1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CRC32 25 select ARCH_HAS_CRC_T10DIF if KERNEL_MODE_NEON 26 select ARCH_HAS_CURRENT_STACK_POINTER 27 select ARCH_HAS_DEBUG_VIRTUAL 28 select ARCH_HAS_DEBUG_VM_PGTABLE 29 select ARCH_HAS_DMA_OPS if XEN 30 select ARCH_HAS_DMA_PREP_COHERENT 31 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 32 select ARCH_HAS_FAST_MULTIPLIER 33 select ARCH_HAS_FORTIFY_SOURCE 34 select ARCH_HAS_GCOV_PROFILE_ALL 35 select ARCH_HAS_GIGANTIC_PAGE 36 select ARCH_HAS_KCOV 37 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 38 select ARCH_HAS_KEEPINITRD 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MEM_ENCRYPT 41 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 42 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 45 select ARCH_HAS_PTDUMP 46 select ARCH_HAS_PTE_DEVMAP 47 select ARCH_HAS_PTE_SPECIAL 48 select ARCH_HAS_HW_PTE_YOUNG 49 select ARCH_HAS_SETUP_DMA_OPS 50 select ARCH_HAS_SET_DIRECT_MAP 51 select ARCH_HAS_SET_MEMORY 52 select ARCH_HAS_MEM_ENCRYPT 53 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 54 select ARCH_STACKWALK 55 select ARCH_HAS_STRICT_KERNEL_RWX 56 select ARCH_HAS_STRICT_MODULE_RWX 57 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 58 select ARCH_HAS_SYNC_DMA_FOR_CPU 59 select ARCH_HAS_SYSCALL_WRAPPER 60 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 61 select ARCH_HAS_ZONE_DMA_SET if EXPERT 62 select ARCH_HAVE_ELF_PROT 63 select ARCH_HAVE_NMI_SAFE_CMPXCHG 64 select ARCH_HAVE_TRACE_MMIO_ACCESS 65 select ARCH_INLINE_READ_LOCK if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 67 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 68 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 71 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 72 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 75 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 76 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 79 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 80 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 81 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 82 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 85 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 86 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 89 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 90 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 91 select ARCH_KEEP_MEMBLOCK 92 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 93 select ARCH_USE_CMPXCHG_LOCKREF 94 select ARCH_USE_GNU_PROPERTY 95 select ARCH_USE_MEMTEST 96 select ARCH_USE_QUEUED_RWLOCKS 97 select ARCH_USE_QUEUED_SPINLOCKS 98 select ARCH_USE_SYM_ANNOTATIONS 99 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 100 select ARCH_SUPPORTS_HUGETLBFS 101 select ARCH_SUPPORTS_MEMORY_FAILURE 102 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 103 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 104 select ARCH_SUPPORTS_LTO_CLANG_THIN 105 select ARCH_SUPPORTS_CFI_CLANG 106 select ARCH_SUPPORTS_ATOMIC_RMW 107 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 108 select ARCH_SUPPORTS_NUMA_BALANCING 109 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 110 select ARCH_SUPPORTS_PER_VMA_LOCK 111 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 112 select ARCH_SUPPORTS_RT 113 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 114 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 115 select ARCH_WANT_DEFAULT_BPF_JIT 116 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 117 select ARCH_WANT_FRAME_POINTERS 118 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 119 select ARCH_WANT_LD_ORPHAN_WARN 120 select ARCH_WANTS_EXECMEM_LATE 121 select ARCH_WANTS_NO_INSTR 122 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 123 select ARCH_HAS_UBSAN 124 select ARM_AMBA 125 select ARM_ARCH_TIMER 126 select ARM_GIC 127 select AUDIT_ARCH_COMPAT_GENERIC 128 select ARM_GIC_V2M if PCI 129 select ARM_GIC_V3 130 select ARM_GIC_V3_ITS if PCI 131 select ARM_PSCI_FW 132 select BUILDTIME_TABLE_SORT 133 select CLONE_BACKWARDS 134 select COMMON_CLK 135 select CPU_PM if (SUSPEND || CPU_IDLE) 136 select CPUMASK_OFFSTACK if NR_CPUS > 256 137 select CRC32 138 select DCACHE_WORD_ACCESS 139 select DYNAMIC_FTRACE if FUNCTION_TRACER 140 select DMA_BOUNCE_UNALIGNED_KMALLOC 141 select DMA_DIRECT_REMAP 142 select EDAC_SUPPORT 143 select FRAME_POINTER 144 select FUNCTION_ALIGNMENT_4B 145 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 146 select GENERIC_ALLOCATOR 147 select GENERIC_ARCH_TOPOLOGY 148 select GENERIC_CLOCKEVENTS_BROADCAST 149 select GENERIC_CPU_AUTOPROBE 150 select GENERIC_CPU_DEVICES 151 select GENERIC_CPU_VULNERABILITIES 152 select GENERIC_EARLY_IOREMAP 153 select GENERIC_IDLE_POLL_SETUP 154 select GENERIC_IOREMAP 155 select GENERIC_IRQ_IPI 156 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 157 select GENERIC_IRQ_PROBE 158 select GENERIC_IRQ_SHOW 159 select GENERIC_IRQ_SHOW_LEVEL 160 select GENERIC_LIB_DEVMEM_IS_ALLOWED 161 select GENERIC_PCI_IOMAP 162 select GENERIC_SCHED_CLOCK 163 select GENERIC_SMP_IDLE_THREAD 164 select GENERIC_TIME_VSYSCALL 165 select GENERIC_GETTIMEOFDAY 166 select GENERIC_VDSO_DATA_STORE 167 select GENERIC_VDSO_TIME_NS 168 select HARDIRQS_SW_RESEND 169 select HAS_IOPORT 170 select HAVE_MOVE_PMD 171 select HAVE_MOVE_PUD 172 select HAVE_PCI 173 select HAVE_ACPI_APEI if (ACPI && EFI) 174 select HAVE_ALIGNED_STRUCT_PAGE 175 select HAVE_ARCH_AUDITSYSCALL 176 select HAVE_ARCH_BITREVERSE 177 select HAVE_ARCH_COMPILER_H 178 select HAVE_ARCH_HUGE_VMALLOC 179 select HAVE_ARCH_HUGE_VMAP 180 select HAVE_ARCH_JUMP_LABEL 181 select HAVE_ARCH_JUMP_LABEL_RELATIVE 182 select HAVE_ARCH_KASAN 183 select HAVE_ARCH_KASAN_VMALLOC 184 select HAVE_ARCH_KASAN_SW_TAGS 185 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 186 # Some instrumentation may be unsound, hence EXPERT 187 select HAVE_ARCH_KCSAN if EXPERT 188 select HAVE_ARCH_KFENCE 189 select HAVE_ARCH_KGDB 190 select HAVE_ARCH_MMAP_RND_BITS 191 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 192 select HAVE_ARCH_PREL32_RELOCATIONS 193 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 194 select HAVE_ARCH_SECCOMP_FILTER 195 select HAVE_ARCH_STACKLEAK 196 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 197 select HAVE_ARCH_TRACEHOOK 198 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 199 select HAVE_ARCH_VMAP_STACK 200 select HAVE_ARM_SMCCC 201 select HAVE_ASM_MODVERSIONS 202 select HAVE_EBPF_JIT 203 select HAVE_C_RECORDMCOUNT 204 select HAVE_CMPXCHG_DOUBLE 205 select HAVE_CMPXCHG_LOCAL 206 select HAVE_CONTEXT_TRACKING_USER 207 select HAVE_DEBUG_KMEMLEAK 208 select HAVE_DMA_CONTIGUOUS 209 select HAVE_DYNAMIC_FTRACE 210 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 211 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 212 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 213 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 214 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 215 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 216 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 217 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 218 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 219 if DYNAMIC_FTRACE_WITH_ARGS 220 select HAVE_SAMPLE_FTRACE_DIRECT 221 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 222 select HAVE_BUILDTIME_MCOUNT_SORT 223 select HAVE_EFFICIENT_UNALIGNED_ACCESS 224 select HAVE_GUP_FAST 225 select HAVE_FTRACE_GRAPH_FUNC 226 select HAVE_FTRACE_MCOUNT_RECORD 227 select HAVE_FUNCTION_TRACER 228 select HAVE_FUNCTION_ERROR_INJECTION 229 select HAVE_FUNCTION_GRAPH_FREGS 230 select HAVE_FUNCTION_GRAPH_TRACER 231 select HAVE_GCC_PLUGINS 232 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 233 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 234 select HAVE_HW_BREAKPOINT if PERF_EVENTS 235 select HAVE_IOREMAP_PROT 236 select HAVE_IRQ_TIME_ACCOUNTING 237 select HAVE_MOD_ARCH_SPECIFIC 238 select HAVE_NMI 239 select HAVE_PERF_EVENTS 240 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 241 select HAVE_PERF_REGS 242 select HAVE_PERF_USER_STACK_DUMP 243 select HAVE_PREEMPT_DYNAMIC_KEY 244 select HAVE_REGS_AND_STACK_ACCESS_API 245 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 246 select HAVE_FUNCTION_ARG_ACCESS_API 247 select MMU_GATHER_RCU_TABLE_FREE 248 select HAVE_RSEQ 249 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 250 select HAVE_STACKPROTECTOR 251 select HAVE_SYSCALL_TRACEPOINTS 252 select HAVE_KPROBES 253 select HAVE_KRETPROBES 254 select HAVE_GENERIC_VDSO 255 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 256 select HOTPLUG_SMT if HOTPLUG_CPU 257 select IRQ_DOMAIN 258 select IRQ_FORCED_THREADING 259 select KASAN_VMALLOC if KASAN 260 select LOCK_MM_AND_FIND_VMA 261 select MODULES_USE_ELF_RELA 262 select NEED_DMA_MAP_STATE 263 select NEED_SG_DMA_LENGTH 264 select OF 265 select OF_EARLY_FLATTREE 266 select PCI_DOMAINS_GENERIC if PCI 267 select PCI_ECAM if (ACPI && PCI) 268 select PCI_SYSCALL if PCI 269 select POWER_RESET 270 select POWER_SUPPLY 271 select SPARSE_IRQ 272 select SWIOTLB 273 select SYSCTL_EXCEPTION_TRACE 274 select THREAD_INFO_IN_TASK 275 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 276 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 277 select TRACE_IRQFLAGS_SUPPORT 278 select TRACE_IRQFLAGS_NMI_SUPPORT 279 select HAVE_SOFTIRQ_ON_OWN_STACK 280 select USER_STACKTRACE_SUPPORT 281 select VDSO_GETRANDOM 282 help 283 ARM 64-bit (AArch64) Linux support. 284 285config RUSTC_SUPPORTS_ARM64 286 def_bool y 287 depends on CPU_LITTLE_ENDIAN 288 # Shadow call stack is only supported on certain rustc versions. 289 # 290 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 291 # required due to use of the -Zfixed-x18 flag. 292 # 293 # Otherwise, rustc version 1.82+ is required due to use of the 294 # -Zsanitizer=shadow-call-stack flag. 295 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 296 297config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 298 def_bool CC_IS_CLANG 299 # https://github.com/ClangBuiltLinux/linux/issues/1507 300 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 301 302config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 303 def_bool CC_IS_GCC 304 depends on $(cc-option,-fpatchable-function-entry=2) 305 306config 64BIT 307 def_bool y 308 309config MMU 310 def_bool y 311 312config ARM64_CONT_PTE_SHIFT 313 int 314 default 5 if PAGE_SIZE_64KB 315 default 7 if PAGE_SIZE_16KB 316 default 4 317 318config ARM64_CONT_PMD_SHIFT 319 int 320 default 5 if PAGE_SIZE_64KB 321 default 5 if PAGE_SIZE_16KB 322 default 4 323 324config ARCH_MMAP_RND_BITS_MIN 325 default 14 if PAGE_SIZE_64KB 326 default 16 if PAGE_SIZE_16KB 327 default 18 328 329# max bits determined by the following formula: 330# VA_BITS - PTDESC_TABLE_SHIFT 331config ARCH_MMAP_RND_BITS_MAX 332 default 19 if ARM64_VA_BITS=36 333 default 24 if ARM64_VA_BITS=39 334 default 27 if ARM64_VA_BITS=42 335 default 30 if ARM64_VA_BITS=47 336 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 337 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 338 default 33 if ARM64_VA_BITS=48 339 default 14 if ARM64_64K_PAGES 340 default 16 if ARM64_16K_PAGES 341 default 18 342 343config ARCH_MMAP_RND_COMPAT_BITS_MIN 344 default 7 if ARM64_64K_PAGES 345 default 9 if ARM64_16K_PAGES 346 default 11 347 348config ARCH_MMAP_RND_COMPAT_BITS_MAX 349 default 16 350 351config NO_IOPORT_MAP 352 def_bool y if !PCI 353 354config STACKTRACE_SUPPORT 355 def_bool y 356 357config ILLEGAL_POINTER_VALUE 358 hex 359 default 0xdead000000000000 360 361config LOCKDEP_SUPPORT 362 def_bool y 363 364config GENERIC_BUG 365 def_bool y 366 depends on BUG 367 368config GENERIC_BUG_RELATIVE_POINTERS 369 def_bool y 370 depends on GENERIC_BUG 371 372config GENERIC_HWEIGHT 373 def_bool y 374 375config GENERIC_CSUM 376 def_bool y 377 378config GENERIC_CALIBRATE_DELAY 379 def_bool y 380 381config SMP 382 def_bool y 383 384config KERNEL_MODE_NEON 385 def_bool y 386 387config FIX_EARLYCON_MEM 388 def_bool y 389 390config PGTABLE_LEVELS 391 int 392 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 393 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 394 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 395 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 396 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 397 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 398 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 399 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 400 401config ARCH_SUPPORTS_UPROBES 402 def_bool y 403 404config ARCH_PROC_KCORE_TEXT 405 def_bool y 406 407config BROKEN_GAS_INST 408 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 409 410config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 411 bool 412 # Clang's __builtin_return_address() strips the PAC since 12.0.0 413 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 414 default y if CC_IS_CLANG 415 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 416 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 417 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 418 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 419 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 420 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 421 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 422 default n 423 424config KASAN_SHADOW_OFFSET 425 hex 426 depends on KASAN_GENERIC || KASAN_SW_TAGS 427 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 428 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 429 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 430 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 431 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 432 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 433 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 434 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 435 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 436 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 437 default 0xffffffffffffffff 438 439config UNWIND_TABLES 440 bool 441 442source "arch/arm64/Kconfig.platforms" 443 444menu "Kernel Features" 445 446menu "ARM errata workarounds via the alternatives framework" 447 448config AMPERE_ERRATUM_AC03_CPU_38 449 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 450 default y 451 help 452 This option adds an alternative code sequence to work around Ampere 453 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 454 455 The affected design reports FEAT_HAFDBS as not implemented in 456 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 457 as required by the architecture. The unadvertised HAFDBS 458 implementation suffers from an additional erratum where hardware 459 A/D updates can occur after a PTE has been marked invalid. 460 461 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 462 which avoids enabling unadvertised hardware Access Flag management 463 at stage-2. 464 465 If unsure, say Y. 466 467config ARM64_WORKAROUND_CLEAN_CACHE 468 bool 469 470config ARM64_ERRATUM_826319 471 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 472 default y 473 select ARM64_WORKAROUND_CLEAN_CACHE 474 help 475 This option adds an alternative code sequence to work around ARM 476 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 477 AXI master interface and an L2 cache. 478 479 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 480 and is unable to accept a certain write via this interface, it will 481 not progress on read data presented on the read data channel and the 482 system can deadlock. 483 484 The workaround promotes data cache clean instructions to 485 data cache clean-and-invalidate. 486 Please note that this does not necessarily enable the workaround, 487 as it depends on the alternative framework, which will only patch 488 the kernel if an affected CPU is detected. 489 490 If unsure, say Y. 491 492config ARM64_ERRATUM_827319 493 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 494 default y 495 select ARM64_WORKAROUND_CLEAN_CACHE 496 help 497 This option adds an alternative code sequence to work around ARM 498 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 499 master interface and an L2 cache. 500 501 Under certain conditions this erratum can cause a clean line eviction 502 to occur at the same time as another transaction to the same address 503 on the AMBA 5 CHI interface, which can cause data corruption if the 504 interconnect reorders the two transactions. 505 506 The workaround promotes data cache clean instructions to 507 data cache clean-and-invalidate. 508 Please note that this does not necessarily enable the workaround, 509 as it depends on the alternative framework, which will only patch 510 the kernel if an affected CPU is detected. 511 512 If unsure, say Y. 513 514config ARM64_ERRATUM_824069 515 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 516 default y 517 select ARM64_WORKAROUND_CLEAN_CACHE 518 help 519 This option adds an alternative code sequence to work around ARM 520 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 521 to a coherent interconnect. 522 523 If a Cortex-A53 processor is executing a store or prefetch for 524 write instruction at the same time as a processor in another 525 cluster is executing a cache maintenance operation to the same 526 address, then this erratum might cause a clean cache line to be 527 incorrectly marked as dirty. 528 529 The workaround promotes data cache clean instructions to 530 data cache clean-and-invalidate. 531 Please note that this option does not necessarily enable the 532 workaround, as it depends on the alternative framework, which will 533 only patch the kernel if an affected CPU is detected. 534 535 If unsure, say Y. 536 537config ARM64_ERRATUM_819472 538 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 539 default y 540 select ARM64_WORKAROUND_CLEAN_CACHE 541 help 542 This option adds an alternative code sequence to work around ARM 543 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 544 present when it is connected to a coherent interconnect. 545 546 If the processor is executing a load and store exclusive sequence at 547 the same time as a processor in another cluster is executing a cache 548 maintenance operation to the same address, then this erratum might 549 cause data corruption. 550 551 The workaround promotes data cache clean instructions to 552 data cache clean-and-invalidate. 553 Please note that this does not necessarily enable the workaround, 554 as it depends on the alternative framework, which will only patch 555 the kernel if an affected CPU is detected. 556 557 If unsure, say Y. 558 559config ARM64_ERRATUM_832075 560 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 561 default y 562 help 563 This option adds an alternative code sequence to work around ARM 564 erratum 832075 on Cortex-A57 parts up to r1p2. 565 566 Affected Cortex-A57 parts might deadlock when exclusive load/store 567 instructions to Write-Back memory are mixed with Device loads. 568 569 The workaround is to promote device loads to use Load-Acquire 570 semantics. 571 Please note that this does not necessarily enable the workaround, 572 as it depends on the alternative framework, which will only patch 573 the kernel if an affected CPU is detected. 574 575 If unsure, say Y. 576 577config ARM64_ERRATUM_834220 578 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 579 depends on KVM 580 help 581 This option adds an alternative code sequence to work around ARM 582 erratum 834220 on Cortex-A57 parts up to r1p2. 583 584 Affected Cortex-A57 parts might report a Stage 2 translation 585 fault as the result of a Stage 1 fault for load crossing a 586 page boundary when there is a permission or device memory 587 alignment fault at Stage 1 and a translation fault at Stage 2. 588 589 The workaround is to verify that the Stage 1 translation 590 doesn't generate a fault before handling the Stage 2 fault. 591 Please note that this does not necessarily enable the workaround, 592 as it depends on the alternative framework, which will only patch 593 the kernel if an affected CPU is detected. 594 595 If unsure, say N. 596 597config ARM64_ERRATUM_1742098 598 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 599 depends on COMPAT 600 default y 601 help 602 This option removes the AES hwcap for aarch32 user-space to 603 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 604 605 Affected parts may corrupt the AES state if an interrupt is 606 taken between a pair of AES instructions. These instructions 607 are only present if the cryptography extensions are present. 608 All software should have a fallback implementation for CPUs 609 that don't implement the cryptography extensions. 610 611 If unsure, say Y. 612 613config ARM64_ERRATUM_845719 614 bool "Cortex-A53: 845719: a load might read incorrect data" 615 depends on COMPAT 616 default y 617 help 618 This option adds an alternative code sequence to work around ARM 619 erratum 845719 on Cortex-A53 parts up to r0p4. 620 621 When running a compat (AArch32) userspace on an affected Cortex-A53 622 part, a load at EL0 from a virtual address that matches the bottom 32 623 bits of the virtual address used by a recent load at (AArch64) EL1 624 might return incorrect data. 625 626 The workaround is to write the contextidr_el1 register on exception 627 return to a 32-bit task. 628 Please note that this does not necessarily enable the workaround, 629 as it depends on the alternative framework, which will only patch 630 the kernel if an affected CPU is detected. 631 632 If unsure, say Y. 633 634config ARM64_ERRATUM_843419 635 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 636 default y 637 help 638 This option links the kernel with '--fix-cortex-a53-843419' and 639 enables PLT support to replace certain ADRP instructions, which can 640 cause subsequent memory accesses to use an incorrect address on 641 Cortex-A53 parts up to r0p4. 642 643 If unsure, say Y. 644 645config ARM64_ERRATUM_1024718 646 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 647 default y 648 help 649 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 650 651 Affected Cortex-A55 cores (all revisions) could cause incorrect 652 update of the hardware dirty bit when the DBM/AP bits are updated 653 without a break-before-make. The workaround is to disable the usage 654 of hardware DBM locally on the affected cores. CPUs not affected by 655 this erratum will continue to use the feature. 656 657 If unsure, say Y. 658 659config ARM64_ERRATUM_1418040 660 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 661 default y 662 depends on COMPAT 663 help 664 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 665 errata 1188873 and 1418040. 666 667 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 668 cause register corruption when accessing the timer registers 669 from AArch32 userspace. 670 671 If unsure, say Y. 672 673config ARM64_WORKAROUND_SPECULATIVE_AT 674 bool 675 676config ARM64_ERRATUM_1165522 677 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 678 default y 679 select ARM64_WORKAROUND_SPECULATIVE_AT 680 help 681 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 682 683 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 684 corrupted TLBs by speculating an AT instruction during a guest 685 context switch. 686 687 If unsure, say Y. 688 689config ARM64_ERRATUM_1319367 690 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 691 default y 692 select ARM64_WORKAROUND_SPECULATIVE_AT 693 help 694 This option adds work arounds for ARM Cortex-A57 erratum 1319537 695 and A72 erratum 1319367 696 697 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 698 speculating an AT instruction during a guest context switch. 699 700 If unsure, say Y. 701 702config ARM64_ERRATUM_1530923 703 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 704 default y 705 select ARM64_WORKAROUND_SPECULATIVE_AT 706 help 707 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 708 709 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 710 corrupted TLBs by speculating an AT instruction during a guest 711 context switch. 712 713 If unsure, say Y. 714 715config ARM64_WORKAROUND_REPEAT_TLBI 716 bool 717 718config ARM64_ERRATUM_2441007 719 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 720 select ARM64_WORKAROUND_REPEAT_TLBI 721 help 722 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 723 724 Under very rare circumstances, affected Cortex-A55 CPUs 725 may not handle a race between a break-before-make sequence on one 726 CPU, and another CPU accessing the same page. This could allow a 727 store to a page that has been unmapped. 728 729 Work around this by adding the affected CPUs to the list that needs 730 TLB sequences to be done twice. 731 732 If unsure, say N. 733 734config ARM64_ERRATUM_1286807 735 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 736 select ARM64_WORKAROUND_REPEAT_TLBI 737 help 738 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 739 740 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 741 address for a cacheable mapping of a location is being 742 accessed by a core while another core is remapping the virtual 743 address to a new physical page using the recommended 744 break-before-make sequence, then under very rare circumstances 745 TLBI+DSB completes before a read using the translation being 746 invalidated has been observed by other observers. The 747 workaround repeats the TLBI+DSB operation. 748 749 If unsure, say N. 750 751config ARM64_ERRATUM_1463225 752 bool "Cortex-A76: Software Step might prevent interrupt recognition" 753 default y 754 help 755 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 756 757 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 758 of a system call instruction (SVC) can prevent recognition of 759 subsequent interrupts when software stepping is disabled in the 760 exception handler of the system call and either kernel debugging 761 is enabled or VHE is in use. 762 763 Work around the erratum by triggering a dummy step exception 764 when handling a system call from a task that is being stepped 765 in a VHE configuration of the kernel. 766 767 If unsure, say Y. 768 769config ARM64_ERRATUM_1542419 770 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 771 help 772 This option adds a workaround for ARM Neoverse-N1 erratum 773 1542419. 774 775 Affected Neoverse-N1 cores could execute a stale instruction when 776 modified by another CPU. The workaround depends on a firmware 777 counterpart. 778 779 Workaround the issue by hiding the DIC feature from EL0. This 780 forces user-space to perform cache maintenance. 781 782 If unsure, say N. 783 784config ARM64_ERRATUM_1508412 785 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 786 default y 787 help 788 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 789 790 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 791 of a store-exclusive or read of PAR_EL1 and a load with device or 792 non-cacheable memory attributes. The workaround depends on a firmware 793 counterpart. 794 795 KVM guests must also have the workaround implemented or they can 796 deadlock the system. 797 798 Work around the issue by inserting DMB SY barriers around PAR_EL1 799 register reads and warning KVM users. The DMB barrier is sufficient 800 to prevent a speculative PAR_EL1 read. 801 802 If unsure, say Y. 803 804config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 805 bool 806 807config ARM64_ERRATUM_2051678 808 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 809 default y 810 help 811 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 812 Affected Cortex-A510 might not respect the ordering rules for 813 hardware update of the page table's dirty bit. The workaround 814 is to not enable the feature on affected CPUs. 815 816 If unsure, say Y. 817 818config ARM64_ERRATUM_2077057 819 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 820 default y 821 help 822 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 823 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 824 expected, but a Pointer Authentication trap is taken instead. The 825 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 826 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 827 828 This can only happen when EL2 is stepping EL1. 829 830 When these conditions occur, the SPSR_EL2 value is unchanged from the 831 previous guest entry, and can be restored from the in-memory copy. 832 833 If unsure, say Y. 834 835config ARM64_ERRATUM_2658417 836 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 837 default y 838 help 839 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 840 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 841 BFMMLA or VMMLA instructions in rare circumstances when a pair of 842 A510 CPUs are using shared neon hardware. As the sharing is not 843 discoverable by the kernel, hide the BF16 HWCAP to indicate that 844 user-space should not be using these instructions. 845 846 If unsure, say Y. 847 848config ARM64_ERRATUM_2119858 849 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 850 default y 851 depends on CORESIGHT_TRBE 852 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 853 help 854 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 855 856 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 857 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 858 the event of a WRAP event. 859 860 Work around the issue by always making sure we move the TRBPTR_EL1 by 861 256 bytes before enabling the buffer and filling the first 256 bytes of 862 the buffer with ETM ignore packets upon disabling. 863 864 If unsure, say Y. 865 866config ARM64_ERRATUM_2139208 867 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 868 default y 869 depends on CORESIGHT_TRBE 870 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 871 help 872 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 873 874 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 875 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 876 the event of a WRAP event. 877 878 Work around the issue by always making sure we move the TRBPTR_EL1 by 879 256 bytes before enabling the buffer and filling the first 256 bytes of 880 the buffer with ETM ignore packets upon disabling. 881 882 If unsure, say Y. 883 884config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 885 bool 886 887config ARM64_ERRATUM_2054223 888 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 889 default y 890 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 891 help 892 Enable workaround for ARM Cortex-A710 erratum 2054223 893 894 Affected cores may fail to flush the trace data on a TSB instruction, when 895 the PE is in trace prohibited state. This will cause losing a few bytes 896 of the trace cached. 897 898 Workaround is to issue two TSB consecutively on affected cores. 899 900 If unsure, say Y. 901 902config ARM64_ERRATUM_2067961 903 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 904 default y 905 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 906 help 907 Enable workaround for ARM Neoverse-N2 erratum 2067961 908 909 Affected cores may fail to flush the trace data on a TSB instruction, when 910 the PE is in trace prohibited state. This will cause losing a few bytes 911 of the trace cached. 912 913 Workaround is to issue two TSB consecutively on affected cores. 914 915 If unsure, say Y. 916 917config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 918 bool 919 920config ARM64_ERRATUM_2253138 921 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 922 depends on CORESIGHT_TRBE 923 default y 924 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 925 help 926 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 927 928 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 929 for TRBE. Under some conditions, the TRBE might generate a write to the next 930 virtually addressed page following the last page of the TRBE address space 931 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 932 933 Work around this in the driver by always making sure that there is a 934 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 935 936 If unsure, say Y. 937 938config ARM64_ERRATUM_2224489 939 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 940 depends on CORESIGHT_TRBE 941 default y 942 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 943 help 944 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 945 946 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 947 for TRBE. Under some conditions, the TRBE might generate a write to the next 948 virtually addressed page following the last page of the TRBE address space 949 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 950 951 Work around this in the driver by always making sure that there is a 952 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 953 954 If unsure, say Y. 955 956config ARM64_ERRATUM_2441009 957 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 958 select ARM64_WORKAROUND_REPEAT_TLBI 959 help 960 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 961 962 Under very rare circumstances, affected Cortex-A510 CPUs 963 may not handle a race between a break-before-make sequence on one 964 CPU, and another CPU accessing the same page. This could allow a 965 store to a page that has been unmapped. 966 967 Work around this by adding the affected CPUs to the list that needs 968 TLB sequences to be done twice. 969 970 If unsure, say N. 971 972config ARM64_ERRATUM_2064142 973 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 974 depends on CORESIGHT_TRBE 975 default y 976 help 977 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 978 979 Affected Cortex-A510 core might fail to write into system registers after the 980 TRBE has been disabled. Under some conditions after the TRBE has been disabled 981 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 982 and TRBTRG_EL1 will be ignored and will not be effected. 983 984 Work around this in the driver by executing TSB CSYNC and DSB after collection 985 is stopped and before performing a system register write to one of the affected 986 registers. 987 988 If unsure, say Y. 989 990config ARM64_ERRATUM_2038923 991 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 992 depends on CORESIGHT_TRBE 993 default y 994 help 995 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 996 997 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 998 prohibited within the CPU. As a result, the trace buffer or trace buffer state 999 might be corrupted. This happens after TRBE buffer has been enabled by setting 1000 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1001 execution changes from a context, in which trace is prohibited to one where it 1002 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1003 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1004 the trace buffer state might be corrupted. 1005 1006 Work around this in the driver by preventing an inconsistent view of whether the 1007 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1008 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1009 two ISB instructions if no ERET is to take place. 1010 1011 If unsure, say Y. 1012 1013config ARM64_ERRATUM_1902691 1014 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1015 depends on CORESIGHT_TRBE 1016 default y 1017 help 1018 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1019 1020 Affected Cortex-A510 core might cause trace data corruption, when being written 1021 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1022 trace data. 1023 1024 Work around this problem in the driver by just preventing TRBE initialization on 1025 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1026 on such implementations. This will cover the kernel for any firmware that doesn't 1027 do this already. 1028 1029 If unsure, say Y. 1030 1031config ARM64_ERRATUM_2457168 1032 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1033 depends on ARM64_AMU_EXTN 1034 default y 1035 help 1036 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1037 1038 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1039 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1040 incorrectly giving a significantly higher output value. 1041 1042 Work around this problem by returning 0 when reading the affected counter in 1043 key locations that results in disabling all users of this counter. This effect 1044 is the same to firmware disabling affected counters. 1045 1046 If unsure, say Y. 1047 1048config ARM64_ERRATUM_2645198 1049 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1050 default y 1051 help 1052 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1053 1054 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1055 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1056 next instruction abort caused by permission fault. 1057 1058 Only user-space does executable to non-executable permission transition via 1059 mprotect() system call. Workaround the problem by doing a break-before-make 1060 TLB invalidation, for all changes to executable user space mappings. 1061 1062 If unsure, say Y. 1063 1064config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1065 bool 1066 1067config ARM64_ERRATUM_2966298 1068 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1069 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1070 default y 1071 help 1072 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1073 1074 On an affected Cortex-A520 core, a speculatively executed unprivileged 1075 load might leak data from a privileged level via a cache side channel. 1076 1077 Work around this problem by executing a TLBI before returning to EL0. 1078 1079 If unsure, say Y. 1080 1081config ARM64_ERRATUM_3117295 1082 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1083 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1084 default y 1085 help 1086 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1087 1088 On an affected Cortex-A510 core, a speculatively executed unprivileged 1089 load might leak data from a privileged level via a cache side channel. 1090 1091 Work around this problem by executing a TLBI before returning to EL0. 1092 1093 If unsure, say Y. 1094 1095config ARM64_ERRATUM_3194386 1096 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1097 default y 1098 help 1099 This option adds the workaround for the following errata: 1100 1101 * ARM Cortex-A76 erratum 3324349 1102 * ARM Cortex-A77 erratum 3324348 1103 * ARM Cortex-A78 erratum 3324344 1104 * ARM Cortex-A78C erratum 3324346 1105 * ARM Cortex-A78C erratum 3324347 1106 * ARM Cortex-A710 erratam 3324338 1107 * ARM Cortex-A715 errartum 3456084 1108 * ARM Cortex-A720 erratum 3456091 1109 * ARM Cortex-A725 erratum 3456106 1110 * ARM Cortex-X1 erratum 3324344 1111 * ARM Cortex-X1C erratum 3324346 1112 * ARM Cortex-X2 erratum 3324338 1113 * ARM Cortex-X3 erratum 3324335 1114 * ARM Cortex-X4 erratum 3194386 1115 * ARM Cortex-X925 erratum 3324334 1116 * ARM Neoverse-N1 erratum 3324349 1117 * ARM Neoverse N2 erratum 3324339 1118 * ARM Neoverse-N3 erratum 3456111 1119 * ARM Neoverse-V1 erratum 3324341 1120 * ARM Neoverse V2 erratum 3324336 1121 * ARM Neoverse-V3 erratum 3312417 1122 1123 On affected cores "MSR SSBS, #0" instructions may not affect 1124 subsequent speculative instructions, which may permit unexepected 1125 speculative store bypassing. 1126 1127 Work around this problem by placing a Speculation Barrier (SB) or 1128 Instruction Synchronization Barrier (ISB) after kernel changes to 1129 SSBS. The presence of the SSBS special-purpose register is hidden 1130 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1131 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1132 1133 If unsure, say Y. 1134 1135config CAVIUM_ERRATUM_22375 1136 bool "Cavium erratum 22375, 24313" 1137 default y 1138 help 1139 Enable workaround for errata 22375 and 24313. 1140 1141 This implements two gicv3-its errata workarounds for ThunderX. Both 1142 with a small impact affecting only ITS table allocation. 1143 1144 erratum 22375: only alloc 8MB table size 1145 erratum 24313: ignore memory access type 1146 1147 The fixes are in ITS initialization and basically ignore memory access 1148 type and table size provided by the TYPER and BASER registers. 1149 1150 If unsure, say Y. 1151 1152config CAVIUM_ERRATUM_23144 1153 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1154 depends on NUMA 1155 default y 1156 help 1157 ITS SYNC command hang for cross node io and collections/cpu mapping. 1158 1159 If unsure, say Y. 1160 1161config CAVIUM_ERRATUM_23154 1162 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1163 default y 1164 help 1165 The ThunderX GICv3 implementation requires a modified version for 1166 reading the IAR status to ensure data synchronization 1167 (access to icc_iar1_el1 is not sync'ed before and after). 1168 1169 It also suffers from erratum 38545 (also present on Marvell's 1170 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1171 spuriously presented to the CPU interface. 1172 1173 If unsure, say Y. 1174 1175config CAVIUM_ERRATUM_27456 1176 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1177 default y 1178 help 1179 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1180 instructions may cause the icache to become corrupted if it 1181 contains data for a non-current ASID. The fix is to 1182 invalidate the icache when changing the mm context. 1183 1184 If unsure, say Y. 1185 1186config CAVIUM_ERRATUM_30115 1187 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1188 default y 1189 help 1190 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1191 1.2, and T83 Pass 1.0, KVM guest execution may disable 1192 interrupts in host. Trapping both GICv3 group-0 and group-1 1193 accesses sidesteps the issue. 1194 1195 If unsure, say Y. 1196 1197config CAVIUM_TX2_ERRATUM_219 1198 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1199 default y 1200 help 1201 On Cavium ThunderX2, a load, store or prefetch instruction between a 1202 TTBR update and the corresponding context synchronizing operation can 1203 cause a spurious Data Abort to be delivered to any hardware thread in 1204 the CPU core. 1205 1206 Work around the issue by avoiding the problematic code sequence and 1207 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1208 trap handler performs the corresponding register access, skips the 1209 instruction and ensures context synchronization by virtue of the 1210 exception return. 1211 1212 If unsure, say Y. 1213 1214config FUJITSU_ERRATUM_010001 1215 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1216 default y 1217 help 1218 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1219 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1220 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1221 This fault occurs under a specific hardware condition when a 1222 load/store instruction performs an address translation using: 1223 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1224 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1225 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1226 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1227 1228 The workaround is to ensure these bits are clear in TCR_ELx. 1229 The workaround only affects the Fujitsu-A64FX. 1230 1231 If unsure, say Y. 1232 1233config HISILICON_ERRATUM_161600802 1234 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1235 default y 1236 help 1237 The HiSilicon Hip07 SoC uses the wrong redistributor base 1238 when issued ITS commands such as VMOVP and VMAPP, and requires 1239 a 128kB offset to be applied to the target address in this commands. 1240 1241 If unsure, say Y. 1242 1243config HISILICON_ERRATUM_162100801 1244 bool "Hip09 162100801 erratum support" 1245 default y 1246 help 1247 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1248 during unmapping operation, which will cause some vSGIs lost. 1249 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1250 after VMOVP. 1251 1252 If unsure, say Y. 1253 1254config QCOM_FALKOR_ERRATUM_1003 1255 bool "Falkor E1003: Incorrect translation due to ASID change" 1256 default y 1257 help 1258 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1259 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1260 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1261 then only for entries in the walk cache, since the leaf translation 1262 is unchanged. Work around the erratum by invalidating the walk cache 1263 entries for the trampoline before entering the kernel proper. 1264 1265config QCOM_FALKOR_ERRATUM_1009 1266 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1267 default y 1268 select ARM64_WORKAROUND_REPEAT_TLBI 1269 help 1270 On Falkor v1, the CPU may prematurely complete a DSB following a 1271 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1272 one more time to fix the issue. 1273 1274 If unsure, say Y. 1275 1276config QCOM_QDF2400_ERRATUM_0065 1277 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1278 default y 1279 help 1280 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1281 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1282 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1283 1284 If unsure, say Y. 1285 1286config QCOM_FALKOR_ERRATUM_E1041 1287 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1288 default y 1289 help 1290 Falkor CPU may speculatively fetch instructions from an improper 1291 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1292 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1293 1294 If unsure, say Y. 1295 1296config NVIDIA_CARMEL_CNP_ERRATUM 1297 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1298 default y 1299 help 1300 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1301 invalidate shared TLB entries installed by a different core, as it would 1302 on standard ARM cores. 1303 1304 If unsure, say Y. 1305 1306config ROCKCHIP_ERRATUM_3568002 1307 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1308 default y 1309 help 1310 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1311 addressing limited to the first 32bit of physical address space. 1312 1313 If unsure, say Y. 1314 1315config ROCKCHIP_ERRATUM_3588001 1316 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1317 default y 1318 help 1319 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1320 This means, that its sharability feature may not be used, even though it 1321 is supported by the IP itself. 1322 1323 If unsure, say Y. 1324 1325config SOCIONEXT_SYNQUACER_PREITS 1326 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1327 default y 1328 help 1329 Socionext Synquacer SoCs implement a separate h/w block to generate 1330 MSI doorbell writes with non-zero values for the device ID. 1331 1332 If unsure, say Y. 1333 1334endmenu # "ARM errata workarounds via the alternatives framework" 1335 1336choice 1337 prompt "Page size" 1338 default ARM64_4K_PAGES 1339 help 1340 Page size (translation granule) configuration. 1341 1342config ARM64_4K_PAGES 1343 bool "4KB" 1344 select HAVE_PAGE_SIZE_4KB 1345 help 1346 This feature enables 4KB pages support. 1347 1348config ARM64_16K_PAGES 1349 bool "16KB" 1350 select HAVE_PAGE_SIZE_16KB 1351 help 1352 The system will use 16KB pages support. AArch32 emulation 1353 requires applications compiled with 16K (or a multiple of 16K) 1354 aligned segments. 1355 1356config ARM64_64K_PAGES 1357 bool "64KB" 1358 select HAVE_PAGE_SIZE_64KB 1359 help 1360 This feature enables 64KB pages support (4KB by default) 1361 allowing only two levels of page tables and faster TLB 1362 look-up. AArch32 emulation requires applications compiled 1363 with 64K aligned segments. 1364 1365endchoice 1366 1367choice 1368 prompt "Virtual address space size" 1369 default ARM64_VA_BITS_52 1370 help 1371 Allows choosing one of multiple possible virtual address 1372 space sizes. The level of translation table is determined by 1373 a combination of page size and virtual address space size. 1374 1375config ARM64_VA_BITS_36 1376 bool "36-bit" if EXPERT 1377 depends on PAGE_SIZE_16KB 1378 1379config ARM64_VA_BITS_39 1380 bool "39-bit" 1381 depends on PAGE_SIZE_4KB 1382 1383config ARM64_VA_BITS_42 1384 bool "42-bit" 1385 depends on PAGE_SIZE_64KB 1386 1387config ARM64_VA_BITS_47 1388 bool "47-bit" 1389 depends on PAGE_SIZE_16KB 1390 1391config ARM64_VA_BITS_48 1392 bool "48-bit" 1393 1394config ARM64_VA_BITS_52 1395 bool "52-bit" 1396 help 1397 Enable 52-bit virtual addressing for userspace when explicitly 1398 requested via a hint to mmap(). The kernel will also use 52-bit 1399 virtual addresses for its own mappings (provided HW support for 1400 this feature is available, otherwise it reverts to 48-bit). 1401 1402 NOTE: Enabling 52-bit virtual addressing in conjunction with 1403 ARMv8.3 Pointer Authentication will result in the PAC being 1404 reduced from 7 bits to 3 bits, which may have a significant 1405 impact on its susceptibility to brute-force attacks. 1406 1407 If unsure, select 48-bit virtual addressing instead. 1408 1409endchoice 1410 1411config ARM64_FORCE_52BIT 1412 bool "Force 52-bit virtual addresses for userspace" 1413 depends on ARM64_VA_BITS_52 && EXPERT 1414 help 1415 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1416 to maintain compatibility with older software by providing 48-bit VAs 1417 unless a hint is supplied to mmap. 1418 1419 This configuration option disables the 48-bit compatibility logic, and 1420 forces all userspace addresses to be 52-bit on HW that supports it. One 1421 should only enable this configuration option for stress testing userspace 1422 memory management code. If unsure say N here. 1423 1424config ARM64_VA_BITS 1425 int 1426 default 36 if ARM64_VA_BITS_36 1427 default 39 if ARM64_VA_BITS_39 1428 default 42 if ARM64_VA_BITS_42 1429 default 47 if ARM64_VA_BITS_47 1430 default 48 if ARM64_VA_BITS_48 1431 default 52 if ARM64_VA_BITS_52 1432 1433choice 1434 prompt "Physical address space size" 1435 default ARM64_PA_BITS_48 1436 help 1437 Choose the maximum physical address range that the kernel will 1438 support. 1439 1440config ARM64_PA_BITS_48 1441 bool "48-bit" 1442 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1443 1444config ARM64_PA_BITS_52 1445 bool "52-bit" 1446 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1447 help 1448 Enable support for a 52-bit physical address space, introduced as 1449 part of the ARMv8.2-LPA extension. 1450 1451 With this enabled, the kernel will also continue to work on CPUs that 1452 do not support ARMv8.2-LPA, but with some added memory overhead (and 1453 minor performance overhead). 1454 1455endchoice 1456 1457config ARM64_PA_BITS 1458 int 1459 default 48 if ARM64_PA_BITS_48 1460 default 52 if ARM64_PA_BITS_52 1461 1462config ARM64_LPA2 1463 def_bool y 1464 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1465 1466choice 1467 prompt "Endianness" 1468 default CPU_LITTLE_ENDIAN 1469 help 1470 Select the endianness of data accesses performed by the CPU. Userspace 1471 applications will need to be compiled and linked for the endianness 1472 that is selected here. 1473 1474config CPU_BIG_ENDIAN 1475 bool "Build big-endian kernel" 1476 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1477 depends on AS_IS_GNU || AS_VERSION >= 150000 1478 help 1479 Say Y if you plan on running a kernel with a big-endian userspace. 1480 1481config CPU_LITTLE_ENDIAN 1482 bool "Build little-endian kernel" 1483 help 1484 Say Y if you plan on running a kernel with a little-endian userspace. 1485 This is usually the case for distributions targeting arm64. 1486 1487endchoice 1488 1489config SCHED_MC 1490 bool "Multi-core scheduler support" 1491 help 1492 Multi-core scheduler support improves the CPU scheduler's decision 1493 making when dealing with multi-core CPU chips at a cost of slightly 1494 increased overhead in some places. If unsure say N here. 1495 1496config SCHED_CLUSTER 1497 bool "Cluster scheduler support" 1498 help 1499 Cluster scheduler support improves the CPU scheduler's decision 1500 making when dealing with machines that have clusters of CPUs. 1501 Cluster usually means a couple of CPUs which are placed closely 1502 by sharing mid-level caches, last-level cache tags or internal 1503 busses. 1504 1505config SCHED_SMT 1506 bool "SMT scheduler support" 1507 help 1508 Improves the CPU scheduler's decision making when dealing with 1509 MultiThreading at a cost of slightly increased overhead in some 1510 places. If unsure say N here. 1511 1512config NR_CPUS 1513 int "Maximum number of CPUs (2-4096)" 1514 range 2 4096 1515 default "512" 1516 1517config HOTPLUG_CPU 1518 bool "Support for hot-pluggable CPUs" 1519 select GENERIC_IRQ_MIGRATION 1520 help 1521 Say Y here to experiment with turning CPUs off and on. CPUs 1522 can be controlled through /sys/devices/system/cpu. 1523 1524# Common NUMA Features 1525config NUMA 1526 bool "NUMA Memory Allocation and Scheduler Support" 1527 select GENERIC_ARCH_NUMA 1528 select OF_NUMA 1529 select HAVE_SETUP_PER_CPU_AREA 1530 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1531 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1532 select USE_PERCPU_NUMA_NODE_ID 1533 help 1534 Enable NUMA (Non-Uniform Memory Access) support. 1535 1536 The kernel will try to allocate memory used by a CPU on the 1537 local memory of the CPU and add some more 1538 NUMA awareness to the kernel. 1539 1540config NODES_SHIFT 1541 int "Maximum NUMA Nodes (as a power of 2)" 1542 range 1 10 1543 default "4" 1544 depends on NUMA 1545 help 1546 Specify the maximum number of NUMA Nodes available on the target 1547 system. Increases memory reserved to accommodate various tables. 1548 1549source "kernel/Kconfig.hz" 1550 1551config ARCH_SPARSEMEM_ENABLE 1552 def_bool y 1553 select SPARSEMEM_VMEMMAP_ENABLE 1554 select SPARSEMEM_VMEMMAP 1555 1556config HW_PERF_EVENTS 1557 def_bool y 1558 depends on ARM_PMU 1559 1560# Supported by clang >= 7.0 or GCC >= 12.0.0 1561config CC_HAVE_SHADOW_CALL_STACK 1562 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1563 1564config PARAVIRT 1565 bool "Enable paravirtualization code" 1566 help 1567 This changes the kernel so it can modify itself when it is run 1568 under a hypervisor, potentially improving performance significantly 1569 over full virtualization. 1570 1571config PARAVIRT_TIME_ACCOUNTING 1572 bool "Paravirtual steal time accounting" 1573 select PARAVIRT 1574 help 1575 Select this option to enable fine granularity task steal time 1576 accounting. Time spent executing other tasks in parallel with 1577 the current vCPU is discounted from the vCPU power. To account for 1578 that, there can be a small performance impact. 1579 1580 If in doubt, say N here. 1581 1582config ARCH_SUPPORTS_KEXEC 1583 def_bool PM_SLEEP_SMP 1584 1585config ARCH_SUPPORTS_KEXEC_FILE 1586 def_bool y 1587 1588config ARCH_SELECTS_KEXEC_FILE 1589 def_bool y 1590 depends on KEXEC_FILE 1591 select HAVE_IMA_KEXEC if IMA 1592 1593config ARCH_SUPPORTS_KEXEC_SIG 1594 def_bool y 1595 1596config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1597 def_bool y 1598 1599config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1600 def_bool y 1601 1602config ARCH_SUPPORTS_CRASH_DUMP 1603 def_bool y 1604 1605config ARCH_DEFAULT_CRASH_DUMP 1606 def_bool y 1607 1608config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1609 def_bool CRASH_RESERVE 1610 1611config TRANS_TABLE 1612 def_bool y 1613 depends on HIBERNATION || KEXEC_CORE 1614 1615config XEN_DOM0 1616 def_bool y 1617 depends on XEN 1618 1619config XEN 1620 bool "Xen guest support on ARM64" 1621 depends on ARM64 && OF 1622 select SWIOTLB_XEN 1623 select PARAVIRT 1624 help 1625 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1626 1627# include/linux/mmzone.h requires the following to be true: 1628# 1629# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1630# 1631# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1632# 1633# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1634# ----+-------------------+--------------+----------------------+-------------------------+ 1635# 4K | 27 | 12 | 15 | 10 | 1636# 16K | 27 | 14 | 13 | 11 | 1637# 64K | 29 | 16 | 13 | 13 | 1638config ARCH_FORCE_MAX_ORDER 1639 int 1640 default "13" if ARM64_64K_PAGES 1641 default "11" if ARM64_16K_PAGES 1642 default "10" 1643 help 1644 The kernel page allocator limits the size of maximal physically 1645 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1646 defines the maximal power of two of number of pages that can be 1647 allocated as a single contiguous block. This option allows 1648 overriding the default setting when ability to allocate very 1649 large blocks of physically contiguous memory is required. 1650 1651 The maximal size of allocation cannot exceed the size of the 1652 section, so the value of MAX_PAGE_ORDER should satisfy 1653 1654 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1655 1656 Don't change if unsure. 1657 1658config UNMAP_KERNEL_AT_EL0 1659 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1660 default y 1661 help 1662 Speculation attacks against some high-performance processors can 1663 be used to bypass MMU permission checks and leak kernel data to 1664 userspace. This can be defended against by unmapping the kernel 1665 when running in userspace, mapping it back in on exception entry 1666 via a trampoline page in the vector table. 1667 1668 If unsure, say Y. 1669 1670config MITIGATE_SPECTRE_BRANCH_HISTORY 1671 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1672 default y 1673 help 1674 Speculation attacks against some high-performance processors can 1675 make use of branch history to influence future speculation. 1676 When taking an exception from user-space, a sequence of branches 1677 or a firmware call overwrites the branch history. 1678 1679config RODATA_FULL_DEFAULT_ENABLED 1680 bool "Apply r/o permissions of VM areas also to their linear aliases" 1681 default y 1682 help 1683 Apply read-only attributes of VM areas to the linear alias of 1684 the backing pages as well. This prevents code or read-only data 1685 from being modified (inadvertently or intentionally) via another 1686 mapping of the same memory page. This additional enhancement can 1687 be turned off at runtime by passing rodata=[off|on] (and turned on 1688 with rodata=full if this option is set to 'n') 1689 1690 This requires the linear region to be mapped down to pages, 1691 which may adversely affect performance in some cases. 1692 1693config ARM64_SW_TTBR0_PAN 1694 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1695 depends on !KCSAN 1696 select ARM64_PAN 1697 help 1698 Enabling this option prevents the kernel from accessing 1699 user-space memory directly by pointing TTBR0_EL1 to a reserved 1700 zeroed area and reserved ASID. The user access routines 1701 restore the valid TTBR0_EL1 temporarily. 1702 1703config ARM64_TAGGED_ADDR_ABI 1704 bool "Enable the tagged user addresses syscall ABI" 1705 default y 1706 help 1707 When this option is enabled, user applications can opt in to a 1708 relaxed ABI via prctl() allowing tagged addresses to be passed 1709 to system calls as pointer arguments. For details, see 1710 Documentation/arch/arm64/tagged-address-abi.rst. 1711 1712menuconfig COMPAT 1713 bool "Kernel support for 32-bit EL0" 1714 depends on ARM64_4K_PAGES || EXPERT 1715 select HAVE_UID16 1716 select OLD_SIGSUSPEND3 1717 select COMPAT_OLD_SIGACTION 1718 help 1719 This option enables support for a 32-bit EL0 running under a 64-bit 1720 kernel at EL1. AArch32-specific components such as system calls, 1721 the user helper functions, VFP support and the ptrace interface are 1722 handled appropriately by the kernel. 1723 1724 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1725 that you will only be able to execute AArch32 binaries that were compiled 1726 with page size aligned segments. 1727 1728 If you want to execute 32-bit userspace applications, say Y. 1729 1730if COMPAT 1731 1732config KUSER_HELPERS 1733 bool "Enable kuser helpers page for 32-bit applications" 1734 default y 1735 help 1736 Warning: disabling this option may break 32-bit user programs. 1737 1738 Provide kuser helpers to compat tasks. The kernel provides 1739 helper code to userspace in read only form at a fixed location 1740 to allow userspace to be independent of the CPU type fitted to 1741 the system. This permits binaries to be run on ARMv4 through 1742 to ARMv8 without modification. 1743 1744 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1745 1746 However, the fixed address nature of these helpers can be used 1747 by ROP (return orientated programming) authors when creating 1748 exploits. 1749 1750 If all of the binaries and libraries which run on your platform 1751 are built specifically for your platform, and make no use of 1752 these helpers, then you can turn this option off to hinder 1753 such exploits. However, in that case, if a binary or library 1754 relying on those helpers is run, it will not function correctly. 1755 1756 Say N here only if you are absolutely certain that you do not 1757 need these helpers; otherwise, the safe option is to say Y. 1758 1759config COMPAT_VDSO 1760 bool "Enable vDSO for 32-bit applications" 1761 depends on !CPU_BIG_ENDIAN 1762 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1763 select GENERIC_COMPAT_VDSO 1764 default y 1765 help 1766 Place in the process address space of 32-bit applications an 1767 ELF shared object providing fast implementations of gettimeofday 1768 and clock_gettime. 1769 1770 You must have a 32-bit build of glibc 2.22 or later for programs 1771 to seamlessly take advantage of this. 1772 1773config THUMB2_COMPAT_VDSO 1774 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1775 depends on COMPAT_VDSO 1776 default y 1777 help 1778 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1779 otherwise with '-marm'. 1780 1781config COMPAT_ALIGNMENT_FIXUPS 1782 bool "Fix up misaligned multi-word loads and stores in user space" 1783 1784menuconfig ARMV8_DEPRECATED 1785 bool "Emulate deprecated/obsolete ARMv8 instructions" 1786 depends on SYSCTL 1787 help 1788 Legacy software support may require certain instructions 1789 that have been deprecated or obsoleted in the architecture. 1790 1791 Enable this config to enable selective emulation of these 1792 features. 1793 1794 If unsure, say Y 1795 1796if ARMV8_DEPRECATED 1797 1798config SWP_EMULATION 1799 bool "Emulate SWP/SWPB instructions" 1800 help 1801 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1802 they are always undefined. Say Y here to enable software 1803 emulation of these instructions for userspace using LDXR/STXR. 1804 This feature can be controlled at runtime with the abi.swp 1805 sysctl which is disabled by default. 1806 1807 In some older versions of glibc [<=2.8] SWP is used during futex 1808 trylock() operations with the assumption that the code will not 1809 be preempted. This invalid assumption may be more likely to fail 1810 with SWP emulation enabled, leading to deadlock of the user 1811 application. 1812 1813 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1814 on an external transaction monitoring block called a global 1815 monitor to maintain update atomicity. If your system does not 1816 implement a global monitor, this option can cause programs that 1817 perform SWP operations to uncached memory to deadlock. 1818 1819 If unsure, say Y 1820 1821config CP15_BARRIER_EMULATION 1822 bool "Emulate CP15 Barrier instructions" 1823 help 1824 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1825 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1826 strongly recommended to use the ISB, DSB, and DMB 1827 instructions instead. 1828 1829 Say Y here to enable software emulation of these 1830 instructions for AArch32 userspace code. When this option is 1831 enabled, CP15 barrier usage is traced which can help 1832 identify software that needs updating. This feature can be 1833 controlled at runtime with the abi.cp15_barrier sysctl. 1834 1835 If unsure, say Y 1836 1837config SETEND_EMULATION 1838 bool "Emulate SETEND instruction" 1839 help 1840 The SETEND instruction alters the data-endianness of the 1841 AArch32 EL0, and is deprecated in ARMv8. 1842 1843 Say Y here to enable software emulation of the instruction 1844 for AArch32 userspace code. This feature can be controlled 1845 at runtime with the abi.setend sysctl. 1846 1847 Note: All the cpus on the system must have mixed endian support at EL0 1848 for this feature to be enabled. If a new CPU - which doesn't support mixed 1849 endian - is hotplugged in after this feature has been enabled, there could 1850 be unexpected results in the applications. 1851 1852 If unsure, say Y 1853endif # ARMV8_DEPRECATED 1854 1855endif # COMPAT 1856 1857menu "ARMv8.1 architectural features" 1858 1859config ARM64_HW_AFDBM 1860 bool "Support for hardware updates of the Access and Dirty page flags" 1861 default y 1862 help 1863 The ARMv8.1 architecture extensions introduce support for 1864 hardware updates of the access and dirty information in page 1865 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1866 capable processors, accesses to pages with PTE_AF cleared will 1867 set this bit instead of raising an access flag fault. 1868 Similarly, writes to read-only pages with the DBM bit set will 1869 clear the read-only bit (AP[2]) instead of raising a 1870 permission fault. 1871 1872 Kernels built with this configuration option enabled continue 1873 to work on pre-ARMv8.1 hardware and the performance impact is 1874 minimal. If unsure, say Y. 1875 1876config ARM64_PAN 1877 bool "Enable support for Privileged Access Never (PAN)" 1878 default y 1879 help 1880 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1881 prevents the kernel or hypervisor from accessing user-space (EL0) 1882 memory directly. 1883 1884 Choosing this option will cause any unprotected (not using 1885 copy_to_user et al) memory access to fail with a permission fault. 1886 1887 The feature is detected at runtime, and will remain as a 'nop' 1888 instruction if the cpu does not implement the feature. 1889 1890config ARM64_LSE_ATOMICS 1891 bool 1892 default ARM64_USE_LSE_ATOMICS 1893 1894config ARM64_USE_LSE_ATOMICS 1895 bool "Atomic instructions" 1896 default y 1897 help 1898 As part of the Large System Extensions, ARMv8.1 introduces new 1899 atomic instructions that are designed specifically to scale in 1900 very large systems. 1901 1902 Say Y here to make use of these instructions for the in-kernel 1903 atomic routines. This incurs a small overhead on CPUs that do 1904 not support these instructions. 1905 1906endmenu # "ARMv8.1 architectural features" 1907 1908menu "ARMv8.2 architectural features" 1909 1910config ARM64_PMEM 1911 bool "Enable support for persistent memory" 1912 select ARCH_HAS_PMEM_API 1913 select ARCH_HAS_UACCESS_FLUSHCACHE 1914 help 1915 Say Y to enable support for the persistent memory API based on the 1916 ARMv8.2 DCPoP feature. 1917 1918 The feature is detected at runtime, and the kernel will use DC CVAC 1919 operations if DC CVAP is not supported (following the behaviour of 1920 DC CVAP itself if the system does not define a point of persistence). 1921 1922config ARM64_RAS_EXTN 1923 bool "Enable support for RAS CPU Extensions" 1924 default y 1925 help 1926 CPUs that support the Reliability, Availability and Serviceability 1927 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1928 errors, classify them and report them to software. 1929 1930 On CPUs with these extensions system software can use additional 1931 barriers to determine if faults are pending and read the 1932 classification from a new set of registers. 1933 1934 Selecting this feature will allow the kernel to use these barriers 1935 and access the new registers if the system supports the extension. 1936 Platform RAS features may additionally depend on firmware support. 1937 1938config ARM64_CNP 1939 bool "Enable support for Common Not Private (CNP) translations" 1940 default y 1941 help 1942 Common Not Private (CNP) allows translation table entries to 1943 be shared between different PEs in the same inner shareable 1944 domain, so the hardware can use this fact to optimise the 1945 caching of such entries in the TLB. 1946 1947 Selecting this option allows the CNP feature to be detected 1948 at runtime, and does not affect PEs that do not implement 1949 this feature. 1950 1951endmenu # "ARMv8.2 architectural features" 1952 1953menu "ARMv8.3 architectural features" 1954 1955config ARM64_PTR_AUTH 1956 bool "Enable support for pointer authentication" 1957 default y 1958 help 1959 Pointer authentication (part of the ARMv8.3 Extensions) provides 1960 instructions for signing and authenticating pointers against secret 1961 keys, which can be used to mitigate Return Oriented Programming (ROP) 1962 and other attacks. 1963 1964 This option enables these instructions at EL0 (i.e. for userspace). 1965 Choosing this option will cause the kernel to initialise secret keys 1966 for each process at exec() time, with these keys being 1967 context-switched along with the process. 1968 1969 The feature is detected at runtime. If the feature is not present in 1970 hardware it will not be advertised to userspace/KVM guest nor will it 1971 be enabled. 1972 1973 If the feature is present on the boot CPU but not on a late CPU, then 1974 the late CPU will be parked. Also, if the boot CPU does not have 1975 address auth and the late CPU has then the late CPU will still boot 1976 but with the feature disabled. On such a system, this option should 1977 not be selected. 1978 1979config ARM64_PTR_AUTH_KERNEL 1980 bool "Use pointer authentication for kernel" 1981 default y 1982 depends on ARM64_PTR_AUTH 1983 # Modern compilers insert a .note.gnu.property section note for PAC 1984 # which is only understood by binutils starting with version 2.33.1. 1985 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1986 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1987 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1988 help 1989 If the compiler supports the -mbranch-protection or 1990 -msign-return-address flag (e.g. GCC 7 or later), then this option 1991 will cause the kernel itself to be compiled with return address 1992 protection. In this case, and if the target hardware is known to 1993 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1994 disabled with minimal loss of protection. 1995 1996 This feature works with FUNCTION_GRAPH_TRACER option only if 1997 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1998 1999config CC_HAS_BRANCH_PROT_PAC_RET 2000 # GCC 9 or later, clang 8 or later 2001 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2002 2003config AS_HAS_CFI_NEGATE_RA_STATE 2004 # binutils 2.34+ 2005 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2006 2007endmenu # "ARMv8.3 architectural features" 2008 2009menu "ARMv8.4 architectural features" 2010 2011config ARM64_AMU_EXTN 2012 bool "Enable support for the Activity Monitors Unit CPU extension" 2013 default y 2014 help 2015 The activity monitors extension is an optional extension introduced 2016 by the ARMv8.4 CPU architecture. This enables support for version 1 2017 of the activity monitors architecture, AMUv1. 2018 2019 To enable the use of this extension on CPUs that implement it, say Y. 2020 2021 Note that for architectural reasons, firmware _must_ implement AMU 2022 support when running on CPUs that present the activity monitors 2023 extension. The required support is present in: 2024 * Version 1.5 and later of the ARM Trusted Firmware 2025 2026 For kernels that have this configuration enabled but boot with broken 2027 firmware, you may need to say N here until the firmware is fixed. 2028 Otherwise you may experience firmware panics or lockups when 2029 accessing the counter registers. Even if you are not observing these 2030 symptoms, the values returned by the register reads might not 2031 correctly reflect reality. Most commonly, the value read will be 0, 2032 indicating that the counter is not enabled. 2033 2034config ARM64_TLB_RANGE 2035 bool "Enable support for tlbi range feature" 2036 default y 2037 help 2038 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2039 range of input addresses. 2040 2041endmenu # "ARMv8.4 architectural features" 2042 2043menu "ARMv8.5 architectural features" 2044 2045config AS_HAS_ARMV8_5 2046 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2047 2048config ARM64_BTI 2049 bool "Branch Target Identification support" 2050 default y 2051 help 2052 Branch Target Identification (part of the ARMv8.5 Extensions) 2053 provides a mechanism to limit the set of locations to which computed 2054 branch instructions such as BR or BLR can jump. 2055 2056 To make use of BTI on CPUs that support it, say Y. 2057 2058 BTI is intended to provide complementary protection to other control 2059 flow integrity protection mechanisms, such as the Pointer 2060 authentication mechanism provided as part of the ARMv8.3 Extensions. 2061 For this reason, it does not make sense to enable this option without 2062 also enabling support for pointer authentication. Thus, when 2063 enabling this option you should also select ARM64_PTR_AUTH=y. 2064 2065 Userspace binaries must also be specifically compiled to make use of 2066 this mechanism. If you say N here or the hardware does not support 2067 BTI, such binaries can still run, but you get no additional 2068 enforcement of branch destinations. 2069 2070config ARM64_BTI_KERNEL 2071 bool "Use Branch Target Identification for kernel" 2072 default y 2073 depends on ARM64_BTI 2074 depends on ARM64_PTR_AUTH_KERNEL 2075 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2076 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2077 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2078 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2079 depends on !CC_IS_GCC 2080 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2081 help 2082 Build the kernel with Branch Target Identification annotations 2083 and enable enforcement of this for kernel code. When this option 2084 is enabled and the system supports BTI all kernel code including 2085 modular code must have BTI enabled. 2086 2087config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2088 # GCC 9 or later, clang 8 or later 2089 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2090 2091config ARM64_E0PD 2092 bool "Enable support for E0PD" 2093 default y 2094 help 2095 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2096 that EL0 accesses made via TTBR1 always fault in constant time, 2097 providing similar benefits to KASLR as those provided by KPTI, but 2098 with lower overhead and without disrupting legitimate access to 2099 kernel memory such as SPE. 2100 2101 This option enables E0PD for TTBR1 where available. 2102 2103config ARM64_AS_HAS_MTE 2104 # Initial support for MTE went in binutils 2.32.0, checked with 2105 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2106 # as a late addition to the final architecture spec (LDGM/STGM) 2107 # is only supported in the newer 2.32.x and 2.33 binutils 2108 # versions, hence the extra "stgm" instruction check below. 2109 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2110 2111config ARM64_MTE 2112 bool "Memory Tagging Extension support" 2113 default y 2114 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2115 depends on AS_HAS_ARMV8_5 2116 # Required for tag checking in the uaccess routines 2117 select ARM64_PAN 2118 select ARCH_HAS_SUBPAGE_FAULTS 2119 select ARCH_USES_HIGH_VMA_FLAGS 2120 select ARCH_USES_PG_ARCH_2 2121 select ARCH_USES_PG_ARCH_3 2122 help 2123 Memory Tagging (part of the ARMv8.5 Extensions) provides 2124 architectural support for run-time, always-on detection of 2125 various classes of memory error to aid with software debugging 2126 to eliminate vulnerabilities arising from memory-unsafe 2127 languages. 2128 2129 This option enables the support for the Memory Tagging 2130 Extension at EL0 (i.e. for userspace). 2131 2132 Selecting this option allows the feature to be detected at 2133 runtime. Any secondary CPU not implementing this feature will 2134 not be allowed a late bring-up. 2135 2136 Userspace binaries that want to use this feature must 2137 explicitly opt in. The mechanism for the userspace is 2138 described in: 2139 2140 Documentation/arch/arm64/memory-tagging-extension.rst. 2141 2142endmenu # "ARMv8.5 architectural features" 2143 2144menu "ARMv8.7 architectural features" 2145 2146config ARM64_EPAN 2147 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2148 default y 2149 depends on ARM64_PAN 2150 help 2151 Enhanced Privileged Access Never (EPAN) allows Privileged 2152 Access Never to be used with Execute-only mappings. 2153 2154 The feature is detected at runtime, and will remain disabled 2155 if the cpu does not implement the feature. 2156endmenu # "ARMv8.7 architectural features" 2157 2158config AS_HAS_MOPS 2159 def_bool $(as-instr,.arch_extension mops) 2160 2161menu "ARMv8.9 architectural features" 2162 2163config ARM64_POE 2164 prompt "Permission Overlay Extension" 2165 def_bool y 2166 select ARCH_USES_HIGH_VMA_FLAGS 2167 select ARCH_HAS_PKEYS 2168 help 2169 The Permission Overlay Extension is used to implement Memory 2170 Protection Keys. Memory Protection Keys provides a mechanism for 2171 enforcing page-based protections, but without requiring modification 2172 of the page tables when an application changes protection domains. 2173 2174 For details, see Documentation/core-api/protection-keys.rst 2175 2176 If unsure, say y. 2177 2178config ARCH_PKEY_BITS 2179 int 2180 default 3 2181 2182config ARM64_HAFT 2183 bool "Support for Hardware managed Access Flag for Table Descriptors" 2184 depends on ARM64_HW_AFDBM 2185 default y 2186 help 2187 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2188 Flag for Table descriptors. When enabled an architectural executed 2189 memory access will update the Access Flag in each Table descriptor 2190 which is accessed during the translation table walk and for which 2191 the Access Flag is 0. The Access Flag of the Table descriptor use 2192 the same bit of PTE_AF. 2193 2194 The feature will only be enabled if all the CPUs in the system 2195 support this feature. If unsure, say Y. 2196 2197endmenu # "ARMv8.9 architectural features" 2198 2199menu "v9.4 architectural features" 2200 2201config ARM64_GCS 2202 bool "Enable support for Guarded Control Stack (GCS)" 2203 default y 2204 select ARCH_HAS_USER_SHADOW_STACK 2205 select ARCH_USES_HIGH_VMA_FLAGS 2206 depends on !UPROBES 2207 help 2208 Guarded Control Stack (GCS) provides support for a separate 2209 stack with restricted access which contains only return 2210 addresses. This can be used to harden against some attacks 2211 by comparing return address used by the program with what is 2212 stored in the GCS, and may also be used to efficiently obtain 2213 the call stack for applications such as profiling. 2214 2215 The feature is detected at runtime, and will remain disabled 2216 if the system does not implement the feature. 2217 2218endmenu # "v9.4 architectural features" 2219 2220config ARM64_SVE 2221 bool "ARM Scalable Vector Extension support" 2222 default y 2223 help 2224 The Scalable Vector Extension (SVE) is an extension to the AArch64 2225 execution state which complements and extends the SIMD functionality 2226 of the base architecture to support much larger vectors and to enable 2227 additional vectorisation opportunities. 2228 2229 To enable use of this extension on CPUs that implement it, say Y. 2230 2231 On CPUs that support the SVE2 extensions, this option will enable 2232 those too. 2233 2234 Note that for architectural reasons, firmware _must_ implement SVE 2235 support when running on SVE capable hardware. The required support 2236 is present in: 2237 2238 * version 1.5 and later of the ARM Trusted Firmware 2239 * the AArch64 boot wrapper since commit 5e1261e08abf 2240 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2241 2242 For other firmware implementations, consult the firmware documentation 2243 or vendor. 2244 2245 If you need the kernel to boot on SVE-capable hardware with broken 2246 firmware, you may need to say N here until you get your firmware 2247 fixed. Otherwise, you may experience firmware panics or lockups when 2248 booting the kernel. If unsure and you are not observing these 2249 symptoms, you should assume that it is safe to say Y. 2250 2251config ARM64_SME 2252 bool "ARM Scalable Matrix Extension support" 2253 default y 2254 depends on ARM64_SVE 2255 depends on BROKEN 2256 help 2257 The Scalable Matrix Extension (SME) is an extension to the AArch64 2258 execution state which utilises a substantial subset of the SVE 2259 instruction set, together with the addition of new architectural 2260 register state capable of holding two dimensional matrix tiles to 2261 enable various matrix operations. 2262 2263config ARM64_PSEUDO_NMI 2264 bool "Support for NMI-like interrupts" 2265 select ARM_GIC_V3 2266 help 2267 Adds support for mimicking Non-Maskable Interrupts through the use of 2268 GIC interrupt priority. This support requires version 3 or later of 2269 ARM GIC. 2270 2271 This high priority configuration for interrupts needs to be 2272 explicitly enabled by setting the kernel parameter 2273 "irqchip.gicv3_pseudo_nmi" to 1. 2274 2275 If unsure, say N 2276 2277if ARM64_PSEUDO_NMI 2278config ARM64_DEBUG_PRIORITY_MASKING 2279 bool "Debug interrupt priority masking" 2280 help 2281 This adds runtime checks to functions enabling/disabling 2282 interrupts when using priority masking. The additional checks verify 2283 the validity of ICC_PMR_EL1 when calling concerned functions. 2284 2285 If unsure, say N 2286endif # ARM64_PSEUDO_NMI 2287 2288config RELOCATABLE 2289 bool "Build a relocatable kernel image" if EXPERT 2290 select ARCH_HAS_RELR 2291 default y 2292 help 2293 This builds the kernel as a Position Independent Executable (PIE), 2294 which retains all relocation metadata required to relocate the 2295 kernel binary at runtime to a different virtual address than the 2296 address it was linked at. 2297 Since AArch64 uses the RELA relocation format, this requires a 2298 relocation pass at runtime even if the kernel is loaded at the 2299 same address it was linked at. 2300 2301config RANDOMIZE_BASE 2302 bool "Randomize the address of the kernel image" 2303 select RELOCATABLE 2304 help 2305 Randomizes the virtual address at which the kernel image is 2306 loaded, as a security feature that deters exploit attempts 2307 relying on knowledge of the location of kernel internals. 2308 2309 It is the bootloader's job to provide entropy, by passing a 2310 random u64 value in /chosen/kaslr-seed at kernel entry. 2311 2312 When booting via the UEFI stub, it will invoke the firmware's 2313 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2314 to the kernel proper. In addition, it will randomise the physical 2315 location of the kernel Image as well. 2316 2317 If unsure, say N. 2318 2319config RANDOMIZE_MODULE_REGION_FULL 2320 bool "Randomize the module region over a 2 GB range" 2321 depends on RANDOMIZE_BASE 2322 default y 2323 help 2324 Randomizes the location of the module region inside a 2 GB window 2325 covering the core kernel. This way, it is less likely for modules 2326 to leak information about the location of core kernel data structures 2327 but it does imply that function calls between modules and the core 2328 kernel will need to be resolved via veneers in the module PLT. 2329 2330 When this option is not set, the module region will be randomized over 2331 a limited range that contains the [_stext, _etext] interval of the 2332 core kernel, so branch relocations are almost always in range unless 2333 the region is exhausted. In this particular case of region 2334 exhaustion, modules might be able to fall back to a larger 2GB area. 2335 2336config CC_HAVE_STACKPROTECTOR_SYSREG 2337 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2338 2339config STACKPROTECTOR_PER_TASK 2340 def_bool y 2341 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2342 2343config UNWIND_PATCH_PAC_INTO_SCS 2344 bool "Enable shadow call stack dynamically using code patching" 2345 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2346 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2347 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2348 depends on SHADOW_CALL_STACK 2349 select UNWIND_TABLES 2350 select DYNAMIC_SCS 2351 2352config ARM64_CONTPTE 2353 bool "Contiguous PTE mappings for user memory" if EXPERT 2354 depends on TRANSPARENT_HUGEPAGE 2355 default y 2356 help 2357 When enabled, user mappings are configured using the PTE contiguous 2358 bit, for any mappings that meet the size and alignment requirements. 2359 This reduces TLB pressure and improves performance. 2360 2361endmenu # "Kernel Features" 2362 2363menu "Boot options" 2364 2365config ARM64_ACPI_PARKING_PROTOCOL 2366 bool "Enable support for the ARM64 ACPI parking protocol" 2367 depends on ACPI 2368 help 2369 Enable support for the ARM64 ACPI parking protocol. If disabled 2370 the kernel will not allow booting through the ARM64 ACPI parking 2371 protocol even if the corresponding data is present in the ACPI 2372 MADT table. 2373 2374config CMDLINE 2375 string "Default kernel command string" 2376 default "" 2377 help 2378 Provide a set of default command-line options at build time by 2379 entering them here. As a minimum, you should specify the the 2380 root device (e.g. root=/dev/nfs). 2381 2382choice 2383 prompt "Kernel command line type" 2384 depends on CMDLINE != "" 2385 default CMDLINE_FROM_BOOTLOADER 2386 help 2387 Choose how the kernel will handle the provided default kernel 2388 command line string. 2389 2390config CMDLINE_FROM_BOOTLOADER 2391 bool "Use bootloader kernel arguments if available" 2392 help 2393 Uses the command-line options passed by the boot loader. If 2394 the boot loader doesn't provide any, the default kernel command 2395 string provided in CMDLINE will be used. 2396 2397config CMDLINE_FORCE 2398 bool "Always use the default kernel command string" 2399 help 2400 Always use the default kernel command string, even if the boot 2401 loader passes other arguments to the kernel. 2402 This is useful if you cannot or don't want to change the 2403 command-line options your boot loader passes to the kernel. 2404 2405endchoice 2406 2407config EFI_STUB 2408 bool 2409 2410config EFI 2411 bool "UEFI runtime support" 2412 depends on OF && !CPU_BIG_ENDIAN 2413 depends on KERNEL_MODE_NEON 2414 select ARCH_SUPPORTS_ACPI 2415 select LIBFDT 2416 select UCS2_STRING 2417 select EFI_PARAMS_FROM_FDT 2418 select EFI_RUNTIME_WRAPPERS 2419 select EFI_STUB 2420 select EFI_GENERIC_STUB 2421 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2422 default y 2423 help 2424 This option provides support for runtime services provided 2425 by UEFI firmware (such as non-volatile variables, realtime 2426 clock, and platform reset). A UEFI stub is also provided to 2427 allow the kernel to be booted as an EFI application. This 2428 is only useful on systems that have UEFI firmware. 2429 2430config COMPRESSED_INSTALL 2431 bool "Install compressed image by default" 2432 help 2433 This makes the regular "make install" install the compressed 2434 image we built, not the legacy uncompressed one. 2435 2436 You can check that a compressed image works for you by doing 2437 "make zinstall" first, and verifying that everything is fine 2438 in your environment before making "make install" do this for 2439 you. 2440 2441config DMI 2442 bool "Enable support for SMBIOS (DMI) tables" 2443 depends on EFI 2444 default y 2445 help 2446 This enables SMBIOS/DMI feature for systems. 2447 2448 This option is only useful on systems that have UEFI firmware. 2449 However, even with this option, the resultant kernel should 2450 continue to boot on existing non-UEFI platforms. 2451 2452endmenu # "Boot options" 2453 2454menu "Power management options" 2455 2456source "kernel/power/Kconfig" 2457 2458config ARCH_HIBERNATION_POSSIBLE 2459 def_bool y 2460 depends on CPU_PM 2461 2462config ARCH_HIBERNATION_HEADER 2463 def_bool y 2464 depends on HIBERNATION 2465 2466config ARCH_SUSPEND_POSSIBLE 2467 def_bool y 2468 2469endmenu # "Power management options" 2470 2471menu "CPU Power Management" 2472 2473source "drivers/cpuidle/Kconfig" 2474 2475source "drivers/cpufreq/Kconfig" 2476 2477endmenu # "CPU Power Management" 2478 2479source "drivers/acpi/Kconfig" 2480 2481source "arch/arm64/kvm/Kconfig" 2482 2483