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_MHP_MEMMAP_ON_MEMORY_ENABLE 82 select ARCH_USE_CMPXCHG_LOCKREF 83 select ARCH_USE_GNU_PROPERTY 84 select ARCH_USE_MEMTEST 85 select ARCH_USE_QUEUED_RWLOCKS 86 select ARCH_USE_QUEUED_SPINLOCKS 87 select ARCH_USE_SYM_ANNOTATIONS 88 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 89 select ARCH_SUPPORTS_HUGETLBFS 90 select ARCH_SUPPORTS_MEMORY_FAILURE 91 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 92 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 93 select ARCH_SUPPORTS_LTO_CLANG_THIN 94 select ARCH_SUPPORTS_CFI_CLANG 95 select ARCH_SUPPORTS_ATOMIC_RMW 96 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 97 select ARCH_SUPPORTS_NUMA_BALANCING 98 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 99 select ARCH_SUPPORTS_PER_VMA_LOCK 100 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 101 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 102 select ARCH_WANT_DEFAULT_BPF_JIT 103 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 104 select ARCH_WANT_FRAME_POINTERS 105 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 106 select ARCH_WANT_LD_ORPHAN_WARN 107 select ARCH_WANTS_NO_INSTR 108 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 109 select ARCH_HAS_UBSAN_SANITIZE_ALL 110 select ARM_AMBA 111 select ARM_ARCH_TIMER 112 select ARM_GIC 113 select AUDIT_ARCH_COMPAT_GENERIC 114 select ARM_GIC_V2M if PCI 115 select ARM_GIC_V3 116 select ARM_GIC_V3_ITS if PCI 117 select ARM_PSCI_FW 118 select BUILDTIME_TABLE_SORT 119 select CLONE_BACKWARDS 120 select COMMON_CLK 121 select CPU_PM if (SUSPEND || CPU_IDLE) 122 select CRC32 123 select DCACHE_WORD_ACCESS 124 select DYNAMIC_FTRACE if FUNCTION_TRACER 125 select DMA_BOUNCE_UNALIGNED_KMALLOC 126 select DMA_DIRECT_REMAP 127 select EDAC_SUPPORT 128 select FRAME_POINTER 129 select FUNCTION_ALIGNMENT_4B 130 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 131 select GENERIC_ALLOCATOR 132 select GENERIC_ARCH_TOPOLOGY 133 select GENERIC_CLOCKEVENTS_BROADCAST 134 select GENERIC_CPU_AUTOPROBE 135 select GENERIC_CPU_VULNERABILITIES 136 select GENERIC_EARLY_IOREMAP 137 select GENERIC_IDLE_POLL_SETUP 138 select GENERIC_IOREMAP 139 select GENERIC_IRQ_IPI 140 select GENERIC_IRQ_PROBE 141 select GENERIC_IRQ_SHOW 142 select GENERIC_IRQ_SHOW_LEVEL 143 select GENERIC_LIB_DEVMEM_IS_ALLOWED 144 select GENERIC_PCI_IOMAP 145 select GENERIC_PTDUMP 146 select GENERIC_SCHED_CLOCK 147 select GENERIC_SMP_IDLE_THREAD 148 select GENERIC_TIME_VSYSCALL 149 select GENERIC_GETTIMEOFDAY 150 select GENERIC_VDSO_TIME_NS 151 select HARDIRQS_SW_RESEND 152 select HAS_IOPORT 153 select HAVE_MOVE_PMD 154 select HAVE_MOVE_PUD 155 select HAVE_PCI 156 select HAVE_ACPI_APEI if (ACPI && EFI) 157 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 158 select HAVE_ARCH_AUDITSYSCALL 159 select HAVE_ARCH_BITREVERSE 160 select HAVE_ARCH_COMPILER_H 161 select HAVE_ARCH_HUGE_VMALLOC 162 select HAVE_ARCH_HUGE_VMAP 163 select HAVE_ARCH_JUMP_LABEL 164 select HAVE_ARCH_JUMP_LABEL_RELATIVE 165 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 166 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 167 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 168 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 169 # Some instrumentation may be unsound, hence EXPERT 170 select HAVE_ARCH_KCSAN if EXPERT 171 select HAVE_ARCH_KFENCE 172 select HAVE_ARCH_KGDB 173 select HAVE_ARCH_MMAP_RND_BITS 174 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 175 select HAVE_ARCH_PREL32_RELOCATIONS 176 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 177 select HAVE_ARCH_SECCOMP_FILTER 178 select HAVE_ARCH_STACKLEAK 179 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 180 select HAVE_ARCH_TRACEHOOK 181 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 182 select HAVE_ARCH_VMAP_STACK 183 select HAVE_ARM_SMCCC 184 select HAVE_ASM_MODVERSIONS 185 select HAVE_EBPF_JIT 186 select HAVE_C_RECORDMCOUNT 187 select HAVE_CMPXCHG_DOUBLE 188 select HAVE_CMPXCHG_LOCAL 189 select HAVE_CONTEXT_TRACKING_USER 190 select HAVE_DEBUG_KMEMLEAK 191 select HAVE_DMA_CONTIGUOUS 192 select HAVE_DYNAMIC_FTRACE 193 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 194 if $(cc-option,-fpatchable-function-entry=2) 195 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 196 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 197 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 198 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 199 !CC_OPTIMIZE_FOR_SIZE) 200 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 201 if DYNAMIC_FTRACE_WITH_ARGS 202 select HAVE_SAMPLE_FTRACE_DIRECT 203 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 204 select HAVE_EFFICIENT_UNALIGNED_ACCESS 205 select HAVE_FAST_GUP 206 select HAVE_FTRACE_MCOUNT_RECORD 207 select HAVE_FUNCTION_TRACER 208 select HAVE_FUNCTION_ERROR_INJECTION 209 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 210 select HAVE_FUNCTION_GRAPH_TRACER 211 select HAVE_GCC_PLUGINS 212 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 213 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 214 select HAVE_HW_BREAKPOINT if PERF_EVENTS 215 select HAVE_IOREMAP_PROT 216 select HAVE_IRQ_TIME_ACCOUNTING 217 select HAVE_KVM 218 select HAVE_MOD_ARCH_SPECIFIC 219 select HAVE_NMI 220 select HAVE_PERF_EVENTS 221 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 222 select HAVE_PERF_REGS 223 select HAVE_PERF_USER_STACK_DUMP 224 select HAVE_PREEMPT_DYNAMIC_KEY 225 select HAVE_REGS_AND_STACK_ACCESS_API 226 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 227 select HAVE_FUNCTION_ARG_ACCESS_API 228 select MMU_GATHER_RCU_TABLE_FREE 229 select HAVE_RSEQ 230 select HAVE_STACKPROTECTOR 231 select HAVE_SYSCALL_TRACEPOINTS 232 select HAVE_KPROBES 233 select HAVE_KRETPROBES 234 select HAVE_GENERIC_VDSO 235 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 236 select IRQ_DOMAIN 237 select IRQ_FORCED_THREADING 238 select KASAN_VMALLOC if KASAN 239 select LOCK_MM_AND_FIND_VMA 240 select MODULES_USE_ELF_RELA 241 select NEED_DMA_MAP_STATE 242 select NEED_SG_DMA_LENGTH 243 select OF 244 select OF_EARLY_FLATTREE 245 select PCI_DOMAINS_GENERIC if PCI 246 select PCI_ECAM if (ACPI && PCI) 247 select PCI_SYSCALL if PCI 248 select POWER_RESET 249 select POWER_SUPPLY 250 select SPARSE_IRQ 251 select SWIOTLB 252 select SYSCTL_EXCEPTION_TRACE 253 select THREAD_INFO_IN_TASK 254 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 255 select TRACE_IRQFLAGS_SUPPORT 256 select TRACE_IRQFLAGS_NMI_SUPPORT 257 select HAVE_SOFTIRQ_ON_OWN_STACK 258 help 259 ARM 64-bit (AArch64) Linux support. 260 261config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 262 def_bool CC_IS_CLANG 263 # https://github.com/ClangBuiltLinux/linux/issues/1507 264 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 265 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 266 267config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 268 def_bool CC_IS_GCC 269 depends on $(cc-option,-fpatchable-function-entry=2) 270 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 271 272config 64BIT 273 def_bool y 274 275config MMU 276 def_bool y 277 278config ARM64_PAGE_SHIFT 279 int 280 default 16 if ARM64_64K_PAGES 281 default 14 if ARM64_16K_PAGES 282 default 12 283 284config ARM64_CONT_PTE_SHIFT 285 int 286 default 5 if ARM64_64K_PAGES 287 default 7 if ARM64_16K_PAGES 288 default 4 289 290config ARM64_CONT_PMD_SHIFT 291 int 292 default 5 if ARM64_64K_PAGES 293 default 5 if ARM64_16K_PAGES 294 default 4 295 296config ARCH_MMAP_RND_BITS_MIN 297 default 14 if ARM64_64K_PAGES 298 default 16 if ARM64_16K_PAGES 299 default 18 300 301# max bits determined by the following formula: 302# VA_BITS - PAGE_SHIFT - 3 303config ARCH_MMAP_RND_BITS_MAX 304 default 19 if ARM64_VA_BITS=36 305 default 24 if ARM64_VA_BITS=39 306 default 27 if ARM64_VA_BITS=42 307 default 30 if ARM64_VA_BITS=47 308 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 309 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 310 default 33 if ARM64_VA_BITS=48 311 default 14 if ARM64_64K_PAGES 312 default 16 if ARM64_16K_PAGES 313 default 18 314 315config ARCH_MMAP_RND_COMPAT_BITS_MIN 316 default 7 if ARM64_64K_PAGES 317 default 9 if ARM64_16K_PAGES 318 default 11 319 320config ARCH_MMAP_RND_COMPAT_BITS_MAX 321 default 16 322 323config NO_IOPORT_MAP 324 def_bool y if !PCI 325 326config STACKTRACE_SUPPORT 327 def_bool y 328 329config ILLEGAL_POINTER_VALUE 330 hex 331 default 0xdead000000000000 332 333config LOCKDEP_SUPPORT 334 def_bool y 335 336config GENERIC_BUG 337 def_bool y 338 depends on BUG 339 340config GENERIC_BUG_RELATIVE_POINTERS 341 def_bool y 342 depends on GENERIC_BUG 343 344config GENERIC_HWEIGHT 345 def_bool y 346 347config GENERIC_CSUM 348 def_bool y 349 350config GENERIC_CALIBRATE_DELAY 351 def_bool y 352 353config SMP 354 def_bool y 355 356config KERNEL_MODE_NEON 357 def_bool y 358 359config FIX_EARLYCON_MEM 360 def_bool y 361 362config PGTABLE_LEVELS 363 int 364 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 365 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 366 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 367 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 368 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 369 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 370 371config ARCH_SUPPORTS_UPROBES 372 def_bool y 373 374config ARCH_PROC_KCORE_TEXT 375 def_bool y 376 377config BROKEN_GAS_INST 378 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 379 380config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 381 bool 382 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 383 # https://reviews.llvm.org/D75044 384 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 385 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 386 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 387 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 388 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 389 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 390 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 391 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 392 default n 393 394config KASAN_SHADOW_OFFSET 395 hex 396 depends on KASAN_GENERIC || KASAN_SW_TAGS 397 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 398 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 399 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 400 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 401 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 402 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 403 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 404 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 405 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 406 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 407 default 0xffffffffffffffff 408 409config UNWIND_TABLES 410 bool 411 412source "arch/arm64/Kconfig.platforms" 413 414menu "Kernel Features" 415 416menu "ARM errata workarounds via the alternatives framework" 417 418config AMPERE_ERRATUM_AC03_CPU_38 419 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 420 default y 421 help 422 This option adds an alternative code sequence to work around Ampere 423 erratum AC03_CPU_38 on AmpereOne. 424 425 The affected design reports FEAT_HAFDBS as not implemented in 426 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 427 as required by the architecture. The unadvertised HAFDBS 428 implementation suffers from an additional erratum where hardware 429 A/D updates can occur after a PTE has been marked invalid. 430 431 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 432 which avoids enabling unadvertised hardware Access Flag management 433 at stage-2. 434 435 If unsure, say Y. 436 437config ARM64_WORKAROUND_CLEAN_CACHE 438 bool 439 440config ARM64_ERRATUM_826319 441 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 442 default y 443 select ARM64_WORKAROUND_CLEAN_CACHE 444 help 445 This option adds an alternative code sequence to work around ARM 446 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 447 AXI master interface and an L2 cache. 448 449 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 450 and is unable to accept a certain write via this interface, it will 451 not progress on read data presented on the read data channel and the 452 system can deadlock. 453 454 The workaround promotes data cache clean instructions to 455 data cache clean-and-invalidate. 456 Please note that this does not necessarily enable the workaround, 457 as it depends on the alternative framework, which will only patch 458 the kernel if an affected CPU is detected. 459 460 If unsure, say Y. 461 462config ARM64_ERRATUM_827319 463 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 464 default y 465 select ARM64_WORKAROUND_CLEAN_CACHE 466 help 467 This option adds an alternative code sequence to work around ARM 468 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 469 master interface and an L2 cache. 470 471 Under certain conditions this erratum can cause a clean line eviction 472 to occur at the same time as another transaction to the same address 473 on the AMBA 5 CHI interface, which can cause data corruption if the 474 interconnect reorders the two transactions. 475 476 The workaround promotes data cache clean instructions to 477 data cache clean-and-invalidate. 478 Please note that this does not necessarily enable the workaround, 479 as it depends on the alternative framework, which will only patch 480 the kernel if an affected CPU is detected. 481 482 If unsure, say Y. 483 484config ARM64_ERRATUM_824069 485 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 486 default y 487 select ARM64_WORKAROUND_CLEAN_CACHE 488 help 489 This option adds an alternative code sequence to work around ARM 490 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 491 to a coherent interconnect. 492 493 If a Cortex-A53 processor is executing a store or prefetch for 494 write instruction at the same time as a processor in another 495 cluster is executing a cache maintenance operation to the same 496 address, then this erratum might cause a clean cache line to be 497 incorrectly marked as dirty. 498 499 The workaround promotes data cache clean instructions to 500 data cache clean-and-invalidate. 501 Please note that this option does not necessarily enable the 502 workaround, as it depends on the alternative framework, which will 503 only patch the kernel if an affected CPU is detected. 504 505 If unsure, say Y. 506 507config ARM64_ERRATUM_819472 508 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 509 default y 510 select ARM64_WORKAROUND_CLEAN_CACHE 511 help 512 This option adds an alternative code sequence to work around ARM 513 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 514 present when it is connected to a coherent interconnect. 515 516 If the processor is executing a load and store exclusive sequence at 517 the same time as a processor in another cluster is executing a cache 518 maintenance operation to the same address, then this erratum might 519 cause data corruption. 520 521 The workaround promotes data cache clean instructions to 522 data cache clean-and-invalidate. 523 Please note that this does not necessarily enable the workaround, 524 as it depends on the alternative framework, which will only patch 525 the kernel if an affected CPU is detected. 526 527 If unsure, say Y. 528 529config ARM64_ERRATUM_832075 530 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 531 default y 532 help 533 This option adds an alternative code sequence to work around ARM 534 erratum 832075 on Cortex-A57 parts up to r1p2. 535 536 Affected Cortex-A57 parts might deadlock when exclusive load/store 537 instructions to Write-Back memory are mixed with Device loads. 538 539 The workaround is to promote device loads to use Load-Acquire 540 semantics. 541 Please note that this does not necessarily enable the workaround, 542 as it depends on the alternative framework, which will only patch 543 the kernel if an affected CPU is detected. 544 545 If unsure, say Y. 546 547config ARM64_ERRATUM_834220 548 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 549 depends on KVM 550 default y 551 help 552 This option adds an alternative code sequence to work around ARM 553 erratum 834220 on Cortex-A57 parts up to r1p2. 554 555 Affected Cortex-A57 parts might report a Stage 2 translation 556 fault as the result of a Stage 1 fault for load crossing a 557 page boundary when there is a permission or device memory 558 alignment fault at Stage 1 and a translation fault at Stage 2. 559 560 The workaround is to verify that the Stage 1 translation 561 doesn't generate a fault before handling the Stage 2 fault. 562 Please note that this does not necessarily enable the workaround, 563 as it depends on the alternative framework, which will only patch 564 the kernel if an affected CPU is detected. 565 566 If unsure, say Y. 567 568config ARM64_ERRATUM_1742098 569 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 570 depends on COMPAT 571 default y 572 help 573 This option removes the AES hwcap for aarch32 user-space to 574 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 575 576 Affected parts may corrupt the AES state if an interrupt is 577 taken between a pair of AES instructions. These instructions 578 are only present if the cryptography extensions are present. 579 All software should have a fallback implementation for CPUs 580 that don't implement the cryptography extensions. 581 582 If unsure, say Y. 583 584config ARM64_ERRATUM_845719 585 bool "Cortex-A53: 845719: a load might read incorrect data" 586 depends on COMPAT 587 default y 588 help 589 This option adds an alternative code sequence to work around ARM 590 erratum 845719 on Cortex-A53 parts up to r0p4. 591 592 When running a compat (AArch32) userspace on an affected Cortex-A53 593 part, a load at EL0 from a virtual address that matches the bottom 32 594 bits of the virtual address used by a recent load at (AArch64) EL1 595 might return incorrect data. 596 597 The workaround is to write the contextidr_el1 register on exception 598 return to a 32-bit task. 599 Please note that this does not necessarily enable the workaround, 600 as it depends on the alternative framework, which will only patch 601 the kernel if an affected CPU is detected. 602 603 If unsure, say Y. 604 605config ARM64_ERRATUM_843419 606 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 607 default y 608 help 609 This option links the kernel with '--fix-cortex-a53-843419' and 610 enables PLT support to replace certain ADRP instructions, which can 611 cause subsequent memory accesses to use an incorrect address on 612 Cortex-A53 parts up to r0p4. 613 614 If unsure, say Y. 615 616config ARM64_LD_HAS_FIX_ERRATUM_843419 617 def_bool $(ld-option,--fix-cortex-a53-843419) 618 619config ARM64_ERRATUM_1024718 620 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 621 default y 622 help 623 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 624 625 Affected Cortex-A55 cores (all revisions) could cause incorrect 626 update of the hardware dirty bit when the DBM/AP bits are updated 627 without a break-before-make. The workaround is to disable the usage 628 of hardware DBM locally on the affected cores. CPUs not affected by 629 this erratum will continue to use the feature. 630 631 If unsure, say Y. 632 633config ARM64_ERRATUM_1418040 634 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 635 default y 636 depends on COMPAT 637 help 638 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 639 errata 1188873 and 1418040. 640 641 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 642 cause register corruption when accessing the timer registers 643 from AArch32 userspace. 644 645 If unsure, say Y. 646 647config ARM64_WORKAROUND_SPECULATIVE_AT 648 bool 649 650config ARM64_ERRATUM_1165522 651 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 652 default y 653 select ARM64_WORKAROUND_SPECULATIVE_AT 654 help 655 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 656 657 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 658 corrupted TLBs by speculating an AT instruction during a guest 659 context switch. 660 661 If unsure, say Y. 662 663config ARM64_ERRATUM_1319367 664 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 665 default y 666 select ARM64_WORKAROUND_SPECULATIVE_AT 667 help 668 This option adds work arounds for ARM Cortex-A57 erratum 1319537 669 and A72 erratum 1319367 670 671 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 672 speculating an AT instruction during a guest context switch. 673 674 If unsure, say Y. 675 676config ARM64_ERRATUM_1530923 677 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 678 default y 679 select ARM64_WORKAROUND_SPECULATIVE_AT 680 help 681 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 682 683 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 684 corrupted TLBs by speculating an AT instruction during a guest 685 context switch. 686 687 If unsure, say Y. 688 689config ARM64_WORKAROUND_REPEAT_TLBI 690 bool 691 692config ARM64_ERRATUM_2441007 693 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 694 default y 695 select ARM64_WORKAROUND_REPEAT_TLBI 696 help 697 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 698 699 Under very rare circumstances, affected Cortex-A55 CPUs 700 may not handle a race between a break-before-make sequence on one 701 CPU, and another CPU accessing the same page. This could allow a 702 store to a page that has been unmapped. 703 704 Work around this by adding the affected CPUs to the list that needs 705 TLB sequences to be done twice. 706 707 If unsure, say Y. 708 709config ARM64_ERRATUM_1286807 710 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 711 default y 712 select ARM64_WORKAROUND_REPEAT_TLBI 713 help 714 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 715 716 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 717 address for a cacheable mapping of a location is being 718 accessed by a core while another core is remapping the virtual 719 address to a new physical page using the recommended 720 break-before-make sequence, then under very rare circumstances 721 TLBI+DSB completes before a read using the translation being 722 invalidated has been observed by other observers. The 723 workaround repeats the TLBI+DSB operation. 724 725config ARM64_ERRATUM_1463225 726 bool "Cortex-A76: Software Step might prevent interrupt recognition" 727 default y 728 help 729 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 730 731 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 732 of a system call instruction (SVC) can prevent recognition of 733 subsequent interrupts when software stepping is disabled in the 734 exception handler of the system call and either kernel debugging 735 is enabled or VHE is in use. 736 737 Work around the erratum by triggering a dummy step exception 738 when handling a system call from a task that is being stepped 739 in a VHE configuration of the kernel. 740 741 If unsure, say Y. 742 743config ARM64_ERRATUM_1542419 744 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 745 default y 746 help 747 This option adds a workaround for ARM Neoverse-N1 erratum 748 1542419. 749 750 Affected Neoverse-N1 cores could execute a stale instruction when 751 modified by another CPU. The workaround depends on a firmware 752 counterpart. 753 754 Workaround the issue by hiding the DIC feature from EL0. This 755 forces user-space to perform cache maintenance. 756 757 If unsure, say Y. 758 759config ARM64_ERRATUM_1508412 760 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 761 default y 762 help 763 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 764 765 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 766 of a store-exclusive or read of PAR_EL1 and a load with device or 767 non-cacheable memory attributes. The workaround depends on a firmware 768 counterpart. 769 770 KVM guests must also have the workaround implemented or they can 771 deadlock the system. 772 773 Work around the issue by inserting DMB SY barriers around PAR_EL1 774 register reads and warning KVM users. The DMB barrier is sufficient 775 to prevent a speculative PAR_EL1 read. 776 777 If unsure, say Y. 778 779config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 780 bool 781 782config ARM64_ERRATUM_2051678 783 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 784 default y 785 help 786 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 787 Affected Cortex-A510 might not respect the ordering rules for 788 hardware update of the page table's dirty bit. The workaround 789 is to not enable the feature on affected CPUs. 790 791 If unsure, say Y. 792 793config ARM64_ERRATUM_2077057 794 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 795 default y 796 help 797 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 798 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 799 expected, but a Pointer Authentication trap is taken instead. The 800 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 801 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 802 803 This can only happen when EL2 is stepping EL1. 804 805 When these conditions occur, the SPSR_EL2 value is unchanged from the 806 previous guest entry, and can be restored from the in-memory copy. 807 808 If unsure, say Y. 809 810config ARM64_ERRATUM_2658417 811 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 812 default y 813 help 814 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 815 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 816 BFMMLA or VMMLA instructions in rare circumstances when a pair of 817 A510 CPUs are using shared neon hardware. As the sharing is not 818 discoverable by the kernel, hide the BF16 HWCAP to indicate that 819 user-space should not be using these instructions. 820 821 If unsure, say Y. 822 823config ARM64_ERRATUM_2119858 824 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 825 default y 826 depends on CORESIGHT_TRBE 827 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 828 help 829 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 830 831 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 832 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 833 the event of a WRAP event. 834 835 Work around the issue by always making sure we move the TRBPTR_EL1 by 836 256 bytes before enabling the buffer and filling the first 256 bytes of 837 the buffer with ETM ignore packets upon disabling. 838 839 If unsure, say Y. 840 841config ARM64_ERRATUM_2139208 842 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 843 default y 844 depends on CORESIGHT_TRBE 845 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 846 help 847 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 848 849 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 850 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 851 the event of a WRAP event. 852 853 Work around the issue by always making sure we move the TRBPTR_EL1 by 854 256 bytes before enabling the buffer and filling the first 256 bytes of 855 the buffer with ETM ignore packets upon disabling. 856 857 If unsure, say Y. 858 859config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 860 bool 861 862config ARM64_ERRATUM_2054223 863 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 864 default y 865 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 866 help 867 Enable workaround for ARM Cortex-A710 erratum 2054223 868 869 Affected cores may fail to flush the trace data on a TSB instruction, when 870 the PE is in trace prohibited state. This will cause losing a few bytes 871 of the trace cached. 872 873 Workaround is to issue two TSB consecutively on affected cores. 874 875 If unsure, say Y. 876 877config ARM64_ERRATUM_2067961 878 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 879 default y 880 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 881 help 882 Enable workaround for ARM Neoverse-N2 erratum 2067961 883 884 Affected cores may fail to flush the trace data on a TSB instruction, when 885 the PE is in trace prohibited state. This will cause losing a few bytes 886 of the trace cached. 887 888 Workaround is to issue two TSB consecutively on affected cores. 889 890 If unsure, say Y. 891 892config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 893 bool 894 895config ARM64_ERRATUM_2253138 896 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 897 depends on CORESIGHT_TRBE 898 default y 899 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 900 help 901 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 902 903 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 904 for TRBE. Under some conditions, the TRBE might generate a write to the next 905 virtually addressed page following the last page of the TRBE address space 906 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 907 908 Work around this in the driver by always making sure that there is a 909 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 910 911 If unsure, say Y. 912 913config ARM64_ERRATUM_2224489 914 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 915 depends on CORESIGHT_TRBE 916 default y 917 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 918 help 919 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 920 921 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 922 for TRBE. Under some conditions, the TRBE might generate a write to the next 923 virtually addressed page following the last page of the TRBE address space 924 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 925 926 Work around this in the driver by always making sure that there is a 927 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 928 929 If unsure, say Y. 930 931config ARM64_ERRATUM_2441009 932 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 933 default y 934 select ARM64_WORKAROUND_REPEAT_TLBI 935 help 936 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 937 938 Under very rare circumstances, affected Cortex-A510 CPUs 939 may not handle a race between a break-before-make sequence on one 940 CPU, and another CPU accessing the same page. This could allow a 941 store to a page that has been unmapped. 942 943 Work around this by adding the affected CPUs to the list that needs 944 TLB sequences to be done twice. 945 946 If unsure, say Y. 947 948config ARM64_ERRATUM_2064142 949 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 950 depends on CORESIGHT_TRBE 951 default y 952 help 953 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 954 955 Affected Cortex-A510 core might fail to write into system registers after the 956 TRBE has been disabled. Under some conditions after the TRBE has been disabled 957 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 958 and TRBTRG_EL1 will be ignored and will not be effected. 959 960 Work around this in the driver by executing TSB CSYNC and DSB after collection 961 is stopped and before performing a system register write to one of the affected 962 registers. 963 964 If unsure, say Y. 965 966config ARM64_ERRATUM_2038923 967 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 968 depends on CORESIGHT_TRBE 969 default y 970 help 971 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 972 973 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 974 prohibited within the CPU. As a result, the trace buffer or trace buffer state 975 might be corrupted. This happens after TRBE buffer has been enabled by setting 976 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 977 execution changes from a context, in which trace is prohibited to one where it 978 isn't, or vice versa. In these mentioned conditions, the view of whether trace 979 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 980 the trace buffer state might be corrupted. 981 982 Work around this in the driver by preventing an inconsistent view of whether the 983 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 984 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 985 two ISB instructions if no ERET is to take place. 986 987 If unsure, say Y. 988 989config ARM64_ERRATUM_1902691 990 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 991 depends on CORESIGHT_TRBE 992 default y 993 help 994 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 995 996 Affected Cortex-A510 core might cause trace data corruption, when being written 997 into the memory. Effectively TRBE is broken and hence cannot be used to capture 998 trace data. 999 1000 Work around this problem in the driver by just preventing TRBE initialization on 1001 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1002 on such implementations. This will cover the kernel for any firmware that doesn't 1003 do this already. 1004 1005 If unsure, say Y. 1006 1007config ARM64_ERRATUM_2457168 1008 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1009 depends on ARM64_AMU_EXTN 1010 default y 1011 help 1012 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1013 1014 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1015 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1016 incorrectly giving a significantly higher output value. 1017 1018 Work around this problem by returning 0 when reading the affected counter in 1019 key locations that results in disabling all users of this counter. This effect 1020 is the same to firmware disabling affected counters. 1021 1022 If unsure, say Y. 1023 1024config ARM64_ERRATUM_2645198 1025 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1026 default y 1027 help 1028 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1029 1030 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1031 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1032 next instruction abort caused by permission fault. 1033 1034 Only user-space does executable to non-executable permission transition via 1035 mprotect() system call. Workaround the problem by doing a break-before-make 1036 TLB invalidation, for all changes to executable user space mappings. 1037 1038 If unsure, say Y. 1039 1040config CAVIUM_ERRATUM_22375 1041 bool "Cavium erratum 22375, 24313" 1042 default y 1043 help 1044 Enable workaround for errata 22375 and 24313. 1045 1046 This implements two gicv3-its errata workarounds for ThunderX. Both 1047 with a small impact affecting only ITS table allocation. 1048 1049 erratum 22375: only alloc 8MB table size 1050 erratum 24313: ignore memory access type 1051 1052 The fixes are in ITS initialization and basically ignore memory access 1053 type and table size provided by the TYPER and BASER registers. 1054 1055 If unsure, say Y. 1056 1057config CAVIUM_ERRATUM_23144 1058 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1059 depends on NUMA 1060 default y 1061 help 1062 ITS SYNC command hang for cross node io and collections/cpu mapping. 1063 1064 If unsure, say Y. 1065 1066config CAVIUM_ERRATUM_23154 1067 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1068 default y 1069 help 1070 The ThunderX GICv3 implementation requires a modified version for 1071 reading the IAR status to ensure data synchronization 1072 (access to icc_iar1_el1 is not sync'ed before and after). 1073 1074 It also suffers from erratum 38545 (also present on Marvell's 1075 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1076 spuriously presented to the CPU interface. 1077 1078 If unsure, say Y. 1079 1080config CAVIUM_ERRATUM_27456 1081 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1082 default y 1083 help 1084 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1085 instructions may cause the icache to become corrupted if it 1086 contains data for a non-current ASID. The fix is to 1087 invalidate the icache when changing the mm context. 1088 1089 If unsure, say Y. 1090 1091config CAVIUM_ERRATUM_30115 1092 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1093 default y 1094 help 1095 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1096 1.2, and T83 Pass 1.0, KVM guest execution may disable 1097 interrupts in host. Trapping both GICv3 group-0 and group-1 1098 accesses sidesteps the issue. 1099 1100 If unsure, say Y. 1101 1102config CAVIUM_TX2_ERRATUM_219 1103 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1104 default y 1105 help 1106 On Cavium ThunderX2, a load, store or prefetch instruction between a 1107 TTBR update and the corresponding context synchronizing operation can 1108 cause a spurious Data Abort to be delivered to any hardware thread in 1109 the CPU core. 1110 1111 Work around the issue by avoiding the problematic code sequence and 1112 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1113 trap handler performs the corresponding register access, skips the 1114 instruction and ensures context synchronization by virtue of the 1115 exception return. 1116 1117 If unsure, say Y. 1118 1119config FUJITSU_ERRATUM_010001 1120 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1121 default y 1122 help 1123 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1124 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1125 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1126 This fault occurs under a specific hardware condition when a 1127 load/store instruction performs an address translation using: 1128 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1129 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1130 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1131 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1132 1133 The workaround is to ensure these bits are clear in TCR_ELx. 1134 The workaround only affects the Fujitsu-A64FX. 1135 1136 If unsure, say Y. 1137 1138config HISILICON_ERRATUM_161600802 1139 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1140 default y 1141 help 1142 The HiSilicon Hip07 SoC uses the wrong redistributor base 1143 when issued ITS commands such as VMOVP and VMAPP, and requires 1144 a 128kB offset to be applied to the target address in this commands. 1145 1146 If unsure, say Y. 1147 1148config QCOM_FALKOR_ERRATUM_1003 1149 bool "Falkor E1003: Incorrect translation due to ASID change" 1150 default y 1151 help 1152 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1153 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1154 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1155 then only for entries in the walk cache, since the leaf translation 1156 is unchanged. Work around the erratum by invalidating the walk cache 1157 entries for the trampoline before entering the kernel proper. 1158 1159config QCOM_FALKOR_ERRATUM_1009 1160 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1161 default y 1162 select ARM64_WORKAROUND_REPEAT_TLBI 1163 help 1164 On Falkor v1, the CPU may prematurely complete a DSB following a 1165 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1166 one more time to fix the issue. 1167 1168 If unsure, say Y. 1169 1170config QCOM_QDF2400_ERRATUM_0065 1171 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1172 default y 1173 help 1174 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1175 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1176 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1177 1178 If unsure, say Y. 1179 1180config QCOM_FALKOR_ERRATUM_E1041 1181 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1182 default y 1183 help 1184 Falkor CPU may speculatively fetch instructions from an improper 1185 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1186 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1187 1188 If unsure, say Y. 1189 1190config NVIDIA_CARMEL_CNP_ERRATUM 1191 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1192 default y 1193 help 1194 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1195 invalidate shared TLB entries installed by a different core, as it would 1196 on standard ARM cores. 1197 1198 If unsure, say Y. 1199 1200config ROCKCHIP_ERRATUM_3588001 1201 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1202 default y 1203 help 1204 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1205 This means, that its sharability feature may not be used, even though it 1206 is supported by the IP itself. 1207 1208 If unsure, say Y. 1209 1210config SOCIONEXT_SYNQUACER_PREITS 1211 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1212 default y 1213 help 1214 Socionext Synquacer SoCs implement a separate h/w block to generate 1215 MSI doorbell writes with non-zero values for the device ID. 1216 1217 If unsure, say Y. 1218 1219endmenu # "ARM errata workarounds via the alternatives framework" 1220 1221choice 1222 prompt "Page size" 1223 default ARM64_4K_PAGES 1224 help 1225 Page size (translation granule) configuration. 1226 1227config ARM64_4K_PAGES 1228 bool "4KB" 1229 help 1230 This feature enables 4KB pages support. 1231 1232config ARM64_16K_PAGES 1233 bool "16KB" 1234 help 1235 The system will use 16KB pages support. AArch32 emulation 1236 requires applications compiled with 16K (or a multiple of 16K) 1237 aligned segments. 1238 1239config ARM64_64K_PAGES 1240 bool "64KB" 1241 help 1242 This feature enables 64KB pages support (4KB by default) 1243 allowing only two levels of page tables and faster TLB 1244 look-up. AArch32 emulation requires applications compiled 1245 with 64K aligned segments. 1246 1247endchoice 1248 1249choice 1250 prompt "Virtual address space size" 1251 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1252 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1253 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1254 help 1255 Allows choosing one of multiple possible virtual address 1256 space sizes. The level of translation table is determined by 1257 a combination of page size and virtual address space size. 1258 1259config ARM64_VA_BITS_36 1260 bool "36-bit" if EXPERT 1261 depends on ARM64_16K_PAGES 1262 1263config ARM64_VA_BITS_39 1264 bool "39-bit" 1265 depends on ARM64_4K_PAGES 1266 1267config ARM64_VA_BITS_42 1268 bool "42-bit" 1269 depends on ARM64_64K_PAGES 1270 1271config ARM64_VA_BITS_47 1272 bool "47-bit" 1273 depends on ARM64_16K_PAGES 1274 1275config ARM64_VA_BITS_48 1276 bool "48-bit" 1277 1278config ARM64_VA_BITS_52 1279 bool "52-bit" 1280 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1281 help 1282 Enable 52-bit virtual addressing for userspace when explicitly 1283 requested via a hint to mmap(). The kernel will also use 52-bit 1284 virtual addresses for its own mappings (provided HW support for 1285 this feature is available, otherwise it reverts to 48-bit). 1286 1287 NOTE: Enabling 52-bit virtual addressing in conjunction with 1288 ARMv8.3 Pointer Authentication will result in the PAC being 1289 reduced from 7 bits to 3 bits, which may have a significant 1290 impact on its susceptibility to brute-force attacks. 1291 1292 If unsure, select 48-bit virtual addressing instead. 1293 1294endchoice 1295 1296config ARM64_FORCE_52BIT 1297 bool "Force 52-bit virtual addresses for userspace" 1298 depends on ARM64_VA_BITS_52 && EXPERT 1299 help 1300 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1301 to maintain compatibility with older software by providing 48-bit VAs 1302 unless a hint is supplied to mmap. 1303 1304 This configuration option disables the 48-bit compatibility logic, and 1305 forces all userspace addresses to be 52-bit on HW that supports it. One 1306 should only enable this configuration option for stress testing userspace 1307 memory management code. If unsure say N here. 1308 1309config ARM64_VA_BITS 1310 int 1311 default 36 if ARM64_VA_BITS_36 1312 default 39 if ARM64_VA_BITS_39 1313 default 42 if ARM64_VA_BITS_42 1314 default 47 if ARM64_VA_BITS_47 1315 default 48 if ARM64_VA_BITS_48 1316 default 52 if ARM64_VA_BITS_52 1317 1318choice 1319 prompt "Physical address space size" 1320 default ARM64_PA_BITS_48 1321 help 1322 Choose the maximum physical address range that the kernel will 1323 support. 1324 1325config ARM64_PA_BITS_48 1326 bool "48-bit" 1327 1328config ARM64_PA_BITS_52 1329 bool "52-bit (ARMv8.2)" 1330 depends on ARM64_64K_PAGES 1331 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1332 help 1333 Enable support for a 52-bit physical address space, introduced as 1334 part of the ARMv8.2-LPA extension. 1335 1336 With this enabled, the kernel will also continue to work on CPUs that 1337 do not support ARMv8.2-LPA, but with some added memory overhead (and 1338 minor performance overhead). 1339 1340endchoice 1341 1342config ARM64_PA_BITS 1343 int 1344 default 48 if ARM64_PA_BITS_48 1345 default 52 if ARM64_PA_BITS_52 1346 1347choice 1348 prompt "Endianness" 1349 default CPU_LITTLE_ENDIAN 1350 help 1351 Select the endianness of data accesses performed by the CPU. Userspace 1352 applications will need to be compiled and linked for the endianness 1353 that is selected here. 1354 1355config CPU_BIG_ENDIAN 1356 bool "Build big-endian kernel" 1357 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1358 help 1359 Say Y if you plan on running a kernel with a big-endian userspace. 1360 1361config CPU_LITTLE_ENDIAN 1362 bool "Build little-endian kernel" 1363 help 1364 Say Y if you plan on running a kernel with a little-endian userspace. 1365 This is usually the case for distributions targeting arm64. 1366 1367endchoice 1368 1369config SCHED_MC 1370 bool "Multi-core scheduler support" 1371 help 1372 Multi-core scheduler support improves the CPU scheduler's decision 1373 making when dealing with multi-core CPU chips at a cost of slightly 1374 increased overhead in some places. If unsure say N here. 1375 1376config SCHED_CLUSTER 1377 bool "Cluster scheduler support" 1378 help 1379 Cluster scheduler support improves the CPU scheduler's decision 1380 making when dealing with machines that have clusters of CPUs. 1381 Cluster usually means a couple of CPUs which are placed closely 1382 by sharing mid-level caches, last-level cache tags or internal 1383 busses. 1384 1385config SCHED_SMT 1386 bool "SMT scheduler support" 1387 help 1388 Improves the CPU scheduler's decision making when dealing with 1389 MultiThreading at a cost of slightly increased overhead in some 1390 places. If unsure say N here. 1391 1392config NR_CPUS 1393 int "Maximum number of CPUs (2-4096)" 1394 range 2 4096 1395 default "256" 1396 1397config HOTPLUG_CPU 1398 bool "Support for hot-pluggable CPUs" 1399 select GENERIC_IRQ_MIGRATION 1400 help 1401 Say Y here to experiment with turning CPUs off and on. CPUs 1402 can be controlled through /sys/devices/system/cpu. 1403 1404# Common NUMA Features 1405config NUMA 1406 bool "NUMA Memory Allocation and Scheduler Support" 1407 select GENERIC_ARCH_NUMA 1408 select ACPI_NUMA if ACPI 1409 select OF_NUMA 1410 select HAVE_SETUP_PER_CPU_AREA 1411 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1412 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1413 select USE_PERCPU_NUMA_NODE_ID 1414 help 1415 Enable NUMA (Non-Uniform Memory Access) support. 1416 1417 The kernel will try to allocate memory used by a CPU on the 1418 local memory of the CPU and add some more 1419 NUMA awareness to the kernel. 1420 1421config NODES_SHIFT 1422 int "Maximum NUMA Nodes (as a power of 2)" 1423 range 1 10 1424 default "4" 1425 depends on NUMA 1426 help 1427 Specify the maximum number of NUMA Nodes available on the target 1428 system. Increases memory reserved to accommodate various tables. 1429 1430source "kernel/Kconfig.hz" 1431 1432config ARCH_SPARSEMEM_ENABLE 1433 def_bool y 1434 select SPARSEMEM_VMEMMAP_ENABLE 1435 select SPARSEMEM_VMEMMAP 1436 1437config HW_PERF_EVENTS 1438 def_bool y 1439 depends on ARM_PMU 1440 1441# Supported by clang >= 7.0 or GCC >= 12.0.0 1442config CC_HAVE_SHADOW_CALL_STACK 1443 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1444 1445config PARAVIRT 1446 bool "Enable paravirtualization code" 1447 help 1448 This changes the kernel so it can modify itself when it is run 1449 under a hypervisor, potentially improving performance significantly 1450 over full virtualization. 1451 1452config PARAVIRT_TIME_ACCOUNTING 1453 bool "Paravirtual steal time accounting" 1454 select PARAVIRT 1455 help 1456 Select this option to enable fine granularity task steal time 1457 accounting. Time spent executing other tasks in parallel with 1458 the current vCPU is discounted from the vCPU power. To account for 1459 that, there can be a small performance impact. 1460 1461 If in doubt, say N here. 1462 1463config ARCH_SUPPORTS_KEXEC 1464 def_bool PM_SLEEP_SMP 1465 1466config ARCH_SUPPORTS_KEXEC_FILE 1467 def_bool y 1468 1469config ARCH_SELECTS_KEXEC_FILE 1470 def_bool y 1471 depends on KEXEC_FILE 1472 select HAVE_IMA_KEXEC if IMA 1473 1474config ARCH_SUPPORTS_KEXEC_SIG 1475 def_bool y 1476 1477config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1478 def_bool y 1479 1480config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1481 def_bool y 1482 1483config ARCH_SUPPORTS_CRASH_DUMP 1484 def_bool y 1485 1486config TRANS_TABLE 1487 def_bool y 1488 depends on HIBERNATION || KEXEC_CORE 1489 1490config XEN_DOM0 1491 def_bool y 1492 depends on XEN 1493 1494config XEN 1495 bool "Xen guest support on ARM64" 1496 depends on ARM64 && OF 1497 select SWIOTLB_XEN 1498 select PARAVIRT 1499 help 1500 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1501 1502# include/linux/mmzone.h requires the following to be true: 1503# 1504# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1505# 1506# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1507# 1508# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1509# ----+-------------------+--------------+-----------------+--------------------+ 1510# 4K | 27 | 12 | 15 | 10 | 1511# 16K | 27 | 14 | 13 | 11 | 1512# 64K | 29 | 16 | 13 | 13 | 1513config ARCH_FORCE_MAX_ORDER 1514 int 1515 default "13" if ARM64_64K_PAGES 1516 default "11" if ARM64_16K_PAGES 1517 default "10" 1518 help 1519 The kernel page allocator limits the size of maximal physically 1520 contiguous allocations. The limit is called MAX_ORDER and it 1521 defines the maximal power of two of number of pages that can be 1522 allocated as a single contiguous block. This option allows 1523 overriding the default setting when ability to allocate very 1524 large blocks of physically contiguous memory is required. 1525 1526 The maximal size of allocation cannot exceed the size of the 1527 section, so the value of MAX_ORDER should satisfy 1528 1529 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1530 1531 Don't change if unsure. 1532 1533config UNMAP_KERNEL_AT_EL0 1534 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1535 default y 1536 help 1537 Speculation attacks against some high-performance processors can 1538 be used to bypass MMU permission checks and leak kernel data to 1539 userspace. This can be defended against by unmapping the kernel 1540 when running in userspace, mapping it back in on exception entry 1541 via a trampoline page in the vector table. 1542 1543 If unsure, say Y. 1544 1545config MITIGATE_SPECTRE_BRANCH_HISTORY 1546 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1547 default y 1548 help 1549 Speculation attacks against some high-performance processors can 1550 make use of branch history to influence future speculation. 1551 When taking an exception from user-space, a sequence of branches 1552 or a firmware call overwrites the branch history. 1553 1554config RODATA_FULL_DEFAULT_ENABLED 1555 bool "Apply r/o permissions of VM areas also to their linear aliases" 1556 default y 1557 help 1558 Apply read-only attributes of VM areas to the linear alias of 1559 the backing pages as well. This prevents code or read-only data 1560 from being modified (inadvertently or intentionally) via another 1561 mapping of the same memory page. This additional enhancement can 1562 be turned off at runtime by passing rodata=[off|on] (and turned on 1563 with rodata=full if this option is set to 'n') 1564 1565 This requires the linear region to be mapped down to pages, 1566 which may adversely affect performance in some cases. 1567 1568config ARM64_SW_TTBR0_PAN 1569 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1570 help 1571 Enabling this option prevents the kernel from accessing 1572 user-space memory directly by pointing TTBR0_EL1 to a reserved 1573 zeroed area and reserved ASID. The user access routines 1574 restore the valid TTBR0_EL1 temporarily. 1575 1576config ARM64_TAGGED_ADDR_ABI 1577 bool "Enable the tagged user addresses syscall ABI" 1578 default y 1579 help 1580 When this option is enabled, user applications can opt in to a 1581 relaxed ABI via prctl() allowing tagged addresses to be passed 1582 to system calls as pointer arguments. For details, see 1583 Documentation/arch/arm64/tagged-address-abi.rst. 1584 1585menuconfig COMPAT 1586 bool "Kernel support for 32-bit EL0" 1587 depends on ARM64_4K_PAGES || EXPERT 1588 select HAVE_UID16 1589 select OLD_SIGSUSPEND3 1590 select COMPAT_OLD_SIGACTION 1591 help 1592 This option enables support for a 32-bit EL0 running under a 64-bit 1593 kernel at EL1. AArch32-specific components such as system calls, 1594 the user helper functions, VFP support and the ptrace interface are 1595 handled appropriately by the kernel. 1596 1597 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1598 that you will only be able to execute AArch32 binaries that were compiled 1599 with page size aligned segments. 1600 1601 If you want to execute 32-bit userspace applications, say Y. 1602 1603if COMPAT 1604 1605config KUSER_HELPERS 1606 bool "Enable kuser helpers page for 32-bit applications" 1607 default y 1608 help 1609 Warning: disabling this option may break 32-bit user programs. 1610 1611 Provide kuser helpers to compat tasks. The kernel provides 1612 helper code to userspace in read only form at a fixed location 1613 to allow userspace to be independent of the CPU type fitted to 1614 the system. This permits binaries to be run on ARMv4 through 1615 to ARMv8 without modification. 1616 1617 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1618 1619 However, the fixed address nature of these helpers can be used 1620 by ROP (return orientated programming) authors when creating 1621 exploits. 1622 1623 If all of the binaries and libraries which run on your platform 1624 are built specifically for your platform, and make no use of 1625 these helpers, then you can turn this option off to hinder 1626 such exploits. However, in that case, if a binary or library 1627 relying on those helpers is run, it will not function correctly. 1628 1629 Say N here only if you are absolutely certain that you do not 1630 need these helpers; otherwise, the safe option is to say Y. 1631 1632config COMPAT_VDSO 1633 bool "Enable vDSO for 32-bit applications" 1634 depends on !CPU_BIG_ENDIAN 1635 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1636 select GENERIC_COMPAT_VDSO 1637 default y 1638 help 1639 Place in the process address space of 32-bit applications an 1640 ELF shared object providing fast implementations of gettimeofday 1641 and clock_gettime. 1642 1643 You must have a 32-bit build of glibc 2.22 or later for programs 1644 to seamlessly take advantage of this. 1645 1646config THUMB2_COMPAT_VDSO 1647 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1648 depends on COMPAT_VDSO 1649 default y 1650 help 1651 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1652 otherwise with '-marm'. 1653 1654config COMPAT_ALIGNMENT_FIXUPS 1655 bool "Fix up misaligned multi-word loads and stores in user space" 1656 1657menuconfig ARMV8_DEPRECATED 1658 bool "Emulate deprecated/obsolete ARMv8 instructions" 1659 depends on SYSCTL 1660 help 1661 Legacy software support may require certain instructions 1662 that have been deprecated or obsoleted in the architecture. 1663 1664 Enable this config to enable selective emulation of these 1665 features. 1666 1667 If unsure, say Y 1668 1669if ARMV8_DEPRECATED 1670 1671config SWP_EMULATION 1672 bool "Emulate SWP/SWPB instructions" 1673 help 1674 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1675 they are always undefined. Say Y here to enable software 1676 emulation of these instructions for userspace using LDXR/STXR. 1677 This feature can be controlled at runtime with the abi.swp 1678 sysctl which is disabled by default. 1679 1680 In some older versions of glibc [<=2.8] SWP is used during futex 1681 trylock() operations with the assumption that the code will not 1682 be preempted. This invalid assumption may be more likely to fail 1683 with SWP emulation enabled, leading to deadlock of the user 1684 application. 1685 1686 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1687 on an external transaction monitoring block called a global 1688 monitor to maintain update atomicity. If your system does not 1689 implement a global monitor, this option can cause programs that 1690 perform SWP operations to uncached memory to deadlock. 1691 1692 If unsure, say Y 1693 1694config CP15_BARRIER_EMULATION 1695 bool "Emulate CP15 Barrier instructions" 1696 help 1697 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1698 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1699 strongly recommended to use the ISB, DSB, and DMB 1700 instructions instead. 1701 1702 Say Y here to enable software emulation of these 1703 instructions for AArch32 userspace code. When this option is 1704 enabled, CP15 barrier usage is traced which can help 1705 identify software that needs updating. This feature can be 1706 controlled at runtime with the abi.cp15_barrier sysctl. 1707 1708 If unsure, say Y 1709 1710config SETEND_EMULATION 1711 bool "Emulate SETEND instruction" 1712 help 1713 The SETEND instruction alters the data-endianness of the 1714 AArch32 EL0, and is deprecated in ARMv8. 1715 1716 Say Y here to enable software emulation of the instruction 1717 for AArch32 userspace code. This feature can be controlled 1718 at runtime with the abi.setend sysctl. 1719 1720 Note: All the cpus on the system must have mixed endian support at EL0 1721 for this feature to be enabled. If a new CPU - which doesn't support mixed 1722 endian - is hotplugged in after this feature has been enabled, there could 1723 be unexpected results in the applications. 1724 1725 If unsure, say Y 1726endif # ARMV8_DEPRECATED 1727 1728endif # COMPAT 1729 1730menu "ARMv8.1 architectural features" 1731 1732config ARM64_HW_AFDBM 1733 bool "Support for hardware updates of the Access and Dirty page flags" 1734 default y 1735 help 1736 The ARMv8.1 architecture extensions introduce support for 1737 hardware updates of the access and dirty information in page 1738 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1739 capable processors, accesses to pages with PTE_AF cleared will 1740 set this bit instead of raising an access flag fault. 1741 Similarly, writes to read-only pages with the DBM bit set will 1742 clear the read-only bit (AP[2]) instead of raising a 1743 permission fault. 1744 1745 Kernels built with this configuration option enabled continue 1746 to work on pre-ARMv8.1 hardware and the performance impact is 1747 minimal. If unsure, say Y. 1748 1749config ARM64_PAN 1750 bool "Enable support for Privileged Access Never (PAN)" 1751 default y 1752 help 1753 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1754 prevents the kernel or hypervisor from accessing user-space (EL0) 1755 memory directly. 1756 1757 Choosing this option will cause any unprotected (not using 1758 copy_to_user et al) memory access to fail with a permission fault. 1759 1760 The feature is detected at runtime, and will remain as a 'nop' 1761 instruction if the cpu does not implement the feature. 1762 1763config AS_HAS_LSE_ATOMICS 1764 def_bool $(as-instr,.arch_extension lse) 1765 1766config ARM64_LSE_ATOMICS 1767 bool 1768 default ARM64_USE_LSE_ATOMICS 1769 depends on AS_HAS_LSE_ATOMICS 1770 1771config ARM64_USE_LSE_ATOMICS 1772 bool "Atomic instructions" 1773 default y 1774 help 1775 As part of the Large System Extensions, ARMv8.1 introduces new 1776 atomic instructions that are designed specifically to scale in 1777 very large systems. 1778 1779 Say Y here to make use of these instructions for the in-kernel 1780 atomic routines. This incurs a small overhead on CPUs that do 1781 not support these instructions and requires the kernel to be 1782 built with binutils >= 2.25 in order for the new instructions 1783 to be used. 1784 1785endmenu # "ARMv8.1 architectural features" 1786 1787menu "ARMv8.2 architectural features" 1788 1789config AS_HAS_ARMV8_2 1790 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1791 1792config AS_HAS_SHA3 1793 def_bool $(as-instr,.arch armv8.2-a+sha3) 1794 1795config ARM64_PMEM 1796 bool "Enable support for persistent memory" 1797 select ARCH_HAS_PMEM_API 1798 select ARCH_HAS_UACCESS_FLUSHCACHE 1799 help 1800 Say Y to enable support for the persistent memory API based on the 1801 ARMv8.2 DCPoP feature. 1802 1803 The feature is detected at runtime, and the kernel will use DC CVAC 1804 operations if DC CVAP is not supported (following the behaviour of 1805 DC CVAP itself if the system does not define a point of persistence). 1806 1807config ARM64_RAS_EXTN 1808 bool "Enable support for RAS CPU Extensions" 1809 default y 1810 help 1811 CPUs that support the Reliability, Availability and Serviceability 1812 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1813 errors, classify them and report them to software. 1814 1815 On CPUs with these extensions system software can use additional 1816 barriers to determine if faults are pending and read the 1817 classification from a new set of registers. 1818 1819 Selecting this feature will allow the kernel to use these barriers 1820 and access the new registers if the system supports the extension. 1821 Platform RAS features may additionally depend on firmware support. 1822 1823config ARM64_CNP 1824 bool "Enable support for Common Not Private (CNP) translations" 1825 default y 1826 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1827 help 1828 Common Not Private (CNP) allows translation table entries to 1829 be shared between different PEs in the same inner shareable 1830 domain, so the hardware can use this fact to optimise the 1831 caching of such entries in the TLB. 1832 1833 Selecting this option allows the CNP feature to be detected 1834 at runtime, and does not affect PEs that do not implement 1835 this feature. 1836 1837endmenu # "ARMv8.2 architectural features" 1838 1839menu "ARMv8.3 architectural features" 1840 1841config ARM64_PTR_AUTH 1842 bool "Enable support for pointer authentication" 1843 default y 1844 help 1845 Pointer authentication (part of the ARMv8.3 Extensions) provides 1846 instructions for signing and authenticating pointers against secret 1847 keys, which can be used to mitigate Return Oriented Programming (ROP) 1848 and other attacks. 1849 1850 This option enables these instructions at EL0 (i.e. for userspace). 1851 Choosing this option will cause the kernel to initialise secret keys 1852 for each process at exec() time, with these keys being 1853 context-switched along with the process. 1854 1855 The feature is detected at runtime. If the feature is not present in 1856 hardware it will not be advertised to userspace/KVM guest nor will it 1857 be enabled. 1858 1859 If the feature is present on the boot CPU but not on a late CPU, then 1860 the late CPU will be parked. Also, if the boot CPU does not have 1861 address auth and the late CPU has then the late CPU will still boot 1862 but with the feature disabled. On such a system, this option should 1863 not be selected. 1864 1865config ARM64_PTR_AUTH_KERNEL 1866 bool "Use pointer authentication for kernel" 1867 default y 1868 depends on ARM64_PTR_AUTH 1869 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1870 # Modern compilers insert a .note.gnu.property section note for PAC 1871 # which is only understood by binutils starting with version 2.33.1. 1872 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1873 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1874 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1875 help 1876 If the compiler supports the -mbranch-protection or 1877 -msign-return-address flag (e.g. GCC 7 or later), then this option 1878 will cause the kernel itself to be compiled with return address 1879 protection. In this case, and if the target hardware is known to 1880 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1881 disabled with minimal loss of protection. 1882 1883 This feature works with FUNCTION_GRAPH_TRACER option only if 1884 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1885 1886config CC_HAS_BRANCH_PROT_PAC_RET 1887 # GCC 9 or later, clang 8 or later 1888 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1889 1890config CC_HAS_SIGN_RETURN_ADDRESS 1891 # GCC 7, 8 1892 def_bool $(cc-option,-msign-return-address=all) 1893 1894config AS_HAS_ARMV8_3 1895 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1896 1897config AS_HAS_CFI_NEGATE_RA_STATE 1898 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1899 1900config AS_HAS_LDAPR 1901 def_bool $(as-instr,.arch_extension rcpc) 1902 1903endmenu # "ARMv8.3 architectural features" 1904 1905menu "ARMv8.4 architectural features" 1906 1907config ARM64_AMU_EXTN 1908 bool "Enable support for the Activity Monitors Unit CPU extension" 1909 default y 1910 help 1911 The activity monitors extension is an optional extension introduced 1912 by the ARMv8.4 CPU architecture. This enables support for version 1 1913 of the activity monitors architecture, AMUv1. 1914 1915 To enable the use of this extension on CPUs that implement it, say Y. 1916 1917 Note that for architectural reasons, firmware _must_ implement AMU 1918 support when running on CPUs that present the activity monitors 1919 extension. The required support is present in: 1920 * Version 1.5 and later of the ARM Trusted Firmware 1921 1922 For kernels that have this configuration enabled but boot with broken 1923 firmware, you may need to say N here until the firmware is fixed. 1924 Otherwise you may experience firmware panics or lockups when 1925 accessing the counter registers. Even if you are not observing these 1926 symptoms, the values returned by the register reads might not 1927 correctly reflect reality. Most commonly, the value read will be 0, 1928 indicating that the counter is not enabled. 1929 1930config AS_HAS_ARMV8_4 1931 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1932 1933config ARM64_TLB_RANGE 1934 bool "Enable support for tlbi range feature" 1935 default y 1936 depends on AS_HAS_ARMV8_4 1937 help 1938 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1939 range of input addresses. 1940 1941 The feature introduces new assembly instructions, and they were 1942 support when binutils >= 2.30. 1943 1944endmenu # "ARMv8.4 architectural features" 1945 1946menu "ARMv8.5 architectural features" 1947 1948config AS_HAS_ARMV8_5 1949 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1950 1951config ARM64_BTI 1952 bool "Branch Target Identification support" 1953 default y 1954 help 1955 Branch Target Identification (part of the ARMv8.5 Extensions) 1956 provides a mechanism to limit the set of locations to which computed 1957 branch instructions such as BR or BLR can jump. 1958 1959 To make use of BTI on CPUs that support it, say Y. 1960 1961 BTI is intended to provide complementary protection to other control 1962 flow integrity protection mechanisms, such as the Pointer 1963 authentication mechanism provided as part of the ARMv8.3 Extensions. 1964 For this reason, it does not make sense to enable this option without 1965 also enabling support for pointer authentication. Thus, when 1966 enabling this option you should also select ARM64_PTR_AUTH=y. 1967 1968 Userspace binaries must also be specifically compiled to make use of 1969 this mechanism. If you say N here or the hardware does not support 1970 BTI, such binaries can still run, but you get no additional 1971 enforcement of branch destinations. 1972 1973config ARM64_BTI_KERNEL 1974 bool "Use Branch Target Identification for kernel" 1975 default y 1976 depends on ARM64_BTI 1977 depends on ARM64_PTR_AUTH_KERNEL 1978 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1979 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1980 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1981 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1982 depends on !CC_IS_GCC 1983 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1984 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1985 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1986 help 1987 Build the kernel with Branch Target Identification annotations 1988 and enable enforcement of this for kernel code. When this option 1989 is enabled and the system supports BTI all kernel code including 1990 modular code must have BTI enabled. 1991 1992config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1993 # GCC 9 or later, clang 8 or later 1994 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1995 1996config ARM64_E0PD 1997 bool "Enable support for E0PD" 1998 default y 1999 help 2000 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2001 that EL0 accesses made via TTBR1 always fault in constant time, 2002 providing similar benefits to KASLR as those provided by KPTI, but 2003 with lower overhead and without disrupting legitimate access to 2004 kernel memory such as SPE. 2005 2006 This option enables E0PD for TTBR1 where available. 2007 2008config ARM64_AS_HAS_MTE 2009 # Initial support for MTE went in binutils 2.32.0, checked with 2010 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2011 # as a late addition to the final architecture spec (LDGM/STGM) 2012 # is only supported in the newer 2.32.x and 2.33 binutils 2013 # versions, hence the extra "stgm" instruction check below. 2014 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2015 2016config ARM64_MTE 2017 bool "Memory Tagging Extension support" 2018 default y 2019 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2020 depends on AS_HAS_ARMV8_5 2021 depends on AS_HAS_LSE_ATOMICS 2022 # Required for tag checking in the uaccess routines 2023 depends on ARM64_PAN 2024 select ARCH_HAS_SUBPAGE_FAULTS 2025 select ARCH_USES_HIGH_VMA_FLAGS 2026 select ARCH_USES_PG_ARCH_X 2027 help 2028 Memory Tagging (part of the ARMv8.5 Extensions) provides 2029 architectural support for run-time, always-on detection of 2030 various classes of memory error to aid with software debugging 2031 to eliminate vulnerabilities arising from memory-unsafe 2032 languages. 2033 2034 This option enables the support for the Memory Tagging 2035 Extension at EL0 (i.e. for userspace). 2036 2037 Selecting this option allows the feature to be detected at 2038 runtime. Any secondary CPU not implementing this feature will 2039 not be allowed a late bring-up. 2040 2041 Userspace binaries that want to use this feature must 2042 explicitly opt in. The mechanism for the userspace is 2043 described in: 2044 2045 Documentation/arch/arm64/memory-tagging-extension.rst. 2046 2047endmenu # "ARMv8.5 architectural features" 2048 2049menu "ARMv8.7 architectural features" 2050 2051config ARM64_EPAN 2052 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2053 default y 2054 depends on ARM64_PAN 2055 help 2056 Enhanced Privileged Access Never (EPAN) allows Privileged 2057 Access Never to be used with Execute-only mappings. 2058 2059 The feature is detected at runtime, and will remain disabled 2060 if the cpu does not implement the feature. 2061endmenu # "ARMv8.7 architectural features" 2062 2063config ARM64_SVE 2064 bool "ARM Scalable Vector Extension support" 2065 default y 2066 help 2067 The Scalable Vector Extension (SVE) is an extension to the AArch64 2068 execution state which complements and extends the SIMD functionality 2069 of the base architecture to support much larger vectors and to enable 2070 additional vectorisation opportunities. 2071 2072 To enable use of this extension on CPUs that implement it, say Y. 2073 2074 On CPUs that support the SVE2 extensions, this option will enable 2075 those too. 2076 2077 Note that for architectural reasons, firmware _must_ implement SVE 2078 support when running on SVE capable hardware. The required support 2079 is present in: 2080 2081 * version 1.5 and later of the ARM Trusted Firmware 2082 * the AArch64 boot wrapper since commit 5e1261e08abf 2083 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2084 2085 For other firmware implementations, consult the firmware documentation 2086 or vendor. 2087 2088 If you need the kernel to boot on SVE-capable hardware with broken 2089 firmware, you may need to say N here until you get your firmware 2090 fixed. Otherwise, you may experience firmware panics or lockups when 2091 booting the kernel. If unsure and you are not observing these 2092 symptoms, you should assume that it is safe to say Y. 2093 2094config ARM64_SME 2095 bool "ARM Scalable Matrix Extension support" 2096 default y 2097 depends on ARM64_SVE 2098 help 2099 The Scalable Matrix Extension (SME) is an extension to the AArch64 2100 execution state which utilises a substantial subset of the SVE 2101 instruction set, together with the addition of new architectural 2102 register state capable of holding two dimensional matrix tiles to 2103 enable various matrix operations. 2104 2105config ARM64_PSEUDO_NMI 2106 bool "Support for NMI-like interrupts" 2107 select ARM_GIC_V3 2108 help 2109 Adds support for mimicking Non-Maskable Interrupts through the use of 2110 GIC interrupt priority. This support requires version 3 or later of 2111 ARM GIC. 2112 2113 This high priority configuration for interrupts needs to be 2114 explicitly enabled by setting the kernel parameter 2115 "irqchip.gicv3_pseudo_nmi" to 1. 2116 2117 If unsure, say N 2118 2119if ARM64_PSEUDO_NMI 2120config ARM64_DEBUG_PRIORITY_MASKING 2121 bool "Debug interrupt priority masking" 2122 help 2123 This adds runtime checks to functions enabling/disabling 2124 interrupts when using priority masking. The additional checks verify 2125 the validity of ICC_PMR_EL1 when calling concerned functions. 2126 2127 If unsure, say N 2128endif # ARM64_PSEUDO_NMI 2129 2130config RELOCATABLE 2131 bool "Build a relocatable kernel image" if EXPERT 2132 select ARCH_HAS_RELR 2133 default y 2134 help 2135 This builds the kernel as a Position Independent Executable (PIE), 2136 which retains all relocation metadata required to relocate the 2137 kernel binary at runtime to a different virtual address than the 2138 address it was linked at. 2139 Since AArch64 uses the RELA relocation format, this requires a 2140 relocation pass at runtime even if the kernel is loaded at the 2141 same address it was linked at. 2142 2143config RANDOMIZE_BASE 2144 bool "Randomize the address of the kernel image" 2145 select RELOCATABLE 2146 help 2147 Randomizes the virtual address at which the kernel image is 2148 loaded, as a security feature that deters exploit attempts 2149 relying on knowledge of the location of kernel internals. 2150 2151 It is the bootloader's job to provide entropy, by passing a 2152 random u64 value in /chosen/kaslr-seed at kernel entry. 2153 2154 When booting via the UEFI stub, it will invoke the firmware's 2155 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2156 to the kernel proper. In addition, it will randomise the physical 2157 location of the kernel Image as well. 2158 2159 If unsure, say N. 2160 2161config RANDOMIZE_MODULE_REGION_FULL 2162 bool "Randomize the module region over a 2 GB range" 2163 depends on RANDOMIZE_BASE 2164 default y 2165 help 2166 Randomizes the location of the module region inside a 2 GB window 2167 covering the core kernel. This way, it is less likely for modules 2168 to leak information about the location of core kernel data structures 2169 but it does imply that function calls between modules and the core 2170 kernel will need to be resolved via veneers in the module PLT. 2171 2172 When this option is not set, the module region will be randomized over 2173 a limited range that contains the [_stext, _etext] interval of the 2174 core kernel, so branch relocations are almost always in range unless 2175 the region is exhausted. In this particular case of region 2176 exhaustion, modules might be able to fall back to a larger 2GB area. 2177 2178config CC_HAVE_STACKPROTECTOR_SYSREG 2179 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2180 2181config STACKPROTECTOR_PER_TASK 2182 def_bool y 2183 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2184 2185config UNWIND_PATCH_PAC_INTO_SCS 2186 bool "Enable shadow call stack dynamically using code patching" 2187 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2188 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2189 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2190 depends on SHADOW_CALL_STACK 2191 select UNWIND_TABLES 2192 select DYNAMIC_SCS 2193 2194endmenu # "Kernel Features" 2195 2196menu "Boot options" 2197 2198config ARM64_ACPI_PARKING_PROTOCOL 2199 bool "Enable support for the ARM64 ACPI parking protocol" 2200 depends on ACPI 2201 help 2202 Enable support for the ARM64 ACPI parking protocol. If disabled 2203 the kernel will not allow booting through the ARM64 ACPI parking 2204 protocol even if the corresponding data is present in the ACPI 2205 MADT table. 2206 2207config CMDLINE 2208 string "Default kernel command string" 2209 default "" 2210 help 2211 Provide a set of default command-line options at build time by 2212 entering them here. As a minimum, you should specify the the 2213 root device (e.g. root=/dev/nfs). 2214 2215choice 2216 prompt "Kernel command line type" if CMDLINE != "" 2217 default CMDLINE_FROM_BOOTLOADER 2218 help 2219 Choose how the kernel will handle the provided default kernel 2220 command line string. 2221 2222config CMDLINE_FROM_BOOTLOADER 2223 bool "Use bootloader kernel arguments if available" 2224 help 2225 Uses the command-line options passed by the boot loader. If 2226 the boot loader doesn't provide any, the default kernel command 2227 string provided in CMDLINE will be used. 2228 2229config CMDLINE_FORCE 2230 bool "Always use the default kernel command string" 2231 help 2232 Always use the default kernel command string, even if the boot 2233 loader passes other arguments to the kernel. 2234 This is useful if you cannot or don't want to change the 2235 command-line options your boot loader passes to the kernel. 2236 2237endchoice 2238 2239config EFI_STUB 2240 bool 2241 2242config EFI 2243 bool "UEFI runtime support" 2244 depends on OF && !CPU_BIG_ENDIAN 2245 depends on KERNEL_MODE_NEON 2246 select ARCH_SUPPORTS_ACPI 2247 select LIBFDT 2248 select UCS2_STRING 2249 select EFI_PARAMS_FROM_FDT 2250 select EFI_RUNTIME_WRAPPERS 2251 select EFI_STUB 2252 select EFI_GENERIC_STUB 2253 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2254 default y 2255 help 2256 This option provides support for runtime services provided 2257 by UEFI firmware (such as non-volatile variables, realtime 2258 clock, and platform reset). A UEFI stub is also provided to 2259 allow the kernel to be booted as an EFI application. This 2260 is only useful on systems that have UEFI firmware. 2261 2262config DMI 2263 bool "Enable support for SMBIOS (DMI) tables" 2264 depends on EFI 2265 default y 2266 help 2267 This enables SMBIOS/DMI feature for systems. 2268 2269 This option is only useful on systems that have UEFI firmware. 2270 However, even with this option, the resultant kernel should 2271 continue to boot on existing non-UEFI platforms. 2272 2273endmenu # "Boot options" 2274 2275menu "Power management options" 2276 2277source "kernel/power/Kconfig" 2278 2279config ARCH_HIBERNATION_POSSIBLE 2280 def_bool y 2281 depends on CPU_PM 2282 2283config ARCH_HIBERNATION_HEADER 2284 def_bool y 2285 depends on HIBERNATION 2286 2287config ARCH_SUSPEND_POSSIBLE 2288 def_bool y 2289 2290endmenu # "Power management options" 2291 2292menu "CPU Power Management" 2293 2294source "drivers/cpuidle/Kconfig" 2295 2296source "drivers/cpufreq/Kconfig" 2297 2298endmenu # "CPU Power Management" 2299 2300source "drivers/acpi/Kconfig" 2301 2302source "arch/arm64/kvm/Kconfig" 2303 2304