1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_APMT if ACPI 5 select ACPI_CCA_REQUIRED if ACPI 6 select ACPI_GENERIC_GSI if ACPI 7 select ACPI_GTDT if ACPI 8 select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU 9 select ACPI_IORT if ACPI 10 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 11 select ACPI_MCFG if (ACPI && PCI) 12 select ACPI_SPCR_TABLE if ACPI 13 select ACPI_PPTT if ACPI 14 select ARCH_HAS_DEBUG_WX 15 select ARCH_BINFMT_ELF_EXTRA_PHDRS 16 select ARCH_BINFMT_ELF_STATE 17 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 18 select ARCH_ENABLE_MEMORY_HOTPLUG 19 select ARCH_ENABLE_MEMORY_HOTREMOVE 20 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 21 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 22 select ARCH_HAS_CACHE_LINE_SIZE 23 select ARCH_HAS_CC_PLATFORM 24 select ARCH_HAS_CURRENT_STACK_POINTER 25 select ARCH_HAS_DEBUG_VIRTUAL 26 select ARCH_HAS_DEBUG_VM_PGTABLE 27 select ARCH_HAS_DMA_OPS if XEN 28 select ARCH_HAS_DMA_PREP_COHERENT 29 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 30 select ARCH_HAS_FAST_MULTIPLIER 31 select ARCH_HAS_FORTIFY_SOURCE 32 select ARCH_HAS_GCOV_PROFILE_ALL 33 select ARCH_HAS_GIGANTIC_PAGE 34 select ARCH_HAS_KCOV 35 select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON 36 select ARCH_HAS_KEEPINITRD 37 select ARCH_HAS_MEMBARRIER_SYNC_CORE 38 select ARCH_HAS_MEM_ENCRYPT 39 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 40 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 42 select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT 43 select ARCH_HAS_PREEMPT_LAZY 44 select ARCH_HAS_PTDUMP 45 select ARCH_HAS_PTE_DEVMAP 46 select ARCH_HAS_PTE_SPECIAL 47 select ARCH_HAS_HW_PTE_YOUNG 48 select ARCH_HAS_SETUP_DMA_OPS 49 select ARCH_HAS_SET_DIRECT_MAP 50 select ARCH_HAS_SET_MEMORY 51 select ARCH_HAS_MEM_ENCRYPT 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_CLANG 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_WANT_BATCHED_UNMAP_TLB_FLUSH 113 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 114 select ARCH_WANT_DEFAULT_BPF_JIT 115 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 116 select ARCH_WANT_FRAME_POINTERS 117 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 118 select ARCH_WANT_LD_ORPHAN_WARN 119 select ARCH_WANTS_EXECMEM_LATE 120 select ARCH_WANTS_NO_INSTR 121 select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES 122 select ARCH_HAS_UBSAN 123 select ARM_AMBA 124 select ARM_ARCH_TIMER 125 select ARM_GIC 126 select AUDIT_ARCH_COMPAT_GENERIC 127 select ARM_GIC_V2M if PCI 128 select ARM_GIC_V3 129 select ARM_GIC_V3_ITS if PCI 130 select ARM_PSCI_FW 131 select BUILDTIME_TABLE_SORT 132 select CLONE_BACKWARDS 133 select COMMON_CLK 134 select CPU_PM if (SUSPEND || CPU_IDLE) 135 select CPUMASK_OFFSTACK if NR_CPUS > 256 136 select DCACHE_WORD_ACCESS 137 select DYNAMIC_FTRACE if FUNCTION_TRACER 138 select DMA_BOUNCE_UNALIGNED_KMALLOC 139 select DMA_DIRECT_REMAP 140 select EDAC_SUPPORT 141 select FRAME_POINTER 142 select FUNCTION_ALIGNMENT_4B 143 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 144 select GENERIC_ALLOCATOR 145 select GENERIC_ARCH_TOPOLOGY 146 select GENERIC_CLOCKEVENTS_BROADCAST 147 select GENERIC_CPU_AUTOPROBE 148 select GENERIC_CPU_DEVICES 149 select GENERIC_CPU_VULNERABILITIES 150 select GENERIC_EARLY_IOREMAP 151 select GENERIC_IDLE_POLL_SETUP 152 select GENERIC_IOREMAP 153 select GENERIC_IRQ_IPI 154 select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD 155 select GENERIC_IRQ_PROBE 156 select GENERIC_IRQ_SHOW 157 select GENERIC_IRQ_SHOW_LEVEL 158 select GENERIC_LIB_DEVMEM_IS_ALLOWED 159 select GENERIC_PCI_IOMAP 160 select GENERIC_SCHED_CLOCK 161 select GENERIC_SMP_IDLE_THREAD 162 select GENERIC_TIME_VSYSCALL 163 select GENERIC_GETTIMEOFDAY 164 select GENERIC_VDSO_DATA_STORE 165 select GENERIC_VDSO_TIME_NS 166 select HARDIRQS_SW_RESEND 167 select HAS_IOPORT 168 select HAVE_MOVE_PMD 169 select HAVE_MOVE_PUD 170 select HAVE_PCI 171 select HAVE_ACPI_APEI if (ACPI && EFI) 172 select HAVE_ALIGNED_STRUCT_PAGE 173 select HAVE_ARCH_AUDITSYSCALL 174 select HAVE_ARCH_BITREVERSE 175 select HAVE_ARCH_COMPILER_H 176 select HAVE_ARCH_HUGE_VMALLOC 177 select HAVE_ARCH_HUGE_VMAP 178 select HAVE_ARCH_JUMP_LABEL 179 select HAVE_ARCH_JUMP_LABEL_RELATIVE 180 select HAVE_ARCH_KASAN 181 select HAVE_ARCH_KASAN_VMALLOC 182 select HAVE_ARCH_KASAN_SW_TAGS 183 select HAVE_ARCH_KASAN_HW_TAGS if ARM64_MTE 184 # Some instrumentation may be unsound, hence EXPERT 185 select HAVE_ARCH_KCSAN if EXPERT 186 select HAVE_ARCH_KFENCE 187 select HAVE_ARCH_KGDB 188 select HAVE_ARCH_KSTACK_ERASE 189 select HAVE_ARCH_MMAP_RND_BITS 190 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 191 select HAVE_ARCH_PREL32_RELOCATIONS 192 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 193 select HAVE_ARCH_SECCOMP_FILTER 194 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 195 select HAVE_ARCH_TRACEHOOK 196 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 197 select HAVE_ARCH_VMAP_STACK 198 select HAVE_ARM_SMCCC 199 select HAVE_ASM_MODVERSIONS 200 select HAVE_EBPF_JIT 201 select HAVE_C_RECORDMCOUNT 202 select HAVE_CMPXCHG_DOUBLE 203 select HAVE_CMPXCHG_LOCAL 204 select HAVE_CONTEXT_TRACKING_USER 205 select HAVE_DEBUG_KMEMLEAK 206 select HAVE_DMA_CONTIGUOUS 207 select HAVE_DYNAMIC_FTRACE 208 select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ 209 if (GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS || \ 210 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) 211 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ 212 if DYNAMIC_FTRACE_WITH_ARGS && DYNAMIC_FTRACE_WITH_CALL_OPS 213 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ 214 if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG && \ 215 (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) 216 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 217 if DYNAMIC_FTRACE_WITH_ARGS 218 select HAVE_SAMPLE_FTRACE_DIRECT 219 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 220 select HAVE_BUILDTIME_MCOUNT_SORT 221 select HAVE_EFFICIENT_UNALIGNED_ACCESS 222 select HAVE_GUP_FAST 223 select HAVE_FTRACE_GRAPH_FUNC 224 select HAVE_FTRACE_MCOUNT_RECORD 225 select HAVE_FUNCTION_TRACER 226 select HAVE_FUNCTION_ERROR_INJECTION 227 select HAVE_FUNCTION_GRAPH_FREGS 228 select HAVE_FUNCTION_GRAPH_TRACER 229 select HAVE_GCC_PLUGINS 230 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \ 231 HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI 232 select HAVE_HW_BREAKPOINT if PERF_EVENTS 233 select HAVE_IOREMAP_PROT 234 select HAVE_IRQ_TIME_ACCOUNTING 235 select HAVE_MOD_ARCH_SPECIFIC 236 select HAVE_NMI 237 select HAVE_PERF_EVENTS 238 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI 239 select HAVE_PERF_REGS 240 select HAVE_PERF_USER_STACK_DUMP 241 select HAVE_PREEMPT_DYNAMIC_KEY 242 select HAVE_REGS_AND_STACK_ACCESS_API 243 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 244 select HAVE_FUNCTION_ARG_ACCESS_API 245 select MMU_GATHER_RCU_TABLE_FREE 246 select HAVE_RSEQ 247 select HAVE_RUST if RUSTC_SUPPORTS_ARM64 248 select HAVE_STACKPROTECTOR 249 select HAVE_SYSCALL_TRACEPOINTS 250 select HAVE_KPROBES 251 select HAVE_KRETPROBES 252 select HAVE_GENERIC_VDSO 253 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 254 select HOTPLUG_SMT if HOTPLUG_CPU 255 select IRQ_DOMAIN 256 select IRQ_FORCED_THREADING 257 select JUMP_LABEL 258 select KASAN_VMALLOC if KASAN 259 select LOCK_MM_AND_FIND_VMA 260 select MODULES_USE_ELF_RELA 261 select NEED_DMA_MAP_STATE 262 select NEED_SG_DMA_LENGTH 263 select OF 264 select OF_EARLY_FLATTREE 265 select PCI_DOMAINS_GENERIC if PCI 266 select PCI_ECAM if (ACPI && PCI) 267 select PCI_SYSCALL if PCI 268 select POWER_RESET 269 select POWER_SUPPLY 270 select SPARSE_IRQ 271 select SWIOTLB 272 select SYSCTL_EXCEPTION_TRACE 273 select THREAD_INFO_IN_TASK 274 select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD 275 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 276 select TRACE_IRQFLAGS_SUPPORT 277 select TRACE_IRQFLAGS_NMI_SUPPORT 278 select HAVE_SOFTIRQ_ON_OWN_STACK 279 select USER_STACKTRACE_SUPPORT 280 select VDSO_GETRANDOM 281 help 282 ARM 64-bit (AArch64) Linux support. 283 284config RUSTC_SUPPORTS_ARM64 285 def_bool y 286 depends on CPU_LITTLE_ENDIAN 287 # Shadow call stack is only supported on certain rustc versions. 288 # 289 # When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is 290 # required due to use of the -Zfixed-x18 flag. 291 # 292 # Otherwise, rustc version 1.82+ is required due to use of the 293 # -Zsanitizer=shadow-call-stack flag. 294 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS 295 296config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 297 def_bool CC_IS_CLANG 298 # https://github.com/ClangBuiltLinux/linux/issues/1507 299 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 300 301config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS 302 def_bool CC_IS_GCC 303 depends on $(cc-option,-fpatchable-function-entry=2) 304 305config 64BIT 306 def_bool y 307 308config MMU 309 def_bool y 310 311config ARM64_CONT_PTE_SHIFT 312 int 313 default 5 if PAGE_SIZE_64KB 314 default 7 if PAGE_SIZE_16KB 315 default 4 316 317config ARM64_CONT_PMD_SHIFT 318 int 319 default 5 if PAGE_SIZE_64KB 320 default 5 if PAGE_SIZE_16KB 321 default 4 322 323config ARCH_MMAP_RND_BITS_MIN 324 default 14 if PAGE_SIZE_64KB 325 default 16 if PAGE_SIZE_16KB 326 default 18 327 328# max bits determined by the following formula: 329# VA_BITS - PTDESC_TABLE_SHIFT 330config ARCH_MMAP_RND_BITS_MAX 331 default 19 if ARM64_VA_BITS=36 332 default 24 if ARM64_VA_BITS=39 333 default 27 if ARM64_VA_BITS=42 334 default 30 if ARM64_VA_BITS=47 335 default 29 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES 336 default 31 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES 337 default 33 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) 338 default 14 if ARM64_64K_PAGES 339 default 16 if ARM64_16K_PAGES 340 default 18 341 342config ARCH_MMAP_RND_COMPAT_BITS_MIN 343 default 7 if ARM64_64K_PAGES 344 default 9 if ARM64_16K_PAGES 345 default 11 346 347config ARCH_MMAP_RND_COMPAT_BITS_MAX 348 default 16 349 350config NO_IOPORT_MAP 351 def_bool y if !PCI 352 353config STACKTRACE_SUPPORT 354 def_bool y 355 356config ILLEGAL_POINTER_VALUE 357 hex 358 default 0xdead000000000000 359 360config LOCKDEP_SUPPORT 361 def_bool y 362 363config GENERIC_BUG 364 def_bool y 365 depends on BUG 366 367config GENERIC_BUG_RELATIVE_POINTERS 368 def_bool y 369 depends on GENERIC_BUG 370 371config GENERIC_HWEIGHT 372 def_bool y 373 374config GENERIC_CSUM 375 def_bool y 376 377config GENERIC_CALIBRATE_DELAY 378 def_bool y 379 380config SMP 381 def_bool y 382 383config KERNEL_MODE_NEON 384 def_bool y 385 386config FIX_EARLYCON_MEM 387 def_bool y 388 389config PGTABLE_LEVELS 390 int 391 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 392 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 393 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 394 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 395 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 396 default 4 if ARM64_16K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 397 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 398 default 5 if ARM64_4K_PAGES && ARM64_VA_BITS_52 399 400config ARCH_SUPPORTS_UPROBES 401 def_bool y 402 403config ARCH_PROC_KCORE_TEXT 404 def_bool y 405 406config BROKEN_GAS_INST 407 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 408 409config BUILTIN_RETURN_ADDRESS_STRIPS_PAC 410 bool 411 # Clang's __builtin_return_address() strips the PAC since 12.0.0 412 # https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2 413 default y if CC_IS_CLANG 414 # GCC's __builtin_return_address() strips the PAC since 11.1.0, 415 # and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier 416 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891 417 default y if CC_IS_GCC && (GCC_VERSION >= 110100) 418 default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000) 419 default y if CC_IS_GCC && (GCC_VERSION >= 90400) && (GCC_VERSION < 100000) 420 default y if CC_IS_GCC && (GCC_VERSION >= 80500) && (GCC_VERSION < 90000) 421 default n 422 423config KASAN_SHADOW_OFFSET 424 hex 425 depends on KASAN_GENERIC || KASAN_SW_TAGS 426 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && !KASAN_SW_TAGS 427 default 0xdfffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && !KASAN_SW_TAGS 428 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 429 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 430 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 431 default 0xefff800000000000 if (ARM64_VA_BITS_48 || (ARM64_VA_BITS_52 && !ARM64_16K_PAGES)) && KASAN_SW_TAGS 432 default 0xefffc00000000000 if (ARM64_VA_BITS_47 || ARM64_VA_BITS_52) && ARM64_16K_PAGES && KASAN_SW_TAGS 433 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 434 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 435 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 436 default 0xffffffffffffffff 437 438config UNWIND_TABLES 439 bool 440 441source "arch/arm64/Kconfig.platforms" 442 443menu "Kernel Features" 444 445menu "ARM errata workarounds via the alternatives framework" 446 447config AMPERE_ERRATUM_AC03_CPU_38 448 bool "AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics" 449 default y 450 help 451 This option adds an alternative code sequence to work around Ampere 452 errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne. 453 454 The affected design reports FEAT_HAFDBS as not implemented in 455 ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 456 as required by the architecture. The unadvertised HAFDBS 457 implementation suffers from an additional erratum where hardware 458 A/D updates can occur after a PTE has been marked invalid. 459 460 The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, 461 which avoids enabling unadvertised hardware Access Flag management 462 at stage-2. 463 464 If unsure, say Y. 465 466config AMPERE_ERRATUM_AC04_CPU_23 467 bool "AmpereOne: AC04_CPU_23: Failure to synchronize writes to HCR_EL2 may corrupt address translations." 468 default y 469 help 470 This option adds an alternative code sequence to work around Ampere 471 errata AC04_CPU_23 on AmpereOne. 472 473 Updates to HCR_EL2 can rarely corrupt simultaneous translations for 474 data addresses initiated by load/store instructions. Only 475 instruction initiated translations are vulnerable, not translations 476 from prefetches for example. A DSB before the store to HCR_EL2 is 477 sufficient to prevent older instructions from hitting the window 478 for corruption, and an ISB after is sufficient to prevent younger 479 instructions from hitting the window for corruption. 480 481 If unsure, say Y. 482 483config ARM64_WORKAROUND_CLEAN_CACHE 484 bool 485 486config ARM64_ERRATUM_826319 487 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 488 default y 489 select ARM64_WORKAROUND_CLEAN_CACHE 490 help 491 This option adds an alternative code sequence to work around ARM 492 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 493 AXI master interface and an L2 cache. 494 495 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 496 and is unable to accept a certain write via this interface, it will 497 not progress on read data presented on the read data channel and the 498 system can deadlock. 499 500 The workaround promotes data cache clean instructions to 501 data cache clean-and-invalidate. 502 Please note that this does not necessarily enable the workaround, 503 as it depends on the alternative framework, which will only patch 504 the kernel if an affected CPU is detected. 505 506 If unsure, say Y. 507 508config ARM64_ERRATUM_827319 509 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 510 default y 511 select ARM64_WORKAROUND_CLEAN_CACHE 512 help 513 This option adds an alternative code sequence to work around ARM 514 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 515 master interface and an L2 cache. 516 517 Under certain conditions this erratum can cause a clean line eviction 518 to occur at the same time as another transaction to the same address 519 on the AMBA 5 CHI interface, which can cause data corruption if the 520 interconnect reorders the two transactions. 521 522 The workaround promotes data cache clean instructions to 523 data cache clean-and-invalidate. 524 Please note that this does not necessarily enable the workaround, 525 as it depends on the alternative framework, which will only patch 526 the kernel if an affected CPU is detected. 527 528 If unsure, say Y. 529 530config ARM64_ERRATUM_824069 531 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 532 default y 533 select ARM64_WORKAROUND_CLEAN_CACHE 534 help 535 This option adds an alternative code sequence to work around ARM 536 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 537 to a coherent interconnect. 538 539 If a Cortex-A53 processor is executing a store or prefetch for 540 write instruction at the same time as a processor in another 541 cluster is executing a cache maintenance operation to the same 542 address, then this erratum might cause a clean cache line to be 543 incorrectly marked as dirty. 544 545 The workaround promotes data cache clean instructions to 546 data cache clean-and-invalidate. 547 Please note that this option does not necessarily enable the 548 workaround, as it depends on the alternative framework, which will 549 only patch the kernel if an affected CPU is detected. 550 551 If unsure, say Y. 552 553config ARM64_ERRATUM_819472 554 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 555 default y 556 select ARM64_WORKAROUND_CLEAN_CACHE 557 help 558 This option adds an alternative code sequence to work around ARM 559 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 560 present when it is connected to a coherent interconnect. 561 562 If the processor is executing a load and store exclusive sequence at 563 the same time as a processor in another cluster is executing a cache 564 maintenance operation to the same address, then this erratum might 565 cause data corruption. 566 567 The workaround promotes data cache clean instructions to 568 data cache clean-and-invalidate. 569 Please note that this does not necessarily enable the workaround, 570 as it depends on the alternative framework, which will only patch 571 the kernel if an affected CPU is detected. 572 573 If unsure, say Y. 574 575config ARM64_ERRATUM_832075 576 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 577 default y 578 help 579 This option adds an alternative code sequence to work around ARM 580 erratum 832075 on Cortex-A57 parts up to r1p2. 581 582 Affected Cortex-A57 parts might deadlock when exclusive load/store 583 instructions to Write-Back memory are mixed with Device loads. 584 585 The workaround is to promote device loads to use Load-Acquire 586 semantics. 587 Please note that this does not necessarily enable the workaround, 588 as it depends on the alternative framework, which will only patch 589 the kernel if an affected CPU is detected. 590 591 If unsure, say Y. 592 593config ARM64_ERRATUM_834220 594 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault (rare)" 595 depends on KVM 596 help 597 This option adds an alternative code sequence to work around ARM 598 erratum 834220 on Cortex-A57 parts up to r1p2. 599 600 Affected Cortex-A57 parts might report a Stage 2 translation 601 fault as the result of a Stage 1 fault for load crossing a 602 page boundary when there is a permission or device memory 603 alignment fault at Stage 1 and a translation fault at Stage 2. 604 605 The workaround is to verify that the Stage 1 translation 606 doesn't generate a fault before handling the Stage 2 fault. 607 Please note that this does not necessarily enable the workaround, 608 as it depends on the alternative framework, which will only patch 609 the kernel if an affected CPU is detected. 610 611 If unsure, say N. 612 613config ARM64_ERRATUM_1742098 614 bool "Cortex-A57/A72: 1742098: ELR recorded incorrectly on interrupt taken between cryptographic instructions in a sequence" 615 depends on COMPAT 616 default y 617 help 618 This option removes the AES hwcap for aarch32 user-space to 619 workaround erratum 1742098 on Cortex-A57 and Cortex-A72. 620 621 Affected parts may corrupt the AES state if an interrupt is 622 taken between a pair of AES instructions. These instructions 623 are only present if the cryptography extensions are present. 624 All software should have a fallback implementation for CPUs 625 that don't implement the cryptography extensions. 626 627 If unsure, say Y. 628 629config ARM64_ERRATUM_845719 630 bool "Cortex-A53: 845719: a load might read incorrect data" 631 depends on COMPAT 632 default y 633 help 634 This option adds an alternative code sequence to work around ARM 635 erratum 845719 on Cortex-A53 parts up to r0p4. 636 637 When running a compat (AArch32) userspace on an affected Cortex-A53 638 part, a load at EL0 from a virtual address that matches the bottom 32 639 bits of the virtual address used by a recent load at (AArch64) EL1 640 might return incorrect data. 641 642 The workaround is to write the contextidr_el1 register on exception 643 return to a 32-bit task. 644 Please note that this does not necessarily enable the workaround, 645 as it depends on the alternative framework, which will only patch 646 the kernel if an affected CPU is detected. 647 648 If unsure, say Y. 649 650config ARM64_ERRATUM_843419 651 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 652 default y 653 help 654 This option links the kernel with '--fix-cortex-a53-843419' and 655 enables PLT support to replace certain ADRP instructions, which can 656 cause subsequent memory accesses to use an incorrect address on 657 Cortex-A53 parts up to r0p4. 658 659 If unsure, say Y. 660 661config ARM64_ERRATUM_1024718 662 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 663 default y 664 help 665 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 666 667 Affected Cortex-A55 cores (all revisions) could cause incorrect 668 update of the hardware dirty bit when the DBM/AP bits are updated 669 without a break-before-make. The workaround is to disable the usage 670 of hardware DBM locally on the affected cores. CPUs not affected by 671 this erratum will continue to use the feature. 672 673 If unsure, say Y. 674 675config ARM64_ERRATUM_1418040 676 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 677 default y 678 depends on COMPAT 679 help 680 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 681 errata 1188873 and 1418040. 682 683 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 684 cause register corruption when accessing the timer registers 685 from AArch32 userspace. 686 687 If unsure, say Y. 688 689config ARM64_WORKAROUND_SPECULATIVE_AT 690 bool 691 692config ARM64_ERRATUM_1165522 693 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 694 default y 695 select ARM64_WORKAROUND_SPECULATIVE_AT 696 help 697 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 698 699 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 700 corrupted TLBs by speculating an AT instruction during a guest 701 context switch. 702 703 If unsure, say Y. 704 705config ARM64_ERRATUM_1319367 706 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 707 default y 708 select ARM64_WORKAROUND_SPECULATIVE_AT 709 help 710 This option adds work arounds for ARM Cortex-A57 erratum 1319537 711 and A72 erratum 1319367 712 713 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 714 speculating an AT instruction during a guest context switch. 715 716 If unsure, say Y. 717 718config ARM64_ERRATUM_1530923 719 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 720 default y 721 select ARM64_WORKAROUND_SPECULATIVE_AT 722 help 723 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 724 725 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 726 corrupted TLBs by speculating an AT instruction during a guest 727 context switch. 728 729 If unsure, say Y. 730 731config ARM64_WORKAROUND_REPEAT_TLBI 732 bool 733 734config ARM64_ERRATUM_2441007 735 bool "Cortex-A55: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 736 select ARM64_WORKAROUND_REPEAT_TLBI 737 help 738 This option adds a workaround for ARM Cortex-A55 erratum #2441007. 739 740 Under very rare circumstances, affected Cortex-A55 CPUs 741 may not handle a race between a break-before-make sequence on one 742 CPU, and another CPU accessing the same page. This could allow a 743 store to a page that has been unmapped. 744 745 Work around this by adding the affected CPUs to the list that needs 746 TLB sequences to be done twice. 747 748 If unsure, say N. 749 750config ARM64_ERRATUM_1286807 751 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation (rare)" 752 select ARM64_WORKAROUND_REPEAT_TLBI 753 help 754 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 755 756 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 757 address for a cacheable mapping of a location is being 758 accessed by a core while another core is remapping the virtual 759 address to a new physical page using the recommended 760 break-before-make sequence, then under very rare circumstances 761 TLBI+DSB completes before a read using the translation being 762 invalidated has been observed by other observers. The 763 workaround repeats the TLBI+DSB operation. 764 765 If unsure, say N. 766 767config ARM64_ERRATUM_1463225 768 bool "Cortex-A76: Software Step might prevent interrupt recognition" 769 default y 770 help 771 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 772 773 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 774 of a system call instruction (SVC) can prevent recognition of 775 subsequent interrupts when software stepping is disabled in the 776 exception handler of the system call and either kernel debugging 777 is enabled or VHE is in use. 778 779 Work around the erratum by triggering a dummy step exception 780 when handling a system call from a task that is being stepped 781 in a VHE configuration of the kernel. 782 783 If unsure, say Y. 784 785config ARM64_ERRATUM_1542419 786 bool "Neoverse-N1: workaround mis-ordering of instruction fetches (rare)" 787 help 788 This option adds a workaround for ARM Neoverse-N1 erratum 789 1542419. 790 791 Affected Neoverse-N1 cores could execute a stale instruction when 792 modified by another CPU. The workaround depends on a firmware 793 counterpart. 794 795 Workaround the issue by hiding the DIC feature from EL0. This 796 forces user-space to perform cache maintenance. 797 798 If unsure, say N. 799 800config ARM64_ERRATUM_1508412 801 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 802 default y 803 help 804 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 805 806 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 807 of a store-exclusive or read of PAR_EL1 and a load with device or 808 non-cacheable memory attributes. The workaround depends on a firmware 809 counterpart. 810 811 KVM guests must also have the workaround implemented or they can 812 deadlock the system. 813 814 Work around the issue by inserting DMB SY barriers around PAR_EL1 815 register reads and warning KVM users. The DMB barrier is sufficient 816 to prevent a speculative PAR_EL1 read. 817 818 If unsure, say Y. 819 820config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 821 bool 822 823config ARM64_ERRATUM_2051678 824 bool "Cortex-A510: 2051678: disable Hardware Update of the page table dirty bit" 825 default y 826 help 827 This options adds the workaround for ARM Cortex-A510 erratum ARM64_ERRATUM_2051678. 828 Affected Cortex-A510 might not respect the ordering rules for 829 hardware update of the page table's dirty bit. The workaround 830 is to not enable the feature on affected CPUs. 831 832 If unsure, say Y. 833 834config ARM64_ERRATUM_2077057 835 bool "Cortex-A510: 2077057: workaround software-step corrupting SPSR_EL2" 836 default y 837 help 838 This option adds the workaround for ARM Cortex-A510 erratum 2077057. 839 Affected Cortex-A510 may corrupt SPSR_EL2 when the a step exception is 840 expected, but a Pointer Authentication trap is taken instead. The 841 erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow 842 EL1 to cause a return to EL2 with a guest controlled ELR_EL2. 843 844 This can only happen when EL2 is stepping EL1. 845 846 When these conditions occur, the SPSR_EL2 value is unchanged from the 847 previous guest entry, and can be restored from the in-memory copy. 848 849 If unsure, say Y. 850 851config ARM64_ERRATUM_2658417 852 bool "Cortex-A510: 2658417: remove BF16 support due to incorrect result" 853 default y 854 help 855 This option adds the workaround for ARM Cortex-A510 erratum 2658417. 856 Affected Cortex-A510 (r0p0 to r1p1) may produce the wrong result for 857 BFMMLA or VMMLA instructions in rare circumstances when a pair of 858 A510 CPUs are using shared neon hardware. As the sharing is not 859 discoverable by the kernel, hide the BF16 HWCAP to indicate that 860 user-space should not be using these instructions. 861 862 If unsure, say Y. 863 864config ARM64_ERRATUM_2119858 865 bool "Cortex-A710/X2: 2119858: workaround TRBE overwriting trace data in FILL mode" 866 default y 867 depends on CORESIGHT_TRBE 868 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 869 help 870 This option adds the workaround for ARM Cortex-A710/X2 erratum 2119858. 871 872 Affected Cortex-A710/X2 cores could overwrite up to 3 cache lines of trace 873 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 874 the event of a WRAP event. 875 876 Work around the issue by always making sure we move the TRBPTR_EL1 by 877 256 bytes before enabling the buffer and filling the first 256 bytes of 878 the buffer with ETM ignore packets upon disabling. 879 880 If unsure, say Y. 881 882config ARM64_ERRATUM_2139208 883 bool "Neoverse-N2: 2139208: workaround TRBE overwriting trace data in FILL mode" 884 default y 885 depends on CORESIGHT_TRBE 886 select ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE 887 help 888 This option adds the workaround for ARM Neoverse-N2 erratum 2139208. 889 890 Affected Neoverse-N2 cores could overwrite up to 3 cache lines of trace 891 data at the base of the buffer (pointed to by TRBASER_EL1) in FILL mode in 892 the event of a WRAP event. 893 894 Work around the issue by always making sure we move the TRBPTR_EL1 by 895 256 bytes before enabling the buffer and filling the first 256 bytes of 896 the buffer with ETM ignore packets upon disabling. 897 898 If unsure, say Y. 899 900config ARM64_WORKAROUND_TSB_FLUSH_FAILURE 901 bool 902 903config ARM64_ERRATUM_2054223 904 bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" 905 default y 906 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 907 help 908 Enable workaround for ARM Cortex-A710 erratum 2054223 909 910 Affected cores may fail to flush the trace data on a TSB instruction, when 911 the PE is in trace prohibited state. This will cause losing a few bytes 912 of the trace cached. 913 914 Workaround is to issue two TSB consecutively on affected cores. 915 916 If unsure, say Y. 917 918config ARM64_ERRATUM_2067961 919 bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" 920 default y 921 select ARM64_WORKAROUND_TSB_FLUSH_FAILURE 922 help 923 Enable workaround for ARM Neoverse-N2 erratum 2067961 924 925 Affected cores may fail to flush the trace data on a TSB instruction, when 926 the PE is in trace prohibited state. This will cause losing a few bytes 927 of the trace cached. 928 929 Workaround is to issue two TSB consecutively on affected cores. 930 931 If unsure, say Y. 932 933config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 934 bool 935 936config ARM64_ERRATUM_2253138 937 bool "Neoverse-N2: 2253138: workaround TRBE writing to address out-of-range" 938 depends on CORESIGHT_TRBE 939 default y 940 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 941 help 942 This option adds the workaround for ARM Neoverse-N2 erratum 2253138. 943 944 Affected Neoverse-N2 cores might write to an out-of-range address, not reserved 945 for TRBE. Under some conditions, the TRBE might generate a write to the next 946 virtually addressed page following the last page of the TRBE address space 947 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 948 949 Work around this in the driver by always making sure that there is a 950 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 951 952 If unsure, say Y. 953 954config ARM64_ERRATUM_2224489 955 bool "Cortex-A710/X2: 2224489: workaround TRBE writing to address out-of-range" 956 depends on CORESIGHT_TRBE 957 default y 958 select ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE 959 help 960 This option adds the workaround for ARM Cortex-A710/X2 erratum 2224489. 961 962 Affected Cortex-A710/X2 cores might write to an out-of-range address, not reserved 963 for TRBE. Under some conditions, the TRBE might generate a write to the next 964 virtually addressed page following the last page of the TRBE address space 965 (i.e., the TRBLIMITR_EL1.LIMIT), instead of wrapping around to the base. 966 967 Work around this in the driver by always making sure that there is a 968 page beyond the TRBLIMITR_EL1.LIMIT, within the space allowed for the TRBE. 969 970 If unsure, say Y. 971 972config ARM64_ERRATUM_2441009 973 bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI (rare)" 974 select ARM64_WORKAROUND_REPEAT_TLBI 975 help 976 This option adds a workaround for ARM Cortex-A510 erratum #2441009. 977 978 Under very rare circumstances, affected Cortex-A510 CPUs 979 may not handle a race between a break-before-make sequence on one 980 CPU, and another CPU accessing the same page. This could allow a 981 store to a page that has been unmapped. 982 983 Work around this by adding the affected CPUs to the list that needs 984 TLB sequences to be done twice. 985 986 If unsure, say N. 987 988config ARM64_ERRATUM_2064142 989 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" 990 depends on CORESIGHT_TRBE 991 default y 992 help 993 This option adds the workaround for ARM Cortex-A510 erratum 2064142. 994 995 Affected Cortex-A510 core might fail to write into system registers after the 996 TRBE has been disabled. Under some conditions after the TRBE has been disabled 997 writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, 998 and TRBTRG_EL1 will be ignored and will not be effected. 999 1000 Work around this in the driver by executing TSB CSYNC and DSB after collection 1001 is stopped and before performing a system register write to one of the affected 1002 registers. 1003 1004 If unsure, say Y. 1005 1006config ARM64_ERRATUM_2038923 1007 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" 1008 depends on CORESIGHT_TRBE 1009 default y 1010 help 1011 This option adds the workaround for ARM Cortex-A510 erratum 2038923. 1012 1013 Affected Cortex-A510 core might cause an inconsistent view on whether trace is 1014 prohibited within the CPU. As a result, the trace buffer or trace buffer state 1015 might be corrupted. This happens after TRBE buffer has been enabled by setting 1016 TRBLIMITR_EL1.E, followed by just a single context synchronization event before 1017 execution changes from a context, in which trace is prohibited to one where it 1018 isn't, or vice versa. In these mentioned conditions, the view of whether trace 1019 is prohibited is inconsistent between parts of the CPU, and the trace buffer or 1020 the trace buffer state might be corrupted. 1021 1022 Work around this in the driver by preventing an inconsistent view of whether the 1023 trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a 1024 change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or 1025 two ISB instructions if no ERET is to take place. 1026 1027 If unsure, say Y. 1028 1029config ARM64_ERRATUM_1902691 1030 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" 1031 depends on CORESIGHT_TRBE 1032 default y 1033 help 1034 This option adds the workaround for ARM Cortex-A510 erratum 1902691. 1035 1036 Affected Cortex-A510 core might cause trace data corruption, when being written 1037 into the memory. Effectively TRBE is broken and hence cannot be used to capture 1038 trace data. 1039 1040 Work around this problem in the driver by just preventing TRBE initialization on 1041 affected cpus. The firmware must have disabled the access to TRBE for the kernel 1042 on such implementations. This will cover the kernel for any firmware that doesn't 1043 do this already. 1044 1045 If unsure, say Y. 1046 1047config ARM64_ERRATUM_2457168 1048 bool "Cortex-A510: 2457168: workaround for AMEVCNTR01 incrementing incorrectly" 1049 depends on ARM64_AMU_EXTN 1050 default y 1051 help 1052 This option adds the workaround for ARM Cortex-A510 erratum 2457168. 1053 1054 The AMU counter AMEVCNTR01 (constant counter) should increment at the same rate 1055 as the system counter. On affected Cortex-A510 cores AMEVCNTR01 increments 1056 incorrectly giving a significantly higher output value. 1057 1058 Work around this problem by returning 0 when reading the affected counter in 1059 key locations that results in disabling all users of this counter. This effect 1060 is the same to firmware disabling affected counters. 1061 1062 If unsure, say Y. 1063 1064config ARM64_ERRATUM_2645198 1065 bool "Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption" 1066 default y 1067 help 1068 This option adds the workaround for ARM Cortex-A715 erratum 2645198. 1069 1070 If a Cortex-A715 cpu sees a page mapping permissions change from executable 1071 to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the 1072 next instruction abort caused by permission fault. 1073 1074 Only user-space does executable to non-executable permission transition via 1075 mprotect() system call. Workaround the problem by doing a break-before-make 1076 TLB invalidation, for all changes to executable user space mappings. 1077 1078 If unsure, say Y. 1079 1080config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1081 bool 1082 1083config ARM64_ERRATUM_2966298 1084 bool "Cortex-A520: 2966298: workaround for speculatively executed unprivileged load" 1085 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1086 default y 1087 help 1088 This option adds the workaround for ARM Cortex-A520 erratum 2966298. 1089 1090 On an affected Cortex-A520 core, a speculatively executed unprivileged 1091 load might leak data from a privileged level via a cache side channel. 1092 1093 Work around this problem by executing a TLBI before returning to EL0. 1094 1095 If unsure, say Y. 1096 1097config ARM64_ERRATUM_3117295 1098 bool "Cortex-A510: 3117295: workaround for speculatively executed unprivileged load" 1099 select ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 1100 default y 1101 help 1102 This option adds the workaround for ARM Cortex-A510 erratum 3117295. 1103 1104 On an affected Cortex-A510 core, a speculatively executed unprivileged 1105 load might leak data from a privileged level via a cache side channel. 1106 1107 Work around this problem by executing a TLBI before returning to EL0. 1108 1109 If unsure, say Y. 1110 1111config ARM64_ERRATUM_3194386 1112 bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing" 1113 default y 1114 help 1115 This option adds the workaround for the following errata: 1116 1117 * ARM Cortex-A76 erratum 3324349 1118 * ARM Cortex-A77 erratum 3324348 1119 * ARM Cortex-A78 erratum 3324344 1120 * ARM Cortex-A78C erratum 3324346 1121 * ARM Cortex-A78C erratum 3324347 1122 * ARM Cortex-A710 erratam 3324338 1123 * ARM Cortex-A715 errartum 3456084 1124 * ARM Cortex-A720 erratum 3456091 1125 * ARM Cortex-A725 erratum 3456106 1126 * ARM Cortex-X1 erratum 3324344 1127 * ARM Cortex-X1C erratum 3324346 1128 * ARM Cortex-X2 erratum 3324338 1129 * ARM Cortex-X3 erratum 3324335 1130 * ARM Cortex-X4 erratum 3194386 1131 * ARM Cortex-X925 erratum 3324334 1132 * ARM Neoverse-N1 erratum 3324349 1133 * ARM Neoverse N2 erratum 3324339 1134 * ARM Neoverse-N3 erratum 3456111 1135 * ARM Neoverse-V1 erratum 3324341 1136 * ARM Neoverse V2 erratum 3324336 1137 * ARM Neoverse-V3 erratum 3312417 1138 1139 On affected cores "MSR SSBS, #0" instructions may not affect 1140 subsequent speculative instructions, which may permit unexepected 1141 speculative store bypassing. 1142 1143 Work around this problem by placing a Speculation Barrier (SB) or 1144 Instruction Synchronization Barrier (ISB) after kernel changes to 1145 SSBS. The presence of the SSBS special-purpose register is hidden 1146 from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace 1147 will use the PR_SPEC_STORE_BYPASS prctl to change SSBS. 1148 1149 If unsure, say Y. 1150 1151config CAVIUM_ERRATUM_22375 1152 bool "Cavium erratum 22375, 24313" 1153 default y 1154 help 1155 Enable workaround for errata 22375 and 24313. 1156 1157 This implements two gicv3-its errata workarounds for ThunderX. Both 1158 with a small impact affecting only ITS table allocation. 1159 1160 erratum 22375: only alloc 8MB table size 1161 erratum 24313: ignore memory access type 1162 1163 The fixes are in ITS initialization and basically ignore memory access 1164 type and table size provided by the TYPER and BASER registers. 1165 1166 If unsure, say Y. 1167 1168config CAVIUM_ERRATUM_23144 1169 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 1170 depends on NUMA 1171 default y 1172 help 1173 ITS SYNC command hang for cross node io and collections/cpu mapping. 1174 1175 If unsure, say Y. 1176 1177config CAVIUM_ERRATUM_23154 1178 bool "Cavium errata 23154 and 38545: GICv3 lacks HW synchronisation" 1179 default y 1180 help 1181 The ThunderX GICv3 implementation requires a modified version for 1182 reading the IAR status to ensure data synchronization 1183 (access to icc_iar1_el1 is not sync'ed before and after). 1184 1185 It also suffers from erratum 38545 (also present on Marvell's 1186 OcteonTX and OcteonTX2), resulting in deactivated interrupts being 1187 spuriously presented to the CPU interface. 1188 1189 If unsure, say Y. 1190 1191config CAVIUM_ERRATUM_27456 1192 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 1193 default y 1194 help 1195 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 1196 instructions may cause the icache to become corrupted if it 1197 contains data for a non-current ASID. The fix is to 1198 invalidate the icache when changing the mm context. 1199 1200 If unsure, say Y. 1201 1202config CAVIUM_ERRATUM_30115 1203 bool "Cavium erratum 30115: Guest may disable interrupts in host" 1204 default y 1205 help 1206 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 1207 1.2, and T83 Pass 1.0, KVM guest execution may disable 1208 interrupts in host. Trapping both GICv3 group-0 and group-1 1209 accesses sidesteps the issue. 1210 1211 If unsure, say Y. 1212 1213config CAVIUM_TX2_ERRATUM_219 1214 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 1215 default y 1216 help 1217 On Cavium ThunderX2, a load, store or prefetch instruction between a 1218 TTBR update and the corresponding context synchronizing operation can 1219 cause a spurious Data Abort to be delivered to any hardware thread in 1220 the CPU core. 1221 1222 Work around the issue by avoiding the problematic code sequence and 1223 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 1224 trap handler performs the corresponding register access, skips the 1225 instruction and ensures context synchronization by virtue of the 1226 exception return. 1227 1228 If unsure, say Y. 1229 1230config FUJITSU_ERRATUM_010001 1231 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 1232 default y 1233 help 1234 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 1235 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 1236 accesses may cause undefined fault (Data abort, DFSC=0b111111). 1237 This fault occurs under a specific hardware condition when a 1238 load/store instruction performs an address translation using: 1239 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 1240 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 1241 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 1242 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 1243 1244 The workaround is to ensure these bits are clear in TCR_ELx. 1245 The workaround only affects the Fujitsu-A64FX. 1246 1247 If unsure, say Y. 1248 1249config HISILICON_ERRATUM_161600802 1250 bool "Hip07 161600802: Erroneous redistributor VLPI base" 1251 default y 1252 help 1253 The HiSilicon Hip07 SoC uses the wrong redistributor base 1254 when issued ITS commands such as VMOVP and VMAPP, and requires 1255 a 128kB offset to be applied to the target address in this commands. 1256 1257 If unsure, say Y. 1258 1259config HISILICON_ERRATUM_162100801 1260 bool "Hip09 162100801 erratum support" 1261 default y 1262 help 1263 When enabling GICv4.1 in hip09, VMAPP will fail to clear some caches 1264 during unmapping operation, which will cause some vSGIs lost. 1265 To fix the issue, invalidate related vPE cache through GICR_INVALLR 1266 after VMOVP. 1267 1268 If unsure, say Y. 1269 1270config QCOM_FALKOR_ERRATUM_1003 1271 bool "Falkor E1003: Incorrect translation due to ASID change" 1272 default y 1273 help 1274 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 1275 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 1276 in TTBR1_EL1, this situation only occurs in the entry trampoline and 1277 then only for entries in the walk cache, since the leaf translation 1278 is unchanged. Work around the erratum by invalidating the walk cache 1279 entries for the trampoline before entering the kernel proper. 1280 1281config QCOM_FALKOR_ERRATUM_1009 1282 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 1283 default y 1284 select ARM64_WORKAROUND_REPEAT_TLBI 1285 help 1286 On Falkor v1, the CPU may prematurely complete a DSB following a 1287 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 1288 one more time to fix the issue. 1289 1290 If unsure, say Y. 1291 1292config QCOM_QDF2400_ERRATUM_0065 1293 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 1294 default y 1295 help 1296 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 1297 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 1298 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 1299 1300 If unsure, say Y. 1301 1302config QCOM_FALKOR_ERRATUM_E1041 1303 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 1304 default y 1305 help 1306 Falkor CPU may speculatively fetch instructions from an improper 1307 memory location when MMU translation is changed from SCTLR_ELn[M]=1 1308 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 1309 1310 If unsure, say Y. 1311 1312config NVIDIA_CARMEL_CNP_ERRATUM 1313 bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores" 1314 default y 1315 help 1316 If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not 1317 invalidate shared TLB entries installed by a different core, as it would 1318 on standard ARM cores. 1319 1320 If unsure, say Y. 1321 1322config ROCKCHIP_ERRATUM_3568002 1323 bool "Rockchip 3568002: GIC600 can not access physical addresses higher than 4GB" 1324 default y 1325 help 1326 The Rockchip RK3566 and RK3568 GIC600 SoC integrations have AXI 1327 addressing limited to the first 32bit of physical address space. 1328 1329 If unsure, say Y. 1330 1331config ROCKCHIP_ERRATUM_3588001 1332 bool "Rockchip 3588001: GIC600 can not support shareability attributes" 1333 default y 1334 help 1335 The Rockchip RK3588 GIC600 SoC integration does not support ACE/ACE-lite. 1336 This means, that its sharability feature may not be used, even though it 1337 is supported by the IP itself. 1338 1339 If unsure, say Y. 1340 1341config SOCIONEXT_SYNQUACER_PREITS 1342 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 1343 default y 1344 help 1345 Socionext Synquacer SoCs implement a separate h/w block to generate 1346 MSI doorbell writes with non-zero values for the device ID. 1347 1348 If unsure, say Y. 1349 1350endmenu # "ARM errata workarounds via the alternatives framework" 1351 1352choice 1353 prompt "Page size" 1354 default ARM64_4K_PAGES 1355 help 1356 Page size (translation granule) configuration. 1357 1358config ARM64_4K_PAGES 1359 bool "4KB" 1360 select HAVE_PAGE_SIZE_4KB 1361 help 1362 This feature enables 4KB pages support. 1363 1364config ARM64_16K_PAGES 1365 bool "16KB" 1366 select HAVE_PAGE_SIZE_16KB 1367 help 1368 The system will use 16KB pages support. AArch32 emulation 1369 requires applications compiled with 16K (or a multiple of 16K) 1370 aligned segments. 1371 1372config ARM64_64K_PAGES 1373 bool "64KB" 1374 select HAVE_PAGE_SIZE_64KB 1375 help 1376 This feature enables 64KB pages support (4KB by default) 1377 allowing only two levels of page tables and faster TLB 1378 look-up. AArch32 emulation requires applications compiled 1379 with 64K aligned segments. 1380 1381endchoice 1382 1383choice 1384 prompt "Virtual address space size" 1385 default ARM64_VA_BITS_52 1386 help 1387 Allows choosing one of multiple possible virtual address 1388 space sizes. The level of translation table is determined by 1389 a combination of page size and virtual address space size. 1390 1391config ARM64_VA_BITS_36 1392 bool "36-bit" if EXPERT 1393 depends on PAGE_SIZE_16KB 1394 1395config ARM64_VA_BITS_39 1396 bool "39-bit" 1397 depends on PAGE_SIZE_4KB 1398 1399config ARM64_VA_BITS_42 1400 bool "42-bit" 1401 depends on PAGE_SIZE_64KB 1402 1403config ARM64_VA_BITS_47 1404 bool "47-bit" 1405 depends on PAGE_SIZE_16KB 1406 1407config ARM64_VA_BITS_48 1408 bool "48-bit" 1409 1410config ARM64_VA_BITS_52 1411 bool "52-bit" 1412 help 1413 Enable 52-bit virtual addressing for userspace when explicitly 1414 requested via a hint to mmap(). The kernel will also use 52-bit 1415 virtual addresses for its own mappings (provided HW support for 1416 this feature is available, otherwise it reverts to 48-bit). 1417 1418 NOTE: Enabling 52-bit virtual addressing in conjunction with 1419 ARMv8.3 Pointer Authentication will result in the PAC being 1420 reduced from 7 bits to 3 bits, which may have a significant 1421 impact on its susceptibility to brute-force attacks. 1422 1423 If unsure, select 48-bit virtual addressing instead. 1424 1425endchoice 1426 1427config ARM64_FORCE_52BIT 1428 bool "Force 52-bit virtual addresses for userspace" 1429 depends on ARM64_VA_BITS_52 && EXPERT 1430 help 1431 For systems with 52-bit userspace VAs enabled, the kernel will attempt 1432 to maintain compatibility with older software by providing 48-bit VAs 1433 unless a hint is supplied to mmap. 1434 1435 This configuration option disables the 48-bit compatibility logic, and 1436 forces all userspace addresses to be 52-bit on HW that supports it. One 1437 should only enable this configuration option for stress testing userspace 1438 memory management code. If unsure say N here. 1439 1440config ARM64_VA_BITS 1441 int 1442 default 36 if ARM64_VA_BITS_36 1443 default 39 if ARM64_VA_BITS_39 1444 default 42 if ARM64_VA_BITS_42 1445 default 47 if ARM64_VA_BITS_47 1446 default 48 if ARM64_VA_BITS_48 1447 default 52 if ARM64_VA_BITS_52 1448 1449choice 1450 prompt "Physical address space size" 1451 default ARM64_PA_BITS_48 1452 help 1453 Choose the maximum physical address range that the kernel will 1454 support. 1455 1456config ARM64_PA_BITS_48 1457 bool "48-bit" 1458 depends on ARM64_64K_PAGES || !ARM64_VA_BITS_52 1459 1460config ARM64_PA_BITS_52 1461 bool "52-bit" 1462 depends on ARM64_64K_PAGES || ARM64_VA_BITS_52 1463 help 1464 Enable support for a 52-bit physical address space, introduced as 1465 part of the ARMv8.2-LPA extension. 1466 1467 With this enabled, the kernel will also continue to work on CPUs that 1468 do not support ARMv8.2-LPA, but with some added memory overhead (and 1469 minor performance overhead). 1470 1471endchoice 1472 1473config ARM64_PA_BITS 1474 int 1475 default 48 if ARM64_PA_BITS_48 1476 default 52 if ARM64_PA_BITS_52 1477 1478config ARM64_LPA2 1479 def_bool y 1480 depends on ARM64_PA_BITS_52 && !ARM64_64K_PAGES 1481 1482choice 1483 prompt "Endianness" 1484 default CPU_LITTLE_ENDIAN 1485 help 1486 Select the endianness of data accesses performed by the CPU. Userspace 1487 applications will need to be compiled and linked for the endianness 1488 that is selected here. 1489 1490config CPU_BIG_ENDIAN 1491 bool "Build big-endian kernel" 1492 # https://github.com/llvm/llvm-project/commit/1379b150991f70a5782e9a143c2ba5308da1161c 1493 depends on AS_IS_GNU || AS_VERSION >= 150000 1494 help 1495 Say Y if you plan on running a kernel with a big-endian userspace. 1496 1497config CPU_LITTLE_ENDIAN 1498 bool "Build little-endian kernel" 1499 help 1500 Say Y if you plan on running a kernel with a little-endian userspace. 1501 This is usually the case for distributions targeting arm64. 1502 1503endchoice 1504 1505config SCHED_MC 1506 bool "Multi-core scheduler support" 1507 help 1508 Multi-core scheduler support improves the CPU scheduler's decision 1509 making when dealing with multi-core CPU chips at a cost of slightly 1510 increased overhead in some places. If unsure say N here. 1511 1512config SCHED_CLUSTER 1513 bool "Cluster scheduler support" 1514 help 1515 Cluster scheduler support improves the CPU scheduler's decision 1516 making when dealing with machines that have clusters of CPUs. 1517 Cluster usually means a couple of CPUs which are placed closely 1518 by sharing mid-level caches, last-level cache tags or internal 1519 busses. 1520 1521config SCHED_SMT 1522 bool "SMT scheduler support" 1523 help 1524 Improves the CPU scheduler's decision making when dealing with 1525 MultiThreading at a cost of slightly increased overhead in some 1526 places. If unsure say N here. 1527 1528config NR_CPUS 1529 int "Maximum number of CPUs (2-4096)" 1530 range 2 4096 1531 default "512" 1532 1533config HOTPLUG_CPU 1534 bool "Support for hot-pluggable CPUs" 1535 select GENERIC_IRQ_MIGRATION 1536 help 1537 Say Y here to experiment with turning CPUs off and on. CPUs 1538 can be controlled through /sys/devices/system/cpu. 1539 1540# Common NUMA Features 1541config NUMA 1542 bool "NUMA Memory Allocation and Scheduler Support" 1543 select GENERIC_ARCH_NUMA 1544 select OF_NUMA 1545 select HAVE_SETUP_PER_CPU_AREA 1546 select NEED_PER_CPU_EMBED_FIRST_CHUNK 1547 select NEED_PER_CPU_PAGE_FIRST_CHUNK 1548 select USE_PERCPU_NUMA_NODE_ID 1549 help 1550 Enable NUMA (Non-Uniform Memory Access) support. 1551 1552 The kernel will try to allocate memory used by a CPU on the 1553 local memory of the CPU and add some more 1554 NUMA awareness to the kernel. 1555 1556config NODES_SHIFT 1557 int "Maximum NUMA Nodes (as a power of 2)" 1558 range 1 10 1559 default "4" 1560 depends on NUMA 1561 help 1562 Specify the maximum number of NUMA Nodes available on the target 1563 system. Increases memory reserved to accommodate various tables. 1564 1565source "kernel/Kconfig.hz" 1566 1567config ARCH_SPARSEMEM_ENABLE 1568 def_bool y 1569 select SPARSEMEM_VMEMMAP_ENABLE 1570 select SPARSEMEM_VMEMMAP 1571 1572config HW_PERF_EVENTS 1573 def_bool y 1574 depends on ARM_PMU 1575 1576# Supported by clang >= 7.0 or GCC >= 12.0.0 1577config CC_HAVE_SHADOW_CALL_STACK 1578 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1579 1580config PARAVIRT 1581 bool "Enable paravirtualization code" 1582 help 1583 This changes the kernel so it can modify itself when it is run 1584 under a hypervisor, potentially improving performance significantly 1585 over full virtualization. 1586 1587config PARAVIRT_TIME_ACCOUNTING 1588 bool "Paravirtual steal time accounting" 1589 select PARAVIRT 1590 help 1591 Select this option to enable fine granularity task steal time 1592 accounting. Time spent executing other tasks in parallel with 1593 the current vCPU is discounted from the vCPU power. To account for 1594 that, there can be a small performance impact. 1595 1596 If in doubt, say N here. 1597 1598config ARCH_SUPPORTS_KEXEC 1599 def_bool PM_SLEEP_SMP 1600 1601config ARCH_SUPPORTS_KEXEC_FILE 1602 def_bool y 1603 1604config ARCH_SELECTS_KEXEC_FILE 1605 def_bool y 1606 depends on KEXEC_FILE 1607 select HAVE_IMA_KEXEC if IMA 1608 1609config ARCH_SUPPORTS_KEXEC_SIG 1610 def_bool y 1611 1612config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG 1613 def_bool y 1614 1615config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG 1616 def_bool y 1617 1618config ARCH_SUPPORTS_KEXEC_HANDOVER 1619 def_bool y 1620 1621config ARCH_SUPPORTS_CRASH_DUMP 1622 def_bool y 1623 1624config ARCH_DEFAULT_CRASH_DUMP 1625 def_bool y 1626 1627config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1628 def_bool CRASH_RESERVE 1629 1630config TRANS_TABLE 1631 def_bool y 1632 depends on HIBERNATION || KEXEC_CORE 1633 1634config XEN_DOM0 1635 def_bool y 1636 depends on XEN 1637 1638config XEN 1639 bool "Xen guest support on ARM64" 1640 depends on ARM64 && OF 1641 select SWIOTLB_XEN 1642 select PARAVIRT 1643 help 1644 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1645 1646# include/linux/mmzone.h requires the following to be true: 1647# 1648# MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1649# 1650# so the maximum value of MAX_PAGE_ORDER is SECTION_SIZE_BITS - PAGE_SHIFT: 1651# 1652# | SECTION_SIZE_BITS | PAGE_SHIFT | max MAX_PAGE_ORDER | default MAX_PAGE_ORDER | 1653# ----+-------------------+--------------+----------------------+-------------------------+ 1654# 4K | 27 | 12 | 15 | 10 | 1655# 16K | 27 | 14 | 13 | 11 | 1656# 64K | 29 | 16 | 13 | 13 | 1657config ARCH_FORCE_MAX_ORDER 1658 int 1659 default "13" if ARM64_64K_PAGES 1660 default "11" if ARM64_16K_PAGES 1661 default "10" 1662 help 1663 The kernel page allocator limits the size of maximal physically 1664 contiguous allocations. The limit is called MAX_PAGE_ORDER and it 1665 defines the maximal power of two of number of pages that can be 1666 allocated as a single contiguous block. This option allows 1667 overriding the default setting when ability to allocate very 1668 large blocks of physically contiguous memory is required. 1669 1670 The maximal size of allocation cannot exceed the size of the 1671 section, so the value of MAX_PAGE_ORDER should satisfy 1672 1673 MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS 1674 1675 Don't change if unsure. 1676 1677config UNMAP_KERNEL_AT_EL0 1678 bool "Unmap kernel when running in userspace (KPTI)" if EXPERT 1679 default y 1680 help 1681 Speculation attacks against some high-performance processors can 1682 be used to bypass MMU permission checks and leak kernel data to 1683 userspace. This can be defended against by unmapping the kernel 1684 when running in userspace, mapping it back in on exception entry 1685 via a trampoline page in the vector table. 1686 1687 If unsure, say Y. 1688 1689config MITIGATE_SPECTRE_BRANCH_HISTORY 1690 bool "Mitigate Spectre style attacks against branch history" if EXPERT 1691 default y 1692 help 1693 Speculation attacks against some high-performance processors can 1694 make use of branch history to influence future speculation. 1695 When taking an exception from user-space, a sequence of branches 1696 or a firmware call overwrites the branch history. 1697 1698config RODATA_FULL_DEFAULT_ENABLED 1699 bool "Apply r/o permissions of VM areas also to their linear aliases" 1700 default y 1701 help 1702 Apply read-only attributes of VM areas to the linear alias of 1703 the backing pages as well. This prevents code or read-only data 1704 from being modified (inadvertently or intentionally) via another 1705 mapping of the same memory page. This additional enhancement can 1706 be turned off at runtime by passing rodata=[off|on] (and turned on 1707 with rodata=full if this option is set to 'n') 1708 1709 This requires the linear region to be mapped down to pages, 1710 which may adversely affect performance in some cases. 1711 1712config ARM64_SW_TTBR0_PAN 1713 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1714 depends on !KCSAN 1715 select ARM64_PAN 1716 help 1717 Enabling this option prevents the kernel from accessing 1718 user-space memory directly by pointing TTBR0_EL1 to a reserved 1719 zeroed area and reserved ASID. The user access routines 1720 restore the valid TTBR0_EL1 temporarily. 1721 1722config ARM64_TAGGED_ADDR_ABI 1723 bool "Enable the tagged user addresses syscall ABI" 1724 default y 1725 help 1726 When this option is enabled, user applications can opt in to a 1727 relaxed ABI via prctl() allowing tagged addresses to be passed 1728 to system calls as pointer arguments. For details, see 1729 Documentation/arch/arm64/tagged-address-abi.rst. 1730 1731menuconfig COMPAT 1732 bool "Kernel support for 32-bit EL0" 1733 depends on ARM64_4K_PAGES || EXPERT 1734 select HAVE_UID16 1735 select OLD_SIGSUSPEND3 1736 select COMPAT_OLD_SIGACTION 1737 help 1738 This option enables support for a 32-bit EL0 running under a 64-bit 1739 kernel at EL1. AArch32-specific components such as system calls, 1740 the user helper functions, VFP support and the ptrace interface are 1741 handled appropriately by the kernel. 1742 1743 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1744 that you will only be able to execute AArch32 binaries that were compiled 1745 with page size aligned segments. 1746 1747 If you want to execute 32-bit userspace applications, say Y. 1748 1749if COMPAT 1750 1751config KUSER_HELPERS 1752 bool "Enable kuser helpers page for 32-bit applications" 1753 default y 1754 help 1755 Warning: disabling this option may break 32-bit user programs. 1756 1757 Provide kuser helpers to compat tasks. The kernel provides 1758 helper code to userspace in read only form at a fixed location 1759 to allow userspace to be independent of the CPU type fitted to 1760 the system. This permits binaries to be run on ARMv4 through 1761 to ARMv8 without modification. 1762 1763 See Documentation/arch/arm/kernel_user_helpers.rst for details. 1764 1765 However, the fixed address nature of these helpers can be used 1766 by ROP (return orientated programming) authors when creating 1767 exploits. 1768 1769 If all of the binaries and libraries which run on your platform 1770 are built specifically for your platform, and make no use of 1771 these helpers, then you can turn this option off to hinder 1772 such exploits. However, in that case, if a binary or library 1773 relying on those helpers is run, it will not function correctly. 1774 1775 Say N here only if you are absolutely certain that you do not 1776 need these helpers; otherwise, the safe option is to say Y. 1777 1778config COMPAT_VDSO 1779 bool "Enable vDSO for 32-bit applications" 1780 depends on !CPU_BIG_ENDIAN 1781 depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" 1782 select GENERIC_COMPAT_VDSO 1783 default y 1784 help 1785 Place in the process address space of 32-bit applications an 1786 ELF shared object providing fast implementations of gettimeofday 1787 and clock_gettime. 1788 1789 You must have a 32-bit build of glibc 2.22 or later for programs 1790 to seamlessly take advantage of this. 1791 1792config THUMB2_COMPAT_VDSO 1793 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1794 depends on COMPAT_VDSO 1795 default y 1796 help 1797 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1798 otherwise with '-marm'. 1799 1800config COMPAT_ALIGNMENT_FIXUPS 1801 bool "Fix up misaligned multi-word loads and stores in user space" 1802 1803menuconfig ARMV8_DEPRECATED 1804 bool "Emulate deprecated/obsolete ARMv8 instructions" 1805 depends on SYSCTL 1806 help 1807 Legacy software support may require certain instructions 1808 that have been deprecated or obsoleted in the architecture. 1809 1810 Enable this config to enable selective emulation of these 1811 features. 1812 1813 If unsure, say Y 1814 1815if ARMV8_DEPRECATED 1816 1817config SWP_EMULATION 1818 bool "Emulate SWP/SWPB instructions" 1819 help 1820 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1821 they are always undefined. Say Y here to enable software 1822 emulation of these instructions for userspace using LDXR/STXR. 1823 This feature can be controlled at runtime with the abi.swp 1824 sysctl which is disabled by default. 1825 1826 In some older versions of glibc [<=2.8] SWP is used during futex 1827 trylock() operations with the assumption that the code will not 1828 be preempted. This invalid assumption may be more likely to fail 1829 with SWP emulation enabled, leading to deadlock of the user 1830 application. 1831 1832 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1833 on an external transaction monitoring block called a global 1834 monitor to maintain update atomicity. If your system does not 1835 implement a global monitor, this option can cause programs that 1836 perform SWP operations to uncached memory to deadlock. 1837 1838 If unsure, say Y 1839 1840config CP15_BARRIER_EMULATION 1841 bool "Emulate CP15 Barrier instructions" 1842 help 1843 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1844 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1845 strongly recommended to use the ISB, DSB, and DMB 1846 instructions instead. 1847 1848 Say Y here to enable software emulation of these 1849 instructions for AArch32 userspace code. When this option is 1850 enabled, CP15 barrier usage is traced which can help 1851 identify software that needs updating. This feature can be 1852 controlled at runtime with the abi.cp15_barrier sysctl. 1853 1854 If unsure, say Y 1855 1856config SETEND_EMULATION 1857 bool "Emulate SETEND instruction" 1858 help 1859 The SETEND instruction alters the data-endianness of the 1860 AArch32 EL0, and is deprecated in ARMv8. 1861 1862 Say Y here to enable software emulation of the instruction 1863 for AArch32 userspace code. This feature can be controlled 1864 at runtime with the abi.setend sysctl. 1865 1866 Note: All the cpus on the system must have mixed endian support at EL0 1867 for this feature to be enabled. If a new CPU - which doesn't support mixed 1868 endian - is hotplugged in after this feature has been enabled, there could 1869 be unexpected results in the applications. 1870 1871 If unsure, say Y 1872endif # ARMV8_DEPRECATED 1873 1874endif # COMPAT 1875 1876menu "ARMv8.1 architectural features" 1877 1878config ARM64_HW_AFDBM 1879 bool "Support for hardware updates of the Access and Dirty page flags" 1880 default y 1881 help 1882 The ARMv8.1 architecture extensions introduce support for 1883 hardware updates of the access and dirty information in page 1884 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1885 capable processors, accesses to pages with PTE_AF cleared will 1886 set this bit instead of raising an access flag fault. 1887 Similarly, writes to read-only pages with the DBM bit set will 1888 clear the read-only bit (AP[2]) instead of raising a 1889 permission fault. 1890 1891 Kernels built with this configuration option enabled continue 1892 to work on pre-ARMv8.1 hardware and the performance impact is 1893 minimal. If unsure, say Y. 1894 1895config ARM64_PAN 1896 bool "Enable support for Privileged Access Never (PAN)" 1897 default y 1898 help 1899 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1900 prevents the kernel or hypervisor from accessing user-space (EL0) 1901 memory directly. 1902 1903 Choosing this option will cause any unprotected (not using 1904 copy_to_user et al) memory access to fail with a permission fault. 1905 1906 The feature is detected at runtime, and will remain as a 'nop' 1907 instruction if the cpu does not implement the feature. 1908 1909config ARM64_LSE_ATOMICS 1910 bool 1911 default ARM64_USE_LSE_ATOMICS 1912 1913config ARM64_USE_LSE_ATOMICS 1914 bool "Atomic instructions" 1915 default y 1916 help 1917 As part of the Large System Extensions, ARMv8.1 introduces new 1918 atomic instructions that are designed specifically to scale in 1919 very large systems. 1920 1921 Say Y here to make use of these instructions for the in-kernel 1922 atomic routines. This incurs a small overhead on CPUs that do 1923 not support these instructions. 1924 1925endmenu # "ARMv8.1 architectural features" 1926 1927menu "ARMv8.2 architectural features" 1928 1929config ARM64_PMEM 1930 bool "Enable support for persistent memory" 1931 select ARCH_HAS_PMEM_API 1932 select ARCH_HAS_UACCESS_FLUSHCACHE 1933 help 1934 Say Y to enable support for the persistent memory API based on the 1935 ARMv8.2 DCPoP feature. 1936 1937 The feature is detected at runtime, and the kernel will use DC CVAC 1938 operations if DC CVAP is not supported (following the behaviour of 1939 DC CVAP itself if the system does not define a point of persistence). 1940 1941config ARM64_RAS_EXTN 1942 bool "Enable support for RAS CPU Extensions" 1943 default y 1944 help 1945 CPUs that support the Reliability, Availability and Serviceability 1946 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1947 errors, classify them and report them to software. 1948 1949 On CPUs with these extensions system software can use additional 1950 barriers to determine if faults are pending and read the 1951 classification from a new set of registers. 1952 1953 Selecting this feature will allow the kernel to use these barriers 1954 and access the new registers if the system supports the extension. 1955 Platform RAS features may additionally depend on firmware support. 1956 1957config ARM64_CNP 1958 bool "Enable support for Common Not Private (CNP) translations" 1959 default y 1960 help 1961 Common Not Private (CNP) allows translation table entries to 1962 be shared between different PEs in the same inner shareable 1963 domain, so the hardware can use this fact to optimise the 1964 caching of such entries in the TLB. 1965 1966 Selecting this option allows the CNP feature to be detected 1967 at runtime, and does not affect PEs that do not implement 1968 this feature. 1969 1970endmenu # "ARMv8.2 architectural features" 1971 1972menu "ARMv8.3 architectural features" 1973 1974config ARM64_PTR_AUTH 1975 bool "Enable support for pointer authentication" 1976 default y 1977 help 1978 Pointer authentication (part of the ARMv8.3 Extensions) provides 1979 instructions for signing and authenticating pointers against secret 1980 keys, which can be used to mitigate Return Oriented Programming (ROP) 1981 and other attacks. 1982 1983 This option enables these instructions at EL0 (i.e. for userspace). 1984 Choosing this option will cause the kernel to initialise secret keys 1985 for each process at exec() time, with these keys being 1986 context-switched along with the process. 1987 1988 The feature is detected at runtime. If the feature is not present in 1989 hardware it will not be advertised to userspace/KVM guest nor will it 1990 be enabled. 1991 1992 If the feature is present on the boot CPU but not on a late CPU, then 1993 the late CPU will be parked. Also, if the boot CPU does not have 1994 address auth and the late CPU has then the late CPU will still boot 1995 but with the feature disabled. On such a system, this option should 1996 not be selected. 1997 1998config ARM64_PTR_AUTH_KERNEL 1999 bool "Use pointer authentication for kernel" 2000 default y 2001 depends on ARM64_PTR_AUTH 2002 # Modern compilers insert a .note.gnu.property section note for PAC 2003 # which is only understood by binutils starting with version 2.33.1. 2004 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 2005 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 2006 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2007 help 2008 If the compiler supports the -mbranch-protection or 2009 -msign-return-address flag (e.g. GCC 7 or later), then this option 2010 will cause the kernel itself to be compiled with return address 2011 protection. In this case, and if the target hardware is known to 2012 support pointer authentication, then CONFIG_STACKPROTECTOR can be 2013 disabled with minimal loss of protection. 2014 2015 This feature works with FUNCTION_GRAPH_TRACER option only if 2016 DYNAMIC_FTRACE_WITH_ARGS is enabled. 2017 2018config CC_HAS_BRANCH_PROT_PAC_RET 2019 # GCC 9 or later, clang 8 or later 2020 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 2021 2022config AS_HAS_CFI_NEGATE_RA_STATE 2023 # binutils 2.34+ 2024 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 2025 2026endmenu # "ARMv8.3 architectural features" 2027 2028menu "ARMv8.4 architectural features" 2029 2030config ARM64_AMU_EXTN 2031 bool "Enable support for the Activity Monitors Unit CPU extension" 2032 default y 2033 help 2034 The activity monitors extension is an optional extension introduced 2035 by the ARMv8.4 CPU architecture. This enables support for version 1 2036 of the activity monitors architecture, AMUv1. 2037 2038 To enable the use of this extension on CPUs that implement it, say Y. 2039 2040 Note that for architectural reasons, firmware _must_ implement AMU 2041 support when running on CPUs that present the activity monitors 2042 extension. The required support is present in: 2043 * Version 1.5 and later of the ARM Trusted Firmware 2044 2045 For kernels that have this configuration enabled but boot with broken 2046 firmware, you may need to say N here until the firmware is fixed. 2047 Otherwise you may experience firmware panics or lockups when 2048 accessing the counter registers. Even if you are not observing these 2049 symptoms, the values returned by the register reads might not 2050 correctly reflect reality. Most commonly, the value read will be 0, 2051 indicating that the counter is not enabled. 2052 2053config ARM64_TLB_RANGE 2054 bool "Enable support for tlbi range feature" 2055 default y 2056 help 2057 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 2058 range of input addresses. 2059 2060endmenu # "ARMv8.4 architectural features" 2061 2062menu "ARMv8.5 architectural features" 2063 2064config AS_HAS_ARMV8_5 2065 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 2066 2067config ARM64_BTI 2068 bool "Branch Target Identification support" 2069 default y 2070 help 2071 Branch Target Identification (part of the ARMv8.5 Extensions) 2072 provides a mechanism to limit the set of locations to which computed 2073 branch instructions such as BR or BLR can jump. 2074 2075 To make use of BTI on CPUs that support it, say Y. 2076 2077 BTI is intended to provide complementary protection to other control 2078 flow integrity protection mechanisms, such as the Pointer 2079 authentication mechanism provided as part of the ARMv8.3 Extensions. 2080 For this reason, it does not make sense to enable this option without 2081 also enabling support for pointer authentication. Thus, when 2082 enabling this option you should also select ARM64_PTR_AUTH=y. 2083 2084 Userspace binaries must also be specifically compiled to make use of 2085 this mechanism. If you say N here or the hardware does not support 2086 BTI, such binaries can still run, but you get no additional 2087 enforcement of branch destinations. 2088 2089config ARM64_BTI_KERNEL 2090 bool "Use Branch Target Identification for kernel" 2091 default y 2092 depends on ARM64_BTI 2093 depends on ARM64_PTR_AUTH_KERNEL 2094 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 2095 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 2096 depends on !CC_IS_GCC || GCC_VERSION >= 100100 2097 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106671 2098 depends on !CC_IS_GCC 2099 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_ARGS) 2100 help 2101 Build the kernel with Branch Target Identification annotations 2102 and enable enforcement of this for kernel code. When this option 2103 is enabled and the system supports BTI all kernel code including 2104 modular code must have BTI enabled. 2105 2106config CC_HAS_BRANCH_PROT_PAC_RET_BTI 2107 # GCC 9 or later, clang 8 or later 2108 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 2109 2110config ARM64_E0PD 2111 bool "Enable support for E0PD" 2112 default y 2113 help 2114 E0PD (part of the ARMv8.5 extensions) allows us to ensure 2115 that EL0 accesses made via TTBR1 always fault in constant time, 2116 providing similar benefits to KASLR as those provided by KPTI, but 2117 with lower overhead and without disrupting legitimate access to 2118 kernel memory such as SPE. 2119 2120 This option enables E0PD for TTBR1 where available. 2121 2122config ARM64_AS_HAS_MTE 2123 # Initial support for MTE went in binutils 2.32.0, checked with 2124 # ".arch armv8.5-a+memtag" below. However, this was incomplete 2125 # as a late addition to the final architecture spec (LDGM/STGM) 2126 # is only supported in the newer 2.32.x and 2.33 binutils 2127 # versions, hence the extra "stgm" instruction check below. 2128 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 2129 2130config ARM64_MTE 2131 bool "Memory Tagging Extension support" 2132 default y 2133 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 2134 depends on AS_HAS_ARMV8_5 2135 # Required for tag checking in the uaccess routines 2136 select ARM64_PAN 2137 select ARCH_HAS_SUBPAGE_FAULTS 2138 select ARCH_USES_HIGH_VMA_FLAGS 2139 select ARCH_USES_PG_ARCH_2 2140 select ARCH_USES_PG_ARCH_3 2141 help 2142 Memory Tagging (part of the ARMv8.5 Extensions) provides 2143 architectural support for run-time, always-on detection of 2144 various classes of memory error to aid with software debugging 2145 to eliminate vulnerabilities arising from memory-unsafe 2146 languages. 2147 2148 This option enables the support for the Memory Tagging 2149 Extension at EL0 (i.e. for userspace). 2150 2151 Selecting this option allows the feature to be detected at 2152 runtime. Any secondary CPU not implementing this feature will 2153 not be allowed a late bring-up. 2154 2155 Userspace binaries that want to use this feature must 2156 explicitly opt in. The mechanism for the userspace is 2157 described in: 2158 2159 Documentation/arch/arm64/memory-tagging-extension.rst. 2160 2161endmenu # "ARMv8.5 architectural features" 2162 2163menu "ARMv8.7 architectural features" 2164 2165config ARM64_EPAN 2166 bool "Enable support for Enhanced Privileged Access Never (EPAN)" 2167 default y 2168 depends on ARM64_PAN 2169 help 2170 Enhanced Privileged Access Never (EPAN) allows Privileged 2171 Access Never to be used with Execute-only mappings. 2172 2173 The feature is detected at runtime, and will remain disabled 2174 if the cpu does not implement the feature. 2175endmenu # "ARMv8.7 architectural features" 2176 2177config AS_HAS_MOPS 2178 def_bool $(as-instr,.arch_extension mops) 2179 2180menu "ARMv8.9 architectural features" 2181 2182config ARM64_POE 2183 prompt "Permission Overlay Extension" 2184 def_bool y 2185 select ARCH_USES_HIGH_VMA_FLAGS 2186 select ARCH_HAS_PKEYS 2187 help 2188 The Permission Overlay Extension is used to implement Memory 2189 Protection Keys. Memory Protection Keys provides a mechanism for 2190 enforcing page-based protections, but without requiring modification 2191 of the page tables when an application changes protection domains. 2192 2193 For details, see Documentation/core-api/protection-keys.rst 2194 2195 If unsure, say y. 2196 2197config ARCH_PKEY_BITS 2198 int 2199 default 3 2200 2201config ARM64_HAFT 2202 bool "Support for Hardware managed Access Flag for Table Descriptors" 2203 depends on ARM64_HW_AFDBM 2204 default y 2205 help 2206 The ARMv8.9/ARMv9.5 introduces the feature Hardware managed Access 2207 Flag for Table descriptors. When enabled an architectural executed 2208 memory access will update the Access Flag in each Table descriptor 2209 which is accessed during the translation table walk and for which 2210 the Access Flag is 0. The Access Flag of the Table descriptor use 2211 the same bit of PTE_AF. 2212 2213 The feature will only be enabled if all the CPUs in the system 2214 support this feature. If unsure, say Y. 2215 2216endmenu # "ARMv8.9 architectural features" 2217 2218menu "v9.4 architectural features" 2219 2220config ARM64_GCS 2221 bool "Enable support for Guarded Control Stack (GCS)" 2222 default y 2223 select ARCH_HAS_USER_SHADOW_STACK 2224 select ARCH_USES_HIGH_VMA_FLAGS 2225 depends on !UPROBES 2226 help 2227 Guarded Control Stack (GCS) provides support for a separate 2228 stack with restricted access which contains only return 2229 addresses. This can be used to harden against some attacks 2230 by comparing return address used by the program with what is 2231 stored in the GCS, and may also be used to efficiently obtain 2232 the call stack for applications such as profiling. 2233 2234 The feature is detected at runtime, and will remain disabled 2235 if the system does not implement the feature. 2236 2237endmenu # "v9.4 architectural features" 2238 2239config ARM64_SVE 2240 bool "ARM Scalable Vector Extension support" 2241 default y 2242 help 2243 The Scalable Vector Extension (SVE) is an extension to the AArch64 2244 execution state which complements and extends the SIMD functionality 2245 of the base architecture to support much larger vectors and to enable 2246 additional vectorisation opportunities. 2247 2248 To enable use of this extension on CPUs that implement it, say Y. 2249 2250 On CPUs that support the SVE2 extensions, this option will enable 2251 those too. 2252 2253 Note that for architectural reasons, firmware _must_ implement SVE 2254 support when running on SVE capable hardware. The required support 2255 is present in: 2256 2257 * version 1.5 and later of the ARM Trusted Firmware 2258 * the AArch64 boot wrapper since commit 5e1261e08abf 2259 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 2260 2261 For other firmware implementations, consult the firmware documentation 2262 or vendor. 2263 2264 If you need the kernel to boot on SVE-capable hardware with broken 2265 firmware, you may need to say N here until you get your firmware 2266 fixed. Otherwise, you may experience firmware panics or lockups when 2267 booting the kernel. If unsure and you are not observing these 2268 symptoms, you should assume that it is safe to say Y. 2269 2270config ARM64_SME 2271 bool "ARM Scalable Matrix Extension support" 2272 default y 2273 depends on ARM64_SVE 2274 help 2275 The Scalable Matrix Extension (SME) is an extension to the AArch64 2276 execution state which utilises a substantial subset of the SVE 2277 instruction set, together with the addition of new architectural 2278 register state capable of holding two dimensional matrix tiles to 2279 enable various matrix operations. 2280 2281config ARM64_PSEUDO_NMI 2282 bool "Support for NMI-like interrupts" 2283 select ARM_GIC_V3 2284 help 2285 Adds support for mimicking Non-Maskable Interrupts through the use of 2286 GIC interrupt priority. This support requires version 3 or later of 2287 ARM GIC. 2288 2289 This high priority configuration for interrupts needs to be 2290 explicitly enabled by setting the kernel parameter 2291 "irqchip.gicv3_pseudo_nmi" to 1. 2292 2293 If unsure, say N 2294 2295if ARM64_PSEUDO_NMI 2296config ARM64_DEBUG_PRIORITY_MASKING 2297 bool "Debug interrupt priority masking" 2298 help 2299 This adds runtime checks to functions enabling/disabling 2300 interrupts when using priority masking. The additional checks verify 2301 the validity of ICC_PMR_EL1 when calling concerned functions. 2302 2303 If unsure, say N 2304endif # ARM64_PSEUDO_NMI 2305 2306config RELOCATABLE 2307 bool "Build a relocatable kernel image" if EXPERT 2308 select ARCH_HAS_RELR 2309 default y 2310 help 2311 This builds the kernel as a Position Independent Executable (PIE), 2312 which retains all relocation metadata required to relocate the 2313 kernel binary at runtime to a different virtual address than the 2314 address it was linked at. 2315 Since AArch64 uses the RELA relocation format, this requires a 2316 relocation pass at runtime even if the kernel is loaded at the 2317 same address it was linked at. 2318 2319config RANDOMIZE_BASE 2320 bool "Randomize the address of the kernel image" 2321 select RELOCATABLE 2322 help 2323 Randomizes the virtual address at which the kernel image is 2324 loaded, as a security feature that deters exploit attempts 2325 relying on knowledge of the location of kernel internals. 2326 2327 It is the bootloader's job to provide entropy, by passing a 2328 random u64 value in /chosen/kaslr-seed at kernel entry. 2329 2330 When booting via the UEFI stub, it will invoke the firmware's 2331 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 2332 to the kernel proper. In addition, it will randomise the physical 2333 location of the kernel Image as well. 2334 2335 If unsure, say N. 2336 2337config RANDOMIZE_MODULE_REGION_FULL 2338 bool "Randomize the module region over a 2 GB range" 2339 depends on RANDOMIZE_BASE 2340 default y 2341 help 2342 Randomizes the location of the module region inside a 2 GB window 2343 covering the core kernel. This way, it is less likely for modules 2344 to leak information about the location of core kernel data structures 2345 but it does imply that function calls between modules and the core 2346 kernel will need to be resolved via veneers in the module PLT. 2347 2348 When this option is not set, the module region will be randomized over 2349 a limited range that contains the [_stext, _etext] interval of the 2350 core kernel, so branch relocations are almost always in range unless 2351 the region is exhausted. In this particular case of region 2352 exhaustion, modules might be able to fall back to a larger 2GB area. 2353 2354config CC_HAVE_STACKPROTECTOR_SYSREG 2355 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 2356 2357config STACKPROTECTOR_PER_TASK 2358 def_bool y 2359 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 2360 2361config UNWIND_PATCH_PAC_INTO_SCS 2362 bool "Enable shadow call stack dynamically using code patching" 2363 # needs Clang with https://github.com/llvm/llvm-project/commit/de07cde67b5d205d58690be012106022aea6d2b3 incorporated 2364 depends on CC_IS_CLANG && CLANG_VERSION >= 150000 2365 depends on ARM64_PTR_AUTH_KERNEL && CC_HAS_BRANCH_PROT_PAC_RET 2366 depends on SHADOW_CALL_STACK 2367 select UNWIND_TABLES 2368 select DYNAMIC_SCS 2369 2370config ARM64_CONTPTE 2371 bool "Contiguous PTE mappings for user memory" if EXPERT 2372 depends on TRANSPARENT_HUGEPAGE 2373 default y 2374 help 2375 When enabled, user mappings are configured using the PTE contiguous 2376 bit, for any mappings that meet the size and alignment requirements. 2377 This reduces TLB pressure and improves performance. 2378 2379endmenu # "Kernel Features" 2380 2381menu "Boot options" 2382 2383config ARM64_ACPI_PARKING_PROTOCOL 2384 bool "Enable support for the ARM64 ACPI parking protocol" 2385 depends on ACPI 2386 help 2387 Enable support for the ARM64 ACPI parking protocol. If disabled 2388 the kernel will not allow booting through the ARM64 ACPI parking 2389 protocol even if the corresponding data is present in the ACPI 2390 MADT table. 2391 2392config CMDLINE 2393 string "Default kernel command string" 2394 default "" 2395 help 2396 Provide a set of default command-line options at build time by 2397 entering them here. As a minimum, you should specify the the 2398 root device (e.g. root=/dev/nfs). 2399 2400choice 2401 prompt "Kernel command line type" 2402 depends on CMDLINE != "" 2403 default CMDLINE_FROM_BOOTLOADER 2404 help 2405 Choose how the kernel will handle the provided default kernel 2406 command line string. 2407 2408config CMDLINE_FROM_BOOTLOADER 2409 bool "Use bootloader kernel arguments if available" 2410 help 2411 Uses the command-line options passed by the boot loader. If 2412 the boot loader doesn't provide any, the default kernel command 2413 string provided in CMDLINE will be used. 2414 2415config CMDLINE_FORCE 2416 bool "Always use the default kernel command string" 2417 help 2418 Always use the default kernel command string, even if the boot 2419 loader passes other arguments to the kernel. 2420 This is useful if you cannot or don't want to change the 2421 command-line options your boot loader passes to the kernel. 2422 2423endchoice 2424 2425config EFI_STUB 2426 bool 2427 2428config EFI 2429 bool "UEFI runtime support" 2430 depends on OF && !CPU_BIG_ENDIAN 2431 depends on KERNEL_MODE_NEON 2432 select ARCH_SUPPORTS_ACPI 2433 select LIBFDT 2434 select UCS2_STRING 2435 select EFI_PARAMS_FROM_FDT 2436 select EFI_RUNTIME_WRAPPERS 2437 select EFI_STUB 2438 select EFI_GENERIC_STUB 2439 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 2440 default y 2441 help 2442 This option provides support for runtime services provided 2443 by UEFI firmware (such as non-volatile variables, realtime 2444 clock, and platform reset). A UEFI stub is also provided to 2445 allow the kernel to be booted as an EFI application. This 2446 is only useful on systems that have UEFI firmware. 2447 2448config COMPRESSED_INSTALL 2449 bool "Install compressed image by default" 2450 help 2451 This makes the regular "make install" install the compressed 2452 image we built, not the legacy uncompressed one. 2453 2454 You can check that a compressed image works for you by doing 2455 "make zinstall" first, and verifying that everything is fine 2456 in your environment before making "make install" do this for 2457 you. 2458 2459config DMI 2460 bool "Enable support for SMBIOS (DMI) tables" 2461 depends on EFI 2462 default y 2463 help 2464 This enables SMBIOS/DMI feature for systems. 2465 2466 This option is only useful on systems that have UEFI firmware. 2467 However, even with this option, the resultant kernel should 2468 continue to boot on existing non-UEFI platforms. 2469 2470endmenu # "Boot options" 2471 2472menu "Power management options" 2473 2474source "kernel/power/Kconfig" 2475 2476config ARCH_HIBERNATION_POSSIBLE 2477 def_bool y 2478 depends on CPU_PM 2479 2480config ARCH_HIBERNATION_HEADER 2481 def_bool y 2482 depends on HIBERNATION 2483 2484config ARCH_SUSPEND_POSSIBLE 2485 def_bool y 2486 2487endmenu # "Power management options" 2488 2489menu "CPU Power Management" 2490 2491source "drivers/cpuidle/Kconfig" 2492 2493source "drivers/cpufreq/Kconfig" 2494 2495endmenu # "CPU Power Management" 2496 2497source "drivers/acpi/Kconfig" 2498 2499source "arch/arm64/kvm/Kconfig" 2500 2501