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