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_TRACER 206 select HAVE_GCC_PLUGINS 207 select HAVE_HW_BREAKPOINT if PERF_EVENTS 208 select HAVE_IOREMAP_PROT 209 select HAVE_IRQ_TIME_ACCOUNTING 210 select HAVE_KVM 211 select HAVE_NMI 212 select HAVE_PERF_EVENTS 213 select HAVE_PERF_REGS 214 select HAVE_PERF_USER_STACK_DUMP 215 select HAVE_PREEMPT_DYNAMIC_KEY 216 select HAVE_REGS_AND_STACK_ACCESS_API 217 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 218 select HAVE_FUNCTION_ARG_ACCESS_API 219 select MMU_GATHER_RCU_TABLE_FREE 220 select HAVE_RSEQ 221 select HAVE_STACKPROTECTOR 222 select HAVE_SYSCALL_TRACEPOINTS 223 select HAVE_KPROBES 224 select HAVE_KRETPROBES 225 select HAVE_GENERIC_VDSO 226 select IRQ_DOMAIN 227 select IRQ_FORCED_THREADING 228 select KASAN_VMALLOC if KASAN 229 select MODULES_USE_ELF_RELA 230 select NEED_DMA_MAP_STATE 231 select NEED_SG_DMA_LENGTH 232 select OF 233 select OF_EARLY_FLATTREE 234 select PCI_DOMAINS_GENERIC if PCI 235 select PCI_ECAM if (ACPI && PCI) 236 select PCI_SYSCALL if PCI 237 select POWER_RESET 238 select POWER_SUPPLY 239 select SPARSE_IRQ 240 select SWIOTLB 241 select SYSCTL_EXCEPTION_TRACE 242 select THREAD_INFO_IN_TASK 243 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 244 select TRACE_IRQFLAGS_SUPPORT 245 select TRACE_IRQFLAGS_NMI_SUPPORT 246 select HAVE_SOFTIRQ_ON_OWN_STACK 247 help 248 ARM 64-bit (AArch64) Linux support. 249 250config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 251 def_bool CC_IS_CLANG 252 # https://github.com/ClangBuiltLinux/linux/issues/1507 253 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 254 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 255 256config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 257 def_bool CC_IS_GCC 258 depends on $(cc-option,-fpatchable-function-entry=2) 259 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 260 261config 64BIT 262 def_bool y 263 264config MMU 265 def_bool y 266 267config ARM64_PAGE_SHIFT 268 int 269 default 16 if ARM64_64K_PAGES 270 default 14 if ARM64_16K_PAGES 271 default 12 272 273config ARM64_CONT_PTE_SHIFT 274 int 275 default 5 if ARM64_64K_PAGES 276 default 7 if ARM64_16K_PAGES 277 default 4 278 279config ARM64_CONT_PMD_SHIFT 280 int 281 default 5 if ARM64_64K_PAGES 282 default 5 if ARM64_16K_PAGES 283 default 4 284 285config ARCH_MMAP_RND_BITS_MIN 286 default 14 if ARM64_64K_PAGES 287 default 16 if ARM64_16K_PAGES 288 default 18 289 290# max bits determined by the following formula: 291# VA_BITS - PAGE_SHIFT - 3 292config ARCH_MMAP_RND_BITS_MAX 293 default 19 if ARM64_VA_BITS=36 294 default 24 if ARM64_VA_BITS=39 295 default 27 if ARM64_VA_BITS=42 296 default 30 if ARM64_VA_BITS=47 297 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 298 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 299 default 33 if ARM64_VA_BITS=48 300 default 14 if ARM64_64K_PAGES 301 default 16 if ARM64_16K_PAGES 302 default 18 303 304config ARCH_MMAP_RND_COMPAT_BITS_MIN 305 default 7 if ARM64_64K_PAGES 306 default 9 if ARM64_16K_PAGES 307 default 11 308 309config ARCH_MMAP_RND_COMPAT_BITS_MAX 310 default 16 311 312config NO_IOPORT_MAP 313 def_bool y if !PCI 314 315config STACKTRACE_SUPPORT 316 def_bool y 317 318config ILLEGAL_POINTER_VALUE 319 hex 320 default 0xdead000000000000 321 322config LOCKDEP_SUPPORT 323 def_bool y 324 325config GENERIC_BUG 326 def_bool y 327 depends on BUG 328 329config GENERIC_BUG_RELATIVE_POINTERS 330 def_bool y 331 depends on GENERIC_BUG 332 333config GENERIC_HWEIGHT 334 def_bool y 335 336config GENERIC_CSUM 337 def_bool y 338 339config GENERIC_CALIBRATE_DELAY 340 def_bool y 341 342config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 343 def_bool y 344 345config SMP 346 def_bool y 347 348config KERNEL_MODE_NEON 349 def_bool y 350 351config FIX_EARLYCON_MEM 352 def_bool y 353 354config PGTABLE_LEVELS 355 int 356 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 357 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 358 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 359 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 360 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 361 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 362 363config ARCH_SUPPORTS_UPROBES 364 def_bool y 365 366config ARCH_PROC_KCORE_TEXT 367 def_bool y 368 369config BROKEN_GAS_INST 370 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 371 372config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 373 bool 374 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 375 # https://reviews.llvm.org/D75044 376 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 377 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 378 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 379 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 380 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 381 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 382 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 383 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 384 default n 385 386config KASAN_SHADOW_OFFSET 387 hex 388 depends on KASAN_GENERIC || KASAN_SW_TAGS 389 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 390 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 391 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 392 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 393 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 394 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 395 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 396 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 397 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 398 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 399 default 0xffffffffffffffff 400 401config UNWIND_TABLES 402 bool 403 404source "arch/arm64/Kconfig.platforms" 405 406menu "Kernel Features" 407 408menu "ARM errata workarounds via the alternatives framework" 409 410config ARM64_WORKAROUND_CLEAN_CACHE 411 bool 412 413config ARM64_ERRATUM_826319 414 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 415 default y 416 select ARM64_WORKAROUND_CLEAN_CACHE 417 help 418 This option adds an alternative code sequence to work around ARM 419 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 420 AXI master interface and an L2 cache. 421 422 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 423 and is unable to accept a certain write via this interface, it will 424 not progress on read data presented on the read data channel and the 425 system can deadlock. 426 427 The workaround promotes data cache clean instructions to 428 data cache clean-and-invalidate. 429 Please note that this does not necessarily enable the workaround, 430 as it depends on the alternative framework, which will only patch 431 the kernel if an affected CPU is detected. 432 433 If unsure, say Y. 434 435config ARM64_ERRATUM_827319 436 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 437 default y 438 select ARM64_WORKAROUND_CLEAN_CACHE 439 help 440 This option adds an alternative code sequence to work around ARM 441 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 442 master interface and an L2 cache. 443 444 Under certain conditions this erratum can cause a clean line eviction 445 to occur at the same time as another transaction to the same address 446 on the AMBA 5 CHI interface, which can cause data corruption if the 447 interconnect reorders the two transactions. 448 449 The workaround promotes data cache clean instructions to 450 data cache clean-and-invalidate. 451 Please note that this does not necessarily enable the workaround, 452 as it depends on the alternative framework, which will only patch 453 the kernel if an affected CPU is detected. 454 455 If unsure, say Y. 456 457config ARM64_ERRATUM_824069 458 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 459 default y 460 select ARM64_WORKAROUND_CLEAN_CACHE 461 help 462 This option adds an alternative code sequence to work around ARM 463 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 464 to a coherent interconnect. 465 466 If a Cortex-A53 processor is executing a store or prefetch for 467 write instruction at the same time as a processor in another 468 cluster is executing a cache maintenance operation to the same 469 address, then this erratum might cause a clean cache line to be 470 incorrectly marked as dirty. 471 472 The workaround promotes data cache clean instructions to 473 data cache clean-and-invalidate. 474 Please note that this option does not necessarily enable the 475 workaround, as it depends on the alternative framework, which will 476 only patch the kernel if an affected CPU is detected. 477 478 If unsure, say Y. 479 480config ARM64_ERRATUM_819472 481 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 482 default y 483 select ARM64_WORKAROUND_CLEAN_CACHE 484 help 485 This option adds an alternative code sequence to work around ARM 486 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 487 present when it is connected to a coherent interconnect. 488 489 If the processor is executing a load and store exclusive sequence at 490 the same time as a processor in another cluster is executing a cache 491 maintenance operation to the same address, then this erratum might 492 cause data corruption. 493 494 The workaround promotes data cache clean instructions to 495 data cache clean-and-invalidate. 496 Please note that this does not necessarily enable the workaround, 497 as it depends on the alternative framework, which will only patch 498 the kernel if an affected CPU is detected. 499 500 If unsure, say Y. 501 502config ARM64_ERRATUM_832075 503 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 504 default y 505 help 506 This option adds an alternative code sequence to work around ARM 507 erratum 832075 on Cortex-A57 parts up to r1p2. 508 509 Affected Cortex-A57 parts might deadlock when exclusive load/store 510 instructions to Write-Back memory are mixed with Device loads. 511 512 The workaround is to promote device loads to use Load-Acquire 513 semantics. 514 Please note that this does not necessarily enable the workaround, 515 as it depends on the alternative framework, which will only patch 516 the kernel if an affected CPU is detected. 517 518 If unsure, say Y. 519 520config ARM64_ERRATUM_834220 521 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 522 depends on KVM 523 default y 524 help 525 This option adds an alternative code sequence to work around ARM 526 erratum 834220 on Cortex-A57 parts up to r1p2. 527 528 Affected Cortex-A57 parts might report a Stage 2 translation 529 fault as the result of a Stage 1 fault for load crossing a 530 page boundary when there is a permission or device memory 531 alignment fault at Stage 1 and a translation fault at Stage 2. 532 533 The workaround is to verify that the Stage 1 translation 534 doesn't generate a fault before handling the Stage 2 fault. 535 Please note that this does not necessarily enable the workaround, 536 as it depends on the alternative framework, which will only patch 537 the kernel if an affected CPU is detected. 538 539 If unsure, say Y. 540 541config ARM64_ERRATUM_1742098 542 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 543 depends on COMPAT 544 default y 545 help 546 This option removes the AES hwcap for aarch32 user-space to 547 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 548 549 Affected parts may corrupt the AES state if an interrupt is 550 taken between a pair of AES instructions. These instructions 551 are only present if the cryptography extensions are present. 552 All software should have a fallback implementation for CPUs 553 that don't implement the cryptography extensions. 554 555 If unsure, say Y. 556 557config ARM64_ERRATUM_845719 558 bool "Cortex-A53: 845719: a load might read incorrect data" 559 depends on COMPAT 560 default y 561 help 562 This option adds an alternative code sequence to work around ARM 563 erratum 845719 on Cortex-A53 parts up to r0p4. 564 565 When running a compat (AArch32) userspace on an affected Cortex-A53 566 part, a load at EL0 from a virtual address that matches the bottom 32 567 bits of the virtual address used by a recent load at (AArch64) EL1 568 might return incorrect data. 569 570 The workaround is to write the contextidr_el1 register on exception 571 return to a 32-bit task. 572 Please note that this does not necessarily enable the workaround, 573 as it depends on the alternative framework, which will only patch 574 the kernel if an affected CPU is detected. 575 576 If unsure, say Y. 577 578config ARM64_ERRATUM_843419 579 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 580 default y 581 select ARM64_MODULE_PLTS if MODULES 582 help 583 This option links the kernel with '--fix-cortex-a53-843419' and 584 enables PLT support to replace certain ADRP instructions, which can 585 cause subsequent memory accesses to use an incorrect address on 586 Cortex-A53 parts up to r0p4. 587 588 If unsure, say Y. 589 590config ARM64_LD_HAS_FIX_ERRATUM_843419 591 def_bool $(ld-option,--fix-cortex-a53-843419) 592 593config ARM64_ERRATUM_1024718 594 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 595 default y 596 help 597 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 598 599 Affected Cortex-A55 cores (all revisions) could cause incorrect 600 update of the hardware dirty bit when the DBM/AP bits are updated 601 without a break-before-make. The workaround is to disable the usage 602 of hardware DBM locally on the affected cores. CPUs not affected by 603 this erratum will continue to use the feature. 604 605 If unsure, say Y. 606 607config ARM64_ERRATUM_1418040 608 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 609 default y 610 depends on COMPAT 611 help 612 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 613 errata 1188873 and 1418040. 614 615 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 616 cause register corruption when accessing the timer registers 617 from AArch32 userspace. 618 619 If unsure, say Y. 620 621config ARM64_WORKAROUND_SPECULATIVE_AT 622 bool 623 624config ARM64_ERRATUM_1165522 625 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 626 default y 627 select ARM64_WORKAROUND_SPECULATIVE_AT 628 help 629 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 630 631 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 632 corrupted TLBs by speculating an AT instruction during a guest 633 context switch. 634 635 If unsure, say Y. 636 637config ARM64_ERRATUM_1319367 638 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 639 default y 640 select ARM64_WORKAROUND_SPECULATIVE_AT 641 help 642 This option adds work arounds for ARM Cortex-A57 erratum 1319537 643 and A72 erratum 1319367 644 645 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 646 speculating an AT instruction during a guest context switch. 647 648 If unsure, say Y. 649 650config ARM64_ERRATUM_1530923 651 bool "Cortex-A55: 1530923: 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-A55 erratum 1530923. 656 657 Affected Cortex-A55 cores (r0p0, r0p1, 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_WORKAROUND_REPEAT_TLBI 664 bool 665 666config ARM64_ERRATUM_2441007 667 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 668 default y 669 select ARM64_WORKAROUND_REPEAT_TLBI 670 help 671 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 672 673 Under very rare circumstances, affected Cortex-A55 CPUs 674 may not handle a race between a break-before-make sequence on one 675 CPU, and another CPU accessing the same page. This could allow a 676 store to a page that has been unmapped. 677 678 Work around this by adding the affected CPUs to the list that needs 679 TLB sequences to be done twice. 680 681 If unsure, say Y. 682 683config ARM64_ERRATUM_1286807 684 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 685 default y 686 select ARM64_WORKAROUND_REPEAT_TLBI 687 help 688 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 689 690 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 691 address for a cacheable mapping of a location is being 692 accessed by a core while another core is remapping the virtual 693 address to a new physical page using the recommended 694 break-before-make sequence, then under very rare circumstances 695 TLBI+DSB completes before a read using the translation being 696 invalidated has been observed by other observers. The 697 workaround repeats the TLBI+DSB operation. 698 699config ARM64_ERRATUM_1463225 700 bool "Cortex-A76: Software Step might prevent interrupt recognition" 701 default y 702 help 703 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 704 705 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 706 of a system call instruction (SVC) can prevent recognition of 707 subsequent interrupts when software stepping is disabled in the 708 exception handler of the system call and either kernel debugging 709 is enabled or VHE is in use. 710 711 Work around the erratum by triggering a dummy step exception 712 when handling a system call from a task that is being stepped 713 in a VHE configuration of the kernel. 714 715 If unsure, say Y. 716 717config ARM64_ERRATUM_1542419 718 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 719 default y 720 help 721 This option adds a workaround for ARM Neoverse-N1 erratum 722 1542419. 723 724 Affected Neoverse-N1 cores could execute a stale instruction when 725 modified by another CPU. The workaround depends on a firmware 726 counterpart. 727 728 Workaround the issue by hiding the DIC feature from EL0. This 729 forces user-space to perform cache maintenance. 730 731 If unsure, say Y. 732 733config ARM64_ERRATUM_1508412 734 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 735 default y 736 help 737 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 738 739 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 740 of a store-exclusive or read of PAR_EL1 and a load with device or 741 non-cacheable memory attributes. The workaround depends on a firmware 742 counterpart. 743 744 KVM guests must also have the workaround implemented or they can 745 deadlock the system. 746 747 Work around the issue by inserting DMB SY barriers around PAR_EL1 748 register reads and warning KVM users. The DMB barrier is sufficient 749 to prevent a speculative PAR_EL1 read. 750 751 If unsure, say Y. 752 753config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 754 bool 755 756config ARM64_ERRATUM_2051678 757 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 758 default y 759 help 760 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 761 Affected Cortex-A510 might not respect the ordering rules for 762 hardware update of the page table's dirty bit. The workaround 763 is to not enable the feature on affected CPUs. 764 765 If unsure, say Y. 766 767config ARM64_ERRATUM_2077057 768 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 769 default y 770 help 771 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 772 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 773 expected, but a Pointer Authentication trap is taken instead. The 774 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 775 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 776 777 This can only happen when EL2 is stepping EL1. 778 779 When these conditions occur, the SPSR_EL2 value is unchanged from the 780 previous guest entry, and can be restored from the in-memory copy. 781 782 If unsure, say Y. 783 784config ARM64_ERRATUM_2658417 785 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 786 default y 787 help 788 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 789 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 790 BFMMLA or VMMLA instructions in rare circumstances when a pair of 791 A510 CPUs are using shared neon hardware. As the sharing is not 792 discoverable by the kernel, hide the BF16 HWCAP to indicate that 793 user-space should not be using these instructions. 794 795 If unsure, say Y. 796 797config ARM64_ERRATUM_2119858 798 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 799 default y 800 depends on CORESIGHT_TRBE 801 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 802 help 803 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 804 805 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 806 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 807 the event of a WRAP event. 808 809 Work around the issue by always making sure we move the TRBPTR_EL1 by 810 256 bytes before enabling the buffer and filling the first 256 bytes of 811 the buffer with ETM ignore packets upon disabling. 812 813 If unsure, say Y. 814 815config ARM64_ERRATUM_2139208 816 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 817 default y 818 depends on CORESIGHT_TRBE 819 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 820 help 821 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 822 823 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 824 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 825 the event of a WRAP event. 826 827 Work around the issue by always making sure we move the TRBPTR_EL1 by 828 256 bytes before enabling the buffer and filling the first 256 bytes of 829 the buffer with ETM ignore packets upon disabling. 830 831 If unsure, say Y. 832 833config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 834 bool 835 836config ARM64_ERRATUM_2054223 837 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 838 default y 839 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 840 help 841 Enable workaround for ARM Cortex-A710 erratum 2054223 842 843 Affected cores may fail to flush the trace data on a TSB instruction, when 844 the PE is in trace prohibited state. This will cause losing a few bytes 845 of the trace cached. 846 847 Workaround is to issue two TSB consecutively on affected cores. 848 849 If unsure, say Y. 850 851config ARM64_ERRATUM_2067961 852 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 853 default y 854 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 855 help 856 Enable workaround for ARM Neoverse-N2 erratum 2067961 857 858 Affected cores may fail to flush the trace data on a TSB instruction, when 859 the PE is in trace prohibited state. This will cause losing a few bytes 860 of the trace cached. 861 862 Workaround is to issue two TSB consecutively on affected cores. 863 864 If unsure, say Y. 865 866config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 867 bool 868 869config ARM64_ERRATUM_2253138 870 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 871 depends on CORESIGHT_TRBE 872 default y 873 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 874 help 875 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 876 877 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 878 for TRBE. Under some conditions, the TRBE might generate a write to the next 879 virtually addressed page following the last page of the TRBE address space 880 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 881 882 Work around this in the driver by always making sure that there is a 883 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 884 885 If unsure, say Y. 886 887config ARM64_ERRATUM_2224489 888 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 889 depends on CORESIGHT_TRBE 890 default y 891 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 892 help 893 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 894 895 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 896 for TRBE. Under some conditions, the TRBE might generate a write to the next 897 virtually addressed page following the last page of the TRBE address space 898 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 899 900 Work around this in the driver by always making sure that there is a 901 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 902 903 If unsure, say Y. 904 905config ARM64_ERRATUM_2441009 906 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 907 default y 908 select ARM64_WORKAROUND_REPEAT_TLBI 909 help 910 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 911 912 Under very rare circumstances, affected Cortex-A510 CPUs 913 may not handle a race between a break-before-make sequence on one 914 CPU, and another CPU accessing the same page. This could allow a 915 store to a page that has been unmapped. 916 917 Work around this by adding the affected CPUs to the list that needs 918 TLB sequences to be done twice. 919 920 If unsure, say Y. 921 922config ARM64_ERRATUM_2064142 923 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 924 depends on CORESIGHT_TRBE 925 default y 926 help 927 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 928 929 Affected Cortex-A510 core might fail to write into system registers after the 930 TRBE has been disabled. Under some conditions after the TRBE has been disabled 931 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 932 and TRBTRG_EL1 will be ignored and will not be effected. 933 934 Work around this in the driver by executing TSB CSYNC and DSB after collection 935 is stopped and before performing a system register write to one of the affected 936 registers. 937 938 If unsure, say Y. 939 940config ARM64_ERRATUM_2038923 941 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 942 depends on CORESIGHT_TRBE 943 default y 944 help 945 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 946 947 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 948 prohibited within the CPU. As a result, the trace buffer or trace buffer state 949 might be corrupted. This happens after TRBE buffer has been enabled by setting 950 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 951 execution changes from a context, in which trace is prohibited to one where it 952 isn't, or vice versa. In these mentioned conditions, the view of whether trace 953 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 954 the trace buffer state might be corrupted. 955 956 Work around this in the driver by preventing an inconsistent view of whether the 957 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 958 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 959 two ISB instructions if no ERET is to take place. 960 961 If unsure, say Y. 962 963config ARM64_ERRATUM_1902691 964 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 965 depends on CORESIGHT_TRBE 966 default y 967 help 968 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 969 970 Affected Cortex-A510 core might cause trace data corruption, when being written 971 into the memory. Effectively TRBE is broken and hence cannot be used to capture 972 trace data. 973 974 Work around this problem in the driver by just preventing TRBE initialization on 975 affected cpus. The firmware must have disabled the access to TRBE for the kernel 976 on such implementations. This will cover the kernel for any firmware that doesn't 977 do this already. 978 979 If unsure, say Y. 980 981config ARM64_ERRATUM_2457168 982 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 983 depends on ARM64_AMU_EXTN 984 default y 985 help 986 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 987 988 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 989 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 990 incorrectly giving a significantly higher output value. 991 992 Work around this problem by returning 0 when reading the affected counter in 993 key locations that results in disabling all users of this counter. This effect 994 is the same to firmware disabling affected counters. 995 996 If unsure, say Y. 997 998config ARM64_ERRATUM_2645198 999 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1000 default y 1001 help 1002 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1003 1004 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1005 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1006 next instruction abort caused by permission fault. 1007 1008 Only user-space does executable to non-executable permission transition via 1009 mprotect() system call. Workaround the problem by doing a break-before-make 1010 TLB invalidation, for all changes to executable user space mappings. 1011 1012 If unsure, say Y. 1013 1014config CAVIUM_ERRATUM_22375 1015 bool "Cavium erratum 22375, 24313" 1016 default y 1017 help 1018 Enable workaround for errata 22375 and 24313. 1019 1020 This implements two gicv3-its errata workarounds for ThunderX. Both 1021 with a small impact affecting only ITS table allocation. 1022 1023 erratum 22375: only alloc 8MB table size 1024 erratum 24313: ignore memory access type 1025 1026 The fixes are in ITS initialization and basically ignore memory access 1027 type and table size provided by the TYPER and BASER registers. 1028 1029 If unsure, say Y. 1030 1031config CAVIUM_ERRATUM_23144 1032 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1033 depends on NUMA 1034 default y 1035 help 1036 ITS SYNC command hang for cross node io and collections/cpu mapping. 1037 1038 If unsure, say Y. 1039 1040config CAVIUM_ERRATUM_23154 1041 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1042 default y 1043 help 1044 The ThunderX GICv3 implementation requires a modified version for 1045 reading the IAR status to ensure data synchronization 1046 (access to icc_iar1_el1 is not sync'ed before and after). 1047 1048 It also suffers from erratum 38545 (also present on Marvell's 1049 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1050 spuriously presented to the CPU interface. 1051 1052 If unsure, say Y. 1053 1054config CAVIUM_ERRATUM_27456 1055 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1056 default y 1057 help 1058 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1059 instructions may cause the icache to become corrupted if it 1060 contains data for a non-current ASID. The fix is to 1061 invalidate the icache when changing the mm context. 1062 1063 If unsure, say Y. 1064 1065config CAVIUM_ERRATUM_30115 1066 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1067 default y 1068 help 1069 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1070 1.2, and T83 Pass 1.0, KVM guest execution may disable 1071 interrupts in host. Trapping both GICv3 group-0 and group-1 1072 accesses sidesteps the issue. 1073 1074 If unsure, say Y. 1075 1076config CAVIUM_TX2_ERRATUM_219 1077 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1078 default y 1079 help 1080 On Cavium ThunderX2, a load, store or prefetch instruction between a 1081 TTBR update and the corresponding context synchronizing operation can 1082 cause a spurious Data Abort to be delivered to any hardware thread in 1083 the CPU core. 1084 1085 Work around the issue by avoiding the problematic code sequence and 1086 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1087 trap handler performs the corresponding register access, skips the 1088 instruction and ensures context synchronization by virtue of the 1089 exception return. 1090 1091 If unsure, say Y. 1092 1093config FUJITSU_ERRATUM_010001 1094 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1095 default y 1096 help 1097 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1098 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1099 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1100 This fault occurs under a specific hardware condition when a 1101 load/store instruction performs an address translation using: 1102 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1103 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1104 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1105 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1106 1107 The workaround is to ensure these bits are clear in TCR_ELx. 1108 The workaround only affects the Fujitsu-A64FX. 1109 1110 If unsure, say Y. 1111 1112config HISILICON_ERRATUM_161600802 1113 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1114 default y 1115 help 1116 The HiSilicon Hip07 SoC uses the wrong redistributor base 1117 when issued ITS commands such as VMOVP and VMAPP, and requires 1118 a 128kB offset to be applied to the target address in this commands. 1119 1120 If unsure, say Y. 1121 1122config QCOM_FALKOR_ERRATUM_1003 1123 bool "Falkor E1003: Incorrect translation due to ASID change" 1124 default y 1125 help 1126 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1127 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1128 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1129 then only for entries in the walk cache, since the leaf translation 1130 is unchanged. Work around the erratum by invalidating the walk cache 1131 entries for the trampoline before entering the kernel proper. 1132 1133config QCOM_FALKOR_ERRATUM_1009 1134 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1135 default y 1136 select ARM64_WORKAROUND_REPEAT_TLBI 1137 help 1138 On Falkor v1, the CPU may prematurely complete a DSB following a 1139 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1140 one more time to fix the issue. 1141 1142 If unsure, say Y. 1143 1144config QCOM_QDF2400_ERRATUM_0065 1145 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1146 default y 1147 help 1148 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1149 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1150 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1151 1152 If unsure, say Y. 1153 1154config QCOM_FALKOR_ERRATUM_E1041 1155 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1156 default y 1157 help 1158 Falkor CPU may speculatively fetch instructions from an improper 1159 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1160 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1161 1162 If unsure, say Y. 1163 1164config NVIDIA_CARMEL_CNP_ERRATUM 1165 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1166 default y 1167 help 1168 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1169 invalidate shared TLB entries installed by a different core, as it would 1170 on standard ARM cores. 1171 1172 If unsure, say Y. 1173 1174config ROCKCHIP_ERRATUM_3588001 1175 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1176 default y 1177 help 1178 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1179 This means, that its sharability feature may not be used, even though it 1180 is supported by the IP itself. 1181 1182 If unsure, say Y. 1183 1184config SOCIONEXT_SYNQUACER_PREITS 1185 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1186 default y 1187 help 1188 Socionext Synquacer SoCs implement a separate h/w block to generate 1189 MSI doorbell writes with non-zero values for the device ID. 1190 1191 If unsure, say Y. 1192 1193endmenu # "ARM errata workarounds via the alternatives framework" 1194 1195choice 1196 prompt "Page size" 1197 default ARM64_4K_PAGES 1198 help 1199 Page size (translation granule) configuration. 1200 1201config ARM64_4K_PAGES 1202 bool "4KB" 1203 help 1204 This feature enables 4KB pages support. 1205 1206config ARM64_16K_PAGES 1207 bool "16KB" 1208 help 1209 The system will use 16KB pages support. AArch32 emulation 1210 requires applications compiled with 16K (or a multiple of 16K) 1211 aligned segments. 1212 1213config ARM64_64K_PAGES 1214 bool "64KB" 1215 help 1216 This feature enables 64KB pages support (4KB by default) 1217 allowing only two levels of page tables and faster TLB 1218 look-up. AArch32 emulation requires applications compiled 1219 with 64K aligned segments. 1220 1221endchoice 1222 1223choice 1224 prompt "Virtual address space size" 1225 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1226 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1227 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1228 help 1229 Allows choosing one of multiple possible virtual address 1230 space sizes. The level of translation table is determined by 1231 a combination of page size and virtual address space size. 1232 1233config ARM64_VA_BITS_36 1234 bool "36-bit" if EXPERT 1235 depends on ARM64_16K_PAGES 1236 1237config ARM64_VA_BITS_39 1238 bool "39-bit" 1239 depends on ARM64_4K_PAGES 1240 1241config ARM64_VA_BITS_42 1242 bool "42-bit" 1243 depends on ARM64_64K_PAGES 1244 1245config ARM64_VA_BITS_47 1246 bool "47-bit" 1247 depends on ARM64_16K_PAGES 1248 1249config ARM64_VA_BITS_48 1250 bool "48-bit" 1251 1252config ARM64_VA_BITS_52 1253 bool "52-bit" 1254 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1255 help 1256 Enable 52-bit virtual addressing for userspace when explicitly 1257 requested via a hint to mmap(). The kernel will also use 52-bit 1258 virtual addresses for its own mappings (provided HW support for 1259 this feature is available, otherwise it reverts to 48-bit). 1260 1261 NOTE: Enabling 52-bit virtual addressing in conjunction with 1262 ARMv8.3 Pointer Authentication will result in the PAC being 1263 reduced from 7 bits to 3 bits, which may have a significant 1264 impact on its susceptibility to brute-force attacks. 1265 1266 If unsure, select 48-bit virtual addressing instead. 1267 1268endchoice 1269 1270config ARM64_FORCE_52BIT 1271 bool "Force 52-bit virtual addresses for userspace" 1272 depends on ARM64_VA_BITS_52 && EXPERT 1273 help 1274 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1275 to maintain compatibility with older software by providing 48-bit VAs 1276 unless a hint is supplied to mmap. 1277 1278 This configuration option disables the 48-bit compatibility logic, and 1279 forces all userspace addresses to be 52-bit on HW that supports it. One 1280 should only enable this configuration option for stress testing userspace 1281 memory management code. If unsure say N here. 1282 1283config ARM64_VA_BITS 1284 int 1285 default 36 if ARM64_VA_BITS_36 1286 default 39 if ARM64_VA_BITS_39 1287 default 42 if ARM64_VA_BITS_42 1288 default 47 if ARM64_VA_BITS_47 1289 default 48 if ARM64_VA_BITS_48 1290 default 52 if ARM64_VA_BITS_52 1291 1292choice 1293 prompt "Physical address space size" 1294 default ARM64_PA_BITS_48 1295 help 1296 Choose the maximum physical address range that the kernel will 1297 support. 1298 1299config ARM64_PA_BITS_48 1300 bool "48-bit" 1301 1302config ARM64_PA_BITS_52 1303 bool "52-bit (ARMv8.2)" 1304 depends on ARM64_64K_PAGES 1305 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1306 help 1307 Enable support for a 52-bit physical address space, introduced as 1308 part of the ARMv8.2-LPA extension. 1309 1310 With this enabled, the kernel will also continue to work on CPUs that 1311 do not support ARMv8.2-LPA, but with some added memory overhead (and 1312 minor performance overhead). 1313 1314endchoice 1315 1316config ARM64_PA_BITS 1317 int 1318 default 48 if ARM64_PA_BITS_48 1319 default 52 if ARM64_PA_BITS_52 1320 1321choice 1322 prompt "Endianness" 1323 default CPU_LITTLE_ENDIAN 1324 help 1325 Select the endianness of data accesses performed by the CPU. Userspace 1326 applications will need to be compiled and linked for the endianness 1327 that is selected here. 1328 1329config CPU_BIG_ENDIAN 1330 bool "Build big-endian kernel" 1331 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1332 help 1333 Say Y if you plan on running a kernel with a big-endian userspace. 1334 1335config CPU_LITTLE_ENDIAN 1336 bool "Build little-endian kernel" 1337 help 1338 Say Y if you plan on running a kernel with a little-endian userspace. 1339 This is usually the case for distributions targeting arm64. 1340 1341endchoice 1342 1343config SCHED_MC 1344 bool "Multi-core scheduler support" 1345 help 1346 Multi-core scheduler support improves the CPU scheduler's decision 1347 making when dealing with multi-core CPU chips at a cost of slightly 1348 increased overhead in some places. If unsure say N here. 1349 1350config SCHED_CLUSTER 1351 bool "Cluster scheduler support" 1352 help 1353 Cluster scheduler support improves the CPU scheduler's decision 1354 making when dealing with machines that have clusters of CPUs. 1355 Cluster usually means a couple of CPUs which are placed closely 1356 by sharing mid-level caches, last-level cache tags or internal 1357 busses. 1358 1359config SCHED_SMT 1360 bool "SMT scheduler support" 1361 help 1362 Improves the CPU scheduler's decision making when dealing with 1363 MultiThreading at a cost of slightly increased overhead in some 1364 places. If unsure say N here. 1365 1366config NR_CPUS 1367 int "Maximum number of CPUs (2-4096)" 1368 range 2 4096 1369 default "256" 1370 1371config HOTPLUG_CPU 1372 bool "Support for hot-pluggable CPUs" 1373 select GENERIC_IRQ_MIGRATION 1374 help 1375 Say Y here to experiment with turning CPUs off and on. CPUs 1376 can be controlled through /sys/devices/system/cpu. 1377 1378# Common NUMA Features 1379config NUMA 1380 bool "NUMA Memory Allocation and Scheduler Support" 1381 select GENERIC_ARCH_NUMA 1382 select ACPI_NUMA if ACPI 1383 select OF_NUMA 1384 select HAVE_SETUP_PER_CPU_AREA 1385 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1386 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1387 select USE_PERCPU_NUMA_NODE_ID 1388 help 1389 Enable NUMA (Non-Uniform Memory Access) support. 1390 1391 The kernel will try to allocate memory used by a CPU on the 1392 local memory of the CPU and add some more 1393 NUMA awareness to the kernel. 1394 1395config NODES_SHIFT 1396 int "Maximum NUMA Nodes (as a power of 2)" 1397 range 1 10 1398 default "4" 1399 depends on NUMA 1400 help 1401 Specify the maximum number of NUMA Nodes available on the target 1402 system. Increases memory reserved to accommodate various tables. 1403 1404source "kernel/Kconfig.hz" 1405 1406config ARCH_SPARSEMEM_ENABLE 1407 def_bool y 1408 select SPARSEMEM_VMEMMAP_ENABLE 1409 select SPARSEMEM_VMEMMAP 1410 1411config HW_PERF_EVENTS 1412 def_bool y 1413 depends on ARM_PMU 1414 1415# Supported by clang >= 7.0 or GCC >= 12.0.0 1416config CC_HAVE_SHADOW_CALL_STACK 1417 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1418 1419config PARAVIRT 1420 bool "Enable paravirtualization code" 1421 help 1422 This changes the kernel so it can modify itself when it is run 1423 under a hypervisor, potentially improving performance significantly 1424 over full virtualization. 1425 1426config PARAVIRT_TIME_ACCOUNTING 1427 bool "Paravirtual steal time accounting" 1428 select PARAVIRT 1429 help 1430 Select this option to enable fine granularity task steal time 1431 accounting. Time spent executing other tasks in parallel with 1432 the current vCPU is discounted from the vCPU power. To account for 1433 that, there can be a small performance impact. 1434 1435 If in doubt, say N here. 1436 1437config KEXEC 1438 depends on PM_SLEEP_SMP 1439 select KEXEC_CORE 1440 bool "kexec system call" 1441 help 1442 kexec is a system call that implements the ability to shutdown your 1443 current kernel, and to start another kernel. It is like a reboot 1444 but it is independent of the system firmware. And like a reboot 1445 you can start any kernel with it, not just Linux. 1446 1447config KEXEC_FILE 1448 bool "kexec file based system call" 1449 select KEXEC_CORE 1450 select HAVE_IMA_KEXEC if IMA 1451 help 1452 This is new version of kexec system call. This system call is 1453 file based and takes file descriptors as system call argument 1454 for kernel and initramfs as opposed to list of segments as 1455 accepted by previous system call. 1456 1457config KEXEC_SIG 1458 bool "Verify kernel signature during kexec_file_load() syscall" 1459 depends on KEXEC_FILE 1460 help 1461 Select this option to verify a signature with loaded kernel 1462 image. If configured, any attempt of loading a image without 1463 valid signature will fail. 1464 1465 In addition to that option, you need to enable signature 1466 verification for the corresponding kernel image type being 1467 loaded in order for this to work. 1468 1469config KEXEC_IMAGE_VERIFY_SIG 1470 bool "Enable Image signature verification support" 1471 default y 1472 depends on KEXEC_SIG 1473 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1474 help 1475 Enable Image signature verification support. 1476 1477comment "Support for PE file signature verification disabled" 1478 depends on KEXEC_SIG 1479 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1480 1481config CRASH_DUMP 1482 bool "Build kdump crash kernel" 1483 help 1484 Generate crash dump after being started by kexec. This should 1485 be normally only set in special crash dump kernels which are 1486 loaded in the main kernel with kexec-tools into a specially 1487 reserved region and then later executed after a crash by 1488 kdump/kexec. 1489 1490 For more details see Documentation/admin-guide/kdump/kdump.rst 1491 1492config TRANS_TABLE 1493 def_bool y 1494 depends on HIBERNATION || KEXEC_CORE 1495 1496config XEN_DOM0 1497 def_bool y 1498 depends on XEN 1499 1500config XEN 1501 bool "Xen guest support on ARM64" 1502 depends on ARM64 && OF 1503 select SWIOTLB_XEN 1504 select PARAVIRT 1505 help 1506 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1507 1508# include/linux/mmzone.h requires the following to be true: 1509# 1510# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1511# 1512# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1513# 1514# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1515# ----+-------------------+--------------+-----------------+--------------------+ 1516# 4K | 27 | 12 | 15 | 10 | 1517# 16K | 27 | 14 | 13 | 11 | 1518# 64K | 29 | 16 | 13 | 13 | 1519config ARCH_FORCE_MAX_ORDER 1520 int "Order of maximal physically contiguous allocations" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES) 1521 default "13" if ARM64_64K_PAGES 1522 default "11" if ARM64_16K_PAGES 1523 default "10" 1524 help 1525 The kernel page allocator limits the size of maximal physically 1526 contiguous allocations. The limit is called MAX_ORDER and it 1527 defines the maximal power of two of number of pages that can be 1528 allocated as a single contiguous block. This option allows 1529 overriding the default setting when ability to allocate very 1530 large blocks of physically contiguous memory is required. 1531 1532 The maximal size of allocation cannot exceed the size of the 1533 section, so the value of MAX_ORDER should satisfy 1534 1535 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1536 1537 Don't change if unsure. 1538 1539config UNMAP_KERNEL_AT_EL0 1540 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1541 default y 1542 help 1543 Speculation attacks against some high-performance processors can 1544 be used to bypass MMU permission checks and leak kernel data to 1545 userspace. This can be defended against by unmapping the kernel 1546 when running in userspace, mapping it back in on exception entry 1547 via a trampoline page in the vector table. 1548 1549 If unsure, say Y. 1550 1551config MITIGATE_SPECTRE_BRANCH_HISTORY 1552 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1553 default y 1554 help 1555 Speculation attacks against some high-performance processors can 1556 make use of branch history to influence future speculation. 1557 When taking an exception from user-space, a sequence of branches 1558 or a firmware call overwrites the branch history. 1559 1560config RODATA_FULL_DEFAULT_ENABLED 1561 bool "Apply r/o permissions of VM areas also to their linear aliases" 1562 default y 1563 help 1564 Apply read-only attributes of VM areas to the linear alias of 1565 the backing pages as well. This prevents code or read-only data 1566 from being modified (inadvertently or intentionally) via another 1567 mapping of the same memory page. This additional enhancement can 1568 be turned off at runtime by passing rodata=[off|on] (and turned on 1569 with rodata=full if this option is set to 'n') 1570 1571 This requires the linear region to be mapped down to pages, 1572 which may adversely affect performance in some cases. 1573 1574config ARM64_SW_TTBR0_PAN 1575 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1576 help 1577 Enabling this option prevents the kernel from accessing 1578 user-space memory directly by pointing TTBR0_EL1 to a reserved 1579 zeroed area and reserved ASID. The user access routines 1580 restore the valid TTBR0_EL1 temporarily. 1581 1582config ARM64_TAGGED_ADDR_ABI 1583 bool "Enable the tagged user addresses syscall ABI" 1584 default y 1585 help 1586 When this option is enabled, user applications can opt in to a 1587 relaxed ABI via prctl() allowing tagged addresses to be passed 1588 to system calls as pointer arguments. For details, see 1589 Documentation/arm64/tagged-address-abi.rst. 1590 1591menuconfig COMPAT 1592 bool "Kernel support for 32-bit EL0" 1593 depends on ARM64_4K_PAGES || EXPERT 1594 select HAVE_UID16 1595 select OLD_SIGSUSPEND3 1596 select COMPAT_OLD_SIGACTION 1597 help 1598 This option enables support for a 32-bit EL0 running under a 64-bit 1599 kernel at EL1. AArch32-specific components such as system calls, 1600 the user helper functions, VFP support and the ptrace interface are 1601 handled appropriately by the kernel. 1602 1603 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1604 that you will only be able to execute AArch32 binaries that were compiled 1605 with page size aligned segments. 1606 1607 If you want to execute 32-bit userspace applications, say Y. 1608 1609if COMPAT 1610 1611config KUSER_HELPERS 1612 bool "Enable kuser helpers page for 32-bit applications" 1613 default y 1614 help 1615 Warning: disabling this option may break 32-bit user programs. 1616 1617 Provide kuser helpers to compat tasks. The kernel provides 1618 helper code to userspace in read only form at a fixed location 1619 to allow userspace to be independent of the CPU type fitted to 1620 the system. This permits binaries to be run on ARMv4 through 1621 to ARMv8 without modification. 1622 1623 See Documentation/arm/kernel_user_helpers.rst for details. 1624 1625 However, the fixed address nature of these helpers can be used 1626 by ROP (return orientated programming) authors when creating 1627 exploits. 1628 1629 If all of the binaries and libraries which run on your platform 1630 are built specifically for your platform, and make no use of 1631 these helpers, then you can turn this option off to hinder 1632 such exploits. However, in that case, if a binary or library 1633 relying on those helpers is run, it will not function correctly. 1634 1635 Say N here only if you are absolutely certain that you do not 1636 need these helpers; otherwise, the safe option is to say Y. 1637 1638config COMPAT_VDSO 1639 bool "Enable vDSO for 32-bit applications" 1640 depends on !CPU_BIG_ENDIAN 1641 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1642 select GENERIC_COMPAT_VDSO 1643 default y 1644 help 1645 Place in the process address space of 32-bit applications an 1646 ELF shared object providing fast implementations of gettimeofday 1647 and clock_gettime. 1648 1649 You must have a 32-bit build of glibc 2.22 or later for programs 1650 to seamlessly take advantage of this. 1651 1652config THUMB2_COMPAT_VDSO 1653 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1654 depends on COMPAT_VDSO 1655 default y 1656 help 1657 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1658 otherwise with '-marm'. 1659 1660config COMPAT_ALIGNMENT_FIXUPS 1661 bool "Fix up misaligned multi-word loads and stores in user space" 1662 1663menuconfig ARMV8_DEPRECATED 1664 bool "Emulate deprecated/obsolete ARMv8 instructions" 1665 depends on SYSCTL 1666 help 1667 Legacy software support may require certain instructions 1668 that have been deprecated or obsoleted in the architecture. 1669 1670 Enable this config to enable selective emulation of these 1671 features. 1672 1673 If unsure, say Y 1674 1675if ARMV8_DEPRECATED 1676 1677config SWP_EMULATION 1678 bool "Emulate SWP/SWPB instructions" 1679 help 1680 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1681 they are always undefined. Say Y here to enable software 1682 emulation of these instructions for userspace using LDXR/STXR. 1683 This feature can be controlled at runtime with the abi.swp 1684 sysctl which is disabled by default. 1685 1686 In some older versions of glibc [<=2.8] SWP is used during futex 1687 trylock() operations with the assumption that the code will not 1688 be preempted. This invalid assumption may be more likely to fail 1689 with SWP emulation enabled, leading to deadlock of the user 1690 application. 1691 1692 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1693 on an external transaction monitoring block called a global 1694 monitor to maintain update atomicity. If your system does not 1695 implement a global monitor, this option can cause programs that 1696 perform SWP operations to uncached memory to deadlock. 1697 1698 If unsure, say Y 1699 1700config CP15_BARRIER_EMULATION 1701 bool "Emulate CP15 Barrier instructions" 1702 help 1703 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1704 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1705 strongly recommended to use the ISB, DSB, and DMB 1706 instructions instead. 1707 1708 Say Y here to enable software emulation of these 1709 instructions for AArch32 userspace code. When this option is 1710 enabled, CP15 barrier usage is traced which can help 1711 identify software that needs updating. This feature can be 1712 controlled at runtime with the abi.cp15_barrier sysctl. 1713 1714 If unsure, say Y 1715 1716config SETEND_EMULATION 1717 bool "Emulate SETEND instruction" 1718 help 1719 The SETEND instruction alters the data-endianness of the 1720 AArch32 EL0, and is deprecated in ARMv8. 1721 1722 Say Y here to enable software emulation of the instruction 1723 for AArch32 userspace code. This feature can be controlled 1724 at runtime with the abi.setend sysctl. 1725 1726 Note: All the cpus on the system must have mixed endian support at EL0 1727 for this feature to be enabled. If a new CPU - which doesn't support mixed 1728 endian - is hotplugged in after this feature has been enabled, there could 1729 be unexpected results in the applications. 1730 1731 If unsure, say Y 1732endif # ARMV8_DEPRECATED 1733 1734endif # COMPAT 1735 1736menu "ARMv8.1 architectural features" 1737 1738config ARM64_HW_AFDBM 1739 bool "Support for hardware updates of the Access and Dirty page flags" 1740 default y 1741 help 1742 The ARMv8.1 architecture extensions introduce support for 1743 hardware updates of the access and dirty information in page 1744 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1745 capable processors, accesses to pages with PTE_AF cleared will 1746 set this bit instead of raising an access flag fault. 1747 Similarly, writes to read-only pages with the DBM bit set will 1748 clear the read-only bit (AP[2]) instead of raising a 1749 permission fault. 1750 1751 Kernels built with this configuration option enabled continue 1752 to work on pre-ARMv8.1 hardware and the performance impact is 1753 minimal. If unsure, say Y. 1754 1755config ARM64_PAN 1756 bool "Enable support for Privileged Access Never (PAN)" 1757 default y 1758 help 1759 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1760 prevents the kernel or hypervisor from accessing user-space (EL0) 1761 memory directly. 1762 1763 Choosing this option will cause any unprotected (not using 1764 copy_to_user et al) memory access to fail with a permission fault. 1765 1766 The feature is detected at runtime, and will remain as a 'nop' 1767 instruction if the cpu does not implement the feature. 1768 1769config AS_HAS_LDAPR 1770 def_bool $(as-instr,.arch_extension rcpc) 1771 1772config AS_HAS_LSE_ATOMICS 1773 def_bool $(as-instr,.arch_extension lse) 1774 1775config ARM64_LSE_ATOMICS 1776 bool 1777 default ARM64_USE_LSE_ATOMICS 1778 depends on AS_HAS_LSE_ATOMICS 1779 1780config ARM64_USE_LSE_ATOMICS 1781 bool "Atomic instructions" 1782 default y 1783 help 1784 As part of the Large System Extensions, ARMv8.1 introduces new 1785 atomic instructions that are designed specifically to scale in 1786 very large systems. 1787 1788 Say Y here to make use of these instructions for the in-kernel 1789 atomic routines. This incurs a small overhead on CPUs that do 1790 not support these instructions and requires the kernel to be 1791 built with binutils >= 2.25 in order for the new instructions 1792 to be used. 1793 1794endmenu # "ARMv8.1 architectural features" 1795 1796menu "ARMv8.2 architectural features" 1797 1798config AS_HAS_ARMV8_2 1799 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1800 1801config AS_HAS_SHA3 1802 def_bool $(as-instr,.arch armv8.2-a+sha3) 1803 1804config ARM64_PMEM 1805 bool "Enable support for persistent memory" 1806 select ARCH_HAS_PMEM_API 1807 select ARCH_HAS_UACCESS_FLUSHCACHE 1808 help 1809 Say Y to enable support for the persistent memory API based on the 1810 ARMv8.2 DCPoP feature. 1811 1812 The feature is detected at runtime, and the kernel will use DC CVAC 1813 operations if DC CVAP is not supported (following the behaviour of 1814 DC CVAP itself if the system does not define a point of persistence). 1815 1816config ARM64_RAS_EXTN 1817 bool "Enable support for RAS CPU Extensions" 1818 default y 1819 help 1820 CPUs that support the Reliability, Availability and Serviceability 1821 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1822 errors, classify them and report them to software. 1823 1824 On CPUs with these extensions system software can use additional 1825 barriers to determine if faults are pending and read the 1826 classification from a new set of registers. 1827 1828 Selecting this feature will allow the kernel to use these barriers 1829 and access the new registers if the system supports the extension. 1830 Platform RAS features may additionally depend on firmware support. 1831 1832config ARM64_CNP 1833 bool "Enable support for Common Not Private (CNP) translations" 1834 default y 1835 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1836 help 1837 Common Not Private (CNP) allows translation table entries to 1838 be shared between different PEs in the same inner shareable 1839 domain, so the hardware can use this fact to optimise the 1840 caching of such entries in the TLB. 1841 1842 Selecting this option allows the CNP feature to be detected 1843 at runtime, and does not affect PEs that do not implement 1844 this feature. 1845 1846endmenu # "ARMv8.2 architectural features" 1847 1848menu "ARMv8.3 architectural features" 1849 1850config ARM64_PTR_AUTH 1851 bool "Enable support for pointer authentication" 1852 default y 1853 help 1854 Pointer authentication (part of the ARMv8.3 Extensions) provides 1855 instructions for signing and authenticating pointers against secret 1856 keys, which can be used to mitigate Return Oriented Programming (ROP) 1857 and other attacks. 1858 1859 This option enables these instructions at EL0 (i.e. for userspace). 1860 Choosing this option will cause the kernel to initialise secret keys 1861 for each process at exec() time, with these keys being 1862 context-switched along with the process. 1863 1864 The feature is detected at runtime. If the feature is not present in 1865 hardware it will not be advertised to userspace/KVM guest nor will it 1866 be enabled. 1867 1868 If the feature is present on the boot CPU but not on a late CPU, then 1869 the late CPU will be parked. Also, if the boot CPU does not have 1870 address auth and the late CPU has then the late CPU will still boot 1871 but with the feature disabled. On such a system, this option should 1872 not be selected. 1873 1874config ARM64_PTR_AUTH_KERNEL 1875 bool "Use pointer authentication for kernel" 1876 default y 1877 depends on ARM64_PTR_AUTH 1878 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1879 # Modern compilers insert a .note.gnu.property section note for PAC 1880 # which is only understood by binutils starting with version 2.33.1. 1881 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1882 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1883 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1884 help 1885 If the compiler supports the -mbranch-protection or 1886 -msign-return-address flag (e.g. GCC 7 or later), then this option 1887 will cause the kernel itself to be compiled with return address 1888 protection. In this case, and if the target hardware is known to 1889 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1890 disabled with minimal loss of protection. 1891 1892 This feature works with FUNCTION_GRAPH_TRACER option only if 1893 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1894 1895config CC_HAS_BRANCH_PROT_PAC_RET 1896 # GCC 9 or later, clang 8 or later 1897 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1898 1899config CC_HAS_SIGN_RETURN_ADDRESS 1900 # GCC 7, 8 1901 def_bool $(cc-option,-msign-return-address=all) 1902 1903config AS_HAS_ARMV8_3 1904 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1905 1906config AS_HAS_CFI_NEGATE_RA_STATE 1907 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1908 1909endmenu # "ARMv8.3 architectural features" 1910 1911menu "ARMv8.4 architectural features" 1912 1913config ARM64_AMU_EXTN 1914 bool "Enable support for the Activity Monitors Unit CPU extension" 1915 default y 1916 help 1917 The activity monitors extension is an optional extension introduced 1918 by the ARMv8.4 CPU architecture. This enables support for version 1 1919 of the activity monitors architecture, AMUv1. 1920 1921 To enable the use of this extension on CPUs that implement it, say Y. 1922 1923 Note that for architectural reasons, firmware _must_ implement AMU 1924 support when running on CPUs that present the activity monitors 1925 extension. The required support is present in: 1926 * Version 1.5 and later of the ARM Trusted Firmware 1927 1928 For kernels that have this configuration enabled but boot with broken 1929 firmware, you may need to say N here until the firmware is fixed. 1930 Otherwise you may experience firmware panics or lockups when 1931 accessing the counter registers. Even if you are not observing these 1932 symptoms, the values returned by the register reads might not 1933 correctly reflect reality. Most commonly, the value read will be 0, 1934 indicating that the counter is not enabled. 1935 1936config AS_HAS_ARMV8_4 1937 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1938 1939config ARM64_TLB_RANGE 1940 bool "Enable support for tlbi range feature" 1941 default y 1942 depends on AS_HAS_ARMV8_4 1943 help 1944 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1945 range of input addresses. 1946 1947 The feature introduces new assembly instructions, and they were 1948 support when binutils >= 2.30. 1949 1950endmenu # "ARMv8.4 architectural features" 1951 1952menu "ARMv8.5 architectural features" 1953 1954config AS_HAS_ARMV8_5 1955 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1956 1957config ARM64_BTI 1958 bool "Branch Target Identification support" 1959 default y 1960 help 1961 Branch Target Identification (part of the ARMv8.5 Extensions) 1962 provides a mechanism to limit the set of locations to which computed 1963 branch instructions such as BR or BLR can jump. 1964 1965 To make use of BTI on CPUs that support it, say Y. 1966 1967 BTI is intended to provide complementary protection to other control 1968 flow integrity protection mechanisms, such as the Pointer 1969 authentication mechanism provided as part of the ARMv8.3 Extensions. 1970 For this reason, it does not make sense to enable this option without 1971 also enabling support for pointer authentication. Thus, when 1972 enabling this option you should also select ARM64_PTR_AUTH=y. 1973 1974 Userspace binaries must also be specifically compiled to make use of 1975 this mechanism. If you say N here or the hardware does not support 1976 BTI, such binaries can still run, but you get no additional 1977 enforcement of branch destinations. 1978 1979config ARM64_BTI_KERNEL 1980 bool "Use Branch Target Identification for kernel" 1981 default y 1982 depends on ARM64_BTI 1983 depends on ARM64_PTR_AUTH_KERNEL 1984 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1985 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1986 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1987 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1988 depends on !CC_IS_GCC 1989 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1990 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1991 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1992 help 1993 Build the kernel with Branch Target Identification annotations 1994 and enable enforcement of this for kernel code. When this option 1995 is enabled and the system supports BTI all kernel code including 1996 modular code must have BTI enabled. 1997 1998config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1999 # GCC 9 or later, clang 8 or later 2000 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2001 2002config ARM64_E0PD 2003 bool "Enable support for E0PD" 2004 default y 2005 help 2006 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2007 that EL0 accesses made via TTBR1 always fault in constant time, 2008 providing similar benefits to KASLR as those provided by KPTI, but 2009 with lower overhead and without disrupting legitimate access to 2010 kernel memory such as SPE. 2011 2012 This option enables E0PD for TTBR1 where available. 2013 2014config ARM64_AS_HAS_MTE 2015 # Initial support for MTE went in binutils 2.32.0, checked with 2016 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2017 # as a late addition to the final architecture spec (LDGM/STGM) 2018 # is only supported in the newer 2.32.x and 2.33 binutils 2019 # versions, hence the extra "stgm" instruction check below. 2020 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2021 2022config ARM64_MTE 2023 bool "Memory Tagging Extension support" 2024 default y 2025 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2026 depends on AS_HAS_ARMV8_5 2027 depends on AS_HAS_LSE_ATOMICS 2028 # Required for tag checking in the uaccess routines 2029 depends on ARM64_PAN 2030 select ARCH_HAS_SUBPAGE_FAULTS 2031 select ARCH_USES_HIGH_VMA_FLAGS 2032 select ARCH_USES_PG_ARCH_X 2033 help 2034 Memory Tagging (part of the ARMv8.5 Extensions) provides 2035 architectural support for run-time, always-on detection of 2036 various classes of memory error to aid with software debugging 2037 to eliminate vulnerabilities arising from memory-unsafe 2038 languages. 2039 2040 This option enables the support for the Memory Tagging 2041 Extension at EL0 (i.e. for userspace). 2042 2043 Selecting this option allows the feature to be detected at 2044 runtime. Any secondary CPU not implementing this feature will 2045 not be allowed a late bring-up. 2046 2047 Userspace binaries that want to use this feature must 2048 explicitly opt in. The mechanism for the userspace is 2049 described in: 2050 2051 Documentation/arm64/memory-tagging-extension.rst. 2052 2053endmenu # "ARMv8.5 architectural features" 2054 2055menu "ARMv8.7 architectural features" 2056 2057config ARM64_EPAN 2058 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2059 default y 2060 depends on ARM64_PAN 2061 help 2062 Enhanced Privileged Access Never (EPAN) allows Privileged 2063 Access Never to be used with Execute-only mappings. 2064 2065 The feature is detected at runtime, and will remain disabled 2066 if the cpu does not implement the feature. 2067endmenu # "ARMv8.7 architectural features" 2068 2069config ARM64_SVE 2070 bool "ARM Scalable Vector Extension support" 2071 default y 2072 help 2073 The Scalable Vector Extension (SVE) is an extension to the AArch64 2074 execution state which complements and extends the SIMD functionality 2075 of the base architecture to support much larger vectors and to enable 2076 additional vectorisation opportunities. 2077 2078 To enable use of this extension on CPUs that implement it, say Y. 2079 2080 On CPUs that support the SVE2 extensions, this option will enable 2081 those too. 2082 2083 Note that for architectural reasons, firmware _must_ implement SVE 2084 support when running on SVE capable hardware. The required support 2085 is present in: 2086 2087 * version 1.5 and later of the ARM Trusted Firmware 2088 * the AArch64 boot wrapper since commit 5e1261e08abf 2089 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2090 2091 For other firmware implementations, consult the firmware documentation 2092 or vendor. 2093 2094 If you need the kernel to boot on SVE-capable hardware with broken 2095 firmware, you may need to say N here until you get your firmware 2096 fixed. Otherwise, you may experience firmware panics or lockups when 2097 booting the kernel. If unsure and you are not observing these 2098 symptoms, you should assume that it is safe to say Y. 2099 2100config ARM64_SME 2101 bool "ARM Scalable Matrix Extension support" 2102 default y 2103 depends on ARM64_SVE 2104 help 2105 The Scalable Matrix Extension (SME) is an extension to the AArch64 2106 execution state which utilises a substantial subset of the SVE 2107 instruction set, together with the addition of new architectural 2108 register state capable of holding two dimensional matrix tiles to 2109 enable various matrix operations. 2110 2111config ARM64_MODULE_PLTS 2112 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2113 depends on MODULES 2114 select HAVE_MOD_ARCH_SPECIFIC 2115 help 2116 Allocate PLTs when loading modules so that jumps and calls whose 2117 targets are too far away for their relative offsets to be encoded 2118 in the instructions themselves can be bounced via veneers in the 2119 module's PLT. This allows modules to be allocated in the generic 2120 vmalloc area after the dedicated module memory area has been 2121 exhausted. 2122 2123 When running with address space randomization (KASLR), the module 2124 region itself may be too far away for ordinary relative jumps and 2125 calls, and so in that case, module PLTs are required and cannot be 2126 disabled. 2127 2128 Specific errata workaround(s) might also force module PLTs to be 2129 enabled (ARM64_ERRATUM_843419). 2130 2131config ARM64_PSEUDO_NMI 2132 bool "Support for NMI-like interrupts" 2133 select ARM_GIC_V3 2134 help 2135 Adds support for mimicking Non-Maskable Interrupts through the use of 2136 GIC interrupt priority. This support requires version 3 or later of 2137 ARM GIC. 2138 2139 This high priority configuration for interrupts needs to be 2140 explicitly enabled by setting the kernel parameter 2141 "irqchip.gicv3_pseudo_nmi" to 1. 2142 2143 If unsure, say N 2144 2145if ARM64_PSEUDO_NMI 2146config ARM64_DEBUG_PRIORITY_MASKING 2147 bool "Debug interrupt priority masking" 2148 help 2149 This adds runtime checks to functions enabling/disabling 2150 interrupts when using priority masking. The additional checks verify 2151 the validity of ICC_PMR_EL1 when calling concerned functions. 2152 2153 If unsure, say N 2154endif # ARM64_PSEUDO_NMI 2155 2156config RELOCATABLE 2157 bool "Build a relocatable kernel image" if EXPERT 2158 select ARCH_HAS_RELR 2159 default y 2160 help 2161 This builds the kernel as a Position Independent Executable (PIE), 2162 which retains all relocation metadata required to relocate the 2163 kernel binary at runtime to a different virtual address than the 2164 address it was linked at. 2165 Since AArch64 uses the RELA relocation format, this requires a 2166 relocation pass at runtime even if the kernel is loaded at the 2167 same address it was linked at. 2168 2169config RANDOMIZE_BASE 2170 bool "Randomize the address of the kernel image" 2171 select ARM64_MODULE_PLTS if MODULES 2172 select RELOCATABLE 2173 help 2174 Randomizes the virtual address at which the kernel image is 2175 loaded, as a security feature that deters exploit attempts 2176 relying on knowledge of the location of kernel internals. 2177 2178 It is the bootloader's job to provide entropy, by passing a 2179 random u64 value in /chosen/kaslr-seed at kernel entry. 2180 2181 When booting via the UEFI stub, it will invoke the firmware's 2182 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2183 to the kernel proper. In addition, it will randomise the physical 2184 location of the kernel Image as well. 2185 2186 If unsure, say N. 2187 2188config RANDOMIZE_MODULE_REGION_FULL 2189 bool "Randomize the module region over a 2 GB range" 2190 depends on RANDOMIZE_BASE 2191 default y 2192 help 2193 Randomizes the location of the module region inside a 2 GB window 2194 covering the core kernel. This way, it is less likely for modules 2195 to leak information about the location of core kernel data structures 2196 but it does imply that function calls between modules and the core 2197 kernel will need to be resolved via veneers in the module PLT. 2198 2199 When this option is not set, the module region will be randomized over 2200 a limited range that contains the [_stext, _etext] interval of the 2201 core kernel, so branch relocations are almost always in range unless 2202 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2203 particular case of region exhaustion, modules might be able to fall 2204 back to a larger 2GB area. 2205 2206config CC_HAVE_STACKPROTECTOR_SYSREG 2207 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2208 2209config STACKPROTECTOR_PER_TASK 2210 def_bool y 2211 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2212 2213config UNWIND_PATCH_PAC_INTO_SCS 2214 bool "Enable shadow call stack dynamically using code patching" 2215 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2216 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2217 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2218 depends on SHADOW_CALL_STACK 2219 select UNWIND_TABLES 2220 select DYNAMIC_SCS 2221 2222endmenu # "Kernel Features" 2223 2224menu "Boot options" 2225 2226config ARM64_ACPI_PARKING_PROTOCOL 2227 bool "Enable support for the ARM64 ACPI parking protocol" 2228 depends on ACPI 2229 help 2230 Enable support for the ARM64 ACPI parking protocol. If disabled 2231 the kernel will not allow booting through the ARM64 ACPI parking 2232 protocol even if the corresponding data is present in the ACPI 2233 MADT table. 2234 2235config CMDLINE 2236 string "Default kernel command string" 2237 default "" 2238 help 2239 Provide a set of default command-line options at build time by 2240 entering them here. As a minimum, you should specify the the 2241 root device (e.g. root=/dev/nfs). 2242 2243choice 2244 prompt "Kernel command line type" if CMDLINE != "" 2245 default CMDLINE_FROM_BOOTLOADER 2246 help 2247 Choose how the kernel will handle the provided default kernel 2248 command line string. 2249 2250config CMDLINE_FROM_BOOTLOADER 2251 bool "Use bootloader kernel arguments if available" 2252 help 2253 Uses the command-line options passed by the boot loader. If 2254 the boot loader doesn't provide any, the default kernel command 2255 string provided in CMDLINE will be used. 2256 2257config CMDLINE_FORCE 2258 bool "Always use the default kernel command string" 2259 help 2260 Always use the default kernel command string, even if the boot 2261 loader passes other arguments to the kernel. 2262 This is useful if you cannot or don't want to change the 2263 command-line options your boot loader passes to the kernel. 2264 2265endchoice 2266 2267config EFI_STUB 2268 bool 2269 2270config EFI 2271 bool "UEFI runtime support" 2272 depends on OF && !CPU_BIG_ENDIAN 2273 depends on KERNEL_MODE_NEON 2274 select ARCH_SUPPORTS_ACPI 2275 select LIBFDT 2276 select UCS2_STRING 2277 select EFI_PARAMS_FROM_FDT 2278 select EFI_RUNTIME_WRAPPERS 2279 select EFI_STUB 2280 select EFI_GENERIC_STUB 2281 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2282 default y 2283 help 2284 This option provides support for runtime services provided 2285 by UEFI firmware (such as non-volatile variables, realtime 2286 clock, and platform reset). A UEFI stub is also provided to 2287 allow the kernel to be booted as an EFI application. This 2288 is only useful on systems that have UEFI firmware. 2289 2290config DMI 2291 bool "Enable support for SMBIOS (DMI) tables" 2292 depends on EFI 2293 default y 2294 help 2295 This enables SMBIOS/DMI feature for systems. 2296 2297 This option is only useful on systems that have UEFI firmware. 2298 However, even with this option, the resultant kernel should 2299 continue to boot on existing non-UEFI platforms. 2300 2301endmenu # "Boot options" 2302 2303menu "Power management options" 2304 2305source "kernel/power/Kconfig" 2306 2307config ARCH_HIBERNATION_POSSIBLE 2308 def_bool y 2309 depends on CPU_PM 2310 2311config ARCH_HIBERNATION_HEADER 2312 def_bool y 2313 depends on HIBERNATION 2314 2315config ARCH_SUSPEND_POSSIBLE 2316 def_bool y 2317 2318endmenu # "Power management options" 2319 2320menu "CPU Power Management" 2321 2322source "drivers/cpuidle/Kconfig" 2323 2324source "drivers/cpufreq/Kconfig" 2325 2326endmenu # "CPU Power Management" 2327 2328source "drivers/acpi/Kconfig" 2329 2330source "arch/arm64/kvm/Kconfig" 2331 2332