1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_CCA_REQUIRED if ACPI 5 select ACPI_GENERIC_GSI if ACPI 6 select ACPI_GTDT if ACPI 7 select ACPI_IORT if ACPI 8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 9 select ACPI_MCFG if (ACPI && PCI) 10 select ACPI_SPCR_TABLE if ACPI 11 select ACPI_PPTT if ACPI 12 select ARCH_HAS_DEBUG_WX 13 select ARCH_BINFMT_ELF_STATE 14 select ARCH_HAS_DEBUG_VIRTUAL 15 select ARCH_HAS_DEBUG_VM_PGTABLE 16 select ARCH_HAS_DEVMEM_IS_ALLOWED 17 select ARCH_HAS_DMA_PREP_COHERENT 18 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 19 select ARCH_HAS_FAST_MULTIPLIER 20 select ARCH_HAS_FORTIFY_SOURCE 21 select ARCH_HAS_GCOV_PROFILE_ALL 22 select ARCH_HAS_GIGANTIC_PAGE 23 select ARCH_HAS_KCOV 24 select ARCH_HAS_KEEPINITRD 25 select ARCH_HAS_MEMBARRIER_SYNC_CORE 26 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 27 select ARCH_HAS_PTE_DEVMAP 28 select ARCH_HAS_PTE_SPECIAL 29 select ARCH_HAS_SETUP_DMA_OPS 30 select ARCH_HAS_SET_DIRECT_MAP 31 select ARCH_HAS_SET_MEMORY 32 select ARCH_STACKWALK 33 select ARCH_HAS_STRICT_KERNEL_RWX 34 select ARCH_HAS_STRICT_MODULE_RWX 35 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 36 select ARCH_HAS_SYNC_DMA_FOR_CPU 37 select ARCH_HAS_SYSCALL_WRAPPER 38 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 39 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 40 select ARCH_HAVE_ELF_PROT 41 select ARCH_HAVE_NMI_SAFE_CMPXCHG 42 select ARCH_INLINE_READ_LOCK if !PREEMPTION 43 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 44 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 45 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 46 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 47 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 48 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 49 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 50 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 51 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 52 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 53 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 54 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 55 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 56 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 57 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 58 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 59 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 60 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 61 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 62 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 63 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 64 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 65 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 66 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 67 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 68 select ARCH_KEEP_MEMBLOCK 69 select ARCH_USE_CMPXCHG_LOCKREF 70 select ARCH_USE_GNU_PROPERTY 71 select ARCH_USE_QUEUED_RWLOCKS 72 select ARCH_USE_QUEUED_SPINLOCKS 73 select ARCH_USE_SYM_ANNOTATIONS 74 select ARCH_SUPPORTS_MEMORY_FAILURE 75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 76 select ARCH_SUPPORTS_ATOMIC_RMW 77 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) 78 select ARCH_SUPPORTS_NUMA_BALANCING 79 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 80 select ARCH_WANT_DEFAULT_BPF_JIT 81 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 82 select ARCH_WANT_FRAME_POINTERS 83 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 84 select ARCH_HAS_UBSAN_SANITIZE_ALL 85 select ARM_AMBA 86 select ARM_ARCH_TIMER 87 select ARM_GIC 88 select AUDIT_ARCH_COMPAT_GENERIC 89 select ARM_GIC_V2M if PCI 90 select ARM_GIC_V3 91 select ARM_GIC_V3_ITS if PCI 92 select ARM_PSCI_FW 93 select BUILDTIME_TABLE_SORT 94 select CLONE_BACKWARDS 95 select COMMON_CLK 96 select CPU_PM if (SUSPEND || CPU_IDLE) 97 select CRC32 98 select DCACHE_WORD_ACCESS 99 select DMA_DIRECT_REMAP 100 select EDAC_SUPPORT 101 select FRAME_POINTER 102 select GENERIC_ALLOCATOR 103 select GENERIC_ARCH_TOPOLOGY 104 select GENERIC_CLOCKEVENTS 105 select GENERIC_CLOCKEVENTS_BROADCAST 106 select GENERIC_CPU_AUTOPROBE 107 select GENERIC_CPU_VULNERABILITIES 108 select GENERIC_EARLY_IOREMAP 109 select GENERIC_IDLE_POLL_SETUP 110 select GENERIC_IRQ_IPI 111 select GENERIC_IRQ_MULTI_HANDLER 112 select GENERIC_IRQ_PROBE 113 select GENERIC_IRQ_SHOW 114 select GENERIC_IRQ_SHOW_LEVEL 115 select GENERIC_PCI_IOMAP 116 select GENERIC_PTDUMP 117 select GENERIC_SCHED_CLOCK 118 select GENERIC_SMP_IDLE_THREAD 119 select GENERIC_STRNCPY_FROM_USER 120 select GENERIC_STRNLEN_USER 121 select GENERIC_TIME_VSYSCALL 122 select GENERIC_GETTIMEOFDAY 123 select GENERIC_VDSO_TIME_NS 124 select HANDLE_DOMAIN_IRQ 125 select HARDIRQS_SW_RESEND 126 select HAVE_PCI 127 select HAVE_ACPI_APEI if (ACPI && EFI) 128 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 129 select HAVE_ARCH_AUDITSYSCALL 130 select HAVE_ARCH_BITREVERSE 131 select HAVE_ARCH_COMPILER_H 132 select HAVE_ARCH_HUGE_VMAP 133 select HAVE_ARCH_JUMP_LABEL 134 select HAVE_ARCH_JUMP_LABEL_RELATIVE 135 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 136 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 137 select HAVE_ARCH_KGDB 138 select HAVE_ARCH_MMAP_RND_BITS 139 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 140 select HAVE_ARCH_PREL32_RELOCATIONS 141 select HAVE_ARCH_SECCOMP_FILTER 142 select HAVE_ARCH_STACKLEAK 143 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 144 select HAVE_ARCH_TRACEHOOK 145 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 146 select HAVE_ARCH_VMAP_STACK 147 select HAVE_ARM_SMCCC 148 select HAVE_ASM_MODVERSIONS 149 select HAVE_EBPF_JIT 150 select HAVE_C_RECORDMCOUNT 151 select HAVE_CMPXCHG_DOUBLE 152 select HAVE_CMPXCHG_LOCAL 153 select HAVE_CONTEXT_TRACKING 154 select HAVE_DEBUG_BUGVERBOSE 155 select HAVE_DEBUG_KMEMLEAK 156 select HAVE_DMA_CONTIGUOUS 157 select HAVE_DYNAMIC_FTRACE 158 select HAVE_DYNAMIC_FTRACE_WITH_REGS \ 159 if $(cc-option,-fpatchable-function-entry=2) 160 select HAVE_EFFICIENT_UNALIGNED_ACCESS 161 select HAVE_FAST_GUP 162 select HAVE_FTRACE_MCOUNT_RECORD 163 select HAVE_FUNCTION_TRACER 164 select HAVE_FUNCTION_ERROR_INJECTION 165 select HAVE_FUNCTION_GRAPH_TRACER 166 select HAVE_GCC_PLUGINS 167 select HAVE_HW_BREAKPOINT if PERF_EVENTS 168 select HAVE_IRQ_TIME_ACCOUNTING 169 select HAVE_NMI 170 select HAVE_PATA_PLATFORM 171 select HAVE_PERF_EVENTS 172 select HAVE_PERF_REGS 173 select HAVE_PERF_USER_STACK_DUMP 174 select HAVE_REGS_AND_STACK_ACCESS_API 175 select HAVE_FUNCTION_ARG_ACCESS_API 176 select HAVE_FUTEX_CMPXCHG if FUTEX 177 select MMU_GATHER_RCU_TABLE_FREE 178 select HAVE_RSEQ 179 select HAVE_STACKPROTECTOR 180 select HAVE_SYSCALL_TRACEPOINTS 181 select HAVE_KPROBES 182 select HAVE_KRETPROBES 183 select HAVE_GENERIC_VDSO 184 select IOMMU_DMA if IOMMU_SUPPORT 185 select IRQ_DOMAIN 186 select IRQ_FORCED_THREADING 187 select MODULES_USE_ELF_RELA 188 select NEED_DMA_MAP_STATE 189 select NEED_SG_DMA_LENGTH 190 select OF 191 select OF_EARLY_FLATTREE 192 select PCI_DOMAINS_GENERIC if PCI 193 select PCI_ECAM if (ACPI && PCI) 194 select PCI_SYSCALL if PCI 195 select POWER_RESET 196 select POWER_SUPPLY 197 select SPARSE_IRQ 198 select SWIOTLB 199 select SYSCTL_EXCEPTION_TRACE 200 select THREAD_INFO_IN_TASK 201 help 202 ARM 64-bit (AArch64) Linux support. 203 204config 64BIT 205 def_bool y 206 207config MMU 208 def_bool y 209 210config ARM64_PAGE_SHIFT 211 int 212 default 16 if ARM64_64K_PAGES 213 default 14 if ARM64_16K_PAGES 214 default 12 215 216config ARM64_CONT_PTE_SHIFT 217 int 218 default 5 if ARM64_64K_PAGES 219 default 7 if ARM64_16K_PAGES 220 default 4 221 222config ARM64_CONT_PMD_SHIFT 223 int 224 default 5 if ARM64_64K_PAGES 225 default 5 if ARM64_16K_PAGES 226 default 4 227 228config ARCH_MMAP_RND_BITS_MIN 229 default 14 if ARM64_64K_PAGES 230 default 16 if ARM64_16K_PAGES 231 default 18 232 233# max bits determined by the following formula: 234# VA_BITS - PAGE_SHIFT - 3 235config ARCH_MMAP_RND_BITS_MAX 236 default 19 if ARM64_VA_BITS=36 237 default 24 if ARM64_VA_BITS=39 238 default 27 if ARM64_VA_BITS=42 239 default 30 if ARM64_VA_BITS=47 240 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 241 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 242 default 33 if ARM64_VA_BITS=48 243 default 14 if ARM64_64K_PAGES 244 default 16 if ARM64_16K_PAGES 245 default 18 246 247config ARCH_MMAP_RND_COMPAT_BITS_MIN 248 default 7 if ARM64_64K_PAGES 249 default 9 if ARM64_16K_PAGES 250 default 11 251 252config ARCH_MMAP_RND_COMPAT_BITS_MAX 253 default 16 254 255config NO_IOPORT_MAP 256 def_bool y if !PCI 257 258config STACKTRACE_SUPPORT 259 def_bool y 260 261config ILLEGAL_POINTER_VALUE 262 hex 263 default 0xdead000000000000 264 265config LOCKDEP_SUPPORT 266 def_bool y 267 268config TRACE_IRQFLAGS_SUPPORT 269 def_bool y 270 271config GENERIC_BUG 272 def_bool y 273 depends on BUG 274 275config GENERIC_BUG_RELATIVE_POINTERS 276 def_bool y 277 depends on GENERIC_BUG 278 279config GENERIC_HWEIGHT 280 def_bool y 281 282config GENERIC_CSUM 283 def_bool y 284 285config GENERIC_CALIBRATE_DELAY 286 def_bool y 287 288config ZONE_DMA 289 bool "Support DMA zone" if EXPERT 290 default y 291 292config ZONE_DMA32 293 bool "Support DMA32 zone" if EXPERT 294 default y 295 296config ARCH_ENABLE_MEMORY_HOTPLUG 297 def_bool y 298 299config ARCH_ENABLE_MEMORY_HOTREMOVE 300 def_bool y 301 302config SMP 303 def_bool y 304 305config KERNEL_MODE_NEON 306 def_bool y 307 308config FIX_EARLYCON_MEM 309 def_bool y 310 311config PGTABLE_LEVELS 312 int 313 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 314 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 315 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 316 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 317 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 318 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 319 320config ARCH_SUPPORTS_UPROBES 321 def_bool y 322 323config ARCH_PROC_KCORE_TEXT 324 def_bool y 325 326config BROKEN_GAS_INST 327 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 328 329config KASAN_SHADOW_OFFSET 330 hex 331 depends on KASAN 332 default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 333 default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 334 default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 335 default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 336 default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 337 default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 338 default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 339 default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 340 default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 341 default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 342 default 0xffffffffffffffff 343 344source "arch/arm64/Kconfig.platforms" 345 346menu "Kernel Features" 347 348menu "ARM errata workarounds via the alternatives framework" 349 350config ARM64_WORKAROUND_CLEAN_CACHE 351 bool 352 353config ARM64_ERRATUM_826319 354 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 355 default y 356 select ARM64_WORKAROUND_CLEAN_CACHE 357 help 358 This option adds an alternative code sequence to work around ARM 359 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 360 AXI master interface and an L2 cache. 361 362 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 363 and is unable to accept a certain write via this interface, it will 364 not progress on read data presented on the read data channel and the 365 system can deadlock. 366 367 The workaround promotes data cache clean instructions to 368 data cache clean-and-invalidate. 369 Please note that this does not necessarily enable the workaround, 370 as it depends on the alternative framework, which will only patch 371 the kernel if an affected CPU is detected. 372 373 If unsure, say Y. 374 375config ARM64_ERRATUM_827319 376 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 377 default y 378 select ARM64_WORKAROUND_CLEAN_CACHE 379 help 380 This option adds an alternative code sequence to work around ARM 381 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 382 master interface and an L2 cache. 383 384 Under certain conditions this erratum can cause a clean line eviction 385 to occur at the same time as another transaction to the same address 386 on the AMBA 5 CHI interface, which can cause data corruption if the 387 interconnect reorders the two transactions. 388 389 The workaround promotes data cache clean instructions to 390 data cache clean-and-invalidate. 391 Please note that this does not necessarily enable the workaround, 392 as it depends on the alternative framework, which will only patch 393 the kernel if an affected CPU is detected. 394 395 If unsure, say Y. 396 397config ARM64_ERRATUM_824069 398 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 399 default y 400 select ARM64_WORKAROUND_CLEAN_CACHE 401 help 402 This option adds an alternative code sequence to work around ARM 403 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 404 to a coherent interconnect. 405 406 If a Cortex-A53 processor is executing a store or prefetch for 407 write instruction at the same time as a processor in another 408 cluster is executing a cache maintenance operation to the same 409 address, then this erratum might cause a clean cache line to be 410 incorrectly marked as dirty. 411 412 The workaround promotes data cache clean instructions to 413 data cache clean-and-invalidate. 414 Please note that this option does not necessarily enable the 415 workaround, as it depends on the alternative framework, which will 416 only patch the kernel if an affected CPU is detected. 417 418 If unsure, say Y. 419 420config ARM64_ERRATUM_819472 421 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 422 default y 423 select ARM64_WORKAROUND_CLEAN_CACHE 424 help 425 This option adds an alternative code sequence to work around ARM 426 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 427 present when it is connected to a coherent interconnect. 428 429 If the processor is executing a load and store exclusive sequence at 430 the same time as a processor in another cluster is executing a cache 431 maintenance operation to the same address, then this erratum might 432 cause data corruption. 433 434 The workaround promotes data cache clean instructions to 435 data cache clean-and-invalidate. 436 Please note that this does not necessarily enable the workaround, 437 as it depends on the alternative framework, which will only patch 438 the kernel if an affected CPU is detected. 439 440 If unsure, say Y. 441 442config ARM64_ERRATUM_832075 443 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 444 default y 445 help 446 This option adds an alternative code sequence to work around ARM 447 erratum 832075 on Cortex-A57 parts up to r1p2. 448 449 Affected Cortex-A57 parts might deadlock when exclusive load/store 450 instructions to Write-Back memory are mixed with Device loads. 451 452 The workaround is to promote device loads to use Load-Acquire 453 semantics. 454 Please note that this does not necessarily enable the workaround, 455 as it depends on the alternative framework, which will only patch 456 the kernel if an affected CPU is detected. 457 458 If unsure, say Y. 459 460config ARM64_ERRATUM_834220 461 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 462 depends on KVM 463 default y 464 help 465 This option adds an alternative code sequence to work around ARM 466 erratum 834220 on Cortex-A57 parts up to r1p2. 467 468 Affected Cortex-A57 parts might report a Stage 2 translation 469 fault as the result of a Stage 1 fault for load crossing a 470 page boundary when there is a permission or device memory 471 alignment fault at Stage 1 and a translation fault at Stage 2. 472 473 The workaround is to verify that the Stage 1 translation 474 doesn't generate a fault before handling the Stage 2 fault. 475 Please note that this does not necessarily enable the workaround, 476 as it depends on the alternative framework, which will only patch 477 the kernel if an affected CPU is detected. 478 479 If unsure, say Y. 480 481config ARM64_ERRATUM_845719 482 bool "Cortex-A53: 845719: a load might read incorrect data" 483 depends on COMPAT 484 default y 485 help 486 This option adds an alternative code sequence to work around ARM 487 erratum 845719 on Cortex-A53 parts up to r0p4. 488 489 When running a compat (AArch32) userspace on an affected Cortex-A53 490 part, a load at EL0 from a virtual address that matches the bottom 32 491 bits of the virtual address used by a recent load at (AArch64) EL1 492 might return incorrect data. 493 494 The workaround is to write the contextidr_el1 register on exception 495 return to a 32-bit task. 496 Please note that this does not necessarily enable the workaround, 497 as it depends on the alternative framework, which will only patch 498 the kernel if an affected CPU is detected. 499 500 If unsure, say Y. 501 502config ARM64_ERRATUM_843419 503 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 504 default y 505 select ARM64_MODULE_PLTS if MODULES 506 help 507 This option links the kernel with '--fix-cortex-a53-843419' and 508 enables PLT support to replace certain ADRP instructions, which can 509 cause subsequent memory accesses to use an incorrect address on 510 Cortex-A53 parts up to r0p4. 511 512 If unsure, say Y. 513 514config ARM64_ERRATUM_1024718 515 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 516 default y 517 help 518 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 519 520 Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect 521 update of the hardware dirty bit when the DBM/AP bits are updated 522 without a break-before-make. The workaround is to disable the usage 523 of hardware DBM locally on the affected cores. CPUs not affected by 524 this erratum will continue to use the feature. 525 526 If unsure, say Y. 527 528config ARM64_ERRATUM_1418040 529 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 530 default y 531 depends on COMPAT 532 help 533 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 534 errata 1188873 and 1418040. 535 536 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 537 cause register corruption when accessing the timer registers 538 from AArch32 userspace. 539 540 If unsure, say Y. 541 542config ARM64_WORKAROUND_SPECULATIVE_AT 543 bool 544 545config ARM64_ERRATUM_1165522 546 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 547 default y 548 select ARM64_WORKAROUND_SPECULATIVE_AT 549 help 550 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 551 552 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 553 corrupted TLBs by speculating an AT instruction during a guest 554 context switch. 555 556 If unsure, say Y. 557 558config ARM64_ERRATUM_1319367 559 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 560 default y 561 select ARM64_WORKAROUND_SPECULATIVE_AT 562 help 563 This option adds work arounds for ARM Cortex-A57 erratum 1319537 564 and A72 erratum 1319367 565 566 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 567 speculating an AT instruction during a guest context switch. 568 569 If unsure, say Y. 570 571config ARM64_ERRATUM_1530923 572 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 573 default y 574 select ARM64_WORKAROUND_SPECULATIVE_AT 575 help 576 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 577 578 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 579 corrupted TLBs by speculating an AT instruction during a guest 580 context switch. 581 582 If unsure, say Y. 583 584config ARM64_WORKAROUND_REPEAT_TLBI 585 bool 586 587config ARM64_ERRATUM_1286807 588 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 589 default y 590 select ARM64_WORKAROUND_REPEAT_TLBI 591 help 592 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 593 594 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 595 address for a cacheable mapping of a location is being 596 accessed by a core while another core is remapping the virtual 597 address to a new physical page using the recommended 598 break-before-make sequence, then under very rare circumstances 599 TLBI+DSB completes before a read using the translation being 600 invalidated has been observed by other observers. The 601 workaround repeats the TLBI+DSB operation. 602 603config ARM64_ERRATUM_1463225 604 bool "Cortex-A76: Software Step might prevent interrupt recognition" 605 default y 606 help 607 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 608 609 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 610 of a system call instruction (SVC) can prevent recognition of 611 subsequent interrupts when software stepping is disabled in the 612 exception handler of the system call and either kernel debugging 613 is enabled or VHE is in use. 614 615 Work around the erratum by triggering a dummy step exception 616 when handling a system call from a task that is being stepped 617 in a VHE configuration of the kernel. 618 619 If unsure, say Y. 620 621config ARM64_ERRATUM_1542419 622 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 623 default y 624 help 625 This option adds a workaround for ARM Neoverse-N1 erratum 626 1542419. 627 628 Affected Neoverse-N1 cores could execute a stale instruction when 629 modified by another CPU. The workaround depends on a firmware 630 counterpart. 631 632 Workaround the issue by hiding the DIC feature from EL0. This 633 forces user-space to perform cache maintenance. 634 635 If unsure, say Y. 636 637config CAVIUM_ERRATUM_22375 638 bool "Cavium erratum 22375, 24313" 639 default y 640 help 641 Enable workaround for errata 22375 and 24313. 642 643 This implements two gicv3-its errata workarounds for ThunderX. Both 644 with a small impact affecting only ITS table allocation. 645 646 erratum 22375: only alloc 8MB table size 647 erratum 24313: ignore memory access type 648 649 The fixes are in ITS initialization and basically ignore memory access 650 type and table size provided by the TYPER and BASER registers. 651 652 If unsure, say Y. 653 654config CAVIUM_ERRATUM_23144 655 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 656 depends on NUMA 657 default y 658 help 659 ITS SYNC command hang for cross node io and collections/cpu mapping. 660 661 If unsure, say Y. 662 663config CAVIUM_ERRATUM_23154 664 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 665 default y 666 help 667 The gicv3 of ThunderX requires a modified version for 668 reading the IAR status to ensure data synchronization 669 (access to icc_iar1_el1 is not sync'ed before and after). 670 671 If unsure, say Y. 672 673config CAVIUM_ERRATUM_27456 674 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 675 default y 676 help 677 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 678 instructions may cause the icache to become corrupted if it 679 contains data for a non-current ASID. The fix is to 680 invalidate the icache when changing the mm context. 681 682 If unsure, say Y. 683 684config CAVIUM_ERRATUM_30115 685 bool "Cavium erratum 30115: Guest may disable interrupts in host" 686 default y 687 help 688 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 689 1.2, and T83 Pass 1.0, KVM guest execution may disable 690 interrupts in host. Trapping both GICv3 group-0 and group-1 691 accesses sidesteps the issue. 692 693 If unsure, say Y. 694 695config CAVIUM_TX2_ERRATUM_219 696 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 697 default y 698 help 699 On Cavium ThunderX2, a load, store or prefetch instruction between a 700 TTBR update and the corresponding context synchronizing operation can 701 cause a spurious Data Abort to be delivered to any hardware thread in 702 the CPU core. 703 704 Work around the issue by avoiding the problematic code sequence and 705 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 706 trap handler performs the corresponding register access, skips the 707 instruction and ensures context synchronization by virtue of the 708 exception return. 709 710 If unsure, say Y. 711 712config FUJITSU_ERRATUM_010001 713 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 714 default y 715 help 716 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 717 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 718 accesses may cause undefined fault (Data abort, DFSC=0b111111). 719 This fault occurs under a specific hardware condition when a 720 load/store instruction performs an address translation using: 721 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 722 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 723 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 724 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 725 726 The workaround is to ensure these bits are clear in TCR_ELx. 727 The workaround only affects the Fujitsu-A64FX. 728 729 If unsure, say Y. 730 731config HISILICON_ERRATUM_161600802 732 bool "Hip07 161600802: Erroneous redistributor VLPI base" 733 default y 734 help 735 The HiSilicon Hip07 SoC uses the wrong redistributor base 736 when issued ITS commands such as VMOVP and VMAPP, and requires 737 a 128kB offset to be applied to the target address in this commands. 738 739 If unsure, say Y. 740 741config QCOM_FALKOR_ERRATUM_1003 742 bool "Falkor E1003: Incorrect translation due to ASID change" 743 default y 744 help 745 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 746 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 747 in TTBR1_EL1, this situation only occurs in the entry trampoline and 748 then only for entries in the walk cache, since the leaf translation 749 is unchanged. Work around the erratum by invalidating the walk cache 750 entries for the trampoline before entering the kernel proper. 751 752config QCOM_FALKOR_ERRATUM_1009 753 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 754 default y 755 select ARM64_WORKAROUND_REPEAT_TLBI 756 help 757 On Falkor v1, the CPU may prematurely complete a DSB following a 758 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 759 one more time to fix the issue. 760 761 If unsure, say Y. 762 763config QCOM_QDF2400_ERRATUM_0065 764 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 765 default y 766 help 767 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 768 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 769 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 770 771 If unsure, say Y. 772 773config QCOM_FALKOR_ERRATUM_E1041 774 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 775 default y 776 help 777 Falkor CPU may speculatively fetch instructions from an improper 778 memory location when MMU translation is changed from SCTLR_ELn[M]=1 779 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 780 781 If unsure, say Y. 782 783config SOCIONEXT_SYNQUACER_PREITS 784 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 785 default y 786 help 787 Socionext Synquacer SoCs implement a separate h/w block to generate 788 MSI doorbell writes with non-zero values for the device ID. 789 790 If unsure, say Y. 791 792endmenu 793 794 795choice 796 prompt "Page size" 797 default ARM64_4K_PAGES 798 help 799 Page size (translation granule) configuration. 800 801config ARM64_4K_PAGES 802 bool "4KB" 803 help 804 This feature enables 4KB pages support. 805 806config ARM64_16K_PAGES 807 bool "16KB" 808 help 809 The system will use 16KB pages support. AArch32 emulation 810 requires applications compiled with 16K (or a multiple of 16K) 811 aligned segments. 812 813config ARM64_64K_PAGES 814 bool "64KB" 815 help 816 This feature enables 64KB pages support (4KB by default) 817 allowing only two levels of page tables and faster TLB 818 look-up. AArch32 emulation requires applications compiled 819 with 64K aligned segments. 820 821endchoice 822 823choice 824 prompt "Virtual address space size" 825 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 826 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 827 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 828 help 829 Allows choosing one of multiple possible virtual address 830 space sizes. The level of translation table is determined by 831 a combination of page size and virtual address space size. 832 833config ARM64_VA_BITS_36 834 bool "36-bit" if EXPERT 835 depends on ARM64_16K_PAGES 836 837config ARM64_VA_BITS_39 838 bool "39-bit" 839 depends on ARM64_4K_PAGES 840 841config ARM64_VA_BITS_42 842 bool "42-bit" 843 depends on ARM64_64K_PAGES 844 845config ARM64_VA_BITS_47 846 bool "47-bit" 847 depends on ARM64_16K_PAGES 848 849config ARM64_VA_BITS_48 850 bool "48-bit" 851 852config ARM64_VA_BITS_52 853 bool "52-bit" 854 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 855 help 856 Enable 52-bit virtual addressing for userspace when explicitly 857 requested via a hint to mmap(). The kernel will also use 52-bit 858 virtual addresses for its own mappings (provided HW support for 859 this feature is available, otherwise it reverts to 48-bit). 860 861 NOTE: Enabling 52-bit virtual addressing in conjunction with 862 ARMv8.3 Pointer Authentication will result in the PAC being 863 reduced from 7 bits to 3 bits, which may have a significant 864 impact on its susceptibility to brute-force attacks. 865 866 If unsure, select 48-bit virtual addressing instead. 867 868endchoice 869 870config ARM64_FORCE_52BIT 871 bool "Force 52-bit virtual addresses for userspace" 872 depends on ARM64_VA_BITS_52 && EXPERT 873 help 874 For systems with 52-bit userspace VAs enabled, the kernel will attempt 875 to maintain compatibility with older software by providing 48-bit VAs 876 unless a hint is supplied to mmap. 877 878 This configuration option disables the 48-bit compatibility logic, and 879 forces all userspace addresses to be 52-bit on HW that supports it. One 880 should only enable this configuration option for stress testing userspace 881 memory management code. If unsure say N here. 882 883config ARM64_VA_BITS 884 int 885 default 36 if ARM64_VA_BITS_36 886 default 39 if ARM64_VA_BITS_39 887 default 42 if ARM64_VA_BITS_42 888 default 47 if ARM64_VA_BITS_47 889 default 48 if ARM64_VA_BITS_48 890 default 52 if ARM64_VA_BITS_52 891 892choice 893 prompt "Physical address space size" 894 default ARM64_PA_BITS_48 895 help 896 Choose the maximum physical address range that the kernel will 897 support. 898 899config ARM64_PA_BITS_48 900 bool "48-bit" 901 902config ARM64_PA_BITS_52 903 bool "52-bit (ARMv8.2)" 904 depends on ARM64_64K_PAGES 905 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 906 help 907 Enable support for a 52-bit physical address space, introduced as 908 part of the ARMv8.2-LPA extension. 909 910 With this enabled, the kernel will also continue to work on CPUs that 911 do not support ARMv8.2-LPA, but with some added memory overhead (and 912 minor performance overhead). 913 914endchoice 915 916config ARM64_PA_BITS 917 int 918 default 48 if ARM64_PA_BITS_48 919 default 52 if ARM64_PA_BITS_52 920 921choice 922 prompt "Endianness" 923 default CPU_LITTLE_ENDIAN 924 help 925 Select the endianness of data accesses performed by the CPU. Userspace 926 applications will need to be compiled and linked for the endianness 927 that is selected here. 928 929config CPU_BIG_ENDIAN 930 bool "Build big-endian kernel" 931 help 932 Say Y if you plan on running a kernel with a big-endian userspace. 933 934config CPU_LITTLE_ENDIAN 935 bool "Build little-endian kernel" 936 help 937 Say Y if you plan on running a kernel with a little-endian userspace. 938 This is usually the case for distributions targeting arm64. 939 940endchoice 941 942config SCHED_MC 943 bool "Multi-core scheduler support" 944 help 945 Multi-core scheduler support improves the CPU scheduler's decision 946 making when dealing with multi-core CPU chips at a cost of slightly 947 increased overhead in some places. If unsure say N here. 948 949config SCHED_SMT 950 bool "SMT scheduler support" 951 help 952 Improves the CPU scheduler's decision making when dealing with 953 MultiThreading at a cost of slightly increased overhead in some 954 places. If unsure say N here. 955 956config NR_CPUS 957 int "Maximum number of CPUs (2-4096)" 958 range 2 4096 959 default "256" 960 961config HOTPLUG_CPU 962 bool "Support for hot-pluggable CPUs" 963 select GENERIC_IRQ_MIGRATION 964 help 965 Say Y here to experiment with turning CPUs off and on. CPUs 966 can be controlled through /sys/devices/system/cpu. 967 968# Common NUMA Features 969config NUMA 970 bool "NUMA Memory Allocation and Scheduler Support" 971 select ACPI_NUMA if ACPI 972 select OF_NUMA 973 help 974 Enable NUMA (Non-Uniform Memory Access) support. 975 976 The kernel will try to allocate memory used by a CPU on the 977 local memory of the CPU and add some more 978 NUMA awareness to the kernel. 979 980config NODES_SHIFT 981 int "Maximum NUMA Nodes (as a power of 2)" 982 range 1 10 983 default "2" 984 depends on NEED_MULTIPLE_NODES 985 help 986 Specify the maximum number of NUMA Nodes available on the target 987 system. Increases memory reserved to accommodate various tables. 988 989config USE_PERCPU_NUMA_NODE_ID 990 def_bool y 991 depends on NUMA 992 993config HAVE_SETUP_PER_CPU_AREA 994 def_bool y 995 depends on NUMA 996 997config NEED_PER_CPU_EMBED_FIRST_CHUNK 998 def_bool y 999 depends on NUMA 1000 1001config HOLES_IN_ZONE 1002 def_bool y 1003 1004source "kernel/Kconfig.hz" 1005 1006config ARCH_SUPPORTS_DEBUG_PAGEALLOC 1007 def_bool y 1008 1009config ARCH_SPARSEMEM_ENABLE 1010 def_bool y 1011 select SPARSEMEM_VMEMMAP_ENABLE 1012 1013config ARCH_SPARSEMEM_DEFAULT 1014 def_bool ARCH_SPARSEMEM_ENABLE 1015 1016config ARCH_SELECT_MEMORY_MODEL 1017 def_bool ARCH_SPARSEMEM_ENABLE 1018 1019config ARCH_FLATMEM_ENABLE 1020 def_bool !NUMA 1021 1022config HAVE_ARCH_PFN_VALID 1023 def_bool y 1024 1025config HW_PERF_EVENTS 1026 def_bool y 1027 depends on ARM_PMU 1028 1029config SYS_SUPPORTS_HUGETLBFS 1030 def_bool y 1031 1032config ARCH_WANT_HUGE_PMD_SHARE 1033 1034config ARCH_HAS_CACHE_LINE_SIZE 1035 def_bool y 1036 1037config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1038 def_bool y if PGTABLE_LEVELS > 2 1039 1040# Supported by clang >= 7.0 1041config CC_HAVE_SHADOW_CALL_STACK 1042 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1043 1044config SECCOMP 1045 bool "Enable seccomp to safely compute untrusted bytecode" 1046 help 1047 This kernel feature is useful for number crunching applications 1048 that may need to compute untrusted bytecode during their 1049 execution. By using pipes or other transports made available to 1050 the process as file descriptors supporting the read/write 1051 syscalls, it's possible to isolate those applications in 1052 their own address space using seccomp. Once seccomp is 1053 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1054 and the task is only allowed to execute a few safe syscalls 1055 defined by each seccomp mode. 1056 1057config PARAVIRT 1058 bool "Enable paravirtualization code" 1059 help 1060 This changes the kernel so it can modify itself when it is run 1061 under a hypervisor, potentially improving performance significantly 1062 over full virtualization. 1063 1064config PARAVIRT_TIME_ACCOUNTING 1065 bool "Paravirtual steal time accounting" 1066 select PARAVIRT 1067 help 1068 Select this option to enable fine granularity task steal time 1069 accounting. Time spent executing other tasks in parallel with 1070 the current vCPU is discounted from the vCPU power. To account for 1071 that, there can be a small performance impact. 1072 1073 If in doubt, say N here. 1074 1075config KEXEC 1076 depends on PM_SLEEP_SMP 1077 select KEXEC_CORE 1078 bool "kexec system call" 1079 help 1080 kexec is a system call that implements the ability to shutdown your 1081 current kernel, and to start another kernel. It is like a reboot 1082 but it is independent of the system firmware. And like a reboot 1083 you can start any kernel with it, not just Linux. 1084 1085config KEXEC_FILE 1086 bool "kexec file based system call" 1087 select KEXEC_CORE 1088 help 1089 This is new version of kexec system call. This system call is 1090 file based and takes file descriptors as system call argument 1091 for kernel and initramfs as opposed to list of segments as 1092 accepted by previous system call. 1093 1094config KEXEC_SIG 1095 bool "Verify kernel signature during kexec_file_load() syscall" 1096 depends on KEXEC_FILE 1097 help 1098 Select this option to verify a signature with loaded kernel 1099 image. If configured, any attempt of loading a image without 1100 valid signature will fail. 1101 1102 In addition to that option, you need to enable signature 1103 verification for the corresponding kernel image type being 1104 loaded in order for this to work. 1105 1106config KEXEC_IMAGE_VERIFY_SIG 1107 bool "Enable Image signature verification support" 1108 default y 1109 depends on KEXEC_SIG 1110 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1111 help 1112 Enable Image signature verification support. 1113 1114comment "Support for PE file signature verification disabled" 1115 depends on KEXEC_SIG 1116 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1117 1118config CRASH_DUMP 1119 bool "Build kdump crash kernel" 1120 help 1121 Generate crash dump after being started by kexec. This should 1122 be normally only set in special crash dump kernels which are 1123 loaded in the main kernel with kexec-tools into a specially 1124 reserved region and then later executed after a crash by 1125 kdump/kexec. 1126 1127 For more details see Documentation/admin-guide/kdump/kdump.rst 1128 1129config XEN_DOM0 1130 def_bool y 1131 depends on XEN 1132 1133config XEN 1134 bool "Xen guest support on ARM64" 1135 depends on ARM64 && OF 1136 select SWIOTLB_XEN 1137 select PARAVIRT 1138 help 1139 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1140 1141config FORCE_MAX_ZONEORDER 1142 int 1143 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 1144 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 1145 default "11" 1146 help 1147 The kernel memory allocator divides physically contiguous memory 1148 blocks into "zones", where each zone is a power of two number of 1149 pages. This option selects the largest power of two that the kernel 1150 keeps in the memory allocator. If you need to allocate very large 1151 blocks of physically contiguous memory, then you may need to 1152 increase this value. 1153 1154 This config option is actually maximum order plus one. For example, 1155 a value of 11 means that the largest free memory block is 2^10 pages. 1156 1157 We make sure that we can allocate upto a HugePage size for each configuration. 1158 Hence we have : 1159 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1160 1161 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1162 4M allocations matching the default size used by generic code. 1163 1164config UNMAP_KERNEL_AT_EL0 1165 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1166 default y 1167 help 1168 Speculation attacks against some high-performance processors can 1169 be used to bypass MMU permission checks and leak kernel data to 1170 userspace. This can be defended against by unmapping the kernel 1171 when running in userspace, mapping it back in on exception entry 1172 via a trampoline page in the vector table. 1173 1174 If unsure, say Y. 1175 1176config RODATA_FULL_DEFAULT_ENABLED 1177 bool "Apply r/o permissions of VM areas also to their linear aliases" 1178 default y 1179 help 1180 Apply read-only attributes of VM areas to the linear alias of 1181 the backing pages as well. This prevents code or read-only data 1182 from being modified (inadvertently or intentionally) via another 1183 mapping of the same memory page. This additional enhancement can 1184 be turned off at runtime by passing rodata=[off|on] (and turned on 1185 with rodata=full if this option is set to 'n') 1186 1187 This requires the linear region to be mapped down to pages, 1188 which may adversely affect performance in some cases. 1189 1190config ARM64_SW_TTBR0_PAN 1191 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1192 help 1193 Enabling this option prevents the kernel from accessing 1194 user-space memory directly by pointing TTBR0_EL1 to a reserved 1195 zeroed area and reserved ASID. The user access routines 1196 restore the valid TTBR0_EL1 temporarily. 1197 1198config ARM64_TAGGED_ADDR_ABI 1199 bool "Enable the tagged user addresses syscall ABI" 1200 default y 1201 help 1202 When this option is enabled, user applications can opt in to a 1203 relaxed ABI via prctl() allowing tagged addresses to be passed 1204 to system calls as pointer arguments. For details, see 1205 Documentation/arm64/tagged-address-abi.rst. 1206 1207menuconfig COMPAT 1208 bool "Kernel support for 32-bit EL0" 1209 depends on ARM64_4K_PAGES || EXPERT 1210 select COMPAT_BINFMT_ELF if BINFMT_ELF 1211 select HAVE_UID16 1212 select OLD_SIGSUSPEND3 1213 select COMPAT_OLD_SIGACTION 1214 help 1215 This option enables support for a 32-bit EL0 running under a 64-bit 1216 kernel at EL1. AArch32-specific components such as system calls, 1217 the user helper functions, VFP support and the ptrace interface are 1218 handled appropriately by the kernel. 1219 1220 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1221 that you will only be able to execute AArch32 binaries that were compiled 1222 with page size aligned segments. 1223 1224 If you want to execute 32-bit userspace applications, say Y. 1225 1226if COMPAT 1227 1228config KUSER_HELPERS 1229 bool "Enable kuser helpers page for 32-bit applications" 1230 default y 1231 help 1232 Warning: disabling this option may break 32-bit user programs. 1233 1234 Provide kuser helpers to compat tasks. The kernel provides 1235 helper code to userspace in read only form at a fixed location 1236 to allow userspace to be independent of the CPU type fitted to 1237 the system. This permits binaries to be run on ARMv4 through 1238 to ARMv8 without modification. 1239 1240 See Documentation/arm/kernel_user_helpers.rst for details. 1241 1242 However, the fixed address nature of these helpers can be used 1243 by ROP (return orientated programming) authors when creating 1244 exploits. 1245 1246 If all of the binaries and libraries which run on your platform 1247 are built specifically for your platform, and make no use of 1248 these helpers, then you can turn this option off to hinder 1249 such exploits. However, in that case, if a binary or library 1250 relying on those helpers is run, it will not function correctly. 1251 1252 Say N here only if you are absolutely certain that you do not 1253 need these helpers; otherwise, the safe option is to say Y. 1254 1255config COMPAT_VDSO 1256 bool "Enable vDSO for 32-bit applications" 1257 depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != "" 1258 select GENERIC_COMPAT_VDSO 1259 default y 1260 help 1261 Place in the process address space of 32-bit applications an 1262 ELF shared object providing fast implementations of gettimeofday 1263 and clock_gettime. 1264 1265 You must have a 32-bit build of glibc 2.22 or later for programs 1266 to seamlessly take advantage of this. 1267 1268config THUMB2_COMPAT_VDSO 1269 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1270 depends on COMPAT_VDSO 1271 default y 1272 help 1273 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1274 otherwise with '-marm'. 1275 1276menuconfig ARMV8_DEPRECATED 1277 bool "Emulate deprecated/obsolete ARMv8 instructions" 1278 depends on SYSCTL 1279 help 1280 Legacy software support may require certain instructions 1281 that have been deprecated or obsoleted in the architecture. 1282 1283 Enable this config to enable selective emulation of these 1284 features. 1285 1286 If unsure, say Y 1287 1288if ARMV8_DEPRECATED 1289 1290config SWP_EMULATION 1291 bool "Emulate SWP/SWPB instructions" 1292 help 1293 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1294 they are always undefined. Say Y here to enable software 1295 emulation of these instructions for userspace using LDXR/STXR. 1296 This feature can be controlled at runtime with the abi.swp 1297 sysctl which is disabled by default. 1298 1299 In some older versions of glibc [<=2.8] SWP is used during futex 1300 trylock() operations with the assumption that the code will not 1301 be preempted. This invalid assumption may be more likely to fail 1302 with SWP emulation enabled, leading to deadlock of the user 1303 application. 1304 1305 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1306 on an external transaction monitoring block called a global 1307 monitor to maintain update atomicity. If your system does not 1308 implement a global monitor, this option can cause programs that 1309 perform SWP operations to uncached memory to deadlock. 1310 1311 If unsure, say Y 1312 1313config CP15_BARRIER_EMULATION 1314 bool "Emulate CP15 Barrier instructions" 1315 help 1316 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1317 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1318 strongly recommended to use the ISB, DSB, and DMB 1319 instructions instead. 1320 1321 Say Y here to enable software emulation of these 1322 instructions for AArch32 userspace code. When this option is 1323 enabled, CP15 barrier usage is traced which can help 1324 identify software that needs updating. This feature can be 1325 controlled at runtime with the abi.cp15_barrier sysctl. 1326 1327 If unsure, say Y 1328 1329config SETEND_EMULATION 1330 bool "Emulate SETEND instruction" 1331 help 1332 The SETEND instruction alters the data-endianness of the 1333 AArch32 EL0, and is deprecated in ARMv8. 1334 1335 Say Y here to enable software emulation of the instruction 1336 for AArch32 userspace code. This feature can be controlled 1337 at runtime with the abi.setend sysctl. 1338 1339 Note: All the cpus on the system must have mixed endian support at EL0 1340 for this feature to be enabled. If a new CPU - which doesn't support mixed 1341 endian - is hotplugged in after this feature has been enabled, there could 1342 be unexpected results in the applications. 1343 1344 If unsure, say Y 1345endif 1346 1347endif 1348 1349menu "ARMv8.1 architectural features" 1350 1351config ARM64_HW_AFDBM 1352 bool "Support for hardware updates of the Access and Dirty page flags" 1353 default y 1354 help 1355 The ARMv8.1 architecture extensions introduce support for 1356 hardware updates of the access and dirty information in page 1357 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1358 capable processors, accesses to pages with PTE_AF cleared will 1359 set this bit instead of raising an access flag fault. 1360 Similarly, writes to read-only pages with the DBM bit set will 1361 clear the read-only bit (AP[2]) instead of raising a 1362 permission fault. 1363 1364 Kernels built with this configuration option enabled continue 1365 to work on pre-ARMv8.1 hardware and the performance impact is 1366 minimal. If unsure, say Y. 1367 1368config ARM64_PAN 1369 bool "Enable support for Privileged Access Never (PAN)" 1370 default y 1371 help 1372 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1373 prevents the kernel or hypervisor from accessing user-space (EL0) 1374 memory directly. 1375 1376 Choosing this option will cause any unprotected (not using 1377 copy_to_user et al) memory access to fail with a permission fault. 1378 1379 The feature is detected at runtime, and will remain as a 'nop' 1380 instruction if the cpu does not implement the feature. 1381 1382config ARM64_LSE_ATOMICS 1383 bool 1384 default ARM64_USE_LSE_ATOMICS 1385 depends on $(as-instr,.arch_extension lse) 1386 1387config ARM64_USE_LSE_ATOMICS 1388 bool "Atomic instructions" 1389 depends on JUMP_LABEL 1390 default y 1391 help 1392 As part of the Large System Extensions, ARMv8.1 introduces new 1393 atomic instructions that are designed specifically to scale in 1394 very large systems. 1395 1396 Say Y here to make use of these instructions for the in-kernel 1397 atomic routines. This incurs a small overhead on CPUs that do 1398 not support these instructions and requires the kernel to be 1399 built with binutils >= 2.25 in order for the new instructions 1400 to be used. 1401 1402config ARM64_VHE 1403 bool "Enable support for Virtualization Host Extensions (VHE)" 1404 default y 1405 help 1406 Virtualization Host Extensions (VHE) allow the kernel to run 1407 directly at EL2 (instead of EL1) on processors that support 1408 it. This leads to better performance for KVM, as they reduce 1409 the cost of the world switch. 1410 1411 Selecting this option allows the VHE feature to be detected 1412 at runtime, and does not affect processors that do not 1413 implement this feature. 1414 1415endmenu 1416 1417menu "ARMv8.2 architectural features" 1418 1419config ARM64_UAO 1420 bool "Enable support for User Access Override (UAO)" 1421 default y 1422 help 1423 User Access Override (UAO; part of the ARMv8.2 Extensions) 1424 causes the 'unprivileged' variant of the load/store instructions to 1425 be overridden to be privileged. 1426 1427 This option changes get_user() and friends to use the 'unprivileged' 1428 variant of the load/store instructions. This ensures that user-space 1429 really did have access to the supplied memory. When addr_limit is 1430 set to kernel memory the UAO bit will be set, allowing privileged 1431 access to kernel memory. 1432 1433 Choosing this option will cause copy_to_user() et al to use user-space 1434 memory permissions. 1435 1436 The feature is detected at runtime, the kernel will use the 1437 regular load/store instructions if the cpu does not implement the 1438 feature. 1439 1440config ARM64_PMEM 1441 bool "Enable support for persistent memory" 1442 select ARCH_HAS_PMEM_API 1443 select ARCH_HAS_UACCESS_FLUSHCACHE 1444 help 1445 Say Y to enable support for the persistent memory API based on the 1446 ARMv8.2 DCPoP feature. 1447 1448 The feature is detected at runtime, and the kernel will use DC CVAC 1449 operations if DC CVAP is not supported (following the behaviour of 1450 DC CVAP itself if the system does not define a point of persistence). 1451 1452config ARM64_RAS_EXTN 1453 bool "Enable support for RAS CPU Extensions" 1454 default y 1455 help 1456 CPUs that support the Reliability, Availability and Serviceability 1457 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1458 errors, classify them and report them to software. 1459 1460 On CPUs with these extensions system software can use additional 1461 barriers to determine if faults are pending and read the 1462 classification from a new set of registers. 1463 1464 Selecting this feature will allow the kernel to use these barriers 1465 and access the new registers if the system supports the extension. 1466 Platform RAS features may additionally depend on firmware support. 1467 1468config ARM64_CNP 1469 bool "Enable support for Common Not Private (CNP) translations" 1470 default y 1471 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1472 help 1473 Common Not Private (CNP) allows translation table entries to 1474 be shared between different PEs in the same inner shareable 1475 domain, so the hardware can use this fact to optimise the 1476 caching of such entries in the TLB. 1477 1478 Selecting this option allows the CNP feature to be detected 1479 at runtime, and does not affect PEs that do not implement 1480 this feature. 1481 1482endmenu 1483 1484menu "ARMv8.3 architectural features" 1485 1486config ARM64_PTR_AUTH 1487 bool "Enable support for pointer authentication" 1488 default y 1489 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1490 # Modern compilers insert a .note.gnu.property section note for PAC 1491 # which is only understood by binutils starting with version 2.33.1. 1492 depends on LD_IS_LLD || LD_VERSION >= 233010000 || (CC_IS_GCC && GCC_VERSION < 90100) 1493 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1494 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1495 help 1496 Pointer authentication (part of the ARMv8.3 Extensions) provides 1497 instructions for signing and authenticating pointers against secret 1498 keys, which can be used to mitigate Return Oriented Programming (ROP) 1499 and other attacks. 1500 1501 This option enables these instructions at EL0 (i.e. for userspace). 1502 Choosing this option will cause the kernel to initialise secret keys 1503 for each process at exec() time, with these keys being 1504 context-switched along with the process. 1505 1506 If the compiler supports the -mbranch-protection or 1507 -msign-return-address flag (e.g. GCC 7 or later), then this option 1508 will also cause the kernel itself to be compiled with return address 1509 protection. In this case, and if the target hardware is known to 1510 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1511 disabled with minimal loss of protection. 1512 1513 The feature is detected at runtime. If the feature is not present in 1514 hardware it will not be advertised to userspace/KVM guest nor will it 1515 be enabled. 1516 1517 If the feature is present on the boot CPU but not on a late CPU, then 1518 the late CPU will be parked. Also, if the boot CPU does not have 1519 address auth and the late CPU has then the late CPU will still boot 1520 but with the feature disabled. On such a system, this option should 1521 not be selected. 1522 1523 This feature works with FUNCTION_GRAPH_TRACER option only if 1524 DYNAMIC_FTRACE_WITH_REGS is enabled. 1525 1526config CC_HAS_BRANCH_PROT_PAC_RET 1527 # GCC 9 or later, clang 8 or later 1528 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1529 1530config CC_HAS_SIGN_RETURN_ADDRESS 1531 # GCC 7, 8 1532 def_bool $(cc-option,-msign-return-address=all) 1533 1534config AS_HAS_PAC 1535 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1536 1537config AS_HAS_CFI_NEGATE_RA_STATE 1538 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1539 1540endmenu 1541 1542menu "ARMv8.4 architectural features" 1543 1544config ARM64_AMU_EXTN 1545 bool "Enable support for the Activity Monitors Unit CPU extension" 1546 default y 1547 help 1548 The activity monitors extension is an optional extension introduced 1549 by the ARMv8.4 CPU architecture. This enables support for version 1 1550 of the activity monitors architecture, AMUv1. 1551 1552 To enable the use of this extension on CPUs that implement it, say Y. 1553 1554 Note that for architectural reasons, firmware _must_ implement AMU 1555 support when running on CPUs that present the activity monitors 1556 extension. The required support is present in: 1557 * Version 1.5 and later of the ARM Trusted Firmware 1558 1559 For kernels that have this configuration enabled but boot with broken 1560 firmware, you may need to say N here until the firmware is fixed. 1561 Otherwise you may experience firmware panics or lockups when 1562 accessing the counter registers. Even if you are not observing these 1563 symptoms, the values returned by the register reads might not 1564 correctly reflect reality. Most commonly, the value read will be 0, 1565 indicating that the counter is not enabled. 1566 1567config AS_HAS_ARMV8_4 1568 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1569 1570config ARM64_TLB_RANGE 1571 bool "Enable support for tlbi range feature" 1572 default y 1573 depends on AS_HAS_ARMV8_4 1574 help 1575 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1576 range of input addresses. 1577 1578 The feature introduces new assembly instructions, and they were 1579 support when binutils >= 2.30. 1580 1581endmenu 1582 1583menu "ARMv8.5 architectural features" 1584 1585config ARM64_BTI 1586 bool "Branch Target Identification support" 1587 default y 1588 help 1589 Branch Target Identification (part of the ARMv8.5 Extensions) 1590 provides a mechanism to limit the set of locations to which computed 1591 branch instructions such as BR or BLR can jump. 1592 1593 To make use of BTI on CPUs that support it, say Y. 1594 1595 BTI is intended to provide complementary protection to other control 1596 flow integrity protection mechanisms, such as the Pointer 1597 authentication mechanism provided as part of the ARMv8.3 Extensions. 1598 For this reason, it does not make sense to enable this option without 1599 also enabling support for pointer authentication. Thus, when 1600 enabling this option you should also select ARM64_PTR_AUTH=y. 1601 1602 Userspace binaries must also be specifically compiled to make use of 1603 this mechanism. If you say N here or the hardware does not support 1604 BTI, such binaries can still run, but you get no additional 1605 enforcement of branch destinations. 1606 1607config ARM64_BTI_KERNEL 1608 bool "Use Branch Target Identification for kernel" 1609 default y 1610 depends on ARM64_BTI 1611 depends on ARM64_PTR_AUTH 1612 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1613 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1614 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1615 depends on !(CC_IS_CLANG && GCOV_KERNEL) 1616 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1617 help 1618 Build the kernel with Branch Target Identification annotations 1619 and enable enforcement of this for kernel code. When this option 1620 is enabled and the system supports BTI all kernel code including 1621 modular code must have BTI enabled. 1622 1623config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1624 # GCC 9 or later, clang 8 or later 1625 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1626 1627config ARM64_E0PD 1628 bool "Enable support for E0PD" 1629 default y 1630 help 1631 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1632 that EL0 accesses made via TTBR1 always fault in constant time, 1633 providing similar benefits to KASLR as those provided by KPTI, but 1634 with lower overhead and without disrupting legitimate access to 1635 kernel memory such as SPE. 1636 1637 This option enables E0PD for TTBR1 where available. 1638 1639config ARCH_RANDOM 1640 bool "Enable support for random number generation" 1641 default y 1642 help 1643 Random number generation (part of the ARMv8.5 Extensions) 1644 provides a high bandwidth, cryptographically secure 1645 hardware random number generator. 1646 1647config ARM64_AS_HAS_MTE 1648 # Initial support for MTE went in binutils 2.32.0, checked with 1649 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1650 # as a late addition to the final architecture spec (LDGM/STGM) 1651 # is only supported in the newer 2.32.x and 2.33 binutils 1652 # versions, hence the extra "stgm" instruction check below. 1653 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1654 1655config ARM64_MTE 1656 bool "Memory Tagging Extension support" 1657 default y 1658 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1659 select ARCH_USES_HIGH_VMA_FLAGS 1660 help 1661 Memory Tagging (part of the ARMv8.5 Extensions) provides 1662 architectural support for run-time, always-on detection of 1663 various classes of memory error to aid with software debugging 1664 to eliminate vulnerabilities arising from memory-unsafe 1665 languages. 1666 1667 This option enables the support for the Memory Tagging 1668 Extension at EL0 (i.e. for userspace). 1669 1670 Selecting this option allows the feature to be detected at 1671 runtime. Any secondary CPU not implementing this feature will 1672 not be allowed a late bring-up. 1673 1674 Userspace binaries that want to use this feature must 1675 explicitly opt in. The mechanism for the userspace is 1676 described in: 1677 1678 Documentation/arm64/memory-tagging-extension.rst. 1679 1680endmenu 1681 1682config ARM64_SVE 1683 bool "ARM Scalable Vector Extension support" 1684 default y 1685 depends on !KVM || ARM64_VHE 1686 help 1687 The Scalable Vector Extension (SVE) is an extension to the AArch64 1688 execution state which complements and extends the SIMD functionality 1689 of the base architecture to support much larger vectors and to enable 1690 additional vectorisation opportunities. 1691 1692 To enable use of this extension on CPUs that implement it, say Y. 1693 1694 On CPUs that support the SVE2 extensions, this option will enable 1695 those too. 1696 1697 Note that for architectural reasons, firmware _must_ implement SVE 1698 support when running on SVE capable hardware. The required support 1699 is present in: 1700 1701 * version 1.5 and later of the ARM Trusted Firmware 1702 * the AArch64 boot wrapper since commit 5e1261e08abf 1703 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1704 1705 For other firmware implementations, consult the firmware documentation 1706 or vendor. 1707 1708 If you need the kernel to boot on SVE-capable hardware with broken 1709 firmware, you may need to say N here until you get your firmware 1710 fixed. Otherwise, you may experience firmware panics or lockups when 1711 booting the kernel. If unsure and you are not observing these 1712 symptoms, you should assume that it is safe to say Y. 1713 1714 CPUs that support SVE are architecturally required to support the 1715 Virtualization Host Extensions (VHE), so the kernel makes no 1716 provision for supporting SVE alongside KVM without VHE enabled. 1717 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1718 KVM in the same kernel image. 1719 1720config ARM64_MODULE_PLTS 1721 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1722 depends on MODULES 1723 select HAVE_MOD_ARCH_SPECIFIC 1724 help 1725 Allocate PLTs when loading modules so that jumps and calls whose 1726 targets are too far away for their relative offsets to be encoded 1727 in the instructions themselves can be bounced via veneers in the 1728 module's PLT. This allows modules to be allocated in the generic 1729 vmalloc area after the dedicated module memory area has been 1730 exhausted. 1731 1732 When running with address space randomization (KASLR), the module 1733 region itself may be too far away for ordinary relative jumps and 1734 calls, and so in that case, module PLTs are required and cannot be 1735 disabled. 1736 1737 Specific errata workaround(s) might also force module PLTs to be 1738 enabled (ARM64_ERRATUM_843419). 1739 1740config ARM64_PSEUDO_NMI 1741 bool "Support for NMI-like interrupts" 1742 select ARM_GIC_V3 1743 help 1744 Adds support for mimicking Non-Maskable Interrupts through the use of 1745 GIC interrupt priority. This support requires version 3 or later of 1746 ARM GIC. 1747 1748 This high priority configuration for interrupts needs to be 1749 explicitly enabled by setting the kernel parameter 1750 "irqchip.gicv3_pseudo_nmi" to 1. 1751 1752 If unsure, say N 1753 1754if ARM64_PSEUDO_NMI 1755config ARM64_DEBUG_PRIORITY_MASKING 1756 bool "Debug interrupt priority masking" 1757 help 1758 This adds runtime checks to functions enabling/disabling 1759 interrupts when using priority masking. The additional checks verify 1760 the validity of ICC_PMR_EL1 when calling concerned functions. 1761 1762 If unsure, say N 1763endif 1764 1765config RELOCATABLE 1766 bool "Build a relocatable kernel image" if EXPERT 1767 select ARCH_HAS_RELR 1768 default y 1769 help 1770 This builds the kernel as a Position Independent Executable (PIE), 1771 which retains all relocation metadata required to relocate the 1772 kernel binary at runtime to a different virtual address than the 1773 address it was linked at. 1774 Since AArch64 uses the RELA relocation format, this requires a 1775 relocation pass at runtime even if the kernel is loaded at the 1776 same address it was linked at. 1777 1778config RANDOMIZE_BASE 1779 bool "Randomize the address of the kernel image" 1780 select ARM64_MODULE_PLTS if MODULES 1781 select RELOCATABLE 1782 help 1783 Randomizes the virtual address at which the kernel image is 1784 loaded, as a security feature that deters exploit attempts 1785 relying on knowledge of the location of kernel internals. 1786 1787 It is the bootloader's job to provide entropy, by passing a 1788 random u64 value in /chosen/kaslr-seed at kernel entry. 1789 1790 When booting via the UEFI stub, it will invoke the firmware's 1791 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1792 to the kernel proper. In addition, it will randomise the physical 1793 location of the kernel Image as well. 1794 1795 If unsure, say N. 1796 1797config RANDOMIZE_MODULE_REGION_FULL 1798 bool "Randomize the module region over a 4 GB range" 1799 depends on RANDOMIZE_BASE 1800 default y 1801 help 1802 Randomizes the location of the module region inside a 4 GB window 1803 covering the core kernel. This way, it is less likely for modules 1804 to leak information about the location of core kernel data structures 1805 but it does imply that function calls between modules and the core 1806 kernel will need to be resolved via veneers in the module PLT. 1807 1808 When this option is not set, the module region will be randomized over 1809 a limited range that contains the [_stext, _etext] interval of the 1810 core kernel, so branch relocations are always in range. 1811 1812config CC_HAVE_STACKPROTECTOR_SYSREG 1813 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1814 1815config STACKPROTECTOR_PER_TASK 1816 def_bool y 1817 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1818 1819endmenu 1820 1821menu "Boot options" 1822 1823config ARM64_ACPI_PARKING_PROTOCOL 1824 bool "Enable support for the ARM64 ACPI parking protocol" 1825 depends on ACPI 1826 help 1827 Enable support for the ARM64 ACPI parking protocol. If disabled 1828 the kernel will not allow booting through the ARM64 ACPI parking 1829 protocol even if the corresponding data is present in the ACPI 1830 MADT table. 1831 1832config CMDLINE 1833 string "Default kernel command string" 1834 default "" 1835 help 1836 Provide a set of default command-line options at build time by 1837 entering them here. As a minimum, you should specify the the 1838 root device (e.g. root=/dev/nfs). 1839 1840config CMDLINE_FORCE 1841 bool "Always use the default kernel command string" 1842 depends on CMDLINE != "" 1843 help 1844 Always use the default kernel command string, even if the boot 1845 loader passes other arguments to the kernel. 1846 This is useful if you cannot or don't want to change the 1847 command-line options your boot loader passes to the kernel. 1848 1849config EFI_STUB 1850 bool 1851 1852config EFI 1853 bool "UEFI runtime support" 1854 depends on OF && !CPU_BIG_ENDIAN 1855 depends on KERNEL_MODE_NEON 1856 select ARCH_SUPPORTS_ACPI 1857 select LIBFDT 1858 select UCS2_STRING 1859 select EFI_PARAMS_FROM_FDT 1860 select EFI_RUNTIME_WRAPPERS 1861 select EFI_STUB 1862 select EFI_GENERIC_STUB 1863 default y 1864 help 1865 This option provides support for runtime services provided 1866 by UEFI firmware (such as non-volatile variables, realtime 1867 clock, and platform reset). A UEFI stub is also provided to 1868 allow the kernel to be booted as an EFI application. This 1869 is only useful on systems that have UEFI firmware. 1870 1871config DMI 1872 bool "Enable support for SMBIOS (DMI) tables" 1873 depends on EFI 1874 default y 1875 help 1876 This enables SMBIOS/DMI feature for systems. 1877 1878 This option is only useful on systems that have UEFI firmware. 1879 However, even with this option, the resultant kernel should 1880 continue to boot on existing non-UEFI platforms. 1881 1882endmenu 1883 1884config SYSVIPC_COMPAT 1885 def_bool y 1886 depends on COMPAT && SYSVIPC 1887 1888config ARCH_ENABLE_HUGEPAGE_MIGRATION 1889 def_bool y 1890 depends on HUGETLB_PAGE && MIGRATION 1891 1892config ARCH_ENABLE_THP_MIGRATION 1893 def_bool y 1894 depends on TRANSPARENT_HUGEPAGE 1895 1896menu "Power management options" 1897 1898source "kernel/power/Kconfig" 1899 1900config ARCH_HIBERNATION_POSSIBLE 1901 def_bool y 1902 depends on CPU_PM 1903 1904config ARCH_HIBERNATION_HEADER 1905 def_bool y 1906 depends on HIBERNATION 1907 1908config ARCH_SUSPEND_POSSIBLE 1909 def_bool y 1910 1911endmenu 1912 1913menu "CPU Power Management" 1914 1915source "drivers/cpuidle/Kconfig" 1916 1917source "drivers/cpufreq/Kconfig" 1918 1919endmenu 1920 1921source "drivers/firmware/Kconfig" 1922 1923source "drivers/acpi/Kconfig" 1924 1925source "arch/arm64/kvm/Kconfig" 1926 1927if CRYPTO 1928source "arch/arm64/crypto/Kconfig" 1929endif 1930