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_HW_PTE_YOUNG 40 select ARCH_HAS_SETUP_DMA_OPS 41 select ARCH_HAS_SET_DIRECT_MAP 42 select ARCH_HAS_SET_MEMORY 43 select ARCH_STACKWALK 44 select ARCH_HAS_STRICT_KERNEL_RWX 45 select ARCH_HAS_STRICT_MODULE_RWX 46 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 47 select ARCH_HAS_SYNC_DMA_FOR_CPU 48 select ARCH_HAS_SYSCALL_WRAPPER 49 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 50 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 51 select ARCH_HAS_ZONE_DMA_SET if EXPERT 52 select ARCH_HAVE_ELF_PROT 53 select ARCH_HAVE_NMI_SAFE_CMPXCHG 54 select ARCH_HAVE_TRACE_MMIO_ACCESS 55 select ARCH_INLINE_READ_LOCK if !PREEMPTION 56 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 57 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 58 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 59 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 60 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 61 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 62 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 63 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 64 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 65 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 66 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 67 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 68 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 69 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 70 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 71 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 72 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 73 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 74 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 75 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 76 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 77 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 78 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 79 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 80 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 81 select ARCH_KEEP_MEMBLOCK 82 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 83 select ARCH_USE_CMPXCHG_LOCKREF 84 select ARCH_USE_GNU_PROPERTY 85 select ARCH_USE_MEMTEST 86 select ARCH_USE_QUEUED_RWLOCKS 87 select ARCH_USE_QUEUED_SPINLOCKS 88 select ARCH_USE_SYM_ANNOTATIONS 89 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 90 select ARCH_SUPPORTS_HUGETLBFS 91 select ARCH_SUPPORTS_MEMORY_FAILURE 92 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 93 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 94 select ARCH_SUPPORTS_LTO_CLANG_THIN 95 select ARCH_SUPPORTS_CFI_CLANG 96 select ARCH_SUPPORTS_ATOMIC_RMW 97 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 98 select ARCH_SUPPORTS_NUMA_BALANCING 99 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 100 select ARCH_SUPPORTS_PER_VMA_LOCK 101 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 102 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 103 select ARCH_WANT_DEFAULT_BPF_JIT 104 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 105 select ARCH_WANT_FRAME_POINTERS 106 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 107 select ARCH_WANT_LD_ORPHAN_WARN 108 select ARCH_WANTS_NO_INSTR 109 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 110 select ARCH_HAS_UBSAN_SANITIZE_ALL 111 select ARM_AMBA 112 select ARM_ARCH_TIMER 113 select ARM_GIC 114 select AUDIT_ARCH_COMPAT_GENERIC 115 select ARM_GIC_V2M if PCI 116 select ARM_GIC_V3 117 select ARM_GIC_V3_ITS if PCI 118 select ARM_PSCI_FW 119 select BUILDTIME_TABLE_SORT 120 select CLONE_BACKWARDS 121 select COMMON_CLK 122 select CPU_PM if (SUSPEND || CPU_IDLE) 123 select CRC32 124 select DCACHE_WORD_ACCESS 125 select DYNAMIC_FTRACE if FUNCTION_TRACER 126 select DMA_BOUNCE_UNALIGNED_KMALLOC 127 select DMA_DIRECT_REMAP 128 select EDAC_SUPPORT 129 select FRAME_POINTER 130 select FUNCTION_ALIGNMENT_4B 131 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 132 select GENERIC_ALLOCATOR 133 select GENERIC_ARCH_TOPOLOGY 134 select GENERIC_CLOCKEVENTS_BROADCAST 135 select GENERIC_CPU_AUTOPROBE 136 select GENERIC_CPU_VULNERABILITIES 137 select GENERIC_EARLY_IOREMAP 138 select GENERIC_IDLE_POLL_SETUP 139 select GENERIC_IOREMAP 140 select GENERIC_IRQ_IPI 141 select GENERIC_IRQ_PROBE 142 select GENERIC_IRQ_SHOW 143 select GENERIC_IRQ_SHOW_LEVEL 144 select GENERIC_LIB_DEVMEM_IS_ALLOWED 145 select GENERIC_PCI_IOMAP 146 select GENERIC_PTDUMP 147 select GENERIC_SCHED_CLOCK 148 select GENERIC_SMP_IDLE_THREAD 149 select GENERIC_TIME_VSYSCALL 150 select GENERIC_GETTIMEOFDAY 151 select GENERIC_VDSO_TIME_NS 152 select HARDIRQS_SW_RESEND 153 select HAS_IOPORT 154 select HAVE_MOVE_PMD 155 select HAVE_MOVE_PUD 156 select HAVE_PCI 157 select HAVE_ACPI_APEI if (ACPI && EFI) 158 select HAVE_ALIGNED_STRUCT_PAGE 159 select HAVE_ARCH_AUDITSYSCALL 160 select HAVE_ARCH_BITREVERSE 161 select HAVE_ARCH_COMPILER_H 162 select HAVE_ARCH_HUGE_VMALLOC 163 select HAVE_ARCH_HUGE_VMAP 164 select HAVE_ARCH_JUMP_LABEL 165 select HAVE_ARCH_JUMP_LABEL_RELATIVE 166 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 167 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 168 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 169 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 170 # Some instrumentation may be unsound, hence EXPERT 171 select HAVE_ARCH_KCSAN if EXPERT 172 select HAVE_ARCH_KFENCE 173 select HAVE_ARCH_KGDB 174 select HAVE_ARCH_MMAP_RND_BITS 175 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 176 select HAVE_ARCH_PREL32_RELOCATIONS 177 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 178 select HAVE_ARCH_SECCOMP_FILTER 179 select HAVE_ARCH_STACKLEAK 180 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 181 select HAVE_ARCH_TRACEHOOK 182 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 183 select HAVE_ARCH_VMAP_STACK 184 select HAVE_ARM_SMCCC 185 select HAVE_ASM_MODVERSIONS 186 select HAVE_EBPF_JIT 187 select HAVE_C_RECORDMCOUNT 188 select HAVE_CMPXCHG_DOUBLE 189 select HAVE_CMPXCHG_LOCAL 190 select HAVE_CONTEXT_TRACKING_USER 191 select HAVE_DEBUG_KMEMLEAK 192 select HAVE_DMA_CONTIGUOUS 193 select HAVE_DYNAMIC_FTRACE 194 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 195 if $(cc-option,-fpatchable-function-entry=2) 196 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 197 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 198 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 199 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 200 !CC_OPTIMIZE_FOR_SIZE) 201 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 202 if DYNAMIC_FTRACE_WITH_ARGS 203 select HAVE_SAMPLE_FTRACE_DIRECT 204 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 205 select HAVE_EFFICIENT_UNALIGNED_ACCESS 206 select HAVE_FAST_GUP 207 select HAVE_FTRACE_MCOUNT_RECORD 208 select HAVE_FUNCTION_TRACER 209 select HAVE_FUNCTION_ERROR_INJECTION 210 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 211 select HAVE_FUNCTION_GRAPH_TRACER 212 select HAVE_GCC_PLUGINS 213 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 214 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 215 select HAVE_HW_BREAKPOINT if PERF_EVENTS 216 select HAVE_IOREMAP_PROT 217 select HAVE_IRQ_TIME_ACCOUNTING 218 select HAVE_KVM 219 select HAVE_MOD_ARCH_SPECIFIC 220 select HAVE_NMI 221 select HAVE_PERF_EVENTS 222 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 223 select HAVE_PERF_REGS 224 select HAVE_PERF_USER_STACK_DUMP 225 select HAVE_PREEMPT_DYNAMIC_KEY 226 select HAVE_REGS_AND_STACK_ACCESS_API 227 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 228 select HAVE_FUNCTION_ARG_ACCESS_API 229 select MMU_GATHER_RCU_TABLE_FREE 230 select HAVE_RSEQ 231 select HAVE_STACKPROTECTOR 232 select HAVE_SYSCALL_TRACEPOINTS 233 select HAVE_KPROBES 234 select HAVE_KRETPROBES 235 select HAVE_GENERIC_VDSO 236 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 237 select IRQ_DOMAIN 238 select IRQ_FORCED_THREADING 239 select KASAN_VMALLOC if KASAN 240 select LOCK_MM_AND_FIND_VMA 241 select MODULES_USE_ELF_RELA 242 select NEED_DMA_MAP_STATE 243 select NEED_SG_DMA_LENGTH 244 select OF 245 select OF_EARLY_FLATTREE 246 select PCI_DOMAINS_GENERIC if PCI 247 select PCI_ECAM if (ACPI && PCI) 248 select PCI_SYSCALL if PCI 249 select POWER_RESET 250 select POWER_SUPPLY 251 select SPARSE_IRQ 252 select SWIOTLB 253 select SYSCTL_EXCEPTION_TRACE 254 select THREAD_INFO_IN_TASK 255 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 256 select TRACE_IRQFLAGS_SUPPORT 257 select TRACE_IRQFLAGS_NMI_SUPPORT 258 select HAVE_SOFTIRQ_ON_OWN_STACK 259 help 260 ARM 64-bit (AArch64) Linux support. 261 262config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 263 def_bool CC_IS_CLANG 264 # https://github.com/ClangBuiltLinux/linux/issues/1507 265 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 266 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 267 268config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 269 def_bool CC_IS_GCC 270 depends on $(cc-option,-fpatchable-function-entry=2) 271 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 272 273config 64BIT 274 def_bool y 275 276config MMU 277 def_bool y 278 279config ARM64_PAGE_SHIFT 280 int 281 default 16 if ARM64_64K_PAGES 282 default 14 if ARM64_16K_PAGES 283 default 12 284 285config ARM64_CONT_PTE_SHIFT 286 int 287 default 5 if ARM64_64K_PAGES 288 default 7 if ARM64_16K_PAGES 289 default 4 290 291config ARM64_CONT_PMD_SHIFT 292 int 293 default 5 if ARM64_64K_PAGES 294 default 5 if ARM64_16K_PAGES 295 default 4 296 297config ARCH_MMAP_RND_BITS_MIN 298 default 14 if ARM64_64K_PAGES 299 default 16 if ARM64_16K_PAGES 300 default 18 301 302# max bits determined by the following formula: 303# VA_BITS - PAGE_SHIFT - 3 304config ARCH_MMAP_RND_BITS_MAX 305 default 19 if ARM64_VA_BITS=36 306 default 24 if ARM64_VA_BITS=39 307 default 27 if ARM64_VA_BITS=42 308 default 30 if ARM64_VA_BITS=47 309 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 310 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 311 default 33 if ARM64_VA_BITS=48 312 default 14 if ARM64_64K_PAGES 313 default 16 if ARM64_16K_PAGES 314 default 18 315 316config ARCH_MMAP_RND_COMPAT_BITS_MIN 317 default 7 if ARM64_64K_PAGES 318 default 9 if ARM64_16K_PAGES 319 default 11 320 321config ARCH_MMAP_RND_COMPAT_BITS_MAX 322 default 16 323 324config NO_IOPORT_MAP 325 def_bool y if !PCI 326 327config STACKTRACE_SUPPORT 328 def_bool y 329 330config ILLEGAL_POINTER_VALUE 331 hex 332 default 0xdead000000000000 333 334config LOCKDEP_SUPPORT 335 def_bool y 336 337config GENERIC_BUG 338 def_bool y 339 depends on BUG 340 341config GENERIC_BUG_RELATIVE_POINTERS 342 def_bool y 343 depends on GENERIC_BUG 344 345config GENERIC_HWEIGHT 346 def_bool y 347 348config GENERIC_CSUM 349 def_bool y 350 351config GENERIC_CALIBRATE_DELAY 352 def_bool y 353 354config SMP 355 def_bool y 356 357config KERNEL_MODE_NEON 358 def_bool y 359 360config FIX_EARLYCON_MEM 361 def_bool y 362 363config PGTABLE_LEVELS 364 int 365 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 366 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 367 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 368 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 369 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 370 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 371 372config ARCH_SUPPORTS_UPROBES 373 def_bool y 374 375config ARCH_PROC_KCORE_TEXT 376 def_bool y 377 378config BROKEN_GAS_INST 379 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 380 381config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 382 bool 383 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 384 # https://reviews.llvm.org/D75044 385 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 386 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 387 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 388 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 389 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 390 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 391 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 392 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 393 default n 394 395config KASAN_SHADOW_OFFSET 396 hex 397 depends on KASAN_GENERIC || KASAN_SW_TAGS 398 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 399 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 400 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 401 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 402 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 403 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 404 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 405 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 406 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 407 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 408 default 0xffffffffffffffff 409 410config UNWIND_TABLES 411 bool 412 413source "arch/arm64/Kconfig.platforms" 414 415menu "Kernel Features" 416 417menu "ARM errata workarounds via the alternatives framework" 418 419config AMPERE_ERRATUM_AC03_CPU_38 420 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 421 default y 422 help 423 This option adds an alternative code sequence to work around Ampere 424 erratum AC03_CPU_38 on AmpereOne. 425 426 The affected design reports FEAT_HAFDBS as not implemented in 427 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 428 as required by the architecture. The unadvertised HAFDBS 429 implementation suffers from an additional erratum where hardware 430 A/D updates can occur after a PTE has been marked invalid. 431 432 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 433 which avoids enabling unadvertised hardware Access Flag management 434 at stage-2. 435 436 If unsure, say Y. 437 438config ARM64_WORKAROUND_CLEAN_CACHE 439 bool 440 441config ARM64_ERRATUM_826319 442 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 443 default y 444 select ARM64_WORKAROUND_CLEAN_CACHE 445 help 446 This option adds an alternative code sequence to work around ARM 447 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 448 AXI master interface and an L2 cache. 449 450 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 451 and is unable to accept a certain write via this interface, it will 452 not progress on read data presented on the read data channel and the 453 system can deadlock. 454 455 The workaround promotes data cache clean instructions to 456 data cache clean-and-invalidate. 457 Please note that this does not necessarily enable the workaround, 458 as it depends on the alternative framework, which will only patch 459 the kernel if an affected CPU is detected. 460 461 If unsure, say Y. 462 463config ARM64_ERRATUM_827319 464 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 465 default y 466 select ARM64_WORKAROUND_CLEAN_CACHE 467 help 468 This option adds an alternative code sequence to work around ARM 469 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 470 master interface and an L2 cache. 471 472 Under certain conditions this erratum can cause a clean line eviction 473 to occur at the same time as another transaction to the same address 474 on the AMBA 5 CHI interface, which can cause data corruption if the 475 interconnect reorders the two transactions. 476 477 The workaround promotes data cache clean instructions to 478 data cache clean-and-invalidate. 479 Please note that this does not necessarily enable the workaround, 480 as it depends on the alternative framework, which will only patch 481 the kernel if an affected CPU is detected. 482 483 If unsure, say Y. 484 485config ARM64_ERRATUM_824069 486 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 487 default y 488 select ARM64_WORKAROUND_CLEAN_CACHE 489 help 490 This option adds an alternative code sequence to work around ARM 491 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 492 to a coherent interconnect. 493 494 If a Cortex-A53 processor is executing a store or prefetch for 495 write instruction at the same time as a processor in another 496 cluster is executing a cache maintenance operation to the same 497 address, then this erratum might cause a clean cache line to be 498 incorrectly marked as dirty. 499 500 The workaround promotes data cache clean instructions to 501 data cache clean-and-invalidate. 502 Please note that this option does not necessarily enable the 503 workaround, as it depends on the alternative framework, which will 504 only patch the kernel if an affected CPU is detected. 505 506 If unsure, say Y. 507 508config ARM64_ERRATUM_819472 509 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 510 default y 511 select ARM64_WORKAROUND_CLEAN_CACHE 512 help 513 This option adds an alternative code sequence to work around ARM 514 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 515 present when it is connected to a coherent interconnect. 516 517 If the processor is executing a load and store exclusive sequence at 518 the same time as a processor in another cluster is executing a cache 519 maintenance operation to the same address, then this erratum might 520 cause data corruption. 521 522 The workaround promotes data cache clean instructions to 523 data cache clean-and-invalidate. 524 Please note that this does not necessarily enable the workaround, 525 as it depends on the alternative framework, which will only patch 526 the kernel if an affected CPU is detected. 527 528 If unsure, say Y. 529 530config ARM64_ERRATUM_832075 531 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 532 default y 533 help 534 This option adds an alternative code sequence to work around ARM 535 erratum 832075 on Cortex-A57 parts up to r1p2. 536 537 Affected Cortex-A57 parts might deadlock when exclusive load/store 538 instructions to Write-Back memory are mixed with Device loads. 539 540 The workaround is to promote device loads to use Load-Acquire 541 semantics. 542 Please note that this does not necessarily enable the workaround, 543 as it depends on the alternative framework, which will only patch 544 the kernel if an affected CPU is detected. 545 546 If unsure, say Y. 547 548config ARM64_ERRATUM_834220 549 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 550 depends on KVM 551 default y 552 help 553 This option adds an alternative code sequence to work around ARM 554 erratum 834220 on Cortex-A57 parts up to r1p2. 555 556 Affected Cortex-A57 parts might report a Stage 2 translation 557 fault as the result of a Stage 1 fault for load crossing a 558 page boundary when there is a permission or device memory 559 alignment fault at Stage 1 and a translation fault at Stage 2. 560 561 The workaround is to verify that the Stage 1 translation 562 doesn't generate a fault before handling the Stage 2 fault. 563 Please note that this does not necessarily enable the workaround, 564 as it depends on the alternative framework, which will only patch 565 the kernel if an affected CPU is detected. 566 567 If unsure, say Y. 568 569config ARM64_ERRATUM_1742098 570 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 571 depends on COMPAT 572 default y 573 help 574 This option removes the AES hwcap for aarch32 user-space to 575 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 576 577 Affected parts may corrupt the AES state if an interrupt is 578 taken between a pair of AES instructions. These instructions 579 are only present if the cryptography extensions are present. 580 All software should have a fallback implementation for CPUs 581 that don't implement the cryptography extensions. 582 583 If unsure, say Y. 584 585config ARM64_ERRATUM_845719 586 bool "Cortex-A53: 845719: a load might read incorrect data" 587 depends on COMPAT 588 default y 589 help 590 This option adds an alternative code sequence to work around ARM 591 erratum 845719 on Cortex-A53 parts up to r0p4. 592 593 When running a compat (AArch32) userspace on an affected Cortex-A53 594 part, a load at EL0 from a virtual address that matches the bottom 32 595 bits of the virtual address used by a recent load at (AArch64) EL1 596 might return incorrect data. 597 598 The workaround is to write the contextidr_el1 register on exception 599 return to a 32-bit task. 600 Please note that this does not necessarily enable the workaround, 601 as it depends on the alternative framework, which will only patch 602 the kernel if an affected CPU is detected. 603 604 If unsure, say Y. 605 606config ARM64_ERRATUM_843419 607 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 608 default y 609 help 610 This option links the kernel with '--fix-cortex-a53-843419' and 611 enables PLT support to replace certain ADRP instructions, which can 612 cause subsequent memory accesses to use an incorrect address on 613 Cortex-A53 parts up to r0p4. 614 615 If unsure, say Y. 616 617config ARM64_LD_HAS_FIX_ERRATUM_843419 618 def_bool $(ld-option,--fix-cortex-a53-843419) 619 620config ARM64_ERRATUM_1024718 621 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 622 default y 623 help 624 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 625 626 Affected Cortex-A55 cores (all revisions) could cause incorrect 627 update of the hardware dirty bit when the DBM/AP bits are updated 628 without a break-before-make. The workaround is to disable the usage 629 of hardware DBM locally on the affected cores. CPUs not affected by 630 this erratum will continue to use the feature. 631 632 If unsure, say Y. 633 634config ARM64_ERRATUM_1418040 635 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 636 default y 637 depends on COMPAT 638 help 639 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 640 errata 1188873 and 1418040. 641 642 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 643 cause register corruption when accessing the timer registers 644 from AArch32 userspace. 645 646 If unsure, say Y. 647 648config ARM64_WORKAROUND_SPECULATIVE_AT 649 bool 650 651config ARM64_ERRATUM_1165522 652 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 653 default y 654 select ARM64_WORKAROUND_SPECULATIVE_AT 655 help 656 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 657 658 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 659 corrupted TLBs by speculating an AT instruction during a guest 660 context switch. 661 662 If unsure, say Y. 663 664config ARM64_ERRATUM_1319367 665 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 666 default y 667 select ARM64_WORKAROUND_SPECULATIVE_AT 668 help 669 This option adds work arounds for ARM Cortex-A57 erratum 1319537 670 and A72 erratum 1319367 671 672 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 673 speculating an AT instruction during a guest context switch. 674 675 If unsure, say Y. 676 677config ARM64_ERRATUM_1530923 678 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 679 default y 680 select ARM64_WORKAROUND_SPECULATIVE_AT 681 help 682 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 683 684 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 685 corrupted TLBs by speculating an AT instruction during a guest 686 context switch. 687 688 If unsure, say Y. 689 690config ARM64_WORKAROUND_REPEAT_TLBI 691 bool 692 693config ARM64_ERRATUM_2441007 694 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 695 default y 696 select ARM64_WORKAROUND_REPEAT_TLBI 697 help 698 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 699 700 Under very rare circumstances, affected Cortex-A55 CPUs 701 may not handle a race between a break-before-make sequence on one 702 CPU, and another CPU accessing the same page. This could allow a 703 store to a page that has been unmapped. 704 705 Work around this by adding the affected CPUs to the list that needs 706 TLB sequences to be done twice. 707 708 If unsure, say Y. 709 710config ARM64_ERRATUM_1286807 711 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 712 default y 713 select ARM64_WORKAROUND_REPEAT_TLBI 714 help 715 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 716 717 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 718 address for a cacheable mapping of a location is being 719 accessed by a core while another core is remapping the virtual 720 address to a new physical page using the recommended 721 break-before-make sequence, then under very rare circumstances 722 TLBI+DSB completes before a read using the translation being 723 invalidated has been observed by other observers. The 724 workaround repeats the TLBI+DSB operation. 725 726config ARM64_ERRATUM_1463225 727 bool "Cortex-A76: Software Step might prevent interrupt recognition" 728 default y 729 help 730 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 731 732 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 733 of a system call instruction (SVC) can prevent recognition of 734 subsequent interrupts when software stepping is disabled in the 735 exception handler of the system call and either kernel debugging 736 is enabled or VHE is in use. 737 738 Work around the erratum by triggering a dummy step exception 739 when handling a system call from a task that is being stepped 740 in a VHE configuration of the kernel. 741 742 If unsure, say Y. 743 744config ARM64_ERRATUM_1542419 745 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 746 default y 747 help 748 This option adds a workaround for ARM Neoverse-N1 erratum 749 1542419. 750 751 Affected Neoverse-N1 cores could execute a stale instruction when 752 modified by another CPU. The workaround depends on a firmware 753 counterpart. 754 755 Workaround the issue by hiding the DIC feature from EL0. This 756 forces user-space to perform cache maintenance. 757 758 If unsure, say Y. 759 760config ARM64_ERRATUM_1508412 761 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 762 default y 763 help 764 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 765 766 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 767 of a store-exclusive or read of PAR_EL1 and a load with device or 768 non-cacheable memory attributes. The workaround depends on a firmware 769 counterpart. 770 771 KVM guests must also have the workaround implemented or they can 772 deadlock the system. 773 774 Work around the issue by inserting DMB SY barriers around PAR_EL1 775 register reads and warning KVM users. The DMB barrier is sufficient 776 to prevent a speculative PAR_EL1 read. 777 778 If unsure, say Y. 779 780config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 781 bool 782 783config ARM64_ERRATUM_2051678 784 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 785 default y 786 help 787 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 788 Affected Cortex-A510 might not respect the ordering rules for 789 hardware update of the page table's dirty bit. The workaround 790 is to not enable the feature on affected CPUs. 791 792 If unsure, say Y. 793 794config ARM64_ERRATUM_2077057 795 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 796 default y 797 help 798 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 799 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 800 expected, but a Pointer Authentication trap is taken instead. The 801 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 802 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 803 804 This can only happen when EL2 is stepping EL1. 805 806 When these conditions occur, the SPSR_EL2 value is unchanged from the 807 previous guest entry, and can be restored from the in-memory copy. 808 809 If unsure, say Y. 810 811config ARM64_ERRATUM_2658417 812 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 813 default y 814 help 815 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 816 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 817 BFMMLA or VMMLA instructions in rare circumstances when a pair of 818 A510 CPUs are using shared neon hardware. As the sharing is not 819 discoverable by the kernel, hide the BF16 HWCAP to indicate that 820 user-space should not be using these instructions. 821 822 If unsure, say Y. 823 824config ARM64_ERRATUM_2119858 825 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 826 default y 827 depends on CORESIGHT_TRBE 828 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 829 help 830 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 831 832 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 833 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 834 the event of a WRAP event. 835 836 Work around the issue by always making sure we move the TRBPTR_EL1 by 837 256 bytes before enabling the buffer and filling the first 256 bytes of 838 the buffer with ETM ignore packets upon disabling. 839 840 If unsure, say Y. 841 842config ARM64_ERRATUM_2139208 843 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 844 default y 845 depends on CORESIGHT_TRBE 846 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 847 help 848 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 849 850 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 851 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 852 the event of a WRAP event. 853 854 Work around the issue by always making sure we move the TRBPTR_EL1 by 855 256 bytes before enabling the buffer and filling the first 256 bytes of 856 the buffer with ETM ignore packets upon disabling. 857 858 If unsure, say Y. 859 860config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 861 bool 862 863config ARM64_ERRATUM_2054223 864 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 865 default y 866 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 867 help 868 Enable workaround for ARM Cortex-A710 erratum 2054223 869 870 Affected cores may fail to flush the trace data on a TSB instruction, when 871 the PE is in trace prohibited state. This will cause losing a few bytes 872 of the trace cached. 873 874 Workaround is to issue two TSB consecutively on affected cores. 875 876 If unsure, say Y. 877 878config ARM64_ERRATUM_2067961 879 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 880 default y 881 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 882 help 883 Enable workaround for ARM Neoverse-N2 erratum 2067961 884 885 Affected cores may fail to flush the trace data on a TSB instruction, when 886 the PE is in trace prohibited state. This will cause losing a few bytes 887 of the trace cached. 888 889 Workaround is to issue two TSB consecutively on affected cores. 890 891 If unsure, say Y. 892 893config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 894 bool 895 896config ARM64_ERRATUM_2253138 897 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 898 depends on CORESIGHT_TRBE 899 default y 900 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 901 help 902 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 903 904 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 905 for TRBE. Under some conditions, the TRBE might generate a write to the next 906 virtually addressed page following the last page of the TRBE address space 907 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 908 909 Work around this in the driver by always making sure that there is a 910 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 911 912 If unsure, say Y. 913 914config ARM64_ERRATUM_2224489 915 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 916 depends on CORESIGHT_TRBE 917 default y 918 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 919 help 920 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 921 922 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 923 for TRBE. Under some conditions, the TRBE might generate a write to the next 924 virtually addressed page following the last page of the TRBE address space 925 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 926 927 Work around this in the driver by always making sure that there is a 928 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 929 930 If unsure, say Y. 931 932config ARM64_ERRATUM_2441009 933 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 934 default y 935 select ARM64_WORKAROUND_REPEAT_TLBI 936 help 937 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 938 939 Under very rare circumstances, affected Cortex-A510 CPUs 940 may not handle a race between a break-before-make sequence on one 941 CPU, and another CPU accessing the same page. This could allow a 942 store to a page that has been unmapped. 943 944 Work around this by adding the affected CPUs to the list that needs 945 TLB sequences to be done twice. 946 947 If unsure, say Y. 948 949config ARM64_ERRATUM_2064142 950 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 951 depends on CORESIGHT_TRBE 952 default y 953 help 954 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 955 956 Affected Cortex-A510 core might fail to write into system registers after the 957 TRBE has been disabled. Under some conditions after the TRBE has been disabled 958 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 959 and TRBTRG_EL1 will be ignored and will not be effected. 960 961 Work around this in the driver by executing TSB CSYNC and DSB after collection 962 is stopped and before performing a system register write to one of the affected 963 registers. 964 965 If unsure, say Y. 966 967config ARM64_ERRATUM_2038923 968 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 969 depends on CORESIGHT_TRBE 970 default y 971 help 972 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 973 974 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 975 prohibited within the CPU. As a result, the trace buffer or trace buffer state 976 might be corrupted. This happens after TRBE buffer has been enabled by setting 977 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 978 execution changes from a context, in which trace is prohibited to one where it 979 isn't, or vice versa. In these mentioned conditions, the view of whether trace 980 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 981 the trace buffer state might be corrupted. 982 983 Work around this in the driver by preventing an inconsistent view of whether the 984 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 985 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 986 two ISB instructions if no ERET is to take place. 987 988 If unsure, say Y. 989 990config ARM64_ERRATUM_1902691 991 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 992 depends on CORESIGHT_TRBE 993 default y 994 help 995 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 996 997 Affected Cortex-A510 core might cause trace data corruption, when being written 998 into the memory. Effectively TRBE is broken and hence cannot be used to capture 999 trace data. 1000 1001 Work around this problem in the driver by just preventing TRBE initialization on 1002 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1003 on such implementations. This will cover the kernel for any firmware that doesn't 1004 do this already. 1005 1006 If unsure, say Y. 1007 1008config ARM64_ERRATUM_2457168 1009 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1010 depends on ARM64_AMU_EXTN 1011 default y 1012 help 1013 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1014 1015 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1016 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1017 incorrectly giving a significantly higher output value. 1018 1019 Work around this problem by returning 0 when reading the affected counter in 1020 key locations that results in disabling all users of this counter. This effect 1021 is the same to firmware disabling affected counters. 1022 1023 If unsure, say Y. 1024 1025config ARM64_ERRATUM_2645198 1026 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1027 default y 1028 help 1029 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1030 1031 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1032 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1033 next instruction abort caused by permission fault. 1034 1035 Only user-space does executable to non-executable permission transition via 1036 mprotect() system call. Workaround the problem by doing a break-before-make 1037 TLB invalidation, for all changes to executable user space mappings. 1038 1039 If unsure, say Y. 1040 1041config ARM64_ERRATUM_2966298 1042 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1043 default y 1044 help 1045 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1046 1047 On an affected Cortex-A520 core, a speculatively executed unprivileged 1048 load might leak data from a privileged level via a cache side channel. 1049 1050 Work around this problem by executing a TLBI before returning to EL0. 1051 1052 If unsure, say Y. 1053 1054config CAVIUM_ERRATUM_22375 1055 bool "Cavium erratum 22375, 24313" 1056 default y 1057 help 1058 Enable workaround for errata 22375 and 24313. 1059 1060 This implements two gicv3-its errata workarounds for ThunderX. Both 1061 with a small impact affecting only ITS table allocation. 1062 1063 erratum 22375: only alloc 8MB table size 1064 erratum 24313: ignore memory access type 1065 1066 The fixes are in ITS initialization and basically ignore memory access 1067 type and table size provided by the TYPER and BASER registers. 1068 1069 If unsure, say Y. 1070 1071config CAVIUM_ERRATUM_23144 1072 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1073 depends on NUMA 1074 default y 1075 help 1076 ITS SYNC command hang for cross node io and collections/cpu mapping. 1077 1078 If unsure, say Y. 1079 1080config CAVIUM_ERRATUM_23154 1081 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1082 default y 1083 help 1084 The ThunderX GICv3 implementation requires a modified version for 1085 reading the IAR status to ensure data synchronization 1086 (access to icc_iar1_el1 is not sync'ed before and after). 1087 1088 It also suffers from erratum 38545 (also present on Marvell's 1089 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1090 spuriously presented to the CPU interface. 1091 1092 If unsure, say Y. 1093 1094config CAVIUM_ERRATUM_27456 1095 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1096 default y 1097 help 1098 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1099 instructions may cause the icache to become corrupted if it 1100 contains data for a non-current ASID. The fix is to 1101 invalidate the icache when changing the mm context. 1102 1103 If unsure, say Y. 1104 1105config CAVIUM_ERRATUM_30115 1106 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1107 default y 1108 help 1109 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1110 1.2, and T83 Pass 1.0, KVM guest execution may disable 1111 interrupts in host. Trapping both GICv3 group-0 and group-1 1112 accesses sidesteps the issue. 1113 1114 If unsure, say Y. 1115 1116config CAVIUM_TX2_ERRATUM_219 1117 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1118 default y 1119 help 1120 On Cavium ThunderX2, a load, store or prefetch instruction between a 1121 TTBR update and the corresponding context synchronizing operation can 1122 cause a spurious Data Abort to be delivered to any hardware thread in 1123 the CPU core. 1124 1125 Work around the issue by avoiding the problematic code sequence and 1126 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1127 trap handler performs the corresponding register access, skips the 1128 instruction and ensures context synchronization by virtue of the 1129 exception return. 1130 1131 If unsure, say Y. 1132 1133config FUJITSU_ERRATUM_010001 1134 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1135 default y 1136 help 1137 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1138 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1139 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1140 This fault occurs under a specific hardware condition when a 1141 load/store instruction performs an address translation using: 1142 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1143 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1144 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1145 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1146 1147 The workaround is to ensure these bits are clear in TCR_ELx. 1148 The workaround only affects the Fujitsu-A64FX. 1149 1150 If unsure, say Y. 1151 1152config HISILICON_ERRATUM_161600802 1153 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1154 default y 1155 help 1156 The HiSilicon Hip07 SoC uses the wrong redistributor base 1157 when issued ITS commands such as VMOVP and VMAPP, and requires 1158 a 128kB offset to be applied to the target address in this commands. 1159 1160 If unsure, say Y. 1161 1162config QCOM_FALKOR_ERRATUM_1003 1163 bool "Falkor E1003: Incorrect translation due to ASID change" 1164 default y 1165 help 1166 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1167 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1168 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1169 then only for entries in the walk cache, since the leaf translation 1170 is unchanged. Work around the erratum by invalidating the walk cache 1171 entries for the trampoline before entering the kernel proper. 1172 1173config QCOM_FALKOR_ERRATUM_1009 1174 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1175 default y 1176 select ARM64_WORKAROUND_REPEAT_TLBI 1177 help 1178 On Falkor v1, the CPU may prematurely complete a DSB following a 1179 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1180 one more time to fix the issue. 1181 1182 If unsure, say Y. 1183 1184config QCOM_QDF2400_ERRATUM_0065 1185 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1186 default y 1187 help 1188 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1189 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1190 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1191 1192 If unsure, say Y. 1193 1194config QCOM_FALKOR_ERRATUM_E1041 1195 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1196 default y 1197 help 1198 Falkor CPU may speculatively fetch instructions from an improper 1199 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1200 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1201 1202 If unsure, say Y. 1203 1204config NVIDIA_CARMEL_CNP_ERRATUM 1205 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1206 default y 1207 help 1208 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1209 invalidate shared TLB entries installed by a different core, as it would 1210 on standard ARM cores. 1211 1212 If unsure, say Y. 1213 1214config ROCKCHIP_ERRATUM_3588001 1215 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1216 default y 1217 help 1218 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1219 This means, that its sharability feature may not be used, even though it 1220 is supported by the IP itself. 1221 1222 If unsure, say Y. 1223 1224config SOCIONEXT_SYNQUACER_PREITS 1225 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1226 default y 1227 help 1228 Socionext Synquacer SoCs implement a separate h/w block to generate 1229 MSI doorbell writes with non-zero values for the device ID. 1230 1231 If unsure, say Y. 1232 1233endmenu # "ARM errata workarounds via the alternatives framework" 1234 1235choice 1236 prompt "Page size" 1237 default ARM64_4K_PAGES 1238 help 1239 Page size (translation granule) configuration. 1240 1241config ARM64_4K_PAGES 1242 bool "4KB" 1243 help 1244 This feature enables 4KB pages support. 1245 1246config ARM64_16K_PAGES 1247 bool "16KB" 1248 help 1249 The system will use 16KB pages support. AArch32 emulation 1250 requires applications compiled with 16K (or a multiple of 16K) 1251 aligned segments. 1252 1253config ARM64_64K_PAGES 1254 bool "64KB" 1255 help 1256 This feature enables 64KB pages support (4KB by default) 1257 allowing only two levels of page tables and faster TLB 1258 look-up. AArch32 emulation requires applications compiled 1259 with 64K aligned segments. 1260 1261endchoice 1262 1263choice 1264 prompt "Virtual address space size" 1265 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1266 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1267 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1268 help 1269 Allows choosing one of multiple possible virtual address 1270 space sizes. The level of translation table is determined by 1271 a combination of page size and virtual address space size. 1272 1273config ARM64_VA_BITS_36 1274 bool "36-bit" if EXPERT 1275 depends on ARM64_16K_PAGES 1276 1277config ARM64_VA_BITS_39 1278 bool "39-bit" 1279 depends on ARM64_4K_PAGES 1280 1281config ARM64_VA_BITS_42 1282 bool "42-bit" 1283 depends on ARM64_64K_PAGES 1284 1285config ARM64_VA_BITS_47 1286 bool "47-bit" 1287 depends on ARM64_16K_PAGES 1288 1289config ARM64_VA_BITS_48 1290 bool "48-bit" 1291 1292config ARM64_VA_BITS_52 1293 bool "52-bit" 1294 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1295 help 1296 Enable 52-bit virtual addressing for userspace when explicitly 1297 requested via a hint to mmap(). The kernel will also use 52-bit 1298 virtual addresses for its own mappings (provided HW support for 1299 this feature is available, otherwise it reverts to 48-bit). 1300 1301 NOTE: Enabling 52-bit virtual addressing in conjunction with 1302 ARMv8.3 Pointer Authentication will result in the PAC being 1303 reduced from 7 bits to 3 bits, which may have a significant 1304 impact on its susceptibility to brute-force attacks. 1305 1306 If unsure, select 48-bit virtual addressing instead. 1307 1308endchoice 1309 1310config ARM64_FORCE_52BIT 1311 bool "Force 52-bit virtual addresses for userspace" 1312 depends on ARM64_VA_BITS_52 && EXPERT 1313 help 1314 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1315 to maintain compatibility with older software by providing 48-bit VAs 1316 unless a hint is supplied to mmap. 1317 1318 This configuration option disables the 48-bit compatibility logic, and 1319 forces all userspace addresses to be 52-bit on HW that supports it. One 1320 should only enable this configuration option for stress testing userspace 1321 memory management code. If unsure say N here. 1322 1323config ARM64_VA_BITS 1324 int 1325 default 36 if ARM64_VA_BITS_36 1326 default 39 if ARM64_VA_BITS_39 1327 default 42 if ARM64_VA_BITS_42 1328 default 47 if ARM64_VA_BITS_47 1329 default 48 if ARM64_VA_BITS_48 1330 default 52 if ARM64_VA_BITS_52 1331 1332choice 1333 prompt "Physical address space size" 1334 default ARM64_PA_BITS_48 1335 help 1336 Choose the maximum physical address range that the kernel will 1337 support. 1338 1339config ARM64_PA_BITS_48 1340 bool "48-bit" 1341 1342config ARM64_PA_BITS_52 1343 bool "52-bit (ARMv8.2)" 1344 depends on ARM64_64K_PAGES 1345 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1346 help 1347 Enable support for a 52-bit physical address space, introduced as 1348 part of the ARMv8.2-LPA extension. 1349 1350 With this enabled, the kernel will also continue to work on CPUs that 1351 do not support ARMv8.2-LPA, but with some added memory overhead (and 1352 minor performance overhead). 1353 1354endchoice 1355 1356config ARM64_PA_BITS 1357 int 1358 default 48 if ARM64_PA_BITS_48 1359 default 52 if ARM64_PA_BITS_52 1360 1361choice 1362 prompt "Endianness" 1363 default CPU_LITTLE_ENDIAN 1364 help 1365 Select the endianness of data accesses performed by the CPU. Userspace 1366 applications will need to be compiled and linked for the endianness 1367 that is selected here. 1368 1369config CPU_BIG_ENDIAN 1370 bool "Build big-endian kernel" 1371 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1372 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1373 depends on AS_IS_GNU || AS_VERSION >= 150000 1374 help 1375 Say Y if you plan on running a kernel with a big-endian userspace. 1376 1377config CPU_LITTLE_ENDIAN 1378 bool "Build little-endian kernel" 1379 help 1380 Say Y if you plan on running a kernel with a little-endian userspace. 1381 This is usually the case for distributions targeting arm64. 1382 1383endchoice 1384 1385config SCHED_MC 1386 bool "Multi-core scheduler support" 1387 help 1388 Multi-core scheduler support improves the CPU scheduler's decision 1389 making when dealing with multi-core CPU chips at a cost of slightly 1390 increased overhead in some places. If unsure say N here. 1391 1392config SCHED_CLUSTER 1393 bool "Cluster scheduler support" 1394 help 1395 Cluster scheduler support improves the CPU scheduler's decision 1396 making when dealing with machines that have clusters of CPUs. 1397 Cluster usually means a couple of CPUs which are placed closely 1398 by sharing mid-level caches, last-level cache tags or internal 1399 busses. 1400 1401config SCHED_SMT 1402 bool "SMT scheduler support" 1403 help 1404 Improves the CPU scheduler's decision making when dealing with 1405 MultiThreading at a cost of slightly increased overhead in some 1406 places. If unsure say N here. 1407 1408config NR_CPUS 1409 int "Maximum number of CPUs (2-4096)" 1410 range 2 4096 1411 default "256" 1412 1413config HOTPLUG_CPU 1414 bool "Support for hot-pluggable CPUs" 1415 select GENERIC_IRQ_MIGRATION 1416 help 1417 Say Y here to experiment with turning CPUs off and on. CPUs 1418 can be controlled through /sys/devices/system/cpu. 1419 1420# Common NUMA Features 1421config NUMA 1422 bool "NUMA Memory Allocation and Scheduler Support" 1423 select GENERIC_ARCH_NUMA 1424 select ACPI_NUMA if ACPI 1425 select OF_NUMA 1426 select HAVE_SETUP_PER_CPU_AREA 1427 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1428 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1429 select USE_PERCPU_NUMA_NODE_ID 1430 help 1431 Enable NUMA (Non-Uniform Memory Access) support. 1432 1433 The kernel will try to allocate memory used by a CPU on the 1434 local memory of the CPU and add some more 1435 NUMA awareness to the kernel. 1436 1437config NODES_SHIFT 1438 int "Maximum NUMA Nodes (as a power of 2)" 1439 range 1 10 1440 default "4" 1441 depends on NUMA 1442 help 1443 Specify the maximum number of NUMA Nodes available on the target 1444 system. Increases memory reserved to accommodate various tables. 1445 1446source "kernel/Kconfig.hz" 1447 1448config ARCH_SPARSEMEM_ENABLE 1449 def_bool y 1450 select SPARSEMEM_VMEMMAP_ENABLE 1451 select SPARSEMEM_VMEMMAP 1452 1453config HW_PERF_EVENTS 1454 def_bool y 1455 depends on ARM_PMU 1456 1457# Supported by clang >= 7.0 or GCC >= 12.0.0 1458config CC_HAVE_SHADOW_CALL_STACK 1459 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1460 1461config PARAVIRT 1462 bool "Enable paravirtualization code" 1463 help 1464 This changes the kernel so it can modify itself when it is run 1465 under a hypervisor, potentially improving performance significantly 1466 over full virtualization. 1467 1468config PARAVIRT_TIME_ACCOUNTING 1469 bool "Paravirtual steal time accounting" 1470 select PARAVIRT 1471 help 1472 Select this option to enable fine granularity task steal time 1473 accounting. Time spent executing other tasks in parallel with 1474 the current vCPU is discounted from the vCPU power. To account for 1475 that, there can be a small performance impact. 1476 1477 If in doubt, say N here. 1478 1479config ARCH_SUPPORTS_KEXEC 1480 def_bool PM_SLEEP_SMP 1481 1482config ARCH_SUPPORTS_KEXEC_FILE 1483 def_bool y 1484 1485config ARCH_SELECTS_KEXEC_FILE 1486 def_bool y 1487 depends on KEXEC_FILE 1488 select HAVE_IMA_KEXEC if IMA 1489 1490config ARCH_SUPPORTS_KEXEC_SIG 1491 def_bool y 1492 1493config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1494 def_bool y 1495 1496config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1497 def_bool y 1498 1499config ARCH_SUPPORTS_CRASH_DUMP 1500 def_bool y 1501 1502config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1503 def_bool CRASH_CORE 1504 1505config TRANS_TABLE 1506 def_bool y 1507 depends on HIBERNATION || KEXEC_CORE 1508 1509config XEN_DOM0 1510 def_bool y 1511 depends on XEN 1512 1513config XEN 1514 bool "Xen guest support on ARM64" 1515 depends on ARM64 && OF 1516 select SWIOTLB_XEN 1517 select PARAVIRT 1518 help 1519 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1520 1521# include/linux/mmzone.h requires the following to be true: 1522# 1523# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1524# 1525# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1526# 1527# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1528# ----+-------------------+--------------+----------------------+-------------------------+ 1529# 4K | 27 | 12 | 15 | 10 | 1530# 16K | 27 | 14 | 13 | 11 | 1531# 64K | 29 | 16 | 13 | 13 | 1532config ARCH_FORCE_MAX_ORDER 1533 int 1534 default "13" if ARM64_64K_PAGES 1535 default "11" if ARM64_16K_PAGES 1536 default "10" 1537 help 1538 The kernel page allocator limits the size of maximal physically 1539 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1540 defines the maximal power of two of number of pages that can be 1541 allocated as a single contiguous block. This option allows 1542 overriding the default setting when ability to allocate very 1543 large blocks of physically contiguous memory is required. 1544 1545 The maximal size of allocation cannot exceed the size of the 1546 section, so the value of MAX_PAGE_ORDER should satisfy 1547 1548 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1549 1550 Don't change if unsure. 1551 1552config UNMAP_KERNEL_AT_EL0 1553 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1554 default y 1555 help 1556 Speculation attacks against some high-performance processors can 1557 be used to bypass MMU permission checks and leak kernel data to 1558 userspace. This can be defended against by unmapping the kernel 1559 when running in userspace, mapping it back in on exception entry 1560 via a trampoline page in the vector table. 1561 1562 If unsure, say Y. 1563 1564config MITIGATE_SPECTRE_BRANCH_HISTORY 1565 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1566 default y 1567 help 1568 Speculation attacks against some high-performance processors can 1569 make use of branch history to influence future speculation. 1570 When taking an exception from user-space, a sequence of branches 1571 or a firmware call overwrites the branch history. 1572 1573config RODATA_FULL_DEFAULT_ENABLED 1574 bool "Apply r/o permissions of VM areas also to their linear aliases" 1575 default y 1576 help 1577 Apply read-only attributes of VM areas to the linear alias of 1578 the backing pages as well. This prevents code or read-only data 1579 from being modified (inadvertently or intentionally) via another 1580 mapping of the same memory page. This additional enhancement can 1581 be turned off at runtime by passing rodata=[off|on] (and turned on 1582 with rodata=full if this option is set to 'n') 1583 1584 This requires the linear region to be mapped down to pages, 1585 which may adversely affect performance in some cases. 1586 1587config ARM64_SW_TTBR0_PAN 1588 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1589 help 1590 Enabling this option prevents the kernel from accessing 1591 user-space memory directly by pointing TTBR0_EL1 to a reserved 1592 zeroed area and reserved ASID. The user access routines 1593 restore the valid TTBR0_EL1 temporarily. 1594 1595config ARM64_TAGGED_ADDR_ABI 1596 bool "Enable the tagged user addresses syscall ABI" 1597 default y 1598 help 1599 When this option is enabled, user applications can opt in to a 1600 relaxed ABI via prctl() allowing tagged addresses to be passed 1601 to system calls as pointer arguments. For details, see 1602 Documentation/arch/arm64/tagged-address-abi.rst. 1603 1604menuconfig COMPAT 1605 bool "Kernel support for 32-bit EL0" 1606 depends on ARM64_4K_PAGES || EXPERT 1607 select HAVE_UID16 1608 select OLD_SIGSUSPEND3 1609 select COMPAT_OLD_SIGACTION 1610 help 1611 This option enables support for a 32-bit EL0 running under a 64-bit 1612 kernel at EL1. AArch32-specific components such as system calls, 1613 the user helper functions, VFP support and the ptrace interface are 1614 handled appropriately by the kernel. 1615 1616 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1617 that you will only be able to execute AArch32 binaries that were compiled 1618 with page size aligned segments. 1619 1620 If you want to execute 32-bit userspace applications, say Y. 1621 1622if COMPAT 1623 1624config KUSER_HELPERS 1625 bool "Enable kuser helpers page for 32-bit applications" 1626 default y 1627 help 1628 Warning: disabling this option may break 32-bit user programs. 1629 1630 Provide kuser helpers to compat tasks. The kernel provides 1631 helper code to userspace in read only form at a fixed location 1632 to allow userspace to be independent of the CPU type fitted to 1633 the system. This permits binaries to be run on ARMv4 through 1634 to ARMv8 without modification. 1635 1636 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1637 1638 However, the fixed address nature of these helpers can be used 1639 by ROP (return orientated programming) authors when creating 1640 exploits. 1641 1642 If all of the binaries and libraries which run on your platform 1643 are built specifically for your platform, and make no use of 1644 these helpers, then you can turn this option off to hinder 1645 such exploits. However, in that case, if a binary or library 1646 relying on those helpers is run, it will not function correctly. 1647 1648 Say N here only if you are absolutely certain that you do not 1649 need these helpers; otherwise, the safe option is to say Y. 1650 1651config COMPAT_VDSO 1652 bool "Enable vDSO for 32-bit applications" 1653 depends on !CPU_BIG_ENDIAN 1654 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1655 select GENERIC_COMPAT_VDSO 1656 default y 1657 help 1658 Place in the process address space of 32-bit applications an 1659 ELF shared object providing fast implementations of gettimeofday 1660 and clock_gettime. 1661 1662 You must have a 32-bit build of glibc 2.22 or later for programs 1663 to seamlessly take advantage of this. 1664 1665config THUMB2_COMPAT_VDSO 1666 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1667 depends on COMPAT_VDSO 1668 default y 1669 help 1670 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1671 otherwise with '-marm'. 1672 1673config COMPAT_ALIGNMENT_FIXUPS 1674 bool "Fix up misaligned multi-word loads and stores in user space" 1675 1676menuconfig ARMV8_DEPRECATED 1677 bool "Emulate deprecated/obsolete ARMv8 instructions" 1678 depends on SYSCTL 1679 help 1680 Legacy software support may require certain instructions 1681 that have been deprecated or obsoleted in the architecture. 1682 1683 Enable this config to enable selective emulation of these 1684 features. 1685 1686 If unsure, say Y 1687 1688if ARMV8_DEPRECATED 1689 1690config SWP_EMULATION 1691 bool "Emulate SWP/SWPB instructions" 1692 help 1693 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1694 they are always undefined. Say Y here to enable software 1695 emulation of these instructions for userspace using LDXR/STXR. 1696 This feature can be controlled at runtime with the abi.swp 1697 sysctl which is disabled by default. 1698 1699 In some older versions of glibc [<=2.8] SWP is used during futex 1700 trylock() operations with the assumption that the code will not 1701 be preempted. This invalid assumption may be more likely to fail 1702 with SWP emulation enabled, leading to deadlock of the user 1703 application. 1704 1705 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1706 on an external transaction monitoring block called a global 1707 monitor to maintain update atomicity. If your system does not 1708 implement a global monitor, this option can cause programs that 1709 perform SWP operations to uncached memory to deadlock. 1710 1711 If unsure, say Y 1712 1713config CP15_BARRIER_EMULATION 1714 bool "Emulate CP15 Barrier instructions" 1715 help 1716 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1717 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1718 strongly recommended to use the ISB, DSB, and DMB 1719 instructions instead. 1720 1721 Say Y here to enable software emulation of these 1722 instructions for AArch32 userspace code. When this option is 1723 enabled, CP15 barrier usage is traced which can help 1724 identify software that needs updating. This feature can be 1725 controlled at runtime with the abi.cp15_barrier sysctl. 1726 1727 If unsure, say Y 1728 1729config SETEND_EMULATION 1730 bool "Emulate SETEND instruction" 1731 help 1732 The SETEND instruction alters the data-endianness of the 1733 AArch32 EL0, and is deprecated in ARMv8. 1734 1735 Say Y here to enable software emulation of the instruction 1736 for AArch32 userspace code. This feature can be controlled 1737 at runtime with the abi.setend sysctl. 1738 1739 Note: All the cpus on the system must have mixed endian support at EL0 1740 for this feature to be enabled. If a new CPU - which doesn't support mixed 1741 endian - is hotplugged in after this feature has been enabled, there could 1742 be unexpected results in the applications. 1743 1744 If unsure, say Y 1745endif # ARMV8_DEPRECATED 1746 1747endif # COMPAT 1748 1749menu "ARMv8.1 architectural features" 1750 1751config ARM64_HW_AFDBM 1752 bool "Support for hardware updates of the Access and Dirty page flags" 1753 default y 1754 help 1755 The ARMv8.1 architecture extensions introduce support for 1756 hardware updates of the access and dirty information in page 1757 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1758 capable processors, accesses to pages with PTE_AF cleared will 1759 set this bit instead of raising an access flag fault. 1760 Similarly, writes to read-only pages with the DBM bit set will 1761 clear the read-only bit (AP[2]) instead of raising a 1762 permission fault. 1763 1764 Kernels built with this configuration option enabled continue 1765 to work on pre-ARMv8.1 hardware and the performance impact is 1766 minimal. If unsure, say Y. 1767 1768config ARM64_PAN 1769 bool "Enable support for Privileged Access Never (PAN)" 1770 default y 1771 help 1772 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1773 prevents the kernel or hypervisor from accessing user-space (EL0) 1774 memory directly. 1775 1776 Choosing this option will cause any unprotected (not using 1777 copy_to_user et al) memory access to fail with a permission fault. 1778 1779 The feature is detected at runtime, and will remain as a 'nop' 1780 instruction if the cpu does not implement the feature. 1781 1782config AS_HAS_LSE_ATOMICS 1783 def_bool $(as-instr,.arch_extension lse) 1784 1785config ARM64_LSE_ATOMICS 1786 bool 1787 default ARM64_USE_LSE_ATOMICS 1788 depends on AS_HAS_LSE_ATOMICS 1789 1790config ARM64_USE_LSE_ATOMICS 1791 bool "Atomic instructions" 1792 default y 1793 help 1794 As part of the Large System Extensions, ARMv8.1 introduces new 1795 atomic instructions that are designed specifically to scale in 1796 very large systems. 1797 1798 Say Y here to make use of these instructions for the in-kernel 1799 atomic routines. This incurs a small overhead on CPUs that do 1800 not support these instructions and requires the kernel to be 1801 built with binutils >= 2.25 in order for the new instructions 1802 to be used. 1803 1804endmenu # "ARMv8.1 architectural features" 1805 1806menu "ARMv8.2 architectural features" 1807 1808config AS_HAS_ARMV8_2 1809 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1810 1811config AS_HAS_SHA3 1812 def_bool $(as-instr,.arch armv8.2-a+sha3) 1813 1814config ARM64_PMEM 1815 bool "Enable support for persistent memory" 1816 select ARCH_HAS_PMEM_API 1817 select ARCH_HAS_UACCESS_FLUSHCACHE 1818 help 1819 Say Y to enable support for the persistent memory API based on the 1820 ARMv8.2 DCPoP feature. 1821 1822 The feature is detected at runtime, and the kernel will use DC CVAC 1823 operations if DC CVAP is not supported (following the behaviour of 1824 DC CVAP itself if the system does not define a point of persistence). 1825 1826config ARM64_RAS_EXTN 1827 bool "Enable support for RAS CPU Extensions" 1828 default y 1829 help 1830 CPUs that support the Reliability, Availability and Serviceability 1831 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1832 errors, classify them and report them to software. 1833 1834 On CPUs with these extensions system software can use additional 1835 barriers to determine if faults are pending and read the 1836 classification from a new set of registers. 1837 1838 Selecting this feature will allow the kernel to use these barriers 1839 and access the new registers if the system supports the extension. 1840 Platform RAS features may additionally depend on firmware support. 1841 1842config ARM64_CNP 1843 bool "Enable support for Common Not Private (CNP) translations" 1844 default y 1845 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1846 help 1847 Common Not Private (CNP) allows translation table entries to 1848 be shared between different PEs in the same inner shareable 1849 domain, so the hardware can use this fact to optimise the 1850 caching of such entries in the TLB. 1851 1852 Selecting this option allows the CNP feature to be detected 1853 at runtime, and does not affect PEs that do not implement 1854 this feature. 1855 1856endmenu # "ARMv8.2 architectural features" 1857 1858menu "ARMv8.3 architectural features" 1859 1860config ARM64_PTR_AUTH 1861 bool "Enable support for pointer authentication" 1862 default y 1863 help 1864 Pointer authentication (part of the ARMv8.3 Extensions) provides 1865 instructions for signing and authenticating pointers against secret 1866 keys, which can be used to mitigate Return Oriented Programming (ROP) 1867 and other attacks. 1868 1869 This option enables these instructions at EL0 (i.e. for userspace). 1870 Choosing this option will cause the kernel to initialise secret keys 1871 for each process at exec() time, with these keys being 1872 context-switched along with the process. 1873 1874 The feature is detected at runtime. If the feature is not present in 1875 hardware it will not be advertised to userspace/KVM guest nor will it 1876 be enabled. 1877 1878 If the feature is present on the boot CPU but not on a late CPU, then 1879 the late CPU will be parked. Also, if the boot CPU does not have 1880 address auth and the late CPU has then the late CPU will still boot 1881 but with the feature disabled. On such a system, this option should 1882 not be selected. 1883 1884config ARM64_PTR_AUTH_KERNEL 1885 bool "Use pointer authentication for kernel" 1886 default y 1887 depends on ARM64_PTR_AUTH 1888 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1889 # Modern compilers insert a .note.gnu.property section note for PAC 1890 # which is only understood by binutils starting with version 2.33.1. 1891 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1892 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1893 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1894 help 1895 If the compiler supports the -mbranch-protection or 1896 -msign-return-address flag (e.g. GCC 7 or later), then this option 1897 will cause the kernel itself to be compiled with return address 1898 protection. In this case, and if the target hardware is known to 1899 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1900 disabled with minimal loss of protection. 1901 1902 This feature works with FUNCTION_GRAPH_TRACER option only if 1903 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1904 1905config CC_HAS_BRANCH_PROT_PAC_RET 1906 # GCC 9 or later, clang 8 or later 1907 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1908 1909config CC_HAS_SIGN_RETURN_ADDRESS 1910 # GCC 7, 8 1911 def_bool $(cc-option,-msign-return-address=all) 1912 1913config AS_HAS_ARMV8_3 1914 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1915 1916config AS_HAS_CFI_NEGATE_RA_STATE 1917 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1918 1919config AS_HAS_LDAPR 1920 def_bool $(as-instr,.arch_extension rcpc) 1921 1922endmenu # "ARMv8.3 architectural features" 1923 1924menu "ARMv8.4 architectural features" 1925 1926config ARM64_AMU_EXTN 1927 bool "Enable support for the Activity Monitors Unit CPU extension" 1928 default y 1929 help 1930 The activity monitors extension is an optional extension introduced 1931 by the ARMv8.4 CPU architecture. This enables support for version 1 1932 of the activity monitors architecture, AMUv1. 1933 1934 To enable the use of this extension on CPUs that implement it, say Y. 1935 1936 Note that for architectural reasons, firmware _must_ implement AMU 1937 support when running on CPUs that present the activity monitors 1938 extension. The required support is present in: 1939 * Version 1.5 and later of the ARM Trusted Firmware 1940 1941 For kernels that have this configuration enabled but boot with broken 1942 firmware, you may need to say N here until the firmware is fixed. 1943 Otherwise you may experience firmware panics or lockups when 1944 accessing the counter registers. Even if you are not observing these 1945 symptoms, the values returned by the register reads might not 1946 correctly reflect reality. Most commonly, the value read will be 0, 1947 indicating that the counter is not enabled. 1948 1949config AS_HAS_ARMV8_4 1950 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1951 1952config ARM64_TLB_RANGE 1953 bool "Enable support for tlbi range feature" 1954 default y 1955 depends on AS_HAS_ARMV8_4 1956 help 1957 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1958 range of input addresses. 1959 1960 The feature introduces new assembly instructions, and they were 1961 support when binutils >= 2.30. 1962 1963endmenu # "ARMv8.4 architectural features" 1964 1965menu "ARMv8.5 architectural features" 1966 1967config AS_HAS_ARMV8_5 1968 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1969 1970config ARM64_BTI 1971 bool "Branch Target Identification support" 1972 default y 1973 help 1974 Branch Target Identification (part of the ARMv8.5 Extensions) 1975 provides a mechanism to limit the set of locations to which computed 1976 branch instructions such as BR or BLR can jump. 1977 1978 To make use of BTI on CPUs that support it, say Y. 1979 1980 BTI is intended to provide complementary protection to other control 1981 flow integrity protection mechanisms, such as the Pointer 1982 authentication mechanism provided as part of the ARMv8.3 Extensions. 1983 For this reason, it does not make sense to enable this option without 1984 also enabling support for pointer authentication. Thus, when 1985 enabling this option you should also select ARM64_PTR_AUTH=y. 1986 1987 Userspace binaries must also be specifically compiled to make use of 1988 this mechanism. If you say N here or the hardware does not support 1989 BTI, such binaries can still run, but you get no additional 1990 enforcement of branch destinations. 1991 1992config ARM64_BTI_KERNEL 1993 bool "Use Branch Target Identification for kernel" 1994 default y 1995 depends on ARM64_BTI 1996 depends on ARM64_PTR_AUTH_KERNEL 1997 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1998 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1999 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2000 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2001 depends on !CC_IS_GCC 2002 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 2003 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 2004 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2005 help 2006 Build the kernel with Branch Target Identification annotations 2007 and enable enforcement of this for kernel code. When this option 2008 is enabled and the system supports BTI all kernel code including 2009 modular code must have BTI enabled. 2010 2011config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2012 # GCC 9 or later, clang 8 or later 2013 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2014 2015config ARM64_E0PD 2016 bool "Enable support for E0PD" 2017 default y 2018 help 2019 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2020 that EL0 accesses made via TTBR1 always fault in constant time, 2021 providing similar benefits to KASLR as those provided by KPTI, but 2022 with lower overhead and without disrupting legitimate access to 2023 kernel memory such as SPE. 2024 2025 This option enables E0PD for TTBR1 where available. 2026 2027config ARM64_AS_HAS_MTE 2028 # Initial support for MTE went in binutils 2.32.0, checked with 2029 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2030 # as a late addition to the final architecture spec (LDGM/STGM) 2031 # is only supported in the newer 2.32.x and 2.33 binutils 2032 # versions, hence the extra "stgm" instruction check below. 2033 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2034 2035config ARM64_MTE 2036 bool "Memory Tagging Extension support" 2037 default y 2038 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2039 depends on AS_HAS_ARMV8_5 2040 depends on AS_HAS_LSE_ATOMICS 2041 # Required for tag checking in the uaccess routines 2042 depends on ARM64_PAN 2043 select ARCH_HAS_SUBPAGE_FAULTS 2044 select ARCH_USES_HIGH_VMA_FLAGS 2045 select ARCH_USES_PG_ARCH_X 2046 help 2047 Memory Tagging (part of the ARMv8.5 Extensions) provides 2048 architectural support for run-time, always-on detection of 2049 various classes of memory error to aid with software debugging 2050 to eliminate vulnerabilities arising from memory-unsafe 2051 languages. 2052 2053 This option enables the support for the Memory Tagging 2054 Extension at EL0 (i.e. for userspace). 2055 2056 Selecting this option allows the feature to be detected at 2057 runtime. Any secondary CPU not implementing this feature will 2058 not be allowed a late bring-up. 2059 2060 Userspace binaries that want to use this feature must 2061 explicitly opt in. The mechanism for the userspace is 2062 described in: 2063 2064 Documentation/arch/arm64/memory-tagging-extension.rst. 2065 2066endmenu # "ARMv8.5 architectural features" 2067 2068menu "ARMv8.7 architectural features" 2069 2070config ARM64_EPAN 2071 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2072 default y 2073 depends on ARM64_PAN 2074 help 2075 Enhanced Privileged Access Never (EPAN) allows Privileged 2076 Access Never to be used with Execute-only mappings. 2077 2078 The feature is detected at runtime, and will remain disabled 2079 if the cpu does not implement the feature. 2080endmenu # "ARMv8.7 architectural features" 2081 2082config ARM64_SVE 2083 bool "ARM Scalable Vector Extension support" 2084 default y 2085 help 2086 The Scalable Vector Extension (SVE) is an extension to the AArch64 2087 execution state which complements and extends the SIMD functionality 2088 of the base architecture to support much larger vectors and to enable 2089 additional vectorisation opportunities. 2090 2091 To enable use of this extension on CPUs that implement it, say Y. 2092 2093 On CPUs that support the SVE2 extensions, this option will enable 2094 those too. 2095 2096 Note that for architectural reasons, firmware _must_ implement SVE 2097 support when running on SVE capable hardware. The required support 2098 is present in: 2099 2100 * version 1.5 and later of the ARM Trusted Firmware 2101 * the AArch64 boot wrapper since commit 5e1261e08abf 2102 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2103 2104 For other firmware implementations, consult the firmware documentation 2105 or vendor. 2106 2107 If you need the kernel to boot on SVE-capable hardware with broken 2108 firmware, you may need to say N here until you get your firmware 2109 fixed. Otherwise, you may experience firmware panics or lockups when 2110 booting the kernel. If unsure and you are not observing these 2111 symptoms, you should assume that it is safe to say Y. 2112 2113config ARM64_SME 2114 bool "ARM Scalable Matrix Extension support" 2115 default y 2116 depends on ARM64_SVE 2117 help 2118 The Scalable Matrix Extension (SME) is an extension to the AArch64 2119 execution state which utilises a substantial subset of the SVE 2120 instruction set, together with the addition of new architectural 2121 register state capable of holding two dimensional matrix tiles to 2122 enable various matrix operations. 2123 2124config ARM64_PSEUDO_NMI 2125 bool "Support for NMI-like interrupts" 2126 select ARM_GIC_V3 2127 help 2128 Adds support for mimicking Non-Maskable Interrupts through the use of 2129 GIC interrupt priority. This support requires version 3 or later of 2130 ARM GIC. 2131 2132 This high priority configuration for interrupts needs to be 2133 explicitly enabled by setting the kernel parameter 2134 "irqchip.gicv3_pseudo_nmi" to 1. 2135 2136 If unsure, say N 2137 2138if ARM64_PSEUDO_NMI 2139config ARM64_DEBUG_PRIORITY_MASKING 2140 bool "Debug interrupt priority masking" 2141 help 2142 This adds runtime checks to functions enabling/disabling 2143 interrupts when using priority masking. The additional checks verify 2144 the validity of ICC_PMR_EL1 when calling concerned functions. 2145 2146 If unsure, say N 2147endif # ARM64_PSEUDO_NMI 2148 2149config RELOCATABLE 2150 bool "Build a relocatable kernel image" if EXPERT 2151 select ARCH_HAS_RELR 2152 default y 2153 help 2154 This builds the kernel as a Position Independent Executable (PIE), 2155 which retains all relocation metadata required to relocate the 2156 kernel binary at runtime to a different virtual address than the 2157 address it was linked at. 2158 Since AArch64 uses the RELA relocation format, this requires a 2159 relocation pass at runtime even if the kernel is loaded at the 2160 same address it was linked at. 2161 2162config RANDOMIZE_BASE 2163 bool "Randomize the address of the kernel image" 2164 select RELOCATABLE 2165 help 2166 Randomizes the virtual address at which the kernel image is 2167 loaded, as a security feature that deters exploit attempts 2168 relying on knowledge of the location of kernel internals. 2169 2170 It is the bootloader's job to provide entropy, by passing a 2171 random u64 value in /chosen/kaslr-seed at kernel entry. 2172 2173 When booting via the UEFI stub, it will invoke the firmware's 2174 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2175 to the kernel proper. In addition, it will randomise the physical 2176 location of the kernel Image as well. 2177 2178 If unsure, say N. 2179 2180config RANDOMIZE_MODULE_REGION_FULL 2181 bool "Randomize the module region over a 2 GB range" 2182 depends on RANDOMIZE_BASE 2183 default y 2184 help 2185 Randomizes the location of the module region inside a 2 GB window 2186 covering the core kernel. This way, it is less likely for modules 2187 to leak information about the location of core kernel data structures 2188 but it does imply that function calls between modules and the core 2189 kernel will need to be resolved via veneers in the module PLT. 2190 2191 When this option is not set, the module region will be randomized over 2192 a limited range that contains the [_stext, _etext] interval of the 2193 core kernel, so branch relocations are almost always in range unless 2194 the region is exhausted. In this particular case of region 2195 exhaustion, modules might be able to fall back to a larger 2GB area. 2196 2197config CC_HAVE_STACKPROTECTOR_SYSREG 2198 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2199 2200config STACKPROTECTOR_PER_TASK 2201 def_bool y 2202 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2203 2204config UNWIND_PATCH_PAC_INTO_SCS 2205 bool "Enable shadow call stack dynamically using code patching" 2206 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2207 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2208 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2209 depends on SHADOW_CALL_STACK 2210 select UNWIND_TABLES 2211 select DYNAMIC_SCS 2212 2213endmenu # "Kernel Features" 2214 2215menu "Boot options" 2216 2217config ARM64_ACPI_PARKING_PROTOCOL 2218 bool "Enable support for the ARM64 ACPI parking protocol" 2219 depends on ACPI 2220 help 2221 Enable support for the ARM64 ACPI parking protocol. If disabled 2222 the kernel will not allow booting through the ARM64 ACPI parking 2223 protocol even if the corresponding data is present in the ACPI 2224 MADT table. 2225 2226config CMDLINE 2227 string "Default kernel command string" 2228 default "" 2229 help 2230 Provide a set of default command-line options at build time by 2231 entering them here. As a minimum, you should specify the the 2232 root device (e.g. root=/dev/nfs). 2233 2234choice 2235 prompt "Kernel command line type" if CMDLINE != "" 2236 default CMDLINE_FROM_BOOTLOADER 2237 help 2238 Choose how the kernel will handle the provided default kernel 2239 command line string. 2240 2241config CMDLINE_FROM_BOOTLOADER 2242 bool "Use bootloader kernel arguments if available" 2243 help 2244 Uses the command-line options passed by the boot loader. If 2245 the boot loader doesn't provide any, the default kernel command 2246 string provided in CMDLINE will be used. 2247 2248config CMDLINE_FORCE 2249 bool "Always use the default kernel command string" 2250 help 2251 Always use the default kernel command string, even if the boot 2252 loader passes other arguments to the kernel. 2253 This is useful if you cannot or don't want to change the 2254 command-line options your boot loader passes to the kernel. 2255 2256endchoice 2257 2258config EFI_STUB 2259 bool 2260 2261config EFI 2262 bool "UEFI runtime support" 2263 depends on OF && !CPU_BIG_ENDIAN 2264 depends on KERNEL_MODE_NEON 2265 select ARCH_SUPPORTS_ACPI 2266 select LIBFDT 2267 select UCS2_STRING 2268 select EFI_PARAMS_FROM_FDT 2269 select EFI_RUNTIME_WRAPPERS 2270 select EFI_STUB 2271 select EFI_GENERIC_STUB 2272 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2273 default y 2274 help 2275 This option provides support for runtime services provided 2276 by UEFI firmware (such as non-volatile variables, realtime 2277 clock, and platform reset). A UEFI stub is also provided to 2278 allow the kernel to be booted as an EFI application. This 2279 is only useful on systems that have UEFI firmware. 2280 2281config DMI 2282 bool "Enable support for SMBIOS (DMI) tables" 2283 depends on EFI 2284 default y 2285 help 2286 This enables SMBIOS/DMI feature for systems. 2287 2288 This option is only useful on systems that have UEFI firmware. 2289 However, even with this option, the resultant kernel should 2290 continue to boot on existing non-UEFI platforms. 2291 2292endmenu # "Boot options" 2293 2294menu "Power management options" 2295 2296source "kernel/power/Kconfig" 2297 2298config ARCH_HIBERNATION_POSSIBLE 2299 def_bool y 2300 depends on CPU_PM 2301 2302config ARCH_HIBERNATION_HEADER 2303 def_bool y 2304 depends on HIBERNATION 2305 2306config ARCH_SUSPEND_POSSIBLE 2307 def_bool y 2308 2309endmenu # "Power management options" 2310 2311menu "CPU Power Management" 2312 2313source "drivers/cpuidle/Kconfig" 2314 2315source "drivers/cpufreq/Kconfig" 2316 2317endmenu # "CPU Power Management" 2318 2319source "drivers/acpi/Kconfig" 2320 2321source "arch/arm64/kvm/Kconfig" 2322 2323