUG_PRIORITY_MASKING 2133 bool "Debug interrupt priority masking" 2134 help 2135 This adds runtime checks to functions enabling/disabling 2136 interrupts when using priority masking. The additional checks verify 2137 the validity of ICC_PMR_EL1 when calling concerned functions. 2138 2139 If unsure, say N 2140endif # ARM64_PSEUDO_NMI 2141 2142config RELOCATABLE 2143 bool "Build a relocatable kernel image" if EXPERT 2144 select ARCH_HAS_RELR 2145 default y 2146 help 2147 This builds the kernel as a Position Independent Executable (PIE), 2148 which retains all relocation metadata required to relocate the 2149 kernel binary at runtime to a different virtual address than the 2150 address it was linked at. 2151 Since AArch64 uses the RELA relocation format, this requires a 2152 relocation pass at runtime even if the kernel is loaded at the 2153 same address it was linked at. 2154 2155config RANDOMIZE_BASE 2156 bool "Randomize the address of the kernel image" 2157 select RELOCATABLE 2158 help 2159 Randomizes the virtual address at which the kernel image is 2160 loaded, as a security feature that deters exploit attempts 2161 relying on knowledge of the location of kernel internals. 2162 2163 It is the bootloader's job to provide entropy, by passing a 2164 random u64 value in /chosen/kaslr-seed at kernel entry. 2165 2166 When booting via the UEFI stub, it will invoke the firmware's 2167 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2168 to the kernel proper. In addition, it will randomise the physical 2169 location of the kernel Image as well. 2170 2171 If unsure, say N. 2172 2173config RANDOMIZE_MODULE_REGION_FULL 2174 bool "Randomize the module region over a 2 GB range" 2175 depends on RANDOMIZE_BASE 2176 default y 2177 help 2178 Randomizes the location of the module region inside a 2 GB window 2179 covering the core kernel. This way, it is less likely for modules 2180 to leak information about the location of core kernel data structures 2181 but it does imply that function calls between modules and the core 2182 kernel will need to be resolved via veneers in the module PLT. 2183 2184 When this option is not set, the module region will be randomized over 2185 a limited range that contains the [_stext, _etext] interval of the 2186 core kernel, so branch relocations are almost always in range unless 2187 the region is exhausted. In this particular case of region 2188 exhaustion, modules might be able to fall back to a larger 2GB area. 2189 2190config CC_HAVE_STACKPROTECTOR_SYSREG 2191 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2192 2193config STACKPROTECTOR_PER_TASK 2194 def_bool y 2195 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2196 2197config UNWIND_PATCH_PAC_INTO_SCS 2198 bool "Enable shadow call stack dynamically using code patching" 2199 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2200 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2201 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2202 depends on SHADOW_CALL_STACK 2203 select UNWIND_TABLES 2204 select DYNAMIC_SCS 2205 2206endmenu # "Kernel Features" 2207 2208menu "Boot options" 2209 2210config ARM64_ACPI_PARKING_PROTOCOL 2211 bool "Enable support for the ARM64 ACPI parking protocol" 2212 depends on ACPI 2213 help 2214 Enable support for the ARM64 ACPI parking protocol. If disabled 2215 the kernel will not allow booting through the ARM64 ACPI parking 2216 protocol even if the corresponding data is present in the ACPI 2217 MADT table. 2218 2219config CMDLINE 2220 string "Default kernel command string" 2221 default "" 2222 help 2223 Provide a set of default command-line options at build time by 2224 entering them here. As a minimum, you should specify the the 2225 root device (e.g. root=/dev/nfs). 2226 2227choice 2228 prompt "Kernel command line type" if CMDLINE != "" 2229 default CMDLINE_FROM_BOOTLOADER 2230 help 2231 Choose how the kernel will handle the provided default kernel 2232 command line string. 2233 2234config CMDLINE_FROM_BOOTLOADER 2235 bool "Use bootloader kernel arguments if available" 2236 help 2237 Uses the command-line options passed by the boot loader. If 2238 the boot loader doesn't provide any, the default kernel command 2239 string provided in CMDLINE will be used. 2240 2241config CMDLINE_FORCE 2242 bool "Always use the default kernel command string" 2243 help 2244 Always use the default kernel command string, even if the boot 2245 loader passes other arguments to the kernel. 2246 This is useful if you cannot or don't want to change the 2247 command-line options your boot loader passes to the kernel. 2248 2249endchoice 2250 2251config EFI_STUB 2252 bool 2253 2254config EFI 2255 bool "UEFI runtime support" 2256 depends on OF && !CPU_BIG_ENDIAN 2257 depends on KERNEL_MODE_NEON 2258 select ARCH_SUPPORTS_ACPI 2259 select LIBFDT 2260 select UCS2_STRING 2261 select EFI_PARAMS_FROM_FDT 2262 select EFI_RUNTIME_WRAPPERS 2263 select EFI_STUB 2264 select EFI_GENERIC_STUB 2265 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2266 default y 2267 help 2268 This option provides support for runtime services provided 2269 by UEFI firmware (such as non-volatile variables, realtime 2270 clock, and platform reset). A UEFI stub is also provided to 2271 allow the kernel to be booted as an EFI application. This 2272 is only useful on systems that have UEFI firmware. 2273 2274config DMI 2275 bool "Enable support for SMBIOS (DMI) tables" 2276 depends on EFI 2277 default y 2278 help 2279 This enables SMBIOS/DMI feature for systems. 2280 2281 This option is only useful on systems that have UEFI firmware. 2282 However, even with this option, the resultant kernel should 2283 continue to boot on existing non-UEFI platforms. 2284 2285endmenu # "Boot options" 2286 2287menu "Power management options" 2288 2289source "kernel/power/Kconfig" 2290 2291config ARCH_HIBERNATION_POSSIBLE 2292 def_bool y 2293 depends on CPU_PM 2294 2295config ARCH_HIBERNATION_HEADER 2296 def_bool y 2297 depends on HIBERNATION 2298 2299config ARCH_SUSPEND_POSSIBLE 2300 def_bool y 2301 2302endmenu # "Power management options" 2303 2304menu "CPU Power Management" 2305 2306source "drivers/cpuidle/Kconfig" 2307 2308source "drivers/cpufreq/Kconfig" 2309 2310endmenu # "CPU Power Management" 2311 2312source "drivers/acpi/Kconfig" 2313 2314source "arch/arm64/kvm/Kconfig" 2315 2316