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