1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 25 select ARCH_HAS_CURRENT_STACK_POINTER 26 select ARCH_HAS_DEBUG_VIRTUAL 27 select ARCH_HAS_DEBUG_VM_PGTABLE 28 select ARCH_HAS_DMA_OPS if XEN 29 select ARCH_HAS_DMA_PREP_COHERENT 30 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_KCOV 36 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 37 select ARCH_HAS_KEEPINITRD 38 select ARCH_HAS_LAZY_MMU_MODE 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MEM_ENCRYPT 41 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 42 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 45 select ARCH_HAS_PREEMPT_LAZY 46 select ARCH_HAS_PTDUMP 47 select ARCH_HAS_PTE_SPECIAL 48 select ARCH_HAS_HW_PTE_YOUNG 49 select ARCH_HAS_SETUP_DMA_OPS 50 select ARCH_HAS_SET_DIRECT_MAP 51 select ARCH_HAS_SET_MEMORY 52 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 53 select ARCH_STACKWALK 54 select ARCH_HAS_STRICT_KERNEL_RWX 55 select ARCH_HAS_STRICT_MODULE_RWX 56 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 57 select ARCH_HAS_SYNC_DMA_FOR_CPU 58 select ARCH_HAS_SYSCALL_WRAPPER 59 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 60 select ARCH_HAS_ZONE_DMA_SET if EXPERT 61 select ARCH_HAVE_ELF_PROT 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_HAVE_TRACE_MMIO_ACCESS 64 select ARCH_INLINE_READ_LOCK if !PREEMPTION 65 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 66 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 67 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 68 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 69 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 70 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 71 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 72 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 73 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 74 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 75 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 76 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 77 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 78 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 79 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 80 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 81 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 82 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 83 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 84 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 85 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 86 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 87 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 88 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 89 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 90 select ARCH_KEEP_MEMBLOCK 91 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 92 select ARCH_USE_CMPXCHG_LOCKREF 93 select ARCH_USE_GNU_PROPERTY 94 select ARCH_USE_MEMTEST 95 select ARCH_USE_QUEUED_RWLOCKS 96 select ARCH_USE_QUEUED_SPINLOCKS 97 select ARCH_USE_SYM_ANNOTATIONS 98 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 99 select ARCH_SUPPORTS_HUGETLBFS 100 select ARCH_SUPPORTS_MEMORY_FAILURE 101 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 102 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 103 select ARCH_SUPPORTS_LTO_CLANG_THIN 104 select ARCH_SUPPORTS_CFI 105 select ARCH_SUPPORTS_ATOMIC_RMW 106 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 107 select ARCH_SUPPORTS_NUMA_BALANCING 108 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 109 select ARCH_SUPPORTS_PER_VMA_LOCK 110 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 111 select ARCH_SUPPORTS_RT 112 select ARCH_SUPPORTS_SCHED_SMT 113 select ARCH_SUPPORTS_SCHED_CLUSTER 114 select ARCH_SUPPORTS_SCHED_MC 115 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 116 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 117 select ARCH_WANT_DEFAULT_BPF_JIT 118 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 119 select ARCH_WANT_FRAME_POINTERS 120 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 121 select ARCH_WANT_LD_ORPHAN_WARN 122 select ARCH_WANTS_EXECMEM_LATE 123 select ARCH_WANTS_NO_INSTR 124 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 125 select ARCH_HAS_UBSAN 126 select ARM_AMBA 127 select ARM_ARCH_TIMER 128 select ARM_GIC 129 select AUDIT_ARCH_COMPAT_GENERIC 130 select ARM_GIC_V2M if PCI 131 select ARM_GIC_V3 132 select ARM_GIC_V3_ITS if PCI 133 select ARM_GIC_V5 134 select ARM_PSCI_FW 135 select BUILDTIME_TABLE_SORT 136 select CLONE_BACKWARDS 137 select COMMON_CLK 138 select CPU_PM if (SUSPEND || CPU_IDLE) 139 select CPUMASK_OFFSTACK if NR_CPUS > 256 140 select DCACHE_WORD_ACCESS 141 select HAVE_EXTRA_IPI_TRACEPOINTS 142 select DYNAMIC_FTRACE if FUNCTION_TRACER 143 select DMA_BOUNCE_UNALIGNED_KMALLOC 144 select DMA_DIRECT_REMAP 145 select EDAC_SUPPORT 146 select FRAME_POINTER 147 select FUNCTION_ALIGNMENT_4B 148 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 149 select GENERIC_ALLOCATOR 150 select GENERIC_ARCH_TOPOLOGY 151 select GENERIC_CLOCKEVENTS_BROADCAST 152 select GENERIC_CPU_AUTOPROBE 153 select GENERIC_CPU_CACHE_MAINTENANCE 154 select GENERIC_CPU_DEVICES 155 select GENERIC_CPU_VULNERABILITIES 156 select GENERIC_EARLY_IOREMAP 157 select GENERIC_IDLE_POLL_SETUP 158 select GENERIC_IOREMAP 159 select GENERIC_IRQ_ENTRY 160 select GENERIC_IRQ_IPI 161 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 162 select GENERIC_IRQ_PROBE 163 select GENERIC_IRQ_SHOW 164 select GENERIC_IRQ_SHOW_LEVEL 165 select GENERIC_LIB_DEVMEM_IS_ALLOWED 166 select GENERIC_PCI_IOMAP 167 select GENERIC_SCHED_CLOCK 168 select GENERIC_SMP_IDLE_THREAD 169 select GENERIC_TIME_VSYSCALL 170 select GENERIC_GETTIMEOFDAY 171 select HARDIRQS_SW_RESEND 172 select HAS_IOPORT 173 select HAVE_MOVE_PMD 174 select HAVE_MOVE_PUD 175 select HAVE_PCI 176 select HAVE_ACPI_APEI if (ACPI && EFI) 177 select HAVE_ALIGNED_STRUCT_PAGE 178 select HAVE_ARCH_AUDITSYSCALL 179 select HAVE_ARCH_BITREVERSE 180 select HAVE_ARCH_COMPILER_H 181 select HAVE_ARCH_HUGE_VMALLOC 182 select HAVE_ARCH_HUGE_VMAP 183 select HAVE_ARCH_JUMP_LABEL 184 select HAVE_ARCH_JUMP_LABEL_RELATIVE 185 select HAVE_ARCH_KASAN 186 select HAVE_ARCH_KASAN_VMALLOC 187 select HAVE_ARCH_KASAN_SW_TAGS 188 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 189 # Some instrumentation may be unsound, hence EXPERT 190 select HAVE_ARCH_KCSAN if EXPERT 191 select HAVE_ARCH_KFENCE 192 select HAVE_ARCH_KGDB 193 select HAVE_ARCH_KSTACK_ERASE 194 select HAVE_ARCH_MMAP_RND_BITS 195 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 196 select HAVE_ARCH_PREL32_RELOCATIONS 197 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 198 select HAVE_ARCH_SECCOMP_FILTER 199 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 200 select HAVE_ARCH_TRACEHOOK 201 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 202 select HAVE_ARCH_VMAP_STACK 203 select HAVE_ARM_SMCCC 204 select HAVE_ASM_MODVERSIONS 205 select HAVE_EBPF_JIT 206 select HAVE_C_RECORDMCOUNT 207 select HAVE_CMPXCHG_DOUBLE 208 select HAVE_CMPXCHG_LOCAL 209 select HAVE_CONTEXT_TRACKING_USER 210 select HAVE_DEBUG_KMEMLEAK 211 select HAVE_DMA_CONTIGUOUS 212 select HAVE_DYNAMIC_FTRACE 213 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 214 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 215 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 216 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 217 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 218 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 219 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ 220 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 221 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 222 if DYNAMIC_FTRACE_WITH_ARGS 223 select HAVE_SAMPLE_FTRACE_DIRECT 224 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 225 select HAVE_BUILDTIME_MCOUNT_SORT 226 select HAVE_EFFICIENT_UNALIGNED_ACCESS 227 select HAVE_GUP_FAST 228 select HAVE_FTRACE_GRAPH_FUNC 229 select HAVE_FUNCTION_TRACER 230 select HAVE_FUNCTION_ERROR_INJECTION 231 select HAVE_FUNCTION_GRAPH_FREGS 232 select HAVE_FUNCTION_GRAPH_TRACER 233 select HAVE_GCC_PLUGINS 234 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 235 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 236 select HAVE_HW_BREAKPOINT if PERF_EVENTS 237 select HAVE_IOREMAP_PROT 238 select HAVE_IRQ_TIME_ACCOUNTING 239 select HAVE_LIVEPATCH 240 select HAVE_MOD_ARCH_SPECIFIC 241 select HAVE_NMI 242 select HAVE_PERF_EVENTS 243 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 244 select HAVE_PERF_REGS 245 select HAVE_PERF_USER_STACK_DUMP 246 select HAVE_PREEMPT_DYNAMIC_KEY 247 select HAVE_REGS_AND_STACK_ACCESS_API 248 select HAVE_RELIABLE_STACKTRACE 249 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 250 select HAVE_FUNCTION_ARG_ACCESS_API 251 select MMU_GATHER_RCU_TABLE_FREE 252 select HAVE_RSEQ 253 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 254 select HAVE_STACKPROTECTOR 255 select HAVE_STATIC_CALL if CFI 256 select HAVE_SYSCALL_TRACEPOINTS 257 select HAVE_KPROBES 258 select HAVE_KRETPROBES 259 select HAVE_GENERIC_VDSO 260 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 261 select HOTPLUG_SMT if HOTPLUG_CPU 262 select IRQ_DOMAIN 263 select IRQ_FORCED_THREADING 264 select JUMP_LABEL 265 select KASAN_VMALLOC if KASAN 266 select LOCK_MM_AND_FIND_VMA 267 select MODULES_USE_ELF_RELA 268 select NEED_DMA_MAP_STATE 269 select NEED_SG_DMA_LENGTH 270 select OF 271 select OF_EARLY_FLATTREE 272 select PCI_DOMAINS_GENERIC if PCI 273 select PCI_ECAM if (ACPI && PCI) 274 select PCI_SYSCALL if PCI 275 select POWER_RESET 276 select POWER_SUPPLY 277 select SPARSE_IRQ 278 select SWIOTLB 279 select SYSCTL_EXCEPTION_TRACE 280 select THREAD_INFO_IN_TASK 281 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 282 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 283 select TRACE_IRQFLAGS_SUPPORT 284 select TRACE_IRQFLAGS_NMI_SUPPORT 285 select HAVE_SOFTIRQ_ON_OWN_STACK 286 select USER_STACKTRACE_SUPPORT 287 select VDSO_GETRANDOM 288 select VMAP_STACK 289 help 290 ARM 64-bit (AArch64) Linux support. 291 292config RUSTC_SUPPORTS_ARM64 293 def_bool y 294 depends on CPU_LITTLE_ENDIAN 295 # Shadow call stack is only supported on certain rustc versions. 296 # 297 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 298 # required due to use of the -Zfixed-x18 flag. 299 # 300 # Otherwise, rustc version 1.82+ is required due to use of the 301 # -Zsanitizer=shadow-call-stack flag. 302 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 303 304config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 305 def_bool CC_IS_CLANG 306 # https://github.com/ClangBuiltLinux/linux/issues/1507 307 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 308 309config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 310 def_bool CC_IS_GCC 311 depends on $(cc-option,-fpatchable-function-entry=2) 312 313config 64BIT 314 def_bool y 315 316config MMU 317 def_bool y 318 319config ARM64_CONT_PTE_SHIFT 320 int 321 default 5 if PAGE_SIZE_64KB 322 default 7 if PAGE_SIZE_16KB 323 default 4 324 325config ARM64_CONT_PMD_SHIFT 326 int 327 default 5 if PAGE_SIZE_64KB 328 default 5 if PAGE_SIZE_16KB 329 default 4 330 331config ARCH_MMAP_RND_BITS_MIN 332 default 14 if PAGE_SIZE_64KB 333 default 16 if PAGE_SIZE_16KB 334 default 18 335 336# max bits determined by the following formula: 337# VA_BITS - PTDESC_TABLE_SHIFT 338config ARCH_MMAP_RND_BITS_MAX 339 default 19 if ARM64_VA_BITS=36 340 default 24 if ARM64_VA_BITS=39 341 default 27 if ARM64_VA_BITS=42 342 default 30 if ARM64_VA_BITS=47 343 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 344 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 345 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 346 default 14 if ARM64_64K_PAGES 347 default 16 if ARM64_16K_PAGES 348 default 18 349 350config ARCH_MMAP_RND_COMPAT_BITS_MIN 351 default 7 if ARM64_64K_PAGES 352 default 9 if ARM64_16K_PAGES 353 default 11 354 355config ARCH_MMAP_RND_COMPAT_BITS_MAX 356 default 16 357 358config NO_IOPORT_MAP 359 def_bool y if !PCI 360 361config STACKTRACE_SUPPORT 362 def_bool y 363 364config ILLEGAL_POINTER_VALUE 365 hex 366 default 0xdead000000000000 367 368config LOCKDEP_SUPPORT 369 def_bool y 370 371config GENERIC_BUG 372 def_bool y 373 depends on BUG 374 375config GENERIC_BUG_RELATIVE_POINTERS 376 def_bool y 377 depends on GENERIC_BUG 378 379config GENERIC_HWEIGHT 380 def_bool y 381 382config GENERIC_CSUM 383 def_bool y 384 385config GENERIC_CALIBRATE_DELAY 386 def_bool y 387 388config SMP 389 def_bool y 390 391config KERNEL_MODE_NEON 392 def_bool y 393 394config FIX_EARLYCON_MEM 395 def_bool y 396 397config PGTABLE_LEVELS 398 int 399 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 400 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 401 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 402 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 403 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 404 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 405 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 406 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 407 408config ARCH_SUPPORTS_UPROBES 409 def_bool y 410 411config ARCH_PROC_KCORE_TEXT 412 def_bool y 413 414config BROKEN_GAS_INST 415 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 416 417config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 418 bool 419 # Clang's __builtin_return_address() strips the PAC since 12.0.0 420 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 421 default y if CC_IS_CLANG 422 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 423 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 424 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 425 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 426 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 427 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 428 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 429 default n 430 431config KASAN_SHADOW_OFFSET 432 hex 433 depends on KASAN_GENERIC || KASAN_SW_TAGS 434 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 435 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 436 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 437 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 438 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 439 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 440 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 441 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 442 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 443 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 444 default 0xffffffffffffffff 445 446config UNWIND_TABLES 447 bool 448 449source "arch/arm64/Kconfig.platforms" 450 451menu "Kernel Features" 452 453menu "ARM errata workarounds via the alternatives framework" 454 455config AMPERE_ERRATUM_AC03_CPU_38 456 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 457 default y 458 help 459 This option adds an alternative code sequence to work around Ampere 460 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 461 462 The affected design reports FEAT_HAFDBS as not implemented in 463 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 464 as required by the architecture. The unadvertised HAFDBS 465 implementation suffers from an additional erratum where hardware 466 A/D updates can occur after a PTE has been marked invalid. 467 468 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 469 which avoids enabling unadvertised hardware Access Flag management 470 at stage-2. 471 472 If unsure, say Y. 473 474config AMPERE_ERRATUM_AC04_CPU_23 475 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 476 default y 477 help 478 This option adds an alternative code sequence to work around Ampere 479 errata AC04_CPU_23 on AmpereOne. 480 481 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 482 data addresses initiated by load/store instructions. Only 483 instruction initiated translations are vulnerable, not translations 484 from prefetches for example. A DSB before the store to HCR_EL2 is 485 sufficient to prevent older instructions from hitting the window 486 for corruption, and an ISB after is sufficient to prevent younger 487 instructions from hitting the window for corruption. 488 489 If unsure, say Y. 490 491config ARM64_WORKAROUND_CLEAN_CACHE 492 bool 493 494config ARM64_ERRATUM_826319 495 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 496 default y 497 select ARM64_WORKAROUND_CLEAN_CACHE 498 help 499 This option adds an alternative code sequence to work around ARM 500 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 501 AXI master interface and an L2 cache. 502 503 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 504 and is unable to accept a certain write via this interface, it will 505 not progress on read data presented on the read data channel and the 506 system can deadlock. 507 508 The workaround promotes data cache clean instructions to 509 data cache clean-and-invalidate. 510 Please note that this does not necessarily enable the workaround, 511 as it depends on the alternative framework, which will only patch 512 the kernel if an affected CPU is detected. 513 514 If unsure, say Y. 515 516config ARM64_ERRATUM_827319 517 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 518 default y 519 select ARM64_WORKAROUND_CLEAN_CACHE 520 help 521 This option adds an alternative code sequence to work around ARM 522 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 523 master interface and an L2 cache. 524 525 Under certain conditions this erratum can cause a clean line eviction 526 to occur at the same time as another transaction to the same address 527 on the AMBA 5 CHI interface, which can cause data corruption if the 528 interconnect reorders the two transactions. 529 530 The workaround promotes data cache clean instructions to 531 data cache clean-and-invalidate. 532 Please note that this does not necessarily enable the workaround, 533 as it depends on the alternative framework, which will only patch 534 the kernel if an affected CPU is detected. 535 536 If unsure, say Y. 537 538config ARM64_ERRATUM_824069 539 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 540 default y 541 select ARM64_WORKAROUND_CLEAN_CACHE 542 help 543 This option adds an alternative code sequence to work around ARM 544 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 545 to a coherent interconnect. 546 547 If a Cortex-A53 processor is executing a store or prefetch for 548 write instruction at the same time as a processor in another 549 cluster is executing a cache maintenance operation to the same 550 address, then this erratum might cause a clean cache line to be 551 incorrectly marked as dirty. 552 553 The workaround promotes data cache clean instructions to 554 data cache clean-and-invalidate. 555 Please note that this option does not necessarily enable the 556 workaround, as it depends on the alternative framework, which will 557 only patch the kernel if an affected CPU is detected. 558 559 If unsure, say Y. 560 561config ARM64_ERRATUM_819472 562 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 563 default y 564 select ARM64_WORKAROUND_CLEAN_CACHE 565 help 566 This option adds an alternative code sequence to work around ARM 567 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 568 present when it is connected to a coherent interconnect. 569 570 If the processor is executing a load and store exclusive sequence at 571 the same time as a processor in another cluster is executing a cache 572 maintenance operation to the same address, then this erratum might 573 cause data corruption. 574 575 The workaround promotes data cache clean instructions to 576 data cache clean-and-invalidate. 577 Please note that this does not necessarily enable the workaround, 578 as it depends on the alternative framework, which will only patch 579 the kernel if an affected CPU is detected. 580 581 If unsure, say Y. 582 583config ARM64_ERRATUM_832075 584 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 585 default y 586 help 587 This option adds an alternative code sequence to work around ARM 588 erratum 832075 on Cortex-A57 parts up to r1p2. 589 590 Affected Cortex-A57 parts might deadlock when exclusive load/store 591 instructions to Write-Back memory are mixed with Device loads. 592 593 The workaround is to promote device loads to use Load-Acquire 594 semantics. 595 Please note that this does not necessarily enable the workaround, 596 as it depends on the alternative framework, which will only patch 597 the kernel if an affected CPU is detected. 598 599 If unsure, say Y. 600 601config ARM64_ERRATUM_834220 602 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 603 depends on KVM 604 help 605 This option adds an alternative code sequence to work around ARM 606 erratum 834220 on Cortex-A57 parts up to r1p2. 607 608 Affected Cortex-A57 parts might report a Stage 2 translation 609 fault as the result of a Stage 1 fault for load crossing a 610 page boundary when there is a permission or device memory 611 alignment fault at Stage 1 and a translation fault at Stage 2. 612 613 The workaround is to verify that the Stage 1 translation 614 doesn't generate a fault before handling the Stage 2 fault. 615 Please note that this does not necessarily enable the workaround, 616 as it depends on the alternative framework, which will only patch 617 the kernel if an affected CPU is detected. 618 619 If unsure, say N. 620 621config ARM64_ERRATUM_1742098 622 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 623 depends on COMPAT 624 default y 625 help 626 This option removes the AES hwcap for aarch32 user-space to 627 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 628 629 Affected parts may corrupt the AES state if an interrupt is 630 taken between a pair of AES instructions. These instructions 631 are only present if the cryptography extensions are present. 632 All software should have a fallback implementation for CPUs 633 that don't implement the cryptography extensions. 634 635 If unsure, say Y. 636 637config ARM64_ERRATUM_845719 638 bool "Cortex-A53: 845719: a load might read incorrect data" 639 depends on COMPAT 640 default y 641 help 642 This option adds an alternative code sequence to work around ARM 643 erratum 845719 on Cortex-A53 parts up to r0p4. 644 645 When running a compat (AArch32) userspace on an affected Cortex-A53 646 part, a load at EL0 from a virtual address that matches the bottom 32 647 bits of the virtual address used by a recent load at (AArch64) EL1 648 might return incorrect data. 649 650 The workaround is to write the contextidr_el1 register on exception 651 return to a 32-bit task. 652 Please note that this does not necessarily enable the workaround, 653 as it depends on the alternative framework, which will only patch 654 the kernel if an affected CPU is detected. 655 656 If unsure, say Y. 657 658config ARM64_ERRATUM_843419 659 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 660 default y 661 help 662 This option links the kernel with '--fix-cortex-a53-843419' and 663 enables PLT support to replace certain ADRP instructions, which can 664 cause subsequent memory accesses to use an incorrect address on 665 Cortex-A53 parts up to r0p4. 666 667 If unsure, say Y. 668 669config ARM64_ERRATUM_1024718 670 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 671 default y 672 help 673 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 674 675 Affected Cortex-A55 cores (all revisions) could cause incorrect 676 update of the hardware dirty bit when the DBM/AP bits are updated 677 without a break-before-make. The workaround is to disable the usage 678 of hardware DBM locally on the affected cores. CPUs not affected by 679 this erratum will continue to use the feature. 680 681 If unsure, say Y. 682 683config ARM64_ERRATUM_1418040 684 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 685 default y 686 depends on COMPAT 687 help 688 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 689 errata 1188873 and 1418040. 690 691 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 692 cause register corruption when accessing the timer registers 693 from AArch32 userspace. 694 695 If unsure, say Y. 696 697config ARM64_WORKAROUND_SPECULATIVE_AT 698 bool 699 700config ARM64_ERRATUM_1165522 701 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 702 default y 703 select ARM64_WORKAROUND_SPECULATIVE_AT 704 help 705 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 706 707 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 708 corrupted TLBs by speculating an AT instruction during a guest 709 context switch. 710 711 If unsure, say Y. 712 713config ARM64_ERRATUM_1319367 714 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 715 default y 716 select ARM64_WORKAROUND_SPECULATIVE_AT 717 help 718 This option adds work arounds for ARM Cortex-A57 erratum 1319537 719 and A72 erratum 1319367 720 721 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 722 speculating an AT instruction during a guest context switch. 723 724 If unsure, say Y. 725 726config ARM64_ERRATUM_1530923 727 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 728 default y 729 select ARM64_WORKAROUND_SPECULATIVE_AT 730 help 731 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 732 733 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 734 corrupted TLBs by speculating an AT instruction during a guest 735 context switch. 736 737 If unsure, say Y. 738 739config ARM64_WORKAROUND_REPEAT_TLBI 740 bool 741 742config ARM64_ERRATUM_2441007 743 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 744 select ARM64_WORKAROUND_REPEAT_TLBI 745 help 746 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 747 748 Under very rare circumstances, affected Cortex-A55 CPUs 749 may not handle a race between a break-before-make sequence on one 750 CPU, and another CPU accessing the same page. This could allow a 751 store to a page that has been unmapped. 752 753 Work around this by adding the affected CPUs to the list that needs 754 TLB sequences to be done twice. 755 756 If unsure, say N. 757 758config ARM64_ERRATUM_1286807 759 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 760 select ARM64_WORKAROUND_REPEAT_TLBI 761 help 762 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 763 764 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 765 address for a cacheable mapping of a location is being 766 accessed by a core while another core is remapping the virtual 767 address to a new physical page using the recommended 768 break-before-make sequence, then under very rare circumstances 769 TLBI+DSB completes before a read using the translation being 770 invalidated has been observed by other observers. The 771 workaround repeats the TLBI+DSB operation. 772 773 If unsure, say N. 774 775config ARM64_ERRATUM_1463225 776 bool "Cortex-A76: Software Step might prevent interrupt recognition" 777 default y 778 help 779 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 780 781 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 782 of a system call instruction (SVC) can prevent recognition of 783 subsequent interrupts when software stepping is disabled in the 784 exception handler of the system call and either kernel debugging 785 is enabled or VHE is in use. 786 787 Work around the erratum by triggering a dummy step exception 788 when handling a system call from a task that is being stepped 789 in a VHE configuration of the kernel. 790 791 If unsure, say Y. 792 793config ARM64_ERRATUM_1542419 794 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 795 help 796 This option adds a workaround for ARM Neoverse-N1 erratum 797 1542419. 798 799 Affected Neoverse-N1 cores could execute a stale instruction when 800 modified by another CPU. The workaround depends on a firmware 801 counterpart. 802 803 Workaround the issue by hiding the DIC feature from EL0. This 804 forces user-space to perform cache maintenance. 805 806 If unsure, say N. 807 808config ARM64_ERRATUM_1508412 809 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 810 default y 811 help 812 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 813 814 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 815 of a store-exclusive or read of PAR_EL1 and a load with device or 816 non-cacheable memory attributes. The workaround depends on a firmware 817 counterpart. 818 819 KVM guests must also have the workaround implemented or they can 820 deadlock the system. 821 822 Work around the issue by inserting DMB SY barriers around PAR_EL1 823 register reads and warning KVM users. The DMB barrier is sufficient 824 to prevent a speculative PAR_EL1 read. 825 826 If unsure, say Y. 827 828config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 829 bool 830 831config ARM64_ERRATUM_2051678 832 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 833 default y 834 help 835 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 836 Affected Cortex-A510 might not respect the ordering rules for 837 hardware update of the page table's dirty bit. The workaround 838 is to not enable the feature on affected CPUs. 839 840 If unsure, say Y. 841 842config ARM64_ERRATUM_2077057 843 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 844 default y 845 help 846 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 847 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 848 expected, but a Pointer Authentication trap is taken instead. The 849 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 850 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 851 852 This can only happen when EL2 is stepping EL1. 853 854 When these conditions occur, the SPSR_EL2 value is unchanged from the 855 previous guest entry, and can be restored from the in-memory copy. 856 857 If unsure, say Y. 858 859config ARM64_ERRATUM_2658417 860 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 861 default y 862 help 863 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 864 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 865 BFMMLA or VMMLA instructions in rare circumstances when a pair of 866 A510 CPUs are using shared neon hardware. As the sharing is not 867 discoverable by the kernel, hide the BF16 HWCAP to indicate that 868 user-space should not be using these instructions. 869 870 If unsure, say Y. 871 872config ARM64_ERRATUM_2119858 873 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 874 default y 875 depends on CORESIGHT_TRBE 876 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 877 help 878 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 879 880 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 881 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 882 the event of a WRAP event. 883 884 Work around the issue by always making sure we move the TRBPTR_EL1 by 885 256 bytes before enabling the buffer and filling the first 256 bytes of 886 the buffer with ETM ignore packets upon disabling. 887 888 If unsure, say Y. 889 890config ARM64_ERRATUM_2139208 891 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 892 default y 893 depends on CORESIGHT_TRBE 894 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 895 help 896 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 897 898 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 899 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 900 the event of a WRAP event. 901 902 Work around the issue by always making sure we move the TRBPTR_EL1 by 903 256 bytes before enabling the buffer and filling the first 256 bytes of 904 the buffer with ETM ignore packets upon disabling. 905 906 If unsure, say Y. 907 908config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 909 bool 910 911config ARM64_ERRATUM_2054223 912 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 913 default y 914 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 915 help 916 Enable workaround for ARM Cortex-A710 erratum 2054223 917 918 Affected cores may fail to flush the trace data on a TSB instruction, when 919 the PE is in trace prohibited state. This will cause losing a few bytes 920 of the trace cached. 921 922 Workaround is to issue two TSB consecutively on affected cores. 923 924 If unsure, say Y. 925 926config ARM64_ERRATUM_2067961 927 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 928 default y 929 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 930 help 931 Enable workaround for ARM Neoverse-N2 erratum 2067961 932 933 Affected cores may fail to flush the trace data on a TSB instruction, when 934 the PE is in trace prohibited state. This will cause losing a few bytes 935 of the trace cached. 936 937 Workaround is to issue two TSB consecutively on affected cores. 938 939 If unsure, say Y. 940 941config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 942 bool 943 944config ARM64_ERRATUM_2253138 945 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 946 depends on CORESIGHT_TRBE 947 default y 948 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 949 help 950 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 951 952 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 953 for TRBE. Under some conditions, the TRBE might generate a write to the next 954 virtually addressed page following the last page of the TRBE address space 955 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 956 957 Work around this in the driver by always making sure that there is a 958 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 959 960 If unsure, say Y. 961 962config ARM64_ERRATUM_2224489 963 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 964 depends on CORESIGHT_TRBE 965 default y 966 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 967 help 968 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 969 970 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 971 for TRBE. Under some conditions, the TRBE might generate a write to the next 972 virtually addressed page following the last page of the TRBE address space 973 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 974 975 Work around this in the driver by always making sure that there is a 976 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 977 978 If unsure, say Y. 979 980config ARM64_ERRATUM_2441009 981 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 982 select ARM64_WORKAROUND_REPEAT_TLBI 983 help 984 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 985 986 Under very rare circumstances, affected Cortex-A510 CPUs 987 may not handle a race between a break-before-make sequence on one 988 CPU, and another CPU accessing the same page. This could allow a 989 store to a page that has been unmapped. 990 991 Work around this by adding the affected CPUs to the list that needs 992 TLB sequences to be done twice. 993 994 If unsure, say N. 995 996config ARM64_ERRATUM_2064142 997 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 998 depends on CORESIGHT_TRBE 999 default y 1000 help 1001 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 1002 1003 Affected Cortex-A510 core might fail to write into system registers after the 1004 TRBE has been disabled. Under some conditions after the TRBE has been disabled 1005 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 1006 and TRBTRG_EL1 will be ignored and will not be effected. 1007 1008 Work around this in the driver by executing TSB CSYNC and DSB after collection 1009 is stopped and before performing a system register write to one of the affected 1010 registers. 1011 1012 If unsure, say Y. 1013 1014config ARM64_ERRATUM_2038923 1015 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1016 depends on CORESIGHT_TRBE 1017 default y 1018 help 1019 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1020 1021 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1022 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1023 might be corrupted. This happens after TRBE buffer has been enabled by setting 1024 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1025 execution changes from a context, in which trace is prohibited to one where it 1026 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1027 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1028 the trace buffer state might be corrupted. 1029 1030 Work around this in the driver by preventing an inconsistent view of whether the 1031 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1032 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1033 two ISB instructions if no ERET is to take place. 1034 1035 If unsure, say Y. 1036 1037config ARM64_ERRATUM_1902691 1038 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1039 depends on CORESIGHT_TRBE 1040 default y 1041 help 1042 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1043 1044 Affected Cortex-A510 core might cause trace data corruption, when being written 1045 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1046 trace data. 1047 1048 Work around this problem in the driver by just preventing TRBE initialization on 1049 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1050 on such implementations. This will cover the kernel for any firmware that doesn't 1051 do this already. 1052 1053 If unsure, say Y. 1054 1055config ARM64_ERRATUM_2457168 1056 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1057 depends on ARM64_AMU_EXTN 1058 default y 1059 help 1060 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1061 1062 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1063 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1064 incorrectly giving a significantly higher output value. 1065 1066 Work around this problem by returning 0 when reading the affected counter in 1067 key locations that results in disabling all users of this counter. This effect 1068 is the same to firmware disabling affected counters. 1069 1070 If unsure, say Y. 1071 1072config ARM64_ERRATUM_2645198 1073 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1074 default y 1075 help 1076 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1077 1078 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1079 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1080 next instruction abort caused by permission fault. 1081 1082 Only user-space does executable to non-executable permission transition via 1083 mprotect() system call. Workaround the problem by doing a break-before-make 1084 TLB invalidation, for all changes to executable user space mappings. 1085 1086 If unsure, say Y. 1087 1088config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1089 bool 1090 1091config ARM64_ERRATUM_2966298 1092 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1093 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1094 default y 1095 help 1096 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1097 1098 On an affected Cortex-A520 core, a speculatively executed unprivileged 1099 load might leak data from a privileged level via a cache side channel. 1100 1101 Work around this problem by executing a TLBI before returning to EL0. 1102 1103 If unsure, say Y. 1104 1105config ARM64_ERRATUM_3117295 1106 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1107 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1108 default y 1109 help 1110 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1111 1112 On an affected Cortex-A510 core, a speculatively executed unprivileged 1113 load might leak data from a privileged level via a cache side channel. 1114 1115 Work around this problem by executing a TLBI before returning to EL0. 1116 1117 If unsure, say Y. 1118 1119config ARM64_ERRATUM_3194386 1120 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1121 default y 1122 help 1123 This option adds the workaround for the following errata: 1124 1125 * ARM Cortex-A76 erratum 3324349 1126 * ARM Cortex-A77 erratum 3324348 1127 * ARM Cortex-A78 erratum 3324344 1128 * ARM Cortex-A78C erratum 3324346 1129 * ARM Cortex-A78C erratum 3324347 1130 * ARM Cortex-A710 erratam 3324338 1131 * ARM Cortex-A715 errartum 3456084 1132 * ARM Cortex-A720 erratum 3456091 1133 * ARM Cortex-A725 erratum 3456106 1134 * ARM Cortex-X1 erratum 3324344 1135 * ARM Cortex-X1C erratum 3324346 1136 * ARM Cortex-X2 erratum 3324338 1137 * ARM Cortex-X3 erratum 3324335 1138 * ARM Cortex-X4 erratum 3194386 1139 * ARM Cortex-X925 erratum 3324334 1140 * ARM Neoverse-N1 erratum 3324349 1141 * ARM Neoverse N2 erratum 3324339 1142 * ARM Neoverse-N3 erratum 3456111 1143 * ARM Neoverse-V1 erratum 3324341 1144 * ARM Neoverse V2 erratum 3324336 1145 * ARM Neoverse-V3 erratum 3312417 1146 * ARM Neoverse-V3AE erratum 3312417 1147 1148 On affected cores "MSR SSBS, #0" instructions may not affect 1149 subsequent speculative instructions, which may permit unexepected 1150 speculative store bypassing. 1151 1152 Work around this problem by placing a Speculation Barrier (SB) or 1153 Instruction Synchronization Barrier (ISB) after kernel changes to 1154 SSBS. The presence of the SSBS special-purpose register is hidden 1155 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1156 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1157 1158 If unsure, say Y. 1159 1160config ARM64_ERRATUM_4311569 1161 bool "SI L1: 4311569: workaround for premature CMO completion erratum" 1162 default y 1163 help 1164 This option adds the workaround for ARM SI L1 erratum 4311569. 1165 1166 The erratum of SI L1 can cause an early response to a combined write 1167 and cache maintenance operation (WR+CMO) before the operation is fully 1168 completed to the Point of Serialization (POS). 1169 This can result in a non-I/O coherent agent observing stale data, 1170 potentially leading to system instability or incorrect behavior. 1171 1172 Enabling this option implements a software workaround by inserting a 1173 second loop of Cache Maintenance Operation (CMO) immediately following the 1174 end of function to do CMOs. This ensures that the data is correctly serialized 1175 before the buffer is handed off to a non-coherent agent. 1176 1177 If unsure, say Y. 1178 1179config CAVIUM_ERRATUM_22375 1180 bool "Cavium erratum 22375, 24313" 1181 default y 1182 help 1183 Enable workaround for errata 22375 and 24313. 1184 1185 This implements two gicv3-its errata workarounds for ThunderX. Both 1186 with a small impact affecting only ITS table allocation. 1187 1188 erratum 22375: only alloc 8MB table size 1189 erratum 24313: ignore memory access type 1190 1191 The fixes are in ITS initialization and basically ignore memory access 1192 type and table size provided by the TYPER and BASER registers. 1193 1194 If unsure, say Y. 1195 1196config CAVIUM_ERRATUM_23144 1197 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1198 depends on NUMA 1199 default y 1200 help 1201 ITS SYNC command hang for cross node io and collections/cpu mapping. 1202 1203 If unsure, say Y. 1204 1205config CAVIUM_ERRATUM_23154 1206 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1207 default y 1208 help 1209 The ThunderX GICv3 implementation requires a modified version for 1210 reading the IAR status to ensure data synchronization 1211 (access to icc_iar1_el1 is not sync'ed before and after). 1212 1213 It also suffers from erratum 38545 (also present on Marvell's 1214 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1215 spuriously presented to the CPU interface. 1216 1217 If unsure, say Y. 1218 1219config CAVIUM_ERRATUM_27456 1220 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1221 default y 1222 help 1223 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1224 instructions may cause the icache to become corrupted if it 1225 contains data for a non-current ASID. The fix is to 1226 invalidate the icache when changing the mm context. 1227 1228 If unsure, say Y. 1229 1230config CAVIUM_ERRATUM_30115 1231 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1232 default y 1233 help 1234 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1235 1.2, and T83 Pass 1.0, KVM guest execution may disable 1236 interrupts in host. Trapping both GICv3 group-0 and group-1 1237 accesses sidesteps the issue. 1238 1239 If unsure, say Y. 1240 1241config CAVIUM_TX2_ERRATUM_219 1242 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1243 default y 1244 help 1245 On Cavium ThunderX2, a load, store or prefetch instruction between a 1246 TTBR update and the corresponding context synchronizing operation can 1247 cause a spurious Data Abort to be delivered to any hardware thread in 1248 the CPU core. 1249 1250 Work around the issue by avoiding the problematic code sequence and 1251 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1252 trap handler performs the corresponding register access, skips the 1253 instruction and ensures context synchronization by virtue of the 1254 exception return. 1255 1256 If unsure, say Y. 1257 1258config FUJITSU_ERRATUM_010001 1259 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1260 default y 1261 help 1262 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1263 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1264 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1265 This fault occurs under a specific hardware condition when a 1266 load/store instruction performs an address translation using: 1267 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1268 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1269 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1270 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1271 1272 The workaround is to ensure these bits are clear in TCR_ELx. 1273 The workaround only affects the Fujitsu-A64FX. 1274 1275 If unsure, say Y. 1276 1277config HISILICON_ERRATUM_161600802 1278 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1279 default y 1280 help 1281 The HiSilicon Hip07 SoC uses the wrong redistributor base 1282 when issued ITS commands such as VMOVP and VMAPP, and requires 1283 a 128kB offset to be applied to the target address in this commands. 1284 1285 If unsure, say Y. 1286 1287config HISILICON_ERRATUM_162100801 1288 bool "Hip09 162100801 erratum support" 1289 default y 1290 help 1291 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1292 during unmapping operation, which will cause some vSGIs lost. 1293 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1294 after VMOVP. 1295 1296 If unsure, say Y. 1297 1298config QCOM_FALKOR_ERRATUM_1003 1299 bool "Falkor E1003: Incorrect translation due to ASID change" 1300 default y 1301 help 1302 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1303 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1304 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1305 then only for entries in the walk cache, since the leaf translation 1306 is unchanged. Work around the erratum by invalidating the walk cache 1307 entries for the trampoline before entering the kernel proper. 1308 1309config QCOM_FALKOR_ERRATUM_1009 1310 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1311 default y 1312 select ARM64_WORKAROUND_REPEAT_TLBI 1313 help 1314 On Falkor v1, the CPU may prematurely complete a DSB following a 1315 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1316 one more time to fix the issue. 1317 1318 If unsure, say Y. 1319 1320config QCOM_QDF2400_ERRATUM_0065 1321 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1322 default y 1323 help 1324 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1325 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1326 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1327 1328 If unsure, say Y. 1329 1330config QCOM_FALKOR_ERRATUM_E1041 1331 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1332 default y 1333 help 1334 Falkor CPU may speculatively fetch instructions from an improper 1335 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1336 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1337 1338 If unsure, say Y. 1339 1340config NVIDIA_CARMEL_CNP_ERRATUM 1341 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1342 default y 1343 help 1344 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1345 invalidate shared TLB entries installed by a different core, as it would 1346 on standard ARM cores. 1347 1348 If unsure, say Y. 1349 1350config ROCKCHIP_ERRATUM_3568002 1351 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1352 default y 1353 help 1354 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1355 addressing limited to the first 32bit of physical address space. 1356 1357 If unsure, say Y. 1358 1359config ROCKCHIP_ERRATUM_3588001 1360 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1361 default y 1362 help 1363 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1364 This means, that its sharability feature may not be used, even though it 1365 is supported by the IP itself. 1366 1367 If unsure, say Y. 1368 1369config SOCIONEXT_SYNQUACER_PREITS 1370 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1371 default y 1372 help 1373 Socionext Synquacer SoCs implement a separate h/w block to generate 1374 MSI doorbell writes with non-zero values for the device ID. 1375 1376 If unsure, say Y. 1377 1378endmenu # "ARM errata workarounds via the alternatives framework" 1379 1380choice 1381 prompt "Page size" 1382 default ARM64_4K_PAGES 1383 help 1384 Page size (translation granule) configuration. 1385 1386config ARM64_4K_PAGES 1387 bool "4KB" 1388 select HAVE_PAGE_SIZE_4KB 1389 help 1390 This feature enables 4KB pages support. 1391 1392config ARM64_16K_PAGES 1393 bool "16KB" 1394 select HAVE_PAGE_SIZE_16KB 1395 help 1396 The system will use 16KB pages support. AArch32 emulation 1397 requires applications compiled with 16K (or a multiple of 16K) 1398 aligned segments. 1399 1400config ARM64_64K_PAGES 1401 bool "64KB" 1402 select HAVE_PAGE_SIZE_64KB 1403 help 1404 This feature enables 64KB pages support (4KB by default) 1405 allowing only two levels of page tables and faster TLB 1406 look-up. AArch32 emulation requires applications compiled 1407 with 64K aligned segments. 1408 1409endchoice 1410 1411choice 1412 prompt "Virtual address space size" 1413 default ARM64_VA_BITS_52 1414 help 1415 Allows choosing one of multiple possible virtual address 1416 space sizes. The level of translation table is determined by 1417 a combination of page size and virtual address space size. 1418 1419config ARM64_VA_BITS_36 1420 bool "36-bit" if EXPERT 1421 depends on PAGE_SIZE_16KB 1422 1423config ARM64_VA_BITS_39 1424 bool "39-bit" 1425 depends on PAGE_SIZE_4KB 1426 1427config ARM64_VA_BITS_42 1428 bool "42-bit" 1429 depends on PAGE_SIZE_64KB 1430 1431config ARM64_VA_BITS_47 1432 bool "47-bit" 1433 depends on PAGE_SIZE_16KB 1434 1435config ARM64_VA_BITS_48 1436 bool "48-bit" 1437 1438config ARM64_VA_BITS_52 1439 bool "52-bit" 1440 help 1441 Enable 52-bit virtual addressing for userspace when explicitly 1442 requested via a hint to mmap(). The kernel will also use 52-bit 1443 virtual addresses for its own mappings (provided HW support for 1444 this feature is available, otherwise it reverts to 48-bit). 1445 1446 NOTE: Enabling 52-bit virtual addressing in conjunction with 1447 ARMv8.3 Pointer Authentication will result in the PAC being 1448 reduced from 7 bits to 3 bits, which may have a significant 1449 impact on its susceptibility to brute-force attacks. 1450 1451 If unsure, select 48-bit virtual addressing instead. 1452 1453endchoice 1454 1455config ARM64_FORCE_52BIT 1456 bool "Force 52-bit virtual addresses for userspace" 1457 depends on ARM64_VA_BITS_52 && EXPERT 1458 help 1459 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1460 to maintain compatibility with older software by providing 48-bit VAs 1461 unless a hint is supplied to mmap. 1462 1463 This configuration option disables the 48-bit compatibility logic, and 1464 forces all userspace addresses to be 52-bit on HW that supports it. One 1465 should only enable this configuration option for stress testing userspace 1466 memory management code. If unsure say N here. 1467 1468config ARM64_VA_BITS 1469 int 1470 default 36 if ARM64_VA_BITS_36 1471 default 39 if ARM64_VA_BITS_39 1472 default 42 if ARM64_VA_BITS_42 1473 default 47 if ARM64_VA_BITS_47 1474 default 48 if ARM64_VA_BITS_48 1475 default 52 if ARM64_VA_BITS_52 1476 1477choice 1478 prompt "Physical address space size" 1479 default ARM64_PA_BITS_48 1480 help 1481 Choose the maximum physical address range that the kernel will 1482 support. 1483 1484config ARM64_PA_BITS_48 1485 bool "48-bit" 1486 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1487 1488config ARM64_PA_BITS_52 1489 bool "52-bit" 1490 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1491 help 1492 Enable support for a 52-bit physical address space, introduced as 1493 part of the ARMv8.2-LPA extension. 1494 1495 With this enabled, the kernel will also continue to work on CPUs that 1496 do not support ARMv8.2-LPA, but with some added memory overhead (and 1497 minor performance overhead). 1498 1499endchoice 1500 1501config ARM64_PA_BITS 1502 int 1503 default 48 if ARM64_PA_BITS_48 1504 default 52 if ARM64_PA_BITS_52 1505 1506config ARM64_LPA2 1507 def_bool y 1508 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1509 1510choice 1511 prompt "Endianness" 1512 default CPU_LITTLE_ENDIAN 1513 help 1514 Select the endianness of data accesses performed by the CPU. Userspace 1515 applications will need to be compiled and linked for the endianness 1516 that is selected here. 1517 1518config CPU_BIG_ENDIAN 1519 bool "Build big-endian kernel" 1520 depends on BROKEN 1521 help 1522 Say Y if you plan on running a kernel with a big-endian userspace. 1523 1524config CPU_LITTLE_ENDIAN 1525 bool "Build little-endian kernel" 1526 help 1527 Say Y if you plan on running a kernel with a little-endian userspace. 1528 This is usually the case for distributions targeting arm64. 1529 1530endchoice 1531 1532config NR_CPUS 1533 int "Maximum number of CPUs (2-4096)" 1534 range 2 4096 1535 default "512" 1536 1537config HOTPLUG_CPU 1538 bool "Support for hot-pluggable CPUs" 1539 select GENERIC_IRQ_MIGRATION 1540 help 1541 Say Y here to experiment with turning CPUs off and on. CPUs 1542 can be controlled through /sys/devices/system/cpu. 1543 1544# Common NUMA Features 1545config NUMA 1546 bool "NUMA Memory Allocation and Scheduler Support" 1547 select GENERIC_ARCH_NUMA 1548 select OF_NUMA 1549 select HAVE_SETUP_PER_CPU_AREA 1550 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1551 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1552 select USE_PERCPU_NUMA_NODE_ID 1553 help 1554 Enable NUMA (Non-Uniform Memory Access) support. 1555 1556 The kernel will try to allocate memory used by a CPU on the 1557 local memory of the CPU and add some more 1558 NUMA awareness to the kernel. 1559 1560config NODES_SHIFT 1561 int "Maximum NUMA Nodes (as a power of 2)" 1562 range 1 10 1563 default "4" 1564 depends on NUMA 1565 help 1566 Specify the maximum number of NUMA Nodes available on the target 1567 system. Increases memory reserved to accommodate various tables. 1568 1569source "kernel/Kconfig.hz" 1570 1571config ARCH_SPARSEMEM_ENABLE 1572 def_bool y 1573 select SPARSEMEM_VMEMMAP_ENABLE 1574 1575config HW_PERF_EVENTS 1576 def_bool y 1577 depends on ARM_PMU 1578 1579# Supported by clang >= 7.0 or GCC >= 12.0.0 1580config CC_HAVE_SHADOW_CALL_STACK 1581 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1582 1583config PARAVIRT 1584 bool "Enable paravirtualization code" 1585 select HAVE_PV_STEAL_CLOCK_GEN 1586 help 1587 This changes the kernel so it can modify itself when it is run 1588 under a hypervisor, potentially improving performance significantly 1589 over full virtualization. 1590 1591config PARAVIRT_TIME_ACCOUNTING 1592 bool "Paravirtual steal time accounting" 1593 select PARAVIRT 1594 help 1595 Select this option to enable fine granularity task steal time 1596 accounting. Time spent executing other tasks in parallel with 1597 the current vCPU is discounted from the vCPU power. To account for 1598 that, there can be a small performance impact. 1599 1600 If in doubt, say N here. 1601 1602config ARCH_SUPPORTS_KEXEC 1603 def_bool PM_SLEEP_SMP 1604 1605config ARCH_SUPPORTS_KEXEC_FILE 1606 def_bool y 1607 1608config ARCH_SELECTS_KEXEC_FILE 1609 def_bool y 1610 depends on KEXEC_FILE 1611 select HAVE_IMA_KEXEC if IMA 1612 1613config ARCH_SUPPORTS_KEXEC_SIG 1614 def_bool y 1615 1616config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1617 def_bool y 1618 1619config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1620 def_bool y 1621 1622config ARCH_SUPPORTS_KEXEC_HANDOVER 1623 def_bool y 1624 1625config ARCH_SUPPORTS_CRASH_DUMP 1626 def_bool y 1627 1628config ARCH_DEFAULT_CRASH_DUMP 1629 def_bool y 1630 1631config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1632 def_bool CRASH_RESERVE 1633 1634config TRANS_TABLE 1635 def_bool y 1636 depends on HIBERNATION || KEXEC_CORE 1637 1638config XEN_DOM0 1639 def_bool y 1640 depends on XEN 1641 1642config XEN 1643 bool "Xen guest support on ARM64" 1644 depends on ARM64 && OF 1645 select SWIOTLB_XEN 1646 select PARAVIRT 1647 help 1648 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1649 1650# include/linux/mmzone.h requires the following to be true: 1651# 1652# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1653# 1654# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1655# 1656# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1657# ----+-------------------+--------------+----------------------+-------------------------+ 1658# 4K | 27 | 12 | 15 | 10 | 1659# 16K | 27 | 14 | 13 | 11 | 1660# 64K | 29 | 16 | 13 | 13 | 1661config ARCH_FORCE_MAX_ORDER 1662 int 1663 default "13" if ARM64_64K_PAGES 1664 default "11" if ARM64_16K_PAGES 1665 default "10" 1666 help 1667 The kernel page allocator limits the size of maximal physically 1668 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1669 defines the maximal power of two of number of pages that can be 1670 allocated as a single contiguous block. This option allows 1671 overriding the default setting when ability to allocate very 1672 large blocks of physically contiguous memory is required. 1673 1674 The maximal size of allocation cannot exceed the size of the 1675 section, so the value of MAX_PAGE_ORDER should satisfy 1676 1677 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1678 1679 Don't change if unsure. 1680 1681config UNMAP_KERNEL_AT_EL0 1682 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1683 default y 1684 help 1685 Speculation attacks against some high-performance processors can 1686 be used to bypass MMU permission checks and leak kernel data to 1687 userspace. This can be defended against by unmapping the kernel 1688 when running in userspace, mapping it back in on exception entry 1689 via a trampoline page in the vector table. 1690 1691 If unsure, say Y. 1692 1693config MITIGATE_SPECTRE_BRANCH_HISTORY 1694 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1695 default y 1696 help 1697 Speculation attacks against some high-performance processors can 1698 make use of branch history to influence future speculation. 1699 When taking an exception from user-space, a sequence of branches 1700 or a firmware call overwrites the branch history. 1701 1702config ARM64_SW_TTBR0_PAN 1703 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1704 depends on !KCSAN 1705 help 1706 Enabling this option prevents the kernel from accessing 1707 user-space memory directly by pointing TTBR0_EL1 to a reserved 1708 zeroed area and reserved ASID. The user access routines 1709 restore the valid TTBR0_EL1 temporarily. 1710 1711config ARM64_TAGGED_ADDR_ABI 1712 bool "Enable the tagged user addresses syscall ABI" 1713 default y 1714 help 1715 When this option is enabled, user applications can opt in to a 1716 relaxed ABI via prctl() allowing tagged addresses to be passed 1717 to system calls as pointer arguments. For details, see 1718 Documentation/arch/arm64/tagged-address-abi.rst. 1719 1720menuconfig COMPAT 1721 bool "Kernel support for 32-bit EL0" 1722 depends on ARM64_4K_PAGES || EXPERT 1723 select HAVE_UID16 1724 select OLD_SIGSUSPEND3 1725 select COMPAT_OLD_SIGACTION 1726 help 1727 This option enables support for a 32-bit EL0 running under a 64-bit 1728 kernel at EL1. AArch32-specific components such as system calls, 1729 the user helper functions, VFP support and the ptrace interface are 1730 handled appropriately by the kernel. 1731 1732 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1733 that you will only be able to execute AArch32 binaries that were compiled 1734 with page size aligned segments. 1735 1736 If you want to execute 32-bit userspace applications, say Y. 1737 1738if COMPAT 1739 1740config KUSER_HELPERS 1741 bool "Enable kuser helpers page for 32-bit applications" 1742 default y 1743 help 1744 Warning: disabling this option may break 32-bit user programs. 1745 1746 Provide kuser helpers to compat tasks. The kernel provides 1747 helper code to userspace in read only form at a fixed location 1748 to allow userspace to be independent of the CPU type fitted to 1749 the system. This permits binaries to be run on ARMv4 through 1750 to ARMv8 without modification. 1751 1752 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1753 1754 However, the fixed address nature of these helpers can be used 1755 by ROP (return orientated programming) authors when creating 1756 exploits. 1757 1758 If all of the binaries and libraries which run on your platform 1759 are built specifically for your platform, and make no use of 1760 these helpers, then you can turn this option off to hinder 1761 such exploits. However, in that case, if a binary or library 1762 relying on those helpers is run, it will not function correctly. 1763 1764 Say N here only if you are absolutely certain that you do not 1765 need these helpers; otherwise, the safe option is to say Y. 1766 1767config COMPAT_VDSO 1768 bool "Enable vDSO for 32-bit applications" 1769 depends on !CPU_BIG_ENDIAN 1770 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1771 default y 1772 help 1773 Place in the process address space of 32-bit applications an 1774 ELF shared object providing fast implementations of gettimeofday 1775 and clock_gettime. 1776 1777 You must have a 32-bit build of glibc 2.22 or later for programs 1778 to seamlessly take advantage of this. 1779 1780config THUMB2_COMPAT_VDSO 1781 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1782 depends on COMPAT_VDSO 1783 default y 1784 help 1785 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1786 otherwise with '-marm'. 1787 1788config COMPAT_ALIGNMENT_FIXUPS 1789 bool "Fix up misaligned multi-word loads and stores in user space" 1790 1791menuconfig ARMV8_DEPRECATED 1792 bool "Emulate deprecated/obsolete ARMv8 instructions" 1793 depends on SYSCTL 1794 help 1795 Legacy software support may require certain instructions 1796 that have been deprecated or obsoleted in the architecture. 1797 1798 Enable this config to enable selective emulation of these 1799 features. 1800 1801 If unsure, say Y 1802 1803if ARMV8_DEPRECATED 1804 1805config SWP_EMULATION 1806 bool "Emulate SWP/SWPB instructions" 1807 help 1808 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1809 they are always undefined. Say Y here to enable software 1810 emulation of these instructions for userspace using LDXR/STXR. 1811 This feature can be controlled at runtime with the abi.swp 1812 sysctl which is disabled by default. 1813 1814 In some older versions of glibc [<=2.8] SWP is used during futex 1815 trylock() operations with the assumption that the code will not 1816 be preempted. This invalid assumption may be more likely to fail 1817 with SWP emulation enabled, leading to deadlock of the user 1818 application. 1819 1820 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1821 on an external transaction monitoring block called a global 1822 monitor to maintain update atomicity. If your system does not 1823 implement a global monitor, this option can cause programs that 1824 perform SWP operations to uncached memory to deadlock. 1825 1826 If unsure, say Y 1827 1828config CP15_BARRIER_EMULATION 1829 bool "Emulate CP15 Barrier instructions" 1830 help 1831 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1832 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1833 strongly recommended to use the ISB, DSB, and DMB 1834 instructions instead. 1835 1836 Say Y here to enable software emulation of these 1837 instructions for AArch32 userspace code. When this option is 1838 enabled, CP15 barrier usage is traced which can help 1839 identify software that needs updating. This feature can be 1840 controlled at runtime with the abi.cp15_barrier sysctl. 1841 1842 If unsure, say Y 1843 1844config SETEND_EMULATION 1845 bool "Emulate SETEND instruction" 1846 help 1847 The SETEND instruction alters the data-endianness of the 1848 AArch32 EL0, and is deprecated in ARMv8. 1849 1850 Say Y here to enable software emulation of the instruction 1851 for AArch32 userspace code. This feature can be controlled 1852 at runtime with the abi.setend sysctl. 1853 1854 Note: All the cpus on the system must have mixed endian support at EL0 1855 for this feature to be enabled. If a new CPU - which doesn't support mixed 1856 endian - is hotplugged in after this feature has been enabled, there could 1857 be unexpected results in the applications. 1858 1859 If unsure, say Y 1860endif # ARMV8_DEPRECATED 1861 1862endif # COMPAT 1863 1864menu "ARMv8.1 architectural features" 1865 1866config ARM64_HW_AFDBM 1867 bool "Support for hardware updates of the Access and Dirty page flags" 1868 default y 1869 help 1870 The ARMv8.1 architecture extensions introduce support for 1871 hardware updates of the access and dirty information in page 1872 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1873 capable processors, accesses to pages with PTE_AF cleared will 1874 set this bit instead of raising an access flag fault. 1875 Similarly, writes to read-only pages with the DBM bit set will 1876 clear the read-only bit (AP[2]) instead of raising a 1877 permission fault. 1878 1879 Kernels built with this configuration option enabled continue 1880 to work on pre-ARMv8.1 hardware and the performance impact is 1881 minimal. If unsure, say Y. 1882 1883endmenu # "ARMv8.1 architectural features" 1884 1885menu "ARMv8.2 architectural features" 1886 1887config ARM64_PMEM 1888 bool "Enable support for persistent memory" 1889 select ARCH_HAS_PMEM_API 1890 select ARCH_HAS_UACCESS_FLUSHCACHE 1891 help 1892 Say Y to enable support for the persistent memory API based on the 1893 ARMv8.2 DCPoP feature. 1894 1895 The feature is detected at runtime, and the kernel will use DC CVAC 1896 operations if DC CVAP is not supported (following the behaviour of 1897 DC CVAP itself if the system does not define a point of persistence). 1898 1899config ARM64_RAS_EXTN 1900 bool "Enable support for RAS CPU Extensions" 1901 default y 1902 help 1903 CPUs that support the Reliability, Availability and Serviceability 1904 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1905 errors, classify them and report them to software. 1906 1907 On CPUs with these extensions system software can use additional 1908 barriers to determine if faults are pending and read the 1909 classification from a new set of registers. 1910 1911 Selecting this feature will allow the kernel to use these barriers 1912 and access the new registers if the system supports the extension. 1913 Platform RAS features may additionally depend on firmware support. 1914 1915config ARM64_CNP 1916 bool "Enable support for Common Not Private (CNP) translations" 1917 default y 1918 help 1919 Common Not Private (CNP) allows translation table entries to 1920 be shared between different PEs in the same inner shareable 1921 domain, so the hardware can use this fact to optimise the 1922 caching of such entries in the TLB. 1923 1924 Selecting this option allows the CNP feature to be detected 1925 at runtime, and does not affect PEs that do not implement 1926 this feature. 1927 1928endmenu # "ARMv8.2 architectural features" 1929 1930menu "ARMv8.3 architectural features" 1931 1932config ARM64_PTR_AUTH 1933 bool "Enable support for pointer authentication" 1934 default y 1935 help 1936 Pointer authentication (part of the ARMv8.3 Extensions) provides 1937 instructions for signing and authenticating pointers against secret 1938 keys, which can be used to mitigate Return Oriented Programming (ROP) 1939 and other attacks. 1940 1941 This option enables these instructions at EL0 (i.e. for userspace). 1942 Choosing this option will cause the kernel to initialise secret keys 1943 for each process at exec() time, with these keys being 1944 context-switched along with the process. 1945 1946 The feature is detected at runtime. If the feature is not present in 1947 hardware it will not be advertised to userspace/KVM guest nor will it 1948 be enabled. 1949 1950 If the feature is present on the boot CPU but not on a late CPU, then 1951 the late CPU will be parked. Also, if the boot CPU does not have 1952 address auth and the late CPU has then the late CPU will still boot 1953 but with the feature disabled. On such a system, this option should 1954 not be selected. 1955 1956config ARM64_PTR_AUTH_KERNEL 1957 bool "Use pointer authentication for kernel" 1958 default y 1959 depends on ARM64_PTR_AUTH 1960 # Modern compilers insert a .note.gnu.property section note for PAC 1961 # which is only understood by binutils starting with version 2.33.1. 1962 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1963 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1964 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 1965 help 1966 If the compiler supports the -mbranch-protection or 1967 -msign-return-address flag (e.g. GCC 7 or later), then this option 1968 will cause the kernel itself to be compiled with return address 1969 protection. In this case, and if the target hardware is known to 1970 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1971 disabled with minimal loss of protection. 1972 1973 This feature works with FUNCTION_GRAPH_TRACER option only if 1974 DYNAMIC_FTRACE_WITH_ARGS is enabled. 1975 1976config CC_HAS_BRANCH_PROT_PAC_RET 1977 # GCC 9 or later, clang 8 or later 1978 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1979 1980config AS_HAS_CFI_NEGATE_RA_STATE 1981 # binutils 2.34+ 1982 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1983 1984endmenu # "ARMv8.3 architectural features" 1985 1986menu "ARMv8.4 architectural features" 1987 1988config ARM64_AMU_EXTN 1989 bool "Enable support for the Activity Monitors Unit CPU extension" 1990 default y 1991 help 1992 The activity monitors extension is an optional extension introduced 1993 by the ARMv8.4 CPU architecture. This enables support for version 1 1994 of the activity monitors architecture, AMUv1. 1995 1996 To enable the use of this extension on CPUs that implement it, say Y. 1997 1998 Note that for architectural reasons, firmware _must_ implement AMU 1999 support when running on CPUs that present the activity monitors 2000 extension. The required support is present in: 2001 * Version 1.5 and later of the ARM Trusted Firmware 2002 2003 For kernels that have this configuration enabled but boot with broken 2004 firmware, you may need to say N here until the firmware is fixed. 2005 Otherwise you may experience firmware panics or lockups when 2006 accessing the counter registers. Even if you are not observing these 2007 symptoms, the values returned by the register reads might not 2008 correctly reflect reality. Most commonly, the value read will be 0, 2009 indicating that the counter is not enabled. 2010 2011config ARM64_TLB_RANGE 2012 bool "Enable support for tlbi range feature" 2013 default y 2014 help 2015 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2016 range of input addresses. 2017 2018config ARM64_MPAM 2019 bool "Enable support for MPAM" 2020 select ARM64_MPAM_DRIVER if EXPERT # does nothing yet 2021 select ACPI_MPAM if ACPI 2022 help 2023 Memory System Resource Partitioning and Monitoring (MPAM) is an 2024 optional extension to the Arm architecture that allows each 2025 transaction issued to the memory system to be labelled with a 2026 Partition identifier (PARTID) and Performance Monitoring Group 2027 identifier (PMG). 2028 2029 Memory system components, such as the caches, can be configured with 2030 policies to control how much of various physical resources (such as 2031 memory bandwidth or cache memory) the transactions labelled with each 2032 PARTID can consume. Depending on the capabilities of the hardware, 2033 the PARTID and PMG can also be used as filtering criteria to measure 2034 the memory system resource consumption of different parts of a 2035 workload. 2036 2037 Use of this extension requires CPU support, support in the 2038 Memory System Components (MSC), and a description from firmware 2039 of where the MSCs are in the address space. 2040 2041 MPAM is exposed to user-space via the resctrl pseudo filesystem. 2042 2043endmenu # "ARMv8.4 architectural features" 2044 2045menu "ARMv8.5 architectural features" 2046 2047config AS_HAS_ARMV8_5 2048 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2049 2050config ARM64_BTI 2051 bool "Branch Target Identification support" 2052 default y 2053 help 2054 Branch Target Identification (part of the ARMv8.5 Extensions) 2055 provides a mechanism to limit the set of locations to which computed 2056 branch instructions such as BR or BLR can jump. 2057 2058 To make use of BTI on CPUs that support it, say Y. 2059 2060 BTI is intended to provide complementary protection to other control 2061 flow integrity protection mechanisms, such as the Pointer 2062 authentication mechanism provided as part of the ARMv8.3 Extensions. 2063 For this reason, it does not make sense to enable this option without 2064 also enabling support for pointer authentication. Thus, when 2065 enabling this option you should also select ARM64_PTR_AUTH=y. 2066 2067 Userspace binaries must also be specifically compiled to make use of 2068 this mechanism. If you say N here or the hardware does not support 2069 BTI, such binaries can still run, but you get no additional 2070 enforcement of branch destinations. 2071 2072config ARM64_BTI_KERNEL 2073 bool "Use Branch Target Identification for kernel" 2074 default y 2075 depends on ARM64_BTI 2076 depends on ARM64_PTR_AUTH_KERNEL 2077 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2078 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2079 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2080 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2081 depends on !CC_IS_GCC 2082 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2083 help 2084 Build the kernel with Branch Target Identification annotations 2085 and enable enforcement of this for kernel code. When this option 2086 is enabled and the system supports BTI all kernel code including 2087 modular code must have BTI enabled. 2088 2089config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2090 # GCC 9 or later, clang 8 or later 2091 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2092 2093config ARM64_E0PD 2094 bool "Enable support for E0PD" 2095 default y 2096 help 2097 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2098 that EL0 accesses made via TTBR1 always fault in constant time, 2099 providing similar benefits to KASLR as those provided by KPTI, but 2100 with lower overhead and without disrupting legitimate access to 2101 kernel memory such as SPE. 2102 2103 This option enables E0PD for TTBR1 where available. 2104 2105config ARM64_AS_HAS_MTE 2106 # Initial support for MTE went in binutils 2.32.0, checked with 2107 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2108 # as a late addition to the final architecture spec (LDGM/STGM) 2109 # is only supported in the newer 2.32.x and 2.33 binutils 2110 # versions, hence the extra "stgm" instruction check below. 2111 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2112 2113config ARM64_MTE 2114 bool "Memory Tagging Extension support" 2115 default y 2116 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2117 depends on AS_HAS_ARMV8_5 2118 # Required for tag checking in the uaccess routines 2119 select ARCH_HAS_SUBPAGE_FAULTS 2120 select ARCH_USES_HIGH_VMA_FLAGS 2121 select ARCH_USES_PG_ARCH_2 2122 select ARCH_USES_PG_ARCH_3 2123 help 2124 Memory Tagging (part of the ARMv8.5 Extensions) provides 2125 architectural support for run-time, always-on detection of 2126 various classes of memory error to aid with software debugging 2127 to eliminate vulnerabilities arising from memory-unsafe 2128 languages. 2129 2130 This option enables the support for the Memory Tagging 2131 Extension at EL0 (i.e. for userspace). 2132 2133 Selecting this option allows the feature to be detected at 2134 runtime. Any secondary CPU not implementing this feature will 2135 not be allowed a late bring-up. 2136 2137 Userspace binaries that want to use this feature must 2138 explicitly opt in. The mechanism for the userspace is 2139 described in: 2140 2141 Documentation/arch/arm64/memory-tagging-extension.rst. 2142 2143endmenu # "ARMv8.5 architectural features" 2144 2145menu "ARMv8.7 architectural features" 2146 2147config ARM64_EPAN 2148 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2149 default y 2150 help 2151 Enhanced Privileged Access Never (EPAN) allows Privileged 2152 Access Never to be used with Execute-only mappings. 2153 2154 The feature is detected at runtime, and will remain disabled 2155 if the cpu does not implement the feature. 2156endmenu # "ARMv8.7 architectural features" 2157 2158config AS_HAS_MOPS 2159 def_bool $(as-instr,.arch_extension mops) 2160 2161menu "ARMv8.9 architectural features" 2162 2163config ARM64_POE 2164 prompt "Permission Overlay Extension" 2165 def_bool y 2166 select ARCH_USES_HIGH_VMA_FLAGS 2167 select ARCH_HAS_PKEYS 2168 help 2169 The Permission Overlay Extension is used to implement Memory 2170 Protection Keys. Memory Protection Keys provides a mechanism for 2171 enforcing page-based protections, but without requiring modification 2172 of the page tables when an application changes protection domains. 2173 2174 For details, see Documentation/core-api/protection-keys.rst 2175 2176 If unsure, say y. 2177 2178config ARCH_PKEY_BITS 2179 int 2180 default 3 2181 2182config ARM64_HAFT 2183 bool "Support for Hardware managed Access Flag for Table Descriptors" 2184 depends on ARM64_HW_AFDBM 2185 default y 2186 help 2187 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2188 Flag for Table descriptors. When enabled an architectural executed 2189 memory access will update the Access Flag in each Table descriptor 2190 which is accessed during the translation table walk and for which 2191 the Access Flag is 0. The Access Flag of the Table descriptor use 2192 the same bit of PTE_AF. 2193 2194 The feature will only be enabled if all the CPUs in the system 2195 support this feature. If unsure, say Y. 2196 2197endmenu # "ARMv8.9 architectural features" 2198 2199menu "ARMv9.4 architectural features" 2200 2201config ARM64_GCS 2202 bool "Enable support for Guarded Control Stack (GCS)" 2203 default y 2204 select ARCH_HAS_USER_SHADOW_STACK 2205 select ARCH_USES_HIGH_VMA_FLAGS 2206 help 2207 Guarded Control Stack (GCS) provides support for a separate 2208 stack with restricted access which contains only return 2209 addresses. This can be used to harden against some attacks 2210 by comparing return address used by the program with what is 2211 stored in the GCS, and may also be used to efficiently obtain 2212 the call stack for applications such as profiling. 2213 2214 The feature is detected at runtime, and will remain disabled 2215 if the system does not implement the feature. 2216 2217endmenu # "ARMv9.4 architectural features" 2218 2219config ARM64_SVE 2220 bool "ARM Scalable Vector Extension support" 2221 default y 2222 help 2223 The Scalable Vector Extension (SVE) is an extension to the AArch64 2224 execution state which complements and extends the SIMD functionality 2225 of the base architecture to support much larger vectors and to enable 2226 additional vectorisation opportunities. 2227 2228 To enable use of this extension on CPUs that implement it, say Y. 2229 2230 On CPUs that support the SVE2 extensions, this option will enable 2231 those too. 2232 2233 Note that for architectural reasons, firmware _must_ implement SVE 2234 support when running on SVE capable hardware. The required support 2235 is present in: 2236 2237 * version 1.5 and later of the ARM Trusted Firmware 2238 * the AArch64 boot wrapper since commit 5e1261e08abf 2239 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2240 2241 For other firmware implementations, consult the firmware documentation 2242 or vendor. 2243 2244 If you need the kernel to boot on SVE-capable hardware with broken 2245 firmware, you may need to say N here until you get your firmware 2246 fixed. Otherwise, you may experience firmware panics or lockups when 2247 booting the kernel. If unsure and you are not observing these 2248 symptoms, you should assume that it is safe to say Y. 2249 2250config ARM64_SME 2251 bool "ARM Scalable Matrix Extension support" 2252 default y 2253 depends on ARM64_SVE 2254 help 2255 The Scalable Matrix Extension (SME) is an extension to the AArch64 2256 execution state which utilises a substantial subset of the SVE 2257 instruction set, together with the addition of new architectural 2258 register state capable of holding two dimensional matrix tiles to 2259 enable various matrix operations. 2260 2261config ARM64_PSEUDO_NMI 2262 bool "Support for NMI-like interrupts" 2263 select ARM_GIC_V3 2264 help 2265 Adds support for mimicking Non-Maskable Interrupts through the use of 2266 GIC interrupt priority. This support requires version 3 or later of 2267 ARM GIC. 2268 2269 This high priority configuration for interrupts needs to be 2270 explicitly enabled by setting the kernel parameter 2271 "irqchip.gicv3_pseudo_nmi" to 1. 2272 2273 If unsure, say N 2274 2275if ARM64_PSEUDO_NMI 2276config ARM64_DEBUG_PRIORITY_MASKING 2277 bool "Debug interrupt priority masking" 2278 help 2279 This adds runtime checks to functions enabling/disabling 2280 interrupts when using priority masking. The additional checks verify 2281 the validity of ICC_PMR_EL1 when calling concerned functions. 2282 2283 If unsure, say N 2284endif # ARM64_PSEUDO_NMI 2285 2286config RELOCATABLE 2287 bool "Build a relocatable kernel image" if EXPERT 2288 select ARCH_HAS_RELR 2289 default y 2290 help 2291 This builds the kernel as a Position Independent Executable (PIE), 2292 which retains all relocation metadata required to relocate the 2293 kernel binary at runtime to a different virtual address than the 2294 address it was linked at. 2295 Since AArch64 uses the RELA relocation format, this requires a 2296 relocation pass at runtime even if the kernel is loaded at the 2297 same address it was linked at. 2298 2299config RANDOMIZE_BASE 2300 bool "Randomize the address of the kernel image" 2301 select RELOCATABLE 2302 help 2303 Randomizes the virtual address at which the kernel image is 2304 loaded, as a security feature that deters exploit attempts 2305 relying on knowledge of the location of kernel internals. 2306 2307 It is the bootloader's job to provide entropy, by passing a 2308 random u64 value in /chosen/kaslr-seed at kernel entry. 2309 2310 When booting via the UEFI stub, it will invoke the firmware's 2311 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2312 to the kernel proper. In addition, it will randomise the physical 2313 location of the kernel Image as well. 2314 2315 If unsure, say N. 2316 2317config RANDOMIZE_MODULE_REGION_FULL 2318 bool "Randomize the module region over a 2 GB range" 2319 depends on RANDOMIZE_BASE 2320 default y 2321 help 2322 Randomizes the location of the module region inside a 2 GB window 2323 covering the core kernel. This way, it is less likely for modules 2324 to leak information about the location of core kernel data structures 2325 but it does imply that function calls between modules and the core 2326 kernel will need to be resolved via veneers in the module PLT. 2327 2328 When this option is not set, the module region will be randomized over 2329 a limited range that contains the [_stext, _etext] interval of the 2330 core kernel, so branch relocations are almost always in range unless 2331 the region is exhausted. In this particular case of region 2332 exhaustion, modules might be able to fall back to a larger 2GB area. 2333 2334config CC_HAVE_STACKPROTECTOR_SYSREG 2335 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2336 2337config STACKPROTECTOR_PER_TASK 2338 def_bool y 2339 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2340 2341config UNWIND_PATCH_PAC_INTO_SCS 2342 bool "Enable shadow call stack dynamically using code patching" 2343 depends on CC_IS_CLANG 2344 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2345 depends on SHADOW_CALL_STACK 2346 select UNWIND_TABLES 2347 select DYNAMIC_SCS 2348 2349config ARM64_CONTPTE 2350 bool "Contiguous PTE mappings for user memory" if EXPERT 2351 depends on TRANSPARENT_HUGEPAGE 2352 default y 2353 help 2354 When enabled, user mappings are configured using the PTE contiguous 2355 bit, for any mappings that meet the size and alignment requirements. 2356 This reduces TLB pressure and improves performance. 2357 2358endmenu # "Kernel Features" 2359 2360menu "Boot options" 2361 2362config ARM64_ACPI_PARKING_PROTOCOL 2363 bool "Enable support for the ARM64 ACPI parking protocol" 2364 depends on ACPI 2365 help 2366 Enable support for the ARM64 ACPI parking protocol. If disabled 2367 the kernel will not allow booting through the ARM64 ACPI parking 2368 protocol even if the corresponding data is present in the ACPI 2369 MADT table. 2370 2371config CMDLINE 2372 string "Default kernel command string" 2373 default "" 2374 help 2375 Provide a set of default command-line options at build time by 2376 entering them here. As a minimum, you should specify the the 2377 root device (e.g. root=/dev/nfs). 2378 2379choice 2380 prompt "Kernel command line type" 2381 depends on CMDLINE != "" 2382 default CMDLINE_FROM_BOOTLOADER 2383 help 2384 Choose how the kernel will handle the provided default kernel 2385 command line string. 2386 2387config CMDLINE_FROM_BOOTLOADER 2388 bool "Use bootloader kernel arguments if available" 2389 help 2390 Uses the command-line options passed by the boot loader. If 2391 the boot loader doesn't provide any, the default kernel command 2392 string provided in CMDLINE will be used. 2393 2394config CMDLINE_FORCE 2395 bool "Always use the default kernel command string" 2396 help 2397 Always use the default kernel command string, even if the boot 2398 loader passes other arguments to the kernel. 2399 This is useful if you cannot or don't want to change the 2400 command-line options your boot loader passes to the kernel. 2401 2402endchoice 2403 2404config EFI_STUB 2405 bool 2406 2407config EFI 2408 bool "UEFI runtime support" 2409 depends on OF && !CPU_BIG_ENDIAN 2410 depends on KERNEL_MODE_NEON 2411 select ARCH_SUPPORTS_ACPI 2412 select LIBFDT 2413 select UCS2_STRING 2414 select EFI_PARAMS_FROM_FDT 2415 select EFI_RUNTIME_WRAPPERS 2416 select EFI_STUB 2417 select EFI_GENERIC_STUB 2418 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2419 default y 2420 help 2421 This option provides support for runtime services provided 2422 by UEFI firmware (such as non-volatile variables, realtime 2423 clock, and platform reset). A UEFI stub is also provided to 2424 allow the kernel to be booted as an EFI application. This 2425 is only useful on systems that have UEFI firmware. 2426 2427config COMPRESSED_INSTALL 2428 bool "Install compressed image by default" 2429 help 2430 This makes the regular "make install" install the compressed 2431 image we built, not the legacy uncompressed one. 2432 2433 You can check that a compressed image works for you by doing 2434 "make zinstall" first, and verifying that everything is fine 2435 in your environment before making "make install" do this for 2436 you. 2437 2438config DMI 2439 bool "Enable support for SMBIOS (DMI) tables" 2440 depends on EFI 2441 default y 2442 help 2443 This enables SMBIOS/DMI feature for systems. 2444 2445 This option is only useful on systems that have UEFI firmware. 2446 However, even with this option, the resultant kernel should 2447 continue to boot on existing non-UEFI platforms. 2448 2449endmenu # "Boot options" 2450 2451menu "Power management options" 2452 2453source "kernel/power/Kconfig" 2454 2455config ARCH_HIBERNATION_POSSIBLE 2456 def_bool y 2457 depends on CPU_PM 2458 2459config ARCH_HIBERNATION_HEADER 2460 def_bool y 2461 depends on HIBERNATION 2462 2463config ARCH_SUSPEND_POSSIBLE 2464 def_bool y 2465 2466endmenu # "Power management options" 2467 2468menu "CPU Power Management" 2469 2470source "drivers/cpuidle/Kconfig" 2471 2472source "drivers/cpufreq/Kconfig" 2473 2474endmenu # "CPU Power Management" 2475 2476source "drivers/acpi/Kconfig" 2477 2478source "arch/arm64/kvm/Kconfig" 2479 2480source "kernel/livepatch/Kconfig" 2481