1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_IORT if ACPI 9 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 10 select ACPI_MCFG if (ACPI && PCI) 11 select ACPI_SPCR_TABLE if ACPI 12 select ACPI_PPTT if ACPI 13 select ARCH_HAS_DEBUG_WX 14 select ARCH_BINFMT_ELF_EXTRA_PHDRS 15 select ARCH_BINFMT_ELF_STATE 16 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CURRENT_STACK_POINTER 24 select ARCH_HAS_DEBUG_VIRTUAL 25 select ARCH_HAS_DEBUG_VM_PGTABLE 26 select ARCH_HAS_DMA_PREP_COHERENT 27 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 28 select ARCH_HAS_FAST_MULTIPLIER 29 select ARCH_HAS_FORTIFY_SOURCE 30 select ARCH_HAS_GCOV_PROFILE_ALL 31 select ARCH_HAS_GIGANTIC_PAGE 32 select ARCH_HAS_KCOV 33 select ARCH_HAS_KEEPINITRD 34 select ARCH_HAS_MEMBARRIER_SYNC_CORE 35 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 36 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 37 select ARCH_HAS_PTE_DEVMAP 38 select ARCH_HAS_PTE_SPECIAL 39 select ARCH_HAS_SETUP_DMA_OPS 40 select ARCH_HAS_SET_DIRECT_MAP 41 select ARCH_HAS_SET_MEMORY 42 select ARCH_STACKWALK 43 select ARCH_HAS_STRICT_KERNEL_RWX 44 select ARCH_HAS_STRICT_MODULE_RWX 45 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 46 select ARCH_HAS_SYNC_DMA_FOR_CPU 47 select ARCH_HAS_SYSCALL_WRAPPER 48 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 49 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 50 select ARCH_HAS_ZONE_DMA_SET if EXPERT 51 select ARCH_HAVE_ELF_PROT 52 select ARCH_HAVE_NMI_SAFE_CMPXCHG 53 select ARCH_HAVE_TRACE_MMIO_ACCESS 54 select ARCH_INLINE_READ_LOCK if !PREEMPTION 55 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 56 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 57 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 58 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 59 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 60 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 61 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 62 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 63 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 64 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 65 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 66 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 67 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 68 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 69 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 70 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 71 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 72 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 73 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_KEEP_MEMBLOCK 81 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 82 select ARCH_USE_CMPXCHG_LOCKREF 83 select ARCH_USE_GNU_PROPERTY 84 select ARCH_USE_MEMTEST 85 select ARCH_USE_QUEUED_RWLOCKS 86 select ARCH_USE_QUEUED_SPINLOCKS 87 select ARCH_USE_SYM_ANNOTATIONS 88 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 89 select ARCH_SUPPORTS_HUGETLBFS 90 select ARCH_SUPPORTS_MEMORY_FAILURE 91 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 92 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 93 select ARCH_SUPPORTS_LTO_CLANG_THIN 94 select ARCH_SUPPORTS_CFI_CLANG 95 select ARCH_SUPPORTS_ATOMIC_RMW 96 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 97 select ARCH_SUPPORTS_NUMA_BALANCING 98 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 99 select ARCH_SUPPORTS_PER_VMA_LOCK 100 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 101 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 102 select ARCH_WANT_DEFAULT_BPF_JIT 103 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 104 select ARCH_WANT_FRAME_POINTERS 105 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 106 select ARCH_WANT_LD_ORPHAN_WARN 107 select ARCH_WANTS_NO_INSTR 108 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 109 select ARCH_HAS_UBSAN_SANITIZE_ALL 110 select ARM_AMBA 111 select ARM_ARCH_TIMER 112 select ARM_GIC 113 select AUDIT_ARCH_COMPAT_GENERIC 114 select ARM_GIC_V2M if PCI 115 select ARM_GIC_V3 116 select ARM_GIC_V3_ITS if PCI 117 select ARM_PSCI_FW 118 select BUILDTIME_TABLE_SORT 119 select CLONE_BACKWARDS 120 select COMMON_CLK 121 select CPU_PM if (SUSPEND || CPU_IDLE) 122 select CRC32 123 select DCACHE_WORD_ACCESS 124 select DYNAMIC_FTRACE if FUNCTION_TRACER 125 select DMA_BOUNCE_UNALIGNED_KMALLOC 126 select DMA_DIRECT_REMAP 127 select EDAC_SUPPORT 128 select FRAME_POINTER 129 select FUNCTION_ALIGNMENT_4B 130 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 131 select GENERIC_ALLOCATOR 132 select GENERIC_ARCH_TOPOLOGY 133 select GENERIC_CLOCKEVENTS_BROADCAST 134 select GENERIC_CPU_AUTOPROBE 135 select GENERIC_CPU_VULNERABILITIES 136 select GENERIC_EARLY_IOREMAP 137 select GENERIC_IDLE_POLL_SETUP 138 select GENERIC_IOREMAP 139 select GENERIC_IRQ_IPI 140 select GENERIC_IRQ_PROBE 141 select GENERIC_IRQ_SHOW 142 select GENERIC_IRQ_SHOW_LEVEL 143 select GENERIC_LIB_DEVMEM_IS_ALLOWED 144 select GENERIC_PCI_IOMAP 145 select GENERIC_PTDUMP 146 select GENERIC_SCHED_CLOCK 147 select GENERIC_SMP_IDLE_THREAD 148 select GENERIC_TIME_VSYSCALL 149 select GENERIC_GETTIMEOFDAY 150 select GENERIC_VDSO_TIME_NS 151 select HARDIRQS_SW_RESEND 152 select HAS_IOPORT 153 select HAVE_MOVE_PMD 154 select HAVE_MOVE_PUD 155 select HAVE_PCI 156 select HAVE_ACPI_APEI if (ACPI && EFI) 157 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 158 select HAVE_ARCH_AUDITSYSCALL 159 select HAVE_ARCH_BITREVERSE 160 select HAVE_ARCH_COMPILER_H 161 select HAVE_ARCH_HUGE_VMALLOC 162 select HAVE_ARCH_HUGE_VMAP 163 select HAVE_ARCH_JUMP_LABEL 164 select HAVE_ARCH_JUMP_LABEL_RELATIVE 165 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 166 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 167 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 168 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 169 # Some instrumentation may be unsound, hence EXPERT 170 select HAVE_ARCH_KCSAN if EXPERT 171 select HAVE_ARCH_KFENCE 172 select HAVE_ARCH_KGDB 173 select HAVE_ARCH_MMAP_RND_BITS 174 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 175 select HAVE_ARCH_PREL32_RELOCATIONS 176 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 177 select HAVE_ARCH_SECCOMP_FILTER 178 select HAVE_ARCH_STACKLEAK 179 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 180 select HAVE_ARCH_TRACEHOOK 181 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 182 select HAVE_ARCH_VMAP_STACK 183 select HAVE_ARM_SMCCC 184 select HAVE_ASM_MODVERSIONS 185 select HAVE_EBPF_JIT 186 select HAVE_C_RECORDMCOUNT 187 select HAVE_CMPXCHG_DOUBLE 188 select HAVE_CMPXCHG_LOCAL 189 select HAVE_CONTEXT_TRACKING_USER 190 select HAVE_DEBUG_KMEMLEAK 191 select HAVE_DMA_CONTIGUOUS 192 select HAVE_DYNAMIC_FTRACE 193 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 194 if $(cc-option,-fpatchable-function-entry=2) 195 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 196 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 197 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 198 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 199 !CC_OPTIMIZE_FOR_SIZE) 200 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 201 if DYNAMIC_FTRACE_WITH_ARGS 202 select HAVE_SAMPLE_FTRACE_DIRECT 203 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 204 select HAVE_EFFICIENT_UNALIGNED_ACCESS 205 select HAVE_FAST_GUP 206 select HAVE_FTRACE_MCOUNT_RECORD 207 select HAVE_FUNCTION_TRACER 208 select HAVE_FUNCTION_ERROR_INJECTION 209 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 210 select HAVE_FUNCTION_GRAPH_TRACER 211 select HAVE_GCC_PLUGINS 212 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 213 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 214 select HAVE_HW_BREAKPOINT if PERF_EVENTS 215 select HAVE_IOREMAP_PROT 216 select HAVE_IRQ_TIME_ACCOUNTING 217 select HAVE_KVM 218 select HAVE_MOD_ARCH_SPECIFIC 219 select HAVE_NMI 220 select HAVE_PERF_EVENTS 221 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 222 select HAVE_PERF_REGS 223 select HAVE_PERF_USER_STACK_DUMP 224 select HAVE_PREEMPT_DYNAMIC_KEY 225 select HAVE_REGS_AND_STACK_ACCESS_API 226 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 227 select HAVE_FUNCTION_ARG_ACCESS_API 228 select MMU_GATHER_RCU_TABLE_FREE 229 select HAVE_RSEQ 230 select HAVE_STACKPROTECTOR 231 select HAVE_SYSCALL_TRACEPOINTS 232 select HAVE_KPROBES 233 select HAVE_KRETPROBES 234 select HAVE_GENERIC_VDSO 235 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 236 select IRQ_DOMAIN 237 select IRQ_FORCED_THREADING 238 select KASAN_VMALLOC if KASAN 239 select LOCK_MM_AND_FIND_VMA 240 select MODULES_USE_ELF_RELA 241 select NEED_DMA_MAP_STATE 242 select NEED_SG_DMA_LENGTH 243 select OF 244 select OF_EARLY_FLATTREE 245 select PCI_DOMAINS_GENERIC if PCI 246 select PCI_ECAM if (ACPI && PCI) 247 select PCI_SYSCALL if PCI 248 select POWER_RESET 249 select POWER_SUPPLY 250 select SPARSE_IRQ 251 select SWIOTLB 252 select SYSCTL_EXCEPTION_TRACE 253 select THREAD_INFO_IN_TASK 254 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 255 select TRACE_IRQFLAGS_SUPPORT 256 select TRACE_IRQFLAGS_NMI_SUPPORT 257 select HAVE_SOFTIRQ_ON_OWN_STACK 258 help 259 ARM 64-bit (AArch64) Linux support. 260 261config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 262 def_bool CC_IS_CLANG 263 # https://github.com/ClangBuiltLinux/linux/issues/1507 264 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 265 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 266 267config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 268 def_bool CC_IS_GCC 269 depends on $(cc-option,-fpatchable-function-entry=2) 270 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 271 272config 64BIT 273 def_bool y 274 275config MMU 276 def_bool y 277 278config ARM64_PAGE_SHIFT 279 int 280 default 16 if ARM64_64K_PAGES 281 default 14 if ARM64_16K_PAGES 282 default 12 283 284config ARM64_CONT_PTE_SHIFT 285 int 286 default 5 if ARM64_64K_PAGES 287 default 7 if ARM64_16K_PAGES 288 default 4 289 290config ARM64_CONT_PMD_SHIFT 291 int 292 default 5 if ARM64_64K_PAGES 293 default 5 if ARM64_16K_PAGES 294 default 4 295 296config ARCH_MMAP_RND_BITS_MIN 297 default 14 if ARM64_64K_PAGES 298 default 16 if ARM64_16K_PAGES 299 default 18 300 301# max bits determined by the following formula: 302# VA_BITS - PAGE_SHIFT - 3 303config ARCH_MMAP_RND_BITS_MAX 304 default 19 if ARM64_VA_BITS=36 305 default 24 if ARM64_VA_BITS=39 306 default 27 if ARM64_VA_BITS=42 307 default 30 if ARM64_VA_BITS=47 308 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 309 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 310 default 33 if ARM64_VA_BITS=48 311 default 14 if ARM64_64K_PAGES 312 default 16 if ARM64_16K_PAGES 313 default 18 314 315config ARCH_MMAP_RND_COMPAT_BITS_MIN 316 default 7 if ARM64_64K_PAGES 317 default 9 if ARM64_16K_PAGES 318 default 11 319 320config ARCH_MMAP_RND_COMPAT_BITS_MAX 321 default 16 322 323config NO_IOPORT_MAP 324 def_bool y if !PCI 325 326config STACKTRACE_SUPPORT 327 def_bool y 328 329config ILLEGAL_POINTER_VALUE 330 hex 331 default 0xdead000000000000 332 333config LOCKDEP_SUPPORT 334 def_bool y 335 336config GENERIC_BUG 337 def_bool y 338 depends on BUG 339 340config GENERIC_BUG_RELATIVE_POINTERS 341 def_bool y 342 depends on GENERIC_BUG 343 344config GENERIC_HWEIGHT 345 def_bool y 346 347config GENERIC_CSUM 348 def_bool y 349 350config GENERIC_CALIBRATE_DELAY 351 def_bool y 352 353config SMP 354 def_bool y 355 356config KERNEL_MODE_NEON 357 def_bool y 358 359config FIX_EARLYCON_MEM 360 def_bool y 361 362config PGTABLE_LEVELS 363 int 364 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 365 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 366 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 367 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 368 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 369 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 370 371config ARCH_SUPPORTS_UPROBES 372 def_bool y 373 374config ARCH_PROC_KCORE_TEXT 375 def_bool y 376 377config BROKEN_GAS_INST 378 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 379 380config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 381 bool 382 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 383 # https://reviews.llvm.org/D75044 384 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 385 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 386 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 387 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 388 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 389 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 390 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 391 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 392 default n 393 394config KASAN_SHADOW_OFFSET 395 hex 396 depends on KASAN_GENERIC || KASAN_SW_TAGS 397 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 398 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 399 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 400 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 401 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 402 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 403 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 404 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 405 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 406 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 407 default 0xffffffffffffffff 408 409config UNWIND_TABLES 410 bool 411 412source "arch/arm64/Kconfig.platforms" 413 414menu "Kernel Features" 415 416menu "ARM errata workarounds via the alternatives framework" 417 418config AMPERE_ERRATUM_AC03_CPU_38 419 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 420 default y 421 help 422 This option adds an alternative code sequence to work around Ampere 423 erratum AC03_CPU_38 on AmpereOne. 424 425 The affected design reports FEAT_HAFDBS as not implemented in 426 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 427 as required by the architecture. The unadvertised HAFDBS 428 implementation suffers from an additional erratum where hardware 429 A/D updates can occur after a PTE has been marked invalid. 430 431 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 432 which avoids enabling unadvertised hardware Access Flag management 433 at stage-2. 434 435 If unsure, say Y. 436 437config ARM64_WORKAROUND_CLEAN_CACHE 438 bool 439 440config ARM64_ERRATUM_826319 441 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 442 default y 443 select ARM64_WORKAROUND_CLEAN_CACHE 444 help 445 This option adds an alternative code sequence to work around ARM 446 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 447 AXI master interface and an L2 cache. 448 449 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 450 and is unable to accept a certain write via this interface, it will 451 not progress on read data presented on the read data channel and the 452 system can deadlock. 453 454 The workaround promotes data cache clean instructions to 455 data cache clean-and-invalidate. 456 Please note that this does not necessarily enable the workaround, 457 as it depends on the alternative framework, which will only patch 458 the kernel if an affected CPU is detected. 459 460 If unsure, say Y. 461 462config ARM64_ERRATUM_827319 463 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 464 default y 465 select ARM64_WORKAROUND_CLEAN_CACHE 466 help 467 This option adds an alternative code sequence to work around ARM 468 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 469 master interface and an L2 cache. 470 471 Under certain conditions this erratum can cause a clean line eviction 472 to occur at the same time as another transaction to the same address 473 on the AMBA 5 CHI interface, which can cause data corruption if the 474 interconnect reorders the two transactions. 475 476 The workaround promotes data cache clean instructions to 477 data cache clean-and-invalidate. 478 Please note that this does not necessarily enable the workaround, 479 as it depends on the alternative framework, which will only patch 480 the kernel if an affected CPU is detected. 481 482 If unsure, say Y. 483 484config ARM64_ERRATUM_824069 485 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 486 default y 487 select ARM64_WORKAROUND_CLEAN_CACHE 488 help 489 This option adds an alternative code sequence to work around ARM 490 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 491 to a coherent interconnect. 492 493 If a Cortex-A53 processor is executing a store or prefetch for 494 write instruction at the same time as a processor in another 495 cluster is executing a cache maintenance operation to the same 496 address, then this erratum might cause a clean cache line to be 497 incorrectly marked as dirty. 498 499 The workaround promotes data cache clean instructions to 500 data cache clean-and-invalidate. 501 Please note that this option does not necessarily enable the 502 workaround, as it depends on the alternative framework, which will 503 only patch the kernel if an affected CPU is detected. 504 505 If unsure, say Y. 506 507config ARM64_ERRATUM_819472 508 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 509 default y 510 select ARM64_WORKAROUND_CLEAN_CACHE 511 help 512 This option adds an alternative code sequence to work around ARM 513 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 514 present when it is connected to a coherent interconnect. 515 516 If the processor is executing a load and store exclusive sequence at 517 the same time as a processor in another cluster is executing a cache 518 maintenance operation to the same address, then this erratum might 519 cause data corruption. 520 521 The workaround promotes data cache clean instructions to 522 data cache clean-and-invalidate. 523 Please note that this does not necessarily enable the workaround, 524 as it depends on the alternative framework, which will only patch 525 the kernel if an affected CPU is detected. 526 527 If unsure, say Y. 528 529config ARM64_ERRATUM_832075 530 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 531 default y 532 help 533 This option adds an alternative code sequence to work around ARM 534 erratum 832075 on Cortex-A57 parts up to r1p2. 535 536 Affected Cortex-A57 parts might deadlock when exclusive load/store 537 instructions to Write-Back memory are mixed with Device loads. 538 539 The workaround is to promote device loads to use Load-Acquire 540 semantics. 541 Please note that this does not necessarily enable the workaround, 542 as it depends on the alternative framework, which will only patch 543 the kernel if an affected CPU is detected. 544 545 If unsure, say Y. 546 547config ARM64_ERRATUM_834220 548 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 549 depends on KVM 550 default y 551 help 552 This option adds an alternative code sequence to work around ARM 553 erratum 834220 on Cortex-A57 parts up to r1p2. 554 555 Affected Cortex-A57 parts might report a Stage 2 translation 556 fault as the result of a Stage 1 fault for load crossing a 557 page boundary when there is a permission or device memory 558 alignment fault at Stage 1 and a translation fault at Stage 2. 559 560 The workaround is to verify that the Stage 1 translation 561 doesn't generate a fault before handling the Stage 2 fault. 562 Please note that this does not necessarily enable the workaround, 563 as it depends on the alternative framework, which will only patch 564 the kernel if an affected CPU is detected. 565 566 If unsure, say Y. 567 568config ARM64_ERRATUM_1742098 569 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 570 depends on COMPAT 571 default y 572 help 573 This option removes the AES hwcap for aarch32 user-space to 574 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 575 576 Affected parts may corrupt the AES state if an interrupt is 577 taken between a pair of AES instructions. These instructions 578 are only present if the cryptography extensions are present. 579 All software should have a fallback implementation for CPUs 580 that don't implement the cryptography extensions. 581 582 If unsure, say Y. 583 584config ARM64_ERRATUM_845719 585 bool "Cortex-A53: 845719: a load might read incorrect data" 586 depends on COMPAT 587 default y 588 help 589 This option adds an alternative code sequence to work around ARM 590 erratum 845719 on Cortex-A53 parts up to r0p4. 591 592 When running a compat (AArch32) userspace on an affected Cortex-A53 593 part, a load at EL0 from a virtual address that matches the bottom 32 594 bits of the virtual address used by a recent load at (AArch64) EL1 595 might return incorrect data. 596 597 The workaround is to write the contextidr_el1 register on exception 598 return to a 32-bit task. 599 Please note that this does not necessarily enable the workaround, 600 as it depends on the alternative framework, which will only patch 601 the kernel if an affected CPU is detected. 602 603 If unsure, say Y. 604 605config ARM64_ERRATUM_843419 606 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 607 default y 608 help 609 This option links the kernel with '--fix-cortex-a53-843419' and 610 enables PLT support to replace certain ADRP instructions, which can 611 cause subsequent memory accesses to use an incorrect address on 612 Cortex-A53 parts up to r0p4. 613 614 If unsure, say Y. 615 616config ARM64_LD_HAS_FIX_ERRATUM_843419 617 def_bool $(ld-option,--fix-cortex-a53-843419) 618 619config ARM64_ERRATUM_1024718 620 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 621 default y 622 help 623 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 624 625 Affected Cortex-A55 cores (all revisions) could cause incorrect 626 update of the hardware dirty bit when the DBM/AP bits are updated 627 without a break-before-make. The workaround is to disable the usage 628 of hardware DBM locally on the affected cores. CPUs not affected by 629 this erratum will continue to use the feature. 630 631 If unsure, say Y. 632 633config ARM64_ERRATUM_1418040 634 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 635 default y 636 depends on COMPAT 637 help 638 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 639 errata 1188873 and 1418040. 640 641 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 642 cause register corruption when accessing the timer registers 643 from AArch32 userspace. 644 645 If unsure, say Y. 646 647config ARM64_WORKAROUND_SPECULATIVE_AT 648 bool 649 650config ARM64_ERRATUM_1165522 651 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 652 default y 653 select ARM64_WORKAROUND_SPECULATIVE_AT 654 help 655 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 656 657 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 658 corrupted TLBs by speculating an AT instruction during a guest 659 context switch. 660 661 If unsure, say Y. 662 663config ARM64_ERRATUM_1319367 664 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 665 default y 666 select ARM64_WORKAROUND_SPECULATIVE_AT 667 help 668 This option adds work arounds for ARM Cortex-A57 erratum 1319537 669 and A72 erratum 1319367 670 671 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 672 speculating an AT instruction during a guest context switch. 673 674 If unsure, say Y. 675 676config ARM64_ERRATUM_1530923 677 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 678 default y 679 select ARM64_WORKAROUND_SPECULATIVE_AT 680 help 681 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 682 683 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 684 corrupted TLBs by speculating an AT instruction during a guest 685 context switch. 686 687 If unsure, say Y. 688 689config ARM64_WORKAROUND_REPEAT_TLBI 690 bool 691 692config ARM64_ERRATUM_2441007 693 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 694 default y 695 select ARM64_WORKAROUND_REPEAT_TLBI 696 help 697 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 698 699 Under very rare circumstances, affected Cortex-A55 CPUs 700 may not handle a race between a break-before-make sequence on one 701 CPU, and another CPU accessing the same page. This could allow a 702 store to a page that has been unmapped. 703 704 Work around this by adding the affected CPUs to the list that needs 705 TLB sequences to be done twice. 706 707 If unsure, say Y. 708 709config ARM64_ERRATUM_1286807 710 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 711 default y 712 select ARM64_WORKAROUND_REPEAT_TLBI 713 help 714 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 715 716 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 717 address for a cacheable mapping of a location is being 718 accessed by a core while another core is remapping the virtual 719 address to a new physical page using the recommended 720 break-before-make sequence, then under very rare circumstances 721 TLBI+DSB completes before a read using the translation being 722 invalidated has been observed by other observers. The 723 workaround repeats the TLBI+DSB operation. 724 725config ARM64_ERRATUM_1463225 726 bool "Cortex-A76: Software Step might prevent interrupt recognition" 727 default y 728 help 729 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 730 731 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 732 of a system call instruction (SVC) can prevent recognition of 733 subsequent interrupts when software stepping is disabled in the 734 exception handler of the system call and either kernel debugging 735 is enabled or VHE is in use. 736 737 Work around the erratum by triggering a dummy step exception 738 when handling a system call from a task that is being stepped 739 in a VHE configuration of the kernel. 740 741 If unsure, say Y. 742 743config ARM64_ERRATUM_1542419 744 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 745 default y 746 help 747 This option adds a workaround for ARM Neoverse-N1 erratum 748 1542419. 749 750 Affected Neoverse-N1 cores could execute a stale instruction when 751 modified by another CPU. The workaround depends on a firmware 752 counterpart. 753 754 Workaround the issue by hiding the DIC feature from EL0. This 755 forces user-space to perform cache maintenance. 756 757 If unsure, say Y. 758 759config ARM64_ERRATUM_1508412 760 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 761 default y 762 help 763 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 764 765 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 766 of a store-exclusive or read of PAR_EL1 and a load with device or 767 non-cacheable memory attributes. The workaround depends on a firmware 768 counterpart. 769 770 KVM guests must also have the workaround implemented or they can 771 deadlock the system. 772 773 Work around the issue by inserting DMB SY barriers around PAR_EL1 774 register reads and warning KVM users. The DMB barrier is sufficient 775 to prevent a speculative PAR_EL1 read. 776 777 If unsure, say Y. 778 779config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 780 bool 781 782config ARM64_ERRATUM_2051678 783 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 784 default y 785 help 786 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 787 Affected Cortex-A510 might not respect the ordering rules for 788 hardware update of the page table's dirty bit. The workaround 789 is to not enable the feature on affected CPUs. 790 791 If unsure, say Y. 792 793config ARM64_ERRATUM_2077057 794 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 795 default y 796 help 797 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 798 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 799 expected, but a Pointer Authentication trap is taken instead. The 800 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 801 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 802 803 This can only happen when EL2 is stepping EL1. 804 805 When these conditions occur, the SPSR_EL2 value is unchanged from the 806 previous guest entry, and can be restored from the in-memory copy. 807 808 If unsure, say Y. 809 810config ARM64_ERRATUM_2658417 811 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 812 default y 813 help 814 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 815 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 816 BFMMLA or VMMLA instructions in rare circumstances when a pair of 817 A510 CPUs are using shared neon hardware. As the sharing is not 818 discoverable by the kernel, hide the BF16 HWCAP to indicate that 819 user-space should not be using these instructions. 820 821 If unsure, say Y. 822 823config ARM64_ERRATUM_2119858 824 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 825 default y 826 depends on CORESIGHT_TRBE 827 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 828 help 829 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 830 831 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 832 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 833 the event of a WRAP event. 834 835 Work around the issue by always making sure we move the TRBPTR_EL1 by 836 256 bytes before enabling the buffer and filling the first 256 bytes of 837 the buffer with ETM ignore packets upon disabling. 838 839 If unsure, say Y. 840 841config ARM64_ERRATUM_2139208 842 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 843 default y 844 depends on CORESIGHT_TRBE 845 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 846 help 847 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 848 849 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 850 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 851 the event of a WRAP event. 852 853 Work around the issue by always making sure we move the TRBPTR_EL1 by 854 256 bytes before enabling the buffer and filling the first 256 bytes of 855 the buffer with ETM ignore packets upon disabling. 856 857 If unsure, say Y. 858 859config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 860 bool 861 862config ARM64_ERRATUM_2054223 863 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 864 default y 865 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 866 help 867 Enable workaround for ARM Cortex-A710 erratum 2054223 868 869 Affected cores may fail to flush the trace data on a TSB instruction, when 870 the PE is in trace prohibited state. This will cause losing a few bytes 871 of the trace cached. 872 873 Workaround is to issue two TSB consecutively on affected cores. 874 875 If unsure, say Y. 876 877config ARM64_ERRATUM_2067961 878 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 879 default y 880 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 881 help 882 Enable workaround for ARM Neoverse-N2 erratum 2067961 883 884 Affected cores may fail to flush the trace data on a TSB instruction, when 885 the PE is in trace prohibited state. This will cause losing a few bytes 886 of the trace cached. 887 888 Workaround is to issue two TSB consecutively on affected cores. 889 890 If unsure, say Y. 891 892config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 893 bool 894 895config ARM64_ERRATUM_2253138 896 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 897 depends on CORESIGHT_TRBE 898 default y 899 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 900 help 901 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 902 903 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 904 for TRBE. Under some conditions, the TRBE might generate a write to the next 905 virtually addressed page following the last page of the TRBE address space 906 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 907 908 Work around this in the driver by always making sure that there is a 909 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 910 911 If unsure, say Y. 912 913config ARM64_ERRATUM_2224489 914 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 915 depends on CORESIGHT_TRBE 916 default y 917 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 918 help 919 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 920 921 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 922 for TRBE. Under some conditions, the TRBE might generate a write to the next 923 virtually addressed page following the last page of the TRBE address space 924 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 925 926 Work around this in the driver by always making sure that there is a 927 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 928 929 If unsure, say Y. 930 931config ARM64_ERRATUM_2441009 932 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 933 default y 934 select ARM64_WORKAROUND_REPEAT_TLBI 935 help 936 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 937 938 Under very rare circumstances, affected Cortex-A510 CPUs 939 may not handle a race between a break-before-make sequence on one 940 CPU, and another CPU accessing the same page. This could allow a 941 store to a page that has been unmapped. 942 943 Work around this by adding the affected CPUs to the list that needs 944 TLB sequences to be done twice. 945 946 If unsure, say Y. 947 948config ARM64_ERRATUM_2064142 949 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 950 depends on CORESIGHT_TRBE 951 default y 952 help 953 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 954 955 Affected Cortex-A510 core might fail to write into system registers after the 956 TRBE has been disabled. Under some conditions after the TRBE has been disabled 957 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 958 and TRBTRG_EL1 will be ignored and will not be effected. 959 960 Work around this in the driver by executing TSB CSYNC and DSB after collection 961 is stopped and before performing a system register write to one of the affected 962 registers. 963 964 If unsure, say Y. 965 966config ARM64_ERRATUM_2038923 967 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 968 depends on CORESIGHT_TRBE 969 default y 970 help 971 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 972 973 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 974 prohibited within the CPU. As a result, the trace buffer or trace buffer state 975 might be corrupted. This happens after TRBE buffer has been enabled by setting 976 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 977 execution changes from a context, in which trace is prohibited to one where it 978 isn't, or vice versa. In these mentioned conditions, the view of whether trace 979 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 980 the trace buffer state might be corrupted. 981 982 Work around this in the driver by preventing an inconsistent view of whether the 983 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 984 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 985 two ISB instructions if no ERET is to take place. 986 987 If unsure, say Y. 988 989config ARM64_ERRATUM_1902691 990 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 991 depends on CORESIGHT_TRBE 992 default y 993 help 994 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 995 996 Affected Cortex-A510 core might cause trace data corruption, when being written 997 into the memory. Effectively TRBE is broken and hence cannot be used to capture 998 trace data. 999 1000 Work around this problem in the driver by just preventing TRBE initialization on 1001 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1002 on such implementations. This will cover the kernel for any firmware that doesn't 1003 do this already. 1004 1005 If unsure, say Y. 1006 1007config ARM64_ERRATUM_2457168 1008 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1009 depends on ARM64_AMU_EXTN 1010 default y 1011 help 1012 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1013 1014 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1015 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1016 incorrectly giving a significantly higher output value. 1017 1018 Work around this problem by returning 0 when reading the affected counter in 1019 key locations that results in disabling all users of this counter. This effect 1020 is the same to firmware disabling affected counters. 1021 1022 If unsure, say Y. 1023 1024config ARM64_ERRATUM_2645198 1025 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1026 default y 1027 help 1028 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1029 1030 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1031 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1032 next instruction abort caused by permission fault. 1033 1034 Only user-space does executable to non-executable permission transition via 1035 mprotect() system call. Workaround the problem by doing a break-before-make 1036 TLB invalidation, for all changes to executable user space mappings. 1037 1038 If unsure, say Y. 1039 1040config ARM64_ERRATUM_2966298 1041 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1042 default y 1043 help 1044 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1045 1046 On an affected Cortex-A520 core, a speculatively executed unprivileged 1047 load might leak data from a privileged level via a cache side channel. 1048 1049 Work around this problem by executing a TLBI before returning to EL0. 1050 1051 If unsure, say Y. 1052 1053config CAVIUM_ERRATUM_22375 1054 bool "Cavium erratum 22375, 24313" 1055 default y 1056 help 1057 Enable workaround for errata 22375 and 24313. 1058 1059 This implements two gicv3-its errata workarounds for ThunderX. Both 1060 with a small impact affecting only ITS table allocation. 1061 1062 erratum 22375: only alloc 8MB table size 1063 erratum 24313: ignore memory access type 1064 1065 The fixes are in ITS initialization and basically ignore memory access 1066 type and table size provided by the TYPER and BASER registers. 1067 1068 If unsure, say Y. 1069 1070config CAVIUM_ERRATUM_23144 1071 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1072 depends on NUMA 1073 default y 1074 help 1075 ITS SYNC command hang for cross node io and collections/cpu mapping. 1076 1077 If unsure, say Y. 1078 1079config CAVIUM_ERRATUM_23154 1080 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1081 default y 1082 help 1083 The ThunderX GICv3 implementation requires a modified version for 1084 reading the IAR status to ensure data synchronization 1085 (access to icc_iar1_el1 is not sync'ed before and after). 1086 1087 It also suffers from erratum 38545 (also present on Marvell's 1088 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1089 spuriously presented to the CPU interface. 1090 1091 If unsure, say Y. 1092 1093config CAVIUM_ERRATUM_27456 1094 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1095 default y 1096 help 1097 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1098 instructions may cause the icache to become corrupted if it 1099 contains data for a non-current ASID. The fix is to 1100 invalidate the icache when changing the mm context. 1101 1102 If unsure, say Y. 1103 1104config CAVIUM_ERRATUM_30115 1105 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1106 default y 1107 help 1108 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1109 1.2, and T83 Pass 1.0, KVM guest execution may disable 1110 interrupts in host. Trapping both GICv3 group-0 and group-1 1111 accesses sidesteps the issue. 1112 1113 If unsure, say Y. 1114 1115config CAVIUM_TX2_ERRATUM_219 1116 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1117 default y 1118 help 1119 On Cavium ThunderX2, a load, store or prefetch instruction between a 1120 TTBR update and the corresponding context synchronizing operation can 1121 cause a spurious Data Abort to be delivered to any hardware thread in 1122 the CPU core. 1123 1124 Work around the issue by avoiding the problematic code sequence and 1125 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1126 trap handler performs the corresponding register access, skips the 1127 instruction and ensures context synchronization by virtue of the 1128 exception return. 1129 1130 If unsure, say Y. 1131 1132config FUJITSU_ERRATUM_010001 1133 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1134 default y 1135 help 1136 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1137 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1138 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1139 This fault occurs under a specific hardware condition when a 1140 load/store instruction performs an address translation using: 1141 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1142 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1143 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1144 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1145 1146 The workaround is to ensure these bits are clear in TCR_ELx. 1147 The workaround only affects the Fujitsu-A64FX. 1148 1149 If unsure, say Y. 1150 1151config HISILICON_ERRATUM_161600802 1152 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1153 default y 1154 help 1155 The HiSilicon Hip07 SoC uses the wrong redistributor base 1156 when issued ITS commands such as VMOVP and VMAPP, and requires 1157 a 128kB offset to be applied to the target address in this commands. 1158 1159 If unsure, say Y. 1160 1161config QCOM_FALKOR_ERRATUM_1003 1162 bool "Falkor E1003: Incorrect translation due to ASID change" 1163 default y 1164 help 1165 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1166 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1167 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1168 then only for entries in the walk cache, since the leaf translation 1169 is unchanged. Work around the erratum by invalidating the walk cache 1170 entries for the trampoline before entering the kernel proper. 1171 1172config QCOM_FALKOR_ERRATUM_1009 1173 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1174 default y 1175 select ARM64_WORKAROUND_REPEAT_TLBI 1176 help 1177 On Falkor v1, the CPU may prematurely complete a DSB following a 1178 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1179 one more time to fix the issue. 1180 1181 If unsure, say Y. 1182 1183config QCOM_QDF2400_ERRATUM_0065 1184 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1185 default y 1186 help 1187 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1188 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1189 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1190 1191 If unsure, say Y. 1192 1193config QCOM_FALKOR_ERRATUM_E1041 1194 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1195 default y 1196 help 1197 Falkor CPU may speculatively fetch instructions from an improper 1198 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1199 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1200 1201 If unsure, say Y. 1202 1203config NVIDIA_CARMEL_CNP_ERRATUM 1204 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1205 default y 1206 help 1207 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1208 invalidate shared TLB entries installed by a different core, as it would 1209 on standard ARM cores. 1210 1211 If unsure, say Y. 1212 1213config ROCKCHIP_ERRATUM_3588001 1214 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1215 default y 1216 help 1217 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1218 This means, that its sharability feature may not be used, even though it 1219 is supported by the IP itself. 1220 1221 If unsure, say Y. 1222 1223config SOCIONEXT_SYNQUACER_PREITS 1224 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1225 default y 1226 help 1227 Socionext Synquacer SoCs implement a separate h/w block to generate 1228 MSI doorbell writes with non-zero values for the device ID. 1229 1230 If unsure, say Y. 1231 1232endmenu # "ARM errata workarounds via the alternatives framework" 1233 1234choice 1235 prompt "Page size" 1236 default ARM64_4K_PAGES 1237 help 1238 Page size (translation granule) configuration. 1239 1240config ARM64_4K_PAGES 1241 bool "4KB" 1242 help 1243 This feature enables 4KB pages support. 1244 1245config ARM64_16K_PAGES 1246 bool "16KB" 1247 help 1248 The system will use 16KB pages support. AArch32 emulation 1249 requires applications compiled with 16K (or a multiple of 16K) 1250 aligned segments. 1251 1252config ARM64_64K_PAGES 1253 bool "64KB" 1254 help 1255 This feature enables 64KB pages support (4KB by default) 1256 allowing only two levels of page tables and faster TLB 1257 look-up. AArch32 emulation requires applications compiled 1258 with 64K aligned segments. 1259 1260endchoice 1261 1262choice 1263 prompt "Virtual address space size" 1264 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1265 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1266 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1267 help 1268 Allows choosing one of multiple possible virtual address 1269 space sizes. The level of translation table is determined by 1270 a combination of page size and virtual address space size. 1271 1272config ARM64_VA_BITS_36 1273 bool "36-bit" if EXPERT 1274 depends on ARM64_16K_PAGES 1275 1276config ARM64_VA_BITS_39 1277 bool "39-bit" 1278 depends on ARM64_4K_PAGES 1279 1280config ARM64_VA_BITS_42 1281 bool "42-bit" 1282 depends on ARM64_64K_PAGES 1283 1284config ARM64_VA_BITS_47 1285 bool "47-bit" 1286 depends on ARM64_16K_PAGES 1287 1288config ARM64_VA_BITS_48 1289 bool "48-bit" 1290 1291config ARM64_VA_BITS_52 1292 bool "52-bit" 1293 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1294 help 1295 Enable 52-bit virtual addressing for userspace when explicitly 1296 requested via a hint to mmap(). The kernel will also use 52-bit 1297 virtual addresses for its own mappings (provided HW support for 1298 this feature is available, otherwise it reverts to 48-bit). 1299 1300 NOTE: Enabling 52-bit virtual addressing in conjunction with 1301 ARMv8.3 Pointer Authentication will result in the PAC being 1302 reduced from 7 bits to 3 bits, which may have a significant 1303 impact on its susceptibility to brute-force attacks. 1304 1305 If unsure, select 48-bit virtual addressing instead. 1306 1307endchoice 1308 1309config ARM64_FORCE_52BIT 1310 bool "Force 52-bit virtual addresses for userspace" 1311 depends on ARM64_VA_BITS_52 && EXPERT 1312 help 1313 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1314 to maintain compatibility with older software by providing 48-bit VAs 1315 unless a hint is supplied to mmap. 1316 1317 This configuration option disables the 48-bit compatibility logic, and 1318 forces all userspace addresses to be 52-bit on HW that supports it. One 1319 should only enable this configuration option for stress testing userspace 1320 memory management code. If unsure say N here. 1321 1322config ARM64_VA_BITS 1323 int 1324 default 36 if ARM64_VA_BITS_36 1325 default 39 if ARM64_VA_BITS_39 1326 default 42 if ARM64_VA_BITS_42 1327 default 47 if ARM64_VA_BITS_47 1328 default 48 if ARM64_VA_BITS_48 1329 default 52 if ARM64_VA_BITS_52 1330 1331choice 1332 prompt "Physical address space size" 1333 default ARM64_PA_BITS_48 1334 help 1335 Choose the maximum physical address range that the kernel will 1336 support. 1337 1338config ARM64_PA_BITS_48 1339 bool "48-bit" 1340 1341config ARM64_PA_BITS_52 1342 bool "52-bit (ARMv8.2)" 1343 depends on ARM64_64K_PAGES 1344 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1345 help 1346 Enable support for a 52-bit physical address space, introduced as 1347 part of the ARMv8.2-LPA extension. 1348 1349 With this enabled, the kernel will also continue to work on CPUs that 1350 do not support ARMv8.2-LPA, but with some added memory overhead (and 1351 minor performance overhead). 1352 1353endchoice 1354 1355config ARM64_PA_BITS 1356 int 1357 default 48 if ARM64_PA_BITS_48 1358 default 52 if ARM64_PA_BITS_52 1359 1360choice 1361 prompt "Endianness" 1362 default CPU_LITTLE_ENDIAN 1363 help 1364 Select the endianness of data accesses performed by the CPU. Userspace 1365 applications will need to be compiled and linked for the endianness 1366 that is selected here. 1367 1368config CPU_BIG_ENDIAN 1369 bool "Build big-endian kernel" 1370 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1371 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1372 depends on AS_IS_GNU || AS_VERSION >= 150000 1373 help 1374 Say Y if you plan on running a kernel with a big-endian userspace. 1375 1376config CPU_LITTLE_ENDIAN 1377 bool "Build little-endian kernel" 1378 help 1379 Say Y if you plan on running a kernel with a little-endian userspace. 1380 This is usually the case for distributions targeting arm64. 1381 1382endchoice 1383 1384config SCHED_MC 1385 bool "Multi-core scheduler support" 1386 help 1387 Multi-core scheduler support improves the CPU scheduler's decision 1388 making when dealing with multi-core CPU chips at a cost of slightly 1389 increased overhead in some places. If unsure say N here. 1390 1391config SCHED_CLUSTER 1392 bool "Cluster scheduler support" 1393 help 1394 Cluster scheduler support improves the CPU scheduler's decision 1395 making when dealing with machines that have clusters of CPUs. 1396 Cluster usually means a couple of CPUs which are placed closely 1397 by sharing mid-level caches, last-level cache tags or internal 1398 busses. 1399 1400config SCHED_SMT 1401 bool "SMT scheduler support" 1402 help 1403 Improves the CPU scheduler's decision making when dealing with 1404 MultiThreading at a cost of slightly increased overhead in some 1405 places. If unsure say N here. 1406 1407config NR_CPUS 1408 int "Maximum number of CPUs (2-4096)" 1409 range 2 4096 1410 default "256" 1411 1412config HOTPLUG_CPU 1413 bool "Support for hot-pluggable CPUs" 1414 select GENERIC_IRQ_MIGRATION 1415 help 1416 Say Y here to experiment with turning CPUs off and on. CPUs 1417 can be controlled through /sys/devices/system/cpu. 1418 1419# Common NUMA Features 1420config NUMA 1421 bool "NUMA Memory Allocation and Scheduler Support" 1422 select GENERIC_ARCH_NUMA 1423 select ACPI_NUMA if ACPI 1424 select OF_NUMA 1425 select HAVE_SETUP_PER_CPU_AREA 1426 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1427 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1428 select USE_PERCPU_NUMA_NODE_ID 1429 help 1430 Enable NUMA (Non-Uniform Memory Access) support. 1431 1432 The kernel will try to allocate memory used by a CPU on the 1433 local memory of the CPU and add some more 1434 NUMA awareness to the kernel. 1435 1436config NODES_SHIFT 1437 int "Maximum NUMA Nodes (as a power of 2)" 1438 range 1 10 1439 default "4" 1440 depends on NUMA 1441 help 1442 Specify the maximum number of NUMA Nodes available on the target 1443 system. Increases memory reserved to accommodate various tables. 1444 1445source "kernel/Kconfig.hz" 1446 1447config ARCH_SPARSEMEM_ENABLE 1448 def_bool y 1449 select SPARSEMEM_VMEMMAP_ENABLE 1450 select SPARSEMEM_VMEMMAP 1451 1452config HW_PERF_EVENTS 1453 def_bool y 1454 depends on ARM_PMU 1455 1456# Supported by clang >= 7.0 or GCC >= 12.0.0 1457config CC_HAVE_SHADOW_CALL_STACK 1458 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1459 1460config PARAVIRT 1461 bool "Enable paravirtualization code" 1462 help 1463 This changes the kernel so it can modify itself when it is run 1464 under a hypervisor, potentially improving performance significantly 1465 over full virtualization. 1466 1467config PARAVIRT_TIME_ACCOUNTING 1468 bool "Paravirtual steal time accounting" 1469 select PARAVIRT 1470 help 1471 Select this option to enable fine granularity task steal time 1472 accounting. Time spent executing other tasks in parallel with 1473 the current vCPU is discounted from the vCPU power. To account for 1474 that, there can be a small performance impact. 1475 1476 If in doubt, say N here. 1477 1478config ARCH_SUPPORTS_KEXEC 1479 def_bool PM_SLEEP_SMP 1480 1481config ARCH_SUPPORTS_KEXEC_FILE 1482 def_bool y 1483 1484config ARCH_SELECTS_KEXEC_FILE 1485 def_bool y 1486 depends on KEXEC_FILE 1487 select HAVE_IMA_KEXEC if IMA 1488 1489config ARCH_SUPPORTS_KEXEC_SIG 1490 def_bool y 1491 1492config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1493 def_bool y 1494 1495config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1496 def_bool y 1497 1498config ARCH_SUPPORTS_CRASH_DUMP 1499 def_bool y 1500 1501config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1502 def_bool CRASH_CORE 1503 1504config TRANS_TABLE 1505 def_bool y 1506 depends on HIBERNATION || KEXEC_CORE 1507 1508config XEN_DOM0 1509 def_bool y 1510 depends on XEN 1511 1512config XEN 1513 bool "Xen guest support on ARM64" 1514 depends on ARM64 && OF 1515 select SWIOTLB_XEN 1516 select PARAVIRT 1517 help 1518 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1519 1520# include/linux/mmzone.h requires the following to be true: 1521# 1522# MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1523# 1524# so the maximum value of MAX_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1525# 1526# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_ORDER | default MAX_ORDER | 1527# ----+-------------------+--------------+-----------------+--------------------+ 1528# 4K | 27 | 12 | 15 | 10 | 1529# 16K | 27 | 14 | 13 | 11 | 1530# 64K | 29 | 16 | 13 | 13 | 1531config ARCH_FORCE_MAX_ORDER 1532 int 1533 default "13" if ARM64_64K_PAGES 1534 default "11" if ARM64_16K_PAGES 1535 default "10" 1536 help 1537 The kernel page allocator limits the size of maximal physically 1538 contiguous allocations. The limit is called MAX_ORDER and it 1539 defines the maximal power of two of number of pages that can be 1540 allocated as a single contiguous block. This option allows 1541 overriding the default setting when ability to allocate very 1542 large blocks of physically contiguous memory is required. 1543 1544 The maximal size of allocation cannot exceed the size of the 1545 section, so the value of MAX_ORDER should satisfy 1546 1547 MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1548 1549 Don't change if unsure. 1550 1551config UNMAP_KERNEL_AT_EL0 1552 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1553 default y 1554 help 1555 Speculation attacks against some high-performance processors can 1556 be used to bypass MMU permission checks and leak kernel data to 1557 userspace. This can be defended against by unmapping the kernel 1558 when running in userspace, mapping it back in on exception entry 1559 via a trampoline page in the vector table. 1560 1561 If unsure, say Y. 1562 1563config MITIGATE_SPECTRE_BRANCH_HISTORY 1564 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1565 default y 1566 help 1567 Speculation attacks against some high-performance processors can 1568 make use of branch history to influence future speculation. 1569 When taking an exception from user-space, a sequence of branches 1570 or a firmware call overwrites the branch history. 1571 1572config RODATA_FULL_DEFAULT_ENABLED 1573 bool "Apply r/o permissions of VM areas also to their linear aliases" 1574 default y 1575 help 1576 Apply read-only attributes of VM areas to the linear alias of 1577 the backing pages as well. This prevents code or read-only data 1578 from being modified (inadvertently or intentionally) via another 1579 mapping of the same memory page. This additional enhancement can 1580 be turned off at runtime by passing rodata=[off|on] (and turned on 1581 with rodata=full if this option is set to 'n') 1582 1583 This requires the linear region to be mapped down to pages, 1584 which may adversely affect performance in some cases. 1585 1586config ARM64_SW_TTBR0_PAN 1587 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1588 help 1589 Enabling this option prevents the kernel from accessing 1590 user-space memory directly by pointing TTBR0_EL1 to a reserved 1591 zeroed area and reserved ASID. The user access routines 1592 restore the valid TTBR0_EL1 temporarily. 1593 1594config ARM64_TAGGED_ADDR_ABI 1595 bool "Enable the tagged user addresses syscall ABI" 1596 default y 1597 help 1598 When this option is enabled, user applications can opt in to a 1599 relaxed ABI via prctl() allowing tagged addresses to be passed 1600 to system calls as pointer arguments. For details, see 1601 Documentation/arch/arm64/tagged-address-abi.rst. 1602 1603menuconfig COMPAT 1604 bool "Kernel support for 32-bit EL0" 1605 depends on ARM64_4K_PAGES || EXPERT 1606 select HAVE_UID16 1607 select OLD_SIGSUSPEND3 1608 select COMPAT_OLD_SIGACTION 1609 help 1610 This option enables support for a 32-bit EL0 running under a 64-bit 1611 kernel at EL1. AArch32-specific components such as system calls, 1612 the user helper functions, VFP support and the ptrace interface are 1613 handled appropriately by the kernel. 1614 1615 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1616 that you will only be able to execute AArch32 binaries that were compiled 1617 with page size aligned segments. 1618 1619 If you want to execute 32-bit userspace applications, say Y. 1620 1621if COMPAT 1622 1623config KUSER_HELPERS 1624 bool "Enable kuser helpers page for 32-bit applications" 1625 default y 1626 help 1627 Warning: disabling this option may break 32-bit user programs. 1628 1629 Provide kuser helpers to compat tasks. The kernel provides 1630 helper code to userspace in read only form at a fixed location 1631 to allow userspace to be independent of the CPU type fitted to 1632 the system. This permits binaries to be run on ARMv4 through 1633 to ARMv8 without modification. 1634 1635 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1636 1637 However, the fixed address nature of these helpers can be used 1638 by ROP (return orientated programming) authors when creating 1639 exploits. 1640 1641 If all of the binaries and libraries which run on your platform 1642 are built specifically for your platform, and make no use of 1643 these helpers, then you can turn this option off to hinder 1644 such exploits. However, in that case, if a binary or library 1645 relying on those helpers is run, it will not function correctly. 1646 1647 Say N here only if you are absolutely certain that you do not 1648 need these helpers; otherwise, the safe option is to say Y. 1649 1650config COMPAT_VDSO 1651 bool "Enable vDSO for 32-bit applications" 1652 depends on !CPU_BIG_ENDIAN 1653 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1654 select GENERIC_COMPAT_VDSO 1655 default y 1656 help 1657 Place in the process address space of 32-bit applications an 1658 ELF shared object providing fast implementations of gettimeofday 1659 and clock_gettime. 1660 1661 You must have a 32-bit build of glibc 2.22 or later for programs 1662 to seamlessly take advantage of this. 1663 1664config THUMB2_COMPAT_VDSO 1665 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1666 depends on COMPAT_VDSO 1667 default y 1668 help 1669 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1670 otherwise with '-marm'. 1671 1672config COMPAT_ALIGNMENT_FIXUPS 1673 bool "Fix up misaligned multi-word loads and stores in user space" 1674 1675menuconfig ARMV8_DEPRECATED 1676 bool "Emulate deprecated/obsolete ARMv8 instructions" 1677 depends on SYSCTL 1678 help 1679 Legacy software support may require certain instructions 1680 that have been deprecated or obsoleted in the architecture. 1681 1682 Enable this config to enable selective emulation of these 1683 features. 1684 1685 If unsure, say Y 1686 1687if ARMV8_DEPRECATED 1688 1689config SWP_EMULATION 1690 bool "Emulate SWP/SWPB instructions" 1691 help 1692 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1693 they are always undefined. Say Y here to enable software 1694 emulation of these instructions for userspace using LDXR/STXR. 1695 This feature can be controlled at runtime with the abi.swp 1696 sysctl which is disabled by default. 1697 1698 In some older versions of glibc [<=2.8] SWP is used during futex 1699 trylock() operations with the assumption that the code will not 1700 be preempted. This invalid assumption may be more likely to fail 1701 with SWP emulation enabled, leading to deadlock of the user 1702 application. 1703 1704 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1705 on an external transaction monitoring block called a global 1706 monitor to maintain update atomicity. If your system does not 1707 implement a global monitor, this option can cause programs that 1708 perform SWP operations to uncached memory to deadlock. 1709 1710 If unsure, say Y 1711 1712config CP15_BARRIER_EMULATION 1713 bool "Emulate CP15 Barrier instructions" 1714 help 1715 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1716 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1717 strongly recommended to use the ISB, DSB, and DMB 1718 instructions instead. 1719 1720 Say Y here to enable software emulation of these 1721 instructions for AArch32 userspace code. When this option is 1722 enabled, CP15 barrier usage is traced which can help 1723 identify software that needs updating. This feature can be 1724 controlled at runtime with the abi.cp15_barrier sysctl. 1725 1726 If unsure, say Y 1727 1728config SETEND_EMULATION 1729 bool "Emulate SETEND instruction" 1730 help 1731 The SETEND instruction alters the data-endianness of the 1732 AArch32 EL0, and is deprecated in ARMv8. 1733 1734 Say Y here to enable software emulation of the instruction 1735 for AArch32 userspace code. This feature can be controlled 1736 at runtime with the abi.setend sysctl. 1737 1738 Note: All the cpus on the system must have mixed endian support at EL0 1739 for this feature to be enabled. If a new CPU - which doesn't support mixed 1740 endian - is hotplugged in after this feature has been enabled, there could 1741 be unexpected results in the applications. 1742 1743 If unsure, say Y 1744endif # ARMV8_DEPRECATED 1745 1746endif # COMPAT 1747 1748menu "ARMv8.1 architectural features" 1749 1750config ARM64_HW_AFDBM 1751 bool "Support for hardware updates of the Access and Dirty page flags" 1752 default y 1753 help 1754 The ARMv8.1 architecture extensions introduce support for 1755 hardware updates of the access and dirty information in page 1756 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1757 capable processors, accesses to pages with PTE_AF cleared will 1758 set this bit instead of raising an access flag fault. 1759 Similarly, writes to read-only pages with the DBM bit set will 1760 clear the read-only bit (AP[2]) instead of raising a 1761 permission fault. 1762 1763 Kernels built with this configuration option enabled continue 1764 to work on pre-ARMv8.1 hardware and the performance impact is 1765 minimal. If unsure, say Y. 1766 1767config ARM64_PAN 1768 bool "Enable support for Privileged Access Never (PAN)" 1769 default y 1770 help 1771 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1772 prevents the kernel or hypervisor from accessing user-space (EL0) 1773 memory directly. 1774 1775 Choosing this option will cause any unprotected (not using 1776 copy_to_user et al) memory access to fail with a permission fault. 1777 1778 The feature is detected at runtime, and will remain as a 'nop' 1779 instruction if the cpu does not implement the feature. 1780 1781config AS_HAS_LSE_ATOMICS 1782 def_bool $(as-instr,.arch_extension lse) 1783 1784config ARM64_LSE_ATOMICS 1785 bool 1786 default ARM64_USE_LSE_ATOMICS 1787 depends on AS_HAS_LSE_ATOMICS 1788 1789config ARM64_USE_LSE_ATOMICS 1790 bool "Atomic instructions" 1791 default y 1792 help 1793 As part of the Large System Extensions, ARMv8.1 introduces new 1794 atomic instructions that are designed specifically to scale in 1795 very large systems. 1796 1797 Say Y here to make use of these instructions for the in-kernel 1798 atomic routines. This incurs a small overhead on CPUs that do 1799 not support these instructions and requires the kernel to be 1800 built with binutils >= 2.25 in order for the new instructions 1801 to be used. 1802 1803endmenu # "ARMv8.1 architectural features" 1804 1805menu "ARMv8.2 architectural features" 1806 1807config AS_HAS_ARMV8_2 1808 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1809 1810config AS_HAS_SHA3 1811 def_bool $(as-instr,.arch armv8.2-a+sha3) 1812 1813config ARM64_PMEM 1814 bool "Enable support for persistent memory" 1815 select ARCH_HAS_PMEM_API 1816 select ARCH_HAS_UACCESS_FLUSHCACHE 1817 help 1818 Say Y to enable support for the persistent memory API based on the 1819 ARMv8.2 DCPoP feature. 1820 1821 The feature is detected at runtime, and the kernel will use DC CVAC 1822 operations if DC CVAP is not supported (following the behaviour of 1823 DC CVAP itself if the system does not define a point of persistence). 1824 1825config ARM64_RAS_EXTN 1826 bool "Enable support for RAS CPU Extensions" 1827 default y 1828 help 1829 CPUs that support the Reliability, Availability and Serviceability 1830 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1831 errors, classify them and report them to software. 1832 1833 On CPUs with these extensions system software can use additional 1834 barriers to determine if faults are pending and read the 1835 classification from a new set of registers. 1836 1837 Selecting this feature will allow the kernel to use these barriers 1838 and access the new registers if the system supports the extension. 1839 Platform RAS features may additionally depend on firmware support. 1840 1841config ARM64_CNP 1842 bool "Enable support for Common Not Private (CNP) translations" 1843 default y 1844 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1845 help 1846 Common Not Private (CNP) allows translation table entries to 1847 be shared between different PEs in the same inner shareable 1848 domain, so the hardware can use this fact to optimise the 1849 caching of such entries in the TLB. 1850 1851 Selecting this option allows the CNP feature to be detected 1852 at runtime, and does not affect PEs that do not implement 1853 this feature. 1854 1855endmenu # "ARMv8.2 architectural features" 1856 1857menu "ARMv8.3 architectural features" 1858 1859config ARM64_PTR_AUTH 1860 bool "Enable support for pointer authentication" 1861 default y 1862 help 1863 Pointer authentication (part of the ARMv8.3 Extensions) provides 1864 instructions for signing and authenticating pointers against secret 1865 keys, which can be used to mitigate Return Oriented Programming (ROP) 1866 and other attacks. 1867 1868 This option enables these instructions at EL0 (i.e. for userspace). 1869 Choosing this option will cause the kernel to initialise secret keys 1870 for each process at exec() time, with these keys being 1871 context-switched along with the process. 1872 1873 The feature is detected at runtime. If the feature is not present in 1874 hardware it will not be advertised to userspace/KVM guest nor will it 1875 be enabled. 1876 1877 If the feature is present on the boot CPU but not on a late CPU, then 1878 the late CPU will be parked. Also, if the boot CPU does not have 1879 address auth and the late CPU has then the late CPU will still boot 1880 but with the feature disabled. On such a system, this option should 1881 not be selected. 1882 1883config ARM64_PTR_AUTH_KERNEL 1884 bool "Use pointer authentication for kernel" 1885 default y 1886 depends on ARM64_PTR_AUTH 1887 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1888 # Modern compilers insert a .note.gnu.property section note for PAC 1889 # which is only understood by binutils starting with version 2.33.1. 1890 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1891 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1892 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1893 help 1894 If the compiler supports the -mbranch-protection or 1895 -msign-return-address flag (e.g. GCC 7 or later), then this option 1896 will cause the kernel itself to be compiled with return address 1897 protection. In this case, and if the target hardware is known to 1898 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1899 disabled with minimal loss of protection. 1900 1901 This feature works with FUNCTION_GRAPH_TRACER option only if 1902 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1903 1904config CC_HAS_BRANCH_PROT_PAC_RET 1905 # GCC 9 or later, clang 8 or later 1906 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1907 1908config CC_HAS_SIGN_RETURN_ADDRESS 1909 # GCC 7, 8 1910 def_bool $(cc-option,-msign-return-address=all) 1911 1912config AS_HAS_ARMV8_3 1913 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1914 1915config AS_HAS_CFI_NEGATE_RA_STATE 1916 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1917 1918config AS_HAS_LDAPR 1919 def_bool $(as-instr,.arch_extension rcpc) 1920 1921endmenu # "ARMv8.3 architectural features" 1922 1923menu "ARMv8.4 architectural features" 1924 1925config ARM64_AMU_EXTN 1926 bool "Enable support for the Activity Monitors Unit CPU extension" 1927 default y 1928 help 1929 The activity monitors extension is an optional extension introduced 1930 by the ARMv8.4 CPU architecture. This enables support for version 1 1931 of the activity monitors architecture, AMUv1. 1932 1933 To enable the use of this extension on CPUs that implement it, say Y. 1934 1935 Note that for architectural reasons, firmware _must_ implement AMU 1936 support when running on CPUs that present the activity monitors 1937 extension. The required support is present in: 1938 * Version 1.5 and later of the ARM Trusted Firmware 1939 1940 For kernels that have this configuration enabled but boot with broken 1941 firmware, you may need to say N here until the firmware is fixed. 1942 Otherwise you may experience firmware panics or lockups when 1943 accessing the counter registers. Even if you are not observing these 1944 symptoms, the values returned by the register reads might not 1945 correctly reflect reality. Most commonly, the value read will be 0, 1946 indicating that the counter is not enabled. 1947 1948config AS_HAS_ARMV8_4 1949 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1950 1951config ARM64_TLB_RANGE 1952 bool "Enable support for tlbi range feature" 1953 default y 1954 depends on AS_HAS_ARMV8_4 1955 help 1956 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1957 range of input addresses. 1958 1959 The feature introduces new assembly instructions, and they were 1960 support when binutils >= 2.30. 1961 1962endmenu # "ARMv8.4 architectural features" 1963 1964menu "ARMv8.5 architectural features" 1965 1966config AS_HAS_ARMV8_5 1967 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1968 1969config ARM64_BTI 1970 bool "Branch Target Identification support" 1971 default y 1972 help 1973 Branch Target Identification (part of the ARMv8.5 Extensions) 1974 provides a mechanism to limit the set of locations to which computed 1975 branch instructions such as BR or BLR can jump. 1976 1977 To make use of BTI on CPUs that support it, say Y. 1978 1979 BTI is intended to provide complementary protection to other control 1980 flow integrity protection mechanisms, such as the Pointer 1981 authentication mechanism provided as part of the ARMv8.3 Extensions. 1982 For this reason, it does not make sense to enable this option without 1983 also enabling support for pointer authentication. Thus, when 1984 enabling this option you should also select ARM64_PTR_AUTH=y. 1985 1986 Userspace binaries must also be specifically compiled to make use of 1987 this mechanism. If you say N here or the hardware does not support 1988 BTI, such binaries can still run, but you get no additional 1989 enforcement of branch destinations. 1990 1991config ARM64_BTI_KERNEL 1992 bool "Use Branch Target Identification for kernel" 1993 default y 1994 depends on ARM64_BTI 1995 depends on ARM64_PTR_AUTH_KERNEL 1996 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1997 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1998 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1999 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2000 depends on !CC_IS_GCC 2001 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 2002 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 2003 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2004 help 2005 Build the kernel with Branch Target Identification annotations 2006 and enable enforcement of this for kernel code. When this option 2007 is enabled and the system supports BTI all kernel code including 2008 modular code must have BTI enabled. 2009 2010config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2011 # GCC 9 or later, clang 8 or later 2012 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2013 2014config ARM64_E0PD 2015 bool "Enable support for E0PD" 2016 default y 2017 help 2018 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2019 that EL0 accesses made via TTBR1 always fault in constant time, 2020 providing similar benefits to KASLR as those provided by KPTI, but 2021 with lower overhead and without disrupting legitimate access to 2022 kernel memory such as SPE. 2023 2024 This option enables E0PD for TTBR1 where available. 2025 2026config ARM64_AS_HAS_MTE 2027 # Initial support for MTE went in binutils 2.32.0, checked with 2028 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2029 # as a late addition to the final architecture spec (LDGM/STGM) 2030 # is only supported in the newer 2.32.x and 2.33 binutils 2031 # versions, hence the extra "stgm" instruction check below. 2032 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2033 2034config ARM64_MTE 2035 bool "Memory Tagging Extension support" 2036 default y 2037 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2038 depends on AS_HAS_ARMV8_5 2039 depends on AS_HAS_LSE_ATOMICS 2040 # Required for tag checking in the uaccess routines 2041 depends on ARM64_PAN 2042 select ARCH_HAS_SUBPAGE_FAULTS 2043 select ARCH_USES_HIGH_VMA_FLAGS 2044 select ARCH_USES_PG_ARCH_X 2045 help 2046 Memory Tagging (part of the ARMv8.5 Extensions) provides 2047 architectural support for run-time, always-on detection of 2048 various classes of memory error to aid with software debugging 2049 to eliminate vulnerabilities arising from memory-unsafe 2050 languages. 2051 2052 This option enables the support for the Memory Tagging 2053 Extension at EL0 (i.e. for userspace). 2054 2055 Selecting this option allows the feature to be detected at 2056 runtime. Any secondary CPU not implementing this feature will 2057 not be allowed a late bring-up. 2058 2059 Userspace binaries that want to use this feature must 2060 explicitly opt in. The mechanism for the userspace is 2061 described in: 2062 2063 Documentation/arch/arm64/memory-tagging-extension.rst. 2064 2065endmenu # "ARMv8.5 architectural features" 2066 2067menu "ARMv8.7 architectural features" 2068 2069config ARM64_EPAN 2070 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2071 default y 2072 depends on ARM64_PAN 2073 help 2074 Enhanced Privileged Access Never (EPAN) allows Privileged 2075 Access Never to be used with Execute-only mappings. 2076 2077 The feature is detected at runtime, and will remain disabled 2078 if the cpu does not implement the feature. 2079endmenu # "ARMv8.7 architectural features" 2080 2081config ARM64_SVE 2082 bool "ARM Scalable Vector Extension support" 2083 default y 2084 help 2085 The Scalable Vector Extension (SVE) is an extension to the AArch64 2086 execution state which complements and extends the SIMD functionality 2087 of the base architecture to support much larger vectors and to enable 2088 additional vectorisation opportunities. 2089 2090 To enable use of this extension on CPUs that implement it, say Y. 2091 2092 On CPUs that support the SVE2 extensions, this option will enable 2093 those too. 2094 2095 Note that for architectural reasons, firmware _must_ implement SVE 2096 support when running on SVE capable hardware. The required support 2097 is present in: 2098 2099 * version 1.5 and later of the ARM Trusted Firmware 2100 * the AArch64 boot wrapper since commit 5e1261e08abf 2101 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2102 2103 For other firmware implementations, consult the firmware documentation 2104 or vendor. 2105 2106 If you need the kernel to boot on SVE-capable hardware with broken 2107 firmware, you may need to say N here until you get your firmware 2108 fixed. Otherwise, you may experience firmware panics or lockups when 2109 booting the kernel. If unsure and you are not observing these 2110 symptoms, you should assume that it is safe to say Y. 2111 2112config ARM64_SME 2113 bool "ARM Scalable Matrix Extension support" 2114 default y 2115 depends on ARM64_SVE 2116 help 2117 The Scalable Matrix Extension (SME) is an extension to the AArch64 2118 execution state which utilises a substantial subset of the SVE 2119 instruction set, together with the addition of new architectural 2120 register state capable of holding two dimensional matrix tiles to 2121 enable various matrix operations. 2122 2123config ARM64_PSEUDO_NMI 2124 bool "Support for NMI-like interrupts" 2125 select ARM_GIC_V3 2126 help 2127 Adds support for mimicking Non-Maskable Interrupts through the use of 2128 GIC interrupt priority. This support requires version 3 or later of 2129 ARM GIC. 2130 2131 This high priority configuration for interrupts needs to be 2132 explicitly enabled by setting the kernel parameter 2133 "irqchip.gicv3_pseudo_nmi" to 1. 2134 2135 If unsure, say N 2136 2137if ARM64_PSEUDO_NMI 2138config ARM64_DEBUG_PRIORITY_MASKING 2139 bool "Debug interrupt priority masking" 2140 help 2141 This adds runtime checks to functions enabling/disabling 2142 interrupts when using priority masking. The additional checks verify 2143 the validity of ICC_PMR_EL1 when calling concerned functions. 2144 2145 If unsure, say N 2146endif # ARM64_PSEUDO_NMI 2147 2148config RELOCATABLE 2149 bool "Build a relocatable kernel image" if EXPERT 2150 select ARCH_HAS_RELR 2151 default y 2152 help 2153 This builds the kernel as a Position Independent Executable (PIE), 2154 which retains all relocation metadata required to relocate the 2155 kernel binary at runtime to a different virtual address than the 2156 address it was linked at. 2157 Since AArch64 uses the RELA relocation format, this requires a 2158 relocation pass at runtime even if the kernel is loaded at the 2159 same address it was linked at. 2160 2161config RANDOMIZE_BASE 2162 bool "Randomize the address of the kernel image" 2163 select RELOCATABLE 2164 help 2165 Randomizes the virtual address at which the kernel image is 2166 loaded, as a security feature that deters exploit attempts 2167 relying on knowledge of the location of kernel internals. 2168 2169 It is the bootloader's job to provide entropy, by passing a 2170 random u64 value in /chosen/kaslr-seed at kernel entry. 2171 2172 When booting via the UEFI stub, it will invoke the firmware's 2173 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2174 to the kernel proper. In addition, it will randomise the physical 2175 location of the kernel Image as well. 2176 2177 If unsure, say N. 2178 2179config RANDOMIZE_MODULE_REGION_FULL 2180 bool "Randomize the module region over a 2 GB range" 2181 depends on RANDOMIZE_BASE 2182 default y 2183 help 2184 Randomizes the location of the module region inside a 2 GB window 2185 covering the core kernel. This way, it is less likely for modules 2186 to leak information about the location of core kernel data structures 2187 but it does imply that function calls between modules and the core 2188 kernel will need to be resolved via veneers in the module PLT. 2189 2190 When this option is not set, the module region will be randomized over 2191 a limited range that contains the [_stext, _etext] interval of the 2192 core kernel, so branch relocations are almost always in range unless 2193 the region is exhausted. In this particular case of region 2194 exhaustion, modules might be able to fall back to a larger 2GB area. 2195 2196config CC_HAVE_STACKPROTECTOR_SYSREG 2197 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2198 2199config STACKPROTECTOR_PER_TASK 2200 def_bool y 2201 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2202 2203config UNWIND_PATCH_PAC_INTO_SCS 2204 bool "Enable shadow call stack dynamically using code patching" 2205 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2206 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2207 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2208 depends on SHADOW_CALL_STACK 2209 select UNWIND_TABLES 2210 select DYNAMIC_SCS 2211 2212endmenu # "Kernel Features" 2213 2214menu "Boot options" 2215 2216config ARM64_ACPI_PARKING_PROTOCOL 2217 bool "Enable support for the ARM64 ACPI parking protocol" 2218 depends on ACPI 2219 help 2220 Enable support for the ARM64 ACPI parking protocol. If disabled 2221 the kernel will not allow booting through the ARM64 ACPI parking 2222 protocol even if the corresponding data is present in the ACPI 2223 MADT table. 2224 2225config CMDLINE 2226 string "Default kernel command string" 2227 default "" 2228 help 2229 Provide a set of default command-line options at build time by 2230 entering them here. As a minimum, you should specify the the 2231 root device (e.g. root=/dev/nfs). 2232 2233choice 2234 prompt "Kernel command line type" if CMDLINE != "" 2235 default CMDLINE_FROM_BOOTLOADER 2236 help 2237 Choose how the kernel will handle the provided default kernel 2238 command line string. 2239 2240config CMDLINE_FROM_BOOTLOADER 2241 bool "Use bootloader kernel arguments if available" 2242 help 2243 Uses the command-line options passed by the boot loader. If 2244 the boot loader doesn't provide any, the default kernel command 2245 string provided in CMDLINE will be used. 2246 2247config CMDLINE_FORCE 2248 bool "Always use the default kernel command string" 2249 help 2250 Always use the default kernel command string, even if the boot 2251 loader passes other arguments to the kernel. 2252 This is useful if you cannot or don't want to change the 2253 command-line options your boot loader passes to the kernel. 2254 2255endchoice 2256 2257config EFI_STUB 2258 bool 2259 2260config EFI 2261 bool "UEFI runtime support" 2262 depends on OF && !CPU_BIG_ENDIAN 2263 depends on KERNEL_MODE_NEON 2264 select ARCH_SUPPORTS_ACPI 2265 select LIBFDT 2266 select UCS2_STRING 2267 select EFI_PARAMS_FROM_FDT 2268 select EFI_RUNTIME_WRAPPERS 2269 select EFI_STUB 2270 select EFI_GENERIC_STUB 2271 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2272 default y 2273 help 2274 This option provides support for runtime services provided 2275 by UEFI firmware (such as non-volatile variables, realtime 2276 clock, and platform reset). A UEFI stub is also provided to 2277 allow the kernel to be booted as an EFI application. This 2278 is only useful on systems that have UEFI firmware. 2279 2280config DMI 2281 bool "Enable support for SMBIOS (DMI) tables" 2282 depends on EFI 2283 default y 2284 help 2285 This enables SMBIOS/DMI feature for systems. 2286 2287 This option is only useful on systems that have UEFI firmware. 2288 However, even with this option, the resultant kernel should 2289 continue to boot on existing non-UEFI platforms. 2290 2291endmenu # "Boot options" 2292 2293menu "Power management options" 2294 2295source "kernel/power/Kconfig" 2296 2297config ARCH_HIBERNATION_POSSIBLE 2298 def_bool y 2299 depends on CPU_PM 2300 2301config ARCH_HIBERNATION_HEADER 2302 def_bool y 2303 depends on HIBERNATION 2304 2305config ARCH_SUSPEND_POSSIBLE 2306 def_bool y 2307 2308endmenu # "Power management options" 2309 2310menu "CPU Power Management" 2311 2312source "drivers/cpuidle/Kconfig" 2313 2314source "drivers/cpufreq/Kconfig" 2315 2316endmenu # "CPU Power Management" 2317 2318source "drivers/acpi/Kconfig" 2319 2320source "arch/arm64/kvm/Kconfig" 2321 2322