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_HAS_NMI_SAFE_THIS_CPU_OPS 42 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 43 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 44 select ARCH_HAS_PTE_DEVMAP 45 select ARCH_HAS_PTE_SPECIAL 46 select ARCH_HAS_HW_PTE_YOUNG 47 select ARCH_HAS_SETUP_DMA_OPS 48 select ARCH_HAS_SET_DIRECT_MAP 49 select ARCH_HAS_SET_MEMORY 50 select ARCH_HAS_MEM_ENCRYPT 51 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 52 select ARCH_STACKWALK 53 select ARCH_HAS_STRICT_KERNEL_RWX 54 select ARCH_HAS_STRICT_MODULE_RWX 55 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 56 select ARCH_HAS_SYNC_DMA_FOR_CPU 57 select ARCH_HAS_SYSCALL_WRAPPER 58 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 59 select ARCH_HAS_ZONE_DMA_SET if EXPERT 60 select ARCH_HAVE_ELF_PROT 61 select ARCH_HAVE_NMI_SAFE_CMPXCHG 62 select ARCH_HAVE_TRACE_MMIO_ACCESS 63 select ARCH_INLINE_READ_LOCK if !PREEMPTION 64 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 67 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 71 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 75 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 79 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 80 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 81 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 85 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 89 select ARCH_KEEP_MEMBLOCK 90 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 91 select ARCH_USE_CMPXCHG_LOCKREF 92 select ARCH_USE_GNU_PROPERTY 93 select ARCH_USE_MEMTEST 94 select ARCH_USE_QUEUED_RWLOCKS 95 select ARCH_USE_QUEUED_SPINLOCKS 96 select ARCH_USE_SYM_ANNOTATIONS 97 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 98 select ARCH_SUPPORTS_HUGETLBFS 99 select ARCH_SUPPORTS_MEMORY_FAILURE 100 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 101 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 102 select ARCH_SUPPORTS_LTO_CLANG_THIN 103 select ARCH_SUPPORTS_CFI_CLANG 104 select ARCH_SUPPORTS_ATOMIC_RMW 105 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 106 select ARCH_SUPPORTS_NUMA_BALANCING 107 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 108 select ARCH_SUPPORTS_PER_VMA_LOCK 109 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 110 select ARCH_SUPPORTS_RT 111 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 112 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 113 select ARCH_WANT_DEFAULT_BPF_JIT 114 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 115 select ARCH_WANT_FRAME_POINTERS 116 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 117 select ARCH_WANT_LD_ORPHAN_WARN 118 select ARCH_WANTS_EXECMEM_LATE 119 select ARCH_WANTS_NO_INSTR 120 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 121 select ARCH_HAS_UBSAN 122 select ARM_AMBA 123 select ARM_ARCH_TIMER 124 select ARM_GIC 125 select AUDIT_ARCH_COMPAT_GENERIC 126 select ARM_GIC_V2M if PCI 127 select ARM_GIC_V3 128 select ARM_GIC_V3_ITS if PCI 129 select ARM_PSCI_FW 130 select BUILDTIME_TABLE_SORT 131 select CLONE_BACKWARDS 132 select COMMON_CLK 133 select CPU_PM if (SUSPEND || CPU_IDLE) 134 select CPUMASK_OFFSTACK if NR_CPUS > 256 135 select CRC32 136 select DCACHE_WORD_ACCESS 137 select DYNAMIC_FTRACE if FUNCTION_TRACER 138 select DMA_BOUNCE_UNALIGNED_KMALLOC 139 select DMA_DIRECT_REMAP 140 select EDAC_SUPPORT 141 select FRAME_POINTER 142 select FUNCTION_ALIGNMENT_4B 143 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 144 select GENERIC_ALLOCATOR 145 select GENERIC_ARCH_TOPOLOGY 146 select GENERIC_CLOCKEVENTS_BROADCAST 147 select GENERIC_CPU_AUTOPROBE 148 select GENERIC_CPU_DEVICES 149 select GENERIC_CPU_VULNERABILITIES 150 select GENERIC_EARLY_IOREMAP 151 select GENERIC_IDLE_POLL_SETUP 152 select GENERIC_IOREMAP 153 select GENERIC_IRQ_IPI 154 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 155 select GENERIC_IRQ_PROBE 156 select GENERIC_IRQ_SHOW 157 select GENERIC_IRQ_SHOW_LEVEL 158 select GENERIC_LIB_DEVMEM_IS_ALLOWED 159 select GENERIC_PCI_IOMAP 160 select GENERIC_PTDUMP 161 select GENERIC_SCHED_CLOCK 162 select GENERIC_SMP_IDLE_THREAD 163 select GENERIC_TIME_VSYSCALL 164 select GENERIC_GETTIMEOFDAY 165 select GENERIC_VDSO_DATA_STORE 166 select GENERIC_VDSO_TIME_NS 167 select HARDIRQS_SW_RESEND 168 select HAS_IOPORT 169 select HAVE_MOVE_PMD 170 select HAVE_MOVE_PUD 171 select HAVE_PCI 172 select HAVE_ACPI_APEI if (ACPI && EFI) 173 select HAVE_ALIGNED_STRUCT_PAGE 174 select HAVE_ARCH_AUDITSYSCALL 175 select HAVE_ARCH_BITREVERSE 176 select HAVE_ARCH_COMPILER_H 177 select HAVE_ARCH_HUGE_VMALLOC 178 select HAVE_ARCH_HUGE_VMAP 179 select HAVE_ARCH_JUMP_LABEL 180 select HAVE_ARCH_JUMP_LABEL_RELATIVE 181 select HAVE_ARCH_KASAN 182 select HAVE_ARCH_KASAN_VMALLOC 183 select HAVE_ARCH_KASAN_SW_TAGS 184 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 185 # Some instrumentation may be unsound, hence EXPERT 186 select HAVE_ARCH_KCSAN if EXPERT 187 select HAVE_ARCH_KFENCE 188 select HAVE_ARCH_KGDB 189 select HAVE_ARCH_MMAP_RND_BITS 190 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 191 select HAVE_ARCH_PREL32_RELOCATIONS 192 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 193 select HAVE_ARCH_SECCOMP_FILTER 194 select HAVE_ARCH_STACKLEAK 195 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 196 select HAVE_ARCH_TRACEHOOK 197 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 198 select HAVE_ARCH_VMAP_STACK 199 select HAVE_ARM_SMCCC 200 select HAVE_ASM_MODVERSIONS 201 select HAVE_EBPF_JIT 202 select HAVE_C_RECORDMCOUNT 203 select HAVE_CMPXCHG_DOUBLE 204 select HAVE_CMPXCHG_LOCAL 205 select HAVE_CONTEXT_TRACKING_USER 206 select HAVE_DEBUG_KMEMLEAK 207 select HAVE_DMA_CONTIGUOUS 208 select HAVE_DYNAMIC_FTRACE 209 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 210 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 211 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 212 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 213 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 214 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 215 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 216 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 217 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 218 if DYNAMIC_FTRACE_WITH_ARGS 219 select HAVE_SAMPLE_FTRACE_DIRECT 220 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 221 select HAVE_EFFICIENT_UNALIGNED_ACCESS 222 select HAVE_GUP_FAST 223 select HAVE_FTRACE_GRAPH_FUNC 224 select HAVE_FTRACE_MCOUNT_RECORD 225 select HAVE_FUNCTION_TRACER 226 select HAVE_FUNCTION_ERROR_INJECTION 227 select HAVE_FUNCTION_GRAPH_FREGS 228 select HAVE_FUNCTION_GRAPH_TRACER 229 select HAVE_GCC_PLUGINS 230 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 231 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 232 select HAVE_HW_BREAKPOINT if PERF_EVENTS 233 select HAVE_IOREMAP_PROT 234 select HAVE_IRQ_TIME_ACCOUNTING 235 select HAVE_MOD_ARCH_SPECIFIC 236 select HAVE_NMI 237 select HAVE_PERF_EVENTS 238 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 239 select HAVE_PERF_REGS 240 select HAVE_PERF_USER_STACK_DUMP 241 select HAVE_PREEMPT_DYNAMIC_KEY 242 select HAVE_REGS_AND_STACK_ACCESS_API 243 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 244 select HAVE_FUNCTION_ARG_ACCESS_API 245 select MMU_GATHER_RCU_TABLE_FREE 246 select HAVE_RSEQ 247 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 248 select HAVE_STACKPROTECTOR 249 select HAVE_SYSCALL_TRACEPOINTS 250 select HAVE_KPROBES 251 select HAVE_KRETPROBES 252 select HAVE_GENERIC_VDSO 253 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 254 select HOTPLUG_SMT if HOTPLUG_CPU 255 select IRQ_DOMAIN 256 select IRQ_FORCED_THREADING 257 select KASAN_VMALLOC if KASAN 258 select LOCK_MM_AND_FIND_VMA 259 select MODULES_USE_ELF_RELA 260 select NEED_DMA_MAP_STATE 261 select NEED_SG_DMA_LENGTH 262 select OF 263 select OF_EARLY_FLATTREE 264 select PCI_DOMAINS_GENERIC if PCI 265 select PCI_ECAM if (ACPI && PCI) 266 select PCI_SYSCALL if PCI 267 select POWER_RESET 268 select POWER_SUPPLY 269 select SPARSE_IRQ 270 select SWIOTLB 271 select SYSCTL_EXCEPTION_TRACE 272 select THREAD_INFO_IN_TASK 273 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 274 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 275 select TRACE_IRQFLAGS_SUPPORT 276 select TRACE_IRQFLAGS_NMI_SUPPORT 277 select HAVE_SOFTIRQ_ON_OWN_STACK 278 select USER_STACKTRACE_SUPPORT 279 select VDSO_GETRANDOM 280 help 281 ARM 64-bit (AArch64) Linux support. 282 283config RUSTC_SUPPORTS_ARM64 284 def_bool y 285 depends on CPU_LITTLE_ENDIAN 286 # Shadow call stack is only supported on certain rustc versions. 287 # 288 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 289 # required due to use of the -Zfixed-x18 flag. 290 # 291 # Otherwise, rustc version 1.82+ is required due to use of the 292 # -Zsanitizer=shadow-call-stack flag. 293 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 294 295config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 296 def_bool CC_IS_CLANG 297 # https://github.com/ClangBuiltLinux/linux/issues/1507 298 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 299 300config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 301 def_bool CC_IS_GCC 302 depends on $(cc-option,-fpatchable-function-entry=2) 303 304config 64BIT 305 def_bool y 306 307config MMU 308 def_bool y 309 310config ARM64_CONT_PTE_SHIFT 311 int 312 default 5 if PAGE_SIZE_64KB 313 default 7 if PAGE_SIZE_16KB 314 default 4 315 316config ARM64_CONT_PMD_SHIFT 317 int 318 default 5 if PAGE_SIZE_64KB 319 default 5 if PAGE_SIZE_16KB 320 default 4 321 322config ARCH_MMAP_RND_BITS_MIN 323 default 14 if PAGE_SIZE_64KB 324 default 16 if PAGE_SIZE_16KB 325 default 18 326 327# max bits determined by the following formula: 328# VA_BITS - PTDESC_TABLE_SHIFT 329config ARCH_MMAP_RND_BITS_MAX 330 default 19 if ARM64_VA_BITS=36 331 default 24 if ARM64_VA_BITS=39 332 default 27 if ARM64_VA_BITS=42 333 default 30 if ARM64_VA_BITS=47 334 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 335 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 336 default 33 if ARM64_VA_BITS=48 337 default 14 if ARM64_64K_PAGES 338 default 16 if ARM64_16K_PAGES 339 default 18 340 341config ARCH_MMAP_RND_COMPAT_BITS_MIN 342 default 7 if ARM64_64K_PAGES 343 default 9 if ARM64_16K_PAGES 344 default 11 345 346config ARCH_MMAP_RND_COMPAT_BITS_MAX 347 default 16 348 349config NO_IOPORT_MAP 350 def_bool y if !PCI 351 352config STACKTRACE_SUPPORT 353 def_bool y 354 355config ILLEGAL_POINTER_VALUE 356 hex 357 default 0xdead000000000000 358 359config LOCKDEP_SUPPORT 360 def_bool y 361 362config GENERIC_BUG 363 def_bool y 364 depends on BUG 365 366config GENERIC_BUG_RELATIVE_POINTERS 367 def_bool y 368 depends on GENERIC_BUG 369 370config GENERIC_HWEIGHT 371 def_bool y 372 373config GENERIC_CSUM 374 def_bool y 375 376config GENERIC_CALIBRATE_DELAY 377 def_bool y 378 379config SMP 380 def_bool y 381 382config KERNEL_MODE_NEON 383 def_bool y 384 385config FIX_EARLYCON_MEM 386 def_bool y 387 388config PGTABLE_LEVELS 389 int 390 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 391 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 392 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 393 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 394 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 395 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 396 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 397 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 398 399config ARCH_SUPPORTS_UPROBES 400 def_bool y 401 402config ARCH_PROC_KCORE_TEXT 403 def_bool y 404 405config BROKEN_GAS_INST 406 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 407 408config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 409 bool 410 # Clang's __builtin_return_address() strips the PAC since 12.0.0 411 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 412 default y if CC_IS_CLANG 413 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 414 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 415 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 416 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 417 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 418 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 419 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 420 default n 421 422config KASAN_SHADOW_OFFSET 423 hex 424 depends on KASAN_GENERIC || KASAN_SW_TAGS 425 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 426 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 427 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 428 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 429 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 430 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 431 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 432 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 433 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 434 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 435 default 0xffffffffffffffff 436 437config UNWIND_TABLES 438 bool 439 440source "arch/arm64/Kconfig.platforms" 441 442menu "Kernel Features" 443 444menu "ARM errata workarounds via the alternatives framework" 445 446config AMPERE_ERRATUM_AC03_CPU_38 447 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 448 default y 449 help 450 This option adds an alternative code sequence to work around Ampere 451 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 452 453 The affected design reports FEAT_HAFDBS as not implemented in 454 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 455 as required by the architecture. The unadvertised HAFDBS 456 implementation suffers from an additional erratum where hardware 457 A/D updates can occur after a PTE has been marked invalid. 458 459 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 460 which avoids enabling unadvertised hardware Access Flag management 461 at stage-2. 462 463 If unsure, say Y. 464 465config ARM64_WORKAROUND_CLEAN_CACHE 466 bool 467 468config ARM64_ERRATUM_826319 469 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 470 default y 471 select ARM64_WORKAROUND_CLEAN_CACHE 472 help 473 This option adds an alternative code sequence to work around ARM 474 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 475 AXI master interface and an L2 cache. 476 477 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 478 and is unable to accept a certain write via this interface, it will 479 not progress on read data presented on the read data channel and the 480 system can deadlock. 481 482 The workaround promotes data cache clean instructions to 483 data cache clean-and-invalidate. 484 Please note that this does not necessarily enable the workaround, 485 as it depends on the alternative framework, which will only patch 486 the kernel if an affected CPU is detected. 487 488 If unsure, say Y. 489 490config ARM64_ERRATUM_827319 491 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 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 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 497 master interface and an L2 cache. 498 499 Under certain conditions this erratum can cause a clean line eviction 500 to occur at the same time as another transaction to the same address 501 on the AMBA 5 CHI interface, which can cause data corruption if the 502 interconnect reorders the two transactions. 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_824069 513 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 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 824069 on Cortex-A53 parts up to r0p2 when it is connected 519 to a coherent interconnect. 520 521 If a Cortex-A53 processor is executing a store or prefetch for 522 write instruction at the same time as a processor in another 523 cluster is executing a cache maintenance operation to the same 524 address, then this erratum might cause a clean cache line to be 525 incorrectly marked as dirty. 526 527 The workaround promotes data cache clean instructions to 528 data cache clean-and-invalidate. 529 Please note that this option does not necessarily enable the 530 workaround, as it depends on the alternative framework, which will 531 only patch the kernel if an affected CPU is detected. 532 533 If unsure, say Y. 534 535config ARM64_ERRATUM_819472 536 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 537 default y 538 select ARM64_WORKAROUND_CLEAN_CACHE 539 help 540 This option adds an alternative code sequence to work around ARM 541 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 542 present when it is connected to a coherent interconnect. 543 544 If the processor is executing a load and store exclusive sequence at 545 the same time as a processor in another cluster is executing a cache 546 maintenance operation to the same address, then this erratum might 547 cause data corruption. 548 549 The workaround promotes data cache clean instructions to 550 data cache clean-and-invalidate. 551 Please note that this does not necessarily enable the workaround, 552 as it depends on the alternative framework, which will only patch 553 the kernel if an affected CPU is detected. 554 555 If unsure, say Y. 556 557config ARM64_ERRATUM_832075 558 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 559 default y 560 help 561 This option adds an alternative code sequence to work around ARM 562 erratum 832075 on Cortex-A57 parts up to r1p2. 563 564 Affected Cortex-A57 parts might deadlock when exclusive load/store 565 instructions to Write-Back memory are mixed with Device loads. 566 567 The workaround is to promote device loads to use Load-Acquire 568 semantics. 569 Please note that this does not necessarily enable the workaround, 570 as it depends on the alternative framework, which will only patch 571 the kernel if an affected CPU is detected. 572 573 If unsure, say Y. 574 575config ARM64_ERRATUM_834220 576 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 577 depends on KVM 578 help 579 This option adds an alternative code sequence to work around ARM 580 erratum 834220 on Cortex-A57 parts up to r1p2. 581 582 Affected Cortex-A57 parts might report a Stage 2 translation 583 fault as the result of a Stage 1 fault for load crossing a 584 page boundary when there is a permission or device memory 585 alignment fault at Stage 1 and a translation fault at Stage 2. 586 587 The workaround is to verify that the Stage 1 translation 588 doesn't generate a fault before handling the Stage 2 fault. 589 Please note that this does not necessarily enable the workaround, 590 as it depends on the alternative framework, which will only patch 591 the kernel if an affected CPU is detected. 592 593 If unsure, say N. 594 595config ARM64_ERRATUM_1742098 596 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 597 depends on COMPAT 598 default y 599 help 600 This option removes the AES hwcap for aarch32 user-space to 601 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 602 603 Affected parts may corrupt the AES state if an interrupt is 604 taken between a pair of AES instructions. These instructions 605 are only present if the cryptography extensions are present. 606 All software should have a fallback implementation for CPUs 607 that don't implement the cryptography extensions. 608 609 If unsure, say Y. 610 611config ARM64_ERRATUM_845719 612 bool "Cortex-A53: 845719: a load might read incorrect data" 613 depends on COMPAT 614 default y 615 help 616 This option adds an alternative code sequence to work around ARM 617 erratum 845719 on Cortex-A53 parts up to r0p4. 618 619 When running a compat (AArch32) userspace on an affected Cortex-A53 620 part, a load at EL0 from a virtual address that matches the bottom 32 621 bits of the virtual address used by a recent load at (AArch64) EL1 622 might return incorrect data. 623 624 The workaround is to write the contextidr_el1 register on exception 625 return to a 32-bit task. 626 Please note that this does not necessarily enable the workaround, 627 as it depends on the alternative framework, which will only patch 628 the kernel if an affected CPU is detected. 629 630 If unsure, say Y. 631 632config ARM64_ERRATUM_843419 633 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 634 default y 635 help 636 This option links the kernel with '--fix-cortex-a53-843419' and 637 enables PLT support to replace certain ADRP instructions, which can 638 cause subsequent memory accesses to use an incorrect address on 639 Cortex-A53 parts up to r0p4. 640 641 If unsure, say Y. 642 643config ARM64_LD_HAS_FIX_ERRATUM_843419 644 def_bool $(ld-option,--fix-cortex-a53-843419) 645 646config ARM64_ERRATUM_1024718 647 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 648 default y 649 help 650 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 651 652 Affected Cortex-A55 cores (all revisions) could cause incorrect 653 update of the hardware dirty bit when the DBM/AP bits are updated 654 without a break-before-make. The workaround is to disable the usage 655 of hardware DBM locally on the affected cores. CPUs not affected by 656 this erratum will continue to use the feature. 657 658 If unsure, say Y. 659 660config ARM64_ERRATUM_1418040 661 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 662 default y 663 depends on COMPAT 664 help 665 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 666 errata 1188873 and 1418040. 667 668 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 669 cause register corruption when accessing the timer registers 670 from AArch32 userspace. 671 672 If unsure, say Y. 673 674config ARM64_WORKAROUND_SPECULATIVE_AT 675 bool 676 677config ARM64_ERRATUM_1165522 678 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 679 default y 680 select ARM64_WORKAROUND_SPECULATIVE_AT 681 help 682 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 683 684 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 685 corrupted TLBs by speculating an AT instruction during a guest 686 context switch. 687 688 If unsure, say Y. 689 690config ARM64_ERRATUM_1319367 691 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 692 default y 693 select ARM64_WORKAROUND_SPECULATIVE_AT 694 help 695 This option adds work arounds for ARM Cortex-A57 erratum 1319537 696 and A72 erratum 1319367 697 698 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 699 speculating an AT instruction during a guest context switch. 700 701 If unsure, say Y. 702 703config ARM64_ERRATUM_1530923 704 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 705 default y 706 select ARM64_WORKAROUND_SPECULATIVE_AT 707 help 708 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 709 710 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 711 corrupted TLBs by speculating an AT instruction during a guest 712 context switch. 713 714 If unsure, say Y. 715 716config ARM64_WORKAROUND_REPEAT_TLBI 717 bool 718 719config ARM64_ERRATUM_2441007 720 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 721 select ARM64_WORKAROUND_REPEAT_TLBI 722 help 723 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 724 725 Under very rare circumstances, affected Cortex-A55 CPUs 726 may not handle a race between a break-before-make sequence on one 727 CPU, and another CPU accessing the same page. This could allow a 728 store to a page that has been unmapped. 729 730 Work around this by adding the affected CPUs to the list that needs 731 TLB sequences to be done twice. 732 733 If unsure, say N. 734 735config ARM64_ERRATUM_1286807 736 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 737 select ARM64_WORKAROUND_REPEAT_TLBI 738 help 739 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 740 741 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 742 address for a cacheable mapping of a location is being 743 accessed by a core while another core is remapping the virtual 744 address to a new physical page using the recommended 745 break-before-make sequence, then under very rare circumstances 746 TLBI+DSB completes before a read using the translation being 747 invalidated has been observed by other observers. The 748 workaround repeats the TLBI+DSB operation. 749 750 If unsure, say N. 751 752config ARM64_ERRATUM_1463225 753 bool "Cortex-A76: Software Step might prevent interrupt recognition" 754 default y 755 help 756 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 757 758 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 759 of a system call instruction (SVC) can prevent recognition of 760 subsequent interrupts when software stepping is disabled in the 761 exception handler of the system call and either kernel debugging 762 is enabled or VHE is in use. 763 764 Work around the erratum by triggering a dummy step exception 765 when handling a system call from a task that is being stepped 766 in a VHE configuration of the kernel. 767 768 If unsure, say Y. 769 770config ARM64_ERRATUM_1542419 771 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 772 help 773 This option adds a workaround for ARM Neoverse-N1 erratum 774 1542419. 775 776 Affected Neoverse-N1 cores could execute a stale instruction when 777 modified by another CPU. The workaround depends on a firmware 778 counterpart. 779 780 Workaround the issue by hiding the DIC feature from EL0. This 781 forces user-space to perform cache maintenance. 782 783 If unsure, say N. 784 785config ARM64_ERRATUM_1508412 786 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 787 default y 788 help 789 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 790 791 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 792 of a store-exclusive or read of PAR_EL1 and a load with device or 793 non-cacheable memory attributes. The workaround depends on a firmware 794 counterpart. 795 796 KVM guests must also have the workaround implemented or they can 797 deadlock the system. 798 799 Work around the issue by inserting DMB SY barriers around PAR_EL1 800 register reads and warning KVM users. The DMB barrier is sufficient 801 to prevent a speculative PAR_EL1 read. 802 803 If unsure, say Y. 804 805config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 806 bool 807 808config ARM64_ERRATUM_2051678 809 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 810 default y 811 help 812 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 813 Affected Cortex-A510 might not respect the ordering rules for 814 hardware update of the page table's dirty bit. The workaround 815 is to not enable the feature on affected CPUs. 816 817 If unsure, say Y. 818 819config ARM64_ERRATUM_2077057 820 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 821 default y 822 help 823 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 824 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 825 expected, but a Pointer Authentication trap is taken instead. The 826 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 827 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 828 829 This can only happen when EL2 is stepping EL1. 830 831 When these conditions occur, the SPSR_EL2 value is unchanged from the 832 previous guest entry, and can be restored from the in-memory copy. 833 834 If unsure, say Y. 835 836config ARM64_ERRATUM_2658417 837 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 838 default y 839 help 840 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 841 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 842 BFMMLA or VMMLA instructions in rare circumstances when a pair of 843 A510 CPUs are using shared neon hardware. As the sharing is not 844 discoverable by the kernel, hide the BF16 HWCAP to indicate that 845 user-space should not be using these instructions. 846 847 If unsure, say Y. 848 849config ARM64_ERRATUM_2119858 850 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 851 default y 852 depends on CORESIGHT_TRBE 853 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 854 help 855 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 856 857 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 858 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 859 the event of a WRAP event. 860 861 Work around the issue by always making sure we move the TRBPTR_EL1 by 862 256 bytes before enabling the buffer and filling the first 256 bytes of 863 the buffer with ETM ignore packets upon disabling. 864 865 If unsure, say Y. 866 867config ARM64_ERRATUM_2139208 868 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 869 default y 870 depends on CORESIGHT_TRBE 871 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 872 help 873 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 874 875 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 876 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 877 the event of a WRAP event. 878 879 Work around the issue by always making sure we move the TRBPTR_EL1 by 880 256 bytes before enabling the buffer and filling the first 256 bytes of 881 the buffer with ETM ignore packets upon disabling. 882 883 If unsure, say Y. 884 885config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 886 bool 887 888config ARM64_ERRATUM_2054223 889 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 890 default y 891 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 892 help 893 Enable workaround for ARM Cortex-A710 erratum 2054223 894 895 Affected cores may fail to flush the trace data on a TSB instruction, when 896 the PE is in trace prohibited state. This will cause losing a few bytes 897 of the trace cached. 898 899 Workaround is to issue two TSB consecutively on affected cores. 900 901 If unsure, say Y. 902 903config ARM64_ERRATUM_2067961 904 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 905 default y 906 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 907 help 908 Enable workaround for ARM Neoverse-N2 erratum 2067961 909 910 Affected cores may fail to flush the trace data on a TSB instruction, when 911 the PE is in trace prohibited state. This will cause losing a few bytes 912 of the trace cached. 913 914 Workaround is to issue two TSB consecutively on affected cores. 915 916 If unsure, say Y. 917 918config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 919 bool 920 921config ARM64_ERRATUM_2253138 922 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 923 depends on CORESIGHT_TRBE 924 default y 925 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 926 help 927 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 928 929 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 930 for TRBE. Under some conditions, the TRBE might generate a write to the next 931 virtually addressed page following the last page of the TRBE address space 932 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 933 934 Work around this in the driver by always making sure that there is a 935 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 936 937 If unsure, say Y. 938 939config ARM64_ERRATUM_2224489 940 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 941 depends on CORESIGHT_TRBE 942 default y 943 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 944 help 945 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 946 947 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 948 for TRBE. Under some conditions, the TRBE might generate a write to the next 949 virtually addressed page following the last page of the TRBE address space 950 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 951 952 Work around this in the driver by always making sure that there is a 953 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 954 955 If unsure, say Y. 956 957config ARM64_ERRATUM_2441009 958 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 959 select ARM64_WORKAROUND_REPEAT_TLBI 960 help 961 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 962 963 Under very rare circumstances, affected Cortex-A510 CPUs 964 may not handle a race between a break-before-make sequence on one 965 CPU, and another CPU accessing the same page. This could allow a 966 store to a page that has been unmapped. 967 968 Work around this by adding the affected CPUs to the list that needs 969 TLB sequences to be done twice. 970 971 If unsure, say N. 972 973config ARM64_ERRATUM_2064142 974 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 975 depends on CORESIGHT_TRBE 976 default y 977 help 978 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 979 980 Affected Cortex-A510 core might fail to write into system registers after the 981 TRBE has been disabled. Under some conditions after the TRBE has been disabled 982 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 983 and TRBTRG_EL1 will be ignored and will not be effected. 984 985 Work around this in the driver by executing TSB CSYNC and DSB after collection 986 is stopped and before performing a system register write to one of the affected 987 registers. 988 989 If unsure, say Y. 990 991config ARM64_ERRATUM_2038923 992 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 993 depends on CORESIGHT_TRBE 994 default y 995 help 996 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 997 998 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 999 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1000 might be corrupted. This happens after TRBE buffer has been enabled by setting 1001 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1002 execution changes from a context, in which trace is prohibited to one where it 1003 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1004 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1005 the trace buffer state might be corrupted. 1006 1007 Work around this in the driver by preventing an inconsistent view of whether the 1008 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1009 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1010 two ISB instructions if no ERET is to take place. 1011 1012 If unsure, say Y. 1013 1014config ARM64_ERRATUM_1902691 1015 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1016 depends on CORESIGHT_TRBE 1017 default y 1018 help 1019 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1020 1021 Affected Cortex-A510 core might cause trace data corruption, when being written 1022 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1023 trace data. 1024 1025 Work around this problem in the driver by just preventing TRBE initialization on 1026 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1027 on such implementations. This will cover the kernel for any firmware that doesn't 1028 do this already. 1029 1030 If unsure, say Y. 1031 1032config ARM64_ERRATUM_2457168 1033 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1034 depends on ARM64_AMU_EXTN 1035 default y 1036 help 1037 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1038 1039 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1040 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1041 incorrectly giving a significantly higher output value. 1042 1043 Work around this problem by returning 0 when reading the affected counter in 1044 key locations that results in disabling all users of this counter. This effect 1045 is the same to firmware disabling affected counters. 1046 1047 If unsure, say Y. 1048 1049config ARM64_ERRATUM_2645198 1050 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1051 default y 1052 help 1053 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1054 1055 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1056 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1057 next instruction abort caused by permission fault. 1058 1059 Only user-space does executable to non-executable permission transition via 1060 mprotect() system call. Workaround the problem by doing a break-before-make 1061 TLB invalidation, for all changes to executable user space mappings. 1062 1063 If unsure, say Y. 1064 1065config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1066 bool 1067 1068config ARM64_ERRATUM_2966298 1069 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1070 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1071 default y 1072 help 1073 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1074 1075 On an affected Cortex-A520 core, a speculatively executed unprivileged 1076 load might leak data from a privileged level via a cache side channel. 1077 1078 Work around this problem by executing a TLBI before returning to EL0. 1079 1080 If unsure, say Y. 1081 1082config ARM64_ERRATUM_3117295 1083 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1084 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1085 default y 1086 help 1087 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1088 1089 On an affected Cortex-A510 core, a speculatively executed unprivileged 1090 load might leak data from a privileged level via a cache side channel. 1091 1092 Work around this problem by executing a TLBI before returning to EL0. 1093 1094 If unsure, say Y. 1095 1096config ARM64_ERRATUM_3194386 1097 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1098 default y 1099 help 1100 This option adds the workaround for the following errata: 1101 1102 * ARM Cortex-A76 erratum 3324349 1103 * ARM Cortex-A77 erratum 3324348 1104 * ARM Cortex-A78 erratum 3324344 1105 * ARM Cortex-A78C erratum 3324346 1106 * ARM Cortex-A78C erratum 3324347 1107 * ARM Cortex-A710 erratam 3324338 1108 * ARM Cortex-A715 errartum 3456084 1109 * ARM Cortex-A720 erratum 3456091 1110 * ARM Cortex-A725 erratum 3456106 1111 * ARM Cortex-X1 erratum 3324344 1112 * ARM Cortex-X1C erratum 3324346 1113 * ARM Cortex-X2 erratum 3324338 1114 * ARM Cortex-X3 erratum 3324335 1115 * ARM Cortex-X4 erratum 3194386 1116 * ARM Cortex-X925 erratum 3324334 1117 * ARM Neoverse-N1 erratum 3324349 1118 * ARM Neoverse N2 erratum 3324339 1119 * ARM Neoverse-N3 erratum 3456111 1120 * ARM Neoverse-V1 erratum 3324341 1121 * ARM Neoverse V2 erratum 3324336 1122 * ARM Neoverse-V3 erratum 3312417 1123 1124 On affected cores "MSR SSBS, #0" instructions may not affect 1125 subsequent speculative instructions, which may permit unexepected 1126 speculative store bypassing. 1127 1128 Work around this problem by placing a Speculation Barrier (SB) or 1129 Instruction Synchronization Barrier (ISB) after kernel changes to 1130 SSBS. The presence of the SSBS special-purpose register is hidden 1131 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1132 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1133 1134 If unsure, say Y. 1135 1136config CAVIUM_ERRATUM_22375 1137 bool "Cavium erratum 22375, 24313" 1138 default y 1139 help 1140 Enable workaround for errata 22375 and 24313. 1141 1142 This implements two gicv3-its errata workarounds for ThunderX. Both 1143 with a small impact affecting only ITS table allocation. 1144 1145 erratum 22375: only alloc 8MB table size 1146 erratum 24313: ignore memory access type 1147 1148 The fixes are in ITS initialization and basically ignore memory access 1149 type and table size provided by the TYPER and BASER registers. 1150 1151 If unsure, say Y. 1152 1153config CAVIUM_ERRATUM_23144 1154 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1155 depends on NUMA 1156 default y 1157 help 1158 ITS SYNC command hang for cross node io and collections/cpu mapping. 1159 1160 If unsure, say Y. 1161 1162config CAVIUM_ERRATUM_23154 1163 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1164 default y 1165 help 1166 The ThunderX GICv3 implementation requires a modified version for 1167 reading the IAR status to ensure data synchronization 1168 (access to icc_iar1_el1 is not sync'ed before and after). 1169 1170 It also suffers from erratum 38545 (also present on Marvell's 1171 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1172 spuriously presented to the CPU interface. 1173 1174 If unsure, say Y. 1175 1176config CAVIUM_ERRATUM_27456 1177 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1178 default y 1179 help 1180 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1181 instructions may cause the icache to become corrupted if it 1182 contains data for a non-current ASID. The fix is to 1183 invalidate the icache when changing the mm context. 1184 1185 If unsure, say Y. 1186 1187config CAVIUM_ERRATUM_30115 1188 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1189 default y 1190 help 1191 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1192 1.2, and T83 Pass 1.0, KVM guest execution may disable 1193 interrupts in host. Trapping both GICv3 group-0 and group-1 1194 accesses sidesteps the issue. 1195 1196 If unsure, say Y. 1197 1198config CAVIUM_TX2_ERRATUM_219 1199 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1200 default y 1201 help 1202 On Cavium ThunderX2, a load, store or prefetch instruction between a 1203 TTBR update and the corresponding context synchronizing operation can 1204 cause a spurious Data Abort to be delivered to any hardware thread in 1205 the CPU core. 1206 1207 Work around the issue by avoiding the problematic code sequence and 1208 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1209 trap handler performs the corresponding register access, skips the 1210 instruction and ensures context synchronization by virtue of the 1211 exception return. 1212 1213 If unsure, say Y. 1214 1215config FUJITSU_ERRATUM_010001 1216 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1217 default y 1218 help 1219 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1220 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1221 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1222 This fault occurs under a specific hardware condition when a 1223 load/store instruction performs an address translation using: 1224 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1225 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1226 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1227 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1228 1229 The workaround is to ensure these bits are clear in TCR_ELx. 1230 The workaround only affects the Fujitsu-A64FX. 1231 1232 If unsure, say Y. 1233 1234config HISILICON_ERRATUM_161600802 1235 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1236 default y 1237 help 1238 The HiSilicon Hip07 SoC uses the wrong redistributor base 1239 when issued ITS commands such as VMOVP and VMAPP, and requires 1240 a 128kB offset to be applied to the target address in this commands. 1241 1242 If unsure, say Y. 1243 1244config HISILICON_ERRATUM_162100801 1245 bool "Hip09 162100801 erratum support" 1246 default y 1247 help 1248 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1249 during unmapping operation, which will cause some vSGIs lost. 1250 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1251 after VMOVP. 1252 1253 If unsure, say Y. 1254 1255config QCOM_FALKOR_ERRATUM_1003 1256 bool "Falkor E1003: Incorrect translation due to ASID change" 1257 default y 1258 help 1259 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1260 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1261 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1262 then only for entries in the walk cache, since the leaf translation 1263 is unchanged. Work around the erratum by invalidating the walk cache 1264 entries for the trampoline before entering the kernel proper. 1265 1266config QCOM_FALKOR_ERRATUM_1009 1267 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1268 default y 1269 select ARM64_WORKAROUND_REPEAT_TLBI 1270 help 1271 On Falkor v1, the CPU may prematurely complete a DSB following a 1272 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1273 one more time to fix the issue. 1274 1275 If unsure, say Y. 1276 1277config QCOM_QDF2400_ERRATUM_0065 1278 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1279 default y 1280 help 1281 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1282 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1283 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1284 1285 If unsure, say Y. 1286 1287config QCOM_FALKOR_ERRATUM_E1041 1288 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1289 default y 1290 help 1291 Falkor CPU may speculatively fetch instructions from an improper 1292 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1293 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1294 1295 If unsure, say Y. 1296 1297config NVIDIA_CARMEL_CNP_ERRATUM 1298 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1299 default y 1300 help 1301 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1302 invalidate shared TLB entries installed by a different core, as it would 1303 on standard ARM cores. 1304 1305 If unsure, say Y. 1306 1307config ROCKCHIP_ERRATUM_3568002 1308 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1309 default y 1310 help 1311 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1312 addressing limited to the first 32bit of physical address space. 1313 1314 If unsure, say Y. 1315 1316config ROCKCHIP_ERRATUM_3588001 1317 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1318 default y 1319 help 1320 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1321 This means, that its sharability feature may not be used, even though it 1322 is supported by the IP itself. 1323 1324 If unsure, say Y. 1325 1326config SOCIONEXT_SYNQUACER_PREITS 1327 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1328 default y 1329 help 1330 Socionext Synquacer SoCs implement a separate h/w block to generate 1331 MSI doorbell writes with non-zero values for the device ID. 1332 1333 If unsure, say Y. 1334 1335endmenu # "ARM errata workarounds via the alternatives framework" 1336 1337choice 1338 prompt "Page size" 1339 default ARM64_4K_PAGES 1340 help 1341 Page size (translation granule) configuration. 1342 1343config ARM64_4K_PAGES 1344 bool "4KB" 1345 select HAVE_PAGE_SIZE_4KB 1346 help 1347 This feature enables 4KB pages support. 1348 1349config ARM64_16K_PAGES 1350 bool "16KB" 1351 select HAVE_PAGE_SIZE_16KB 1352 help 1353 The system will use 16KB pages support. AArch32 emulation 1354 requires applications compiled with 16K (or a multiple of 16K) 1355 aligned segments. 1356 1357config ARM64_64K_PAGES 1358 bool "64KB" 1359 select HAVE_PAGE_SIZE_64KB 1360 help 1361 This feature enables 64KB pages support (4KB by default) 1362 allowing only two levels of page tables and faster TLB 1363 look-up. AArch32 emulation requires applications compiled 1364 with 64K aligned segments. 1365 1366endchoice 1367 1368choice 1369 prompt "Virtual address space size" 1370 default ARM64_VA_BITS_52 1371 help 1372 Allows choosing one of multiple possible virtual address 1373 space sizes. The level of translation table is determined by 1374 a combination of page size and virtual address space size. 1375 1376config ARM64_VA_BITS_36 1377 bool "36-bit" if EXPERT 1378 depends on PAGE_SIZE_16KB 1379 1380config ARM64_VA_BITS_39 1381 bool "39-bit" 1382 depends on PAGE_SIZE_4KB 1383 1384config ARM64_VA_BITS_42 1385 bool "42-bit" 1386 depends on PAGE_SIZE_64KB 1387 1388config ARM64_VA_BITS_47 1389 bool "47-bit" 1390 depends on PAGE_SIZE_16KB 1391 1392config ARM64_VA_BITS_48 1393 bool "48-bit" 1394 1395config ARM64_VA_BITS_52 1396 bool "52-bit" 1397 help 1398 Enable 52-bit virtual addressing for userspace when explicitly 1399 requested via a hint to mmap(). The kernel will also use 52-bit 1400 virtual addresses for its own mappings (provided HW support for 1401 this feature is available, otherwise it reverts to 48-bit). 1402 1403 NOTE: Enabling 52-bit virtual addressing in conjunction with 1404 ARMv8.3 Pointer Authentication will result in the PAC being 1405 reduced from 7 bits to 3 bits, which may have a significant 1406 impact on its susceptibility to brute-force attacks. 1407 1408 If unsure, select 48-bit virtual addressing instead. 1409 1410endchoice 1411 1412config ARM64_FORCE_52BIT 1413 bool "Force 52-bit virtual addresses for userspace" 1414 depends on ARM64_VA_BITS_52 && EXPERT 1415 help 1416 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1417 to maintain compatibility with older software by providing 48-bit VAs 1418 unless a hint is supplied to mmap. 1419 1420 This configuration option disables the 48-bit compatibility logic, and 1421 forces all userspace addresses to be 52-bit on HW that supports it. One 1422 should only enable this configuration option for stress testing userspace 1423 memory management code. If unsure say N here. 1424 1425config ARM64_VA_BITS 1426 int 1427 default 36 if ARM64_VA_BITS_36 1428 default 39 if ARM64_VA_BITS_39 1429 default 42 if ARM64_VA_BITS_42 1430 default 47 if ARM64_VA_BITS_47 1431 default 48 if ARM64_VA_BITS_48 1432 default 52 if ARM64_VA_BITS_52 1433 1434choice 1435 prompt "Physical address space size" 1436 default ARM64_PA_BITS_48 1437 help 1438 Choose the maximum physical address range that the kernel will 1439 support. 1440 1441config ARM64_PA_BITS_48 1442 bool "48-bit" 1443 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1444 1445config ARM64_PA_BITS_52 1446 bool "52-bit" 1447 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1448 help 1449 Enable support for a 52-bit physical address space, introduced as 1450 part of the ARMv8.2-LPA extension. 1451 1452 With this enabled, the kernel will also continue to work on CPUs that 1453 do not support ARMv8.2-LPA, but with some added memory overhead (and 1454 minor performance overhead). 1455 1456endchoice 1457 1458config ARM64_PA_BITS 1459 int 1460 default 48 if ARM64_PA_BITS_48 1461 default 52 if ARM64_PA_BITS_52 1462 1463config ARM64_LPA2 1464 def_bool y 1465 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1466 1467choice 1468 prompt "Endianness" 1469 default CPU_LITTLE_ENDIAN 1470 help 1471 Select the endianness of data accesses performed by the CPU. Userspace 1472 applications will need to be compiled and linked for the endianness 1473 that is selected here. 1474 1475config CPU_BIG_ENDIAN 1476 bool "Build big-endian kernel" 1477 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1478 depends on AS_IS_GNU || AS_VERSION >= 150000 1479 help 1480 Say Y if you plan on running a kernel with a big-endian userspace. 1481 1482config CPU_LITTLE_ENDIAN 1483 bool "Build little-endian kernel" 1484 help 1485 Say Y if you plan on running a kernel with a little-endian userspace. 1486 This is usually the case for distributions targeting arm64. 1487 1488endchoice 1489 1490config SCHED_MC 1491 bool "Multi-core scheduler support" 1492 help 1493 Multi-core scheduler support improves the CPU scheduler's decision 1494 making when dealing with multi-core CPU chips at a cost of slightly 1495 increased overhead in some places. If unsure say N here. 1496 1497config SCHED_CLUSTER 1498 bool "Cluster scheduler support" 1499 help 1500 Cluster scheduler support improves the CPU scheduler's decision 1501 making when dealing with machines that have clusters of CPUs. 1502 Cluster usually means a couple of CPUs which are placed closely 1503 by sharing mid-level caches, last-level cache tags or internal 1504 busses. 1505 1506config SCHED_SMT 1507 bool "SMT scheduler support" 1508 help 1509 Improves the CPU scheduler's decision making when dealing with 1510 MultiThreading at a cost of slightly increased overhead in some 1511 places. If unsure say N here. 1512 1513config NR_CPUS 1514 int "Maximum number of CPUs (2-4096)" 1515 range 2 4096 1516 default "512" 1517 1518config HOTPLUG_CPU 1519 bool "Support for hot-pluggable CPUs" 1520 select GENERIC_IRQ_MIGRATION 1521 help 1522 Say Y here to experiment with turning CPUs off and on. CPUs 1523 can be controlled through /sys/devices/system/cpu. 1524 1525# Common NUMA Features 1526config NUMA 1527 bool "NUMA Memory Allocation and Scheduler Support" 1528 select GENERIC_ARCH_NUMA 1529 select OF_NUMA 1530 select HAVE_SETUP_PER_CPU_AREA 1531 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1532 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1533 select USE_PERCPU_NUMA_NODE_ID 1534 help 1535 Enable NUMA (Non-Uniform Memory Access) support. 1536 1537 The kernel will try to allocate memory used by a CPU on the 1538 local memory of the CPU and add some more 1539 NUMA awareness to the kernel. 1540 1541config NODES_SHIFT 1542 int "Maximum NUMA Nodes (as a power of 2)" 1543 range 1 10 1544 default "4" 1545 depends on NUMA 1546 help 1547 Specify the maximum number of NUMA Nodes available on the target 1548 system. Increases memory reserved to accommodate various tables. 1549 1550source "kernel/Kconfig.hz" 1551 1552config ARCH_SPARSEMEM_ENABLE 1553 def_bool y 1554 select SPARSEMEM_VMEMMAP_ENABLE 1555 select SPARSEMEM_VMEMMAP 1556 1557config HW_PERF_EVENTS 1558 def_bool y 1559 depends on ARM_PMU 1560 1561# Supported by clang >= 7.0 or GCC >= 12.0.0 1562config CC_HAVE_SHADOW_CALL_STACK 1563 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1564 1565config PARAVIRT 1566 bool "Enable paravirtualization code" 1567 help 1568 This changes the kernel so it can modify itself when it is run 1569 under a hypervisor, potentially improving performance significantly 1570 over full virtualization. 1571 1572config PARAVIRT_TIME_ACCOUNTING 1573 bool "Paravirtual steal time accounting" 1574 select PARAVIRT 1575 help 1576 Select this option to enable fine granularity task steal time 1577 accounting. Time spent executing other tasks in parallel with 1578 the current vCPU is discounted from the vCPU power. To account for 1579 that, there can be a small performance impact. 1580 1581 If in doubt, say N here. 1582 1583config ARCH_SUPPORTS_KEXEC 1584 def_bool PM_SLEEP_SMP 1585 1586config ARCH_SUPPORTS_KEXEC_FILE 1587 def_bool y 1588 1589config ARCH_SELECTS_KEXEC_FILE 1590 def_bool y 1591 depends on KEXEC_FILE 1592 select HAVE_IMA_KEXEC if IMA 1593 1594config ARCH_SUPPORTS_KEXEC_SIG 1595 def_bool y 1596 1597config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1598 def_bool y 1599 1600config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1601 def_bool y 1602 1603config ARCH_SUPPORTS_CRASH_DUMP 1604 def_bool y 1605 1606config ARCH_DEFAULT_CRASH_DUMP 1607 def_bool y 1608 1609config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1610 def_bool CRASH_RESERVE 1611 1612config TRANS_TABLE 1613 def_bool y 1614 depends on HIBERNATION || KEXEC_CORE 1615 1616config XEN_DOM0 1617 def_bool y 1618 depends on XEN 1619 1620config XEN 1621 bool "Xen guest support on ARM64" 1622 depends on ARM64 && OF 1623 select SWIOTLB_XEN 1624 select PARAVIRT 1625 help 1626 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1627 1628# include/linux/mmzone.h requires the following to be true: 1629# 1630# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1631# 1632# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1633# 1634# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1635# ----+-------------------+--------------+----------------------+-------------------------+ 1636# 4K | 27 | 12 | 15 | 10 | 1637# 16K | 27 | 14 | 13 | 11 | 1638# 64K | 29 | 16 | 13 | 13 | 1639config ARCH_FORCE_MAX_ORDER 1640 int 1641 default "13" if ARM64_64K_PAGES 1642 default "11" if ARM64_16K_PAGES 1643 default "10" 1644 help 1645 The kernel page allocator limits the size of maximal physically 1646 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1647 defines the maximal power of two of number of pages that can be 1648 allocated as a single contiguous block. This option allows 1649 overriding the default setting when ability to allocate very 1650 large blocks of physically contiguous memory is required. 1651 1652 The maximal size of allocation cannot exceed the size of the 1653 section, so the value of MAX_PAGE_ORDER should satisfy 1654 1655 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1656 1657 Don't change if unsure. 1658 1659config UNMAP_KERNEL_AT_EL0 1660 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1661 default y 1662 help 1663 Speculation attacks against some high-performance processors can 1664 be used to bypass MMU permission checks and leak kernel data to 1665 userspace. This can be defended against by unmapping the kernel 1666 when running in userspace, mapping it back in on exception entry 1667 via a trampoline page in the vector table. 1668 1669 If unsure, say Y. 1670 1671config MITIGATE_SPECTRE_BRANCH_HISTORY 1672 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1673 default y 1674 help 1675 Speculation attacks against some high-performance processors can 1676 make use of branch history to influence future speculation. 1677 When taking an exception from user-space, a sequence of branches 1678 or a firmware call overwrites the branch history. 1679 1680config RODATA_FULL_DEFAULT_ENABLED 1681 bool "Apply r/o permissions of VM areas also to their linear aliases" 1682 default y 1683 help 1684 Apply read-only attributes of VM areas to the linear alias of 1685 the backing pages as well. This prevents code or read-only data 1686 from being modified (inadvertently or intentionally) via another 1687 mapping of the same memory page. This additional enhancement can 1688 be turned off at runtime by passing rodata=[off|on] (and turned on 1689 with rodata=full if this option is set to 'n') 1690 1691 This requires the linear region to be mapped down to pages, 1692 which may adversely affect performance in some cases. 1693 1694config ARM64_SW_TTBR0_PAN 1695 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1696 depends on !KCSAN 1697 select ARM64_PAN 1698 help 1699 Enabling this option prevents the kernel from accessing 1700 user-space memory directly by pointing TTBR0_EL1 to a reserved 1701 zeroed area and reserved ASID. The user access routines 1702 restore the valid TTBR0_EL1 temporarily. 1703 1704config ARM64_TAGGED_ADDR_ABI 1705 bool "Enable the tagged user addresses syscall ABI" 1706 default y 1707 help 1708 When this option is enabled, user applications can opt in to a 1709 relaxed ABI via prctl() allowing tagged addresses to be passed 1710 to system calls as pointer arguments. For details, see 1711 Documentation/arch/arm64/tagged-address-abi.rst. 1712 1713menuconfig COMPAT 1714 bool "Kernel support for 32-bit EL0" 1715 depends on ARM64_4K_PAGES || EXPERT 1716 select HAVE_UID16 1717 select OLD_SIGSUSPEND3 1718 select COMPAT_OLD_SIGACTION 1719 help 1720 This option enables support for a 32-bit EL0 running under a 64-bit 1721 kernel at EL1. AArch32-specific components such as system calls, 1722 the user helper functions, VFP support and the ptrace interface are 1723 handled appropriately by the kernel. 1724 1725 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1726 that you will only be able to execute AArch32 binaries that were compiled 1727 with page size aligned segments. 1728 1729 If you want to execute 32-bit userspace applications, say Y. 1730 1731if COMPAT 1732 1733config KUSER_HELPERS 1734 bool "Enable kuser helpers page for 32-bit applications" 1735 default y 1736 help 1737 Warning: disabling this option may break 32-bit user programs. 1738 1739 Provide kuser helpers to compat tasks. The kernel provides 1740 helper code to userspace in read only form at a fixed location 1741 to allow userspace to be independent of the CPU type fitted to 1742 the system. This permits binaries to be run on ARMv4 through 1743 to ARMv8 without modification. 1744 1745 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1746 1747 However, the fixed address nature of these helpers can be used 1748 by ROP (return orientated programming) authors when creating 1749 exploits. 1750 1751 If all of the binaries and libraries which run on your platform 1752 are built specifically for your platform, and make no use of 1753 these helpers, then you can turn this option off to hinder 1754 such exploits. However, in that case, if a binary or library 1755 relying on those helpers is run, it will not function correctly. 1756 1757 Say N here only if you are absolutely certain that you do not 1758 need these helpers; otherwise, the safe option is to say Y. 1759 1760config COMPAT_VDSO 1761 bool "Enable vDSO for 32-bit applications" 1762 depends on !CPU_BIG_ENDIAN 1763 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1764 select GENERIC_COMPAT_VDSO 1765 default y 1766 help 1767 Place in the process address space of 32-bit applications an 1768 ELF shared object providing fast implementations of gettimeofday 1769 and clock_gettime. 1770 1771 You must have a 32-bit build of glibc 2.22 or later for programs 1772 to seamlessly take advantage of this. 1773 1774config THUMB2_COMPAT_VDSO 1775 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1776 depends on COMPAT_VDSO 1777 default y 1778 help 1779 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1780 otherwise with '-marm'. 1781 1782config COMPAT_ALIGNMENT_FIXUPS 1783 bool "Fix up misaligned multi-word loads and stores in user space" 1784 1785menuconfig ARMV8_DEPRECATED 1786 bool "Emulate deprecated/obsolete ARMv8 instructions" 1787 depends on SYSCTL 1788 help 1789 Legacy software support may require certain instructions 1790 that have been deprecated or obsoleted in the architecture. 1791 1792 Enable this config to enable selective emulation of these 1793 features. 1794 1795 If unsure, say Y 1796 1797if ARMV8_DEPRECATED 1798 1799config SWP_EMULATION 1800 bool "Emulate SWP/SWPB instructions" 1801 help 1802 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1803 they are always undefined. Say Y here to enable software 1804 emulation of these instructions for userspace using LDXR/STXR. 1805 This feature can be controlled at runtime with the abi.swp 1806 sysctl which is disabled by default. 1807 1808 In some older versions of glibc [<=2.8] SWP is used during futex 1809 trylock() operations with the assumption that the code will not 1810 be preempted. This invalid assumption may be more likely to fail 1811 with SWP emulation enabled, leading to deadlock of the user 1812 application. 1813 1814 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1815 on an external transaction monitoring block called a global 1816 monitor to maintain update atomicity. If your system does not 1817 implement a global monitor, this option can cause programs that 1818 perform SWP operations to uncached memory to deadlock. 1819 1820 If unsure, say Y 1821 1822config CP15_BARRIER_EMULATION 1823 bool "Emulate CP15 Barrier instructions" 1824 help 1825 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1826 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1827 strongly recommended to use the ISB, DSB, and DMB 1828 instructions instead. 1829 1830 Say Y here to enable software emulation of these 1831 instructions for AArch32 userspace code. When this option is 1832 enabled, CP15 barrier usage is traced which can help 1833 identify software that needs updating. This feature can be 1834 controlled at runtime with the abi.cp15_barrier sysctl. 1835 1836 If unsure, say Y 1837 1838config SETEND_EMULATION 1839 bool "Emulate SETEND instruction" 1840 help 1841 The SETEND instruction alters the data-endianness of the 1842 AArch32 EL0, and is deprecated in ARMv8. 1843 1844 Say Y here to enable software emulation of the instruction 1845 for AArch32 userspace code. This feature can be controlled 1846 at runtime with the abi.setend sysctl. 1847 1848 Note: All the cpus on the system must have mixed endian support at EL0 1849 for this feature to be enabled. If a new CPU - which doesn't support mixed 1850 endian - is hotplugged in after this feature has been enabled, there could 1851 be unexpected results in the applications. 1852 1853 If unsure, say Y 1854endif # ARMV8_DEPRECATED 1855 1856endif # COMPAT 1857 1858menu "ARMv8.1 architectural features" 1859 1860config ARM64_HW_AFDBM 1861 bool "Support for hardware updates of the Access and Dirty page flags" 1862 default y 1863 help 1864 The ARMv8.1 architecture extensions introduce support for 1865 hardware updates of the access and dirty information in page 1866 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1867 capable processors, accesses to pages with PTE_AF cleared will 1868 set this bit instead of raising an access flag fault. 1869 Similarly, writes to read-only pages with the DBM bit set will 1870 clear the read-only bit (AP[2]) instead of raising a 1871 permission fault. 1872 1873 Kernels built with this configuration option enabled continue 1874 to work on pre-ARMv8.1 hardware and the performance impact is 1875 minimal. If unsure, say Y. 1876 1877config ARM64_PAN 1878 bool "Enable support for Privileged Access Never (PAN)" 1879 default y 1880 help 1881 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1882 prevents the kernel or hypervisor from accessing user-space (EL0) 1883 memory directly. 1884 1885 Choosing this option will cause any unprotected (not using 1886 copy_to_user et al) memory access to fail with a permission fault. 1887 1888 The feature is detected at runtime, and will remain as a 'nop' 1889 instruction if the cpu does not implement the feature. 1890 1891config AS_HAS_LSE_ATOMICS 1892 def_bool $(as-instr,.arch_extension lse) 1893 1894config ARM64_LSE_ATOMICS 1895 bool 1896 default ARM64_USE_LSE_ATOMICS 1897 depends on AS_HAS_LSE_ATOMICS 1898 1899config ARM64_USE_LSE_ATOMICS 1900 bool "Atomic instructions" 1901 default y 1902 help 1903 As part of the Large System Extensions, ARMv8.1 introduces new 1904 atomic instructions that are designed specifically to scale in 1905 very large systems. 1906 1907 Say Y here to make use of these instructions for the in-kernel 1908 atomic routines. This incurs a small overhead on CPUs that do 1909 not support these instructions and requires the kernel to be 1910 built with binutils >= 2.25 in order for the new instructions 1911 to be used. 1912 1913endmenu # "ARMv8.1 architectural features" 1914 1915menu "ARMv8.2 architectural features" 1916 1917config AS_HAS_ARMV8_2 1918 def_bool $(cc-option,-Wa$(comma)-march=armv8.2-a) 1919 1920config AS_HAS_SHA3 1921 def_bool $(as-instr,.arch armv8.2-a+sha3) 1922 1923config ARM64_PMEM 1924 bool "Enable support for persistent memory" 1925 select ARCH_HAS_PMEM_API 1926 select ARCH_HAS_UACCESS_FLUSHCACHE 1927 help 1928 Say Y to enable support for the persistent memory API based on the 1929 ARMv8.2 DCPoP feature. 1930 1931 The feature is detected at runtime, and the kernel will use DC CVAC 1932 operations if DC CVAP is not supported (following the behaviour of 1933 DC CVAP itself if the system does not define a point of persistence). 1934 1935config ARM64_RAS_EXTN 1936 bool "Enable support for RAS CPU Extensions" 1937 default y 1938 help 1939 CPUs that support the Reliability, Availability and Serviceability 1940 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1941 errors, classify them and report them to software. 1942 1943 On CPUs with these extensions system software can use additional 1944 barriers to determine if faults are pending and read the 1945 classification from a new set of registers. 1946 1947 Selecting this feature will allow the kernel to use these barriers 1948 and access the new registers if the system supports the extension. 1949 Platform RAS features may additionally depend on firmware support. 1950 1951config ARM64_CNP 1952 bool "Enable support for Common Not Private (CNP) translations" 1953 default y 1954 help 1955 Common Not Private (CNP) allows translation table entries to 1956 be shared between different PEs in the same inner shareable 1957 domain, so the hardware can use this fact to optimise the 1958 caching of such entries in the TLB. 1959 1960 Selecting this option allows the CNP feature to be detected 1961 at runtime, and does not affect PEs that do not implement 1962 this feature. 1963 1964endmenu # "ARMv8.2 architectural features" 1965 1966menu "ARMv8.3 architectural features" 1967 1968config ARM64_PTR_AUTH 1969 bool "Enable support for pointer authentication" 1970 default y 1971 help 1972 Pointer authentication (part of the ARMv8.3 Extensions) provides 1973 instructions for signing and authenticating pointers against secret 1974 keys, which can be used to mitigate Return Oriented Programming (ROP) 1975 and other attacks. 1976 1977 This option enables these instructions at EL0 (i.e. for userspace). 1978 Choosing this option will cause the kernel to initialise secret keys 1979 for each process at exec() time, with these keys being 1980 context-switched along with the process. 1981 1982 The feature is detected at runtime. If the feature is not present in 1983 hardware it will not be advertised to userspace/KVM guest nor will it 1984 be enabled. 1985 1986 If the feature is present on the boot CPU but not on a late CPU, then 1987 the late CPU will be parked. Also, if the boot CPU does not have 1988 address auth and the late CPU has then the late CPU will still boot 1989 but with the feature disabled. On such a system, this option should 1990 not be selected. 1991 1992config ARM64_PTR_AUTH_KERNEL 1993 bool "Use pointer authentication for kernel" 1994 default y 1995 depends on ARM64_PTR_AUTH 1996 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 1997 # Modern compilers insert a .note.gnu.property section note for PAC 1998 # which is only understood by binutils starting with version 2.33.1. 1999 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2000 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2001 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2002 help 2003 If the compiler supports the -mbranch-protection or 2004 -msign-return-address flag (e.g. GCC 7 or later), then this option 2005 will cause the kernel itself to be compiled with return address 2006 protection. In this case, and if the target hardware is known to 2007 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2008 disabled with minimal loss of protection. 2009 2010 This feature works with FUNCTION_GRAPH_TRACER option only if 2011 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2012 2013config CC_HAS_BRANCH_PROT_PAC_RET 2014 # GCC 9 or later, clang 8 or later 2015 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2016 2017config CC_HAS_SIGN_RETURN_ADDRESS 2018 # GCC 7, 8 2019 def_bool $(cc-option,-msign-return-address=all) 2020 2021config AS_HAS_ARMV8_3 2022 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 2023 2024config AS_HAS_CFI_NEGATE_RA_STATE 2025 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2026 2027config AS_HAS_LDAPR 2028 def_bool $(as-instr,.arch_extension rcpc) 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 AS_HAS_ARMV8_4 2058 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 2059 2060config ARM64_TLB_RANGE 2061 bool "Enable support for tlbi range feature" 2062 default y 2063 depends on AS_HAS_ARMV8_4 2064 help 2065 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2066 range of input addresses. 2067 2068 The feature introduces new assembly instructions, and they were 2069 support when binutils >= 2.30. 2070 2071endmenu # "ARMv8.4 architectural features" 2072 2073menu "ARMv8.5 architectural features" 2074 2075config AS_HAS_ARMV8_5 2076 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2077 2078config ARM64_BTI 2079 bool "Branch Target Identification support" 2080 default y 2081 help 2082 Branch Target Identification (part of the ARMv8.5 Extensions) 2083 provides a mechanism to limit the set of locations to which computed 2084 branch instructions such as BR or BLR can jump. 2085 2086 To make use of BTI on CPUs that support it, say Y. 2087 2088 BTI is intended to provide complementary protection to other control 2089 flow integrity protection mechanisms, such as the Pointer 2090 authentication mechanism provided as part of the ARMv8.3 Extensions. 2091 For this reason, it does not make sense to enable this option without 2092 also enabling support for pointer authentication. Thus, when 2093 enabling this option you should also select ARM64_PTR_AUTH=y. 2094 2095 Userspace binaries must also be specifically compiled to make use of 2096 this mechanism. If you say N here or the hardware does not support 2097 BTI, such binaries can still run, but you get no additional 2098 enforcement of branch destinations. 2099 2100config ARM64_BTI_KERNEL 2101 bool "Use Branch Target Identification for kernel" 2102 default y 2103 depends on ARM64_BTI 2104 depends on ARM64_PTR_AUTH_KERNEL 2105 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2106 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2107 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2108 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2109 depends on !CC_IS_GCC 2110 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2111 help 2112 Build the kernel with Branch Target Identification annotations 2113 and enable enforcement of this for kernel code. When this option 2114 is enabled and the system supports BTI all kernel code including 2115 modular code must have BTI enabled. 2116 2117config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2118 # GCC 9 or later, clang 8 or later 2119 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2120 2121config ARM64_E0PD 2122 bool "Enable support for E0PD" 2123 default y 2124 help 2125 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2126 that EL0 accesses made via TTBR1 always fault in constant time, 2127 providing similar benefits to KASLR as those provided by KPTI, but 2128 with lower overhead and without disrupting legitimate access to 2129 kernel memory such as SPE. 2130 2131 This option enables E0PD for TTBR1 where available. 2132 2133config ARM64_AS_HAS_MTE 2134 # Initial support for MTE went in binutils 2.32.0, checked with 2135 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2136 # as a late addition to the final architecture spec (LDGM/STGM) 2137 # is only supported in the newer 2.32.x and 2.33 binutils 2138 # versions, hence the extra "stgm" instruction check below. 2139 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2140 2141config ARM64_MTE 2142 bool "Memory Tagging Extension support" 2143 default y 2144 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2145 depends on AS_HAS_ARMV8_5 2146 depends on AS_HAS_LSE_ATOMICS 2147 # Required for tag checking in the uaccess routines 2148 select ARM64_PAN 2149 select ARCH_HAS_SUBPAGE_FAULTS 2150 select ARCH_USES_HIGH_VMA_FLAGS 2151 select ARCH_USES_PG_ARCH_2 2152 select ARCH_USES_PG_ARCH_3 2153 help 2154 Memory Tagging (part of the ARMv8.5 Extensions) provides 2155 architectural support for run-time, always-on detection of 2156 various classes of memory error to aid with software debugging 2157 to eliminate vulnerabilities arising from memory-unsafe 2158 languages. 2159 2160 This option enables the support for the Memory Tagging 2161 Extension at EL0 (i.e. for userspace). 2162 2163 Selecting this option allows the feature to be detected at 2164 runtime. Any secondary CPU not implementing this feature will 2165 not be allowed a late bring-up. 2166 2167 Userspace binaries that want to use this feature must 2168 explicitly opt in. The mechanism for the userspace is 2169 described in: 2170 2171 Documentation/arch/arm64/memory-tagging-extension.rst. 2172 2173endmenu # "ARMv8.5 architectural features" 2174 2175menu "ARMv8.7 architectural features" 2176 2177config ARM64_EPAN 2178 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2179 default y 2180 depends on ARM64_PAN 2181 help 2182 Enhanced Privileged Access Never (EPAN) allows Privileged 2183 Access Never to be used with Execute-only mappings. 2184 2185 The feature is detected at runtime, and will remain disabled 2186 if the cpu does not implement the feature. 2187endmenu # "ARMv8.7 architectural features" 2188 2189config AS_HAS_MOPS 2190 def_bool $(as-instr,.arch_extension mops) 2191 2192menu "ARMv8.9 architectural features" 2193 2194config ARM64_POE 2195 prompt "Permission Overlay Extension" 2196 def_bool y 2197 select ARCH_USES_HIGH_VMA_FLAGS 2198 select ARCH_HAS_PKEYS 2199 help 2200 The Permission Overlay Extension is used to implement Memory 2201 Protection Keys. Memory Protection Keys provides a mechanism for 2202 enforcing page-based protections, but without requiring modification 2203 of the page tables when an application changes protection domains. 2204 2205 For details, see Documentation/core-api/protection-keys.rst 2206 2207 If unsure, say y. 2208 2209config ARCH_PKEY_BITS 2210 int 2211 default 3 2212 2213config ARM64_HAFT 2214 bool "Support for Hardware managed Access Flag for Table Descriptors" 2215 depends on ARM64_HW_AFDBM 2216 default y 2217 help 2218 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2219 Flag for Table descriptors. When enabled an architectural executed 2220 memory access will update the Access Flag in each Table descriptor 2221 which is accessed during the translation table walk and for which 2222 the Access Flag is 0. The Access Flag of the Table descriptor use 2223 the same bit of PTE_AF. 2224 2225 The feature will only be enabled if all the CPUs in the system 2226 support this feature. If unsure, say Y. 2227 2228endmenu # "ARMv8.9 architectural features" 2229 2230menu "v9.4 architectural features" 2231 2232config ARM64_GCS 2233 bool "Enable support for Guarded Control Stack (GCS)" 2234 default y 2235 select ARCH_HAS_USER_SHADOW_STACK 2236 select ARCH_USES_HIGH_VMA_FLAGS 2237 depends on !UPROBES 2238 help 2239 Guarded Control Stack (GCS) provides support for a separate 2240 stack with restricted access which contains only return 2241 addresses. This can be used to harden against some attacks 2242 by comparing return address used by the program with what is 2243 stored in the GCS, and may also be used to efficiently obtain 2244 the call stack for applications such as profiling. 2245 2246 The feature is detected at runtime, and will remain disabled 2247 if the system does not implement the feature. 2248 2249endmenu # "v9.4 architectural features" 2250 2251config ARM64_SVE 2252 bool "ARM Scalable Vector Extension support" 2253 default y 2254 help 2255 The Scalable Vector Extension (SVE) is an extension to the AArch64 2256 execution state which complements and extends the SIMD functionality 2257 of the base architecture to support much larger vectors and to enable 2258 additional vectorisation opportunities. 2259 2260 To enable use of this extension on CPUs that implement it, say Y. 2261 2262 On CPUs that support the SVE2 extensions, this option will enable 2263 those too. 2264 2265 Note that for architectural reasons, firmware _must_ implement SVE 2266 support when running on SVE capable hardware. The required support 2267 is present in: 2268 2269 * version 1.5 and later of the ARM Trusted Firmware 2270 * the AArch64 boot wrapper since commit 5e1261e08abf 2271 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2272 2273 For other firmware implementations, consult the firmware documentation 2274 or vendor. 2275 2276 If you need the kernel to boot on SVE-capable hardware with broken 2277 firmware, you may need to say N here until you get your firmware 2278 fixed. Otherwise, you may experience firmware panics or lockups when 2279 booting the kernel. If unsure and you are not observing these 2280 symptoms, you should assume that it is safe to say Y. 2281 2282config ARM64_SME 2283 bool "ARM Scalable Matrix Extension support" 2284 default y 2285 depends on ARM64_SVE 2286 depends on BROKEN 2287 help 2288 The Scalable Matrix Extension (SME) is an extension to the AArch64 2289 execution state which utilises a substantial subset of the SVE 2290 instruction set, together with the addition of new architectural 2291 register state capable of holding two dimensional matrix tiles to 2292 enable various matrix operations. 2293 2294config ARM64_PSEUDO_NMI 2295 bool "Support for NMI-like interrupts" 2296 select ARM_GIC_V3 2297 help 2298 Adds support for mimicking Non-Maskable Interrupts through the use of 2299 GIC interrupt priority. This support requires version 3 or later of 2300 ARM GIC. 2301 2302 This high priority configuration for interrupts needs to be 2303 explicitly enabled by setting the kernel parameter 2304 "irqchip.gicv3_pseudo_nmi" to 1. 2305 2306 If unsure, say N 2307 2308if ARM64_PSEUDO_NMI 2309config ARM64_DEBUG_PRIORITY_MASKING 2310 bool "Debug interrupt priority masking" 2311 help 2312 This adds runtime checks to functions enabling/disabling 2313 interrupts when using priority masking. The additional checks verify 2314 the validity of ICC_PMR_EL1 when calling concerned functions. 2315 2316 If unsure, say N 2317endif # ARM64_PSEUDO_NMI 2318 2319config RELOCATABLE 2320 bool "Build a relocatable kernel image" if EXPERT 2321 select ARCH_HAS_RELR 2322 default y 2323 help 2324 This builds the kernel as a Position Independent Executable (PIE), 2325 which retains all relocation metadata required to relocate the 2326 kernel binary at runtime to a different virtual address than the 2327 address it was linked at. 2328 Since AArch64 uses the RELA relocation format, this requires a 2329 relocation pass at runtime even if the kernel is loaded at the 2330 same address it was linked at. 2331 2332config RANDOMIZE_BASE 2333 bool "Randomize the address of the kernel image" 2334 select RELOCATABLE 2335 help 2336 Randomizes the virtual address at which the kernel image is 2337 loaded, as a security feature that deters exploit attempts 2338 relying on knowledge of the location of kernel internals. 2339 2340 It is the bootloader's job to provide entropy, by passing a 2341 random u64 value in /chosen/kaslr-seed at kernel entry. 2342 2343 When booting via the UEFI stub, it will invoke the firmware's 2344 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2345 to the kernel proper. In addition, it will randomise the physical 2346 location of the kernel Image as well. 2347 2348 If unsure, say N. 2349 2350config RANDOMIZE_MODULE_REGION_FULL 2351 bool "Randomize the module region over a 2 GB range" 2352 depends on RANDOMIZE_BASE 2353 default y 2354 help 2355 Randomizes the location of the module region inside a 2 GB window 2356 covering the core kernel. This way, it is less likely for modules 2357 to leak information about the location of core kernel data structures 2358 but it does imply that function calls between modules and the core 2359 kernel will need to be resolved via veneers in the module PLT. 2360 2361 When this option is not set, the module region will be randomized over 2362 a limited range that contains the [_stext, _etext] interval of the 2363 core kernel, so branch relocations are almost always in range unless 2364 the region is exhausted. In this particular case of region 2365 exhaustion, modules might be able to fall back to a larger 2GB area. 2366 2367config CC_HAVE_STACKPROTECTOR_SYSREG 2368 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2369 2370config STACKPROTECTOR_PER_TASK 2371 def_bool y 2372 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2373 2374config UNWIND_PATCH_PAC_INTO_SCS 2375 bool "Enable shadow call stack dynamically using code patching" 2376 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2377 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2378 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2379 depends on SHADOW_CALL_STACK 2380 select UNWIND_TABLES 2381 select DYNAMIC_SCS 2382 2383config ARM64_CONTPTE 2384 bool "Contiguous PTE mappings for user memory" if EXPERT 2385 depends on TRANSPARENT_HUGEPAGE 2386 default y 2387 help 2388 When enabled, user mappings are configured using the PTE contiguous 2389 bit, for any mappings that meet the size and alignment requirements. 2390 This reduces TLB pressure and improves performance. 2391 2392endmenu # "Kernel Features" 2393 2394menu "Boot options" 2395 2396config ARM64_ACPI_PARKING_PROTOCOL 2397 bool "Enable support for the ARM64 ACPI parking protocol" 2398 depends on ACPI 2399 help 2400 Enable support for the ARM64 ACPI parking protocol. If disabled 2401 the kernel will not allow booting through the ARM64 ACPI parking 2402 protocol even if the corresponding data is present in the ACPI 2403 MADT table. 2404 2405config CMDLINE 2406 string "Default kernel command string" 2407 default "" 2408 help 2409 Provide a set of default command-line options at build time by 2410 entering them here. As a minimum, you should specify the the 2411 root device (e.g. root=/dev/nfs). 2412 2413choice 2414 prompt "Kernel command line type" 2415 depends on CMDLINE != "" 2416 default CMDLINE_FROM_BOOTLOADER 2417 help 2418 Choose how the kernel will handle the provided default kernel 2419 command line string. 2420 2421config CMDLINE_FROM_BOOTLOADER 2422 bool "Use bootloader kernel arguments if available" 2423 help 2424 Uses the command-line options passed by the boot loader. If 2425 the boot loader doesn't provide any, the default kernel command 2426 string provided in CMDLINE will be used. 2427 2428config CMDLINE_FORCE 2429 bool "Always use the default kernel command string" 2430 help 2431 Always use the default kernel command string, even if the boot 2432 loader passes other arguments to the kernel. 2433 This is useful if you cannot or don't want to change the 2434 command-line options your boot loader passes to the kernel. 2435 2436endchoice 2437 2438config EFI_STUB 2439 bool 2440 2441config EFI 2442 bool "UEFI runtime support" 2443 depends on OF && !CPU_BIG_ENDIAN 2444 depends on KERNEL_MODE_NEON 2445 select ARCH_SUPPORTS_ACPI 2446 select LIBFDT 2447 select UCS2_STRING 2448 select EFI_PARAMS_FROM_FDT 2449 select EFI_RUNTIME_WRAPPERS 2450 select EFI_STUB 2451 select EFI_GENERIC_STUB 2452 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2453 default y 2454 help 2455 This option provides support for runtime services provided 2456 by UEFI firmware (such as non-volatile variables, realtime 2457 clock, and platform reset). A UEFI stub is also provided to 2458 allow the kernel to be booted as an EFI application. This 2459 is only useful on systems that have UEFI firmware. 2460 2461config COMPRESSED_INSTALL 2462 bool "Install compressed image by default" 2463 help 2464 This makes the regular "make install" install the compressed 2465 image we built, not the legacy uncompressed one. 2466 2467 You can check that a compressed image works for you by doing 2468 "make zinstall" first, and verifying that everything is fine 2469 in your environment before making "make install" do this for 2470 you. 2471 2472config DMI 2473 bool "Enable support for SMBIOS (DMI) tables" 2474 depends on EFI 2475 default y 2476 help 2477 This enables SMBIOS/DMI feature for systems. 2478 2479 This option is only useful on systems that have UEFI firmware. 2480 However, even with this option, the resultant kernel should 2481 continue to boot on existing non-UEFI platforms. 2482 2483endmenu # "Boot options" 2484 2485menu "Power management options" 2486 2487source "kernel/power/Kconfig" 2488 2489config ARCH_HIBERNATION_POSSIBLE 2490 def_bool y 2491 depends on CPU_PM 2492 2493config ARCH_HIBERNATION_HEADER 2494 def_bool y 2495 depends on HIBERNATION 2496 2497config ARCH_SUSPEND_POSSIBLE 2498 def_bool y 2499 2500endmenu # "Power management options" 2501 2502menu "CPU Power Management" 2503 2504source "drivers/cpuidle/Kconfig" 2505 2506source "drivers/cpufreq/Kconfig" 2507 2508endmenu # "CPU Power Management" 2509 2510source "drivers/acpi/Kconfig" 2511 2512source "arch/arm64/kvm/Kconfig" 2513 2514