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_CRC32 25 select ARCH_HAS_CRC_T10DIF if KERNEL_MODE_NEON 26 select ARCH_HAS_CURRENT_STACK_POINTER 27 select ARCH_HAS_DEBUG_VIRTUAL 28 select ARCH_HAS_DEBUG_VM_PGTABLE 29 select ARCH_HAS_DMA_OPS if XEN 30 select ARCH_HAS_DMA_PREP_COHERENT 31 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 32 select ARCH_HAS_FAST_MULTIPLIER 33 select ARCH_HAS_FORTIFY_SOURCE 34 select ARCH_HAS_GCOV_PROFILE_ALL 35 select ARCH_HAS_GIGANTIC_PAGE 36 select ARCH_HAS_KCOV 37 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 38 select ARCH_HAS_KEEPINITRD 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MEM_ENCRYPT 41 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 42 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 45 select ARCH_HAS_PREEMPT_LAZY 46 select ARCH_HAS_PTDUMP 47 select ARCH_HAS_PTE_DEVMAP 48 select ARCH_HAS_PTE_SPECIAL 49 select ARCH_HAS_HW_PTE_YOUNG 50 select ARCH_HAS_SETUP_DMA_OPS 51 select ARCH_HAS_SET_DIRECT_MAP 52 select ARCH_HAS_SET_MEMORY 53 select ARCH_HAS_MEM_ENCRYPT 54 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 55 select ARCH_STACKWALK 56 select ARCH_HAS_STRICT_KERNEL_RWX 57 select ARCH_HAS_STRICT_MODULE_RWX 58 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 59 select ARCH_HAS_SYNC_DMA_FOR_CPU 60 select ARCH_HAS_SYSCALL_WRAPPER 61 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 62 select ARCH_HAS_ZONE_DMA_SET if EXPERT 63 select ARCH_HAVE_ELF_PROT 64 select ARCH_HAVE_NMI_SAFE_CMPXCHG 65 select ARCH_HAVE_TRACE_MMIO_ACCESS 66 select ARCH_INLINE_READ_LOCK if !PREEMPTION 67 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 68 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 69 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 71 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 72 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 73 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 75 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 76 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 77 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 79 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 80 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 81 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 82 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 83 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 85 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 86 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 87 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 89 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 90 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 91 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 92 select ARCH_KEEP_MEMBLOCK 93 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 94 select ARCH_USE_CMPXCHG_LOCKREF 95 select ARCH_USE_GNU_PROPERTY 96 select ARCH_USE_MEMTEST 97 select ARCH_USE_QUEUED_RWLOCKS 98 select ARCH_USE_QUEUED_SPINLOCKS 99 select ARCH_USE_SYM_ANNOTATIONS 100 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 101 select ARCH_SUPPORTS_HUGETLBFS 102 select ARCH_SUPPORTS_MEMORY_FAILURE 103 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 104 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 105 select ARCH_SUPPORTS_LTO_CLANG_THIN 106 select ARCH_SUPPORTS_CFI_CLANG 107 select ARCH_SUPPORTS_ATOMIC_RMW 108 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 109 select ARCH_SUPPORTS_NUMA_BALANCING 110 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 111 select ARCH_SUPPORTS_PER_VMA_LOCK 112 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 113 select ARCH_SUPPORTS_RT 114 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 115 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 116 select ARCH_WANT_DEFAULT_BPF_JIT 117 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 118 select ARCH_WANT_FRAME_POINTERS 119 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 120 select ARCH_WANT_LD_ORPHAN_WARN 121 select ARCH_WANTS_EXECMEM_LATE 122 select ARCH_WANTS_NO_INSTR 123 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 124 select ARCH_HAS_UBSAN 125 select ARM_AMBA 126 select ARM_ARCH_TIMER 127 select ARM_GIC 128 select AUDIT_ARCH_COMPAT_GENERIC 129 select ARM_GIC_V2M if PCI 130 select ARM_GIC_V3 131 select ARM_GIC_V3_ITS if PCI 132 select ARM_PSCI_FW 133 select BUILDTIME_TABLE_SORT 134 select CLONE_BACKWARDS 135 select COMMON_CLK 136 select CPU_PM if (SUSPEND || CPU_IDLE) 137 select CPUMASK_OFFSTACK if NR_CPUS > 256 138 select DCACHE_WORD_ACCESS 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_DEVICES 151 select GENERIC_CPU_VULNERABILITIES 152 select GENERIC_EARLY_IOREMAP 153 select GENERIC_IDLE_POLL_SETUP 154 select GENERIC_IOREMAP 155 select GENERIC_IRQ_IPI 156 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 157 select GENERIC_IRQ_PROBE 158 select GENERIC_IRQ_SHOW 159 select GENERIC_IRQ_SHOW_LEVEL 160 select GENERIC_LIB_DEVMEM_IS_ALLOWED 161 select GENERIC_PCI_IOMAP 162 select GENERIC_SCHED_CLOCK 163 select GENERIC_SMP_IDLE_THREAD 164 select GENERIC_TIME_VSYSCALL 165 select GENERIC_GETTIMEOFDAY 166 select GENERIC_VDSO_DATA_STORE 167 select GENERIC_VDSO_TIME_NS 168 select HARDIRQS_SW_RESEND 169 select HAS_IOPORT 170 select HAVE_MOVE_PMD 171 select HAVE_MOVE_PUD 172 select HAVE_PCI 173 select HAVE_ACPI_APEI if (ACPI && EFI) 174 select HAVE_ALIGNED_STRUCT_PAGE 175 select HAVE_ARCH_AUDITSYSCALL 176 select HAVE_ARCH_BITREVERSE 177 select HAVE_ARCH_COMPILER_H 178 select HAVE_ARCH_HUGE_VMALLOC 179 select HAVE_ARCH_HUGE_VMAP 180 select HAVE_ARCH_JUMP_LABEL 181 select HAVE_ARCH_JUMP_LABEL_RELATIVE 182 select HAVE_ARCH_KASAN 183 select HAVE_ARCH_KASAN_VMALLOC 184 select HAVE_ARCH_KASAN_SW_TAGS 185 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 186 # Some instrumentation may be unsound, hence EXPERT 187 select HAVE_ARCH_KCSAN if EXPERT 188 select HAVE_ARCH_KFENCE 189 select HAVE_ARCH_KGDB 190 select HAVE_ARCH_MMAP_RND_BITS 191 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 192 select HAVE_ARCH_PREL32_RELOCATIONS 193 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 194 select HAVE_ARCH_SECCOMP_FILTER 195 select HAVE_ARCH_STACKLEAK 196 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 197 select HAVE_ARCH_TRACEHOOK 198 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 199 select HAVE_ARCH_VMAP_STACK 200 select HAVE_ARM_SMCCC 201 select HAVE_ASM_MODVERSIONS 202 select HAVE_EBPF_JIT 203 select HAVE_C_RECORDMCOUNT 204 select HAVE_CMPXCHG_DOUBLE 205 select HAVE_CMPXCHG_LOCAL 206 select HAVE_CONTEXT_TRACKING_USER 207 select HAVE_DEBUG_KMEMLEAK 208 select HAVE_DMA_CONTIGUOUS 209 select HAVE_DYNAMIC_FTRACE 210 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 211 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 212 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 213 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 214 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 215 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 216 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 217 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 218 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 219 if DYNAMIC_FTRACE_WITH_ARGS 220 select HAVE_SAMPLE_FTRACE_DIRECT 221 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 222 select HAVE_BUILDTIME_MCOUNT_SORT 223 select HAVE_EFFICIENT_UNALIGNED_ACCESS 224 select HAVE_GUP_FAST 225 select HAVE_FTRACE_GRAPH_FUNC 226 select HAVE_FTRACE_MCOUNT_RECORD 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 KASAN_VMALLOC if KASAN 262 select LOCK_MM_AND_FIND_VMA 263 select MODULES_USE_ELF_RELA 264 select NEED_DMA_MAP_STATE 265 select NEED_SG_DMA_LENGTH 266 select OF 267 select OF_EARLY_FLATTREE 268 select PCI_DOMAINS_GENERIC if PCI 269 select PCI_ECAM if (ACPI && PCI) 270 select PCI_SYSCALL if PCI 271 select POWER_RESET 272 select POWER_SUPPLY 273 select SPARSE_IRQ 274 select SWIOTLB 275 select SYSCTL_EXCEPTION_TRACE 276 select THREAD_INFO_IN_TASK 277 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 278 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 279 select TRACE_IRQFLAGS_SUPPORT 280 select TRACE_IRQFLAGS_NMI_SUPPORT 281 select HAVE_SOFTIRQ_ON_OWN_STACK 282 select USER_STACKTRACE_SUPPORT 283 select VDSO_GETRANDOM 284 select VMAP_STACK 285 help 286 ARM 64-bit (AArch64) Linux support. 287 288config RUSTC_SUPPORTS_ARM64 289 def_bool y 290 depends on CPU_LITTLE_ENDIAN 291 # Shadow call stack is only supported on certain rustc versions. 292 # 293 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 294 # required due to use of the -Zfixed-x18 flag. 295 # 296 # Otherwise, rustc version 1.82+ is required due to use of the 297 # -Zsanitizer=shadow-call-stack flag. 298 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 299 300config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 301 def_bool CC_IS_CLANG 302 # https://github.com/ClangBuiltLinux/linux/issues/1507 303 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 304 305config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 306 def_bool CC_IS_GCC 307 depends on $(cc-option,-fpatchable-function-entry=2) 308 309config 64BIT 310 def_bool y 311 312config MMU 313 def_bool y 314 315config ARM64_CONT_PTE_SHIFT 316 int 317 default 5 if PAGE_SIZE_64KB 318 default 7 if PAGE_SIZE_16KB 319 default 4 320 321config ARM64_CONT_PMD_SHIFT 322 int 323 default 5 if PAGE_SIZE_64KB 324 default 5 if PAGE_SIZE_16KB 325 default 4 326 327config ARCH_MMAP_RND_BITS_MIN 328 default 14 if PAGE_SIZE_64KB 329 default 16 if PAGE_SIZE_16KB 330 default 18 331 332# max bits determined by the following formula: 333# VA_BITS - PTDESC_TABLE_SHIFT 334config ARCH_MMAP_RND_BITS_MAX 335 default 19 if ARM64_VA_BITS=36 336 default 24 if ARM64_VA_BITS=39 337 default 27 if ARM64_VA_BITS=42 338 default 30 if ARM64_VA_BITS=47 339 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 340 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 341 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 342 default 14 if ARM64_64K_PAGES 343 default 16 if ARM64_16K_PAGES 344 default 18 345 346config ARCH_MMAP_RND_COMPAT_BITS_MIN 347 default 7 if ARM64_64K_PAGES 348 default 9 if ARM64_16K_PAGES 349 default 11 350 351config ARCH_MMAP_RND_COMPAT_BITS_MAX 352 default 16 353 354config NO_IOPORT_MAP 355 def_bool y if !PCI 356 357config STACKTRACE_SUPPORT 358 def_bool y 359 360config ILLEGAL_POINTER_VALUE 361 hex 362 default 0xdead000000000000 363 364config LOCKDEP_SUPPORT 365 def_bool y 366 367config GENERIC_BUG 368 def_bool y 369 depends on BUG 370 371config GENERIC_BUG_RELATIVE_POINTERS 372 def_bool y 373 depends on GENERIC_BUG 374 375config GENERIC_HWEIGHT 376 def_bool y 377 378config GENERIC_CSUM 379 def_bool y 380 381config GENERIC_CALIBRATE_DELAY 382 def_bool y 383 384config SMP 385 def_bool y 386 387config KERNEL_MODE_NEON 388 def_bool y 389 390config FIX_EARLYCON_MEM 391 def_bool y 392 393config PGTABLE_LEVELS 394 int 395 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 396 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 397 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 398 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 399 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 400 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 401 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 402 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 403 404config ARCH_SUPPORTS_UPROBES 405 def_bool y 406 407config ARCH_PROC_KCORE_TEXT 408 def_bool y 409 410config BROKEN_GAS_INST 411 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 412 413config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 414 bool 415 # Clang's __builtin_return_address() strips the PAC since 12.0.0 416 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 417 default y if CC_IS_CLANG 418 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 419 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 420 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 421 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 422 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 423 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 424 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 425 default n 426 427config KASAN_SHADOW_OFFSET 428 hex 429 depends on KASAN_GENERIC || KASAN_SW_TAGS 430 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 431 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 432 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 433 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 434 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 435 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 436 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 437 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 438 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 439 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 440 default 0xffffffffffffffff 441 442config UNWIND_TABLES 443 bool 444 445source "arch/arm64/Kconfig.platforms" 446 447menu "Kernel Features" 448 449menu "ARM errata workarounds via the alternatives framework" 450 451config AMPERE_ERRATUM_AC03_CPU_38 452 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 453 default y 454 help 455 This option adds an alternative code sequence to work around Ampere 456 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 457 458 The affected design reports FEAT_HAFDBS as not implemented in 459 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 460 as required by the architecture. The unadvertised HAFDBS 461 implementation suffers from an additional erratum where hardware 462 A/D updates can occur after a PTE has been marked invalid. 463 464 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 465 which avoids enabling unadvertised hardware Access Flag management 466 at stage-2. 467 468 If unsure, say Y. 469 470config AMPERE_ERRATUM_AC04_CPU_23 471 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 472 default y 473 help 474 This option adds an alternative code sequence to work around Ampere 475 errata AC04_CPU_23 on AmpereOne. 476 477 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 478 data addresses initiated by load/store instructions. Only 479 instruction initiated translations are vulnerable, not translations 480 from prefetches for example. A DSB before the store to HCR_EL2 is 481 sufficient to prevent older instructions from hitting the window 482 for corruption, and an ISB after is sufficient to prevent younger 483 instructions from hitting the window for corruption. 484 485 If unsure, say Y. 486 487config ARM64_WORKAROUND_CLEAN_CACHE 488 bool 489 490config ARM64_ERRATUM_826319 491 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 492 default y 493 select ARM64_WORKAROUND_CLEAN_CACHE 494 help 495 This option adds an alternative code sequence to work around ARM 496 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 497 AXI master interface and an L2 cache. 498 499 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 500 and is unable to accept a certain write via this interface, it will 501 not progress on read data presented on the read data channel and the 502 system can deadlock. 503 504 The workaround promotes data cache clean instructions to 505 data cache clean-and-invalidate. 506 Please note that this does not necessarily enable the workaround, 507 as it depends on the alternative framework, which will only patch 508 the kernel if an affected CPU is detected. 509 510 If unsure, say Y. 511 512config ARM64_ERRATUM_827319 513 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 514 default y 515 select ARM64_WORKAROUND_CLEAN_CACHE 516 help 517 This option adds an alternative code sequence to work around ARM 518 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 519 master interface and an L2 cache. 520 521 Under certain conditions this erratum can cause a clean line eviction 522 to occur at the same time as another transaction to the same address 523 on the AMBA 5 CHI interface, which can cause data corruption if the 524 interconnect reorders the two transactions. 525 526 The workaround promotes data cache clean instructions to 527 data cache clean-and-invalidate. 528 Please note that this does not necessarily enable the workaround, 529 as it depends on the alternative framework, which will only patch 530 the kernel if an affected CPU is detected. 531 532 If unsure, say Y. 533 534config ARM64_ERRATUM_824069 535 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 536 default y 537 select ARM64_WORKAROUND_CLEAN_CACHE 538 help 539 This option adds an alternative code sequence to work around ARM 540 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 541 to a coherent interconnect. 542 543 If a Cortex-A53 processor is executing a store or prefetch for 544 write instruction at the same time as a processor in another 545 cluster is executing a cache maintenance operation to the same 546 address, then this erratum might cause a clean cache line to be 547 incorrectly marked as dirty. 548 549 The workaround promotes data cache clean instructions to 550 data cache clean-and-invalidate. 551 Please note that this option does not necessarily enable the 552 workaround, as it depends on the alternative framework, which will 553 only patch the kernel if an affected CPU is detected. 554 555 If unsure, say Y. 556 557config ARM64_ERRATUM_819472 558 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 559 default y 560 select ARM64_WORKAROUND_CLEAN_CACHE 561 help 562 This option adds an alternative code sequence to work around ARM 563 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 564 present when it is connected to a coherent interconnect. 565 566 If the processor is executing a load and store exclusive sequence at 567 the same time as a processor in another cluster is executing a cache 568 maintenance operation to the same address, then this erratum might 569 cause data corruption. 570 571 The workaround promotes data cache clean instructions to 572 data cache clean-and-invalidate. 573 Please note that this does not necessarily enable the workaround, 574 as it depends on the alternative framework, which will only patch 575 the kernel if an affected CPU is detected. 576 577 If unsure, say Y. 578 579config ARM64_ERRATUM_832075 580 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 581 default y 582 help 583 This option adds an alternative code sequence to work around ARM 584 erratum 832075 on Cortex-A57 parts up to r1p2. 585 586 Affected Cortex-A57 parts might deadlock when exclusive load/store 587 instructions to Write-Back memory are mixed with Device loads. 588 589 The workaround is to promote device loads to use Load-Acquire 590 semantics. 591 Please note that this does not necessarily enable the workaround, 592 as it depends on the alternative framework, which will only patch 593 the kernel if an affected CPU is detected. 594 595 If unsure, say Y. 596 597config ARM64_ERRATUM_834220 598 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 599 depends on KVM 600 help 601 This option adds an alternative code sequence to work around ARM 602 erratum 834220 on Cortex-A57 parts up to r1p2. 603 604 Affected Cortex-A57 parts might report a Stage 2 translation 605 fault as the result of a Stage 1 fault for load crossing a 606 page boundary when there is a permission or device memory 607 alignment fault at Stage 1 and a translation fault at Stage 2. 608 609 The workaround is to verify that the Stage 1 translation 610 doesn't generate a fault before handling the Stage 2 fault. 611 Please note that this does not necessarily enable the workaround, 612 as it depends on the alternative framework, which will only patch 613 the kernel if an affected CPU is detected. 614 615 If unsure, say N. 616 617config ARM64_ERRATUM_1742098 618 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 619 depends on COMPAT 620 default y 621 help 622 This option removes the AES hwcap for aarch32 user-space to 623 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 624 625 Affected parts may corrupt the AES state if an interrupt is 626 taken between a pair of AES instructions. These instructions 627 are only present if the cryptography extensions are present. 628 All software should have a fallback implementation for CPUs 629 that don't implement the cryptography extensions. 630 631 If unsure, say Y. 632 633config ARM64_ERRATUM_845719 634 bool "Cortex-A53: 845719: a load might read incorrect data" 635 depends on COMPAT 636 default y 637 help 638 This option adds an alternative code sequence to work around ARM 639 erratum 845719 on Cortex-A53 parts up to r0p4. 640 641 When running a compat (AArch32) userspace on an affected Cortex-A53 642 part, a load at EL0 from a virtual address that matches the bottom 32 643 bits of the virtual address used by a recent load at (AArch64) EL1 644 might return incorrect data. 645 646 The workaround is to write the contextidr_el1 register on exception 647 return to a 32-bit task. 648 Please note that this does not necessarily enable the workaround, 649 as it depends on the alternative framework, which will only patch 650 the kernel if an affected CPU is detected. 651 652 If unsure, say Y. 653 654config ARM64_ERRATUM_843419 655 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 656 default y 657 help 658 This option links the kernel with '--fix-cortex-a53-843419' and 659 enables PLT support to replace certain ADRP instructions, which can 660 cause subsequent memory accesses to use an incorrect address on 661 Cortex-A53 parts up to r0p4. 662 663 If unsure, say Y. 664 665config ARM64_ERRATUM_1024718 666 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 667 default y 668 help 669 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 670 671 Affected Cortex-A55 cores (all revisions) could cause incorrect 672 update of the hardware dirty bit when the DBM/AP bits are updated 673 without a break-before-make. The workaround is to disable the usage 674 of hardware DBM locally on the affected cores. CPUs not affected by 675 this erratum will continue to use the feature. 676 677 If unsure, say Y. 678 679config ARM64_ERRATUM_1418040 680 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 681 default y 682 depends on COMPAT 683 help 684 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 685 errata 1188873 and 1418040. 686 687 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 688 cause register corruption when accessing the timer registers 689 from AArch32 userspace. 690 691 If unsure, say Y. 692 693config ARM64_WORKAROUND_SPECULATIVE_AT 694 bool 695 696config ARM64_ERRATUM_1165522 697 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 698 default y 699 select ARM64_WORKAROUND_SPECULATIVE_AT 700 help 701 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 702 703 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 704 corrupted TLBs by speculating an AT instruction during a guest 705 context switch. 706 707 If unsure, say Y. 708 709config ARM64_ERRATUM_1319367 710 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 711 default y 712 select ARM64_WORKAROUND_SPECULATIVE_AT 713 help 714 This option adds work arounds for ARM Cortex-A57 erratum 1319537 715 and A72 erratum 1319367 716 717 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 718 speculating an AT instruction during a guest context switch. 719 720 If unsure, say Y. 721 722config ARM64_ERRATUM_1530923 723 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 724 default y 725 select ARM64_WORKAROUND_SPECULATIVE_AT 726 help 727 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 728 729 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 730 corrupted TLBs by speculating an AT instruction during a guest 731 context switch. 732 733 If unsure, say Y. 734 735config ARM64_WORKAROUND_REPEAT_TLBI 736 bool 737 738config ARM64_ERRATUM_2441007 739 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 740 select ARM64_WORKAROUND_REPEAT_TLBI 741 help 742 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 743 744 Under very rare circumstances, affected Cortex-A55 CPUs 745 may not handle a race between a break-before-make sequence on one 746 CPU, and another CPU accessing the same page. This could allow a 747 store to a page that has been unmapped. 748 749 Work around this by adding the affected CPUs to the list that needs 750 TLB sequences to be done twice. 751 752 If unsure, say N. 753 754config ARM64_ERRATUM_1286807 755 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 756 select ARM64_WORKAROUND_REPEAT_TLBI 757 help 758 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 759 760 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 761 address for a cacheable mapping of a location is being 762 accessed by a core while another core is remapping the virtual 763 address to a new physical page using the recommended 764 break-before-make sequence, then under very rare circumstances 765 TLBI+DSB completes before a read using the translation being 766 invalidated has been observed by other observers. The 767 workaround repeats the TLBI+DSB operation. 768 769 If unsure, say N. 770 771config ARM64_ERRATUM_1463225 772 bool "Cortex-A76: Software Step might prevent interrupt recognition" 773 default y 774 help 775 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 776 777 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 778 of a system call instruction (SVC) can prevent recognition of 779 subsequent interrupts when software stepping is disabled in the 780 exception handler of the system call and either kernel debugging 781 is enabled or VHE is in use. 782 783 Work around the erratum by triggering a dummy step exception 784 when handling a system call from a task that is being stepped 785 in a VHE configuration of the kernel. 786 787 If unsure, say Y. 788 789config ARM64_ERRATUM_1542419 790 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 791 help 792 This option adds a workaround for ARM Neoverse-N1 erratum 793 1542419. 794 795 Affected Neoverse-N1 cores could execute a stale instruction when 796 modified by another CPU. The workaround depends on a firmware 797 counterpart. 798 799 Workaround the issue by hiding the DIC feature from EL0. This 800 forces user-space to perform cache maintenance. 801 802 If unsure, say N. 803 804config ARM64_ERRATUM_1508412 805 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 806 default y 807 help 808 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 809 810 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 811 of a store-exclusive or read of PAR_EL1 and a load with device or 812 non-cacheable memory attributes. The workaround depends on a firmware 813 counterpart. 814 815 KVM guests must also have the workaround implemented or they can 816 deadlock the system. 817 818 Work around the issue by inserting DMB SY barriers around PAR_EL1 819 register reads and warning KVM users. The DMB barrier is sufficient 820 to prevent a speculative PAR_EL1 read. 821 822 If unsure, say Y. 823 824config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 825 bool 826 827config ARM64_ERRATUM_2051678 828 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 829 default y 830 help 831 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 832 Affected Cortex-A510 might not respect the ordering rules for 833 hardware update of the page table's dirty bit. The workaround 834 is to not enable the feature on affected CPUs. 835 836 If unsure, say Y. 837 838config ARM64_ERRATUM_2077057 839 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 840 default y 841 help 842 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 843 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 844 expected, but a Pointer Authentication trap is taken instead. The 845 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 846 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 847 848 This can only happen when EL2 is stepping EL1. 849 850 When these conditions occur, the SPSR_EL2 value is unchanged from the 851 previous guest entry, and can be restored from the in-memory copy. 852 853 If unsure, say Y. 854 855config ARM64_ERRATUM_2658417 856 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 857 default y 858 help 859 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 860 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 861 BFMMLA or VMMLA instructions in rare circumstances when a pair of 862 A510 CPUs are using shared neon hardware. As the sharing is not 863 discoverable by the kernel, hide the BF16 HWCAP to indicate that 864 user-space should not be using these instructions. 865 866 If unsure, say Y. 867 868config ARM64_ERRATUM_2119858 869 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 870 default y 871 depends on CORESIGHT_TRBE 872 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 873 help 874 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 875 876 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 877 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 878 the event of a WRAP event. 879 880 Work around the issue by always making sure we move the TRBPTR_EL1 by 881 256 bytes before enabling the buffer and filling the first 256 bytes of 882 the buffer with ETM ignore packets upon disabling. 883 884 If unsure, say Y. 885 886config ARM64_ERRATUM_2139208 887 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 888 default y 889 depends on CORESIGHT_TRBE 890 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 891 help 892 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 893 894 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 895 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 896 the event of a WRAP event. 897 898 Work around the issue by always making sure we move the TRBPTR_EL1 by 899 256 bytes before enabling the buffer and filling the first 256 bytes of 900 the buffer with ETM ignore packets upon disabling. 901 902 If unsure, say Y. 903 904config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 905 bool 906 907config ARM64_ERRATUM_2054223 908 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 909 default y 910 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 911 help 912 Enable workaround for ARM Cortex-A710 erratum 2054223 913 914 Affected cores may fail to flush the trace data on a TSB instruction, when 915 the PE is in trace prohibited state. This will cause losing a few bytes 916 of the trace cached. 917 918 Workaround is to issue two TSB consecutively on affected cores. 919 920 If unsure, say Y. 921 922config ARM64_ERRATUM_2067961 923 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 924 default y 925 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 926 help 927 Enable workaround for ARM Neoverse-N2 erratum 2067961 928 929 Affected cores may fail to flush the trace data on a TSB instruction, when 930 the PE is in trace prohibited state. This will cause losing a few bytes 931 of the trace cached. 932 933 Workaround is to issue two TSB consecutively on affected cores. 934 935 If unsure, say Y. 936 937config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 938 bool 939 940config ARM64_ERRATUM_2253138 941 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 942 depends on CORESIGHT_TRBE 943 default y 944 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 945 help 946 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 947 948 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 949 for TRBE. Under some conditions, the TRBE might generate a write to the next 950 virtually addressed page following the last page of the TRBE address space 951 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 952 953 Work around this in the driver by always making sure that there is a 954 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 955 956 If unsure, say Y. 957 958config ARM64_ERRATUM_2224489 959 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 960 depends on CORESIGHT_TRBE 961 default y 962 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 963 help 964 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 965 966 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 967 for TRBE. Under some conditions, the TRBE might generate a write to the next 968 virtually addressed page following the last page of the TRBE address space 969 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 970 971 Work around this in the driver by always making sure that there is a 972 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 973 974 If unsure, say Y. 975 976config ARM64_ERRATUM_2441009 977 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 978 select ARM64_WORKAROUND_REPEAT_TLBI 979 help 980 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 981 982 Under very rare circumstances, affected Cortex-A510 CPUs 983 may not handle a race between a break-before-make sequence on one 984 CPU, and another CPU accessing the same page. This could allow a 985 store to a page that has been unmapped. 986 987 Work around this by adding the affected CPUs to the list that needs 988 TLB sequences to be done twice. 989 990 If unsure, say N. 991 992config ARM64_ERRATUM_2064142 993 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 994 depends on CORESIGHT_TRBE 995 default y 996 help 997 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 998 999 Affected Cortex-A510 core might fail to write into system registers after the 1000 TRBE has been disabled. Under some conditions after the TRBE has been disabled 1001 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 1002 and TRBTRG_EL1 will be ignored and will not be effected. 1003 1004 Work around this in the driver by executing TSB CSYNC and DSB after collection 1005 is stopped and before performing a system register write to one of the affected 1006 registers. 1007 1008 If unsure, say Y. 1009 1010config ARM64_ERRATUM_2038923 1011 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1012 depends on CORESIGHT_TRBE 1013 default y 1014 help 1015 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1016 1017 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1018 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1019 might be corrupted. This happens after TRBE buffer has been enabled by setting 1020 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1021 execution changes from a context, in which trace is prohibited to one where it 1022 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1023 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1024 the trace buffer state might be corrupted. 1025 1026 Work around this in the driver by preventing an inconsistent view of whether the 1027 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1028 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1029 two ISB instructions if no ERET is to take place. 1030 1031 If unsure, say Y. 1032 1033config ARM64_ERRATUM_1902691 1034 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1035 depends on CORESIGHT_TRBE 1036 default y 1037 help 1038 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1039 1040 Affected Cortex-A510 core might cause trace data corruption, when being written 1041 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1042 trace data. 1043 1044 Work around this problem in the driver by just preventing TRBE initialization on 1045 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1046 on such implementations. This will cover the kernel for any firmware that doesn't 1047 do this already. 1048 1049 If unsure, say Y. 1050 1051config ARM64_ERRATUM_2457168 1052 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1053 depends on ARM64_AMU_EXTN 1054 default y 1055 help 1056 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1057 1058 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1059 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1060 incorrectly giving a significantly higher output value. 1061 1062 Work around this problem by returning 0 when reading the affected counter in 1063 key locations that results in disabling all users of this counter. This effect 1064 is the same to firmware disabling affected counters. 1065 1066 If unsure, say Y. 1067 1068config ARM64_ERRATUM_2645198 1069 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1070 default y 1071 help 1072 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1073 1074 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1075 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1076 next instruction abort caused by permission fault. 1077 1078 Only user-space does executable to non-executable permission transition via 1079 mprotect() system call. Workaround the problem by doing a break-before-make 1080 TLB invalidation, for all changes to executable user space mappings. 1081 1082 If unsure, say Y. 1083 1084config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1085 bool 1086 1087config ARM64_ERRATUM_2966298 1088 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1089 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1090 default y 1091 help 1092 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1093 1094 On an affected Cortex-A520 core, a speculatively executed unprivileged 1095 load might leak data from a privileged level via a cache side channel. 1096 1097 Work around this problem by executing a TLBI before returning to EL0. 1098 1099 If unsure, say Y. 1100 1101config ARM64_ERRATUM_3117295 1102 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1103 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1104 default y 1105 help 1106 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1107 1108 On an affected Cortex-A510 core, a speculatively executed unprivileged 1109 load might leak data from a privileged level via a cache side channel. 1110 1111 Work around this problem by executing a TLBI before returning to EL0. 1112 1113 If unsure, say Y. 1114 1115config ARM64_ERRATUM_3194386 1116 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1117 default y 1118 help 1119 This option adds the workaround for the following errata: 1120 1121 * ARM Cortex-A76 erratum 3324349 1122 * ARM Cortex-A77 erratum 3324348 1123 * ARM Cortex-A78 erratum 3324344 1124 * ARM Cortex-A78C erratum 3324346 1125 * ARM Cortex-A78C erratum 3324347 1126 * ARM Cortex-A710 erratam 3324338 1127 * ARM Cortex-A715 errartum 3456084 1128 * ARM Cortex-A720 erratum 3456091 1129 * ARM Cortex-A725 erratum 3456106 1130 * ARM Cortex-X1 erratum 3324344 1131 * ARM Cortex-X1C erratum 3324346 1132 * ARM Cortex-X2 erratum 3324338 1133 * ARM Cortex-X3 erratum 3324335 1134 * ARM Cortex-X4 erratum 3194386 1135 * ARM Cortex-X925 erratum 3324334 1136 * ARM Neoverse-N1 erratum 3324349 1137 * ARM Neoverse N2 erratum 3324339 1138 * ARM Neoverse-N3 erratum 3456111 1139 * ARM Neoverse-V1 erratum 3324341 1140 * ARM Neoverse V2 erratum 3324336 1141 * ARM Neoverse-V3 erratum 3312417 1142 1143 On affected cores "MSR SSBS, #0" instructions may not affect 1144 subsequent speculative instructions, which may permit unexepected 1145 speculative store bypassing. 1146 1147 Work around this problem by placing a Speculation Barrier (SB) or 1148 Instruction Synchronization Barrier (ISB) after kernel changes to 1149 SSBS. The presence of the SSBS special-purpose register is hidden 1150 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1151 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1152 1153 If unsure, say Y. 1154 1155config CAVIUM_ERRATUM_22375 1156 bool "Cavium erratum 22375, 24313" 1157 default y 1158 help 1159 Enable workaround for errata 22375 and 24313. 1160 1161 This implements two gicv3-its errata workarounds for ThunderX. Both 1162 with a small impact affecting only ITS table allocation. 1163 1164 erratum 22375: only alloc 8MB table size 1165 erratum 24313: ignore memory access type 1166 1167 The fixes are in ITS initialization and basically ignore memory access 1168 type and table size provided by the TYPER and BASER registers. 1169 1170 If unsure, say Y. 1171 1172config CAVIUM_ERRATUM_23144 1173 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1174 depends on NUMA 1175 default y 1176 help 1177 ITS SYNC command hang for cross node io and collections/cpu mapping. 1178 1179 If unsure, say Y. 1180 1181config CAVIUM_ERRATUM_23154 1182 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1183 default y 1184 help 1185 The ThunderX GICv3 implementation requires a modified version for 1186 reading the IAR status to ensure data synchronization 1187 (access to icc_iar1_el1 is not sync'ed before and after). 1188 1189 It also suffers from erratum 38545 (also present on Marvell's 1190 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1191 spuriously presented to the CPU interface. 1192 1193 If unsure, say Y. 1194 1195config CAVIUM_ERRATUM_27456 1196 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1197 default y 1198 help 1199 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1200 instructions may cause the icache to become corrupted if it 1201 contains data for a non-current ASID. The fix is to 1202 invalidate the icache when changing the mm context. 1203 1204 If unsure, say Y. 1205 1206config CAVIUM_ERRATUM_30115 1207 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1208 default y 1209 help 1210 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1211 1.2, and T83 Pass 1.0, KVM guest execution may disable 1212 interrupts in host. Trapping both GICv3 group-0 and group-1 1213 accesses sidesteps the issue. 1214 1215 If unsure, say Y. 1216 1217config CAVIUM_TX2_ERRATUM_219 1218 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1219 default y 1220 help 1221 On Cavium ThunderX2, a load, store or prefetch instruction between a 1222 TTBR update and the corresponding context synchronizing operation can 1223 cause a spurious Data Abort to be delivered to any hardware thread in 1224 the CPU core. 1225 1226 Work around the issue by avoiding the problematic code sequence and 1227 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1228 trap handler performs the corresponding register access, skips the 1229 instruction and ensures context synchronization by virtue of the 1230 exception return. 1231 1232 If unsure, say Y. 1233 1234config FUJITSU_ERRATUM_010001 1235 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1236 default y 1237 help 1238 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1239 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1240 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1241 This fault occurs under a specific hardware condition when a 1242 load/store instruction performs an address translation using: 1243 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1244 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1245 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1246 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1247 1248 The workaround is to ensure these bits are clear in TCR_ELx. 1249 The workaround only affects the Fujitsu-A64FX. 1250 1251 If unsure, say Y. 1252 1253config HISILICON_ERRATUM_161600802 1254 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1255 default y 1256 help 1257 The HiSilicon Hip07 SoC uses the wrong redistributor base 1258 when issued ITS commands such as VMOVP and VMAPP, and requires 1259 a 128kB offset to be applied to the target address in this commands. 1260 1261 If unsure, say Y. 1262 1263config HISILICON_ERRATUM_162100801 1264 bool "Hip09 162100801 erratum support" 1265 default y 1266 help 1267 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1268 during unmapping operation, which will cause some vSGIs lost. 1269 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1270 after VMOVP. 1271 1272 If unsure, say Y. 1273 1274config QCOM_FALKOR_ERRATUM_1003 1275 bool "Falkor E1003: Incorrect translation due to ASID change" 1276 default y 1277 help 1278 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1279 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1280 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1281 then only for entries in the walk cache, since the leaf translation 1282 is unchanged. Work around the erratum by invalidating the walk cache 1283 entries for the trampoline before entering the kernel proper. 1284 1285config QCOM_FALKOR_ERRATUM_1009 1286 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1287 default y 1288 select ARM64_WORKAROUND_REPEAT_TLBI 1289 help 1290 On Falkor v1, the CPU may prematurely complete a DSB following a 1291 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1292 one more time to fix the issue. 1293 1294 If unsure, say Y. 1295 1296config QCOM_QDF2400_ERRATUM_0065 1297 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1298 default y 1299 help 1300 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1301 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1302 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1303 1304 If unsure, say Y. 1305 1306config QCOM_FALKOR_ERRATUM_E1041 1307 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1308 default y 1309 help 1310 Falkor CPU may speculatively fetch instructions from an improper 1311 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1312 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1313 1314 If unsure, say Y. 1315 1316config NVIDIA_CARMEL_CNP_ERRATUM 1317 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1318 default y 1319 help 1320 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1321 invalidate shared TLB entries installed by a different core, as it would 1322 on standard ARM cores. 1323 1324 If unsure, say Y. 1325 1326config ROCKCHIP_ERRATUM_3568002 1327 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1328 default y 1329 help 1330 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1331 addressing limited to the first 32bit of physical address space. 1332 1333 If unsure, say Y. 1334 1335config ROCKCHIP_ERRATUM_3588001 1336 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1337 default y 1338 help 1339 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1340 This means, that its sharability feature may not be used, even though it 1341 is supported by the IP itself. 1342 1343 If unsure, say Y. 1344 1345config SOCIONEXT_SYNQUACER_PREITS 1346 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1347 default y 1348 help 1349 Socionext Synquacer SoCs implement a separate h/w block to generate 1350 MSI doorbell writes with non-zero values for the device ID. 1351 1352 If unsure, say Y. 1353 1354endmenu # "ARM errata workarounds via the alternatives framework" 1355 1356choice 1357 prompt "Page size" 1358 default ARM64_4K_PAGES 1359 help 1360 Page size (translation granule) configuration. 1361 1362config ARM64_4K_PAGES 1363 bool "4KB" 1364 select HAVE_PAGE_SIZE_4KB 1365 help 1366 This feature enables 4KB pages support. 1367 1368config ARM64_16K_PAGES 1369 bool "16KB" 1370 select HAVE_PAGE_SIZE_16KB 1371 help 1372 The system will use 16KB pages support. AArch32 emulation 1373 requires applications compiled with 16K (or a multiple of 16K) 1374 aligned segments. 1375 1376config ARM64_64K_PAGES 1377 bool "64KB" 1378 select HAVE_PAGE_SIZE_64KB 1379 help 1380 This feature enables 64KB pages support (4KB by default) 1381 allowing only two levels of page tables and faster TLB 1382 look-up. AArch32 emulation requires applications compiled 1383 with 64K aligned segments. 1384 1385endchoice 1386 1387choice 1388 prompt "Virtual address space size" 1389 default ARM64_VA_BITS_52 1390 help 1391 Allows choosing one of multiple possible virtual address 1392 space sizes. The level of translation table is determined by 1393 a combination of page size and virtual address space size. 1394 1395config ARM64_VA_BITS_36 1396 bool "36-bit" if EXPERT 1397 depends on PAGE_SIZE_16KB 1398 1399config ARM64_VA_BITS_39 1400 bool "39-bit" 1401 depends on PAGE_SIZE_4KB 1402 1403config ARM64_VA_BITS_42 1404 bool "42-bit" 1405 depends on PAGE_SIZE_64KB 1406 1407config ARM64_VA_BITS_47 1408 bool "47-bit" 1409 depends on PAGE_SIZE_16KB 1410 1411config ARM64_VA_BITS_48 1412 bool "48-bit" 1413 1414config ARM64_VA_BITS_52 1415 bool "52-bit" 1416 help 1417 Enable 52-bit virtual addressing for userspace when explicitly 1418 requested via a hint to mmap(). The kernel will also use 52-bit 1419 virtual addresses for its own mappings (provided HW support for 1420 this feature is available, otherwise it reverts to 48-bit). 1421 1422 NOTE: Enabling 52-bit virtual addressing in conjunction with 1423 ARMv8.3 Pointer Authentication will result in the PAC being 1424 reduced from 7 bits to 3 bits, which may have a significant 1425 impact on its susceptibility to brute-force attacks. 1426 1427 If unsure, select 48-bit virtual addressing instead. 1428 1429endchoice 1430 1431config ARM64_FORCE_52BIT 1432 bool "Force 52-bit virtual addresses for userspace" 1433 depends on ARM64_VA_BITS_52 && EXPERT 1434 help 1435 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1436 to maintain compatibility with older software by providing 48-bit VAs 1437 unless a hint is supplied to mmap. 1438 1439 This configuration option disables the 48-bit compatibility logic, and 1440 forces all userspace addresses to be 52-bit on HW that supports it. One 1441 should only enable this configuration option for stress testing userspace 1442 memory management code. If unsure say N here. 1443 1444config ARM64_VA_BITS 1445 int 1446 default 36 if ARM64_VA_BITS_36 1447 default 39 if ARM64_VA_BITS_39 1448 default 42 if ARM64_VA_BITS_42 1449 default 47 if ARM64_VA_BITS_47 1450 default 48 if ARM64_VA_BITS_48 1451 default 52 if ARM64_VA_BITS_52 1452 1453choice 1454 prompt "Physical address space size" 1455 default ARM64_PA_BITS_48 1456 help 1457 Choose the maximum physical address range that the kernel will 1458 support. 1459 1460config ARM64_PA_BITS_48 1461 bool "48-bit" 1462 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1463 1464config ARM64_PA_BITS_52 1465 bool "52-bit" 1466 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1467 help 1468 Enable support for a 52-bit physical address space, introduced as 1469 part of the ARMv8.2-LPA extension. 1470 1471 With this enabled, the kernel will also continue to work on CPUs that 1472 do not support ARMv8.2-LPA, but with some added memory overhead (and 1473 minor performance overhead). 1474 1475endchoice 1476 1477config ARM64_PA_BITS 1478 int 1479 default 48 if ARM64_PA_BITS_48 1480 default 52 if ARM64_PA_BITS_52 1481 1482config ARM64_LPA2 1483 def_bool y 1484 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1485 1486choice 1487 prompt "Endianness" 1488 default CPU_LITTLE_ENDIAN 1489 help 1490 Select the endianness of data accesses performed by the CPU. Userspace 1491 applications will need to be compiled and linked for the endianness 1492 that is selected here. 1493 1494config CPU_BIG_ENDIAN 1495 bool "Build big-endian kernel" 1496 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1497 depends on AS_IS_GNU || AS_VERSION >= 150000 1498 help 1499 Say Y if you plan on running a kernel with a big-endian userspace. 1500 1501config CPU_LITTLE_ENDIAN 1502 bool "Build little-endian kernel" 1503 help 1504 Say Y if you plan on running a kernel with a little-endian userspace. 1505 This is usually the case for distributions targeting arm64. 1506 1507endchoice 1508 1509config SCHED_MC 1510 bool "Multi-core scheduler support" 1511 help 1512 Multi-core scheduler support improves the CPU scheduler's decision 1513 making when dealing with multi-core CPU chips at a cost of slightly 1514 increased overhead in some places. If unsure say N here. 1515 1516config SCHED_CLUSTER 1517 bool "Cluster scheduler support" 1518 help 1519 Cluster scheduler support improves the CPU scheduler's decision 1520 making when dealing with machines that have clusters of CPUs. 1521 Cluster usually means a couple of CPUs which are placed closely 1522 by sharing mid-level caches, last-level cache tags or internal 1523 busses. 1524 1525config SCHED_SMT 1526 bool "SMT scheduler support" 1527 help 1528 Improves the CPU scheduler's decision making when dealing with 1529 MultiThreading at a cost of slightly increased overhead in some 1530 places. If unsure say N here. 1531 1532config NR_CPUS 1533 int "Maximum number of CPUs (2-4096)" 1534 range 2 4096 1535 default "512" 1536 1537config HOTPLUG_CPU 1538 bool "Support for hot-pluggable CPUs" 1539 select GENERIC_IRQ_MIGRATION 1540 help 1541 Say Y here to experiment with turning CPUs off and on. CPUs 1542 can be controlled through /sys/devices/system/cpu. 1543 1544# Common NUMA Features 1545config NUMA 1546 bool "NUMA Memory Allocation and Scheduler Support" 1547 select GENERIC_ARCH_NUMA 1548 select OF_NUMA 1549 select HAVE_SETUP_PER_CPU_AREA 1550 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1551 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1552 select USE_PERCPU_NUMA_NODE_ID 1553 help 1554 Enable NUMA (Non-Uniform Memory Access) support. 1555 1556 The kernel will try to allocate memory used by a CPU on the 1557 local memory of the CPU and add some more 1558 NUMA awareness to the kernel. 1559 1560config NODES_SHIFT 1561 int "Maximum NUMA Nodes (as a power of 2)" 1562 range 1 10 1563 default "4" 1564 depends on NUMA 1565 help 1566 Specify the maximum number of NUMA Nodes available on the target 1567 system. Increases memory reserved to accommodate various tables. 1568 1569source "kernel/Kconfig.hz" 1570 1571config ARCH_SPARSEMEM_ENABLE 1572 def_bool y 1573 select SPARSEMEM_VMEMMAP_ENABLE 1574 select SPARSEMEM_VMEMMAP 1575 1576config HW_PERF_EVENTS 1577 def_bool y 1578 depends on ARM_PMU 1579 1580# Supported by clang >= 7.0 or GCC >= 12.0.0 1581config CC_HAVE_SHADOW_CALL_STACK 1582 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1583 1584config PARAVIRT 1585 bool "Enable paravirtualization code" 1586 help 1587 This changes the kernel so it can modify itself when it is run 1588 under a hypervisor, potentially improving performance significantly 1589 over full virtualization. 1590 1591config PARAVIRT_TIME_ACCOUNTING 1592 bool "Paravirtual steal time accounting" 1593 select PARAVIRT 1594 help 1595 Select this option to enable fine granularity task steal time 1596 accounting. Time spent executing other tasks in parallel with 1597 the current vCPU is discounted from the vCPU power. To account for 1598 that, there can be a small performance impact. 1599 1600 If in doubt, say N here. 1601 1602config ARCH_SUPPORTS_KEXEC 1603 def_bool PM_SLEEP_SMP 1604 1605config ARCH_SUPPORTS_KEXEC_FILE 1606 def_bool y 1607 1608config ARCH_SELECTS_KEXEC_FILE 1609 def_bool y 1610 depends on KEXEC_FILE 1611 select HAVE_IMA_KEXEC if IMA 1612 1613config ARCH_SUPPORTS_KEXEC_SIG 1614 def_bool y 1615 1616config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1617 def_bool y 1618 1619config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1620 def_bool y 1621 1622config ARCH_SUPPORTS_KEXEC_HANDOVER 1623 def_bool y 1624 1625config ARCH_SUPPORTS_CRASH_DUMP 1626 def_bool y 1627 1628config ARCH_DEFAULT_CRASH_DUMP 1629 def_bool y 1630 1631config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1632 def_bool CRASH_RESERVE 1633 1634config TRANS_TABLE 1635 def_bool y 1636 depends on HIBERNATION || KEXEC_CORE 1637 1638config XEN_DOM0 1639 def_bool y 1640 depends on XEN 1641 1642config XEN 1643 bool "Xen guest support on ARM64" 1644 depends on ARM64 && OF 1645 select SWIOTLB_XEN 1646 select PARAVIRT 1647 help 1648 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1649 1650# include/linux/mmzone.h requires the following to be true: 1651# 1652# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1653# 1654# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1655# 1656# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1657# ----+-------------------+--------------+----------------------+-------------------------+ 1658# 4K | 27 | 12 | 15 | 10 | 1659# 16K | 27 | 14 | 13 | 11 | 1660# 64K | 29 | 16 | 13 | 13 | 1661config ARCH_FORCE_MAX_ORDER 1662 int 1663 default "13" if ARM64_64K_PAGES 1664 default "11" if ARM64_16K_PAGES 1665 default "10" 1666 help 1667 The kernel page allocator limits the size of maximal physically 1668 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1669 defines the maximal power of two of number of pages that can be 1670 allocated as a single contiguous block. This option allows 1671 overriding the default setting when ability to allocate very 1672 large blocks of physically contiguous memory is required. 1673 1674 The maximal size of allocation cannot exceed the size of the 1675 section, so the value of MAX_PAGE_ORDER should satisfy 1676 1677 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1678 1679 Don't change if unsure. 1680 1681config UNMAP_KERNEL_AT_EL0 1682 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1683 default y 1684 help 1685 Speculation attacks against some high-performance processors can 1686 be used to bypass MMU permission checks and leak kernel data to 1687 userspace. This can be defended against by unmapping the kernel 1688 when running in userspace, mapping it back in on exception entry 1689 via a trampoline page in the vector table. 1690 1691 If unsure, say Y. 1692 1693config MITIGATE_SPECTRE_BRANCH_HISTORY 1694 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1695 default y 1696 help 1697 Speculation attacks against some high-performance processors can 1698 make use of branch history to influence future speculation. 1699 When taking an exception from user-space, a sequence of branches 1700 or a firmware call overwrites the branch history. 1701 1702config RODATA_FULL_DEFAULT_ENABLED 1703 bool "Apply r/o permissions of VM areas also to their linear aliases" 1704 default y 1705 help 1706 Apply read-only attributes of VM areas to the linear alias of 1707 the backing pages as well. This prevents code or read-only data 1708 from being modified (inadvertently or intentionally) via another 1709 mapping of the same memory page. This additional enhancement can 1710 be turned off at runtime by passing rodata=[off|on] (and turned on 1711 with rodata=full if this option is set to 'n') 1712 1713 This requires the linear region to be mapped down to pages, 1714 which may adversely affect performance in some cases. 1715 1716config ARM64_SW_TTBR0_PAN 1717 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1718 depends on !KCSAN 1719 select ARM64_PAN 1720 help 1721 Enabling this option prevents the kernel from accessing 1722 user-space memory directly by pointing TTBR0_EL1 to a reserved 1723 zeroed area and reserved ASID. The user access routines 1724 restore the valid TTBR0_EL1 temporarily. 1725 1726config ARM64_TAGGED_ADDR_ABI 1727 bool "Enable the tagged user addresses syscall ABI" 1728 default y 1729 help 1730 When this option is enabled, user applications can opt in to a 1731 relaxed ABI via prctl() allowing tagged addresses to be passed 1732 to system calls as pointer arguments. For details, see 1733 Documentation/arch/arm64/tagged-address-abi.rst. 1734 1735menuconfig COMPAT 1736 bool "Kernel support for 32-bit EL0" 1737 depends on ARM64_4K_PAGES || EXPERT 1738 select HAVE_UID16 1739 select OLD_SIGSUSPEND3 1740 select COMPAT_OLD_SIGACTION 1741 help 1742 This option enables support for a 32-bit EL0 running under a 64-bit 1743 kernel at EL1. AArch32-specific components such as system calls, 1744 the user helper functions, VFP support and the ptrace interface are 1745 handled appropriately by the kernel. 1746 1747 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1748 that you will only be able to execute AArch32 binaries that were compiled 1749 with page size aligned segments. 1750 1751 If you want to execute 32-bit userspace applications, say Y. 1752 1753if COMPAT 1754 1755config KUSER_HELPERS 1756 bool "Enable kuser helpers page for 32-bit applications" 1757 default y 1758 help 1759 Warning: disabling this option may break 32-bit user programs. 1760 1761 Provide kuser helpers to compat tasks. The kernel provides 1762 helper code to userspace in read only form at a fixed location 1763 to allow userspace to be independent of the CPU type fitted to 1764 the system. This permits binaries to be run on ARMv4 through 1765 to ARMv8 without modification. 1766 1767 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1768 1769 However, the fixed address nature of these helpers can be used 1770 by ROP (return orientated programming) authors when creating 1771 exploits. 1772 1773 If all of the binaries and libraries which run on your platform 1774 are built specifically for your platform, and make no use of 1775 these helpers, then you can turn this option off to hinder 1776 such exploits. However, in that case, if a binary or library 1777 relying on those helpers is run, it will not function correctly. 1778 1779 Say N here only if you are absolutely certain that you do not 1780 need these helpers; otherwise, the safe option is to say Y. 1781 1782config COMPAT_VDSO 1783 bool "Enable vDSO for 32-bit applications" 1784 depends on !CPU_BIG_ENDIAN 1785 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1786 select GENERIC_COMPAT_VDSO 1787 default y 1788 help 1789 Place in the process address space of 32-bit applications an 1790 ELF shared object providing fast implementations of gettimeofday 1791 and clock_gettime. 1792 1793 You must have a 32-bit build of glibc 2.22 or later for programs 1794 to seamlessly take advantage of this. 1795 1796config THUMB2_COMPAT_VDSO 1797 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1798 depends on COMPAT_VDSO 1799 default y 1800 help 1801 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1802 otherwise with '-marm'. 1803 1804config COMPAT_ALIGNMENT_FIXUPS 1805 bool "Fix up misaligned multi-word loads and stores in user space" 1806 1807menuconfig ARMV8_DEPRECATED 1808 bool "Emulate deprecated/obsolete ARMv8 instructions" 1809 depends on SYSCTL 1810 help 1811 Legacy software support may require certain instructions 1812 that have been deprecated or obsoleted in the architecture. 1813 1814 Enable this config to enable selective emulation of these 1815 features. 1816 1817 If unsure, say Y 1818 1819if ARMV8_DEPRECATED 1820 1821config SWP_EMULATION 1822 bool "Emulate SWP/SWPB instructions" 1823 help 1824 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1825 they are always undefined. Say Y here to enable software 1826 emulation of these instructions for userspace using LDXR/STXR. 1827 This feature can be controlled at runtime with the abi.swp 1828 sysctl which is disabled by default. 1829 1830 In some older versions of glibc [<=2.8] SWP is used during futex 1831 trylock() operations with the assumption that the code will not 1832 be preempted. This invalid assumption may be more likely to fail 1833 with SWP emulation enabled, leading to deadlock of the user 1834 application. 1835 1836 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1837 on an external transaction monitoring block called a global 1838 monitor to maintain update atomicity. If your system does not 1839 implement a global monitor, this option can cause programs that 1840 perform SWP operations to uncached memory to deadlock. 1841 1842 If unsure, say Y 1843 1844config CP15_BARRIER_EMULATION 1845 bool "Emulate CP15 Barrier instructions" 1846 help 1847 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1848 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1849 strongly recommended to use the ISB, DSB, and DMB 1850 instructions instead. 1851 1852 Say Y here to enable software emulation of these 1853 instructions for AArch32 userspace code. When this option is 1854 enabled, CP15 barrier usage is traced which can help 1855 identify software that needs updating. This feature can be 1856 controlled at runtime with the abi.cp15_barrier sysctl. 1857 1858 If unsure, say Y 1859 1860config SETEND_EMULATION 1861 bool "Emulate SETEND instruction" 1862 help 1863 The SETEND instruction alters the data-endianness of the 1864 AArch32 EL0, and is deprecated in ARMv8. 1865 1866 Say Y here to enable software emulation of the instruction 1867 for AArch32 userspace code. This feature can be controlled 1868 at runtime with the abi.setend sysctl. 1869 1870 Note: All the cpus on the system must have mixed endian support at EL0 1871 for this feature to be enabled. If a new CPU - which doesn't support mixed 1872 endian - is hotplugged in after this feature has been enabled, there could 1873 be unexpected results in the applications. 1874 1875 If unsure, say Y 1876endif # ARMV8_DEPRECATED 1877 1878endif # COMPAT 1879 1880menu "ARMv8.1 architectural features" 1881 1882config ARM64_HW_AFDBM 1883 bool "Support for hardware updates of the Access and Dirty page flags" 1884 default y 1885 help 1886 The ARMv8.1 architecture extensions introduce support for 1887 hardware updates of the access and dirty information in page 1888 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1889 capable processors, accesses to pages with PTE_AF cleared will 1890 set this bit instead of raising an access flag fault. 1891 Similarly, writes to read-only pages with the DBM bit set will 1892 clear the read-only bit (AP[2]) instead of raising a 1893 permission fault. 1894 1895 Kernels built with this configuration option enabled continue 1896 to work on pre-ARMv8.1 hardware and the performance impact is 1897 minimal. If unsure, say Y. 1898 1899config ARM64_PAN 1900 bool "Enable support for Privileged Access Never (PAN)" 1901 default y 1902 help 1903 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1904 prevents the kernel or hypervisor from accessing user-space (EL0) 1905 memory directly. 1906 1907 Choosing this option will cause any unprotected (not using 1908 copy_to_user et al) memory access to fail with a permission fault. 1909 1910 The feature is detected at runtime, and will remain as a 'nop' 1911 instruction if the cpu does not implement the feature. 1912 1913config ARM64_LSE_ATOMICS 1914 bool 1915 default ARM64_USE_LSE_ATOMICS 1916 1917config ARM64_USE_LSE_ATOMICS 1918 bool "Atomic instructions" 1919 default y 1920 help 1921 As part of the Large System Extensions, ARMv8.1 introduces new 1922 atomic instructions that are designed specifically to scale in 1923 very large systems. 1924 1925 Say Y here to make use of these instructions for the in-kernel 1926 atomic routines. This incurs a small overhead on CPUs that do 1927 not support these instructions. 1928 1929endmenu # "ARMv8.1 architectural features" 1930 1931menu "ARMv8.2 architectural features" 1932 1933config ARM64_PMEM 1934 bool "Enable support for persistent memory" 1935 select ARCH_HAS_PMEM_API 1936 select ARCH_HAS_UACCESS_FLUSHCACHE 1937 help 1938 Say Y to enable support for the persistent memory API based on the 1939 ARMv8.2 DCPoP feature. 1940 1941 The feature is detected at runtime, and the kernel will use DC CVAC 1942 operations if DC CVAP is not supported (following the behaviour of 1943 DC CVAP itself if the system does not define a point of persistence). 1944 1945config ARM64_RAS_EXTN 1946 bool "Enable support for RAS CPU Extensions" 1947 default y 1948 help 1949 CPUs that support the Reliability, Availability and Serviceability 1950 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1951 errors, classify them and report them to software. 1952 1953 On CPUs with these extensions system software can use additional 1954 barriers to determine if faults are pending and read the 1955 classification from a new set of registers. 1956 1957 Selecting this feature will allow the kernel to use these barriers 1958 and access the new registers if the system supports the extension. 1959 Platform RAS features may additionally depend on firmware support. 1960 1961config ARM64_CNP 1962 bool "Enable support for Common Not Private (CNP) translations" 1963 default y 1964 help 1965 Common Not Private (CNP) allows translation table entries to 1966 be shared between different PEs in the same inner shareable 1967 domain, so the hardware can use this fact to optimise the 1968 caching of such entries in the TLB. 1969 1970 Selecting this option allows the CNP feature to be detected 1971 at runtime, and does not affect PEs that do not implement 1972 this feature. 1973 1974endmenu # "ARMv8.2 architectural features" 1975 1976menu "ARMv8.3 architectural features" 1977 1978config ARM64_PTR_AUTH 1979 bool "Enable support for pointer authentication" 1980 default y 1981 help 1982 Pointer authentication (part of the ARMv8.3 Extensions) provides 1983 instructions for signing and authenticating pointers against secret 1984 keys, which can be used to mitigate Return Oriented Programming (ROP) 1985 and other attacks. 1986 1987 This option enables these instructions at EL0 (i.e. for userspace). 1988 Choosing this option will cause the kernel to initialise secret keys 1989 for each process at exec() time, with these keys being 1990 context-switched along with the process. 1991 1992 The feature is detected at runtime. If the feature is not present in 1993 hardware it will not be advertised to userspace/KVM guest nor will it 1994 be enabled. 1995 1996 If the feature is present on the boot CPU but not on a late CPU, then 1997 the late CPU will be parked. Also, if the boot CPU does not have 1998 address auth and the late CPU has then the late CPU will still boot 1999 but with the feature disabled. On such a system, this option should 2000 not be selected. 2001 2002config ARM64_PTR_AUTH_KERNEL 2003 bool "Use pointer authentication for kernel" 2004 default y 2005 depends on ARM64_PTR_AUTH 2006 # Modern compilers insert a .note.gnu.property section note for PAC 2007 # which is only understood by binutils starting with version 2.33.1. 2008 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2009 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2010 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2011 help 2012 If the compiler supports the -mbranch-protection or 2013 -msign-return-address flag (e.g. GCC 7 or later), then this option 2014 will cause the kernel itself to be compiled with return address 2015 protection. In this case, and if the target hardware is known to 2016 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2017 disabled with minimal loss of protection. 2018 2019 This feature works with FUNCTION_GRAPH_TRACER option only if 2020 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2021 2022config CC_HAS_BRANCH_PROT_PAC_RET 2023 # GCC 9 or later, clang 8 or later 2024 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2025 2026config AS_HAS_CFI_NEGATE_RA_STATE 2027 # binutils 2.34+ 2028 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2029 2030endmenu # "ARMv8.3 architectural features" 2031 2032menu "ARMv8.4 architectural features" 2033 2034config ARM64_AMU_EXTN 2035 bool "Enable support for the Activity Monitors Unit CPU extension" 2036 default y 2037 help 2038 The activity monitors extension is an optional extension introduced 2039 by the ARMv8.4 CPU architecture. This enables support for version 1 2040 of the activity monitors architecture, AMUv1. 2041 2042 To enable the use of this extension on CPUs that implement it, say Y. 2043 2044 Note that for architectural reasons, firmware _must_ implement AMU 2045 support when running on CPUs that present the activity monitors 2046 extension. The required support is present in: 2047 * Version 1.5 and later of the ARM Trusted Firmware 2048 2049 For kernels that have this configuration enabled but boot with broken 2050 firmware, you may need to say N here until the firmware is fixed. 2051 Otherwise you may experience firmware panics or lockups when 2052 accessing the counter registers. Even if you are not observing these 2053 symptoms, the values returned by the register reads might not 2054 correctly reflect reality. Most commonly, the value read will be 0, 2055 indicating that the counter is not enabled. 2056 2057config ARM64_TLB_RANGE 2058 bool "Enable support for tlbi range feature" 2059 default y 2060 help 2061 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2062 range of input addresses. 2063 2064endmenu # "ARMv8.4 architectural features" 2065 2066menu "ARMv8.5 architectural features" 2067 2068config AS_HAS_ARMV8_5 2069 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2070 2071config ARM64_BTI 2072 bool "Branch Target Identification support" 2073 default y 2074 help 2075 Branch Target Identification (part of the ARMv8.5 Extensions) 2076 provides a mechanism to limit the set of locations to which computed 2077 branch instructions such as BR or BLR can jump. 2078 2079 To make use of BTI on CPUs that support it, say Y. 2080 2081 BTI is intended to provide complementary protection to other control 2082 flow integrity protection mechanisms, such as the Pointer 2083 authentication mechanism provided as part of the ARMv8.3 Extensions. 2084 For this reason, it does not make sense to enable this option without 2085 also enabling support for pointer authentication. Thus, when 2086 enabling this option you should also select ARM64_PTR_AUTH=y. 2087 2088 Userspace binaries must also be specifically compiled to make use of 2089 this mechanism. If you say N here or the hardware does not support 2090 BTI, such binaries can still run, but you get no additional 2091 enforcement of branch destinations. 2092 2093config ARM64_BTI_KERNEL 2094 bool "Use Branch Target Identification for kernel" 2095 default y 2096 depends on ARM64_BTI 2097 depends on ARM64_PTR_AUTH_KERNEL 2098 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2099 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2100 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2101 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2102 depends on !CC_IS_GCC 2103 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2104 help 2105 Build the kernel with Branch Target Identification annotations 2106 and enable enforcement of this for kernel code. When this option 2107 is enabled and the system supports BTI all kernel code including 2108 modular code must have BTI enabled. 2109 2110config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2111 # GCC 9 or later, clang 8 or later 2112 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2113 2114config ARM64_E0PD 2115 bool "Enable support for E0PD" 2116 default y 2117 help 2118 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2119 that EL0 accesses made via TTBR1 always fault in constant time, 2120 providing similar benefits to KASLR as those provided by KPTI, but 2121 with lower overhead and without disrupting legitimate access to 2122 kernel memory such as SPE. 2123 2124 This option enables E0PD for TTBR1 where available. 2125 2126config ARM64_AS_HAS_MTE 2127 # Initial support for MTE went in binutils 2.32.0, checked with 2128 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2129 # as a late addition to the final architecture spec (LDGM/STGM) 2130 # is only supported in the newer 2.32.x and 2.33 binutils 2131 # versions, hence the extra "stgm" instruction check below. 2132 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2133 2134config ARM64_MTE 2135 bool "Memory Tagging Extension support" 2136 default y 2137 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2138 depends on AS_HAS_ARMV8_5 2139 # Required for tag checking in the uaccess routines 2140 select ARM64_PAN 2141 select ARCH_HAS_SUBPAGE_FAULTS 2142 select ARCH_USES_HIGH_VMA_FLAGS 2143 select ARCH_USES_PG_ARCH_2 2144 select ARCH_USES_PG_ARCH_3 2145 help 2146 Memory Tagging (part of the ARMv8.5 Extensions) provides 2147 architectural support for run-time, always-on detection of 2148 various classes of memory error to aid with software debugging 2149 to eliminate vulnerabilities arising from memory-unsafe 2150 languages. 2151 2152 This option enables the support for the Memory Tagging 2153 Extension at EL0 (i.e. for userspace). 2154 2155 Selecting this option allows the feature to be detected at 2156 runtime. Any secondary CPU not implementing this feature will 2157 not be allowed a late bring-up. 2158 2159 Userspace binaries that want to use this feature must 2160 explicitly opt in. The mechanism for the userspace is 2161 described in: 2162 2163 Documentation/arch/arm64/memory-tagging-extension.rst. 2164 2165endmenu # "ARMv8.5 architectural features" 2166 2167menu "ARMv8.7 architectural features" 2168 2169config ARM64_EPAN 2170 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2171 default y 2172 depends on ARM64_PAN 2173 help 2174 Enhanced Privileged Access Never (EPAN) allows Privileged 2175 Access Never to be used with Execute-only mappings. 2176 2177 The feature is detected at runtime, and will remain disabled 2178 if the cpu does not implement the feature. 2179endmenu # "ARMv8.7 architectural features" 2180 2181config AS_HAS_MOPS 2182 def_bool $(as-instr,.arch_extension mops) 2183 2184menu "ARMv8.9 architectural features" 2185 2186config ARM64_POE 2187 prompt "Permission Overlay Extension" 2188 def_bool y 2189 select ARCH_USES_HIGH_VMA_FLAGS 2190 select ARCH_HAS_PKEYS 2191 help 2192 The Permission Overlay Extension is used to implement Memory 2193 Protection Keys. Memory Protection Keys provides a mechanism for 2194 enforcing page-based protections, but without requiring modification 2195 of the page tables when an application changes protection domains. 2196 2197 For details, see Documentation/core-api/protection-keys.rst 2198 2199 If unsure, say y. 2200 2201config ARCH_PKEY_BITS 2202 int 2203 default 3 2204 2205config ARM64_HAFT 2206 bool "Support for Hardware managed Access Flag for Table Descriptors" 2207 depends on ARM64_HW_AFDBM 2208 default y 2209 help 2210 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2211 Flag for Table descriptors. When enabled an architectural executed 2212 memory access will update the Access Flag in each Table descriptor 2213 which is accessed during the translation table walk and for which 2214 the Access Flag is 0. The Access Flag of the Table descriptor use 2215 the same bit of PTE_AF. 2216 2217 The feature will only be enabled if all the CPUs in the system 2218 support this feature. If unsure, say Y. 2219 2220endmenu # "ARMv8.9 architectural features" 2221 2222menu "v9.4 architectural features" 2223 2224config ARM64_GCS 2225 bool "Enable support for Guarded Control Stack (GCS)" 2226 default y 2227 select ARCH_HAS_USER_SHADOW_STACK 2228 select ARCH_USES_HIGH_VMA_FLAGS 2229 depends on !UPROBES 2230 help 2231 Guarded Control Stack (GCS) provides support for a separate 2232 stack with restricted access which contains only return 2233 addresses. This can be used to harden against some attacks 2234 by comparing return address used by the program with what is 2235 stored in the GCS, and may also be used to efficiently obtain 2236 the call stack for applications such as profiling. 2237 2238 The feature is detected at runtime, and will remain disabled 2239 if the system does not implement the feature. 2240 2241endmenu # "v9.4 architectural features" 2242 2243config ARM64_SVE 2244 bool "ARM Scalable Vector Extension support" 2245 default y 2246 help 2247 The Scalable Vector Extension (SVE) is an extension to the AArch64 2248 execution state which complements and extends the SIMD functionality 2249 of the base architecture to support much larger vectors and to enable 2250 additional vectorisation opportunities. 2251 2252 To enable use of this extension on CPUs that implement it, say Y. 2253 2254 On CPUs that support the SVE2 extensions, this option will enable 2255 those too. 2256 2257 Note that for architectural reasons, firmware _must_ implement SVE 2258 support when running on SVE capable hardware. The required support 2259 is present in: 2260 2261 * version 1.5 and later of the ARM Trusted Firmware 2262 * the AArch64 boot wrapper since commit 5e1261e08abf 2263 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2264 2265 For other firmware implementations, consult the firmware documentation 2266 or vendor. 2267 2268 If you need the kernel to boot on SVE-capable hardware with broken 2269 firmware, you may need to say N here until you get your firmware 2270 fixed. Otherwise, you may experience firmware panics or lockups when 2271 booting the kernel. If unsure and you are not observing these 2272 symptoms, you should assume that it is safe to say Y. 2273 2274config ARM64_SME 2275 bool "ARM Scalable Matrix Extension support" 2276 default y 2277 depends on ARM64_SVE 2278 help 2279 The Scalable Matrix Extension (SME) is an extension to the AArch64 2280 execution state which utilises a substantial subset of the SVE 2281 instruction set, together with the addition of new architectural 2282 register state capable of holding two dimensional matrix tiles to 2283 enable various matrix operations. 2284 2285config ARM64_PSEUDO_NMI 2286 bool "Support for NMI-like interrupts" 2287 select ARM_GIC_V3 2288 help 2289 Adds support for mimicking Non-Maskable Interrupts through the use of 2290 GIC interrupt priority. This support requires version 3 or later of 2291 ARM GIC. 2292 2293 This high priority configuration for interrupts needs to be 2294 explicitly enabled by setting the kernel parameter 2295 "irqchip.gicv3_pseudo_nmi" to 1. 2296 2297 If unsure, say N 2298 2299if ARM64_PSEUDO_NMI 2300config ARM64_DEBUG_PRIORITY_MASKING 2301 bool "Debug interrupt priority masking" 2302 help 2303 This adds runtime checks to functions enabling/disabling 2304 interrupts when using priority masking. The additional checks verify 2305 the validity of ICC_PMR_EL1 when calling concerned functions. 2306 2307 If unsure, say N 2308endif # ARM64_PSEUDO_NMI 2309 2310config RELOCATABLE 2311 bool "Build a relocatable kernel image" if EXPERT 2312 select ARCH_HAS_RELR 2313 default y 2314 help 2315 This builds the kernel as a Position Independent Executable (PIE), 2316 which retains all relocation metadata required to relocate the 2317 kernel binary at runtime to a different virtual address than the 2318 address it was linked at. 2319 Since AArch64 uses the RELA relocation format, this requires a 2320 relocation pass at runtime even if the kernel is loaded at the 2321 same address it was linked at. 2322 2323config RANDOMIZE_BASE 2324 bool "Randomize the address of the kernel image" 2325 select RELOCATABLE 2326 help 2327 Randomizes the virtual address at which the kernel image is 2328 loaded, as a security feature that deters exploit attempts 2329 relying on knowledge of the location of kernel internals. 2330 2331 It is the bootloader's job to provide entropy, by passing a 2332 random u64 value in /chosen/kaslr-seed at kernel entry. 2333 2334 When booting via the UEFI stub, it will invoke the firmware's 2335 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2336 to the kernel proper. In addition, it will randomise the physical 2337 location of the kernel Image as well. 2338 2339 If unsure, say N. 2340 2341config RANDOMIZE_MODULE_REGION_FULL 2342 bool "Randomize the module region over a 2 GB range" 2343 depends on RANDOMIZE_BASE 2344 default y 2345 help 2346 Randomizes the location of the module region inside a 2 GB window 2347 covering the core kernel. This way, it is less likely for modules 2348 to leak information about the location of core kernel data structures 2349 but it does imply that function calls between modules and the core 2350 kernel will need to be resolved via veneers in the module PLT. 2351 2352 When this option is not set, the module region will be randomized over 2353 a limited range that contains the [_stext, _etext] interval of the 2354 core kernel, so branch relocations are almost always in range unless 2355 the region is exhausted. In this particular case of region 2356 exhaustion, modules might be able to fall back to a larger 2GB area. 2357 2358config CC_HAVE_STACKPROTECTOR_SYSREG 2359 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2360 2361config STACKPROTECTOR_PER_TASK 2362 def_bool y 2363 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2364 2365config UNWIND_PATCH_PAC_INTO_SCS 2366 bool "Enable shadow call stack dynamically using code patching" 2367 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2368 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2369 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2370 depends on SHADOW_CALL_STACK 2371 select UNWIND_TABLES 2372 select DYNAMIC_SCS 2373 2374config ARM64_CONTPTE 2375 bool "Contiguous PTE mappings for user memory" if EXPERT 2376 depends on TRANSPARENT_HUGEPAGE 2377 default y 2378 help 2379 When enabled, user mappings are configured using the PTE contiguous 2380 bit, for any mappings that meet the size and alignment requirements. 2381 This reduces TLB pressure and improves performance. 2382 2383endmenu # "Kernel Features" 2384 2385menu "Boot options" 2386 2387config ARM64_ACPI_PARKING_PROTOCOL 2388 bool "Enable support for the ARM64 ACPI parking protocol" 2389 depends on ACPI 2390 help 2391 Enable support for the ARM64 ACPI parking protocol. If disabled 2392 the kernel will not allow booting through the ARM64 ACPI parking 2393 protocol even if the corresponding data is present in the ACPI 2394 MADT table. 2395 2396config CMDLINE 2397 string "Default kernel command string" 2398 default "" 2399 help 2400 Provide a set of default command-line options at build time by 2401 entering them here. As a minimum, you should specify the the 2402 root device (e.g. root=/dev/nfs). 2403 2404choice 2405 prompt "Kernel command line type" 2406 depends on CMDLINE != "" 2407 default CMDLINE_FROM_BOOTLOADER 2408 help 2409 Choose how the kernel will handle the provided default kernel 2410 command line string. 2411 2412config CMDLINE_FROM_BOOTLOADER 2413 bool "Use bootloader kernel arguments if available" 2414 help 2415 Uses the command-line options passed by the boot loader. If 2416 the boot loader doesn't provide any, the default kernel command 2417 string provided in CMDLINE will be used. 2418 2419config CMDLINE_FORCE 2420 bool "Always use the default kernel command string" 2421 help 2422 Always use the default kernel command string, even if the boot 2423 loader passes other arguments to the kernel. 2424 This is useful if you cannot or don't want to change the 2425 command-line options your boot loader passes to the kernel. 2426 2427endchoice 2428 2429config EFI_STUB 2430 bool 2431 2432config EFI 2433 bool "UEFI runtime support" 2434 depends on OF && !CPU_BIG_ENDIAN 2435 depends on KERNEL_MODE_NEON 2436 select ARCH_SUPPORTS_ACPI 2437 select LIBFDT 2438 select UCS2_STRING 2439 select EFI_PARAMS_FROM_FDT 2440 select EFI_RUNTIME_WRAPPERS 2441 select EFI_STUB 2442 select EFI_GENERIC_STUB 2443 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2444 default y 2445 help 2446 This option provides support for runtime services provided 2447 by UEFI firmware (such as non-volatile variables, realtime 2448 clock, and platform reset). A UEFI stub is also provided to 2449 allow the kernel to be booted as an EFI application. This 2450 is only useful on systems that have UEFI firmware. 2451 2452config COMPRESSED_INSTALL 2453 bool "Install compressed image by default" 2454 help 2455 This makes the regular "make install" install the compressed 2456 image we built, not the legacy uncompressed one. 2457 2458 You can check that a compressed image works for you by doing 2459 "make zinstall" first, and verifying that everything is fine 2460 in your environment before making "make install" do this for 2461 you. 2462 2463config DMI 2464 bool "Enable support for SMBIOS (DMI) tables" 2465 depends on EFI 2466 default y 2467 help 2468 This enables SMBIOS/DMI feature for systems. 2469 2470 This option is only useful on systems that have UEFI firmware. 2471 However, even with this option, the resultant kernel should 2472 continue to boot on existing non-UEFI platforms. 2473 2474endmenu # "Boot options" 2475 2476menu "Power management options" 2477 2478source "kernel/power/Kconfig" 2479 2480config ARCH_HIBERNATION_POSSIBLE 2481 def_bool y 2482 depends on CPU_PM 2483 2484config ARCH_HIBERNATION_HEADER 2485 def_bool y 2486 depends on HIBERNATION 2487 2488config ARCH_SUSPEND_POSSIBLE 2489 def_bool y 2490 2491endmenu # "Power management options" 2492 2493menu "CPU Power Management" 2494 2495source "drivers/cpuidle/Kconfig" 2496 2497source "drivers/cpufreq/Kconfig" 2498 2499endmenu # "CPU Power Management" 2500 2501source "drivers/acpi/Kconfig" 2502 2503source "arch/arm64/kvm/Kconfig" 2504 2505source "kernel/livepatch/Kconfig" 2506