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_CPU_CACHE_INVALIDATE_MEMREGION 25 select ARCH_HAS_CURRENT_STACK_POINTER 26 select ARCH_HAS_DEBUG_VIRTUAL 27 select ARCH_HAS_DEBUG_VM_PGTABLE 28 select ARCH_HAS_DMA_OPS if XEN 29 select ARCH_HAS_DMA_PREP_COHERENT 30 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_KCOV 36 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 37 select ARCH_HAS_KEEPINITRD 38 select ARCH_HAS_MEMBARRIER_SYNC_CORE 39 select ARCH_HAS_MEM_ENCRYPT 40 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 41 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 42 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 43 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 44 select ARCH_HAS_PREEMPT_LAZY 45 select ARCH_HAS_PTDUMP 46 select ARCH_HAS_PTE_SPECIAL 47 select ARCH_HAS_HW_PTE_YOUNG 48 select ARCH_HAS_SETUP_DMA_OPS 49 select ARCH_HAS_SET_DIRECT_MAP 50 select ARCH_HAS_SET_MEMORY 51 select ARCH_HAS_MEM_ENCRYPT 52 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 53 select ARCH_STACKWALK 54 select ARCH_HAS_STRICT_KERNEL_RWX 55 select ARCH_HAS_STRICT_MODULE_RWX 56 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 57 select ARCH_HAS_SYNC_DMA_FOR_CPU 58 select ARCH_HAS_SYSCALL_WRAPPER 59 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 60 select ARCH_HAS_ZONE_DMA_SET if EXPERT 61 select ARCH_HAVE_ELF_PROT 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_HAVE_TRACE_MMIO_ACCESS 64 select ARCH_INLINE_READ_LOCK if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 67 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 71 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 81 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 85 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 89 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 90 select ARCH_KEEP_MEMBLOCK 91 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 92 select ARCH_USE_CMPXCHG_LOCKREF 93 select ARCH_USE_GNU_PROPERTY 94 select ARCH_USE_MEMTEST 95 select ARCH_USE_QUEUED_RWLOCKS 96 select ARCH_USE_QUEUED_SPINLOCKS 97 select ARCH_USE_SYM_ANNOTATIONS 98 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 99 select ARCH_SUPPORTS_HUGETLBFS 100 select ARCH_SUPPORTS_MEMORY_FAILURE 101 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 102 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 103 select ARCH_SUPPORTS_LTO_CLANG_THIN 104 select ARCH_SUPPORTS_CFI_CLANG 105 select ARCH_SUPPORTS_ATOMIC_RMW 106 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 107 select ARCH_SUPPORTS_NUMA_BALANCING 108 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 109 select ARCH_SUPPORTS_PER_VMA_LOCK 110 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 111 select ARCH_SUPPORTS_RT 112 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 113 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 114 select ARCH_WANT_DEFAULT_BPF_JIT 115 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 116 select ARCH_WANT_FRAME_POINTERS 117 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 118 select ARCH_WANT_LD_ORPHAN_WARN 119 select ARCH_WANTS_EXECMEM_LATE 120 select ARCH_WANTS_NO_INSTR 121 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 122 select ARCH_HAS_UBSAN 123 select ARM_AMBA 124 select ARM_ARCH_TIMER 125 select ARM_GIC 126 select AUDIT_ARCH_COMPAT_GENERIC 127 select ARM_GIC_V2M if PCI 128 select ARM_GIC_V3 129 select ARM_GIC_V3_ITS if PCI 130 select ARM_GIC_V5 131 select ARM_PSCI_FW 132 select BUILDTIME_TABLE_SORT 133 select CLONE_BACKWARDS 134 select COMMON_CLK 135 select CPU_PM if (SUSPEND || CPU_IDLE) 136 select CPUMASK_OFFSTACK if NR_CPUS > 256 137 select DCACHE_WORD_ACCESS 138 select HAVE_EXTRA_IPI_TRACEPOINTS 139 select DYNAMIC_FTRACE if FUNCTION_TRACER 140 select DMA_BOUNCE_UNALIGNED_KMALLOC 141 select DMA_DIRECT_REMAP 142 select EDAC_SUPPORT 143 select FRAME_POINTER 144 select FUNCTION_ALIGNMENT_4B 145 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 146 select GENERIC_ALLOCATOR 147 select GENERIC_ARCH_TOPOLOGY 148 select GENERIC_CLOCKEVENTS_BROADCAST 149 select GENERIC_CPU_AUTOPROBE 150 select GENERIC_CPU_CACHE_MAINTENANCE 151 select GENERIC_CPU_DEVICES 152 select GENERIC_CPU_VULNERABILITIES 153 select GENERIC_EARLY_IOREMAP 154 select GENERIC_IDLE_POLL_SETUP 155 select GENERIC_IOREMAP 156 select GENERIC_IRQ_IPI 157 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 158 select GENERIC_IRQ_PROBE 159 select GENERIC_IRQ_SHOW 160 select GENERIC_IRQ_SHOW_LEVEL 161 select GENERIC_LIB_DEVMEM_IS_ALLOWED 162 select GENERIC_PCI_IOMAP 163 select GENERIC_SCHED_CLOCK 164 select GENERIC_SMP_IDLE_THREAD 165 select GENERIC_TIME_VSYSCALL 166 select GENERIC_GETTIMEOFDAY 167 select GENERIC_VDSO_DATA_STORE 168 select GENERIC_VDSO_TIME_NS 169 select HARDIRQS_SW_RESEND 170 select HAS_IOPORT 171 select HAVE_MOVE_PMD 172 select HAVE_MOVE_PUD 173 select HAVE_PCI 174 select HAVE_ACPI_APEI if (ACPI && EFI) 175 select HAVE_ALIGNED_STRUCT_PAGE 176 select HAVE_ARCH_AUDITSYSCALL 177 select HAVE_ARCH_BITREVERSE 178 select HAVE_ARCH_COMPILER_H 179 select HAVE_ARCH_HUGE_VMALLOC 180 select HAVE_ARCH_HUGE_VMAP 181 select HAVE_ARCH_JUMP_LABEL 182 select HAVE_ARCH_JUMP_LABEL_RELATIVE 183 select HAVE_ARCH_KASAN 184 select HAVE_ARCH_KASAN_VMALLOC 185 select HAVE_ARCH_KASAN_SW_TAGS 186 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 187 # Some instrumentation may be unsound, hence EXPERT 188 select HAVE_ARCH_KCSAN if EXPERT 189 select HAVE_ARCH_KFENCE 190 select HAVE_ARCH_KGDB 191 select HAVE_ARCH_KSTACK_ERASE 192 select HAVE_ARCH_MMAP_RND_BITS 193 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 194 select HAVE_ARCH_PREL32_RELOCATIONS 195 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 196 select HAVE_ARCH_SECCOMP_FILTER 197 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 198 select HAVE_ARCH_TRACEHOOK 199 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 200 select HAVE_ARCH_VMAP_STACK 201 select HAVE_ARM_SMCCC 202 select HAVE_ASM_MODVERSIONS 203 select HAVE_EBPF_JIT 204 select HAVE_C_RECORDMCOUNT 205 select HAVE_CMPXCHG_DOUBLE 206 select HAVE_CMPXCHG_LOCAL 207 select HAVE_CONTEXT_TRACKING_USER 208 select HAVE_DEBUG_KMEMLEAK 209 select HAVE_DMA_CONTIGUOUS 210 select HAVE_DYNAMIC_FTRACE 211 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 212 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 213 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 214 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 215 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 216 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 217 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 218 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 219 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 220 if DYNAMIC_FTRACE_WITH_ARGS 221 select HAVE_SAMPLE_FTRACE_DIRECT 222 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 223 select HAVE_BUILDTIME_MCOUNT_SORT 224 select HAVE_EFFICIENT_UNALIGNED_ACCESS 225 select HAVE_GUP_FAST 226 select HAVE_FTRACE_GRAPH_FUNC 227 select HAVE_FUNCTION_TRACER 228 select HAVE_FUNCTION_ERROR_INJECTION 229 select HAVE_FUNCTION_GRAPH_FREGS 230 select HAVE_FUNCTION_GRAPH_TRACER 231 select HAVE_GCC_PLUGINS 232 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 233 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 234 select HAVE_HW_BREAKPOINT if PERF_EVENTS 235 select HAVE_IOREMAP_PROT 236 select HAVE_IRQ_TIME_ACCOUNTING 237 select HAVE_LIVEPATCH 238 select HAVE_MOD_ARCH_SPECIFIC 239 select HAVE_NMI 240 select HAVE_PERF_EVENTS 241 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 242 select HAVE_PERF_REGS 243 select HAVE_PERF_USER_STACK_DUMP 244 select HAVE_PREEMPT_DYNAMIC_KEY 245 select HAVE_REGS_AND_STACK_ACCESS_API 246 select HAVE_RELIABLE_STACKTRACE 247 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 248 select HAVE_FUNCTION_ARG_ACCESS_API 249 select MMU_GATHER_RCU_TABLE_FREE 250 select HAVE_RSEQ 251 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 252 select HAVE_STACKPROTECTOR 253 select HAVE_SYSCALL_TRACEPOINTS 254 select HAVE_KPROBES 255 select HAVE_KRETPROBES 256 select HAVE_GENERIC_VDSO 257 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 258 select HOTPLUG_SMT if HOTPLUG_CPU 259 select IRQ_DOMAIN 260 select IRQ_FORCED_THREADING 261 select JUMP_LABEL 262 select KASAN_VMALLOC if KASAN 263 select LOCK_MM_AND_FIND_VMA 264 select MODULES_USE_ELF_RELA 265 select NEED_DMA_MAP_STATE 266 select NEED_SG_DMA_LENGTH 267 select OF 268 select OF_EARLY_FLATTREE 269 select PCI_DOMAINS_GENERIC if PCI 270 select PCI_ECAM if (ACPI && PCI) 271 select PCI_SYSCALL if PCI 272 select POWER_RESET 273 select POWER_SUPPLY 274 select SPARSE_IRQ 275 select SWIOTLB 276 select SYSCTL_EXCEPTION_TRACE 277 select THREAD_INFO_IN_TASK 278 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 279 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 280 select TRACE_IRQFLAGS_SUPPORT 281 select TRACE_IRQFLAGS_NMI_SUPPORT 282 select HAVE_SOFTIRQ_ON_OWN_STACK 283 select USER_STACKTRACE_SUPPORT 284 select VDSO_GETRANDOM 285 select VMAP_STACK 286 help 287 ARM 64-bit (AArch64) Linux support. 288 289config RUSTC_SUPPORTS_ARM64 290 def_bool y 291 depends on CPU_LITTLE_ENDIAN 292 # Shadow call stack is only supported on certain rustc versions. 293 # 294 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 295 # required due to use of the -Zfixed-x18 flag. 296 # 297 # Otherwise, rustc version 1.82+ is required due to use of the 298 # -Zsanitizer=shadow-call-stack flag. 299 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 300 301config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 302 def_bool CC_IS_CLANG 303 # https://github.com/ClangBuiltLinux/linux/issues/1507 304 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 305 306config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 307 def_bool CC_IS_GCC 308 depends on $(cc-option,-fpatchable-function-entry=2) 309 310config 64BIT 311 def_bool y 312 313config MMU 314 def_bool y 315 316config ARM64_CONT_PTE_SHIFT 317 int 318 default 5 if PAGE_SIZE_64KB 319 default 7 if PAGE_SIZE_16KB 320 default 4 321 322config ARM64_CONT_PMD_SHIFT 323 int 324 default 5 if PAGE_SIZE_64KB 325 default 5 if PAGE_SIZE_16KB 326 default 4 327 328config ARCH_MMAP_RND_BITS_MIN 329 default 14 if PAGE_SIZE_64KB 330 default 16 if PAGE_SIZE_16KB 331 default 18 332 333# max bits determined by the following formula: 334# VA_BITS - PTDESC_TABLE_SHIFT 335config ARCH_MMAP_RND_BITS_MAX 336 default 19 if ARM64_VA_BITS=36 337 default 24 if ARM64_VA_BITS=39 338 default 27 if ARM64_VA_BITS=42 339 default 30 if ARM64_VA_BITS=47 340 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 341 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 342 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 343 default 14 if ARM64_64K_PAGES 344 default 16 if ARM64_16K_PAGES 345 default 18 346 347config ARCH_MMAP_RND_COMPAT_BITS_MIN 348 default 7 if ARM64_64K_PAGES 349 default 9 if ARM64_16K_PAGES 350 default 11 351 352config ARCH_MMAP_RND_COMPAT_BITS_MAX 353 default 16 354 355config NO_IOPORT_MAP 356 def_bool y if !PCI 357 358config STACKTRACE_SUPPORT 359 def_bool y 360 361config ILLEGAL_POINTER_VALUE 362 hex 363 default 0xdead000000000000 364 365config LOCKDEP_SUPPORT 366 def_bool y 367 368config GENERIC_BUG 369 def_bool y 370 depends on BUG 371 372config GENERIC_BUG_RELATIVE_POINTERS 373 def_bool y 374 depends on GENERIC_BUG 375 376config GENERIC_HWEIGHT 377 def_bool y 378 379config GENERIC_CSUM 380 def_bool y 381 382config GENERIC_CALIBRATE_DELAY 383 def_bool y 384 385config SMP 386 def_bool y 387 388config KERNEL_MODE_NEON 389 def_bool y 390 391config FIX_EARLYCON_MEM 392 def_bool y 393 394config PGTABLE_LEVELS 395 int 396 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 397 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 398 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 399 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 400 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 401 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 402 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 403 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 404 405config ARCH_SUPPORTS_UPROBES 406 def_bool y 407 408config ARCH_PROC_KCORE_TEXT 409 def_bool y 410 411config BROKEN_GAS_INST 412 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 413 414config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 415 bool 416 # Clang's __builtin_return_address() strips the PAC since 12.0.0 417 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 418 default y if CC_IS_CLANG 419 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 420 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 421 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 422 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 423 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 424 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 425 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 426 default n 427 428config KASAN_SHADOW_OFFSET 429 hex 430 depends on KASAN_GENERIC || KASAN_SW_TAGS 431 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 432 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 433 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 434 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 435 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 436 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 437 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 438 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 439 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 440 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 441 default 0xffffffffffffffff 442 443config UNWIND_TABLES 444 bool 445 446source "arch/arm64/Kconfig.platforms" 447 448menu "Kernel Features" 449 450menu "ARM errata workarounds via the alternatives framework" 451 452config AMPERE_ERRATUM_AC03_CPU_38 453 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 454 default y 455 help 456 This option adds an alternative code sequence to work around Ampere 457 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 458 459 The affected design reports FEAT_HAFDBS as not implemented in 460 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 461 as required by the architecture. The unadvertised HAFDBS 462 implementation suffers from an additional erratum where hardware 463 A/D updates can occur after a PTE has been marked invalid. 464 465 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 466 which avoids enabling unadvertised hardware Access Flag management 467 at stage-2. 468 469 If unsure, say Y. 470 471config AMPERE_ERRATUM_AC04_CPU_23 472 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 473 default y 474 help 475 This option adds an alternative code sequence to work around Ampere 476 errata AC04_CPU_23 on AmpereOne. 477 478 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 479 data addresses initiated by load/store instructions. Only 480 instruction initiated translations are vulnerable, not translations 481 from prefetches for example. A DSB before the store to HCR_EL2 is 482 sufficient to prevent older instructions from hitting the window 483 for corruption, and an ISB after is sufficient to prevent younger 484 instructions from hitting the window for corruption. 485 486 If unsure, say Y. 487 488config ARM64_WORKAROUND_CLEAN_CACHE 489 bool 490 491config ARM64_ERRATUM_826319 492 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 493 default y 494 select ARM64_WORKAROUND_CLEAN_CACHE 495 help 496 This option adds an alternative code sequence to work around ARM 497 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 498 AXI master interface and an L2 cache. 499 500 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 501 and is unable to accept a certain write via this interface, it will 502 not progress on read data presented on the read data channel and the 503 system can deadlock. 504 505 The workaround promotes data cache clean instructions to 506 data cache clean-and-invalidate. 507 Please note that this does not necessarily enable the workaround, 508 as it depends on the alternative framework, which will only patch 509 the kernel if an affected CPU is detected. 510 511 If unsure, say Y. 512 513config ARM64_ERRATUM_827319 514 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 515 default y 516 select ARM64_WORKAROUND_CLEAN_CACHE 517 help 518 This option adds an alternative code sequence to work around ARM 519 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 520 master interface and an L2 cache. 521 522 Under certain conditions this erratum can cause a clean line eviction 523 to occur at the same time as another transaction to the same address 524 on the AMBA 5 CHI interface, which can cause data corruption if the 525 interconnect reorders the two transactions. 526 527 The workaround promotes data cache clean instructions to 528 data cache clean-and-invalidate. 529 Please note that this does not necessarily enable the workaround, 530 as it depends on the alternative framework, which will only patch 531 the kernel if an affected CPU is detected. 532 533 If unsure, say Y. 534 535config ARM64_ERRATUM_824069 536 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 537 default y 538 select ARM64_WORKAROUND_CLEAN_CACHE 539 help 540 This option adds an alternative code sequence to work around ARM 541 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 542 to a coherent interconnect. 543 544 If a Cortex-A53 processor is executing a store or prefetch for 545 write instruction at the same time as a processor in another 546 cluster is executing a cache maintenance operation to the same 547 address, then this erratum might cause a clean cache line to be 548 incorrectly marked as dirty. 549 550 The workaround promotes data cache clean instructions to 551 data cache clean-and-invalidate. 552 Please note that this option does not necessarily enable the 553 workaround, as it depends on the alternative framework, which will 554 only patch the kernel if an affected CPU is detected. 555 556 If unsure, say Y. 557 558config ARM64_ERRATUM_819472 559 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 560 default y 561 select ARM64_WORKAROUND_CLEAN_CACHE 562 help 563 This option adds an alternative code sequence to work around ARM 564 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 565 present when it is connected to a coherent interconnect. 566 567 If the processor is executing a load and store exclusive sequence at 568 the same time as a processor in another cluster is executing a cache 569 maintenance operation to the same address, then this erratum might 570 cause data corruption. 571 572 The workaround promotes data cache clean instructions to 573 data cache clean-and-invalidate. 574 Please note that this does not necessarily enable the workaround, 575 as it depends on the alternative framework, which will only patch 576 the kernel if an affected CPU is detected. 577 578 If unsure, say Y. 579 580config ARM64_ERRATUM_832075 581 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 582 default y 583 help 584 This option adds an alternative code sequence to work around ARM 585 erratum 832075 on Cortex-A57 parts up to r1p2. 586 587 Affected Cortex-A57 parts might deadlock when exclusive load/store 588 instructions to Write-Back memory are mixed with Device loads. 589 590 The workaround is to promote device loads to use Load-Acquire 591 semantics. 592 Please note that this does not necessarily enable the workaround, 593 as it depends on the alternative framework, which will only patch 594 the kernel if an affected CPU is detected. 595 596 If unsure, say Y. 597 598config ARM64_ERRATUM_834220 599 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 600 depends on KVM 601 help 602 This option adds an alternative code sequence to work around ARM 603 erratum 834220 on Cortex-A57 parts up to r1p2. 604 605 Affected Cortex-A57 parts might report a Stage 2 translation 606 fault as the result of a Stage 1 fault for load crossing a 607 page boundary when there is a permission or device memory 608 alignment fault at Stage 1 and a translation fault at Stage 2. 609 610 The workaround is to verify that the Stage 1 translation 611 doesn't generate a fault before handling the Stage 2 fault. 612 Please note that this does not necessarily enable the workaround, 613 as it depends on the alternative framework, which will only patch 614 the kernel if an affected CPU is detected. 615 616 If unsure, say N. 617 618config ARM64_ERRATUM_1742098 619 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 620 depends on COMPAT 621 default y 622 help 623 This option removes the AES hwcap for aarch32 user-space to 624 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 625 626 Affected parts may corrupt the AES state if an interrupt is 627 taken between a pair of AES instructions. These instructions 628 are only present if the cryptography extensions are present. 629 All software should have a fallback implementation for CPUs 630 that don't implement the cryptography extensions. 631 632 If unsure, say Y. 633 634config ARM64_ERRATUM_845719 635 bool "Cortex-A53: 845719: a load might read incorrect data" 636 depends on COMPAT 637 default y 638 help 639 This option adds an alternative code sequence to work around ARM 640 erratum 845719 on Cortex-A53 parts up to r0p4. 641 642 When running a compat (AArch32) userspace on an affected Cortex-A53 643 part, a load at EL0 from a virtual address that matches the bottom 32 644 bits of the virtual address used by a recent load at (AArch64) EL1 645 might return incorrect data. 646 647 The workaround is to write the contextidr_el1 register on exception 648 return to a 32-bit task. 649 Please note that this does not necessarily enable the workaround, 650 as it depends on the alternative framework, which will only patch 651 the kernel if an affected CPU is detected. 652 653 If unsure, say Y. 654 655config ARM64_ERRATUM_843419 656 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 657 default y 658 help 659 This option links the kernel with '--fix-cortex-a53-843419' and 660 enables PLT support to replace certain ADRP instructions, which can 661 cause subsequent memory accesses to use an incorrect address on 662 Cortex-A53 parts up to r0p4. 663 664 If unsure, say Y. 665 666config ARM64_ERRATUM_1024718 667 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 668 default y 669 help 670 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 671 672 Affected Cortex-A55 cores (all revisions) could cause incorrect 673 update of the hardware dirty bit when the DBM/AP bits are updated 674 without a break-before-make. The workaround is to disable the usage 675 of hardware DBM locally on the affected cores. CPUs not affected by 676 this erratum will continue to use the feature. 677 678 If unsure, say Y. 679 680config ARM64_ERRATUM_1418040 681 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 682 default y 683 depends on COMPAT 684 help 685 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 686 errata 1188873 and 1418040. 687 688 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 689 cause register corruption when accessing the timer registers 690 from AArch32 userspace. 691 692 If unsure, say Y. 693 694config ARM64_WORKAROUND_SPECULATIVE_AT 695 bool 696 697config ARM64_ERRATUM_1165522 698 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 699 default y 700 select ARM64_WORKAROUND_SPECULATIVE_AT 701 help 702 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 703 704 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 705 corrupted TLBs by speculating an AT instruction during a guest 706 context switch. 707 708 If unsure, say Y. 709 710config ARM64_ERRATUM_1319367 711 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 712 default y 713 select ARM64_WORKAROUND_SPECULATIVE_AT 714 help 715 This option adds work arounds for ARM Cortex-A57 erratum 1319537 716 and A72 erratum 1319367 717 718 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 719 speculating an AT instruction during a guest context switch. 720 721 If unsure, say Y. 722 723config ARM64_ERRATUM_1530923 724 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 725 default y 726 select ARM64_WORKAROUND_SPECULATIVE_AT 727 help 728 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 729 730 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 731 corrupted TLBs by speculating an AT instruction during a guest 732 context switch. 733 734 If unsure, say Y. 735 736config ARM64_WORKAROUND_REPEAT_TLBI 737 bool 738 739config ARM64_ERRATUM_2441007 740 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 741 select ARM64_WORKAROUND_REPEAT_TLBI 742 help 743 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 744 745 Under very rare circumstances, affected Cortex-A55 CPUs 746 may not handle a race between a break-before-make sequence on one 747 CPU, and another CPU accessing the same page. This could allow a 748 store to a page that has been unmapped. 749 750 Work around this by adding the affected CPUs to the list that needs 751 TLB sequences to be done twice. 752 753 If unsure, say N. 754 755config ARM64_ERRATUM_1286807 756 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 757 select ARM64_WORKAROUND_REPEAT_TLBI 758 help 759 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 760 761 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 762 address for a cacheable mapping of a location is being 763 accessed by a core while another core is remapping the virtual 764 address to a new physical page using the recommended 765 break-before-make sequence, then under very rare circumstances 766 TLBI+DSB completes before a read using the translation being 767 invalidated has been observed by other observers. The 768 workaround repeats the TLBI+DSB operation. 769 770 If unsure, say N. 771 772config ARM64_ERRATUM_1463225 773 bool "Cortex-A76: Software Step might prevent interrupt recognition" 774 default y 775 help 776 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 777 778 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 779 of a system call instruction (SVC) can prevent recognition of 780 subsequent interrupts when software stepping is disabled in the 781 exception handler of the system call and either kernel debugging 782 is enabled or VHE is in use. 783 784 Work around the erratum by triggering a dummy step exception 785 when handling a system call from a task that is being stepped 786 in a VHE configuration of the kernel. 787 788 If unsure, say Y. 789 790config ARM64_ERRATUM_1542419 791 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 792 help 793 This option adds a workaround for ARM Neoverse-N1 erratum 794 1542419. 795 796 Affected Neoverse-N1 cores could execute a stale instruction when 797 modified by another CPU. The workaround depends on a firmware 798 counterpart. 799 800 Workaround the issue by hiding the DIC feature from EL0. This 801 forces user-space to perform cache maintenance. 802 803 If unsure, say N. 804 805config ARM64_ERRATUM_1508412 806 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 807 default y 808 help 809 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 810 811 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 812 of a store-exclusive or read of PAR_EL1 and a load with device or 813 non-cacheable memory attributes. The workaround depends on a firmware 814 counterpart. 815 816 KVM guests must also have the workaround implemented or they can 817 deadlock the system. 818 819 Work around the issue by inserting DMB SY barriers around PAR_EL1 820 register reads and warning KVM users. The DMB barrier is sufficient 821 to prevent a speculative PAR_EL1 read. 822 823 If unsure, say Y. 824 825config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 826 bool 827 828config ARM64_ERRATUM_2051678 829 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 830 default y 831 help 832 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 833 Affected Cortex-A510 might not respect the ordering rules for 834 hardware update of the page table's dirty bit. The workaround 835 is to not enable the feature on affected CPUs. 836 837 If unsure, say Y. 838 839config ARM64_ERRATUM_2077057 840 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 841 default y 842 help 843 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 844 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 845 expected, but a Pointer Authentication trap is taken instead. The 846 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 847 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 848 849 This can only happen when EL2 is stepping EL1. 850 851 When these conditions occur, the SPSR_EL2 value is unchanged from the 852 previous guest entry, and can be restored from the in-memory copy. 853 854 If unsure, say Y. 855 856config ARM64_ERRATUM_2658417 857 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 858 default y 859 help 860 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 861 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 862 BFMMLA or VMMLA instructions in rare circumstances when a pair of 863 A510 CPUs are using shared neon hardware. As the sharing is not 864 discoverable by the kernel, hide the BF16 HWCAP to indicate that 865 user-space should not be using these instructions. 866 867 If unsure, say Y. 868 869config ARM64_ERRATUM_2119858 870 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 871 default y 872 depends on CORESIGHT_TRBE 873 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 874 help 875 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 876 877 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 878 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 879 the event of a WRAP event. 880 881 Work around the issue by always making sure we move the TRBPTR_EL1 by 882 256 bytes before enabling the buffer and filling the first 256 bytes of 883 the buffer with ETM ignore packets upon disabling. 884 885 If unsure, say Y. 886 887config ARM64_ERRATUM_2139208 888 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 889 default y 890 depends on CORESIGHT_TRBE 891 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 892 help 893 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 894 895 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 896 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 897 the event of a WRAP event. 898 899 Work around the issue by always making sure we move the TRBPTR_EL1 by 900 256 bytes before enabling the buffer and filling the first 256 bytes of 901 the buffer with ETM ignore packets upon disabling. 902 903 If unsure, say Y. 904 905config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 906 bool 907 908config ARM64_ERRATUM_2054223 909 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 910 default y 911 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 912 help 913 Enable workaround for ARM Cortex-A710 erratum 2054223 914 915 Affected cores may fail to flush the trace data on a TSB instruction, when 916 the PE is in trace prohibited state. This will cause losing a few bytes 917 of the trace cached. 918 919 Workaround is to issue two TSB consecutively on affected cores. 920 921 If unsure, say Y. 922 923config ARM64_ERRATUM_2067961 924 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 925 default y 926 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 927 help 928 Enable workaround for ARM Neoverse-N2 erratum 2067961 929 930 Affected cores may fail to flush the trace data on a TSB instruction, when 931 the PE is in trace prohibited state. This will cause losing a few bytes 932 of the trace cached. 933 934 Workaround is to issue two TSB consecutively on affected cores. 935 936 If unsure, say Y. 937 938config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 939 bool 940 941config ARM64_ERRATUM_2253138 942 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 943 depends on CORESIGHT_TRBE 944 default y 945 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 946 help 947 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 948 949 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 950 for TRBE. Under some conditions, the TRBE might generate a write to the next 951 virtually addressed page following the last page of the TRBE address space 952 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 953 954 Work around this in the driver by always making sure that there is a 955 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 956 957 If unsure, say Y. 958 959config ARM64_ERRATUM_2224489 960 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 961 depends on CORESIGHT_TRBE 962 default y 963 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 964 help 965 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 966 967 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 968 for TRBE. Under some conditions, the TRBE might generate a write to the next 969 virtually addressed page following the last page of the TRBE address space 970 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 971 972 Work around this in the driver by always making sure that there is a 973 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 974 975 If unsure, say Y. 976 977config ARM64_ERRATUM_2441009 978 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 979 select ARM64_WORKAROUND_REPEAT_TLBI 980 help 981 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 982 983 Under very rare circumstances, affected Cortex-A510 CPUs 984 may not handle a race between a break-before-make sequence on one 985 CPU, and another CPU accessing the same page. This could allow a 986 store to a page that has been unmapped. 987 988 Work around this by adding the affected CPUs to the list that needs 989 TLB sequences to be done twice. 990 991 If unsure, say N. 992 993config ARM64_ERRATUM_2064142 994 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 995 depends on CORESIGHT_TRBE 996 default y 997 help 998 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 999 1000 Affected Cortex-A510 core might fail to write into system registers after the 1001 TRBE has been disabled. Under some conditions after the TRBE has been disabled 1002 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 1003 and TRBTRG_EL1 will be ignored and will not be effected. 1004 1005 Work around this in the driver by executing TSB CSYNC and DSB after collection 1006 is stopped and before performing a system register write to one of the affected 1007 registers. 1008 1009 If unsure, say Y. 1010 1011config ARM64_ERRATUM_2038923 1012 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1013 depends on CORESIGHT_TRBE 1014 default y 1015 help 1016 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1017 1018 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1019 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1020 might be corrupted. This happens after TRBE buffer has been enabled by setting 1021 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1022 execution changes from a context, in which trace is prohibited to one where it 1023 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1024 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1025 the trace buffer state might be corrupted. 1026 1027 Work around this in the driver by preventing an inconsistent view of whether the 1028 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1029 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1030 two ISB instructions if no ERET is to take place. 1031 1032 If unsure, say Y. 1033 1034config ARM64_ERRATUM_1902691 1035 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1036 depends on CORESIGHT_TRBE 1037 default y 1038 help 1039 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1040 1041 Affected Cortex-A510 core might cause trace data corruption, when being written 1042 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1043 trace data. 1044 1045 Work around this problem in the driver by just preventing TRBE initialization on 1046 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1047 on such implementations. This will cover the kernel for any firmware that doesn't 1048 do this already. 1049 1050 If unsure, say Y. 1051 1052config ARM64_ERRATUM_2457168 1053 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1054 depends on ARM64_AMU_EXTN 1055 default y 1056 help 1057 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1058 1059 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1060 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1061 incorrectly giving a significantly higher output value. 1062 1063 Work around this problem by returning 0 when reading the affected counter in 1064 key locations that results in disabling all users of this counter. This effect 1065 is the same to firmware disabling affected counters. 1066 1067 If unsure, say Y. 1068 1069config ARM64_ERRATUM_2645198 1070 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1071 default y 1072 help 1073 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1074 1075 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1076 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1077 next instruction abort caused by permission fault. 1078 1079 Only user-space does executable to non-executable permission transition via 1080 mprotect() system call. Workaround the problem by doing a break-before-make 1081 TLB invalidation, for all changes to executable user space mappings. 1082 1083 If unsure, say Y. 1084 1085config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1086 bool 1087 1088config ARM64_ERRATUM_2966298 1089 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1090 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1091 default y 1092 help 1093 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1094 1095 On an affected Cortex-A520 core, a speculatively executed unprivileged 1096 load might leak data from a privileged level via a cache side channel. 1097 1098 Work around this problem by executing a TLBI before returning to EL0. 1099 1100 If unsure, say Y. 1101 1102config ARM64_ERRATUM_3117295 1103 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1104 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1105 default y 1106 help 1107 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1108 1109 On an affected Cortex-A510 core, a speculatively executed unprivileged 1110 load might leak data from a privileged level via a cache side channel. 1111 1112 Work around this problem by executing a TLBI before returning to EL0. 1113 1114 If unsure, say Y. 1115 1116config ARM64_ERRATUM_3194386 1117 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1118 default y 1119 help 1120 This option adds the workaround for the following errata: 1121 1122 * ARM Cortex-A76 erratum 3324349 1123 * ARM Cortex-A77 erratum 3324348 1124 * ARM Cortex-A78 erratum 3324344 1125 * ARM Cortex-A78C erratum 3324346 1126 * ARM Cortex-A78C erratum 3324347 1127 * ARM Cortex-A710 erratam 3324338 1128 * ARM Cortex-A715 errartum 3456084 1129 * ARM Cortex-A720 erratum 3456091 1130 * ARM Cortex-A725 erratum 3456106 1131 * ARM Cortex-X1 erratum 3324344 1132 * ARM Cortex-X1C erratum 3324346 1133 * ARM Cortex-X2 erratum 3324338 1134 * ARM Cortex-X3 erratum 3324335 1135 * ARM Cortex-X4 erratum 3194386 1136 * ARM Cortex-X925 erratum 3324334 1137 * ARM Neoverse-N1 erratum 3324349 1138 * ARM Neoverse N2 erratum 3324339 1139 * ARM Neoverse-N3 erratum 3456111 1140 * ARM Neoverse-V1 erratum 3324341 1141 * ARM Neoverse V2 erratum 3324336 1142 * ARM Neoverse-V3 erratum 3312417 1143 1144 On affected cores "MSR SSBS, #0" instructions may not affect 1145 subsequent speculative instructions, which may permit unexepected 1146 speculative store bypassing. 1147 1148 Work around this problem by placing a Speculation Barrier (SB) or 1149 Instruction Synchronization Barrier (ISB) after kernel changes to 1150 SSBS. The presence of the SSBS special-purpose register is hidden 1151 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1152 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1153 1154 If unsure, say Y. 1155 1156config CAVIUM_ERRATUM_22375 1157 bool "Cavium erratum 22375, 24313" 1158 default y 1159 help 1160 Enable workaround for errata 22375 and 24313. 1161 1162 This implements two gicv3-its errata workarounds for ThunderX. Both 1163 with a small impact affecting only ITS table allocation. 1164 1165 erratum 22375: only alloc 8MB table size 1166 erratum 24313: ignore memory access type 1167 1168 The fixes are in ITS initialization and basically ignore memory access 1169 type and table size provided by the TYPER and BASER registers. 1170 1171 If unsure, say Y. 1172 1173config CAVIUM_ERRATUM_23144 1174 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1175 depends on NUMA 1176 default y 1177 help 1178 ITS SYNC command hang for cross node io and collections/cpu mapping. 1179 1180 If unsure, say Y. 1181 1182config CAVIUM_ERRATUM_23154 1183 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1184 default y 1185 help 1186 The ThunderX GICv3 implementation requires a modified version for 1187 reading the IAR status to ensure data synchronization 1188 (access to icc_iar1_el1 is not sync'ed before and after). 1189 1190 It also suffers from erratum 38545 (also present on Marvell's 1191 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1192 spuriously presented to the CPU interface. 1193 1194 If unsure, say Y. 1195 1196config CAVIUM_ERRATUM_27456 1197 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1198 default y 1199 help 1200 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1201 instructions may cause the icache to become corrupted if it 1202 contains data for a non-current ASID. The fix is to 1203 invalidate the icache when changing the mm context. 1204 1205 If unsure, say Y. 1206 1207config CAVIUM_ERRATUM_30115 1208 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1209 default y 1210 help 1211 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1212 1.2, and T83 Pass 1.0, KVM guest execution may disable 1213 interrupts in host. Trapping both GICv3 group-0 and group-1 1214 accesses sidesteps the issue. 1215 1216 If unsure, say Y. 1217 1218config CAVIUM_TX2_ERRATUM_219 1219 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1220 default y 1221 help 1222 On Cavium ThunderX2, a load, store or prefetch instruction between a 1223 TTBR update and the corresponding context synchronizing operation can 1224 cause a spurious Data Abort to be delivered to any hardware thread in 1225 the CPU core. 1226 1227 Work around the issue by avoiding the problematic code sequence and 1228 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1229 trap handler performs the corresponding register access, skips the 1230 instruction and ensures context synchronization by virtue of the 1231 exception return. 1232 1233 If unsure, say Y. 1234 1235config FUJITSU_ERRATUM_010001 1236 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1237 default y 1238 help 1239 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1240 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1241 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1242 This fault occurs under a specific hardware condition when a 1243 load/store instruction performs an address translation using: 1244 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1245 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1246 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1247 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1248 1249 The workaround is to ensure these bits are clear in TCR_ELx. 1250 The workaround only affects the Fujitsu-A64FX. 1251 1252 If unsure, say Y. 1253 1254config HISILICON_ERRATUM_161600802 1255 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1256 default y 1257 help 1258 The HiSilicon Hip07 SoC uses the wrong redistributor base 1259 when issued ITS commands such as VMOVP and VMAPP, and requires 1260 a 128kB offset to be applied to the target address in this commands. 1261 1262 If unsure, say Y. 1263 1264config HISILICON_ERRATUM_162100801 1265 bool "Hip09 162100801 erratum support" 1266 default y 1267 help 1268 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1269 during unmapping operation, which will cause some vSGIs lost. 1270 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1271 after VMOVP. 1272 1273 If unsure, say Y. 1274 1275config QCOM_FALKOR_ERRATUM_1003 1276 bool "Falkor E1003: Incorrect translation due to ASID change" 1277 default y 1278 help 1279 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1280 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1281 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1282 then only for entries in the walk cache, since the leaf translation 1283 is unchanged. Work around the erratum by invalidating the walk cache 1284 entries for the trampoline before entering the kernel proper. 1285 1286config QCOM_FALKOR_ERRATUM_1009 1287 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1288 default y 1289 select ARM64_WORKAROUND_REPEAT_TLBI 1290 help 1291 On Falkor v1, the CPU may prematurely complete a DSB following a 1292 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1293 one more time to fix the issue. 1294 1295 If unsure, say Y. 1296 1297config QCOM_QDF2400_ERRATUM_0065 1298 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1299 default y 1300 help 1301 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1302 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1303 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1304 1305 If unsure, say Y. 1306 1307config QCOM_FALKOR_ERRATUM_E1041 1308 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1309 default y 1310 help 1311 Falkor CPU may speculatively fetch instructions from an improper 1312 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1313 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1314 1315 If unsure, say Y. 1316 1317config NVIDIA_CARMEL_CNP_ERRATUM 1318 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1319 default y 1320 help 1321 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1322 invalidate shared TLB entries installed by a different core, as it would 1323 on standard ARM cores. 1324 1325 If unsure, say Y. 1326 1327config ROCKCHIP_ERRATUM_3568002 1328 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1329 default y 1330 help 1331 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1332 addressing limited to the first 32bit of physical address space. 1333 1334 If unsure, say Y. 1335 1336config ROCKCHIP_ERRATUM_3588001 1337 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1338 default y 1339 help 1340 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1341 This means, that its sharability feature may not be used, even though it 1342 is supported by the IP itself. 1343 1344 If unsure, say Y. 1345 1346config SOCIONEXT_SYNQUACER_PREITS 1347 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1348 default y 1349 help 1350 Socionext Synquacer SoCs implement a separate h/w block to generate 1351 MSI doorbell writes with non-zero values for the device ID. 1352 1353 If unsure, say Y. 1354 1355endmenu # "ARM errata workarounds via the alternatives framework" 1356 1357choice 1358 prompt "Page size" 1359 default ARM64_4K_PAGES 1360 help 1361 Page size (translation granule) configuration. 1362 1363config ARM64_4K_PAGES 1364 bool "4KB" 1365 select HAVE_PAGE_SIZE_4KB 1366 help 1367 This feature enables 4KB pages support. 1368 1369config ARM64_16K_PAGES 1370 bool "16KB" 1371 select HAVE_PAGE_SIZE_16KB 1372 help 1373 The system will use 16KB pages support. AArch32 emulation 1374 requires applications compiled with 16K (or a multiple of 16K) 1375 aligned segments. 1376 1377config ARM64_64K_PAGES 1378 bool "64KB" 1379 select HAVE_PAGE_SIZE_64KB 1380 help 1381 This feature enables 64KB pages support (4KB by default) 1382 allowing only two levels of page tables and faster TLB 1383 look-up. AArch32 emulation requires applications compiled 1384 with 64K aligned segments. 1385 1386endchoice 1387 1388choice 1389 prompt "Virtual address space size" 1390 default ARM64_VA_BITS_52 1391 help 1392 Allows choosing one of multiple possible virtual address 1393 space sizes. The level of translation table is determined by 1394 a combination of page size and virtual address space size. 1395 1396config ARM64_VA_BITS_36 1397 bool "36-bit" if EXPERT 1398 depends on PAGE_SIZE_16KB 1399 1400config ARM64_VA_BITS_39 1401 bool "39-bit" 1402 depends on PAGE_SIZE_4KB 1403 1404config ARM64_VA_BITS_42 1405 bool "42-bit" 1406 depends on PAGE_SIZE_64KB 1407 1408config ARM64_VA_BITS_47 1409 bool "47-bit" 1410 depends on PAGE_SIZE_16KB 1411 1412config ARM64_VA_BITS_48 1413 bool "48-bit" 1414 1415config ARM64_VA_BITS_52 1416 bool "52-bit" 1417 help 1418 Enable 52-bit virtual addressing for userspace when explicitly 1419 requested via a hint to mmap(). The kernel will also use 52-bit 1420 virtual addresses for its own mappings (provided HW support for 1421 this feature is available, otherwise it reverts to 48-bit). 1422 1423 NOTE: Enabling 52-bit virtual addressing in conjunction with 1424 ARMv8.3 Pointer Authentication will result in the PAC being 1425 reduced from 7 bits to 3 bits, which may have a significant 1426 impact on its susceptibility to brute-force attacks. 1427 1428 If unsure, select 48-bit virtual addressing instead. 1429 1430endchoice 1431 1432config ARM64_FORCE_52BIT 1433 bool "Force 52-bit virtual addresses for userspace" 1434 depends on ARM64_VA_BITS_52 && EXPERT 1435 help 1436 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1437 to maintain compatibility with older software by providing 48-bit VAs 1438 unless a hint is supplied to mmap. 1439 1440 This configuration option disables the 48-bit compatibility logic, and 1441 forces all userspace addresses to be 52-bit on HW that supports it. One 1442 should only enable this configuration option for stress testing userspace 1443 memory management code. If unsure say N here. 1444 1445config ARM64_VA_BITS 1446 int 1447 default 36 if ARM64_VA_BITS_36 1448 default 39 if ARM64_VA_BITS_39 1449 default 42 if ARM64_VA_BITS_42 1450 default 47 if ARM64_VA_BITS_47 1451 default 48 if ARM64_VA_BITS_48 1452 default 52 if ARM64_VA_BITS_52 1453 1454choice 1455 prompt "Physical address space size" 1456 default ARM64_PA_BITS_48 1457 help 1458 Choose the maximum physical address range that the kernel will 1459 support. 1460 1461config ARM64_PA_BITS_48 1462 bool "48-bit" 1463 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1464 1465config ARM64_PA_BITS_52 1466 bool "52-bit" 1467 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1468 help 1469 Enable support for a 52-bit physical address space, introduced as 1470 part of the ARMv8.2-LPA extension. 1471 1472 With this enabled, the kernel will also continue to work on CPUs that 1473 do not support ARMv8.2-LPA, but with some added memory overhead (and 1474 minor performance overhead). 1475 1476endchoice 1477 1478config ARM64_PA_BITS 1479 int 1480 default 48 if ARM64_PA_BITS_48 1481 default 52 if ARM64_PA_BITS_52 1482 1483config ARM64_LPA2 1484 def_bool y 1485 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1486 1487choice 1488 prompt "Endianness" 1489 default CPU_LITTLE_ENDIAN 1490 help 1491 Select the endianness of data accesses performed by the CPU. Userspace 1492 applications will need to be compiled and linked for the endianness 1493 that is selected here. 1494 1495config CPU_BIG_ENDIAN 1496 bool "Build big-endian kernel" 1497 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1498 depends on AS_IS_GNU || AS_VERSION >= 150000 1499 help 1500 Say Y if you plan on running a kernel with a big-endian userspace. 1501 1502config CPU_LITTLE_ENDIAN 1503 bool "Build little-endian kernel" 1504 help 1505 Say Y if you plan on running a kernel with a little-endian userspace. 1506 This is usually the case for distributions targeting arm64. 1507 1508endchoice 1509 1510config SCHED_MC 1511 bool "Multi-core scheduler support" 1512 help 1513 Multi-core scheduler support improves the CPU scheduler's decision 1514 making when dealing with multi-core CPU chips at a cost of slightly 1515 increased overhead in some places. If unsure say N here. 1516 1517config SCHED_CLUSTER 1518 bool "Cluster scheduler support" 1519 help 1520 Cluster scheduler support improves the CPU scheduler's decision 1521 making when dealing with machines that have clusters of CPUs. 1522 Cluster usually means a couple of CPUs which are placed closely 1523 by sharing mid-level caches, last-level cache tags or internal 1524 busses. 1525 1526config SCHED_SMT 1527 bool "SMT scheduler support" 1528 help 1529 Improves the CPU scheduler's decision making when dealing with 1530 MultiThreading at a cost of slightly increased overhead in some 1531 places. If unsure say N here. 1532 1533config NR_CPUS 1534 int "Maximum number of CPUs (2-4096)" 1535 range 2 4096 1536 default "512" 1537 1538config HOTPLUG_CPU 1539 bool "Support for hot-pluggable CPUs" 1540 select GENERIC_IRQ_MIGRATION 1541 help 1542 Say Y here to experiment with turning CPUs off and on. CPUs 1543 can be controlled through /sys/devices/system/cpu. 1544 1545# Common NUMA Features 1546config NUMA 1547 bool "NUMA Memory Allocation and Scheduler Support" 1548 select GENERIC_ARCH_NUMA 1549 select OF_NUMA 1550 select HAVE_SETUP_PER_CPU_AREA 1551 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1552 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1553 select USE_PERCPU_NUMA_NODE_ID 1554 help 1555 Enable NUMA (Non-Uniform Memory Access) support. 1556 1557 The kernel will try to allocate memory used by a CPU on the 1558 local memory of the CPU and add some more 1559 NUMA awareness to the kernel. 1560 1561config NODES_SHIFT 1562 int "Maximum NUMA Nodes (as a power of 2)" 1563 range 1 10 1564 default "4" 1565 depends on NUMA 1566 help 1567 Specify the maximum number of NUMA Nodes available on the target 1568 system. Increases memory reserved to accommodate various tables. 1569 1570source "kernel/Kconfig.hz" 1571 1572config ARCH_SPARSEMEM_ENABLE 1573 def_bool y 1574 select SPARSEMEM_VMEMMAP_ENABLE 1575 select SPARSEMEM_VMEMMAP 1576 1577config HW_PERF_EVENTS 1578 def_bool y 1579 depends on ARM_PMU 1580 1581# Supported by clang >= 7.0 or GCC >= 12.0.0 1582config CC_HAVE_SHADOW_CALL_STACK 1583 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1584 1585config PARAVIRT 1586 bool "Enable paravirtualization code" 1587 help 1588 This changes the kernel so it can modify itself when it is run 1589 under a hypervisor, potentially improving performance significantly 1590 over full virtualization. 1591 1592config PARAVIRT_TIME_ACCOUNTING 1593 bool "Paravirtual steal time accounting" 1594 select PARAVIRT 1595 help 1596 Select this option to enable fine granularity task steal time 1597 accounting. Time spent executing other tasks in parallel with 1598 the current vCPU is discounted from the vCPU power. To account for 1599 that, there can be a small performance impact. 1600 1601 If in doubt, say N here. 1602 1603config ARCH_SUPPORTS_KEXEC 1604 def_bool PM_SLEEP_SMP 1605 1606config ARCH_SUPPORTS_KEXEC_FILE 1607 def_bool y 1608 1609config ARCH_SELECTS_KEXEC_FILE 1610 def_bool y 1611 depends on KEXEC_FILE 1612 select HAVE_IMA_KEXEC if IMA 1613 1614config ARCH_SUPPORTS_KEXEC_SIG 1615 def_bool y 1616 1617config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1618 def_bool y 1619 1620config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1621 def_bool y 1622 1623config ARCH_SUPPORTS_KEXEC_HANDOVER 1624 def_bool y 1625 1626config ARCH_SUPPORTS_CRASH_DUMP 1627 def_bool y 1628 1629config ARCH_DEFAULT_CRASH_DUMP 1630 def_bool y 1631 1632config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1633 def_bool CRASH_RESERVE 1634 1635config TRANS_TABLE 1636 def_bool y 1637 depends on HIBERNATION || KEXEC_CORE 1638 1639config XEN_DOM0 1640 def_bool y 1641 depends on XEN 1642 1643config XEN 1644 bool "Xen guest support on ARM64" 1645 depends on ARM64 && OF 1646 select SWIOTLB_XEN 1647 select PARAVIRT 1648 help 1649 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1650 1651# include/linux/mmzone.h requires the following to be true: 1652# 1653# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1654# 1655# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1656# 1657# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1658# ----+-------------------+--------------+----------------------+-------------------------+ 1659# 4K | 27 | 12 | 15 | 10 | 1660# 16K | 27 | 14 | 13 | 11 | 1661# 64K | 29 | 16 | 13 | 13 | 1662config ARCH_FORCE_MAX_ORDER 1663 int 1664 default "13" if ARM64_64K_PAGES 1665 default "11" if ARM64_16K_PAGES 1666 default "10" 1667 help 1668 The kernel page allocator limits the size of maximal physically 1669 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1670 defines the maximal power of two of number of pages that can be 1671 allocated as a single contiguous block. This option allows 1672 overriding the default setting when ability to allocate very 1673 large blocks of physically contiguous memory is required. 1674 1675 The maximal size of allocation cannot exceed the size of the 1676 section, so the value of MAX_PAGE_ORDER should satisfy 1677 1678 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1679 1680 Don't change if unsure. 1681 1682config UNMAP_KERNEL_AT_EL0 1683 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1684 default y 1685 help 1686 Speculation attacks against some high-performance processors can 1687 be used to bypass MMU permission checks and leak kernel data to 1688 userspace. This can be defended against by unmapping the kernel 1689 when running in userspace, mapping it back in on exception entry 1690 via a trampoline page in the vector table. 1691 1692 If unsure, say Y. 1693 1694config MITIGATE_SPECTRE_BRANCH_HISTORY 1695 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1696 default y 1697 help 1698 Speculation attacks against some high-performance processors can 1699 make use of branch history to influence future speculation. 1700 When taking an exception from user-space, a sequence of branches 1701 or a firmware call overwrites the branch history. 1702 1703config RODATA_FULL_DEFAULT_ENABLED 1704 bool "Apply r/o permissions of VM areas also to their linear aliases" 1705 default y 1706 help 1707 Apply read-only attributes of VM areas to the linear alias of 1708 the backing pages as well. This prevents code or read-only data 1709 from being modified (inadvertently or intentionally) via another 1710 mapping of the same memory page. This additional enhancement can 1711 be turned off at runtime by passing rodata=[off|on] (and turned on 1712 with rodata=full if this option is set to 'n') 1713 1714 This requires the linear region to be mapped down to pages, 1715 which may adversely affect performance in some cases. 1716 1717config ARM64_SW_TTBR0_PAN 1718 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1719 depends on !KCSAN 1720 select ARM64_PAN 1721 help 1722 Enabling this option prevents the kernel from accessing 1723 user-space memory directly by pointing TTBR0_EL1 to a reserved 1724 zeroed area and reserved ASID. The user access routines 1725 restore the valid TTBR0_EL1 temporarily. 1726 1727config ARM64_TAGGED_ADDR_ABI 1728 bool "Enable the tagged user addresses syscall ABI" 1729 default y 1730 help 1731 When this option is enabled, user applications can opt in to a 1732 relaxed ABI via prctl() allowing tagged addresses to be passed 1733 to system calls as pointer arguments. For details, see 1734 Documentation/arch/arm64/tagged-address-abi.rst. 1735 1736menuconfig COMPAT 1737 bool "Kernel support for 32-bit EL0" 1738 depends on ARM64_4K_PAGES || EXPERT 1739 select HAVE_UID16 1740 select OLD_SIGSUSPEND3 1741 select COMPAT_OLD_SIGACTION 1742 help 1743 This option enables support for a 32-bit EL0 running under a 64-bit 1744 kernel at EL1. AArch32-specific components such as system calls, 1745 the user helper functions, VFP support and the ptrace interface are 1746 handled appropriately by the kernel. 1747 1748 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1749 that you will only be able to execute AArch32 binaries that were compiled 1750 with page size aligned segments. 1751 1752 If you want to execute 32-bit userspace applications, say Y. 1753 1754if COMPAT 1755 1756config KUSER_HELPERS 1757 bool "Enable kuser helpers page for 32-bit applications" 1758 default y 1759 help 1760 Warning: disabling this option may break 32-bit user programs. 1761 1762 Provide kuser helpers to compat tasks. The kernel provides 1763 helper code to userspace in read only form at a fixed location 1764 to allow userspace to be independent of the CPU type fitted to 1765 the system. This permits binaries to be run on ARMv4 through 1766 to ARMv8 without modification. 1767 1768 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1769 1770 However, the fixed address nature of these helpers can be used 1771 by ROP (return orientated programming) authors when creating 1772 exploits. 1773 1774 If all of the binaries and libraries which run on your platform 1775 are built specifically for your platform, and make no use of 1776 these helpers, then you can turn this option off to hinder 1777 such exploits. However, in that case, if a binary or library 1778 relying on those helpers is run, it will not function correctly. 1779 1780 Say N here only if you are absolutely certain that you do not 1781 need these helpers; otherwise, the safe option is to say Y. 1782 1783config COMPAT_VDSO 1784 bool "Enable vDSO for 32-bit applications" 1785 depends on !CPU_BIG_ENDIAN 1786 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1787 select GENERIC_COMPAT_VDSO 1788 default y 1789 help 1790 Place in the process address space of 32-bit applications an 1791 ELF shared object providing fast implementations of gettimeofday 1792 and clock_gettime. 1793 1794 You must have a 32-bit build of glibc 2.22 or later for programs 1795 to seamlessly take advantage of this. 1796 1797config THUMB2_COMPAT_VDSO 1798 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1799 depends on COMPAT_VDSO 1800 default y 1801 help 1802 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1803 otherwise with '-marm'. 1804 1805config COMPAT_ALIGNMENT_FIXUPS 1806 bool "Fix up misaligned multi-word loads and stores in user space" 1807 1808menuconfig ARMV8_DEPRECATED 1809 bool "Emulate deprecated/obsolete ARMv8 instructions" 1810 depends on SYSCTL 1811 help 1812 Legacy software support may require certain instructions 1813 that have been deprecated or obsoleted in the architecture. 1814 1815 Enable this config to enable selective emulation of these 1816 features. 1817 1818 If unsure, say Y 1819 1820if ARMV8_DEPRECATED 1821 1822config SWP_EMULATION 1823 bool "Emulate SWP/SWPB instructions" 1824 help 1825 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1826 they are always undefined. Say Y here to enable software 1827 emulation of these instructions for userspace using LDXR/STXR. 1828 This feature can be controlled at runtime with the abi.swp 1829 sysctl which is disabled by default. 1830 1831 In some older versions of glibc [<=2.8] SWP is used during futex 1832 trylock() operations with the assumption that the code will not 1833 be preempted. This invalid assumption may be more likely to fail 1834 with SWP emulation enabled, leading to deadlock of the user 1835 application. 1836 1837 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1838 on an external transaction monitoring block called a global 1839 monitor to maintain update atomicity. If your system does not 1840 implement a global monitor, this option can cause programs that 1841 perform SWP operations to uncached memory to deadlock. 1842 1843 If unsure, say Y 1844 1845config CP15_BARRIER_EMULATION 1846 bool "Emulate CP15 Barrier instructions" 1847 help 1848 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1849 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1850 strongly recommended to use the ISB, DSB, and DMB 1851 instructions instead. 1852 1853 Say Y here to enable software emulation of these 1854 instructions for AArch32 userspace code. When this option is 1855 enabled, CP15 barrier usage is traced which can help 1856 identify software that needs updating. This feature can be 1857 controlled at runtime with the abi.cp15_barrier sysctl. 1858 1859 If unsure, say Y 1860 1861config SETEND_EMULATION 1862 bool "Emulate SETEND instruction" 1863 help 1864 The SETEND instruction alters the data-endianness of the 1865 AArch32 EL0, and is deprecated in ARMv8. 1866 1867 Say Y here to enable software emulation of the instruction 1868 for AArch32 userspace code. This feature can be controlled 1869 at runtime with the abi.setend sysctl. 1870 1871 Note: All the cpus on the system must have mixed endian support at EL0 1872 for this feature to be enabled. If a new CPU - which doesn't support mixed 1873 endian - is hotplugged in after this feature has been enabled, there could 1874 be unexpected results in the applications. 1875 1876 If unsure, say Y 1877endif # ARMV8_DEPRECATED 1878 1879endif # COMPAT 1880 1881menu "ARMv8.1 architectural features" 1882 1883config ARM64_HW_AFDBM 1884 bool "Support for hardware updates of the Access and Dirty page flags" 1885 default y 1886 help 1887 The ARMv8.1 architecture extensions introduce support for 1888 hardware updates of the access and dirty information in page 1889 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1890 capable processors, accesses to pages with PTE_AF cleared will 1891 set this bit instead of raising an access flag fault. 1892 Similarly, writes to read-only pages with the DBM bit set will 1893 clear the read-only bit (AP[2]) instead of raising a 1894 permission fault. 1895 1896 Kernels built with this configuration option enabled continue 1897 to work on pre-ARMv8.1 hardware and the performance impact is 1898 minimal. If unsure, say Y. 1899 1900config ARM64_PAN 1901 bool "Enable support for Privileged Access Never (PAN)" 1902 default y 1903 help 1904 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1905 prevents the kernel or hypervisor from accessing user-space (EL0) 1906 memory directly. 1907 1908 Choosing this option will cause any unprotected (not using 1909 copy_to_user et al) memory access to fail with a permission fault. 1910 1911 The feature is detected at runtime, and will remain as a 'nop' 1912 instruction if the cpu does not implement the feature. 1913 1914config ARM64_LSE_ATOMICS 1915 bool 1916 default ARM64_USE_LSE_ATOMICS 1917 1918config ARM64_USE_LSE_ATOMICS 1919 bool "Atomic instructions" 1920 default y 1921 help 1922 As part of the Large System Extensions, ARMv8.1 introduces new 1923 atomic instructions that are designed specifically to scale in 1924 very large systems. 1925 1926 Say Y here to make use of these instructions for the in-kernel 1927 atomic routines. This incurs a small overhead on CPUs that do 1928 not support these instructions. 1929 1930endmenu # "ARMv8.1 architectural features" 1931 1932menu "ARMv8.2 architectural features" 1933 1934config ARM64_PMEM 1935 bool "Enable support for persistent memory" 1936 select ARCH_HAS_PMEM_API 1937 select ARCH_HAS_UACCESS_FLUSHCACHE 1938 help 1939 Say Y to enable support for the persistent memory API based on the 1940 ARMv8.2 DCPoP feature. 1941 1942 The feature is detected at runtime, and the kernel will use DC CVAC 1943 operations if DC CVAP is not supported (following the behaviour of 1944 DC CVAP itself if the system does not define a point of persistence). 1945 1946config ARM64_RAS_EXTN 1947 bool "Enable support for RAS CPU Extensions" 1948 default y 1949 help 1950 CPUs that support the Reliability, Availability and Serviceability 1951 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1952 errors, classify them and report them to software. 1953 1954 On CPUs with these extensions system software can use additional 1955 barriers to determine if faults are pending and read the 1956 classification from a new set of registers. 1957 1958 Selecting this feature will allow the kernel to use these barriers 1959 and access the new registers if the system supports the extension. 1960 Platform RAS features may additionally depend on firmware support. 1961 1962config ARM64_CNP 1963 bool "Enable support for Common Not Private (CNP) translations" 1964 default y 1965 help 1966 Common Not Private (CNP) allows translation table entries to 1967 be shared between different PEs in the same inner shareable 1968 domain, so the hardware can use this fact to optimise the 1969 caching of such entries in the TLB. 1970 1971 Selecting this option allows the CNP feature to be detected 1972 at runtime, and does not affect PEs that do not implement 1973 this feature. 1974 1975endmenu # "ARMv8.2 architectural features" 1976 1977menu "ARMv8.3 architectural features" 1978 1979config ARM64_PTR_AUTH 1980 bool "Enable support for pointer authentication" 1981 default y 1982 help 1983 Pointer authentication (part of the ARMv8.3 Extensions) provides 1984 instructions for signing and authenticating pointers against secret 1985 keys, which can be used to mitigate Return Oriented Programming (ROP) 1986 and other attacks. 1987 1988 This option enables these instructions at EL0 (i.e. for userspace). 1989 Choosing this option will cause the kernel to initialise secret keys 1990 for each process at exec() time, with these keys being 1991 context-switched along with the process. 1992 1993 The feature is detected at runtime. If the feature is not present in 1994 hardware it will not be advertised to userspace/KVM guest nor will it 1995 be enabled. 1996 1997 If the feature is present on the boot CPU but not on a late CPU, then 1998 the late CPU will be parked. Also, if the boot CPU does not have 1999 address auth and the late CPU has then the late CPU will still boot 2000 but with the feature disabled. On such a system, this option should 2001 not be selected. 2002 2003config ARM64_PTR_AUTH_KERNEL 2004 bool "Use pointer authentication for kernel" 2005 default y 2006 depends on ARM64_PTR_AUTH 2007 # Modern compilers insert a .note.gnu.property section note for PAC 2008 # which is only understood by binutils starting with version 2.33.1. 2009 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2010 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2011 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2012 help 2013 If the compiler supports the -mbranch-protection or 2014 -msign-return-address flag (e.g. GCC 7 or later), then this option 2015 will cause the kernel itself to be compiled with return address 2016 protection. In this case, and if the target hardware is known to 2017 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2018 disabled with minimal loss of protection. 2019 2020 This feature works with FUNCTION_GRAPH_TRACER option only if 2021 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2022 2023config CC_HAS_BRANCH_PROT_PAC_RET 2024 # GCC 9 or later, clang 8 or later 2025 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2026 2027config AS_HAS_CFI_NEGATE_RA_STATE 2028 # binutils 2.34+ 2029 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2030 2031endmenu # "ARMv8.3 architectural features" 2032 2033menu "ARMv8.4 architectural features" 2034 2035config ARM64_AMU_EXTN 2036 bool "Enable support for the Activity Monitors Unit CPU extension" 2037 default y 2038 help 2039 The activity monitors extension is an optional extension introduced 2040 by the ARMv8.4 CPU architecture. This enables support for version 1 2041 of the activity monitors architecture, AMUv1. 2042 2043 To enable the use of this extension on CPUs that implement it, say Y. 2044 2045 Note that for architectural reasons, firmware _must_ implement AMU 2046 support when running on CPUs that present the activity monitors 2047 extension. The required support is present in: 2048 * Version 1.5 and later of the ARM Trusted Firmware 2049 2050 For kernels that have this configuration enabled but boot with broken 2051 firmware, you may need to say N here until the firmware is fixed. 2052 Otherwise you may experience firmware panics or lockups when 2053 accessing the counter registers. Even if you are not observing these 2054 symptoms, the values returned by the register reads might not 2055 correctly reflect reality. Most commonly, the value read will be 0, 2056 indicating that the counter is not enabled. 2057 2058config ARM64_TLB_RANGE 2059 bool "Enable support for tlbi range feature" 2060 default y 2061 help 2062 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2063 range of input addresses. 2064 2065endmenu # "ARMv8.4 architectural features" 2066 2067menu "ARMv8.5 architectural features" 2068 2069config AS_HAS_ARMV8_5 2070 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2071 2072config ARM64_BTI 2073 bool "Branch Target Identification support" 2074 default y 2075 help 2076 Branch Target Identification (part of the ARMv8.5 Extensions) 2077 provides a mechanism to limit the set of locations to which computed 2078 branch instructions such as BR or BLR can jump. 2079 2080 To make use of BTI on CPUs that support it, say Y. 2081 2082 BTI is intended to provide complementary protection to other control 2083 flow integrity protection mechanisms, such as the Pointer 2084 authentication mechanism provided as part of the ARMv8.3 Extensions. 2085 For this reason, it does not make sense to enable this option without 2086 also enabling support for pointer authentication. Thus, when 2087 enabling this option you should also select ARM64_PTR_AUTH=y. 2088 2089 Userspace binaries must also be specifically compiled to make use of 2090 this mechanism. If you say N here or the hardware does not support 2091 BTI, such binaries can still run, but you get no additional 2092 enforcement of branch destinations. 2093 2094config ARM64_BTI_KERNEL 2095 bool "Use Branch Target Identification for kernel" 2096 default y 2097 depends on ARM64_BTI 2098 depends on ARM64_PTR_AUTH_KERNEL 2099 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2100 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2101 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2102 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2103 depends on !CC_IS_GCC 2104 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2105 help 2106 Build the kernel with Branch Target Identification annotations 2107 and enable enforcement of this for kernel code. When this option 2108 is enabled and the system supports BTI all kernel code including 2109 modular code must have BTI enabled. 2110 2111config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2112 # GCC 9 or later, clang 8 or later 2113 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2114 2115config ARM64_E0PD 2116 bool "Enable support for E0PD" 2117 default y 2118 help 2119 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2120 that EL0 accesses made via TTBR1 always fault in constant time, 2121 providing similar benefits to KASLR as those provided by KPTI, but 2122 with lower overhead and without disrupting legitimate access to 2123 kernel memory such as SPE. 2124 2125 This option enables E0PD for TTBR1 where available. 2126 2127config ARM64_AS_HAS_MTE 2128 # Initial support for MTE went in binutils 2.32.0, checked with 2129 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2130 # as a late addition to the final architecture spec (LDGM/STGM) 2131 # is only supported in the newer 2.32.x and 2.33 binutils 2132 # versions, hence the extra "stgm" instruction check below. 2133 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2134 2135config ARM64_MTE 2136 bool "Memory Tagging Extension support" 2137 default y 2138 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2139 depends on AS_HAS_ARMV8_5 2140 # Required for tag checking in the uaccess routines 2141 select ARM64_PAN 2142 select ARCH_HAS_SUBPAGE_FAULTS 2143 select ARCH_USES_HIGH_VMA_FLAGS 2144 select ARCH_USES_PG_ARCH_2 2145 select ARCH_USES_PG_ARCH_3 2146 help 2147 Memory Tagging (part of the ARMv8.5 Extensions) provides 2148 architectural support for run-time, always-on detection of 2149 various classes of memory error to aid with software debugging 2150 to eliminate vulnerabilities arising from memory-unsafe 2151 languages. 2152 2153 This option enables the support for the Memory Tagging 2154 Extension at EL0 (i.e. for userspace). 2155 2156 Selecting this option allows the feature to be detected at 2157 runtime. Any secondary CPU not implementing this feature will 2158 not be allowed a late bring-up. 2159 2160 Userspace binaries that want to use this feature must 2161 explicitly opt in. The mechanism for the userspace is 2162 described in: 2163 2164 Documentation/arch/arm64/memory-tagging-extension.rst. 2165 2166endmenu # "ARMv8.5 architectural features" 2167 2168menu "ARMv8.7 architectural features" 2169 2170config ARM64_EPAN 2171 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2172 default y 2173 depends on ARM64_PAN 2174 help 2175 Enhanced Privileged Access Never (EPAN) allows Privileged 2176 Access Never to be used with Execute-only mappings. 2177 2178 The feature is detected at runtime, and will remain disabled 2179 if the cpu does not implement the feature. 2180endmenu # "ARMv8.7 architectural features" 2181 2182config AS_HAS_MOPS 2183 def_bool $(as-instr,.arch_extension mops) 2184 2185menu "ARMv8.9 architectural features" 2186 2187config ARM64_POE 2188 prompt "Permission Overlay Extension" 2189 def_bool y 2190 select ARCH_USES_HIGH_VMA_FLAGS 2191 select ARCH_HAS_PKEYS 2192 help 2193 The Permission Overlay Extension is used to implement Memory 2194 Protection Keys. Memory Protection Keys provides a mechanism for 2195 enforcing page-based protections, but without requiring modification 2196 of the page tables when an application changes protection domains. 2197 2198 For details, see Documentation/core-api/protection-keys.rst 2199 2200 If unsure, say y. 2201 2202config ARCH_PKEY_BITS 2203 int 2204 default 3 2205 2206config ARM64_HAFT 2207 bool "Support for Hardware managed Access Flag for Table Descriptors" 2208 depends on ARM64_HW_AFDBM 2209 default y 2210 help 2211 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2212 Flag for Table descriptors. When enabled an architectural executed 2213 memory access will update the Access Flag in each Table descriptor 2214 which is accessed during the translation table walk and for which 2215 the Access Flag is 0. The Access Flag of the Table descriptor use 2216 the same bit of PTE_AF. 2217 2218 The feature will only be enabled if all the CPUs in the system 2219 support this feature. If unsure, say Y. 2220 2221endmenu # "ARMv8.9 architectural features" 2222 2223menu "v9.4 architectural features" 2224 2225config ARM64_GCS 2226 bool "Enable support for Guarded Control Stack (GCS)" 2227 default y 2228 select ARCH_HAS_USER_SHADOW_STACK 2229 select ARCH_USES_HIGH_VMA_FLAGS 2230 depends on !UPROBES 2231 help 2232 Guarded Control Stack (GCS) provides support for a separate 2233 stack with restricted access which contains only return 2234 addresses. This can be used to harden against some attacks 2235 by comparing return address used by the program with what is 2236 stored in the GCS, and may also be used to efficiently obtain 2237 the call stack for applications such as profiling. 2238 2239 The feature is detected at runtime, and will remain disabled 2240 if the system does not implement the feature. 2241 2242endmenu # "v9.4 architectural features" 2243 2244config ARM64_SVE 2245 bool "ARM Scalable Vector Extension support" 2246 default y 2247 help 2248 The Scalable Vector Extension (SVE) is an extension to the AArch64 2249 execution state which complements and extends the SIMD functionality 2250 of the base architecture to support much larger vectors and to enable 2251 additional vectorisation opportunities. 2252 2253 To enable use of this extension on CPUs that implement it, say Y. 2254 2255 On CPUs that support the SVE2 extensions, this option will enable 2256 those too. 2257 2258 Note that for architectural reasons, firmware _must_ implement SVE 2259 support when running on SVE capable hardware. The required support 2260 is present in: 2261 2262 * version 1.5 and later of the ARM Trusted Firmware 2263 * the AArch64 boot wrapper since commit 5e1261e08abf 2264 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2265 2266 For other firmware implementations, consult the firmware documentation 2267 or vendor. 2268 2269 If you need the kernel to boot on SVE-capable hardware with broken 2270 firmware, you may need to say N here until you get your firmware 2271 fixed. Otherwise, you may experience firmware panics or lockups when 2272 booting the kernel. If unsure and you are not observing these 2273 symptoms, you should assume that it is safe to say Y. 2274 2275config ARM64_SME 2276 bool "ARM Scalable Matrix Extension support" 2277 default y 2278 depends on ARM64_SVE 2279 help 2280 The Scalable Matrix Extension (SME) is an extension to the AArch64 2281 execution state which utilises a substantial subset of the SVE 2282 instruction set, together with the addition of new architectural 2283 register state capable of holding two dimensional matrix tiles to 2284 enable various matrix operations. 2285 2286config ARM64_PSEUDO_NMI 2287 bool "Support for NMI-like interrupts" 2288 select ARM_GIC_V3 2289 help 2290 Adds support for mimicking Non-Maskable Interrupts through the use of 2291 GIC interrupt priority. This support requires version 3 or later of 2292 ARM GIC. 2293 2294 This high priority configuration for interrupts needs to be 2295 explicitly enabled by setting the kernel parameter 2296 "irqchip.gicv3_pseudo_nmi" to 1. 2297 2298 If unsure, say N 2299 2300if ARM64_PSEUDO_NMI 2301config ARM64_DEBUG_PRIORITY_MASKING 2302 bool "Debug interrupt priority masking" 2303 help 2304 This adds runtime checks to functions enabling/disabling 2305 interrupts when using priority masking. The additional checks verify 2306 the validity of ICC_PMR_EL1 when calling concerned functions. 2307 2308 If unsure, say N 2309endif # ARM64_PSEUDO_NMI 2310 2311config RELOCATABLE 2312 bool "Build a relocatable kernel image" if EXPERT 2313 select ARCH_HAS_RELR 2314 default y 2315 help 2316 This builds the kernel as a Position Independent Executable (PIE), 2317 which retains all relocation metadata required to relocate the 2318 kernel binary at runtime to a different virtual address than the 2319 address it was linked at. 2320 Since AArch64 uses the RELA relocation format, this requires a 2321 relocation pass at runtime even if the kernel is loaded at the 2322 same address it was linked at. 2323 2324config RANDOMIZE_BASE 2325 bool "Randomize the address of the kernel image" 2326 select RELOCATABLE 2327 help 2328 Randomizes the virtual address at which the kernel image is 2329 loaded, as a security feature that deters exploit attempts 2330 relying on knowledge of the location of kernel internals. 2331 2332 It is the bootloader's job to provide entropy, by passing a 2333 random u64 value in /chosen/kaslr-seed at kernel entry. 2334 2335 When booting via the UEFI stub, it will invoke the firmware's 2336 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2337 to the kernel proper. In addition, it will randomise the physical 2338 location of the kernel Image as well. 2339 2340 If unsure, say N. 2341 2342config RANDOMIZE_MODULE_REGION_FULL 2343 bool "Randomize the module region over a 2 GB range" 2344 depends on RANDOMIZE_BASE 2345 default y 2346 help 2347 Randomizes the location of the module region inside a 2 GB window 2348 covering the core kernel. This way, it is less likely for modules 2349 to leak information about the location of core kernel data structures 2350 but it does imply that function calls between modules and the core 2351 kernel will need to be resolved via veneers in the module PLT. 2352 2353 When this option is not set, the module region will be randomized over 2354 a limited range that contains the [_stext, _etext] interval of the 2355 core kernel, so branch relocations are almost always in range unless 2356 the region is exhausted. In this particular case of region 2357 exhaustion, modules might be able to fall back to a larger 2GB area. 2358 2359config CC_HAVE_STACKPROTECTOR_SYSREG 2360 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2361 2362config STACKPROTECTOR_PER_TASK 2363 def_bool y 2364 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2365 2366config UNWIND_PATCH_PAC_INTO_SCS 2367 bool "Enable shadow call stack dynamically using code patching" 2368 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2369 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2370 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2371 depends on SHADOW_CALL_STACK 2372 select UNWIND_TABLES 2373 select DYNAMIC_SCS 2374 2375config ARM64_CONTPTE 2376 bool "Contiguous PTE mappings for user memory" if EXPERT 2377 depends on TRANSPARENT_HUGEPAGE 2378 default y 2379 help 2380 When enabled, user mappings are configured using the PTE contiguous 2381 bit, for any mappings that meet the size and alignment requirements. 2382 This reduces TLB pressure and improves performance. 2383 2384endmenu # "Kernel Features" 2385 2386menu "Boot options" 2387 2388config ARM64_ACPI_PARKING_PROTOCOL 2389 bool "Enable support for the ARM64 ACPI parking protocol" 2390 depends on ACPI 2391 help 2392 Enable support for the ARM64 ACPI parking protocol. If disabled 2393 the kernel will not allow booting through the ARM64 ACPI parking 2394 protocol even if the corresponding data is present in the ACPI 2395 MADT table. 2396 2397config CMDLINE 2398 string "Default kernel command string" 2399 default "" 2400 help 2401 Provide a set of default command-line options at build time by 2402 entering them here. As a minimum, you should specify the the 2403 root device (e.g. root=/dev/nfs). 2404 2405choice 2406 prompt "Kernel command line type" 2407 depends on CMDLINE != "" 2408 default CMDLINE_FROM_BOOTLOADER 2409 help 2410 Choose how the kernel will handle the provided default kernel 2411 command line string. 2412 2413config CMDLINE_FROM_BOOTLOADER 2414 bool "Use bootloader kernel arguments if available" 2415 help 2416 Uses the command-line options passed by the boot loader. If 2417 the boot loader doesn't provide any, the default kernel command 2418 string provided in CMDLINE will be used. 2419 2420config CMDLINE_FORCE 2421 bool "Always use the default kernel command string" 2422 help 2423 Always use the default kernel command string, even if the boot 2424 loader passes other arguments to the kernel. 2425 This is useful if you cannot or don't want to change the 2426 command-line options your boot loader passes to the kernel. 2427 2428endchoice 2429 2430config EFI_STUB 2431 bool 2432 2433config EFI 2434 bool "UEFI runtime support" 2435 depends on OF && !CPU_BIG_ENDIAN 2436 depends on KERNEL_MODE_NEON 2437 select ARCH_SUPPORTS_ACPI 2438 select LIBFDT 2439 select UCS2_STRING 2440 select EFI_PARAMS_FROM_FDT 2441 select EFI_RUNTIME_WRAPPERS 2442 select EFI_STUB 2443 select EFI_GENERIC_STUB 2444 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2445 default y 2446 help 2447 This option provides support for runtime services provided 2448 by UEFI firmware (such as non-volatile variables, realtime 2449 clock, and platform reset). A UEFI stub is also provided to 2450 allow the kernel to be booted as an EFI application. This 2451 is only useful on systems that have UEFI firmware. 2452 2453config COMPRESSED_INSTALL 2454 bool "Install compressed image by default" 2455 help 2456 This makes the regular "make install" install the compressed 2457 image we built, not the legacy uncompressed one. 2458 2459 You can check that a compressed image works for you by doing 2460 "make zinstall" first, and verifying that everything is fine 2461 in your environment before making "make install" do this for 2462 you. 2463 2464config DMI 2465 bool "Enable support for SMBIOS (DMI) tables" 2466 depends on EFI 2467 default y 2468 help 2469 This enables SMBIOS/DMI feature for systems. 2470 2471 This option is only useful on systems that have UEFI firmware. 2472 However, even with this option, the resultant kernel should 2473 continue to boot on existing non-UEFI platforms. 2474 2475endmenu # "Boot options" 2476 2477menu "Power management options" 2478 2479source "kernel/power/Kconfig" 2480 2481config ARCH_HIBERNATION_POSSIBLE 2482 def_bool y 2483 depends on CPU_PM 2484 2485config ARCH_HIBERNATION_HEADER 2486 def_bool y 2487 depends on HIBERNATION 2488 2489config ARCH_SUSPEND_POSSIBLE 2490 def_bool y 2491 2492endmenu # "Power management options" 2493 2494menu "CPU Power Management" 2495 2496source "drivers/cpuidle/Kconfig" 2497 2498source "drivers/cpufreq/Kconfig" 2499 2500endmenu # "CPU Power Management" 2501 2502source "drivers/acpi/Kconfig" 2503 2504source "arch/arm64/kvm/Kconfig" 2505 2506source "kernel/livepatch/Kconfig" 2507