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_DEVICES 137 select GENERIC_CPU_VULNERABILITIES 138 select GENERIC_EARLY_IOREMAP 139 select GENERIC_IDLE_POLL_SETUP 140 select GENERIC_IOREMAP 141 select GENERIC_IRQ_IPI 142 select GENERIC_IRQ_PROBE 143 select GENERIC_IRQ_SHOW 144 select GENERIC_IRQ_SHOW_LEVEL 145 select GENERIC_LIB_DEVMEM_IS_ALLOWED 146 select GENERIC_PCI_IOMAP 147 select GENERIC_PTDUMP 148 select GENERIC_SCHED_CLOCK 149 select GENERIC_SMP_IDLE_THREAD 150 select GENERIC_TIME_VSYSCALL 151 select GENERIC_GETTIMEOFDAY 152 select GENERIC_VDSO_TIME_NS 153 select HARDIRQS_SW_RESEND 154 select HAS_IOPORT 155 select HAVE_MOVE_PMD 156 select HAVE_MOVE_PUD 157 select HAVE_PCI 158 select HAVE_ACPI_APEI if (ACPI && EFI) 159 select HAVE_ALIGNED_STRUCT_PAGE 160 select HAVE_ARCH_AUDITSYSCALL 161 select HAVE_ARCH_BITREVERSE 162 select HAVE_ARCH_COMPILER_H 163 select HAVE_ARCH_HUGE_VMALLOC 164 select HAVE_ARCH_HUGE_VMAP 165 select HAVE_ARCH_JUMP_LABEL 166 select HAVE_ARCH_JUMP_LABEL_RELATIVE 167 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 168 select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 169 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 170 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 171 # Some instrumentation may be unsound, hence EXPERT 172 select HAVE_ARCH_KCSAN if EXPERT 173 select HAVE_ARCH_KFENCE 174 select HAVE_ARCH_KGDB 175 select HAVE_ARCH_MMAP_RND_BITS 176 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 177 select HAVE_ARCH_PREL32_RELOCATIONS 178 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 179 select HAVE_ARCH_SECCOMP_FILTER 180 select HAVE_ARCH_STACKLEAK 181 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 182 select HAVE_ARCH_TRACEHOOK 183 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 184 select HAVE_ARCH_VMAP_STACK 185 select HAVE_ARM_SMCCC 186 select HAVE_ASM_MODVERSIONS 187 select HAVE_EBPF_JIT 188 select HAVE_C_RECORDMCOUNT 189 select HAVE_CMPXCHG_DOUBLE 190 select HAVE_CMPXCHG_LOCAL 191 select HAVE_CONTEXT_TRACKING_USER 192 select HAVE_DEBUG_KMEMLEAK 193 select HAVE_DMA_CONTIGUOUS 194 select HAVE_DYNAMIC_FTRACE 195 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 196 if $(cc-option,-fpatchable-function-entry=2) 197 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 198 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 199 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 200 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 201 !CC_OPTIMIZE_FOR_SIZE) 202 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 203 if DYNAMIC_FTRACE_WITH_ARGS 204 select HAVE_SAMPLE_FTRACE_DIRECT 205 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 206 select HAVE_EFFICIENT_UNALIGNED_ACCESS 207 select HAVE_FAST_GUP 208 select HAVE_FTRACE_MCOUNT_RECORD 209 select HAVE_FUNCTION_TRACER 210 select HAVE_FUNCTION_ERROR_INJECTION 211 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 212 select HAVE_FUNCTION_GRAPH_TRACER 213 select HAVE_GCC_PLUGINS 214 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 215 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 216 select HAVE_HW_BREAKPOINT if PERF_EVENTS 217 select HAVE_IOREMAP_PROT 218 select HAVE_IRQ_TIME_ACCOUNTING 219 select HAVE_KVM 220 select HAVE_MOD_ARCH_SPECIFIC 221 select HAVE_NMI 222 select HAVE_PERF_EVENTS 223 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 224 select HAVE_PERF_REGS 225 select HAVE_PERF_USER_STACK_DUMP 226 select HAVE_PREEMPT_DYNAMIC_KEY 227 select HAVE_REGS_AND_STACK_ACCESS_API 228 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 229 select HAVE_FUNCTION_ARG_ACCESS_API 230 select MMU_GATHER_RCU_TABLE_FREE 231 select HAVE_RSEQ 232 select HAVE_STACKPROTECTOR 233 select HAVE_SYSCALL_TRACEPOINTS 234 select HAVE_KPROBES 235 select HAVE_KRETPROBES 236 select HAVE_GENERIC_VDSO 237 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 238 select IRQ_DOMAIN 239 select IRQ_FORCED_THREADING 240 select KASAN_VMALLOC if KASAN 241 select LOCK_MM_AND_FIND_VMA 242 select MODULES_USE_ELF_RELA 243 select NEED_DMA_MAP_STATE 244 select NEED_SG_DMA_LENGTH 245 select OF 246 select OF_EARLY_FLATTREE 247 select PCI_DOMAINS_GENERIC if PCI 248 select PCI_ECAM if (ACPI && PCI) 249 select PCI_SYSCALL if PCI 250 select POWER_RESET 251 select POWER_SUPPLY 252 select SPARSE_IRQ 253 select SWIOTLB 254 select SYSCTL_EXCEPTION_TRACE 255 select THREAD_INFO_IN_TASK 256 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 257 select TRACE_IRQFLAGS_SUPPORT 258 select TRACE_IRQFLAGS_NMI_SUPPORT 259 select HAVE_SOFTIRQ_ON_OWN_STACK 260 help 261 ARM 64-bit (AArch64) Linux support. 262 263config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 264 def_bool CC_IS_CLANG 265 # https://github.com/ClangBuiltLinux/linux/issues/1507 266 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 267 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 268 269config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 270 def_bool CC_IS_GCC 271 depends on $(cc-option,-fpatchable-function-entry=2) 272 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 273 274config 64BIT 275 def_bool y 276 277config MMU 278 def_bool y 279 280config ARM64_PAGE_SHIFT 281 int 282 default 16 if ARM64_64K_PAGES 283 default 14 if ARM64_16K_PAGES 284 default 12 285 286config ARM64_CONT_PTE_SHIFT 287 int 288 default 5 if ARM64_64K_PAGES 289 default 7 if ARM64_16K_PAGES 290 default 4 291 292config ARM64_CONT_PMD_SHIFT 293 int 294 default 5 if ARM64_64K_PAGES 295 default 5 if ARM64_16K_PAGES 296 default 4 297 298config ARCH_MMAP_RND_BITS_MIN 299 default 14 if ARM64_64K_PAGES 300 default 16 if ARM64_16K_PAGES 301 default 18 302 303# max bits determined by the following formula: 304# VA_BITS - PAGE_SHIFT - 3 305config ARCH_MMAP_RND_BITS_MAX 306 default 19 if ARM64_VA_BITS=36 307 default 24 if ARM64_VA_BITS=39 308 default 27 if ARM64_VA_BITS=42 309 default 30 if ARM64_VA_BITS=47 310 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 311 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 312 default 33 if ARM64_VA_BITS=48 313 default 14 if ARM64_64K_PAGES 314 default 16 if ARM64_16K_PAGES 315 default 18 316 317config ARCH_MMAP_RND_COMPAT_BITS_MIN 318 default 7 if ARM64_64K_PAGES 319 default 9 if ARM64_16K_PAGES 320 default 11 321 322config ARCH_MMAP_RND_COMPAT_BITS_MAX 323 default 16 324 325config NO_IOPORT_MAP 326 def_bool y if !PCI 327 328config STACKTRACE_SUPPORT 329 def_bool y 330 331config ILLEGAL_POINTER_VALUE 332 hex 333 default 0xdead000000000000 334 335config LOCKDEP_SUPPORT 336 def_bool y 337 338config GENERIC_BUG 339 def_bool y 340 depends on BUG 341 342config GENERIC_BUG_RELATIVE_POINTERS 343 def_bool y 344 depends on GENERIC_BUG 345 346config GENERIC_HWEIGHT 347 def_bool y 348 349config GENERIC_CSUM 350 def_bool y 351 352config GENERIC_CALIBRATE_DELAY 353 def_bool y 354 355config SMP 356 def_bool y 357 358config KERNEL_MODE_NEON 359 def_bool y 360 361config FIX_EARLYCON_MEM 362 def_bool y 363 364config PGTABLE_LEVELS 365 int 366 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 367 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 368 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 369 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 370 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 371 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 372 373config ARCH_SUPPORTS_UPROBES 374 def_bool y 375 376config ARCH_PROC_KCORE_TEXT 377 def_bool y 378 379config BROKEN_GAS_INST 380 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 381 382config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 383 bool 384 # Clang's __builtin_return_adddress() strips the PAC since 12.0.0 385 # https://reviews.llvm.org/D75044 386 default y if CC_IS_CLANG && (CLANG_VERSION >= 120000) 387 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 388 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 389 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 390 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 391 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 392 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 393 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 394 default n 395 396config KASAN_SHADOW_OFFSET 397 hex 398 depends on KASAN_GENERIC || KASAN_SW_TAGS 399 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 400 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 401 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 402 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 403 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 404 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 405 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 406 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 407 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 408 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 409 default 0xffffffffffffffff 410 411config UNWIND_TABLES 412 bool 413 414source "arch/arm64/Kconfig.platforms" 415 416menu "Kernel Features" 417 418menu "ARM errata workarounds via the alternatives framework" 419 420config AMPERE_ERRATUM_AC03_CPU_38 421 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 422 default y 423 help 424 This option adds an alternative code sequence to work around Ampere 425 erratum AC03_CPU_38 on AmpereOne. 426 427 The affected design reports FEAT_HAFDBS as not implemented in 428 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 429 as required by the architecture. The unadvertised HAFDBS 430 implementation suffers from an additional erratum where hardware 431 A/D updates can occur after a PTE has been marked invalid. 432 433 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 434 which avoids enabling unadvertised hardware Access Flag management 435 at stage-2. 436 437 If unsure, say Y. 438 439config ARM64_WORKAROUND_CLEAN_CACHE 440 bool 441 442config ARM64_ERRATUM_826319 443 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 444 default y 445 select ARM64_WORKAROUND_CLEAN_CACHE 446 help 447 This option adds an alternative code sequence to work around ARM 448 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 449 AXI master interface and an L2 cache. 450 451 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 452 and is unable to accept a certain write via this interface, it will 453 not progress on read data presented on the read data channel and the 454 system can deadlock. 455 456 The workaround promotes data cache clean instructions to 457 data cache clean-and-invalidate. 458 Please note that this does not necessarily enable the workaround, 459 as it depends on the alternative framework, which will only patch 460 the kernel if an affected CPU is detected. 461 462 If unsure, say Y. 463 464config ARM64_ERRATUM_827319 465 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 466 default y 467 select ARM64_WORKAROUND_CLEAN_CACHE 468 help 469 This option adds an alternative code sequence to work around ARM 470 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 471 master interface and an L2 cache. 472 473 Under certain conditions this erratum can cause a clean line eviction 474 to occur at the same time as another transaction to the same address 475 on the AMBA 5 CHI interface, which can cause data corruption if the 476 interconnect reorders the two transactions. 477 478 The workaround promotes data cache clean instructions to 479 data cache clean-and-invalidate. 480 Please note that this does not necessarily enable the workaround, 481 as it depends on the alternative framework, which will only patch 482 the kernel if an affected CPU is detected. 483 484 If unsure, say Y. 485 486config ARM64_ERRATUM_824069 487 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 488 default y 489 select ARM64_WORKAROUND_CLEAN_CACHE 490 help 491 This option adds an alternative code sequence to work around ARM 492 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 493 to a coherent interconnect. 494 495 If a Cortex-A53 processor is executing a store or prefetch for 496 write instruction at the same time as a processor in another 497 cluster is executing a cache maintenance operation to the same 498 address, then this erratum might cause a clean cache line to be 499 incorrectly marked as dirty. 500 501 The workaround promotes data cache clean instructions to 502 data cache clean-and-invalidate. 503 Please note that this option does not necessarily enable the 504 workaround, as it depends on the alternative framework, which will 505 only patch the kernel if an affected CPU is detected. 506 507 If unsure, say Y. 508 509config ARM64_ERRATUM_819472 510 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 511 default y 512 select ARM64_WORKAROUND_CLEAN_CACHE 513 help 514 This option adds an alternative code sequence to work around ARM 515 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 516 present when it is connected to a coherent interconnect. 517 518 If the processor is executing a load and store exclusive sequence at 519 the same time as a processor in another cluster is executing a cache 520 maintenance operation to the same address, then this erratum might 521 cause data corruption. 522 523 The workaround promotes data cache clean instructions to 524 data cache clean-and-invalidate. 525 Please note that this does not necessarily enable the workaround, 526 as it depends on the alternative framework, which will only patch 527 the kernel if an affected CPU is detected. 528 529 If unsure, say Y. 530 531config ARM64_ERRATUM_832075 532 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 533 default y 534 help 535 This option adds an alternative code sequence to work around ARM 536 erratum 832075 on Cortex-A57 parts up to r1p2. 537 538 Affected Cortex-A57 parts might deadlock when exclusive load/store 539 instructions to Write-Back memory are mixed with Device loads. 540 541 The workaround is to promote device loads to use Load-Acquire 542 semantics. 543 Please note that this does not necessarily enable the workaround, 544 as it depends on the alternative framework, which will only patch 545 the kernel if an affected CPU is detected. 546 547 If unsure, say Y. 548 549config ARM64_ERRATUM_834220 550 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 551 depends on KVM 552 default y 553 help 554 This option adds an alternative code sequence to work around ARM 555 erratum 834220 on Cortex-A57 parts up to r1p2. 556 557 Affected Cortex-A57 parts might report a Stage 2 translation 558 fault as the result of a Stage 1 fault for load crossing a 559 page boundary when there is a permission or device memory 560 alignment fault at Stage 1 and a translation fault at Stage 2. 561 562 The workaround is to verify that the Stage 1 translation 563 doesn't generate a fault before handling the Stage 2 fault. 564 Please note that this does not necessarily enable the workaround, 565 as it depends on the alternative framework, which will only patch 566 the kernel if an affected CPU is detected. 567 568 If unsure, say Y. 569 570config ARM64_ERRATUM_1742098 571 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 572 depends on COMPAT 573 default y 574 help 575 This option removes the AES hwcap for aarch32 user-space to 576 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 577 578 Affected parts may corrupt the AES state if an interrupt is 579 taken between a pair of AES instructions. These instructions 580 are only present if the cryptography extensions are present. 581 All software should have a fallback implementation for CPUs 582 that don't implement the cryptography extensions. 583 584 If unsure, say Y. 585 586config ARM64_ERRATUM_845719 587 bool "Cortex-A53: 845719: a load might read incorrect data" 588 depends on COMPAT 589 default y 590 help 591 This option adds an alternative code sequence to work around ARM 592 erratum 845719 on Cortex-A53 parts up to r0p4. 593 594 When running a compat (AArch32) userspace on an affected Cortex-A53 595 part, a load at EL0 from a virtual address that matches the bottom 32 596 bits of the virtual address used by a recent load at (AArch64) EL1 597 might return incorrect data. 598 599 The workaround is to write the contextidr_el1 register on exception 600 return to a 32-bit task. 601 Please note that this does not necessarily enable the workaround, 602 as it depends on the alternative framework, which will only patch 603 the kernel if an affected CPU is detected. 604 605 If unsure, say Y. 606 607config ARM64_ERRATUM_843419 608 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 609 default y 610 help 611 This option links the kernel with '--fix-cortex-a53-843419' and 612 enables PLT support to replace certain ADRP instructions, which can 613 cause subsequent memory accesses to use an incorrect address on 614 Cortex-A53 parts up to r0p4. 615 616 If unsure, say Y. 617 618config ARM64_LD_HAS_FIX_ERRATUM_843419 619 def_bool $(ld-option,--fix-cortex-a53-843419) 620 621config ARM64_ERRATUM_1024718 622 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 623 default y 624 help 625 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 626 627 Affected Cortex-A55 cores (all revisions) could cause incorrect 628 update of the hardware dirty bit when the DBM/AP bits are updated 629 without a break-before-make. The workaround is to disable the usage 630 of hardware DBM locally on the affected cores. CPUs not affected by 631 this erratum will continue to use the feature. 632 633 If unsure, say Y. 634 635config ARM64_ERRATUM_1418040 636 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 637 default y 638 depends on COMPAT 639 help 640 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 641 errata 1188873 and 1418040. 642 643 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 644 cause register corruption when accessing the timer registers 645 from AArch32 userspace. 646 647 If unsure, say Y. 648 649config ARM64_WORKAROUND_SPECULATIVE_AT 650 bool 651 652config ARM64_ERRATUM_1165522 653 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 654 default y 655 select ARM64_WORKAROUND_SPECULATIVE_AT 656 help 657 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 658 659 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 660 corrupted TLBs by speculating an AT instruction during a guest 661 context switch. 662 663 If unsure, say Y. 664 665config ARM64_ERRATUM_1319367 666 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 667 default y 668 select ARM64_WORKAROUND_SPECULATIVE_AT 669 help 670 This option adds work arounds for ARM Cortex-A57 erratum 1319537 671 and A72 erratum 1319367 672 673 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 674 speculating an AT instruction during a guest context switch. 675 676 If unsure, say Y. 677 678config ARM64_ERRATUM_1530923 679 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 680 default y 681 select ARM64_WORKAROUND_SPECULATIVE_AT 682 help 683 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 684 685 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 686 corrupted TLBs by speculating an AT instruction during a guest 687 context switch. 688 689 If unsure, say Y. 690 691config ARM64_WORKAROUND_REPEAT_TLBI 692 bool 693 694config ARM64_ERRATUM_2441007 695 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 696 default y 697 select ARM64_WORKAROUND_REPEAT_TLBI 698 help 699 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 700 701 Under very rare circumstances, affected Cortex-A55 CPUs 702 may not handle a race between a break-before-make sequence on one 703 CPU, and another CPU accessing the same page. This could allow a 704 store to a page that has been unmapped. 705 706 Work around this by adding the affected CPUs to the list that needs 707 TLB sequences to be done twice. 708 709 If unsure, say Y. 710 711config ARM64_ERRATUM_1286807 712 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 713 default y 714 select ARM64_WORKAROUND_REPEAT_TLBI 715 help 716 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 717 718 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 719 address for a cacheable mapping of a location is being 720 accessed by a core while another core is remapping the virtual 721 address to a new physical page using the recommended 722 break-before-make sequence, then under very rare circumstances 723 TLBI+DSB completes before a read using the translation being 724 invalidated has been observed by other observers. The 725 workaround repeats the TLBI+DSB operation. 726 727config ARM64_ERRATUM_1463225 728 bool "Cortex-A76: Software Step might prevent interrupt recognition" 729 default y 730 help 731 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 732 733 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 734 of a system call instruction (SVC) can prevent recognition of 735 subsequent interrupts when software stepping is disabled in the 736 exception handler of the system call and either kernel debugging 737 is enabled or VHE is in use. 738 739 Work around the erratum by triggering a dummy step exception 740 when handling a system call from a task that is being stepped 741 in a VHE configuration of the kernel. 742 743 If unsure, say Y. 744 745config ARM64_ERRATUM_1542419 746 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 747 default y 748 help 749 This option adds a workaround for ARM Neoverse-N1 erratum 750 1542419. 751 752 Affected Neoverse-N1 cores could execute a stale instruction when 753 modified by another CPU. The workaround depends on a firmware 754 counterpart. 755 756 Workaround the issue by hiding the DIC feature from EL0. This 757 forces user-space to perform cache maintenance. 758 759 If unsure, say Y. 760 761config ARM64_ERRATUM_1508412 762 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 763 default y 764 help 765 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 766 767 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 768 of a store-exclusive or read of PAR_EL1 and a load with device or 769 non-cacheable memory attributes. The workaround depends on a firmware 770 counterpart. 771 772 KVM guests must also have the workaround implemented or they can 773 deadlock the system. 774 775 Work around the issue by inserting DMB SY barriers around PAR_EL1 776 register reads and warning KVM users. The DMB barrier is sufficient 777 to prevent a speculative PAR_EL1 read. 778 779 If unsure, say Y. 780 781config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 782 bool 783 784config ARM64_ERRATUM_2051678 785 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 786 default y 787 help 788 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 789 Affected Cortex-A510 might not respect the ordering rules for 790 hardware update of the page table's dirty bit. The workaround 791 is to not enable the feature on affected CPUs. 792 793 If unsure, say Y. 794 795config ARM64_ERRATUM_2077057 796 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 797 default y 798 help 799 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 800 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 801 expected, but a Pointer Authentication trap is taken instead. The 802 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 803 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 804 805 This can only happen when EL2 is stepping EL1. 806 807 When these conditions occur, the SPSR_EL2 value is unchanged from the 808 previous guest entry, and can be restored from the in-memory copy. 809 810 If unsure, say Y. 811 812config ARM64_ERRATUM_2658417 813 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 814 default y 815 help 816 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 817 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 818 BFMMLA or VMMLA instructions in rare circumstances when a pair of 819 A510 CPUs are using shared neon hardware. As the sharing is not 820 discoverable by the kernel, hide the BF16 HWCAP to indicate that 821 user-space should not be using these instructions. 822 823 If unsure, say Y. 824 825config ARM64_ERRATUM_2119858 826 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 827 default y 828 depends on CORESIGHT_TRBE 829 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 830 help 831 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 832 833 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 834 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 835 the event of a WRAP event. 836 837 Work around the issue by always making sure we move the TRBPTR_EL1 by 838 256 bytes before enabling the buffer and filling the first 256 bytes of 839 the buffer with ETM ignore packets upon disabling. 840 841 If unsure, say Y. 842 843config ARM64_ERRATUM_2139208 844 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 845 default y 846 depends on CORESIGHT_TRBE 847 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 848 help 849 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 850 851 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 852 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 853 the event of a WRAP event. 854 855 Work around the issue by always making sure we move the TRBPTR_EL1 by 856 256 bytes before enabling the buffer and filling the first 256 bytes of 857 the buffer with ETM ignore packets upon disabling. 858 859 If unsure, say Y. 860 861config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 862 bool 863 864config ARM64_ERRATUM_2054223 865 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 866 default y 867 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 868 help 869 Enable workaround for ARM Cortex-A710 erratum 2054223 870 871 Affected cores may fail to flush the trace data on a TSB instruction, when 872 the PE is in trace prohibited state. This will cause losing a few bytes 873 of the trace cached. 874 875 Workaround is to issue two TSB consecutively on affected cores. 876 877 If unsure, say Y. 878 879config ARM64_ERRATUM_2067961 880 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 881 default y 882 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 883 help 884 Enable workaround for ARM Neoverse-N2 erratum 2067961 885 886 Affected cores may fail to flush the trace data on a TSB instruction, when 887 the PE is in trace prohibited state. This will cause losing a few bytes 888 of the trace cached. 889 890 Workaround is to issue two TSB consecutively on affected cores. 891 892 If unsure, say Y. 893 894config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 895 bool 896 897config ARM64_ERRATUM_2253138 898 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 899 depends on CORESIGHT_TRBE 900 default y 901 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 902 help 903 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 904 905 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 906 for TRBE. Under some conditions, the TRBE might generate a write to the next 907 virtually addressed page following the last page of the TRBE address space 908 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 909 910 Work around this in the driver by always making sure that there is a 911 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 912 913 If unsure, say Y. 914 915config ARM64_ERRATUM_2224489 916 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 917 depends on CORESIGHT_TRBE 918 default y 919 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 920 help 921 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 922 923 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 924 for TRBE. Under some conditions, the TRBE might generate a write to the next 925 virtually addressed page following the last page of the TRBE address space 926 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 927 928 Work around this in the driver by always making sure that there is a 929 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 930 931 If unsure, say Y. 932 933config ARM64_ERRATUM_2441009 934 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" 935 default y 936 select ARM64_WORKAROUND_REPEAT_TLBI 937 help 938 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 939 940 Under very rare circumstances, affected Cortex-A510 CPUs 941 may not handle a race between a break-before-make sequence on one 942 CPU, and another CPU accessing the same page. This could allow a 943 store to a page that has been unmapped. 944 945 Work around this by adding the affected CPUs to the list that needs 946 TLB sequences to be done twice. 947 948 If unsure, say Y. 949 950config ARM64_ERRATUM_2064142 951 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 952 depends on CORESIGHT_TRBE 953 default y 954 help 955 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 956 957 Affected Cortex-A510 core might fail to write into system registers after the 958 TRBE has been disabled. Under some conditions after the TRBE has been disabled 959 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 960 and TRBTRG_EL1 will be ignored and will not be effected. 961 962 Work around this in the driver by executing TSB CSYNC and DSB after collection 963 is stopped and before performing a system register write to one of the affected 964 registers. 965 966 If unsure, say Y. 967 968config ARM64_ERRATUM_2038923 969 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 970 depends on CORESIGHT_TRBE 971 default y 972 help 973 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 974 975 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 976 prohibited within the CPU. As a result, the trace buffer or trace buffer state 977 might be corrupted. This happens after TRBE buffer has been enabled by setting 978 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 979 execution changes from a context, in which trace is prohibited to one where it 980 isn't, or vice versa. In these mentioned conditions, the view of whether trace 981 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 982 the trace buffer state might be corrupted. 983 984 Work around this in the driver by preventing an inconsistent view of whether the 985 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 986 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 987 two ISB instructions if no ERET is to take place. 988 989 If unsure, say Y. 990 991config ARM64_ERRATUM_1902691 992 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 993 depends on CORESIGHT_TRBE 994 default y 995 help 996 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 997 998 Affected Cortex-A510 core might cause trace data corruption, when being written 999 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1000 trace data. 1001 1002 Work around this problem in the driver by just preventing TRBE initialization on 1003 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1004 on such implementations. This will cover the kernel for any firmware that doesn't 1005 do this already. 1006 1007 If unsure, say Y. 1008 1009config ARM64_ERRATUM_2457168 1010 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1011 depends on ARM64_AMU_EXTN 1012 default y 1013 help 1014 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1015 1016 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1017 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1018 incorrectly giving a significantly higher output value. 1019 1020 Work around this problem by returning 0 when reading the affected counter in 1021 key locations that results in disabling all users of this counter. This effect 1022 is the same to firmware disabling affected counters. 1023 1024 If unsure, say Y. 1025 1026config ARM64_ERRATUM_2645198 1027 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1028 default y 1029 help 1030 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1031 1032 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1033 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1034 next instruction abort caused by permission fault. 1035 1036 Only user-space does executable to non-executable permission transition via 1037 mprotect() system call. Workaround the problem by doing a break-before-make 1038 TLB invalidation, for all changes to executable user space mappings. 1039 1040 If unsure, say Y. 1041 1042config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1043 bool 1044 1045config ARM64_ERRATUM_2966298 1046 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1047 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1048 default y 1049 help 1050 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1051 1052 On an affected Cortex-A520 core, a speculatively executed unprivileged 1053 load might leak data from a privileged level via a cache side channel. 1054 1055 Work around this problem by executing a TLBI before returning to EL0. 1056 1057 If unsure, say Y. 1058 1059config ARM64_ERRATUM_3117295 1060 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1061 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1062 default y 1063 help 1064 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1065 1066 On an affected Cortex-A510 core, a speculatively executed unprivileged 1067 load might leak data from a privileged level via a cache side channel. 1068 1069 Work around this problem by executing a TLBI before returning to EL0. 1070 1071 If unsure, say Y. 1072 1073config CAVIUM_ERRATUM_22375 1074 bool "Cavium erratum 22375, 24313" 1075 default y 1076 help 1077 Enable workaround for errata 22375 and 24313. 1078 1079 This implements two gicv3-its errata workarounds for ThunderX. Both 1080 with a small impact affecting only ITS table allocation. 1081 1082 erratum 22375: only alloc 8MB table size 1083 erratum 24313: ignore memory access type 1084 1085 The fixes are in ITS initialization and basically ignore memory access 1086 type and table size provided by the TYPER and BASER registers. 1087 1088 If unsure, say Y. 1089 1090config CAVIUM_ERRATUM_23144 1091 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1092 depends on NUMA 1093 default y 1094 help 1095 ITS SYNC command hang for cross node io and collections/cpu mapping. 1096 1097 If unsure, say Y. 1098 1099config CAVIUM_ERRATUM_23154 1100 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1101 default y 1102 help 1103 The ThunderX GICv3 implementation requires a modified version for 1104 reading the IAR status to ensure data synchronization 1105 (access to icc_iar1_el1 is not sync'ed before and after). 1106 1107 It also suffers from erratum 38545 (also present on Marvell's 1108 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1109 spuriously presented to the CPU interface. 1110 1111 If unsure, say Y. 1112 1113config CAVIUM_ERRATUM_27456 1114 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1115 default y 1116 help 1117 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1118 instructions may cause the icache to become corrupted if it 1119 contains data for a non-current ASID. The fix is to 1120 invalidate the icache when changing the mm context. 1121 1122 If unsure, say Y. 1123 1124config CAVIUM_ERRATUM_30115 1125 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1126 default y 1127 help 1128 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1129 1.2, and T83 Pass 1.0, KVM guest execution may disable 1130 interrupts in host. Trapping both GICv3 group-0 and group-1 1131 accesses sidesteps the issue. 1132 1133 If unsure, say Y. 1134 1135config CAVIUM_TX2_ERRATUM_219 1136 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1137 default y 1138 help 1139 On Cavium ThunderX2, a load, store or prefetch instruction between a 1140 TTBR update and the corresponding context synchronizing operation can 1141 cause a spurious Data Abort to be delivered to any hardware thread in 1142 the CPU core. 1143 1144 Work around the issue by avoiding the problematic code sequence and 1145 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1146 trap handler performs the corresponding register access, skips the 1147 instruction and ensures context synchronization by virtue of the 1148 exception return. 1149 1150 If unsure, say Y. 1151 1152config FUJITSU_ERRATUM_010001 1153 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1154 default y 1155 help 1156 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1157 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1158 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1159 This fault occurs under a specific hardware condition when a 1160 load/store instruction performs an address translation using: 1161 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1162 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1163 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1164 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1165 1166 The workaround is to ensure these bits are clear in TCR_ELx. 1167 The workaround only affects the Fujitsu-A64FX. 1168 1169 If unsure, say Y. 1170 1171config HISILICON_ERRATUM_161600802 1172 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1173 default y 1174 help 1175 The HiSilicon Hip07 SoC uses the wrong redistributor base 1176 when issued ITS commands such as VMOVP and VMAPP, and requires 1177 a 128kB offset to be applied to the target address in this commands. 1178 1179 If unsure, say Y. 1180 1181config QCOM_FALKOR_ERRATUM_1003 1182 bool "Falkor E1003: Incorrect translation due to ASID change" 1183 default y 1184 help 1185 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1186 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1187 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1188 then only for entries in the walk cache, since the leaf translation 1189 is unchanged. Work around the erratum by invalidating the walk cache 1190 entries for the trampoline before entering the kernel proper. 1191 1192config QCOM_FALKOR_ERRATUM_1009 1193 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1194 default y 1195 select ARM64_WORKAROUND_REPEAT_TLBI 1196 help 1197 On Falkor v1, the CPU may prematurely complete a DSB following a 1198 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1199 one more time to fix the issue. 1200 1201 If unsure, say Y. 1202 1203config QCOM_QDF2400_ERRATUM_0065 1204 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1205 default y 1206 help 1207 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1208 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1209 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1210 1211 If unsure, say Y. 1212 1213config QCOM_FALKOR_ERRATUM_E1041 1214 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1215 default y 1216 help 1217 Falkor CPU may speculatively fetch instructions from an improper 1218 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1219 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1220 1221 If unsure, say Y. 1222 1223config NVIDIA_CARMEL_CNP_ERRATUM 1224 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1225 default y 1226 help 1227 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1228 invalidate shared TLB entries installed by a different core, as it would 1229 on standard ARM cores. 1230 1231 If unsure, say Y. 1232 1233config ROCKCHIP_ERRATUM_3588001 1234 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1235 default y 1236 help 1237 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1238 This means, that its sharability feature may not be used, even though it 1239 is supported by the IP itself. 1240 1241 If unsure, say Y. 1242 1243config SOCIONEXT_SYNQUACER_PREITS 1244 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1245 default y 1246 help 1247 Socionext Synquacer SoCs implement a separate h/w block to generate 1248 MSI doorbell writes with non-zero values for the device ID. 1249 1250 If unsure, say Y. 1251 1252endmenu # "ARM errata workarounds via the alternatives framework" 1253 1254choice 1255 prompt "Page size" 1256 default ARM64_4K_PAGES 1257 help 1258 Page size (translation granule) configuration. 1259 1260config ARM64_4K_PAGES 1261 bool "4KB" 1262 help 1263 This feature enables 4KB pages support. 1264 1265config ARM64_16K_PAGES 1266 bool "16KB" 1267 help 1268 The system will use 16KB pages support. AArch32 emulation 1269 requires applications compiled with 16K (or a multiple of 16K) 1270 aligned segments. 1271 1272config ARM64_64K_PAGES 1273 bool "64KB" 1274 help 1275 This feature enables 64KB pages support (4KB by default) 1276 allowing only two levels of page tables and faster TLB 1277 look-up. AArch32 emulation requires applications compiled 1278 with 64K aligned segments. 1279 1280endchoice 1281 1282choice 1283 prompt "Virtual address space size" 1284 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 1285 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 1286 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 1287 help 1288 Allows choosing one of multiple possible virtual address 1289 space sizes. The level of translation table is determined by 1290 a combination of page size and virtual address space size. 1291 1292config ARM64_VA_BITS_36 1293 bool "36-bit" if EXPERT 1294 depends on ARM64_16K_PAGES 1295 1296config ARM64_VA_BITS_39 1297 bool "39-bit" 1298 depends on ARM64_4K_PAGES 1299 1300config ARM64_VA_BITS_42 1301 bool "42-bit" 1302 depends on ARM64_64K_PAGES 1303 1304config ARM64_VA_BITS_47 1305 bool "47-bit" 1306 depends on ARM64_16K_PAGES 1307 1308config ARM64_VA_BITS_48 1309 bool "48-bit" 1310 1311config ARM64_VA_BITS_52 1312 bool "52-bit" 1313 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 1314 help 1315 Enable 52-bit virtual addressing for userspace when explicitly 1316 requested via a hint to mmap(). The kernel will also use 52-bit 1317 virtual addresses for its own mappings (provided HW support for 1318 this feature is available, otherwise it reverts to 48-bit). 1319 1320 NOTE: Enabling 52-bit virtual addressing in conjunction with 1321 ARMv8.3 Pointer Authentication will result in the PAC being 1322 reduced from 7 bits to 3 bits, which may have a significant 1323 impact on its susceptibility to brute-force attacks. 1324 1325 If unsure, select 48-bit virtual addressing instead. 1326 1327endchoice 1328 1329config ARM64_FORCE_52BIT 1330 bool "Force 52-bit virtual addresses for userspace" 1331 depends on ARM64_VA_BITS_52 && EXPERT 1332 help 1333 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1334 to maintain compatibility with older software by providing 48-bit VAs 1335 unless a hint is supplied to mmap. 1336 1337 This configuration option disables the 48-bit compatibility logic, and 1338 forces all userspace addresses to be 52-bit on HW that supports it. One 1339 should only enable this configuration option for stress testing userspace 1340 memory management code. If unsure say N here. 1341 1342config ARM64_VA_BITS 1343 int 1344 default 36 if ARM64_VA_BITS_36 1345 default 39 if ARM64_VA_BITS_39 1346 default 42 if ARM64_VA_BITS_42 1347 default 47 if ARM64_VA_BITS_47 1348 default 48 if ARM64_VA_BITS_48 1349 default 52 if ARM64_VA_BITS_52 1350 1351choice 1352 prompt "Physical address space size" 1353 default ARM64_PA_BITS_48 1354 help 1355 Choose the maximum physical address range that the kernel will 1356 support. 1357 1358config ARM64_PA_BITS_48 1359 bool "48-bit" 1360 1361config ARM64_PA_BITS_52 1362 bool "52-bit (ARMv8.2)" 1363 depends on ARM64_64K_PAGES 1364 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1365 help 1366 Enable support for a 52-bit physical address space, introduced as 1367 part of the ARMv8.2-LPA extension. 1368 1369 With this enabled, the kernel will also continue to work on CPUs that 1370 do not support ARMv8.2-LPA, but with some added memory overhead (and 1371 minor performance overhead). 1372 1373endchoice 1374 1375config ARM64_PA_BITS 1376 int 1377 default 48 if ARM64_PA_BITS_48 1378 default 52 if ARM64_PA_BITS_52 1379 1380choice 1381 prompt "Endianness" 1382 default CPU_LITTLE_ENDIAN 1383 help 1384 Select the endianness of data accesses performed by the CPU. Userspace 1385 applications will need to be compiled and linked for the endianness 1386 that is selected here. 1387 1388config CPU_BIG_ENDIAN 1389 bool "Build big-endian kernel" 1390 depends on !LD_IS_LLD || LLD_VERSION >= 130000 1391 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1392 depends on AS_IS_GNU || AS_VERSION >= 150000 1393 help 1394 Say Y if you plan on running a kernel with a big-endian userspace. 1395 1396config CPU_LITTLE_ENDIAN 1397 bool "Build little-endian kernel" 1398 help 1399 Say Y if you plan on running a kernel with a little-endian userspace. 1400 This is usually the case for distributions targeting arm64. 1401 1402endchoice 1403 1404config SCHED_MC 1405 bool "Multi-core scheduler support" 1406 help 1407 Multi-core scheduler support improves the CPU scheduler's decision 1408 making when dealing with multi-core CPU chips at a cost of slightly 1409 increased overhead in some places. If unsure say N here. 1410 1411config SCHED_CLUSTER 1412 bool "Cluster scheduler support" 1413 help 1414 Cluster scheduler support improves the CPU scheduler's decision 1415 making when dealing with machines that have clusters of CPUs. 1416 Cluster usually means a couple of CPUs which are placed closely 1417 by sharing mid-level caches, last-level cache tags or internal 1418 busses. 1419 1420config SCHED_SMT 1421 bool "SMT scheduler support" 1422 help 1423 Improves the CPU scheduler's decision making when dealing with 1424 MultiThreading at a cost of slightly increased overhead in some 1425 places. If unsure say N here. 1426 1427config NR_CPUS 1428 int "Maximum number of CPUs (2-4096)" 1429 range 2 4096 1430 default "256" 1431 1432config HOTPLUG_CPU 1433 bool "Support for hot-pluggable CPUs" 1434 select GENERIC_IRQ_MIGRATION 1435 help 1436 Say Y here to experiment with turning CPUs off and on. CPUs 1437 can be controlled through /sys/devices/system/cpu. 1438 1439# Common NUMA Features 1440config NUMA 1441 bool "NUMA Memory Allocation and Scheduler Support" 1442 select GENERIC_ARCH_NUMA 1443 select ACPI_NUMA if ACPI 1444 select OF_NUMA 1445 select HAVE_SETUP_PER_CPU_AREA 1446 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1447 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1448 select USE_PERCPU_NUMA_NODE_ID 1449 help 1450 Enable NUMA (Non-Uniform Memory Access) support. 1451 1452 The kernel will try to allocate memory used by a CPU on the 1453 local memory of the CPU and add some more 1454 NUMA awareness to the kernel. 1455 1456config NODES_SHIFT 1457 int "Maximum NUMA Nodes (as a power of 2)" 1458 range 1 10 1459 default "4" 1460 depends on NUMA 1461 help 1462 Specify the maximum number of NUMA Nodes available on the target 1463 system. Increases memory reserved to accommodate various tables. 1464 1465source "kernel/Kconfig.hz" 1466 1467config ARCH_SPARSEMEM_ENABLE 1468 def_bool y 1469 select SPARSEMEM_VMEMMAP_ENABLE 1470 select SPARSEMEM_VMEMMAP 1471 1472config HW_PERF_EVENTS 1473 def_bool y 1474 depends on ARM_PMU 1475 1476# Supported by clang >= 7.0 or GCC >= 12.0.0 1477config CC_HAVE_SHADOW_CALL_STACK 1478 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1479 1480config PARAVIRT 1481 bool "Enable paravirtualization code" 1482 help 1483 This changes the kernel so it can modify itself when it is run 1484 under a hypervisor, potentially improving performance significantly 1485 over full virtualization. 1486 1487config PARAVIRT_TIME_ACCOUNTING 1488 bool "Paravirtual steal time accounting" 1489 select PARAVIRT 1490 help 1491 Select this option to enable fine granularity task steal time 1492 accounting. Time spent executing other tasks in parallel with 1493 the current vCPU is discounted from the vCPU power. To account for 1494 that, there can be a small performance impact. 1495 1496 If in doubt, say N here. 1497 1498config ARCH_SUPPORTS_KEXEC 1499 def_bool PM_SLEEP_SMP 1500 1501config ARCH_SUPPORTS_KEXEC_FILE 1502 def_bool y 1503 1504config ARCH_SELECTS_KEXEC_FILE 1505 def_bool y 1506 depends on KEXEC_FILE 1507 select HAVE_IMA_KEXEC if IMA 1508 1509config ARCH_SUPPORTS_KEXEC_SIG 1510 def_bool y 1511 1512config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1513 def_bool y 1514 1515config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1516 def_bool y 1517 1518config ARCH_SUPPORTS_CRASH_DUMP 1519 def_bool y 1520 1521config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1522 def_bool CRASH_CORE 1523 1524config TRANS_TABLE 1525 def_bool y 1526 depends on HIBERNATION || KEXEC_CORE 1527 1528config XEN_DOM0 1529 def_bool y 1530 depends on XEN 1531 1532config XEN 1533 bool "Xen guest support on ARM64" 1534 depends on ARM64 && OF 1535 select SWIOTLB_XEN 1536 select PARAVIRT 1537 help 1538 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1539 1540# include/linux/mmzone.h requires the following to be true: 1541# 1542# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1543# 1544# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1545# 1546# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1547# ----+-------------------+--------------+----------------------+-------------------------+ 1548# 4K | 27 | 12 | 15 | 10 | 1549# 16K | 27 | 14 | 13 | 11 | 1550# 64K | 29 | 16 | 13 | 13 | 1551config ARCH_FORCE_MAX_ORDER 1552 int 1553 default "13" if ARM64_64K_PAGES 1554 default "11" if ARM64_16K_PAGES 1555 default "10" 1556 help 1557 The kernel page allocator limits the size of maximal physically 1558 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1559 defines the maximal power of two of number of pages that can be 1560 allocated as a single contiguous block. This option allows 1561 overriding the default setting when ability to allocate very 1562 large blocks of physically contiguous memory is required. 1563 1564 The maximal size of allocation cannot exceed the size of the 1565 section, so the value of MAX_PAGE_ORDER should satisfy 1566 1567 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1568 1569 Don't change if unsure. 1570 1571config UNMAP_KERNEL_AT_EL0 1572 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1573 default y 1574 help 1575 Speculation attacks against some high-performance processors can 1576 be used to bypass MMU permission checks and leak kernel data to 1577 userspace. This can be defended against by unmapping the kernel 1578 when running in userspace, mapping it back in on exception entry 1579 via a trampoline page in the vector table. 1580 1581 If unsure, say Y. 1582 1583config MITIGATE_SPECTRE_BRANCH_HISTORY 1584 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1585 default y 1586 help 1587 Speculation attacks against some high-performance processors can 1588 make use of branch history to influence future speculation. 1589 When taking an exception from user-space, a sequence of branches 1590 or a firmware call overwrites the branch history. 1591 1592config RODATA_FULL_DEFAULT_ENABLED 1593 bool "Apply r/o permissions of VM areas also to their linear aliases" 1594 default y 1595 help 1596 Apply read-only attributes of VM areas to the linear alias of 1597 the backing pages as well. This prevents code or read-only data 1598 from being modified (inadvertently or intentionally) via another 1599 mapping of the same memory page. This additional enhancement can 1600 be turned off at runtime by passing rodata=[off|on] (and turned on 1601 with rodata=full if this option is set to 'n') 1602 1603 This requires the linear region to be mapped down to pages, 1604 which may adversely affect performance in some cases. 1605 1606config ARM64_SW_TTBR0_PAN 1607 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1608 help 1609 Enabling this option prevents the kernel from accessing 1610 user-space memory directly by pointing TTBR0_EL1 to a reserved 1611 zeroed area and reserved ASID. The user access routines 1612 restore the valid TTBR0_EL1 temporarily. 1613 1614config ARM64_TAGGED_ADDR_ABI 1615 bool "Enable the tagged user addresses syscall ABI" 1616 default y 1617 help 1618 When this option is enabled, user applications can opt in to a 1619 relaxed ABI via prctl() allowing tagged addresses to be passed 1620 to system calls as pointer arguments. For details, see 1621 Documentation/arch/arm64/tagged-address-abi.rst. 1622 1623menuconfig COMPAT 1624 bool "Kernel support for 32-bit EL0" 1625 depends on ARM64_4K_PAGES || EXPERT 1626 select HAVE_UID16 1627 select OLD_SIGSUSPEND3 1628 select COMPAT_OLD_SIGACTION 1629 help 1630 This option enables support for a 32-bit EL0 running under a 64-bit 1631 kernel at EL1. AArch32-specific components such as system calls, 1632 the user helper functions, VFP support and the ptrace interface are 1633 handled appropriately by the kernel. 1634 1635 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1636 that you will only be able to execute AArch32 binaries that were compiled 1637 with page size aligned segments. 1638 1639 If you want to execute 32-bit userspace applications, say Y. 1640 1641if COMPAT 1642 1643config KUSER_HELPERS 1644 bool "Enable kuser helpers page for 32-bit applications" 1645 default y 1646 help 1647 Warning: disabling this option may break 32-bit user programs. 1648 1649 Provide kuser helpers to compat tasks. The kernel provides 1650 helper code to userspace in read only form at a fixed location 1651 to allow userspace to be independent of the CPU type fitted to 1652 the system. This permits binaries to be run on ARMv4 through 1653 to ARMv8 without modification. 1654 1655 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1656 1657 However, the fixed address nature of these helpers can be used 1658 by ROP (return orientated programming) authors when creating 1659 exploits. 1660 1661 If all of the binaries and libraries which run on your platform 1662 are built specifically for your platform, and make no use of 1663 these helpers, then you can turn this option off to hinder 1664 such exploits. However, in that case, if a binary or library 1665 relying on those helpers is run, it will not function correctly. 1666 1667 Say N here only if you are absolutely certain that you do not 1668 need these helpers; otherwise, the safe option is to say Y. 1669 1670config COMPAT_VDSO 1671 bool "Enable vDSO for 32-bit applications" 1672 depends on !CPU_BIG_ENDIAN 1673 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1674 select GENERIC_COMPAT_VDSO 1675 default y 1676 help 1677 Place in the process address space of 32-bit applications an 1678 ELF shared object providing fast implementations of gettimeofday 1679 and clock_gettime. 1680 1681 You must have a 32-bit build of glibc 2.22 or later for programs 1682 to seamlessly take advantage of this. 1683 1684config THUMB2_COMPAT_VDSO 1685 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1686 depends on COMPAT_VDSO 1687 default y 1688 help 1689 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1690 otherwise with '-marm'. 1691 1692config COMPAT_ALIGNMENT_FIXUPS 1693 bool "Fix up misaligned multi-word loads and stores in user space" 1694 1695menuconfig ARMV8_DEPRECATED 1696 bool "Emulate deprecated/obsolete ARMv8 instructions" 1697 depends on SYSCTL 1698 help 1699 Legacy software support may require certain instructions 1700 that have been deprecated or obsoleted in the architecture. 1701 1702 Enable this config to enable selective emulation of these 1703 features. 1704 1705 If unsure, say Y 1706 1707if ARMV8_DEPRECATED 1708 1709config SWP_EMULATION 1710 bool "Emulate SWP/SWPB instructions" 1711 help 1712 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1713 they are always undefined. Say Y here to enable software 1714 emulation of these instructions for userspace using LDXR/STXR. 1715 This feature can be controlled at runtime with the abi.swp 1716 sysctl which is disabled by default. 1717 1718 In some older versions of glibc [<=2.8] SWP is used during futex 1719 trylock() operations with the assumption that the code will not 1720 be preempted. This invalid assumption may be more likely to fail 1721 with SWP emulation enabled, leading to deadlock of the user 1722 application. 1723 1724 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1725 on an external transaction monitoring block called a global 1726 monitor to maintain update atomicity. If your system does not 1727 implement a global monitor, this option can cause programs that 1728 perform SWP operations to uncached memory to deadlock. 1729 1730 If unsure, say Y 1731 1732config CP15_BARRIER_EMULATION 1733 bool "Emulate CP15 Barrier instructions" 1734 help 1735 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1736 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1737 strongly recommended to use the ISB, DSB, and DMB 1738 instructions instead. 1739 1740 Say Y here to enable software emulation of these 1741 instructions for AArch32 userspace code. When this option is 1742 enabled, CP15 barrier usage is traced which can help 1743 identify software that needs updating. This feature can be 1744 controlled at runtime with the abi.cp15_barrier sysctl. 1745 1746 If unsure, say Y 1747 1748config SETEND_EMULATION 1749 bool "Emulate SETEND instruction" 1750 help 1751 The SETEND instruction alters the data-endianness of the 1752 AArch32 EL0, and is deprecated in ARMv8. 1753 1754 Say Y here to enable software emulation of the instruction 1755 for AArch32 userspace code. This feature can be controlled 1756 at runtime with the abi.setend sysctl. 1757 1758 Note: All the cpus on the system must have mixed endian support at EL0 1759 for this feature to be enabled. If a new CPU - which doesn't support mixed 1760 endian - is hotplugged in after this feature has been enabled, there could 1761 be unexpected results in the applications. 1762 1763 If unsure, say Y 1764endif # ARMV8_DEPRECATED 1765 1766endif # COMPAT 1767 1768menu "ARMv8.1 architectural features" 1769 1770config ARM64_HW_AFDBM 1771 bool "Support for hardware updates of the Access and Dirty page flags" 1772 default y 1773 help 1774 The ARMv8.1 architecture extensions introduce support for 1775 hardware updates of the access and dirty information in page 1776 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1777 capable processors, accesses to pages with PTE_AF cleared will 1778 set this bit instead of raising an access flag fault. 1779 Similarly, writes to read-only pages with the DBM bit set will 1780 clear the read-only bit (AP[2]) instead of raising a 1781 permission fault. 1782 1783 Kernels built with this configuration option enabled continue 1784 to work on pre-ARMv8.1 hardware and the performance impact is 1785 minimal. If unsure, say Y. 1786 1787config ARM64_PAN 1788 bool "Enable support for Privileged Access Never (PAN)" 1789 default y 1790 help 1791 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1792 prevents the kernel or hypervisor from accessing user-space (EL0) 1793 memory directly. 1794 1795 Choosing this option will cause any unprotected (not using 1796 copy_to_user et al) memory access to fail with a permission fault. 1797 1798 The feature is detected at runtime, and will remain as a 'nop' 1799 instruction if the cpu does not implement the feature. 1800 1801config AS_HAS_LSE_ATOMICS 1802 def_bool $(as-instr,.arch_extension lse) 1803 1804config ARM64_LSE_ATOMICS 1805 bool 1806 default ARM64_USE_LSE_ATOMICS 1807 depends on AS_HAS_LSE_ATOMICS 1808 1809config ARM64_USE_LSE_ATOMICS 1810 bool "Atomic instructions" 1811 default y 1812 help 1813 As part of the Large System Extensions, ARMv8.1 introduces new 1814 atomic instructions that are designed specifically to scale in 1815 very large systems. 1816 1817 Say Y here to make use of these instructions for the in-kernel 1818 atomic routines. This incurs a small overhead on CPUs that do 1819 not support these instructions and requires the kernel to be 1820 built with binutils >= 2.25 in order for the new instructions 1821 to be used. 1822 1823endmenu # "ARMv8.1 architectural features" 1824 1825menu "ARMv8.2 architectural features" 1826 1827config AS_HAS_ARMV8_2 1828 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1829 1830config AS_HAS_SHA3 1831 def_bool $(as-instr,.arch armv8.2-a+sha3) 1832 1833config ARM64_PMEM 1834 bool "Enable support for persistent memory" 1835 select ARCH_HAS_PMEM_API 1836 select ARCH_HAS_UACCESS_FLUSHCACHE 1837 help 1838 Say Y to enable support for the persistent memory API based on the 1839 ARMv8.2 DCPoP feature. 1840 1841 The feature is detected at runtime, and the kernel will use DC CVAC 1842 operations if DC CVAP is not supported (following the behaviour of 1843 DC CVAP itself if the system does not define a point of persistence). 1844 1845config ARM64_RAS_EXTN 1846 bool "Enable support for RAS CPU Extensions" 1847 default y 1848 help 1849 CPUs that support the Reliability, Availability and Serviceability 1850 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1851 errors, classify them and report them to software. 1852 1853 On CPUs with these extensions system software can use additional 1854 barriers to determine if faults are pending and read the 1855 classification from a new set of registers. 1856 1857 Selecting this feature will allow the kernel to use these barriers 1858 and access the new registers if the system supports the extension. 1859 Platform RAS features may additionally depend on firmware support. 1860 1861config ARM64_CNP 1862 bool "Enable support for Common Not Private (CNP) translations" 1863 default y 1864 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1865 help 1866 Common Not Private (CNP) allows translation table entries to 1867 be shared between different PEs in the same inner shareable 1868 domain, so the hardware can use this fact to optimise the 1869 caching of such entries in the TLB. 1870 1871 Selecting this option allows the CNP feature to be detected 1872 at runtime, and does not affect PEs that do not implement 1873 this feature. 1874 1875endmenu # "ARMv8.2 architectural features" 1876 1877menu "ARMv8.3 architectural features" 1878 1879config ARM64_PTR_AUTH 1880 bool "Enable support for pointer authentication" 1881 default y 1882 help 1883 Pointer authentication (part of the ARMv8.3 Extensions) provides 1884 instructions for signing and authenticating pointers against secret 1885 keys, which can be used to mitigate Return Oriented Programming (ROP) 1886 and other attacks. 1887 1888 This option enables these instructions at EL0 (i.e. for userspace). 1889 Choosing this option will cause the kernel to initialise secret keys 1890 for each process at exec() time, with these keys being 1891 context-switched along with the process. 1892 1893 The feature is detected at runtime. If the feature is not present in 1894 hardware it will not be advertised to userspace/KVM guest nor will it 1895 be enabled. 1896 1897 If the feature is present on the boot CPU but not on a late CPU, then 1898 the late CPU will be parked. Also, if the boot CPU does not have 1899 address auth and the late CPU has then the late CPU will still boot 1900 but with the feature disabled. On such a system, this option should 1901 not be selected. 1902 1903config ARM64_PTR_AUTH_KERNEL 1904 bool "Use pointer authentication for kernel" 1905 default y 1906 depends on ARM64_PTR_AUTH 1907 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1908 # Modern compilers insert a .note.gnu.property section note for PAC 1909 # which is only understood by binutils starting with version 2.33.1. 1910 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1911 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1912 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1913 help 1914 If the compiler supports the -mbranch-protection or 1915 -msign-return-address flag (e.g. GCC 7 or later), then this option 1916 will cause the kernel itself to be compiled with return address 1917 protection. In this case, and if the target hardware is known to 1918 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1919 disabled with minimal loss of protection. 1920 1921 This feature works with FUNCTION_GRAPH_TRACER option only if 1922 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1923 1924config CC_HAS_BRANCH_PROT_PAC_RET 1925 # GCC 9 or later, clang 8 or later 1926 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1927 1928config CC_HAS_SIGN_RETURN_ADDRESS 1929 # GCC 7, 8 1930 def_bool $(cc-option,-msign-return-address=all) 1931 1932config AS_HAS_ARMV8_3 1933 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1934 1935config AS_HAS_CFI_NEGATE_RA_STATE 1936 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1937 1938config AS_HAS_LDAPR 1939 def_bool $(as-instr,.arch_extension rcpc) 1940 1941endmenu # "ARMv8.3 architectural features" 1942 1943menu "ARMv8.4 architectural features" 1944 1945config ARM64_AMU_EXTN 1946 bool "Enable support for the Activity Monitors Unit CPU extension" 1947 default y 1948 help 1949 The activity monitors extension is an optional extension introduced 1950 by the ARMv8.4 CPU architecture. This enables support for version 1 1951 of the activity monitors architecture, AMUv1. 1952 1953 To enable the use of this extension on CPUs that implement it, say Y. 1954 1955 Note that for architectural reasons, firmware _must_ implement AMU 1956 support when running on CPUs that present the activity monitors 1957 extension. The required support is present in: 1958 * Version 1.5 and later of the ARM Trusted Firmware 1959 1960 For kernels that have this configuration enabled but boot with broken 1961 firmware, you may need to say N here until the firmware is fixed. 1962 Otherwise you may experience firmware panics or lockups when 1963 accessing the counter registers. Even if you are not observing these 1964 symptoms, the values returned by the register reads might not 1965 correctly reflect reality. Most commonly, the value read will be 0, 1966 indicating that the counter is not enabled. 1967 1968config AS_HAS_ARMV8_4 1969 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1970 1971config ARM64_TLB_RANGE 1972 bool "Enable support for tlbi range feature" 1973 default y 1974 depends on AS_HAS_ARMV8_4 1975 help 1976 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1977 range of input addresses. 1978 1979 The feature introduces new assembly instructions, and they were 1980 support when binutils >= 2.30. 1981 1982endmenu # "ARMv8.4 architectural features" 1983 1984menu "ARMv8.5 architectural features" 1985 1986config AS_HAS_ARMV8_5 1987 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1988 1989config ARM64_BTI 1990 bool "Branch Target Identification support" 1991 default y 1992 help 1993 Branch Target Identification (part of the ARMv8.5 Extensions) 1994 provides a mechanism to limit the set of locations to which computed 1995 branch instructions such as BR or BLR can jump. 1996 1997 To make use of BTI on CPUs that support it, say Y. 1998 1999 BTI is intended to provide complementary protection to other control 2000 flow integrity protection mechanisms, such as the Pointer 2001 authentication mechanism provided as part of the ARMv8.3 Extensions. 2002 For this reason, it does not make sense to enable this option without 2003 also enabling support for pointer authentication. Thus, when 2004 enabling this option you should also select ARM64_PTR_AUTH=y. 2005 2006 Userspace binaries must also be specifically compiled to make use of 2007 this mechanism. If you say N here or the hardware does not support 2008 BTI, such binaries can still run, but you get no additional 2009 enforcement of branch destinations. 2010 2011config ARM64_BTI_KERNEL 2012 bool "Use Branch Target Identification for kernel" 2013 default y 2014 depends on ARM64_BTI 2015 depends on ARM64_PTR_AUTH_KERNEL 2016 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2017 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2018 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2019 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2020 depends on !CC_IS_GCC 2021 # https://github.com/llvm/llvm-project/commit/a88c722e687e6780dcd6a58718350dc76fcc4cc9 2022 depends on !CC_IS_CLANG || CLANG_VERSION >= 120000 2023 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2024 help 2025 Build the kernel with Branch Target Identification annotations 2026 and enable enforcement of this for kernel code. When this option 2027 is enabled and the system supports BTI all kernel code including 2028 modular code must have BTI enabled. 2029 2030config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2031 # GCC 9 or later, clang 8 or later 2032 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2033 2034config ARM64_E0PD 2035 bool "Enable support for E0PD" 2036 default y 2037 help 2038 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2039 that EL0 accesses made via TTBR1 always fault in constant time, 2040 providing similar benefits to KASLR as those provided by KPTI, but 2041 with lower overhead and without disrupting legitimate access to 2042 kernel memory such as SPE. 2043 2044 This option enables E0PD for TTBR1 where available. 2045 2046config ARM64_AS_HAS_MTE 2047 # Initial support for MTE went in binutils 2.32.0, checked with 2048 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2049 # as a late addition to the final architecture spec (LDGM/STGM) 2050 # is only supported in the newer 2.32.x and 2.33 binutils 2051 # versions, hence the extra "stgm" instruction check below. 2052 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2053 2054config ARM64_MTE 2055 bool "Memory Tagging Extension support" 2056 default y 2057 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2058 depends on AS_HAS_ARMV8_5 2059 depends on AS_HAS_LSE_ATOMICS 2060 # Required for tag checking in the uaccess routines 2061 depends on ARM64_PAN 2062 select ARCH_HAS_SUBPAGE_FAULTS 2063 select ARCH_USES_HIGH_VMA_FLAGS 2064 select ARCH_USES_PG_ARCH_X 2065 help 2066 Memory Tagging (part of the ARMv8.5 Extensions) provides 2067 architectural support for run-time, always-on detection of 2068 various classes of memory error to aid with software debugging 2069 to eliminate vulnerabilities arising from memory-unsafe 2070 languages. 2071 2072 This option enables the support for the Memory Tagging 2073 Extension at EL0 (i.e. for userspace). 2074 2075 Selecting this option allows the feature to be detected at 2076 runtime. Any secondary CPU not implementing this feature will 2077 not be allowed a late bring-up. 2078 2079 Userspace binaries that want to use this feature must 2080 explicitly opt in. The mechanism for the userspace is 2081 described in: 2082 2083 Documentation/arch/arm64/memory-tagging-extension.rst. 2084 2085endmenu # "ARMv8.5 architectural features" 2086 2087menu "ARMv8.7 architectural features" 2088 2089config ARM64_EPAN 2090 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2091 default y 2092 depends on ARM64_PAN 2093 help 2094 Enhanced Privileged Access Never (EPAN) allows Privileged 2095 Access Never to be used with Execute-only mappings. 2096 2097 The feature is detected at runtime, and will remain disabled 2098 if the cpu does not implement the feature. 2099endmenu # "ARMv8.7 architectural features" 2100 2101config ARM64_SVE 2102 bool "ARM Scalable Vector Extension support" 2103 default y 2104 help 2105 The Scalable Vector Extension (SVE) is an extension to the AArch64 2106 execution state which complements and extends the SIMD functionality 2107 of the base architecture to support much larger vectors and to enable 2108 additional vectorisation opportunities. 2109 2110 To enable use of this extension on CPUs that implement it, say Y. 2111 2112 On CPUs that support the SVE2 extensions, this option will enable 2113 those too. 2114 2115 Note that for architectural reasons, firmware _must_ implement SVE 2116 support when running on SVE capable hardware. The required support 2117 is present in: 2118 2119 * version 1.5 and later of the ARM Trusted Firmware 2120 * the AArch64 boot wrapper since commit 5e1261e08abf 2121 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2122 2123 For other firmware implementations, consult the firmware documentation 2124 or vendor. 2125 2126 If you need the kernel to boot on SVE-capable hardware with broken 2127 firmware, you may need to say N here until you get your firmware 2128 fixed. Otherwise, you may experience firmware panics or lockups when 2129 booting the kernel. If unsure and you are not observing these 2130 symptoms, you should assume that it is safe to say Y. 2131 2132config ARM64_SME 2133 bool "ARM Scalable Matrix Extension support" 2134 default y 2135 depends on ARM64_SVE 2136 help 2137 The Scalable Matrix Extension (SME) is an extension to the AArch64 2138 execution state which utilises a substantial subset of the SVE 2139 instruction set, together with the addition of new architectural 2140 register state capable of holding two dimensional matrix tiles to 2141 enable various matrix operations. 2142 2143config ARM64_PSEUDO_NMI 2144 bool "Support for NMI-like interrupts" 2145 select ARM_GIC_V3 2146 help 2147 Adds support for mimicking Non-Maskable Interrupts through the use of 2148 GIC interrupt priority. This support requires version 3 or later of 2149 ARM GIC. 2150 2151 This high priority configuration for interrupts needs to be 2152 explicitly enabled by setting the kernel parameter 2153 "irqchip.gicv3_pseudo_nmi" to 1. 2154 2155 If unsure, say N 2156 2157if ARM64_PSEUDO_NMI 2158config ARM64_DEBUG_PRIORITY_MASKING 2159 bool "Debug interrupt priority masking" 2160 help 2161 This adds runtime checks to functions enabling/disabling 2162 interrupts when using priority masking. The additional checks verify 2163 the validity of ICC_PMR_EL1 when calling concerned functions. 2164 2165 If unsure, say N 2166endif # ARM64_PSEUDO_NMI 2167 2168config RELOCATABLE 2169 bool "Build a relocatable kernel image" if EXPERT 2170 select ARCH_HAS_RELR 2171 default y 2172 help 2173 This builds the kernel as a Position Independent Executable (PIE), 2174 which retains all relocation metadata required to relocate the 2175 kernel binary at runtime to a different virtual address than the 2176 address it was linked at. 2177 Since AArch64 uses the RELA relocation format, this requires a 2178 relocation pass at runtime even if the kernel is loaded at the 2179 same address it was linked at. 2180 2181config RANDOMIZE_BASE 2182 bool "Randomize the address of the kernel image" 2183 select RELOCATABLE 2184 help 2185 Randomizes the virtual address at which the kernel image is 2186 loaded, as a security feature that deters exploit attempts 2187 relying on knowledge of the location of kernel internals. 2188 2189 It is the bootloader's job to provide entropy, by passing a 2190 random u64 value in /chosen/kaslr-seed at kernel entry. 2191 2192 When booting via the UEFI stub, it will invoke the firmware's 2193 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2194 to the kernel proper. In addition, it will randomise the physical 2195 location of the kernel Image as well. 2196 2197 If unsure, say N. 2198 2199config RANDOMIZE_MODULE_REGION_FULL 2200 bool "Randomize the module region over a 2 GB range" 2201 depends on RANDOMIZE_BASE 2202 default y 2203 help 2204 Randomizes the location of the module region inside a 2 GB window 2205 covering the core kernel. This way, it is less likely for modules 2206 to leak information about the location of core kernel data structures 2207 but it does imply that function calls between modules and the core 2208 kernel will need to be resolved via veneers in the module PLT. 2209 2210 When this option is not set, the module region will be randomized over 2211 a limited range that contains the [_stext, _etext] interval of the 2212 core kernel, so branch relocations are almost always in range unless 2213 the region is exhausted. In this particular case of region 2214 exhaustion, modules might be able to fall back to a larger 2GB area. 2215 2216config CC_HAVE_STACKPROTECTOR_SYSREG 2217 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2218 2219config STACKPROTECTOR_PER_TASK 2220 def_bool y 2221 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2222 2223config UNWIND_PATCH_PAC_INTO_SCS 2224 bool "Enable shadow call stack dynamically using code patching" 2225 # needs Clang with https://reviews.llvm.org/D111780 incorporated 2226 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2227 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2228 depends on SHADOW_CALL_STACK 2229 select UNWIND_TABLES 2230 select DYNAMIC_SCS 2231 2232endmenu # "Kernel Features" 2233 2234menu "Boot options" 2235 2236config ARM64_ACPI_PARKING_PROTOCOL 2237 bool "Enable support for the ARM64 ACPI parking protocol" 2238 depends on ACPI 2239 help 2240 Enable support for the ARM64 ACPI parking protocol. If disabled 2241 the kernel will not allow booting through the ARM64 ACPI parking 2242 protocol even if the corresponding data is present in the ACPI 2243 MADT table. 2244 2245config CMDLINE 2246 string "Default kernel command string" 2247 default "" 2248 help 2249 Provide a set of default command-line options at build time by 2250 entering them here. As a minimum, you should specify the the 2251 root device (e.g. root=/dev/nfs). 2252 2253choice 2254 prompt "Kernel command line type" if CMDLINE != "" 2255 default CMDLINE_FROM_BOOTLOADER 2256 help 2257 Choose how the kernel will handle the provided default kernel 2258 command line string. 2259 2260config CMDLINE_FROM_BOOTLOADER 2261 bool "Use bootloader kernel arguments if available" 2262 help 2263 Uses the command-line options passed by the boot loader. If 2264 the boot loader doesn't provide any, the default kernel command 2265 string provided in CMDLINE will be used. 2266 2267config CMDLINE_FORCE 2268 bool "Always use the default kernel command string" 2269 help 2270 Always use the default kernel command string, even if the boot 2271 loader passes other arguments to the kernel. 2272 This is useful if you cannot or don't want to change the 2273 command-line options your boot loader passes to the kernel. 2274 2275endchoice 2276 2277config EFI_STUB 2278 bool 2279 2280config EFI 2281 bool "UEFI runtime support" 2282 depends on OF && !CPU_BIG_ENDIAN 2283 depends on KERNEL_MODE_NEON 2284 select ARCH_SUPPORTS_ACPI 2285 select LIBFDT 2286 select UCS2_STRING 2287 select EFI_PARAMS_FROM_FDT 2288 select EFI_RUNTIME_WRAPPERS 2289 select EFI_STUB 2290 select EFI_GENERIC_STUB 2291 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2292 default y 2293 help 2294 This option provides support for runtime services provided 2295 by UEFI firmware (such as non-volatile variables, realtime 2296 clock, and platform reset). A UEFI stub is also provided to 2297 allow the kernel to be booted as an EFI application. This 2298 is only useful on systems that have UEFI firmware. 2299 2300config DMI 2301 bool "Enable support for SMBIOS (DMI) tables" 2302 depends on EFI 2303 default y 2304 help 2305 This enables SMBIOS/DMI feature for systems. 2306 2307 This option is only useful on systems that have UEFI firmware. 2308 However, even with this option, the resultant kernel should 2309 continue to boot on existing non-UEFI platforms. 2310 2311endmenu # "Boot options" 2312 2313menu "Power management options" 2314 2315source "kernel/power/Kconfig" 2316 2317config ARCH_HIBERNATION_POSSIBLE 2318 def_bool y 2319 depends on CPU_PM 2320 2321config ARCH_HIBERNATION_HEADER 2322 def_bool y 2323 depends on HIBERNATION 2324 2325config ARCH_SUSPEND_POSSIBLE 2326 def_bool y 2327 2328endmenu # "Power management options" 2329 2330menu "CPU Power Management" 2331 2332source "drivers/cpuidle/Kconfig" 2333 2334source "drivers/cpufreq/Kconfig" 2335 2336endmenu # "CPU Power Management" 2337 2338source "drivers/acpi/Kconfig" 2339 2340source "arch/arm64/kvm/Kconfig" 2341 2342