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_CLOCKSOURCE_DATA 13 select ARCH_HAS_DEBUG_VIRTUAL 14 select ARCH_HAS_DEVMEM_IS_ALLOWED 15 select ARCH_HAS_DMA_COHERENT_TO_PFN 16 select ARCH_HAS_DMA_PREP_COHERENT 17 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 18 select ARCH_HAS_FAST_MULTIPLIER 19 select ARCH_HAS_FORTIFY_SOURCE 20 select ARCH_HAS_GCOV_PROFILE_ALL 21 select ARCH_HAS_GIGANTIC_PAGE 22 select ARCH_HAS_KCOV 23 select ARCH_HAS_KEEPINITRD 24 select ARCH_HAS_MEMBARRIER_SYNC_CORE 25 select ARCH_HAS_PTE_DEVMAP 26 select ARCH_HAS_PTE_SPECIAL 27 select ARCH_HAS_SETUP_DMA_OPS 28 select ARCH_HAS_SET_DIRECT_MAP 29 select ARCH_HAS_SET_MEMORY 30 select ARCH_HAS_STRICT_KERNEL_RWX 31 select ARCH_HAS_STRICT_MODULE_RWX 32 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 33 select ARCH_HAS_SYNC_DMA_FOR_CPU 34 select ARCH_HAS_SYSCALL_WRAPPER 35 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 36 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 37 select ARCH_HAVE_NMI_SAFE_CMPXCHG 38 select ARCH_INLINE_READ_LOCK if !PREEMPT 39 select ARCH_INLINE_READ_LOCK_BH if !PREEMPT 40 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT 41 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT 42 select ARCH_INLINE_READ_UNLOCK if !PREEMPT 43 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT 44 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT 45 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT 46 select ARCH_INLINE_WRITE_LOCK if !PREEMPT 47 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT 48 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT 49 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT 50 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT 51 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT 52 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT 53 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT 54 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPT 55 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPT 56 select ARCH_INLINE_SPIN_LOCK if !PREEMPT 57 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPT 58 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPT 59 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPT 60 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPT 61 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT 62 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT 63 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT 64 select ARCH_KEEP_MEMBLOCK 65 select ARCH_USE_CMPXCHG_LOCKREF 66 select ARCH_USE_QUEUED_RWLOCKS 67 select ARCH_USE_QUEUED_SPINLOCKS 68 select ARCH_SUPPORTS_MEMORY_FAILURE 69 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 70 select ARCH_SUPPORTS_LTO_CLANG 71 select ARCH_SUPPORTS_THINLTO 72 select ARCH_SUPPORTS_ATOMIC_RMW 73 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG 74 select ARCH_SUPPORTS_NUMA_BALANCING 75 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 76 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 77 select ARCH_WANT_FRAME_POINTERS 78 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 79 select ARCH_HAS_UBSAN_SANITIZE_ALL 80 select ARM_AMBA 81 select ARM_ARCH_TIMER 82 select ARM_GIC 83 select AUDIT_ARCH_COMPAT_GENERIC 84 select ARM_GIC_V2M if PCI 85 select ARM_GIC_V3 86 select ARM_GIC_V3_ITS if PCI 87 select ARM_PSCI_FW 88 select BUILDTIME_EXTABLE_SORT 89 select CLONE_BACKWARDS 90 select COMMON_CLK 91 select CPU_PM if (SUSPEND || CPU_IDLE) 92 select CRC32 93 select DCACHE_WORD_ACCESS 94 select DMA_DIRECT_REMAP 95 select EDAC_SUPPORT 96 select FRAME_POINTER 97 select GENERIC_ALLOCATOR 98 select GENERIC_ARCH_TOPOLOGY 99 select GENERIC_CLOCKEVENTS 100 select GENERIC_CLOCKEVENTS_BROADCAST 101 select GENERIC_CPU_AUTOPROBE 102 select GENERIC_CPU_VULNERABILITIES 103 select GENERIC_EARLY_IOREMAP 104 select GENERIC_IDLE_POLL_SETUP 105 select GENERIC_IRQ_MULTI_HANDLER 106 select GENERIC_IRQ_PROBE 107 select GENERIC_IRQ_SHOW 108 select GENERIC_IRQ_SHOW_LEVEL 109 select GENERIC_PCI_IOMAP 110 select GENERIC_SCHED_CLOCK 111 select GENERIC_SMP_IDLE_THREAD 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select GENERIC_TIME_VSYSCALL 115 select GENERIC_GETTIMEOFDAY 116 select HANDLE_DOMAIN_IRQ 117 select HARDIRQS_SW_RESEND 118 select HAVE_PCI 119 select HAVE_ACPI_APEI if (ACPI && EFI) 120 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 121 select HAVE_ARCH_AUDITSYSCALL 122 select HAVE_ARCH_BITREVERSE 123 select HAVE_ARCH_HUGE_VMAP 124 select HAVE_ARCH_JUMP_LABEL 125 select HAVE_ARCH_JUMP_LABEL_RELATIVE 126 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 127 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 128 select HAVE_ARCH_KGDB 129 select HAVE_ARCH_MMAP_RND_BITS 130 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 131 select HAVE_ARCH_PREL32_RELOCATIONS if !LTO_CLANG 132 select HAVE_ARCH_SECCOMP_FILTER 133 select HAVE_ARCH_STACKLEAK 134 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 135 select HAVE_ARCH_TRACEHOOK 136 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 137 select HAVE_ARCH_VMAP_STACK 138 select HAVE_ARM_SMCCC 139 select HAVE_ASM_MODVERSIONS 140 select HAVE_EBPF_JIT 141 select HAVE_C_RECORDMCOUNT 142 select HAVE_CMPXCHG_DOUBLE 143 select HAVE_CMPXCHG_LOCAL 144 select HAVE_CONTEXT_TRACKING 145 select HAVE_COPY_THREAD_TLS 146 select HAVE_DEBUG_BUGVERBOSE 147 select HAVE_DEBUG_KMEMLEAK 148 select HAVE_DMA_CONTIGUOUS 149 select HAVE_DYNAMIC_FTRACE 150 select HAVE_EFFICIENT_UNALIGNED_ACCESS 151 select HAVE_FAST_GUP 152 select HAVE_FTRACE_MCOUNT_RECORD 153 select HAVE_FUNCTION_TRACER 154 select HAVE_FUNCTION_ERROR_INJECTION 155 select HAVE_FUNCTION_GRAPH_TRACER if !SHADOW_CALL_STACK 156 select HAVE_GCC_PLUGINS 157 select HAVE_HW_BREAKPOINT if PERF_EVENTS 158 select HAVE_IRQ_TIME_ACCOUNTING 159 select HAVE_MEMBLOCK_NODE_MAP if NUMA 160 select HAVE_NMI 161 select HAVE_PATA_PLATFORM 162 select HAVE_PERF_EVENTS 163 select HAVE_PERF_REGS 164 select HAVE_PERF_USER_STACK_DUMP 165 select HAVE_REGS_AND_STACK_ACCESS_API 166 select HAVE_FUNCTION_ARG_ACCESS_API 167 select HAVE_RCU_TABLE_FREE 168 select HAVE_RSEQ 169 select HAVE_STACKPROTECTOR 170 select HAVE_SYSCALL_TRACEPOINTS 171 select HAVE_KPROBES 172 select HAVE_KRETPROBES 173 select HAVE_GENERIC_VDSO 174 select IOMMU_DMA if IOMMU_SUPPORT 175 select IRQ_DOMAIN 176 select IRQ_FORCED_THREADING 177 select MODULES_USE_ELF_RELA 178 select NEED_DMA_MAP_STATE 179 select NEED_SG_DMA_LENGTH 180 select OF 181 select OF_EARLY_FLATTREE 182 select PCI_DOMAINS_GENERIC if PCI 183 select PCI_ECAM if (ACPI && PCI) 184 select PCI_SYSCALL if PCI 185 select POWER_RESET 186 select POWER_SUPPLY 187 select SPARSE_IRQ 188 select SWIOTLB 189 select SYSCTL_EXCEPTION_TRACE 190 select THREAD_INFO_IN_TASK 191 help 192 ARM 64-bit (AArch64) Linux support. 193 194config 64BIT 195 def_bool y 196 197config MMU 198 def_bool y 199 200config ARM64_PAGE_SHIFT 201 int 202 default 16 if ARM64_64K_PAGES 203 default 14 if ARM64_16K_PAGES 204 default 12 205 206config ARM64_CONT_SHIFT 207 int 208 default 5 if ARM64_64K_PAGES 209 default 7 if ARM64_16K_PAGES 210 default 4 211 212config ARCH_MMAP_RND_BITS_MIN 213 default 14 if ARM64_64K_PAGES 214 default 16 if ARM64_16K_PAGES 215 default 18 216 217# max bits determined by the following formula: 218# VA_BITS - PAGE_SHIFT - 3 219config ARCH_MMAP_RND_BITS_MAX 220 default 19 if ARM64_VA_BITS=36 221 default 24 if ARM64_VA_BITS=39 222 default 27 if ARM64_VA_BITS=42 223 default 30 if ARM64_VA_BITS=47 224 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 225 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 226 default 33 if ARM64_VA_BITS=48 227 default 14 if ARM64_64K_PAGES 228 default 16 if ARM64_16K_PAGES 229 default 18 230 231config ARCH_MMAP_RND_COMPAT_BITS_MIN 232 default 7 if ARM64_64K_PAGES 233 default 9 if ARM64_16K_PAGES 234 default 11 235 236config ARCH_MMAP_RND_COMPAT_BITS_MAX 237 default 16 238 239config NO_IOPORT_MAP 240 def_bool y if !PCI 241 242config STACKTRACE_SUPPORT 243 def_bool y 244 245config ILLEGAL_POINTER_VALUE 246 hex 247 default 0xdead000000000000 248 249config LOCKDEP_SUPPORT 250 def_bool y 251 252config TRACE_IRQFLAGS_SUPPORT 253 def_bool y 254 255config GENERIC_BUG 256 def_bool y 257 depends on BUG 258 259config GENERIC_BUG_RELATIVE_POINTERS 260 def_bool y 261 depends on GENERIC_BUG 262 263config GENERIC_HWEIGHT 264 def_bool y 265 266config GENERIC_CSUM 267 def_bool y 268 269config GENERIC_CALIBRATE_DELAY 270 def_bool y 271 272config ZONE_DMA32 273 bool "Support DMA32 zone" if EXPERT 274 default y 275 276config ARCH_ENABLE_MEMORY_HOTPLUG 277 def_bool y 278 279config SMP 280 def_bool y 281 282config KERNEL_MODE_NEON 283 def_bool y 284 285config FIX_EARLYCON_MEM 286 def_bool y 287 288config PGTABLE_LEVELS 289 int 290 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 291 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 292 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 293 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 294 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 295 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 296 297config ARCH_SUPPORTS_UPROBES 298 def_bool y 299 300config ARCH_PROC_KCORE_TEXT 301 def_bool y 302 303config KASAN_SHADOW_OFFSET 304 hex 305 depends on KASAN 306 default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 307 default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 308 default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 309 default 0xdfffffd000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 310 default 0xdffffffa00000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 311 default 0xefff900000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 312 default 0xefffc80000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 313 default 0xeffffe4000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 314 default 0xefffffc800000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 315 default 0xeffffff900000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 316 default 0xffffffffffffffff 317 318source "arch/arm64/Kconfig.platforms" 319 320menu "Kernel Features" 321 322menu "ARM errata workarounds via the alternatives framework" 323 324config ARM64_WORKAROUND_CLEAN_CACHE 325 bool 326 327config ARM64_ERRATUM_826319 328 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 329 default y 330 select ARM64_WORKAROUND_CLEAN_CACHE 331 help 332 This option adds an alternative code sequence to work around ARM 333 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 334 AXI master interface and an L2 cache. 335 336 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 337 and is unable to accept a certain write via this interface, it will 338 not progress on read data presented on the read data channel and the 339 system can deadlock. 340 341 The workaround promotes data cache clean instructions to 342 data cache clean-and-invalidate. 343 Please note that this does not necessarily enable the workaround, 344 as it depends on the alternative framework, which will only patch 345 the kernel if an affected CPU is detected. 346 347 If unsure, say Y. 348 349config ARM64_ERRATUM_827319 350 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 351 default y 352 select ARM64_WORKAROUND_CLEAN_CACHE 353 help 354 This option adds an alternative code sequence to work around ARM 355 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 356 master interface and an L2 cache. 357 358 Under certain conditions this erratum can cause a clean line eviction 359 to occur at the same time as another transaction to the same address 360 on the AMBA 5 CHI interface, which can cause data corruption if the 361 interconnect reorders the two transactions. 362 363 The workaround promotes data cache clean instructions to 364 data cache clean-and-invalidate. 365 Please note that this does not necessarily enable the workaround, 366 as it depends on the alternative framework, which will only patch 367 the kernel if an affected CPU is detected. 368 369 If unsure, say Y. 370 371config ARM64_ERRATUM_824069 372 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 373 default y 374 select ARM64_WORKAROUND_CLEAN_CACHE 375 help 376 This option adds an alternative code sequence to work around ARM 377 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 378 to a coherent interconnect. 379 380 If a Cortex-A53 processor is executing a store or prefetch for 381 write instruction at the same time as a processor in another 382 cluster is executing a cache maintenance operation to the same 383 address, then this erratum might cause a clean cache line to be 384 incorrectly marked as dirty. 385 386 The workaround promotes data cache clean instructions to 387 data cache clean-and-invalidate. 388 Please note that this option does not necessarily enable the 389 workaround, as it depends on the alternative framework, which will 390 only patch the kernel if an affected CPU is detected. 391 392 If unsure, say Y. 393 394config ARM64_ERRATUM_819472 395 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 396 default y 397 select ARM64_WORKAROUND_CLEAN_CACHE 398 help 399 This option adds an alternative code sequence to work around ARM 400 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 401 present when it is connected to a coherent interconnect. 402 403 If the processor is executing a load and store exclusive sequence at 404 the same time as a processor in another cluster is executing a cache 405 maintenance operation to the same address, then this erratum might 406 cause data corruption. 407 408 The workaround promotes data cache clean instructions to 409 data cache clean-and-invalidate. 410 Please note that this does not necessarily enable the workaround, 411 as it depends on the alternative framework, which will only patch 412 the kernel if an affected CPU is detected. 413 414 If unsure, say Y. 415 416config ARM64_ERRATUM_832075 417 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 418 default y 419 help 420 This option adds an alternative code sequence to work around ARM 421 erratum 832075 on Cortex-A57 parts up to r1p2. 422 423 Affected Cortex-A57 parts might deadlock when exclusive load/store 424 instructions to Write-Back memory are mixed with Device loads. 425 426 The workaround is to promote device loads to use Load-Acquire 427 semantics. 428 Please note that this does not necessarily enable the workaround, 429 as it depends on the alternative framework, which will only patch 430 the kernel if an affected CPU is detected. 431 432 If unsure, say Y. 433 434config ARM64_ERRATUM_834220 435 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 436 depends on KVM 437 default y 438 help 439 This option adds an alternative code sequence to work around ARM 440 erratum 834220 on Cortex-A57 parts up to r1p2. 441 442 Affected Cortex-A57 parts might report a Stage 2 translation 443 fault as the result of a Stage 1 fault for load crossing a 444 page boundary when there is a permission or device memory 445 alignment fault at Stage 1 and a translation fault at Stage 2. 446 447 The workaround is to verify that the Stage 1 translation 448 doesn't generate a fault before handling the Stage 2 fault. 449 Please note that this does not necessarily enable the workaround, 450 as it depends on the alternative framework, which will only patch 451 the kernel if an affected CPU is detected. 452 453 If unsure, say Y. 454 455config ARM64_ERRATUM_845719 456 bool "Cortex-A53: 845719: a load might read incorrect data" 457 depends on COMPAT 458 default y 459 help 460 This option adds an alternative code sequence to work around ARM 461 erratum 845719 on Cortex-A53 parts up to r0p4. 462 463 When running a compat (AArch32) userspace on an affected Cortex-A53 464 part, a load at EL0 from a virtual address that matches the bottom 32 465 bits of the virtual address used by a recent load at (AArch64) EL1 466 might return incorrect data. 467 468 The workaround is to write the contextidr_el1 register on exception 469 return to a 32-bit task. 470 Please note that this does not necessarily enable the workaround, 471 as it depends on the alternative framework, which will only patch 472 the kernel if an affected CPU is detected. 473 474 If unsure, say Y. 475 476config ARM64_ERRATUM_843419 477 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 478 default y 479 select ARM64_MODULE_PLTS if MODULES 480 help 481 This option links the kernel with '--fix-cortex-a53-843419' and 482 enables PLT support to replace certain ADRP instructions, which can 483 cause subsequent memory accesses to use an incorrect address on 484 Cortex-A53 parts up to r0p4. 485 486 If unsure, say Y. 487 488config ARM64_ERRATUM_1024718 489 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 490 default y 491 help 492 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 493 494 Affected Cortex-A55 cores (all revisions) could cause incorrect 495 update of the hardware dirty bit when the DBM/AP bits are updated 496 without a break-before-make. The workaround is to disable the usage 497 of hardware DBM locally on the affected cores. CPUs not affected by 498 this erratum will continue to use the feature. 499 500 If unsure, say Y. 501 502config ARM64_ERRATUM_1418040 503 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 504 default y 505 depends on COMPAT 506 help 507 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 508 errata 1188873 and 1418040. 509 510 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 511 cause register corruption when accessing the timer registers 512 from AArch32 userspace. 513 514 If unsure, say Y. 515 516config ARM64_ERRATUM_1165522 517 bool "Cortex-A76: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 518 default y 519 help 520 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 521 522 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 523 corrupted TLBs by speculating an AT instruction during a guest 524 context switch. 525 526 If unsure, say Y. 527 528config ARM64_ERRATUM_1286807 529 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 530 default y 531 select ARM64_WORKAROUND_REPEAT_TLBI 532 help 533 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 534 535 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 536 address for a cacheable mapping of a location is being 537 accessed by a core while another core is remapping the virtual 538 address to a new physical page using the recommended 539 break-before-make sequence, then under very rare circumstances 540 TLBI+DSB completes before a read using the translation being 541 invalidated has been observed by other observers. The 542 workaround repeats the TLBI+DSB operation. 543 544 If unsure, say Y. 545 546config ARM64_ERRATUM_1463225 547 bool "Cortex-A76: Software Step might prevent interrupt recognition" 548 default y 549 help 550 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 551 552 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 553 of a system call instruction (SVC) can prevent recognition of 554 subsequent interrupts when software stepping is disabled in the 555 exception handler of the system call and either kernel debugging 556 is enabled or VHE is in use. 557 558 Work around the erratum by triggering a dummy step exception 559 when handling a system call from a task that is being stepped 560 in a VHE configuration of the kernel. 561 562 If unsure, say Y. 563 564config ARM64_ERRATUM_1542419 565 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 566 default y 567 help 568 This option adds a workaround for ARM Neoverse-N1 erratum 569 1542419. 570 571 Affected Neoverse-N1 cores could execute a stale instruction when 572 modified by another CPU. The workaround depends on a firmware 573 counterpart. 574 575 Workaround the issue by hiding the DIC feature from EL0. This 576 forces user-space to perform cache maintenance. 577 578 If unsure, say Y. 579 580config ARM64_ERRATUM_1742098 581 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 582 depends on COMPAT 583 default y 584 help 585 This option removes the AES hwcap for aarch32 user-space to 586 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 587 588 Affected parts may corrupt the AES state if an interrupt is 589 taken between a pair of AES instructions. These instructions 590 are only present if the cryptography extensions are present. 591 All software should have a fallback implementation for CPUs 592 that don't implement the cryptography extensions. 593 594 If unsure, say Y. 595 596config CAVIUM_ERRATUM_22375 597 bool "Cavium erratum 22375, 24313" 598 default y 599 help 600 Enable workaround for errata 22375 and 24313. 601 602 This implements two gicv3-its errata workarounds for ThunderX. Both 603 with a small impact affecting only ITS table allocation. 604 605 erratum 22375: only alloc 8MB table size 606 erratum 24313: ignore memory access type 607 608 The fixes are in ITS initialization and basically ignore memory access 609 type and table size provided by the TYPER and BASER registers. 610 611 If unsure, say Y. 612 613config CAVIUM_ERRATUM_23144 614 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 615 depends on NUMA 616 default y 617 help 618 ITS SYNC command hang for cross node io and collections/cpu mapping. 619 620 If unsure, say Y. 621 622config CAVIUM_ERRATUM_23154 623 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 624 default y 625 help 626 The gicv3 of ThunderX requires a modified version for 627 reading the IAR status to ensure data synchronization 628 (access to icc_iar1_el1 is not sync'ed before and after). 629 630 If unsure, say Y. 631 632config CAVIUM_ERRATUM_27456 633 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 634 default y 635 help 636 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 637 instructions may cause the icache to become corrupted if it 638 contains data for a non-current ASID. The fix is to 639 invalidate the icache when changing the mm context. 640 641 If unsure, say Y. 642 643config CAVIUM_ERRATUM_30115 644 bool "Cavium erratum 30115: Guest may disable interrupts in host" 645 default y 646 help 647 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 648 1.2, and T83 Pass 1.0, KVM guest execution may disable 649 interrupts in host. Trapping both GICv3 group-0 and group-1 650 accesses sidesteps the issue. 651 652 If unsure, say Y. 653 654config CAVIUM_TX2_ERRATUM_219 655 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 656 default y 657 help 658 On Cavium ThunderX2, a load, store or prefetch instruction between a 659 TTBR update and the corresponding context synchronizing operation can 660 cause a spurious Data Abort to be delivered to any hardware thread in 661 the CPU core. 662 663 Work around the issue by avoiding the problematic code sequence and 664 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 665 trap handler performs the corresponding register access, skips the 666 instruction and ensures context synchronization by virtue of the 667 exception return. 668 669 If unsure, say Y. 670 671config QCOM_FALKOR_ERRATUM_1003 672 bool "Falkor E1003: Incorrect translation due to ASID change" 673 default y 674 help 675 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 676 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 677 in TTBR1_EL1, this situation only occurs in the entry trampoline and 678 then only for entries in the walk cache, since the leaf translation 679 is unchanged. Work around the erratum by invalidating the walk cache 680 entries for the trampoline before entering the kernel proper. 681 682config ARM64_WORKAROUND_REPEAT_TLBI 683 bool 684 685config QCOM_FALKOR_ERRATUM_1009 686 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 687 default y 688 select ARM64_WORKAROUND_REPEAT_TLBI 689 help 690 On Falkor v1, the CPU may prematurely complete a DSB following a 691 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 692 one more time to fix the issue. 693 694 If unsure, say Y. 695 696config QCOM_QDF2400_ERRATUM_0065 697 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 698 default y 699 help 700 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 701 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 702 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 703 704 If unsure, say Y. 705 706config SOCIONEXT_SYNQUACER_PREITS 707 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 708 default y 709 help 710 Socionext Synquacer SoCs implement a separate h/w block to generate 711 MSI doorbell writes with non-zero values for the device ID. 712 713 If unsure, say Y. 714 715config HISILICON_ERRATUM_161600802 716 bool "Hip07 161600802: Erroneous redistributor VLPI base" 717 default y 718 help 719 The HiSilicon Hip07 SoC uses the wrong redistributor base 720 when issued ITS commands such as VMOVP and VMAPP, and requires 721 a 128kB offset to be applied to the target address in this commands. 722 723 If unsure, say Y. 724 725config QCOM_FALKOR_ERRATUM_E1041 726 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 727 default y 728 help 729 Falkor CPU may speculatively fetch instructions from an improper 730 memory location when MMU translation is changed from SCTLR_ELn[M]=1 731 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 732 733 If unsure, say Y. 734 735config FUJITSU_ERRATUM_010001 736 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 737 default y 738 help 739 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 740 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 741 accesses may cause undefined fault (Data abort, DFSC=0b111111). 742 This fault occurs under a specific hardware condition when a 743 load/store instruction performs an address translation using: 744 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 745 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 746 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 747 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 748 749 The workaround is to ensure these bits are clear in TCR_ELx. 750 The workaround only affects the Fujitsu-A64FX. 751 752 If unsure, say Y. 753 754endmenu 755 756 757choice 758 prompt "Page size" 759 default ARM64_4K_PAGES 760 help 761 Page size (translation granule) configuration. 762 763config ARM64_4K_PAGES 764 bool "4KB" 765 help 766 This feature enables 4KB pages support. 767 768config ARM64_16K_PAGES 769 bool "16KB" 770 help 771 The system will use 16KB pages support. AArch32 emulation 772 requires applications compiled with 16K (or a multiple of 16K) 773 aligned segments. 774 775config ARM64_64K_PAGES 776 bool "64KB" 777 help 778 This feature enables 64KB pages support (4KB by default) 779 allowing only two levels of page tables and faster TLB 780 look-up. AArch32 emulation requires applications compiled 781 with 64K aligned segments. 782 783endchoice 784 785choice 786 prompt "Virtual address space size" 787 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 788 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 789 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 790 help 791 Allows choosing one of multiple possible virtual address 792 space sizes. The level of translation table is determined by 793 a combination of page size and virtual address space size. 794 795config ARM64_VA_BITS_36 796 bool "36-bit" if EXPERT 797 depends on ARM64_16K_PAGES 798 799config ARM64_VA_BITS_39 800 bool "39-bit" 801 depends on ARM64_4K_PAGES 802 803config ARM64_VA_BITS_42 804 bool "42-bit" 805 depends on ARM64_64K_PAGES 806 807config ARM64_VA_BITS_47 808 bool "47-bit" 809 depends on ARM64_16K_PAGES 810 811config ARM64_VA_BITS_48 812 bool "48-bit" 813 814config ARM64_VA_BITS_52 815 bool "52-bit" 816 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 817 help 818 Enable 52-bit virtual addressing for userspace when explicitly 819 requested via a hint to mmap(). The kernel will also use 52-bit 820 virtual addresses for its own mappings (provided HW support for 821 this feature is available, otherwise it reverts to 48-bit). 822 823 NOTE: Enabling 52-bit virtual addressing in conjunction with 824 ARMv8.3 Pointer Authentication will result in the PAC being 825 reduced from 7 bits to 3 bits, which may have a significant 826 impact on its susceptibility to brute-force attacks. 827 828 If unsure, select 48-bit virtual addressing instead. 829 830endchoice 831 832config ARM64_FORCE_52BIT 833 bool "Force 52-bit virtual addresses for userspace" 834 depends on ARM64_VA_BITS_52 && EXPERT 835 help 836 For systems with 52-bit userspace VAs enabled, the kernel will attempt 837 to maintain compatibility with older software by providing 48-bit VAs 838 unless a hint is supplied to mmap. 839 840 This configuration option disables the 48-bit compatibility logic, and 841 forces all userspace addresses to be 52-bit on HW that supports it. One 842 should only enable this configuration option for stress testing userspace 843 memory management code. If unsure say N here. 844 845config ARM64_VA_BITS 846 int 847 default 36 if ARM64_VA_BITS_36 848 default 39 if ARM64_VA_BITS_39 849 default 42 if ARM64_VA_BITS_42 850 default 47 if ARM64_VA_BITS_47 851 default 48 if ARM64_VA_BITS_48 852 default 52 if ARM64_VA_BITS_52 853 854choice 855 prompt "Physical address space size" 856 default ARM64_PA_BITS_48 857 help 858 Choose the maximum physical address range that the kernel will 859 support. 860 861config ARM64_PA_BITS_48 862 bool "48-bit" 863 864config ARM64_PA_BITS_52 865 bool "52-bit (ARMv8.2)" 866 depends on ARM64_64K_PAGES 867 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 868 help 869 Enable support for a 52-bit physical address space, introduced as 870 part of the ARMv8.2-LPA extension. 871 872 With this enabled, the kernel will also continue to work on CPUs that 873 do not support ARMv8.2-LPA, but with some added memory overhead (and 874 minor performance overhead). 875 876endchoice 877 878config ARM64_PA_BITS 879 int 880 default 48 if ARM64_PA_BITS_48 881 default 52 if ARM64_PA_BITS_52 882 883config CPU_BIG_ENDIAN 884 bool "Build big-endian kernel" 885 help 886 Say Y if you plan on running a kernel in big-endian mode. 887 888config SCHED_MC 889 bool "Multi-core scheduler support" 890 help 891 Multi-core scheduler support improves the CPU scheduler's decision 892 making when dealing with multi-core CPU chips at a cost of slightly 893 increased overhead in some places. If unsure say N here. 894 895config SCHED_SMT 896 bool "SMT scheduler support" 897 help 898 Improves the CPU scheduler's decision making when dealing with 899 MultiThreading at a cost of slightly increased overhead in some 900 places. If unsure say N here. 901 902config NR_CPUS 903 int "Maximum number of CPUs (2-4096)" 904 range 2 4096 905 default "256" 906 907config HOTPLUG_CPU 908 bool "Support for hot-pluggable CPUs" 909 select GENERIC_IRQ_MIGRATION 910 help 911 Say Y here to experiment with turning CPUs off and on. CPUs 912 can be controlled through /sys/devices/system/cpu. 913 914# Common NUMA Features 915config NUMA 916 bool "Numa Memory Allocation and Scheduler Support" 917 select ACPI_NUMA if ACPI 918 select OF_NUMA 919 help 920 Enable NUMA (Non Uniform Memory Access) support. 921 922 The kernel will try to allocate memory used by a CPU on the 923 local memory of the CPU and add some more 924 NUMA awareness to the kernel. 925 926config NODES_SHIFT 927 int "Maximum NUMA Nodes (as a power of 2)" 928 range 1 10 929 default "2" 930 depends on NEED_MULTIPLE_NODES 931 help 932 Specify the maximum number of NUMA Nodes available on the target 933 system. Increases memory reserved to accommodate various tables. 934 935config USE_PERCPU_NUMA_NODE_ID 936 def_bool y 937 depends on NUMA 938 939config HAVE_SETUP_PER_CPU_AREA 940 def_bool y 941 depends on NUMA 942 943config NEED_PER_CPU_EMBED_FIRST_CHUNK 944 def_bool y 945 depends on NUMA 946 947config HOLES_IN_ZONE 948 def_bool y 949 950source "kernel/Kconfig.hz" 951 952config ARCH_SUPPORTS_DEBUG_PAGEALLOC 953 def_bool y 954 955config ARCH_SPARSEMEM_ENABLE 956 def_bool y 957 select SPARSEMEM_VMEMMAP_ENABLE 958 959config ARCH_SPARSEMEM_DEFAULT 960 def_bool ARCH_SPARSEMEM_ENABLE 961 962config ARCH_SELECT_MEMORY_MODEL 963 def_bool ARCH_SPARSEMEM_ENABLE 964 965config ARCH_FLATMEM_ENABLE 966 def_bool !NUMA 967 968config HAVE_ARCH_PFN_VALID 969 def_bool y 970 971config HW_PERF_EVENTS 972 def_bool y 973 depends on ARM_PMU 974 975config SYS_SUPPORTS_HUGETLBFS 976 def_bool y 977 978config ARCH_WANT_HUGE_PMD_SHARE 979 980config ARCH_HAS_CACHE_LINE_SIZE 981 def_bool y 982 983config ARCH_ENABLE_SPLIT_PMD_PTLOCK 984 def_bool y if PGTABLE_LEVELS > 2 985 986# Supported by clang >= 7.0 987config CC_HAVE_SHADOW_CALL_STACK 988 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 989 990config SECCOMP 991 bool "Enable seccomp to safely compute untrusted bytecode" 992 ---help--- 993 This kernel feature is useful for number crunching applications 994 that may need to compute untrusted bytecode during their 995 execution. By using pipes or other transports made available to 996 the process as file descriptors supporting the read/write 997 syscalls, it's possible to isolate those applications in 998 their own address space using seccomp. Once seccomp is 999 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1000 and the task is only allowed to execute a few safe syscalls 1001 defined by each seccomp mode. 1002 1003config PARAVIRT 1004 bool "Enable paravirtualization code" 1005 help 1006 This changes the kernel so it can modify itself when it is run 1007 under a hypervisor, potentially improving performance significantly 1008 over full virtualization. 1009 1010config PARAVIRT_TIME_ACCOUNTING 1011 bool "Paravirtual steal time accounting" 1012 select PARAVIRT 1013 help 1014 Select this option to enable fine granularity task steal time 1015 accounting. Time spent executing other tasks in parallel with 1016 the current vCPU is discounted from the vCPU power. To account for 1017 that, there can be a small performance impact. 1018 1019 If in doubt, say N here. 1020 1021config KEXEC 1022 depends on PM_SLEEP_SMP 1023 select KEXEC_CORE 1024 bool "kexec system call" 1025 ---help--- 1026 kexec is a system call that implements the ability to shutdown your 1027 current kernel, and to start another kernel. It is like a reboot 1028 but it is independent of the system firmware. And like a reboot 1029 you can start any kernel with it, not just Linux. 1030 1031config KEXEC_FILE 1032 bool "kexec file based system call" 1033 select KEXEC_CORE 1034 help 1035 This is new version of kexec system call. This system call is 1036 file based and takes file descriptors as system call argument 1037 for kernel and initramfs as opposed to list of segments as 1038 accepted by previous system call. 1039 1040config KEXEC_SIG 1041 bool "Verify kernel signature during kexec_file_load() syscall" 1042 depends on KEXEC_FILE 1043 help 1044 Select this option to verify a signature with loaded kernel 1045 image. If configured, any attempt of loading a image without 1046 valid signature will fail. 1047 1048 In addition to that option, you need to enable signature 1049 verification for the corresponding kernel image type being 1050 loaded in order for this to work. 1051 1052config KEXEC_IMAGE_VERIFY_SIG 1053 bool "Enable Image signature verification support" 1054 default y 1055 depends on KEXEC_SIG 1056 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1057 help 1058 Enable Image signature verification support. 1059 1060comment "Support for PE file signature verification disabled" 1061 depends on KEXEC_SIG 1062 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1063 1064config CRASH_DUMP 1065 bool "Build kdump crash kernel" 1066 help 1067 Generate crash dump after being started by kexec. This should 1068 be normally only set in special crash dump kernels which are 1069 loaded in the main kernel with kexec-tools into a specially 1070 reserved region and then later executed after a crash by 1071 kdump/kexec. 1072 1073 For more details see Documentation/admin-guide/kdump/kdump.rst 1074 1075config XEN_DOM0 1076 def_bool y 1077 depends on XEN 1078 1079config XEN 1080 bool "Xen guest support on ARM64" 1081 depends on ARM64 && OF 1082 select SWIOTLB_XEN 1083 select PARAVIRT 1084 help 1085 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1086 1087config FORCE_MAX_ZONEORDER 1088 int 1089 default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) 1090 default "12" if (ARM64_16K_PAGES && TRANSPARENT_HUGEPAGE) 1091 default "11" 1092 help 1093 The kernel memory allocator divides physically contiguous memory 1094 blocks into "zones", where each zone is a power of two number of 1095 pages. This option selects the largest power of two that the kernel 1096 keeps in the memory allocator. If you need to allocate very large 1097 blocks of physically contiguous memory, then you may need to 1098 increase this value. 1099 1100 This config option is actually maximum order plus one. For example, 1101 a value of 11 means that the largest free memory block is 2^10 pages. 1102 1103 We make sure that we can allocate upto a HugePage size for each configuration. 1104 Hence we have : 1105 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1106 1107 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1108 4M allocations matching the default size used by generic code. 1109 1110config UNMAP_KERNEL_AT_EL0 1111 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1112 default y 1113 help 1114 Speculation attacks against some high-performance processors can 1115 be used to bypass MMU permission checks and leak kernel data to 1116 userspace. This can be defended against by unmapping the kernel 1117 when running in userspace, mapping it back in on exception entry 1118 via a trampoline page in the vector table. 1119 1120 If unsure, say Y. 1121 1122config HARDEN_BRANCH_PREDICTOR 1123 bool "Harden the branch predictor against aliasing attacks" if EXPERT 1124 default y 1125 help 1126 Speculation attacks against some high-performance processors rely on 1127 being able to manipulate the branch predictor for a victim context by 1128 executing aliasing branches in the attacker context. Such attacks 1129 can be partially mitigated against by clearing internal branch 1130 predictor state and limiting the prediction logic in some situations. 1131 1132 This config option will take CPU-specific actions to harden the 1133 branch predictor against aliasing attacks and may rely on specific 1134 instruction sequences or control bits being set by the system 1135 firmware. 1136 1137 If unsure, say Y. 1138 1139config HARDEN_EL2_VECTORS 1140 bool "Harden EL2 vector mapping against system register leak" if EXPERT 1141 default y 1142 help 1143 Speculation attacks against some high-performance processors can 1144 be used to leak privileged information such as the vector base 1145 register, resulting in a potential defeat of the EL2 layout 1146 randomization. 1147 1148 This config option will map the vectors to a fixed location, 1149 independent of the EL2 code mapping, so that revealing VBAR_EL2 1150 to an attacker does not give away any extra information. This 1151 only gets enabled on affected CPUs. 1152 1153 If unsure, say Y. 1154 1155config ARM64_SSBD 1156 bool "Speculative Store Bypass Disable" if EXPERT 1157 default y 1158 help 1159 This enables mitigation of the bypassing of previous stores 1160 by speculative loads. 1161 1162 If unsure, say Y. 1163 1164config MITIGATE_SPECTRE_BRANCH_HISTORY 1165 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1166 default y 1167 help 1168 Speculation attacks against some high-performance processors can 1169 make use of branch history to influence future speculation. 1170 When taking an exception from user-space, a sequence of branches 1171 or a firmware call overwrites the branch history. 1172 1173config RODATA_FULL_DEFAULT_ENABLED 1174 bool "Apply r/o permissions of VM areas also to their linear aliases" 1175 default y 1176 help 1177 Apply read-only attributes of VM areas to the linear alias of 1178 the backing pages as well. This prevents code or read-only data 1179 from being modified (inadvertently or intentionally) via another 1180 mapping of the same memory page. This additional enhancement can 1181 be turned off at runtime by passing rodata=[off|on] (and turned on 1182 with rodata=full if this option is set to 'n') 1183 1184 This requires the linear region to be mapped down to pages, 1185 which may adversely affect performance in some cases. 1186 1187config ARM64_SW_TTBR0_PAN 1188 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1189 help 1190 Enabling this option prevents the kernel from accessing 1191 user-space memory directly by pointing TTBR0_EL1 to a reserved 1192 zeroed area and reserved ASID. The user access routines 1193 restore the valid TTBR0_EL1 temporarily. 1194 1195config ARM64_TAGGED_ADDR_ABI 1196 bool "Enable the tagged user addresses syscall ABI" 1197 default y 1198 help 1199 When this option is enabled, user applications can opt in to a 1200 relaxed ABI via prctl() allowing tagged addresses to be passed 1201 to system calls as pointer arguments. For details, see 1202 Documentation/arm64/tagged-address-abi.rst. 1203 1204menuconfig COMPAT 1205 bool "Kernel support for 32-bit EL0" 1206 depends on ARM64_4K_PAGES || EXPERT 1207 select COMPAT_BINFMT_ELF if BINFMT_ELF 1208 select HAVE_UID16 1209 select OLD_SIGSUSPEND3 1210 select COMPAT_OLD_SIGACTION 1211 help 1212 This option enables support for a 32-bit EL0 running under a 64-bit 1213 kernel at EL1. AArch32-specific components such as system calls, 1214 the user helper functions, VFP support and the ptrace interface are 1215 handled appropriately by the kernel. 1216 1217 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1218 that you will only be able to execute AArch32 binaries that were compiled 1219 with page size aligned segments. 1220 1221 If you want to execute 32-bit userspace applications, say Y. 1222 1223if COMPAT 1224 1225config KUSER_HELPERS 1226 bool "Enable kuser helpers page for 32-bit applications" 1227 default y 1228 help 1229 Warning: disabling this option may break 32-bit user programs. 1230 1231 Provide kuser helpers to compat tasks. The kernel provides 1232 helper code to userspace in read only form at a fixed location 1233 to allow userspace to be independent of the CPU type fitted to 1234 the system. This permits binaries to be run on ARMv4 through 1235 to ARMv8 without modification. 1236 1237 See Documentation/arm/kernel_user_helpers.rst for details. 1238 1239 However, the fixed address nature of these helpers can be used 1240 by ROP (return orientated programming) authors when creating 1241 exploits. 1242 1243 If all of the binaries and libraries which run on your platform 1244 are built specifically for your platform, and make no use of 1245 these helpers, then you can turn this option off to hinder 1246 such exploits. However, in that case, if a binary or library 1247 relying on those helpers is run, it will not function correctly. 1248 1249 Say N here only if you are absolutely certain that you do not 1250 need these helpers; otherwise, the safe option is to say Y. 1251 1252config COMPAT_VDSO 1253 bool "Enable vDSO for 32-bit applications" 1254 depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != "" 1255 select GENERIC_COMPAT_VDSO 1256 default y 1257 help 1258 Place in the process address space of 32-bit applications an 1259 ELF shared object providing fast implementations of gettimeofday 1260 and clock_gettime. 1261 1262 You must have a 32-bit build of glibc 2.22 or later for programs 1263 to seamlessly take advantage of this. 1264 1265menuconfig ARMV8_DEPRECATED 1266 bool "Emulate deprecated/obsolete ARMv8 instructions" 1267 depends on SYSCTL 1268 help 1269 Legacy software support may require certain instructions 1270 that have been deprecated or obsoleted in the architecture. 1271 1272 Enable this config to enable selective emulation of these 1273 features. 1274 1275 If unsure, say Y 1276 1277if ARMV8_DEPRECATED 1278 1279config SWP_EMULATION 1280 bool "Emulate SWP/SWPB instructions" 1281 help 1282 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1283 they are always undefined. Say Y here to enable software 1284 emulation of these instructions for userspace using LDXR/STXR. 1285 1286 In some older versions of glibc [<=2.8] SWP is used during futex 1287 trylock() operations with the assumption that the code will not 1288 be preempted. This invalid assumption may be more likely to fail 1289 with SWP emulation enabled, leading to deadlock of the user 1290 application. 1291 1292 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1293 on an external transaction monitoring block called a global 1294 monitor to maintain update atomicity. If your system does not 1295 implement a global monitor, this option can cause programs that 1296 perform SWP operations to uncached memory to deadlock. 1297 1298 If unsure, say Y 1299 1300config CP15_BARRIER_EMULATION 1301 bool "Emulate CP15 Barrier instructions" 1302 help 1303 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1304 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1305 strongly recommended to use the ISB, DSB, and DMB 1306 instructions instead. 1307 1308 Say Y here to enable software emulation of these 1309 instructions for AArch32 userspace code. When this option is 1310 enabled, CP15 barrier usage is traced which can help 1311 identify software that needs updating. 1312 1313 If unsure, say Y 1314 1315config SETEND_EMULATION 1316 bool "Emulate SETEND instruction" 1317 help 1318 The SETEND instruction alters the data-endianness of the 1319 AArch32 EL0, and is deprecated in ARMv8. 1320 1321 Say Y here to enable software emulation of the instruction 1322 for AArch32 userspace code. 1323 1324 Note: All the cpus on the system must have mixed endian support at EL0 1325 for this feature to be enabled. If a new CPU - which doesn't support mixed 1326 endian - is hotplugged in after this feature has been enabled, there could 1327 be unexpected results in the applications. 1328 1329 If unsure, say Y 1330endif 1331 1332endif 1333 1334menu "ARMv8.1 architectural features" 1335 1336config ARM64_HW_AFDBM 1337 bool "Support for hardware updates of the Access and Dirty page flags" 1338 default y 1339 help 1340 The ARMv8.1 architecture extensions introduce support for 1341 hardware updates of the access and dirty information in page 1342 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1343 capable processors, accesses to pages with PTE_AF cleared will 1344 set this bit instead of raising an access flag fault. 1345 Similarly, writes to read-only pages with the DBM bit set will 1346 clear the read-only bit (AP[2]) instead of raising a 1347 permission fault. 1348 1349 Kernels built with this configuration option enabled continue 1350 to work on pre-ARMv8.1 hardware and the performance impact is 1351 minimal. If unsure, say Y. 1352 1353config ARM64_PAN 1354 bool "Enable support for Privileged Access Never (PAN)" 1355 default y 1356 help 1357 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1358 prevents the kernel or hypervisor from accessing user-space (EL0) 1359 memory directly. 1360 1361 Choosing this option will cause any unprotected (not using 1362 copy_to_user et al) memory access to fail with a permission fault. 1363 1364 The feature is detected at runtime, and will remain as a 'nop' 1365 instruction if the cpu does not implement the feature. 1366 1367config ARM64_LSE_ATOMICS 1368 bool "Atomic instructions" 1369 depends on JUMP_LABEL 1370 default y 1371 help 1372 As part of the Large System Extensions, ARMv8.1 introduces new 1373 atomic instructions that are designed specifically to scale in 1374 very large systems. 1375 1376 Say Y here to make use of these instructions for the in-kernel 1377 atomic routines. This incurs a small overhead on CPUs that do 1378 not support these instructions and requires the kernel to be 1379 built with binutils >= 2.25 in order for the new instructions 1380 to be used. 1381 1382config ARM64_VHE 1383 bool "Enable support for Virtualization Host Extensions (VHE)" 1384 default y 1385 help 1386 Virtualization Host Extensions (VHE) allow the kernel to run 1387 directly at EL2 (instead of EL1) on processors that support 1388 it. This leads to better performance for KVM, as they reduce 1389 the cost of the world switch. 1390 1391 Selecting this option allows the VHE feature to be detected 1392 at runtime, and does not affect processors that do not 1393 implement this feature. 1394 1395endmenu 1396 1397menu "ARMv8.2 architectural features" 1398 1399config ARM64_UAO 1400 bool "Enable support for User Access Override (UAO)" 1401 default y 1402 help 1403 User Access Override (UAO; part of the ARMv8.2 Extensions) 1404 causes the 'unprivileged' variant of the load/store instructions to 1405 be overridden to be privileged. 1406 1407 This option changes get_user() and friends to use the 'unprivileged' 1408 variant of the load/store instructions. This ensures that user-space 1409 really did have access to the supplied memory. When addr_limit is 1410 set to kernel memory the UAO bit will be set, allowing privileged 1411 access to kernel memory. 1412 1413 Choosing this option will cause copy_to_user() et al to use user-space 1414 memory permissions. 1415 1416 The feature is detected at runtime, the kernel will use the 1417 regular load/store instructions if the cpu does not implement the 1418 feature. 1419 1420config ARM64_PMEM 1421 bool "Enable support for persistent memory" 1422 select ARCH_HAS_PMEM_API 1423 select ARCH_HAS_UACCESS_FLUSHCACHE 1424 help 1425 Say Y to enable support for the persistent memory API based on the 1426 ARMv8.2 DCPoP feature. 1427 1428 The feature is detected at runtime, and the kernel will use DC CVAC 1429 operations if DC CVAP is not supported (following the behaviour of 1430 DC CVAP itself if the system does not define a point of persistence). 1431 1432config ARM64_RAS_EXTN 1433 bool "Enable support for RAS CPU Extensions" 1434 default y 1435 help 1436 CPUs that support the Reliability, Availability and Serviceability 1437 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1438 errors, classify them and report them to software. 1439 1440 On CPUs with these extensions system software can use additional 1441 barriers to determine if faults are pending and read the 1442 classification from a new set of registers. 1443 1444 Selecting this feature will allow the kernel to use these barriers 1445 and access the new registers if the system supports the extension. 1446 Platform RAS features may additionally depend on firmware support. 1447 1448config ARM64_CNP 1449 bool "Enable support for Common Not Private (CNP) translations" 1450 default y 1451 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1452 help 1453 Common Not Private (CNP) allows translation table entries to 1454 be shared between different PEs in the same inner shareable 1455 domain, so the hardware can use this fact to optimise the 1456 caching of such entries in the TLB. 1457 1458 Selecting this option allows the CNP feature to be detected 1459 at runtime, and does not affect PEs that do not implement 1460 this feature. 1461 1462endmenu 1463 1464menu "ARMv8.3 architectural features" 1465 1466config ARM64_PTR_AUTH 1467 bool "Enable support for pointer authentication" 1468 default y 1469 depends on !KVM || ARM64_VHE 1470 help 1471 Pointer authentication (part of the ARMv8.3 Extensions) provides 1472 instructions for signing and authenticating pointers against secret 1473 keys, which can be used to mitigate Return Oriented Programming (ROP) 1474 and other attacks. 1475 1476 This option enables these instructions at EL0 (i.e. for userspace). 1477 1478 Choosing this option will cause the kernel to initialise secret keys 1479 for each process at exec() time, with these keys being 1480 context-switched along with the process. 1481 1482 The feature is detected at runtime. If the feature is not present in 1483 hardware it will not be advertised to userspace/KVM guest nor will it 1484 be enabled. However, KVM guest also require VHE mode and hence 1485 CONFIG_ARM64_VHE=y option to use this feature. 1486 1487endmenu 1488 1489menu "ARMv8.4 architectural features" 1490 1491config ARM64_AMU_EXTN 1492 bool "Enable support for the Activity Monitors Unit CPU extension" 1493 default y 1494 help 1495 The activity monitors extension is an optional extension introduced 1496 by the ARMv8.4 CPU architecture. This enables support for version 1 1497 of the activity monitors architecture, AMUv1. 1498 1499 To enable the use of this extension on CPUs that implement it, say Y. 1500 1501 Note that for architectural reasons, firmware _must_ implement AMU 1502 support when running on CPUs that present the activity monitors 1503 extension. The required support is present in: 1504 * Version 1.5 and later of the ARM Trusted Firmware 1505 1506 For kernels that have this configuration enabled but boot with broken 1507 firmware, you may need to say N here until the firmware is fixed. 1508 Otherwise you may experience firmware panics or lockups when 1509 accessing the counter registers. Even if you are not observing these 1510 symptoms, the values returned by the register reads might not 1511 correctly reflect reality. Most commonly, the value read will be 0, 1512 indicating that the counter is not enabled. 1513 1514endmenu 1515 1516config ARM64_SVE 1517 bool "ARM Scalable Vector Extension support" 1518 default y 1519 depends on !KVM || ARM64_VHE 1520 help 1521 The Scalable Vector Extension (SVE) is an extension to the AArch64 1522 execution state which complements and extends the SIMD functionality 1523 of the base architecture to support much larger vectors and to enable 1524 additional vectorisation opportunities. 1525 1526 To enable use of this extension on CPUs that implement it, say Y. 1527 1528 On CPUs that support the SVE2 extensions, this option will enable 1529 those too. 1530 1531 Note that for architectural reasons, firmware _must_ implement SVE 1532 support when running on SVE capable hardware. The required support 1533 is present in: 1534 1535 * version 1.5 and later of the ARM Trusted Firmware 1536 * the AArch64 boot wrapper since commit 5e1261e08abf 1537 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1538 1539 For other firmware implementations, consult the firmware documentation 1540 or vendor. 1541 1542 If you need the kernel to boot on SVE-capable hardware with broken 1543 firmware, you may need to say N here until you get your firmware 1544 fixed. Otherwise, you may experience firmware panics or lockups when 1545 booting the kernel. If unsure and you are not observing these 1546 symptoms, you should assume that it is safe to say Y. 1547 1548 CPUs that support SVE are architecturally required to support the 1549 Virtualization Host Extensions (VHE), so the kernel makes no 1550 provision for supporting SVE alongside KVM without VHE enabled. 1551 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1552 KVM in the same kernel image. 1553 1554config ARM64_MODULE_PLTS 1555 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1556 depends on MODULES 1557 select HAVE_MOD_ARCH_SPECIFIC 1558 help 1559 Allocate PLTs when loading modules so that jumps and calls whose 1560 targets are too far away for their relative offsets to be encoded 1561 in the instructions themselves can be bounced via veneers in the 1562 module's PLT. This allows modules to be allocated in the generic 1563 vmalloc area after the dedicated module memory area has been 1564 exhausted. 1565 1566 When running with address space randomization (KASLR), the module 1567 region itself may be too far away for ordinary relative jumps and 1568 calls, and so in that case, module PLTs are required and cannot be 1569 disabled. 1570 1571 Specific errata workaround(s) might also force module PLTs to be 1572 enabled (ARM64_ERRATUM_843419). 1573 1574config ARM64_PSEUDO_NMI 1575 bool "Support for NMI-like interrupts" 1576 select CONFIG_ARM_GIC_V3 1577 help 1578 Adds support for mimicking Non-Maskable Interrupts through the use of 1579 GIC interrupt priority. This support requires version 3 or later of 1580 ARM GIC. 1581 1582 This high priority configuration for interrupts needs to be 1583 explicitly enabled by setting the kernel parameter 1584 "irqchip.gicv3_pseudo_nmi" to 1. 1585 1586 If unsure, say N 1587 1588if ARM64_PSEUDO_NMI 1589config ARM64_DEBUG_PRIORITY_MASKING 1590 bool "Debug interrupt priority masking" 1591 help 1592 This adds runtime checks to functions enabling/disabling 1593 interrupts when using priority masking. The additional checks verify 1594 the validity of ICC_PMR_EL1 when calling concerned functions. 1595 1596 If unsure, say N 1597endif 1598 1599config RELOCATABLE 1600 bool 1601 select ARCH_HAS_RELR 1602 help 1603 This builds the kernel as a Position Independent Executable (PIE), 1604 which retains all relocation metadata required to relocate the 1605 kernel binary at runtime to a different virtual address than the 1606 address it was linked at. 1607 Since AArch64 uses the RELA relocation format, this requires a 1608 relocation pass at runtime even if the kernel is loaded at the 1609 same address it was linked at. 1610 1611config RANDOMIZE_BASE 1612 bool "Randomize the address of the kernel image" 1613 select ARM64_MODULE_PLTS if MODULES 1614 select RELOCATABLE 1615 help 1616 Randomizes the virtual address at which the kernel image is 1617 loaded, as a security feature that deters exploit attempts 1618 relying on knowledge of the location of kernel internals. 1619 1620 It is the bootloader's job to provide entropy, by passing a 1621 random u64 value in /chosen/kaslr-seed at kernel entry. 1622 1623 When booting via the UEFI stub, it will invoke the firmware's 1624 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1625 to the kernel proper. In addition, it will randomise the physical 1626 location of the kernel Image as well. 1627 1628 If unsure, say N. 1629 1630config RANDOMIZE_MODULE_REGION_FULL 1631 bool "Randomize the module region over a 4 GB range" 1632 depends on RANDOMIZE_BASE 1633 default y 1634 help 1635 Randomizes the location of the module region inside a 4 GB window 1636 covering the core kernel. This way, it is less likely for modules 1637 to leak information about the location of core kernel data structures 1638 but it does imply that function calls between modules and the core 1639 kernel will need to be resolved via veneers in the module PLT. 1640 1641 When this option is not set, the module region will be randomized over 1642 a limited range that contains the [_stext, _etext] interval of the 1643 core kernel, so branch relocations are always in range. 1644 1645config CC_HAVE_STACKPROTECTOR_SYSREG 1646 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1647 1648config STACKPROTECTOR_PER_TASK 1649 def_bool y 1650 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1651 1652endmenu 1653 1654menu "Boot options" 1655 1656config ARM64_ACPI_PARKING_PROTOCOL 1657 bool "Enable support for the ARM64 ACPI parking protocol" 1658 depends on ACPI 1659 help 1660 Enable support for the ARM64 ACPI parking protocol. If disabled 1661 the kernel will not allow booting through the ARM64 ACPI parking 1662 protocol even if the corresponding data is present in the ACPI 1663 MADT table. 1664 1665config CMDLINE 1666 string "Default kernel command string" 1667 default "" 1668 help 1669 Provide a set of default command-line options at build time by 1670 entering them here. As a minimum, you should specify the the 1671 root device (e.g. root=/dev/nfs). 1672 1673choice 1674 prompt "Kernel command line type" if CMDLINE != "" 1675 default CMDLINE_FROM_BOOTLOADER 1676 1677config CMDLINE_FROM_BOOTLOADER 1678 bool "Use bootloader kernel arguments if available" 1679 help 1680 Uses the command-line options passed by the boot loader. If 1681 the boot loader doesn't provide any, the default kernel command 1682 string provided in CMDLINE will be used. 1683 1684config CMDLINE_EXTEND 1685 bool "Extend bootloader kernel arguments" 1686 help 1687 The command-line arguments provided by the boot loader will be 1688 appended to the default kernel command string. 1689 1690config CMDLINE_FORCE 1691 bool "Always use the default kernel command string" 1692 help 1693 Always use the default kernel command string, even if the boot 1694 loader passes other arguments to the kernel. 1695 This is useful if you cannot or don't want to change the 1696 command-line options your boot loader passes to the kernel. 1697endchoice 1698 1699config EFI_STUB 1700 bool 1701 1702config EFI 1703 bool "UEFI runtime support" 1704 depends on OF && !CPU_BIG_ENDIAN 1705 depends on KERNEL_MODE_NEON 1706 select ARCH_SUPPORTS_ACPI 1707 select LIBFDT 1708 select UCS2_STRING 1709 select EFI_PARAMS_FROM_FDT 1710 select EFI_RUNTIME_WRAPPERS 1711 select EFI_STUB 1712 select EFI_ARMSTUB 1713 default y 1714 help 1715 This option provides support for runtime services provided 1716 by UEFI firmware (such as non-volatile variables, realtime 1717 clock, and platform reset). A UEFI stub is also provided to 1718 allow the kernel to be booted as an EFI application. This 1719 is only useful on systems that have UEFI firmware. 1720 1721config DMI 1722 bool "Enable support for SMBIOS (DMI) tables" 1723 depends on EFI 1724 default y 1725 help 1726 This enables SMBIOS/DMI feature for systems. 1727 1728 This option is only useful on systems that have UEFI firmware. 1729 However, even with this option, the resultant kernel should 1730 continue to boot on existing non-UEFI platforms. 1731 1732endmenu 1733 1734config SYSVIPC_COMPAT 1735 def_bool y 1736 depends on COMPAT && SYSVIPC 1737 1738config ARCH_ENABLE_HUGEPAGE_MIGRATION 1739 def_bool y 1740 depends on HUGETLB_PAGE && MIGRATION 1741 1742menu "Power management options" 1743 1744source "kernel/power/Kconfig" 1745 1746config ARCH_HIBERNATION_POSSIBLE 1747 def_bool y 1748 depends on CPU_PM 1749 1750config ARCH_HIBERNATION_HEADER 1751 def_bool y 1752 depends on HIBERNATION 1753 1754config ARCH_SUSPEND_POSSIBLE 1755 def_bool y 1756 1757endmenu 1758 1759menu "CPU Power Management" 1760 1761source "drivers/cpuidle/Kconfig" 1762 1763source "drivers/cpufreq/Kconfig" 1764 1765endmenu 1766 1767source "drivers/firmware/Kconfig" 1768 1769source "drivers/acpi/Kconfig" 1770 1771source "arch/arm64/kvm/Kconfig" 1772 1773if CRYPTO 1774source "arch/arm64/crypto/Kconfig" 1775endif 1776