1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CURRENT_STACK_POINTER 25 select ARCH_HAS_DEBUG_VIRTUAL 26 select ARCH_HAS_DEBUG_VM_PGTABLE 27 select ARCH_HAS_DMA_OPS if XEN 28 select ARCH_HAS_DMA_PREP_COHERENT 29 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 30 select ARCH_HAS_FAST_MULTIPLIER 31 select ARCH_HAS_FORTIFY_SOURCE 32 select ARCH_HAS_GCOV_PROFILE_ALL 33 select ARCH_HAS_GIGANTIC_PAGE 34 select ARCH_HAS_KCOV 35 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 36 select ARCH_HAS_KEEPINITRD 37 select ARCH_HAS_MEMBARRIER_SYNC_CORE 38 select ARCH_HAS_MEM_ENCRYPT 39 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 40 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 42 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 43 select ARCH_HAS_PREEMPT_LAZY 44 select ARCH_HAS_PTDUMP 45 select ARCH_HAS_PTE_SPECIAL 46 select ARCH_HAS_HW_PTE_YOUNG 47 select ARCH_HAS_SETUP_DMA_OPS 48 select ARCH_HAS_SET_DIRECT_MAP 49 select ARCH_HAS_SET_MEMORY 50 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 51 select ARCH_STACKWALK 52 select ARCH_HAS_STRICT_KERNEL_RWX 53 select ARCH_HAS_STRICT_MODULE_RWX 54 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 55 select ARCH_HAS_SYNC_DMA_FOR_CPU 56 select ARCH_HAS_SYSCALL_WRAPPER 57 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 58 select ARCH_HAS_ZONE_DMA_SET if EXPERT 59 select ARCH_HAVE_ELF_PROT 60 select ARCH_HAVE_NMI_SAFE_CMPXCHG 61 select ARCH_HAVE_TRACE_MMIO_ACCESS 62 select ARCH_INLINE_READ_LOCK if !PREEMPTION 63 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 64 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 66 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 67 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 70 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 71 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 74 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 75 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 78 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 79 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 80 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 81 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 84 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 85 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 88 select ARCH_KEEP_MEMBLOCK 89 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 90 select ARCH_USE_CMPXCHG_LOCKREF 91 select ARCH_USE_GNU_PROPERTY 92 select ARCH_USE_MEMTEST 93 select ARCH_USE_QUEUED_RWLOCKS 94 select ARCH_USE_QUEUED_SPINLOCKS 95 select ARCH_USE_SYM_ANNOTATIONS 96 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 97 select ARCH_SUPPORTS_HUGETLBFS 98 select ARCH_SUPPORTS_MEMORY_FAILURE 99 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 100 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 101 select ARCH_SUPPORTS_LTO_CLANG_THIN 102 select ARCH_SUPPORTS_CFI 103 select ARCH_SUPPORTS_ATOMIC_RMW 104 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 105 select ARCH_SUPPORTS_NUMA_BALANCING 106 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 107 select ARCH_SUPPORTS_PER_VMA_LOCK 108 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 109 select ARCH_SUPPORTS_RT 110 select ARCH_SUPPORTS_SCHED_SMT 111 select ARCH_SUPPORTS_SCHED_CLUSTER 112 select ARCH_SUPPORTS_SCHED_MC 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_GIC_V5 132 select ARM_PSCI_FW 133 select BUILDTIME_TABLE_SORT 134 select CLONE_BACKWARDS 135 select COMMON_CLK 136 select CPU_PM if (SUSPEND || CPU_IDLE) 137 select CPUMASK_OFFSTACK if NR_CPUS > 256 138 select DCACHE_WORD_ACCESS 139 select HAVE_EXTRA_IPI_TRACEPOINTS 140 select DYNAMIC_FTRACE if FUNCTION_TRACER 141 select DMA_BOUNCE_UNALIGNED_KMALLOC 142 select DMA_DIRECT_REMAP 143 select EDAC_SUPPORT 144 select FRAME_POINTER 145 select FUNCTION_ALIGNMENT_4B 146 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 147 select GENERIC_ALLOCATOR 148 select GENERIC_ARCH_TOPOLOGY 149 select GENERIC_CLOCKEVENTS_BROADCAST 150 select GENERIC_CPU_AUTOPROBE 151 select GENERIC_CPU_DEVICES 152 select GENERIC_CPU_VULNERABILITIES 153 select GENERIC_EARLY_IOREMAP 154 select GENERIC_IDLE_POLL_SETUP 155 select GENERIC_IOREMAP 156 select GENERIC_IRQ_ENTRY 157 select GENERIC_IRQ_IPI 158 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 159 select GENERIC_IRQ_PROBE 160 select GENERIC_IRQ_SHOW 161 select GENERIC_IRQ_SHOW_LEVEL 162 select GENERIC_LIB_DEVMEM_IS_ALLOWED 163 select GENERIC_PCI_IOMAP 164 select GENERIC_SCHED_CLOCK 165 select GENERIC_SMP_IDLE_THREAD 166 select GENERIC_TIME_VSYSCALL 167 select GENERIC_GETTIMEOFDAY 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_KSTACK_ERASE 191 select HAVE_ARCH_MMAP_RND_BITS 192 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 193 select HAVE_ARCH_PREL32_RELOCATIONS 194 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 195 select HAVE_ARCH_SECCOMP_FILTER 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 && \ 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_FUNCTION_TRACER 227 select HAVE_FUNCTION_ERROR_INJECTION 228 select HAVE_FUNCTION_GRAPH_FREGS 229 select HAVE_FUNCTION_GRAPH_TRACER 230 select HAVE_GCC_PLUGINS 231 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 232 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 233 select HAVE_HW_BREAKPOINT if PERF_EVENTS 234 select HAVE_IOREMAP_PROT 235 select HAVE_IRQ_TIME_ACCOUNTING 236 select HAVE_LIVEPATCH 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_RELIABLE_STACKTRACE 246 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 247 select HAVE_FUNCTION_ARG_ACCESS_API 248 select MMU_GATHER_RCU_TABLE_FREE 249 select HAVE_RSEQ 250 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 251 select HAVE_STACKPROTECTOR 252 select HAVE_SYSCALL_TRACEPOINTS 253 select HAVE_KPROBES 254 select HAVE_KRETPROBES 255 select HAVE_GENERIC_VDSO 256 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 257 select HOTPLUG_SMT if HOTPLUG_CPU 258 select IRQ_DOMAIN 259 select IRQ_FORCED_THREADING 260 select JUMP_LABEL 261 select KASAN_VMALLOC if KASAN 262 select LOCK_MM_AND_FIND_VMA 263 select MODULES_USE_ELF_RELA 264 select NEED_DMA_MAP_STATE 265 select NEED_SG_DMA_LENGTH 266 select OF 267 select OF_EARLY_FLATTREE 268 select PCI_DOMAINS_GENERIC if PCI 269 select PCI_ECAM if (ACPI && PCI) 270 select PCI_SYSCALL if PCI 271 select POWER_RESET 272 select POWER_SUPPLY 273 select SPARSE_IRQ 274 select SWIOTLB 275 select SYSCTL_EXCEPTION_TRACE 276 select THREAD_INFO_IN_TASK 277 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 278 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 279 select TRACE_IRQFLAGS_SUPPORT 280 select TRACE_IRQFLAGS_NMI_SUPPORT 281 select HAVE_SOFTIRQ_ON_OWN_STACK 282 select USER_STACKTRACE_SUPPORT 283 select VDSO_GETRANDOM 284 select VMAP_STACK 285 help 286 ARM 64-bit (AArch64) Linux support. 287 288config RUSTC_SUPPORTS_ARM64 289 def_bool y 290 depends on CPU_LITTLE_ENDIAN 291 # Shadow call stack is only supported on certain rustc versions. 292 # 293 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 294 # required due to use of the -Zfixed-x18 flag. 295 # 296 # Otherwise, rustc version 1.82+ is required due to use of the 297 # -Zsanitizer=shadow-call-stack flag. 298 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 299 300config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 301 def_bool CC_IS_CLANG 302 # https://github.com/ClangBuiltLinux/linux/issues/1507 303 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 304 305config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 306 def_bool CC_IS_GCC 307 depends on $(cc-option,-fpatchable-function-entry=2) 308 309config 64BIT 310 def_bool y 311 312config MMU 313 def_bool y 314 315config ARM64_CONT_PTE_SHIFT 316 int 317 default 5 if PAGE_SIZE_64KB 318 default 7 if PAGE_SIZE_16KB 319 default 4 320 321config ARM64_CONT_PMD_SHIFT 322 int 323 default 5 if PAGE_SIZE_64KB 324 default 5 if PAGE_SIZE_16KB 325 default 4 326 327config ARCH_MMAP_RND_BITS_MIN 328 default 14 if PAGE_SIZE_64KB 329 default 16 if PAGE_SIZE_16KB 330 default 18 331 332# max bits determined by the following formula: 333# VA_BITS - PTDESC_TABLE_SHIFT 334config ARCH_MMAP_RND_BITS_MAX 335 default 19 if ARM64_VA_BITS=36 336 default 24 if ARM64_VA_BITS=39 337 default 27 if ARM64_VA_BITS=42 338 default 30 if ARM64_VA_BITS=47 339 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 340 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 341 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 342 default 14 if ARM64_64K_PAGES 343 default 16 if ARM64_16K_PAGES 344 default 18 345 346config ARCH_MMAP_RND_COMPAT_BITS_MIN 347 default 7 if ARM64_64K_PAGES 348 default 9 if ARM64_16K_PAGES 349 default 11 350 351config ARCH_MMAP_RND_COMPAT_BITS_MAX 352 default 16 353 354config NO_IOPORT_MAP 355 def_bool y if !PCI 356 357config STACKTRACE_SUPPORT 358 def_bool y 359 360config ILLEGAL_POINTER_VALUE 361 hex 362 default 0xdead000000000000 363 364config LOCKDEP_SUPPORT 365 def_bool y 366 367config GENERIC_BUG 368 def_bool y 369 depends on BUG 370 371config GENERIC_BUG_RELATIVE_POINTERS 372 def_bool y 373 depends on GENERIC_BUG 374 375config GENERIC_HWEIGHT 376 def_bool y 377 378config GENERIC_CSUM 379 def_bool y 380 381config GENERIC_CALIBRATE_DELAY 382 def_bool y 383 384config SMP 385 def_bool y 386 387config KERNEL_MODE_NEON 388 def_bool y 389 390config FIX_EARLYCON_MEM 391 def_bool y 392 393config PGTABLE_LEVELS 394 int 395 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 396 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 397 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 398 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 399 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 400 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 401 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 402 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 403 404config ARCH_SUPPORTS_UPROBES 405 def_bool y 406 407config ARCH_PROC_KCORE_TEXT 408 def_bool y 409 410config BROKEN_GAS_INST 411 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 412 413config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 414 bool 415 # Clang's __builtin_return_address() strips the PAC since 12.0.0 416 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 417 default y if CC_IS_CLANG 418 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 419 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 420 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 421 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 422 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 423 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 424 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 425 default n 426 427config KASAN_SHADOW_OFFSET 428 hex 429 depends on KASAN_GENERIC || KASAN_SW_TAGS 430 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 431 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 432 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 433 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 434 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 435 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 436 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 437 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 438 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 439 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 440 default 0xffffffffffffffff 441 442config UNWIND_TABLES 443 bool 444 445source "arch/arm64/Kconfig.platforms" 446 447menu "Kernel Features" 448 449menu "ARM errata workarounds via the alternatives framework" 450 451config AMPERE_ERRATUM_AC03_CPU_38 452 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 453 default y 454 help 455 This option adds an alternative code sequence to work around Ampere 456 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 457 458 The affected design reports FEAT_HAFDBS as not implemented in 459 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 460 as required by the architecture. The unadvertised HAFDBS 461 implementation suffers from an additional erratum where hardware 462 A/D updates can occur after a PTE has been marked invalid. 463 464 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 465 which avoids enabling unadvertised hardware Access Flag management 466 at stage-2. 467 468 If unsure, say Y. 469 470config AMPERE_ERRATUM_AC04_CPU_23 471 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 472 default y 473 help 474 This option adds an alternative code sequence to work around Ampere 475 errata AC04_CPU_23 on AmpereOne. 476 477 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 478 data addresses initiated by load/store instructions. Only 479 instruction initiated translations are vulnerable, not translations 480 from prefetches for example. A DSB before the store to HCR_EL2 is 481 sufficient to prevent older instructions from hitting the window 482 for corruption, and an ISB after is sufficient to prevent younger 483 instructions from hitting the window for corruption. 484 485 If unsure, say Y. 486 487config ARM64_WORKAROUND_CLEAN_CACHE 488 bool 489 490config ARM64_ERRATUM_826319 491 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 492 default y 493 select ARM64_WORKAROUND_CLEAN_CACHE 494 help 495 This option adds an alternative code sequence to work around ARM 496 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 497 AXI master interface and an L2 cache. 498 499 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 500 and is unable to accept a certain write via this interface, it will 501 not progress on read data presented on the read data channel and the 502 system can deadlock. 503 504 The workaround promotes data cache clean instructions to 505 data cache clean-and-invalidate. 506 Please note that this does not necessarily enable the workaround, 507 as it depends on the alternative framework, which will only patch 508 the kernel if an affected CPU is detected. 509 510 If unsure, say Y. 511 512config ARM64_ERRATUM_827319 513 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 514 default y 515 select ARM64_WORKAROUND_CLEAN_CACHE 516 help 517 This option adds an alternative code sequence to work around ARM 518 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 519 master interface and an L2 cache. 520 521 Under certain conditions this erratum can cause a clean line eviction 522 to occur at the same time as another transaction to the same address 523 on the AMBA 5 CHI interface, which can cause data corruption if the 524 interconnect reorders the two transactions. 525 526 The workaround promotes data cache clean instructions to 527 data cache clean-and-invalidate. 528 Please note that this does not necessarily enable the workaround, 529 as it depends on the alternative framework, which will only patch 530 the kernel if an affected CPU is detected. 531 532 If unsure, say Y. 533 534config ARM64_ERRATUM_824069 535 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 536 default y 537 select ARM64_WORKAROUND_CLEAN_CACHE 538 help 539 This option adds an alternative code sequence to work around ARM 540 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 541 to a coherent interconnect. 542 543 If a Cortex-A53 processor is executing a store or prefetch for 544 write instruction at the same time as a processor in another 545 cluster is executing a cache maintenance operation to the same 546 address, then this erratum might cause a clean cache line to be 547 incorrectly marked as dirty. 548 549 The workaround promotes data cache clean instructions to 550 data cache clean-and-invalidate. 551 Please note that this option does not necessarily enable the 552 workaround, as it depends on the alternative framework, which will 553 only patch the kernel if an affected CPU is detected. 554 555 If unsure, say Y. 556 557config ARM64_ERRATUM_819472 558 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 559 default y 560 select ARM64_WORKAROUND_CLEAN_CACHE 561 help 562 This option adds an alternative code sequence to work around ARM 563 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 564 present when it is connected to a coherent interconnect. 565 566 If the processor is executing a load and store exclusive sequence at 567 the same time as a processor in another cluster is executing a cache 568 maintenance operation to the same address, then this erratum might 569 cause data corruption. 570 571 The workaround promotes data cache clean instructions to 572 data cache clean-and-invalidate. 573 Please note that this does not necessarily enable the workaround, 574 as it depends on the alternative framework, which will only patch 575 the kernel if an affected CPU is detected. 576 577 If unsure, say Y. 578 579config ARM64_ERRATUM_832075 580 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 581 default y 582 help 583 This option adds an alternative code sequence to work around ARM 584 erratum 832075 on Cortex-A57 parts up to r1p2. 585 586 Affected Cortex-A57 parts might deadlock when exclusive load/store 587 instructions to Write-Back memory are mixed with Device loads. 588 589 The workaround is to promote device loads to use Load-Acquire 590 semantics. 591 Please note that this does not necessarily enable the workaround, 592 as it depends on the alternative framework, which will only patch 593 the kernel if an affected CPU is detected. 594 595 If unsure, say Y. 596 597config ARM64_ERRATUM_834220 598 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 599 depends on KVM 600 help 601 This option adds an alternative code sequence to work around ARM 602 erratum 834220 on Cortex-A57 parts up to r1p2. 603 604 Affected Cortex-A57 parts might report a Stage 2 translation 605 fault as the result of a Stage 1 fault for load crossing a 606 page boundary when there is a permission or device memory 607 alignment fault at Stage 1 and a translation fault at Stage 2. 608 609 The workaround is to verify that the Stage 1 translation 610 doesn't generate a fault before handling the Stage 2 fault. 611 Please note that this does not necessarily enable the workaround, 612 as it depends on the alternative framework, which will only patch 613 the kernel if an affected CPU is detected. 614 615 If unsure, say N. 616 617config ARM64_ERRATUM_1742098 618 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 619 depends on COMPAT 620 default y 621 help 622 This option removes the AES hwcap for aarch32 user-space to 623 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 624 625 Affected parts may corrupt the AES state if an interrupt is 626 taken between a pair of AES instructions. These instructions 627 are only present if the cryptography extensions are present. 628 All software should have a fallback implementation for CPUs 629 that don't implement the cryptography extensions. 630 631 If unsure, say Y. 632 633config ARM64_ERRATUM_845719 634 bool "Cortex-A53: 845719: a load might read incorrect data" 635 depends on COMPAT 636 default y 637 help 638 This option adds an alternative code sequence to work around ARM 639 erratum 845719 on Cortex-A53 parts up to r0p4. 640 641 When running a compat (AArch32) userspace on an affected Cortex-A53 642 part, a load at EL0 from a virtual address that matches the bottom 32 643 bits of the virtual address used by a recent load at (AArch64) EL1 644 might return incorrect data. 645 646 The workaround is to write the contextidr_el1 register on exception 647 return to a 32-bit task. 648 Please note that this does not necessarily enable the workaround, 649 as it depends on the alternative framework, which will only patch 650 the kernel if an affected CPU is detected. 651 652 If unsure, say Y. 653 654config ARM64_ERRATUM_843419 655 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 656 default y 657 help 658 This option links the kernel with '--fix-cortex-a53-843419' and 659 enables PLT support to replace certain ADRP instructions, which can 660 cause subsequent memory accesses to use an incorrect address on 661 Cortex-A53 parts up to r0p4. 662 663 If unsure, say Y. 664 665config ARM64_ERRATUM_1024718 666 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 667 default y 668 help 669 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 670 671 Affected Cortex-A55 cores (all revisions) could cause incorrect 672 update of the hardware dirty bit when the DBM/AP bits are updated 673 without a break-before-make. The workaround is to disable the usage 674 of hardware DBM locally on the affected cores. CPUs not affected by 675 this erratum will continue to use the feature. 676 677 If unsure, say Y. 678 679config ARM64_ERRATUM_1418040 680 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 681 default y 682 depends on COMPAT 683 help 684 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 685 errata 1188873 and 1418040. 686 687 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 688 cause register corruption when accessing the timer registers 689 from AArch32 userspace. 690 691 If unsure, say Y. 692 693config ARM64_WORKAROUND_SPECULATIVE_AT 694 bool 695 696config ARM64_ERRATUM_1165522 697 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 698 default y 699 select ARM64_WORKAROUND_SPECULATIVE_AT 700 help 701 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 702 703 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 704 corrupted TLBs by speculating an AT instruction during a guest 705 context switch. 706 707 If unsure, say Y. 708 709config ARM64_ERRATUM_1319367 710 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 711 default y 712 select ARM64_WORKAROUND_SPECULATIVE_AT 713 help 714 This option adds work arounds for ARM Cortex-A57 erratum 1319537 715 and A72 erratum 1319367 716 717 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 718 speculating an AT instruction during a guest context switch. 719 720 If unsure, say Y. 721 722config ARM64_ERRATUM_1530923 723 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 724 default y 725 select ARM64_WORKAROUND_SPECULATIVE_AT 726 help 727 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 728 729 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 730 corrupted TLBs by speculating an AT instruction during a guest 731 context switch. 732 733 If unsure, say Y. 734 735config ARM64_WORKAROUND_REPEAT_TLBI 736 bool 737 738config ARM64_ERRATUM_2441007 739 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 740 select ARM64_WORKAROUND_REPEAT_TLBI 741 help 742 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 743 744 Under very rare circumstances, affected Cortex-A55 CPUs 745 may not handle a race between a break-before-make sequence on one 746 CPU, and another CPU accessing the same page. This could allow a 747 store to a page that has been unmapped. 748 749 Work around this by adding the affected CPUs to the list that needs 750 TLB sequences to be done twice. 751 752 If unsure, say N. 753 754config ARM64_ERRATUM_1286807 755 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 756 select ARM64_WORKAROUND_REPEAT_TLBI 757 help 758 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 759 760 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 761 address for a cacheable mapping of a location is being 762 accessed by a core while another core is remapping the virtual 763 address to a new physical page using the recommended 764 break-before-make sequence, then under very rare circumstances 765 TLBI+DSB completes before a read using the translation being 766 invalidated has been observed by other observers. The 767 workaround repeats the TLBI+DSB operation. 768 769 If unsure, say N. 770 771config ARM64_ERRATUM_1463225 772 bool "Cortex-A76: Software Step might prevent interrupt recognition" 773 default y 774 help 775 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 776 777 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 778 of a system call instruction (SVC) can prevent recognition of 779 subsequent interrupts when software stepping is disabled in the 780 exception handler of the system call and either kernel debugging 781 is enabled or VHE is in use. 782 783 Work around the erratum by triggering a dummy step exception 784 when handling a system call from a task that is being stepped 785 in a VHE configuration of the kernel. 786 787 If unsure, say Y. 788 789config ARM64_ERRATUM_1542419 790 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 791 help 792 This option adds a workaround for ARM Neoverse-N1 erratum 793 1542419. 794 795 Affected Neoverse-N1 cores could execute a stale instruction when 796 modified by another CPU. The workaround depends on a firmware 797 counterpart. 798 799 Workaround the issue by hiding the DIC feature from EL0. This 800 forces user-space to perform cache maintenance. 801 802 If unsure, say N. 803 804config ARM64_ERRATUM_1508412 805 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 806 default y 807 help 808 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 809 810 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 811 of a store-exclusive or read of PAR_EL1 and a load with device or 812 non-cacheable memory attributes. The workaround depends on a firmware 813 counterpart. 814 815 KVM guests must also have the workaround implemented or they can 816 deadlock the system. 817 818 Work around the issue by inserting DMB SY barriers around PAR_EL1 819 register reads and warning KVM users. The DMB barrier is sufficient 820 to prevent a speculative PAR_EL1 read. 821 822 If unsure, say Y. 823 824config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 825 bool 826 827config ARM64_ERRATUM_2051678 828 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 829 default y 830 help 831 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 832 Affected Cortex-A510 might not respect the ordering rules for 833 hardware update of the page table's dirty bit. The workaround 834 is to not enable the feature on affected CPUs. 835 836 If unsure, say Y. 837 838config ARM64_ERRATUM_2077057 839 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 840 default y 841 help 842 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 843 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 844 expected, but a Pointer Authentication trap is taken instead. The 845 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 846 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 847 848 This can only happen when EL2 is stepping EL1. 849 850 When these conditions occur, the SPSR_EL2 value is unchanged from the 851 previous guest entry, and can be restored from the in-memory copy. 852 853 If unsure, say Y. 854 855config ARM64_ERRATUM_2658417 856 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 857 default y 858 help 859 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 860 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 861 BFMMLA or VMMLA instructions in rare circumstances when a pair of 862 A510 CPUs are using shared neon hardware. As the sharing is not 863 discoverable by the kernel, hide the BF16 HWCAP to indicate that 864 user-space should not be using these instructions. 865 866 If unsure, say Y. 867 868config ARM64_ERRATUM_2119858 869 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 870 default y 871 depends on CORESIGHT_TRBE 872 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 873 help 874 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 875 876 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 877 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 878 the event of a WRAP event. 879 880 Work around the issue by always making sure we move the TRBPTR_EL1 by 881 256 bytes before enabling the buffer and filling the first 256 bytes of 882 the buffer with ETM ignore packets upon disabling. 883 884 If unsure, say Y. 885 886config ARM64_ERRATUM_2139208 887 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 888 default y 889 depends on CORESIGHT_TRBE 890 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 891 help 892 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 893 894 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 895 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 896 the event of a WRAP event. 897 898 Work around the issue by always making sure we move the TRBPTR_EL1 by 899 256 bytes before enabling the buffer and filling the first 256 bytes of 900 the buffer with ETM ignore packets upon disabling. 901 902 If unsure, say Y. 903 904config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 905 bool 906 907config ARM64_ERRATUM_2054223 908 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 909 default y 910 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 911 help 912 Enable workaround for ARM Cortex-A710 erratum 2054223 913 914 Affected cores may fail to flush the trace data on a TSB instruction, when 915 the PE is in trace prohibited state. This will cause losing a few bytes 916 of the trace cached. 917 918 Workaround is to issue two TSB consecutively on affected cores. 919 920 If unsure, say Y. 921 922config ARM64_ERRATUM_2067961 923 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 924 default y 925 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 926 help 927 Enable workaround for ARM Neoverse-N2 erratum 2067961 928 929 Affected cores may fail to flush the trace data on a TSB instruction, when 930 the PE is in trace prohibited state. This will cause losing a few bytes 931 of the trace cached. 932 933 Workaround is to issue two TSB consecutively on affected cores. 934 935 If unsure, say Y. 936 937config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 938 bool 939 940config ARM64_ERRATUM_2253138 941 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 942 depends on CORESIGHT_TRBE 943 default y 944 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 945 help 946 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 947 948 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 949 for TRBE. Under some conditions, the TRBE might generate a write to the next 950 virtually addressed page following the last page of the TRBE address space 951 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 952 953 Work around this in the driver by always making sure that there is a 954 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 955 956 If unsure, say Y. 957 958config ARM64_ERRATUM_2224489 959 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 960 depends on CORESIGHT_TRBE 961 default y 962 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 963 help 964 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 965 966 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 967 for TRBE. Under some conditions, the TRBE might generate a write to the next 968 virtually addressed page following the last page of the TRBE address space 969 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 970 971 Work around this in the driver by always making sure that there is a 972 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 973 974 If unsure, say Y. 975 976config ARM64_ERRATUM_2441009 977 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 978 select ARM64_WORKAROUND_REPEAT_TLBI 979 help 980 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 981 982 Under very rare circumstances, affected Cortex-A510 CPUs 983 may not handle a race between a break-before-make sequence on one 984 CPU, and another CPU accessing the same page. This could allow a 985 store to a page that has been unmapped. 986 987 Work around this by adding the affected CPUs to the list that needs 988 TLB sequences to be done twice. 989 990 If unsure, say N. 991 992config ARM64_ERRATUM_2064142 993 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 994 depends on CORESIGHT_TRBE 995 default y 996 help 997 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 998 999 Affected Cortex-A510 core might fail to write into system registers after the 1000 TRBE has been disabled. Under some conditions after the TRBE has been disabled 1001 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 1002 and TRBTRG_EL1 will be ignored and will not be effected. 1003 1004 Work around this in the driver by executing TSB CSYNC and DSB after collection 1005 is stopped and before performing a system register write to one of the affected 1006 registers. 1007 1008 If unsure, say Y. 1009 1010config ARM64_ERRATUM_2038923 1011 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1012 depends on CORESIGHT_TRBE 1013 default y 1014 help 1015 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1016 1017 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1018 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1019 might be corrupted. This happens after TRBE buffer has been enabled by setting 1020 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1021 execution changes from a context, in which trace is prohibited to one where it 1022 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1023 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1024 the trace buffer state might be corrupted. 1025 1026 Work around this in the driver by preventing an inconsistent view of whether the 1027 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1028 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1029 two ISB instructions if no ERET is to take place. 1030 1031 If unsure, say Y. 1032 1033config ARM64_ERRATUM_1902691 1034 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1035 depends on CORESIGHT_TRBE 1036 default y 1037 help 1038 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1039 1040 Affected Cortex-A510 core might cause trace data corruption, when being written 1041 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1042 trace data. 1043 1044 Work around this problem in the driver by just preventing TRBE initialization on 1045 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1046 on such implementations. This will cover the kernel for any firmware that doesn't 1047 do this already. 1048 1049 If unsure, say Y. 1050 1051config ARM64_ERRATUM_2457168 1052 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1053 depends on ARM64_AMU_EXTN 1054 default y 1055 help 1056 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1057 1058 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1059 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1060 incorrectly giving a significantly higher output value. 1061 1062 Work around this problem by returning 0 when reading the affected counter in 1063 key locations that results in disabling all users of this counter. This effect 1064 is the same to firmware disabling affected counters. 1065 1066 If unsure, say Y. 1067 1068config ARM64_ERRATUM_2645198 1069 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1070 default y 1071 help 1072 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1073 1074 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1075 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1076 next instruction abort caused by permission fault. 1077 1078 Only user-space does executable to non-executable permission transition via 1079 mprotect() system call. Workaround the problem by doing a break-before-make 1080 TLB invalidation, for all changes to executable user space mappings. 1081 1082 If unsure, say Y. 1083 1084config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1085 bool 1086 1087config ARM64_ERRATUM_2966298 1088 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1089 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1090 default y 1091 help 1092 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1093 1094 On an affected Cortex-A520 core, a speculatively executed unprivileged 1095 load might leak data from a privileged level via a cache side channel. 1096 1097 Work around this problem by executing a TLBI before returning to EL0. 1098 1099 If unsure, say Y. 1100 1101config ARM64_ERRATUM_3117295 1102 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1103 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1104 default y 1105 help 1106 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1107 1108 On an affected Cortex-A510 core, a speculatively executed unprivileged 1109 load might leak data from a privileged level via a cache side channel. 1110 1111 Work around this problem by executing a TLBI before returning to EL0. 1112 1113 If unsure, say Y. 1114 1115config ARM64_ERRATUM_3194386 1116 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1117 default y 1118 help 1119 This option adds the workaround for the following errata: 1120 1121 * ARM Cortex-A76 erratum 3324349 1122 * ARM Cortex-A77 erratum 3324348 1123 * ARM Cortex-A78 erratum 3324344 1124 * ARM Cortex-A78C erratum 3324346 1125 * ARM Cortex-A78C erratum 3324347 1126 * ARM Cortex-A710 erratam 3324338 1127 * ARM Cortex-A715 errartum 3456084 1128 * ARM Cortex-A720 erratum 3456091 1129 * ARM Cortex-A725 erratum 3456106 1130 * ARM Cortex-X1 erratum 3324344 1131 * ARM Cortex-X1C erratum 3324346 1132 * ARM Cortex-X2 erratum 3324338 1133 * ARM Cortex-X3 erratum 3324335 1134 * ARM Cortex-X4 erratum 3194386 1135 * ARM Cortex-X925 erratum 3324334 1136 * ARM Neoverse-N1 erratum 3324349 1137 * ARM Neoverse N2 erratum 3324339 1138 * ARM Neoverse-N3 erratum 3456111 1139 * ARM Neoverse-V1 erratum 3324341 1140 * ARM Neoverse V2 erratum 3324336 1141 * ARM Neoverse-V3 erratum 3312417 1142 * ARM Neoverse-V3AE erratum 3312417 1143 1144 On affected cores "MSR SSBS, #0" instructions may not affect 1145 subsequent speculative instructions, which may permit unexepected 1146 speculative store bypassing. 1147 1148 Work around this problem by placing a Speculation Barrier (SB) or 1149 Instruction Synchronization Barrier (ISB) after kernel changes to 1150 SSBS. The presence of the SSBS special-purpose register is hidden 1151 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1152 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1153 1154 If unsure, say Y. 1155 1156config CAVIUM_ERRATUM_22375 1157 bool "Cavium erratum 22375, 24313" 1158 default y 1159 help 1160 Enable workaround for errata 22375 and 24313. 1161 1162 This implements two gicv3-its errata workarounds for ThunderX. Both 1163 with a small impact affecting only ITS table allocation. 1164 1165 erratum 22375: only alloc 8MB table size 1166 erratum 24313: ignore memory access type 1167 1168 The fixes are in ITS initialization and basically ignore memory access 1169 type and table size provided by the TYPER and BASER registers. 1170 1171 If unsure, say Y. 1172 1173config CAVIUM_ERRATUM_23144 1174 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1175 depends on NUMA 1176 default y 1177 help 1178 ITS SYNC command hang for cross node io and collections/cpu mapping. 1179 1180 If unsure, say Y. 1181 1182config CAVIUM_ERRATUM_23154 1183 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1184 default y 1185 help 1186 The ThunderX GICv3 implementation requires a modified version for 1187 reading the IAR status to ensure data synchronization 1188 (access to icc_iar1_el1 is not sync'ed before and after). 1189 1190 It also suffers from erratum 38545 (also present on Marvell's 1191 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1192 spuriously presented to the CPU interface. 1193 1194 If unsure, say Y. 1195 1196config CAVIUM_ERRATUM_27456 1197 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1198 default y 1199 help 1200 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1201 instructions may cause the icache to become corrupted if it 1202 contains data for a non-current ASID. The fix is to 1203 invalidate the icache when changing the mm context. 1204 1205 If unsure, say Y. 1206 1207config CAVIUM_ERRATUM_30115 1208 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1209 default y 1210 help 1211 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1212 1.2, and T83 Pass 1.0, KVM guest execution may disable 1213 interrupts in host. Trapping both GICv3 group-0 and group-1 1214 accesses sidesteps the issue. 1215 1216 If unsure, say Y. 1217 1218config CAVIUM_TX2_ERRATUM_219 1219 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1220 default y 1221 help 1222 On Cavium ThunderX2, a load, store or prefetch instruction between a 1223 TTBR update and the corresponding context synchronizing operation can 1224 cause a spurious Data Abort to be delivered to any hardware thread in 1225 the CPU core. 1226 1227 Work around the issue by avoiding the problematic code sequence and 1228 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1229 trap handler performs the corresponding register access, skips the 1230 instruction and ensures context synchronization by virtue of the 1231 exception return. 1232 1233 If unsure, say Y. 1234 1235config FUJITSU_ERRATUM_010001 1236 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1237 default y 1238 help 1239 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1240 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1241 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1242 This fault occurs under a specific hardware condition when a 1243 load/store instruction performs an address translation using: 1244 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1245 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1246 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1247 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1248 1249 The workaround is to ensure these bits are clear in TCR_ELx. 1250 The workaround only affects the Fujitsu-A64FX. 1251 1252 If unsure, say Y. 1253 1254config HISILICON_ERRATUM_161600802 1255 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1256 default y 1257 help 1258 The HiSilicon Hip07 SoC uses the wrong redistributor base 1259 when issued ITS commands such as VMOVP and VMAPP, and requires 1260 a 128kB offset to be applied to the target address in this commands. 1261 1262 If unsure, say Y. 1263 1264config HISILICON_ERRATUM_162100801 1265 bool "Hip09 162100801 erratum support" 1266 default y 1267 help 1268 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1269 during unmapping operation, which will cause some vSGIs lost. 1270 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1271 after VMOVP. 1272 1273 If unsure, say Y. 1274 1275config QCOM_FALKOR_ERRATUM_1003 1276 bool "Falkor E1003: Incorrect translation due to ASID change" 1277 default y 1278 help 1279 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1280 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1281 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1282 then only for entries in the walk cache, since the leaf translation 1283 is unchanged. Work around the erratum by invalidating the walk cache 1284 entries for the trampoline before entering the kernel proper. 1285 1286config QCOM_FALKOR_ERRATUM_1009 1287 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1288 default y 1289 select ARM64_WORKAROUND_REPEAT_TLBI 1290 help 1291 On Falkor v1, the CPU may prematurely complete a DSB following a 1292 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1293 one more time to fix the issue. 1294 1295 If unsure, say Y. 1296 1297config QCOM_QDF2400_ERRATUM_0065 1298 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1299 default y 1300 help 1301 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1302 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1303 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1304 1305 If unsure, say Y. 1306 1307config QCOM_FALKOR_ERRATUM_E1041 1308 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1309 default y 1310 help 1311 Falkor CPU may speculatively fetch instructions from an improper 1312 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1313 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1314 1315 If unsure, say Y. 1316 1317config NVIDIA_CARMEL_CNP_ERRATUM 1318 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1319 default y 1320 help 1321 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1322 invalidate shared TLB entries installed by a different core, as it would 1323 on standard ARM cores. 1324 1325 If unsure, say Y. 1326 1327config ROCKCHIP_ERRATUM_3568002 1328 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1329 default y 1330 help 1331 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1332 addressing limited to the first 32bit of physical address space. 1333 1334 If unsure, say Y. 1335 1336config ROCKCHIP_ERRATUM_3588001 1337 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1338 default y 1339 help 1340 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1341 This means, that its sharability feature may not be used, even though it 1342 is supported by the IP itself. 1343 1344 If unsure, say Y. 1345 1346config SOCIONEXT_SYNQUACER_PREITS 1347 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1348 default y 1349 help 1350 Socionext Synquacer SoCs implement a separate h/w block to generate 1351 MSI doorbell writes with non-zero values for the device ID. 1352 1353 If unsure, say Y. 1354 1355endmenu # "ARM errata workarounds via the alternatives framework" 1356 1357choice 1358 prompt "Page size" 1359 default ARM64_4K_PAGES 1360 help 1361 Page size (translation granule) configuration. 1362 1363config ARM64_4K_PAGES 1364 bool "4KB" 1365 select HAVE_PAGE_SIZE_4KB 1366 help 1367 This feature enables 4KB pages support. 1368 1369config ARM64_16K_PAGES 1370 bool "16KB" 1371 select HAVE_PAGE_SIZE_16KB 1372 help 1373 The system will use 16KB pages support. AArch32 emulation 1374 requires applications compiled with 16K (or a multiple of 16K) 1375 aligned segments. 1376 1377config ARM64_64K_PAGES 1378 bool "64KB" 1379 select HAVE_PAGE_SIZE_64KB 1380 help 1381 This feature enables 64KB pages support (4KB by default) 1382 allowing only two levels of page tables and faster TLB 1383 look-up. AArch32 emulation requires applications compiled 1384 with 64K aligned segments. 1385 1386endchoice 1387 1388choice 1389 prompt "Virtual address space size" 1390 default ARM64_VA_BITS_52 1391 help 1392 Allows choosing one of multiple possible virtual address 1393 space sizes. The level of translation table is determined by 1394 a combination of page size and virtual address space size. 1395 1396config ARM64_VA_BITS_36 1397 bool "36-bit" if EXPERT 1398 depends on PAGE_SIZE_16KB 1399 1400config ARM64_VA_BITS_39 1401 bool "39-bit" 1402 depends on PAGE_SIZE_4KB 1403 1404config ARM64_VA_BITS_42 1405 bool "42-bit" 1406 depends on PAGE_SIZE_64KB 1407 1408config ARM64_VA_BITS_47 1409 bool "47-bit" 1410 depends on PAGE_SIZE_16KB 1411 1412config ARM64_VA_BITS_48 1413 bool "48-bit" 1414 1415config ARM64_VA_BITS_52 1416 bool "52-bit" 1417 help 1418 Enable 52-bit virtual addressing for userspace when explicitly 1419 requested via a hint to mmap(). The kernel will also use 52-bit 1420 virtual addresses for its own mappings (provided HW support for 1421 this feature is available, otherwise it reverts to 48-bit). 1422 1423 NOTE: Enabling 52-bit virtual addressing in conjunction with 1424 ARMv8.3 Pointer Authentication will result in the PAC being 1425 reduced from 7 bits to 3 bits, which may have a significant 1426 impact on its susceptibility to brute-force attacks. 1427 1428 If unsure, select 48-bit virtual addressing instead. 1429 1430endchoice 1431 1432config ARM64_FORCE_52BIT 1433 bool "Force 52-bit virtual addresses for userspace" 1434 depends on ARM64_VA_BITS_52 && EXPERT 1435 help 1436 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1437 to maintain compatibility with older software by providing 48-bit VAs 1438 unless a hint is supplied to mmap. 1439 1440 This configuration option disables the 48-bit compatibility logic, and 1441 forces all userspace addresses to be 52-bit on HW that supports it. One 1442 should only enable this configuration option for stress testing userspace 1443 memory management code. If unsure say N here. 1444 1445config ARM64_VA_BITS 1446 int 1447 default 36 if ARM64_VA_BITS_36 1448 default 39 if ARM64_VA_BITS_39 1449 default 42 if ARM64_VA_BITS_42 1450 default 47 if ARM64_VA_BITS_47 1451 default 48 if ARM64_VA_BITS_48 1452 default 52 if ARM64_VA_BITS_52 1453 1454choice 1455 prompt "Physical address space size" 1456 default ARM64_PA_BITS_48 1457 help 1458 Choose the maximum physical address range that the kernel will 1459 support. 1460 1461config ARM64_PA_BITS_48 1462 bool "48-bit" 1463 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1464 1465config ARM64_PA_BITS_52 1466 bool "52-bit" 1467 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1468 help 1469 Enable support for a 52-bit physical address space, introduced as 1470 part of the ARMv8.2-LPA extension. 1471 1472 With this enabled, the kernel will also continue to work on CPUs that 1473 do not support ARMv8.2-LPA, but with some added memory overhead (and 1474 minor performance overhead). 1475 1476endchoice 1477 1478config ARM64_PA_BITS 1479 int 1480 default 48 if ARM64_PA_BITS_48 1481 default 52 if ARM64_PA_BITS_52 1482 1483config ARM64_LPA2 1484 def_bool y 1485 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1486 1487choice 1488 prompt "Endianness" 1489 default CPU_LITTLE_ENDIAN 1490 help 1491 Select the endianness of data accesses performed by the CPU. Userspace 1492 applications will need to be compiled and linked for the endianness 1493 that is selected here. 1494 1495config CPU_BIG_ENDIAN 1496 bool "Build big-endian kernel" 1497 depends on BROKEN 1498 help 1499 Say Y if you plan on running a kernel with a big-endian userspace. 1500 1501config CPU_LITTLE_ENDIAN 1502 bool "Build little-endian kernel" 1503 help 1504 Say Y if you plan on running a kernel with a little-endian userspace. 1505 This is usually the case for distributions targeting arm64. 1506 1507endchoice 1508 1509config NR_CPUS 1510 int "Maximum number of CPUs (2-4096)" 1511 range 2 4096 1512 default "512" 1513 1514config HOTPLUG_CPU 1515 bool "Support for hot-pluggable CPUs" 1516 select GENERIC_IRQ_MIGRATION 1517 help 1518 Say Y here to experiment with turning CPUs off and on. CPUs 1519 can be controlled through /sys/devices/system/cpu. 1520 1521# Common NUMA Features 1522config NUMA 1523 bool "NUMA Memory Allocation and Scheduler Support" 1524 select GENERIC_ARCH_NUMA 1525 select OF_NUMA 1526 select HAVE_SETUP_PER_CPU_AREA 1527 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1528 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1529 select USE_PERCPU_NUMA_NODE_ID 1530 help 1531 Enable NUMA (Non-Uniform Memory Access) support. 1532 1533 The kernel will try to allocate memory used by a CPU on the 1534 local memory of the CPU and add some more 1535 NUMA awareness to the kernel. 1536 1537config NODES_SHIFT 1538 int "Maximum NUMA Nodes (as a power of 2)" 1539 range 1 10 1540 default "4" 1541 depends on NUMA 1542 help 1543 Specify the maximum number of NUMA Nodes available on the target 1544 system. Increases memory reserved to accommodate various tables. 1545 1546source "kernel/Kconfig.hz" 1547 1548config ARCH_SPARSEMEM_ENABLE 1549 def_bool y 1550 select SPARSEMEM_VMEMMAP_ENABLE 1551 1552config HW_PERF_EVENTS 1553 def_bool y 1554 depends on ARM_PMU 1555 1556# Supported by clang >= 7.0 or GCC >= 12.0.0 1557config CC_HAVE_SHADOW_CALL_STACK 1558 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1559 1560config PARAVIRT 1561 bool "Enable paravirtualization code" 1562 help 1563 This changes the kernel so it can modify itself when it is run 1564 under a hypervisor, potentially improving performance significantly 1565 over full virtualization. 1566 1567config PARAVIRT_TIME_ACCOUNTING 1568 bool "Paravirtual steal time accounting" 1569 select PARAVIRT 1570 help 1571 Select this option to enable fine granularity task steal time 1572 accounting. Time spent executing other tasks in parallel with 1573 the current vCPU is discounted from the vCPU power. To account for 1574 that, there can be a small performance impact. 1575 1576 If in doubt, say N here. 1577 1578config ARCH_SUPPORTS_KEXEC 1579 def_bool PM_SLEEP_SMP 1580 1581config ARCH_SUPPORTS_KEXEC_FILE 1582 def_bool y 1583 1584config ARCH_SELECTS_KEXEC_FILE 1585 def_bool y 1586 depends on KEXEC_FILE 1587 select HAVE_IMA_KEXEC if IMA 1588 1589config ARCH_SUPPORTS_KEXEC_SIG 1590 def_bool y 1591 1592config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1593 def_bool y 1594 1595config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1596 def_bool y 1597 1598config ARCH_SUPPORTS_KEXEC_HANDOVER 1599 def_bool y 1600 1601config ARCH_SUPPORTS_CRASH_DUMP 1602 def_bool y 1603 1604config ARCH_DEFAULT_CRASH_DUMP 1605 def_bool y 1606 1607config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1608 def_bool CRASH_RESERVE 1609 1610config TRANS_TABLE 1611 def_bool y 1612 depends on HIBERNATION || KEXEC_CORE 1613 1614config XEN_DOM0 1615 def_bool y 1616 depends on XEN 1617 1618config XEN 1619 bool "Xen guest support on ARM64" 1620 depends on ARM64 && OF 1621 select SWIOTLB_XEN 1622 select PARAVIRT 1623 help 1624 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1625 1626# include/linux/mmzone.h requires the following to be true: 1627# 1628# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1629# 1630# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1631# 1632# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1633# ----+-------------------+--------------+----------------------+-------------------------+ 1634# 4K | 27 | 12 | 15 | 10 | 1635# 16K | 27 | 14 | 13 | 11 | 1636# 64K | 29 | 16 | 13 | 13 | 1637config ARCH_FORCE_MAX_ORDER 1638 int 1639 default "13" if ARM64_64K_PAGES 1640 default "11" if ARM64_16K_PAGES 1641 default "10" 1642 help 1643 The kernel page allocator limits the size of maximal physically 1644 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1645 defines the maximal power of two of number of pages that can be 1646 allocated as a single contiguous block. This option allows 1647 overriding the default setting when ability to allocate very 1648 large blocks of physically contiguous memory is required. 1649 1650 The maximal size of allocation cannot exceed the size of the 1651 section, so the value of MAX_PAGE_ORDER should satisfy 1652 1653 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1654 1655 Don't change if unsure. 1656 1657config UNMAP_KERNEL_AT_EL0 1658 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1659 default y 1660 help 1661 Speculation attacks against some high-performance processors can 1662 be used to bypass MMU permission checks and leak kernel data to 1663 userspace. This can be defended against by unmapping the kernel 1664 when running in userspace, mapping it back in on exception entry 1665 via a trampoline page in the vector table. 1666 1667 If unsure, say Y. 1668 1669config MITIGATE_SPECTRE_BRANCH_HISTORY 1670 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1671 default y 1672 help 1673 Speculation attacks against some high-performance processors can 1674 make use of branch history to influence future speculation. 1675 When taking an exception from user-space, a sequence of branches 1676 or a firmware call overwrites the branch history. 1677 1678config ARM64_SW_TTBR0_PAN 1679 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1680 depends on !KCSAN 1681 select ARM64_PAN 1682 help 1683 Enabling this option prevents the kernel from accessing 1684 user-space memory directly by pointing TTBR0_EL1 to a reserved 1685 zeroed area and reserved ASID. The user access routines 1686 restore the valid TTBR0_EL1 temporarily. 1687 1688config ARM64_TAGGED_ADDR_ABI 1689 bool "Enable the tagged user addresses syscall ABI" 1690 default y 1691 help 1692 When this option is enabled, user applications can opt in to a 1693 relaxed ABI via prctl() allowing tagged addresses to be passed 1694 to system calls as pointer arguments. For details, see 1695 Documentation/arch/arm64/tagged-address-abi.rst. 1696 1697menuconfig COMPAT 1698 bool "Kernel support for 32-bit EL0" 1699 depends on ARM64_4K_PAGES || EXPERT 1700 select HAVE_UID16 1701 select OLD_SIGSUSPEND3 1702 select COMPAT_OLD_SIGACTION 1703 help 1704 This option enables support for a 32-bit EL0 running under a 64-bit 1705 kernel at EL1. AArch32-specific components such as system calls, 1706 the user helper functions, VFP support and the ptrace interface are 1707 handled appropriately by the kernel. 1708 1709 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1710 that you will only be able to execute AArch32 binaries that were compiled 1711 with page size aligned segments. 1712 1713 If you want to execute 32-bit userspace applications, say Y. 1714 1715if COMPAT 1716 1717config KUSER_HELPERS 1718 bool "Enable kuser helpers page for 32-bit applications" 1719 default y 1720 help 1721 Warning: disabling this option may break 32-bit user programs. 1722 1723 Provide kuser helpers to compat tasks. The kernel provides 1724 helper code to userspace in read only form at a fixed location 1725 to allow userspace to be independent of the CPU type fitted to 1726 the system. This permits binaries to be run on ARMv4 through 1727 to ARMv8 without modification. 1728 1729 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1730 1731 However, the fixed address nature of these helpers can be used 1732 by ROP (return orientated programming) authors when creating 1733 exploits. 1734 1735 If all of the binaries and libraries which run on your platform 1736 are built specifically for your platform, and make no use of 1737 these helpers, then you can turn this option off to hinder 1738 such exploits. However, in that case, if a binary or library 1739 relying on those helpers is run, it will not function correctly. 1740 1741 Say N here only if you are absolutely certain that you do not 1742 need these helpers; otherwise, the safe option is to say Y. 1743 1744config COMPAT_VDSO 1745 bool "Enable vDSO for 32-bit applications" 1746 depends on !CPU_BIG_ENDIAN 1747 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1748 default y 1749 help 1750 Place in the process address space of 32-bit applications an 1751 ELF shared object providing fast implementations of gettimeofday 1752 and clock_gettime. 1753 1754 You must have a 32-bit build of glibc 2.22 or later for programs 1755 to seamlessly take advantage of this. 1756 1757config THUMB2_COMPAT_VDSO 1758 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1759 depends on COMPAT_VDSO 1760 default y 1761 help 1762 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1763 otherwise with '-marm'. 1764 1765config COMPAT_ALIGNMENT_FIXUPS 1766 bool "Fix up misaligned multi-word loads and stores in user space" 1767 1768menuconfig ARMV8_DEPRECATED 1769 bool "Emulate deprecated/obsolete ARMv8 instructions" 1770 depends on SYSCTL 1771 help 1772 Legacy software support may require certain instructions 1773 that have been deprecated or obsoleted in the architecture. 1774 1775 Enable this config to enable selective emulation of these 1776 features. 1777 1778 If unsure, say Y 1779 1780if ARMV8_DEPRECATED 1781 1782config SWP_EMULATION 1783 bool "Emulate SWP/SWPB instructions" 1784 help 1785 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1786 they are always undefined. Say Y here to enable software 1787 emulation of these instructions for userspace using LDXR/STXR. 1788 This feature can be controlled at runtime with the abi.swp 1789 sysctl which is disabled by default. 1790 1791 In some older versions of glibc [<=2.8] SWP is used during futex 1792 trylock() operations with the assumption that the code will not 1793 be preempted. This invalid assumption may be more likely to fail 1794 with SWP emulation enabled, leading to deadlock of the user 1795 application. 1796 1797 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1798 on an external transaction monitoring block called a global 1799 monitor to maintain update atomicity. If your system does not 1800 implement a global monitor, this option can cause programs that 1801 perform SWP operations to uncached memory to deadlock. 1802 1803 If unsure, say Y 1804 1805config CP15_BARRIER_EMULATION 1806 bool "Emulate CP15 Barrier instructions" 1807 help 1808 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1809 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1810 strongly recommended to use the ISB, DSB, and DMB 1811 instructions instead. 1812 1813 Say Y here to enable software emulation of these 1814 instructions for AArch32 userspace code. When this option is 1815 enabled, CP15 barrier usage is traced which can help 1816 identify software that needs updating. This feature can be 1817 controlled at runtime with the abi.cp15_barrier sysctl. 1818 1819 If unsure, say Y 1820 1821config SETEND_EMULATION 1822 bool "Emulate SETEND instruction" 1823 help 1824 The SETEND instruction alters the data-endianness of the 1825 AArch32 EL0, and is deprecated in ARMv8. 1826 1827 Say Y here to enable software emulation of the instruction 1828 for AArch32 userspace code. This feature can be controlled 1829 at runtime with the abi.setend sysctl. 1830 1831 Note: All the cpus on the system must have mixed endian support at EL0 1832 for this feature to be enabled. If a new CPU - which doesn't support mixed 1833 endian - is hotplugged in after this feature has been enabled, there could 1834 be unexpected results in the applications. 1835 1836 If unsure, say Y 1837endif # ARMV8_DEPRECATED 1838 1839endif # COMPAT 1840 1841menu "ARMv8.1 architectural features" 1842 1843config ARM64_HW_AFDBM 1844 bool "Support for hardware updates of the Access and Dirty page flags" 1845 default y 1846 help 1847 The ARMv8.1 architecture extensions introduce support for 1848 hardware updates of the access and dirty information in page 1849 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1850 capable processors, accesses to pages with PTE_AF cleared will 1851 set this bit instead of raising an access flag fault. 1852 Similarly, writes to read-only pages with the DBM bit set will 1853 clear the read-only bit (AP[2]) instead of raising a 1854 permission fault. 1855 1856 Kernels built with this configuration option enabled continue 1857 to work on pre-ARMv8.1 hardware and the performance impact is 1858 minimal. If unsure, say Y. 1859 1860config ARM64_PAN 1861 bool "Enable support for Privileged Access Never (PAN)" 1862 default y 1863 help 1864 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1865 prevents the kernel or hypervisor from accessing user-space (EL0) 1866 memory directly. 1867 1868 Choosing this option will cause any unprotected (not using 1869 copy_to_user et al) memory access to fail with a permission fault. 1870 1871 The feature is detected at runtime, and will remain as a 'nop' 1872 instruction if the cpu does not implement the feature. 1873 1874config ARM64_LSE_ATOMICS 1875 bool 1876 default ARM64_USE_LSE_ATOMICS 1877 1878config ARM64_USE_LSE_ATOMICS 1879 bool "Atomic instructions" 1880 default y 1881 help 1882 As part of the Large System Extensions, ARMv8.1 introduces new 1883 atomic instructions that are designed specifically to scale in 1884 very large systems. 1885 1886 Say Y here to make use of these instructions for the in-kernel 1887 atomic routines. This incurs a small overhead on CPUs that do 1888 not support these instructions. 1889 1890endmenu # "ARMv8.1 architectural features" 1891 1892menu "ARMv8.2 architectural features" 1893 1894config ARM64_PMEM 1895 bool "Enable support for persistent memory" 1896 select ARCH_HAS_PMEM_API 1897 select ARCH_HAS_UACCESS_FLUSHCACHE 1898 help 1899 Say Y to enable support for the persistent memory API based on the 1900 ARMv8.2 DCPoP feature. 1901 1902 The feature is detected at runtime, and the kernel will use DC CVAC 1903 operations if DC CVAP is not supported (following the behaviour of 1904 DC CVAP itself if the system does not define a point of persistence). 1905 1906config ARM64_RAS_EXTN 1907 bool "Enable support for RAS CPU Extensions" 1908 default y 1909 help 1910 CPUs that support the Reliability, Availability and Serviceability 1911 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1912 errors, classify them and report them to software. 1913 1914 On CPUs with these extensions system software can use additional 1915 barriers to determine if faults are pending and read the 1916 classification from a new set of registers. 1917 1918 Selecting this feature will allow the kernel to use these barriers 1919 and access the new registers if the system supports the extension. 1920 Platform RAS features may additionally depend on firmware support. 1921 1922config ARM64_CNP 1923 bool "Enable support for Common Not Private (CNP) translations" 1924 default y 1925 help 1926 Common Not Private (CNP) allows translation table entries to 1927 be shared between different PEs in the same inner shareable 1928 domain, so the hardware can use this fact to optimise the 1929 caching of such entries in the TLB. 1930 1931 Selecting this option allows the CNP feature to be detected 1932 at runtime, and does not affect PEs that do not implement 1933 this feature. 1934 1935endmenu # "ARMv8.2 architectural features" 1936 1937menu "ARMv8.3 architectural features" 1938 1939config ARM64_PTR_AUTH 1940 bool "Enable support for pointer authentication" 1941 default y 1942 help 1943 Pointer authentication (part of the ARMv8.3 Extensions) provides 1944 instructions for signing and authenticating pointers against secret 1945 keys, which can be used to mitigate Return Oriented Programming (ROP) 1946 and other attacks. 1947 1948 This option enables these instructions at EL0 (i.e. for userspace). 1949 Choosing this option will cause the kernel to initialise secret keys 1950 for each process at exec() time, with these keys being 1951 context-switched along with the process. 1952 1953 The feature is detected at runtime. If the feature is not present in 1954 hardware it will not be advertised to userspace/KVM guest nor will it 1955 be enabled. 1956 1957 If the feature is present on the boot CPU but not on a late CPU, then 1958 the late CPU will be parked. Also, if the boot CPU does not have 1959 address auth and the late CPU has then the late CPU will still boot 1960 but with the feature disabled. On such a system, this option should 1961 not be selected. 1962 1963config ARM64_PTR_AUTH_KERNEL 1964 bool "Use pointer authentication for kernel" 1965 default y 1966 depends on ARM64_PTR_AUTH 1967 # Modern compilers insert a .note.gnu.property section note for PAC 1968 # which is only understood by binutils starting with version 2.33.1. 1969 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1970 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1971 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1972 help 1973 If the compiler supports the -mbranch-protection or 1974 -msign-return-address flag (e.g. GCC 7 or later), then this option 1975 will cause the kernel itself to be compiled with return address 1976 protection. In this case, and if the target hardware is known to 1977 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1978 disabled with minimal loss of protection. 1979 1980 This feature works with FUNCTION_GRAPH_TRACER option only if 1981 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1982 1983config CC_HAS_BRANCH_PROT_PAC_RET 1984 # GCC 9 or later, clang 8 or later 1985 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1986 1987config AS_HAS_CFI_NEGATE_RA_STATE 1988 # binutils 2.34+ 1989 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1990 1991endmenu # "ARMv8.3 architectural features" 1992 1993menu "ARMv8.4 architectural features" 1994 1995config ARM64_AMU_EXTN 1996 bool "Enable support for the Activity Monitors Unit CPU extension" 1997 default y 1998 help 1999 The activity monitors extension is an optional extension introduced 2000 by the ARMv8.4 CPU architecture. This enables support for version 1 2001 of the activity monitors architecture, AMUv1. 2002 2003 To enable the use of this extension on CPUs that implement it, say Y. 2004 2005 Note that for architectural reasons, firmware _must_ implement AMU 2006 support when running on CPUs that present the activity monitors 2007 extension. The required support is present in: 2008 * Version 1.5 and later of the ARM Trusted Firmware 2009 2010 For kernels that have this configuration enabled but boot with broken 2011 firmware, you may need to say N here until the firmware is fixed. 2012 Otherwise you may experience firmware panics or lockups when 2013 accessing the counter registers. Even if you are not observing these 2014 symptoms, the values returned by the register reads might not 2015 correctly reflect reality. Most commonly, the value read will be 0, 2016 indicating that the counter is not enabled. 2017 2018config ARM64_TLB_RANGE 2019 bool "Enable support for tlbi range feature" 2020 default y 2021 help 2022 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2023 range of input addresses. 2024 2025config ARM64_MPAM 2026 bool "Enable support for MPAM" 2027 select ARM64_MPAM_DRIVER if EXPERT # does nothing yet 2028 select ACPI_MPAM if ACPI 2029 help 2030 Memory System Resource Partitioning and Monitoring (MPAM) is an 2031 optional extension to the Arm architecture that allows each 2032 transaction issued to the memory system to be labelled with a 2033 Partition identifier (PARTID) and Performance Monitoring Group 2034 identifier (PMG). 2035 2036 Memory system components, such as the caches, can be configured with 2037 policies to control how much of various physical resources (such as 2038 memory bandwidth or cache memory) the transactions labelled with each 2039 PARTID can consume. Depending on the capabilities of the hardware, 2040 the PARTID and PMG can also be used as filtering criteria to measure 2041 the memory system resource consumption of different parts of a 2042 workload. 2043 2044 Use of this extension requires CPU support, support in the 2045 Memory System Components (MSC), and a description from firmware 2046 of where the MSCs are in the address space. 2047 2048 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2049 2050endmenu # "ARMv8.4 architectural features" 2051 2052menu "ARMv8.5 architectural features" 2053 2054config AS_HAS_ARMV8_5 2055 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2056 2057config ARM64_BTI 2058 bool "Branch Target Identification support" 2059 default y 2060 help 2061 Branch Target Identification (part of the ARMv8.5 Extensions) 2062 provides a mechanism to limit the set of locations to which computed 2063 branch instructions such as BR or BLR can jump. 2064 2065 To make use of BTI on CPUs that support it, say Y. 2066 2067 BTI is intended to provide complementary protection to other control 2068 flow integrity protection mechanisms, such as the Pointer 2069 authentication mechanism provided as part of the ARMv8.3 Extensions. 2070 For this reason, it does not make sense to enable this option without 2071 also enabling support for pointer authentication. Thus, when 2072 enabling this option you should also select ARM64_PTR_AUTH=y. 2073 2074 Userspace binaries must also be specifically compiled to make use of 2075 this mechanism. If you say N here or the hardware does not support 2076 BTI, such binaries can still run, but you get no additional 2077 enforcement of branch destinations. 2078 2079config ARM64_BTI_KERNEL 2080 bool "Use Branch Target Identification for kernel" 2081 default y 2082 depends on ARM64_BTI 2083 depends on ARM64_PTR_AUTH_KERNEL 2084 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2085 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2086 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2087 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2088 depends on !CC_IS_GCC 2089 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2090 help 2091 Build the kernel with Branch Target Identification annotations 2092 and enable enforcement of this for kernel code. When this option 2093 is enabled and the system supports BTI all kernel code including 2094 modular code must have BTI enabled. 2095 2096config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2097 # GCC 9 or later, clang 8 or later 2098 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2099 2100config ARM64_E0PD 2101 bool "Enable support for E0PD" 2102 default y 2103 help 2104 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2105 that EL0 accesses made via TTBR1 always fault in constant time, 2106 providing similar benefits to KASLR as those provided by KPTI, but 2107 with lower overhead and without disrupting legitimate access to 2108 kernel memory such as SPE. 2109 2110 This option enables E0PD for TTBR1 where available. 2111 2112config ARM64_AS_HAS_MTE 2113 # Initial support for MTE went in binutils 2.32.0, checked with 2114 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2115 # as a late addition to the final architecture spec (LDGM/STGM) 2116 # is only supported in the newer 2.32.x and 2.33 binutils 2117 # versions, hence the extra "stgm" instruction check below. 2118 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2119 2120config ARM64_MTE 2121 bool "Memory Tagging Extension support" 2122 default y 2123 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2124 depends on AS_HAS_ARMV8_5 2125 # Required for tag checking in the uaccess routines 2126 select ARM64_PAN 2127 select ARCH_HAS_SUBPAGE_FAULTS 2128 select ARCH_USES_HIGH_VMA_FLAGS 2129 select ARCH_USES_PG_ARCH_2 2130 select ARCH_USES_PG_ARCH_3 2131 help 2132 Memory Tagging (part of the ARMv8.5 Extensions) provides 2133 architectural support for run-time, always-on detection of 2134 various classes of memory error to aid with software debugging 2135 to eliminate vulnerabilities arising from memory-unsafe 2136 languages. 2137 2138 This option enables the support for the Memory Tagging 2139 Extension at EL0 (i.e. for userspace). 2140 2141 Selecting this option allows the feature to be detected at 2142 runtime. Any secondary CPU not implementing this feature will 2143 not be allowed a late bring-up. 2144 2145 Userspace binaries that want to use this feature must 2146 explicitly opt in. The mechanism for the userspace is 2147 described in: 2148 2149 Documentation/arch/arm64/memory-tagging-extension.rst. 2150 2151endmenu # "ARMv8.5 architectural features" 2152 2153menu "ARMv8.7 architectural features" 2154 2155config ARM64_EPAN 2156 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2157 default y 2158 depends on ARM64_PAN 2159 help 2160 Enhanced Privileged Access Never (EPAN) allows Privileged 2161 Access Never to be used with Execute-only mappings. 2162 2163 The feature is detected at runtime, and will remain disabled 2164 if the cpu does not implement the feature. 2165endmenu # "ARMv8.7 architectural features" 2166 2167config AS_HAS_MOPS 2168 def_bool $(as-instr,.arch_extension mops) 2169 2170menu "ARMv8.9 architectural features" 2171 2172config ARM64_POE 2173 prompt "Permission Overlay Extension" 2174 def_bool y 2175 select ARCH_USES_HIGH_VMA_FLAGS 2176 select ARCH_HAS_PKEYS 2177 help 2178 The Permission Overlay Extension is used to implement Memory 2179 Protection Keys. Memory Protection Keys provides a mechanism for 2180 enforcing page-based protections, but without requiring modification 2181 of the page tables when an application changes protection domains. 2182 2183 For details, see Documentation/core-api/protection-keys.rst 2184 2185 If unsure, say y. 2186 2187config ARCH_PKEY_BITS 2188 int 2189 default 3 2190 2191config ARM64_HAFT 2192 bool "Support for Hardware managed Access Flag for Table Descriptors" 2193 depends on ARM64_HW_AFDBM 2194 default y 2195 help 2196 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2197 Flag for Table descriptors. When enabled an architectural executed 2198 memory access will update the Access Flag in each Table descriptor 2199 which is accessed during the translation table walk and for which 2200 the Access Flag is 0. The Access Flag of the Table descriptor use 2201 the same bit of PTE_AF. 2202 2203 The feature will only be enabled if all the CPUs in the system 2204 support this feature. If unsure, say Y. 2205 2206endmenu # "ARMv8.9 architectural features" 2207 2208menu "ARMv9.4 architectural features" 2209 2210config ARM64_GCS 2211 bool "Enable support for Guarded Control Stack (GCS)" 2212 default y 2213 select ARCH_HAS_USER_SHADOW_STACK 2214 select ARCH_USES_HIGH_VMA_FLAGS 2215 help 2216 Guarded Control Stack (GCS) provides support for a separate 2217 stack with restricted access which contains only return 2218 addresses. This can be used to harden against some attacks 2219 by comparing return address used by the program with what is 2220 stored in the GCS, and may also be used to efficiently obtain 2221 the call stack for applications such as profiling. 2222 2223 The feature is detected at runtime, and will remain disabled 2224 if the system does not implement the feature. 2225 2226endmenu # "ARMv9.4 architectural features" 2227 2228config ARM64_SVE 2229 bool "ARM Scalable Vector Extension support" 2230 default y 2231 help 2232 The Scalable Vector Extension (SVE) is an extension to the AArch64 2233 execution state which complements and extends the SIMD functionality 2234 of the base architecture to support much larger vectors and to enable 2235 additional vectorisation opportunities. 2236 2237 To enable use of this extension on CPUs that implement it, say Y. 2238 2239 On CPUs that support the SVE2 extensions, this option will enable 2240 those too. 2241 2242 Note that for architectural reasons, firmware _must_ implement SVE 2243 support when running on SVE capable hardware. The required support 2244 is present in: 2245 2246 * version 1.5 and later of the ARM Trusted Firmware 2247 * the AArch64 boot wrapper since commit 5e1261e08abf 2248 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2249 2250 For other firmware implementations, consult the firmware documentation 2251 or vendor. 2252 2253 If you need the kernel to boot on SVE-capable hardware with broken 2254 firmware, you may need to say N here until you get your firmware 2255 fixed. Otherwise, you may experience firmware panics or lockups when 2256 booting the kernel. If unsure and you are not observing these 2257 symptoms, you should assume that it is safe to say Y. 2258 2259config ARM64_SME 2260 bool "ARM Scalable Matrix Extension support" 2261 default y 2262 depends on ARM64_SVE 2263 help 2264 The Scalable Matrix Extension (SME) is an extension to the AArch64 2265 execution state which utilises a substantial subset of the SVE 2266 instruction set, together with the addition of new architectural 2267 register state capable of holding two dimensional matrix tiles to 2268 enable various matrix operations. 2269 2270config ARM64_PSEUDO_NMI 2271 bool "Support for NMI-like interrupts" 2272 select ARM_GIC_V3 2273 help 2274 Adds support for mimicking Non-Maskable Interrupts through the use of 2275 GIC interrupt priority. This support requires version 3 or later of 2276 ARM GIC. 2277 2278 This high priority configuration for interrupts needs to be 2279 explicitly enabled by setting the kernel parameter 2280 "irqchip.gicv3_pseudo_nmi" to 1. 2281 2282 If unsure, say N 2283 2284if ARM64_PSEUDO_NMI 2285config ARM64_DEBUG_PRIORITY_MASKING 2286 bool "Debug interrupt priority masking" 2287 help 2288 This adds runtime checks to functions enabling/disabling 2289 interrupts when using priority masking. The additional checks verify 2290 the validity of ICC_PMR_EL1 when calling concerned functions. 2291 2292 If unsure, say N 2293endif # ARM64_PSEUDO_NMI 2294 2295config RELOCATABLE 2296 bool "Build a relocatable kernel image" if EXPERT 2297 select ARCH_HAS_RELR 2298 default y 2299 help 2300 This builds the kernel as a Position Independent Executable (PIE), 2301 which retains all relocation metadata required to relocate the 2302 kernel binary at runtime to a different virtual address than the 2303 address it was linked at. 2304 Since AArch64 uses the RELA relocation format, this requires a 2305 relocation pass at runtime even if the kernel is loaded at the 2306 same address it was linked at. 2307 2308config RANDOMIZE_BASE 2309 bool "Randomize the address of the kernel image" 2310 select RELOCATABLE 2311 help 2312 Randomizes the virtual address at which the kernel image is 2313 loaded, as a security feature that deters exploit attempts 2314 relying on knowledge of the location of kernel internals. 2315 2316 It is the bootloader's job to provide entropy, by passing a 2317 random u64 value in /chosen/kaslr-seed at kernel entry. 2318 2319 When booting via the UEFI stub, it will invoke the firmware's 2320 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2321 to the kernel proper. In addition, it will randomise the physical 2322 location of the kernel Image as well. 2323 2324 If unsure, say N. 2325 2326config RANDOMIZE_MODULE_REGION_FULL 2327 bool "Randomize the module region over a 2 GB range" 2328 depends on RANDOMIZE_BASE 2329 default y 2330 help 2331 Randomizes the location of the module region inside a 2 GB window 2332 covering the core kernel. This way, it is less likely for modules 2333 to leak information about the location of core kernel data structures 2334 but it does imply that function calls between modules and the core 2335 kernel will need to be resolved via veneers in the module PLT. 2336 2337 When this option is not set, the module region will be randomized over 2338 a limited range that contains the [_stext, _etext] interval of the 2339 core kernel, so branch relocations are almost always in range unless 2340 the region is exhausted. In this particular case of region 2341 exhaustion, modules might be able to fall back to a larger 2GB area. 2342 2343config CC_HAVE_STACKPROTECTOR_SYSREG 2344 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2345 2346config STACKPROTECTOR_PER_TASK 2347 def_bool y 2348 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2349 2350config UNWIND_PATCH_PAC_INTO_SCS 2351 bool "Enable shadow call stack dynamically using code patching" 2352 depends on CC_IS_CLANG 2353 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2354 depends on SHADOW_CALL_STACK 2355 select UNWIND_TABLES 2356 select DYNAMIC_SCS 2357 2358config ARM64_CONTPTE 2359 bool "Contiguous PTE mappings for user memory" if EXPERT 2360 depends on TRANSPARENT_HUGEPAGE 2361 default y 2362 help 2363 When enabled, user mappings are configured using the PTE contiguous 2364 bit, for any mappings that meet the size and alignment requirements. 2365 This reduces TLB pressure and improves performance. 2366 2367endmenu # "Kernel Features" 2368 2369menu "Boot options" 2370 2371config ARM64_ACPI_PARKING_PROTOCOL 2372 bool "Enable support for the ARM64 ACPI parking protocol" 2373 depends on ACPI 2374 help 2375 Enable support for the ARM64 ACPI parking protocol. If disabled 2376 the kernel will not allow booting through the ARM64 ACPI parking 2377 protocol even if the corresponding data is present in the ACPI 2378 MADT table. 2379 2380config CMDLINE 2381 string "Default kernel command string" 2382 default "" 2383 help 2384 Provide a set of default command-line options at build time by 2385 entering them here. As a minimum, you should specify the the 2386 root device (e.g. root=/dev/nfs). 2387 2388choice 2389 prompt "Kernel command line type" 2390 depends on CMDLINE != "" 2391 default CMDLINE_FROM_BOOTLOADER 2392 help 2393 Choose how the kernel will handle the provided default kernel 2394 command line string. 2395 2396config CMDLINE_FROM_BOOTLOADER 2397 bool "Use bootloader kernel arguments if available" 2398 help 2399 Uses the command-line options passed by the boot loader. If 2400 the boot loader doesn't provide any, the default kernel command 2401 string provided in CMDLINE will be used. 2402 2403config CMDLINE_FORCE 2404 bool "Always use the default kernel command string" 2405 help 2406 Always use the default kernel command string, even if the boot 2407 loader passes other arguments to the kernel. 2408 This is useful if you cannot or don't want to change the 2409 command-line options your boot loader passes to the kernel. 2410 2411endchoice 2412 2413config EFI_STUB 2414 bool 2415 2416config EFI 2417 bool "UEFI runtime support" 2418 depends on OF && !CPU_BIG_ENDIAN 2419 depends on KERNEL_MODE_NEON 2420 select ARCH_SUPPORTS_ACPI 2421 select LIBFDT 2422 select UCS2_STRING 2423 select EFI_PARAMS_FROM_FDT 2424 select EFI_RUNTIME_WRAPPERS 2425 select EFI_STUB 2426 select EFI_GENERIC_STUB 2427 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2428 default y 2429 help 2430 This option provides support for runtime services provided 2431 by UEFI firmware (such as non-volatile variables, realtime 2432 clock, and platform reset). A UEFI stub is also provided to 2433 allow the kernel to be booted as an EFI application. This 2434 is only useful on systems that have UEFI firmware. 2435 2436config COMPRESSED_INSTALL 2437 bool "Install compressed image by default" 2438 help 2439 This makes the regular "make install" install the compressed 2440 image we built, not the legacy uncompressed one. 2441 2442 You can check that a compressed image works for you by doing 2443 "make zinstall" first, and verifying that everything is fine 2444 in your environment before making "make install" do this for 2445 you. 2446 2447config DMI 2448 bool "Enable support for SMBIOS (DMI) tables" 2449 depends on EFI 2450 default y 2451 help 2452 This enables SMBIOS/DMI feature for systems. 2453 2454 This option is only useful on systems that have UEFI firmware. 2455 However, even with this option, the resultant kernel should 2456 continue to boot on existing non-UEFI platforms. 2457 2458endmenu # "Boot options" 2459 2460menu "Power management options" 2461 2462source "kernel/power/Kconfig" 2463 2464config ARCH_HIBERNATION_POSSIBLE 2465 def_bool y 2466 depends on CPU_PM 2467 2468config ARCH_HIBERNATION_HEADER 2469 def_bool y 2470 depends on HIBERNATION 2471 2472config ARCH_SUSPEND_POSSIBLE 2473 def_bool y 2474 2475endmenu # "Power management options" 2476 2477menu "CPU Power Management" 2478 2479source "drivers/cpuidle/Kconfig" 2480 2481source "drivers/cpufreq/Kconfig" 2482 2483endmenu # "CPU Power Management" 2484 2485source "drivers/acpi/Kconfig" 2486 2487source "arch/arm64/kvm/Kconfig" 2488 2489source "kernel/livepatch/Kconfig" 2490