1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CURRENT_STACK_POINTER 25 select ARCH_HAS_DEBUG_VIRTUAL 26 select ARCH_HAS_DEBUG_VM_PGTABLE 27 select ARCH_HAS_DMA_OPS if XEN 28 select ARCH_HAS_DMA_PREP_COHERENT 29 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 30 select ARCH_HAS_FAST_MULTIPLIER 31 select ARCH_HAS_FORTIFY_SOURCE 32 select ARCH_HAS_GCOV_PROFILE_ALL 33 select ARCH_HAS_GIGANTIC_PAGE 34 select ARCH_HAS_KCOV 35 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 36 select ARCH_HAS_KEEPINITRD 37 select ARCH_HAS_MEMBARRIER_SYNC_CORE 38 select ARCH_HAS_MEM_ENCRYPT 39 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 40 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 42 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 43 select ARCH_HAS_PREEMPT_LAZY 44 select ARCH_HAS_PTDUMP 45 select ARCH_HAS_PTE_SPECIAL 46 select ARCH_HAS_HW_PTE_YOUNG 47 select ARCH_HAS_SETUP_DMA_OPS 48 select ARCH_HAS_SET_DIRECT_MAP 49 select ARCH_HAS_SET_MEMORY 50 select ARCH_HAS_MEM_ENCRYPT 51 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 52 select ARCH_STACKWALK 53 select ARCH_HAS_STRICT_KERNEL_RWX 54 select ARCH_HAS_STRICT_MODULE_RWX 55 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 56 select ARCH_HAS_SYNC_DMA_FOR_CPU 57 select ARCH_HAS_SYSCALL_WRAPPER 58 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 59 select ARCH_HAS_ZONE_DMA_SET if EXPERT 60 select ARCH_HAVE_ELF_PROT 61 select ARCH_HAVE_NMI_SAFE_CMPXCHG 62 select ARCH_HAVE_TRACE_MMIO_ACCESS 63 select ARCH_INLINE_READ_LOCK if !PREEMPTION 64 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 67 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 71 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 75 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 79 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 80 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 81 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 85 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 89 select ARCH_KEEP_MEMBLOCK 90 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 91 select ARCH_USE_CMPXCHG_LOCKREF 92 select ARCH_USE_GNU_PROPERTY 93 select ARCH_USE_MEMTEST 94 select ARCH_USE_QUEUED_RWLOCKS 95 select ARCH_USE_QUEUED_SPINLOCKS 96 select ARCH_USE_SYM_ANNOTATIONS 97 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 98 select ARCH_SUPPORTS_HUGETLBFS 99 select ARCH_SUPPORTS_MEMORY_FAILURE 100 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 101 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 102 select ARCH_SUPPORTS_LTO_CLANG_THIN 103 select ARCH_SUPPORTS_CFI_CLANG 104 select ARCH_SUPPORTS_ATOMIC_RMW 105 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 106 select ARCH_SUPPORTS_NUMA_BALANCING 107 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 108 select ARCH_SUPPORTS_PER_VMA_LOCK 109 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 110 select ARCH_SUPPORTS_RT 111 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 112 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 113 select ARCH_WANT_DEFAULT_BPF_JIT 114 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 115 select ARCH_WANT_FRAME_POINTERS 116 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 117 select ARCH_WANT_LD_ORPHAN_WARN 118 select ARCH_WANTS_EXECMEM_LATE 119 select ARCH_WANTS_NO_INSTR 120 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 121 select ARCH_HAS_UBSAN 122 select ARM_AMBA 123 select ARM_ARCH_TIMER 124 select ARM_GIC 125 select AUDIT_ARCH_COMPAT_GENERIC 126 select ARM_GIC_V2M if PCI 127 select ARM_GIC_V3 128 select ARM_GIC_V3_ITS if PCI 129 select ARM_GIC_V5 130 select ARM_PSCI_FW 131 select BUILDTIME_TABLE_SORT 132 select CLONE_BACKWARDS 133 select COMMON_CLK 134 select CPU_PM if (SUSPEND || CPU_IDLE) 135 select CPUMASK_OFFSTACK if NR_CPUS > 256 136 select DCACHE_WORD_ACCESS 137 select HAVE_EXTRA_IPI_TRACEPOINTS 138 select DYNAMIC_FTRACE if FUNCTION_TRACER 139 select DMA_BOUNCE_UNALIGNED_KMALLOC 140 select DMA_DIRECT_REMAP 141 select EDAC_SUPPORT 142 select FRAME_POINTER 143 select FUNCTION_ALIGNMENT_4B 144 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 145 select GENERIC_ALLOCATOR 146 select GENERIC_ARCH_TOPOLOGY 147 select GENERIC_CLOCKEVENTS_BROADCAST 148 select GENERIC_CPU_AUTOPROBE 149 select GENERIC_CPU_DEVICES 150 select GENERIC_CPU_VULNERABILITIES 151 select GENERIC_EARLY_IOREMAP 152 select GENERIC_IDLE_POLL_SETUP 153 select GENERIC_IOREMAP 154 select GENERIC_IRQ_IPI 155 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 156 select GENERIC_IRQ_PROBE 157 select GENERIC_IRQ_SHOW 158 select GENERIC_IRQ_SHOW_LEVEL 159 select GENERIC_LIB_DEVMEM_IS_ALLOWED 160 select GENERIC_PCI_IOMAP 161 select GENERIC_SCHED_CLOCK 162 select GENERIC_SMP_IDLE_THREAD 163 select GENERIC_TIME_VSYSCALL 164 select GENERIC_GETTIMEOFDAY 165 select HARDIRQS_SW_RESEND 166 select HAS_IOPORT 167 select HAVE_MOVE_PMD 168 select HAVE_MOVE_PUD 169 select HAVE_PCI 170 select HAVE_ACPI_APEI if (ACPI && EFI) 171 select HAVE_ALIGNED_STRUCT_PAGE 172 select HAVE_ARCH_AUDITSYSCALL 173 select HAVE_ARCH_BITREVERSE 174 select HAVE_ARCH_COMPILER_H 175 select HAVE_ARCH_HUGE_VMALLOC 176 select HAVE_ARCH_HUGE_VMAP 177 select HAVE_ARCH_JUMP_LABEL 178 select HAVE_ARCH_JUMP_LABEL_RELATIVE 179 select HAVE_ARCH_KASAN 180 select HAVE_ARCH_KASAN_VMALLOC 181 select HAVE_ARCH_KASAN_SW_TAGS 182 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 183 # Some instrumentation may be unsound, hence EXPERT 184 select HAVE_ARCH_KCSAN if EXPERT 185 select HAVE_ARCH_KFENCE 186 select HAVE_ARCH_KGDB 187 select HAVE_ARCH_KSTACK_ERASE 188 select HAVE_ARCH_MMAP_RND_BITS 189 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 190 select HAVE_ARCH_PREL32_RELOCATIONS 191 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 192 select HAVE_ARCH_SECCOMP_FILTER 193 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 194 select HAVE_ARCH_TRACEHOOK 195 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 196 select HAVE_ARCH_VMAP_STACK 197 select HAVE_ARM_SMCCC 198 select HAVE_ASM_MODVERSIONS 199 select HAVE_EBPF_JIT 200 select HAVE_C_RECORDMCOUNT 201 select HAVE_CMPXCHG_DOUBLE 202 select HAVE_CMPXCHG_LOCAL 203 select HAVE_CONTEXT_TRACKING_USER 204 select HAVE_DEBUG_KMEMLEAK 205 select HAVE_DMA_CONTIGUOUS 206 select HAVE_DYNAMIC_FTRACE 207 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 208 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 209 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 210 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 211 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 212 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 213 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 214 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 215 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 216 if DYNAMIC_FTRACE_WITH_ARGS 217 select HAVE_SAMPLE_FTRACE_DIRECT 218 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 219 select HAVE_BUILDTIME_MCOUNT_SORT 220 select HAVE_EFFICIENT_UNALIGNED_ACCESS 221 select HAVE_GUP_FAST 222 select HAVE_FTRACE_GRAPH_FUNC 223 select HAVE_FUNCTION_TRACER 224 select HAVE_FUNCTION_ERROR_INJECTION 225 select HAVE_FUNCTION_GRAPH_FREGS 226 select HAVE_FUNCTION_GRAPH_TRACER 227 select HAVE_GCC_PLUGINS 228 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 229 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 230 select HAVE_HW_BREAKPOINT if PERF_EVENTS 231 select HAVE_IOREMAP_PROT 232 select HAVE_IRQ_TIME_ACCOUNTING 233 select HAVE_LIVEPATCH 234 select HAVE_MOD_ARCH_SPECIFIC 235 select HAVE_NMI 236 select HAVE_PERF_EVENTS 237 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 238 select HAVE_PERF_REGS 239 select HAVE_PERF_USER_STACK_DUMP 240 select HAVE_PREEMPT_DYNAMIC_KEY 241 select HAVE_REGS_AND_STACK_ACCESS_API 242 select HAVE_RELIABLE_STACKTRACE 243 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 244 select HAVE_FUNCTION_ARG_ACCESS_API 245 select MMU_GATHER_RCU_TABLE_FREE 246 select HAVE_RSEQ 247 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 248 select HAVE_STACKPROTECTOR 249 select HAVE_SYSCALL_TRACEPOINTS 250 select HAVE_KPROBES 251 select HAVE_KRETPROBES 252 select HAVE_GENERIC_VDSO 253 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 254 select HOTPLUG_SMT if HOTPLUG_CPU 255 select IRQ_DOMAIN 256 select IRQ_FORCED_THREADING 257 select JUMP_LABEL 258 select KASAN_VMALLOC if KASAN 259 select LOCK_MM_AND_FIND_VMA 260 select MODULES_USE_ELF_RELA 261 select NEED_DMA_MAP_STATE 262 select NEED_SG_DMA_LENGTH 263 select OF 264 select OF_EARLY_FLATTREE 265 select PCI_DOMAINS_GENERIC if PCI 266 select PCI_ECAM if (ACPI && PCI) 267 select PCI_SYSCALL if PCI 268 select POWER_RESET 269 select POWER_SUPPLY 270 select SPARSE_IRQ 271 select SWIOTLB 272 select SYSCTL_EXCEPTION_TRACE 273 select THREAD_INFO_IN_TASK 274 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 275 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 276 select TRACE_IRQFLAGS_SUPPORT 277 select TRACE_IRQFLAGS_NMI_SUPPORT 278 select HAVE_SOFTIRQ_ON_OWN_STACK 279 select USER_STACKTRACE_SUPPORT 280 select VDSO_GETRANDOM 281 select VMAP_STACK 282 help 283 ARM 64-bit (AArch64) Linux support. 284 285config RUSTC_SUPPORTS_ARM64 286 def_bool y 287 depends on CPU_LITTLE_ENDIAN 288 # Shadow call stack is only supported on certain rustc versions. 289 # 290 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 291 # required due to use of the -Zfixed-x18 flag. 292 # 293 # Otherwise, rustc version 1.82+ is required due to use of the 294 # -Zsanitizer=shadow-call-stack flag. 295 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 296 297config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 298 def_bool CC_IS_CLANG 299 # https://github.com/ClangBuiltLinux/linux/issues/1507 300 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 301 302config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 303 def_bool CC_IS_GCC 304 depends on $(cc-option,-fpatchable-function-entry=2) 305 306config 64BIT 307 def_bool y 308 309config MMU 310 def_bool y 311 312config ARM64_CONT_PTE_SHIFT 313 int 314 default 5 if PAGE_SIZE_64KB 315 default 7 if PAGE_SIZE_16KB 316 default 4 317 318config ARM64_CONT_PMD_SHIFT 319 int 320 default 5 if PAGE_SIZE_64KB 321 default 5 if PAGE_SIZE_16KB 322 default 4 323 324config ARCH_MMAP_RND_BITS_MIN 325 default 14 if PAGE_SIZE_64KB 326 default 16 if PAGE_SIZE_16KB 327 default 18 328 329# max bits determined by the following formula: 330# VA_BITS - PTDESC_TABLE_SHIFT 331config ARCH_MMAP_RND_BITS_MAX 332 default 19 if ARM64_VA_BITS=36 333 default 24 if ARM64_VA_BITS=39 334 default 27 if ARM64_VA_BITS=42 335 default 30 if ARM64_VA_BITS=47 336 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 337 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 338 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 339 default 14 if ARM64_64K_PAGES 340 default 16 if ARM64_16K_PAGES 341 default 18 342 343config ARCH_MMAP_RND_COMPAT_BITS_MIN 344 default 7 if ARM64_64K_PAGES 345 default 9 if ARM64_16K_PAGES 346 default 11 347 348config ARCH_MMAP_RND_COMPAT_BITS_MAX 349 default 16 350 351config NO_IOPORT_MAP 352 def_bool y if !PCI 353 354config STACKTRACE_SUPPORT 355 def_bool y 356 357config ILLEGAL_POINTER_VALUE 358 hex 359 default 0xdead000000000000 360 361config LOCKDEP_SUPPORT 362 def_bool y 363 364config GENERIC_BUG 365 def_bool y 366 depends on BUG 367 368config GENERIC_BUG_RELATIVE_POINTERS 369 def_bool y 370 depends on GENERIC_BUG 371 372config GENERIC_HWEIGHT 373 def_bool y 374 375config GENERIC_CSUM 376 def_bool y 377 378config GENERIC_CALIBRATE_DELAY 379 def_bool y 380 381config SMP 382 def_bool y 383 384config KERNEL_MODE_NEON 385 def_bool y 386 387config FIX_EARLYCON_MEM 388 def_bool y 389 390config PGTABLE_LEVELS 391 int 392 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 393 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 394 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 395 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 396 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 397 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 398 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 399 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 400 401config ARCH_SUPPORTS_UPROBES 402 def_bool y 403 404config ARCH_PROC_KCORE_TEXT 405 def_bool y 406 407config BROKEN_GAS_INST 408 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 409 410config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 411 bool 412 # Clang's __builtin_return_address() strips the PAC since 12.0.0 413 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 414 default y if CC_IS_CLANG 415 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 416 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 417 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 418 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 419 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 420 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 421 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 422 default n 423 424config KASAN_SHADOW_OFFSET 425 hex 426 depends on KASAN_GENERIC || KASAN_SW_TAGS 427 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 428 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 429 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 430 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 431 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 432 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 433 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 434 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 435 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 436 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 437 default 0xffffffffffffffff 438 439config UNWIND_TABLES 440 bool 441 442source "arch/arm64/Kconfig.platforms" 443 444menu "Kernel Features" 445 446menu "ARM errata workarounds via the alternatives framework" 447 448config AMPERE_ERRATUM_AC03_CPU_38 449 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 450 default y 451 help 452 This option adds an alternative code sequence to work around Ampere 453 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 454 455 The affected design reports FEAT_HAFDBS as not implemented in 456 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 457 as required by the architecture. The unadvertised HAFDBS 458 implementation suffers from an additional erratum where hardware 459 A/D updates can occur after a PTE has been marked invalid. 460 461 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 462 which avoids enabling unadvertised hardware Access Flag management 463 at stage-2. 464 465 If unsure, say Y. 466 467config AMPERE_ERRATUM_AC04_CPU_23 468 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 469 default y 470 help 471 This option adds an alternative code sequence to work around Ampere 472 errata AC04_CPU_23 on AmpereOne. 473 474 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 475 data addresses initiated by load/store instructions. Only 476 instruction initiated translations are vulnerable, not translations 477 from prefetches for example. A DSB before the store to HCR_EL2 is 478 sufficient to prevent older instructions from hitting the window 479 for corruption, and an ISB after is sufficient to prevent younger 480 instructions from hitting the window for corruption. 481 482 If unsure, say Y. 483 484config ARM64_WORKAROUND_CLEAN_CACHE 485 bool 486 487config ARM64_ERRATUM_826319 488 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 489 default y 490 select ARM64_WORKAROUND_CLEAN_CACHE 491 help 492 This option adds an alternative code sequence to work around ARM 493 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 494 AXI master interface and an L2 cache. 495 496 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 497 and is unable to accept a certain write via this interface, it will 498 not progress on read data presented on the read data channel and the 499 system can deadlock. 500 501 The workaround promotes data cache clean instructions to 502 data cache clean-and-invalidate. 503 Please note that this does not necessarily enable the workaround, 504 as it depends on the alternative framework, which will only patch 505 the kernel if an affected CPU is detected. 506 507 If unsure, say Y. 508 509config ARM64_ERRATUM_827319 510 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 511 default y 512 select ARM64_WORKAROUND_CLEAN_CACHE 513 help 514 This option adds an alternative code sequence to work around ARM 515 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 516 master interface and an L2 cache. 517 518 Under certain conditions this erratum can cause a clean line eviction 519 to occur at the same time as another transaction to the same address 520 on the AMBA 5 CHI interface, which can cause data corruption if the 521 interconnect reorders the two transactions. 522 523 The workaround promotes data cache clean instructions to 524 data cache clean-and-invalidate. 525 Please note that this does not necessarily enable the workaround, 526 as it depends on the alternative framework, which will only patch 527 the kernel if an affected CPU is detected. 528 529 If unsure, say Y. 530 531config ARM64_ERRATUM_824069 532 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 533 default y 534 select ARM64_WORKAROUND_CLEAN_CACHE 535 help 536 This option adds an alternative code sequence to work around ARM 537 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 538 to a coherent interconnect. 539 540 If a Cortex-A53 processor is executing a store or prefetch for 541 write instruction at the same time as a processor in another 542 cluster is executing a cache maintenance operation to the same 543 address, then this erratum might cause a clean cache line to be 544 incorrectly marked as dirty. 545 546 The workaround promotes data cache clean instructions to 547 data cache clean-and-invalidate. 548 Please note that this option does not necessarily enable the 549 workaround, as it depends on the alternative framework, which will 550 only patch the kernel if an affected CPU is detected. 551 552 If unsure, say Y. 553 554config ARM64_ERRATUM_819472 555 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 556 default y 557 select ARM64_WORKAROUND_CLEAN_CACHE 558 help 559 This option adds an alternative code sequence to work around ARM 560 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 561 present when it is connected to a coherent interconnect. 562 563 If the processor is executing a load and store exclusive sequence at 564 the same time as a processor in another cluster is executing a cache 565 maintenance operation to the same address, then this erratum might 566 cause data corruption. 567 568 The workaround promotes data cache clean instructions to 569 data cache clean-and-invalidate. 570 Please note that this does not necessarily enable the workaround, 571 as it depends on the alternative framework, which will only patch 572 the kernel if an affected CPU is detected. 573 574 If unsure, say Y. 575 576config ARM64_ERRATUM_832075 577 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 578 default y 579 help 580 This option adds an alternative code sequence to work around ARM 581 erratum 832075 on Cortex-A57 parts up to r1p2. 582 583 Affected Cortex-A57 parts might deadlock when exclusive load/store 584 instructions to Write-Back memory are mixed with Device loads. 585 586 The workaround is to promote device loads to use Load-Acquire 587 semantics. 588 Please note that this does not necessarily enable the workaround, 589 as it depends on the alternative framework, which will only patch 590 the kernel if an affected CPU is detected. 591 592 If unsure, say Y. 593 594config ARM64_ERRATUM_834220 595 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 596 depends on KVM 597 help 598 This option adds an alternative code sequence to work around ARM 599 erratum 834220 on Cortex-A57 parts up to r1p2. 600 601 Affected Cortex-A57 parts might report a Stage 2 translation 602 fault as the result of a Stage 1 fault for load crossing a 603 page boundary when there is a permission or device memory 604 alignment fault at Stage 1 and a translation fault at Stage 2. 605 606 The workaround is to verify that the Stage 1 translation 607 doesn't generate a fault before handling the Stage 2 fault. 608 Please note that this does not necessarily enable the workaround, 609 as it depends on the alternative framework, which will only patch 610 the kernel if an affected CPU is detected. 611 612 If unsure, say N. 613 614config ARM64_ERRATUM_1742098 615 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 616 depends on COMPAT 617 default y 618 help 619 This option removes the AES hwcap for aarch32 user-space to 620 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 621 622 Affected parts may corrupt the AES state if an interrupt is 623 taken between a pair of AES instructions. These instructions 624 are only present if the cryptography extensions are present. 625 All software should have a fallback implementation for CPUs 626 that don't implement the cryptography extensions. 627 628 If unsure, say Y. 629 630config ARM64_ERRATUM_845719 631 bool "Cortex-A53: 845719: a load might read incorrect data" 632 depends on COMPAT 633 default y 634 help 635 This option adds an alternative code sequence to work around ARM 636 erratum 845719 on Cortex-A53 parts up to r0p4. 637 638 When running a compat (AArch32) userspace on an affected Cortex-A53 639 part, a load at EL0 from a virtual address that matches the bottom 32 640 bits of the virtual address used by a recent load at (AArch64) EL1 641 might return incorrect data. 642 643 The workaround is to write the contextidr_el1 register on exception 644 return to a 32-bit task. 645 Please note that this does not necessarily enable the workaround, 646 as it depends on the alternative framework, which will only patch 647 the kernel if an affected CPU is detected. 648 649 If unsure, say Y. 650 651config ARM64_ERRATUM_843419 652 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 653 default y 654 help 655 This option links the kernel with '--fix-cortex-a53-843419' and 656 enables PLT support to replace certain ADRP instructions, which can 657 cause subsequent memory accesses to use an incorrect address on 658 Cortex-A53 parts up to r0p4. 659 660 If unsure, say Y. 661 662config ARM64_ERRATUM_1024718 663 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 664 default y 665 help 666 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 667 668 Affected Cortex-A55 cores (all revisions) could cause incorrect 669 update of the hardware dirty bit when the DBM/AP bits are updated 670 without a break-before-make. The workaround is to disable the usage 671 of hardware DBM locally on the affected cores. CPUs not affected by 672 this erratum will continue to use the feature. 673 674 If unsure, say Y. 675 676config ARM64_ERRATUM_1418040 677 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 678 default y 679 depends on COMPAT 680 help 681 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 682 errata 1188873 and 1418040. 683 684 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 685 cause register corruption when accessing the timer registers 686 from AArch32 userspace. 687 688 If unsure, say Y. 689 690config ARM64_WORKAROUND_SPECULATIVE_AT 691 bool 692 693config ARM64_ERRATUM_1165522 694 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 695 default y 696 select ARM64_WORKAROUND_SPECULATIVE_AT 697 help 698 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 699 700 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 701 corrupted TLBs by speculating an AT instruction during a guest 702 context switch. 703 704 If unsure, say Y. 705 706config ARM64_ERRATUM_1319367 707 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 708 default y 709 select ARM64_WORKAROUND_SPECULATIVE_AT 710 help 711 This option adds work arounds for ARM Cortex-A57 erratum 1319537 712 and A72 erratum 1319367 713 714 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 715 speculating an AT instruction during a guest context switch. 716 717 If unsure, say Y. 718 719config ARM64_ERRATUM_1530923 720 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 721 default y 722 select ARM64_WORKAROUND_SPECULATIVE_AT 723 help 724 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 725 726 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 727 corrupted TLBs by speculating an AT instruction during a guest 728 context switch. 729 730 If unsure, say Y. 731 732config ARM64_WORKAROUND_REPEAT_TLBI 733 bool 734 735config ARM64_ERRATUM_2441007 736 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 737 select ARM64_WORKAROUND_REPEAT_TLBI 738 help 739 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 740 741 Under very rare circumstances, affected Cortex-A55 CPUs 742 may not handle a race between a break-before-make sequence on one 743 CPU, and another CPU accessing the same page. This could allow a 744 store to a page that has been unmapped. 745 746 Work around this by adding the affected CPUs to the list that needs 747 TLB sequences to be done twice. 748 749 If unsure, say N. 750 751config ARM64_ERRATUM_1286807 752 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 753 select ARM64_WORKAROUND_REPEAT_TLBI 754 help 755 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 756 757 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 758 address for a cacheable mapping of a location is being 759 accessed by a core while another core is remapping the virtual 760 address to a new physical page using the recommended 761 break-before-make sequence, then under very rare circumstances 762 TLBI+DSB completes before a read using the translation being 763 invalidated has been observed by other observers. The 764 workaround repeats the TLBI+DSB operation. 765 766 If unsure, say N. 767 768config ARM64_ERRATUM_1463225 769 bool "Cortex-A76: Software Step might prevent interrupt recognition" 770 default y 771 help 772 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 773 774 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 775 of a system call instruction (SVC) can prevent recognition of 776 subsequent interrupts when software stepping is disabled in the 777 exception handler of the system call and either kernel debugging 778 is enabled or VHE is in use. 779 780 Work around the erratum by triggering a dummy step exception 781 when handling a system call from a task that is being stepped 782 in a VHE configuration of the kernel. 783 784 If unsure, say Y. 785 786config ARM64_ERRATUM_1542419 787 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 788 help 789 This option adds a workaround for ARM Neoverse-N1 erratum 790 1542419. 791 792 Affected Neoverse-N1 cores could execute a stale instruction when 793 modified by another CPU. The workaround depends on a firmware 794 counterpart. 795 796 Workaround the issue by hiding the DIC feature from EL0. This 797 forces user-space to perform cache maintenance. 798 799 If unsure, say N. 800 801config ARM64_ERRATUM_1508412 802 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 803 default y 804 help 805 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 806 807 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 808 of a store-exclusive or read of PAR_EL1 and a load with device or 809 non-cacheable memory attributes. The workaround depends on a firmware 810 counterpart. 811 812 KVM guests must also have the workaround implemented or they can 813 deadlock the system. 814 815 Work around the issue by inserting DMB SY barriers around PAR_EL1 816 register reads and warning KVM users. The DMB barrier is sufficient 817 to prevent a speculative PAR_EL1 read. 818 819 If unsure, say Y. 820 821config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 822 bool 823 824config ARM64_ERRATUM_2051678 825 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 826 default y 827 help 828 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 829 Affected Cortex-A510 might not respect the ordering rules for 830 hardware update of the page table's dirty bit. The workaround 831 is to not enable the feature on affected CPUs. 832 833 If unsure, say Y. 834 835config ARM64_ERRATUM_2077057 836 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 837 default y 838 help 839 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 840 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 841 expected, but a Pointer Authentication trap is taken instead. The 842 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 843 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 844 845 This can only happen when EL2 is stepping EL1. 846 847 When these conditions occur, the SPSR_EL2 value is unchanged from the 848 previous guest entry, and can be restored from the in-memory copy. 849 850 If unsure, say Y. 851 852config ARM64_ERRATUM_2658417 853 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 854 default y 855 help 856 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 857 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 858 BFMMLA or VMMLA instructions in rare circumstances when a pair of 859 A510 CPUs are using shared neon hardware. As the sharing is not 860 discoverable by the kernel, hide the BF16 HWCAP to indicate that 861 user-space should not be using these instructions. 862 863 If unsure, say Y. 864 865config ARM64_ERRATUM_2119858 866 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 867 default y 868 depends on CORESIGHT_TRBE 869 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 870 help 871 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 872 873 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 874 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 875 the event of a WRAP event. 876 877 Work around the issue by always making sure we move the TRBPTR_EL1 by 878 256 bytes before enabling the buffer and filling the first 256 bytes of 879 the buffer with ETM ignore packets upon disabling. 880 881 If unsure, say Y. 882 883config ARM64_ERRATUM_2139208 884 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 885 default y 886 depends on CORESIGHT_TRBE 887 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 888 help 889 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 890 891 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 892 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 893 the event of a WRAP event. 894 895 Work around the issue by always making sure we move the TRBPTR_EL1 by 896 256 bytes before enabling the buffer and filling the first 256 bytes of 897 the buffer with ETM ignore packets upon disabling. 898 899 If unsure, say Y. 900 901config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 902 bool 903 904config ARM64_ERRATUM_2054223 905 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 906 default y 907 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 908 help 909 Enable workaround for ARM Cortex-A710 erratum 2054223 910 911 Affected cores may fail to flush the trace data on a TSB instruction, when 912 the PE is in trace prohibited state. This will cause losing a few bytes 913 of the trace cached. 914 915 Workaround is to issue two TSB consecutively on affected cores. 916 917 If unsure, say Y. 918 919config ARM64_ERRATUM_2067961 920 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 921 default y 922 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 923 help 924 Enable workaround for ARM Neoverse-N2 erratum 2067961 925 926 Affected cores may fail to flush the trace data on a TSB instruction, when 927 the PE is in trace prohibited state. This will cause losing a few bytes 928 of the trace cached. 929 930 Workaround is to issue two TSB consecutively on affected cores. 931 932 If unsure, say Y. 933 934config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 935 bool 936 937config ARM64_ERRATUM_2253138 938 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 939 depends on CORESIGHT_TRBE 940 default y 941 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 942 help 943 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 944 945 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 946 for TRBE. Under some conditions, the TRBE might generate a write to the next 947 virtually addressed page following the last page of the TRBE address space 948 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 949 950 Work around this in the driver by always making sure that there is a 951 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 952 953 If unsure, say Y. 954 955config ARM64_ERRATUM_2224489 956 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 957 depends on CORESIGHT_TRBE 958 default y 959 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 960 help 961 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 962 963 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 964 for TRBE. Under some conditions, the TRBE might generate a write to the next 965 virtually addressed page following the last page of the TRBE address space 966 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 967 968 Work around this in the driver by always making sure that there is a 969 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 970 971 If unsure, say Y. 972 973config ARM64_ERRATUM_2441009 974 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 975 select ARM64_WORKAROUND_REPEAT_TLBI 976 help 977 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 978 979 Under very rare circumstances, affected Cortex-A510 CPUs 980 may not handle a race between a break-before-make sequence on one 981 CPU, and another CPU accessing the same page. This could allow a 982 store to a page that has been unmapped. 983 984 Work around this by adding the affected CPUs to the list that needs 985 TLB sequences to be done twice. 986 987 If unsure, say N. 988 989config ARM64_ERRATUM_2064142 990 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 991 depends on CORESIGHT_TRBE 992 default y 993 help 994 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 995 996 Affected Cortex-A510 core might fail to write into system registers after the 997 TRBE has been disabled. Under some conditions after the TRBE has been disabled 998 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 999 and TRBTRG_EL1 will be ignored and will not be effected. 1000 1001 Work around this in the driver by executing TSB CSYNC and DSB after collection 1002 is stopped and before performing a system register write to one of the affected 1003 registers. 1004 1005 If unsure, say Y. 1006 1007config ARM64_ERRATUM_2038923 1008 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1009 depends on CORESIGHT_TRBE 1010 default y 1011 help 1012 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1013 1014 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1015 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1016 might be corrupted. This happens after TRBE buffer has been enabled by setting 1017 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1018 execution changes from a context, in which trace is prohibited to one where it 1019 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1020 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1021 the trace buffer state might be corrupted. 1022 1023 Work around this in the driver by preventing an inconsistent view of whether the 1024 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1025 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1026 two ISB instructions if no ERET is to take place. 1027 1028 If unsure, say Y. 1029 1030config ARM64_ERRATUM_1902691 1031 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1032 depends on CORESIGHT_TRBE 1033 default y 1034 help 1035 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1036 1037 Affected Cortex-A510 core might cause trace data corruption, when being written 1038 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1039 trace data. 1040 1041 Work around this problem in the driver by just preventing TRBE initialization on 1042 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1043 on such implementations. This will cover the kernel for any firmware that doesn't 1044 do this already. 1045 1046 If unsure, say Y. 1047 1048config ARM64_ERRATUM_2457168 1049 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1050 depends on ARM64_AMU_EXTN 1051 default y 1052 help 1053 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1054 1055 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1056 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1057 incorrectly giving a significantly higher output value. 1058 1059 Work around this problem by returning 0 when reading the affected counter in 1060 key locations that results in disabling all users of this counter. This effect 1061 is the same to firmware disabling affected counters. 1062 1063 If unsure, say Y. 1064 1065config ARM64_ERRATUM_2645198 1066 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1067 default y 1068 help 1069 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1070 1071 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1072 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1073 next instruction abort caused by permission fault. 1074 1075 Only user-space does executable to non-executable permission transition via 1076 mprotect() system call. Workaround the problem by doing a break-before-make 1077 TLB invalidation, for all changes to executable user space mappings. 1078 1079 If unsure, say Y. 1080 1081config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1082 bool 1083 1084config ARM64_ERRATUM_2966298 1085 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1086 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1087 default y 1088 help 1089 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1090 1091 On an affected Cortex-A520 core, a speculatively executed unprivileged 1092 load might leak data from a privileged level via a cache side channel. 1093 1094 Work around this problem by executing a TLBI before returning to EL0. 1095 1096 If unsure, say Y. 1097 1098config ARM64_ERRATUM_3117295 1099 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1100 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1101 default y 1102 help 1103 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1104 1105 On an affected Cortex-A510 core, a speculatively executed unprivileged 1106 load might leak data from a privileged level via a cache side channel. 1107 1108 Work around this problem by executing a TLBI before returning to EL0. 1109 1110 If unsure, say Y. 1111 1112config ARM64_ERRATUM_3194386 1113 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1114 default y 1115 help 1116 This option adds the workaround for the following errata: 1117 1118 * ARM Cortex-A76 erratum 3324349 1119 * ARM Cortex-A77 erratum 3324348 1120 * ARM Cortex-A78 erratum 3324344 1121 * ARM Cortex-A78C erratum 3324346 1122 * ARM Cortex-A78C erratum 3324347 1123 * ARM Cortex-A710 erratam 3324338 1124 * ARM Cortex-A715 errartum 3456084 1125 * ARM Cortex-A720 erratum 3456091 1126 * ARM Cortex-A725 erratum 3456106 1127 * ARM Cortex-X1 erratum 3324344 1128 * ARM Cortex-X1C erratum 3324346 1129 * ARM Cortex-X2 erratum 3324338 1130 * ARM Cortex-X3 erratum 3324335 1131 * ARM Cortex-X4 erratum 3194386 1132 * ARM Cortex-X925 erratum 3324334 1133 * ARM Neoverse-N1 erratum 3324349 1134 * ARM Neoverse N2 erratum 3324339 1135 * ARM Neoverse-N3 erratum 3456111 1136 * ARM Neoverse-V1 erratum 3324341 1137 * ARM Neoverse V2 erratum 3324336 1138 * ARM Neoverse-V3 erratum 3312417 1139 1140 On affected cores "MSR SSBS, #0" instructions may not affect 1141 subsequent speculative instructions, which may permit unexepected 1142 speculative store bypassing. 1143 1144 Work around this problem by placing a Speculation Barrier (SB) or 1145 Instruction Synchronization Barrier (ISB) after kernel changes to 1146 SSBS. The presence of the SSBS special-purpose register is hidden 1147 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1148 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1149 1150 If unsure, say Y. 1151 1152config CAVIUM_ERRATUM_22375 1153 bool "Cavium erratum 22375, 24313" 1154 default y 1155 help 1156 Enable workaround for errata 22375 and 24313. 1157 1158 This implements two gicv3-its errata workarounds for ThunderX. Both 1159 with a small impact affecting only ITS table allocation. 1160 1161 erratum 22375: only alloc 8MB table size 1162 erratum 24313: ignore memory access type 1163 1164 The fixes are in ITS initialization and basically ignore memory access 1165 type and table size provided by the TYPER and BASER registers. 1166 1167 If unsure, say Y. 1168 1169config CAVIUM_ERRATUM_23144 1170 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1171 depends on NUMA 1172 default y 1173 help 1174 ITS SYNC command hang for cross node io and collections/cpu mapping. 1175 1176 If unsure, say Y. 1177 1178config CAVIUM_ERRATUM_23154 1179 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1180 default y 1181 help 1182 The ThunderX GICv3 implementation requires a modified version for 1183 reading the IAR status to ensure data synchronization 1184 (access to icc_iar1_el1 is not sync'ed before and after). 1185 1186 It also suffers from erratum 38545 (also present on Marvell's 1187 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1188 spuriously presented to the CPU interface. 1189 1190 If unsure, say Y. 1191 1192config CAVIUM_ERRATUM_27456 1193 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1194 default y 1195 help 1196 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1197 instructions may cause the icache to become corrupted if it 1198 contains data for a non-current ASID. The fix is to 1199 invalidate the icache when changing the mm context. 1200 1201 If unsure, say Y. 1202 1203config CAVIUM_ERRATUM_30115 1204 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1205 default y 1206 help 1207 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1208 1.2, and T83 Pass 1.0, KVM guest execution may disable 1209 interrupts in host. Trapping both GICv3 group-0 and group-1 1210 accesses sidesteps the issue. 1211 1212 If unsure, say Y. 1213 1214config CAVIUM_TX2_ERRATUM_219 1215 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1216 default y 1217 help 1218 On Cavium ThunderX2, a load, store or prefetch instruction between a 1219 TTBR update and the corresponding context synchronizing operation can 1220 cause a spurious Data Abort to be delivered to any hardware thread in 1221 the CPU core. 1222 1223 Work around the issue by avoiding the problematic code sequence and 1224 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1225 trap handler performs the corresponding register access, skips the 1226 instruction and ensures context synchronization by virtue of the 1227 exception return. 1228 1229 If unsure, say Y. 1230 1231config FUJITSU_ERRATUM_010001 1232 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1233 default y 1234 help 1235 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1236 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1237 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1238 This fault occurs under a specific hardware condition when a 1239 load/store instruction performs an address translation using: 1240 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1241 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1242 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1243 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1244 1245 The workaround is to ensure these bits are clear in TCR_ELx. 1246 The workaround only affects the Fujitsu-A64FX. 1247 1248 If unsure, say Y. 1249 1250config HISILICON_ERRATUM_161600802 1251 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1252 default y 1253 help 1254 The HiSilicon Hip07 SoC uses the wrong redistributor base 1255 when issued ITS commands such as VMOVP and VMAPP, and requires 1256 a 128kB offset to be applied to the target address in this commands. 1257 1258 If unsure, say Y. 1259 1260config HISILICON_ERRATUM_162100801 1261 bool "Hip09 162100801 erratum support" 1262 default y 1263 help 1264 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1265 during unmapping operation, which will cause some vSGIs lost. 1266 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1267 after VMOVP. 1268 1269 If unsure, say Y. 1270 1271config QCOM_FALKOR_ERRATUM_1003 1272 bool "Falkor E1003: Incorrect translation due to ASID change" 1273 default y 1274 help 1275 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1276 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1277 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1278 then only for entries in the walk cache, since the leaf translation 1279 is unchanged. Work around the erratum by invalidating the walk cache 1280 entries for the trampoline before entering the kernel proper. 1281 1282config QCOM_FALKOR_ERRATUM_1009 1283 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1284 default y 1285 select ARM64_WORKAROUND_REPEAT_TLBI 1286 help 1287 On Falkor v1, the CPU may prematurely complete a DSB following a 1288 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1289 one more time to fix the issue. 1290 1291 If unsure, say Y. 1292 1293config QCOM_QDF2400_ERRATUM_0065 1294 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1295 default y 1296 help 1297 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1298 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1299 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1300 1301 If unsure, say Y. 1302 1303config QCOM_FALKOR_ERRATUM_E1041 1304 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1305 default y 1306 help 1307 Falkor CPU may speculatively fetch instructions from an improper 1308 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1309 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1310 1311 If unsure, say Y. 1312 1313config NVIDIA_CARMEL_CNP_ERRATUM 1314 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1315 default y 1316 help 1317 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1318 invalidate shared TLB entries installed by a different core, as it would 1319 on standard ARM cores. 1320 1321 If unsure, say Y. 1322 1323config ROCKCHIP_ERRATUM_3568002 1324 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1325 default y 1326 help 1327 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1328 addressing limited to the first 32bit of physical address space. 1329 1330 If unsure, say Y. 1331 1332config ROCKCHIP_ERRATUM_3588001 1333 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1334 default y 1335 help 1336 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1337 This means, that its sharability feature may not be used, even though it 1338 is supported by the IP itself. 1339 1340 If unsure, say Y. 1341 1342config SOCIONEXT_SYNQUACER_PREITS 1343 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1344 default y 1345 help 1346 Socionext Synquacer SoCs implement a separate h/w block to generate 1347 MSI doorbell writes with non-zero values for the device ID. 1348 1349 If unsure, say Y. 1350 1351endmenu # "ARM errata workarounds via the alternatives framework" 1352 1353choice 1354 prompt "Page size" 1355 default ARM64_4K_PAGES 1356 help 1357 Page size (translation granule) configuration. 1358 1359config ARM64_4K_PAGES 1360 bool "4KB" 1361 select HAVE_PAGE_SIZE_4KB 1362 help 1363 This feature enables 4KB pages support. 1364 1365config ARM64_16K_PAGES 1366 bool "16KB" 1367 select HAVE_PAGE_SIZE_16KB 1368 help 1369 The system will use 16KB pages support. AArch32 emulation 1370 requires applications compiled with 16K (or a multiple of 16K) 1371 aligned segments. 1372 1373config ARM64_64K_PAGES 1374 bool "64KB" 1375 select HAVE_PAGE_SIZE_64KB 1376 help 1377 This feature enables 64KB pages support (4KB by default) 1378 allowing only two levels of page tables and faster TLB 1379 look-up. AArch32 emulation requires applications compiled 1380 with 64K aligned segments. 1381 1382endchoice 1383 1384choice 1385 prompt "Virtual address space size" 1386 default ARM64_VA_BITS_52 1387 help 1388 Allows choosing one of multiple possible virtual address 1389 space sizes. The level of translation table is determined by 1390 a combination of page size and virtual address space size. 1391 1392config ARM64_VA_BITS_36 1393 bool "36-bit" if EXPERT 1394 depends on PAGE_SIZE_16KB 1395 1396config ARM64_VA_BITS_39 1397 bool "39-bit" 1398 depends on PAGE_SIZE_4KB 1399 1400config ARM64_VA_BITS_42 1401 bool "42-bit" 1402 depends on PAGE_SIZE_64KB 1403 1404config ARM64_VA_BITS_47 1405 bool "47-bit" 1406 depends on PAGE_SIZE_16KB 1407 1408config ARM64_VA_BITS_48 1409 bool "48-bit" 1410 1411config ARM64_VA_BITS_52 1412 bool "52-bit" 1413 help 1414 Enable 52-bit virtual addressing for userspace when explicitly 1415 requested via a hint to mmap(). The kernel will also use 52-bit 1416 virtual addresses for its own mappings (provided HW support for 1417 this feature is available, otherwise it reverts to 48-bit). 1418 1419 NOTE: Enabling 52-bit virtual addressing in conjunction with 1420 ARMv8.3 Pointer Authentication will result in the PAC being 1421 reduced from 7 bits to 3 bits, which may have a significant 1422 impact on its susceptibility to brute-force attacks. 1423 1424 If unsure, select 48-bit virtual addressing instead. 1425 1426endchoice 1427 1428config ARM64_FORCE_52BIT 1429 bool "Force 52-bit virtual addresses for userspace" 1430 depends on ARM64_VA_BITS_52 && EXPERT 1431 help 1432 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1433 to maintain compatibility with older software by providing 48-bit VAs 1434 unless a hint is supplied to mmap. 1435 1436 This configuration option disables the 48-bit compatibility logic, and 1437 forces all userspace addresses to be 52-bit on HW that supports it. One 1438 should only enable this configuration option for stress testing userspace 1439 memory management code. If unsure say N here. 1440 1441config ARM64_VA_BITS 1442 int 1443 default 36 if ARM64_VA_BITS_36 1444 default 39 if ARM64_VA_BITS_39 1445 default 42 if ARM64_VA_BITS_42 1446 default 47 if ARM64_VA_BITS_47 1447 default 48 if ARM64_VA_BITS_48 1448 default 52 if ARM64_VA_BITS_52 1449 1450choice 1451 prompt "Physical address space size" 1452 default ARM64_PA_BITS_48 1453 help 1454 Choose the maximum physical address range that the kernel will 1455 support. 1456 1457config ARM64_PA_BITS_48 1458 bool "48-bit" 1459 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1460 1461config ARM64_PA_BITS_52 1462 bool "52-bit" 1463 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1464 help 1465 Enable support for a 52-bit physical address space, introduced as 1466 part of the ARMv8.2-LPA extension. 1467 1468 With this enabled, the kernel will also continue to work on CPUs that 1469 do not support ARMv8.2-LPA, but with some added memory overhead (and 1470 minor performance overhead). 1471 1472endchoice 1473 1474config ARM64_PA_BITS 1475 int 1476 default 48 if ARM64_PA_BITS_48 1477 default 52 if ARM64_PA_BITS_52 1478 1479config ARM64_LPA2 1480 def_bool y 1481 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1482 1483choice 1484 prompt "Endianness" 1485 default CPU_LITTLE_ENDIAN 1486 help 1487 Select the endianness of data accesses performed by the CPU. Userspace 1488 applications will need to be compiled and linked for the endianness 1489 that is selected here. 1490 1491config CPU_BIG_ENDIAN 1492 bool "Build big-endian kernel" 1493 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1494 depends on AS_IS_GNU || AS_VERSION >= 150000 1495 help 1496 Say Y if you plan on running a kernel with a big-endian userspace. 1497 1498config CPU_LITTLE_ENDIAN 1499 bool "Build little-endian kernel" 1500 help 1501 Say Y if you plan on running a kernel with a little-endian userspace. 1502 This is usually the case for distributions targeting arm64. 1503 1504endchoice 1505 1506config SCHED_MC 1507 bool "Multi-core scheduler support" 1508 help 1509 Multi-core scheduler support improves the CPU scheduler's decision 1510 making when dealing with multi-core CPU chips at a cost of slightly 1511 increased overhead in some places. If unsure say N here. 1512 1513config SCHED_CLUSTER 1514 bool "Cluster scheduler support" 1515 help 1516 Cluster scheduler support improves the CPU scheduler's decision 1517 making when dealing with machines that have clusters of CPUs. 1518 Cluster usually means a couple of CPUs which are placed closely 1519 by sharing mid-level caches, last-level cache tags or internal 1520 busses. 1521 1522config SCHED_SMT 1523 bool "SMT scheduler support" 1524 help 1525 Improves the CPU scheduler's decision making when dealing with 1526 MultiThreading at a cost of slightly increased overhead in some 1527 places. If unsure say N here. 1528 1529config NR_CPUS 1530 int "Maximum number of CPUs (2-4096)" 1531 range 2 4096 1532 default "512" 1533 1534config HOTPLUG_CPU 1535 bool "Support for hot-pluggable CPUs" 1536 select GENERIC_IRQ_MIGRATION 1537 help 1538 Say Y here to experiment with turning CPUs off and on. CPUs 1539 can be controlled through /sys/devices/system/cpu. 1540 1541# Common NUMA Features 1542config NUMA 1543 bool "NUMA Memory Allocation and Scheduler Support" 1544 select GENERIC_ARCH_NUMA 1545 select OF_NUMA 1546 select HAVE_SETUP_PER_CPU_AREA 1547 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1548 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1549 select USE_PERCPU_NUMA_NODE_ID 1550 help 1551 Enable NUMA (Non-Uniform Memory Access) support. 1552 1553 The kernel will try to allocate memory used by a CPU on the 1554 local memory of the CPU and add some more 1555 NUMA awareness to the kernel. 1556 1557config NODES_SHIFT 1558 int "Maximum NUMA Nodes (as a power of 2)" 1559 range 1 10 1560 default "4" 1561 depends on NUMA 1562 help 1563 Specify the maximum number of NUMA Nodes available on the target 1564 system. Increases memory reserved to accommodate various tables. 1565 1566source "kernel/Kconfig.hz" 1567 1568config ARCH_SPARSEMEM_ENABLE 1569 def_bool y 1570 select SPARSEMEM_VMEMMAP_ENABLE 1571 select SPARSEMEM_VMEMMAP 1572 1573config HW_PERF_EVENTS 1574 def_bool y 1575 depends on ARM_PMU 1576 1577# Supported by clang >= 7.0 or GCC >= 12.0.0 1578config CC_HAVE_SHADOW_CALL_STACK 1579 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1580 1581config PARAVIRT 1582 bool "Enable paravirtualization code" 1583 help 1584 This changes the kernel so it can modify itself when it is run 1585 under a hypervisor, potentially improving performance significantly 1586 over full virtualization. 1587 1588config PARAVIRT_TIME_ACCOUNTING 1589 bool "Paravirtual steal time accounting" 1590 select PARAVIRT 1591 help 1592 Select this option to enable fine granularity task steal time 1593 accounting. Time spent executing other tasks in parallel with 1594 the current vCPU is discounted from the vCPU power. To account for 1595 that, there can be a small performance impact. 1596 1597 If in doubt, say N here. 1598 1599config ARCH_SUPPORTS_KEXEC 1600 def_bool PM_SLEEP_SMP 1601 1602config ARCH_SUPPORTS_KEXEC_FILE 1603 def_bool y 1604 1605config ARCH_SELECTS_KEXEC_FILE 1606 def_bool y 1607 depends on KEXEC_FILE 1608 select HAVE_IMA_KEXEC if IMA 1609 1610config ARCH_SUPPORTS_KEXEC_SIG 1611 def_bool y 1612 1613config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1614 def_bool y 1615 1616config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1617 def_bool y 1618 1619config ARCH_SUPPORTS_KEXEC_HANDOVER 1620 def_bool y 1621 1622config ARCH_SUPPORTS_CRASH_DUMP 1623 def_bool y 1624 1625config ARCH_DEFAULT_CRASH_DUMP 1626 def_bool y 1627 1628config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1629 def_bool CRASH_RESERVE 1630 1631config TRANS_TABLE 1632 def_bool y 1633 depends on HIBERNATION || KEXEC_CORE 1634 1635config XEN_DOM0 1636 def_bool y 1637 depends on XEN 1638 1639config XEN 1640 bool "Xen guest support on ARM64" 1641 depends on ARM64 && OF 1642 select SWIOTLB_XEN 1643 select PARAVIRT 1644 help 1645 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1646 1647# include/linux/mmzone.h requires the following to be true: 1648# 1649# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1650# 1651# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1652# 1653# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1654# ----+-------------------+--------------+----------------------+-------------------------+ 1655# 4K | 27 | 12 | 15 | 10 | 1656# 16K | 27 | 14 | 13 | 11 | 1657# 64K | 29 | 16 | 13 | 13 | 1658config ARCH_FORCE_MAX_ORDER 1659 int 1660 default "13" if ARM64_64K_PAGES 1661 default "11" if ARM64_16K_PAGES 1662 default "10" 1663 help 1664 The kernel page allocator limits the size of maximal physically 1665 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1666 defines the maximal power of two of number of pages that can be 1667 allocated as a single contiguous block. This option allows 1668 overriding the default setting when ability to allocate very 1669 large blocks of physically contiguous memory is required. 1670 1671 The maximal size of allocation cannot exceed the size of the 1672 section, so the value of MAX_PAGE_ORDER should satisfy 1673 1674 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1675 1676 Don't change if unsure. 1677 1678config UNMAP_KERNEL_AT_EL0 1679 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1680 default y 1681 help 1682 Speculation attacks against some high-performance processors can 1683 be used to bypass MMU permission checks and leak kernel data to 1684 userspace. This can be defended against by unmapping the kernel 1685 when running in userspace, mapping it back in on exception entry 1686 via a trampoline page in the vector table. 1687 1688 If unsure, say Y. 1689 1690config MITIGATE_SPECTRE_BRANCH_HISTORY 1691 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1692 default y 1693 help 1694 Speculation attacks against some high-performance processors can 1695 make use of branch history to influence future speculation. 1696 When taking an exception from user-space, a sequence of branches 1697 or a firmware call overwrites the branch history. 1698 1699config RODATA_FULL_DEFAULT_ENABLED 1700 bool "Apply r/o permissions of VM areas also to their linear aliases" 1701 default y 1702 help 1703 Apply read-only attributes of VM areas to the linear alias of 1704 the backing pages as well. This prevents code or read-only data 1705 from being modified (inadvertently or intentionally) via another 1706 mapping of the same memory page. This additional enhancement can 1707 be turned off at runtime by passing rodata=[off|on] (and turned on 1708 with rodata=full if this option is set to 'n') 1709 1710 This requires the linear region to be mapped down to pages, 1711 which may adversely affect performance in some cases. 1712 1713config ARM64_SW_TTBR0_PAN 1714 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1715 depends on !KCSAN 1716 select ARM64_PAN 1717 help 1718 Enabling this option prevents the kernel from accessing 1719 user-space memory directly by pointing TTBR0_EL1 to a reserved 1720 zeroed area and reserved ASID. The user access routines 1721 restore the valid TTBR0_EL1 temporarily. 1722 1723config ARM64_TAGGED_ADDR_ABI 1724 bool "Enable the tagged user addresses syscall ABI" 1725 default y 1726 help 1727 When this option is enabled, user applications can opt in to a 1728 relaxed ABI via prctl() allowing tagged addresses to be passed 1729 to system calls as pointer arguments. For details, see 1730 Documentation/arch/arm64/tagged-address-abi.rst. 1731 1732menuconfig COMPAT 1733 bool "Kernel support for 32-bit EL0" 1734 depends on ARM64_4K_PAGES || EXPERT 1735 select HAVE_UID16 1736 select OLD_SIGSUSPEND3 1737 select COMPAT_OLD_SIGACTION 1738 help 1739 This option enables support for a 32-bit EL0 running under a 64-bit 1740 kernel at EL1. AArch32-specific components such as system calls, 1741 the user helper functions, VFP support and the ptrace interface are 1742 handled appropriately by the kernel. 1743 1744 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1745 that you will only be able to execute AArch32 binaries that were compiled 1746 with page size aligned segments. 1747 1748 If you want to execute 32-bit userspace applications, say Y. 1749 1750if COMPAT 1751 1752config KUSER_HELPERS 1753 bool "Enable kuser helpers page for 32-bit applications" 1754 default y 1755 help 1756 Warning: disabling this option may break 32-bit user programs. 1757 1758 Provide kuser helpers to compat tasks. The kernel provides 1759 helper code to userspace in read only form at a fixed location 1760 to allow userspace to be independent of the CPU type fitted to 1761 the system. This permits binaries to be run on ARMv4 through 1762 to ARMv8 without modification. 1763 1764 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1765 1766 However, the fixed address nature of these helpers can be used 1767 by ROP (return orientated programming) authors when creating 1768 exploits. 1769 1770 If all of the binaries and libraries which run on your platform 1771 are built specifically for your platform, and make no use of 1772 these helpers, then you can turn this option off to hinder 1773 such exploits. However, in that case, if a binary or library 1774 relying on those helpers is run, it will not function correctly. 1775 1776 Say N here only if you are absolutely certain that you do not 1777 need these helpers; otherwise, the safe option is to say Y. 1778 1779config COMPAT_VDSO 1780 bool "Enable vDSO for 32-bit applications" 1781 depends on !CPU_BIG_ENDIAN 1782 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1783 default y 1784 help 1785 Place in the process address space of 32-bit applications an 1786 ELF shared object providing fast implementations of gettimeofday 1787 and clock_gettime. 1788 1789 You must have a 32-bit build of glibc 2.22 or later for programs 1790 to seamlessly take advantage of this. 1791 1792config THUMB2_COMPAT_VDSO 1793 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1794 depends on COMPAT_VDSO 1795 default y 1796 help 1797 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1798 otherwise with '-marm'. 1799 1800config COMPAT_ALIGNMENT_FIXUPS 1801 bool "Fix up misaligned multi-word loads and stores in user space" 1802 1803menuconfig ARMV8_DEPRECATED 1804 bool "Emulate deprecated/obsolete ARMv8 instructions" 1805 depends on SYSCTL 1806 help 1807 Legacy software support may require certain instructions 1808 that have been deprecated or obsoleted in the architecture. 1809 1810 Enable this config to enable selective emulation of these 1811 features. 1812 1813 If unsure, say Y 1814 1815if ARMV8_DEPRECATED 1816 1817config SWP_EMULATION 1818 bool "Emulate SWP/SWPB instructions" 1819 help 1820 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1821 they are always undefined. Say Y here to enable software 1822 emulation of these instructions for userspace using LDXR/STXR. 1823 This feature can be controlled at runtime with the abi.swp 1824 sysctl which is disabled by default. 1825 1826 In some older versions of glibc [<=2.8] SWP is used during futex 1827 trylock() operations with the assumption that the code will not 1828 be preempted. This invalid assumption may be more likely to fail 1829 with SWP emulation enabled, leading to deadlock of the user 1830 application. 1831 1832 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1833 on an external transaction monitoring block called a global 1834 monitor to maintain update atomicity. If your system does not 1835 implement a global monitor, this option can cause programs that 1836 perform SWP operations to uncached memory to deadlock. 1837 1838 If unsure, say Y 1839 1840config CP15_BARRIER_EMULATION 1841 bool "Emulate CP15 Barrier instructions" 1842 help 1843 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1844 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1845 strongly recommended to use the ISB, DSB, and DMB 1846 instructions instead. 1847 1848 Say Y here to enable software emulation of these 1849 instructions for AArch32 userspace code. When this option is 1850 enabled, CP15 barrier usage is traced which can help 1851 identify software that needs updating. This feature can be 1852 controlled at runtime with the abi.cp15_barrier sysctl. 1853 1854 If unsure, say Y 1855 1856config SETEND_EMULATION 1857 bool "Emulate SETEND instruction" 1858 help 1859 The SETEND instruction alters the data-endianness of the 1860 AArch32 EL0, and is deprecated in ARMv8. 1861 1862 Say Y here to enable software emulation of the instruction 1863 for AArch32 userspace code. This feature can be controlled 1864 at runtime with the abi.setend sysctl. 1865 1866 Note: All the cpus on the system must have mixed endian support at EL0 1867 for this feature to be enabled. If a new CPU - which doesn't support mixed 1868 endian - is hotplugged in after this feature has been enabled, there could 1869 be unexpected results in the applications. 1870 1871 If unsure, say Y 1872endif # ARMV8_DEPRECATED 1873 1874endif # COMPAT 1875 1876menu "ARMv8.1 architectural features" 1877 1878config ARM64_HW_AFDBM 1879 bool "Support for hardware updates of the Access and Dirty page flags" 1880 default y 1881 help 1882 The ARMv8.1 architecture extensions introduce support for 1883 hardware updates of the access and dirty information in page 1884 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1885 capable processors, accesses to pages with PTE_AF cleared will 1886 set this bit instead of raising an access flag fault. 1887 Similarly, writes to read-only pages with the DBM bit set will 1888 clear the read-only bit (AP[2]) instead of raising a 1889 permission fault. 1890 1891 Kernels built with this configuration option enabled continue 1892 to work on pre-ARMv8.1 hardware and the performance impact is 1893 minimal. If unsure, say Y. 1894 1895config ARM64_PAN 1896 bool "Enable support for Privileged Access Never (PAN)" 1897 default y 1898 help 1899 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1900 prevents the kernel or hypervisor from accessing user-space (EL0) 1901 memory directly. 1902 1903 Choosing this option will cause any unprotected (not using 1904 copy_to_user et al) memory access to fail with a permission fault. 1905 1906 The feature is detected at runtime, and will remain as a 'nop' 1907 instruction if the cpu does not implement the feature. 1908 1909config ARM64_LSE_ATOMICS 1910 bool 1911 default ARM64_USE_LSE_ATOMICS 1912 1913config ARM64_USE_LSE_ATOMICS 1914 bool "Atomic instructions" 1915 default y 1916 help 1917 As part of the Large System Extensions, ARMv8.1 introduces new 1918 atomic instructions that are designed specifically to scale in 1919 very large systems. 1920 1921 Say Y here to make use of these instructions for the in-kernel 1922 atomic routines. This incurs a small overhead on CPUs that do 1923 not support these instructions. 1924 1925endmenu # "ARMv8.1 architectural features" 1926 1927menu "ARMv8.2 architectural features" 1928 1929config ARM64_PMEM 1930 bool "Enable support for persistent memory" 1931 select ARCH_HAS_PMEM_API 1932 select ARCH_HAS_UACCESS_FLUSHCACHE 1933 help 1934 Say Y to enable support for the persistent memory API based on the 1935 ARMv8.2 DCPoP feature. 1936 1937 The feature is detected at runtime, and the kernel will use DC CVAC 1938 operations if DC CVAP is not supported (following the behaviour of 1939 DC CVAP itself if the system does not define a point of persistence). 1940 1941config ARM64_RAS_EXTN 1942 bool "Enable support for RAS CPU Extensions" 1943 default y 1944 help 1945 CPUs that support the Reliability, Availability and Serviceability 1946 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1947 errors, classify them and report them to software. 1948 1949 On CPUs with these extensions system software can use additional 1950 barriers to determine if faults are pending and read the 1951 classification from a new set of registers. 1952 1953 Selecting this feature will allow the kernel to use these barriers 1954 and access the new registers if the system supports the extension. 1955 Platform RAS features may additionally depend on firmware support. 1956 1957config ARM64_CNP 1958 bool "Enable support for Common Not Private (CNP) translations" 1959 default y 1960 help 1961 Common Not Private (CNP) allows translation table entries to 1962 be shared between different PEs in the same inner shareable 1963 domain, so the hardware can use this fact to optimise the 1964 caching of such entries in the TLB. 1965 1966 Selecting this option allows the CNP feature to be detected 1967 at runtime, and does not affect PEs that do not implement 1968 this feature. 1969 1970endmenu # "ARMv8.2 architectural features" 1971 1972menu "ARMv8.3 architectural features" 1973 1974config ARM64_PTR_AUTH 1975 bool "Enable support for pointer authentication" 1976 default y 1977 help 1978 Pointer authentication (part of the ARMv8.3 Extensions) provides 1979 instructions for signing and authenticating pointers against secret 1980 keys, which can be used to mitigate Return Oriented Programming (ROP) 1981 and other attacks. 1982 1983 This option enables these instructions at EL0 (i.e. for userspace). 1984 Choosing this option will cause the kernel to initialise secret keys 1985 for each process at exec() time, with these keys being 1986 context-switched along with the process. 1987 1988 The feature is detected at runtime. If the feature is not present in 1989 hardware it will not be advertised to userspace/KVM guest nor will it 1990 be enabled. 1991 1992 If the feature is present on the boot CPU but not on a late CPU, then 1993 the late CPU will be parked. Also, if the boot CPU does not have 1994 address auth and the late CPU has then the late CPU will still boot 1995 but with the feature disabled. On such a system, this option should 1996 not be selected. 1997 1998config ARM64_PTR_AUTH_KERNEL 1999 bool "Use pointer authentication for kernel" 2000 default y 2001 depends on ARM64_PTR_AUTH 2002 # Modern compilers insert a .note.gnu.property section note for PAC 2003 # which is only understood by binutils starting with version 2.33.1. 2004 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2005 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2006 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2007 help 2008 If the compiler supports the -mbranch-protection or 2009 -msign-return-address flag (e.g. GCC 7 or later), then this option 2010 will cause the kernel itself to be compiled with return address 2011 protection. In this case, and if the target hardware is known to 2012 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2013 disabled with minimal loss of protection. 2014 2015 This feature works with FUNCTION_GRAPH_TRACER option only if 2016 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2017 2018config CC_HAS_BRANCH_PROT_PAC_RET 2019 # GCC 9 or later, clang 8 or later 2020 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2021 2022config AS_HAS_CFI_NEGATE_RA_STATE 2023 # binutils 2.34+ 2024 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2025 2026endmenu # "ARMv8.3 architectural features" 2027 2028menu "ARMv8.4 architectural features" 2029 2030config ARM64_AMU_EXTN 2031 bool "Enable support for the Activity Monitors Unit CPU extension" 2032 default y 2033 help 2034 The activity monitors extension is an optional extension introduced 2035 by the ARMv8.4 CPU architecture. This enables support for version 1 2036 of the activity monitors architecture, AMUv1. 2037 2038 To enable the use of this extension on CPUs that implement it, say Y. 2039 2040 Note that for architectural reasons, firmware _must_ implement AMU 2041 support when running on CPUs that present the activity monitors 2042 extension. The required support is present in: 2043 * Version 1.5 and later of the ARM Trusted Firmware 2044 2045 For kernels that have this configuration enabled but boot with broken 2046 firmware, you may need to say N here until the firmware is fixed. 2047 Otherwise you may experience firmware panics or lockups when 2048 accessing the counter registers. Even if you are not observing these 2049 symptoms, the values returned by the register reads might not 2050 correctly reflect reality. Most commonly, the value read will be 0, 2051 indicating that the counter is not enabled. 2052 2053config ARM64_TLB_RANGE 2054 bool "Enable support for tlbi range feature" 2055 default y 2056 help 2057 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2058 range of input addresses. 2059 2060endmenu # "ARMv8.4 architectural features" 2061 2062menu "ARMv8.5 architectural features" 2063 2064config AS_HAS_ARMV8_5 2065 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2066 2067config ARM64_BTI 2068 bool "Branch Target Identification support" 2069 default y 2070 help 2071 Branch Target Identification (part of the ARMv8.5 Extensions) 2072 provides a mechanism to limit the set of locations to which computed 2073 branch instructions such as BR or BLR can jump. 2074 2075 To make use of BTI on CPUs that support it, say Y. 2076 2077 BTI is intended to provide complementary protection to other control 2078 flow integrity protection mechanisms, such as the Pointer 2079 authentication mechanism provided as part of the ARMv8.3 Extensions. 2080 For this reason, it does not make sense to enable this option without 2081 also enabling support for pointer authentication. Thus, when 2082 enabling this option you should also select ARM64_PTR_AUTH=y. 2083 2084 Userspace binaries must also be specifically compiled to make use of 2085 this mechanism. If you say N here or the hardware does not support 2086 BTI, such binaries can still run, but you get no additional 2087 enforcement of branch destinations. 2088 2089config ARM64_BTI_KERNEL 2090 bool "Use Branch Target Identification for kernel" 2091 default y 2092 depends on ARM64_BTI 2093 depends on ARM64_PTR_AUTH_KERNEL 2094 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2095 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2096 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2097 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2098 depends on !CC_IS_GCC 2099 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2100 help 2101 Build the kernel with Branch Target Identification annotations 2102 and enable enforcement of this for kernel code. When this option 2103 is enabled and the system supports BTI all kernel code including 2104 modular code must have BTI enabled. 2105 2106config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2107 # GCC 9 or later, clang 8 or later 2108 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2109 2110config ARM64_E0PD 2111 bool "Enable support for E0PD" 2112 default y 2113 help 2114 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2115 that EL0 accesses made via TTBR1 always fault in constant time, 2116 providing similar benefits to KASLR as those provided by KPTI, but 2117 with lower overhead and without disrupting legitimate access to 2118 kernel memory such as SPE. 2119 2120 This option enables E0PD for TTBR1 where available. 2121 2122config ARM64_AS_HAS_MTE 2123 # Initial support for MTE went in binutils 2.32.0, checked with 2124 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2125 # as a late addition to the final architecture spec (LDGM/STGM) 2126 # is only supported in the newer 2.32.x and 2.33 binutils 2127 # versions, hence the extra "stgm" instruction check below. 2128 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2129 2130config ARM64_MTE 2131 bool "Memory Tagging Extension support" 2132 default y 2133 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2134 depends on AS_HAS_ARMV8_5 2135 # Required for tag checking in the uaccess routines 2136 select ARM64_PAN 2137 select ARCH_HAS_SUBPAGE_FAULTS 2138 select ARCH_USES_HIGH_VMA_FLAGS 2139 select ARCH_USES_PG_ARCH_2 2140 select ARCH_USES_PG_ARCH_3 2141 help 2142 Memory Tagging (part of the ARMv8.5 Extensions) provides 2143 architectural support for run-time, always-on detection of 2144 various classes of memory error to aid with software debugging 2145 to eliminate vulnerabilities arising from memory-unsafe 2146 languages. 2147 2148 This option enables the support for the Memory Tagging 2149 Extension at EL0 (i.e. for userspace). 2150 2151 Selecting this option allows the feature to be detected at 2152 runtime. Any secondary CPU not implementing this feature will 2153 not be allowed a late bring-up. 2154 2155 Userspace binaries that want to use this feature must 2156 explicitly opt in. The mechanism for the userspace is 2157 described in: 2158 2159 Documentation/arch/arm64/memory-tagging-extension.rst. 2160 2161endmenu # "ARMv8.5 architectural features" 2162 2163menu "ARMv8.7 architectural features" 2164 2165config ARM64_EPAN 2166 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2167 default y 2168 depends on ARM64_PAN 2169 help 2170 Enhanced Privileged Access Never (EPAN) allows Privileged 2171 Access Never to be used with Execute-only mappings. 2172 2173 The feature is detected at runtime, and will remain disabled 2174 if the cpu does not implement the feature. 2175endmenu # "ARMv8.7 architectural features" 2176 2177config AS_HAS_MOPS 2178 def_bool $(as-instr,.arch_extension mops) 2179 2180menu "ARMv8.9 architectural features" 2181 2182config ARM64_POE 2183 prompt "Permission Overlay Extension" 2184 def_bool y 2185 select ARCH_USES_HIGH_VMA_FLAGS 2186 select ARCH_HAS_PKEYS 2187 help 2188 The Permission Overlay Extension is used to implement Memory 2189 Protection Keys. Memory Protection Keys provides a mechanism for 2190 enforcing page-based protections, but without requiring modification 2191 of the page tables when an application changes protection domains. 2192 2193 For details, see Documentation/core-api/protection-keys.rst 2194 2195 If unsure, say y. 2196 2197config ARCH_PKEY_BITS 2198 int 2199 default 3 2200 2201config ARM64_HAFT 2202 bool "Support for Hardware managed Access Flag for Table Descriptors" 2203 depends on ARM64_HW_AFDBM 2204 default y 2205 help 2206 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2207 Flag for Table descriptors. When enabled an architectural executed 2208 memory access will update the Access Flag in each Table descriptor 2209 which is accessed during the translation table walk and for which 2210 the Access Flag is 0. The Access Flag of the Table descriptor use 2211 the same bit of PTE_AF. 2212 2213 The feature will only be enabled if all the CPUs in the system 2214 support this feature. If unsure, say Y. 2215 2216endmenu # "ARMv8.9 architectural features" 2217 2218menu "v9.4 architectural features" 2219 2220config ARM64_GCS 2221 bool "Enable support for Guarded Control Stack (GCS)" 2222 default y 2223 select ARCH_HAS_USER_SHADOW_STACK 2224 select ARCH_USES_HIGH_VMA_FLAGS 2225 depends on !UPROBES 2226 help 2227 Guarded Control Stack (GCS) provides support for a separate 2228 stack with restricted access which contains only return 2229 addresses. This can be used to harden against some attacks 2230 by comparing return address used by the program with what is 2231 stored in the GCS, and may also be used to efficiently obtain 2232 the call stack for applications such as profiling. 2233 2234 The feature is detected at runtime, and will remain disabled 2235 if the system does not implement the feature. 2236 2237endmenu # "v9.4 architectural features" 2238 2239config ARM64_SVE 2240 bool "ARM Scalable Vector Extension support" 2241 default y 2242 help 2243 The Scalable Vector Extension (SVE) is an extension to the AArch64 2244 execution state which complements and extends the SIMD functionality 2245 of the base architecture to support much larger vectors and to enable 2246 additional vectorisation opportunities. 2247 2248 To enable use of this extension on CPUs that implement it, say Y. 2249 2250 On CPUs that support the SVE2 extensions, this option will enable 2251 those too. 2252 2253 Note that for architectural reasons, firmware _must_ implement SVE 2254 support when running on SVE capable hardware. The required support 2255 is present in: 2256 2257 * version 1.5 and later of the ARM Trusted Firmware 2258 * the AArch64 boot wrapper since commit 5e1261e08abf 2259 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2260 2261 For other firmware implementations, consult the firmware documentation 2262 or vendor. 2263 2264 If you need the kernel to boot on SVE-capable hardware with broken 2265 firmware, you may need to say N here until you get your firmware 2266 fixed. Otherwise, you may experience firmware panics or lockups when 2267 booting the kernel. If unsure and you are not observing these 2268 symptoms, you should assume that it is safe to say Y. 2269 2270config ARM64_SME 2271 bool "ARM Scalable Matrix Extension support" 2272 default y 2273 depends on ARM64_SVE 2274 help 2275 The Scalable Matrix Extension (SME) is an extension to the AArch64 2276 execution state which utilises a substantial subset of the SVE 2277 instruction set, together with the addition of new architectural 2278 register state capable of holding two dimensional matrix tiles to 2279 enable various matrix operations. 2280 2281config ARM64_PSEUDO_NMI 2282 bool "Support for NMI-like interrupts" 2283 select ARM_GIC_V3 2284 help 2285 Adds support for mimicking Non-Maskable Interrupts through the use of 2286 GIC interrupt priority. This support requires version 3 or later of 2287 ARM GIC. 2288 2289 This high priority configuration for interrupts needs to be 2290 explicitly enabled by setting the kernel parameter 2291 "irqchip.gicv3_pseudo_nmi" to 1. 2292 2293 If unsure, say N 2294 2295if ARM64_PSEUDO_NMI 2296config ARM64_DEBUG_PRIORITY_MASKING 2297 bool "Debug interrupt priority masking" 2298 help 2299 This adds runtime checks to functions enabling/disabling 2300 interrupts when using priority masking. The additional checks verify 2301 the validity of ICC_PMR_EL1 when calling concerned functions. 2302 2303 If unsure, say N 2304endif # ARM64_PSEUDO_NMI 2305 2306config RELOCATABLE 2307 bool "Build a relocatable kernel image" if EXPERT 2308 select ARCH_HAS_RELR 2309 default y 2310 help 2311 This builds the kernel as a Position Independent Executable (PIE), 2312 which retains all relocation metadata required to relocate the 2313 kernel binary at runtime to a different virtual address than the 2314 address it was linked at. 2315 Since AArch64 uses the RELA relocation format, this requires a 2316 relocation pass at runtime even if the kernel is loaded at the 2317 same address it was linked at. 2318 2319config RANDOMIZE_BASE 2320 bool "Randomize the address of the kernel image" 2321 select RELOCATABLE 2322 help 2323 Randomizes the virtual address at which the kernel image is 2324 loaded, as a security feature that deters exploit attempts 2325 relying on knowledge of the location of kernel internals. 2326 2327 It is the bootloader's job to provide entropy, by passing a 2328 random u64 value in /chosen/kaslr-seed at kernel entry. 2329 2330 When booting via the UEFI stub, it will invoke the firmware's 2331 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2332 to the kernel proper. In addition, it will randomise the physical 2333 location of the kernel Image as well. 2334 2335 If unsure, say N. 2336 2337config RANDOMIZE_MODULE_REGION_FULL 2338 bool "Randomize the module region over a 2 GB range" 2339 depends on RANDOMIZE_BASE 2340 default y 2341 help 2342 Randomizes the location of the module region inside a 2 GB window 2343 covering the core kernel. This way, it is less likely for modules 2344 to leak information about the location of core kernel data structures 2345 but it does imply that function calls between modules and the core 2346 kernel will need to be resolved via veneers in the module PLT. 2347 2348 When this option is not set, the module region will be randomized over 2349 a limited range that contains the [_stext, _etext] interval of the 2350 core kernel, so branch relocations are almost always in range unless 2351 the region is exhausted. In this particular case of region 2352 exhaustion, modules might be able to fall back to a larger 2GB area. 2353 2354config CC_HAVE_STACKPROTECTOR_SYSREG 2355 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2356 2357config STACKPROTECTOR_PER_TASK 2358 def_bool y 2359 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2360 2361config UNWIND_PATCH_PAC_INTO_SCS 2362 bool "Enable shadow call stack dynamically using code patching" 2363 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2364 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2365 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2366 depends on SHADOW_CALL_STACK 2367 select UNWIND_TABLES 2368 select DYNAMIC_SCS 2369 2370config ARM64_CONTPTE 2371 bool "Contiguous PTE mappings for user memory" if EXPERT 2372 depends on TRANSPARENT_HUGEPAGE 2373 default y 2374 help 2375 When enabled, user mappings are configured using the PTE contiguous 2376 bit, for any mappings that meet the size and alignment requirements. 2377 This reduces TLB pressure and improves performance. 2378 2379endmenu # "Kernel Features" 2380 2381menu "Boot options" 2382 2383config ARM64_ACPI_PARKING_PROTOCOL 2384 bool "Enable support for the ARM64 ACPI parking protocol" 2385 depends on ACPI 2386 help 2387 Enable support for the ARM64 ACPI parking protocol. If disabled 2388 the kernel will not allow booting through the ARM64 ACPI parking 2389 protocol even if the corresponding data is present in the ACPI 2390 MADT table. 2391 2392config CMDLINE 2393 string "Default kernel command string" 2394 default "" 2395 help 2396 Provide a set of default command-line options at build time by 2397 entering them here. As a minimum, you should specify the the 2398 root device (e.g. root=/dev/nfs). 2399 2400choice 2401 prompt "Kernel command line type" 2402 depends on CMDLINE != "" 2403 default CMDLINE_FROM_BOOTLOADER 2404 help 2405 Choose how the kernel will handle the provided default kernel 2406 command line string. 2407 2408config CMDLINE_FROM_BOOTLOADER 2409 bool "Use bootloader kernel arguments if available" 2410 help 2411 Uses the command-line options passed by the boot loader. If 2412 the boot loader doesn't provide any, the default kernel command 2413 string provided in CMDLINE will be used. 2414 2415config CMDLINE_FORCE 2416 bool "Always use the default kernel command string" 2417 help 2418 Always use the default kernel command string, even if the boot 2419 loader passes other arguments to the kernel. 2420 This is useful if you cannot or don't want to change the 2421 command-line options your boot loader passes to the kernel. 2422 2423endchoice 2424 2425config EFI_STUB 2426 bool 2427 2428config EFI 2429 bool "UEFI runtime support" 2430 depends on OF && !CPU_BIG_ENDIAN 2431 depends on KERNEL_MODE_NEON 2432 select ARCH_SUPPORTS_ACPI 2433 select LIBFDT 2434 select UCS2_STRING 2435 select EFI_PARAMS_FROM_FDT 2436 select EFI_RUNTIME_WRAPPERS 2437 select EFI_STUB 2438 select EFI_GENERIC_STUB 2439 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2440 default y 2441 help 2442 This option provides support for runtime services provided 2443 by UEFI firmware (such as non-volatile variables, realtime 2444 clock, and platform reset). A UEFI stub is also provided to 2445 allow the kernel to be booted as an EFI application. This 2446 is only useful on systems that have UEFI firmware. 2447 2448config COMPRESSED_INSTALL 2449 bool "Install compressed image by default" 2450 help 2451 This makes the regular "make install" install the compressed 2452 image we built, not the legacy uncompressed one. 2453 2454 You can check that a compressed image works for you by doing 2455 "make zinstall" first, and verifying that everything is fine 2456 in your environment before making "make install" do this for 2457 you. 2458 2459config DMI 2460 bool "Enable support for SMBIOS (DMI) tables" 2461 depends on EFI 2462 default y 2463 help 2464 This enables SMBIOS/DMI feature for systems. 2465 2466 This option is only useful on systems that have UEFI firmware. 2467 However, even with this option, the resultant kernel should 2468 continue to boot on existing non-UEFI platforms. 2469 2470endmenu # "Boot options" 2471 2472menu "Power management options" 2473 2474source "kernel/power/Kconfig" 2475 2476config ARCH_HIBERNATION_POSSIBLE 2477 def_bool y 2478 depends on CPU_PM 2479 2480config ARCH_HIBERNATION_HEADER 2481 def_bool y 2482 depends on HIBERNATION 2483 2484config ARCH_SUSPEND_POSSIBLE 2485 def_bool y 2486 2487endmenu # "Power management options" 2488 2489menu "CPU Power Management" 2490 2491source "drivers/cpuidle/Kconfig" 2492 2493source "drivers/cpufreq/Kconfig" 2494 2495endmenu # "CPU Power Management" 2496 2497source "drivers/acpi/Kconfig" 2498 2499source "arch/arm64/kvm/Kconfig" 2500 2501source "kernel/livepatch/Kconfig" 2502