1# SPDX-License-Identifier: GPL-2.0-only 2# 3# For a description of the syntax of this configuration file, 4# see Documentation/kbuild/kconfig-language.rst. 5# 6 7config 64BIT 8 bool 9 10config 32BIT 11 bool 12 13config RISCV 14 def_bool y 15 select ACPI_GENERIC_GSI if ACPI 16 select ACPI_MCFG if (ACPI && PCI) 17 select ACPI_PPTT if ACPI 18 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 19 select ACPI_SPCR_TABLE if ACPI 20 select ARCH_DMA_DEFAULT_COHERENT 21 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 22 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 23 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 24 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 25 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 26 select ARCH_HAS_BINFMT_FLAT 27 select ARCH_HAS_CURRENT_STACK_POINTER 28 select ARCH_HAS_DEBUG_VIRTUAL if MMU 29 select ARCH_HAS_DEBUG_VM_PGTABLE 30 select ARCH_HAS_DEBUG_WX 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_HW_PTE_YOUNG 36 select ARCH_HAS_KCOV 37 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 38 select ARCH_HAS_MEMBARRIER_CALLBACKS 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MMIOWB 41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 42 select ARCH_HAS_PMEM_API 43 select ARCH_HAS_PREEMPT_LAZY 44 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 45 select ARCH_HAS_PTDUMP if MMU 46 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU 47 select ARCH_HAS_PTE_SPECIAL 48 select ARCH_HAS_SET_DIRECT_MAP if MMU 49 select ARCH_HAS_SET_MEMORY if MMU 50 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 51 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 52 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 53 select ARCH_HAS_SYSCALL_WRAPPER 54 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 55 select ARCH_HAS_UBSAN 56 select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE 57 select ARCH_KEEP_MEMBLOCK if ACPI 58 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 59 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 60 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 61 select ARCH_STACKWALK 62 select ARCH_SUPPORTS_ATOMIC_RMW 63 # clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2 64 select ARCH_SUPPORTS_CFI_CLANG if CLANG_VERSION >= 170000 65 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 66 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 67 select ARCH_SUPPORTS_HUGETLBFS if MMU 68 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 69 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 70 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 71 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 72 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 73 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 74 select ARCH_SUPPORTS_RT 75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 76 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 77 select ARCH_USE_MEMTEST 78 select ARCH_USE_QUEUED_RWLOCKS 79 select ARCH_USE_SYM_ANNOTATIONS 80 select ARCH_USES_CFI_TRAPS if CFI_CLANG 81 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 82 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 83 select ARCH_WANT_FRAME_POINTERS 84 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 85 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 86 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 87 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 88 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 89 select ARCH_WANTS_NO_INSTR 90 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 91 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 92 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 93 select BUILDTIME_TABLE_SORT if MMU 94 select CLINT_TIMER if RISCV_M_MODE 95 select CLONE_BACKWARDS 96 select COMMON_CLK 97 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 98 select DYNAMIC_FTRACE if FUNCTION_TRACER 99 select EDAC_SUPPORT 100 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 101 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 102 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 103 select GENERIC_ARCH_TOPOLOGY 104 select GENERIC_ATOMIC64 if !64BIT 105 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 106 select GENERIC_CPU_DEVICES 107 select GENERIC_CPU_VULNERABILITIES 108 select GENERIC_EARLY_IOREMAP 109 select GENERIC_ENTRY 110 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 111 select GENERIC_IDLE_POLL_SETUP 112 select GENERIC_IOREMAP if MMU 113 select GENERIC_IRQ_IPI if SMP 114 select GENERIC_IRQ_IPI_MUX if SMP 115 select GENERIC_IRQ_MULTI_HANDLER 116 select GENERIC_IRQ_SHOW 117 select GENERIC_IRQ_SHOW_LEVEL 118 select GENERIC_LIB_DEVMEM_IS_ALLOWED 119 select GENERIC_PENDING_IRQ if SMP 120 select GENERIC_PCI_IOMAP 121 select GENERIC_SCHED_CLOCK 122 select GENERIC_SMP_IDLE_THREAD 123 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 124 select GENERIC_VDSO_DATA_STORE if MMU 125 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 126 select HARDIRQS_SW_RESEND 127 select HAS_IOPORT if MMU 128 select HAVE_ALIGNED_STRUCT_PAGE 129 select HAVE_ARCH_AUDITSYSCALL 130 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 131 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 132 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 133 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 134 select HAVE_ARCH_KASAN if MMU && 64BIT 135 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 136 select HAVE_ARCH_KFENCE if MMU && 64BIT 137 select HAVE_ARCH_KSTACK_ERASE 138 select HAVE_ARCH_KGDB if !XIP_KERNEL 139 select HAVE_ARCH_KGDB_QXFER_PKT 140 select HAVE_ARCH_MMAP_RND_BITS if MMU 141 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 142 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 143 select HAVE_ARCH_SECCOMP_FILTER 144 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 145 select HAVE_ARCH_TRACEHOOK 146 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU 148 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 149 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 150 select HAVE_ASM_MODVERSIONS 151 select HAVE_CONTEXT_TRACKING_USER 152 select HAVE_DEBUG_KMEMLEAK 153 select HAVE_DMA_CONTIGUOUS if MMU 154 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 155 select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C 156 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS 157 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG) 158 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 159 select HAVE_FTRACE_GRAPH_FUNC 160 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 161 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 162 select HAVE_FUNCTION_GRAPH_FREGS 163 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && HAVE_DYNAMIC_FTRACE 164 select HAVE_EBPF_JIT if MMU 165 select HAVE_GUP_FAST if MMU 166 select HAVE_FUNCTION_ARG_ACCESS_API 167 select HAVE_FUNCTION_ERROR_INJECTION 168 select HAVE_GCC_PLUGINS 169 select HAVE_GENERIC_VDSO if MMU && 64BIT 170 select HAVE_IRQ_TIME_ACCOUNTING 171 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 172 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 173 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 174 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 175 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 176 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 177 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 178 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT 179 select HAVE_KPROBES if !XIP_KERNEL 180 select HAVE_KRETPROBES if !XIP_KERNEL 181 # https://github.com/ClangBuiltLinux/linux/issues/1881 182 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 183 select HAVE_MOVE_PMD 184 select HAVE_MOVE_PUD 185 select HAVE_PAGE_SIZE_4KB 186 select HAVE_PCI 187 select HAVE_PERF_EVENTS 188 select HAVE_PERF_REGS 189 select HAVE_PERF_USER_STACK_DUMP 190 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 191 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 192 select HAVE_REGS_AND_STACK_ACCESS_API 193 select HAVE_RETHOOK if !XIP_KERNEL 194 select HAVE_RSEQ 195 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 196 select HAVE_SAMPLE_FTRACE_DIRECT 197 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 198 select HAVE_STACKPROTECTOR 199 select HAVE_SYSCALL_TRACEPOINTS 200 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 201 select IRQ_DOMAIN 202 select IRQ_FORCED_THREADING 203 select KASAN_VMALLOC if KASAN 204 select LOCK_MM_AND_FIND_VMA 205 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 206 select MODULES_USE_ELF_RELA if MODULES 207 select OF 208 select OF_EARLY_FLATTREE 209 select OF_IRQ 210 select PCI_DOMAINS_GENERIC if PCI 211 select PCI_ECAM if (ACPI && PCI) 212 select PCI_MSI if PCI 213 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 214 select RISCV_ALTERNATIVE if !XIP_KERNEL 215 select RISCV_APLIC 216 select RISCV_IMSIC 217 select RISCV_INTC 218 select RISCV_TIMER if RISCV_SBI 219 select SIFIVE_PLIC 220 select SPARSE_IRQ 221 select SYSCTL_EXCEPTION_TRACE 222 select THREAD_INFO_IN_TASK 223 select TRACE_IRQFLAGS_SUPPORT 224 select UACCESS_MEMCPY if !MMU 225 select VDSO_GETRANDOM if HAVE_GENERIC_VDSO 226 select USER_STACKTRACE_SUPPORT 227 select ZONE_DMA32 if 64BIT 228 229config RUSTC_SUPPORTS_RISCV 230 def_bool y 231 depends on 64BIT 232 # Shadow call stack requires rustc version 1.82+ due to use of the 233 # -Zsanitizer=shadow-call-stack flag. 234 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 235 236config CLANG_SUPPORTS_DYNAMIC_FTRACE 237 def_bool CC_IS_CLANG 238 # https://github.com/ClangBuiltLinux/linux/issues/1817 239 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 240 241config GCC_SUPPORTS_DYNAMIC_FTRACE 242 def_bool CC_IS_GCC 243 depends on $(cc-option,-fpatchable-function-entry=8) 244 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C 245 246config HAVE_SHADOW_CALL_STACK 247 def_bool $(cc-option,-fsanitize=shadow-call-stack) 248 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 249 depends on $(ld-option,--no-relax-gp) 250 251config RISCV_USE_LINKER_RELAXATION 252 def_bool y 253 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 254 depends on !LD_IS_LLD || LLD_VERSION >= 150000 255 256# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 257config ARCH_HAS_BROKEN_DWARF5 258 def_bool y 259 depends on RISCV_USE_LINKER_RELAXATION 260 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 261 depends on AS_IS_LLVM && AS_VERSION < 180000 262 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 263 depends on LD_IS_LLD && LLD_VERSION < 180000 264 265config ARCH_MMAP_RND_BITS_MIN 266 default 18 if 64BIT 267 default 8 268 269config ARCH_MMAP_RND_COMPAT_BITS_MIN 270 default 8 271 272# max bits determined by the following formula: 273# VA_BITS - PAGE_SHIFT - 3 274config ARCH_MMAP_RND_BITS_MAX 275 default 24 if 64BIT # SV39 based 276 default 17 277 278config ARCH_MMAP_RND_COMPAT_BITS_MAX 279 default 17 280 281# set if we run in machine mode, cleared if we run in supervisor mode 282config RISCV_M_MODE 283 bool "Build a kernel that runs in machine mode" 284 depends on !MMU 285 default y 286 help 287 Select this option if you want to run the kernel in M-mode, 288 without the assistance of any other firmware. 289 290# set if we are running in S-mode and can use SBI calls 291config RISCV_SBI 292 bool 293 depends on !RISCV_M_MODE 294 default y 295 296config MMU 297 bool "MMU-based Paged Memory Management Support" 298 default y 299 help 300 Select if you want MMU-based virtualised addressing space 301 support by paged memory management. If unsure, say 'Y'. 302 303config KASAN_SHADOW_OFFSET 304 hex 305 depends on KASAN_GENERIC 306 default 0xdfffffff00000000 if 64BIT 307 default 0xffffffff if 32BIT 308 309config ARCH_FLATMEM_ENABLE 310 def_bool !NUMA 311 312config ARCH_SPARSEMEM_ENABLE 313 def_bool y 314 depends on MMU 315 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 316 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 317 318config ARCH_SELECT_MEMORY_MODEL 319 def_bool ARCH_SPARSEMEM_ENABLE 320 321config ARCH_SUPPORTS_UPROBES 322 def_bool y 323 324config STACKTRACE_SUPPORT 325 def_bool y 326 327config GENERIC_BUG 328 def_bool y 329 depends on BUG 330 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 331 332config GENERIC_BUG_RELATIVE_POINTERS 333 bool 334 335config GENERIC_CALIBRATE_DELAY 336 def_bool y 337 338config GENERIC_CSUM 339 def_bool y 340 341config GENERIC_HWEIGHT 342 def_bool y 343 344config FIX_EARLYCON_MEM 345 def_bool MMU 346 347config ILLEGAL_POINTER_VALUE 348 hex 349 default 0 if 32BIT 350 default 0xdead000000000000 if 64BIT 351 352config PGTABLE_LEVELS 353 int 354 default 5 if 64BIT 355 default 2 356 357config LOCKDEP_SUPPORT 358 def_bool y 359 360config RISCV_DMA_NONCOHERENT 361 bool 362 select ARCH_HAS_DMA_PREP_COHERENT 363 select ARCH_HAS_SETUP_DMA_OPS 364 select ARCH_HAS_SYNC_DMA_FOR_CPU 365 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 366 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 367 368config RISCV_NONSTANDARD_CACHE_OPS 369 bool 370 help 371 This enables function pointer support for non-standard noncoherent 372 systems to handle cache management. 373 374config AS_HAS_INSN 375 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 376 377config AS_HAS_OPTION_ARCH 378 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 379 def_bool y 380 depends on $(as-instr, .option arch$(comma) +m) 381 382source "arch/riscv/Kconfig.socs" 383source "arch/riscv/Kconfig.errata" 384 385menu "Platform type" 386 387config NONPORTABLE 388 bool "Allow configurations that result in non-portable kernels" 389 help 390 RISC-V kernel binaries are compatible between all known systems 391 whenever possible, but there are some use cases that can only be 392 satisfied by configurations that result in kernel binaries that are 393 not portable between systems. 394 395 Selecting N does not guarantee kernels will be portable to all known 396 systems. Selecting any of the options guarded by NONPORTABLE will 397 result in kernel binaries that are unlikely to be portable between 398 systems. 399 400 If unsure, say N. 401 402choice 403 prompt "Base ISA" 404 default ARCH_RV64I 405 help 406 This selects the base ISA that this kernel will target and must match 407 the target platform. 408 409config ARCH_RV32I 410 bool "RV32I" 411 depends on NONPORTABLE 412 select 32BIT 413 select GENERIC_LIB_ASHLDI3 414 select GENERIC_LIB_ASHRDI3 415 select GENERIC_LIB_LSHRDI3 416 select GENERIC_LIB_UCMPDI2 417 418config ARCH_RV64I 419 bool "RV64I" 420 select 64BIT 421 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 422 select SWIOTLB if MMU 423 424endchoice 425 426# We must be able to map all physical memory into the kernel, but the compiler 427# is still a bit more efficient when generating code if it's setup in a manner 428# such that it can only map 2GiB of memory. 429choice 430 prompt "Kernel Code Model" 431 default CMODEL_MEDLOW if 32BIT 432 default CMODEL_MEDANY if 64BIT 433 434 config CMODEL_MEDLOW 435 bool "medium low code model" 436 config CMODEL_MEDANY 437 bool "medium any code model" 438endchoice 439 440config MODULE_SECTIONS 441 bool 442 select HAVE_MOD_ARCH_SPECIFIC 443 444config SMP 445 bool "Symmetric Multi-Processing" 446 help 447 This enables support for systems with more than one CPU. If 448 you say N here, the kernel will run on single and 449 multiprocessor machines, but will use only one CPU of a 450 multiprocessor machine. If you say Y here, the kernel will run 451 on many, but not all, single processor machines. On a single 452 processor machine, the kernel will run faster if you say N 453 here. 454 455 If you don't know what to do here, say N. 456 457config SCHED_MC 458 bool "Multi-core scheduler support" 459 depends on SMP 460 help 461 Multi-core scheduler support improves the CPU scheduler's decision 462 making when dealing with multi-core CPU chips at a cost of slightly 463 increased overhead in some places. If unsure say N here. 464 465config NR_CPUS 466 int "Maximum number of CPUs (2-512)" 467 depends on SMP 468 range 2 512 if !RISCV_SBI_V01 469 range 2 32 if RISCV_SBI_V01 && 32BIT 470 range 2 64 if RISCV_SBI_V01 && 64BIT 471 default "32" if 32BIT 472 default "64" if 64BIT 473 474config HOTPLUG_CPU 475 bool "Support for hot-pluggable CPUs" 476 depends on SMP 477 select GENERIC_IRQ_MIGRATION 478 help 479 480 Say Y here to experiment with turning CPUs off and on. CPUs 481 can be controlled through /sys/devices/system/cpu. 482 483 Say N if you want to disable CPU hotplug. 484 485choice 486 prompt "CPU Tuning" 487 default TUNE_GENERIC 488 489config TUNE_GENERIC 490 bool "generic" 491 492endchoice 493 494# Common NUMA Features 495config NUMA 496 bool "NUMA Memory Allocation and Scheduler Support" 497 depends on SMP && MMU 498 select ARCH_SUPPORTS_NUMA_BALANCING 499 select GENERIC_ARCH_NUMA 500 select HAVE_SETUP_PER_CPU_AREA 501 select NEED_PER_CPU_EMBED_FIRST_CHUNK 502 select NEED_PER_CPU_PAGE_FIRST_CHUNK 503 select OF_NUMA 504 select USE_PERCPU_NUMA_NODE_ID 505 help 506 Enable NUMA (Non-Uniform Memory Access) support. 507 508 The kernel will try to allocate memory used by a CPU on the 509 local memory of the CPU and add some more NUMA awareness to the kernel. 510 511config NODES_SHIFT 512 int "Maximum NUMA Nodes (as a power of 2)" 513 range 1 10 514 default "2" 515 depends on NUMA 516 help 517 Specify the maximum number of NUMA Nodes available on the target 518 system. Increases memory reserved to accommodate various tables. 519 520choice 521 prompt "RISC-V spinlock type" 522 default RISCV_COMBO_SPINLOCKS 523 524config RISCV_TICKET_SPINLOCKS 525 bool "Using ticket spinlock" 526 527config RISCV_QUEUED_SPINLOCKS 528 bool "Using queued spinlock" 529 depends on SMP && MMU && NONPORTABLE 530 select ARCH_USE_QUEUED_SPINLOCKS 531 help 532 The queued spinlock implementation requires the forward progress 533 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 534 LR/SC with Ziccrse provide such guarantee. 535 536 Select this if and only if Zabha or Ziccrse is available on your 537 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 538 without one of those extensions. 539 540 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 541 when supported and otherwise ticket spinlocks. 542 543config RISCV_COMBO_SPINLOCKS 544 bool "Using combo spinlock" 545 depends on SMP && MMU 546 select ARCH_USE_QUEUED_SPINLOCKS 547 help 548 Embed both queued spinlock and ticket lock so that the spinlock 549 implementation can be chosen at runtime. 550 551endchoice 552 553config RISCV_ALTERNATIVE 554 bool 555 depends on !XIP_KERNEL 556 help 557 This Kconfig allows the kernel to automatically patch the 558 erratum or cpufeature required by the execution platform at run 559 time. The code patching overhead is minimal, as it's only done 560 once at boot and once on each module load. 561 562config RISCV_ALTERNATIVE_EARLY 563 bool 564 depends on RISCV_ALTERNATIVE 565 help 566 Allows early patching of the kernel for special errata 567 568config RISCV_ISA_C 569 bool "Emit compressed instructions when building Linux" 570 default y 571 help 572 Adds "C" to the ISA subsets that the toolchain is allowed to emit 573 when building Linux, which results in compressed instructions in the 574 Linux binary. This option produces a kernel that will not run on 575 systems that do not support compressed instructions. 576 577 If you don't know what to do here, say Y. 578 579config RISCV_ISA_SUPM 580 bool "Supm extension for userspace pointer masking" 581 depends on 64BIT 582 default y 583 help 584 Add support for pointer masking in userspace (Supm) when the 585 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 586 587 If this option is disabled, userspace will be unable to use 588 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 589 590config RISCV_ISA_SVNAPOT 591 bool "Svnapot extension support for supervisor mode NAPOT pages" 592 depends on 64BIT && MMU 593 depends on RISCV_ALTERNATIVE 594 default y 595 help 596 Enable support for the Svnapot ISA-extension when it is detected 597 at boot. 598 599 The Svnapot extension is used to mark contiguous PTEs as a range 600 of contiguous virtual-to-physical translations for a naturally 601 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 602 size. When HUGETLBFS is also selected this option unconditionally 603 allocates some memory for each NAPOT page size supported by the kernel. 604 When optimizing for low memory consumption and for platforms without 605 the Svnapot extension, it may be better to say N here. 606 607 If you don't know what to do here, say Y. 608 609config RISCV_ISA_SVPBMT 610 bool "Svpbmt extension support for supervisor mode page-based memory types" 611 depends on 64BIT && MMU 612 depends on RISCV_ALTERNATIVE 613 default y 614 help 615 Add support for the Svpbmt ISA-extension (Supervisor-mode: 616 page-based memory types) in the kernel when it is detected at boot. 617 618 The memory type for a page contains a combination of attributes 619 that indicate the cacheability, idempotency, and ordering 620 properties for access to that page. 621 622 The Svpbmt extension is only available on 64-bit cpus. 623 624 If you don't know what to do here, say Y. 625 626config TOOLCHAIN_HAS_V 627 bool 628 default y 629 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 630 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 631 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 632 depends on AS_HAS_OPTION_ARCH 633 634config RISCV_ISA_V 635 bool "Vector extension support" 636 depends on TOOLCHAIN_HAS_V 637 depends on FPU 638 select DYNAMIC_SIGFRAME 639 default y 640 help 641 Add support for the Vector extension when it is detected at boot. 642 When this option is disabled, neither the kernel nor userspace may 643 use vector procedures. 644 645 If you don't know what to do here, say Y. 646 647config RISCV_ISA_V_DEFAULT_ENABLE 648 bool "Enable userspace Vector by default" 649 depends on RISCV_ISA_V 650 default y 651 help 652 Say Y here if you want to enable Vector in userspace by default. 653 Otherwise, userspace has to make explicit prctl() call to enable 654 Vector, or enable it via the sysctl interface. 655 656 If you don't know what to do here, say Y. 657 658config RISCV_ISA_V_UCOPY_THRESHOLD 659 int "Threshold size for vectorized user copies" 660 depends on RISCV_ISA_V 661 default 768 662 help 663 Prefer using vectorized copy_to_user()/copy_from_user() when the 664 workload size exceeds this value. 665 666config RISCV_ISA_V_PREEMPTIVE 667 bool "Run kernel-mode Vector with kernel preemption" 668 depends on PREEMPTION 669 depends on RISCV_ISA_V 670 default y 671 help 672 Usually, in-kernel SIMD routines are run with preemption disabled. 673 Functions which invoke long running SIMD thus must yield the core's 674 vector unit to prevent blocking other tasks for too long. 675 676 This config allows the kernel to run SIMD without explicitly disabling 677 preemption. Enabling this config will result in higher memory consumption 678 due to the allocation of per-task's kernel Vector context. 679 680config RISCV_ISA_ZAWRS 681 bool "Zawrs extension support for more efficient busy waiting" 682 depends on RISCV_ALTERNATIVE 683 default y 684 help 685 The Zawrs extension defines instructions to be used in polling loops 686 which allow a hart to enter a low-power state or to trap to the 687 hypervisor while waiting on a store to a memory location. Enable the 688 use of these instructions in the kernel when the Zawrs extension is 689 detected at boot. 690 691config TOOLCHAIN_HAS_ZABHA 692 bool 693 default y 694 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 695 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 696 depends on AS_HAS_OPTION_ARCH 697 698config RISCV_ISA_ZABHA 699 bool "Zabha extension support for atomic byte/halfword operations" 700 depends on TOOLCHAIN_HAS_ZABHA 701 depends on RISCV_ALTERNATIVE 702 default y 703 help 704 Enable the use of the Zabha ISA-extension to implement kernel 705 byte/halfword atomic memory operations when it is detected at boot. 706 707 If you don't know what to do here, say Y. 708 709config TOOLCHAIN_HAS_ZACAS 710 bool 711 default y 712 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 713 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 714 depends on AS_HAS_OPTION_ARCH 715 716config RISCV_ISA_ZACAS 717 bool "Zacas extension support for atomic CAS" 718 depends on TOOLCHAIN_HAS_ZACAS 719 depends on RISCV_ALTERNATIVE 720 default y 721 help 722 Enable the use of the Zacas ISA-extension to implement kernel atomic 723 cmpxchg operations when it is detected at boot. 724 725 If you don't know what to do here, say Y. 726 727config TOOLCHAIN_HAS_ZBB 728 bool 729 default y 730 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 731 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 732 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 733 depends on AS_HAS_OPTION_ARCH 734 735# This symbol indicates that the toolchain supports all v1.0 vector crypto 736# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 737# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 738config TOOLCHAIN_HAS_VECTOR_CRYPTO 739 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 740 depends on AS_HAS_OPTION_ARCH 741 742config TOOLCHAIN_HAS_ZBA 743 bool 744 default y 745 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 746 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 747 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 748 depends on AS_HAS_OPTION_ARCH 749 750config RISCV_ISA_ZBA 751 bool "Zba extension support for bit manipulation instructions" 752 default y 753 help 754 Add support for enabling optimisations in the kernel when the Zba 755 extension is detected at boot. 756 757 The Zba extension provides instructions to accelerate the generation 758 of addresses that index into arrays of basic data types. 759 760 If you don't know what to do here, say Y. 761 762config RISCV_ISA_ZBB 763 bool "Zbb extension support for bit manipulation instructions" 764 depends on RISCV_ALTERNATIVE 765 default y 766 help 767 Add support for enabling optimisations in the kernel when the 768 Zbb extension is detected at boot. Some optimisations may 769 additionally depend on toolchain support for Zbb. 770 771 The Zbb extension provides instructions to accelerate a number 772 of bit-specific operations (count bit population, sign extending, 773 bitrotation, etc). 774 775 If you don't know what to do here, say Y. 776 777config TOOLCHAIN_HAS_ZBC 778 bool 779 default y 780 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 781 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 782 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 783 depends on AS_HAS_OPTION_ARCH 784 785config RISCV_ISA_ZBC 786 bool "Zbc extension support for carry-less multiplication instructions" 787 depends on TOOLCHAIN_HAS_ZBC 788 depends on MMU 789 depends on RISCV_ALTERNATIVE 790 default y 791 help 792 Adds support to dynamically detect the presence of the Zbc 793 extension (carry-less multiplication) and enable its usage. 794 795 The Zbc extension could accelerate CRC (cyclic redundancy check) 796 calculations. 797 798 If you don't know what to do here, say Y. 799 800config TOOLCHAIN_HAS_ZBKB 801 bool 802 default y 803 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 804 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 805 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 806 depends on AS_HAS_OPTION_ARCH 807 808config RISCV_ISA_ZBKB 809 bool "Zbkb extension support for bit manipulation instructions" 810 depends on TOOLCHAIN_HAS_ZBKB 811 depends on RISCV_ALTERNATIVE 812 default y 813 help 814 Adds support to dynamically detect the presence of the ZBKB 815 extension (bit manipulation for cryptography) and enable its usage. 816 817 The Zbkb extension provides instructions to accelerate a number 818 of common cryptography operations (pack, zip, etc). 819 820 If you don't know what to do here, say Y. 821 822config RISCV_ISA_ZICBOM 823 bool "Zicbom extension support for non-coherent DMA operation" 824 depends on MMU 825 depends on RISCV_ALTERNATIVE 826 default y 827 select RISCV_DMA_NONCOHERENT 828 select DMA_DIRECT_REMAP 829 help 830 Add support for the Zicbom extension (Cache Block Management 831 Operations) and enable its use in the kernel when it is detected 832 at boot. 833 834 The Zicbom extension can be used to handle for example 835 non-coherent DMA support on devices that need it. 836 837 If you don't know what to do here, say Y. 838 839config RISCV_ISA_ZICBOZ 840 bool "Zicboz extension support for faster zeroing of memory" 841 depends on RISCV_ALTERNATIVE 842 default y 843 help 844 Enable the use of the Zicboz extension (cbo.zero instruction) 845 in the kernel when it is detected at boot. 846 847 The Zicboz extension is used for faster zeroing of memory. 848 849 If you don't know what to do here, say Y. 850 851config RISCV_ISA_ZICBOP 852 bool "Zicbop extension support for cache block prefetch" 853 depends on MMU 854 depends on RISCV_ALTERNATIVE 855 default y 856 help 857 Adds support to dynamically detect the presence of the ZICBOP 858 extension (Cache Block Prefetch Operations) and enable its 859 usage. 860 861 The Zicbop extension can be used to prefetch cache blocks for 862 read/write fetch. 863 864 If you don't know what to do here, say Y. 865 866config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 867 def_bool y 868 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 869 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 870 depends on AS_IS_GNU && AS_VERSION >= 23600 871 help 872 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 873 20191213 version, which moves some instructions from the I extension to 874 the Zicsr and Zifencei extensions. This requires explicitly specifying 875 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 876 and Zifencei are supported in binutils from version 2.36 onwards. 877 To make life easier, and avoid forcing toolchains that default to a 878 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 879 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 880 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 881 882config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 883 def_bool y 884 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 885 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 886 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 887 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 888 help 889 Certain versions of clang and GCC do not support zicsr and zifencei via 890 -march. This option causes an older ISA spec compatible with these older 891 versions of clang and GCC to be passed to GAS, which has the same result 892 as passing zicsr and zifencei to -march. 893 894config FPU 895 bool "FPU support" 896 default y 897 help 898 Add support for floating point operations when an FPU is detected at 899 boot. When this option is disabled, neither the kernel nor userspace 900 may use the floating point unit. 901 902 If you don't know what to do here, say Y. 903 904config IRQ_STACKS 905 bool "Independent irq & softirq stacks" if EXPERT 906 default y 907 select HAVE_IRQ_EXIT_ON_IRQ_STACK 908 select HAVE_SOFTIRQ_ON_OWN_STACK 909 help 910 Add independent irq & softirq stacks for percpu to prevent kernel stack 911 overflows. We may save some memory footprint by disabling IRQ_STACKS. 912 913config THREAD_SIZE_ORDER 914 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 915 range 0 4 916 default 1 if 32BIT 917 default 2 918 help 919 Specify the Pages of thread stack size (from 4KB to 64KB), which also 920 affects irq stack size, which is equal to thread stack size. 921 922config RISCV_MISALIGNED 923 bool 924 help 925 Embed support for detecting and emulating misaligned 926 scalar or vector loads and stores. 927 928config RISCV_SCALAR_MISALIGNED 929 bool 930 select RISCV_MISALIGNED 931 select SYSCTL_ARCH_UNALIGN_ALLOW 932 help 933 Embed support for emulating misaligned loads and stores. 934 935config RISCV_VECTOR_MISALIGNED 936 bool 937 select RISCV_MISALIGNED 938 depends on RISCV_ISA_V 939 help 940 Enable detecting support for vector misaligned loads and stores. 941 942choice 943 prompt "Unaligned Accesses Support" 944 default RISCV_PROBE_UNALIGNED_ACCESS 945 help 946 This determines the level of support for unaligned accesses. This 947 information is used by the kernel to perform optimizations. It is also 948 exposed to user space via the hwprobe syscall. The hardware will be 949 probed at boot by default. 950 951config RISCV_PROBE_UNALIGNED_ACCESS 952 bool "Probe for hardware unaligned access support" 953 select RISCV_SCALAR_MISALIGNED 954 help 955 During boot, the kernel will run a series of tests to determine the 956 speed of unaligned accesses. This probing will dynamically determine 957 the speed of unaligned accesses on the underlying system. If unaligned 958 memory accesses trap into the kernel as they are not supported by the 959 system, the kernel will emulate the unaligned accesses to preserve the 960 UABI. 961 962config RISCV_EMULATED_UNALIGNED_ACCESS 963 bool "Emulate unaligned access where system support is missing" 964 select RISCV_SCALAR_MISALIGNED 965 help 966 If unaligned memory accesses trap into the kernel as they are not 967 supported by the system, the kernel will emulate the unaligned 968 accesses to preserve the UABI. When the underlying system does support 969 unaligned accesses, the unaligned accesses are assumed to be slow. 970 971config RISCV_SLOW_UNALIGNED_ACCESS 972 bool "Assume the system supports slow unaligned memory accesses" 973 depends on NONPORTABLE 974 help 975 Assume that the system supports slow unaligned memory accesses. The 976 kernel and userspace programs may not be able to run at all on systems 977 that do not support unaligned memory accesses. 978 979config RISCV_EFFICIENT_UNALIGNED_ACCESS 980 bool "Assume the system supports fast unaligned memory accesses" 981 depends on NONPORTABLE 982 select DCACHE_WORD_ACCESS if MMU 983 select HAVE_EFFICIENT_UNALIGNED_ACCESS 984 help 985 Assume that the system supports fast unaligned memory accesses. When 986 enabled, this option improves the performance of the kernel on such 987 systems. However, the kernel and userspace programs will run much more 988 slowly, or will not be able to run at all, on systems that do not 989 support efficient unaligned memory accesses. 990 991endchoice 992 993choice 994 prompt "Vector unaligned Accesses Support" 995 depends on RISCV_ISA_V 996 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 997 help 998 This determines the level of support for vector unaligned accesses. This 999 information is used by the kernel to perform optimizations. It is also 1000 exposed to user space via the hwprobe syscall. The hardware will be 1001 probed at boot by default. 1002 1003config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1004 bool "Probe speed of vector unaligned accesses" 1005 select RISCV_VECTOR_MISALIGNED 1006 depends on RISCV_ISA_V 1007 help 1008 During boot, the kernel will run a series of tests to determine the 1009 speed of vector unaligned accesses if they are supported. This probing 1010 will dynamically determine the speed of vector unaligned accesses on 1011 the underlying system if they are supported. 1012 1013config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1014 bool "Assume the system supports slow vector unaligned memory accesses" 1015 depends on NONPORTABLE 1016 help 1017 Assume that the system supports slow vector unaligned memory accesses. The 1018 kernel and userspace programs may not be able to run at all on systems 1019 that do not support unaligned memory accesses. 1020 1021config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1022 bool "Assume the system supports fast vector unaligned memory accesses" 1023 depends on NONPORTABLE 1024 help 1025 Assume that the system supports fast vector unaligned memory accesses. When 1026 enabled, this option improves the performance of the kernel on such 1027 systems. However, the kernel and userspace programs will run much more 1028 slowly, or will not be able to run at all, on systems that do not 1029 support efficient unaligned memory accesses. 1030 1031endchoice 1032 1033source "arch/riscv/Kconfig.vendor" 1034 1035endmenu # "Platform type" 1036 1037menu "Kernel features" 1038 1039source "kernel/Kconfig.hz" 1040 1041config RISCV_SBI_V01 1042 bool "SBI v0.1 support" 1043 depends on RISCV_SBI 1044 help 1045 This config allows kernel to use SBI v0.1 APIs. This will be 1046 deprecated in future once legacy M-mode software are no longer in use. 1047 1048config RISCV_BOOT_SPINWAIT 1049 bool "Spinwait booting method" 1050 depends on SMP 1051 default y if RISCV_SBI_V01 || RISCV_M_MODE 1052 help 1053 This enables support for booting Linux via spinwait method. In the 1054 spinwait method, all cores randomly jump to Linux. One of the cores 1055 gets chosen via lottery and all other keep spinning on a percpu 1056 variable. This method cannot support CPU hotplug and sparse hartid 1057 scheme. It should be only enabled for M-mode Linux or platforms relying 1058 on older firmware without SBI HSM extension. All other platforms should 1059 rely on ordered booting via SBI HSM extension which gets chosen 1060 dynamically at runtime if the firmware supports it. 1061 1062 Since spinwait is incompatible with sparse hart IDs, it requires 1063 NR_CPUS be large enough to contain the physical hart ID of the first 1064 hart to enter Linux. 1065 1066 If unsure what to do here, say N. 1067 1068config ARCH_SUPPORTS_KEXEC 1069 def_bool y 1070 1071config ARCH_SELECTS_KEXEC 1072 def_bool y 1073 depends on KEXEC 1074 select HOTPLUG_CPU if SMP 1075 1076config ARCH_SUPPORTS_KEXEC_FILE 1077 def_bool 64BIT 1078 1079config ARCH_SELECTS_KEXEC_FILE 1080 def_bool y 1081 depends on KEXEC_FILE 1082 select HAVE_IMA_KEXEC if IMA 1083 select KEXEC_ELF 1084 1085config ARCH_SUPPORTS_KEXEC_PURGATORY 1086 def_bool ARCH_SUPPORTS_KEXEC_FILE 1087 1088config ARCH_SUPPORTS_CRASH_DUMP 1089 def_bool y 1090 1091config ARCH_DEFAULT_CRASH_DUMP 1092 def_bool y 1093 1094config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1095 def_bool CRASH_RESERVE 1096 1097config COMPAT 1098 bool "Kernel support for 32-bit U-mode" 1099 default 64BIT 1100 depends on 64BIT && MMU 1101 help 1102 This option enables support for a 32-bit U-mode running under a 64-bit 1103 kernel at S-mode. riscv32-specific components such as system calls, 1104 the user helper functions (vdso), signal rt_frame functions and the 1105 ptrace interface are handled appropriately by the kernel. 1106 1107 If you want to execute 32-bit userspace applications, say Y. 1108 1109config PARAVIRT 1110 bool "Enable paravirtualization code" 1111 depends on RISCV_SBI 1112 help 1113 This changes the kernel so it can modify itself when it is run 1114 under a hypervisor, potentially improving performance significantly 1115 over full virtualization. 1116 1117config PARAVIRT_TIME_ACCOUNTING 1118 bool "Paravirtual steal time accounting" 1119 depends on PARAVIRT 1120 help 1121 Select this option to enable fine granularity task steal time 1122 accounting. Time spent executing other tasks in parallel with 1123 the current vCPU is discounted from the vCPU power. To account for 1124 that, there can be a small performance impact. 1125 1126 If in doubt, say N here. 1127 1128config RELOCATABLE 1129 bool "Build a relocatable kernel" 1130 depends on !XIP_KERNEL 1131 select MODULE_SECTIONS if MODULES 1132 select ARCH_VMLINUX_NEEDS_RELOCS 1133 help 1134 This builds a kernel as a Position Independent Executable (PIE), 1135 which retains all relocation metadata required to relocate the 1136 kernel binary at runtime to a different virtual address than the 1137 address it was linked at. 1138 Since RISCV uses the RELA relocation format, this requires a 1139 relocation pass at runtime even if the kernel is loaded at the 1140 same address it was linked at. 1141 1142 If unsure, say N. 1143 1144config RANDOMIZE_BASE 1145 bool "Randomize the address of the kernel image" 1146 select RELOCATABLE 1147 depends on MMU && 64BIT && !XIP_KERNEL 1148 help 1149 Randomizes the virtual address at which the kernel image is 1150 loaded, as a security feature that deters exploit attempts 1151 relying on knowledge of the location of kernel internals. 1152 1153 It is the bootloader's job to provide entropy, by passing a 1154 random u64 value in /chosen/kaslr-seed at kernel entry. 1155 1156 When booting via the UEFI stub, it will invoke the firmware's 1157 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1158 to the kernel proper. In addition, it will randomise the physical 1159 location of the kernel Image as well. 1160 1161 If unsure, say N. 1162 1163endmenu # "Kernel features" 1164 1165menu "Boot options" 1166 1167config CMDLINE 1168 string "Built-in kernel command line" 1169 help 1170 For most platforms, the arguments for the kernel's command line 1171 are provided at run-time, during boot. However, there are cases 1172 where either no arguments are being provided or the provided 1173 arguments are insufficient or even invalid. 1174 1175 When that occurs, it is possible to define a built-in command 1176 line here and choose how the kernel should use it later on. 1177 1178choice 1179 prompt "Built-in command line usage" 1180 depends on CMDLINE != "" 1181 default CMDLINE_FALLBACK 1182 help 1183 Choose how the kernel will handle the provided built-in command 1184 line. 1185 1186config CMDLINE_FALLBACK 1187 bool "Use bootloader kernel arguments if available" 1188 help 1189 Use the built-in command line as fallback in case we get nothing 1190 during boot. This is the default behaviour. 1191 1192config CMDLINE_EXTEND 1193 bool "Extend bootloader kernel arguments" 1194 help 1195 The built-in command line will be appended to the command- 1196 line arguments provided during boot. This is useful in 1197 cases where the provided arguments are insufficient and 1198 you don't want to or cannot modify them. 1199 1200config CMDLINE_FORCE 1201 bool "Always use the default kernel command string" 1202 help 1203 Always use the built-in command line, even if we get one during 1204 boot. This is useful in case you need to override the provided 1205 command line on systems where you don't have or want control 1206 over it. 1207 1208endchoice 1209 1210config EFI_STUB 1211 bool 1212 1213config EFI 1214 bool "UEFI runtime support" 1215 depends on OF && !XIP_KERNEL 1216 depends on MMU 1217 default y 1218 select ARCH_SUPPORTS_ACPI if 64BIT 1219 select EFI_GENERIC_STUB 1220 select EFI_PARAMS_FROM_FDT 1221 select EFI_RUNTIME_WRAPPERS 1222 select EFI_STUB 1223 select LIBFDT 1224 select RISCV_ISA_C 1225 select UCS2_STRING 1226 help 1227 This option provides support for runtime services provided 1228 by UEFI firmware (such as non-volatile variables, realtime 1229 clock, and platform reset). A UEFI stub is also provided to 1230 allow the kernel to be booted as an EFI application. This 1231 is only useful on systems that have UEFI firmware. 1232 1233config DMI 1234 bool "Enable support for SMBIOS (DMI) tables" 1235 depends on EFI 1236 default y 1237 help 1238 This enables SMBIOS/DMI feature for systems. 1239 1240 This option is only useful on systems that have UEFI firmware. 1241 However, even with this option, the resultant kernel should 1242 continue to boot on existing non-UEFI platforms. 1243 1244config CC_HAVE_STACKPROTECTOR_TLS 1245 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1246 1247config STACKPROTECTOR_PER_TASK 1248 def_bool y 1249 depends on !RANDSTRUCT 1250 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1251 1252config PHYS_RAM_BASE_FIXED 1253 bool "Explicitly specified physical RAM address" 1254 depends on NONPORTABLE 1255 default n 1256 1257config PHYS_RAM_BASE 1258 hex "Platform Physical RAM address" 1259 depends on PHYS_RAM_BASE_FIXED 1260 default "0x80000000" 1261 help 1262 This is the physical address of RAM in the system. It has to be 1263 explicitly specified to run early relocations of read-write data 1264 from flash to RAM. 1265 1266config XIP_KERNEL 1267 bool "Kernel Execute-In-Place from ROM" 1268 depends on MMU && SPARSEMEM && NONPORTABLE 1269 # This prevents XIP from being enabled by all{yes,mod}config, which 1270 # fail to build since XIP doesn't support large kernels. 1271 depends on !COMPILE_TEST 1272 select PHYS_RAM_BASE_FIXED 1273 help 1274 Execute-In-Place allows the kernel to run from non-volatile storage 1275 directly addressable by the CPU, such as NOR flash. This saves RAM 1276 space since the text section of the kernel is not loaded from flash 1277 to RAM. Read-write sections, such as the data section and stack, 1278 are still copied to RAM. The XIP kernel is not compressed since 1279 it has to run directly from flash, so it will take more space to 1280 store it. The flash address used to link the kernel object files, 1281 and for storing it, is configuration dependent. Therefore, if you 1282 say Y here, you must know the proper physical address where to 1283 store the kernel image depending on your own flash memory usage. 1284 1285 Also note that the make target becomes "make xipImage" rather than 1286 "make zImage" or "make Image". The final kernel binary to put in 1287 ROM memory will be arch/riscv/boot/xipImage. 1288 1289 SPARSEMEM is required because the kernel text and rodata that are 1290 flash resident are not backed by memmap, then any attempt to get 1291 a struct page on those regions will trigger a fault. 1292 1293 If unsure, say N. 1294 1295config XIP_PHYS_ADDR 1296 hex "XIP Kernel Physical Location" 1297 depends on XIP_KERNEL 1298 default "0x21000000" 1299 help 1300 This is the physical address in your flash memory the kernel will 1301 be linked for and stored to. This address is dependent on your 1302 own flash usage. 1303 1304config RISCV_ISA_FALLBACK 1305 bool "Permit falling back to parsing riscv,isa for extension support by default" 1306 default y 1307 help 1308 Parsing the "riscv,isa" devicetree property has been deprecated and 1309 replaced by a list of explicitly defined strings. For compatibility 1310 with existing platforms, the kernel will fall back to parsing the 1311 "riscv,isa" property if the replacements are not found. 1312 1313 Selecting N here will result in a kernel that does not use the 1314 fallback, unless the commandline "riscv_isa_fallback" parameter is 1315 present. 1316 1317 Please see the dt-binding, located at 1318 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1319 on the replacement properties, "riscv,isa-base" and 1320 "riscv,isa-extensions". 1321 1322config BUILTIN_DTB 1323 bool "Built-in device tree" 1324 depends on OF && NONPORTABLE 1325 select GENERIC_BUILTIN_DTB 1326 help 1327 Build a device tree into the Linux image. 1328 This option should be selected if no bootloader is being used. 1329 If unsure, say N. 1330 1331 1332config BUILTIN_DTB_NAME 1333 string "Built-in device tree source" 1334 depends on BUILTIN_DTB 1335 help 1336 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1337 for the DTS file that will be used to produce the DTB linked into the 1338 kernel. 1339 1340endmenu # "Boot options" 1341 1342config PORTABLE 1343 bool 1344 default !NONPORTABLE 1345 select EFI 1346 select MMU 1347 select OF 1348 1349config ARCH_PROC_KCORE_TEXT 1350 def_bool y 1351 1352menu "Power management options" 1353 1354source "kernel/power/Kconfig" 1355 1356config ARCH_HIBERNATION_POSSIBLE 1357 def_bool y 1358 1359config ARCH_HIBERNATION_HEADER 1360 def_bool HIBERNATION 1361 1362config ARCH_SUSPEND_POSSIBLE 1363 def_bool y 1364 1365endmenu # "Power management options" 1366 1367menu "CPU Power Management" 1368 1369source "drivers/cpuidle/Kconfig" 1370 1371source "drivers/cpufreq/Kconfig" 1372 1373endmenu # "CPU Power Management" 1374 1375source "arch/riscv/kvm/Kconfig" 1376 1377source "drivers/acpi/Kconfig" 1378