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_DIRECT_REMAP 124 select EDAC_SUPPORT 125 select FRAME_POINTER 126 select FUNCTION_ALIGNMENT_4B 127 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 128 select GENERIC_ALLOCATOR 129 select GENERIC_ARCH_TOPOLOGY 130 select GENERIC_CLOCKEVENTS_BROADCAST 131 select GENERIC_CPU_AUTOPROBE 132 select GENERIC_CPU_VULNERABILITIES 133 select GENERIC_EARLY_IOREMAP 134 select GENERIC_IDLE_POLL_SETUP 135 select GENERIC_IOREMAP 136 select GENERIC_IRQ_IPI 137 select GENERIC_IRQ_PROBE 138 select GENERIC_IRQ_SHOW 139 select GENERIC_IRQ_SHOW_LEVEL 140 select GENERIC_LIB_DEVMEM_IS_ALLOWED 141 select GENERIC_PCI_IOMAP 142 select GENERIC_PTDUMP 143 select GENERIC_SCHED_CLOCK 144 select GENERIC_SMP_IDLE_THREAD 145 select GENERIC_TIME_VSYSCALL 146 select GENERIC_GETTIMEOFDAY 147 select GENERIC_VDSO_TIME_NS 148 select HARDIRQS_SW_RESEND 149 select HAS_IOPORT 150 select HAVE_MOVE_PMD 151 select HAVE_MOVE_PUD 152 select HAVE_PCI 153 select HAVE_ACPI_APEI if (ACPI && EFI) 154 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 155 select HAVE_ARCH_AUDITSYSCALL 156 select HAVE_ARCH_BITREVERSE 157 select HAVE_ARCH_COMPILER_H 158 select HAVE_ARCH_HUGE_VMALLOC 159 select HAVE_ARCH_HUGE_VMAP 160 select HAVE_ARCH_JUMP_LABEL 161 select HAVE_ARCH_JUMP_LABEL_RELATIVE 162 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 163 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 164 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 165 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 166 # Some instrumentation may be unsound, hence EXPERT 167 select HAVE_ARCH_KCSAN if EXPERT 168 select HAVE_ARCH_KFENCE 169 select HAVE_ARCH_KGDB 170 select HAVE_ARCH_MMAP_RND_BITS 171 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 172 select HAVE_ARCH_PREL32_RELOCATIONS 173 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 174 select HAVE_ARCH_SECCOMP_FILTER 175 select HAVE_ARCH_STACKLEAK 176 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 177 select HAVE_ARCH_TRACEHOOK 178 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 179 select HAVE_ARCH_VMAP_STACK 180 select HAVE_ARM_SMCCC 181 select HAVE_ASM_MODVERSIONS 182 select HAVE_EBPF_JIT 183 select HAVE_C_RECORDMCOUNT 184 select HAVE_CMPXCHG_DOUBLE 185 select HAVE_CMPXCHG_LOCAL 186 select HAVE_CONTEXT_TRACKING_USER 187 select HAVE_DEBUG_KMEMLEAK 188 select HAVE_DMA_CONTIGUOUS 189 select HAVE_DYNAMIC_FTRACE 190 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 191 if $(cc-option,-fpatchable-function-entry=2) 192 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 193 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 194 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 195 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 196 !CC_OPTIMIZE_FOR_SIZE) 197 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 198 if DYNAMIC_FTRACE_WITH_ARGS 199 select HAVE_EFFICIENT_UNALIGNED_ACCESS 200 select HAVE_FAST_GUP 201 select HAVE_FTRACE_MCOUNT_RECORD 202 select HAVE_FUNCTION_TRACER 203 select HAVE_FUNCTION_ERROR_INJECTION 204 select HAVE_FUNCTION_GRAPH_TRACER 205 select HAVE_GCC_PLUGINS 206 select HAVE_HW_BREAKPOINT if PERF_EVENTS 207 select HAVE_IOREMAP_PROT 208 select HAVE_IRQ_TIME_ACCOUNTING 209 select HAVE_KVM 210 select HAVE_NMI 211 select HAVE_PERF_EVENTS 212 select HAVE_PERF_REGS 213 select HAVE_PERF_USER_STACK_DUMP 214 select HAVE_PREEMPT_DYNAMIC_KEY 215 select HAVE_REGS_AND_STACK_ACCESS_API 216 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 217 select HAVE_FUNCTION_ARG_ACCESS_API 218 select MMU_GATHER_RCU_TABLE_FREE 219 select HAVE_RSEQ 220 select HAVE_STACKPROTECTOR 221 select HAVE_SYSCALL_TRACEPOINTS 222 select HAVE_KPROBES 223 select HAVE_KRETPROBES 224 select HAVE_GENERIC_VDSO 225 select IRQ_DOMAIN 226 select IRQ_FORCED_THREADING 227 select KASAN_VMALLOC if KASAN 228 select MODULES_USE_ELF_RELA 229 select NEED_DMA_MAP_STATE 230 select NEED_SG_DMA_LENGTH 231 select OF 232 select OF_EARLY_FLATTREE 233 select PCI_DOMAINS_GENERIC if PCI 234 select PCI_ECAM if (ACPI && PCI) 235 select PCI_SYSCALL if PCI 236 select POWER_RESET 237 select POWER_SUPPLY 238 select SPARSE_IRQ 239 select SWIOTLB 240 select SYSCTL_EXCEPTION_TRACE 241 select THREAD_INFO_IN_TASK 242 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 243 select TRACE_IRQFLAGS_SUPPORT 244 select TRACE_IRQFLAGS_NMI_SUPPORT 245 select HAVE_SOFTIRQ_ON_OWN_STACK 246 help 247 ARM 64-bit (AArch64) Linux support. 248 249config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 250 def_bool CC_IS_CLANG 251 # https://github.com/ClangBuiltLinux/linux/issues/1507 252 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 253 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 254 255config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 256 def_bool CC_IS_GCC 257 depends on $(cc-option,-fpatchable-function-entry=2) 258 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 259 260config 64BIT 261 def_bool y 262 263config MMU 264 def_bool y 265 266config ARM64_PAGE_SHIFT 267 int 268 default 16 if ARM64_64K_PAGES 269 default 14 if ARM64_16K_PAGES 270 default 12 271 272config ARM64_CONT_PTE_SHIFT 273 int 274 default 5 if ARM64_64K_PAGES 275 default 7 if ARM64_16K_PAGES 276 default 4 277 278config ARM64_CONT_PMD_SHIFT 279 int 280 default 5 if ARM64_64K_PAGES 281 default 5 if ARM64_16K_PAGES 282 default 4 283 284config ARCH_MMAP_RND_BITS_MIN 285 default 14 if ARM64_64K_PAGES 286 default 16 if ARM64_16K_PAGES 287 default 18 288 289# max bits determined by the following formula: 290# VA_BITS - PAGE_SHIFT - 3 291config ARCH_MMAP_RND_BITS_MAX 292 default 19 if ARM64_VA_BITS=36 293 default 24 if ARM64_VA_BITS=39 294 default 27 if ARM64_VA_BITS=42 295 default 30 if ARM64_VA_BITS=47 296 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 297 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 298 default 33 if ARM64_VA_BITS=48 299 default 14 if ARM64_64K_PAGES 300 default 16 if ARM64_16K_PAGES 301 default 18 302 303config ARCH_MMAP_RND_COMPAT_BITS_MIN 304 default 7 if ARM64_64K_PAGES 305 default 9 if ARM64_16K_PAGES 306 default 11 307 308config ARCH_MMAP_RND_COMPAT_BITS_MAX 309 default 16 310 311config NO_IOPORT_MAP 312 def_bool y if !PCI 313 314config STACKTRACE_SUPPORT 315 def_bool y 316 317config ILLEGAL_POINTER_VALUE 318 hex 319 default 0xdead000000000000 320 321config LOCKDEP_SUPPORT 322 def_bool y 323 324config GENERIC_BUG 325 def_bool y 326 depends on BUG 327 328config GENERIC_BUG_RELATIVE_POINTERS 329 def_bool y 330 depends on GENERIC_BUG 331 332config GENERIC_HWEIGHT 333 def_bool y 334 335config GENERIC_CSUM 336 def_bool y 337 338config GENERIC_CALIBRATE_DELAY 339 def_bool y 340 341config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 342 def_bool y 343 344config SMP 345 def_bool y 346 347config KERNEL_MODE_NEON 348 def_bool y 349 350config FIX_EARLYCON_MEM 351 def_bool y 352 353config PGTABLE_LEVELS 354 int 355 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 356 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 357 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 358 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 359 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 360 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 361 362config ARCH_SUPPORTS_UPROBES 363 def_bool y 364 365config ARCH_PROC_KCORE_TEXT 366 def_bool y 367 368config BROKEN_GAS_INST 369 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 370 371config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 372 bool 373 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 374 # https://reviews.llvm.org/D75044 375 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 376 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 377 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 378 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 379 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 380 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 381 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 382 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 383 default n 384 385config KASAN_SHADOW_OFFSET 386 hex 387 depends on KASAN_GENERIC || KASAN_SW_TAGS 388 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 389 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 390 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 391 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 392 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 393 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 394 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 395 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 396 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 397 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 398 default 0xffffffffffffffff 399 400config UNWIND_TABLES 401 bool 402 403source "arch/arm64/Kconfig.platforms" 404 405menu "Kernel Features" 406 407menu "ARM errata workarounds via the alternatives framework" 408 409config ARM64_WORKAROUND_CLEAN_CACHE 410 bool 411 412config ARM64_ERRATUM_826319 413 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 414 default y 415 select ARM64_WORKAROUND_CLEAN_CACHE 416 help 417 This option adds an alternative code sequence to work around ARM 418 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 419 AXI master interface and an L2 cache. 420 421 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 422 and is unable to accept a certain write via this interface, it will 423 not progress on read data presented on the read data channel and the 424 system can deadlock. 425 426 The workaround promotes data cache clean instructions to 427 data cache clean-and-invalidate. 428 Please note that this does not necessarily enable the workaround, 429 as it depends on the alternative framework, which will only patch 430 the kernel if an affected CPU is detected. 431 432 If unsure, say Y. 433 434config ARM64_ERRATUM_827319 435 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 436 default y 437 select ARM64_WORKAROUND_CLEAN_CACHE 438 help 439 This option adds an alternative code sequence to work around ARM 440 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 441 master interface and an L2 cache. 442 443 Under certain conditions this erratum can cause a clean line eviction 444 to occur at the same time as another transaction to the same address 445 on the AMBA 5 CHI interface, which can cause data corruption if the 446 interconnect reorders the two transactions. 447 448 The workaround promotes data cache clean instructions to 449 data cache clean-and-invalidate. 450 Please note that this does not necessarily enable the workaround, 451 as it depends on the alternative framework, which will only patch 452 the kernel if an affected CPU is detected. 453 454 If unsure, say Y. 455 456config ARM64_ERRATUM_824069 457 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 458 default y 459 select ARM64_WORKAROUND_CLEAN_CACHE 460 help 461 This option adds an alternative code sequence to work around ARM 462 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 463 to a coherent interconnect. 464 465 If a Cortex-A53 processor is executing a store or prefetch for 466 write instruction at the same time as a processor in another 467 cluster is executing a cache maintenance operation to the same 468 address, then this erratum might cause a clean cache line to be 469 incorrectly marked as dirty. 470 471 The workaround promotes data cache clean instructions to 472 data cache clean-and-invalidate. 473 Please note that this option does not necessarily enable the 474 workaround, as it depends on the alternative framework, which will 475 only patch the kernel if an affected CPU is detected. 476 477 If unsure, say Y. 478 479config ARM64_ERRATUM_819472 480 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 481 default y 482 select ARM64_WORKAROUND_CLEAN_CACHE 483 help 484 This option adds an alternative code sequence to work around ARM 485 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 486 present when it is connected to a coherent interconnect. 487 488 If the processor is executing a load and store exclusive sequence at 489 the same time as a processor in another cluster is executing a cache 490 maintenance operation to the same address, then this erratum might 491 cause data corruption. 492 493 The workaround promotes data cache clean instructions to 494 data cache clean-and-invalidate. 495 Please note that this does not necessarily enable the workaround, 496 as it depends on the alternative framework, which will only patch 497 the kernel if an affected CPU is detected. 498 499 If unsure, say Y. 500 501config ARM64_ERRATUM_832075 502 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 503 default y 504 help 505 This option adds an alternative code sequence to work around ARM 506 erratum 832075 on Cortex-A57 parts up to r1p2. 507 508 Affected Cortex-A57 parts might deadlock when exclusive load/store 509 instructions to Write-Back memory are mixed with Device loads. 510 511 The workaround is to promote device loads to use Load-Acquire 512 semantics. 513 Please note that this does not necessarily enable the workaround, 514 as it depends on the alternative framework, which will only patch 515 the kernel if an affected CPU is detected. 516 517 If unsure, say Y. 518 519config ARM64_ERRATUM_834220 520 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 521 depends on KVM 522 default y 523 help 524 This option adds an alternative code sequence to work around ARM 525 erratum 834220 on Cortex-A57 parts up to r1p2. 526 527 Affected Cortex-A57 parts might report a Stage 2 translation 528 fault as the result of a Stage 1 fault for load crossing a 529 page boundary when there is a permission or device memory 530 alignment fault at Stage 1 and a translation fault at Stage 2. 531 532 The workaround is to verify that the Stage 1 translation 533 doesn't generate a fault before handling the Stage 2 fault. 534 Please note that this does not necessarily enable the workaround, 535 as it depends on the alternative framework, which will only patch 536 the kernel if an affected CPU is detected. 537 538 If unsure, say Y. 539 540config ARM64_ERRATUM_1742098 541 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 542 depends on COMPAT 543 default y 544 help 545 This option removes the AES hwcap for aarch32 user-space to 546 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 547 548 Affected parts may corrupt the AES state if an interrupt is 549 taken between a pair of AES instructions. These instructions 550 are only present if the cryptography extensions are present. 551 All software should have a fallback implementation for CPUs 552 that don't implement the cryptography extensions. 553 554 If unsure, say Y. 555 556config ARM64_ERRATUM_845719 557 bool "Cortex-A53: 845719: a load might read incorrect data" 558 depends on COMPAT 559 default y 560 help 561 This option adds an alternative code sequence to work around ARM 562 erratum 845719 on Cortex-A53 parts up to r0p4. 563 564 When running a compat (AArch32) userspace on an affected Cortex-A53 565 part, a load at EL0 from a virtual address that matches the bottom 32 566 bits of the virtual address used by a recent load at (AArch64) EL1 567 might return incorrect data. 568 569 The workaround is to write the contextidr_el1 register on exception 570 return to a 32-bit task. 571 Please note that this does not necessarily enable the workaround, 572 as it depends on the alternative framework, which will only patch 573 the kernel if an affected CPU is detected. 574 575 If unsure, say Y. 576 577config ARM64_ERRATUM_843419 578 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 579 default y 580 select ARM64_MODULE_PLTS if MODULES 581 help 582 This option links the kernel with '--fix-cortex-a53-843419' and 583 enables PLT support to replace certain ADRP instructions, which can 584 cause subsequent memory accesses to use an incorrect address on 585 Cortex-A53 parts up to r0p4. 586 587 If unsure, say Y. 588 589config ARM64_LD_HAS_FIX_ERRATUM_843419 590 def_bool $(ld-option,--fix-cortex-a53-843419) 591 592config ARM64_ERRATUM_1024718 593 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 594 default y 595 help 596 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 597 598 Affected Cortex-A55 cores (all revisions) could cause incorrect 599 update of the hardware dirty bit when the DBM/AP bits are updated 600 without a break-before-make. The workaround is to disable the usage 601 of hardware DBM locally on the affected cores. CPUs not affected by 602 this erratum will continue to use the feature. 603 604 If unsure, say Y. 605 606config ARM64_ERRATUM_1418040 607 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 608 default y 609 depends on COMPAT 610 help 611 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 612 errata 1188873 and 1418040. 613 614 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 615 cause register corruption when accessing the timer registers 616 from AArch32 userspace. 617 618 If unsure, say Y. 619 620config ARM64_WORKAROUND_SPECULATIVE_AT 621 bool 622 623config ARM64_ERRATUM_1165522 624 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 625 default y 626 select ARM64_WORKAROUND_SPECULATIVE_AT 627 help 628 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 629 630 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 631 corrupted TLBs by speculating an AT instruction during a guest 632 context switch. 633 634 If unsure, say Y. 635 636config ARM64_ERRATUM_1319367 637 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 638 default y 639 select ARM64_WORKAROUND_SPECULATIVE_AT 640 help 641 This option adds work arounds for ARM Cortex-A57 erratum 1319537 642 and A72 erratum 1319367 643 644 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 645 speculating an AT instruction during a guest context switch. 646 647 If unsure, say Y. 648 649config ARM64_ERRATUM_1530923 650 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 651 default y 652 select ARM64_WORKAROUND_SPECULATIVE_AT 653 help 654 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 655 656 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 657 corrupted TLBs by speculating an AT instruction during a guest 658 context switch. 659 660 If unsure, say Y. 661 662config ARM64_WORKAROUND_REPEAT_TLBI 663 bool 664 665config ARM64_ERRATUM_2441007 666 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 667 default y 668 select ARM64_WORKAROUND_REPEAT_TLBI 669 help 670 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 671 672 Under very rare circumstances, affected Cortex-A55 CPUs 673 may not handle a race between a break-before-make sequence on one 674 CPU, and another CPU accessing the same page. This could allow a 675 store to a page that has been unmapped. 676 677 Work around this by adding the affected CPUs to the list that needs 678 TLB sequences to be done twice. 679 680 If unsure, say Y. 681 682config ARM64_ERRATUM_1286807 683 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 684 default y 685 select ARM64_WORKAROUND_REPEAT_TLBI 686 help 687 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 688 689 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 690 address for a cacheable mapping of a location is being 691 accessed by a core while another core is remapping the virtual 692 address to a new physical page using the recommended 693 break-before-make sequence, then under very rare circumstances 694 TLBI+DSB completes before a read using the translation being 695 invalidated has been observed by other observers. The 696 workaround repeats the TLBI+DSB operation. 697 698config ARM64_ERRATUM_1463225 699 bool "Cortex-A76: Software Step might prevent interrupt recognition" 700 default y 701 help 702 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 703 704 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 705 of a system call instruction (SVC) can prevent recognition of 706 subsequent interrupts when software stepping is disabled in the 707 exception handler of the system call and either kernel debugging 708 is enabled or VHE is in use. 709 710 Work around the erratum by triggering a dummy step exception 711 when handling a system call from a task that is being stepped 712 in a VHE configuration of the kernel. 713 714 If unsure, say Y. 715 716config ARM64_ERRATUM_1542419 717 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 718 default y 719 help 720 This option adds a workaround for ARM Neoverse-N1 erratum 721 1542419. 722 723 Affected Neoverse-N1 cores could execute a stale instruction when 724 modified by another CPU. The workaround depends on a firmware 725 counterpart. 726 727 Workaround the issue by hiding the DIC feature from EL0. This 728 forces user-space to perform cache maintenance. 729 730 If unsure, say Y. 731 732config ARM64_ERRATUM_1508412 733 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 734 default y 735 help 736 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 737 738 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 739 of a store-exclusive or read of PAR_EL1 and a load with device or 740 non-cacheable memory attributes. The workaround depends on a firmware 741 counterpart. 742 743 KVM guests must also have the workaround implemented or they can 744 deadlock the system. 745 746 Work around the issue by inserting DMB SY barriers around PAR_EL1 747 register reads and warning KVM users. The DMB barrier is sufficient 748 to prevent a speculative PAR_EL1 read. 749 750 If unsure, say Y. 751 752config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 753 bool 754 755config ARM64_ERRATUM_2051678 756 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 757 default y 758 help 759 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 760 Affected Cortex-A510 might not respect the ordering rules for 761 hardware update of the page table's dirty bit. The workaround 762 is to not enable the feature on affected CPUs. 763 764 If unsure, say Y. 765 766config ARM64_ERRATUM_2077057 767 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 768 default y 769 help 770 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 771 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 772 expected, but a Pointer Authentication trap is taken instead. The 773 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 774 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 775 776 This can only happen when EL2 is stepping EL1. 777 778 When these conditions occur, the SPSR_EL2 value is unchanged from the 779 previous guest entry, and can be restored from the in-memory copy. 780 781 If unsure, say Y. 782 783config ARM64_ERRATUM_2658417 784 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 785 default y 786 help 787 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 788 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 789 BFMMLA or VMMLA instructions in rare circumstances when a pair of 790 A510 CPUs are using shared neon hardware. As the sharing is not 791 discoverable by the kernel, hide the BF16 HWCAP to indicate that 792 user-space should not be using these instructions. 793 794 If unsure, say Y. 795 796config ARM64_ERRATUM_2119858 797 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 798 default y 799 depends on CORESIGHT_TRBE 800 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 801 help 802 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 803 804 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 805 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 806 the event of a WRAP event. 807 808 Work around the issue by always making sure we move the TRBPTR_EL1 by 809 256 bytes before enabling the buffer and filling the first 256 bytes of 810 the buffer with ETM ignore packets upon disabling. 811 812 If unsure, say Y. 813 814config ARM64_ERRATUM_2139208 815 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 816 default y 817 depends on CORESIGHT_TRBE 818 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 819 help 820 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 821 822 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 823 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 824 the event of a WRAP event. 825 826 Work around the issue by always making sure we move the TRBPTR_EL1 by 827 256 bytes before enabling the buffer and filling the first 256 bytes of 828 the buffer with ETM ignore packets upon disabling. 829 830 If unsure, say Y. 831 832config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 833 bool 834 835config ARM64_ERRATUM_2054223 836 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 837 default y 838 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 839 help 840 Enable workaround for ARM Cortex-A710 erratum 2054223 841 842 Affected cores may fail to flush the trace data on a TSB instruction, when 843 the PE is in trace prohibited state. This will cause losing a few bytes 844 of the trace cached. 845 846 Workaround is to issue two TSB consecutively on affected cores. 847 848 If unsure, say Y. 849 850config ARM64_ERRATUM_2067961 851 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 852 default y 853 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 854 help 855 Enable workaround for ARM Neoverse-N2 erratum 2067961 856 857 Affected cores may fail to flush the trace data on a TSB instruction, when 858 the PE is in trace prohibited state. This will cause losing a few bytes 859 of the trace cached. 860 861 Workaround is to issue two TSB consecutively on affected cores. 862 863 If unsure, say Y. 864 865config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 866 bool 867 868config ARM64_ERRATUM_2253138 869 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 870 depends on CORESIGHT_TRBE 871 default y 872 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 873 help 874 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 875 876 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 877 for TRBE. Under some conditions, the TRBE might generate a write to the next 878 virtually addressed page following the last page of the TRBE address space 879 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 880 881 Work around this in the driver by always making sure that there is a 882 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 883 884 If unsure, say Y. 885 886config ARM64_ERRATUM_2224489 887 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 888 depends on CORESIGHT_TRBE 889 default y 890 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 891 help 892 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 893 894 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 895 for TRBE. Under some conditions, the TRBE might generate a write to the next 896 virtually addressed page following the last page of the TRBE address space 897 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 898 899 Work around this in the driver by always making sure that there is a 900 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 901 902 If unsure, say Y. 903 904config ARM64_ERRATUM_2441009 905 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 906 default y 907 select ARM64_WORKAROUND_REPEAT_TLBI 908 help 909 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 910 911 Under very rare circumstances, affected Cortex-A510 CPUs 912 may not handle a race between a break-before-make sequence on one 913 CPU, and another CPU accessing the same page. This could allow a 914 store to a page that has been unmapped. 915 916 Work around this by adding the affected CPUs to the list that needs 917 TLB sequences to be done twice. 918 919 If unsure, say Y. 920 921config ARM64_ERRATUM_2064142 922 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 923 depends on CORESIGHT_TRBE 924 default y 925 help 926 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 927 928 Affected Cortex-A510 core might fail to write into system registers after the 929 TRBE has been disabled. Under some conditions after the TRBE has been disabled 930 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 931 and TRBTRG_EL1 will be ignored and will not be effected. 932 933 Work around this in the driver by executing TSB CSYNC and DSB after collection 934 is stopped and before performing a system register write to one of the affected 935 registers. 936 937 If unsure, say Y. 938 939config ARM64_ERRATUM_2038923 940 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 941 depends on CORESIGHT_TRBE 942 default y 943 help 944 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 945 946 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 947 prohibited within the CPU. As a result, the trace buffer or trace buffer state 948 might be corrupted. This happens after TRBE buffer has been enabled by setting 949 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 950 execution changes from a context, in which trace is prohibited to one where it 951 isn't, or vice versa. In these mentioned conditions, the view of whether trace 952 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 953 the trace buffer state might be corrupted. 954 955 Work around this in the driver by preventing an inconsistent view of whether the 956 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 957 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 958 two ISB instructions if no ERET is to take place. 959 960 If unsure, say Y. 961 962config ARM64_ERRATUM_1902691 963 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 964 depends on CORESIGHT_TRBE 965 default y 966 help 967 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 968 969 Affected Cortex-A510 core might cause trace data corruption, when being written 970 into the memory. Effectively TRBE is broken and hence cannot be used to capture 971 trace data. 972 973 Work around this problem in the driver by just preventing TRBE initialization on 974 affected cpus. The firmware must have disabled the access to TRBE for the kernel 975 on such implementations. This will cover the kernel for any firmware that doesn't 976 do this already. 977 978 If unsure, say Y. 979 980config ARM64_ERRATUM_2457168 981 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 982 depends on ARM64_AMU_EXTN 983 default y 984 help 985 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 986 987 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 988 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 989 incorrectly giving a significantly higher output value. 990 991 Work around this problem by returning 0 when reading the affected counter in 992 key locations that results in disabling all users of this counter. This effect 993 is the same to firmware disabling affected counters. 994 995 If unsure, say Y. 996 997config ARM64_ERRATUM_2645198 998 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 999 default y 1000 help 1001 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1002 1003 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1004 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1005 next instruction abort caused by permission fault. 1006 1007 Only user-space does executable to non-executable permission transition via 1008 mprotect() system call. Workaround the problem by doing a break-before-make 1009 TLB invalidation, for all changes to executable user space mappings. 1010 1011 If unsure, say Y. 1012 1013config CAVIUM_ERRATUM_22375 1014 bool "Cavium erratum 22375, 24313" 1015 default y 1016 help 1017 Enable workaround for errata 22375 and 24313. 1018 1019 This implements two gicv3-its errata workarounds for ThunderX. Both 1020 with a small impact affecting only ITS table allocation. 1021 1022 erratum 22375: only alloc 8MB table size 1023 erratum 24313: ignore memory access type 1024 1025 The fixes are in ITS initialization and basically ignore memory access 1026 type and table size provided by the TYPER and BASER registers. 1027 1028 If unsure, say Y. 1029 1030config CAVIUM_ERRATUM_23144 1031 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1032 depends on NUMA 1033 default y 1034 help 1035 ITS SYNC command hang for cross node io and collections/cpu mapping. 1036 1037 If unsure, say Y. 1038 1039config CAVIUM_ERRATUM_23154 1040 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1041 default y 1042 help 1043 The ThunderX GICv3 implementation requires a modified version for 1044 reading the IAR status to ensure data synchronization 1045 (access to icc_iar1_el1 is not sync'ed before and after). 1046 1047 It also suffers from erratum 38545 (also present on Marvell's 1048 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1049 spuriously presented to the CPU interface. 1050 1051 If unsure, say Y. 1052 1053config CAVIUM_ERRATUM_27456 1054 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1055 default y 1056 help 1057 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1058 instructions may cause the icache to become corrupted if it 1059 contains data for a non-current ASID. The fix is to 1060 invalidate the icache when changing the mm context. 1061 1062 If unsure, say Y. 1063 1064config CAVIUM_ERRATUM_30115 1065 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1066 default y 1067 help 1068 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1069 1.2, and T83 Pass 1.0, KVM guest execution may disable 1070 interrupts in host. Trapping both GICv3 group-0 and group-1 1071 accesses sidesteps the issue. 1072 1073 If unsure, say Y. 1074 1075config CAVIUM_TX2_ERRATUM_219 1076 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1077 default y 1078 help 1079 On Cavium ThunderX2, a load, store or prefetch instruction between a 1080 TTBR update and the corresponding context synchronizing operation can 1081 cause a spurious Data Abort to be delivered to any hardware thread in 1082 the CPU core. 1083 1084 Work around the issue by avoiding the problematic code sequence and 1085 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1086 trap handler performs the corresponding register access, skips the 1087 instruction and ensures context synchronization by virtue of the 1088 exception return. 1089 1090 If unsure, say Y. 1091 1092config FUJITSU_ERRATUM_010001 1093 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1094 default y 1095 help 1096 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1097 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1098 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1099 This fault occurs under a specific hardware condition when a 1100 load/store instruction performs an address translation using: 1101 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1102 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1103 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1104 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1105 1106 The workaround is to ensure these bits are clear in TCR_ELx. 1107 The workaround only affects the Fujitsu-A64FX. 1108 1109 If unsure, say Y. 1110 1111config HISILICON_ERRATUM_161600802 1112 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1113 default y 1114 help 1115 The HiSilicon Hip07 SoC uses the wrong redistributor base 1116 when issued ITS commands such as VMOVP and VMAPP, and requires 1117 a 128kB offset to be applied to the target address in this commands. 1118 1119 If unsure, say Y. 1120 1121config QCOM_FALKOR_ERRATUM_1003 1122 bool "Falkor E1003: Incorrect translation due to ASID change" 1123 default y 1124 help 1125 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1126 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1127 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1128 then only for entries in the walk cache, since the leaf translation 1129 is unchanged. Work around the erratum by invalidating the walk cache 1130 entries for the trampoline before entering the kernel proper. 1131 1132config QCOM_FALKOR_ERRATUM_1009 1133 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1134 default y 1135 select ARM64_WORKAROUND_REPEAT_TLBI 1136 help 1137 On Falkor v1, the CPU may prematurely complete a DSB following a 1138 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1139 one more time to fix the issue. 1140 1141 If unsure, say Y. 1142 1143config QCOM_QDF2400_ERRATUM_0065 1144 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1145 default y 1146 help 1147 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1148 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1149 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1150 1151 If unsure, say Y. 1152 1153config QCOM_FALKOR_ERRATUM_E1041 1154 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1155 default y 1156 help 1157 Falkor CPU may speculatively fetch instructions from an improper 1158 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1159 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1160 1161 If unsure, say Y. 1162 1163config NVIDIA_CARMEL_CNP_ERRATUM 1164 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1165 default y 1166 help 1167 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1168 invalidate shared TLB entries installed by a different core, as it would 1169 on standard ARM cores. 1170 1171 If unsure, say Y. 1172 1173config ROCKCHIP_ERRATUM_3588001 1174 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1175 default y 1176 help 1177 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1178 This means, that its sharability feature may not be used, even though it 1179 is supported by the IP itself. 1180 1181 If unsure, say Y. 1182 1183config SOCIONEXT_SYNQUACER_PREITS 1184 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1185 default y 1186 help 1187 Socionext Synquacer SoCs implement a separate h/w block to generate 1188 MSI doorbell writes with non-zero values for the device ID. 1189 1190 If unsure, say Y. 1191 1192endmenu # "ARM errata workarounds via the alternatives framework" 1193 1194choice 1195 prompt "Page size" 1196 default ARM64_4K_PAGES 1197 help 1198 Page size (translation granule) configuration. 1199 1200config ARM64_4K_PAGES 1201 bool "4KB" 1202 help 1203 This feature enables 4KB pages support. 1204 1205config ARM64_16K_PAGES 1206 bool "16KB" 1207 help 1208 The system will use 16KB pages support. AArch32 emulation 1209 requires applications compiled with 16K (or a multiple of 16K) 1210 aligned segments. 1211 1212config ARM64_64K_PAGES 1213 bool "64KB" 1214 help 1215 This feature enables 64KB pages support (4KB by default) 1216 allowing only two levels of page tables and faster TLB 1217 look-up. AArch32 emulation requires applications compiled 1218 with 64K aligned segments. 1219 1220endchoice 1221 1222choice 1223 prompt "Virtual address space size" 1224 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1225 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1226 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1227 help 1228 Allows choosing one of multiple possible virtual address 1229 space sizes. The level of translation table is determined by 1230 a combination of page size and virtual address space size. 1231 1232config ARM64_VA_BITS_36 1233 bool "36-bit" if EXPERT 1234 depends on ARM64_16K_PAGES 1235 1236config ARM64_VA_BITS_39 1237 bool "39-bit" 1238 depends on ARM64_4K_PAGES 1239 1240config ARM64_VA_BITS_42 1241 bool "42-bit" 1242 depends on ARM64_64K_PAGES 1243 1244config ARM64_VA_BITS_47 1245 bool "47-bit" 1246 depends on ARM64_16K_PAGES 1247 1248config ARM64_VA_BITS_48 1249 bool "48-bit" 1250 1251config ARM64_VA_BITS_52 1252 bool "52-bit" 1253 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1254 help 1255 Enable 52-bit virtual addressing for userspace when explicitly 1256 requested via a hint to mmap(). The kernel will also use 52-bit 1257 virtual addresses for its own mappings (provided HW support for 1258 this feature is available, otherwise it reverts to 48-bit). 1259 1260 NOTE: Enabling 52-bit virtual addressing in conjunction with 1261 ARMv8.3 Pointer Authentication will result in the PAC being 1262 reduced from 7 bits to 3 bits, which may have a significant 1263 impact on its susceptibility to brute-force attacks. 1264 1265 If unsure, select 48-bit virtual addressing instead. 1266 1267endchoice 1268 1269config ARM64_FORCE_52BIT 1270 bool "Force 52-bit virtual addresses for userspace" 1271 depends on ARM64_VA_BITS_52 && EXPERT 1272 help 1273 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1274 to maintain compatibility with older software by providing 48-bit VAs 1275 unless a hint is supplied to mmap. 1276 1277 This configuration option disables the 48-bit compatibility logic, and 1278 forces all userspace addresses to be 52-bit on HW that supports it. One 1279 should only enable this configuration option for stress testing userspace 1280 memory management code. If unsure say N here. 1281 1282config ARM64_VA_BITS 1283 int 1284 default 36 if ARM64_VA_BITS_36 1285 default 39 if ARM64_VA_BITS_39 1286 default 42 if ARM64_VA_BITS_42 1287 default 47 if ARM64_VA_BITS_47 1288 default 48 if ARM64_VA_BITS_48 1289 default 52 if ARM64_VA_BITS_52 1290 1291choice 1292 prompt "Physical address space size" 1293 default ARM64_PA_BITS_48 1294 help 1295 Choose the maximum physical address range that the kernel will 1296 support. 1297 1298config ARM64_PA_BITS_48 1299 bool "48-bit" 1300 1301config ARM64_PA_BITS_52 1302 bool "52-bit (ARMv8.2)" 1303 depends on ARM64_64K_PAGES 1304 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1305 help 1306 Enable support for a 52-bit physical address space, introduced as 1307 part of the ARMv8.2-LPA extension. 1308 1309 With this enabled, the kernel will also continue to work on CPUs that 1310 do not support ARMv8.2-LPA, but with some added memory overhead (and 1311 minor performance overhead). 1312 1313endchoice 1314 1315config ARM64_PA_BITS 1316 int 1317 default 48 if ARM64_PA_BITS_48 1318 default 52 if ARM64_PA_BITS_52 1319 1320choice 1321 prompt "Endianness" 1322 default CPU_LITTLE_ENDIAN 1323 help 1324 Select the endianness of data accesses performed by the CPU. Userspace 1325 applications will need to be compiled and linked for the endianness 1326 that is selected here. 1327 1328config CPU_BIG_ENDIAN 1329 bool "Build big-endian kernel" 1330 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1331 help 1332 Say Y if you plan on running a kernel with a big-endian userspace. 1333 1334config CPU_LITTLE_ENDIAN 1335 bool "Build little-endian kernel" 1336 help 1337 Say Y if you plan on running a kernel with a little-endian userspace. 1338 This is usually the case for distributions targeting arm64. 1339 1340endchoice 1341 1342config SCHED_MC 1343 bool "Multi-core scheduler support" 1344 help 1345 Multi-core scheduler support improves the CPU scheduler's decision 1346 making when dealing with multi-core CPU chips at a cost of slightly 1347 increased overhead in some places. If unsure say N here. 1348 1349config SCHED_CLUSTER 1350 bool "Cluster scheduler support" 1351 help 1352 Cluster scheduler support improves the CPU scheduler's decision 1353 making when dealing with machines that have clusters of CPUs. 1354 Cluster usually means a couple of CPUs which are placed closely 1355 by sharing mid-level caches, last-level cache tags or internal 1356 busses. 1357 1358config SCHED_SMT 1359 bool "SMT scheduler support" 1360 help 1361 Improves the CPU scheduler's decision making when dealing with 1362 MultiThreading at a cost of slightly increased overhead in some 1363 places. If unsure say N here. 1364 1365config NR_CPUS 1366 int "Maximum number of CPUs (2-4096)" 1367 range 2 4096 1368 default "256" 1369 1370config HOTPLUG_CPU 1371 bool "Support for hot-pluggable CPUs" 1372 select GENERIC_IRQ_MIGRATION 1373 help 1374 Say Y here to experiment with turning CPUs off and on. CPUs 1375 can be controlled through /sys/devices/system/cpu. 1376 1377# Common NUMA Features 1378config NUMA 1379 bool "NUMA Memory Allocation and Scheduler Support" 1380 select GENERIC_ARCH_NUMA 1381 select ACPI_NUMA if ACPI 1382 select OF_NUMA 1383 select HAVE_SETUP_PER_CPU_AREA 1384 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1385 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1386 select USE_PERCPU_NUMA_NODE_ID 1387 help 1388 Enable NUMA (Non-Uniform Memory Access) support. 1389 1390 The kernel will try to allocate memory used by a CPU on the 1391 local memory of the CPU and add some more 1392 NUMA awareness to the kernel. 1393 1394config NODES_SHIFT 1395 int "Maximum NUMA Nodes (as a power of 2)" 1396 range 1 10 1397 default "4" 1398 depends on NUMA 1399 help 1400 Specify the maximum number of NUMA Nodes available on the target 1401 system. Increases memory reserved to accommodate various tables. 1402 1403source "kernel/Kconfig.hz" 1404 1405config ARCH_SPARSEMEM_ENABLE 1406 def_bool y 1407 select SPARSEMEM_VMEMMAP_ENABLE 1408 select SPARSEMEM_VMEMMAP 1409 1410config HW_PERF_EVENTS 1411 def_bool y 1412 depends on ARM_PMU 1413 1414# Supported by clang >= 7.0 or GCC >= 12.0.0 1415config CC_HAVE_SHADOW_CALL_STACK 1416 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1417 1418config PARAVIRT 1419 bool "Enable paravirtualization code" 1420 help 1421 This changes the kernel so it can modify itself when it is run 1422 under a hypervisor, potentially improving performance significantly 1423 over full virtualization. 1424 1425config PARAVIRT_TIME_ACCOUNTING 1426 bool "Paravirtual steal time accounting" 1427 select PARAVIRT 1428 help 1429 Select this option to enable fine granularity task steal time 1430 accounting. Time spent executing other tasks in parallel with 1431 the current vCPU is discounted from the vCPU power. To account for 1432 that, there can be a small performance impact. 1433 1434 If in doubt, say N here. 1435 1436config KEXEC 1437 depends on PM_SLEEP_SMP 1438 select KEXEC_CORE 1439 bool "kexec system call" 1440 help 1441 kexec is a system call that implements the ability to shutdown your 1442 current kernel, and to start another kernel. It is like a reboot 1443 but it is independent of the system firmware. And like a reboot 1444 you can start any kernel with it, not just Linux. 1445 1446config KEXEC_FILE 1447 bool "kexec file based system call" 1448 select KEXEC_CORE 1449 select HAVE_IMA_KEXEC if IMA 1450 help 1451 This is new version of kexec system call. This system call is 1452 file based and takes file descriptors as system call argument 1453 for kernel and initramfs as opposed to list of segments as 1454 accepted by previous system call. 1455 1456config KEXEC_SIG 1457 bool "Verify kernel signature during kexec_file_load() syscall" 1458 depends on KEXEC_FILE 1459 help 1460 Select this option to verify a signature with loaded kernel 1461 image. If configured, any attempt of loading a image without 1462 valid signature will fail. 1463 1464 In addition to that option, you need to enable signature 1465 verification for the corresponding kernel image type being 1466 loaded in order for this to work. 1467 1468config KEXEC_IMAGE_VERIFY_SIG 1469 bool "Enable Image signature verification support" 1470 default y 1471 depends on KEXEC_SIG 1472 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1473 help 1474 Enable Image signature verification support. 1475 1476comment "Support for PE file signature verification disabled" 1477 depends on KEXEC_SIG 1478 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1479 1480config CRASH_DUMP 1481 bool "Build kdump crash kernel" 1482 help 1483 Generate crash dump after being started by kexec. This should 1484 be normally only set in special crash dump kernels which are 1485 loaded in the main kernel with kexec-tools into a specially 1486 reserved region and then later executed after a crash by 1487 kdump/kexec. 1488 1489 For more details see Documentation/admin-guide/kdump/kdump.rst 1490 1491config TRANS_TABLE 1492 def_bool y 1493 depends on HIBERNATION || KEXEC_CORE 1494 1495config XEN_DOM0 1496 def_bool y 1497 depends on XEN 1498 1499config XEN 1500 bool "Xen guest support on ARM64" 1501 depends on ARM64 && OF 1502 select SWIOTLB_XEN 1503 select PARAVIRT 1504 help 1505 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1506 1507# include/linux/mmzone.h requires the following to be true: 1508# 1509# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1510# 1511# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1512# 1513# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1514# ----+-------------------+--------------+-----------------+--------------------+ 1515# 4K | 27 | 12 | 15 | 10 | 1516# 16K | 27 | 14 | 13 | 11 | 1517# 64K | 29 | 16 | 13 | 13 | 1518config ARCH_FORCE_MAX_ORDER 1519 int "Order of maximal physically contiguous allocations" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES) 1520 default "13" if ARM64_64K_PAGES 1521 default "11" if ARM64_16K_PAGES 1522 default "10" 1523 help 1524 The kernel page allocator limits the size of maximal physically 1525 contiguous allocations. The limit is called MAX_ORDER and it 1526 defines the maximal power of two of number of pages that can be 1527 allocated as a single contiguous block. This option allows 1528 overriding the default setting when ability to allocate very 1529 large blocks of physically contiguous memory is required. 1530 1531 The maximal size of allocation cannot exceed the size of the 1532 section, so the value of MAX_ORDER should satisfy 1533 1534 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1535 1536 Don't change if unsure. 1537 1538config UNMAP_KERNEL_AT_EL0 1539 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1540 default y 1541 help 1542 Speculation attacks against some high-performance processors can 1543 be used to bypass MMU permission checks and leak kernel data to 1544 userspace. This can be defended against by unmapping the kernel 1545 when running in userspace, mapping it back in on exception entry 1546 via a trampoline page in the vector table. 1547 1548 If unsure, say Y. 1549 1550config MITIGATE_SPECTRE_BRANCH_HISTORY 1551 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1552 default y 1553 help 1554 Speculation attacks against some high-performance processors can 1555 make use of branch history to influence future speculation. 1556 When taking an exception from user-space, a sequence of branches 1557 or a firmware call overwrites the branch history. 1558 1559config RODATA_FULL_DEFAULT_ENABLED 1560 bool "Apply r/o permissions of VM areas also to their linear aliases" 1561 default y 1562 help 1563 Apply read-only attributes of VM areas to the linear alias of 1564 the backing pages as well. This prevents code or read-only data 1565 from being modified (inadvertently or intentionally) via another 1566 mapping of the same memory page. This additional enhancement can 1567 be turned off at runtime by passing rodata=[off|on] (and turned on 1568 with rodata=full if this option is set to 'n') 1569 1570 This requires the linear region to be mapped down to pages, 1571 which may adversely affect performance in some cases. 1572 1573config ARM64_SW_TTBR0_PAN 1574 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1575 help 1576 Enabling this option prevents the kernel from accessing 1577 user-space memory directly by pointing TTBR0_EL1 to a reserved 1578 zeroed area and reserved ASID. The user access routines 1579 restore the valid TTBR0_EL1 temporarily. 1580 1581config ARM64_TAGGED_ADDR_ABI 1582 bool "Enable the tagged user addresses syscall ABI" 1583 default y 1584 help 1585 When this option is enabled, user applications can opt in to a 1586 relaxed ABI via prctl() allowing tagged addresses to be passed 1587 to system calls as pointer arguments. For details, see 1588 Documentation/arm64/tagged-address-abi.rst. 1589 1590menuconfig COMPAT 1591 bool "Kernel support for 32-bit EL0" 1592 depends on ARM64_4K_PAGES || EXPERT 1593 select HAVE_UID16 1594 select OLD_SIGSUSPEND3 1595 select COMPAT_OLD_SIGACTION 1596 help 1597 This option enables support for a 32-bit EL0 running under a 64-bit 1598 kernel at EL1. AArch32-specific components such as system calls, 1599 the user helper functions, VFP support and the ptrace interface are 1600 handled appropriately by the kernel. 1601 1602 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1603 that you will only be able to execute AArch32 binaries that were compiled 1604 with page size aligned segments. 1605 1606 If you want to execute 32-bit userspace applications, say Y. 1607 1608if COMPAT 1609 1610config KUSER_HELPERS 1611 bool "Enable kuser helpers page for 32-bit applications" 1612 default y 1613 help 1614 Warning: disabling this option may break 32-bit user programs. 1615 1616 Provide kuser helpers to compat tasks. The kernel provides 1617 helper code to userspace in read only form at a fixed location 1618 to allow userspace to be independent of the CPU type fitted to 1619 the system. This permits binaries to be run on ARMv4 through 1620 to ARMv8 without modification. 1621 1622 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1623 1624 However, the fixed address nature of these helpers can be used 1625 by ROP (return orientated programming) authors when creating 1626 exploits. 1627 1628 If all of the binaries and libraries which run on your platform 1629 are built specifically for your platform, and make no use of 1630 these helpers, then you can turn this option off to hinder 1631 such exploits. However, in that case, if a binary or library 1632 relying on those helpers is run, it will not function correctly. 1633 1634 Say N here only if you are absolutely certain that you do not 1635 need these helpers; otherwise, the safe option is to say Y. 1636 1637config COMPAT_VDSO 1638 bool "Enable vDSO for 32-bit applications" 1639 depends on !CPU_BIG_ENDIAN 1640 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1641 select GENERIC_COMPAT_VDSO 1642 default y 1643 help 1644 Place in the process address space of 32-bit applications an 1645 ELF shared object providing fast implementations of gettimeofday 1646 and clock_gettime. 1647 1648 You must have a 32-bit build of glibc 2.22 or later for programs 1649 to seamlessly take advantage of this. 1650 1651config THUMB2_COMPAT_VDSO 1652 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1653 depends on COMPAT_VDSO 1654 default y 1655 help 1656 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1657 otherwise with '-marm'. 1658 1659config COMPAT_ALIGNMENT_FIXUPS 1660 bool "Fix up misaligned multi-word loads and stores in user space" 1661 1662menuconfig ARMV8_DEPRECATED 1663 bool "Emulate deprecated/obsolete ARMv8 instructions" 1664 depends on SYSCTL 1665 help 1666 Legacy software support may require certain instructions 1667 that have been deprecated or obsoleted in the architecture. 1668 1669 Enable this config to enable selective emulation of these 1670 features. 1671 1672 If unsure, say Y 1673 1674if ARMV8_DEPRECATED 1675 1676config SWP_EMULATION 1677 bool "Emulate SWP/SWPB instructions" 1678 help 1679 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1680 they are always undefined. Say Y here to enable software 1681 emulation of these instructions for userspace using LDXR/STXR. 1682 This feature can be controlled at runtime with the abi.swp 1683 sysctl which is disabled by default. 1684 1685 In some older versions of glibc [<=2.8] SWP is used during futex 1686 trylock() operations with the assumption that the code will not 1687 be preempted. This invalid assumption may be more likely to fail 1688 with SWP emulation enabled, leading to deadlock of the user 1689 application. 1690 1691 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1692 on an external transaction monitoring block called a global 1693 monitor to maintain update atomicity. If your system does not 1694 implement a global monitor, this option can cause programs that 1695 perform SWP operations to uncached memory to deadlock. 1696 1697 If unsure, say Y 1698 1699config CP15_BARRIER_EMULATION 1700 bool "Emulate CP15 Barrier instructions" 1701 help 1702 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1703 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1704 strongly recommended to use the ISB, DSB, and DMB 1705 instructions instead. 1706 1707 Say Y here to enable software emulation of these 1708 instructions for AArch32 userspace code. When this option is 1709 enabled, CP15 barrier usage is traced which can help 1710 identify software that needs updating. This feature can be 1711 controlled at runtime with the abi.cp15_barrier sysctl. 1712 1713 If unsure, say Y 1714 1715config SETEND_EMULATION 1716 bool "Emulate SETEND instruction" 1717 help 1718 The SETEND instruction alters the data-endianness of the 1719 AArch32 EL0, and is deprecated in ARMv8. 1720 1721 Say Y here to enable software emulation of the instruction 1722 for AArch32 userspace code. This feature can be controlled 1723 at runtime with the abi.setend sysctl. 1724 1725 Note: All the cpus on the system must have mixed endian support at EL0 1726 for this feature to be enabled. If a new CPU - which doesn't support mixed 1727 endian - is hotplugged in after this feature has been enabled, there could 1728 be unexpected results in the applications. 1729 1730 If unsure, say Y 1731endif # ARMV8_DEPRECATED 1732 1733endif # COMPAT 1734 1735menu "ARMv8.1 architectural features" 1736 1737config ARM64_HW_AFDBM 1738 bool "Support for hardware updates of the Access and Dirty page flags" 1739 default y 1740 help 1741 The ARMv8.1 architecture extensions introduce support for 1742 hardware updates of the access and dirty information in page 1743 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1744 capable processors, accesses to pages with PTE_AF cleared will 1745 set this bit instead of raising an access flag fault. 1746 Similarly, writes to read-only pages with the DBM bit set will 1747 clear the read-only bit (AP[2]) instead of raising a 1748 permission fault. 1749 1750 Kernels built with this configuration option enabled continue 1751 to work on pre-ARMv8.1 hardware and the performance impact is 1752 minimal. If unsure, say Y. 1753 1754config ARM64_PAN 1755 bool "Enable support for Privileged Access Never (PAN)" 1756 default y 1757 help 1758 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1759 prevents the kernel or hypervisor from accessing user-space (EL0) 1760 memory directly. 1761 1762 Choosing this option will cause any unprotected (not using 1763 copy_to_user et al) memory access to fail with a permission fault. 1764 1765 The feature is detected at runtime, and will remain as a 'nop' 1766 instruction if the cpu does not implement the feature. 1767 1768config AS_HAS_LDAPR 1769 def_bool $(as-instr,.arch_extension rcpc) 1770 1771config AS_HAS_LSE_ATOMICS 1772 def_bool $(as-instr,.arch_extension lse) 1773 1774config ARM64_LSE_ATOMICS 1775 bool 1776 default ARM64_USE_LSE_ATOMICS 1777 depends on AS_HAS_LSE_ATOMICS 1778 1779config ARM64_USE_LSE_ATOMICS 1780 bool "Atomic instructions" 1781 default y 1782 help 1783 As part of the Large System Extensions, ARMv8.1 introduces new 1784 atomic instructions that are designed specifically to scale in 1785 very large systems. 1786 1787 Say Y here to make use of these instructions for the in-kernel 1788 atomic routines. This incurs a small overhead on CPUs that do 1789 not support these instructions and requires the kernel to be 1790 built with binutils >= 2.25 in order for the new instructions 1791 to be used. 1792 1793endmenu # "ARMv8.1 architectural features" 1794 1795menu "ARMv8.2 architectural features" 1796 1797config AS_HAS_ARMV8_2 1798 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1799 1800config AS_HAS_SHA3 1801 def_bool $(as-instr,.arch armv8.2-a+sha3) 1802 1803config ARM64_PMEM 1804 bool "Enable support for persistent memory" 1805 select ARCH_HAS_PMEM_API 1806 select ARCH_HAS_UACCESS_FLUSHCACHE 1807 help 1808 Say Y to enable support for the persistent memory API based on the 1809 ARMv8.2 DCPoP feature. 1810 1811 The feature is detected at runtime, and the kernel will use DC CVAC 1812 operations if DC CVAP is not supported (following the behaviour of 1813 DC CVAP itself if the system does not define a point of persistence). 1814 1815config ARM64_RAS_EXTN 1816 bool "Enable support for RAS CPU Extensions" 1817 default y 1818 help 1819 CPUs that support the Reliability, Availability and Serviceability 1820 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1821 errors, classify them and report them to software. 1822 1823 On CPUs with these extensions system software can use additional 1824 barriers to determine if faults are pending and read the 1825 classification from a new set of registers. 1826 1827 Selecting this feature will allow the kernel to use these barriers 1828 and access the new registers if the system supports the extension. 1829 Platform RAS features may additionally depend on firmware support. 1830 1831config ARM64_CNP 1832 bool "Enable support for Common Not Private (CNP) translations" 1833 default y 1834 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1835 help 1836 Common Not Private (CNP) allows translation table entries to 1837 be shared between different PEs in the same inner shareable 1838 domain, so the hardware can use this fact to optimise the 1839 caching of such entries in the TLB. 1840 1841 Selecting this option allows the CNP feature to be detected 1842 at runtime, and does not affect PEs that do not implement 1843 this feature. 1844 1845endmenu # "ARMv8.2 architectural features" 1846 1847menu "ARMv8.3 architectural features" 1848 1849config ARM64_PTR_AUTH 1850 bool "Enable support for pointer authentication" 1851 default y 1852 help 1853 Pointer authentication (part of the ARMv8.3 Extensions) provides 1854 instructions for signing and authenticating pointers against secret 1855 keys, which can be used to mitigate Return Oriented Programming (ROP) 1856 and other attacks. 1857 1858 This option enables these instructions at EL0 (i.e. for userspace). 1859 Choosing this option will cause the kernel to initialise secret keys 1860 for each process at exec() time, with these keys being 1861 context-switched along with the process. 1862 1863 The feature is detected at runtime. If the feature is not present in 1864 hardware it will not be advertised to userspace/KVM guest nor will it 1865 be enabled. 1866 1867 If the feature is present on the boot CPU but not on a late CPU, then 1868 the late CPU will be parked. Also, if the boot CPU does not have 1869 address auth and the late CPU has then the late CPU will still boot 1870 but with the feature disabled. On such a system, this option should 1871 not be selected. 1872 1873config ARM64_PTR_AUTH_KERNEL 1874 bool "Use pointer authentication for kernel" 1875 default y 1876 depends on ARM64_PTR_AUTH 1877 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1878 # Modern compilers insert a .note.gnu.property section note for PAC 1879 # which is only understood by binutils starting with version 2.33.1. 1880 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1881 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1882 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1883 help 1884 If the compiler supports the -mbranch-protection or 1885 -msign-return-address flag (e.g. GCC 7 or later), then this option 1886 will cause the kernel itself to be compiled with return address 1887 protection. In this case, and if the target hardware is known to 1888 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1889 disabled with minimal loss of protection. 1890 1891 This feature works with FUNCTION_GRAPH_TRACER option only if 1892 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1893 1894config CC_HAS_BRANCH_PROT_PAC_RET 1895 # GCC 9 or later, clang 8 or later 1896 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1897 1898config CC_HAS_SIGN_RETURN_ADDRESS 1899 # GCC 7, 8 1900 def_bool $(cc-option,-msign-return-address=all) 1901 1902config AS_HAS_ARMV8_3 1903 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1904 1905config AS_HAS_CFI_NEGATE_RA_STATE 1906 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1907 1908endmenu # "ARMv8.3 architectural features" 1909 1910menu "ARMv8.4 architectural features" 1911 1912config ARM64_AMU_EXTN 1913 bool "Enable support for the Activity Monitors Unit CPU extension" 1914 default y 1915 help 1916 The activity monitors extension is an optional extension introduced 1917 by the ARMv8.4 CPU architecture. This enables support for version 1 1918 of the activity monitors architecture, AMUv1. 1919 1920 To enable the use of this extension on CPUs that implement it, say Y. 1921 1922 Note that for architectural reasons, firmware _must_ implement AMU 1923 support when running on CPUs that present the activity monitors 1924 extension. The required support is present in: 1925 * Version 1.5 and later of the ARM Trusted Firmware 1926 1927 For kernels that have this configuration enabled but boot with broken 1928 firmware, you may need to say N here until the firmware is fixed. 1929 Otherwise you may experience firmware panics or lockups when 1930 accessing the counter registers. Even if you are not observing these 1931 symptoms, the values returned by the register reads might not 1932 correctly reflect reality. Most commonly, the value read will be 0, 1933 indicating that the counter is not enabled. 1934 1935config AS_HAS_ARMV8_4 1936 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1937 1938config ARM64_TLB_RANGE 1939 bool "Enable support for tlbi range feature" 1940 default y 1941 depends on AS_HAS_ARMV8_4 1942 help 1943 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1944 range of input addresses. 1945 1946 The feature introduces new assembly instructions, and they were 1947 support when binutils >= 2.30. 1948 1949endmenu # "ARMv8.4 architectural features" 1950 1951menu "ARMv8.5 architectural features" 1952 1953config AS_HAS_ARMV8_5 1954 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1955 1956config ARM64_BTI 1957 bool "Branch Target Identification support" 1958 default y 1959 help 1960 Branch Target Identification (part of the ARMv8.5 Extensions) 1961 provides a mechanism to limit the set of locations to which computed 1962 branch instructions such as BR or BLR can jump. 1963 1964 To make use of BTI on CPUs that support it, say Y. 1965 1966 BTI is intended to provide complementary protection to other control 1967 flow integrity protection mechanisms, such as the Pointer 1968 authentication mechanism provided as part of the ARMv8.3 Extensions. 1969 For this reason, it does not make sense to enable this option without 1970 also enabling support for pointer authentication. Thus, when 1971 enabling this option you should also select ARM64_PTR_AUTH=y. 1972 1973 Userspace binaries must also be specifically compiled to make use of 1974 this mechanism. If you say N here or the hardware does not support 1975 BTI, such binaries can still run, but you get no additional 1976 enforcement of branch destinations. 1977 1978config ARM64_BTI_KERNEL 1979 bool "Use Branch Target Identification for kernel" 1980 default y 1981 depends on ARM64_BTI 1982 depends on ARM64_PTR_AUTH_KERNEL 1983 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1984 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1985 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1986 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 1987 depends on !CC_IS_GCC 1988 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 1989 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 1990 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1991 help 1992 Build the kernel with Branch Target Identification annotations 1993 and enable enforcement of this for kernel code. When this option 1994 is enabled and the system supports BTI all kernel code including 1995 modular code must have BTI enabled. 1996 1997config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1998 # GCC 9 or later, clang 8 or later 1999 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2000 2001config ARM64_E0PD 2002 bool "Enable support for E0PD" 2003 default y 2004 help 2005 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2006 that EL0 accesses made via TTBR1 always fault in constant time, 2007 providing similar benefits to KASLR as those provided by KPTI, but 2008 with lower overhead and without disrupting legitimate access to 2009 kernel memory such as SPE. 2010 2011 This option enables E0PD for TTBR1 where available. 2012 2013config ARM64_AS_HAS_MTE 2014 # Initial support for MTE went in binutils 2.32.0, checked with 2015 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2016 # as a late addition to the final architecture spec (LDGM/STGM) 2017 # is only supported in the newer 2.32.x and 2.33 binutils 2018 # versions, hence the extra "stgm" instruction check below. 2019 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2020 2021config ARM64_MTE 2022 bool "Memory Tagging Extension support" 2023 default y 2024 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2025 depends on AS_HAS_ARMV8_5 2026 depends on AS_HAS_LSE_ATOMICS 2027 # Required for tag checking in the uaccess routines 2028 depends on ARM64_PAN 2029 select ARCH_HAS_SUBPAGE_FAULTS 2030 select ARCH_USES_HIGH_VMA_FLAGS 2031 select ARCH_USES_PG_ARCH_X 2032 help 2033 Memory Tagging (part of the ARMv8.5 Extensions) provides 2034 architectural support for run-time, always-on detection of 2035 various classes of memory error to aid with software debugging 2036 to eliminate vulnerabilities arising from memory-unsafe 2037 languages. 2038 2039 This option enables the support for the Memory Tagging 2040 Extension at EL0 (i.e. for userspace). 2041 2042 Selecting this option allows the feature to be detected at 2043 runtime. Any secondary CPU not implementing this feature will 2044 not be allowed a late bring-up. 2045 2046 Userspace binaries that want to use this feature must 2047 explicitly opt in. The mechanism for the userspace is 2048 described in: 2049 2050 Documentation/arm64/memory-tagging-extension.rst. 2051 2052endmenu # "ARMv8.5 architectural features" 2053 2054menu "ARMv8.7 architectural features" 2055 2056config ARM64_EPAN 2057 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2058 default y 2059 depends on ARM64_PAN 2060 help 2061 Enhanced Privileged Access Never (EPAN) allows Privileged 2062 Access Never to be used with Execute-only mappings. 2063 2064 The feature is detected at runtime, and will remain disabled 2065 if the cpu does not implement the feature. 2066endmenu # "ARMv8.7 architectural features" 2067 2068config ARM64_SVE 2069 bool "ARM Scalable Vector Extension support" 2070 default y 2071 help 2072 The Scalable Vector Extension (SVE) is an extension to the AArch64 2073 execution state which complements and extends the SIMD functionality 2074 of the base architecture to support much larger vectors and to enable 2075 additional vectorisation opportunities. 2076 2077 To enable use of this extension on CPUs that implement it, say Y. 2078 2079 On CPUs that support the SVE2 extensions, this option will enable 2080 those too. 2081 2082 Note that for architectural reasons, firmware _must_ implement SVE 2083 support when running on SVE capable hardware. The required support 2084 is present in: 2085 2086 * version 1.5 and later of the ARM Trusted Firmware 2087 * the AArch64 boot wrapper since commit 5e1261e08abf 2088 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2089 2090 For other firmware implementations, consult the firmware documentation 2091 or vendor. 2092 2093 If you need the kernel to boot on SVE-capable hardware with broken 2094 firmware, you may need to say N here until you get your firmware 2095 fixed. Otherwise, you may experience firmware panics or lockups when 2096 booting the kernel. If unsure and you are not observing these 2097 symptoms, you should assume that it is safe to say Y. 2098 2099config ARM64_SME 2100 bool "ARM Scalable Matrix Extension support" 2101 default y 2102 depends on ARM64_SVE 2103 help 2104 The Scalable Matrix Extension (SME) is an extension to the AArch64 2105 execution state which utilises a substantial subset of the SVE 2106 instruction set, together with the addition of new architectural 2107 register state capable of holding two dimensional matrix tiles to 2108 enable various matrix operations. 2109 2110config ARM64_MODULE_PLTS 2111 bool "Use PLTs to allow module memory to spill over into vmalloc area" 2112 depends on MODULES 2113 select HAVE_MOD_ARCH_SPECIFIC 2114 help 2115 Allocate PLTs when loading modules so that jumps and calls whose 2116 targets are too far away for their relative offsets to be encoded 2117 in the instructions themselves can be bounced via veneers in the 2118 module's PLT. This allows modules to be allocated in the generic 2119 vmalloc area after the dedicated module memory area has been 2120 exhausted. 2121 2122 When running with address space randomization (KASLR), the module 2123 region itself may be too far away for ordinary relative jumps and 2124 calls, and so in that case, module PLTs are required and cannot be 2125 disabled. 2126 2127 Specific errata workaround(s) might also force module PLTs to be 2128 enabled (ARM64_ERRATUM_843419). 2129 2130config ARM64_PSEUDO_NMI 2131 bool "Support for NMI-like interrupts" 2132 select ARM_GIC_V3 2133 help 2134 Adds support for mimicking Non-Maskable Interrupts through the use of 2135 GIC interrupt priority. This support requires version 3 or later of 2136 ARM GIC. 2137 2138 This high priority configuration for interrupts needs to be 2139 explicitly enabled by setting the kernel parameter 2140 "irqchip.gicv3_pseudo_nmi" to 1. 2141 2142 If unsure, say N 2143 2144if ARM64_PSEUDO_NMI 2145config ARM64_DEBUG_PRIORITY_MASKING 2146 bool "Debug interrupt priority masking" 2147 help 2148 This adds runtime checks to functions enabling/disabling 2149 interrupts when using priority masking. The additional checks verify 2150 the validity of ICC_PMR_EL1 when calling concerned functions. 2151 2152 If unsure, say N 2153endif # ARM64_PSEUDO_NMI 2154 2155config RELOCATABLE 2156 bool "Build a relocatable kernel image" if EXPERT 2157 select ARCH_HAS_RELR 2158 default y 2159 help 2160 This builds the kernel as a Position Independent Executable (PIE), 2161 which retains all relocation metadata required to relocate the 2162 kernel binary at runtime to a different virtual address than the 2163 address it was linked at. 2164 Since AArch64 uses the RELA relocation format, this requires a 2165 relocation pass at runtime even if the kernel is loaded at the 2166 same address it was linked at. 2167 2168config RANDOMIZE_BASE 2169 bool "Randomize the address of the kernel image" 2170 select ARM64_MODULE_PLTS if MODULES 2171 select RELOCATABLE 2172 help 2173 Randomizes the virtual address at which the kernel image is 2174 loaded, as a security feature that deters exploit attempts 2175 relying on knowledge of the location of kernel internals. 2176 2177 It is the bootloader's job to provide entropy, by passing a 2178 random u64 value in /chosen/kaslr-seed at kernel entry. 2179 2180 When booting via the UEFI stub, it will invoke the firmware's 2181 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2182 to the kernel proper. In addition, it will randomise the physical 2183 location of the kernel Image as well. 2184 2185 If unsure, say N. 2186 2187config RANDOMIZE_MODULE_REGION_FULL 2188 bool "Randomize the module region over a 2 GB range" 2189 depends on RANDOMIZE_BASE 2190 default y 2191 help 2192 Randomizes the location of the module region inside a 2 GB window 2193 covering the core kernel. This way, it is less likely for modules 2194 to leak information about the location of core kernel data structures 2195 but it does imply that function calls between modules and the core 2196 kernel will need to be resolved via veneers in the module PLT. 2197 2198 When this option is not set, the module region will be randomized over 2199 a limited range that contains the [_stext, _etext] interval of the 2200 core kernel, so branch relocations are almost always in range unless 2201 ARM64_MODULE_PLTS is enabled and the region is exhausted. In this 2202 particular case of region exhaustion, modules might be able to fall 2203 back to a larger 2GB area. 2204 2205config CC_HAVE_STACKPROTECTOR_SYSREG 2206 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2207 2208config STACKPROTECTOR_PER_TASK 2209 def_bool y 2210 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2211 2212config UNWIND_PATCH_PAC_INTO_SCS 2213 bool "Enable shadow call stack dynamically using code patching" 2214 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2215 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2216 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2217 depends on SHADOW_CALL_STACK 2218 select UNWIND_TABLES 2219 select DYNAMIC_SCS 2220 2221endmenu # "Kernel Features" 2222 2223menu "Boot options" 2224 2225config ARM64_ACPI_PARKING_PROTOCOL 2226 bool "Enable support for the ARM64 ACPI parking protocol" 2227 depends on ACPI 2228 help 2229 Enable support for the ARM64 ACPI parking protocol. If disabled 2230 the kernel will not allow booting through the ARM64 ACPI parking 2231 protocol even if the corresponding data is present in the ACPI 2232 MADT table. 2233 2234config CMDLINE 2235 string "Default kernel command string" 2236 default "" 2237 help 2238 Provide a set of default command-line options at build time by 2239 entering them here. As a minimum, you should specify the the 2240 root device (e.g. root=/dev/nfs). 2241 2242choice 2243 prompt "Kernel command line type" if CMDLINE != "" 2244 default CMDLINE_FROM_BOOTLOADER 2245 help 2246 Choose how the kernel will handle the provided default kernel 2247 command line string. 2248 2249config CMDLINE_FROM_BOOTLOADER 2250 bool "Use bootloader kernel arguments if available" 2251 help 2252 Uses the command-line options passed by the boot loader. If 2253 the boot loader doesn't provide any, the default kernel command 2254 string provided in CMDLINE will be used. 2255 2256config CMDLINE_FORCE 2257 bool "Always use the default kernel command string" 2258 help 2259 Always use the default kernel command string, even if the boot 2260 loader passes other arguments to the kernel. 2261 This is useful if you cannot or don't want to change the 2262 command-line options your boot loader passes to the kernel. 2263 2264endchoice 2265 2266config EFI_STUB 2267 bool 2268 2269config EFI 2270 bool "UEFI runtime support" 2271 depends on OF && !CPU_BIG_ENDIAN 2272 depends on KERNEL_MODE_NEON 2273 select ARCH_SUPPORTS_ACPI 2274 select LIBFDT 2275 select UCS2_STRING 2276 select EFI_PARAMS_FROM_FDT 2277 select EFI_RUNTIME_WRAPPERS 2278 select EFI_STUB 2279 select EFI_GENERIC_STUB 2280 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2281 default y 2282 help 2283 This option provides support for runtime services provided 2284 by UEFI firmware (such as non-volatile variables, realtime 2285 clock, and platform reset). A UEFI stub is also provided to 2286 allow the kernel to be booted as an EFI application. This 2287 is only useful on systems that have UEFI firmware. 2288 2289config DMI 2290 bool "Enable support for SMBIOS (DMI) tables" 2291 depends on EFI 2292 default y 2293 help 2294 This enables SMBIOS/DMI feature for systems. 2295 2296 This option is only useful on systems that have UEFI firmware. 2297 However, even with this option, the resultant kernel should 2298 continue to boot on existing non-UEFI platforms. 2299 2300endmenu # "Boot options" 2301 2302menu "Power management options" 2303 2304source "kernel/power/Kconfig" 2305 2306config ARCH_HIBERNATION_POSSIBLE 2307 def_bool y 2308 depends on CPU_PM 2309 2310config ARCH_HIBERNATION_HEADER 2311 def_bool y 2312 depends on HIBERNATION 2313 2314config ARCH_SUSPEND_POSSIBLE 2315 def_bool y 2316 2317endmenu # "Power management options" 2318 2319menu "CPU Power Management" 2320 2321source "drivers/cpuidle/Kconfig" 2322 2323source "drivers/cpufreq/Kconfig" 2324 2325endmenu # "CPU Power Management" 2326 2327source "drivers/acpi/Kconfig" 2328 2329source "arch/arm64/kvm/Kconfig" 2330 2331